Pannee Pakkong

Organic and inorganic compound variations in haemolymph, epidermal tissue and cuticle over the molt cycle in Scylla serrata (Decapoda)

Analysis of organic and inorganic compounds in haemolymph, epidermal tissue and cuticle, allowed the correlation of their content variation during the molt cycle in Scylla serrata (Decapoda). The extrusion of carbohydrate, chitin, H(2)O- and NaOH-soluble proteins of the epidermal tissue from D2 stage on suggested an early formation of the organic fraction in the new cuticle. The additional secretion of HCl-soluble protein, glycosaminoglycans, calcium, phosphorus and sulfur in D2-D3 stages suggests mineral nucleation shortly before or at ecdysis. This is consistent with the dominant content of proteins and chitin associated with peaks of carbohydrates and GAG-sulfur groups detected in the cuticle immediately after ecdysis. Furthermore, the maximal phosphorus content at this moment suggests calcium, magnesium and manganese phosphate deposits. After an intense accumulation of calcium, chitin and sharp decrease of protein from A to B stages, a constant rate of their deposition in intermolt and dissolution in premolt occurred. The variations concerning proteins, carbohydrates, glycosaminoglycans, calcium, magnesium and sulfur in the haemolymph, before and after ecdysis, suggest a transitory phenomenon for calcium binding and releasing. Other major elements such as, sodium, potassium and chloride may function as osmotic regulators in the haemolymph and in epidermal compartments. The copper profile presented an indicator role for variations of osmolality over the molt cycle.

Study of a suitable fish plasma for in vitro culture of glochidia Hyriopsis myersiana

Several organic and inorganic sources from the plasma of different fish species and horse serum were utilized as additives to the artificial culture M199 medium to improve glochidial survival and transformation of Hyriopsis myersiana. After 2–3 days of culturing in the medium containing plasma of Nile tilapia or hybrid catfish, striped catfish or horse serum, the glochidia presented significantly (P<0.05) lower percentage survival compared to medium containing common carp plasma. The highest (93.77±3.0) and lowest (32.42±5.85) percentage survival rates of glochidia were found with common carp and striped catfish plasma, respectively. After 10 days, relevant signs of glochidia transformation, such as the foot and mantle edge, were observed. In all assays, the glochidia transformation reached 100% most probably due to the exchange of the medium at the fifth day and the addition of 1 ml of distilled water at the ninth day of culturing. The intense mobility of juveniles in the medium containing the common carp plasma indicated excellent culture conditions. The ideal density for this plasma corresponded to 150–200 glochidia per culture dish. The present results suggest that M119 medium complemented with the common carp plasma and the medium exchange during culturing period may constitute a functional process to prepare an in vitro culture for freshwater mussels, particularly H. myersiana. The most relevant amino acids for a successful development are CIT, GLX, LEU, PRO, THR and ALA particularly with the contents in the common carp plasma.

Adsorption, desorption and degradation of α‐endosulfan in tropical soils of Thailand

Abstract The adsorption, desorption, and degradation of endosulfan (1,2,3,4,7,7‐hexachlorobicyclo[2,2,l]‐2‐heptene‐5,6‐bisoxymethylene sulfite) in two major tropical soils from Thailand were studied. Each soil‐type, Rangsit lowland soils (Rangsit series) and Phrabat upland soils (Pakchong series), were sub‐divided into surface or plow layer, 0–20 cm depth, and subsoils, 20–40 cm depth. Adsorption was determined using 24 h batch equilibrium, with five different concentrations of 14C labelled endosulfan ranging from 1.04 to 16.64 ng/mg soils. Adsorption coefficient values (Kads) as by Freundlichs model ranged from 0.02 to 0.20. Higher adsorption coefficients were measured in Rangsit soils as compared to Phrabat soils. Desorption as attributed to hysteresis was also measured. Desorption coefficient values (Kjes) were higher than adsorption (Kads) in each study. Degradation of endosulfan was through microbial process. Little abiotic degradation was measured in sterile soil sample. Measured degradation rates ...

Evaluation of Effect of Triterpenes and Limonoids on Cell Growth, Cell Cycle and Apoptosis in Human Tumor Cell Lines

Six triterpenes and eight limonoids were evaluated for their capacity to inhibit the growth of three human tumour cell lines, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and melanoma (A375-C5). The mechanisms involved in the observed cell growth arrest of the four most potent compounds were carried out by studying their effect in cell cycle profile and programmed cell death. The results showed that one triterpene (odoratol) and two limonoids (gedunin and cedrelone) caused cell cycle arrest while only the limonoids gedunin and cedrelone were found to be very potent inducers of apoptosis.

Students on the plasma composition of fish hosts of the freshwater mussel, Hyriopsis myersiana, with implications for improvement of the medium for culture of glochidia

Summary Analyses of several organic and inorganic elements in the plasma of different fish species in control and infested conditions with the freshwater mussel Hyriopsis (Limnoscapha) myersiana (Lea, 1856) were undertaken. The most suitable composition of plasma corresponded to the fish species which produced the highest number of transformed glochidia. The infestation assay showed that glochidia of H. myersiana had a short transformation period of 6–12 days to reach the juvenile stage. The highest recovery peak could be seen in the plasma of the common carp, with lower peaks in the nile tilapia, hybrid catfish and striped catfish. The significant increase at days 3 (P<0.05) and 6 (P3<0.01) in the free amino acids Pps, Pea, Hcy2, Cys2, Orn, Abu and Leu in plasma also seems to be related to the transformation success of glochidia. The significant decrease during both days (P<0.05 and P<0.01) in amino acids Mhis 1, Etn, Arg, Tau, Ser, Lys and potassium, magnesium and chloride in the plasma suggests an involvement with the glochidia encystment process. Conversely, the significant increase at day 12 (0.05 >P<0.0l) in Sar, Ala, tryglicerides, glucose and calcium may be related to juvenile release from the cyst. Thus, while the amino acid content of Cit, Glx, Leu, Pro, Thr and Ala in normal fish plasma influences cultured glochidia survival and transformation, an increase in concentration of the Pps-Leu group and Aad influences glochidia survival of H. myersiana during infestation. The observations suggest that a mixture of both amino acid groups in the culture medium may provide appropriate physiological conditions for H. myersiana that facilitate their transformation and survival into the early juvenile stage.

Occupational Health Risks Among Trichloroethylene-Exposed Workers in a Clock Manufacturing Factory

Trichloroethylene (TCE) is an important volatile organic compound once widely used in industry throughout the world. Occupational exposure to TCE can cause a number of health hazards such as allergic reactions and genetic damage. The purpose of this study was to evaluate occupational exposure to TCE, by analysis of the air in the breathing zone and of urine from workers employed in a clock manufacturing factory. A subjective symptom survey was conducted by using a self-administered questionnaire to evaluate the health hazards. Micronucleus (MN) frequency, based on the cytokinesis-block micronucleus assay (CBMN) in peripheral blood lymphocytes, (PBLs) was used as a biomarker for chromosome damage. A total of 244 participants, including 171 workers occupationally exposed to TCE and 73 non-exposed control employees, working mainly in office jobs in the same factory, were enrolled in this study. Analyses of airborne TCE concentrations in the workplace, and of urinary trichloroacetic acid (TCA) of the workers and controls, were performed by Gas Chromatography-Electron Capture Detector (GC-ECD) using the modified headspace technique. The average concentration of TCE in the workplace breathing zone was 27.83 ± 6.02 ppm. The average level of urinary TCA of the exposed workers and controls was 14.84 ± 1.62, 2.95 ± 0.28 mg/L. The frequency of MN/1000BN was 7.029 ± 0.39, significantly higher than for those in the control group (3.57 ± 0.31, p = 0.001). According to multiple linear regression analysis, the results indicated that urinary TCA levels correlated with the increased MN in exposed workers (r = 0.285, p < 0.001). The prevalence rate of subjective symptoms in the exposed group was 9.61-11.76 times higher than the rate of the non-exposed group (p < 0.001). It was found that skin (29.6%) and respiratory symptoms (21.1%) were the most frequent among the exposed workers. In conclusion, these results indicate that increased micronucleus frequency is associated with occupational trichloroethylene exposure. The use of TCE in the factory is threatening workers’ health.

Screening a Small Library of Xanthones for Antitumor Activity and Identification of a Hit Compound which Induces Apoptosis

Our previous work has described a library of thioxanthones designed to have dual activity as P-glycoprotein modulators and antitumor agents. Some of these compounds had shown a significant cell growth inhibitory activity towards leukemia cell lines, without affecting the growth of non-tumor human fibroblasts. However, their effect in cell lines derived from solid tumors has not been previously studied. The present work aimed at: (i) screening this small series of compounds from an in-house library, for their in vitro cell growth inhibitory activity in human tumor cell lines derived from solid tumors; and (ii) initiate a study of the effect of the most potent compound on apoptosis. The tumor cell growth inhibitory effect of 27 compounds was first analysed in different human tumor cell lines, allowing the identification of a hit compound, TXA1. Its hydrochloride salt TXA1·HCl was then synthesized, to improve solubility and bioavailability. Both TXA1 and TXA1·HCl inhibited the growth of MCF-7, NCI-H460, A375-C5, HeLa, 786-O, Caki-2 and AGS cell lines. The effect of TXA1·HCl in MCF-7 cells was found to be irreversible and was associated, at least in part, with an increase in cellular apoptosis.

Structure Based Design, Synthesis, and Evaluation of Potential Inhibitors of Steroid Sulfatase

The activity of the enzyme steroid sulfatase (STS) is high in breast tumors and elevated levels of STS mRNA expression have been associated with a poor prognosis. Potent STS irreversible inhibitors have been developed, paving the way to use this new type of therapy for the treatment of breast cancer. Several small molecules belonging to a natural products-inspired library of previously obtained inhibitors of tumor cell growth and new molecules planned to be reversible inhibitors of this enzyme were docked into STS. Some of the synthesized xanthone derivatives, which revealed high scores against STS, namely oxo-9H-xanthene-3,6-diyl bis(3-chlorobenzoate) (5), 9-oxo-9H-xanthene-3,6-diyl bis(4-tertbutylbenzoate) (6) and 9-oxo-9H-xanthene-3,6-diyl bis(4-methoxybenzoate) (7) showed poor water solubility. Therefore, formulations of these derivatives with cyclodextrins were prepared and characterized. The compounds were evaluated regarding their effect on the in vitro growth of various human tumor cell lines, as well as the effect in STS inhibition, for the compounds with the most favorable ΔG values. Additionally, the capacity of these derivatives and of some prenyl and acetoxy-benzophenone and xanthones to inhibit the in vitro growth of MCF-7 ER(+) and/or to inhibit STS in a micromolar range was also assessed. Some compounds developed in the present work were shown to be potential STS inhibitors.

Adsorption‐desorption hysteresis of α‐endosulfan in tropical soils using isotopic techniques

This study was designed to evaluate the adsorption‐desorption hysteresis of endosulfan (1,2,3,4, 7,7‐hexachlorobicyclo[2,2,1]‐2‐heptene‐5,6‐bisoxymethylene sulfite) in selected tropical soils. Two major tropical soils from Thailand were selected, Rangsit lowland soils (Rangsit series) and Phrabat upland soils (Pakchong series). The soil types were sub‐divided into plow soils, 0–20cm depth from the surface, and subsoils, 20–40cm depth. Adsorption was determined in 24h batch equilibrium, with five different concentrations of 14C endosulfan ranging from 1.04 to 16.64 ng/mg soils. Four successive desorption studies were performed continuously after three adsorption concentrations, 24h for each successive. Adsorption coefficient values (K ads) as determined by Freundlich model ranged from 0.02 to 0.14 and found to be higher in Rangsit soils as expected when compared with Phrabat soils. Desorption was hysteresis in every desorption study. Desorption coefficient values (K des) were higher than adsorption (K des).