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Biomedical subjects

J L Santos

Publications and source records attributed to J L Santos.

At least 19 recordsLinked to original sources
PubMed1991

[The Zippin's procedure for the estimation of animal populations].

Zippin's procedure is one of the most accurate methods used to estimate total populations from removal trapping data. However, explicit algebraic solutions of the maximum likelihood equations do not exist. Hitherto they have been obtained from graphs known as Zippin charts. In this paper a Newton-Raphson procedure is used to obtain numerical solutions to the equations. Comparisons with the classical method show some differences in the parameters, particularly in the estimation of the standard error.

Animals↗
PubMed1991

Evaluation of lymphocyte activation by flow cytometric determination of interleukin-2 (CD25) receptor.

Lymphocyte response to mitogens is a habitually-used test in the evaluation of the immune system. The usual method with [3H]thymidine yields results which are difficult to interpret. In our search for an alternative, we examined the feasibility of determining T lymphocyte activation by measuring interleukin-2 receptor (CD25) expression with flow cytometry. We found a good correlation between CD25 molecule expression and the dose of phytohemagglutinin, however, there was no correlation between disintegrations per minute produced by [3H]thymidine uptake and the percentage of CD25 expressed by cells.

Adult↗
PubMed1990

[Evaluation of larval development of Anopheles darlingi (Diptera-Culicidae) raised in the laboratory on different diets].

Three diets for A. darlingi larvae were tested in order to arrive at the following parameters indicative of development in this phase: length of time, both for overall as for each stage of evolution and daily and total stage-survival. A methodology which combined two vital statistical methods of analysis, adjusted to the study of populations under laboratory conditions, was used for determining these parameters. The length of time for overall and for each stage of, evolution were graphically assessed on the basis of trend curves of colony median stages, in sequential surveys. Values for the total and the daily stage-survival were stimulated from survival tables. Results permitted the selection of the most adequate diet for the larval development as that composed of one part of fish flour to two parts of bread flour and two parts of a heat germ, giving an average length of 12.9 days between the first larval stage and the emergent adult. Total survival rate was of 95%.

Animals↗
PubMed1990

[Frequency in human environment and dispersion of Culicidae mosquitoes in an area adjacent to a primitive Atlantic plain forest].

Results of peridomiciliary and forest environment mosquito catches are presented. By using the method single host, mosquitoes were identified according to blood-meal and thus their dispersal was observed. Evidence was obtained for movements of Aedes scapularis, due apparently were appetential flights, as well as its permanence in peridomiciliar resting places. Occurrence in domestic animal shelters was recorded for this species. Peridomiciliar human bait catches showed regular occurrence of Ae. scapularis, Anopheles bellator, An. cruzii and Culex sacchettae, but anophelines abandoned the human environment for the surrounding forest. Feeding index showed clearly a preference on the part of Ae. scapularis for bovine hosts. The peridomiciliar frequency of Cx. sacchettae suggests a domiciliary tendency. The influence of large domestic animals in the human environment surrounded by primitive Atlantic plain forests, on the domiciliation of the sylvatic mosquitoes, is emphasized.

Aedes↗
PubMed1989

Clinical response and plasma haloperidol levels in chronic and subchronic schizophrenia.

Levels of haloperidol were determined by radioimmunoassay (RIA) in 30 schizophrenic patients (diagnosed according to the criteria of DSM-III), who were treated with fixed doses of this neuroleptic for a period of 21 days. An inverted U-shaped relationship was found between the percent improvement observed in the BPRS global score and the steady state of haloperidol. The interval of effective concentration of haloperidol was set between 12.0 and 35.5 ng/ml. However, the limits of such an interval found in the subchronic schizophrenic subgroup (SS) ranged from 7.4 to 24.9 ng/ml, whereas in the chronic schizophrenic subgroup (CS), it ranged from 14.8 to 38.5 ng/ml. This finding suggests that the interval of effective concentrations may vary as a function of the number of years of evolution of the subjects' illness. This may be compatible with the development of tolerance in the mesolimbic and/or mesocortical dopaminergic systems as a response to prolonged neuroleptic treatments.

Adolescent↗
PubMed1989

Determination of plasma haloperidol concentrations by radioreceptor assay in schizophrenia: clinical utility.

1. Haloperidol concentrations were determined by radioreceptor assay (RRA) and prolactin concentrations were measured in 20 patients diagnosed as schizophrenia (DSM-III). 2. The patients were treated with a fixed dose of haloperidol for 21 days. 3. Our results suggest the existence of a curvilinear relationship, in the form of an inverted U, between stable haloperidol levels and clinical improvement assessed by total BPRS score. 4. We also found a curvilinear relationship between the improvement observed in positive symptoms and state steady levels. 5. No relationship was seen between improvement in negative symptoms and state steady levels. 6. An interval of optimal haloperidol concentration was found: 8.1 ng/ml to 19.6 ng/ml. 7. No relation was found between the dose of haloperidol administered and plasmatic concentration, nor between haloperidol and prolactin levels. 8. Our findings suggest that haloperidol concentrations determined by RRA have clinical utility as predictors of response in schizophrenia.

Adolescent↗
PubMed1989

Cytological basis of the B chromosome accumulation mechanism in the grasshopper Heteracris littoralis (Ramb).

An accumulation mechanism of the standard B chromosome of the grasshopper Heteracris littoralis has been studied in a natural population located in El Saler (Valencia) by two different methods: (i) the karyological analysis of the offspring from wild females and (ii) cytological observations of male and female meiosis. The transmission rate of the accessory through females obtained from crosses (0.61) was slightly lower than that obtained from direct meiotic observations of secondary oocytes (0.71). The B chromosome is transmitted at a rate of about 0.5 through 1B males, the value expected from mendelian segregation. The implications of these findings are discussed and the parasitic nature of the B is proposed.

Animals↗
PubMed1989

A quantitative study of chiasma terminalization in the grasshopper Chorthippus jucundus.

The possible existence of chiasma terminalization in the grasshopper Chorthippus jucundus was tested in four males by means of comparisons between chiasma locations at diplotene and metaphase I within L3, M4 and M5 bivalents. Diplotene cells were stained by a C-banding technique to recognize heterochromatic regions, especially the centromeric ones, whereas metaphase I cells were stained by a silver staining technique that visualizes a core-like structure that extends through each homologous chromosome. The core is very pronounced at kinetochores and forms cross-shaped configurations at chiasmata. No evidence of chiasma terminalization has been found.

Animals↗
PubMed1989

Is early diagnosis of hypertension a function of cuff width?

This study followed blood pressure in 11 subjects 5 years after slight or established hypertension had been revealed using a cuff of the correct width (appropriate to arm circumference); at that time, the use of a standard-width cuff (12 cm) had shown a blood pressure within the normal range. For the present study, blood pressure was determined indirectly under very strict conditions so that a faithful comparison between the readings with both cuffs could be achieved. An important underestimate of blood pressure was detected in thin arms when the standard width cuff was used. The present measurements showed a consistent increase in blood pressure with standard-width cuff readings, confirming the hypertension that had been identified using the correct cuff width 5 years previously. These results support our previous hypothesis that early diagnosis of hypertension can be masked by the standard-width cuff, particularly in lean persons.

Adolescent↗
PubMed1989

Clinical implications of determination of plasma haloperidol levels.

The aim of this study was to analyze the clinical utility of monitoring plasma levels, since the utility of monitoring is not yet well established. After a washout period, 30 schizophrenic patients were given fixed doses of haloperidol for 3 weeks. A U-shaped second-grade polynomic relationship (R = 0.69) was found between steady state of haloperidol and percentage improvement in total score on the Brief Psychiatric Rating Scale. The interval of effective concentrations was between 12 and 59 ng/ml. Fourteen of the 15 patients who had a steady state of haloperidol within that therapeutic interval were responders: only 5 out of the 15 patients below the therapeutic interval were responders. None of the 5 patients who had concentrations below 8 ng/ml was a responder. Furthermore, responder patients showed a steady-state level of haloperidol significantly higher than that of nonresponders. These data suggest that plasma levels of haloperidol are predictors of therapeutic response in schizophrenic disorders.

Adult↗
PubMed1989

[Analysis of the attitude of the hospital staff regarding the hepatitis B vaccine].

The attitude of the staff of the University Hospital Virgen de la Macarena in Sevilla was evaluated to assess their degree of information about hepatitis B vaccine, their attitude towards vaccination and the possible causes of the latter. To this end, a survey was carried out among 200 individuals from the hospital staff, distributed in four professional level categories (doctors, nurses, clinical assistants and attendants). The level of knowledge of the disease, the participation in the vaccination and the future attitude were evaluated. Group differences were also analysed. The results showed a low information level about the vaccine (81.5% were not adequately informed), a low vaccination index (13.5%) and a low intention to be vaccinated in the future (34.6%), mostly due to poor information.

Attitude of Health Personnel↗
PubMed1988

Somatomedin-C and growth hormone levels in anorexia nervosa in relation to the puberal or post puberal stages.

1. Plasma concentrations of somatomedin-C and GH were determined in 21 patients diagnosed as anorexia nervosa (AN) and in 44 controls. 2. Somatomedin-C concentrations were significantly lower in pubertal AN patients than in controls, but not in post pubertal patients. 3. GH was increased in both pubertal and post pubertal AN patients, although more in pubertal AN patients. 4. Our results suggest that the hormonal alterations that appear in AN constitute a mechanism of defense against starvation. The activation of these defense mechanisms and the degree of modification produced in normal hormonal patterns depend not only on caloric intake but also on metabolic requirements.

Adolescent↗
PubMed1988

Pulse pressure as a function of cuff width.

Pulse pressure was investigated by indirect sphygmomanometry using two different cuff widths, standard (12 cm) versus correct (20% wider than arm diameter). Following the American Heart Association's recommendation for arterial pressure measurements, 7 cuffs of various widths (8 to 14 cm) were used as correct cuffs on 900 subjects; in only 50 was the standard cuff appropriate. Pulse pressure as a function of cuff width was significantly lower (P less than 0.001) with the standard cuff on subjects with diastolic pressure less than 90 mmHg (36.4 +/- 0.3 mmHg vs 41.8 +/- 0.3 mmHg) and above 90 mmHg (39.6 +/- 1.2 mmHg vs 43.8 +/- 1.3 mmHg). Mean systolic and diastolic arterial pressures were underestimated by 12.7 mmHg and 7.7 mmHg, respectively. These results suggest that cuff width influences data obtained by indirect sphygmomanometry, producing over- or underestimates when the ratio of arm circumference to cuff width differs from 0.38.

Adolescent↗