This study evaluated the risk of single and combined exposure to microplastics in zebrafish (Danio rerio) through biomarkers, such as survival rate, excretion rate, and histological alterations of organ systems. The experimental groups were the control (Cont.), single microplastics exposure group (MPs, 1.83%/fish total weight (g)), the copper group (Cu, 21.6 μg L-1), and a group with combined exposure to MPs and copper (MPs*Cu). The experiment was conducted with individual exposure (7 days) for MP excretion rate analysis and group exposure (14 days) for biomarker analysis. The daily excretion rate of MPs tended to decrease in a time-dependent manner. The copper concentration in the body was not significantly different between single and combined copper exposure. The degeneration of mucous cells in the skin, capillary dilation of the gill lamella, increased intestinal mucous, hepatocyte hypertrophy, and the degeneration of glomeruli and renal tubules were observed in all exposure groups. These histological alterations showed the highest tendency in the MPs*Cu group. In this study, the changes in biomarkers were attributed to the single effect of copper or the combined effect of copper and MPs rather than being solely influenced by MPs.

The objective of this experiment was to determine the effect of supplementation of hot melt extrusion (HME) processed Zn sulfate on growth performance, nutrients digestibility, small intestinal morphology and excretion of Zn in weanling pigs. A total of 200 piglets of mixed sex randomly allotted to four treatments on the basis of initial BW (7.15±0.81 kg). There were five replicates in each treatment with 10 pigs per replicate. The experimental treatments consisted of: 1) basal diet containing ZnSO4; 2) basal diet containing Zn-Methionine (ZnMet); 3) basal diet containing low level of nano-Zn as HME (ZnHME50); 4) basal diet containing medium level of nano-Zn as HME ZnSO4 (Zn-HME75). The average daily gain was improved by the ZnMet and ZnHME75 compared with the pigs fed ZnSO4 supplemented diets (p=0.009). Moreover, ZnHME75 and ZnMet affected on the ATTD of CP during phase 2 (p=0.014). The villus height (VH) was affected by increasing when pigs fed diets supplemented the ZnHME75 (P=0.044). The pigs fed diets supplemented ZnHME50 had significantly the lowest (p=0.037) Zn content in liver compared with other treatments. The Zn content in the feces was significantly higher (p<0.001) in ZnSO4 and ZnMet compared with ZnHME50 or ZnHME75. In conclusion, it could be concluded that dietary Zn can be reduced by 25% with ZnHME without any detrimental effect on performance of weanling pigs.

DC-EPG 시스템을 활용하여 애멸구(Laodelphax striatellus) 암컷 성충이 벼를 섭식하는 동안 발생되는 전기적 신호를 기록하고 분석하여, 벼멸구에서 보고된 것(Seo et al., 2009)과 같은 방식으로, np, L1, L2, L3, L4-a, L4-b, L5의 7 개 EPG 파형으로 구별하였다. 파형들의 모양과 발 생 패턴은 벼멸구(Nilaparvata lugens)와 매우 유사하였고, L4-b의 직전에는 반드시 L3와 L4-a가 연속된 순서로 나타났다. 감로는 L4-b에서 주기 적으로 분비되었다. 레이저 stylectomy 후 섭식부분의 미세절편을 관찰한 결과, 애멸구 구침의 끝이 L3와 L4-a, L4-b에서는 벼의 체관부 근처 또 는 체관부에서 관찰된 반면, L5에서는 물관부에서 관찰되었다. 레이저 stylectomy로 L4-b에서 잘려진 애멸구 구침의 절단부로부터 유일하게 벼 수액이 용출되었고, HPLC로 분석된 수액 안의 당 성분으로 식물의 체관부 탄수화물 이동태인 설탕(sucrose)만이 검출되었다. 이상의 관찰 결과 와 애멸구의 EPG 파형 전개 과정 분석을 통해, L1과 L2는 관다발 도달 전에 발생하는 구침을 찌르고 타액 분비가 동반된 구침의 이동 행동으로, L3와 L4-a는 체관부에서 섭식을 위해 사전에 준비하는 과정으로, L4-b는 체관부 수액을 흡즙하는 행동으로, 마지막으로 L5는 물관부에서 형성되 는 섭식행동으로 벼멸구와 유사하게 결론지었다.

The body and head lice (Pediculus humanus humanus and Pediculus humanus capitis, respectively) are hematophagous ectoparasites of humans and only the body louse between two is known to transmit three bacterial diseases through its feces. The proliferation profiles of Bartonella quintana, the causative agent of trench fever, inside the louse body and its excretion patterns were investigated in the two louse subspecies following oral challenge with B. quintana-infected blood meal. The initial density of B. quintana was sustained inside head lice without any noticeable proliferation for the entire period after infection. In contrast, B. quintana proliferated rapidly inside body lice and the maximum density reached at 10 days post-infection. The numbers of bacteria detected in feces from infected lice were almost the same and steadily decreased over time in both body and head lice. Nevertheless, the viability of the bacteria, as determined by fluorescence, was significantly higher in body louse feces, especially at 1 day post-infection and this tendency lasted for 11 days. These findings suggest that excretion of feces containing more viable B. quintana that is proliferated inside body lice following ingestion of infected blood meal is responsible for the higher vector competence of body lice.

본 연구에서는 자바틸라피아(체장 10±1.0cm, 체중 173±4.2g)를 사용하여 염분의 변화에 따른 산소소비율, 아가미 호흡수 및 암모니아 배설률을 조사하였다. 담수(0 psu)에서 사육하던 자바틸라피아를 염분 0(대조구), 3, 9. 15, 21 및 32 psu로 이동하였을 때 시간경과에 따른 생존율을 조사하였다. 단계적 인 염분변화는 담수(0 psu, 대조구)로부터 염분을 1일 3psu씩 증가시켜 3, 9, 15, 21 및 32 p

말차, 오룡차, 홍차 및 보이차로 제조한 음료가 Cd에 중독된 SD계 흰쥐의 해독에 미치는 영향을 조사하였다. 관능검사 결과 일반 물 추출물에 비하여 색상, 향, 맛에 대한 기호도가 현저하게 향상되었으며, 종합적 기호도는 오룡차 음료가 4.18점, 홍차음료가 4.14점으로 말차음료나 보이차 음료의 점에 비하여 높았다. SD계 흰쥐를 정상군 (NC), Cd 대조군(Cd-Co), Cd투여 말차음료 15% 급여군 (Cd-Gt), Cd투여 오룡차음료 1

This study was performed to determine the effects of genetic polymorphisms, such as glutathione S-transferase μ1 (GSTM1), glutathione S-transferase θ1 (GSTT1), glutathione S-transferase π1 (GSTP1), aryl hydrocarbon N-acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), cytochrome P450 1A1 (CYP1A1) on the concentrations of urinary 1-hydroxypyrene (1-OHP) and 2-naphthol in general population with no occupational exposure to polycyclic aromatic hydrocarbons (PAHs). Study subjects were 257 men who visited a health promotion center in Busan. A questionnaire was used to obtain detailed data about age, smoking, drinking, body fat mass, intake of fat etc. Urinary 1-OHP and 2-naphthol concentration were analyzed by HPLC system with a fluorescence detector. A multiplex PCR method was used to identify the genotypes for GSTM1 and GSTT1. The polymorphisms of GSTP1, NAT2, CYP1A1 and CYP2E1 were determined by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. Urinary 1-OHP concentration was higher in deleted genotype of GSTM1, increased as smoking and alcohol drinking increased. Urinary 2-naphthol concentration was also rely on the age and smoking. Neither genetic polymorphism nor drinking-related factors were significantly related to urinary 2-naphthol concentration. No significant relation was found between physical characteristics and concentrations of urinary PAHs metabolites in the subjects, but the geometric mean of urinary 1-OHP and 2-naphthol was higher in the group with higher value compared to median value. These data suggest that in general population occupationally not exposed to PAHs, urinary concentration of PAHs metabolites is influenced by smoking, alcohol drinking and deleted genotype of GSTM1 in 1-OHP and smoking in 2-naphthol.

This study examined the extent of mammary excretion and placental transfer of bisphenol A in rats. Bisphenol A was given by simultaneous i.v. bolus injection plus infusion to steady-state at low, medium and high doses. The steady-state serum levels of bisphenol A were linearly increased with increasing the dosing rate. The systemic clearance (mean range, 119.2-154.1 ml/min/kg) remained unaltered over the dosing rate studied. The levels of bisphenol A in milk exceeded those in serum, with the steady-state milk to serum concentration ratio being 2.4-2.7. The steady-state milk levels of bisphenol A were also increased linearly with increasing the infusion rate. In a separate study, the kinetic disposition of bisphenol A in the rat maternal-fetal unit was studied in pregnant rats. After i.v. injection, bisphenol A concentration in the maternal serum declined biexponentially. Bisphenol A was rapidly distributed into placenta, fetus and amniotic fluid, with maximum concentrations in these tissues achieved within 1 hr of injection. The decline of bisphenol A in placenta, fetus and amniotic fluid paralleled that of maternal serum. A simultaneous computer simulation showed that the observed concentrations were well represented by a 5-compartmental model consisting of the maternal central, placenta, fetus, amniotic fluid, and maternal tissue compartments.