An evaluation of Gambusia affinis and Bacillus thuringiensis var. israelensis as mosquito control agents in California wild rice fields

The mosquito control potential of the mosquitofish and Bacillus thuringiensis var. israelensis (Bti) were evaluated in experimental wild rice fields in Lake County, California. Fields were assigned one of six treatment: control, 1.1 kg/ha G. affinis, 3.4 kg/ha G. affinis, Bti only (6 kg/ha Vectobac granules), 1.1 kg/ha G. affinis plus Bti and 3.4 kg/ha G. affinis plus Bti. Gambusia affinis, at both release rates, significantly reduced the mosquito population at densities exceeding 100 fish/minnow trap. Treatments with Bti significantly reduced larval population; however, the populations in the fields without fish rebounded to pretreatment levels within two weeks. In fields stocked with G. affinis and treated with Bti, populations remained low after Bti treatment. Nontarget populations of arthropods were significantly lower in fields stocked with G. affinis than in fields without fish on one or more sampling dates.     

Propene polymerization with δ-TiCl3/AlCl(C2H5)2 and δ-TiCl3/Al(C2H5)3 catalyst systems, 1. Effect of external donors

The effect of ethyl benzoate (EB), diisobutyl phthalate (DIBP), dibutyl ether (DBE) and triethoxy(phenyl)silane (EPS) as third components on the propene polymerization with the catalyst systems δ-TiCl₃/AlCl(C₂H₅)₂ and δ-TiCl₃/Al(C₂H₅)₃ was investigated. The influence of external donors on the isotacticity, catalyst activity and average molecular weight (M _v) was tested. If external donors are employed, M _v decreases, the insoluble fraction in boiling isooctane increases and the catalyst activity is strongly influenced by the mole ratio external donor/TiCl₃. The results indicate that all external donors employed have the same qualitative effect on catalytic active centers.     

Predictors of poliomyelitis case confirmation at initial clinical evaluation: implications for poliomyelitis eradication in the Americas.

In 1985, the Pan American Health Organization adopted the goal of eradication of poliomyelitis from the Americas by 1990. Strategies to accomplish this included high vaccination coverage, aggressive outbreak control, and active surveillance for acute flaccid paralysis (AFP). Although the sensitivity of AFP surveillance for detecting paralytic poliomyelitis cases is high, studies have shown the specificity to be low. In 1990, 2497 notified cases of AFP were investigated in the Americas of which 2146 had stool specimens collected. However, only 18 were confirmed as poliomyelitis by isolation of wild poliovirus from stool specimens, 71 were classified as being compatible with poliomyelitis. Cases of AFP due to causes other than poliomyelitis result in extensive but unnecessary outbreak control measures. To predict, at initial clinical evaluation, the likelihood of future confirmation as a case of poliomyelitis, likelihood ratios (LR) were calculated for different combinations of clinical characteristics of AFP cases (249) from Mexico in 1989 and 1990. The best predictors in a child with AFP were proximal muscle involvement which progressed '4 days together with fever at onset of paralysis, and proximal and unilateral involvement with either fever at onset or paralysis which progressed '4 days. The odds would increase by 12 that the child would eventually be confirmed as poliomyelitis (19), based on a stool culture positive for wild poliovirus (95% confidence interval (CI) 2.6-55.9). A guide for use in the field is proposed whereby local health officials, often with little training in neurological evaluation, can predict at initial clinical examination the likelihood that an AFP case will subsequently be confirmed as poliomyelitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cellular mechanism of the conduction abnormalities induced by serum from anti-Ro/SSA-positive patients in rabbit hearts.

In this study, IgG fractions from sera of SLE patients with anti-Ro/SSA or anti-Ro/SSA and anti-La/SSB activity were tested in Langendorff preparations of adult rabbit hearts, aiming to reproduce the cardiac manifestations observed in neonatal lupus in an experimental model. The hearts were perfused with normal Tyrode's solution for 30 min, followed by perfusion with Tyrode's containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (nine sera), anti-ribonucleoprotein (RNP)-positive IgG (five sera), or IgG fractions from normal donors (five sera). In one third of the experiments done with anti-Ro/La-positive IgG, heart block was observed. With the remaining fractions, a decrease in heart rate of 17.1% was observed, but normal sinus rhythm was maintained. The IgG fractions with anti-RNP activity (five experiments) and from normal sera (six experiments) reduced heart rates by 12.9 and 3.3%, respectively, but heart block was not observed. To further characterize the cellular mechanisms involved in the conduction disturbances observed in the whole rabbit hearts, we conducted experiments with ventricular myocytes isolated from young rabbit hearts, studied by whole cell patch-clamp technique. In these experiments, the slow inward currents were analyzed during the superfusion of the cell with normal Tyrode's solution and 5 min after superfusion with Tyrode's solution containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (five sera), anti-RNP-positive IgG (three sera), or IgG from normal donors (four sera). Resting and action potential amplitudes were not affected by any of the sera used. The anti-Ro/SSA IgG fraction induced a mean reduction in the peak slow inward current of 31.6%. IgG fractions with anti-RNP activity reduced slow inward current by 4.4%, whereas IgG fractions from normal donors increased this current by 3.3%. IgG-free fractions from sera of patients with anti-Ro/SSA activity did not alter the peak slow inward current. These results show, for the first time, that the presence of anti-Ro/SSA or anti-Ro/SSA and anti-La/SSB antibody activity in IgG fractions from lupus patients' sera can induce cardiac conduction disorders similar to those observed in neonatal lupus.     

Access to primary health care for Australian young people: service provider perspectives.

BACKGROUND: To adequately address the complex health needs of young people, their access to services, and the quality of services received, must be improved. AIMS: To explore the barriers to service provision for young people and to identify the training needs of primary healthcare service providers in New South Wales (NSW), Australia. DESIGN OF STUDY: A cross-sectional, qualitative study of the perspectives of a range of health service providers. SETTING: A range of primary healthcare organisations across NSW. METHODS: Samples of general practitioners (GPs), youth health workers, youth health coordinators, and community health centre staff were drawn from urban and rural clusters across NSW. Focus groups and interviews were used to identify barriers to service provision and the training needs of service providers. Data were tape recorded, transcribed, and analysed. RESULTS: Barriers to service provision among GPs and community health centre staff included inadequate time, flexibility, skills, and confidence in working with young people, and poor linkages with other relevant services. Training needs included better knowledge of and skills in adolescent health requirements, working with adolescents, and working with other services. Barriers to service provision for youth health workers and coordinators included lack of financial resources and infrastructure. There were few linkages between groups of service providers. CONCLUSION: Models of service provision that allow stronger linkages between service providers, sufficient time for consultation with young people, adequate training and support of health professionals, and flexibility of service provision, including outreach, should be explored and evaluated.     

Fibrolamellar carcinoma of the liver in a child: ultrastructural and immunohistologic aspects

We describe a fibrolamellar carcinoma of the liver in a 12-year-old girl and review the literature concerning the occurrence of this distinct hepatic neoplasm in children up to the age of 16 years. The results of our electron microscopic and immunohistologic studies suggest that some cells of this tumor exhibit neuroendocrine differentiation. This finding has important theoretical implications relative to the tumor's histogenesis and practical implications with respect to the search for tumor markers of clinical usefulness and possibly for therapy.     

Epithelioid sarcoma. Flow cytometric study of DNA content and regional DNA heterogeneity.

The DNA content and regional DNA heterogeneity in correlation with clinicopathologic parameters and patient survival were investigated in epithelioid sarcoma. Such neoplasms preponderantly manifest diploid DNA content and a remarkably stable intratumoral and intertumoral DNA content. Small tumor size (less than 5.0 cm) and low S-phase fraction (less than 5%) were significant prognostic factors in this study. Ploidy status, mitotic rate, age, and postsurgical treatment were not significantly correlated with survival.     

The effects of menstrual phase and nicotine abstinence on nicotine intake and on biochemical and subjective measures in women smokers: a A preliminary report

Nicotine intake, menstrual and smoking withdrawal symptomatology, and baseline cortisol and MHPG were assessed in nine women smokers under conditions of ad lib smoking and overnight abstinence in three menstrual phases (early follicular, mid-to-late follicular, and late luteal). A trend towards higher nicotine intake p <0.100 was observed in the mid-to-late follicular phase. Although me menstrual symptomatology was not significantly elevated during the smoking abstinence condition overall, abstinence appeared to prevent the normal reduction in symptomatology during the mid-to-late follicular phase that occurred under conditions of ad lib smoking. Menstrual and withdrawal symptoms were highly correlated, and both were most pronounced during the late luteal/abstinence condition. The smoking-specific item “craving” reflected this pattern, though in attenuated form, suggesting that the observed exacerbation of withdrawal symptomatology was not simply due to generalized dysphoria, as queried in both instruments. MHPG was significantly elevated in the late luteal phase, whereas cortisol was significantly higher during ad lib smoking than during abstinence and tended to be highest in the mid-to-late follicular phase. Further investigation will be needed to determine the functional significance of these findings for understanding and treating smoking in women.