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Biomedical subjects

A Black

Publications and source records attributed to A Black.

At least 37 records · Page 2Linked to original sources
PubMed2001

A humanized anti-human CD154 monoclonal antibody blocks CD154-CD40 mediated human B cell activation.

Humanized anti-CD154 antibody, IDEC-131, had a slightly, but reproducibly, better binding affinity for CD154 (Kd = 5.6 nM), compared to the parent antibody 24-31 (Kd = 8.5 nM). Otherwise it was indistinguishable from the murine parent antibody in its ability to bind to CD154, block CD154 binding to CD40 and inhibit T cell-dependent B cell differentiation. The latter activity was independent of FcR binding as the Fab'1 fragment of IDEC-131 had an equivalent biological activity to that of the whole antibody. IDEC-131 blocked soluble CD154 from inducing proliferation of purified B cells, and blocked T cell dependent anti-tetanus toxoid specific antibody production by human B cells in vitro. IDEC-131, gamma1, kappa, had strong Fc gammaRI, Fc gammaRII and C1q binding, but was unable to induce complement dependent (CDC) or antibody dependent cell-cytotoxicity (ADCC) of activated peripheral blood T cells, which express relatively low levels of CD154. IDEC-131 antibody inhibited both primary and secondary antibody responses to ovalbumin in cynomolgus monkeys at a dose of 5 mg/kg. In non-immunized animals, treatment with IDEC-131 at 50 mg/kg weekly for 13 weeks induced no change in any of the measured lymphocyte subsets, including B cells, CD4+ and CD8+ T cells. Similarly, a safety study in chimpanzees showed no discernible safety related issues at 20 mg/kg, including B and T cell subsets. These results show that the humanized anti-CD154 antibody, IDEC-131, has retained the affinity and functional activity of its murine parent antibody, is unlikely to deplete CD154 positive lymphocytes in humans, and is safe and effective in blocking antibody production in monkeys. Based on its safety and efficacy profile, IDEC-131 is being developed for therapy of systemic lupus erythematosus.

Amino Acid Sequence↗
PubMed2001

A nonhuman primate model of age-related bone loss: a longitudinal study in male and premenopausal female rhesus monkeys.

Aging is associated with gradual bone loss in men and premenopausal women, with an accelerated rate of loss after menopause in women. Although many studies have investigated bone loss due to surgically induced estrogen depletion, little is known regarding normal age-related changes in bone mass in animal models. We used dual-energy X-ray absorptiometry (DXA) to measure bone mineral density (BMD), bone mineral content (BMC), and projected area (PA) at four skeletal sites over 4 years in 20 premenopausal female (8-23 years) and 29 male (8-27 years) rhesus monkeys (Macaca mulatta). Forearm BMD declined with age in both male and female monkeys. Lean mass was positively associated with BMD at all sites in males and with the distal radius in females. Serum osteocalcin declined and urinary cross-links increased with age in males but not females. Serum 25-hydroxyvitamin D concentrations decreased with age in females, and a similar trend was observed in males. In conclusion, an age-related decline in forearm BMD was observed in male and female rhesus monkeys. Total body BMC declined over time in older females, with a similar trend in males. Changes in markers of bone turnover with age were also observed in male monkeys. The results of this longitudinal study suggest that the rhesus monkey is a potential model for age-related changes in the human skeleton.

Absorptiometry, Photon↗
PubMed2001

Accuracy and precision of dual-energy X-ray absorptiometry for body composition measurements in rhesus monkeys.

Accuracy of body composition measurements by dual-energy X-ray absorptiometry (DXA) was compared with direct chemical analysis in 10 adult rhesus monkeys. DXA was highly correlated (r-values > 0.95) with direct analyses of body fat mass (FM), lean mass (LM) and lumbar spine bone mineral content (BMC). DXA measurements of total body BMC were not as strongly correlated (r-value = 0.58) with total carcass ash content. DXA measurements of body FM, LM and lumbar spine BMC were not different from data obtained by direct analyses (P-values > 0.30). In contrast, DXA determinations of total BMC (TBMC) averaged 15%, less than total carcass ash measurements (P = 0.002). In conclusion, this study confirms the accurate measurement of fat and lean tissue mass by DXA in rhesus monkeys. DXA also accurately measured lumbar spine BMC but underestimated total body BMC as compared with carcass ash determinations.

Absorptiometry, Photon↗
PubMed2001

AUStralian study of titration to effect profile of safety (AUS-STEPS): high-dose gabapentin (neurontin) in partial seizures.

PURPOSE: To evaluate the safety, tolerability, efficacy, and impact on quality of life of gabapentin (Neurontin; GBP) as adjunctive therapy in patients with refractory partial seizures. METHODS: AUS-STEPS was an open-label, multicenter, prospective study in patients experiencing partial seizures who were inadequately controlled with one to three concurrent antiepileptic drugs (AEDs). GBP treatment was titrated to a maximum of 4,800 mg/day, over a treatment period of 24 weeks, to achieve an efficacious and tolerable dosage. Efficacy was assessed by seizure-frequency data. Quality of life was evaluated by using the QOLIE-10 questionnaire, and safety was assessed by adverse-event reports and clinical laboratory findings. RESULTS: A total of 176 patients received treatment with GBP, with 174 evaluable for intention-to-treat (ITT) efficacy analysis. A reduction of >50% in overall seizure frequency was observed in 93 patients (53%). There was a small (4.6%) overall improvement in QOLIE-10 score. The most frequent adverse events were dizziness (31%), fatigue (29%), somnolence (27%), headache (21%), and ataxia (20%), with no major increase seen in adverse events necessitating discontinuation as the dose of GBP was titrated upward. CONCLUSIONS: This study indicates that patients with partial epilepsy may be effectively treated with GBP at dosages of < or =4,800 mg/day, without altering the safety profile of the drug.

Acetates↗
PubMed2001

Potential economic impact of using a proprietary willow bark extract in outpatient treatment of low back pain: an open non-randomized study.

An open, non-randomised, study (postmarketing surveillance) was carried out on three groups of patients aged 18 to 80 presenting over an 18 month period with acute exacerbations of low back pain. The objective was to assess the possible economic impact of including a regular dose of proprietary willow bark extract (Assalix) in the treatment provided. A first group of 115 patients, presenting to 3 general practitioners in the first 3 months, was prescribed a daily dose of extract containing 120 mg of salicin (group W120). They also had access, if necessary, to the range of conventional treatments allowed for in the general practitioners' budgets. A second group of 112 patients presenting to the same general practitioners over the next 15 months, was prescribed extract equivalent to 240 mg salicin per day (group W240). A third "control" or "comparator" group of 224 patients, presenting to 3 orthopedists (specialists in physical medicine) over the whole 18 month period, received only the conventional therapeutic options allowed in the orthopedists' budgets (Group C). In the group C patients, the exacerbations had been shorter but the pain had been more intense as judged by Arhus Index and Total Pain Index. After 4 weeks of treatment, about 40% of group W240 patients were free of pain whether or not they had to resort to supplementary treatments. In group W120 as a whole, about 19% of patients were pain-free at 4 weeks, but only 8% of those who did not resort to supplementary treatment. In group C, 18% of patients were painfree. These findings were reflected reasonably well in the changes in the Arhus Index and Total Pain Index, and the findings in group W240 were consistent with those in a previous randomised controlled trial. Multivariable modelling to examine for possible confounding effects tended to identify membership of group W240 as an independent explanator of better pain relief than membership of group C. Though the measures of effect tended to be similar in group W120 as a whole and group C, the avoidance of more expensive conventional treatments in group W120 meant that the average cost per patient of treatment was reduced by about 35-50% (health service and private costings respectively). The better pain relief in group W240 was accompanied by an even smaller reliance on supplementary conventional treatments than in group W120 but the extra savings on these were outweighed by the extra cost of the additional Assalix so that the average cost per patient was reduced by 14-40% of the costs in group C. The possibility is discussed that, if orthopedists had relied more on regular full dosing with NSAIDs, they might have increased the effectiveness and reduced the cost of their treatment, though with the possibility of more side effects. Substituting established NSAIDs with COX-2 inhibitors might reduce the side effects, but at greater cost than with the Assalix.

Adolescent↗
PubMed2001

Calorie restriction and skeletal mass in rhesus monkeys (Macaca mulatta): evidence for an effect mediated through changes in body size.

Little is known regarding the effects of prolonged calorie restriction (CR) on skeletal health. We investigated long-term (11 years) and short-term (12 months) effects of moderate CR on bone mass and biochemical indices of bone metabolism in male rhesus monkeys across a range of ages. A lower bone mass in long-term CR monkeys was accounted for by adjusting for age and body weight differences. A further analysis indicated that lean mass, but not fat mass, was a strong predictor of bone mass in both CR and control monkeys. No effect of short-term CR on bone mass was observed in older monkeys (mean age, 19 years), although young monkeys (4 years) subjected to short-term CR exhibited slower gains in total body bone density and content than age-matched controls. Neither biochemical markers of bone turnover nor hormonal regulators of bone metabolism were affected by long-term CR. Although osteocalcin concentrations were significantly lower in young restricted males after 1 month on 30% CR in the short-term study, they were no longer different from control values by 6 months on 30% CR.

Animals↗
PubMed2001

Energy restriction does not alter bone mineral metabolism or reproductive cycling and hormones in female rhesus monkeys.

Energy restriction (ER) extends the life span and slows aging and age-related diseases in short-lived mammalian species. Although a wide variety of physiological systems have been studied using this paradigm, little is known regarding the effects of ER on skeletal health and reproductive aging. Studies in rhesus monkeys have reported that ER delays sexual and skeletal maturation in young male monkeys and reduces bone mass in adult males. No studies have examined the chronic effects on bone health and reproductive aging in female rhesus monkeys. The present cross-sectional study examined the effects of chronic (6 y) ER on skeletal and reproductive indices in 40 premenopausal and perimenopausal (7-27 y old) female rhesus macaques (Macaca mulatta). Although ER monkeys weighed less and had lower fat mass, ER did not alter bone mineral density, bone mineral content, osteocalcin, 25-hydroxyvitamin D, 1,25-hydroxyvitamin D or parathyroid hormone concentrations, menstrual cycling or reproductive hormone concentrations. Body weight and lean mass were significantly related to bone mineral density and bone mineral content at all skeletal sites (total body, lumbar spine, mid and distal radius; P: < or = 0.04). The number of total menstrual cycles over 2 y, as well as the percentage of normal-length cycles (24-31 d), was lower in older than in younger monkeys (P: < or = 0.05). Older monkeys also had lower estradiol (P: = 0.02) and higher follicle-stimulating hormone (P: = 0.02) concentrations than did younger monkeys. We conclude that ER does not negatively affect these indices of skeletal or reproductive health and does not alter age-associated changes in the same variables.

Aging↗
PubMed2001

Treatment of low back pain with a herbal or synthetic anti-rheumatic: a randomized controlled study. Willow bark extract for low back pain.

OBJECTIVES: To compare the effects of a proprietary extract of willow bark (Assalix) and a selective inhibitor (rofecoxib) of the enzyme cyclo-oxygenase-2 (COX-2). METHODS: An open, randomized, post-marketing study was carried out in an out-patients clinic on two groups of patients aged 18 to 80 yr presenting over a 6-month period with acute exacerbations of low back pain. Using computer-generated random list, 114 patients were allocated to receive a daily dose of herbal extract containing 240 mg of salicin [PAID (phyto-anti-inflammatory drug) group] and 114 were allocated to receive 12.5 mg of the synthetic COX-2 inhibitor rofecoxib [NSAID (non-steroidal anti-inflammatory drug) group]. The doses were chosen according to existing recommendations. All patients were free to use whatever additional conventional treatments were thought necessary. The outcome measures were a modified Arhus index, its pain component and the Total Pain Index. RESULTS: Groups were well matched. After 4 weeks of treatment, the Arhus index had improved by about 20%, its pain component by about 30% and the Total Pain Index by about 35%. The number of pain-free patients (visual analogue scale score <2) was about 20 in each group. About 60% of the patients in each group responded well to the treatment (as judged by an improvement of >/=30% in the Total Pain Index relative to its baseline). The improvement was also reflected reasonably well in the physicians' and patients' judgements of the effectiveness of treatment, which were largely concordant. Few patients of either group resorted to the additional conventional treatment options. The incidence of adverse events was similar in the two groups. Treatment with rofecoxib was about 40% more expensive than that with Assalix. CONCLUSION: There was no significant difference in effectiveness between the two treatments at the doses chosen. Treatment with Assalix was less expensive.

Adolescent↗
PubMed2001

Caloric restriction in primates.

Caloric restriction (CR) remains the only nongenetic intervention that reproducibly extends mean and maximal life span in short-lived mammalian species. This nutritional intervention also delays the onset, or slows the progression, of many age-related disease processes. The diverse effects of CR have been demonstrated many hundreds of times in laboratory rodents and other short-lived species, such as rotifers, water fleas, fish, spiders, and hamsters. Until recently, the effects of CR in longer-lived species, more closely related to humans, remained unknown. Long-term studies of aging in nonhuman primates undergoing CR have been underway at the National Institute on Aging (NIA) and the University of Wisconsin-Madison (UW) for over a decade. A number of reports from the NIA and UW colonies have shown that monkeys on CR exhibit nearly identical physiological responses as reported in laboratory rodents. Studies of various markers related to age-related diseases suggest that CR will prevent or delay the onset of cardiovascular disease, diabetes, and perhaps cancer, and preliminary data indicate that mortality due to these and other age-associated diseases may also be reduced in monkeys on CR, compared to controls. Conclusive evidence showing that CR extends life span in primates is not presently available; however, the emerging data from the ongoing primate studies strengthens the possibility that the diverse beneficial effects of CR on aging in rodents will also apply to nonhuman primates and perhaps ultimately to humans.

Aging↗
PubMed2001

Communications planning.

Whether you are communicating a totally new benefit program or announcing a change in an existing one, effective planning will make the difference between success and failure of your communications campaign. Effective benefits communication is more than just distributing a summary plan description or conducting an employee meeting. It's more than spending a lot of money on elaborate brochures or expensive videotapes, or posting information on the intranet. More and more, benefits communicators are expected to communicate in a way that influences employees to make changes in their personal lives, a tall order that requires careful planning and coordination.

Budgets↗
PubMed2000

Combination therapy with interferon-alpha plus N-acetyl cysteine for chronic hepatitis C: a placebo controlled double-blind multicentre study.

A small pilot study in patients with chronic hepatitis C (HCV) infection suggested that antiviral treatment with interferon (IFN) plus N-acetyl cysteine (NAC) was more effective than treatment with interferon alone [Beloqui et al. (1993) Journal of Interferon Research 13:279-282]. An attempt was made to confirm this by performing a placebo-controlled double-blind study at 8 medical centres in Spain and Italy. One-hundred forty-seven patients with chronic HCV infection were investigated, 73 received 3MU IFN-alpha thrice weekly plus NAC 1800 mg daily and 74 received IFN alone. Treatment was continued for 6 months and patients were followed up for a further 6 months. Amongst patients receiving IFN plus NAC, sustained virological responses were observed in 5.5%, transient responses in 26% and non-response in 68.5%. The figures for patients receiving IFN only were 4.1%, 24.3% and 71.6% respectively. Sustained virological response was significantly associated with non-type 1 genotypes (P = 0.045) and with low pre-treatment viraemia levels (P = 0.034). Biochemical response (serum ALT concentrations) correlated with virological outcome in 97% (n = 139) of cases. Patients who experienced a sustained virological response also showed reduction in the Knodell histological activity index. It is concluded that patients with chronic HCV infection are very unlikely to benefit from the addition of N-acetyl cysteine to conventional therapy with interferon-alpha.

Acetylcysteine↗
PubMed2000

Serum S-100 protein release and neuropsychologic outcome during coronary revascularization on the beating heart: a prospective randomized study.

OBJECTIVES: Our purpose was to establish whether coronary revascularization on the beating heart without cardiopulmonary bypass is less harmful to the brain than conventional surgery with cardiopulmonary bypass as indicated by measures of cognitive function or by changes in serum concentrations of S-100 protein, a recognized biochemical marker of cerebral injury. METHODS: We conducted a prospective randomized trial in which the assessors of the outcome measures were blind to the treatment received. Sixty patients without known neurologic abnormality, undergoing coronary revascularization, were prospectively randomized to 1 of 2 groups: (1) cardiopulmonary bypass (32 degrees C-34 degrees C) and cardioplegic arrest (on pump) with intermittent antegrade warm blood cardioplegia or (2) surgery on the beating heart (off pump). Neuropsychologic performance was assessed before and 12 weeks after the operation. Serum S-100 protein concentration was measured at intervals up to 24 hours after the operation. RESULTS: The groups had similar preoperative characteristics. There were no deaths or major neurologic complications in either group, nor was there any difference between groups in the chosen index of neurologic deterioration. Serum S-100 protein concentrations were higher in the on-pump group at 30 minutes, but any such difference between groups had disappeared 4 hours later. The extent of the changes in S-100 protein was unrelated to the index of neuropsychologic deterioration. CONCLUSIONS: The changes in S-100 protein concentration suggest that the brain and/or blood-brain barrier may be more adversely affected during coronary artery surgery with cardiopulmonary bypass than during surgery on the beating heart, but that this may not be reflected in detectable neuropsychologic deterioration at 12 weeks.

Aged↗
PubMed2000

Effects of reduced energy intake on the biology of aging: the primate model.

Dietary energy restriction is the only proven method for extending lifespan and slowing aging in mammals, while maintaining health and vitality. Although the first experiments in this area were conducted over 60 y ago in rodents, possible applicability to primates has only been examined in controlled studies since 1987. Our project at the National Institute on Aging began with 3-0 male rhesus and 30 male squirrel monkeys of various ages over their respective life spans. Subsequently, it has been expanded to include female rhesus monkeys, and several other laboratories have initiated related studies. Experimental animals are generally fed 30% less than controls, and diets are supplemented with micronutrients to achieve undernutrition without malnutrition. These calorically restricted (CR) monkeys are lighter, with less fat and lean mass than controls. Bone mass is also slightly reduced, but in approximate proportion to the smaller body size. CR animals mature more slowly and achieve shorter stature than controls as well. Metabolically, CR monkeys have slightly lower body temperature and initial energy expenditure following onset of restriction, and better glucose tolerance and insulin sensitivity. The latter suggest a reduced predisposition towards diabetes as the animals age. Other potential anti-disease effects include biomarkers suggestive of lessened risk of cardiovascular disease and possibly cancer. Candidate biomarkers of aging, including the age-related decrease in plasma dehydroepiandrosterone sulfate (DHEAS), suggest that the CR animals may be aging more slowly than controls in some respects, although sufficient survival data will require more time to accumulate. In summary, nearly all CR effects detected in rodents, which have thus far been examined in primates, exhibit similar phenomenology. Potential applicability of these beneficial effects to humans is discussed.

Aging↗
PubMed2000

Vascular complications and clinical outcome after coronary angioplasty with platelet IIb/IIIa receptor blockade. Comparison of transradial vs transfemoral arterial access.

AIMS: Vascular complications associated with femoral artery access for interventional cardiological procedures may increase morbidity especially in patients receiving anticoagulants, aspirin, ticlopidine and platelet glycoprotein IIb/IIIa receptor inhibitors. The use of radial arterial access has the potential to reduce the incidence of access site bleeding complications. The purpose of this study was to compare outcomes after the radial and femoral approaches in patients treated with the platelet IIb/IIIa inhibitor, abciximab. METHODS AND RESULTS: One hundred and fifty consecutive patients treated by abciximab underwent angioplasty by the radial or femoral approach in 83 and 67 cases, respectively. Outcome variables were major cardiac events and major access site bleeding at 1-month follow-up. Freedom from major cardiac events at 1-month follow-up occurred in 78 (93.9%) and 63 (94.0%) patients in the radial and femoral groups, respectively (P=0.99). There were no major access site bleeding complications in the radial group, as opposed to five (7.4%) in the femoral group, P=0.04. Postprocedure length of stay, days (3.7+/-6.0 radial vs 3.7+/-2.6 femoral, P=0.96) as well as total hospital length of stay (5.0+/-4.3 radial vs 4.9+/-3.0 femoral, P=0.72) were similar in both groups. CONCLUSION: Coronary angioplasty in patients treated by abciximab using the transradial approach is efficacious with fewer major access site complications than with the transfemoral approach.

Abciximab↗
PubMed1999

Activation and regulation of the IkappaB kinase in human B cells by CD40 signaling.

This study demonstrates that the engagement of CD40 results in the activation of the recently described IkappaB kinase (IKK) in a human B cell line. The kinase appears to reside within the cell in a cytosolic signalsome complex consisting of IKK, IkappaB, and an MKP-1-like molecule. While the binding of CD154 to CD40 induces the assembly of a CD40-TRAF receptor complex, IKK is not recruited to this complex. Nonetheless, a functional link between TRAF2 and IKK activity in B cells is demonstrated by the fact that overexpression of TRAF2 constitutively induces IKK activity, NF-kappaB luciferase and Fas expression. Synergy in the activation of IKK and NF-kappaB-dependent gene expression was observed by the simultaneous engagement of the B cell receptor and CD40, establishing an early means for cross-talk between these two B cell activation pathways. This study discusses the sequential biochemical events that transpire upon CD40 engagement by its ligand in human B cells.

Animals↗
PubMed1999

Risk management and pollution prevention: thinking outside the box.

The Medical University of South Carolina's risk management department received a 12-month grant from South Carolina's General Assembly "Hazardous Waste Management Research Fund" for the purpose of identifying pollution prevention opportunities within South Carolina healthcare facilities. One hundred and one healthcare facilities were invited to participate in this study. Facilities ranged in size from zero-licensed beds (clinics) to more than 300 beds. Seventy-six South Carolina facilities (75%) participated in this project.

Cost-Benefit Analysis↗