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Biomedical subjects

M E Parker

Publications and source records attributed to M E Parker.

17 recordsLinked to original sources
PubMed1992

Spontaneous alternation and inhibitory avoidance impairments with morphine injections into the medial septum. Attenuation by glucose administration.

Peripheral glucose administration attenuates impairments produced by peripheral injections of the opioid agonist, morphine, on spontaneous alternation. Injections of opioid agonists directly into the medial septum also impair memory. The present experiments examined whether systemic and intraseptal glucose injections could attenuate deficits on spontaneous alternation and inhibitory avoidance in rats treated with intraseptal morphine. Morphine (3.95 nmol) injected into the medial septum significantly impaired performance on spontaneous alternation and inhibitory avoidance tasks. Both systemic (100 mg/kg, i.p.) and intraseptal (18.33 nmol) injections of glucose, administered concomitantly with intraseptal morphine, attenuated the morphine-induced impairments on these tasks in rats. These findings suggest that one brain region where glucose may act is the medial septum, possibly by releasing opioid inhibition of cholinergic activity.

Animals↗
PubMed1992

Involving nursing staff in research. A non-traditional approach.

The staggering complexity of issues that affect nursing service requires the participation of nurses at all practice levels in the continuing development of the knowledge and practice of nursing. The authors describe a practical application of a nursing research and development method in which nursing values are integrated with elements of non-traditional research approaches.

Group Processes↗
PubMed1992

Isolation and identification of psittacid herpesvirus 1 from imported psittacines in South Africa.

Acute deaths occurred in 47 out of a total of 131 imported psittacine birds whilst in quarantine. Few and non-specific clinical signs were seen during the course of the disease outbreak, but gross pathology revealed severe hepatomegaly and splenomegaly. A herpes virus was isolated from liver and spleen material taken from 2 birds, an Amazon (Amazona aestiva aestiva) and a Yellow-collared macaw (Ara auricollis). Identification procedures included virus neutralisation tests carried out in chicken embryo fibroblast cultures. Neutralisation of the virus was obtained by antisera to Psittacid herpesvirus type 1 (HV1) but not against HV2 or HV3.

Animals↗
PubMed1991

Intercellular communication through gap junctions: a potential role in pharmacomechanical coupling and syncytial tissue contraction in vascular smooth muscle isolated from the human corpus cavernosum.

Kinetic and steady-state protocols were used to examine the effects of disruption of intercellular communication with heptanol, on contractile responses elicited by activation of the alpha 1-adrenergic receptor in human corporal vascular smooth muscle. For the steady-state studies, strips of corporal tissue from 19 patients were submaximally precontracted with phenylephrine (PE) and then relaxed by the cumulative addition of heptanol. Heptanol completely and reversibly relaxed all tissues studied in a concentration-dependent manner. The heptanol concentration response data were then computer fit to the general logistic equation to obtain pEC50 (negative logarithm of the concentration that elicits one-half of the maximal effect) and slope factor values, with Emax (maximal relaxation) set to 100%. The mean pEC50 and slope factor values, respectively, were 2.86 +/- 0.04 and 1.86 +/- 0.17. Furthermore, kinetic studies on corporal tissues from a subset of the patient population (11 patients) revealed that preincubation of tissues with 2 mM heptanol caused a significant decrease in both the rate and magnitude of PE-induced contractions in all tissues studied, without affecting the rate constant for onset of contraction (k(obs)). The present results on intact tissue extend our previous observations on cultured corporal cells, and support the supposition that intercellular communication through gap junctions may play an important role in the initiation, maintenance and modulation of alpha 1-adrenergic contractions in human vascular smooth muscle.

Adult↗
PubMed1985

Treatment of familial antithrombin-III deficiency with danazol.

3 individuals from 2 unrelated families with recurrent thromboses and quantitative deficiencies of antithrombin III (AT-III) were treated with danazol, 600 mg daily for 4 months. Significant increases of AT-III (p less than 0.025) measured as heparin cofactor activity were noted in 1 female and 1 male patient. Failure to augment levels in the other male patient may have been due to poor absorption of the drug following small bowel resection for mesenteric infarction. Side effects of estrogen deficiency necessitated dosage reduction in the female patient. The 2 males experienced no adverse side effects except for prolongation of the prothrombin time in 1 who was receiving oral anticoagulants. We conclude that danazol causes a significant increase in some individuals with familial AT-III deficiency. Additional studies are necessary to determine whether this form of therapy may prove to be a suitable alternative to long-term anticoagulation and to assess the long-term clinical benefits in individuals with recurrent thrombosis.

Adolescent↗
PubMed1979

Focal nodular hyperplasia and adenoma of the liver. A pediatric experience.

Focal nodular hyperplasia and adenoma of the liver together represent approximately 2% of all primary hepatic tumors and tumor-like lesions in childhood. This study reports the clinical and pathologic features of focal nodular hyperplasia in three children, all females between 27 months and 15 years of age with asymptomatic hepatomegaly. In contrast, massive hemoperitoneum from a ruptured, hemorrhagic mass was the presentation of the hepatic adenoma in a 14-year-old girl. There was no history of administration of steroids in these four children. Angiography in two cases (one case each of focal nodular hyperplasia and hepatic adenoma) revealed hypervascular lesions with abnormal tortuous vessels suggesting a malignant tumor. Pathologically, the adenoma and focal nodular hyperplasia were readily distinguishable and the necessity for this differentiation was reviewed. All four patients are currently doing well.

Adolescent↗