Difference Analysis on Contents of Gallic Acid and Catechins of Tea Resources from Yunnan Province

[Objective] This study aimed to analyze the difference in the contents of gallic acid and catechins of tea resources from Yunnan Province. [Method] By using high performance liquid chromatography （HPLC）, the contents of gallic acid （GA）, catechins （C）, epicatechin （EC）, epigallocatechin （EGC）, epicatechin gallate （ECG） and epigallocatechin gallate （EGCG） of 121 tea germplasms from the China National Germplasm Tea Repositories （CNGTR） at the Tea Research Institute of Yunnan Academy of Agricultural Sciences （TRIYAAS） were measured. [Result] The content of GA ranged from 0.210% to 1.902%, with an average of 0.834%, explaining rela- tively low GA content among tea germplasms. The content of C ranged from 0.069% to 8.865%, with an average of 1.916%. The content of EC ranged from 0.126% to 2.865%, with an average of 1.112%. The content of EGC ranged from 0.00% to 3.709%, with an average of 0.954%. The content of ECG ranged from 0.739% to 8.957%, with an average of 4.063%. The content of EGCG ranged from 0.819% to 11.77%, with an average of 5.939%. The content of total C ranged from 6.354% to 22.654%, with an average of 14.042%. [Conclusion] There was relatively big difference of catechin contents among different tea resources, indicating that there was plentiful biodiversity of Yunnan tea germplasms. At the same time, three tea germplasms with high epigallocatechin gallate content （≥10%） was selected preliminarily, which would provide important materials for breeding tea cultivars with high EGCG content in the future.

Is the Potential Interconnection between Antibiotic Susceptibility and Disinfectant Resistance a Threat to Food Safety?

The prevalence of antibiotic susceptibility and disinfectant resistance in bacterial pathogens causes a serious problem not only to food safety but also to public health, which directly or indirectly leads to treatment and disinfection failures. In this review, multidrug resistance, the mechanism of disinfectant resistance, the methods for detecting disinfectant resistance and the cross-resistance between an- tibiotics and disinfectants are summarized. More efforts should be devoted to explor- ing the professional guidance of using antibiotics and disinfectants, and to develop- ing the comprehensive detection with genetic and molecular methods is highly ex- pected.

Esophageal ulceration complicating doxycycline therapy

AIM;TO report present state of iatrogenic drug-induced esophageal injury(DIEI)induced by medications in a private clinic. METHODS:Iatrogenic drug-induced esophageal injury (DIEI)induced by medications has been more frequently reported.In a private clinic we encountered 36 cases of esophageal ulcerations complicating doxycycline therapy in a mainly younger Saudi population(median age 29 years). RESULTS:The most frequent presenting symptoms were odynophagia,retrosternal burning pain and dysphagia(94 %, 75 % and 56 %,respectively).The diagnosis was according to medical history and confirmed by endoscopy in all patients. Beside withdrawal of doxycycline,when feasible,all patients were treated with a proton-pump inhibitor(PPI)and a prokinetic.Thirty patients who reported to the clinic after treatment were improved within 1-7(median 1.7)days. CONCLUSION:Esophageal ulceration has to be suspected in younger patients with odynophagia,retrosternal burning pain and/or dysphagia during the treatment with doxycycline.

Estrogen,male dominance and esophageal adenocarcinoma:Is there a link?

Esophageal adenocarcinoma is a cancer with poor prognosis, and its incidence has risen sharply over recent decades. Obesity is a major risk factor for developing this cancer and there is a clear male gender bias in the incidence that cannot be fully explained by known risk factors. It is possible that a difference in the expression of estrogen, or its signaling axes, may contribute to this gender bias. We undertook a com- prehensive literature search and analyzed the available data regarding estrogen and estrogen receptor expres- sion, and the possible sex-specific links with esopha- geal adenocarcinoma development. Potentially relevant associations between visceral vs subcutaneous fat deposition and estrogen expression, and the effect of crosstalk between estrogen and leptin signaling were identified. We also found limited studies suggesting a role for estrogen receptor 13 expression in esophageal adenocarcinoma development. The current literature supports speculation on an etiological role for estrogen in the male gender bias in esophageal adenocarcino- ma, but further studies are required.

Expression of human chorionic gonadotropin, CD44v6 and CD44v4/5 in esophageal squamous cell carcinoma

AIM： To study the relationship between the expression of human chorionic gonadotropin （HCG）, CD44v6, CD44v4/5 and the infiltration, metastasis of esophageal squamous cell carcinoma. METHODS： By labeled streptavidin-biotin technique, the expressions of HCG, CD44v6, and CD44v4/5 in 42 patients with esophageal squamous cell carcinoma were examined. RESULTS： The positive rate of HCG expression in patients with lymph node metastasis was 85.71% （18/21）, higher than that （57.14%, 12/21） in those without lymph node metastasis （P〈0.05）. The positive rate of CD44v6 expression was 71.43% （15/21） in lymph node metastasis group, and 38.09% （8/21） in nonmetastasis group; there was a significant difference between the two groups （P〈0.05）. The positive rate of CD44v4/5 expression was 76.19% （16/21） in lymph node metastasis group, and 42.86% （9/21） in non-metastasis group; there was also a significant difference between them （P〈0.05）. From grade Ⅰ to grade Ⅲ in differentiation, the positive rate of HCG expression was 84.62% （11/13）, 70.59% （12/17） and 58.33% （7/12）, respectively, there was no significant difference among them （P〉0.05）. The positive rate of CD44v6 expression in grades Ⅰ-Ⅲ of cancer tissues was 76.92% （10/13）, 52.94% （9/17）, and 33.33% （4/12） respectively; there was no significant difference among them. The positive rate of CD44v4/5 expression in grades Ⅰ-Ⅲ of cancer tissues was 69.23% （9/13）, 64.71% （11/17）, and 41.67% （5/12） respectively; there was no significant difference among the three groups. There was no correlation between the positive rates of HCG and CD44v6, CD44v4/5 expression. Cancer cells in carcinomatous emboli and those infiltrating into vascular wall strongly expressed HCG, CD44v6, and CD44v4/5. CONCLUSION： Expression of HCG, CD44v6, and CD44v4/5 in esophageal squamous cell carcinoma is related to its infiltration and metastasis. HCG, CD44v6, and CD44v4/5 have different effects on the infiltration and metastasis of esophageal squamous cell carcinoma.

Physiological characteristics and commercial application of edible mushroom dietary fiber

Edible mushrooms are considered as healthy food because they are low in calories and fat but rich in proteins minerals and dietary fiber(DF). Edible mushrooms are recognized as new potential resource of DF since the components of edible mushroom dietary fiber(EMDF) have shown special physiological and pharmacological effects on human and animals. In this article,the soluble and insoluble fractions of DF in different edible mushroom species have been evaluated. Biological effects of EMDF are related to promoting desired responses,for example,reducing blood cholesterol,protecting cells from free radicals attack by antioxidative effects,attenuating levels and fluctuations of blood glucose and selectively supporting the growth of beneficial gut bacteria. The EMDF plays an important role in reducing risk of cardiovascular diseases,diabetes mellitus and intestinal diseases. The non-starch polysaccharides(NSP),a kind of EMDF,is the best known and most potent mushroom-derived substances with antitumor and immunomodulatory properties. EMDF has also been reported to take part in the control of body weight,lipid homeostasis and insulin sensitivity due to its effect on specific chemical structures and physical properties. Many pharmaceutical substances with potent and unique health- enhancing properties were isolated recently from edible mushrooms and distributed worldwide. Mushroom-based dietary supplements(DSs) with potential therapeutic effects are produced from the mycelia or the fruiting bodies of mushrooms,and are consumed in the forms of capsules,tablets,or extracts. The EMDF, based on its special physiological functions on human health,shows a wide range of potential application prospects.

Amelanotic malignant melanoma of the esophagus:Report of two cases with immunohistochemical and molecular genetic study of KIT and PDGFRA

The author reports herein two cases of amelanotic malignant melanoma of the esophagus. Case 1 is an 87-year-old woman who was admitted to our hospital because of nausea and vomiting. Endoscopic examination revealed an ulcerated tumor of the distal esophagus, and a biopsy was taken. The biopsy showed malignant polygonal and spindle cells. No melanin pigment was recognized. Immunohistochemically, the tumor cells were positive for melanosome （HMB45）, S100 protein, KIT and Platelet derived growth factor receptor-α （PDG- FRA）. The patient was treated by chemotherapy and radiation, but died of systemic metastasis 12 mo after the presentation. Case 2 is a 56-year-old man presenting with dysphagia. Endoscopic examination revealed a polypoid tumor in the middle esophagus, and a biopsy was obtained. The biopsy showed malignant spindle cells without melanin pigment. Immunohistochemically, the tumor cells were positively labeled for melanosome,S100 protein, KIT and PDGFRA. The patient refused operation, and was treated by palliative chemotherapy and radiation. He died of metastasis 7 mo aEer the admission. In both cases, molecular genetic analyses of gene （exons 9, 11, 13 and 17） and PDGFRA gene （exons 12 and 18） were performed by the PCR direct sequencing method, which showed no mutations of KIT and PDGFRA genes. This is the first report of esophageal malignant melanoma with an examination of the expression of KIT and PDGFRA and the mutational status of K/T and PDGFRA genes.

Primary malignant melanoma of the esophagus

Primary malignant melanoma of the esophagus （PMME） is an extremely rare and aggressive tumor, comprising less than 0.2% of all primary esophageal neoplasms. There are fewer than 270 reported cases in worldwide literature, most of which are scattered cases reported. This tumor has usually been reported as a pedunculated, polypoid tasion in the middle and lower third of the esophagus. Hematogenic and lymphogenic metastases are commonly reported for PMME cases. Although surgical resection has been considered as the best possible option, the prognosis has been nonetheless poor, even combined with adjuvant chemotherapy postoperatively, according to the literatures. Here we reported such a case on its clinical presentations and treatment.

Glutathione-S-transferase M1 polymorphisms on the susceptibility to esophageal cancer among three Chinese minorities:Kazakh,Tajik and Uygur

AIM： To investigate the glutathione-S-transferase M1 （GSTM1） polymorphisms in three Chinese minorities, Kazakh, Uygur, and Tajik; and the pathological significance of GSTM1 polymorphisms in esophageal carcinogenesis in Kazakh.METHODS： A total of 1121 blood samples （442 males and 679 females） were obtained from healthy Kazakh （654）, Uygur （412） and Tajik （55）. Primary esophageal squamous cell cancer （ESCC） tissues from Kazakh were obtained from 116 patients who underwent surgery. GSTM1 polymorphisms were analyzed by a combined approach of PCR and electrophoresis techniques.RESULTS： GSTM1 null genotype was found in 62.63% Uygur, 50.91% Tajik and 47.40% Kazakh. A significantly higher frequency of GSTM1 null genotype in Uygur was observed compared with Kazakh （OR： 1.859, 95% CI： 1.445 -2.391, χ^2 = 23.71, P = 0.000）. In addition, GSTM1 null genotype was found in 23.53% of welldifferentiated ESCC in Kazakh, in 49.23% of poorly differentiated ESCC, with a significant difference （OR： 3.152, 95% CI： 1.403-7.080, χ^2 = 8.018, P = 0.007）.CONCLUSION： There is a marked difference in the frequency of common GSTM1 null genotype between Uygur and Kazakh. GSTM1 null genotype is associated with differentiation of ESCC in Kazakh.

Metabolic syndrome is associated with erosive esophagitis

AIM： To clarify whether insulin resistance and metabolic syndrome are risk factors for erosive esophagitis.METHODS： A case-control study was performed using the database of the Kangbuk Samsung Hospital Medical Screening Center.RESULTS： A total of 1679 cases of erosive esophagitis and 3358 randomly selected controls were included. Metabolic syndrome was diagnosed in 21% of the cases and 12% of the controls （P 〈 0.001）. Multiple logistic regressions confirmed the association between erosive esophagitis and metabolic syndrome （Odds ratio, 1.25; 95% CI, 1.04-1.49）. Among the components of metabolic syndrome, increased waist circumference, elevated serum triglyceride levels and hypertension were significant risk factors for erosive esophagitis （all P 〈 0.01）. Furthermore, increased insulin resistance （Odds ratio, 0.91; 95% CI, 0.85-0.98） and fatty liver, as diagnosed by ultrasonography （odds ratio, 1.39; 95% CI, 1.20-1.60）, were also related to erosive esophagitis even afl：er adjustment for a series of confounding factors.CONCLUSION： Metabolic syndrome and increased insulin resistance are associated with an increased risk of developing erosive esophagitis.

Screening of stimulatory effects of dietary risk factors on mouse intestinal cell kinetics

AIM: Although epidemiological and experimental studies validate influence of genetic, environmental and dietary factors in the causation of various types of cancers including colon, results from all these sources are inconclusive. Hypothesizing that high fat diet and obesity are among the major predisposing factors in the incidence of colon cancer, we evaluated the role of diet constituted with food material derived from a tropical plant, Tamarindus indica Linn (TI). METHODS: A two part randomized double-blind study was conducted employing inbred Swiss albino mice from a single generation for the whole investigation. One day-old neonates (n=12) were subcutaneously administered with monosodium glutamate (MSG) to induce obesity (OB). At weaning these animals were maintained on modified AIN-76 diet supplemented with 10% TI and 10% fat bolus (w/w,TIFB) for 8 wk. Subsequently, in the second part of study, four groups of animals belonging to the same generation, age and gender (n=12 per group), were maintained on: AIN-76 control diet (CD); AIN-76 mixed with 10% TI extract (TI); and, mixed with 10% TI and 10% FB (TIFB) for 8 wk, to determine intestinal crypt cell proliferation, functionally-specific enzyme activities, fermentation profile, and energy preferences. RESULTS: We observed a significant increase in the crypt cell production rate in distal colonic segment of experimental animals when compared with the controls. This segment also contained significantly low butyrate levels compared to control and TIFB groups. All the experimental groups showed a gross decrease in the enzyme activities viz., succinate dehydrogenase, acid-galactosidase and dipeptidyl amino peptidase IV demonstrating pathological stress caused by the test regimens, and an altered metabolic flux in the cellular environment. CONCLUSION: We have demonstrated a cumulative response to the three dietary factors, one of which (TI) is reported, herein, for the first time to modulate kinetics of large intestinal mucosa, contributing to total risk posed by these test agents.

Role of bile acids, prostag landins and COX inhibitors in chronic esophagitis in a mouse model

AIM. To develop a new experimental model of esophagitis that serves a complementary tool to clinical investigation in an insight into the mechanism of the damage to the esophagus mucosa by aggressive factors, and role of COX inhibitors in this process. METHODS： The study was conducted in 56 male mice. Animals were divided into seven groups： （1） perfused with HCI, （2） perfused with HCI and physiologic concentration of pepsin （HCI/P）, （3） perfused with similar HCI/P solution enriched with conjugated bile acids （glycho- and tauro-sodium salts） designated esophageal infusion catheter under the general anesthesia, （4） perfused as in group 2 treated with indometacin, （5） perfused as in group 2 treated with NS-398, （6） perfused as in group 3 treated with indometacin, and （7） perfused as in group 3 treated with NS-398. The esophagus was divided into 3 parts： upper, middle and lower. The PGE2 concentration was measured in all parts of esophagus using RIA method. Esophagus of sacrificed animals was macroscopically evaluated using a low power dissecting microscope （20x）. Specimeris, representing the most frequently seen changes were fixed, stained with H＆E and assessed microscopically using the damage score, and inflammatory score. RESULTS： The macroscopic changes were significantly severer in HCI/P than those in HCI animals （77%） and in HCI/P/BA group （43%）. In HCI/P NS-398 group we noticed significantly less changes than those in not treated group （42%） and in analogical group treated with indometacine （45%）. In HCI/P/BA INDO group we observed significantly severer changes than that in not treated group （52%）. We noticed less changes in HCI/P NS-398 than that in group with indometacine （46%）. In HCI/P/BA NS-398 group we had less changes than that in indometacin group （34%）. The microscopic changes observed in HCI/P/BA INDO group were severer than that in not treated group （48%）. Esophagitis index in HCI group was significantly lower than in HCI/P and also HCI/P/BA group （32% and 33 %）. In HCI/P/BA/INDO group the esophagitis surface was larger than that in not treated group （33%）. In HCL/P group the surface of esophagus with ulceration was significantly larger （10-fold） than that in HCI/P/BA group. The PGE2 concentration was significantly higher in HCI/P group than in HCI/P/BA group. The PGE2 concentration in lower part of esophagus was also significantly higher in middle than those in HCI and HCI/P/BA groups. In upper part of esophagus the PGE2 concentration was significantly higher in HCI/P/BA group than that in group treated with indometacine （46%）. We also observed higher PGE2 concentration in middle part of esophagus in HCI/P/BA group than those in group treated with indometadne and in group treated with indometacin and NS-398 （by 52% and 43% respectively）. CONCLUSION： Pepsin is the pivotal factor in the development of chronic esophageal injury. Bile acids diminish chronic esophageal injury induced by HCI/P, indicating its potential negative impact on pepsin proteolytic potential, pivotal for mucosal injury in low pH. The role of selective COX inhibitors is still unclear, and needs more investigations. This novel chronic experimental esophagitis is an excellent model for further study on the role of cytokines in genetically modified animals.

Ontogenetic changes in isotopic signatures of an omnivorous fish Cultrichthys erythropterus in East Lake Taihu,China

The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter(C ultrichthys erythropterus),commonly found in East Lake Taihu,was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature(δ 13 C) in this study,in which δ 13 C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model,the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However,the stable nitrogen isotopic signature(δ 15N) exhibited an unusual pattern compared with previous studies. The δ 15 N of C. erythropterus showed no relationship with body size,even though dietary changes were observed. This indicated that δ 15 N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events,such as estimating the trophic positions of fish species.

Barrett's esophagus:Prevalence and risk factors in patients with chronic GERD in Upper Egypt

AIM： To determine the prevalence and possible risk factors of Barrett＇s esophagus （BE） in patients with chronic gastroesophageal reflux disease （GERD） in EI Minya and Assuit, Upper Egypt. METHODS： One thousand consecutive patients with chronic GERD symptoms were included in the study over 2 years. They were subjected to history taking including a questionnaire for GERD symptoms, clinical examination and upper digestive tract endoscopy. Endoscopic signs suggestive of columnar-lined esophagus （CLE） were defined as mucosal tongues or an upward shift of the squamocolumnar junction. BF was diagnosed by pathological examination when specialized intestinal metaplasia was detected histologically in suspected CLE. pH was monitored in 40 patients. RESULTS： BE was present in 7.3% of patients with chronic GERD symptoms, with a mean age of 48.3 ± 8.2 years, which was significantly higher than patients with GERD without BE （37.4 ± 13.6 years）. Adenocarcinoma was detected in eight cases （0.8%）, six of them in BE patients. There was no significant difference between patients with BE and GERD regarding sex, smoking, alcohol consumption or symptoms of GERD. Patients with BE had significantly longer esophageal acid exposure time in the supine position, measured by pH monitoring. CONCLUSION： The prevalence of BE in patients with GERD who were referred for endoscopy was 7.3%. BE seems to be associated with older age and more in patients with nocturnal gastroesophageal reflux.

Study Frequency of Antibiotic Resistance Enzymes in Bacillus Species in Some of Foods

The subject of this study was to survey prevalence Beta lactamase enzyme in Bacillus species isolated from foods in Isfahan city in Iran. This is a laboratory study performed during 2009-2010 years in Isfahan. In this study, 150 samples of food, including juice ketchup, mayonnaise,

Primary malignant melanoma of the esophagus:A case report

The authors present the clinical case of an 87-year-old Caucasian male admitted to the emergency room with hematemesis. He had a history of intermittent dys-phagia during the previous month. Endoscopic evaluation revealed an eccentric,soft esophageal lesionlocated 25-35 cm from the incisors,which appeared asa protrusion of the esophagus wall,with active bleeding. Biopsies were acquired. Tissue evaluation wascompatible with a melanoma. After excluding other sites of primary neoplasm,the definitive diagnosis of Primary Malignant Melanoma of the Esophagus(PMME) was made. The patient developed a hospital-acquired respiratory infection and died before tumor-directed treatment could begin. Primary malignant melanoma represents only 0.1% to 0.2% of all esophageal ma-lignant tumors. Risk factors for PMME are not defined.A higher incidence of PMME has been described in Japan. Dysphagia,predominantly for solids,is the most frequent symptom at presentation. Retrosternal orepigastric discom fort or pain,melena or hemate mesishave also been described. The characteristic endoscopic finding of PMME is as a polypoid lesion,with variablesize,usually pigmented. The neoplasm occurs in thelower two-thirds of the esophagus in 86% of cases.PMME metastasizes via hematogenic and lymphatic pathways. At diagnosis,50% of the patients present with distant metastases to the liver,the mediastinum,the lungs and the brain. When possible,surgery(curative or palliative) ,is the preferential method of treatment. There are some reports in the literature where chemotherapy,chemohormon otherapy,radiotherapy and immunotherapy,with or without surgery,wereused with variable efficacy. The prognosis is poor;themean survival after surgery is less than 15 mo.

Interleukin-10 -1082 promoter polymorphism is not associated with susceptibility to esophageal squamous cell carcinoma and gastric cardiac adenocarcinoma in a population of high-incidence region of north China

AIM: To investigate the possible association of G→A single nucleotide polymorphism (SNP) at the -1082 position of interleukin (IL)-10 promoter with susceptibility to esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA) in a population of a high incidence region of North China.METHODS: IL-10-G1082A promoter SNP was genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) in 355 cancer patients (203ESCC and 152 GCA) and 443 healthy controls.RESULTS: Smoking significantly increased the risk of ESCC and GCA development (the age and sex adjusted OR = 1.42and 2.64, 95%CI = 1.11-1.81 and 1.46-4.76, respectively).Similarly, family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing ESCC and GCA (the age and sex adjusted OR = 1.44 and 3.10,95%CI = 1.18-1.75 and 1.94-4.97, respectively). The A/A, A/G and G/G genotype frequencies of IL-10-G1082A were 60.3%, 37.0% and 2.7% in healthy controls, 57.6%,39.9% and 2.5% in ESCC and 61.2%, 36.8% and 2.0% in GCA patients, respectively. The frequencies of A and G alleles were 78.8% and 21.2% in healthy controls, 77.6%and 22.4% in ESCC patients and 79.6%, 20.4% in GCA patients. The distribution of genotype and allelotype in ESCC and GCA patients was not significantly different from that in healthy controls (P＞0.05). Compared to the A/A genotype, the combination of A/G and G/G genotypes did not show a significant effect on the risk of developing ESCC and GCA; the adjusted odds ratio was 0.92 (95%CI = 0.76-1.11) in ESCC and 0.95 (95% CI = 0.61-1.46)in GCA, respectively. When stratified for smoking status and family history of UGIC, the combination of A/G and G/G genotypes also did not show any significant influence on the risk of ESCC and GCA development compared to A/A genotypes.CONCLUSION: IL-10-G1082A polymorphism might not be used as a stratification marker to predicate the risk of ESCC and GCA development in North China.

Effect of dietary supplementation of vitamin C on growth, reactive oxygen species, and antioxidant enzyme activity of Apostichopus japonicus(Selenka) juveniles exposed to nitrite

Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels （0.5, 1.0, and 1.5 mg/L） of nitrite stress for 4, 8, and 12 h at four time intervals （0, 15, 30, and 45 d）. Growth of the animals was recorded during the experiment. Reactive oxygen species （ROS） （i.e. hydroxyl free radical （-OH）, malondialdehyde （MDA） and total antioxidant capacity （T-AOC）） and antioxidant enzyme activities （i.e., superoxide dismutase （SOD） and eatalase （CAT）） were measured. Response surface methodology （RSM） was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain （WG） and special growth rate （SGR） of vitamin C supplementation groups were significantly higher than those of control group （P〈0.05）. The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.

Effect of dietary genistein on growth performance,digestive enzyme activity,and body composition of Nile tilapia Oreochromis niloticus

An 8-week feeding experiment was performed to evaluate the effect of dietary genistein on growth performance,body composition,and digestive enzymes activity of juvenile Nile tilapia(Oreochromis niloticus).Four isonitrogenous and isoenergetic diets were formulated containing four graded supplements of genistein:0,30,300,and 3 000 μg/g.Each diet was randomly assigned in triplicate to tanks stocked with 15 juvenile tilapia(10.47±1.24 g).The results show that 30 and 300 μg/gdietary genistein had no significant effect on growth performance of Nile tilapia,but the higher level of genistein(3 000 μg/g)significantly depressed the final body weight and specific growth rate.There was no significant difference in survival rate,feed intake,feed efficiency ratio or whole body composition among all dietary treatments.An assay of digestive enzymes showed that the diet containing 3 000 μg/ggenistein decreased stomach and hepatopancreas protease activity,and amylase activity in the liver and intestine,while a dietary level of300 μg/g genistein depressed stomach protease and intestine amylase activities.However,no significant difference in stomach amylase activity was found among dietary treatments.Overall,the results of the present study indicate that a high level of dietary genistein(3 000 μg/g,or above) would significantly reduce the growth of Nile tilapia,partly because of its inhibitory effect on the activity of major digestive enzymes.Accordingly,the detrimental effects of genistein,as found in soybean products,should not be ignored when applied as an alternative ingredient source in aquaculture.

Feeding Enrichment and Leopard Pacing in Zoo Dvtur Kralove, a.s.

The aim of this study was find out how change the stereotypical behavior especially pacing of Persian leopards and if the leopards in zoo will be more active after addition of EE （environmental enrichment） element. There were 30 days observed 6 leopards： 2 females, 1 male and 3 cubs, with observation time per day about 300 min. 10 days were without enriched environment and 20 days with environment. The used elements were two big paper boxes with rabbit meat in each enclosure, laid out on the ground or hung on tree. All animals were in days with EE more active and the pacing was not observed or was reduced by females and cubs, male after giving the ＂toys＂ was active, but he was afraid of the big box first few days and the pacing was high. The EE had positive effect on animals. Some of the leopards spent more time with activity in succession--cubs with older female, young female and male.