Pleomorphic xanthoastrocytoma. Immunohistochemical methods for differentiation from fibrous histiocytomas with similar morphology

Three cases of primary intracranial tumours fulfilling the clinical and histological criteria of pleomorphic xanthoastrocytoma are presented. As is typical, they occurred in young people, aged 15, 17, and 22 years, and were composed of lipid-laden pleomorphic cells with frequent bizarre multinucleated forms and a prominent reticulin network. However, subsequent immunohistochemistry, further histological review, and clinical follow-up suggest that these tumours were different entities. In one case the tumour cells were negative for GFAP but positive with a panel of histiocytic markers. The lesion, which extended rapidly and caused death within 6 months, was assumed to be a true meningeal fibrous histiocytoma. The remaining two cases were positive for glial fibrillary acidic protein (GFAP) and S100 protein. One of these was mitotically active, contained areas of necrosis and vascular proliferation, and also led rapidly to death. This, we concluded, was a glioblastoma. The third case showed little mitotic activity and the patient remains well; this is probably a true pleomorphic xanthoastrocytoma. These results indicate that tumours with light-microscopic appearance of pleomorphic xanthoastrocytoma require detailed immunohistochemical investigation. Only those lesions with low mitotic activity and undoubted evidence of glial origin should be accepted as true pleomorphic xanthoastrocytoma. Extensive necrosis in a tumour with GFAP-positive, lipid-rich cells indicates a lipidised glioblastoma, while positive histiocytic immunocytochemistry should suggest a fibrous histiocytoma.

Perforation of a jejunal adenocarcinoma complicating coeliac disease

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Preliminary report on use of depot formulation of LHRH analogue ICI 118630 (Zoladex) in patients with prostatic cancer

A study was conducted of the response of the pituitary-testicular axis to two different methods of administration of the luteinising hormone releasing hormone (LHRH) analogue ICI 118630 (Zoladex) in patients with prostatic cancer. The analogue was given by continuous infusion to four previously untreated patients with prostatic cancer for 60 days (group 1). Subsequently a further four patients were given a depot formulation of the same analogue by subcutaneous injection once every 28 days (group 2). Both methods of administration produced similar, successful suppression of luteinising hormone (LH) associated with a reduction of testosterone to castrate concentrations. The median basal testosterone concentrations before treatment in groups 1 and 2 were 20.6 and 14.1 nmol/l (5.94 and 4.07 ng/ml) respectively; these were reduced to 1.4 and 1.1 nmol/l (0.40 and 0.32 ng/ml) within four weeks of the start of treatment. The median basal LH concentration in groups 1 and 2 were 7.9 and 16.6 IU/1 respectively, which were suppressed to 2.6 and 2.4 IU/1 by four weeks. The suppression of LH and testosterone was maintained with continuous subcutaneous infusion for up to 60 days in group 1, and by subsequent injections of the depot every 28 days in group 2. The use of depot preparation of an LHRH analogue to suppress gonadotrophin and sex hormone secretion offers the convenience of once monthly injections when LHRH analogues are required for the long term treatment of elderly patients with prostatic cancer and children with precocious puberty.

Governing equations of motion for the otolith organs and their response to a step change in velocity of the skull

The otolith organs are the linear motion sensors of the inner ear. They comprise an overdamped second-order system and respond to gravity and skull acceleration. The governing equations of motion which describe the relative displacement of the mass with respect to the skull are developed. When these equations are non-dimensionalized they indicate that the elastic term is almost negligible with respect to the viscous and inertial terms. For a step change in skull velocity an analytic solution is given for the elastic term equal to zero and numeric solutions are given for small values of the elastic term.

Peptide inhibitors of renin

Analogues of renin substrate that incorporated a non-cleavable isostere at the scissile bond are powerful inhibitors of renin both in vitro, and in animals and man.

Neonatal tetanus: mode of infection, prevalence, and prevention in southern Sudan

Neonatal tetanus affects 1 in every 82 and kills 1 in every 110 infants born in the town of Juba, southern Sudan. It is also an important cause of death in adult life both in southern Sudan and in many other regions of the developing world. One vehicle of infection could be the fine string-like roots used to tie the cord. To prevent neonatal tetanus governments and aid-giving agencies should distribute to women and midwives kits containing a sterile blade, a sterile ligature, two or three sterile adhesive dressings for the umbilical stump, and two or three sterile swabs.

Intracranial infection due to mycobacterium bovis in Hodgkin's disease

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Hemolyzed blood and serum levels of delta 9-THC: effects on the performance of roadside sobriety tests

A pilot study was conducted to ascertain the range of induced hemolyzed blood/serum delta 9-tetrahydrocannabinol (delta 9-THC) concentrations in 58 human subjects. Subjects were tested within 5 min of smoking a delta 9-THC cigarette and then at half-hour intervals to 150 min. The subjects initially demonstrated a broad range of delta 9-THC hemolyzed blood levels, which settled within an hour to levels comparable to those measured in California drivers who had been stopped for impaired driving, arrested, and tested for delta 9-THC. Serum levels, when correlated with performance or roadside sobriety tests, demonstrated a broad range (5 to 183 ng/mL) of delta 9-THC levels and an "adaptation" effect in the subjects' perception of their own impairment. Although this preliminary study was not a double-blind placebo experiment, the overall performance of human subjects demonstrated the "adaptation" effect, which may be a significant factor in making judgments while performing such complex tasks as driving. Also, the effects of the drug extended beyond the period of elevated delta 9-THC blood levels, perhaps because of THC metabolites that may contribute to impairment or the persistence of THC in the central nervous system. This pilot study will lay the groundwork for a program designed to determine the epidemiology and behavior correlates of marijuana use in motorists.

H-77: a potent new renin inhibitor. In vitro and in vivo studies

Chemical modification of the backbone at the cleavage site in the (6-13)-octapeptide of equine angiotensinogen resulted in greatly increased binding affinity and resistance to cleavage by renin. The D-His6-Tyr13 octapeptide analog containing the reduced bond -CH2-NH-instead of a peptide bond -CO-NH- at the Leu10-Leu11 linkage (H-77) was a powerful in vitro inhibitor of canine renin (IC50 = 24nM). It gave an IC50 of 1 microM against human renin and 0.6 microM against rat renin. In sodium-depleted conscious dogs, infusion of H-77 caused dose-related falls of plasma angiotensin I plasma angiotensin II concentration and mean arterial pressure; the minimum effective dose was 0.1 mg . kg-1 hr-1. Similar infusions of H-77 in chronically catheterized rats have no effect on blood pressure or plasma angiotensin II concentration. Thus, the in vitro effect of H-77 as an inhibitor of renin in dog, human, and rat plasma was paralleled by its action in the whole animal.

Anterior cruciate: methods of physical examination

Tear of the anterior cruciate ligament is a common, serious injury. Since the long-range consequences of uncorrected anterior cruciate incompetence are better understood, and surgical and rehabilitative measures improved, early accurate diagnosis is increasingly important. Besides a careful history, diagnosis requires the use of specific physical examination methods to reproduce the symptomatic subluxation (anterior shift or internal rotation) and to assess functional performance of the knee.

Immunoglobulin localization in benign and malignant lesions of the human mammary gland

Using direct imunofluorescence, lesions from 266 human breast specimens were studied for the presence of IgA, IgM, or IgG localization. The lesions included benign elements from 66 subcutaneous mastectomy specimens in which the absence of simultaneous breast malignancy was documented, primary breast carcinomas from 153 mastectomy specimens, and 47 biopsies containing metastatic breast cancer. A statistically significant association of IgA and IgM with benign lesions was contrasted to the association of IgG with malignant lesions. In both primary and metastatic lesions, IgG localization was associated with estrogen-receptor-poor primary cancers as compared with estrogen-receptor-rich primary cancers. Among primary breast cancer patients, IgG localization in the tumor correlated with relative lymphopenia. A shorter disease-free interval was noted in association with IgG localization among the metastatic breast lesions. No statistically significant association between stage of disease and immunoglobulin presence was demonstrable. Moderate-to-severe intraductal epithelial hyperplasias were more often associated with immunoglobulin G localization that were other benign lesions.

Encystment Discovered in a Marine Copepod

It has been believed that marine crustacea do not encyst as adults. The benthic copepod Heteropsyllus nunni has been found to encyst in intertidal sands in the summer; free-living forms are abundant in the winter. A unique platelike structure on the cephalothorax is thought to be the site of cyst formation.

Bacterial contamination of telephones in an intensive care unit

Pathogenic and potentially pathogenic bacteria were found on telephones of an intensive care unit. Direct contamination by microorganisms from throats, hands, and noses of the staff members is real although airborne contamination would also play a role. The awareness of environmental risk in intensive care units is underlined.