RÉSUMÉ
BACKGROUND@#With increasing media coverage of food safety incidents, such as that of clenbuterol residues in pork, food safety has become a major public health concern in China. Rapidly developing online markets attract increasing numbers of Chinese consumers to purchase food on the Internet. However, the quality and safety of food sold online are uncertain and are less reported on.@*OBJECTIVE@#This research aimed to systematically study the quality and safety of chilled pork from wet markets, supermarkets, and online markets in China.@*RESULTS@#The chilled pork samples from online markets were fresher than those from wet markets and supermarkets based on the surface redness (a* value). Chilled pork contained high levels of nutritional elements, especially the magnesium and phosphorus levels in samples from online markets. The levels of heavy metal element residues and veterinary drug residues in all chilled pork samples were within the standards limits. In addition, huge differences existed in the quality and freshness of the chilled pork samples from online markets according to principal component analysis (PCA).@*CONCLUSIONS@#Most chilled pork sold in Chinese markets was qualified and safe. It is necessary to establish an effective online market supervision system for chilled pork.
Sujet(s)
Animaux , Chine , Basse température , Résidus de médicaments/analyse , Conservation aliments/normes , Qualité alimentaire , Sécurité des aliments , Métaux lourds/analyse , Analyse en composantes principales , Viande rouge/normes , Sus scrofa , Médicaments vétérinaires/analyseRÉSUMÉ
OBJECTIVE@#To study the effect of soothing liver, relieving depression, invigorating spleen and reinforcing blood on reducing delirium in elderly patients with hip fracture.@*METHODS@#From December 2014 to June 2018, 180 elderly patients with hip fracture admitted were divided into treatment group and placebo group according to the order of admission:90 patients in treatment group were treated with Jiawei Xiaoyao Powder(JWXYP), including 32 males and 58 females, with an average age of(72.12±4.92), involving 67 cases of femoral trochanter fractures and 23 cases of femoral neck fractures; 35 cases underwent dynamic hip screw fixation, 31 cases underwent intramedullary fixation and 24 cases underwent artificial hip replacement. In the placebo group, 90 patients were treated with placebo, including 37 males and 53 females, with an average age of(72.91±5.43) years old, involving 69 cases of femoral trochanteric fractures and 21 cases of femoral neck fractures, including 37 cases underwent dynamic hip screw fixation, 30 cases underwent intramedullary fixation and 23 cases underwent artificial hip replacement. The age, sex, injury site, intraoperative bleeding volume, postoperative drainage, operation time, anesthesia time, post-operative pain score, post-operative hemoglobin, post-operative CRP, delirium severity(DRS) score and delirium occurrence were observed and compared between the two groups.@*RESULTS@#All patients were followed up until delirium returned to normal, postoperative delirium was found in 12 cases (13.33%) in the treatment group and in 39 cases(43.33%) in the placebo group, the treatment group was significantly better than the placebo group. The monitoring indexes of the two groups were compared:post-operative pain score(=0.002), post-operative hemoglobin(=0.012), post-operative CRP(=0.042).@*CONCLUSIONS@#JWXYP can relieve liver depression, invigorate spleen and invigorate blood circulation, reduce pain, inflammatory stimulation and supplement blood volume after operation, and significantly reduce the incidence of delirium after operation.
Sujet(s)
Sujet âgé , Femelle , Humains , Mâle , Délire avec confusion , Médicaments issus de plantes chinoises , Utilisations thérapeutiques , Ostéosynthèse interne , Fractures de la hanche , Chirurgie générale , Résultat thérapeutiqueRÉSUMÉ
OBJECTIVE@#Apios americana, a plant used as a staple ingredient of native American diets, has various properties, including anti-cancer, anti-hyperglycemic, hypotensive, and anti-inflammatory activity. In Japan, Apios is used as a post-natal medication. After parturition, women undergo a period of recovery as they return to pre-pregnancy conditions. However, few health products that aid post-partum recovery are on the market. We explored whether Apios can accelerate the post-partum recovery process, in particular the involution of the uterus.@*METHODS@#Female rats kept in individual cages were mated with two male rats, with the exception of the control group (female rats without mating, on basal diet; n=6). After delivery, rats were divided into five groups based on their diet: basal diet (model; n=6); basal diet+oral intake at 5.4 g/kg of Chanfukang granules (a Chinese patent medicine preparation for post-partum lochia) (positive; n=6); basal diet containing 10% Apios powder (low; n=6); basal diet containing 20% Apios powder (medium; n=6); basal diet containing 40% Apios powder (high; n=6). Five days later, uteri and spleens were weighed. Uterus and spleen indices for each rat were calculated by dividing visceral weight by the total weight. Hormone and cytokine concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Histological analysis of uteri was completed using hematoxylin and eosin (H&E) staining. Expression of matrix metalloproteinases and inhibitors in uteri was measured by western blotting.@*RESULTS@#Our results showed that Apios treatment reduced the post-partum uterus index and regulated the hormone concentrations. Moreover, we found that the process of uterine involution was accelerated, based on morphological changes in the uterus. In addition, our results indicated that Apios alleviated the inflammatory response induced by the involution process. Transforming growth factor β was also found to be regulated by Apios. There were significant downregulation of matrix metalloproteinases and upregulation of their inhibitors by Apios, which suggested that Apios increased the rate of the collagen clearance process.@*CONCLUSIONS@#These results, based on experimental observations at the molecular and protein levels, verified our hypothesis that Apios can improve uterine involution, and demonstrated the potential application of Apios in post-partum care.
RÉSUMÉ
<p><b>OBJECTIVE</b>To discusses the clinical effects of arthroscopy combined with minimally invasive percutaneous plate osteosynthesis(MIPPO) technology in treating Schatzker IV tibial plateau fractures.</p><p><b>METHODS</b>From January 2012 to January 2016, 19 patients with Schatzker type IV tibial plateau fractures were treated with arthroscopy combined with minimally invasive technique including 12 males and 7 females with an average age of 46.5 years old ranging from 19 to 78 years old. Patients were suffering knee pain, swelling, flexion and extension limited, and other symptoms preoperative. Patients were followed up and assessed by Rasmussen knee function score.</p><p><b>RESULTS</b>No infection, traumatic arthritis, and knee joint valgus occurred after operation. Nineteen cases were followed up for 12 to 24 months with an average of 18.6 months. Fracture healing time was 3 to 5 months with an average of 3.8 months. The knee pain and limited mobility improved significantly. The range of autonomic movement of joints was from 90 to 136 degrees. According to Rasmussen functional score criteria, the total score was 27.00±2.49, the result was excellent in 16 cases, good in 2 cases, fair in 1 case.</p><p><b>CONCLUSIONS</b>Arthroscopic treatment for Schatzker type IV tibial plateau fractures combined with MIPPO can simultaneously treat internal structural injuries such as meniscus and other knee joints, with less trauma, fewer complications, and faster joint function recovery, but we must strictly grasp surgical indications and avoid expanding injuries.</p>
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To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.
Sujet(s)
Humains , Cellules cultivées , Technique de coulée dentaire , Hépatocytes/effets des médicaments et des substances chimiques , Nanoparticules métalliques/toxicité , Argent/toxicité , Tests de toxicitéRÉSUMÉ
<p><b>OBJECTIVE</b>To investigate the feasibility of using percutaneous K-wires fixation after manipulative reduction combining with gypsum or splint fixation for treatment of the Barton fracture of aged people.</p><p><b>METHODS</b>From June 2011 to May 2013, 91 patients with closed and fresh Barton fracture were analyzed retrospectively which information was complete. According to different methods these patients were divided into three groups: 33 patients in group A were treated by simplex fixation of gypsum or splint after manipulative reduction, including 20 males and 13 females with an average age of (63.27 ± 5.83) years old; 35 patients in group B were treated by percutaneous K-wires fixation after manipulative reduction combining with gypsum or splint fixation, including 23 males and 12 females with an average age of (64.25 ± 4.53) years old; 23 patients in group C were treated by open reduction and internal fixation including 15 males and 8 females with an average age of (64.04 ± 4.83) years old.</p><p><b>RESULTS</b>All the patients were followed up for 10 to 16 months with an average of 12 months by the method of recheckging in outpatient clinic. According Dienst scoring system: in group A, the result was excellent in 15 cases, good in 7 cases, fair in 11 cases; in group B, excellent in 25 cases, good in 6 cases, fair in 4 cases; in group C, excellent in 16 cases, good in 5 cases, fair in 2 cases. The excellent and good rate of group C was better than that of group B and A, further more group B is better than group A. According to X- ray standard, in group A, 26 patients were acceptable, 7 patients were unacceptable; in group B,28 patients were acceptable, 7 patients were uacceptable; in group C, 19 patients were acceptable,4 patients were unacceptable; there were no statistical significant difference (P > 0.05). There were 18 patients with emerging recrispation in group A, 10 patients in group B, 6 patients in group C, the result of group B and C was better than that of group A, and there was no statistically significant between group B and C (P > 0.05).</p><p><b>CONCLUSION</b>Using percutaneous K-wires fixation after manipulative reduction combining with gypsum or splint fixation for treatment of the Barton fracture of aged people is an effective method, it has advantages of micro-invasived, reliable fixation, less complication, not need to fix wrist joint and early functional exercise.</p>
Sujet(s)
Sujet âgé , Femelle , Humains , Mâle , Adulte d'âge moyen , Fils métalliques , Manipulation orthopédique , Méthodes , Fractures du radius , Thérapeutique , Études rétrospectives , AttellesRÉSUMÉ
<p><b>OBJECTIVE</b>To discuss the clinical significance of the reduction and fixation for femoral lesser trochanteric fragment in treating the femoral comminuted intertrochanteric fractures.</p><p><b>METHODS</b>From January 2012 to December 2013,32 patients with intertrochanteric fractures were treated by surgery, and self-designed reduction fixators were used in the patients for the fixation of lesser trochanter of femur. There were 11 males and 21 females, ranging in age from 45 to 81 years old with an average of 64 years old. According to the Evans typing, 12 cases were type II, 13 cases were type III and 7 cases were type IV. Simple lag screw fixed in 19 cases and steel wire fixed in 13 cases. Hip joint function was evaluated according Harris score and the complications such as coxa adducta,cutting of femoral head and neck,implants breakage were observed.</p><p><b>RESULTS</b>Thirty-two patients were followed up from 9 to 24 months with an average of 13 months. Coxa adducta occurred in 1 case,no cutting of femoral head and neck occurred and implants breakage were found. The mean Harris score was 91.80 ± 3.05 in 32 patients.</p><p><b>CONCLUSION</b>The reconstruction and fixation for the posterior medial bone cortex continuity is a key factor on affect the stability of femoral intertrochanteric fracture. Self-designed reduction fixators can effective reduce and fix the lesser trochanter of femur, it has advantage of fast reduction and fixation, and simple operation.</p>
Sujet(s)
Sujet âgé , Sujet âgé de 80 ans ou plus , Femelle , Humains , Mâle , Adulte d'âge moyen , Conception d'appareillage , Ostéosynthèse interne , Fractures de la hanche , Chirurgie généraleRÉSUMÉ
The synthetic biology matures to promote the heterologous biosynthesis of the well-known drug paclitaxel that is one of the most important and active chemotherapeutic agents for the first-line clinical treatment of cancer. This review focuses on the construction and regulation of the biosynthetic pathway of paclitaxel intermediates in both Escherichia coli and Saccharomyces cerevisiae. In particular, the review also features the early efforts to design and overproduce taxadiene and the bottleneck of scale fermentation for producing the intermediates.
Sujet(s)
Alcènes , Chimie , Métabolisme , Antinéoplasiques d'origine végétale , Chimie , Métabolisme , Voies de biosynthèse , Diterpènes , Chimie , Métabolisme , Escherichia coli , Métabolisme , Fermentation , Génie métabolique , Paclitaxel , Chimie , Métabolisme , Promédicaments , Saccharomyces cerevisiae , Métabolisme , Biologie synthétiqueRÉSUMÉ
<p><b>OBJECTIVE</b>To investigate the operative management and surgical techniques for lumber disc herniation (LDH) in aged patients (>or=65 years).</p><p><b>METHODS</b>From 2005 to 2010,the data of 43 patients with LDH underwent surgical treatment were retrospectively analyzed. There were 25 males and 18 females,aged from 65 to 70 years old with an average of 67.6 years. The course of disease was from 6 weeks to 7 years with an average of 10.2 years. Fenestratiodn discectomy or extended fenestration discectomy and unilateral or bilateral fenestration were used according to the conditions of location,type of herniated macleos polposus and nerve root compression. Among the patients,the nerve root canal was enlarged,hyperplastic osteophyma and soft tissue were removed, bilateral articular process was reserved in order to maintain the stability of the lumbar segment.</p><p><b>RESULTS</b>All the patients were followed up from 1.2 to 5.2 years. According to the criteria of HU you-gu, 25 cases got excellent results, 15 good, 2 fair and 1 poor. No infection or nerve injury was found. Nerve function of patients had a normal or near normal recovery.</p><p><b>CONCLUSION</b>For the treatment of LDH in aged patents,it is key that reasonably choose the operative method, completely remove the hyperplasy of diseased region and enlarge the nerve root canal, thoroughly loose the nerve root.</p>
Sujet(s)
Sujet âgé , Femelle , Humains , Mâle , Déplacement de disque intervertébral , Chirurgie générale , Vertèbres lombales , Chirurgie générale , Études rétrospectivesRÉSUMÉ
<p><b>OBJECTIVE</b>To investigate the application of transpedicular porking repositor, thread device and transpedical interbody bone grafting apparatus in the treatment of thoracolumbar spinal fracture.</p><p><b>METHODS</b>From March 2008 to March 2011, 17 males and 15 females with thoracolumbar spinal fracture were treated by using self-designed transpedicular porking reposito, thread device and transpedical interbody bone grafting apparatus. The average age was 39.4 years (ranged from 25 to 65 years). All the cases were checked by X-ray and CT before and one week, one year after operation, removal of internal fixation. The angle of injured vertebral sagittal, cobbs angle and injured vertebral height were measured.</p><p><b>RESULTS</b>All patients were followed up, and the duration ranged for 14 to 21 months (averaged 16 months). The content of following up included loss of ithycyphos and height of spinal, fracture healing and implant fixation. Nerve vascular complication caused by implantation didn't occurred; interverbral body fusion was good. The results preoperative, 1 week and year postoperative and 3 months after taking out the internal fixation showed injured spinal height maintained well, loss and collapse of height and angle did not occurred.</p><p><b>CONCLUSION</b>Treating thoracolumbar spinal fracture can obtained satisfactory effects by using transpedicular porking repositor, thread device and transpedical interbody bone grafting apparatus. It has advantages of minimal invasive, and can promote fracture healing earlier, recover spinal height, rebuild stability of spinal, prevent loss and collapse of vertebral body height to avoid anterior lumbar surgery on the late stage.</p>
Sujet(s)
Adulte , Sujet âgé , Femelle , Humains , Mâle , Adulte d'âge moyen , Transplantation osseuse , Ostéosynthèse interne , Vertèbres lombales , Plaies et blessures , Chirurgie générale , Fractures du rachis , Chirurgie générale , Vertèbres thoraciques , Plaies et blessures , Chirurgie généraleRÉSUMÉ
<p><b>OBJECTIVE</b>To explore operative method for the treatment of double injuries of superior shoulder suspensory complex (SSSC).</p><p><b>METHODS</b>From January 2008 to March 2010,11 patients wiht SSSC injuries were treated, including 9 males and 2 females with an average age of 38 years (ranged from 20 to 47 years). The patients were treated with 4 methods as follows: 4 patients with fractures of neck of scapula combined with homolateral fracture of clavicle were treated with reconstituted plates; 2 patients with fractures of coracoid process or disruption of coracoclavicular ligament combined with the fracture of extremitas acromialis claviculae or acromioclavicular dislocation were treated with clavicular hook plates and cannulated compression screws; 3 patients with injuries of basilar part of acromial process combined with the glenoid cavity and acromioclavicular articulation were treated with reconstuction plates and clavicular hook plates; 2 patients with fractures of acromial process combined with acromioclavicular dislocation and the fracture of lateral third of clavicle were treated with small "T" plates and clavicular hook plates.</p><p><b>RESULTS</b>Among 11 patients, 9 patients were followed up with an average duration of 9.2 months (ranged from 6 to 12 months). All the fractures were healed without bone nonunion or failure of internal fixators. The average union time was 2.6 months. The profile of articulatio capitis humeri was normal and hibateral articulatio capitis humeri was symmetrical without crispation, descensus, adduct and adtorsion of articulatio capitis humeri or other abnormity. According to the Constant-Murley evaluation system, the score ranged from 69 to 100, with an average of 89.7, which included average pain score of 10 to 15, daily activities score of 14 to 20, myodynamia score of 15 to 25, territory score of 34 to 40.</p><p><b>CONCLUSION</b>The double injuries of SSSC should be treated by types to recover the integrity and constancy of SSSC.</p>
Sujet(s)
Adulte , Femelle , Humains , Mâle , Adulte d'âge moyen , Articulation acromioclaviculaire , Plaies et blessures , Luxation de l'épaule , Chirurgie générale , Articulation glénohumérale , Plaies et blessuresRÉSUMÉ
<p><b>OBJECTIVE</b>To explore the diagnosis and treatment of tarsometatarsal joint complex injury (TJC).</p><p><b>METHODS</b>From January 2007 to January 2009,16 patients with tarsometatarsal joint complex injury were treated with open reduction and internal fixation. There were 12 males and 4 females, ranging in age from 21 to 45 years with an average of 34.1 years. Seven cases were left and 9 cases were right and all injuries caused by direct violence. Four cases caused by traffic accident 5 by fall from high and 7 by crush injury. Intercuneiform dislocation were in 11 cases, naviculocuneiform joint dislocation in 3 cases and cuboid fracture in 2 cases. All the cases were three column injuries. According to the situation of exploring and the stability, screw fixation was used for intertarsal joint, internal and middle column tarsometatarsal joint, the Kirschner wire fixation for external column and miniature plate fixation for comminuted fracture of metatarsal bones and compressible fracture of cuboid. The criteria of the AOFAS Foot and Ankle Surgery by the United States Association of ankle-rear foot functional scale was used to evaluate the clinical effect.</p><p><b>RESULTS</b>All the patients were followed up,the duration ranged from 6 to 18 months(averaged 12.6 months). According to the score system of AOFAS,the total score was (74.6+/-10.4 ) points, including pain items of (29.3+/-5.9), the score of functional items of (32.4+/-5.6) points, and power lines of (12.9+/-2.6). All the incisions were primarily healed without infection, skin necrosis,fixture broken or loosen. Three cases received arthrodesis due to osteoarthritis. Four cases were followed up continually because they only had the radiologic osteoarthritis without pain.</p><p><b>CONCLUSION</b>Anatomical reduction and stable fixation is the key point of the treatment of tarsometatarsal joint complex injury. Open reduction and internal fixation at the first stage is good for secondary arthrodesis.</p>
Sujet(s)
Adulte , Femelle , Humains , Mâle , Adulte d'âge moyen , Ostéosynthèse interne , Os du métatarse , Plaies et blessures , Chirurgie générale , Articulations du tarse , Plaies et blessures , Chirurgie généraleRÉSUMÉ
<p><b>OBJECTIVE</b>To evaluate the therapy and the key points of the tarsometatarsal joint injury combined with metatarsal fracture.</p><p><b>METHODS</b>From Jan. 2006 to Jul. 2008,19 patients with tarsometatarsal joint injury combined with metatarsal fracture were treated with opened reduction and internal fixation of Kirschner wire or screws, included 13 males and 6 females with an average age of 38.1 years ranging from 21 to 56 years. The classification of tarsometatarsal joint injury showed that there were 2 cases of inner column injury, 5 cases of inner and medial column injury, 3 cases of lateral and medial column injury, 9 cases of tri-column injury. There were 8 cases of shaft fracture, 7 of neck fracture, 19 of foundation fracture.</p><p><b>RESULTS</b>All the incisions were first stage healed without skin necrosis. The healing time of fracture was 11.2 weeks on average. All the patients were followed-up for 6 to 17 months with an average of 12.8 months. According to the standard of AOFAS, the average score was (84.500 +/- 8.553), the results were excellent in 4 cases, good in 9 cases, fair in 3, and poor in 3. The regular daily life was recovered after 6.4 months, 3 patients suffer from mild osteoarthritis.</p><p><b>CONCLUSION</b>No matter which fixed mode was used, the anatomical reduction was the most important to rebuild arches of the foot and recover medial longitudinal and lateral arch. Rebuilding arches of the foot guaranteed the integrity of the stress point scaffold and avoided the pain and limp. The anatomical reduction of tarsometatarsal joint and metatarsal was also important to rebuild the function of foot.</p>
Sujet(s)
Adulte , Femelle , Humains , Mâle , Adulte d'âge moyen , Jeune adulte , Articulations du pied , Plaies et blessures , Chirurgie générale , Ostéosynthèse interne , Méthodes , Fractures osseuses , Chirurgie générale , Os du métatarse , Plaies et blessures , Chirurgie générale , Récupération fonctionnelleRÉSUMÉ
Influenza A/H1N1 virus-encoded nonstructural, or NS1, protein inhibits the 3'-end processing of cellular pre-mRNAs by binding the cellular protein: the 30-kDa subunit of CPSF (cleavage and polyadenylation specificity factor, CPSF30). CPSF30 binding site of the NS1 protein is a potential target for the development of drugs against influenza A/H1N1 virus. A yeast two-hybrid screening system was constructed and used for screening Chinese medicines that inhibit the interaction of the A/H1N1 flu NS1 protein and human CPSF30 protein. The NS1 gene of A/H1N1 virus was amplified by consecutive polymerase chain reaction (PCR), and the human CPSF30 gene of HeLa cell cloned by reverse transcriptase-polymerase chain reaction (RT-PCR). Then the two gene fragments confirmed by sequencing were subcloned into the yeast expression vectors pGBKT7 and pGADT7, respectively. The two constructs, bait vector pGBKNS1 and prey vector pGADCPSF, were co-transformed into yeast AH109. The eight individual yeast colonies were picked and subjected to verification by PCR/gel electrophoresis. The inhibition of the NS1-CPSF30 interaction was allowed the identification of selective inhibitors. The four of more than thirty identified Chinese medicines, including 'Shuanghuanglian oral liquid', showed the strong inhibition of the NS1-CPSF30 interaction.
Sujet(s)
Humains , Séquence nucléotidique , Sites de fixation , Facteur de spécificité de clivage et polyadénylation , Génétique , Métabolisme , Médicaments issus de plantes chinoises , Pharmacologie , Amplification de gène , Cellules HeLa , Sous-type H1N1 du virus de la grippe A , Génétique , Fragments peptidiques , Génétique , Plasmides , Liaison aux protéines , Transformation génétique , Techniques de double hybride , Protéines virales non structurales , Génétique , MétabolismeRÉSUMÉ
<p><b>OBJECTIVE</b>To analyze the reason of error diagnosis and inappropriate treatment of radius head fractures complicating distal radioulnar joint dislocation (Essex-Lopresti injury) and to seek for the reasonable treatment.</p><p><b>METHODS</b>From 2008 to 2009, 2 male patients of radius head fractures complicating distal radioulnar joint dislocation were treated, the age was 56 and 66 years old respectively. The symptom included elbow swelling and limitation of forearm rotation. X-ray showed comminuted fractures of capitulum radius. There were 1 case of Mason type III and 1 cases of type IV. Two patients were treated by resection of capitulum radius and plaster fixation after operation.</p><p><b>RESULTS</b>Both of the 2 cases had limited rotation of forearm and the distal radioulnar joint pain. The X-ray showed that the distal radioulnar joint was separated obviously and the proximal radius was translocated.</p><p><b>CONCLUSION</b>The early diagnosis is very important for the Essex-Lopresti injury. Rebuilding the longth of the radius and reduction fixating the distal radioulnar joint after fixated is an effective treatment while the interosseous membranes can't be repaired and rebuilded.</p>
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Sujet âgé , Humains , Mâle , Adulte d'âge moyen , Erreurs de diagnostic , Articulation du coude , Plaies et blessures , Luxations , Diagnostic , Thérapeutique , Fractures du radius , Fractures de l'ulnaRÉSUMÉ
A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% (v/v), age of inoculum of 16 h, and cultivation at 23 degrees C. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2, therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production.
Sujet(s)
Acides aminés , Bacillus subtilis , Génétique , Métabolisme , Milieux de culture , Concentration en ions d'hydrogène , Kératines , Métabolisme , Mutation , Peptide hydrolasesRÉSUMÉ
The aim of this study was to purify and characterize a keratinase produced by a new isolated Bacillus subtilis KD-N2 strain. The keratinase produced by the isolate was purified using ammonium sulphate precipitation, Sephadex G-75 and DEAE (diethylaminoethyl)-Sepharose chromatographic techniques. The purified enzyme was shown to have a molecular mass of 30.5 kDa, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The optimum pH at 50 degrees C was 8.5 and the optimum temperature at pH 8.5 was 55 degrees C. The keratinase was partially inactivated by some metal ions, organic solvents and serine protease inhibitor phenylmethanesulfonyl fluoride (PMSF). Sodium dodecyl sulfate (SDS) and ethylene diamine tetraacetic acid (EDTA) had positive effect on the keratinase activity. Reducing agents including dithiothreitol (DTT), mercaptoethanol, L-cysteine, sodium sulphite, as well as chemicals of SDS, ammonium sulfamate and dimethylsulfoxide (DMSO) stimulated the enzyme activity upon a feather meal substrate. Besides feather keratin, the enzyme is active upon the soluble proteins ovalbumin, bovine serum albumin (BSA), casein and insoluble ones as sheep wool and human hair. Calf hair, silk and collagen could not be hydrolyzed by the keratinase.
Sujet(s)
Bacillus subtilis , Classification , Activation enzymatique , Stabilité enzymatique , Peptide hydrolases , Chimie , Spécificité d'espèce , Spécificité du substratRÉSUMÉ
<p><b>OBJECTIVE</b>Cloning and bioinformatics analysis of P450 cDNA in Artemisia annua.</p><p><b>METHOD</b>A P450 cDNA gene was cloned from A. annua by RT-PCR. The bioinformatics analysis of the P450 gene was performed.</p><p><b>RESULT</b>The complete ORF of this P450 cDNA is 1 464 bp and encodes 488 aa. The sequence was reported to GenBank and coded as DQ667171. Bioinformatics analysis of the P450 cDNA showed it encoded an A-type P450 protein with 54. 992 kDa, it's isoelectric point was 8.83 and the possibility of export to mitochondria was 0.893 2.</p><p><b>CONCLUSION</b>The comparable analysis of the P450 with CYP71AV1 revealed that the two proteins probably performed the same function because of the similar character.</p>
Sujet(s)
Séquence d'acides aminés , Artemisia annua , Génétique , Séquence nucléotidique , Clonage moléculaire , Cytochrome P-450 enzyme system , Classification , Génétique , ADN complémentaire , Chimie , Génétique , Données de séquences moléculaires , Cadres ouverts de lecture , Génétique , Phylogenèse , Protéines végétales , Génétique , Plantes médicinales , Génétique , RT-PCR , Analyse de séquence d'ADN , Similitude de séquences d'acides aminésRÉSUMÉ
The gene encoding amorpha-4, 11-diene synthase was cloned from Artemisia annua L. Other two genes encoding the FPP synthase (FPPS) and HMG-CoA reductase (HMGR) were cloned from Saccharomyces cerevisiae. The cloned cDNAs were confirmed by DNA sequencing. Two expression vectors were constructed, one is named pGBT9/A/HMG/FPP harboring genes for HMG-CoA reductase and FPP synthase and the other is pYeDP60/G/AS, containing the gene encoding amorpha-4,11-diene synthase. Two kinds of engineered yeast were constructed: the first was named WHT [AS], which contained the plasmid pYeDP60/G/AS; the second was WHT [HMG + FPP + AS], in which the vectors pGBT9/A/ HMG/FPP and pYeDP60/G/AS were introduced by cotransformation mediated with LiOAc and PEG4000. The positive clones were identified for further fermentations. The samples from fermentations were analyzed by GC-MS for amorpha-4,11-diene. The results show that engineered yeasts could produce amorpha-4,11-diene. Moreover, the amorpha-4,11-diene production of WHT[ HMG + FPP + AS] and WHT[ AS] were 23.6 mg x L(-1) and 10 microg x L(-1), respectively. Its concentrations were reported as equivalents of valencene. The results showed the copy number increase of HMGR and FPPS genes can improve the production of amorpha-4, 11-diene in the fermentation of engineered yeasts.