Genetic differentiation of Liparus glabrirostris (Curculionidae: Molytinae) populations from the fragmented habitats of the Alps and Carpathian Mountains.

Populations of Liparus glabrirostris (Curculionidae: Molytinae), a weevil inhabiting higher altitudes of Central Europe, were sampled from 24 localities in the Alps and Carpathian Mountains, and the geographical structuring of genetic variation was analyzed. Comparison of the concatenated mitochondrial cytochrome oxidase subunit I and subunit II sequences revealed consistent genetic divergence between the populations of L. glabrirostris from different mountain ranges. In phylogenetic analysis using maximum parsimony and median-joining networks, concatenated mitochondrial haplotypes from the Alps and Carpathians clustered as separate lineages, with high bootstrap support. Substantial genetic distances determined between the separated groups ranged from 2.6 to 3.0%, with divergence estimated to have initiated approximately 0.85-0.98 million years ago. The nuclear elongation factor 1α gene was additionally amplified and haplotype analysis showed very low evolutionary divergence (0.2%), with separate clustering as well. The observed divergence suggests that the populations have been isolated for a long time, as a consequence of environmental changes resulting in varying fragmentation of habitats in the Alps and Carpathians, interrupting genetic exchange events and altering the genetic structure of L. glabrirostris populations. On the other hand, comparison of morphological characteristics showed no differences to confirm genetically well differentiated groups of populations. A polymerase chain reaction and restriction fragment length polymorphism-based method was therefore developed to discriminate between the Alpine and Carpathian lineages.

Randomized clinical trial comparing neurological outcomes after carotid endarterectomy or stenting.

BACKGROUND: Silent infarction in the brain can be detected in around 34 per cent of patients after carotid endarterectomy (CEA) and 54 per cent after carotid angioplasty and stenting (CAS). This study compared the risk of new infarctions in the brain in patients undergoing CEA or CAS. METHODS: Consecutive patients with internal carotid artery (ICA) stenosis exceeding 70 per cent were screened for inclusion in this prospective study. Patients with indications for intervention, and eligible for both methods, were allocated randomly to CEA or CAS. Neurological examination, cognitive function tests and MRI of the brain were undertaken before and 24 h after intervention. RESULTS: Of 150 randomized patients, 73 (47 men; mean age 64·9(7·1) years) underwent CEA and 77 (58 men; 66·4(7·5) years) had CAS. New infarctions on MRI were found more frequently after CAS (49 versus 25 per cent; P = 0·002). Lesion volume was also significantly greater after CAS (P = 0·010). Multiple logistic regression analyses identified intervention in the right ICA as the only independent predictor of brain infarction (odds ratio 2·10, 95 per cent c.i. 1·03 to 4·25; P = 0·040). Stroke or transient ischaemic attack occurred in one patient after CEA and in two after CAS. No significant differences were found in cognitive test results between the groups. CONCLUSION: These data confirm a higher risk of silent infarction in the brain on MRI after CAS in comparison with CEA, but without measurable change in cognitive function. REGISTRATION NUMBER: NCT01591005 ( http://www.clinicaltrials.gov).

[Combined gunshot injuries of the heart and lungs]. / Kombinierte Schussverletzung des Herzens und der Lunge.

The authors present a case report of a 38-year-old man who suffered combined gunshot injuries of the heart and lungs from a small caliber gun. The gunshot resulted in combined injuries of a penetrating wound of the left lung, the right heart chambers and the right lung which were successfully managed despite a delay in surgery of several hours by pledget sutures of the heart wounds, wedge resection of the lingula and right lower lung lobectomy performed via a clamshell thoracotomy.

Low temperature storage of larvae and synchronization of adult emergence in the predatory midge Aphidoletes aphidimyza.

Diapause larvae of Aphidoletes aphidimyza were stored at a temperature of 3 degrees C under continuous darkness for up to 7 months with survival rates above 50%; after storage for 1 year the survival rate dropped to 12%. Diapause was terminated in the majority of individuals within 120 days of chilling under storage conditions. Brief exposure (10-60 s) to the vapor of n-hexane appeared to be a useful alternative to chilling for the termination of diapause. The larvae with terminated diapause required, on average, an additional 31 days at 22 degrees C and long-day conditions in order to reach the adult stage. The 10-90% adult emergence spanned a period of 21.1 days. When the larvae with terminated diapause were exposed to 30 degrees C for 1 week after the end of low temperature storage, the survival rate was not affected, the average "time-to-adult" shortened moderately to 28 days, and the synchrony of adult emergence improved considerably to 10 days. Low temperature storage of nondiapause larvae resulted in a decrease in survival from 98 to 31% during the first 60 days of storage. Nondiapause larvae did not enter diapause during low temperature storage and, as a consequence, the adults emerged relatively rapidly (after 14-15 days) and synchronously (within 2-3 days) after the end of storage. Directions for future research, which might bring further improvement in low temperature storability and synchrony of adult emergence in A. aphidimyza, are proposed.

Hearing loss in space.

BACKGROUND: Temporary and, in some cases, permanent hearing loss has been documented after long-duration spaceflights. METHODS: We examined all existing published data on hearing loss after space missions to characterize the losses. RESULTS: Data from Russian missions suggest that the hearing loss, when it occurs, affects mainly mid to high frequencies and that using hearing protection often might prevent the loss. Several significant questions remain about hearing loss in space. While the hearing loss has been presumed to be noise-induced, no clear link has been established between noise exposure and hearing loss during spaceflight. In one documented case of temporary hearing loss from the Shuttle-Mir program, the pattern of loss was atypical for a noise-induced loss. Continuous noise levels that have been measured on the Mir and previous space stations, while above engineering standards, are not at levels usually associated with hearing loss in ground-based studies (which have usually been limited to 8-10 h exposure periods). Attempts to measure hearing in space using threshold-based audiograms have been unsuccessful in both the American and Russian programs due to noise interference with the measurements. CONCLUSIONS: The existing data highlight the need for reliable monitoring of both hearing and noise in long-duration spaceflight.

Occurrence of urinary tract tumors in miners highly exposed to dinitrotoluene.

Between 1984 and 1997, six cases of urothelial cancer and 14 cases of renal cell cancer occurred in a group of 500 underground mining workers in the copper-mining industry of the former German Democratic Republic, with high exposures to explosives containing technical dinitrotoluene. Exposure durations ranged from 7 to 37 years, and latency periods ranged from 21 to 46 years. The incidences of both urothelial and renal cell tumors in this group were much higher than anticipated on the basis of the cancer registers of the German Democratic Republic by factors of 4.5 and 14.3, respectively. The cancer cases and a representative group of 183 formerly dinitrotoluene-exposed miners of this local industry were interviewed for their working history and grouped into four exposure categories. This categorization of the 14 renal cell tumor cases revealed no dose-dependency concerning explosives in any of the four exposure categories and was similar to that of the representative group of employees, whereas the urothelial tumor cases were predominantly confined to the high-exposure categories. Furthermore, all identified tumor patients were genotyped by polymerase chain reaction, using lymphocyte DNA, regarding their genetic status of the polymorphic xenobiotic metabolizing enzymes, including the N-acetyltransferase 2 and the glutathione-S-transferases M1 and T1. This genotyping revealed remarkable distributions only for the urothelial tumor cases, who were exclusively identified as "slow acetylators." This points to the possibility of human carcinogenicity of dinitrotoluene, with regard to the urothelium as the target tissue.

[Virus titre and histological inflammation activity in chronic hepatitis C]. / Virustiter und histologische Entzündungsaktivität bei chronischer Hepatitis C.

We determine the correlation between viremia in serum specimens, transaminase activity (ALT and AST) and histological grading in 37 patients with chronic hepatitis C. In addition we compared two PCR methods for hepatitis C virus (HCV)-RNA in serum specimens. For the histological grading we used a modified Knodell score. For detection and quantification we measured the viremia (HCV-RNA titer) with a standardized "nested primer" PCR (end-point dilution method) and the commercially available Amplicor HCV Monitor. The mean HCV-RNA and AST level was significantly higher in patients with a histologically active inflammation. In the individual patient we could not conclude from the titer of HCV-RNA on the histologic grading because of the wide range of the results. We did not find a significant difference in ALT in patients having varying histological gradings. HCV-RNA titer and transaminases (ALT and AST) did not correlate significantly. The HCV-RNA titer was significantly marked in older patients (above 40 years) and patients having sporadic hepatitis than in younger patients and patients with chronic hepatitis after drug abuse. The "nested primer" PCR (end-point dilution method) was more sensitive for detection of HCV-RNA in serum specimens than Amplicor HCV Monitor. The lack of HCV-RNA with Amplicor HCV Monitor in 12 of 37 patients (32%) did not rule out viremia. We conclude that in patients with a chronic hepatitis C marked viremia points to a histologically active inflammation. In the individual patient we could not conclude from the titer of HCV-RNA on the histological grading. Because of the lower sensitivity of Amplicor HCV Monitor it is necessary to confirm negative results with a "nested primer" PCR.

[Endoscopic therapy of bile leakage following laparoscopic cholecystectomy]. / Endoskopische Therapie bei Galleleck nach laparoskopischer Cholezystektomie.

Biliary leakages are more frequent in laparoscopic than in open cholecystectomy. The aim of our study was to evaluate the diagnostic and therapeutic value of endoscopic retrograde cholangiography (ERC) in the management of bile leakages after laparoscopic cholecystectomy. The primary management was endoscopic sphincterotomy and extraction of remaining gallstones in the common bile duct to provide a decrease of biliary pressure, allowing closure of the fistulas. We report on 20 patients with bile leakage at ERCP, presenting between January 1991 and October 1995 with persistent bile discharge out of drainages, increasing fluid collections subhepatic (termed bilomas) or in the free peritoneal cavity (cholascos), abdominal pain, fever, cholestasis, intraoperatively diagnosed choledocholithiasis, and subhepatic abscess in one case. In 19 cases, after fluoroscopic visualization of the biliary tree and the leak, endoscopic sphincterotomy was performed. The biliary leaks were located at the cystic duct remnant (n = 12), at the gallbladder fossa (n = 5), or at lesions at the hepatic or common bile duct (n = 2). In 7 patients residual common bile duct stones were endoscopically removed. Most patients had localized small subhepatic fluid collections (n = 13) and the others had cholascos (n = 6). The leaks closed with endoscopic sphincterotomy alone in 11 patients, 4 patients had endoscopic sphincterotomy plus percutaneous or laparoscopic drainage of the bile collections, and 4 patients underwent laparotomy. All 6 cases with cholascos but only 2 of the 13 patients with localized collections underwent a second therapeutic procedure (drainage, laparotomy). Five of these procedures were performed within 7 days of ERCP, in most cases due to persistent bile leak. We conclude that biliary leakages after laparoscopic cholecystectomy require laparotomy only exceptionally. Endoscopic sphincterotomy, combined with percutaneous drainage in the case of large collections, represents a safe and successful strategy ensuring closure of the leaks in most cases.

[Transaminases and histological activity in chronic hepatitis C]. / Transaminasen und histologische Aktivität bei chronischer Hepatitis C.

The purpose of our study was to verify the correlation between biochemical and histological inflammatory activity in chronic hepatitis C. The histological activity index (HAI) of 42 patients with chronic hepatitis C was correlated with their transaminase activity. There was indeed a significant correlation between histological activity and the AST (r = 0.54, p = 0.0002) and ALT level (r = 0.36, p = 0.018) respectively. Due to considerable scatter of the results, transaminase activity did not allow reliable assessment of inflammatory activity in individual cases. In the majority, markedly elevated transaminase activity was associated with marked histological inflammatory activity, whereas normal or slightly elevated transaminase activity was found in all stages of inflammatory activity. To assess inflammatory activity in chronic hepatitis C, a liberal indication for liver biopsy should therefore be adopted.

[Significance of hepatitis C virus antibodies in asymptomatic blood donors]. / Bedeutung von Hepatitis-C-Virus-Antikörpern bei asymptomatischen Blutspendern.

The aim of the study was to determine the frequency and course of hepatitis C viremia in clinically healthy, anti-HCV positive test subjects, and to ascertain whether the HCV antibodies of the IgM type differed between viremia and immunity. In 21 anti-HCV positive blood donors (test subjects) with normal transaminase activity, two serum samples, taken at an interval of 25 +/- 10 months, have been investigated for HCV-RNA and HCV-IgM antibodies. In a total of 16 test subjects (76%) HCV-RNA was found during the first test and/or the follow-up: 14 of them were positive on both occasions, and one test subject each was HCV-RNA positive exclusively at the first test and the follow-up respectively. At the time of the follow-up the serum transaminase level was elevated in 4 test subjects. 3 of these 4 were HCV-RNA positive also. On the other hand, the results of the HCV-PCR were nonuniform in HCV-IgM antibody negative test subjects. The above results demonstrate that in the majority of clinically healthy, anti-HCV positive test subjects with normal transaminase activity, a viremia exists which persists and the course of which may include inflammatory phases. The proof of HCV-IgM antibodies correlates with a viremia. On the other hand, the lack of HCV-IgM antibodies does not exclude viremia.

[Endoscopic papillotomy in benign biliary tract diseases: nature, frequency and severity of complications]. / Endoskopische Papillotomie bei gutartigen Gallenwegserkrankungen: Art, Häufigkeit und Schweregrad der Komplikationen.

The purpose of this study was to evaluate the frequency, nature and significance of the complications of endoscopic sphincterotomy. Between 1989 and 1993 endoscopic sphincterotomy was performed in 973 patients with benign affections of the bileducts. 398 patients were our own and 575 were admitted from other hospitals. The complications were recorded retrospectively on the basis of the discharge reports, which were available for each of our own patients (group A) and for 85% of the admitted patients (group B). Complications in all group A patients mentioned in the discharge reports were recorded and their clinical relevance was evaluated based on the patient records. Complications were mentioned in the reports of 82 (9.2%) of 887 cases and were more frequent in patients of group B (52 of 489: 10.6%) than in patients of group A (30 of 398: 7.6%). Pancreatitis was mentioned significantly more frequent in group B (2.5% vs 5.7%, p < 0.02). Reviewing the patient records of group A showed that clinically significant complications occurred in only 8 (2%) of 398 cases. The other complications mentioned in the discharge reports could not be confirmed or were without clinical significance. Hospitalization was short for these patients (5.3 +/- 2.2 days), which points to the fact that the findings were insignificant. 2 (0.2%) of 887 patients underwent surgery and 2 (0.2%) of 887 patients died due to a complication. These results clearly show that the complication rate determined on the basis of the discharge reports alone overestimates the true morbidity of the procedure. Often, an elevated amylase after ERCP/endoscopic sphincterotomy was erroneously interpreted as a pancreatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

[The value of ERCP in the diagnosis and therapy of complications of laparoscopic cholecystectomy]. / Stellenwert der ERCP bei der Diagnostik und Therapie von Komplikationen der laparoskopischen Cholezystektomie.

Biliary complications are more frequent in laparoscopic than in open cholecystectomy. The aim of the study was to evaluate the diagnostic and therapeutic value of endoscopic retrograde cholangiopancreatography (ERCP) in the management of complications of laparoscopic cholecystectomy. We therefore report on the result of 49 ERCP after laparoscopic cholecystectomy done at our department between January 1991 and March 1993. Patients were referred from 16 different surgical institutions. In 29 cases endoscopic sphincterotomy was performed without complications. Indications for ERCP were "persistent biliary pain" (n = 27), bile leakage (n = 7), pancreatitis (n = 5), abscess (n = 5), painless jaundice (n = 3) and asymptomatic bile duct stone in routine cholangiography (n = 2). In the group of patients with "persistent biliary pain" we found bile duct stones in 12 (80%) of 15 cases with cholestasis and in 3 (30%) of 10 without cholestasis. The stones were endoscopically removed after sphincterotomy. In 2 patients without cholestasis, cannulation of the bile duct failed. 7 patients showed biliary leakage, 4 from inadequate clipping of the cystic stump (2 in combination with a common bile duct stone), 2 from the hepatic duct and 1 from insufficient anastomosis after reconstruction of a common bile duct. After endoscopic sphincterotomy and, if necessary, stone extraction by Dormia basket, leakage from the cystic stump and hepatic duct healed. The insufficient common bile duct anastomosis required reconstruction by hepaticojejunostomy. Three of 5 patients with postoperative pancreatitis had common bile duct stones, while one with chronic pancreatitis had a concrement in the pancreatic duct which was endoscopically removed.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic viral hepatitis B and C: an argument against the conventional classification of chronic hepatitis.

The classification of chronic hepatitis distinguishing benign chronic persistent hepatitis from severe chronic active hepatitis was constructed without knowledge of well-defined aetiological factors. Better understanding of the different hepatitis-viruses has shed new light on this subject. Chronic viral hepatitis B and C each show typical histological patterns. The validity of the conventional classification has been evaluated by a comparative study of chronic viral hepatitis B and C. 130 biopsies from 110 patients with chronic hepatitis C (CH-C) proven serologically by antibodies (second generation testing) were compared with 105 biopsies from 73 patients with chronic hepatitis B (CH-B). These were scored semi-quantatively. In CH-C, lymphoid follicles and/or aggregates were found in 88.5%, fatty degeneration in 51%, bile duct lesions in 46.2%, and Mallory body-like material in the hepatocytes in 9.2%. The portal lymphocytic infiltration generally predominated over the necro-inflammatory lesions of the parenchyma. Chronic persistent hepatitis (defined by the presence of portal hepatitis) was present exclusively in CH-C. Chronic lobular hepatitis was found exclusively in CH-B. We conclude that the histological criteria described for CH-C are highly suggestive of the diagnosis, that the artificial subdivision of chronic hepatitis into CPH and CAH is obsolete and that the histological assessment of chronic hepatitis should consist of a grading of inflammatory activity (minimal, mild, moderate, severe) and staging of fibrosis (extent of distortion of architecture). The final diagnosis should be based on the demonstration of the aetiological agent.

[Polymerase chain reaction in hepatitis C: increased sensitivity via amplification of shorter cDNA fragments]. / Polymerase-Kettenreaktion bei Hepatitis C: höhere Sensitivität durch Amplifikation von kürzeren cDNS-Fragmenten.

The aim of our study was to compare the sensitivity of hepatitis C virus polymerase chain reaction (HCV-PCR) by use of two different primer sets which amplify PCR products of different length. Serum samples of 70 patients with chronic hepatitis C were tested by "nested primer" PCR, using either "NCR primers" that amplify cDNA-fragments of 340 basepairs (bp), or by "PT primers" which amplify fragments of 59 bp only. HCV-RNA was detected in 40 patients (57%) by "NCR primers" and in 69 patients (90%) by "PT primers" (p < 0.001). 23 of 70 patients (33%), which were HCV-RNA negative by "NCR primers", were positive by "PT primers", but no patient negative by "PT primers" was found to be positive by "NCR primers". 20 healthy controls tested by both primer sets were all HCV-RNA negative. We conclude that the sensitivity of HCV-PCR is significantly improved by use of primers that amplify "short" PCR products and recommend the use of "PT primers" for HCV-PCR.

[Heterosexual transmission of hepatitis-C virus]. / Heterosexuelle Ubertragung des 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.

[Second generation hepatitis-C virus test and polymerase chain reaction in anti-C 100 negative patients with chronic non-A, non-B hepatitis]. / Hepatitis-C-Virus-Test der zweiten Generation und Polymerase-Kettenreaktion bei anti-C 100-negativen Patienten mit chronischer 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)

[Determination of serum calcitonin using a non-commercial RIA method]. / Stanovení kalcitoninu v séru nekomercní RIA metodou.

A radioimmunoanalytical determination of the immunoreactive calcitonine in the humen serum was worked out using the authors' own specific antiserum, the preparation and properties of which are reported in the present paper. The precision and reliability of the analytical procedure is within the usual limits (the intraserial variation coefficient was 8.6%, the calculated sensitivity was 6 pg/ml). The reported procedure was employed to determine calcitonine in a larger number of patients who were examined because of suspected medullar carcinoma of the thyroid gland and in patients suffering from other thyropathies. The results are discussed from the viewpoint of heterogeneity of calcitonine in the circulation.

[Hepatitis-C virus and hepatoma]. / Hepatitis-C-Virus und Hepatom.

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.

[Anti-HCV test in patients with chronic non-A, non-B hepatitis]. / Anti-HCV-Test bei Patienten mit chronischer 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.