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Biomedical subjects

M Petri

Publications and source records attributed to M Petri.

At least 181 records · Page 10Linked to original sources

Glomerular alterations in experimental diabetes of the rat.

To detect structural glomerular alterations in the early stages of diabetes mellitus glomeruli from young streptozotocin diabetic rats were studied by light microscopy with morphometric methods 2, 8, 12 and 24 weeks after induction of diabetes. It was found that there is a marked increase in the percentage mesangial surface as compared with the control animals already two weeks after induction of diabetes. The relative mesangial surface fraction was greater in the diabetic animals than in the controls at all test times. It was also demonstrated that the endothelial cell count was reduced in the diabetic animals in the first few weeks of the study. High-grade glycosuria and proteinuria were likewise observed in the diabetic animals. Hence the mesangium appears to be one of the glomerular structures which shows the first changes in the initial stages of diabetes mellitus. Possibly the most likely cause of the changes based on the present study is the diabetic metabolic state (or the insulin deficiency).

Animals↗

Intravenous isosorbide dinitrate in acute left ventricular failure--a dose--response study.

The haemodynamic effects of intravenous isosorbide dinitrate (Cedocard) in patients with severe acute left ventricular failure have been assessed using incremental infusion rates from 50 to 800 micrograms min-1. For most patients most of the fall in pulmonary arterial diastolic pressure occurred by 200 micrograms min-1, with little further fall at higher doses. At 200 micrograms min-1 pulmonary arterial diastolic pressure fell from 29 to 23 mgHg (P less than 0.001), there was no significant change in cardiac index (1.9 to 2.0 L min-1 m-2) or heart rate (108 to 108 beats min-1). Despite high doses, no side effects were observed. Intravenous isosorbide dinitrate is effective and safe in the management of acute severe left ventricular failure. In most patients an infusion rate of about 200 micrograms min-1 produces optimal haemodynamic effects.

Adult↗

Occupational irritant contact folliculitis associated with triphenyl tin fluoride (TPTF) exposure.

Triphenyl tin fluoride (TPTF) is a bioactive organo-tin compound used in concentrations 2-12% as anti-foulants in boat paints. The chemical is moderately toxic to the skin. An occupational irritant contact folliculitis from TPTF in a marine paint plant worker is described. Contact allergy was excluded by patch testing. An attempt to reproduce the follicular reaction in man, rabbit and guinea pig was unsuccessful.

Animals↗

Discoid lupus erythematosus-like lesions and stomatitis in female carriers of X-linked chronic granulomatous disease.

The skin and oral mucosa were studied in an unselected series of carriers of x-linked chronic granulomatous disease, a hereditary condition in which phagocytic cells display a pronounced functional defect. Three carriers had discoid lupus erythematosus (DLE)-like skin lesions which histopathologically were consistent with DLE of the hypertrophic and profundus type. Four patients had experienced photosensitivity in childhood. Seven patients had recurrent aphthous-like stomatitis which should be distinguished from the recurrent aphthous stomatitis seen in otherwise healthy individuals. The remarkably high incidence of DLE-like symptoms in heterozygous carriers might be related to the presence of mixed populations of defective and normal phagocytes. The variable expression of skin symptoms may be related to uneven distribution of abnormal and normal phagocytes. Female patients with these clinical symptoms, especially the combination of DLE-like skin lesions and aphthous-like stomatitis, should be suspected of being carriers of chronic granulomatous disease and studies of phagocyte function in vitro should be performed, since the diagnosis of the carrier state is of utmost importance for genetic counselling before pregnancy.

Adult↗

Stereomicroscopic examination of stained rectal biopsies in ulcerative colitis and Crohn's disease.

Rectal biopsy samples from 22 healthy control subjects, 54 patients with ulcerative colitis, and 34 with Crohn's disease with involvement of the colon or rectum were investigated in a stereomicroscopic study. Samples were stained as whole mounts with Alcian Green before the stereomicroscopic examination. In ulcerative colitis, biopsies almost constantly showed changes in the mucosal surface pattern, including irregular, enlarged crypt openings filled with exudate, granulated and bulging surface, and patchy localization of the goblet cells. There was a close correlation between the stereomicroscopic findings and the clinical disease activity, the sigmoidoscopic findings, and the histologic activity. Apart from the stereomicroscopic observation of small superficial erosions in one fourth of the biopsies, no changes of diagnostic value were observed in Crohn's disease.

Adolescent↗

The paranoid syndrome.

Paranoid characteristics often prompt the diagnosis of schizophrenia. This paper advises a cautious diagnostic approach aimed at increased awareness of the many and potentially serious illnesses that may present with paranoid features.

Affective Symptoms↗

The atypical psychoses.

The psychiatric literature contains numerous accounts of psychoses found worldwide that do not fit classic definitions of schizophrenia, manic-depression, or organic brain syndrome. These vaguely defined 'atypical psychoses' are under scrutiny because of growing knowledge and more rigorous methodology in descriptive and cross-cultural psychiatry. The authors trace the history of atypical psychosis concepts from the contributions of Kraepelin, Jaspers, and Freud to contemporary European and Anglo-American viewpoints. Studies of the atypical psychoses are reviewed in the light of current validation methods in psychiatry. Several methodologic problems plague this area: inadequate definitions, etiologic prejudice, poor premorbid and follow-up assessment, as well as certain naive notions about psychopathology in different cultures. Consequently, knowledge of atypical psychosis is limited and largely impractical. The authors suggest several possibilities for interpreting present and future evidence about these disorders and certain strategies for future studies.

Attitude of Health Personnel↗

Effects of prolonged vasopressin treatment in Brattleboro rats with diabetes insipidus.

Normal Long-Evans rats (LE) exhibited diurnal variations of plasma arginine vasopressin (AVP) concentrations with peak values at 10 A.M. and minimum values at 1 P.M. Brattleboro rats heterozygous for hypothalamic diabetes insipidus (DI) had significantly reduced plasma AVP concentrations and increased plasma osmolalities when compared with LE rats. By prolonged injection of 100 mU/day of vasopressin tannate (VPT) into Brattleboro rats homozygous for DI, plasma AVP concentrations close to those of LE rats were achieved. Potassium was retained for 7 days until escape of vasopressin-induced potassium retention occurred. When 500 mU VPT were injected into DI rats, high plasma AVP levels were induced. Potassium was retained for 2-3 days. After initial sodium retention, periods of natriuresis occurred. During treatment with 100 mU VPT/day most of the alterations present in DI rats were corrected, which included increased water turnover and external water loss, increased hematocrit and plasma sodium concentrations (but not increased plasma osmolalities), hypokalemia, increased activity of the renin-angiotensin system, and reduced adrenocortical function.

Adrenal Glands↗

Plasma vasopressin concentrations and effects of vasopressin antiserum on blood pressure in rats with malignant two-kidney Goldblatt hypertension.

Male Sprague-Dawley rats with unilateral renal artery stenosis and a contralateral untouched kidney develop a malignant hypertension (MH) which is characterized by high blood pressures, sodium and water depletion, and subsequent activation of the renin-angiotensin system. In the present studies we found plasma arginine vasopressin (AVP) concentrations-3-fold higher than those in rats with benign renal hypertension, and 4- to 5-fold higher than those in normotensive control rats. Analysis of individual values showed considerable scatter; about 50% of the values fell in the range of benign hypertensive or control rats. When a specific AVP antiserum was injected, iv, into eight conscious unrestrained MH rats, BP transiently fell toward control values in four; in one, BP fell by only 10 mm Hg, and three other MH rats showed no response. In the same rats, injection of a specific angiotensin II antiserum always induced a transient fall in BP. On the basis of these and previously reported observations, we conclude that, subsequent to sodium and water loss and activation of the renin-angiotensin system, vasopressin release is stimulated in a significant number of MH rats and that, in these rats, vasopressin may cause significant systemic vasoconstriction. Thereby vasopressin may contribute to the development of malignant renal hypertension in rats.

Animals↗

Stereomicroscopic examination of stained rectal biopsies.

The normal mucosal surface morphology in the rectum has been described by investigation of 15 rectal biopsies using a semimacroscopic technique. The structures of the mucosal surface were rendered visible by staining the biopsies as whole mounts with Alcian Green. A regular pattern of the crypt openings was found, and the goblet cells were observed in and just around the crypt openings. The density of crypt openings was calculated as the number of crypt openings per square millimetre (104 +/- 23 openings per mm2, mean and S.D.). Histologic examinations of the same biopsies were performed, and the density of crypt tubules was calculated from serial, horizontal sections (130 +/- 34 tubules per mm2, mean and S.D.). The ratio of crypt openings/crypt tubules was 1:1.25, indicating some branching of the mucosal glands in the rectum.

Biopsy↗

Vasopressor role of ADH in the pathogenesis of malignant DOC hypertension.

During the onset of malignant hypertension (MH) in rats treated with deoxycorticosterone trimethylacetate (DOC), plasma arginine vasopressin (AVP) concentrations increase tenfold as a consequence of hypovolemia and hyperosmolality. In benign hypertensive (BH) rats, plasma AVP is increased threefold in comparison with control animals. Plasma renin is markedly suppressed in both BH and MH animals. In MH rats, biologically active AVP antiserum lowers blood pressure (BP) transiently to normal or subnormal levels; in BH rats, a small BP-lowering effect of the AVP antiserum is seen. (Biologically active angiotensin II antiserum does not lower BP in MH rats.) The relationship between the height of BP and plasma AVP concentration in DOC hypertensive rats indicates, when compared with that relationship in diabetes insipidus rats infused with AVP, a marked enhancement of the vasopressor effect of AVP. These findings and the earlier observation of vasopressin-induced vascular damage by Byrom (F. B. Byrom, The Hypertensive Vascular Crisis. London: Heinemann, 1969) strongly suggest that ADH is involved as a vasopressor hormone in the pathogenesis of malignant DOC hypertension.

Angiotensin II↗

Comparative study on development of corticosterone and DOCA hypertension in rats.

The administration of corticosterone for 5 consecutive days to normal rats on a standard sodium intake induced negative sodium and water balance. These effects were opposite those observed under DOCA treatment. However, not only under DOCA but also under corticosterone treatment extracellular fluid volume (ECFV) and plasma volume (PV) increased, and blood pressure (BP) rose in parallel. Plasma renin and angiotensin II concentrations declined under the influence of both steroids. Plasma arginine vasopressin concentrations increased under DOCA, whereas they transiently decreased under corticosterone administration. These data suggest that the common mediator for BP elevation due to steroid excess would be an increase in ECFV and PV. The pathways by which this increase is achieved seem to be different. Under DOCA treatment ECFV and PV increased subsequent to renal sodium and water retention. Under corticosterone, however, sodium and water were shifted from intra- to extracellular compartments, and a fraction of this shifted sodium and water was conserved in extracellular space, most likely because corticosterone also affected renal sodium handling.

Animals↗