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Biomedical subjects

A Street

Publications and source records attributed to A Street.

88 records · Page 5Linked to original sources
PubMed1993

Stabilization of von Willebrand factor in banked blood by leucocyte depletion.

The von Willebrand factor (vWf) activity, as measured by the ristocetin co-factor (vWf:RCo) and collagen binding (vWf:CBA) assays, declined progressively in standard blood units stored at 4 degrees C after a 2-day storage period. This loss of activity was accompanied by a loss and degradation of high molecular weight (HMW) vWf multimers. In studies using a paired design, filtration of blood with a high efficiency leucocyte-removal filter, prior to storage at 4 degrees C, led to significantly improved maintenance of vWf:RCo and vWf:CBA compared with unfiltered units (P < 0.01 after 8 days). Loss and degradation of HMW vWf decreased when blood was filtered prior to 4 degrees C storage. Filtration had no effect on vWf-associated activities when blood was stored at 22 degrees C for 10 days. These results indicate that part of the storage lesion of vWf in banked blood is due to leucocyte-mediated removal and degradation of HMW vWf. This has implications when specifying plasma for the production of vWF concentrates and may also play a role in the haemostatic lesion associated with massive transfusion of stored blood.

Blood Banks↗
PubMed1992

von Willebrand factor characterization of a severe dry-heat treated factor VIII concentrate, AHF (high purity).

Eight batches of a severe dry-heat treated (80 degrees C for 72 hours) Factor VIII concentrate manufactured by the Commonwealth Serum Laboratories (CSL Ltd.) were analysed for the following von Willebrand factor-related (vWf) activities: ristocetin cofactor activity (vWf:RCof), collagen binding activity (CBA), vWf antigen levels (vWf:Ag), vWf multimeric analysis and 2-stage FVIII clotting activity (VIII:C). The average potency per vial of vWf:Ag was 440 +/- 80 units, vWf:RCof 500 +/- 60 units, CBA 350 +/- 50 units and VIII:C 242 +/- 36 International Units. Multimeric analysis indicated the presence of high molecular weight multimers and a triplet structure slightly different to normal plasma. Viral inactivation studies using a marker virus, Sindbis, demonstrated that the terminal severe dry- heating step reduced the viral load in the product by greater than 6 log10TCID50/ml. This CSL Ltd. FVIII concentrate may thus provide a safer, purer and more convenient source of vWf than cryoprecipitate. Clinical studies to establish product efficacy in patients with von Willebrand's disease are underway.

Blood Protein Electrophoresis↗
PubMed1992

The value of health care: what can we learn from Oregon?

The scarcity of health care resources leads to rationing amongst potential users by one means or another. When the market is rejected, rationing should be conducted on the basis of systematic and informed priority setting. It has been widely suggested that these priorities should be based on health benefits measured by quality adjusted life years (QALYs) and recently the US State of Oregon has attempted to use QALYs for setting priorities on a large scale. Values not normally associated with QALY analysis were also incorporated in the process. Their unique experience is of interest in Australia, as no attempt has been made here to prioritize medical interventions on the scale that was undertaken in Oregon.

Australia↗
PubMed1992

Increasing women's participation in Pap smear screening in Australia--how can we tell if the national policy is effective?

A national policy on the prevention of cervical cancer was launched in 1991. The success of the policy should be judged in terms of the extent that appropriate screening of the 'at risk' population is achieved by the screening program and the degree of reduction of differential screening rates between population groups. The relative cost-effectiveness of the various recruitment strategies chosen to meet the policy's objectives should also be evaluated. A necessary prerequisite for evaluation of the policy is the availability of data about the population screened.

Adult↗
PubMed1991

Invasive aspergillosis in AIDS.

Invasive aspergillosis (IA) is a rare infection in patients with the Acquired Immune Deficiency Syndrome (AIDS). We report the first Australian cases of histologically and microbiologically proven IA diagnosed antemortem in AIDS patients. We also describe the first case of laryngeal involvement and the unusual case of a pneumothorax due to IA. These three cases illustrate the varied clinical and pathological features of IA in AIDS and highlight some of the difficulties in diagnosis and treatment. The infections occurred in the setting of advanced immunodeficiency and multiple opportunistic infections and responded poorly to treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Multimeric analysis of von Willebrand factor by molecular sieving electrophoresis in sodium dodecyl sulphate agarose gel.

We report the development and optimisation of an agarose gel electrophoretic method for the separation and detection of von Willebrand Factor (vWF) multimers. The method has been specifically developed for use in the clinical evaluation and classification of patients with von Willebrand's Disease (vWD) and clearly shows structural multimer abnormalities associated with the bleeding diathesis of this inherited bleeding disorder.

Biopolymers↗
PubMedDate not supplied

A cost utility analysis of treatment options for gallstone disease: methodological issues and results.

The techniques of cost utility analysis (CUA) were used to evaluate the treatment of gallstone disease by open and laparoscopic cholecystectomy and by extracorporeal shockwave lithotripsy (ESWL). The application of the techniques in this context raised three methodological questions which are not satisfactorily resolved in the literature. The first is whether an ex ante or ex post perspective is best adopted for the measurement of quality of life (QoL). The second is the method for converting a short term deterioration in QoL followed by full health into QALYs and the reliability of the methods available. The third is the issue of indirect costs which, in the context of a temporary disease state, cannot be easily avoided. The economic evaluation found laparoscopic cholecystectomy to be generally superior than the competitor technologies (entailing lower costs and better outcomes). However, the results were sensitive to assumptions about the perspective for measuring benefits and the inclusion of indirect costs.

Cholecystectomy, Laparoscopic↗
PubMedDate not supplied

Vitamin D deficiency is common and unrecognized among recently arrived adult immigrants from The Horn of Africa.

The prevalence of and risk factors for vitamin D deficiency were examined for recent adult immigrants from East Africa living in Melbourne. Demographic data were collected via a face-to-face questionnaire and risk factors predicting deficiency were examined. Suboptimal levels <25 nmol/L were found in 61 patients (53%; 74% of women; 20% of men). Lower levels were more likely in: (i) patients with a longer duration of residence in Australia, (ii) patients who were mostly covered when outdoors and (iii) women. Routine assessment for vitamin D deficiency should be considered for male and female immigrants from East Africa.

Adolescent↗
PubMedDate not supplied

CD4 lymphocyte numbers after splenectomy in patients infected with the human immunodeficiency virus.

Splenectomy has been reported to alter inconsistently the CD4 lymphocyte numbers in patients infected with the human immunodeficiency virus (HIV). To further assess the effect of splenectomy we have retrospectively examined the charts of 10 patients who were infected with HIV and who had undergone splenectomy. There was a significant increase in the mean CD4 numbers following splenectomy (mean increase of 326/microliters, or 2.1-fold, P = 0.0009), the total lymphocyte numbers (mean increase of 1.55/ml, or 2.2-fold, P = 0.001) and in the CD8 lymphocyte count (mean increase of 968/microliters, or 2.3-fold, P = 0.014). No significant difference was observed in the percentage CD4 lymphocytes (P = 0.95) or in the CD4:CD8 lymphocyte ratio (P = 0.76). In two patients, symptoms suggestive of impaired immune function developed post-splenectomy, at a time when their CD4 lymphocyte numbers were markedly higher than their pre-splenectomy values. One developed oral candidiasis (CD4 960/microliters, percentage CD4 32%), and in one patient a 7 kg weight loss was associated with recurrent mouth ulcers (CD4 680/microliters, percentage CD4 7%). We conclude that the total CD4 count increases significantly after splenectomy while the percentage CD4 lymphocyte count and CD4:CD8 lymphocyte ratio do not. Our data suggest that the CD4 lymphocyte count overestimates the immune function in these patients, although our findings are not conclusive.

CD4-CD8 Ratio↗
PubMedDate not supplied

Dispensing death, desiring death: an exploration of medical roles and patient motivation during the period of legalized euthanasia in Australia.

A qualitative case study was conducted to explore the clinical decision making processes that underpinned the practice of euthanasia under the Rights of the Terminally Ill (ROTI) Act. The key informant for this research was Philip Nitschke, the general practitioner responsible for the legal cases of euthanasia. His information was supported by extensive document analysis based on the public texts created by patients in the form of letters and documentaries. Further collaborating sources were those texts generated by the media, rights groups, politicians, the coroner's cort, and the literature on euthanasia and assisted suicide. A key study finding was that the ROTI legislation did not adequately provide for the specific medical situation in the Northern Territory, Australia. The medical roles, as proscribed by the legislation, carried many inherent assumptions about the health care context and the availability of appropriately qualified medical staff committed to providing euthanasia. These assumptions translated into difficulties in establishing clinical practices for the provision of euthanasia. A further finding concerned the motivations of those who requested euthanasia. This article addresses the medical roles and the motivations of those seeking euthanasia.

Australia↗