Mayuva Areekijseree

The Effects of Fulvic Acid on Copper Bioavailability to Porcine Oviductal Epithelial Cells

This study assessed the effect of dissolved organic matter on the copper (Cu) bioavailability to mammalian cells, porcine oviductal epithelial cells (POEC), in order to imply its effect onto humans. Cu toxicity was investigated in the presence of with and without fulvic acid (FA). Dissociation and exchange rate constants were calculated by using competing ligand Chelex-100, and optical parameters were employed to help explain the complexation of their aromatic and aliphatic structures. Their morphological change was observed using transmission electron microscope (TEM), and Cu species were calculated using MINTEQA2 program. The results showed that the dissociation rate constant of Cu2+–FA was equal to 9.08 × 10−4 s−1, which was slower than the exchange rate at 1.95 × 10−3 s−1. Although Cu–FA was significantly absorbed into the cells higher than Cu2+, it showed less damage than tested with Cu2+. TEM and optical studies showed many aggregations around nucleus suggesting the amphipathic character of FA helped binging to the nuclear surfaces of both Cu–FA and FA treatments. Even though the MINTEQA2 calculations showed that there was free Cu2+ in the mixed solutions around 39.2%, it could not bind with the cell surface. This suggested that the effect of FA was strong and had a lot of influence on the living surface of POEC, modifying the effect of Cu toxicity.

Characterization of red sternum syndrome in mud crab farms from Thailand

Samples of abnormal mud crabs, Scylla serrata (Forskål, 1755) (Decapoda: Portunidae), were collected from crab farms in Samutsongkhram Province, Thailand. These crabs had hard carapaces, red chelipeds and joints, pale hepatopancreas, gills, and soft muscles. They were almost immobile and finally died. The haemolymph revealed three stages of the syndrome, namely orange, orange-white, and milky-white in colors. The haemolymph, integument, hepatopancreas, gills, abdominal and claw muscle, stomach, and heart were dissected and histologically examined using transmission and scanning electron microscopy. Closer examinations found infection with rod-, curve rod-, or coccus-shape bacteria with thin and thick cell walls in all investigated organs and haemolymph. Isolation of the microorganisms from the infected tissues of red sternum syndrome crabs resulted in five types of bacteria. No microorganism growth was observed in normal crabs. Interestingly, the types of isolated bacteria can be classified according to the severity of the disease. Additionally, the degree of bacterial infection found was consistent with the stages of the disease. It was postulated that the bacteria entered the crabs via the gills, and then migrated through circulating haemocytes, before reaching the internal organs.

Effects of porcine follicle stimulating hormone, luteinizing hormone and estradiol supplementation in culture medium on ultrastructures of porcine cumulus oocyte complexes (pCOCs)

Inhibition of primary oocyte developing to secondary oocyte results from oocyte maturation inhibitor (OMI) which is secreted from oocyte-surrounding cumulus cells (CCs) during forming complexes with an oocyte. Development of primary oocyte occurs when the CCs are dissociated from the oocyte. This research studied the effects of pFSH, LH, and estradiol supplementation in culture medium on ultrastructures of porcine cumulus oocyte complexes (pCOCs) using transmission electron microcopy (TEM) and inverted microscopy. A total of 880 oocytes were isolated from 110 ovaries: an average of 8 oocytes per ovary. The oocytes were round in shape and surrounded by zona pellucida with layers of cumulus cells (CCs), at a diameter ranging between 90 and 150 μm and more than 400 μm. Based on the CCs surrounding an oocyte, pCOCs were classified into 5 types, which were intact-, multi-, partial cumulus cell layers, completely denuded oocyte, and expanded cumulus cell layer, which were found at the percentage of 53.86%, 14.32%, 4.32%, 19.20%, and 8.30%, respectively. The Types I and II pCOCs (intact- and multi-CCs layers) were further cultured at 37°C with 5% CO(2), 95% air atmosphere, and high humidity for 24-48 h to investigate their morphological changes after hormonal induction. For the pCOCs cultured without hormonal induction, the CCs were still round in shape and remained in contact with an oocyte via a process of granular end point sticking into the zona pellucida. In contrast, for the hormone supplemented groups, morphological alteration of pCOCs were seen after culture of 24-48 h. The CCs shape was changed from round into elongated or columnar in an opposite direction from an oocyte as well as no communication between microvilli of CCs observed. This led into ceasing of OMI secretion. Therefore, changes of CCs morphology were a sign of the beginning of oocyte maturation. Further study is to characterize the granular substance at the end point of CCs that stick into the zona pellucida.

In vitro toxicology assessment of cadmium bioavailability on primary porcine oviductal epithelial cells

This study assessed the in vitro effects of cadmium ion (Cd(2+)) and cadmium-fulvic acid complexes (Cd(2+)-FA) on porcine oviductal epithelial cells (POEC) using transmission electron microscopy (TEM). Fresh POEC were cultured for 24h and then exposed for 3h in the tested solutions. Absorbed cadmium was analyzed by graphite furnace atomic absorption spectrophotometer (AAS). Dissociation and exchange rate constants were determined using the competing ligand, Chelex-100 and predicted cadmium species were calculated using the MINTEQA2 program. The results showed that the dissociation rate constant of Cd(2+)-FA was equal to 1.023×10(-3)s(-1) which was slower than the exchange rate at 2.062×10(-3)s(-1). Nevertheless, the absorbed concentrations of Cd(2+) and Cd(2+)-FA of POEC were similar and were 47±6.25μgL(-1) and 54±3.61μgL(-1), respectively. Although both levels of absorptions were not significantly different (t-test p=0.168 at α 0.01), their morphological effects as examined by TEM were substantially different with the effects being most marked with Cd(2+)>Cd(2+)-FA>FA. Aggregations around nuclei and nuclear membranes were observed with FA treatment whilst Cd(2+)-FA treatment produced more cytoplasmic damage. Cd(2+) treatment caused nuclear deformities. In conclusion, FA appears to penetrate the cells but was less likely to enter the nucleus. It also reduced the toxicity of Cd(2+) as the nuclei from the Cd(2+)-FA treatment appeared normal. Nevertheless, some Cd(2+) could still enter the nucleus. This might be because there was still 67.8% Cd(2+) left unbound from the Cd(2+)-FA treatment as calculated from the MINTEQA2 program compared to 99.1% Cd(2+) with Cd(2+) treatment, thus underlining the inherent toxicity of soluble cadmium ion.