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Biomedical subjects

A Serra

Publications and source records attributed to A Serra.

At least 163 records · Page 9Linked to original sources
PubMed1993

Mutations in the P53 and RAS family genes are associated with tumor progression of BCR/ABL negative chronic myeloproliferative disorders.

We have investigated the involvement of the p53 tumor suppressor gene and RAS family proto-oncogenes in BCR/ABL-negative chronic myeloproliferative disorders (CMPD), including nine cases of myelosclerosis with myeloid metaplasia, four polycythemia vera, 10 essential thrombocythemia, one juvenile chronic myeloid leukemia, and eight BCR/ABL-negative chronic myeloid leukemia. Twenty-five samples were studied in the chronic phase, while seven samples were analyzed in the acute accelerated or blastic phase. The presence of mutations in p53 exons 5-9, as well as in N-, K-, H-Ras exons 1 and 2 (containing codons 12, 13, and 61) was tested by the polymerase chain reaction (PCR) single strand conformation polymorphism technique and by PCR direct sequencing. In addition, restriction analysis was performed to screen for gross rearrangements within the p53 locus. Alterations of the p53 tumor suppressor gene and Ras family proto-oncogenes were detected in 2/7 and 3/7 cases of acute phase BCR/ABL-negative CMPD, respectively, while consistently negative in all the chronic phase samples analyzed. These results suggest that p53 inactivation and/or Ras activation might play a role in acute transformation of BCR/ABL-negative CMPD.

Adolescent↗
PubMed1993

[Ocular involvement in rheumatoid arthritis].

The authors evaluated ocular involvement in 23 patients affected by rheumatoid arthritis (RA) according to ARA criteria. Slit-lamp biomicroscopic examination showed signs of keratoconjunctivitis sicca in one patient (4%), while a positive bilateral Schirmer test was found in six subjects (26%). Fluorescein angiography, carried out in 11 of the 23 RA patients, showed retinal vasculitis in 18% of the patients examined, even if no clinical and ophthalmoscopic signs of retinal vessel inflammation were present. The authors suggest that fluorescein angiography should be performed in patients affected by particularly active RA, with recent onset of the disease (< 12 months), high titres of classical IgM rheumatoid factor and raised concentrations of circulating immune complexes. The study confirmed moreover the uncommon ocular toxicity related to the drugs frequently employed in RA treatment (antimalarials, gold salts, glucocorticoids). Indeed, only one case (4%) of posterior subcapsular cataract clearly related to steroid therapy was found.

Adult↗
PubMed1992

Long-term (9 to 33 months) echocardiographic follow-up after successful percutaneous mitral commissurotomy.

Late results after successful percutaneous mitral commissurotomy were assessed by prospective clinical and echocardiographic follow-up. Fifty-seven patients were followed for a mean of 19 +/- 6 months (range 9 to 33) after the procedure. Mitral valve area (measured by Doppler half-time method) increased from 1.0 +/- 0.2 to 2.2 +/- 0.5 cm2 immediately after commissurotomy, and then decreased to 1.9 +/- 0.5 cm2 at follow-up (p less than 0.05), whereas gradient did not change after its immediate postcommissurotomy reduction. Echocardiographic restenosis (mitral valve area less than or equal to 1.5 cm2 with greater than 50% reduction of initial gain) was seen in 12 of 57 patients (21%). Atrial shunting, detected by transthoracic color Doppler in 61% of patients immediately after the procedure (color flow jet through atrial septum), persisted in 30% at follow-up. Restenosis by univariate analysis correlated with age, smaller valve area after the procedure, and higher echocardiographic score. Multivariate analysis identified leaflet mobility and calcifications as the components of a score that was predictive for restenosis. Magnitude of shunt (pulmonary-to-systemic flow ratio greater than 1.5), use of a Bifoil balloon (2 balloons on 1 shaft), and smaller valve area after the procedure were predictors by multivariate analysis of the persistence of atrial shunting. Clinical improvement persisted at long-term follow-up (mean New York Heart Association class 1.6 +/- 0.6 vs 2.6 +/- 0.6 before commissurotomy). Improvement of greater than or equal to 1 functional class was seen in 75% of patients (80% of those without and 58% of those with restenosis); patients with a shunt did not differ from the entire group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Emergence of resistance to erythromycin and fluoroquinolones in thermotolerant Campylobacter strains isolated from feces 1987-1991.

During the period 1987 to 1991 a retrospective study was performed to determine the resistance of thermotolerant Campylobacter species isolated from feces to erythromycin and fluoroquinolones. Of the 672 strains studied, 614 (91.3%) were identified as Campylobacter jejuni and 58 (8.7%) as Campylobacter coli. During the study period the rate of resistance of Campylobacter jejuni to erythromycin remained relatively stable (0.9-3.5%), while resistance of Campylobacter coli to erythromycin emerged later (1989) with much higher rates (14.8-33%). Overall, 11.8% and 10.7% of Campylobacter jejuni strains isolated after 1987 were resistant to nalidixic acid and ciprofloxacin respectively, resistance increasing from 2.3% in 1988 to 32% in 1991. In 1991 the first strains of Campylobacter coli with resistance to these fluoroquinolones were detected (rates 29% and 26% respectively). Of the strains resistant to nalidixic acid, only 10.9% were susceptible to ciprofloxacin.

Anti-Infective Agents↗
PubMed1992

Red cell membrane protein lateral mobility in diabetes mellitus.

In a group of 24 diabetics subdivided for type, we evaluated the red cell membrane protein lateral mobility marking intact red cells with pyrene-3-maleimide (3-PM) and calculating the dimer to monomer fluorescence intensity ratio (Iex/Im). The same fluorescent parameter was determined in a group of 13 normal controls. From the obtained data, it is evident that the red cell membrane protein lateral mobility clearly discriminates normals from diabetics of type 1 and 2. In normals and in diabetics of type 1 and 2 no relationship is present between this fluorescent determinant and the glycometabolic parameters (FBGL and HbA1c); considering all the diabetics, a negative relationship is evident between Iex/Im ratio and HbA1c only.

Adolescent↗
PubMed1992

[The suicide phenomenon and fermentative metabolic activity in strains of the Aeromonas group isolated from feces].

We study the "suicide" phenomena as well as metabolic pathways of mixed acids (methyl red test, MR) and butylene glycol (Voges-Proskauer, VP), in 107 strains belonging to mesophilic Aeromonas group, isolated from stools. The strains have been identified as A. hydrophila, 28 cases (26.1%), A. sobria 26 cases (24.3%) and A. caviae 53 cases (49.6%). All A. caviae strains behave homogeneously as F+, RM+ and VP-, independently of temperature (30 or 37 degrees C). A. hydrophila strains only showed their trend to "suicide" at 37 degrees C, being this behavior linked to RM test positivity. At 30 degrees C all strains were NS and RM-, keeping always positive the VP test (both temperatures). In A. sobria we have recorded changes in their behavior related to the temperature of incubation. At 37 degrees C, 57.7% were NS, whereas at 30 degrees C, 69.2% showed the same phenotype. The metabolic activity had remained stable, therefore F+ strains were VP and RM+, and NS strains were VP+ and RM-. It seems that FS is a phenotypic behavior of this bacterial group species and temperature-dependent, and also is related to a fermentative metabolic activity modulation of each of them.

Aeromonas↗
PubMed1992

[Immediate and mid-term results of percutaneous pulmonary valvotomy in adults. Apropos of 10 cases].

Percutaneous pulmonary valvulotomy (PPV) is the treatment of choice for isolated congenital pulmonary stenosis of infancy. However, experience with this technique in the adult is much more limited. From November 1983 to November 1990, PPV was performed in 10 adults in our Institute. The mean age was 40 +/- 19 years (range 21 to 71 years). Before PPV, 4 patients were in functional Class II and 6 in functional Class III of the NYHA classification. All procedures were successful with no complications. The right ventricular systolic pressure decreased from 98 +/- 35 to 57 +/- 30 mmHg (p less than 0.01) and the mean pulmonary gradient decreased from 57 +/- 30 to 23 +/- 15 mmHg (p less than 0.01). The cardiac output was unchanged: 5.3 +/- 2.8 and 5.9 +/- 2.6 l/mn (not significant). Pulmonary valve area increased from 0.59 +/- 0.3 to 1.15 +/- 0.5 cm2 (p less than 0.01). The post-dilatation infundibular gradient was less than 10 mmHg in all patients. After an mean follow-up period of 29 +/- 26 months all but one patient (Class II) were in functional Class I. Exercise capacity was 6.9 +/- 2 Mets. Doppler echocardiography indicated a stable mean pulmonary gradient of 16.5 +/- 6.8 mmHg after PPV and 15.0 +/- 7.0 mmHg during follow-up. Pulmonary regurgitation was less than Grade I in all cases. In conclusion, PPV is an effective treatment for adult pulmonary stenosis and carries a low risk. The mid term results are excellent.

Adult↗
PubMed1991

Impaired response of atrial natriuretic factor to blood volume expansion in acute right ventricular infarction.

To assess the role of atrial natriuretic factor (ANF) in right ventricular (RV) infarction, 30 patients with inferior wall acute myocardial infarction (15 with RV involvement) and normal left heart filling pressures were studied 39 +/- 12 hours after the onset of symptoms. Serial measurements of cardiac output, right atrial, pulmonary artery and pulmonary wedge pressures, as well as plasma ANF, plasma renin activity, plasma aldosterone and vasopressin were obtained before and 30 minutes after acute volume expansion to raise wedge pressure greater than or equal to 20 mm Hg. Baseline mean right atrial pressure and plasma ANF levels were greater in patients with than without RV infarction (8 +/- 3 vs 5 +/- 2 mm Hg; p less than 0.0001, and 4.6 +/- 2.9 vs 2.7 +/- 1.5 fmol/ml; p less than 0.05, respectively). There were no differences in other baseline hemodynamic or humoral parameters between both groups. After volume expansion, pulmonary wedge pressure was similar in both groups, but right atrial pressure increased to higher levels in patients with RV infarction (19 +/- 2 vs 14 +/- 2 mm Hg; p less than 0.0001). Despite this greater stimulus for ANF secretion, the increase in plasma ANF was less pronounced in patients with RV infarction (63 +/- 81 vs 455 +/- 417%; p less than 0.002), especially among those with paroxysmal supraventricular tachyarrhythmias. Thus, despite higher baseline plasma levels of ANF, response to volume loading is markedly attenuated in patients with RV infarction complicating an inferior wall acute myocardial infarction.

Adult↗
PubMed1991

Wild-type and e antigen-minus hepatitis B viruses and course of chronic hepatitis.

Using an oligonucleotide hybridization assay, we studied the clinical implication of wild-type hepatitis B virus (HBV) and a HBV mutant that is unable to secrete hepatitis B e antigen (HBeAg) because of a translational defect due to a stop codon in the pre-C region in 106 hepatitis B surface antigen-positive patients with chronic hepatitis B. Wild-type HBV was detected in 31 of 42 (73.8%) HBeAg-positive patients, whereas a mixed viral population was present in 10 (23.8%). Significant differences in the severity and outcome of liver disease were not observed in the two groups of patients. However, the emergence of HBeAg-minus HBV in wild-type HBV carriers was associated with an exacerbation of liver disease and was followed by the presence of antibodies against HBeAg (anti-HBe) in serum in 50% of the cases. In 61 of 64 (95.3%) anti-HBe-positive patients, HBeAg-minus HBV was the predominant virus: HBeAg-minus HBV was detected in 42 patients (65.6%), whereas both wild-type and HBeAg-minus HBV were present in 19 (29.7%). HBeAg-minus HBV was associated with a course of hepatitis characterized by flare-ups of liver cell necrosis interspersed with periods of asymptomatic HBV carriage (P less than 0.01). These data support the hypothesis that genetic heterogeneity of HBV significantly influences the course and outcome of chronic hepatitis B. Wild-type HBV secreting HBeAg induces immunologic tolerance and causes chronic infection. HBeAg-minus HBV might be unable to induce chronic infection without the helper function of wild-type HBV, but it appears to be more pathogenic. Once chronic infection is established, HBeAg-minus HBV variants may prevail and displace wild-type virus.

Adolescent↗
PubMed1991

Xanthogranulomatous pyelonephritis and systemic amyloidosis: report of 2 new cases and the natural history of this association.

The association of xanthogranulomatous pyelonephritis and systemic amyloidosis is extremely rare. To our knowledge, despite innumerable cases of xanthogranulomatous pyelonephritis reported in the literature, this association has been described on only 2 occasions. Clinical, analytical and radiographic findings can be highly suggestive of the diagnosis. We report on 2 patients with xanthogranulomatous pyelonephritis, systemic amyloidosis and the nephrotic syndrome: 1 died 4 1/2 years after diagnosis and 1 was stable with good general health 3 years after diagnosis. The clinical aspects as well as the treatment given to both patients are discussed. We describe the natural history of an association that due to its rarity is not currently well known.

Adult↗
PubMed1991

Concomitant iron and aluminum mass transfer following deferoxamine infusion during hemofiltration.

Variable tissue overloading can alter the removal rate of iron and aluminum from uremics. Owing to its higher affinity to deferoxamine (DFO) and higher plasma concentrations, Fe could impair Al removal in cases of simultaneous body burden. Fe and Al plasma kinetics and mass transfer were therefore studied in 12 uremic patients with different Fe and Al status: six with normal ferritin levels (less than 400 micrograms/L [ng/mL]), and Al 1.4 to 4.7 mumol/L (40 to 131 micrograms/L) (group A); six with increased ferritin (greater than 2,000 micrograms/L), and Al 1.7 to 17 mumol/L (47 to 476 micrograms/L) (group B). DFO (40 and 80 mg/kg in a random sequence) was administered once a week during the first hour of the first hemofiltration (HF). The results show that in both groups and with both DFO doses, maximum Fe and Al mass transfer was achieved in the first and second HF, respectively. The 80-mg/kg dose of DFO significantly raised Al mass transfer in both groups, whereas Fe mass transfer was only slightly affected. Even though plasma Fe levels were almost always higher than Al, Al mass transfer eventually exceeded that of Fe, in both Fe-normal and Fe-overload patients. The bias towards Al in mass transfer was enhanced in both groups in the second HF, and at the higher DFO doses. Thus, DFO once a week reduced Fe loss to less than 30 mumol/wk in patients with normal ferritin levels. In both Fe and Al overloaded patients, Al can be removed, and Al mass transfer may often exceed Fe mass transfer, depending on the degree of tissue burden, the time from DFO infusion, and the DFO dose.

Adult↗