Search PubMed⌕ Search

Biomedical subjects

R Santos

Publications and source records attributed to R Santos.

At least 73 records · Page 4Linked to original sources
PubMed1993

Type 1 Gaucher disease: molecular, biochemical, and clinical characterization of patients from northern Portugal.

We report the study of 16 catholic type 1 Gaucher disease patients originating from a well-defined region in the north of Portugal where a relatively high incidence is observed. The patients were screened for mutations: 3060G-->A, 5841A-->G, 5976C-->G, and 6433T-->C, which enabled the identification of 27 of the 32 mutated alleles. Four different genotypes were identified, namely 5841G/6433C (n = 6), 5841G/5841G (n = 5), 5841G/? (n = 4), and 6433C/? (n = 1). All but one of the patients carried at least one 5841G mutated allele, making its frequency 62.5%, which is similar to that described for Ashkenazi Jewish patients. The 5841G homozygotes presented an overall milder clinical profile, whereas no clear genotype/phenotype correlation could be established for heterozygous patients. On the basis of residual glucocerebrosidase activity, no distinction could be made between 5841G homozygotes and 5841G/6433C compound heterozygotes. Patients that had at least one 5841G allele (encoding the Ser 370 mutated enzyme) all presented a cell-type-specific residual glucocerebrosidase activity as well as an increased molecular activity when measured in the presence of the physiological activators.

Adolescent↗
PubMed1993

Triiodothyronine (T3) modifies cholinergic-induced hypothermia and tremor in rats.

Hypothermia and tremor responses of oxotremorine and eserine were studied in rats after several T3 treatment regimens. The T3 antagonized oxotremorine-induced hypothermia and failed to antagonize eserine hypothermic effect, but potentiated oxotremorine- and eserine-induced tremors. Acetylcholinesterase activity was not altered in T3 rats. The hypothetical mechanisms to explain changes of central cholinergic responses caused by T3 are discussed.

Acetylcholinesterase↗
PubMed1993

Transvaginal ultrasonographic characterization of ovarian masses by means of color flow-directed Doppler measurements and a morphologic scoring system.

OBJECTIVE: The aim of the study was to test the hypothesis that a combination of a previously devised morphologic scoring system and color flow-directed Doppler measurements would afford better discrimination between benign and malignant ovarian masses. STUDY DESIGN: The scoring system and color flow-directed Doppler measurements for 115 masses were prospectively analyzed and correlated with histopathologic surgical findings. RESULTS: In 21 masses (18 patients) no flow was obtained. Seventy-eight masses in 70 patients were benign, and 16 masses in 12 patients were malignant. The mean total score for the benign masses was 6.7 and for the malignant masses 11.7. The resistance index was 0.64 for the benign lesions and 0.39 for the malignant masses (range 0.2 to 0.98). The mean pulsatility index of the benign masses was 1.17 and 0.52 for the malignancies (range 0.2 to 2.6). There were no malignancies in the group with no flow obtained. The sensitivity and specificity of score alone was 94% and 87%, respectively, with a 60% positive predictive value. By means of resistance index or pulsatility index the sensitivity was 94%, the specificity 99%, and the positive predictive value 94%. CONCLUSION: These results suggest that Doppler flow measurements alone and in conjunction with a scoring system help differentiate benign from malignant masses.

Adenocarcinoma↗
PubMed1993

Immunoscintigraphy with 99mTc-labelled anti-CEA monoclonal antibody in colorectal carcinoma.

With the introduction of immunoscintigraphy (IS) with 99mTc-labelled anti-CEA monoclonal antibodies (MoAb), a clinical relevant method in nuclear medicine can be expected in the diagnosis and follow up of colorectal cancers. We performed IS (whole body, planar and SPECT) with a 99mTc-labelled intact anti-CEA MoAb (BW 431/26) in 18 patients with primary colorectal carcinoma, metastases or suspicious recurrences from colorectal carcinoma. The results of anti-CEA IS, serum CEA and Ca 19-9 levels were evaluated. Immunoscintigraphy yielded an overall sensitivity of 70.0%, 37.5% for primary tumors, 75.0% for recurrences and 100% for distant metastases. Serum CEA levels were elevated in 10 out of 18 patients (sensitivity 55.5%) and Ca 19-9 were elevated in eight out of 18 patients (sensitivity 44.4%). In the group of patients with metastases, CEA had a sensitivity of 100% and Ca 19-9, of 83.3%. From this prospective study, we can conclude that IS with 99mTC-BW 431/26 is a reliable tool in the post-operative follow-up study of patients with colorectal carcinoma, namely in the detection of distant metastases.

Aged↗
PubMed1992

[Inadequate demand in a pediatric hospital emergency department: factors involved].

BACKGROUND: The massification of pediatric hospital emergency departments (PED) is due to bad use of the same by a large number of users. The causes related with this inadequate use have not been properly evaluated. METHODS: A sample representative of the population demanding medical care in a PED of a regional hospital was studied with the motives and sociodemographic and cultural factors presumably related with this inadequate demand being analyzed. RESULTS: 52% of the cases had had no previous contact with the primary level of health care and 79% had gone to the PED on their own initiative. With regard to consultations, 65.0 +/- 4.8% were catalogued as inadequate and a statistical relation was found with the age of the patient (less than one year), place of residence (urban) and the arrival by initiative of the patients themselves. CONCLUSIONS: Pediatric hospital emergency departments receive a high number of inadequate consultations at the second level of health care. The importance of the age of the patient, accessibility of pediatric hospital emergency departments and who takes the initiative to come must be emphasized as predictive variables of the bad use of these pediatric departments.

Child↗
PubMed1992

Linkage disequilibrium between phenylketonuria and RFLP haplotype 1 at the phenylalanine hydroxylase locus in Portugal.

RFLPs of 36 normal and 41 mutant alleles at the phenylalanine hydroxylase locus were determined in 31 Portuguese kindreds. A total of 14 haplotypes including 10 normal and 7 mutant alleles were observed. Almost 75% of all mutant alleles were confined within only two haplotypes, namely haplotype 9 (17.1%) and haplotype 1 (56.1%). This frequency of mutant haplotype 1 in Portugal is, to our knowledge, the highest for this mutant haplotype in all studies reported to date. Other mutant haplotypes were either rare (haplotype 2, 9.7%) or totally absent (haplotype 3, 0%). Only 24.5% of all mutant alleles were found to consistently carry identified mutations, particularly R261Q (9.8%), R252W (3.3%), R408W (1.6%) and delta I94 (3.3%). A new mutation, L249F, located in the seventh exon of the gene, accounted for 6.5% of all mutant alleles in our series. Interestingly, this mutant genotype was consistently associated with mutant haplotype 1 (P less than 0.01), as also observed for the R261Q mutation. It appears, therefore, that mutant haplotype 1 is genotypically heterogeneous in Portugal and that more than two mutations account for its prevalence in this country.

Alleles↗
PubMed1992

Reliability of the measurement of postprandial thermogenesis in men of three levels of body fatness.

To determine the reliability of the measurement of postprandial thermogenesis by indirect calorimetry and to clarify further the relationship of obesity to thermogenesis in men, the thermic effect of a 720-kcal, mixed liquid meal was compared in 13 lean men (mean +/- SEM, 11.2% +/- 1.4% body fat), 10 average men (22.4% +/- 1.6% body fat), and 12 obese men (33.4% +/- 1.6% body fat) on two occasions. Resting metabolic rate (RMR) was measured for 3 hours: (1) in the fasted state, and (2) after a 720-kcal mixed liquid meal, on two occasions. The thermic effect of the meal, calculated as the postprandial energy expenditure minus the fasting RMR (kcal/3h), was greater for the lean and average men than for the obese men during both trials (P less than .001), but was only marginally different between the lean and average groups (P = .16). The mean values for the two trials were similar and the measurement of thermogenesis was highly reproducible with a reliability coefficient of r = .932 (P less than .001). Across all groups, thermogenesis correlated strongly with percent body fat (r = -.64, P less than .01), but within the average men, thermogenesis was uncorrelated with percent body fat (r = .09) but highly correlated with the glucose response to the meal (r = -.75, P less than .05). Thus, factors other than body fatness, such as insulin sensitivity, may determine thermogenesis within this heterogeneous middle group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1992

[Multidisciplinary experience in the approach to the hypertensive patient].

PURPOSE: To evaluate the impact of the educational activities on the approach of patients with hypertension, with an interdisciplinary team. METHODS: Fifty patients divided into two groups: A) with 25 patients who participated in educational activities in the Hypertension League (HL) and B) who were also registered and did not take part in the activities. They were studied regarding blood pressure (BP), weight control, smoking habits, alcoholic beverage consumption, physical activities and frequency of medical care. RESULTS: There was a drop in BP of 84% of the patients in group A and 88% in group B, a drop in weight in 60% of group A and 44% of group B. We registered the presence of 4% of smokers in group A and 16% in group B. Physical activities were regular in 56% of group A and 36% in group B. Absenteeism to meetings was slightly higher among group B (44%) when compared with group A (30%). CONCLUSION: In spite of not having observed any significant differences between both approaches, regarding to strict BP control, we were able to observe a noticeable advantage in favor of the educational approach to the group, with participation of interdisciplinary team.

Blood Pressure↗
PubMed1991

Birthweight, early passive respiratory system mechanics, and ventilator requirements as predictors of outcome in premature infants with respiratory failure.

Early respiratory mechanics have been reported to predict outcome in newborns with respiratory failure. However, it remains unknown whether measurements of pulmonary function add significantly to the predictive value of more readily available variables The present study was designed to answer this question. Passive respiratory system mechanics were measured by an airway occlusion technique in 104 ventilator-dependent premature infants between 6 and 48 hours of life and corrected for infant size. A ventilation index [FiO2 x mean airway pressure (MAP)] was calculated at the time of pulmonary function testing. Poor outcome was defined as death from respiratory failure or need for supplemental oxygen at 28 days. Stepwise logistic function regression examined whether ventilation index and respiratory mechanics added predictive power over and above birthweight. Five infants died, and 45 patients required supplemental oxygen at 28 days. Birthweight was a strong predictor and would have entered the logistic model first in any case. Ventilation index added significantly to the predictive model (P = 0.038). Respiratory system conductance (P = 0.15) and compliance (P = 0.93) entered on the third and last step, respectively. We conclude that in premature infants with respiratory failure, birthweight is a strong predictor of outcome. Early ventilator requirements but not respiratory system mechanics, add significantly to this predictive model.

Birth Weight↗
PubMed1990

Respiratory response and pharmacokinetics of intravenous salbutamol in infants with bronchopulmonary dysplasia.

The effects of iv salbutamol on respiratory mechanics were studied in six infants with bronchopulmonary dysplasia. Salbutamol was infused at a dose of 30 micrograms/kg over 30 min in five infants; a sixth infant received 66.7 micrograms/kg over 4 min. Salbutamol caused improvement in total respiratory system compliance and in airflow resistance. There was no correlation between salbutamol serum concentration and pulmonary function. Elimination half-time appears to be dictated in these infants more by the distribution volume (Vd) than by clearance (Cl). The area under concentration-time curve of salbutamol correlated inversely to the change in heart rate (HR). There was a significant positive correlation between Vd and percent HR change. These data provide evidence that preterm infants have measurable activity of bronchiolar beta 2 receptor responsive to salbutamol.

Airway Resistance↗
PubMed1988

Central responses to cholinergic drugs of REM sleep deprived rats.

The present work studied the effects of REM sleep deprivation on the responses to cholinomimetic drugs in rats. Cataleptic behavior induced by pilocarpine, oxotremorine and eserine was not modified by previous REM sleep deprivation. On the other hand, the intensity of oxotremorine- and eserine-induced tremors, but not that of pilocarpine, was clearly augmented in the REMd rats and latency to the first tremor was shorter. REM sleep deprivation also potentiated the convulsions induced by nicotine. Two hypothetical mechanisms through which REM sleep deprivation could lead to the described hyperresponsiveness to cholinomimetic drugs are discussed.

Animals↗
PubMed1988

Red lacrimal secretion (chromodacryorrhea) induced by cholinergic drugs in rats subjected to the watertank technique.

Red tears (chromodacryorrhea) in rats are due to porphyrin pigments secreted by Harder's glands and are believed to involve muscarinic mechanisms. Chromodacryorrhea was observed in rats treated with pilocarpine, oxotremorine and neostigmine and this response was blocked by anticholinergic drugs. However, in rats deprived of rapid eye movement (REM) sleep (REMd) for 3 days, through the watertank technique, chromodacryorrhea did not develop even when cholinergic agonists were given in doses severalfold higher than those active in non-REMd animals. Decrease of chromodacryorrhea also was obtained in rats previously treated with neostigmine; conversely, previous treatment with atropine induced an increased chromodacryorrhea when the rats were further challenged with pilocarpine and oxotremorine. It is proposed that the absence of red tears in REMd rats might be due to a down regulation of peripheral cholinergic receptors.

Animals↗
PubMed1983

Serotonin receptor activation in rats previously deprived of REM sleep.

The effects of serotonin precursors (L-5-hydroxytryptophan and L-tryptophan, with or without MAO inhibitors) and of agonists (quipazine and 5-methoxy-N,N-dimethyltryptamine-MeO-DMT) were studied in 3 day REM-deprived or control rats, by recording the presence of the serotonin syndrome and the number of head shakes. The REM sleep-deprived rats showed a larger incidence of the serotonin syndrome and a greater number of head shakes in comparison to the control animals, when challenged with the serotonin precursors. Conversely, REM sleep deprivation did not modify the responsiveness of rats to 0.75-6.0 mg/kg of MeO-DMT and to 2.4-6.0 mg/kg of quipazine. However, REM-deprived rats reacted less than controls to 0.3-1.25 mg/kg of quipazine. Increased turnover due to REM sleep deprivation could explain the augmented responsiveness of the rats to the serotonin precursors. Conversely, the decreased responsiveness to quipazine could result from receptor hyposensitivity due to intense receptor activation, caused by the increased turnover, during the 3 day period of REM sleep deprivation.

5-Hydroxytryptophan↗