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Biomedical subjects

M Bergmann

Publications and source records attributed to M Bergmann.

At least 199 records · Page 11Linked to original sources
PubMed1990

Distribution pattern of testicular sulphydryloxidase immuno-activity in the djungarian hamster (Phodopus sungorus) during photoperiodically induced involution and recrudescence.

The distribution pattern of testicular sulphydryloxidase (SOx) immuno-activity was investigated in the djungarian hamster during photoperiodically induced testicular involution and recrudescence. SOx immuno-activity, indicating functional integrity of labelled cells, did not change in pachytene spermatocytes and spermatids as long as these cells were present in the seminiferous epithelium. Its disappearance coincided with the degeneration of spermatocytes in phases IV and V of involution and reappeared during recrudescence, when the first spermatogenic wave had reached the pachytene stage. In tubules at phase VI of involution (showing maximal regression), the apical cytoplasm of Sertoli cells showed immuno-activity. This immuno-activity disappeared during recrudescence prior to the differentiation of pachytene spermatocytes. Changes in SOx immuno-activity resembled those of lactate dehydrogenase-X (LDH-X) in photo-inhibited testes or during puberty, indicating a close functional relationship which still remains to be elucidated. The data suggest that the hamster exposed to different photoperiods can be used as a suitable model to study the relationship between testicular morphology and function in different states of gonadal activity.

Animals↗
PubMed1990

Long-term echocardiographic examinations in chronic hemodialysis patients substituted with recombinant human erythropoietin.

Cardiomegaly and impaired cardiac function induced by renal anemia are frequent findings in patients with chronic renal failure. The present investigation was performed to study the cardiac effects of a therapy with recombinant human erythropoietin in patients on maintenance hemodialysis. Echocardiographic examinations showed a decrease in cardiac size and left-ventricular mass continuously over 12 months of effective erythropoietin substitution. Cardiac output was reduced, and ejection fraction and myocardial contractility increased. The development of aggravation of arterial hypertension did not counteract the beneficial effects of erythropoietin on cardiac performance.

Cardiomegaly↗
PubMed1990

[Striato-nigral degeneration (SND): a multisystem atrophy?].

Two cases of striato-nigral degeneration are reported. In case 1 the female patient showed a Parkinson syndrome, cardiac arrhythmias and vasomotor disturbances. Morphologically mainly the putamen and substantia nigra revealed severe atrophic changes according to the restricted form of striato-nigral degeneration (SND). In case 2 there was a disorder of the upper and lower motor neuron in a female patient. Morphologically this case was an example of a multisystem atrophy with changes in the striato-nigral, olivo-ponto-cerebellar systems and spinal motor and autonomic neurons. These cases demonstrate the variability of the striato-nigral degenerations which are met with in two forms: a "pure" form as in case one and as a part of multisystem atrophies. This is underlined in a review of 69 literature cases, which also shows that SND, Shy-Drager syndrome and olivo-ponto-cerebellar atrophy represent very probably different varieties of one and the same degenerative process.

Aged↗
PubMed1990

[Centroblast morphology: a morphometric evaluation by means of computer-aided image analysis].

In cytologic preparations, cell images from 30 cases of high grade malignant Non-Hodgkin's lymphoma (NHL) and 10 cases of tonsillitis have been analysed using a colour TV microscope system, high resolution scanning and image processing. Multivariate analysis of 30 cell features allowed satisfying recognition and discrimination of centrocytes, centrocyte-like centroblasts, ordinary centroblasts and multilobated centroblasts. In addition, according to their image analytical data, the ordinary centroblasts from NHL formed 5, and those from tonsillitis 4 well defined, homogeneous clusters. Even at simultaneous analysis, there was an essential overlap only between centroblast subtype 3 from NHL and subtype 9 from tonsillitis, but reliable discrimination of all the rest.

Computers↗
PubMed1990

Neuroepithelial cell contacts in 12 days old rat embryo: normal and annulated gap junctions.

Neuroepithelial cells in the neural tube of 12 days old rat embryos make contact with each other by extended junctional complexes between their lateral membranes near the luminal surface. In this stage gap junctions are not numerous. Besides these "normal" gap junctions, especially in the upper part of the neuroepithelial cells, annulated gap junctions occur. They seem to originate by an endocytotic process of normal gap junctions with participation of cytoskeletal elements. The content of these annulated gap junctions mainly consists of ribosome-like particles in a high density, but larger particles may also occur. Annulated gap junctions sometimes reveal an intimate contact with the smooth endoplasmic reticulum or with the perinuclear cistern. If present in the perinuclear region the annulated gap junctions show membrane irregularities and other signs which are thought to mark steps of breakdown. Life-cycle and possible functions of the annulated gap junctions during neurulation need further investigation.

Animals↗
PubMed1990

Automated recognition of cell images in high grade malignant lymphoma and reactive follicular hyperplasia.

In the past, the comparison of results of studies on malignant lymphomas has been biased by the use of different classifications of the diseases and to an even greater extent by subjective interpretation in the classification of the tumour cells. To overcome these short-comings, we have developed cytometric features specifically for automated recognition of cell images from high grade malignant non-Hodgkin's lymphomas (NHL) and reactive lymphoid lesions. This study used a colour TV-microscope system, high resolution scanning (13.3 pixel/microns), and image processing to study a total of 3600 lymphoid cells from 15 high grade malignant NHL and three tonsils. Sixteen out of 64 features, especially developed for image analysis in cytological preparations, have been evaluated. Because of a considerable overlap of all the single features, no feature on its own allows reliable discrimination. But, multivariant analysis of suitable feature combinations resulted in reliable identification and discrimination of the most frequently occurring cell types. We show that the lymphocytes, centrocytes, centroblasts, immunoblasts and lymphoblasts, as they are defined by subjective morphological criteria in the Kiel-classification of malignant NHL, also form distinctive subpopulations on the basis of their objective mathematical cell features. Furthermore, we have shown that there are distinctive differences between the lymphoma cells and their benign counterparts derived from reactive lymphoid lesions.

Diagnosis, Differential↗
PubMed1990

[Use of a capacitive measuring mat for recording inter-fragment pressures and pressure distribution in ventral inter-corporal spondylodesis].

With respect to ventral interbody fusion, rates of pseudarthrosis of up to 30% are reported. With the aim of reducing this figure, the use of dorsal fixation systems to stabilise the fused spinal units is recommended by a number of authors. The aim of these osteosynthetic procedures is to elevate the interfragmentary compression between the ventral bone block and the adjacent vertebrae. In order to measure the pressure achievable, and its local distribution, an experimental investigation involving the use of a capacitive measuring mat has been designed. The system of capacitive measurement and its application to the spine is described. The simple mode of measurement and mechanical stability, combined with high accuracy, are the specific advantages of capacitive systems of measurement. Especially in the documentation of interfragmentary pressure and pressure distribution, capacitive measuring mats are superior to comparable systems.

Biomechanical Phenomena↗
PubMed1990

[Long-term results and histologic studies following surgical correction of congenital penis deviation].

Between 1982 and 1988, 11 patients with congenital penile curvature without hypospadia or chordee were operated according to the technique originally described by Nesbit. In all these patients the operative results were reevaluated after a period of 1 1/2 to 7 years (average 3 3/4 years). Normal sexual intercourse was possible for all 11 men, and good long-term cosmetic results were noted. In contrast to formerly published results, histological examination of the segments resected from the tunica albuginea showed fibrotic tissue in some cases, which could play an important role in the etiology and/or pathogenesis of congenital penile curvature.

Adolescent↗
PubMed1990

Iron metabolism under rEPO therapy in patients on maintenance hemodialysis.

Therapy with recombinant human erythropoietin (rEPO) can correct anemia in RDT patients. However, iron deficiency can develop making treatment unsuccessful. Eighteen non-transfused RDT patients with hematocrit less than 26% were treated with rEPO to raise the HCT to 30-35%; then the dose was individually adjusted to maintain the HCT. The mean HCT rose from 22.3% to 31.5%. Ten patients received iron substitution before rEPO. During rEPO therapy five further patients had to be supplemented with iron; all patients needed an increase in the oral iron doses and three required i.v. iron. During the correction phase mean serum ferritin dropped from 203 micrograms/l to a minimum of 71 micrograms/l and was 102 micrograms/l after six months. Serum iron and TIBC changed only moderately. It thus appears that iron demand rises markedly during rEPO therapy, requiring iron substitution in most patients. Serum ferritin is the most sensitive parameter for development of iron deficiency.

Anemia↗
PubMed1989

[Synopsis of the results of some studies of the pathogenesis and clinical aspects of chronic gastritis in relation to stomach ulcer].

A review is given of our own results concerning gastric mucosa biopsy and gastritis classification. Moreover, results regarding the gastritis-induced influence upon the gastric mucosa barrier in the form of histotopochemical investigations of gastric mucus substances are briefly presented. By means of measurements of gastric motility (own method of evaluation), the results of the influence upon gastric motility in atrophic antrum gastritis are discussed.

Biopsy↗
PubMed1989

Pattern of compartmentation in human seminiferous tubules showing dislocation of spermatogonia.

The pattern of compartmentation of the seminiferous epithelium was investigated, using a lanthanum tracer technique, in human testicular biopsies of adult infertile men (age 27 to 44 years), where dislocation of spermatogonia from the basal lamina occurred. Spermatogonia type A and B were found in a two- or three-layered arrangement, in aberrant locations throughout the seminiferous epithelium, and in intratubular positions associated with fragments of Sertoli cell cytoplasm. Tracer impregnation was found around spermatogonia in a multilayered arrangement, indicating the extension of the basal compartment in a luminal direction. Single spermatogonia within the second or third layer of the seminiferous epithelium were regularly found to be surrounded by tracer. The junctional complex between the lateral membranes of adjacent Sertoli cells was devoid of tight junctions. Tracer penetration around spermatogonia in a more luminal position was prevented by intact Sertoli cell junctional complexes; tracer was also absent from intraluminal located spermatogonia associated with cytoplasmic fragments of Sertoli cells. The luminal extension of the basal compartment associated with the dislocation of spermatogonia clearly differs from the pattern of compartmentation during the movement of primary spermatocytes within undisturbed epithelium. There is a strong incidence of elevated serum levels of follicle-stimulating hormone (greater than 7 U/l), indicating a suppression of Sertoli cell function; this may be the cause for the dislocation of spermatogonia and the changes of compartmentation.

Adult↗
PubMed1989

Ultrastructural localization of thyrotropin (TSH)-like immunoreactivity in specific secretory cells of the hypophyseal pars tuberalis in the Djungarian hamster, Phodopus sungorus.

Specific secretory cells in the hypophyseal pars tuberalis of Djungarian hamsters maintained under different photoperiods were investigated immunocytochemically by means of the colloidal gold technique using antibodies against rat thyrotropin (TSH). Secretory cells of animals kept under long photoperiods (LD16:8) showed positive staining of secretory granules (diameters 90-130 nm), whereas other intracellular structures were free of immunoreactivity. In animals kept under short photoperiods (LD8:16) secretory cells displayed increased numbers of secretory granules, but these organelles were devoid of immunoreactivity. In contrast, immunoreactivity of thyrotropes in the pars distalis did not differ between the two groups of animals investigated. The present results confirm earlier light-microscopical studies that in the pars tuberalis specific secretory, cells show TSH-like immunoreactivity; however, they differ in their reactivity pattern from classical thyrotropes in the pars distalis.

Animals↗
PubMed1989

The cruciate ligaments in knee replacement.

The cruciate ligaments were resected with their bony insertions during total knee arthroplasty carried out in 12 patients with severe rheumatoid or osteoarthritis. The ligaments were examined histologically and biomechanically, using ten specimens from healthy adults as a control. A significant difference was found in the tensile stiffness and viscoelastic properties of the ligaments between the arthritic and the control group. The ligaments in the rheumatoid knees had a distinctly inferior tensile strength compared with the osteoarthritic knees. Total knee replacement, which also replaces ligament function, should therefore be considered in severely damaged rheumatoid knees.

Arthritis, Rheumatoid↗
PubMed1989

Computer aided cytometry in high grade malignant non-Hodgkin's lymphomas and tonsils.

The aim of the study is to establish quantitative cytological criteria for reliable diagnoses in high grade malignant non-Hodgkin's lymphomas (NHL). For this purpose Pappenheim-stained cytologic imprints from 15 cases of high grade malignant NHL and ten cases of chronic tonsillitis have been analysed using a TV-microscope system, high resolution color scanning (13.3 pixel/microns), and image processing on a computer. The highly reliable computer-extracted cell features can be used to discriminate the different cell types of malignant NHL. Because of a considerable overlap, no feature on its own is sufficient to discriminate all the different cells. Only multivariate analysis of a suitable combination of features allows reliable discrimination. The results show that the different cells defined by subjective morphological criteria in the Kiel-classification of malignant NHL also form distinctive subpopulations with regard to their objective mathematical cell features and show distinctive differences when compared with their benign counterparts derived from reactive lymphatic tissue.

Color↗
PubMed1989

Differential effects of follicle-stimulating hormone and luteinizing hormone on Leydig cell function and restoration of spermatogenesis in hypophysectomized and photoinhibited Djungarian hamsters (Phodopus sungorus).

Effects of pure human follicle-stimulating hormone (hFSH) and ovine luteinizing hormone (oLH) on testicular function were investigated in long-term hypophysectomized or photoinhibited Djungarian hamsters. hFSH (5 IU) or oLH (5 micrograms) or a combination of FSH and LH (5 IU and 5 micrograms, respectively) were injected s.c. twice daily for 7 days to hypophysectomized and photoinhibited hamsters. Other photoinhibited hamsters were treated for 14 and 21 days with FSH and LH (3 IU and 3 micrograms, respectively) in a similar way. LH alone had little, if any, effect on testicular weights; FSH, when injected alone or in combination with LH (FSH/LH), caused a significant increase in testes weights at each time point. On the other hand, LH or FSH/LH, but not FSH alone, caused a significant increase in the accessory organ weights. FSH had no effect on intratesticular testosterone (T) or on 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity but enhanced the in vitro response of interstitial cells to hCG. LH and FSH/LH had pronounced effects on intratesticular T, 3 beta-HSD activity, and in vitro response of interstitial cells to human chorionic gonadotropin. Treatment with FSH or FSH/LH caused regrowth of the testis and restoration of tubular lumen and tubular diameter and restored complete spermatogenesis. However, LH had little effect on spermatogenesis in spite of increased intratesticular and peripheral T levels. These results indicate that although LH can cause a full redifferentiation of Leydig cells in photoinhibited hamsters, it has only minor effects on tubular function. On the other hand, FSH alone induces full restoration of tubular function in these animals and has no direct effect on Leydig cell steroidogenesis, but may enhance the Leydig cell responsiveness to LH.

3-Hydroxysteroid Dehydrogenases↗
PubMed1989

Pulsatile GnRH-therapy in oligozoospermic men does not improve seminal parameters despite decreased FSH levels.

In order to evaluate GnRH administration for the treatment of infertile men with elevated serum FSH levels we administered GnRH in pulses via portable electronic infusion pumps initially to seven patients with low sperm counts and high FSH values over 12 weeks and later to nine further patients over 24 weeks who also underwent testicular biopsies. Fifty microlitres containing 5 micrograms GnRH were infused subcutaneously for 1 min every 120 min in the short-term study and every 90 min in the long-term study. Although FSH levels could be lowered in both groups of patients, none showed any improvement in sperm count or other seminal parameters. Therefore, pulsatile GnRH treatment cannot be recommended for therapy of severe oligozoospermia with elevated FSH levels.

Adult↗
PubMed1989

True hermaphroditism with bilateral ovotestis: a case report.

A true hermaphrodite with a 46 XX/47 XXY karyotype, gynaecomastia, hypospadia and scrotal gonads was investigated. Gonadectomy performed at 14 years of age revealed bilateral ovotestes. The ovarian portion contained follicles of all developmental stages. The testicular portion was immature consisting of seminiferous cords with Sertoli cells at various steps of differentiation and few germ cells within massive aggregates of collagenous connective tissue. Leydig cells as well as germ cells remained in an embryonic stage of development. Sections of a differentiated Wolffian duct (ductuli efferentes, epididymis, vas deferens) as well as of a Müllerian duct (hypoplastic fallopian tube) were found adjacent to both gonads. Postoperative treatment consisted of androgen substitution therapy leading to progression of puberty.

Adolescent↗