Influence of mesh materials on collagen deposition in a rat model.

Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material.     

Early alcoholic liver injury: Activation of lipocytes in acinar zone 3 and correlation to degree of collagen formation in the disse space

Acinar zone 3 areas in liver biopsy specimens from 23 alcoholics and 47 non-alcoholics were investigated by light microscopy and transmission electron microscopy to asses fibrosis in the perisinusoidal space and to evaluate the role of the lipocytes. Quantitative analysis by light microscopy on toluidine blue-stained sections showed a significant reduction in number of lipocytes--median values of 2.7 and 1.2 lipocytes per 100 hepatocytes in biopsies from chronic alcoholics showing no or varying degrees of zone 3 fibrosis, respectively, as compared to 3.6 lipocytes per 100 hepatocytes in non-alcoholic livers. By transmission electron microscopy, the reduction in number of lipocytes was related to a corresponding increase in number of cells rich in rough endoplasmic reticulum and microfilaments (activated lipocytes). The occurrence of activated cells was significantly correlated to fibrosis of the perisinusoidal space. Activation of lipocytes and collagenization of the perisinusoidal space appeared before light microscopic evidence of fibrosis and were topographically not related to Mallory bodies or alcoholic hepatitis.     

Influence of pneumoperitoneum on small bowel anastomoses: a histological analysis in the rat model.

Laparoscopic techniques are increasingly applied for the treatment of diverse gastrointestinal diseases. With regard to reports of a pronounced decrease of intra-abdominal blood flow with increasing intra-abdominal pressure, the present study investigates the impact of pressure and gas type on ischemia in small bowel anastomoses in the rat model. Laparotomy and ileoileal anastomosis were performed in 39 male Sprague-Dawley rats. A CO2 or helium pneumoperitoneum of 3 mm Hg or of 6 mm Hg was maintained before and after anastomoses. Rats in the control group received no pneumoperitoneum. Animals were sacrificed after 5 d, and the anastomotic region was explanted for subsequent histopathological examinations. In hematoxylin and eosin (HE)-stained sections, the Chiu score, villi configuration, and number of goblet cells were analyzed. Proliferation (Ki67) and expression of a matrix metalloproteinase (MMP-8) were examined by immunohistochemistry. Mucosal damage according to the scoring system by Chiu, the number of goblet cells, the villus length, the proliferation (Ki67), and the submucosal expression of MMP-8 was similar in all groups. Our results suggest that within a certain range of pressures and time, laparoscopic assisted surgery using CO2 pneumoperitoneum can be performed safely. Helium gas offers no advantages over CO2.     

Große solitäre fibröse Tumoren der Pleura als Zufallsbefund

The solitary fibrous tumor (SFT) is a very rare and usually benign neoplasm. This tumor is mostly located in the thoracic cavity, but it has also been reported in numerous sites including liver, skin, and meninges. Due to its rarity diagnosis is often difficult. Accordingly, histopathological differentiation is of major importance. Solitary fibrous tumors consistently express CD 34 and react negatively to epithelial markers. This absence of expression of epithelial markers, especially cytokeratin, is also useful to distinguish these rare entities from sarcomatous mesotheliomas. The treatment of choice for solitary fibrous tumors is extensive surgical resection. Up to now there is no evidence that radiation and chemotherapy are effective. The local recurrence or onset of metastases depends on histologic parameters. In cases of benign classification (60-80%), the recurrence rate was only 2% after surgical excision. One-half of the patients with malignant tumors can be cured; the rest develop recurrences and metastases more often. Especially in those cases, emphasis should be placed on continual follow-up examination. We report two cases of a 65- and a 75-year-old male patient with huge intrathoracic solitary fibrous subpleural tumors, discovered incidentally on routine chest X-ray.     

Biomaterial-dependent MMP-2 expression in fibroblasts from patients with recurrent incisional hernias

With regard to the pathogenesis of recurrent incisional hernia, an impaired connective tissue quality leading to an aberrant scarring process has been proposed. For the matrix metalloproteinase (MMP-2) a pathogenetic involvement in direct inguinal hernia development is reported. With mesh implantation as the gold standard treatment for incisional hernias, the aim of the present study was to investigate the MMP-2 expression in patients with recurrent incisional hernias with and without mesh-materials. In primary fibroblast cultures obtained from skin scars in patients with and without recurrent incisional hernias, MMP-2 synthesis and gene expression were investigated. Furthermore, MMP-2 synthesis and gene expression of fibroblasts were compared after incubation with two different mesh materials: polypropylene and absorbable polyglactin filaments. MMP-2 enzyme activity was determined by semiquantitative zymography and mRNA synthesis by quantitative RT-PCR. Both MMP-2 enzyme activity and mRNA expression were similar in hernia and control fibroblasts in vitro. In control fibroblasts mesh incubation did not significantly affect MMP-2 expression, whereas polypropylene mesh contact of fibroblasts from patients with recurrent incisional hernias led to a major decrease of MMP-2 activity and of mRNA expression. In the absence of biomaterials fibroblasts from recurrent incisional hernia, patients have no alterations of their MMP-2 synthesis compared to control fibroblasts, whereas a specific response was found after biomaterial contact hereby indicating differences in fibroblast phenotype. This work was supported by IZKF-BIOMAT, RWTH-Aachen, project no. TV B66 and by the Deutsche Forschungsgemeinschaft grant KL 1320/2-1     

Difficulties in the occupational incorporation of the mentally handicapped

Psychiatric clinics report great difficulties in motivating patients, on successful completion of medical rehabilitation and vocational therapy, to file an application for vocational rehabilitation. And if they do so, the mentally ill persons more frequently then other disabled persons break off the vocational rehabilitation measures taken. After a two year discussion process, a study group in Berlin (West), which consisted of representatives of different institutions involved in vocational rehabilitation, have published a memorandum stating the central obstacles for mentally ill persons to enter and remain in a "Workshop for Disabled." Proposals are made how to improve the situation.     

Mild phenotype in two unrelated patients with a partial deletion of 21q22.2-q22.3 defined by FISH and molecular studies

We describe two unrelated patients with cytogenetically visible deletions of 21q22.2-q22.3 and mild phenotypes. Both patients presented minor dysmorphic features including thin marfanoid build, facial asymmetry, downward-slanting palpebral fissures, depressed nasal bridge, small nose with bulbous tip, and mild mental retardation (MR). FISH and molecular studies indicated common deleted areas but different breakpoints. In patient 1, the breakpoint was fine mapped to a 5.2 kb interval between exon 5 and exon 8 of the ETS2 gene. The subtelomeric FISH probe was absent on one homologue 21 indicating a terminal deletion spanning approximately 7.9 Mb in size. In patient 2, the proximal breakpoint was determined to be 300-700 kb distal to ETS2, and the distal breakpoint 2.5-0.3 Mb from the 21q telomere, indicating an interstitial deletion sized approximately 4.7-7.3 Mb. The 21q- syndrome is rare and typically associated with a severe phenotype, but different outcomes depending on the size and location of the deleted area have been reported. Our data show that monosomy 21q of the area distal to the ETS2 gene, representing the terminal 7.9 Mb of 21q, may result in mild phenotypes comprising facial anomalies, thin marfanoid build, and mild MR, with or without signs of holoprosencephaly.