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Biomedical subjects

M Jahn

Publications and source records attributed to M Jahn.

At least 37 records · Page 2Linked to original sources
PubMed1996

Limited applicability of the DATEX Reloxograph in diabetics with peripheral polyneuropathy.

The aim of the study was to investigate whether peripheral nerve dysfunction can influence the applicability of the DATEX Relaxograph in diabetics. Sixty two patients (43 diabetics, 19 non-diabetics) undergoing ophthalmosurgical procedures under general anesthesia were tested. The distal motor latency (DML) of the ulnar nerve served as a graduation tool for peripheral nerve dysfunction. The patients were divided in three groups: non-diabetics (group 1), diabetics with DML < 3.8 msec (group 2), diabetics with DML > 3.8 msec (group 3). Relaxometry was performed by stimulating the right ulnar nerve near the wrist, and the evoked response (EMG) was obtained from the hypothenar muscle. Calibration of the device (i.e. supramaximal stimulation within the given current range of a maximum of 70 mA) was carried out successfully in most patients of group 1 and 2 (94.7% and 85.7% respectively). In contrast to that calibration could be carried out in only 40.9% of the patients of group 3 (P < 0.01 vs. group 1 and 2). Consequently in a high percentage (59.1%) of the patients of group 3 relaxometry had to be performed in an uncalibrated manner. The results substantiate the hypothesis that peripheral nerve dysfunction can restrict the applicability of the Relaxograph in diabetics.

Anesthesia, General↗
PubMed1995

Preoperative morbidity and anaesthesia-related negative events in patients undergoing conventional or laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is the standard method for surgical treatment of non-malignant gall bladder disease. Well tolerated in otherwise healthy patients, it remains however, questionable whether the laparoscopic procedure in patients with severe pre-existing morbidity is associated with a higher incidence of negative intraoperative events than open cholecystectomy. Therefore, the incidence of negative intraoperative events was prospectively investigated in a series of 1,367 patients (319 with open cholecystectomy and 1,048 with laparoscopic cholecystectomy) who were analysed for occurrence of events such as hypertension, hypotension, arrhythmia, unusual bleeding and transfusion requirement, regurgitation or aspiration of gastric content and respiratory disorders. For further analysis the patients undergoing each operative procedure were divided into two subgroups with either preoperative ASA physical status I and II or III and IV. The study groups were comparable in sex and age. There were no intraoperative deaths. The frequency of hypertension, hypotension or arrhythmia alone and in combination was similar in both groups. The need for intervention was significantly more frequent in ASA class I/II patients with laparoscopic cholecystectomy. Respiratory disorders were rare. There was a significantly higher incidence of postoperative ventilatory support in patients with conventional cholecystectomy. Transfusion was required significantly less often in patients with laparoscopic cholecystectomy (0.19% versus 15.36%). CO2-pneumoperitoneum led to severe circulatory alterations in 7 healthy patients. The most severe negative event was a cardiac arrest in 1 female patient who was successfully resuscitated without any sequelae. In ASA-class III and IV patients intraoperative negative events were equally frequent and independent of the procedure. Severe preoperative morbidity per se seems to be no contraindication for laparoscopic cholecystectomy.

Adult↗
PubMed1995

Anaesthesia for laparoscopic closure of perforated peptic ulcer--any harm or benefit?

Laparoscopic closure of perforated peptic ulcer is technically feasible (1). Haemodynamic changes during laparoscopic operations are known and may have an adverse influence on outcome in patients who have peritonitis, are hypovolemic or even septic (2-4). A complete physiological understanding of CO2-inflation of an abdomen in diffuse peritonitis is still missing. The purpose of this study is to compare perioperative variables of general anaesthesia in patients undergoing open or conventional laparoscopic closure of perforated peptic ulcer.

Abdomen↗
PubMed1994

Isolation of the hemF operon containing the gene for the Escherichia coli aerobic coproporphyrinogen III oxidase by in vivo complementation of a yeast HEM13 mutant.

Coproporphyrinogen III oxidase, an enzyme involved in heme biosynthesis, catalyzes the oxidative decarboxylation of coproporphyrinogen III to form protoporphyrinogen IX. Genetic and biochemical studies suggested the presence of two different coproporphyrinogen III oxidases, one for aerobic and one for anaerobic conditions. Here we report the cloning of the hemF gene, encoding the aerobic coproporphyrinogen III oxidase from Escherichia coli, by functional complementation of a Saccharomyces cerevisiae HEM13 mutant. An open reading frame of 897 bp encoding a protein of 299 amino acids with a calculated molecular mass of 34.3 kDa was identified. Sequence comparisons revealed 43% amino acid sequence identity with the product of the S. cerevisiae HEM13 gene and 90% identity with the product of the recently cloned Salmonella typhimurium hemF gene, while a structural relationship to the proposed anaerobic enzyme from Rhodobacter sphaeroides was not obvious. The hemF gene is in an operon with an upstream open reading frame (orf1) encoding a 31.7-kDa protein with homology to an amidase involved in cell wall metabolism. The hemF gene was mapped to 52.6 min of the E. coli chromosome. Primer extension experiments revealed a strong transcription initiation site upstream of orf1. A weak signal, possibly indicative of a second promoter, was also identified just upstream of the hemF gene. A region containing bent DNA (Bent 111), previously mapped to 52.6 min of the E. coli chromosome, was discovered in the 5' region of orf1. Two potential integration host factor binding sites were found, one close to each transcription start site. An open reading frame (orf3) transcribed in a direction opposite that of the hemF gene was found downstream of the hemF gene. It encodes a protein of 40.2 kDa that showed significant homology to proteins of the XylS/AraC family of transcriptional regulators.

Amino Acid Sequence↗