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Biomedical subjects

A J Davidson

Publications and source records attributed to A J Davidson.

105 records · Page 6Linked to original sources
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Anorectal gonorrhea in women. Is it more difficult to cure?

It is unclear whether anorectal gonorrhea in women is more difficult to cure than endocervical gonorrhea or whether anorectal test-of-cure cultures are always indicated. Using endocervical and anorectal test-of-cure cultures, the authors evaluated 1,124 women treated for culture-positive endocervical gonorrhea with a recommended regimen of ampicillin (n = 868), procaine penicillin G (n = 78), spectinomycin (n = 45), or tetracycline (n = 133). There were 35 failures (3.1%) among women with anogenital gonorrhea, including 11 (1.0%) among those with anorectal infection. Only eight failures (0.7%) were detected by anorectal culture alone. Although anorectal isolates of Neisseria gonorrhoeae obtained before treatment from women were significantly (P less than .05) less susceptible to tetracycline than were endocervical isolates (geometric mean MIC, 0.35 micrograms/ml vs. 0.21 micrograms/ml), there were no failures of treatment of anorectal infection when tetracycline was used. The authors conclude that anorectal infection in women is not more difficult to treat than endocervical infection. Because of the very high cost-per-case ratio, anorectal test-of-cure cultures in women should be accorded a low priority in a gonorrhea control program.

Ampicillin↗
PubMedDate not supplied

Factors influencing the risk of infection with human immunodeficiency virus in homosexual men, Denver 1982-1985.

The factors associated with infection with the human immunodeficiency virus (HIV) in 216 homosexual men enrolled from November 1982 through December 1985, including 40 asymptomatic HIV seronegative, 20 asymptomatic seropositive, 66 with generalized lymphadenopathy (GLS), 37 with AIDS-related complex (ARC), and 53 with AIDS were studied. Because univariate analysis did not show significant differences between asymptomatic seropositive men and men with GLS or between men with ARC and AIDS, these groups were combined for analysis. In multivariate analysis the number of episodes of receptive and intercourse, the age at which regular sexual intercourse with a male partner was started, the use of enemas, sexual contact with someone with ARC or AIDS, and a history of hepatitis B were all independently associated with HIV infection. In univariate analysis the men with ARC or AIDS did not differ significantly from asymptomatic seronegative men as to number of episodes of receptive or insertive anal intercourse and number of sexual partners, but this most likely represents confounding that occurs when current risk factor behavior in fatally ill men is used in place of risk factor behavior at the time of HIV transmission. It indicates, however, that this group has become less sexually active and that HIV infection is largely spread by relatively healthy infected men.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Imaging and pathologic features of myelolipoma.

Myelolipoma is a benign tumor consisting of mature fat interspersed with hematopoietic elements resembling bone marrow. Imaging findings in a large series of pathologically proved cases of myelolipoma were correlated with the pathologic and histologic features of the lesions. Myelolipoma manifests in four distinct clinicopathologic patterns: isolated adrenal myelolipoma, adrenal myelolipoma with hemorrhage, extraadrenal myelolipoma, and myelolipoma associated with other adrenal disease. Myelolipoma is difficult or impossible to detect at plain radiography unless the lesion is large and predominantly fatty. At ultrasound, myelolipoma often has heterogeneous echogenicity due to its typically nonuniform architecture. Computed tomography (CT) frequently demonstrates large amounts of fat with areas of interspersed higher-attenuation tissue. At magnetic resonance imaging, predominantly fatty areas usually have increased signal intensity on T1-weighted images and moderate hyperintensity complicated by the presence of marrowlike elements in the corresponding regions on T2-weighted images. The imaging appearance of myelolipoma is altered by the presence of hemorrhage. In such cases, CT is the most accurate method for evaluation. Knowledge of the imaging characteristics of myelolipoma usually allows presumptive diagnosis, although percutaneous needle biopsy may be needed to confirm the diagnosis in cases of extraadrenal myelolipoma. Surgical excision is unnecessary unless the diagnosis is unclear or the lesion is symptomatic. Asymptomatic, nonhemorrhagic myelolipomas do not require therapy.

Adrenal Gland Diseases↗
PubMedDate not supplied

Cardiovascular tissues contain independent circadian clocks.

Acute cardiovascular events exhibit a circadian rhythm in the frequency of occurrence. The mechanisms underlying these phenomena are not yet fully understood, but they may be due to rhythmicity inherent in the cardiovascular system. We have begun to characterize rhythmicity of the clock gene mPer1 in the rat cardiovascular system. Luciferase activity driven by the mPer1 gene promoter is rhythmic in vitro in heart tissue explants and a wide variety of veins and arteries cultured from the transgenic Per1-luc rat. The tissues showed between 3 and 12 circadian cycles of gene expression in vitro before damping. Whereas peak per1-driven bioluminescence consistently occurred during the late night in the heart and all arteries sampled, the phases of the rhythms in veins varied significantly by anatomical location. Varying the time of the culture procedure relative to the donor animal's light:dark cycle revealed that, unlike some other rat tissues such as liver, the phases of in vitro rhythms of arteries, veins, and heart explants were affected by culture time. However, phase relationships among tissues were consistent across culture times; this suggests diversity in circadian regulation among components of the cardiovascular system.

Animals↗
PubMedDate not supplied

Socioeconomic differences among people with AIDS: results from a Multistate Surveillance Project.

To characterize the socioeconomic status of persons with acquired immunodeficiency syndrome (AIDS), 11 U.S. state and city health departments interviewed 2,898 persons > or = 18 years of age reported with AIDS between June 1, 1990, and January 31, 1993. Among men who have sex with men, white men reported the lowest percentage (9%), and Central/South American (50%) and Mexican men (40%) reported the highest percentages not completing 12 years of school. Among intravenous drug users (IDUs), 35% of white men, 64% of black men, 67% of Puerto Rican men, 29% of white women, and 63% of black women had not completed 12 years of school. Overall, 77% of the men and 90% of the women were unemployed; we also found racial/ethnic differences by employment but to a lesser degree than differences in education. Among women, but not among men, differences in household income by race and ethnicity were marked; 76% of white and 91% of black female IDUs reported a household income of $10,000. Human immunodeficiency virus (HIV) prevention programs must be targeted toward the educational level of the populations served, and HIV services must adapt to the financial circumstances of their clientele.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Extent of undiagnosed HIV infection in hospitalized patients: assessment by linkage of seroprevalence and surveillance methods.

Routine screening of hospitalized patients for human immunodeficiency virus (HIV) infection has been suggested as a method to identify undiagnosed HIV infection. To evaluate HIV seroprevalence and rates and risk factors for undiagnosed HIV infection among inpatients at an urban hospital, we linked a blinded HIV seroprevalence survey with data from a health care systemwide HIV surveillance registry. Consecutive nonobstetric adult inpatients admitted over four months had remnant samples of serum and plasma obtained and demographic and clinical data abstracted from hospital registration and outpatient encounter billing files. After linkage with the HIV registry, patient data were assigned a study code, individual identifiers were removed, and specimens were tested for HIV-1 antibody. Of 2,825 eligible patients, 155 (5.5%) were HIV-seropositive: 139 (90%) with known infection and 16 (10%) with previously undiagnosed infection. Of those with previously undiagnosed infection, eight (5%) were newly diagnosed during hospitalization and eight (5%) remained undetected following hospitalization. For HIV-seropositive patients, previously undiagnosed infection was significantly more common among those with no use of the health care system in the past year than those with recent outpatient or inpatient visits (41.7% versus 4.6%, odds ratio [OR] = 14.9, 95% confidence intervals [CI] = 4.7, 47.1). Despite a relatively high hospital HIV seroprevalence, the rate of undiagnosed infection was low, suggesting that the percentage of the HIV epidemic remaining "undetected" may be smaller in some settings than suggested by previous studies of hospitalized patients. Linkage of surveillance data to blinded seroprevalence studies can be of value in estimating this "undetected" percentage and in evaluating the potential yield of routine HIV testing programs. Medical Subject Headings (MeSH): HIV infection, risk factors, HIV seroprevalence, inpatients, HIV screening, population surveillance.

Adolescent↗
PubMedDate not supplied

Factors associated with screening mammography in low-income women.

Despite its effectiveness as a preventive measure, studies indicate that low-income and minority women are less likely to obtain screening mammograms than other groups. Using a logistic regression model to adjust for multiple variables, we examined factors associated with women age > or = 40 years of age who obtained a screening mammogram in a community health center setting from 1990 to 1991 (screened, n = 3,521; nonscreened, n = 7,461). Women 50-64 were more likely to be screened than women 40-49 (adjusted relative risk [RR] = 1.57; 95% confidence interval [CI] = 1.42, 1.73). Native American, Asian, and women of other races were less likely to be screened than Caucasian, African-American, or Hispanic women (adjusted RR = 0.66; CI = 0.51, 0.87). Women on Medicaid were twice as likely to be screened than women who received no subsidized care (adjusted RR = 1.99; CI = 1.68, 2.35). Women who received the majority of their care at a community-based health clinic were twice as likely to be screened than women who received care primarily at a hospital-based ambulatory care site (adjusted RR = 2.34; CI = 2.06, 2.65). The greatest difference in adjusted RR was seen for women who had > or = 4 visits per year compared to women with < 4 visits (RR = 4.6; CI = 4.18, 5.06). On average, women in the screened population had fewer emergency room visits and more primary care and specialty clinic visits compared to the nonscreened population. Reducing the cost of mammography to the patient and providing systems for physician referral from hospital-based settings (emergency rooms, specialty clinics) may help increase the number of low-income and minority women who obtain screening mammograms. Medical Subject Headings (MeSH): mammography, screening, community health center, low-income, minority.

Adult↗