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Biomedical subjects

G Lucena

Publications and source records attributed to G Lucena.

5 recordsLinked to original sources
PubMed1987

Relationship between skin reactions to common allergens and non-specific bronchial reactivity in young healthy subjects.

In patients with respiratory symptoms, several studies have provided data supporting the hypothesis that there is a casual relationship between allergen exposure and variations in bronchial reactivity. In order to determine if this relationship holds when atopy is defined only on the basis of positive skin tests to common allergens, we compared bronchial reactivity in a group of twelve healthy subjects with positive skin tests and twenty-eight healthy subjects with negative tests. The two groups were comparable in terms of gender, age, smoking habits and family history of atopic diseases. The slopes of the dose-response curves, using airway conductance as an index of response, were similar in the two groups. Thus, in this healthy group of subjects, there was no relationship between skin and bronchial reactivity. It can be hypothesized that, if genetic factors determine bronchial reactivity, such reactivity might not be revealed until skin-test positive subjects have received repeated bronchial stimulation through inhalant allergens.

Adult↗
PubMed1975

Adjuvant effect on maintenance and escape from tolerence.

When mice are injected with deaggregated human gamma globulin (HGG), and HGG-tolerant state ordinarily is produced and persists despite subsequent challenges with an immunizing dose of HGG in saline or with an immunizing dose of HGG in Mycobacterium adjuvant. Subsequent administration of an immune elimination dose of radiolabeled HGG, at 27 days and 47 days does not break the tolerant state. Of special interest is the observation that when complete adjuvant containing increasing amounts of mycobacterial components was administered in conjunction with antigen very early in the tolerance induction phase 5 days after TID, it appears to prevent tolerance production. Mice challenged 5 and 17 days after the tolerance-inducing inoculation exhibit a statistically significant increase in circumvention of tolerance when compared with individuals challenged on the 7 and 17 day schedule. This increased circumvention of tolerance, as evidenced by 5 day challenge mice, seems to be related both to the mycobacterial content of the adjuvant and murine strain.

Animals↗
PubMedDate not supplied

X-ray survey for pulmonary tuberculosis and chest diseases in the Ok Tedi region of Western Province, Papua New Guinea.

X-ray photofluorography is a relatively expensive way to detect pulmonary tuberculosis (PTB). Those patients with suggestive positive chest X-ray still require Mantoux skin testing, blood tests and a positive sputum smear for the acid-fast bacillus Mycobacterium tuberculosis to make a definitive diagnosis of PTB. Photofluorography does detect most pulmonary pathological conditions, including lesions suggestive of PTB, and possible cardiac abnormalities. It is more cost-effective for large numbers in urban areas where there is poverty and overcrowding; and it is useful in early detection of cases of PTB. It is impractical to use in the isolated mountainous areas in the highlands region of Papua New Guinea and in Western Province, and where there is no road system. It cannot detect other forms of TB. In children and infants it is difficult to obtain good quality films and to interpret them. The scoring chart devised by Biddulph and Edwards is an excellent alternative where a diagnosis is not obvious in a chronically ill child. Active case detection by health workers in the field offers an excellent chance of finding TB cases. Although the cost of staining and looking at sputum smears and performing Mantoux tests can also be time consuming, these methods are relatively less expensive and more accurate. A simple method of processing sputum before Ziehl-Neelsen staining using ordinary household bleach vastly improves the detection rate of acid-fast bacilli. The new technology of demonstrating positive TB antigens in the blood of patients with active disease is still being assessed.

Humans↗