Regional haemodynamic effects of urocortin in the anaesthetized rat

Urocortin is an endogenous vasodilator peptide that is related to corticotrophin-releasing factor. We examined the haemodynamic effects of urocortin in thiobutabarbital-anaesthetized rats, via the triple-isotope microspheres technique. Urocortin (3 nmol/kg, i.v. bolus) reduced mean arterial pressure (-25 mm Hg) through a decrease in total peripheral resistance (-43%). This was associated with an increase in cardiac output (+24%) and vasodilatation of the following tissues: heart and stomach (approximately 300% of baseline); liver, intestine, caecum/colon, skeletal muscle and skin (approximately 200%); and testes (approximately 150%). Arterial conductances of the kidneys, spleen and brain were unaffected by urocortin. Neither the vehicle (0.9% NaCl) nor a low dose of urocortin (0.3 nmol/kg) altered any measurements. Therefore, urocortin causes generalized vasodilatation as follows: heart and stomach>liver, intestine, caecum/colon, skeletal muscle and skin>testes.     

Synthesis and antimicrobial activity of some new 2-indolinone derived oximes and spiro-isoxazolines

The synthesis and spectral analysis of some new 1,3-dihydro-3-hydroxy-3-[2-hydroxyimino-2-(substituted phenyl)ethyl]-2H-indol-2-ones (21-32) and spiro[3H-indol-3,5'-(4'H)-isoxazol]-2(1H)-ones (33-44) are described. Sixteen of the synthesized compounds were screened in vitro for their growth inhibitory activity against thirteen species of microorganisms, viz, S. aureus, S. epidermidis, S. faecalis, B. subtilis, B. cereus, E. aerogens, E. coli, P. aeruginosa, P. vulgaris, A. baumonia, A. faecalis, C. albicans and S. cervicae. Most of the compounds exhibited significant antimicrobial activity especially the oximes 28 and 29.     

Extruded and protruded lumbar discs: combined clinical, histopathological, histochemical, immunopathological, histochemical, immunopathological and ultrastructural studies.

A total number of selected 252 patients with prolapsed lumbar intervertebral discs (92 extruded and 160 protruded) were operated upon in Neurosurgery Department Zagazig University Hospital during the period extended from January, 1988, to October 1990. In this study we reviewed their clinical and operative data. Surgical biopsies were taken from randomly selected 120 patients of them (50 extruded and 70 protruded discs) and were subjected to histopathological, histochemical and immunopathological studies. Ultrastructural study was performed for randomly selected 14 cases (7 extruded and 7 protruded discs). The results were compared with 7 normal intervertebral discs obtained from these studies showed that there were no differences between extruded and protruded discs at the histochemical level. Cell mediated immunity could be added as a factor in the pathogenesis of the degenerative process that lead to disc prolapse (in 20% of cases with extruded discs and 57.1% of cases with protruded discs). At the ultrastructural level 85.3% of extruded discs were prolapsed nucleus pulposus while 14.7% were prolapsed annulus fibrosus alone or with nucleus pulposus. All protruded discs were prolapsed annulus fibrosus with nucleus pulposus. These findings may have an impact on the management of this common problem.     

Seasonal changes in plasma levels of gonadal steroids of sea bass, Dicentrarchus labrax L

Levels of plasma testosterone (T) and 11-ketotestosterone (11-KT) in males and plasma 17 beta-estradiol (E2), 17 alpha-20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-diOH-P), and T in females were assayed by radioimmunoassay at monthly intervals throughout the sexual cycle of sea bass (Dicentrarchus labrax L.). 17 alpha,20 beta-DiOH-P was maintained at low levels (below 1 ng/ml) throughout the year, even during the spawning period (January-March). A bimodal seasonal pattern of plasma testosterone was observed. Plasma T and E2 levels became significantly increased in December (advanced gametogenesis period) and then showed further increases during January and February (first half of the spawning period) in parallel with the growth of the vitellogenic oocytes. Multiple spawnings of individual females were also observed during the spawning period affecting the relative fecundity of the eggs. A possible role of E2 on this behavior is discussed. In males, both plasma T and 11-KT initially increased in November and then showed further increasings during the rest of the period of gametogenesis (December) to reach their peak levels in the first half of the spawning period (end of January). These increased and sustained higher levels of plasma steroids coincided with the presence of spermiating males. A second peak of plasma testosterone appeared at the end of the postspawning period-beginning of the pregametogenesis period (May-June) both in males and females and their possible role with the preparation of the gonad for the next reproductive cycle is discussed.     

Cholinergic mechanisms involved in release and effect of prostaglandin E2 in HCl-stimulated duodenal HCO-3 secretion in the conscious rat

Using a proximal duodenal loop in conscious rats, we investigated interactions between prostaglandin E2 and nicotinic and muscarinic receptor mechanisms previously found to be involved in the duodenal HCO3- response to HCl. In previous studies using the same model, a 5-min perfusion of the duodenal loop with 150 mmol l-1 HCl produced a marked and sustained HCO3- response. In the present study, the identical challenge produced a rapid 20-fold increase in the luminal output of prostaglandin E2 during acid exposure, followed by a sustained more than twofold elevation above the basal level during the 45 min monitored. The prostaglandin synthesis inhibitor indomethacin (4 mg kg-1 i.p.) suppressed the output of prostaglandin E2 during the HCl challenge from 131 +/- 84 to 15.4 +/- 10.0 pmol cm-1 h-1, and in the post-stimulatory period from 17.3 +/- 9.1 to 4.4 +/- 2.2 pmol cm-1 h-1. The nicotinic receptor antagonist hexamethonium (20 mg kg-1 i.v.) had no effect on the output of prostaglandin E2. The muscarinic receptor antagonist atropine (0.5 mg kg-1 s.c.) had no effect on the output of prostaglandin E2 during HCl challenge, but reduced the post-stimulatory output to 7.7 +/- 4.1 pmol cm-1 h-1. Perfusion of the duodenal loop with 0.1 mmol l-1 prostaglandin E2 produced a HCO3- response that was abolished by hexamethonium (20 mg kg-1 i.v.), but not affected by atropine (0.5 mg kg-1 s.c.).(ABSTRACT TRUNCATED AT 250 WORDS)     

Hypercalcaemia: a clue to Mycobacterium avium intracellulare infection in a patient with AIDS

Hypercalcaemia is uncommon in HIV-infected patients and should suggest a different priority for differential diagnosis than would be considered in other settings. Although hypercalcaemia has long been associated with granulomatous diseases including tuberculosis, it has only recently been recognised that patients with illness due to Mycobacterium avium intracellulare (MAI) may develop it. We report a patient with AIDS in whom unexplained hypercalcaemia was the harbinger of clinically significant MAI infection. Patients with AIDS who develop hypercalcaemia should be closely evaluated for underlying MAI infection.     

A Model of the Kinetics of Insulin in Man

The design of the present study of the kinetics of insulin in man combines experimental features which obviate two of the major problems in previous insulin studies. (a) The use of radioiodinated insulin as a tracer has been shown to be inappropriate since its metabolism differs markedly from that of the native hormone. Therefore porcine insulin was administered by procedures which raised insulin levels in arterial plasma into the upper physiologic range. Hypoglycemia was prevented by adjusting the rate of an intravenous infusion of glucose in order to control the blood glucose concentration (the glucose-clamp technique). (b) Estimation of a single biological half-time of insulin after pulse injection of the hormone has been shown to be inappropriate since plasma insulin disappearance curves are multiexponential. Therefore the SAAM 25 computer program was used in order to define the parameters of a three compartment insulin model.The combined insulin mass of the three compartments (expressed as plasma equivalent volume) is equal to inulin space (15.7% body wt). Compartment 1 is apparently the plasma space (4.5%). The other two compartments are extra-vascular; compartment 2 is small (1.7%) and equilibrates rapidly with plasma, and compartment 3 is large (9.5%) and equilibrates slowly with plasma.The SAAM 25 program can simulate the buildup and decay of insulin in compartments 2 and 3 which cannot be assayed directly. Insulin in compartment 3 was found to correlate remarkably with the time-course of the servo-controlled glucose infusion. Under conditions of a steady-state arterial glucose level, glucose infusion is a measure of glucose utilization. We conclude that compartment 3 insulin (rather than plasma insulin) is a more direct determinant of glucose utilization.We suggest that the combined use of glucose-clamp and kinetic-modeling techniques should aid in the delineation of pathophysiologic states affecting glucose and insulin metabolism.