sameer ahmed - Academia.edu (original) (raw)

Papers by sameer ahmed

AIMS Public Health

Background: Many civil liberties organizations have raised concerns that substandard medical care... more Background: Many civil liberties organizations have raised concerns that substandard medical care in United States Immigration and Customs Enforcement (ICE) detention facilities have led to preventable deaths. The 2018 Department of Homeland Security Appropriations Bill required ICE to make public all reports regarding in-custody deaths within 90 days beginning in Fiscal Year (FY) 2018. Accordingly, ICE has released death reports following each in-custody death since April of 2018. This study describes characteristics of deaths among individuals in ICE detention following the FY2018 mandate. Methods: Data was extracted from death reports published by ICE following the FY2018 mandate. Causes of death were categorized as suicide or medical, and medical deaths as COVID-19-related or not. Characteristics were compared between medical and suicide deaths, and among medical deaths between COVID-19-related and non-COVID-19-related deaths. Additionally, death rates per person-year and per 100,000 admissions were calculated for FY2018, 2019, and 2020 using methods from prior work evaluating deaths among detained immigrants in the United States. Results: Since April 2018, 35 individuals have died in ICE detention. The death rate per 100,000 admissions in ICE detention was 2.303 in FY2018, 1.499 in FY2019, and 10.833 in FY2020. Suicide by hanging was identified as the cause of death in 9 (25.7%), and medical causes in the remaining 26 (74.3%). Among 26 deaths attributable to medical causes, 8 (30.8%) were attributed to COVID-19, representing 72.7% of 11 deaths occurring since April 2020. Conclusions: The death rate among individuals in ICE detention is increasing amidst the COVID-19 pandemic. Potentially preventable causes of death including COVID-19 and suicide contribute to at least half of recent deaths. Findings suggest that individuals detained by ICE may benefit from improved psychiatric care and prevention

Scientific Reports

Top-Down Proteomics (TDP) is an emerging proteomics protocol that involves identification, charac... more Top-Down Proteomics (TDP) is an emerging proteomics protocol that involves identification, characterization, and quantitation of intact proteins using high-resolution mass spectrometry. TDP has an edge over other proteomics protocols in that it allows for: (i) accurate measurement of intact protein mass, (ii) high sequence coverage, and (iii) enhanced identification of post-translational modifications (PTMs). However, the complexity of TDP spectra poses a significant impediment to protein search and PTM characterization. Furthermore, limited software support is currently available in the form of search algorithms and pipelines. To address this need, we propose 'SPECTRUM', an open-architecture and open-source toolbox for TDP data analysis. Its salient features include: (i) MS2-based intact protein mass tuning, (ii) de novo peptide sequence tag analysis, (iii) propensity-driven PTM characterization, (iv) blind PTM search, (v) spectral comparison, (vi) identification of truncated proteins, (vii) multifactorial coefficient-weighted scoring, and (viii) intuitive graphical user interfaces to access the aforementioned functionalities and visualization of results. We have validated SPECTRUM using published datasets and benchmarked it against salient TDP tools. SPECTRUM provides significantly enhanced protein identification rates (91% to 177%) over its contemporaries. SPECTRUM has been implemented in MATLAB, and is freely available along with its source code and documentation at https://github.com/ BIRL/SPECTRUM/. Mass spectrometry-based proteomics is a well-established technique for protein identification, characterization, and quantitation 1-3. The conventional Bottom-Up Proteomics (BUP) 4 protocol involves mass spectrometry (MS) analysis of peptides obtained from enzymatic digestion of whole proteins 4,5. Several software tools such as SEQUEST 6 , Mascot 7 and ExPASy tools 8 (FindPept 9 and EasyProt 10) have been reported for BUP data analysis. However, BUP spectra and its analysis have limited power in: (i) identification of post-translational modifications (PTMs) 2 , (ii) sequence coverage 11,12 , and (iii) characterization of very small proteins 13. Recent advancements in proteomics protocols and instrumentation have enabled precise mass measurements of large proteins by employing soft ionization techniques 14 coupled with high-resolution mass analyzers 15. This has led to the emergence of Top-Down Proteomics 16 (TDP) protocol which is becoming increasingly popular for analyzing intact proteins 17,18. TDP offers an enhanced sequence coverage 19 as compared to BUP 4 along with an improved identification of proteoforms (proteins and its variants) 20,21. However, the complexity of high-resolution TDP spectral data poses a significant challenge for analysis tools. Current tools for TDP include ProSight PTM 12 , ProSight PTM 2.0 22 , MS-Align+ 23 , pTop 24 , TopPIC 25 , and MSPathFinder 26 amongst others.

Journal of the American College of Cardiology

The Laryngoscope, Oct 9, 2016

To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of ... more To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of patients undergoing repair of lateral skull base defects and spontaneous cerebrospinal fluid leaks with the middle cranial fossa approach. Case series. 3D-printed temporal bone models-based on patient-specific, high-resolution computed tomographic imaging-were constructed using inexpensive polymer materials. Preoperatively, the models demonstrated the extent of temporal lobe retraction necessary to visualize the proposed defects in the lateral skull base. Also preoperatively, Silastic sheeting was arranged across the modeled tegmen, marked, and cut to cover all of the proposed defect sites. The Silastic sheeting was then sterilized and subsequently served as a precise intraoperative template for a synthetic dural replacement graft. Of note, these grafts were customized without needing to retract the temporal lobe. Five patients underwent the middle cranial fossa approach assisted by 3D-p...

Http Www Theses Fr, Jan 24, 2013

Indian Journal of Anaesthesia, 2016

Sexual dimorphisms in adrenal function and distinct behavioral patterns of aggression and "emotio... more Sexual dimorphisms in adrenal function and distinct behavioral patterns of aggression and "emotionality" in SJL and C57/BL6 mouse strains led to an intriguing question: are there strain-and/or gender-specific differences in the adrenal gland at the level of ion channels? In this study, we focused on the adrenal medulla, which is a critical component of the neuroendocrine system and responsible for modulating reactions to stress and regulation of various body processes including digestion, the immune system, mood, and energy usage. Secretion of epinephrine (EPI) from chromaffin cells of the adrenal medulla is tightly controlled by the electrophysiologial response generated from neural inputs. Several studies suggest that the intrinsic excitability of these cells is modulated by the number and kenetic properties of large-conductance calcium(2+)activated potassium ion channels (BK channels). Therefore, we focused on BK channels to study strain-and gender-specific differences in the adrenal gland at the level of ion channels. Stress-and sex-steroids have been shown to regulate alternative splicing of the pore-forming subunit of BK channels (Slo-α) in several experimental contexts, and associated β-subunits confer on BK channels distinct sensitivities to acute effects of stress-and sex-steroids. Using a real-time PCR technique, we examined mRNA levels for total Slo, STREX (a stress-regulated splice-variant of Slo), β2, and β4 in two mouse strains, SJL and C57/BL6. The experimental groups were: SJL males, SJL females, and C57/BL6 males. SJL males expressed significantly higher levels of mRNA for total Slo, β2, and β4 than SJL females and C57/BL6 males. STREX levels were not significantly different between the groups, probably due to a small sample size, but on average, SJL males had higher levels of expression than the other two groups. These results suggest 2 that SJL females and C57/BL6 males are relatively similar in their BK channel expression in the adrenals, while SJL males show distinct expression patterns. From this study, we now have grounds for hypothesizing functional relationships between behavior and adrenal function.

Otology & Neurotology, 2015

To describe the rationale, intraoperative details, and histopathologic findings discovered when t... more To describe the rationale, intraoperative details, and histopathologic findings discovered when treating an unusual case of apogeotropic horizontal canal positional vertigo with a transmastoid labyrinthectomy. A single case report. Therapeutic. Resolution of apogeotropic nystagmus and improvement of positional vertigo. The apogeotropic variant of horizontal canal positional vertigo can be a difficult entity to treat. This report describes a patient who developed profound sensorineural hearing loss and vertigo after an acute left labyrinthitis. Ten months later, she developed vertigo with apogeotropic positional nystagmus involving the left horizontal semicircular canal. Particle repositioning maneuvers and vestibular physical therapy were unsuccessful. In addition, she developed intermittent positional vertigo affecting the ipsilateral vertical semicircular canals. Given the persistence of her vertigo, multiple canal involvement, and patient preference for definitive treatment, a transmastoid labyrinthectomy was performed. Intraoperatively, the ampulla of the horizontal canal as well as that of the other canals was grossly abnormal as later confirmed on histology. After surgery, her apogeotropic nystagmus and vertigo resolved, and her balance ability gradually improved to a highly functional level. This case illustrates a unique form of positional vertigo that developed and persisted after acute labyrinthitis. Conservative measures were unsuccessful and a transmastoid labyrinthectomy documented dense inflammatory tissue involving all three ampullae. We postulate that the post-labyrinthitic inflammatory changes resulted in mass loading of the membranous ampullae, causing abnormal nystagmus patterns and positional vertigo, which resolved after the labyrinthectomy.

Techniques in Vascular and Interventional Radiology, 2015

The role of the interventional radiologist continues to expand in the treatment of biliary diseas... more The role of the interventional radiologist continues to expand in the treatment of biliary disease. Percutaneous transhepatic cholangioscopy (PTCS) provides direct visualization of the biliary system for diagnostic and therapeutic interventions, especially in cases where anatomical considerations prohibit a peroral approach. Visual inspection and endoscopically guided biopsy allow differentiation between benign and malignant lesions, as well as accurate assessment of the tumor extent for surgical planning. Studies have demonstrated greater than 95% accuracy with PTCS in diagnosing biliary malignancies. Cholangioscopy is also used to treat obstructive stones in the biliary system, which may require laser lithotripsy. PTCS-guided removal of biliary stones is highly successful, with complete stone removal from the bile ducts occurring in approximately 90% of cases. Overall, PTCS is a safe and effective procedure, with severe complications occurring in less than 8% of patients. The purpose of this review is to familiarize its reader with common indications for PTCS, techniques for procedural success, expected outcomes, and management of potential complications.

Oral submucous fibrosis is a disease of individuals of Indian-south east asian subcontinent, rela... more Oral submucous fibrosis is a disease of individuals of Indian-south east asian subcontinent, related to the use of areca nuts, also found in pan masala and guthka. It is possible that it is due to the copper content which increases col-lagen cross-linking. pale, blanched mucosa and palpable fibrotic bands may progress to severely restricted oral opening. It can also affect the soft palate and tongue and produces epithelial atrophy. Oral submucous fibrosis is a premalig-nant condition; carcinoma develops possibly in upto 8% cases. Diagnosis is based on history of betel chewing; typical clinical features; biopsy and haematology. Often anaemia is present. Treatment includes discontinuation of habits, oral physiotherapy, nutritional supplements, intralesional steroids and placental extracts and surgical interventions. This paper deals with a case of malignancy developing from oral submucous fibrosis in a 47 year old patient. Sushruta -a renowned Indian physician, in his book " mout...

PURPOSE To determine the prevalence of unsuspected thyroid nodules on MDCT of the chest, in a pop... more PURPOSE To determine the prevalence of unsuspected thyroid nodules on MDCT of the chest, in a population of adult outpatients imaged for indications other than thyroid disease. METHOD AND MATERIALS 3077 consecutive adult outpatient's IV contrast enhanced 16- and 64-MDCT scans of the chest were reviewed retrospectively, to identify unsuspected thyroid nodules. Exclusion criteria included history of thyroid cancer, known thyroid nodules or thyroid disease and risk factors for thyroid cancer, as evidenced by their medical records. One of 9 radiologists recorded number of nodules, location and bidirectional measurement of largest nodule, as well as amount of thyroid visualized on the chest CT. Presence of nodule was correlated with age, gender, race and percentage of thyroid imaged. RESULTS Included were 2510 subjects, 1288 men (51.3%) and 1222 (48.7%) women. Mean age was 59.3 years (range 18 - 94 years). Women more frequently had 1 nodule (206/1222 or 16.86% of women vs. 181/1288 o...

PURPOSE/AIM Renal cell carcinoma may recur years following nephrectomy. While the recurrence ofte... more PURPOSE/AIM Renal cell carcinoma may recur years following nephrectomy. While the recurrence often arises in the surgical bed, lung and liver as with other malignancies, it is not uncommon for disease to arise in more unusual locations. These include pancreas, stomach, thyroid and within muscles or subcutaneous tissues. Protocol optimization is essential, as these lesions are often small and inconspicuous when initially discovered. CONTENT ORGANIZATION Introduction Data acquisition: conspicuity is optimized with arterial phase imaging; are 4 acquisitions necessary in the post-nephrectomy patient? Interpretation: role of MPRs, volume rendering and maximum intensity projection to facilitate lesion identification CT findings: thyroid lung and mediastinum stomach liver pancreas adrenal nephrectomy bed contralateral kidney muscle subcutaneous bone Conclusion SUMMARY After reviewing this exhibit, the radiologist will be able to recognize the range of appearances of recurrent renal cell ca...

JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2014

The aim of this study was to compare frictional resistance which was produced between conventiona... more The aim of this study was to compare frictional resistance which was produced between conventional brackets (0.022 slot Otho-Organiser) and self ligating brackets (active Forestadent and passive Damon III) by using various arch wire combinations (0.016 Niti, 0.018 Niti, 0.017 x 0.025 SS and 0.019 x 0.025 SS). An experimental model which consisted of 5 aligned stainless steel 0.022-in brackets was used to assess frictional forces which were produced by SLBs (self ligating brackets) and CELs (conventional elastomeric ligatures) with use of 0.016 nickel titanium, 0.018 nickel titanium, 0.017 X 0.025"stainless steel and 0.019 X 0.025"stainless steel wires. One way ANOVA test was used to study the effect of the bracket type, wire alloy and section on frictional resistance test . Conventional brackets produced highest levels of friction for all bracket/archwire combinations. Both Damon III and Forestadent brackets were found to produce significantly lower levels of friction when they were compared with elastomerically tied conventional brackets. SLBs are valid alternatives for low friction during sliding mechanics.

World Journal of Radiology, 2013

The purpose of this pictorial essay is to review the common and uncommon sites of renal cell carc... more The purpose of this pictorial essay is to review the common and uncommon sites of renal cell carcinoma recurrence throughout the body by examining their appearances on computerized tomography (CT). CT imaging protocols will be discussed. The sites of recurrence have been categorized into 4 groups: chest and mediastinum, abdomen and pelvis, musculoskeletal, and neurological. For each site of recurrence, a representative CT image correlate with discussion is provided. The unique CT appearance of renal cell carcinoma recurrence and how it can be used in lesion detection will be discussed. Renal cell carcinoma recurrences are hypervascular like the primary tumor, which can aid in not only lesion detection but also in some cases, differentiation from other primary tumors. Through CT case review of various sites of recurrence, lesions are shown to be easily seen on arterial phase while sometimes being nearly inconspicuous on venous or delayed phases. Coronal and sagittal reconstructions can also improve diagnostic sensitivity. CT is the most commonly used imaging tool for surveillance of renal cell carcinoma recurrence after nephrectomy. Knowledge of sites of recurrence as well as the utility of arterial phase imaging and multiplanar reconstructions will aid in optimizing detection of disease recurrence.

International Journal of Pediatric Otorhinolaryngology, 2012

(a) To evaluate the efficacy of doxycycline as a percutaneous sclerotherapy agent in pediatric he... more (a) To evaluate the efficacy of doxycycline as a percutaneous sclerotherapy agent in pediatric head and neck macrocystic lymphatic malformations (LM) and (b) to review the literature with regard to recent developments in the treatment of lymphatic malformations using sclerotherapy. We reviewed the medical records and imaging studies of all patients who underwent percutaneous sclerotherapy of macrocystic LM of the head and neck at our institution between June 2005 and May 2010. All studies were reviewed and procedures performed by a single interventional neuroradiologist using computed tomography (CT) guidance. LM were individually cannulated, the contents aspirated, and then injected with doxycycline at concentrations of 10-20 mg/ml. Response to sclerotherapy was determined clinically. Seven patients underwent a total of eight sclerotherapy treatments during the study period. Of the six patients with appropriate follow-up, 67% have experienced complete or near-complete clinical resolution of their LM (1243 days mean follow-up), while 33% have developed recurrent swelling after an initial response following a single doxycycline injection (53 days mean follow-up). Our institutional results, in combination with recently published findings, support the moderate efficacy and excellent safety profile of percutaneous doxycycline sclerotherapy for macrocystic lymphatic malformations.

F1000 - Post-publication peer review of the biomedical literature, 2000

F1000 - Post-publication peer review of the biomedical literature, 2000

Indian Journal of Dentistry, 2011

Pemphigus vulgaris is a common oral mucosal disease characterized by the occurrence of chronic mu... more Pemphigus vulgaris is a common oral mucosal disease characterized by the occurrence of chronic multiple ulcerative lesions. Although exact etiology is not known, the underlying mechanism responsible for causing intra-epithelial lesion of pemphigus vulgaris is binding of IgG autoantibodies to desmoglein 3, a transmembrane glycoprotein adhesion molecule. The characteristic oral lesions of pemphigus vulgaris are thin-walled fl accid bullae arising on otherwise normal skin or mucosa. The bullae rupture and extend peripherally, giving a large area of denuded skin or mucosa. Here, we report a case of a 56-year-old female patient suffering from exacerbations and remissions of pemphigus vulgaris since last 2 years, with a detailed review of literature. The present case report emphasizes a need of detailed case history, thorough oral and systemic examination, investigative measures, and a proper treatment regimen.

JAMA Otolaryngology–Head & Neck Surgery, 2014

IMPORTANCE Although infarction after fine-needle aspiration (FNA) is a rare occurrence, it is a k... more IMPORTANCE Although infarction after fine-needle aspiration (FNA) is a rare occurrence, it is a known phenomenon that may lead to difficulties in interpretation for pathologists and in decision-making for head and neck surgeons. OBJECTIVE To characterize our experience with infarction in papillary thyroid carcinomas (PTCs) after FNA and review existing cases of infarcted PTCs in the literature to better understand this phenomenon. DESIGN, SETTING, AND PARTICIPANTS This was a retrospective case series and review of literature at a tertiary medical center (University of California, Los Angeles [UCLA], Medical Center). All patients who had a surgical pathologic diagnosis of infarcted PTC and who underwent FNA prior to surgery at UCLA from June 2006 to June 2012 were identified. There were 620 cases of PTC and 12 cases of infarcted PTC. MAIN OUTCOMES AND MEASURE Demographic data, FNA cytologic findings, and surgical pathologic data were gathered for each patient. A comprehensive literature search for infarcted PTC was performed. RESULTS Twelve cases of infarcted PTC were found in a total of 620 cases of PTC (1.9%). The mean (SD) time interval between the last FNA and surgery was 52 (35) days (range, 13-133 days). All patients received a diagnosis of infarcted PTC after thyroidectomy was performed. Focal infarction was found in 4 patients (33%), and near-total infarction was found in 8 patients (67%). Five patients (47%) had the follicular variant of PTC, making it the most common subtype in our series. A thorough literature search yielded 11 articles reporting a total of 26 cases of infarcted PTC after FNA. To our knowledge, our case series on infarcted PTC is the largest reported series in the literature. CONCLUSIONS AND RELEVANCE Although infarction of PTC after FNA occurs infrequently, it may lead to difficulties in histologic diagnosis. Awareness of this phenomenon and its histologic associations, along with careful reevaluation of the FNA and surgical specimens, is important for appropriate diagnosis and subsequent treatment. At this point, infarction in PTC should not alarm a head and neck surgeon to change management, but future prospective studies with a large population of patients with infarcted PTCs are needed to establish the impact of infarction on differences in treatment outcomes for therapies that may be used in PTCs.

AIMS Public Health

Background: Many civil liberties organizations have raised concerns that substandard medical care... more Background: Many civil liberties organizations have raised concerns that substandard medical care in United States Immigration and Customs Enforcement (ICE) detention facilities have led to preventable deaths. The 2018 Department of Homeland Security Appropriations Bill required ICE to make public all reports regarding in-custody deaths within 90 days beginning in Fiscal Year (FY) 2018. Accordingly, ICE has released death reports following each in-custody death since April of 2018. This study describes characteristics of deaths among individuals in ICE detention following the FY2018 mandate. Methods: Data was extracted from death reports published by ICE following the FY2018 mandate. Causes of death were categorized as suicide or medical, and medical deaths as COVID-19-related or not. Characteristics were compared between medical and suicide deaths, and among medical deaths between COVID-19-related and non-COVID-19-related deaths. Additionally, death rates per person-year and per 100,000 admissions were calculated for FY2018, 2019, and 2020 using methods from prior work evaluating deaths among detained immigrants in the United States. Results: Since April 2018, 35 individuals have died in ICE detention. The death rate per 100,000 admissions in ICE detention was 2.303 in FY2018, 1.499 in FY2019, and 10.833 in FY2020. Suicide by hanging was identified as the cause of death in 9 (25.7%), and medical causes in the remaining 26 (74.3%). Among 26 deaths attributable to medical causes, 8 (30.8%) were attributed to COVID-19, representing 72.7% of 11 deaths occurring since April 2020. Conclusions: The death rate among individuals in ICE detention is increasing amidst the COVID-19 pandemic. Potentially preventable causes of death including COVID-19 and suicide contribute to at least half of recent deaths. Findings suggest that individuals detained by ICE may benefit from improved psychiatric care and prevention

Scientific Reports

Top-Down Proteomics (TDP) is an emerging proteomics protocol that involves identification, charac... more Top-Down Proteomics (TDP) is an emerging proteomics protocol that involves identification, characterization, and quantitation of intact proteins using high-resolution mass spectrometry. TDP has an edge over other proteomics protocols in that it allows for: (i) accurate measurement of intact protein mass, (ii) high sequence coverage, and (iii) enhanced identification of post-translational modifications (PTMs). However, the complexity of TDP spectra poses a significant impediment to protein search and PTM characterization. Furthermore, limited software support is currently available in the form of search algorithms and pipelines. To address this need, we propose 'SPECTRUM', an open-architecture and open-source toolbox for TDP data analysis. Its salient features include: (i) MS2-based intact protein mass tuning, (ii) de novo peptide sequence tag analysis, (iii) propensity-driven PTM characterization, (iv) blind PTM search, (v) spectral comparison, (vi) identification of truncated proteins, (vii) multifactorial coefficient-weighted scoring, and (viii) intuitive graphical user interfaces to access the aforementioned functionalities and visualization of results. We have validated SPECTRUM using published datasets and benchmarked it against salient TDP tools. SPECTRUM provides significantly enhanced protein identification rates (91% to 177%) over its contemporaries. SPECTRUM has been implemented in MATLAB, and is freely available along with its source code and documentation at https://github.com/ BIRL/SPECTRUM/. Mass spectrometry-based proteomics is a well-established technique for protein identification, characterization, and quantitation 1-3. The conventional Bottom-Up Proteomics (BUP) 4 protocol involves mass spectrometry (MS) analysis of peptides obtained from enzymatic digestion of whole proteins 4,5. Several software tools such as SEQUEST 6 , Mascot 7 and ExPASy tools 8 (FindPept 9 and EasyProt 10) have been reported for BUP data analysis. However, BUP spectra and its analysis have limited power in: (i) identification of post-translational modifications (PTMs) 2 , (ii) sequence coverage 11,12 , and (iii) characterization of very small proteins 13. Recent advancements in proteomics protocols and instrumentation have enabled precise mass measurements of large proteins by employing soft ionization techniques 14 coupled with high-resolution mass analyzers 15. This has led to the emergence of Top-Down Proteomics 16 (TDP) protocol which is becoming increasingly popular for analyzing intact proteins 17,18. TDP offers an enhanced sequence coverage 19 as compared to BUP 4 along with an improved identification of proteoforms (proteins and its variants) 20,21. However, the complexity of high-resolution TDP spectral data poses a significant challenge for analysis tools. Current tools for TDP include ProSight PTM 12 , ProSight PTM 2.0 22 , MS-Align+ 23 , pTop 24 , TopPIC 25 , and MSPathFinder 26 amongst others.

Journal of the American College of Cardiology

The Laryngoscope, Oct 9, 2016

To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of ... more To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of patients undergoing repair of lateral skull base defects and spontaneous cerebrospinal fluid leaks with the middle cranial fossa approach. Case series. 3D-printed temporal bone models-based on patient-specific, high-resolution computed tomographic imaging-were constructed using inexpensive polymer materials. Preoperatively, the models demonstrated the extent of temporal lobe retraction necessary to visualize the proposed defects in the lateral skull base. Also preoperatively, Silastic sheeting was arranged across the modeled tegmen, marked, and cut to cover all of the proposed defect sites. The Silastic sheeting was then sterilized and subsequently served as a precise intraoperative template for a synthetic dural replacement graft. Of note, these grafts were customized without needing to retract the temporal lobe. Five patients underwent the middle cranial fossa approach assisted by 3D-p...

Http Www Theses Fr, Jan 24, 2013

Indian Journal of Anaesthesia, 2016

Sexual dimorphisms in adrenal function and distinct behavioral patterns of aggression and "emotio... more Sexual dimorphisms in adrenal function and distinct behavioral patterns of aggression and "emotionality" in SJL and C57/BL6 mouse strains led to an intriguing question: are there strain-and/or gender-specific differences in the adrenal gland at the level of ion channels? In this study, we focused on the adrenal medulla, which is a critical component of the neuroendocrine system and responsible for modulating reactions to stress and regulation of various body processes including digestion, the immune system, mood, and energy usage. Secretion of epinephrine (EPI) from chromaffin cells of the adrenal medulla is tightly controlled by the electrophysiologial response generated from neural inputs. Several studies suggest that the intrinsic excitability of these cells is modulated by the number and kenetic properties of large-conductance calcium(2+)activated potassium ion channels (BK channels). Therefore, we focused on BK channels to study strain-and gender-specific differences in the adrenal gland at the level of ion channels. Stress-and sex-steroids have been shown to regulate alternative splicing of the pore-forming subunit of BK channels (Slo-α) in several experimental contexts, and associated β-subunits confer on BK channels distinct sensitivities to acute effects of stress-and sex-steroids. Using a real-time PCR technique, we examined mRNA levels for total Slo, STREX (a stress-regulated splice-variant of Slo), β2, and β4 in two mouse strains, SJL and C57/BL6. The experimental groups were: SJL males, SJL females, and C57/BL6 males. SJL males expressed significantly higher levels of mRNA for total Slo, β2, and β4 than SJL females and C57/BL6 males. STREX levels were not significantly different between the groups, probably due to a small sample size, but on average, SJL males had higher levels of expression than the other two groups. These results suggest 2 that SJL females and C57/BL6 males are relatively similar in their BK channel expression in the adrenals, while SJL males show distinct expression patterns. From this study, we now have grounds for hypothesizing functional relationships between behavior and adrenal function.

Otology & Neurotology, 2015

To describe the rationale, intraoperative details, and histopathologic findings discovered when t... more To describe the rationale, intraoperative details, and histopathologic findings discovered when treating an unusual case of apogeotropic horizontal canal positional vertigo with a transmastoid labyrinthectomy. A single case report. Therapeutic. Resolution of apogeotropic nystagmus and improvement of positional vertigo. The apogeotropic variant of horizontal canal positional vertigo can be a difficult entity to treat. This report describes a patient who developed profound sensorineural hearing loss and vertigo after an acute left labyrinthitis. Ten months later, she developed vertigo with apogeotropic positional nystagmus involving the left horizontal semicircular canal. Particle repositioning maneuvers and vestibular physical therapy were unsuccessful. In addition, she developed intermittent positional vertigo affecting the ipsilateral vertical semicircular canals. Given the persistence of her vertigo, multiple canal involvement, and patient preference for definitive treatment, a transmastoid labyrinthectomy was performed. Intraoperatively, the ampulla of the horizontal canal as well as that of the other canals was grossly abnormal as later confirmed on histology. After surgery, her apogeotropic nystagmus and vertigo resolved, and her balance ability gradually improved to a highly functional level. This case illustrates a unique form of positional vertigo that developed and persisted after acute labyrinthitis. Conservative measures were unsuccessful and a transmastoid labyrinthectomy documented dense inflammatory tissue involving all three ampullae. We postulate that the post-labyrinthitic inflammatory changes resulted in mass loading of the membranous ampullae, causing abnormal nystagmus patterns and positional vertigo, which resolved after the labyrinthectomy.

Techniques in Vascular and Interventional Radiology, 2015

The role of the interventional radiologist continues to expand in the treatment of biliary diseas... more The role of the interventional radiologist continues to expand in the treatment of biliary disease. Percutaneous transhepatic cholangioscopy (PTCS) provides direct visualization of the biliary system for diagnostic and therapeutic interventions, especially in cases where anatomical considerations prohibit a peroral approach. Visual inspection and endoscopically guided biopsy allow differentiation between benign and malignant lesions, as well as accurate assessment of the tumor extent for surgical planning. Studies have demonstrated greater than 95% accuracy with PTCS in diagnosing biliary malignancies. Cholangioscopy is also used to treat obstructive stones in the biliary system, which may require laser lithotripsy. PTCS-guided removal of biliary stones is highly successful, with complete stone removal from the bile ducts occurring in approximately 90% of cases. Overall, PTCS is a safe and effective procedure, with severe complications occurring in less than 8% of patients. The purpose of this review is to familiarize its reader with common indications for PTCS, techniques for procedural success, expected outcomes, and management of potential complications.

Oral submucous fibrosis is a disease of individuals of Indian-south east asian subcontinent, rela... more Oral submucous fibrosis is a disease of individuals of Indian-south east asian subcontinent, related to the use of areca nuts, also found in pan masala and guthka. It is possible that it is due to the copper content which increases col-lagen cross-linking. pale, blanched mucosa and palpable fibrotic bands may progress to severely restricted oral opening. It can also affect the soft palate and tongue and produces epithelial atrophy. Oral submucous fibrosis is a premalig-nant condition; carcinoma develops possibly in upto 8% cases. Diagnosis is based on history of betel chewing; typical clinical features; biopsy and haematology. Often anaemia is present. Treatment includes discontinuation of habits, oral physiotherapy, nutritional supplements, intralesional steroids and placental extracts and surgical interventions. This paper deals with a case of malignancy developing from oral submucous fibrosis in a 47 year old patient. Sushruta -a renowned Indian physician, in his book " mout...

PURPOSE To determine the prevalence of unsuspected thyroid nodules on MDCT of the chest, in a pop... more PURPOSE To determine the prevalence of unsuspected thyroid nodules on MDCT of the chest, in a population of adult outpatients imaged for indications other than thyroid disease. METHOD AND MATERIALS 3077 consecutive adult outpatient's IV contrast enhanced 16- and 64-MDCT scans of the chest were reviewed retrospectively, to identify unsuspected thyroid nodules. Exclusion criteria included history of thyroid cancer, known thyroid nodules or thyroid disease and risk factors for thyroid cancer, as evidenced by their medical records. One of 9 radiologists recorded number of nodules, location and bidirectional measurement of largest nodule, as well as amount of thyroid visualized on the chest CT. Presence of nodule was correlated with age, gender, race and percentage of thyroid imaged. RESULTS Included were 2510 subjects, 1288 men (51.3%) and 1222 (48.7%) women. Mean age was 59.3 years (range 18 - 94 years). Women more frequently had 1 nodule (206/1222 or 16.86% of women vs. 181/1288 o...

PURPOSE/AIM Renal cell carcinoma may recur years following nephrectomy. While the recurrence ofte... more PURPOSE/AIM Renal cell carcinoma may recur years following nephrectomy. While the recurrence often arises in the surgical bed, lung and liver as with other malignancies, it is not uncommon for disease to arise in more unusual locations. These include pancreas, stomach, thyroid and within muscles or subcutaneous tissues. Protocol optimization is essential, as these lesions are often small and inconspicuous when initially discovered. CONTENT ORGANIZATION Introduction Data acquisition: conspicuity is optimized with arterial phase imaging; are 4 acquisitions necessary in the post-nephrectomy patient? Interpretation: role of MPRs, volume rendering and maximum intensity projection to facilitate lesion identification CT findings: thyroid lung and mediastinum stomach liver pancreas adrenal nephrectomy bed contralateral kidney muscle subcutaneous bone Conclusion SUMMARY After reviewing this exhibit, the radiologist will be able to recognize the range of appearances of recurrent renal cell ca...

JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2014

The aim of this study was to compare frictional resistance which was produced between conventiona... more The aim of this study was to compare frictional resistance which was produced between conventional brackets (0.022 slot Otho-Organiser) and self ligating brackets (active Forestadent and passive Damon III) by using various arch wire combinations (0.016 Niti, 0.018 Niti, 0.017 x 0.025 SS and 0.019 x 0.025 SS). An experimental model which consisted of 5 aligned stainless steel 0.022-in brackets was used to assess frictional forces which were produced by SLBs (self ligating brackets) and CELs (conventional elastomeric ligatures) with use of 0.016 nickel titanium, 0.018 nickel titanium, 0.017 X 0.025"stainless steel and 0.019 X 0.025"stainless steel wires. One way ANOVA test was used to study the effect of the bracket type, wire alloy and section on frictional resistance test . Conventional brackets produced highest levels of friction for all bracket/archwire combinations. Both Damon III and Forestadent brackets were found to produce significantly lower levels of friction when they were compared with elastomerically tied conventional brackets. SLBs are valid alternatives for low friction during sliding mechanics.

World Journal of Radiology, 2013

The purpose of this pictorial essay is to review the common and uncommon sites of renal cell carc... more The purpose of this pictorial essay is to review the common and uncommon sites of renal cell carcinoma recurrence throughout the body by examining their appearances on computerized tomography (CT). CT imaging protocols will be discussed. The sites of recurrence have been categorized into 4 groups: chest and mediastinum, abdomen and pelvis, musculoskeletal, and neurological. For each site of recurrence, a representative CT image correlate with discussion is provided. The unique CT appearance of renal cell carcinoma recurrence and how it can be used in lesion detection will be discussed. Renal cell carcinoma recurrences are hypervascular like the primary tumor, which can aid in not only lesion detection but also in some cases, differentiation from other primary tumors. Through CT case review of various sites of recurrence, lesions are shown to be easily seen on arterial phase while sometimes being nearly inconspicuous on venous or delayed phases. Coronal and sagittal reconstructions can also improve diagnostic sensitivity. CT is the most commonly used imaging tool for surveillance of renal cell carcinoma recurrence after nephrectomy. Knowledge of sites of recurrence as well as the utility of arterial phase imaging and multiplanar reconstructions will aid in optimizing detection of disease recurrence.

International Journal of Pediatric Otorhinolaryngology, 2012

(a) To evaluate the efficacy of doxycycline as a percutaneous sclerotherapy agent in pediatric he... more (a) To evaluate the efficacy of doxycycline as a percutaneous sclerotherapy agent in pediatric head and neck macrocystic lymphatic malformations (LM) and (b) to review the literature with regard to recent developments in the treatment of lymphatic malformations using sclerotherapy. We reviewed the medical records and imaging studies of all patients who underwent percutaneous sclerotherapy of macrocystic LM of the head and neck at our institution between June 2005 and May 2010. All studies were reviewed and procedures performed by a single interventional neuroradiologist using computed tomography (CT) guidance. LM were individually cannulated, the contents aspirated, and then injected with doxycycline at concentrations of 10-20 mg/ml. Response to sclerotherapy was determined clinically. Seven patients underwent a total of eight sclerotherapy treatments during the study period. Of the six patients with appropriate follow-up, 67% have experienced complete or near-complete clinical resolution of their LM (1243 days mean follow-up), while 33% have developed recurrent swelling after an initial response following a single doxycycline injection (53 days mean follow-up). Our institutional results, in combination with recently published findings, support the moderate efficacy and excellent safety profile of percutaneous doxycycline sclerotherapy for macrocystic lymphatic malformations.

F1000 - Post-publication peer review of the biomedical literature, 2000

F1000 - Post-publication peer review of the biomedical literature, 2000

Indian Journal of Dentistry, 2011

Pemphigus vulgaris is a common oral mucosal disease characterized by the occurrence of chronic mu... more Pemphigus vulgaris is a common oral mucosal disease characterized by the occurrence of chronic multiple ulcerative lesions. Although exact etiology is not known, the underlying mechanism responsible for causing intra-epithelial lesion of pemphigus vulgaris is binding of IgG autoantibodies to desmoglein 3, a transmembrane glycoprotein adhesion molecule. The characteristic oral lesions of pemphigus vulgaris are thin-walled fl accid bullae arising on otherwise normal skin or mucosa. The bullae rupture and extend peripherally, giving a large area of denuded skin or mucosa. Here, we report a case of a 56-year-old female patient suffering from exacerbations and remissions of pemphigus vulgaris since last 2 years, with a detailed review of literature. The present case report emphasizes a need of detailed case history, thorough oral and systemic examination, investigative measures, and a proper treatment regimen.

JAMA Otolaryngology–Head & Neck Surgery, 2014

IMPORTANCE Although infarction after fine-needle aspiration (FNA) is a rare occurrence, it is a k... more IMPORTANCE Although infarction after fine-needle aspiration (FNA) is a rare occurrence, it is a known phenomenon that may lead to difficulties in interpretation for pathologists and in decision-making for head and neck surgeons. OBJECTIVE To characterize our experience with infarction in papillary thyroid carcinomas (PTCs) after FNA and review existing cases of infarcted PTCs in the literature to better understand this phenomenon. DESIGN, SETTING, AND PARTICIPANTS This was a retrospective case series and review of literature at a tertiary medical center (University of California, Los Angeles [UCLA], Medical Center). All patients who had a surgical pathologic diagnosis of infarcted PTC and who underwent FNA prior to surgery at UCLA from June 2006 to June 2012 were identified. There were 620 cases of PTC and 12 cases of infarcted PTC. MAIN OUTCOMES AND MEASURE Demographic data, FNA cytologic findings, and surgical pathologic data were gathered for each patient. A comprehensive literature search for infarcted PTC was performed. RESULTS Twelve cases of infarcted PTC were found in a total of 620 cases of PTC (1.9%). The mean (SD) time interval between the last FNA and surgery was 52 (35) days (range, 13-133 days). All patients received a diagnosis of infarcted PTC after thyroidectomy was performed. Focal infarction was found in 4 patients (33%), and near-total infarction was found in 8 patients (67%). Five patients (47%) had the follicular variant of PTC, making it the most common subtype in our series. A thorough literature search yielded 11 articles reporting a total of 26 cases of infarcted PTC after FNA. To our knowledge, our case series on infarcted PTC is the largest reported series in the literature. CONCLUSIONS AND RELEVANCE Although infarction of PTC after FNA occurs infrequently, it may lead to difficulties in histologic diagnosis. Awareness of this phenomenon and its histologic associations, along with careful reevaluation of the FNA and surgical specimens, is important for appropriate diagnosis and subsequent treatment. At this point, infarction in PTC should not alarm a head and neck surgeon to change management, but future prospective studies with a large population of patients with infarcted PTCs are needed to establish the impact of infarction on differences in treatment outcomes for therapies that may be used in PTCs.