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Biomedical subjects

M Bergmann

Publications and source records attributed to M Bergmann.

At least 217 records · Page 12Linked to original sources
PubMed1989

Fluid-phase transcytosis in the primate epididymis in vitro and in vivo.

Ligated tubules from the corpus epididymidis of men and monkeys were incubated in medium containing horseradish peroxidase (HRP) as a marker for fluid-phase endocytosis. HRP was localized by light and electron microscopy after 0, 15, 30 and 60 min of incubation. Movement between the cells was prevented by tight junctions, but bypass of this barrier was apparently achieved by an intracellular vesicular mechanism leading to a time-dependent appearance of HRP in the lumen. Uptake of HRP into basal cells and capture by the lysosomal apparatus of principal cells were also observed. HRP-filled vesicles also appeared in the basal, mid and apical cytoplasm of epithelial cells in the caput 1 h after injection of the tracer into the epididymal circulation of the monkey, suggesting that this pathway also operates in vivo.

Aged↗
PubMed1989

Freeze-etching study of intercellular junctions in the rat developing neural tube.

The intramembranous organization of the neuroepithelial intercellular junctions in the rat neural tube on days E13 and E15 was studied by using the freeze-etching technique. Tight junctions, frequently altered, are distinguished as the predominant type of intercellular junctions. Relatively rare gap junctions like intramembranous particle aggregations of varying sizes and particle packing occur too. The possible formation or breakdown of these probably temporary cell junction specializations is discussed.

Animals↗
PubMed1989

Echocardiographic findings in patients on maintenance hemodialysis substituted with recombinant human erythropoietin.

Cardiomegaly and impaired myocardial function are frequent in patients on maintenance hemodialysis. One important reason is probably severe renal anemia. Substitution with recombinant human erythropoietin (rhEPO) results in long-term correction of renal anemia. We investigated the changes in cardiac function under rhEPO therapy using echocardiography. 13 patients with severe renal anemia (hct less than 26%) but independent of regular blood transfusions during the last six months were treated with 40-120 IU/kg rhEPO intravenously three times/week. Echocardiographic studies were performed in the anemic state and when hematocrit values were stable at levels above 30%. Left ventricular end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD) were reduced (LVEDD: 53.9 +/- 4.2 mm vs. 51.4 +/- 5.8 mm; LVESD: 35.7 +/- 5 mm vs. 32.8 +/- 5 mm). Mean end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were also diminished (LVEDV: 141.9 +/- 25.4 ml vs. 128.1 +/- 32.5 ml; LVESV: 54.8 +/- 18.6 ml vs. 45.1 +/- 17 ml). Stroke volume (SV) fell slightly from 87.1 ml to 83 ml resulting in a decrease of cardiac output (CO) from 6.9 +/- 1.6 l/min to 6.2 +/- 1.7 l/min. The thickness of the left ventricular posterior wall (LVPW) and of the septum interventriculare (IVS) remained constant. Myocardial contractility indicated by ejection fraction (EF), fractional shortening (FS) and the velocity of circumferential fiber shortening (VCF) frequently improved. Our data indicate that correction of renal anemia by rhEPO can improve myocardial function in patients on maintenance hemodialysis.

Anemia↗
PubMed1989

The vegetative network in the thoracolumbar spinal cord of the guinea pig: a comparison of the distribution of AChE-enzyme activity and choline acetyltransferase-like immunoreactivity.

Histochemically the acetylcholinesterase (AChE) enzyme activity and immunocytochemically the choline acetyltransferase-like immunoreactivity (ChAT-LI) were located in the components of the vegetative network of the thoracolumbar spinal cord of the guinea pig. Both reaction products showed an identical distribution among the preganglionic sympathetic cells and the processes of the vegetative network, namely: cells of the nucleus intermediolateralis pars principalis (ILp), the nucleus intermediolateralis pars funicularis (ILf), the nucleus intercalatus spinalis (IC) and the nucleus intercalatus paraependymalis (ICpe; terminology according to Petras and Cummings 1972). In longitudinal horizontal sections through the intermediate zone of the thoracolumbar spinal cord both AChE-positive- and ChAT-like immunoreactive nerve fibers were organized into two longitudinal lateral fascicles (FLL), two longitudinal medial fascicles (FLM) as well as oblique and transverse bundles that interconnect repeatedly the autonomic cell groups of this zone along the spinal cord and contribute to the ladder-like shape of the vegetative network. The ChAT-like immunostaining of the vegetative network showed that the dendrites of the ILp cells are oriented mainly in a rostrocaudal, but also in a mediolateral direction. Similar orientation of the dendrites was observed for the ICpe cell groups of the thoracolumbar intermediate zone. Thus it is evident that ILp cell bodies and dendrites are involved in the formation of the FLL, whereas the ICpe cells and their dendrites--of the FLM. The IC cells send their dendrites towards both the ILp and ICpe cells and build up together with dendrites of the ILp and ICpe cells the transverse and oblique interconnecting bundles. The vegetative network is strongly developed within the intermediate zone of T1-T4 (mostly T3) and T7-T8 segments of the spinal cord. In these segments a greater variety of interconnections between the preganglionic sympathetic cell groups which are constituents of the network are also revealed. In the remaining segments the vegetative network is more poor developed. In the first two lumbar segments the distance between the interconnecting bundles in the rostrocaudal direction diminishes to 100 microns in contrast to 300-500 microns within the upper segments. The results obtained reveal that the cholinergic preganglionic sympathetic nuclei of the intermediate zone of the thoracolumbar spinal cord together with their dendrites represent the basis (frame) of the ladder-like vegetative network to which join in addition different peptidergic fibers of supraspinal, peripheral and propriospinal origin.

Acetylcholinesterase↗
PubMed1989

[The temporomandibular joint--structure and function during the course of development].

The temporomandibular joint is one of the most complicated articulations of our body. Its relative stability of function is in contrast to the apparent instability of some structures enclosed. The paper summarizes some thoughts about this joint and it should be stressed the especial difficulty in teaching the joint in the stomatological anatomy.

Humans↗
PubMed1989

In vivo effects of recombinant human erythropoietin on circulating human hemopoietic progenitor cells.

Recombinant human erythropoietin (rhEpo), now available, has become increasingly more important for clinical use, e.g., in the treatment of anemia of chronic renal failure, and has been shown to reverse anemia in these patients. When patients with anemia of chronic renal failure were treated with rhEpo at dosages between 40 and 120 U/kg three times per week, the numbers of circulating erythroid burst-forming units (BFU-E) and granulocyte-erythrocyte-macrophage-megakaryocyte colony-forming units (CFU-GEMM) significantly increased during the first week of therapy. In contrast, the incidence of circulating granulocyte-monocyte CFU (CFU-GM) was not significantly altered.

Cell Separation↗
PubMed1988

Photoperiod-dependent changes in TSH-like immunoreactivity of cells in the hypophysial pars tuberalis of the Djungarian hamster, Phodopus sungorus.

Certain secretory cells in the hypophysial pars tuberalis of the Djungarian hamster display marked circannual structural alterations. The present investigation deals with the immunohistochemical properties of this cell group. A distinct TSH-like immunoreactivity was found in secretory cells of this type in the pars tuberalis of animals exposed to long photoperiods, whereas under short photoperiods the TSH-like immunoreactivity was nearly absent. In the pars distalis, the number and distribution of TSH-positive cells did not differ significantly between animals maintained under long and under short photoperiods. LH- and FSH-positive cells could not be detected in the pars tuberalis, but they are clearly present in the pars distalis of both groups of hamsters. Our immunocytochemical results suggest that photoperiodic stimuli influence the secretory activity of TSH-like immunoreactive cells in the pars tuberalis. A connection with the neuroendrocrine-thyroid axis is discussed.

Animals↗
PubMed1988

Transcytosis in the epididymis studied by local arterial perfusion.

The transport of protein across the cells of the epididymal epithelium was studied using horseradish peroxidase. Transient vascular perfusion of the epididymis of the rat and golden hamster was achieved by pulsatile retrograde infusion into the testicular artery. Peroxidase was found in the interstitium and in the epithelium, located in vesicles, vacuoles and multivesicular bodies of principal, clear and apical cells. Similar findings were obtained in mice after systemic injection of the tracer. In the rat, discharge to the lumen was confirmed by the appearance of enzyme activity in luminal fluid from the caput epididymidis after local injection. The extent of transport amounted to no more than what has been considered leakage in physiological experiments, and the time-course of appearance complemented that found by electron microscopy. The level of transcytosis after pulsatile administration of peroxidase in vivo, as judged from the occurrence of tracer in the epithelium, was much less than that obtained during constant immersion in vitro. The protein was present in multivesicular bodies of principal cells and in vesicles of clear cells at short times after presentation in vitro, when it could not have arrived by endocytosis from the lumen. This suggests that routing of basal endocytic vesicles to the lysosomal apparatus occurs.

Animals↗
PubMed1988

Use of fosfomycin disks for isolation of diphtheroids.

A fosfomycin disk (200 micrograms) placed on blood agar was used to select diphtheroids from clinical specimens. All Corynebacterium type strains tested, representing ten different groups of diphtheroids, and 150 toxigenic strains of Corynebacterium diphtheriae from different outbreaks, overgrew the fosfomycin disk, while other aerobic gram-positive rods had a large inhibition zone. The method increased the rate of isolation of diphtheroids in 1267 clinical specimens fivefold, from 1.4% to 7.6%, especially when the diphtheroids were found concomitantly with other bacteria. Overgrowth of the disk by other microorganisms occurred in 11% of the samples tested, but such microorganisms could easily be distinguished by culture morphology or Gram stain. Fosfomycin disks provide a simple, highly sensitive but not very specific aid for isolation of Corynebacterium diphtheriae and diphtheroids from clinical specimens.

Corynebacterium↗
PubMed1988

[Metamizol-caffeine elimination in females with increased serum aminotransferase activities treated with steroidal oral contraceptives].

The elimination of caffeine from the plasma and the excretion of the major metabolites of metamizol (AnalginR) in the urine was studied in 25 women on long-term oral steroid contraceptives. Both tests allowed to draw conclusions about metabolic liver function. A steroid-induced delay of the elimination of caffeine in clinically healthy women with/without serologic elevation of aminotransferase activities was demonstrated. --We regard this as the consequence of an inhibition of the cytochrome P-450-dependent poly-functional oxidases of the P-450MC type, which was produced by oral contraceptives. The differences in the elimination of metamizol were not significant.

Adult↗
PubMed1988

[Comparative follow-up study in vagotomized and conservatively treated duodenal ulcer patients].

We observed 87 patients with duodenal ulcer disease about one year. 46 patients (first group) after proximal gastric vagotomy were observed. A second group (41 patients) were treated with antacids only. We compared our patients for their complaints, consumption of antacids, relapse rate and clinical, social and genetic aspects. The clearly better results of the surgically treated patients allow the conclusion for a better quality of life in patients after proximal gastric vagotomy.

Adult↗