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Biomedical subjects

D C Shanson

Publications and source records attributed to D C Shanson.

At least 55 records · Page 3Linked to original sources
PubMed1989

Transmission of human immunodeficiency virus by heterosexual contact with reference to antenatal screening.

Twenty-seven women all of childbearing age, eight of whom were pregnant, were identified as human immunodeficiency virus (HIV-1) antibody positive in the genitourinary medicine clinics of East Riverside up to March 1987. Of these 27 women 11 had acquired the virus by heterosexual contact. Between 1 March 1987 and 29 February 1988, all 1328 women attending the antenatal clinic were offered an HIV screening test, 982 accepted and the other 346 declined to be tested. Two of the 982 tested women were found to be HIV-1 antibody positive. Two other pregnant HIV-1-positive women were identified during this time, one was tested in the genitourinary medicine clinic and the other whilst an in-patient for drug withdrawal. All except one of the 12 HIV-1-antibody-positive pregnant women were in known high-risk groups. In addition up to March 1988, 32 heterosexual men were identified as HIV-1 antibody positive and 22 of these were intravenous drug abusers. If the present trend continues, more women will become infected, often unaware that they are at risk and this may not be detected unless HIV testing is offered to all pregnant women and widely accepted. Decisions on local policy should be based on the available estimates of prevalence of HIV infection in that community.

Adult↗
PubMed1989

Clinical, immunological, and virological effects of sodium fusidate in patients with AIDS or AIDS-related complex (ARC): an open study.

Fusidic acid has previously been noted to prevent syncytial formation by human immunodeficiency virus (HIV) in vitro. Since this drug is a cheap, usually well-tolerated substance with known toxicity profile, an open, uncontrolled trial was undertaken to evaluate its possible efficacy in HIV disease. Twenty HIV antibody positive patients (10 with AIDS and 10 with ARC) were treated with sodium fusidate 500 mg every 8 h for up to 3 months. One patient died during therapy and six ceased treatment due to adverse events. Rash, nausea, diarrhea, and/or abdominal pain caused difficulties in all patients. There was no significant improvement in clinical state or T-helper cell levels, and no observed decrease in HIV p24 antigen during treatment. We conclude that in this open trial, sodium fusidate had no observable beneficial clinical, virological, or immunological effects.

AIDS-Related Complex↗
PubMed1988

Serological studies on health care workers caring for patients with human immunodeficiency virus.

Between 1982 and July 1987, more than 1200 patients attending St Stephen's Hospital were found to be HIV antibody positive. Four hundred were inpatients and most of the outpatients attended the sexually transmitted disease clinic. Two hundred and twenty-one patients had AIDS, 480 HIV-related disorders and 500 were asymptomatic. Most inpatients had invasive procedures within the operating theatres and there were 25 postmortems. Four hundred and five antibody tests from 220 health care workers from the STD clinic, operating theatres, isolation ward, intensive care unit and clinical laboratories were voluntarily tested for HIV antibody by an ELISA screening method. All were negative, except one male nurse who had other risk factors. Twenty-nine staff suffered needlestick injury with blood of HIV antibody positive patients; none has developed serological evidence of HIV infection.

AIDS Serodiagnosis↗
PubMed1988

Controversies about guidelines to prevent the transmission of human immunodeficiency virus in hospitals in Britain.

The widespread screening of donors of blood, organs and semen for HIV antibody has contributed greatly to the prevention of spread of HIV to patients in British hospitals. The chances of patients acquiring HIV from a contaminated blood transfusion are now estimated at less than 1 in 1 million and factor VIII for haemophiliacs, which is also heat treated, is now virtually always free of HIV contamination. However, the wider use of HIV antibody tests to identify infected patients and rationalize the application of additional 'inoculation risk' precautions, so as to protect staff, is controversial. The risks of hospital staff acquiring HIV following occupational exposure, without such a screening-programme, are extremely low provided a high standard of hygiene is maintained and inoculation injuries are avoided. When needlestick injuries occur, involving HIV infected patients, the chances of transmission of HIV to hospital staff are less than 1 in 100. Current guidelines in Britain depend on use of additional inoculation precautions for patients belonging to HIV risk groups but in practice most of these 'risk patients' are not infected with HIV. Screening HIV antibody tests, preferably with consent, can help the smooth running of operating theatres in areas where many 'risk patients' require surgery, as extra precautions are not necessary for most of these patients who are HIV negative. All antenatal patients should be screened especially in areas of high prevalence of HIV, as this helps to prevent vertical transmission as well as facilitating the rational use of extra precautions to protect health care workers.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The microbial causes of diarrhoea in patients infected with the human immunodeficiency virus.

Diarrhoea is common in patients infected with the human immunodeficiency virus (HIV). We sought the cause of diarrhoea in all HIV antibody-positive patients with diarrhoea who presented at St Stephen's Hospital, London over a period of 15 months. Altogether, 441 specimens from 179 patients were examined. Infective causes were found in 86 (48%) patients. Protozoa were the most common infecting organisms (30% patients). Of these, Cryptosporidium sp. was the most frequent (9.5% patients), followed by Entamoeba histolytica and Giarda lamblia. 'Non-pathogenic' protozoa (NPP) were also common (15% patients), often in the absence of generally recognised pathogens. A case controlled study failed to show a significant difference in the rate of isolation of NPP in HIV antibody-positive patients with diarrhoea compared with HIV antibody-positive patients without diarrhoea. Bacterial causes of diarrhoea were found as follows: Salmonella spp., Campylobacter spp. and Shigella sonnei; Mycobacterium avium-intracellulare (MAI) was isolated from the faeces of eight (4.5%) patients. Isolation of MAI from faeces was associated with disseminated MAI infection. This study has shown that two commonly isolated pathogens, namely Cryptosporidium sp. and MAI, can be identified quickly and reliably by the same modified Ziehl-Neelson staining of concentrated faeces.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Disseminated Mycobacterium avium-intracellulare infection and red cell hypoplasia in patients with the acquired immune deficiency syndrome.

During a period of 14 months in 1985 and 1986, infection with Mycobacterium avium-intracellulare (MAI) complex was diagnosed in 10 of 76 patients with Human Immunodeficiency Virus (HIV)-associated infection. In eight of the 10 patients, the infection was disseminated. All eight patients were anaemic. A bone marrow aspirate and/or trephine biopsy performed in six of them revealed evidence of red cell hypoplasia. MAI was cultured from all six samples of bone marrow. The strains of MAI isolated were resistant to conventional antituberculous drugs but were susceptible in vitro to ansamycin, ethionamide and cycloserine. None of the eight patients responded clinically to antituberculous therapy. The eight anaemic patients had pronounced constitutional symptoms. We suggest that severe anaemia and constitutional symptoms in patients with HIV-associated disease should prompt a search for evidence of disseminated MAI infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Cryptosporidial diarrhoea in AIDS and its treatment.

Of 234 patients with AIDS diagnosed at St. Stephen's Hospital between January 1981 and June 1987, 26 (11%) were found to have cryptosporidiosis. Stool examination was positive in all patients, but an average of three specimens (range 1-6) were required before a positive diagnosis was made. Other methods of diagnosis included jejunal and rectal biopsy and aspiration of the duodenal contents. Twenty three (89%) lived for six months from the time of diagnosis and 16 (60%) were alive at one year. Only five patients died as a direct result of cryptosporidial infection, while 10 other patients died from another complication of AIDS. Fifteen patients were enrolled in a prospective controlled study of erythromycin or spiramycin in the treatment of cryptosporidial diarrhoea. Most patients showed a significant response to antibiotic therapy but treatment was limited because of side effects. All patients responded to antidiarrhoeal agents, particularly long acting morphine sulphate. Three of our patients recently given zidovudine (AZT) have responded with a cessation of diarrhoea and cryptosporidia are no longer isolated from the stools.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Comparison of methods for isolating Mycobacterium avium-intracellulare from blood of patients with AIDS.

A variety of blood culture media were compared to determine the optimal method for the isolation of Mycobacterium avium-intracellulare (MAI) from the blood of patients with AIDS. Simulated laboratory blood cultures and clinical blood cultures were tested. Glucose broth, Bactec aerobic medium, Kirschner's medium, and Bactec Middlebrook medium supported the growth of MAI. The Isolator system, a lysis centrifugation method, facilitated the most rapid isolation of MAI (p = 0.001). The Bactec Middlebrook medium gave the most rapid detection rate (p = 0.001) as acid fast bacilli could be stained by the Ziehl-Neelson method before colonies were isolated in the Isolator system. The growth index readings did not reliably predict mycobacterial growth in the two radiometric media tested. Although several methods may be used to isolate MAI from blood, the most rapid and sensitive method is the Isolator system used in combination with the Bactec Middlebrook medium.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Comparison of intravenous teicoplanin with intramuscular amoxycillin for the prophylaxis of streptococcal bacteraemia in dental patients.

Teicoplanin 400 mg, given as an intravenous bolus dose after induction of general anaesthesia, was highly effective in reducing the prevalence of streptococcal bacteraemia following dental extraction. Pulse rate and blood pressure monitoring did not show any adverse cardiovascular reactions after this dose which was extremely well tolerated. Blood samples were collected from adult patients for culture and antibiotic assay about two minutes after the dental procedure. Viridans streptococci were isolated from one of 40 patients receiving teicoplanin (2.5%) compared with 13 of 40 (32.5%) control patients. Another group of patients investigated received amoxycillin 1.0 g, intramuscularly shortly before anaesthesia, and viridans streptococci were isolated from 10 of 40 (25%) patients in this group. The mean serum teicoplanin and amoxycillin concentrations at the time of extraction were 37 and 10 mg/l respectively. Although amoxycillin was administered with lignocaine patients occasionally complained of pain following intramuscular injection. The results of this study suggest that the 400 mg intravenous bolus dose of teicoplanin is more suitable than 1.0 g intramuscular amoxycillin for the parenteral prophylaxis of streptococcal endocarditis in patients with cardiac lesions who require a dental procedure. Also as the teicoplanin dose is easy to administer and free of cardiovascular reactions or 'red man' syndrome it is probably more suitable than vancomycin for providing prophylaxis in patients allergic to penicillin.

Adult↗
PubMed1987

Antibiotic prophylaxis of infective endocarditis in the United Kingdom and Europe.

In the U.K. and Europe there are now simple oral chemoprophylaxis recommendations which are likely to be widely complied with by patients, dental and medical practitioners. The main recommendations of the 1982 BSAC Endocarditis Working Party report and the 1985 report of the European Society of Cardiology are similar and involve the administration of a single 3 g dose of oral amoxycillin 1 h before the procedure, or two doses of erythromycin for patients allergic to penicillin. Amoxycillin is more suitable than penicillin V for single dose chemoprophylaxis because of its higher and more persistent serum bactericidal concentrations and lower serum protein binding compared with penicillin V. Controversies about the precautions needed for patients with prosthetic valves are discussed. Erythromycin is associated with more frequent gastrointestinal side-effects and less reliable absorption than amoxycillin. None the less, recent studies suggest that the 1.5 g loading dose of oral erythromycin stearate has an 'immediate' effect in reducing post-extraction streptococcal bacteraemia and appears to be reasonably well tolerated by most adults. In 1986 a few changes have been suggested by the BSAC Endocarditis Working Party and concern the use of alternative oral amoxycillin regimens for patients requiring general anaesthesia, the giving of two administrations of amoxycillin within one month when prophylaxis is required for repeated dental procedures and the slower infusion of intravenous vancomycin to reduce the incidence of adverse reactions. A register of cases of failed chemoprophylaxis' has been started in the U.K. and also in Europe.

Amoxicillin↗
PubMed1987

Clinical evaluation of Abbott and Wellcome enzyme linked immunosorbent assays for detection of serum antibodies to human immunodeficiency virus (HIV).

Abbott and Wellcome enzyme linked immunosorbent assays (ELISAs) for detection of antibodies to human immunodeficiency virus (HIV) were compared in tests on 932 sera collected predominantly from male homosexuals attending a sexually transmitted disease (STD) clinic in central London. Two hundred and twenty three sera had HIV antibodies detected by both types of assay, with confirmation of the results by further tests carried out at the Virus Reference Laboratory (VRL) in Colindale. There was a 97.3% correlation between the results obtained by the two commercial ELISA assays on the tests carried out on unheated sera. The Abbott ELISA gave significantly more false positive results than the Wellcome test when the manufacturer's instructions for cut off values were followed. There was one false negative Abbott results: it failed to react to repeated Abbott ELISA but was positive by Wellcome and confirmatory assays. Of 283 heat treated sera 14.8% gave falsely reactive results with the Abbott assay whereas there were no differences between heated and unheated sera with the Wellcome assay. VRL or Western blot confirmatory assays, or both, confirmed all the 235 positive results obtained with the Wellcome assay.

Antibodies, Viral↗
PubMed1986

Clinical investigations of lymphadenopathy, including lymph node biopsies, in 24 homosexual men with antibodies to the human T-cell lymphotropic virus type III (HTLV-III).

The findings of 27 lymph node biopsies performed on 24 homosexual patients with lymphadenopathy are presented. Six had acquired immune deficiency syndrome (AIDS) and 18 lymphadenopathy only, of whom one subsequently developed AIDS. All these patients had antibodies to the human T-cell lymphotropic virus type III (HTLV-III) suggesting that HTLV-III is currently the commonest cause of lymphadenopathy in homosexual men. The histopathological findings of six of seven nodes from AIDS patients showed either follicular depletion alone or follicular and paracortical lymphocyte depletion. Nodes from four patients showed Kaposi's sarcoma, three of which also showed follicular hyperplasia. In two of these patients there were no cutaneous manifestations of this condition. One lymph node from a patient with persistent generalized lymphadenopathy (PGL) showed Mycobacterium tuberculosis. Six nodes from six other patients have had features of toxoplasmosis although there was no serological or clinical evidence of recent toxoplasma infection. The remaining 11 lymph nodes from patients with PGL and one node from a patient with transient lymphadenopathy, showed reactive follicular hyperplasia only. We conclude that homosexuals with lymphadenopathy who are HTLV-III antibody positive do not need a routine node biopsy unless an alternative diagnosis is strongly suspected.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Activity of teicoplanin compared with vancomycin alone, and combined with gentamicin, against penicillin tolerant viridans streptococci and enterococci causing endocarditis.

Teicoplanin had greater inhibitory activity than vancomycin against most of 22 penicillin tolerant strains of streptococci, but both drugs failed to kill 99.9% of the inoculum when tested alone at concentrations less than 16mg 1(-1). Bactericidal synergy between teicoplanin combined with gentamicin and vancomycin combined with gentamicin was always demonstrated in further tests with 16 penicillin tolerant strains. Teicoplanin had greater bactericidal activity than vancomycin against five of seven strains of viridans streptococci and five of nine strains of enterococci in MBC experiments, where each drug was combined with gentamicin. Killing curve experiments with five penicillin tolerant streptococci showed teicoplanin and vancomycin to have similar bactericidal activity within 24 h when tested at 5 mg 1(-1) with 2 mg 1(-1) gentamicin. However, at 0.5 mg 1(-1) only teicoplanin had a bactericidal synergic effect with gentamicin.

Anti-Bacterial Agents↗
PubMed1986

Bactericidal activity of netilmicin compared with gentamicin and streptomycin, alone and in combination with penicillin, against penicillin tolerant viridans streptococci and enterococci.

Netilmicin was compared with gentamicin and streptomycin for in-vitro activity against 30 strains of penicillin-tolerant streptococci including 16 strains of enterococci. Both netilmicin and gentamicin tested alone at 4 mg/l caused 99.9% kill of more than half of the 13 strains of viridans streptococci tested, whereas streptomycin, 4 mg/l, had no bactericidal effect against these strains. Netilmicin, gentamicin and streptomycin tested alone at 8.0 mg/l against 10 strains of Streptococcus faecalis resulted in 99.9% kill of six, one and zero strains respectively. Combinations of penicillin with 2 mg/l of either netilmicin or gentamicin resulted in bactericidal synergy against 12 of 13 strains of viridans streptococci and all 10 strains of S. faecalis after 18 to 24 h incubation. Parallel experiments showed that higher concentration of penicillin were required to obtain 99.9% kill of 10 streptococcal strains when 4 mg/l streptomycin was compared with 2 mg/l of the other aminoglycosides. Killing curves showed similar bactericidal synergy for netilmicin-penicillin and gentamicin-penicillin combinations against most streptococci tested after 24 h incubation but there was sometimes a greater bactericidal effect noted with netilmicin after only 6 h incubation of the broth or after 48 h incubation. The results of this in-vitro study suggest that netilmicin is at least as effective as gentamicin as a bactericidal synergic agent with penicillin against penicillin-tolerant viridans streptococci and S. faecalis strains isolated from patients with endocarditis. Neither gentamicin or netilmicin were effective as bactericidal synergic agents with penicillin against 4 of 6 strains of S. faecium tested.

Drug Synergism↗
PubMed1986

Staphylococcal infections in hospital.

Staphylococcus aureus is a major cause of surgical sepsis and septicaemia. The prevention and control of outbreaks of hospital infection caused by methicillin-resistant strains has become increasingly important in recent years. Staph. epidermidis has also emerged as a "problem organism" often causing serious infection in patients with prosthetic implants.

Catheters, Indwelling↗