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PubMed1995

An analysis of autopsy brain tissue from infants prenatally exposed to methymercury.

Brains from 32 neonatal autopsies from the Seychelles were examined histologically and analyzed for mercury levels. Six brain regions were sampled: frontal and occipital cortex, temporal cortex with hippocampus, basal ganglia with thalamus, cerebellum, and pons with medulla. Tissue blocks for histology and mercury analysis were taken from opposing faces to provide for correlation of findings. Similar studies were performed on 12 reference neonatal brains from Rochester, New York. No clear-cut developmental abnormality was found, but some brains exhibited low-grade, non-specific destructive changes. Total mercury levels, most of it in the organic form, were elevated in many of the Seychelles specimens. No correlation was demonstrated between mercury levels and degree or type of histologic change. There was considerable variability in total mercury for each anatomic region among the 32 Seychelles cases, as well as from one region to another in individual brains. All values of total mercury were under 300 ppb. Statistical analysis of mean mercury levels for each region demonstrated higher values in deep subcortical nuclei, brain stem, and cerebellum, phylogenetically older parts of the brain. When total mercury concentration of each region was paired with all other areas in the same brain and the paired values plotted for the entire group of brains, high correlations were obtained for all brain pairs, suggesting a strong concentration-dependent relationship between mercury intake and brain content. Analysis of mercury levels in separately dissected blocks of grey and white matter from 12 specimens revealed no significant differences between grey and white. In comparison with other human developmental studies and with experimental developmental studies in animals, where toxicity has been demonstrated with total mercury brain levels above 1,000 ppb, this study found no evidence of toxicity within a range of mercury levels below 300 ppb. Submicroscopic changes, subcellular alterations, subtle disturbances in the unfolding of brain architectonics -- none of these are excluded with methods used in this report. Further studies of threshold effects of MeHg on fetal brain are essential. That approximately half of the mercury resides in glial elements in white matter reinforces the need to focus attention upon glia as well as neurons during development.

Brain↗
PubMed1997

Simulation of large-scale tropical tuna movements in relation with daily remote sensing data: the artificial life approach.

Tunas are known to be able to travel long distances. The aim of this paper is to propose new ethological models which reproduce some tuna movements using the dynamics of their environment. We use sea surface temperature animations (from remote sensing data) to model the South West Indian Ocean, and French purse seiners data are used to estimate movements of fish. The objective of the models will be to find a northern movement from the Mozambique Channel to the Seychelles Islands at the appropriate time (May-July). The initial model uses our ecological knowledge of tunas, i.e. the search behavior for high concentrations of food commonly associated with thermal fronts. In some cases, this simple model creates some northern movements from the Mozambique Channel, but it cannot be used to reproduce large-scale movements between the Mozambique Channel and the Seychelles Islands. The next generation model is created where tuna behaviors are modeled by an artificial neural network, using a genetic algorithm to adjust the connection weights. The tuna school-network receives daily information from its local environment and chooses the best actions in order to be able to pass from the Mozambique Channel to the Seychelles Islands at the appropriate time. One neural network emerges and represents an adaptive behavior able to interpret daily sea surface temperatures to mimic large-scale tuna movements. This artificial behavior can be generalized to each possible departure position from the Mozambique Channel. This modelling represents a new tool to study large-scale movements of pelagic fish, and is a first step towards real-time management of fisheries.

Algorithms↗
PubMed2000

Wolbachia segregation rate in Drosophila simulans naturally bi-infected cytoplasmic lineages.

Wolbachia are maternally transmitted endocellular bacteria infecting several arthropod species. In order to study Wolbachia segregation rate, Drosophila simulans females from an Indo-Pacific population (Seychelles) bi-infected by the two Wolbachia variants wHa and wNo were backcrossed to uninfected males in two conditions. In the first case, Seychelles males from a stock cured from its Wolbachia by tetracycline treatment were used. In the second case, the males came from a naturally uninfected Tunisian population. It was found that (i) the two Wolbachia variants can segregate, so that bi-infected females can produce a few offspring infected only by wHa or wNo. This occurs in both backcross conditions. (ii) Segregation leads more frequently to wHa than to wNo mono-infection. (iii) Wolbachia transmission is lower when the Seychelles genome is introgressed by the Tunisian genome, suggesting that host genomic factors might influence infection fate.

Animals↗
PubMed2003

Chilling-induced photoinhibition in nine isolates of Valonia utricularis (Chlorophyta) from different climate regions.

Chilling induced inhibition of photosynthesis was studied in nine isolates of the marine tropical to warm-temperate green macrophyte Valonia utricularis (Roth) C. Agardh. According to their temperature requirements for growth and survival, the isolates belong to a cold-tolerant Atlantic/Mediterranean group and a cold-sensitive Indo-west Pacific group. After 5 hours exposure to 5 degrees C under moderate light, all isolates experienced similar substantial photoinhibition, which approached steady state levels after a decline in Fv/Fm to about 40% of the initial values. After return to optimal temperature and dim light conditions, Fv/Fm values increased with biphasic kinetics. A fast phase with half-life times of less than 30 minutes (dynamic photoinhibition) was followed by a slow phase lasting a few hours, indicating repair of photodamaged PSII reaction centres (chronic photoinhibition). In the Atlantic/Mediterranean isolates the fast phase accounted for more than 80 % of the recovery response, showing that these isolates were able to cope with the applied low temperature stress by down-regulating their PSII reaction centres. In contrast, the two isolates from the Seychelles were predominantly photodamaged. In a second experiment, three isolates (Corsica, Seychelles, Japan) were exposed to a similar relative amount of cold stress (0, 10, 15 degrees C, respectively). The Japanese isolate and the isolate from the Seychelles showed significantly less inhibition compared to 5 degrees C exposure, but no significant difference was found in the Corsican isolate. However, the degree of low temperature stress had no significant influence on the relative contributions of dynamic and chronic photoinhibition. Only two of the seven investigated isolates had a lower final inhibition level when grown at sub-optimal temperatures than at optimal temperatures. However, all sub-optimally grown Atlantic/Mediterranean isolates exhibited faster recovery kinetics from chilling-induced photoinhibition than optimally grown plants. This is related to a faster recovery from chronic photoinhibition than to a higher relative contribution of dynamic photoinhibition. A specific role of the photoprotective pigments of the xanthophyll cycle, leading to an acclimation response in the Atlantic/Mediterranean isolates may be involved. We conclude that ecotypic differentiation in V. utricularis is mirrored in different degrees of susceptibility to low temperature stress.

Acclimatization↗
PubMed1996

Expanded programme on immunization (EPI). Immunization schedules in the WHO African region, 1995.

There are 48 countries/areas in this Region (Tables 1-3). No data are available from Reunion and Saint Helena. BCG is given at birth in 46 countries. Diphtheria-pertussis-tetanus (DPT) vaccine is used as a primary series of 3 doses in 46 countries. In 35 countries, DPT is given from 6 weeks of age; in 6 countries at 2 months of age (Angola, Botswana, Burkina Faso, Congo, Gambia and Zambia); and in 5 countries at 3 months of age (Algeria, Mauritius, Seychelles, Swaziland and Zimbabwe). Eight countries give 4 doses of DPT (Benin, Burundi, Congo, Equatorial Guinea, Rwanda, Seychelles, South Africa and Zambia) while 2 countries give 5 doses of DPT (Algeria and Togo). Diphtheria-tetanus (DT) is given in 3 countries: in Botswana at 6 years, in Mauritius at 2 and 5 years and in South Africa at 5 years of age. No Td* is given in any of the countries in this Region. Oral poliovirus vaccine (OPV) is used in a primary series of 3 doses simultaneously with DPT vaccine in all countries. Eighteen countries give OPV at birth. Measles vaccine is given at 9 months of age in 45 countries. Seychelles gives measles vaccine at 15 months of age. None of these countries give a combined measles-mumps-rubella (MMR) vaccine. Rubella vaccine alone is also not given in any of the countries in the Region. Hepatitis B vaccine is used in 7 countries (Botswana, Gabon, Gambia, Nigeria, South Africa, Uganda and Zimbabwe). It is given in 2 doses in 2 countries (Gambia and Nigeria) and at birth in 4 countries (Botswana, Gabon, Gambia and Nigeria). Thirty-one countries are at risk for yellow fever. However, yellow fever vaccine is given only in 10 countries (Central African Republic, Chad, Côte d'Ivoire, Gabon, Gambia, Ghana, Niger, Sao Tome and Principe, Senegal and Togo). Six countries give yellow fever vaccine at 9 months, Chad gives it at 6 months, Gabon and Sao Tome and Principe at 1 year of age and Togo at 10 months. Tetanus toxoid (TT) is used for pregnant women or non-pregnant women of childbearing age. The schedules include 2 to 5 doses. Forty-two countries use a 5-dose schedule. TT is given to schoolchildren in 5 countries (Botswana, Comoros, Guinea, Lesotho and Madagascar).

Africa↗
PubMed1998

[Human diseases transmitted by Culicidae in southwest Indian Ocean islands].

South-West Indian Ocean islands were inhabited at the beginning and free from all kind of vector. In Madagascar, Mayotte, Moheli and Anjouan, malaria vectors were carried by the first settlements. According to epidemics, the anopheles arrived in 1867 in Mauritius, 1869 in La Reunion and 1920 in Grande Comore. Rodrigues, Saint-Brandon and the Seychelles are still free from malaria vectors in the coastal part of Madagascarcar and in Comores archipelago, malaria is stable with a permanent transmission. Unstable malaria is seasonaly transmitted in the high territories of Madagascar; it was the same in Mauritius and Reunion island before the eradication campaign. Lymphatic filariasis is quoted in Madagascar, but Comores archipelago is an area with high transmission. The incidence of the disease is moderate in La Reunion and Mauritius and very low in Chagos and Seychelles archipelagos. There is no transmission in Rodrigues and St Brandon. Epidemics of dengue were described during the second part of the XIXth century in Mauritius and La Reunion, then in 1943 in Mayotte. But the disease was controlled in the fifties by the antimalaria campaign. A new epidemy appeared in Seychelles by the end of 1976 and then in Reunion and Mauritius next year. An isolated outbreak was described in Grande Comore only in 1994.

Animals↗
PubMed2000

Association between prenatal exposure to methylmercury and cognitive functioning in Seychellois children: a reanalysis of the McCarthy Scales of Children's Ability from the main cohort study.

Methylmercury (MeHg) is a neurotoxicant whose high-dose effects first became known following a number of poisoning outbreaks that occurred worldwide. The primary human exposure is low dosage from fish consumption. Studies of fish-eating populations have not found a consistent pattern of association between exposures and outcomes. Therefore, examining specific areas of cognitive functioning has been suggested as an important approach to determine whether more subtle effects of MeHg exposure are present. In the Seychelles longitudinal study of prenatal and postnatal MeHg exposure from fish consumption and development, the McCarthy Scales of Children's Abilities (MSCA) were administered to children at age 66 months. No association between MeHg exposure and performance on the MSCA General Cognitive Index was identified. We analyzed these data further to determine whether associations were present on specific subscales of the MSCA. The standard MSCA subscales were analyzed. Then, more specific subscales of the MSCA were defined and analyzed utilizing a neuropsychological approach. The subscales were recombined to approximate the domains of cognitive functioning evaluated in the Faroes and New Zealand studies. Analyses of both the standard and the recombined MSCA subscales showed no adverse associations with MeHg exposure and neuropsychological endpoints. A positive association between postnatal MeHg exposure and performance on the MSCA Memory subscale was found. These findings are consistent with previous reports from the Seychelles study in that no adverse effects of MeHg exposure from fish consumption can be detected in this cohort.

Animals↗
PubMed2000

High prevalence of peripheral atherosclerosis in a rapidly developing country.

Cardiovascular disease is rapidly increasing in developing countries experiencing epidemiological transition. We investigated the prevalence of peripheral atherosclerosis in a rapidly developing country and compared our findings with data previously reported in Western populations. A cardiovascular risk factor survey was conducted in 1067 individuals aged 25-64 randomly selected from the general population of Seychelles. High-resolution ultrasonography of the right and left carotid and femoral arteries was performed in a random subgroup of 503 subjects (245 men and 258 women). In each of the four arteries, arterial wall thickness (in plaque-free segments) and atherosclerotic plaques (i.e. focal wall thickening at least 1.0 mm thick) were measured separately. The prevalence of peripheral atherosclerosis was high in this population. For instance, at least one plaque > or =1.0 mm was found in, respectively, 34.9 and 27.5% of men and women aged 25-34 and at least one plaque > or =2.5 mm was found in, respectively, 58.2 and 36.9% of men and women aged 55-64. With reference to data found in the literature, the prevalence of carotid atherosclerosis appeared to be significantly higher in Seychelles than in Western populations. This study provides further evidence for the importance of cardiovascular disease in developing countries. Determinants should be identified and relevant prevention and control programs implemented.

Adult↗
PubMed2006

Prevalence of elevated blood pressure and association with overweight in children of a rapidly developing country.

We assessed the prevalence of elevated blood pressure (BP) and the association with excess body weight among a large sample of children in the Seychelles, a middle-income rapidly developing country in the African region. Weight, height and BP were measured in all children of four school grades in the Seychelles (Indian Ocean). Excess weight categories ('overweight' and 'obesity') were defined according to the criteria of the International Obesity Task Force. Two BP readings were obtained on one occasion. 'Elevated BP' was defined based on US reference tables. Data were available in 15,612 (86%) of 18,119 eligible children aged 5-16 years in 2002-2004. In all, 13.0% of Boys and 18.8% of girls were overweight or obese. The prevalence of elevated BP was 9.1% in boys and 10.1% in girls. Both systolic and diastolic BP were strongly associated with body mass index (BMI) in boys and in girls. In children with 'normal weight', 'overweight (and not obesity)' and 'obesity', respectively, proportions with elevated BP were 7.5, 16.9 and 25.2% in boys, and 7.5, 16.1 and 33.2% in girls. Overweight (including obesity) could account for 18% of cases of elevated BP in boys and 26% in girls. Further studies should examine the impact of the relationship between BMI and elevated BP on the burden of hypertension in the context of the epidemic of paediatric obesity.

Adolescent↗
PubMed2003

Methods and rationale for derivation of a reference dose for methylmercury by the U.S. EPA.

In 2001, the U.S. Environmental Protection Agency derived a reference dose (RfD) for methylmercury, which is a daily intake that is likely to be without appreciable risk of deleterious effects during a lifetime. This derivation used a series of benchmark dose (BMD) analyses provided by a National Research Council (NRC) panel convened to assess the health effects of methylmercury. Analyses were performed for a number of endpoints from three large longitudinal cohort studies of the neuropsychological consequences of in utero exposure to methylmercury: the Faroe Islands, Seychelles Islands, and New Zealand studies. Adverse effects were identified in the Faroe Islands and New Zealand studies, but not in the Seychelles Islands. The NRC also performed an integrative analysis of all three studies. The EPA applied a total uncertainty factor (UF) of 10 for intrahuman toxicokinetic and toxicodynamic variability and uncertainty. Dose conversion from cord blood mercury concentrations to maternal methylmercury intake was performed using a one-compartment model. Derivation of potential RfDs from a number of endpoints from the Faroe Islands study converged on 0.1 microg/kg/day, as did the integrative analysis of all three studies. EPA identified several areas for which further information or analyses is needed. Perhaps the most immediately relevant is the ratio of cord:maternal blood mercury concentration, as well as the variability around this ratio. EPA assumed in its dose conversion that the ratio was 1.0; however, available data suggest it is perhaps 1.5-2.0. Verification of a deviation from unity presumably would be translated directly into comparable reduction in the RfD. Other areas that EPA identified as significant areas requiring further attention are cardiovascular consequences of methylmercury exposure and delayed neurotoxicity during aging as a result of previous developmental or adult exposure.

Cohort Studies↗
PubMed1993

HTLV-I associated myelopathy in a Seychellois immigrant.

OBJECTIVE: To describe the clinical and laboratory features of human T-lymphotropic virus type I (HTLV-I) associated myelopathy in an immigrant from the Seychelles. CLINICAL FEATURES: A slowly progressive myelopathy has been recently diagnosed in a 64-year-old woman who emigrated to Australia from the Seychelles in 1957. Sphincter disturbance and back pain were the first manifestations, followed by gait disturbance. Neurophysiological investigation supported the clinical diagnosis of a myelopathy and radiological investigations revealed no structural cause. Serum antibodies to HTLV-I were detected by enzyme-linked particle agglutination and the presence of antibodies to individual HTLV-I gene products in the serum was confirmed by western blot. The virus was detected in a culture of the patient's peripheral blood mononuclear cells by antigen capture assay and by sequencing a polymerase chain reaction product amplified from the env gene. INTERVENTION AND OUTCOME: The patient was advised of the nature and prognosis of her illness. Oral corticosteroids were tried without benefit. CONCLUSIONS: The prevalence of HTLV-I infection is low in Australia although it may be endemic in some Aboriginal communities. Most infections are asymptomatic but the chronic neurological disease associated with HTLV-I infection has now been shown to exist in this country. HTLV-I infection should be considered in the aetiology of myelopathy without another obvious cause.

Australia↗
PubMed1995

Main neurodevelopmental study of Seychellois children following in utero exposure to methylmercury from a maternal fish diet: outcome at six months.

Methylmercury (MeHg) is a human neurotoxin to which the developing fetal brain is especially sensitive. The lowest dose of MeHg that impairs neurodevelopment in the human fetus is not known. The Seychelles Child Development Study (SCDS) is testing the hypothesis that fetal MeHg exposure from a maternal diet high in oceanic fish is related to child neurodevelopmental outcomes. Fish is the major protein source in the Republic of Seychelles, where a cohort of 779 mother-infant pairs was enrolled in a prospective longitudinal study. Maternal total hair mercury values during pregnancy were determined by cold vapor atomic absorption and ranged from 0.5 ppm to 26.7 ppm with a median of 5.9 ppm. When the children were 6 1/2 months of age, an examiner blinded to the maternal mercury value performed a neurological examination, the Fagan test of visual recognition memory, and the Denver Developmental Screening Test-Revised (DDST-R). On the DDST-R 2% scored other than normal while 3.4% had an overall neurological score other than normal. The Fagan test of visual recognition memory showed a median score of 60.5%, and the Rose attention measure from that test showed a median score of 37.9. The association between fetal mercury exposure and neurodevelopmental endpoints was examined by multiple regression analyses. After adjusting for covariates, no association between the maternal hair mercury level during pregnancy and an adverse neurodevelopmental outcome of the child was identified at 6 1/2 months of age.

Adult↗
PubMed1995

Longitudinal neurodevelopmental study of Seychellois children following in utero exposure to methylmercury from maternal fish ingestion: outcomes at 19 and 29 months.

UNLABELLED: Despite the importance of defining developmental consequences for humans of in utero exposure to low levels of methylmercury, it is not yet clear if there are postnatal effects in fish-eating populations. The Seychelles Child Development Study (SCDS), now underway in the Republic of Seychelles, is following children to test the hypothesis that prenatal exposure to low concentrations of MeHg through maternal ingestion of fish is related to child development outcomes. In this study, children were evaluated with the Bayley Scales of Infant Development (BSID) at 19 mos. of age (N = 738). The cohort was evaluated again at 29 mos. (N = 736) with the BSID and the Bayley Infant Behavior Record. Mercury exposure determined by cold vapor atomic absorption analysis of maternal hair segments corresponding to pregnancy revealed a median exposure of 5.9 ppm (Range 0.5 - 26.7 ppm). The association between maternal hair mercury concentrations and neurodevelopmental outcomes at 19 and 29 mo. of age was examined by multiple regression analysis with adjustment for confounding variables. RESULTS: BSID Intertester reliability was ascertained by the Kappa statistic and was high. The mean BSID Mental Scale Indexes at both 19 and 29 mo. were comparable to the mean performance of US children. The mean BSID Psychomotor Scale Indexes at 19 and 29 mo. were 2 SD units above US norms, but consistent with previous findings of motoric precocity in children reared in African countries. No effect of mercury was detected on BSID scores at either age. On the Bayley Infant Behavior Record, activity level in boys, but not girls, decreased with increasing mercury exposure. Only one subjective endpoint was correlated with prenatal exposure to mercury. This study may have implications for environmental health policies concerning mercury in fish or fish consumption during pregnancy. Follow-up data are needed to determine if adverse effects occur at older ages and if such effects are determined to be related to mercury.

Adult↗
PubMed2004

The US EPA reference dose for methylmercury: sources of uncertainty.

The US Environmental Protection Agency (EPA) derived a reference dose for methylmercury in 2001, based on an extensive analysis by the National Research Council (NRC) of the National Academy of Sciences. The NRC performed benchmark dose analysis on a number of endpoints from three longitudinal prospective studies: the Seychelles Islands, the Faroe Islands, and the New Zealand studies. Adverse effects were reported in the latter two studies, but not in the Seychelles study. The NRC also performed an integrative analysis of all three studies. Dose conversion from cord blood or maternal hair mercury concentration was performed by EPA using a one-compartment pharmacokinetic model. A total uncertainty factor of 10 was applied for intrahuman pharmacokinetic and pharmacodynamic variability. There are numerous decisions made by the NRC/EPA that could greatly affect the value of the reference dose (RfD). Some of these include the choice of a linear model for the relationship between mercury body burden and neuropsychological performance, the choice of values of P0 and the benchmark response, the use of the "critical study/critical endpoint" approach in the interpretation of the maternal body burden that corresponds to the RfD, the use of central tendencies in a one-compartment pharmacokinetic model rather than the inclusion of the distributions of variables for the population of reproductive-age women, the assumption of unity for the ratio of fetal cord blood to maternal blood methylmercury concentrations, the choice of a total of 10 as an uncertainty factor, and the lack of dose-response analysis for other health effects such as cardiovascular disease. In addition, it may be argued that derivation of a RfD for methylmercury is inappropriate, given that there does not appear to be a threshold for adverse neuropsychological effects based on available data.

Adult↗
PubMed2002

A molecular phylogeny of African kestrels with reference to divergence across the Indian Ocean.

In this paper we examine the evolutionary relationships of kestrels from mainland Africa, Indian Ocean islands and related areas. We construct a molecular phylogeny of African kestrels, using approximately 1.0 kb of mitochondrial cytochrome b sequence. Our molecular results support an Old World origin for typical kestrels and an ancient divergence of kestrels into the New World, and indicate a more recent radiation of kestrels from Africa via Madagascar towards Mauritius and the Seychelles. Phylogenetic placement of the Australian kestrel suggests a recent origin from African kestrel stock. We compare evolutionary relationships based on kestrel plumage pattern and morphology to our molecular results for the African and Indian Ocean kestrels, and reveal some consistency with the different island forms. We apply a range of published avian cytochrome b substitution rates to our data, as an alternative to internal calibration of a molecular clock arising from incomplete paleontological information. We align these divergence estimates to the geological history of Indian Ocean island formation inferred from potassium-argon dating methods. The arrival of kestrels on Mauritius appears consistent with the cessation of volcanic activity on Mauritius. The estimated time and route of divergence of the Seychelles kestrel from Madagascar may be compatible with the emergence of smaller islands during Pleistocene sea level fluctuations.

Animals↗
PubMed2004

Biogeography of the Pistia clade (Araceae): based on chloroplast and mitochondrial DNA sequences and Bayesian divergence time inference.

Pistia stratiotes (water lettuce) and Lemna (duckweeds) are the only free-floating aquatic Araceae. The geographic origin and phylogenetic placement of these unrelated aroids present long-standing problems because of their highly modified reproductive structures and wide geographical distributions. We sampled chloroplast (trnL-trnF and rpl20-rps12 spacers, trnL intron) and mitochondrial sequences (nad1 b/c intron) for all genera implicated as close relatives of Pistia by morphological, restriction site, and sequencing data, and present a hypothesis about its geographic origin based on the consensus of trees obtained from the combined data, using Bayesian, maximum likelihood, parsimony, and distance analyses. Of the 14 genera closest to Pistia, only Alocasia, Arisaema, and Typhonium are species-rich, and the latter two were studied previously, facilitating the choice of representatives that span the roots of these genera. Results indicate that Pistia and the Seychelles endemic Protarum sechellarum are the basalmost branches in a grade comprising the tribes Colocasieae (Ariopsis, Steudnera, Remusatia, Alocasia, Colocasia), Arisaemateae (Arisaema, Pinellia), and Areae (Arum, Biarum, Dracunculus, Eminium, Helicodiceros, Theriophonum, Typhonium). Unexpectedly, all Areae genera are embedded in Typhonium, which throws new light on the geographic history of Areae. A Bayesian analysis of divergence times that explores the effects of multiple fossil and geological calibration points indicates that the Pistia lineage is 90 to 76 million years (my) old. The oldest fossils of the Pistia clade, though not Pistia itself, are 45-my-old leaves from Germany; the closest outgroup, Peltandreae (comprising a few species in Florida, the Mediterranean, and Madagascar), is known from 60-my-old leaves from Europe, Kazakhstan, North Dakota, and Tennessee. Based on the geographic ranges of close relatives, Pistia likely originated in the Tethys region, with Protarum then surviving on the Seychelles, which became isolated from Madagascar and India in the Late Cretaceous (85 my ago). Pistia and Protarum provide striking examples of ancient lineages that appear to have survived in unique or isolated habitats.

Araceae↗
PubMed1994

Seroepidemiology, viral isolation, and molecular characterization of human T cell leukemia/lymphoma virus type I from La Réunion Island, Indian Ocean.

Data indicate the presence in the Seychelles Islands of a high level of human T cell leukemia/lymphoma virus type I (HTLV-I) endemicity as well as the presence of tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). We present here the results of an hospital survey performed since 1988 in La Réunion Island, located in the Indian Ocean southeast of the Seychelles archipelago, aimed at evaluating HTLV-I endemicity, detecting HTLV-I-associated diseases, and characterizing viral isolates. Seven individuals were found to have HTLV-I-specific antibodies in their sera. These include 3 of 257 patients from St. Pierre Hospital, 1 of them exhibiting a typical clinical feature of TSP/HAM (the first described case in this region), 1 blood donor of 3900, and 3 relatives. A further nine individuals exhibiting only "gag-encoded proteins" by Western blot (p19 and/or p24 bands) were found negative by polymerase chain reaction using LTR, pol, and tax HTLV-I specific primers. A long-term T cell line, designated Mel.J, exhibiting T cell activation markers (CD4+, CD25+, HLA-DR+), and producing HTLV-I antigens and viral particles, was established from one of the HTLV-I,-seropositive patients. The sequence of a 522-bp fragment corresponding to the carboxy terminus of gp46 and the majority of gp21 were determined for five HTLV-I-seropositive individuals, including the TSP/HAM patient. Alignment and phylogenetic comparison of these five nucleotide sequences with all the 53 other available HTLV-I env sequences demonstrated that the virus from La Réunion Island belongs to the group of the HTLV-I cosmopolitan subtype and is not related to the Melanesian HTLV-I variants.

Adult↗
PubMed1994

Systematic difference between blood pressure readings caused by cuff type.

In this study we determine whether blood pressure readings using a cuff of fixed size systematically differed from readings made with a triple-bladder cuff (Tricuff) that automatically adjusts bladder width to arm circumference and assessed subsequent clinical and epidemiological effects. Blood pressure was measured with a standard cuff or a Tricuff in 454 patients visiting an outpatient clinic in the Seychelles (Indian Ocean). Overall means of within-individual standard cuff-Tricuff differences in systolic and diastolic blood pressures were examined in relation to arm circumference and sex. The standard cuff-Tricuff difference in systolic and diastolic blood pressures increased monotonically with circumference (from 4.7 +/- 0.8/3.2 +/- 0.7 mm Hg for arm circumference of 30 to 31 cm to 10.0 +/- 1.1/8.0 +/- 0.9 mm Hg for arm circumference > or = 36 cm) and was larger in women than men. Multivariate linear regression indicated independent effects of arm circumference and sex. Forty percent of subjects with a diastolic blood pressure of > or = 95 mm Hg measured with a standard cuff had values less than 95 mm Hg measured with a Tricuff. Extrapolation to the entire population of the Seychelles decreased the prevalence of blood pressure greater than or equal to 160/95 mm Hg by 11.5% and 24.0% in men and women, respectively, aged 35 to 64 years. The age-adjusted effect of body mass index on systolic and diastolic blood pressures decreased twofold using blood pressure readings made with a Tricuff instead of a standard cuff.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗