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Biomedical subjects

A Serra

Publications and source records attributed to A Serra.

At least 145 records · Page 8Linked to original sources
PubMed1994

[Evolution of the serum aluminum values in the Piedmont dialysis population. Dialysis Centers of the Piedmont].

The authors have evaluated the evolution of values of serum aluminium concentration (Als) in the whole pool of patients undergoing RDT in Piedmont in the years 1982-1990. We have compared the data of the Piedmont Regional Registry of Dialysis and Transplantation at the end of 1990 to those obtained in 1982, 1986 and 1989. A progressive reduction has been observed in the percentage of patients with Als > 100 micrograms/l, who were 13.5% of the pool in 1982 and 7.5% in 1986 and finally decreased to 1.5% in 1990. This is yet more evident for patients dialyzing at home as in 1982 43% of them had a Als > 100 micrograms/l, whereas in 1986 only 8.2% did and in 1990 this percentage had decreased to 3.6%. The values of Als (distinguished by type of treatment of chronic renal failure) show end confirm the improvement of the situation of aluminium accumulation, specially as regards bicarbonate HD where the percentage of patients with Als > 100 micrograms/l decreases from 10.5% in 1986 to 1.7% in 1990. These data point out the efficacy of prevention and control programs regarding aluminium pathology performed in the last years in Piedmont. This has led to a reduction of the severe accumulation syndromes observed in the first years of '80 and has allowed the nephrologist to prepare more correct therapeutic prescriptions.

Aluminum↗
PubMed1994

Analysis of the p53 gene in myeloid malignancies associated with chromosomal abnormalities involving the short arm of chromosome 17.

p53 protein is encoded by a tumor-suppressor gene located on the short arm of chromosome 17. We looked for mutations or rearrangements of the p53 gene in five patients with acute transformation of a chronic myeloproliferative disorder and cytogenetic anomalies involving the short arm of chromosome 17. Two patients had a isochromosome i(17q); three more patients showed the presence of unbalanced translocations involving chromosome 17. One of these patients had a single base pair deletion, causing a frameshift mutation, in the exon 5 of the p53 gene. The karyotype of this patient showed a translocation t(5;17)(q11;p11), with loss of a normal homologue of both chromosomes 5 and 17. In all other cases the configuration of the p53 gene, as tested by PCR-SSCP analysis of exons 5 to 9 and Southern blot, was normal. Our data suggest that mutations of the p53 gene occur in a minority of hemopoietic malignancies characterized by monosomy for the short arm of chromosome 17. However, the unbalanced translocation t(5q;17p) could be a chromosomal abnormality specifically associated with loss of function of the p53 gene.

Base Sequence↗
PubMed1994

Molecular mechanisms of tumor progression in chronic myeloproliferative disorders.

We have investigated the involvement of tumor suppressor genes (p53 and RB1) and dominantly acting oncogenes (Ras family genes) in BCR/ABL positive and negative chronic myeloproliferative disorders (CMPD) at different stages of the disease, including 26 cases of BCR/ABL+ chronic myeloid leukemia (CML) blast crisis, 9 myelosclerosis with myeloid metaplasia, 4 polycythemia vera, 10 essential thrombocythemia, 1 juvenile CML, and 8 BCR/ABL- CML. The presence of mutations in p53 exons 5 through 9, as well as in RB1 exons 10-27 and in N-, K-, H-Ras exons 1 and 2 was tested by the PCR-Single Strand Conformation Polymorphism technique and by PCR-Direct Sequencing. In addition, Southern blot analysis was used to investigate the occurrence of gross rearrangements in the p53 gene as well as loss of heterozygosity at 17p13, the site of p53. Acute phase BCR/ABL-CMPD cases displayed a high frequency of p53 (2/7) and Ras (3/7) lesions, whereas BCR/ABL- CMPD in chronic phase displayed only germline p53 and Ras sequences. Conversely, p53 inactivation was restricted to only 1/26 cases of BCR/ABL+ CML blast crisis. No alterations in the RB1 gene were detected in any of the cases analyzed. These data indicate that p53 inactivation and/or Ras activation might play a role in acute transformation of BCR/ABL- CMPD and that the molecular mechanisms of tumor progression may be different in BCR/ABL+ versus BCR/ABL-CMPD.

Chronic Disease↗
PubMed1994

[Chronic gastroenteritis caused by Plesiomonas shigelloides in adult patients. Report of 3 cases].

We report the clinical characteristics of three adult patients with a chronic gastroenteritis (more than 10 days duration) due to Plesiomonas shigelloides. The three patients presented previously an underlying disease; a chronic liver disease (alcoholic and viral) and a cancer disease. Although the immunosuppressed condition of the patients, the diarrhea was moderate with 6-12 movements/day; the feces were liquid with mucose and blood. No one patient presented fever but all of them had important abdominal pain. Two patients were treated with cotrimoxazole and ciprofloxacin because of their underlying disease. We review the clinical characteristics of chronic diarrhea caused by P. shigelloides in adult patients, and the possibility that this microorganism would be considered a true enteropathogen.

Aged↗
PubMed1993

[Deep venous thrombosis associated with necrotizing vasculitis].

The association of deep vein thrombosis with systemic necrotizing vasculitis is infrequent. Herein are referred two patients with microscopic polyarteritis and one patient with overlap syndrome who developed deep vein thrombosis which complicated in two cases with pulmonary embolism. The clinical features and the pathogenic mechanisms involved in this infrequent association are analyzed. In two patients the thrombosis was simultaneous with the diagnosis of vasculitis. In one patient deep vein thrombosis was the cause of hospital admission. Advanced age and thrombocytosis are factors associated to vasculitis, which may favor the development of thromboembolic disease. The presence of antiphospholipid syndrome was discarded. Although infrequent, this association should be considered because of the potential severe complications.

Aged↗
PubMed1993

Balloon mitral commissurotomy for mitral restenosis after surgical commissurotomy.

Balloon mitral commissurotomy (BMC) was performed in 113 patients. Of these patients, 27 (24%) (25 women and 2 men, aged 49 +/- 13 years) had recurrent mitral stenosis 13 +/- 6 years (range 5 to 29) after surgical commissurotomy. Eleven patients (41%) were considered at high risk for surgery. BMC resulted in an increase in mitral valve area from 1.1 +/- 0.3 to 1.9 +/- 0.7 cm2 (p < 0.0001), and a decrease in mean mitral gradient from 16 +/- 7 to 6 +/- 3 mm Hg (p < 0.0001). An optimal result of BMC (increase in valve area > or = 25% with a post-BMC valve area > or = 1.5 cm2) was obtained in 18 patients (67%). The results did not differ from those observed in the 86 patients of our entire series without prior surgical commissurotomy. Patients with an optimal result of BMC had a more recent surgical commissurotomy and lesser morphologic alterations of the mitral valve than did those with a nonoptimal result. Patients with echocardiographic scores < 10 had an 80% success rate of BMC; however, this rate decreased to 29% for those with scores > or = 10. One patient (4%) died from a cerebrovascular accident. Clinical follow-up at 1 year showed persistent clinical improvement in 89% of patients with an optimal result of BMC; 72% were in New York Heart Association class I and 17% in class II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Preferential clustering of chromosomal breakpoints in Burkitt's lymphomas and L3 type acute lymphoblastic leukemias with a t(8;14) translocation.

We have analyzed the type of MYC/IG heavy-chain locus (IGH) rearrangement present in 15 patients affected by t(8;14)-positive primary Burkitt's lymphoma or acute lymphoblastic leukemia of the L3 type in an attempt to map in detail the locations of the chromosome 8 and chromosome 14 breakpoints. The almost constant position of the chromosome 8 breakpoint (within or immediately 5' of the MYC gene) together with two distinct clusters of breakpoints on chromosome 14 resulted in two main types of MYC/IGH (present in 12 of 15 cases). In the first type (six cases), the MYC gene or at least its coding portion was joined with the JH region on chromosome 14, whereas in the second, present in another six cases, the MYC gene and the C alpha I region were juxtaposed. Physical linkage between the translocated MYC and a known enhancer element of the IGH locus is the common feature in the two types of rearrangement, suggesting that a high-level constitutive expression plays a prominent role in MYC activation. Interestingly, the chromosome 14 break site within the switch alpha 1 region, which has been only occasionally described in other cases, is present in 40% of our patients, suggesting the existence of preferential breakpoint cluster regions in cases of similar geographic origin.

Adolescent↗
PubMed1993

A frequent EcoRI polymorphism in the bcl-2 gene.

The frequency and Mendelian inheritance of an EcoRI polymorphism mapping within the bcl-2 locus was evaluated. The high frequency of the two identified alleles makes it a useful marker for genes located on the 18q21 region.

Alleles↗
PubMed1993

Spinal cord transection in adult rats: effects of local infusion of nerve growth factor on the corticospinal tract axons.

The spinal cord of adult female rats was completely transected at the T8 level. Nerve growth factor (NGF) was administered at the lesion site via indwelling, implanted, osmotic minipumps. Purified NGF was supplied at doses of 100, 200, and 500 micrograms during a 30-day period. Control rats were treated with saline. At the end of the treatment, the proximal stump of corticospinal tract axons in the spinal cord was labeled with anterograde transported horseradish peroxidase (HRP) injected into the sensorimotor cortex. In control rats, the corticospinal tract axons ended abruptly, proximal to the zone of maximal damage. Sterile swellings developed at the axon tips, and no labeled axonal sprouts were apparent. On the contrary, in NGF-treated animals, the leading front of the corticospinal tract axons showed a trend of approaching the zone of maximal damage following abnormal paths through the dorsal-injured white matter. Axonal sprouts were seen more proximally, traveling toward the transection site in aberrantly located dorsal paths, completely outside the normal position of the corticospinal tract. NGF seems to partly restore the pattern of the regenerative behavior of the severed corticospinal tract axons after spinal cord transection in newborn rats, i.e., the induction of axonal sprouting in aberrantly located dorsal paths. An automated image analysis of the HRP reaction field close to the transection site demonstrated that the density of HRP-labeled axons in the corticospinal tract was significantly higher in the NGF-treated rats than in the control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Molecular defects associated with the acute phase CML.

Parts of the Bcr/Abl hybrid transcript supposed to be important for its transforming ability were sequenced in a series of CML blast crises, in order to evaluate the possible presence of alterations responsible for the disease transition from the chronic to the acute phase. In addition, the N- and Ki-ras as well as the p53 involvement was investigated by exploring their structure and expression in the same patients. We used traditional types of molecular analysis including Southern and Northern blot, together with methods that allow a rapid detection of point mutations and microdeletions, such as SSCP, single strand conformation polymorphism and direct sequencing. The results obtained may be summarized as follows: no alterations were found in the parts of the Bcr/Abl transcripts investigated in the present study (SH2, SH3 and the region surrounding codon 832); p53 alterations were observed in 5% and N- and Ki-RAS mutations in 5% of the cases examined. These molecular defects are therefore responsible for the clinical progression of the Ph1-positive CML only in a minority of cases.

Base Sequence↗
PubMed1993

[Percutaneous coronary angioscopy].

In the last few years, major advances in catheter technology and miniaturization of fiber optics have allowed percutaneous coronary angioscopy to become a reality. Current angioscopy systems provide an outstanding image quality yielding precise evaluation of coronary atherosclerosis morphology in its various clinical manifestations. However, coronary angioscopy is a new diagnostic tool whose indications and specific role are yet to be delineated. Investigation on the potential roles of this technology are mainly centered in the field of acute coronary syndromes and interventional coronary therapies. In the near future, coronary angioscopy may play an important role in the investigation of the natural history of coronary artery disease, in the field of thrombolysis, and in the selection of specific therapy. In this article, coronary angioscopy system and technique are described and its potential clinical applications discussed.

Angina, Unstable↗
PubMed1993

[Short- and mid-term results of percutaneous mitral valve commissurotomy for restenosis after surgical commissurotomy].

Fifty nine of the 280 percutaneous mitral valvuloplasties (21%) performed between March 1987 and December 1991 at the Montreal Heart Institute were carried out for symptomatic mitral restenosis 15 +/- 6 years after surgical commissurotomy. The patients were selected according to echocardiographic criteria. The mitral valve disease was comparable to that of patients without previous surgical commissurotomy. Patients with good hemodynamic result had undergone surgical commissurotomy more recently and had less severe valvular damage than patients with an incomplete (n = 10) or poor result (n = 7). One patient died of a cerebral embolism during the procedure, two patients underwent emergency surgery for a mitral valve rupture and 4 patients had an atrial septal defect with Qp/Qs ratio greater than 1.5 by oximetry. The numbers of successes and complications were comparable to those observed in patients without previous surgical commissurotomy. The patients who had undergone previous surgical commissurotomy were followed up for 1 year. At 12 months, 4 remained in Class II of the NYHA classification, 44 (74%) were improved by at least 1 functional class and 10 (17%) had required a mitral valve replacement. Percutaneous mitral valvuloplasty is therefore a useful procedure in patients with moderate degrees of valvular disease who develop restenosis after surgical commissurotomy. A functional improvement can be expected in 3/4 of patients Complications related to the procedure are rare and acceptable compared with the risks of a second thoracotomy. Failure of percutaneous mitral valvuloplasty is generally due to the degree of valvular disease which contraindicated surgical commissurotomy and required mitral valve replacement.

Adult↗