The effects of p-hydroxycinnamaldehyde from Alpinia galanga extracts on human chondrocytes

Osteoarthritis (OA) is the most common form of arthritis and affects millions of people worldwide. Patients have traditionally been treated with non-steroidal anti-inflammatory drugs (NSAIDs), but these are associated with significant side effects. Purification of the acetone extract of Alpinia galanga afforded p-hydroxycinnamaldehyde, as identified by nuclear magnetic resonance and mass spectrometry analyses. By exploiting the cartilage explant culture, p-hydroxycinnamaldehyde suppressed loss of uronic acid, resulting in release of hyaluronan (HA), sulfated glycosaminoglycans (s-GAGs) and matrix metalloproteinases (MMPs). p-Hydroxycinnamaldehyde and interleukin-1β (IL-1β), when incubated in primary human chondrocytes, also reduced release of HA, s-GAG and MMP-2. The results demonstrated: (a) that expression levels of the catabolic genes MMP-3 and MMP-13 were suppressed and (b) mRNA expression levels of anabolic genes of collagen II, SOX9 and aggrecan were increased. This study shows that p-hydroxycinnaldehyde from A. galanga Linn. is a potential therapeutic agent for treatment of OA.     

Gymnemopsis phuwuaensis (Apocynaceae,Asclepiadoideae), a new species from northeastern Thailand

A new species, Gymnemopsis phuwuaensis A. Kidyoo, has been discovered in northeastern Thailand and is here described and illustrated. An identification key to all species of the genus is provided. Photographs and a diagnostic comparison with the morphologically similar species G. calcicola Kerr, are also provided. Gymnemopsis phuwuaensis displays clear differences in form and color of the corolla as well as in size of bract and flower. A lectotype for Gymnemopsis pierrei is also designated.     

Interpopulation variation of a saurian malaria, Plasmodium sasai telford & ball, 1969, in three host species distributed within a range of 24° north latitude

Telford S. R., jr. 1982. Interpopulation variation of a saurian malaria. Plasmodium sasai Telford & Ball, 1969, in three host species distributed within a range of 24° north latitude. International Journal for Parasitology12: 17–22. The saurian parasite P. sasai has been found in four populations of three host species which range from Niigata Prefecture, Honshu to Bangkok, Thailand, a distance exceeding 4600 km and 24° north latitude. Variation of P. sasai within samples from the type population exceeds that found among samples from all three hosts, Takydromus tachydromoides (Honshu), T. smaragdinus (Amami Island, Ryukyus) and T. sexlineatus (Thailand). Plasmodium sasai was associated with Trypanosoma sp., Schellackia sp. and Pirhemocyton in two or more host species in ricefield-margin habitat bordered by shrub-like or heavier vegetation. This association possibly represents persistence of a host-parasite complex which evolved with an ancestral lacertid stock that later diversified into the present Takydromus species.     

Fundamental hydrochemical parameters of the Songkhram River in Northeast Thailand: foundation data for the study of an endangered tropical wetland ecosystem

The Songkhram River, the third largest tributary of the Mekong, represents an important area of wetland biodiversity associated with the Mekong River system in tropical Southeast Asia. This area is endangered by human population growth and the associated spread of commerce and industry. Nevertheless, no adequate hydrochemical data are available to act as a baseline for further limnological studies. We carried out measurements of air and water temperatures, pH, conductivity, dissolved oxygen, salinity, total dissolved solids and transparency at six sites along the length of the river from July 2005 to May 2006. The ambient temperature ranged from 24 to 40 °C with an overall average of 29.4 °C, while the average water temperature is 28.2 °C and never exceeds 35.0 °C. The pH value is within the range of 5.3–7.4 (mean 6.11). There is a trend towards increasing pH in the dry season when the water level is low. Conductivity varies spatially and temporally among study sites. There is a trend towards increasing conductivity when the water level decreases, and conversely with increasing water level. Temporal and spatial variations in dissolved oxygen show a trend that suggests an increase as the water level decreases. The total dissolved solids show no variation either temporally or spatially in the wet season but vary considerably in the dry season. These data provide a sound basis for comprehensive future studies on the ecology of the Songkhram River.     

Plio-Pleistocene giant tortoises from Tha Chang sandpits,Nakhon Ratchasima Province,Thailand

Giant tortoises have been found from the Plio-Pleistocene sediments of Tha Chang sandpits, Nakhon Ratchasima Province, Thailand. These tortoises are represented by several individuals and are described based on carapace, plastron, limb bones, and isolated plates. Three different morphotypes of epiplastral projection are recognized, pertaining to different sexes or different ontogenetic stages. Based on their large size, thick shell, single supracaudal, well-developed epiplastral projection, gulars covering anterior part of the entoplastron or in contact with the latter, and humeropectoral sulcus posterior to entoplastron, these Thai giant tortoises are assigned to the genus Megalochelys. Thai specimens show strong similarities with large tortoises from India as well as those from Flores and Timor, and are therefore very close morphologically to Melgalochelys atlas. Our study provides new evidence about polymorphism and additional information about distribution of Plio-Pleistocene fossil giant tortoises in South and Southeast Asia.     

New records of Isonychia formosana,Prosopistoma annamense and Prosopistoma sinense (Ephemeroptera) from Thailand

We describe the distribution and habitats of three new recorded mayfly species from Thailand: Isonychia formosana (Isonychidae), Prosopistoma annamense (Prosopistomatidae) and P. sinense. This is a new record from Thailand, reporting these species for the first time. A key to known larvae of Thai Prosopistoma species is provided.     

Annotated catalogue of the types of Indo-Burmese non-marine Gastropoda deposited in the Faculty of Tropical Medicine,Mahidol University,Thailand

ABSTRACT

Four decades after its publication, Rolf A.M. Brandt’s 1974 monograph on the non-marine molluscs of Thailand remains the main authority on freshwater and estuarine species for Southeast Asia and includes up to 165 new species of snails and bivalves described by Brandt and colleagues in the same book and preceding publications. All the holotypes are lodged at the Forschungsinstitut und Naturmuseum Senckenberg in Germany, and are largely inaccessible to Thai and other Southeast Asian researchers, who rely heavily on the Brandt collection as a key reference. Paratypes were, however, donated to various other collections, including some in Thailand. We present the first catalogue of 45 paratypes of gastropods of the Brandt collection, described from Thailand, Laos and Cambodia, which are lodged at the Faculty of Tropical Medicine, Mahidol University, Thailand.     

Frequent Detection of Hepatitis C Virus Subtype 3a (HCV-3a) Isolates in Thailand by PCR Using Subtype-Specific Primers

By means of a polymerase chain reaction (PCR) method using subtype-specific primers for hepatitis C virus (HCV) subtypes 1a, 1b, 2a, 2b and 3a, the prevalence of each subtype among HCV isolates in Chiang Mai, Thailand, was determined. HCV-3a appeared to be the most common subtype in blood donors, and was also frequently found in patients with liver disease. HCV-1b, but not HCV-2a or ?2b, was also commonly found in this area, while a considerable percentage of the total HCV isolates still remained unclassifiable by the above methods. Serotype analysis of the HCV isolates using C14-1 and C14-2 recombinant peptides revealed that HCV-3a was likely to carry an antigenic determinant(s) different from those of the major types 1 (HCV-1a and ?1b) and 2 (HCV-2a and ?2b).     

Cuticular lipid differences between the malaria vector and non-vector forms of the Anopheles maculatus complex

Two chromosomal forms (E and F) of the Anopheles maculatus Theobald complex were distinguished by gas-liquid chromatographic (GC) analysis of cuticular lipids in association with a multivariate principal component analysis. The GC chromatogram obtained from n-hexane extracts of individual specimens showed no consistent qualitative differences in normalized peak areas between forms. Of the seventeen consistent peaks, five were found to be quantitatively different between forms at a high (99.5-99.95%) level of statistical confidence. Relative ratios of these five quantitatively different GC peaks were used as criteria to distinguish single specimens as either form E or form F. Chemical structures of the five GC peaks were assigned by both electron impact and chemical ionization gas chromatography/mass spectrometry analysis. The first three peaks, which were always doublets, were partially resolved saturated and mono-unsaturated free fatty acids; the other two peaks were n-alkanes. Principal component analysis substantiated that the vector form E has very similar cuticular lipid profiles and is well separated from the non-vector form F.