Beanspruchung und Umbau bei der Alloarthroplastik des coxalen Femurendes des Hundes mit einer selbsthaftenden Tragrippenprothese

Zusammenfassung Um die zusätzliche Verwendung von Kunstharzen zur Verankerung der Totalprothese der Hüfte zu umgehen, hat Mittelmeier eine selbsthaftende Tragrippenprothese mit besonders gestalteter Oberfläche des Prothesenstieles angegeben. Nach einjähriger Implantationsdauer im Tierexperiment (Hund) wird der endoprothetisch versorgte und der kontralaterale normale Femur des Hundes funktionell und morphologisch untersucht. Unter statischer Belastung werden mit Dehnungsmeßstreifen die Beanspruchung und in photographischen und Röntgenaufnahmen der Umbau des Knochens nach Prothetik untersucht. Im Bereich des Prothesenstieles ergeben sich Umbauvorgänge, welche mit den geänderten Beanspruchungen übereinstimmen. Der Knochen gleicht sich an eine in Richtung und Höhe gänzlich geänderte Beanspruchung durch eine Spongiosierung des oberen Teils der Femurdiaphyse zweckmäßig an. Dieser Vorgang wird als kompensatorische Metaphysierung des Schaftes bezeichnet (Diehl).

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Stresses and functional adaptation of alloarthroplasty of the proximal femur in dogs using a selfcuring rippled prosthesisA comparative biomechanical and morphological study

Summary A self-adhesive prosthesis for youth patients is developed by Mittelmeier that is implanted without bone cement. After an implantation term of 1 year in animal experiment (dog), an adapted femur is compared with the contra-lateral normal femur. Strain gauges are used to determine bone strain under load. Further is determined external and internal construction change after endoprosthesis. The construction changes found are in connection with the changed bone strength. A cancellous change of bone at entire area of stem of prosthesis is called a ;metaphysation; of bone shaft.

     

Biliary atresia: which factors predict the success of a Kasai operation? An analysis of 36 patients

Biliary atresia (BA) is one of the most frequent causes of neonatal cholestasis. Portoenterostomy is one therapeutic option in these patients with a success rate of 30-40%. To answer the question of therapy liver transplantation or Kasai operation - we analyzed 36 consecutive patients being followed in our center during the past 7 years. Two groups were formed: group I : patients developing cirrhosis within the first 2 years of life with the need for liver transplantation (n = 21). Group II: patients without need for transplantation within the first 2 years of life (n = 15). The two groups were compared regarding birth weight, age at diagnosis, age at Kasai-procedure, liver histology. The following biochemical parameters were analyzed at the time of diagnosis, 1 week and 5 weeks after Kasai: AST, ALT, gammaGT, and bilirubin. - Results: Clinical characteristics were similar in both groups. However BA was diagnosed in group I 8.2 weeks after birth compared to 5.6 wk in group II. gammaGT, ALT, AST, and bilirubin were similar in both groups at the time of diagnosis and 1 wk after Kasai. However 5 wk after Kasai gammaGT was 276 U/l in group I compared to 72 U/l in group II (p <0.001), bilirubin was 6.3mg/dl in group I compared to 2. 3mg/dl in group II (p <0.001). - Conclusion: Kasai operation before the 7th wk of life increases the success rate of this technique significantly. Children with cirrhosis at the time of diagnosis should be evaluated for primary liver transplantation. gammaGT and bilirubin 5 weeks after Kasai operation may be useful markers for the success of this procedure. Patients with a gammaGT > 100 U/l and a bilirubin level >5mg/dl should be followed closely and should be evaluated for liver transplantation early.     

Mukormykose als Ursache einer nekrotisierenden Enterokolitis

Zusammenfassung Die gastrointestinale Mukormykose ist ein seltenes Krankheitsbild. Betroffene Frühgeborene fallen durch eine Perforation im Magen-Darm-Trakt oder eine nekrotisierende Enterokolitis auf. Wir stellen ein Frühgeborenes der 24. SSW mit einer Darmperforation vor, bei dem eine Mukormykose des Darms sowohl durch die Kultur als auch im histologischen Pr?parat nachgewiesen wurde. Im Gegensatz zur „klassischen” nekrotisierenden Enterokolitis lag keine Pneumatosis intestinalis vor, es kam sehr früh zu einer Darmperforation, und der Dünndarm zeigte eine ausgepr?gte Minderperfusion. Diese Punkte k?nnten die Differenzierung zwischen gastrointestinaler Mukormykose und typischer nekrotisierender Enterokolitis erleichtern, was von Bedeutung ist, da nur die frühzeitige Diagnosestellung einen raschen Therapiebeginn (chirurgische Sanierung, Amphotericin B) und damit eine Verbesserung der schlechten Prognose erm?glicht.      

A prospective study of methylenetetrahydrofolate reductase and methionine synthase gene polymorphisms, and risk of colorectal adenoma

We examined the relationship between a functional polymorphism (667C-- >T, ala-->val) of the methylenetetrahydrofolate reductase gene (MTHFR) and the risk of colorectal adenomas in the prospective Nurses' Health Study. Among 257 incident polyp cases and 713 controls, the MTHFR val/val polymorphism [relative risk (RR) = 1.35, 95% confidence interval (CI) 0.84-2.17] was not significantly associated with risk of adenomas. This lack of association was observed for both small (RR = 1.36, 95% CI 0.76-2.45) and large (RR = 1.32, 95% CI 0.66-2.66) adenomas. Furthermore, there was no significant interaction between this polymorphism and consumption of either folate, methionine or alcohol. We also examined the relationship of a newly identified polymorphism (asp919gly) of the methionine synthase gene (MS) with the risk of colorectal adenomas in the same population. The MS gly/gly polymorphism was also not significantly associated with risk of colorectal adenomas (RR = 0.66, 95% CI 0.26-1.70). These results, which need to be confirmed in other studies, suggest that the MTHFR val/val polymorphism, which has been previously inversely associated with risk of colorectal cancer, plays a role only in a late stage (adenoma-- >carcinoma) of colorectal tumorigenesis, and/or may protect against malignant transformation in the subset of benign adenomas, which may progress to malignancy.      

Hyperbaric oxygenation induced tolerance against focal cerebral ischemia in mice is strain dependent

SV129 or C57BL/6 mice were exposed to hyperbaric oxygenation (HBO, 5 days, 1 h every day, 100% O(2) at 3 atm absolute). One day after the 5th HBO session focal cerebral ischemia was induced. In SV129 mice, HBO induced tolerance against permanent focal cerebral ischemia (n=42, mean infarct volume reduction 27%, P=0.001), but not against transient (30 or 60 min) focal cerebral ischemia. In the C57BL/6 strain of mice, HBO did not induce tolerance against focal cerebral ischemia, even when the duration of ischemia or the HBO protocol were modified. For the first time we demonstrate that HBO can induce tolerance to focal cerebral ischemia, but this effect is strain dependent.     

Efficacy and safety of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. Multicenter phase III clinical trials. Efficacy of early imaging

The efficacy of contrast-enhanced magnetic resonance imaging (MRI) for detecting and characterizing, or excluding, hepatic masses was assessed in 404 patients, following the intravenous administration of mangafodipir trisodium (MnDPDP) injection, a hepatic MRI contrast agent. An initial contrast-enhanced computed tomography (CT) examination was followed by unenhanced MRI, injection of MnDPDP (5 micromol/kg IV), and enhanced MRI at 15 minutes post injection. Agreement of the radiologic diagnoses with the patients' final diagnoses was higher for enhanced MRI and for the combined unenhanced and enhanced MRI evaluations than for unenhanced MRI alone or enhanced CT using the clinical diagnosis as the gold standard. Mangafodipir-enhanced MRI uniquely provided additional diagnostic information in 48% of the patients, and patient management was consequently altered in 6% of the patients. MnDPDP-enhanced MRI was comparable or superior to unenhanced MRI and enhanced CT for the detection, classification, and diagnosis of focal liver lesions in patients with known or suspected focal liver disease.     

Safety and efficacy of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. multicenter phase III clinical trials (safety)

The short-term safety of mangafodipir trisodium (MnDPDP) injection was studied in 546 adults with known or suspected focal liver lesions. An initial contrast-enhanced computed tomography examination was followed by unenhanced magnetic resonance imaging (MRI), injection of MnDPDP (5 micromol/kg), and enhanced MRI. Adverse events were reported for 23% of the patients; most were mild to moderate in intensity, did not require treatment, and were not drug related. The most commonly reported adverse events were nausea (7%) and headache (4%). The incidence of serious adverse events was low (nine events in six patients) and not drug related. Injection-associated discomfort was reported for 69% of the patients, and the most commonly reported discomforts included heat (49%) and flushing (33%). Changes in laboratory values and vital signs were generally transient, were not clinically significant, and did not require treatment. There were no clinically significant short-term risks from exposure to MnDPDP.     

Acute treatment of hypertension increases infarct sizes in spontaneously hypertensive rats

We studied the effect of dihydralazine treatment of hypertension in spontaneously hypertensive stroke-prone rats in a model of permanent focal cerebral ischemia (stroke). After occlusion of the middle cerebral artery systemic arterial pressure (SAP) was lowered with a computer controlled infusion device from 163 to 135 or 117 mm Hg for 24h. In the control group SAP was not manipulated. Reduction of SAP to normotension (117 mm Hg) significantly worsened outcome and increased infarct volume measured 7 days after induction of ischemia, whereas a mild reduction of SAP (to 137 mm Hg) had no statistically significant effect on outcome or infarct volume. We conclude that pharmacological treatment of hypertension may negatively affect neurological outcome and infarct volume in a rat stroke model.