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Biomedical subjects

C Bennett

Publications and source records attributed to C Bennett.

At least 37 records · Page 2Linked to original sources
PubMed1999

Costs of care associated with high-dose therapy and autologous transplantation for non-Hodgkin's lymphoma: results from the University of Nebraska Medical Center 1989 to 1995.

The purpose of this paper was to (1) comprehensively analyze transplant-related costs for predicted temporal cost shifting and (2) to evaluate whether previous findings of decreasing costs of care persisted using a cost analysis of 353 NHL patients who received autologous stem cell transplantation (SCT) at the University of Nebraska Medical Center. All transplant-related costs between the patient's initial consult and program dismissal were obtained and inflated to constant 1995 dollars. Homogeneous resources were categorized into six cost-drivers and subdivided into outpatient, transplant, and additional inpatient time periods in order to evaluate resource utilization and cost shifting patterns. Between 1989 and 1991 both the average length of stay and comprehensive costs decreased 4.9 days and 14%, respectively. By 1995 additional decreases of 25.7 days and 51% led to an overall 7 year cost decline of 65%. Percent contributions of the six cost-drivers remained similar demonstrating uniformed suppression in transplant-related resource consumption. In contrast, the timing of resource utilization changed dramatically, with transplant hospitalization costs accounting for 83% of the overall costs in 1989, 71% by 1992, and only 45% in 1995, while total outpatient's contribution was 14%, 26% and 49%. Before 1991 ebbing costs were likely related to the development of new technologies such as hematopoietic growth factors and peripheral SCT, while the three-fold larger improvement in costs reported by 1995 are presumably associated with learning curve effects such as organizational changes, increased use of coordinated outpatient facilities, and the more cost-effective use of laboratory tests and pharmaceuticals.

Adolescent↗
PubMed1999

Cost-effectiveness analysis of pegylated-liposomal doxorubicin and liposomal daunorubicin treatments in patients with Kaposi's sarcoma.

Economic evaluations of new AIDS treatment drugs are important. For physicians treating patients with Kaposi's sarcoma, these issues are especially meaningful since cancer treatment costs for this group of patients are high. Kaposi's sarcoma is the most frequently occurring neoplasm in AIDS patients, affecting about 15% of this population. In our study, a retrospective economic evaluation has been made based on data from two randomized phase III clinical studies of severely immune-compromised HIV-infected individuals and which compares liposomal doxorubicin with liposomal daunorubicin. We have estimated the cost and cost effectiveness of the two drugs. The costs per complete or partial response are USS 18340 for daunorubicin and USS 8871 for doxorubicin. The incremental cost per additional responder by using liposomal doxorubicin instead of liposomal daunorubicin is USS 1910. Sensitivity analysis shows that these results hold over a wide range of assumptions.

Antibiotics, Antineoplastic↗
PubMed1999

Sphincteric stent versus external sphincterotomy in spinal cord injured men: prospective randomized multicenter trial.

PURPOSE: In a prospective randomized multicenter trial we compared the treatment results of conventional external sphincterotomy with those of UroLume sphincteric stent prosthesis placement in men with spinal cord injury and external detrusor-sphincter dyssynergia. MATERIALS AND METHODS: We randomized 57 men with spinal cord injury in whom urodynamics verified external detrusor-sphincter dyssynergia into 2 groups to undergo either sphincter defeating procedure. We compared the primary urodynamic parameter of maximum detrusor pressure, and secondary urodynamic parameters of bladder capacity and post-void residual urine volume in men who underwent sphincterotomy or sphincteric stent placement. Parameters were measured preoperatively, and 3, 6, 12 and 24 months postoperatively. Patients completed questionnaires regarding voiding sensation and quality of life issues at each followup visit. RESULTS: Demographic data of the 26 patients treated with sphincterotomy and the 31 treated with sphincteric stent placement were statistically similar. Preoperatively mean maximum detrusor pressure plus or minus standard deviation in sphincterotomy and stent cases was 98.3 +/- 27.6 and 95.7 +/- 27.7 cm. water, respectively (p = 0.73). At 12 months mean maximum detrusor pressure decreased to 48.9 +/- 16.4 and 52.6 +/- 31.6 cm. water in the sphincterotomy and stent groups, respectively (p = 0). Preoperatively mean bladder capacity in sphincterotomy and stent cases was 245 +/- 158 and 251 +/- 145 ml., respectively (p = 0.87). Bladder capacity did not change significantly in either treatment group throughout followup. Preoperatively mean post-void residual urine volume in the sphincterotomy and stent groups was 212 +/- 163 and 168 +/- 114 ml., respectively (p = 0.33). Residual urine volume decreased in each group at some but not all followup evaluations. The duration of hospitalization was greater for sphincterotomy than stenting (p = 0.036). Six stents required explantation. CONCLUSIONS: The UroLume stent is as effective as conventional external sphincterotomy for treating external detrusor-sphincter dyssynergia. However, sphincteric stent placement is advantageous because it involves shorter hospitalization and is potentially reversible.

Adult↗
PubMed1999

Relative effectiveness and cost-effectiveness of methods of androgen suppression in the treatment of advanced prostate cancer.

OBJECTIVES: With 184,500 new cases and 39,200 deaths anticipated in 1998, prostate cancer is second only to lung cancer in cancer mortality for men. This report is a systematic review of the evidence from randomized controlled trials on the relative effectiveness of alternative strategies for androgen suppression as treatment of advanced prostate cancer. Three key issues are addressed: (1) the relative effectiveness of the available methods for monotherapy (orchiectomy, luteinizing hormone-releasing hormone [LHRH] agonists, and antiandrogens), (2) the effectiveness of combined androgen blockade compared to monotherapy, and (3) the effectiveness of immediate androgen suppression compared to androgen suppression deferred until clinical progression. Outcomes of interest are overall, cancer-specific, and progression-free survival; time to treatment failure; adverse effects; and quality of life. Two supplementary analyses were conducted for each key question: (1) meta-analysis of overall survival at 2 years (questions 1 and 2) and 5 years (questions 2 and 3), and (2) cost-effectiveness analysis. SEARCH STRATEGY: The MEDLINE, CANCERLIT, and EMBASE databases were searched from 1966 to March 1998, and Current Contents to August 24, 1998, for the terms: leuprolide (Lupron); goserelin (Zoladex); buserelin (Suprefact); flutamide (Eulexin); nilutamide (Anandron, Nilandron); bicalutamide (Casodex); cyproterone acetate (Androcur); diethylstilbestrol (DES); and orchiectomy (castration, orchidectomy). The search was then limited to human studies indexed under the MeSH term "prostatic neoplasms" and by the UK Cochrane Center search strategy for randomized controlled trials. Total yield was 1,477 references. SELECTION CRITERIA: We Reports of efficacy outcomes were limited to randomized controlled trials. Phase II studies that reported on withdrawals from therapy and all studies reporting on quality of life were also included. DATA COLLECTION AND ANALYSIS: The systematic review used a prospectively designed protocol conducted by two independent reviewers, with disagreements resolved by consensus. The meta-analysis combined data on overall survival using a random effects model. The cost-effectiveness analysis used a decision analysis model of advanced prostate cancer with health states and transitions derived from the literature and estimates of effectiveness derived from the meta-analysis. The cost-effectiveness analysis is conducted from a societal perspective, consistent with the guidelines of the U.S. Public Health Service Panel on Cost-Effectiveness in Health and Medicine. MAIN RESULTS: Survival after treatment with an LHRH agonist is equivalent to survival after orchiectomy. The available LHRH agonists are equally effective, and no LHRH agonist is superior to the other when adverse effects are considered. Survival may be somewhat lower with use of a nonsteroidal antiandrogen. There is no statistically significant difference in survival at 2 years between patients treated with combined androgen blockade or monotherapy. Meta-analysis of the limited data available shows a statistically significant difference in survival at 5 years that favors combined androgen blockade. However, the magnitude of this difference is of questionable clinical significance. For the subgroup of patients with good prognosis, there is no statistically significant difference in survival. Adverse effects leading to withdrawal from therapy occurred more often with combined androgen blockade. No evidence is yet available from randomized controlled trials of androgen suppression initiated at prostate-specific antigen (PSA) rise after definitive therapy for clinically localized disease. For patients who are newly diagnosed with locally advanced or asymptomatic metastatic disease, the evidence is insufficient to determine whether primary androgen suppression initiated at diagnosis improves outcomes. (ABSTRACT TRUNCATED)

Androgen Antagonists↗
PubMed1998

Heparinase III limits rat arterial smooth muscle cell proliferation in vitro and in vivo.

Heparinase III degrades heparan sulfate proteoglycans, which are co-receptors for growth factors that stimulate arterial proliferation. We assessed the ability of locally-delivered heparinase III to limit medial vascular smooth muscle cell proliferation induced by balloon catheter injury in rat carotid arteries. Whereas vehicle-treated arteries showed 12% of smooth muscle cells proliferating after 2 days, heparinase III (0.022-5.7 mg/kg) treated arteries showed 0.8-4%. Chemically-inactivated heparinase III did not limit proliferation. In isolated rat A10 vascular smooth muscle cells, heparinase III (1 IU/ml) inhibited both PDGF-BB and bFGF mediated increases in proliferation and migration. These results suggest that heparinase III can limit proliferation by affecting heparan sulfate proteoglycan binding growth factors following arterial injury.

Animals↗
PubMed1998

Physical, chemical, and histologic changes in dentin caries lesions of primary teeth induced by regular use of polyol chewing gums.

A previous clinical trial showed that long-term use of saliva-stimulating polyol (xylitol and sorbitol) chewing gums was associated with arrest of dental caries in young subjects. After a 20-22-month intervention (when the subjects were 8 years old), a total of 23 primary teeth with extensive dentin caries lesions whose surface in clinical examination was found to be totally rehardened (remineralized) could be removed because the teeth were near their physiologic exfoliation time. These teeth were subjected to histologic, microhardness, and electron microscopic tests. The majority of the specimens had been remineralized from the surface by a non-cellular-mediated process within the remaining collapsed, organic extracellular matrix associated with the remaining dentinal surface. Many of the underlying dentinal tubules were filled with a matrix that had been subsequently mineralized. Dental microanalyses showed that the topmost (outer) 20-microm-thick rehardened layer of the lesions exhibited the highest Ca:P ratio, which leveled off at a depth of approximately 150 microm. The rehardened surface layer (normally <0.1 mm in thickness) was significantly (P < 0.001) harder than sound dentin and nearly as hard as sound enamel. Although the main source of the mineral present in the rehardened layer was most likely of salivary origin, some extracellular remineralization was probably mediated by odontoblasts. The results complete the dinical diagnoses of the original trial and suggest that regular use of polyol chewing gums may induce changes in dentin caries lesions, which in histologic and physiochemical studies show typical characteristics of rehardening and mineralization.

Calcium↗
PubMed1998

Evidence for a common mutation in hereditary pancreatitis.

Hereditary pancreatitis is an autosomal dominant disorder with incomplete penetrance. It is characterised by recurring episodes of severe abdominal pain and often presents in childhood. Recently, a mutation in the cationic trypsinogen gene was identified in this disease. Previously, only one mutation at residue 117 of the trypsinogen gene has been found in the five separate hereditary pancreatitis families, four from the USA and one from Italy. Alteration of the Arg117 site is believed to disrupt a fail-safe mechanism for the inactivation of trypsin, leading to autodigestion of the pancreas under certain conditions. Molecular analysis of the trypsinogen gene was carried out on a hereditary pancreatitis family from the UK. The same G to A mutation at residue 117 was identified in this family, suggesting that this is a common mutation in hereditary pancreatitis.

Chronic Disease↗
PubMed1997

HIV and AIDS awareness: an evaluation of a short training programme for midwives.

In response to a Department of Health, England, circular encouraging policies of named voluntary antenatal HIV antibody testing, one West Midlands health authority in England introduced a policy of raising the issue proactively at the first antenatal attendance. In order to facilitate this policy a short staff education programme was provided for midwives. This paper reports on part of a study which aimed to evaluate the impact of the HIV awareness training programme. A sample of midwives (n = 65) was randomly selected for inclusion in the study. Thirty-three had attended training and 32 had not. Data were collected using a self-administered questionnaire exploring knowledge of aetiology of HIV/AIDS, knowledge of transmission, knowledge of obstetric and paediatric HIV, attitudes to HIV, issues related to antenatal HIV antibody testing and opinions about the HIV awareness training programme. Results indicated no significant difference in levels of knowledge or in attitude between those who had attended the training programme and those who had not. Similarly, no significant difference was found in terms of how midwives would react to women requesting HIV antibody testing. Many of the results contradict the current literature and as a conclusion it is suggested that there is a need to review HIV-related training for midwives.

AIDS Serodiagnosis↗
PubMed1997

An international study of the exposure of children to traffic.

OBJECTIVES: To examine the extent of international differences in children's exposure to traffic as pedestrians or bicyclists. DESIGN: Children's travel patterns were surveyed using a parent-child administered questionnaire. Children were sampled via primary schools, using a probability cluster sampling design. SETTING: Six cities in five countries: Melbourne and Perth (Australia), Montreal (Canada), Auckland (New Zealand), Umeå (Sweden), and Baltimore (USA). SUBJECTS: Children aged 6 and 9 years. MAIN OUTCOME MEASURES: Modes of travel on the school-home journey, total daily time spent walking, and the average daily number of roads crossed. MAIN FINDINGS: Responses were obtained from the parents of 13423 children. There are distinct patterns of children's travel in the six cities studied. Children's travel in the three Australasian cities, Melbourne, Perth and Auckland, is characterised by high car use, low levels of bicycling, and a steep decline in walking with increasing car ownership. In these cities, over a third of the children sampled spent less than five minutes walking per day. In Montreal, walking and public transport were the most common modes of travel. In Umeå, walking and bicycling predominated, with very low use of motorised transport. In comparison with children in the Australasian and North American cities, children in Umeå spend more time walking, with 87% of children walking for more than five minutes per day. CONCLUSIONS: There are large international differences in the extent to which children walk and cycle. These findings would suggest that differences in 'exposure to risk' may be an important contributor to international differences in pedestrian injury rates. There are also substantial differences in pedestrian exposure to risk by levels of car ownership-differences that may explain socioeconomic differentials in pedestrian injury rates.

Australia↗
PubMed1997

Visual coping scenarios to facilitate discussion of coping responses with impoverished women at risk for AIDS.

1. Impoverished and homeless women are prone to coping with life stresses through drug and alcohol use. 2. Visual coping scenarios are culturally sensitive strategies to help impoverished minority women discuss effective coping responses. 3. A visual coping scenario redirects attention from a negative emotional event to an effective problem-focused coping strategy.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Entrance qualifications and student performance in a hybrid problem based and traditional medical programme.

A hybrid problem based learning (PBL) and traditional medical programme was started at the Trinidad campus of the University of the West Indies in 1989. Analyses were carried out to determine the extent to which the entrance qualifications of the students were related to their performances at the examinations in the Phase I (preclinical and paraclinical) and Phase II (clinical) programmes. Students who were admitted on the basis of their results in the secondary school General Certificate of Examination (GCE), 'A' level scored higher at the Phase I, but not at the Phase II, level than those who already had university education. Among the 'A' level students, there was positive correlation between the total 'A' level scores and the examination marks in the medical programme, particularly at the Phase I level. Furthermore, multiple regression analyses indicated that the grades in 'A' level Chemistry and, to a lesser extent in Biology, had the most influence on performances at the Phase I examinations, with much less influence on performances at the Phase II examinations. These results suggest that good grades at 'A' level examinations are significant factors, but not the only important ones, that favour high achievement in the initial stages of this type of PBL/traditional medical programme.

Education, Medical, Undergraduate↗
PubMed1996

Conclusion and review of the Michigan Xylitol Programme (1986-1995) for the prevention of dental caries.

The major results of the Michigan Xylitol Programme (1986-1995) are summarised. The Programme consisted of several clinical trials and laboratory investigations designed to study the usage of xylitol-containing saliva stimulants in the prevention of dental caries. The trials patients included young (initially 6 year olds) and adult or geriatric subjects who were given saliva stimulants (mostly chewing gum) for periods of two weeks to 56 months. A special rationale behind these studies was the need to further test the validity of the 'pentitol-hexitol theory' in the prevention of caries. This theory has maintained that pentitols (sugar alcohols with five hydroxyl groups, such as xylitol) may be cariologically more effective than hexitols (sugar alcohols with six hydroxyl groups, such as sorbitol). The accumulated clinical, sialochemical and microbiologic evidence suggests that xylitol, a natural carbohydrate sweetener of the pentitol type, is more effective in preventing dental caries than sorbitol, and cariologically safer than sorbitol, a natural carbohydrate of the hexitol type. Sorbitol was found to be significantly less cariogenic than sucrose. The Programme's results shed additional light on the cariologic and oral biologic effects of natural, dietary polyols, and suggest that the usage of xylitol chewing gum (and in some cases xylitol dragées) can be considered a valuable additional tool in caries prevention and in stabilisation of caries in all age groups.

Adolescent↗
PubMed1995

Evidence that the APOE locus influences rate of disease progression in late onset familial Alzheimer's Disease but is not causative.

An association has been observed in several independent data sets between late onset Alzheimer's Disease (AD) and the APOE locus on chromosome 19. We have examined the genotype in family history positive (FHP) and family history negative (FHN) cases and find a distortion of the APOE allele frequencies in accord with previous studies. However, when we examined the allele distribution of the at-risk siblings of the FHP group we found an excess of the epsilon 4 allele which also differs significantly from historic controls but not from the affected siblings. The age distribution of the affected and unaffected siblings was similar, suggesting that the allelic frequency distortion in the unaffected siblings was not due to their being below the mean age of onset. Lod score linkage analysis, with age dependent onset and non-stringent specification of the genetic parameters, did not suggest linkage to the APOE locus. Furthermore, an analysis of variance of the age of disease free survival suggested that APOE genotype contributes a small fraction of the total variance indicating that the APOE locus is a poor predictor of disease free survival age within late onset families. One explanation for the age dependent association reported by other groups, and our results, is that the APOE locus enhances the rate of progression of the disease process in otherwise predisposed individuals and that variation at this locus is not able in and of itself to cause the disease. We suggest this hypothesis is compatible with the current literature regarding APOE and AD.

Age Factors↗