Influence of microbial activity on polar xenobiotic degradation in activated sludge systems.

The influence of activated sludge quality on the co-metabolic biodegradation of three aminocarboxylic [corrected] acids was investigated for a variety of Luxembourg sewage treatment plants. A combination of biodegradation experiments and respirometric techniques are presented as a reliable approach for the estimation of biokinetics and biological xenobiotic degradation rates that allow for identification of governing parameters such as microbial activity and active biomass. Results showed that biokinetics and degradation rates vary greatly between different plants. The fraction of active biomass on the total suspended solids ranged between 16.9 and 53.7%. Xenobiotic biodegradation rates correlated with microbial activity suggesting a relationship with WWTP performance for carbon and nutrient removal. The biokinetic information can be used to increase the prediction accuracy of xenobiotics removal by individual WWTPs.

[What influence doe the implant have on the perioperative morbidity following internal fixation of proximal femur fracture? Analysis of dynamic hip screw and proximal femoral nailing]. / Welchen Einfluss hat das Implantat auf die perioperative Morbidität bei osteosynthetischer Versorgung pertrochantärer Femurfrakturen? Analyse von dynamischer Hüftschraube und proximalem Femurnagel.

RATIONALE: Proximal femur fracture is a frequent finding in elderly patients. Both the dynamic hip screw (DHS) and the proximal femur nail (PFN) are established implants. The aim of our study was to assess the perioperative morbidity in a sample of 112 patients with proximal femur fracture, operated on with either DHS or PFN. MATERIAL AND METHODS: Data of 112 consecutive patients (59 DHS, 53 PFN), which consisted of 20 variables, were obtained. Nine variables were selected, which were considered to possess a potential impact on the complication rate. These variables were type of implant, sex, age, period between trauma and surgery, ASA classification, fracture classification of the ASIF, duration of surgery, blood loss, and antibiotics. They were transformed into dichotomous data to enable univariate statistical analysis and logistic regression. RESULTS: The ASA classification only was evaluated to have a predictive value as shown by the odds ratio of 2.23 (90 % confidence interval: 1.09 - 4.56). ASA 3 or 4 patients had an expected frequency, which was 2.2-fold increased as compared to patients classified as ASA 1 or 2, to suffer from perioperative complications. Using logistic regression, again the ASA classification only was shown to have a significant impact (p = 0.066, level of significance: p < 0.1) on the perioperative morbidity. CONCLUSION: As suggested by our results, neither the type of implant nor the other variables mentioned above had a significant impact on the resulting complication rate in our study sample. The ASA classification only was found to significantly increase the probability of an adverse event. This finding should be taken into account prior to initiating therapy.

[Macro- and microreplantations of the lower leg and foot]. / Makro- und Mikroreplantationen an Unterschenkel und Fuss.

Amputations suitable for replantation in the distal lower leg and foot are seldom. There is no indication if shortening will exceed 5 cm or loss of sensitivity is to be expected. Forefood and toe replantations are to be seen predominantly under aesthetic points of view. Satisfactory results in 10 own cases could be achieved if indications for lower leg replantations were limited to guillotine-type amputations, children and some bilateral lesions. Polytrauma as a rule is not a good indication.

[Growth behavior of microvein and artery grafts]. / Wachstumsverhalten von Mikrovenen- und -arterieninterponaten.

In an experimental study with young rats the authors were able to prove that arterial and venous grafts show almost normal growth. With respect to patency rate, growth and integrity of the vessel wall the results with arterial grafts were more satisfactory than those with venous grafts. Examination of thirty-four patients who had undergone replantation or transplantation in infancy or childhood, showed that after digital replantation the extremities grew almost normally and that there was no indication of lag in vessel growth. Three times a slight change in growth after major limb replantations was found, in one case there was a slight increase in growth and in another case the growth was considerably diminished. In the latter there had been total destruction of the epiphyseal line. One large replantation was examined by angiography and normal development of the venous grafts was found.

[Reconstruction of combined soft tissue and bone defects of the lower leg]. / Wiederherstellung bei kombinierten Weichteil- und Knochendefekten des Unterschenkels.

In 7 patients with traumatic defects of the soft parts and bone of the lower leg the authors transplanted a free latissimus dorsi flap with microvascular connection. The surgical technique and approach are described. Secondary autologous spongioplasty. The results are stated. The method is a safe one.

[Microsurgical aspects of wound healing in the extremities (author's transl)]. / Mikrochirurgische Aspekte der Wundheilung an den Extremitäten.

Microsurgical operative technique made it possible to restore the arterial and venous blood flow or to improve it, even for a relatively small tissue area, and to re-innervate these fabrics. Reconstruction of lymphatic drainage is technically possible, but quite a number of problems remain to be solved before further clinical application is possible. Grafting of a microvascularly pedunculated bone chip is superior to the bone chip without primary vascularisation, but will offer advantages over grafting of spongiosa in very rare cases only. At the present moment it is not yet possible to safely assess the influence exercised by re-innervation on wound healing.

[Microsurgical plastic reconstruction of the explosion-damaged hand]. / Mikrochirurgisch-plastische Versorgung der explosionsverletzten Hand.

During the last two years, 16 severe explosion injuries of the hand have been treated with plastic microsurgery in our hospital. The injury had arisen in seven cases from the mixture sugar + sodium chlorate (C12H22O11 + NaClO3). This substance mixture may already be caused to explode by slight vibrations and the warmth of the hands. In explosion injuries, there is mechanical, chemical and thermal tissue damage. The postoperative course is therefore complicated in almost all cases. However, by meticulous removal of the disseminated foreign particles, excision of necrotic tissue and extensive reconstruction of the interrupted vascular and nerve supply, it is possible in a few cases to preserve functionally important parts of the hand. Later plastic procedures are made more difficult by tissue fibrosis and foreign body granulomas.