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Biomedical subjects

L F Siqueira

Publications and source records attributed to L F Siqueira.

13 recordsLinked to original sources
PubMed1998

Validation of national algorithms for the diagnosis of sexually transmitted diseases in Brazil: results from a multicentre study.

OBJECTIVE: To validate STD flow charts for the management of genital discharge and genital ulcer currently recommended by the National STD Control Programme in Brazil. METHODS: A study was conducted in five Brazilian STD clinics from January to June 1995. After an interview, a clinical examination was performed by a physician, who recorded a presumptive diagnosis, based on his/her clinical experience. This diagnosis was compared with a gold standard laboratory diagnosis in order to calculate sensitivity, specificity, and positive predictive value of the clinical diagnosis. The validity of the simulated national flow charts was assessed using the same method. RESULTS: A total of 607 men and 348 women participated in the study. Gonorrhoea was the aetiology most frequently detected in men with urethral discharge. The sensitivity of the clinical diagnosis was far lower than the sensitivity fo the national flow chart, using the syndromic approach, for both gonococcal and chlamydial urethritis. Adding a simple laboratory test (Gram stain) to the national flow chart increased the specificity and positive predictive value for gonorrhoea. Among the women with vaginal discharge, a cervical infection was detected in 17%, a vaginal infection in 74%, and mixed infection in 9%. The sensitivity of the diagnosis for cervical infection increased from 16% (clinical aetiological approach) to 54% (when adding a syndromic approach) and to 68% when adding a risk assessment, as in the national flow charts. The cure or improved rate of genital ulcers was 96% after 1 week. CONCLUSIONS: The results of the study will help to convince policy makers and those involved in training healthcare workers in Brazil of the public health advantages of the syndromic approach, as an essential part of STD/HIV control activities.

Adult↗
PubMed1987

[Stable solution of fuchsin--a new method for preparation of Ziehl-Neelsen staining].

The fuchsin salts currently available in Latin American market have shown some instability when in solution, according to the classic Ziehl-Neelsen method, resulting in a total precipitation of the salt. The authors indicate a new technique for the preparation of this solution, in order to minimize the action of interfering factors responsible for the precipitation, obtaining thus a greater solubility of the salt, as well as the solution stability. The method effectiveness is reinforced by the utilization of a smaller amount of the salt and the attainment of a larger storage period for the solution.

Chemical Precipitation↗
PubMed1985

Rapid, automated identification of novobiocin-resistant, coagulase-negative staphylococci.

A modified automated method that uses the MS-2 system (Abbott Laboratories, Diagnostics Div., Irving, Tex.) to verify the reaction of coagulase-negative staphylococci to novobiocin is described. This technique permits the testing of a great number of specimens in an average time of 99 min and results in a 100% match with the traditional method of culturing.

Bacteriological Techniques↗
PubMed1982

[Modification of the basic stain of the Ziehl-Neelsen technic in the identification of Mycobacterium leprae].

Authors analyse the counterstain with methylene blue solution in the usual Ziehl-Neelsen method. Considerations are made on the characteristics of the dye substance. A technique alteration is proposed: a "concomitant alkalization" of the classic aqueous methylene blue solution, by adding some drops of sodium hydroxide solution, 1:500, on the slide at the moment of the staining. By this technique it was observed: a) a larger validity period of the solution; b) an absence of precipitate in the slides; c) an easier visualization of the substrate; d) a larger contrast among the substrate and the bacilli.

Humans↗
PubMedDate not supplied

Minute treatment with thiamphenicol in water for acute gonococcal urethritis in male patients.

Eighty-two male patients with acute gonococcal urethritis were given a single oral dose of 2.5 g of granulated thiamphenicol dissolved in water, and the results of treatment were evaluated after 48-72 hr and one week. Of the 76 patients who returned for the first follow-up examination, 75 (98.7%) no longer had Neisseria gonorrhoeae in urethral smears or cultures. Five of these patients did not return for the second follow-up examination, and another four who did return were found to be reinfected as a result of reexposure. Of the remaining 67 patients, 66 (98.5%) no longer had N. gonorrhoeae in urethral smears or cultures. Thus, the overall success rate among the 71 patients who completed the study (with the four cases of reinfection considered instances of failure of therapy) was 93%. The ease of administration, absence of adverse reactions, low failure rate, and low incidence of residual urethral secretions (4.5%) justify the use of thiamphenicol as the drug of choice for the treatment of acute gonococcal urethritis in male patients.

Acute Disease↗
PubMedDate not supplied

Thiamphenicol in the treatment of chancroid. A study of 1,128 cases.

Thiamphenicol, an aminic derivate of hydrocarbilsulfonil propandiol, was used for the treatment of 1,171 chancroid bearing patients. Each patient was medicated with 5.0 g of granulated thiamphenicol, orally, in a single dose, and was reevaluated 3, 7 and 10 days after the treatment. Ten patients (0.89%) did not respond to the proposed treatment. 133 patients presented healed ulcers after 3 days of treatment, 976 patients healed chancres on the seventh day after the treatment, and 39 patients took 10 days to present healed chancres. The results of this study indicate that the rate of patients that were cured, the low incidence of side effects, and the practicality of administration make of thiamphenicol an excellent choice for the treatment of chancroid.

Adolescent↗
PubMedDate not supplied

[Evaluation of parameters for laboratory diagnosis of genital female infection by Chlamydia trachomatis].

In order to evaluate the occurrence of Chlamydia trachomatis, we have examined samples of cervical swabs from 189 women (166 of which were symptomatic and the remaining 23 were asymptomatic with regard to chlamydial infection. Two specimens from the endocervical channel were collected and examined by immunofluorescent assay (DIF) and Chlamydia isolation. Detection of IgG and IgA antibodies specific to C. trachomatis was also effected by indirect immunofluorescent assay (IIF), in a cervical secretion sample. We succeeded in isolating chlamydia in 14 (8.4%) symptomatic and 3 (13%) asymptomatic women. The observation that the 152 symptomatic patients with negative results from chlamydia culture presented similar symptoms of disease, indicating that there is no specific symptom for genital infection caused by Chlamydia (p > 0.05). All the 13 (76.5%) positive endocervical specimens, as determined by cell culture and DIF reaction, presented more than 5 epithelial cells in the smears. These cells may represent an interference factor to the positivity of cell culture (p < 0.001). Antibodies of the IgG and/or IgA classes were detected in 11 (64.7%) out of 17 women with positive chlamydia culture, considering as positive the IIF titre of > or = 8. Consequently, this method can not be used as an alternative means of diagnosis, particularly in the earlier stages of chlamydial genital infections, since the presence of the antibodies depends on the phase of the infection and on the individual humoral immune response.

Adult↗