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Biomedical subjects

P Slezak

Publications and source records attributed to P Slezak.

63 records · Page 4Linked to original sources
PubMedDate not supplied

Study of the gastric mucosal background in patients with gastric polyps.

The characteristics of gastric mucosal patterns in the polyp-bearing stomach were investigated by the endoscopic Congo red test and systemic four-points biopsy in 46 patients with hyperplastic polyps and 21 patients with gastric adenomas. In addition, function of the stomach in these patients was assessed by determination of gastric acidity and fasting serum gastrin level and by gastrin response test to a beef extract. In the investigation of the gastric mucosal pattern in hyperplastic polyp patients, Type A gastritis (involving the corpus but sparing the antrum) was most frequently found. On the other hand, extensive intestinal metaplasia from the pyloric antrum to the corpus was most often noted in the adenoma-bearing stomach. Hypergastrinemia was more marked in hyperplastic polyp patients, and may be involved in the pathogenesis of hyperplastic polyps. Attention should be paid to the detection of cancer in areas without polyps during endoscopic observation and reexamination of patients. On these occasions, the characteristics of the background mucosa for each type of polyp should be kept in mind.

Adenoma↗
PubMedDate not supplied

Non-polypoid colorectal neoplasias: a multicentric study.

A total of 781 non-polypoid colorectal neoplasias harvested at 4 main Hospitals in Tokyo, Japan (n = 420) and at 4 different time-intervals at the Karolinska Hospital, Stockholm, Sweden (n = 361) were reviewed. By applying strict histologic definitions, the lesions were classified into adenomas with low grade dysplasia (LGD), with high grade dysplasia (HGD), intramucosal carcinomas (IMC) or submucosal carcinomas (SMC). Of the non-polypoid neoplastic lesions reviewed in Sweden, 82.8% (n = 299) had LGD. In Japanese patients only 42.6% (n = 179) had LGD (p < or = 0.001). On the other hand, as many as 42.4% (n = 178) of the non-polypoid lesions in Japanese patients had HGD, but only 14.1% (n = 51) of those in Swedish patients (p < or = 0.001). Whereas 15.0% (n = 63) of the non-polypoid neoplasias seen in Japan were IMC or SMC, only 3.0% (n = 11) of those seen in Sweden were IMC or SMC (p < or = 0.001). The cause(s) for these differences remains unclear. In Japan, however, a marked increased incidence of colonic cancer has been recorded in later years. Whether the "catching up phenomenon" by the Japanese with western colonic cancer incidence includes increased histologic aggressiveness of non-polypoid neoplastic polyps--as found in this survey--remains to be elucidated.

Adenoma↗
PubMedDate not supplied

Imaging-based dynamic liver testing--a computerized simulation.

BACKGROUND/AIMS: The mechanisms for maintaining liver function are complex and currently used liver function tests give limited and often nonspecific and insensitive results. The aim of the study was to demonstrate a dynamic liver test with a tomographic imaging modality as sampling method by means of a computer simulation. METHODOLOGY: A virtual three-dimensional liver model, consisting of parenchyma and bile ducts, was created using computer aided design/computer aided manufacturing software. An intravenously administered, bile excreted test substance was simulated in the model by awarding changing densities to the parenchyma and bile ducts in 12 identical sets of the model. RESULTS: Imaging-based density measurements enabled the creation of time-density curves reflecting the transport of the simulated test substance in the parenchymal mass and bile ducts. By means of quantitative analysis of the curves, parenchymal uptake and excretion and intrahepatic bile flow could be assessed independently. CONCLUSIONS: The method enables comparison of function in different liver segments and may have particular value in investigating diseases that affect the liver in a non-homogeneous fashion, for example primary sclerosing cholangitis. Imaging sampling can theoretically be applied with any tomographic imaging technique for which a suitable test substrate exists, including computed tomography, magnetic resonance imaging or single photon emission tomography.

Bile↗
PubMedDate not supplied

Colorectal carcinoma in ulcerative colitis is decreasing in Scandinavian countries.

A total of 31 cases with Ulcerative Colitis (UC) and colorectal carcinoma were retrieved from the files of the Karolinska Hospital, Stockholm between 1951 and 1998. Sections from 16 colectomy specimens (operable cases) and 15 biopsies obtained at laparotomy (inoperable cases), were available for the study. Of the 31 patients reported here, 22 (71%) were 49 years of age or younger at the time of surgery for carcinoma. In comparison only 47 (5.5 %) of the 855 colorectal carcinomas without UC reported in the Stockholm area in 1990 were 49years of age oryounger. When this hospital was a referral Center (1951 through 1969) 18 cases of carcinoma in UC were operated between 1951 and 1960 (1.8 patients/year), but only 4 between 1961 and 1969 (0.44 patients/year). During the surveillance period of 29 years (1970 to March 1998) only 9 patients (0.31 cases/year) were found to have carcinoma complicating UC. Notably, 8 of the 9 patients were operated on between 1970 and December 1989 (0.42 patients/year), but only one case between January 1990 and March 1998 (0.11 patients/year). The data presented indicate that the frequency of carcinoma cases in pancolitics has decreased at this hospital, not only during the referral period, from 1.8 patients/year during the 50's to 0.40 patients/year during the 60's, but also during the surveillance period (from 0.44 patients/year/during the 70's and 80's to 0.11 patients/year between 1990 and March 1998). This, despite the incidence of UC in the Stockholm County remained stable for the past 40 years (4.2 to 5 patients/10(5) inhabitants) and that the population in the Stockholm County has steady increased since 1950. A review of the present literature indicated that the ris for colorectal carcinoma in pancolitics is presently decreasing, not only in Sweden but also in other Scandinavian countries.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

The subepithelial band in collagenous colitis is autofluorescent a study in H&E stained sections.

The normal basement membrane (BM) of the colon and the collagenous colitis band (CCB) seen in H&E-stained sections were recently found to be autofluorescent. Measurements of the thickness of the BM and of the CCB were taken using transmitted-light (TL) and incident-light fluorescence (IFL). The mean thickness of the BM in control cases was 3.2 microns with TL and 3.4 microns with IFL. The mean thickness of the CCB was 50.3 microns with TL and 55.8 microns with IFL. In 10 consecutive cases of CC, the thickness of the CCB was repeatedly measured in the same area, on different occasions. Substantial variations in the vertical size of the CCB were recorded in the same area when using TL but not with IFL. Good demarcation of the CCB with ILF and poor demarcation of the deep border of the hyaline band, because of overlapping inflammatory cells, were the apparent causes. Autofluorescence was induced by the eosin stain. The results suggest that the simple observation of H&E--stained biopsies with ILF may be sufficient to diagnose CC. Re-sectioning for special staining can be avoided, thus reducing final diagnosis-time and laboratory costs.

Animals↗
PubMedDate not supplied

Differences in the distribution of acidic mucins between flat tubular adenomas and flat serrated adenomas of the colorectal mucosa.

Two consecutive sections from 72 endoscopically detected flat colorectal polyps (flat tubular adenomas n = 40, flat serrated adenomas n = 18, flat hyperplastic polyps n = 7 and normal colonic mucosa n = 7) were stained with Alcian blue pH 2.5 (AB) or with high iron diamine (HID) without counterstain, to evidence the most important attribute of the colorectal cells i.e. their capacity to produce acidic mucins (sialomucins and sulphomucins respectively). Intense AB and HID staining (++) was found in the upper part of the crypts of all (100%) sections with normal colonic mucosa or with flat hyperplastic polyps, in 13 of the 18 (72%) flat serrated adenomas (with low grade dysplasia = LGD, n = 16; or high grade dysplasia = HGD, n = 2) but in none (0%) of the 40 tubular adenomas. Slight (+) or negative staining of the upper part of the crypts were recorded in all 40 (100%) flat tubular adenomas (LGD n = 32; HGD, n = 8), but in only 5 of the 18 (27,7%) flat serrated adenomas (LGD n = 3; HGD n = 2) and in none (0%) of the sections with normal colonic mucosa or with flat hyperplastic polyps. Intense AB and HID staining (++) was found in the lower part of the crypts in all sections (100%) with normal mucosa or with flat hyperplastic polyps, in 36 of the 40 flat (90%) tubular adenomas (LGD n = 32; HGD n = 8), but in none (0%) of the flat serrated adenomas. Slight (+) or negative stainings in the lower part of the crypts were recorded in all 18 (100%) flat serrated adenomas, but in only 4 of the 40 (10%) flat tubular adenomas and in none of the sections (0%) with normal mucosa or with flat hyperplastic polyps. Thus, the mucosal localization of the depletion of mucin production differs in flat serrated adenomas and in flat tubular adenomas. The difference in topographic distribution of the depletion of acidic mucins in epithelial cells is a new argument in favour of the identity of flat serrated adenomas as an independent neoplastic phenotype in the colorectal mucosa.

Adenoma↗
PubMedDate not supplied

Quantitative endoscopic classification of esophagitis by means of computerized image processing. Part II: Experimental study.

Digital processing of video-endoscopic images in esophagitis appears to be a useful method for quantifying mucosal color changes, with a potential to provide improved reproducibility in the follow up of individual cases and in comparison between patients and groups of patients. However, the sources of error such as type of equipment, the distance of the endoscope tip to the cardia, axial positioning of the endoscope in the esophagus, and the distance from the endoscope tip to the area of interest must be taken into account.

Endoscopy, Digestive System↗
PubMedDate not supplied

Ethnic or environmental differences in disparate geographic regions may influence the histology of flat colorectal neoplasias.

Histologic sections of endoscopically flat colorectal polyps removed in Tokyo and Stockholm were reviewed. A total of 178 flat colorectal neoplasias (88 from the Tokyo Medical College Hospital, Tokyo and 90 from the Karolinska Hospital, Stockholm) were classified following strict histologic criteria by two different pathologists (one Swedish and the other Japanese). The number of polyps with high grade dysplasia, with intramucosal carcinoma and with invasive carcinoma were significantly higher (p < 0.001) in Tokyo (61.4% or 54/88) than in Stockholm (15.0% or 14/90). The present results suggest that flat colorectal neoplasic polyps may be histologically more "severe" and more "aggressive" in Japanese than in Swedish patients. The possibility that more "advanced" lesions had been inadvertently removed in Tokyo was discounted as Japanese endoscopists were also instrumental in excising many of the flat colorectal polyps in Stockholm. Ethnic and/or environmental differences seem to play a crucial role in the evolution of flat colorectal neoplasic polyps from LGD and HGD, to intramucosal and to invasive carcinoma.

Adult↗