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Biomedical subjects

S Read

Publications and source records attributed to S Read.

At least 73 records · Page 4Linked to original sources

Zidovudine for chemoprophylaxis after occupational exposure to HIV-infected blood: an economic evaluation.

Three approaches to the management of health care workers (HCWs) following percutaneous exposure to blood of previously unknown serological status were compared using cost-effectiveness analysis. In strategy A, all HCWs are offered zidovudine as soon as possible after exposure. The decision is made within 72 hours to (1) continue therapy with the drug for 4 weeks if the patient's blood is positive for human immunodeficiency virus (HIV) on testing or (2) discontinue therapy and follow-up if the patient's blood is HIV-negative. Strategy B is similar to A except that zidovudine is not offered. In strategy C the patient's blood is not tested and zidovudine is not offered. The results indicate that for every 100 HCWs managed with strategies A, B, and C, the total costs in Canadian dollars (Can $1.00 = U.S. $0.85) are $47,910, $38,849, and $110,834, respectively. The incremental cost per case of AIDS prevented by A relative to B is $300,140, and that prevented by A relative to C is -$6,244,000 (i.e., A results in savings relative to C).

Cost-Benefit Analysis↗

Detection of incident HIV infection by PCR compared to serology.

In order to determine the most sensitive method for the early detection of HIV infection, polymerase chain reaction (PCR) and serology were compared using matched peripheral blood mononuclear cells (PBMC) and serum samples taken sequentially at 3-month intervals on 17 HIV seroconverters. All samples from the time of enrollment in the study to the time of seroconversion were studied. [There were only two of the 17 cases where PCR and antigen positivity preceded EIA detectable seroconversion.] Initially, one of these cases was found to be PCR positive 11 months prior to seroconversion, however DNA fingerprinting techniques indicated that the early positive specimen did not belong to the subject in question. In a single subject, PCR was negative at the time of serologic evidence of infection but was positive at the next sampling 3 months later. In the remaining 14 cases, PCR was positive at the same sample time as full or partial seroconversion as determined by three EIA screening tests and Western blot. EIA antibody screen tests showed variability in detection of early HIV antibodies. We found no evidence for prolonged HIV infection prior to seroconversion. PCR offers little if any advantage over serology in the early detection of HIV infection in adults.

AIDS Serodiagnosis↗

Hepatitis B and human immunodeficiency virus infection in street youths in Toronto, Canada.

Hepatitis B and human immunodeficiency virus are transmitted by venereal contact or by the sharing of used needles during drug use. A questionnaire was administered to street youths admitting to prostitution and to a group denying prostitution, as well as to sexually active adolescents who lived with their family and were attending an adolescent medical clinic. The age, gender, race, number of sexual partners, condom use, illicit drug use, anal intercourse and admission to prostitution were recorded for each of the subjects. Serology was obtained for hepatitis B markers and human immunodeficiency virus antibody. Multiple regression analysis was performed to determine the factors which might predict hepatitis B serologic status. A single subject, who admitted to prostitution, was found to be human immunodeficiency virus-seropositive. Seven of 43 (16%) admitted prostitutes compared with 1 of 44 (2%) other street youth and none of 27 controls demonstrated anti-hepatitis B surface antibodies. The higher rate of seropositivity in admitted prostitutes was statistically significant (P less than 0.0097). Two seropositive prostitutes had IgM hepatitis B core antibody suggesting recent infection. Two factors, number of partners (P less than 0.0007) and practice of anal intercourse (P less than 0.05), were identified in the multiple regression analysis as predictive of seropositivity. Thus adolescents who live on the street are at increased risk for becoming infected with hepatitis B virus. The difficulty in ensuring vaccine coverage in this population would support calls for including hepatitis B vaccination as part of childhood immunization.

Adolescent↗

Cyclosporine-induced deterioration in patients with AIDS.

Eight patients with AIDS (acquired immune deficiency syndrome) but free of life-threatening infection were treated with the immunosuppressive drug cyclosporine for a mean of 53.9 days. The serum cyclosporine levels were maintained in the desired therapeutic range. All eight patients experienced severe toxic symptoms, which necessitated discontinuation of cyclosporine therapy in six. The serum levels of creatinine, urea and potassium rose during treatment and fell after therapy was stopped. The total leukocyte count, hemoglobin level, platelet count, total T-cell count, and T4- and T8-cell counts all fell markedly during treatment. The total leukocyte count, platelet count, and T4- and T8-cell counts rose after therapy was stopped, but the hemoglobin level remained low. No patient experienced resolution of symptoms during therapy, and the condition of all patients improved after treatment was stopped. The results of this pilot study indicate that cyclosporine does not alleviate, and may worsen, the symptoms and laboratory findings in patients with AIDS.

Acquired Immunodeficiency Syndrome↗

Factors influencing erythrocyte choline concentrations.

Choline concentrations in human erythrocytes increase after freezing and thawing, during incubation in Krebs-phosphate for 30 min or on storage at 0 degrees C for 3-24 hr. The increase is prevented by protein precipitation by 10% perchloric acid, 10% zinc hydroxide, 10% sodium tungstate or boiling in water. It is not prevented by EDTA (10 mM) and is increased by oleate (5 mM). We suggest that the increase is due to the action of phospholipase D on erythrocyte phospholipids.

Calcium↗

Proverb and idiom comprehension in Alzheimer disease.

Twenty-nine patients diagnosed with Probable Alzheimer Disease were administered tests of word, familiar phrases (idioms and proverbs), and novel phrase comprehension. From the early stage of the disease, patients performed worse at understanding familiar phrases than single words or novel phrases. The results uphold common observations that AD patients have difficulty interpreting abstract meanings. Cognitive variables responsible for poor idiom/proverb comprehension and the clinical implications of this new protocol are discussed.

Aged↗

Humoral and cellular immune abnormalities in adult hemophiliacs followed over a 2-year period.

Immune function was assessed in 93 adult hemophiliacs in the 2 years prior to HTLV-III antibody testing of blood donors and routine heat treatment of coagulation factor concentrates. Parameters of humoral and cellular immunity studied included serum complements, immunoglobulins, immune complexes, blood cell counts, lymphocyte subsets, lymphocyte transformation, 2-5A synthetase, serology for HTLV-III and hepatitis B, skin tests, and clinical status. HTLV-III seropositivity was significantly more prevalent in patients treated with factor VIII concentrate; seropositive patients had a higher proportion of abnormal test results and were more symptomatic. Although many subjects had abnormal test results, specific test results generally did not correlate with type of blood component received or time of preceding treatment. The proportion of tests abnormal in individual patients was correlated with the intensity of factor replacement therapy when the time interval from the last treatment was a covariate. While T8+ lymphocytes were increased and T4/T8 ratios were decreased in many patients, significantly reduced T4+ lymphocytes were seen only in seropositive patients and in those treated with factor VIII concentrate. Neither seropositivity nor presence of symptoms correlated with abnormal lymphocyte mitogenic response or 2-5A synthetase levels, but synthetase levels were increased in 65% of patients tested. Over the 2-year study period, no significant deterioration of clinical or laboratory variables was observed in the patients. Abnormalities of immune function were found to be common in hemophiliacs regardless of type of treatment or of evidence of HTLV-III infection.

Antibodies, Viral↗

Abnormal erythrocyte choline and influx in Alzheimer's disease.

Choline transport and levels were studied in erythrocytes from patients with Alzheimer's disease and age-matched controls using stable isotopic tracer techniques. The mean erythrocyte choline in the Alzheimer group was 50.1 nmol ml-1 compared to 15.5 nmol ml-1 in the controls. This was significant using a Student's t test at a P of less than 0.0005. Influx of choline into the erythrocyte correlated inversely with erythrocyte choline with high significance. This study suggests that erythrocyte choline is elevated in a subset of patients with Alzheimer's disease and that the low affinity transport system is also abnormal in these patients. This abnormality of choline transport may play a role in the pathogenesis of Alzheimer's disease in some patients.

Aged↗

Aphasia in dementia of the Alzheimer type.

Speech and language assessment in 30 patients with dementia of the Alzheimer type and in 70 normal controls revealed that all Alzheimer patients were aphasic. Throughout most of the course, the language disorder resembled transcortical sensory aphasia, and increasing language impairment correlated with increasing severity of dementia. Aphasia was present regardless of age of onset or family history of dementia. Aphasia is an important diagnostic criterion of dementia of the Alzheimer type.

Adult↗

Amnesia with hippocampal lesions after cardiopulmonary arrest.

A patient developed an amnesic syndrome after cardiopulmonary arrest. Neuropathologic examination revealed pronounced anoxic injury to both hippocampi with little damage to other hemisphere structures. The clinical and pathologic findings suggest that lesions limited to the hippocampus can cause profound amnesia.

Amnesia↗

Value of computerised tomography in children with non-specific mental subnormally.

Seventy-six children had computerized tomography scans as part of an investigation of mental subnormality; most of them are severely retarded and all those over age 5 years attend special schools. Seventy-two per cent of the children had normal scans. Twenty per cent showed cerebral atrophy and in only 8% was there a specific abnormality (agenesis of corpus callosum, arachnoid cyst, communicating hydrocephalus). None of these findings had any positive prognostic implication. Sedation or general anaesthesia was required for all except one child. Injection pethidine compound was used for children under age 5 years or less than 30 kg in weight, and trimeprazine orally was used for older children. The radiation exposure was high--5.6 rad per scan, which is 100 times greater than that from a posteroanterior and lateral chest x-ray film. For these reasons computerised tomography scans cannot be recommended as a routine part of the investigation of children with non-specific mental subnormality.

Adolescent↗