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Biomedical subjects

G Robinson

Publications and source records attributed to G Robinson.

At least 127 records · Page 7Linked to original sources

Operating on HIV-positive patients. What are the risks to healthcare workers? To patients?

Is the degree of risk involved in providing health care to people infected with human immunodeficiency virus (HIV) acceptable? Every health care worker, even if only for a few anxious minutes, has certainly worried about this risk. Drs Wilson, Williams, and Robinson discuss these concerns and summarize the indications and prognoses for surgery to treat some common AIDS-related syndromes.

Acquired Immunodeficiency Syndrome↗

Oxytocin has a role in gonadotrophin regulation in rats.

We previously demonstrated that oxytocin stimulates LH release from rat pituitary cells in vitro and advances follicular development and ovulation in mice in vivo. This study reports an investigation of rat LH levels following in-vivo administration of oxytocin. Injection of oxytocin (10 mIU/g, i.p.) to rats at 07.00, 08.00 and 09.00 h of pro-oestrus or at 09.00, 10.00 and 11.00 h of pro-oestrus advanced the onset of the LH surge (P less than 0.005) and attainment of peak concentrations of LH (P less than 0.02) in peripheral blood. On the other hand, the descending phase of the LH surge and the surge amplitude were not altered by oxytocin. Treatment at 05.00, 06.00 and 07.00 h of pro-oestrus or at 11.00, 12.00 and 13.00 h of pro-oestrus had no effect on the LH profile. A higher oxytocin dose (20 mIU/g) inhibited LH release when treatment was begun at 05.00, 07.00 or 09.00 h of pro-oestrus. A lower dose (5 mIU/g) was ineffective in altering LH concentrations. In addition, injections of oxytocin (10 mIU/g) at oestrus, metoestrus or dioestrus had no effect on the release of LH. Thus the efficacy of oxytocin in altering concentrations of LH was dose dependent and also critically affected by the day of the oestrous cycle and the time of pro-oestrus. Removal of endogenous oxytocin activity by the use of an oxytocin receptor antagonist abolished the pro-oestrous LH surge, indicating that oxytocin is a vital physiological component of the LH-releasing mechanism in rats. The study provides unequivocal evidence that oxytocin induces LH release in vivo, but the manifestation of oxytocin activity is dependent upon conditions of exposure.

Angiotensin Receptor Antagonists↗

Heparin cofactor II levels are increased by the use of combined oral contraceptives.

Heparin cofactor II (HCII) was assayed by a microtitre amidolytic substrate technique. A linear response was obtained up to 1.5 U/ml and HCII levels were not affected by freezing and thawing the plasma. The assay was validated by comparing HCII and antithrombin III (AT III) levels in AT-III-deficient plasmas and samples from critically ill patients. Higher HCII levels were found in healthy normal women than in healthy normal men (means 1.16 and 0.97 U/ml, respectively, P less than 0.01). A significant increase in HCII levels from 0.86 to 1.10 U/ml (mean values) was seen in healthy normal women starting on combined oral contraceptive (COC) preparations (P less than 0.001). Increased HCII levels were maintained over a 6-month period, but fell towards normal 14 days after stopping COC, although they were still significantly higher than before starting COCs. The discrepancy in HCII level between normal men and women may be due to COC use. In clinical studies, different reference ranges should be used for men and women, and the need for careful questioning about the use of COCs is emphasized.

Adolescent↗

The quality of nursing care on wards working eight and twelve hour shifts: a repeated measures study using the MONITOR index of quality of care.

Interest in 12 hr nursing shifts has renewed in response to demands for improved cost effectiveness in the NHS, but the effects of this shift on patient care are unclear. A repeated measures study of 10 wards comparing quality of care, measured by MONITOR, under 8 and 12 hr shifts was conducted. The overall MONITOR scores were significantly lower under the 12 hr shift, with planning, non-physical care and evaluation of care scales showing significant decreases. The pattern of results when data were analysed by patient dependency levels reveals that whilst the quality of care overall for the four dependency categories was significantly poorer under the 12 hr shift, the lower dependency categories were less adversely affected in terms of physical and non-physical care delivered.

Humans↗

Impact of initial quality control review on study outcome in lung and head/neck cancer studies--review of the Radiation Therapy Oncology Group experience.

The Radiation Therapy Oncology Group (RTOG) initiated cooperative clinical trials in 1971. In 1978, RTOG developed a formalized program of Quality Control (QC) divided into initial and final phases. The initial review process consisted of two steps. The first phase of review is an evaluation performed by a radiation oncologist to verify treatment plan and field borders. The second portion of the initial review process originally consisted of dosimetry calculation verification based on machine data provided by the regional Radiological Physics Center and treatment planning data provided by the accessioning institution. Between 1978 and December 31, 1987, a total of 11,343 cases in 96 RTOG protocols, excluding particle studies, underwent initial review. Of this number, 2227 patients were entered in lung cancer studies and 1341 patients were entered in head/neck cancer studies. Initial review was carried out in 2089 (93.8%) of the lung cancer cases. Missing or delayed data accounted for 138 (6.2%) cases not reviewed initially. In head/neck cancer trials, 1251 (93.2%) received initial review and 90 (6.8%) did not. Our findings suggest that there are sharply defined but long lasting learning experiences involved in clinical trial participation. Consideration may be given to modifying the initial review process to use random sampling of cases accessioned by experienced investigators in ongoing clinical trials and to continuing the total case evaluation on all new studies and cases entered by inexperienced investigators or investigators/institutions with unsatisfactory performance. Recommendations regarding initial review of other sites will await evaluation of the impact of initial review on those sites.

Head and Neck Neoplasms↗

Acquired immune deficiency syndrome (AIDS). Indications for abdominal surgery, pathology, and outcome.

Thirty-six major abdominal operations were performed on 35 Acquired Immune Deficiency Syndrome (AIDS) patients (33 men, two women). Twenty-two elective operations were indicated for diagnosis of abdominal or retroperitoneal mass (6), incomplete bowel obstruction (5), intra-abdominal infection (4), biliary symptoms (3), thrombocytopenia (3), and toxic megacolon (1). Fourteen emergency operations were for perforated viscus or peritonitis (11), massive gastrointestinal bleeding (2), and cecal volvulus (1). In 5 of 22 (23%) elective operations AIDS was unknown to the treating physicians until diagnosed by the surgical pathology; in contrast, all 14 emergency operations were in patients who had a known diagnosis of AIDS. The operative findings were related to AIDS in 34 of 36 (94%) operations. Cytomegalovirus was the most common pathogen, isolated or identified microscopically in 11 patients (eight emergency and three elective operations). Mycobacterial infections presented as retroperitoneal adenopathy or splenic abscess in six patients. Non-Hodgkins lymphoma was the most common malignancy found, presenting as an abdominal mass (4), bowel obstruction (3), or with gastrointestinal bleeding (2). Kaposi's sarcoma was diagnosed at laparotomy in four patients. The 1-month operative mortality rate for elective operation was 9% (2 of 22) and 46% (6 of 13) in emergencies. Postoperative complications included 1 reoperation for sepsis caused by inadequately resected CMV colitis; 1 pancreatic fistula; 1 wound dehiscence, and 2 minor wound infections.

Abdomen↗

An abused psychotic preadolescent at risk for Huntington's disease.

An abused 10-year-old girl with a family history of Huntington's disease developed incapacitating abdominal pain with concomitant behavioral symptomatology suggestive of dementia. The pseudoneurologic nature of her symptoms was clarified through exhaustive evaluation and did not appear to be that of early-onset Huntington's disease. Assessment included pediatric, psychiatric, neurologic, and gynecologic examination; extensive radiologic and laboratory tests; and chronobiology studies. Successful treatment necessitated the integration of numerous therapeutic modalities including dynamically oriented psychotherapy, psychopharmacologic intervention, physical therapy, behavior modification, and electroconvulsive therapy.

Abdomen↗

Gonadotrophin-releasing activity of neurohypophysial hormones: I. Potential for modulation of pituitary hormone secretion in rats.

Neurohypophysial hormones have been implicated in the control of anterior pituitary function, and oxytocin has been shown to stimulate gonadotrophin excretion and ovarian follicular development in certain species. To determine the role of neurohypophysial peptides in the control of gonadotrophin release, their actions on LH and FSH secretion were analysed in rats in vivo and in vitro. In adult female rats, administration of oxytocin during early pro-oestrus advanced the spontaneous LH surge and markedly increased peripheral LH levels at 15.00 h compared with control animals. In cultured pituitary cells from adult female rats, oxytocin and vasopressin elicited dose-related increases in LH and FSH release. Such responses were not affected by a potent gonadotrophin-releasing hormone (GnRH) antagonist that abolished GnRH agonist-induced release of LH and FSH. Oxytocin did not enhance GnRH agonist-stimulated gonadotrophin release to the same extent as it increased basal secretion, but at low concentrations of GnRH agonist the effects were additive. The gonadotrophin responses to oxytocin and vasopressin were inhibited by the specific neurohypophysial hormone antagonists, [d(CH2)5D-Ile2,Ile4,Arg8]vasopressin and [d(CH2)5Tyr (Me),Arg8]vasopressin. These results provide direct evidence that neurohypophysial hormones can stimulate gonadotrophin secretion through a receptor system distinct from the GnRH receptor. Such a mechanism could represent a complementary hypothalamic control system for long-term modulation of LH and FSH secretion by exerting a basal or tonic influence on gonadotrophin production.

Animals↗

Surgery in patients with acquired immunodeficiency syndrome.

Between 1982 and 1985, 21 patients with acquired immunodeficiency syndrome (20 men and one woman; mean age, 36 years) underwent 31 surgical procedures at the Harbor/UCLA Medical Center, Torrance, or the UCLA Medical Center (skin, lymph node, and endoscopic biopsies were excluded). The operations included seven emergencies and 24 elective operations (eight major and 16 minor). Pathologic findings included cytomegalovirus colon perforation (two), disseminated Kaposi's sarcoma (KS) of the small and large bowel (one), cystic duct obstruction by KS (one), poorly differentiated gastrointestinal lymphoma (one), Candida acalculous cholecystitis (one), central nervous system toxoplasmosis (two), amebic encephalitis with abscess (one), staphylococcal botryomycosis of the pericardium (one), pulmonary KS (one), and cytomegalovirus (one). The overall operative (30 days) mortality rate was 48% (10/21). The emergency surgery rate was 57% (4/7), elective, 43% (6/14). The high operative mortality rate in these patients was usually due to progression of opportunistic infections or malignancy.

Abdomen↗