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Biomedical subjects

S Rossi

Publications and source records attributed to S Rossi.

At least 199 records · Page 11Linked to original sources
PubMed1998

pQCT (quantitative peripheral tomography) and data evaluation of phosphocalcic metabolism in thalassaemic patients.

pQCT is a method which allows the separate determination of cortical and trabecular bone mineral density in the peripheral skeleton. 21 thalassaemic patients (8 females, 13 males) aged from 10 to 32 years, were examined using pQCT at the ultra distal radius to evaluate SSI (Stress-Strain Index). ALP, serum calcium, hydroxyproline, magnesium, IGF-I, and body surface were determined. The results show a good correlation between cortical BMD and age, concentration of hydroxyproline in urine, serum bone Gla protein, body surface index, bone density of trabecular bone and SSI. Good correlation was found between trabecular bone density and age, IGF-I, BGP and PTH, and between SSI and cortical BMD, age and BSI. The linear relationships between age and cortical and trabecular density show an increase of cortical BMD with age and a decrease of trabecular density with age. The same results were obtained considering trabecular and cortical density versus SSI.

Adolescent↗
PubMed1998

[Monitoring and protection of the central nervous system in subarachnoid hemorrhage during intensive care].

Subarachnoid hemorrhage has cerebral and systemic consequences as well. The main purpose of admitting a patient in the Intensive Care setting is to provide protection, mainly by stabilizing fundamental physiological parameters. There are both systemic parameters and cerebral parameters to be controlled continuously, and cerebral parameters may consider the brain as a whole (global cerebral parameters as intracranial pressure) or may provide information on specific areas. Cerebral protection may be achieved only when multiparametric monitoring is instituted, since only the combination of many physiologic parameters provides information capable of identifying, and hopefully of treating, deleterious derangements.

Central Nervous System↗
PubMed1998

High prevalence of peripheral neuropathy in hepatitis C virus infected patients with symptomatic and asymptomatic cryoglobulinaemia.

BACKGROUND: Fifty per cent of patients with chronic hepatitis C, show detectable cryoglobulinaemia, even though most of them do not show cryoglobulinaemia related symptoms. Peripheral neuropathy is present in most of the patients with symptomatic cryoglobulinaemia, where it may be the first clinical manifestation. The prevalence of peripheral neuropathy in patients with hepatitis C and cryoglobulinaemia is unknown. AIMS: To assess the prevalence of peripheral neuropathy in HCV infected patients with symptomatic or asymptomatic detectable cryoglobulinaemia. PATIENTS AND METHODS: Eighty-nine patients with HCV infection and detectable cryoglobulinaemia underwent electrophysiological studies. RESULTS: Electrophysiological evidence of peripheral neuropathy was found in 37% and was significantly associated with: the presence of cryoglobulinaemia syndrome, older age, higher rheumatoid factor reactivity and immunoglobulin M levels and reduced complement C4 activity. However, electrophysiological evidence of peripheral neuropathy was unrelated to cryocrit levels and type of cryoglobulinaemia and was found in 23/68 patients without any symptoms of cryoglobulinaemia other than pain and paresthesia. CONCLUSIONS: These findings suggest that peripheral neuropathy is frequent in patients with hepatitis C and detectable cryoglobulins. Neuropathy was found to be present in 1/3 of patients without other cryoglobulinaemia-related symptoms, thus a direct or indirect role of HCV, independent of cryoglobulinaemia, in the pathogenesis of nerve damage cannot be ruled out.

Age Factors↗
PubMed1997

Hepatitis C virus genotypes and risk of hepatocellular carcinoma in cirrhosis: a prospective study.

A prospective study was performed to establish whether infection with specific hepatitis C virus (HCV) genotypes was associated with an increased risk of development of hepatocellular carcinoma (HCC) in cirrhosis. A cohort of 163 consecutive hepatitis C virus antibody (anti-HCV)-positive cirrhotic patients was prospectively evaluated for the development of HCC at 6-month intervals by ultrasound (US) scan and alpha-fetoprotein (AFP) concentration. HCV genotypes were determined according to Okamoto. Risk factors associated with cancer development were analyzed by univariate and multivariate statistics. At enrollment, 101 patients (62%) were infected with type 1b, 48 (29.5%) were infected with type 2a/c, 2 (1.2%) were infected with type 3a, 1 (0.6%) was infected with type 1a, 3 (1.8%) had a mixed-type infection, and, in 8 patients (4.9%), genotype could not be assigned. After a 5- to 7-year follow-up (median, 68 months), HCC developed in 22 of the patients, 19 infected with type 1b and 3 with type 2a/c (P < .005). Moreover, HCC developed more frequently in males (P < .01), patients with excessive alcohol intake (P < .01), those over 60 years of age (P < .02), and in patients who did not receive interferon treatment (P < .02). Multivariate analysis showed that type 1b was the most important risk factor associated with tumor development (odds ratio 6.14, 1.77-21.37 95% confidence interval). Other independent risk factors were older age and male sex. Cirrhotic patients infected with HCV type 1b carry a significantly higher risk of developing HCC than patients infected by other HCV types. The latter may require a less intensive clinical surveillance for the early detection of neoplasia.

Adult↗
PubMed1997

[Prognostic factors in differentiated thyroid gland carcinoma].

This review aims at describing the influence of established and not yet sufficiently characterized parameters on the prognosis of thyroid follicle cell carcinomas. The analysis of literature data covers a broad spectrum of pathologic and biologic factors from classical prognostic features like age, gender and tumor stage to mutation, activation or, where applicable, inactivation of tumor suppressor genes, metastasis-related genes and adhesion molecules.

Adenocarcinoma, Follicular↗
PubMed1997

Quantitative analysis of hepatitis C virus activity in vivo in different groups of untreated patients.

Highly sensitive competitive PCR (cPCR) and competitive reverse transcription PCR (cRT-PCR) methodologies were recently developed and applied for quantifying viral DNA and RNA species (including HCV RNA) present in clinical samples at low concentration. In this study, we used cRT-PCR to compare the viral load of 118 untreated patients with HCV infection and different clinical conditions (80 patients with chronic hepatitis, 18 infected subjects with persistently normal ALT levels and various degrees of liver injury, 10 HCV infected subjects that tested positive for anti-LKM1 antibodies, and 10 patients with HCV infection and cryoglobulinemia). The results indicate that while great individual variability of HCV viremia is detectable even among patients with similar clinical conditions, the mean HCV RNA copy number in samples from patients with different clinical conditions was similar in all groups with the single exception of patients that tested positive for anti-liver-kidney microsomal auto-antibodies type 1 (anti-LKM1); interestingly, lower HCV viremia levels were revealed in these anti-LKM1-positive cases with liver disease of uncertain pathogenesis.

Gene Dosage↗
PubMed1997

[Nasal surfactant: biochemical and histological study].

The existence of a Surface Tension Lower Substance (STLS) in the lung and the Eustachian tube was established a few decades ago. The histological and physiological characteristics of the epithelium of the whole respiratory tract, from the nasal cavities to rhinopharynx and bronchiolar segments, induced the Authors to search for such a similar substance also in nasal secretion. To this purpose nasal secretions were studied using High Pressure Liquid Chromatography (HPLC) to determine the presence of phospholipids. In addition, ultrastructural examination of the nasal mucosa was performed looking for lamellar body-like structures of 2nd degree pulmonary cells.

Humans↗
PubMed1997

Hepatic vascular malformations in hereditary hemorrhagic telangiectasia: Doppler sonographic screening in a large family.

BACKGROUND/AIMS: The prevalence of hepatic vascular malformations in hereditary hemorrhagic telangiectasia has been estimated in the literature on clinical criteria, thus giving unreliable data. In our study the presence of hepatic vascular malformations in hereditary hemorrhagic telangiectasia was evaluated in a large Italian family by using Doppler sonography findings were compared to computed tomography and angiography results. Clinical features were related to the severity of hepatic vascular malformations. METHODS: Seventy-three relatives were checked for the presence of signs of hereditary hemorrhagic telangiectasia. Abdominal Doppler ultrasonography was performed in all of them. Every subject with a positive Doppler ultrasonography for hepatic vascular malformations underwent abdominal computed tomography and celiac angiography. RESULTS: Forty family members proved to be affected by hereditary hemorrhagic telangiectasia. Of these, hepatic vascular malformations were evidenced by Doppler ultrasonography in 13 females. Doppler ultrasongraphy demonstrated minimal hepatic vascular abnormalities in three subjects, moderate in three, and severe in seven. Doppler study was diagnostic for arteriovenous shunt with hepatic veins in seven cases and with portal vein in two. Computed tomography failed to demonstrate hepatic vascular malformations in two cases, while angiography confirmed the Doppler sonographic findings in all cases. Cholestasis was present in subjects with moderate and severe hepatic vascular malformations. CONCLUSIONS: Doppler sonography is the ideal imaging technique to screen hereditary hemorrhagic telangiectasia affected families for hepatic vascular malformations. These malformations do not appear to be age-dependent, but sex-dependent. Cholestasis is the main clinical sign, and it seems to correlate with the severity of hepatic vascular derangement.

Adolescent↗
PubMed1997

The bereitschaftspotential paradigm in investigating voluntary movement organization in humans using magnetoencephalography (MEG).

In 1965, Kornhuber and Deecke first described the bereitschaftspotential (BP), a paradigm for investigating the organization of voluntary movement in humans, using electroencephalography (EEG). This paradigm has since been used in many studies for investigating motor control in healthy humans and patients. Over the last years, the advantages of magnetoencephalography (MEG) have been applied to the BP paradigm by a number of researchers. The main advantage of magnetoencephalography over electroencephalography is that MEG has a higher localization accuracy. This is due to the fact that the different structures of the head (brain, liquor cerebrospinalis, skull and scalp) influence the magnetic fields less than the volume current flow that causes the EEG. Additionally, the MEG is reference free, so that the localization of sources with a given precision is easier for MEG than it is for EEG. The present protocol shows in detail how the bereitschaftspotential paradigm can be applied using MEG. Some additional paradigms for investigating motor plasticity, somatosensory gating, Parkinson disease, and the efference copy theory are suggested as well.

Adult↗
PubMed1997

Technology for Radiofrequency Thermal Ablation of Liver Tumors.

In this review the usefulness of percutaneous radiofrequency interstitial thermal ablation of liver cancer has been evaluated. The technique has been recently improved by using modified needle electrodes (eg, expandable needle, cooled needle) that allow the ablation of tumors of less than 3.5 cm in diameter in only one session. Tumor necrosis has been shown by imaging techniques such as dynamic or spiral CT, MRI, selective hepatic angiography, ultrasonography-guided fine needle biopsy, and pathologic studies. Both in hepatocellular carcinoma and liver metastases, a complete necrosis has been obtained in more than 80% of the cases. The complication rate has been low without any mortality. In a series of hepatocellular carcinoma followed for a mean time of 23 months, median survival time has been 44 months, whereas recurrence rate was similar to that observed after surgery or ethanol injection. In two small series of metastases, the percentage of disease-free survivors at 1 year ranged from 11 to 66%. In conclusion, radiofrequency interstitial thermal ablation is a safe and effective technique for ablation of liver tumor; however, its precise role in the treatment of liver metastases needs to be defined.

Journal Article↗
PubMed1997

Two mosaic-YY males carrying asymmetric Y chromosomes.

Two patients were referred because of oligospermia and azospermia, respectively. Karyotypic analysis revealed two mosaic-YY males carrying asymmetric Y chromosomes. To our knowledge, no instance of double unequal Y chromosomes has been reported so far in human males. Results of fluorescent in situ hybridization (FISH) studies in spermatozoa from one of these patients revealed a significantly high number of hyperaploid spermatozoa.

Adult↗
PubMed1997

Intracranial pressure dynamics in patients with acute brain damage.

The time pattern of intracranial pressure (ICP) during pressure-volume index (PVI) tests was analyzed in 20 patients with severe acute brain damage by means of a simple mathematical model. In most cases, a satisfactory fitting between model response and patient data was achieved by adjusting only four parameters: the cerebrospinal fluid (CSF) outflow resistance, the intracranial elastance coefficient, and the gain and time constant of cerebral autoregulation. The correlation between the parameter estimates was also analyzed to elucidate the main mechanisms responsible for ICP changes in each patient. Starting from information on the estimated parameter values and their correlation, the patients were classified into two main classes: those with weak autoregulation (8 of 20 patients) and those with strong autoregulation (12 of 20 patients). In the first group of patients, ICP mainly reflects CSF circulation and passive cerebral blood volume changes. In the second group, ICP exhibits paradoxical responses attributable to active changes in cerebral blood volume. Moreover, in two patients of the second group, the time constant of autoregulation is significantly increased (>40 s). The correlation between the parameter estimates was significantly different in the two groups of patients, suggesting the existence of different mechanisms responsible for ICP changes. Moreover, analysis of the correlation between the parameter estimates might give information on the directions of parameter changes that have a greater impact on ICP.

Acute Disease↗