Validation of a chemiluminescent enzyme immunometric assay for plasma adrenocorticotropic hormone in the dog

BACKGROUND

The concentration of canine adrenocorticotropic hormone (ACTH) is usually determined by radioimmunoassay. However, chemiluminescent assay techniques have many advantages for clinical endocrine testing.

OBJECTIVES

The objectives of this study were to validate a commercially available chemiluminescent assay for determination of canine ACTH concentration and to determine whether protease inhibitors are appropriate for use in the chemiluminescent assay system.

METHODS

Biological specificity was evaluated by treatment of 3 dogs with ovine corticotropin-releasing hormone (CRH) followed by serial measurements of ACTH and by comparison with a previously validated immunoradiometric assay. All samples were collected both in the presence and absence of aprotinin, a protease inhibitor. The assay was further evaluated by measurement of intra-assay precision, interassay precision, and recovery after dilution.

RESULTS

Baseline ACTH concentrations ranged from 5.6 to 15.3 pg/mL, and maximum ACTH concentrations of 158 to 1240 pg/mL were observed 30-60 minutes after CRH administration. Plasma samples collected with aprotinin had significantly lower ACTH concentrations than did samples collected without aprotinin. The intra-assay coefficients of variance (CVs) ranged from 4.1 to 8.2%, and interassay CVs ranged from 4.6. to 14.8%. Recovery after dilution with canine plasma ranged from 93.4 to 103.0% of predicted concentration; however, inadequate recovery was observed with other diluents. There was a high correlation with the immunoradiometric assay (r =.925) but a significant negative bias (-32.9, 95% confidence interval -50.8 to -14.9).

CONCLUSIONS

This chemiluminescent assay is a valid technique for measurement of ACTH in canine plasma. ACTH concentration measured by chemiluminescence is lower than that measured by immunoradiometry. Aprotinin decreases the measured concentration of ACTH, and this effect should be taken into account when interpreting results. Diluents supplied with the kit should not be used for dilution of canine samples.

Extremely limited mitochondrial DNA variability among the Aché Natives of Paraguay

BACKGROUND

The Aché Natives are an especially interesting group of people, due to their distinctive morphological aspect and the fact that only in the last three decades have they established more permanent contact with outside populations. The objectives of the present study were: (a) to verify their distinctiveness in relation to mitochondrial DNA (mtDNA) variability; (b) to ascertain whether the pattern observed was congruent with other genetic studies performed among them; and (c) to establish historical inferences that would explain the eventual similarities or differences.

SUBJECTS AND METHODS

Sample collection was made at two localities in eastern Paraguay. DNA from 64 maternally unrelated subjects were tested in relation to the mtDNA hypervariable segment 1 (HVS-1) by automatic sequencing.

RESULTS

Fifty-six individuals presented exactly the same haplogroup B founder haplotype; another differed from it by a single transition polymorphism at site 16362, while six other subjects showed an identical haplogroup A founding haplotype. An A/G heteroplasmy at the 16269 site was seen in one haplogroup B individual, probably due to a somatic mutation.

CONCLUSIONS

The Aché present distinctive differences and reduced mtDNA HVS-1 variability compared to other South American Natives. Similar differences were observed for other genetic systems. At present it is not clear whether their peculiarities already existed in their founding populations or whether they were secondarily acquired due to a long period of isolation in the humid, subtropical forest.

HLA class II diversity in seven Amerindian populations. Clues about the origins of the Ache

The study of the HLA variability of Native American populations revealed several alleles specific to one or more of the Latin American indigenous populations. The analysis of Amerindian groups distributed all over the continent might inform about the area of origin and the dispersal of these alleles and shed light on the evolution of this remarkable polymorphism. Moreover, HLA alleles and haplotypes are excellent markers to understand the genetic relationships between populations. For these reasons, we characterized the HLA class II polymorphism in seven South American Amerindian populations and compared the results with those previously reported for other Amerindian groups. The Guarani-Kaiowá (n = 160) and Guarani-Nandeva (n = 87) were from the Brazilian state of Mato Grosso do Sul, the Guarani-M'byá (n = 93) and Kaingang (n = 235) from Paraná state, the Aché (n = 89) from eastern Paraguay, the Quechua (n = 44) from Andean Peru. From Amazonia, a heterogeneous group was analyzed (n = 45). The most frequent alleles and haplotypes are common also in other Amerindian populations. Each HLA-DRB1 allele was typically found in combination with just one DQA1-DQB1 haplotype, most likely as a result of some form of random genetic drift and reduced gene flow from non-Amerindians. The frequency distribution differed significantly among all populations, although differences were less pronounced between the Guarani subgroups. Marker alleles allowed an estimate of European and sub-Saharan African gene flow into these populations: Quechua 23%, Guarani-Nandeva 14%, Kaingang 7%, Guarani-M'byá 4%, Guarani-Kaiowá, Amazonia, and Aché 0%. Interestingly, the DRB1*1413 allele, previously found only among the Guarani-M'byá (frequency 15%), appeared in the Aché (8%). The relationship of the Aché to other Amerindian populations is unclear, and this finding reveals a link with the Guarani. On the basis of genetic distance and the HLA allele/haplotype set, we propose that the Aché are differentiated Tupi-Guarani group, most closely related to the Guarani-M'byá.

Methylenetetrahydrofolate reductase (MTHFR) allele frequencies in Amerindians

Neural tube defects (NTDs) have been associated with abnormalities of folate metabolism. Methylenetetrahydrofolate reductase (MTHFR) is the regulatory enzyme for the conversion of homocysteine to methionine. The C677T mutation in the MTHFR gene affects folate distribution, and homozygosity for the T allele may be associated with an increased risk of NTDs. A second mutation, an A1298C transversion in this same gene, is also associated with an increased risk for NTDs but only in conjunction with the 677T allele. A low incidence of NTDs has been observed in high-altitude populations; however, these studies did not provide information about the allele distribution of genes involved in folate metabolism. This investigation compares allele frequencies of the C677T and A1298C polymorphisms between Quechua people living at 3200-4200 m in the Peruvian Central Andes and an Aché group living at low altitude. Allele frequencies at both loci were not significantly different between the two populations. The absence of the 677T/677T genotypes and of the 677T/1298C arrangement in both groups may indicate a genetic contribution to reduced risk for NTDs; however, factors other than altitude are likely responsible for the low variant allele frequencies in these populations.

Changing practice in residential aged care using participatory methods

BACKGROUND

Residential aged care staff play a significant role in the day-to-day lives of residents yet are faced with many barriers to providing care that promotes resident wellbeing.

APPROACH

Action research is a useful approach for clarifying issues, identifying education and training needs, and identifying, and in some cases overcoming, organizational barriers to change. The Well for Life project aimed to enhance the social and physical health and well being of residents of aged care settings by empowering the staff of facilities to make change. The project had a particular focus on nutrition and physical activity. This paper reports on the action research group process undertaken during Phase I of the Well for Life project. Five residential aged care settings participated in the action research process facilitated by project staff independent of the facilities. The action plan and outcomes from one of these settings is used to illustrate the process and outcomes.

FINDINGS

The main findings of the project indicate that using a process that encourages staff involvement in identification of issues and actions can facilitate change in the practice of resident care. The action research groups identified specific gaps in knowledge and skill leading to targeted education that addressed areas of need. The importance of presenting information and learning opportunities for staff in a variety of formats was also recognized, as was the importance of organizational context, management support and empowerment of staff to make change.

Age patterns of child mortality in the developing world

"This article uses the data from [a] United Nations database, supplemented in a few cases with information from local studies thought to be of particular accuracy, to examine age patterns of child mortality [in developing countries]. The focus is on the split between infant mortality--that is, mortality before the first birthday, and child mortality, between the exact ages of 1 and 5 years.... The underlying objective of the article is to identify regional patterns, both because the epidemiology and social behaviours underlying child mortality are likely to be similar across regions and because such identified patterns could then be used to guide the selection of a model life-table family when using indirect estimation methods in countries of a region."

Temperament, character, and personality disorders: etiologic, diagnostic, treatment issues

OBJECTIVE

In this paper, we explore the underlying dimensional structure of personality disorder, propose a novel approach to its diagnosis, and outline our concepts of its etiology and treatment based on the seven factor psychobiological model of temperament and character.

METHOD

Temperament and character traits were evaluated in a consecutive series of 109 psychiatric out-patients, with or without personality disorder and varying mood and anxiety states.

RESULTS

Low scores on character dimensions consistently correlated with high symptom counts for personality disorder. Each subtype of personality disorder created a unique combination of correlations with the four temperament traits.

CONCLUSION

Temperament and Character Inventory (TCI) temperament and character traits efficiently diagnose personality disorder and differentiate its individual subtypes. Character traits are used to diagnose the presence and the severity of personality disorder, whereas temperament traits are used for differential diagnosis. The distinction between temperament and character provides an attractive theoretical basis for etiological postulates and treatment of personality disorder.

Relationship between change in balance and self-reported handicap after vestibular rehabilitation therapy

BACKGROUND AND PURPOSE

Dizziness and balance problems are two commonly reported symptoms of vestibular system disease, with subsequent alterations in lifestyle and reports of physical, functional and emotional handicap. Vestibular rehabilitation therapy (VRT) was developed to improve the functional status of patients with vestibular dysfunction. The aim of the present study was to investigate the relationship between change in balance performance and change in self-rated handicap after a four-week home exercise programme in 16 subjects with chronic vestibular disease.

METHOD

Before and after the treatment intervention, balance was tested by use of a Smart Balance Master (SBM) system (Neurocom International, Clackamas, OR, USA) and self-rated handicap was measured by use of the Dizziness Handicap Inventory (DHI).

RESULTS

Significant improvement was observed in both the SBM (p < 0.001) and DHI (p = 0.003) scores over the testing period. A moderately strong negative correlation existed between change in SBM and DHI scores (Spearman's r = -0.6). Further analysis using the DHI subscales indicated, however, that the emotional component showed no significant change over time, and a poor correlation with change in balance scores (Spearman's r = -0.39).

CONCLUSIONS

These results indicate that a home-based exercise programme can significantly improve balance abilities in people with chronic vestibular dysfunction, but that outcomes may be enhanced by addressing the emotional issues associated with their disability.

Y-chromosome biallelic polymorphisms and Native American population structure

It has been proposed that women had a higher migration rate than men throughout human evolutionary history. However, in a recent study of South American natives using mtDNA restriction fragment polymorphisms and Y-chromosome microsatellites we failed to detect a significant difference in estimates of migration rates between the sexes. As the high mutation rate of microsatellites might affect estimates of population structure, we now examine biallelic polymorphisms in both mtDNA and the Y-chromosome. Analyses of these markers in Amerinds from North, Central and South America agree with our previous findings in not supporting a higher migration rate for women in these populations. Furthermore, they underline the importance of genetic drift in the evolution of Amerinds and suggest the existence of a North to South gradient of increasing drift in the Americas.

Alu insertions versus blood group plus protein genetic variability in four Amerindian populations

BACKGROUND

Do the population relationships obtained using DNA or blood group plus protein markers remain the same or do they reveal different patterns, indicating that the factors which influence genetic variation at these two levels of analysis are diverse? Can these markers shed light on the biological classification of the Aché, a Paraguayan tribe which only recently established more permanent contacts with non-Indians?

SUBJECTS AND METHODS

To consider these questions we typed 193 individuals from four Amerindian tribes in relation to 12 Alu polymorphisms (five of them never studied in these populations), while 22 blood group plus protein systems were studied among the Aché. These data were then integrated with those previously available (blood groups plus proteins) for the three other populations. DNA extraction and amplification, as well as the other laboratory procedures, were performed using standard methods currently in use in our laboratory. The genetic relationships were obtained using the D(A) distance, and the trees were constructed by the neighbour-joining method, both developed by M. Nei and collaborators. Reliability of the trees was tested by bootstrap replications. Other population variability values were also determined using Nei's methods.

RESULTS

Alu polymorphism was observed in all populations and for most of the loci; in the seven systems from which we could compare our results with those of other Amerindian groups agreement was satisfactory. Unusual findings on the blood group plus protein systems of the Aché were a very low (5%) HP*1 frequency and the presence of the C(W) phenotype in the Rh blood group. The intertribal patterns of relationship and other aspects of their variation were remarkably congruent in the two sets (Alu; blood group plus protein) of systems.

CONCLUSIONS

The answer to the first question posed above is affirmative. However, the problem of whether the Aché derived from a Gê group that preceded the Guarani colonization of Paraguay, or are just a differentiated Guarani group, could not be answered with the genetic information available; the second hypothesis seems more likely at present, but the point to be emphasized is the striking genetic distinctiveness of the Aché as compared to other Amerindians.

Falls Clinics in Australia: a survey of current practice, and recommendations for future development

The aim of this study was to identify common themes and differences in structure and function of Falls Clinics in Australia, to provide a framework for planning future activity. A paper-based survey was circulated to 20 identified Falls Clinic services throughout Australia in late 2000. Fifteen responses (75%) were received, although two of the 15 Clinics were not operating at the time of the survey, and so their responses were not included. Nine of the Clinics had commenced operation since 1998. Staffing commonly included a physiotherapist, geriatrician, and an occupational therapist, with the comprehensive multidisciplinary assessment process taking an average of 130 minutes. Although standard assessment tools were used by more than half of the Clinics, there were no universally applied assessment tools. Waiting lists for initial assessments ranged up to 16 weeks (average 6 weeks). Most Clinics instituted a number of management options themselves, but also used a range of existing community services to provide some of the planned interventions. Limited formal evaluation of the effectiveness of Clinics was reported. Recommended future activity included increasing staff levels and operating times for Clinics to more adequately meet identified need, increased networking and data sharing between Clinics, and a greater emphasis on research and staff training. We conclude that the recent increase in the number of Falls Clinics around Australia has occurred in a relatively unstructured manner, with many differences in staffing, operation and evaluation. There is a need for improved communication and standardisation of core procedures and assessment tools to facilitate best practice in all Clinics, and to provide a framework for a systematic evaluation of the effectiveness of Falls Clinics in Australia.

The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic

OBJECTIVE

Field studies of twentieth century hunter-gathers (HG) showed them to be generally free of the signs and symptoms of cardiovascular disease (CVD). Consequently, the characterization of HG diets may have important implications in designing therapeutic diets that reduce the risk for CVD in Westernized societies. Based upon limited ethnographic data (n=58 HG societies) and a single quantitative dietary study, it has been commonly inferred that gathered plant foods provided the dominant energy source in HG diets.

METHOD AND RESULTS

In this review we have analyzed the 13 known quantitative dietary studies of HG and demonstrate that animal food actually provided the dominant (65%) energy source, while gathered plant foods comprised the remainder (35%). This data is consistent with a more recent, comprehensive review of the entire ethnographic data (n=229 HG societies) that showed the mean subsistence dependence upon gathered plant foods was 32%, whereas it was 68% for animal foods. Other evidence, including isotopic analyses of Paleolithic hominid collagen tissue, reductions in hominid gut size, low activity levels of certain enzymes, and optimal foraging data all point toward a long history of meat-based diets in our species. Because increasing meat consumption in Western diets is frequently associated with increased risk for CVD mortality, it is seemingly paradoxical that HG societies, who consume the majority of their energy from animal food, have been shown to be relatively free of the signs and symptoms of CVD.

CONCLUSION

The high reliance upon animal-based foods would not have necessarily elicited unfavorable blood lipid profiles because of the hypolipidemic effects of high dietary protein (19-35% energy) and the relatively low level of dietary carbohydrate (22-40% energy). Although fat intake (28-58% energy) would have been similar to or higher than that found in Western diets, it is likely that important qualitative differences in fat intake, including relatively high levels of MUFA and PUFA and a lower omega-6/omega-3 fatty acid ratio, would have served to inhibit the development of CVD. Other dietary characteristics including high intakes of antioxidants, fiber, vitamins and phytochemicals along with a low salt intake may have operated synergistically with lifestyle characteristics (more exercise, less stress and no smoking) to further deter the development of CVD.

Falls: a comparison of trends in community, hospital and mortality data in older Australians

BACKGROUND AND AIMS

Falls are major contributors to disability, morbidity and death for older people. Frequently, falls-related data for each of these areas is viewed in isolation. The aim of this study was to establish trends in incidence of falls-related events including: community reporting of falls and falls-related injuries, hospitalizations as a result of accidental falls, and mortality related to accidental falls for older people in two states of Australia (Victoria and South Australia).

METHODS

We analysed data sets for falls hospitalizations and mortality rates for the period 1988 to 1997, and from two longitudinal population-based proportional samples during the same time period.

RESULTS

Age-standardised falls mortality rates have steadily declined in Victoria, and remained unchanged between 1988 and 1997 in South Australia. In both states, age-standardised falls hospitalization rates have increased significantly (in Victoria, RR=1.32, 95% CI: 1.30-1.34; and South Australia, RR=1.05, 95% CI: 1.03-1.06). In both states, there was a clear age-related effect, with those in the 85-year and older age group having a falls-related mortality rate approximately 40 times that of those aged 65-69 years, and a hospitalization rate 9 times that of those in the 65-69 age group. The community studies indicated that falls rates remain high among older Australians, and that injurious falls occurred in 10% in the first wave of data collection in each of these studies.

CONCLUSIONS

The results highlight that various indicators related to falls trends taken in isolation may yield differing conclusions. For a true reflection of the effectiveness of falls prevention programs, falls-related mortality, hospitalization and community data need to be integrated. Increased focus on falls prevention activity in Australia during the 1990's has not reduced the magnitude of this major public health problem.

Broadening the partnerships: experiences of working across community agencies

The creation of inter-agency partnerships to deliver mental health services that meet the health and social care needs of service users is now a central strand of UK national policy and a considerable body of literature has developed around the concept of partnership. The date, however, the focus has been on partnerships between the specialist health and social services, or between these services and primary care. In the course of a study aimed at identifying the mental health training needs of a broader range of community agency staff, it became apparent that partnership working was problematic for the majority of agencies. Focus group discussions were carried out with staff from 21 agencies working across five practice contexts. On the basis of the data obtained we describe the extent of inter-agency working and the barriers to its development. The implications for meeting clients' mental health needs are then considered and means suggested for broadening inter-agency working to include a wider range of relevant agencies.

Demographic methods to assess food insecurity: a North Korean case study

In complex emergencies, especially those involving famine and/or widespread food insecurity, assessments of malnutrition are critical to understanding the population's health status and to assessing the effectiveness of relief interventions. Although the Democratic People's Republic of Korea (DPRK) has benefited from some of the largest, most sustained appeals in the history of the World Food Program (WFP), the government in Pyongyang has placed restrictions on international efforts to gather data on the health and nutritional status of the affected population.

QUESTION

Lacking direct means to assess the nutritional status of the North Korean populace, what other methodologies could be employed to measure the public health impacts of chronic food shortage? The paper begins with a review of methods for assessing nutritional status, particularly in emergencies; a brief history of the North Korean food crisis (1995-2001), and a review of the available nutritional and health data on the DPRK. The main focus of the paper is on the results of a survey of 2,692 North Korean adult migrants in China. Recognizing certain biases and limitations, the study suggests that sample households have experienced an overall decline in food security, as evidenced by both the decline in government rations from an average of 120 grams per person per day to less than 60 grams per day, and by the increase in the percentage of households relying on foraging or bartering of assets as their principal source of food. It also is apparent that the period 1995-1998 has been marked by elevated household mortality, declining fertility, and steadily rising out-migration. Taken together, the signs point toward famine, whether that is defined as a discrete event--that is, as a regional failure in food production or distribution leading to elevated mortality from starvation and associated disease--or as a more complex social process whose sub-states include not only elevated mortality, but declining fertility, eating of alternative 'famine foods', transfer of assets, and the uprooting and separation of families.