Changes in the biliary excretion of organic anions following exhaustive exercise in rats

The effect of exhaustive exercise on the hepatobiliary transport of organic anions was investigated in rats. Animals were run on a rodent treadmill at 24 m/min up a 12% grade (152 +/- 15 min). Exercise resulted in significant hypoglycaemia (-46%) and increased plasma levels of lactate (+12%), together with a marked reduction of glycogen concentration in the liver (-72%). When bromosulphthalein was administered i.v., its maximal biliary excretion (Tm) was significantly reduced (-30%), and plasma and liver concentrations of the dye were increased (+31% and +56%, respectively). The decrease corresponded both to the excretion of the conjugated and unconjugated dye (-30% and -33%, respectively). Cytosolic glutathione S-transferase activity in the liver was not affected by exercise, but there was a significant reduction in the hepatic concentration of glutathione (-50%). The Tm of dibromosulphthalein was also significantly reduced (-36%) and its plasma and liver concentrations increased (+67% and +33%, respectively) in exercised rats. The results suggest that, in addition to the direct effect of liver glutathione depletion, other factors must be involved in the impairment of the biliary excretion of organic anions caused by exercise.     

Die zweizeitige Unterkieferrekonstruktion mit einer 2,7-mm-Überbrückungsplatte

The two-phase reconstruction of the mandible with a 2.7-mm-Martin-reconstruction-plate creates a tumor free period that is followed by bone grafting to the embedded plate. We have treated 61 patients following this pattern from 2000 to 2005, follow-up was done in 56. 14 patients had received radiotherapy of 70?Gy. 43 plates healed in without any complications. Until 2005 bone grafting had been performed in 18 patients, in ten patients the plate had been removed.     

Early reconstruction of the abdominal wall in giant omphalocele.

Omphalocele is the most common congenital defect of the abdominal wall. Mortality rate is between 20 and 70% and early closure of the abdominal wall, within 10 days of life, is vital to the successful outcome of the surgical treatment. The authors describe the use of two bipedicled flaps of abdominal skin to correct the defect of the midline as soon as the reduction of all viscera has been accomplished.     

Intraoral Tumor of Chievitz in a Child

Juxtaoral organs known as organs of Chievitz are intramuscular embryonic structures found close to the angle of the mandible near the insertion of the pterygomandibular raphae. They are considered of neuroepithelial origin with no known function. We describe the first tumor of the organ of Chievitz which presented intraorally in a child. Immunohistochemically, the Chievitz nests showed positive reaction for vimentin, cytokeratins, and epithelial membrane antigen and ultrastructurally demonstrated cytoplasmic processes and intermediate filament bundles. These observations, together with light microscopic features, suggest that the epithelial nests of the organ of Chievitz are meningothelial rather than neuroepithelial. Received December 18, 1996; accepted March 13, 1997.     

On the mechanism of increased potassium conductance by the potassium channel opener BRL 34915 in Isolated ventricular myocytes

The potassium conductance increased by BRL 34915 (BRL, cromakalim) was studied in single guinea pig ventricular myocytes by using a whole cell voltage-clamp technique. In control voltage-clamp recordings, the late current-voltage relation showed a distinct inward rectification. BRL (1–100 μM) shortened the action potential and diminished or abolished inward rectification but had no effect on the slope conductance and currents flowing during hyperpolarizing clamp steps. BRL did not decrease the slow inward current but accelerated the time constant of activation and amplitude of the outward current. Cd markedly decreased (0.2 mM) or abolished (0.4–0.6 mM) the slow inward current and BRL induced a faster outward shift of late current to a greater value. Glybenclamide (10 μM), a blocker of ATP-sensitive K⁺ channels, had little effect of its own on action potential, membrane currents, and I-V relation. However, in the presence of BRL, glybenclamide abolished BRL effects on action potential and currents and restored inward rectification. It is concluded that the mechanism by which BRL shortens the action potential is a faster growth of an outward current due to the reduction or abolition of the inward rectification of an ATP-dependent potassium channel. The reduction in force in non-isolated tissues appears to be an indirect result of the action potential shortening and not of a decreased slow inward current.     

EFFECTS OF STROPHANTHIDIN ON THE SLOW INWARD CURRENT IN GUINEA-PIG ISOLATED VENTRICULAR MYOCYTES

1. The effect of strophanthidin on the slow inward current (Isi) and on contractile force were studied in guinea-pig isolated ventricular myocytes and intact papillary muscles, respectively. In myocytes, both low (10 nmol/L) and high (1-10 mumols/L) concentrations had small or no effects in either direction on Isi whereas norepinephrine (10-100 nmol/L) increased it. To determine whether the same results are obtained after decreasing or increasing intracellular calcium or sodium, the same concentrations of strophanthidin were tested in different procedures that are known to (i) increase [Ca]i and decrease [Na]i (high [Ca]o, 3.6-5.4 mmol/L; low [Na]o, 112 mmol/L; (ii) decrease [Ca]i and increase [Na]i (low [Ca]o, 0.45-1 mmol/L; Sr, 1 mmol/L; (iii) decrease [Ca]i and [Na]i (Cd, 0.1-0.2 mmol/L); and (iv) increase [Ca]i and [Na]i (veratridine, 0.2 mumol/L). High [Ca]o and veratridine increased whereas low [Ca]o and Cd decreased Isi. In contrast, during these various procedures, strophanthidin had small and inconsistent effects at a low or high concentration. In intact papillary muscles, low strophanthidin decreased whereas high strophanthidin increased contractile force. It is concluded that strophanthidin has little direct or indirect effect on Isi and that the decrease in force by low and increase in force by high concentrations in intact muscle are probably related to demonstrated decrease and increase, respectively, in intracellular sodium activity.     

Preliminary experience with new bioactive prosthetic material for repair of hernias in infected fields

Surgisis (Cook Surgical, Bloomington, Ind., USA) is a new four-ply bioactive, prosthetic mesh for hernia repair derived from porcine small-intestinal submucosa. It is a naturally occurring extracellular matrix which is easily absorbed, supports early and abundant new vessel growth, and serves as a template for the constructive remodeling of many tissues. As such, we believe that Surgisis mesh is ideal for use in contaminated or potentially contaminated fields in which ventral, incisional, or inguinal hernia repairs are required. From November 2000 through May 2002, 25 patients (11 male, 14 female) underwent placement of Surgisis mesh for a variety of different hernia repairs. A total of 25 hernia repairs were performed in our patient population. Fourteen procedures (56%) were performed in a potentially contaminated setting (i.e. with incarcerated/strangulated bowel within the hernia or coincident with a laparoscopic cholecystectomy/colectomy). Eleven repairs (44%) were performed in a grossly contaminated field, including one in which an infected polypropylene mesh from a previous inguinal hernia repair was replaced with Surgisis and one in which necrotic bowel was discovered within the hernial sac. Median follow-up was 15 months with a range of 1–20 months. Of the 25 total repairs, there was one wound infection complicated by enterocutaneous fistula in a patient originally operated on for ischemic bowel. The fistula was in a location independent of the Surgisis mesh. There were no mesh-related complications or recurrent hernias in our early postoperative follow-up period. Surgisis mesh appears to be a promising new prosthetic material for hernia repair, especially in contaminated or potentially contaminated fields. Obviously, long-term follow-up is still required. Electronic Publication     

Methamphetamine dependence increases risk of neuropsychological impairment in HIV infected persons.

Both HIV infection and methamphetamine dependence can be associated with brain dysfunction. Little is known, however, about the cognitive effects of concurrent HIV infection and methamphetamine dependence. The present study included 200 participants in 4 groups: HIV infected/methamphetamine dependent (HIV+/METH+), HIV negative/methamphetamine dependent (HIV-/METH+), HIV infected/methamphetamine nondependent (HIV+/METH-), and HIV negative/methamphetamine nondependent (HIV-/METH-). Study groups were comparable for age, education, and ethnicity, although the HIV-/METH- group had significantly more females. A comprehensive, demographically corrected neuropsychological battery was administered yielding a global performance score and scores for seven neurobehavioral domains. Rates of neuropsychological impairment were determined by cutoff scores derived from performances of a separate control group and validated with larger samples of HIV+ and HIV- participants from an independent cohort. Rates of global neuropsychological impairment were higher in the HIV+/METH+ (58%), HIV-/METH+ (40%) and HIV+/METH- (38%) groups compared to the HIV-/METH- (18%) group. Nonparametric analyses revealed a significant monotonic trend for global cognitive status across groups, with least impairment in the control group and highest prevalence of impairment in the group with concurrent HIV infection and methamphetamine dependence. The results indicate that HIV infection and methamphetamine dependence are each associated with neuropsychological deficits, and suggest that these factors in combination are associated with additive deleterious cognitive effects. This additivity may reflect common pathways to neural injury involving both cytotoxic and apoptotic mechanisms.