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Biomedical subjects

W Meier-Ruge

Publications and source records attributed to W Meier-Ruge.

At least 19 recordsLinked to original sources
PubMed2003

Results of total and subtotal colon resections in children.

AIM: The treatment of long-segment neuronal intestinal malformations confronts the paediatric surgeon with the problems of diagnosis, suitable surgical methods and postoperative care. The evidence based only on ganglion cells is inadequate to decide about the required extent of resection and does not exclude hypoganglionosis and disseminated dysganglionosis. For the surgical treatment, pouch procedures as well as the usual resection techniques according to Rehbein, Soave, and Duhamel are discussed. Since studies with greater numbers of patients are rare, we present here our own results. METHODS: 48 patients with long segment intestinal malformations were treated in our hospital between 1990 and 2000. A total of 35 patients were examined 1.5-6 years after definitive surgical therapy. Rehbein's anterior resection was performed in all cases. RESULTS: Our findings showed that the surgical treatment with Rehbein's technique offers good results, both with respect to complications as well as to the postoperative course, although a 4 cm long aganglionic segment remains in situ. We found that results were better after ascendorectostomy (n = 22) compared to ileorectostomy (n = 11). Earlier publications of this group (13) show that the histology of the proximal resection margin is decisive for the prognosis. Hypo- and aganglionic segments should be completely resected while short IND segments of the colon or terminal ileum may remain in situ. However, the additional effect of the aganglionic segment of the distal rectum and the decreased peristaltic flow of the pre-anastomotic bowel has to be taken into account. Further investigations are required to find out whether a combination of Soave's endorectal pull-through with a remaining neuronal dysplastic segment proximal to the resection margin may give better results or if the frequency of postoperative enterocolitis and incontinence increased in cases of long segment intestinal neuronal malformations. Accurate diagnosis of myenteric plexus is decisive for an optimal treatment and therefore, considering our results, it is essential that in case of newborns getting to hospital with colon obstruction and suspicion of neuronal intestinal malformation full thickness biopsies from the distal and proximal colon may be taken simultaneously with the enterostomy. Generally ileostomy is performed in patients suspected of long-segment neuronal intestinal malformations. Mucosa suction biopsies from the distal and proximal stoma side are less informative compared to full thickness biopsies.

Child↗
PubMed2002

Four cases of desmosis coli: severe chronic constipation, massive dilatation of the colon, and hypoperistalsis due to of changes in the colonic connective-tissue net.

We present four patients 5, 10, 12, and 17 years of age, each with a long history of severe constipation and hypoperistalsis of the gut. Three had partial or total resection of the colon, all had enterostomies, and only one maintains normal bowel function after reanastomosis. We report the clinical courses, radiologic findings, and operative procedures for all four cases. Preoperative full-thickness biopsies and the resected colon specimens revealed a complete or incomplete lack of the mesh network of collagen. The connective-tissue layer between the circular and longitudinal muscles was missing. Contrary to expectations, the enteric nervous system (ENS) was normal or near-normal in the affected areas. Hypo- and dysganglionosis was found additionally in some proximal segments of colon and/or small bowel. This combination of clinical symptoms and pathological findings is called desmosis of the colon with reference to a working hypothesis in a preliminary report by Meier-Ruge in 1998. Aplastic or hypoplastic desmosis may be the reason for the disturbed gut motility. Histologic examination should thus not only exclude changes of the ENS.

Adolescent↗
PubMed2002

Disseminated intestinal hypoganglionosis treated by colectomy and tapering of the small intestine. A case report.

A girl suffering from chronic constipation and abdominal distension from her first year of life underwent internal anal sphincter myectomies at 5 and 7 years of age without resolution of her symptoms. At the age of 8, an ileostomy was performed because of excessive colonic dilation and hypomotility. Biopsies from the colon and distal ileum showed intestinal neuronal dysplasia TYPE B (INDB) with hypoganglionic areas. Colectomy and ileorectal anastomosis were done at the age of 10. Three years later, however, an ileostomy was re-established because of recurrent episodes of pseudo-obstruction. In the hope of improving intestinal motility, the dilated small intestine was tapered over its entire length of 3.6 meters. Histological findings still demonstrated oligoneuronal hypoganglionosis and INDB all along the resected strip of bowel wall. After 6 months, the stoma was closed. At the age of 15 years, tapering of the distal 80 cm of the ileum was repeated in combination with cholecystectomy for cholecystolithiasis. Intestinal transit time decreased from 55 hours before the first to 18 hours after the second tapering procedure. Now, 7 years after the last operation, the patient passes 3 - 4 soft stools daily, is physically active, on a normal diet and not on any regular medication.

Child↗
PubMed2001

Quantitative cytochemical mapping of mitochondrial enzymes in rat cerebella.

Mitochondrial metabolic competence, defined as the organelle's capacity to provide adequate amounts of ATP in due time, appears to constitute an important determinant in several biological processes and pathological conditions. Thus, the assessment of the metabolic efficiency of the mitochondrial population in a given tissue area or cellular compartment may provide clues to identifying alterations of the cellular bioenergetic machinery, which may constitute a predisposing condition leading to impaired organ and system functions. In the cerebellar cortex of adult rats, the activities of the enzymes cytochrome oxidase (COX) and succinic dehydrogenase (SDH) were, respectively, evidenced by means of the diaminobenzidine and copper ferrocyanide preferential cytochemical techniques. At the electron microscope, the activities of these two key molecules of the respiratory chain were clearly visualised as dark precipitates at the inner mitochondrial membrane sites where COX and SDH are located. By means of the disector method, unbiased mitochondrial samplings were carried out to measure: the number of mitochondria/microm(3) of tissue (numeric density: Nv); the mitochondrial volume fraction/microm(3) of tissue (volume density: Vv) and the average mitochondrial volume (V) both on COX- and SDH-positive organelles in the cerebellar glomeruli and Purkinje cells, respectively. The ratio R (total area of the precipitates due either to COX or SDH activity within the single mitochondrion/area of the same organelle) was also evaluated to get information on the enzyme activity related to mitochondrial size.The documented accumulation of mutant mitochondrial DNA particularly in postmitotic cells results in a marked heteroplasmy (mixtures of normal and mutated genomes) at mitochondrial and cellular levels, thus the cellular potential for energy production is demanded to a mosaic of organelles with different functional capabilities. Assessment of the mitochondrial mosaic outline by means of quantitative cytochemistry of key enzymes of the respiratory chain, such as COX and SDH, may allow for the morphofunctional metabolic mapping of mitochondrial efficiency in discrete cellular or tissue compartments.

Animals↗
PubMed2001

Pathophysiology of chronic constipation in anorectal malformations. Long-term results and preliminary anatomical investigations.

Posterior sagittal anorectoplasty provides an optimal access to reconstruct the muscle complex in anorectal malformations. It gives much better results than the abdominoperineal pullthrough procedures performed before 1984. However, severe chronic constipation occurs postoperatively in about 10 % of the patients, which can only be treated by washouts. Clinical investigations of 578 patients treated from 1962 to 1984 and from 1985 to 1997 are presented here and both groups are compared to each other. In addition, a new continence score with special regard to chronic constipation and overflow incontinence was used to follow up 133 patients of the second group. The score distinguishes between children above and below the age of 3 years. To study the underlying reasons of severe chronic constipation in children with anorectal malformations, macro- and microanatomical investigations on 4 normal newborns, 3 neonatal piglets with imperforate anus and 25 rectal biopsies from the caecum were performed. The following reasons have been found to be probably responsible for postoperative constipation and overflow incontinence: 1. Malformations of the smooth and striated muscle fibres or connective tissue of the caecum; 2. Malformations of the intramural nerve plexus such as aganglionosis, hypoganglionosis or IND; 3. Malformations and/or iatrogenic lesions of the extramural nerve supply which runs anterior to the rectum and in front of the fascia of Denonvilliers, which can hardly be identified in neonates with imperforate anus. Therefore iatrogenic bladder injuries may occur after PSARP after extended mobilisation of the caecum. The macro- and microanatomical situation in the piglet with imperforate anus is totally different from the human newborn.

Animals↗
PubMed2000

Clinical long-term follow-up results in intestinal neuronal dysplasia (IND).

Commonly available information on intestinal neuronal dysplasia (IND) is sparse. Especially well documented long-term courses are lacking. The aim of this study was to correlate defecation as a clinical parameter of the long-term course in malformations of the enteric nervous system with the morphological diagnosis. 57 children with intestinal neuronal dysplasia (IND) or aganglionosis with cranial intestinal dysganglionosis (agIND), diagnosed between 1983 and 1992, were analysed including histomorphological classification, collection of clinical data and evaluation of the defecation mode by questionnaire as a parameter of the long-term course. Of 29 dysganglionic (IND) patients, 9/29 cases (31 %) had been treated conservatively, 18/29 cases surgically (62.1%), in two children (6.9%) no therapy had been necessary. All 28 patients with Hirschsprung's disease and cranial IND (agIND) underwent resection. 46 of the children could be followed up 3.64 years after the end of the main therapeutic period and with a mean age of 6.7 years at the time of follow-up; 43.5% of the analysed children still showed severe constipation. 23.9% only were really cured; 15.2% had normal defecation still using conservative treatment and 17.4% had diarrhea. No significant difference was found between both groups, IND and agIND, and the results were independent of treatment modality. The results were much worse than in idiopathic constipation as reported in the literature and even worse in comparison to unselected Hirschsprung collectives. It has to be concluded that in IND with chronic constipation intensive long-term care is necessary and it is crucial that treatment algorithms should be outlined urgently together by pediatric gastroenterologists and pediatric surgeons. AgIND seems to need more extended resection following an exact histomorphological mapping by biopsies taken during enterostomy procedure.

Child↗
PubMed2000

Proximal segment histology of resected bowel in Hirschsprung's disease predicts postoperative bowel function.

The authors present an overview of 101 patients operated for Hirschsprung's disease by Rehbein procedure. Special attention is directed to the histomorphological findings in the proximal segment of the resected bowel specimens. A strong link was confirmed between these specific features and postoperative bowel function. A histologically regular proximal bowel segment generally predicted good postoperative bowel function with a constipation rate of 10.5%. In patients with intestinal neuronal dysplasia (IND) of the proximal segment the overall clinical result remained unchanged, although the constipation rate rose to 17.8%. Postoperative bowel function was seriously affected in cases characterized by proximal segment hypoganglionosis with a constipation rate of 23.1% and an additional 7.7% with encopresis. Finally, the distinct group of children with aganglionosis of the proximal segment followed a complicated postoperative course with secondary bowel resections and recurrent episodes of enterocolitis. In addition, the authors state their general observation that histological findings become less important whenever a more extensive resection than left hemicolectomy is required. Discussing the results, guidelines are given to further patient treatment once the particular proximal segment histology is diagnosed.

Adolescent↗
PubMed1999

[Intestinal neuronal dysplasia in adults as a cause of chronic constipation: morphometric characterization of colon innervation].

Intestinal neuronal dysplasia (IND) was initially described as a developmental abnormality of the submucous plexus in children. In recent years this abnormality has also been observed in adults with chronic constipation. The aim of this study was a morphometric characterization of this disease. The investigation was performed with 10 adults with IND, compared with 10 healthy control probands. The best diagnostic indicator of IND proved to be the detection of 6-10 giant ganglia with more than 7 nerve cells in 15 biopsy sections. IND is an interesting cause of chronic constipation which can be histologically verified.

Adult↗
PubMed1999

Intestinal transit time in children with intestinal neuronal malformations mimicking Hirschsprung's disease.

A total of 106 consecutive children with intestinal neuronal malformations were included in a prospective study. The intestinal transit time was assessed using a modification of Hinton's method. The results of transit time studies, the associated specific histochemical findings, therapeutic procedures, and the clinical course on follow-up assessments over a mean period of 2.4 years were analysed. The intestinal transit time was prolonged in all 53 patients with aganglionosis and in 37 (69.8%) out of 53 children with other intestinal malformations. Eight out of 16 children with IND type B had an abnormal transit time, 1 underwent anterior resection, and 2 had a temporary colostomy. In 7 out of 8 children with hypoganglionosis and 9 out of 10 children with a reduced parasympathetic tone the transit time was prolonged. A resection was performed in 7 and 2 of these children respectively. Both patients with heterotopia of the myenteric plexus had a prolonged bowel transit and parts of the large bowel had to be resected. Only 11 out of 17 children with heterotopia of the submucous plexus, dysganglionosis, or immature ganglia had a prolonged transit time, 2 underwent sphincteromyotomy. At follow-up, all patients with malformations other than aganglionosis stated that symptoms had improved and they were willing to tolerate their complaints. However, 25 reported on persistent constipation, 6 on overflow encopresis. All children who required surgery had a prolonged intestinal transit time, but also 21 (56.8%) of 37 children who were successfully treated without surgery. None of the 16 children with normal transit had to be operated. It is concluded that specific histochemical findings do not always correlate with delayed intestinal transport. The determination of the intestinal transit time represents an important tool to identify the clinical relevance of histochemical findings in the individual patient.

Child, Preschool↗
PubMed1999

Rectal biopsy for diagnosis of intestinal neuronal dysplasia in children: a prospective multicentre study on interobserver variation and clinical outcome.

BACKGROUND: Intestinal neuronal dysplasia (IND) of the colonic submucous plexus is considered to be a congenital malformation of the enteric nervous system causing symptoms resembling those of Hirschsprung's disease. In contrast with the established diagnosis of aganglionosis using enzyme histochemistry, controversy exists over the diagnostic criteria of IND on rectal biopsies previously defined by a consensus report and the causal relation between morphological findings and clinical symptoms. AIMS: The interobserver variability was prospectively investigated with respect to final diagnoses and several histological features in rectal biopsy specimens from children suspected of having colonic motility disturbances. METHODS: 377 biopsy specimens from 108 children aged 4 days to 15 years were independently coded without knowledge of clinical symptoms by three experienced pathologists for 20 histological features, and a final diagnosis was given for every case. Interobserver variation for the different items and the final diagnosis were analysed using Cohen's kappa statistic. Clinical data at biopsy and outcome after 12 months were related to morphological findings. RESULTS: The three pathologists agreed completely with respect to the diagnosis Hirschsprung's disease (kappa = 1), but in only 14% of the children without aganglionosis. In 15 (17%) of the 87 children without aganglionosis, at least one pathologist judged the case as normal, while another diagnosed IND. kappa values were close to the zero value expected by chance for the diagnoses normal and IND. Young age was related to the presence of several morphological features-for example, acetylcholine esterase staining and presence of giant ganglia. Children with chronic constipation diagnosed as having IND, given no other specific diagnosis by any of the pathologists, were significantly younger (median 8.8 months) and had a higher cure rate after one year (60%) than constipated patients considered by all observers to have no histological abnormalities (median 6.1 years, cure rate 23%). CONCLUSIONS: In contrast with Hirschsprung's disease, there is a high interobserver variation with regard to the different morphological features and final diagnosis of IND, based on the criteria and conditions of the previous consensus report. The high frequency of histological "abnormalities" in young infants suggests that some of the features may represent a normal variant of postnatal development rather than a pathological process. Investigations using more refined and morphometric methods in rectal specimens from infants and children without bowel disease are needed to define the normal range of morphological appearance at different ages. These preliminary data indicate that, with current knowledge, rectal biopsy for diagnostic purposes should only be performed in constipated children for diagnosis of Hirschsprung's disease.

Adolescent↗
PubMed1998

Impaired succinic dehydrogenase activity of rat Purkinje cell mitochondria during aging.

The perikaryal Purkinje cell mitochondria positive to the copper ferrocyanide histochemical reaction for succinic dehydrogenase (SDH) have been investigated by means of semiautomatic morphometric methods in rats of 3, 12 and 24 months of age. The number of organelles/microm3 of Purkinje cell cytoplasm (Numeric density: Nv), the average mitochondrial volume (V) and the mitochondrial volume fraction (Volume density: Vv) were the ultrastructural parameters taken into account. Nv was significantly higher at 12 than at 3 and 24 months of age. V was significantly decreased at 12 and 24 months of age, but no difference was envisaged between adult and old rats. Vv was significantly decreased in old animals vs. the other age groups. In young and old rats, the percentage of organelles larger than 0.32 microm3 was 13.5 and 11%, respectively, while these enlarged mitochondria accounted for less than 1% in the adult group. Since SDH activity is of critical importance when energy demand is high, the marked decrease of Vv supports an impaired capacity of the old Purkinje cells to match actual energy supply at sustained transmission of the nervous impulse. However, the high percentage of enlarged organelles found in old rats may witness a morphofunctional compensatory response.

Aging↗
PubMed1997

Clinical impact of intestinal neuronal malformations: a prospective study in 141 patients.

A prospective study of 141 consecutive patients with intestinal neuronal malformations is presented. The single malformation of the autonomic nervous system that always required surgical intervention was aganglionosis. Giant ganglia, reduced parasympathetic tone, immature ganglia, and hypogenetic or heterotopic nerve cells were seen in all forms of malformations. However, the incidence in specific malformations was variable. Multiple giant ganglia were identified in all patients with intestinal neuronal dysplasia (IND) type B, but also in various other malformations. Heterotopic nerve cells in the myenteric plexus were seen in the proximal segment of 15 of 74 patients (20.3%) with aganglionosis and 5 of 9 patients (55.6%) with hypoganglionosis. A significant impact on symptoms was found for IND type B: 34 (45.9%) of 74 children with aganglionosis had associated IND type B, and these children more frequently developed ileus (P < 0.001) and more often needed a second resection (P < 0.05) compared to those with isolated aganglionosis. This indicates an additive effect of both malformations, and therefore, in these patients an extended resection should be carried out. Twelve of 67 patients (17.9%) without aganglionosis needed resection for untreatable constipation. This included 7 of 9 children with hypoganglionosis, both patients with heterotopia of the myenteric plexus, 1 of 20 with isolated IND type B, and 2 of 12 with reduced parasympathetic tone. None of the patients with immaturity, heterotopia of the submucous plexus, or mild dysganglionosis required surgery. Six children (8.9%) without aganglionosis underwent sphincteromyotomy and 2 with IND type B had a temporary colostomy. At follow-up (mean 2.4 +/- 1.4 years), the outcome in patients with resected aganglionosis was better than in patients who had resections for other malformations; 49 (69%) of 71 patients with aganglionosis were asymptomatic compared to 4 (33.3%) of 12 with other malformations (P < 0.05). It is concluded that some intestinal malformations have a relevant clinical impact. However, the severity of symptoms in the individual patient may not be explained by specific histochemical findings from a limited number of mucosal biopsies. The pathognomonic histochemical criteria of isolated IND type B - immaturity, reduced parasympathetic tone, heterotopia of the submucous plexus, and mild dysganglionosis - rarely require surgical therapy and should be treated conservatively.

Child↗
PubMed1997

[Prospective study of the transit time in intestinal neuronal abnormalities].

In a prospective study 106 children with intestinal neuronal malformations underwent intestinal transit-time studies. In only 50% of the children with intestinal neuronal dysplasia type B or immature ganglia was the transit time prolonged. On the contrary, hypoganglionosis and heterotopia of the submucous plexus led to severe transport disorders with subsequent bowel resection.

Adolescent↗
PubMed1996

Age-dependent decrease in the activity of succinic dehydrogenase in rat CA1 pyramidal cells: a quantitative cytochemical study.

A computer-assisted morphometric study has been carried out on the ultrastructure of perikaryal CA1 pyramidal cell mitochondria positive to the copper ferricyanide cytochemical reaction for succinic dehydrogenase (SDH) in rats of 3, 12 and 23 months of age. The cytoplasmic volume fraction occupied by the positive mitochondria (Volume density: Vv), the number of organelles/micron 3 of CA1 pyramidal cell cytoplasm (Numerical density: Nv) and the average mitochondrial volume (V) were automatically calculated by means of computer-assisted morphometry. Vv was significantly decreased in 23-month-old animals versus the other age groups. Nv was unchanged between 3 and 12 months of age, but was decreased to a significant extent in old animals. V did not undergo significant changes in the three age groups taken into account. In the old animals the percent of organelles smaller than 0.16 micron 3 is above 20%, while in the young and adult groups the same size of mitochondria accounts for 7 and 3%, respectively. Thus, a reduction in the number of medium sized organelles appears to be responsible for the decrease in Vv due to age. Since SDH activity is known to support maximum rates of respiration, quantitative estimation of the active mitochondria provides information on the metabolic competence of the cells investigated when energy demand is high. In this context, our present findings document that a significant impairment in the efficiency to match actual energy provisions occurs in old CA1 pyramidal cells.

Age Factors↗
PubMed1996

Innervation patterns of the rectal pouch and fistula in anorectal malformations: a preliminary report.

The innervation patterns of the rectal pouch and fistula of 52 children with anorectal malformations were investigated. Posterior sagittal anorectoplasty was used for intermediate and high anomalies; for the latter it was combined with an abdominal approach. Perineoproctoplasty was performed for low anomalies. The specimens were investigated by acetylcholinesterase staining, lactate dehydrogenase, and succinyldehydrogenase reaction. They consisted of fistula material only in 23 patients and of parts of the rectal pouch in 29. Fourty-four patients (84.6%) had follow-up, and information of bowel movements and continence was obtained after a mean of 3.3 years. Abnormal innervation patterns were found in 96% of the specimens. All fistulas were found to be aganglionic, including the adjacent part of the rectum involving the internal sphincter equivalent. Classical aganglionosis was found in 31% of the rectal pouch specimens, hypoganglionosis in 38%, neuronal intestinal dysplasia (NID) type B in 14%, and dysganglionosis in 10%. All patients with severe constipation or soiling at the time of follow-up had some histopathological correlation. Of the 25 patients for whom the specimens had consisted of rectal pouch material, nine (31%) had severe constipation. All four patients with a low-type malformation who had follow-up and pathological innervation patterns in the rectal pouch suffered from severe constipation; this was true of only five of the 19 children with intermediate or high malformations (P < .05). However, numerous pathological innervation patterns had been identified in patients who had normal bowel function at the time of follow-up. It is concluded that partial denervation of the rectum may not be the only cause in the pathogenesis of constipation after posterior sagittal anorectoplasty and perineoproctoplasty. The high frequency of neuronal intestinal malformations in the rectal pouch may be related to the higher frequency of bowel disturbances in patients with low malformations, in whom the resection was less radical. However, the clinical course is not necessarily related to specific histopathological findings. In the authors' opinion, the recommendation to use the distal rectal pouch and parts of the fistula in the reconstruction of anorectal malformations should be reconsidered.

Anus, Imperforate↗
PubMed1996

Synaptic structural dynamics and aging.

Synaptic junctional areas are not immutable structures, on the contrary, they are remodelled throughout the individual's lifespan as a consequence of environmental stimulations. This adaptive capacity of the synapses is discussed from a morphological standpoint with reference to aging. In old subjects, the number of contacts and the total surface area of synaptic appositions per unit volume of tissue decrease significantly, while the average synaptic size increases at a different extent according to the CNS area taken into account. This increase in synaptic average area is due to a higher percent of a subpopulation of enlarged contacts supposed to represent either the degenerating junctional zones or a compensatory phenomenon counteracting the synaptic reduction in number. Recent studies on perforated synapses support that the enlarged junctions are possible intermediates in synaptic physiological restructuring, thus the higher percentage of this type of contacts in the old CNS may witness unaccomplished synaptic turnover cycles. Taking into account the high metabolic rate of nerve cells, an age-related impairment in energy provision at synaptic terminal regions may constitute an early and subtle alteration affecting synaptic dynamic morphology in aging.

Aging↗
PubMed1996

Morphologic changes in cerebellar mitochondria during aging.

OBJECTIVE: To seek age-dependent morphofunctional changes in mitochondrial metabolic competence in the rat cerebellum. STUDY DESIGN: Three-, 12- and 24-month-old female Wistar rats were used for the present study. Each group consisted of five animals. The cytoplasmic fraction occupied by mitochondria (volume density, Vu), number of organelles per cubic micrometer (numerical density, Nu) and mitochondrial average volume (V) were measured in Purkinje cell perikaryal organelles histochemically stained to reveal succinic dehydrogenase activity in the three groups analyzed. RESULTS: Vu did not show significant differences due to age. Nu was constant between 3 and 12 months of age but decreased significantly in old rats. V did not show significant age-dependent differences. CONCLUSION: The present findings further extend the results of our previous studies on the ultrastructure of synaptic mitochondria and support the concept of marked metabolic impairment as a basal detrimental condition in the process of brain aging. As a marker of metabolically active mitochondria at high rates of cellular respiration, our present data document that with advancing age the number of efficient organelles decreases and that this may be of critical importance for the proper function of nerve cells when the energy demand is high.

Aging↗