Pathophysiological advantages of rinsing-suction-reaming (RSR) in a pig model for intramedullary nailing.

Although reamed intramedullary nailing has been one of the greatest advances in modern fracture care, the concomitant increase in medullary cavity pressure leads to intravasation of bone marrow content into the blood stream, an effect that can evoke serious systemic reactions. A newly developed rinsing-suction-reamer (RSR) was able to substantially reduce the pressure and bone marrow intravasation content during experimental femoral nailing. We investigated the pathophysiological effects using the RSR, testing the hypothesis that by reducing marrow fat embolization, RSR would also reduce the activation of coagulation compared with the universal AO-Reamer (AOR) and comparable to external fixation. Twenty-two pigs were treated with either simulated external fixation or reamed femoral nailing using AOR or RSR. During surgery, the intramedullary pressure was measured and intravasation of medullary material was quantified. After surgery, the pigs were kept anaesthetised and monitored for 6 h. At defined intervals, serological, hematological, and hemodynamic parameters were evaluated. The RSR was significantly superior when compared to AOR with regard to the generation of intramedullary pressure and fat embolization; however, with external fixation the values were even lower. The evaluation of other parameters revealed no clear differences between the two reamers and the external fixator. The pig model showed that RSR led to a significant reduction of the intramedullary increase in pressure and fat intravasation compared to AOR. Although the reduction of fat embolism by RSR is not associated with pathophysiological changes, RSR can have advantages for the treatment of femoral fractures.     

Association of cortical disinhibition with tic, ADHD, and OCD severity in Tourette syndrome.

Hyperkinetic disorders may involve excess excitatory output from thalamus to cerebral cortex. Case-control, neurophysiological studies in persons with Tourette Syndrome (TS), Attention Deficit Hyperactivity Disorder (ADHD), and Obsessive-Compulsive Disorder (OCD) support this model. To compare the strength of association between motor cortex inhibition and tic, ADHD, and OCD severity in TS, we used transcranial magnetic stimulation to measure motor cortex inhibition in 36 children and adults with TS. Current symptom severity was assessed with standard clinical rating scales and compared with neurophysiological measures using correlational and multivariate regression analyses. Severity of ADHD symptoms and motor tics were associated significantly and independently with short interval intracortical inhibition (SICI) (r(2) = 0.50; F[2,27] = 13.7; P < 0.001), particularly in subjects not taking neuroleptics (r(2) = 0.68; F[2,17] = 17.8; P < 0.0001). The correlation of cortical disinhibition was greater with ADHD symptoms severity (r = 0.53; P = 0.003) than with tic severity (r = 0.42; P = 0.02), suggesting that in TS, the association between SICI and ADHD symptoms may be more consistent or direct than the association between SICI and tics.     

Nitrogen mustard-mediated mutagenesis in human T-lymphocytes in vitro

The cytotoxic and mutagenic effect of the bifunctional alkylating agent nitrogen mustard (HN₂) was examined. Primary human lymphocytes were exposed to graded doses of HN₂ in vitro and relative survival was determined. Mutation induction at the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus was measured by cloning the exposed T-cells in microtitre plates in the presence and absence of 6-thioguanine (TG). The IC₅₀-value determined for 30 min exposure to HN₂ was 1.34 μM. The mutant frequencies (MF) in exposed T-cell cultures were 10-fold (2 μM HN₂) to 32-fold (4 μM HN₂) higher than those of unexposed cultures (median values). Nitrogen mustard-mediated mutagenesis is discussed in terms of the current ideas about DNA damage and repair. Received: 14 May 1996 / Accepted: 28 August 1996     

Blood flow redistribution by dopamine in the feline gastrointestinal tract

Summary The effect of intravenous infusion of dopamine (10 and 25 g·kg^–1·min^–1 consecutively) on visceral blood flow distribution was examined in anesthetized cats using the microsphere technique and electromagnetic flowmetry. Arterial blood pressure did not change in response to dopamine infusion, but blood flow through the superior mesenteric artery, and blood flow in the mucosa-submucosa of the gastric antrum and various gut segments increased significantly. During infusion of the high dose the increase was most marked in the mucosa-submucosa of the antrum (+355%) and distal colon (+371%). By contrast, blood flow decreased in the muscularis-serosa of the gut segments investigated, in the spleen, pancreas, and the hepatic arterial bed. The increase in blood flow through the superior mesenteric artery was blocked by the dopamine antagonist bulbocapnine (10 mg/kg i.v.). The results suggest that the receptors mediating the dopamine-induced vasodilation in the gastrointestinal tract are located in the resistance vessels of the mucosa-submucosa.     

Ueber die Gewinnung der Diphtherie-Antitoxine aus Blutserum und Milch immunisirter Thiere

Ohne Zusammenfassung     

Über die Verwendung von frischem,unabgebautem Toxin zur Herstellung und Prüfung von Diphtherieantitoxin

Ohne Zusammenfassung     

Ueber die persönliche Disposition und die Prophylaxe gegenüber Diphtherie

Ohne Zusammenfassung