教学课程资源库 更多>>

关键词： Antioxidant capacity   Carotenoids   Cyanobacteria   Fatty acids   Lipids   Photosynthetic activity   Phycobiliproteins  

摘要： Cyanobacteria are able to absorb light over a wide spectral range due to the presence of photoreceptors, making it possible to modulate the production of high-value compounds by inducing specific pathways. In order to evaluate the influence of light quality in cyanobacteria metabolism,Cyanobiumsp. was grown in five different light conditions, by using low-pressure sodium vapor lamp (SOX) supplemented with low irradiances of green, red, and blue light and UV radiation compared to a control with only SOX. The effects of light supplementation on biomass productivity, photosynthetic activity, biochemical composition, and total antioxidant capacity were evaluated. No changes in biomass productivity were induced by any light supplements. The supplementation of red light triggered the production of lipids, phycocyanin, carotenoids, and total antioxidant compounds, while supplementation of green light increased the content of carbohydrates and chlorophylla. Thus, supplementation of blue light and UV radiation showed little or no improvements to the culture, whereas under UV radiation the photosynthetic activity was reduced. Overall,Cyanobiumsp. is a promising strain, mainly due to its accessibility to metabolism photoregulation as to produce various bioactive compounds.

关键词： Prolactin   Prolactinoma   Cabergoline   Hypogonadism   Dopamine agonist withdrawal  

摘要： Purpose Treatment with dopamine agonists (DA) is highly effective in patients with prolactinomas. In selected patients, discontinuation of DA after several years of successful treatment is possible, however, hyperprolactinemia recurs in 60-80% of them. It is unclear what is the clinical significance of these recurrences and hence, whether or not reinitiation of therapy is necessary. Objectives To evaluate the recurrence rate in prolactinoma patients after DA withdrawal and the necessity to restart treatment. Methods Patients with >2 years of treatment with cabergoline (CBG) who achieved normoprolactinemia anda > 50% reduction in tumor size were included. DA dose was down titrated until withdrawal. Basal tumor size, as well as PRL and gonadal steroid levels were recorded at diagnosis, at withdrawal of DA and every 3-6 months for 1-3 years. Results Fifty patients were included (38 women, 34 macroprolactinomas). After withdrawal, 34 (68%) presented recurrence of hyperprolactinemia. PRL levels <5 ng/mL at the time of withdrawal predicted remission (sensitivity 76%, specificity of 63%). CBG was restarted in eight patients (23%) because of the presence of hypogonadism. CBG was withheld in the remaining 26, based on the following arguments: (1) premenopausal women without biochemical hypogonadism, (54%);(2) asymptomatic men under 65 without biochemical hypogonadism (19%);(3) asymptomatic postmenopausal women (19%);(4) asymptomatic men over 65 (8%). After a median follow-up of 30 months, no increase in PRL levels or tumor growth was documented. Conclusions Biochemical recurrence in prolactinomas is very frequent, however, in only a few of these patients reinitiation of DA is necessary.

关键词： APX activity   Chlorophyll contents   Flooding stress   Gene expression   Sweetpotato  

摘要： Sweetpotato [Ipomoea batatas (L.) Lam] serves as a sustainable food source and ensures nutrition security in the face of climate change. Recently, farmers have developed increased interest in replacing rice with sweetpotato in paddy fields for higher income. However, sweetpotato is more susceptible to flooding stress than other abiotic stresses including drought and salinity. Here, we selected flooding tolerant sweetpotato cultivars based on biochemical characterization. Young seedlings of 33 sweetpotato cultivars were subjected to flooding stress for 20 days, and Yeonjami (YJM) was identified as the most flooding tolerant sweetpotato cultivar. Plant growth and biochemical characteristics of YJM were compared with those of Jeonmi (JM), a flooding sensitive sweetpotato cultivar. Under flooding stress, YJM showed higher content of chlorophyll and lower inhibition of plant height and fibrous root length than JM. Biochemical characterization revealed that although malondialdehyde and hydrogen peroxide contents were increased in fibrous roots of both cultivars, the amount of increase was 4-fold lower in YJM than in JM. Additionally, leaves of YJM showed higher ascorbate pemxidase activity than those of JM under flooding stress. Our results suggest that high membrane stability and antioxidant capacity are important flooding tolerance factors in sweetpotato. Furthermore, several flooding tolerance-related genes involved in starch and sucrose metabolism, fermentation, and cell wall loosening showed earlier induction and higher transcript levels in YJM leaves and fibrous roots than in JM tissues under flooding stress. Thus, phenotypic and biochemical characterization suggests that YJM could be used as a flooding tolerant sweetpotato cultivar.

关键词： Ketone biosynthesis   Hypoglycemia   3-Hydroxy-3-methylglutaryl-CoA   4-Hydroxy-6-methyl-2pyrone   HMGCS2  

摘要： Thirty patients with mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS) deficiency, which is a rare autosomal recessive disorder caused by HMGCS2 gene mutation are known. Here, we present four new patients with this disease. The characteristics including several metabolites of patients were recorded. Next-generation targeted sequencing and multiple sequence alignment of PCR amplified products allowed for mutational analysis of HMGCS2. Minigene assay transcript analysis confirmed pathogenicity of a splice site mutation. All cases had recurrent episodes with infections while they had no symptoms during intermissions. Patient 1, a girl, showed recurrent severe metabolic acidosis after infections from 8 months old and presented with weakness, vomiting and lethargy but had normal blood glucose. After treatment, she revived completely. Patients 2, 3 and 4 were boys who showed episodes of hypoglycemia since 8, 27 and 10 months of age, respectively. Glucose infusion reversed the symptoms. All four patients had hepatomegaly and abdominal imaging showed fatty livers. Serum free fatty acid increased. Urinary dicarboxylic acids and urinary 4-hydroxy-6-methyl-2pyrone presented. Diagnosis was confirmed by HMGCS2 gene analysis and 7 mutations (p.R188H, p.F420S, p.R206C, IVS2 + 1G > T, p.E401*, p.A450Pfs*7 and p.Q427*) of this gene were found. Here we report on the characteristics and genetics of four new patients with HMGCS deficiency. This study will enrich our knowledge of this rare autosomal recessive disorder.

关键词： Sargassum horneri   Phaeophyceae   Antioxidant enzymes   Stress resistance   Gene expression   Acanthopagrus schlegelii  

摘要： Aquatic hypoxia is a frequent event and a complex set of physiological and biochemical alterations are employed to cope with this environmental stress in fish. This study aimed at evaluating the protective effects of Sargassum horneri on hypoxia stress in black sea bream Acanthopagrus schlegelii. Four hundred and eighty fingerlings with approximate mean body weight of 12.0 +/- 0.1 g were randomly distributed into four experimental groups in triplicate. Each group was stocked with 40 fish and fed with isonitrogenous (42% crude protein) and isolipidic (12% crude lipid) experimental diets containing either 0% (control), 3%, 6%, or 9% S. horneri in the feed. At the end of 8 weeks of experimental feeding, fish were exposed to hypoxia (dissolved oxygen 2.5 mg L-1) conditions for 12 h and subsequent recovery to normoxia (dissolved oxygen 7.2 mg L-1). Fish samples were collected after hypoxia stress at 0, 6, 12 h, and 12 h recovery to normoxia, respectively. Hypoxia stress caused a significant increase in the serum concentrations of cortisol, glucose, and lactate at 6 h after hypoxia, as well as the activities of hepatic superoxide dismutase (SOD) and MDA content at 12 h after hypoxia compared with 0 h after hypoxia. Moreover, the fish exhibited a significantly higher level in the mRNA expressions of hepatic Cu/Zn-SOD, HSP70, and HSP90 at 12 h after hypoxia. However, dietary S. horneri supplementation could significantly improve antioxidant capacity and resistance against hypoxia stress, particularly in the 6% S. horneri group. Therefore, the optimal dietary S. horneri level based on increasing the resistance of hypoxia for juvenile black sea bream in the present study was estimated to be approximately 6% dry diet.

关键词： Food oral processing   Dietary habits   Salivary alpha-amylase activity   Salivary lipolytic activity  

摘要： Saliva is an important component of food oral processing affecting the initial digestion and the formation of food bolus. It has been speculated that salivary biochemical properties could directly influence one's dietary habits, and vice versa. To date, there are few studies that investigate the possible relationships between dietary habits and salivary biochemical properties in Chinese participants from different dietary background. This study examined two Chinese ethnical groups of very different culture of food consumption, Han and Mongolian healthy young participants, as research participants to explore the differences in salivary biochemical properties and possible associations with dietary preferences. Chinese Mongolians tend to consume more red meat and dairy products, and Chinese Han tend to consume more carbohydrates as suggested by offlcial data;therefore, a total of 304 healthy participants (200 Han and 104 Mongolian) were recruited for salivary compositional analysis. Results showed that for Mongolian participants' unstimulated salivary lipolytic activity (0.10 U/mL) and stimulated salivary lipolytic activity (0.09 U/mL) are significantly higher than those of the Han (0.03 U/mL, 0.04 U/mL) (p < 0.01), but their stimulated salivary alpha-amylase activity (2733 U/mL) was significantly lower than that of Han (3596 U/mL) (p < 0.01). Unstimulated and stimulated salivary total protein content of Chinese Han participants were significantly higher than those of Mongolian participants (p < 0.0001, p = 0.043). These findings have showed our initial hypothesis of possible associations between dietary habits and salivary biochemical properties.

关键词： Brachypodium distachyon   Galactinol   Galactinol synthase   Raffinose   Thioredoxin   UDP-Sugar pyrophosphorylase  

摘要： Raffinose (Raf) protects plant cells during seed desiccation and under different abiotic stress conditions. The biosynthesis of Raf starts with the production of UDP-galactose by UDP-sugar pyrophosphorylase (USPPase) and continues with the synthesis of galactinol by galactinol synthase (GolSase). Galactinol is then used by Raf synthase to produce Raf. In this work, we report the biochemical characterization of USPPase (BdiUSPPase) and GolSase 1 (BdiGolSase1) from Brachypodium distachyon. The catalytic efficiency of BdiUSPPase was similar with galactose 1-phosphate and glucose 1-phosphate, but 5- to 17-fold lower with other sugar 1-phosphates. The catalytic efficiency of BdiGolSase1 with UDP-galactose was three orders of magnitude higher than with UDP-glucose. A structural model of BdiGolSase1 allowed us to determine the residues putatively involved in the binding of substrates. Among these, we found that Cys(261) lies within the putative catalytic pocket. BdiGolSase1 was inactivated by oxidation with diamide and H2O2. The activity of the diamide-oxidized enzyme was recovered by reduction with dithiothreitol or E. coli thioredoxin, suggesting that BdiGolSase1 is redox-regulated.

关键词： DNA methylation   Epigenetic   Selenium nanoparticle   Transcription factors   Toxicity  

摘要： This study aimed to explore whether supplementation of the culture medium with selenium nanoparticles (nSe) can influence growth, biochemistry, expression of transcription factors, and epigenetic DNA methylation in Capsicum annuum. The seeds were grown in hormone-free MS culture medium supplemented with nSe (0, 0.5,1, 10, and 30 mgL(-1)) or corresponding doses of bulk type selenate (BSe). Incorporation of nSe into the medium caused variations in morphology and growth in a manner dependent on the dose and Se type. The low doses of nSe displayed growth-promoting effects, whereas nSe at 10 and 30 mgL(-1) were associated with severe toxicity and abnormality in leaf and root development. MSAP analysis confirmed the substantial variation in cytosine DNA methylation in response to the toxic dose of nSe exhibiting epigenetic modification. The nSe toxicity was associated with DNA hypermethylations. The nSe treatments transcriptionally upregulated the bZIP1 transcription factor by an average of 3.5 folds. With a similar trend, the upregulation (mean = 9.8 folds) in the expression of the WRKY1 transcription factor resulted from the nSe application. The nSe0.5 or nSe1 treatments resulted in a significant induction (mean = 48%) in nitrate reductase activity. A high dose of nSe led to an increase in proline concentration. The nSe treatments were also associated with modifications in activities of peroxidase and catalase enzymes. Besides, the nSe utilization increased the activity of phenylalanine ammonia-lyase enzyme (mean = 76%) and concentrations of soluble phenols (mean = 51%). The toxic dose of nSe also caused abnormalities in the structure of the stem apical meristem. The nSe toxicity was also associated with inhibition in the differentiation of xylem tissues. These findings provide novel insights into the nSe-associated molecular variations in conferring the modified growth, anatomy, and metabolism. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Techno-economic analysis   IBE process   Cellulosic ethanol   Sugarcane bagasse  

摘要： This work presents a techno-economic analysis of the production of isopropanol, butanol, and ethanol (IBE) from sugarcane bagasse using clostridia and compares IBE with cellulosic ethanol for the minimum selling price (MSP) and sustainability aspects. The MSPs of the fuels are similar (15 USD/GJ) provided that glucose and xylose are effectively utilized in both processes, and the IBE process is equipped with a genetically-modified Clostridium species with enhanced IBE yield and a highly productive continuous bioreactor with integrated product recovery. Notably, these technologies can reduce the size (from 23 x 3785-m(3) to 3 x 3027-m(3) fermentation tanks) and the wastewater footprint (from 50 to 10 m(3)/m(3) IBE) of the IBE plant. Furthermore, given that the production of either fuel results in a similar increase in the value created by the sugarcane biorefinery and its energy efficiency, the alcohol mixture produced by clostridia is a promising alternative to the less energy-dense ethanol fuel.

摘要： Introduction. The number of pregnant kidney graft recipients receiving immunosuppressive drugs is increasing yearly. All potentially nephrotoxic and hepatotoxic immunosuppressive drugs penetrate through the placenta, which raises questions about their long-term effects on offspring. Objectives. The study aimed to evaluate the influence of immunosuppressive drugs used by pregnant women after kidney transplantation on the biochemical parameters of their children. Materials and methods. Forty children born to mothers after kidney transplantation (KTx) and 40 children of healthy mothers from the control group were included in the study. All graft-recipient mothers received immunosuppressive treatment during pregnancy. The study compared biochemical parameters, including urea, creatinine, potassium, and sodium, in both groups. Results. Elevated creatinine level was observed in 1 newborn in the KTx group and none of the children from the control group (P = .500). All KTx children had normal urea levels, while in the control group, 2 newborns had an increased level of urea (P = .247). Elevated potassium levels were observed in 10% of children in the KTx group and 20% of children in the control group (chi(2) = 0.881;P = .348). Elevated sodium levels were observed in 22.5% of children in the KTx group and 32.5% of children in the control group (chi(2) = 1.001;P = .317). No child in the KTx group had hyponatremia;mild hyponatremia was observed in 5% of children in the control group (P = .247). Conclusion. There was no increased risk of an abnormal concentration of urea, creatinine, sodium, and potassium in the offspring of mothers after kidney transplantation using immunosuppressive drugs during pregnancy.