Investigation of diabetes mellitus in Burmese cats as an inherited trait: a preliminary study

AIM: To investigate, in a pilot study, a possible genetic component to type 2 diabetes mellitus (T2D) in Burmese cats in New Zealand by analysing pedigree data.

METHODS: Pedigrees were obtained for 305 Burmese cats living in New Zealand; diabetes was diagnosed in 19 of these due to presence of polyuria and polydipsia, persistent concentrations of glucose in plasma >16?mmol/L and glucosuria prior to insulin treatment. Pedigrees were also submitted for 16 cats with no clinical signs of T2D. The remaining 270 cats were unobserved relatives of these individuals. Inbreeding coefficients and heritability were calculated, and a single major locus model segregation analysis was conducted using pedigree analysis software.

RESULTS: Nineteen cats were diagnosed with T2D. Males (n = 14) and females (n = 5) were both affected, suggesting that the gene or genes causing diabetes are autosomal rather than sex-linked. Examination of the pedigree revealed few signs of fully penetrant dominant gene action: diabetes was ostensibly rarely seen in sequential generations and nearly always skipped at least one and often more generations; apparently unaffected offspring of apparently unaffected parents sometimes produced affected progeny. The mean relatedness of the affected animals within the core pedigree (16 diabetic cats) was 0.049, and mean inbreeding 0.033. Based on 100,000 permutations of the trait values, the expected relatedness of a random sample of 16 animals taken from the phenotyped animals would be 0.013 (SD 0.007) (permutation p = 0.0009). The observed inbreeding was also significant (permutation p= 0.02).

Heritability was estimated to be 9 (95% CI = 0–57)% assuming all animals with unknown status were unaffected. The best fitting genetic model was a major gene model with dominant expression with the risk allele frequency at 15% with 60% penetrance.

CONCLUSIONS: In this pilot study the increased inbreeding in the cases, lack of likely sampling bias, the increased frequency of T2D in Burmese, and small number of breed founders are consistent with the involvement of a major locus in diabetes in Burmese cats with a significant risk allele prevalence. However, low case numbers meant this could not be unambiguously confirmed. A genome-wide association study may be useful for investigating the genetic cause of T2D.     

Methodology and validity of assessing kinematics of the thoracolumbar vertebral column in horses on the basis of skin-fixated markers

OBJECTIVE: To determine the validity of using skin-fixated markers to assess kinematics of the thoracolumbar vertebral column in horses. ANIMALS: 5 Dutch Warmblood horses without abnormalities of the vertebral column. PROCEDURE: Kinematics of T6, T10, T13, T17, L1, L3, L5, S3, and both tuber coxae were determined by use of bone-fixated and skin-fixated markers. Three-dimensional coordinate data were collected while horses were walking and trotting on a treadmill. Angular motion patterns were calculated and compared on the basis of 2-dimensional analysis of data from skin-fixated markers and 3-dimensional analysis of data from bone-fixated markers. RESULTS: Flexion-extension of thoracolumbar vertebrae and axial rotation of the sacrum were satisfactorily determined at both the walk and trot, using skin-fixated markers. Data from skin-fixated markers were accurate for determining lateral bending at the walk in the midthoracic and lower lumbar portion of the vertebral column only. However, at the trot, data from skin-fixated markers were valid for determining lateral bending for all thoracolumbar vertebrae. CONCLUSIONS AND CLINICAL RELEVANCE: Caution should be taken when interpreting data obtained by use of skin-fixated markers on lateral bending motions during the walk in horses. For determination of other rotations at the walk and all rotations at the trot, use of skin-fixated markers allows valid calculations of kinematics of the vertebral column. Understanding to what extent movements of skin-fixated markers reflect true vertebral motion is a compulsory step in developing noninvasive methods for diagnosing abnormalities of the vertebral column and related musculature in horses.     

Incidence rate of musculoskeletal injuries and determinants of time to recovery in young Australian Thoroughbred racehorses

Objective To describe the incidence rate of musculoskeletal (MS) injuries and investigate the factors that influence recovery from MS injury in young Thoroughbred horses in Australia. Methods Training and injury data were collected at fortnightly intervals from 14 trainers in New South Wales. Incidence rates were calculated for initial injuries stratified by age‐class and sex. Survival analysis methods were used to investigate the time to recovery after the first MS injury (measured as a start in a race or barrier trial). Results For the 248 racehorses enrolled, there were 428 injuries recorded; 2‐year‐olds were 2.99‐fold more likely than 3‐year‐olds to sustain an MS injury. The cumulative percentage of horses that had recovered within 6 months was 55%. The time to recovery was longest in horses whose fast gallop speed prior to injury was < 890 m/min. Conclusion This study supports the finding that shin soreness is the most common MS injury in young Australian Thoroughbreds. There was an increased rate of MS injury in 2‐year‐olds compared with 3‐year‐olds. However, it was impossible to determine if the increased risk in 2‐year‐olds was related to age, the start of training or a combination of both. The study also found that horses performing at higher exercise speeds prior to injury were more likely to recover. There was a significant effect of trainer, suggesting that other factors related to trainer may influence the time to the recovery. Additional research is required to understand the determinants of time to recovery.     

Concepts of disease, medical research and the challenges to the schools of the healing professions

The study of disease is a significant part of the pattern of funding for medical research in North America and elsewhere. Also, the existence of disease and its importance in all branches of the healing professions is the major justification for separate professional schools of medicine. These considerations should encourage a vigorous exploration and development of concepts of disease as an important part of any medical education. Based on much of the current research activities, concepts of disease, especially chronic disease, seem largely outdated and not intimately reflecting the realization that the development of disease is often a physiological response to perturbations in the internal or external environment and not abnormal or pathological in the etymological sense. The importance of viewing cancer and other chronic diseases from this physiological point of view and not from the point of view of end-stage disease is emphasized by the use of one example, the development of cancer with chemicals. The challenge to the healing professions to develop more modern programs for educating the prospective research worker for the study of disease is discussed briefly.     

The recent decline of unionization in the United States

The dramatic decline in unionization during the last decade is investigated with the use of survey data from 1977 and 1984. First, it is found that only a small fraction of the decline in unionization can be accounted for by shifts in labor force structure. Second, there has been a substantial drop in demand for union representation among nonunion workers that can be accounted for by an increase in the job satisfaction of nonunion workers and a decrease in nonunion workers' reports that unions improve wages and working conditions. Finally, there has been a substantial increase in employer resistance to unionization that is likely to have made it more difficult for unions to organize even those workers who desire union representation. Increased foreign and increased nonunion domestic competition (particularly in deregulated industries) may be key underlying causes of these changes.     

Computer networking for scientists

Scientific research has always relied on communication for gathering and providing access to data; for exchanging information; for holding discussions, meetings, and seminars; for collaborating with widely dispersed researchers; and for disseminating results. The pace and complexity of modern research, especially collaborations of researchers in different institutions, has dramatically increased scientists' communications needs. Scientists now need immediate access to data and information, to colleagues and collaborators, and to advanced computing and information services. Furthermore, to be really useful, communication facilities must be integrated with the scientist's normal day-to-day working environment. Scientists depend on computing and communications tools and are handicapped without them.     

Prevalence and molecular characterization of Giardia duodenalis and Cryptosporidium spp. in dairy cattle in Ontario, Canada

Giardia duodenalis and Cryptosporidium spp. are intestinal protozoan parasites that infect a wide range of host species, including humans. Molecular characterization of these parasites has demonstrated that a number of genotypes and species are common to both humans and animals, and that zoonotic transmission may occur. Numerous studies have reported a high prevalence of G. duodenalis and Cryptosporidium spp. in cattle, particularly calves, and these animals are frequently associated with zoonotic transmission. In the present study, a total of 143 faecal samples from adults, heifers and calves were collected from two dairy cattle farms in eastern Ontario, Canada. The prevalence and molecular characteristics of G. duodenalis and Cryptosporidium spp. in these animals were determined in order to investigate the potential for transmission between cattle and humans in this region. Following DNA extractions from faecal samples, nested-PCR protocols were used to amplify fragments of the 16S rRNA gene and the heat-shock protein 70 (HSP-70) gene for determining the prevalence of G. duodenalis and Cryptosporidium spp. infections, respectively. Genotypes of G. duodenalis, and species of Cryptosporidium, were determined by means of DNA sequencing of amplicons, and subsequent sequence alignment. Cattle on both farms showed a high prevalence of G. duodenalis (42.0%) and Cryptosporidium spp. (27.3%). G. duodenalis infections were more prevalent in calves and heifers than in adults, and Cryptosporidium spp. infections were only observed in calves and heifers. The zoonotic genotype, G. duodenalis Assemblage B was isolated from 24.5% of the cattle tested, while G. duodenalis Assemblage E was found in 17.5% of the cattle tested. The overall prevalence of the zoonotic species Cryptosporidium parvum in the animals tested was found to be 21.7%, while only 1.4% were infected with C. bovis. These findings suggest that there is a potential risk of zoonotic and/or zooanthroponotic transmission of G. duodenalis and C. parvum infections between cattle and humans in eastern Ontario, likely by means of contaminated water or food, or through direct faecal-oral transmission in the case of farmers and veterinary staff.