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Biomedical subjects

R Parker

Publications and source records attributed to R Parker.

At least 217 records · Page 12Linked to original sources
PubMed1981

In vitro antagonism of benzodiazepine binding to cerebral receptors by H1 and H2 antihistamines.

Antihistamines directed at either the H1 or H2 histamine receptor have the well-known side effect of sedation. The mechanism for the CNS depressant action of antihistamines is unknown. We examine here the possibility that the mechanism may involve modulation of the cerebral benzodiazepine receptor. We demonstrate that cimetidine and pyrilamine are competitive antagonists of 3H-benzodiazepine binding to human cerebral receptor in vitro. The inhibition of radioligand binding was not specific for benzodiazepine receptor, however, since antihistamines also antagonized binding to GABA, opiate, and muscarinic acetylcholine receptor. The interaction of antihistamine with CNS receptors other than histamine receptor may explain, at least in part, the side effect of sedation.

Binding, Competitive↗
PubMed1980

Clinical and cytogenetic studies of patients with polycystic ovary disease.

Chromosomal studies in patients with polycystic ovary disease have produced contradictory findings. Whereas some patients showed various sex-chromosome anomalies, the majority had a normal karyotype. However, banding techniques were not employed in any of those studies. This report presents the result of cytogenetic studies with the use of the trypsin-Giemsa banding technique in 15 patients with polycystic ovary disease. Ten patients had normal karyotypes. In five patients, pseudodiploidy with trisomy 14 was present in 2% to 4% of the cells analyzed. However, the missing chromosome in pseudodiploid cells was not always the same. The phenotype of these patients was normal, except for polycystic ovary disease. The finding of trisomy 14 in 2% to 4% of the cells in five of 15 patients (33%) with polycystic ovary disease is significant, since such an occurrence is extremely rare in the general population. The implication of this cytogenetic finding remains unclear.

Adult↗
PubMed1980

Craniofacial and central nervous system malformations induced by triamcinolone acetonide in nonhuman primates: I. General teratogenicity.

Eighteen pregnant Macaca mulatta, 15 Macaca radiata, and six Papio cynocephalus were treated with 5--20 mg/kg triamcinolone acetonide (TAC) between 21 and 43 days of gestation on single- or multiple-day treatment schedules. Prenatal deaths and stillbirths were tripled in the bonnet monkey and doubled in the rhesus monkey, but did not significantly increase in the baboon. The central nervous system and cranium were the most commonly malformed areas in all three species. The incidence of severe defects, e.g., cranium bifidum, encephalocele, meningocele, and hydrocephalus, was increased in multiple-day treated cases. Minor abnormalities such as aplasia cutis congenita, cranium bifidum occultum, and occipital lobe hypoplasia were more prevalent in single-day treated cases. The sensitive period (days 23--31) for TAC for this group of defects encompasses neural tube closure, rostral demarcation of the midbrain, and development of the primordial collicular plate and two midbrain neuromeres. The results of this study indicate that TAC is a valuable chemical tool for the study of malformations and pathogenesis of the brain and accompanying cranio-facial defects.

Abnormalities, Drug-Induced↗
PubMed1980

Susceptibility of Bos indicus crossbred and Bos taurus cattle to Anaplasma marginale infection.

The effects of infection with Anaplasma marginale in groups of Bos indicus-Brahman crossbred and Bos taurus cattle aged 27 and 48 months were studied using the parameters of body weight change, packed cell volume, parasitaemia and humoral antibody. Twenty-six animals (8 Bos taurus and 18 Bos indicus crosses) of each age group were infected. No significant differences between any of the groups were observed.

Anaplasma↗
PubMed1980

The influence of pH on the enhancement of radiation damage by hyperthermia.

HeLa-S3 cells were treated with heat and/or radiation in medium of pH 7.4 or pH 6.7. A heat treatment at 44 degrees C for 10 min, which alone did not produce any measurable cell killing, was found to enhance the lethal effect of radiation to the same extent at pH 6.7 and 7.4. Heat alone at 44 degrees C for 30 min killed 65 per cent of cells at pH 7.4 and 90 per cent at pH 6.7 and produced a marked radiation sensitization of the survivors but only slightly more at pH 6.7 than at pH 7.4. These results support the suggestion that heat damage responsible for increase in sensitivity to subsequent irradiation is distinguishable from damage which leads to cell death after heat alone, and that heat used as a radiation sensitizer may only give a small therapeutic gain in cancer treatment, based on the lower pH of some tumour cells.

Cell Survival↗
PubMed1980

Comparison of in vivo temperatures produced by hydrotherapy, paraffin wax treatment, and Fluidotherapy.

The effectiveness of a new heat modality, Fluidotherapy, was compared with other superficial heat modalities by in vivo temperature measurements. The joint capsule and muscle temperatures in the hands and feet were measured in subjects treated with hydrotherapy, paraffin wax, and Fluidotherapy. Fluidotherapy is a dry heat modality consisting of finely divided solids suspended in an air stream. The dry heat modality, applied at 118 degrees F (47.78 degrees C), resulted in maximum joint capsule and muscle temperature rises of 16.2 degrees F (9 degrees C) and 9.5 degrees F (5.27 degrees C), respectively, compared to 13.5 degrees F (7.5 degrees C) and 8.1 degrees F (4.5 degrees C) for paraffin wax treatment and 10.8 degrees F (6.0 degrees C) and 7.7 degrees F (4.3 degrees C) for a 102 degrees F (38.89 degrees C) water bath, at a depth of about 0.5 cm beneath the skin. At depths down to 1.2 cm, superficial heat modalities are more effective than diathermy and much more effective than ultrasound in elevating temperature.

Calorimetry↗
PubMed1980

Familial occurrence of chromosome 7/12 translocation.

A new balanced translocation, t(7;12) (p12;p13), was found in a high genetic risk family in which the mother is a translocation carrier. She had 12 pregnancies, six of which were terminated during the first trimester by spontaneous abortions. Among the six live births, three children inherited the translocation from their mother and were phenotypically normal. The father and three other children had normal karyotypes.

Abortion, Habitual↗
PubMed1980

High cancer mortality rates from childhood leukemia and young adult Hodgkin's disease and lymphoma in the New Jersey-New York-Philadelphia Metropolitan Corridor, 1950 to 1969.

In comparison to the United States as a whole and to their total population age-adjusted rates, the New Jersey-New York-Philadelphia Metropolitan Region was found to have excessively high childhood leukemia and high young adult Hodgkin's disease and lymphoma cancer mortality rates in the period from 1950 to 1969.

Adolescent↗
PubMed1979

Intralesional immunotherapy of malignant melanoma with mycobacterium smegmatis cell wall skeleton combined with trehalose dimycolate (P3).

The clinical efficacy of intralesional immunotherapy utilizing Mycobacterium smegmatis cell wall skeleton (CWS) and trehalose dimycolate attached to oil droplets was investigated in 15 patients with advanced malignant melanoma. Patients received 300 microgram to 1050 microgram of the CWS combined with one-half that amount of trehalose dimycolate every 1 to 2 weeks for a total of 8 treatments. Therapy was continued if regression of injected lesions only occurred. Therapy was discontinued if regression of noninjected disease also occurred. Six of the 15 patients had regression of at least one injected lesion. Four of these 6 patients also had regression of noninjected disease lasting 4+, 6, 16 and 18+ months. Response was highly related to immune status. Six (83%) of 7 patients who reacted to one of a battery of skin tests responded. All 8 patients who did not react to skin tests failed to respond to therapy. There was no correlation of response with sex, prior therapy, disease-free interval or presence of visceral disease. Mycobacterial CWS and trehalose dimycolate is an effective immunotherapeutic agent. Additional studies of purified immunoadjuvants are warranted.

Cell Wall↗
PubMed1979

Chemotherapy of acute bovine anaplasmosis.

The efficacy of a standard tetracycline, imidocarb and a new experimental long-acting tetracycline (T-200) in the treatment of anaplasmosis was examined in 5 groups of 9 nonsplenectomised, adult, 4-year-old, speyed cattle. The efficacy of T-200 was further examined using 9 splenectomised calves. One treatment of imidocarb (3.5 mg/kg) or T-200 (20 mg/kg) or 2 treatments (10 mg/kg) of a standard tetracycline were very effective in controlling the infection in the intact cattle. On inoculation of T-200 (20 mg/kg) controlled infection in 5 splenectomized calves, whereas all 4 untreated control calves died. T-200 did not sterilise either intact or splenectomised cattle.

Acute Disease↗