Highly crystalline strontium ferrites SrFeO(3-δ): an easy and effective wet-chemistry synthesis.

The synthesis of strontium ferrite SrFeO(3-δ) has been explored through wet-chemistry methods in order to optimize a quick, easy and reproducible method to obtain the perovskite in pure crystalline form with a high yield. Among the three investigated synthetic paths, (i) coprecipitation of hydroxides, (ii) coprecipitation of oxalates and (iii) polyol-assisted coprecipitation, only the second one was effective in obtaining the desired perovskite modification as a single phase. The products were analyzed by means of powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), to determine the crystalline structure and the chemical composition of the sample surface, respectively, and to optimise the synthetic process. Pure samples were further characterised by means of inductively coupled plasma (ICP-AES) analysis, nitrogen adsorption, elemental analysis, temperature programmed reduction (TPR) and Mössbauer spectroscopy.

Synthesis, characterization and in vitro cytotoxicity of new organotin(IV) derivatives of N-methylglycine.

The synthesis and characterization of new coordination compounds of some diorganotins(IV) with N-methylglycine (sarcosine) are reported; all these derivatives mainly tend to assume a chelate structure. As single crystals were not obtained, a large number of experimental techniques were used to accomplish a definitive characterization and determination of their structure. Results obtained by (1)H/(119)Sn NMR, FT-IR and (119)mSn-Mössbauer spectroscopy and thermogravimetric analysis allow us to deduce the pentacoordination for 1:1 (Sn/sarcosine) derivatives [R(2)SnCl(2)(Sar)](+)Cl(-) (R=Me, n-Bu) in a trigonal-bipyramidal structure, and the hexacoordination for 1:2 complexes [R'(2)Sn(Sar)(2)](2+)2Cl(-) (R'=Me, n-Bu, Ph) in an octahedral structure; however, the probability of partially or totally non-chelate structures for some adducts increases with the steric hindrance of the R/R' groups and the number of the sarcosine molecules bound to the tin atom, so that they give rise to fluxional equilibria in solution. Finally, the synthesized compounds have been tested for in vitro cytotoxic activity against human adenocarcinoma HeLa cells showing, in some cases, strong activity even at low concentration.

Electrospray ionization mass spectrometric study of the hydrolysis-polycondensation process of Sn(OBu(t))(4).

The oligomerization of Sn(OBu(t))(4) in the sol-gel process has been studied by several different analytical approaches. Electrospray ionization (ESI) mass spectrometry was highly effective in describing the first species produced by the hydrolysis-polycondensation reactions. Mössbauer spectroscopy has elucidated the fast behavior of the hydrolytic oligomerization process, while calorimetric data have demonstrated the high enthalpy of the reaction in the presence of different solvents.

Metal- and ligand-centered monoelectronic oxidation of mu-nitrido[((tetraphenylporphyrinato)manganese)phthalocyaninatoiron)], [(TPP)Mn-N-FePc]. X-ray crystal structure of the Fe(IV)-containing species [(THF)(TPP)Mn-N-FePc(H(2)O)](I(5))02THF.

The reaction of mu-nitrido[((tetraphenylporphyrinato)manganese)(phthalocyaninatoiron)], [(TPP)Mn-N-FePc], with I(2) in THF develops with the formation of two different species, i.e., [(THF)(TPP)Mn-N-FePc(H(2)O)](I(5)).2THF (I) and [(TPP)Mn(IV)-N-Fe(III)Pc](I(3)) (II). On the basis of single-crystal X-ray work and Mössbauer, EPR, Raman, and magnetic susceptibility data, I, found to be isostructural with the corresponding Fe-Fe complex, is shown to contain a low-spin triatomic Mn(IV)=N=Fe(IV) system (metal-centered oxidation). Data at hand for II (Mössbauer, EPR, Raman) show, instead, that oxidation takes place at one of the two macrocycles, very likely TPP (ligand-centered oxidation). The same cationic fragment present in I, and containing the Mn(IV)=N=Fe(IV) bond system, is also obtained when (TPP)Mn-N-FePc is allowed to react in THF with (phen)SbCl(6) (molar ratio 1:1). There are indications that the use of (phen)SbCl(6) in excess (2:1 molar ratio), in benzene, probably determines further oxidation with the formation of a species showing the combined presence of the Mn(IV)-Fe(IV) couple and of a pi-cation radical.

Molecular epidemiology of TT virus in Italy and phylogenesis of viral isolates from subjects at different risk for parenteral exposure.

The prevalence and genotype distribution of human TT virus (TTV) in Italy were analysed in 593 subjects at different risk of parenteral infection who included blood donors, patients with chronic type C hepatitis (HCV), thalassemic patients, patients on haemodialysis, human immunodeficiency virus type 1 (HIV-1)-negative intravenous drug users (IVDUs), and HIV-1-infected subjects (IVDUs, heterosexual contacts and homosexual males). Plasma TTV-DNA was detected using nested PCR with primers deduced from the N22 region of the open reading frame 1 (ORF-1) and from the untranslated region (UTR) of the viral genome. Phylogenetic analysis of the sequences obtained from ORF-1 was also undertaken. A high prevalence of plasma TTV-DNA was observed using the UTR primers, with rates varying from 83-100% in the study groups. Using the N22 primers, HIV-1 positive IVDUs and homosexual males, haemodialysed patients and thalassemic patients had a significantly higher TTV prevalence (range: 23.0-86.1%) than blood donors, who displayed a high frequency of positivity (10.6%). Sequence analysis of 127 N22-positive isolates revealed that 42.5% were of type 1, 53.5% of type 2, 2.4% of type 3, and that two isolates (1.6%) were closely related to genotypes 1-2 but distinct from the other major genotypes. TTV-2 was significantly more prevalent in patients at high risk for parenteral infection and in HIV-1 positive homosexuals. In sequential samples from 15 TTV-infected subjects, N22 sequences were detectable persistently in 12 (80.0%) and UTR sequences persisted in all 15 patients over a mean period of 29.6 months. This data indicates that TTV is widespread in Italy in parenterally exposed subjects, and that the infection frequently persists.

Helicobacter pylori CagA seropositivity does not influence inflammatory parameters, lipid concentrations and haemostatic factors in healthy individuals.

BACKGROUND: H. pylori CagA seropositivity has been recently associated with ischaemic heart disease. OBJECTIVE: To evaluate whether H. pylori virulence has any effect on certain circulating coagulation factors and on markers of systemic inflammation in healthy individuals. DESIGN: Prospective cohort study. SETTING: Haematology and gastroenterology unit at a university teaching hospital. SUBJECTS: A total of 494 consecutive asymptomatic blood donors attending a blood bank. MEASUREMENTS: Blood analysis for haemostatic factors, lipids concentrations, inflammatory parameters as well as determination of anti H. pylori IgG and CagA reactivity by ELISA assayes. RESULTS: The overall prevalence of H. pylori infection was 53%; 56% of H. pylori positive sera expressed CagA reactivity. CagA seropositive subjects did not differ significantly from CagA negative or H. pylori negative subjects in values for lipids, haemostatic factors, or inflammatory parameters. CONCLUSIONS: CagA seropositivity is not associated with increased systemic inflammation or with raised concentrations of haemostatic factors - predictors of ischaemic heart disease - in healthy individuals.

Tetrakis(thiadiazole)porphyrazines. 2. Metal Complexes with Mn(II), Fe(II), Co(II), Ni(II), and Zn(II).

The synthesis and general chemical physical characterization of the following new classes of complexes derived from tetrakis(thiadiazole)porphyrazine (TTDPzH(2)), i.e., [(TTDPz)M(DMSO)(2)] (M = Mn(II), Fe(II)), [(TTDPz)M](H(2)O)(2), and [(TTDPz)M] (M = Mn(II), Fe(II), Co(II), Ni(II), Zn(II)) are reported. The IR spectra in the region 4000-200 cm(-)(1) show for all the species typical modes of the TTDPz skeleton and specific absorptions of the thiadiazole ring. The UV-visible spectra in different media show the expected absorptions in the Soret and Q-band regions. Inspection of the IR spectra of the two six-coordinate adducts [(TTDPz)M(DMSO)(2)] and of their corresponding species containing DMSO-d(6) clearly indicate that DMSO is O-bonded to the central metal in both species (nu(SO) located at 918 and 940 cm(-)(1) for the Fe(II) and Mn(II) species, respectively), differently from the findings for DMSO (S-bonded) in the Fe(II) and Ru(II) phthalocyanine analogues. The complexes [(TTDPz)M](H(2)O)(2) and [(TTDPz)M] are all tetracoordinate species, the water molecules for the hydrated species being very likely only weakly ligated at the peripheral thiadiazole rings of the macrocycle. Some additional information on the oxidation and spin state of the complexes has been achieved by Mössbauer spectra (Fe) and room-temperature magnetic susceptibility measurements, and data at hand are compared, when allowed, with those of the parallel classes of metal phthalocyanine complexes.

Diorganotin(IV) complexes of pyridoxal thiosemicarbazone: synthesis, spectroscopic properties and biological activity.

The complexes [SnR2(L)] (R = Me, Et, Bu, Ph; H2L = pyridoxal thiosemicarbazone) have been prepared and characterized. In the light of the spectral properties of the complexes in the solid state (IR, mass, Mössbauer) the bideprotonated thiosemicarbazonato anion is O(phenolic)-, N(3)-, S-bonded to the tin atom which probably has trigonal bipyramidal coordination with N(3) atom and R groups occupying equatorial positions. NMR ( 1H, 13C and 119Sn) data in CDCl3 or DMSO-d6 suggest that this coordinative picture remains in these solutions. The ethyl, butyl and phenyl derivatives suppress proliferation of Friend erithroleukaemia cells (FLC). Of the pyridoxal thiosemicarbazone complexes so far evaluated. [SnBu2(L)] and [SnPh2(L)] showed the lowest thresholds for inhibition of FLC proliferation. The effects of these compounds on DMSO-induced differentiation of FLC, DNA synthesis and reverse transcriptase were also assayed.

Primary thrombocythemia and pregnancy: treatment and outcome in fifteen cases.

Pregnancy in patients with primary thrombocythemia (PT) is reported to be often complicated by recurrent abortion and fetal growth retardation. Fifteen pregnancies in nine patients with PT are reported. Nine pregnancies had a good outcome, with the birth of a healthy infant. There were two spontaneous abortions and three intrauterine deaths. One pregnancy was electively terminated after extensive thrombosis in the splanchnic district requiring surgical entero-resection. In five pregnancies the mother received no treatment; in ten pregnancies acetylsalicylic acid (ASA) was prescribed to the mother as soon as she was found pregnant, subcutaneous heparin was added from the middle trimester in seven cases. In patients treated with ASA and subcutaneous heparin pregnancies had a good outcome. Administration of ASA and heparin during pregnancy appears to improve the outcome in patients with PT and can prevent severe maternal complications, but requires close monitoring.

[Hemimegalencephaly: description of a clinical case]. / Emimegaloencefalia: descrizione di un caso clinico.

The Authors describe a case of hemimegalencephaly (HME) which appeared with seizures and severe hypotonia in a twelve days old female new born. The eeg alterations aroused of HME suspicion, confirmed from the cerebral TAC. Later on clinical characteristics showed a serious worsening of the illness. THe exitus was caused from the status epilepticus when the child was eight months old before hemispherectomy. Medical and surgical treatments are discussed pointing out the indications and the complications of hemispherectomy.

Evidence for polynuclear aggregates of ferric daunomycin. A Mössbauer, EPR, X-ray absorption spectroscopy and magnetic susceptibility study.

The interaction of the antitumor agent daunomycin (DN) with ferric iron has been analysed by Mössbauer spectroscopy, EPR, extended X-ray absorption fine structure (EXAFS), and magnetic susceptibility measurements. In contrast to literature data, at millimolar iron and anthracycline concentrations no solitary Fe(DN)3 complexes are formed in appreciable amounts. The Mössbauer spectroscopic analysis revealed severe dependencies on temperature, on the preparation procedure, the time allowed for equilibration, and on the metal/ligand ratio. The Mössbauer spectra exhibit two components: a broad magnetic sextet and a quadrupole doublet at an Fe/DN molar ratio of 1:3 and exclusively a doublet at a molar ratio of 1:20, indicating an equilibrium of these two spectral components. The EPR spectra are dominated by a signal at g(eff) = 2. Double integration of the EPR signals enabled the determination of their spin density and a correlation between EPR and Mössbauer spectra. The Mössbauer sextet species is EPR invisible and corresponds to magnetically ordered polynuclear aggregates with high magnetic anisotropy. EXAFS and susceptibility measurements provide additional evidence for the formation of polynuclear aggregates of ferric daunomycin. The quadrupole doublet species in the Mössbauer spectra correlates with the g = 2 signal in EPR. This species is also related to a magnetically ordered system, exhibiting, however, superparamagnetic behavior due to less magnetic anisotropy. Since daunomycin forms dimers in aqueous solution at millimolar concentrations, we conclude that the cooperative phenomena observed in EPR and Mössbauer spectra are a consequence of its stacking effects.

Diorganotin dihalide complexes of 2,2'-biimidazole. A preliminary study of their inhibitory effects on cell division.

We report the synthesis of new complexes with the general formula (R2SnX2)y.H2BiIm, where y = 1 or 2; R = Me, Et, Bun; X = Cl or Br (for R = Et) and H2BiIm = 2,2'-Biimidazole. The complexes have been characterized by elemental analysis and Mössbauer, infra-red and 1H n.m.r. spectroscopy and tested (like the ligand, Me2SnCl2 and Et2SnCl2) against P388D1 leukemic cells.

Beta-TG and plasma catecholamines levels after sympathetic stimuli in hypertensives and patients with peripheral vascular disease.

The influence of the sympathetic nervous system on platelet functions in vivo is still controversial. The aims of our study were to compare the response to various sympathetic stimuli in normal subjects and in patients with essential hypertension (HT) or peripheral vascular disease (PVD) and to evaluate any correlations among plasma levels of catecholamines, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4). In basal conditions beta-TG and PF4 values in the HT patients were higher than those observed in the controls of the same age but lower than those of the PVD patients. Although the different sympathetic stimuli (90 degrees tilting, handgrip, treadmill test, bicycle test) caused a significant increase of the plasma epinephrine (E) and norepinephrine (NE) levels, they did not modify the beta-TG and PF4 levels in any of the groups studied. The platelet activation indices, therefore, regardless of the basal values, do not seem to be influenced by sympathetic stimulation.

Platelet activation indices and apolipoproteins in hypertensive patients.

We have studied the platelet activation indices beta-thromboglobulin (beta-TG and platelet factor 4(PF4), triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL) and apolipoprotein (A1, A2, B, C2, C3, E) profiles of 22 untreated essential hypertensive subjects (WHO stages 1 and 2) and 22 controls, to see if there might be some causal relationship between lipoprotein abnormalities and greater platelet activation. The results showed the patients had both greater platelet activation than the controls, as demonstrated by higher plasma beta-TG levels (P less than 0.01) and lower apolipoprotein A2 levels (P less than 0.05). However there were no significant correlations between the platelet activation indices and the plasma levels of apolipoproteins, lipoproteins or lipids in either group.

Plasma beta-thromboglobulin levels and claudication degrees in patients with peripheral vascular disease.

In 30 patients with varying degrees of claudication and 40 normal subjects, plasma levels of beta-thromboglobulin were determined. These were significantly higher (p less than 0.01) in the patients than in age-matched controls; in the control group the beta-thromboglobulin values resulted slightly higher in older subjects. No correlation was found between beta-thromboglobulin and the severity of the vascular disease, assessed on the basis of the pain-free interval on the treadmill.