Predictors of discordant tuberculin skin test and QuantiFERON®-TB Gold In-Tube results in various high-risk groups.

SETTING: Persons in whom targeted testing for latent tuberculosis infection (LTBI) is recommended in Seattle, Washington; Atlanta, Georgia; and central North Carolina, United States. OBJECTIVE: To compare the performance of an interferon-gamma release assay (QuantiFERON®-TB Gold In-Tube [QFT-GIT]) with the tuberculin skin test (TST) among foreign-born, homeless, human immunodeficiency virus (HIV) infected and substance abuse persons tested for LTBI. DESIGN: A cross-sectional study requiring participants to have a blood test, a TST and data collected. RESULTS: Of 1653 persons, 19.5% were TST-positive and 14.0% were QFT-GIT-positive. Overall concordance was moderate (kappa 0.53; 95%CI 0.47-0.58). Compared to concordant positive results, TST+/QFT-GIT- discordance was associated with HIV infection and sex, while TST-/QFT-GIT+ discordance was associated with HIV and inversely associated with foreign birth. Compared to concordant negative results, TST-/QFT-GIT+ discordance was associated with foreign birth and age ≥50 years, while TST+/QFT-GIT-discordance was associated with foreign birth, age 30-49 years, being Black and inversely associated with HIV. HIV infection was significantly associated with indeterminate QFT-GIT results. CONCLUSION: QFT-GIT may be an improvement over the TST for diagnosing LTBI in foreign-born and older persons, and may be as useful as the TST in HIV-infected persons. The sensitivity of both tests may be low in HIV-infected persons.

Bacteremia caused by Gordonia bronchialis in a patient with sequestrated lung.

Gordonia species have been recognized as pathogens in immunocompromised and immunocompetent patients. We report the first case of bacteremia due to Gordonia bronchialis in a diabetic patient with a sequestrated lung. Species identification was confirmed with mycolic acid analysis by high-performance liquid chromatography and sequencing of the 16S rRNA gene.

[Breast feeding and weaning: a survey in rural communities of Mexico]. / Lactancia materna, destete y ablactación: una encuesta en comunidades rurales de México.

OBJECTIVE: To determine the prevalence of lactation, the use of industrialized milk and weaning, and the factors related to lack of breast-feeding and early weaning in young infants of rural communities. MATERIAL AND METHODS: Transversal study performed by last year medical students doing Social Service in 222 rural communities in Mexico who applied structured interviews to 5,409 families with children younger than 1 year of age. RESULTS: The percentages of children who were never breast-fed were: in the north (N) 21.4%, in the center (C) 7.6% and in the south (S) 5.3%. Children who were still being breast-fed, either exclusively or with mixed feeding by the third trimester were 35.6% (N), 67.6% (C) and 77.5% (S); in the second trimester, 67.2% (N), 40.9% (C) and 51.6% (S) had been weaned. In the N region it was observed that lack of breast-feeding was associated to the health personnel who attended delivery, mothers with six or more years of education and less than four children, dwellings with permanent material floors, two or more household commodities and a head of the family different from the father. Early weaning was essentially associated to the same factors; additionally, to the child being taken care of by someone different from the mother, artificial lactation by parental decision or due to medical recommendation and the use of health services provided by social security or private physicians. CONCLUSIONS: Artificial lactation and early weaning are typical of small families, with high educational level of the mother, better living conditions and contact with medical personnel, especially in the N of the country. Children are weaned before the second semester of life and it is therefore deemed necessary to implement health programs which promote breast-feeding and gradual weaning after the sixth month of life among the infant population of Mexican rural communities.

Control of Culex quinquefasciatus in pit latrines, using shredded, waste polystyrene.

As an alternative to the use of commercially available, expanded-polystyrene beads, a study was made of the effectiveness of shredded, waste polystyrene (SWAP) for the control of Culex quinquefasciatus. The relevant physical properties of the SWAP were first investigated in the laboratory. Then, under field conditions in wet pit latrines, mosquito emergence rates were measured before and after application of the material. In the laboratory, when compared with the commercial product, the irregular shape of the SWAP particles greatly reduced their capacity to spread over the water surface and the interstitial air spaces also permitted respiration and development of mosquito larvae. Nevertheless, under field conditions, with careful application of the SWAP over the water surfaces in wet pit latrines, almost complete control of mosquito breeding was observed within a few days. This was sustained for 60 days, at which time observations were discontinued. SWAP appears to offer an effective, cheap and readily available alternative to the commercial product for the control of C. quinquefasciatus. The practicality of using it in community-based, mosquito-control programmes warrants further study.

Control of Culex quinquefasciatus in pit latrines, using shredded, waste polystyrene

As an alternative to the use of commercially available, expanded-polystyrene beads, a study was made of the effectiveness of shredded, waste polystyrene (SWAP) for the control of Culex quinquefasciatus. The relevant physical properties of the SWAP were first investigated in the laboratory. Then, under field conditions in wet pit latrines, mosquito emergence rates were measured before and after application of the material. In the laboratory, when compared with the commercial product, the irregular shape of the SWAP particles greatly reduced their capacity to spread over the water surface and the interstitial air spaces also permitted respiration and development of mosquito larvae. Nevertheless, under field conditions, with careful application of the SWAP over the water surfaces in wet pit latrines, almost complete control of mosquito breeding was observed within a few days. This was sustained for 60 days, at which time observation were discontinued. SWAP appears to offer an effective, cheap and readily available alternative to the commercial product for the control of C. quinquefasciatus. The practicality of using it in community-based, mosquito-control programmes warrants further study.(AU)

[Contraceptives, HIV, and other sexually transmitted diseases]. / Anticonceptivos, VIH y otras enfermedades de transmisión sexual.

The large majority of women who acquire Human Immuno-Deficiency Virus (HIV) and other sexually transmitted diseases (STDs) are in their childbearing years and are current or potential users of contraceptive methods. Certain STDs augment women's risk for HIV due to damage which these diseases produce in the integrity of the epithelial lining of the vagina and the vulva. There also exists evidence that some contraceptive methods, such as the intrauterine device and certain hormonal products, may increase the risk of HIV and other STDs. Condoms and spermicides offer good levels of protection against these diseases, but are not highly effective contraceptives. The interrelations among these risks are important and create a great problem for women's reproductive health. Moreover, the high vulnerability of the female population for these diseases is also related to a variety of social factors which are referred to as gender relations (power of females in society relative to that of females). Among the gender-related inequalities which affect women are their lack of power to successfully control many aspects of sexual relations. Another problem has to do with the fact that there are no highly reliable female controlled methods for preventing infection by HIV and other STDs. Improvement in the reproductive health care of women depends on the development of new disease prevention products and structural changes in the delivery of care, as well as continued research efforts on the interrelations among contraceptive methods, HIV and other STD.

PIP: Until recently, some behaviors were viewed as entailing a high risk of HIV infection, but HIV is now considered a great risk for the female population in general. The number of HIV infected women is increasing rapidly even in areas such as Mexico and South America where women form a minority of AIDS patients. Most women infected with HIV and other sexually transmitted diseases (STDs) are sexually active and at risk of pregnancy. Some STDs, notably those producing genital ulcers, increase the risk of HIV infection. It is not yet known whether STDs not producing ulcers also increase the risk. There is controversy over the extent to which specific contraceptive methods increase or perhaps reduce the risk of HIV infection. Some unconfirmed assumptions are that the cervical ectopy produced by oral contraceptives (OCs) results in affected zones more vulnerable to trauma and thus perhaps to HIV infection, and that combined OCs by reducing menstrual bleeding also reduce risk of infection. OCs containing only progestins may increase the risk of transmission by inducing irregular bleeding, thickening the cervical mucus, and thinning the vaginal epithelium. Injectables may increase risk by increasing bleeding, thinning the vaginal epithelium, or through use of contaminated needles in application. IUDs may increase menstrual bleeding and are not advisable in any event for women at high risk of other STDS. Condoms and spermicides offer some protection against STDs, but are not highly effective contraceptives. The interrelations between risk of pregnancy and of disease are a great and largely unresolved problem in women's reproductive health. Few family planning services are able to address prevention of STDs and especially AIDS adequately. Methodological and logistical problems impede study of the interrelations between contraception and STDs, and resources are limited. Studies of commercial sex workers in different countries have offered a partial solution. Women's lack of power to negotiate successfully concerning sexual relations and their lack of access to a means of preventing STDs under their own control are factors in their vulnerability. Improved reproductive health of women will require development of new products to control disease, structural changes in health services, and continued research.

[Dietary fiber and gastro-intestinal tumors, implications for the Mexican population]. / Fibra dietética y tumores gastrointestinales, implicaciones para la población mexicana.

Certain nutrients serve as individual influences in the development or protection against chronic and/or degenerative diseases. Specifically, it has been observed that the abundant consumption of dietetic fiber is a protective factor against tumors of the digestive system. Many scientific articles have reported mechanisms by which dietetic fibers exert an important protective effect for colon cancer and in lesser degree against cancer of the stomach and rectum. In Mexico during 1990, neoplasms were the second cause of general mortality for the persons over the age of 65 years. The Fourth National Report of Cancer in Mexico revealed that tumors of the digestive tube were the third most frequent type of neoplasm in the country and that stomach cancer had the greatest incidence among cancers which affect this system. To date, we do not know how much the urban immigration and the consequent changes in food patterns have acted as cofactors for the increase in this type of tumors. During the seventies, a number of national and regional nutritional surveys showed that the Mexican population had a high consumption of fiber, as part of the traditional diet, comprised primarily of tortilla and beans. At the present time, the national dietary patterns have changed; the increasing consumption of high energy foods with a low nutritional value is associated with much less ingestion of dietary fiber. This article points out that the population may have additional digestive cancer risks, due to new food consumption patterns which have reduced the availability of dietary fiber.

[The program for the promotion of breast feeding in the Hospital General de México: an evaluation study]. / Programa de promoción de la lactancia materna en el Hospital General de México: un estudio evaluativo.

The malnutrition and infection seen in the infant population can be reduced with correct breast feeding practice. In 1988 and 1989, La Leche League of Mexico and the Mexico City General Hospital, Secretary of Health, carried out a breast feeding promotion program in the same hospital. The program had three components: 1) in-service training for health care personnel in the pediatric and obstetric services; 2) changes in perinatal care procedures aimed at improving the start of maternal nursing during the hospital stay; and 3) classes concerning breast feeding advantages and techniques for primiparas. As a result of the program, 110 hospital workers received lactation management training and there was improvement in several breast feeding related indicators measured during the post-partum hospital stay (reduction in the mean time between the arrival of the newborn to the rooming-in area and first maternal nursing, greater proportion of infants observed receiving the breast, and a better interaction between mothers and newborns when offering the breast) and the primiparas who participated in the program breast fed their infants for longer periods than did a program control group (median of 17 and 12 weeks, respectively; the difference in the proportion of infants still being nursed at 16 weeks was statistically significant).

Mutagenicity of cyclopenta-fused isomers of benz(a)anthracene in bacterial and rodent cells and identification of the major rat liver microsomal metabolites.

The microsomal metabolites and mutagenic activity of four cyclopenta-fused benz(a)anthracenes, benz(j)aceanthrylene [B(j)A], benz(e)aceanthrylene [B(e)A], benz(l)aceanthrylene [B(l)A], and benz(k)acephenanthrylene [B(k)A], have been studied. Aroclor 1254-induced rat liver microsomes metabolized B(j)A to B(j)A-1,2-dihydrodiol, B(j)A-9,10-dihydrodiol, B(j)A-11,12-dihydrodiol, and 10-hydroxy-B(j)A; B(e)A-1,2-dihydrodiol, B(e)A-3,4-dihydrodiol, and B(e)A-5,6-dihydrodiol; B(l)A to B(l)A-1,2-dihydrodiol, B(l)A-4,5-dihydrodiol, and B(l)A-7,8-dihydrodiol; and B(k)A to B(k)A-4,5-dihydrodiol and B(k)A-8,9-dihydrodiol. With each polycyclic aromatic hydrocarbon, metabolism occurred on the cyclopenta ring. All four isomers were active as gene mutagens in Salmonella typhimurium and in Chinese hamster V79 cells. In the S. typhimurium mutation studies, using Aroclor 1254-induced rat liver S9, B(j)A, B(e)A, and B(l)A required significantly less microsomal protein for maximal mutation response than B(k)A and B(a)P, suggesting a one-step activation mechanism, presumably on the cyclopenta-fused ring. B(j)A, B(e)A, and B(l)A were significantly more mutagenic than B(k)A and B(a)P in S. typhimurium. In the Aroclor 1254-induced rat liver S9-mediated V79 mutagenesis system, all four isomers were active, with B(l)A the most active. When Syrian hamster embryo cells were used as the metabolic activation component for V79 cells, only B(l)A produced a significant response and was equivalent in activity to B(a)P. A helical configuration for B(l)A is inferred from the identification of two trans-B(l)A-1,2-dihydrodiols, syn and anti, which have been synthesized, separated, and characterized. The metabolically formed dihydrodiol is anti-trans-B(l)A-1,2-dihydrodiol, and experimental evidence suggests that the metabolically formed B(l)A-1,2-oxide is the anti-isomer. Synthetic B(l)A-1,2-oxide was found to be a direct-acting mutagen in S. typhimurium and Chinese hamster V79 cells and is estimated to account for up to 40% of the mutagenic activity of the parent hydrocarbon. Therefore, certain cyclopenta-ring fusions on benz(a)anthracene appear to markedly increase its genotoxic and carcinogenic activities.