Biomedical subjects

Silvia Bianchi

Publications and source records attributed to Silvia Bianchi.

12 recordsLinked to original sources

PubMed2007

Cardiac autonomic nervous system and risk of arrhythmias in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited systemic microangiopathy with prevalently cerebral manifestations. Among the causes of death, sudden unexpected death seems to occur in a significant number of CADASIL patients. Because potential causes of sudden unexpected death may include cardiac arrhythmias and myocardial infarction, we evaluated risk factors for life-threatening arrhythmias, such as reduced heart rate variability, sympathetic overactivity and QT interval (QTc) prolongation, in 23 CADASIL patients. The relationship of these changes with brain MRI pattern was also investigated. METHODS: Frequency domain measures of heart rate variability (10 minutes recordings) and QTc interval were recorded in 23 CADASIL patients (17 males, 6 females) and 22 healthy age- and sex-matched control subjects. The following heart rate variability spectral parameters were considered at rest during spontaneous and controlled breathing (Cb): total power, very-low-frequency component, low-frequency component, high-frequency component, low-frequency/high-frequency ratio, and Cb-total power, Cb-very-low-frequency component, Cb-low-frequency component, Cb-high-frequency component, Cb-low-frequency/high-frequency ratio. R-to-R wave and QTc interval were also analyzed. All data were statistically compared between CADASIL and control subjects. Conventional brain MRI was performed in patients with CADASIL and T1-weighted and T2-weighted lesion volumes, and were compared with each spectral component of the tachogram. RESULTS: During spontaneous and controlled breathing, total power spectrum and all spectral components (very low frequency component, high-frequency component, low-frequency component) of heart rate variability were significantly reduced in CADASIL patients with respect to controls (P<0.05). The low-frequency/high-frequency component ratio was significantly higher in CADASIL patients than in controls. No significant correlation between heart rate variability spectral parameters and other variables including total brain T2-weighted and T1-weighted lesion volumes were observed in CADASIL subjects. CONCLUSIONS: We found a statistically significant reduction in all frequency domain parameters of heart rate variability associated with a higher low frequency/high frequency ratio for CADASIL patients with respect to normal subjects. These data are consistent with autonomic derangement and suggests that CADASIL patients may be at risk for life-threatening arrhythmias. This could at least in part explain their higher recurrence of sudden unexpected death and should be taken into account in planning therapy.

Adult↗

PubMed2006

Physiology and pathology of notch signalling system.

Notch proteins encode a family of transmembrane receptors that are part of a signalling transduction system known as Notch signalling, an extremely conserved and widely used mechanism regulating programs governing growth, apoptosis and differentiation in metazoans. Notch signalling begins when the Notch receptor binds ligands and ends when the Notch intracellular domain enters the nucleus and activates transcription of target genes. This core pathway is subjected to a wide array of regulatory influences and protein-protein interactions and is correlated with other signalling pathway. This review will summarize recent findings concerning the physiology and pathology of Notch signalling in vascular development and homeostasis. Moreover, the clinical phenotypes of Notch3 signalling system pathology will be described, with particular regard to CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy) for which the most recent pathogenetic hypotheses are reported.

Animals↗

PubMed2006

Lung inflammation in preterm infants with respiratory distress syndrome: effects of ventilation with different tidal volumes.

Ventilation with an inappropriate tidal volume (Vt) triggers lung inflammation, an important predisposing factor of bronchopulmonary dysplasia. It still remains uncertain what the appropriate starting target Vt should be during the acute phase of respiratory distress syndrome (RDS). Our aim was to evaluate lung inflammation in preterm infants undergoing synchronized intermittent positive-pressure ventilation (SIPPV) with two different tidal volumes Vt during the acute phase of RDS. Thirty preterm infants (gestational age, 25-32 weeks) with acute RDS were randomly assigned to be ventilated with Vt = 5 ml/kg (n = 15) or Vt = 3 ml/kg (n = 15). Proinflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF)-alpha) were determined in the tracheal aspirate on days 1, 3, and 7 of life. IL-8 and TNF-alpha levels collected on day 7 were significantly higher (P < 0.05), and mechanical ventilation lasted longer in the group with Vt = 3 ml/kg (16.8 +/- 4 vs. 9.2 +/- 4 days; P = 0.05). In conclusion, our data show significantly higher lung inflammation in preterm infants ventilated with Vt = 3 ml/kg, suggesting a role for Vt = 5 ml/kg in reducing both inflammatory response during the acute phase of RDS and the length of ventilation. Whether the use of this starting Vt prevents bronchopulmonary dysplasia requires further study.

Humans↗

PubMed2006

Bronchoalveolar lavage with diluted porcine surfactant in mechanically ventilated term infants with meconium aspiration syndrome.

BACKGROUND: To evaluate the efficacy and safety of bronchoalveolar lavage (BAL) with diluted porcine surfactant in mechanically ventilated term infants with severe acute respiratory distress syndrome (ARDS) due to meconium aspiration syndrome (MAS). METHODS: Eight consecutive mechanically ventilated term infants with severe ARDS due to MAS underwent BAL with 15 mL/kg of diluted (5.3mg phospholipid/mL) surfactant saline suspension (porcine surfactant [Curosurf]). Treatment was administered slowly in aliquots of 2.5 mL. The mean age of neonates at treatment was 3.5 (range 1-8) hours. Heart rate, systemic blood pressure and oxygen saturation were monitored continuously. Arterial blood gases were measured immediately before treatment, and again at 3 and 6 hours post-treatment. Chest x-rays were taken 6 and 24 hours after treatment. RESULTS: Radiological improvement was evident in all eight patients 6 hours post-treatment. Compared with pre-BAL values, significant improvements (p < 0.05) in mean values for partial pressure of oxygen in arterial blood, partial pressure of carbon dioxide in arterial blood, pH, arterial/alveolar O2 ratio and oxygenation index were documented at 3 and 6 hours after BAL. In all patients, tracheal fluids that had been meconium-stained prior to BAL were clear of meconium after BAL. Only one patient required nitric oxide therapy for transient pulmonary hypertension. No adverse sequelae of treatment occurred during the study. CONCLUSIONS: BAL with dilute porcine surfactant administered slowly in 2.5 mL aliquots improved oxygenation and chest x-ray findings, without causing major adverse effects, in mechanically ventilated term infants with ARDS due to MAS.

Biological Products↗

PubMed2006

Right congenital diaphragmatic hernia associated with a complex heart disease.

A case of right diaphragmatic hernia is presented associated with a complex congenital heart disease (double-outlet right ventricle, transposition of the great arteries and left isomerism) diagnosed prenatally. Despite high-frequency oscillatory ventilation plus nitric oxide and uneventful repair of the hernia, the infant died after 6 days of uncontrolled pulmonary hypertension and severe aortic coarctation that developed postnatally.

Diagnosis, Differential↗

PubMed2005

Systemic blood pressure profile in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic form of subcortical ischemic vascular dementia (SIVD). The most common vascular risk factors are unremarkable in CADASIL; however, studies on systemic blood pressure (BP) changes over time are substantially lacking. Because BP instability is a relevant risk factor for developing or worsening white matter changes in sporadic SIVD, we aimed to study the BP profile of CADASIL to investigate its relationship with cognitive decline and white matter injury. METHODS: Twenty-four-hour ambulatory BP monitoring was performed in a group of 14 CADASIL patients (12 males and 2 females) and in a group of 15 healthy age-matched control subjects. The following BP variables were compared between the 2 groups: mean daytime and nighttime systolic, diastolic, and mean arterial BP (SABPday, DABPday, and MABPday, and SABPnight, DABPnight, and MABPnight) and nocturnal percentage decline in arterial BP (%MABP reduction). Cognitive performances were tested by mini mental status examination (MMSE), and brain MRI was performed to extrapolate the T2-weighted lesion volume (LV) in each CADASIL patient. The 24-hour arterial BP variables were compared between CADASIL and controls. In addition, for CADASIL patients only, MMSE, LV, and age were compared with each pressure variable. RESULTS: Patients with CADASIL showed a significant reduction (P<0.05) of SABPday, DABPday, MABPday and %MABP decline with respect to controls. In addition, MMSE of CADASIL subjects correlated significantly (P<0.0001) with daytime MABP. CONCLUSIONS: The low systemic BP profile observed in CADASIL patients was specifically attributable to reduced diurnal BP values. This may further affect cerebral hemodynamics and increase the risk of cognitive impairment in these patients. The pathogenesis of abnormal BP profile in CADASIL remains to be clarified. It is likely that central and peripheral mechanisms controlling BP variations are involved.

Adolescent↗

PubMed2005

Peripheral neuropathy in CADASIL.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a hereditary cerebral microangiopathy associated with mutations in the Notch 3 gene. The clinical phenotype is characterized by cerebral impairment even though typical microvascular changes are diffuse. OBJECTIVE: To assess peripheral neuropathy in patients with CADASIL. PATIENTS AND METHODS: We enrolled eleven CADASIL patients with variable phenotype including clinical signs of peripheral nerve involvement. In all patients electromyography and nerve conduction velocities were performed. Peripheral nerve biopsy was performed in three cases. RESULTS: We found sensory motor neuropathy in 7/11 patients. Nerve biopsy revealed axonal and demyelinated findings. CONCLUSION: Our findings suggest that peripheral neuropathy may be part of the CADASIL phenotype.

Action Potentials↗

PubMed2005

Normal birth after transfer of cryopreserved human embryos generated by microinjection of cryopreserved testicular spermatozoa into cryopreserved human oocytes.

OBJECTIVE: To report the first birth after transfer of cryopreserved embryos generated by intracytoplasmic sperm injection of cryopreserved testicular spermatozoa into cryopreserved human oocytes. DESIGN: Case report. SETTING: Tertiary center for reproductive technology. PATIENT(S): A 36-year-old woman with primary infertility of 3 years' duration and a 37-year-old man with congenital bilateral absence of the vas deferens. INTERVENTION(S): Cryopreservation of human embryos after oocytes and sperm thawing. MAIN OUTCOME MEASURE(S): Live birth. RESULT(S): A healthy, normal female infant with a birth weight of 2,950 g was born by cesarean section at 38 weeks' gestation, with normal 6-month follow-up. CONCLUSION(S): Embryo cryopreservation can lead to successful results, even with the use of cryopreserved gametes.

Adult↗

PubMed2004

Acute unilateral visual loss as the first symptom of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND: Although cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is considered a cerebrovascular disorder with almost exclusively neurological symptoms, the arteriopathy is generalized and involves choroidal and retinal vasculature as demonstrated by fluorescein angiographic and ocular electrophysiological abnormalities. The occurrence of acute visual loss due to nonarteritic anterior ischemic optic neuropathy (NAION) has not previously been reported in CADASIL. OBJECTIVE: To describe acute visual loss due to NAION as a possible manifestation of CADASIL. PATIENTS AND METHODS: The patient was a 60-year-old man with subcortical diffuse leukoencephalopathy, multi-infarct dementia, tetraparesis, visual loss, and a family history of stroke. We performed clinical and neuro-ophthalmological evaluation, electrophysiological assessment, brain magnetic resonance imaging, and genetic screening for mutations or small deletions of the Notch3 gene, (causing CADASIL). RESULTS: The patient's first symptom was acute visual loss in the right eye due to NAION at age 27 years, in absence of the common cardiovascular risk factors and before any neurological impairment. The patient was reevaluated at age 60 years, and neuro-ophthalmological examination showed optic disc atrophy in the right eye with arteriolar narrowing and a reduction in visual acuity in the left eye. Fluorescein angiography of the right eye showed evidence of persistent peripapillary hypofluorescence with a retinal pigment epithelial windows defect in the inferior temporal area. Pattern reversal visual evoked potentials were abolished in the right eye. The P100 latency of the left eye was delayed and reduced in amplitude. The diagnosis of CADASIL was confirmed by molecular analysis (heterozygotes for the C406T mutation on exon 3 of the Notch3 gene). There was a family history of cerebrovascular disorders and ocular impairment. CONCLUSIONS: Visual loss due to transient or stable ischemic events involving the optic nerve head should be considered in the CADASIL phenotype. The possibility of CADASIL should also be evaluated in patients with NAION who do not have cardiovascular risk factors but do have a family history of stroke.

Blindness↗

PubMed2004

A novel NOTCH3 frameshift deletion and mitochondrial abnormalities in a patient with CADASIL.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which leads to strokes and dementia, is caused by single missense mutations or, in a few cases, small deletions in the NOTCH3 gene. These mutations result in a gain or a loss of 1 (or, rarely, 3) cysteine residue in 1 of 34 epidermal growth factor-like repeats in the extracellular amino-terminal region of NOTCH3. OBJECTIVE: To describe a patient with a novel NOTCH3 mutation in whom clinical and laboratory findings of mitochondrial abnormalities were associated with a diagnosis of CADASIL. Patient A patient with a history of migraines, repeated transient ischemic attacks, and generalized fatigue underwent muscle biopsy, brain magnetic resonance spectroscopic imaging, and screening of mitochondrial DNA and NOTCH3. RESULTS: Molecular genetic analysis showed a NOTCH3 mutation (the first documented frameshift deletion in a patient with CADASIL) in exon 4. Although the screening of mitochondrial DNA did not show mitochondrial mutations, findings from muscle biopsy and brain magnetic resonance spectroscopic imaging showed signs of mitochondrial impairment (ultrastructural mitochondrial abnormalities and increased parenchymal brain lactate, respectively). CONCLUSIONS: A patient with CADASIL and a 5-base pair deletion leading to a frameshift mutation showed clinical and laboratory evidence of mitochondrial dysfunction. This adds to the previously reported hypothesis of a pathogenetic role of NOTCH3 or, less specifically, a microvascular pathologic effect on mitochondrial energy metabolism.

Base Sequence↗

PubMed2003

Primary prevention of hepatitis C virus infection.

Viral hepatitis type C is a worldwide public health problem of major concern. Waiting for a safe and effective vaccine able to confer protection to susceptible individuals, public health challenges for controlling hepatitis C require implementation of primary prevention measures that reduce risks of acquiring/transmitting HCV infection. Screening for safe blood and blood products, use of disposable syringes and needles and of universal precautions have dramatically reduced risk of infection in medical setting. Health education, counselling and testing of individuals at risk provide opportunities for controlling HCV infection.

Global Health↗

PubMed2003

Cryopreservation of a small number of spermatozoa in yolk-filled human zonae pellucidae.

OBJECTIVES: Conventional sperm freezing procedures need the addition of a relatively large volume of cryoprotectant. The dilution of extremely poor sperm suspensions from ejaculate or testicular tissue may make the recovery of viable spermatozoa difficult at the moment of the intracytoplasmic sperm injection (ICSI) procedure. The cryopreservation of a few spermatozoa in empty zonae pellucidae is an interesting solution for crypto-azoospermic infertile men. We have modified this procedure by filling empty human zonae with TEST Yolk Buffer, an optimal cryoprotective medium, in order to analyse the number of zonae lost after thawing, the number of recovered spermatozoa per zona after thawing, and the sperm motility rate before freezing and after thawing. MATERIALS AND METHODS: Fifty empty human zonae pellucidae previously filled with TEST Yolk Buffer were injected with 750 motile spermatozoa from ten infertile men (15 spermatozoa per zona). Sterile straws containing two zonae each were frozen following a two-phase protocol. RESULTS: All of the zonae and 445/750 spermatozoa (59%) were recovered. The mean number (+ SD) of spermatozoa per zona was 8.9 +/- 1.9 (range: 5-12). The recovery rate of motile spermatozoa was 73% (327/445), with a mean number of motile spermatozoa per zona of 6.5 +/- 1.7 (range: 3-10). CONCLUSIONS: The cryopreservation of a small number of motile spermatozoa within empty zonae pellucidae using TEST Yolk Buffer as a freezing medium is possible without any major loss of spermatozoa and with an appreciable maintenance of sperm motility. This procedure seems to avoid: i) uncertain sperm retrieval after a laborious and time-consuming search on the day of oocyte aspiration; ii) the need for a repeated testicular biopsy; and iii) the need for heterologous insemination or oocyte cryopreservation (11).

Buffers↗