Evaluation of a cooking skills programme in parents of young children--a longitudinal study.

OBJECTIVE: To evaluate longitudinally the effectiveness of a cooking programme on self-reported confidence about cooking skills and food consumption patterns in parents of young children. DESIGN: An evaluation of cooking programmes delivered by National Health Service (NHS) community food workers using a single group pre-test/post-test repeated measures design. A shortened version of a validated questionnaire at baseline, post intervention and 1-year follow-up determined confidence in cooking using basic ingredients, following a simple recipe, tasting new foods, preparing and cooking new foods on consumption of ready meals, vegetables and fruit. SETTING: Deprived communities in Ayrshire and Arran, Scotland. SUBJECTS: Parents of nursery age children, 97 % were female and <45 years old. RESULTS: One hundred and two participants had completed baseline and post-intervention questionnaires. Forty-four participants contacted by telephone completed a follow-up questionnaire. In participants who completed all questionnaires (n 44), median confidence in four aspects of cooking increased significantly from baseline to post intervention (P < 0·001) but was retained at 1-year follow-up only for following a simple recipe and preparing and cooking new foods. Improved food consumption patterns were reported from baseline to post intervention (ready-meal consumption reduced from 2-4 times/week to 1 time/week, P < 0·001; vegetable consumption increased from 5-6 times/week to 1 time/d, P < 0·001; fruit consumption increased from 5-6 times/week to 1 time/d, P < 0·001) and remained at 1-year follow-up. CONCLUSIONS: The cooking programmes appeared to improve cooking confidence and food consumption patterns in the target group and some of these changes were retained after 1 year.

Specificity of the volume-activated amino acid efflux pathway in cultured human breast cancer cells.

It has been shown that cell swelling stimulates the efflux of taurine from MCF-7 and MDA-MB-231 cells via a pathway which has channel-like properties. The purpose of this study was to examine the specificity of the volume-activated taurine efflux pathway in both cell lines. A hyposmotic shock increased the efflux of glycine, L-alanine, AIB (α-aminoisobutyric acid), D-aspartate but not L-leucine from MDA-MB-231 and MCF-7 cells. It was evident that the time course of activation/inactivation of those amino acids whose efflux was affected by cell swelling was similar to that of volume-activated taurine efflux. The effect of exogenous ATP on swelling-induced glycine, AIB and D-aspartate efflux from MDA-MB-231 cells was similar to that found on taurine efflux. In addition, volume-activated AIB efflux from MDA-MB-231 cells, like that of swelling-induced taurine efflux, was inhibited by diiodosalicylate. Tamoxifen inhibited volume-activated taurine release from both MDA-MB-231 and MCF-7 cells. The results suggest that neutral and anionic α-amino acids are able to utilize the volume-activated taurine efflux pathway in both cell lines. The effect of tamoxifen on breast cancer growth may, in part, be related to perturbations in cell volume regulation.

Inhibition of system L (LAT1/CD98hc) reduces the growth of cultured human breast cancer cells.

It has been suggested that system L (LAT1/CD98hc) is up-regulated in cancer cells, including breast tumour cells, and is therefore a promising molecular target to inhibit or limit tumour cell growth. In view of this, we have examined the effect of BCH and other inhibitors of system L on the growth of MCF-7, ZR-75-1 and MDA-MB-231 cells. Treating cells with BCH markedly inhibited the metabolism of WST-1 in a dose-dependent fashion. Similarly, melphalan and D-leucine inhibited the growth of cultured breast cancer cells whereas MeAIB, an inhibitor of system A, was without effect. The effects of BCH and melphalan on cell growth were non-additive suggesting that both compounds were acting at a single locus. The results indicate that system L is required to maintain MCF-7, ZR-75-1 and MDA-MB-231 cell growth and support the notion that LAT1/CD98hc may be a suitable target to inhibit breast cancer progression.

Calcium transport by mammary secretory cells: mechanisms underlying transepithelial movement.

The secretion of calcium into milk by mammary epithelial cells is a fundamentally important process. Despite this, the mechanisms which underlie the movement of calcium across the lactating mammary gland are still poorly understood. There are, however, two models which describe the handling of calcium by mammary epithelial cells. On the one hand, a model which has existed for several decades, suggests that the vast majority of calcium enters milk via the Golgi secretory vesicle route. On the other hand, a new model has recently been proposed which implies that the active transport of calcium across the apical membrane of mammary secretory cells is central to milk calcium secretion. This short review examines the strengths and weaknesses of both models and suggests some experiments which could add to our understanding of mammary calcium transport.

Swelling-induced taurine transport: relationship with chloride channels, anion-exchangers and other swelling-activated transport pathways.

Cells have to regulate their volume in order to survive. Moreover, it is now evident that cell volume per se and the membrane transport processes which regulate it, comprise an important signalling unit. For example, macromolecular synthesis, apoptosis, cell growth and hormone secretion are all influenced by the cellular hydration state. Therefore, a thorough understanding of volume-activated transport processes could lead to new strategies being developed to control the function and growth of both normal and cancerous cells. Cell swelling stimulates the release of ions such as K(+) and Cl(-) together with organic osmolytes, especially the beta-amino acid taurine. Despite being the subject of intense research interest, the nature of the volume-activated taurine efflux pathway is still a matter of controversy. On the one hand it has been suggested that osmosensitive taurine efflux utilizes volume-sensitive anion channels whereas on the other it has been proposed that the band 3 anion-exchanger is a swelling-induced taurine efflux pathway. This article reviews the evidence for and against a role of anion channels and exchangers in osmosensitive taurine transport. Furthermore, the distinct possibility that neither pathway is involved in taurine transport is highlighted. The putative relationship between swelling-induced taurine transport and volume-activated anionic amino acid, alpha-neutral amino acid and K(+) transport is also examined.

Estrogen regulation and ion dependence of taurine uptake by MCF-7 human breast cancer cells.

It has been reported that estrogen receptor-positive MCF-7 cells express TauT, a Na(+)-dependent taurine transporter. However, there is a paucity of information relating to the characteristics of taurine transport in this human breast cancer cell line. Therefore, we have examined the characteristics and regulation of taurine uptake by MCF-7 cells. Taurine uptake by MCF-7 cells showed an absolute dependence upon extracellular Na(+). Although taurine uptake was reduced in Cl(-) free medium a significant portion of taurine uptake persisted in the presence of NO(3) (-). Taurine uptake by MCF-7 cells was inhibited by extracellular beta-alanine but not by L-alanine or L-leucine. 17ß-estadiol increased taurine uptake by MCF-7 cells: the V(max) of influx was increased without affecting the K(m). The effect of 17ß-estradiol on taurine uptake by MCF-7 cells was dependent upon the presence of extracellular Na(+). In contrast, 17ß-estradiol had no significant effect on the kinetic parameters of taurine uptake by estrogen receptor-negative MDA-MB-231 cells. It appears that estrogen regulates taurine uptake by MCF-7 cells via TauT. In addition, Na(+)-dependent taurine uptake may not be strictly dependent upon extracellular Cl(-).

Osmoregulation of taurine efflux from cultured human breast cancer cells: comparison with volume activated Cl- efflux and regulation by extracellular ATP.

The properties and regulation of volume-activated taurine efflux from MDA-MB-231 and MCF-7 cells have been investigated. Volume-activated taurine release from both cell lines was almost completely inhibited by diidosalicylate. DIDS , was more effective at inhibiting swelling-induced taurine release from MCF-7 than from MDA-MB-231 cells. On the basis of comparing taurine, Cl(-) and I(-) efflux time courses, it appears that volume-activated taurine efflux does not utilize volume-sensitive anion channels in MDA-MB- 231 and MCF-7 cells. Extracellular ATP stimulated volume-activated taurine release from MDA-MB-231 cells but not from MCF-7 cells. The effect of ATP was mimicked by UTP and was dependent upon external calcium and inhibited by suramin. However, suramin inhibited volume-activated taurine efflux from both MDA-MB-231 and MCF-7 cells even in the absence of exogenously added ATP suggesting that it acts directly on the taurine efflux pathway and/or is inhibiting the effect of ATP released from the cells. Volume-activated taurine efflux from MDA-MB-231 cells was stimulated by ionomycin. In contrast, ionomycin had no effect on taurine release from MCF-7 cells. Adenosine also stimulated volume-activated taurine efflux from MDA-MB-231 cells. The results suggest that purines regulate taurine transport in MDA-MB- 231 cells via more than one type of receptor.