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1.
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2.
Toxic dinoflagellate Alexandrium spp. produce saxitoxins (STXs), whose biosynthesis pathway is affected by temperature. However, the link between the regulation of the relevant genes and STXs’ accumulation and temperature is insufficiently understood. In the present study, we evaluated the effects of temperature on cellular STXs and the expression of two core STX biosynthesis genes (sxtA4 and sxtG) in the toxic dinoflagellate Alexandrium catenella Alex03 isolated from Korean waters. We analyzed the growth rate, toxin profiles, and gene responses in cells exposed to different temperatures, including long-term adaptation (12, 16, and 20 °C) and cold and heat stresses. Temperature significantly affected the growth of A. catenella, with optimal growth (0.49 division/day) at 16 °C and the largest cell size (30.5 µm) at 12 °C. High concentration of STXs eq were detected in cells cultured at 16 °C (86.3 fmol/cell) and exposed to cold stress at 20→12 °C (96.6 fmol/cell) compared to those at 20 °C and exposed to heat stress. Quantitative real-time PCR (qRT-PCR) revealed significant gene expression changes of sxtA4 in cells cultured at 16 °C (1.8-fold) and cold shock at 20→16 °C (9.9-fold). In addition, sxtG was significantly induced in cells exposed to cold shocks (20→16 °C; 19.5-fold) and heat stress (12→20 °C; 25.6-fold). Principal component analysis (PCA) revealed that low temperature (12 and 16 °C) and cold stress were positively related with STXs’ production and gene expression levels. These results suggest that temperature may affect the toxicity and regulation of STX biosynthesis genes in dinoflagellates.  相似文献   

3.
Background: Interferon α-2b is a vital biotherapeutic produced through the recombinant DNA technology in E. coli. The recombinant IFN-α2b normally appears as intercellular IBs, which requires intensive refolding and purification steps. Method:Purification of IFN-α2b from solubilized IB was performed using two-phase extraction. To optimize refolding conditions, the effects of pH and different additives, including cysteine, cystine, urea, glycerol, Triton X-100, NaCl, and arginine, were investigated. Optimal refolding buffer (0.64 mM of urea, 5.57 mM of cysteine ​​, and 1.8 mM of cystine) was obtained using RSM. The refolding process was performed by an optimized refolding buffer in the dilution and fed-batch refolding method at different protein concentrations (25-1000 µg/mL). Result: At a final protein concentration of 500 µg/mL, the fed-batch refolding method yielded in a biological activity of 2.24 × 108 IU/mg, which was nearly twice that of dilution method. Conclusion:Fed-batch refolding method resulted in the biologically active IFN-α2b with high purity, which can be used for research and industrial purposes. Key Words: Interferon alpha-2b, Inclusion bodies, Protein refolding  相似文献   

4.
The aim of the present work was to evaluate the effects of Thalassia testudinum hydroethanolic extract, its polyphenolic fraction and thalassiolin B on the activity of phase I metabolizing enzymes as well as their antimutagenic effects. Spectrofluorometric techniques were used to evaluate the effect of tested products on rat and human CYP1A and CYP2B activity. The antimutagenic effect of tested products was evaluated in benzo[a]pyrene (BP)-induced mutagenicity assay by an Ames test. Finally, the antimutagenic effect of Thalassia testudinum (100 mg/kg) was assessed in BP-induced mutagenesis in mice. The tested products significantly (p < 0.05) inhibit rat CYP1A1 activity, acting as mixed-type inhibitors of rat CYP1A1 (Ki = 54.16 ± 9.09 μg/mL, 5.96 ± 1.55 μg/mL and 3.05 ± 0.89 μg/mL, respectively). Inhibition of human CYP1A1 was also observed (Ki = 197.1 ± 63.40 μg/mL and 203.10 ± 17.29 μg/mL for the polyphenolic fraction and for thalassiolin B, respectively). In addition, the evaluated products significantly inhibit (p < 0.05) BP-induced mutagenicity in vitro. Furthermore, oral doses of Thalassia testudinum (100 mg/kg) significantly reduced (p < 0.05) the BP-induced micronuclei and oxidative damage, together with an increase of reduced glutathione, in mice. In summary, Thalassia testudinum metabolites exhibit antigenotoxic activity mediated, at least, by the inhibition of CYP1A1-mediated BP biotransformation, arresting the oxidative and mutagenic damage. Thus, the metabolites of T. testudinum may represent a potential source of chemopreventive compounds for the adjuvant therapy of cancer.  相似文献   

5.
Background: Pseudomonas aeruginosa is one of the opportunistic pathogens causing frequent hospital-acquired life-threatening infections in mechanically ventilated patients. The most significant virulence factor of P. aeruginosa is T3SS. PcrV is an important structural protein of the T3SS. Methods:In the current investigation, a recombinant scFv mAb against the PcrV protein was expressed in EnBase® (fed-batch) cultivation mode. The pETiteTM N-His SUMO Kan vector, including anti-PcrV scFv gene, was transformed into Escherichia coli (BL21) cells. The expression and solubility of anti-PcrV scFv protein were investigated at two different temperatures (25 °C and 30 °C) and at different induction times (4, 6, 8, 12, and 24 hours). Results:Increased efficiency was achieved by EnBase® compared to LB broth; owing to the slow release of glucose, the maximum level of solubility and total protein expression was observed in EnBase® cultivation system at 30 °C and 24 h post induction. Furthermore, IC50 for anti-PcrV scFv protein was determined to be approximately 7 μg/mL. Conclusion:Anti-PcrV scFv produced in this study showed promising in vitro results, protecting RBC from lysis by P. aeruginosa (exoU+). Key Words: Fed Batch, recombinant protein, Pseudomonas aeruginosa, scFv  相似文献   

6.
Intermittent hypobaric hypoxia (IH) is linked with oxidative stress, impairing cardiac function. However, early IH also activate cardio-protective mechanisms. Omega 3 fatty acids (Ω3) induce cardioprotection by reducing infarct size and reinforcing antioxidant defenses. The aim of this work was to determine the combined effects of IH and Ω3 on cardiac function; oxidative balance and inflammatory state. Twenty-eight rats were randomly divided into four groups: normobaric normoxia (N); N + Ω3 (0.3 g·kg−1·day−1); IH; and IH + Ω3. IH was induced by 4 intercalate periods of hypoxia (4 days)—normoxia (4 days) in a hypobaric chamber during 32 days. At the end of the exposure, hearts were mounted in a Langendorff system and subjected to 30 min of ischemia followed by 120 min of reperfusion. In addition, we determined HIF-1α and ATP levels, as well as oxidative stress by malondialdehyde and nitrotyrosine quantification. Further, the expression of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase was determined. NF-kappaB and myeloperoxidase levels were assessed in the hearts. Relative to N hearts, IH improved left ventricular function (Left ventricular developed pressure: N; 21.8 ± 3.4 vs. IH; 42.8 ± 7.1 mmHg; p < 0.05); reduced oxidative stress (Malondialdehyde: N; 14.4 ± 1.8 vs. IH; 7.3 ± 2.1 μmol/mg prot.; p < 0.05); and increased antioxidant enzymes expression. Supplementation with Ω3 induces similar responses as IH group. Our findings suggest that both, IH and Ω3 in an independent manner, induce functional improvement by antioxidant and anti-inflammatory mechanisms, establishing cardio-protection.  相似文献   

7.
Reactive oxygen species (ROS) are the key factors that cause many diseases in the human body. Polysaccharides from seaweed have been shown to have significant antioxidant activity both in vivo and in vitro. The ameliorative effect of Ulva lactuca polysaccharide extract (UPE) on renal injury induced by oxidative stress was analyzed. As shown by hematoxylin–eosin staining results, UPE can significantly improve the kidney injury induced by D-galactose (D-gal). Additionally, the protective mechanism of UPE on the kidney was explored. The results showed that UPE could decrease the levels of serum creatinine (Scr), blood urea nitrogen (BUN), serum cystatin C (Cys-C), lipid peroxidation, protein carbonylation, and DNA oxidative damage (8-OHdG) and improve kidney glutathione content. Moreover, UPE significantly increased the activities of superoxide dismutase and glutathione peroxidase and total antioxidant activity in mice. UPE also decreased the levels of inflammatory cytokines TNF-α and IL-6. Further investigation into the expression of apoptotic protein caspase-3 showed that UPE decreased the expression of apoptotic protein caspase-3. These results indicate that UPE has a potential therapeutic effect on renal injury caused by oxidative stress, providing a new theoretical basis for the treatment of oxidative damage diseases in the future.  相似文献   

8.
In this study, Spirulina maxima derived pectin nanoparticles (SmPNPs) were synthesized and multiple biological effects were investigated using in vitro and in vivo models. SmPNPs were not toxic to Raw 264.7 cells and zebrafish embryos up to 1 mg/mL and 200 µg/mL, respectively. SmPNPs upregulated Il 10, Cat, Sod 2, Def 1, Def 2, and Muc 1 in Raw 264.7 cells and tlr2, tlr4b, tlr5b, il1β, tnfα, cxcl8a, cxcl18b, ccl34a.4, ccl34b.4, muc5.1, muc5.2, muc5.3, hamp, cstd, hsp70, cat, and sod1 in the larvae and adult zebrafish, suggesting immunomodulatory activity. Exposure of larvae to SmPNPs followed by challenge with pathogenic bacterium Aeromonas hydrophila resulted a two-fold reduction of reactive oxygen species, indicating reduced oxidative stress compared to that in the control group. The cumulative percent survival of larvae exposed to SmPNPs (50 µg/mL) and adults fed diet supplemented with SmPNPs (4%) was 53.3% and 76.7%, respectively. Topical application of SmPNPs on adult zebrafish showed a higher wound healing percentage (48.9%) compared to that in the vehicle treated group (38.8%). Upregulated wound healing markers (tgfβ1, timp2b, mmp9, tnfα, il1β, ccl34a.4, and ccl34b.4), enhanced wound closure, and restored pigmentation indicated wound healing properties of SmPNPs. Overall, results uncover the multiple bioactivities of SmPNPs, which could be a promising biocompatible candidate for broad range of aquatic and human therapies.  相似文献   

9.
Background:One of the main challenges with conventional scaffold fabrication methods is the inability to control scaffold architecture. Recently, scaffolds with controlled shape and architecture have been fabricated using 3D-printing. Herein, we aimed to determine whether the much tighter control of microstructure of 3DP PLGA/β-TCP scaffolds is more effective in promoting osteogenesis than porous scaffolds produced by solvent casting/porogen leaching. Methods:Physical and mechanical properties of porous and 3DP scaffolds were studied. The response of pre-osteoblasts to the scaffolds was analyzed after 14 days. Results:The 3DP scaffolds had a smoother surface (Ra: 22 ± 3 µm) relative to the highly rough surface of porous scaffolds (Ra: 110 ± 15 µm). Water contact angle was 112 ± 4° on porous and 76 ± 6° on 3DP scaffolds. Porous and 3DP scaffolds had the pore size of 408 ± 90 and 315 ± 17 µm and porosity of 85 ± 5% and 39 ± 7%, respectively. Compressive strength of 3DP scaffolds (4.0 ± 0.3 MPa) was higher than porous scaffolds (1.7 ± 0.2 MPa). Collagenous matrix deposition was similar on both scaffolds. Cells proliferated from day 1 to day 14 by fourfold in porous and by 3.8-fold in 3DP scaffolds. ALP activity was 21-fold higher in 3DP scaffolds than porous scaffolds. Conclusion:The 3DP scaffolds show enhanced mechanical properties and ALP activity compared to porous scaffolds in vitro, suggesting that 3DP PLGA/β-TCP scaffolds are possibly more favorable for bone formation. Key Words: Alkaline phosphatase, β-tricalcium phosphate, Poly(lactic-co-glycolic) acid copolymer  相似文献   

10.
Background:This study was devoted to assessing the inhibitory potential of acetone, methanol, and ethanol extracts of Acroptilon repens against disease-associated enzymes, as well as their antioxidant/antibacterial activity and phytochemical composition. Methods:Comparative assessment using various antioxidant evaluation methods, including FRAP, scavenging ability on DPPH radical and hydrogen peroxide, and RP, indicated that the acetone extract presented the highest antioxidant activity, due to its highest total antioxidant content. Results:The TPC and TFC of these extracts were 3.44 ± 0.32 mg GAE/g DW and 2.09 ± 0.2 mg QE/g DW, respectively. The hydrodistillation essential oil from A. repens was analyzed by GC/MS, and 17 compounds were identified. All extracts showed good inhibitory activities against disease-related enzyme acetylcholinesterase and α-amylase, with the lowest IC50 for acetonic extract. Extracts of A. repens exhibited inhibiting activities against the Gram-positive bacteria, with the most effect of acetone extract. Conclusion:Our findings suggest A. repens as a promising source of natural antioxidant, antimicrobial, anti-cholinesterase and anti-amylase agents for the management of oxidative damage, and pharmaceutical, food, and cosmeceutical purposes. Key Words: Acroptilon repens, Antioxidants, Phytochemicals  相似文献   

11.
The objective of the present study was to test whether a brown seaweed extract rich in polyphenols combined with a low-calorie diet would induce additional weight loss and improve blood glucose homeostasis in association with a metabolic and inflammatory response in overweight/obese prediabetic subjects. Fifty-six overweight/obese, dysglycemic, and insulin-resistant men and women completed a randomized, placebo-controlled, double-blind, and parallel clinical trial. Subjects were administrated 500 mg/d of either brown seaweed extract or placebo combined with individualized nutritional advice for moderate weight loss over a period of 12 weeks. Glycemic, anthropometric, blood pressure, heart rate, body composition, lipid profile, gut integrity, and oxidative and inflammatory markers were measured before and at the end of the trial. No effect was observed on blood glucose. We observed significant but small decreases in plasma C-peptide at 120 min during 2 h-OGTT (3218 ± 181 at pre-intervention vs. 2865 ± 186 pmol/L at post-intervention in the brown seaweed group; 3004 ± 199 at pre-intervention vs. 2954 ± 179 pmol/L at post-intervention in the placebo group; changes between the two groups, p = 0.002), heart rate (72 ± 10 at pre-intervention vs. 69 ± 9 (n/min) at post-intervention in the brown seaweed group; 68 ± 9 at pre-intervention vs. 68 ± 8 (n/min) at post-intervention in the placebo group; changes between the two groups, p = 0.01), and an inhibition in the increase of pro-inflammatory interleukin-6 (IL-6) (1.3 ± 0.7 at pre-intervention vs. 1.5 ± 0.7 pg/L at post-intervention in the brown seaweed group; 1.4 ± 1.1 at pre-intervention vs. 2.2 ± 1.6 pg/L at post-intervention in the placebo group; changes between the two groups, p = 0.02) following brown seaweed consumption compared with placebo in the context of moderate weight loss. Although consumption of brown seaweed extract had no effect on body weight or blood glucose, an early attenuation of the inflammatory response was observed in association with marginal changes in metabolic parameters related to the prevention of diabetes type 2.  相似文献   

12.
This work aimed to evaluate the effects of dietary supplementation with β-glucans extracted from yeast (Saccharomyces cerevisiae) and microalga (Phaeodactylum tricornutum) on gene expression, oxidative stress biomarkers and plasma immune parameters in gilthead seabream (Sparus aurata) juveniles. A practical commercial diet was used as the control (CTRL), and three others based on CTRL were further supplemented with different β-glucan extracts. One was derived from S. cerevisiae (diet MG) and two different extracts of 21% and 37% P. tricornutum-derived β-glucans (defined as Phaeo21 and Phaeo37), to give a final 0.06% β-glucan dietary concentration. Quadruplicate groups of 95 gilthead seabream (initial body weight: 4.1 ± 0.1 g) were fed to satiation three times a day for 8 weeks in a pulse-feeding regimen, with experimental diets intercalated with the CTRL dietary treatment every 2 weeks. After 8 weeks of feeding, all groups showed equal growth performance and no changes were found in plasma innate immune status. Nonetheless, fish groups fed β-glucans supplemented diets showed an improved anti-oxidant status compared to those fed CTRL at both sampling points (i.e., 2 and 8 weeks). The intestinal gene expression analysis highlighted the immunomodulatory role of Phaeo37 diet after 8 weeks, inducing an immune tolerance effect in gilthead seabream intestine, and a general down-regulation of immune-related gene expression. In conclusion, the results suggest that the dietary pulse administration of a P. tricornutum 37% enriched-β-glucans extract might be used as a counter-measure in a context of gut inflammation, due to its immune-tolerant and anti-oxidative effects.  相似文献   

13.
Bioassay-guided fractionation using different chromatographic and spectroscopic techniques in the analysis of the Red Sea soft coral Litophyton arboreum led to the isolation of nine compounds; sarcophytol M (1), alismol (2), 24-methylcholesta-5,24(28)-diene-3β-ol (3), 10-O-methyl alismoxide (4), alismoxide (5), (S)-chimyl alcohol (6), 7β-acetoxy-24-methylcholesta-5-24(28)-diene-3,19-diol (7), erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8), and 24-methylcholesta-5,24(28)-diene-3β,7β,19-triol (9). Some of the isolated compounds demonstrated potent cytotoxic- and/or cytostatic activity against HeLa and U937 cancer cell lines and inhibitory activity against HIV-1 protease (PR). Compound 7 was strongly cytotoxic against HeLa cells (CC50 4.3 ± 0.75 µM), with selectivity index of SI 8.1, which was confirmed by real time cell electronic sensing (RT-CES). Compounds 2, 7, and 8 showed strong inhibitory activity against HIV-1 PR at IC50s of 7.20 ± 0.7, 4.85 ± 0.18, and 4.80 ± 0.92 µM respectively. In silico docking of most compounds presented comparable scores to that of acetyl pepstatin, a known HIV-1 PR inhibitor. Interestingly, compound 8 showed potent HIV-1 PR inhibitory activity in the absence of cytotoxicity against the cell lines used. In addition, compounds 2 and 5 demonstrated cytostatic action in HeLa cells, revealing potential use in virostatic cocktails. Taken together, data presented here suggest Litophyton arboreum to contain promising compounds for further investigation against the diseases mentioned.  相似文献   

14.
Three new metabolites, including a cyclic tetrapeptide asperhiratide (1), an ecdysteroid derivative asperhiratine (2), and a sesquiterpene lactone asperhiratone (3), were isolated and identified from the soft coral-derived fungus Aspergillus hiratsukae SCSIO 5Bn1003, together with 10 known compounds. Their structures were elucidated via spectroscopic analysis, X-ray diffraction analysis, and electronic circular dichroism calculations. In addition, the absolute configuration of 1 was determined by Marfey’s technique and an analysis of the acid hydrolysates using a chiral phase HPLC column. Among all the compounds, 6 and 8 showed medium cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), with IC50 values ranging from 31.03 ± 3.04 to 50.25 ± 0.54 µM. Meanwhile, they strongly inhibited α-glucosidase activities, with IC50 values of 35.73 ± 3.94 and 22.00 ± 2.45 µM, which were close to and even stronger than the positive control acarbose (IC50 = 32.92 ± 1.03 µM). Compounds 6–8 showed significant antibacterial activities against Bacillus subtilis, with MIC values of 10.26 ± 0.76 µM, 17.00 ± 1.25 µM, and 5.30 ± 0.29 µM, respectively. Compounds 9 and 12 exhibited potent radical scavenging activities against DPPH, with IC50 values of 12.23 ± 0.78 µM and 7.38 ± 1.16 µM. In addition, asperhiratide (1) was evaluated for anti-angiogenic activities in the in vivo zebrafish model, which showed a weak inhibitory effect on intersegmental vessel (ISV) formation.  相似文献   

15.
Seventeen lactones including eight territrem derivatives (1–8) and nine butyrolactone derivatives (9–17) were isolated from a marine-derived fungus Aspergillus terreus SCSGAF0162 under solid-state fermentation of rice. Compounds 1–3 and 9–10 were new, and their structures were elucidated by spectroscopic analysis. The acetylcholinesterase inhibitory activity and antiviral activity of compounds 1–17 were evaluated. Among them, compounds 1 and 2 showed strong inhibitory activity against acetylcholinesterase with IC50 values of 4.2 ± 0.6, 4.5 ± 0.6 nM, respectively. This is the first time it has been reported that 3, 6, 10, 12 had evident antiviral activity towards HSV-1 with IC50 values of 16.4 ± 0.6, 6.34 ± 0.4, 21.8 ± 0.8 and 28.9 ± 0.8 μg·mL−1, respectively. Antifouling bioassay tests showed that compounds 1, 11, 12, 15 had potent antifouling activity with EC50 values of 12.9 ± 0.5, 22.1 ± 0.8, 7.4 ± 0.6, 16.1 ± 0.6 μg·mL−1 toward barnacle Balanus amphitrite larvae, respectively.  相似文献   

16.
Four new dimeric sorbicillinoids (1–3 and 5) and a new monomeric sorbicillinoid (4) as well as six known analogs (6–11) were purified from the fungal strain Hypocrea jecorina H8, which was obtained from mangrove sediment, and showed potent inhibitory activity against the tea pathogenic fungus Pestalotiopsis theae (P. theae). The planar structures of 1–5 were assigned by analyses of their UV, IR, HR-ESI-MS, and NMR spectroscopic data. All the compounds were evaluated for growth inhibition of tea pathogenic fungus P. theae. Compounds 5, 6, 8, 9, and 10 exhibited more potent inhibitory activities compared with the positive control hexaconazole with an ED50 of 24.25 ± 1.57 µg/mL. The ED50 values of compounds 5, 6, 8, 9, and 10 were 9.13 ± 1.25, 2.04 ± 1.24, 18.22 ± 1.29, 1.83 ± 1.37, and 4.68 ± 1.44 µg/mL, respectively. Additionally, the effects of these compounds on zebrafish embryo development were also evaluated. Except for compounds 5 and 8, which imparted toxic effects on zebrafish even at 0.625 μM, the other isolated compounds did not exhibit significant toxicity to zebrafish eggs, embryos, or larvae. Taken together, sorbicillinoid derivatives (6, 9, and 10) from H. jecorina H8 displayed low toxicity and high anti-tea pathogenic fungus potential.  相似文献   

17.
The Ascomycota Dichotomomyces cejpii was isolated from the marine sponge Callyspongia cf. C. flammea. A new gliotoxin derivative, 6-acetylmonodethiogliotoxin (1) was obtained from fungal extracts. Compounds 2 and 3, methylthio-gliotoxin derivatives were formerly only known as semi-synthetic compounds and are here described as natural products. Additionally the polyketide heveadride (4) was isolated. Compounds 1, 2 and 4 dose-dependently down-regulated TNFα-induced NF-κB activity in human chronic myeloid leukemia cells with IC50s of 38.5 ± 1.2 µM, 65.7 ± 2.0 µM and 82.7 ± 11.3 µM, respectively. The molecular mechanism was studied with the most potent compound 1 and results indicate downstream inhibitory effects targeting binding of NF-κB to DNA. Compound 1 thus demonstrates potential of epimonothiodiketopiperazine-derived compounds for the development of NF-κB inhibitors.  相似文献   

18.

Background:

β-thalassemia is the most common monogenic disorder in human. The (CT) polymorphism at -158 upstream region of the γG-globin gene and pharmacological factors such as hydroxyurea have been reported to influence γ-globin gene expression and the severity of clinical symptoms of β-thalassemia.

Methods:

In the present study, 51 β-thalassemia intermediate patients were studied. Xmn1γG polymorphism genotype was determined using Tetra-Primer ARMS-PCR technique. Hemoglobin (Hb) and fetal hemoglobin (HbF) levels were determined by gel electrophoresis.

Results:

Of 51 patients, 35 (68.6%) patients were heterozygous (CT) and 16 (31.4%) patients were homozygous (CC). Of 30 patients under treatment by hydroxyurea, 20 (66.7%) patients were heterozygous (CT) and 10 (33.3%) patients were homozygous (CC). Our results demonstrated that in the heterozygous (CT) genotype, the Hb (9.58 ± 1.25 gm/dl) and HbF (89.30 ± 21.87) levels were significantly higher in comparison with homozygous (CC) genotype (7.94 ± 1.34 gm/dl and 70.32 ± 40.56, respectively). Furthermore, we observed that after drug usage, the Hb and HbF levels in patients with heterozygous (CT) genotype (0.7 ± 1.26 gm/dl and 5.95±14.8, respectively) raised more in comparison with homozygous (CC) genotype (0.26 ± 1.43 gm/dl and 0.8 ± 1.31, respectively).

Conclusion:

Hb and HbF levels in the patients carrying T allele are increased significantly, and they also response to hydroxyurea treatment.Key Words: Fetal hemoglobin (HbF), Hydroxyurea, Intermediate β-thalassemia  相似文献   

19.
The aim of our study was to assess the combined impact of UVR (280–400 nm) and temperature on the first larval stage (Zoea I) of three crab species from the Patagonian coast: Cyrtograpsus altimanus, C. angulatus, and Leucippa pentagona. We determined the survival response of newly hatched Zoea I after being exposed for 8–10 h under a solar simulator (Hönle SOL 1200) at 15 and 20 °C. There was no mortality due to Photosynthetic Active Radiation (PAR, 400–700 nm) or ultraviolet-A radiation (UV-A, 315–400 nm), and all the observed mortality was due to ultraviolet-B radiation (UV-B, 280–315 nm). The data of larval mortality relative to exposure time was best fit using a sigmoid curve. Based on this curve, a threshold (Th) and the lethal dose for 50% mortality (LD50) were determined for each species. Based on the Th and LD50, C. altimanus was found to be the most resistant species, while L. pentagona was found to be the most sensitive to UV-B. For both species of Cyrtograpsus, mortality was significantly lower at 20 °C than at 15 °C; however, no significant differences between the two temperature treatments were found in L. pentagona. Bioaccumulation of UV-absorbing compounds in the gonads and larvae of C. altimanus, and to a lesser extent in C. angulatus, might have contributed for counteracting the impact of UV-B. However, most of the resilience to UV-B observed with the increase in temperature might be due to an increase in metabolic activity caused by a repair mechanism mediated by enzymes.  相似文献   

20.
Eight trichothecenes, including four new compounds 1–4 and four known entities 5–8, together with one known cyclonerane (9) were isolated from the solid-state fermentation of Trichoderma brevicompactum NTU439 isolated from the marine alga Mastophora rosea. The structures of 1–9 were determined by 1D/2D NMR (nuclear magnetic resonance), MS (mass spectrometry), and IR (infrared spectroscopy) spectroscopic data. All of the compounds were evaluated for cytotoxic activity against HCT-116, PC-3, and SK-Hep-1 cancer cells by the SRB assay, and compound 8 showed promising cytotoxic activity against all three cancer cell lines with the IC50 values of 3.3 ± 0.3, 5.3 ± 0.3, and 1.8 ± 0.8 μM, respectively. Compounds 1–2, 4–6, and 7–8 potently inhibited LPS-induced NO production, and compounds 5 and 8 showed markedly inhibited gelatinolysis of MMP-9 in S1 protein-stimulated THP-1 monocytes.  相似文献   

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