Cyclic voltammetry, square wave voltammetry or electrochemical impedance spectroscopy? Interrogating electrochemical approaches for the determination of electron transfer rates of immobilized redox proteins.

In this article, we cross-examine three well-established electrochemical approaches, namely cyclic voltammetry (CV), cyclic square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) to dissect the electron transfer (ET) rate of electrostatically immobilized cytochrome c on Ag electrodes. A detailed analysis supported by simulations of redox transition provided three distinct values for the heterogeneous electron transfer (HET) rate constant of cyt c interfaced on COOH-terminated C10-long alkanethiol, i.e., kHET= 47.8 (±2,91) s-1 in CV, kHET= 64.8 (±1,27) s-1 in SWV, and kHET= 26.5 s-1 in EIS. We discuss the obtained discrepancies obtained from electrochemical methods and compare them with the data from spectro-electrochemical experiments. A comprehensive selection list is created from which the most applicable approach can be chosen for studying proteins of interest. CV is most applicable to study the interfaced proteins exhibiting kHET of ca. 0.5 - 70 s-1, SWV is suitable for a broader range of kHET of 5 - 120 s-1 and EIS for kHET of 0.5 to 5 s-1 if alkanethiols are used as immobilization strategy.

[Structured teaching of surgery the LMU model in Munich]. / Strukturierte Lehre in der Chirurgie am Beispiel des Humanmedizinstudiums an der Ludwig-Maximilians-Universität München.

The medical curriculum (MeCuM) of the Ludwig Maximilian University (LMU) in Munich is a dynamic curriculum aimed to support the learning process of all students with their different learning styles. It is based on interactive, activating teaching methods in order to increase students' interest, and on repetitive evaluation of teaching units to modify the teaching in order to meet students' needs and wishes. In this context the teaching of surgery at our faculty takes place. Besides interdisciplinary lessons where diseases are taught in cooperation with our colleagues from internal medicine, indications for surgery, complications and consequences of surgery for the patients are analysed in PBL tutorials, online cases, bedside teachings and practical teaching on the ward. Surgical skills like suturing are demonstrated in videos, practiced on models or during practical teaching on the ward and they are tested in OSCEs. During the "praktisches Jahr", the students in the last year of their medical studies are supposed to apply their practical skills besides repeating theoretical knowledge in order to pass the final examination. For this purpose they are taught in a revision course called "LMU-StaR" (revision course for the Staatsexamen). In this paper we describe in detail the teaching of surgery at our faculty.

Early graft function in kidney transplantation: comparison between laparoscopic donor nephrectomy and open donor nephrectomy.

Laparoscopic donor nephrectomy (LN) offers less postoperative pain and early recovery in living kidney donors, but graft kidney function in the recipients can be delayed due to prolonged warm ischemic time (WIT) and adverse effects of pneumoperitoneum. We compared the early function of the grafted kidney and the complications in kidney recipients after LN versus open nephrectomy (ON). We analyzed 109 kidney recipients from living donors, including 60 LN and 49 ON, comparing immediate diuresis after surgery, glomerular filtration rate (GFR) by MDRD formula (modification of diet in renal disease) at day 5, and complications. The recipient age among the LN group was 20 to 73 years with 51% men among whom 95% of patients had immediate diuresis with GFR at day 5 varying from 4.85 to 99.45 mL/min/1.73 m(2) by MDRD Surgical complications were renal artery stenosis (5%) and urinary leakage (5%). The recipient among age ON cases varied from 18 to 63 years with 63% men and immediate diuresis observed in 87% and GFR at day 5 varied from 4.75 to 101.1 mL/min/1.73 m(2) by MDRD. Renal artery stenosis was observed in 8.16%. The WIT was longer (P < .05) among the LN (1.4 to 11 minutes) compared with the ON group (1 to 4 minutes). GFR at day 5 showed no difference between the two groups. In conclusion, WIT was higher among LN compared with ON but did not seem to influence early function of the grafted kidney.

Hand-assisted laparoscopic donor nephrectomy: comparison to pure laparoscopic donor nephrectomy.

Hand-assisted laparoscopic surgery is assumed to be easier to learn than the standard approach and simplifies intact kidney removal. Herein we have presented our experience performing hand-assisted laparoscopic donor nephrectomy (HALDN) compared with contemporary pure laparoscopic donor nephrectomy (LDN). We retrospectively analyzed 55 patients who underwent LDN. Among the procedures, 21 were HALDN and 34 were pure LDN. We compared the two groups with regard to operative time, warm ischemic time (WIT), estimated blood loss, conversion rate, postoperative stay, and complications. For the HALDN group, the mean operative time was 191 minutes, WIT varied from 2 to 11 minutes, and bleeding estimates varied from 100 to 4000 mL. The overall complication rate of 28.6% included: vessel injury, urinary leakage, and paralytic ileus. In the LDN group, the mean operative time was 184 minutes, WIT varied from 2 to 10 minutes, and bleeding estimated varied 100 to 3000 mL. Three patients (8.8%) had complications including ureteral obstruction (n = 1) and vessel injury (n = 2). There was no significant difference between the two groups about the procedure and the complications. Our series suggested that HALDN and LDN were similar, with a tendency toward better results in LDN group, which also shows lower costs.

[Fractures of the distal radius. Minimally invasive pin fixation: indications and results]. / Der distale Speichenbruch. Minimalinvasive Kirschnerdrahtosteosynthese. Indikation und Ergebnisse.

Therapy of distal radius fractures in the elderly is increasingly subject to higher demands on functional results, especially in terms of patient comfort, load-bearing, tissue atrophy, and osteoporosis. From 1 January 1998 until 30 June 1999, 215 patients with distal radius fractures were treated at our hospital. One hundred eighteen of them had follow-up examinations after an average of 33 months. Using objective criteria (X-ray and functional), results were very good in 68.9% of the cases and good in 28.6%. Under subjective criteria, too, most of the patients had very little or no complaints (68%). These results underline the need and usefulness of differentiating operative therapies according to the fracture type in the AO classification system.

[Diagnostic laparoscopy and laparoscopic appendectomy in the diagnosis and therapy concept of abdominal pain of unknown origin]. / Diagnostische Laparoskopie und laparoskopische Appendektomie im Diagnostik- und Therapiekonzept des unklaren Unterbauchschmerzes.

The unclear lower abdominal pain can be problematic for the surgeon although modern diagnostics and technical equipment are applied. We present the experiences in a retrospective study carried out in our hospital since beginning of laparoscopy in unclear lower abdominal pain. The laparoscopic diagnostic provides valuable additional informations for the further treatment. We can get important informations about differential diagnosis of appendicitis, especially of young women and old patients. The laparoscopy as a minimal invasive diagnostics goes together with a high benefit for the patients and a low rate of complications.

[Appendectomy with respect to flat fee and special rate charges. Cost analysis of open and laparoscopic operation]. / Die Appendektomie unter den Bedingungen von Fallpauschale und Sonderentgelt. Kostenanalyse bei offener und laparoskopischer Operation.

The introduction of flat charges per case and special fees, first put into effect on Jan. 1, 1996, has lead medical and administrative personnel to rethink how fixed daily hospital rates, costs individually determined by each hospital, and prime costs for hospital and nursing charges will be reimbursed. The amount paid for flat charge cases and special fees (in German Marks) are currently the same nationwide. This applicable system of billing consists of a combination of diagnosis (ICD 9) and the type of therapy administered after each specific operation (ICPM). Between Jan. 1, 1996 and Dec. 31, 1996 we had 78 cases, where detailed personnel and relevant costs were recorded with the aid of three sheets of medical records and two reports for each patient. When comparing expenditures and compensation, there were deficits in 75 cases and surpluses in 3. This existing pressure to cut costs should not be allowed to lead to uncritical medical judgement. The major costs of an operation are for disposable materials, especially for the use of the endo-cutter. Laparoscopic appendectomies, on selected patients in our clinic, has created a deficit when covering costs for open appendectomies. The knowledge we have gained from this now enables us to balance out the deficit.

Analysis of the polyphosphate-accumulating microflora in phosphorus-eliminating, anaerobic-aerobic activated sludge systems by using diaminopropane as a biomarker for rapid estimation of Acinetobacter spp.

Polyphosphate-accumulating gram-negative bacteria were isolated from different anaerobic-aerobic activated sludge systems with diverse processes for enhanced biological phosphorus (P) elimination. Of 22 isolates, 10 were allocated to the genus Acinetobacter by using multiple-test systems and soluble protein and polyamine patterns. As diaminopropane (DAP) appears to be the characteristic main polyamine compound produced by Acinetobacter spp., it was used as a biomarker for the genus. The high DAP contents of representative samples from municipal wastes with enhanced biological P elimination indicated that Acinetobacter spp. can be dominant organisms in sewage treatment plants with low organic loading and nitrification and denitrification steps. Contrary to accepted opinion, sludge from treatment plants with efficient P removal and high organic loading had a low DAP content, indicating that bacteria other than Acinetobacter spp. are responsible for enhanced biological P elimination in these plants.

[Sports injuries of the face]. / Les traumas sportifs de la face.

Of 249 patients with facial injuries admitted to the Department of Stomatology and Maxillofacial Surgery, Hôpital Bel Air, Thionville, France, between 1981 and 1982, 45 (18%) were cases of injury from sporting activities. The particular characteristics of the latter lesions were their predominance in males, their increased seasonal frequency in spring and early summer, the high incidence of damage to the nasal pyramid and maxillomalar complex, and the fact that the most implicated sport was football (71% of cases). Whereas most accidents resulted in relatively minor lesions, three cases--including two from riding--involved severe, complex injuries comparable to those seen in certain car accidents. Findings in this series confirm the natural "bumper" property of the face. Emphasis is placed on the importance of well-conducted training, and the need to eliminate consideration of sport as a means for expressing aggressiveness that is not always possible in daily life.