Accuracy of dual-energy radiographic absorptiometry of the lumbar spine: cadaver study

Dual-energy radiographic absorptiometry (DRA) was used to measure the bone mineral content and area density of lumbar vertebrae (L2-L3) in 11 cadavers. These data were subsequently compared with measured ash content and density. Excellent correlation was obtained between bone mineral content measured with DRA and ash weight (r = .963, P less than .0001). The accuracy error in determining mineral content in lumbar vertebrae with DRA was about 9%. In addition, strong correlation was observed between bone mineral density measured with DRA and ash density (r = .881, P less than .0001).     

Minority female dentists: a synopsis

This pilot study identified a group of minority female dentists who are relatively young to the dental profession. In general, these individuals are enthusiastic about a career in dentistry. Career contentment is evinced by the reported level of satisfaction with the dental profession, irrespective of educational indebtedness or annual income. Of those who are dissatisfied, it seems as if income and debt are not the primary areas of concern. These findings provide an impetus for a more comprehensive investigation of this emerging population of dentists.     

Melanoma tumor vaccine: five-year follow-up

For many years, various melanoma vaccines have been employed. This is a unique melanoma vaccine in that it is a subcellular tumor homogenate and no adjuvants have been added. This vaccine has been given to 129 stage I and 61 stage II melanoma patients. All were followed at least 5 years and had 87.5% and 63.9% 5-year survival rates, respectively. Sixty-four stage I males and 65 stage I females had 84% and 90% 5-year survival rates, respectively. We saw no difference between those with or without lymph node dissection. Thirty-six stage II males and 25 stage II females had 66.7% and 60% 5-year survival rates, respectively. Of stage II patients, 23 had only one positive node, 22 had two to four positive nodes, and 9 had five or more positive nodes with 69%, 63%, and 55% 5-year survival rates, respectively. Large published series were used as historical controls [6,27,28], and significant differences were noted when compared to our stage II patients (P = 0.001)--those with two to four positive nodes (P = 0.03), and those with five or more positive nodes (P = 0.04). We conclude that there is a significant increase in survival for these stage II patients, at high risk of recurrence, receiving a tumor homogenate vaccine. This vaccine warrants further analysis, development, and use in a phase III randomized clinical trial.     

Ultrastructure of cholinergic synaptic terminals in the thalamic anteroventral,ventroposterior, and dorsal lateral geniculate nuclei of the rat

The principal relay nuclei of the thalamus receive their cholinergic innervation from two midbrain cholinergic groups: the pedunculopontine tegmental nucleus and the laterodorsal tegmental nucleus. The different thalamic nuclei exhibit populations of cholinergic axons which vary in density and morphology when examined at the light microscopic level. However, the ultrastructure of the cholinergic terminals in different thalamic nuclei has not been described. This study was undertaken to confirm that synaptic contacts are formed by cholinergic axons in several principal thalamic relay nuclei, to describe their ultrastructural morphology, and to identify the types of postsynaptic elements contacted by cholinergic synaptic terminals. The thalamic nuclei examined in this study are the dorsal lateral geniculate nucleus, ventroposteromedial nucleus, ventroposterolateral nucleus, and anteroventral nucleus. Our results confirm that cholinergic axons form synaptic terminals in these thalamic nuclei. Cholinergic synaptic terminals contact structures outside the characteristic synaptic glomeruli, are never postsynaptic, and have morphologies and postsynaptic targets which differ among the thalamic nuclei. In the ventroposterior nuclei, cholinergic terminals form asymmetric synaptic contacts onto larger dendrites in the extraglomerular neuropil. In the anteroventral nucleus, cholinergic terminals form both symmetric and asymmetric synaptic contacts onto dendrites and somata. Cholinergic terminals in the anteroventral nucleus are larger than those in other nuclei. In the dorsal lateral geniculate nucleus, cholinergic terminals contact both somata and dendrites in the extraglomerular neuropil, but the synaptic contacts in this nucleus are symmetric in morphology.     

Technical developments for cerebral thermal treatment: water-cooled diffusing laser fibre tips and temperature-sensitive MRI using intersecting image planes.

The aim was to determine if water-cooled diffusing tips could produce larger and safer (better controlled) thermal lesions than non-cooled diffusing tips at 980 nm. Thermal lesions were induced in beef myocardium in vitro with and without water cooling using a 980 nm diode laser at various power levels. Seven intracerebral treatments were performed in six canines using water-cooled diffusing tips with four animals having intracerebral transmissible venereal tumours grown from inoculate. Magnetic resonance thermal imaging (MRTI)-based feedback software using a fast, radio frequency-spoiled gradient echo acquisition with two intersecting image planes was used for on-line monitoring and control of treatment and for the evaluation of in vivo laser lesion production. In cases where two-plane MRTI was employed, the maximum calculated temperature was compared in each plane. Using water-cooled tips and 400 micro m core diameter laser diffusing fibres in in vitro beef myocardium, power of up to 9.5 W was applied for 8 min without tip failure. Without cooling, tip failure occurred in under 4 min at 6 W, in under 2 min at 7 W and instantaneously at 8 W. Additionally, char accompanied lesions made with uncooled tips while cooled application resulted in only minimal char at only the highest thermal dose. Achieved lesion cross-sectional diameters in in vitro samples were up to 26.5 x 23.3 mm when water cooling was used. In canine brain and transmissible venereal tumours, up to 18.1 x 21.4 mm lesions were achieved. It is concluded that water cooling allows safe application of higher power to small core diameter diffusing tip fibres, which results in larger thermal lesions than can be achieved without cooling. Two-plane MRTI enhances on-line monitoring and feedback of thermal treatment.     

Anemia during adjuvant non-taxane chemotherapy for early breast cancer: Incidence and risk factors from two trials of the International Breast Cancer Study Group

Goal of the work Anemia is a common side effect of chemotherapy. Limited information exists about its incidence and risk factors. The objective of this study was to evaluate the incidence of anemia and risk factors for anemia occurrence in patients with early breast cancer who received adjuvant chemotherapy. Materials and methods We evaluated risk factors for anemia in pre- and post/perimenopausal patients with lymph node-positive early breast cancer treated with adjuvant chemotherapy in two randomized trials. All patients received four cycles of doxorubicin and cyclophosphamide (AC) followed by three cycles of cyclophosphamide, methotrexate, fluorouracil (CMF). Anemia incidence was related to baseline risk factors. Multivariable analysis used logistic and Cox regression. Main results Among the 2,215 available patients, anemia was recorded in 11% during adjuvant chemotherapy. Grade 2 and 3 anemia occurred in 4 and 1% of patients, respectively. Pretreatment hemoglobin and white blood cells (WBC) were significant predictors of anemia. Adjusted odds ratios (logistic regression) comparing highest versus lowest quartiles were 0.18 (P < 0.0001) for hemoglobin and 0.52 (P = 0.0045) for WBC. Age, surgery type, platelets, body mass index, and length of time from surgery to chemotherapy were not significant predictors. Cox regression results looking at time to anemia were similar. Conclusions Moderate or severe anemia is rare among patients treated with AC followed by CMF. Low baseline hemoglobin and WBC are associated with a higher risk of anemia. The authors represent the International Breast Cancer Study Group.     

The variable influence of an alpha component in pregnancy plasma on four different assay systems for the measurement of pregnancy-specific beta1 glycoprotein

Four methods (radioimmunoassay, electroimmunoassay, laser nephelometry and kinetic immunoturbidimetry) have been evaluated for the measurement of proteins with pregnancy-specific beta1 glycoprotein immunoreactivity. The influence of two maternal plasma proteins with different electrophoretic mobilities (alpha2 and beta1) but with similar antigenic determinants has been assessed in each assay system. The radioimmunoassay method, which utilises a homogeneous preparation of pregnancy-specific beta1 glycoprotein for the preparation of iodinated tracer, and the kinetic immunoturbidimetric assay which measures antigen-antibody complex formation over the first minute of the reaction, were both considerably more specific for the beta1 component of pregnancy specific beta1 glycoprotein immunoreactivity than the laser nephelometric or electroimmunoassay methods.     

The Total Health Care Audit System: a systematic methodology for clinical practice evaluation and development in NHS provider organizations

Writing in Medical Education in 1982, Fowkes (1982) noted the lack of general agreement within the medical profession on methods of audit, a deficiency previously articulated by Shaw (1980) and later emphasized by McIntyre (1985). More recently, a study by Black & Thompson (1993) of consultant and junior medical staff in four London district general hospitals revealed that 'many doctors did not understand how to undertake audit', and major research by both Hopkins (1993, 1994) and Buttery et al. (1994) described a multiplicity of methodological deficiencies in the general approaches to audit adopted by clinicians since the promulgation of the White Paper definition in 1989. Soundness of methodological approach is fundamental to securing the success of clinical audit within Provider organizations and is thus central to the generation of measurable improvements in the quality of clinical care being delivered to patients. It is therefore disturbing that methodological deficiencies may still be observed in general approaches to audit (Buttery et al. 1994), with no author yet recommending a formal system for critical inquiry into clinical practice. It was the recognition of the unsatisfactory nature of this situation which led us to develop a system aimed at assessing, in a critical fashion, the quality of the totality of care dispensed within NHS provider organizations. The system is presented here for the first time.     

Plasma coenzyme Q(10) in children and adolescents undergoing doxorubicin therapy

The objective of this study was to test the hypothesis that doxorubicin treatment for cancer in childhood and adolescence causes a dose-related decrease in the concentration of plasma coenzyme Q(10). The concentration of plasma coenzyme Q(10) was measured before and after administration of doxorubicin in six patients, and before and after chemotherapy in six patients undergoing treatments that did not include doxorubicin. There was a significant increase in the concentration of plasma coenzyme Q(10) in post-treatment samples compared to pre-treatment samples in patients treated with doxorubicin (P=0.008; n=32), whereas there were no significant changes in plasma coenzyme Q(10) concentrations in patients treated with chemotherapy that did not include doxorubicin. (P=0.770; n=30). We hypothesise that the increase in plasma coenzyme Q(10) that was observed in patients undergoing doxorubicin treatment is due to release of coenzyme Q(10) from apoptotic or necrotic cardiac tissue. We conclude that the cardiotoxicity due to doxorubicin therapy does not involve acute myocardial depletion of coenzyme Q(10).