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Biomedical subjects

P Vogel

Publications and source records attributed to P Vogel.

At least 55 records · Page 3Linked to original sources
PubMed2000

Prognostic value of microscopic peritoneal dissemination: comparison between colon and gastric cancer.

PURPOSE: We evaluated the incidence and prognostic relevance of microscopic intraperitoneal tumor cell dissemination of colon cancer in comparison with dissemination of gastric cancer as a rational for additive intraperitoneal therapy. METHODS: Peritoneal washouts of 90 patients with colon and 111 patients with gastric cancer were investigated prospectively. Sixty patients with benign diseases and 8 patients with histologically proven gross visible peritoneal carcinomatosis served as controls. Intraoperatively, 100 ml of warm NaCl 0.9 percent were instilled and 20 ml were reaspirated. In all patients hematoxylin and eosin staining (conventional cytology) was performed. Additionally, in 36 patients with colon cancer and 47 patients with gastric cancer, immunostaining with the HEA-125 antibody (immunocytology) was prepared. The results of cytology were assessed for an association with TNM category and cancer grade, based on all patients, and with patient survival, among the R0 resected patients. RESULTS: In conventional cytology 35.5 percent (32/90) of patients with colon cancer and 42.3 percent (47/111) of patients with gastric cancer had a positive cytology. In immunocytology 47.2 percent (17/36) of patients with colon cancer and 46.8 percent (22/47) of patients with gastric cancer were positive. In colon cancer, positive conventional cytology was associated with pT and M category (P = 0.044 and P = 0.0002), whereas immunocytology was only associated with M category (P = 0.007). No association was found between nodal status and immunocytology in colon cancer and with the grading. There was a statistically significant correlation between pT M category and conventional and immunocytology in gastric cancer (P < 0.0015/P = 0.007 and P < 0.001/P = 0.009, respectively). Positive immunocytology was additionally associated with pN category (P = 0.05). In a univariate analysis of R0 resected patients (no residual tumor), positive immunocytology was significantly related to an unfavorable prognosis in patients with gastric cancer only (n = 30). Mean survival time was significantly increased in patients with gastric cancer with negative cytology compared with positive cytology (1,205 (standard error of the mean, 91) vs. 771 (standard error of the mean, 147) days; P = 0.007) but not in patients with colon cancer (1,215 (standard error of the mean, 95) vs. 1,346 (standard error of the mean, 106) days; P = 0.55). CONCLUSIONS: Because microscopic peritoneal dissemination influences survival time after R0 resections only in patients with gastric but not with colon cancer, our results may provide a basis for a decision on additive, prophylactic (intraperitoneal) therapy in gastric but not colon cancer.

Analysis of Variance↗
PubMed2000

Mouse model of sublethal and lethal intraperitoneal glanders (Burkholderia mallei).

Sixty male BALB/c mice were inoculated intraperitoneally with either a sublethal or a lethal dose of Burkholderia mallei China 7 strain, then killed at multiple time points postinoculation. Histopathologic changes were qualitatively similar in both groups and consisted of pyogranulomatous inflammation. In sublethal study mice, changes were first seen at 6 hours in mediastinal lymph nodes, then in spleen, liver, peripheral lymph nodes, and bone marrow at day 3. These changes generally reached maximal incidence and severity by day 4 but decreased by comparison in all tissues except the liver. Changes were first seen in lethal study mice also at 6 hours in mediastinal lymph nodes and in spleens. At day 1, changes were present in liver, peripheral lymph nodes, and bone marrow. The incidence and severity of these changes were maximal at day 2. In contrast to sublethal study mice, the incidence and severity of the changes did not decrease through the remainder of the study. The most significant difference between the two groups was the rapid involvement of the spleen in the lethal study mice. Changes indicative of impaired vascular perfusion were more frequently seen in the sublethal study mice. Our findings indicate that mice are susceptible to B. mallei infection and may serve as an appropriate model for glanders infection in a resistant host such as human beings. Additionally, by immunoelectron microscopy, we showed the presence of type I O-antigenic polysaccharide (capsular) antigen surrounding B. mallei.

Animals↗
PubMed1999

Biphasic expression of TGF-beta1 mRNA in the rat brain following permanent occlusion of the middle cerebral artery.

Two patterns of transforming growth factor-beta1 (TGF-beta1) expression were identified in brains of normotensive rats following permanent occlusion of the middle cerebral artery (MCAO). First, a relative increase of TGF-beta1 mRNA by 37% was found at 12 h after MCAO in the ipsilateral cingulate cortex as compared to the homotopic contralateral region. The cingulate cortex is located distant from the ischemic territory. Treatment with the glutamate receptor antagonists MK-801 and NBQX did not reduce this expression (34% and 26% increase, respectively). Therefore, peri-infarct depolarization waves were probably not responsible for induction. Secondly, an increase of TGF-beta1 mRNA by 116% was found at 7 days after MCAO within infarcted tissue. This expression was not reduced by the glutamate receptor antagonists MK-801 (increase 140%) and NBQX (increase 137%), either. TGF-beta1 mRNA expression in the cingulate cortex at 12 h after MCAO is possibly mediated by neurons and astroglia and may support cell survival. Expression in the infarcted tissue at 7 days after MCAO is most likely related to the invasion of monocytes and may be involved in the downregulation of inflammatory events, in neoangiogenesis, and in formation of a glial scar around the infarct.

Animals↗
PubMed1999

Global cerebral ischemia due to cardiocirculatory arrest in mice causes neuronal degeneration and early induction of transcription factor genes in the hippocampus.

To analyze the role of specific genes and proteins in neuronal signaling cascades following global cerebral ischemia, it would be useful to have a reproducible model of global cerebral ischemia in mice that potentially allows the investigation of mice with specific genomic mutations. We first report on the development of a model of reversible cardiocirculatory arrest in mice and the consequences of such an insult to neuronal degeneration and expression of immediate early genes (IEG) in the hippocampus. Cardiocirculatory arrest of 5 min duration was induced via ventricular fibrillation in mechanically ventilated NMRI mice. After successful cardiopulmonary resuscitation (CPR), animals were allowed to reperfuse spontaneously for 3 h (n=7) and 7 days (n=7). TUNEL staining revealed a selective degeneration of a subset of neurons in the hippocampal CA1 sector at 7 days. About 30% of all TUNEL-positive nuclei showed condensed chromatin and apoptotic bodies. Immunohistochemical studies of IEG expression performed at 3 h exhibited a marked induction of c-Fos, c-Jun, and Krox-24 protein in all sectors of the hippocampus, peaking in vulnerable CA1 pyramidal neurons and in dentate gyrus. In contrast, sham-operated animals (n=3) did not reveal neuronal degeneration or increased IEG expression in the hippocampus when compared with untreated control animals (n=3). In conclusion, we present a new model of global cerebral ischemia and reperfusion in mice with the use of complete cardiocirculatory arrest and subsequent CPR. Following 5 min of ischemia, a subset of CA1 pyramidal neurons was TUNEL-positive at 7 days. The expression of IEG was observed in all sectors of the hippocampus, including selectively vulnerable CA1 pyramidal neurons. This appears to be a good model which should be useful in evaluating the role of various genes in transgenic and knockout mice following global ischemia.

Animals↗
PubMed1999

Specific, uncompetitive inhibition of beta-galactosidases by a 5,6-isopropylidenedioxyfuro[2,3-d]isoxazole-3-methanol derivative.

(-)-(3aS,5S,6S.6aR)-3a,5,6,6a-Tetrahydro-5,6-isopropylide nedioxyfuro [2,3-d]isoxazole-3-methanol ((-)-5) has been tested toward 25 glycohydrolases and found to inhibit beta-galactosidase from Aspergillus niger (Ki = 18 microM) and that from Aspergillus orizae (Ki = 72 microM). Hydrolysis of the acetonide or exchange of CH2OH group for a CHO, CH2OMe or a CH2OMOM group suppresses the inhibitory activity.

Aspergillus↗
PubMed1999

Molecular phylogeny and evolution of Sorex shrews (Soricidae: insectivora) inferred from mitochondrial DNA sequence data.

Shrews of the genus Sorex are characterized by a Holarctic distribution, and relationships among extant taxa have never been fully resolved. Phylogenies have been proposed based on morphological, karyological, and biochemical comparisons, but these analyses often produced controversial and contradictory results. Phylogenetic analyses of partial mitochondrial cytochrome b gene sequences (1011 bp) were used to examine the relationships among 27 Sorex species. The molecular data suggest that Sorex comprises two major monophyletic lineages, one restricted mostly to the New World and one with a primarily Palearctic distribution. Furthermore, several sister-species relationships are revealed by the analysis. Based on the split between the Soricinae and Crocidurinae subfamilies, we used a 95% confidence interval for both the calibration of a molecular clock and the subsequent calculation of major diversification events within the genus Sorex. Our analysis does not support an unambiguous acceleration of the molecular clock in shrews, the estimated rate being similar to other estimates of mammalian mitochondrial clocks. In addition, the data presented here indicate that estimates from the fossil record greatly underestimate divergence dates among Sorex taxa.

Animals↗
PubMed1999

Seroepidemiology of Helicobacter pylori infection in a Jamaican community.

We researched epidemiologic associations between environmental and demographic factors and prevalence of Helicobacter pylori infection in a suburban Jamaican community. Using a clustered sampling technique, 22 domestic yards enclosing 60 separate households were randomly selected from a local community. All household members (n = 346) were invited to participate following informed consent; the overall compliance rate was 58.9%. A commercial enzyme immunoassay (HMáCAP) was used to detect IgG antibodies raised against H. pylori. Environmental and demographic information was obtained by questionnaire. The seroprevalence of H. pylori was 69.9% (n = 202). Analysis of the independent variables revealed three major components: Component 1 described, collectively, good personal hygiene and sanitation, indoor water supply and absence of straying animals in the peridomestic area; Component 2 included older age, good personal hygiene and large yard size; Component 3 the presence of domestic animals (cats and dogs) and, again, large yard size. These three complexes explained 42.2% of the variability in the data set. Logistic regression showed that Components 2 and 3 were independently associated with H. pylori seropositivity, indicating that a combination of demographic, environmental and zoonotic factors is involved in the spread of H. pylori infections at the tropical community level.

Adolescent↗
PubMed1999

Immunocytology improves prognostic impact of peritoneal tumour cell detection compared to conventional cytology in gastric cancer.

AIMS: Studies on the value of peritoneal tumour cell dissemination for prognosis in gastric cancer using various methods to detect tumour cells have produced conflicting conclusions. We studied the incidence and prognostic relevance of microscopic intraperitoneal tumour cell dissemination in gastric cancer, comparing conventional and immunocytological detection. METHODS: Peritoneal wash-outs of 111 consecutive gastric patients without overt peritoneal carcinomatosis, including 75 curatively resected patients, were studied. Sixty patients with benign disorders served as controls. 100 ml of warm NaCl 0.9% was instilled intraoperatively and 20 ml was reaspirated. The specimens were stained peri-operatively with H&E. In the last 47 patients (30 of whom were curatively resected) additional immunostaining with the HEA-125 antibody was performed. The results of cytology were correlated with the TNM categories and with post-operative follow-up. RESULTS: Of the patients, 42.3% and 48.9% were positive when conventional and immunocytological staining were employed, respectively. Conventional cytology was significantly associated with the pT and M categories. Immunocytology was significantly associated with the pT, pN and M caterogies. In four of 30 curatively resected patients (13.3%), the results of conventional and immunocytology were different. Three patients with positive immunocytology but negative conventional cytology died during follow-up (median follow-up 45.3 months), whereas one patient with positive conventional but negative immunocytology is still alive. In an univariate analysis 4 years post-surgery, positive immunocytology was significantly associated with an unfavourable prognosis in patients with curatively resected gastric cancer. While only 28.6% (six of 21) of the patients with negative immunocytology had died, this proportion increased to 77.8% (seven of nine) with positive immunocytology (P=0.018). The mean survival of negative vs positive patients amounted to 1205+/-91 vs 772+/-147 days (P=0.007). In contrast, in conventional cytology we found no significantly different survival time between negative and positive patients. CONCLUSIONS: Immunocytology seems to be superior to conventional cytology and should be preferred.

Case-Control Studies↗
PubMed1999

The kidney during hibernation and arousal from hibernation. A natural model of organ preservation during cold ischaemia and reperfusion.

BACKGROUND: During hibernation the kidney is in a hypothermic condition where renal blood flow is minimal and urine production is much reduced. Periodical arousal from hibernation is associated with kidney reperfusion at increasing body temperature, and restored urine production rate. METHODS: To assess the degree of structural preservation during such extreme conditions, the kidney cortex was investigated by means of electron microscopy in the dormouse Muscardinus avellanarius during winter hibernation, arousal from hibernation and the summer active period. RESULTS: Results show that the fine structure of the kidney cortex is well preserved during hibernation. In the renal corpuscle, a sign of slight lesion was the focal presence of oedematous endothelial cells and/or podocytes. Proximal convoluted tubule cells showed fully preserved ultrastructure and polarity, and hypertrophic apical endocytic apparatus. Structural changes were associated with increased plasma electrolytes, creatinine and urea nitrogen, and proteinuria. During the process of arousal the fine structure of the kidney cortex was also well maintained. CONCLUSION: These results demonstrate that dormice are able to fully preserve kidney cortex structure under extreme conditions resembling e.g. severe ischaemia or hypothermic organ storage for transplantation, and reperfusion. Elucidation of the mechanisms involved in such a natural model of organ preservation could be relevant to human medicine.

Animals↗
PubMed1999

The hamster model of intraperitoneal Burkholderia mallei (glanders).

Thirty-one female Syrian hamsters (Mesocricetus auratus) were inoculated intraperitoneally with a lethal dose of Burkholderia mallei (Budapest strain). Hamsters were killed postinoculation on days 0 through 6. Lesions were first noted in the spleens on postinoculation day 1, and in mediastinal and mesenteric lymph nodes, mediastinum, liver, and bone marrow on day 2. Lesions were present in the lung and submandibular lymph nodes on day 3, and in the brain on day 5. The characteristic histopathologic change was necrotizing pyogranulomatous inflammation, often with hemorrhage. Lesions indicative of impaired vascular perfusion, such as ischemia and infarction, were evident at the later time points. Pathologic changes generally increased in severity and distribution with time, and almost all tissues were ultimately affected. Our findings suggest that intraperitoneal bacteria were rapidly transported to mediastinal lymph nodes by transdiaphragmatic lymphatics and ultimately seeded other tissues hematogenously. The results of the study indicate that the Syrian hamster is a useful small animal model for glanders.

Animals↗
PubMed1999

Treatment of carotid artery stenosis by elective stent placement instead of carotid endarterectomy in patients with severe coronary artery disease.

Patients with concomitant cardiac and cerebrovascular disease undergoing revascularization procedures are at high risk of both, cardiac and cerebrovascular complications. The purpose of our study was to evaluate the feasibility of prior elective carotid artery stenting as an alternative treatment procedure to carotid endarterectomy (CEA) in patients with concomitant coronary artery disease (CAD), who clearly needed coronary revascularization. We offered extracranial internal carotid stenting to 85 patients with 89 significant carotid stenoses. Out of these, 19 patients were symptomatic. The quantitative mean reduction in diameter was 77 +/- 11%. Stent implantation was successful in 88 lesions. Two disabling major and 3 reversible minor strokes occurred periprocedurally. Three patients showed asymptomatic restenosis and stent deformation was detected in 2 patients. Based on this experience, carotid stenting in high risk patients with severe coronary artery disease is feasible and safe and might be indicated as an alternative procedure for combined surgery.

Adult↗
PubMed1998

Carbaxylosides of 4-ethyl-2-oxo-2H-benzopyran-7-yl as non-hydrolyzable, orally active venous antithrombotic agents.

A (-)-conduritol F derivative was condensed with 4-ethyl-7-hydroxy-2H-1-benzopyran-2-one and converted into (+)-4-ethyl-7-[(1'R,2'S,3'S,4'R)-2',3',4'- trihydroxycyclohexyloxy]-2H-1-benzopyran-2-one ((+)-2). Enantiomer (-)-2 was obtained from a (+)-conduritol F derivative. The carbaxyloside (-)-2 with the L-xylose configuration was more active than (+)-2 in the Wessler's model.

Administration, Oral↗
PubMed1998

Ultrastructural, morphometrical and immunocytochemical analyses of the exocrine pancreas in a hibernating dormouse.

Pancreatic acinar cells of euthermic, hibernating and arousing individuals of the hazel dormouse Muscardinus avellanarius (Gliridae) have been observed at the electron-microscopic level and analysed by means of ultrastructural morphometry and immunocytochemistry in order to investigate possible fine structural changes of cellular components during periods of strikingly different degrees of metabolic activity. During hibernation, the cisternae of the rough endoplasmic reticulum (RER) flatten assuming a parallel pattern, the Golgi apparatus is extremely reduced and the mitochondria contain many electron-dense particles. The cell nuclei appear irregularly shaped, with deep indentations containing small zymogen granules. They also contain abundant coiled bodies and unusual constituents, such as amorphous bodies and dense granular bodies. Large numbers of zymogen granules occur in all animals. However, the acinar lumina are open and filled with zymogen only in euthermic animals, whereas, in hibernating and arousing individuals, they appear to be closed. Morphometrical analyses indicate that, in pancreatic acinar cells, nuclei and zymogen granules significantly decrease in size from euthermia to hibernation, probably reflecting a drastic decrease of metabolic activities, mainly protein synthesis and processing. In all the studied animals, immunocytochemistry with specific antibodies has revealed an increasing gradient in alpha-amylase content along the RER-Golgi-zymogen granule pathway, reflecting the protein concentration along the secretory pathway. Moreover, during deep hibernation, significantly larger amounts of alpha-amylase accumulate in RER and zymogen granules in comparison to the other seasonal phases analysed. Upon arousal, all cytoplasmic and nuclear constituents restore their euthermic aspect and all morphometrical and immunocytochemical parameters exhibit the euthermic values, thereby indicating a rapid resumption of metabolic activities.

Amylases↗