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Biomedical subjects

A Soler

Publications and source records attributed to A Soler.

At least 55 records · Page 3Linked to original sources
PubMed1995

Chorionic villus sampling by biopsy forceps. Results of 1580 procedures from a single centre.

The results of a prospective series of 1580 chorionic villus sampling (CVS) procedures using biopsy forceps are presented. Most of the procedures (1442), including 11 sets of twins, were performed by the transcervical approach (TC-CVS), using a curved-shank thin forceps, and 138 by the transabdominal approach (TA-CVS), using a trocar-guided straight thin forceps. The mean gestational age for TC-CVS was 10.9 weeks, and in 233 cases (16 per cent) the procedure was carried out between the 12th and 14th weeks. The mean gestational age for TA-CVS was 16.7 weeks. The major indication for CVS was advanced maternal age (92.7 per cent in the TC and 91.8 per cent in the TA approach), and indications for abnormal ultrasound findings were more common in the TA approach (4.5 per cent) than in TC-CVS (0.07 per cent). Although sampling was apparently accomplished in all the procedures, in 3.1 per cent of the TC-CVS and 2.2 per cent of TA-CVS procedures, the samples were less than 1 mg after dissection. A cytogenic report was obtained in 96.1 per cent of the TC-CVS and 90.6 per cent of the TA-CVS. Maternal serum alpha-fetoprotein (MSAFP) was measured before and after TC-CVS and the post-CVS MSAFP was positively correlated with the sample weight. Second-trimester amniocentesis following CVS was required in 5.2 per cent (TC-CVS) and 6.5 per cent (TA-CVS), due to the failure to obtain a cytogenetic report or diagnostic confirmation. The follow-up to the 20th week was 100 per cent by ultrasound scan, and 88.6 per cent from the 21st week to 1 week after delivery. Fetal loss rates within 2 weeks of the procedure were 1.7 per cent (TC-CVS) and 0.8 per cent (TA-CVS) and total fetal loss accumulated to 1 week after delivery was 4.6 per cent (TC-CVS) and 5.9 per cent (TA-CVS). Factors found to increase significantly fetal loss in the TC-CVS series were maternal age and the collection of very small samples, but not the number of forceps insertions.

Adult↗
PubMed1995

Prenatal diagnosis of fragile X syndrome: (CGG)n expansion and methylation of chorionic villus samples.

Fragile X syndrome is the most common form of inherited mental retardation, due to an expansion of the (CGG)n trinucleotide repeat in the FMR-1 gene and hypermethylation of its 5' upstream CpG island. Two major problems remain to be resolved for fragile X prenatal diagnosis: the abnormal methylation patterns of chorionic villus samples (CVS) and the inability to predict the mental status of females with the full mutation. We present here the results of ten prenatal diagnoses of fragile X syndrome using Southern blotting and polymerase chain reaction (PCR) amplification, and the analysis of 50 further CVS to test the methylation status of the CpG island of the FMR-1 gene. In the ten 'at-risk' CVS, eight normal (five males and three females) and two affected male fetuses were detected. Absence of methylation in the CVS was observed in two cases, which was not found upon subsequent examination of the newborn or of fetal tissues. In the 50 CVS not 'at risk' for fragile X syndrome, abnormal fragment patterns for probe StB12.3 were detected in 32 per cent for female and 24 per cent for male fetuses. This abnormal pattern could be due to absent or partial methylation of the CpG island of the FMR-1 gene in chorionic villus tissues.

Blotting, Southern↗
PubMed1995

Site of origin of an urinary Na-K-Cl cotransport inhibitor.

We investigated the site of origin of a potent inhibitor of the Na-K-Cl cotransport system (CIF), which has been previously identified in urines from salt-loaded rats. Rats were given a 2% NaCl solution to drink for 15 and 60 days and the plasma was obtained and tested for cotransport inhibitory activity (on bumetanide-sensitive Li+ efflux in Li-loaded human erythrocytes) in dose-response curves. The IC50 for cotransport inhibition (vol:vol dilution reducing cotransport activity by 50%) was found to be 26.5 +/- 7.2 (mean +/- SEM, n = 5) and 6.9 +/- 0.7% (n = 10) on days 15 and 60, respectively (control samples, day 0, only inhibited about 20% cotransport activity at a 30% plasma vol:vol dilution, n = 7). Organ extracts from salt-loaded rats were prepared and tested for cotransport inhibitory activity. A statistically significant cotransport inhibitory activity was only found in pituitary extracts (-36 +/- 3 vs. -5 +/- 4% in control rats, n = 4, p < 0.01). Dissection of a large number of pituitary glands from salt-loaded rats revealed CIF activity only in the neurohypophysis (cotransport inhibition -46.5 +/- 5.2 vs. -0.5 +/- 16.4% in the anterior lobe, n = 4, p < 0.05). In conclusion, CIF is a new circulating endogenous factor, probably secreted by the neurohypophysis.

Adrenalectomy↗
PubMed1994

Inhibition of Na-K-Cl cotransport fluxes and salidiuretic action by an urinary extract of salt-loaded rats.

We previously found a potent inhibitor of the Na-K-Cl cotransport system in urines from salt-loaded rats (C.I.F. = cotransport inhibitory factor, ref. 1). Here we extracted an urinary fraction (approximately 1% urine dry weight), free from immunoreactive A.N.P. and digoxin activity, which: (i) potently inhibited cotransport fluxes in MDCK (Madin and Darby canine kidney] cells and in human erythrocytes, (ii) inhibited Na(+)-dependent chloride/bicarbonate exchange with 2-3 times less potency than cotransport and (iii) strongly increased natriuresis and diuresis after i.v. infusion in rats with no significant change in kaliuresis (salidiuretic action reduced by probenecid). Therefore, C.I.F. seems to be a new natriuretic factor with part, but not all the biological profile of loop diuretic drugs.

Animals↗
PubMed1994

Audit of uterine rupture in Maputo: a tool for assessment of obstetric care.

Records of 96 women who had rupture of the uterus in labor were audited to find circumstances significantly associated with pregnancy outcome. The prevalence was 1 rupture in 424 deliveries. In 74 cases (77.1%) uterine rupture occurred after hospitalization, the remaining 22 cases being emergency transfers with rupture secondary to a delivery attempt elsewhere. History of a previous cesarean section was present in 46%, whereas 54% of the women had an unscarred uterus. Maternal mortality was 7.3% whilst perinatal mortality was 62.9%. Adverse outcome for the mother was associated with ruptures occurring in unscarred uteri (p < 0.02) and outside the Maternity (p < 0.01); this latter condition also contributed to higher fetal mortality (p < 0.002). The findings confirm that delay in reaching medical care is an aggravating factor in the evolution of uterine rupture in developing countries and suggest the need for better medical attention and timely diagnosis in laboring women with unscarred uterus.

Adolescent↗
PubMed1994

[A new natriuretic factor acting like loop diuretics. Kinetics in normal and hypertensive rats].

We have recently described that urines from salt-loaded rats contain a potent natriuretic factor acting at the Na-K-Cl cotransport system (CIF: "Cotransport Inhibitory Factor"). Here we investigated the kinetics of the urinary CIF excretion which follows an oral salt-load: (i) in normal rats, relative to that of the atrial natriuretic peptide (ANP) and (ii) in an experimental model of salt-dependent genetic hypertension (Dahl's rats). Thus, Wistar rats were orally loaded with 2% NaCl for 8 days. Urinary CIF excretion was measured by testing the inhibitory potency of urines on bumetanide-sensitive lithium efflux in lithium-loaded human erythrocytes. Plasmatic levels of ANP were measured by radioimmunoassay. Plasma ANP rapidly and transiently increased during the first 24 hs of salt-load, decreasing thereafter down to normal levels in 6-8 days. Conversely, CIF slowly increased after 24 hs up to maximal constant levels after 5 days of salt-loading. Dahl salt-sensitive rats exhibited highly significant increases in urinary CIF excretion with respect to salt-resistant rats. In the basal state (before salt-loading) urinary CIF excretion was 101 +/- 13 vs 17.6 +/- 4.5 units/day in salt-sensitive vs. salt-resistant rats (n = 7 for each group, p < 0.001). This difference was maintained after salt loading (3 380 +/- 990 vs. 456 +/- 159 units/day, p < 0.05 at day 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Unusual segregation for 11q;22q parental translocation in a triplet pregnancy: prenatal diagnosis in chorionic villi and amniotic fluid.

The prenatal diagnosis of an 11q;22q translocation in a triplet pregnancy detected at the time of chorionic villus sampling (CVS) because of advanced maternal age is reported. Karyotypes obtained from two apparently different CV samples showed the balanced form of translocation, while the one obtained from a third empty sac showed the unbalanced form: 46,XX,-22,+der(22)t(11;22). Second-trimester amniocentesis confirmed the balanced translocation in one of the two viable fetuses and a normal karyotype in the other. The detected karyotypes derived from two different types of meiotic segregation, alternate and adjacent 1. To our knowledge, this is the first reported case of an unbalanced karyotype not due to a 3:1 meiotic segregation of this specific translocation.

Adult↗
PubMed1993

Volume-dependent K+ and Cl- fluxes in rat thymocytes.

1. Hypotonic stress unmasked inward and outward K+ and Cl- movements in rat thymocytes. This KCl flux stimulation was reduced by DIOA (dihydroindenyl-oxy-alkanoic acid), but not by DIDS (4,4'-diisothiocyanostilbene-2,2'-disulphonate), quinidine, DPAC 144 (5-nitro-2-(2-phenylethyl-amino)-benzoic acid), bumetanide or ouabain. 2. In isotonic media (308 +/- 5 mosmol kg-1), the cells exhibited the following DIOA-sensitive fluxes: (i) a K+ efflux of 42.7 +/- 17.1 mmol (l cells.h)-1 (mean +/- S.D., n = 7), (ii) a Cl- efflux of 68 +/- 21 mmol (l cells.h)-1 (n = 3), (iii) a Rb+ influx of 9.7 +/- 3.9 mmol (l cells.h)-1 (n = 6) and (iv) a Cl- influx of 9.4 +/- 4.1 mmol (l cells.h)-1 (n = 6). 3. Hypotonic shock (183-200 mosmol kg-1) induced a sevenfold stimulation of DIOA-sensitive K+ and Cl- effluxes and a twofold stimulation of DIOA-sensitive Rb+ and Cl- influxes (with a Rb+ to Cl- stoichiometry of 1.04 +/- 0.31; mean +/- S.D., n = 6). 4. The DIOA-sensitive membrane carrier catalysed net outward KCl extrusion (the outward/inward flux ratio was 5-7 in isotonic media and 20 in hypotonic media at 189 mosmol kg-1). Inhibition of DIOA-sensitive 36Cl- efflux by cell K+ depletion suggested coupling of outward K+ and Cl- fluxes. Conversely, inward K+ and Cl- fluxes were found to be uncoupled in NO3- media and in K(+)-free media. 5. The results clearly show that rat thymocyte membranes possess a 1:1 K(+)-Cl- co-transport system which is strongly activated by hypotonic shock and catalyses net KCl extrusion.

Animals↗
PubMed1993

Cell volume regulation in rat thymocytes.

1. DIOA (dihydroindenyl-oxy-alkanoic acid), a potent inhibitor of the K(+)-Cl- co-transport system, fully blocked regulatory volume decrease (RVD) in swelled rat thymocytes, with an IC50 of 2.2 +/- 0.5 x 10(-5) mol l-1 (mean +/- S.D., n = 4). Conversely, RVD was resistant to quinine, quinidine, apamin, cetiedil, amiloride, bumetanide and DIDS (4,4'-diisothiocyanostilbene-2,2'-disulphonate). 2. DIOA-sensitive RVD followed mono-exponential kinetics, with t1/2 (half-lifetime) of 1-3 min and maximal capacity (Cmax) of about 55% of the initial cell swelling. Cmax and the initial rate of RVD (Vo) were both linear functions of the increase in cell volume. 3. RVD was: (i) slightly increased by replacing external Cl- by NO3-, (ii) reversed by replacing external Na+ by K+ (in the presence of external Cl-) and (iii) inhibited by cell K+ depletion. All these phenomena were blocked by DIOA (86 mumol l-1). 4. Increased membrane potassium permeability by valinomycin was unable to accelerate RVD or RVD reversal. 5. In the presence of DIOA, thymocytes responded like osmometers (the relative cell volume was a linear function of the reciprocal of the relative osmolality) in a large range of osmolalities. 6. The results strongly suggest that RVD in rat thymocytes is mediated by the K(+)-Cl- co-transport system.

Animals↗
PubMed1992

Investigation of an outbreak of nosocomial infection due to a multiply drug-resistant strain of Pseudomonas aeruginosa.

A nosocomial outbreak of Pseudomonas aeruginosa infections which occurred in the Urology Service of a large city hospital was studied. A case-control methodology was used to analyse patients' characteristics and the main risk factors of all cases with a positive culture during the period between March 1987 and March 1988. The usefulness of factor analysis in the definition of a case was examined. There were 74 infections of which 35 (47.3%), had a nosocomial origin. The outbreak took place in December 1987, with a peak incidence of infections of 10.5%, compared with a 2.2% frequency during the preceding months (P less than 0.005). Six of the nine infections occurring in that month, were caused by strains resistant to ticarcillin and gentamicin. The epidemic cases had longer hospital stays than the non-epidemic cases (P less than 0.038) and occurred more frequently in a specific area of the hospital (P less than 0.001). The odds ratio for resistance to gentamicin was 15 (P less than 0.018) and that of resistance to ticarcillin, 127 (P less than 0.0001). Our results suggest that inaccurate case definitions may produce misleading conclusions. Factor analysis appears to be a useful analytical tool when defining a case.

Case-Control Studies↗
PubMed1992

[Can we do without bone gammagraphy in the staging of prostatic cancer?].

Correlation between findings on bone gammagraphy and PSA levels in 144 patients with untreated prostate cancer are analyzed. With prevalence of metastatic disease in 57.6% cases and considering the predictive cut value of metastasis to be 20 ng/ml, there were positive and negative predictive values of 64.9% and 73.9%, with a diagnostic confidence of 66.6%. We conclude that bone gammagraphy is essential for staging prostate cancer even in patients with PSA below 20 ng/ml.

Bone Neoplasms↗
PubMed1989

Effects of K+-canrenoate on the development of DOCA-salt hypertension.

The effects of K+-canrenoate, a digoxin antagonist, on the role of digoxin-like factor in the development of DOCA-salt hypertension has been examined. DOCA-salt rats treated with 66 mg kg-1 day-1 of K+-canrenoate (s.c.) presented a lower increase in blood pressure (P less than 0.01), less cardiac hypertrophy (P less than 0.05) and hypokalaemia (P less than 0.05) than non-treated DOCA-salt rats. K+-canrenoate treatment did not lead to significant changes in urinary volume, Na+ and K+ urinary excretion or suppression of plasma renin activity in DOCA-salt rats. None of the parameters were significantly different between uninephrectomized-salt rats treated or non-treated with K+-canrenoate. These data suggest a role for digoxin-like factor in DOCA-salt hypertension. However, the non-normalization of blood pressure observed in K+-canrenoate DOCA-salt treated rats indicates that other factors contribute to the initiating mechanisms in this type of hypertension. Moreover, these data suggest that digoxin-like factor plays no role in the suppression of plasma renin activity induced by DOCA and salt treatment.

Animals↗
PubMed1989

beta-adrenergic reactivity in conscious DOCA-salt hypertensive rats.

The endocrine (plasma renin activity, insulin and ADH) and hemodynamic responses (heart rate and mean arterial pressure) to isoprenaline infusion were examined in conscious deoxycorticosterone-salt hypertensive rats (DS) and compared with uninephrectomized-salt control rats (US). A dose-related rise in plasma renin activity and plasma insulin values was found in US rats, while no change in either parameter was observed in DS rats after 30 min of isoprenaline infusion. ADH was not increased in US rats at any dose of isoprenaline infusion. However, in DS rats the largest dose (450 ng/kg/min) produced a significant rise. Isoprenaline infusion increased the heart rate in both groups, but the increases in the DS group were significantly lower than in the US group for the 200-ng/kg/min dose (p less than 0.01). The drop in mean arterial pressure was found to be more pronounced in DS rats than in US rats at 50, 100 and 200-ng/kg/min isoprenaline doses. Recovery of the mean arterial pressure to basal levels was also found in US rats with the various doses of isoprenaline administered. However, in DS rats the different doses of isoprenaline produced a progressive drop in mean arterial pressure with no recovery at the end of 30 min of isoprenaline infusion. The present results provide no evidence of subsensitivity to isoprenaline in the resistance vessels of conscious DS rats and suggest that the greater hypotensive response observed in these rats may be due to the inability of the renin-angiotensin system to adequately compensate the vasodilation produced by isoprenaline.

Animals↗
PubMed1988

Detection of balanced chromosome rearrangements in 445 couples with repeated abortion and cytogenetic prenatal testing in carriers.

Cytogenetic studies were performed in 445 couples presenting because of repetitive abortion. The authors detected a balanced translocation in 19 (4.2%) of the couples, pericentric inversions in 8 (1.8%), and polymorphisms in 52 (11.4%). The results were compared with those obtained in a series of 600 consecutive normal liveborns. Significantly higher frequencies for translocations and polymorphisms were present in couples with repetitive abortion. No sex predominance in translocation carriers was observed, and reciprocal translocations were more common (16 of 19) than the robertsonian type (3 of 19). Contrary to other reports, all of the translocations and inversions were detected among couples without previous abnormal offspring. Cytogenetic prenatal testing in 17 pregnancies from a carrier parent showed that none of the fetuses had the unbalanced karyotype, 13 carried the balanced rearrangement, and 4 had a normal karyotype. Although a risk profile can be obtained for these couples, prenatal testing must be offered to avoid anxiety and unjustified pregnancy interruptions.

Abortion, Habitual↗
PubMed1988

H Cotransports in Corn Roots as Related to the Surface pH Shift Induced by Active H Excretion.

The surface pH shift induced by active H(+) excretion in corn (Zea mays L.) roots was estimated using acetic acid influx as a pH probe (H Sentenac, C Grignon 1987 Plant Physiol 84: 1367-1372). At constant bulk pH, buffering the medium strongly reduced the magnitude of the surface pH shift. This was used to study the effect of surface pH shift on H(+) cotransports. In the absence of buffers, the surface pH shift increased with the bulk pH. Buffers decreased (32)Pi influx and this effect was stronger at pH 7.2 than at pH 5.8, and stronger in the absence than in the presence of an inhibitor of the proton pump (vanadate). Buffers exerted a similar depressive and pH-dependent effect on net NO(3) (-) uptake. They hyperpolarized the cell membrane, and stimulated (86)Rb(+) influx, K(+):H(+) net exchange, and malate accumulation. These results are consistent with the hypothesis that H(+) accumulation at the cell surface is effective in driving H(+) reentry. We concluded that the surface pH shift due to proton pump activity is involved in the energetic coupling of H(+) cotransports.

Journal Article↗
PubMed1986

H and k electrogenic exchanges in corn roots.

The membrane potential difference, the net H(+) exchange rate, the K(+) net flux, and the K(+) ((86)Rb(+)) influx were measured in excised corn roots as functions of the K(+) concentration in the medium at various pH values, in the presence of poorly permeant anions. The roots behaved as a K(+)/H(+) exchange system. By comparing the results in normal or hypoxic conditions, or in the presence of vanadate, it was possible to distinguish the active components of membrane potential and transports from the passive ones. The magnitude of the electrogenic potential was not related to the active H(+) extrusion rate. At pH 6, the variations of the electrogenic potential resulted from variations of the stoichiometry of the active H(+)/K(+) exchange. The same relationship between this stoichiometry and the K(+) concentration was observed in conditions ensuring different membrane polarizations (pH 6, pH 4, or pH 6 with fusicoccin). Both metabolic and Mg-ATPase specific inhibitors stopped the active H(+) transport and the net K(+) influx. Nevertheless, the tracer influx in the presence of vanadate remained higher than the passive influx calculated from the permeability coefficient determined in hypoxia. It is proposed that vanadate uncouples the K(+) moiety of the H(+)/K(+) antiport and allows it to mediate isotopic exchanges.

Journal Article↗