Functional hepatic imaging as a biomarker of primary and secondary tumor response to loco-regional therapies.

Objective criteria to measure tumor response are a key tenet for assessment of treatment efficacy when evaluating a therapeutic modality. Several response criteria have been proposed including the Response Evaluation Criteria in Solid Tumors (RECIST), modified RECIST (mRECIST), RECIST 1-1, and European Association for the Study of the Liver (EASL) guidelines. Response following loco-regional therapies (LRT) can be particularly difficult to assess as post-treatment changes may not always relate to changes in lesion size. As imaging modalities and solid tumor therapies continue to advance, there has been growing recognition that measurement of actual tumoricidal activity may not always be related to tumor size, and accurate assessment of treatment response may vary by therapeutic modality. As such, the objective change in the physical size characteristics of a tumor may not accurately reflect biological response to treatment. Functional imaging encompasses methods that are capable of detecting or measuring changes in tissue metabolism, blood flow, or composition. Conventional imaging modalities such as magnetic resonance imaging (MRI) and computed topography (CT) now include techniques such as diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, dynamic contrast enhancement (DCE-MRI), and perfusion CT (pCT). Use of functional cross-sectional imaging is particularly relevant to assess primary and secondary hepatic malignancies treated with LRT, such as trans-arterial chemoembolization (TACE), radiofrequency ablation (RFA), yttrium-90 (Y-90), and hepatic arterial infusion (HAI) chemotherapy. We herein review the imaging techniques, as well as the methodologies for measuring tumor response and survival, among patients treated with LRT for primary and secondary hepatic malignancies.

Review of a group for parents of anorexics.

A two year experience in running a group for parents of children with anorexia nervosa is described. It would appear that a parents' group is of positive, though limited, value in helping parents to adjust to their child's illness and it may be a useful adjunct in the overall treatment of anorexia nervosa.

Who makes decisions about new technology in hospitals?

Three top managers from different kinds of hospitals explain how decisions to buy expensive new technology are made in their institutions. Financial feasibility, competition with other hospitals, and the advantages of new equipment to patients and members of the medical staff are all considerations administrators must keep in mind when buying new equipment.

Planning for "the technology factor".

Modern medical care technology impacts on decision making in the industry as never before. Whether this impact is more positive than negative is debatable; but the dialogue is of vital interest to hospitals, as technology is the central issue in the current furor over cost control.

Nurse practitioners in prevention and health education.

The Where? How? Who will pay? and Who will provide? of preventive medicine and health education can be answered. And a promising answer is the family nurse practitioner, who may be able to handle 60 to 80 percent of routine tasks normally done by physicians and to provide health education as a part of routine care.

Fatty acid toxicity and methyl ketone production in Aspergillus niger.

Vegetative hyphae of Aspergillus niger rapidly converted caproic acid into 2-pentanone. More caproic acid was required for maximal ketone production at alkaline as compared to acidic pH values. Further increases in caproate concentrations at each pH value tested (4.5, 5.5, 6.5, 7.5, and 8.5) resulted in inhibition of ketone production and O(2) uptake. At alkaline pH values (8.5 and 7.5), oxygen uptake above the endogenous level and the production of 2-pentanone were parallel. This relationship did not hold at acidic pH values. At these pH values, ketone production continued (pH 6.5) or attained a maximum (pH 5.5 and 4.5) at caproate concentrations at which oxygen uptake was inhibited below endogenous levels. These data indicate that endogenous oxygen uptake was not inhibited by caproate at alkaline pH values at concentrations which did inhibit caproate oxidation and 2-pentanone production. Conversely, at acidic pH values, endogenous oxygen uptake was vigorously inhibited by caproate at concentrations at which exogenous fatty acid oxidation and 2-pentanone production were less affected. Simon-Beevers plots of these data showed that the undissociated acid was the permeant form of caproic acid. The fatty anion appeared to be the active or inhibitory form of caproate within the cell. Vegetative hyphae of A. niger were poorly buffered. Once the hyphae were washed and resuspended in phosphate buffer, they were well buffered towards inhibitory concentrations of caproic acid. These findings suggest that the primary mechanism(s) by which caproate inhibits oxygen uptake and ketone formation does not involve a change in the intracellular pH.

The effects of continuous and discontinuous walking on physiologic response in college-age subjects.

The Surgeon General's Report on Physical Activity recommends an accumulation of 30 minutes of moderate physical activity on most, if not all, days of the week. The purpose of this study was to determine if 3 10-minute bouts of walking had the same effect on physiologic response as 1 30-minute bout of continuous walking when both were performed 3 d x wk(-1) for 12 weeks. Thirty (18 completed the study) college-aged subjects (VO2max: 44 ml x kg(-1) x min(-1) +/- 8.37) were randomly assigned to either a nonexercising group (N = 7), a group (N = 5) that performed 3 10-minute bouts, or a group (N = 6) that performed 1 30-minute bout of exercise. Intensity was set at 50-60% of estimated maximum heart rate. A mixed factor 2 x 3 analysis of variance (time by group) was used to analyze the data (alpha = 0.10). Controls demonstrated a significant decrease in VO2max, while the exercise groups demonstrated no significant change. There was no significant difference demonstrated for pre- and postmaximal heart rates or for pre- and postmaximal respiratory exchange ratio. Continuous and discontinuous walking were equally effective in maintaining, but not improving, VO2max.