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Biomedical subjects

Federico Bianco

Publications and source records attributed to Federico Bianco.

13 recordsLinked to original sources
PubMed2006

A chemical shift imaging study on regional metabolite distribution in a CADASIL family.

A chemical shift imaging (CSI) study was performed to directly assess relative concentrations of N-acetylaspartate (NAA), Cho and Cr metabolites in normal- and abnormal-appearing brain tissue of asymptomatic and symptomatic members of a single family with a neuropathologic, genetic and electrophysiological confirmed diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. The aim of the investigation was to evaluate clinical findings and metabolite abnormalities as early appearance of axonal injury in this syndrome. The main findings related statistically significant decreases in the mean metabolite ratios for NAA/Cr, NAA/Cho and Cho/Cr in the anterior parts in comparison with the posterior parts of the centrum semiovale in symptomatic and asymptomatic patients. The effect was considerably greater in the symptomatic patients, indicating a strong correlation between CSI and pathology results. No differences were found between the two areas in the control group. Although lactate signals were hardly detectable in individual spectra, there was a trend toward increased Lac/Cr values in the anterior parts with respect to the posterior parts in the patient group, with the effect particularly evident in the asymptomatic subjects with the gene mutation.

Adult↗
PubMed2006

Pituitary macroadenomas: preoperative evaluation of consistency with diffusion-weighted MR imaging--initial experience.

PURPOSE: To prospectively evaluate use of diffusion-weighted (DW) magnetic resonance (MR) images and apparent diffusion coefficient (ADC) maps for determination of the consistency of macroadenomas. MATERIALS AND METHODS: The study protocol was approved by the institutional ethics committee, and informed consent was obtained from all patients. Twenty-two patients with pituitary macroadenoma (10 men, 12 women; mean age, 54 years +/- 17.09 [standard deviation]; range, 21-75 years) were examined. All patients underwent MR examination, which included T1-weighted spin-echo and T2-weighted turbo spin-echo DW imaging with ADC mapping and contrast material-enhanced T1-weighted spin-echo imaging. Regions of interest (ROIs) were drawn in the macroadenomas and in normal white matter on DW images, ADC maps, and conventional MR images. Consistency of macroadenomas was evaluated at surgery and was classified as soft, intermediate, or hard. Histologic examination was performed on surgical specimens of macroadenomas. Mean ADC values, signal intensity (SI) ratios of tumor to white matter within ROIs on conventional and DW MR images, and degree of enhancement were compared with tumor consistency and with percentage of collagen content at histologic examination by using analysis of variance for linear trend. RESULTS: The mean value of ADC in the soft group was (0.663 +/- 0.109) x 10(-3) mm(2)/sec; in the intermediate group, (0.842 +/- 0.081) x 10(-3) mm(2)/sec; and in the hard group, (1.363 +/- 0.259) x 10(-3) mm(2)/sec. Statistical analysis revealed a significant correlation between tumor consistency and ADC values, DW image SI ratios, T2-weighted image SI ratios, and percentage of collagen content (P < .001, analysis of variance). No other statistically significant correlations were found. CONCLUSION: Findings in this study suggest that DW MR images with ADC maps can provide information about the consistency of macroadenomas.

Adenoma↗
PubMed2005

The plant alkaloid Sanguinarine affects swine granulosa cell activity.

Sanguinarine (SA) has been used in toothpastes and oral rinse products and has been recently applied to livestock nutrition. This study was undertaken to examine the reproductive-related consequences of this feeding supplementation, evaluating SA effects (10, 100 and 300 nM) on swine granulosa cell steroidogenesis, oxidative enzyme activities (peroxidase, catalase and superoxide dismutase), and proliferation. Since angiogenesis is fundamental for follicle development, we also tested the impact of SA exposure on vascular endothelial growth factor (VEGF) production. SA had no effect on proliferation and did not alter progesterone production, although it significantly reduced estradiol synthesis at the two highest concentrations tested (100 and 300 nM). SA addition to granulosa cell culture inhibited VEGF production and increased peroxidase and catalase activities at all tested concentrations while superoxide dismutase activity was increased only at 300 nM. Our data suggest that SA can negatively affect some key biochemical parameters of ovarian granulosa cells.

Alkaloids↗
PubMed2005

Gilles de la Tourette syndrome and voluntary movement: a functional MRI study.

Tourette syndrome (TS) is hypothesised to be caused by an abnormal organization of movement control. The aim of this study was to use functional magnetic resonance imaging to study motor cortex activation in a TS patient. Usual and unusual self-paced voluntary movements were performed. The TS patient displayed supplementary motor area (SMA) activation during both tasks. This activation reflects a continuous use of the SMA to perform the voluntary motor movements required in both tasks. Moreover, the absence of tics during the execution of these voluntary motor tasks suggests that tic activity may be suppressed by additional mental effort.

Adult↗
PubMed2005

Angiogenic activity of swine granulosa cells: effects of hypoxia and vascular endothelial growth factor Trap R1R2, a VEGF blocker.

The possible role played by hypoxia and vascular endothelial growth factor (VEGF) in the regulation of follicular angiogenesis was studied in a three-dimensional fibrin gel model. Granulosa cells from follicles >5mm were subjected to normoxia (19% O2), partial (5% O2) or total (1% O2) hypoxia and their culture media were collected and used to stimulate porcine Aortic Endothelial Cells (AOC) included in the fibrin matrix. A suspension of AOC on microcarrier beads was pipetted in a fibrinogen solution (1 mg/ml PBS) before the addition of 1250 IU thrombine (250 microl) to catalize the gel formation. Granulosa cell conditioned media were tested in the presence or absence of VEGF Trap R1R2 (150 ng/ml), a potent VEGF inhibitor, that had its efficacy tested by adding VEGF (100 ng/ml) to AOC culture. Endothelial cell proliferation was measured at 48, 96, 144, 192 h by means of Scion Image Beta. A significant (p < 0.01) increase of AOC proliferation at each time of measurement was induced by culture media from granulosa cells subjected to partial (except at the end of the first 48 h) and total hypoxia compared to control and normoxia conditions, and by VEGF. VEGF Trap significantly (p < 0.01) inhibited the stimulatory effect of media conditioned by granulosa cells cultured in hypoxic conditions. These data suggest that hypoxia stimulates angiogenic activity of granulosa cells possibly by means of VEGF which could represent the main effector in promoting endothelial cell proliferation.

Animals↗
PubMed2005

EGCG, a major component of green tea, inhibits VEGF production by swine granulosa cells.

Vascular Endothelial Growth Factor (VEGF) plays a pivotal role in the physiological ovarian angiogenic process: its production appears to be stimulated by the hypoxic environment which takes place during follicle development. Recently, epigallocatechin-3-gallate (EGCG) from green tea has been used in livestock nutrition as an alternative to antibiotics. However, despite many potential benefits of EGCG consumption, it is also important to get an insight on the possible reproductive-related consequences of feeding supplementation: in fact this substance has been found to inhibit angiogenesis, a process fundamental for follicle development. Therefore, we evaluated the effect of EGCG (5 and 50 microg/ml) on the production of the main angiogenetic factor, VEGF, by swine granulosa cells cultured in normoxia (19% O2), partial (5% O2) or total hypoxia (1% O2). In addition, we studied the effect of the catechin on cell proliferation. Our data demonstrate that both partial and total hypoxia stimulated VEGF production. EGCG reduced VEGF production independently of the O2 condition: 50 microM was the most effective doses. Granulosa cell proliferation was inhibited by EGCG even if only by the highest concentration. This effect might possibly be due to the decrease induced in VEGF production. Therefore feeding supplementation with EGCG should be carefully considered.

Animals↗
PubMed2005

Epigallocatechin-3-gallate from green tea negatively affects swine granulosa cell function.

The use of herbs as additives in livestock nutrition as an alternative to antibiotics is becoming a new goal in animal production. It is known that green tea exerts antimicrobial activity owing to specific flavonoid compounds named catechins, primarily represented by epigallocatechin-3-gallate (EGCG). Remarkably, despite many potential benefits of green tea and EGCG consumption, it is also important to get an insight on the possible reproductive-related consequences of feeding supplementation. To this purpose, granulosa cells were harvested from follicles > 5mm and treated with 5 and 50 microg/ml of EGCG in order to evaluate the effects on the main parameters of granulosa cell function: steroidogenesis, by measuring progesterone and estradiol-17beta production, and proliferation, one of the major feature of ovarian follicular growth. Moreover, as the genesis of new vessels has been demonstrated to be fundamental for follicle development, we evaluated the effect of EGCG on the production of the main angiogenetic factor, VEGF, by swine granulosa cells. Finally, since reactive oxygen species (ROS) might be involved in the control of female reproductive activity, we studied the effect of EGCG on superoxide anion (O2-) and hydrogen peroxide (H2O2) production by swine granulosa cells and on the activity of the scavenging enzyme superoxide dismutase (SOD). EGCG significantly (p < 0.05) inhibited proliferation, steroidogenesis, VEGF and O2- production by swine granulosa cells; on the contrary, H2O2 levels and SOD activity were stimulated (p < 0.05) by the catechin. Therefore, since our data demonstrate that EGCG has a negative effect on reproductive performances in swine, feeding supplementation should be carefully considered.

Animals↗
PubMed2005

Cobalt chloride, a hypoxia-mimicking agent, modulates redox status and functional parameters of cultured swine granulosa cells.

Hypoxia occurs physiologically during ovarian follicle growth; this deprivation represents a triggering stimulus for the production of vascular endothelial growth factor (VEGF) by proliferating granulosa cells, which are mostly responsible for the growth of the follicle. Moreover, the steroidogenic activity of these cells ensures a receptive environment for the implantation and development of the early embryo. The present paper reports the adaptive response of swine granulosa cells to cobalt chloride (CoCl(2), a chemical hypoxia-mimicking agent. The effects of the treatment were evaluated on cell proliferation, steroidogenesis and VEGF production. In addition, because mithocondrial reactive oxygen species (ROS) are possibly involved in O(2) sensing, ROS levels and scavenging enzyme activity were investigated. In the present study, CoCl 2 had no effect on progesterone production, although it significantly reduced oestradiol synthesis. The addition of CoCl(2) to granulosa cell culture stimulated VEGF production and the generation of hydrogen peroxide. Chemical hypoxia had different effects on scavenger enzyme activities: the activity of superoxide dismutase was enhanced, that of peroxidase reduced and catalase activity was unaffected. The net result is a 'pro-oxidant' state, which appears to be possibly involved in the stimulation of VEGF production, thus inducing follicular angiogenesis.

Analysis of Variance↗
PubMed2004

The effects of reduced oxygen tension on swine granulosa cell.

Follicular growth is characterized by an augmented vascularization, possibly driven by a fall in the oxygen supply. The present study was undertaken to investigate the effects of hypoxia on swine granulosa cells. At first, we quantified oxygen partial pressure (pO2) in follicular fluid from different size follicles; the granulosa cells collected from large follicles (>5 mm) were subjected for 18 h to normoxia (19% O2), partial (5% O2) or total hypoxia (1% O2). The effects of these conditions were tested on the main parameters of granulosa cell function, steroidogenesis and cell proliferation, and on vascular endothelial growth factor (VEGF), nitric oxide (NO) and superoxide anion (O2-) production. Oxygen tension in follicular fluid was negatively related to follicular size, pointing out a gradual reduction during follicular growth. Severe hypoxic conditions determined a reduction of both 17beta estradiol and progesterone production, while partial hypoxia did not seem to affect them. Hypoxia increased VEGF as well as O2- production in swine granulosa cells without impairing cell growth; in addition, it decreased NO output. We may conclude that physiological hypoxia could play a pivotal role in the follicular angiogenic process stimulating VEGF synthesis by granulosa cells. ROS are possibly involved in hypoxic signalling.

Animals↗
PubMed2004

Effect of reduced oxygen tension on reactive oxygen species production and activity of antioxidant enzymes in swine granulosa cells.

During follicle growth swine granulosa cells are physiologically exposed to a progressive oxygen shortage. It has already been shown that hypoxia stimulates angiogenesis through an increase of VEGF production, however, despite considerable progress in the understanding of the final events induced by cellular hypoxia, the signal transduction pathway remains elusive. Recent evidence suggest a role for Reactive Oxygen Species (ROS) as hypoxia signal transducer. Granulosa cells were isolated from pig follicles (> 5 mm) and cultured for 18 h in normoxic (19% O2), hypoxic (5% O2) or anoxic (1% O2) conditions. Following the incubation ROS (O2- and H2O2) production and the activity of scavenging enzymes (SOD, catalase and peroxidase) were determined. It was apparent from our data that ROS generation was reduced by hypoxia. On the contrary, SOD and peroxidase, but not catalase, increased their activity. Further studies are needed to verify whether ROS are involved in signalling hypoxia.

Animals↗
PubMed2003

Visualization of evolving status epilepticus with diffusion and perfusion MR imaging.

Since Kojewnikoff's first description of epilepsia partialis continua, isolated case reports and small case series have elucidated the disease. However, few imaging studies have been performed. We report a case in which serial diffusion and perfusion MR imaging allowed monitoring of the changes in hemodynamic and cell membrane permeability until the resolution of clinical and electrical epileptic activity.

Aged↗
PubMedDate not supplied

Early diagnosis in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL): the role of MRI.

The aim of our work was to evaluate the early presence of white matter changes on magnetic resonance imaging (MRI) in young asymptomatic children of patients with full-blown cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in whom DNA analysis revealed a Notch3 Cys146Tyr missense mutation on chromosome 19. Brain MRI was performed in all subjects using axial and coronal spin-echo proton density and T2-weighted images, axial fluid-attenuated inversion recovery (FLAIR) and sagittal and axial T1-weighted images. In asymptomatic subjects with Notch3 gene mutation, MRI showed small T2 hyperintense foci in periventricular and subcortical white matter. Routine use of MRI in the initial phases of a CADASIL diagnostic work up and the subsequent recognition of early abnormal findings in asymptomatic subjects may lead to prompt diagnosis of the disease in these patients. Moreover, these findings suggest that genetic screening is warranted in the presence of a suspect clinical history with specific MRI abnormalities.

Adult↗