Biomedical subjects

S Bernardini

Publications and source records attributed to S Bernardini.

At least 37 records · Page 2Linked to original sources

PubMed2001

Collagen VII expression in glomerular sclerosis.

Glomerular sclerosis is the final stage of a variety of kidney diseases and matrix molecules not normally expressed in the extracellular matrix are synthesized and accumulate during the sclerotic process. Collagen type VII is the major component of the anchoring fibrils at the dermal-epidermal junction, but it is usually not present in normal glomeruli. The aim of this study was to investigate whether this type of fibrillary collagen, different from types I and III, is expressed in chronically diseased glomerular extracellular matrix. The presence and distribution of collagen VII have been examined in 50 renal biopsies by indirect immunofluorescence staining, standard electron microscopy, and immuno-electron microscopy. In selected cases, collagen VII mRNA expression was also measured by RT-PCR on isolated glomeruli. Cases included focal segmental glomerulosclerosis, minimal change disease, membranous glomerulonephritis, IgA nephropathy, SLE nephritis, diabetic glomerulosclerosis, ischaemic renal disease, extracapillary glomerulonephritis, and end-stage renal disease. Collagen VII protein and mRNA expression was absent or present in trace amounts in normal kidneys or in disorders with only a mild increase of mesangial matrix, without scarring of the tuft. Maximal expression was evident in the presence of adhesions between the glomerular tuft and Bowman's capsule or fibrous crescents. The results showed that collagen VII is actively synthesized and laid down in areas of glomerular and/or tubular scarring, irrespective of the underlying disease, confirming the de novo expression of fibrillary collagens in diseased renal extracellular matrix. The appearance of an anchoring collagen may be a response to support mechanical stress and it takes part in the process of cell proliferation and tissue repair.

Case-Control Studies↗

PubMed2001

Proton magnetic resonance spectroscopy (1H-MRS) of motor cortex and basal ganglia in de novo Parkinson's disease patients.

Proton MR spectroscopy (1H-MRS) has been previously performed in Parkinson's disease (PD) and parkinsonian syndromes to evaluate in vivo concentrations of basal ganglia and cerebral cortex metabolites such as N-acetylaspartate (NAA), choline (Cho), and creatine (Cr). However, this technique has never been used to evaluate motor cortex in untreated PD patients. In this study, single-voxel 1H-MRS of basal ganglia and motor cortex was carried out in 10 de novo patients with PD and 10 age-matched healthy controls. A significant reduction in the NAA/Cr ratio was observed in the motor cortex of PD patients compared with controls (p)<(0.01). Basal ganglia spectra did not allow any evaluation due to the presence of artefacts related to inorganic paramagnetic substances. The motor cortex reduction of the NAA/Cr ratio in de novo PD patients may reflect an altered neuronal functioning due to a loss of thalamocortical excitatory inputs and may represent an in vivo marker for the diagnosis of PD.

Aged↗

PubMed2001

Cytogenetic analysis oxidative damage in lymphocytes of Parkinson's disease patients.

Several lines of evidence support the presence of DNA damage in somatic cells of Parkinson's disease (PD) patients due to the formation of free radical species. In order to detect spontaneous chromosome and primary or oxidative DNA damage, we performed the human lymphocyte micronucleus assay (HLMNA) and comet assay in 19 PD patients and 16 healthy controls. Compared with controls, PD patients showed a significant increase in: (I) spontaneous micronucleus (MN) frequency (p<0.001); (2) single strand break (SSB) levels (p<0.001); and (3) oxidized purine base levels (p<0.05). The chromosome damage and the increased levels of oxidized purine bases observed in our patients support the hypothesis of oxidative stress as a relevant factor in the pathogenesis of PD.

Aged↗

PubMed2001

A multiplex PCR-based DNA assay for the detection of paraoxonase gene cluster polymorphisms.

Paraoxonase (PON) is a high-density lipoprotein (HDL) associated protein which is supposed to protect low-density lipoprotein (LDL) against oxidation and to play a role in the development of atherosclerosis. Interindividual variability in serum PON activity is attributable to common variants in components of the PON gene cluster on chromosome 7. We describe experimental conditions that permit the simultaneous determination of three common PON polymorphisms (PON1-192, PON1-55 and PON2-311) that are tightly associated with an increased risk of atherosclerosis. We used a multiplex PCR-based DNA assay using mismatch primers that introduce a unique recognition site for the endonuclease HinfI in the PCR products in case of presence of the R allele of PON 1-192, of the L allele of PON1-55 and of the S allele of PON2-311. The restriction analysis with HinfI allows to identify an electrophoretic band pattern which is specific for the combination of the three polymorphisms. This technique could be applied in the association studies aimed at assessing the role of PON and their polymorphisms in many clinical settings. In a preliminary study on a small population sample from south Italy about 10% of chromosomes exhibited the presumed risk-related haplotype R(192)/L(55)/S(311).

Alleles↗

PubMed2001

Protein kinase C signalling pathway is involved in the regulation of vascular endothelial growth factor expression in human bladder transitional carcinoma cells.

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor associated with the growth and metastasis of various cancers and plays a prominent role in vesical angiogenesis regulation. In this study, we investigated the effect of the phorbol 12-myristate 13-acetate (PMA) on the expression of VEGF in human bladder transitional carcinoma cells (RT4). RT4 cells expressed three VEGF isoforms (VEGF(189), VEGF(165), VEGF(121)). PMA increased VEGF mRNA expression time-dependently with a peak at 4 h. PMA increased the half-life of VEGF mRNA. The amount of VEGF protein in conditioned media was increased by PMA in a dose-dependent manner with a maximal effect at 10(-7) M. Staurosporine and calphostin C (PKC inhibitors) decreased PMA-induced VEGF mRNA expression as opposed to protein kinase A or cyclic nucleotide-dependent protein kinase inhibitors. Thus, in RT4 cells, VEGF expression is up-regulated by PMA via the PKC signalling pathway and according to a posttranscriptional mechanism.

Carcinoma, Transitional Cell↗

PubMed2001

Trans-stilbene oxide-induced sister chromatid exchange in cultured human lymphocytes: influence of GSTM1 and GSTT1 genotypes.

About 50% and 15% of Caucasians lack the glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) genes and the corresponding enzyme activity, respectively. Both of these polymorphisms have been shown to affect the genotoxicity of some epoxides in cultured human lymphocytes. Especially GSTT1 appears to be important in whole-blood cultures, probably because GSTT1 activity is high in erythrocytes. The in vitro genotoxicity of trans-stilbene oxide (TSO), a model substrate for GSTM1, has been shown to depend on individual GSTM1 activity. The potential role of GSTM1 genotype, and the possible interference of GSTT1 genotype, has not previously been examined in this context. We have studied TSO-induced sister chromatid exchanges (SCEs) in 72 h whole-blood lymphocyte cultures from 24 healthy human donors, representing different combinations of GSTM1 and GSTT1 positive and null genotypes. TSO clearly increased SCEs in cultures of all donors. The mean number of SCEs per cell induced by 75 and 150 microM TSO was, respectively, 1.5- and 1.3-times higher in cultures of GSTM1 null than GSTM1 positive donors. In another experiment, GSTM1 null individuals showed, in comparison with GSTM1 positive subjects, a 1.8-fold SCE induction by 50 microM TSO. GSTT1 genotype did not have an unequivocal effect. Our findings suggest that the lack of the GSTM1 gene, resulting in reduced detoxification capacity, increases individual sensitivity to the genotoxic effects of TSO.

Adult↗

PubMed2001

The predictive value of muscularis mucosae invasion and p53 over expression on progression of stage T1 bladder carcinoma.

PURPOSE: We determine the significance of muscularis mucosae invasion and nuclear p53 over expression on the progression of stage T1 transitional cell bladder cancer. MATERIALS AND METHODS: The pathological findings in 149 cases of T1 tumors diagnosed between 1973 and 1996 were reviewed. Diagnosis was stage T1 in 94 tumors in which the muscular layer was clearly identifiable and disease-free. Mean followup was 64.9 months (range 5 to 288). T1 bladder cancers were subclassified into 2 groups, with (T1b) or without (T1a) muscularis mucosae invasion. The p53 nuclear antibody immunoreactivity was determined with antibody D07 and a cutoff point at 15%. RESULTS: T1 subclassification was possible in all 94 patients. Of all tumors 37.2% expressed p53 nuclear over expression. Univariate statistical analysis showed that p53 expression (p <0.05) and tumor invasion depth (p <0.001) significantly correlated with progression. However, on multivariate analysis only invasion depth (p <0.0001) and associated carcinoma in situ (p <0.03) remained independently significant as predictors of progression. CONCLUSIONS: In our study the depth of tumor invasion was a significant independent predictor of progression in patients with T1 bladder cancer. This result suggests that the depth of invasion in stage T1 should be included in the histopathological report.

Aged↗

PubMed2001

Effects of cisapride on QTc interval in term neonates.

BACKGROUND: Cisapride administration for 48 hours has been shown to increase heart rate corrected QT (QTc) interval in preterm neonates. Accumulation of the drug because of liver enzyme immaturity has been suggested to be the reason. If this is correct, a longer survey of QTc interval should disclose an increase even in term neonates. OBJECTIVE: A prospective survey of the effects of cisapride on QTc interval in term neonates administered cisapride. SETTING: Neonatal Unit of the University Hospital of Dijon, France. DESIGN: QTc interval was determined just before and 48 hours, seven days, and 15 days after the start of treatment. SUBJECTS: Twenty one term newborn infants (mean gestational age 39.3 weeks) given the recommended dose of cisapride (0.2 mg/kg, four times a day). RESULTS: Administration of cisapride caused a significant increase in QTc interval (p < 0. 01). The mean value increased from 0.397 before treatment to 0.418 after 48 hours, 0.431 by day 7, and 0.447 by day 15. A QTc interval exceeding 0.450 was found in six neonates: three at 48 hours, one at day 7, and two at day 15. In two infants, withdrawal of the drug was associated with normalisation of the QTc interval. CONCLUSIONS: These results support the hypothesis of cisapride accumulation in newborns due to enzymatic immaturity and indicate that QTc interval should be monitored in neonates receiving this drug.

Analysis of Variance↗

PubMed2001

Glutathione transferase P1 polymorphism in neuroblastoma studied by endonuclease restriction mapping.

Several members of the different glutathione transferase (GST) gene classes are polymorphic. Particular interest has been focused on the GSTP class because this gene class is up-regulated during the early stage of oncogenesis and is significantly overexpressed in many human tumors. It has also been shown that high levels of GSTP1 expression are associated directly with tumor drug resistance and with poor patient survival. Our aim was to understand the possible association between GSTP1 polymorphism and cellular response to chemotherapeutic drugs in neuroblastoma. In fact, several antineoplastic drugs used in the neuroblastoma high-risk chemotherapeutic protocol are potential substrates of GSTP1-1 (etoposide, adriamycin and carboplatin). The GSTP1 genotype homozygote *A/*A was identified in 11 patients independent of their response to the chemotherapeutic treatment. Only four patients had a heterozygote genotype A*/B*. Therefore, based on our preliminary data, we were not able to conclude that GSTP1 polymorphism had an impact on patient response to treatment in neuroblastoma.

Adolescent↗

PubMed2001

[Spontaneous thrombosis of left varicocele].

Spontaneous thrombosis of a varicocele is a rare event and difficult to diagnose, as the clinical symptoms during the acute phase can simulate torsion of the spermatic cord or strangulated inguinal hernia leading to a useless surgical exploration. The authors report a case of spontaneous thrombosis of a varicocele which was diagnosed clinically, allowing conservative medical treatment.

Adult↗

PubMed2001

[Usefulness of p53 in the clinical management of bladder tumors].

The antioncogene p53 has been the subject of many studies in the field of bladder cancer, for many years and there appears to be a good correlation between p53 protein overexpression and pejorative clinicopathological factors, but contradictory results have been reported concerning its prognostic value. These discordances can be partly explained by the various immunohistochemical methods used in published series. Standardization of a highly sensitive and specific immunohistochemical method for the detection of p53 alterations now appears to be essential in order to accurately determine the value of p53 in the clinical management of bladder cancer.

Autoantibodies↗

PubMed2001

[Angiogenesis in bladder: prognosis indicator and therapeutic target].

Angiogenesis is a complex, multi-step process which leads to the formation of new blood capillaries (neovessels) from preexisting vessels. It is essential top the growth of solid tumours and tumour metastasis (tumour angiogenesis). This process is initiated by the synthesis, by tumour cells and non-malignant tumour-associated cells, of growth factors called antigenic factors or inducers. bFGF (basic Fibroblast Growth Factor) and VEGF (Vascular Endothelial Growth Factor) are the two angiogenic factors involved in bladder tumour angiogenesis. The angiogenic activity of a bladder tumour can be measured by the microvascular density (MVD), considered by some authors to be an independent prognostic indicator of recurrence and survival in the group of invasive bladder tumours. VEGF expression in bladder tumours and biological fluids (serum, urine) appears to be a predictive marker of the risk of progression of superficial bladder tumours. Urinary bFGF assay reveals high levels in patients with bladder tumour, but this elevation is not specific to bladder tumours. Inhibition of tumour angiogenesis has become a therapeutic target. Intravesical suramine and a fumagillin analogue (TNP-470) have given promising results in terms of efficacy and safety in the treatment of bladder tumours.

Endothelial Growth Factors↗

PubMed2001

[Testicular trauma: report of 56 cases].

OBJECTIVES: To assess the diagnostic value of clinical examination and ultrasound in testicular trauma and to analyse the complications of the various treatments proposed (surgical and medical treatments), in order to more clearly define the place of medical treatment in this form of trauma in young adults. PATIENTS AND METHODS: 56 cases of testicular trauma in 50 patients were managed between January 1990 and January 2000. In the absence of clinical and ultrasonographic criteria of severity (haematocele, very large intratesticular haematoma, rupture of the tunica albuginea), medical treatment consisting of rest, anti-inflammatory drugs, and testicular support was instituted. Surgical exploration was performed when serious lesions of the testis were suspected. Three subgroup were defined: the medical treatment subgroup, the early surgical treatment subgroup, and the deferred surgical treatment subgroup (more than 3 days after trauma). The immediate morbidity and long-term sequelae were analysed in each of these three subgroups. RESULTS: The clinical features of pain and scrotal swelling make assessment of the lesions difficult. Testicular ultrasound can help the clinician, but it has a low sensitivity for the diagnosis of testicular rupture. No significant difference was observed between the three subgroups in terms of morbidity, orchidectomy, and long-term sequelae rates. CONCLUSION: In the absence of signs of severity, medical treatment with regular surveillance remains justified. However, in the case of doubtful clinical or ultrasound findings, surgical exploration must be performed as soon as possible.

Adolescent↗

PubMed2001

Serum levels of vascular endothelial growth factor as a prognostic factor in bladder cancer.

PURPOSE: Vascular endothelial growth factor is an overriding growth factor mediating tumor angiogenesis. We correlated serum vascular endothelial growth factor in patients with bladder cancer with clinical parameters. MATERIALS AND METHODS: Serum vascular endothelial growth factor in 58 patients with bladder cancer, including superficial and invasive tumors in 42 and 16, respectively, and 41 healthy controls was measured by sandwich enzyme immunoassay. RESULTS: Significant differences in serum vascular endothelial growth factor were observed in healthy controls and patients with bladder cancer (mean 248 versus 100 pg./ml., p <0.001). The serum level was significantly associated with tumor stage (p <0.0001), grade (p <0.002), vascular invasion (p <0.001) and carcinoma in situ (p <0.01). Patients with metastasis had a significantly higher levels than those with localized diseases (mean 582 versus 194 pg./ml., p <0.0001). At a cut-off of 400 pg./ml. the sensitivity and specificity of the test for differentiating patients with and without metastatic diseases was 87.5% and 98%, respectively (p <0.0001). Univariate statistical analysis showed that an increase in serum vascular endothelial growth factor level greater than 400 pg./ml. was significantly related to disease-free survival. On multivariate analysis only stage remained as an independent prognostic factor. CONCLUSIONS: Although vascular endothelial growth factor did not remain an independent prognostic factor on multivariate analysis, our data indicate that the level of vascular endothelial growth factor may be a valuable angiogenic marker for identifying metastatic bladder cancer. It may be used as a new predictor of disease.

Adult↗

PubMed2000

Decreased c-Src expression enhances osteoblast differentiation and bone formation.

c-src deletion in mice leads to osteopetrosis as a result of reduced bone resorption due to an alteration of the osteoclast. We report that deletion/reduction of Src expression enhances osteoblast differentiation and bone formation, contributing to the increase in bone mass. Bone histomorphometry showed that bone formation was increased in Src null compared with wild-type mice. In vitro, alkaline phosphatase (ALP) activity and nodule mineralization were increased in primary calvarial cells and in SV40-immortalized osteoblasts from Src(-/-) relative to Src(+/+) mice. Src-antisense oligodeoxynucleotides (AS-src) reduced Src levels by approximately 60% and caused a similar increase in ALP activity and nodule mineralization in primary osteoblasts in vitro. Reduction in cell proliferation was observed in primary and immortalized Src(-/-) osteoblasts and in normal osteoblasts incubated with the AS-src. Semiquantitative reverse transcriptase-PCR revealed upregulation of ALP, Osf2/Cbfa1 transcription factor, PTH/PTHrP receptor, osteocalcin, and pro-alpha 2(I) collagen in Src-deficient osteoblasts. The expression of the bone matrix protein osteopontin remained unchanged. Based on these results, we conclude that the reduction of Src expression not only inhibits bone resorption, but also stimulates osteoblast differentiation and bone formation, suggesting that the osteogenic cells may contribute to the development of the osteopetrotic phenotype in Src-deficient mice.

Alkaline Phosphatase↗

PubMed2000

Genetic variation in human stromelysin gene promoter and common carotid geometry in healthy male subjects.

A common variant in the promoter of the human stromelysin gene, causing reduced enzyme expression, has been associated with the progression of coronary atherosclerosis. On the other hand, increased stromelysin activity may promote plaque rupture. The present study was undertaken to investigate the relationship between the genetic variation in the human stromelysin gene promoter and common carotid geometry. Forty-two healthy male subjects without major coronary heart disease risk factors were investigated. The polymorphism in the stromelysin gene promoter was studied through polymerase chain reaction amplification with the use of mutagenic primers. Age, blood pressure, lipids, glucose, viscosity, and body mass index were similar in homozygotes for the 5A allele (5A/5A), heterozygotes (5A/6A), and homozygotes for the 6A allele (6A/6A). Serum matrix metalloproteinase-3 levels did not differ significantly among genotypes. Common carotid diameters and intima-media thickness, measured by noninvasive ultrasonography, were significantly larger in 6A/6A subjects (for respective 6A/6A, 5A/6A, and 5A/5A subjects, diameter at the R wave was 0.63+/-0.09, 0.55+/-0.06, and 0.53+/-0.04 cm [mean+/-SD], P<0.005 by ANOVA; intima-media thickness was 765+/-116, 670+/-116, and 630+/-92 microm [mean+/-SD], P<0.05 by ANOVA). Wall shear stress, calculated as blood velocityxblood viscosity/internal diameter, was significantly lower in 6A/6A subjects (for respective 6A/6A, 5A/6A, and 5A/5A subjects, mean wall shear stress was 10.4+/-2.9, 13.5+/-3.5, and 12.6+/-1.9 dyne/cm(2) [mean+/-SD], P<0.05 by ANOVA). The results demonstrate that the gene polymorphism in the promoter region of stromelysin is associated with structural and functional characteristics of the common carotid artery in healthy male subjects without major risk factors for atherosclerosis. Individuals with the 6A/6A genotype (associated with lower enzyme activity) show a triad of events, namely, increased wall thickness, enlarged arterial lumen, and local reduction of wall shear stress, which might predispose them to atherosclerotic plaque localization.

Adult↗

PubMed2000

Modulation of GST P1-1 activity by polymerization during apoptosis.

Glutathione S-transferases (GSTs, EC 2.5.1.18) belong to a large family of functionally different enzymes that catalyze the S-conjugation of glutathione with a wide variety of electrophilic compounds including carcinogens and anticancer drugs. Drug resistance may result from reduction in apoptosis of neoplastic cells when exposed to antineoplastic drugs. The c-Jun N-terminal Kinase (JNK) belongs to the family of stress kinases and has been shown to be required for the maximal induction of apoptosis by DNA-damaging agents. Recently, an inhibition of JNK activity by GST P1-1, which was reversed by polymerization induced by oxidative stress, has been reported in 3T3-4A mouse fibroblast cell lines. The finding that GST P1-1 might inhibit JNK activity and that it is frequently highly expressed in tumor tissues suggests its possible implication in "apoptosis resistance" during antineoplastic therapy. We investigated the modulation of GST P1-1 during apoptosis in a neoplastic T-cell line (Jurkat) induced by hydrogen peroxide and etoposide. Apoptosis was paralleled by the appearance of a dimeric form of GST P1-1 on western blotting, associated with an increase in the Km(GSH) and a reduction in GST P1-1 specific activity toward 1-chloro-2,4-dinitrobenzene, which reached statistical significance only in H(2)O(2)-treated cells. Our data seem to suggest that H(2)O(2) and etoposide may partly act through a process of partial inactivation of the GST P1-1, possibly involving the "G" site in the process of dimerization, and thus favoring programmed cell death.

Apoptosis↗

PubMed2000

[Malignant penile melanoma].

The authors report the case of a very large, obstructive malignant melanoma (MM.) of the prepuce, encasing all of the distal extremity of the penis, and discovered at a late metastatic stage (regional lymph node metastasis). Palliative treatment, consisting of partial penectomy associated with a complementary induction and maintenance chemotherapy did not achieve any objective response at one year. MM. of the penis are rare urological tumours, including MM of the penis and MM of the male urethra (exclusively mucosal involvement). The diagnosis of MM of the penis must be considered in any case of black or brown lesion of the glans, which is the most frequent site. The prognosis is determined by the clinical stage (BRACKEN and DIOKNO classification) and by the depth and level of tumour invasion (BRESLOW index and CLARK's degree of dermal invasion). The 5-year survival is inversely proportional to the tumour thickness. The treatment of MM of the penis is surgical; the extent of resection and the indication for lymph node dissection depend on the patient's age, sexuality, and the stage of the disease and depth of tumour invasion.

Humans↗