Recombinant rat surfactant-associated protein D inhibits human T lymphocyte proliferation and IL-2 production

Components of the airspace-lining material may contribute to the local regulation of immune function within the lung. We report here that recombinant rat pulmonary surfactant-associated protein D (SP-D) inhibits the lectin- and anti-CD3-stimulated proliferation of human PBMCs. Inhibition was associated with a decreased production of IL-2, and the addition of human rIL-2 blocked the inhibitory action of SP-D. These effects were not inhibited by maltose, indicating that the inhibitory activity was not dependent upon the lectin activity of SP-D. Studies employing mutant SP-D lacking N-linked sugars or defective in multimerization further indicated that inhibition was not dependent upon cellular interactions with the N-linked oligosaccharide on SP-D or the oligomerization of trimeric SP-D subunits. Although a peptide containing an inverted DGR showed similar IL-2-dependent effects on anti-CD3-stimulated proliferation, deletion of the conserved DGRDGR sequence near the amino-terminal end of the collagen domain did not decrease the suppressive activity of SP-D. We hypothesize that SP-D can dampen lymphocyte responses to exogenous stimuli and protect the lung against collateral immune-mediated damage.     

Metabolic mapping of the effects of oral alcohol self-administration in rats

A method for the quantitation of protein carbonyls, which have been widely employed as markers of protein oxidative damage, is described. Protein carbonyls were derivatized with tritiated sodium borohydride and the tritiated proteins were separated on SDS-PAGE. Protein bands, visualized by Coomassie blue staining, were then excised and incubated in 30% H2O2 at 60 degrees C for 48 h. Tritium, incorporated into the proteins, was quantitated by liquid scintillation counting after gel solubilization by H2O2. This method can be applied to the measurement of carbonylation of specific proteins as it employs SDS-PAGE and has the advantage that unreacted NaB3H4 in the labeling reaction mixture need not be removed. The present method, when combined with immunochemical detection of protein carbonyls, should be very useful in the quantitation of oxidative damage to individual proteins.     

A review of the principles of pulse oximetry and accuracy of pulse oximeter estimates during exercise

OBJECTIVE: The outcomes of patients with squamous cell carcinoma of the anal canal treated by either sphincter-preserving procedures or radical surgery were evaluated, with the goals of identifying factors predicting treatment failure and quantifying results of salvage therapy in patients with recurrent disease. BASIC PROCEDURES: A population-based study on all patients in all 159 hospitals of the Department of Veterans Affairs (VA) from 1987 to 1991 was carried out. Data were compiled from several national computerized VA data sets. Supplementary information from local tumor registrars also was obtained, including demographic information, discharge summaries, operative reports, pathology reports, and medical oncology and radiation oncology summaries. From these sources, information on tumor histology, tumor stage, tumor grade, presence of regional or distant metastases, surgical procedures, use of chemotherapy and radiation therapy (RT), toxicity of chemotherapy and RT, development of recurrent disease, treatment of recurrence, survival, and cause of death were obtained. MAIN FINDINGS: Four hundred five patients with anal cancer were identified by computer search, and 204 (51%) were evaluable; 164 of 204 (80%) had squamous cell carcinoma, 137 of whom (84%) were treated with sphincter-preserving procedures, and 27 of whom (16%) were treated by by radical surgery. One hundred fourteen of 138 (83%) were treated by multimodality therapy, which we defined as local excision followed by chemotherapy and RT. The mean dose of RT among patients treated by multimodality therapy was 4200 +/- 540 cGy and 82% of those treated with multimodality therapy received 5-FU/mitomycin C. Recurrent disease was diagnosed in 43 of all 149 patients (29%) with potentially curable disease. (stages I-III) Multivariate analysis revealed that stage at diagnosis (p = 0.04) and method of treatment (p = 0.03) were the sole predictors of recurrence. Fifty-three percent of patients who underwent salvage abdominoperineal resection (APR) are alive, whereas only 19% who underwent salvage chemotherapy with or without RT are alive. PRINCIPAL CONCLUSIONS: These data indicate that multimodality therapy currently is being employed in the majority of patients with squamous cell carcinoma of the anal canal in the VA system. Tumor stage and method of treatment appear to affect the likelihood of development of recurrent disease. Salvage APR has curative potential. Results with salvage chemotherapy and RT are disappointing.     

Effects of ethanol administration on components of the ubiquitin proteolytic pathway in rat liver

Hepatic protein accumulation during ethanol administration may result partly from an ethanol-elicited decline in hepatic protein degradation, which we have previously shown. We conducted the current studies to examine the effects of ethanol administration on the levels of hepatic ubiquitin, an 8.5-kd protein which is an important mediator of extralysosomal protein catabolism. Rats were pair-fed liquid diets containing either ethanol (36% of calories) or isocaloric maltose-dextrin for 1 to 5 weeks. Ubiquitin was immunochemically quantified by competitive enzyme-linked immunosorbent assay (ELISA) in crude cytosol fractions from whole liver and in 12,000g supernatants of hepatocyte lysates. Ubiquitin levels in hepatic cytosol fractions of ethanol-fed rats exceeded those of controls by about 30%. Isolated hepatocytes from ethanol-fed animals also showed a 40% to 75% elevation of ubiquitin above that in cells of pair-fed controls and this difference exceeded the relative rise in hepatocellular protein. In hepatocyte lysates subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting, we detected monomeric ubiquitin and higher molecular mass ubiquitin-protein conjugates. However, the immunoblot analyses revealed no quantitative changes in the level of either free or conjugated ubiquitin. The ubiquitin conjugating activity of crude and diethyl aminoethyl-fractionated liver cytosols of ethanol-fed rats had equal capacities to those from controls in catalyzing the formation of ubiquitin-protein conjugates. Our findings indicate that chronic ethanol consumption increased the level of immunoreactive ubiquitin in rat liver. This may have resulted from enhanced ubiquitin production because of an ethanol-elicited stress response and/or decreased catabolism of ubiquitin and its conjugates. Our findings also provide no indication that the ethanol-elicited reduction in hepatic proteolysis is because of a ubiquitin-mediated mechanisms.     

Ventricular interdependence: significant left ventricular contributions to right ventricular systolic function

This article reviews diastolic and systolic ventricular interaction, and clinical pathophysiological conditions involving ventricular interaction. Diastolic ventricular interdependence is present on a moment-to-moment, beat-to-beat basis, and the interactions are large enough to be of physiological and pathophysiological importance. Although always present, ventricular interdependence is most apparent with sudden postural and respiratory changes in ventricular volume. Left ventricular function significantly affects right ventricular systolic function. Experimental studies have shown that about 20% to 40% of the right ventricular systolic pressure and volume outflow result from left ventricular contraction. This dependency of the right ventricle on the left ventricle helps to explain the right ventricular response to volume overload, pressure overload, and myocardial ischemia. The septum and its position are not the sole mechanism for ventricular interdependence. Ventricular interdependence causes overall ventricular deformation, and is probably best explained by the balance of forces at the interventricular sulcus, the material properties, and cardiac dimensions.     

Behavioral training for parents of retarded children: alternative formats based on instructional manuals

A series of instructional manuals in behavior modification with retarded children was tested as a self-contained resource and as part of three larger training programs involving different amounts of professional assistance to parents: telephone consultations, training groups, training groups plus home visits. One hundred and sixty families were randomly assigned to the four training conditions or to a delayed-treatment control group. The 20-week treatment period emphasized the programming of self-help skills, but also provided an introduction to programming language skills and managing behavior problems. The manuals-alone format was as effective as the more expensive training formats in producing gains in children's self-help skills and fostering knowledge of behavioral principles in mothers. The two group-training formats produced more efforts at behavior-problem management, greater gains in knowledge of principles by fathers, and higher self-confidence as teachers. Telephone consultation was generally the least effective training format; the manuals-alone condition was surprisingly effective. Some implications of the results for future strategies of family intervention were discussed.     

Appendicular and ureteral adenomyomas. Problem of induction of the stroma in the endometriosis foci

Among 15 chelating agents tested, sodium-2,3-dimercaptopropane 1 sulfonate (DMPS), 2,3-dimercaptopropanol (BAL), sodium-mercaptoethyliminodiacetate (MEIDA), and D-penicillamine (PA) exerted an influence on the excretion of Hg and its distribution in the organs. The excretion pattern however, is different for these compounds, and, from the practical point of view, a favourable effect is exhibited only by DMPS which enhances the urinary excretion rate and lowers the Hg-concentration in all organs.     

Quantitative gas chromatography,using retention times

Diffusion of an injected sample within a gas chromatographic column does not begin from a point source but from a band. Therefore the method of calculating relative areas by using retention time × peak height may require a correction factor to give a more accurate estimate of peak areas. When this correction was applied, the analysis was comparable with that obtained by the more time-consuming triangulation method.