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Biomedical subjects

M Meyer

Publications and source records attributed to M Meyer.

At least 685 records · Page 38Linked to original sources
PubMed1978

[Eye movement disorder in albinos (author's transl)].

Recent studies have shown misdirected optic fibres in albinotic animals to the lateral geniculate body, to the visual cortex and to the superior colliculi. Since a similar anomaly was found anatomiclly and neurophysiologically in human albinos, an oculography was performed in 10 albinos. The results were identical to those found in the so called congenital nystagmus. It remains doubtful that the misdirection is an explanation for the nystagmus in albinotic humans.

Adult↗
PubMed1978

[Congenital cyst of the common hepatic duct. Adenocarcinoma of the gall bladder and of the stomach (author's transl)].

The authors report an unusual case of coexistence in the same patient of a congenital cyst of the common bile duct, a mucous adenocarcinoma of the stomach and a gall bladder adenocarcinoma. There was a favourable short term course after gastrectomy, cholecystectomy and resection of the cyst followed by bilio-digestive anastomosis on a long jejunal Y-shaped loop. The authors review recent literature.

Adenocarcinoma↗
PubMed1977

Synthesis and anti-inflammatory activity of 3,3a-dihydro-2H,9H-isoxazolo [3,2-b] [1,3]benzoxazin-9-ones and related compounds.

A series of 3,3a-dihydro-2H,9H-isoxazolo[3,2-b]-[1,3]benzoxazin-9-ones was synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. Since many of these compounds exhibited promising activity, particularly in the anti-inflammatory tests, a number of homologous 2,3,4,4a-tetrahydro-10H-1,2-oxazino[3,2-b]-[1,3]benzoxazin-10-ones and one 3,4,5,5a-tetrahydro-2H, 11H,-1,2-oxazepino [3,2-b][1,3]benzoxazin-11-one, the 9-chloro analog, were also prepared and evaluated. The expanded ring members were generally less active than the tricyclic compounds containing the isoxazolidine ring.

Animals↗
PubMed1977

Oxygen affinity of duck blood determined by in vivo and in vitro technique.

Half saturation partial pressure of O2,P50, was determined in domestic Muscovy ducks (Cairina moschata) both by in vivo and in vitro techniques. For in vivo determination, blood samples were drawn from the anesthetized, artificially ventilated animals and analyzed both for O2 content, Co2, and O2 partial pressure, Po2. O2 capacity was detemined in arterial samples during hyperoxic ventilation (arterial Po2 about 180 torr). P50 was calculated from measurements in venous blood samples (O2 saturation near 50%). For in vitro determinations, Co2 was measured in blood samples equilibrated with Po2 close to P50. No significant difference was found between P50 values determined by both techniques. At 41 C and pH 7.50, P50 averaged 41.7 torr when analyzed by in vivo technique and 41.4 torr when determined in vitro. The variability between animals was less than 1 torr (SD) and could be explained by the experimental error. The partially discordant literature data on P50 of duck blood are reviewed and critically discussed.

Animals↗
PubMed1977

Respiration and circulation during swimming activity in the dogfish Scyliorhinus stellaris.

A number of respiratory and circulatory parameters was measured in the Larger Spotted Dogfish Scyliorhinus stellaris before, during and after periods of spontaneous swimming. During swimming the gill ventilation was increased, mainly due to increased ventilatory stroke volume, the respiratory frequency showing a small rise only, and the cardiac output was increased at only slightly elevated cardiac frequency. Coordination between cardiac, ventilatory or locomotor (tail-beat) rhythms was not observed. The decrease in utilization of inspired water O2 during swimming was attributable to diffusion limitation in branchial O2 transfer. A considerable fraction of the total net amount of O2 required for swimming was taken up during the recovery phase. From the observations that (1) the decrease in gill ventilatory flow after cessation of swimming revealed a very rapid component (followed by a slow component), and that (2) changes in swimming speed were reflected by immediate changes in momentary ventilatory flow, it is concluded that the increased ventilation during swimming was in part mechanical-passive and/or due to nervous coupling between respiratory and locomotor centers.

Animals↗
PubMed1977

Automated microbiological detection/identification system.

An automated, computerized system, the AutoMicrobic System, has been developed for the detection, enumeration, and identification of bacteria and yeasts in clinical specimens. The biological basis for the system resides in lyophilized, highly selective and specific media enclosed in wells of a disposable plastic cuvette; introduction of a suitable specimen rehydrates and inoculates the media in the wells. An automated optical system monitors, and the computer interprets, changes in the media, with enumeration and identification results automatically obtained in 13 h. Sixteen different selective media were developed and tested with a variety of seeded (simulated) and clinical specimens. The AutoMicrobic System has been extensively tested with urine specimens, using a urine test kit (Identi-Pak) that contains selective media for Escherichia coli, Proteus species, Pseudomonas aeruginosa, Klebsiella-Enterobacter species, Serratia species, Citrobacter freundii, group D enterococci, Staphylococcus aureus, and yeasts (Candida species and Torulopsis glabrata). The system has been tested with 3,370 seeded urine specimens and 1,486 clinical urines. Agreement with simultaneous conventional (manual) cultures, at levels of 70,000 colony-forming units per ml (or more), was 92% or better for seeded specimens; clinical specimens yielded results of 93% or better for all organisms except P. aeruginosa, where agreement was 86%. System expansion in progress includes antibiotic susceptibility testing and compatibility with most types of clinical specimens.

Bacteria↗
PubMed1977

[Clinical signs of the narrow lumbar spinal canal (author's transl)].

The syndrom of the narrow spinal canal is today to be separated from other lumbar diseases by its nosological entity. It starts slowly and becomes manifest in middle and advanced age. Claudicatio intermittens is the characteristic symptom of this disease the aetiology of which is multifactory. Most patients show in the myelogram konstitutionell alterations combined with localized or generalized degenerative narrowing of the spinal canal. The clinical findings correspond to the lumbar segments affected. With localized narrowing the differential diagnosis of disc herniation is generally possible by myelography. This is of therapeutic consequence because in this cases a removal of the disc is unnecessary.

Adult↗
PubMed1976

Significance of folded chromosomes released from amino-acid-starved Escherichia coli cells.

1. Folded chromosomes from amino-acid-starved Escherichia coli DG 75 cells are to a large extent released as envelope-bound complexes which sediment more rapidly than envelope-bound complexes from exponentially growth cells. A minor fraction (about 3%) represents relatively slow sedimenting envelope-free nucleoids. 2. Morphological analysis of the sensitivity of amino-acid-starved cells to the action of lysozyme and/or detergents indicates that these cells are less susceptible to lysis than exponentially grown cells. This results in the production of fast sedimenting envelope-bound complexes from non-dividing cells. We infer that it is not the amount of DNA, as suggested by Ryder and Smith (1974), but the low degree of envelope fragmentation that causes the high sedimentation rate. 3. After prolonged periods of starvation about 3% of cells in the process of division persist in the population. The results indicate that these cells release their (terminated) chromosomes in the envelope-free form. At this stage it is impossible to conclude whether these chromosomes are released because of their detachment from the membrane in situ (cf. Worcel and Burgi, 1974) or because of an enhanced susceptibility of dividing cells to lysis.

Amino Acids↗
PubMed1976

Factors affecting the release of folded chromosomes from Escherichia coli.

1. The envelope-bound folded chromosome prepared by gentle lysis of Escherichia coli K 12 DG 75 cells in the presence of 1.0 M sodium chloride was found to be a non-specific complex of DNA strands entangled in vesicle-like envelope structures. This envelope remnant is still more or less rod-shaped. 2. Both the envelope-bound and the envelope-free folded chromosomes arise directly from intact cells. Even under extreme conditions of lysis, envelope-bound chromosomes cannot be converted into envelope-free nucleoids.

Cell Fractionation↗
PubMed1976

Pulmonary O2 diffusing capacity at exercise by a modified rebreathing method.

The rebreathing technique for the measurement of the pulmonary O2 diffusing capacity, DO2, previously developed for resting conditions [Cerretelli et al., J. appl. Physiol. 37, 526-532 (1974)] has been modified for application to exercise and simplified to one rebreathing maneuver only. The changes consist: 1) in administering in the course of a normoxic exercise a priming breath of an O2 free mixture just before the onset of rebreathing in order to achieve rapidly the appropriate starting PO2 values on the linear part of the O2 dissociation curve as required by the method; 2) in calculating mixed venous blood O2 tension by extrapolation of the alveolar to mixed venous blood PO2 equilibration curve, instead of determining it separately. While the mean DO2 value of 21 measurements on 5 subjects at rest was 30 ml-min-1 - Torr-1 +/- 3 (S.E.), in 2 subjects exercising on a bicycle ergometer, DO2 was found to increase from a resting value of about 32 ml- min-1 - Torr-1 to 107 ml - min-1 - Torr-1 for an eightfold increase of O2 uptake. The validity and the applicability of the method are critically discussed.

Humans↗
PubMed1976

[Acute polyradiculitis. Experiences in an intensive care unit].

30 patients with acute polyradiculitis treated in an intensive care unit between 1960 and 1974 are described. Intensive care in these patients was indicated mainly for respiratory problems necessitating tracheotomy and, frequently, artificial ventilation. The main complications encountered are described in detail: they are infections of the respiratory and urinary tracts; cardiovascular problems (mainly instability of blood pressure and sinus tachycardia, and sometimes lifethreatening arrhythmias); frequent thromboembolic complications in patients not on anticoagulants; and bleeding (especially from the gastrointestinal tract) even in the absence of anticoagulants. A careful search should be made for glomerulonephritis, "Schwartz-Bartter-syndrome" or difficulties in regulating calcium metabolism. The prognosis is independent of the time course of the disease. The mortality of 23% in this seriously ill group of patients is fairly low, but the results as far as healing is concerned are less good. In only 23% was there complete rehabilitation, whereas 34% had minor and 20% major residual symptoms.

Acute Disease↗