Biomedical subjects

L E Kimball

Publications and source records attributed to L E Kimball.

5 recordsLinked to original sources

PubMed2002

Does smoking increase relapse rates in Graves' disease?

We wondered whether the relapse rate of Graves' hyperthyroidism was increased amongst patients who smoked. To this end, a retrospective analysis of clinical and laboratory data of consecutive patients with Graves' disease was carried out. All patients were treated with thionamide anti-thyroid drugs (ATD) for at least one year and remission was defined as continued and biochemical euthyroidism, at least 6 months after discontinuing ATD. The study comprised 221 subjects with Graves' disease from a hospital-based population over 9 years. We took the following variables into account when assessing contribution to disease relapse: Goiter, Thyroid Associated Ophthalmopathy (TAO), and Time to euthyroidism after starting ATD and interaction between smoking and sex. Smoking had a marginally significant (p=0.081) deleterious effect on the likelihood of remission after ATD treatment for Graves' disease. The effect of smoking was, however, highly significant in males and indeed the deleterious effect on remissions may be restricted to males (odds ratio, 11.1; 95% confidence interval, 1.25 to 98.5). The presence of goiter (odds ratio, 3.8; 95% confidence interval, 2.05 to 7.1) and TAO (odds ratio, 1.8; 95% confidence interval, 0.993 to 3.18) forecasted lower chances of achieving remission. The shorter the time a patient became euthyroid after starting ATD the more likely his disease was to remit. We conclude that cigarette smoking increases the likelihood of Graves' disease recurrence in males treated with anti-thyroid drugs. Thus, smoking appears to be an important risk factor in the pathogenesis and outcome of Graves' disease patients at least in subsets of patients.

Adult↗

PubMed2001

Performance on paced serial addition tasks indicates an associative network for calculation.

Although paced serial addition (PSA) tasks are considered to be tests of general information-processing capacity, recent work suggests that performance on such tasks is influenced by arithmetic-specific variables. We designed two visual PSA experiments to determine whether the performance of normal adults would support predictions derived from the cognitive psychology of calculation. Experiment 1 showed that mixing familiar (Arabic numeral) and less familiar (Roman numeral) stimulus formats reduced scores below the averaged scores for pure Arabic and Roman lists. The Roman-Arabic order of addends was more difficult than the Arabic-Roman order. Experiment 2, which involved only Arabic numerals as addends, showed that performance could be impaired by constraining the trial-to-trial variability of sums. The results of both experiments confirm the importance of arithmetic-specific variables in PSA and provide support for an associative network model of calculation. In addition, the findings implicate interference from extraneous addends and responses as the performance-limiting factor.

Adult↗

PubMed1998

Paced serial addition: modality-specific and arithmetic-specific factors.

Tests of paced serial addition are used to detect diminished information-processing capacity. Nonetheless, performance might be influenced by modality-specific interference or by variables that specifically affect numerical processing. In a series of three experiments with normal adults, we manipulated, respectively, the modality in which addends were presented, the modality in which responses were produced, and the format in which visual addends were displayed. Performance was enhanced when stimuli were presented visually and when responses were made manually. When visual addends were used, Arabic numerals were processed more effectively than number words. Thus, performance was influenced by modality-specific interference and by presentation format. We conclude that paced serial addition tasks may not provide a pure measure of general information-processing capacity.

Acoustic Stimulation↗

PubMed1997

Infection of Macaca nemestrina neonates with HIV-1 via different routes of inoculation.

OBJECTIVES: Receptive anal intercourse but not orogenital sex has been identified as a major risk factor for transmission of HIV-1. Recent studies using simian immunodeficiency virus (SIV) in rhesus macaques have demonstrated relatively efficient infection following oral administration, indicating that modes of transmission may vary between HIV-1 and SIV. Here, we investigate whether HIV-1 infection of macaques via the oral route is more efficient than via the rectal route. DESIGN: Eleven Macaca nemestrina neonates were exposed to HIV-1 via different routes (four oral, two intravenous, and five rectal). One animal was orally inoculated with a sham inoculum and two control animals were not exposed. METHODS: All animals were followed for virological signs of infection, and for pathogenesis associated with HIV-1 infection by general physical examinations, complete blood cell counts and lymphocyte subset analysis, and full necropsies. RESULTS: Three out of five rectally exposed macaques and both of the intravenously inoculated animals became infected with HIV-1, whereas none of the orally exposed animals showed evidence of HIV-1 infection. Clinical observations following exposure included failure to thrive in the orally inoculated animals and low CD4/CD8 ratios in the rectally exposed macaques. CONCLUSIONS: The finding that, contrary to what has been reported for SIV, transmission of HIV-1 via the oral route is not more efficient than via the rectal route, indicates important biological differences between HIV-1 and SIV, with direct implications for the spread of HIV and associated AIDS, and for development of anti-HIV-1 vaccines.

Animals↗

PubMedDate not supplied

In vitro HIV-1 infection in Macaca nemestrina PBMCs is blocked at a step beyond reverse transcription.

Various stages in the lifecycle of HIV-1 were investigated in Macaca nemestrina and humans in vitro. Early events were analyzed by end point dilution DNA PCR with HIV-1 and SHIV infected PBMCs, while p24 and p27 ELISA assays were used to analyze core antigen production from infected cells. The results demonstrate that a step in the virus life cycle, beyond reverse transcription is blocked for HIV-1 infection in macaque cells.

Animals↗