Search PubMed⌕ Search

Biomedical subjects

B Bradley

Publications and source records attributed to B Bradley.

At least 37 records · Page 2Linked to original sources

Endothelial cell precursors are normal components of human umbilical cord blood.

Endothelial cells are part of the normal bone marrow stroma. We have previously shown human umbilical cord blood (UCB) does not produce stroma in standard long-term cultures. Highly enriched (93-98%) UCB CD34+ cells were cultured for 6 weeks with interleukin-2 and conditioned medium from the 5637 carcinoma cell line (n = 4). The resulting 'fibroblast like' cells were shown to be endothelial by expression of von Willebrand factor (VWF), ICAM-1 (CD54), E-selectin (CD62E) and PECAM (CD31). Endothelial monolayers seeded with CD34+ UCB cells supported expansion of colony forming cells and CD34+ cells. We conclude that endothelial cell precursors circulate in UCB, and may be derived from the CD34+ cell fraction.

Antigens, CD34↗

Immunization services for adolescents within comprehensive school health programs.

Every school day, more than 95% of the nation's five- to 17-year-olds attend one of almost 110,000 elementary and secondary schools where they receive instruction in how to avoid major health-threatening behaviors. School is also the place where children and adolescents can be given preventive health care services, including administration of vaccines and monitoring of immunization levels. This article addresses how expanding school health services could improve immunization levels of school-aged youth.

Adolescent↗

Mental health in schools: expanded opportunities for school nurses.

Emerging trends are reshaping the work of school nurses and other school service personnel. With respect to direct service and consultation, school nurses increasingly are called upon to deal with psychosocial and mental health problems. Beyond that, school nurses must continue to actuate their roles as advocates, catalysts, brokers, and facilitators of the type of reforms that can effectively address barriers to student learning and promote healthy development. Continuing education is seen as key to enabling school nurses to build capacity for such roles and functions. The newly formed Center for Mental Health in Schools at the University of California, Los Angeles (UCLA) hopes to be of assistance in this respect. This presentation highlights the Center's orientation to mental health in schools and offers a draft outline for related continuing education.

Community Mental Health Services↗

Modified cytotoxic T lymphocyte precursor frequency assay by measuring released europium in a time resolved fluorometer.

The frequency of cytotoxic T lymphocyte precursors (CTLpf) can be quantified by using the principle of limiting dilution analysis (LDA). Chromium 51 (51Cr) and europium (Eu) release assays are based on the measurement of marker release after lysis of targets by the effector cells. Although, 51Cr release has been widely used to quantify cell lysis since its introduction, it has several disadvantages such as handling and disposal of radioisotopes as well as health risk to personnel involved performing the assay. This situation has led us to adopt a non-radioactive cytotoxicity assay. After 7 days culture the PHA-stimulated targets are labeled with europium DTPA chelate. Lysis of labeled targets by effectors releases the Eu-DTPA complex in culture medium--a highly fluorescent substance. The amount of fluorescence can be measured in a time resolved fluorometer. We describe here some modifications of the original protocol which include optimising IL-2 requirements, reduction of incubation times, addition of an extra spin before 37 degrees C incubation, readjustment of target cells per volume of labeling buffer and other crucial parameters increasing the specificity and sensitivity of CTLpf assay. We are in agreement with others that the Eu-release assay is specific and reproducible. It can be used for the CTLpf estimation as well as other T cell and non-T cell cytotoxicity assays.

Adult↗

Gemcitabine: symptomatic benefit in advanced non-small cell lung cancer.

Recent studies have indicated that chemotherapy not only provides some survival benefit, but also reduces tumor-related symptoms and improves the performance status of patients receiving chemotherapy. Data from single-agent gemcitabine studies demonstrate improvements in a range of tumor symptoms, including cough, hemoptysis, pain, dyspnea, and anorexia, as well as increases in performance status. Indeed, more patients benefit from gemcitabine chemotherapy than suggested by the objective response rate. Surveys also have shown that patients are much more likely to accept chemotherapy for what is perceived by health care professionals as potentially small benefits. Gemcitabine has a role in the palliative treatment of patients with advanced non-small cell lung cancer.

Antimetabolites, Antineoplastic↗

Cryopreserved human bone marrow stroma is fully functional in vitro.

Human-marrow long-term culture (LTC) enables maintenance of both stromal and haemopoietic elements of normal bone marrow (NBM) in vitro for 4-6 months. Stroma-based cultures are critical for quantitation of long-term culture initiating cells (LTC-IC), the most primitive human haemopoietic cells measurable in vitro. Supply of NBM can be sporadic, and up to 3-4 weeks in culture is required for stromal maturity. Stroma availability for experimental purposes can therefore be limited. Efforts to produce transformed human and transfected murine stromal cell lines comparable to NBM stroma have had some success. As an alternative, we investigated cryopreserved NBM and cryopreserved performed stroma. Function of cryopreserved and control fresh NBM stroma was similar when evaluated for up to 12 weeks in LTC. We have also demonstrated that stroma derived from cryopreserved NBM or performed cryopreserved NBM stroma can sustain third-party haemopoiesis as efficiently as fresh NBM stroma in LTC. Batched cryopreserved stroma is a convenient, rapidly available, source of functional stroma which avoids the logistic difficulties and lack of standardization associated with stroma from fresh NBM. This important advance will enhance the use of stroma-based LTC in studies of human haemopoiesis.

Bone Marrow↗

Guidelines for adolescent preventive services: a role for the school nurse.

Morbidity and mortality for today's adolescent are linked most often to complex behavioral and psychosocial risk factors than in the past. The American Medical Association has developed Guidelines for Adolescent Preventive Services (GAPS) to assist the primary health practitioner in deterring adolescents from participating in health-debilitating behaviors and to promote health-enhancing behaviors. Studies have affirmed usefulness of the GAPS protocol in the private practitioner's office and in the school-based clinic. This paper explores the possibility of using the traditional school nurse to deliver the GAPS in collaboration with school and community professionals. Issues explored include identifying students for he screening, administering the survey, triage of students, interdisciplinary and interagency collaboration, confidentiality, barriers, and time constraints.

Adolescent↗

Optimal processing of human umbilical cord blood for clinical banking.

Human umbilical cord blood (UCB) has been successfully used as an alternative source of allogeneic hematopoietic stem cells for pediatric transplantation. Clinical banking of UCB requires volume reduction and red cell depletion for cost-effective storage. We have compared processing UCB by Ficoll, Percoll, methylcellulose, gelatin, starch, and red cell lysis. As individual UCB collections vary widely in colony forming cell (CFC) and CD34+ cell content, each UCB (n = 26) was processed by three or more techniques in parallel with Ficoll as the "standard" method. Gelatin gave a consistently high recovery of CFC (92%) and CD34+ cells (86%). Between 0.10-2.50% of the leukocytes in gelatin-treated UCB were CD34+ with an intra-assay variation of 2.1%. Combining data from individual experiments, the correlation between CD34+ and CFC content was excellent (r = 0.77). Lysis rated second in terms of CD34+ and CFC recoveries but is not as practical because of the large volumes involved. Ficoll and Percoll came third but are more expensive and more involved techniques. Starch sedimentation proved to be slow, while methylcellulose processing lost over 60% of CFC and CD34+ cells. After gelatin processing, we calculated 70-mL donations of UCB would contain a mean +/- SD of 9 +/- 2 x 10(8) nucleated cells, 32 +/- 18 x 10(5) CD34+ cells, and 20 +/- 12 x 10(5) CFC with greater than 95% red cell depletion. Recent published computer studies suggest that as few as 2 x 10(5) CD34+ cells may be needed for sustained engraftment of allogeneic marrow in adult transplant recipients. We conclude that average 70-mL UCB donations contain sufficient marrow repopulating cells for adult recipients.

Antigens, CD34↗

Single oral dose fluconazole compared with conventional clotrimazole topical therapy of Candida vaginitis. Fluconazole Vaginitis Study Group.

OBJECTIVES: Candida vaginitis is currently treated with a wide range of intravaginal preparations usually prescribed over several days. Fluconazole with its marked activity against Candida species and favorable pharmacokinetics offered a safe, effective, and convenient alternative to topical therapy in a single-dose regimen. STUDY DESIGN: We conducted a multicenter, randomized, prospective, single-blinded study of 429 patients with acute Candida vaginitis, comparing the efficacy and safety of a single oral 150 mg dose of fluconazole with 7-day clotrimazole 100 mg vaginal treatment. Posttherapy evaluations and mycologic eradication rates were conducted. RESULTS: No statistically significant differences were seen between fluconazole and clotrimazole in the clinical, mycologic, or therapeutic responses. At the 14-day evaluation clinical cure or improvement was seen in 94% of fluconazole-treated patients and 97% of clotrimazole-treated patients. Mycologic and therapeutic cures were seen in 77% and 76% of the fluconazole and 72% of the clotrimazole groups, respectively. At the 35-day evaluation 75% of both groups remained clinically cured, and 56% of the fluconazole and 52% of the clotrimazole group were considered therapeutic cures. In both treatment groups patients with a history of recurrent vaginitis (33/84) compared with those without a history of recurrent vaginitis (177/266) were significantly less likely to respond clinically and mycologically (p < 0.001). Twenty-seven percent of the fluconazole-treated patients and 17% of the clotrimazole-treated patients reported mild side effects only. CONCLUSION: Fluconazole administered as a single 150 mg oral dose proved to be as safe and effective as 7 days of intravaginal clotrimazole therapy for Candida vaginitis. Therapy of vaginitis should be individualized, taking into consideration severity of disease, history of recurrent vaginitis, and patient preference.

Acute Disease↗

Patient information leaflets on over-the-counter (OTC) medicines: the manufacturer's perspective.

A survey was undertaken to assess the views of the manufacturers of over-the-counter (OTC) products about (i) the value of patient information leaflets (PILs), (ii) the recent European Community directive relating to PILs and (iii) the procedures which are in place for producing and testing PILs. Although approximately half (15/31) of the respondents (response rate 31/58) thought that PILs were more important for OTC than prescription only medicines, this view was not unanimous. A majority (18/28) thought that the new EC directive would provide too much information to patients although only a small number (2/27) thought that the regulations were unnecessary. Indication for the product was thought to be the most important information for the immediate outer packaging. Only about one-third (35%) of patients are thought to read PILs, in contrast to the majority who read the outer packaging. A wide variety of departments contribute to preparing PILs. The marketing department had a major input particularly with respect to layout and testing of leaflets. On the whole the design and production of PILs involves considerable effort but their testing appears less structured and thorough.

Drug Information Services↗

Analysis of cord blood CD34+ cells purified after cryopreservation.

Many practical issues regarding processing blood samples for cord blood banking remain. After cryopreservation, a reduction in clonogenicity has been reported, although it is unknown whether this is associated with lower potential for long-term engraftment. CD34+ cell purification of cryopreserved cord blood (CB) may be important for the clinical application of in vitro expansion. We compared purity, yield, clonogenicity, and growth in long-term stromal-based culture of fresh and cryopreserved CD34+ purified cells (n = 12) using the miniMACS separation system. Mean purity of CD34+ cells was 93% when processed before and 73% when processed after cryopreservation. Fresh CD34+ cells had higher clonogenic potential than cryopreserved cells (45 vs 20%, p < 0.05) in CFU-Mix assays, indicating that progenitor cell loss during cryopreservation is due in part to reduced cloning efficiency of viable CD34+ cells. In long-term culture (LTC) on irradiated normal human bone marrow stroma (n = 7), CFU-GM production in the two groups was the same over 12 weeks, suggesting identical long-term culture-initiating cell (LTC-IC) numbers. We conclude that apparent clonogenic cell loss during cryopreservation is associated with relative sparing of the more primitive LTC-ICs. CFU-Mix assays may therefore underestimate the transplant potential of cryopreserved CB. Purification of CD34+ cells following cryopreservation gives sufficient purity for detailed evaluation of CD34+ cells and for stem cell expansion.

Antigens, CD34↗

Readability of patient information leaflets on over-the-counter (OTC) medicines.

OBJECTIVE: To assess the readability of a sample of patient information leaflets included with over-the-counter (OTC) medicines. DESIGN: Fifty leaflets were obtained from a selection of proprietary products currently available on the U.K. market. The leaflets were scored using six established readability tests. RESULTS: The mean reading age was 15.4 using the Flesch test and 14.8 using the FOG and the SMOG tests. The individual reading age values for the leaflets ranged from 10 to 20 years. These mean values are well above the mean reading age of the general adult population. CONCLUSION: Manufacturers need to devise a means of producing leaflets which are easier to read. This is all the more urgent given the trend to down-regulate more potent medicines for non-prescription sale.

Drug Labeling↗

Negative recall bias and neuroticism: state vs trait effects.

Incidental recall of positive and negative trait adjectives was assessed in high and low N (neuroticism) Ss in whom depressed or neutral mood had been induced. Results indicated that the negative recall bias is an interactive function of trait vulnerability (as reflected by N scores) and current mood state. In the depressed mood condition, there was a trend for high N to be associated with relatively better recall of negative material, as expected. However, in neutral mood, high levels of N predicted relatively poorer recall of negative information. This unexpected finding was discussed in relation to previous research into mood-incongruent recall effects and sex differences.

Adult↗

Histocompatibility matching for bone marrow transplantation. Donor-recipient pairs in the 4AOHW cell panel.

While the results of unrelated bone marrow transplantation are continually improving, a number of important issues remain: what are the histocompatibility requirements, what genes are involved, what mismatches are acceptable, and what are the best methods for determining donor-recipient match? In this study of material provided through the 4AOHW and the US NMDP, the match between 53 donor-recipient pairs was determined using several different markers within the MHC. The data showed that many apparently well-matched pairs have many mismatches, including mismatches for non-HLA genes (i.e., non-class-I or non-class-II) within the MHC. New methods matching for blocks of DNA around HLA-B and around HLA-DR/DQ are available that are sensitive and identify additional mismatches that are not apparent using conventional typing methods. The 4AOHW cells provide a valuable resource for the comparison and assessment of new matching techniques.

Australia↗

Subjective craving for opiates: evaluation of a cue exposure protocol for use with detoxified opiate addicts.

Cue exposure has been advocated as an intervention for reducing relapse rates in detoxified addicts, by extinguishing classically conditioned drug effects/craving which may have developed. Several studies with alcoholics have found cue exposure to be associated with reductions in craving, but no controlled study has yet shown such an effect in opiate addicts. The present controlled group design evaluates a protocol which draws from experience in the treatment of anxiety and requires that each stimulus exposure should be continued until within-session habituation has occurred. It also explores whether there is any benefit of using a 'cognitive aversion' strategy during cue exposure, based on the social learning analysis that craving derives from expectancies of positive drug effects. A total of 21 detoxified in-patients were randomized to routine ward treatment plus two sessions of either cue exposure (Group E) or cue exposure and cognitive aversion (Group E/CA), or to routine treatment alone (Group C). A specially designed Craving Test was carried out before and after treatment, to assess change in cue-elicited reactions. The two treated groups showed significantly greater reductions in craving than Group C, but did not differ from each other. The cue exposure protocol has therefore been adopted for use in an ongoing clinical trial.

Adult↗

Cord blood banking for hematopoietic stem cell transplantation: an international cord blood transplant registry.

Human umbilical cord blood contains enough hematopoietic stem cells for transplantation instead of marrow cells to cure children and adults with leukemia and other potentially fatal marrow disorders. An international cord blood transplantation registry is currently collecting information about the results of these transplants. As a result of relative immune deficiency at birth, it is likely that partially matched unrelated transplants can be successful; for this purpose an international cord blood banking project is described.

Adult↗