RESUMEN
We investigated the effects of the phospholipase A(2) (PLA(2)) activators calcium ionophore A 23187, hydrogen peroxide (H(2)O(2)), bradykinin (BK), histamine and noradrenaline (NA) on the 8-iso-prostaglandin (PG)F(2alpha) formation in the isolated human umbilical vein and the isolated rabbit ear. For comparison, the influence of these substances on the thromboxane A(2) (TXA(2)) release was also investigated. The release of total (esterified as well as free) 8-iso-PGF(2alpha), free 8-iso-PGF(2alpha) and TXB(2), the stable metabolite of TXA(2), was determined by specific enzyme immunoassays. The results show that bolus injections of 5.4 mmol H(2)O(2), 30 nmol A 23187, 10 nmol BK, 50 nmol histamine and 20 nmol NA caused an increased release of total 8-iso-PGF(2alpha) in the umbilical vein and the rabbit ear. A perfusion with H(2)O(2) at a final concentration of 0.3 mM also increased the release of this isoprostane. Increased formation of free 8-iso-PGF(2alpha) was induced by A 23187 injection and by both modes of H(2)O(2) administration, but not by the other treatments. Bolus injections of A 23187, BK and histamine induced an increased release of TXB(2) in both organs. Both modes of H(2)O(2) administration and NA showed no releasing effects. In conclusion, our results show that the substances used are able to stimulate the formation of 8-iso-PGF(2alpha) concurrently with the release of PGs. This effect might be of pathophysiological relevance in inflammatory and cardiovascular diseases in which an enhanced release of free radicals, BK, histamine or NA play an important role.
Asunto(s)
Dinoprost/análogos & derivados , Fosfolipasas A/fisiología , Tromboxano A2/biosíntesis , Venas Umbilicales/metabolismo , Animales , Bradiquinina/farmacología , Calcimicina/farmacología , Dinoprost/biosíntesis , F2-Isoprostanos , Femenino , Histamina/farmacología , Humanos , Peróxido de Hidrógeno/farmacología , Masculino , Norepinefrina/farmacología , Perfusión , ConejosRESUMEN
No microbial data are available for rural tropical areas. Yet most people in Africa live in rural areas where the burdens of infectious diseases remain the primary cause for morbidity and mortality. A pilot study was done by culturing midstream urine from patient with dysuria (100 with Gram-negative fermentative rods), blood from patients with FUO (55/307 positive) and swabs from patients with infected wounds (29 with Staphylococcus aureus). Bacteria were identified and susceptibility tests were performed according to protocols. Klebsiella was the most common isolate from urine (48%). The overall resistance in urine isolates for ampicillin was 76% and for cotrimoxazole, 60%. The main isolates from blood were Klebsiella Enterobacter sp (21/55) and Salmonella (14/55) in patients from agricultural areas, and Staphylococcus aureus (12/55) in patients from desert areas. The Staphylococcus aureus from wounds were all penicillin resistant and 9/29 were cloxacillin resistant. Influence of the environment, underlying pathology and previous use of antibiotics give unexpected predominance of Klebsiella and high resistance in all isolates. Large scale surveillance studies are needed so that prescription of antibiotics can be based on locally obtained data.