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Biomedical subjects

L Mason

Publications and source records attributed to L Mason.

At least 19 recordsLinked to original sources
PubMed2000

Defining mechanisms of action of interleukin-11 on the progression of radiation-induced oral mucositis in hamsters.

Oral ulcerative mucositis is a common toxicity associated with drug and radiation therapy for cancer. It impacts on quality of life and economic outcomes, as well as morbidity and mortality. Mucositis is often associated with dose limitations for chemotherapy or is a cause for dose interruption for radiation. The complexity of mucositis as a biological process has only been recently appreciated. It has been suggested that the condition represents a sequential interaction of oral mucosal cells and tissues, pro-inflammatory cytokines and local factors such as saliva and the oral microbiota. The recognition that the pathophysiology of mucositis is a multifactorial process was partially suggested by the observation that interleukin-11 (IL-11), a pleotropic cytokine, favorably altered the course of chemotherapy-induced mucositis in an animal model. In the current study, we evaluated a series of biologic and morphologic outcomes to determine their roles and sequence in the development of experimental radiation-induced mucositis and to evaluate the effects of IL-11 in attenuating them. Our results suggest that IL-11 favorably modulates acute radiation-induced mucositis by attenuating pro-inflammatory cytokine expression. Data are also presented which help define the pathobiological sequence of mucositis.

Animals↗
PubMed1999

The role of LY49 NK cell subsets in the regulation of murine cytomegalovirus infections.

The distributions and functions of NK cell subsets, as defined by the expression of Ly49 NK cell receptors, were examined in murine CMV (MCMV)-infected mice. MCMV induced a reduction in NK1.1+ cell number in the spleen and an increase in the peritoneal exudate cells. Within the splenic NK1.1+ population, proportional increases in Ly49A+ and Ly49G2+ cells but decreases in Ly49C+ and Ly49D+ cells were observed 3 days post-MCMV infection, but within the peritoneal NK1.1+ cell populations there were proportional decreases in Ly49A+ cells and increases in Ly49C+, Ly49D+, and Ly49G2+ cells. Lymphocytic choriomeningitis virus did not elicit a comparable NK cell subset distribution. Lymphokine-activated killer cells were sorted into different Ly49 NK cell subsets and adoptively transferred into C57BL/6 suckling mice. Regulation of MCMV synthesis in these suckling mice was shown to be an IFN-gamma-dependent, perforin- and Cmv-1-independent process, and each NK cell subset mediated anti-viral activity. In adult C57BL/6 mice, the control of MCMV in the spleen is mediated by a perforin-dependent mechanism, regulated in part by the Cmv-1 gene, which maps closely to the Ly49 family. In vivo depletions of either one or two of the Ly49 subsets in adult mice did not affect the ability of the residual NK cells to regulate MCMV synthesis. These data provide evidence of NK cell subset distribution and function in MCMV infection, but no individual subset was required for the Cmv-1-like regulation of MCMV synthesis.

Adoptive Transfer↗
PubMed1999

The prevalence of stress incontinence during pregnancy and following delivery.

OBJECTIVES: To examine the variation in findings from epidemiological studies which describe the prevalence of stress incontinence during and after pregnancy, and to undertake a prospective survey of the prevalence of stress incontinence during pregnancy and following childbirth in order to provide clarification of the findings presented in the literature. DESIGN: A review of the literature was undertaken using the Medline and Popline CD Rom. A postal questionnaire was sent to a sample of women when they reached 34 weeks' gestation and repeated at 8 weeks postpartum. PARTICIPANTS: 1008 women were recruited to the study when they attended the antenatal clinic at two hospitals in the north west of England. Seven hundred and seventeen (71%) women responded to the first questionnaire and 572 (57%) completed the second questionnaire. FINDINGS: The prevalence of stress incontinence during pregnancy reported in the literature ranges from 20 to 67%. Following delivery the reported prevalence is between 6 and 29%. In the present study 59% of women reported stress incontinence during pregnancy, and 31% following delivery. Ten per cent of the women had daily episodes of incontinence during their pregnancy, 2% of all women reported daily incontinence following delivery. An association was found between parity and stress incontinence, with women of higher parity being more likely to experience the condition. No difference in the prevalence of stress incontinence was found between women who had a normal delivery and those having an instrumental delivery. A caesarean section was found to be associated with a lower incidence of stress incontinence compared with a normal spontaneous delivery. KEY CONCLUSION: A high proportion of women experienced stress incontinence during pregnancy and/or following delivery. Some women reported severe symptoms, with leakage on a daily basis. Women of higher parity were more likely to suffer from the condition. Whilst women who had a normal spontaneous delivery or an instrumental delivery reported a similar level of stress incontinence, women who had a caesarean section were less likely to have the condition.

Adult↗
PubMed1999

The feasibility of using automated data to assess guideline-concordant care for schizophrenia.

This study examines the feasibility of using automated computer data versus written medical record data to identify patients receiving guideline concordant treatment for schizophrenia. Central elements of care derived from published practice guidelines for schizophrenia were examined for a convenience sample of 28 patients who received acute inpatient treatment. The results showed that automated data were superior to medical record data for identifying some elements of guideline-concordant treatment. Not only were the elements of care examined in this study clinically significant and within the current capabilities of the existing computer information system, but they are also likely related to patient outcomes. Implications for clinical care, future research, and health care quality improvement efforts are discussed.

Adult↗
PubMed1999

Organizational culture and staff outcomes in services for people with intellectual disabilities.

Organizational culture has been shown by organizational psychology to influence important aspects of staff behaviour. In particular, mismatches between staff perceptions of real and ideal organizational cultures have been shown to be associated with a range of negative outcomes for staff, such as stress, sickness and staff turnover. The present study investigates organizational culture in services for people with intellectual disabilities. The aim was to discover the prevalent organizational cultures in these services, and associations between organizational culture and staff outcomes. As part of a large-scale survey of staff in services for people with intellectual disabilities, information concerning organizational culture and staff outcomes was collected from 450 staff. A self-report measure of real and ideal organizational culture produced nine dimensions of organizational culture: (I) tolerant/staff-oriented; (2) achievement-oriented; (3) innovative; (4) analytical; (5) social relationships; (6) rewarding staff; (7) stable work environment; (8) demanding; and (9) conflict management. These nine dimensions of organizational culture showed generally adequate psychometric properties. While there was some variation in organizational culture across services, there is little variation across staff with different job titles. Overall, the staff rated real organizational cultures to be relatively high in achievement orientation and fostering social relationships, and relatively low in managing conflict and providing rewards for staff. Staff rated ideal organizational cultures to be high in rewarding staff, being tolerant/staff-oriented and fostering social relationships, and low in demands on staff. Except for the dimension of making demands on staff, where staff rated organizations as considerably higher than ideal, staff generally rated organizations as being less than ideal on all dimensions of organizational culture. Organizational psychology theory predicts that poor 'person-organization fit' (i.e. a greater mismatch between real and ideal organizational culture) will be associated with a range of negative staff outcomes. This theory was largely supported by findings of the present study. The implications for practice and for future research are discussed.

Adaptation, Psychological↗
PubMed1999

Factors associated with staff stress and work satisfaction in services for people with intellectual disability.

Staff stress and morale have been identified as major issues affecting the quality of services for people with intellectual disability. The present study investigates factors directly and indirectly associated with staff general distress, job strain and work satisfaction amongst staff in services for people with intellectual disability. As part of a large-scale survey of staff in services for people with intellectual disability, information was collected from 450 staff concerning general distress, job strain and work satisfaction, and a wide range of factors potentially associated with these outcomes. Path analyses revealed that three factors accounted for 28% of the variance in general distress scores: (I) wishful thinking, (2) stress linked to work-home conflict and (3) role ambiguity. Six factors accounted for 50% of the variance in job strain scores: (I) wishful thinking, (2) stress linked to a lack of staff support, (3) alienative commitment, (4) role ambiguity, (5) stressors linked to a low status job and (6) working longer contracted hours. Six factors accounted for 66% of the variance in work satisfaction scores: (I) stress linked to a low status job, (2) support from supervisors, (3) influence over work decisions, (4) alienative commitment, (5) support from colleagues and (6) older staff age. A range of factors indirectly associated with the three outcome measures was also identified. The models of general distress, job strain and work satisfaction empirically derived in the present study confirm and extend previous research in this area. The implications for organizations and future research are discussed.

Adult↗
PubMed1999

The experience of stress incontinence after childbirth.

BACKGROUND: Epidemiological studies have reported prevalence of stress incontinence ranging from 23 to 67 percent during pregnancy and 6 to 29 percent after childbirth, but little is known about how the condition affects women at this time. The purpose of this study was to examine the effects of stress incontinence on women in their childbearing years. METHODS: Interviews were conducted with 42 women who experienced stress incontinence at 8 weeks postpartum and 15 women who reported symptoms one year after delivery. Analysis of the qualitative data involved exploring themes and patterns, relationships and connections, contradictions and contrasts, and the language used within individual accounts and across the spectrum of narratives. RESULTS: The results are presented within a framework that the women themselves adopted: day-to-day activities, putting the condition in some form of perspective, and feelings and emotions. For some women, stress incontinence had a great impact on their lives in terms of both their daily routine and psychologically, but others described it as a minor inconvenience that rarely disturbed their routine. Major concerns comprised the restrictions placed on the women, the worry or continual awareness stemming from the condition, and feelings of embarrassment associated with it. Twelve months after childbirth the effects appeared to have lessened, but a few women were still significantly affected, both physically and psychologically. CONCLUSIONS: Although many women experience physical and psychological symptoms of stress incontinence after delivery, this study demonstrated that few sought professional care or advice for their symptoms. Health professionals should be aware of the prevalence, and women's responses to, stress incontinence so that they can initiate appropriate support and care. Further research on stress incontinence on childbearing women is necessary.

Activities of Daily Living↗
PubMed1998

Differential effects of the rejection of bone marrow allografts by the depletion of activating versus inhibiting Ly-49 natural killer cell subsets.

Natural killer cells mediate the specific rejection of bone marrow cell (BMC) allografts in lethally irradiated mice. The Ly-49 family of molecules present on subsets of murine NK cells appears capable of binding class I MHC molecules, resulting in transmission of an inhibitory signal to the NK cell. These Ly-49 family members have been shown to have an immunoreceptor tyrosine-based inhibitory motif that is responsible for the inhibitory signal. However, a new Ly-49 family member was found that lacks this motif, Ly-49D, and evidence suggests that this may be an activating receptor. We therefore compared the role of the activating Ly-49 member with NK cells bearing inhibitory Ly-49 receptors in BMC rejection. Depletion of Ly-49D+ NK cells in H-2b mice abrogated their ability to reject H-2d BMC allografts. Similarly, Ly-49C+ NK cells also were shown to mediate the specific rejection of H-2d BMC. When both subsets were depleted, an additive enhancement of BMC engraftment was observed, indicating that both subsets play a role in the rejection of allogeneic H-2-homozygous H-2d BMC. However, rejection of H-2(b x d) or D8 (H-2b, Dd transgene) BMC allografts was unaffected by Ly-49C+ NK cell depletion in H-2b mice. In marked contrast, depletion of Ly-49D+ NK cells in H-2b mice totally abrogated the rejection of H-2(b x d) heterozygous BMC in support of in vitro data suggesting that Ly-49D+ NK cells receive activating signals. Therefore, NK subsets demonstrate a differential ability to reject H-2 homozygous and heterozygous BMC.

Animals↗
PubMed1998

Work transitions.

The healthcare environment is changing rapidly. Work reorganization and redesign can lead to department and unit closures, resulting in work transitions for many staff members. The authors describe the findings of focus groups held with staff and management on units that have closed. These interviews highlight the difficulties encountered with change and provide suggestions to reduce uncertainty during department or unit closures.

Academic Medical Centers↗
PubMed1998

Social network factors associated with perceived quality of life. The San Luis Valley Health and Aging Study.

Demographic and social network factors associations with perceived quality of life (PQOL) were examined in a sample of rural Hispanic and non-Hispanic White (NHW) elderly. A 20-item PQOL scale measured participants' satisfaction with multiple facets of their lives. Age, gender, marital status, and living alone were not associated with this outcome. Hispanic persons with higher incomes had consistently higher ratings of quality of life compared to NHWs. More education was associated with a higher PQOL rating only among NHWs. More close friends and relatives, visiting in homes, and participation in outside activities were all independently related to PQOL. Interaction tests showed that the impact of social networks was stronger in NHWs. These findings suggest that network size and contact are important social factors that can improve quality of life for both ethnic groups. However, differences may need to be examined when judging the magnitude of these associations and when planning interventions.

Aged↗
PubMed1998

Day surgery: improving care through follow up contact.

In this article I will outline the method of evidence based practice we have implemented during the last three years following the introduction of day surgery as a specific speciality in our Trust. I will outline the method of accessing information on a regular basis and how this information was used to improve the service we offer. Finally I will suggest how, as a group of professionals, we may take this initiative forward towards AD 2000.

Aftercare↗
PubMed1998

Client-centered care: Texas on the front line.

Client-centered care is a popular concept, particularly for consumers and the disabled community. Disability advocacy groups are focusing on client-centered care as a new concept that home care agencies should embrace to provide clients with more control over their care. However, implementing this strategy might not be as easy as it sounds.

Attitude to Health↗
PubMed1996

The prognostic significance of histomorphometry and immunohistochemistry in giant cell tumors of bone.

Eighty-two cases of giant cell tumor (GCT) were reviewed. Hematoxylin-eosin-and hematoxylin, phloxine, saffron, and alcian green-stained sections (82 cases) were examined for mitotic rate, the number of giant cells, and the pleomorphism of the stromal cells. In 29 cases, the tumor was stained for CD68, alpha 1-antichymotrypsin (AIACT), S100 protein, Muramidase, and von Willebrand factor (factor VIII). The staining properties of mononuclear and multinucleated giant cells were compared. Morphometric analysis was performed on 14 cases with a LECO 2001 computer-assisted image analyzer (LECO Instruments Ltd, Mississauga, Ontario, Canada) and included absolute cell count, nuclear area, perimeter, roughness, roundness, and aspect and nuclear versus cytoplasmic ratios, measured both in the stromal cells and giant cells. The cases were divided into four groups: (1) cases with metastasis, (2) cases with recurrence, (3) cases with both metastasis and recurrence, and (4) cases with neither metastasis nor recurrence. Immunohistochemistry revealed a stronger AIACT than muramidase positivity in general. The staining was stronger in stromal cells than in giant cells. Giant cells in all tumors were positive for CD68. Stromal cells showed weaker positivity for the same stain. The number of asymmetrical mitotic figures was significantly greater in group 3 than in group 4 (P < .05). Morphometric assessment has identified a statistically significant difference in the aspect ratio and the roundness of the nuclei between these two groups. The other parameters did not differ significantly. In this article, the significance of these findings in prognostication and the histogenesis of the giant cell tumor are discussed. Their clinical applicability is yet to be determined.

Adolescent↗
PubMed1996

Ly-49 G2+ NK cells are responsible for mediating the rejection of H-2b bone marrow allografts in mice.

NK cells can mediate the specific rejection of bone marrow but not solid tissue allografts in lethally irradiated mice. NK cells are also responsible for the phenomenon of "hybrid resistance' in which F1 hybrid H-2 heterozygous mice can reject parental H-2 homozygous bone marrow grafts. Ly-49C and Ly-49 G2 are markers identified on subsets of NK cells. While Ly-49C+ NK cells have been demonstrated to mediate the specific rejection of H-2d bone marrow allografts, the role of the Ly-49 G2+ NK subset is unclear because depletion of this subset in vivo did not affect splenic NK activity against tumor targets. Through bone marrow transplantation typing studies, we demonstrate that Ly-49 G2+ NK cells complement Ly-49C+ NK cells in that they specifically mediate the rejection of H-2b bone marrow allografts in lethally irradiated mice. In support of this, depletion of the Ly-49C+ NK subset in vivo also enhanced the ability of the mice to reject H-2b bone marrow cells suggesting that the depletion was augmenting the ability of the Ly-49 G2+ NK cells to reject the marrow allografts. Depletion of Ly-49 G2+ NK cells in F1 hybrid mice abrogated their ability to reject parental H-2b but not H-2d bone marrow grafts. Therefore, Ly-49 G2 denotes a subset of NK cells that appears to play a critical role in the recognition of H-2b bone marrow cells in allogeneic and F1 hybrid mice.

Animals↗
PubMed1995

NK cell subsets in the regulation of murine hematopoiesis. I. 5E6+ NK cells promote hematopoietic growth in H-2d strain mice.

NK cells are able to reject bone marrow allografts in lethally irradiated mice. 5E6 is a marker expressed on a subset of NK cells that is responsible for the rejection of H-2d homozygous bone marrow cell (BMC) allografts. This suggests that the 5E6+ NK cell subset somehow recognizes and is deleterious for H-2d BMC. However, unlike Ly-49+ NK cells, 5E6+ cells are not deleted or even down-regulated in H-2d-homozygous mice. We wanted to determine, therefore, the role of the 5E6+ and 5E6- NK cell subsets in the normal physiologic regulation of hematopoiesis in H-2d strains of mice. Surprisingly, both in vivo depletion studies of normal mice and studies in which the subsets were purified and cultured with syngeneic BMC in vitro demonstrated that in H-2d mice, the 5E6+ subset of NK cells did not inhibit, but instead promoted, growth of H-2d BMC. Depletion of the 5E6+ subset also resulted in decreased marrow engraftment after syngeneic bone marrow transplantation in H-2d mice. Analysis of the cell culture supernatants of the purified subsets indicated that the functional effects of the subsets on hematopoiesis correlated with the relative amounts of hematopoietic growth-promoting cytokines produced by the NK cells. These results demonstrate that physiologically relevant subsets of NK cells exist that are involved in the homeostatic regulation of hematopoiesis and that they can be distinguished on the basis of 5E6 expression.

Animals↗
PubMed1994

What about the health of ancillary staff? A management audit.

Health at Work in the NHS was launched at the same time as Health of the Nations, in July 1992. There is good national and local evidence identifying ancillary staff as a priority for health promotion. Despite the evidence, and a regional drive to make work with ancillary staff a priority, a recent audit made clear that very little has happened. Market testing seems to have excluded ancillary staff health from senior management responsibility. discusses possible reasons and the implications.

Allied Health Personnel↗