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Biomedical subjects

M Bernstein

Publications and source records attributed to M Bernstein.

At least 127 records · Page 7Linked to original sources
PubMed1995

Low-grade gliomas.

Supratentorial low-grade gliomas comprise a group of primary central nervous system neoplasms with characteristics of neuroglial cells (i.e., astrocytes and oligodendrocytes) and relatively low anaplastic potential, although through time they tend to behave more aggressively. Immediate surgical intervention and subsequent radiation therapy are advocated by some workers; at present, however, it remains unclear whether early intervention prolongs survival or changes the natural history of the disease, especially in those patients who present with a seizure and a normal interictal examination.

Adult↗
PubMed1994

Brachytherapy for recurrent malignant astrocytoma.

PURPOSE: To assess the efficacy of interstitial brachytherapy in the treatment of patients with recurrent malignant astrocytoma. METHODS AND MATERIALS: Forty-six patients with recurrent malignant astrocytoma were treated with stereotactic high-activity temporary iodine-125 implants between September, 1986 and October, 1992. All patients had been initially treated for malignant astrocytoma (44) or low-grade astrocytoma (2) with surgery and external fractionated radiation. The median time between initial diagnosis and recurrence treated with brachytherapy was 12.5 months. Twenty-five patients received chemotherapy prior to brachytherapy. RESULTS: All but four patients have died; median survival time following brachytherapy is 46 weeks. Twelve patients underwent reoperation for radiation necrosis at a median interval of 6.5 months after treatment (26%). Five patients incurred complications directly due to brachytherapy (11%). Forty-four patients are evaluable regarding pattern of failure following brachytherapy. Six of these 44 patients (13.6%) recurred at a distance from the treatment volume (4 in brain and 2 in spinal subarachnoid space). CONCLUSION: Brachytherapy confers modest but meaningful prolongation of survival in selected patients with recurrent malignant astrocytoma, but complications are significant, reoperation frequently required, and recurrence outside the treatment volume common.

Adolescent↗
PubMed1994

Randomised trial of intravenous immunoglobulin G, intravenous anti-D, and oral prednisone in childhood acute immune thrombocytopenic purpura.

The most serious complication of childhood acute immune thrombocytopenic purpura (ITP), intracranial haemorrhage, occurs in about 1% of children with platelet counts below 20 x 10(9)/L. We conducted a randomised study to explore three treatment options in this high-risk group. 146 children (> 6 months and < 18 years old) with typical acute ITP and platelet counts of 20 x 10(9)/L or lower were randomised to receive high-dose intravenous immunoglobulin G (IVIgG) 1 g/kg on 2 consecutive days (n = 34), 0.8 g/kg once (n = 35), intravenous anti-D 25 micrograms/kg on 2 consecutive days (n = 38), or oral prednisone 4 mg/kg per day with tapering and discontinuation of prednisone by day 21 (n = 39). The rate of response as reflected by the number of days with platelet counts at 20 x 10(9)/L or lower and the time taken to achieve a platelet count 50 x 10(9)/L or more was significantly faster for both IVIgG groups than for the anti-D group (p < 0.05); the difference between prednisone and IVIgG was significant (p < 0.05) only for the IVIgG 0.8 g/kg group, and responses to the two IgG groups were similar. These differences in response rates were reflected in the percentages of children with platelet counts of 20 x 10(9)/L or lower at 72 hours following the start of treatment: 3% (IVIgG 0.8 g/kg x 1), 6% (IVIgG 1 g/kg x 2), 18% (anti-D), and 21% (oral prednisone 4 mg/kg/day). Treatment-associated toxicities included a fall in haemoglobin with anti-D (to less than 100 g/L in 24% of cases); weight gain with oral prednisone; and fever, nausea, vomiting, and headache with IVIgG. On the basis of these results, intravenous anti-D cannot be recommended as initial therapy for children with acute ITP and platelet counts of 20 x 10(9)/L or lower. A single dose of 0.8 g/kg IVIgG offers the fastest recovery for the least treatment; additional IgG or oral prednisone can be reserved for the one-third of children who continue to have platelet counts of 20 x 10(9)/L or less at 48-72 hours after the start of treatment.

Adolescent↗
PubMed1994

Venous thromboembolic complications (VTE) in children: first analyses of the Canadian Registry of VTE.

Deep vein thrombosis (DVT) and pulmonary embolism (PE) occur in pediatric patients; however, the incidence, associated morbidity, and mortality are unknown. A Canadian registry of DVT and PE in children (ages 1 month to 18 years) was established July 1, 1990 in 15 tertiary-care pediatric centers. One-hundred thirty-seven patients were identified prospectively and are the subject of this report. The incidence of DVT/PE was 5.3/10,000 hospital admissions or 0.07/10,000 children in Canada. Infants under 1 year old and teenagers predominated with equal numbers of both sexes. DVT were located in the upper (n = 50) and lower (n = 79) venous system, or as PE alone (n = 8). Central venous lines (CVLs) were present in approximately 33% of children with DVT (n = 45). Associated conditions were present in 96% of children and 90% of children had two or more associated conditions for DVT. DVT was diagnosed by venography (n = 83), duplex ultrasound (n = 37), and other combinations (n = 17). Twenty-two of the 31 ventilation/perfusion scans performed were interpreted as high-probability scans for PE. Therapy consisted of heparin (n = 115), thrombolysis (n = 15), surgical removal of a CVL or thrombus (n = 22), and oral anticoagulant therapy (n = 103). Significant bleeding complications did not occur. However, three (2.2%) children died as a direct consequence of their thromboembolic disease; DVT reoccurred in 23 children and postphlebitic syndrome (PPS) occurred in 26. In conclusion, DVTs occur in a significant number of hospitalized children with a mortality of 2.2%. Complications are not hemorrhagic, but thrombotic, and characterized by PE, recurrent disease, and PPS. In contrast to adults, the upper venous system is frequently affected because of the use of CVLs. The frequency of DVT/PE justifies controlled trials of primary prophylaxis in high-risk groups, and therapeutic trials to determine optimal treatment.

Administration, Oral↗
PubMed1994

Chromosomal localization of genes required for the terminal steps of oxidative metabolism: alpha and gamma subunits of ATP synthase and the phosphate carrier.

The terminal steps of oxidative phosphorylation include transport of phosphate and ADP into the mitochondrial matrix, synthesis of ATP in the matrix, and transport of the product ATP into the cytosol where it can be utilized to perform cellular work. Three nuclear genome encoded membrane proteins, namely, the phosphate carrier (PHC), the adenine nucleotide carrier (ANT), and the ATP synthase complex, consisting of at least 13 individual subunits, catalyze these reactions. The locations of the alpha and gamma subunits of the mitochondrial ATP synthase complex and the mitochondrial phosphate carrier, PHC, on human chromosomes were determined using cloned rat liver cDNA as probes. Human homologues of the alpha subunit are on chromosomes 9 and 18, the gamma subunit are on chromosomes 10 and 14, and the PHC was localized to chromosome 12.

Animals↗
PubMed1994

[Nutritional balance of the diet of the adult residents of Geneva].

Diet of the Swiss population has probably changed over the last 10 years, but these changes have not been recorded yet by nutritional studies. In the present study, 3 registered dieticians interviewed over the telephone 626 adults, resident of Canton Geneva, using a 24 hour recall. Interviews were performed during the 7 days of the week. Participants were randomly selected according to their age, sex and nationality. Participation was 80%. The following caloric (C) and nutritional intakes in proteins (P), lipids (L), carbohydrates (CH) and alcohol (A) were recorded: In non Swiss men: C = 2464 kcal/j., P = 16.2%, L = 32.4%, CH = 44.4%, A = 7.0%; in Swiss men: C = 2752 kcal/j., P = 15.3%, L = 34.0%, CH = 43.5%, A = 7.1%; in non Swiss women: C = 1897 kcal/j., P = 16.4%, L = 35.1%, CH = 46.5%, A = 2.4%; in Swiss women: C = 1865 kcal/j., P = 15.0%, L = 35.3%, CH = 46.0%, A = 3.2%. Total caloric intake and iron intake decreased with age. Older women ate less calcium than younger. In summary, the most important determinants of diet are age and sex. Proportion of lipids is relatively low in both men and women. Small differences related to nationality were observed in men.

Adult↗
PubMed1994

[Development and validation of a semi-quantitative food questionnaire based on a population survey].

An auto-administered, semi-quantitative food frequency questionnaire was developed to assess evolution of dietary habits in the Geneva population. For this purpose 626 adults, aged 35 years or more and residents of Canton Geneva, were interviewed using a 24 hour recall technique. The questionnaire comprises the 80 food items or homogeneous food groups contributing to more than 90% of the intake in calories, proteins, lipids, carbohydrates, alcohol, cholesterol, calcium, vitamin D and retinol, and to more than 85% of dietary fibers, carotene and iron. To complete the food frequency questionnaire, participants indicate for each of the 80 food items or groups their frequency of consumption and whether their usual portion is equivalent to a reference portion listed in the questionnaire (median portion in the sample), smaller (first quartile of the portion distribution in the sample) or larger (third quartile of the portion distribution in the sample). The questionnaire can be filled in about 20 minutes. To test the new questionnaire we submitted it to a sample of 27 men and 29 women randomly selected from the 626 subjects who participated to the original survey. Mean intakes obtained using the food frequency questionnaire agree well with those obtained using the 24 hour recall for all subgroups defined by age, sex or nationality. The food frequency questionnaire tends to slightly underestimate the absolute intakes of alcohol, fibers and calcium since it is based on a subsample of all food items consumed according to the 24 hour recall interviews. These results suggest that the semi-quantitative food frequency questionnaire is a good alternative to 24 hour recalls to assess mean nutrient intakes in the adult population of Canton Geneva.

Adult↗
PubMed1994

Norfloxacin nicotinate in the treatment of Pseudomonas aeruginosa infection in the genital tract of a bull.

Consecutively collected semen samples from a breeding bull were found to be contaminated with Pseudomonas aeruginosa. Palpation through the bull's scrotum revealed inflammatory changes suggestive of chronic orchiepididymitis in one testicle. For 10 months, all the bull's 13 ejaculates were discarded because the post-thaw viability was < 20%. Norfloxacin nicotinate was injected intramuscularly into the bull at 5 mg/kg daily for 7 days. Serum and semen samples were collected at 24-h intervals during the course of treatment and afterwards and were assayed for NFN concentrations. Drug concentrations in the semen, by microbiological assay, during treatment and up to 120 h after the last treatment ranged from 2.6 to 5.1 micrograms/ml, 14.2 to 43.2 times the corresponding serum drug levels. P. aeruginosa was not isolated from the semen 4 or 15 days after the last injection but was re-isolated after 32 and 64 days. A second similar course of NFN was administered and P. aeruginosa was not isolated from semen samples collected on four occasions, 6, 22, 44 and 94 days after the last treatment.

Animals↗
PubMed1994

Kinesin-like proteins in the flagella of Chlamydomonas.

The flagella of the biflagellate unicellular alga Chlamydomonas have long been known to contain the microtubule-dependent motor protein dynein, but recent findings indicate they also contain multiple members of the kinesin superfamily. Two of these kinesin-like proteins are restricted to a single central-pair microtubule, raising the question of how proteins are targeted to specific microtubules within the flagellum. The kinesin-like proteins on the central-pair microtubules may cause the central-pair apparatus to rotate or twist during flagellar beating. Other kinesins within the flagellum may participate in movements associated with the flagellar membrane.

Journal Article↗
PubMed1994

Complications of first craniotomy for intra-axial brain tumour.

Complications were examined in a single surgeon's series of 207 consecutive adult patients undergoing first craniotomy for intra-axial brain tumour. The study group consisted of 114 gliomas, 74 metastatic tumours and 19 miscellaneous lesions. There were 25 infratentorial tumours and 182 supratentorial tumours (39 deep and 143 superficial). The total number of patients sustaining complications was 52 for an overall complication rate of 25.1%; the rate was higher for infratentorial tumours (44.0%) than supratentorial tumours (22.8%) regardless of histology (p = 0.012). There were 5 deaths for a mortality rate of 2.4%. Forty-seven patients incurred operative morbidity (22.7%); 7 out of the 47 had multiple complications. Sixteen patients sustained transient worsening due to edema (7.7%) and 6 patients sustained permanent neurological deficit (2.9%). Medical complications were suffered by 17 patients (8.2%). Major complications which significantly altered the quality and/or quantity of survival were suffered by 9 patients overall (4.3%).

Adolescent↗
PubMed1994

A new kinesin-like protein (Klp1) localized to a single microtubule of the Chlamydomonas flagellum.

The kinesin superfamily of mechanochemical proteins has been implicated in a wide variety of cellular processes. We have begun studies of kinesins in the unicellular biflagellate alga, Chlamydomonas reinhardtii. A full-length cDNA, KLP1, has been cloned and sequenced, and found to encode a new member of the kinesin superfamily. An antibody was raised against the nonconserved tail region of the Klp1 protein, and it was used to probe for Klp1 in extracts of isolated flagella and in situ. Immunofluorescence of whole cells indicated that Klp1 was present in both the flagella and cell bodies. In wild-type flagella, Klp1 was found tightly to the axoneme; immunogold labeling of wild-type axonemal whole mounts showed that Klp1 was restricted to one of the two central pair microtubules at the core of the axoneme. Klp1 was absent from the flagella of mutants lacking the central pair microtubules, but was present in mutant flagella from pf16 cells, which contain an unstable C1 microtubule, indicating that Klp1 was bound to the C2 central pair microtubule. Localization of Klp1 to the C2 microtubule was confirmed by immunogold labeling of negatively stained and thin-sectioned axonemes. These findings suggest that Klp1 may play a role in rotation or twisting of the central pair microtubules.

Amino Acid Sequence↗
PubMed1994

Differential effects of Sex-lethal mutations on dosage compensation early in Drosophila development.

In response to the primary sex determination signal, X chromosome dose, the Sex-lethal gene controls all aspects of somatic sex determination and differentiation, including X chromosome dosage compensation. Two complementary classes of mutations have been identified that differentially affect Sxl somatic functions: (1) those impairing the "early" function used to set developmental pathway choice in response to the sex determination signal and (2) those impairing "late" functions involved in maintaining the pathway choice independent of the initiating signal and/or in directing differentiation. This "early vs. late" distinction correlates with a switch in promoter utilization from SxlPe to SxlPm at the blastoderm stage and a corresponding switch from transcriptional to RNA splicing control. Here we characterize five partial-loss-of-function Sxl alleles to explore a distinction between "early vs. late" functioning of Sxl in dosage compensation. Assaying for dosage compensation during the blastoderm stage, we find that the earliest phase of the dosage compensation process is controlled by products of the early Sxl promoter, SxlPe. Hence, in addition to triggering the sexual pathway decision of cells, products derived from SxlPe also control early dosage compensation, the first manifestation of sexually dimorphic differentiation. The effects of mutant Sxl alleles on early dosage compensation are consistent with their previous categorization as early vs. late defective with respect to their effects on pathway initiation. Results reported here suggest that the dosage compensation regulatory genes currently known to function downstream of Sxl, genes known as the "male-specific lethals," do not control all aspects of dosage compensation either at the blastoderm stage or later in development. In the course of this study, we also discovered that the canonical early defective allele, Sxlf9, which is impaired in its ability to establish the female developmental pathway commitment, is likely to be defective in the stability and/or functioning of products derived from SxlPe, rather than in the ability of SxlPe to respond to the chromosomal sex determination signal.

Alleles↗
PubMed1994

Tuberculous mastitis.

We present a case of tuberculous mastitis. The patient's only other focus of tuberculosis, besides the clinical infection in the right breast, was a simple calcified primary complex in the right lung. Our review of records from the past 27 years yielded no other case of proven tuberculous mastitis in our hospital, which treats an annual average of 433 patients with breast diseases.

Female↗
PubMed1994

Non-fibrous dust load and smoking in dental technicians: a study using bronchoalveolar lavage.

A study was conducted with transmission electron microscopy to find whether bronchoalveolar lavage could be used to identify subjects with occupational exposure to mineral particles. Non-fibrous mineral particles in bronchoalveolar lavage (BAL) fluid from 46 dental technicians and 41 white collar controls with lung diseases but free from occupational exposure to dusts were analysed. The total particle concentration in BAL fluid was significantly higher in dental technicians than in controls (12.18 x 10(5) particles/ml of BAL fluid, v 2.03 x 10(5) particles/ml, p < 0.001). Dental technicians had significantly more crystalline silica, aluminium, and alloys containing nickel and chromium. There was a non-significant twofold increase of total particle concentration in the lungs of dental technicians who were smokers compared with non-smokers. The results strongly support the use of BAL fluid analysis to assess dust accumulation in workers in heavily exposed occupations such as dental technicians. This is a valid method to evaluate occupational exposure to non-fibrous mineral particles, and may be useful to determine the occupational aetiology of some respiratory diseases.

Bronchoalveolar Lavage Fluid↗
PubMed1994

Biopersistence of nonfibrous mineral particles in the respiratory tracts of subjects following occupational exposure.

Transmission electron microscopy analysis (TEMA) was used to analyze the bronchoalveolar lavage fluid (BALF) of 262 subjects occupationally exposed (OE) to nonfibrous mineral particles (NFMP) and 42 controls not occupationally exposed to mineral dusts. OE subjects were divided into three groups according to the lapse of time since last exposure: < or = 1 year and < 10 years (E2), > or = 10 years (E3). The total BALF mineral particle concentration was significantly higher in OE patients than in controls and was closely related to the time lapse since last exposure to NFMP (median values for OE, 7.7 x 10(5) particles/ml; E1, 9 x 10(5) particles/ml; E2, 5 x 10(5) particles/ml; E3, 4.3 x 10(5) particles/ml; controls, 2 x 10(5) particles/ml). No statistical difference was observed for age and smoking habits between OE and control subjects. Concentrations of crystalline silica and metals (exogenous iron, aluminum, metallic alloys and other metals) were significantly higher in OE subjects than in controls, and even though these mineral concentrations decreased with increasing time since last occupational exposure, they still remained higher in the E3 group than in controls. Crystalline silica and metals were thus identified as biopersistent NFMP in the human lung using BALF ATEM method. This method is a useful tool in assessing occupational exposure to NFMP, even when a long period has elapsed since last exposure, and may be used in studying etiology of some respiratory diseases.

Adult↗