Dextran cross-linked gelatin microspheres as a drug delivery system.

This paper describes the use of oxidized dextran as a cross-linker for the preparation of gelatin microspheres. Microspheres were obtained by a thermal gelation method and their dissolution kinetic was examined. In order to find evidence of sugar mediated cross-linking, swelling tests and gelatin microspheres dissolution experiments were performed. The obtained results indicated that oxidized dextran can form a cross-linked gelatin network which can reduce the dissolution of gelatin. More interestingly, gelatin microspheres treated by both native and oxidized dextran slow down, even if to a different extent, the release of the antitumor drug TAPP-Br used as a model compound. Taken together, our results suggest that oxidized dextran could be an interesting means to cross-link gelatin microspheres allowing the use of this delivery formulation for controlled release of drugs.

[A "plethora", minor and transient, as an immediate cause of a cerebrovascular accident]. / Una "pletora", minima e fugace, come concausa immediata degli episodi di accidenti vascolari cerebrali.

Even if the well-known predisposing factors play an essential role in the realization of cerebrovascular accidents, in these last years the possible importance of the hemoreologic parameters is still a topic under discussion. The authors found a significant increase of the considered hemoreologic parameters (HT, Hb, RBC) in the patients hospitalized for cerebrovascular accidents compared to controls, without differences for gender, even if this increase remained into the limits of normal range. Conversely, no significant differences were found concerning the considered metabolic parameters.

[Arterial hypertension and syncope in an adult patient with coarctation of the aorta]. / Ipertensione arteriosa e sincope in adulto portatore di stenosi istmica dell'aorta.

An uncommon case of aortal coartactation in an adult patient treated, since five years, for hypertension and faintness is described. The surgical treatment led to complete resolution of her symptomatology without drug therapy.

[Erythrocyte carbonic anhydrase in subjects on periodic hemodialysis]. / Anidrasi carbonica eritrocitaria in soggetti sottoposti ad emodialisi periodica.

Red cell carbonic anhydrase isoenzymes I and II have been measured by means of cellulose acetate membrane electrophoresis in patients with chronic renal failure and dependent on periodic hemodialysis; these patients showed a chronic anemia due to many factors. Carbonic anhydrase isoenzymes were higher in uremic and anemic patients than in the controls. Since hemoglobin can act as a protons acceptor from the active site of carbonic anhydrase during the hydratation of CO2 (and vice-versa), the increase of carbonic anhydrase can facilitate, via the Bohr effect, the transfer of the oxygen to the peripheral tissues. Therefore an increase of red cell carbonic anhydrase can constitute a compensating mechanism of anemic hypoxia in uremic patients.

Temporal organization of cerebrovascular accidents: a retrospective, preliminary study about stroke in Ferrara, Italy.

An epidemiologic retrospective study was conducted from January 1984 to December 1988 on subjects admitted into the Institute of Semeiotica Medica of the University of Ferrara (as a general medicine, unselective department) and presenting a stroke. Year, month and hour of onset of symptoms in 141 patients (all resident in Ferrara, mean age 74.3 +/- 8.3 years) were carefully recorded. The definition of precise clock hour was reached only in 108 cases. The data were then analyzed by means of Halberg's single cosinor. Time series analysis showed a seasonal pattern of disease onset, characterized by a circannual rhythm with acrophase in late winter - early spring (-83.9 degrees). A significant circadian rhythm was found too, with acrophase at afternoon (-242.8 degrees).

[Findings in relation to serum and urinary iron in heterozygotic beta-thalassemia]. / Indagine intorno al ferro sierico ed urinario nella beta-talassemia eterozigote.

Iron status (expressed as serum ferritin and iron levels) has been compared in normal and in heterozygous beta-thalassemic subjects. A higher serum ferritin concentration has been found in beta-thalassemic males, showing, therefore, a shift towards super-normal values of the balance between tissue iron and serum ferritin levels. In beta-thalassemic subjects the serum ferritin levels have been found in the normal range and this seems to be correlated with an adequate and ready iron supply by protein transferrin to hyperplastic bone marrow. The higher urinary iron values in normal male subjects can be explained in this way: a large iron supply from the transferrin to the thalassemic erythroid cells limits the contribution from this protein to the urinary iron.