Type VI collagen in glomeruli of short- and long-term experimental diabetic rats

Type VI collagen was revealed by high-resolution immunocytochemistry in renal glomeruli from short- and long-term streptozotocin-injected hyperglycaemic rats and from their age-matched normoglycaemic controls. The labellings obtained over the glomerular basement membrane and the mesangial matrix were assessed by quantitative evaluations. The labellings over the glomerular basement membrane were low and sparse in the young normoglycaemic animals but became consistent and increased in intensity with age and in both the short- and long-term diabetic animals. For the mesangial matrix, this was labelled more systematically, and its intensity increased with age and in the short-term hyperglycaemic animals. For the long-term hyperglycaemic animals, the intensities of labelling resembled those of their age-matched controls. These results indicate that type VI collagen appears to be a minor constituent of the extracellular matrix of the rat glomeruli, rather concentrated in the mesangial area in the young control animal. Concomitant with the general modifications of the extracellular matrix occurring with age and diabetes, this component increases, but apparently not with the length of the hyperglycaemic state. © Chapman & Hall     

Fingerprinting ofCaprinae ancient genomic DNA: A preliminary note for studying the history of domestication in sicily

Oligonucleotide primers representing promoter and protein motifs in rats and mice were assayed for PCR amplification of ancient DNA from two sheep and one goat. We show preliminary evidence that this type of primers can be used for genomic fingerprinting of ancient DNA at interspecific level and can help in solving some paleoecological promlems.     

Plasmatic regulation of vascular prostacyclin in pregnancy.

Activity of prostacyclin-stimulating factor was measured in six normal, non-pregnant women, six women in early normal pregnancy, six in late normal pregnancy, and six in late pregnancy complicated by severe pre-eclampsia. The activity was lower in the women in late pregnancy than in those in early pregnancy and the controls but was about normal in those with severe pre-eclampsia. These results may be relevant to the physiology of pregnancy and the pathogenesis of pre-eclampsia.     

A model for the homogeneous isospecific Ziegler–Natta polymerization of olefins: Enantioselectivity in the deuteration and deuteriooligomerization of 1-alkenes

The enantioselectivity found in homogeneous isospecific Ziegler–Natta catalysts for the insertion of 1-alkenes in metal–deuterium or in metalisobutyl bonds is discussed from a theoretical point of view. Nonbonded energy calculations, based on a model of the catalytic site previously proposed by us, indicate that the strong enantioselectivity found in the insertion of 1-alkenes in a metal–isobutyl bond is drastically reduced in the presence of a metal–deuterium bond. In particular, a weak enantioselectivity in favour of a monomer coordinated with the opposite chirality (lower for the case of 1-butene, higher for the case of styrene) is shown to occur in the latter case.     

Swelling of cellulose derivative (HPMC) matrix systems for drug delivery

The water swellable hydrogels are commonly used in the production of solid pharmaceutical dosage systems for oral administration (matrices). Their use allows to obtain the controlled drug release. The key role is played by the transport phenomena which take place: water up-take, gel swelling and erosion, increase in diffusivity due to hydration. Thus, knowledge of these phenomena is fundamental in designing and realizing the pharmaceutical systems.In this work, tablets made of pure hydrogel, HydroxyPropyl-MethylCellulose (HPMC), were produced and immersed in a thermostatic bath filled with stirred distilled water (37 °C). The water up-take was allowed only by radial direction (from the lateral surface) by confining the tablet between two glass slides. Two distinct methods, an optical technique already described in a previous work, and a gravimetric procedure described here, were applied to measure the water concentration profiles along the radial direction in the tablets. The data obtained were used both to clarify the nature of the transport phenomena involved, and to perform a better tuning of a mathematical model previously proposed.     

A sisters’ story: comparative phylogeography and taxonomy of Hierophis viridiflavus and H. gemonensis (Serpentes,Colubridae)

We used a multidisciplinary approach to infer the taxonomy and historical biogeography of Hierophis viridiflavus and H. gemonensis, performing molecular analyses of mitochondrial (16S, Cyt‐b, ND4) and nuclear markers (PRLR), a landmark‐based morphometric study and a cytogenetic analysis. Our data distinguished three main groups in the studied species, corresponding to H. gemonensis and to two monophyletic clades (E and W) within H. viridiflavus. Clades E and W display a significant genetic (about 4% for Cyt‐b and ND4) and morphological divergence and a different morphology of the W sex chromosome (submetacentric in clade E and telocentric in clade W). Taking into account the existing divergence, these clades appear to represent independent phylogenetic units, deserving elevation to species status. Specific names should be H. viridiflavus (Lacépède, 1789) and H. carbonarius (Bonaparte 1833) for clades W and E, respectively. The phylogeography of the studied species is only partially concordant with a general pattern of ‘southern richness and northern purity’ of genetic diversity, whereas H. gemonensis exhibits high genetic diversity at low latitudes (especially in the Peloponnese), H. carbonarius shows a number of different haplotypes both at low (along the southern Italian Apennines and in Sicily) and high latitudes in Italy. Furthermore, a relaxed clock model hypothesizes the differentiation between H. gemonensis and H. viridiflavus sensu lato at about 7 Mya, in the Messinian. Subsequently, the speciation involving H. viridiflavus sensu stricto and H. carbonarius took place in the Quaternary, probably as a result of Pleistocene climatic oscillations. Furthermore, our results are consistent with the existence of several ‘refugia within refugia’ in Italy and in the Balkans and depict the major cladogenesis as allopatric events, mainly driven by paleoclimatic and geographical factors.