Increased cortical cell loss and prolonged hemodynamic depression after traumatic brain injury in mice lacking the IP receptor for prostacyclin.

Prostacyclin is the major arachidonic acid metabolite of the vascular endothelium and is produced mainly via the cyclooxygenase-2 pathway. By acting on the prostacyclin (IP) receptor on platelets and vascular smooth muscle cells, prostacyclin exerts vasodilatory and antiaggregative/antiadhesive effects. Previous studies have shown that prostacyclin production increases after brain trauma, but the importance of prostacyclin for posttraumatic hemodynamic alterations and neuron survival has not been investigated. This study evaluated if endogenous prostacyclin plays a role in the pathophysiologic process in the brain after brain trauma. This was performed by comparing prostacyclin (IP) receptor-deficient (IP(-/-)) mice and mice with functional IP receptor (IP(+/+)) after a controlled cortical injury regarding contusion volume, cerebral blood flow ([(14)C]iodoantipyrine autoradiography), number of perfused capillaries (fluorescein isothiocyanate-dextran fluorescence technique), the transfer constant (K(i)) for [(51)Cr]EDTA, and brain water content (wet vs dry weight) in the injured and contralateral cortex. Contusion volume was increased in IP(-/-) mice compared with IP(+/+) mice. Three hours after trauma, cortical blood flow was decreased in the injured cortex of both groups and the reduction in blood flow in the cortex of the IP(-/-) mice persisted from 3 to 24 h, whereas blood flow approached normal values in the IP(+/+) mice after 24 h. No differences could be detected between the two genotypes regarding other hemodynamic parameters. We conclude that the prostacyclin IP receptor is beneficial for neuron survival after brain trauma in mice, an effect that may be mediated by improved cortical perfusion.     

Über einige seltene Mißbildungen

Zusammenfassung Wenn wir die Ergebnisse der Untersuchung der ersten 4 Fälle überblicken, so können wir bei jeder dieser Mißbildungen, ohne diese in eine vorgefaßte Meinung einpressen zu wollen, feststellen, daß alle durch eine irgendwie gearteteäußere Ursache hervorgerufen wurden. Damit schließen wir uns der Meinung aller jener an, die die Ursachen derEntslehung dieser Mißbildungen in Behinderung des Wachstums durch Druck, Zug oder dergleichen sehen undnicht in endogenen Ursachen; dies würde unseres Erachtens ein Verzicht bedeuten.Die nächsten beiden Fälle gehören in das Kapitel der Akardie, von denen der eine eineembryonale Turmschädelbildung aufweist.Der letzte Fall stellt einePhokomelie, mit Fehlen des Unterarmes und zweier Phalangen, sowie den dazugehörigen Handwurzel- und Mittelhandknochen dar.Mit 9 Abbildungen im Text.     

The role of glucocorticoids in the cardiovascular adaptation to sodium restriction in the rat

The role of glucocorticoids (Gs) in the regulation of blood pressure has been examined using an antiglucocorticoid, RU 486, at a dose of 20 mg.kg-1 day-1 X 5 days, in male Wistar rats on a low sodium diet. In unanesthetized and chronically catheterized rats, RU 486 administration decreases mean blood pressure (MBP) by approximately 14 mmHg, without altering growth rate or urinary sodium excretion. Corticosterone administration (1 mg.kg-1 day-1) restores MBP nearly to basal level. Glomerular filtration rate evaluated from inulin clearance is unchanged whereas PAH clearance increases and filtration fraction decreases slightly. In anesthetized rats, RU 486 pretreatment decreases MBP, increases cardiac output (radiolabelled microsphere method), and depresses total and renal vascular resistance. In conclusion, endogenous Gs contribute to blood pressure control in salt-restricted rats, possibly by increasing vascular reactivity to catecholamines and angiotensin.     

Osteoid osteoma of the cervical spine

Summary The authors studied the usefulness of MR imaging in the diagnosis of an osteoid osteoma occuring within the C4 left uncinate process. It was detected by scintigraphy and diagnosed by CT. On T2-weighted MR images the nidus showed a very low signal intensity with an increased signal within the adjacent end-plates. This pattern was misleading and more suggestive of degenerative disk disease.     

Prevalence of urinary tract infection in homosexual and heterosexual men.

Homosexual practices might be expected to result in an increase in urinary tract infection in adult men. Midstream urine specimens were collected from 200 homosexual and 205 heterosexual men attending a clinic for sexually transmitted diseases. Three specimens from each group yielded more than 10(5) Escherichia coli per ml. The prevalence of urinary tract infection among homosexuals was therefore similar to that in the heterosexual population.     

Is there a need for state health department sanitary codes for public hydrotherapy and swimming pools?

The Board of Health of the Commonwealth of Virginia has an outdated sanitary code for its public hydrotherapy and swimming pools. The code is restricted to pools in hotels and other lodging places. The absence of modern regulations for public hydrotherapy and swimming pools has permitted serious deficiencies in pool maintenance, which are highlighted in this report. The most notable of these deficiencies was the presence of high levels of bacterial contamination that could predispose to infect in the water of one public hot tub. The results of this study indicate that the Virginia Board of Health sanitary code for pool water must be revised immediately and should include all public hydrotherapy and swimming pools. Other states and communities may want to assess their codes for swimming pools and hydrotherapy tubs to avoid deficiencies that could be detrimental to public health.     

In vitro release and tissue levels of ileal serotonin after cisplatin-induced emesis in the cat

We have studied the peripheral mechanisms responsible for the severe vomiting observed in cisplatin treated cats. Release of 5-hydroxytryptamine from isolated portions of the ileum and ileal tissue concentrations of 5-hydroxytryptamine were studiedin vitro with control animals and animals previously treated with cisplatin. In the latter, two groups were observed: animals in which cisplatin (single dose, 10 mg/kg) induced vomiting within 4 h and animals that did not vomit within 4 h. Spectrofluorimetric assessment of 5-hydroxytryptamine in the perfusate and ileal tissue revealed that cisplatin increases both release, and tissue levels, of ileal 5-hydroxytryptamine in animals which vomited, whereas only ileal 5-hydroxytryptamine release was increased in animals which did not vomit. This may have clinical implications as cisplatin induced emesis may be more effectively prevented by drugs preventing ileal 5-hydroxytryptamine formation rather than release.     

Regional blood flow and acid secretion associated with damage and restitution of the gastric surface epithelium in cats

The gastric mucosa of anesthetized cats was exposed to 2 M NaCl for 10 min. After returning to gastric perfusion with 150 mM NaCl and pH 7.40, with and without pentagastrin stimulation, transmucosal potential difference decreased to zero and then gradually increased to approximately half the original value during the following 90 min. H+ secretion decreased and remained close to zero after exposure to 2 M NaCl in nonstimulated cats, whereas pentagastrin-stimulated secretion gradually increased to nearly half the preexposure level. Mucosal blood flow increased, and the vascular resistance decreased in the posterior wall of the stomach corresponding to epithelial damage, as observed by light microscopy after 15 min. Blood flow during pentagastrin stimulation was initially high in fundus and corpus and did not increase further after exposure to 2 M NaCl, but showed similar changes as without pentagastrin in the antrum. Epithelial restitution occurred within 90 min during both nonstimulated conditions and pentagastrin stimulation. In control animals subjected to 150 mM NaCl there were no changes in transmucosal potential difference, H+ secretion, or blood flow throughout the experiment and epithelial damage was not found. In conclusion, damage caused by 2 M NaCl to the gastric surface epithelium was associated with decreased acid secretion and increased mucosal blood flow. These factors may contribute to creating favorable conditions for the epithelial restitution, indicated by restoration of transmucosal potential difference and observed by light microscopy.