Lifestyle and dietary factors, iron status and one-carbon metabolism polymorphisms in a sample of Italian women and men attending a Transfusion Medicine Unit: a cross-sectional study

Iron (Fe) status among healthy male and female blood donors, aged 18–65 years, is estimated. General characteristics and lifestyle factors, dietary habits and major one-carbon metabolism-related polymorphisms were also investigated. An explorative cross-sectional study design was used to examine a sample of blood donors attending the Transfusion Medicine Unit of the Verona University Hospital, Italy. From April 2016 to May 2018, 499 subjects were enrolled (255 men, 244 women, 155 of whom of childbearing age). Major clinical characteristics including lifestyle, dietary habits and Fe status were analysed. The MTHFR 677C > T, cSHMT 1420C > T, DHFR 19bp ins/del and RFC1 80G > A polymorphisms were also assayed. Mean plasma concentrations of Fe and ferritin were 16·6 µmol/l (95 % CI 16·0, 17·2) and 33·8 µg/l (95 % CI 31·5, 36·2), respectively. Adequate plasma Fe concentrations (> 10·74 µmol/l) were detected in 84·3 % and adequate ferritin concentrations (20–200 µg/l) was found in 72·5 % of the whole cohort. Among the folate-related polymorphisms analysed, carriers of the DHFR 19bp del/del mutant allele showed lower ferritin concentration when compared with DHFR 19bp ins/del genotypes. In a sample of Italian healthy blood donors, adequate plasma concentrations of Fe and ferritin were reached in a large proportion of subjects. The relationship of Fe status with lifestyle factors and folate-related polymorphisms requires more investigation to clarify further gene–nutrient interactions between folate and Fe metabolism

OPTICALLY DETECTED MAGNETIC-RESONANCE STUDY ON THE ORIGIN OF THE PHEOPHYTIN TRIPLET-STATE IN D1/D2 CYTOCHROME B-559 COMPLEXES

In order to determine the origin of the photoexcited pheophytin triplet state ((3)Phe) in plant Photosystem II preparations (D1/D2-cyt b-559 complexes) an absorption and fluorescence detected magnetic resonance (ADMR, FDMR) study was conducted in zero magnetic field at low temperatures. The ADMR signal intensity dependence on excitation light flux was linear showing that (3)Phe is formed by a 1-photon process. Upon successive exposure of the sample to strong white light it was shown that (3)Phe is not directly correlated with the primary donor triplet state (3)P680. This is consistent with the absence of a double resonance signal connecting (3)Phe with (3)P680 down to an instrumental sensitivity of Delta I/I (Delta transmission/transmission) below 10(-6). An intermediate state of photoinhibition between intact and fully degraded reaction centres is responsible for the formation of (3)Phe. It may be a conformationally changed state of the reaction centre protein, most likely having a larger distance between P680 and the pheophytin whose triplet state is observed. Factor analysis of the absorption spectra of a series of gradually degraded samples yielded two spectral components which were interpreted as the spectra of fully intact and completely degraded reaction centres

Structural changes and lateral redistribution of photosystem II during donor side photoinhibition of thylakoids

Abstract. The structural and topological stability of thylakoid components under photoinhibitory conditions (4,500/zE.m-2.s-t white light) was studied on Mn depleted thylakoids isolated from spinach leaves. After various exposures to photoinhibitory light, the chlorophyll-protein complexes of both photosystems I and II were separated by sucrose gradient centrifugation and analysed by Western blotting, using a set of polyclonals raised against various apoproteins of the photosynthetic apparatus. A series of events occurring during donor side photoinhibition are described for photosystem II, including: (a) lowering of the oligomerization state of the photosystem H core; (b) cleavage of 32-kD protein D1 at specific sites; (c) dissociation of chlorophyll-protein CP43 from the photosyste

Limits of endoscopic endonasal approach for cranio-vertebral junction tumors

The endoscopic endonasal approach has been recently proposed for cranio-vertebral junction lesions. The more common indication for this sagittal extension of the endonasal route is represented by odontoidectomy for irreducible ventral brainstem compression due to congenital or degenerative conditions. However, in an increasing number of studies its adoption for tumors involving the cranio-cervical junction has been reported. The aim of this study is to consider retrospectively our surgical series, focusing on the advantages and limits of this approach

Light-induced degradation of D2 protein in isolated photosystem II reaction center complex

AbstractWhen isolated photosystem II reaction centers from spinach are exposed to photoinhibitory light in the presence of an electron acceptor, breakdown products of the D2 protein at 28, 25, 23, 18, 9, 5 and 4.5 kDa are detected by immunoblotting with a monospecific anti-D2 polyclonal antibody. In a time—course experiment the 23 and 4.5 kDa fragments show a transient appearance, whilst the others are photoaccumulated. The regions of the D2 protein containing the cleavage sites for the 28 and 18 kDa photoinduced fragments have been identified. Significant degradation of D2 takes place only in the presence of an electron acceptor, and breakdown of the protein is partially prevented by serine-type protease inhibitors