Search PubMed⌕ Search

Biomedical subjects

R Martinez

Publications and source records attributed to R Martinez.

At least 253 records · Page 14Linked to original sources
PubMed1988

Ocular penetration and pharmacokinetics of cefotaxime: an experimental study.

Cefotaxime levels in the cornea and the aqueous humour were assayed after local topical application and subconjunctival injection in healthy and infected corneas. The results in infected corneas were analysed pharmacokinetically. The absorption and elimination of cefotaxime within 2 hours after topical administration are adequately predicted by a two-compartment model in which one compartment represents the cornea and the other the aqueous humour, with the elimination taking place from the latter. The transfer coefficient kc (cornea-aqueous) was estimated as 1.452 h-1 and the return transfer coefficient kca (aqueous-cornea) as 0.287 h-1. After subconjunctival injection the levels measured exhibit bi-exponential kinetics, with the apparent absorption constant Ka = 3.816 h-1.

Administration, Topical↗
PubMed1987

Neuronal pp60c-src contains a six-amino acid insertion relative to its non-neuronal counterpart.

Neuronal cells express a pp60c-src variant that displays an altered electrophoretic mobility and a different V8 peptide pattern relative to pp60c-src expressed in tissues of non-neuronal origin. To determine whether the neuronal form of pp60c-src is encoded by a brain-specific messenger RNA, a mouse brain complementary DNA (cDNA) library was screened with a chicken c-src probe and a 3.8-kilobase c-src cDNA clone was isolated. This clone encodes a 60-kilodalton protein that differs from chicken or human pp60c-src primarily in having six extra amino acids (Arg-Lys-Val-Asp-Val-Arg) within the NH2-terminal 16 kilodaltons of the molecule. S1 nuclease protection analysis confirmed that brain c-src RNA contains an 18-nucleotide insertion at the position of the extra six amino acids. This insertion occurs at a position that corresponds to a splice junction in the chicken and human c-src genes. The isolated c-src cDNA clone encodes a protein that displays an identical V8 peptide pattern to that observed in pp60c-src isolated from tissues of neuronal origin.

Amino Acid Sequence↗
PubMed1987

The Spanish Diagnostic Interview Schedule. Reliability and concordance with clinical diagnoses in Puerto Rico.

A Spanish translation of the Diagnostic Interview Schedule (DIS) was assessed using samples of Puerto Rican patients and community subjects from the San Juan area. Concordance between DIS results from psychiatrists' interviews and from laypersons' interviews was similar to results with the DIS in mainland samples. Comparisons of laypersons' DIS results with psychiatrists' clinical diagnoses yielded generally poorer agreement. Levels of agreement improved when diagnoses were clustered into higher-rank categories. These results raise cultural issues related to the use of the DIS in Puerto Rico.

Adolescent↗
PubMed1987

The prevalence of specific psychiatric disorders in Puerto Rico.

An epidemiologic survey of the lifetime and six-month prevalence rates of several psychiatric disorders was conducted in Puerto Rico. This study, carried out in 1984, applied selected schedules of a Spanish translation of the Diagnostic Interview Schedule to a stratified, island-wide probability sample of the population. With few exceptions, prevalence rates in this study were similar to those obtained in the US communities studied in the Epidemiologic Catchment Area program. The demographic correlates of the disorders are reviewed, and differences between the results of this study and those of previous studies suggesting a higher rate of mental disorder among Puerto Rican populations are discussed.

Adolescent↗
PubMed1987

Pediatric predictive index for hospitalization in acute asthma.

To develop a pediatric predictor index (PPI) for the outcome of emergency management of acute asthma, 156 children were studied prospectively and grouped by outcome. Of 193 episodes, 130 (67.4%) resulted in successful treatment, 39 (20.2%) in relapse, and 24 (12.4%) in admission. Measured and observed variables from before and after initial therapy were analyzed for the three groups. There were no significant differences between the relapse and successful treatment groups, which were combined for analysis and termed the discharge group. Significant differences were noted between the admission and discharge groups only for dyspnea before and after therapy, accessory muscle use, inspiratory breath sounds and wheezing, and post-respiratory rates, but not for pulse or peak expiratory flow rates before or after therapy. The PPI was determined with multivariate logistic regression and is calculated using the following variables: inspiratory breath sounds, wheezing, and respiratory rates. A score of 0 correctly categorized 95% of admissions, but incorrectly categorized 34% of those discharged. Despite low specificity and limited usefulness as early predictors of admission, PPI variables may serve as valuable adjuncts to the physician in determining the outcome of acute asthma in children.

Acute Disease↗
PubMed1987

Torsades de pointes: atypical rhythm, atypical treatment.

For the present, treatment of the acquired Torsades de Pointes consists of removal of the causative agent, correction of the underlying electrolyte imbalance, and initiation of direct therapy. Unresponsive dysrhythmias may need magnesium therapy or cardioversion.

Adult↗
PubMed1987

Obesity and body image: an evaluation of sensory and non-sensory components.

Body image in 38 obese and normal weight subjects was measured using a video TV monitor. Tasks included a continuous task where subjects manipulated the size of their body image on a TV screen, and a discrete task, where they judged the accuracy of their TV image which was presented as either too heavy or too thin. Subjects viewed their images in both regular street clothes and with minimal clothing. Results from the continuous task revealed that obese subjects overestimated body size. All subjects were more accurate on trials in which the initial image was adjusted in the heavier direction. On the discrete task, a signal detection analysis revealed sensory sensitivity differences between obese and normal weight subjects. Obese subjects were better at detecting distortion caused by a too thin image, but were inferior in detecting a too heavy distortion. No significant differences were obtained in response criteria or between clothing conditions.

Adult↗
PubMed1986

Tyrosine phosphorylation in cells treated with transforming growth factor-beta.

Cells stimulated with epidermal growth factor (EGF) or any one of a diverse group of other mitogenic agents display an increased tyrosine phosphorylation of a pair of 42,000 Mr proteins. Transforming Growth Factor-beta (TGF-beta) is able to potentiate the mitogenic effects of Epidermal Growth Factor on some fibroblastic cells (such as the NRK-49F cell line) and, in addition, permits the anchorage-independent growth of these cells. In this study we asked whether these growth-regulatory actions of Transforming Growth Factor-beta are associated with changes in tyrosine phosphorylation of cellular proteins, in particular the 42,000 Mr proteins. We found no effect of Transforming Growth Factor-beta on the extent or time-course of tyrosine phosphorylation, either by itself or in combination with Epidermal Growth Factor. Since the tyrosine phosphorylation of the 42,000 Mr proteins is stimulated both by receptors with tyrosine kinase activity and by diacylglycerol analogs (but not by Transforming Growth Factor-beta), we suggest that the activity of the receptor for Transforming Growth Factor-beta is linked neither to tyrosine phosphorylation nor to phosphatidyl inositol turnover.

Animals↗
PubMed1986

Clinical and CT scan assessment of benign versus fatal spontaneous cerebellar haematomas.

We have studied 15 cases of spontaneous intracerebellar haematomas in 9 males and 6 females. A significant correlation between the clinical presentation and the CT scan features of benign and fatal haemorrhages of the cerebellum is presented. Diagnostic computerized tomographic studies were performed in a mean interval of 31 hours after the initial symptoms. 60% were diagnosed and treated in less than 24 hours; 11 patients had haematomas larger than 3 cm, and 5 (45%) of these cases died with evidence of irreversible brain-stem damage. Twelve (80%) showed compression of the fourth ventricle, 9 (60%) obliteration of the brain-stem cisterns and 8 (53%) ventricular dilatation. 8 cases were treated with surgery; 50% of them showed neurological improvement, including two cases with signs of brain-stem compression. 7 patients who were treated conservatively were followed closely with repeated CT scans, which showed that resolution of the mass effect and isodensity of the haematomas larger than 3 cm (73%), hydrocephalus (45%) and intraventricular haemorrhage (40%). Smaller haematomas without CT scan evidence of obliteration of the brain-stem cisterns or hydrocephalus had a better outcome.

Adult↗
PubMed1986

Osteoid and bone formation in desmoplastic malignant melanoma.

A 77-year-old man presented a recurrent subungual malignant melanoma with desmoplastic features in which heterotopic bone had developed. Histological, histochemical and immunohistochemical findings confirmed the diagnosis of malignant melanoma. Electron microscopic findings suggest that desmoplasia is the result of fibroblastic differentiation of spindle melanoma cells.

Aged↗
PubMed1986

Massive pulmonary embolism: short-term effects of thrombolytic treatment.

This study assessed the short-term effects of thrombolytic treatment in 38 patients with massive pulmonary embolism. Thirty-two were treated with streptokinase and six with urokinase. Intrapulmonary artery instillation of fibrinolytic agents was utilized except in 3 patients. There was a marked hemodynamic and arteriographic improvement (p less than 0.0005) in 33 patients (86.8%). Four patients (10.5%) died because of treatment failure. In these cases the fibrinogen concentration remained above 1 gr/liter during therapy. Bleeding was detected in 22 patients (57.8%) but was most often related to puncture or cut-down sites, and only 2 patients (5.2%) had major bleeding. One patient (2.6%) had cerebral hemorrhage. It is concluded that "classic" thrombolytic treatment is to be chosen in life-threatening pulmonary embolism. However, the difficulties sometimes encountered in producing an intense lytic effect and its low fibrinolytic specificity for the thrombus do not permit the obtainment of better results.

Acute Disease↗
PubMed1986

Traumatic false aneurysms of the middle meningeal artery.

The authors report a rare case of traumatic false aneurysm of the middle meningeal artery associated with a delayed contralateral extradural hematoma. The extradural hematoma was evacuated, and the pseudoaneurysm was removed to avoid delayed rupture. The literature on traumatic aneurysms is reviewed.

Adult↗