Stress-induced changes in cholecystokinin and substance P concentrations in discrete regions of the rat hypothalamus

The effects of acute stress exposure upon cholecystokinin (CCK) and substance P (SP) concentrations in discrete hypothalamic regions of the adult male rat brain were studied. Animals were exposed to foot shock stress for periods of 2, 4, 10, 30 or 60 min duration; immediately afterwards they were decapitated; brains were frozen and subsequently microdissected. CCK and SP concentrations were assayed by a specific RIA, as were serum levels of ACTH, corticosterone, PRL, GH, LH and testosterone. Stress had no effect upon SP concentrations in the anterior or posterior parts of the arcuate nucleus (ARC), but led to elevated CCK levels in the posterior ARC following 60 min of exposure. In both the ventromedial and dorsomedial hypothalamic areas, stress induced depletions of both neuropeptides. In the anterior (but not the posterior) portions of the lateral hypothalamic area, CCK and SP concentrations were reduced by stress exposure. These studies demonstrate that discrete hypothalamic CCK and SP neuronal systems are responsive to stress. This suggests that endogenous hypothalamic CCK and SP participate, along with other neurotransmitters/neuromodulators, in the integrated hypothalamic stress response, and mediate stress-neuroendocrine interactions.     

Activating effect of substance P on nerve tissue in culture

The effect of substance P on organotypic culture of rat sympathetic ganglia and spinal cord was studied. Substance P was able to stimulate the fibre outgrowth from explant, to increase the numbers of glial and fibroblasttypic cells in ganglia growth zone. The effect was observed in the range from 10(-5) to 10(-12) M (for sympathetic ganglia) and from 10(-5) to 10(-14) M (for spinal cord culture). It is suggested that substance P can be used as a nonspecific growth factor for peripheral and central nervous tissue.     

Ideological framework and health development in Tanzania 1961-2000

At independence in 1961, Tanzania inherited a classic economic structure from Britain. The most immediate aims of the new government included replacing the colonial administration with trained nationals, radical change of the development philosophy and strategies and development of self-reliance in all development sectors. The Arusha Declaration of 1967 was the turning point in Tanzania and achievements in all the sectors can be measured against targets established soon after. This paper examines development in the health sector within the wider national framework.     

Renal vascular reactivity in jaundice

Obstructive jaundice is associated with a predisposition to hypotension and acute renal failure that may be related to changes in renovascular responsiveness, particularly to norepinephrine (NE). This study was undertaken to investigate changes in vascular response to NE and to determine how these changes are related to prostaglandins. Kidneys from bile duct-ligated (BDL) rabbits (n = 5) were perfused with Krebs' solution at 7.65 ml/min, and the response to varying boluses of NE (0.78 to 6.24 micrograms) was measured as changes in perfusion pressure. When compared with sham-operated control kidneys (n = 8), a significantly blunted response was seen at all doses tested. The NE response was further assessed by measuring force development in mounted segments of main renal arteries (MRAs) (n = 8) and interlobar arteries (ILAs) (n = 6) from BDL rabbits and sham-operated controls (MRA, n = 8; ILA, n = 6). The dose-response curves were significantly depressed in both MRAs and ILAs from BDL animals. In addition, MRAs from sham-operated control animals exhibited decreased response to NE after incubation for 1 hour in jaundiced serum. This attenuated response of MRAs to NE was prevented when indomethacin (5 mg/kg) was given to BDL rabbits before death (n = 9) or when 10(-6)mol/L of indomethacin was added to jaundiced serum during incubation (n = 6). These results indicate that obstructive jaundice induces a decreased vascular contractile response in rabbits to NE and that this effect is mediated by prostaglandins.     

Non-invasive temperature imaging of muscles with magnetic resonance imaging using spin-echo sequences

The application of spin-echo magnetic resonance imaging sequences on non-invasive temperature imaging for temperature mapping of human limbs is investigated. In an in vitro expriment performed on a meat sample, the equilibrium magnetisation P and the spin-lattice relaxation time T₁ are calculated from the values for the repetition time TR and the signal intensities obtained by a spin-echo sequence at different tissue temperatures tures as measured by a fibre-optic probe. T₁ is linearly correlated to the tissue temperature, and P is linearly correlated to the reciprocal value of the absolute temperature. Both effects, taken together, lead to a non-linear dependency of the signal intensity on temperature. Therefore a TR leading to maximum temperature dependency of the signal intensity is calculated and used in the futher experiments. In the in vivo experiments, the lower legs of two volunteers are cooled from outside. Images are acquired with a spin-echo sequence (1.5T, TR=1200 ms, TE=10 ms). A rise in signal intensity in the muscle with falling skin temperature is observed, particularly in more peripheral muscle layers. This study shows that spin-echo sequences can be used to monitor temperature changes and temperature differences in living muscle tissue.     

Direct cadiac electorphysiologic effects of sufentanil and vecuronium in isolated guinea-pig hearts

Sufentanil and vecuronium are commonly used simultaneously in anaesthesia. Bradycardia and asystole have been described immediately after the administration of these two compounds. Therefore, the purpose of the present study was to evaluate the direct cardiac effects of sufentanil and vecuronium in all parts of the cardiac pacemaker and conduction system.
The electrophysiological effects of sufentanil and vecuronium were studied in isolated spontaneously beating guinea-pig hearts perfused by the method of Langendorff. At a concentration of 0.1 μmol/1 sufentanil a significant reduction of the spontaneous sinus rate, prolongation of atrioventricular, intraventricular and His' bundle conduction could be observed. The highest concentration of 10 μmol/1 of sufentanil led to an overall slowing of conduction velocity and to an profound slowing of spontaneous sinus rate. AV nodal as well as atrial and ventricular refractoriness were markedly prolonged at this high concentration of sufentanil. In contrast, during perfusion with vecuronium at a concentration of 0.1 μmol/1 up to 10 μmol/1 no significant effects on cardiac conduction and pacemaker activity could be observed.
In conclusion, the electrophysiological effects of sufentanil are comparable to that of unspecific calcium antagonists. Therefore, especially in patients with a preexisting damage of the cardiac conduction system, the indirect effect of the combination of sufentanil and vecuronium which is predominantly responsible for bradycardia and asystole may be worsened by the direct effects of sufentanil.     

Tamoxifen and kallikrein in therapy of oligoasthenozoospermia: results of a randomized study

Because of the good results achieved with tamoxifen in the treatment of oligozoospermia and with kallikrein in the treatment of asthenozoospermia, a randomized study of the combined treatment of oligoasthenozoospermia suggested itself. 67 patients with idiopathic normogonadotropic oligoasthenozoospermia were treated with 30 mg tamoxifen/day (n = 33) or with 30 mg tamoxifen/day and additionally 600 IU kallikrein/day (n = 34). It was shown that, apart from a significant increase in sperm density in both groups, the combination therapy also resulted in an overall significant increase (p less than 0.02) in sperm motility. Sperm morphology and the swell test remained unaffected. After 3 months of therapy, 4 pregnancies occurred in each group. In ejaculates with a sperm density of less than 10 million/ml not even one sperm parameter was significantly affected in any of the groups, while with an initial value of more than 10 million/ml the increase in motility was more significant (p less than 0.008) in the group with additional kallikrein therapy (n = 18). In the monotherapy group, no significant therapeutic effect on sperm motility was seen even in patients with a sperm density of more than 10 million. The combination of tamoxifen and kallikrein therefore seems to constitute an improvement of the systemic therapy of male subfertility in patients with moderately severe oligoasthenozoospermia.