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1.
J Intell ; 11(5)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37233346

RESUMO

An accumulating body of literature points to a link between spatial reasoning and mathematics learning. The present study contributes to this line of research by investigating sex differences both in spatial representations of magnitude and in the use of arithmetic strategies, as well as the relation between the two. To test the hypothesis that sex differences in spatial-numerical magnitude knowledge mediate sex differences in the use of advanced strategies (retrieval and decomposition), two studies were conducted. Study 1 included 96 US first graders (53% girls); Study 2 included 210 Russian first graders (49% girls). All participants completed a number line estimation task (a spatially based measure of numerical magnitude knowledge) and an arithmetic strategy task (a measure of strategy choice). The studies showed parallel results: boys produced more accurate numerical magnitude estimates on the number line estimation task and used advanced strategies more frequently on the arithmetic task. Critically, both studies provide support for the mediation hypothesis (although there were some differences in the pattern obtained for the two strategies). The results are discussed in the context of broader research about the relation between spatial and mathematical skills.

2.
Health Commun ; 35(11): 1368-1375, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31267794

RESUMO

The positive effects of graphic health warnings (GHWs) on quitting smoking have been widely demonstrated in the literature on cigarette warning. However, recent findings of smoker reactance to GHWs demand investigations of factors that may constrain the effects of GHWs. The current study sought to identify conditions in which GHWs do not have a positive impact on smokers' desire to quit with a focus on smokers' perceived stress. Two hundred and forty-four smokers in South Korea were exposed to either a text-only or a GHW cigarette pack in a between-subjects experiment. Results from this study suggest that the GHW condition is effective in increasing attention to the GHW, enhancing perceived usefulness of information, and desire to quit only among those with low (vs. high) perceived stress. In addition, an interaction effect between warning type and perceived stress on the desire to quit was sequentially mediated by attention and perceived information effectiveness. Based on the results, we suggest that GHWs were less effective for smokers with high levels of perceived stress because their stress appeared to exhaust the cognitive resources necessary to process the information.


Assuntos
Abandono do Hábito de Fumar , Produtos do Tabaco , Humanos , Rotulagem de Produtos , República da Coreia , Fumantes , Fumar , Prevenção do Hábito de Fumar , Estresse Psicológico
3.
Emotion ; 20(4): 525-540, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30896207

RESUMO

Regulating one's emotions is an important psychological skill at all ages. Cognitive reappraisal-changing the meaning of a stimulus to alter its emotional impact-is an effective emotion regulation technique. Prior work shows that adults spontaneously reduce their use of present tense verbs and first-person singular pronouns (e.g., I, me, mine) when engaging in cognitive reappraisal, a linguistic shift that is thought to track increased psychological distance. Here, we investigated whether such linguistic distancing during emotion regulation varied across age. Participants aged 10 to 23 (N = 112) spoke aloud their thoughts and feelings while completing a classic cognitive reappraisal task. Participants' verbal responses were recorded, transcribed, and analyzed for linguistic distancing, compliance with reappraisal instructions, and use of 8 different reappraisal strategies identified by prior researchers. Results replicated prior work in a developmental sample: Reappraisal decreased negative affect and increased linguistic distancing, and stronger linguistic distancing during reappraisal was associated with more successful emotion regulation. Contrary to hypotheses, we found no age differences in linguistic distancing or reappraisal success, even after excluding trials on which participants did not comply with reappraisal instructions. However, reappraisal strategy use varied across age. Use of the changing circumstances and separating oneself (i.e., distancing) strategies increased across age whereas changing consequences use decreased across age. Additionally, in adolescence, challenging reality use was elevated and problem-solving use was reduced compared to other ages. Results suggest that linguistic distancing during emotion regulation is stable from age 10 to 23 but use of cognitive reappraisal strategies differs. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Cognição/fisiologia , Regulação Emocional/fisiologia , Linguística/métodos , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Adulto Jovem
4.
J Korean Assoc Oral Maxillofac Surg ; 44(2): 79-85, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29732313

RESUMO

OBJECTIVES: The aim of this study was to evaluate the effects of herbal extracts on bone regeneration. Two known samples were screened. MATERIALS AND METHODS: We previously established a rat calvaria defect model using a combination of collagen scaffold and herbal extracts. An 8 mm diameter trephine bur with a low-speed dental hand piece was used to create a circular calvaria defect. The experimental group was divided into 4 classifications: control, collagen matrix, Danshen with collagen, and Ge Gan with collagen. Animals in each group were sacrificed at 4, 6, 8, and 10 weeks after surgery, and bone regeneration ability was evaluated by histological examination. RESULTS: Results revealed that both Danshen and Ge Gan extracts increased bone formation activity when used with collagen matrix. All groups showed almost the same histological findings until 6 weeks. However, after 6 weeks, bone formation activity proceeded differently in each group. In the experimental groups, new bone formation activity was found continuously up to 10 weeks. In the Danshen and Ge Gan groups, grafted materials were still present until 10 weeks after treatment, as evidenced by foreign body reactions showing multinucleated giant cells in chronic inflammatory vascular connective tissue. CONCLUSION: Histological analyses showed that Danshen and Ge Gan extractions increased bone formation activity when used in conjunction with collagen matrix.

5.
J Thorac Dis ; 9(10): 3728-3734, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29268380

RESUMO

BACKGROUND: There is a lack of data regarding the incidence and associated factors of pneumothorax following thoracentesis conducted in emergency department (ED) settings. The present study aims to determine the incidence of pneumothorax following thoracentesis in ED settings and evaluate the association of specific demographics, clinical, and procedure factors with thoracentesis-related pneumothorax. METHODS: We retrospectively reviewed the medical records of 3,067 thoracentesis cases in the ED of a tertiary care, university-affiliated hospital between January 2009 and December 2014. To evaluate the factors associated with the occurrence of pneumothorax following thoracentesis, matched controls were used with a case to control ratio of 1:5. RESULTS: Of the 3,067 cases that received thoracentesis, 19 cases of pneumothorax were observed (0.62%). Patients with pneumothorax had significantly lower weight and body mass index (BMI) than those without pneumothorax (51.0 vs. 61.2 kg, 20.0 vs. 22.6; P<0.001, respectively). In the multivariate logistic regression analysis, being underweight, defined as a BMI of <18.5 [OR, 5.2 (95% CI, 1.3-21.2); P=0.021] was significantly associated with the occurrence of pneumothorax. CONCLUSIONS: The incidence of pneumothorax following thoracentesis was very low in the present study. However, clinicians should be aware of the risk of pneumothorax in underweight patients during thoracentesis. Further prospective studies are required to clarify the results of the present study.

6.
J Korean Assoc Oral Maxillofac Surg ; 43(5): 343-350, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29142870

RESUMO

The aim of this study is to introduce a surgical technique that can maintain blood supply to prevent condylar resorption in the extracorporeal reduction of condylar fracture. Neither the medial pterygoid muscle on the ramal bone nor the lateral pterygoid muscle on the condylar fragment was detached after vertical ramal osteotomy. Thus, reduction was performed in the intracorporeal state. Therefore, blood supply was expected to be maintained to the fragments of both the condylar and ramal bones. On postoperative radiographs, the anatomical outline of the fractured condyle was well restored, and the occlusion was stable. In the unilateral case, there were no signs of mandibular condylar resorption until postoperative 3 weeks. In the 2 bilateral cases, condylar displacements with plate fractures and screw loosening were observed at postoperative 1 month or 5 months, but radiodensity at the displaced fracture site increased during the follow-up period. Finally, complete remodeling of the condylar fragments with restored anatomic appearance was observed on 8-month or 2-year follow-up radiographs. All cases exhibited good healing aspects with no signs or symptoms of mandibular condylar dysfunction during the postoperative remodeling period after intracorporeal reduction of condylar fracture.

7.
Headache ; 57(10): 1593-1600, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28653430

RESUMO

OBJECTIVE: This study aimed to evaluate the association between misdiagnosis of spontaneous intracranial hypotension (SIH) and subdural hematoma development. BACKGROUND: Although SIH is more prevalent than expected and causes potentially life-threatening complications including subdural hematoma (SDH), the association between misdiagnosis of SIH and SDH development is not yet evaluated. METHODS: Retrospective observational study was conducted between January 1, 2005, and December 31, 2014. Adult patients with spontaneous intracranial hypotension (age ≥ 18 years) were enrolled. RESULTS: Of the 128 patients with SIH, 111 (86.7%) were in no SDH group and 17 (13.3%) were in SDH group. Their clinical presentation did not show significant different between the two groups, except age, the days from symptom onset to correct diagnosis, and the number of misdiagnoses. Age (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.07-1.23) and the number of times SIH was misdiagnosed (OR, 1.82; 95% CI, 1.03-3.21) were independent risk factors for the development of SDH in SIH patients by multivariate logistic analysis. The clinical outcomes, including length of hospital stay and revisit rate, were similar in the two groups. CONCLUSIONS: The number of times SIH was misdiagnosed was associated with the later development of SDH perhaps because of delay in correct diagnosis of SIH. Clinicians would prevent the later complication of SDH in SIH patients by increasing the awareness and a high index of suspicion of SIH.


Assuntos
Erros de Diagnóstico , Hematoma Subdural/epidemiologia , Hipotensão Intracraniana/diagnóstico , Hipotensão Intracraniana/epidemiologia , Adulto , Fatores Etários , Feminino , Hematoma Subdural/etiologia , Hematoma Subdural/fisiopatologia , Hematoma Subdural/terapia , Humanos , Hipotensão Intracraniana/complicações , Hipotensão Intracraniana/terapia , Tempo de Internação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Readmissão do Paciente , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
8.
J Korean Assoc Oral Maxillofac Surg ; 43(2): 125-133, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28462198

RESUMO

Intramuscular hemangioma (IMH) is a rare vascular disease involving skeletal muscle, comprising only 0.8% of hemangiomas. About 10% to 15% of IMHs occur in the head and neck region, mostly involving the masseter muscle. IMH occurs mostly in childhood, but is often not found until unexpected enlargement, pain, or cosmetic asymmetry occurs in adulthood. Several non-surgical treatments including cryotherapy, sclerosant injection, and arterial ligature have been described, but complete surgical resection is the curative intervention. In this report, we present two rare cases of IMH. One IMH case in a 48-year-old male occurred in the masseter muscle feeding from the transverse facial artery. Embolization of the distal branch of the facial artery was first conducted, and then the buccal mass was removed surgically via the intraoral approach. A second IMH case in a 58-year-old female occurred in the orbicularis oris muscle feeding from the superior labial artery, and the mass was excised surgically without embolization.

9.
J Korean Assoc Oral Maxillofac Surg ; 42(5): 301-306, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27847740

RESUMO

The purpose of this study is to report a rare case of mandibular adenocarcinoma that was diagnosed due to metastasis from the prostate. Numb chin syndrome (NCS), which was associated with this case, is also discussed. Computed tomography (CT) and an intraoral incisional biopsy of the left mandibular area were performed. Urology consultation, hormone therapy, chemotherapy and follow-up radiographic images were administered. Histological examination of the incised specimen revealed moderately differentiated adenocarcinoma. The Gleason score was 8 (primary 4/secondary 4). Immunohistochemical features and radiographic results confirmed the diagnosis of metastasis from prostate adenocarcinoma, moderately differentiated. The patient's prostate-specific antigen (PSA) level was very high. After hormone treatment, the patient's PSA levels dropped gradually. Seventeen months later, in May 2015, the PSA level was elevated. The 18-month follow-up CT image indicated that the patient's condition was aggravated. Docetaxel chemotherapy was started in June 2015 (18 months later), and the sixth cycle of the therapy is in progress. Oral metastases that originate from prostate adenocarcinoma are rare and can induce various periosteal reactions. Hormone therapy, chemotherapy and close follow-up could be additional, appropriate treatment, and were applied in this case. Finally, NCS is a valuable indicator of metastatic disease in the mandible.

10.
J Korean Assoc Oral Maxillofac Surg ; 42(5): 307-314, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27847741

RESUMO

We report a case of retiform hemangioendothelioma (RH) located in the infratemporal fossa and buccal area in a 13-year-old Korean boy. The tumor originated from the sphenoid bone of the infratemporal fossa area and spread into the cavernous sinus, orbital apex, and retro-nasal area with bone destruction of the pterygoid process. Tumor resection was conducted via Le Fort I osteotomy and partial maxillectomy to approach the infratemporal fossa and retro-nasal area. The diagnosis of RH was confirmed after surgery. In the presented patient, surgical excision was incomplete, and close follow-up was performed. There was no evidence of expansion or metastasis of the residual tumor in the 8 years after surgery. In cases of residual RH with low likelihood of expansion and metastasis, even though RH is an intermediate malignancy, close follow-up can be the appropriate treatment choice over additional aggressive therapy. To date, 29 papers and 48 RH cases have been reported, including this case. This case is the second reported RH case presenting as primary bone tumor and the first case originating in the oromaxillofacial area.

11.
Maxillofac Plast Reconstr Surg ; 38(1): 16, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27073798

RESUMO

BACKGROUND: The association of biomaterial combined with repair factor-like platelet-rich plasma (PRP) has prospective values. Bovine-derived xenograft has been identified as an osteoconductive and biocompatible grafting material that provides osseointegration ability. PRP has become a valuable adjunctive agent to promote healing in a lot of dental and oral surgery procedures. However, there are controversies with respect to the regenerative capacity of PRP and the real benefits of its use in bone grafts. The purpose of this study was to assess the influence of PRP combined with xenograft for the repair of peri-implant bone defects. METHODS: Twelve rabbits were used in this study, and the experimental surgery with implant installation was performed simultaneously. Autologous PRP was prepared before the surgical procedure. An intrabony defect (7.0 mm in diameter and 3.0 mm deep) was created in the tibia of each rabbit; then, 24 titanium dental implants (3.0 mm in diameter and 8.5 mm long) were inserted into these osteotomy sites. Thus, a standardized gap (4.0 mm) was established between the surrounding bony walls and the implant surface. The gaps were treated with either xenograft alone (control group) or xenograft combined with PRP (experimental group). After healing for 1, 2, 3, 4, 5, and 6 weeks, the rabbits were sacrificed with an overdose of KCl solution. Two rabbits were killed at each time, and the samples including dental implants and surrounding bone were collected and processed for histological analysis. RESULTS: More newly formed bone and a better bone healing process were observed in control group. The histomorphometric analysis revealed that the mean percentage of bone-to-implant contact in the control group was significantly higher than that of the experimental group (25.23 vs. 8.16 %; P < 0.05, independent-simple t test, analysis of variance [ANOVA]). CONCLUSIONS: The results indicate that in the addition of PRP to bovine-derived xenograft in the repair of bone defects around the implant, PRP may delay peri-implant bone healing.

12.
Maxillofac Plast Reconstr Surg ; 37(1): 40, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26550560

RESUMO

Surgical procedures for parotidectomy had been developed to gain adequate approach, prevent morbidity of nerve, and give esthetic satisfaction. We performed two cases of parotidectomy through facelift incision. One case was reconstructed with superficial musculoaponeurotic system (SMAS) flap and sternocleidomastoid (SCM) muscle rotated flap at the parotid bed. In second case, same procedures were performed, but collagen membrane was additionally implanted for prevention of Frey's syndrome. After surgery, two cases showed esthetic results without neck scar and hollow defect on parotid bed area.

13.
Maxillofac Plast Reconstr Surg ; 37(1): 38, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26523276

RESUMO

BACKGROUND: The posterior movement of mandible was known as the main cause of the changes in the pharyngeal airway space (PAS) and the postoperative obstructive sleep apnea (OSA). The purpose of this study was to know the changes of PAS and position of hyoid bone. METHODS: Lateral cephalographies of 13 patients who had undergone sagittal split ramus osteotomy (SSRO) setback surgery were taken preoperatively (T1), postoperatively within 2 months (T2), and follow-up after 6 months or more (T3). On the basis of F-H plane, diameters of nasopharynx, oropharynx, and hypopharynx were measured. The movements of the soft palate, tongue, and hyoid bone were also measured. RESULTS: The amount of mandible setback was 7.5 ± 3.8 mm. In the measurements of PAS, there was a statistically significant decrease of 2.8 ± 2.5 mm in nasopharynx (P < 0.01), and 1.7 ± 2.4 mm in oropharynx (P < 0.01) were observed after surgery. The hypopharynx decreased 1.0 ± 2.1 mm after surgery and continuously decreased 1.0 ± 2.8 mm at follow-up. The changes in hyoid bone position showed the posterior movement only after surgery and posteroinferior movement at follow-up. CONCLUSIONS: The PAS such as nasopharynx, oropharynx, and hypopharynx showed relatively high correlation with the amount of mandibular setback. The change of resistance in upper airway may be important for the prevention of OSA after mandibular setback surgery.

14.
J Korean Assoc Oral Maxillofac Surg ; 41(3): 139-44, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26131431

RESUMO

Odontogenic carcinosarcoma is an extremely rare malignant odontogenic tumor with only a few reported cases. It is characterized by a true mixed tumor showing malignant cytology of both epithelial and mesenchymal components. It has been assumed to arise from pre-existing lesions such as ameloblastoma, ameloblastic fibroma, and ameloblastic fibrosarcoma. To date, the reported cases have exhibited considerably aggressive clinical behavior. The case of an odontogenic carcinosarcoma in the mandible of a 61-year-old male is described herein. The tumor destroyed the cortex of the mandible and invaded the adjacent tissues. Treatment was performed by surgical resection and reconstruction. The purposes of this article are to introduce odontogenic carcinosarcoma through this case study, to distinguish it from related diseases and to discuss features of the tumor in the existing literature.

15.
J Korean Assoc Oral Maxillofac Surg ; 40(3): 140-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25045642

RESUMO

Pigmented villonodular synovitis (PVNS) is a benign but locally aggressive and destructive disease originating in the synovial membranes. It is a proliferative disorder of unknown etiology. Involvement of the temporomandibular joint (TMJ) is very rare. Computed tomography clearly reveals areas of lytic bone erosion and sclerosis, and also clearly defines the extent of the tumor which is the focal areas of hyperdensity within the soft-tissue mass. Magnetic resonance images invariably show profound hypointensity on both T1- and T2-weighted sequences due to hemosiderin pigmentation. Additionally, high signal intensity on T2-weighted images may indicate cystic loculation of the joint fluid. This case study describes a rare case of PVNS of the TMJ with bone destruction of the mandibular condyle. Complete surgical excision of the lesion was performed through a preauricular approach with temporal extension. During the 10-year follow-up, two more operations were performed due to local recurrence and the fracture of the reconstruction plate. Total joint reconstruction with Biomet was finally performed, and the absence of disease was confirmed with a biopsy report showing fibrosis with hyalinization and mild inflammation of the excised soft tissue from the old lesion.

16.
Ann Occup Environ Med ; 25(1): 23, 2013 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-24472134

RESUMO

OBJECTIVES: The purpose of this study was to identify the risk factors of metabolic syndrome (MS) and to analyze the relationship between the risk factors of MS and medical cost of major diseases related to MS in Korean workers, according to the scale of the enterprise. METHODS: Data was obtained from annual physical examinations, health insurance qualification and premiums, and health insurance benefits of 4,094,217 male and female workers who underwent medical examinations provided by the National Health Insurance Corporation in 2009. Logistic regression analyses were used to the identify risk factors of MS and multiple regression was used to find factors associated with medical expenditures due to major diseases related to MS. RESULT: The study found that low-income workers were more likely to work in small-scale enterprises. The prevalence rate of MS in males and females, respectively, was 17.2% and 9.4% in small-scale enterprises, 15.9% and 8.9% in medium-scale enterprises, and 15.9% and 5.5% in large-scale enterprises. The risks of MS increased with age, lower income status, and smoking in small-scale enterprise workers. The medical costs increased in workers with old age and past smoking history. There was also a gender difference in the pattern of medical expenditures related to MS. CONCLUSIONS: Health promotion programs to manage metabolic syndrome should be developed to focus on workers who smoke, drink, and do little exercise in small scale enterprises.

17.
J Korean Assoc Oral Maxillofac Surg ; 39(6): 257-62, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24516814

RESUMO

OBJECTIVES: Oral and maxillofacial defects often require bone grafts to restore missing tissues. Well-recognized donor sites include the anterior and posterior iliac crest, rib, and intercalvarial diploic bone. The proximal tibia has also been explored as an alternative donor site. The use of the tibia for bone graft has many benefits, such as procedural ease, adequate volume of cancellous and cortical bone, and minimal complications. Although patients rarely complain of pain, swelling, discomfort, or dysfunction, such as gait disturbance, both patients and surgeons should pay close attention to such after effects due to the possibility of tibial fracture. The purpose of this study is to analyze tibial fractures that occurring after osteotomy for a medioproximal tibial graft. MATERIALS AND METHODS: An analysis was intended for patients who underwent medioproximal tibial graft between March 2004 and December 2011 in Inha University Hospital. A total of 105 subjects, 30 females and 75 males, ranged in age from 17 to 78 years. We investigated the age, weight, circumstance, and graft timing in relation to tibial fracture. RESULTS: Tibial fractures occurred in four of 105 patients. There were no significant differences in graft region, shape, or scale between the fractured and non-fractured patients. CONCLUSION: Patients who undergo tibial grafts must be careful of excessive external force after the operation.

18.
J Korean Assoc Oral Maxillofac Surg ; 39(6): 274-82, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24516817

RESUMO

OBJECTIVES: The posterior maxillary region often provides a limited bone volume for dental implants. Maxillary sinus elevation via inserting a bone graft through a window opened in the lateral sinus wall has become the most common surgical procedure for increasing the alveolar bone height in place of dental implants in the posterior maxillary region. The purpose of this article is to assess the change of bone volume and the clinical effects of dental implant placement in sites with maxillary sinus floor elevation and autogenous bone graft through the lateral window approach. MATERIALS AND METHODS: In this article, the analysis data were collected from 64 dental implants that were placed in 24 patients with 29 lacks of the bone volume posterior maxillary region from June 2004 to April 2011, at the Department of Oral and Maxillofacial Surgery, Inha University Hospital. Panoramic views were taken before the surgery, after the surgery, 6 months after the surgery, and at the time of the final follow-up. The influence of the factors on the grafted bone material resorption rate was evaluated according to the patient characteristics (age and gender), graft material, implant installation stage, implant size, implant placement region, local infection, surgical complication, and residual alveolar bone height. RESULTS: The bone graft resorption rate of male patients at the final follow-up was significantly higher than the rate of female patients. The single autogenous bone-grafted site was significantly more resorbed than the autogenous bone combined with the Bio-Oss grafted site. The implant installation stage and residual alveolar height showed a significant correlation with the resorption rate of maxillary sinus bone graft material. The success rate and survival rate of the implant were 92.2% and 100%, respectively. CONCLUSION: Maxillary sinus elevation procedure with autogenous bone graft or autogenous bone in combination with Bio-Oss is a predictable treatment method for implant rehabilitation.

19.
Biochem Biophys Res Commun ; 401(2): 300-5, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20851105

RESUMO

We have identified and characterized a novel transcriptional regulator that binds to the promoter region of succinyl-CoA synthetase (sucCD) in Corynebacterium glutamicum. Using biotin-labeled DNA affinity beads, we identified a DeoR-type transcriptional regulator, SucR (Cg0146), which is a protein consisting of 282 amino acids with a mass of 31 kDa and RamB (Cg0444). The results of electrophoretic mobility shift assays verified that these regulators specifically bind to the sucCD promoter region. The putative SucR binding region extends from position -155 to -146 (a 10 bp sequence, ACTCTAGGGG) relative to the transcriptional start point of the sucCD operon. The expression level of sucCD in a sucR deletion mutant was seven times higher than that in wild-type cells grown on acetate. The increase in succinyl-CoA synthetase levels caused by inactivation of sucR. These assays revealed that SucR acts as a repressor of sucCD expression during acetate metabolism.


Assuntos
Corynebacterium glutamicum/enzimologia , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Proteínas Repressoras/metabolismo , Succinato-CoA Ligases/genética , Acetatos/metabolismo , Sítios de Ligação , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/crescimento & desenvolvimento , Deleção de Genes , Regiões Promotoras Genéticas , Proteínas Repressoras/genética , Transcrição Gênica
20.
J Biochem Mol Biol ; 40(4): 511-6, 2007 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-17669266

RESUMO

A glutathione S-transferase (GST) related to the phi (F) class of enzymes only found in plants has been cloned from the Oryza sativa. The GST cDNA was cloned by PCR using oligonucleotide primers based on the OsGSTF5 (GenBank Accession No. AF309382) sequences. The cDNA was composed of a 669-bp open reading frame encoding for 223 amino acids. The deduced peptide of this gene shared on overall identity of 75% with other known phi class GST sequences. On the other hands, the OsGSTF5 sequence showed only 34% identity with the sequence of the OsGSTF3 cloned by our previous study (Cho et al., 2005). This gene was expressed in Escherichia coli with the pET vector system and the gene product was purified to homogeneity by GSH-Sepharose affinity column chromatography. The expressed OsGSTF5 formed a homo-dimer composed of 28 kDa subunit and its pI value was approximately 7.8. The expressed OsGSTF5 displayed glutathione conjugation activity toward 1-chloro-2,4-dinitrobenzene and 1,2-epoxy-3-(p-nitrophenoxy)propane and glutathione peroxidase activity toward cumene hydroperoxide. The OsGSTF5 also had high activities towards the herbicides alachlor, atrazine and metolachlor. The OsGSTF5 was highly sensitive to inhibition by ShexylGSH, benastatin A and hematin. We propose from these results that the expressed OsGSTF5 is a phi class GST and appears to play a role in the conjugation of herbicide and GPOX activity.


Assuntos
Glutationa Transferase/química , Glutationa Transferase/genética , Oryza/enzimologia , Sequência de Aminoácidos , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Inibidores Enzimáticos/farmacologia , Vetores Genéticos , Glutationa Transferase/isolamento & purificação , Cinética , Dados de Sequência Molecular , Peso Molecular , Filogenia , Homologia de Sequência de Aminoácidos , Especificidade por Substrato/efeitos dos fármacos
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