Ancient associations of aquatic beetles and tank bromeliads in the Neotropical forest canopy

Water reservoirs formed by the leaf axils of bromeliads are a highly derived system for nutrient and water capture that also house a diverse fauna of invertebrate specialists. Here we investigate the origin and specificity of bromeliad-associated insects using Copelatinae diving beetles (Dytiscidae). This group is widely distributed in small water bodies throughout tropical forests, but a subset of species encountered in bromeliad tanks is strictly specialized to this habitat. An extensive molecular phylogenetic analysis of Neotropical Copelatinae places these bromeliadicolous species in at least three clades nested within other Copelatus. One lineage is morphologically distinct, and its origin was estimated to reach back to 12-23 million years ago, comparable to the age of the tank habitat itself. Species of this clade in the Atlantic rainforest of southern Brazil and mountain ranges of northern Venezuela and Trinidad show marked phylogeographical structure with up to 8% mtDNA divergence, possibly indicating allopatric speciation. The other two invasions of bromeliad water tanks are more recent, and haplotype distributions within species are best explained by recent expansion into newly formed habitat. Hence, bromeliad tanks create a second stratum of aquatic freshwater habitat independent of that on the ground but affected by parallel processes of species and population diversification at various temporal scales, possibly reflecting the paleoclimatic history of neotropical forests.

Evaluation of neonatal sepsis screening in a tropical area. Part II: Evaluation of intrapartum chemoprophylaxis protocol

The authors report on an analysis of a chemoprophylaxis protocol at the University Hospital of Guadeloupe in the Caribbean. This study comprised 6,060 consecutive deliveries and was initiated to assess the application of an intrapartum chemoprophylaxis protocol, evaluate the results, and try to identify possible necessary modifications to the existing protocol. Although more than 90 percent of women had at least one bacterial screening (vaginal or urinary) during the last trimester of pregnancy, approximately 75 percent of mothers who were heavily colonized group B streptococcus (GSB) at delivery were not detected by this systematic screening. As is also reported in other tropical areas where a great portion of nenonatal sepsis occurs in term babies, low birthweight was not a specific risk factor in this study when controlling for other major risk factor such as fever and premature rupture of membranes. Intrapartum chemoprophlaxis was associated wiyh an approximate three fold decrease in the risk of GBS neonatal bacteraemia among at risk deliveries. The results suggest that, in our tropical context, prolonged rupture of membranes of at least 12 hours' duration should be considered as a cause for intrapartum chemopropylaxis as it accounted for the majority of neonatal bacteraemia that escaped the existing protocol. (AU)

Evaluation of neonatal sepsis screening in a tropical area. Part I: Major risk factors of bacterial carriage at birth in Guadeloupe

This prospective study reports on screening for neonatal sepsis among 3,372 live births out of 6,060 consecutive deliveries at the University Hospital of Pointe-a-Pitre, Guadeloupe, during a 30 month period. Group B Streptococcus (GBS) was the most common pathogen, representing 46 percent (89/194) of positive blood cultures and 52 percent (335/637) of positive gastric aspirates. Although only 3,372 (55 percent) of all live births were screened, 637 (10 percent) had gastric bacterial carriage at birth; of those, 335 (5.5 percent) involved GBS. Similarly, there were 194 (3.2 percent) positive blood cultures, of which 89 (1.5 percent) involved GBS. In this report, all newborns who presented with a positive GBS blood culture had at least one of the external tests positive for GBS (gastric, ear canal, rectum and placenta). Thirty-seven per cent (14/38) of positive neonatal blood cultures occurred in newborns with foetid liquor while in deliveries with intrapartum fever 16.5 percent (32/195) of blood cultures were positive. In our clinical practice, characteristics that were evident in the delivery room (without knowledge of prenatal follow-up) such as foetid liquor, intrapartum fever, prolonged rupture of membranes, foetal tachycardia and meconium staining were associated with the great majority of neonatal sepsis.(Au)

Estrus synchronization and artificial insemination of hair sheep ewes in the tropics

Hair sheep ewes (St. Croix White and Barbados Blackbelly) were used to evaluate 3 methods of estrus synchronization for use with transcervical artificial insemination (TAl). To synchronize estrus, ewes (n=18) were treated with PGF2alpha (15 mg, im) 10 d apart, with controlled internal drug release (CIDR) devices containing 300 mg progesterone for 12 d (n=18), or with intravaginal sponges containing 500 mg progesterone for 12 d (n=18). On the day of the second PGF2alpha injection or at CIDR or sponge removal, sterile rams were placed with the ewes. Jugular blood samples were collected from the ewes at 6-h intervals until the time of ovulation, and daily for 16 d after estrus (Day 0). Plasma was harvested and stored at -20 degrees C until LH, and progesterone concentrations were determined by RIA. There was no difference (P>0.10) in time to estrus among the CIDR-, PGF2 alpha- or sponge-treated ewes. All of the ewes in the CIDR group and 94.4 percent of the sponge treated ewes exhibited estrus by 36 h after ram introduction, while only 72.2 percent of PGF2alpha-treated ewes showed signs of estrus by this time (P<0.06). The time from ram introduction to ovulation was not different (P>0.10) among CIDR, PGF2alpha- or sponge-treated ewes. The time to preovulatory LH surge was similar (P>0.10) among treatment groups. Hair sheep ewes (n=23) were synchronized using PGF2alpha and bred by TAI using frozen-thawed semen 48 h after the second injection. The conception rate to TAI was 2/23 (8.7 percent) and produced 3 ram lambs. In a subsequent trial, 17 ewes were synchronized with CIDR devices and bred by TAI using frozen-thawed semen 48 h after CIDR removal, resulting in a conception rate of 52.9 percent (9/17). It is possible to synchronize estrus in hair sheep using either CIDRs, sponges or PGF2alpha. Even though there were no significant differences in the timing of ovulation or the LH surge among the treatment groups, a higher concentration rate was achieved in ewes synchronized with CIDR devices during the second trial. This may reflect an increase in the skill level of the TAI technician.(AU)

The organisation of helicopter emergency services for the rescue of aircraft crash victims in the tropical forest

The purpose of this report was to describe lessons learned from experience in the tropical forest of Guyana and one helicopter rescue mission in that hostile environment. With previous data reported in the literature several guidelines for organizing these operations can be proposed. These rescue operations involve hoisting the victim to helicopter, medical treatment itself, and penetration into a hostile environment. Effectiveness and safety mandate that the physicians involved receive regular training in the techniques of helicopter evacuation, first aid, and survival. It is necessary to adapt conventional first aid kits for the purpose and to develop light and adequate survival equipment as listed exhaustively by the author.(AU)

Childhood dermatitis in the tropics: with special emphasis on infective dermatitis, a marker for infection with human T-cell leukemia virus-I

Eczema in the tropics is a common problem. Although it is a major cause of discomfort among children worldwide, a warm tropical climate often has important repercussions for children with dermatitis. The original description by Sweet empahasized that interest in tropical eczemas extended to the English, as children of West Indian immigrants in England were affected. Likewise, immigrants may carry these disorders with them to the United States. In Jamaica, a tropical country, the largest and most populous of the English-speaking Caribbena islands, eczema is by far the most common skin disorder seen in children attending dermatology clinics. Reports from other Caribbean islands suggest that this is true for the region as a whole. In 1981, Alabi and La Grenade reported that from 1971 to 1975 eczema accounted for 46.7 percent of skin rashes seen in children at the University Hospital of the West Indies. Review of the period 1988 to 1993 showed that 52 percent of the 601 children who attended the skin clinic for the first time had eczema, confirming the earlier finding. In this latter review, atopic eczema was the most common type of eczema (52 percent), followed by seborrheic eczema (20 percent) and infective dermatitis (10 percent). The remaining 18 percent had a variety of unclassified eczemas including pityriasis alba, discoid eczema, acute vesicular eczema of the hands and/or feet, and hyperkeratotic eczema of the feet.(AU)

Urinary fluoride excretion in Jamaica in relation to fluoridated salt

The purpose of this study was to compare the urinary fluoride levels in subtropical Jamaican just before the beginning of salt fluoridation (250mg/kg salt) in 1987 and again 20 months later. Four age groups were studied in three locations with low to intermediate fluoridation as compared with 23.7-67.4 æg/h 20 months after the beginning of the sale of fluoridated salt. The fluoride excretions obtained from 24-hour collections ranged from 169 to 485 æg/24h in 1987 and increased to 304-657 æg/24 h in 1989. In 1987, the morning fluoride excretions approximated those of French and Swiss children who had a low fluoride intake, but the fluoride levels of 1989 were similar to the data obtained from children who had an intake of 1.2-1.7 mg F/day or consumed fluoridated water (AU)

Vitamin D supplementation of post-menopausal women in Curacao, and pre- and post-menopausal women in the Netherlands - abstract

Pre- and post-menopausal white women living in The Netherlands in late winter/early spring and black and white post-menopausal women living in Curacao were supplemented with either 400,800 and 2x400 IU vitamin D (3)/day or placebo for 4, 5, or 9 weeks. Baseline plasma 25-hydroxyvitamin D [25(OH)D] of Dutch women was lower than that of Curacao women. Post-menopausal Dutch women had higher parathyroid hormone (PTH) than pre-menopausal Dutch and post-menopausal Curacao women. There were no differences in 1,25-dihydroxyvitamin D [1,25(OH)2D]. Vitamin D supplementation increased 25(OH)D levels in all groups, PTH and 1,25(OH)2D in post-menopausal Curacao women, and PTH in pre-menopausal Dutch women. Serum and urinary calcium and phosphate did not change. There were no response differences between 400 and 800 IU daily doses, or 800 and 2x400 IU doses. Oral vitamin D supplementation raises late winter/early spring plasma 25(OH)D of women living at high latitudes to baseline levels encountered in the tropics (AU)

Some recent advances in non-communicable diseases in the tropics. 3. Coronary heart disease and associated characteristics in a tropical developing community

Vital statistics indicate that cardiovascular disorders are now major causes of morbidity and mortality in many Caribbean communities. in Trinidad and Tobago, for example, the death rate from myocardial infarction is now similar to that in the UK and USA. In a 10-year prospective survey of 1386 men aged 35 to 69 years at entry, who belonged to a defined community in Port-of-Spain, Trinidad, serum high-density (HDL) and low-density (LDL) lipoprotein cholesterol concentrations were very similar to those found by the same methods in Bristol, England. The age-adjusted incidence of first coronary heart disease (CHD) events in men clinically free of the disease at recruitment (per 1000 person-years) was 16.4 in those of European origin, and 2.4 in men of mixed descent (the contemporaneous figure for Bristol was about 12/1000 person-years). Serum HDL and LDL cholesterol concentrations were strong and independent predictors of CHD in Trinidad, as they are in temperate climes. With efective control of tropical infectious diseases, and adoption of western patterns of consumerism, tropical developing communities will rapidly acquire the CHD risk factor status once more or less exclusive to developed populations in more temperate climes. (AU)

Human T-lymphotropic virus type 1: a retrovirus causing chronic myeloneuropathies in tropical and temperate climates

Human T-cell lymphotropic virus type I (HTLV-I), the first human retrovirus to be isolated, is the cause of endemic tropical spastic paraparesis (TSP). Originally, this chronic neurological disorder was described as a disease seen among blacks of low socioeconomic status living in tropical countries, and thus for many decades TSP remained a little known curiousty outside the endemic regions. The link between HTLV-I infection and TSP was made fortuitously, when antibodies to HTLV-I were found in serum and cerebrospinal fluid of TSP patients in Jamaica, Colombia, and Martinique. Soon thereafter a similar disorder, designated HTLV-I associated myelopathy (HAM), was reported from southern Japan. This broadened the geographic and ethnic boundaries of this chronic myelopathy and the disease has now been reported in multiple ethnic groups from more than 40 countries, in both tropical and temperate regions. The name TSP/HAM is now used to include all patients (regardless of race or country of origin) who have HTLV-I-positive endemic TSP or HAM. (AU)

Intrathecal synthesis of antibodies to human T lymphotropic virus type I and the presence of IgG oligoclonal bands in the cerebrospinal fluid of patients with endemic tropical spastic paraparesis

Tropical spastic paraparesis (TSP), a neuromyelopathy predominantly involving the pyramidal tract and commonly observed in tropical and equatorial areas, was recently found to be associated with human T lymphotropic virus type I (HTLV-I). We investigated sera and cerebrospinal fluid (CSF) from 19 patients with TSP who were from the Caribbean area, French Guiana, and Africa. Our results showed an elevated intra-blood-brain barrier IgG synthesis rate and an elevated IgG index, with an increased HTLV-I antibody-to-albumin ratio and the presence of CSF oligoclonal bands in the majority of the patients. These data, in association with similar HTLV-I antibody patterns between patients with TSP who were from these three regions, strenghten the probable etiologic role of HTLV-I in the pathogenesis of such chronic neuromyelopathies. (AU)

HTLV-I-like viral particles in spinal cord cells in Jamaican tropical spastic paraparesis

Viral-like particles morphologically identical to human T-lymphotropic virus type I or II, but distinct from human T-lymphotropic virus type III, have been seen by electron microscopy in spinal cord tissue from a Jamaican tropical spastic paraparesis patient who was known to be positive for human T-lymphotropic virus I antibody before death. This is the first electron microscopy report on a patient from an endemic tropical spastic paraparesis region. (AU)

The neuroepidemiology of tropical spastic paraparesis

Recent neuroepidemiological studies of endemic tropical spastic paraparesis (TSP) have confirmed the existence of high-prevalence foci in several tropical islands, including Jamaica and Martinique in the Caribbean, Tumaco off the Pacific coast of Colombia, and the Seychelles in the Indian Ocean. There is a net preponderance of TSP in persons of Black African ancestry, although Caucasian, Hindu, Amerindian, and Orientals have been affected. The epidemiological, clinical, laboratory, and neuropathological features of TSP are reviewed here, as well as the evidence in favor of its retroviral origin. (AU)

Antibody to human T-lymphotropic virus type 1 in West-Indian-born UK residents with spastic paraparesis

Of 13 West-Indian-born UK residents with spastic paraparesis of unknown cause, 11 were tested for serum antibody to human T-cell lymphotropic virus type 1 and all were positive. Their magnetic resonance imaging scans were normal or showed only minor abnormalities in the brain, and the spinal cord was normal in the 5 investigated. Of 48 patients with multiple sclerosis, mainly caucasian, none had antibody to HTLV-1 in the blood.(AU)

Estimating genetic values for milk production in the tropics

Variance components and predicted sire values were estimated using 305-d projected and unprojected milk records of varying lenghts. Original data consisted of 15,512 lactation records of daughters of 138 Jamaica Hope sires that calved between 1969 and 1981 in 38 commercial dairy herds in Jamaica. Classification of records had little effect on components of variance. Herd-year-season variance decreased from 36 percent using all lactations to 28 percent with first lactations only. Sire variance was consistently about 10 percent. Cow component of variance accounted for 17 percent of the total variation using all lactations and 36 percent using all lactations of cows with recorded first lactations. Heritabilities for milk by Henderson's method 1 were five to six times larger than estimated from method 3 due to sire by herd confounding. Predicted sire values were between +400 kg and -400 kg. Ranking of sires with at least 5 progeny were considerably infleunced by record classification, especially for sires with highest predicted values. There was less infleunce on rankings when at least 10 progeny per sire were used while the range in predicted sire values was larger using first lactation records only (AU)