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Biomedical subjects

James W Smith

Publications and source records attributed to James W Smith.

17 recordsLinked to original sources
PubMed2006

The future of automated red blood cell collection.

Automated red blood cell (RBC) collection is a newer but well-established form of donor apheresis. The technologies comprising and supporting apheresis have undergone significant advancements through the past 50 years, and we anticipate further improvements in devices and systems for automated RBC collection. Multiple factors must be considered in implementing automated RBC collections, but these procedures provide a way to draw additional RBC products that meet cGMP, regulatory, blood collector economic and donor objectives while maintaining or improving RBC availability. The continuing need for RBCs, accompanied by shrinking donor availability, would indicate that automated RBC collections will grow.

Automation↗
PubMed2006

Factors influencing the decision to donate: racial and ethnic comparisons.

BACKGROUND: Understanding factors that encourage different racial and ethnic groups to donate is crucial for donor recruitment and retention. STUDY DESIGN AND METHODS: A 28-item self-administered questionnaire was completed in 2003 by 1862 Asian, 1479 black, 1641 Hispanic, and 2940 White US donors who had given whole blood within the past year. With a 1 to 5 scale, donors were asked to rate the importance of 17 factors in their last donation decision. Logistic regression was conducted to compare the odds of a factor being important or very important (score of 4 or 5) in one's decision to donate between race or ethnic groups, stratified by first-time and repeat status. RESULTS: More than 90 percent of each respondent group cited a desire, responsibility, or perceived duty to help others as an important or very important motivator. Being asked to donate at work was also an important motivator for all race and ethnic groups (56-70%). Getting the results of a health screen appealed to many (approx. 30% found it important or very important) and was most important to Black and Hispanic donors (odds ratios of 1.3-1.9 compared to White donors; p<0.003). CONCLUSION: Recruitment and retention programs should build on people's sense of social responsibility. Direct requests to donate are particularly effective motivators. Of a variety of incentives evaluated, offering more comprehensive health screens may motivate many donors, especially Black and Hispanic donors.

Adult↗
PubMed2005

Effects of switching pravastatin to cerivastatin on C-reactive protein, butyrylcholinesterase, and lipids.

OBJECTIVE: C-reactive protein (CRP) concentrations, butyrylcholinesterase (BChE) activity, total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides (TG) were evaluated in patients switched from pravastatin to cerivastatin. The purpose of this study was to determine whether a more potent statin (cerivastatin) would further affect CRP, whether a relation ship between CRP and BChE existed, and if there were any relationships between CRP or BChE and lipids. In view of the withdrawal of cerivastatin from the market, studies considering the effects of conversion of patients from one statin to another are warranted. RESEARCH DESIGN AND METHODS: Thirty-seven patients actively taking pravastatin (10 mg-40 mg) were switched to cerivastatin (0.2 mg-0.8 mg) at the initial visit in the Lipid Clinic at David Grant Medical Center, Travis Air Force Base. Samples were collected before the conversion (pravastatin phase) and at 6 weeks and 12 weeks post-conversion. Patients were excluded from the study if they were taking gemfibrozil concomitantly. Patients were counseled on the adverse effects of cerivastatin, including rhabdomyolsis. RESULTS: Median CRP levels at the pravastatin phase, 6 weeks of cerivastatin, and 12 weeks of cerivastatin, were 0.380 mg/dL, 0.403 mg/dL, and 0.364 mg/dL (p = 0.772), respectively. Median BChE activity at the pravastatin phase, 6 weeks of cerivastatin, and 12 weeks of cerivastatin were 0.338 micromol/mL/min, 0.332 micromol/mL/min, 0.33 micromol/mL/min (p = 0.746), respectively. A negative correlation was observed between CRP and BChE at baseline only (r = -0.353, p = 0.032). There was a significant decline in mean TC (p < 0.001) and median LDL (p < 0.001) and a significant increase in mean HDL (p = 0.017) over the three time points. Numerically TG declined, but it was not statistically significant (p = 0.649). No correlations were observed between CRP or BChE and any of the lipids. Gender, aspirin use, and the presence of CHD or diabetes did not affect CRP levels or BChE activity. CONCLUSION: Median CRP remained stable with pravastatin and cerivastatin use, although TC and LDL decreased. The further decline observed with LDL, but not CRP suggests differing effects of statins on LDL and CRP. Limitations include no serum levels prior to statin use and small sample size; thus, future studies are needed to address the relationship between cholesterol and CRP and the mechanism of action of statins on CRP.

Adult↗
PubMed2004

Increased mortality associated with HTLV-II infection in blood donors: a prospective cohort study.

BACKGROUND: HTLV-I is associated with adult T-cell leukemia, and both HTLV-I and -II are associated with HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Several published reports suggest that HTLV-I may lead to decreased survival, but HTLV-II has not previously been associated with mortality. RESULTS: We examined deaths among 138 HTLV-I, 358 HTLV-II, and 759 uninfected controls enrolled in a prospective cohort study of U.S. blood donors followed biannually since 1992. Proportional hazards models yielded hazard ratios (HRs) for the association between mortality and HTLV infection, controlling for sex, race/ethnicity, age, income, educational level, blood center, smoking, injection drug use history, alcohol intake, hepatitis C status and autologous donation. After a median follow-up of 8.6 years, there were 45 confirmed subject deaths. HTLV-I infection did not convey a statistically significant excess risk of mortality (unadjusted HR 1.9, 95%CI 0.8-4.4; adjusted HR 1.9, 95%CI 0.8-4.6). HTLV-II was associated with death in both the unadjusted model (HR 2.8, 95%CI 1.5-5.5) and in the adjusted model (HR 2.3, 95%CI 1.1-4.9). No single cause of death appeared responsible for the HTLV-II effect. CONCLUSIONS: After adjusting for known and potential confounders, HTLV-II infection is associated with increased mortality among healthy blood donors. If replicated in other cohorts, this finding has implications for both HTLV pathogenesis and counseling of infected persons.

Blood Donors↗
PubMed2004

Evaluation of a real-time fluorescent PCR assay for rapid detection of Group B Streptococci in neonatal blood.

Streptococcus agalactiae (Group B Streptococcus: GBS) is the major causative agent of neonatal sepsis. Neonates at risk for GBS infections are empirically administered broad-spectrum antibiotics for at least 48 h pending blood culture results. A rapid assay to expedite detection of GBS would facilitate initiation of specific antibiotic therapy. Conversely, expeditious proof of absence of infection will avoid unnecessary antibiotic use. Using the LightCycler, we evaluated a hybridization probe polymerase chain reaction (PCR) assay to detect GBS-specific cfb gene target DNA sequence in blood specimens. Both sensitivity and specificity of the real-time PCR assay was 100%. The assay demonstrated 100% specificity when tested against 26 non-GBS bacteria. This method is capable of detecting as few as approximately 100 copies or 10 pg of GBS genomic DNA. This real-time PCR method is rapid, sensitive, and specific for the detection of GBS in neonatal blood samples and holds great promise in its utility in the diagnostic laboratory.

Base Sequence↗
PubMed2004

Respiratory and urinary tract infections, arthritis, and asthma associated with HTLV-I and HTLV-II infection.

Human T-lymphotropic virus types I and II (HTLV-I and -II) cause myelopathy; HTLV-I, but not HTLV-II, causes adult T-cell leukemia. Whether HTLV-II is associated with other diseases is unknown. Using survival analysis, we studied medical history data from a prospective cohort of HTLV-I- and HTLV-II-infected and -uninfected blood donors, all HIV seronegative. A total of 152 HTLV-I, 387 HTLV-II, and 799 uninfected donors were enrolled and followed for a median of 4.4, 4.3, and 4.4 years, respectively. HTLV-II participants had significantly increased incidences of acute bronchitis (incidence ratio [IR] = 1.68), bladder or kidney infection (IR = 1.55), arthritis (IR = 2.66), and asthma (IR = 3.28), and a borderline increase in pneumonia (IR = 1.82, 95% confidence interval [CI] 0.98 to 3.38). HTLV-I participants had significantly increased incidences of bladder or kidney infection (IR = 1.82), and arthritis (IR = 2.84). We conclude that HTLV-II infection may inhibit immunologic responses to respiratory infections and that both HTLV-I and -II may induce inflammatory or autoimmune reactions.

Adult↗
PubMed2003

Pulmonary function testing in HTLV-I and HTLV-II infected humans: a cohort study.

BACKGROUND: HTLV-I infection has been linked to lung pathology and HTLV-II has been associated with an increased incidence of pneumonia and acute bronchitis. However it is unknown whether HTLV-I or -II infection alters pulmonary function. METHODS: We performed pulmonary function testing on HTLV-I, HTLV-II and HTLV seronegative subjects from the HTLV outcomes study (HOST), including vital capacity (VC), forced expiratory volume in one second (FEV1), and diffusing lung capacity for carbon monoxide (DLCO) corrected for hemoglobin and lung volume. Multivariable analysis adjusted for differences in age, gender, race/ethnicity, height and smoking history. RESULTS: Mean (standard deviation) pulmonary function values among the 257 subjects were as follows: FVC = 3.74 (0.89) L, FEV1 = 2.93 (0.67) L, DLCOcorr = 23.82 (5.89) ml/min/mmHg, alveolar ventilation (VA) = 5.25 (1.20) L and DLCOcorr/VA = 4.54 (0.87) ml/min/mmHg/L. There were no differences in FVC, FEV1 and DLCOcorr/VA by HTLV status. For DLCOcorr, HTLV-I and HTLV-II subjects had slightly lower values than seronegatives, but neither difference was statistically significant after adjustment for confounding. CONCLUSIONS: There was no difference in measured pulmonary function and diffusing capacity in generally healthy HTLV-I and HTLV-II subjects compared to seronegatives. These results suggest that previously described HTLV-associated abnormalities in bronchoalveolar cells and fluid may not affect pulmonary function.

Journal Article↗
PubMed2003

TNF-alpha detection using a flow cytometric assay to determine cellular responses to anthrax vaccine.

This study describes a four-color flow cytometric assay that detects CD4+ T cell responses to the anthrax vaccine. Whole blood from seven volunteers who previously obtained the anthrax vaccine was inoculated in vitro with varying concentrations of the anthrax antigen. TNF-alpha and IFN-gamma production from memory CD4+ T cells were measured and compared to a control group who never received the anthrax vaccine. The optimal antigen concentration for TNF-alpha was determined to be around 7.5 microg/ml and IFN-gamma production was not detected. This assay will be used in future larger prospective studies to further evaluate the cellular immune responses induced by the anthrax vaccine.

Anthrax Vaccines↗
PubMed2003

Therapeutic apheresis services provided by a community blood bank.

Therapeutic apheresis services can be provided from a community-based blood center. The Oklahoma Blood Institute uses a mobile approach, primarily servicing 10 major hospitals in the Oklahoma City metropolitan area within a 15 to 20 mile radius. Apheresis staff and equipment are available 24 hours per day, 7 days per week in the event of patient referral requiring an emergency therapeutic apheresis procedure. This model requires close communication between the therapeutic apheresis medical director and the referring clinician. Telephone and facsimile transmissions of information are used to facilitate the transfer of information to all persons/facilities involved in providing treatment. This approach has proven effective in providing the required procedures for a referral population base of several million people spread over a fairly large geographic area.

Ambulances↗
PubMed2003

The effects of jet fuel on immune cells of fuel system maintenance workers.

Jet fuel is a common occupational exposure among commercial and military maintenance workers. JP-8 jet fuel, a military formulation, has shown immunotoxic effects in mice, but little data exist for humans. The aim of this cross-sectional study was to determine whether immune cell counts in the peripheral blood were altered among tank entry workers at three Air Force bases. After adjusting for covariates, fuel system maintenance personnel (n = 45) were found to have significantly higher counts of white blood cells (P = 0.01), neutrophils (P = 0.05), and monocytes (P = 0.02) when compared with a low-exposure group (n = 78), but no differences were noted in the numbers of total lymphocytes, T-cells, T-helper cells, T-suppressor cells, natural killer cells, and B-cells. Investigations are needed to evaluate the functional ability of these cells to produce lymphokines and cytokines and modulate the immune system.

Adolescent↗
PubMed2003

Use of yellow plastic food wrap to retard composite resin polymerization.

BACKGROUND: Dental chair lights can rapidly polymerize light-reactive composites beyond the point of workability, preventing adequate time for the shaping and sculpting of large direct composite restorations. PURPOSE: The purpose of this study was to determine whether yellow plastic food wrap placed over a dental chair light would perceptibly retard the polymerization rate of a light-cured composite (Esthet-X, shade A1, Dentsply/Caulk, Milford, DE, USA). MATERIALS AND METHODS: Zero, one, and two thicknesses of yellow plastic food wrap (Reynolds Metals Company, Richmond, VA, USA) were, in turn, used in the following scenarios: (1) placed in a spectrophotometer and compared for percentage transmission of 470 nm light; (2) placed over a curing unit light wand and compared for milliwatts of output on a radiometer; (3) placed over a dental chair light positioned 64 cm from 0.22 mm thick composite specimens, with Fourier Transform Infrared Spectrometry readings made every 40 seconds to measure degree of composite polymerization; (4) placed over a dental chair light positioned 64 cm from a direct veneer preparation (clinical simulation), which was then restored by four experienced clinicians who reported working times. RESULTS: Results for the scenarios were as follows: (1) zero sheets 100%, one sheet 34%, two sheets 6%; (2) zero sheets 580 mW, one sheet 190 mW, two sheets 20 mW; (3) percent conversion at 80 seconds--zero sheets 8%, one sheet 0.65%, two sheets 0.76%; percent conversion at 120 seconds--zero sheets 19.11%, one sheet 12.22%, two sheets 0.42%; (4) mean working times--zero sheets 34 seconds, one sheet 72 seconds, two sheets 155 seconds. CONCLUSIONS: Yellow plastic food wrap placed over a dental chair light markedly extended the working time of a light-cured composite in each of four assessments performed. Two sheets of plastic wrap were more than twice as effective as one sheet. CLINICAL SIGNIFICANCE: The suggested filtering technique with yellow plastic wrap placed over a dental chair light is a highly effective, expedient, and inexpensive method for increasing the working time of light-cured composites.

Color↗
PubMed2003

Correlation of organism burden and alveolar macrophage counts during infection with Pneumocystis carinii and recovery.

Changes in the number of alveolar macrophages were correlated with organism burden during Pneumocystis carinii infection. The lungs of healthy, dexamethasone-treated, and dexamethasone-treated and P. carinii-infected rats were lavaged with phosphate-buffered saline. Counting of alveolar macrophages in the lavage fluids revealed that P. carinii infection caused a 58% decrease in the number of alveolar macrophages and that higher P. carinii organism burdens caused a more rapid decrease in alveolar macrophage number. As a control, healthy rats were challenged with the same number of organisms as that normally used to generate P. carinii infections in dexamethasone-treated rats. Thirteen days after challenge, these rats had a profound (54%) increase in alveolar macrophage number in response to the challenge, while the number of alveolar macrophages in immunosuppressed and P. carinii-infected rats had decreased significantly by this time point. These experiments created the first animal model to mimic human pneumocystis pneumonia in alveolar macrophage number alterations. Reduction of P. carinii organism numbers by treatment of rats with trimethoprim and sulfamethoxazole brought a slow rebound in alveolar macrophage number, while recovery from P. carinii infection by cessation of immunosuppression brought a rapid rebound in alveolar macrophage number. These results suggest that both the immune state of the host and P. carinii burden affect alveolar macrophage number.

Animals↗
PubMed2002

Innovations in blood donor screening and blood collection.

Blood donor screening and blood collection are two of the donor-focused activities inherent in the process of maintaining an adequate blood supply. Donor screening represents procedures to provide safety for both donors as well as recipients. Donor medical history questions are so cumbersome that self-administered manual, computer-assisted, or on-line donor questions are under consideration in order to reduce time involved in the screening process. Blood collection procedures remain primarily based on whole blood donations, but apheresis donations are increasing steadily. The yield of multiple transfusible units per donation, as well as quality and reproducibility per product, support the use of apheresis procedures or other automated whole blood techniques to help offset blood shortages.

Blood Component Removal↗