Copper and zinc balance in exercising horses fed 2 forms of mineral supplements.

Studies comparing the absorption and retention of various forms of trace minerals in horses have yielded mixed results. The objective of this study was to compare Cu and Zn absorption and retention in exercising horses where the mineral was supplemented in the sulfate or organic chelate form. Nine mature horses were used in a modified switchback design experiment consisting of seven 28-d periods. Horses were fed a diet consisting of 50% concentrate and 50% hay that was balanced to meet the energy, protein, Ca, and P requirements for horses performing moderate-intensity exercise. Horses were subjected to a controlled mineral repletion-depletion diet sequence before feeding the experimental diet to standardize mineral status across horses. The experimental diet was designed to provide 90% of the 1989 NRC for Cu and Zn, with supplemental mineral provided in the inorganic sulfate form (CuSO(4) and ZnSO(4)) or the organic chelate form (Cu-Lys and Zn-Met). Feed, fecal, urine, and water samples collected during a total collection during the last 4 d of the experimental diet periods were analyzed to determine apparent absorption and retention of Cu and Zn from the 2 mineral forms. A formulation error caused horses receiving the organic chelate diet to consume about 3 times the amount of Cu and Zn compared with those fed the sulfate-supplemented diet. Copper and Zn intake and fecal excretion were greater (P < 0.05) for horses consuming the organic chelate-supplemented diet. Apparent absorption values for all horses were negative. Apparent Cu absorption and retention as a percentage of intake were greater for horses fed the organic chelate diet (P < 0.05). It is unknown why excretion of Cu and Zn by the horses during the total collection exceeded the mineral intake. Although Cu-Lys seemed to be better absorbed than CuSO(4) and absorption of Zn-Met and ZnSO(4) were not different, these results are tempered by the observation of abnormally high fecal and urinary excretion values for Cu and Zn in the present study.

The roles of acidosis and lactate in the behavioral hypothermia of exhausted lizards.

We conducted this study to determine whether two of the physiological changes associated with non-sustainable exercise, elevated blood lactate levels and decreased arterial pH, contribute to the behavioral hypothermia exhibited by exhausted lizards. Dipsosaurus dorsalis were placed in a thermal gradient and their body temperatures were recorded from 08:00 to 14:00 h. At 14:00 h, animals were subjected to different experimental regimens. In the exercise (E) regimen, animals at 40 degrees C were forced to exercise maximally for 5 min on a treadmill. In the lactate (L) regimen, animals were infused with 11.5 ml kg-1 of 250-500 mmol l-1 sodium lactate. In the osmolarity control (O) regimen, animals were injected with 11.5 ml kg-1 of 500 mmol l-1 NaCl, and in the injection control (I) regimen, animals were injected with 11.5 ml kg-1 of 150 mmol l-1 NaCl. In the hypercapnia (H) regimen, the thermal gradient was flushed with a gas mixture containing 10 % CO2, 21 % O2 and 69 % N2, a treatment that lowers the arterial pH of D. dorsalis to a value comparable with that imposed by exhaustive exercise. A group of control (C) animals was left undisturbed in the thermal gradient for 24 h. Animals in all experimental groups were returned to the thermal gradient, and their cloacal temperatures were monitored until 08:00 h the following morning. The mean cloacal temperature of E animals underwent a significant decrease of 4-7 degrees C, relative to control animals, which persisted for 7 h. The mean cloacal temperatures of animals subjected to 2 h of regimen H also decreased by 3.5-9 degrees C and remained depressed for 12 h following the beginning of the treatment. L, O and I animals did not undergo a significant change in body temperature following treatment, and their mean body temperatures did not differ from those of C animals at any time during the experiment. The results of this study suggest that the metabolic acidosis, but not the elevated blood lactate level, that follows exhausting exercise might play a role in the behavioral hypothermia that follows exhausting exercise in D. dorsalis.

Cord Blood Transplantation Study (COBLT): cord blood bank standard operating procedures.

In 1995, the National Heart Lung and Blood Institute (NHLBI) solicited requests for a proposal (RFP) entitled "Transplant Centers for Clinical Research on Transplantation of Umbilical Cord Stem and Progenitor Cells." Three banks, six transplant centers, and one medical coordinating center (MCC) (Table 1) were funded with the overall goal of banking cord blood units (CBU) using a single manual of operations. Furthermore, the clinical protocols to evaluate the transplant outcome for adult and pediatric recipients of these well-characterized CBU would be analyzed in a uniform fashion. Because of the intense interest of the transplantation community in the policies and procedures for cord blood collection and processing, the principal investigators of the cord blood banks (CBB) and NHLBI elected to submit for publication the rationale and an abridged, but detailed, version of the standard operating procedures (SOP) developed between October 1996 and July 1998 prior to the initiation of the clinical protocols to be performed with these CBU. As the SOP will be refined over time, the complete SOP and subsequent amendments will be published and continually updated on the websites from the MCC-The EMMES Corporation (www.EMMES.com). All forms referred to in this document may be obtained from the EMMES website. It is hoped that the publication of this document will lay down a framework that will not only facilitate the development of other CBB but also help us more rapidly define what constitutes an "acceptable" CBU product.

Postexercise thermoregulatory behavior and recovery from exercise in desert iguanas.

Desert iguanas (Dipsosaurus dorsalis) undergo respiratory recovery more rapidly and incur lower energetic costs when they recover from 40 degrees C burst activity at 20 degrees C than when they recover at 40 degrees C. However, a body temperature of 20 degrees C falls well outside the preferred activity temperature range of this species, and imposes several physiological and behavioral liabilities. To determine if exhausted animals would favor a thermal regimen that allows for rapid and inexpensive respiratory recovery, we exercised lizards to exhaustion and allowed them to recover in a laboratory thermal gradient for 180 min. Recovering animals allowed their body temperatures to cool significantly to a mean temperature of 33.5 degrees C during the first 60 min of recovery, and subsequently rewarmed themselves to an average temperature of 38 degrees C for the remainder of their recovery period. Control animals maintained a constant body temperature of 37.7 degrees C throughout the 180-min recovery period. We then exercised animals to exhaustion at 40 degrees C and allowed them to recover for 180 min under a thermal regimen that mimicked that selected by exhausted animals in the previous experiment. Animals recovering under this thermal regimen returned to rates of O2 consumption, removed exercise-generated blood lactate, and incurred energetic costs that were more similar to data previously collected for animals recovering from exercise at a constant 40 degrees C than to data from animals recovering at 20 degrees C. These results suggested that the energetic benefits associated with recovery at 20 degrees C are not of sufficient biological importance to cause a major shift in thermoregulatory behavior.

Validity and usefulness of medical chart weights in the long-term evaluation of weight loss programs.

The high rate of delayed recidivism seen in behavioral weight loss studies makes follow-up over a number of years essential. Unfortunately, these data are both expensive and difficult to collect. This report examines the validity of body weights routinely recorded in medical charts and their usefulness in the long-term evaluation of weight control programs. Comparison of 123 pairs of chart weights and research clinic weights recorded within 30 days of each other showed a mean difference of .06 lb (.03 kg) and a standard deviation of 2.38 lb (1.08 kg). This measurement error is considerably less than that seen in self-reported weights of obese adults. The accuracy, economy and relative ease of collection make the use of medical chart weights well suited for long-term evaluations of weight loss studies and other research purposes.