Search PubMed⌕ Search

Biomedical subjects

M Quintana

Publications and source records attributed to M Quintana.

64 records · Page 4Linked to original sources
PubMedDate not supplied

[Imputation of the date of HIV seroconversion in cohorts of haemophiliacs].

OBJECTIVES: To describe the methods used to impute HIV seroconversion date in the haemophiliac cohorts from GEMES project and to validate its use. METHOD: 632 haemophiliacs coming from three hemophilia units identified as HIV+ and 1.092 individuals coming from 5 project GEMES cohorts with a seroconversion window (time among test HIV and HIV+) less than 3 years where mid point (PM) was assumed as seroconversion date. For both groups, seroconversion date was imputed after estimating the probability distribution of seroconversion by means of the EM algorithm. Two imputation methods are used: one obtained from the expected value and the other from the geometric mean of 5 random samples. from the estimated distribution. Imputations have been validated in the non haemophiliacs cohorts comparing with the PM seroconversion date. Also AIDS free time and survival from the different seroconversion imputed dates were compared. RESULTS: Median seroconversion date is located in May of 1993 for the non haemophiliacs and in 1982 for the haemophiliacs. Not big differences are observed among the imputed seroconversion dates and the mid-point seroconversion date in the non-haemophiliac cohorts. Similar results are found for the haemophiliac cohorts. Also no differences are observed in the estimated AIDS-free time for both groups of cohorts. CONCLUSIONS: Geometric mean imputation from several random samples provides a good estimate of the HIV seroconversion date that can be used to estimate AIDS-free time and survival in haemophiliac cohorts where seroconversion date is ignored.

Cohort Studies↗
PubMedDate not supplied

[Clinical factors predicting the appearance of vascular events following a transient ischemic attack].

INTRODUCTION: Patients who have suffered a transient ischemic attack (TIA) have a high risk of undergoing a severe vascular event. Most of them do not receive early attention and cannot benefit from an adequate diagnosis and treatment. AIMS: The aim of this study is to identify the clinical factors that predict the appearance of a new vascular event in these patients. PATIENTS AND METHODS: We conducted a prospective study of 104 TIA patients, who had been given attention during the first 24 hours after the onset of symptoms, for a mean follow up time of 12.6 months. RESULTS: The incidence rates of strokes, ischemic heart disease, peripheral arteriopathy and death were 13, 6, 3 and 8%, respectively. Multivariate analysis identified the following aspects as independent predictors of new strokes: an age above 73 odds ratio (OR) 4.46 (CI 95%, 1.15 17.38) and an atherothrombotic aetiology OR 4.36 (CI 95%, 1.4413.18); and episodes of ischemic heart disease, a history of suffering from such heart disease OR 30.65 (CI 95%, 2.94319.17) and taking oral antidiabetic drugs OR 31.23 (CI 95%, 2.65368.74). Leukocytosis OR 11.21 (CI 95%, 1.25100.39) is linked to the deaths caused by vascular disorders, whereas an atherothrombotic aetiology OR 3.83 (CI 95%, 1.31 11.20) and being male OR 3.44 (CI 95%, 1.02 11.60) were seen to be predictors of the appearance of any vascular event. CONCLUSIONS: Our findings showed that the risk of suffering severe vascular events after a TIA becomes higher. There are a number of useful clinical variables (age above 73, atherothrombotic aetiology, being male, taking oral antidiabetic drugs and leukocytosis) for identifying the patients at the highest risk.

Age Factors↗
PubMedDate not supplied

[The effectiveness of surgical compared to nonsurgical treatment of periodontal disease. 1. Molar surfaces. 24-month study].

The response to the treatment and periodontal maintenance during a period of 24 month, was investigated in 17 patients with periodontal disease by comparing root debridement alone versus root debridement plus surgery, in the molar flat surfaces sites. A total of 443 sites were controlled every 3 month and recorded every 6 month in regard to plaque indice bleeding frequency, probing pocket depth and changes of probing attachment level. The results analysed using linear regression, demonstrated that in sites with initial probing depth 0-3 mm or 4-6 mm. at 24 th months there was an evident improvement in the clinical conditions of the periodontal tissues, independent in the treatment modality. Sites with initial probing depth of 7 or more mm., however, showed a different result. In this sites, the plaque indice and the probing pocket depth were considerable reduced, but the frequency of bleeding and the clinical attachment level showed a negative result, in those sites treated by root debridement alone compared with root debridement plus surgery.

Adult↗