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Biomedical subjects

B Hirschel

Publications and source records attributed to B Hirschel.

At least 163 records · Page 9Linked to original sources

[Neurological complication of human immunodeficiency virus infection].

Neurological complications may occur even before immunosuppression is clinically observed, and can thus reveal HIV infection. Aseptic meningitis, subacute encephalitis, vacuolar myelopathy, inflammatory myopathy, and different types of polyneuropathies seem to be associated with HIV, but their pathogenesis has only recently begun to be understood. These complications must be distinguished from opportunistic infections and from intra-cerebral tumors with which they often coexist. The Sixth International Conference on AIDS in San Francisco has defined the extent and limits of our present knowledge, and has given new directions for research in this last, but not least important chapter of modern neurology.

Brain Neoplasms↗

Combined treatment with zidovudine and lymphoblast interferon-alpha in patients with HIV-related Kaposi's sarcoma.

A combination of oral zidovudine (250 mg twice daily) and subcutaneous interferon-alpha (10 x 10(6) units daily) was evaluated for clinical, antiretroviral, and immunological efficacy and for side effects in 17 patients with AIDS-related Kaposi's sarcoma. Fifteen patients were evaluable. During the study period of 12 weeks, tumor responses were complete in two patients and partial in two patients (27% major response rate). Minimal responses were seen in two patients (40% overall response rate). An anti-HIV effect (reduction of serum p24 antigen by 70% or more) was observed in seven of ten evaluable patients who were initially antigenemic. CD4 lymphocyte counts remained unchanged. In six patients who had either a tumor response or a marked decline of HIV antigenemia, the treatment was continued between 12 and 59 weeks beyond the study period. Two of four patients with tumor regression at 12 weeks had an additional tumor response in this period despite prior dose reduction of interferon due to toxicity. Late progression of KS was eventually observed in four of six patients on prolonged treatment. The responsiveness of Kaposi's sarcoma seen in this study in patients with low CD4 counts and prior constitutional symptoms (fever, weight loss) was unexpected and needs further confirmation by larger patient groups. Dose-limiting toxicities were bone marrow depression (severe anemia in four and neutropenia with anemia in two patients), subjective adverse experiences (fever, fatigue, myalgia; four patients) and both (two patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

A controlled study of inhaled pentamidine for primary prevention of Pneumocystis carinii pneumonia.

BACKGROUND: Current recommendations for prophylaxis of Pneumocystis carinii pneumonia (PCP) are based on data from patients who have had at least one episode of PCP (secondary prevention). We designed a study to determine the efficacy and side effects of inhaled pentamidine in the primary prevention of PCP. METHODS: Two hundred twenty-three patients sero-positive for human immunodeficiency virus (HIV) who had the acquired immunodeficiency syndrome (AIDS) but not PCP, who had advanced AIDS-related complex, or who had less than 0.2 x 10(9) CD4-positive lymphocytes per liter received either 300 mg of pentamidine isethionate or 300 mg of sodium isethionate every 28 days by inhaler. The proportion of patients surviving without PCP was analyzed with the log-rank test as a function of time spent in the trial, according to the intention to treat with either placebo or pentamidine. RESULTS: The third of five planned interim analyses showed a significant difference in the occurrence of PCP, with 8 cases in pentamidine group and 23 in the placebo group (nominal P value = 0.0021). There were no deaths within 60 days of the diagnosis of PCP and no significant differences in survival between groups. Approximately 53 inhalations were needed to prevent one episode of pneumonia. Thirty-eight of 114 patients given pentamidine (33 percent) and 7 of 109 given placebo (6 percent) had moderate-to-severe coughing during inhalations (two-tailed P less than 0.00001), which caused 4 patients given pentamidine (3.5 percent) to discontinue taking it. CONCLUSIONS: A dose of 300 mg of aerosolized pentamidine given every four weeks was well tolerated and 60 to 70 percent effective in preventing a first episode of PCP in patients with HIV infection.

AIDS-Related Complex↗

Absence of chronic human immunodeficiency virus infection without seroconversion in intravenous drug users: a prospective and retrospective study.

It has been reported that human immunodeficiency virus type 1 (HIV-1) infection may exist in persons without specific antibodies for years. To measure the frequency of a silent carrier state, a study was conducted in a cohort of 124 intravenous drug users (IVDUs) without anti-HIV-1 antibodies. All the participants had engaged in high-risk behavior for HIV-1 transmission for a number of years until 1987 or later. Samples were analyzed at 6-month intervals for the presence of HIV-1 provirus using DNA amplification and for the appearance of anti-HIV-1 antibodies. HIV-1 provirus and antibodies were undetectable in 122 participants, whereas seroconversion was observed in 2. In one of these, both amplified HIV-1 pol gene segment and anti-HIV-1 antibodies were detected simultaneously, and in the other, provirus was detected 1 month before seroconversion. This study suggests that long-term HIV-1 infection without anti-HIV-1 antibodies is rare and that repeated antibody testing is sufficient to determine the HIV-1 status of a person no longer at high risk for HIV-1 infection.

Adult↗

Neuro-otological manifestations in different stages of HIV infection.

A systematic investigation of the incidence and type of peripheral and central auditory and vestibular disorders occurring in different stages of HIV infection was performed: 43 HIV-seropositive patients (14 were symptomatic with manifestation of AIDS or related complex and 29 were clinically asymptomatic) were compared with a matched control group of 33 HIV-seronegative homosexual volunteers. Among the symptomatic patients 8 (57%) out of 14 and among the asymptomatic HIV-positive patients, 13 (45%) out of 29 had abnormal results in various audiological, vestibular and electrophysiological tests. Only minor anomalies were found in 4 (12%) of the 33 seronegative homosexuals. Our results indicate a high incidence of neuro-otological disorders among patients suffering from AIDS. The numerous electrophysiological abnormalities found in asymptomatic HIV-seropositive persons suggest furthermore an early subclinical involvement of the auditory and vestibular systems.

AIDS-Related Complex↗

[Prevention of infectious diseases in traveling].

Diarrhea, malaria, and viral hepatitis are among the preventable diseases of travellers. In Switzerland, almost all serious cases of malaria are introduced from tropical Africa; therefore, we recommend protection with 250 mg of mefloquin per week for this destination. Elsewhere, protection against mosquitoes, in combination with Fansimef for self-treatment, may be enough. For travellers' diarrhea, we prefer immediate treatment with ciprofloxacin or cotrimoxazol to prophylaxis. Administration of immune globulin against hepatitis A may be recommended for all non-immune tourists, whereas protection against hepatitis B is necessary for health workers and sex tourists.

Communicable Disease Control↗

[AIDS and gastrointestinal tract: a summary for gastroenterologists and surgeons].

The majority of patients with Aids suffer from diarrhea and weight loss, as well as opportunistic infection and tumors of the gastrointestinal tract; endoscopy is frequently necessary. Often, but not always, it is possible to identify an opportunistic tumor or infection which explains the patient's signs and symptoms. In other cases, HIV may itself be pathogenic. The most important opportunistic pathogens are Candida albicans (stomatitis and esophagitis), cytomegalovirus and herpes simplex virus (esophagus, stomach, biliary system, colon), cryptosporidium (small intestine, biliary system), Isospora belli (small intestine), salmonella, shigella, and campylobacter (small and large intestine, septicemia), and Mycobacterium avium intracellulare (liver, spleen, intestinal submucosa, and bacteremia). Involvement of the gastrointestinal tract is frequent in Kaposi's sarcoma, though it is often asymptomatic. In contrast, gastrointestinal lymphomas are aggressive and rapidly progressive tumors.

Acquired Immunodeficiency Syndrome↗

Loss of antibodies against hepatitis C virus in HIV-seropositive intravenous drug users.

A time-point survey of 262 ex-intravenous drug users (IVDUs) on methadone treatment showed serological evidence of hepatitis C virus (HCV) in 64%, hepatitis B virus in 74% and HIV in 36%. Analysis of previously collected frozen stored sera of the same patients showed that 31 further IVDUs had had anti-HCV antibodies in the past and had lost them in a time-dependent fashion. Most HCV seroreversion was detected in HIV-positive people: 20 out of 85 in the HIV-positive group versus 11 out of 18 in the HIV-negative group.

Adult↗

Primary prevention of Pneumocystis carinii pneumonia by inhalation of pentamidine. Preliminary results from a placebo-controlled randomized trial. Swiss Group for Clinical Studies on AIDS.

Patients with AIDS but without pneumocystis carinii pneumonia, patients with advanced AIDS-related complex (ARC), and asymptomatic patients with less than 200 CD4-positive lymphocytes/mm3 were randomized to one of two groups: group I: Inhalation of 300 mg of pentamidine every 28 days; group II: Inhalation of placebo (300 mg of Na isethionate) every 28 days. From May to November 28, 1989, 160 patients have entered the trial. Inhalations were well tolerated, with only a 6% use of bronchodilators and a 15% incidence of cough. Until now five patients died, none of them drug related. So far, six patients have developed pneumocystis carinii pneumonia; four of these were on pentamidine, and two on placebo. Five of the six cases occurred before the second inhalation. Recruitment will continue until 250 patients are enrolled.

Administration, Inhalation↗

[Antiviral substances: against what? For whom?].

Acyclovir and zidovudine are the two most widely used antiviral drugs. Acyclovir is efficacious against all infections caused by herpes simplex virus, but treatment must start early to be effective. Herpes zoster virus is less susceptible to acyclovir, but high doses shorten the duration of skin lesions, although the effect on post-herpetic neuralgia is uncertain. Zidovudine diminishes short-term mortality in patients with HIV infection and serious opportunistic infections. In those patients, the average increase in life expectancy is about one year. Because of myelotoxicity, frequent monitoring of blood counts is necessary. Recent results in patients who have few or no symptoms of HIV infection indicate that the drug decreases the chance of progressing to AIDS. Therefore, indications for treatment now include asymptomatic patients with unfavourable laboratory parameters.

Acyclovir↗

Behavioural changes in intravenous drug users in Geneva: rise and fall of HIV infection, 1980-1989.

In the early 1980s, more than 90% of intravenous drug users (IVDUs) shared needles and syringes in Geneva. The prevalence of antibodies to HIV in the sera of outpatient IVDUs increased from 6% in 1981 to 38% in 1983; it was, however, still only 37% in 1988. IVDUs starting methadone maintenance in 1987-1989 had a seroprevalence rate of 22%. In 1989 the percentage of IVDUs exchanging syringes and needles fell to only 5% of seropositive addicts. Only one seroconversion was observed in 1094 patient-months of observation in 1988-1989, which was probably due to sexual contact. The evidence suggests that, in the IDVUs studied, transmission of HIV has diminished since the early 1980s.

Adolescent↗

Serum levels of ciprofloxacin after single oral doses in patients with septicemia.

Ciprofloxacin serum levels were measured after administration of the drug to 36 patients with septicemia (at least one positive blood culture) who were able to take oral medication. Patients were randomly allocated to receive ciprofloxacin 500 mg p.o. (n = 21) or 200 mg i.v. over 30 min (n = 15). A first dose was administered 18-30 h after the last positive blood culture (day 1), and a second dose four days later (day 5) in some patients. In addition to ciprofloxacin, standard antibiotics were administered. Organisms isolated were Escherichia coli (15), other gram-negative bacteria (6), Streptococcus pneumoniae (7), Staphylococcus aureus (2), and other gram-positive bacteria (6). None of the patients vomited. Ciprofloxacin serum concentrations 1 h after oral administration were in the range 0.09-2.32 mg/l, and 2 h after administration in the range 0.5-7.27 mg/l. The average terminal half-life was 8.6 h. In individual patients serum concentrations and area-under-the-curve values were compared. Poor correlation was found between values measured on day 1 and day 5 after oral administration, whereas the correlation was excellent after i.v. administration. Serum levels 2 h after oral administration were 30-900 times the MICs for the gram-negative organisms, but were in the range of the MICs for the gram-positive organisms in some cases. In conclusion, ciprofloxacin serum levels are difficult to predict in septicemia patients after oral administration, but probably suffice to treat infections caused by gram-negative organisms.

Administration, Oral↗

HLA antigens are risk factors for development of AIDS.

HLA-A, -B, -C, -DR, and -DQ antigens were determined by serology and in cases of severe lymphopenia by RFLP-DNA typing in 51 Caucasians with a diagnosis of AIDS (32 with opportunistic infections and 19 with secondary cancers). In addition, 86 HIV-1 seropositive and 39 HIV-1 seronegative drug abusers and 148 healthy controls were also studied. No significant differences in HLA antigen frequencies were found in comparison of HIV-1 seropositive and HIV-1 seronegative drug abusers with controls, suggesting that HLA polymorphism does not represent a genetic risk for infection with HIV-1. In contrast, a significant increased frequency of B35 (p less than 0.01) and CW4 (p less than 0.01) was observed in both groups of AIDS patients as compared to controls. Moreover, DR2 was increased in frequency in patients with opportunistic infections (p less than 0.01) and DR3 was completely absent in patients with secondary cancers (p less than 0.05). In the latter group, the DR5 frequency was increased, although nonsignificantly. These findings provide strong evidence for the existence of HLA-linked factors of susceptibility and host resistance to AIDS.

Acquired Immunodeficiency Syndrome↗