Biomedical subjects

M De Rosa

Publications and source records attributed to M De Rosa.

At least 37 records · Page 2Linked to original sources

PubMed2000

Identification and molecular characterization of the first alpha -xylosidase from an archaeon.

We here report the first molecular characterization of an alpha-xylosidase (XylS) from an Archaeon. Sulfolobus solfataricus is able to grow at temperatures higher than 80 degrees C on several carbohydrates at acidic pH. The isolated xylS gene encodes a monomeric enzyme homologous to alpha-glucosidases, alpha-xylosidases, glucoamylases and sucrase-isomaltases of the glycosyl hydrolase family 31. xylS belongs to a cluster of four genes in the S. solfataricus genome, including a beta-glycosidase, an hypothetical membrane protein homologous to the major facilitator superfamily of transporters, and an open reading frame of unknown function. The alpha-xylosidase was overexpressed in Escherichia coli showing optimal activity at 90 degrees C and a half-life at this temperature of 38 h. The purified enzyme follows a retaining mechanism of substrate hydrolysis, showing high hydrolytic activity on the disaccharide isoprimeverose and catalyzing the release of xylose from xyloglucan oligosaccharides. Synergy is observed in the concerted in vitro hydrolysis of xyloglucan oligosaccharides by the alpha-xylosidase and the beta-glycosidase from S. solfataricus. The analysis of the total S. solfataricus RNA revealed that all the genes of the cluster are actively transcribed and that xylS and orf3 genes are cotranscribed.

Archaea↗

PubMed2000

Evidence for a recessive inheritance of Turcot's syndrome caused by compound heterozygous mutations within the PMS2 gene.

Turcot's syndrome is a genetic disease characterized by the concurrence of primary brain tumors and colon cancers and/or multiple colorectal adenomas. We report a Turcot family with no parental consanguinity, in which two affected sisters, with no history of tumors in their parents, died of a brain tumor and of a colorectal tumor, respectively, at a very early age. The proband had a severe microsatellite instability (MIN) phenotype in both tumor and normal colon mucosa, and mutations in the TGFbeta-RII and APC genes in the colorectal tumor. We identified two germline mutations within the PMS2 gene: a G deletion (1221delG) in exon 11 and a four-base-pair deletion (2361delCTTC) in exon 14, both of which were inherited from the patient's unaffected parents. These results represent the first evidence that two germline frameshift mutations in PMS2, an MMR gene which is only rarely involved in HNPCC, are not pathogenic per se, but become so when occurring together in a compound heterozygote. The compound heterozygosity for two mutations in the PMS2 gene has implications for the role of protein PMS2 in the mismatch repair mechanism, as well as for the presymptomatic molecular diagnosis of at-risk family members. Furthermore, our data support and enlarge the notion that high DNA instability in normal tissues might trigger the development of cancer in this syndrome.

Adenoma↗

PubMed2000

Synthesis and characterisation of a new class of stable S-adenosyl-L-methionine salts.

S-adenosyl-L-methionine (SAM) is an important metabolic intermediate that serves as a donor of methyl and aminopropyl groups to a variety of acceptor molecules. The molecule in vitro is unstable both in solution and in crystalline form undergoing irreversible conversion to 5'-methyltioadenosine (MTA) and homoserine lactone. Since this form of instability seems to be prevented in the cell of the living organism by bonds with macromolecules, we designed and developed a novel class of salts of SAM with large size anions to improve the stability of the sulfonium compound outside the cell. For this purpose we synthesised and characterised by NMR and IR spectroscopy anions consisting of amidic derivatives of taurine with fatty acids. Stability studies performed with the new SAM salts indicate that SAM becomes much more stable when it interacts with large size anions and in fact, more than 84% of the SAM is recovered after 36 months in lyophilized samples. The high stability of the new products widens the possibility of new therapeutic applications of SAM in human therapy.

Anions↗

PubMed2000

FSH treatment improves sperm function in patients after varicocelectomy.

One-hundred and eighty-three patients affected with idiopathic left varicocele, aged between 18 and 45 years, surgically treated have been studied. They were divided in 3 subsets according to sperm count: group A: <10 x 10(6)/ml, group B: 10-20 x 10(6)/ml, group C: >20 x 10(6)/ml. Six months after surgery 115 patients were treated for 3 months with pure human FSH: 75 IU i.m. every other day, while 68 patients treated with placebo served as control group. After therapy, group A showed a significant clear-cut improvement of sperm parameters: count, forward progression, swollen tails and cervical mucus penetration test (CMPT). In group B a significant improvement of sperm motility, viability, DNA integrity and CMPT was observed, while in group C only a significant improvement of CMPT was observed. In conclusion, it can be suggested that FSH treatment in patients after varicocelectomy could improve spermatogenesis, particularly in those who previously have more compromised sperm quality. On the contrary, no significant difference of sperm patterns was recorded in the control group before and after placebo.

Adolescent↗

PubMed2000

Hormonal and seminal evaluation of Leydig cell tumour patients before and after orchiectomy.

Seven patients (aged 25-38 years) were admitted because of mono- or bilateral gynaecomastia. Plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, testosterone, 17-beta-estradiol, delta4-androstenedione, dehydropiandrosterone sulphate (DHEA-S) and 17-OH-progesterone were determined and semen analysis was carried out. FSH and LH levels were also measured after acute LH-RH administration (100 microg intravenously), and testosterone and 17-beta-estradiol were also evaluated after acute human chorionic gonadotrophin (hCG) administration (5000 IU intramuscularly). Testicular echography demonstrated the presence of a solid hypoechoic tumour. Therefore all patients were submitted to hemicastration by orchidofuniculotomy and a benign Leydig cell tumour was diagnosed in the removed testes. Hormonal and semen evaluations were repeated 3, 6, 9 and 12 months after surgery. The data before and after surgery were compared with a control group of 10 age-matched males. Before surgery, patients showed low FSH basal plasma levels; high levels of 17-beta-estradiol and low testosterone levels similar to those after hCG administration. A dyspermia was observed. Unilateral orchidectomy eliminated the autonomous secretion of oestrogen(s) so an increase of LH, FSH and testosterone levels, together with an improvement of spermatogenesis, were obtained.

17-alpha-Hydroxyprogesterone↗

PubMed2000

FISH deletion mapping defines a single location for the Y chromosome stature gene, GCY.

At least 1 in 1000 males lacks part of the long arm of the Y chromosome. This chromosomal aberration is often associated with short stature and infertility. Deletion mapping and genotype-phenotype analysis have previously defined two non-overlapping critical regions for growth controlling gene(s), GCY(s), on the euchromatic portion of the Y chromosome long arm. These initial mapping assignments were based on the analysis of patients carrying a pure 46,XYq- karyotype as defined by classical cytogenetic karyotyping. Four genes have been assigned to the distal one of the two critical regions. To determine whether one or both of these two critical regions harbours GCY and whether one of the four genes assigned to the distal region is involved in determination of stature, nine adult patients with Yq chromosomal abnormalities were studied in detail. By PCR and FISH analysis, we showed that all patients with a previously defined pure 46,XYq- karyotype are actually mosaics with cells containing an idic(Y) or ring(Y) chromosome in association with 45,X0 cells. This leads us to conclude that (1) FISH is an absolute prerequisite for the correct identification of Y chromosomal rearrangements and (2) only patients with interstitial Y deletions are reliable predictors for the physical location of stature gene(s) on Yq. Our molecular analyses of chromosomes from patients with interstitial Yq deletions finally establishes the proximal interval between markers DYZ3 and DYS11 as the only GCY critical interval. No functional gene has so far been identified in this region adjacent to the centromere.

Adult↗

PubMed2000

Accuracy of indirect estimation of oxyhaemoglobin saturation in patients with respiratory failure.

The indirect estimate of oxyhaemoglobin saturation (Sa,O2) is largely used in the management of patients with respiratory failure. The aim of this study was to evaluate the accuracy of the Sa,O2 values calculated by using both the Siggaard-Andersen (SA) and the Severinghaus (SE) equation, in comparison with the real Sa,O2 values measured by a co-oximeter. A total of 558 arterial blood samples were analysed. On average, only a slight overestimation was found for Sa,O2 estimated by the SA (2.35 +/- 5.75%) and the SE (2.37 +/- 5.65%) equations in comparison with the real values. However, a difference higher than 5% between estimated and real Sa,O2 values was demonstrated in more than 20% of the blood samples evaluated. This difference was higher than 10% in 9% of the samples, with similar results obtained with the two equations. The discrepancy between real and estimated values, probably due, at least in part, to errors in measurement of arterial oxygen tension (Pa,O2) and pH, was maximally evident for Sa,O2 values lower than 70%. An indirect estimate of Sa,O2 is not homogeneously accurate, and the clinical consequence of this finding might be especially dangerous in monitoring patients with severe respiratory failure.

Humans↗

PubMed1999

Acute pulmonary embolism: clinical outcomes in the International Cooperative Pulmonary Embolism Registry (ICOPER)

BACKGROUND: Pulmonary embolism (PE) remains poorly understood. Rates of clinical outcomes such as death and recurrence vary widely among trials. We therefore established the International Cooperative Pulmonary Embolism Registry (ICOPER), with the aim of identifying factors associated with death. METHODS: 2454 consecutive eligible patients with acute PE were registered from 52 hospitals in seven countries in Europe and North America. The primary outcome measure was all-cause mortality at 3 months. The prognostic effect of baseline factors on survival was assessed with multivariate analyses. FINDINGS: 2110 (86.0%) patients had PE proven by necropsy, high-probability lung scan, pulmonary angiography, or venous ultrasonography plus high clinical suspicion; ICOPER accepted without independent review diagnoses and interpretation of imaging provided by participating centres; 3-month follow-up was completed in 98.0% of patients. The overall crude mortality rate at 3 months was 17.4% (426 of 2454 deaths, including 52 patients lost to follow-up): 179 of 397 (45.1%) deaths were ascribed to PE and 70 of 397 (17.6%) to cancer, and no information on the cause of death was available for 29 patients. After exclusion of 61 patients in whom PE was first discovered at necropsy, the mortality rate at 3 months was 15.3% (365 of 2393 deaths). On multiple-regression modelling, age over 70 years (hazard ratio 1.6 [95% CI 1.1-2.3]), cancer (2.3 [1.5-3.5]), congestive heart failure (2.4 [1.5-3.7]), chronic obstructive pulmonary disease (1.8 [1.2-2.7]), systolic arterial hypotension (2.9 [1.7-5.0]), tachypnoea (2.0 [1.2-3.2]), and right-ventricular hypokinesis on echocardiography (2.0 [1.3-2.9]) were identified as significant prognostic factors. INTERPRETATION: PE remains an important clinical problem with a high mortality rate. Data from ICOPER provide rates and highlight adverse prognostic categories that will help in planning of future trials of high-risk PE patients.

Acute Disease↗

PubMed1999

Electrocardiographic signs of chronic cor pulmonale: A negative prognostic finding in chronic obstructive pulmonary disease.

BACKGROUND: Chronic cor pulmonale (CCP) is a strong predictor of death in chronic obstructive pulmonary disease (COPD). The aims of this study were to assess the prognostic role of individual ECG signs of CCP and of the interaction between these signs and abnormal arterial blood gases. METHODS AND RESULTS: Two hundred sixty-three patients (217 men) with COPD, mean age 67+/-9 years, were grouped according to whether they had no ECG signs (group 1, n=100) or >/=1 ECG signs (group 2, n=163) of CCP and were followed up for 13 years after an exacerbation of respiratory failure. The median survival was significantly shorter in group 2 than in group 1 (2.58 versus 3. 45 years, respectively; Mantel-Cox test, 9.58; P=0.002). The Cox regression analysis identified S1S2S3 pattern, right atrial overload (RAO), and alveolar-arterial oxygen gradient (PAO2-PaO2) >48 mm Hg during oxygen therapy as the strongest predictors of death, with hazard rate (HR)=1.81 (95% CI, 1.22 to 2.69), HR=1.58 (95% CI, 1.15 to 2.18), and HR=1.96 (95% CI, 1.19 to 3.25), respectively. The median survivals of patients having both S1S2S3 pattern and RAO (n=14) and of patients having either S1S2S3 pattern or RAO (n=77) were 1.33 and 2.70 years, respectively (P=0.022). Group 2 patients had a 3-year survival of 18% or 53%, depending on whether their PAO2-PaO2 during oxygen therapy was or was not >48 mm Hg. CONCLUSIONS: Some ECG signs of CCP and PAO2-PaO2 >48 mm Hg during oxygen therapy qualified as a simple and inexpensive tool for targeting subsets of COPD patients with severe or very severe short-term prognosis.

Aged↗

PubMed1999

Mutation analysis of the BRCA1 and BRCA2 genes results in the identification of novel and recurrent mutations in 6/16 flemish families with breast and/or ovarian cancer but not in 12 sporadic patients with early-onset disease. Mutations in brief no. 224. Online.

Since the identification of the BRCA1 and BRCA2 genes (MIM#s 113705 and 600185), more than hundred different mutations throughout both genes have been reported. Recurrent mutations are rare and mainly due to founder effects. We analyzed 12 sporadic female patients with breast cancer before age 35, as well as 16 unrelated families, presenting with either (i) at least 3 first degree relatives with breast and/or ovarian cancer diagnosed at any age, or (ii) at least 2 first and/or second degree relatives with breast and/or ovarian cancer before age 45 years. We performed a protein truncation test for BRCA1 exon 11 and BRCA2 exons 10 and 11 and heteroduplex analysis for all the remaining exons of BRCA1 and 2. Presence of genomic deletions encompassing exons 13 or 22 of BRCA1, known to be Dutch founder mutations, was investigated by PCR. In 6/16 (37.5%) unrelated families the causal mutation in either the BRCA1 or BRCA2 gene was identified. Four different mutations were found in the BRCA1 gene: IVS5+3A>G (intron 5), 1191delC (exon 11), R1443X (exon 13), IVS22+5G>A (intron 22) and two in the BRCA2 gene: 6503delTT (exon 11), 6831delTG (exon 11). 1191delC (BRCA1) and 6831delTG (BRCA2) are novel mutations. IVS5+3A>G in exon 5 of BRCA1 published by Peelen et al. (1997) as a novel Belgian mutation, was identified in one additional family, not fulfilling our inclusion criteria. In the group of 12 sporadic female patients no mutations were found.

Adult↗

PubMed1999

A microfiltration bioreactor to achieve high cell density in Sulfolobus solfataricus fermentation.

A novel technique is proposed to achieve higher cell yield in extremophile fermentation. Because the accumulation of toxic compounds is thought to be responsible for low biomass yields, a bioreactor has been designed based on a microfiltration hollow-fiber module located inside the traditional fermentation vessel. Using the cultivation of the thermoacidophilic archeon Sulfolobus solfataricus theta as a model, a biomass of 35gl(-1) dry weight was obtained which proved greater than that of 2gl(-1) obtained in batch fermentation. The bioreactor was characterized by running several fermentation experiments to check the high stability of the membrane module to sterilization cycles, high temperatures, and acidic pHs, even for prolonged periods of time. It was shown that the exhaust medium is unable to sustain growth for the presence of toxic compounds, and ultrafiltration and ion-exchange techniques were used in all the attempts to regenerate it. The results demonstrated the ability of the method to lower inhibitor concentrations and prolong the growth phase, thus achieving high cell density. Furthermore, they indicated that the toxic compounds are ionic species of less than 1kDa.

Bioreactors↗

PubMed1999

Three submicroscopic deletions at the APC locus and their rapid detection by quantitative-PCR analysis.

We describe three unrelated kindreds, affected by familial adenomatous polyposis (FAP), with 5q submicroscopic deletions that encompass the entire adenomatous polyposis coli (APC) gene and the adjacent DP1 gene. In one family the deletion encompasses also the MCC (mutated in colon cancer) gene. Affected members of these families had dysplastic adenomatous polyps and congenital hypertrophy of the retinal pigment epithelium (CHRPE); no individual was affected by mental retardation or facial dysmorphism. The deletions were detected by linkage analysis with several intragenic and closely flanking polymorphic markers and confirmed by a quantitative PCR analysis. This procedure could have an impact on the detection of the molecular defect in FAP patients in whom mutational analysis fails to identify the specific mutation.

Adenomatous Polyposis Coli↗

PubMed1999

The effect of chronic treatment with GH on gonadal function in men with isolated GH deficiency.

Eleven adult males, previously submitted to neurosurgery because of a pituitary lesion (three with craniopharyngioma, three with clinically non-functioning adenoma and five with macroprolactinoma) were treated with recombinant GH for 12 months after the diagnosis of GH deficiency was made. Circulating FSH, LH, prolactin, testosterone, 17 beta-estradiol (E2), dehyroepiandrosterone (DHEA-S), androstenedione. 17-OH-progesterone (17OHP), IFG-I, and steroid hormone-binding protein (SHBG) levels were assayed before and after CG test at study entry and 6 and 12 months after GH treatment. A significant increase in plasma IGF-I levels was obtained after 6 and 12 months of GH treatment. In addition, CG-stimulated, but not baseline, testosterone levels showed a significant increase after 6 and 12 months of GH treatment when compared with study entry (9.6 +/- 0.5 and 9.9 +/- 0.5 vs 7.9 +/- 0.5 ng/ml; P < 0.05). Baseline, but not CG-stimulated, serum 17OHP levels were significantly increased only after 12 months of GH treatment (1.7 +/- 0.1 vs 1.4 +/- 0.1 ng/ml; P < 0.05). No significant difference was found as far as both basal and CG-stimulated E2, androstenedione, DHEA-S and SHBG were concerned. With regards to the semen analysis, only seminal plasma volume was significantly increased after 12 months of GH treatment (2.9 +/- 0.3 vs 1.7 +/- 0.3 ml; P < 0.05). No significant change in sperm count, motility and abnormal forms was observed. These data show that GH treatment displays a clear-cut effect upon Leydig cell function and increases the production of seminal plasma volume in fertile adult males with isolated GH deficiency.

17-alpha-Hydroxyprogesterone↗

PubMed1999

Different effects of microwave energy and conventional heat on the activity of a thermophilic beta-galactosidase from Bacillus acidocaldarius.

The effect of microwave (f = 10.4 GHz) irradiation on a thermostable enzyme was experimentally tested, showing that irreversible inactivation is obtained. Enzymatic solutions (500 microliters, with concentrations between 10-100 micrograms/ml) were exposed at 70 degrees C, at SAR levels of 1.1 and 1.7 W/g for 15, 30, 45, or 60 min, and their activity was compared to that of a sample heated in a water bath at the same temperature. The residual activity of the exposed samples depends on enzyme concentration, microwave power level, and exposure time; activity was reduced to 10% in 10 micrograms/ml solutions treated at 1.7 W/g for 60 min. Microwave effects disappeared at concentrations above 50 micrograms/ml. These results were not found following water bath heating at the same temperature and durations.

Bacillus↗

PubMed1999

Immobilization of enzymes on spongy polyvinyl alcohol cryogels: the example of beta-galactosidase from Aspergillus oryzae.

The catalytic properties of a beta-galactosidase from Aspergillus oryzae, entrapped into a spongy polyvinyl alcohol cryogel, were studied. This polymeric matrix was selected because of its mild conditions of preparation and its stability, biocompatibility, structural strength and diffusive properties. The enzyme was entrapped, in high percentage, into cryogel sponges and its activity and kinetic parameters were determined and compared with those of the free enzyme, using as substrates o-nitrophenyl-beta-galactopyranoside (ONPG) or lactose. The immobilized enzyme showed a reduced activity with ONPG and lactose, probably because of substrate diffusion limitations through the matrix, but it was more stable to temperature, pH and ionic strength than the free enzyme. Lactose hydrolysis under continuous experimental conditions was performed using the matrix-enzyme cited above.

Animals↗

PubMed1999

[Acquired renal cystic disease. Polysyndromatic entity as cause of non-immunological progression of renal failure].

We present a patient with rapidly progressive glomerulonephritis who after immunosuppression and hemodialysis treatment showed an improvement in his condition. Eight years later a computed tomography discovered an acquired renal cystic disease (ARCD) characterized by the development of 3 or more cysts in both kidneys of patients with chronic renal disorders and no history of hereditary cystic disease. ARCD may be asymptomatic or as it occurred in this patient, associated with several complications related to renal cysts such as polyuria-polydipsia syndrome, renal hemorrhagic cyst, perinephric hemorrhage and renal cell carcinoma. Along 12 years of follow-up the renal function showed a very slow declination which could be attributed to ARCD. It is suggested that ARCD can be considered as a non-immunological factor of renal progression when it develops in patients with mild chronic renal failure.

Adenocarcinoma, Clear Cell↗

PubMed1998

Synthesis and comparison of the antiinflammatory activity of manoalide and cacospongionolide B analogues.

We have synthesized analogues of two naturally occurring antiinflammatory marine compounds, manoalide and cacospongionolide B, containing a pyranofuranone moiety which is considered the pharmacophoric group. The two compounds, and hence their analogues, differ in the presence or absence in the dihydropyran ring of an hemiacetal function which was considered essential to irreversibly inactivate phospholipase A2 (PLA2). The two series of compounds were tested for their inhibitory effects on secretory PLA2 belonging to the groups I, II, and III, and the activities were found to be similar in both series, irrespective of the presence or absence of the additional hemiacetal function. In addition, the PLA2 inhibitory activity increases with the increasing hydrophobic character of the side chain linked to the pyranofuranone moiety. The most active compounds, FCA and FMA, carry a farnesyl residue linked to the pyranofuranone substructure. The most potent PLA2 inhibitor, FMA, was tested in the mouse carrageenan paw edema at the oral dose of 10 mg/kg and showed an activity similar to the reference antiinflammatory drug, indomethacin.

4-Butyrolactone↗

PubMed1998

Neuronorm is a potent and water soluble neurokinin A receptor antagonist.

We report here the synthesis and preliminary pharmacological characterization of a novel water soluble Neurokinin A receptor antagonist named Neuronorm. The synthesis was achieved in high yield by a combination of classical peptide synthesis methodologies, in both solution and solid phase. The pharmacological properties as neurokinin A receptor antagonist were assessed in in vitro experiments on rat vas deferens and guinea pig trachea, and were compared to those of MEN10627.

Animals↗