Polysomnographic evaluation of the hypnotic effect of Valeriana edulis standardized extract in patients suffering from insomnia.

Valeriana edulis ssp. procera, commonly known as "valeriana mexicana", is widely used in Mexican traditional medicine for the treatment of insomnia and anxiety. To evaluate the hypnotic effect and safety of 450 mg of Valeriana edulis standardized hydroalcoholic extract in patients with insomnia, a double-blind, cross-over, controlled study was carried out. Valeriana officinalis extract, at the same doses, was used as a positive control. In a sleep laboratory, polysomnographic (PSG) recordings were performed for analyzing the quantity and architecture of sleep as well as evaluating morning sleepiness, memory quotient, and side effects. The experimental procedures were conducted on four consecutive nights of 8 h each. Twenty patients were admitted. Based on the PSG results, V. edulis reduced the number of awaking episodes while both treatments increased the rapid eye movement (REM) sleep; this last parameter was better improved by V. officinalis extract. Other PSG data did not achieve outstanding statistical differences, but the clinical tendency with both treatments was to increase the sleep efficiency index. These Valeriana extracts produced beneficial effects on sleep architecture because they diminished the time of stages 1 and 2 in non-REM sleep while they increased delta sleep. Validated clinical tests showed that both species reduced notoriously the morning sleepiness, that was further improved by V. officinalis extract, and did not affect anterograde memory. In only three cases were slight side effects observed, one due to the experimental extract. Chemical analysis of the hydroalcoholic extract of V. edulis indicated that this extract contains 0.26 % of dihydroisovaltrate as the main valepotriate, and that it does not contain valerenic acid. In general, the results support the hypnotic effect and safety of acute treatment of Valeriana edulis and Valeriana officinalis on patients suffering insomnia.

[Spirometric pulmonary age and its correlation with the chronological age of asthma patients]. / Edad pulmonar por espirometría y su correlación con la edad cronológica de pacientes con asma.

AIMS: Pulmonary age as a linear regression spirometric index, expresses pulmonary ventilatory function. OBJECTIVE: A pilot study was done to assess the differences of the values of the pulmonary age index and chronological age in patients with bronchial asthma and healthy volunteers. MATERIAL AND METHOD: We studies 111 subjects, 31 healthy and 80 with asthma. RESULTS: All of them underwent spirometry. Healthy individuals showed a mean chronological age of 35 years, and a pulmonary age of 26 years. Asthmatic patients showed a mean chronological age of 38 years, and a pulmonary age of 59 years. CONCLUSION: Both the time course and the severity of the disease increased pulmonary age.

[Medical student traits associated with future success as physicians]. / Características del estudiante de medicina asociadas al éxito ulterior como médico.

OBJECTIVE: To identify the individual and family factors present during medical studies which are associated to success as a physician. RESEARCH DESIGN: Prolective case-control study. SETTING: Mexico City metropolitan area. STUDY UNITS: 120 physicians considered to be successful and 245 physicians who according to an established criteria were considered to be non-successful. MAIN MEASUREMENTS: A success-achieving index was constructed on the opinion of 134 physicians from different health-care institutions private and public. The index was composed by criteria such as being a member of prestiged academic associations; having a practice in third level institutions; having done postgraduate studies; being a professor with teaching and research activities; having obtained directive medical positions; and a high income at the moment of the interview. RESULTS: The main factors associated to success were: frequent attendance to cultural activities by the family of the subjects (OR = 5.2, IC 95% = 3.15-8.60, p = 0.00000001); the global score obtained during their medical studies, i.e. higher than 8.5 over 10 (OR = 4.43, IC 95% = 2.64-7.49, p = 0.00000001); and having been awarded recognitions, prizes or scholarships during their medical studies (OR = 4.3, IC 95% = 2.64-7.03, p = 0.00000001). A logistic regression model selected the cultural activities of the family, global score during medical studies and earning of recognitions, prizes and scholarships as independent variables associated to success achievement (p = 0.00001). CONCLUSIONS: Frequent cultural activities by the family and academic behavior were the factors present during medical studies which were associated to ulterior success as a physician.

[Usefulness of residuals in clinical research]. / Utilidad de los residuales en la investigación clínica.

The simple linear regression analysis, multiple linear regression and logistic regression constitute powerful statistical analysis tools widely used in clinical research. These kinds of analyses are based upon mathematical models which at the same time are established on certain basic assumptions. The regression analysis assumptions are basically: a) that the model is really linear, b) that the distribution of data is normal (from a statistical point of view), c) that the variances of the employed data are homogeneous (homocedastics) and that the included data are independent. The regression diagnostic has become popular as a form to evaluate if the assumptions have been accomplished, one of its most important techniques is the residual analysis. A residual can be defined as the value which measures the distance between the regression line and the corresponding value of the variable "y". Among these kinds of residuals used to evaluate the assumptions of regression are: the crude residual, the standardized, of student and the jackknife. The most useful among them is the jackknife residual. The usefulness and limitations of the residuals in the evaluation of the regression analysis assumptions are described, basically referring to the identification and handling of extreme values (outliers).

[Physician-patient relations in the outpatient clinic of primary health care units]. / Relación entre médico y paciente en la consulta externa de unidades de primer nivel de atención médica.

The objective of this study was to determine the degree of concordance between physicians and patients at primary health care units with regard to different aspects of medical consultation. The research design was a descriptive survey. The study units were the primary health care units of the Ministry of Health located in the "Gustavo A. Madero" district. 76 patients were interviewed as well as those physicians who gave consultations. A questionnaire was administered to those patients. It included six questions on the following aspects: physical examination, explanation regarding illness and drug prescription, degree of compliance by patients, duration of consultation and an estimation to know if the physician-patient relationship was satisfactory. For these measurements a analogue-visual scale and a semantic differential scale were used. A great variation was found in the correlation between physician and patient. The major degree of concordance was obtained in the way the relationship was perceived by each other (rs = 0.18); the estimation of compliance (rs = 0.10) and the explanation about illness (rs = 0.08). A tendency to disagreement was perceived in the physical examination (rs = 0.18), the duration of consultation (rs = 0.10) and the explanation about drugs (rs = -0.02). A larger degree of agreement was observed when the physician was less than 40 years old, when he had no specialty and when the patients was also less than 40 years old.