This article has comprehensively summarized the photosynthesis system in plant, illustrated by representative case studies. The improvement in both study theory and research method of physiological responses to various environmental stress have been substantially discussed in each part.
论道教三魂七魄学说与生命起源哲学 Author:Liu Huan (1983-), Master of Science (First Class Honours), The University of Auckland.
Article 14. Original review of specificity in the interaction between pathogen invasion and host organism Author: Liu Huan (1983- ), Master of Science (First Class Honours), The University of Auckland.
The cros¬s-sectional study was conducted at four peasants’ associations (PAs) in Arero district of Borana zone, namely Halona, Fuldowa, Silala and Renji. The seroprevallence and potential risk factors of Brucellosis in sheep and goats in study area were determined using serological tests. Serum samples were collected from 238 unvaccinated and apparently healthy sheep and goats. The samples were serologically examined by Rose Bengal Plate Test (RBPT) for first screening test and confirmed by Indirect-ELISA. Almost half of samples that screened positive with RBPT became negative after confirmation by an indirect ELISA test. Out of 238 sera extracted from sheep and goat in the study area, 18(7.56%) animals were found to be positive by RBPT screening. Of all serum samples tested positive by indirect ELISA and confirmed by retest, 8(3.7%) animals were found to be positive. By direct ELISA, of 183 sera from caprine, 6(2.5%) animals were positive, 177(74%) animals were negative; 2 (0.84%) of 55 sera from ovine brucellosis were positive. The seroprevalence of sheep and goats in the Arero district did not show significance among peasant associations (χ2 = 2.070, P value=0.558), age groups (χ2 = 0.531), P value=0.392) and between species (χ2 = 0.017, P value=0.897). The disease was prevalent in both female (4, 1.68%) and male (4, 1.7%), but was more prevalent in male (11% within male population) than female (2% within female population), showing a very high significance with p-value at 0.005 and Chi-Square at 7.842. These positive animals may pose a potential risk to both animals and humans in the area. Therefore, attention should be paid to the certification of breeding bucks or rams to reduce the spread of disease in animals and humans.
The search for natural plant extract as an alternative therapy to diabetes management has received enormous recognition globally. In this study, the effects of the methanol extracts of Gongronema latifolium leaves (GLE) on glycaemic responses to carbohydrate diets [obtained from cassava (Manihot esculenta), yam (Dioscorea rotundata) and plantain (Musa paradisiaca)] in streptozotocin-induced diabetic rats was investigated. Forty five adult male Wistar albino rats were induced diabetes by intraperitoneal (i.p.) injection of streptozotocin (STZ) (65 mg/kg b.w.) dissolved in citrate buffer, pH 4.5. The diabetic rats were divided into nine groups of 5 animals each. Group 1: the Positive control (diabetic, untreated) was fed with water only, group 2: the standard control (diabetic, treated) received 2.50mg/kg b.w of glibenclamide, a standard drug for diabetes, group 3, 4 ad 5 (carbohydrate diets treated only) were orally fed with 200 mg/kg b.w. of cassava diet, 200 mg/kg b.w. of yam diet and 200 mg/kg b.w. of plantain diet respectively, group 6, 7 ad 8 (GLE mixed with carbohydrate diets treated) were orally fed with 200 mg/kg b.w. of cassava mixed with 100 mg/kg b.w. of GLE, 200 mg/kg b.w. of yam mixed with 100 mg/kg b.w. of GLE and 200 mg/kg b.w. of plantain mixed with 100 mg/kg b.w. of GLE respectively, while group 9 (GLE treated only) was fed with 100 mg/kg b.w. of GLE only. The experiment lasted for 21 days with free access to feed and water. Animals’ weights were measured on weekly basis as well as estimation of fasting blood sugar (FBG) and postprandial blood glucose (PBG). Results revealed that, administration of carbohydrate diets led to a significant (p < 0.05) decrease in body weights of the diabetic rats fed with carbohydrate diets. Conversely, administration of the GLE mixed with the diets caused a significant (p > 0.05) increase in body weights of the diabetic rats compared to the positive control. However, treatment with GLE alone showed a more effectuality which is comparable to that of the standard drug in restoring weight loss. In addition, the results of blood glucose estimation revealed a significant (p < 0.05) elevation in both fasting blood glucose (FBG) and Postprandial blood glucose (PBG) in animals fed with carbohydrate diets when compared to the positive control, but a significant (p < 0.05) decrease was observed in both parameters upon the admiistration of GLE mixed with carbohydrate diets. Similarly, administration of GLE alone caused an increase in both FBG and PBG which was significant (p < 0.05) compared to group fed with GLE mixed with carbohydrate diets. Howbeit, GLE elicited more potent and efficacious response when compared to the standard drug. Herein, we therefore deduce that methanolic extracts of G. latifolium leaves exhibited hypoglycaemic responses in the diabetic rats and the plant could be a worthwhile candidate in the design of a potent antidiabetic drug.
Background and Objective: Stem-bark of Albizia chevalieri has been used to kill fish by local fishermen over the years in some parts of Nigeria.This study investigated the effect of aqueous stem-bark extract of Albizia chevalieri on the liver and kidney of juvenile African catfish, Clarias gariepinus.Materials and Methods: Clarias gariepinus was purchased and acclimatized for 2 weeks in laboratory aquaria.An acute toxicity test was conducted with eighty fish divided into eight groups in aquaria containing ten fish each.The groups were respectively exposed to 800, 400, 200, 120, 80, 60, 40 and 0 mg LG 1 of the aqueous extract of A. chevalieri to obtain the 96 hrs LC 50 of 77.915 mg LG 1 .In the sub-acute studies, a total of 48 acclimatized fish were divided into four groups containing 12 fish in each aquarium.Group 1 served as the normal control, while groups 2-4 were respectively exposed to three sub-lethal concentrations of 19.48, 9.74 and 7.79 mg LG 1 of the extract, corresponding to the 1/4th, 1/8th and 1/10th of the 96 h LC 50, for 16 days.Results: The result from the serum collected every 4 days showed significant (p<0.05)increases in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), with significant (p<0.05)increases in the concentrations of direct bilirubin, total protein, creatinine, urea, sodium and potassium.From the acute toxicity test result, there was no survival in aquaria containing 200-800 mg LG 1 of aqueous extract of A. chevalieri.Conclusion: The results showed that the death of fish on exposure to aqueous stem-bark extract of A. chevalieri could be a result of liver and kidney damages.
Article 1-2. Classification of Bacteria by DNA Genetic Marker and Its Theory/DNA遗传标记与细菌分类以及相关理论 Author: Liu Huan(1983 - ), Master of Science (First Class Honours), The University of Auckland.
Background and Objective: Stress has been observed to alter male reproductive function through the effect of HPA on the adult male Wistar rat.Humans are consistently being exposed to stressful conditions on daily basis.The objective of this study was to determine the role of rotatory cage induced stress on the alteration of liver function in male Wistar rats.Materials and Methods: The effect of exposure to a stressor on liver function test of male Wistar rats was carried out in this study using 72 adult male Wistar rats.The rats used were weighed between 180 and 240 g.The rats were obtained from the Animal House of Delta State University, Abraka.The animals were allowed to acclimatize to the laboratory condition for 2 weeks.They were divided into group 1 (1 week exposure) group 2 (2 weeks exposure) and group 3 (3 weeks exposure) to the stressor.Each of the groups was further divided into control, with stress duration of 1, 3 and 5 hrs containing six (6) rats each.Data generated were expressed as Mean±SEM.Data generated were statistically analyzed using One-way Analysis of Variance (ANOVA) and a student t-test to compare the means, p<0.05 was considered significant.Results: The results showed a significant (p<0.05)stepwise decrease in cholestasis markers as evidenced by the decrease in Alanine Phosphatase (ALP) due to exposure of the rats to stressors for 1, 3 and 5 hrs relative to control rats.The results for ALT showed upon exposure to stressors for 1, 3 and 5 hrs, there was a significant (p<0.05)stepwise decrease in ALT when compared to the control irrespective of the duration of treatment with the 5 hrs exposure group showing a greater decrease in liver ALT relative to the rat's control group.The result for liver Aspartate Transaminase (AST) showed a significant (p<0.05)decrease in serum AST relative to 1 hr and control treatment group.Conclusion: However, the result of the rats following exposure to stressors for 5 hrs shows a greater significant (p<0.05)decrease relative to 1, 3 hrs and the control exposure group irrespective of the duration of exposure.
Article 4. Metabolomics and Application on The Specificity of Host-Invasion Interaction/新陈代谢组学在宿主细胞与生物入侵关系的专一性机制中的应用研究 Author: Liu Huan (1983-), Master of Science (First Class Honours), The University of Auckland
Background and Objective: Cajanus cajan is traditionally used for the treatment of various ailments due to its antioxidant properties.The present study investigated the effect C. cajan crude aqueous leaf extract (CCLE ) in rats with acetaminophen (APAP)-induced acute renal injury.Materials and Methods: Preliminary acute toxicity testing of the extract was conducted to determine the oral median lethal dose (LD 50 ).Twenty rats were divided into five experimental groups labelled (A-E) of 4 rats per cage.Group A served as the normal control group and was given only water and feed.Rats in groups C, D and E received 100 mg kgG 1 b.wt., of ascorbic acid, 200 and 500 mg kgG 1 of CCLE, respectively once daily for 7 days via oral route using an oral cannula.Thirty min after the daily treatments, 600 mg kgG 1 b.wt., of acetaminophen (APAP) was administered orally to rats in groups B-E.At the end of the treatments, blood samples were collected from the animals via retro-orbital puncture for the estimation of serum urea, creatinine and uric acid levels.The rats were sacrificed under anaesthesia and the kidneys were excised for histopathological analysis.Results: Acute toxicity testing showed that CCLE has an oral LD 50 of 8000 mg kgG 1 b.wt.Serum biochemistry showed a statistically significant increase (p>0.05) in creatinine and uric acid levels in all treatment groups when compared to normal control.Histopathological findings revealed the observable renal injury, with CCLE-treated groups showing more severe histomorphological alterations when compared to the APAP (negative) control.Conclusion: Data obtained suggest that acute toxicity was not observed with C. cajan administration up to 8 g kgG 1 , however, its co-administration with a high dose of acetaminophen does not protect the kidneys but rather aggravates the acute renal injury.
Article 11. Discussion on Gene Sequencing and Classification of DNA Genetic Markers Author: Liu Huan (1983-), Master of Science (First Class Honours), The University of Auckland
Background and Objective: Traditional and alternative medicine has been of immense help to developing countries as the source of therapy for many diseases.Recently many drugs are sourced from natural sources because of afford ability and ease of accessibility.This study was carried out to evaluate the in vitro ACE inhibitory activity and antioxidant potentials of aqueous extract of Combretum micranthum leaves and its fractions.Materials and Methods: Aqueous extract of Combretum micranthum leaves was subjected to chromatographic fractionation and the fractions obtained were assayed for in vitro inhibitory activity against rabbit ACE followed by their possible antioxidant potentials.Results: Aqueous extract of Combretum micranthum leaves produced 59.43±4% inhibitory activity comparable to captopril which produced 83.02±2.67%activity.The fractions A, B, C and D were able to inhibit the in vitro activity of rabbit ACE with the inhibitory percentages of 8.21±1.19,97.69±8.57,78.32±7.14 and 98.32±2.66%,respectively.The antioxidant potency of these fractions was evident in their free radical scavenging IC 50 , reducing power ability and total antioxidant capacity which all showed that fraction B may exhibit the highest antioxidant potency as compared to fractions C and D. The bioactive phytochemical constituents from the GC-MS analysis of fraction B of the aqueous extract of Combretum micranthum was found to be Megastigmatrienone, 3,5-Dimethoxy-4-hydroxyphenyl acetic acid and Estra-1,3,5(0)-trien-17$-ol.Conclusion: It was obvious from the findings that aqueous extract of Combretum micranthum has showed the tendency to inhibit the in vitro activity of ACE which could be attributed to its antioxidant activity demonstrated by the reduction power and the total antioxidant capacity of the various fractions.
Background and Objective: E-cigarettes (e-cig) produce smoke with high levels of free oxidants, which can be eliminated by endogenous antioxidants such as glutathione peroxidase (GPx) and catalase (CAT) in the human body.The GPx catabolizes hydrogen peroxide (H 2 O 2 ), while catalase counteracts free radicals by catalyzing H 2 O 2 into H 2 O and O 2 .However, oxidative stress is shown in the imbalance condition between free oxidants and endogenous antioxidants.The effect of e-cigarette smoking on the human body has not been discovered.Therefore, this research aimed to analyze the levels of GPx and CAT in the rat blood exposed to e-cig.Materials and Methods: The exposure to smoke with nicotine 3, 6 and 9 mg was applied to 30 rats divided into five groups for 30 days.The analysis results by one-way ANOVA showed significant differences in the GPx and CAT levels between the control and treatment groups.Nicotine at 9 mg gave the GPx level at 40.25±2.03U mgG 1 and CAT at 2.46±0.50nmol mLG 1 .Results: The results indicated that e-cigarette smoke reduced the levels of endogenous antioxidants in rat blood.Moreover, the body weight of rats increased and decreased due to the unstable metabolic rate.Conclusion: Exposure to e-cigarette smoke has an effect on reducing glutathione peroxidase (GPx) and catalase (CAT) levels in rat blood.
Article 8: Gene Therapy and Gene Modification in Nature /基因治疗与自然界基因修改 Author: Liu Huan (1983-), Master of Science (First Class Honours), The University of Auckland.
