Participation of CD45, NKR-P1A and ANK61 antigen in rat hepatic NK cell (pit cell)mediated target cell cytotoxicity

AIM Several triggering receptors have been described to be involved in natural killer (NK) cellmediated target cytotoxicity. In these studies, NK cells derived from blood or spleen were used. Pit cells are liver-specific NK cells that possess a higher level of natural cytotoxicity and a different morphology when compared to blood NK cells. The aim of this study was to characterize the role of the NK-triggering molecules NKR-P1A, ANK61 antigen, and CD45 in pit cell-mediated killing of target cells. METHODS 51 Cr-release and DNA fragmentation were used to quantify target cell lysis and apoptosis, respectively. RESULTS Flow cytometric analysis showed that pit cells expressed CD45, NKR-P1A, and ANK61 antigen. Treatment of pit cells with monoclonal antibody ( mAb ) to CD45 ( ANK74 ) not only inhibited CC531s or YAC-1 target lysis but also apoptosis induced by pit cells. The mAbs to NKRP1A (3.2.3) and ANK61 antigen (ANK61) had no effect on pit cell-mediated CC531s or YAC-1 target cytolysis or apoptosis, while they did increase the Fcγ receptor positive (FcγR+) P815 cytolysis and apoptosis. This enhanced cytotoxicity could he inhibited by 3,4-dichloroisocoumarin, an inhibitor of granzymes. CONCLUSION These results indicate that CD45 participates in pit cell-mediated CC531s and YAC-1 target cytolysis and apoptosis. NKR-P1A and ANK61 antigen on pit cells function as activation structures against FcγR+ P815 cells, which was mediated by the perforin/granzyme pathway.     

Depression severity, diet quality, and physical activity in women with obesity and depression

Major depressive disorder (MDD) is prevalent in clinical weight-loss settings and predicts poor weight-loss outcomes. It is unknown whether the severity of depressive symptoms among those with MDD is associated with diet quality or physical activity levels. This knowledge is important for improving weight-loss treatment for these patients. It was hypothesized that more severe depression is associated with poorer diet quality and lower physical activity levels among individuals with obesity and MDD. Participants were 161 women with current MDD and obesity enrolled in the baseline phase of a weight-loss trial between 2007 and 2010. Depression severity was measured with the Beck Depression Inventory II. The Alternate Healthy Eating Index was applied to data from three 24-hour diet recalls to capture overall diet quality. Daily metabolic equivalents expended per day were calculated from three 24-hour physical activity recalls. Greater depression severity was associated with poorer overall diet quality (estimate=-0.26, standard error 0.11; P=0.02), but not with physical activity (estimate=0.07, standard error 0.05; P=0.18), in linear regression models controlling for income, education, depression-related appetite change, binge eating disorder, and other potential confounds. Associations with diet quality were primarily driven by greater intake of sugar (r=0.20; P<0.01), saturated fat (r=0.21; P<0.01), and sodium (r=0.22; P<0.01). More severe depression was associated with poorer overall diet quality, but not physical activity, among treatment-seeking women with MDD and obesity. Future studies should identify mechanisms linking depression to diet quality and determine whether diet quality improves with depression treatment.     

The effect of vegetarian diets on plasma lipid and platelet levels

Vegetarians have an apparent diminished risk for the development of ischemic coronary heart disease. This may be secondary to dietary effects of plasma lipids and lipoproteins, but platelets, which may also play a role, have also been observed to have aberrant functions in vegetarians. We measured plasma lipid and lipoprotein levels, platelet function, platelet fatty acid levels, and platelet active prostaglandins in ten strict vegetarians (vegans), 15 lactovegetarians, and 25 age- and sex-matched omnivorous controls. The most striking observations were a highly significant rise in platelet linoleic acid concentration and a decline in platelet arachidonic acid concentration in both vegetarian subgroups as compared with omnivorous controls. Serum thromboxane and prostacyclin levels as well as results of platelet aggregation studies did not differ among the groups tested. Cholesterol levels were significantly lower in both vegetarian groups as compared with controls, but plasma high- and low-density lipoprotein levels were lower only in the vegan subgroup as compared with omnivores. If diet produces these changes in platelet fatty acid and plasma lipid levels it may contribute to the decreased risk of coronary heart disease and possibly atherosclerosis in vegetarians.     

Determinants of total body oxygen consumption in adults undergoing cardiac catheterization

Oxygen consumption was measured in 500 patients (151 F, 349 M, ages 12–84 yr.) undergoing routine cardiac catheterization. Sex, age, and heart rate were found to be the strongest predictors of oxygen consumption index (OCI). Males had higher OCI values than females at any age. Older patients of both sexes had lower OCI values than younger patients. Heart rate correlated directly with OCI. Treatment with pro-pranolol correlated inversely with OCI. However, after correction for heart rate, there were no significant differences in OCI values between propranolol treated and non-treated patients. A linear regression equation was developed using combinations of variables to predict OCI, and tables are presented for predicting OCI in those patients in whom this variable cannot be directly measured.     

Relation of left atrial size to pulmonary capillary wedge pressure in severe mitral regurgitation

4,071 consecutive cardiac catheterizations were reviewed retrospectively to obtain 56 cases of pure mitral regurgitation among whom chest X-ray, electrocardiography and echocardiography had been performed within 10 days of catheterization. Mitral regurgitation was mild to moderate (1-2+) in 7 of the 56 cases while 49 had more severe regurgitation (3-4+). Left atrial size as measured by echocardiography was found to be enlarged in all but 2 cases. A positive correlation between left atrial size and severity of mitral regurgitation, irrespective of the height of the pulmonary capillary wedge pressure V wave was demonstrated. There was no demonstrable, predictive relationship between left atrial size and pulmonary capillary wedge pressure or electrocardiographic or chest X-ray findings. We conclude that knowledge of left atrial size is predictive of the severity of mitral regurgitation; however, it is not possible to predict the pulmonary capillary wedge pressure or height of the V waves based on a knowledge of left atrial dilatation in patients with pure mitral regurgitation.     

A method for simultaneous study of the karyotype, morphology, and immunologic phenotype of mitotic cells in hematologic malignancies

A major problem in the cytogenetic analysis of hematologic neoplasms has been an inability to identify the cell from which the chromosomes were obtained. We describe a procedure that allows simultaneous analysis of karyotype and cell cytology in mitotic cells. The method differs from conventional cytogenetic analysis in that after mild hypotonic treatment, the cells are cytocentrifuged onto glass slides. In mitotic cells, this procedure often results in adequate spread of the chromosomes within the intact cell membrane. The cytoplasmic structure also remains intact, so that cytologic preparations are of good quality. Morphologic and immunologic identification of mitotic cells can be done using routine hematologic stains, such as Giemsa or Sudan black B, and various antisera using immunofluorescence techniques. The chromosomes can be simultaneously analyzed either without banding on slides stained with Giemsa or with Q-banding on slides stained with immunofluorescence techniques. Identification of numerical and structural karyotype aberrations thus is possible in morphologically identified cells.