Biomedical subjects

Douglas Wilson

Publications and source records attributed to Douglas Wilson.

12 recordsLinked to original sources

PubMed2006

Adherence with isoniazid for prevention of tuberculosis among HIV-infected adults in South Africa.

BACKGROUND: Tuberculosis (TB) is the most common opportunistic infection in HIV-infected adults in developing countries. Isoniazid (INH) is recommended for treatment of latent TB infection, however non-adherence is common. The purpose of this study was to apply in-house prepared isoniazid (INH) urine test strips in a clinical setting, and identify predictors of positive test results in an adherence questionnaire in HIV-infected adults taking INH for prevention of TB. METHODS: Cross-sectional study of adherence using a questionnaire and urine test strips for detection of INH metabolites at two hospitals in Pietermaritzburg, South Africa. Participants were aged at least 18 years, HIV positive, and receiving INH for prevention of tuberculosis disease. Univariate and multivariate analyses are used to identify factors relevant to adherence. RESULTS: 301 consecutive patients were recruited. 28% of participants had negative urine tests. 32 (37.2%, 95% CI25.4, 45.0) of the 86 patients who received INH from peripheral pharmacies said the pharmacy had run out of INH at some time, compared with central hospital pharmacies (p = 0.0001). In univariate analysis, a negative test was associated with self-reported missed INH doses (p = 0.043). Each 12-hour increment since last reported dose increased the likelihood of a negative test by 34% (p = 0.0007). Belief in INH safety was associated with a positive test (p = 0.021). In multivariate analysis, patients who believed INH is important for prevention of TB disease were more likely to be negative (p = 0.0086). CONCLUSION: Adequate drug availability at peripheral pharmacies remains an important intervention for TB prevention. Key questions may identify potentially non-adherent patients. In-house prepared urine tests strips are an effective and cheap method of objectively assessing INH adherence, and could be used an important tool in TB control programs.

AIDS-Related Opportunistic Infections↗

PubMed2005

Low-income Canadians' experiences with health-related services: implications for health care reform.

This study investigated the use of health-related services by low-income Canadians living in two large cities, Edmonton and Toronto. Interview data collected from low-income people, service providers and managers, advocacy group representatives, and senior-level public servants were analyzed using thematic content analysis. Findings indicate that, in addition to health care policies and programs, a broad range of policies, programs, and services relating to income security, recreation, and housing influence the ability of low-income Canadians to attain, maintain, and enhance their health. Furthermore, the manner in which health-related services are delivered plays a key role in low-income people's service-use decisions. We conclude the paper with a discussion of the health and social policy implications of the findings, which are particularly relevant within the context of recent health care reform discussions in Canada.

Alberta↗

PubMed2005

Physicians' perceptions of integration in three Western Canada Health Regions.

Over the post decade, provincial governments have embarked on ambitious plans to better integrate their healthcare systems, through the introduction of regional governance and management structures. The objective of this study was to examine physicians' perceptions of the current level and facilitators/barriers to integration in three Western Canada Health Regions. Three approaches to integration were investigated: functional, clinical services, and physician system integration. Physicians perceived that functional integration within each region was questionable. Clinical services were the least integrated approach. Physician system integration was rated highest of the approaches, particularly adherence to clinical practice guidelines usage. Physicians' perspectives of integrated health delivery systems do not appear to be influenced by regional size, maturity, urbanicity or facilities. Facilitators of integration were communication among health professionals and service providers, and using a multi-disciplinary team approach in delivery of healthcare in both regions. Barriers to integration were organizational culture, access to specialists and clinical services, and health information records. On a scale of 1-5, all three regions are at the beginning of an integrated health delivery system. Three global suggestions were provided to further integration of health delivery services: physicians should be involved in decision-making process at the Board level, clinical services should be patient-centred, and physicians endorsed the use of multi-disciplinary teams.

British Columbia↗

PubMed2005

A comparison of wet-dry swabbing and excision sampling methods for microbiological testing of bovine, porcine, and ovine carcasses at red meat slaughterhouses.

A comparison of wet-dry swabbing and surface tissue excision of carcasses by coring was undertaken. Samples from 1,352 bovine, 188 ovine, and 176 porcine carcasses were collected from 70 separate visits to commercial slaughterhouses operating under normal conditions. The mean total aerobic viable bacterial counts (TVCs) for all species sampled by excision was 5.36 log units, which was significantly greater than the 4.35 log units measured for swabbing. Poorly correlated linear relationships between swab- and excision-derived bacterial numbers from near-adjacent carcasses were observed for all three animal species. R2 values for least squares regressions for bovine, ovine, and porcine carcasses were 0.09, 0.27, and 0.21, respectively. The reasons why it was not possible to calculate a factor that allowed the interconversion of bacterial numbers between samples collected by each sampling method were investigated. Uncertainty associated with laboratory analyses was a contributing factor because the geometric relative standard deviations measured for TVCs were 0.174 and 0.414 for excision and swabbing, respectively. Uneven distribution of bacteria at identical sampling sites on near-adjacent carcasses on processing lines was also a contributory factor. The implications of these findings for process control verification were investigated by intensive sampling for 13 weeks in three commercial slaughterhouses. As many as 4 log units of difference in TVCs were observed in duplicate samples collected within a narrow timeframe from near-adjacent carcasses on the processing line. We conclude that it might not be appropriate to institute corrective actions in slaughterhouses on the basis of a single week's test results.

Abattoirs↗

PubMed2004

About 21-year hale cyclic signature in agriculture complement those in biomedicine.

Data on total cultivated area and total production of wheat and rye, barley and two-row barley, corn, soya and sunflower in Romania (1968-2000) are re-analyzed from the viewpoint of chronomics. An about 10.7-year component is detected with borderline statistical significance. A 3-component model consisting of cosine curves, with periods of 3.62, 2.48 and 2.15 years, accounts for 27% of the overall variability. Transdisciplinary chronomics is advocated to systematically map predictable dynamics in agriculture such as Hale-like cycles in corn and soja and their interactions with chronomes of external environmental factors.

Agriculture↗

PubMed2003

Preliminary analysis of polyhydroxyalkanoate inclusions using atomic force microscopy.

Atomic force microscopy analysis of polyhydroxyalkanoate (PHA) inclusions isolated from sonicated Ralstonia eutropha cells revealed that they exhibit two types of surface structure and shape; rough and ovoid, or smooth and spherical. Smooth inclusions possessed linear surface structures that were in parallel arrays with 7-nm spacing. Occasionally, cracks or fissures could be seen on the surface of the rough inclusions, which allowed a measurement of approximately 4 nm for the thickness of the boundary layer. When the rough inclusions were imaged at higher resolution, globular structures, 35 nm in diameter, having a central pore could be seen. These globular structures were connected by a network of 4-nm-wide linear structures. When the inclusions were treated with sodium lauryl sulfate, the boundary layer of the inclusion deteriorated in a manner that would be consistent with a lipid envelope. When the boundary layer was largely gone, 35-nm globular disks could be imaged laying on the surface of the filter beside the inclusions. These data have facilitated the development of a preliminary model for PHA inclusion structure that is more advanced than previous models.

Cupriavidus necator↗

PubMed2003

Circasemiannual chronomics: half-yearly biospheric changes in their own right and as a circannual waveform.

Geomagnetic activity has a strong half-yearly but no precise yearly component in its spectrum, as Armin Grafe suggested nearly half a century ago. We have postulated elsewhere that non-photic cycles such as those in geomagnetics may have signatures in the biosphere and vice versa that biological rhythms have likely counterparts in the physical environment. Accordingly, we document phenomena characterized by a prominent about half-yearly variation, re-analyzed to constitute the start of a transdisciplinary chronomic (time structural) map, aligning these conditions with a half-yearly cycle in the geomagnetic index Kp. At least some biospheric phenomena fitted concomitantly with 1- and 0.5-year cosine curves exhibit an amplitude (A) ratio of A(0.5-year)/A(1-year) larger than unity. Methodologically, it is pertinent that even if data were read off published graphs, the resulting analyses were practically the same as those in the original data received subsequently. The main point is a circasemiannual pattern in status epilepticus, in several morbid oral conditions, in the cell density of vasopressin-containing neurons in the human suprachiasmatic nuclei (SCN), in circulating melatonin at middle latitudes at night during years of minimal solar activity or around noon at high latitudes, and in an unusual circasemiannual aspect of a birth-month-dependence of human longevity. Others have asked whether annual rhythms in human reproduction are biological, sociological or both. We show some other possibilities herein, involving the physical environment, hardly to be neglected in the case of open systems. As to almost certainly multifactorial circasemiannual rhythms, geomagnetics may also be a signal, a proxy or a putative, at least partial mechanism. Geomagnetic activity is related in its turn to solar and galactic activity, and may be a marker for other cyclic events that affect the biosphere. The similarity of cycle lengths in itself can only be a hint prompting the search for causal relations.

Atmosphere↗

PubMed2003

Pediatric critical care medicine: planning for our research future.

OBJECTIVE: To introduce to the pediatric critical care medicine community a new program in pediatric critical care medicine at the National Institutes of Health. DATA SOURCE: Summary of literature review and conference proceedings. DATA SYNTHESIS: At the National Institute of Child Health and Human Development (NICHD), a new program in pediatric critical care and rehabilitation research has been established in the National Center for Medical Rehabilitation Research. The program is directed by a pediatric intensivist and is focused on developing research directed toward improving long-term outcomes in pediatric critical care and on incorporating pediatric rehabilitation medicine as a partner in this goal. To provide strategic direction for the new program, the NICHD sponsored a planning conference May 3-4, 2002, at the NICHD in Bethesda, MD. The conference invitees represented a broad range of pediatric critical care medicine clinical and research interests, expertise, and career stages. It also included individuals with expertise in rehabilitation research. CONCLUSION: The composition of the new program, including its link to physical medicine and rehabilitation, is discussed. In addition, recommendations by the conference participants and program director are provided to foster the development of more randomized, controlled clinical trials and to develop successful clinician scientists in pediatric critical care medicine.

Child↗

PubMed2003

Promoting participation: evaluation of a health promotion program for low income seniors.

This article describes a qualitative evaluation of the Seniors Active Living in Vulnerable Elders (ALIVE) program, a 10-month health promotion program for low income seniors. Program interventions delivered in seniors' apartment buildings included exercise classes, health information sessions (i.e., health corners), and newsletters. The evaluation examined program participation, program impacts, and how the program worked. The most frequent reason for joining the program was recognizing the benefits of exercise, and the most frequent reason for not attending the program was having other priorities. The main participant impact was "feeling better." Specific impacts were also noted in physical, mental, and social domains. Fun, program delivery adaptations, autonomy, social interactions, and staff-participant relationships were discovered to be important program processes. These processes all contributed to participant's "comfort" in the program. How and why the program worked is examined in relation to Pender's (1996) revised health promotion model and implications for nursing are indicated.

Aged↗

PubMed2002

Effect of highly active antiretroviral therapy on incidence of tuberculosis in South Africa: a cohort study.

BACKGROUND: Studies of the effect of highly active antiretroviral therapy (HAART) on the risk of HIV-1-associated tuberculosis have had variable results. We set out to determine the effect of HAART on the risk of tuberculosis in South Africa. METHODS: We compared the risk of tuberculosis in 264 patients who received HAART in phase III clinical trials and a prospective cohort of 770 non-HAART patients who were attending Somerset Hospital adult HIV clinic, University of Cape Town, between 1992 and 2001. Poisson regression models were fitted to determine risk of tuberculosis; patients were stratified by CD4 count, WHO clinical stage, and socioeconomic status. FINDINGS: HAART was associated with a lower incidence of tuberculosis (2.4 vs 9.7 cases per 100 patient-years, adjusted rate ratio 0.19 [95% CI 0.9-0 38]; p<0.0001). This finding was apparent across all strata of socioeconomic status, baseline WHO stage, and CD4 count, except in patients with CD4 counts of more than 350 cells/microL. The number of tuberculosis cases averted by HAART was greatest in patients with WHO stage 3 or 4 (18.8 averted cases per 100 patient-years, adjusted rate ratio 0. 22 [0.09-0.41]; p=0.03) and in those with CD4 counts of less than 200 cells/microL (14.2 averted cases per 100 patient-years, adjusted rate ratio 0.18 [0.07-0.47]; p,0.0001). INTERPRETATION: HAART reduced the incidence of HIV-1-associated tuberculosis by more than 80% (95% CI 62-91) in an area endemic with tuberculosis and HIV-1. The protective effect of HAART was greatest in symptomatic patients and those with advanced immune suppression.

AIDS-Related Opportunistic Infections↗

PubMed2002

System times and time horizons for biospheric near-matches of primarily non-photic environmental cycles.

System time is defined as the duration (T) and sampling density (deltat) of a given study. A time horizon is obtained by combining analytical results on endpoints of time structures (chronomes), usually on control groups, from accumulating diverse studies carried out with drastically different values of T and deltat. These two design considerations depend upon and are limited by resources. The desideratum of a small At e.g., for studies of chaotic endpoints, limits T, e.g., has thus far precluded a continuous mapping of decadal cycles in endpoints such as the approximate entropy or the correlation dimension. Time horizons are being documented for an increasing number of variables that undergo cycles with infra-annual frequencies - with one cycle in about one, two and/or five decades - in the biosphere as in the environment. These infra-annuals, in and around us, modulate ultra-annuals, including circadians, as well as about 7-day (circaseptan) and about half-yearly (circasemiannual) cycles, all prominent, e.g., in geophysical and biospheric specta. Neglect of infra-annual chronomics can lead to blunders. A statistically highly significant decrease in the excretion of steroidal metabolites (or in heart rate variability) may be misinterpreted as premature aging if it lasts for several years, and may be unnecessarily acted upon, e.g., by drugs. The decrease, however, may only be transient, occurring only during a given stage of a circadecadal cycle, and it may be followed for the next several years by an also spurious "rejuvenation", possibly misinterpreted as a drug effect. When recognized as the alternating stages of decadal cycles and assessed with an affordable deltat, infra-annuals of variables involved in major problems of our day, including homicides and wars, may lead us to manipulable internal or external mechanisms, and thus, eventually, possibly to countermeasures to crime and terror as well as to the optimization of aims such as spirituality.

Circadian Rhythm↗

PubMed2002

Pharmacokinetic and pharmacodynamic modeling of humanized anti-factor IX antibody (SB 249417) in humans.

BACKGROUND: SB 249417 is a humanized anti-factor IX/IXa antibody that, on administration to rats and monkeys, produces an immediate suppression of factor IX activity and prolongation of activated partial thromboplastin times (aPTT). OBJECTIVE: Our objective was to establish the pharmacokinetics of SB 249417 and to explore its effects on factor IX activity levels and aPTT in humans. METHODS: In this phase I, single-blind, randomized, placebo-controlled, parallel-group, single intravenous infusion study, individual and mean data from a total of 26 healthy volunteers at 5 dosing levels were analyzed. A 2-compartment pharmacokinetic model was used in the analysis of total SB 249417 concentration-time profiles. A modified indirect-response model was used, with the total concentration indirectly serving as the driving force for the suppression of free factor IX concentration (as assessed by factor IX activity). The aPTT was related to factor IX activity with a biexponential equation, and a population approach was used to generate posterior parameter estimates for the individual fittings. RESULTS: Mean parameter estimates from individual fittings are 0.092 L/kg for volume of distribution, 0.15 L/kg for steady-state volume of distribution, and 0.0021 L/kg per hour for systemic clearance. The model described well the factor IX activity and aPTT time course in response to SB 249417 at 5 dose levels. The estimated half-life of factor IX in blood was 21 hours. CONCLUSIONS: This model was stable and robust in fitting both mean and individual data. Endogenous factor IX baseline levels and dose were the major determinants of the decline in factor IX activity during the infusion period. Thereafter the recovery of factor IX activity was governed solely by the endogenous factor IX turnover rate.

Adult↗