Biomedical subjects
Publications and source records attributed to W Livingston.
Two patients infected with human immunodeficiency virus (HIV) presented with persistent, large, and painful oral ulcers. Results of cultures and examination of a biopsy specimen were negative for infection and malignancy. Major aphthous-like ulcers should be considered in the differential diagnosis of oral ulcers in the HIV-infected patient.
High-resolution infrared spectra of sunspot umbrae have been recorded with the 1-meter Fourier transform spectrometer on Kitt Peak. The spectra contain a very large number of water absorption features originating on the sun. These lines have been assigned to the pure rotation and the vibration-rotation transitions of hot water by comparison with high-temperature laboratory emission spectra.
The pulmonary isozyme of rabbit angiotensin-converting enzyme (ACE) is encoded by an mRNA of about 5 kb. cDNA clones corresponding to different parts of this mRNA have been isolated and the complete nucleotide sequences of both the coding and non-coding regions of the mRNA have been determined. The encoded protein has 1309 residues with a 33 amino acids-long signal peptide at the amino terminus and a potential membrane-anchoring domain near the carboxyl terminus. There is a strong sequence homology between two regions of the rabbit cDNA and between the rabbit, human, and mouse cDNAs. Comparison of the nucleotide sequences of the 3' untranslated regions of rabbit pulmonary and testicular ACE cDNAs revealed that the testicular cDNA is nested within the pulmonary cDNA at the 3' end. A rabbit genomic clone encompassing this region was isolated and partially sequenced. It was shown that the gene contains two potential polyadenylation sites 628 bp apart within one exon. Northern analyses with an appropriate oligonucleotide probe confirmed that the proximal polyadenylation site is used exclusively for terminating the testicular mRNA whereas the distal one is used exclusively for the pulmonary mRNA. These results demonstrated that the transcription of the two mRNAs encoding the two ACE isozymes not only initiates at two alternative tissue-specific sites which are 5.7 kb apart but the mRNAs also get polyadenylated at two alternative sites which are 628 bp apart.
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Angiotensin-converting enzyme (ACE) is present in endothelial and epithelial cells of various tissues as well as in the circulating plasma. The structural relationship between the cellular and the secreted forms of ACE and the pathways to their biosynthesis have not been determined as yet mainly because of the unavailability of a natural cell line expressing ACE in tissue culture. To circumvent this problem we have permanently transfected a mouse epithelial line with an expression vector containing the recently cloned rabbit testicular ACE cDNA. Clonal derivatives of this line secreted large quantities of enzymatically active ACE. When these cells were cultured in serum-free medium, the only detectable protein in the culture medium was ACE. It has been suggested that a hydrophobic domain near the carboxyl terminus of the enzyme anchors it to the plasma membrane. To test this hypothesis we established cell lines expressing a truncated form of the active enzyme which is missing the putative anchoring domain. Pulse-chase experiments showed that the truncated ACE was secreted from the cells much faster than the native enzyme. Moreover, the secreted form of the native enzyme had a lower molecular weight than the corresponding cellular form. These results are consistent with the hypothesis that the hydrophobic domain is instrumental in keeping the enzyme cell-bound, and secretion is achieved physiologically by removal of this domain from the enzyme by a specific proteolytic cleavage.
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After oral therapy with ampicillin for an unrelated disorder, two patients developed gastroenteritis with an ampicillin-resistant strain of Shigella sonnei. Both patients recovered after treatment with antimicrobial agents to which the Shigella was susceptible by in vitro testing.
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OBJECTIVE: To determine whether women's global self-assessment of their knowledge about hormone replacement therapy (HRT) corresponds to their performance on an explicit knowledge test about HRT and to measure associations among knowledge, personal characteristics, decision conflict, and intention to use HRT. DESIGN: Preintervention telephone survey of 156 women enrolled in a randomized, placebo-controlled trial of HRT decision aids. RESULTS: The mean rating of menopause knowledge, on a scale from 1 to 10, with 10 indicating being "extremely knowledgeable," was 5.6 (range = 0-10) and of HRT was 4.2 (range = 0-9). The mean summary score for the explicit HRT knowledge test, on a 16-point scale, was 7.8 (range = 0-15). After adjustment for demographic characteristics and exposure to a provider conversation, higher income, white race, and the provider discussion were significant correlates of knowledge. Explicit knowledge was positively correlated with self-assessed menopause knowledge and HRT knowledge (Spearman's correlation coefficient = 0.39 and 0.52, respectively; p < 0.0001). Greater knowledge was not associated with intention to use HRT 1 year later. Women who had greater knowledge reported less conflict about the HRT decision (Spearman's correlation coefficient = -0.32; p < 0.0001). CONCLUSIONS: A global question about level of knowledge is an effective clinical tool for identifying patients who are in need of additional education about HRT and menopause in this managed care population. Increased knowledge may decrease women's conflict about the HRT decision. Having had a previous conversation about menopause with a primary care provider is associated with greater knowledge about HRT.