Transection of the oesophagus for bleeding oesophageal varices

Emergency ligation of bleeding oesophageal varices using the Milnes Walker technique was performed in 38 patients. Haemorrhage continued or recurred in hospital in 11 patients, all of whom subsequently died. A further 10 patients died in hospital following operation from hepatic failure and a variety of other causes. Five patients were finally considered suitable for elective shunt surgery, but of 12 patients who were discharged without a further operation, only 2 have re-bled. Although the overall 6-month survival was 32 per cent, in patients with good preoperative liver function this rose to 71 per cent, and the simple scoring system for grading the severity of disturbance of liver function was found to be of value in predicting the outcome of surgery.

Since the results of emergency ligation of bleeding oesophageal varices in our hands have been so disappointing we are currently using it less and are trying the mesenteric caval jump graft as an emergency operation for the control of bleeding varices.

Panitumumab-FOLFOX4 treatment and RAS mutations in colorectal cancer

BACKGROUND

Patients with metastatic colorectal cancer that harbors KRAS mutations in exon 2 do not benefit from anti-epidermal growth factor receptor (EGFR) therapy. Other activating RAS mutations may also be negative predictive biomarkers for anti-EGFR therapy.

METHODS

In this prospective-retrospective analysis, we assessed the efficacy and safety of panitumumab plus oxaliplatin, fluorouracil, and leucovorin (FOLFOX4) as compared with FOLFOX4 alone, according to RAS (KRAS or NRAS) or BRAF mutation status. A total of 639 patients who had metastatic colorectal cancer without KRAS mutations in exon 2 had results for at least one of the following: KRAS exon 3 or 4; NRAS exon 2, 3, or 4; or BRAF exon 15. The overall rate of ascertainment of RAS status was 90%.

RESULTS

Among 512 patients without RAS mutations, progression-free survival was 10.1 months with panitumumab-FOLFOX4 versus 7.9 months with FOLFOX4 alone (hazard ratio for progression or death with combination therapy, 0.72; 95% confidence interval [CI], 0.58 to 0.90; P=0.004). Overall survival was 26.0 months in the panitumumab-FOLFOX4 group versus 20.2 months in the FOLFOX4-alone group (hazard ratio for death, 0.78; 95% CI, 0.62 to 0.99; P=0.04). A total of 108 patients (17%) with nonmutated KRAS exon 2 had other RAS mutations. These mutations were associated with inferior progression-free survival and overall survival with panitumumab-FOLFOX4 treatment, which was consistent with the findings in patients with KRAS mutations in exon 2. BRAF mutations were a negative prognostic factor. No new safety signals were identified.

CONCLUSIONS

Additional RAS mutations predicted a lack of response in patients who received panitumumab-FOLFOX4. In patients who had metastatic colorectal cancer without RAS mutations, improvements in overall survival were observed with panitumumab-FOLFOX4 therapy. (Funded by Amgen and others; PRIME ClinicalTrials.gov number, NCT00364013.).

Early indicators of prognosis in fulminant hepatic failure

The successful use of orthotopic liver transplantation in fulminant hepatic failure has created a need for early prognostic indicators to select the patients most likely to benefit at a time when liver transplantation is still feasible. Univariate and multivariate analysis was performed on 588 patients with acute liver failure managed medically during 1973-1985, to identify the factors most likely to indicate a poor prognosis. In acetaminophen-induced fulminant hepatic failure, survival correlated with arterial blood pH, peak prothrombin time, and serum creatinine--a pH less than 7.30, prothrombin time greater than 100 s, and creatinine greater than 300 mumol/L indicating a poor prognosis. In patients with viral hepatitis and drug reactions three static variables [etiology (non A, non B hepatitis or drug reactions), age less than 11 and greater than 40 yr, duration of jaundice before the onset of encephalopathy greater than 7 days] and two dynamic variables (serum bilirubin greater than 300 mumol/L and prothrombin time greater than 50 s) indicated a poor prognosis. The value of these indicators in determining outcome was tested retrospectively in a further 175 patients admitted during 1986-1987, leading to the construction of models for the selection of patients for liver transplantation.

An SCN9A channelopathy causes congenital inability to experience pain

The complete inability to sense pain in an otherwise healthy individual is a very rare phenotype. In three consanguineous families from northern Pakistan, we mapped the condition as an autosomal-recessive trait to chromosome 2q24.3. This region contains the gene SCN9A, encoding the alpha-subunit of the voltage-gated sodium channel, Na(v)1.7, which is strongly expressed in nociceptive neurons. Sequence analysis of SCN9A in affected individuals revealed three distinct homozygous nonsense mutations (S459X, I767X and W897X). We show that these mutations cause loss of function of Na(v)1.7 by co-expression of wild-type or mutant human Na(v)1.7 with sodium channel beta(1) and beta(2) subunits in HEK293 cells. In cells expressing mutant Na(v)1.7, the currents were no greater than background. Our data suggest that SCN9A is an essential and non-redundant requirement for nociception in humans. These findings should stimulate the search for novel analgesics that selectively target this sodium channel subunit.

Causes and outcomes of the acute chest syndrome in sickle cell disease. National Acute Chest Syndrome Study Group

BACKGROUND

The acute chest syndrome is the leading cause of death among patients with sickle cell disease. Since its cause is largely unknown, therapy is supportive. Pilot studies with improved diagnostic techniques suggest that infection and fat embolism are underdiagnosed in patients with the syndrome.

METHODS

In a 30-center study, we analyzed 671 episodes of the acute chest syndrome in 538 patients with sickle cell disease to determine the cause, outcome, and response to therapy. We evaluated a treatment protocol that included matched transfusions, bronchodilators, and bronchoscopy. Samples of blood and respiratory tract secretions were sent to central laboratories for antibody testing, culture, DNA testing, and histopathological analyses.

RESULTS

Nearly half the patients were initially admitted for another reason, mainly pain. When the acute chest syndrome was diagnosed, patients had hypoxia, decreasing hemoglobin values, and progressive multilobar pneumonia. The mean length of hospitalization was 10.5 days. Thirteen percent of patients required mechanical ventilation, and 3 percent died. Patients who were 20 or more years of age had a more severe course than those who were younger. Neurologic events occurred in 11 percent of patients, among whom 46 percent had respiratory failure. Treatment with phenotypically matched transfusions improved oxygenation, with a 1 percent rate of alloimmunization. One fifth of the patients who were treated with bronchodilators had clinical improvement. Eighty-one percent of patients who required mechanical ventilation recovered. A specific cause of the acute chest syndrome was identified in 38 percent of all episodes and 70 percent of episodes with complete data. Among the specific causes were pulmonary fat embolism and 27 different infectious pathogens. Eighteen patients died, and the most common causes of death were pulmonary emboli and infectious bronchopneumonia. Infection was a contributing factor in 56 percent of the deaths.

CONCLUSIONS

Among patients with sickle cell disease, the acute chest syndrome is commonly precipitated by fat embolism and infection, especially community-acquired pneumonia. Among older patients and those with neurologic symptoms, the syndrome often progresses to respiratory failure. Treatment with transfusions and bronchodilators improves oxygenation, and with aggressive treatment, most patients who have respiratory failure recover.

Long-term outcome of hepatitis C infection after liver transplantation

BACKGROUND

End-stage cirrhosis related to hepatitic C virus (HCV) is a common reason for liver transplantation, although viremia ia known to persist in most cases. We investigated the impact of persistent HCV infection after liver transplantation on patient and graft survival and the effects of the HCV genotype and the degree of HLA matching between donor and recipient on the severity of recurrent hepatitis.

METHODS

A group of 149 patients with HCV infection who received liver transplants between January 1982 and April 1994 were followed for a median of 36 months; 623 patients without HCV infection who underwent liver transplantation for end-stage chronic liver disease were used as a control group. A total of 528 liver-biopsy specimens from the HCV-infected recipients were reviewed, including 82 obtained one year after transplantation as scheduled and 39 obtained at five years as scheduled. In addition, biopsy specimens were obtained from 91 of the HCV-negative patients five years after transplantation.

RESULTS

Cumulative survival rates for the 149 patients with HCV infection were 79 percent after one year, 74 percent after three years, and 70 percent after five years, as compared with rates of 75 percent, 71 percent, and 69 percent, respectively, in the HCV-negative transplant recipients (P=0.12). Of the 130 patients with hepatitis C infection who survived more than 6 months after transplantation, 15 (12 percent) had no evidence of chronic hepatitis on their most recent liver biopsy (median followup, 20 months), 70 (54 percent) had mild chronic hepatitis (median, 35 months), 35 (27 percent) had moderate chronic hepatitis (median, 35 months), and 10 (8 percent) had cirrhosis (median, 51 months). Graft loss occurred after a median of 303 days in 27 of the 149 patients, including 5 with HCV-related cirrhosis and 3 with HCV-related cholestatic hepatitis. Infection with HCV genotype 1b was associated with more severe graft injury, whereas the primary immunosuppressive regimen used and the extent of HLA mismatching between donors and recipients had no significant effect on this variable.

CONCLUSIONS

After liver transplantation for HCV-related cirrhosis, persistent HCV infection can cause severe graft damage, and such damage is more frequent in patients infected with HCV genotype 1b than with other genotypes. After five years, the rates of graft and overall survival are similar between patients with and those without HCV infection.

Vulnerability genes or plasticity genes?

The classic diathesis-stress framework, which views some individuals as particularly vulnerable to adversity, informs virtually all psychiatric research on behavior-gene-environment (G x E) interaction. An alternative framework of 'differential susceptibility' is proposed, one which regards those most susceptible to adversity because of their genetic make up as simultaneously most likely to benefit from supportive or enriching experiences-or even just the absence of adversity. Recent G x E findings consistent with this perspective and involving monoamine oxidase-A, 5-HTTLPR (5-hydroxytryptamine-linked polymorphic region polymorphism) and dopamine receptor D4 (DRD4) are reviewed for illustrative purposes. Results considered suggest that putative 'vulnerability genes' or 'risk alleles' might, at times, be more appropriately conceptualized as 'plasticity genes', because they seem to make individuals more susceptible to environmental influences-for better and for worse.

Simple rules yield complex food webs

Several of the most ambitious theories in ecology describe food webs that document the structure of strong and weak trophic links that is responsible for ecological dynamics among diverse assemblages of species. Early mechanism-based theory asserted that food webs have little omnivory and several properties that are independent of species richness. This theory was overturned by empirical studies that found food webs to be much more complex, but these studies did not provide mechanistic explanations for the complexity. Here we show that a remarkably simple model fills this scientific void by successfully predicting key structural properties of the most complex and comprehensive food webs in the primary literature. These properties include the fractions of species at top, intermediate and basal trophic levels, the means and variabilities of generality, vulnerability and food-chain length, and the degrees of cannibalism, omnivory, looping and trophic similarity. Using only two empirical parameters, species number and connectance, our 'niche model' extends the existing 'cascade model and improves its fit ten-fold by constraining species to consume a contiguous sequence of prey in a one-dimensional trophic niche.

Echocardiographic detection of coronary artery disease during dobutamine infusion

BACKGROUND

Two-dimensional echocardiography performed during dobutamine infusion has been proposed as a potentially useful method for detecting coronary artery disease. However, the safety and diagnostic value of dobutamine stress echocardiography has not been established.

METHODS AND RESULTS

In this study, echocardiograms were recorded during step-wise infusion of dobutamine to a maximum dose of 30 micrograms/kg/min in 103 patients who also underwent quantitative coronary angiography. The echocardiograms were digitally stored and displayed in a format that allowed simultaneous analysis of rest and stress images. Development of a new abnormality in regional function was used as an early end point for the dobutamine infusion. No patient had a symptomatic arrhythmia or complications from stress-induced ischemia. Significant coronary artery disease (greater than or equal to 50% diameter stenosis) was present in 35 of 55 patients who had normal echocardiograms at rest. The sensitivity and specificity of dobutamine-induced wall motion abnormalities for coronary artery disease was 89% (31 of 35) and 85% (17 of 20), respectively. The sensitivity was 81% (17 of 21) in those with one-vessel disease and 100% (14 of 14) in those with multivessel or left main disease. Forty-one of 48 patients with abnormal echocardiograms at baseline had localized rest wall motion abnormalities. Fifteen had coronary artery disease confined to regions that had abnormal rest wall motion, and 26 had disease remote from these regions. Thirteen of 15 patients (87%) without remote disease did not develop remote stress-induced abnormalities, and 21 of 26 (81%) who had remote disease developed corresponding abnormalities.

CONCLUSIONS

Echocardiography combined with dobutamine infusion is a safe and accurate method for detecting coronary artery disease and for predicting the extent of disease in those who have localized rest wall motion abnormalities.

The systemic inflammatory response syndrome in acute liver failure

The systemic inflammatory response syndrome (SIRS) in acute liver failure (ALF), in which infection is common, has not been studied. In this study, SIRS components were recorded on admission and during episodes of infection, in 887 ALF patients admitted to a single center during an 11-year period. Overall, 504 (56.8%) patients manifested a SIRS during their illness, with a maximum of 1, 2, and 3 concurrent SIRS components in 166, 238, and 100 patients, respectively. In 353 (39.8%) patients who did not become infected, a SIRS on admission was associated with a more critical illness, subsequent worsening of encephalopathy, and death. Infected patients more often developed a SIRS and one of greater magnitude. The magnitude of the SIRS in 273 patients with bacterial infection correlated with mortality, being 16.7%, 28.4%, 41.2%, and 64.7% in patients with 0, 1, 2, and 3 maximum concurrent SIRS components, respectively. Similar correlations with mortality were seen for SIRS associated with fungal infection, bacteremia, and bacterial chest infection. Fifty-nine percent of patients with severe sepsis died, as did 98% of those with septic shock. A significant association was found between progressive encephalopathy and infection. Infected patients with progressive encephalopathy manifested more SIRS components than other infected patients. For patients with a SIRS, the proportions of infected and noninfected patients manifesting worsening encephalopathy were similar. In ALF, the SIRS, whether or not precipitated by infection, appears to be implicated in the progression of encephalopathy, reducing the chances of transplantation and conferring a poorer prognosis.

Global trends in resistance to antituberculosis drugs. World Health Organization-International Union against Tuberculosis and Lung Disease Working Group on Anti-Tuberculosis Drug Resistance Surveillance

BACKGROUND

Data on global trends in resistance to antituberculosis drugs are lacking.

METHODS

We expanded the survey conducted by the World Health Organization and the International Union against Tuberculosis and Lung Disease to assess trends in resistance to antituberculosis drugs in countries on six continents. We obtained data using standard protocols from ongoing surveillance or from surveys of representative samples of all patients with tuberculosis. The standard sampling techniques distinguished between new and previously treated patients, and laboratory performance was checked by means of an international program of quality assurance.

RESULTS

Between 1996 and 1999, patients in 58 geographic sites were surveyed; 28 sites provided data for at least two years. For patients with newly diagnosed tuberculosis, the frequency of resistance to at least one antituberculosis drug ranged from 1.7 percent in Uruguay to 36.9 percent in Estonia (median, 10.7 percent). The prevalence increased in Estonia, from 28.2 percent in 1994 to 36.9 percent in 1998 (P=0.01), and in Denmark, from 9.9 percent in 1995 to 13.1 percent in 1998 (P=0.04). The median prevalence of multidrug resistance among new cases of tuberculosis was only 1.0 percent, but the prevalence was much higherin Estonia (14.1 percent), Henan Province in China (10.8 percent), Latvia (9.0 percent), the Russian oblasts of Ivanovo (9.0 percent) and Tomsk (6.5 percent), Iran (5.0 percent), and Zhejiang Province in China (4.5 percent). There were significant decreases in multidrug resistance in France and the United States. In Estonia, the prevalence in all cases increased from 11.7 percent in 1994 to 18.1 percent in 1998 (P<0.001).

CONCLUSIONS

Multidrug-resistant tuberculosis continues to be a serious problem, particularly among some countries of eastern Europe. Our survey also identified areas with a high prevalence of multidrug-resistant tuberculosis in such countries as China and Iran.

Acute liver failure: redefining the syndromes

Existing definitions of clinical syndromes in acute liver failure do not accurately reflect important differences in clinical features and prognosis. Based on a large series of patients with acute liver failure treated at King's College Hospital, London between 1972 and 1985, we propose a new terminology. Hyperacute liver failure is our suggested term for cases in which encephalopathy occurs within 7 days of the onset of jaundice; this group includes the sizeable cohort likely to survive with medical management despite the high incidence of cerebral oedema. We suggest the term acute liver failure for cases with an interval of between 8 and 28 days from jaundice to encephalopathy; they also have a high incidence of cerebral oedema, but have a much poorer prognosis without liver transplantation. The term subacute liver failure is suggested to describe cases with encephalopathy that occurs within 5 to 12 weeks of the onset of jaundice; these patients are characterised by a low incidence of cerebral oedema, but have a poor prognosis. Adoption of this terminology should help in the management of these patients, in addition to standardising the structure and interpretation of controlled trials of therapies.

Controlled trials of charcoal hemoperfusion and prognostic factors in fulminant hepatic failure

One hundred thirty-seven patients with fulminant hepatic failure were entered into two controlled trials of charcoal hemoperfusion carried out concurrently. In trial A, 75 patients with grade 3 encephalopathy were randomized to receive 5 or 10 h of hemoperfusion daily. Overall survival rates for the two groups were similar (51.3% vs. 50.0%) as was the frequency of major complications including cerebral edema and renal failure. In trial B, in which 62 patients with established grade 4 encephalopathy on admission were randomized to a no-perfusion group or to have 10 h of hemoperfusion daily, overall survival rates for the two groups were again similar (39.3% and 34.5%, respectively). There was in both trials a significant relationship between survival and etiology quite independent of the use or duration of hemoperfusion. Thus, percentage survival for the acetaminophen-overdose cases was 52.9%, for hepatitis A 66.7%, for hepatitis B 38.9%, for presumed non-A, non-B hepatitis 20%, and for halothane or drug reaction 12.5%. Within the etiologic subgroups survival was also influenced by the three major complications that developed, being inversely related to their frequency and combination, except in the non-A, non-B hepatitis and halothane or drug reaction subgroups, which had a high mortality throughout. In the latter cases particularly, orthotopic liver transplantation merits early consideration and in the group with better "intrinsic" survival (acetaminophen, hepatitis A and B) intensive management of complications (rather than charcoal hemoperfusion) would appear to be of major importance.

Pilot-controlled trial of the extracorporeal liver assist device in acute liver failure

The objective of this pilot controlled study was to evaluate the extracorporeal liver assist device (ELAD) in patients with acute liver failure who were judged to still have a significant chance of survival (approximately 50%) and in those who had already fulfilled criteria for transplantation. Twenty-four patients were divided into two groups, 17 with a potentially recoverable lesion (group I) and 7 listed for transplantation (group II), and then randomly allocated to ELAD haemoperfusion or control. The median period of ELAD haemoperfusion was 72 hours (range 3-168 h). Biocompatibility of the device was good, with no acceleration in platelet consumption, and haemodynamic stability was maintained. Two patients were withdrawn from the study because of worsening of preexisting disseminated intravascular coagulation in one case and a hypersensitivity reaction in the other. Deterioration with respect to encephalopathy grade was more frequent in the control patients, 7 of 12 (58%), than in the ELAD-treated patients, 3 of 12 (25%). In group I where survival for the ELAD cases was 7 of 9 (78%), there was a higher than expected survival in the controls, 6 of 8 (75%). For group II cases, survival was 1 of 3 (33%) for the ELAD-treated patients, and 1 of 4 (25%) for the controls. Both of the survivors underwent transplantation. Assessment of additive function for the device revealed an improvement in galactose elimination capacity after 6 hours of haemoperfusion. Based on the results of this pilot-controlled trial, better indices of prognosis will be required, in addition to those used to select for transplantation, if patients at an earlier stage of clinical deterioration are to be included in future studies.

A longitudinal analysis of hepatitis C virus replication following liver transplantation

BACKGROUND & AIMS

The pathogenesis of graft injury in liver transplant recipients with recurrent hepatitis C virus (HCV) infection remains poorly understood. In this study, the relationship between HCV replication, genotype, and the evolution of graft damage was investigated.

METHODS

HCV RNA was quantified in 184 protocol sera from 25 patients transplanted for HCV cirrhosis. HCV isolates were genotyped, and hepatic expression of core and NS4 antigens was sought in protocol allograft biopsy specimens.

RESULTS

Acute lobular hepatitis was accompanied by a steep increase in HCV RNA levels and the appearance of core and NS4 antigens in the graft. Methylprednisolone treatment for acute rejection led to a 4-100-fold increase in serum HCV RNA. At the end of follow-up, HCV RNA levels were 3-112 times pretransplant levels and were higher in patients with more severe hepatitis. Progressive liver damage developed in 7 of 14 patients with HCV genotype 1b and in 1 of 11 patients infected with other genotypes (P = 0.03).

CONCLUSIONS

Peak viremia levels and the initial detection of HCV antigens in hepatocytes suggests increased viral replication at the time of acute HCV hepatitis in the graft. Genotype 1b and higher viremia levels were associated with more severe chronic graft damage.

Copper coordination in blue proteins

The spectroscopic and electrochemical properties of blue copper proteins are strikingly different from those of inorganic copper complexes in aqueous solution. Over three decades ago this unusual behavior was ascribed to constrained coordination in the folded protein; consistent with this view, crystal structure determinations of blue proteins have demonstrated that the ligand positions are essentially unchanged on reduction as well as in the apoprotein. Blue copper reduction potentials are tuned to match the particular function of a given protein by exclusion of water from the metal site and strict control of the positions of axial ligands in the folded structure. Extensive experimental work has established that the reorganization energy of a prototypal protein, Pseudomonas aeruginosa azurin, is approximately 0.7 eV, a value that is much lower than those of inorganic copper complexes in aqueous solution. The lowered reorganization energy in the protein, which is attributable to constrained coordination, is critically important for function, since the driving forces for electron transfer often are low (approximately 0.1 eV) between blue copper centers and distant (>10 A) donors and acceptors.

Improvement by acetylcysteine of hemodynamics and oxygen transport in fulminant hepatic failure

BACKGROUND

When administered early after an overdose of acetaminophen, intravenous acetylcysteine prevents hepatic necrosis by replenishing reduced stores of glutathione. How acetylcysteine improves the survival of patients with established liver damage induced by acetaminophen, however, is unknown. This study was undertaken to determine whether the beneficial effect of acetylcysteine under such circumstances could be due to enhancement of oxygen delivery and consumption.

METHODS

We studied the effect of acetylcysteine on systemic hemodynamics and oxygen transport in 12 patients with acetaminophen-induced fulminant hepatic failure and 8 patients with acute liver failure from other causes. The acetylcysteine was given in a dose of 150 mg per kilogram of body weight in 250 ml of 5 percent dextrose over a period of 15 minutes and then in a dose of 50 mg per kilogram in 500 ml of 5 percent dextrose over a period of 4 hours; measurements were made before treatment began and after 30 minutes of the regimen.

RESULTS

In the patients with acetaminophen-induced liver failure, the infusion of acetylcysteine resulted in an increase in mean oxygen delivery from 856 to 975 ml per minute per square meter of body-surface area (P = 0.0036), due to an increase in the cardiac index from 5.6 to 6.7 liters per minute per square meter (P = 0.0021). Mean arterial pressure rose from 88 to 95 mm Hg (P = 0.0054) despite a decrease in systemic vascular resistance from 1296 to 1113 dyn.sec.cm-5 per square meter (P = 0.027). There was an increase in oxygen consumption from 127 to 184 ml per minute per square meter (P = 0.0007) associated with an increase in the oxygen-extraction ratio from 16 to 21 percent (P = 0.022). The effects in the patients with acute liver failure from other causes were similar.

CONCLUSIONS

The increase in oxygen delivery and consumption in response to acetylcysteine may account for its beneficial effect on survival in patients with fulminant hepatic failure induced by acetaminophen.

New hepatitis C virus (HCV) genotyping system that allows for identification of HCV genotypes 1a, 1b, 2a, 2b, 3a, 3b, 4, 5a, and 6a

Recent studies have focused on whether different hepatitis C virus (HCV) genotypes are associated with different profiles of pathogenicity, infectivity, and response to antiviral therapy. The establishment of a simple and precise genotyping system for HCV is essential to address these issues. A new genotyping system based on PCR of the core region with genotype-specific PCR primers for the determination of HCV genotypes 1a, 1b, 2a, 2b, 3a, 3b, 4, 5a, and 6a was developed. A total of 607 samples (379 from Japan, 63 from the United States, 53 from Korea, 35 from Taiwan, 32 from China, 20 from Hong Kong, 15 from Australia, 6 from Egypt, 3 from Bangladesh, and 1 from South Africa) were tested by both the assay of Okamoto et al. (H. Okamoto, Y. Sugiyama, S. Okada, K. Kurai, Y. Akahane, Y. Sugai, T. Tanaka, K. Sato, F. Tsuda, Y. Miyamura, and M. Mayumi, J. Gen. Virol. 73:673-679, 1992) and this new genotyping system. Comparison of the results showed concordant results for 539 samples (88.8%). Of the 68 samples with discordant results, the nucleotide sequences of the HCV isolates were determined in 23, and their genotypes were determined by molecular evolutionary analysis. In all 23 samples, the assignment of genotype by our new genotyping system was correct. This genotyping system may be useful for large-scale determination of HCV genotypes in clinical studies.

Predicted exposures to steroid estrogens in U.K. rivers correlate with widespread sexual disruption in wild fish populations

Steroidal estrogens, originating principally from human excretion, are likely to play a major role in causing widespread endocrine disruption in wild populations of the roach (Rutilus rutilus), a common cyprinid fish, in rivers contaminated by treated sewage effluents. Given the extent of this problem, risk assessment models are needed to predict the location and severity of endocrine disruption in river catchments and to identify areas where regulation of sewage discharges to remove these contaminants is necessary. In this study we attempted to correlate the extent of endocrine disruption in roach in British rivers, with their predicted exposure to steroid estrogens derived from the human population. The predictions of steroid estrogen exposure at each river site were determined by combining the modeled concentrations of the individual steroid estrogens [17beta-estradiol (E2), estrone (E1), and 17alpha-ethinylestradiol (EE2)] in each sewage effluent with their predicted dilution in the immediate receiving water. This model was applied to 45 sites on 39 rivers throughout the United Kingdom. Each site studied was then categorized as either high, medium, or low "risk" on the basis of the assumed additive potency of the three steroid estrogens calculated from data derived from published studies in various cyprinid fish species. We sampled 1,438 wild roach from the predicted high-, medium-, and low-risk river sites and examined them for evidence and severity of endocrine disruption. Both the incidence and the severity of intersex in wild roach were significantly correlated with the predicted concentrations of the natural estrogens (E1 and E2) and the synthetic contraceptive pill estrogen (EE2) present. Predicted steroid estrogen exposure was, however, less well correlated with the plasma vitellogenin concentration measured in the same fish. Moreover, we found no correlation between any of the end points measured in the roach and the proportion of industrial effluents entering the rivers we studied. Overall, our results provide further and substantive evidence to support the hypothesis that steroidal estrogens play a major role in causing intersex in wild freshwater fish in rivers in the United Kingdom and clearly show that the location and severity of these endocrine-disrupting effects can be predicted.

Attentional bias in anxiety and depression: the role of awareness

Attentional biases were assessed with a probe detection task in anxious (N = 17), depressed (N = 17) and normal control (N = 15) subjects. Word pairs were presented visually, with a dot probe following one word of each pair. Allocation of attention to the spatial position of the words was determined from response latencies to the probes. Half the word pairs were presented supraliminally, half subliminally. The anxious and depressed groups showed an attentional bias towards supraliminal negative words, in comparison with normal controls. The depressed group unexpectedly showed greater vigilance for supraliminal anxiety-relevant words than the anxious group. The anxious group shifted their attention towards the spatial location of negative words presented subliminally. The results support the hypothesis of an anxiety-related bias in preconscious processes.

Hepatitis C virus antibodies in chronic active hepatitis: pathogenetic factor or false-positive result?

An enzyme immunoassay (Ortho-HCV ELISA) for antibodies against the hepatitis C virus (HCV) was used to test 143 serum samples from 53 patients with autoimmune chronic active hepatitis (AI-CAH). Optical density (OD) values in the assay correlated closely with serum globulin (r = 0.8846, p much less than 0.0005) and IgG (r = 0.6281, p less than 0.0005) concentrations but not with immunosuppressant therapy. OD values were positive in 20 (65%) of 31 with active disease and in only 1 (5%) of 22 in remission (p less than 0.0005). The association between positive results and active disease and high serum globulin levels was confirmed by serial studies in 6 of the patients. In contrast, none of 31 patients with primary biliary cirrhosis and only 2 of 24 with non-hepatic disorders associated with high IgG concentrations were positive, and these controls showed no correlation between OD values and serum globulins or IgG. The findings suggest that serum from AI-CAH patients may contain a component that gives false-positive results in the assay.