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Biomedical subjects

A Navarro

Publications and source records attributed to A Navarro.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Multicenter study of atenolol, combined with hydralazine and bendroflumethiazide in the treatment of essential, mild, and severe, arterial hypertension].

The aim of the present study was to determine both the effectiveness and tolerance of a preparation constituted by the combination at fixed doses of a betablocker (atenolol, 100 mg), a diuretic (bendroflumethiazide, 5 mg) and a vasodilator (hydralazine, 50 mg). The study was carried out on a sample formed by 46 patients with moderate or severe essential hypertension who received this preparation as a single antihypertensive therapy during 2 months. As for the hypotensive effectiveness of the product, obtained results demonstrate that arterial blood pressure (BP) levels were normalized in 89% of the patients with moderate essential hypertension and in 9/10 patients with severe hypertension. Tolerance was excellent in most of the cases. Although new studies should be performed in order to enlarge the number of available case-studies, the above presented data allow us to conclude with a positive opinion about the studied combination.

Adult↗
PubMed1989

[The state of muscle cramp disease].

A 65-year-old man presented with daily, almost continuous muscle cramps and painless muscle contractions eight years after being diagnosed as having rheumatoid arthritis. Both cramps and contractions were present at rest, were accentuated by stress and disappeared during sleep. By night-fall the patient was plunged into an extremely disabling condition due to the continuous cramps present in the orofacial, trunk, neck and limb musculature. He even had difficulty speaking. EMG studies demonstrated that both cramps and painless contractions appeared synchronously in muscles innervated by different peripheral nerves. A state of central hyperexcitability is the probable cause of this clinical picture which has remained unchanged over the last six years.

Aged↗
PubMed1988

New technique for differential staining of myelinated fibers and nerve cells on paraffin sections.

A simple, rapid method for the differential staining of myelinated nerve fibers and nerve cell bodies, applicable to sections of central nervous system pieces embedded in paraffin, is described. Experimental material fixed by perfusion with mixed aldehydes or necropsy material fixed in formaldehyde can be used. Constant and homogeneous results are obtained with this technique, and the most important characteristic is the absence of differentiation in either of the steps: staining of myelinated fibers and staining of nerve cell bodies. Sections 15 microns thick were attached to slides, dewaxed, and hydrated. After hydration, sections are mordanted (30 min) in 2.5% iron alum (SO4)2FeNH4, and rinsed (1 min) in distilled water. Staining is for 180 min in the following solution: 5 ml freshly made 20% alcoholic hematoxylin diluted with 25 ml of distilled water and 25 ml of absolute ethanol to which 10 ml of 1% Li2CO3 is added. The sections are washed in distilled water (5 min) and stained during 5 min in the following solution: 0.2% pyronine, 20% formaldehyde in distilled water. The sections are dehydrated through 96% and absolute ethanol, cleared in eucalyptol, and mounted in Eukitt. Myelinated fibers appear dark blue, whereas nerve cell bodies are stained red and the cell nucleoli dark blue. This procedure provides an adequate contrast for observation and photography.

Animals↗
PubMed1987

Late onset parkinsonian syndrome in Hallervorden-Spatz disease.

Two siblings, from consanguineous parents, developed in their twenties a Parkinsonian syndrome. In the elder, the disease evolved for 13 years and the necropsic study was diagnostic of Hallervorden-Spatz disease. The younger sibling is severely affected after 12 years of the disorder. Several CT and one MR studies done in this patient during the last 4 years have been normal. Ultrastructural studies of the bone marrow histiocytes and blood lymphocytes disclosed peculiar inclusions. Bromocriptine in low doses proved to be a beneficial therapy for this patient.

Adult↗
PubMed1986

Thromboelastographic assays of the clotting process in situations of obesity and caloric restriction.

A study on blood clotting has been carried out in a number of obese individuals and compared to a group of non-obese persons, in order to assess if the former can be considered to be in "high risk" regarding the onset of a thromboembolic process. The technique of thromboelastography was chosen. The results point out that in obese people a series of alterations take place, both in the time of clot formation, which is enlarged, as in the organization of its nets, which appear strongly structured, favoured by the hyperfibrinogenemia and thrombocytosis detected in these subjects. Likewise, the effect of a hypocaloric diet on clotting in obese persons has been evaluated and compared with the former groups. Clotting in treated obese individuals is modified in the same way as in the untreated group when compared to the non-obese population; nevertheless, when both groups of obese people are compared, no significant difference is observed in the different parameters studied, even though constants determined in citrated whole blood are closer to normality in the subjects undergoing caloric restriction.

Adolescent↗
PubMed1985

Purine nucleotides stimulate while carbamoyl phosphate protects inactivation of ornithine transcarbamoylase by disrupted lysosomes.

Ornithine transcarbamoylase (OTC) is inactivated by liver lysosomes. Carbamoyl phosphate prevents the inactivation of OTC by lysosomes, while ATP, ADP, GTP, GDP 1,N6-ethenoadenosine 5'-triphosphate and particularly epsilon-ATP stimulate it. Both stimulation and protection occur at concentrations within the physiological range of ATP and carbamoyl phosphate. Inactivation of OTC is followed by extensive proteolysis. Since the inactivation is prevented by leupeptin, antipain and L-(tosylamido-2-phenyl)ethylchloromethyl ketone, the proteolytic susceptibility of OTC to lysosomes could be due to thiol endopeptidase(s). 1,N6-Ethenoadenosine 5'-triphosphate also markedly increases OTC susceptibility to trypsin and elastase. ATP analogs had no stimulatory effect on OTC inactivation by lysosomes; none of the inhibitors of ATPases tested inhibited the ATP effect. The ATP stimulation does not require Mg2+. These findings indicate a new role for ATP, GTP and related nucleotides in protein breakdown. The ATP, ADP, GTP, GDP stimulation, together with the carbamoyl protection of OTC, agree well with the molecular plasticity hypothesis model.

Adenosine Triphosphate↗
PubMed1984

[Pheochromocytomas in children].

Three cases of pheochromocytoma in children are presented. Diagnosis was made by selective adrenal arteriography, ultrasound examination and catecholamines urinary levels. The surgical treatment consisted in exeresis of the tumor in all cases. In one case familial incidence was found. The postoperative course has been normal in all cases.

Adrenal Gland Neoplasms↗
PubMed1984

ATP and other purine nucleotides stimulate the inactivation of ornithine transcarbamylase by broken lysosomes.

Ornithine transcarbamylase (OTC) is very stable in rat liver homogenates, or mitochondria. However, pure OTC from rat or beef liver is inactivated by broken lysosomes. ATP and a number of purine nucleotides, particularly epsilon-ATP, stimulate the inactivation of OTC by broken lysosomes. Inactivation of OTC by trypsin and elastase is also stimulated by epsilon-ATP. Carbamoyl phosphate protects OTC against proteolytic attack by elastase or by broken lysosomes. Thus, environmental factors, e.g., ATP and carbamoyl phosphate, appear to influence OTC stability to proteases.

Adenosine Triphosphate↗
PubMed1984

Studies on chromatin organization in a nucleolus without fibrillar centres. Presence of a sub-nucleolar structure in KCo cells of Drosophila.

In embryonic cell-line derivative KCo of Drosophila melanogaster, the nucleolus, like most nucleoli, contains a small proportion of ribosomal DNA (1-2% of the total nucleolar DNA). The ribosomal DNA is virtually the only active gene set in the nucleolus and is found among long stretches of inactive supercoiled heterochromatic segments. We have demonstrated by use of a Feulgen-like ammine-osmium staining procedure that, depending on the state of growth, more or less fibres of decondensed DNA emanating from the intra-nucleolar chromatin (which is in continuity with the nucleolus-associated chromatin) ramify and unravel within the central nucleolar core to be transcribed. The nucleolus expands or contracts with the variation of activity and could belong to a supramolecular matricial structure such as is shown after extraction of the nuclei. After a long period of exposure to high doses of actinomycin D, the central nucleolar core became an homogeneous fibrous structure that could be interpreted as an aggregate of protein skeletal elements. The mechanism of repression and derepression of the nucleolar chromatin could thus be explained by a mechanism involving in part a sub-nucleolar structure. We propose a schematic organization of the nucleolar chromatin in KCo cells of Drosophila and discuss it in relation with other nucleolar organizations.

Animals↗
PubMed1984

Lymphangioma of the duodenum.

A case of lymphangioma of the duodenum is reported, and the literature pertinent to its pathology reviewed. This is the eleventh case reported, and the third in which the diagnosis has been made by endoscopy. The clinical and histological characteristics are important, on account of its presentation and its penetrating character into the neighbouring structures. The characteristics of this tumor seen during endoscopy are discussed.

Duodenal Neoplasms↗
PubMed1984

Treatment of exacerbations of chronic bronchitis. A comparative double-blind study with cotrimoxazole and cefadroxil.

A double-blind, randomized study was carried out in 40 chronic bronchitic patients, to evaluate the effectiveness of cefadroxil as compared with cotrimoxazole in the treatment of the exacerbation stage. The patients were in hospital while the study lasted and received cotrimoxazole at doses of 160 mg of trimethoprim and 800 mg of sulfamethoxazole twice a day, or cefadroxil 500 mg twice a day, for seven days. To evaluate the response the following parameters were used: clinical improvement, reduction in volume of sputum, reduction in purulence of the sputum and eradication of germs from the sputum. All the parameters improved in both groups of patients without any significant difference between the two types of treatment.

Adult↗
PubMed1984

Changes in platelet aggregation caused by glyburide in diabetic patients.

The effect of glyburide on platelet aggregation was investigated in 31 patients with maturity-onset diabetes. Platelet aggregation in platelet-rich plasma was measured before and one hour after the patients had ingested 5 mg of glyburide. The drug caused a significant decrease in platelet aggregation as determined by changes in the amplitude and slope of the curve.

Adult↗