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Biomedical subjects

J McArthur

Publications and source records attributed to J McArthur.

At least 19 recordsLinked to original sources
PubMed1995

Generation of a transcription map at the HSD17B locus centromeric to BRCA1 at 17q21.

A detailed transcription map of the 320-kb region containing the HSD17B locus on chromosome 17 was generated. Thirty unique cDNA fragments, retrieved following the hybridization of immobilized YACs to primary pools of cDNAs prepared from RNA of mammary gland, ovary, placenta, and the Caco-2 cell line, were aligned into 10 transcription units by physical mapping and hybridization to RNAs of a series of tissues. The cDNAs were then further characterized by sequencing and used to screen mammary gland cDNA libraries. Fragments corresponding to the broadly expressed gamma-tubulin and Ki antigen genes were identified. A full-length cDNA clone encoding a 117-amino-acid protein homologous to the rat ribosomal protein L34 was isolated. Portions of genes with restricted patterns of expression were also obtained, including the previously characterized HSD17B1. One new gene, for which a full-length cDNA was isolated, was found to have an interesting tissue-specific pattern of expression with abundant mRNA in both the colon and the testis and in the mammary carcinoma cell line BT-474. This contrasted with the barely detectable level observed in several tissues including normal mammary gland. Of the five additional transcription units identified, one showed no similarity, two showed identity to human expressed sequences, and two displayed similarity to genes of animal species by amino acid alignment. These latter cDNA clones include potential homologues of a rat nuclear tyrosine phosphatase and of a factor of Drosophila that is known to be involved in the negative regulation of transcription of segment identity genes.

Amino Acid Sequence↗
PubMed1995

An epidemiologic analysis of Mycobacterium avium complex disease in homosexual men infected with human immunodeficiency virus type 1.

Cofactors associated with the Mycobacterium avium complex (MAC) disease and its prognosis in incident cases of AIDS in homosexuals were studied. We compared 51 men in whom MAC disease developed as the initial AIDS-defining illness (termed AIDS illness hereafter); 157 men who had MAC disease subsequent to another AIDS illness; and 884 men who had only non-MAC AIDS illnesses. MAC disease was the initially diagnosed AIDS illness more often in Baltimore (6.9%) and Los Angeles (5.6%) than in Chicago (2.6%) and Pittsburgh (0) (P < .01). MAC disease also was a more common subsequent AIDS illness in Baltimore (14.3%) and Los Angeles (22.4%) than in Chicago (8.5%) and Pittsburgh (6.5%) (P < .0001). Prophylaxis for Pneumocystis carinii infection increased the occurrence of MAC disease as the initial AIDS illness (from 2.3% to 12.5%; P < .0001). A low white blood cell (WBC) count was slightly more predictive of MAC disease than was a low CD4+ cell count. At 0-6, 7-12, and 13-18 months before diagnosis, the WBC cell counts of 75.0%, 61.1%, and 50.0%, respectively, of those with MAC disease as the initial AIDS illness were < or = 3,400/microL. Men in whom cytomegalovirus disease developed were at higher risk for subsequent MAC disease (relative hazard = 2.65; P < .0001). MAC disease also increased the risk for subsequent cytomegalovirus disease (relative hazard = 3.96; P < .0001).

AIDS-Related Opportunistic Infections↗
PubMed1992

AIDS and multiple sclerosis: neural and mental features.

The presence of mental disorder and cognitive functioning were examined in groups of 20 multiple sclerosis (MS) and homosexual acquired immunodeficiency syndrome (AIDS) ambulatory male outpatients matched for disability and demographic features. Patients who were somatically ill, had past central nervous system infection or tumours or abused intravenous drugs or alcohol were excluded. The groups significantly differed in mental symptoms and mental disorders (DSM-III classification) seen currently and after the diagnosis of MS or human immunodeficiency virus-1 infection. AIDS patients had pre-existing anxiety disorders that affected their current mental symptoms. MS patients showed more evidence of cognitive impairment than equally disabled AIDS patients. The differing neural and mental features are discussed in relation to the current concepts of subcortical and cortical disorders.

AIDS Dementia Complex↗
PubMed1991

Metacognition in HIV-1 seropositive asymptomatic individuals: self-ratings versus objective neuropsychological performance. Multicenter AIDS Cohort Study (MACS).

This study examined the relationship between actual and self-reported neuropsychological deficits, depression, and HIV-1 serostatus. The subjects, who consisted of 479 individuals, 256 who were HIV seronegative (SN) and 233 who were HIV-1 seropositive though still asymptomatic (ASP), were administered a standardized neuropsychological screening battery consisting of measures of attention, motor speed, psychomotor speed, verbal memory, verbal fluency, and depression. To assess subjects' subjective sense of their cognitive status, the Cognitive Failures Questionnaire (CFQ), a 25-item self-report questionnaire, was also administered. The results of MANOVA failed to reveal group differences between the SN and ASP groups on the measures of neuropsychological function. Similarly, the ASP and SN groups did not differ on the number or severity of reported cognitive failures. However, a positive correlation was found between CFQ scores and level of depression. These results do not support the hypothesis that ASP individuals are aware of cognitive decline prior to detection using standard neuropsychologic screening instruments. The data do suggest that the presence of depressed mood, independent of serostatus or actual neuropsychological impairment, is associated with increased cognitive complaints.

Adult↗
PubMed1990

HIV-1 infection: no evidence of cognitive decline during the asymptomatic stages. The Multicenter AIDS Cohort Study.

Cross-sectional studies have not adequately resolved the question of whether subjects infected with HIV-1 may suffer cognitive decline during the early, asymptomatic stages of the infection. We studied longitudinally 238 asymptomatic healthy HIV-1-infected homosexual/bisexual men (CDC groups 2 and 3) and 170 uninfected controls in the Multicenter AIDS Cohort Study with neuropsychological testing at semiannual intervals. A comparison of change in scores between visits 1 and 4 as well as a multivariate autoregressive analysis revealed no evidence of decline in test performance over time in the HIV-1-infected group compared with the seronegative controls. These findings suggest that a gradual cognitive decline does not occur during the early, asymptomatic stages of HIV infection.

Adult↗
PubMed1989

Microphysiological recordings at CT gantry site during stereotactic thalamotomy.

Neural unit recording was performed during CT-guided stereotactic thalamotomy in 2 patients referred for severe cerebellar ataxia and dysmetric movements. Periodic CT scanning was performed during the recording in order to verify probe location and trajectory. Our experience with electrophysiological recordings at the CT gantry site demonstrates the feasibility of acquiring satisfactory neural unit recordings in spite of the high-voltage environment.

Brain↗
PubMed1989

Intraoperative CT-guided serial microbiopsy of brain lesions and concomitant use of CT air and angiographic studies.

The value of step-by-step confirmation of the location of the brain biopsy probe is demonstrated, using serial CT scanning to confirm the exact source of the sample tissue. Concomitant use of CT angiography and a CT air study makes possible the biopsy of small areas and of areas near major cerebral vessels, as well as of lesions near critical areas like the optic chiasma, basal ganglia, midbrain, and other complex lesions. The pathologist on-line examination of the CT-confirmed serial samples enables the surgeon to obtain the most informative tissue for the ultimate histopathological diagnosis. Our experience with the technique is illustrated by examples of its application in some complex cases.

Biopsy↗
PubMed1989

Nifedipine in the prophylaxis of classic migraine: a crossover, double-masked, placebo-controlled study of headache frequency and side effects.

Twenty-four patients with classic migraine attacks were treated with either nifedipine or placebo for up to 12 weeks. No significant differences were observed between the nifedipine (2.1 +/- 0.2) and placebo (2.3 +/- 0.2) treatment groups in the monthly frequency of headaches. However, the incidence of side effects was significantly greater (p less than 0.001) in the nifedipine (54% of patients) than in the placebo (8% of patients) treatment groups.

Clinical Trials as Topic↗
PubMed1985

Diagnosing dementia. Univariate and multivariate analyses of the mental status examination.

Investigators have reported poor recognition of dementia by primary physicians. For this reason, mental status examinations were performed on 72 demented and 144 nondemented medical inpatients to assess the sensitivity, specificity, and predictive value of components of this examination in the diagnosis of dementia. Sensitivity of individual level-of-orientation items was low (15.3 to 56.9%), though specificity was high (91.7 to 100%). Sensitivity of several nonorientation items was high (80.6 to 100%), though specificity was low. A multivariate discriminant equation using both orientation and nonorientation items achieved high sensitivity (89.6% test cases, 87.5% validation cases) and specificity (78.1% test cases, 87.5% validation cases). Adding the easily obtained patient characteristic of age to the equation further increased sensitivity (95.8%, 91.3%), while maintaining specificity (82.3%, 85.4%). From these results, it is concluded that the level-of-orientation screening examination used by clinicians to detect dementia is unacceptably insensitive. In contrast, a composite decision rule including nonorientation items achieves high sensitivity with relatively high specificity.

Adult↗
PubMed1983

The first Scottish "Leopard"?

Leopard Syndrome is a rare autosomal dominant condition affecting multiple systems. We report a 35-year-old woman with hypertrophic obstructive cardiomyopathy, pigmented naevi and growth retardation. We are unaware of previous cases reported in Scotland.

Adult↗
PubMed1982

Septic arthritis caused by Propionibacterium acnes.

The traditional view that Propionibacterium acnes is nonpathogenic for man, except as an agent associated with acne vulgaris, has been refuted. Propionibacterium acnes has been shown to cause endocarditis, meningitis, and other serious infections. We report a case of P acnes infection causing septic arthritis and contributing to a concurrent soft-tissue infection. This case supports and extends previous observations of the clinical importance of P acnes as a pathogen. A positive culture for P acnes cannot be uncritically dismissed as a bothersome contaminant without considering the clinical circumstances.

Abscess↗