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Biomedical subjects

W Meier-Ruge

Publications and source records attributed to W Meier-Ruge.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Neuronal colon dysplasia in adulthood. Diagnosis, clinical aspects and therapy].

In patients with primary chronic constipation (n = 18) and diverticulosis of the sigmoid (n = 17) biopsies were examined enzyme-histochemically and the diagnosis of neuronal colonic dysplasia of the rectosigmoid was established. In eleven controls however a normal innervation was observed (p less than 0.001). Patients with neuronal colonic dysplasia usually failed to respond to conservative methods of treatment. Indication for surgery depended upon the duration and severity of the symptoms. The actual treatment--partial lateral submucous sphincterotomy, resection of the sigmoid colon or subtotal colectomy--was determined by the extent of the morphologically and functionally altered intestinal segment.

Adult↗
PubMed1991

Diagnosis of neuronal colonic dysplasia in primary chronic constipation and sigmoid diverticulosis endoscopic biopsy and enzyme-histochemical examination.

Neuronal colonic dysplasia is a separate clinical entity belonging to the group of congenital defects of intestinal innervation. Its enzyme-histochemical diagnosis is possible by endoscopic biopsy examination of the rectosigmoid. Enzyme-histochemically, it is characterized by dysplasia of the submucous plexus secondary to developmental defects. The principal clinical feature is weak propulsive motility. A clinical study was carried out to investigate the role of neuronal colonic dysplasia in the aetiology and pathogenesis of primary chronic constipation and diverticulosis of the sigmoid colon in adults.

Acetylcholinesterase↗
PubMed1991

Senile dementia: a threshold phenomenon of normal aging? A contribution to the functional reserve hypothesis of the brain.

Neurochemical investigations with normal aging brains show that in the first 70 years of life no major changes of the glycolytic pathway can be observed. Only in the following decades does a significant decrease of brain metabolic turnover occur. Changes in nerve cell size, one of the most relevant parameters in evaluating a diffuse nerve cell atrophy, appear in the brain cortex not earlier than between 85 and 94 years of age; a 21% nerve cell shrinkage is the mean. The results demonstrate that a significant decrease in turnover of the glycolytic pathway is followed by a significant but moderate shrinkage of the nerve cells after a delay of 10-15 years. Similar investigations in brains from senile demented subjects demonstrate that the change in glycolytic turnover is much more a quantitative than a qualitative phenomenon. In comparison with age-matched controls a decrease in glycolytic turnover of more than 60% is observed. Morphometric investigations of the nerve cell sizes in the brain cortex of senile demented subjects showed a decrease of 45-55% when compared with age-matched controls. When normal aging is compared with senile dementia it seems that old age dementia is a threshold phenomenon which starts if the glycolytic turnover drops below 50% of its value in young healthy adults. Physiological aging, however, stays within the range of the reserve capacity of normal brain performance. In conclusion, it seems that the exhaustion of the functional reserve capacity may shift an aging brain into a dementia syndrome.

Adult↗
PubMed1991

[Classification of malformations of colorectal innervation].

Inborn errors of colorectal innervation can be classified in four different forms: 1. Aganglionosis (including total aganglionosis of the colon, Hirschsprung's disease, ultrashort Hirschsprung's segment and neurogenic sphincter achalasia) 2. Hypoganglionosis 3. Congenital malformation of sympathetic innervation of the colon (Neuronal Intestinal Dysplasia Typ A or NID A) 4. Congenital malformation of the submucous plexus (Neuronal Intestional Dysplasia Typ B or NID B). We find in 52.2% of our biopsies with a characteristic malformation of the colorectal innervation an aganglionosis. 40.6% are malformations of the submucous plexus (NID B). Half of the cases with Hirschsprung's disease are combined with NID B. 5.0% of the classified colorectal malformations of the innervation are a hypoganglionosis and 2.2% a NID A. An additional half of our biopsies cannot be introduced into the above given classification due to moderate malformations of the colorectal innervation (mild dysganglionosis, hypogenetic nerve cells of the submucous plexus, heterotopic nerve cells of the submucous and myenteric plexus).

Colon↗
PubMed1990

Morphological adaptive response of the synaptic junctional zones in the human dentate gyrus during aging and Alzheimer's disease.

A computer-assisted morphometric study has been carried out on ethanol phosphotungstic acid (E-PTA) stained synaptic junctions in the human dentate gyrus supragranular layer from adult, old and Alzheimer's disease (AD)-affected patients. The number of synapses per unit volume of tissue (Nv = numerical density), the average area of the single junction (S) and the total area of the synaptic contact zones in a unit volume of tissue (Sv = surface density) were the 3 parameters taken into account. The synapse to neurone ratio was also calculated for each patient. During physiological aging, Nv and Sv significantly decreased and S increased, respectively. In the AD hippocampi, Nv and Sv underwent a further decrease which was in the range of more than 40% with reference to the adult values. S was the same as the old control group. In comparison with the adult values, the number of synapse/neurone decreased by 15.6 and 48% in old and AD patients, respectively. Nv, S and Sv, while reporting on discrete ultrastructural features of the synaptic junctional zones, are closely related to each other and, taken together per group of patients, may represent a reliable index of the morphological adaptive changes taking place at the synapses. Thus, the significant increase of S both in old and AD hippocampi may be regarded as a CNS plastic response to aging and disease, although the marked decrease of Nv and Sv supports that in AD synaptic ultrastructural alterations proceed beyond a critical threshold for functional recovery.

Aged↗
PubMed1990

Senile plaques: staining for acetylcholinesterase and A4 protein: a comparative study in the hippocampus and entorhinal cortex.

In 20 unselected autopsy cases tissue blocks from the hippocampus with adjacent entorhinal cortex and neocortex were stained for acetylcholinesterase (AChE). From five brains shown to have large numbers of senile plaques tissue, adjacent to that taken for AChE tissue blocks, was embedded in paraffin and sections were immunostained for the A4 protein. The morphological aspects were compared. Equivalent types of plaques and plaque-like structures were observed in the A4- and ACHE-stained sections. On selected tissue blocks from patients with many senile plaques two immediately adjacent cryostat sections were stained, one for AChE and one for A4 protein. The same individual plaques could be identified on the two sections. These findings suggest that high AChE activity is intimately associated with the process of A4 protein formation and accumulation in plaques and that this association already occurs at a very early stage of plaque formation.

Acetylcholinesterase↗
PubMed1990

The paradox of increased microvascular visualization with decreased perfusion in cerebral focal ischaemia in a primate model.

Microvasculature of the right caudate nucleus and insular cortex of monkeys with their right middle cerebral artery occluded was morphometrically measured with an image analysis system at 1/2, 4, 12, 24, and 48 hr and 2 weeks. A biphasic change in the microvasculature was observed. In the first phase up to 12 hr an increase in the number and length of the total microvasculature, visualized by alkaline phosphatase staining, along with a reduction in the number and length of the perfused part of the microvasculature, visualized by India ink perfusion, was observed. In the second phase after 48 hr, the number and length of the total microvascular bed as well as the perfused functional bed were significantly reduced.

Animals↗
PubMed1989

Effects of brovincamine on stereological capillary parameters in adult and old Fischer-344 rats.

The intercapillary distance in the parietal cortex (area 39) and hippocampus (CA1 region) was greater in senescent Fischer-344 rats (27 1/2 months old) than in adult Fischer-344 rats (18 months old). Furthermore, an improvement was found in stereological parameter after a 42-day period of treatment with brovincamine (Sabromin) at dosages of 2.5, 5.0, and 10.0 mg/kg. Treated senescent rats showed a dose-dependent decrease in intercapillary distance and an increase in the number of capillary segments per measurement field compared with untreated controls. The values approximated those found in the adult control animals. In the adult rats the administration of the drug induced similar but far less marked changes in the stereology of the capillary network. The findings suggest that brovincamine affects the interactions between nerve cells, astroglia, and capillary blood flow (changes of the intercapillary microenvironment). The results show that a 42-day treatment with brovincamine decreases pericapillary resistance, thus supporting capillary microcirculation.

Aging↗
PubMed1989

Computer-assisted morphometry of synaptic plasticity during aging and dementia.

A computer assisted morphometric study has been carried out on synaptic membranes in the dentate gyrus supragranular layer and cerebellar glomerulus from adult, old and demented patients. Numerical (Nv) and surface (Sv) densities as well as average area (S) of the synaptic contact zones were calculated directly on electron microscopic negatives by means of an ASBA (Wild Leitz, AG) image analyzer properly programmed. The results showed a decrease of Nv in both the CNS areas investigated during aging and, to a higher extent, in senile dementia. S was found to be significantly increased in old and demented CNS as compared with adult values. In the old hippocampus Sv was decreased by 40% whereas no significant difference was present between old and adult cerebellum; in senile dementia this parameter underwent a significant decrease in both areas investigated. We interpret the present findings in terms of morphological remodelling capability of the synaptic junctional zones during aging and disease.

Aged↗
PubMed1989

[Megacystis microcolon intestinal hypoperistalsis syndrome: A neuropathy?].

2 cases of megacystis microcolon intestinal hypoperistalsis are presented. A female newborn was capable of being fed completely enterally after three months. Laparotomy was not performed. A male newborn was subjected to laparotomy after 3 days and an ileal stoma was applied. The infant died after 6 months of complete parenteral feeding without any peristalsis having been initiated. Biopsies of the colon and small intestine of the patient showed normal HE staining findings. Histochemical examination revealed type B neuronal dysplasia with neuronal hypogenesis. The findings of 27 cases described in the literature are discussed with special reference to the histological findings of the intestinal wall.

Chronic Disease↗
PubMed1989

Fibronectin content of the annulus fibrosus in diabetic and non-diabetic sand rats.

Annulus fibrosus of intervertebral discs from diabetic and non-diabetic sand rats were examined by microspectrophotometry for fibronectin content. This was higher in the diabetic animals both in the dorsal and ventral parts and in the outer and inner lamellae of the annulus. It is suggested that diabetes-related changes in fibronectin are similar to changes in annular collagen observed in species other than sand rats.

Animals↗
PubMed1989

Age-related changes in fibronectin in annulus fibrosus of the sand rat (Psammomys obesus).

Fibronectin stains were carried out and evaluated by microspectrophotometric techniques in annuli fibrosi of vertebral discs of sand rats (Psammomys obesus) of both sexes and two age groups, 13-18 months and over 2 years of age. The distribution of fibronectin in the annulus shows a centripetal gradient from the outer to the inner laminae. Fibronectin was significantly more abundant in the annuli of old than of young animals of corresponding sex. Sex differences were not significant. The dorsal segment contained more fibronectin than the ventral, but the difference was statistically significant only in the aged females. The outer laminae of the annuli appeared consistently higher in fibronectin content than the inner laminae.

Aging↗
PubMed1989

Quantitative morphology of the zinc-iodide-osmium (ZIO) stained synaptic vesicles.

A computer assisted morphometric method has been elaborated to quantify synaptic vesicles evidenced by means of the Zinc-Iodide-Osmium (ZIO) staining procedure in nerve endings of a very discrete area of the cerebellar granular layer: the glomerulus. The following parameters were calculated directly on electron microscopic negatives of 4.67 microns 2 of surface terminal area: number of vesicles per unit area (Na), and per unit volume (Nv), volume density (Vv), average diameter (d) and average volume of the single vesicle (V). Ultrastructural changes taking place at nerve endings also cover synaptic vesicles, thus quantitative studies regarding vesicle population at synaptic regions can be correlated to functional changes occurring in the process of chemical transmission and reflect the plasticity of synaptic junctional zones. Although this histochemical staining method generally is referred to as unspecific, after comparing our data with the available literature reports, we propose that ZIO-positive vesicles could have a physiological significance. These ZIO-positive organelles could take part in the intraterminal homeostatic control of Ca++ ions.

Animals↗
PubMed1988

Aquagenic pruritus. Water-induced activation of acetylcholinesterase.

Four patients with aquagenic pruritus (AP), one patient with polycythemia rubra vera, one patient with cold urticaria, and three normal control volunteers were studied to better understand the pathophysiology of water-induced itching. Punch biopsy specimens were taken before and after water contact; the specimens were immediately frozen, sectioned, and stained histochemically for acetylcholinesterase (AChE) activity. This was localized in the nerve fibers surrounding eccrine sweat glands and was quantified by microspectrophotometry. In AP and polycythemia rubra vera after water exposure a significantly increased AChE activity suggesting acetylcholine release was observed, whereas in the patient with cold urticaria and the controls, a significant decrease was noted. Two related patients with AP had an inherited abnormality of serum cholinesterase, which, however, had no obvious correlation with their particular disease. The proof of AChE activation might support the clinical diagnosis and indicate a hypothetical involvement of eccrine sweat glands in the pathogenesis of AP.

Acetylcholinesterase↗