An open study of interferon in HIV-antibody-positive men.

Alpha-2a-recombinant interferon (Roferon A) was given subcutaneously in a dose of 3 mega units twice weekly for 15-18 months to 14 HIV-antibody-positive, p24-antigen-negative men with minimal HIV-related disease. Interferon was well-tolerated and safe. Although there was either improvement or lack of deterioration initially in 22 out of 26 HIV disease markers, including lymphadenopathy, thrombocytopenic purpura and nail fungal infection, there were 11 instances of HIV disease indicators appearing during the study. At 15 months, six patients were withdrawn from the study because of clinical and immunological deterioration.

An algorithm for confirming screen reactivity in blood donors in enzyme immunoassays for antibodies to hepatitis C virus.

Three commercial second generation enzyme immunoassays (EIA) and a second generation immunoblot assay (RIBA-II) for detecting antibodies to hepatitis C virus (HCV) were evaluated in a study of confirmatory testing using sera referred by six Regional Blood Transfusion Centres (RTC). Of a total of 490 samples, 203 were negative in the same EIA as that used by the RTC and of these 162 were negative in all three EIAs. The RIBA-II immunoblot test was performed on all samples and 359 were negative, 69 were indeterminate and 62 reactive. We found a close relationship between RIBA-II reactivity, the reactivity of a sample in all three EIAs and the mean of the test/cut-off ratios of all three EIAs performed on that sample. When this was evaluated by PCR for HCV RNA, we found an association between the mean test/cut-off ratio and the probability that an immunoblot reactive or indeterminate sample was PCR positive. A mean ratio of greater than 5.0 in a RIBA-II reactive sample was associated with a 100% probability (16/16 tested) of being PCR positive. These observations should be extended by testing RIBA-II negative samples by PCR so that simplified algorithms for anti-HCV testing can be developed.

Food borne infection by a Norwalk like virus (small round structured virus).

Two outbreaks of gastrointestinal illness with identical symptoms occurred in parties attending banquets on consecutive evenings at a large hotel. The illness was typical of epidemic winter vomiting disease. Small round structured viruses resembling those seen in the Norwalk Ohio outbreak were identified by electron microscopy in stools of victims from one episode. One food handler was found to be excreting the virus, and there was evidence of a poor standard of hygiene in the kitchen. A food history analysis showed the illness to be significantly associated with eating cold cooked ham.

Enzyme-linked immunosorbent assay (ELISA) for the detection of hepatitis Be antigen and antibody: report of a field trial.

A field trial of an enzyme-linked immunosorbent assay (ELISA) for the detection of the hepatitis Be markers is reported. It is simple to perform, is designed to be read by eye and does not require any expensive apparatus. When compared with a commercially available RIA kit for the detection of the same markers, ELISA was shown to be as sensitive as RIA for the detection of anti-HBe but slightly less sensitive for the detection of HBeAg. However if all specimens negative for both HBeAg and anti-HBe by ELISA are considered to be potentially infectious, the ELISA should prove to be as useful as RIA for determining the "e" status of HBsAg-positive patients and, therefore, provide a reliable indication of the risk of secondary spread of hepatitis B infection to contacts by needle stick accident, close personal contact or perinatal transmission.

Report of a joint DMRQC/Organon field trial to detect hepatitis A IgM by ELISA.

The results of a field trial of a joint DMRQC/Organon ELISA kit for the detection of hepatitis A IgM antibody are reported. The participating laboratories were asked to use the kit to test a panel of 360 specimens consisting of duplicate coded samples of 180 sera. The panel was also tested by MACRIA in the Virus Reference Laboratory, Colindale. The ELISA was shown to be specific and sensitive giving good discrimination between acute and late convalescent hepatitis A sera. It was proposed that the same cut-off control as is used in the RIA (equivalent to 10 RIA units) should be adopted for the ELISA also.

Hepatitis C-related chronic liver disease among asymptomatic blood donors in the north west of England.

In the first 19 months of screening, the North Western Regional Transfusion Centre (RTC) tested 224,000 consecutive blood donors for antibody to hepatitis C virus (anti-HCV) by second generation enzyme immunoassay (EIA). Of these, 366 repeatedly reactive samples were referred for confirmatory testing at Manchester Public Health Laboratory (PHL). There, the initial EIA was repeated, together with two further EIAs. All the referred samples were subjected to a confirmatory line immunoblot (RIBA-II). Reverse transcription followed by the polymerase chain reaction (RT-PCR), in order to detect viral RNA, was performed on selected samples. Among the donors, 61 accepted offers for medical review and were assessed for risk factors, clinical findings and results of standard liver function tests. Of these donors, 53 proceeded to liver biopsy. The overall prevalence of confirmed positive donors was 0.04%. Main risk factors identified included intravenous drug abuse in 31 (51%) donors and prior blood transfusion in 12 (20%) but a risk factor was not apparent in 11 (18%). Viraemia, detected by RT-PCR, could be predicted with a high degree of accuracy by means of the readily available and simpler screening and confirmatory tests (EIA and RIBA-II). Established chronic hepatitis was demonstrated in 90% of the liver biopsies. A trend towards worsening histological findings accompanied increasing concentrations of serum transaminase. Even so, many donors with normal transaminase values had abnormal biopsies including those showing chronic active hepatitis (CAH). These findings indicate that a substantial proportion of previously unrecognised asymptomatic persons with established chronic liver disease exists among North Western blood donors.(ABSTRACT TRUNCATED AT 250 WORDS)

Oscillator mechanisms in the human motor system: investigating their properties using the aftercontraction effect.

It is proposed that the human motor system is organized to use hardware and/or software non-linear oscillator mechanisms, the output of these oscillators being responsible for driving the limbs via signals to muscle groups. Following earlier theoretical development, it is argued that these muscle groupings act as a unit and themselves are likely to behave as a non-linear system. The attributes of non-linear oscillators are many, and they are potentially significant for the explanation of motor behavior. This paper reviews and presents recent experiments that investigated the properties of muscular aftercontraction. The basic finding shows that subsequent to a period of moderate strain against a fixed surface the treated limb exhibits prolonged involuntary molar oscillations in the plane of the treatment. These results provide for the presence of driving oscillator mechanisms in the human motor apparatus. The mechanisms show generality of action in that directed attention can lead to oscillation of untreated limbs. Overall, the experiments showed that the movements exhibited the mutual interaction, synchronization, and preservation of phase relationships that are fundamental properties of non-linear oscillators. the picture that emerges is that these mechanisms can drive involuntary movements that are richly patterned: like slow versions of voluntary movements. The aftercontraction phenomenon proves to be an excellent tool for research on the oscillatory substrate of human motor organization.

The prevalence of Enterocytozoon bieneusi in acquired immunodeficiency syndrome (AIDS) patients from the north west of England: 1992-1995.

Microsporidia are increasingly being recognised as important enteric pathogens in patients with advanced human immunodeficiency virus (HIV) disease, i.e. acquired immunodeficiency syndrome (AIDS). The aims of this study were to investigate the frequency of detection of microsporidia associated with diarrhoea in patients with advanced HIV disease in the north west of England, and to determine the species involved and their prevalence. During the period from April 1992 to the end of December 1995, chronic diarrhoea in 88 patients in the late stage of HIV disease was investigated. Duodenal biopsies, duodenal aspirates or jejunal biopsies were received from 38 patients, and stool samples from 63 patients, as part of the routine investigation of possible causes of diarrhoea in these patients. Biopsies and aspirates were examined by thin-section electron microscopy (EM), and stool samples were examined by epi-fluorescence microscopy after staining with Calcofluor. Putative stool positives were confirmed by transmission electron microscopy. CD4-lymphocyte counts were available from all patients who provided samples. Nine out of 63 patients (14.3%) were found to be excreting microsporidial spores on stool examination. The species was confirmed as Enterocytozoon bieneusi. The mean CD4-lymphocyte count for this group was 37 x 10(6)/L (normal range 517-1677 x 10(6)/L). Three out of 38 biopsy specimens (7.9%) were also found to be infected with this microsporidian. The mean CD4-lymphocyte count for this group was 72 x 10(6)/L. Encephalitozoon intestinalis was not found in any samples examined. The prevalence of microsporidial infection in AIDS patients in the north west of England appears to be similar to that of patients in London, but less than that reported in studies from other developed countries.

HTLV-3 infection and AIDS: risk of spread by heterosexual contact.

PIP: This article reviews current research evidence on the natural history, epidemiology, and clinical features of acquired immunodeficiency disease (AIDS) and presents guidelines for controlling the sexual transmission of human lymphotropic virus type III (HTLV-III) infection. The rapid spread of HTLV-III infection through homosexual communities in the US and Europe and its association with promiscuity initially obscured the fact that heterosexual transmission is also a significant risk factor for infection. Public health workers and epidemiologists are examining which sexual practices are most associated with the transmission of HTLV-III infection. Case-control studies in homosexuals have suggested that promiscuity, passive anal intercourse, and other sexual practices associated with rectal trauma and bleeding correlate with infection. Similar studies involving heterosexuals have not been conducted. However, the following guidelines have been proposed for couples where 1 partner has been found to be positive for HTLV-III antibodies: 1) sexual partners should be confined to established relationships; 2) anal intercourse should be avoided, even if the male uses a condom; 3) no oral contact with semen should occur; 4) if vaginal intercourse is practiced, the use of condom is essential; and 5) the only practices that are free from risk of infection are mutual masturbation and hand caresses. Since a high proportion of children of women with HTLV-III develop severe immunodeficiency, it is undesirable for women who are HTLV-III antibody positive to become pregnant. Furthermore, there is evidence that women who are HTLV-III antibody positive are more likely to develop AIDS if they become pregnant. A reliable method of permanent or reversible contraception is recommended for these women. Finally, men who are antibody positive should not donate sperm to a sperm bank.^ieng

Reye's syndrome associated with acute tubular necrosis.

Two cases of Reye's syndrome, complicated by acute reversible renal failure, are presented. One case followed an influenza A virus infection.

An outbreak of hepatitis associated with intravenous injection of factor-VIII concentrate.

An outbreak of jaundice associated with three out of four batches of a commercial brand of freeze-dried factor-VIII concentrate occurred at the Bournemouth haemophilia centre between April and June, 1974. Seven cases of non-B hepatitis and four of hepatitis B occurred within 6 months of the first use of this product. Two patients contracted both types of hepatitis; thus nine patients became ill out of a total of twenty regularly seen at the centre, eighteen of whom received commercial factor-VIII concentrate.

A prospective study of cryoprecipitate administration: absence of evidence of virus infection.

In a prospective study of cryoprecipitate administration to patients who had never received large pool concentrates, no evidence of hepatitis or HIV infection was detected in a follow up period of one year. Following the introduction of screening of blood donors for anti-HIV in the UK in October 1985 the use of cryoprecipitate in selected cases should be reconsidered.

Commercial factor VIII associated hepatitis, 1974-75, in the United Kingdom: a retrospective survey.

A retrospective survey of transfusion hepatitis associated with a brand of commercial Factor VIII was carried out in 24 Haemophilia Centres from January 1974 until December 1975. Of 371 patients who were transfused with this product, and were followed up, 78 cases of hepatitis affecting 66 patients were found (17.7%). Two types of hepatitis were observed: hepatitis B and non-B hepatitis, the latter with an incubation period of between 8 and 60 days. Twelve patients contracted two types of hepatitis, non-B followed by hepatitis B. Only one patient died after contracting hepatitis B. Four of the suspect batches of concentrate were found to be positive for HBsAg by radioimmunoassay. There was evidence that the presence of hepatitis B surface antibody in a patient's serum prior to exposure was associated with immunity to hepatitis B. Evidence was presented suggesting that the non-B hepatitis observed was not due to hepatitis A. The factors affecting the incidence of transfusion hepatitis in haemophiliacs were discussed.