Biomedical subjects

H Bühler

Publications and source records attributed to H Bühler.

At least 19 recordsLinked to original sources

PubMed1992

[Primary amyloidosis of the liver].

For 2 years a 72-year-old man had suffered from nonspecific upper abdominal discomfort and hepatomegaly. The gamma-glutamate transaminase concentration was increased to 121 U/l, the erythrocyte sedimentation rate was 80 mm in the first hour. Histological examination of tissue from the enlarged liver (22 cm in the midclavicular line) revealed the diagnosis of amyloidosis. The gastric mucosa, duodenum and rectum were not involved. Two years later ascites developed; six months after this he was again hospitalized in hepatic coma. Now, for the first time, a type IgA-lambda paraprotein was demonstrated by serum immunoelectrophoresis. The patient died of slowly progressing anicteric liver failure after having been ill for a total of 4 1/2 years. At autopsy there were extensive amyloid deposits throughout the liver and spleen so that the structure of these organs was hardly recognizable. The amyloid deposits in the liver were restricted to the glomerular region, while there was no amyloid in the heart. Histochemical tests showed that the deposits were strongly positive to the anti-lambda antibody. This was thus a case of primary (AL-lambda) amyloidosis of the liver and spleen which had taken an unusually prolonged course, because the heart was not involved at all and the kidneys only slightly.

Aged↗

PubMed1992

[Heterosexual transmission of hepatitis-C virus].

Parenteral transmission of hepatitis C virus (HCV) through blood transfusions and intravenous drug misuse is well established. Since 50% of patients with hepatitis C have no history of parenteral exposure, other ways of transmission must exist. The purpose of this study was to examine the epidemiological importance of heterosexual intercourse for transmission of HCV infection. 29 heterosexual contacts (13 men, 16 women, mean age 47 years) of 29 index patients (16 men, 13 women, mean age 49 years) with histologically und serologically documented chronic hepatitis C were questioned about parenteral exposure and sexual behaviour. Their serum samples were examined for ALT activity and anti-HCV antibodies (first-generation Ortho-HCV-ELISA). Five contacts were using condoms to prevent infection. Five of 24 contacts (21%) practising unprotected sexual intercourse, but none of 5 contacts using condoms, showed evidence of heterosexual HCV transmission: 4 were anti-HCV positive (one with elevated ALT activity) and another showed elevated ALT activity with a negative anti-HCV test. None of these contacts had a history of parenteral exposure. Our results indicate that heterosexual transmission of HCV is epidemiologically important. The true rate of infection may be even higher, for two reasons: (1) not every HCV infection is detected by the anti-HCV test, and (2) the anti-HCV test may turn negative again in uncomplicated infection.

Adult↗

PubMed1992

[Second generation hepatitis-C virus test and polymerase chain reaction in anti-C 100 negative patients with chronic non-A, non-B hepatitis].

The aim of our study was to evaluate whether a negative HCV test of the first generation (HCV-ELISA 1) using the antigen C100-3 excludes chronic HCV infection, or whether patients exist who are negative for antibodies to C100-3 in spite of chronic hepatitis C. 27 patients with histologically proven chronic non-A, non-B hepatitis, all of whom were HCV-ELISA 1 negative, were tested by the HCV test systems of the second generation (Ortho-HCV-ELISA 2 and Chiron-HCV-RIBA 2) based on the distinct HCV antigens 5-1-1, C100-3, C33c and C22-3. To determine the presence of viremia, serum samples were also tested for HCV-RNA with "nested" PCR. 10 of 27 patients proved to be persistently negative when tested with the second generation assays. One patient showed low grade reactivity by HCV-ELISA 2, but non-reactivity by HCV-RIBA 2. In none of these 11 patients was HCV-RNA detected. 16 (60%) of 27 patients negative with HCV-ELISA 1 were positive with HCV-ELISA 2. HCV-RIBA 2 detected antibodies to the structural core antigen C22-3 in all of these 16 patients and antibodies to the non-structural antigen C33c in 14 of them, while antibodies to 5-1-1 or C100-3 were not found in any of these cases. 10 (63%) of the 16 HCV-ELISA 1 negative, but HCV-ELISA 2 and HCV-RIBA 2 positive patients were positive for HCV-RNA by "nested" PCR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Hepatitis-C virus and hepatoma].

To clarify the relationship between hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC), frozen serum samples from 213 patients with histologically proven liver cirrhosis alone (96 alcoholics, 59 HBsAg positive, 29 non-A, non-B hepatitis, 29 cryptogenic) and 40 patients with liver cirrhosis and HCC (12 alcoholics, 7 HBsAg positive, 7 non-A, non-B hepatitis, 14 cryptogenic) were analyzed for antibodies to hepatitis C virus (anti-HCV) with the ortho-HCV-ELISA. The results were as follows. 50 of 253 (20%) patients were anti-HCV positive. The prevalence of anti-HCV was significantly higher in patients with HCC than in patients without HCC (14 of 40 [35%] vs 36 of 213 [17%]; p less than 0.001). In anti-HCV-positive patients HCC were significantly more frequent than in anti-HCV-negative patients (14 of 50 [28%] vs 26 of 203 [13%]; p less than 0.001). The significantly higher occurrence of HCC in anti-HCV-positive patients was not related to other known risk factors such as alcoholism or chronic hepatitis B virus (HBV) infection. Patients with HCV infection as the only risk factor also had a significantly higher occurrence of HCC (12 of 38 [32%] vs 26 of 203 [13%]; p less than 0.001). Our data suggest that chronic HCV infection plays an important role in the pathogenesis of HCC, in particular in patients with cirrhosis unrelated to alcohol or HBV infection.

Aged↗

PubMed1992

[Anti-HCV test in patients with chronic non-A, non-B hepatitis].

Our study was designed to evaluate the clinical significance of the ELISA-anti-HCV test. 90 patients with histologically proven chronic non-A, non-B hepatitis (NANBH) and a control group consisting of 36 patients with primary biliary cirrhosis (PBC) were analyzed for antibodies to hepatitis C virus (anti-HCV). Frozen serum samples were tested with the ortho-HCV-ELISA. 67 of 90 (74%) patients with chronic NANBH showed antibodies to the hepatitis C virus. The prevalence of anti-HCV in patients with parenterally transmitted and sporadic chronic NANBH was 70% (23 of 33) and 77% (44 of 57) and in patients with chronic active and chronic persistent NANBH 73% (27 of 37) and 76% (40 of 53) respectively. No significant difference in the prevalence of anti-HCV in the 4 subgroups of patients with chronic NANBH was found. 2 of 36 patients (6%) with PBC were anti-HCV positive without evidence of previous HCV infection. Our results bear out the experience of other authors, that HCV is the commonest pathogen of chronic NANBH. The low prevalence of anti-HCV in patients with PBC suggests good specificity. There have been reports in the literature of "false positive results", particularly in autoimmune hepatitis, and it has been shown that borderline positive test results are often unspecific and therefore to be interpreted with care.

Adult↗

PubMed1992

[The endoscopic treatment of malignant biliary tract stenoses with endoprostheses].

In 65 patients (36 men, 29 women; mean age 74 [43-90] years) obstructive jaundice caused by malignant biliary stenosis was treated by endoscopic retrograde insertion of a 10 or 12 F synthetic endoprosthesis. The rate of complications of the endoscopic intervention was 5% (n = 3), 30-day mortality rate was 11% (n = 7) and method-related mortality was 8% (n = 5). Good drainage was achieved in 39 of 41 patients (95%) with the 12 F endoprosthesis, and in 15 of 21 patients with a 10 F one (71%) (P less than 0.001). Renewed jaundice due to prosthesis occlusion occurred in 31 patients an average of 103 (11-350) days after placement. Interval until occlusion correlated with the site of the stenosis and the length of the endoprosthesis. Jaundice recurred earlier in patients with long prostheses and proximal biliary stenosis than in those with a short prosthesis and distal stenosis. In 20 patients with renewed jaundice the endoprosthesis was replaced endoscopically. At that time 13 of the patients had a cholangitis. Occlusion of the new endoprosthesis was more common in patients with cholangitis (9 of 13) than those without (2 of 7; P less than 0.05). These findings indicate that endoscopic biliary tract drainage should be performed with as short a 12 F endoprosthesis as possible. In view of the potential need for early change of endoprosthesis the biochemical parameters of cholestasis should be regularly monitored.

Adult↗

PubMed1992

Polymerase chain reaction detects hepatitis B virus DNA in paraffin-embedded liver tissue from patients sero- and histo-negative for active hepatitis B.

The polymerase chain reaction (PCR) was used to analyse tissues from paraffin blocks of liver needle biopsies retrospectively. Biopsies of 29 patients with proven HBsAg and HBcAg expression in liver tissue and of 8 healthy volunteers served as positive (group 1) and negative tissue controls (group 2), respectively. These were compared with 16 patients with proven HBsAg expression in liver but lack of HBcAg (group 3), with 23 patients with anti-HBc as the only hepatitis B virus (HBV)-related marker (group 4) and with 21 patients with liver disease and without HBV markers in tissue or serum (group 5). PCR detected HBV sequences in all cases of the positive control group and in 94% of group 3, in 65% of group 4, and in 71.4% of group 5, whereas all healthy volunteers were negative. Our data show that PCR is able to detect HBV-DNA sequences in virtually all patients with active viral antigen expression but also in a high proportion of hepatitic patients who are silent for active HB but may or may not show signs of a contact with the HBV. Thus, PCR for HBV-DNA in paraffin sections might become a useful tool for identifying patients carrying HBV-DNA but not expressing HBV antigens.

Base Sequence↗

PubMed1991

Inhibition of rat renal 11 beta-hydroxysteroid dehydrogenase by steroidal compounds and triterpenoids; structure/function relationship.

Various compounds with steroidal structure were tested for inhibitory effects on enzymatic activity of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) from rat renal microsomes. Most substances exerting inhibitory potency on both the oxidative as well as the reductive activity can be classified into two main groups: pentacyclic triterpenoids of the oleane type and steroidal detergents of the CHAPS-series. Inhibition is competitive, as was shown for one compound of each group. The IC50 values of the various inhibitors range over five orders of magnitude. In all cases, oxidative activity was inhibited more effectively than reductive activity. An attempt has been made to correlate structural properties and inhibitory potency. In brief, inhibition seems to be enhanced by a C11-oxygen function, which is present in all endogenous glucocorticosteroids and a C7-OH function. Inhibition is reduced by a large and polar substituent at C3 in the A-ring. A large D-ring substituent, such as a bisgluconamidopropyl side chain or even an additional E-ring, does not prevent binding to the enzyme, although inhibition seems to be influenced by its steric conformation. The cardiac glycosides and steroidal antibiotics tested exert no inhibitory effect on 11 beta-HSD. Cholesterol and pentacyclic triterpenoids of the lupane type exhibit a very poor inhibition, probably caused by the localization of planar structures in the ring systems, which differs from that of the effective oleane type inhibitors.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed1991

[Non-A, Non-B hepatitis: advances in diagnosis and therapy].

The characterization of the hepatitis C virus (HCV) and the development of an anti-HCV antibody test have closed a further gap in the etiological diagnosis of viral hepatitis, but at the same time new questions have been raised. It has been shown that HCV is by far the most frequent source of the parenterally transmitted form of non-A, non-B hepatitis (NANBH). The anti-HCV test is reactive in the majority of cases with chronic NANBH. However, seroconversion is delayed by weeks or even months and therefore the test is inappropriate for confirmation of acute NANBH. Most patients with autoimmune hepatitis and some with alcoholic liver injury were shown to be anti-HCV reactive, giving rise to a debate on the specificity of the anti-HCV test. The significance of these findings has not yet been explained, since a confirmation test is currently lacking. Alpha-interferon has been shown to be the first promising drug for treatment of chronic viral hepatitis. In a high percentage of patients with chronic NANBH, treatment with interferon induces biochemical and histological remission. Nevertheless, about half of the patients had relapses under the treatment regimens currently used. The aim of ongoing studies is to improve results by optimizing the dosage and duration of interferon treatment.

Blood Donors↗

PubMed1991

[Hepatitis C antibodies in acute Non-A, Non-B hepatitis].

Stored serum samples of 20 patients with clinically and bioptically proven non-A, non-B hepatitis (NANBH) in the acute stage were tested for the presence of antibodies to hepatitis C virus (anti-HCV) by means of the Ortho ELISA system. After a mean period of 8 weeks from onset of the disease, 8 of 20 patients (40%) had anti-HCV. Our follow-up study included 14 patients. Of 9 primarily anti-HCV-negative patients, 2 became positive after 2 and 7 months respectively, whereas 7 patients remained anti-HCV-negative up to 52 months (range 1-128) after the onset of hepatitis. The prevalence of anti-HCV was 71% in 7 patients with parenteral hepatitis related to transfusions (n = 2) or drug abuse (n = 5), and 38% in 13 patients with sporadic NANBH. Of the 8 anti-HCV-negative patients with sporadic NANBH, 5 had stayed in one of the countries where enterically transmitted NANBH is endemic 3 to 6 weeks before the onset of their disease. Our results show that at present the anti-HCV-test supplies an etiologic basis for approximately half of all cases of NANBH in acute stage. Nevertheless, in most cases the acute NANBH remains a diagnosis of exclusion.

Adolescent↗

PubMed1991

Limited proteolysis of lactate dehydrogenase from porcine heart with trypsin: characterization and reactivation of the fragments.

The ternary complex formed by native lactate dehydrogenase (LDH) from porcine heart, NAD+ and sulfite, was digested with trypsin over a period of 12-16 h3. After removal of the ligands and residual native lactate dehydrogenase by ion exchange chromatography dimers were obtained which were almost inactive. The dimers were lacking a hexapeptide at the N-terminus; however, the secondary structure was the same as that of native lactate dehydrogenase. The circular dichroism spectra showed a dependence on temperature which suggested an equilibrium of two different structural states. The reaction of antibodies against native porcine heart LDH with the dimers restored the catalytic activity, and subsequently the dimers behaved similarly to the native enzyme. Addition of 1 M phosphate or NAD-sulfite to the dimers restored 80-90% of the catalytic activity. It could be demonstrated that the behavior of the reactivated dimers, in contrast to that of the inactive dimers, was similar to the behavior of native lactate dehydrogenase. For instance, ultracentrifugal analysis showed that dimers reactivated with NAD-SO3- were associated to give tetramers. The reaction of antibodies against native LDH with the dimers reactivated with NAD-SO3- demonstrated that the native LDH and the dimers have the same surface determinants.

Amino Acid Sequence↗

PubMed1991

Bile acids and their amidates inhibit 11 beta-hydroxysteroid dehydrogenase obtained from rat kidney.

Recently it has been demonstrated that interaction of corticosteroids with extraadrenal target cells can effectively be modulated by metabolic transformation of the steroid hormone. As far as 11-hydroxylated glucocorticoids are concerned 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) is the most important enzyme charged with target cell metabolism. Inhibition of 11 beta-HSD function either by genetically transmitted deficiency or by exogenous enzyme inhibitors causes severe pathophysiological derangements, which result in a syndrome of "apparent mineralocorticoid excess". In the present paper we have tested whether or not endogenous inhibitors of this enzyme system might exist. The effects of the main naturally occurring mono-, di-, and trihydroxylated bile acids in man on 11 beta-HSD have been studied in in vitro experiments. Using rat renal microsomes it could be demonstrated that unconjugated bile acids of all three classes as well as the corresponding glycine and taurine amidates effectively inhibit oxidative as well as reductive activity of 11 beta-HSD, with lithocholic acid and chenodeoxycholic acid being the most potent compounds. It is concluded that bile acids are potent endogenous inhibitors of 11 beta-HSD and, therefore, could participate in abnormalities of cortisol metabolism observed in liver cirrhosis and extrahepatic biliary obstruction and, possibly, after ingestion of bile acids.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed1991

[Surgical treatment methods in furcation involvement and their long-term prognosis].

Multi-rooted teeth showing severe furcation defects can be treated by either of the following techniques: Tunnel preparation, hemisection and root resection. The aim of these approaches is to reestablish the anatomical features making it possible to carry out proper homecare in the future. In hemisection and root resection this is achieved by separating and/or removal of roots. An assessment of prognosis is made on the basic of long-term follow-ups. After ten years an average bone loss of 9.5% was recorded. When bridgework was correctly designed loading did not have a detrimental influence on further bone loss. Roots restored by using gold dowels showed the same technical durability as roots restored with root screws/composite cores. The total failure rate after ten years varied between 32 and 38%. Nonperiodontal failures were predominating. This leads to the conclusion that prognosis may not be judged on the basis of periodontal aspects alone.

Alveolar Bone Loss↗

PubMed1991

[Colonic polyps: clinical and practical implications].

Among colorectal polyps, various forms of neoplastic or non-neoplastic lesions are distinguished by histology. Most accumulated knowledge suggests that the majority of cancer of the colon arise in pre-existing benign neoplastic polyps (adenoma-carcinoma sequence). Because of the risk of cancer being already present, all adenomatous polyps must be removed in toto. The carcinoma may occupy only a small area of the polyp, and therefore, forceps biopsies are inappropriate due to the sampling error. Since patients with polyps detected by rectosigmoidoscopy often have further polyps in the remaining part of the colon, complete examination of the whole colon is required. Follow-up examinations are indicated, because the risk of developing new polyps is high. Studies of the life history of the adenoma-carcinoma sequence suggest that interval of complete large-bowel follow-up may be about 5 years. The policy of polypectomy and follow-up examinations should be possible to prevent the development of colorectal cancer.

Cell Transformation, Neoplastic↗

PubMed1990

[Coronal repositioning of root fragment by root elongation with a titanium endodontic implant].

Teeth with deep transverse or oblique root fractures can nowadays be preserved by intra-alveolar transplantation. This method, however, has its limitation: The apical root fragment must not be too short in proportion to the crown length. This report describes a method to retain even very short roots. 14 roots have been carefully extracted. Then, the following treatment has been performed extraorally: Apectomy, lengthening of the root with a common titanium root screw and replantation of the root in an extruded position which allowed to carry out correct root filling and crown reconstruction. After an average observation period of 19 months 11 cases out of 14, i.e. 79%, were successful according to the criteria stated by Kristersson and Kvint. If the long-term results turn out as promising as the short-term findings, the concept might well be extended to other indications. One example is to stimulate the growth of a genuine periodontal "re-attachment" in intrabony pockets by extruding viable periodontal membrane areas to a more coronal level.

Adult↗

PubMed1990

[Ultrasonically-guided sclerosing of kidney and liver cysts using polidocanol].

First experiences are reported with percutaneous sclerosing therapy of cysts with polidocanol (aethoxysklerol 1%) using ultrasound for needle guidance. They cover two patients with symptomatic cysts of the liver and a patient with polyglobulinemia and an erythropoietin-producing renal cyst. These experiences are compared to previously reported ones.

Adult↗

PubMed1990

[Endoscopic treatment of bile duct stones and their complications].

Endoscopic treatment of bile duct stones has reached a high degree of perfection by the introduction of adjuvant therapies raising the rate of success while at the same time reducing risk. Large stones are fragmented mechanically or by means of extracorporal shock wave lithotripsy thus permitting to avoid a long and risky papillotomy. Drainage of the bile is assured with a nasobiliary drain in case of primary failure reducing the risk for cholangitis. Endoscopic treatment is the choice for residual or recurring stones after cholecystectomy and for severe purulent cholangitis in which surgical treatment is still charged with a high mortality. Endoscopic stone removal is further indicated when an operation per se carries a high risk. Long-term studies have demonstrated that even patients in which the gall bladder is preserved stay free of recurrence. In patients with severe biliary pancreatitis early papillotomy reduces complication-rate and mortality. The question remains unsettled whether patients at normal risk with simultaneous cholecysto- and choledocholithiasis should undergo direct cholecystectomy and bile duct revision or if they could profit from endoscopic removal of stones prior to cholecystectomy.

Ampulla of Vater↗

PubMed1990

[Measurement of intestinal permeability in Crohn's disease, ulcerative colitis, sprue and idiopathic hyperamylasemia using polyethyleneglycol-400].

We investigated intestinal permeability in healthy adult volunteers, and in patients with Crohn's disease, ulcerative colitis, idiopathic sprue and idiopathic hyperamylasemia by oral administration of 10 g low molecular weight polyethylene glycol (PEG-400) and quantitation of its renal excretion over the subsequent 6 hours by high performance liquid chromatography (gel permeation HPLC). The mean amount of PEG-400 excreted during the first 6 hours by the 12 patients with Crohn's disease (3.1 +/- 0.3 g, mean +/- SE) and the 8 patients with ulcerative colitis (2.6 +/- 0.3 g) was not significantly different from the amount excreted by the 24 healthy volunteers (2.9 +/- 0.1 g). The 3 patients with idiopathic sprue excreted significantly less (1.4 +/- 0.3 g, p less than 0.05) and the 3 patients with idiopathic hyperamylasemia significantly more (4.0 +/- 0.4 g, p less than 0.05) than the healthy controls. In conclusion, no alteration of intestinal permeability could be demonstrated in patients with Crohn's disease or ulcerative colitis. However, intestinal permeability was decreased in patients with idiopathic sprue and increased in those with idiopathic hyperamylasemia.

Adult↗