Human leukemic cells: Biological action of exogenous human leukemic DNA

Intact exogenous human leukemie DNA derived from cells in culture was taken up by both normal and leukemic recipient human cells, wherein it migrates to the nucleus and becomes associated with host genome. Uptake of exogenous DNA averages about 15–20 percent and was relatively higher in leukemic than in normal cells in a given culture medium.Isologous and homologous human leukemic cells were more sensitive to inhibition by this exogenous DNA than were normal human cells. Both DNA and RNA synthesis were inhibited, but protein synthesis was stimulated — effects similar to those described consequent to exposure to certain viruses.Immunological studies of hamster cells treated with human leukemic DNA failed to show any presence of human surface antigens. The in vivo studies showed that this metabolically active radioactive DNA had migrated to several organs of hamsters and gerbils, the highest labeled DNA activity being found in the testis and kidney of these animals.Prolonged exposure to exogenous leukemic DNA resulted in marked phenotypic changes in normal human fibroblasts, which thus far appear to be heritable. Search for evidence of genotypic changes in these altered cells which might relate these observations to «neoplastic transformation is in progress.     

Approach to Assessment of Risk Factors in Mild Hypertension

Criteria are urgently needed for the early detection of subjects with only mildly raised blood pressure who may be at high risk of developing the complications of hypertension. As a step towards the establishment of such criteria we have examined the association of certain possible “risk” factors—namely, x-ray evidence of cardiac enlargement, high serum cholesterol levels, effort pain, E.C.G. abnormalities, and high systolic blood pressure—with fatal or morbid endpoints in a five-year follow-up study of subjects whose diastolic pressure had been found initially to be between 95 and 114 mm Hg. The index group consisted of 22 patients in whom these end-points occurred. They comprised death from cardiovascular disease, clinical or E.C.G. deterioration, and either an increase in diastolic pressure of at least 10 mm Hg or a diastolic pressure of 115 mm Hg or both. The control group consisted of 22 subjects chosen at random from other respondents with the same range of diastolic pressures and the same age and sex distribution.“Any two or more” of the possible risk factors examined were found to occur significantly more often in the index group than in the controls, suggesting a possible approach to the early detection of high-risk subjects. The value of longterm studies along these lines and the urgent need for them are emphasized.     

Binding of type II nuclear receptors and estrogen receptor to full and half-site estrogen response elements in vitro.

The mechanism by which retinoids, thyroid hormone (T3) and estrogens modulate the growth of breast cancer cells is unclear. Since nuclear type II nuclear receptors, including retinoic acid receptor (RAR), retinoid X receptor (RXR) and thyroid hormone receptor (TR), bind direct repeats (DR) of the estrogen response elements (ERE) half-site (5'-AGGTCA-3'), we examined the ability of estrogen receptor (ER) versus type II nuclear receptors, i.e. RARalpha, beta and gamma, RXRbeta, TRalpha and TRbeta, to bind various EREs in vitro . ER bound a consensus ERE, containing a perfectly palindromic 17 bp inverted repeat (IR), as a homodimer. In contrast, ER did not bind to a single ERE half-site. Likewise, ER did not bind two tandem (38 bp apart) half-sites, but low ER binding was detected to three tandem copies of the same half-site. RARalpha,beta or gamma bound both ERE and half-site constructs as a homodimer. RXRbeta did not bind full or half-site EREs, nor did RXRbeta enhance RARalpha binding to a full ERE. However, RARalpha and RXRbeta bound a half-site ERE cooperatively forming a dimeric complex. The RARalpha-RXRbeta heterodimer bound the Xenopus vitellogenin B1 estrogen responsive unit, with two non-consensus EREs, with higher affinity than one or two copies of the full or half-site ERE. Both TRalpha and TRbeta bound the full and the half-site ERE as monomers and homodimers and cooperatively as heterodimers with RXRbeta. We suggest that the cellular concentrations of nuclear receptors and their ligands, and the nature of the ERE or half-site sequence and those of its flanking sequences determine the occupation of EREs in estrogen-regulated genes in vivo .     

Some pathological studies in two species of Phytophthora

Summary The paper deals with some detailed pathological investigations with two species ofPhytophthora, viz.,Phytophthora palmivora andP. parasitica var.macrospora causing severe fruit rots ofAchras sapota andAnona squamosa respectively. Both the isolates were found pathogenic to a variety of fruits including papaya, tomato, chillis, banana, fig, apple, cucumber, guava, orange, onion bulb and potato tuber. They were, however, non-pathogenic to carrot, zinger, turmeric andColocasia corms. In the seedling inoculation experiment they showed pathogenic nature to castor bean, brinjal, cotton, sesamum, pea, French bean,Cactus sp. andBryophyllum leaves. It is interesting to note that only the Isolate S caused infection to the plants ofVinca rosea L., whereas the Isolate C failed to do so.This work frames up a part of Senior author's M.Sc. (Agri.) Thesis, approved by the University of Poona, India.Respectively, Ex-Junior Research Fellow (1958–60), Indian Council of Agricultural Research, New Delhi; Principal and Professor of Plant Pathology, College of Agriculture, Junagad, (Gujarat) and Mycologist, Wheat Rust Research Station, Mahabaleshwar (Satara Dist.) India.     

Clinical Implications of Cluster Analysis-Based Classification of Acute Decompensated Heart Failure and Correlation with Bedside Hemodynamic Profiles

Background

Classification of acute decompensated heart failure (ADHF) is based on subjective criteria that crudely capture disease heterogeneity. Improved phenotyping of the syndrome may help improve therapeutic strategies.

Objective

To derive cluster analysis-based groupings for patients hospitalized with ADHF, and compare their prognostic performance to hemodynamic classifications derived at the bedside.

Methods

We performed a cluster analysis on baseline clinical variables and PAC measurements of 172 ADHF patients from the ESCAPE trial. Employing regression techniques, we examined associations between clusters and clinically determined hemodynamic profiles (warm/cold/wet/dry). We assessed association with clinical outcomes using Cox proportional hazards models. Likelihood ratio tests were used to compare the prognostic value of cluster data to that of hemodynamic data.

Results

We identified four advanced HF clusters: 1) male Caucasians with ischemic cardiomyopathy, multiple comorbidities, lowest B-type natriuretic peptide (BNP) levels; 2) females with non-ischemic cardiomyopathy, few comorbidities, most favorable hemodynamics; 3) young African American males with non-ischemic cardiomyopathy, most adverse hemodynamics, advanced disease; and 4) older Caucasians with ischemic cardiomyopathy, concomitant renal insufficiency, highest BNP levels. There was no association between clusters and bedside-derived hemodynamic profiles (p = 0.70). For all adverse clinical outcomes, Cluster 4 had the highest risk, and Cluster 2, the lowest. Compared to Cluster 4, Clusters 1–3 had 45–70% lower risk of all-cause mortality. Clusters were significantly associated with clinical outcomes, whereas hemodynamic profiles were not.

Conclusions

By clustering patients with similar objective variables, we identified four clinically relevant phenotypes of ADHF patients, with no discernable relationship to hemodynamic profiles, but distinct associations with adverse outcomes. Our analysis suggests that ADHF classification using simultaneous considerations of etiology, comorbid conditions, and biomarker levels, may be superior to bedside classifications.     

Effects of Varying Epoch Lengths,Wear Time Algorithms,and Activity Cut-Points on Estimates of Child Sedentary Behavior and Physical Activity from Accelerometer Data

Objective

To examine the effects of accelerometer epoch lengths, wear time (WT) algorithms, and activity cut-points on estimates of WT, sedentary behavior (SB), and physical activity (PA).

Methods

268 7–11 year-olds with BMI ≥ 85^th percentile for age and sex wore accelerometers on their right hips for 4–7 days. Data were processed and analyzed at epoch lengths of 1-, 5-, 10-, 15-, 30-, and 60-seconds. For each epoch length, WT minutes/day was determined using three common WT algorithms, and minutes/day and percent time spent in SB, light (LPA), moderate (MPA), and vigorous (VPA) PA were determined using five common activity cut-points. ANOVA tested differences in WT, SB, LPA, MPA, VPA, and MVPA when using the different epoch lengths, WT algorithms, and activity cut-points.

Results

WT minutes/day varied significantly by epoch length when using the NHANES WT algorithm (p < .0001), but did not vary significantly by epoch length when using the ≥ 20 minute consecutive zero or Choi WT algorithms. Minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA varied significantly by epoch length for all sets of activity cut-points tested with all three WT algorithms (all p < .0001). Across all epoch lengths, minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA also varied significantly across all sets of activity cut-points with all three WT algorithms (all p < .0001).

Conclusions

The common practice of converting WT algorithms and activity cut-point definitions to match different epoch lengths may introduce significant errors. Estimates of SB and PA from studies that process and analyze data using different epoch lengths, WT algorithms, and/or activity cut-points are not comparable, potentially leading to very different results, interpretations, and conclusions, misleading research and public policy.     

Exposure to Folate Receptor Alpha Antibodies during Gestation and Weaning Leads to Severe Behavioral Deficits in Rats: A Pilot Study

The central nervous system continues to develop during gestation and after birth, and folate is an essential nutrient in this process. Folate deficiency and folate receptor alpha autoantibodies (FRα-AuAb) have been associated with pregnancy-related complications and neurodevelopmental disorders. In this pilot study, we investigated the effect of exposure to FRα antibodies (Ab) during gestation (GST), the pre-weaning (PRW), and the post weaning (POW) periods on learning and behavior in adulthood in a rat model. In the open field test and novel object recognition task, which examine locomotor activity and anxiety-like behavior, deficits in rats exposed to Ab during gestation and pre-weaning (GST+PRW) included more time spent in the periphery or corner areas, less time in the central area, frequent self-grooming akin to stereotypy, and longer time to explore a novel object compared to a control group; these are all indicative of increased levels of anxiety. In the place avoidance tasks that assess learning and spatial memory formation, only 30% of GST+PRW rats were able to learn the passive place avoidance task. None of these rats learned the active place avoidance task indicating severe learning deficits and cognitive impairment. Similar but less severe deficits were observed in rats exposed to Ab during GST alone or only during the PRW period, suggesting the extreme sensitivity of the fetal as well as the neonatal rat brain to the deleterious effects of exposure to Ab during this period. Behavioral deficits were not seen in rats exposed to antibody post weaning. These observations have implications in the pathology of FRα-AuAb associated with neural tube defect pregnancy, preterm birth and neurodevelopmental disorders including autism.     

Antisense RNA strategies for metabolic engineering of Clostridium acetobutylicum

We examined the effectiveness of antisense RNA (as RNA) strategies for metabolic engineering of Clostridium acetobutylicum. Strain ATCC 824(pRD4) was developed to produce a 102-nucleotide asRNA with 87% complementarity to the butyrate kinase (BK) gene. Strain ATCC 824(pRD4) exhibited 85 to 90% lower BK and acetate kinase specific activities than the control strain. Strain ATCC 824(pRD4) also exhibited 45 to 50% lower phosphotransbutyrylase (PTB) and phosphotransacetylase specific activities than the control strain. This strain exhibited earlier induction of solventogenesis, which resulted in 50 and 35% higher final concentrations of acetone and butanol, respectively, than the concentrations in the control. Strain ATCC 824(pRD1) was developed to putatively produce a 698-nucleotide asRNA with 96% complementarity to the PTB gene. Strain ATCC 824(pRD1) exhibited 70 and 80% lower PTB and BK activities, respectively, than the control exhibited. It also exhibited 300% higher levels of a lactate dehydrogenase activity than the control exhibited. The growth yields of ATCC 824(pRD1) were 28% less than the growth yields of the control. While the levels of acids were not affected in ATCC 824(pRD1) fermentations, the acetone and butanol concentrations were 96 and 75% lower, respectively, than the concentrations in the control fermentations. The lower level of solvent production by ATCC 824(pRD1) was compensated for by approximately 100-fold higher levels of lactate production. The lack of any significant impact on butyrate formation fluxes by the lower PTB and BK levels suggests that butyrate formation fluxes are not controlled by the levels of the butyrate formation enzymes.