Immunological and electrophysiological studies of rat bone marrow-derived mast cells

Based on biochemical and functional characteristics, mast cells are broadly classified into mucosal and connective tissue phenotypes. Both types may be effector cells in the pathogenesis of allergic diseases, but intestinal mucosal mast cells (MMCs) are also involved in the immune response against intestinal nematodes. Rat bone marrow-derived mast cells (BMMCs), cultured in the presence of a T lymphocyte conditioned medium, are analogous to MMCs as defined by the granule content of the soluble chymase, rat mast cell protease-II (RMCP-II); by the granule proteoglycan chondroitin sulphate; and by their secretory characteristics. To investigate the secretory response of BMMCs to IgE-dependent stimulation, a sensitive, specific and repeatable enzyme-linked immunospot (ELISPOT) assay was developed to detect the release of RMCP-II from individual cells. Within populations of BMMCs, only 6-24% of the cells responded to challenge with either anti-IgE or specific antigen, leaving a large residual refractory population. Pre¬ incubation of mature BMMCs with the multi-functional cytokine, stem cell factor (SCF), significantly increased (~ 2-fold) the proportion of cells responding to IgEdependent stimulation without directly causing mediator release. Furthermore, SCF enhanced the total percentage release of RMCP-II and (3-hexosaminidase from populations of mature BMMCs in association with an increased proportion of cells secreting RMCP-II as detected by ELISPOT. These results suggest that SCF augments IgE-dependent secretion from rat BMMCs primarily by activating previously unresponsive cells.To further characterise the functional phenoiype of rat BMMCs, the electrophysiological properties of the cells were investigated using the whole-cell configuration of the patch-clamp technique. Rat BMMCs had a mean membrane potential of -28.5 mV and a mean whole-cell capacitance of 4.8 pF. With the amphotericin B perforated-patch technique, both inwardly rectifying (IR) and 11 outwardly rectifying (OR) currents were observed in rat BMMCs. The reversal potential and conductance of the IR current depended on the extracellular K+ concentration, indicating that the channel was K+ selective. The OR current was reversibly decreased both by lowering the extracellular CI" concentration and by the CI" channel blocker DIDS, indicating a CI" conductance. The IRK current could also be detected in the majority of BMMCs using the conventional whole-cell recording technique at room temperature. In contrast, the activity of the ORu current was dependent on temperature and the maintenance of cytoplasmic integrity. The ORc, current may be involved in voltage control of the cell during degranulation. However, in addition, the ORa current was influenced by changes in extracellular osmolality, suggesting a possible role in volume control.These studies provide further insight into the regulation of secretion in rat BMMCs, and therefore suggest mechanisms that may be involved in the modulation of gastrointestinal immune responses

Setting up and running a small fruit or vegetable processing enterprise

If you are interested in starting up a business, food processing offers an excellent opportunity to generate income using locally available resources. Focusing on the establishment of such a business using fruits and vegetables, this detailed and informative manual covers topics such as: products and processes (bottling, drying and picking), potential markets, equipment, facilities and quality assurance. Issues involved in the mangagement of your business – health and safety, staffing issues, finances and business strategy – are also addressed in an easy-to-follow, practical way. The result of collaboration between small business owners and advisers, this text provides an invaluable resource to both start-up enterprises and established entrepreneurs who wish to update and improve their businesses and profitablility. The guide should be read along with volume 1 in the series (see 1041), which introduces aspects such as technical know-how, business skills and customer care

Setting up and running a small meat or fish processing enterprise

Preface This handbook is the result of a collaborative effort by small business owners and advisers of small-scale food processors in ACP countries. The effort was supported by the ACP-EU Technical Centre for Agricultural and Rural Cooperation (CTA). The information contained in the handbook was gathered by researchers (see pp. 6-7), who surveyed local meat and fish processing enterprises and prepared reports that were then edited by Midway Consultants. The following specialists reviewed the draft publication and made valuable contributions to the text from the perspectives of their own countries: - Mr D. Anang, Head of Animal Science, University of Science and Technology, Kumasi, Ghana - Dr M. Dillon, Director, Grimsby Institute of Food and Fisheries, UK - Mr D. Harcourt, Director FOODTEK, Council for Scientific and Industrial Research, Pretoria, South Africa - Mr K. Matchell, Entrepreneur in Zimbabwe - Dr. W. Ssali, Director, National Agricultural Research Association, Kampala, Uganda. We hope this handbook will meet the needs of small-scale enterprises and the agencies that support them by providing technical and business information that was previously difficult to find, and by helping entrepreneurs to update and improve their businesses for the benefit of their consumers and, of course, their own profitability. If you find this handbook useful, please take a few minutes to complete the feedback form at the end of the book. Your comments and suggestions will be used to improve the later books in this series. The EditorsThis book covers products that can be manufactured by small-and medium scale enterprises. Products such as canned meat and fish... or frozen meals are not included, as the technologies are expensive and demand production on a very large scale level

Setting up and running a small-scale dairy processing business

This handbook is a collaborative effort by the researchers and authors listed above, but a large number of other people gave freely of their time to assist in its preparation and publication. We would particularly like to record our thanks to Chantal Giuot at CTA for her support, encouragement and constructive ideas, to Sue Hainsworth of Green Ink for copy-editing and proofreading the text, and to Christel Blank of Green Ink for the layout. We also wish to thank the following small-scale industrialists in Africa and the Caribbean for sharing their experiences of the problems and successes of operating their food processing enterprises, and in doing so, contributing to the success of others: Alfred Malijani, PO Box 320245, Lusaka, Zambia Anna J.H. Temu, Power Foods, opposite Kawa Tanganyika Packers, PO Box 23437, Dar es Salaam, Tanzania Charlotte Ayayee, Joecarl Enterprise Ltd, PO BT 398, Tema, Ghana Cheryl Rolle, Chi Chi Bees Yogurt, c/o J Garraway & Co. Ltd, PO Box 3, 19 Old Street, Roseau, Commonwealth of Dominica Chirstabel Malijani, Provincial Health Inspector, PO Box 37136, Lusaka, Zambia Claudia Mary Massawe, Clama Quality Product, PO Box 33496, Dar es Salaam, Tanzania M.T. Kaputo, Food Technology Research Unit, National Institute for Scientific and Industrial Research, PO Box 310158, Lusaka, Zambia Fafali Azaglo, Selasie Farms and Groceries, PO Box AN 7541, Accra, Ghana Florence Adejoh, Flokan Products, PO Box CT 460, Cantonment, Accra, Ghana G.M. Chingembu, CPL Kaposhi, PO Box 30060, Lusaka, Zambia Harrington Barigye, Information Officer, Uganda Manufacturers Association, PO Box 6966, Kampala, Uganda J. Chikonde, Proc-Press Enterprise Ltd, PO Box 50805, Lusaka, Zambia Janet Morio Mkonyi, Shesi Holdings, PO Box 5733, Ukonga, Dar es Salaam, Tanzania John Anglin, Paramount Dairies Ltd, PO Box 8414, Kampala, Uganda John Kyenkungu, New Northern Creameries, Plot 4–13 Block D Industrial Area, Unga Limited, PO Box 338, Arusha, Tanzania Laura Gonzalez Peltier, PIWI Enterprises Ltd, 17 Hillsborough Street, PO Box 1928, Roseau, Commonwealth of Dominica M. Chingembu, Kaposhi Farms, PO Box 30060, Lusaka, Zambia Margaret Kabasinguzi Nyanja Etagera Enterprises, Kampala, Uganda Markus Weltin, Majoru Investments Ltd, PO Box 36518, Lusaka, Zambia Maryline Simba, Simba Foods, PO Box 79360, Ubungo-Maziwa, Dar es Salaam, Tanzania Masoud Rizvi Fidahussein & Co., Vingunguti Industrial Area, PO Box 816, Dar es Salaam, Tanzania Mike Richards, Farm Rich Foods, Vieux Fort, St Lucia Mmari Devangwa Kivaria, Shekilango Road, PO Box 7911, Dar es Salaam, Tanzania Gregory Mongroo, Grew Ltd., PO Box 1050, Castries, Saint Lucia R. Mendes, Tropical Delights, PO Box GW584, Castries, Saint Lucia Narendrea Jamari, Tabisco Enterprises Ltd., Chang’ombe Industrial Area, PO Box 570, Dar es Salaam, Tanzania The Manager, GHERA Ltd, PO Box 296, Vieux Fort, Saint Lucia Thomas Lyimo, Tommy Dairy Farm Products, Morogoro Road, PO Box 71675, Dar es Salaam, Tanzania Wassin Naan Halawi, Halawi Holding Farm, c/o Dr Rodah Zulu, Food Technology Research Unit, National Council For Scientific Research, PO Box 310158, Airport Road, Chelston, Lusaka, Zambia Peter Fellows Barrie AxtellThe purpose of this book is to describe the activities that are needed to run a successful small-scale enterprise based on milk processing. This can be either processing fresh milk to preserve it for an extra few days, or ‘secondary’ processing to convert the milk into a range of different foods

Setting up and running a small fruit or vegetable processing enterprise

This handbook is the result of a collaborative effort by small business owners and advisers who support small-scale food processors in ACP countries, supported by the Technical Centre for Agricultural and Rural Cooperation ACP-EU (CTA). The information contained in the handbook was gathered by the researchers below, who surveyed local fruit and vegetable processing enterprises and prepared reports that were then edited by Midway Technology consultants. The following specialists reviewed the draft publication and made valuable contributions to the text from the perspectives of their own countries: Dave Harcourt, Council For Scienti?c and Industrial Research (CISIR FOODTEK) Pretoria, South Africa. Jane Nabawanuka, Kawanda Research Institute, National Agricultural Research Organisation (NARO), Uganda. Richard Beyer Consulting (Food Science), PO Box 363, Paci?c Harbour, Republic of the Fiji Islands.This book covers the important aspects of running a fruit or vegetable processing business, including choosing products, preparing a feasibility study, ?nding and developing suitable markets, selecting equipment, choosing a site and setting up the premises..