Development of WHO guidelines on generalized cost-effectiveness analysis

The growing use of cost-effectiveness analysis (CEA) to evaluate specific interventions is dominated by studies of prospective new interventions compared with current practice. This type of analysis does not explicitly take a sectoral perspective in which the costs and effectiveness of all possible interventions are compared, in order to select the mix that maximizes health for a given set of resource constraints. WHO guidelines on generalized CEA propose the application of CEA to a wide range of interventions to provide general information on the relative costs and health benefits of different interventions in the absence of various highly local decision constraints. This general approach will contribute to judgements on whether interventions are highly cost-effective, highly cost-ineffective, or something in between. Generalized CEAs require the evaluation of a set of interventions with respect to the counterfactual of the null set of the related interventions, i.e. the natural history of disease. Such general perceptions of relative cost-effectiveness, which do not pertain to any specific decision-maker, can be a useful reference point for evaluating the directions for enhancing allocative efficiency in a variety of settings. The proposed framework allows the identification of current allocative inefficiencies as well as opportunities presented by new interventions.

Mycophenolate mofetil therapy for lupus nephritis refractory to intravenous cyclophosphamide

Intravenous (i.v.) cyclophosphamide has been the treatment of choice for diffuse proliferative glomerulonephritis (DPGN) in patients with systemic lupus erythematosus (SLE). However, there is little guidance in the medical literature about what to do when this therapy fails. Mycophenolate mofetil (MMF), a new immunosuppressive agent, has been used successfully in patients with solid organ transplants and rheumatoid arthritis. We report two patients with diffuse proliferative glomerulonephritis who responded favorably to MMF therapy after i.v. cyclophosphamide failed.

Heparin-releasable lipoprotein lipase activity is increased in cardiomyocytes after culture

The activity of lipoprotein lipase (LPL) in adult rat heart cardiomyocytes after overnight culture on laminin-coated plates for 18-22 h was compared with enzyme activity in freshly isolated cardiomyocytes. LPL activity in cellular homogenates from cultured cardiomyocytes and freshly isolated cells was 240 and 233 nmol oleate released h-1.mg-1 protein, respectively. LPL specific activity (mU/ng LPL protein) was 0.07 in cultured cells compared with 0.42 in freshly isolated cells, indicating an increased content of inactive LPL mass after overnight culture. The heparin-induced release of LPL activity into the medium of cultured cardiomyocytes (198 nmol.h-1.mg-1) was much greater than heparin-releasable LPL (HR-LPL) activity (59 nmol.h-1.mg-1) from freshly isolated cells. HR-LPL activity from cultured cardiomyocytes was dependent on serum (16.3-fold activation) and was inhibited by high ionic strength (1 M NaCl) and by a polyclonal antibody to LPL. Cultured cardiomyocytes also had more immunodetectable LPL on the cell surface compared with freshly isolated cardiomyocytes, consistent with increased HR-LPL activity. Therefore, overnight culture may permit cardiomyocytes time to recover from the stress of isolation by increasing the content of LPL on the cell surface.

Fatty acids reduce heparin-releasable LPL activity in cultured cardiomyocytes from rat heart

Varying glucose and fatty acid (FA) concentrations in the medium of cultured cardiomyocytes from adult rat hearts were tested for effects on lipoprotein lipase (LPL) activity. Glucose (5.5, 11, and 25 mM in the culture medium for 18-22 h) had no effect on either heparin-releasable LPL (HR-LPL) or on cellular LPL (C-LPL) activities. When cardiomyocytes were cultured overnight with 60 microM oleate, HR-LPL activity was reduced to 20% of control, with no change in C-LPL activity or total C-LPL mass. Similar results (HR-LPL and C-LPL activities) were obtained with 60 microM concentrations of palmitate and myristate; linoleate and eicosapentaenoate did reduce C-LPL activity, but the decrease in HR-LPL activity was much greater. Oxfenicine, an FA oxidation inhibitor, did not alter the inhibitory effect of 60 microM oleate on HR-LPL. Short-term incubations (1 and 3 h) of cultured cardiomyocytes with 60 microM oleate did not displace LPL into the medium. Immunodetectable LPL on the cell surface of oleate-treated cultured cardiomyocytes was increased compared with control cells, but heparin treatment released the same amount of LPL mass that had reduced catalytic activity.

A methodology for specifying PET VOI's using multimodality techniques

Volume-of-interest (VOI) extraction for radionuclide and anatomical measurements requires correct identification and delineation of the anatomical feature being studied. We have developed a toolset for specifying three-dimensional (3-D) VOI's on a multislice positron emission tomography (PET) dataset. The software is particularly suited for specifying cerebral cortex VOI's which represent a particular gyrus or deep brain structure. A registered 3-D magnetic resonance image (MRI) dataset is used to provide high-resolution anatomical information, both as oblique two-dimensional (2-D) sections and as volume renderings of a segmented cortical surface. VOI's are specified indirectly in two dimensions by drawing a stack of 2-D regions on the MRI data. The regions are tiled together to form closed triangular mesh surface models, which are subsequently transformed into the observation space of the PET scanner. Quantification by this method allows calculation of radionuclide activity in the VOI's, as well as their statistical uncertainties and correlations. The methodology for this type of analysis and validation results are presented.

Development of PMA guidance for ventricular assist devices and total artificial heart

The US Food and Drug Administration's (FDA's) involvement in the investigation of devices since 1980 is discussed. The development of draft guidelines for a premarket approval application (PMA) is described. The availability of the document is announced and comments are solicited.

Thermogravimetric analysis of composite restorative resins

Thermogravimetric analyses of six commercial brands of composite restorative resins were performed at temperatures from 25 to 700 C in air with a heating rate of 9.5 Cl minute. The reported ashed weight was assumed to be the filler weight. The thermogravimetric technique as applied to these composite resins was effective in deriving basic information about polymer systems.

Unusual Cause of Unilateral Epistaxis: Nasal Leech Infestation

Common causes for unilateral nasal bleeding in adults are benign or malignant tumors and deviatednasal septum. Here we present two cases of recurrent unilateral nasal bleeding due to leech infestation.Though it is not a common cause for nasal bleeding, a clinician should suspect leech infestation for arecurrent nasal bleeding specially in tropical countries like Nepal.Key words: leech infestation, nasal bleeding, unilateral