A comparative study of DNA binding and cell cycle phase perturbation by the dinuclear complex of Cd(II) with the condensation product of 2-acetylpyridine and malonic acid dihydrazide N',N'(2) -bis[(1E)-1-(2-pyridyl)ethylidene]propanedihydrazide

Organometallic Cd(II) compounds have recently attracted attention for their anticancer activity. The interaction of the dinuclear complex of Cd(II) with the condensation product of 2-acetylpyridine and malonic acid dihydrazide, N',N'(2) -bis[(1E)-1-(2-pyridyl)ethylidene]propanedihydrazide (Cd(II)H(2) L), with calf thymus DNA (CT-DNA) was monitored by blue shift in UV-vis spectra of the complex. The binding constant of Cd(II)H(2) L complex with CT-DNA was determined (K(B) = 1.8 × 10(4) M(-1) ) and was indicative of minor groove binding. Agarose gel electrophoretic changes in mobility of supercoiled and circular forms of pBR322 and pUC18 plasmids in the presence of the complex suggest that conformational changes in the plasmids occur upon binding of the Cd(II)H(2) L complex. The Cd(II)H(2) L complex induced perturbation of the cell cycle phase distribution and an increase in the percentage of cells in the sub-G1 phase of human cervical cancer HeLa cell line and murine melanoma B16 cell line. Immunoblotting analysis showed the overexpression of Bcl-2 protein with the Cd(II)H(2) L complex.     

Properties of narrow-range ampholytes isolated from wide-range ampholyte preparations

A simple procedure for obtaining useful narrow-pH-range ampholytes from inexpensive laboratory-synthesized ampholytes by preparative isoelectric focusing in Pevikon is described. The narrow range ampholytes prepared in this way are comparable to commercial ampholyte preparation as judged by conductivity, buffer capacity, pH gradient formation, and resolving power. These inexpensive narrow-range ampholytes are particularly well suited to preparative isoelectric focusing applications requiring large quantities of ampholytes.     

Unimodal Latitudinal Pattern of Land-Snail Species Richness across Northern Eurasian Lowlands

Large-scale patterns of species richness and their causes are still poorly understood for most terrestrial invertebrates, although invertebrates can add important insights into the mechanisms that generate regional and global biodiversity patterns. Here we explore the general plausibility of the climate-based “water-energy dynamics” hypothesis using the latitudinal pattern of land-snail species richness across extensive topographically homogeneous lowlands of northern Eurasia. We established a 1480-km long latitudinal transect across the Western Siberian Plain (Russia) from the Russia-Kazakhstan border (54.5°N) to the Arctic Ocean (67.5°N), crossing eight latitudinal vegetation zones: steppe, forest-steppe, subtaiga, southern, middle and northern taiga, forest-tundra, and tundra. We sampled snails in forests and open habitats each half-degree of latitude and used generalized linear models to relate snail species richness to climatic variables and soil calcium content measured in situ. Contrary to the classical prediction of latitudinal biodiversity decrease, we found a striking unimodal pattern of snail species richness peaking in the subtaiga and southern-taiga zones between 57 and 59°N. The main south-to-north interchange of the two principal diversity constraints, i.e. drought stress vs. cold stress, explained most of the variance in the latitudinal diversity pattern. Water balance, calculated as annual precipitation minus potential evapotranspiration, was a single variable that could explain 81.7% of the variance in species richness. Our data suggest that the “water-energy dynamics” hypothesis can apply not only at the global scale but also at subcontinental scales of higher latitudes, as water availability was found to be the primary limiting factor also in this extratropical region with summer-warm and dry climate. A narrow zone with a sharp south-to-north switch in the two main diversity constraints seems to constitute the dominant and general pattern of terrestrial diversity across a large part of northern Eurasia, resulting in a subcontinental diversity hotspot of various taxa in this zone.     

Prevalence of vancomycin-resistant enterococci in hospitalized patients and those living in the community in the Czech Republic

Between July 1, 2002 and December 31, 2003, rectal swabs from both hospitalized patients and community subjects in the Czech Republic were taken to ascertain the prevalence of vancomycin-resistant enterococci (VRE). The swabs were used for isolating and identifying enterococci and their susceptibility to antibiotics. Vancomycin resistance phenotypes were verified by PCR detection of vanA, vanB, vanC1 and vanC2 genes. A molecular biology analysis was performed in Enterococcus faecium VanA strains. During the observed period, 2691 rectal swabs from the hospitalized patients and 6529 rectal swabs from the subjects in community setting were examined. In total, 31 VRE of hospital origin and 13 community-population strains were isolated. The prevalence of VRE in the gastrointestinal tract was 1.9% in the hospitalized patients and 0.4% in the community subjects. The prevailing strains were Enterococcus faecium VanA (61.3%) in the VRE of hospital origin and Enterococcus gallinarum VanC (46.2%) in the community VRE. Mutual comparison between the hospital and community Enterococcus faecium VanA strains showed no similarity.     

Skeletal muscle atrophy is associated with an increased expression of myostatin and impaired satellite cell function in the portacaval anastamosis rat

Proliferation and differentiation of satellite cells are critical in the regeneration of atrophied muscle following immobilization and aging. We hypothesized that impaired satellite cell function is responsible for the atrophy of skeletal muscle also seen in cirrhosis. Myostatin and insulin-like growth factor 1 (IGF1) have been identified to be positive and negative regulators, respectively, of satellite cell function. Using a rat model of cirrhosis [portacaval anastamosis (PCA)] and sham-operated controls, we examined the expression of myostatin, its receptor activinR2b, and its downstream messenger cyclin-dependent kinase inhibitor p21 (CDKI p21) as well as IGF1 and its receptor in the gastrocnemius muscle. Expression of PCNA, a marker of proliferation, and myogenic regulatory factors (myoD, myf5, and myogenin), markers of differentiation of satellite cells, were also measured. Real- time PCR for mRNA and Western blot assay for protein quantification were performed. PCA rats had lower body weight and gastrocnemius weight compared with sham animals (P < 0.05). PCNA and myogenic regulatory factors were lower in PCA rats (P < 0.05). Myostatin, activinR2b, and CDKI p21 were higher in the PCA animals (P < 0.05). The expression of IGF1 and its receptor was lower in liver and skeletal muscle of PCA animals (P < 0.05). These data suggest that skeletal muscle atrophy seen in the portacaval shunted rats is a consequence of impaired satellite cell proliferation and differentiation mediated, in part, by higher myostatin and lower IGF1 expression.     

Evolutionary contingency and SETI revisited

The well-known argument against the Search for ExtraTerrestrial Intelligence (SETI) due to George Gaylord Simpson is re-analyzed almost half a century later, in the light of our improved understanding of preconditions for the emergence of life and intelligence brought about by the ongoing “astrobiological revolution”. Simpson’s argument has been enormously influential, in particular in biological circles, and it arguably fueled the most serious opposition to SETI programmes and their funding. I argue that both proponents and opponents of Simpson’s argument have occasionally mispresented its core content. Proponents often oversimplify it as just another consequence of biological contingency, thus leaving their position open to general arguments limiting the scope of contingency in evolution (such as the recent argument of Geerat Vermeij based on selection effects in the fossil record). They also tend to neglect that the argument has been presented as essentially atemporal, while referring to entities and processes that are likely to change over time; this has become even less justifiable as our astrobiological knowledge increased in recent years. Opponents have failed to see that the weaknesses in Simpson’s position could be removed by restructuring of the argument; I suggest one way of such restructuring, envisioned long ago in the fictional context by Stanislaw Lem. While no firm consensus has emerged on the validity of Simpson’s argument so far, I suggest that, contrary to the original motivation, today it is less an anti-SETI argument, and more an astrobiological research programme. In this research programme, SETI could be generalized into a platform for testing some of the deepest assumptions about evolutionary continuity and the relative role of contingency versus convergence on unprecedented spatial and temporal scales.     

Inheritance of cleft palate in Italy. Evidence for a major autosomal recessive locus

Although several studies have demonstrated familial aggregation of nonsyndromic cleft palate (CP), the mode of inheritance still remains uncertain. We report the results of complex segregation analysis performed in families of 357 consecutive newborns affected with nonsyndromic CP (i.e., CP not a component feature of malformation syndrome, sequence or association), and registered in the North East Italy and Emilia Romagna congenital malformation registries in the period 1981–1993. This sample, based on a large number of consecutive births, in a well-defined geographical area, with quality control to detect associated anomalies and malformation syndromes, is independent of the number of affected subjects in the family and of CP severity, fitness, and survival. We have analyzed, using the mixed model, the whole sample of nonsyndromic CP, including isolated (i.e., without other anomalies) CP (CPI) and CP associated with at least one other anomaly (CPA), for which a diagnosis of malformation syndrome was not possible. When nonsyndromic CP (including CPA) are considered in the analysis, there is no heterogeneity between CPA and CPI nor between CP including hard palate (CPH) and CP of the soft palate only (CPS). POINTER and COMDS programs cannot discriminate between alternative genetic models; only the hypothesis of non-genetic transmission is rejected. The COMDS analysis two-locus model, which indicates that a modifier locus (or loci) operates in addition to a single major locus (SML), does not show evidence of better fit than SML, polygenic, and multifactorial models. When the severity parameter (defined as CPH and CPS) is added, CPI and CPA show heterogeneity. Eventually, when the analysis is limited to CPI and includes information on severity, a recessive SML, with low penetrance and determining CPH, provides a significant best fit. To have defined a genetic model for CPI and provided evidence for SML inheritance suggests that genetic linkage studies could be implemented. This conclusion is in agreement with previous studies which showed a significant association between alleles of transforming growth factor alpha and CP only in humans, and that single recessive genes may play a crucial role during palatogenesis in mice as well as in Brittany spaniels. Application of the candidate genes to human CPH families could reveal whether these genes are involved. Received: 16 December 1996 / Accepted: 16 March 1997     

Plaque volume and plaque risk profile in diabetic vs. non-diabetic patients undergoing lipid-lowering therapy: a study based on 3D intravascular ultrasound and virtual histology

Background

Coronary atherosclerosis progresses faster in patients with diabetes mellitus (DM) and causes higher morbidity and mortality in such patients compared to non-diabetics ones (non-DM). We quantify changes in plaque volume and plaque phenotype during lipid-lowering therapy in DM versus non-DM patients using advanced intracoronary imaging.

Methods

We analyzed data from 61 patients with stable angina pectoris included to the PREDICT trial searching for prediction of plaque changes during intensive lipid-lowering therapy (40 mg rosuvastatin daily). Geometrically correct, fully 3-D representation of the vascular wall surfaces and intravascular ultrasound virtual histology (IVUS-VH) defined tissue characterization was obtained via fusion of two-plane angiography and IVUS-VH. Frame-based indices of plaque morphology and virtual histology analyses were computed and averaged in 5 mm long baseline/follow-up registered vessel segments covering the entire length of the two sequential pullbacks (baseline, 1-year). We analyzed 698 5-mm-long segments and calculated the Liverpool active plaque score (LAPS).

Results

Despite reaching similar levels of LDL cholesterol (DM 2.12 ± 0.91 mmol/l, non-DM 1.8 ± 0.66 mmol/l, p = 0.21), DM patients experienced, compared to non-DM ones, higher progression of mean plaque area (0.47 ± 1.15 mm² vs. 0.21 ± 0.97, p = 0.001), percent atheroma volume (0.7 ± 2.8% vs. ? 1.4 ± 2.5%, p = 0.007), increase of LAPS (0.23 ± 1.66 vs. 0.13 ± 1.79, p = 0.018), and exhibited more locations with TCFA (Thin-Cap Fibro-Atheroma) plaque phenotype in 5 mm vessel segments (20.3% vs. 12.5%, p = 0.01). However, only non-DM patients reached significant decrease of LDL cholesterol. Plaque changes were more pronounced in PIT (pathologic intimal thickening) compared to TCFA with increased plaque area in both phenotypes in DM patients.

Conclusion

Based on detailed 3D analysis, we found advanced plaque phenotype and further atherosclerosis progression in DM patients despite the same reached levels of LDLc as in non-DM patients. Trial registration ClinicalTrials.gov identifier: NCT01773512