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PubMed2002

HLA-DRB1 and HLA-DQB1 polymorphisms in Pacific Islands populations.

Allele frequency distributions of the HLA-DRB1 and HLA-DQB1 genes were investigated in four Pacific Islands populations from the Cook Islands, Samoa, Tokelau and Tonga. Limited diversity was observed for both the HLA-DRB1 and HLA-DQB1 loci. Five HLA-DRB1 alleles were observed to be the most frequent amongst all the studied Pacific Islands populations. They were: HLA-DRB1*0403, HLA-DRB1*08032, HLA-DRB1*09012, HLA-DRB1*11011 and HLA-DRB1*1201. Cook Islanders had the largest number of low frequency DRB1 alleles followed by Samoans, Tokelauans and Tongans, most of which may be attributed to reported non-Polynesian admixture. The most frequently observed DQB1 alleles in the four studied Pacific Islands populations were those of the DQ3 subgroup of alleles HLA-DQB1*03011, HLA-DQB1*0302 and HLA-DQB1*03032 as well as HLA-DQB1*05031 and HLA-DQB1*06011. Cook Islanders had the highest number of rare HLA-DQB1 alleles, the distibution being similar to that of the HLA-DRB1 allele. While, in general, the values of homozygosity for DRB1 and DQB1 were observed to be lower then expected under neutrality, a statistical significance was observed in Tongans, Samoans and Tokelauans for the DQB1 locus and in Tongans for the DRB1 locus. Differences were observed between allele frequency distributions for Tokelauans compared to the other three populations. This was also demonstrated by principal component analysis of DRB1 and DQB1 allele frequencies, which separated the Tokelauan population from Cook Islanders, Tongans and Samoans. Tongans and Samoans were separate from the other Polynesian populations in the phylogenetic trees. Observed allele and haplotype frequencies were found to be in agreement with previously published HLA-DRB and HLA-DQB Polynesian data.

Asian People↗
PubMed2000

Treatment of a biracial child with schizophreniform disorder: cultural formulation.

Over the past several years, the field of psychiatry has shown a higher level of cultural sensitivity and an increasing interest in the role of cultural factors in mental health. This has been notably reflected in the incorporation of cultural considerations, such as an outline for cultural formulation and a glossary of culture-bound syndromes, in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV; American Psychiatric Association, 1994). This case report is illustrative of the significance of considering cultural elements in diagnosing and treating a psychiatric disorder. It is also the first-known detailed case report on fakamahaki, a culture-bound syndrome from the Kingdom of Tonga. The syndrome is described in a child from the perspective of a child psychiatry fellow. To serve as a teaching case for clinicians in training as well as those in practice, the DSM-IV outline for cultural formulation has been used. This case can be helpful in educating others in the mental health field about the utility of a more comprehensive approach to understanding clients in contrast to the growing trend of very focused approaches.

Adolescent↗
PubMed1983

Geographic components of linkage disequilibrium in natural populations of Escherichia coli.

Geographic variation in the genetic structure of natural enteric populations of Escherichia coli was assessed at both the single-locus and dilocus levels from allozyme genotypes at 12 enzyme loci in 178 cell lines isolated from human hosts in Sweden, Iowa, and Tonga. Although there was significant heterogeneity in allele frequencies at six of the 12 loci, geographic variation accounted for only 2.0% of the total genetic diversity (HT = 0.518). Ohta's D-statistics were used to partition the total variance of dilocus linkage disequilibrium into within-population and between-population components. The observed total variance in disequilibrium (0.0339), averaged over 66 locus-pairs, was significantly greater than would be expected (0.0103) if alleles were randomly associated in an unstructured total population; and both within-locality and between-locality components made substantial contributions to the total variance. Half the locus-pairs exhibited the specific dual relationship among components expected when random factors are generating disequilibrium, but 20% of the locus-pairs showed the opposite relationship, reflecting systematic allele associations. The magnitude of dilocus disequilibrium apparently is unrelated to the chromosomal distance between loci. This and other evidence indicates that substitutive recombination rates in natural populations are sufficiently low to permit indirect periodic selection to play a prominent role in generating multilocus genetic structure.

Escherichia coli↗
PubMed2003

Genebanks: a comparison of eight proposed international genetic databases.

OBJECTIVE: To identify and compare population-based genetic databases, or "genebanks", that have been proposed in eight international locations between 1998 and 2002. A genebank can be defined as a stored collection of genetic samples in the form of blood or tissue, that can be linked with medical and genealogical or lifestyle information from a specific population, gathered using a process of generalized consent. METHODS: Genebanks were identified by searching Medline and internet search engines with key words such as "genetic database" and "biobank" and by reviewing literature on previously identified databases such as the deCode project. Collection of genebank characteristics was by an electronic and literature search, augmented by correspondence with informed individuals. The proposed genebanks are located in Iceland, the United Kingdom, Estonia, Latvia, Sweden, Singapore, the Kingdom of Tonga, and Quebec, Canada. Comparisons of the genebanks were based on the following criteria: genebank location and description of purpose, role of government, commercial involvement, consent and confidentiality procedures, opposition to the genebank, and current progress. RESULTS: All of the groups proposing the genebanks plan to search for susceptibility genes for complex diseases while attempting to improve public health and medical care in the region and, in some cases, stimulating the local economy through expansion of the biotechnology sector. While all of the identified plans share these purposes, they differ in many aspects, including funding, subject participation, and organization. The balance of government and commercial involvement in the development of each project varies. Genetic samples and health information will be collected from participants and coded in all of the genebanks, but consent procedures range from presumed consent of the entire eligible population to recruitment of volunteers with informed consent. Issues regarding confidentiality and consent have resulted in opposition to some of the more publicized projects. None of the proposed databases are currently operational and at least one project was terminated due to opposition. CONCLUSIONS: Ambitious genebank projects have been proposed in numerous countries and provinces. The characteristics of the projects vary, but all intend to map genes for common diseases and hope to improve the health of the populations involved. The impact of these projects on understanding genetic susceptibility to disease will be increasingly apparent if the projects become operational. The ethical, legal, and social implications of the projects should be carefully considered during their development.

Canada↗
PubMed1999

Prizes for weight loss.

A programme of weight loss competitions and associated activities in Tonga, intended to combat obesity and the noncommunicable diseases linked to it, has popular support and the potential to effect significant improvements in health.

Female↗
PubMed1991

A 3-year community-based periodontal disease prevention programme for adults in a developing nation.

A field trail of a community programme for improving periodontal health of adults was carried out in a geographically remote, unsophisticated rural population in the South Pacific islands of Tonga. The 3-year project (1986-89) involved three village communities, each with a population of approximately 1200. Village N received supplies of toothbrushes and toothpaste without charge, health education (videos, talks, posters) and periodic dental scaling (ultrasonic). Village K received the same as N except that dental scaling was not provided. Village E received none of the services provided to the villages N and K. Baseline and final examinations of 20-44-year olds showed that unsupervised self-care promoted at the community level, when supplemented with periodic removal of subgingival calculus, significantly improved periodontal health. Improvement was age dependent.

Adult↗
PubMed1986

Health and nutritional status of Tongan preschool children after Cyclone Isaac.

A post-cyclone assessment of the health and nutritional status of preschool children at Ha'apai, Tonga Is, showed lower disease incidence and an unchanged pattern of illness. Height and weight measurements indicated nutrition problems to be chronic and perhaps unrelated to the effects of the disaster. This study supports the hypothesis that natural disasters do not generate new diseases or necessarily lead to disease outbreaks.

Adult↗
PubMed1978

The ascertainment of psychiatric cases in a developing country.

This artricle suggests procedures for locating these individuals in a developing country who have mental health problems. It assumes minimum facilities, e.g. that there is no mental hospital and no qualified psychiatrist and is based on experience in Tonga. The register of those involuntarily admitted to an institution looking after the mentally sick is invaluable for a variety of reasons and will well repay detailed study. Voluntary health and Welfare organisations may also supply valuable data. Home visiting often achieves much more than prearranged hospital or clinic appointments which are often not kept. A study of neglected cases may indicate the need to educate a community to recognize the value of medical treatment for the mentally sick.

Developing Countries↗
PubMed1999

Phylogeny of giant clams (Cardiidae: Tridacninae) based on partial mitochondrial 16S rDNA gene sequences.

We have performed the first DNA molecular phylogenetic analysis of giant clams. An approximately 462-nucleotide fragment of the mitochondrial large ribosomal subunit (16S) was sequenced for all eight species of giant clams and two species of an outgroup taxon, the edible cockle Cerastoderma. The data were analyzed using a maximum parsimony approach and a single most parsimonious tree was found. The resulting phylogenetic hypothesis indicates that the genera Hippopus and Tridacna are monophyletic sister taxa. Tridacna (Chametrachea) is the sister taxon to (T. tevoroa (T. derasa + T. gigas)), with these latter three taxa all being placed in a single subgenus, Tridacna (Tridacna). The number of recognized giant clam species has increased by one-third over the last two decades with the discovery of two rare new species having restricted geographic ranges: H. porcellanus (Palau and the Sulu Archipelago) and T. tevoroa (Tonga and Fiji). These two species lack a known fossil record but exhibit greater genetic distances from sister taxa than do extant giant clam species pairs which are recognizable in Neogene strata, e.g., T. gigas/T. derasa and T. maxima/T. squamosa. We propose that the two new species represent ancient relict lineages of Miocene origin.

Animals↗
PubMed2002

Evolution of insular Pacific Pittosporum (Pittosporaceae): origin of the Hawaiian radiation.

We investigated the origin of Hawaiian Pittosporum and their relationship to other South Pacific Pittosporum species using internal transcribed spacer sequences of nuclear ribosomal DNA. We performed both maximum-parsimony and maximum-likelihood analyses, which produced congruent results. Sequence divergence was 0.0% between Hawaiian members of Pittosporum. These taxa formed a strongly supported clade, suggesting a single colonization event followed by phyletic radiation. Sister to the Hawaiian clade were two South Pacific species, P. yunckeri from Tonga and P. rhytidocarpum from Fiji. This result presents convincing evidence for a South Pacific origin of Hawaiian Pittosporum. Our results also identify a monophyletic group comprising three species representing the Fijian Province and East Polynesia, two introductions onto New Caledonia, and at least one (but possibly two) introduction(s) onto New Zealand. Whether the New Zealand taxa form a monophyletic group is unclear from these data. Previous morphologically based hypotheses, however, suggest the presence of four different lineages occupying New Zealand. The nonmonophyly of the New Caledonian species was not surprising based on the extent of their morphological diversity. Although this latter result is not strongly supported, these species are morphologically complex and are currently the subject of taxonomic revision and molecular systematic analyses.

Base Sequence↗
PubMed1993

Nucleotide sequence, serology and symptomatology suggest that vanilla necrosis potyvirus is a strain of watermelon mosaic virus II.

Vanilla necrosis potyvirus (VNV) is the cause of significant losses to the South Pacific islands vanilla crop. The gene for the coat protein of VNV has been cloned and sequenced. Comparison of this gene with other potyviral coat protein sequences revealed 97% nucleotide sequence homology (98% amino acid homology) to a US isolate of watermelon mosaic virus II (WMV-II), 93% nucleotide sequence homology (96% amino acid homology) to an Australian isolate of WMV-II and 81% nucleotide sequence homology (88% amino acid homology) to soybean mosaic virus-N (SMV-N). Serological analysis, by Western blot and ELISA, confirmed the close relationship between VNV and WMV-II. Furthermore, a limited host range determination found VNV and WMV-II able to infect the same series of test plants. However, symptoms differed significantly on three test species demonstrating that VNV and WMV-II are not identical in biological properties. We suggest that VNV be renamed WMV-II (Tonga).

Amino Acid Sequence↗
PubMed2006

Diversity of killer cell immunoglobulin-like receptor genes in Pacific Islands populations.

Killer immunoglobulin-like receptors (KIRs) regulate the activity of NK and T cells through interaction with specific HLA class I molecules on target cells. To date, 16 KIR genes and pseudogenes have been identified. Diversity in KIR gene content and KIR allelic and haplotype polymorphism has been observed between different ethnic groups. Here, we present data on the KIR gene distribution in Pacific Islands populations. Sixteen KIR genes were observed in Pacific Islands populations from the Cook Islands, Samoa, Tokelau, and Tonga. The majority of KIR genes were present at similar frequencies between the four populations with KIR2DL4, KIR3DL2, and KIR3DP1 genes observed in all individuals. Commonly observed KIR genes in Pacific Islands populations (pooled frequencies) were KIR2DL1 (0.77), KIR2DL3 (0.77), KIR3DL1 (0.65), KIR3DL3 (0.93), KIR2DS4/1D (0.78), and KIR2DP1 (0.82), compared to the less-frequently observed KIR2DL2 (0.27), KIR2DL5 (0.30), KIR2DS1 (0.19), KIR2DS2 (0.27), KIR2DS3 (0.16), KIR2DS5 (0.17), and KIR3DS1 (0.18) genes. Differences in KIR gene frequency distributions were observed between the Pacific Islands populations and when compared to other populations. Sixty-nine different genotypes were identified, with five genotypes accounting for more then 50% of all genotypes observed. The number of genotypes observed in each population was similar in the Cook Islands, Samoan, and Tokelauan populations (19, 18, and 19, respectively), but 26 different genotypes were observed in Tongans. The putative haplotype A was predominantly observed over haplotype B in all Pacific Islands populations. Significant linkage disequilibrium was observed for a number of KIR gene pairs.

Humans↗
PubMed1992

A simple and rapid method of preparing large fragments of dengue virus cDNA from replicative-form RNA using reverse transcriptase and PCR.

A method is described for cloning large fragments (1.5 kb to 2 kb) of dengue virus cDNA from replicative-form viral RNA. Aedes albopictus cells (C6/36 clone) infected with dengue virus contain double-stranded, replicative-form RNA molecules which were used as a template for an initial reverse transcription using a primer containing sequence homologous to regions of the genome at or near the 3' end of the gene being studied. The product was then used as a template for polymerase chain reaction (PCR) amplification using the same 3' primer and a second which hybridized to a region at the 5' end of the sequence to be cloned. Both primers were engineered to contain specific restriction enzyme cutting sites which enabled the PCR product to be cut and cloned directly into plasmids for sequencing and expression studies. We have used this method to construct clones of the envelope glycoprotein gene (E) and the non-structural genes 1 and 2a (NS1/2a) and 3 (NS3) of dengue type 2, Tonga 1974 strain, and E and NS1/2a from dengue type 3, H-87 strain, either as discrete genes or as constructs with long and short leader sequences, with or without anchor sequences. The method could be applied to the cloning of any gene from any flavivirus, directly from infected cell extracts, without the necessity for tedious virus purification steps.

Animals↗
PubMed1988

Histomorphometric analysis of osteopenia associated with endemic osteoarthritis (Mseleni joint disease).

Mseleni Joint Disease (MJD), a polyarticular osteoarthritis of uncertain etiology is endemic among the Tonga-Zulu tribe. The traditional diet is deficient in calcium, and palm wine (2-4% alcohol) is drunk widely. Patients with MJD are reported to be more osteopenic than those without. Iliac bone biopsies of 19 arthritic patients were examined by routine histomorphometry and revealed decreased trabecular bone volume (p less than 0.0005), increased resorption surfaces (p less than 0.01), decreased bone formation rate at the BMU (p less than 0.01) level and increased mineralization lag time (p less than 0.01). Six of the 19 patients (31.6%) had features of osteomalacia and six (31.6%) signs of osteoblast failure. The most likely cause of the bone disorder is calcium deficiency, but inanition, inactivity and alcohol abuse may have contributed. Although the joint disorder may have contributed to the bone disorder, the converse is unlikely the case.

Adult↗
PubMed2006

Perinatal outcomes among Asian American and Pacific Islander women.

OBJECTIVE: The purpose of this study was to examine perinatal outcomes between Asian American and Pacific Islander subgroups. STUDY DESIGN: This is a retrospective study of all Asian American/Pacific Islander women who were delivered at Stanford University Medical Center from 1998 to 2003. Asian American women were subdivided into the following groups: Indian/Pakistani, Chinese, Filipino, Japanese, Korean, Pacific Islanders (individuals from Tonga, Samoa, Guam, or Polynesia), and Vietnamese. Perinatal outcomes included gestational hypertension/preeclampsia, gestational diabetes mellitus, preterm delivery, cesarean delivery, birthweight <2500 g, and birthweight >4000 g. RESULTS: In the study population of 3779 Asian American women, there were statistically significant differences (P < .01) between most of the outcomes that were examined. Filipina women had the highest risk of gestational hypertension/preeclampsia (adjusted odds ratio, 2.21); Indian/Pakistani women had the highest risk of preterm delivery (adjusted odds ratio, 1.67), gestational diabetes mellitus (adjusted odds ratio, 1.39), and low birthweight at term (adjusted odds ratio, 2.30); and Pacific Islander women had the highest risk of macrosomia (adjusted odds ratio, 3.67). CONCLUSION: Significant differences in perinatal outcomes exist between subgroups of the Asian American and Pacific Islander community. Future research on race/ethnicity and perinatal outcomes should examine heterogeneity among these groups before collapsing these individual subgroups into the larger group "Asian." Individuals should be counseled regarding perinatal risk according to their specific Asian subgroup.

Adult↗
PubMed2004

Prevalence of HBsAg mutants and impact of hepatitis B infant immunisation in four Pacific Island countries.

The prevalence rate of hepatitis B virus (HBV) infection in Pacific Island countries is amongst the highest in the world. Hepatitis B immunisation has been incorporated into national programmes at various times, often with erratic supply and coverage, until a regionally co-ordinated programme, which commenced in 1995 ensured adequate supply. The effectiveness of these programmes was recently evaluated in four countries, Vanuatu and Fiji in Melanesia, Tonga in Polynesia and Kiribati in Micronesia. That evaluation established that the programmes had a substantial beneficial impact in preventing chronic hepatitis B infection [Vaccine 18 (2000) 3059]. Several studies of hepatitis B vaccination programmes in endemic countries have identified the potential significance of surface gene mutants as a cause for failure of immunisation. In the study outlined in this paper, we screened infected children and their mothers for the emergence and prevalence of these variants in specimens collected from the four country evaluation. Although the opportunity for the emergence of HBV vaccine escape mutants in these populations was high due to the presence of a considerable amount of the virus in the population and the selection pressure from vaccine use, there were no "a" determinant vaccine escape mutants found. This suggests that vaccine escape variants are not an important cause for failure to prevent HBV transmission in this setting. Other HBsAg variants were detected, but their functional significance remains to be determined. The failure to provide satisfactory protection during such immunisation programmes reflects the need for achieving and sustaining high vaccine coverage, improving the timeliness of doses as well as improving 'cold-chain' support, rather than the selection of vaccine-escape mutants of HBV.

Adult↗
PubMed2005

Preventing chronic diseases: taking stepwise action.

The scientific knowledge to achieve a new global goal for the prevention of chronic diseases--a 2% yearly reduction in rates of death from chronic disease over and above projected declines during the next 10 years--already exists. However, many low-income and middle-income countries must deal with the practical realities of limited resources and a double burden of infectious and chronic diseases. This paper presents a novel planning framework that can be used in these contexts: the stepwise framework for preventing chronic diseases. The framework offers a flexible and practical public health approach to assist ministries of health in balancing diverse needs and priorities while implementing evidence-based interventions such as those recommended by the WHO Framework Convention on Tobacco Control and the WHO Global Strategy on Diet, Physical Activity and Health. Countries such as Indonesia, the Philippines, Tonga, and Vietnam have applied the stepwise planning framework: their experiences illustrate how the stepwise approach has general applicability to solving chronic disease problems without sacrificing specificity for any particular country.

Adult↗
PubMed2003

Emergence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infection in Queensland, Australia.

OBJECTIVES: To investigate the incidence and epidemiology of non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA) infection in south-east Queensland, Australia. STUDY DESIGN: A retrospective survey was done of hospital records of all patients who had non-multiresistant MRSA isolated at Ipswich Hospital (a 250-bed general hospital, 40 km south-west of Brisbane, Queensland, Australia) between March 2000 and June 2001. Laboratory typing of these isolates was done with antibiogram, pulsed-field gel electrophoresis, bacteriophage typing and coagulase gene typing. RESULTS: There were 44 infections caused by nmMRSA. Seventeen infections (39%) occurred in patients from the south-west Pacific Islands (predominantly Samoa, Tonga and New Zealand). Laboratory typing showed that the isolates in Pacific Islanders were Pacific Island strains, and 16/17 of these infections were community acquired. Twenty-three infections (52%) occurred in Caucasians. Eleven of the isolates from Caucasians (48%) were a new predominantly community-acquired strain that we have termed the 'R' pulsotype, nine (39%) were Pacific Island strains, and three (13%) were health care institution-associated strains. Four infections occurred in patients who were not Caucasians or Pacific Islanders. Overall, 34 of all 44 infections (77%) were community acquired. CONCLUSIONS: Non-multiresistant MRSA infection, relatively frequently observed in Pacific Islanders in south-east Queensland, is now a risk for Caucasians as well, and is usually community acquired. Clinicians should consider taking microbiological specimens for culture and antimicrobial susceptibility testing in patients with suspected staphylococcal infections who are not responding to empirical therapy with beta-lactam antibiotics.

Adult↗