Parameters of the labeling of mitogen-activated murine lymphocytes by [35S]methionine for two-dimensional gel electrophoresis. I. Effect of culture conditions

Labeling with [35S]methionine at a high specific activity is essential to the facile preparation of 2-dimensional gel electrophoretograms with the analytical 2-dimensional charge-size separation procedure (Anderson's ISODALT system). Mitogen-activated T and B lymphocytes subjected to low methionine concentrations would not proceed through cell cycle. In the case of activated B lymphocytes, the use of fetal bovine serum (FBS), dialyzed to lower endogenous methionine concentrations, prevented B cell growth even in the presence of otherwise satisfactory levels of methionine. High concentrations of [35S]methionine (greater than 300 mCi/1) induced B cell death, apparently by radiation damage. Despite these problems, good radioautograms and radiofluorograms of 2D electrophoretograms could be prepared by labeling activated B or T cells in bulk (10(6) cells/ml) with high specific activity [35S]methionine. The polypeptides labeled may be a biased sample since lymphoid cells do not proceed through cell cycle under these conditions. Small numbers (10(3] of activated T cells also yielded satisfactory samples but labeling of small numbers of activated B cells was not possible.     

Very low doses of X-rays can cause human lymphocytes to become less susceptible to ionizing radiation

Cultured human lymphocytes exposed to very low doses of X-raysbecome less susceptible to subsequent higher doses of X-rays.Cells exposed to doses as low as 0.5 rad (cGy) or 1 rad of X-raysat 32–34 h of culture become adapted so that less cytogeneticdamage in the from of chromosome breakage is induced by 150rad administered at 48 h. This response, which does not occurafter high inital doses of X-rays, can be eliminated by 3-aminobenzamide,an inhibitor of poly(ADP-ribose) polymerase.     

Inflammatory pseudotumor of lymph node and spleen: An entity biologically distinct from inflammatory myofibroblastic tumor

Inflammatory pseudotumors (IPTs) of the lymph node and spleen are an uncommon, benign cause of lymphadenopathy and/or splenomegaly that often bear striking clinicopathologic similarities to the inflammatory myofibroblastic tumors (IMTs) found in soft tissues. These tumors have classically been grouped together under the umbrella category of "inflammatory pseudotumor." Recent evidence shows that IMTs are in fact neoplastic processes that often harbor balanced chromosomal translocations involving the ALK kinase gene. These translocations result in expression of ALK kinase in IMTs as assessed by immunohistochemical studies. However, the relationship between IMT and IPT of the lymph node and spleen is uncertain. To determine if ALK tyrosine kinase expression is also present in IPT, 13 cases of IPT (9 involving lymph nodes, 4 splenic lesions) were examined for the presence of ALK tyrosine kinase by immunohistochemical staining on paraffin-embedded tissue. In addition, in situ hybridization studies for Epstein-Barr virus--encoded RNAs (EBER) and immunoperoxidase studies for human herpesvirus-8 (HHV8)--specific proteins were performed. All cases had clinical, morphologic, and immunophenotypic findings typical of IPT and had varying proportions of fibroblastic and inflammatory components. Age ranged from 11 to 75 (median, 40) years; 8 subjects were male, and 5 were female. None of the cases (0 of 13) had positive staining for ALK kinase or HHV8, and in 1 a lymph node (1 of 13) was focally positive for EBV (EBER) by in situ hybridization. The absence of ALK kinase as detected by immunohistochemical studies in IPT of the lymph node and spleen suggests that this entity is biologically distinct from the histologically similar IMT.     

Cortical mechanisms of cocaine sensitization

Behavioral sensitization is the augmented motor-stimulant response that occurs with repeated, intermittent exposure to most drugs of abuse, including cocaine. Sensitization, which is a long-lasting phenomenon, is thought to underlie drug craving and relapse to drug use. Much research has been conducted to determine the neural mechanisms of sensitization. The bulk of this effort has focused on the nucleus accumbens and ventral tegmental area (VTA) that comprise a portion of the mesolimbic dopamine system. Recently, studies have begun to also explore the role of the medial prefrontal cortex (mPFC) in sensitization, in part because this region provides glutamatergic innervation to the VTA and nucleus accumbens. The present review will coalesce these studies into a working hypothesis that states that cocaine sensitization results from a decrease in inhibitory modulation of excitatory transmission from the mPFC to the VTA and nucleus accumbens. The discussion will revolve around how repeated cocaine exposure alters dopamine, gamma-aminobutyric acid (GABA), and glutamate regulation of pyramidal cell activity. It will be proposed that cocaine-induced alterations in cortical transmission occur in two phases. During early withdrawal from repeated cocaine exposure, changes in neurotransmitter release are thought to underlie the decreased inhibitory modulation of pyramidal projection neurons. Following more prolonged withdrawal, the attenuation in inhibitory transmission appears to occur at the receptor level. A model will be presented that may serve to direct future studies on the involvement of the mPFC in the development of cocaine sensitization, which ultimately could lead to development of pharmacotherapies for cocaine addiction.     

Immunoglobulin diversification in embryonic chicken bursae and in individual bursal follicles

Previous studies have shown that the same immunoglobulin (Ig) V lambda gene (V lambda 1) is rearranged in all chicken B cells, and that extensive sequence diversification of this gene occurs during B cell development in the bursa of Fabricius. We used two-dimensional gel electrophoresis to compare the heterogeneity of Ig lambda light chains produced by B cells at different stages of bursal development. Somatically diversified light chains were observed in Ig molecules produced by bursal cells as early as 15 days of embryonic incubation. The two principal species of light chain observed probably represent glycosylated and nonglycosylated forms of lambda chain encoded by alleles of a single lambda gene. Extensive diversification was observed during late embryogenesis. We also studied lambda light chain diversity in cyclophosphamide-treated birds repopulated with normal bursal cells. In these birds, individual bursal follicles are repopulated by single B cell precursors. Follicular cells derived from single B cell precursors were able to produce a spectrum of light chains almost as diverse as that of the total bursal cell population. We used two monoclonal anti-idiotype antibodies to study idiotype expression in individual normal or reconstituted follicles. About 30% of follicles contained 0.1% to 5% of lymphocytes which reacted with one or both of the antibodies. The results indicate that within individual bursal follicles bursa stem cells undergo Ig hyperdiversification.     

Safety and efficacy of internal mammary artery grafts for left main coronary artery disease. A preliminary report

Questions regarding the relative safety and efficacy of internal mammary artery (IMA) grafts versus saphenous vein grafts (SVG) in patients with left main coronary artery disease (LMCAD) have not been specifically addressed in the literature. To elucidate this point, we analyzed 196 patients with LMCAD who underwent myocardial revascularization between January 1975 and December 1981, 98 by IMA and SVG and 98 by SVG, IMA was used most often to bypass the left anterior descending (LAD). Chi Square and "t" tests were performed on all demographic, cardiac and operative data comparing IMA to SVG. All results were non-significant, indicating that the two groups were comparable. Anginal pattern was progressive or unstable in 93%. IMA was used in 4 patients who were on intra-aortic balloon pump. The mean number bypass grafts per patient was 3.1. Postoperative complications were comparable for both groups, including early and late myocardial infarction. Overall operative mortality was 2.6%. Results of a survival analysis indicated no significant difference in the mortality rates of patients operated on by SVG versus IMA-SVG. Cumulative mortality rates at a mean followup of 20.5 months were 12.2% for SVG and 7.1% for IMA patients. Significant mortality risk factors were ejection fraction less than 55% (p less than 0.05); and perioperative myocardial infarction (p less than 0.001). Twenty-five patients with recurrent chest pain underwent repeat cardiac catheterization. This revealed 10 of 10 patent IMA grafts, 6 of 8 single patent SVG to LAD and 6 of 9 patent sequential vein grafts to the diagonal and LAD arteries.(ABSTRACT TRUNCATED AT 250 WORDS)     

Health-related quality of life following percutaneous coronary intervention during the COVID-19 pandemic

Quality of Life Research - During the COVID-19 pandemic, widespread public health measures were implemented to control community transmission. The association between these measures and...