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Biomedical subjects

J Bryant

Publications and source records attributed to J Bryant.

At least 91 records · Page 5Linked to original sources
PubMed1997

Leadership in British nursing: a historical dimension.

A historical overview of nurse leadership in the late 19th and late 20th centuries is presented, supported by relevant material from the literature. The 19th century material revealed the following main themes: emphasis on practical and domestic aspects of management; prominent input of religious ideals and social conscience and, autocratic and feminized style of leadership. The main themes in the contemporary literature examined were: role models in history, dysfunctional leadership styles, importance of knowledge, gender as an influencing factor on nurse leadership and threats to the autonomy of nurse leaders. It was concluded that formal nurse professionalization has progressed steadily during the past hundred years with associated evolution of nurse leaders to fit in with contemporary needs. It is hoped that future policies for nursing will encourage decision-making nearer the 'bed-side', more resource-driven care and value-based leadership.

Christianity↗
PubMed1997

Immunomodulatory function of interferon-gamma in patients with metastatic melanoma: results of a phase II-B trial in subjects with metastatic melanoma, ECOG study E 4987. Eastern Cooperative Oncology Group.

Interferon-gamma (IFN-gamma) has the most potent immunomodulatory activity of all the interferons. This phase II-B study was performed to define time- and dose-dependent immunomodulatory effects mediated by IFN-gamma in a subset of patients with melanoma treated in the dose-seeking therapeutic trial conducted by the Eastern Cooperative Oncology Group E4687 (13). The effects of IFN-gamma (Genentech, San Francisco, CA) were evaluated for phenotype and function of peripheral blood lymphocytes obtained twice prestudy, and on days 2, 9, and 29 of IFN-gamma therapy for 50 patients. Early significant increases in CD4/CD8 ratio (p = 0.001) were noted, largely due to a rise in CD4+ and fall in CD8+ T-cell populations sustained through day 29 at only the lowest dosage. Increased natural killer cell (NK) activity (p = 0.001 on day 9; p = 0.01 on day 29) was accompanied by durable increases in circulating activated NK cells (CD56+DR+% p = 0.001, day 9; p = 0.001, day 29). After initial depression of CD56+ and CD16+ cells on day 2, the total percent of CD56+ and CD16+ cells increased significantly by day 29. Increases in NK cell activity were maximal at doses > or =0.1 mg. Monocyte CD14+ expression of DQ+ rose early (p = 0.011 and 0.001 on days 2 and 9), accompanied by elevation in CD14+DR+ cells that was less significant. Immunomodulatory effects of IFN-gamma reported in this trial have major implications for interpretation of past and current clinical trials, and the design of future trials. This is the first trial in which IFN-gamma has been shown to have significant effects on the T-cell compartment of the immune system.

Adjuvants, Immunologic↗
PubMed1996

Five versus more than five years of tamoxifen therapy for breast cancer patients with negative lymph nodes and estrogen receptor-positive tumors.

BACKGROUND: In 1982, the National Surgical Adjuvant Breast and Bowel Project initiated a randomized, double-blinded, placebo-controlled trial (B-14) to determine the effectiveness of adjuvant tamoxifen therapy in patients with primary operable breast cancer who had estrogen receptor-positive tumors and no axillary lymph node involvement. The findings indicated that tamoxifen therapy provided substantial benefit to patients with early stage disease. However, questions arose about how long the observed benefit would persist, about the duration of therapy necessary to maintain maximum benefit, and about the nature and severity of adverse effects from prolonged treatment. PURPOSE: We evaluated the outcome of patients in the B-14 trial through 10 years of follow-up. In addition, the effects of 5 years versus more than 5 years of tamoxifen therapy were compared. METHODS: In the trial, patients were initially assigned to receive either tamoxifen at 20 mg/day (n = 1404) or placebo (n = 1414). Tamoxifen-treated patients who remained disease free after 5 years of therapy were then reassigned to receive either another 5 years of tamoxifen (n = 322) or 5 years of placebo (n = 321). After the study began, another group of patients who met the same protocol eligibility requirements as the randomly assigned patients were registered to receive tamoxifen (n = 1211). Registered patients who were disease free after 5 years of treatment were also randomly assigned to another 5 years of tamoxifen (n = 261) or to 5 years of placebo (n = 249). To compare 5 years with more than 5 years of tamoxifen therapy, data relating to all patients reassigned to an additional 5 years of the drug were combined. Patients who were not reassigned to either tamoxifen or placebo continued to be followed in the study. Survival, disease-free survival, and distant disease-free survival (relating to failure at distant sites) were estimated by use of the Kaplan-Meier method; differences between the treatment groups were assessed by use of the logrank test. The relative risks of failure (with 95% confidence intervals [CIs]) were determined by use of the Cox proportional hazards model. Reported P values are two-sided. RESULTS: Through 10 years of follow-up, a significant advantage in disease-free survival (69% versus 57%, P < .0001; relative risk = 0.66; 95% CI = 0.58-0.74), distant disease-free survival (76% versus 67%, P < .0001; relative risk = 0.70; 95% CI = 0.61-0.81), and survival (80% versus 76%, P = .02; relative risk = 0.84; 95% CI = 0.71-0.99) was found for patients in the group first assigned to receive tamoxifen. The survival benefit extended to those 49 years of age or younger and to those 50 years of age or older. Tamoxifen therapy was associated with a 37% reduction in the incidence of contralateral (opposite) breast cancer (P = .007). Through 4 years after the reassignment of tamoxifen-treated patients to either continued-therapy or placebo groups, advantages in disease-free survival (92% versus 86%, P = .003) and distant disease-free survival (96% versus 90%, P = .01) were found for those who discontinued tamoxifen treatment. Survival was 96% for those who discontinued tamoxifen compared with 94% for those who continued tamoxifen treatment (P = .08). A higher incidence of thromboembolic events was seen in tamoxifen-treated patients (through 5 years, 1.7% versus 0.4%). Except for endometrial cancer, the incidence of second cancers was not increased with tamoxifen therapy. CONCLUSIONS AND IMPLICATIONS: The benefit from 5 years of tamoxifen therapy persists through 10 years of follow-up. No additional advantage is obtained from continuing tamoxifen therapy for more than 5 years.

Antineoplastic Agents, Hormonal↗
PubMed1996

Tumor escape from immune recognition: lethal recurrent melanoma in a patient associated with downregulation of the peptide transporter protein TAP-1 and loss of expression of the immunodominant MART-1/Melan-A antigen.

In the last few years, mutiple protein target antigens for immunorecognition by T cells have been identified on human melanoma. How melanoma lesions escape from functional antigen-specific immune recognition remains poorly understood. We have identified the concomitant loss of the immunodominant T cell-defined MART-1/Melan-A antigen and downregulation of the TAP-1 gene in a recurrent metastatic melanoma that was resected in 1993. This phenotype was not observed for an earlier autologous melanoma lesion resected in 1987. The "antigen loss" could be restored in the variant tumor cell line by simultaneously providing both the MART-1/Melan-A gene (by retroviral transfer) and the TAP-1 gene (by a bioballistic approach) resulting in tumor cell sensitivity to MART-1/Melan-A-specific cytotoxic T lymphocytes. This suggests that tumor escape from immune surveillance may have occurred in vivo as a sequential result of (a) antigen loss, and (b) downregulation of the peptide-transporter protein TAP-1 expression by this patient's tumor over a 6-yr period from 1987 to 1993. These results suggest that the characterization of the T cell response to melanoma in individual patients and definition of the immunologically relevant genetic defects in tumors may be required to select the most effective therapeutic strategies for a given patient.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Northern Vietnamese households.

"Virtually all discussions of northern Vietnamese households have concentrated on cross-sectional measures of household size and structure. Such measures must be combined with longitudinal measures and measures of size as experienced by household members to give a full picture of northern Vietnamese households. On all these measures southern Vietnamese households appear significantly different from northern Vietnamese households."

Asia↗
PubMed1996

Marrow transplantation for Fanconi anaemia: conditioning with reduced doses of cyclophosphamide without radiation.

Nine patients with Fanconi anaemia (FA) were conditioned for HLA-identical sibling bone marrow transplant (BMT) with reduced dose of cyclophosphamide (Cy) without radiation or antithymocyte globulin (ATG). The total dose of Cy was 140 mg/kg (n = 2) or 120 mg/kg (n = 7). The median patient age was 8 years (range 4-19). Graft-versus-host disease (GVHD) prophylaxis was with methotrexate and cyclosporine (n = 8) or cyclosporine alone (n = 1). All patients had sustained engraftment and two developed grade>/= II acute GVHD. Cy toxicity included grade >/= 2 mucositis seen in all evaluable patients and haemorrhagic cystitis in two patients. The Kaplan-Meler survival estimate is 89% with a median follow-up of 285 d (range 56-528). For the purpose of comparison, this report also reviews and updates long-term follow-up data on 32 previously reported FA patients conditioned with 140-200 mg Cy/kg without radiation. The lowest dose of Cy (without radiation or ATG) after which HLA-identical sibling marrow transplant can be successfully performed in FA patients has yet to be determined, but it appears that uniform and sustained engraftment can be achieved with a Cy dose of as low as 120 mg/kg.

Adolescent↗
PubMed1996

Generation of activated natural killer (A-NK) cells in patients with chronic myelogenous leukaemia and their role in the in vitro disappearance of BCR/abl-positive targets.

Activated natural killer (A-NK) cells, a subset of CD56(dim)CD3- lymphocytes, are obtained from PBMC of normal donors by adherence to plastic and culture in the presence of IL2. In this study we tested the feasibility of generating A-NK cells in patients with Ph+ chronic myeloid leukaemia (CML). Cultures obtained from patients with early chronic phase (ECP; n=7) contained a mean (+/-SD) of83 +/- 7% of CD3- cells, and those from patients with advanced chronic phase (ACP; n=7) contained 27+/-33% CD56+CD3- cells. In three patients with leukaemia in a blastic phase (BP) it was only possible to obtain one culture enriched in CD56+CD3- cells (81%). Cellular aggregates of myeloid cells and large granular lymphocytes were observed in early A-NK cell cultures. Paired freshly-adherent and cultured A-NK cells were tested for the presence of BCR/abl mRNA by RT-PCR. The BCR/abl+ cells were detected in all 12 preparations of the freshly adherent A-NK cells tested. In 6/12 the BCR/abl+ cells were no longer detectable by RT-PCR on day 14 of culture. Both proliferation and antileukaemic cytotoxicity were significantly higher (P=0.002 and P=0.029, respectively) in the BCR/abl- cultures than those in the six BCR/abl+ cultures. 5/6 BCR/abl- cultures were highly enriched in A-NK cells on day 14, and 1/6 contained predominantly CD56+CD3+ cells. Only 2/6 BCR/abl + cultures were enriched in A-NK cells on day 14, but they had poor cytotoxicity and a low proliferative index. Myeloid cells (CD33+) were more frequently detected in the BCR/abl+ than BCR/abl- A-NK cell cultures (P=0.028). These observations suggest that: (1) populations of benign A-NK cells can be generated from the peripheral blood of CML patients; (2) the ability to generate A-NK cells is impaired in patients with advanced CML; and (3) the ability to generate A-NK cells with antileukaemic activity correlates with the disappearance of BCR/abl+ cells from these cultures.

Antigens, CD↗
PubMed1996

The 10-Mile Mourning Bridge and the Brief Symptom Inventory: close relatives?

One goal of this longitudinal bereavement study is to analyze the ability of a simple 0-10 visual analogue scale, the 10-Mile Mourning Bridge, to measure progress through bereavement. Based on a longitudinal study (n = 74 at posttest), Bridge results are significantly correlated with the General Severity Index, the strongest global indicator of the Brief Symptom Inventory (BSI, Derogatis & Spencer, 1982). The self report Bridges are significantly related to 8 of the 9 clinical scales of the BSI (Depression, Obsessive/Compulsiveness, Anxiety, Phobic Anxiety, Hostility, Psychoticism, Paranoia and Somaticism). Uses of the 10-Mile Mourning Bridge in daily hospice work are discussed.

Adaptation, Psychological↗
PubMed1996

Pharmacoeconomic comparison of loop diuretics in the treatment of congestive heart failure.

As MCOs explore opportunities for delivering more cost-effective medical care, prioritization based on drug utilization reviews alone may not adequately highlight those disease states that consume a disproportionate share of overall resource cost; the daily cost of pharmacotherapy may not reflect the overall economic effect. As the elderly proportion of the population grows, the treatment of congestive heart failure may represent for MCOs an increasingly important opportunity to achieve acceptable or even improved outcomes while controlling the costs of hospitalization and other resources. The introduction of new pharmaceuticals presents an ongoing challenge for managed care to determine whether they offer a pharmacoeconomic advantage over current treatment regimens. This paper reports on an economic assessment made between a new and an existing loop diuretic in the treatment of congestive heart failure.

Aged↗
PubMed1996

Pitfalls and outcomes from accelerated wear testing of mechanical heart valves.

In 1990 Sorin Biomedica introduced a new bileaflet heart valve called the Bicarbon valve. This design was reported to eliminate wear in the hinge mechanism. Clinical quality Sorin Bicarbon, CarboMedics, St. Jude Medical, Duromedics and Jyros valves were obtained to test this claim and to compare the wear in the pivot of this new valve to other available heart valves. The valves were visually inspected then subjected to 4,000 cycles at a physiological beat rate in vitro. The valves were re-inspected then subjected to 400 million cycles in a Reul type accelerated wear tester. Scanning electron microscope photographs were taken of all contact areas at 40, 80, 120, 160, 200, 240, 280 and 400 million cycles. Wear marks on the inflow side of the Sorin, CarboMedics and St. Jude leaflets were measured and compared. Orifice wear was not quantified because of difficulty with measuring inside complex depressions. After 4,000 cycles of testing at a physiological beat rate the CarboFilmTM coating on the Sorin orifice showed signs of erosion. The other valve components only exhibited minor burnishing after 4,000 cycles. Following completion of 400 million cycles in an accelerated wear tester, approximately ten years in vivo, all valves showed significant wear. The inflow face of the pivot on the Sorin Bicarbon leaflets exhibited the deepest wear marks. The CarboFilm coating on the Sorin Bicarbon orifices was removed from most areas of leaflet contact. The transition between the remaining coating and the eroded areas created a rough edge. The tips of the Sorin leaflets contacted the bottom of the orifice pivot, in contrast to the St. Jude Medical and CarboMedics designs, which had minimal contact between the leaflet and the orifice.

Biocompatible Materials↗
PubMed1995

An application of decision theory to patient screening for an autologous tumour vaccine trial.

Patients are eligible for accrual onto a phase I autologous tumour vaccine clinical trial if their resected and dissociated tumour achieves a minimum viable cell count. Because tumour pre-processing and cell count determination are expensive, there has been developed a screening procedure based on tumour mass to screen out those tumours unlikely to yield sufficient viable cells. If theta is the ratio of the expected benefit of an accrual onto the study to the cost of tumour pre-processing and cell counting, then we maximize long-run benefit by pre-processing and counting only those tumours whose masses exceed a cutoff mc, such that Pr(sufficient tumour cells masses = mc) = 1/theta. We derive algorithms for estimating mc and evaluate them under a variety of assumptions concerning the cell count/mass relationship. These include explicit equations for mc under parametric assumptions as well as more general algorithms based on non-parametric smoothing techniques. We show that when theta deviates substantially from 2, these methods outperform simple inverse interpolation.

Adenocarcinoma↗
PubMed1995

Granular cell tumor of penis and scrotum.

Two cases of granular cell tumor of the external male genitalia are reported: one on the scrotum and one on the shaft of the penis. No previous reports of granular cell tumor of the scrotum appear in the literature. Each tumor was treated by simple excision and there was no recurrence. Each tumor showed cytoplasmic S-100 positivity. Tumor was seen in close proximity to small nerve fibers, sweat glands, and erectile smooth muscle. These findings are considered encroachments rather than evidence of origin from any of these structures. An immunohistochemical signature for granular cell tumor has developed in recent years, but, from a practical viewpoint, only the S-100 stain should be used for confirmation of the diagnosis.

Adult↗
PubMed1995

Incidence of human immunodeficiency virus-related and nonrelated malignancies in a large cohort of homosexual men.

PURPOSE: To determine if the rates of malignancies other than Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL) are increased in human immunodeficiency virus (HIV)-infected homosexual men. SUBJECTS AND METHODS: From 1984 through 1993, 1,199 homosexual men were studied in the Pittsburgh component of the Multicenter AIDS Cohort Study (MACS), an examination of the natural history of HIV infection. The cohort consisted of 769 HIV-seronegative (SN) participants and 430 seropositive (SP) members who were either seroprevalent at the time of enrollment or who seroconverted during the study. Cancer incidence data were collected through semiannual visits, phone interviews, medical records, and death certificates. Five thousand seven hundred eight person-years and 2,344 person-years were contributed to the study by the SN and SP men, respectively. RESULTS: In addition to 44 cases of KS, 13 NHLs, and 3 CNS lymphomas (CNSLs), 27 other malignancies occurred (three nonmelanoma skin cancers and eight other malignancies in the SP group, eight nonmelanoma skin cancers, and eight other malignancies in the SN group). Age-adjusted rates were calculated for both groups and compared with each other and with rates for the general male population in Pennsylvania. There were no differences between the SN group and the general population. Among the SP group, the combined frequency of all cancers other than KS, NHL, CNSL, and nonmelanoma skin cancers was statistically significantly increased in comparison to both the SN group and the general population. This increase was secondary to an unusually increased frequency of both seminoma and Hodgkin's disease. CONCLUSION: These findings support the hypothesis that the incidences of cancers other than KS and lymphoma are moderately increased in the setting of HIV infection and immunosuppression.

Adolescent↗
PubMed1995

Incorporating toxicity considerations into the design of two-stage phase II clinical trials.

Phase II study designs are proposed that evaluate both clinical response and toxicity, and that are similar in structure to Simon's two-stage designs. Sample sizes and decision criteria are chosen to minimize the maximum expected accrual, given that the treatment is unacceptable either in terms of clinical response or toxicity. This is achieved subject to control of error rates, either uniformly over all possible correlation structures linking response and toxicity, or alternatively, under an assumption of independence between response and toxicity. In the latter case, bounds on the error rates show that effective control is still uniformly achieved even if the independence assumption is relaxed.

Biometry↗