Biomedical subjects
Publications and source records attributed to L Harrison.
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Funisitis, inflammation of the umbilical cord, is well recognized in human placentas. This report describes a case of funisitis associated with leptospiral infection in the placenta of a Thoroughbred foal born prematurely. The umbilical cord had diffuse superficial yellow discoloration along its entire length. Microscopic evaluation showed an exudate of neutrophils admixed with fibrin on the surface. Warthin-Starry staining showed spirochetes in the Wharton's jelly of the umbilical cord. A locally extensive, severe placentitis not involving the star and allantoic cystic hyperplasia were the other lesions observed in the allantochorion. Leptospira funisitis is similar to the funisitis of congenital syphilis in humans, although there are some major microscopic differences. In Leptospira funisitis, lesions were limited to the cord surface, whereas in lesions in human umbilical cords with Treponema pallidum infection, the changes are observed mostly around the vessels and in the Wharton's jelly.
Reduced intensity (RI) allogeneic stem cell transplantation (AlloSCT) was initially demonstrated in adults following HLA-matched family and unrelated adult donor AlloSCT. There is little information about RI AlloSCT in children. We report results of a pilot study of RI AlloSCT in 21 recipients (< or =21 years). Age: median 13 (0.5-21) years, 8F:13M, 14 unrelated cord blood units (UCB) (10 4/6, 4 5/6), two related BM (6/6, 5/6), four related PBSC (2 6/6, 2 5/6), and one related BM+PBSC (6/6). RI: fludarabine, busulfan (n=14); fludarabine, cyclophosphamide (n=4); fludarabine, melphalan (n=1); total body irradiation, fludarabine, cyclophosphamide (n=1); or fludarabine, cyclophosphamide, and etoposide (n=1). Graft-versus-host disease prophylaxis: FK506 0.03 mg/kg/day and mycophenolate mofetil 15 mg/kg/q 12 h. UCB median nuc/kg and CD34/kg was 4.3 x 10(7)/kg (0.9-10.8) and 1.9 x 10(5)/kg (0.3-6.9), and related BM/PBSC median nuc/kg and CD34/kg was 8.3 x 10(8) (4.7-18.9) and 5.0 x 10(6)/kg (4.6-6.4). Maximal chimerism following unrelated cord blood transplantation, 100% x 7, 98% x 1, 95% x 2, 55% x 1, and 0% x 3; related PBSC/BM, 100% x 5, 65% x 1, and 55% x 1. Graft failure occurred in 5/21 (24%). In summary, RI AlloSCT in children is feasible and tolerable (< or =25% GF) and results in > or =85% of recipients initially achieving > or =50% donor chimerism.
We report results of unrelated cord blood transplants (UCBT) in 29 pediatric recipients in one center and the risk factors associated with survival. Median age: 9 years (0.5-20); diagnosis: ALL (9), AML (4), CML (1), HD (3), HLH (1), NHL (3), NBL (2); B-thal (1), FA (1), FEL (1), Krabbe (1), WAS (1), SAA (1); median follow-up: 11 months; conditioning: total body irradiation (TBI)-ablative (14), chemotherapy-ablative (6) and reduced intensity chemotherapy (9); GVHD prophylaxis: MMF/FK506 (18), cyclosporin A (CsA)+steroids+/-MMF (7) or CsA+methotrexate (MTX) (4); median total nucleated cells (TNC): 3.8 x 10(7)/kg (1.1-11); median CD34+: 2.3 x 10(5)/kg (0.2-9.9); and HLA match: 2 (6/6), 5 (5/6), 22 (4/6). Neutrophil engraftment by cumulative incidence curves 63% (median 28 (95% confidence interval (CI) 18-32)). Probability of >/=grade II acute graft-versus-host disease (aGVHD) by day +60 27%, >/=grade III aGVHD 20% and chronic graft-versus-host disease 3%. Estimated 1-year overall survival (OS) 46% (95% CI 30-71) and standard risk 60% (95% CI 29-100%). Variables associated with improved survival by multivariate analysis include non-TBI-ablative conditioning (P=0.024), CD34+/kg (P=0.038) and gender (P=0.048). These results suggest that CD34/kg cell dose and non-TBI-ablative conditioning may be important variables influencing OS following UCBT in pediatric recipients. Given the small number of patients, these results should be viewed cautiously.
Changes within the Australian health care system have led many people with mental health disorders to use emergency departments as the point of access to mental health services. Staff in emergency departments are not necessarily equipped to assess the needs of such clients. This paper briefly describes the development of a multidisciplinary mental health liaison team, within the emergency department of one hospital in Sydney, which was designed to assist both staff and clients. Available evidence suggests the implementation of the team has been a success, however, more research is required to confirm the effectiveness of this approach. Questions are raised about appropriate referral and follow-up for some clients. The study also found deficiencies in the method of routine data collection (Emergency Department Identification System), which makes formal auditing of the team and the services it provides a difficult task.
Hepatitis C virus (HCV) poses a major public health problem world wide. The introduction of combined therapy (interferon and ribavirin) and the recent development of pegylated interferon have offered the opportunity to alter the natural history of HCV, potentially reducing morbidity and mortality. Until recently, treatment has been confined to larger Australian cities. This paper describes the establishment of a clinic for the treatment of HCV in a regional Australian city. The facilities of the sexual health clinic were utilised. Factors contributing to the success of the clinic include the specialist nurse, a multidisciplinary approach, and the service model of shared care with general practitioners. The patient population and the outcomes of managing HCV in a regional centre are described. The sustained viral response rate is comparable to the published data from specialist centres.
We propose the use of multivariate autoregressive (MAR) models of functional magnetic resonance imaging time series to make inferences about functional integration within the human brain. The method is demonstrated with synthetic and real data showing how such models are able to characterize interregional dependence. We extend linear MAR models to accommodate nonlinear interactions to model top-down modulatory processes with bilinear terms. MAR models are time series models and thereby model temporal order within measured brain activity. A further benefit of the MAR approach is that connectivity maps may contain loops, yet exact inference can proceed within a linear framework. Model order selection and parameter estimation are implemented by using Bayesian methods.
In this paper we present an approach to the identification of nonlinear input-state-output systems. By using a bilinear approximation to the dynamics of interactions among states, the parameters of the implicit causal model reduce to three sets. These comprise (1) parameters that mediate the influence of extrinsic inputs on the states, (2) parameters that mediate intrinsic coupling among the states, and (3) [bilinear] parameters that allow the inputs to modulate that coupling. Identification proceeds in a Bayesian framework given known, deterministic inputs and the observed responses of the system. We developed this approach for the analysis of effective connectivity using experimentally designed inputs and fMRI responses. In this context, the coupling parameters correspond to effective connectivity and the bilinear parameters reflect the changes in connectivity induced by inputs. The ensuing framework allows one to characterise fMRI experiments, conceptually, as an experimental manipulation of integration among brain regions (by contextual or trial-free inputs, like time or attentional set) that is revealed using evoked responses (to perturbations or trial-bound inputs, like stimuli). As with previous analyses of effective connectivity, the focus is on experimentally induced changes in coupling (cf., psychophysiologic interactions). However, unlike previous approaches in neuroimaging, the causal model ascribes responses to designed deterministic inputs, as opposed to treating inputs as unknown and stochastic.
This paper seeks to import a more complex understanding of gendered subjectivity into discussions of young people and homosexuality, and is based on an Australian national survey (n=749) of same-sex attracted youth (SSAY) aged between 14 and 21. Results revealed significant gender differences with regard to patterns of sexual attraction, behaviour and identity labels among participants. For the young men in the study, there was more congruence between feelings of gender a-typicality, same-sex attractions and same-sex behaviours. Overall, young women displayed more fluidity with regard to their sexual feelings, behaviours and identities. Young women were more likely to be engaged in private explorations of lesbianism, concurrent with participation in heterosexual sex and relationships. Young women were also grappling with more limited and emotionally risky opportunities for sex with other girls who were already known to them as friends. The invisibility of lesbianism as an identity or practice led to confusion about what feelings meant for the future in the arena of lived experience. The paper concludes that more research is needed into the impact of gender on the development of young people's experiences of homosexuality, particularly the manner in which invisibility and lack of social acceptance of a full spectrum of sexual diversity may disadvantage young women's emotional health and well-being.
The present study set out to estimate the prevalence of bereavement experiences in adolescents, the association between these experiences and depressive symptoms and the attitudes of bereaved young people to professional interventions. The study was based on 1746 adolescents aged between 11 and 16 years from two secondary schools in Northern England. Questionnaire measures of bereavement experiences and depressive symptoms were completed by the adolescents in the classroom. One thousand three hundred and fifty-five (77.6%) reported that at least one of their first-or second-degree relatives or close friends had died. These losses were associated with increased levels of depressive symptoms in comparison with the loss of other relatives or pets. The impact of the loss of someone close depended to an important extent on the young person's perception of how the loss had changed their lives. Most adolescents did not feel the need for professional services. Those who did use these services had higher levels of depressive symptoms, suggesting that service use was likely to have been appropriate.
Anemia is associated with reduced local tumor control and impaired quality of life in patients with several types of solid tumors. The prevalence of anemia in patients who present at radiation oncology departments has not been well documented, and the impact of anemia on the outcome of radiation therapy is not widely appreciated in the radiation oncology setting. In an ongoing study, we are retrospectively reviewing the medical charts of patients before and after radiation therapy at our institutions to determine the magnitude of the anemia problem in this population. Preliminary data are available for 574 randomly selected patients (52% female) seen between December 1996 and June 1999. At presentation, 41% of all patients were anemic (hemoglobin < 12 g/dL); by the end of radiation therapy, this percentage increased to 54%. The most common tumor types were prostate (16%), breast (14%), head and neck (12%), colorectal (11%), lung/bronchus (11%), and uterine-cervix (9%). Anemia was most prevalent in patients with uterine-cervical tumors (75%), increasing to 79% by the end of radiation therapy. The prevalence of lung/bronchus and colorectal cancer was 55% and 44%, respectively, at baseline and increased to 77% and 63%, respectively, after radiation therapy. For nearly all tumor types, the majority of patients had or developed mild to moderate anemia (hemoglobin 10.0 to 11.9 g/dL). These data show that anemia is widespread among patients seen in radiation oncology practices. However, the anemia is usually mild and readily correctable. Because anemia and hypoxia possibly associated with anemia are obstacles to local tumor control and maintenance of quality of life, strategies to reverse anemia should receive greater attention.
Group B streptococci (GBS) are important pathogens in neonatal sepsis and pneumonia. GBS stimulate alveolar macrophages to produce inflammatory cytokines and free oxygen radicals, which can damage the lungs. In several studies, use of exogenous surfactant in term babies has improved outcome related to sepsis and respiratory failure. The role(s) of exogenous surfactant in modulating the inflammatory response produced by this microbe was examined. Tumor necrosis factor alpha (TNF-alpha) production and luminol-enhanced chemiluminescence (LCL), a measure of respiratory burst, were investigated. For measuring TNF-alpha release, RAW 264.7 murine macrophages were pre-incubated with bovine surfactant and stimulated with either lipopolysaccharide, live or heat-killed GBS type Ia. LCL was measured after macrophages were pre-incubated with or without surfactant overnight, then stimulated with GBS or phorbol myristate acetate. Lipopolysaccharide and GBS stimulated TNF-alpha secretion from macrophages that was suppressed by exogenous surfactant in a dose-dependent fashion. GBS and phorbol myristate acetate also increased LCL from macrophages, which was significantly suppressed by pre-incubation of macrophages with exogenous surfactant. We conclude that GBS type Ia stimulates TNF-alpha release and LCL from RAW 264.7 cells and that these responses are suppressed by surfactant. Suppression of inflammatory mediators by exogenous surfactant might improve respiratory disease associated with GBS.
In the Australian College of Midwives, Code of Ethics, Section 11. Practice of Midwifery, the following is stated "A. Midwives provide care for women and childbearing families with respect for cultural diversity while also working to eliminate harmful practices within those same cultures." However, it is difficult to know what is meant by "respect for cultural diversity". This paper presents the results of a critical review of the health literature. There is surprisingly little consensus about the meaning of terms such as cultural sensitivity and cultural appropriate care. Nor are there reflections on incorporating these concepts into practice. It could be argued that until there is greater clarity about these concepts and more discussion of how they may be used in practice, midwives would have to continue to rely on their individual knowledge and experience.
AIM OF STUDY: This study investigated the perceptions of alcohol and other drug (AOD) clinicians and consumers regarding the concepts of collaboration and empowerment. BACKGROUND/RATIONALE: Working collaboratively is seen as a cornerstone of empowerment, a concept used extensively over the last decade in an attempt to isolate power and control issues. It is generally assumed that health professionals strive to achieve collaboration, but little research has been undertaken. DESIGN/METHODS: The study was carried out in a variety of AOD treatment facilities in a large regional city in Australia. Facilities included an inpatient detoxification unit, an outpatients' clinic, a methadone maintenance clinic, a residential detoxification and rehabilitation unit using a 12-step treatment model and a residential unit using cognitive behavioural therapy (CBT). The nonprobability sample consisted of 57 staff and consumers who were interviewed using a semi-structured format. Data were analysed thematically using a Foucauldian analysis of discourse. RESEARCH FINDINGS: Findings suggest that clinicians may be unwittingly imposing their beliefs and prejudices on consumers and in fact disempowering the very people they want to empower. Collaboration is not happening. Foucault's theory of objectification illuminates the processes involved. CONCLUSIONS: There is much more happening than originally thought between consumers and staff when Foucault's three modes of objectification are used to examine this practice area. Analysing discourse enables us to see how health workers interact with consumers and the effect this may have on treatment objectives, outcomes and self-esteem. It also illuminates the work environment where the therapeutic encounter takes place. The need for further effort in empowering both consumers and staff and working collaboratively becomes evident.
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BACKGROUND: Surgical resection of malignant pleural mesothelioma is reported to have up to an 80% rate of local recurrence. We performed a phase II trial of high-dose hemithoracic radiation after complete resection to determine feasibility and to estimate rates of local recurrence and survival. METHODS: Patients were eligible if they had a resectable tumor, as determined by computed tomographic scanning, and adequate cardiopulmonary function for extrapleural pneumonectomy or pleurectomy/decortication. After complete resection, patients received hemithoracic radiation (54 Gy) and then were followed up with serial computed tomographic scanning. RESULTS: From 1995 to 1998, 88 patients (73 men and 15 women; median age, 62.5 years) were entered into the study. The operations performed included 62 extrapleural pneumonectomies (70%) and 5 pleurectomies/decortications; procedures for exploration only were performed in 21 patients. Seven (7.9%) patients died postoperatively. Adjuvant radiation administered to 57 patients (54 undergoing extrapleural pneumonectomy and 3 undergoing pleurectomy/decortication) at a median dose of 54 Gy was well tolerated (grade 0-2 fatigue, esophagitis), except for one late esophageal fistula. The median survival was 33.8 months for stage I and II tumors but only 10 months for stage III and IV tumors (P =.04). For the patients undergoing extrapleural pneumonectomy, the sites of recurrence were locoregional in 2, locoregional and distant in 5, and distant only in 30. CONCLUSION: Hemithoracic radiation after complete surgical resection at a dose not previously reported is feasible. This approach dramatically reduces local recurrence and is associated with prolonged survival for early-stage tumors. Stage III disease has a high risk of early distant relapse and should be considered for trials of systemic therapy added to this regimen of resection and radiation.
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Energy from low LET ionising radiation, such as X rays and gamma rays, is deposited in the water surrounding the DNA molecule such that between 2 to 5 radical pairs are generated within a radius of I to 4 nm. As a result, multiple single lesions, including oxidised purine or pyrimidine bases, sites of base loss, and single-strand breaks, can be formed in DNA from the same radiation energy deposition event. The single lesions in these so-called multiply damaged sites or clustered lesions are repaired by base excision repair. Here we show that clustered DNA damages are formed in bacterial cells by ionising radiation and are converted to lethal double-strand breaks during attempted repair. In wild type cells possessing the oxidative DNA glycosylases that recognise and cleave DNA at repairable single damages, double-strand breaks are formed at radiation-induced clusters during post-irradiation incubation and in a dose-dependent fashion. Mutant cells lacking these enzymes do not form double-strand breaks post-irradiation and are substantially more radioresistant than wild type cells. These radioresistant mutant cells can be made radiosensitive by overexpressing one of the oxidative DNA glycosylases. Thus the effect of the oxidative DNA glycosylases in potentiating DNA damage must be considered when estimating radiation risk.