Hatchery-reared F2 Mekong giant catfish spent their time above hypoxic water in the Mae Peum reservoir, Thailand

March 5-6, 2009, Bangkok, ThailandJuvenile and young hatchery-reared Mekong giant catfish Pangasianodon gigas have been released into reservoirs throughout Thailand. For the sustainable reservoir fishery of the giant catfish, new science-based fishery management measures are expected in Thailand, such as the establishment of protected areas. Therefore, the habitat use and movement patterns of the hatchery-reared giant catfish have been investigated in the Mae Peum reservoir from 2003 to 2005. Our results suggest that the hatchery-reared fish spent their time in shallow depths above hypoxic water in the reservoir. The fish which have been reared in a fish pond may recognize and avoid hypoxic conditions

Decreased ADP-Ribosyl Cyclase Activity in Peripheral Blood Mononuclear Cells from Diabetic Patients with Nephropathy

Aims/hypothesis. ADP-ribosyl-cyclase activity (ADPRCA) of CD38 and other ectoenzymes mainly generate cyclic adenosine 5’diphosphate-(ADP-) ribose (cADPR) as a second messenger in various mammalian cells, including pancreatic beta cells and peripheral blood mononuclear cells (PBMCs). Since PBMCs contribute to the pathogenesis of diabetic nephropathy, ADPRCA of PBMCs could serve as a clinical prognostic marker for diabetic nephropathy. This study aimed to investigate the connection between ADPRCA in PBMCs and diabetic complications. Methods. PBMCs from 60 diabetic patients (10 for type 1 and 50 for type 2) and 15 nondiabetic controls were fluorometrically measured for ADPRCA based on the conversion of nicotinamide guanine dinucleotide (NGD+) into cyclic GDP-ribose. Results. ADPRCA negatively correlated with the level of HbA1c (P = .040, R2 = .073), although ADPRCA showed no significant correlation with gender, age, BMI, blood pressure, level of fasting plasma glucose and lipid levels, as well as type, duration, or medication of diabetes. Interestingly, patients with nephropathy, but not other complications, presented significantly lower ADPRCA than those without nephropathy (P = .0198) and diabetes (P = .0332). ANCOVA analysis adjusted for HbA1c showed no significant correlation between ADPRCA and nephropathy. However, logistic regression analyses revealed that determinants for nephropathy were systolic blood pressure and ADPRCA, not HbA1c. Conclusion/interpretation. Decreased ADPRCA significantly correlated with diabetic nephropathy. ADPRCA in PBMCs would be an important marker associated with diabetic nephropathy

Impact of serum retinol-binding protein 4 levels on regulation of remnant-like particles triglyceride in type 2 diabetes mellitus

Background. Although retinol-binding protein 4 (RBP4) associates with insulin resistance and remnant-like particles triglyceride (RLP-TG) elevated in the insulin resistant state, few data exist regarding the relationship between RBP4 and RLP-TG. Subjects and Methods. The study included 92 Japanese type 2 diabetic mellitus (T2DM) male patients (age 60.5 ± 13.6 years, body mass index (BMI) 24.7 ± 4.1 kg/m2, waist circumference (WC) 88.4 ± 10.7 cm, and HbA1c (NGSP) 7.2 ± 1.9 %). Patients on medications affecting insulin sensitivity, including fibrates, biguanides, and thiazolidinedione, were excluded. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by computed tomography. Results. RBP4 levels showed a significant positive correlation with RLP-TG (r = 0.2544 and P = 0.0056), TG (r = 0.1852 and P = 0.041), RLP-TG/TG (r = 0.23765 and P = 0.0241), and age (r = - 0.2082 and P = 0.0219), although there was no significant correlation with VFA, SFA, adiponectin levels, or homeostasis model of assessment insulin resistance (HOMA-R). Multiple regression analysis revealed that RBP4 was an independent determinant of RLP-TG (P = 0.0193) but was not a determinant of TG. Conclusions. RBP4 correlates positively with serum RLP-TG independent of fat accumulation in T2DM. RBP4 may regulate remnant metabolism independent of glycemic control in T2DM. © 2013 Naoto Yamaaki et al

Clinical Study Impact of Serum Retinol-Binding Protein 4 Levels on Regulation of Remnant-Like Particles Triglyceride in Type 2 Diabetes Mellitus

Background. Although retinol-binding protein 4 (RBP4) associates with insulin resistance and remnant-like particles triglyceride (RLP-TG) elevated in the insulin resistant state, few data exist regarding the relationship between RBP4 and RLP-TG. Subjects and Methods. The study included 92 Japanese type 2 diabetic mellitus (T2DM) male patients (age 60.5 ± 13.6 years, body mass index (BMI) 24.7±4.1 kg/m 2 , waist circumference (WC) 88.4±10.7 cm, and HbA1c (NGSP) 7.2±1.9%). Patients on medications affecting insulin sensitivity, including fibrates, biguanides, and thiazolidinedione, were excluded. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by computed tomography. Results. RBP4 levels showed a significant positive correlation with RLP-TG ( = 0.2544 and = 0.0056), TG ( = 0.1852 and = 0.041), RLP-TG/TG ( = 0.23765 and = 0.0241), and age ( = −0.2082 and = 0.0219), although there was no significant correlation with VFA, SFA, adiponectin levels, or homeostasis model of assessment insulin resistance (HOMA-R). Multiple regression analysis revealed that RBP4 was an independent determinant of RLP-TG ( = 0.0193) but was not a determinant of TG. Conclusions. RBP4 correlates positively with serum RLP-TG independent of fat accumulation in T2DM. RBP4 may regulate remnant metabolism independent of glycemic control in T2DM

Study on feeding habits of Mekong giant catfish in Mae peum Reservoir, Thailand

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-15, 2004, Imperial Tara Hotel, Bangkok, ThailandIn order to recapture Mekong giant catfish, we developed an automatic fish recapture system (AFR system). The AFR system causes the free-ranging fish to float at the scheduled time. We have conducted experiments on Mekong giant catfish in the Mae peum reservoir, Thailand. We used 7 cultivated young catfish, whose total length ranged from 76.5 cm to 86.5 cm. After we attached the AFR system to the catfish, we released them into the reservoir in August (one catfish), October (three catfish) and December (three catfish) of 2004. The AFR systems were scheduled to cause the catfish to float after four to eight days. The recovery percentage of both the catfish and the AFR systems was 43 %. The recovery percentage of only the AFR systems was 29 %. The percentage of loss of all the catfish and the AFR systems was 29 %. We also examined the stomach contents of the catfish with a microscope and found some zooplankton and phytoplankton. The total number of the zooplankton in the stomach contents in October was 1288 individuals and the most, and those in August and December were 33 and 34 individuals respectively and least

Vertical Movements of a Mekong Giant Catfish (Pangasianodon gigas) in Mae Peum Reservoir, Northern Thailand, Monitored by a Multi-Sensor Micro Data Logger

The vertical movements of one Mekong giant catfish Pangasianodon gigas were monitored for 3 days in August 2004 using a depth-temperature micro data logger. The logger was recovered using an innovative time-scheduled release system and located by searching for VHF radio signals. The logger was found approximately 2.2 km away from the release point and provided (n=705,128) depth and temperature data collected over a period of 98 hours following the release. The fish spent more than 99% of its time at less than 3 m below the surface. The maximum swimming depth was 5.6 m. No sharp thermocline was present during the experiment. Temperature did not have any detectable effect on the pattern of vertical movement of the fish. The dissolved oxygen concentration (DO) was stratified, with a concentration of >60% saturation in the first 3 m below the surface falling to 10% saturation at depths lower than 4 m. This specific DO stratification was found to limit the vertical movement of the catfish

A review of the Mekong giant catfish tracking project (MCTP) from 2002 to 2004

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-14, 2005, Siam City Hotel, Bangkok, ThailandFor the conservation and successful stock enhancement of the endangered species Mekong giant catfish Pangasianodon gigas, an understanding of its movement patterns and behavior is indispensable. The Mekong giant catfish tracking project (MCTP) has been begun to measure the movements of hatchery-reared Mekong giant catfish using acoustic telemetry and bio-logging technology in the Mae peum reservoir and Mekong River. Research in the Mae peum reservoir demonstrated that fish showed distinctive diel vertical movement and the swimming depth was limited by the thermocline or dissolved oxygen stratification. Fish also displayed diel horizontal movement between inshore at night and offshore areas during the day. Researchers in the Mekong River presented the first records of upstream and downstream movement of Mekong giant catfish for up to 97 days. Fish swam upstream at a speed of 16.2 km d-1 and downstream at a speed of 7.2 km d-1 during a day. These results will contribute to plans for the species conservation and the effective stock enhancement in reservoirs and fish ponds

Feeding habits of hatchery-reared young Mekong giant catfish in a fish pond and in Mae peum reservoir

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-14, 2005, Siam City Hotel, Bangkok, ThailandWe studied the feeding habits of the hatchery-reared young Mekong giant catfish released in a fish pond and Mae peum reservoir, northern Thailand. We examined the gut (stomach and intestine) contents of 5 catfish, Relative Length of Gut (RLG) of 4 catfish and plankton composition in the reservoir. The gut contents of the catfish in the fish pond consisted of a fluid like the pellets, zooplankton, phytoplankton and aquatic plants. The gut contents in the reservoir consisted of unspecified contents, zooplankton and phytoplankton. The majority of prey items were the Branchiopoda (75 % in zooplankton) and Chlorophyceae (98 % in phytoplankton) in the gut contents of the catfish in the reservoir, while the major plankton in the reservoir were copepoda including nauplius and copepodid (mean : 50 %) and eurotatorea (mean : 41 %) in zooplankton, and chrysophyceae (mean : 52 %) and chlorophyceae (mean : 38 %) in phytoplankton. It is reasonable to suppose that the catfish positively selected their major prey items if a particular prey item was found in the gut contents, contrary to the organism composition in the reservoir. However, the cuticle and the cell walls of these plankton are resistant to intestine enzymes of some fish. Furthermore, RLG of 4 catfish were greater than 1. In general, a fish is carnivorous when RLG is less than 1, while the fish is herbivorous or omnivorous when RLG is greater than 1. These results indicate that the hatchery-reared young catfish fed on the potential prey items in front of the catfish, and the catfish might not be piscivorous but planktivorous