Milestones in the discovery of hepatitis C

The discovery of hepatitis C has been a landmark in public health as it brought the opportunity to save millions of lives through the diagnosis, prevention and cure of the disease. The combined work of three researchers, Alter H, Houghton M and Rice C, which set the basis for the diagnosis, treatment and prevention of hepatitis C apart from laying the ground work for a new approach to study infections in general and developing new antiviral agents. This is a story of a transfusion-associated infection. A series of clinical studies demonstrated the existence of an infectious agent associated with hepatitis. That was followed by the identification of what was later known to be the hepatitis C virus (HCV) and the development of diagnostic tests. It all preceded the full molecular identification and demonstration of a causal effect. Finally it ended up with the development and discovery of a new class of therapeutic drugs, the direct acting antivirals, which are now used not only to cure the disease but most probably, to eliminate the problem. This work started with Dr Alter H who demonstrated that a new virus was responsible for the majority of post-transfusion hepatitis followed by Houghton M who cloned the virus and developed the blood test to identify those cases that carried the virus. Finally, the work of Rice C demonstrated that a cloned HCV produced after applying molecular biology techniques could cause long-standing infection and cause the same disease as the one observed in humans.

Andrew K. Burroughs: a research hepatologist extraordinaire

Andrew K (Andy) Burroughs passed away in March 2014 at the early age of 60 years. Andy was one of the last of the great all round giants of hepatology. He was a consummate physician, clinical investigator and educator. Over a period of 35 years at the Royal Free Hospital Liver Unit he produced a prodigious quantity of original research and made major contributions in many areas of hepatology including portal hypertension, liver transplantation and chronic liver disease. His work on the methodology of clinical trials is carried on by the Baveno consensus meetings. From bedside clinical mastery to early molecular biology applications to diagnosis and pathology, his contributions left a mark in liver science and advanced medical science in general. He also was praised by his work in medical education particularly in post-graduate mentorship and, an admirable human touch with patients. We will not see his like again.

50 years of Hepatology: The Royal Free Hospital School of Hepatology

Writing about the history of Hepatology would necessarily imply writing about the history of the Liver Unit and the School of Hepatology created by Dr. Sheila Scherlock at the Royal Free Hospital (London). On the 70th anniversary of the creation of the first liver unit (Hammersmith Hospital) this article presents a brief account of the history, organization, structure, educational program and contributions of perhaps the first and the most influential medical research models created for the study of liver diseases: the Royal Free Hospital Liver Unit.

Alcohol and the Liver: The Return of the Prodigal Son

With the discovery of direct-acting antivirals and the prospective of viral hepatitis becoming curable, alcohol liver disease (ALD) is back to primetime. In the last 20 years, there have been many advances in the understanding of the biology, the psychology and the social and environmental factors associated with this long-known medical problem. Recent information about regional, ethnic, cultural and genetic factors seem to be relevant for the Latin American (LA) population. New approaches based on the new concepts and current information will render better results in the overall management of patients with this problem. Considering alcohol use disorder and ALD as part of the same entity managing it in a multidisciplinary approach seems to be best way to deal with this disease.

Factors associated with tobacco, alcohol, and other drug use among youth living in West Central Mexico

AIM

To determine the prevalence of drug and substance abuse among high school students in Jalisco and its association with the severity of health, behavior and psychosocial problems in order to provide evidence for possible prevention and treatment needs.

METHODS

A multi-stage random sample of Jalisco high school students was given a paper-and-pencil survey based upon an adapted version of the drug use screening inventory (DUSI) (n = 24699; n = 2832). The DUSI showed adequate psychometric characteristics in this population. The statistical analyses accommodated the complex survey design with attention to unequal probability of selection and clustering of participants within schools and regions.

RESULTS

An estimated 44% of the students had smoked tobacco, one in five students was a current smoker, and one in four students used to smoke but had not smoked for one year or more. By contrast, 6.8% of the students reported having used marijuana, cocaine, or both. Behavioral problems, deviant peer affiliation, and troubled families were independently associated with drug use. One in two students who used tobacco or alcohol had used these drugs in the past year (46% and 54%, respectively), and one in four students who used marijuana or cocaine in their lifetime had used those drugs in the past year (28% in both cases).

CONCLUSION

The rates of cocaine use as well as the proportion of current users were higher than expected among high school students and indicate changing patterns of drug use in Mexico. These results corroborate that the general trend of drug use by youth in Mexico is increasing. Results from this study help us better understand the needs of at-risk youth and the need for new treatment and prevention strategies.

Protein tolerance to standard and high protein meals in patients with liver cirrhosis

AIM

To investigate the plasma amino acid response and tolerance to normal or high protein meals in patients with cirrhosis.

METHODS

The plasma amino acid response to a 20 g mixed protein meal was compared in 8 biopsy-proven compensated cirrhotic patients and 6 healthy subjects. In addition the response to a high protein meal (1 g/kg body weight) was studied in 6 decompensated biopsy-proven cirrhotics in order to evaluate their protein tolerance and the likelihood of developing hepatic encephalopathy (HE) following a porto-caval shunt procedure. To test for covert HE, the “number connection test” (NCT) was done on all patients, and an electroencephalogram was recorded in patients considered to be at Child-Pugh C stage.

RESULTS

The changes in plasma amino acids after a 20 g protein meal were similar in healthy subjects and in cirrhotics except for a significantly greater increase (P < 0.05) in isoleucine, leucine and tyrosine concentrations in the cirrhotics. The baseline branched chain amino acids/aromatic amino acids (BCAA/AAA) ratio was higher in the healthy persons and remained stable-but it decreased significantly after the meal in the cirrhotic group. After the high protein meal there was a marked increase in the levels of most amino acids, but only small changes occurred in the levels of taurine, citrulline, cysteine and histidine.The BCAA/AAA ratio was significantly higher 180 and 240 min after the meal. Slightly elevated basal plasma ammonia levels showed no particular pattern. Overt HE was not observed in any patients.

CONCLUSION

Patients with stable liver disease tolerate natural mixed meals with a standard protein content. The response to a high protein meal in decompensated cirrhotics suggests accumulation of some amino acids but it did not precipitate HE. These results support current nutritional guidelines that recommend a protein intake of 1.2-1.5 g/kg body weight/day for patients with cirrhosis.

High frequency of the DRD2/ANKK1 A1 allele in Mexican Native Amerindians and Mestizos and its association with alcohol consumption

BACKGROUND

Mexico has an ancient tradition of alcohol drinking influenced by genetic and sociocultural factors. This study aimed to determine the distribution of the DRD2/ANKK1 TaqIA polymorphism in Mexican populations and to analyze its association with heavy drinking.

METHODS

In a cross-sectional and analytical study, 680 unrelated subjects including two Native Amerindians groups (87 Nahuas and 139 Huicholes), and two Mestizos groups (158 subjects from Tepic, Nayarit and 296 subjects from Guadalajara, Jalisco) were enrolled. DRD2/ANKK1 genotyping was performed by PCR-RFLP and allelic discrimination assays. Genetic analyses were conducted by Arlequin and Structure software. Heavy drinking was defined as ≥300g alcohol/week. The association of the DRD2/ANKK1 TaqIA polymorphism with heavy drinking was estimated.

RESULTS

Heavy drinking was prevalent in 64.7% of the study population. The DRD2/ANKK1 A1 allele prevailed in 67% and 65% of Nahuas and Huicholes, respectively and 51% and 47.3% in Mestizos from Tepic and Guadalajara, respectively. Heavy drinking was associated with the A1A1 genotype in the Mestizos of Guadalajara (A1A1 vs. A1A2 OR=4.79, 95%CI 1.81-12.68, p=0.0006; A1A1 vs. A1A2+A2A2, OR=4.09, 95%CI 1.56-10.68, p=0.0021) and in the Mestizos from Tepic (A1A1 vs. A1A2, OR=5.92, 95%CI 2.12-16.49, p=0.0002); A2A2, OR=14.56, 95%CI 3.57-59.24, p=0.00004); A1A2+A2A2, OR=6.68, 95%CI 2.42-18.42, p=0.00005). In Native Amerindians, a lack of association was found.

CONCLUSIONS

High frequencies of the DRD2/ANKK1 A1 allele were present in Mexican populations. Native Amerindians exhibited the highest frequencies of the A1 allele documented worldwide to date. The A1A1 genotype was associated with heavy drinking in Mestizos.

Mexico's precursor chemical controls: emergence of less potent types of methamphetamine in the United States

BACKGROUND

This study examines whether Mexico's controls on ephedrine and pseudoephedrine, the two precursor chemicals that yield the most potent form of methamphetamine, d-methamphetamine, impacted the prevalence/availability of less potent types of methamphetamine in the United States-types associated with the alternative precursor chemical P2P.

METHOD

Using ARIMA-intervention time series analysis of monthly drug exhibits (a prevalence/availability indicator) from the System to Retrieve Information from Drug Evidence (STRIDE), we tested whether Mexico's controls, which began in 2005, were associated with growth/decline in d-methamphetamine and growth/decline in P2P-associated, less potent l-methamphetamine, racemic methamphetamine (a 50:50 ratio of d- and l-isomers), and mixed isomer methamphetamine (an unequal ratio of d- and l-isomers). Heroin, cocaine and marijuana exhibits were used for quasi-control (01/2000-04/2011).

RESULTS

Mixed-isomer exhibits constituted about 4% of the methamphetamine exhibits before Mexico's controls, then rose sharply in association with them and remained elevated, constituting about 37% of methamphetamine exhibits in 2010. d-Methamphetamine exhibits dropped sharply; l-methamphetamine and racemic methamphetamine exhibits had small rises. d-Methamphetamine exhibits partially recovered in the US West, but little recovery occurred in the US Central/South. Quasi-control series were generally unaffected.

CONCLUSION

The US methamphetamine market changed. Widespread emergence of less potent methamphetamine occurred in conjunction with Mexico's controls. And prevalence/availability of the most potent type of the drug, d-methamphetamine, declined, a partial recovery in the West notwithstanding. Granting that lower potency drugs typically engender less dependence and attendant problems, these findings suggest that, following Mexico's controls, the potential harm of a sizeable amount of the US methamphetamine supply decreased.

Non-injection drug use and hepatitis C among drug treatment clients in west central Mexico

BACKGROUND

Research on hepatitis C virus (HCV) prevalence among non-injecting drug treatment clients in the United States, Europe and Asia indicate substantial differences by place. To date, little or no research on HCV and non-injection drug use (NIDU) has been conducted in Mexico.

METHODS

We examined the prevalence of HCV, hepatitis B virus (HBV), and HIV among non-injecting drug users (NIDUs) in community-based drug treatment (N=122) and NIDUs in a prison-based drug treatment program (N=30), both located in west central Mexico.

RESULTS

Among the community clients, prevalence was 4.1% (95% confidence interval [CI]: 1.8-9.2) for HCV, 5.7% for HBV (95% CI: 2.8-11.4), and 1.6% for HIV (95% CI: 0.4-5.8). Among the in-prison clients, prevalence was 40.0% (95% CI: 24.6-57.7) for HCV, 20.0% for HBV (95% CI: 9.5-37.3), and 6.7% for HIV (95% CI: 1.9-21.3). None of the clients were aware of being infected.

CONCLUSION

The HCV prevalence found for the NIDU community treatment clients ranks among the lower HCV estimates published for NIDUs in treatment to date. The prevalence found for the in-prison clients ranks among the higher, raising a concern of possible elevated HCV infection among NIDUs in the west central Mexico prison--one compounded by the finding that none of this study's clients knew they were HCV positive.

Mexico's methamphetamine precursor chemical interventions: impacts on drug treatment admissions

AIMS

To help counter problems related to methamphetamine, Mexico has implemented interventions targeting pseudoephedrine and ephedrine, the precursor chemicals commonly used in the drug's synthesis. This study examines whether the interventions impacted methamphetamine treatment admissions-an indicator of methamphetamine consequences.

DESIGN

Quasi-experiment: autoregressive integrated moving average (ARIMA)-based intervention time-series analysis.

INTERVENTIONS

precursor chemical restrictions implemented beginning November 2005; major rogue precursor chemical company closed (including possibly the largest single drug-cash seizure in history) March 2007; precursor chemicals banned from Mexico (North America's first precursor ban) August 2008.

SETTINGS

Mexico and Texas (1996-2008).

MEASUREMENTS

Monthly treatment admissions for methamphetamine (intervention series) and cocaine, heroin and alcohol (quasi-control series).

FINDINGS

The precursor restriction was associated with temporary methamphetamine admissions decreases of 12% in Mexico and 11% in Texas. The company closure was associated with decreases of 56% in Mexico and 48% in Texas; these decreases generally remained to the end of the study period. Neither intervention was associated with significant changes in the Mexico or Texas quasi-control series. The analysis of Mexico's ban was indeterminate due largely to a short post-ban series.

CONCLUSIONS

This study, one of the first quasi-experimental analyses of an illicit-drug policy in Mexico, indicates that the country's precursor interventions were associated with positive impacts domestically and in one of the Unites States' most populous states--Texas. These interventions, coupled with previous US and Canadian interventions, amount to a new, relatively cohesive level of methamphetamine precursor control across North America's largest nations, raising the possibility that the impacts found here could continue for an extended period.

Proximity to the US-Mexico border: a key to explaining geographic variation in US methamphetamine, cocaine and heroin purity

AIMS

Although illicit drug purity is a widely discussed health risk, research explaining its geographic variation within a country is rare. This study examines whether proximity to the US-Mexico border, the United States' primary drug import portal, is associated with geographic variation in US methamphetamine, heroin and cocaine purity.

DESIGN

Distances (proximity) between the US-Mexico border and locations of methamphetamine, cocaine and heroin seizures/acquisitions (n = 239,070) recorded in STRIDE (System to Retrieve Information from Drug Evidence) were calculated for the period of 1990-2004. The association of drug purity with these distances and other variables, including time and seizure/acquisition size, was examined using hierarchical multivariate linear modeling (HMLM).

SETTING

Coterminous United States.

FINDINGS

Methamphetamine, cocaine and heroin purity generally decreased with distance from the US-Mexico border. Heroin purity, however, after initially declining with distance, turned upwards-a U-shaped association. During 2000-04, methamphetamine purity also had a U-shaped association with distance. For each of the three drugs, temporal changes in the purity of small acquisitions (<10 g) were typically more dynamic in areas closer to the US-Mexico border.

CONCLUSIONS

Geographic variance in methamphetamine, cocaine and heroin purity throughout the coterminous United States was associated with US-Mexico border proximity. The U-shaped associations between border-distance and purity for heroin and methamphetamine may be due to imports of those drugs via the eastern United States and southeast Canada, respectively. That said, areas closer to the US-Mexico border generally had relatively high illicit drug purity, as well as more dynamic change in the purity of small ('retail level') drug amounts.

[Hepatitis C virus infection and alcohol]

It was thought that HCV infection was very frequent among alcoholics; some even though that this disease affected nearly 35% of this group. Now there seems to be a consensus among the main investigator groups that the correlation of hepatitis C and alcohol increases the risk of complications, cirrhosis and liver cancer included. Moreover, it's now certain that among patients with HCV infection, alcohol consumption increases the risk of death from live diseases during the first 10 years of the disease. Alcoholism is also considered a predisposing factor for HCV infection, but not for hepatitis B virus infection. Prospective studies about post-transfusional hepatitis C showed the risk of cirrhosis increases from 7.8 to 31.1 times if the patient consumed significant amounts of alcohol (> 80 g a day). One of the recommendations for every patient with HCV infection is to abstain from drinking alcohol.

Drinking patterns and beverage preferences of liver cirrhosis patients in Mexico

The purpose of this study was to investigate the pattern of alcoholism in a special group of alcoholics (alcoholic cirrhotics) in a hospital-based population in west central Mexico and assess the role of regional spirits such as tequila. A complete alcohol drinking history and a structured questionnaire directed at investigating the pattern of alcohol consumption was applied to 124 adult patients with chronic liver disease caused by alcohol during January 1995 to January 1996. The mean age of onset was 27 +/- 3 years in women and 18 +/- 0.5 years in men. The mean alcohol intake per week was 749 +/- 192 g for women and 1113 +/- 151 g for men. On average, patients consumed alcohol for a mean of 24.5 years. The overall patient drinking preference was for tequila followed by 96 degree Gay Lusac (G.L.), alcohol, and beer. In a subset of 70 patients three phases of alcoholism could be identified (prealcoholic, critical, and chronic). Each phase had a mean duration of at least 11 years. Beer was the dominant beverage in the prealcoholic phase while tequila was consumed more often in the other phases. In the critical phase of alcoholism an average of 337 g of alcohol were consumed per week and in the chronic phase 1765 g/week. Tequila was the overall preferred beverage in this group of alcoholics. Other beverages included beer and straight alcohol with a clear trend from less to higher concentration of alcohol throughout the drinking history. Subtle gender differences in the patterns of alcoholism may be suspected. In this group of patients the role of tequila drinking is highlighted.

[Epidemiological characteristics of liver cirrhosis at the Hospital Civil of Guadalajara]

OBJECTIVE

A prospective study of the demographic and epidemiologic characteristics of patients with liver cirrhosis at the Hospital Civil de Guadalajara within a period of one year.

MATERIAL AND METHODS

A total of 157 patients (48 women, and 109 men) from the Departments of Internal Medicine, Gastroenterology and Liver Clinic were studied. Diagnosis of liver cirrhosis had been previously established based on clinical, biochemical or histopathological information. Additionally, a questionnaire specialized on liver diseases was applied to all patients.

RESULTS

Alcoholism was the main cause for cirrhosis (38% in women and 95% in men) followed by viral etiology. The alcoholic beverages consumed with greater frequency were tequila and 96 degrees G.L. alcohol. Women were in the Child-Pugh's "B" class while men were in class "C". Complications were mostly gastrointestinal bleeding, ascites and hepatic encephalopathy. Differences between sexes were observed for various characteristics.

CONCLUSIONS

Alcoholism was by far the most frequent cause of liver cirrhosis. The second cause, in women, was of viral origin (16.7%). A national committee of vigilance of liver diseases is proposed to generate more complete and detailed information on the epidemiology of liver cirrhosis.

Antisense S-oligodeoxynucleotides down-regulate TGFbeta-production by Kupffer cells from CCl4-injured rat livers

TGFbeta is a pleiotropic cytokine involved in multiple physiological and pathophysiological regulatory mechanisms. Since TGFbeta is a disparate modulator of cell recruitment, proliferation and extracellular matrix phenotype for mesenchymal and nonmesenchymal cells, we have been investigating the role of this cytokine in the pathophysiology of liver. In the present paper we investigate which hepatic cell types from CCl4-injured rat livers express TGFbeta mRNA and produce TGFbeta in culture, with the aim of further obliterating its biological activity by means of antisense technology. We performed a series of comprehensive molecular studies of in situ hybridization, northern blots, and RT-PCR and we found that only non-parenchymal cells produce TGFbeta while its expression in hepatocytes was absent. Consistent with the in situ hybridization findings, we observed that Kupffer cells expressed high steady-state levels of TGFbeta mRNA, while circulating monocytes expressed a smaller amount of TGFbeta transcripts. We did not detect TGFbeta gene expression in endothelial cells. These findings were further confirmed by RT-PCR analyses. TGFbeta activity, as measured by inhibition of [3H]thymidine incorporation by Mv 1 Lu mink lung epithelial cells, was down-regulated in culture by antisense phosphorothioate oligonucleotides. These effects of antisense oligomers were dose-dependent and the sense oligonucleotides had no effect at the same concentration.

[Association of plasma ammonia and GABA levels and the degree of hepatic encephalopathy]

Several toxic factors have been implicated in the pathogenesis of hepatic encephalopathy (PSE) among which ammonia plays a dominant role. More recently, the gamma-aminobutyric acid (GABA) hypothesis in which an increase in the GABA-ergic tone and the presence of one or more GABA/benzodiazepine receptor ligands which interact with that receptor, has been proposed. We investigated the levels of GABA and ammonia in plasma of patients with acute PSE to test the hypothesis that elevated plasma GABA levels would be found in acute encephalopathy and that GABA levels would correlate with the degree of hepatic encephalopathy. We measured plasma levels of GABA and ammonia during an acute episode of PSE, spontaneous or precipitated by gastrointestinal bleeding or sepsis, and performed assessments of PSE by the PSE index. Patients were evaluated before and two days after standard treatment with lactulose. We also measured plasma GABA levels in the hepatic vein of a selected group of patients undergoing hemodynamic studies. Plasma GABA levels were significantly higher in patients with acute PSE (458 +/- 108 pmol/mL) when compared with normal subjects (110 +/- 23 pmol/mL) (p < 0.01) although no correlation was found between plasma GABA concentration and the degree of PSE. Changes in plasma ammonia, however, correlated with improvements in the PSE index (r = 0.56; p < 0.02) and with abnormalities in the EEG (r = 0.65; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The BCAA/AAA ratio of plasma amino acids in three different groups of cirrhotics

We studied the plasma amino acid profiles in the postabsorptive period in three groups of cirrhotic patients: stable, unstable, and with acute portal systemic encephalopathy (PSE), and compared them with a healthy control group in order to investigate the differences among the different groups and reevaluate the use of the branched-chain amino acid/aromatic amino acid (BCAA/AAA) ratio. Although plasma amino acid levels were similar to the control group, stable cirrhotics had a significantly decreased BCAA/AAA ratio (2.9 +/- 0.2) compared to the control group (3.9 +/- 0.3) (p < 0.05). Unstable cirrhotics had differences in plasma amino acid levels and the BCAA/AAA ratio was even lower (1.7 +/- 0.3) compared with stable cirrhotics and controls, respectively (p < 0.05 and p < 0.01). Patients with PSE had extreme elevations of most amino acids and showed the lowest BCAA/AAA ratio of all four groups (0.8 +/- 0.07) (p < 0.001 compared with controls). We conclude that it is possible to detect differences in plasma amino acid concentrations in different groups of cirrhotics, and that the BCAA/AAA ratio is a good index for the assessment of liver impairment. The latter could be used in the follow-up of a selected group of patients such as those undergoing major surgery or liver transplantation in whom the BCAA/AAA ratio could be used to help determine the best time for the transplant.

Acidifying enemas (lactitol and lactose) vs. nonacidifying enemas (tap water) to treat acute portal-systemic encephalopathy: a double-blind, randomized clinical trial

A double-blind, controlled trial to study the efficacy of acidifying enemas of lactitol, a new galactoside-sorbitol disaccharide, and lactose vs. nonacidifying tap-water enemas was performed in 45 episodes of acute portal-systemic encephalopathy. At the time of randomization, all patients had encephalopathy of at least Grade 2+ severity, delay in the performance of number connection tests and hyperammonemia. A sequential analysis was performed which revealed after the inclusion of the first 20 patients, a significant failure of the nonacidifying enemas as compared to the lactitol enemas (p less than 0.004). The tap-water enema group was, therefore, suspended but the rest of the study continued after rerandomization for lactose and lactitol groups. A favorable response to treatment was obtained in 19 (86%) of the patients receiving lactitol enemas and in 14 (78%) of those receiving lactose enemas. A similar significant improvement in portal-systemic encephalopathy parameters and index was observed after both treatments. Both types of acidifying enemas induced a significant pH decrease in stool (p less than 0.05). These data suggest that acidifying agents like lactose and lactitol are effective and superior to tap-water enemas for the treatment of acute nitrogenous portal-systemic encephalopathy.