Biomedical subjects
Publications and source records attributed to D Powell.
Management of people in this phobia clinic is based on a theory that phobias result from misinterpretations of the effects of a natural process that generates fear in responses to imagined dangers as in a nightmare. With support, guidance, exposure, and information, phobic people learn in individual and group settings to confront, control, and understand their phobic experience.
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We have determined the relative amounts of subunits of larval serum proteins (LSPs) 1 and 2 during larval development in Drosophila melanogaster. These results indicate that synthesis of polypeptide subunits of LSP-1 and LSP-2 is coordinate: the proteins are first detected at the same time; they accumulate in a coordinate fashion; their RNAs are first detected at the same time; the RNAs also accumulate in similar relative amounts. Analyses of fat body polypeptides and fat body RNA indicate that synthesis of LSP-1 declines at a time when there are still substantial quantities of LSP-1 RNA in the cytoplasm. Cessation of LSP-1 subunit synthesis occurs before cessation of LSP-2 synthesis, indicating that at late times the genes (or mRNAs) for these two proteins are subject to different "switch-off" controls.
Twenty-one families with familial Alzheimer disease were ascertained in a dementia clinic and assessed by multiple family interviews. Eight autopsies were reviewed. The age of onset varied from 25 to 85. Seven pedigrees showed evidence of 3 generation transmission. Paternal age of the founders of 4 lines which could be assessed was higher than controls.
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Thrombocytopenia is frequently encountered in patients with lymphoproliferative disorders (LPD) and systemic erythromatosus (SLE) and to a lesser extent in association with other diseases such as rheumatoid arthritis (RA), pernicious anaemia (PA) and autoimmune haemolytic anaemia (AIHA). This report attempts to document the incidence of thrombocytopenia in these disorders, other than that overtly due to malignant infiltration or marrow suppression by drugs and to demonstrate, that in a significant proportion antibody mediated immune destruction of platelets can be confirmed by positive platelet antibody tests. Platelet associated IgG (PAIgG) was measured in all patients by a quantitative enzyme linked assay. Platelet antibodies were found in 11 of 24 (46%) thrombocytopenic patients with LPD, 10 of 16 (62%) patients with SLE and thrombocytopenia, and in all patients with RA and PA who had low platelet counts at the time of study. In addition, elevated PAIgG levels were found in the following non-thrombocytopenic patients: 9 of 43 (21%) patients with LPD, 2 of 12 (17%) with SLE, 2 of 12 (17%) with AIHA, 2 of 39 (5%) with PA and 5 of 61 (8%) patients with RA. The nature and the role of raised PAIgG levels in diseases other than autoimmune thrombocytopenia is controversial. Our reasons for interpreting these as true platelet autoantibodies in this selected group of disorders and the clinical implications of our results are discussed.
The effects of chronic administration of cyclophosphamide and procarbazine on testicular function in the rat were examined. Cyclophosphamide produced disruption of the normal spermatogenic architecture that was dose and time dependent. Total ablation of the germinal epithelium was not achieved. Procarbazine produced more specific testicular damage. Multiple weekly injections of 100-200 mg/kg of procarbazine caused complete destruction of the spermatogenic cells, with no effect on Sertoli cells. Treated animals remained infertile for more than 4 months and showed no histologic evidence of recovery. This model may be useful for examining possible mechanisms to prevent spermatogenic damage associated with cancer chemotherapy in man.
A 2 1/2 year old boy accidentally ingested the herbicide diquat. Progressive neurologic dysfunction preceded his death 143 hours after poisoning. Brain stem infarction and purpura were noted at post mortem and closely resembled the brain stem pathology in 3 of 7 adults who died after diquat ingestion. Renal, gastrointestinal and pulmonary involvement in this child also resembled that seen in adults after ingestion of diquat. Hemoperfusion was performed six times in an effort to lower the body diquat burden. Cellulose-coated, activated charcoal was first employed 40 hours postingestion and removed diquat from serum with clearances of 104 and 39 ml/minute at the initiation of hemoperfusion and 6 hours later, respectively. Serum diquat concentrations decreased rapidly during charcoal hemoperfusion. However, marked rebound in serum diquat concentrations were noted between charcoal treatments, indicating extensive sequestration of diquat by tissues. Thrombocytopenia and hypocalcemia, the major complications of charcoal hemoperfusion, were easily treated. Unlike charcoal, Amberlite XAD-4 resin hemoperfusion did not remove diquat from serum. Charcoal hemoperfusion may temporarily reduce serum diquat concentrations. Whether the early institution and daily performance of charcoal hemoperfusion will minimize diquat-induced damage to brain and other organs is not clear from this case and will only be determined in future studies.
The occurrence and distribution of the neurohormone substance P in the urogenital tract suggest a role for substance P in regulation of blood flow, smooth-muscle activity, and sensation. The distribution and pharmacologic effects of substance P in the brain suggest an involvement of substance P in regulating the release of gonadotropins and prolactin from the pituitary and in the gonadal-hypothalamic feedback. As substance P is also present in endocrine-like cells of the diffuse endocrine system in the urogenital tract, it may serve as a tumor marker for carcinoid and related tumors, particularly in the ovary and the uterine cervix. This review is limited to the distribution and effects of substance P in the female genital tract and its relevance in female reproduction.
The clinical and biochemical effects of continuous ambulatory peritoneal dialysis in 20 children and of hemodialysis in 16 children were compared over a 2 1/2-year period. Statistically significant differences between the treatment groups included higher hematocrit, higher serum carbon dioxide and cholesterol levels, large intake of calories and protein, and lower systolic blood pressure and rates of transfusion in the patients receiving continuous ambulatory peritoneal dialysis. These patients had more complications than the patients receiving hemodialysis, but hospitalization rates in the two groups were similar. The cost of continuous ambulatory peritoneal dialysis was +19,600 per patient-year; the cost of hemodialysis was +54,300 per patient-year; the cost of hemodialysis was +54,300 per patient-year. There were four treatment failures with continuous ambulatory peritoneal dialysis and one with hemodialysis. Patients treated with both forms of dialysis preferred continuous ambulatory peritoneal dialysis. We conclude that continuous ambulatory peritoneal dialysis is an important alternative to hemodialysis in children.
The response of bulky, advanced Stage 1B and early Stage II carcinoma of the cervix to neutron brachytherapy (NT and radiotherapy) was studied using combined NT radiation and extrafascial hysterectomy with histologic evaluation. Scheduling of neutron therapy relative to external beam photon therapy, tumor volume, tumor stage, tumor histology, and clinical tumor clearance were assessed in these studied. NT was easily combined with surgery in this study. Low stage tumors, small tumor volume and "early" neutron implants (scheduled within +/- one week of the start of fractionated radiation) showed more frequent histologic clearance of tumor. Long-term tumor control has been achieved and failures developed distance metastases without pelvic or local recurrence. This experience indicates that NT was effective for tumor clearance and control and represents and promising new modality for localized, advanced tumor therapy.
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The records of a sample of Family Planning acceptors were examined to identify those factors which influenced the choice of a contraceptive and the drop-out rate in the period 1970--1977 inclusive. It was found that although a full range of contraceptives was theoretically available, as the 1970s advanced the effective choice appeared to lie between the two hormonal contraceptives, medroxyprogesterene acetate (Depo Provera) and the oral contraceptive pill with family size being the deciding factor. The drop-out rate as also influenced by family size with nulliparous women showing the highest rate. Explanations for the drop-out rates and the percentage of single visits made to the clinics were sought through the utilization of partial correlations. In both cases the average distance between the acceptor's home and the clinic appeared to play a decisive role.
Elevated plasma calcitonin was detected by radioimmunoassay in 19 of 99 unselected cancer patients (19%). The frequency of hypercalcitoninaemia in patients with tumours of lung, uterus, gastrointestinal tract, and urinary bladder was about 40%, in carcinoma of the breast 18%, and in carcinoma of the skin 4%. In 8 patients with bone metastases, 4 were hypercalcitoninaemic. None of 19 patients with non-malignant disorders had elevated plasma calcitonin. The highest plasma calcitonin level in cancer patients was 8200 ng/l. Urinary cyclic AMP was elevated in patients with hypercalcitoninaemia as compared with patients with normal plasma calcitonin. All 6 patients with medullary carcinoma of the thyroid had very high plasma calcitonin levels: more than 50000 ng/l in five and 30000 ng/l in one patient. Of the family members of these patients, raised plasma calcitonin was detected after stimulation with oral alcohol in 6 of 12. It is concluded that plasma calcitonin levels in excess of 10000 ng/l suggest the presence of medullary carcinoma of the thyroid, while levels below 10000 ng/l have a poor diagnostic value but should alert the clinician to look for a possible malignancy.
The aim of the present study was to find a relation between the Substance P (SP) content in the median eminence and the pituitary gland in rats and hypothalamic regulaton of the oestrus cycle. SP content was measured by radioimmunoassay in female rat pituitary and median eminence during oestrus, dioestrus and after anterior hypothalamic deafferentation. SP content in rat's pituitary did not vary significantly among individual groups of animals. The greatest average SP content in rat's median eminence was found in dioestrus. Both during cyclic and constant oestrus resulting from anterior hypothalamic deafferentation SP content in median eminence was lower than in dioestrus. This fact indicates the possibility of SP involvement in the control of cyclic LH-RH release from hypothalamus.