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Biomedical subjects

R López

Publications and source records attributed to R López.

At least 163 records · Page 9Linked to original sources
PubMed1996

[Erythroblastopenia during recurrence of a thymoma associated with myasthenia gravis. Apropos of a new case].

A new case of thymoma, myasthenia gravis and pure red cell aplasia is presented. Pure red cell aplasia came out 10 years after the diagnosis of the two other diseases in one of several relapses of metastatic thymoma with clinical signs of myasthenia. Surgery, chemotherapy and radiotherapy besides pyridostigmine treatment were used in the clinical course of the patient. A phenotypical change of medullary T lymphocytes (CD4 to CD8) was observed at the same time of pure red cell aplasia diagnosis. A dual role of medullary CD2+ T cell lymphocytes, stimulant and suppressive, over erythroid progenitor cells (BFU-E and CFU-E) was suggested by in vitro cultures.

Aged↗
PubMed1996

Metabolic effects of the combination of furosemide and captopril in rat.

Diuretics typically provoke increased serum lipid levels and may provoke increased serum uric acid levels and/or glucose intolerance. Furosemide is widely used as an antihypertensive, but in patients for whom furosemide treatment alone proves insufficient to reduce hypertension, a common procedure is to co-administer the angiotensin-converting-enzyme (ACE) inhibitor captopril. The metabolic effects in rats of joint administration of furosemide (15 mg/kg/day) and captopril (2 mg/kg/day) are evaluated over a two-week period. At the end of this period, the serum levels of lipids, uric acid, bilirubin, proteins and various enzymes were determined as well as the effect of the treatment on intestinal absorption of glucose and calcium. Furosemide/captopril led to an increase in serum albumin and alkaline phosphatase levels, and a decrease in triglyceride levels. The results of this work support the view that this drug combination is suitable for hypertension treatment.

Alanine Transaminase↗
PubMed1996

Tuberculosis in bone marrow transplant recipients: report of two cases and review of the literature.

Over a 6 year period we have seen two cases of tuberculosis among 118 allogeneic and 237 autologous bone marrow (BMT) or peripheral blood transplants. Both patients had received an HLA-identical related allogeneic BMT. The first case suffered from extensive chronic graft-versus-host disease (GVHD) and developed pulmonary tuberculosis 19 months after BMT. An open-lung biopsy was required to establish the diagnosis, and response to antituberculosis agents was complete, with no relapse at 49 months post-BMT. The second patient received a CD4+ T lymphocyte-depleted BMT, was receiving steroids for acute GVHD and developed rapid-onset meningeal tuberculosis on day +107 post-BMT. Despite initial severe neurologic deterioration, response to antituberculosis agents was good, and she remains alive and well 11 months from BMT. Review of the scant literature on this topic reveals that this is a relatively rare infection in BMT recipients despite their often severely immunosuppressed condition, occurring mainly in recipients of T cell-depleted allogeneic grafts or those who develop GVHD.

Adult↗
PubMed1996

Statistical model fitting Escherichia coli survival data during starvation in artificial sea water.

The survival of Escherichia coli in artificial sea water was studied using linear and nonlinear regression analysis in order to fit the simplest model. The surviving population was evaluated in a rich medium, and two mathematical models, monophase and diphase linear, were considered. The diphase model gave the best fit, although both models can be adjusted to the results obtained. The criteria applied to decide which model was more statistically significant, were residuals, the residual sum of squares and the coefficient of determination. These models are discussed in the light of present day knowledge on survival.

Colony Count, Microbial↗
PubMed1996

[Distal renal tubular acidosis and nephrolithiasis in 3 cases of primary Sjögren syndrome].

Tubulo interstitial nephritis, the main manifestation of renal involvement in Sjögren syndrome, may lead to a tubular dysfunction that is usually subclinical. We report three women, aged 32, 35 and 35 years old, with a primary Sjögren syndrome and symptomatic type I or distal tubular acidosis. Two patients had nephrolithiasis and one a nephrocalcinosis. Two had a basal hyperchloremic metabolic acidosis. The ammonium chloride acidification test was abnormal in all, demonstrating a distal tubular defect. None had proximal tubular dysfunction. All had an urinary pH over 6.5 and hypocitraturia and none had hypercalciuria. Renal calculi were composed of calcium oxalate and calcium phosphate in two patients and calcium phosphate and ammonium phosphate in the other. All women had positive antinuclear antibodies with mottled pattern, two had anti Ro antibodies and positive rheumatoid factor and one had hypergammaglobulinemia. None had anti La antibodies, crioglobulinemia or monoclonal proteins.

Acidosis, Renal Tubular↗
PubMed1995

Sequence and transcriptional analysis of a DNA region involved in the production of capsular polysaccharide in Streptococcus pneumoniae type 3.

The nucleotide (nt) sequence of a 9704-bp EcoRI fragment of Streptococcus pneumoniae (Sp) type-3 DNA has been determined and found to contain one partial and five complete open reading frames (ORFs). One of these ORFs corresponds to the cap3 A gene coding for the UDP-glucose (UDPGlc) dehydrogenase which is directly responsible for the transformation of some unencapsulated serotype-3 Sp mutants to the encapsulated phenotype [Arrecubieta et al., J. Bacteriol. 176 (1994) 6375-6383]. The two ORFs downstream from this gene (cap3B and cap3C) encode proteins with molecular masses of 49 and 34 kDa. Analysis of the deduced amino acid (aa) sequences of Cap3B and Cap3C shows homology to polysaccharide synthases and UDPG1c pyrophosphorylases, respectively. Furthermore, genetic complementation analysis showed that cap3C restored the galU defect of an Escherichia coli mutant. Northern blots have shown that cap3A, cap3B and cap3C constitute a single transcriptional unit, and primer extension analysis has revealed that the transcription start point is preceded by a nt sequence identical to the sigma 70 consensus promoter sequence of E. coli. The sequence upstream from this cluster also has a high degree of similarity with genes postulated to be essential for capsular production in several Gram+ bacteria. However, Northern blot analysis and insertion-duplication mutagenesis indicated that genes located in this region are not necessary for type-3 capsule production in the Sp strain 406.

Amino Acid Sequence↗
PubMed1995

Streptococcus pneumoniae type 3 encodes a protein highly similar to the human glutamate decarboxylase (GAD65).

A 2.5-kb ScaI fragment of the type 3 pneumococcal strain 406 DNA containing a 1425-nucleotide open reading frame (gadA) and encoding a 475-amino acid protein (M(r) 54,427) was characterised. The gene gadA was expressed in Salmonella typhimurium. Pulsed-field gel electrophoresis and Southern blotting analysis of DNAs prepared from several pneumococcal serotypes showed that only those clinical isolates belonging to serotype 3 harbour the gadA gene. Sequence comparison of GadA with proteins included in the data banks revealed the highest similarity with human glutamate decarboxylase (GAD65) (59% similarity, 28% identity). Auto-antibodies to GAD65 have been associated with the onset of insulin-dependent diabetes mellitus. Interestingly, several epitopes of GAD65 that have been identified as immunodominant are particularly well conserved in the pneumococcal GadA.

Amino Acid Sequence↗
PubMed1995

Nucleotide sequence and transcription of the left early region of Streptococcus pneumoniae bacteriophage Cp-1 coding for the terminal protein and the DNA polymerase.

Cp-1 is a small virulent bacteriophage infecting Streptococcus pneumoniae. It has a linear, double-stranded genome of about 19 kb that replicates by a protein-priming mechanism. We have determined the nucleotide sequence of the leftmost 4780 bp of the DNA of this bacteriophage; computer analysis revealed that this fragment contains seven open reading frames (ORFs) which could encode polypeptides containing more than 50 amino acids. The ORFs are clustered in two groups separated by noncoding intergenic regions. Two of these ORFs code for the terminal protein and a specific DNA polymerase that participate in the replication of the DNA. The predicted amino acid sequence of the terminal protein shows significant similarity with the terminal protein of Bacillus subtilis phage phi 29, and Cp-1 DNA polymerase is homologous to the subgroup of eukaryotic-type DNA polymerases that use a protein as a primer. Combined Northern blots and primer extension experiments have allowed us to map the 5' initiation sites of left early transcripts. These studies revealed that transcripts elongate from left to right and identified the left early promoters.

Amino Acid Sequence↗
PubMed1995

Mitomycin, cisplatin, and vindesine followed by radiotherapy combined with cisplatin in stage III nonsmall cell lung cancer: long-term results.

PURPOSE: To assess the tolerance, response rate, pattern of failure, and long-term survival of patients with unresectable nonsmall cell lung cancer treated with one cycle of induction chemotherapy followed by concurrent cisplatin and radiotherapy. METHODS AND MATERIALS: From 1986 to 1988, 45 patients with histologically proven nonsmall cell lung cancer clinical Stage III (29 IIIA and 16 IIIB) were included in this study. Patients received one cycle of Mitomycin C 10 mg/m2 day 1, Cisplatin 120 mg/m2 day 1, and Vindesine 3 mg/m2 days 1, 8, 15, and 22, by i.v. bolus injection. Radiotherapy was started within 4-6 weeks after completion of chemotherapy, with a total tumor dose of 60 Gy, at 2 Gy/day. Cisplatin, 20 mg/m2/day by i.v. continuous infusion was administered for days 1-5 of radiation treatment. RESULTS: The main toxic acute effects were nausea-vomiting grade 1-3 in 38 patients (85%). Ten patients (22%) developed esophagitis grade 3. Leukopenia grade 1-2 was observed in 18 patients (40%), grade 3 in 12 (27%), and grade 4 in 4 (9%). Three patients (6.6%) died by granulocytopenia and sepsis. A bronchoscopic proven complete response was achieved in 9 patients (21.5%) and partial response in 28 patients (67%). With a minimum follow-up of 65 months, overall median survival was 13 months, 2-year survival was 21%, and 5-year survival was 7%, with no statistical difference between Stage IIIA and IIIB. Median survival of patients with complete response was 23.2 months, and 5-year survival was 33%. CONCLUSION: This treatment scheme produced a severe toxicity and in spite of a high response rate, long-term survival is poor, similar to previous studies with radiotherapy alone.

Adult↗
PubMed1995

Factors predictive of response to interferon therapy in children with chronic hepatitis B.

BACKGROUND/AIMS: The efficacy of interferon therapy in Caucasian children with chronic hepatitis B is similar to that in adults. However, little information is available about factors predicting response to this therapy in children. We have performed a univariate analysis to assess the strength of association between basal variables and response, and a multivariate analysis to determine the combination of basal variables which give the best prediction of response in terms of sensitivity and specificity. METHODS: The basal parameters were studied in 50 children included in three different trials of interferon alpha therapy (360-700 MU/square meter of body surface, 2 or 3 times weekly for 12 to 24 weeks). RESULTS: Of these, 18 (36%) were responders. In the univariate analysis, a higher histological activity (p < 0.05), a lower percentage of HBcAg-stained hepatocytes (p < 0.001), aspartate amino transferase and alanine aminotransferase levels (p < 0.05) and alanine aminotransferase peak prior to serum HBV-DNA clearance (p < 0.05), were associated to the response. In the multivariate analysis, the combinations of the percentage of HBcAg stained cells with alanine aminotransferase levels and with the histological activity index were the best variables for predicting response (sensitivity: 100% and specificity: 89% and 86%, respectively). CONCLUSIONS: Factors predictive of response in children with chronic hepatitis B are similar to those found in adults, and may help in identifying those children with a better chance of responding.

Child↗
PubMed1995

Association of increased erythrocyte Na+/H+ exchanger with renal Na+ retention in patients with essential hypertension.

The goal of this study was to investigate the activity of the Na+/H+ exchanger in erythrocytes of patients with essential hypertension and its relation with urinary Na+ excretion. The study was performed in cells from 27 untreated hypertensive patients and 30 normotensive controls with similar age and sex distribution. All subjects were studied after 4 days on a controlled Na+ diet (145 mmol/day). The activity of the Na+/H+ exchanger was determined by acidifying cell pH and measuring the initial rate of the net Na(+)-dependent H+ efflux. The activity of the Na+/H+ exchanger was higher in hypertensive patients than in controls (301 +/- 45 v 162 +/- 23 mmol/L cells/h, mean +/- SEM; P < .01). With the upper limit of the normotensive population as a cut-off point (385 mmol/L cells/h), a subgroup of 12 hypertensive patients had an abnormally high activity of Na+/H+ exchanger. Compared with controls and with patients with normal exchanger activity, patients with increased exchanger activity were characterized by lower net (P < .01) and fractional (P < .05) Na+ excretion. The accumulative Na+ balance was higher (P < .01) in hypertensive patients with increased activity of the exchanger (39.90 +/- 3.47 mmol) than in the remaining hypertensive patients (0.59 +/- 6.96 mmol) or in the normotensive population (-5.71 +/- 6.12 mmol). After analyzing the relationship of renin activity with Na+ excretion it was observed that renin activity was inappropriately low in 9 (75%) patients with increased exchanger, in 6 (40%) patients with normal exchanger, and in 6 (20%) normotensives, these differences being significant (P<.01).

Adult↗
PubMed1995

Presentation of an acquired factor VIII inhibitor with a muscular haematoma mimicking a deep venous thrombosis in a patient with breast cancer.

Acquired haemophilia is a rare disorder that it is associated with several diseases. Patients may present with spontaneous haematomas in different places which can sometimes be fatal. We present a 69-year-old woman with breast carcinoma who developed a factor VIII inhibitor. The initial haemorrhagic event was a spontaneous deep muscular haematoma in the right leg mimicking a deep venous thrombosis. She was successfully treated with prednisone.

Aged↗
PubMed1995

Enhanced Na(+)-H+ exchanger activity and NHE-1 mRNA expression in lymphocytes from patients with essential hypertension.

It has been demonstrated that the activity of the sodium-proton exchanger (NHE-1 isoform) is increased in lymphocytes and other blood cells from patients with essential hypertension. In the present study, we investigated whether an increased level of NHE-1-specific mRNA in lymphocytes from patients with essential hypertension would explain the enhanced transport activity. Twenty-two hypertensive patients and 21 normotensive subjects were studied. Basal cytosolic pH was measured by the pH-sensitive fluorescent probe 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Maximal sodium-proton exchange activity was determined by acidifying cell pH and measuring the initial rate of the net sodium-dependent proton efflux driven by an outward proton gradient. The transcript level of NHE-1 was measured by reverse transcription-polymerase chain reaction in comparison with a constitutively expressed reference gene (beta-actin). Intracellular pH was lower in hypertensive patients than normotensive subjects (7.34 +/- 0.01 versus 7.39 +/- 0.01, mean +/- SEM, P < .001). The maximal activity of the sodium-proton exchanger was higher in hypertensive patients than in normotensive subjects (1262 +/- 100 versus 881 +/- 56 mmol/L cells per hour, P < .01). NHE-1 mRNA was increased in hypertensive patients compared with normotensive subjects (ratio of NHE-1 mRNA to beta-actin mRNA, 0.16 +/- 0.01 versus 0.12 +/- 0.02, P < .05). These data suggest that the increased sodium-proton exchange activity in essential hypertension may be related to the de novo synthesis of exchanger protein.

Actins↗