Biomedical subjects

N Günther

Publications and source records attributed to N Günther.

4 recordsLinked to original sources

PubMed2005

[Problem-based learning for surgery. Increased motivation with less teaching personnel?].

BACKGROUND: Traditional teacher-centred education strategies often do not meet the needs and student abilities of adult learning. The introduction of small learning groups requires considerable increases in staff. Problem-based learning could increase the motivation to acquire knowledge but without being as staff-intensive. METHODS: Medical students (n=98) in their fourth clinical semester were randomly assigned to either a structured course (SC) or problem-based learning (PBL) for surgery. Their motivation and acceptance of the courses were recorded at the end of term in anonymous questionnaires using Likert scales, with scores ranging from 1 (very good) to 6 (unsatisfactory). RESULTS: Both course structure and the teachers received much better ratings from the PBL students (P<0.01 each). The motivation of students to deal with surgical problems beyond the course material was significantly higher after PBL, with 1.8 (0.7), than after the structured course with 3.1 (1.2) (P<0.01). The overall rating was substantially worse for the structured course, with 3.1 (1.2) than for PBL at 1.4 (0.6) (P<0.01). CONCLUSIONS: Problem-based learning in the surgical curriculum increases student acceptance and motivation with little demand on staff. It should be increasingly implemented.

Adult↗

PubMed2003

[Changes in perioperative treatment for elective colorectal resections in Germany 1991 and 2001/2002].

BACKGROUND: To assess changes in perioperative treatment of patients undergoing elective colorectal resections, surveys were sent to all German surgical departments in 1991 and 2001/2002. METHODS: 1,207 chairmen of departments for general or visceral surgery were asked to answer a survey concerning the principles of perioperative treatment of patients undergoing elective colorectal resection. The results of this questionnaire were compared to a survey that had been performed in 1991. RESULTS: 616 chairmen (51.0%) responded to the survey (1991: 76.4%). In 2001/2002 preoperative parenteral alimentation was utilized routinely in only 10.3% (1991: 40.0%) of all hospitals. Preoperative i.v.-pyelography was used only in 24.7% of the hospitals (1991: 79.7%). Intraoperative testing of colorectal anastomoses was more common in 2001/2002 (63.7%) than in 1991 (40.1%). At the same time the incidence of "single-shot"-antibiotic prophylaxis increased from 24.0% to 70.4 %. Orthograde bowel lavage, perioperative antibiotic prophylaxis and postoperative parenteral alimentation were use as often in 2001/2002 as in 1991. Intraperitoneal drains were routinely inserted in most of the surgical departments after left-sided colonic resections (2001/2002: 86.2%; 1991: 88.2%) or rectal resections (2001/2002: 90.5%; 1991: 94.4%). CONCLUSION: During the last decade, perioperative therapy for patients undergoing elective colorectal resection has changed substantially. Most of these changes occurred in the perioperative medical treatment. However, surgical traditions like intraperitoneal drainage are still very frequently utilized.

Anastomosis, Surgical↗

PubMed1994

Protein microheterogeneity and crystal habits: the case of epidermal growth factor receptor isoforms as isolated in a multicompartment electrolyzer with isoelectric membranes.

A purified, soluble form of the epidermal growth factor receptor (sEGFR) was found, by isoelectric focusing in immobilized pH gradients, to consist of three major isoforms (with pI values 6.45, 6.71 and 6.96, respectively) and ca. a dozen minor components. This wild-type sEGFR, while producing crystals, has so far defied any attempt at decoding the structure, due to the very poor diffraction pattern. When the wild-type sEGFR was purified in a multicompartment electrolyzer with isoelectric Immobiline membranes, it yielded the three major isoforms as single-pI components, collected in three separate chambers of the recycling electrolyzer. The pI 6.71 and the pI 6.96 isoforms produced large crystals of apparent good quality. However, while the former produced a high-quality diffraction pattern, which may lead to decoding of three-dimensional structure, the pI 6.96 produced crystals which did not diffract at all. It is concluded that, in the case of "tough" proteins (large size, heterogeneous glycosylation, high water content of crystals), purification to single-charge components might be an essential step for growing proper crystals. The unique advantage of purification via isoelectric membranes is that the protein is collected both isoelectric and isoionic, i.e. uncontaminated by soluble buffers (such as the carrier ampholytes used in conventional focusing).

Animals↗

PubMed1990

The secreted form of the epidermal growth factor receptor. Characterization and crystallization of the receptor-ligand complex.

A protein composed of the external domain of the epidermal growth factor (EGF) receptor is secreted by A431 human tumor cells. The soluble receptor protein was isolated in bulk quantities from cell culture supernatants. It has an intact ligand binding site, exists in a 93-kDa monomeric form, and does not undergo oligomerization upon ligand binding; thus the receptor dimerization reported for the EGF holoreceptor appears not to be a function of its external domain. The unique system of a physiological soluble receptor was utilized for a crystallization study. Crystals were obtained but only in the presence of the ligand. They contained (in equimolar amounts) receptor as well as EGF. The crystals belong to the tetragonal space group P4(3)2(1)2 or P4(1)2(1)2 with unit cell dimensions a = b = 118 A, c = 202 A. The packing density parameter was 3.55 A3/dalton, indicating the asymmetric unit to consist of one receptor-ligand complex.

Cell Line↗