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Papers by John Huggins

The Journal of Infectious Diseases, 2017

Human monkeypox is an endemic disease in rain-forested regions of central Democratic Republic of ... more Human monkeypox is an endemic disease in rain-forested regions of central Democratic Republic of Congo. We report fetal outcomes for 1 of 4 pregnant women who participated in an observational study at the General Hospital of Kole (Sankuru Province), where 222 symptomatic subjects were followed between 2007 and 2011. Of the 4 pregnant women, 1 gave birth to a healthy infant, 2 had miscarriages in the first trimester, and 1 had fetal death, with the macerated stillborn showing diffuse cutaneous maculopapillary skin lesions involving the head, trunk and extremities, including palms of hands and soles of feet.

Antiviral Chemistry and Chemotherapy, 2001

Two inhibitors of cellular inosine monophosphate dehydrogenase, mycophenolic acid (MPA) and ribav... more Two inhibitors of cellular inosine monophosphate dehydrogenase, mycophenolic acid (MPA) and ribavirin, were evaluated for inhibitory activity against orthopoxviruses. Unrelated antipoxvirus agents tested for comparison included 6-azauridine, cidofovir (HPMPC) and cyclic HPMPC. MPA inhibited camelpox, cowpox, monkeypox and vaccinia viruses by 50% in plaque reduction assays at 0.2–3 μM in African green monkey kidney (Vero 76) and mouse 3T3 cells. Ribavirin was considerably more active in 3T3 cells (50% inhibition at 2-l2 μM) than in Vero 76 cells (inhibitory at 30–250 μM) against these viruses. In cytotoxicity assays, MPA and ribavirin were more toxic to replicating cells than to stationary cell monolayers, with greater toxicity seen in 3T3 than in Vero 76 cells. The superior antiviral potency and increased toxicity of ribavirin in 3T3 cells was related to greater accumulation of mono-, di- and triphosphate forms of the drug compared with Vero 76 cells. For both MPA and ribavirin, vir...

Virology Journal, 2009

The Orthopoxvirus genus of Poxviridae family is comprised of several human pathogens, including c... more The Orthopoxvirus genus of Poxviridae family is comprised of several human pathogens, including cowpox (CPXV), Vaccinia (VACV), monkeypox (MPV) and Variola (VARV) viruses. Species of this virus genus cause human diseases with various severities and outcome ranging from mild conditions to death in fulminating cases. Currently, vaccination is the only protective measure against infection with these viruses and no licensed antiviral drug therapy is available. In this study, we investigated the potential of RNA interference pathway (RNAi) as a therapeutic approach for orthopox virus infections using MPV as a model. Based on genome-wide expression studies and bioinformatic analysis, we selected 12 viral genes and targeted them by small interference RNA (siRNA). Fortyeight siRNA constructs were developed and evaluated in vitro for their ability to inhibit viral replication. Two genes, each targeted with four different siRNA constructs in one pool, were limiting to viral replication. Seven siRNA constructs from these two pools, targeting either an essential gene for viral replication (A6R) or an important gene in viral entry (E8L), inhibited viral replication in cell culture by 65-95% with no apparent cytotoxicity. Further analysis with wild-type and recombinant MPV expressing green fluorescence protein demonstrated that one of these constructs, siA6-a, was the most potent and inhibited viral replication for up to 7 days at a concentration of 10 nM. These results emphasis the essential role of A6R gene in viral replication, and demonstrate the potential of RNAi as a therapeutic approach for developing oligonucleotidebased drug therapy for MPV and other orthopox viruses.

Proceedings of the National Academy of Sciences, 2004

Smallpox virus (variola) poses a significant threat as an agent of bioterrorism. To mitigate this... more Smallpox virus (variola) poses a significant threat as an agent of bioterrorism. To mitigate this risk, antiviral drugs and an improved vaccine are urgently needed. Satisfactory demonstration of protective efficacy against authentic variola will require development of an animal model in which variola produces a disease course with features consistent with human smallpox. Toward this end, cynomolgus macaques were exposed to several variola strains through aerosol and/or i.v. routes. Two strains, Harper and India 7124, produced uniform acute lethality when inoculated i.v. in high doses (10 9 plaque-forming units). Lower doses resulted in less fulminant, systemic disease and lower mortality. Animals that died had profound leukocytosis, thrombocytopenia, and elevated serum creatinine levels. After inoculation, variola was disseminated by means of a monocytic cell-associated viremia. Distribution of viral antigens by immunohistochemistry correlated with the presence of replicating viral ...

Proceedings of the National Academy of Sciences, 2004

Smallpox has played an unparalleled role in human history and remains a significant potential thr... more Smallpox has played an unparalleled role in human history and remains a significant potential threat to public health. Despite the historical significance of this disease, we know little about the underlying pathophysiology or the virulence mechanisms of the causative agent, variola virus. To improve our understanding of variola pathogenesis and variola-host interactions, we examined the molecular and cellular features of hemorrhagic smallpox in cynomolgus macaques. We used cDNA microarrays to analyze host gene expression patterns in sequential blood samples from each of 22 infected animals. Variola infection elicited striking and temporally coordinated patterns of gene expression in peripheral blood. Of particular interest were features that appear to represent an IFN response, cell proliferation, immunoglobulin gene expression, viral dose-dependent gene expression patterns, and viral modulation of the host immune response. The virtual absence of a tumor necrosis factor α/NF-κB-act...

PLoS ONE, 2011

Smallpox, caused by variola virus (VARV), is a devastating human disease that affected millions w... more Smallpox, caused by variola virus (VARV), is a devastating human disease that affected millions worldwide until the virus was eradicated in the 1970 s. Subsequent cessation of vaccination has resulted in an immunologically naive human population that would be at risk should VARV be used as an agent of bioterrorism. The development of antivirals and improved vaccines to counter this threat would be facilitated by the development of animal models using authentic VARV. Towards this end, cynomolgus macaques were identified as adequate hosts for VARV, developing ordinary or hemorrhagic smallpox in a dose-dependent fashion. To further refine this model, we performed a serial sampling study on macaques exposed to doses of VARV strain Harper calibrated to induce ordinary or hemorrhagic disease. Several key differences were noted between these models. In the ordinary smallpox model, lymphoid and myeloid hyperplasias were consistently found whereas lymphocytolysis and hematopoietic necrosis developed in hemorrhagic smallpox. Viral antigen accumulation, as assessed immunohistochemically, was mild and transient in the ordinary smallpox model. In contrast, in the hemorrhagic model antigen distribution was widespread and included tissues and cells not involved in the ordinary model. Hemorrhagic smallpox developed only in the presence of secondary bacterial infections-an observation also commonly noted in historical reports of human smallpox. Together, our results support the macaque model as an excellent surrogate for human smallpox in terms of disease onset, acute disease course, and gross and histopathological lesions.

Laboratory Investigation, 2003

Smallpox disease has been eradicated from the human population since 1979, but is again a concern... more Smallpox disease has been eradicated from the human population since 1979, but is again a concern because of its potential use as an agent of bioterrorism or biowarfare. World Health Organization-sanctioned repositories of infectious Variola virus are known to occur in both Russia and the United States, but many believe other undeclared and unregulated sources of the virus could exist. Thus, validation of improved methods for definitive identification of smallpox virus in diagnostic specimens is urgently needed. In this paper, we describe the discovery of suspected Variola infected human tissue, fixed and preserved for decades in largely unknown solutions, and the use of routine histology, electron microscopy, and ultimately DNA extraction and fluorogenic 5 0 nuclease (TaqMan s) assays for its identification and confirmation.

The Journal of Infectious Diseases, 2005

Emerging Infectious Diseases, 2014

Monkeypox virus is a zoonotic virus endemic to Central Africa. Although active disease surveillan... more Monkeypox virus is a zoonotic virus endemic to Central Africa. Although active disease surveillance has assessed monkeypox disease prevalence and geographic range, information about virus diversity is lacking. We therefore assessed genome diversity of viruses in 60 samples obtained from humans with primary and secondary cases of infection from 2005 through 2007. We detected 4 distinct lineages and a deletion that resulted in gene loss in 10 (16.7%) samples and that seemed to correlate with human-to-human transmission (p = 0.0544). The data suggest a high frequency of spillover events from the pool of viruses in nonhuman animals, active selection through genomic destabilization and gene loss, and increased disease transmissibility and severity. The potential for accelerated adaptation to humans should be monitored through improved surveillance.

Antimicrobial Agents and Chemotherapy, 2002

ABSTRACTCidofovir {[(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] [HPMPC]}-resistant forms... more ABSTRACTCidofovir {[(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] [HPMPC]}-resistant forms of camelpox, cowpox, monkeypox, and vaccinia viruses were developed by prolonged passage in Vero 76 cells in the presence of drug. Eight- to 27-fold-higher concentrations of cidofovir were required to inhibit the resistant viruses than were needed to inhibit the wild-type (WT) viruses. Resistant viruses were characterized by determining their cross-resistance to other antiviral compounds, examining their different replication abilities in two cell lines, studying the biochemical basis of their drug resistance, and assessing the degrees of their virulence in mice. These viruses were cross resistant to cyclic HPMPC and, with the exception of vaccinia virus, to (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)adenine. Three of the four resistant cowpox and monkeypox viruses exhibited reduced abilities to infect and replicate in 3T3 cells compared to their abilities in Vero 76 cells. Compared to ...

Antimicrobial Agents and Chemotherapy, 2009

ST-246, a potent orthopoxvirus egress inhibitor, is safe and effective at preventing disease and ... more ST-246, a potent orthopoxvirus egress inhibitor, is safe and effective at preventing disease and death in studies of small-animal models involving challenge by several different pathogenic poxviruses. In this report, the antiviral efficacy of ST-246 in treatment of nonhuman primates infected with variola virus or monkeypox virus was assessed. The data indicate that oral dosing once per day with ST-246 protects animals from poxvirus disease, as measured by reductions in viral load and numbers of lesions and enhancement of survival.

Antimicrobial Agents and Chemotherapy, 2009

ABSTRACTTherapeutics for the treatment of pathogenic orthopoxvirus infections are being sought. I... more ABSTRACTTherapeutics for the treatment of pathogenic orthopoxvirus infections are being sought. In the absence of patients with disease, animal models of orthopoxvirus disease are essential for evaluation of the efficacies of antiviral drugs and establishment of the appropriate dose and duration of human therapy. Infection of nonhuman primates (NHP) by the intravenous injection of monkeypox virus has been used to evaluate a promising therapeutic drug candidate, ST-246. ST-246 administered at 3 days postinfection (which corresponds to the secondary viremia stage of disease) at four different doses (from 100 mg/kg of body weight down to 3 mg/kg) once a day for 14 days was able to offer NHP 100% protection from a lethal infection with monkeypox virus and reduce the viral load and lesion formation. In NHP, the administration of ST-246 at a dose of 10 mg/kg/day for 14 days resulted in levels of blood exposure comparable to the levels attained in humans administered 400 mg in the fed stat...

Respirology (Carlton, Vic.), 2018

Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleura... more Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleural diseases, such as pleural infection (e.g. empyema and complicated parapneumonic effusion) and noninfectious fibrinous pleuritis. Unexpandable lung due to pleural disease may be because of an active pleural process, and is referred to as malignant or inflammatory lung entrapment. An unexpandable lung may also be encountered in the setting of remote pleural inflammation resulting in a mature fibrous membrane overlying the visceral pleura preventing full expansion of the lung. This condition is termed trapped lung and may be understood as a form of defective healing of the pleural space. Trapped lung typically presents as a chronic, stable pleural effusion without evidence of active pleural disease. An unexpandable lung most often manifests itself as an inability of fully expanding the lung with pleural space drainage. Patients will either develop chest pain preventing complete drainage o...

Respirology (Carlton, Vic.), 2018

Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleura... more Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleural diseases, such as pleural infection (e.g. empyema and complicated parapneumonic effusion) and noninfectious fibrinous pleuritis. Unexpandable lung due to pleural disease may be because of an active pleural process, and is referred to as malignant or inflammatory lung entrapment. An unexpandable lung may also be encountered in the setting of remote pleural inflammation resulting in a mature fibrous membrane overlying the visceral pleura preventing full expansion of the lung. This condition is termed trapped lung and may be understood as a form of defective healing of the pleural space. Trapped lung typically presents as a chronic, stable pleural effusion without evidence of active pleural disease. An unexpandable lung most often manifests itself as an inability of fully expanding the lung with pleural space drainage. Patients will either develop chest pain preventing complete drainage o...

Thorax, Jan 9, 2016

We compared the accuracy of pleural ultrasound versus chest CT versus chest radiograph (CXR) to d... more We compared the accuracy of pleural ultrasound versus chest CT versus chest radiograph (CXR) to determine radiographic complexity in predicting a complicated parapneumonic effusion (CPPE) defined by pleural fluid analysis. 66 patients with parapneumonic effusions were identified with complete data. Pleural ultrasound had a sensitivity of 69.2% (95% CI 48.2% to 85.7%) and specificity of 90.0% (95% CI 76.3% to 97.2%). Chest CT had a sensitivity of 76.9% (95% CI 56.3% to 91.0%) and specificity of 65.0% (95% CI 48.3% to 79.4%). CXR had a sensitivity of 61.5% (95% CI 40.6% to 79.8%) and specificity of 60.0% (95% CI 43.3% to 75.1%). Pleural ultrasound appears to be a superior modality to rule in a CPPE when compared with chest CT and CXR.

Seminars in Respiratory and Critical Care Medicine, 2010

A chylothorax and a cholesterol pleural effusion represent the two forms of lipid effusions encou... more A chylothorax and a cholesterol pleural effusion represent the two forms of lipid effusions encountered. Traditionally, a lipid pleural effusion is characterized by the presence of milky fluid. Although these two effusions often share a similar pleural fluid appearance due to the high lipid concentration, they have major differences in the pathogenesis, clinical presentation, diagnosis, predisposing conditions, and management of these effusions. A chylothorax is defined by the presence of chyle in the pleural space resulting from obstruction or disruption of the thoracic duct or one of its major tributaries. A triglyceride concentration > 110 mg/dL is virtually diagnostic, but the presence of chylomicrons confirms the diagnosis. However, a chylothorax defined by these criteria represents a heterogeneous group of clinical entities. The presence of chylomicrons or triglyceride levels > 110 mg/dL in a pleural effusion should be considered evidence of chyle leakage of indeterminate clinical significance. Many cases of a chylous effusion may be associated with other causes of pleural fluid formation. In the case of an acute or chronic chylothorax due to recent or remote thoracic duct injury, this assessment is essential, as surgical ligation of the thoracic duct is often entertained. In other cases, especially lymphoma or chylous ascites, treatment of the underlying condition is indicated regardless, and the assessment of the response to treatment is a reasonable initial approach. In contrast, a cholesterol effusion is typically the result of long-standing pleurisy with elevated cholesterol levels in the pleural space; however, this paradigm has been challenged. Lung entrapment with thickened parietal and visceral pleural membranes is the typical radiographic findings of a cholesterol effusion. Most cases of cholesterol pleural effusions are attributed to tuberculous or rheumatoid pleurisy. Decortication is the mainstay of treatment for a cholesterol effusion in symptomatic patients with restrictive lung function.

CHEST Journal, 2012

ABSTRACT SESSION TYPE: Bronchology Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at ... more ABSTRACT SESSION TYPE: Bronchology Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: Secondary spontaneous pneumothorax (SSP) occurs as a result of pre-existing lung disease [1]. While chronic obstructive pulmonary disease is more common, fibrocystic sarcoidosis may lead to SSP and pose difficult management challenges [2]. An air leak that persists at seven days despite thoracostomy tube evacuation is classified as prolonged, and more aggressive approaches must be considered including video assisted thoracoscopy (VATS) pleurodesis and/or stapling of the air leak source. Alternatively, patients receive prolonged inpatient thoracostomy drainage, which adds significant health care costs and predisposes patients to complications. For patients who are not candidates for invasive procedures, endobronchial valve placement is an emerging option. Currently, one endobronchial valve has received a humanitarian device exclusion (HDE) to treat the rare condition of prolonged air leaks following lobectomy, segmentectomy, or lung volume reduction surgery. Use for prolonged air leaks in patients with lung diseases other than emphysema has been the subject of case reports. We report 2 cases in which EBV were used to treat prolonged SSP.CASE PRESENTATION: Case 1: A 56-year-old female with stage 4 sarcoidosis, dyspnea, and a right pneumothorax had a chest tube placed followed by VATS talc pleurodesis. The air leak persisted and endobronchial valve placement was performed with immediate resolution of the air leak. Case 2: A 34-year-old male with stage 4 sarcoidosis presented with dyspnea and a large left basilar pneumothorax. Chest tube placement and blood patch pleurodesis failed to resolve the pneumothorax. Four endobronchial valves were placed in the left upper lobe and lingula with slowing but not resolution of the air leak. The patient then underwent VATS, which had to be converted to a left upper lobectomy.DISCUSSION: Endobronchial valves are a novel treatment option for prolonged air leaks due to pneumothorax; however, the recommendations for its use outside of post-surgical air leaks are unclear. These 2 cases demonstrate success and failure of this intervention in patients who are not post-surgical and do not have emphysema.CONCLUSIONS: Further studies are needed before this procedure becomes standard of care, and for now it should be considered in carefully selected patients under the category of compassionate use.1) Sahn SA, Heffner JE. Spontaneous pneumothorax. N Engl J Med 2000; 342: 868.2) Wait MA, Estrera A. Changing clinical spectrum of spontaneous pneumothorax. Am J Surg 1992; 164: 528.DISCLOSURE: The following authors have nothing to disclose: Travis Greer, Nicholas Pastis, Charlie Strange, John HugginsThe use of endobronchial valves is not yet FDA approved for treatment of persistent secondary spontaneous pneumothorax, It is approved by the FDA under the Humanitarian Device Exemption for use in controlling prolonged air leaks of the lung or significant air leaks that are likely to become prolonged air leaks following lobectomy, segmentectomy, or lung volume reduction surgery. Medical University of South Carolina, Charleston, SC.

CHEST Journal, 2012

ABSTRACT SESSION TYPE: Critical Care Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 a... more ABSTRACT SESSION TYPE: Critical Care Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: Refractory status asthmaticus represents a considerable challenge in the intensive care unit. Progressive respiratory failure due to asthma in which conventional forms of therapy have failed carries significant morbidity and mortality. We present a case of refractory status asthmaticus in which several non-standard treatments were successfully utilized, including extracorporeal membrane oxygenation (ECMO) and inhaled anesthetics.CASE PRESENTATION: 34 year old African American female transferred to our facility with an acute asthma exacerbation necessitating mechanical ventilation. Examination on admission was notable for diffuse bilateral expiratory wheezing and tachycardia. Arterial blood gas showed an acute respiratory acidosis. Respiratory viral PCR was positive for rhinovirus/enterovirus. Chest radiograph showed marked hyperinflation without focal opacity. In addition to mechanical ventilation, she was started on aggressive inhaled bronchodilator therapy and systemic corticosteroids. Despite standard therapy, she developed elevated peak and plateau pressures and intrinsic PEEP leading to impaired ventilation and hemodynamic compromise. Her condition deteriorated despite addition of ketamine, paralytics, and ventilator adjustments. Veno-venous ECMO was initiated. Intravenous treatments were attempted including aminophylline and terbutaline without significant effect or harm. Ultimately, she seemed to clinically improve after introduction of inhaled isoflurane with dramatic resolution of her intrinsic PEEP and improved ventilator parameters. ECMO was discontinued after 9 days. Her course was complicated by critical care polyneuropathy and failure to wean requiring tracheostomy. She was subsequently weaned from ventilatory support, decannulated, and discharged to a sub-acute rehabilitation facility.DISCUSSION: Standard therapy for severe status asthmaticus includes bronchodilators, systemic corticosteroids, and often mechanical ventilation. Despite standard therapy, some patients remain refractory necessitating adjunctive treatments with evidence limited to small clinical trials and case reports. Our case illustrates the utility of several non-standard interventions in a critically ill patient. While ECMO provided essential supportive care, there appeared to be an acute and dramatic improvement with addition of inhaled isofluorane.CONCLUSIONS: Management of severe refractory status asthmaticus in the critical care setting occasionally requires both standard and adjunctive therapies. ECMO was successfully used for patient support while other medications were given time to work. Inhaled isoflurane is the volatile anesthetic of choice, and has been shown to dramatically improve bronchial hyperactivity in small case studies.1) Outcomes Using Extracorporeal Life Support For Adult Respiratory Failure Due to Status Asthmaticus. ASAIO J. 2009; 55(1):47-52.2) Isoflurane Therapy for Status Asthmaticus in Children and Adults. CHEST 1990;97:698-701.DISCLOSURE: The following authors have nothing to disclose: Clayton Shamblin, Matthew Divietro, Charlie Strange, John HugginsNo Product/Research Disclosure InformationMedical University of South Carolina, Charleston, SC.

The Journal of Infectious Diseases, 2017

Human monkeypox is an endemic disease in rain-forested regions of central Democratic Republic of ... more Human monkeypox is an endemic disease in rain-forested regions of central Democratic Republic of Congo. We report fetal outcomes for 1 of 4 pregnant women who participated in an observational study at the General Hospital of Kole (Sankuru Province), where 222 symptomatic subjects were followed between 2007 and 2011. Of the 4 pregnant women, 1 gave birth to a healthy infant, 2 had miscarriages in the first trimester, and 1 had fetal death, with the macerated stillborn showing diffuse cutaneous maculopapillary skin lesions involving the head, trunk and extremities, including palms of hands and soles of feet.

Antiviral Chemistry and Chemotherapy, 2001

Two inhibitors of cellular inosine monophosphate dehydrogenase, mycophenolic acid (MPA) and ribav... more Two inhibitors of cellular inosine monophosphate dehydrogenase, mycophenolic acid (MPA) and ribavirin, were evaluated for inhibitory activity against orthopoxviruses. Unrelated antipoxvirus agents tested for comparison included 6-azauridine, cidofovir (HPMPC) and cyclic HPMPC. MPA inhibited camelpox, cowpox, monkeypox and vaccinia viruses by 50% in plaque reduction assays at 0.2–3 μM in African green monkey kidney (Vero 76) and mouse 3T3 cells. Ribavirin was considerably more active in 3T3 cells (50% inhibition at 2-l2 μM) than in Vero 76 cells (inhibitory at 30–250 μM) against these viruses. In cytotoxicity assays, MPA and ribavirin were more toxic to replicating cells than to stationary cell monolayers, with greater toxicity seen in 3T3 than in Vero 76 cells. The superior antiviral potency and increased toxicity of ribavirin in 3T3 cells was related to greater accumulation of mono-, di- and triphosphate forms of the drug compared with Vero 76 cells. For both MPA and ribavirin, vir...

Virology Journal, 2009

The Orthopoxvirus genus of Poxviridae family is comprised of several human pathogens, including c... more The Orthopoxvirus genus of Poxviridae family is comprised of several human pathogens, including cowpox (CPXV), Vaccinia (VACV), monkeypox (MPV) and Variola (VARV) viruses. Species of this virus genus cause human diseases with various severities and outcome ranging from mild conditions to death in fulminating cases. Currently, vaccination is the only protective measure against infection with these viruses and no licensed antiviral drug therapy is available. In this study, we investigated the potential of RNA interference pathway (RNAi) as a therapeutic approach for orthopox virus infections using MPV as a model. Based on genome-wide expression studies and bioinformatic analysis, we selected 12 viral genes and targeted them by small interference RNA (siRNA). Fortyeight siRNA constructs were developed and evaluated in vitro for their ability to inhibit viral replication. Two genes, each targeted with four different siRNA constructs in one pool, were limiting to viral replication. Seven siRNA constructs from these two pools, targeting either an essential gene for viral replication (A6R) or an important gene in viral entry (E8L), inhibited viral replication in cell culture by 65-95% with no apparent cytotoxicity. Further analysis with wild-type and recombinant MPV expressing green fluorescence protein demonstrated that one of these constructs, siA6-a, was the most potent and inhibited viral replication for up to 7 days at a concentration of 10 nM. These results emphasis the essential role of A6R gene in viral replication, and demonstrate the potential of RNAi as a therapeutic approach for developing oligonucleotidebased drug therapy for MPV and other orthopox viruses.

Proceedings of the National Academy of Sciences, 2004

Smallpox virus (variola) poses a significant threat as an agent of bioterrorism. To mitigate this... more Smallpox virus (variola) poses a significant threat as an agent of bioterrorism. To mitigate this risk, antiviral drugs and an improved vaccine are urgently needed. Satisfactory demonstration of protective efficacy against authentic variola will require development of an animal model in which variola produces a disease course with features consistent with human smallpox. Toward this end, cynomolgus macaques were exposed to several variola strains through aerosol and/or i.v. routes. Two strains, Harper and India 7124, produced uniform acute lethality when inoculated i.v. in high doses (10 9 plaque-forming units). Lower doses resulted in less fulminant, systemic disease and lower mortality. Animals that died had profound leukocytosis, thrombocytopenia, and elevated serum creatinine levels. After inoculation, variola was disseminated by means of a monocytic cell-associated viremia. Distribution of viral antigens by immunohistochemistry correlated with the presence of replicating viral ...

Proceedings of the National Academy of Sciences, 2004

Smallpox has played an unparalleled role in human history and remains a significant potential thr... more Smallpox has played an unparalleled role in human history and remains a significant potential threat to public health. Despite the historical significance of this disease, we know little about the underlying pathophysiology or the virulence mechanisms of the causative agent, variola virus. To improve our understanding of variola pathogenesis and variola-host interactions, we examined the molecular and cellular features of hemorrhagic smallpox in cynomolgus macaques. We used cDNA microarrays to analyze host gene expression patterns in sequential blood samples from each of 22 infected animals. Variola infection elicited striking and temporally coordinated patterns of gene expression in peripheral blood. Of particular interest were features that appear to represent an IFN response, cell proliferation, immunoglobulin gene expression, viral dose-dependent gene expression patterns, and viral modulation of the host immune response. The virtual absence of a tumor necrosis factor α/NF-κB-act...

PLoS ONE, 2011

Smallpox, caused by variola virus (VARV), is a devastating human disease that affected millions w... more Smallpox, caused by variola virus (VARV), is a devastating human disease that affected millions worldwide until the virus was eradicated in the 1970 s. Subsequent cessation of vaccination has resulted in an immunologically naive human population that would be at risk should VARV be used as an agent of bioterrorism. The development of antivirals and improved vaccines to counter this threat would be facilitated by the development of animal models using authentic VARV. Towards this end, cynomolgus macaques were identified as adequate hosts for VARV, developing ordinary or hemorrhagic smallpox in a dose-dependent fashion. To further refine this model, we performed a serial sampling study on macaques exposed to doses of VARV strain Harper calibrated to induce ordinary or hemorrhagic disease. Several key differences were noted between these models. In the ordinary smallpox model, lymphoid and myeloid hyperplasias were consistently found whereas lymphocytolysis and hematopoietic necrosis developed in hemorrhagic smallpox. Viral antigen accumulation, as assessed immunohistochemically, was mild and transient in the ordinary smallpox model. In contrast, in the hemorrhagic model antigen distribution was widespread and included tissues and cells not involved in the ordinary model. Hemorrhagic smallpox developed only in the presence of secondary bacterial infections-an observation also commonly noted in historical reports of human smallpox. Together, our results support the macaque model as an excellent surrogate for human smallpox in terms of disease onset, acute disease course, and gross and histopathological lesions.

Laboratory Investigation, 2003

Smallpox disease has been eradicated from the human population since 1979, but is again a concern... more Smallpox disease has been eradicated from the human population since 1979, but is again a concern because of its potential use as an agent of bioterrorism or biowarfare. World Health Organization-sanctioned repositories of infectious Variola virus are known to occur in both Russia and the United States, but many believe other undeclared and unregulated sources of the virus could exist. Thus, validation of improved methods for definitive identification of smallpox virus in diagnostic specimens is urgently needed. In this paper, we describe the discovery of suspected Variola infected human tissue, fixed and preserved for decades in largely unknown solutions, and the use of routine histology, electron microscopy, and ultimately DNA extraction and fluorogenic 5 0 nuclease (TaqMan s) assays for its identification and confirmation.

The Journal of Infectious Diseases, 2005

Emerging Infectious Diseases, 2014

Monkeypox virus is a zoonotic virus endemic to Central Africa. Although active disease surveillan... more Monkeypox virus is a zoonotic virus endemic to Central Africa. Although active disease surveillance has assessed monkeypox disease prevalence and geographic range, information about virus diversity is lacking. We therefore assessed genome diversity of viruses in 60 samples obtained from humans with primary and secondary cases of infection from 2005 through 2007. We detected 4 distinct lineages and a deletion that resulted in gene loss in 10 (16.7%) samples and that seemed to correlate with human-to-human transmission (p = 0.0544). The data suggest a high frequency of spillover events from the pool of viruses in nonhuman animals, active selection through genomic destabilization and gene loss, and increased disease transmissibility and severity. The potential for accelerated adaptation to humans should be monitored through improved surveillance.

Antimicrobial Agents and Chemotherapy, 2002

ABSTRACTCidofovir {[(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] [HPMPC]}-resistant forms... more ABSTRACTCidofovir {[(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] [HPMPC]}-resistant forms of camelpox, cowpox, monkeypox, and vaccinia viruses were developed by prolonged passage in Vero 76 cells in the presence of drug. Eight- to 27-fold-higher concentrations of cidofovir were required to inhibit the resistant viruses than were needed to inhibit the wild-type (WT) viruses. Resistant viruses were characterized by determining their cross-resistance to other antiviral compounds, examining their different replication abilities in two cell lines, studying the biochemical basis of their drug resistance, and assessing the degrees of their virulence in mice. These viruses were cross resistant to cyclic HPMPC and, with the exception of vaccinia virus, to (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)adenine. Three of the four resistant cowpox and monkeypox viruses exhibited reduced abilities to infect and replicate in 3T3 cells compared to their abilities in Vero 76 cells. Compared to ...

Antimicrobial Agents and Chemotherapy, 2009

ST-246, a potent orthopoxvirus egress inhibitor, is safe and effective at preventing disease and ... more ST-246, a potent orthopoxvirus egress inhibitor, is safe and effective at preventing disease and death in studies of small-animal models involving challenge by several different pathogenic poxviruses. In this report, the antiviral efficacy of ST-246 in treatment of nonhuman primates infected with variola virus or monkeypox virus was assessed. The data indicate that oral dosing once per day with ST-246 protects animals from poxvirus disease, as measured by reductions in viral load and numbers of lesions and enhancement of survival.

Antimicrobial Agents and Chemotherapy, 2009

ABSTRACTTherapeutics for the treatment of pathogenic orthopoxvirus infections are being sought. I... more ABSTRACTTherapeutics for the treatment of pathogenic orthopoxvirus infections are being sought. In the absence of patients with disease, animal models of orthopoxvirus disease are essential for evaluation of the efficacies of antiviral drugs and establishment of the appropriate dose and duration of human therapy. Infection of nonhuman primates (NHP) by the intravenous injection of monkeypox virus has been used to evaluate a promising therapeutic drug candidate, ST-246. ST-246 administered at 3 days postinfection (which corresponds to the secondary viremia stage of disease) at four different doses (from 100 mg/kg of body weight down to 3 mg/kg) once a day for 14 days was able to offer NHP 100% protection from a lethal infection with monkeypox virus and reduce the viral load and lesion formation. In NHP, the administration of ST-246 at a dose of 10 mg/kg/day for 14 days resulted in levels of blood exposure comparable to the levels attained in humans administered 400 mg in the fed stat...

Respirology (Carlton, Vic.), 2018

Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleura... more Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleural diseases, such as pleural infection (e.g. empyema and complicated parapneumonic effusion) and noninfectious fibrinous pleuritis. Unexpandable lung due to pleural disease may be because of an active pleural process, and is referred to as malignant or inflammatory lung entrapment. An unexpandable lung may also be encountered in the setting of remote pleural inflammation resulting in a mature fibrous membrane overlying the visceral pleura preventing full expansion of the lung. This condition is termed trapped lung and may be understood as a form of defective healing of the pleural space. Trapped lung typically presents as a chronic, stable pleural effusion without evidence of active pleural disease. An unexpandable lung most often manifests itself as an inability of fully expanding the lung with pleural space drainage. Patients will either develop chest pain preventing complete drainage o...

Respirology (Carlton, Vic.), 2018

Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleura... more Unexpandable lung is a common complication of malignant pleural effusions and inflammatory pleural diseases, such as pleural infection (e.g. empyema and complicated parapneumonic effusion) and noninfectious fibrinous pleuritis. Unexpandable lung due to pleural disease may be because of an active pleural process, and is referred to as malignant or inflammatory lung entrapment. An unexpandable lung may also be encountered in the setting of remote pleural inflammation resulting in a mature fibrous membrane overlying the visceral pleura preventing full expansion of the lung. This condition is termed trapped lung and may be understood as a form of defective healing of the pleural space. Trapped lung typically presents as a chronic, stable pleural effusion without evidence of active pleural disease. An unexpandable lung most often manifests itself as an inability of fully expanding the lung with pleural space drainage. Patients will either develop chest pain preventing complete drainage o...

Thorax, Jan 9, 2016

We compared the accuracy of pleural ultrasound versus chest CT versus chest radiograph (CXR) to d... more We compared the accuracy of pleural ultrasound versus chest CT versus chest radiograph (CXR) to determine radiographic complexity in predicting a complicated parapneumonic effusion (CPPE) defined by pleural fluid analysis. 66 patients with parapneumonic effusions were identified with complete data. Pleural ultrasound had a sensitivity of 69.2% (95% CI 48.2% to 85.7%) and specificity of 90.0% (95% CI 76.3% to 97.2%). Chest CT had a sensitivity of 76.9% (95% CI 56.3% to 91.0%) and specificity of 65.0% (95% CI 48.3% to 79.4%). CXR had a sensitivity of 61.5% (95% CI 40.6% to 79.8%) and specificity of 60.0% (95% CI 43.3% to 75.1%). Pleural ultrasound appears to be a superior modality to rule in a CPPE when compared with chest CT and CXR.

Seminars in Respiratory and Critical Care Medicine, 2010

A chylothorax and a cholesterol pleural effusion represent the two forms of lipid effusions encou... more A chylothorax and a cholesterol pleural effusion represent the two forms of lipid effusions encountered. Traditionally, a lipid pleural effusion is characterized by the presence of milky fluid. Although these two effusions often share a similar pleural fluid appearance due to the high lipid concentration, they have major differences in the pathogenesis, clinical presentation, diagnosis, predisposing conditions, and management of these effusions. A chylothorax is defined by the presence of chyle in the pleural space resulting from obstruction or disruption of the thoracic duct or one of its major tributaries. A triglyceride concentration > 110 mg/dL is virtually diagnostic, but the presence of chylomicrons confirms the diagnosis. However, a chylothorax defined by these criteria represents a heterogeneous group of clinical entities. The presence of chylomicrons or triglyceride levels > 110 mg/dL in a pleural effusion should be considered evidence of chyle leakage of indeterminate clinical significance. Many cases of a chylous effusion may be associated with other causes of pleural fluid formation. In the case of an acute or chronic chylothorax due to recent or remote thoracic duct injury, this assessment is essential, as surgical ligation of the thoracic duct is often entertained. In other cases, especially lymphoma or chylous ascites, treatment of the underlying condition is indicated regardless, and the assessment of the response to treatment is a reasonable initial approach. In contrast, a cholesterol effusion is typically the result of long-standing pleurisy with elevated cholesterol levels in the pleural space; however, this paradigm has been challenged. Lung entrapment with thickened parietal and visceral pleural membranes is the typical radiographic findings of a cholesterol effusion. Most cases of cholesterol pleural effusions are attributed to tuberculous or rheumatoid pleurisy. Decortication is the mainstay of treatment for a cholesterol effusion in symptomatic patients with restrictive lung function.

CHEST Journal, 2012

ABSTRACT SESSION TYPE: Bronchology Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at ... more ABSTRACT SESSION TYPE: Bronchology Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: Secondary spontaneous pneumothorax (SSP) occurs as a result of pre-existing lung disease [1]. While chronic obstructive pulmonary disease is more common, fibrocystic sarcoidosis may lead to SSP and pose difficult management challenges [2]. An air leak that persists at seven days despite thoracostomy tube evacuation is classified as prolonged, and more aggressive approaches must be considered including video assisted thoracoscopy (VATS) pleurodesis and/or stapling of the air leak source. Alternatively, patients receive prolonged inpatient thoracostomy drainage, which adds significant health care costs and predisposes patients to complications. For patients who are not candidates for invasive procedures, endobronchial valve placement is an emerging option. Currently, one endobronchial valve has received a humanitarian device exclusion (HDE) to treat the rare condition of prolonged air leaks following lobectomy, segmentectomy, or lung volume reduction surgery. Use for prolonged air leaks in patients with lung diseases other than emphysema has been the subject of case reports. We report 2 cases in which EBV were used to treat prolonged SSP.CASE PRESENTATION: Case 1: A 56-year-old female with stage 4 sarcoidosis, dyspnea, and a right pneumothorax had a chest tube placed followed by VATS talc pleurodesis. The air leak persisted and endobronchial valve placement was performed with immediate resolution of the air leak. Case 2: A 34-year-old male with stage 4 sarcoidosis presented with dyspnea and a large left basilar pneumothorax. Chest tube placement and blood patch pleurodesis failed to resolve the pneumothorax. Four endobronchial valves were placed in the left upper lobe and lingula with slowing but not resolution of the air leak. The patient then underwent VATS, which had to be converted to a left upper lobectomy.DISCUSSION: Endobronchial valves are a novel treatment option for prolonged air leaks due to pneumothorax; however, the recommendations for its use outside of post-surgical air leaks are unclear. These 2 cases demonstrate success and failure of this intervention in patients who are not post-surgical and do not have emphysema.CONCLUSIONS: Further studies are needed before this procedure becomes standard of care, and for now it should be considered in carefully selected patients under the category of compassionate use.1) Sahn SA, Heffner JE. Spontaneous pneumothorax. N Engl J Med 2000; 342: 868.2) Wait MA, Estrera A. Changing clinical spectrum of spontaneous pneumothorax. Am J Surg 1992; 164: 528.DISCLOSURE: The following authors have nothing to disclose: Travis Greer, Nicholas Pastis, Charlie Strange, John HugginsThe use of endobronchial valves is not yet FDA approved for treatment of persistent secondary spontaneous pneumothorax, It is approved by the FDA under the Humanitarian Device Exemption for use in controlling prolonged air leaks of the lung or significant air leaks that are likely to become prolonged air leaks following lobectomy, segmentectomy, or lung volume reduction surgery. Medical University of South Carolina, Charleston, SC.

CHEST Journal, 2012

ABSTRACT SESSION TYPE: Critical Care Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 a... more ABSTRACT SESSION TYPE: Critical Care Case Report PostersPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: Refractory status asthmaticus represents a considerable challenge in the intensive care unit. Progressive respiratory failure due to asthma in which conventional forms of therapy have failed carries significant morbidity and mortality. We present a case of refractory status asthmaticus in which several non-standard treatments were successfully utilized, including extracorporeal membrane oxygenation (ECMO) and inhaled anesthetics.CASE PRESENTATION: 34 year old African American female transferred to our facility with an acute asthma exacerbation necessitating mechanical ventilation. Examination on admission was notable for diffuse bilateral expiratory wheezing and tachycardia. Arterial blood gas showed an acute respiratory acidosis. Respiratory viral PCR was positive for rhinovirus/enterovirus. Chest radiograph showed marked hyperinflation without focal opacity. In addition to mechanical ventilation, she was started on aggressive inhaled bronchodilator therapy and systemic corticosteroids. Despite standard therapy, she developed elevated peak and plateau pressures and intrinsic PEEP leading to impaired ventilation and hemodynamic compromise. Her condition deteriorated despite addition of ketamine, paralytics, and ventilator adjustments. Veno-venous ECMO was initiated. Intravenous treatments were attempted including aminophylline and terbutaline without significant effect or harm. Ultimately, she seemed to clinically improve after introduction of inhaled isoflurane with dramatic resolution of her intrinsic PEEP and improved ventilator parameters. ECMO was discontinued after 9 days. Her course was complicated by critical care polyneuropathy and failure to wean requiring tracheostomy. She was subsequently weaned from ventilatory support, decannulated, and discharged to a sub-acute rehabilitation facility.DISCUSSION: Standard therapy for severe status asthmaticus includes bronchodilators, systemic corticosteroids, and often mechanical ventilation. Despite standard therapy, some patients remain refractory necessitating adjunctive treatments with evidence limited to small clinical trials and case reports. Our case illustrates the utility of several non-standard interventions in a critically ill patient. While ECMO provided essential supportive care, there appeared to be an acute and dramatic improvement with addition of inhaled isofluorane.CONCLUSIONS: Management of severe refractory status asthmaticus in the critical care setting occasionally requires both standard and adjunctive therapies. ECMO was successfully used for patient support while other medications were given time to work. Inhaled isoflurane is the volatile anesthetic of choice, and has been shown to dramatically improve bronchial hyperactivity in small case studies.1) Outcomes Using Extracorporeal Life Support For Adult Respiratory Failure Due to Status Asthmaticus. ASAIO J. 2009; 55(1):47-52.2) Isoflurane Therapy for Status Asthmaticus in Children and Adults. CHEST 1990;97:698-701.DISCLOSURE: The following authors have nothing to disclose: Clayton Shamblin, Matthew Divietro, Charlie Strange, John HugginsNo Product/Research Disclosure InformationMedical University of South Carolina, Charleston, SC.