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Biomedical subjects

M Baer

Publications and source records attributed to M Baer.

72 records · Page 4Linked to original sources
PubMed1985

A catalytic RNA and its gene from Salmonella typhimurium.

The gene for the RNA subunit (M1 RNA) of ribonuclease P from Salmonella typhimurium directs the synthesis of an RNA that can cleave transfer RNA precursor molecules. The mature M1 RNA coded for by Salmonella typhimurium is 375 nucleotides long and has six nucleotide changes in comparison to M1 RNA from Escherichia coli. The regions for promotion and termination of transcription are closely conserved, but adjacent regions of nucleotide sequences show considerable drift.

Base Sequence↗
PubMed1985

[Systematic preoperative phlebography in patients with leg injuries, surgically treated after a delay].

Post-traumatic preoperative deep vein thrombosis (DVT) was studied by routine bilateral venography in 98 orthopaedic patients admitted more than 48 h (mean: 7 days) after the limb trauma, who had not been given prophylactic anticoagulation. All these patients had undergone long distance travel under medical supervision, having been injured a long way from the medical centre. Ages ranged from 15 to 77 years (mean age: 38 years). 85 patients had been previously free of any of the usual risk factors for DVT. Routine venography showed up DVT in 39 patients (40%). Four DVT were bilateral; only seven were symptomatic. When DVT was proved, heparin treatment by infusion pump was given for 15 days before surgery was performed.

Adolescent↗
PubMed1984

Inhibition of thrombus formation on intravascular sensors by electrical polarization.

Implantable biomedical sensors built on a silicon substrate capped with glass are currently being developed for intravascular applications. Electrical techniques for inhibiting thrombus formation on the surface of a proposed optical sensor in direct contact with blood have been investigated. Glass-on-silicon specimens (4 X 1.2 X 0.4 mm3) were coated with indium-tin oxide, a transparent conductor, and implanted in the vena cava and iliac veins of three dogs for 10, 20, or 33 days. The equilibrium surface-blood interface potentials of the specimens were modified by implanted current sources which supplied either direct current (8-15 microA) or 100 KHz alternating current (5 microA, root mean square). Light-microscopic and scanning electron-microscopic analyses showed each of the DC-polarized specimens to be free of thrombus, in contrast to nonpolarized (control) specimens on which varying amounts of adsorbed protein and thrombus deposits were found. Like the control specimens, the AC-polarized specimens formed thrombus, but the appearance of the deposits differed. These findings support the view that the polarity, magnitude and time dependence of the potential across conducting surface-blood interface significantly influence thrombogenicity. Further work is necessary to determine the roles of electrochemical and electrostatic factors in preventing thrombus formation on foreign materials.

Animals↗
PubMed1984

Audiological and vestibular findings in 219 cases of meningitis.

The audiological and electronystagmographic follow-up results of 219 children with different forms of meningitis are presented. The findings for hearing loss are roughly comparable with those of earlier reports. There have been no previous systematic studies on children with meningitis. Our electronystagmographic results show continuous nystagmus, evenly distributed in different aetiological groups, in 26 patients (12%), directional preponderance in 11 patients (5%) and canal paresis in three patients (1.5%). Disconjugate eye movements indicating a possible brain-stem lesion were observed in seven patients (3%). Eye movements were registered individually for both eyes. None of our patients had clinically significant vertigo. The electronystagmographic findings did not appear with hearing loss, indicating that vestibular disorders may develop independently. Our results support the view that electronystagmography should be performed routinely on every child who has had meningitis.

Audiometry↗
PubMed1984

Pseudomembranous colitis with recurring diarrhoea and prolonged persistence of Clostridium difficile in a 10-year-old girl.

A 10-year-old girl developed, after treatment with amyxocillin, a clinically and sigmoidoscopically apparent pseudomembranous colitis with positive Clostridium difficile stool culture. Treatment with vancomycin resulted in rapid clinical cure, but there was a relapse of diarrhoea and reappearance of C. difficile, with no pseudomembranous colitis, within one month. Clinical symptoms subsided spontaneously but C. difficile persisted for 2 more months in the stools. This case reflects three different aspects of C. difficile infection in one child: pseudomembranous colitis, ordinary diarrhoea, and symptomless carrier state.

Amoxicillin↗
PubMed1981

[Our experiences during cannulation of the subclavian vein in children (author's transl)].

With 260 children under 12 years of age we tried to cannulate the subclavian vein during 3 years 455 times, and were successful 391 times (85.9%). 43.8% of the patients were younger than 1 year. The success rate correlated to the childrens' bodyweight and was less with lower weight of the patients. - In 68.8% of the cases we found the tip of the cannula in the upper caval vein, 19.9% were in the internal jugular vein, and 6.1% were in the opposite subclavian vein. - In this study participated 7 members of the staff and 8 specializing doctors; catheterizations per participant, mean = 30,2, SD 21,49, minimum 6, maximum 65. - Cannulas functioned for 5 +/- 2, max. 19 days. - The most serious complications were 2 pneumo- and one pneumo-hydrothorax, 2 times suspicion of thrombosis and 1 hemorrhage due to a not known hemophilia. None of the complications caused therapeutical problems.

Body Weight↗
PubMed1979

Regulation of the biosynthesis of aminoacyl-transfer ribonucleic acid synthetases and of transfer ribonucleic acid in Escherichia coli. V. Mutants with increased levels of valyl-transfer ribonucleic acid synthetase.

Spontaneous revertants of a temperature-sensitive Escherichia coli strain harboring a thermolabile valyl-transfer ribonucleic acid (tRNA) synthetase were selected for growth at 40 degrees C. Of these, a large number still contain the thermolabile valyl-tRNA synthetase. Three of these revertants contained an increased level of the thermolabile enzyme. The genetic locus, valX, responsible for the enzyme overproduction, is adjacent to the structural gene, valS, of valyl-tRNA synthetase. Determination (by radioimmunoassay) of the turnover rates of valyl-tRNA synthetase showed that the increased level of valyl-tRNA synthetase is due to new enzyme synthesis rather than decreased rates of protein degradation.

Amino Acyl-tRNA Synthetases↗
PubMedDate not supplied

Esophagitis and findings of long-term esophageal pH recording in children with repeated lower respiratory tract symptoms.

Esophagoscopy was performed on 116 children with recurrent lower respiratory tract symptoms; esophagitis of various degrees was detected in 45% of the cases. The presence of verified esophagitis correlated with endoscopic findings of bile-stained gastric contents, suggesting a role of bile reflux in the pathogenesis. Esophageal pH recordings covering an 18-24-h period were performed on 22 patients with esophagitis and 19 patients without esophagitis. Gastroesophageal reflux (GER) during the sleeping period was detected in 95% of children with esophagitis, as compared to 42% in children with no esophagitis (p less than 0.001). The percentage of time with esophageal pH below 4 of the total registration time was significantly greater (p less than 0.05) in children with esophagitis (9.5%) than in those with no esophagitis (4.0%)--the difference being due to a greater share of nocturnal GER of the recording time. These criteria could be applied to a search for clinically significant GER in children with recurrent lower respiratory tract symptoms and to select patients for esophagoscopy.

Adolescent↗