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Biomedical subjects

M A Rubio

Publications and source records attributed to M A Rubio.

17 recordsLinked to original sources

Mapping of the human VLA-alpha 4 gene to chromosome 2q31-q32.

The integrin VLA-4 (alpha 4: beta 1; CD49d/CD29) is involved in both cellular adhesion to extracellular matrix and cell-cell interactions. We have determined that the human gene coding for VLA-alpha 4 is located on the long arm of chromosome 2 by using fluorescence in situ hybridization. The VLA-alpha 4 gene has been more precisely mapped to the 2q31-q32 region after GTG banding (G-bands by trypsin using Giemsa). These data suggest that the VLA-4 gene belongs to the COL3A1-(ELN-FN)-COL6A3 linkage group and establishes a potential genetic relationship between the alpha 4 and alpha v integrin subunits.

Cell Adhesion

First clinical implantation of the BCM 3.5 ventricular assist device (VAD).

We report on the first human implantation of the BCM 3.5 ventricular assist device in a 46-year-old man suffering from terminal stage cardiomyopathy. The circulatory support was used as a bridge to heart transplantation. The patient was in cardiogenic shock and was on assisted circulation for 18 days after which he underwent cardiac transplantation. While receiving support from the ventricular assist device, the patient's condition improved remarkably and 50 days after transplantation he was discharged from hospital. We give a detailed description of the surgical technique, with special emphasis on the procedures for air extraction. We describe the evolution of the hemodynamic status before and after implantation. Final inspection of the device and cannulae after removal showed no thrombi and only small fibrin deposits in the membrane-wall junction.

Cardiomyopathy, Dilated

Bacterial metabolism of side-chain-fluorinated aromatics: unproductive meta-cleavage of 3-trifluoromethylcatechol.

Sixteen bacterial strains capable of degrading alkylbenzenes and alkylphenols were directly isolated from soil and water. The degradation pathways are discussed. Alkylcatechols are almost exclusively cleaved via meta-ring fission. Meta-cleavage of 3-trifluoromethyl-(TFM)-catechol was observed with all strains at different rates although the reaction rates compared to catechol as a substrate varied considerably. All 2-hydroxy-6-oxohepta-2,4-dienoic acid hydrolases investigated showed strong binding of 7,7,7-trifluoro-2-hydroxy-6-oxohepta-2,4-dienoic acid, the ring fission product of 3-TFM-catechol. Turnover rates, however, were negligible indicating this compound to be a general dead-end metabolite during metabolism of TFM-substituted compounds via meta-cleavage pathways.

Bacteria

Blood biochemistry values of sheep (Ovis aries ligeriensis).

1. Analysis of biochemical parameters were carried out on material pooled from 30 female sheep (Ovis aries ligeriensis). 2. The values determined were for the common metabolites and enzymes utilized for specific studies in general metabolism (urea, glucose, cholesterol, lipids, bilirubin, uric acid, creatinine, alkaline phosphatase, GOT, GPT, LDH, LAP, CGT, CK and amylase). 3. Results of these studies were compared with values from normal human adults. 4. The differences obtained in human and sheep ranges can be explained by the different physiology of the two species. 5. This study gives values for the sheep as an experimental animal in biomedical research.

Animals

Prolactin-lowering effect of luteinizing hormone-releasing hormone agonist administration in prolactinoma patients.

We studied the effect of LHRH agonist administration on serum PRL levels in five women with microprolactinomas and two women and a man with intrasellar macroprolactinomas. Each patient received either D-Trp6-LHRH or buserelin for 90 days. Serum PRL levels decreased significantly in the patients with microprolactinomas by 65%, from 156 +/- 93 (+/- SD) to 54 +/- 49 micrograms/L on day 90 (P = 0.011), but it did not decrease in the macroprolactinoma patients. Mean serum LH and FSH decreased by 43% and 62.5%, respectively, in all eight patients. There was no statistically significant correlation between the serum PRL and LH or FSH levels in the microprolactinoma patients. We conclude that LHRH agonists can counteract the hyperprolactinemia produced by microprolactinomas and that the effect probably is not exerted by an action on the gonadotrophs.

Adult

Zinc in adult human serum in Spain.

Zinc levels in serum taken from 1,166 healthy, adult volunteers, from 16 to 70-year-olds living in 10 different districts of the Province of Granada (Spain), have been measured by atomic absorption spectrophotometry. The zinc levels ranged from 80 micrograms to 130 micrograms/100 ml. There were no significant differences with regard to age. The overall results showed higher zinc levels for males than for females but this did not appear when the values for each individual district were analysed separately.

Adolescent

Bacterial metabolism of side chain fluorinated aromatics: cometabolism of 4-trifluoromethyl(TFM)-benzoate by 4-isopropylbenzoate grown Pseudomonas putida JT strains.

Enzymes of the p-cymene pathway in Pseudomonas putida strains cometabolized the intermediate analogue 4-trifluoromethyl(TFM)benzoate. Three products, 4-TFM-2,3-dihydro-2,3-dihydroxybenzoate, 4-TFM-2,3-dihydroxybenzoate and 2-hydroxy-6-oxo-7,7,7-trifluorohepta-2,4-dienoate (7-TFHOD) were identified chemically and by spectroscopic properties. Certain TFM-substituted analogue metabolites of the p-cymene pathway were transformed at drastically reduced rates. Hammett type analysis of ring cleavage reactions of 4-substituted 2,3-dihydroxybenzoates revealed the negative inductive and especially mesomeric effect of substituents to be rate determining. Whereas decarboxylation of 3-carboxy-7-TFHOD was not affected by fluorine substitution the subsequent hydrolysis of 7-TFHOD proceeded very slowly. The negative inductive effect of the TFM-group probably inhibited heterolysis of the carbon bond between C5 and C6 of 7-TFHOD.

Benzoates

D-Trp6-luteinizing hormone-releasing hormone inhibits sulpiride-induced hyperprolactinemia in normal men.

The effect of a potent agonistic analog of LHRH, D-Trp6-LHRH, on hyperprolactinemia induced by sulpiride was studied in normal men. Six men received sulpiride (100 mg, twice daily, orally) for 44 days. D-Trp6-LHRH was given sc during the last 2 weeks of sulpiride administration; the dose was 500 micrograms on the first day and 100 micrograms daily for the subsequent 14 days. All men had high serum PRL levels before D-Trp6-LHRH administration (mean +/- SEM, 56 +/- 9 ng/mL), which decreased significantly after the first dose of the analog (45 +/- 5 ng/mL; P = 0.031) and also after 15 days of analog administration (41 +/- 6 ng/mL; P = 0.016). These data demonstrate that administration of LHRH agonist can inhibit the hyperprolactinemic effect of sulpiride, suggesting a direct action of the analog on the pituitary gland to modulate PRL secretion.

Follicle Stimulating Hormone

Microbial metabolism of chlorosalicylates: accelerated evolution by natural genetic exchange.

Methylsalicylate-grown cells of Pseudomonas sp. WR401 cometabolized 3-, 4- and 5-substituted halosalicylates to the corresponding halocatechols. Further degradation was unproductive due to the presence of high levels of catechol 2,3-dioxygenase. This strain acquired the ability to utilize 3-chlorobenzoate following acquisition of genes from Pseudomonas sp. B13 which are necessary for the assimilation of chlorocatechols. This derivative (WR4011) was unable to use 4- or 5-chlorosalicylates. Derivatives able to use these compounds were obtained by plating WR4011 on 5-chlorosalicylate minimal medium; one such derivative was designated WR4016. The acquisition of this property was accompanied by concomitant loss of the methylsalicylate phenotype. During growth on 4- or 5-chlorosalicylate the typical enzymes of chlorocatechol assimilation were detected in cell free extracts, whereas catechol 2,3-dioxygenase activity was not induced. Repeated subcultivation of WR4016 in the presence of 3-chlorosalicylate produced variants (WR4016-1) which grew on all three isomers.

Biodegradation, Environmental

Microbial metabolism of chlorosalicylates: effect of prolonged subcultivation on constructed strains.

The hybrid strain Pseudomonas sp. WR4016 was subcultivated with increasing concentrations of 5-chlorosalicylate (5----10 mM) as sole carbon source over a period of 9 months. At intervals of approximately 3 months derivative strains WR4017, WR4018 and WR4019 were isolated which exhibited higher growth rates and increased substrate tolerance. Comparative analysis of the turnover rates of the key enzymes in chlorosalicylate degradation showed that the adaptation process did not result from structural modifications of these proteins. Instead, balanced overproduction of the salicylate hydroxylase and catechol 1,2-dioxygenase prevented the accumulation of toxic chlorocatechols and accounted for the reduction of the doubling times with 4- or 5-chlorosalicylate. A comparative analysis of a genetically engineered chlorosalicylate degrader PL300-1 showed similar regulatory patterns as the most advanced isolate WR4019 from the adaptation series.

Biodegradation, Environmental