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Biomedical subjects

J Berkowitz

Publications and source records attributed to J Berkowitz.

46 records · Page 3Linked to original sources
PubMed1988

Natural killer (NK) cells in chronic progressive multiple sclerosis patients treated with lymphoblastoid interferon.

Natural killer (NK) cell functional activity, as defined by the lysis of 51Cr-labelled K-562 cells, and number, defined phenotypically by anti-Leu-11, are significantly decreased in chronic progressive multiple sclerosis (MS) when compared to normal controls. When age- and sex-matched populations are compared, NK cell functional activity is again significantly reduced in MS compared to controls but not when compared to a control group of other medical disease (OMD). The MS group could be differentiated from the OMD group, however, when results of NK cell functional activity are combined with NK cell phenotype. With the administration of lymphoblastoid interferon daily for 6 months, NK cell activity increased significantly at 48 h and at 1 week. By 1 month, activity decreased to a level slightly above placebo treatment values. The results likely reflect interferon's enhancement of mature NK cell activity combined with a variable effect on recruitment of pre-NK cells.

Adult↗
PubMed1980

Molar uprighting with T-loop springs.

Uprighting of molars is indicated as an adjunct to restorative and periodontal procedures. Limiting conditions exist in which previously reported helical and box-loop springs cannot be used effectively. In those instances, segmental arch wires with T-loops upright the molars efficiently while maintaining control in three planes of space. Furthermore, these loop designs permit immediate engagement of these appliances. Clinical experiences with these springs by students in the professional and graduate dental clinics at the University of Kentucky College of Dentistry lead to the conclusion that: segmental uprighting arch wires with T-loops are easy to fabricate and use; T-looped uprighting springs can be engaged immediately and used efficiently in instances in which helical spring or box-loop uprighting appliances are contraindicated; T-looped uprighting springs offer excellent controlled movements of teeth in three planes of space; acceptance by the patient is favorable; and treatment time, depending on the amount of tooth movement required, is rapid and varies between 8 to 16 weeks.

Humans↗
PubMed1977

A vertical cephalometric analysis of the human craniofacial complex.

A vertical analysis involving ten linear measurements was developed to localize skeletal and dentoalveolar dysplasias. The measurements are of biologic relevance, reflecting the amount of growth harmony or disharmony to the examination and record-taking time. The vertical dimensional analysis uses the age- and sex-related University of Michigan mean values for comparative data for each measurement. Ratios were computed for a five-unit proportional analysis. Both analyses were applied to assess the vertical problems of three female patients. The analyses detected specific areas of dysplasia for each patient.

Adolescent↗
PubMed1975

Pre- and postnatal toxicity induced in guinea pigs by N-nitrosomethylurea.

Oral administration of N-nitrosomethylurea at maximally tolerated doses to guinea pigs on alternate days from days 34-58 of pregnancy induced prenatal toxicity, as evidenced by a high frequency of stillbirths and intrauterine growth retardation, and postnatal toxicity, as evidenced by stunting and progressive mortality. Similar administration of N-nitrosomethylurethane at maximally tolerated doses did not induce such toxic effects.

Abnormalities, Drug-Induced↗
PubMed1969

Salmonella in wastes produced at commercial poultry farms.

Composite samples of freshly voided excreta from 91 poultry houses were tested qualitatively for Salmonella; 26 (29%) were positive. The houses were located on 36 farms, 18 of which (50%) yielded one or more positive samples. In a separate, quantitative study, Salmonella densities ranged from less than 1 to over 34,000 per g of excreta (dry weight). High densities were noted in waste from cage houses, but not in waste from floor houses (litter or wire floors). Salmonella-shedding chickens were located in only one small area of the row of cages examined in detail. A total of 15 Salmonella serotypes were identified during the study.

Agriculture↗
PubMedDate not supplied

Configuration of interdomain linkers in pyruvate dehydrogenase complex of Escherichia coli as determined by cryoelectron microscopy.

The dihydrolipoyl transacetylase (E2p) component of the pyruvate dehydrogenase complex (PDC) of Escherichia coli is a multidomain polypeptide comprising a catalytic domain, a domain that binds dihydrolipoyl dehydrogenase (E3-binding domain), and three domains containing lipoic acid (lipoyl domains). In PDC 24 subunits of E2p associate by means of interactions involving the catalytic domains to form the structural core of PDC. From cryoelectron microscopy and computer image analysis of frozen-hydrated isolated E2p cores it appears that the lipoyl domains are located peripherally about the core complex and do not assume fixed positions. To further test this interpretation the visibility of the lipoyl domains in electron micrographs was enhanced by specifically biotinylating the lipoic acids and labeling them with streptavidin. In agreement with the studies of native, unlabeled E2p cores, cryoelectron microscopy of the streptavidin-labeled E2p cores showed that the lipoic acid moieties are capable of extending approximately 13 nm from the surface of the core. Localization of the E3-binding domains was accomplished by cryoelectron microscopy of E2p-E3 subcomplexes prepared by reconstitution in vitro. Frequently an apparent gap of several nanometers separated the bound E3 from the surface of the core. The third component of PDC, pyruvate dehydrogenase (E1p), appeared to bind to the E2p core in a manner similar to that observed for E3. These results support a structural model of the E2p core in which the catalytic, E3-binding, and three lipoyl domains are interconnected by linker sequences that assume extended and flexible conformations.

Bacterial Proteins↗
PubMedDate not supplied

Management of acute asthma in Canada: an assessment of emergency physician behaviour.

The study objective was to assess Canadian emergency physicians for their management preferences and their compliance with recently developed guidelines for treatment of acute asthma in adults. The design was a cross-sectional survey sent to members of the Canadian Association of Emergency Physicians (CAEP) and to the emergency department (ED) directors of all Canadian hospitals with more than 25 beds in November 1992. ED directors who had not responded were sent a second survey in January 1993. The response rates for the survey were 60.1% (362/602) for ED directors and 53.4% (302/586) for CAEP members. Respondents were more likely to be from larger hospitals and to have completed some training beyond general practice level (CCFP, CCFP-EM, ABEM, FRCPC). There were wide variations among respondents in the use of objective measurements of asthma severity (forced expiratory volume in 1 s [FEV1] and peak expiratory flow rates [PEFR]), dosing of bronchodilators, and utilization of systemic corticosteroids. Forty-six percent of respondents used the FEV1 "occasionally" (22.3%) or "never" (23.8%), and 26.7% used PEFR "occasionally" (15.8%) or "never" (10.9%) in asthma management. Ninety-seven percent used nebulized beta agonist "always" (71.3%) or "often" (25.6%), but only 48.5% used the metered dose inhaler (MDI) "always" (11%) or "often" (37.5%). More than a quarter of respondents (27.2%) used doses of beta agonists that were less than those recommended (> every 30-60 min). Oral corticosteroids were prescribed at discharge only "occasionally" (51.1%), "seldom" (18.9%), or "never" (6.5%) in 76.6% of physicians. Physicians with more training were more likely to assess and treat patients according to current asthma treatment guidelines. The survey shows that many Canadian emergency physicians did not follow published recommendations for the care of patients with acute asthma. This finding was especially so with regard to objective evaluation of airflow, aggressive use of beta-agonists, the use of corticosteroids, and in making appropriate arrangements for patient discharge and follow-up.

Acute Disease↗
PubMedDate not supplied

Tooth-surface progression and reversal changes in fluoridated and no-longer-fluoridated communities over a 3-year period.

OBJECTIVE: To compare permanent tooth surface-specific progression/reversal changes between fluoridation-ended (F-E) and still-fluoridated (S-F) communities in British Columbia, Canada, over a 3-year period. METHODS: D1D2MFS examinations were contrasted for 2,964 schoolchildren in 1993/94 (grades 2, 3, 8 and 9) and 1996/97 (grades 5, 6, 11 and 12). Generalized Estimating Equation (GEE) models explored the relation between progression/reversal changes and fluoridation status, age, gender, socioeconomic status, and dietary/fluoride histories. RESULTS: Within a scenario of low levels of caries overall, few children had multiple surfaces progressing. At least one smooth surface progressed in 31.4% of subjects; at least one pit-and-fissure (PF) surface progressed in 43.1% of subjects. At least one smooth surface reverted in 89% of subjects who had reversible stages; at least one PF surface reverted in 23.8% of subjects who had reversible stages. GEE (smooth) indicated that odds ratios of progression were twice as large in the F-E site compared to the S-F site, and slightly increased in older participants and in participants exposed to more fluoride technologies. GEE (PF) also indicated that progression was slightly more common in the F-E site; more frequent snacking and lower parental educational attainment had modest associations with increased progression in PF surfaces. For the two types of surfaces, GEE models demonstrated that unerupted surfaces were less likely to progress than sound surfaces. No associations were found between reversals and independent variables. CONCLUSION: Progressions were found to be weakly linked to socio-demographic factors; baseline surface statuses were better predictors of progression. Using the current definitions for disease transitions, F-E communities had more frequent progressions than a S-F community.

Adolescent↗