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At least 199 records · Page 11Linked to original sources
PubMed2005

Genetic and environmental parameters for racing time at different distances in Brazilian Thoroughbreds.

The aim of the present study was to investigate genetic parameters for racing time in Thoroughbred horses racing at distances between 1000 and 1600 m subdivided into 100-m intervals. The data provided by TURFETOTAL Ltda comprised races that occurred in the Gávea and Cidade Jardim race tracks over a period of 11 years (1992-2002) and consisted of 32,145 races and 238,890 time records. The variance components necessary to obtain the heritability and repeatability estimates of the traits studied were estimated with the MTDFREML program, and animal age at race (3 years old or younger, 4, 5 and older than 5 years), sex (male and female), number of races (1-32,145), and postposition at start (1-11) as fixed effects, and animal and permanent environmental random effects were included in a one-trait animal model. Males were significantly superior to females at all distances. Excluding the 1100 m distance, animals 4 years of age were significantly faster than the mean of the other ages for all distances analysed. Horses older than 5 years showed a significantly lower performance than the mean of the other ages for all distances analysed, except for the 1100 m. Postpositions one and two did not differ significantly from one another for any of the distances analysed. These two inner positions both together varied from the other positions depending on race length. The components of additive genetic and permanent environmental variance varied in a similar way, tending to decrease with increasing racing distance, and the other temporary environmental variance almost doubled from 1000 to 1600 m. As was the case for the additive genetic and environmental variances, heritability and repeatability estimates tended to decrease with increasing distance, indicating that selection based on racing time will be less successful when the racing distance increases.

Age Factors↗
PubMed2002

Voluntary food intake by elite female cyclists during training and racing: influence of daily energy expenditure and body composition.

We estimated self-reported energy intake (EI) and cycling energy expenditure (CEE) during racing and training over 26 days (9 days recovery [REC], 9 days training [TRN], and 8 days racing [RACE], which included a 5-day stage race) for 8 members of the Australian National Training Squad [mean SD; 25.1 4.0 years, 59.2 4.4 kg, 3.74 0.24 L min-1 VO 2 peak, 13.6 4.5 % Body fat (% B fat)]. After 70 days of training and racing, average body mass increased by 1.1 kg (95%CI 0.5 to 1.7 kg; p <.01) and average % B fat decreased by 0.9% (95%CI 1.7 to 0.1%; p <.05). These minor changes, however, were not considered clinically significant. CEE was different between RACE, TRN, and REC (2.15 0.18 vs. 1.73 0.25 vs. 0.72 0.15 MJ d-1, p <.05). Reported EI for RACE and TRN were higher than REC (14.87 3.03, 13.70 4.04 vs. 11.98 3.57 MJ d-1, p <.05). Reported intake of carbohydrate for RACE and TRN were also higher than REC (588 122, 536 130 vs. 448 138 g d-1, p <.05). Reported intake of fat (59 21 68 21 g d-1) was similar during RACE, TRN, and REC, whereas protein intake tended to be higher during TRN (158 49 g d-1) compared to RACE and REC (136 33; 130 33 g d-1). There was a relationship between average CEE and average EI over the 26 days (r = 0.77, p <.05), but correlations between CEE and EI for each of the women varied (r = 0.02 to 0.67). There was a strong trend for an inverse relationship between average EI and % Bf at (r = -.68, p =.06, n = 8). In this study, increases in reported EI during heavy training and racing were the result of an increase in carbohydrate intake. Most but not all cyclists modulated EI based on CEE. Research is required to determine whether physiological or psychological factors are primarily responsible for the observed relationship between CEE and EI and also the inverse correlation between % B fat and EI.

Adipose Tissue↗
PubMed1997

Chromosomal rearrangements in rock wallabies, Petrogale (Marsupialia: Macropodidae). IX. Further G-banding studies of the Petrogale lateralis complex: P. lateralis pearsoni, the west Kimberley race, and a population heterozygous for a centric fusion.

G-banded metaphase preparations from cultured fibroblasts were used to examine the karyotypes of Petrogale lateralis pearsoni and the West Kimberley (WK) race of P. lateralis. Petrogale lateralis pearsoni was found to retain the ancestral 2n = 22 Petrogale karyotype, while the WK race (2n = 20) was found to be characterized by a 9-10 centric fusion. This taxon had been reported to have an 8-10 fusion. Karyotypic analysis was also used to identify Petrogale populations in the Erskine Range, Western Australia (W.A.) as the WK race and in the Walter James Range, W.A. as the MacDonnell Ranges (MDR) race of P. lateralis. These findings represent significant range extensions for both taxa. A third P. lateralis population, from the Townsend Ridges, W.A., could not be definitively identified to subspecies or race and appears intermediate between the WK and MDR races. Four animals were examined from this population and all possessed an identical 2n = 21 karyotype characterized by homozygosity for a derived acrocentric chromosome 3 (3a) and heterozygosity for a 9-10 fusion. Rearrangement 3a is typical of the MDR race, while the 9-10 fusion is characteristic of the WK race. The polymorphic Townsend Ridges population could result from the de novo creation of a 9-10 fusion (similar in morphology to the 9-10 fusion of the WK race) or it may represent evidence of hybridization between the MDR race and either the WK race or a currently unknown taxon. Additional data will be required to distinguish between these hypotheses.

Animals↗
PubMed2002

Physiology of wheelchair racing in athletes with spinal cord injury.

Wheelchair racing is one of the most popular sporting activities of individuals with spinal cord injury. Athletes with this impairment have unique changes in metabolic, cardiorespiratory, neuromuscular and thermoregulatory systems, which reduce their overall physiological capacity compared with able-bodied individuals or individuals with other types of impairments. This review on spinal cord injury: presents the International Stoke Mandeville Games Federation classification of wheelchair athletes; describes methods commonly used to characterise anaerobic and aerobic fitness; presents the findings of physiological studies that have evaluated wheelchair racing performance; identifies the risks associated with temperature regulation when competing in wheelchair races; and discusses special conditions that can influence wheelchair racing performance. Currently there is limited research that has examined the relationship between sprint or distance wheelchair racing performance and the anaerobic and aerobic components of physical fitness. Although the descriptive evidence indicates that the profiles of these athletes reflect their training and participation in these specific events, the association between their physiological profiles and real or simulated racing performance is unclear. The generally accepted concept that high values of aerobic and anaerobic power are strongly correlated with endurance and sprint racing performance, respectively, are not necessarily true in this population. Athletes with spinal cord injury have an impaired thermoregulatory capacity, because the compromised autonomic and somatic nervous system functions disrupt control of skin blood flow and sweating below the level of the lesion. As a result, they may be more susceptible to hyperthermia during distance wheelchair racing performance. Wheelchair athletes should follow recommendations advocated for able-bodied individuals to minimise their risks of heat stress during competition. Many athletes with quadriplegia voluntarily induce autonomic dysreflexia (commonly known as boosting) during distance racing events to improve performance. Experimental evidence indicates that boosting can improve performance time by 10% in elite wheelchair marathon racers during simulated racing, as a result of increased oxygen utilisation in the boosted state. However, since boosting can be dangerous to health, the International Paralympic Committee has banned athletes from voluntarily inducing it during competition. The use of anti-gravity suits to increase lower-body positive pressure can increase the peak oxygen uptake, cardiac output and stroke volume. However, the use of abdominal binders does not influence these physiological responses. An effect of either of these techniques on wheelchair racing performance has not been demonstrated.

Body Temperature Regulation↗
PubMed2006

Risk of fatality and causes of death of Thoroughbred horses associated with racing in Victoria, Australia: 1989-2004.

REASONS FOR PERFORMING STUDY: Determining the risk of fatality of Thoroughbred horses while racing is essential to assess the impact of intervention measures designed to minimise such fatalities. OBJECTIVES: To measure the risk of racehorse fatality in jump and flat starts on racecourses in Victoria, Australia, over a 15 year period and to determine proportional mortality rates for specific causes of death. METHODS: All fatalities of Thoroughbred horses that occurred during or within 24 h of a race were identified from a database. The risk of a start resulting in a racehorse fatality in all races and within flat and jump races, proportional mortality rates, population attributable risk, population attributable fraction and risk ratios were calculated along with 95% confidence intervals. Poisson regression was also performed to estimate risk ratios. RESULTS: There were 514 fatalities over the 15 year period; 316 in flat races and 198 in jump races. The risk of fatality was 0.44 per 1000 flat starts and 8.3 per 1000 jump starts (18.9 x greater). The risk of fatality on city tracks was 1.1 per 1000 starts whereas on country tracks it was 0.57 per 1000 starts. Of the 316 fatalities in flat races, 73.4% were due to limb injury, 2.5% to cranial or vertebral injury and 19.0% were sudden deaths. Of the 198 fatalities in jump races, 68.7% were due to limb injury, 16.2% to cranial or vertebral injury and 3.5% were sudden deaths. The risk of fatality in flat starts increased between 1989 and 2004 but the risk in jump starts remained unchanged over the 15 year period. CONCLUSIONS: The risk of fatality in flat starts was lower in Victoria than North America and the UK but the risk in jump starts was greater. Catastrophic limb injury was the major reason for racehorse fatality in Victoria but there was a larger percentage of sudden deaths than has been reported overseas. The risk of fatality in jump starts remained constant over the study period despite jump racing reviews that recommended changes to hurdle and steeple races to improve safety. POTENTIAL RELEVANCE: This study provides important benchmarks for the racing industry to monitor racetrack fatalities and evaluate intervention strategies.

Animals↗
PubMed2006

Racing performance after arthroscopic removal of apical sesamoid fracture fragments in Thoroughbred horses age > or = 2 years: 84 cases (1989-2002).

REASONS FOR PERFORMING STUDY: Studies have shown that surgical removal of apical fracture fragments in Standardbred racehorses carries the best prognosis for return to racing performance, but there are no reports involving mature Thoroughbred (TB) racehorses. OBJECTIVES: To describe the incidence of apical proximal sesamoid fractures in TB racehorses and determine probability and quality of racing performance after arthroscopic removal of such fractures in TB racehorses age > or = 2 years. METHODS: Medical records and pre- and post operative race records of TB racehorses age > or = 2 years that underwent arthroscopic surgery for removal of apical proximal sesamoid fracture fragments were reviewed. RESULTS: Sixty-four percent of fractures occurred in the hindlimbs and 36% in the forelimbs. Horses with forelimb fractures had a reduced probability of return to racing (67%) compared to those with hindlimb fractures (83%), but the majority (77%) of treated horses recovered to return to race post operatively. Horses with medial forelimb fractures raced at only a 47% rate; those with suspensory desmitis at 63%. Unlike Standardbreds, there was no difference in probability of racing post operatively between horses that had, and had not, raced preoperatively. CONCLUSIONS: Data show that arthroscopic removal of apical proximal sesamoid fracture fragments is successful at restoring ability to race in skeletally mature TB horses without evidence of severe suspensory ligament damage. Prognosis for return to racing is excellent (83%) in horses with hindlimb fractures and good (67%) in those with forelimb fractures. Medial fractures of the forelimb have the worst prognosis. POTENTIAL RELEVANCE: The determination of prognosis for differing sites in TB racehorses should increase knowledge of apical proximal sesamoid bone fractures and improve communication from veterinarian to owner, and trainer, on the potential for arthroscopic restoration of the ability to race.

Age Factors↗
PubMed2001

[Genetics and the origin of human races].

In the last decades, the concept of human races was considered scientifically unfounded as it was not confirmed by genetic evidence. None of the racial classifications, which strongly differ in the number of races and their composition, reflects actual genetic similarity and genealogy of human populations inferred from variability of classical markers and DNA regions. Moreover, intercontinental ("interracial") variability was shown to be far lower than that within populations: the former constitutes 7 to 10% and the latter, about 85% of the total genetic variation. It is believed that the low level of differentiation of regional population groups contradicts their race status and suggests a recent origin of humans from one ancestral population. The results of studies of various genetic systems are in agreement with last conclusion rejecting the hypothesis of regional continuity. According to this hypothesis, the populations of continents regarded as large races have developed during long evolution from local types of archaic humans, in particular, Neanderthals. Phenotypic similarity of different, sometimes unrelated, populations united into one "race" is explained by strong selection since race-diagnostic traits characterize body surface and thus are directly subjected to the influence of environmental (primarily climatic) factors. It has been recently established that variability of the most important of these traits, body and hair pigmentation, is largely controlled by one locus (MC1R), which accounts for its high evolutionary lability. Other traits used for race identification are also likely to be labile and controlled by major genes. However, the fact that the currently existing race classifications are groundless does not mean that such classifications are impossible in principle. Commonly used argumentation (races do not exist because populations are not genetically separated) does not hold water. A polytypic species is characterized by genetic continuity of allopatric populations rather than the presence of narrow genetic boundaries between them. Borderlines between races are usually conventional and arbitrary. As to intergroup variation in humans, it is indeed low but comparable with that in some other species. There are no obstacles to the development of genetic systematics of human races.

Biological Evolution↗
PubMed2003

Identification of physiological races of Blumeria graminis f. sp. tritici and evaluation of powdery mildew resistance in wheat cultivars in Sistan province, Iran.

Powdery mildew of wheat caused by Blumeria graminis f. sp. tritici (Bgt) is one of the most important fungal diseases in Iran. During the years 1998-2001, wheat fields in Sistan province were surveyed and powdery mildew infected samples were collected from various areas and transferred to the laboratory. In the greenhouse, fungal spores were purified and inoculated onto susceptible wheat cultivars using single pustule and single spore procedures. Selected pure isolates were inoculated onto the first leaves of eight differential wheat varieties for identifying physiological races. The results showed the existence of Bgt races 5, 11, 14, 19, 21, 24, 27, 28, 31, 32, 44, 50, 53, 58, 66, 73 and 84 in Sistan. These races were new to Sistan province and Iran as a whole. Among 17 races studied, races 11, 53 and 73 were important dominant races thus constituting 40% of total population. Race 53 constituted 16% of all isolates and was the dominant race in the area with 62.5% pathogenicity. Therefore, this race was introduced as the most virulent race during the period of this study. This study showed that Bgt isolates were compatible with host plant genes pm8, pm3 and pm3b but incompatible with gene pm4b. Powdery mildew resistance was evaluated using race 11 on 70 wheat cultivars during seedling stage as well as adult plant under both greenhouse and field conditions between 1999 and 2001. Among wheat lines tested for resistance against powdery mildew, cultivar Hirmand resembled the differential line Weihenst M1 in that both may possess gene pm4b and showed no symptoms under the greenhouse and field conditions. Cultivar Chamran was found to be highly resistant whereas Sorkhtokhm was susceptible. Other cutivars showed partial and gradual resistance against the powdery mildew disease.

Ascomycota↗
PubMed1986

Factors affecting prerace dehydration and performance of racing greyhounds.

Several factors, including age, sex, race number, post position, and race class, were evaluated for relationships to prerace percentage body weight loss and performance in all Greyhounds racing during August 1983 in Oregon. The incidence of percentage body weight loss greater than or equal to 2.5% was low (5%). Race number had a direct effect on weight loss; the later the dogs raced, the more weight loss they experienced. Female dogs were 3 times more likely to lose greater than 2.4% of body weight than males. All dogs experiencing greater than 2.4% body weight loss were 2 times more likely to finish in the first 3 places when racing in the first 5 races overall. In addition, males losing greater than 2.4% of body weight performed better than females when racing together in the final 6 races. Males appeared to be better performers than females, as they were twice as likely to be in class A races. However, once in the race, males and females performed equally.

Age Factors↗
PubMed1985

Effects of furosemide on the racing times of horses with exercise-induced pulmonary hemorrhage.

In 3 groups of horses with exercise-induced pulmonary hemorrhage (EIPH), comparisons of racing times and finishing positions were made between the 5 races before the horses were given furosemide and 5 races after furosemide administration. The horses were grouped according to 3 methods used to diagnose EIPH: group 1, observation of hemorrhage at the nostrils within 1 hour after a workout or race; group 2, observation of pulmonary hemorrhage only by endoscopic examination after a race or workout; and group 3, observation of hemorrhage at the nostrils during a race or immediately after a race. Group 4 horses were randomly selected horses running during the study period and were not given furosemide. The statistical method was analysis of covariance and the dependent variable was horses' time per distance. The study compared the 4 groups of horses, using the estimated value of the horses (less than or equal to +10,000 or greater than +10,000), and the horses' interaction in races 1 through 5 before and races 6 through 10 after furosemide treatment. The horses' times were adjusted by the relevant covariates, distance, track variant, and winning time per distance. Significant changes in horses' time per distance were not noticed when comparing values from races 1 through 5 with those in races 6 through 10 in group 1 horses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Postoperative racing performance in standardbreds and thoroughbreds with osteochondrosis of the tarsocrural joint: 109 cases (1984-1990).

Medical records for 64 Thoroughbred and 45 Standardbred horses with osteochondrosis dissecans (OCD) of the tarsocrural joint that were treated by means of arthroscopic removal of the fragments before 2 years of age and before beginning racing were reviewed. Lesion site was recorded for all horses. The other foals from the dams of these surgically treated horses (siblings) were identified from mare progeny records. Racing data, including number of starts and money won during the 2- and 3-year-old racing years were obtained from the Jockey Club and the United States Trotting Association for affected horses and their siblings. Statistical analysis was performed to test the hypothesis that there was no difference between the racing performance of horses with OCD of the tarsocrural joint that were surgically treated by means of arthroscopic removal of the fragments prior to racing and that of their siblings. One hundred and seventy-four lesions were recorded in 109 horses. The distribution of lesions was similar to that previously reported. For the Standardbreds, 22% of those that had surgery raced as 2 year olds and 43% raced as 3 year olds, compared with 42 and 50% of the siblings that raced as 2 year olds and 3 year olds, respectively. For the Thoroughbreds, 43% of those that had surgery raced as 2 year olds and 78% raced as 3 year olds, compared with 48% and 73% of the siblings that raced as 2 year olds and 3 year olds, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Prevalence of, and factors associated with, musculoskeletal racing injuries of thoroughbreds.

All horses diagnosed by a commission veterinarian of the Kentucky Racing Commission as having sustained a musculoskeletal injury, defined as an obvious change in soundness immediately before, during, or after a race held between Jan 1, 1992 and May 31, 1993 were included in a study to determine the prevalence of and factors associated with racing injuries involving the musculoskeletal system of horses competing at 4 Thoroughbred racetracks in Kentucky. During the 17-month study, there were 35,484 racing starts among 7,649 horses in 3,824 official Kentucky Racing Commission races. During this period, 132 musculoskeletal racing injuries were diagnosed among 117 horses. Twenty-eight injured horses were male, 46 were geldings, and 43 were female. The prevalence of horses with racing injuries per racing start was 0.33% (117/35,484). The injuries of 51 horses were classified as catastrophic, and 66 as noncatastrophic. The prevalence of horses with catastrophic injuries per racing start was 0.14% (51/35,484). The proportion of horses with injuries of the left forelimb, sesamoid, and third metacarpal bone in the catastrophic group was significantly (P < or = 0.05) greater than those of horses in the noncatastrophic group. The proportion of horses with injuries of the superficial digital flexor tendon among those in the catastrophic group was significantly less than that of horses in the noncatastrophic group. The distance of the race was significantly shorter and the number of turns less among horses with catastrophic injuries than among horses with noncatastrophic injuries.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2004

Chimeric analysis of the small GTPase RacE in cytokinesis signaling in Dictyostelium discoideum.

RacE is a small GTPase required for cytokinesis in Dictyostelium discoideum. To investigate RacE's potential binding and signaling interfaces that allow its function in cytokinesis, 10 different chimeras were created between RacE and the closely related small GTPase, RacC. RacE/RacC chimeras, containing various combinations of four RacE regions, E I-IV: E-I (aa 1-67), E-II (aa 68-124), E-III (aa 125-184), and E-IV (aa 185-223), were tested for their ability to rescue the multinucleated, cytokinesis-defective phenotype of RacE null cells grown in suspension. Regions E-II and E-IV were essential but not sufficient for the rescue of RacE null cells. These two regions, in combination with either region E-1 or E-III, resulted in rescue. Results presented here suggest that region E-II contains a crucial, yet incomplete, binding site. Regions E-I or E-III separately provide additional, necessary elements for RacE's function. The extended E tail of RacE (E-IV) may act as a 'sensor' of the bound nucleotide state of RacE and facilitate GDP to GTP exchange (possibly through interactions with a GEF molecule), thereby resulting in activation of RacE. This study provides new evidence for small GTPases engaging several distinct protein interfaces to mediate signaling in various cellular processes.

Amino Acid Sequence↗
PubMed1994

Emergency medical care for open wheel racing events at Indianapolis Raceway Park.

STUDY OBJECTIVES: To analyze open-wheel racing accidents at Indianapolis Raceway Park during six seasons (1988 through 1993) and describe factors that improve driver safety. DESIGN: Retrospective analysis. SETTING: Indianapolis Raceway Park, a three-track racing facility that includes a 0.686-mile banked, paved, and lighted oval track. PARTICIPANTS: Race drivers in three United States Auto Club racing divisions (Midget, Sprint, and Silver Crown). MEASUREMENTS AND MAIN RESULTS: During 61 open-wheel racing events, 57 drivers were evaluated at Indianapolis Raceway Park after crashes. Eighteen were transferred to Methodist Hospital of Indiana; four drivers required admission two to the ICU. There were no driver deaths. CONCLUSION: Although open-wheel racing is one of the most common forms of motorcar racing, there have been no previously published studies regarding injury patterns or medical care at these events. This study reviewed race driver injuries during six seasons of open-wheel racing at the Indianapolis Raceway Park. During 61 open-wheel racing events, no drivers were killed, but two required intensive care hospitalization.

Accidents↗
PubMed1998

A role for Dictyostelium racE in cortical tension and cleavage furrow progression.

The small GTPase racE is essential for cytokinesis in Dictyostelium. We found that this requirement is restricted to cells grown in suspension. When attached to a substrate, racE null cells form an actomyosin contractile ring and complete cytokinesis normally. Nonetheless, racE null cells fail completely in cytokinesis when in suspension. To understand this conditional requirement for racE, we developed a method to observe cytokinesis in suspension. Using this approach, we found that racE null cells attempt cytokinesis in suspension by forming a contractile ring and cleavage furrow. However, the cells form multiple blebs and fail in cytokinesis by regression of the cleavage furrow. We believe this phenotype is caused by the extremely low level of cortical tension found in racE null cells compared to wild-type cells. The reduced cortical tension of racE null cells is not caused by a decrease in their content of F-actin. Instead, mitotic racE null cells contain abnormal F-actin aggregates. These results suggest that racE is essential for the organization of the cortical cytoskeleton to maintain proper cortical integrity. This function of racE is independent of attachment to a substrate, but can be bypassed by other signaling pathways induced by adhesion to a substrate.

Actins↗
PubMed2004

Race is not associated with nevirapine pharmacokinetics.

The effect of race on the pharmacokinetics of nevirapine was investigated in a nonselected population. Included patients were ambulatory HIV-1-infected patients from the outpatient clinics of the Academic Medical Center and the Slotervaart Hospital, Amsterdam, The Netherlands. All patients were using nevirapine as part of their antiretroviral regimen and had at least one plasma concentration available for analysis. From the included patients, gender, age, race, hepatitis C status, baseline ASAT value, and body weight were obtained. The nonlinear mixed-effect modeling program (NONMEM) version V 1.1 was used for all analyses. Population pharmacokinetic parameters [clearance (CL/F), volume of distribution (V/F), absorption rate constant (ka)] and interindividual (IIV) and interoccasion variability (IOV) were estimated. The influence of race on the CL/F of nevirapine was tested as Negroid race versus the other races, Asian race versus the other races, and the Negroid and the Asian races as separate variables versus the Caucasian race. A database of 1732 nevirapine plasma concentrations of 383 HIV-1-infected individuals collected during 1186 outpatient clinic visits was available for this analysis. The conclusion of this study is that race is not associated with the pharmacokinetics of nevirapine, and thus requires no dose adaptations.

Adult↗
PubMed1995

Donor race does not affect cadaver kidney transplant survival--a single center experience.

Black kidney transplant recipients have worse graft survival than white recipients. Speculation regarding etiology has focused on differences in human lymphocyte antigens (HLA). Some suggest that improvements in graft survival would be obtained if donor and recipient race were matched. We reviewed 236 cadaver transplants performed over 9 years at a single center using an HLA-match-driven allocation system and a uniform immunosuppressive protocol to determine the impact of donor race on graft survival. A multivariate analysis of graft survival using patient race, sex, age, transplant number, current and maximum plasma renin activity, donor race, cold ischemia time and HLA mismatch, the need for dialysis, and the presence of rejection as independent variables. Sixty percent of recipients were black, and 82% were primary transplants; 28 kidneys (12%) were from black donors. The 112 patients with the same race donor had identical 5-year graft survival as the 124 who had a different race donor (40%; P = 0.1726). The 5-year survival of the 88 white recipients of white donor organs was better than that of the 120 black recipients of white donor organs (54% vs. 42%, respectively; P = 0.0398). Black recipients (t1/2 = 37 months) did worse than white recipients (t1/2 = 60 months) regardless of organ source (P = 0.023). In the multivariate analysis, neither donor nor recipient race were an independent variable in predicting graft survival. Rejection (RR = 2.9) and the need for dialysis on the transplant admission (RR = 4.1) were the only factors that predicted poor survival. Black recipients had more rejection (P = 0.04) but not more need for dialysis posttransplant regardless of donor race. Donor race did not affect graft survival in this series. The effect of recipient race on graft survival was due to an increased incidence of rejection episodes in black recipients, which was independent of HLA mismatch. These data suggest that improvements in immunosuppression, not changes in allocation, are needed to improve graft survival.

Adult↗
PubMed2002

Effect of an endurance race on muscle amino acids, pro- and macroglycogen and triglycerides.

Glycogenolysis and lipolysis are essential for energy production in muscle during prolonged exercise but less is known about the role of amino acid metabolism. The aim was to study the effect of an endurance race on pro- and macroglycogen, triglycerides and amino acid concentrations in muscle and on selected blood parameters, especially the amino acid response in the blood during the recovery phase. Seven endurance-trained horses completed a race covering 100-120 km. Blood samples were collected one day before the race, after the finish and 1 and 8 days after the race. Needle biopsy specimens from the gluteus medius muscle were taken on completion of the race and 8 days postrace. The pro- and macroglycogen concentrations were lower and most amino acid concentrations were higher in the muscle after the finish of the race, than 8 days postrace, whereas the triglyceride concentrations did not differ. The concentrations of several amino acids in serum were higher during the recovery phase than before the race. The observed changes suggest that an endurance race influences amino acid metabolism and a net protein degradation may occur that persists during the recovery phase. Furthermore, the results suggest that macroglycogen is utilised to a greater extent than proglycogen during an endurance race. Further research is needed concerning amino acid metabolism during an endurance race as it seems to play an important role both for performance and recovery after exercise.

Amino Acids↗