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Biomedical subjects

B J Turner

Publications and source records attributed to B J Turner.

At least 73 records · Page 4Linked to original sources
PubMed1995

A population-based comparison of the clinical course of children and adults with AIDS.

OBJECTIVE: To examine the association of clinical complications and age at diagnosis with survival for a cohort of children and adults with AIDS. DESIGN: A population-based analysis of 734 children and 5584 adults diagnosed with AIDS from 1985 to 1990 in New York State. RESULTS: The initial AIDS-defining diagnoses for 68% of children were lymphoid interstitial pneumonitis or infections specified in the Centers for Disease Control and Prevention's (CDC) pediatric AIDS case definition but not the CDC's 1987 adult AIDS case definition. Of opportunistic infections in both case definitions, Pneumocystis carinii pneumonia (PCP) was the most common initial AIDS diagnosis, occurring in 53% of adults, 47% of children aged < 6 months at diagnosis (n = 122) and 14% aged > or = 6 months at diagnosis (n = 612). Median survival after AIDS diagnosis was 62 months for all children compared with 11 months for adults. For children initially diagnosed with conditions only in the pediatric case definition, median survival ranged from 27 to 62 months compared with less than 12 months for children and adults with PCP. Compared with children aged 6-54 months, the estimated hazards of death for younger and older children were 2.06 [95% confidence interval (CI), 1.48-2.86] and 1.54 (95% CI, 1.10-2.16), respectively. CONCLUSION: Children survived significantly longer than adults after AIDS diagnosis, but their survival varied by age at diagnosis. Differences in the types of common initial AIDS-defining diagnoses appear to contribute to the observed differences in survival.

AIDS-Related Opportunistic Infections↗
PubMed1995

Multiple paternity in the red-eyed treefrog Agalychnis callidryas (Cope).

DNA fingerprinting of tadpoles from two different 'one female-two male' matings of the red-eyed treefrog, Agalychnis callidryas, revealed multiple paternity of offspring. Offspring were assigned paternity based on bands shared with the putative father, but not shared between putative fathers or with the mother. Paternity was split approximately 44/56% and 36/64% in two matings. These results do not support a hypothesis of sperm priority in access to unfertilized eggs by primary males. Multiple paternity may be commonplace in species of anurans with matings by multiple males.

Animals↗
PubMed1994

CD4+ T-lymphocyte measures in the treatment of individuals infected with human immunodeficiency virus type 1. A review for clinical practitioners.

The CD4+ lymphocyte is a major target of the human immunodeficiency virus type 1 (HIV-1). CD4+ T-lymphocyte measures have been used to predict the risk of HIV-1-related complications in diverse populations, to guide management decisions, and to define cases of the acquired immunodeficiency syndrome (AIDS). To examine the role of CD4+ measures in the management and epidemiologic monitoring of HIV-1 infection, we evaluated current literature regarding the accuracy and precision of CD4+ measures and the use of these and other prognostic measures in the care of HIV-1-infected persons. Several studies have reported wide intraindividual and interindividual variability in the absolute CD4+ count, which can detract from its clinical usefulness. Approaches to address this variability include the following: drawing specimens at a similar time of the day; monitoring CD4+ percent that has less variability; following a meticulous laboratory technique; using serial tests to guide management decisions; and retesting after efforts to eliminate transient treatment and clinical factors that can affect the CD4+ count. The expense and limited availability of CD4+ measures also present barriers to widespread use. Other laboratory and clinical factors offer additional prognostic information and have an evolving role in management decisions. CD4+ measures have an important role in HIV-1 clinical care, research, and disease surveillance, but strategies are required to address problems with variability, expense, and availability.

CD4-Positive T-Lymphocytes↗
PubMed1994

Implications of generalists' slow adoption of zidovudine in clinical practice.

BACKGROUND: The lag time for adoption of new acquired immunodeficiency syndrome (AIDS) therapies into the clinical practices of different types of ambulatory care providers can be estimated from patient use of zidovudine therapy during the first few years after approval by the Food and Drug Administration. METHODS: We analyzed receipt of zidovudine therapy from April 1987 through March 1990 by 3643 patients with a diagnosis of AIDS. The study group was continuously enrolled in the New York State Medicaid program for at least 6 months after diagnosis. For each patient, the dominant providers of ambulatory care, receipt of zidovudine therapy, and consultation with a human immunodeficiency virus-AIDS specialist within 6 months after diagnosis were determined from Medicaid claims. AIDS specialists included physicians or clinics specializing in infectious disease or hematology/oncology or specific clinics within designated AIDS centers. RESULTS: In 1987, 55% of those who had an AIDS specialist as their dominant care provider received zidovudine therapy, compared with only 36% of patients with a primary care clinic as their dominant care provider. It was not until 1990, 3 years after approval by the Food and Drug Administration, that the percentage of patients receiving zidovudine therapy (77% to 78%) was comparable for patients of primary care clinics and AIDS specialists. In logistic regression analysis, zidovudine use did not differ between patients of AIDS specialists and patients with other types of dominant providers when the latter group had consulted with an AIDS specialist (adjusted odds ratio, 1.38; 95% confidence interval, 0.99 to 1.95). CONCLUSIONS: In our AIDS study population, there was at least a 3-year lag before patients of primary care clinics received zidovudine therapy at the same rate as patients of AIDS specialists. Conditions such as AIDS with rapid changes in treatment options may require a close relationship between generalists and specialists to increase access to new therapies.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Concerted evolution at the population level: pupfish HindIII satellite DNA sequences.

The canonical monomers (approximately 170 bp) of an abundant (1.9 x 10(6) copies per diploid genome) satellite DNA sequence family in the genome of Cyprinodon variegatus, a "pupfish" that ranges along the Atlantic coast from Cape Cod to central Mexico, are divergent in base sequence in 10 of 12 samples collected from natural populations. The divergence involves substitutions, deletions, and insertions, is marked in scope (mean pairwise sequence similarity = 61.6%; range = 35-95.9%), is largely confined to the 3' half of the monomer, and is not correlated with the distance among collecting sites. Repetitive cloning and direct genomic sequencing experiments failed to detect intrapopulation and intraindividual variation, suggesting high levels of sequence homogeneity within populations. The satellite sequence has therefore undergone "concerted evolution," at the level of the local population. Concerted evolution has previously almost always been discussed in terms of the divergence of species or higher taxa; its intraspecific occurrence apparently has not been reported previously. The generality of the observation is difficult to evaluate, for although satellite DNAs from a large number of organisms have been studied in detail, there appear to be little or no other data on their sequence variation in natural populations. The relationship (if any) between concerted, population level, satellite DNA divergence and the extent of gene flow/genetic isolation among conspecific natural populations remains to be established.

Animals↗
PubMed1994

AIDS specialist versus generalist ambulatory care for advanced HIV infection and impact on hospital use.

We examined patterns of ambulatory care in the year before diagnosis of acquired immune deficiency syndrome (AIDS) for 5,720 persons infected with human immunodeficiency virus (HIV) who were continuously enrolled in the New York State Medicaid program and diagnosed in 1984-90. For 3,175 persons followed > or = 6 months after AIDS, we also examined the change between the year before AIDS diagnosis and the 6 months afterward in the predominant provider who was seen most frequently and at least twice. Approximately 75% of the population had a predominant provider identified. Of this group, 43% of the patients had a generalist as their predominant provider before AIDS diagnosis, falling to only 25% after diagnosis. The proportion with an AIDS specialist predominant provider increased from 22% before AIDS diagnosis to 39% afterward (P < 0.001). Patients with a generalist predominant provider before AIDS diagnosis had higher odds of switching providers and of hospitalization after AIDS diagnosis than patients with an AIDS specialist predominant provider. If generalists are to be encouraged to manage patients with advanced HIV disease, a better understanding of factors contributing to these outcomes is needed.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Patterns of Medicaid expenditures after AIDS diagnosis.

This article examines average monthly Medicaid expenditures after diagnosis of acquired immunodeficiency syndrome (AIDS) for the diagnosis, mid-illness, and death intervals, as well as Kaplan-Meier estimates of expenditures from AIDS diagnosis to death. A clinical severity measure (the Severity Index for Adults with AIDS [SIAA]) designed to be predictive of patient survival was applied to a population of continuously enrolled New York State Medicaid patients who survived at least 6 months after being diagnosed with AIDS. Our findings suggest that groups of more seriously ill patients who appear to have more intense demand for health care services, especially over the diagnosis and mid-illness intervals, can be identified using the SIAA.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Patterns of ambulatory care for AIDS patients, and association with emergency room use.

OBJECTIVE: We examined the association of patterns of ambulatory care for AIDS patients with any use of the emergency room (ER) and the monthly rate of ER visits in the six months after AIDS diagnosis. DATA SOURCES/STUDY SETTING: The study population was obtained from the New York State Medicaid HIV/AIDS Research Data Base and includes patients diagnosed with AIDS from 1983 to 1990. DATA COLLECTION/EXTRACTION METHODS: To examine patterns of care and ER use not leading to hospitalization, we studied patients who survived at least six months after their first AIDS-defining diagnosis. The data base included person level information on visits to different provider sites and patient demographic and clinical characteristics. STUDY DESIGN: We defined the dominant provider as the site delivering the majority of ambulatory care for patients with a minimum of four ambulatory visits in the six months after AIDS diagnosis. Dominant providers were classified by specialty and setting: generalist physician; general medicine clinic; AIDS specialty clinic; and other specialty clinic or physician (e.g., cardiology). Patients without a dominant provider were grouped into those with four or more visits and those with fewer than four visits. Regression analysis was used to estimate relationships between ER use and patterns of ambulatory care and patient demographic and severity of illness characteristics. PRINCIPAL RESULTS: The study population included 9,155 AIDS patients aged 13 to 60 years at diagnosis, continuously Medicaid-enrolled, and surviving at least six months after AIDS diagnosis. Among those with four or more visits (56 percent), over 70 percent had a dominant provider. Overall, 39 percent of the study population visited the ER while, in the group with four or more visits, 53 percent of those without a dominant provider had an ER visit. Patients without a dominant provider were estimated to have 32 percent higher odds of ER use than patients with a dominant provider. Among patients with a dominant provider, patients with a generalist or primary care clinic dominant site of care were estimated respectively to have 18 percent and 23 percent lower odds than patients with an AIDS specialty clinic as the dominant site of care. Drug users had higher odds of ER use, as did women. CONCLUSIONS: In this Medicaid AIDS population, a dominant provider delivering the majority of a patient's care was associated with less use of the ER by the patient. Among patients with a dominant provider, ER use was lowest for those with a primary care provider. Further examination of the type and availability of ambulatory services in AIDS specialty clinics and primary care settings, as well as more detailed information on patient characteristics, may reveal reasons for these patterns of ER use.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Health care delivery, zidovudine use, and survival of women and men with AIDS.

The aim of this study was to define predictors of survival for women and men after AIDS diagnosis. We examined health care delivery and drug therapy in the year before AIDS diagnosis for continuously enrolled New York State Medicaid beneficiaries with AIDS in 1988-1990. We examined the association of these factors with survival after AIDS diagnosis. Of 1,077 women and 1,871 men, 60% of both gender groups were drug users. In both risk groups, women had more outpatient visits than men but were equally likely to visit an AIDS specialist. In those who were not drug users, men were twice as likely as women to receive either zidovudine or Pneumocystis carinii pneumonia prophylaxis. No difference appeared among drug users. Survival after AIDS diagnosis was similar by gender for those who were not drug users (RR = 1.09; 95% CI = 0.90-1.33). In drug users, women had a slightly lower risk of death than men (RR = 0.84; 95% CI = 0.72-0.98). Risk of death after AIDS diagnosis was higher for persons starting zidovudine earlier in both risk groups. Among drug users, women received more ambulatory care and survived slightly longer than men. Among those who were not drug users, survival was similar by gender even after adjusting for differences in care.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Randomly amplified polymorphic DNA markers are superior to somatic incompatibility tests for discriminating genotypes in natural populations of the ectomycorrhizal fungus Suillus granulatus.

Assessing genetic variation within populations and genetic exchange between populations requires an understanding of the distribution and abundance of individual genotypes within the population. Previous workers have used somatic incompatibility testing to distinguish clones or individuals in natural populations of ectomycorrhizal fungi. However, somatic incompatibility tests performed with isolates of Suillus granulatus from a natural population revealed a lack of transitiveness, which brought into question the validity of this method. Subsequent studies of genetic identity of these isolates, using randomly amplified polymorphic DNA (RAPD) markers, conclusively showed that somatically compatible isolates are not necessarily genetically identical. RAPD marker analysis is more reliable and provides higher resolution of genotype distribution in natural populations than does somatic incompatibility testing. This is of particular importance in populations of organisms such as ectomycorrhizal fungi in which the mating systems are incompletely known.

Journal Article↗
PubMed1993

Survival experience of 789 children with the acquired immunodeficiency syndrome.

To define predictors of survival we studied longitudinal histories of 789 New York State Medicaid-enrolled children diagnosed with acquired immunodeficiency syndrome (AIDS) from 1983 to 1989 and followed through 1990. Median survival times for 3 severity groups of AIDS-defining conditions were 66, 48 and 9 months. In a proportional hazards model, the relative risk of death for the most vs. least severe group was 3.33 (95% confidence interval, 2.53, 4.37) and the relative risk for children < 6 months old at diagnosis vs. older children was 1.81 (95% confidence interval, 1.41, 2.34). We increased our ability to predict death by using a 4-category severity index that assesses both the AIDS-defining diagnosis and clinical complications within 3 months of diagnosis (relative risk, 5.27; 95% confidence interval, 3.16, 8.78 for most vs. least severe). These analyses offer new clinical severity measures and reveal that, regardless of the AIDS-defining diagnosis, children with AIDS who are < 6 months old have a poor prognosis.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Extreme clonal diversity and divergence in populations of a selfing hermaphroditic fish.

Recombination is unknown in natural populations of Rivulus marmoratus, a selfing hermaphrodite, and genetic variation is likely due to mutation alone. DNA fingerprinting with an array of microsatellite [e.g., (CT)9] and minisatellite (e.g., the 33.15 core sequence) probes reveals very high clonal diversity within samples of seven Floridian populations, of which five contain about as many clones as there are individuals. There are 42 clones among 58 individuals surveyed (mean, 1.4 individuals per clone), a level of genetic diversity unprecedented among clonal animals. Moreover, all of the probes recognize the same clones even though, at high hybridization stringencies, there is little overlap in the fingerprint patterns they generate. This suggests that most sympatric clones differ by multiple and independent mutational steps. In one population studied in detail, the average number of mutational steps separating two clones is estimated at 9 or 10 and may be substantially higher. The mutational discontinuities among sympatric clones make it unlikely that they evolved by accumulation of neutral mutations in populations that are otherwise genetically uniform. The data argue that the mixing of unrelated individuals from different local populations occurs to an extent previously unappreciated and/or that divergence of clones is mediated by natural selection. If confirmed, the latter would be a serious challenge to current ideas on the predominant role of recombination in promoting the evolution of biological novelty.

Animals↗
PubMed1992

Who is providing ambulatory care to Medicaid beneficiaries with acquired immunodeficiency syndrome in New York State?

This study examined the number of ambulatory care providers treating individuals with the acquired immunodeficiency syndrome who were Medicaid beneficiaries in New York State in 1988 and examined the distribution of this care across various practice settings. The study population was identified retrospectively in the New York State Medical HIV/AIDS Research Data Base and included a cohort of 5535 individuals with the acquired immunodeficiency syndrome who were enrolled in Medicaid in 1988 for at least 6 months after being diagnosed as having the disease and who had at least one ambulatory care encounter during the year. Ambulatory care for the study group was provided by more than 700 hospital or freestanding clinics and more than 3000 private physicians in 1988. Many sites had low caseloads; 47% of the clinics and 68% of the physicians treating this population saw only one or two patients with the acquired immunodeficiency syndrome who were enrolled in Medicaid. More than half the patients in the study group were seen most frequently in clinics for their ambulatory care during 1988. These data provide reassurance that a wide network of providers is involved in the care of patients with the acquired immunodeficiency syndrome who are Medicaid beneficiaries in New York.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Duration of Medicaid AIDS hospitalizations--variation by season, stage, and year.

Using New York State Medicaid data from 1984 to 1987, we analyzed hospital length-of-stay patterns for acquired immunodeficiency syndrome (AIDS) patients. We found an overall decline in monthly average length of stay, with seasonal fluctuations producing longer stays in the fall and winter months. These findings suggest that hospital utilization for AIDS patients is changing over time and may vary by season.

Abstracting and Indexing↗
PubMed1992

Variations in inpatient mortality for AIDS in a national sample of hospitals.

In this project, we examined the spectrum of AIDS-related conditions and variations in associated inpatient mortality for AIDS patients treated in a national sample of hospitals. We identified 10,538 adult discharges with a diagnosis indicating AIDS from 258 hospitals from a national sample of 438 acute-care hospitals with 6 million discharges in 1986-1987. Opportunistic and other infections occurred in 55.9 and 37.9%, respectively, of AIDS discharges, and inpatient fatality rates varied considerably depending on complication type(s) and comorbidities. Clinical conditions were more important predictors of inpatient death than demographic or treatment site characteristics. Among opportunistic infections, odds of inpatient death were significantly increased for progressive multifocal leukoencephalopathy (odds ratio [OR] = 2.8), Pneumocystis carinii pneumonia (OR = 2.4), cryptococcosis (OR = 1.6), atypical mycobacterial infections (OR = 1.6), and toxoplasmosis (OR = 1.3). Odds of inpatient death were also significantly increased by non-AIDS-defining infections causing septicemia (OR = 3.1) or CNS involvement (OR = 1.6) or pulmonary involvement (OR = 1.5). After controlling for clinical conditions, significant differences in odds of death persisted across regions, age, and ethnic groups. Increases in hospitals' AIDS treatment experience were associated with a significant decrease in odds of inpatient death. These analyses provide a national perspective on the diversity of AIDS-related clinical conditions and their relative effects on inpatient mortality.

AIDS-Related Opportunistic Infections↗
PubMed1991

The AIDS-defining diagnosis and subsequent complications: a survival-based severity index.

To define a survival-based severity measure for AIDS, we convened a panel of AIDS experts who identified factors influencing AIDS prognosis and estimated the impact of prognostic factors on survival time. The resulting conceptual model included 19 AIDS-defining conditions and 80 subsequent AIDS-related complications. This model was tested on longitudinal disease histories of 3,937 AIDS patients in the New York State Medicaid Program diagnosed between 1983 and 1986 and followed through 1988. The initial AIDS diagnosis and complications within 3 months of AIDS onset were identified from coded diagnoses recorded on inpatient and outpatient claims. Three AIDS-defining diagnosis groups were created; survival times from least to most severe group were 25, 10, and 7 months. To determine the influence of subsequent complications on risk of death, the survival times associated with combinations of defining diagnosis groups and four severity levels of subsequent complications were determined. Median survival ranged from 43 months for the least severe defining diagnosis group without early complications to 12 months for the group with severe defining diagnoses and serious complications. The matrix of AIDS-defining diagnoses and complications was divided into four severity categories with significantly different survival curves. This severity measure uses longitudinal data commonly available to clinicians and researchers to create distinct AIDS prognostic categories.

Acquired Immunodeficiency Syndrome↗