Simultaneous treatment of Escherichia coli cultures with methyl-nitrosoguanidine and mitomycin C induces recA-dependent inhibition of respiration but not inhibition of cell division. This pattern of SOS functions expression is the same as that is found following treatment with methyl-nitrosoguanidine alone and contrary to the pattern induced after mitomycin C addition. The same result is obtained when a culture of E. coli RecA441 (formerly tif) is shifted to 42 degrees C and treated simultaneously with methyl-nitrosoguanidine. The suppressor effect of this compound over the pattern of SOS functions expression induced by mitomycin C or high temperature in recA441 mutants is directly related to the increase in its dose. Moreover, the division temperature-sensitive mutant ftsA treated with methyl-nitrosoguanidine and high temperature does not show any decrease in its normal filamentous growth when cultured at 42 degrees C. This indicates that the effect of methyl-nitrosoguanidine on the recA-independent inhibition of cell division is not due to any indiscriminate effect of this compound over the division process. These results suggest that the specific kind of lesion caused in DNA is very important in determining which SOS function is induced.

Antibiotics, Antineoplastic↗

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

Antibodies to commercially available interferon-beta molecules in multiple sclerosis patients treated with natural interferon-beta.

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Antibodies↗

PubMedDate not supplied

[Epidemiologic surveillance for the prevention and control urban violence].

Violence prevention policies should be based on information, follow-up, research, and analysis, all of which increase the chances of success and make it easier to evaluate interventions. This implies, in turn, that there is a need to create surveillance, research, and prevention models for violence within the sphere of public health and epidemiology, a task that constitutes an integral part of the Pan American Health Organization's Regional Plan of Action Health and Violence. This article describes the objectives of epidemiologic surveillance systems and explains their purpose and scope, along with the barriers that stand in the way of their implementation. It also examines a number of variables and their definitions, the types of analyses and reports that should be generated, and the decisions that can be made on the basis of these reports. Finally, it discusses ethical criteria and describes the experiences of the program known as Desarrollo, Seguridad y Paz (DESEPAZ) in Cali and Santa Fe de Bogota, Colombia, where an epidemiologic surveillance system against violence has been implemented.

Analysis of Variance↗

PubMedDate not supplied

[Acute myocardial infarct in persons over 70. The results and differential characteristics].

Distinctive features of patients over 70 years with acute myocardial infarction (AMI) are studied. Between May 1988 and April 1989, 420 patients with AMI were admitted to our hospital; 118 of them (28.5%) were older than 70 years. In this group of patients, proportion of woman was higher (36 vs 16%, p less than 0.001), while incidence of smoking and hypercholesterolemia was lower (41 vs 64%, p less than 0.001; and 15 vs 29%, p less than 0.05). There was no differences in other risk factors, prior history of coronary heart disease (angina, AMI, coronary surgery), or general features of AMI (location, proportion of painless AMI, non-Q-wave AMI, evolved AMI, initial admission to coronary care unit or general ward, time from the beginning of symptoms to admission, residual ejection fraction). The incidence of severe complications was superior between older patients: shock, 17 vs 7% (p less than 0.05); Killip class III/IV, 30 vs 13% (p less than 0.001); and fascicular blocks: 26 vs 16% (p less than 0.05). Hospital mortality was also higher in older patients, 25.5 vs 14% (p less than 0.01). No patients older than 70 years received fibrinolytic therapy, and only one underwent coronary artery surgery (22% and 15%, respectively, in younger patients). Coronary arteriography, exercise test, radionuclide ventriculography and Holter monitoring were also performed before discharge in a lesser proportion in older patients. We conclude that mortality and severe complications were higher between patients over 70 years with AMI. We think that mortality could be decreased by a more aggressive management in, at least, selected groups of older patients with AMI.

Aged↗

PubMedDate not supplied

[Various considerations on the lesions and treatment of Trichophyton verrucosum in calves. Preliminary report].

This paper is devoted to study the magnitude of the skin lesions produced by Trichophyton verrucosum--previously identified--as well as the therapeutic measures taken. For this study were used 45 calves with a skin fungal process identified, by the adequate culture means, as from T. verrucosum. Through the histic study of the skin biopsy were found several lesions due to tinea corporis dermatitis. The use of the drug employed is described. The cure rate obtained with this drug was the following: an 80% cure within 6 days, a 12,5% within 8 days, and a 7,5% within 10 days; no cure was observed in the controls--5 from the total number.

Animals↗