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Biomedical subjects

A Grimm

Publications and source records attributed to A Grimm.

14 recordsLinked to original sources
PubMed2006

Spectroscopic investigation of the deeply buried Cu(In,Ga)(S,Se)2/Mo interface in thin-film solar cells.

The Cu(In,Ga)(S,Se)(2)Mo interface in thin-film solar cells has been investigated by surface-sensitive photoelectron spectroscopy, bulk-sensitive x-ray emission spectroscopy, and atomic force microscopy. It is possible to access this deeply buried interface by using a suitable lift-off technique, which allows us to investigate the back side of the absorber layer as well as the front side of the Mo back contact. We find a layer of Mo(S,Se)(2) on the surface of the Mo back contact and a copper-poor stoichiometry at the back side of the Cu(In,Ga)(S,Se)(2) absorber. Furthermore, we observe that the Na content at the Cu(In,Ga)(S,Se)(2)Mo interface as well as at the inner grain boundaries in the back contact region is significantly lower than at the absorber front surface.

Journal Article↗
PubMed2006

[Optimizing vacuum therapy in extensively undermined wounds].

INTRODUCTION: Extensively undermined wound cavities represent a common surgical problem. By a modified vacuum therapy the healing of such wounds can be accelerated. MATERIALS AND METHODS: Based on our experience in selected cases with wound healing disorders or extremely undermined wounds following degloving injuries or abscess formations the application of topical negative pressure therapy to fix wound margins to the wound ground while at the same time allowing exudates emission with additional drainages is described. RESULTS: In 5 patients we were able to demonstrate the efficacy of vacuum dressing system described here with successful and lasting adaptation of the wound margins to the defect. All wounds were brought to permanent healing. CONCLUSION: Extensive tissue degloving and wound healing disorders after excessive tissue mobilization during plastic surgical defect coverage can be treated successfully with topical negative pressure therapy (TNP). Whereas longterm complete conventional polyurethane foam lining of wound cavities is an effective method and may be necessary in special situations, the application of TNP can lead to a firm adhesion of wound margins in extensive subcutaneous or epi-fascial wounds to the undersurface. To avoid exudate formation in the adjoining tissue TNP can be effectively optimized by the placement of drainage tubes into the surrounding tissue.

Abdominal Wall↗
PubMed2004

Progression and distribution of plantar pressure in Type 2 diabetic patients.

The aim of this prospective 4-yr study was to analyse changes in mean plantar pressure (PP) over time and local shifts of maximal PP in Type 2 diabetic patients. One-hundred fifty-five Type 2 diabetic patients (age 58.9 +/- 7.5 yr, diabetes duration 11.0 +/- 7.6 yr, baseline HbA1c 9.6 +/- 1.6%) were examined with regard to foot abnormalities, neuropathy and measurement of PP during walking (pedobarography). They were assigned to two subgroups, namely normal PP (n=94) and elevated PP (n=57). Patients with an abnormal mean PP did not significantly differ from subjects with a normal PP with regard to sex, age, duration of diabetes and HbA1c. With the exception of the hallux, the mean PP was significantly increased in both groups at all other plantar sites. Maximum PP was located below the metatarsal heads (MTH) 2-5 and significantly increased from baseline (median, lower/upper quartile: 475, 355/715 kPa) to the end of the study (540, 435/749; p<0.0001). On the other hand, PP was normalized in 17 subjects (29.8%) who had an elevated PP at baseline. Furthermore, we observed a local shift in maximal PP towards the MTH 2-5 region. The percentage of patients who had their highest PP under MTH 2-5 was increased from 54.0% at baseline to 61.1% at the end of the study. In general, we registered an elevation of PP over time and a centralization towards sites which are generally prone to ulceration.

Diabetes Mellitus, Type 2↗
PubMed2000

Drosophila atypical protein kinase C associates with Bazooka and controls polarity of epithelia and neuroblasts.

The establishment and maintenance of polarity is of fundamental importance for the function of epithelial and neuronal cells. In Drosophila, the multi-PDZ domain protein Bazooka (Baz) is required for establishment of apico-basal polarity in epithelia and in neuroblasts, the stem cells of the central nervous system. In the latter, Baz anchors Inscuteable in the apical cytocortex, which is essential for asymmetric localization of cell fate determinants and for proper orientation of the mitotic spindle. Here we show that Baz directly binds to the Drosophila atypical isoform of protein kinase C and that both proteins are mutually dependent on each other for correct apical localization. Loss-of-function mutants of the Drosophila atypical isoform of PKC show loss of apico-basal polarity, multilayering of epithelia, mislocalization of Inscuteable and abnormal spindle orientation in neuroblasts. Together, these data provide strong evidence for the existence of an evolutionary conserved mechanism that controls apico-basal polarity in epithelia and neuronal stem cells. This study is the first functional analysis of an atypical protein kinase C isoform using a loss-of-function allele in a genetically tractable organism.

Animals↗
PubMed2000

Influence of volatile and intravenous anesthetics on the threshold of the acoustically evoked stapedius reflex.

The influence of volatile and intravenous anesthetics on the threshold of the acoustically evoked stapedius reflex (SR) was studied prospectively in 45 patients undergoing elective ENT surgical procedures. After premedication with flunitrazepam the patients were randomly assigned to one of nine groups. Group I: 70% nitrous oxide (N2O) in oxygen (O2); Groups II-VII: induction of anesthesia with intravenous thiopental, followed by mask inhalation with 100% O2 and 1.13% halothane (Group II), 2.52% enflurane (Group III) or 1.73% isoflurane (Group IV); or 70% N2O in oxygen, and 0.44% halothane (Group V), 0.86% enflurane (Group VI) or 0.75% isoflurane (Group VII): Group VIII: intravenous midazolam and ketamine; and Group IX: intravenous midazolam and alfentanil. Tympanometry and ipsilateral and contralateral SR measurements were performed when the effects of the anesthetics had achieved a steady state. Flunitrazepam raised the SR threshold only slightly. Substances applied during inhalation anesthesia either markedly increased the threshold contralaterally more than ipsilaterally (thiopental, N2O), or suppressed the reflex completely (thiopental, all volatile anesthetics with or without N2O). Under intravenous anesthesia the reflex was always present. The midazolam-ketamine combination influenced the threshold bilaterally only slightly, while the midazolam-alfentanil combination led to a pronounced, contralaterally significant elevation of the threshold. Based on its minimal influence on the SR threshold, flunitrazepam is especially suitable for sedation and the midazolam-ketamine combination for anesthesia in audiological diagnostic procedures.

Acoustic Impedance Tests↗
PubMed2000

Child care work. Organizational culture and health and safety.

A nonrandom sample of child care workers was surveyed to assess whether child care work represented an "at risk" health and safety culture and to measure the organizational dimensions contributing to the health and safety culture. The child care workers in Houston, Texas, were surveyed by mail, using an instrument developed by the research team. The sample population represented 34 child care centers (n = 240 respondents). The analysis yielded five factors related to determinants of health and safety culture. The participants had a favorable perception of the five health and safety determinants. The participants also reported high levels of injury and illness in their environments, suggesting a less than favorable situation. A culture, work, and health model was useful in examining the relationship between health and safety and organizational culture.

Absenteeism↗
PubMed1996

Purification and characterization of the DNA-binding protein DnrI, a transcriptional factor of daunorubicin biosynthesis in Streptomyces peucetius.

The DnrI protein, essential for the biosynthesis of daunorubicin in Streptomyces peucetius, was purified almost to homogeneity from dnrI expression strains of Escherichia coll and S. peucetius through several steps of chromatography. The proteins purified from both organisms had identical chromatographic and electrophoretic behaviour. Purified Histagged or native DnrI was used to conduct DNA-binding assays by gel mobility-shift analysis, and the results showed no significant difference in the DNA-binding activity of native or His-tagged proteins. DnrI binds specifically to DNA segments containing the intergenic regions separating the putative dnrG-dpsABCD and dpsEF operons, and the dnrC gene and dnrDKPSQ operon. DNase I footprinting assays indicated that the DNA-binding sites for DnrI extended from upstream of the -10 to -35 regions of the dnrG or dpsE promoters to include about 65 bp of the dnrG-dpsE intergenic region and about 80 bp of the dnrC-dnrD intergenic region. Both binding sites contain imperfect inverted repeat sequences of 6-10 bp with a 5'-TCGAG-3' consensus sequence that was present in 4 out of 10 other promoter regions in the cluster of daunorubicin biosynthesis genes.

Base Sequence↗
PubMed1994

Characterization of the Streptomyces peucetius ATCC 29050 genes encoding doxorubicin polyketide synthase.

The dps genes of Streptomyces peucetius, encoding daunorubicin (DNR)-doxorubicin (DXR) polyketide synthase (PKS), are largely within an 8.7-kb region of DNA that has been characterized by Southern analysis, and gene sequencing, mutagenesis and expression experiments. This region contains nine ORFs, many of whose predicted products are homologous to known PKS enzymes. Surprisingly, the gene encoding the DXR PKS acyl carrier protein is not in this region, but is located about 10 kb distant from the position it usually occupies in other gene clusters encoding type-II PKS. An in-frame deletion in the dpsB gene, encoding a putative subunit of the DXR PKS, resulted in loss of production of DXR and the known intermediates of its biosynthetic pathway, confirming that this gene and, by implication, the adjacent dps genes are required for DXR biosynthesis. This was verified by expression of the dps genes in the heterologous host, Streptomyces lividans, which resulted in the production of aklanonic acid, an early intermediate of DXR biosynthesis.

Amino Acid Sequence↗
PubMed1994

[Late results of implantation of dual head prostheses in hip para-articular fractures].

In the hospital of Aalen through the years 1985 to 1993 a total of 545 patients have been treated by using a "Duokopf"-prosthesis. The average age was 82.6 years. In a retrospective study the mobility and survival rate after surgery of 109 patients, who had undergone such treatment because of a hip fracture, were found out. The survival rate one year after surgery was within the range of the survival rate of the normal population at that age: The evaluation of the mobility one year after implantation with 57% surviving patients, who are able to walk without aid is a good result. None of the patients showed a protrusio acetabuli. Although the evaluation of the presented results is limited, since, due to the high average age, the mortality rate after surgery was extreme, the Duokopf prosthesis has proved to bring up good long term results.

Aged↗
PubMed1980

Islet glutathione and insulin release.

In isolated rat pancreatic islets, glucose (5.6, 11.1, and 16.7 mM) significantly increased reduced glutathione (GSH) and decreased oxidized glutathione (GSSG) levels in a dose-related manner. This was paralleled by a concomitant increase of NADPH and a decrease of NADP. The change of the GSH level occurred as quickly as one minute after addition of glucose. Exogenous insulin (200, 400, and 800 microU/ml) significantly decreased islet GSH levels in the presence of 5.6 and 16.7 mM glucose and significantly inhibited the insulin-releasing effect of the thiol reagent parachloromercuribenzoate (p-CMB) and tolbutamide. These data, together with earlier observations, suggest that GSH levels in pancreatic islets are increased by glucose and decreased by exogenous insulin via their effects on the pentose phosphate shunt and NADPH. Our results are compatible with the hypothesis that glucose and exogenous insulin, by modifying the redox state of the NADPH/NADP and GSH/GSSG systems, modulate the sensitivity of the beta-cell to the insulin-triggering actions of glucose, p-CMB, and tolbutamide.

Animals↗
PubMed1979

Effect of methylene blue and thiol oxidants on pancreatic islet GSH/GSSG ratios and tolbutamide mediated insulin release in vitro.

Methylene blue (an oxidant of NADPH), diamide (an oxidant of glutathion-SH [GSH]) and tertbutyl hydroperoxide (a substrate of glutathione peroxidase) significantly decreased the GSH content of pancreatic rat islets and decreased their GSH/GSSG ratio. They also significantly depressed the single peak insulin response to tolbutamide by the isolated perfused pancreas as well as its synergistic action with glucose in isolated pancreatic islets. These results suggest that the effect of tolbutamide alone and its synergistic action with glucose could depend on the islet NADPH and GSH. In addition it appears that augmentation of tolbutamide action by glucose in insulin release is mediated by the provision of additional NADPH and GSH through glucose metabolism.

Animals↗
PubMedDate not supplied

[Child abuse].

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Child↗