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R L Baker

Publications and source records attributed to R L Baker.

76 records · Page 5Linked to original sources
PubMedDate not supplied

Prospects of breeding small ruminants for resistance to internal parasites.

Resistance to nematode parasites can be improved by selection, but efforts to include appropriate traits in commercial livestock breeding programs are only a recent development. Procedures for including resistance in breeding programs are similar to those involving other traits. The steps are described with special reference to sheep, and areas are highlighted where particular considerations exist. Three approaches are described and contrasted: breeding for resistance (reduced parasite numbers, as determined by faecal worm egg count); resilience (production during parasitism); or number of treatments required during parasitism. It is necessary, but difficult, to assess the economic benefits of improving resistance relative to other traits. Disease costs vary widely depending on the prevalence of the disease and on the availability, effectiveness and sustainability of alternative control measures. Costs of treatment and control are relatively simple to estimate for a given situation, but production losses are more difficult. Methods of dealing with this problem are discussed. Breeding for disease resistance usually requires that either selection candidates, or their relatives, are exposed to the pathogen so that resistance levels can be compared. Parasitic diseases generally create no special ethical problems in a breeding program unless natural challenge levels are insufficient to enable discrimination between hosts in their susceptibility. In the longer term, it is desirable that selection criteria for all major diseases be developed that will be informative in healthy animals. Molecular genetic markers offer promise, but simple genetic markers have so far been as elusive as physiological traits to predict resistance in undiseased animals. In the longer term, useful genetic markers will be found and techniques for combining these with phenotypic information need to be developed. Commercial breeding programs for sheep which include resistance to gastrointestinal roundworms are now operating in Australia and New Zealand, and issues related to breeding in the tropics are discussed.

Animals↗
PubMedDate not supplied

Frozen deglycerolyzed blood prevents transfusion-acquired cytomegalovirus infections in neonates.

Frozen deglycerolyzed blood (FDB) was used for routine transfusions to 63 low birth weight newborns (less than or equal to 1500 g) over a 12-month period in an effort to decrease transfusion-acquired cytomegalovirus (CMV) infections. Nine of the 63 infants also received nonfrozen blood products (platelets, liquid blood). Seventy-two percent of the donor blood units were CMV-seropositive. Urine cultures and serum titers for anti-CMV antibody (immunoglobulins G and M) were obtained prior to the initial transfusion and sequentially throughout the study. No infant (0 of 54) who received only FDB acquired CMV, whereas 3 of 9 infants (33%) who received non-frozen blood and FDB acquired CMV, as evidenced by CMV viruria and/or a 4-fold rise in immunoglobulin G anti-CMV antibody titers. These results suggest that transfusions with frozen deglycerolyzed blood decrease the risk in low birth weight infants of acquiring CMV, regardless of the CMV serologic status of the donor.

Antibodies, Viral↗
PubMedDate not supplied

A diabetes control program in a public health care setting.

The Houston Diabetes Control Program is part of an effort by the State of Texas and approximately 30 other programs throughout the United States to ensure that persons with diabetes-related complications receive ongoing state-of-the-art preventive care and treatment. For the past 5 years, this program has served an urban, high-risk patient population with special cultural, ethnic, and economic challenges. The intervention has included the development and implementation of protocols for the prevention and care of diabetes-related complications of the eyes, lower extremities, and cardiovascular system, as well as general management of diabetes and patient and professional education. The program is ongoing in nine community health centers located in low-income neighborhoods of a large metropolitan area. The results thus far indicate an increase in sensitive eye examinations from 8 percent to 26 percent of the patient population, a reduction in incidence of legal blindness from 9.5 to 2.7 per 1,000 during a 4-year period, an increase in foot examinations from 18 percent to 44 percent of the patient population, and 77 percent of hypertensive patients in good control of blood pressure at less than 160 over 95 mmHg (millimeters of mercury). On the average, there have not been significant long-term improvements in weight reduction or blood glucose control. The major challenges for this program are (a) improvement in control of glycemia, hypertension, and cholesterol; (b) more effective diet and physical activity interventions; and (c) more effective education approaches that help patients to understand metabolic and cardiovascular functions. These challenges will require collaboration of health care professionals in constructive and imaginative ways through their unselfish commitment toward common goals.

Aged↗