Toxicity assessment for the horseshoe crab Carcinoscorpius rotundicauda collected from Cambodia.

In this study, we assessed the toxicity of the horseshoe crab Carcinoscorpius rotundicauda collected from Cambodia within two successive months during rainy (April-May) and dry (December-January) seasons, respectively. Toxicity assessments of the collected specimens by standard mouse bioassay showed marked individual variation, and their toxin profiles by liquid chromatography/mass spectrometry (LC/MS) revealed tetrodotoxin (TTX) was the main toxin while no paralytic shellfish toxins (PSTs) were detected. All specimens were toxic and the highest toxicity values were 315, 113, 60, 47, 44 and 38 mouse units (MU)/g in the tissues of hepatic caecum, egg, viscera, muscle, intestine and testis, respectively. Although the current findings showed that the Cambodian C. rotundicauda was a moderately toxic species, they are not suitable for human consumption due to their toxicity. To the best of our knowledge, this is the first scientific study on toxic marine seafood ever investigated in Cambodian territorial waters.     

Maturation-associated changes in toxicity of the pufferfish Takifugu poecilonotus

From October 2006 to December 2007, wild specimens of the pufferfish Takifugu poecilonotus (93 females, 45 males) were collected from the Ariake Sea. Tissue toxicity was examined by mouse bioassay, and tetrodotoxin (TTX) content in the blood plasma by enzyme-linked immunosorbent assay. The relationship between toxicity and maturation was investigated based on changes in the gonadosomatic index: December-March in females and November-March in males, the ‘maturation period’; April, ‘just after spawning’; and the other months, the ‘ordinary period’. Toxicity of both sexes was high throughout the year, but sharply declined in April. In all tissues examined (skin, liver, and ovary) other than testis, toxicity exceeded 1000 MU/g or 10,000 MU/individual in many individuals. Seasonal profiles of tissue toxicity differed markedly between sexes. In females, liver toxicity was high during the ordinary period, and ovary toxicity was high during the maturation period. In males, little maturation-associated change in the toxin distribution was observed. Plasma TTX levels were similar between the sexes (1.59–15.1 MU/ml), and fluctuated largely throughout the year without corresponding changes in tissue toxicity. The percentage of TTX binding to high molecular-weight substances in the plasma varied in association with maturation; the binding ratio fluctuated at relatively low levels during the ordinary period, and stabilized at a high level during the maturation period.     

Phylogeny and Toxin Profile of Freshwater Pufferfish (Genus Pao) Collected from 2 Different Regions in Cambodia

The species classification of Cambodian freshwater pufferfish is incomplete and confusing, and scientific information on their toxicity and toxin profile is limited. In the present study, to accumulate information on the phylogeny and toxin profile of freshwater pufferfish, and to contribute to food safety in Cambodia, we conducted simultaneous genetic-based phylogenetic and toxin analyses using freshwater pufferfish individuals collected from Phnom Penh and Kratie (designated PNH and KTI, respectively). Phylogenetic analysis of partial sequences of three mitochondrial genes (cytochrome b, 16S rRNA, and cytochrome c oxidase subunit I) determined for each fish revealed that PNH and KTI are different species in the genus Pao (designated Pao sp. A and Pao sp. B, respectively). A partial sequence of the nuclear tributyltin-binding protein type 2 (TBT-bp2) gene differentiated the species at the amino acid level. Instrumental analysis of the toxin profile revealed that both Pao sp. A and Pao sp. B possess saxitoxins (STXs), comprising STX as the main component. In Pao sp. A, the toxin concentration in each tissue was extremely high, far exceeding the regulatory limit for STXs set by the Codex Committee, whereas in Pao sp. B, only the skin contained high toxin concentrations. The difference in the STX accumulation ability between the two species with different TBT-bp2 sequences suggests that TBT-bp2 is involved in STX accumulation in freshwater pufferfish.     

Assessment of Trachoma in Cambodia: Trachoma Is Not a Public Health Problem

ABSTRACT

Purpose: To determine whether trachoma is a public health problem requiring intervention in Cambodia.

Methods: Based on historical evidence and reports, 14 evaluation units (EUs) in Cambodia, judged to be most likely to harbor trachoma, were selected. The Global Trachoma Mapping Project methodology was used to carry out rigorous surveys to determine the prevalence of trachomatous inflammation–follicular (TF) and trichiasis in each EU.

Results: The EU-level prevalence of TF among 25,801 1–9-year-old children examined ranged from 0% to 0.2%. Among the 24,502 adults aged 15+ years examined, trichiasis was found in 59 people. Age- and sex-adjusted prevalences of trichiasis in all ages in the EUs studied ranged from 0% to 0.14%; five EUs had a prevalence of trichiasis ≥0.1%.

Conclusions: There appears to be no need nor justification at this time for implementing public health measures to control trachoma in Cambodia.     

Alcohol consumption attenuates febrile responses to lipopolysaccharide and interleukin-1 beta in male rats

BACKGROUND: Chronic and acute alcohol use exert profound modulatory effects on the immune system which manifest as impaired host defense against infections. An important feature of this response is the interaction between the immune and the central nervous systems. This study investigated the effects of 14 days of alcohol exposure on cytokine-mediated neuroimmune interactions that affect the febrile component of the host-defense response. METHODS: Adult male rats were fed a liquid diet containing ethanol (EtOH, 5% w/v) for 14 days. Pair-fed and normal chow- and water-fed rats served as controls. Continuous biotelemetric recordings of body temperature and locomotor activity commencing after 14 days of EtOH feeding were used to determine the effects of chronic EtOH on the circadian pattern of temperature and activity, on the febrile response to intraperitoneal (ip) administration of lipopolysaccharide (LPS) and interleukin (IL)-1beta, and on fever induced by IL-1beta administered intracerebroventricularly. We also examined the effects of EtOH consumption on LPS-induced hypothalamic production of the pyrogenic cytokines IL-1beta and tumor necrosis factor-alpha (TNFalpha) and on the blood levels of IL-1beta, TNFalpha, IL-6, adrenocorticotropin, and corticosterone at 2, 4, and 6 hr after ip LPS. RESULTS: Fourteen days of EtOH consumption blunted the circadian increases in temperature and activity that normally occur in the dark phase of the light/dark cycle without affecting light-phase temperature or activity. EtOH consumption attenuated fever induced by LPS or IL-1beta administered ip during the light phase and significantly reduced hypothalamic production of IL-1beta. LPS-induced increases in hypothalamic TNFalpha and blood cytokines, adrenocorticotropin, and corticosterone were unaffected. Central administration of IL-1beta produced a normal febrile response in chronic-EtOH rats. CONCLUSIONS: The attenuated LPS- and IL-1beta-induced febrile responses in EtOH-consuming rats and the corresponding deficit in hypothalamic production of IL-1beta suggest that alcohol may impair IL-1beta-mediated neuroimmune communication.     

Improved perinatal health through qualified antenatal care in urban Phnom Penh,Cambodia

Objectives  The aim of this study is to examine the utilities of antenatal care with comprehensive health education qualified in Phnom Penh for the health of mothers and infants during perinatal and postpartum periods. Attention was given to the existing socioeconomic disparties among women in this urban area, and the utilities were discussed irrespective of socioeconomic status. Methods  A total of 436 pregnant women in an urban area in Phnom Penh were selected using a complete survey in randomly sampled villages and were followed up. Participating in antenatal care with comprehensive health education at least three time was regarded as the use of “qualified antenatal care” during pregnancy. In this study, we investigated the independent associations of the use of qualified antenatal care with the following outcome variables after the adjustment for the influence of socieconomic variables: postpartum maternal health knowledge, postpartum maternal anemia, low birth weight, and infant immunization. Results  Of the 314 subjects who completed the follow-up examination, 66.8% used qualified antenatal care during pregnancy. The use of qualified antenatal care was positively associated with postpartum maternal health knowledge (OR=2.38, 95% CI: 1.12–5.05). and reductions in the incidences of postpartum anemia (OR=0.22,95% CI: 0.05–0.95) and low birth weight (OR=0.05,95% CI: 0.01–0.39) after the adjustment of the influence of socioeconomic status. The infants born to mothers who used qualified antenatal care had significantly higher coverage of BCG, DPT₁, and DTP₃ immunizations (P<0.001,P<0.001, andP<0.01, respectively), independent of their socioeconomic conditions. Conclusion  This study shows the solid utilities of qualified antenatal care in Phnom Penh for perinatal health.     

Occurrence of paralytic shellfish toxins in Cambodian Mekong pufferfish Tetraodon turgidus: selective toxin accumulation in the skin.

The toxicity of two species of wild Cambodian freshwater pufferfish of the genus Tetraodon, T. turgidus and Tetraodon sp., was investigated. Tetraodon sp. was non-toxic. The toxicity of T. turgidus was localized mainly in the skin and ovary. Paralytic shellfish toxins (PSTs), comprising saxitoxin (STX) and decarbamoylsaxitoxin (dcSTX), account for approximately 85% of the total toxicity. Artificially reared specimens of the same species were non-toxic. When PST (dcSTX, 50 MU/individual) was administered intramuscularly into cultured specimens, toxins were transferred via the blood from the muscle into other body tissues, especially the skin. The majority (92.8%) of the toxin remaining in the body accumulated in the skin within 48h. When the same dosage of tetrodotoxin (TTX) was similarly administered, all specimens died within 3-4h, suggesting that this species is not resistant to TTX. Toxin analysis in the dead specimens revealed that more than half of the administered TTX remained in the muscle and a small amount was transferred into the skin. The presence of both toxic and non-toxic wild specimens in the same species indicates that PSTs of T. turgidus are derived from an exogenous origin, and are selectively transferred via the blood into the skin, where the toxins accumulate.