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Biomedical subjects

S Gabriel

Publications and source records attributed to S Gabriel.

At least 91 records · Page 5Linked to original sources
PubMed1990

Epidemiology of immunoglobulin E levels in a defined population.

Age-adjusted geometric mean IgE levels in 621 older subjects were higher in men (26.3 kU/L) than in women (19.1 kU/L), and decreased with age. The higher levels in men were largely a result of a strong positive association with cigarette smoking. Among allergic conditions, a personal history of asthma was associated with the highest IgE levels. In multiple linear regression models in men, cigarette smoking was the single strongest correlate of IgE levels, while a personal history of allergy was the strongest correlate in women. Our results suggest important nonallergic as well as allergic determinants of IgE levels in populations.

Adult↗
PubMed1990

Treatment of rheumatoid arthritis with higher dose intravenous methotrexate.

A pilot study evaluated intravenous methotrexate (MTX) (initial dose 40 mg/m2; final dose, 26 mg/m2), weekly for 12 weeks in 10 patients with rheumatoid arthritis who failed oral MTX. Statistically significant differences were noted for all the response variables examined: joint count (p = 0.0017), morning stiffness (p = 0.014), global assessment (patient, p = 0.0032, physician, p = 0.029), Arthritis Impact Measurement Scale (p = 0.0004), erythrocyte sedimentation rate (p = 0.012), grip strength (right p = 0.044, left p = 0.011). All 7 patients who completed the 12-week treatment period fulfilled the predetermined criteria for response. Intravenous MTX at these doses has potential efficacy in this patient group.

Adult↗
PubMed1989

Peripheral arterial disease in large vessels is epidemiologically distinct from small vessel disease. An analysis of risk factors.

The authors used noninvasive techniques, including flow velocity by Doppler ultrasound, to accurately assess and distinguish between large and small vessel peripheral arterial disease in a population study in southern California, 1978-1981. In 565 men and women aged 38-82 years, there were 69 cases of large vessel peripheral arterial disease, 19 of which were severe, and 90 cases of isolated small vessel peripheral arterial disease. In cross-sectional multivariate analysis in men, large vessel peripheral arterial disease was significantly associated with age, pack-years of cigarettes smoked, systolic blood pressure, fasting plasma glucose, and marginally with obesity. Similar analysis in women revealed significant associations only for age and systolic blood pressure, although the associations for pack-years of cigarettes, obesity, and low density lipoprotein cholesterol were suggestive. By contrast, isolated small vessel peripheral arterial disease was not significantly associated with any of the major cardiovascular disease risk factors, including two measures of carbohydrate metabolism, fasting plasma glucose and glycosylated hemoglobin. These findings, coupled with our earlier report that large vessel peripheral arterial disease but not isolated small vessel peripheral arterial disease was independently predictive of subsequent mortality, suggest that large vessel peripheral arterial disease and isolated small vessel peripheral arterial disease are epidemiologically, as well as pathophysiologically, distinct entities.

Adult↗
PubMed1988

Determinants of internal migration in Israel: expected returns and risks.

"A multinomial logit model of place-to-place migration focusing on economic, geographic and demographic factors is applied to empirical data on inter-regional migration in Israel in 1980. It explains 75% of the (cross-sectional) variance in the data. The results presented in this paper depart from previous empirical work due to its industrialized context and its focus on risk aversion as a determinant of the migration decision. The results support the Harris-Todaro (1970) hypothesis, and indicate that regional similarities in the structure of industrial employment promote migration."

Asia↗
PubMed1987

Classification of geniculo-cortical relay cells of albino rat dorsal lateral geniculate nucleus by means of multivariate analysis.

It was tested if responses of geniculo-cortical relay (GCR-) cells in rat dorsal lateral geniculate nucleus (dLGN) to diffuse light flashes contain features permitting a separation of the cell population into slow and fast cells like the response latency to stimulation of optic chiasm (OX-latency). The location of neurons within the dLGN found additional consideration. Using hierarchical cluster analysis two clusters were obtained for on- as well as off-like neurons, which reflected to a high degree the classification into slow and fast cells by OX-latency. Two subgroups were detected in the cluster of slow cells. Multivariate discriminance analysis made it possible to separate the cell population into two classes. The latency of primary excitation to flash (primary inhibition for off-cells), the number of impulses in the first excitation peak (duration of inhibitory period) and the location of the cells within the dLGN were suited for this separation differing in 11 up to 17% from that achieved by OX-latency classification.

Animals↗
PubMed1986

Correlates of change in postmenopausal estrogen use in a population-based study.

During the late 1970s, there was a dramatic reduction in postmenopausal estrogen use in the United States, which may have reflected concern over a well-publicized postmenopausal estrogen-endometrial cancer link. The authors studied 310 postmenopausal women in a defined population over the period 1974-1981 to evaluate whether hysterectomy and certain other characteristics predicted change in postmenopausal estrogen use status during this period and, as a secondary issue, whether women who subsequently began postmenopausal estrogen use had different characteristics prior to use, an important question in the evaluation of the relation of postmenopausal estrogen use to morbidity and mortality from cancer, cardiovascular disease, or other diseases in observational studies. The only strong predictor of whether postmenopausal estrogen use would be discontinued was the presence of an intact uterus. Women who discontinued postmenopausal estrogen use were also somewhat older and heavier than those who continued, but were otherwise quite similar on a wide range of variables, including risk factors for and the presence of various chronic diseases. Similarly, the absence of a uterus was the only strong predictor of the initiation of postmenopausal estrogen use. Thus, concern about a possible postmenopausal estrogen-endometrial cancer link appeared to have been the major determinant of change in postmenopausal estrogen use in this time period. In the secondary analysis, variables other than hysterectomy did not discriminate between women who initiated postmenopausal estrogen use versus those who did not report use of postmenopausal estrogens, suggesting that a broad range of other characteristics was not a priori different in these two groups.

Aged↗
PubMed1985

Regional distribution of fast and slow geniculo-cortical relay cells (GCR-cells) within the rat's dorsal lateral geniculate nucleus (LGNd).

Unit activity of 135 GCR-cells in rat's LGNd was recorded extracellularly using micropipettes filled with trypan blue for subsequent marking of recording sites. The latencies of responses to electrical stimulation of the optic chiasma (OX) were mapped, and in accordance with Fukuda (1973) each GCR-cells was classified as fast or slow. Fast cells predominate in the rostroventromedial subregion and slow cells in the caudal part. Both fast and slow subtypes were found in the remaining rostrodorsolateral zone where slow cells made up two thirds of the subsample. The results fit the suggestion that in the LGNd of rats a fast retino-geniculate pathway relays in the ventromedial region, whereas slow pathways exist in the caudal as well as in the dorsolateral zone.

Animals↗
PubMed1985

The prevalence of peripheral arterial disease in a defined population.

Because patients with peripheral arterial disease (PAD) may be asymptomatic or may present with atypical symptoms or findings, the true population prevalence of PAD is essentially unknown. We used four highly reliable, sophisticated noninvasive tests (segmental blood pressure, flow velocity by Doppler ultrasound, postocclusive reactive hyperemia, and pulse reappearance half-time) to assess the prevalence of large-vessel PAD and small-vessel PAD in an older (average age 66 years) defined population of 613 men and women. A total of 11.7% of the population had large-vessel PAD on noninvasive testing, and nearly half of those with large-vessel PAD also had small-vessel PAD (5.2%). An additional 16.0% of the population had isolated small-vessel PAD. Large-vessel PAD increased dramatically with age and was slightly more common in men and in subjects with hyperlipidemia. Isolated small-vessel PAD, by contrast, was essentially unrelated to sex, hyperlipidemia, or age, although it was somewhat less common before age 60. Intermittent claudication rates in this population were 2.2% in men and 1.7% in women, and abnormalities in femoral or posterior tibial pulse were present in 20.3% of men and 22.1% of women compared with the noninvasively assessed large-vessel PAD rate of 11.7%. Thus assessment of large-vessel PAD prevalence by intermittent claudication dramatically underestimated the true large-vessel PAD prevalence and assessment by peripheral pulse examination dramatically overestimated the true prevalence.

Adult↗
PubMed1985

The sensitivity, specificity, and predictive value of traditional clinical evaluation of peripheral arterial disease: results from noninvasive testing in a defined population.

In a companion article we have reported the prevalence, in an older, defined population, of traditional assessments (intermittent claudication and abnormal pulse examination) of peripheral arterial disease (PAD) as compared with the results of highly accurate noninvasive testing. In this article we report the sensitivity, specificity, and positive and negative predictive values for claudication and abnormal pulses for the diagnosis of large-vessel and small-vessel PAD as determined by noninvasive testing. Claudication and abnormal pulses were completely unrelated to isolated small-vessel PAD. In contrast, both claudication and abnormal pulses were significantly correlated with large-vessel PAD. Claudication and an abnormal femoral pulse showed a high specificity and positive predictive value but a low sensitivity for large-vessel PAD. Conversely, an abnormal dorsalis pedis pulse showed a good sensitivity but low specificity and positive predictive value. The best single discriminator was an abnormal posterior tibial pulse, which had high sensitivity, specificity, and positive predictive value. Various combinations of claudication and pulse abnormalities revealed a good sensitivity for broader criteria but at the expense of specificity, whereas stricter criteria had a good specificity and positive predictive value but a poor sensitivity. No combination was superior to an abnormal posterior tibial pulse alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Antigen overlay technique for line immunoelectrophoresis and crossed-line immunoelectrophoresis of thermolabile antigens.

A simple antigen overlay technique for line immunoelectrophoresis and crossed-line immunoelectrophoresis is described. A blind gel is overlaid with antigen-impregnated filter paper instead to mix antigens with molten agarose and to pour them in a uniform sample gel. This makes it easier in line and crossed-line immunoelectrophoresis comparison of different antigen samples, simplifying technique as compared with the conventional method. Moreover, this technique is designated to obtain reproducible patterns from thermolabile proteins since they are unaffected by being heated.

Animals↗
PubMed1981

Psychophysical tuning functions for brief stimuli: preliminary report.

Observations from clinical and research applications of brain stem evoked response audiometry and electrocochleography have suggested that tone bursts of only a few milliseconds' duration can elicit frequency specific responses. Because such brief stimuli are not perceived as being total, the extent to which the auditory system can "tune" to such stimuli was questioned. In order to investigate this question, psychophysical tuning functions were determined for brief tone bursts (i.e., 1. to 2 msec. duration). The results suggest that in working near normal thresholds (and therefore at relatively low sound pressure levels), brief tone bursts do yield rather frequency specific information. However, the range of sound pressure levels of the stimulus for which the tuning is resonably sharp is limited. the tuning functions show signs of deterioration, particularly in the "tip region," with only modest increases in the sound pressure level above threshold (i.e., typically with 20 dB.). Differences also may be seen between tuning functions for these very brief tone bursts, which in turn are characterized by a so-called click pitch, and those of stimuli long enough to have tonal pitch (i.e., 20 msec.). Finally, tuning functions also were examined for click stimulation, which also revealed some degree of tuning at relatively low levels of stimulation.

Acoustic Stimulation↗
PubMed1980

Computer identification of waves in the auditory brain stem evoked potentials.

The high reliability with which the waves I through V can be identified in auditory brain stem potential (BAEP) recordings suggests the possibility of using the computer to identify the peaks. This paper examines the application of a smoothing algorithm in which detection of zero crossings in the derivative array of the averaged potentials is used to identify waves I--V in clinical BAEP recordings. A comparison of computer wave identification with human evaluation is presented. The results suggest that computer evaluation cannot entirely replace 'manual' evaluation of the waves, but can expedite analysis and alert the clinician to potentially abnormal responses.

Acoustic Stimulation↗
PubMed1980

[Quantitative immunoelectrophoretic methods applied to the immunochemistry of Candida].

Cytoplasmic soluble extracts of yeasts were compared by quantitative immunoelectrophoretic methods. Comparative studies of Candida albicans and Candida tropicalis permitted to confirm the antigenic complexity of fungi and the existence of important cross-reacting antigens between this two yeast, to demonstrate the specificity of the Candida tropicalis cell-wall antiserum and the presence of soluble cell-wall constituents in cytoplasmic yeast extracts. Crossed-line immunoelectrophoresis with and without absorption of antibodies in situ demonstrated four specific antigens unique to Candida albicans group A cytoplasmic extract not shared with the group B. The other procedures used were not sufficient for identification, since the resulting patterns were confusingly complex.

Animals↗