D and C Red No. 9: Genotoxic or non-genotoxic carcinogen?

The azo-compound, D and C Red No. 9 was assayed for genotoxicity in vivo using the rat micronucleus test and the rat ex vivo liver UDS assay. Uniformly negative results were obtained in both assays, even though large oral doses were used (2 g/kg). These results suggest that the tumorigenic effects of this compound in rats are mediated through a non-genotoxic rather than a genotoxic mechanism. Further experiments using additional end-points such as ³²ap-post-labelling would further substantiate this conclusion     

D and C Red No. 9: genotoxic or non-genotoxic carcinogen?

The azo-compound, D and C Red No. 9 was assayed for genotoxicity in vivo using the rat micronucleus test and the rat ex vivo liver UDS assay. Uniformly negative results were obtained in both assays, even though large oral doses were used (2 g/kg). These results suggest that the tumorigenic effects of this compound in rats are mediated through non-genotoxic rather than a genotoxic mechanism. Further experiments using additional end-points such as 32P-post-labelling would further substantiate this conclusion.     

Distribution of Clostridium difficile strains from a North American,European and Australian trial of treatment for C. difficile infections: 2005–2007

Clostridium difficile is a widely distributed pathogen with multiple strain types as determined by restriction endonuclease analysis (REA) and by PCR ribotyping, two well-characterized typing systems. In this study, REA typing was performed on 894 C. difficile isolates from patients enrolled from 16 countries on three continents in two large, recently conducted clinical treatment trials of C. difficile infection. REA group BI (Ribotype 027) isolates were the most common strains identified and were widely distributed throughout North America, but restricted to three of thirteen countries in Europe. REA group J (Ribotype 001) isolates were the most common strains identified in Europe and non-specific REA groups (historically less frequent) were the most common strains identified in Australia. REA groups BI, J, G and CF correlated with specific PCR ribotypes whereas more than one ribotype was found within REA groups Y, BK, and K. International surveillance of C. difficile strains is important to document the changing epidemiology of this enteric pathogen that continues to cause healthcare facility outbreaks and sporadic infections in other settings.     

Vitamin C: poison,prophylactic or panacea?

Ascorbate is an essential enzyme cofactor but is often also regarded as an important antioxidant in vivo, protecting against cancer by scavenging DNA-damaging reactive oxygen species. Recent studies suggest that ascorbate sometimes increases DNA damage in humans. Although there is no evidence that any of these effects are deleterious to humans, we might need to change our thinking about the mechanisms of the antioxidant action of ascorbate in vivo.     

Radiotherapy in lung cancer. Mandatory or optional?

The purpose of the paper is to outline the current treatment strategies in lung cancer focusing on the possibile role of radiotherapy. METHOD: It defines the place of radiotherapy at the main histological types and stadiums proposing indications according to evidence based medicine. CONCLUSIONS: Radiotherapy is mandatory in non-operated NSCLC st. I-II in perioperative or palliative management of superior sulcus tumours; in the combined modality treatment of limited SCLC and in postoperative adjustment of resected single brain metastasis of lung cancer. It is optional after NSCLC segmentectomy; in palliation or postoperative adjuvation of NSCLC st. III Radiotherapy can be chosen as a part of best supportive care at NSCLC st. IV extensive SCLC and in case of multiple brain or localised lytic bone metastases.     

Synaptic ribbon. Conveyor belt or safety belt?

The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.     

Meadow fescue: Festuca elatior L. or F. pratensis Hudson?

The grass commonly called “meadow fescue” is known in the United States asFestuca elatior L. and in Europe asF. pratensis Hudson. Study of the literature and type specimen shows that the nameF. elatior L. is ambiguous and confused. The earliest correctly applied name isF. pratensis Hudson, hence it should be universally adopted.     

Obesity and post-prandial lipid metabolism. Feast or famine?

Both in Western countries and in third world countries there is an increasing incidence of obesity. Obesity per se or insulin resistance associated with obesity may increase cardiovascular risk factors including dyslipidemia, hypertension and Type 2 diabetes. Over the past decade the understanding has increased of specific mediators in the hypothalamus that are involved in regulating food intake and body weight. In obese humans fasting plasma lipids can be normal but postprandial lipid metabolism is abnormal with an accumulation of triglyceride-rich remnant lipoproteins. In viscerally obese men chylomicron remnant catabolism was markedly decreased when compared with lean individuals. The decreased clearance of chylomicron remnants in viscerally obese subjects may be explained by competition between chylomicron remnants and the increased hepatic production of VLDL for clearance by low density lipoprotein receptors. Increased food intake in rodent models of obesity was shown to be associated with a delay in the catabolism of remnant lipoprotein particles. Prevention of hyperphagia was found to correct the impairment in the metabolism of remnant lipoproteins. Under fasting and food restricted conditions the improvement of remnant metabolism was associated with an increased oxidation of remnant lipids as determined by a novel stable isotope breath test. Anti-obesity and lipid lowering drugs have been used for the treatment of obesity. Inhibitors of cholesterol synthesis inhibitors (statins) have been shown to be effective in treating dyslipidemia. Inhibition of cholesterol synthesis with Atorvastatin was shown to improve chylomicron metabolism by increasing chylomicron remnant catabolism in obese subjects as assessed by the newly developed stable isotope breath test.     

Do intrinsic or extrinsic factors limit reproduction in cyclic populations of Clethrionomys glareolus and C. rufocanus?

Changes in reproduction and functional age structure of females in cyclic populations of Clethrionomys glareolus and C. rufocanus were studied by live-trapping individually marked voles during 1980 to 1984 in northern Sweden. A complete population cycle was observed in both species, with a synchronous 'summer-decline' in 1982. In both species, the length of the breeding season became successively shorter towards the peak, and it was extremely short at the decline. When the populations expanding, the density of breeding females increased in a sigmoid way, and thereafter it remained fairly constant throughout the summer. At the decline, the density of breeding females decreased successively from spring to autumn. Year-born females matured and bred in all years except at the decline. Intrinsic factors, such as spacing behaviour of breeding females, are thought to limit the density of breeders in general, but only when the populations are expanding. Other factors such as deteriorating food conditions are more likely to operate at the decline.