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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
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↗
PubMed1986

Hyperthermia induced by open-field stress is blocked by salicylate.

Psychological stress results in a rise in body temperature. Here we report that in rats, hyperthermia induced by open-field stress can be blocked by administration of the antipyretic drug sodium salicylate. These data suggest that this rise in body temperature is a true fever, perhaps mediated by prostaglandins.

Animals↗
PubMed1986

Oligozoospermia, asthenozoospermia, and sperm abnormalities in ex-addict to heroin, morphine, and hashish.

A 40-year-old male had been addicted to heroin, morphine, hashish, and other narcotics for 12 years. At examination, 2 years after abstinence from drugs, his semen analysis revealed oligozoospermia, asthenozoospermia, and morphologically abnormal spermatozoa such as "round-headed" and "kinked"--sperm with neck abnormalities and immature forms. There was no evidence of other morphological abnormalities or of the presence of morphologically normal sperm. A possible correlation is discussed between the long-lasting drug addiction and morphological sperm abnormality, endocrinological function, karyotype, and immunological status.

Adult↗
PubMed1985

Polymyxin B use does not ensure endotoxin-free solution.

Polymyxin B is often added to in vitro samples to 'ensure' that endotoxin activity is removed. We present data, from the standard rabbit pyrogen test and the Limulus amebocyte lysate assay, that polymyxin B bound to a gel support will bind some, but not all, endotoxin. These data, in conjunction with previously published data by Morrison and Curry (1979), indicate that those studies that have relied on polymyxin B to inactivate endotoxin must be re-evaluated.

Chromatography, Affinity↗
PubMed1985

Beta-endorphin in normozoospermic and pathologic human semen.

beta-Endorphin was estimated in normozoospermic, oligozoospermic and azoospermic human semen. The mean amount in normozoospermic specimens was 278.6 +/- 43.6 (SE) pg/ml while in the others only 191.1 +/- 25 pg/ml. Both values are significantly higher than those present in the blood.

Adult↗
PubMed1985

Immediate free vascularized joint transfer from second toe to index finger proximal interphalangeal joint: a case report.

The results of treatment of severe injuries to the proximal interphalangeal joint are unsatisfactory. The methods of joint reconstruction are discussed, including fusion, implant arthroplasty, perichondrial grafting and vascularized joint transfer. A patient is presented with a severe crush injury to the dorsum of the index finger with loss of skin and extensor tendon and proximal interphalangeal joint disruption. Immediate reconstruction of the finger is described using a composite free flap of skin, extensor tendon and proximal interphalangeal joint from the second toe. Follow-up at two years is described, demonstrating proximal interphalangeal motion and finger function.

Adult↗