Effect of L-glutamic acid N,N-diacetic acid on the availability of dietary zinc in broiler chickens

Chelating agents can be used to improve the nutritional availability of trace minerals within the gastrointestinal tract. This study was conducted to determine the effect of a novel chelating agents, L-glutamic acid N,N-diacetic acid (GLDA), a biodegradable alternative to ethylenediaminetetraacetic acid on the nutritional bioavailability of zinc in broilers. Twelve dietary treatments were allocated to 96 pens in a randomized block design. Pens contained 10 Ross 308 male broilers in a factorial design with 6 incremental zinc levels (40, 45, 50, 60, 80, and 120 ppm of total Zn), with and without inclusion of GLDA (0 and 100 ppm) as respective factors. Experimental diets were supplied from day 7 to 21/22 and serum, liver and tibia Zn content were determined in 3 birds per pen. Growth performance and liver characteristics were not affected by dietary treatments, but both supplemental Zn and GLDA enhanced tibia and serum zinc concentration. The positive effect of GLDA was observed at all levels of the dietary Zn addition. The amount of zinc needed to reach 95% of the asymptotic Zn response was determined using nonlinear regression. When GLDA was included in the diet, based on tibia Zn, the same Zn status was achieved with a 19 ppm smaller Zn dose while based on serum Zn this was 27 ppm less Zn. Dietary GLDA reduces supplemental Zn needs to fulfill nutritional demands as defined by tibia Zn and serum Zn response. Considering the positive effect on the nutritional availability of Zn in broilers, GLDA presents an opportunity as biodegradable additive, to reduce Zn supplementation to livestock and thereby reducing Zn excretion into the environment, while fulfilling the nutrition Zn needs of farmed animals.

Effects of a feed additive blend on broilers challenged with heat stress

We evaluated a blend of medium-chain fatty acids (MCFA), organic acids, and a polyphenol antioxidant on gut integrity. Eighty Ross Broilers were exposed to 20-22°C (control - normothermic) or to 35-39.5°C (heat stress) for eight hours a day for a period of 1 or 5 days. Birds were fed a standard diet, or a diet supplemented with the test blend. Thereafter, birds were euthanized, and intestinal sections were excised for morphological, morphometric and gene expression analyses. Blood samples were collected for glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GSH-Px) activity and trolox equivalent antioxidant capacity (TEAC) determination. Heart and liver tissues were used to quantify the expression of heat shock proteins 60 and 70 (HSP60 and HSP70, respectively) and inhibitor of kappa light chain gene enhancer in B cells alpha (IKBA). The jejunum was the most sensitive intestinal section, where heat stress modulated the expression of HSP70, of the inflammatory markers IKBA, interleukin 8 (IL-8), interferon gamma (IFNγ), and toll-like receptor 4 (TLR4). Moreover, expression of tight junctions (CLDN1, ZO1 and ZO2) and nutrient transporters (PEPT1 and EAAT3) was modulated especially in the jejunum. In conclusion, the feed additive blend protected intestines during heat stress from the decrease in villus height and crypt depth, and from the increase in villus width. Especially in the jejunum, heat stress played an important role by modulating oxidative stress and inflammation, impairing gut integrity and nutrient transport, and such deleterious effects were alleviated by the feed additive blend. RESEARCH HIGHLIGHTS Jejunum is the most sensitive intestinal segment during heat stress. Heat stress affects the expression of tight junctions and nutrient transporters. Feed management helps to alleviate the disturbances caused by heat stress. A blend of MCFA, organic acids and a polyphenol protects broilers under heat stress.

[Combined vision and hearing impairment: in an estimated 30,000-35,000 people aged 55 years or over in The Netherlands]

OBJECTIVE

To determine the number of older people with acquired dual sensory impairment (DSI) in The Netherlands.

DESIGN

Combination of studies in the general population and in relevant subpopulations.

METHOD

Eight databases derived from recent studies on older persons with vision and hearing data on Dutch subjects aged 55 years or over were selected for further analysis. The measurement methods included self-reports, clinical measurements and observations. The prevalences of DSI were calculated for the general population, the non-institutionalised population, and subgroups such as older people in nursing homes and homes for the elderly. The calculated prevalences were extrapolated to the overall Dutch population.

RESULTS

For the non-institutionalised population of 55 years and older, the prevalences of acquired DSI in two different data sets were 0.4% (95% CI: 0.2-0.6) and 0.6% (95% CI: 0.3-0.8), respectively. Among the inhabitants of homes for the elderly these percentages were 5.4% (95% CI: 0.9-9.9) and 5.5% (95% CI: 3.8-7.2), and in nursing homes they were 12.7% (95% CI: 9.7-15.7) and 16.7% (95% CI: 14.6-18.8). Acquired DSI was most common in persons 85 years of age and older. It was estimated that the number of people aged 55 years and over with acquired DSI in The Netherlands is 30,000 to 35,000.

CONCLUSION

DSI is particularly a problem of the oldest old. An integrated approach to the visual and hearing problems of these subjects is essential.

How we do it: The Dutch functional hearing?screening tests by telephone and internet

Keypoints * The Dutch National Hearing Test is a reliable and very successful functional hearing-screening test by telephone. An internet version of the National Hearing Test was also implemented. * The National Hearing Test is a fully automatic adaptive speech-in-noise test that uses digit-triplets as speech material. The result of the test is given as 'good,''insufficient,' or 'poor.' * The test by telephone performs better in reaching older subjects, who are more likely to suffer from hearing loss, than the test by internet. * More than 50% of the participants who scored 'insufficient' or 'poor' followed the recommendation to visit a GP, hearing-aid dispenser, ENT specialist or Audiological Center. * The tests contribute to increase the identification and treatment of older hearing-impaired subjects.

Bim, Bad and Bmf: intrinsically unstructured BH3-only proteins that undergo a localized conformational change upon binding to prosurvival Bcl-2 targets

All BH3-only proteins, key initiators of programmed cell death, interact tightly with multiple binding partners and have sequences of low complexity, properties that are the hallmark of intrinsically unstructured proteins (IUPs). We show, using spectroscopic methods, that the BH3-only proteins Bim, Bad and Bmf are unstructured in the absence of binding partners. Detailed sequence analyses are consistent with this observation and suggest that most BH3-only proteins are unstructured. When Bim binds and inactivates prosurvival proteins, most residues remain disordered, only the BH3 element becomes structured, and the short alpha-helical molecular recognition element can be considered to behave as a 'bead on a string'. Coupled folding and binding is typical of many IUPs that have important signaling roles, such as BH3-only proteins, as the inherent structural plasticity favors interaction with multiple targets. This understanding offers promise for the development of BH3 mimetics, as multiple modes of binding are tolerated.

Paroxetine for pruritus in advanced cancer

Pruritus associated with malignancy may be one of the most bothersome symptoms in advanced cancer. Its control is still difficult to achieve and is a challenge to palliative medicine specialists. We describe five patients suffering from pruritus of different etiologies who responded rapidly to administration of paroxetine, a serotonin reuptake inhibitor, in a dose-dependent manner. Two patients experienced transient but severe nausea and vomiting. We suggest that paroxetine's antipruritic effect may be explained by rapid downregulation of the 5-HTs receptors, which may have an important role in the generation of pruritus and pain.

Low education is a genuine risk factor for accelerated memory decline and dementia

A relatively high prevalence and incidence of dementia have been found in population strata with low levels of education in comparison to population strata with high levels of education. However, doubt remains whether this may be an artifact of education bias in the screening tests used. To investigate this matter, we analyzed results of two Dutch population surveys in which unbiased measures of memory decline were used. In the Longitudinal Aging Study Amsterdam (n = 1774) the percentage of words retained in a verbal learning test was found to be disproportionately low in the oldest age cohort (80-85 years) with less than 11 years of education. The Amsterdam Study of the Elderly (n = 4051) found a "dose-response" relationship between education and dementia prevalence. Cross-sectional and longitudinal results showed that, in less educated people, memory decline is faster and sets in at an earlier age. These findings indicate that the relationship between dementia and education is not just an artifact of case detection methods.

[The development of an intake questionnaire for ambulatory care for the aged]

This article shortly presents current research on the development of two assessment questionnaires (a client questionnaire and an informers' questionnaire) developed for the RIAGG (Regional Institute of Community Mental Health Care)-Elderly Department. Background and purpose of the study are described and basic criteria of the content and form of the questionnaire are discussed. Finally the pilot-study is presented and the design of the main study.

Laser-Doppler determination of papillary blood flow in young and adult rats

Renal hemodynamics and renal blood flow autoregulatory ability differ in young (body wt 100 g) and adult (body wt 300 g) rats. Possible age-dependent changes in inner medullary hemodynamics have not been examined because it has not been possible to expose the papilla of adult rats for direct study of the vasa recta circulation. This study presents a technique for exposure of the papilla in any size rat. Seven days before an acute experiment, a small amount of cortical tissue overlying the papilla on the dorsal surface of the kidney was removed. The creation of this papillary window allowed for exposure of the papilla in adult rats after removal of the ureter. Using this preparation, we compared papillary blood flow in young and adult rats using a Periflux differential laser-Doppler flowmeter (Perimed, Stockholm, Sweden). The meter was calibrated by comparing the signal obtained from the papilla of 28 rats with papillary flow measured from the accumulation of 51Cr-labeled erythrocytes in the papilla. The laser-Doppler flow signal was linearly related and highly correlated (r = 0.92) to the red cell flow into the papilla. Comparisons of laser-Doppler flow signals obtained from the papilla of young and adult animals indicated that papillary blood flow was approximately 2-fold greater in the adult rats than in the young animals. This finding was associated with an enhanced maximal urine concentrating ability found in the younger rats. These studies demonstrate the utility of the laser-Doppler flowmeter for the assessment of papillary blood flow and suggest that inner medullary hemodynamics differ in young and adult rats.

Changes in hypnotic usage in residential homes for the elderly: a longitudinal study

The use of hypnotic drugs in 25 local authority homes for the elderly was recorded on a 1-day point prevalence study following a 6-mth monitoring programme involving all new admissions. From a total population of 1114 residents 390 (35%) were taking hypnotics on the night of the survey, showing a slight increase from similar surveys carried out in 1980 and 1981. The proportion of residents receiving hypnotics within each home varied from 0.0 to 61.8%. Correlation with levels of usage in the previous surveys was low, suggesting that pattern of hypnotic usage may change considerably over time within individual homes. Of the 156 residents who were admitted as permanent residents during the 6-mth period preceding the survey, 56 (35.9%) had been taking hypnotics on admission. Both the results of the drug monitoring programme and the survey show an association between hypnotic usage and source of admission: residents admitted from hospital being more likely to be taking sleeping tablets. A considerable change was found in the type of hypnotic currently prescribed with an increased preference being shown for short half-life hypnotics. A higher proportion of residents also were prescribed lower doses of hypnotics than previously, suggesting an increased awareness of the risks associated with hypnotic use in the elderly.