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Biomedical subjects

R Singer

Publications and source records attributed to R Singer.

At least 55 records · Page 3Linked to original sources
PubMed1992

Cyclophosphamide, doxorubicin, dexamethasone and procarbazine: effect on seminal plasma sialyltransferase activity.

The influence of chemotherapy agents, doxorubicin (adriamycin), cyclophosphamide, procarbazine, and dexamethasone on the activity of sialyltransferase in human semen has been examined. Aliquots of 25 mcL semen were incubated for 2 hours with the above substances at concentrations ranging from 10 to 800 mcg/incubation mixture. The measurement of sialyltransferase activity was based on the incorporation of radioactive sialic acid from CMP (14) C sialic acid) into asialofetuin. Doxorubicin and cyclophosphamide, at the maximal concentration of 800 mcg/incubation mixture exhibited an inhibiting effect on sialyltransferase activity which accounted for 15.7 +or- 16% and 12.2 +or- 16%, respectively. The rate of inhibition following incubation with maximal doses of dexamethasone (400 mcg) was 25.3 +or- 13%, respectively. The rate of inhibition following incubation with maximal doses of dexamethasone (400 mcg) was 25.3 +or- 12%. Inhibition caused by procarbazine did not exceed 5%. Inhibition of sialyltransferase in human semen by the materials examined in this study can diminish the transfer of sialic acid, thus interfering with normal glycoprotein's and glycolipid's syntheses in semen and possibly also in other fluids and tissues.

Asia↗
PubMed1991

Intravenous immunoglobulin for Flavobacterium-induced thrombocytopenia in a premature infant.

Gram-negative septicemia at times causes morbidity and mortality in newborn nurseries. Prophylactic intravenous immunoglobulin results in a significant decrease in incidence and severity of septicemia resulting from infection in infants. The present case report describes the successful use of high-dose intravenous immunoglobulin in a Flavobacterium-induced thrombocytopenia in a premature infant.

Bacterial Infections↗
PubMed1991

Self report and performance-based hand function tests as correlates of dependency in the elderly.

Preventing or minimizing functional dependency in older adults rests, in part, upon the ability to predict who is at risk. The purpose of this study was to compare the ability of five tests of hand function to discriminate the degree of dependency in older adults. Seven hundred sixty four subjects were assessed for hand function on performance-based (Williams Test of Hand Function, a test of Williams Board items only, Jebsen Test of Hand Function, grip strength), and self-reported (Dexterity Scale of the Geriatrics-Arthritis Impact Measurement Scale (GERI-AIMS] measures of hand function, and self-reported multidimensional functional status (GERI-AIMS). A trichotomous variable representing a continuum of dependency based upon living site (independent living, home-bound, institutional) was used as the measure of dependency. Sixty-two cases were dropped for incomplete data. Discriminant function analyses of the 702 subjects (age X = 76.78 years, SD = 8.79) showed that basic demographic variables explain 40.8% of the variance in dependency; all hand function tests significantly correlated with dependency; the Williams Board correlated best (additional 12.5% variance explained). However, a multidimensional functional status measure explains substantially more variance in dependency (16.9%) after controlling for demographic variables and performance on the Williams Board. This comparison of methods and tests available for measuring hand function was made to provide criteria for selecting an instrument for a given setting.

Activities of Daily Living↗
PubMed1990

The safety and tolerability of quinapril.

Quinapril, a new angiotensin-converting enzyme (ACE) inhibitor with an intermediate duration of action, has been extensively studied in patients with hypertension and congestive heart failure (CHF) during a worldwide clinical development program. A comprehensive safety data base was established to allow appropriate analyses of the extensive patient safety data. The safety of quinapril has been evaluated in 2,697 patients with hypertension and CHF, including 451 elderly patients (greater than or equal to 65 years), and has been compared with safety data from a total of 1,058 patients receiving a comparative therapy. A comparison of the double-blind studies demonstrated that quinapril has a lower incidence of adverse events and/or withdrawals than reported for captopril or enalapril. An analysis of the onset of adverse events did not show either an increase with time on quinapril therapy or a dose relationship. The proportion of patients who experienced orthostatic hypotension or hypotension was less than that of patients who were treated with captopril or enalapril. An analysis of all events (from both double-blind and long-term, open-label studies) showed no increase in the incidence of events reported in patients with CHF compared with hypertensive patients. When the data for all studies were combined, an age analysis showed no increase in the total reporting of adverse events in elderly patients compared with the younger patients studied. The incidence of adverse events was lower in those patients not receiving concomitant diuretic therapy. An overall analysis of clinical laboratory data indicated that quinapril did not have significant adverse effects on clinical laboratory parameters when compared with captopril, enalapril, or placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Immunosuppressive activity and polyamine levels of seminal plasma in azo-ospermic, oligospermic, and normospermic men.

Seventy specimens of human seminal plasma obtained from azo-ospermic, oligospermic, and normospermic men were tested for immunosuppressive activity on normal donor lymphocytes. Spermine and spermidine levels in acidic extracts were determined in 32 specimens of seminal plasma from the three groups. The original seminal plasma as well as the neutralized spermine extracts were examined for their effect on the functional activity of the lymphocytes. Seminal plasma obtained from the normospermic and oligospermic semen showed significant immunosuppressive activity, whereas no immunosuppressive activity was induced by seminal plasma from azo-ospermic semen. The latter finding was in accordance with the low spermine levels in azo-ospermic semen, which were about 50% of those found in normospermic and oligospermic seman. Acidic extraction of the seminal plasma of azo-ospermic origin resulted in an increase in spermine levels and also in immunosuppressive activity, demonstrating that in azo-ospermic men spermine is bound probably to a protein and is released after acidification, exerting its immunosuppressive activity only when unbound.

Graft vs Host Reaction↗
PubMed1990

Andrological parameters in men with high sperm counts and possible correlation with age.

Two hundred eighty six human semen samples with sperm counts above 200 million/ml, were divided into 3 groups according to semen volume: (1) less than 1 ml (low), (2) 1 ml-5 ml (normal), and (3) greater than or equal to 6 ml (high). Each group was examined for routine andrological parameters. Also examined was a possible correlation between sperm counts, semen volumes, and ages of patients. The quality of motility (percent and grade) and viability of sperm were generally lowest in specimens with a volume below 1 ml and highest in those of normal volume. Proportions of morphological normality exhibited a similar trend, lacking, however, statistical significance. The mean fructose content of low-volume semen was significantly decreased in comparison with those of normal volume. Patients with low-volume semen and sperm counts above 200 million/ml were older than those with similar sperm counts and normal volume. The mean ages of all patients with high sperm counts of semen were higher than of those with lower sperm counts. It was assumed that in contradiction to specimens with high sperm counts and low volume, those whose volumes range from 1 ml-5 ml should be considered normal with respect to motility, viability, and morphological normality.

Adult↗
PubMed1989

Beta-endorphin and calcitonin in human semen.

The levels of beta-endorphin (beta-E) and calcitonin were estimated in 36 samples of seminal plasma from semen of normospermic, oligozoospermic, and azoospermic origins and in pools of isolated sperm. The mean levels in plasma calculated for all samples examined were 192 +/- 224 pg/ml for beta-E and 754 +/- 397 pg/ml for calcitonin. The amounts in sperm were as follows: for beta-E in pools with sperm counts of 0.1-10 x 10(6)/ml, 157.2 +/- 99.7 pg/10(8) and 27.9 +/- 23.6 pg/ml protein; in pools of greater than 10-30 x 10(6)/ml, 71.2 +/- 41.5 pg/10(8) and 6.5 +/- 1.2 pg/mg protein; in pools of greater than 30-200 x 10(6)/ml, 24.9 +/- 9.7 pg/10(8) and 61 +/- 1.9 pg/mg protein. For calcitonin the amounts were: 501.2 +/- 170.8 pg/10(8) and 27.4 +/- 21.5 pg/mg protein, correspondingly. It was suggested that beta-E and calcitonin present in seminal plasma are synthesized mostly in a compartment of the male reproductive system. The high cellular beta-E and calcitonin levels would be involved in the process of motility through their effect on calcium transport.

Calcitonin↗
PubMed1988

Methodology of forensic neurotoxicity evaluation: PCB case.

Many scientists and doctors are not aware that the level of certainty for litigation purposes differs from that usually associated with scientific studies. Although the 0.05 probability level is commonly used in scientific studies ("beyond a reasonable doubt"), in U.S. civil litigation the diagnostic criteria is "more probable than not" (greater than 0.50 or chance probability level). The following case of PCB neurotoxicity will be discussed within the context of a forensic evaluation. A number of workers were employed by a metal salvage company to strip copper coils from used electrical transformers. Symptoms of neurotoxicity developed in the men, which were evaluated by questionnaire, interview and psychological examination. Neuropsychological and nerve conduction tests were administered. Results showed deficits in nervous system function related to PCB exposure. An individual case is described in detail.

Environmental Exposure↗
PubMed1988

Sialyl transferase in human semen.

The activity of the enzyme sialyl transferase, which is responsible for the transfer of sialic acid, has been examined in the following human seminal plasma: (1) originating from semen with sperm counts above 30 X 10(6)/ml and exhibiting normal values of other andrological parameters; (2) from semen with sperm counts below 25 X 10(6)/ml and with other andrological parameters of poor quality; (3) from semen devoid of sperm. Additionally, enzyme activity was examined in fractionated (split) semen. The activity in plasma based on measurement of radioactivity incorporated into asialofetuin, following incubation in the presence of 14C sialic acid, was expressed as cpm both per volume and per mg protein. There was a tendency for decreased activity with the decrease in sperm density of semen. The difference, however, lacked statistical significance. Enzyme activity in split semen was significantly lower in the first than in the second fraction.

Humans↗
PubMed1988

Endocrinological parameters and cell-mediated immunity postoperation for cryptorchidism.

Andrological and endocrinological parameters and cell-mediated immunity (CMI) were assessed in 25 postpubertal males who had undergone repair of unilateral or bilateral cryptorchidism in childhood or early adolescence. Among 20 patients with unilateral cryptorchidism, approximately 30% had decreased sperm density, whereas among 5 bilaterally affected, 1 was azoospermic and 2 oligozoospermic. In most patients the motility and viability values were normal, although the percentage of morphologically pathological sperm was higher than normal. Levels of testosterone, dihydrotestosterone, LH, and prolactin were within normal ranges in all the patients. Levels of FSH were slightly elevated. These findings may suggest a better fertility prognosis of postcryptorchid oligozoospermic patients than in patients with oligozoospermia of other etiology. CMI toward autologous semen revealed a positive reaction in 80% of the bilateral group and in 45% of the unilateral group. This response might be due to the damage of seminiferous tubules of undescended testis causing unmasking and exposure of antigenic determinants.

Adolescent↗
PubMed1988

Early recognition of toxicity by assessing nervous system function.

Many industrial substances, such as pesticides, solvents, and heavy metals, are toxic to the human nervous system. Nervous system function provides an excellent means for assessing the early effects of toxic substances. A large percentage of occupational chemicals that are recognized to produce adverse health effects in general also adversely affect the nervous system. Reliable and low-cost methods, including psychometric tests and nerve conduction velocity assessment, have been developed for evaluating nervous system function. By monitoring nervous system function in workers exposed to neurotoxic chemicals, early signs of chemical toxicity can be detected. Appropriate action following detection of early signs of neurotoxicity may then avert permanent and debilitating nervous system disorder and may help to limit exposure to toxic substances affecting other organ systems as well as the nervous system. A monitoring program along with its rationale is described in this paper.

Brain Diseases↗
PubMed1988

Pulse oximeter in the ambulatory aesthetic surgical facility.

One-hundred consecutive patients undergoing aesthetic surgical procedures with adjunctive intravenous sedation in an office-based ambulatory surgical facility were monitored by an anesthesiologist with an ECG, stethoscope, automatic sphygmomanometer, and pulse oximeter. The pulse oximeter detected hypoxemia occurring intraoperatively and in the recovery room earlier than the traditional methods of monitoring. By detecting early drops in the SAO2 with the pulse oximeter, appropriate corrective measures could be instituted and titration of intravenous anesthetics adjusted, avoiding progression to more profound hypoxemia and thus resulting in the safer delivery of anesthesia. The pulse oximeter is a useful and recommended adjunct to the traditional methods of monitoring in an office-based ambulatory surgical facility.

Adolescent↗
PubMed1988

Laboratory evaluation of the Du Pont "Dimension Clinical Chemistry System".

We evaluated the analytical performance of the Du Pont Dimension Clinical Chemistry System to assess its suitability as a replacement for the Du Pont aca III, currently routinely used for analysis of pediatric, high-risk, and emergency specimens. Twenty-six analyses were studied. These generally fulfilled pre-set analytical goals for precision based on biological variation or "state of the art." Significant economies were achieved and we found the Dimension to be reliable, easy to operate, and simple to maintain. It also fulfilled safety requirements for analysis of specimens of high risk to laboratory staff.

Autoanalysis↗
PubMed1987

Decreased semen quality in a male infected with malaria.

A 33-year-old male of proven fertility suffered six attacks of malaria while resident in an African country. For this he received anti-malarial drugs. Semen analysis performed after the fourth attack, and repeated during the following 2 years after his return to Israel, revealed severe oligozoospermia, necrozoospermia and occasionally even azoospermia. Immunological examination of the patient revealed an inverse ratio of T-cell subsets and mast cell degranulation in response to palludrin. Twenty-five months after the last attack of malaria a significant improvement was found in semen quality and there was an increase in the ratio of T-helper to T-suppressor cytotoxic cells. These observations indicate that although malaria and its treatment may affect spermatogenesis, recovery may be expected eventually.

Adult↗