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1.
Proteins ; 84(10): 1422-30, 2016 10.
Article in English | MEDLINE | ID: mdl-27315603

ABSTRACT

The pathogenic bacteria Legionella pneumophila is known to cause Legionnaires' Disease, a severe pneumonia that can be fatal to immunocompromised individuals and the elderly. Shohdy et al. identified the L. pneumophila vacuole sorting inhibitory protein VipF as a putative N-acetyltransferase based on sequence homology. We have characterized the basic structural and functional properties of VipF to confirm this original functional assignment. Sequence conservation analysis indicates two putative CoA-binding regions within VipF. Homology modeling and small angle X-ray scattering suggest a monomeric, dual-domain structure joined by a flexible linker. Each domain contains the characteristic beta-splay motif found in many acetyltransferases, suggesting that VipF may contain two active sites. Docking experiments suggest reasonable acetyl-CoA binding locations within each beta-splay motif. Broad substrate screening indicated that VipF is capable of acetylating chloramphenicol and both domains are catalytically active. Given that chloramphenicol is not known to be N-acetylated, this is a surprising finding suggesting that VipF is capable of O-acetyltransferase activity. Proteins 2016; 84:1422-1430. © 2016 Wiley Periodicals, Inc.


Subject(s)
Acetyl Coenzyme A/chemistry , Acetyltransferases/chemistry , Bacterial Proteins/chemistry , Chloramphenicol/chemistry , Legionella pneumophila/enzymology , Acetyl Coenzyme A/metabolism , Acetyltransferases/genetics , Acetyltransferases/metabolism , Amino Acid Sequence , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Catalytic Domain , Chloramphenicol/metabolism , Cloning, Molecular , Conserved Sequence , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression , Kinetics , Legionella pneumophila/chemistry , Molecular Dynamics Simulation , Plasmids/chemistry , Plasmids/metabolism , Protein Domains , Protein Structure, Secondary , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Alignment , Structural Homology, Protein , Structure-Activity Relationship , Substrate Specificity
2.
Biochem Mol Biol Educ ; 44(6): 526-536, 2016 Nov 12.
Article in English | MEDLINE | ID: mdl-27277577

ABSTRACT

Single nucleotide polymorphisms (SNPs) in DNA can result in phenotypes where the biochemical basis may not be clear due to the lack of protein structures. With the growing number of modeling and simulation software available on the internet, students can now participate in determining how small changes in genetic information impact cellular protein structure and function. We have developed a modular series of activities to engage lab or lecture students in examining the basis for common phenotypes. The activities range from basic phenotype testing/observation to DNA sequencing and simulation of protein structure and dynamics. We provide as an example study of the bitterness receptor TAS2R38 and PTC tasting, however these activities are applicable to other SNPs or genomic variants with a direct connection to an observable phenotype. These activities are modular and can be mixed to meet the student capabilities and infrastructure availability. The complete sequence of activities will demonstrate the direct connection between gene structure, protein structure and organism function. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(6):526-536, 2016.


Subject(s)
Biomedical Research/education , Computational Biology/education , Molecular Biology/education , Polymorphism, Single Nucleotide/genetics , Problem-Based Learning/methods , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Base Sequence , Curriculum , Educational Measurement , Genomics/methods , Humans , Laboratories , Models, Biological , Models, Molecular , Molecular Dynamics Simulation , Phenotype , Protein Conformation , Receptors, G-Protein-Coupled/chemistry , Sequence Analysis, DNA/methods , Sequence Homology, Nucleic Acid , Software , Structure-Activity Relationship , Students/psychology , Taste Perception/physiology , Teaching
3.
Am J Respir Crit Care Med ; 193(6): 673-80, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-26513613

ABSTRACT

RATIONALE: Recent reports of progressive massive fibrosis and rapidly progressive pneumoconiosis in U.S. coal miners have raised concerns about excessive exposures to coal mine dust, despite reports of declining dust levels. OBJECTIVES: To evaluate the histologic abnormalities and retained dust particles in available coal miner lung pathology specimens, and to compare these findings with those derived from corresponding chest radiographs. METHODS: Miners with severe disease and available lung tissue were identified through investigator outreach. Demographic as well as smoking and work history information was obtained. Chest radiographs were interpreted according to the International Labor Organization classification scheme to determine if criteria for rapidly progressive pneumoconiosis were confirmed. Pathology slides were scored by three expert pulmonary pathologists using a standardized nomenclature and scoring system. MEASUREMENTS AND MAIN RESULTS: Thirteen cases were reviewed, many of which had features of accelerated silicosis and mixed dust lesions. Twelve had progressive massive fibrosis, and 11 had silicosis. Only four had classic lesions of simple coal workers' pneumoconiosis. Four had diffuse interstitial fibrosis with chronic inflammation, and two had focal alveolar proteinosis. Polarized light microscopy revealed large amounts of birefringent mineral dust particles consistent with silica and silicates; carbonaceous coal dust was less prominent. On the basis of chest imaging studies, specimens with features of silicosis were significantly associated (P = 0.047) with rounded (type p, q, or r) opacities, whereas grade 3 interstitial fibrosis was associated (P = 0.02) with the presence of irregular (type s, t, or u) opacities. CONCLUSIONS: Our findings suggest that rapidly progressive pneumoconiosis in these miners was associated with exposure to coal mine dust containing high concentrations of respirable silica and silicates.


Subject(s)
Coal Mining , Lung/pathology , Silicates/adverse effects , Silicon Dioxide/adverse effects , Silicosis/pathology , Adolescent , Adult , Biopsy , Humans , Male , United States , Young Adult
4.
J Neurosurg ; 123(5): 1268-75, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26115468

ABSTRACT

OBJECT: Stereotactic radiosurgery (SRS) is a potentially important option for patients with skull base chondrosarcomas. The object of this study was to analyze the outcomes of SRS for chondrosarcoma patients who underwent this treatment as a part of multimodality management. METHODS: Seven participating centers of the North American Gamma Knife Consortium (NAGKC) identified 46 patients who underwent SRS for skull base chondrosarcomas. Thirty-six patients had previously undergone tumor resections and 5 had been treated with fractionated radiation therapy (RT). The median tumor volume was 8.0 cm3 (range 0.9-28.2 cm3), and the median margin dose was 15 Gy (range 10.5-20 Gy). Kaplan-Meier analysis was used to calculate progression-free and overall survival rates. RESULTS: At a median follow-up of 75 months after SRS, 8 patients were dead. The actuarial overall survival after SRS was 89% at 3 years, 86% at 5 years, and 76% at 10 years. Local tumor progression occurred in 10 patients. The rate of progression-free survival (PFS) after SRS was 88% at 3 years, 85% at 5 years, and 70% at 10 years. Prior RT was significantly associated with shorter PFS. Eight patients required salvage resection, and 3 patients (7%) developed adverse radiation effects. Cranial nerve deficits improved in 22 (56%) of the 39 patients who deficits before SRS. Clinical improvement after SRS was noted in patients with abducens nerve paralysis (61%), oculomotor nerve paralysis (50%), lower cranial nerve dysfunction (50%), optic neuropathy (43%), facial neuropathy (38%), trochlear nerve paralysis (33%), trigeminal neuropathy (12%), and hearing loss (10%). CONCLUSIONS: Stereotactic radiosurgery for skull base chondrosarcomas is an important adjuvant option for the treatment of these rare tumors, as part of a team approach that includes initial surgical removal of symptomatic larger tumors.


Subject(s)
Chondrosarcoma/surgery , Radiosurgery/methods , Skull Base Neoplasms/surgery , Adolescent , Adult , Aged , Chondrosarcoma/pathology , Combined Modality Therapy , Disease-Free Survival , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Nervous System Diseases/epidemiology , Nervous System Diseases/etiology , North America , Postoperative Care , Postoperative Complications/epidemiology , Skull Base Neoplasms/pathology , Survival Analysis , Treatment Outcome , Young Adult
5.
J Neurosurg ; 122(6): 1469-78, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25816088

ABSTRACT

OBJECT: The purpose of this study was to evaluate the role of stereotactic radiosurgery (SRS) in the management of intracranial hemangioblastomas. METHODS: Six participating centers of the North American Gamma Knife Consortium and 13 Japanese Gamma Knife centers identified 186 patients with 517 hemangioblastomas who underwent SRS. Eighty patients had 335 hemangioblastomas associated with von Hippel-Lindau disease (VHL) and 106 patients had 182 sporadic hemangioblastomas. The median target volume was 0.2 cm(3) (median diameter 7 mm) in patients with VHL and 0.7 cm(3) (median diameter 11 mm) in those with sporadic hemangioblastoma. The median margin dose was 18 Gy in VHL patients and 15 Gy in those with sporadic hemangioblastomas. RESULTS: At a median of 5 years (range 0.5-18 years) after treatment, 20 patients had died of intracranial disease progression and 9 patients had died of other causes. The overall survival after SRS was 94% at 3 years, 90% at 5 years, and 74% at 10 years. Factors associated with longer survival included younger age, absence of neurological symptoms, fewer tumors, and higher Karnofsky Performance Status. Thirty-three (41%) of the 80 patients with VHL developed new tumors and 17 (16%) of the106 patients with sporadic hemangioblastoma had recurrences of residual tumor from the original tumor. The 5-year rate of developing a new tumor was 43% for VHL patients, and the 5-year rate of developing a recurrence of residual tumor from the original tumor was 24% for sporadic hemangioblastoma patients. Factors associated with a reduced risk of developing a new tumor or recurrences of residual tumor from the original tumor included younger age, fewer tumors, and sporadic rather than VHL-associated hemangioblastomas. The local tumor control rate for treated tumors was 92% at 3 years, 89% at 5 years, and 79% at 10 years. Factors associated with an improved local tumor control rate included VHL-associated hemangioblastoma, solid tumor, smaller tumor volume, and higher margin dose. Thirteen patients (7%) developed adverse radiation effects (ARE) after SRS, and one of these patients died due to ARE. CONCLUSIONS: When either sporadic or VHL-associated tumors were observed to grow on serial imaging studies, SRS provided tumor control in 79%-92% of tumors.


Subject(s)
Brain Neoplasms/surgery , Hemangioblastoma/surgery , Neoplasm Recurrence, Local/surgery , Radiosurgery/instrumentation , von Hippel-Lindau Disease/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Brain Neoplasms/pathology , Disease Progression , Female , Hemangioblastoma/pathology , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Outcome Assessment, Health Care , Retrospective Studies , Treatment Outcome , Young Adult , von Hippel-Lindau Disease/pathology
6.
J Neurosurg ; 119(5): 1166-75, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23600932

ABSTRACT

OBJECT: Despite the widespread use of Gamma Knife surgery (GKS) for trigeminal neuralgia (TN), controversy remains regarding the optimal treatment dose and target site. Among the published studies, only a few have focused on long-term outcomes (beyond 2 years) using 90 Gy, which is in the higher range of treatment doses used (70-90 Gy). METHODS: The authors followed up on 315 consecutive patients treated with the Leksell Gamma Knife unit using a 4-mm isocenter without blocks. The isocenter was placed on the trigeminal nerve with the 20% isodose line tangential to the pontine surface (18 Gy). At follow-up, 33 patients were deceased; 282 were mailed an extensive questionnaire regarding their outcomes, but 32 could not be reached. The authors report their analysis of the remaining 250 cases. The patients' mean age at the time of survey response and the mean duration of follow-up were 70.8 ± 13.1 years and 68.9 ± 41.8 months, respectively. RESULTS: One hundred eighty-five patients (85.6%) had decreased pain intensity after GKS. Modified Marseille Scale (MMS) pain classifications after GKS at follow-up were: Class I (pain free without medication[s]) in 104 (43.7%), Class II (pain free with medication[s]) in 66 (27.7%), Class III (> 90% decrease in pain intensity) in 23 (9.7%), Class IV (50%-90% decrease in pain intensity) in 20 (8.4%), Class V (< 50% decrease in pain intensity) in 11 (4.6%), and Class VI (pain becoming worse) in 14 (5.9%). Therefore, 170 patients (71.4%) were pain free (Classes I and II) and 213 (89.5%) had at least 50% pain relief. All patients had pain that was refractory to medical management prior to GKS, but only 111 (44.4%) were being treated with medication at follow-up (p < 0.0001). Eighty patients (32.9%) developed numbness after GKS, and 74.5% of patients with numbness had complete pain relief. Quality of life and patient satisfaction on a 10-point scale were reported at mean values (± SD) of 7.8 ± 3.1 and 7.7 ± 3.4, respectively. Most of the patients (87.7%) would recommend GKS to another patient. Patients with prior surgical treatments had increased latency to pain relief and were more likely to continue medicines (p < 0.05). Moreover, presence of altered facial sensations prior to radiosurgery was associated with higher pain intensity, longer pain episodes, more frequent pain attacks, worse MMS pain classification, and more medication use after GKS (p < 0.05). Conversely, increase in numbness intensity after GKS was associated with a decrease in pain intensity and pain length (p < 0.05). CONCLUSIONS: Gamma Knife surgery using a maximum dose of 90 Gy to the trigeminal nerve provides satisfactory long-term pain control, reduces the use of medication, and improves quality of life. Physicians must be aware that higher doses may be associated with an increase in bothersome sensory complications. The benefits and risks of higher dose selection must be carefully discussed with patients, since facial numbness, even if bothersome, may be an acceptable trade-off for patients with severe pain.


Subject(s)
Pain/surgery , Radiosurgery/methods , Trigeminal Neuralgia/surgery , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pain/physiopathology , Pain Measurement , Patient Satisfaction , Quality of Life/psychology , Radiation Dosage , Radiosurgery/adverse effects , Time Factors , Treatment Outcome
7.
J Neurosurg ; 119(2): 446-56, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23621595

ABSTRACT

OBJECT: Pituitary adenomas are fairly common intracranial neoplasms, and nonfunctioning ones constitute a large subgroup of these adenomas. Complete resection is often difficult and may pose undue risk to neurological and endocrine function. Stereotactic radiosurgery has come to play an important role in the management of patients with nonfunctioning pituitary adenomas. This study examines the outcomes after radiosurgery in a large, multicenter patient population. METHODS: Under the auspices of the North American Gamma Knife Consortium, 9 Gamma Knife surgery (GKS) centers retrospectively combined their outcome data obtained in 512 patients with nonfunctional pituitary adenomas. Prior resection was performed in 479 patients (93.6%) and prior fractionated external-beam radiotherapy was performed in 34 patients (6.6%). The median age at the time of radiosurgery was 53 years. Fifty-eight percent of patients had some degree of hypopituitarism prior to radiosurgery. Patients received a median dose of 16 Gy to the tumor margin. The median follow-up was 36 months (range 1-223 months). RESULTS: Overall tumor control was achieved in 93.4% of patients at last follow-up; actuarial tumor control was 98%, 95%, 91%, and 85% at 3, 5, 8, and 10 years postradiosurgery, respectively. Smaller adenoma volume (OR 1.08 [95% CI 1.02-1.13], p = 0.006) and absence of suprasellar extension (OR 2.10 [95% CI 0.96-4.61], p = 0.064) were associated with progression-free tumor survival. New or worsened hypopituitarism after radiosurgery was noted in 21% of patients, with thyroid and cortisol deficiencies reported as the most common postradiosurgery endocrinopathies. History of prior radiation therapy and greater tumor margin doses were predictive of new or worsening endocrinopathy after GKS. New or progressive cranial nerve deficits were noted in 9% of patients; 6.6% had worsening or new onset optic nerve dysfunction. In multivariate analysis, decreasing age, increasing volume, history of prior radiation therapy, and history of prior pituitary axis deficiency were predictive of new or worsening cranial nerve dysfunction. No patient died as a result of tumor progression. Favorable outcomes of tumor control and neurological preservation were reflected in a 4-point radiosurgical pituitary score. CONCLUSIONS: Gamma Knife surgery is an effective and well-tolerated management strategy for the vast majority of patients with recurrent or residual nonfunctional pituitary adenomas. Delayed hypopituitarism is the most common complication after radiosurgery. Neurological and cranial nerve function were preserved in more than 90% of patients after radiosurgery. The radiosurgical pituitary score may predict outcomes for future patients who undergo GKS for a nonfunctioning adenoma.


Subject(s)
Adenoma/surgery , Hypopituitarism/surgery , Pituitary Neoplasms/surgery , Radiosurgery/instrumentation , Adenoma/complications , Adenoma/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Female , Humans , Hypopituitarism/etiology , Hypopituitarism/pathology , Male , Middle Aged , Pituitary Neoplasms/complications , Pituitary Neoplasms/pathology , Retrospective Studies , Treatment Outcome
8.
Chest ; 139(6): 1458-1462, 2011 Jun.
Article in English | MEDLINE | ID: mdl-20884728

ABSTRACT

BACKGROUND: Miners inhale dust at work and are at a risk for coal workers pneumoconiosis (CWP), a preventable and potentially fatal lung disease. After regulations were implemented in the 1970s, declines were reported in both dust levels and the prevalence of simple and advanced CWP until about 2001, when despite stable reported dust levels, disease levels sharply increased. METHODS: A structured, retrospective chart review was performed to describe the demographics and disease progression for 138 coal miners with progressive massive fibrosis (PMF) whose claims were approved by the West Virginia State Occupational Pneumoconiosis Board between January 2000 and December 2009. RESULTS: PMF, a complication of CWP, developed in 138 West Virginian coal miners at a mean age of 52.6 years after an average of 30 years work tenure. The time of progression averaged 12.2 years from the last normal chest radiograph until PMF was detected. Lung function declined sharply in both smokers and nonsmokers, averaging 87 mL/y for FEV(1) and 74 mL/y for FVC. The board has confirmed 21 deaths in this group. The most common job activities were operating continuous-mining machines (41%) and roof bolting (19%). Virtually all of these miners' dust exposures occurred after the implementation of current federal dust regulations. CONCLUSIONS: Contemporary occupational dust exposures have resulted over the past decade in rapidly progressive pneumoconiosis and massive fibrosis in relatively young West Virginian coal miners, leading to important lung dysfunction and premature death.


Subject(s)
Anthracosis/epidemiology , Coal Mining/legislation & jurisprudence , Occupational Exposure/adverse effects , Adult , Aged , Anthracosis/diagnostic imaging , Anthracosis/pathology , Cohort Studies , Disease Progression , Forced Expiratory Volume , Humans , Middle Aged , Occupational Exposure/legislation & jurisprudence , Radiography , Time Factors , Vital Capacity , West Virginia
9.
Expert Opin Drug Saf ; 8(4): 411-9, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19548859

ABSTRACT

Numerous neuroprotective compounds have been investigated to ameliorate secondary changes and the progression of injury after the primary insult in traumatic brain injury (TBI). This cascade of events is complex and difficult to abate once initiated following the primary injury. The clinical consequences of this secondary injury are unpredictable and often permanently incapacitating. Cyclosporine A (CsA) interrupts the endogenous mediators of secondary insult through inhibition of the mitochondrial permeability transition pore and prevention of subsequent mitochondrial dysfunction. This drug may have a role in neuroprotection but has several pharmacologic effects that must be considered when using it in the TBI population. This review discusses the physiologic responses following TBI that may affect CsA efficacy and safety when used for neuroprotective indications. So far, CsA seems to be safe in the TBI population. The role of CsA after acute TBI will be better defined after the completion of upcoming planned clinical trials.


Subject(s)
Brain Injuries/drug therapy , Cyclosporine/pharmacokinetics , Neuroprotective Agents/pharmacokinetics , Animals , Brain Injuries/complications , Cyclosporine/administration & dosage , Cyclosporine/adverse effects , Drug Administration Schedule , Humans , Models, Biological , Neuroprotective Agents/administration & dosage , Neuroprotective Agents/adverse effects
10.
J Neurol Sci ; 284(1-2): 182-5, 2009 Sep 15.
Article in English | MEDLINE | ID: mdl-19395024

ABSTRACT

Cystinosis is an autosomal recessive lysosomal storage disease that results in renal failure. CNS manifestations are rare. We report a 29-year man who presented with a cervical myelopathy due to cystinosis. Biopsy of the brain lesions demonstrated cystine crystal deposition and an intense perivascular with inflammatory vasculopathic changes. Symptomatic improvement attended the use of higher doses of cysteamine and corticosteroid therapy. Cystinosis of the nervous system may present as spinal cord disease and be associated with a CNS vasculopathy/vasculitis. As more patients with cystinosis experience long term survival, there will likely be an increased frequency of CNS disease.


Subject(s)
Central Nervous System/pathology , Cystine/analysis , Cystinosis/pathology , Myelitis/etiology , Vasculitis, Central Nervous System/etiology , Adult , Anti-Inflammatory Agents/therapeutic use , Biopsy, Needle , Central Nervous System/chemistry , Crystallization , Cysteamine/therapeutic use , Cystinosis/complications , Cystinosis/drug therapy , Cystinosis/metabolism , Cystinosis/surgery , Gait Disorders, Neurologic/etiology , Humans , Immunosuppressive Agents/therapeutic use , Kidney Transplantation , Magnetic Resonance Imaging , Male , Myelitis/drug therapy , Myelitis/pathology , Postoperative Complications/etiology , Reoperation , Sensation Disorders/etiology , Spinal Cord Compression/etiology , Vasculitis, Central Nervous System/drug therapy , Vasculitis, Central Nervous System/pathology
11.
J Neurosurg ; 109(4): 699-707, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18826358

ABSTRACT

OBJECT: Cyclosporine neuroprotection has been reported in brain injury models but safety and dosing guidelines have not been determined in humans with severe traumatic brain injury (TBI). The purpose of this investigation was to establish the safety of cyclosporine using 4 clinically relevant dosing schemes. METHODS: The authors performed a prospective, blinded, placebo-controlled, randomized, dose-escalation trial of cyclosporine administration initiated within 8 hours of TBI (Glasgow Coma Scale score range 4-8; motor score range 2-5). Four dosing cohorts (8 patients treated with cyclosporine and 2 receiving placebo treatment per cohort) received cyclosporine (1.25-5 mg/kg/day) or placebo in 2 divided doses (Cohorts I-III) or continuous infusion (Cohort IV) over 72 hours. Adverse events and outcome were monitored for 6 months. RESULTS: Forty patients were enrolled over 3 years (cyclosporine cohorts, 24 male and 8 female patients; placebo group, 8 male patients). Systemic trough concentrations were below 250 ng/ml during intermittent doses. Higher blood concentrations were observed in Cohorts III and IV. There was no significant difference in immunological effects, adverse events, infection, renal dysfunction, or seizures. Mortality rate was not affected by cyclosporine administration, independent of dose, compared with placebo (6 of 32 patients receiving cyclosporine and 2 of 8 receiving placebo died, p>0.05). At 6 months, a dose-related improvement in favorable outcome was observed in cyclosporine-treated patients (p<0.05). CONCLUSIONS: In patients with acute TBI who received cyclosporine at doses up to 5 mg/kg/day, administered intravenously, with treatment initiated within 8 hours of injury, the rate of mortality or other adverse events was not significantly different from that of the placebo group.


Subject(s)
Brain Injuries/drug therapy , Cyclosporine/administration & dosage , Cyclosporine/adverse effects , Immunosuppressive Agents/administration & dosage , Immunosuppressive Agents/adverse effects , Acute Disease , Adult , Dose-Response Relationship, Drug , Double-Blind Method , Female , Glasgow Coma Scale , Humans , Injections, Intravenous , Male , Middle Aged , Neuroprotective Agents/administration & dosage , Neuroprotective Agents/adverse effects , Placebos , Prospective Studies , Treatment Outcome
12.
Stereotact Funct Neurosurg ; 84(5-6): 193-204, 2006.
Article in English | MEDLINE | ID: mdl-16921255

ABSTRACT

PURPOSE: We have discovered a method for localization of the subthalamic nucleus (STN) utilizing the supramammillary commissure (SMC) as reference point. It is our purpose to present our experience and compare our methods with others. MATERIALS AND METHODS: Sixteen patients targeted for bilateral DBS for 32 total STN targets were studied by 1 mm MP-RAGE images with coronal T2W images. A modified red nucleus and mustache method was applied. The predicted target points were then confirmed with electronic calipers measuring the differences in methods. RESULTS: Modified red nucleus method using Surgiplan, and EBAL and BAGM electronic brain map atlas matched the target loci of 12 mm, -3 mm, -4 mm on an X-, Y-, and Z-coordinate system with zero at the mid-commissural point. From the coronal view Y is fixed at -3 mm. The mustache method was in error with values of X-axis at 14.25 (+/- 1.41 SD) (p = 0.69), and of Z-axis at -5.0 (+/- 1.60 SD) (p = 0.55). Three-fourths had moderate to marked ventricular enlargement of the III, but only 3 had enlargement of the frontal horns. CONCLUSION: The mustache method erred in the X-axis because the thalamocaudate groove was located lateral to the target point of the STN, and in the Z-axis because of varying thicknesses of the SMC. The top of the SMC is directly lateral from the STN target by 12 mm from the anterior and posterior commissures line. The SMC being a recognizable structure with constant relation to the STN should be the target structure.


Subject(s)
Parkinson Disease/pathology , Subthalamic Nucleus/pathology , Subthalamic Nucleus/physiology , Brain Mapping , Humans , Magnetic Resonance Imaging/methods , Stereotaxic Techniques , Subthalamic Nucleus/anatomy & histology
13.
Neurosurgery ; 58(3): 426-33; discussion 426-33, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16528181

ABSTRACT

OBJECTIVE: To evaluate the prevalence and characteristics of adverse drug reactions (ADRs) in neurosurgical intensive care patients. METHODS: Retrospective analysis of ADR data obtained from a spontaneous reporting system in a tertiary care university hospital. Reports of suspected ADRs in adult patients admitted emergently or electively to the neurosurgical service were included. RESULTS: Over the 3 year period, 3496 neurosurgical intensive care unit (ICU) patient admissions accounted for 5% of all hospital admissions. A total of 10% of all neurosurgical patients developed a suspected ADR, with three patients experiencing multiple reactions. Other adult ICU patients developed ADRs at a comparable rate (9%, P > 0.05). Overall, neurosurgery patients accounted for 12% of all spontaneously reported ADRs. Preventable reactions were observed in 43 (13%) cases, and treatment was required for 76%. The majority (96%) of ADRs resolved or improved at the time of the ADR report. Nausea, pruritus, thrombocytopenia, and vomiting were most frequently noted. Therapies most often associated with reported events were analgesics, antipyretics, antibiotics, anticonvulsants, and histamine H2 antagonists. The relationship between central nervous system disease and adverse event occurrence is not clear. CONCLUSION: Despite the narrow scope of drug regimens in neurosurgical ICU patients, ADRs can complicate therapy in this critically ill population. Neurosurgical ICU patients seem to experience ADRs no more frequently than their adult ICU counterparts.


Subject(s)
Adverse Drug Reaction Reporting Systems , Intensive Care Units , Neurosurgery , Adult , Analgesics/adverse effects , Anti-Bacterial Agents/adverse effects , Hospitalization , Humans , Nausea/chemically induced , Neurosurgery/methods , Prevalence , Pruritus/chemically induced , Retrospective Studies
15.
J Neurotrauma ; 23(1): 109-16, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16430377

ABSTRACT

Although the precise mechanism of action remains to be defined, Cyclosporin A (CsA) has demonstrated potential for neuroprotection in animal models. Predictive dosing strategies for CsA in acute traumatic brain injured (TBI) patients must account for the influence of the acute phase response on drug disposition. To characterize CsA pharmacokinetic parameters early following acute TBI, serial blood samples from patients enrolled into a Phase II dose-escalation trial were analyzed. Within eight hours of injury, thirty patients admitted with acute severe TBI were prospectively randomized into three cohorts (n = 8 CsA; n = 2 placebo per cohort) in this dose-escalation trial. Patients received one of three doses (I = 0.625 mg/kg/dose; II = 1.25 mg/kg/dose; III = 2.5 mg/kg/dose) or placebo intravenously every 12 h for 72 h. Serial blood collection began prior to dose 1 and continued for 72 h following the completion of six doses. Whole blood concentrations were determined by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Pharmacokinetic parameters were determined for each patient by fitting the concentration-time profile to a two-compartmental model with first order elimination. Mean area under the curve and predicted maximal blood concentration increased with each dosing cohort (I = 9840 h*microg/L, 398 microg/L; II = 18300 h*microg/L, 645 microg/L; III = 32500 h*microg/L, 1300 microg/L). Whole blood clearance, steady state volume of distribution, and beta half-life were independent of dose and higher than published reports from other populations: 0.420 L/h/kg, 5.91 L/kg, and 17.3 h, respectively. These data show patients with acute severe TBI demonstrate a more rapid clearance and a larger distribution volume of CsA. Pharmacokinetic parameters derived from this study will guide dosing strategies for future prospective clinical trials evaluating CsA therapy following acute TBI.


Subject(s)
Brain Injuries/drug therapy , Brain/drug effects , Cyclosporine/administration & dosage , Cyclosporine/pharmacokinetics , Acute Disease/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Brain/metabolism , Brain/physiopathology , Brain Injuries/metabolism , Brain Injuries/physiopathology , Cohort Studies , Cyclosporine/blood , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacology , Female , Humans , Male , Metabolic Clearance Rate/physiology , Middle Aged , Neuroprotective Agents/pharmacology , Placebos , Prospective Studies , Time Factors
16.
J Neurosurg ; 105(6): 843-52, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17405254

ABSTRACT

OBJECT: Hypermetabolism, hypercatabolism, refractory nitrogen wasting, hyperglycemia, and immunosuppression accompany traumatic brain injury (TBI). Pituitary dysfunction occurs, affecting growth hormone (GH) and plasma insulin-like growth factor-I (IGF-I) concentrations. The authors evaluated whether combination IGF-I/GH therapy improved metabolic and nutritional parameters after moderate to severe TBI. METHODS: The authors conducted a prospective, randomized, double-blind study comparing combination IGF-I/GH therapy and a placebo treatment. Ninety-seven patients with TBI were enrolled in the study within 72 hours of injury and were assigned to receive either combination IGF-I/GH therapy or placebo. All patients received concomitant nutritional support. Insulin-like growth factor-I was administered by continuous intravenous infusion (0.01 mg/kg/hr), and GH (0.05 mg/kg/day) was administered subcutaneously. Placebo control group patients received normal saline solution in place of both agents. Nutritional and metabolic monitoring continued throughout the 14-day treatment period. The two groups did not differ in energy expenditure, nutrient intake, or use of insulin treatment. The mean daily serum glucose concentration was higher in the treatment group (123 +/- 24 mg/dl) than in the control group (104 +/- 11 mg/dl) (p < 0.03). A positive nitrogen balance was achieved within the first 24 hours in the treatment group and remained positive in that group throughout the treatment period (p < 0.05). This pattern was not observed in the control group. Plasma IGF-I concentrations were above 350 ng/ml in the treatment group throughout the study period. Overall, the mean plasma IGF-I concentrations were 1003 +/- 480.6 ng/ml in the treatment group and 192 +/- 46.2 ng/ml in the control group (p < 0.01). CONCLUSIONS: The combination of IGF-I and GH produced sustained improvement in metabolic and nutritional endpoints after moderate to severe acute TBI.


Subject(s)
Brain Injuries/drug therapy , Energy Metabolism/drug effects , Human Growth Hormone/administration & dosage , Insulin-Like Growth Factor I/administration & dosage , Adult , Blood Glucose/metabolism , Brain Injuries/physiopathology , Double-Blind Method , Drug Therapy, Combination , Energy Metabolism/physiology , Female , Glasgow Coma Scale , Human Growth Hormone/blood , Humans , Infusions, Intravenous , Injections, Subcutaneous , Insulin-Like Growth Factor I/metabolism , Male , Middle Aged , Prospective Studies
18.
Lancet ; 366(9486): 643-8, 2005.
Article in English | MEDLINE | ID: mdl-16112300

ABSTRACT

BACKGROUND: The standard treatment for spinal cord compression caused by metastatic cancer is corticosteroids and radiotherapy. The role of surgery has not been established. We assessed the efficacy of direct decompressive surgery. METHODS: In this randomised, multi-institutional, non-blinded trial, we randomly assigned patients with spinal cord compression caused by metastatic cancer to either surgery followed by radiotherapy (n=50) or radiotherapy alone (n=51). Radiotherapy for both treatment groups was given in ten 3 Gy fractions. The primary endpoint was the ability to walk. Secondary endpoints were urinary continence, muscle strength and functional status, the need for corticosteroids and opioid analgesics, and survival time. All analyses were by intention to treat. FINDINGS: After an interim analysis the study was stopped because the criterion of a predetermined early stopping rule was met. Thus, 123 patients were assessed for eligibility before the study closed and 101 were randomised. Significantly more patients in the surgery group (42/50, 84%) than in the radiotherapy group (29/51, 57%) were able to walk after treatment (odds ratio 6.2 [95% CI 2.0-19.8] p=0.001). Patients treated with surgery also retained the ability to walk significantly longer than did those with radiotherapy alone (median 122 days vs 13 days, p=0.003). 32 patients entered the study unable to walk; significantly more patients in the surgery group regained the ability to walk than patients in the radiation group (10/16 [62%] vs 3/16 [19%], p=0.01). The need for corticosteroids and opioid analgesics was significantly reduced in the surgical group. INTERPRETATION: Direct decompressive surgery plus postoperative radiotherapy is superior to treatment with radiotherapy alone for patients with spinal cord compression caused by metastatic cancer.


Subject(s)
Decompression, Surgical , Spinal Cord Compression/etiology , Spinal Neoplasms/secondary , Spinal Neoplasms/surgery , Combined Modality Therapy , Female , Humans , Male , Middle Aged , Spinal Neoplasms/complications , Spinal Neoplasms/radiotherapy , Spine/surgery , Treatment Outcome , Walking
19.
J Neurosurg ; 102(2): 216-22, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15739547

ABSTRACT

OBJECT: Glial cell line-derived neurotrophic factor (GDNF) has demonstrated significant antiparkinsonian actions in several animal models and in a recent pilot study in England in which four of five patients received bilateral putaminal delivery. In the present study the authors report on a 6-month unilateral intraputaminal GDNF infusion in 10 patients with advanced Parkinson disease (PD). METHODS: Patients with PD in a functionally defined on and off state were evaluated 1 week before and 1 and 4 weeks after intraputaminal catheter implantation in the side contralateral to the most affected side. Each patient was placed on a dose-escalation regimen of GDNF: 3, 10, and 30 microg/day at successive 8-week intervals, followed by a 1-month wash-out period. The Unified Parkinson's Disease Rating Scale (UPDRS) total scores in the on and off states significantly improved 34 and 33%, respectively, at 24 weeks compared with baseline scores (95% confidence interval [CI] 18-47% for off scores and 16-51% for on scores). In addition, UPDRS motor scores in both the on and off states significantly improved by 30% at 24 weeks compared with baseline scores (95% CI 15-48% for off scores and 5-61% for on scores). Improvements occurred bilaterally, as measured by balance and gait and increased speed of hand movements. All significant improvements of motor function continued through the wash-out period. The only observed side effects were transient Lhermitte symptoms in two patients. CONCLUSIONS: Analysis of the data in this open-label study demonstrates the safety and potential efficacy of unilateral intraputaminal GDNF infusion. Unilateral administration of the protein resulted in significant, sustained bilateral effects.


Subject(s)
Antiparkinson Agents/administration & dosage , Dominance, Cerebral/drug effects , Motor Activity/drug effects , Nerve Growth Factors/administration & dosage , Parkinson Disease/drug therapy , Putamen/drug effects , Aged , Dominance, Cerebral/physiology , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Gait/drug effects , Gait/physiology , Glial Cell Line-Derived Neurotrophic Factor , Humans , Infusion Pumps, Implantable , Male , Middle Aged , Motor Activity/physiology , Parkinson Disease/diagnosis , Parkinson Disease/physiopathology , Postural Balance/drug effects , Postural Balance/physiology , Psychomotor Performance/drug effects , Psychomotor Performance/physiology , Putamen/physiopathology , Reaction Time/drug effects , Reaction Time/physiology , Treatment Outcome
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