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Biomedical subjects

J D Malone

Publications and source records attributed to J D Malone.

At least 19 recordsLinked to original sources
PubMed2001

Clinical prognosis of patients with early-stage human immunodeficiency virus (HIV) disease: contribution of HIV-1 RNA and T lymphocyte subset quantitation.

Systems for the staging of individuals with human immunodeficiency virus type 1 (HIV-1) infection were developed 15 years ago. Subsequently, assays for quantitating HIV-1 RNA and immunophenotyping of lymphocyte subsets have been developed and validated. The utility of these assays for improved staging in early disease was evaluated in 256 HIV-infected adults (52% minority) with CD4 counts > or = 400 cells/microL followed in U.S. military medical centers before the highly active anti-retroviral therapy era. HIV viral load (RNA) was quantitated; the frequencies of select CD4+ immunophenotypes were determined in 112 subjects. The results were analyzed in relation to three outcome measures: death, first acquired immunodeficiency syndrome-defining opportunistic infection, and CD4 count < or = 200 cells/microL. Serum RNA level and CD4 count were each found to be predictive of all three outcomes. In addition, increases in the T-cell subsets CD28-CD4+ and CD29+CD26-CD4+ were found to be independently predictive of more rapid progression. The classification of early-stage HIV patients is improved by the quantitation of both viral RNA and T-lymphocyte subsets.

Adult↗
PubMed1998

CD38 expression on cryopreserved CD8+ T cells predicts HIV disease progression.

Previous studies have revealed that the expression of CD38 on CD8+ T cells is a strong predictor of disease progression in human immunodeficiency virus (HIV)-infected individuals. Those studies were performed using fresh patient samples over an extended trial period. After demonstrating the validity of assay results on cryopreserved cells, we performed a retrospective study using frozen cell samples to determine the predictive value of CD38 expression in patients with CD4 counts above 400 cells/microl. The CD38 expression as measured by antibody binding capacity and the CD38 median channel were shown to be associated with time to new opportunistic infection or death (both P < 0.001). These results suggest that CD38 expression on CD8+ T cells, whether fresh or frozen, provides a useful predictor of HIV disease progression.

ADP-ribosyl Cyclase↗
PubMed1998

Anthrax as a potential biological warfare agent.

Anthrax is a zoonotic illness recognized since antiquity. Today, human anthrax has been all but eradicated from the industrialized world, with the vast majority of practitioners in the United States unlikely to have seen a case. Unfortunately, the disease remains endemic in many areas of the world, and anthrax poses a threat as a mass casualty-producing weapon if used in a biological warfare capacity.

Animals↗
PubMed1998

A survey of women's health care needs on U.S. Navy ships.

A total of 628 female and 526 male U.S. military personnel completed a health survey questionnaire at the completion of four shipboard deployments lasting 10 to 180 days (mean, 57 days). During deployment, women visited clinic (sick call) at significantly higher rates than men: 189 versus 117 visits per week per 1,000 personnel. Except for generally minor gynecological conditions, women and men had similar medical problems. Upper respiratory complaints and requests for contraceptive pills were the most common reasons for clinic visits among women. The majority of sailors felt that they had received appropriate medical care, although fewer women (66%) than men (78%) were satisfied. Levels of cigarette and alcohol use and sexual activity were comparable among women and men and corresponded to those of the general U.S. population of young adults. Because of high levels of health, most medical needs of women sailors can be managed readily by providing routine gynecological care and by minor additions to the shipboard pharmacy.

Adolescent↗
PubMed1997

Human immunodeficiency virus RNA levels in US adults: a comparison based upon race and ethnicity.

Volunteers in a natural history study of human immunodeficiency virus type 1 (HIV-1) at two military medical centers were studied to determine whether plasma HIV-1 RNA levels differ among racial and ethnic groups of US adults infected with HIV-1. Cross-sectional analyses of plasma HIV-1 RNA and CD4 cell counts were done using demographic and clinical data collected during study visits. Age, gender, CD4 cell count, seroconversion status, and use of antiretroviral therapy were studied in 545 military members (46% white, 49% black, and 6% Hispanic). No association was found between HIV-1 RNA levels and race or ethnicity among infected adults for whom access to care and socioeconomic status were not confounding factors.

Adult↗
PubMed1997

Muscle balance at the knee--moment arms for the normal knee and the ACL-minus knee.

Forces, moments and stresses at the knee are dependent upon external and internal loading factors including muscle forces, segmental position and velocity, load carried, and the moment arms (mechanical advantage) of the muscle-tendon units. Requisite to prediction of forces and moments is a detailed understanding of effective moment arms throughout the knee range-of-motion (ROM). Existing muscle models for the knee are based upon limited static studies of only a few preserved specimens. The objectives of this report are to develop a comprehensive description of muscle-tendon moment arms for the normal knee and the anterior cruciate ligament (ACL)-minus knee during flexion-extension motion. Recent research results describe two nonorthogonal, nonintersecting axes of motion for the knee--one describing flexion-extension (FE) and the other longitudinal rotation (LR, equivalent to internal-external rotation). The effective flexion-extension moment arms of the muscles crossing the knee were developed with respect to the FE axis in 15 fresh, hemi-pelvis cadaver specimens. The normal moment arms for each of 13 muscles plus the patellar tendon exhibited variable, yet repeatable and recognizable patterns throughout the ROM. For most muscles there was no significant difference between the normal and ACL-minus moment arms. The results provide a basis for more accurate predictions of joint reaction forces and moments as well as useful knowledge for practitioners and therapists to assist in the assessment of muscle balance at the knee following injury, repair, and throughout rehabilitation.

Adult↗
PubMed1996

Possibilities for unexplained chronic illnesses among reserve units deployed in Operation Desert Shield/Desert Storm.

Because Armed Forces Reserve members, especially combat support units, were rapidly mobilized during Operation Desert Shield/Desert Storm, they were at higher risk for anxiety and stress-related disorders. Personnel in reserve units in the military force structure are at greater risk for psychologic stress due to rapid mobilization and demobilization, which allows minimal time to process adverse experiences or fears. The unexpected disruption of families and careers and resulting financial pressures are magnified in older age groups who have increased personal and family commitments. Personnel in combat support units are at greatest risk when they lack necessary training, cohesion, and leadership. Prevention efforts in reserve units should involve education regarding the potential for activation and associated disruption of family and career plans. Support networks for reserve families should be encouraged. Additional training in an appropriate context regarding risks of biologic and chemical exposure, with the goal of developing confidence in training and equipment, should be stressed. Finally, group processing before demobilization and recall within 90 days of return to emphasize unit cohesion and readjustment to civilian life may be of benefit.

Chronic Disease↗
PubMed1996

Immune response to Shigella sonnei in U.S. Marines.

Pre- and postdeployment serum samples obtained from U.S. marines in Operations Desert Shield and Desert Storm were tested for antibodies to Shigella sonnei. High predeployment levels of immunoglobulin A (IgA) and/or IgG antibodies to S. sonnei lipopolysaccharide antigen in serum and seroconversions were accompanied by higher IgA and/or IgG antibody response to Shigella invasion plasmids (Ipa). The results suggest exposure to S. sonnei in predeployment troops and frequent exposure to this bacterial agent during deployment.

Antibodies, Bacterial↗
PubMed1995

Serum antibody to lipopolysaccharide antigens of Shigella species among U.S. military personnel deployed to Saudi Arabia and Kuwait during Operations Desert Shield and Desert Storm.

During Operations Desert Shield and Desert Storm, U.S. troops were at high risk of diarrheal disease due to Shigella spp., particularly Shigella sonnei. In order to better understand the serologic response to Shigella infection, 830 male U.S. combat troops were evaluated before and after the deployment to Saudi Arabia and Kuwait for immunoglobulin A (IgA) and IgG anti-Shigella lipopolysaccharide (LPS) (antibody to S. sonnei form I and Shigella flexneri serotypes 1a, 2a, and 3a) in serum. Just before deployment, 10.3% of the subjects were seropositive for IgA and 18.3% were positive for IgG anti-Shigella LPS. IgA and IgG anti-LPS antibody levels in serum prior to deployment were significantly associated with nonwhite race and ethnicity, birth outside the United States, and antibody to hepatitis A virus and Helicobacter pylori. During the deployment, which lasted for a mean of 131 days, 60% of the subjects reported at least one episode of diarrhea and 15% reported an episode of diarrhea with feverishness; also, 5.5% of the subjects exhibited IgA seroconversion to Shigella LPS and 14.0% exhibited IgG seroconversion. A significant association between the development of diarrheal symptoms and either positive predeployment anti-LPS antibody or seroconversion was not found. These data indicate that in this population of U.S. Desert Storm troops who were at high risk of Shigella infection, there was no apparent relation between IgA or IgG anti-Shigella LPS in serum and diarrheal disease.

Adolescent↗
PubMed1995

The risk of Helicobacter pylori infection among U.S. military personnel deployed outside the United States.

To determine whether military personnel deployed outside the United States are at increased risk of Helicobacter pylori infection, 1,000 male U.S. Navy and Marine Corps personnel (mean age 22 years) were evaluated. Study subjects included 200 recruits, 500 shipboard personnel deployed for six months to South America, West Africa, and the Mediterranean, and 300 ground troops deployed for five months to Saudi Arabia. Among all 1,000 subjects, 247 (25%) were seropositive for H. pylori IgG antibody by an enzyme-linked immunosorbent assay; 24% of new recruits and 25% of troops who had been on active duty for a mean of four years. The prevalence of H. pylori antibody was higher among subjects who were older, nonwhite, foreign-born, and seropositive for antibody to hepatitis A virus. Among the 601 initially seronegative subjects evaluated before and after a 5-6 month deployment outside the United States, five seroconverted, for a rate of infection of 1.9% per person-year of exposure. As found in other populations in developed countries, these data indicate that among U.S. military personnel a large proportion of H. pylori infections occur before adulthood and infection is related to demographic factors. These preliminary findings also suggest that deployed U.S. military personnel may be at increased risk of H. pylori infection compared with adult populations in developed countries either from exposure in developing countries or from crowding.

Adolescent↗
PubMed1995

Sampling lymph node content of human immunodeficiency virus type 1 nucleic acids and p24 antigen by fine-needle aspiration in early-stage patients.

The potential of lymph node fine-needle aspiration (LNFNA) for sampling viral load was evaluated in excised, peripheral lymph nodes from five patients with early-stage human immunodeficiency virus type 1 HIV-1 disease (asymptomatic, CD4 cells > 300/mm3). The preponderance (> 80%) of viral RNA was within follicular germinal centers as noted by in situ hybridization on lymph node frozen sections (LNFSs) as well as within cohesive groups of 10-20 lymphoid cells (microfragments) in LNFNA preparations. Quantification of cells expressing HIV-1 RNA by in situ hybridization, quantification of HIV-1 gag RNA and gag DNA per 10(5) cells by polymerase chain reaction, and measurement of p24 antigen per 10(5) cells yielded similar values for LNFNA, lymph node mononuclear cells (LNMCs) from tissue homogenates by Ficoll-Hypaque separation, and LNFS. Sampling of lymph node viral load by LNFNA appears to capture viral components associated with both individual expressing cells and follicular germinal centers. Due to the advantages in terms of patients' morbidity, repeatability, and cost, assessment of lymphoid tissue viral load by LNFNA warrants an in vivo feasibility trial as an alternative to lymph node biopsy.

Adult↗
PubMed1994

Drug susceptibility of Mycobacterium tuberculosis isolates from recent Haitian migrants: correlation with clinical response.

Between November 1991 and June 1993, approximately 11,000 Haitian migrants were screened for active tuberculosis and human immunodeficiency virus type 1 (HIV-1) infection at the U.S. Naval Base in Guantánamo Bay, Cuba. Cultures of specimens from 37 of these patients yielded Mycobacterium tuberculosis; eight (22%) of these isolates were resistant to standard medications, including isoniazid (22%), rifampin (0), ethambutol (3%), and streptomycin (3%). Two isolates (5.4%) were resistant to two drugs simultaneously. All but one of 340 patients who were treated for presumptive active tuberculosis and who were followed up for about 1 month had a favorable initial clinical response to a standard four-drug regimen. Among 259 HIV-1-infected patients who had normal findings on screening chest radiographs and who received prophylaxis with isoniazid, there were 1.8 incident cases of active tuberculosis per 100 person-years; this rate was 76% lower than that (reported by others) among HIV-1-infected Haitian patients who were not treated with isoniazid. No serious toxic effects due to standard four-drug regimens or to prophylaxis with isoniazid were observed. These data suggest that standard empirical therapeutic interventions for tuberculosis are adequate and well tolerated in Haitian migrants.

Drug Resistance, Microbial↗