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L Alonso

Publications and source records attributed to L Alonso.

At least 37 records · Page 2Linked to original sources
PubMed1998

The IL-2/IL-2-receptor complex in the maturation of rat T-cell progenitors.

On the basis of both the interleukin-2-receptor (IL-2R) alpha-chain expression on 16-day-old fetal rat thymocytes and the occurrence of interleukin-2 (IL-2) mRNA-containing cells early during rat thymus ontogeny, we have investigated the possible role of IL-2/IL-2R complex in rat T-cell maturation. For this purpose, we analyzed the effects of the addition of either recombinant rat IL-2 or anti-CD25 (OX-39)-blocking monoclonal antibodies to fetal thymus organ cultures (FTOC), established from 16-day-old rat embryos. IL-2 stimulated the growth of thymocytes and, as a result, induced T-cell differentiation, whereas OX-39 mAb blocked the maturation of thymic-cell progenitors. Accordingly, these results support the involvement of IL-2/IL-2R complex in rat T-cell development.

Animals↗
PubMed1998

[Lactation performance in rural women with low bioavailability of nutrients from the regular diet].

Metabolizable energy (ME) and apparent nitrogen, fat and energy bioavailability from the habitual diet were measured in a group of lactating women from a Mexican rural community. Food intake was estimated in 40 women, age 24 +/- 3 y 3-5 m postpartum, body weight 48.7 +/- 5.4 kg and height 148 +/- 5 cm. Habitual diet was predominantly from vegetable sources based on maize (tortillas), beans, tomato, onion and chili. The daily intake was: 2224 +/- 336 kcal energy, 47.8 +/- 7.0 g protein, 44.7 +/- 11.3 fat and 408 +/- 70 g carbohydrates. Ten women were studied in balance conditions and consuming a controlled diet similar to their habitual diet. ME and apparent energy, nitrogen and fat availability were measured by metabolic balance. Milk output was measured by the test-weighing infant method and milk samples representative of 24-h were obtained for chemical analysis. Apparent digestibility of energy was 87 +/- 1.4%, from nitrogen 68.4 +/- 3.1% and 65.8 +/- 3.7 from fat. Measured ME was 1940 kcal/day. Metabolizable energy from the habitual diet by the marginally nourished lactating group was lower than the energy recommended allowance during lactation. Macronutrient's availability from the habitual diet was similar to that found in population with intake of predominantly vegetable diets and high dietary fiber content.

Adult↗
PubMed1997

Levels of PCDDs and PCDFs in farm cow's milk located near potential contaminant sources in Asturias (Spain). Comparison with levels found in control, rural farms and commercial pasteurized cow's milks.

Cows milk samples from 12 dairy farms in Spain and 23 samples of pasteurised cows milk were analysed for PCDD/F. Farms located in rural areas without specific dioxin sources (background levels) ranged from 1.3 to 2.47 pg TEQ/g fat basis. These values were slightly lower than those found in milk from the vicinity of potential dioxin emission sources (waste incinerator, chemical and metallurgical industry) and similar to milk near paper industry. The waste incinerator seems to be the emission source with the highest influence on the cows milk gathered in its vicinity. Thus, milk near the waste incinerator exhibited the highest PCDD/F levels, the highest PCDF/PCDD ratio and its congener PCDD pattern showed the highest difference respect to its control point. The PCDD/F average concentrations found in pasteurised commercial milk were lower than those found in raw milk and were comparable to those found in retail milk from other countries.

Animals↗
PubMed1997

Interleukin-7 treatment promotes the differentiation pathway of T-cell-receptor-alpha beta cells selectively to the CD8+ cell lineage.

In this report we have studied the influence of interleukin-7 (IL-7) on thymocyte differentiation by evaluating the effects of IL-7 on the generation of T-cell receptor-alpha beta (TCR-alpha beta) and TCR-gamma delta thymocyte subpopulations in rat fetal thymus organ culture. IL-7 enhanced the differentiation pathway of TCR alpha beta thymocytes, first increasing the numbers of immature CD8+ cells, and later those of both CD4+ CD8+ and mature thymocytes. The kinetics of thymocyte migration out of thymic lobes was also accelerated, and the average number of mature TCR-alpha beta phi emigrants per day was increased in the presence of IL-7. Moreover, mature CD4- CD8+ thymocytes were preferentially generated after IL-7 administration. This TCR-alpha beta hi cell population was not actively dividing, indicating that IL-7-promoted thymocyte differentiation was selective to the CD8 cell lineage. Distribution of some TCR-V alpha and TCR-V beta segments among mature thymocytes was also modified in IL-7-treated thymic lobes. On the contrary, the maturation of TCR-gamma delta was not affected by IL-7 addition during the first days of culture, but their numbers sharply increased by day 6 of culture. These results were confirmed with IL-7-treated cultures for 24 hr, showing that IL-7 responsiveness was acquired by TCR-gamma delta cells late in thymus ontogeny. The present results thus indicate a key role for IL-7 in the maturation of TCR-alpha beta thymocytes and the expansion of thymic TCR-gamma delta cells.

Animals↗
PubMed1997

[A non-invasive test choice for the diagnosis of coronary disease in women].

BACKGROUND AND PURPOSE: Regarding coronary heart disease, women have often been excluded from clinical trials. Current practical recommendations are thus based on studies in men. To identify the non invasive technique of choice in detecting coronary artery disease in women, a study with different diagnostic tests has been undertaken. METHODS: Exercise stress test, dipyridamole echocardiography (0.84 mg/kg), dobutamine echocardiography (up to a total dose of 40 micrograms/kg per minute and atropine if necessary), MIBI-SPECT during dobutamine infusion and coronary angiography, were performed in 40 consecutive women with chest pain and no previous history of coronary artery disease. RESULTS: The four tests had similar sensitivity: exercise stress test (80%; CI 95%, 52-94), dipyridamole echocardiography (80%; CI 95%, 56-93), dobutamine echocardiography (80%; CI 95%, 56-93) and scintigraphy MIBI-SPECT (85%; CI 95%, 61-95). The specificity of dipyridamole echocardiography (100%; CI 95%, 83-100) and dobutamine echocardiography (90%; CI 95%, 67-98) was higher than that of exercise stress test (50%; CI 95%, 22-78) and MIBI-SPECT (65%; CI 95%, 41-84). The positive predictive values of dipyridamole and dobutamine echocardiography were 100% and 88% respectively. CONCLUSIONS: The feasibility of exercise stress test in women is inferior to that of the other techniques. The sensitivity of the four tests to diagnose coronary artery disease is similar. The specificity of dipyridamole echocardiography and dobutamine echocardiography is higher than that of exercise stress test and MIBI-SPECT. Stress echocardiography can be considered the non invasive technique of choice for diagnosing coronary artery disease in women.

Aged↗
PubMed1996

16S-23S ribosomal RNA spacer regions of Acetobacter europaeus and A. xylinum, tRNA genes and antitermination sequences.

The 16S-23S ribosomal RNA spacer regions of Acetobacter europaeus DSM 6160, A. xylinum NCIB 11664 and A. xylinum CL27 were amplified by PCR. Specific PCR products were obtained from each strain and their nucleotide sequences determined. The spacer region of A. europaeus comprises 768 nucleotides (nt), that of A. xylinum 778 nt and that of A. xylinum CL27 759 nt. Genes encoding tRNAIle and tRNAAla were identified. Putative antitermination sequences were found between the tRNAAla sequence and the 5'-terminus of the 23S rRNA coding sequence. The boxA element has the nucleotide sequence TGCTCTTTGATA. Based on hybridization data of digested chromosomal DNA with spacer-specific probes, the copy number of the rrn operons on the chromosome of Acetobacter strains is estimated to be four.

Base Sequence↗
PubMed1996

Cisplatin, 5-fluorouracil, and high-dose folinic acid in patients with advanced unresectable head and neck cancer.

For patients with advanced, unresectable head and neck (HN) cancer, surgery and/or radiotherapy are the standard treatments but have poor results. A phase II trial of a continuous infusion of cisplatin, 5-FU, and high dose folinic acid (PFL) as induction chemotherapy in patients with previously untreated, locally advanced HN cancer was performed in an attempt to confirm the encouraging results reported by Dana Farber investigators using an identical regimen. Forty-five consecutive patients with unresectable HN cancer were treated every 28 days with a continuous infusion of cisplatin 25 mg/m(2)/day (days 1-5), 5-FU 800 mg/m(2)/day (days 2-6), and folinic acid 500 mg/m(2)/day (days 1-6). After three courses of chemotherapy, patients were treated with surgery and/or radiotherapy. Objective responses were observed in 26 of 38(69%) evaluable patients with 14(37%) clinical complete responses. Grade III-IV toxicity was important and consisted mainly of mucositis and neutropenia that were found in 47 and 18%, respectively , of patients after the first course. There was one toxic death. PFL is an active, toxic induction regimen for far-advanced HN cancer, yielding a response rate in the range of the widely used cisplatin and 5-FU (PF) schedule; a comparative trial is warranted before concluding that PFL is superior to the latter combination.

Adult↗
PubMed1996

Clinical and genetic aspects of two Spanish families with autosomal dominant retinitis pigmentosa (ADRP)

A study was made of two families with autosomal dominant retinitis pigmentosa (ADRP) from Valencia (Spain). One family (ADRP15) was found to have mutation in codon 114 of the rhodopsin gene that led to a substitution of a glycine for an aspartic acid. The second family (ADRP7) substituted an aspartic acid for valine in codon 173 of the peripherin-RDS gene. Rhodopsin is involved in 25% of ADRP cases and many mutations of this gene have been described as causing different forms of the disease, with variable severity and age at onset. ADRP has been classified as RP with a milder symptom evolution, a typical RP fundus pattern, and macular involvement occurring after the second decade of life. Peripherin-RDS gene mutations lead to RP or other retinopathies. Furthermore, two mutations in codon 172 have been described as causing macular dystrophy. In ADRP7, a mutation in neighboring codon 173 produced RP with an atypical fundus pattern and macular involvement within the first decade of life. These observations confirm the established clinical and genetic heterogeneity involved in this form of RP.

Adolescent↗
PubMed1996

[Morphological and quantitative analysis of the mechanism of balloon angioplasty. An intravascular ultrasonic study].

BACKGROUND AND OBJECTIVES: Intracoronary ultrasound allows to study in vivo the morphology of the arterial wall, the presence and composition of atheroma and the associated lumen encroachment. The objective of our study was to assess the value of intravascular ultrasound to determine the dilatation mechanism after a conventional balloon angioplasty. PATIENTS AND METHODS: Sixteen patients were examined with intravascular ultrasound before and after they had undergone percutaneous transluminal coronary angioplasty. A mechanical intravascular ultrasound system was used. Two different types of imaging catheters were used in this study: a 20 MHz, 4.8 F catheter in 5 patients and a 30 MHz, 3.5 F in 11 patients. RESULTS: Quantitative and qualitative assessments were made from the angiograms and the ultrasound images. Seven out of 16 patients had a calcified plaque, in 8 patients the plaque was fibrotic and in 1 patient soft. Rupture of the plaque was the most common dilatation pattern. Post-PTCA the cross-sectional arterial area was increased from 15.3 +/- 5.2 mm2 to 17.3 +/- 6.2 mm2, the intraluminal area was increased from 2.7 +/- 2.5 mm2 to 7.3 +/- 3.4 mm2, and the plaque area was reduced from 12.3 +/- 4.8 mm2 to 9.7 +/- 3.4 mm2. The quantitative analysis showed that the "most frequent dilatation mechanism" found was the reduction of size plaque, an increase in cross-sectional arterial area was present in only 4 patients (25%). The incidence of depth rupture of the plaque was greater in patients with a calcified plaque than in those without (NS). CONCLUSIONS: 1). Intracoronary ultrasound provides a complete description of plaque composition and geometry before and after coronary balloon angioplasty; 2) several morphologic dilatation patterns were found, and plaque tearing was the most common, and 3) increase in luminal area was most frequently due to a reduction in plaque area. Nevertheless an increase in the cross-sectional arterial area was also common, but less important.

Aged↗
PubMed1995

Extraction of ewe's milk cream with supercritical carbon dioxide.

The extraction of ewe's milk cream by supercritical carbon dioxide in the pressure range 9-30 MPa (90-300 bar) and at temperatures of 40 degrees C and 50 degrees C was studied. The solubility of total fat increased with pressure at both temperatures until a plateau was reached. The extraction of cholesterol also increased with pressure until a plateau was reached and it was higher at 50 degrees C than at 40 degrees C when the pressure was > or = 15 MPa (150 bar). The triglyceride composition of each extract, determined by GC, showed that extracts obtained at lower pressures were enriched in short-chain triglycerides and their concentration decreased as the pressure increased. In the other hand, long-chain triglycerides were enriched in the extracts obtained at higher pressures and their concentration rose with increasing pressure.

Animals↗
PubMed1995

Changes in the blood-thymus barrier of adult rats after estradiol-treatment.

The accessibility of the thymus parenchyma for relatively large Mw (+/- 150 Kd) proteins has been studied by the intravenous injection of monoclonal antibodies (mAbs) specific either for all T cells (His-17) or MHC class II molecules (His-19) in control and estradiol benzoate (EB)-treated adult Wistar rats. In controls, the transcapsular route rather than cortical capillaries seems to be involved in the entry of molecules into the thymus. By contrast, a specific staining for either T cells (His-17) or MHC class II molecules (His-19 positive cells) disappears almost completely from the thymic cortex of EB-treated rats except in the immediate subcapsular epithelial cell layer. In these rats, T cells and epithelial cells intimately associated to blood vessels from both inner cortex and corticomedullary border showed additional staining with the respective mAbs confirmed by electron microscopy. The disappearance of the transcapsular route together with the increased vascular permeability of cortical blood vessels would be related to the reinforcement of the subcapsular epithelial cell layer and to direct effects of EB on vascular endothelia, respectively. These results are discussed in relationship to the cell migration into and out of adult thymus, as suggested by the changes in intrathymic T cell subsets evaluated by flow cytometry.

Animals↗
PubMed1995

Protein requirements of marginally nourished lactating women.

Few experimental data regarding protein requirements of lactating women are available. This study was designed to determine the protein requirement of seven healthy lactating women from a poor Mexican community who were 2-6 mo postpartum and had a mean body mass index of 21.8 +/- 2 kg/m2. Nitrogen balances were performed at intakes of 0.8, 1.0, and 1.2 g.kg body wt-1.d-1 of a mixed protein diet (70% derived from vegetable sources). A balance at 1.2 g.kg body wt-1.d-1 of a high-quality mixed protein (80% from animal sources) was the reference. The experimental diets were designed to resemble the habitual diet in terms of energy and macronutrients. The balance responses to nitrogen intake were -35.5 +/- 12.6, -10.5 +/- 14.8, and 7.8 +/- 19.2 mg N.kg body wt-1.d-1, respectively. Equilibrium balance was attained at 178.9 +/- 25.8 mg N (1.1 g protein.kg body wt-1.d-1), close to current recommended dietary allowances, albeit the dietary protein was mostly from vegetable sources.

Adolescent↗