Saman Farr - Academia.edu (original) (raw)
Papers by Saman Farr
Journal of Neurological Surgery Reports, 2015
Central nervous system (CNS) histoplasmosis is rare and difficult to diagnose because it is often... more Central nervous system (CNS) histoplasmosis is rare and difficult to diagnose because it is often overlooked or mistaken for other pathologies due to its nonspecific symptoms. A 32-year-old Hispanic man with advanced acquired immunodeficiency virus presented with altered mental status and reported confusion for the past 3 months. He had a Glasgow Coma Scale of 12, repetitive nonfluent speech, and a disconjugate gaze with a right gaze preference. Lung computed tomography (CT) findings indicated a pulmonary histoplasmosis infection. Magnetic resonance imaging of the brain revealed a ring-enhancing lesion in the left caudate nucleus. A CT-guided left retroperitoneal node biopsy was performed and indicated a benign inflammatory process with organisms compatible with fungal yeast. Treatment with amphotericin B followed by itraconazole was initiated in spite of negative cerebrospinal fluid (CSF) cultures and proved effective in mitigating associated CNS lesions and resolving neurologic deficits. The patient was discharged 3 weeks later in stable condition. Six weeks later, his left basal ganglia mass decreased. Early recognition of symptoms and proper steps is key in improving outcomes of CNS histoplasmosis. Aggressive medical management is possible in the treatment of intracranial deep mass lesions, and disseminated histoplasmosis with CNS involvement can be appropriately diagnosed and treated, despite negative CSF and serology studies.
Protein science : a publication of the Protein Society, 2007
Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure ... more Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure determination. Here we propose and test a new approach to crystallization, in which the crystallization target is fused to a polymerizing protein module, so that polymer formation drives crystallization of the target. We test the approach using a polymerization module called 2TEL, which consists of two tandem sterile alpha motif (SAM) domains from the protein translocation Ets leukemia (TEL). The 2TEL module is engineered to polymerize as the pH is lowered, which allows the subtle modulation of polymerization needed for crystal formation. We show that the 2TEL module can drive the crystallization of 11 soluble proteins, including three that resisted prior crystallization attempts. In addition, the 2TEL module crystallizes in the presence of various detergents, suggesting that it might facilitate membrane protein crystallization. The crystal structures of two fusion proteins show that the...
Journal of Neurological Surgery Part B: Skull Base, 2014
Surgical Neurology International, 2015
Seizures account for significant morbidity and mortality early in the course of traumatic brain i... more Seizures account for significant morbidity and mortality early in the course of traumatic brain injury (TBI). Although there is sufficient literature suggesting short-term benefits of antiepileptic drugs (AEDs) in post-TBI patients, there has been no study to suggest a time frame for continuing AEDs in patients who have undergone a decompressive craniectomy for more severe TBI. We examined trends in a level-II trauma center in southern California that may provide guidelines for AED treatment in craniectomy patients. A retrospective analysis was performed evaluating patients who underwent decompressive craniectomy and those who underwent a standard craniotomy from 2008 to 2012. Out of the 153 patients reviewed, 85 were included in the study with 52 (61%) craniotomy and 33 (39%) craniectomy patients. A total of 78.8% of the craniotomy group used phenytoin (Dilantin), 9.6% used levetiracetam (Keppra), 5.8% used a combination of both, and 3.8% used topiramate (Topamax). The craniectomy group used phenytoin 84.8% and levetiracetam 15.2% of the time without any significant difference between the procedural groups. Craniotomy patients had a 30-day seizure rate of 13.5% compared with 21.2% in craniectomy patients (P = 0.35). Seizure onset averaged on postoperative day 5.86 for the craniotomy group and 8.14 for the craniectomy group. There was no significant difference in the average day of seizure onset between the groups P = 0.642. Our study shows a trend toward increased seizure incidence in craniectomy group, which does not reach significance, but suggests they are at higher risk. Whether this higher risk translates into a benefit on being on AEDs for a longer duration than the current standard of 7 days cannot be concluded as there is no significant difference or trend on the onset date for seizures in either group. Moreover, a prospective study will be necessary to more profoundly evaluate the duration of AED prophylaxis for each one of the stated groups.
Protein Science, 2007
Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure ... more Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure determination. Here we propose and test a new approach to crystallization, in which the crystallization target is fused to a polymerizing protein module, so that polymer formation drives crystallization of the target. We test the approach using a polymerization module called 2TEL, which consists of two tandem sterile alpha motif (SAM) domains from the protein translocation Ets leukemia (TEL). The 2TEL module is engineered to polymerize as the pH is lowered, which allows the subtle modulation of polymerization needed for crystal formation. We show that the 2TEL module can drive the crystallization of 11 soluble proteins, including three that resisted prior crystallization attempts. In addition, the 2TEL module crystallizes in the presence of various detergents, suggesting that it might facilitate membrane protein crystallization. The crystal structures of two fusion proteins show that the TELSAM polymer is responsible for the majority of contacts in the crystal lattice. The results suggest that biological polymers could be designed as crystallization modules.
Case Reports in Clinical Medicine, 2013
Background: The purpose of this case report is to present an unusual and unique case of vertebral... more Background: The purpose of this case report is to present an unusual and unique case of vertebral osteomyelitis due to the organism Cryptococcus neoformans, which was found to be isolated to the fourth lumbar vertebra in an immunocompetent patient. Cryptotoccus neoformans is an encapsulated yeast which typically presents in severely immunocompromised patients. Vertebral osteomyelitis is most commonly associated with bacterial infections. Case Description: A 51-year-old male presented with severe pain localized to the lumbar region, and a high grade fever for 15 days, chills, urinary hesitancy, dysuria, and fatigue. The patient's only past medical history included Type II Diabetes Mellitus. Neoplasms and HIV were ruled out. No source of entry was located upon examination and the lungs were negative for the presence of Cryptococcal pathogen. The CT scan revealed a lytic lesion located in the fourth lumbar vertebral body. A bone biopsy confirmed the presence of Cryptococcus neoformans as the source of infection. A follow up visit was also conducted to examine the patient's status of infection, and for the presence of complications. Conclusion: At this time, it is important to note Cryptococcus neoformans can be isolated to a single vertebral level. This case study is pivotal in demonstrating the importance of the comprehension of rare, and non-traumatic Cryptococcal infections in Central Nervous System, showing also that immunocompetent patients are well at risk for this infectious process.
Journal of Neurological Surgery Reports, 2015
Central nervous system (CNS) histoplasmosis is rare and difficult to diagnose because it is often... more Central nervous system (CNS) histoplasmosis is rare and difficult to diagnose because it is often overlooked or mistaken for other pathologies due to its nonspecific symptoms. A 32-year-old Hispanic man with advanced acquired immunodeficiency virus presented with altered mental status and reported confusion for the past 3 months. He had a Glasgow Coma Scale of 12, repetitive nonfluent speech, and a disconjugate gaze with a right gaze preference. Lung computed tomography (CT) findings indicated a pulmonary histoplasmosis infection. Magnetic resonance imaging of the brain revealed a ring-enhancing lesion in the left caudate nucleus. A CT-guided left retroperitoneal node biopsy was performed and indicated a benign inflammatory process with organisms compatible with fungal yeast. Treatment with amphotericin B followed by itraconazole was initiated in spite of negative cerebrospinal fluid (CSF) cultures and proved effective in mitigating associated CNS lesions and resolving neurologic deficits. The patient was discharged 3 weeks later in stable condition. Six weeks later, his left basal ganglia mass decreased. Early recognition of symptoms and proper steps is key in improving outcomes of CNS histoplasmosis. Aggressive medical management is possible in the treatment of intracranial deep mass lesions, and disseminated histoplasmosis with CNS involvement can be appropriately diagnosed and treated, despite negative CSF and serology studies.
Protein science : a publication of the Protein Society, 2007
Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure ... more Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure determination. Here we propose and test a new approach to crystallization, in which the crystallization target is fused to a polymerizing protein module, so that polymer formation drives crystallization of the target. We test the approach using a polymerization module called 2TEL, which consists of two tandem sterile alpha motif (SAM) domains from the protein translocation Ets leukemia (TEL). The 2TEL module is engineered to polymerize as the pH is lowered, which allows the subtle modulation of polymerization needed for crystal formation. We show that the 2TEL module can drive the crystallization of 11 soluble proteins, including three that resisted prior crystallization attempts. In addition, the 2TEL module crystallizes in the presence of various detergents, suggesting that it might facilitate membrane protein crystallization. The crystal structures of two fusion proteins show that the...
Journal of Neurological Surgery Part B: Skull Base, 2014
Surgical Neurology International, 2015
Seizures account for significant morbidity and mortality early in the course of traumatic brain i... more Seizures account for significant morbidity and mortality early in the course of traumatic brain injury (TBI). Although there is sufficient literature suggesting short-term benefits of antiepileptic drugs (AEDs) in post-TBI patients, there has been no study to suggest a time frame for continuing AEDs in patients who have undergone a decompressive craniectomy for more severe TBI. We examined trends in a level-II trauma center in southern California that may provide guidelines for AED treatment in craniectomy patients. A retrospective analysis was performed evaluating patients who underwent decompressive craniectomy and those who underwent a standard craniotomy from 2008 to 2012. Out of the 153 patients reviewed, 85 were included in the study with 52 (61%) craniotomy and 33 (39%) craniectomy patients. A total of 78.8% of the craniotomy group used phenytoin (Dilantin), 9.6% used levetiracetam (Keppra), 5.8% used a combination of both, and 3.8% used topiramate (Topamax). The craniectomy group used phenytoin 84.8% and levetiracetam 15.2% of the time without any significant difference between the procedural groups. Craniotomy patients had a 30-day seizure rate of 13.5% compared with 21.2% in craniectomy patients (P = 0.35). Seizure onset averaged on postoperative day 5.86 for the craniotomy group and 8.14 for the craniectomy group. There was no significant difference in the average day of seizure onset between the groups P = 0.642. Our study shows a trend toward increased seizure incidence in craniectomy group, which does not reach significance, but suggests they are at higher risk. Whether this higher risk translates into a benefit on being on AEDs for a longer duration than the current standard of 7 days cannot be concluded as there is no significant difference or trend on the onset date for seizures in either group. Moreover, a prospective study will be necessary to more profoundly evaluate the duration of AED prophylaxis for each one of the stated groups.
Protein Science, 2007
Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure ... more Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure determination. Here we propose and test a new approach to crystallization, in which the crystallization target is fused to a polymerizing protein module, so that polymer formation drives crystallization of the target. We test the approach using a polymerization module called 2TEL, which consists of two tandem sterile alpha motif (SAM) domains from the protein translocation Ets leukemia (TEL). The 2TEL module is engineered to polymerize as the pH is lowered, which allows the subtle modulation of polymerization needed for crystal formation. We show that the 2TEL module can drive the crystallization of 11 soluble proteins, including three that resisted prior crystallization attempts. In addition, the 2TEL module crystallizes in the presence of various detergents, suggesting that it might facilitate membrane protein crystallization. The crystal structures of two fusion proteins show that the TELSAM polymer is responsible for the majority of contacts in the crystal lattice. The results suggest that biological polymers could be designed as crystallization modules.
Case Reports in Clinical Medicine, 2013
Background: The purpose of this case report is to present an unusual and unique case of vertebral... more Background: The purpose of this case report is to present an unusual and unique case of vertebral osteomyelitis due to the organism Cryptococcus neoformans, which was found to be isolated to the fourth lumbar vertebra in an immunocompetent patient. Cryptotoccus neoformans is an encapsulated yeast which typically presents in severely immunocompromised patients. Vertebral osteomyelitis is most commonly associated with bacterial infections. Case Description: A 51-year-old male presented with severe pain localized to the lumbar region, and a high grade fever for 15 days, chills, urinary hesitancy, dysuria, and fatigue. The patient's only past medical history included Type II Diabetes Mellitus. Neoplasms and HIV were ruled out. No source of entry was located upon examination and the lungs were negative for the presence of Cryptococcal pathogen. The CT scan revealed a lytic lesion located in the fourth lumbar vertebral body. A bone biopsy confirmed the presence of Cryptococcus neoformans as the source of infection. A follow up visit was also conducted to examine the patient's status of infection, and for the presence of complications. Conclusion: At this time, it is important to note Cryptococcus neoformans can be isolated to a single vertebral level. This case study is pivotal in demonstrating the importance of the comprehension of rare, and non-traumatic Cryptococcal infections in Central Nervous System, showing also that immunocompetent patients are well at risk for this infectious process.