Myocardial perfusion in experimentally induced diabetes mellitus

Diabetes mellitus was induced in rabbits by alloxan monohydrate. At the end of six-week period, animals of the control and diabetic groups (8 rabbits each) were sacrificed and their hearts were excised and perfused using Langendorff apparatus. Results revealed that diabetes had adverse effects on myocardial perfusion. The baseline coronary flow and maximum coronary flow were significantly reduced in diabetic hearts as compared with those of the control. The maximum total coronary flow tended to decrease in the diabetic hearts. Products of the metabolic changes which accompanied diabetes might have directly and/or indirectly caused the observed reduction in the coronary vascular capacity of the diabetic heart.     

Epidemiological study of malaria in north Sulawesi, Indonesia by fluorescence and Giemsa staining.

An epidemiological study of malaria infection was conducted in the Likupang District, Minahasa Regency, North Sulawesi Province, Indonesia, during August 2-15, 1991. In this study, 510 people of six villages, representing ages between 1 month to 84 years cooperated voluntarily. Blood smears stained with Giemsa and acridine orange (AO), revealed 33 and 83 malaria parasite positives respectively. This significant difference was due particularly to the fact that AO staining examined under either a daylight- or halogen-illuminated microscope equipped with interference filters was sensitive to detect low-density parasitemia in many subjects previously diagnosed negative by Giemsa staining in the field. The low malaria prevalence obtained by Giemsa staining may have been attributable to the lack of standard-quality diagnostic tools in the field or inadequate observation of the slides. In both staining methods, Plasmodium falciparum was found to be the predominant species, while the remainings were P. vivax or a mixture of both. Subjects infected with P. vivax revealed higher density of parasitemia and gametocytemia than those with P. falciparum.     

Inhibition of microbial growth and metabolism by excess turbulence

Excess turbulence caused by high-intensity stirring inhibited microbial growth and metabolism. In stirred tank bioreactors, the growth rate and lysine biosynthesis decreased in Brevibacterium flavum beyond 900 rpm, the growth rate of Trichoderma reesei on wheat straw beyond 150 rpm, and the growth rate of Saccharomyces cerevisae beyond 800 rpm. The term turbohypobiosis was introduced to describe this inhibition. Turbohypobiosis was characterized by a stress factor F(str) expressing the interaction of medium flow with microbial cells in local turbulent zones, dependent on the energy distribution of the stirring regime. Lysine synthesis was inhibited at significantly lower F(str) values than the growth of B. flavum. The main reason for the inhibition was shear effects causing decreased adenosine triphosphate (ATP) generation, lower O(2) uptake, and lower specific growth rate of bacteria.     

Three-dimensional structure of natural charybdotoxin in aqueous solution by 1H-NMR. Charybdotoxin possesses a structural motif found in other scorpion toxins.

A 600-MHz proton NMR study of natural charybdotoxin, a toxin acting on K+ channels, is reported. The unambiguous sequential assignment of all the protons of the toxin was achieved. The analysis of NOEs and of backbone coupling constants showed the existence of an alpha-helix (residues 10-19) and of an antiparallel beta-sheet in the 26-35 part. Three-dimensional structures were generated by distance geometry, using a set of 114 interresidual calibrated constraints (63 sequential, 47 medium and long range, 4 hydrogen bonds) and 29 phi angles. These structures show that charybdotoxin is composed of a beta-sheet linked to an alpha-helix by two disulphide bridges and to an extended fragment by the third disulphide bridge. Comparison with the other known structures of long and short scorpion toxins shows that this structural motif is common to all these proteins.     

Immediate,lag and time window effects of meteorological factors on ST-elevation myocardial infarction incidence

The influence of several meteorological parameters on acute myocardial infarction (AMI) incidences with immediately and/or delayed effects has been widely reported. It remains unknown whether the individual AMI subtypes reveal similar patterns. To date, generally seasonal variation in ST elevation MI (STEMI) has been investigated. However, these approaches couldn’t detect the effects of changes in multiple meteorological variables on STEMI incidence within a specific season. Therefore, the aim of our study is to explore immediate, delayed and cumulative effects of average daily temperature, atmospheric pressure and humidity on nation-wide STEMI hospital admissions. We linked daily hospitals’ STEMI admission data with meteorological stations’ data according to the patient’s permanent residence. Subsequently, a multivariate analysis based on a main effect generalised linear model, assuming a log-link function with a Poisson distribution, was conducted. With the help of lags, we were able to analyse delayed effects, while the cumulative effects of specific meteorological variables were analysed utilising time windows. As a result, we confirmed immediate and delayed negative effect of low temperature and low relative humidity for all observed lags as well as cumulative average effects of low temperature and low relative humidity for all observed time windows. However, no delayed, single-day effect for atmospheric pressure was detected. Nevertheless, the cumulative average effect was confirmed in all time windows suggesting that prolonged low pressure influences the incidence of STEMI. A novelty of our approach is the comparative examination of immediate, delayed and cumulative effect of specific meteorological variables on the incidence of STEMI. This approach enables us to gain a new insight into the phenomenon studied.     

<Emphasis Type="Italic">Rhaponticum carthamoides</Emphasis> transformed root extract inhibits human glioma cells viability,induces double strand DNA damage,H2A.X phosphorylation,and PARP1 cleavage

Rhaponticum carthamoides transformed root extract induces double strand DNA damage by increasing the number of phosphorylated H2A.X- and cleaved PARP1-positive U87MG cells and patient-derived IV grade glioma cells. Furthermore, treatment of these cells with root extract causes down-regulation of UHRF1 and DNMT1. Transformed root extract is rich in caffeoylquinic acid derivatives, especially tricaffeoylquinic acid derivatives. Our findings demonstrate that the R. carthamoides transformed root extract may trigger apoptosis in glioma cells by induction of DNA damage, PARP cleavage and epigenetic modification.     

Gastric Juice Polymerase Chain Reaction: An Alternative to Histology in the Diagnosis of Helicobacter pylori Infection

Background. Infection from Helicobacter pylori plays a role in several gastroduodenal diseases. The recent availability of molecular techniques, particularly the polymerase chain reaction (PCR), allows us to detect small amounts of this bacterium. The aims of this study were to compare PCR and histological findings and to ascertain the clinical usefulness of H. pylori PCR identification in different biological samples.
Materials and Methods. We studied 94 consecutive patients. Saliva, gastric juice, and four antral and four body biopsies were obtained from each patients. H. pylori was evaluated histologically in two antral and two body biopsies (Giemsa or Warthin-Starry stain). After extraction, DNA was submitted for PCR amplification using the two primers HPU1 and HPU2, which amplified a 411-bp product from the urease gene A.
Results. Forty-nine patients were H. pylori -positive at histological workup. The sensitivity of PCR was 92% for gastric juice, 73% for antral biopsies, 61% for body biopsies, and 13% for saliva. Of the 45 H. pylori -negative patients at histological assessment, 7 (16%) had positive findings on PCR, mainly when gastric juice was examined.
Conclusions. These results indicate that PCR is as sensitive as histological assessment. We suggest that PCR H. pylori detection in gastric juice is a sensitive method for diagnosing this infection.     

The role of migrant networks in the labour market outcomes of Senegalese men: how destination contexts matter

Research on the role of co-ethnic ties in immigrants’ labour market outcomes has reached mixed conclusions. Some argue they are a valuable resource, increasing immigrants’ labour force participation and wages; others find negative effects such as trapping workers in low-quality employment. Thus far very few quantitative studies have investigated systematically the circumstances under which migrant networks work. Taking advantage of unique data on Senegalese men in France, Italy and Spain, this paper shows that the receiving context shapes the role of pre-migration ties. In France, where the Senegalese community is well-established and socio-economically diverse, networks lead to better economic prospects. In contrast, pre-migration ties in Italy and Spain mostly lead to the perpetuation of ethnic niches developed by the Senegalese in small and precarious trade activities. The article emphasizes the benefits of adopting a comparative and diachronic approach and calls for future work on the factors shaping the role of networks.