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Biomedical subjects

M Bernstein

Publications and source records attributed to M Bernstein.

At least 37 records · Page 2Linked to original sources
PubMed1998

Incidence of silent hemorrhage and delayed deterioration after stereotactic brain biopsy.

OBJECT: Many neurosurgeons routinely obtain computerized tomography (CT) scans to rule out hemorrhage in patients after stereotactic procedures. In the present prospective study, the authors investigated the rate of silent hemorrhage and delayed deterioration after stereotactic biopsy sampling and the role of postbiopsy CT scanning. METHODS: A subset of patients (the last 102 of approximately 800 patients) who underwent stereotactic brain biopsies at the Toronto Hospital prospectively underwent routine postoperative CT scanning within hours of the biopsy procedure. Their medical charts and CT scans were then reviewed. A postoperative CT scan was obtained in 102 patients (aged 17-87 years) who underwent stereotactic biopsy between June 1994 and September 1996. Sixty-one patients (59.8%) exhibited hemorrhages, mostly intracerebral (54.9%), on the immediate postoperative scan. Only six of these patients were clinically suspected to have suffered a hemorrhage based on immediate postoperative neurological deficit: in the remaining 55 (53.9%) of 102 patients, the hemorrhage was clinically silent and unsuspected. Among the clinically silent intracerebral hemorrhages, 22 measured less than 5 mm. 20 between 5 and 10 mm, five between 10 and 30 mm, and four between 30 and 40 mm. Of the 55 patients with clinically silent hemorrhages, only three demonstrated a delayed neurological deficit (one case of seizure and two cases of progressive loss of consciousness) and these all occurred within the first 2 postoperative days. Of the neurologically well patients in whom no hemorrhage was demonstrated on initial postoperative CT scan, none experienced delayed deterioration. CONCLUSIONS: Clinically silent hemorrhage after stereotactic biopsy is very common. However, the authors did not find that knowledge of its existence ultimately affected individual patient management or outcome. The authors, therefore, suggest that the most important role of postoperative CT scanning is to screen for those neurologically well patients with no hemorrhage. These patients could safely be discharged on the same day they underwent biopsy.

Adolescent↗
PubMed1998

Complete hydatidiform mole. Comparison of clinicopathologic features, current and past.

OBJECTIVE: To investigate whether changes have occurred in the pathologic and clinical features of complete molar gestation in recent years. STUDY DESIGN: Twenty-three contemporary complete hydatidiform moles (1994-1997) and 20 historical complete moles (1969-1975) were compared regarding clinical features (gestational age at evacuation, maternal age, preevacuation diagnosis and persistence) and pathologic findings (volume of tissue, presence of gross cisterns, maximal villous size, percent of cavitated villi, percent of villi exhibiting circumferential trophoblast hyperplasia, and presence of necrosis and primitive stromal features). RESULTS: Contemporary complete moles were evacuated at an earlier mean gestational age (8.5 vs. 17.0 weeks, P = .00008). Histologically, contemporary complete moles had less circumferential trophoblastic hyperplasia (39% vs. 75% of villi, P = .03), a smaller mean maximal villous diameter (5.7 vs. 8.2 mm, P = .001), more primitive villous stroma (70% vs. 10% of cases, P = .0003) and less global necrosis (22% vs. 54% of cases, P = .02). CONCLUSION: These striking morphologic differences indicate that pathologic findings in complete molar gestations have changed significantly over the past several decades due to the current practice of very early uterine evacuation. Contemporary complete moles are often characterized by subtle morphologic alterations that may result in their misclassification as partial moles or nonmolar spontaneous abortions. It is important for pathologists to recognize the distinctive histopathologic features of early complete hydatidiform mole.

Adult↗
PubMed1998

Reproductive outcome after methotrexate treatment of tubal pregnancies.

OBJECTIVE: To evaluate subsequent pregnancy outcomes in women who have been treated with methotrexate for tubal pregnancies. METHODS: Descriptive study of subsequent pregnancy outcomes in 170 women who were treated with methotrexate for tubal pregnancy at Brigham and Women's Hospital during 1989-1994. Patients who agreed to participate were administered a telephone interview. Fertility rates and outcomes were calculated for patients who tried to conceive after receiving methotrexate. RESULTS: One hundred four of the 170 women with tubal pregnancies identified during the study period returned their consent forms. The other 66 patients were either unable to be reached by phone, and/or their consent form was returned without a forwarding address. Ninety-four patients (90%) agreed to participate in the study. Eighty-two (87%) women tried to conceive after receiving methotrexate for their tubal pregnancies, and 57 (70%) were successful. Forty-six (81%) of the 57 women experienced intrauterine pregnancies, and 11 (19%) had recurrent tubal pregnancies. When the first subsequent postmethotrexate outcome was examined, there were 26 (46%) term births, 5 (9%) preterm births, 11 (19%) recurrent ectopics and 15 (26%) spontaneous abortions. Over the six-year study period, 42 (74%) women had at least one live birth. There were no congenital anomalies or stillbirths in the subsequent pregnancies. CONCLUSION: Pregnancy outcomes after methotrexate treatment for tubal pregnancy are comparable to reported experience with surgical therapy. Patients who are treated with methotrexate for tubal pregnancies can be assured that their methotrexate exposure should have no untoward effects on subsequent pregnancies.

Female↗
PubMed1998

Oral contraceptive use in relation to smoking.

BACKGROUND: Use of OC simultaneous with smoking in older women remains a concern for prescribing physicians, in light of current guidelines for OC use and evidence from recent studies about risks and benefits of different OC agents. It is useful to look at prevalence of OC use simultaneously with smoking after age of 35, as an indication of the effectiveness of these guidelines. METHODS: Survey of OC use in relation to smoking on a representative sample of 1138 urban women aged 40-54, from Geneva, Switzerland. History of exposure to both OC and smoking is analyzed up to the age of 40. RESULTS: Seventy-six percent of women had ever used OC, and 49% had ever smoked by age 40. Fifty-four percent of women reported OC exposure simultaneous to smoking at some time, and simultaneous exposure accounted for 48% of woman-years of use. But simultaneous use decreased with age, such that simultaneous users during age 36-40 accounted for 37% of OC users during that age period, and for only 13% of all ever OC users. Similarly, woman-years of OC use simultaneous with smoking fell after age 25, and woman-years during age 36-40 accounted for 36% of woman-years during that age period, such that only 5% of woman-years of OC use overall. CONCLUSIONS: OC use simultaneous with smoking after age 35 is not typical. Results suggest that a physician today may prescribe a type of OC that fits a young woman's current risk profile, confident of being able to change OC use or smoking by the time the woman enters an older risk profile. Prescribing OC to a young smoker does not generally lead to simultaneous exposure at a later age.

Adult↗
PubMed1997

Is there a genetic susceptibility locus for Parkinson's disease on chromosome 22q13?

The cytochrome P450 mono-oxygenase gene, CYP2D6 on chromosome 22q13 (ch22q13), has been inconsistently associated with Parkinson's disease. Associations with CYP2D6 have either been absent altogether or have involved more than one polymorphism, many of which have the same metabolic effect on gene expression. We examined the association between CYP2D6 polymorphisms and Parkinson's disease in a case-control study and included 10 polymorphic dinucleotide repeat markers linked to CYP2D6 to determine whether the association was present or due to linkage disequilibrium. There was no association between any polymorphism of CYP2D6 and Parkinson's disease, but two of 10 dinucleotide repeat markers linked to CYP2D6 were associated with the disease. These results provide evidence to suggest that there may be an unidentified locus for susceptibility to Parkinson's disease that is in linkage disequilibrium with dinucleotide repeat markers mapping near CYP2D6 on ch22q13.

Adult↗
PubMed1997

Mechanical bowel preparation for elective colorectal surgery. A prospective, randomized, surgeon-blinded trial comparing sodium phosphate and polyethylene glycol-based oral lavage solutions.

AIM: The aim of this study was to compare the cleansing ability, patient compliance, and safety of two oral solutions for elective colorectal surgery. METHODS: All eligible patients were prospectively randomized to receive either 4 l of standard polyethylene glycol (PEG) solution or 90 ml of sodium phosphate (NaP) as mechanical bowel preparation for colorectal surgery. A detailed questionnaire was used to assess patient compliance. In addition, the surgeons, blinded to the preparation, intraoperatively evaluated its quality. Postoperative septic complications were also assessed. The calcium serum level was monitored before and after bowel preparation. Statistical analysis was performed using the Wilcoxon's rank-sum test and Fisher's exact test. RESULTS: Two hundred patients, well matched for age, gender, and diagnosis, were prospectively randomized to receive either PEG or NaP solutions for elective colorectal surgery. All patients completed all phases of the trial. There was a significant decrease in serum calcium levels after administration of both NaP (mean, 9.3-8.8 mg/dl) and PEG (9.2-8.9 mg/dl), respectively (P < 0.0001), with no clinical sequelae. However, patient tolerance to NaP was superior to PEG: less trouble drinking the preparation (17 vs. 32 percent; P < 0.0002), less abdominal pain (12 vs. 22 percent; P = 0.004), less bloating (7 vs. 28 percent), and less fatigue (8 vs. 17 percent), respectively. Additionally, 65 percent of patients who received the NaP preparation stated they would repeat this preparation again compared with only 25 percent for the PEG group (P < 0.0001). Ninety-five percent of patients who received the NaP solution tolerated 100 percent of the solution compared with only 37 percent of the PEG group (P < 0.0001). For quality of cleansing, surgeons scored NaP as "excellent" or "good" in 87 compared with 76 percent after PEG (P = not significant). Rates of septic and anastomotic complications were 1 percent and 1 percent for NaP and 4 percent and 1 percent for PEG, respectively (P = not significant). CONCLUSION: Both oral solutions proved to be equally effective and safe. However, patient tolerance of the small volume of NaP demonstrated a clear advantage over the traditional PEG solution.

Colonic Diseases↗
PubMed1997

Liposome-mediated gene transfer to lung isografts.

OBJECTIVES: Our objective were to determine the feasibility, efficacy, and safety of in vivo and ex vivo liposome-mediated gene transfer to lung isografts. METHODS: Fischer rats were divided into three main groups: (1) Nontransplant setting: Liposome-chloramphenicol acetyl transferase cDNA was intravenously injected, and lungs were harvested at different time points: 2, 6, 12, and 24 hours; 2, 5, 8, and 21 days (n = 3). Chloramphenicol acetyl transferase activity was determined in lungs, hearts, livers, and kidneys. The distribution and type of transfected cells were evaluated by in situ hybridization. Lung toxicity was assessed by arterial oxygen tension, histology, and tumor necrosis factor-alpha levels. (2) In vivo graft transfection: Left lungs were transplanted 6 hours, 4 hours, and 15 minutes after intravenous injection and were assessed for chloramphenicol acetyl transferase activity and arterial oxygen tension on postoperative day 2. (3) Ex vivo graft transfection: Grafts were infused ex vivo with either 660 micrograms (n = 3) or 330 micrograms (n = 3) of DNA complexed to liposomes and stored at 10 degrees C for 4 hours. Chloramphenicol acetyl transferase activity was assessed 44 hours after transplantation. RESULTS: Transgene expression was detected in endothelial cells, macrophages, and interstitial cells. Chloramphenicol acetyl transferase activity was present as early as 2 hours, increased significantly between 6 hours and 8 days, and then decreased to minimal levels by 21 days. Chloramphenicol acetyl transferase activity was greatest in donor lungs and hearts and minimal in livers and kidneys. Arterial oxygen tension was normal in treated animals. Inflammation was minimal, and tumor necrosis factor-alpha levels increased only sevenfold in treated animals. CONCLUSION: In vivo and ex vivo liposome-mediated gene transfer to lung isografts allows significant transgene expression with minimal effects on graft function.

Animals↗
PubMed1997

Screening for neuroblastoma is ineffective in reducing the incidence of unfavourable advanced stage disease in older children.

Neuroblastoma exhibits many characteristics which would suggest that preclinical detection may improve outcome. The Quebec Neuroblastoma Screening Project was initiated to determine whether mass screening could reduce mortality in a large cohort of infants. All 476,603 children born in the province of Quebec during a 5-year period of time (1 May 1989 to 30 April 1994) were eligible for determinations of urinary catecholamine metabolites at 3 weeks and 6 months of age. Children with positive screening were referred to one of four paediatric cancer centres in Quebec for uniform evaluation and treatment. Standardised incidence ratios (SIRs) were calculated for neuroblastoma in Quebec and two comparable population-based controls during the same period of time using similar ascertainment procedures. Compliance with screening in Quebec was 91% at 3 weeks (n = 425,816) and 74% at 6 months (n = 349,706). Up to 31 July 1995 with a follow-up of the birth cohort of 15-75 months, 118 cases of neuroblastoma were diagnosed, 43 detected preclinically by screening, 20 detected clinically prior to screening at 3 weeks of age and 55 detected clinically after 3 weeks of age having normal screens (n = 52) or never screened (n = 3). Based on data from concurrent control populations, 54.5 cases of neuroblastoma would have been expected in Quebec during the study period for an SIR of 2.17 (95% CI 1.79-2.57, P < 0.0001). For the two control groups, the overall SIR was 1.00 (NS). SIRs for Quebec by age at diagnosis in yearly intervals show a marked increased incidence under 1 year of age (SIR = 2.85, 95% CI 2.26-3.50), with no reduction in incidence in subsequent years. We conclude that screening for neuroblastoma markedly increases the incidence in infants without decreasing the incidence of unfavourable advanced stage disease in older children. It is unlikely that screening for neuroblastoma in infants will reduce the mortality of this disease.

Canada↗
PubMed1997

Lhermitte-Duclos disease: literature review and novel treatment strategy.

BACKGROUND: Lhermitte-Duclos disease (LDD) is a rare pathologic entity involving the cerebellum. The fundamental nature of the entity and its pathogenesis remain unknown, and considerable debate has centered on whether it represents a neoplastic, malformative or hamartomatous lesion. The cell or cells of origin remain incompletely defined. Previous reports of cases in the English literature have dealt predominantly with the clinical and pathological aspects yet few address issues of treatment. METHODS: A case of Lhermitte-Duclos disease (LDD) in a 54-year-old female leading to local compressive symptoms and obstructive hydrocephalus is presented. A craniectomy, in addition to a C1 laminectomy followed by a decompressive duroplasty (using autologous fascia lata graft) was performed. RESULTS: The patient clinically improved and follow-up MRI 11 months post-operatively revealed improvement in hydrocephalus. CONCLUSION: The histological and immunohistochemical features of the lesion are described, emphasizing the role of an abnormal dysplastic granule cell layer. The evidence in favor of each of the major theories of pathogenesis, malformative and neoplastic is discussed. Based on these facts a form of surgical intervention involving decompressive duroplasty is proposed.

Cerebellar Diseases↗
PubMed1997

Effects of iodine-125 brachytherapy on the proliferative capacity and histopathological features of glioblastoma recurring after initial therapy.

OBJECTIVE: To determine the effect of initial therapy (surgery and external beam radiation) on the proliferative capacity of glioblastoma and whether adjunctive high focused doses of radiation therapy can further reduce the proliferative capacity of the tumor. This would provide a rationale for attempting to further control local tumor growth with the different forms of high-dose focused radiation available. METHODS: Patients with glioblastoma were initially treated within a randomized, controlled study with or without iodine-125 (125 I) brachytherapy after initial surgical resection and external beam radiation (50 Gy in 25 fractions). Specimens from 24 consecutive patients later reoperated for "recurrence" were used to determine the effects of 125 I brachytherapy on the histological features and proliferating cell nuclear antigen index of the tumor tissue. RESULTS: 125 I brachytherapy reduced histological features prognostic for tumor progression, i.e., cellularity, pleomorphism, vessel hyperplasia, and degree of mitosis (P < 0.05). The degree of mitosis (marker for the mitotic or "M" phase) and proliferating cell nuclear antigen index (market for the late G1 and S phase) provide complementary data on the cell kinetics of the tumor. Proliferating cell nuclear antigen immunostaining was lower in the 125 I brachytherapy group (34.6 +/- 8.2%, mean +/- standard error) compared with the control nonimplant group (68.2 +/- 3.5%). 125 I brachytherapy produced a dramatic reduction in mitotic figures (mean histological score = 0.0 +/- 0.0). CONCLUSION: Adjunctive treatment of glioblastoma with discrete high doses of radiation therapy delivered by 125 I brachytherapy allows further control of the proliferative capacity of the tumor.

Adolescent↗
PubMed1997

Effect of implant dose/volume and surgical resection on survival in a rat glioma brachytherapy model: implications for brain tumor therapy.

OBJECTIVE: This study sought to investigate the effects of implant dose/volume and surgical resection on survival in a rat glioma brachytherapy model. Two doses were investigated to determine a suitable therapeutic range. METHODS: We performed two experiments. Three treatment groups and one control group of male F-344 rats bearing 9L brain tumors 12 days after tumor inoculation were used in the first experiment. Day 12 tumors were an average of 4 to 6 mm in diameter. Animals treated with brachytherapy received a tumor dose of 80 Gy delivered to a 5.5-mm-radius volume. Total macroscopic tumor removal was achieved by microsurgical techniques. A subsequent experiment compared the survival of tumor-burdened rats treated with an implant dose of 60 Gy delivered to a 5.5-mm-radius volume with a control group. RESULTS: Surgery alone produced an increased life span of 28.6% over control animals treated with sham surgery and dummy seed implants, a statistically significant increase in survival (P = 0.0023, log-rank test). Brachytherapy alone produced the most significant increase in survival over control animals (P = 0.0001, log-rank test; median survival not attained with an implant dose of 80 Gy delivered to a 5.5-mm-radius volume; and P = 0.0001, increased life span 121% with an implant dose of 60 Gy delivered to a 5.5-mm-radius volume). This was not improved by the addition of surgical tumor removal. CONCLUSION: We have demonstrated a relationship between implant dose/volume and survival of tumor-burdened rats in this model that is not improved by the addition of tumor removal. Implications for brain tumor brachytherapy are discussed.

Animals↗
PubMed1997

Multilevel anterior cervical corpectomy and fibular allograft fusion for cervical myelopathy.

This study was conducted to determine the safety and efficacy of multilevel anterior cervical corpectomy and stabilization using fibular allograft in patients with cervical myelopathy. Thirty-six patients underwent this procedure for cervical myelopathy caused by spondylosis (20 patients), ossified posterior longitudinal ligament (four patients), trauma (one patient), or a combination of lesions (11 patients). The mean age (+/- standard deviation) of the patients was 58 +/- 10 years and 30 of the patients were men. The mean duration of symptoms before surgery was 30 +/- 6 months and 11 patients had undergone previous surgery. Prior to surgery, the mean Nurick grade of the myelopathy was 3.1 +/- 1.4. Seventeen patients also had cervicobrachial pain. Four vertebrae were removed in six patients, three in 19, and two in 11 patients. Instrumentation was used in 15 cases. The operative mortality rate was 3% (one patient) and two patients died 2 months postoperatively. Postoperative complications included early graft displacement requiring reoperation (three patients), transient dysphagia (two patients), cerebrospinal fluid leak treated by lumbar drainage (three patients), myocardial infarction (two patients), and late graft fracture (one patient). One patient developed transient worsening of myelopathy and three developed new, temporary radiculopathies. All patients achieved stable bone union and the mean Nurick grade at an average of 31 +/- 20 months (range 0-79 months) postoperatively was 2.4 +/- 1.6 (p < 0.05, t-test). Cervicobrachial pain improved in 10 (59%) of the 17 patients who had preoperative pain and myelopathy improved at least one grade in 17 patients (47%; p < 0.05). Twenty-six surviving patients (72%) were followed for more than 24 months and stable, osseous union occurred in 97%. These results show that extensive, multilevel anterior decompression and stabilization using fibular allograft can be achieved with a perioperative mortality and major morbidity rate of 22% and with significant improvement in pain and myelopathy.

Aged↗
PubMed1997

Clinical and epizootiological study of a leptospirosis outbreak due to Leptospira canicola in a feedlot.

This report describes the epizootiology, clinical presentation, diagnosis and treatment of an outbreak of leptospirosis caused by Leptospira canicola in feedlot calves. The infection appeared to be of high morbidity with a cumulative clinical incidence of 15.6%, cumulative subclinical incidence of 39% and high mortality (8.3%). Clinical disease was diagnosed in 4-8-month-old calves, while subclinical infection occurred in 9-12-month-old calves. Subclinical infection was based on serological evidence only. The zoonotic aspects of the infection are emphasised.

Animal Feed↗
PubMed1997

Pulmonary hemodynamics modify the rat pulmonary artery response to injury. A neointimal model of pulmonary hypertension.

Hemodynamic factors have profound influences on blood vessels. To test the hypothesis that hemodynamic conditions modify the pattern of remodeling in response to injury, monocrotaline (MCT) injury in Sprague-Dawley rats was followed 1 week later by left pneumonectomy to increase blood flow to the right lung. Right pulmonary artery remodeling in these MCT plus pneumonectomy animals was compared with animals receiving MCT or pneumonectomy alone. Neointimal changes developed in more than 90% of all right lung intra-acinar vessels 5 weeks after MCT injury (4 weeks after pneumonectomy). Neointimal lesions did not develop in untreated animals or in animals receiving MCT or pneumonectomy only. Animals with a neointimal pattern of remodeling developed severe right ventricular hypertrophy (RVH) whereas animals with a medial hypertrophy pattern of remodeling (MCT only) developed moderate RVH compared with control animals. Neointimal lesions and RVH were similar whether injury preceded pneumonectomy or vice versa. To exclude the possibility that neointimal lesions resulted from injury plus post-pneumonectomy compensatory lung growth, rather than injury plus increased flow, a left subclavian-pulmonary artery anastomosis was substituted for pneumonectomy. Neointimal lesions and severe RVH developed in these animals but were not seen in animals receiving either MCT or anastomosis only. These studies demonstrate an important role for hemodynamics in determining the pattern of pulmonary vascular remodeling after injury.

Actins↗
PubMed1996

Receptor-mediated calcium signalling in glial cells from mouse corpus callosum slices.

We addressed the question of whether glial cells in intact white matter tracts express neurotransmitter receptors and we used Ca+2 signalling as a probe to detect the receptor activation. Corpus callosum slices from postnatal mice were bulk-loaded with the Ca+2-sensitive fluorescent dye fluo-3, and confocal microscopy was used to measure Ca+2 transients in response to neuroligands. Glial cell bodies were intensely dye-loaded and could be discriminated from the diffuse fluorescence of axons. Subpopulations of glial cells from slices obtained at postnatal days 3 to 7 responded with Ca+2 signals to ATP, glutamate, histamine, GABA, norepinephrine, serotonin, angiotensin II, bradykinin, and substance P. These subpopulations showed a distinct overlap; cells which were responsive to substance P always showed Ca+2 signalling in response to histamine, ATP, GABA and high K+ (membrane depolarization). GABA-responsive cells almost always showed a [Ca+2]i increase after membrane depolarization. In brain slices from postnatal day 11 to 18 animals, the Ca+2 responses were evident for glutamate, ATP, and norepinephrine, while GABA, substance P, serotonin, histamine, or angiotensin II rarely elicited a response. This study demonstrates that white matter glial cells in slices exhibit a large repertoire of neurotransmitter responses linked to Ca+2 signalling and that these receptor systems are differentially distributed on sub-populations of glial cells.

Animals↗