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Biomedical subjects

M Blaivas

Publications and source records attributed to M Blaivas.

At least 37 records · Page 2Linked to original sources
PubMed2000

Quantification of intramuscular nerves within the female striated urogenital sphincter muscle.

OBJECTIVE: To analyze the quantity and distribution of intramuscular nerves within the striated urogenital sphincter and test the hypothesis that decreased nerve density is associated with decreased striated sphincter muscle and cadaver age. METHODS: Thirteen cadaveric urethras (mean age 47 years, range 15-78 years) were selected for study. A sagittal histologic section was stained with S100 stain to identify intramuscular nerves. The number of times that a nerve was seen within the striated urogenital sphincter (nerve number) was counted. The number of axons within each nerve fascicle was also counted. Regression analysis of nerve density against muscle cell number and age was performed. RESULTS: Remarkable variation was found in the quantity of intramuscular nerves in the striated urogenital sphincter of the 13 urethras studied. The number of nerves ranged from 72 to 543, a sevenfold variation (mean 247.1 +/- standard deviation 123.2), and the range of number of axons was 431 to 3523 (2201 +/- 1152.6). The larger nerve fascicles were seen predominantly in the distal (13.1 +/- 5.7 axons per nerve) compared with the proximal part of the striated urogenital sphincter (1.2 +/- 2). Reduced nerve density throughout the striated urogenital sphincter correlated with fewer muscle cells (P =.02). Nerve density also decreased with advancing age (P =.004). CONCLUSION: Remarkable variation in the quantity of intramuscular nerves was found. Women with sparse intramuscular nerves had fewer striated muscle cells. Intramuscular nerve density declined with age.

Adolescent↗
PubMed2000

Ultrasonographic diagnosis of testicular torsion by emergency physicians.

Testicular torsion has an incidence of one case per 4,000 men/boys. Most frequently affected are pubescent boys. Average testicular salvage rate is only 50%, and infertility can result Testicular torsion remains problematic for emergency physicians (EPs) as clinical diagnosis can be difficult and other testicular pathology can present similarly. In many institutions there are delays in obtaining Doppler or Scintigraphy studies during off-hours. We report two cases of testicular torsion diagnosed by the treating EPs using power Doppler in the emergency department (ED). Rapid diagnosis of torsion led to successful salvage of the affected testicle in both cases. These represent the first cases for emergency screening ultrasound examinations (ESUEs) of testicular torsion in the literature. Rapid technological advances over the last decade have brought portable equipment with high-resolution capability to the bed-side for EPs, who should consider using it more frequently to evaluate testicular torsion.

Adolescent↗
PubMed2000

Sinonasal undifferentiated carcinoma: case series and review of the literature.

OBJECTIVE AND IMPORTANCE: We report on four cases of sinonasal undifferentiated carcinoma (SNUC), a relatively newly described clinicopathological entity of the nasal cavity and paranasal sinuses. SNUC tends to present with advanced-stage disease, often with intracranial invasion, and requires an aggressive treatment approach that includes surgical resection. A review of the literature identified several reports of SNUC in pathology and otolaryngology journals since its initial description in 1986, but no report has yet appeared in the neurosurgery literature. CLINICAL PRESENTATION: Four patients presented with various symptoms related to the nose and/or orbit, including one or more of the following: obstruction, epistaxis, decreased visual acuity, diplopia, and pain. All patients were noted to have masses in the nasal cavity or paranasal sinuses, with or without intracranial extension. INTERVENTION: All four patients underwent multimodal treatment with chemotherapy, radiotherapy (60-65 Gy), and aggressive surgical resection via a combined bifrontal craniotomy and a subcranial approach to the anterior cranial fossa. Three of four patients died as a result of their disease, an average of 15 months after diagnosis. Only one patient remains alive, although with metastatic intracranial disease, at 24 months after diagnosis. CONCLUSION: SNUC is a rare neoplasm with a poor prognosis despite an aggressive multimodal approach to treatment. On the basis of our experience, we advocate radical resection as part of the initial combined therapy for patients who present with locally advanced, nonmetastatic disease but we suggest reserving surgery for patients with early brain invasion until there has been a radiographically proven central nervous system response to adjuvant therapy.

Adult↗
PubMed2000

Potential errors in the diagnosis of pericardial effusion on trauma ultrasound for penetrating injuries.

OBJECTIVE: To evaluate ultrasound error in patients presenting with penetrating injury with a potential for pericardial effusion. METHODS: Residents and faculty from an emergency medicine training program at Level 1 trauma center with an active ultrasound program were asked to view digitized video clips of subxiphoid cardiac examinations in patients with chest trauma. Participants were asked to fill out a standardized questionnaire on each video clip asking whether a pericardial effusion was present. Other questions included size of effusion and presence of tamponade. The study also asked participants to rate their confidence in their impressions. Data were analyzed using interquartile ranges and confidence levels. RESULTS: All participants had difficulty distinguishing between epicardial fat pads and true pericardial effusions. The overall sensitivity was 73% and specificity was 44%. Confidence shown by participants in their answers increased with level of training or experience, regardless of whether they were correct or incorrect. Additional views were frequently requested to help decide whether an effusion was present. CONCLUSIONS: A serious potential exists for misdiagnosing epicardial fat pads as pericardial effusion in critically ill trauma patients. Emergency physicians need to be aware of this and should consider one of two suggested alternative methods to improve the accuracy of diagnosis.

Adult↗
PubMed2000

Lower-extremity Doppler for deep venous thrombosis--can emergency physicians be accurate and fast?

UNLABELLED: Clinical diagnosis of lower-extremity (LE) deep venous thrombosis (DVT) requires confirmation by an imaging study before committing the patient to anticoagulation therapy. Studies have shown that demonstrating compressibility of leg veins under ultrasound is accurate for ruling out DVTs when performed by vascular specialists. Although LE Doppler has become the preferred test for diagnosing DVTs, it is not always available 24 hours per day. OBJECTIVES: To evaluate the accuracy and speed with which emergency physicians (EPs) could perform LE color duplex ultrasonography for the detection of DVT. METHODS: Patients presenting to an urban community emergency department (ED) between August 1, 1998, and March 3, 1999, were enrolled into this prospective study. The EPs, who underwent brief and standardized training, scanned patients at high risk for DVT with leg pain, swelling, or both. Physicians performed color duplex ultrasound examinations with compression at the common femoral and popliteal veins. The time until completion of the ED scan was recorded with a standardized method. The vascular laboratory performed a complete duplex ultrasound examination within eight hours. RESULTS: One hundred twelve patients were enrolled in the study, with 34 positive for DVT. The median examination time was 3 minutes 28 seconds (95% CI = 2 min 45 sec to 4 min 2 sec; IQR 3 min 9 sec). Times ranged from 1:02 to 18:20 minutes. The ED results had a high correlation with vascular laboratory studies, giving a kappa of 0.9 and a 98% agreement (95% CI = 95.4% to 100%). CONCLUSION: Emergency physicians can perform LE duplex ultrasound examinations accurately and quickly.

Clinical Competence↗
PubMed2000

Do emergency physicians save time when locating a live intrauterine pregnancy with bedside ultrasonography?

OBJECTIVE: To determine whether patients presenting to the emergency department (ED) with first-trimester pregnancy complications have a decreased length of stay (LOS) when a live intrauterine pregnancy (IUP) is diagnosed by emergency physicians (EPs). METHODS: This study was performed at an urban community ED with a residency program and an annual census of 65,000. A retrospective chart review from October 1995 to August 1998 identified 1,419 patients who received ultrasound examinations confirming live IUP in the first trimester with pain and/or bleeding. Two hundred seventy-seven of these patients received their ultrasound examinations from EPs; 1, 142 patients received a study from radiology and were not scanned by EPs. The LOSs for the two groups were compared and defined as the time from being placed into a room to discharge from the ED. Significance was determined using a two-tailed t-test. Median times with confidence intervals were calculated. RESULTS: When patients had a live IUP confirmed by an EP, the median LOS was 21% (59 min) less than those who received an ultrasound examination by radiology (p = 0.0001; 95% CI = 49 min to 1 hr 17 min). When evaluated by time of day, patients who presented after hours (6 PM to 6 AM) and were scanned by EPs spent 28% (1 hr 17 min) less time in the ED (p = 0.0001; 95% CI = 55 min to 1 hr 37 min). CONCLUSIONS: Emergency physicians identifying live IUP with bedside ultrasonography significantly decreased patients' LOSs in the ED. The decrease in LOS was most apparent for patients presenting during evening and nighttime hours.

Emergency Service, Hospital↗
PubMed1999

Brain biopsy in primary angiitis of the central nervous system.

To determine the yield of brain biopsy and the predictive value of clinical features and ancillary studies, we retrospectively analyzed hospital chart data from 61 consecutive patients suspected of having primary angiitis of the CNS (PACNS). Biopsies disclosed PACNS in 22 (36%), alternative diagnoses in 24 (39%), and no diagnosis in 15 (25%). Clinical indicators and angiography were not useful predictors of PACNS. Brain biopsy should be the primary diagnostic tool in this setting because of the poor reliability of other indicators and because of the high yield of alternative diagnoses requiring different management.

Biopsy↗
PubMed1999

Metastatic adenocarcinoma to the brain mimicking hemorrhage: case report.

BACKGROUND: Computerized tomography (CT) of metastatic adenocarcinoma to the brain usually shows low-to-moderate attenuation. However, mucinous adenomas may appear with high attenuation, mimicking hemorrhage. CASE DESCRIPTION: A 68-year-old man with a history of metastatic esophageal adenocarcinoma presented to the emergency room complaining of a chronic, progressive right occipital headache. A head CT demonstrated a moderate-to-high attenuation, homogenous mass in the right cerebellar hemisphere consistent with an intracerebral hemorrhage. There was no frank calcification in the mass by CT criteria. An emergent posterior fossa craniectomy revealed nonhemorrhagic metastatic mucinous adenocarcinoma. CONCLUSION: Moderate-to-high attenuation, noncalcified brain masses should raise the possibility of mucin-containing neoplasm.

Adenocarcinoma, Mucinous↗
PubMed1999

Lafora disease: diagnosis by skin biopsy.

Lafora disease is a fatal neurometabolic disorder characterized by progressive myoclonic epilepsy. Diagnosis relies upon the discovery of specific inclusion bodies in any of several organs. Dermatologists and dermatopathologists should be familiar with this condition because axillary skin biopsy is useful to diagnose this disorder. We present a case of Lafora disease diagnosed by axillary skin biopsy and review the condition's clinical, histologic, and ultrastructural features.

Adolescent↗
PubMed1999

Thyroid gland hematoma after blunt cervical trauma.

Thyroid hematoma is a rare cause of airway obstruction in victims of blunt trauma. The case of a 34-year-old woman who developed orthopnea after a low-energy motor vehicle accident is described. Presenting greater than 24 hours after her accident, the patient noted dysphagia, tracheal deviation, and postural dyspnea. The diagnosis of thyroid gland hematoma was made with a combination of fiberoptic laryngoscopy, cervical computed tomography, and great vessel and carotid angiography. Invasive airway management was not required. The patient underwent a total thyroidectomy and recovered without complications.

Accidents, Traffic↗
PubMed1999

Decreasing length of stay with emergency ultrasound examination of the gallbladder.

OBJECTIVE: To determine whether patients who received emergency screening ultrasound examinations (ESUEs) of the gallbladder by emergency physicians (EPs) have a shorter ED length of stay (LOS) than do those receiving ultrasound studies from radiology. METHODS: A retrospective chart review from July 1995 to August 1998 identified 1,242 patients who received gallbladder ultrasound examinations. Seven hundred fifty-three patients received ESUEs by EPs of varying levels of ultrasound experience. Four hundred eighty-nine patients received gallbladder ultrasound examinations from radiology, and were not scanned by EPs. The LOSs of the two groups were compared. Significance was evaluated using a two-tailed t-test. RESULTS: When patients received an ESUE by an EP, the median LOS was 7% (22 min) less than that for those who received an ultrasound examination by radiology (p = 0.017; 95% CI = 4 min to 41 min). When evaluated by disposition, patients discharged home and scanned by EPs had their median LOSs shortened by 11% or 32 minutes (p = 0.02; 95% CI = 5 min to 55 min). When evaluated by time of day, patients who presented after hours (6 PM-6 AM) and were scanned by EPs spent 15% (52 min) less time in the ED (p = 0.0002; 95% CI = 26 min to 89 min). Those who were seen after hours and discharged home had their LOSs shortened by 20% (1 hr, 13 min, p = 0.001; 95% CI = 28 min to 1 hr, 56 min). CONCLUSIONS: In a teaching hospital with a residency program, ESUEs decrease ED LOS for these patients. The difference was most apparent for patients presenting after hours.

Emergency Medical Services↗
PubMed1999

Adenoviral nerve growth factor and beta-galactosidase transfer to spinal cord: a behavioral and histological analysis.

OBJECT: The present study characterizes the time course and loci of gene expression induced by the administration of adenoviral vectors into spinal cord. Although a marked inflammatory response to these vectors occurred, no effect on spinal cord function was seen in the 1st postoperative week. The expression of transgenic genes delivered by viral vectors is being exploited throughout the nervous system. The present study utilized adenoviral vectors containing the Rous sarcoma virus (RSV) promoter and a nuclear localization signal to achieve transgenic expression in mammalian spinal cord. METHODS: Initial experiments utilizing the vector Ad.RSVlacZ (10(12) particles/ml) injected into the region of the central canal resulted in viral gene expression stretching over approximately 1.2 cm of spinal cord. Gene expression was first detected 3 days following viral administration and lasted until postinjection Day 14 with peak expression at Day 7. A variety of cell types in both white and gray matter expressed lacZ. Transgenic expression of the neurotrophin nerve growth factor (NGF) was achieved using injections of Ad.RSVNGF. On histological examination mononuclear inflammatory infiltrate and gliosis were revealed surrounding the injection sites of spinal cords receiving adenovirus but not vehicle. To assess spinal cord function during viral gene expression, animals previously trained in an operant runway task were tested at 7 days postinjection (the peak of viral gene expression) and demonstrated no changes in spinal cord function. CONCLUSIONS: Results of this study using adenoviral neurotrophic gene transfer indicate that it provided an effective tool for the delivery of potentially therapeutic proteins to the injured or diseased spinal cord.

Adenoviridae↗
PubMed1998

Molecular lysis of synovial lining cells by in vivo herpes simplex virus-thymidine kinase gene transfer.

Herpes simples virus thymidine kinase (HSV-TK) expression plasmid DNA was injected into the joint space of rabbits with antigen-induced arthritis (AIA). Purified plasmid DNA was able to mediate transfection of synovial lining cells and transient overexpression of HSV-TK in the context of active synovial inflammation. The pharmacodynamic distribution of intraarticular expression plasmid DNA was confined to the joint space. Arthritic rabbits treated with intraarticular expression plasmid DNA followed by intravenous ganciclovir (GCV, 5 mg/kg) twice daily for 3 days showed histologic evidence of synovial lining layer cytolysis when articular tissues were examined 21 days posttreatment. There was also a reduction in joint swelling in the TK-treated knees. No untoward clinical effects were observed in the rabbits and no evidence of cytolytic damage specific to the TK-GCV gene therapy was observed either in the articular cartilage or bone. The application of TK-GCV intraarticular gene therapy using purified expression plasmid DNA for the induction of synovial cytolysis may be applicable to the treatment of human inflammatory arthritis.

Animals↗
PubMed1998

Influence of head trauma on outcome following anterior temporal lobectomy.

BACKGROUND: There is controversy in the literature regarding the importance of risk factors in developing epilepsy and seizure outcome following anterior temporal lobectomy. Some of the existing studies may be biased because of patient selection and limitations in determining predisposition. OBJECTIVE: To investigate the role of risk factors for epilepsy in determining outcome following anterior temporal lobectomy. PATIENTS AND METHODS: We identified 102 patients in a consecutive surgery series for epilepsy from a tertiary center with a minimum of 1-year postoperative follow-up. Risk factors for epilepsy were determined prospectively on at least 3 occasions before anterior temporal lobectomy. Risk factors investigated were a history of febrile convulsions, family history of epilepsy, significant head trauma, history of meningitis, history of encephalitis, or significant perinatal insult. Foreign tissue lesions on magnetic resonance imaging was also included if an anterior temporal lobectomy was performed for presumed dual pathologic findings (hippocampus and lesion). Outcome was determined using Engel's classification. For statistical analysis we used successive logistic regression analysis, chi(2) test, Fisher exact test, and t test. RESULTS: Of the 102 patients, 13 had no identified risk factor for epilepsy, 49 had 1 identified risk factor, and 40 had more than 1. Frequencies were 39 febrile convulsions (15 complex febrile convulsions), 29 head trauma, 22 with lesions seen on magnetic resonance imaging, 12 history of meningitis, 2 history of encephalitis, 19 family history of epilepsy, and 4 perinatal insult. Seventy-one (70%) were classified as Engel's class I, with 56 patients continuously free of seizures at follow-up. Those without risk factor were as likely to be rendered free of seizures following anterior temporal lobectomy as those with a risk factor (P = .27). No risk factor alone or in combination was correlated with complete freedom from seizures following anterior temporal lobectomy, but the presence of head trauma, alone or in combination, was correlated with continued seizures following anterior temporal lobectomy (P = .03; odds ratio, 2.6). Better outcomes were not seen in those with head trauma before the age of 5 years (P = .57). These findings did not change if all those with lesions on magnetic resonance imaging were excluded in the analysis. Those with a history of head trauma were as likely to have pathologic evidence of mesial temporal sclerosis as others (P = .82). CONCLUSIONS: Patients with a history of significant head trauma are less likely to become free of seizures following anterior temporal lobectomy. No other risk factor correlated with a statistically significant greater or lesser chance of freedom from seizures. This information may be used in preoperative counseling of patients.

Adult↗