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Biomedical subjects

B Sattler

Publications and source records attributed to B Sattler.

At least 19 recordsLinked to original sources

Impact of vasoactive intestinal polypeptide and gastrin-releasing peptide on small bowel microcirculation and mucosal injury after hepatic ischemia/reperfusion in rats.

BACKGROUND AND AIMS: Alterations in microvascular perfusion of the intestine after hepatic ischemia/reperfusion have been suggested as an important cause of postoperative septic complications. We therefore investigated small bowel microcirculation and mucosal injury after liver ischemia/reperfusion in a rat model. Furthermore, we analyzed the effects of the regulatory peptides vasoactive intestinal polypeptide and gastrin-releasing peptide for their splanchnic vasoactivity. METHODS: Hepatic ischemia was induced by clamping of the left hepatic artery and vein for 40 min, followed by 60 min of reperfusion. The control group was treated similarly, but without clamping of the liver vessels. Ten minutes after clamping of the hepatic vessels, vasoactive intestinal polypeptide or gastrin-releasing peptide, respectively, were continuously infused intravenously in the experimental groups. Small bowel microcirculation and mucosal injury were assessed using intravital microscopy and the Chiu-score, respectively. RESULTS: The functional capillary density of the small intestine following ischemia and reperfusion of the left hepatic lobe significantly decreased compared to normal controls in both the mucosa and the smooth intestinal muscle. Red blood cell velocity decreased, whereas leukocyte-endothelium adherence, stasis index and the mucosal injury score increased. Administration of vasoactive intestinal polypeptide resulted in an increase of functional capillary density in the mucosa and of the red blood cell velocity and a decrease in the stasis index. The mucosal injury score was significantly higher in reperfused animals without treatment. The application of gastrin-releasing peptide resulted in an isolated increase of the red blood cell velocity. Leukocyte adherences could not be altered by the regulatory peptides. CONCLUSION: We conclude that hepatic ischemia/reperfusion injury leads to significant alterations of small bowel microcirculation and mucosal injury. Vasoactive intestinal polypeptide and gastrin-releasing peptide attenuate the damage in a different manner.

Animals↗

Expression of E-selectin and its transcripts during intestinal ischemia-reperfusion injury in pigs.

BACKGROUND: Ischemia-reperfusion injury (IRI) can result in severe organ dys- or nonfunction. Interaction of leukocytes and endothelial cells mediated by E-selectin appears to be a key step for disturbed microcirculation. Therefore we studied gene and protein expression as well as localization of E-selectin during intestinal IRI. METHODS: Intestinal tissue samples were obtained from extracorporeal perfused intestines (cold ischemia time [CIT] 2 or 20 hours, each n = 5) and additionally in intestinal transplanted pigs (CIT 2 or 20 hours, each n = 1). Mucosal damage was graded according to the Chiu classification. E-selectin mRNA was determined by PCR and quantitative RT-PCR. Localization of E-selectin mRNA was performed by in situ hybridization and of the protein by immunohistochemistry. RESULTS: Histologically, mucosal damage occurred during reperfusion and was earlier and more severe after 20 hours of CIT. E-selectin mRNA expression was detected by PCR already after laparotomy and was elevated after reperfusion. Interestingly, mRNA expression was already increased after 20 hours of CIT. E-selectin mRNA was localized to the luminal surface of muscular, submucosal, and mucosal endothelial cells and the protein was detected on submucosal arterial endothelium as early as 2 hours after reperfusion. CONCLUSION: Prolongation of CIT results in more severe mucosal damage during reperfusion, which is associated with protein expression of E-selection that might be used as a marker for activated endothelial cells. Increased E-selectin mRNA at end of 20 hours of CIT might indicate a preactivated state of endothelial cells potentially triggered by bacterial translocation or products.

Animals↗

Kinetics and localization of interleukin-2, interleukin-6, heat shock protein 70, and interferon gamma during intestinal-rerfusion injury.

BACKGROUND: Intestinal ischemia-reperfusion injury (IRI) represents an exaggerated inflammatory cascade with a complex pathophysiology. IL-2, IL-6, HSP70, and INF-gamma are mediators of the inflammatory process. Therefore, we investigated their kinetics and localization during intestinal IRI. METHODS: Pig intestinal specimens were obtained during cold preservation (cold ischemia time 2 hours) and extracorporeal perfusion. Mucosal damage was graded according to the Chiu classification. MRNA expression was determined by Northern blot (IL-2, IL-6, IFN-gamma) or by quantitative RT-PCR (IL-6, HSP70) and localized by in situ hybridization. RESULTS: Histologically, mucosal damage occurred during reperfusion. Expression of IL-2 mRNA was up-regulated after HTK perfusion and was highest at the start and 7 hours after reperfusion. Expression of IL-6 mRNA increased at 2 hours after reperfusion and HSP70 at 3 hours after reperfusion. IFN-gamma mRNA was expressed after HTK perfusion, with expression of this cytokine increasing to 1 hour after the start of reperfusion, and decreasing thereafter. IL-2 mRNA was localized to endothelial cells (EC) and leukocytes and in close relation to ganglion cells (GC): IL-6 mRNA in EC, smooth muscle cells (SMC), and GC: HSP70 mRNA in EC and SMC; and IFN-gamma mRNA in leukocytes. CONCLUSION: IL-2, IL-6, HSP70, and INF-gamma are parameters of early mRNA expression during intestinal IRI. EC, SMC, leukocytes, and GC have been identified as sources of transcripts that might afford potential targets for intervention strategies to attenuate IRI.

Animals↗

Reduction of severe ischemia/reperfusion injury in rat kidney grafts by a soluble P-selectin glycoprotein ligand.

BACKGROUND: Inflammatory leukocyte-endothelium interactions, mediated by selectins, contribute to renal ischemia/reperfusion (I/R) injury. We examined the influence of the soluble P-selectin glycoprotein ligand 1 (sPSGL) on early I/R-induced changes in a rat kidney transplantation model with long cold ischemia. METHODS: After 24 hr of cold storage, syngeneic kidneys were grafted into bilaterally nephrectomized rats. Before transplantation, recipients received either 1 mg/kg of sPSGL or vehicle (n=8 per group). Six hours after reperfusion, grafts were removed for light microscopy and immunohistochemistry. Capillary blood flow was measured under a fluorescence microscope by using the concentric-circles method. RESULTS: A greater proportion, 74.7+/-7.2% (sPSGL) vs. 28+/-7.4% (controls), of all dye-labeled outer medullary capillaries appeared in the 12-microm radius (P<0.01), indicating dense blood flow, whereas 7.6+/-2.9% vs. 43.3+/-9.7%, respectively, appeared in the 60-microm radius (P<0.05), indicating rarefied blood flow. In the sPSGL-treated group, the extent of severe tubular damage within the inner stripe of the outer medulla was lower compared with controls (37.5+/-8.3% vs. 78.4+/-3.5%, P<0.01). Outer medullary heat shock protein 72 expression was 14.5+/-1.6% in the sPSGL-treated group compared with 9.6+/-1.4% in controls (P<0.05). The number of infiltrating polymorphonuclear leukocytes was similar in both groups. Treatment with sPSGL had no influence on the serum creatinine level. CONCLUSIONS: Our data suggest that impairment of outer medullary blood flow is crucial in I/R injury of kidney grafts with prolonged cold storage. Reduction of capillary blood flow perturbations by sPSGL protects tubular cells from severe structural damage. Blocking early selectin-mediated leukocyte adhesion may have therapeutic implications in improving the prognosis of renal transplants with severe I/R injury.

Animals↗

Phylogenetic and functional heterogeneity of sediment biofilms along environmental gradients in a glacial stream.

We used in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes concurrently with measurements of bacterial carbon production, biomass, and extracellular polymeric substances (EPS) to describe the bacterial community in sediments along a glacial stream. The abundance of sediment-associated Archaea, as detected with the ARCH915 probe, decreased downstream of the glacier snout, and a major storm increased their relative abundance by a factor of 5.5 to 7.9. Bacteria of the Cytophaga-Flavobacterium group were also sixfold to eightfold more abundant in the storm aftermath. Furthermore, elevated numbers of Archaea and members of the Cytophaga-Flavobacterium group characterized the phylogenetic composition of the supraglacial ice community. We postulate that glacial meltwaters constitute a possible source of allochthonous bacteria to the stream biofilms. Although stream water temperature increased dramatically from the glacier snout along the stream (3.5 km), sediment chlorophyll a was the best predictor for bacterial carbon production and specific growth rates along the stream. Concomitant with an increase in sediment chlorophyll a, the EPS carbohydrate-to-bacterial-cell ratio declined 11- to 15-fold along the stream prior to the storm, which is indicative of a larger biofilm matrix in upstream reaches. We assume that a larger biofilm matrix is required to assure prolonged transient storage and enzymatic processing of allochthonous macromolecules, which are likely the major substrate for microbial heterotrophs. Bacteria of the Cytophaga-Flavobacterium cluster, which are well known to degrade complex macromolecules, were most abundant in these stream reaches. Downstream, higher algal biomass continuously supplies heterotrophs with easily available exudates, therefore making a larger matrix unnecessary. As a result, bacterial carbon production and specific growth rates were higher in downstream reaches.

Archaea↗

Androblastoma of the ovary: clinical, diagnostic and histopathologic features.

Androblastomas of Sertoli-Leydig cell tumors of the ovaries are classified into the group of sex cord stromal tumors and represent an extremely rare form of tumor (0.2% of all ovarian tumors) in women. Their malignant potential is lower than that of epithelial ovarian cancer. They cause signs of virilization, although these are not obligatory. In many cases secondary amenorrhea is the only symptom of the disease. This leads to an intensive search for the source of the disorder. Frequently only the elevated production of androgens gives a preoperative clue to the tumor type. The recommendation to include the measurement of androgen levels in the routine diagnosis of secondary amenorrhea must therefore be endorsed. The tumors are usually sonographically identifiable; in differential diagnosis, hyperandrogenemia of other origins (e.g., Cushing's disease, adrenal hyperplasia, pituitary adenoma, other causes of ovarian and adrenal androgen hypersecretion, intersexuality, medically induced androgenization) have to be ruled out. In view of the good prognosis, the therapy of choice consists simply in adnexectomy of the affected side. With regular measurement of serum androgen levels an effective control of the course of the disorder is possible. A conclusive pathological diagnosis is difficult as heterologous tumors and mixed tumors exist and, furthermore, other tumor types are capable of imitating Sertoli-Leydig cell tumors.

Androgens↗

[Undifferentiated small-cell hepatoblastoma].

Undifferentiated small-cell hepatoblastoma (HB) is a rare malignant tumor of childhood. The cell of origin is supposed to be a pluripotential, probably entodermal, stem-cell. Differential diagnosis of this type of HB is difficult among the group of small round and blue cell malignant tumors of children. The immunohistochemically determined coexpression of cytokeratin 8, 18, and 19 and of vimentin and actin, regularly in the absence of alpha-fetoprotein expression may be diagnostically helpful. We present the case of an undifferentiated small-cell HB of a 15-month-old girl with agenesis of the right kidney. As morphological peculiarity the tumor presented disseminated histiocytic giant cells.

Actins↗

Basic fibroblast growth factor expression is increased in human renal fibrogenesis and may mediate autocrine fibroblast proliferation.

BACKGROUND: Interstitial fibroblasts play a critical role in renal fibrogenesis, and autocrine proliferation of these cells may account for continuous matrix synthesis. Basic fibroblast growth factor (FGF-2) is mitogenic for most cells and exerts intracrine, autocrine, and paracrine effects on epithelial and mesenchymal cells. The aims of the present studies were to localize and quantitate the expression of FGF-2 in normal and pathologic human kidneys and to study the in vitro effects of FGF-2 on proliferation, differentiation, and matrix production of isolated cortical kidney fibroblasts. METHODS: FGF-2 protein expression was localized by immunofluoresence double labelings in normal and fibrotic human kidneys. Subsequently, interstitial FGF-2 labeling was determined semiquantitatively in 8 normal kidneys and 39 kidneys with variable degrees of interstitial fibrosis and was correlated with the morphometrically determined interstitial cortical volume. In addition, FGF-2 expression was quantitated by immunoblot analysis in three normal and six fibrotic kidneys. FGF-2 mRNA was localized by in situ hybridizations. Seven primary cortical fibroblast lines were established, and expression of FGF-2 and FGF receptor-1 (FGFR-1) were examined. The effects of FGF-2 on cell proliferation were determined by bromodeoxyuridine incorporation and cell counts, those on differentiation into myofibroblasts by staining for alpha-smooth muscle actin, and those on matrix synthesis by enzyme-linked immunosorbent assay for collagen type I and fibronectin. Finally, proliferative activity in vivo was evaluated by expression of MIB-1 (Ki-67 antigen). RESULTS: In normal kidneys, FGF-2 expression was confined to glomerular, vascular, and a few tubular as well as interstitial fibroblast-like cells. The expression of FGF-2 protein was increased in human kidneys, with tubulointerstitial scarring correlating with the degree of interstitial fibrosis (r = 0.84, P < 0.01). Immunoblot analyses confirmed a significant increase in FGF-2 protein expression in kidneys with interstitial scarring. In situ hybridization studies demonstrated low-level detection of FGF-2 mRNA in normal kidneys. However, FGF-2 mRNA expression was robustly up-regulated in interstitial and tubular cells in end-stage kidneys, indicating that these cells are the source of excess FGF-2 protein. Primary cortical fibroblasts express FGF-2 and FGFR-1 in vitro. FGF-2 induced a robust growth response in these cells that could be blocked specifically by a neutralizing FGF-2 antibody. Interestingly, the addition of the neutralizing antibody alone did reduce basal proliferation up to 31.5%. In addition, FGF-2 induced expression of alpha-smooth muscle actin up to 1.6-fold, but no significant effect was observed on the synthesis of collagen type I and fibronectin. Finally, staining for MIB-1 revealed a good correlation of interstitial FGF-2 positivity with interstitial and tubular proliferative activity (r = 0.71, P < 0.01 for interstitial proliferation, N = 30). CONCLUSIONS: Interstitial FGF-2 protein and mRNA expression correlate with interstitial scarring. FGF-2 is a strong mitogen for cortical kidney fibroblasts and may promote autocrine fibroblast growth. Expression of FGF-2 correlates with interstitial and tubular proliferation in vivo.

Adult↗

[Malignant fibrous histiocytoma of the liver].

We report on a 43-year-old man with a primary sarcoma of the liver. The patient was admitted to the hospital for evaluation of dyspnea, abdominal pain in the right upper quadrant, diarrhea, and fever. Physical examination revealed hepatomegaly. Increased laboratory values were found for gamma-GT, LDH, CA 125, and NSE, but not for aspartate and alanine aminotransferase. Computed tomography presented a tumor in the right lobe of the liver. Venous cavography revealed a caval tumor thrombus reaching up to the right atrium. Major liver resection combined with replacement of the vena cava inferior was proposed, but before operation the patient complained about shortness of breath. Spontaneous fragmentation of the tumor thrombus with consecutive embolization of the lungs was suspected. Despite lysis therapy the patient died because of right ventricular failure. Autopsy revealed a tumor measuring 8 cm in diameter, which was located in the right lobe of the liver and invaded the inferior vena cava. Because of multiple tumor aggregates seen in the left and right main pulmonary arteries acute tumor embolization of the lungs was regarded as cause of death. Histologically the tumor was composed of bizarre giant cells surrounded by irregular spindle cells. The positive immunoreactivity pattern of the tumor cells for vimentin, lysozym, and CD68 justified the diagnosis of a malignant fibrous histocytoma (MFH) of the liver.

Adult↗

Two brothers with Hennekam syndrome and cerebral abnormalities.

We report two brothers with mental retardation, lymphoedema of the limbs and facial anomalies. Hennekam et al. (Am J Med Genet 34:593-600; 1989) described four patients with identical signs and intestinal lymphangiectasia. To confirm the diagnosis of Hennekam syndrome we undertook a duodenal biopsy from the older brother which revealed intestinal lymphangiectasia. So far only one patient with Hennekam syndrome and cerebral abnormalities has been described. This patient presented with pachygyria in the parietal area. Cerebral MRI in our two cases revealed small subcortical hyperintensities in both patients and a large cystic lesion in the younger patient probably representing an old media infarction.

Abnormalities, Multiple↗

[Surgical treatment of cholangiocellular carcinoma and proximal bile duct tumors].

According to its different location, clinical features, treatment modalities and prognosis, intrahepatic cholangiocarcinoma should be well differentiated from proximal bile duct carcinoma. There is no therapeutic measure with curative potential apart from surgical treatment. Partial or extended hepatectomy is the treatment of choice in cholangiocarcinoma. Thereby, hilar resection in combination with hepatectomy is increasingly performed in proximal bile duct carcinomas. In most centers liver transplantation is not considered as a therapeutic option for irresectable cholangiocarcinomas.

Adult↗

[Rapidly progressing renal insufficiency as the primary manifestation of systemic sarcoidosis].

CASE REPORT: We report the history of a 67-year-old patient who was admitted to hospital because of rapidly progressive renal insufficiency. The renal biopsy revealed granulomatous interstitial nephritis. The diagnosis of systemic sarcoidosis was confirmed by typical findings of bronchoalveolar lavage and of transbronchial, liver and bone marrow biopsy. Indications for sarcoidosis-related nephrocalcinosis/nephrolithiasis or glomerulonephritis were absent. Simultaneously a monoclonal gammopathy of unknown significance (MGUS) was diagnosed. While the patient having been uremic at the time of diagnosis, the administration of prednisolone effectively improved renal function. CONCLUSIONS: As a rare manifestation of sarcoidosis granulomatous interstitial nephritis can cause rapidly progressive renal insufficiency, which can effectively be treated by steroids, if distinct interstitial fibrosis is absent.

Acute Kidney Injury↗