PubMed Health⌕ Search

Biomedical subjects

A Bosma

Publications and source records attributed to A Bosma.

At least 55 records · Page 3Linked to original sources
PubMed1992

Colorectal villous adenoma: transrectal US in screening for invasive malignancy.

Exclusion of focal infiltrating malignancy in colorectal villous adenoma is a prerequisite when nonsurgical treatment is considered. In a study of 81 patients with endoscopically identified colorectal villous adenoma screened for malignancy with transrectal ultrasonography (US), 15 patients were excluded because of incomplete follow-up. Twelve carcinomas were present, confirmed with either histopathologic examination after surgical resection (n = 9) or biopsies during laser treatment (n = 3). Nine of them were detected with transrectal US on the basis of disruption of the anatomic wall layers (sensitivity, 75%). In 46 of the 54 adenomas transrectal US helped confirm the benign nature of the lesion (specificity, 85%). Seven of the eight false-positive cases happened to be previously treated with surgery or coagulation. Treatment-associated inflammatory changes in the wall layers seemed responsible for this misinterpretation. Because of the high predictive value for a negative result (benign adenoma, 94%), transrectal US is recommended for the evaluation of villous adenomas to detect malignancy, especially when nonsurgical treatment is considered. Transrectal US should be performed before diagnostic polypectomy.

Adenoma↗
PubMed1992

Benign fibrosing disease at the hepatic confluence mimicking Klatskin tumors.

BACKGROUND: Hilar obstructions remain a challenge with regard to diagnosis and treatment. METHODS: In the period from 1984 to 1990, 82 patients underwent resective surgery under the presumptive diagnosis of hilar cholangiocarcinoma (Klatskin tumor). The diagnosis was based on the combined appearances on direct cholangiography and ultrasonography in all cases, with the use of various other imaging modalities in some cases. RESULTS: The perioperative findings from an experienced surgical team were usually thought to be compatible with bile duct carcinoma. However, histologic examination of the resected specimens revealed benign fibrosing or localized sclerosing lesions in 11 patients (13.4%). CONCLUSIONS: The current state of diagnostic imaging fails as yet to discriminate reliably between benign and malignant hilar lesions. Whereas the immediate therapeutic consequences may be equal (resection followed by hepaticojejunostomy), the late consequences differ in a major way because benign disease has a much better prognosis. In the presence of suspicious hilar obstruction, operable lesions should not be treated by "palliative" intubational techniques and radiation therapy without a firm diagnosis of malignancy. However, overtreatment (extended liver resection, vascular reconstruction, and liver transplantation) should be avoided as well when a benign lesion has not been ruled out.

Adenoma, Bile Duct↗
PubMed1992

Reappearance of vanished bile ducts.

A 36-year-old Surinam woman with a severe form of toxic epidermal necrolysis of unknown origin is presented. Skin lesions healed gradually without scarring within 3 to 4 weeks, but eye lesions progressed to symblepharon and corneal opacification, resulting in almost complete blindness. In addition, toxic epidermal necrolysis was associated with severe intrahepatic cholestasis caused by vanished bile duct syndrome; viral hepatitis, primary biliary cirrhosis and primary sclerosing cholangitis were excluded. After about six months, intrahepatic chole-stasis improved spontaneously and a third liver biopsy taken after 51 weeks of illness revealed that the bile ducts had reappeared. At present, the patient is relatively well, with no jaundice, although parameters of cholestasis are still elevated: Alkaline phosphatase three times, and gamma GT thirty times the normal values. This sequence of events has to our knowledge never been reported in the literature.

Adult↗
PubMed1992

[The value of noninvasive 24-hour blood pressure measurement in patients with renoparenchymal, renovascular or severe essential hypertension].

210 patients receiving antihypertensive treatment underwent non-invasive ambulatory blood-pressure monitoring for the first time. 44 suffered from chronic renal failure, 51 had been renal transplanted, 36 had chronic glomerulonephritis, 36 had renovascular hypertension, and 43 had essential hypertension with severe end-organ damage. We analyzed the Circadian rhythm and the rate of insufficient antihypertensive treatment. While mean daytime systolic and diastolic blood pressure were not different between groups, patients with chronic renal failure, renal transplant or glomerulonephritis showed a very high rate (95-72%) of absent nighttime blood-pressure reduction. In patients with renovascular hypertension or complicated essential hypertension there was a lower rate (69-40%) of absent nighttime blood pressure reduction. The ambulatory blood-pressure monitoring led to a modification of antihypertensive treatment in 78% of patients because of nighttime hypertension. We think that ambulatory blood-pressure monitoring is an essential tool for physicians treating patients with renal disease or complicated essential hypertension.

Antihypertensive Agents↗
PubMed1992

Morphologic changes of extrahepatic bile ducts during obstruction and subsequent decompression by endoprosthesis.

The morphologic changes of the extrahepatic biliary tract during obstruction and the effects of biliary decompression by means of an endoprosthesis on the bile duct wall were studied by light microscopy and scanning electron microscopy. Common hepatic duct biopsy specimens and bile cultures were obtained during surgery from 30 patients with a distal common bile duct obstruction caused by a tumor. Thirteen patients had obstructed bile ducts of 3 weeks' duration (group A). Seventeen patients had had jaundice for a period of 4 weeks and had subsequently undergone preoperative endoscopic biliary stenting for a period of 4 weeks (group B). Three autopsy specimens from patients without hepatobiliary disease served as controls. The results showed that the initial dilatation and thickening of the obstructed ducts in group A were associated with a mild inflammation, a moderate degree of fibrosis, and local epithelial disintegration. The presence of an endoprosthesis, however (group B), induced severe inflammatory changes with considerable fibrosis and ulcerative lesions, resulting in markedly thickened ducts with lumina approximating the diameter of the stent. Three of 13 (24%) bile cultures in group A were positive and 14 of 17 (82%) in group B were positive.

Bile Duct Neoplasms↗
PubMed1991

Effect of percutaneous interstitial thermal laser on normal liver of pigs: sonographic and histopathological correlations.

Tumour necrosis can be induced by interstitial application of low power laser light, which causes thermal damage to the tissue. In normal pig liver the effects were studied of low power Nd:YAG laser light (continuous wave; 1.5 W, 10 min, wavelength 1064 nm), administered percutaneously via a 600 micron fibre. Ultrasound images were compared with histopathological findings. Histopathology showed induction of sharply demarcated lesions with a mean diameter of 10-15 mm (days 0 and 7), consisting of coagulative necrosis. Healing of the lesion occurred by granulation, fibrosis and removal of cell debris. Lesions could not be seen by week 4, which suggests complete regeneration. Ultrasonography showed a good correlation with histopathology, especially at 1 week when different histopathological tissue layers could be discriminated by ultrasonography. It is concluded that thermal lesions in liver can be induced via a percutaneous route and that ultrasound imaging is useful in monitoring the lesions during and after the procedure.

Animals↗
PubMed1991

Chronic administration of ethanol with high vitamin A supplementation in a liquid diet to rats does not cause liver fibrosis. 1. Morphological observations.

Rats of two strains (BN/BiRij and WAG/Rij) were fed the ethanol-containing Lieber-De Carli liquid diet supplemented with high amounts of vitamin A for 16 months. In contrast to Lieber and co-workers, who showed liver fibrosis developing within 9 months on the same diet in Sprague-Dawley rats, we were unable to demonstrate a histological and biochemical increase in liver collagen in either strain. Steatosis was present to a varying degree in both strains in ethanol-treated rats, but also in control animals. Considerable liver inflammation with focal necrosis accompanied by severe systemic inflammation was observed in 60% of the ethanol-treated WAG rats. This suggests that, at least in rats, the main effects of chronic ethanol consumption on the liver may be secondary to interference with host resistance to infections. The ethanol-high vitamin A Lieber-De Carli liquid diet does not necessarily elicit fibrosis or other characteristic histological abnormalities of human alcoholic liver disease.

Animals↗
PubMed1991

Chronic administration of ethanol with high vitamin A supplementation in a liquid diet to rats does not cause liver fibrosis. 2. Biochemical observations.

The inability of the 'ethanol/high vitamin A Lieber-DeCarli diet' to induce liver fibrosis in two different rat strains was further evaluated by determining changes in parameters of liver cell damage and of retinoid and lipid metabolism. In the ethanol/vitamin A-treated group, slight but constant hepatic cell damage, as indicated by elevated alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase activities in blood, was already observed at 6 months and maintained until the time of death at 16 months. Serum gamma-glutamyl transaminase activities were not raised. Moderate parenchymal liver cell damage was not accompanied by fibrosis. Hypertriglyceridemia or hypercholesterolemia were observed at 6-16 months of chronic alcohol administration. This response was strain dependent. In ethanol-treated rats of both strains, total liver retinoids and serum retinol concentrations were not altered. Therefore, the hypothesis that interaction between alcohol and retinoids is a major factor in the pathogenesis of alcoholic liver disease, needs to be reconsidered.

Animals↗
PubMed1990

Clinical significance of implantation metastases after surgical treatment of cholangiocarcinoma.

Cytologic examination of bile obtained during surgery from intrahepatic bile ducts in patients with malignant proximal bile duct obstruction has shown a high incidence of tumor cells. Spill of bile occurs frequently during these operations and postoperative bile leakage often occurs. Typical implantation metastases were detected in three patients who underwent resective surgery for bile duct cancer. In addition, peritoneal spread of bile duct carcinoma was found on postmortem examination in seven of ten patients who died 6 to 27 months after resection of the hilar tumor. A relation between tumor-positive bile cytologic findings, tumor spill, and seeding during surgery is likely to exist. It is recommended that during surgery the utmost care should be taken to prevent spill of bile.

Adenoma, Bile Duct↗
PubMed1990

Early adenoid cystic carcinoma of the upper oesophagus.

A 70-year-old male patient with an early stage primary adenoid cystic carcinoma of the oesophagus is reported. The 1.5 cm protuberant tumour, located in the upper oesophagus and found during examination for heartburn, was radically resected. It was restricted to the submucosa, which strongly suggests that it originated from the oesophageal glands. Microscopically, the tumour showed sparse S100 cells. This finding is in contrast with that in adenoid cystic carcinomas of the salivary glands.

Aged↗
PubMed1988

Synergism between ethanol and carbon tetrachloride in the generation of liver fibrosis.

In this study, alcohol-induced histological lesions in a short-term experimental rat model were compared with those characteristic of human alcoholic liver disease. In the rat model used, pretreatment with carbon tetrachloride (CCl4) for 6 weeks was employed possibly to sensitize the liver for the effects of alcohol and shorten the time of induction of alcoholic liver disease. After 6 weeks of CCl4 treatment, subsequent maintenance on drinking water containing up to 10 per cent alcohol for 7 weeks potentiated liver fibroplasia as compared with non-alcohol-treated rats. However, steatosis and alcoholic hepatitis, as histological evidence for alcoholic liver disease as seen in humans, were not observed. In non-CCl4-pretreated control animals, alcohol administration had no effect on liver histology. It can be concluded that in the model used, CCl4 pretreatment sensitizes the liver to increase collagen deposition following alcohol administration, but not to steatosis or alcoholic hepatitis as seen in human alcoholic liver disease. In this experimental set-up, direct metabolic interaction of CCl4 with alcohol as a cause of the increased fibroplasia can be excluded.

Animals↗
PubMed1988

Immunohistochemical localization of pepsinogen A and C containing cells in Barrett's oesophagus.

No data are available on the localization of Pepsinogen A (PGA = PG I) and Pepsinogen C (PGC = PG II) positive cells in Barrett's epithelium. Endoscopic biopsy specimens were taken from the columnar epithelium from 23 patients (n = 93), and in addition from the cardia from eight healthy control subjects (n = 38). The tissue was stained by the immunoperoxidase technique with specific anti-pepsinogen antisera, and double immunostained for PGA and PGC. In the Barrett's epithelium PGA was found in 28 out of 93 biopsy specimens (30.1%) and PGC in 55 out of 93 (59.1%). Chief cells always stained both for PGA- and PGC +. PGA + and PGC + cells were found each in 100% of the biopsy specimens with fundic type epithelium, in 21.7% and 70.7% of biopsy specimens with junctional type, in 0% and 26.1% of biopsy specimens with specialized epithelium and in 12.5% and 43.5% of biopsy specimens with mixed junctional/specialized features respectively. Dysplastic epithelium stained always negatively with both anti-pepsinogen antisera. In most control cardia biopsy specimens PGA as well as PGC were demonstrable; occasionally clear mucous glands were PGA - and PGC+. It is concluded that pepsinogen-containing cells can be accurately identified in the Barrett's epithelium; their presence seems related to the histological cell type. Identification of pepsinogen positive cells may contribute to a more accurate morphological classification of the Barrett's epithelium.

Adolescent↗