Search PubMed⌕ Search

Biomedical subjects

J Ortiz

Publications and source records attributed to J Ortiz.

At least 109 records · Page 6Linked to original sources
PubMed1989

A multicenter, randomized, double-blind study comparing once-daily bedtime administration of famotidine and ranitidine in the short-term treatment of active duodenal ulcer.

The efficacy and safety of famotidine and ranitidine in the treatment of active duodenal ulcer were compared in a multicenter, randomized double-blind study. The study was carried out at 5 centers and involved a total of 143 patients with endoscopically documented active duodenal ulcer. The patients received either famotidine (1 40 mg tablet at night) or ranitidine 2 150 mg tablets at night). Endoscopic examinations were performed at 4 and 6 weeks of active treatment. Day and nocturnal pain were also monitored, and the laboratory and clinical profiles evaluated. One hundred and thirty-three patients fulfilled the evaluation criteria (66 patients in the famotidine group and 67 in the ranitidine group). Healing rates at weeks 4 or 6 of treatment showed no significant differences between the famotidine group and the ranitidine group. The healing rates were 78% at week 4 and 96% at week 6 in the famotidine group, and 76% at week 4 and 95% at week 6 in the ranitidine group. Similar results were observed in both treatment groups with regard to pain resolution, decrease in antacid intake and safety profile.

Adult↗
PubMed1988

Serotonergic status in human blood.

Preliminary data on the existence of a plasma pool of serotonin (5HT) in human blood has been confirmed in a descriptive study of two distinctive pools of 5HT (plasma and platelet), and its metabolite 5-hydroxyindoleacetic acid (5HIAA), in the blood of 175 healthy individuals. Plasma 5HT (0.93 +/- 0.67 ng/mL, X +/- S.D.) shows a significant but low correlation with platelet 5HT (711 +/- 319 ng/10(9) platelets) (r=0.29, p less than 0.001). Diastolic blood pressure correlated significantly with plasma 5HT (r=0.51, p less than 0.05) and whole blood 5HT (r=0.52, p less than 0.05) in older individuals (50-65 years) but not in the whole group (r=0.052, n.s.). Differences between sexes include plasma 5HT, whole blood 5HT (both higher in women) and plasma 5HIAA (lower in women) and may reflect a differential whole body 5HT function. The effect of meal consumption and a peripheral 5HT synthesis inhibitor (carbidopa) in four human subjects has also been tested. Carbidopa (0.7 mg/kg) significantly lowers the plasma pool of 5HT (mean change -33%) 2 hr. after administration, while platelet 5HT is unchanged. These data support the existence of a human plasma 5HT pool, with a rapid turnover, different from the 5HT in platelets (slow turnover, reserve pool). Both may be useful in evaluating different aspects of 5HT-mediated pathologies.

Adult↗
PubMed1988

Biogenic amines stimulate regeneration of cilia in Tetrahymena thermophila.

Serotonin and catecholamines affect the regeneration of cilia in Tetrahymena thermophila in a dose-dependent manner: micromolar concentrations are stimulatory, whereas millimolar concentrations have little or no effect. This conclusion is based on motility measurements in regenerating cells and on ciliary counts in scanning electron micrographs. In addition, the recognition mechanism for each hormone appears to be specific and independent. Our results suggest an evolutionary link with hormonal mechanisms in multicellular eukaryotes.

Animals↗
PubMed1987

Coagulation defects during extracorporeal circulation in the dog.

This study was undertaken in an attempt to diminish the frequency and severity of postextracorporeal circulation hemorrhage in dogs. Its purpose is to ascertain the amount of 99mTc-labeled autologous fibrinogen deposited in the oxygenator, as well as the coagulation defect originated during the surgical procedure when heparin is not administered (group I) and when it is at doses of 1 mg/kg body weight (group II) and 3 mg/kg body weight (group III). The result demonstrate that the fibrinogen deposition in the oxygenator decreased as the dose of heparin administered was augmented. The coagulation disorders were produced by factor consumption, affecting all dogs in group I. The same type of alteration was produced with the use of heparin, but in some the platelet count, fibrinogen and fibrinogen degradation products and the prothrombin and thrombin times were maintained within normality or were only slightly altered. Significant differences were not detected between groups II and III. For this reason, we recommend the utilization of heparin in experimental extracorporeal circulation in a single dose of 1 mg/kg body weight, administered at the initiation of bypass, which provides a sufficient level of anticoagulation for at least 60 min and makes its neutralization with protamine unnecessary, the effects of which are especially adverse in the dog.

Animals↗
PubMed1986

Left ventricular function after a single large dose of verapamil.

The effects of a single large dose of verapamil on left ventricular (LV) function were evaluated noninvasively in 18 chronically hypertensive patients. Each patient was given a single oral dose of verapamil, 240 mg, before and after which arterial blood pressure was measured and an echocardiogram and a phonomechanocardiogram were obtained. Reactional symmetrical myocardial hypertrophy was seen in all patients on the first echocardiogram. Results showed that heart rate was not significantly altered, but there were significant decreases (p less than 0.01) in systolic blood pressure (183.89 to 127.56 mm Hg) and diastolic blood pressure (101.11 to 77.67 mm Hg). The following parameters were also significantly decreased (p less than 0.01): LV ejection time (294.56 to 274.22 ms), LV diastolic diameter (45.78 to 43.99 mm), percentage change in LV diameter (33 to 27.83%), mean velocity of circumferential fiber shortening (1.12 to 1.02 cir/s), posterior wall contraction velocity (40.83 to 36.28 mm/s), LV end-diastolic volume (97.78 to 86.89 cm3), ejection fraction (0.70 to 0.62), stroke volume (70 to 55 cm3) and cardiac output (4.7 to 4 liters/m). Three parameters were significantly increased (p less than 0.01): preejection period (104.06 to 112.06 ms), preejection period: LV ejection time ratio (0.35 to 0.41) and end-systolic volume (29.28 to 32.33 cm3). It is concluded that a single oral dose of verapamil, 240 mg, is highly efficient in lowering arterial blood pressure in chronically hypertensive patients and in reducing the peripheral resistance and LV performance indexes.

Administration, Oral↗
PubMed1986

Localization and comparative nucleotide sequence analysis of the transforming domain in herpes simplex virus DNA containing repetitive genetic elements.

The 7.5-kilobase BamHI E fragment (BamHI-E) of herpes simplex virus type 2 (HSV-2) DNA (map position 0.533-0.583) encodes the 144-kDa subunit of ribonucleotide reductase and induces the neoplastic transformation of immortalized cell lines. To define the minimal transforming region of BamHI-E, a series of subclones were constructed that spanned the entire fragment. These subclones were assayed for focus formation in Rat-2 cells. Removal of the promoter region from the viral 144-kDa-protein gene left the transforming activity of DNA clones intact. A 481-bp Pst I-Sal I subclone of BamHI-E was capable of inducing focus formation and tumorigenic conversion. The nucleotide sequence of this fragment and the colinear nontransforming region of HSV-1 DNA was determined and compared. Striking differences were detected in the structure and organization of repeated sequence elements. Specifically, transforming HSV-2 DNA contains multiple regions of alternating purines and pyrimidines, G + C-rich sequences that are potential binding sites for transcription factor Sp1, and insertion-like sequence elements that are interrupted by base substitutions in nontransforming HSV-1 DNA. These results define a distinct transforming domain in HSV-2 DNA composed of repetitive elements implicated in gene rearrangement and activation.

Base Sequence↗
PubMed1986

DNA amplification and neoplastic transformation mediated by a herpes simplex DNA fragment containing cell-related sequences.

The transforming potential of the herpes simplex virus type 2 (HSV-2) BamHI fragment E (map position 0.533-0.583) encoding the 140-kDa ribonucleotide reductase was assayed by transfection in established Rat-2 cells. Foci of refractile, morphologically distinguishable cells were induced at lower efficiency and after a longer incubation period as compared to the human tumor oncogene EJ-Ha-ras. Focus-derived BamHI fragment E-transformed cell lines formed medium-to-large (0.1-0.25 mm) colonies in soft agar and were tumorigenic in immunocompetent syngeneic rats. Southern blot analysis of normal rat DNA after EcoRI digestion revealed specific DNA segments homologous to HSV-2 BamHI fragment-E DNA. In BamHI fragment E-transformed and tumor-derived lines, about 8- to 30-fold amplification was detected in a subset of the specific HSV-related DNA segments. In addition, extrachromosomal DNA was isolated from transformed cells by plasmid rescue and contained the left-hand 70% of HSV-2 Bam HI fragment E fused to rat DNA. These results indicate the presence in normal cells of nonrepetitive DNA segments, related to the transforming HSV-2 fragment, that can be targeted for genetic alterations associated with neoplastic transformation.

Animals↗