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Biomedical subjects

C Vecchi

Publications and source records attributed to C Vecchi.

At least 19 recordsLinked to original sources
PubMed2006

Phenotypic plasticity in Passiflora suberosa L.(Passifloraceae): induction and reversion of two morphs by variation in light intensity.

Leaf morphology may vary considerably even within a branch of Passiflora suberosa plants. Leaves are of a typical green type in shaded areas, but in open fields turn into violet, and apparently have greater thickness and trichome density. The proximate causes and the adaptive meaning, if any, for the existence of the violet morph are still unknown. By cultivating P. suberosa clones under two light regimes (total and partial exposure to sunlight), we consecutively induced (first year) and then reversed (second year) the appearance of the violet morph. We evaluated the corresponding changes in morpho-anatomic and chemical leaf characteristics. Plants that were grown under partial sunlight had a greater size and did not alter their green color, but those grown under total sunlight changed into violet, were smaller in size and their leaves were tougher, thicker, and had a greater number of trichomes. The violet morph had increased anthocyanins and phenolic derivatives. It also showed cellular hypertrophy, a greater number of cell layers in the mesophyll, and a lignified pericycle. Since these morphs are interchangeable by changing light conditions, we inferred that they are not determined by genotypic diversity, but are mainly a result of a physiological response to light stress, and thus part of P. suberosa phenotypic plasticity.

Anthocyanins↗
PubMed2002

Search for alpha4 and alpha7 nicotinic acetylcholine receptor markers in a pedigree of benign familial infantile convulsions (BFIC).

In this study we investigate the possible involvement of the recently reported locus for benign familial infantile convulsions (BFIC) in human chromosome 19 and that of the neuronal acetylcholine receptor alpha4 (CHRNA4) and alpha7 (CHRNA7) subunits in a family with at least twelve clinically diagnosed cases of BFIC. Six polymorphic microsatellite markers covering the BFIC locus on chromosomal region 19q, one marker for CHRNA4 (chromosome 20) and two for CHRNA7 (chromosome 15) were used for the screening. The two-point lod score analysis showed no evidence of BFIC phenotype on chromosome 19. Similarly, when markers for chromosome 20 (CHRNA4 intron1, Amplimer: CHRNA4. PCR.1) and chromosome 15 (D15S165 and D15S1010) were used, score analysis showed no indication of linkage. The most likely interpretation of these results is that BFIC is a genetically heterogeneous form of epilepsy.

Epilepsy, Benign Neonatal↗
PubMed1998

Gamma irradiation can reduce muscle damage in mdx dystrophic mice.

We report the effects of a single gamma irradiation delivered to the soleus muscle of one limb of normal and mdx mice at the age of 16-20 days. At 45, 75 and 90 days of age transverse cryostat sections from the mid-belly of the muscles were used for microscopic examination. In normal mice the growth of fibres was appreciably reduced by irradiation without fibre loss. In the irradiated soleus of mdx mice the number of the regenerated centrally nucleated fibres was very small and the total number of fibres was remarkably reduced. The number of the peripherally nucleated fibres, presumably surviving since the birth of the animal, was almost consistently larger than in the contralateral non-irradiated limb. The cross-sectional area of the irradiated fibres was smaller. It is well known that proliferation and fusion of satellite cells are required both for regeneration after fibre damage and for the normal postnatal growth of muscle fibres: irradiation appears to reduce regeneration and growth. It is suggested that irradiation reduces damage by reducing fusion associated with growth. Our hypothesis indirectly indicates a significant link between dystrophin deficiency and fibre necrosis and accounts well for many features of mouse dystrophy under natural and experimental conditions.

Animals↗
PubMed1998

Solid state NMR spectroscopy study of molecular motion in cyclomaltoheptaose (beta-cyclodextrin) crosslinked with epichlorohydrin.

Dry and hydrated insoluble cyclomaltoheptaose (beta-cyclodextrin, beta-CD) polymers have been investigated by solid state 13C NMR spectroscopy techniques such as cross polarization/magic angle spinning with dipolar decoupling (CP/MAS), magic angle spinning both with (DD-MAS) and without (MAS) dipolar decoupling and CP/MAS dipolar dephasing (dd-CP/MAS) to allow the assignment of the main 13C signals. In the solid state, the presence of water in the samples resulted in a better resolution reflecting increased mobility. Two distinct components (crosslinked beta-CD and polymerized epichlorohydrin) have been found. The molecular mobility of these two components has been analyzed in terms of relaxation parameters such as 13C spin lattice relaxation (T1) and 1H spin lattice relaxation in the rotating frame (T1 rho). The T1 values of the polymers show that the beta-CD trapped inside the polymers does not seem to undergo changes in its mobility whatever the amount of epichlorohydrin. The addition of water to beta-CD significantly increases the T1 values reflecting strong interaction between beta-CD and the solvent. The T1P values obtained reflect the homogeneous nature of the materials.

Carbohydrate Sequence↗
PubMed1998

Astra blue and basic fuchsin double staining of plant materials.

Methods for double staining plant materials using astra blue and basic fuchsin are described here. These methods can be applied to free hand and microtome sections embedded in paraffin, paraplast or historesin. Also, they can be used to study isolated epidermal peels and pollen preparations. Temporary, semipermanent and permanent preparations were studied. Astra blue stained polysaccharides of the cell wall such as cellulose and pectins. Basic fuchsin showed an affinity for lignified, suberized or cutinized walls. The easy preparation of the reagents, excellent color contrast of the histological preparations, and brief staining times of some methods makes them useful for both routine research and didactic purposes. Also, excellent color or black and white photomicrography can be obtained after the double staining described here.

Coloring Agents↗
PubMed1996

[Primary thrombocythemia in a female carrier of IgA deficiency].

We describe a case of essential thrombocythemia observed in a 67-year-old woman with severe IgA-deficiency. The the best of our knowledge, this is the first report concerning the onset of a chronic myeloproliferative disease (CMPD) in a patient affected with primary immunodeficiency, in particular IgA-defect. The association may be merely coincidental; otherwise hemopoietic growth factors acting on myeloid progenitor cells could play a role in this relationship. It has recently been shown that serum levels of many cytokines are elevated in patients with CMPD and probably contribute to enhance proliferation of the malignant clones; on the other hand interleukin-6 seems to account for reactive thrombocytosis, and significant amounts of circulating interleukin-4 and interleukin-6 have been detected in IgA-deficient patients. Overproduction of the two cytokines may depend on recurrent infections, but it could also represent a primary abnormality, with a putative role in the pathogenesis of the immune defect. These findings suggest that high levels of growth factors could induce myeloid hyperproliferation and so expose stem cells to genetic mutations responsible for malignant transformation.

Aged↗
PubMed1992

Presence of HCV RNA in serum of asymptomatic blood donors involved in post-transfusion hepatitis (PTH).

To study the causes of residual posttransfusion hepatitis, serum from implicated donors was tested by PCR for the presence of HCV RNA. Of 20 anti HCV negative donors, 4 were HCV RNA positive and thus, infective. The results suggest that higher-level investigations are necessary for prospective donors who present blood enzyme abnormalities or other questionable characteristics.

Alanine Transaminase↗
PubMed1992

Behavior of antibody profile against hepatitis C virus in patients on maintenance hemodialysis.

The prevalence of anti-hepatitis C virus (HCV) in dialysis setting is still a nonstandard datum. In particular, it is not known of the phenomenon is stable or increasing or decreasing, even in a given geographical area. We studied the behavior of anti-HCV prevalence during a 12-month follow-up in 415 hemodialysis patients treated at a single institution and belonging to a limited geographical area with standard HCV endemic. Point prevalence of anti-HCV has shown a tendency to growth linked in part of the incidence of infection, in part to new positivities in patients already on dialysis treatment. More than 50% of the new HCV-positive patients, had no history of classical parenteral transmission of the virus. These findings suggest that HCV infection is a phenomenon on the increase in dialysis units and that dialysis treatment emerges as an independent risk factor in contracting infection.

Aged↗
PubMed1991

HCV RNA in serum of asymptomatic blood donors involved in post-transfusion hepatitis (PTH).

A group of blood donors involved in post-transfusion hepatitis was investigated for the presence of the anti-HCV antibody and of HCV RNA as a more direct infection marker. RNA was extracted from serum, reverse transcribed and amplified using primers which belonged to the non structural region. The amplified product of the PCR reaction was 582 base pairs. Seven (25.9%) of the 27 blood donors examined were found anti-HCV-positive by ELISA; five (71.4%) of these were HCV RNA positive. Among the 20 anti-HCV-negative blood donors, four (20.0%) were HCV RNA positive. ALT levels were below 45 UI/l in 18 donors, while the other nine had ALTs over the limit accepted for transfusion. The anti-HCV-negative HCV RNA-positive blood donors had normal ALTs. Our study offers a direct explanation for the substantial proportion of residual cases of anti-HCV-positive post-transfusion hepatitis and suggests the necessity of creating a register of blood donors who have at some time presented blood enzyme abnormalities and for whom second level investigations such as HCV RNA should be used.

Base Sequence↗
PubMed1989

Food allergy in preterm infants fed human milk.

In 80 preterms aged 9-24 months (mean age: 15.9) and in 80 sex- and age-matched full-terms the frequency of atopic diseases and of positive skin tests to 8 food and 6 inhalant allergens was determined. The two groups did not differ as to overall percentages of cutipositive subjects and patients with atopic diseases. In particular, frequencies of positive skin tests to foods and of atopic dermatitis (the peak prevalence of which occurs early in infancy) were similar in preterm (16.2 and 7.5%, respectively) and full-term (13.7 and 5.0%, respectively) infants. We suggest that preterm infants fed human milk are not at increased risk of developing food allergy and related diseases and that the absorption of antigens through the immature intestine does not seem to favor the development of an IgE sensitization to foods.

Animals↗
PubMed1988

Bilirubin photoconversion induced by monochromatic laser radiation. Comparison between aerobic and anaerobic experiments in vitro.

Structural and geometric photoisomerization of bilirubin bound to human serum albumin was investigated. Solutions were irradiated with monochromatic light emitted by an Ar ion laser, the 457.9, 488.0 and 514.5 nm wavelengths being selected. Photoproducts were separated and analysed by h.p.l.c. Visible-absorption spectra of pure ZZ-bilirubin, ZE-bilirubin and lumirubin in the eluent were registered in the 350-550 nm region by collecting single fractions by h.p.l.c. Wavelength-dependence of bilirubin photoconversion was studied within photoequilibrium and up to a large decrement of the total concentration. Experiments were performed in aerobic and anaerobic conditions in order to assess the contribution of the photo-oxidation to the overall process. The presence of O2 was found to increase the rate of bilirubin degradation and unexpectedly to favour lumirubin production. The ability of 514.5 nm irradiation to induce bilirubin cyclization was definitively confirmed.

Bilirubin↗
PubMed1988

Variation in thin filament size in the skeletal muscle of the frog.

The sartorius muscle of Rana esculenta was fixed and dehydrated by different methods and cross-sections of sarcomeres of different lengths were examined by electron microscopy. The area within the outlines of the thin filaments in negatives was measured using a high-resolution television system and a graphics tablet or by using a microdensitometer and computer processing the images with a density threshold above the background level. In all specimens the area of the thin filaments in the I-bands was found to be larger than in the S-zones of the A-bands where the thick and thin filaments interpenetrate. The difference was statistically significant and independent of the length of the sarcomere. The results are in agreement with previous observations in glycerol-extracted fibres. It is suggested that the change in size of the thin filaments might be accounted for by some interaction with the thick filaments.

Actin Cytoskeleton↗
PubMed1987

Phototherapy in the management of neonatal hyperbilirubinemia: efficacy with light sources emitting more than 500 nanometers.

The clinical action of green fluorescent lamps, properly filtered to remove wavelengths of less than 500 nm, was investigated in a group of 23 newborns with different initial serum bilirubin concentrations. The serum bilirubin levels were measured at 6, 12, 24, and 48 hours after the beginning of phototherapy. These results are compared with those obtained, under the same experimental conditions, in a group exposed to commercial green lamps. Similar bilirubin decline rates were observed in the two experiments. In general, these data confirm the satisfactory clinical efficacy of the green light in phototherapy and prove, in particular, that the blue component present in the emission spectrum of the commercial green lamps has a negligible effect on the bilirubin degradation process.

Bilirubin↗
PubMed1986

Phototherapy for neonatal jaundice: clinical equivalence of fluorescent green and "special" blue lamps.

The relative efficacy of fluorescent green (Sylvania F20T12/G) and "special" blue (Westinghouse F20T12/BB) lamps in the phototherapy of jaundiced neonates was investigated. Two groups of low birth weight infants with a mean gestational age of 35 weeks and mean birth weight of 1930 gm, who developed hyperbilirubinemia within the first 5 days of life, were given green or blue lamp phototherapy under the same irradiation conditions. No statistically significant difference in plasma bilirubin concentrations was found between the two groups after 24 or 48 hours of treatment. Because recent measurements indicate that green lamps are much less efficient than special blue lamps for the production of Z, E isomers of bilirubin in vitro and in vivo, the clinical equivalence of these two types of lamps seems to support the hypothesis that production of structural photoisomers of bilirubin is the main mechanism of phototherapy in humans. Therefore, fluorescent green lamps provide an alternative to special blue lamps for treatment of neonatal hyperbilirubinemia.

Bilirubin↗
PubMed1985

Laser investigation of bilirubin-photobilirubin photoconversion.

The reversibility of the configurational photoisomerization process of bilirubin (BR) with laser lines in the blue-green spectral region is investigated. Photoisomerization efficiency of BR is found to depend strongly on wavelength, and to decrease when the excitation wavelength is increased from blue to green. Reversion of BR photoisomers (identical to photobilirubin, PBR) back to native BR is demonstrated for several laser lines by irradiating PBR/BR mixtures with wavelengths greater than the excitation wavelengths. Green lines turn out to be very efficient for PBR----BR reversion. The PBR concentrations at photoequilibrium, obtained from the spectrophotometric data, are in close agreement with the corresponding values measured with the high performance liquid chromatography technique in the case of 10 nm bandwidth filtered light reported in the literature. The 457 nm blue laser line produces 32% PBR concentration at photoequilibrium; only 14, 7, and 3% PBR concentrations are produced by the blue-green lines at 488, 501, 514 nm, respectively. The effect on the photostationary PBR/BR mixture of successive irradiations with different wavelengths, and the influence of the wavelength sequence are reported. In the case of blue lines our results support the assumption of the first-order kinetics for the BR in equilibrium PBR photoreaction. Departures are observed with green-lines (501, 514 nm). The present results, together with the i) good clinical efficiency reported for fluorescent green lamps; and ii) slow elimination of configurational photoisomers in infants, tend to confirm the lumirubin-pathway as the main mechanism for phototherapy, and call for clinical investigation of narrow-spectrum lamps with peak emission wavelength in the (biologically safer) 480 divided by 530 nm range.

Bilirubin↗
PubMed1984

Lymphocyte proliferation in neonatally thymectomized rats.

Autoradiography has been used to evaluate lymphocyte proliferation in the neonatally thymectomized rat in comparison with the normal animal. The data obtained show that the proliferative activity of lymphocytes is greatly increased in the thymus-dependent areas 4-6 weeks after thymectomy, whereas it is normal or slightly increased 3 months later. It seems plausible to assume that a thymus factor or chalones in situ produced by specific cells normally regulate the proliferation of thymus-derived cells. The increase of the proliferative activity accounts for the repopulation of the thymus-dependent areas, which are completely replenished in the older animals. Recirculation of the thymus cells is not confined to the thymus-dependent areas.

Animals↗