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.     

Ultrastructure of a two-cell human embryo

Summary A two-cell human embryo recovered from the Fallopian tube 82 h following the LH peak in plasma and 37 h after a single episode of intercourse was examined by transmission electron microscopy. At the time of recovery the embryo was denuded of cumulus cells, and both the zona pellucida and the two adjoining blastomeres were intact. The finding of two polar bodies in the perivitelline space, two nucleated blastomeres and remnants of the fertilizing sperm tail within the cytoplasm of one of them, were considered as evidences that the embryo was normally fertilized. Among the most compicuous features found were the presence of very distinct desmosome-like structure between blastomeres, and the cytoplasmic cell organelles distribution in three areas referred as: a sub-cortical, a middle and a perinuclear bands. An outstanding feature was the extensive blebbing of the nuclear envelope. In general, the features seem to correspond to a normally developing two-cell embryo undergoing cleavage at a normal rate.     

Comparatice effects of loratadine and selected antihistamines on sleep-waking patterns in the cat

The central effects of the new antihistamine loratadine and three reference antihistamine agents were studied in the cat. As a sensitive measure of drug action on the central nervous system (CNS) we evaluated changes in sleep-waking patterns. For comparison, diphenhydramine was studied as an example of an antihistamine having potent central effects; astemizole and terfennadine were used as examples of new agents claimed to be free of CNS effects. Diphenhydramine, given at 3 mg/kg p.o., increased spindle sleep, i.e., the electrophysiological correlate of drowsiness, and suppressed rapid eye movement (REM) sleep. In addition, cats displayed unusual sleep postures during the various sleep stages. Loratadine had little or no effect on the various features of sleep-waking patterns over a broad dose range (3 and 30 mg/kg p.o.). Astemizole, at 30 mg/kg p.p., significantly increased wakefulness and reduced both slow-wave sleep and REM. No significant changes of the sleep patterns occurred after the low dose of 3 mg/kg. Terfenadine reduced REM duration at 30 mg/kg p.o. but had no effects on sleep patterns at 3 mg/kg. The cat appeared to be a sensitive animal model to the central action of antihistamines since the reference drug diphenhydramine affected sleep-waking patterns at a dose that closely approximates the dose requirements for adverse CNS effects in man. Under the same conditions, loratadine was free of central actions at a dose range far above that effective either therapeutically or in standard tests in other animal species. Astemizole and terfenadine seemed to be devoid of CNS effects at doses similar to those effective as antihistamines in man, but they produced some central actions at higher doses. Comparing the clinically effective doses of the antihistamines examined, loratadine appears to be the least liable to produce adverse effects on the CNS function.