Complementation of the temperature-sensitive defect in H5ts125 adenovirus DNA replication in vitro.

Soluble extracts of adenovirus-infected HeLa cell nuclei support DNA replication on exogenous adenovirus DNA templates. Conditions of synthesis using both wild-type and temperature-sensitive extracts have been defined. Nuclear extracts prepared from cells permissively infected with the adenovirus mutant H5ts125 expressed the temperature-sensitive phenotype and could be inactivated at 37 degrees C in vitro. These extracts were completely complemented by the addition of wild-type adenovirus DNA binding protein but not by H5ts125 DNA binding protein. Enhancement by binding protein in the mutant extracts represents replication, as demonstrated by the production of full-sized products and orderly chain elongation originating, as in vivo, at both ends of the linear DNA. Replicative synthesis required the 5'-terminal protein bound covalently to template DNA and could be inhibited by denaturation of this 55,000-dalton protein. Various inhibitors of eukaryotic DNA polymerases, such as aphidicolin and 2',3'-dideoxythymidine triphosphate, inhibited replication of exogenous adenovirus templates in this system as they do in previously reported systems that only elongate endogenous replicating intermediates.     

Short Inter-pregnancy Intervals,Parity, Excessive Pregnancy Weight Gain and Risk of Maternal Obesity

To investigate the relationship among parity, length of the inter-pregnancy intervals and excessive pregnancy weight gain in the first pregnancy and the risk of obesity. Using a prospective cohort study of 3,422 non-obese, non-pregnant US women aged 14–22 years at baseline, adjusted Cox models were used to estimate the association among parity, inter-pregnancy intervals, and excessive pregnancy weight gain in the first pregnancy and the relative hazard rate (HR) of obesity. Compared to nulliparous women, primiparous women with excessive pregnancy weight gain in the first pregnancy had a HR of obesity of 1.79 (95 % CI 1.40, 2.29); no significant difference was seen between primiparous without excessive pregnancy weight gain in the first pregnancy and nulliparous women. Among women with the same pregnancy weight gain in the first pregnancy and the same number of inter-pregnancy intervals (12 and 18 months or ≥18 months), the HR of obesity increased 2.43-fold (95 % CI 1.21, 4.89; p = 0.01) for every additional inter-pregnancy interval of <12 months; no significant association was seen for longer inter-pregnancy intervals. Among women with the same parity and inter-pregnancy interval pattern, women with excessive pregnancy weight gain in the first pregnancy had an HR of obesity 2.41 times higher (95 % CI 1.81, 3.21; p < 0.001) than women without. Primiparous and nulliparous women had similar obesity risk unless the primiparous women had excessive pregnancy weight gain in the first pregnancy, then their risk of obesity was greater. Multiparous women with the same excessive pregnancy weight gain in the first pregnancy and at least one additional short inter-pregnancy interval had a significant risk of obesity after childbirth. Perinatal interventions that prevent excessive pregnancy weight gain in the first pregnancy or lengthen the inter-pregnancy interval are necessary for reducing maternal obesity.     

Enhanced antiarrhythmic efficacy of propafenone when used in combination with procainamide or quinidine

This study evaluated the efficacy and safety of combining propafenone with procainamide or quinidine for treating ventricular arrhythmias in patients in whom procainamide or quinidine therapy alone failed to suppress arrhythmias. In 30 patients, the addition of propafenone resulted in a significant reduction of premature ventricular contraction (PVC) frequency compared to drug-free baseline (406 PVC/hr vs 33, p less than 0.001) and to procainamide or quinidine monotherapy (211 PVC/hr vs 27, p less than 0.01). Propafenone alone was also more effective than either procainamide or quinidine and resulted in significant suppression of PVC compared to the drug-free state (406 PVC/hr vs 38, p less than 0.001). However, higher propafenone doses were necessary during monotherapy as compared to propafenone therapy combined with procainamide or quinidine (730 mg/day vs 480 mg/day, p less than 0.001). Of the 30 patients, 22 required an increase in propafenone dose during monotherapy as compared to combination therapy. Thus, propafenone is an effective antiarrhythmic agent when used in combination with type IA antiarrhythmic drugs. With these combinations, lower doses of propafenone can be utilized effectively than with propafenone alone.     

The use of 7-amino actinomycin D in identifying apoptosis: simplicity of use and broad spectrum of application compared with other techniques

The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states.     

Fear of cancer recurrence in lymphoma survivors: A descriptive study

Abstract

Objectives: Fear of cancer recurrence (FCR) is a common experience among cancer survivors and often persists after the termination of cancer treatments. The purpose of this paper was to evaluate FCR in survivors of Hodgkin’s and diffuse large B-cell lymphomas, given a high rate of survivorship in this patient population.

Research Approach: The parent study was a multi-site, cluster-randomized trial to assess a communication skills intervention: survivorship planning consultation (versus a time-attention control - wellness rehabilitation intervention) to promote transition to survivorship.

Participants & Methodological Approach: 199 patients enrolled in the study and completed a survivorship (or control) consultation one-month after receiving the news of their survivorship status; 141 of those patients (n?=?92 experimental arm, n?=?49 control arm) completed an interview at their 6-month follow-up consultation. In the interview, participants described frequency of FCR, causes of FCR, coping mechanisms, and specific things oncologists said to reduce FCR. Both qualitative and quantitative methods were utilized for analyzing participant responses.

Findings: The majority (88%) of participants reported experiencing FCR, with a higher number of participants in the experimental arm significantly more likely to endorse FCR compared to the control group participants. The main causes of FCR were having medical appointments and concerns about potential relapse and secondary cancers. Participants endorsed utilizing self-sufficient coping mechanisms. As well, participants reported that oncologists most frequently cited specific cure rates of lymphoma to reduce patients’ FCR.

Interpretation & Implications for Psychosocial Providers: Communication skills training programs should emphasize FCR in survivorship consultations.     

Human CD8+ lymphocytes stimulated in the absence of CD4+ cells enhance IgG production by antibody-secreting B cells.

We describe conditions where the addition of stimulated CD8+ lymphocytes from healthy donors to autologous antibody-secreting B cells significantly enhanced IgG production by these cells. In two-step experiments, purified CD8+ lymphocytes were first cocultured with irradiated allogeneic monocytes. These cells developed interleukin 2 receptors, but proliferated only minimally in the absence of CD4+ cells. When added to antibody-secreting B cells, these CD8+ lymphocytes augmented IgG production in a dose-dependent manner in comparison with control CD8+ cells. Studies with T killer cell precursors revealed an inverse correlation between augmentation of antibody synthesis and the generation of MHC class I-restricted cytotoxic activity against lymphocytes from the allogeneic donor. Evidence is presented that CD8+ CD45RA+ CD45RO- can provide B cell help, whereas the generation of CD8+ CD45RA+ CD45RO+ cells inhibits this helper activity. Our studies support the hypothesis that in chronic diseases characterized by CD4+ cell hypofunction, CD8+ cells not only fail to down-regulate antibody production, but can provide B cell help.     

Truncated NF2 proteins are not detected in meningiomas and schwannomas

Neurofibromatosis type 2 is caused by mutations in the NF2 tumor suppressor gene. The NF2 gene encodes a 595‐aminoacid protein, presumably functioning as a membrane‐organizing element. Theoretically, the majority of mutations found in the NF2 gene should lead to a truncated protein product. Using immunoprecipitation with an antibody raised to N‐terminal sequences of the NF2 protein, the authors sought to demonstrate the presence of truncated NF2 proteins in tumors. From 17 of 19 tumors (14 meningiomas and five schwannomas), 12 of which have previously been shown to harbor truncating NF2 mutations, wild‐type NF2 protein was immunopreci‐pitated. From two tumors no protein was precipitated. Truncated NF2 proteins were not observed. The authors conclude that mutant NF2 proteins are unstable and undergo accelerated degradation.