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ContextThe evaluation of competence in the health professions is of great importance to the public and professionals alike. Recent efforts to design dependable and accurate systems of assessment for demanding clinical roles are increasingly attempting to focus on all-round competence of practitioners. Many challenges are faced in this field as a balance between robust assessment methodology and feasibility in practice is crucial to implementation and adoption. ObjectivesThe authors discuss some of the challenges faced by educators and clinicians involved in the development of systems of assessment for the health professions, and describe a method which aims to address these issues in the assessment of postgraduate dental training in Scotland. DiscussionThree of the major challenges facing educators and clinicians involved in the design of competency-based systems of assessment are considered: the requirement for evaluation in different areas of competence; the importance of association of assessment with the training objectives, and the types and focus of the assessment introduced. Issues around the use of formative and summative assessment, and the perception that these must always remain completely separate, are discussed in detail. SolutionsA proposal is made for the introduction of a method of assessment which has been designed keeping these challenges in mind. The rationale behind this assessment method is described. [ABSTRACT FROM AUTHOR]

BIN1 is the most important risk locus for Late Onset Alzheimer's Disease (LOAD), after ApoE. BIN1 AD-associated SNPs correlate with Tau deposition as well as with brain atrophy. Furthermore, the level of neuronal-specific BIN1 isoform 1 protein is decreased in sporadic AD cases in parallel with neuronal loss, despite an overall increase in BIN1 total mRNA. To address the relationship between reduction of BIN1 and neuronal cell loss in the context of Tau pathology, we knocked-down endogenous murine Bin1 via stereotaxic injection of AAV-Bin1 shRNA in the hippocampus of mice expressing Tau P301S (PS19). We observed a statistically significant reduction in the number of neurons in the hippocampus of mice injected with AAV-Bin1 shRNA in comparison with mice injected with AAV control. To investigate whether neuronal loss is due to deletion of Bin1 selectively in neurons in presence Tau P301S, we bred Bin1flox/flox with Thy1-Cre and subsequently with PS19 mice. Mice lacking neuronal Bin1 and expressing Tau P301S showed increased mortality, without increased neuropathology, when compared to neuronal Bin1 and Tau P301S-expressing mice. The loss of Bin1 isoform 1 resulted in reduced excitability in primary neurons in vitro, reduced neuronal c-fos expression as well as in altered microglia transcriptome in vivo. Taken together, our data suggest that the contribution of genetic variation in BIN1 locus to AD risk could result from a cell-autonomous reduction of neuronal excitability due to Bin1 decrease, exacerbated by the presence of aggregated Tau, coupled with a non-cell autonomous microglia activation.

We present the complete mitochondrial genome of Carausius morosus from Salinas, CA. The mitochondrial genome of C. morosus is circular, AT rich (78.1%), and 16,671 bp in length. It consists of 13 protein-coding, 22 transfer RNA, and 2 ribosomal RNA genes and is identical in gene content to Carausius sp., Competing Interests: The authors declare no conflict of interest.

Background: Atopic eczema (AE), also known as atopic dermatitis, is a chronic inflammatory skin condition that causes significant burden. Phototherapy is sometimes used to treat AE when topical treatments, such as corticosteroids, are insufficient or poorly tolerated., Objectives: To assess the effects of phototherapy for treating AE., Search Methods: We searched the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov to January 2021., Selection Criteria: We included randomised controlled trials in adults or children with any subtype or severity of clinically diagnosed AE. Eligible comparisons were any type of phototherapy versus other forms of phototherapy or any other treatment, including placebo or no treatment., Data Collection and Analysis: We used standard Cochrane methodology. For key findings, we used RoB 2.0 to assess bias, and GRADE to assess certainty of the evidence. Primary outcomes were physician-assessed signs and patient-reported symptoms. Secondary outcomes were Investigator Global Assessment (IGA), health-related quality of life (HRQoL), safety (measured as withdrawals due to adverse events), and long-term control., Main Results: We included 32 trials with 1219 randomised participants, aged 5 to 83 years (mean: 28 years), with an equal number of males and females. Participants were recruited mainly from secondary care dermatology clinics, and study duration was, on average, 13 weeks (range: 10 days to one year). We assessed risk of bias for all key outcomes as having some concerns or high risk, due to missing data, inappropriate analysis, or insufficient information to assess selective reporting. Assessed interventions included: narrowband ultraviolet B (NB-UVB; 13 trials), ultraviolet A1 (UVA1; 6 trials), broadband ultraviolet B (BB-UVB; 5 trials), ultraviolet AB (UVAB; 2 trials), psoralen plus ultraviolet A (PUVA; 2 trials), ultraviolet A (UVA; 1 trial), unspecified ultraviolet B (UVB; 1 trial), full spectrum light (1 trial), Saalmann selective ultraviolet phototherapy (SUP) cabin (1 trial), saltwater bath plus UVB (balneophototherapy; 1 trial), and excimer laser (1 trial). Comparators included placebo, no treatment, another phototherapy, topical treatment, or alternative doses of the same treatment. Results for key comparisons are summarised (for scales, lower scores are better): NB-UVB versus placebo/no treatment There may be a larger reduction in physician-assessed signs with NB-UVB compared to placebo after 12 weeks of treatment (mean difference (MD) -9.4, 95% confidence interval (CI) -3.62 to -15.18; 1 trial, 41 participants; scale: 0 to 90). Two trials reported little difference between NB-UVB and no treatment (37 participants, four to six weeks of treatment); another reported improved signs with NB-UVB versus no treatment (11 participants, nine weeks of treatment). NB-UVB may increase the number of people reporting reduced itch after 12 weeks of treatment compared to placebo (risk ratio (RR) 1.72, 95% CI 1.10 to 2.69; 1 trial, 40 participants). Another trial reported very little difference in itch severity with NB-UVB (25 participants, four weeks of treatment). The number of participants with moderate to greater global improvement may be higher with NB-UVB than placebo after 12 weeks of treatment (RR 2.81, 95% CI 1.10 to 7.17; 1 trial, 41 participants). NB-UVB may not affect rates of withdrawal due to adverse events. No withdrawals were reported in one trial of NB-UVB versus placebo (18 participants, nine weeks of treatment). In two trials of NB-UVB versus no treatment, each reported one withdrawal per group (71 participants, 8 to 12 weeks of treatment). We judged that all reported outcomes were supported with low-certainty evidence, due to risk of bias and imprecision. No trials reported HRQoL. NB-UVB versus UVA1 We judged the evidence for NB-UVB compared to UVA1 to be very low certainty for all outcomes, due to risk of bias and imprecision. There was no evidence of a difference in physician-assessed signs after six weeks (MD -2.00, 95% CI -8.41 to 4.41; 1 trial, 46 participants; scale: 0 to 108), or patient-reported itch after six weeks (MD 0.3, 95% CI -1.07 to 1.67; 1 trial, 46 participants; scale: 0 to 10). Two split-body trials (20 participants, 40 sides) also measured these outcomes, using different scales at seven to eight weeks; they reported lower scores with NB-UVB. One trial reported HRQoL at six weeks (MD 2.9, 95% CI -9.57 to 15.37; 1 trial, 46 participants; scale: 30 to 150). One split-body trial reported no withdrawals due to adverse events over 12 weeks (13 participants). No trials reported IGA. NB-UVB versus PUVA We judged the evidence for NB-UVB compared to PUVA (8-methoxypsoralen in bath plus UVA) to be very low certainty for all reported outcomes, due to risk of bias and imprecision. There was no evidence of a difference in physician-assessed signs after six weeks (64.1% reduction with NB-UVB versus 65.7% reduction with PUVA; 1 trial, 10 participants, 20 sides). There was no evidence of a difference in marked improvement or complete remission after six weeks (odds ratio (OR) 1.00, 95% CI 0.13 to 7.89; 1 trial, 9/10 participants with both treatments). One split-body trial reported no withdrawals due to adverse events in 10 participants over six weeks. The trials did not report patient-reported symptoms or HRQoL. UVA1 versus PUVA There was very low-certainty evidence, due to serious risk of bias and imprecision, that PUVA (oral 5-methoxypsoralen plus UVA) reduced physician-assessed signs more than UVA1 after three weeks (MD 11.3, 95% CI -0.21 to 22.81; 1 trial, 40 participants; scale: 0 to 103). The trial did not report patient-reported symptoms, IGA, HRQoL, or withdrawals due to adverse events. There were no eligible trials for the key comparisons of UVA1 or PUVA compared with no treatment. Adverse events Reported adverse events included low rates of phototoxic reaction, severe irritation, UV burn, bacterial superinfection, disease exacerbation, and eczema herpeticum., Authors' Conclusions: Compared to placebo or no treatment, NB-UVB may improve physician-rated signs, patient-reported symptoms, and IGA after 12 weeks, without a difference in withdrawal due to adverse events. Evidence for UVA1 compared to NB-UVB or PUVA, and NB-UVB compared to PUVA was very low certainty. More information is needed on the safety and effectiveness of all aspects of phototherapy for treating AE., (Copyright © 2021 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

The role of competencies in postgraduate dental education and training has been a major topic of interest in recent years. Concerns have been voiced from all sides of the profession about how the competence of trainees and the quality of training can be assured so that high standards of patient care can be maintained. A three year project which seeks to develop a competency-based assessment system for general professional training is underway which hopes to answer some of the concerns and provide an evidence-based system of assessment for the early postgraduate years. This paper looks at the reasoning behind the project, its aims, and the progress made to date.

TT virus (TTV) is a newly discovered DNA virus originally classified as a member of the Parvoviridae. TTV is transmitted by blood transfusion where it has been reported to be associated with mild post-transfusion hepatitis. TTV can cause persistent infection, and is widely distributed geographically; we recently reported extremely high prevalences of viraemia in individuals living in tropical countries (e.g. 74% in Papua New Guinea, 83% in Gambia; Prescott & Simmonds, New England Journal of Medicine 339, 776, 1998). In the current study we have compared nucleotide sequences from the N22 region of TTV (222 bases) detected in eight widely dispersed human populations. Some variants of TTV, previously classified as genotypes 1a, 1b and 2, were widely distributed throughout the world, while others, such as a novel subtype of type 1 in Papua New Guinea, were confined to a single geographical area. Five of the 122 sequences obtained in this study (from Gambia, Nigeria, Papua New Guinea, Brazil and Ecuador) could not be classified as types 1, 2 or 3, with the variant from Brazil displaying only 46-50% nucleotide (32-35% amino acid) sequence similarity to other variants. This study provides an indication of the extreme sequence diversity of TTV, a characteristic which is untypical of parvoviruses.

TT virus (TTV) is widely distributed, with high frequencies of viremia in South America, Central Africa, and Papua New Guinea. The incidence and timing of infection in children born in a rural area of the Democratic Republic of Congo was investigated. TTV viremia was detected in 61 (58%) of 105 women attending an antenatal clinic and in 36 (54%) of 68 infants. Most infants acquired the infection at >/=3 months postpartum. Surprisingly, TTV infection was detected in a large proportion of children with TTV-negative mothers (13 [43%] of 30). Nucleotide sequences of TTV-infected children were frequently epidemiologically unlinked to variants detected in the mother. These three aspects contrast with the maternal transmission of hepatitis G virus/GB virus C in this cohort and suggest an environmental source of TTV infection comparable to hepatitis A virus and other enterically transmitted infections.

The RNA genome of hepatitis C virus (HCV) displays extensive sequence variation, and consequently, the virus is classified into six major genotypes. The severity of disease and response to antiviral treatment are thought to be influenced by both viral and host-related factors, including age of aquisition, duration of infection, circulating virus load, and the genotype of infecting virus Many investigators have reported that infections with HCV type 1 are associated with an increase in the likelihood of progression to hepatocellular carcinoma (1-3), and with nonresponsiveness to interferon therapy when compared to genotypes 2 or 3 (reviewed in refs. 4,5) This discovery emphasizes the need for genotyping methods in current clinical practice, in providing a predictor of the outcome of treatment, and perhaps helping to target appropriate treatment to the most relevant patient groups.

Infection with hepatitis G virus (HGV) or GB virus-C (GBV-C) is widely distributed in human populations. Viruses related to GBV-C/HGV have been recovered from several New World primate species, including tamarins, owl monkeys and marmosets. To understand more about the relationship between GB viruses and their hosts, we used primers from the 5' non-coding (5'NC), non-structural 3 (NS3) and NS5 regions in nested polymerase chain reactions to screen for related viruses infecting non-captive chimpanzees (Pan troglodytes, troglodytes and verus subspecies). Sequences from the 5'NCR and NS5 regions were amplified from samples taken from 3 of 39 chimpanzees, and from one chimpanzee in the NS3 region. Sequence comparisons of each region revealed that the GB virus infecting chimpanzees was distinct from both GBV-C/HGV and from any of the known GBV-A sequences, but was more closely related to human viruses. GB viruses recovered from different chimpanzees were more diverse than variants of GBV-C/HGV found in humans, with 25% sequence divergence in the 5'NCR and 20% (9.5% amino acid) sequence divergence in NS5 between variants recovered from the troglodytes and verus subspecies, compared with 7.4% and 10.4% (1.9% amino acid) divergence amongst GBV-C/HGV variants infecting humans. Finding GBV-C/HGV-related viruses in an Old World monkey species suggests that GB-like viruses may be widely distributed in simians, and suggests a close evolutionary relationship with their natural hosts.

Background: A newly discovered DNA virus, transfusion-transmitted virus (TTV), has been implicated as a cause of post-transfusion hepatitis. We investigated the frequency of TTV viraemia in UK blood donors, and the extent to which TTV contaminates blood products such as factor VIII and IX clotting factors. We also investigated the possible aetiological role of TTV in cryptogenic fulminant hepatic failure (FHF)., Methods: We extracted DNA from plasma of blood donors and patients with FHF, and from blood products (factor VIII and IX clotting-factor concentrates, immunoglobulin preparations). We detected TTV by PCR using primers from a conserved region in the TTV genome., Findings: TTV viraemia was detected in 19 (1.9%) of 1000 non-remunerated regular blood donors. Infection occurred more frequently in older donors (mean age 53 years), compared with the age prolife of donors infected with hepatitis C virus and other parenterally-transmitted viruses. TTV contamination was found in ten (56%) of 18 batches of factor VIII and IX concentrate manufactured from such non-remunerated donors, and in seven (44%) of 16 batches of commercially available products. Whereas solvent or detergent treatment had little effect on the detection of TTV in factor VIII and IX by PCR, this virucidal step seemed to inactivate TTV infectivity. TTV infection was detected in four (19%) of 21 patients with FHF; in three cases, infection was detected at the onset of disease and could thus not be excluded from its aetiology., Interpretation: TTV viraemia is frequent in the blood-donor population, and transmission of TTV through transfusion of blood components may have occurred extensively. Clinical assessment of infected donors and recipients of blood and blood products, and assessment of TTV's aetiological role in hepatic and extra-hepatic disease, are urgently needed.

Assays that detect antibody to hepatitis C virus (HCV) are used to screen blood donors and patients with hepatitis. Current enzyme-linked immunosorbent assay (ELISA)-based methods are invariably based upon antigens from expressed recombinant proteins or oligopeptides from HCV type 1. Some HCV antigens used in screening assays are coded by regions of the HCV genome that show extensive variability; therefore, HCV type 1-based assays may be less effective for the detection of antibody elicited by infection with other genotypes. In this study, we have measured antibody reactivity of sera from 110 hepatitis C patients infected with type 1b, 3a, or 4a to genotype-specific and cross-reactive epitopes present in recombinant proteins from HCV genotypes 1b (core, NS3, and NS5), 3a (NS3, NS5), and 4a (core, NS3), corresponding to those used in current third-generation screening ELISAs. By comparing the serological reactivities of sera to type-homologous and type-heterologous antigens, we detected a significant type-specific component to the reactivity to NS3 (61 to 77% of the total reactivity) and NS5 (60% of the total reactivity). Furthermore, despite the similarities in the amino acid sequences of the core antigens of type 1b and type 4a, we also found significantly greater reactivity to type-homologous antigens, with approximately 25% of reactivity being type specific. These findings are consistent with previous findings of fivefold weaker reactivity of sera from HCV type 2- and HCV type 3-infected blood donors in the currently used third-generation ELISAs and suggest that these assays are suboptimal for screening populations in which the predominant genotype is not type 1.

Methods for identifying the genotype of hepatitis C virus (HCV) in clinical specimens are frequently based upon the direct characterisation of viral RNA sequences by polymerase chain reaction (PCR) amplification, or by serologically based methods, in which the infecting genotype is inferred from the pattern of antibody reactivity to type-specific peptides or recombinant proteins used as antigens in an Enzyme Linked Immunosorbent Assay (ELISA). Although genotyping by direct, PCR-based methods show generally highly concordant results with the genotype inferred from serological typing assays (> 95% agreement), there exist a small number of samples that produce discrepant results. To investigate the underlying reasons for the discrepancies, we obtained eleven samples from haemophiliacs and four samples from patients with chronic hepatitis C that produced discordant results between a PCR based assay (InnoLipa I and II) and a serotyping assay (Murex HC02). Nucleotide sequences in the 5'noncoding region (5'NCR), core, and NS4 region were used to identify the genotype of the circulating virus and to identify amino acid changes in NS4 that might alter antigenicity. In 14 samples, sequence analysis of all three regions was concordant with the results of the InnoLipa assay. There were few if any amino acid substitutions in NS4 that might have accounted for the discrepant serotyping results, which were found predominantly in samples from individuals with a history of multiple exposure to HCV. It remains unclear whether the detection of antibody in such discrepant samples corresponds to previous expression of a different genotype than detected by PCR, or whether the virus population in plasma is more restricted in genotype diversity than the population in the liver or at other sites of viral replication.

Patients with chronic hepatitis C respond differently when treated with interferon. We randomized 116 patients with chronic hepatitis C in order to compare two dosage regimens of recombinant interferon alpha 2a:3 MIU x 3 per week for 6 months (arm A) or 6 MIU x 3 per week for 3 months and then 3 MIU x 3 per week for 3 months (arm B). There were no significant differences concerning outcome between the two dose regimens: sustained clearance of HCV viremia 6 months after the end of treatment was obtained in 12/59 (20%) in group A compared with 18/57 (32%) in group B (p = 0.24). In patients with genotype 1a, 4/31 (13%), in genotype 1b, none of 9 (0%), 9/15 (60%) in genotype 2, and 17/58 (29%) in genotype 3, showed sustained clearance of HCV viremia 6 months after the end of treatment (p = 0.002). In a stepwise logistic regression analysis, only pretreatment viral load (p = 0.0001), genotype (p = 0.001) and age (p = 0.04) were identified as independent predictors of sustained clearance of HCV viremia. Liver histology as assessed by Knodell index was significantly improved in patients with sustained HCV RNA response 6 months after the end of treatment (5.2 +/- 2.2 vs 2.6 +/- 2.2, p < 0.001), but not in responders with relapse or in non-responders. In conclusion, stepwise logistic regression analysis showed that viral load, HCV genotype and age were the only independent predictors for sustained HCV RNA response.

The genotype distribution of hepatitis C virus (HCV) was investigated in 212 viraemic blood donors from Hong Kong. A subset of the samples was investigated using three different genotyping assays to establish the accuracy of each in this population. These assays were restriction fragment length polymorphism (RFLP) of amplified 5' noncoding region (5'NCR) sequences, RFLP of the core region, and a serotyping assay using peptides from two antigenic regions of NS4. Genotypes detected in Hong Kong blood donors were 1a (6.2%), 1b (58.8%), 2a (1.4%), 2b (1.4%), 3a (1.9%), and 6a (27.0%). All genotyping assays produced concordant results. No evidence was obtained for the presence of type 6 group variants recently identified in Southeast Asia, other than type 6a. A serotyping assay based upon the detection of type-specific antibody to epitopes in NS4 produced similar results to the genotyping assays (98% concordance), but a reduced sensitivity (75%) compared with genotyping methods. Sequence variation in NS4 was not the cause of the reduced rate of detection of type 6 antibody in this population. Eighty-four percent donors infected with type 6a were male, compared to 75% donors infected with type 1b. The median alanine transaminase (ALT) level in type 6 infected donors was lower than in type 1b, (43.8 and 51.1 U/l, respectively) although these values were not statistically significant (P = 0.094). There was no significant difference between the ages of donors infected with types 1b and 6a. Risk factors for HCV infection in the blood donors included blood transfusion, intravenous drug abuse, and tattooing. A significantly greater number of donors infected with HCV-6a reported a history of drug abuse (66%) than donors infected with HCV-1b (7%).

HCV antibody screening of 624,910 blood donations resulted in 3,832 samples being referred for confirmation. All were tested by RIBA-3 with 2,710 negative, 945 indeterminate and 177 positive results. HCV RNA was detected by PCR in an average of 69.5% of RIBA-3 positives (4 bands 84.1%; 3 bands 74.1%; 2 bands 34.1%) and only 0.53% of RIBA-3 indeterminates. Eighty-four percent of samples with a total RIBA-3 band intensity score (maximum 16) of > or = 8 were PCR positive compared with only 22% of those with a score of < 8. Total mean band intensities for HCV genotype 1 samples (n = 65) were 13.2, genotype 2 (n = 17) 11.4 and genotype 3 (n = 65) 11.2 with type 1 samples showing greater reactivity with c100 and c33 antibodies. No PCR positive type 1 samples were found with RIBA-3 total band scores less than 8, no PCR positive type 2 samples less than 6, whilst PCR positive type 3 samples were found with scores as low as 2. NS5 indeterminates were the most common (40.2%) single band pattern but yielded no PCR positive samples, followed by c33 (23.3%) with one PCR positive and c100 (20.2%) with one PCR positive whilst c22 indeterminates were least common (16.3%) but included three PCR positive donors. All five RIBA-3 indeterminate PCR positive donors were type 3.

Objective: To 1) verify the validity of a new line probe assay for hepatitis C virus (HCV) genotyping and 2) determine the distribution of HCV genotypes and the association between HCV genotype and clinical variables in patients with chronic hepatitis C seen in tertiary referral centers in the United States., Design: Retrospective cross-sectional analysis., Patients: 438 patients with chronic hepatitis C from 10 tertiary referral centers., Measurements: The validity of the line probe assay was first verified against a panel of serum specimens that had previously been characterized by six different HCV genotyping methods. Specimens from all 438 patients were then genotyped using this line probe assay. The associations between HCV genotype and clinical variables were examined using analysis of variance. Pairwise testing was used when the F test showed a statistically significant difference. Nonparametric alternatives were used for variables for which normality could not be assumed., Results: The line probe assay was quick and reproducible, and it showed good concordance with other tests. In our sample, the proportions of patients with HCV types 1, 2, 3, and 4 were 71.5%, 13.5%, 5.5%, and 1.1%, respectively. Subtypes 1a and 1b were seen in approximately equal proportions of patients with HCV type 1. Mixed infection was detected in 3.7% of specimens, and 4.8% of specimens either had negative results on polymerase chain reaction or could not be typed. A higher proportion of patients with HCV type 1 than of patients with HCV-type 1 had acquired HCV through transfusion of blood products (50% compared with 25%; P < 0.001). Patients with HCV type 1 also had a longer estimated duration of infection compared with patients with HCV type 3 (P = 0.004) and type 4 (P = 0.049). Disease activity did not differ among patients infected with HCV types 1, 2, or 3. Levels of viremia were similar in patients with HCV types 1, 2, or 3, but patients with HCV type 4 had a lower level of viremia than did patients with HCV type 1 (P = 0.047)., Conclusions: The line probe assay can be used in patients with chronic HCV infection in the United States. In patients with chronic hepatitis C referred to tertiary centers in the United States, type 1 is the most common HCV genotype. Disease activity and viremia levels do not differ among patients chronically infected with HCV types 1, 2, or 3.

Detection of antibody to recombinant proteins derived from hepatitis C virus (HCV) genotype 1 represents the principal method for diagnosis of HCV infection. A method was developed for quantifying antibody reactivity in two third-generation enzyme immunoassays (Ortho EIA 3.0 and Murex VK48), and the influence of viraemia, HCV genotype, and host factors such as age, gender, and risk group upon antibody levels were investigated in a consecutive series of 117 anti-HCV-positive volunteer blood donors. Viraemic donors (as assessed by the polymerase chain reaction; PCR) showed significantly higher levels of anti-HCV by the Ortho EIA than those who were nonviraemic (adjusted mean difference of 10.1 fold after multiple regression analysis). The only other factor to influence significantly antibody level was genotype, where it was found that donors infected with type 1 showed 4 to 4.5 times greater serological reactivity by the Ortho assay than those infected with type 2 or 3. Antibody levels by the Ortho assay correlated closely to those detected by the Murex VK48 assay, and similar differences between PCR-positive and negative donors and between those infected with different genotypes were found. Differences in serological reactivity between genotypes indicate that a large proportion of epitopes of the type 1a or 1b recombinant proteins used in current assays are genotype specific. Variation in sensitivity of screening assays for different genotypes is of potential concern when used in countries where non-type 1 genotypes predominate in the blood donor or patient population.

Previous surveys of the prevalences of genotypes of hepatitis C virus (HCV) in different populations have often used genotyping assays based upon analysis of amplified sequences from the 5' noncoding region (5'NCR), such as restriction fragment length polymorphism (RFLP) or hybridization with type-specific probes (e.g., InnoLipa). Although highly conserved, this region contains several type-specific nucleotide polymorphisms that allow major genotypes 1 to 6 to be reliably identified. Recently, however, novel HCV variants found in Vietnam and Thailand that are distantly related to the type 6a genotype (type 6 group) by phylogenetic analysis of coding regions of the genome often have sequences in the 5'NCR that are similar or identical to those of type 1 and could therefore not be identified by an assay of sequences in this region. We developed a new genotyping assay based upon RFLP of sequences amplified from the more variable core region to investigate their distribution elsewhere in southeast (SE) Asia. Among 108 samples from blood donors in seven areas that were identified as type 1 by RFLP in the 5'NCR, type 6 group variants were found in Thailand (7 from 28 samples originally identified as type 1) and Burma (Myanmar) (1 of 3) but were not found in Hong Kong (n = 43), Macau (n = 8), Taiwan (n = 6), Singapore (n = 2), or Malaysia (n = 18). Although this small survey suggests a relatively limited distribution for type 6 group variants in SE Asia, larger studies will be required to explore their distribution in other geographical regions and the extent to which their presence would limit the practical usefulness of 5'NCR-based genotyping assays for clinical or epidemiological purposes.

The usefulness of identification of hepatitis C virus (HCV) genotype has recently been investigated for the clinical management of patients infected by HCV. In the present study, the HCV genotype infecting 127 patients was determined by two different methods: HCV genotyping using a dot-blot assay with type-specific probes derived from the 5'-UTR of HCV genome and HCV serotyping using an ELISA system in which type-specific antibodies against the NS4 region were detected. Overall, a good correlation of the two methods was observed, the main discrepancy being 4 patients with sequence-confirmed HCV-2 (2 cases) and HCV-3 (2 cases) genotypes recognized as HCV-1 by serotyping. Mixed infections were not detected by either method. In 19 PCR negative sera, in which the HCV genotype could not be evaluated, no particular serotype profile was observed. In conclusion, the molecular and serological techniques are almost equivalent in determining the viral type, although in individual cases, especially in PCR negative patients, the clinical meaning of the serotyping result remains to be determined.

The 5' end of the NS-4 protein of different genotypes of hepatitis C virus (HCV) is highly variable in nucleotide and inferred amino acid sequence, with frequent predicted amino acid substitutions between all six of the major HCV genotypes described to date. This region has been shown to be antigenic by epitope mapping, and elicits antibody in HCV-infected individuals with a detectable type-specific component. We have used this sequence data to specify branched peptides for an indirect binding/competition assay to detect type-specific antibody to each major genotype. A total of 183 out of 210 samples (87%) from blood donors and patients with chronic hepatitis C infected with genotypes 1 to 6 showed detectable type-specific antibody to NS-4 peptides that in almost all cases (> 97 %) corresponded to the genotype detected by a PCR typing method. These findings demonstrate the existence of major antigenic differences between genotypes of HCV, and indicate how infection with different variants of HCV may be detected by a serological test.

Serum samples from 139 US patients with chronic hepatitis C virus (HCV) infection were studied using six different genotyping systems, including both molecular and serologic methods, to determine the applicability of these approaches and the prevalence of various HCV subtypes. The concordance of genotyping results based on the various systems (except for core polymerase chain reaction genotyping) was good (93.5%). Subtypes 1a and 1b were prevalent (37.4%). Subtypes 2a (2.2%), 2b (8.6%), and 3a (5.8%) were less common. HCV genotypes could not be determined in 3.4%-16.5% of samples depending on the method used. HCV type 2 was associated with greater histologic activity but lower serum HCV RNA levels (P < .05), whereas type 3 was associated with lower serum alanine aminotransferase levels (P < .05). These data demonstrate a high concordance between HCV genotyping systems and provide a foundation for comparison of genotyping data between studies using different systems. HCV types 1a and 1b are both prevalent in the United States.

In a controlled study using mexiletine and placebo, the incidence of ventricular arrhythmias after acute myocardial infarction (AMI) has been compared. The study covered 40 male patients who had sustained AMI and who in the first 48 h after onset of infarction had exhibited ventricular tachycardia, R on T-, multiform or close-coupled ventricular ectopic beats. Half of the patients were given either mexiletine (250 mg 8-hourly) or placebo. On the 4th and 10th day after onset of infarction a continuous 24-hour ECG was performed. 76% of the patients receiving placebo showed serious ventricular arrhythmias compared with 32% receiving mexiletine (p less than 0.05). These results demonstrate (1) the frequency of ventricular arrhythmias in a group of patients already at risk, and (2) the efficacy of an oral antiarrhythmic agent like mexiletine in the management of these rhythm disorders.