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Biomedical subjects

M Schulzer

Publications and source records attributed to M Schulzer.

At least 163 records · Page 9Linked to original sources
PubMed1984

Covariates of the long-term fluctuation of the differential light threshold.

The scatter of the differential light threshold has a short-term and a long-term component. Although these components are significantly positively correlated, the relationship is not strong enough to accurately predict in an individual patient the long-term fluctuation from the short-term fluctuation. The reversible variation of the retinal sensitivity with time is statistically related to the temporal variation of the short-term scatter, to the variation in reaction time, and probably to the variation in the intraocular pressure.

Differential Threshold↗
PubMed1984

Neuroretinal rim area in suspected glaucoma and early chronic open-angle glaucoma. Correlation with parameters of visual function.

The cup-disc ratio is an indirect measure of the amount of neural tissue present at the optic nerve head. A large cup-disc ratio in a large disc may be accompanied by a normal neuroretinal rim. The area of the neuroretinal rim is relatively constant in normal persons and should relate to visual function. In 39 eyes of patients with suspected glaucoma, normal subjects, and patients with early open-angle glaucoma, biometric findings, psychophysical functions, and optic nerve measurements were studied. The area of the neuroretinal rim was determined from stereophotographs and corrected for the magnification by the optical components of the eye. A statistically significant relation between this neuroretinal area and parameters of visual function was found. The cup-disc ratio correlated more weakly with visual function. Covariant analysis showed the neuroretinal area to be the only parameter capable in our sample of discriminating among the three clinical groups.

Adolescent↗
PubMed1984

The effect of age on the nerve fiber population of the human optic nerve.

Nerve fiber counts of 16 normal human optic nerves from subjects aged 3.5 to 82 years showed a significant effect of age (P = .0207). The delay between death or enucleation and fixation also significantly affected the result (P = .0078). The mean (+/- S.E.M.) count for the 16 nerves was 1,244,005 +/- 20,033 fibers, giving a 99% confidence level between 1,192,400 and 1,295,610 fibers.

Adolescent↗
PubMed1984

Host factors affecting longitudinal decline in lung spirometry among grain elevator workers.

The host factors affecting the longitudinal decline in lung function among 267 white male grain elevator workers who were still working in the industry and did not change their smoking habits over a period of six years were studied. Spirometric measures declined more rapidly in older grain handlers as compared with younger workers. Smokers had slightly greater decline in spirometry compared to nonsmokers, but the differences failed to reach the level of statistical significance. Acute changes in lung function over the course of one work week during the initial study were also positively correlated with subsequent decline in lung function, as was bronchial hyperreactivity determined during the follow-up study. Positive immediate skin reactivity to common allergens, presence and absence of respiratory symptoms, and initial lung function did not appear to influence the subsequent decline in lung function in this group.

Adult↗
PubMed1983

Prospective immunological assessment of arthritis induced by rubella vaccine.

A prospective study was carried out to correlate the development of joint symptoms after rubella immunization with pre- and post-immunization rubella-specific immunological responses. Arthralgia or arthritis or both occurred in 10 of 37 adult female volunteers at a mean time of 17.0 days after immunization with the RA 27/3 rubella vaccine. All individuals studied before immunization were seronegative for rubella by either the hemagglutination inhibition or the single radial hemolysis technique. In contrast, rubella enzyme-linked immunosorbent assay or lymphoproliferative responses or both were positive in 27 of 37 (73%) individuals tested before receiving the vaccine. Rubella enzyme-linked immuno-sorbent assays carried out before immunization were positive at high levels (mean E = 0.536) in four individuals who developed recurrent episodes of arthritis after administration of the vaccine while remaining at low levels preimmunization in subjects who developed transient arthralgia (E = 0.238) or no joint manifestations at all (E = 0.288). These data provide preliminary evidence suggesting that rubella vaccine-associated arthritis may occur as a consequence of secondary, rather than primary, infection with rubella virus and that the presence of circulating, nonneutralizing rubella antibody may enhance the development or severity (or both) of the associated postinfection joint manifestations. Assessment of rubella hemagglutination inhibition, hemagglutination inhibition (immunoglobulin M), and enzyme-linked immunosorbent assay serological responses at 6 weeks and 6 months post-immunization revealed no significant differences between patients who developed and those who did not develop joint manifestations. Rubella lymphoproliferative responses were elevated at 6 weeks post-immunization in the group developing arthralgia or arthritis or both, with no difference between the groups observed at 6 months post-immunization.

Adult↗
PubMed1983

Epidemiologic health study of workers in an aluminum smelter in British Columbia. Effects on the respiratory system.

A health survey was carried out on all white males in an aluminum smelter in British Columbia. The survey consisted of a medical-occupational questionnaire, spirometry, chest radiography, and environmental monitoring. We have compared the results of a respiratory survey in 713 workers in the office and casting department with no significant exposure to air contaminants (control workers) with those of 797 potroom workers: 495 who spent more than 50% of their working time in the potroom (high exposure) and 302 workers who spent less than 50% of their working time in the potroom (medium exposure). Potroom workers (high) had a significantly greater prevalence of cough and wheeze than did those in the control group, and they had significantly lower mean forced expiratory volume in one second and maximal midexpiratory flow rate than did those in the control group after adjustment had been made for differences in age, height, and smoking habits. Potroom workers (medium) had a slightly greater prevalence of respiratory symptoms and lower lung function than did workers in the control group, but the differences were not significant. We were unable to demonstrate potroom asthma. The levels of total fluoride, gaseous fluoride, particulate fluoride, sulphur dioxide, and total particulates found in the potroom at the time of the study were below the currently accepted threshold limit values, but the levels of benzo-alpha-pyrene were high.

Adult↗
PubMed1983

The structure and function of the pulmonary vasculature in mild chronic obstructive pulmonary disease. The effect of oxygen and exercise.

The structure and function of the pulmonary circulation was investigated in 17 patients requiring pulmonary resection. All 17 performed pulmonary function tests and 13 underwent right heart catheterization preoperatively. The surgical specimens of the lung were analyzed with respect to the severity of the emphysema, the severity of the airways disease, and the hypertensive changes in the small pulmonary arteries and arterioles. The data show that pulmonary artery (Ppa) and pulmonary artery wedge (Ppaw) pressures and cardiac output were normal at rest. However, patients with more severe disease showed greater increases in Ppa and Ppaw with exercise than did patients with minimal or no disease. Oxygen breathing had no effect at rest but lowered Ppa and Ppaw during exercise in the patients with more severe disease. Histologic studies showed that greater degrees of emphysema and small airways disease were associated with hypertensive changes in the pulmonary vasculature. We conclude that patients with moderate obstructive lung disease have elevated pulmonary vascular pressures during exercise and structural changes in the pulmonary arteries consistent with pulmonary hypertension when compared with patients with minimal or no disease. Although there are several possible explanations for the increased vascular pressures seen with exercise, we favor gas trapping leading to increased alveolar and pleural pressures, with oxygen breathing preventing this response by shortening the time constants of the peripheral lung units.

Aged↗
PubMed1982

Cardiovascular effects of epinephrine and dipivalyl epinephrine applied topically to the eye in patients with glaucoma.

The cardiovascular effects of topical ophthalmological preparations of 2% epinephrine (EPI), 0.1% dipivalyl epinephrine (DPE), and placebo were studied in double-blind fashion in 20 patients with glaucoma. Both drugs and placebo produced a decrease in heart rate (2 +/- 3 beats/min) which, although small, was highly significant (p less than 0.001). Neither drug not placebo produced a significant effect on mean or systolic blood pressure (BP) over the group as a whole (p greater than 0.1). However, 5 of 20 patients responded to EPI with a significant rise in mean or systolic BP (defined as a change greater than mean change +/- 2 SD), whereas there were no such responses to DPE or placebo. One patient developed marked ventricular ectopy after EPI. We conclude that EPI may cause cardiovascular side effects in a high percentage of patients (25% in this study) through individual susceptibility rather than a predictable effect. DPE, a new epinephrine analogue, appears to be devoid of these effects.

Aged↗
PubMed1982

Measurement of regional bronchial arterial blood flow and bronchovascular resistance in dogs.

Little is known about normal variations and control of bronchial blood flow and bronchovascular resistance. We have used the reference-flow technique and 15-microns-diameter microspheres to measure bronchial blood flow under physiological conditions. Dogs (n = 13) were anesthetized and ventilated, and their chests were opened. A ligature was placed loosely around the left main pulmonary artery, and the left atrium was cannulated. In six dogs three sets of microspheres were injected simultaneously into the left atrium, and in another seven dogs the three sets of microspheres were injected sequentially at 0.5-h intervals. Prior to each injection measurements of pulmonary arterial, left atrial, and aortic pressures, cardiac output, and blood gases were made. Five seconds after injection the left main pulmonary artery was transiently occluded to prevent recirculation. After the final injection, dogs were killed, the lungs were removed, and the parenchyma was stripped off the large and small airways of the left lung. Knowing the radioactivity in the trachea, bronchi, parenchyma, and in the reference flow blood and also the aortic and left atrial pressures, we calculated bronchial blood flow (ml X min-1 X g dry lung-1) and bronchovascular resistance (cmH2O X ml-1 X min X 100 g dry lung). Results showed that there were no significant differences between the three measurements of bronchial blood flow when microspheres were injected simultaneously or sequentially. Bronchial blood flow to the left lung was 0.4% of cardiac output; 55% of the total flow went to lung parenchyma and 45% to trachea and bronchi. Expressed as flow/g dry lung the greatest flow was to the airways.

Animals↗
PubMed1981

Acquired color vision changes in glaucoma. Use of 100-hue test and Pickford anomaloscope as predictors of glaucomatous field change.

A five-year follow-up of eyes with elevated intraocular pressures, but without field defects, in which the color vision had been assessed by the 100-Hue test and an anomaloscope was carried out. Field defects developed in eight of 42 eyes with a low 100-Hue score, whereas field defects developed in ten of 13 eyes with a high abnormality in the 100-Hue test score. In the case of the anomaloscope (Pickford Nicholson) scores, field defects developed in four of five eyes with poor yellow-blue scores, whereas similar field defects developed in only nine of 40 years with a normal yellow-blue scores. With regard to blue-green scores, field defects developed in six of 11 eyes with a poor blue-green score, whereas field defects developed in only seven of 40 eyes with a normal blue-green score. These differences are statistically significant, and the probabilities of an abnormal color vision the results in subsequent field defects have been worked out. The red-green scores were not predictive.

Color Perception Tests↗
PubMed1981

Multivariate analysis in glaucoma. Use of discriminant analysis in predicting glaucomatous visual field damage.

A discriminant function obtained in 1978 to separate patients with glaucomatous visual field loss from those without visual field loss was shown to have a predictive value in ocular hypertensive persons as to the subsequent development of visual field loss in five years. A prospective discriminant analysis also was carried out to identify those factors that best separate those in whom visual field defects developed from those in whom they did not.

Factor Analysis, Statistical↗
PubMed1981

The effects of age, smoking, and alcohol on routine laboratory tests.

The effects of age, smoking, and alcohol intake on the results of some routine hematology and clinical chemistry tests have been determined for a group of 1,826 healthy male workers. Increasing age was significantly associated with higher hemoglobin, hematocrit, SGOT, BUN, and creatinine levels and with lower total protein concentration, but there was no significant association with leukocyte count, total bilirubin, or alkaline phosphatase. Smoking was significantly associated with higher hemoglobin, hematocrit, leukocyte count, and alkaline phosphatase, and with lower total bilirubin, SGOT, total protein, and BUN, but there was no significant association with creatinine levels. Alcohol consumption was significantly associated with higher hematocrit, bilirubin, and SGOT and with lower BUN and creatinine, but there was no significant association with hemoglobin, leukocyte count, alkaline phosphatase, or total protein. The possible reasons for these effects, and their implications, are discussed.

Adult↗
PubMed1980

Neurological, psychological and educational sequelae of low birth weight.

In a prospective study of 501 infants of low birth weight (LBW) who mostly weighed 2,041 g (4 1/2 lb) or less, and of 203 control infants of full birth weight (FBW > 2,500 g), 335 LBW and 139 FBW children were followed beyond the age of 6 years and 6 months. The incidence of neurological defects was negatively correlated with birth weight, and the mean "global" IQ of different birth weight groups retained a direct relationship. While the relationship of birth weight to IQ gradually became less marked, the effect of social class was increasingly evident from the age of 2 years and 6 months. The preterm children whose birth weight was appropriate for gestational age (AGA) attained a slightly higher mean IQ and significantly better grade placement in the third school year than the children who were unduly light for their gestational age. Details of the neurological and ophthalmological defects are given, and the predictive significance of neonatal variables is analyzed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1978

Response to topical epinephrine in chronic open-angle glaucoma.

The epinephrine pressure reduction was determined in 32 patients with elevated intraocular pressure (IOP) and 18 patients with untreated chronic open-angle glaucoma. The prevalence of responders was 53% of those patients with elevated IOP and 56% in those patients with open-angle glaucoma. This lack of difference between the two groups is suggestive of the need for caution before applying epinephrine in clinical practice as a predictive factor of future field loss.

Analysis of Variance↗