Dependency of the metabolic effect of sc-injected human regular insulin on intra-abdominal fat in patients with type 2 diabetes

Ten patients with type 2 diabetes were enrolled in an isoglycemic glucose clamp study to determine the impact of intra-abdominal fat, subcutaneous abdominal fat and total abdominal fat on the metabolic effect of a single bolus (0.2 IU/kg) of sc-injected human regular insulin. The maximum metabolic effect associated highly and negatively with intra-abdominal fat (r = - 0.72, p < 0.02) and with the homeostasis model assessment insulin resistance score (HOMA, r = - 0.71, p < 0.03). Likewise, the total metabolic effect of sc-injected insulin correlated strongly and negatively with intra-abdominal fat (r = - 0.77, p < 0.01), HOMA (r = - 0.74, p < 0.02) and HbA (1c) (r = - 0.70, p < 0.03). Stepwise multiple regression analyses showed that the highest metabolic effect was only significantly predicted by intra-abdominal fat, indicating a high negative correlation with the maximum effect (beta = - 0.72) whereas time to maximum metabolic effect showed a strong (beta = 0.72) and positive correlation with HOMA. In combination with the HOMA, it is intra-abdominal fat, and not subcutaneous abdominal fat, which explains 50 - 75 % of the variability of the effect of sc human regular insulin in patients with type 2 diabetes.

Olanzapine Plasma Concentration, Average Daily Dose, and Interaction with Co-Medication in Schizophrenic Patients

BACKGROUND

Olanzapine, a thienobenzodiazepine, is one of the relatively new atypical antipsychotic drugs. The lowest threshold of effective olanzapine plasma levels in inpatient treatment is assumed to be 9 ng/ml. Very little is known about the plasma concentration in patients at various oral doses of olanzapine or about the clinically relevant interactions with co-medications.

METHODS

In 71 schizophrenic patients (age 32.6 +/- 12.1, range 18-63 years; 31 women, 40 men), plasma olanzapine levels were assessed in 377 tests by high-performance liquid chromatography (HPLC) with electrochemical detection. Fifty-six of these plasma levels were assessed while patients were receiving olanzapine as monotherapy; otherwise, the plasma levels were assessed with the patients receiving various co-medications.

RESULTS

The mean daily oral dose of olanzapine was 17.5 mg (SD = 7.0, range 5-40 mg), and the mean olanzapine plasma concentration was 54.2 ng/ml (SD 37.8 ng/ml, range 1.2-208 ng/ml). The plasma concentration of olanzapine increased linearly with the daily oral dose (r = 0.64, p < 0.001). A multiple variance analysis considering age and sex as covariables showed a significant difference in the dose-corrected plasma levels of olanzapine among 40 smokers and 31 non-smokers; age and sex did not affect the dose-corrected plasma levels. However, women received a significantly lower daily dose of olanzapine under routine clinical study conditions. No differences could be detected among the dose-corrected plasma concentration of those patients who were taken off olanzapine because they did not respond (n = 14) or because of side effects (n = 5) and those who were discharged while still on olanzapine. Under the co-medication with fluvoxamine, significantly higher dose-corrected olanzapine plasma concentrations were found than with olanzapine monotherapy, whereas significantly lower dose-corrected olanzapine plasma concentrations were detected under lithium and trimipramine co-medication. Under co-medication with amitriptyline, benperidol, carbamazepine, flupentixol, and lorazepam, the dose-corrected olanzapine plasma concentrations were no different than the plasma levels under olanzapine monotherapy.

CONCLUSIONS

The relevance of therapeutic drug monitoring is emphasized with respect to the data presented and to the literature. Future studies should examine, in particular, the effects of a wider range of co-medications in a larger patient sample.

[The microsurgical lymph vessel transplantation]

Using advanced microsurgical techniques, single lymph vessels can be safely anastomosed and segments of lymphatics can bridge localized lymphatic blockades which are mostly due to lymphadenectomies. Lymphatic grafts are harvested from the patient's thigh with a length up to about 30 cm. In the case of an axillary blockade they are anastomosed with ascending lymph vessels at the upper arm and lymph vessels at the supraclavicular region. Unilateral oedemas of lower extremities are treated by transferring the grafts via the symphysis and anastomosing them with ascending lymphatics at the affected side. Lymphoedemas of the penis and the scrotum as well as lymphoedemas due to a localized peripheral lymphatic blockade can be treated by lymphatic grafts. In 127 arm oedemas the original difference in volume between the affected and the healthy arm was reduced at two third from 3368 cm (3) to 2567 cm(3) (p < 0.001). After a follow-up period of 2.6 years the volume was reduced to 2625 cm(3) (p < 0.001). The group of patients with a follow-up of at least ten years showed a volume of 2273 cm(3) (p < 0.001). The volume of unilateral lower extremity-lymphoedemas was reduced from 13 098 cm(3) to 10 578 cm(3) (p < 0.001) and showed a volume of 11 074 cm(3) after 1.7 years (p < 0.001) and 10 692 cm(3) after four years (p < 0.001). The original mean volume of the healthy contralateral leg was 9371 cm(3). Bridging localized gaps in the lymphatic system by autologous lymphatic grafts showed long lasting stable results. Starting the treatment of lymphoedemas by conservative procedures, one should not wait too long to ascertain the possibility of a microsurgical reconstruction in order to avoid increasing secondary tissue changes.

Omeprazole reduces clozapine plasma concentrations. A case report

A number of interactions of the atypical antipsychotic clozapine with other drugs are well known, some of which can be attributed in part to the pharmacokinetic interactions associated with cytochrome P450 enzymes during drug metabolism. Clozapine is mainly metabolized by the cytochrome P450 isoenzyme 1A2. The proton pump inhibitor omeprazole can induce CYP1A2. We report on two patients with schizoaffective disorder who received omeprazole in addition to clozapine because of gastrointestinal complaints. Before the co-medication with omeprazole was started, the patients had been receiving clozapine for 78 and 41 days and for 40 and 8 days at a stable daily dose of 325 mg (patients 1 and 2, respectively). The co-medication with omeprazole was associated with a reduction in the plasma levels of clozapine of 41.9 % and 44.7 %, respectively, in these patients. The decrease in the plasma concentrations of clozapine in the presence of omeprazole might be due to the induction of the cytochrome P450 isoenzyme CYP1A2. If patients are receiving omeprazole as co-medication, close monitoring of plasma clozapine levels is recommended. If clozapine levels drop, the drug should be adjusted accordingly. If necessary, an alternative to omeprazole should be chosen.

Endoscopic-assisted microsurgery: microsurgery in the new millennium? A comparative experimental study

Endoscopes are already present in almost all plastic surgery departments. The operating microscope is currently an essential piece of equipment for performing microsurgical anastomoses; however, microsurgery could be conducted using other equipment, including the endoscope. By performing 60 vessel and nerve repairs in rats under the operating microscope and the same number using the endoscope as a visual aid, we investigated the technical and clinical differences between the two instruments. We recorded significantly shorter operative, vascular preparation and anastomotic times in the endoscopically assisted group. Based on the data collected during this study, we conclude that microsurgery is possible with the aid of an endoscope. Using the endoscope may make prolonged microvascular procedures shorter and less physically demanding and may increase the comfort level of both the surgeon and the assistant.

[Vascularisation of a free jejunal graft at the neck in an insufficient vascular situation]

Free jejunal grafts are the method of choice for one-stage reconstruction of the hypopharynx and the upper esophagus. Prerequisites for a successful free transplantation are a sufficient arterial vascularisation and a corresponding venous drainage. In a 59-year old patient, an esophagectomy was performed because of a proximal esophageal cancer. The passage was primarily reconstructed by a pedicled colon interposition. Necrosis of the cranial graft occurred. After resection of the necrotic bowel, a free jejunal graft was introduced thoraco-cervically. The nutrient vessels of the graft were anastomosed to the upper thyroid artery and the vena thyroid ima. In an operative revision one day postoperatively due to lacking re-capillarisation, the arterial inflow stopped. The superior thyroid artery was cut at its cranial origin at the external carotid artery and microsurgically implanted into the common carotid artery. Hereafter, a venous outflow was re-established. But the critical time of ischaemia was exceeded. In another operative revision, the cephalic vein was exposed at the cranial upper arm, distally cut and anastomosed to the re-implanted superior thyroid artery. After the harvest of a second autogenous jejunal graft, the arterio-venous shunt was cut and the segments were anastomosed to the mesenterial artery and vein. Transpositions of arteries and veins with temporary formation of an arterio-venous shunt may be prerequisites for a sufficient vascularisation and can enable a successful free microsurgical transplantation even in critical vascular situations.

Microembolic signal counts increase during hyperbaric exposure in patients with prosthetic heart valves

BACKGROUND

Patients with prosthetic heart valves have an increased risk of thromboembolic events, and transcranial Doppler sonography reveals microembolic signals. Whereas microembolic signals were initially assumed to be of particulate matter, recent studies suggest that they are partially gaseous in origin. If this is true, alteration of environmental pressure should change microembolic signal counts. We undertook this study to evaluate the influence of hyperbaric exposure on microembolic signal counts in persons with prosthetic heart valves.

METHODS AND RESULTS

Microembolic signal counts were monitored by transcranial Doppler sonography of both middle cerebral arteries under normobaria (normobaria 1), 2 subsequent periods of hyperbaria (2.5 and 1.75 bar), and a second period of normobaria (normobaria 2) in 15 patients with prosthetic heart valves. Each monitoring period lasted 30 minutes. Compression and decompression rates were 0.1 bar/min. Microembolic signal counts increased from 20 (12-78) at normobaria 1 to 79 (30-165) at 2.5 bar (P <.01 vs normobaria 1 and 2), decreased to 44 (18-128) at 1.75 bar (P <.01 vs normobaria 1 and 2.5 bar; P <.001 vs normobaria 2), and returned to 20 (8-96) at normobaria 2 (values are medians and 95% confidence intervals).

CONCLUSIONS

Our results strongly suggest that gaseous bubbles are underlying material for part of the microembolic signals detected in patients with prosthetic heart valves.

Glutamate receptors form hot spots on apical dendrites of neocortical pyramidal neurons

Apical dendrites of layer V cortical pyramidal neurons are a major target for glutamatergic synaptic inputs from cortical and subcortical brain regions. Because innervation from these regions is somewhat laminar along the dendrites, knowing the distribution of glutamate receptors on the apical dendrites is of prime importance for understanding the function of neural circuits in the neocortex. To examine this issue, we used infrared-guided laser stimulation combined with whole cell recordings to quantify the spatial distribution of glutamate receptors along the apical dendrites of layer V pyramidal neurons. Focally applied (<10 microm) flash photolysis of caged glutamate on the soma and along the apical dendrite revealed a highly nonuniform distribution of glutamate responsivity. Up to four membrane areas (extent 22 microm) of enhanced glutamate responsivity (hot spots) were detected on the dendrites with the amplitude and integral of glutamate-evoked responses at hot spots being three times larger than responses evoked at neighboring sites. We found no association of these physiological hot spots with dendritic branch points. It appeared that the larger responses evoked at hot spots resulted from an increase in activation of both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors and not a recruitment of voltage-activated sodium or calcium conductances. Stimulation of hot spots did, however, facilitate the triggering of both Na+ spikes and Ca(2+) spikes, suggesting that hot spots may serve as dendritic initiation zones for regenerative spikes.

[Possible variations of free autogenous jejunum transplantation for differential reconstruction of the oropharynx]

INTRODUCTION

Resections of extensive tumours, recurrences and radiodermatitides at the neck cause complex defects. Free bowel transplantation enables one-stage reconstruction.

PATIENTS AND METHODS

In 35 out of 57 interdisciplinarily treated patients, small-bowel transplantation was performed for reconstruction. Thirty patients received cylinder grafts, five jejunal patch plastics. In four patients neoglottis formations according to Ehrenberger were performed. To cover soft tissue defects, two patients received scapular free flaps, eight patients a jejunal segment, incised at the anti-mesenteric side, the mucosa stripped and covered by a split skin graft.

RESULTS AND CONCLUSIONS

Thirty-four grafts were viable. One patient received a successful re-transplantation. One postoperative fistula at the hypo-pharyngojejunostomy was closed by a separated jejunal segment which was primarily used as monitor, two others by pectoral flaps. Separation of a jejunal graft into two or three segments enables restoration of swallowing, voice and covering soft tissue in a one-stage procedure. The whole reconstruction necessitates only one arterial and one venous microanastomosis at the neck.

Effects of lamotrigine on field potentials and long-term potentiation in guinea pig hippocampal slices

PURPOSE

To investigate the effects of lamotrigine (LTG), a new anticonvulsant, on neuronal excitability, synaptic transmission, and long-term potentiation (LTP) in guinea pig hippocampal slices.

METHODS

Electrically evoked field excitatory postsynaptic potentials (fEPSPs) and population spikes (PSs) were investigated in the CA1 region of the hippocampus.

RESULTS

The concentration-response curves showed different actions of LTG in concentrations near therapeutic plasma levels (10 microM) on fEPSPs and PSs. The initial slopes of fEPSPs were not affected, whereas the amplitudes of PSs were significantly decreased. Higher concentrations of LTG decreased both fEPSP slopes and PS amplitudes; however, the effects on PSs were much stronger. Also, there were no differences in fEPSP slopes or PS amplitudes compared with controls when LTP was induced in the presence of LTG (10 microM).

CONCLUSIONS

Our data are in contrast to previous findings that suggest LTG acts primarily on presynaptic sites by blocking the release of excitatory amino acids. Further, LTP was not affected by LTG.

Precisely localized LTD in the neocortex revealed by infrared-guided laser stimulation

In a direct approach to elucidate the origin of long-term depression (LTD), glutamate was applied onto dendrites of neurons in rat neocortical slices. An infrared-guided laser stimulation was used to release glutamate from caged glutamate in the focal spot of an ultraviolet laser. A burst of light flashes caused an LTD-like depression of glutamate receptor responses, which was highly confined to the region of "tetanic" stimulation (<10 micrometers). A similar depression of glutamate receptor responses was observed during LTD of synaptic transmission. A spatially highly specific postsynaptic mechanism can account for the LTD induced by glutamate release.

Secondary ischaemia in experimental free flaps--treatment by long acting prostacyclin analogues

Secondary postoperative ischaemia due to venous occlusion is the most detrimental insult to free microvascular flaps. In an experimental rat free flap model the efficacy of long acting prostacyclin analogues iloprost (Ilomedin) and cicaprost in venous occlusion induced postoperative ischaemia was studied. Free, microvascular groin flaps were transplanted to the neck and the draining veins were temporarily occluded on the first postoperative day for a total of 20 min. In the untreated control group, haemorrhagic flap necrosis occurred. Intravital microscopy after secondary ischaemia revealed flap areas without reperfusion. The functional vessel density was significantly reduced. Reperfused capillaries were tortuous and significantly dilated. After reperfusion the interstitial leakage of macromolecular dextran increased, indicating loss of microvascular endothelial integrity. Intraarterial and intravenous applications of iloprost were able to diminish the ischaemic effects, giving a flap survival rate of 83%. Similar results were obtained by intravenous and enteral administration of cicaprost. Transcutaneous oxygen partial pressure measurements confirmed the viability of the surviving flaps. We conclude that both iloprost and cicaprost are effective in preventing venous occlusion induced failure of free microvascular groin flaps.

Liposuction technique and lymphatic lesions in lower legs: anatomic study to reduce risks

Liposuction is a standard procedure in plastic surgery. Especially, lipectomy with suction of the lower extremities has been of greater interest in recent years. Until now, however, there was no definite information about the integrity of epifascial lymph collectors during this procedure. To study the effect of liposuction devices on lymph vessel injury, postmortem lymphatic preparations were done in five human cadavers (10 lower extremities). Conventional liposuction with a blunt 4-mm cannula and a dry technique was used. Adiposuction was performed either in parallel to the extremity axis and, therefore, in parallel to the superfascial lymph vessels or transversally in an 80- to 90-degree angle to the extremity. Careful surgical preparation of the regions followed. A specific macroscopic lymph vessel injury score was applied to differentiate 3 degrees of lymph vessel lesions according to the extravasation of patent blue. In all lower extremities, postmortem lymph flow occurred as indicated by patent blue staining of the lymph vessels. Lymph vessel injury was more severe in areas where liposuction was performed transversally, vertical to the extremity's axis, than in those after a longitudinal procedure. The difference was statistically significant (p < 0.01). The volumes of adipoaspirate and of the compared regions were comparable between both groups, verified by circumference measurements. Longitudinal liposuction of the lower extremities is unlikely to cause major lesions of epifascial lymph vessels and, therefore, should be preferred in comparison to liposuction vertical to the extremity.

Pentachlorophenol exposure in women with gynecological and endocrine dysfunction

Exposure to wood preservatives containing pentachlorophenol (PCP) was detected in 65 women who consulted the Endocrinological Department of the University Hospital of Obstetrics and Gynecology, Heidelberg, Germany, because of gynecological problems. Blood PCP levels ranged from 20.7 to 133 microg per liter of serum. One hundred and six women with similar clinical conditions, corresponding age and body weight, no PCP exposure in history, and PCP levels below 20 microg per liter of serum served as control group. Significant associations were found between serum PCP concentrations, age, and different parameters of the endocrine system. PCP may act centrally on a hypothalamic or suprahypothalamic level which may result in mild ovarian and adrenal insufficiency. PCP may, therefore, play a role in the increasing infertility problem.

Efficacy of silver-coating central venous catheters in reducing bacterial colonization

OBJECTIVE

To compare silver-coated and uncoated central venous catheters regarding bacterial colonization. To assess the relative contribution of catheter hub and skin colonization to catheter tip colonization.

DESIGN

Prospective, randomized clinical trial.

SETTING

Intensive care unit in a university hospital.

PATIENTS

Patients after cardiac surgery who required a central venous double-lumen catheter (DLC).

INTERVENTIONS

Sixty-seven adult patients were prospectively randomized to receive either a silver-coated (S group, n = 34) or an uncoated control (C group, n = 33) DLC. Blood cultures were drawn at catheter removal, and removed catheters were analyzed with quantitative cultures. Typing of microorganisms included DNA fingerprinting.

MEASUREMENTS AND MAIN RESULTS

Catheters were removed if no longer necessary and aseptically divided into three segments: segment A, the catheter tip; segment B, an intermediate section; and segment C, the subcutaneous portion. Bacterial catheter colonization was quantitatively measured using sonication to detach adherent bacteria from the catheter segments in the broth and subsequent culture of an aliquot. Selected isolates of coagulase-negative staphylococci and other bacteria from catheter segments were examined by means of pulsed-field gel electrophoresis (PFGE) after macrorestriction digestion of bacterial DNA to study colonization pathogenesis. Quantitatively lower bacterial colonization could be demonstrated on the silver-coated catheters (200 +/- 550 colony forming units [CFUs]/cm catheter segment; mean +/- SD). The difference in the control catheters (1120 +/- 5350 CFUs/cm catheter segment; mean +/- SD) was not, however, significant (p = .25). The frequency of colonization of at least one catheter segment was 52.9% for the silver-coated catheters and 57.6% for the control catheters (p= .44), without any significant differences in the colonization of corresponding catheter segments. The rate of significant catheter colonization (i.e., > or = 10(3) CFUs/cm catheter by quantitative catheter culture or > or = 10(3) CFUs/mL by luminal flush) was nine in the silver group and seven in the control group, a difference that failed to reach significance (p = .41). Two patients in both groups developed catheter-related bacteremia. Pattern analysis after PFGE demonstrated that about 70% of the isolates found on the catheter tip were identical with those on the skin at the insertion site, whereas about 75% were identical with those recovered from the hub. In 29% of colonized catheters, identical bacteria were found on the hub and the skin at the insertion site.

CONCLUSIONS

Silver-coating of DLCs did not significantly reduce bacterial catheter colonization compared with the control catheters. PFGE analysis of coagulase-negative staphylococci and other bacteria demonstrated various pathogenic routes of catheter-related colonization, whereby the microorganisms of the skin flora around the insertion site must be regarded as the main source of catheter-related infections.

Biopharmaceutical characterization of oral immediate release drug products. In vitro/in vivo comparison of phenoxymethylpenicillin potassium, glimepiride and levofloxacin

The development of in vitro dissolution tests using the paddle and basket apparatus is described with respect to the qualification/validation of the testing procedure. Three examples of immediate release products containing phenoxymethylpenicillin potassium, glimepiride, and levofloxacin providing different solubility characteristics are evaluated. The solubility was high in the case of phenoxymethylpenicillin potassium and levofloxacin and low for glimepiride according to the biopharmaceutics classification system. The permeability is studied using the human colorectal carcinoma cell line CaCo-2. The permeability (10(-6) cm/s) of phenoxymethylpenicillin potassium, glimepiride, and levofloxacin was high. The determined permeability data are confirmed by absorption data obtained by means of numerical deconvolution of plasma concentrations. Recommendations are given for the biopharmaceutical characterization of the three immediate release drug products, taking into account in vitro and in vivo comparison as well as the biopharmaceutics drug classification system. The evaluated acceptance criteria are the following: phenoxymethylpenicillin potassium (80% in 30 min), glimepiride (80% in 15 min) and levofloxacin (80% in 30 min). Typically, for immediate release formulations, one limit is specified for the dissolution to ensure the release of the active ingredient within the present time period. Since phenoxymethylpenicillin potassium and levofloxacin belong to Case 1, no in vitro/in vivo correlation is expected, absorption may be gastric emptying dependent. Glimepiride is categorized to Case 2. Nevertheless, a correlation with the in vivo dissolution profile does not exist, because of the pH-dependent low solubility of the drug. Finally, recommendations are made for the batch control of drug products in accordance with the four Cases.

Biopharmaceutical characterization of oral controlled/modified-release drug products. In vitro/in vivo correlation of roxatidine

From the marketed drug product Roxane(R) 75 mg C/MR capsules (roxatidine controlled/modified-release capsules), an in vitro/in vivo comparison was performed to demonstrate a 1:1 correlation between in vitro and in vivo dissolution, and, furthermore, to ensure bioequivalence of the roxatidine controlled/modified-release (C/MR) capsules exhibiting dissolution profiles within the defined acceptance criteria. This 1:1 in vitro/in vivo comparison was calculated using a model independent numerical deconvolution method. The high degree of correlation is extremely rare, nevertheless it allows to omit the testing of clinical side batches for the setting of acceptance criteria for the in vitro dissolution of roxatidine controlled/modified-release (C/MR) capsules. The 1:1 in vitro/in vivo correlation can be explained by the biopharmaceutical characteristics of the drug substance as well as the drug product, that is, pH-independent high solubility of the drug substance as well as dissolution which is independent of pH and agitation. These facts lead to a controlled/modified-release formulation. Therefore, it is important to keep in mind that in most cases in which a pH-dependent solubility/dissolution as well as permeability characteristics can be found, a 1:1 in vitro/in vivo correlation could not be expected.

NMDA and AMPA receptors on neocortical neurons are differentially distributed

The distribution of glutamate receptor subtypes on the surface of neurons is highly relevant for synaptic activation and signal processing in the neocortex. As a novel approach we have used infra-red videomicroscopy in combination with photostimulation or microiontophoresis in brain slices of rat neocortex to map the distribution of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors on pyramidal neurons of layer V. Both modes of application revealed a spatially distinct distribution of glutamate receptor subtypes: the soma and the proximal dendrite of neurons are highly sensitive to NMDA, whereas the more distal parts of the dendrite are more sensitive to AMPA. An implication is that NMDA receptors near the soma might regulate the amplification of synaptic signals resulting from AMPA receptor activation on remote dendritic sites.

[Examination of the hand and wrist joints with a dedicated low-field MRI device]

Purpose of this study was to evaluate the diagnostic value of a low field dedicated MRI system in hand and wrist imaging. All 308 exams of the hand and wrist, that were performed on a low-field dedicated MRI system (Artoscan, Esaote Biomedica, Italy) in our institution in 1996, and high-field MRI exams performed in addition as part of the diagnostic work-up, were evaluated and correlated to final operative (n = 64) and histologic (n = 12) reports. 90% of all low-field MRI scans stated a diagnosis according to clinical suspicion. In 62% the clinical question was answered, and in 26% additional pathologies were identified. An MR-diagnosis completely different from the clinical suspicion was stated in 2%. High field exams contributed additional information in 6 of 36 patients. In 3 patients a tumor was not shown completely in the limited field-of-view of the dedicated low-field MRI-system. Frequency-selective fat-suppression pulse sequences and a better spatial resolution were the reasons for the additional information obtained in the other three patients. Low-field dedicated MR-imaging is a valuable method in the extensive work-up of the hand and wrist. Osseous, ligamentous and tendinous pathologies are well depicted. Large or infiltrative tumors should be referred to a high-field system.

[Choice of procedure in therapy of distal median nerve compression syndrome]

Endoscopic carpal tunnel release is frequently recommended. This technique allows only for division of the retinaculum flexorum, but does not enable the surgeon to address concommitant synovialitis or compression of the motor branch of the median nerve. In 67 patients, we attempted to differentiate the indications for procedures by endoscopic versus open carpal tunnel release. Beside an electrophysiological investigation, sonography of the wrist was performed to evaluate the extent of accompanying tenosynovialitis of the flexor tendons. A possible participation of the thenar branch was examined by electromyography. If there were no additional pathologic findings in the preoperative diagnostic work-up, a simple carpal tunnel release was performed. In all other cases, open surgical release was performed.

Free flap survival improved by prostacyclin analogues

Free flap transplantations and replantations of extremities are threatened by venous occlusion in the postoperative course. In rats, free autogenous groin flaps were transplanted to the neck using microsurgical techniques. On the first postoperative day, the draining vein of the flap was temporarily clamped. In the control group there was always a total loss of the flaps by haemorrhagic necrosis. The intraarterial flap perfusion by iloprost during the clamping was able to diminish the ischaemic effects; 80% of the flaps survived. The systemic application of iloprost by intravenous infusion reduced the ischaemic effects in a similar way. Serious complications such as intraabdominal bleeding or bleeding in the donor area were seen after intravenous administration. Cicaprost had a similar protective effect on flap ischaemia after intravenous infusion. Flap survival was comparable to iloprost. Severe complications seemed to be less. Prostacyclin analogues were able to diminish damage of secondary ischaemia caused by venous occlusion.

[Anus praeter--site, care and corrective possibilities]

BASIC REMARKS

The main indication for an colostomy is a carcinoma low down in the rectum. Apart from this, tumors in any part of the bowel or neighboring organs, and complications of inflammatory disease may make a diversion of feces necessary.

POINTS DISCUSSED

A stoma should be sited at a distance from skin folds, and bony protuberance, and should be readily visible for self-care. Temporary "continence" can be achieved with special stool regulatory measures (in particular irrigation), while the patient can make to with a stoma cap or a mini-bag. Many complications of stoma, in particular necrosis, parastomal hernias, prolapse, too large a stoma, stenosis and stomal recurrent tumor can usually be eliminated by surgery.

CONCLUSIONS

Today excellent possibilities of stomal care are available for a wide range of problems, which can be determined and applied in cooperation with the various specialists.