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Biomedical subjects

Richard Long

Publications and source records attributed to Richard Long.

14 recordsLinked to original sources
PubMed2005

Tuberculosis: still overlooked as a cause of community-acquired pneumonia--how not to miss it.

Tuberculosis (TB) is often mistaken for community-acquired pneumonia (CAP). To avoid missing the diagnosis, we recommend that any CAP patient with upper lobe infiltrate, cavitation, miliary pattern, hemoptysis or >1 month of any of cough, fever, malaise,weakness, night sweats, or significant weight loss, should have sputa submitted for Mycobacterium tuberculosis smear and culture. Any CAP patient failing or relapsing after empiric therapy should be investigated for TB. In the presence of HIV with low CD4 count (< or = 200 cells/mL), the presentation may be atypical, and therefore sputa should be submitted for M tuberculosis. Any HIV patient, regardless of CD4 count, with a known history of positive tuberculin skin test, previous TB, or recent exposure to TB, who presents with CAP, should be investigated for TB.

Adult↗
PubMed2005

Inhaled nitric oxide treatment of patients with pulmonary tuberculosis evidenced by positive sputum smears.

Endogenous nitric oxide (NO) has antimycobacterial properties. We tested the hypothesis that exogenous (inhaled) NO can be safely delivered and can accelerate airway disinfection for pulmonary tuberculosis patients treated with standard therapy. Exogenous NO administered at 80 ppm for 72 h can be safely delivered but does not accelerate airway disinfection.

Administration, Inhalation↗
PubMed2005

Blind and sighted pedestrians' judgments of gaps in traffic at roundabouts.

This paper reports two experiments about street crossing under conditions of free flowing traffic, with a focus on modem roundabout intersections. Experiment 1 was conducted at three roundabouts varying in size and traffic volume. Six totally blind and six sighted adults judged whether gaps in traffic were long enough to permit crossing to the median (splitter) island before the next vehicle arrived. Gap distributions and measures of judgment quality are reported. Overall, blind participants were about 2.5 times less likely to make correct judgments than sighted participants, took longer to detect crossable gaps, and were more likely to miss crossable gaps altogether. However, the differences were significant only at the two higher volume roundabouts. In Experiment 2, we evaluated the response of drivers to pedestrians with and without mobility devices (i.e., long canes, dog guides). The experiment was conducted at a single-lane roundabout, a midblock crossing, and a two-way-stop-controlled intersection. Site-specific characteristics appeared to have a greater impact on drivers' yielding than did a mobility device. Actual or potential applications of this research include the development of methods for assessing pedestrian safety and driver behavior as well as identifying intersections that may require modification in order to be accessible to blind pedestrians.

Accidents, Traffic↗
PubMed2003

Anti-tumour necrosis factor agents and tuberculosis risk: mechanisms of action and clinical management.

Cases of active tuberculosis have been reported worldwide with the use of therapeutic agents that inhibit tumour necrosis factor (TNF) alpha. TNFalpha has a central role in mycobacterial infection and disease. Accordingly, progression of recently acquired tuberculosis infection or reactivation of remotely acquired infection should be expected with the use of anti-TNF agents. The available in-vitro and epidemiological evidence for the two currently approved agents, infliximab and etanercept, shows that the risk of development of active tuberculosis is greater with infliximab. Tuberculin skin testing (TST) should be undertaken before any significant immunosuppressive therapy including these agents, though the possibility of false-negative reactions in immunocompromised populations must be borne in mind. A positive TST should be followed by medical assessment and chest radiography, as well as by other tests judged appropriate by the physician to identify active disease. Active tuberculosis must be treated appropriately before initiation of treatment with an anti-TNF agent. Treatment of latent tuberculosis can be considered on an individual basis for TST-negative patients receiving anti-TNF agents when significant risk factors for infection are present.

Algorithms↗
PubMed2003

Relative versus absolute noncontagiousness of respiratory tuberculosis on treatment.

OBJECTIVE: To assess the validity of current estimates of the noncontagiousness of sputum smear-positive respiratory tuberculosis (TB) on treatment. DESIGN: A descriptive analysis of the mycobacteriologic response to treatment. SETTING: A TB inpatient unit of a Canadian hospital. PATIENTS: Thirty-two HIV-seronegative patients with moderate to advanced sputum smear-positive respiratory TB were treated with uninterrupted, directly observed, weight-adjusted isoniazid, rifampin, and pyrazinamide. Each patient's initial isolate was drug susceptible and each patient's sputum mycobacteriology was systematically followed until 3 consecutive sputum smears were negative on 3 separate days. RESULTS: The time to smear conversion varied remarkably (range, 8 to 115 days; average, 46 days) and was influenced by sputum sampling frequency. Only 3 patients (9.4%) had smear conversions by 14 days and only 8 (25%) had smear conversions by 21 days, the average time it took for drug susceptibility test results to become available. During the first 21 days of treatment, the semiquantitative sputum smear score decreased rapidly and the time to detection of positive cultures doubled. Within the time to smear conversion, virtually all smear-positive specimens (98%) were culture positive and only 34% of the patients had culture conversions (ie, 3 consecutive negative cultures). CONCLUSION: Current estimates of the noncontagiousness of sputum smear-positive respiratory TB on treatment (for 14 days, for 21 days, or until smear conversion) are estimates of relative noncontagiousness. They do not signal absolute noncontagiousness (culture conversion). Semiquantitative smear and time-to-detection data suggest that respiratory isolation beyond 21 days of optimal treatment should be selective.

Academic Medical Centers↗
PubMedDate not supplied

Tuberculosis control in Alberta. A federal, provincial and regional public health partnership.

The number of cases of tuberculosis in Alberta or Canada may not be large, but the public health and medical costs of just a few cases can be prohibitive. For example, the costs of managing cases of multidrug-resistant tuberculosis and their contacts, can exceed the entire annual budget of a program. This was evident in New York City in the late 1980s and early 1990s, when $1 billion in public funds were spent reversing a major resurgence of drug-resistant and susceptible tuberculosis. In Canada, the Walkerton Inquiry has identified an apparent failure of provincial public policy to adequately address public health needs. This has resulted in decreased public confidence and potential liabilities for the policy-makers. In the design of the Tuberculosis Control Program of Alberta, the notion of a quasicentralized or quasidecentralized program is rejected. Rather there is an appeal to the notion of a partnership of responsibility that recognizes jurisdictional and non-jurisdictional public health, case management and epidemiologic realities, the integral contribution of each level of government and the need to be accountable to the public's health and purse. For levels of government not to properly discharge their responsibilities may be perceived as an abrogation of the public trust and a disregard of the Tuberculosis Control Policy Package and operational directives of the World Health Organization.

Alberta↗
PubMedDate not supplied

Pediatric tuberculosis in Alberta First Nations (1991-2000): outbreaks and the protective effect of bacille Calmette-Guérin (BCG) vaccine.

BACKGROUND: The tuberculosis control strategy of vaccinating First Nations newborns with BCG (bacille Calmette-Guerin) is currently undergoing re-evaluation in Canada. Review of recent pediatric tuberculosis morbidity could inform this re-evaluation. METHODS: Potential source cases and pediatric cases of tuberculosis from Alberta First Nations were identified over the 10 years 1991-2000. The distribution of pediatric disease was described. The effect of BCG on tuberculosis morbidity in two large outbreaks was determined. RESULTS: A total of 57 potential source cases and 41 pediatric cases of tuberculosis were reported from 17 (41.5%) and 8 (19.5%) of the 41 on-reserve First Nation Community Health Centres, respectively. Three outbreaks traceable to three source cases accounted for 34 (18, 3, and 13, respectively) of the 41 (82.9%) pediatric cases. Each outbreak was spatially and temporally separate from the other. Each outbreak strain of Mycobacterium tuberculosis had a unique DNA fingerprint. In the largest outbreaks, disease-to-infection ratios (secondary case rates) were higher in newly infected unvaccinated versus vaccinated close pediatric contacts (12/13 [92.3%] versus 7/15 [46.7%], p=0.02), but the infection rate was almost certainly falsely high in the BCG vaccinated. One unvaccinated child had a brain tuberculoma in addition to primary pulmonary tuberculosis. CONCLUSION: For most Alberta First Nations communities, the spatial and temporal distribution of disease, and the meager impact on morbidity, challenge the rationale for continued use of BCG.

Adjuvants, Immunologic↗