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1.
Comput Methods Programs Biomed ; 175: 215-222, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31104709

RESUMO

BACKGROUND AND OBJECTIVE: Computed tomography (CT) is one of the most frequently used medical imaging methods. An important application area of CT is dental implants, which require precise inspection and analysis of oral structures. Since CT provides a precise 3D model of the teeth, bones and nerves, it can be used as a surgical guide for dental implants. Along with CT, optical 3D images called stereolithography (STL) have also been widely used. STL images obtained from optical 3D images can be used to show the 3D surfaces of oral structures. Since CT data and STL data deploy different technologies to obtain dental information, we can obtain more accurate dental implants by combining the two datasets. Since the two datasets are acquired by using different sensors, the datasets need to be registered. METHODS: An automatic matching algorithm is proposed for CT and STL image registration, which is based on depth maps and maximum intensity projection. Then, fine tuning was performed based on volume matching. RESULTS: When applied to real-world databases, the proposed method provided an average matching error of 2.7 mm for the upper jaw and 2.3 mm for the lower jaw with an average processing time of about 19 s. CONCLUSIONS: The proposed method performs accurate registration of CT and STL.


Assuntos
Estereolitografia , Tomografia Computadorizada por Raios X , Algoritmos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/métodos , Modelos Anatômicos , Reconhecimento Automatizado de Padrão , Reprodutibilidade dos Testes , Dente/diagnóstico por imagem , Raios X
2.
Br J Oral Maxillofac Surg ; 52(1): 54-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24029441

RESUMO

Our aim was to investigate the correlation among antibiotic prophylaxis, difficulty of extraction, and postoperative complications in the removal of lower 3rd molars. A total of 1222 such extractions in 890 patients between January 2010 and January 2012 were analysed retrospectively. The difficulty of extraction measured by Pederson's index, antibiotic prophylaxis with cefditoren, and postoperative complications were recorded. The difficulty of extraction was significantly associated with postoperative complications (p=0.03). There were no significant associations between antibiotic prophylaxis and postoperative complications in groups of equal difficulty ("easy" group (class I) p=1.00; "moderate" group (class II) p=1.00; and "difficult" group (class III) p=0.65). There was a small but insignificant increase in the number of dry sockets and infections in class III cases. In conclusion, this study provides further evidence that antibiotic prophylaxis for the prevention of postoperative inflammatory complications is unnecessary for extraction of 3rd molars.


Assuntos
Antibioticoprofilaxia , Mandíbula/cirurgia , Dente Serotino/cirurgia , Complicações Pós-Operatórias , Extração Dentária/métodos , Adolescente , Adulto , Idoso , Anestesia Dentária/métodos , Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Alvéolo Seco/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Bloqueio Nervoso/métodos , Osteotomia/métodos , Dor Pós-Operatória/etiologia , Estudos Retrospectivos , Retalhos Cirúrgicos/cirurgia , Infecção da Ferida Cirúrgica/etiologia , Extração Dentária/classificação , Trismo/etiologia , Adulto Jovem
3.
Actas Urol Esp ; 36(3): 165-70, 2012 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-22018947

RESUMO

OBJECTIVES: To evaluate relationship between intravesical prostatic protrusion (IPP) on transrectal ultrasonography (TRUS) and pressure-flow study (PFS) findings in patients with benign prostatic obstruction/lower urinary tract symptoms (BPO/LUTS). MATERIAL AND METHODS: Between March 2006 and August 2009, we reviewed medical records of 87 patients who were underwent TRUS and PFS for evaluation of their LUTS. The patients were classified by the IPP vertical degree: less than 5 mm (group A), 5-10 mm (group B), over than 10 mm (groupC). The extent of bladder outlet obstruction was calculated as the bladder outlet obstruction index (BOOI) by the PFS. The obstruction was defined as the BOOI over 40. RESULTS: Mean age was 71.1 years, and mean IPP vertical was 8.23 mm. The IPP vertical showed significant correlation with prostate volume (r=0.688, P<0.001) and transitional zone volume (TZV) (r=0.645, P<0.001), but there was no correlation between IPP and International Prostate Symptom Score, maximal flow rate, post-voided residual urine and BOOI. The IPP transverse was significantly correlated with BOOI (r=0.213, P=0.048). CONCLUSIONS: The IPP vertical showed significant correlation with prostate volume and transitional volume, but not with severity of symptom, quality of life, parameters of PFS. However, the IPP transverse on TRUS was correlated with BOOI.


Assuntos
Próstata/patologia , Hiperplasia Prostática/patologia , Obstrução do Colo da Bexiga Urinária/etiologia , Bexiga Urinária/patologia , Urodinâmica , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Complicações Pós-Operatórias/etiologia , Próstata/diagnóstico por imagem , Hiperplasia Prostática/complicações , Hiperplasia Prostática/diagnóstico por imagem , Hiperplasia Prostática/fisiopatologia , Qualidade de Vida , Estudos Retrospectivos , Índice de Gravidade de Doença , Ressecção Transuretral da Próstata , Ultrassonografia , Bexiga Urinária/diagnóstico por imagem , Obstrução do Colo da Bexiga Urinária/diagnóstico por imagem , Obstrução do Colo da Bexiga Urinária/patologia , Obstrução do Colo da Bexiga Urinária/fisiopatologia , Obstrução do Colo da Bexiga Urinária/cirurgia , Retenção Urinária/etiologia
4.
Phys Rev Lett ; 106(5): 057801, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21405437

RESUMO

Circular domains in phase-separated lipid vesicles with symmetric leaflet composition commonly exhibit three stable morphologies: flat, dimpled, and budded. However, stable dimples (i.e., partially budded domains) present a puzzle since simple elastic theories of domain shape predict that only flat and spherical budded domains are mechanically stable in the absence of spontaneous curvature. We argue that this inconsistency arises from the failure of the constant surface tension ensemble to properly account for the effect of entropic bending fluctuations. Formulating membrane elasticity within an entropic tension ensemble, wherein tension represents the free energy cost of extracting membrane area from thermal bending of the membrane, we calculate a morphological phase diagram that contains regions of mechanical stability for each of the flat, dimpled, and budded domain morphologies.


Assuntos
Membrana Celular/química , Entropia , Lipídeos de Membrana/química , Temperatura de Transição
5.
Pharmacogenomics J ; 11(3): 191-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20351753

RESUMO

SLC30A8 encodes the ß-cell-specific zinc transporter-8 (ZnT-8) expressed in insulin secretory granules. The single-nucleotide polymorphism rs13266634 of SLC30A8 is associated with susceptibility to post-transplantation diabetes mellitus (PTDM). We tested the hypothesis that the polymorphic residue at position 325 of ZnT-8 determines the susceptibility to cyclosporin A (CsA) suppression of insulin secretion. INS (insulinoma)-1E cells expressing the W325 variant showed enhanced glucose-stimulated insulin secretion (GSIS) and were less sensitive to CsA suppression of GSIS. A reduced number of insulin granule fusion events accompanied the decrease in insulin secretion in CsA-treated cells expressing ZnT-8 R325; however, ZnT-8 W325-expressing cells exhibited resistance to the dampening of insulin granule fusion by CsA, and transported zinc ions into secretory vesicles more efficiently. Both tacrolimus and rapamycin caused similar suppression of GSIS in cells expressing ZnT-8 R325. However, cells expressing ZnT-8 W325 were resistant to tacrolimus, but not to rapamycin. The Down's syndrome candidate region-1 (DSCR1), an endogenous calcineurin inhibitor, overexpression and subsequent calcineurin inhibition significantly reduced GSIS in cells expressing the R325 but not the W325 variant, suggesting that differing susceptibility to CsA may be due to different interactions with calcineurin. These data suggest that the ZnT-8 W325 variant is protective against CsA-induced suppression of insulin secretion. Tolerance of ZnT-8 W325 to calcineurin activity may account for its protective effect in PTDM.


Assuntos
Proteínas de Transporte de Cátions/genética , Ciclosporina/efeitos adversos , Diabetes Mellitus/etiologia , Diabetes Mellitus/genética , Insulina/metabolismo , Transplante de Rim/efeitos adversos , Alelos , Animais , Biomarcadores Farmacológicos , Inibidores de Calcineurina , Linhagem Celular , Ciclosporina/uso terapêutico , Proteínas de Ligação a DNA , Glucose/metabolismo , Humanos , Imunossupressores/efeitos adversos , Secreção de Insulina , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Mutação , Ratos , Transportador 8 de Zinco
6.
Transpl Infect Dis ; 12(1): 31-7, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19843292

RESUMO

BACKGROUND: We performed a retrospective historical cohort study to compare the efficacy of higher dose (HD, 10 mg/kg/day for 2 weeks, followed by 5 mg/kg/day intravenously for 2 weeks) and lower dose (LD, 5 mg/kg/day for 4 weeks) ganciclovir (GCV) for cytomegalovirus (CMV) prophylaxis in seropositive heart transplant recipients. METHODS: All consecutive patients undergoing heart transplantation (HT) between June 1999 and January 2008 at our institution were enrolled. All recipients were seropositive for CMV before HT. Before October 2005, 72 patients received the HD regimen and after October 2005, 36 patients received the LD regimen. We followed up all patients for 1 year. RESULTS: In the HD group 43 of 72 patients (60%) developed CMV infections vs. 21 of 36 patients (58%) in the LD group (P=0.89). CMV diseases occurred in 4 patients of the HD group (6%) and 4 patients of the LD group (11%) (P=0.44). The incidence of acute rejection was not significantly different between the 2 groups (14% vs. 6%; P=0.33). Among patients who completed 4-week courses of prophylaxis, 32 of 58 patients (55%) in the HD group developed CMV infections vs. 18 of 30 patients (60%) in the LD group (P=0.66). CMV diseases occurred in 3 patients of the HD group (5%) and 4 of the LD group (13%) (P=0.22). Acute rejection incidence did not differ significantly between the 2 groups (17% vs. 7%; P=0.21). CONCLUSIONS: LD GCV for CMV prophylaxis may not be inferior to the HD regimen in seropositive HT recipients.


Assuntos
Antivirais/administração & dosagem , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/prevenção & controle , Ganciclovir/administração & dosagem , Transplante de Coração/efeitos adversos , Adulto , Quimioprevenção , Estudos de Coortes , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/fisiopatologia , Infecções por Citomegalovirus/virologia , Esquema de Medicação , Feminino , Rejeição de Enxerto/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
7.
Clin Exp Dermatol ; 30(4): 409-13, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15953083

RESUMO

Transepidermal water loss (TEWL) in psoriatic skin lesions seems to be related to the severity of the psoriasis, and the electrical capacitance and conductance of the skin are indicators of the hydration level of the stratum corneum. We compared the characteristics of these electrical measurements, in assessing the persistent effect of a moisturizing cream on skin hydration and barrier function in psoriasis patients. Seventeen Korean psoriasis patients were recruited. Their right leg was treated with the moisturizer twice daily for 6 weeks, while their left leg was used as the control site. For each patient, one psoriatic plaque on each leg was selected as the involved psoriatic lesion. Uninvolved psoriatic skin was regarded as the apparently healthy looking skin 4-5 cm away from the periphery of the psoriatic lesion. The TEWL, electrical capacitance and conductance were measured, in order to evaluate the barrier function and hydration level of the stratum corneum. The clinical and biophysical data for each patient were recorded at the start of the study and after 2, 4 and 6 weeks. The degree of skin dryness at the applied area improved progressively. The electrical capacitance at the treated psoriatic lesion increased significantly after 2 weeks, and this improvement was maintained during the entire study period. However, no noticeable change was observed in the electrical conductance. The TEWL showed an inverse pattern to that of the skin capacitance, decreasing during the study period. The skin capacitance and TEWL exhibited good correlation with the visual assessment of skin dryness, but the skin conductance did not. Our data suggest that electrical capacitance and TEWL may be useful in the evaluation of the effect of a moisturizer on the hydration status and barrier function of psoriatic skin.


Assuntos
Emolientes/farmacologia , Resposta Galvânica da Pele/efeitos dos fármacos , Psoríase/tratamento farmacológico , Perda Insensível de Água/efeitos dos fármacos , Adulto , Água Corporal/metabolismo , Emolientes/uso terapêutico , Feminino , Humanos , Dermatoses da Perna/tratamento farmacológico , Dermatoses da Perna/fisiopatologia , Masculino , Pessoa de Meia-Idade , Pomadas , Psoríase/fisiopatologia , Resultado do Tratamento
8.
Water Sci Technol ; 49(5-6): 199-205, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15137424

RESUMO

This research aimed to effectively remove high-concentration organic matter and nutrients from slurry-type swine waste using a combined upflow anaerobic sludge blanket reactor with the dissolved air flotation/aerobic submerged biofilm/anoxic/aerobic process. The upflow anaerobic sludge blanket reactor was operated at an organics volumetric loading rate of 3.2-6.1 kg COD/m3/day, and the removal rates of COD were 53.9-65.5%. The removal rate of COD of the overall process was more than 99%. In the aerobic submerged biofilm, over 95% of ammonium nitrogen was removed at a volumetric loading rate of 0.08-0.16 kg NH4+-N/m3/day. The specific denitrification rate was 0.257 g NO3-N/g MLVSS/day and the removal rate of total nitrogen was 86.7%. Phosphorus was removed by flocculation in the dissolved air flotation process, and 0.16 g of PO4-P was removed by 1 g of ferric ion.


Assuntos
Reatores Biológicos , Nitrogênio/isolamento & purificação , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Animais , Bactérias Aeróbias/fisiologia , Bactérias Anaeróbias/fisiologia , Biofilmes , Esterco , Solubilidade , Suínos
9.
Water Sci Technol ; 49(5-6): 215-22, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15137426

RESUMO

Precipitation of ammonium together with phosphate and magnesium is a possible alternative for lowering the nitrogen content of wastewater. In this study we examine the removal of ammonium nitrogen and phosphorus from slurry-type swine wastewater containing high concentrations of nutrients by the addition of phosphoric acid along with either calcium oxide or magnesium oxide, which leads to the crystallization of insoluble salts such as hydroxyapatite and struvite. The struvite crystallization method showed a high capacity for the removal of nitrogen when magnesium oxide and phosphoric acid were used as the magnesium and phosphate sources, respectively. When it was applied to swine wastewater containing a high concentration of nitrogen, the injection molar ratio of Mg2+:NH4+:PO4(3-) that gave maximum ammonium nitrogen removal was 3.0:1.0:1.5.


Assuntos
Compostos de Magnésio/química , Nitrogênio/isolamento & purificação , Nitrogênio/metabolismo , Fosfatos/química , Eliminação de Resíduos Líquidos/métodos , Poluentes da Água/metabolismo , Animais , Bactérias Anaeróbias , Precipitação Química , Cristalização , Magnésio/química , Esterco , Compostos de Amônio Quaternário/química , Estruvita , Suínos , Poluentes da Água/isolamento & purificação
10.
Photodermatol Photoimmunol Photomed ; 18(3): 127-30, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12207675

RESUMO

BACKGROUND/PURPOSE: Narrow-band (TL-01) UVB lamps are being increasingly used for phototherapy of psoriasis and other dermatoses, for their excellent effect compared with broad-band UVB sources. Many patients receiving phototherapy have complained about the tanning effect of ultraviolet radiation especially in dark-skinned ones. So we wished to know the degree of pigmentation induced by phototherapy during narrow-band UVB treatment. METHODS: A total of 20 psoriasis patients receiving narrow-band UVB phototherapy were included in this study. A Minolta spectrophotometer CM-2002 was used to measure pigmentation. All patients were evaluated for skin color every seventh day for 7 weeks. The L* value (luminance) gives information about the relative lightness ranging from total black to pure white. The a* value represents the balance between red and green, and the b* value between yellow and blue. RESULTS: The L* values which indicate luminance decreased continuously until the 5th week, when maximum tanning was obtained. Afterwards minimal change was observed until the 7th week. The change of a* and b* values also showed the pattern that was compatible with the above results. The mean individual typology angle of our subjects was 41.9 degrees, which indicated they fell into "light" group of constitutional skin color category. CONCLUSION: From this study, we found that pigmentation induced by narrow-band UVB phototherapy increased continuously until the 5th week and then did not progress. Our results provide standard data of skin pigmentation during narrow-band UVB phototherapy in Korean brown skin.


Assuntos
Fototerapia/métodos , Pigmentação da Pele/efeitos da radiação , Raios Ultravioleta , Adulto , Colorimetria , Relação Dose-Resposta à Radiação , Feminino , Humanos , Coreia (Geográfico) , Masculino , Pessoa de Meia-Idade , Psoríase/terapia , Raios Ultravioleta/efeitos adversos , Raios Ultravioleta/classificação
11.
Clin Exp Dermatol ; 26(3): 242-7, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11422165

RESUMO

We describe two Korean adult patients who had necrotizing papulovesicles mainly on their faces. Skin biopsy specimens showed perivascular and periadnexal infiltrate of atypical lymphoid cells with vasculitis in the dermis and subcutaneous tissue. In situ hybridization demonstrated a latent infection of Epstein-Barr virus in the majority of lymphoid cells in the dermis. These patients were diagnosed as having T-cell lymphoma. Interestingly, large granular lymphocytosis was found in the peripheral blood of Case 2.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Dermatoses Faciais/virologia , Hidroa Vaciniforme/virologia , Linfoma de Células T Periférico/virologia , Dermatopatias Virais/virologia , Adulto , Feminino , Rearranjo Gênico da Cadeia gama dos Receptores de Antígenos dos Linfócitos T , Humanos , Masculino
12.
Talanta ; 55(2): 297-304, 2001 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-18968373

RESUMO

Five novel 1,3-alternate calix[4]azacrown ethers having 2-picolyl, 3-picolyl, and benzyl unit on the nitrogen atom were synthesized and used as ionophores for transition metal-selective polymeric membrane electrodes. The electrode based on 2-picolyl armed 1,3-alternate calix [4] azacrown ether exhibited Nernstian response toward copper (II) ion over a concentration range (10(-4.5) M-10(-2.5) M). The detection limit was determined as 10(-5) M in pH 7 and the selectivity coefficients for possible interfering cations were evaluated. Anions in the sample solution strongly affected the electrode response.

13.
Acta Crystallogr C ; 56 Pt 11: 1369-71, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11077302

RESUMO

A new calix[4]-crowned azacrown ether, C(51)H(59)NO(11)S, consisting of four phenyl rings in a 1,3-alternate conformation was synthesized from the reaction of 25, 27-bis(5-chloro-3-oxapentyloxy)calix[4]crown-5 and p-toluenesulfonamide in the presence of Cs(2)CO(3). A crown-5 loop was attached on the two facing lower rims of the calix[4]arene and the N-tosyl azacrown group was attached on the other set of lower rims of the calix[4]arene backbone. This molecule seems to offer an inside cavity for the formation of a host-guest complex.

14.
J Med Eng Technol ; 24(3): 87-94, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11036574

RESUMO

The purpose of our study is to compare haemodynamic responses and the ischaemic potential of commonly used inotropes (dopamine, dobutamine and milrinone) using a computer model of the cardiovascular system. Cardiotropic drugs interact with the model by changing ventricular elastance and resistance of the individual circulation. All three drugs increase cardiac index in a dose-dependent manner. Dopamine at medium and high infusion rates increases heart rate, systemic vascular resistance and arterial blood pressure. The associated increase in coronary blood flow, however, is not sufficient to account for increased oxygen demand. Both dobutamine and milrinone decrease vascular resistance and increase coronary blood flow. The more pronounced increase in heart rate associated with dobutamine, however, results in a higher ischaemic potential for this drug. Our simulation demonstrates that although all the drugs studied improve cardiac function in simulated patients with heart failure, milrinone accomplishes this at a lower energy cost. The computer simulation developed can be used to assess the complex effect of cardiotropic drugs and possibly suggest optimal drug therapy in specific clinical situations.


Assuntos
Cardiotônicos/farmacologia , Simulação por Computador , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Miocárdio/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Dobutamina/farmacologia , Relação Dose-Resposta a Droga , Humanos , Milrinona/farmacologia
15.
Gen Pharmacol ; 35(4): 205-11, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11827727

RESUMO

In the present study, we observed that pentoxifylline (PTX) significantly augmented the nitric oxide (NO) production and the iNOS gene expression by interleukin-1beta (IL-1beta)-stimulated vascular smooth muscle cells (VSMCs). The enhancing effects of PTX on the IL-1beta-induced NO production was associated with an increased intracellular cyclic AMP (cAMP) levels, and the synergistic effects of PTX on the IL-1beta-induced NO production was blocked by cAMP-dependent protein kinase A (PKA) inhibitors. PKA inhibitors, KT5720 and H89, markedly decreased the augmented expression of iNOS gene whereas ODQ, a soluble guanylate cyclase inhibitor, did not affect the enhancing effect. In addition, the pretreatment with KT5720 or H89 abolished the increased translocation of the p65 subunit of NF-kappaB into the nucleus by PTX in the IL-1beta-stimulated VSMCs. These results suggest that enhancing effects of PTX on the iNOS gene expression in the IL-1beta-stimulated VSMCs is mediated predominantly through the activation of NF-kappaB via cAMP-dependent PKA pathway.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , AMP Cíclico/fisiologia , Interleucina-1/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Óxido Nítrico/biossíntese , Pentoxifilina/farmacologia , Vasodilatadores/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Cultivadas , AMP Cíclico/análise , Proteína Quinase Tipo II Dependente de AMP Cíclico , Citoplasma/metabolismo , Sinergismo Farmacológico , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase Tipo II , Ratos , Fator de Transcrição RelA
16.
Biochim Biophys Acta ; 1446(3): 359-64, 1999 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-10524210

RESUMO

When certain cells are exposed to a hypertonic solution, transcription of the BGT1 gene is markedly increased. The ensuing rise in betaine transport leads to cellular accumulation of betaine that protects the cells from the stress of hypertonicity. We have previously identified a tonicity-responsive enhancer (TonE1) in the 5' flanking region of the BGT1 gene. It was recognized, however, that full activation of transcription requires additional sequence upstream from the TonE1. Now we report that there is another TonE (named TonE2) 72 base pairs upstream from the TonE1. TonE1 and TonE2 act synergistically to stimulate transcription of BGT1 in response to hypertonicity.


Assuntos
Proteínas de Transporte/genética , Elementos Facilitadores Genéticos , Soluções Hipertônicas/farmacologia , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Cães , Proteínas da Membrana Plasmática de Transporte de GABA , Rim/metabolismo , Luciferases/genética , Dados de Sequência Molecular , Mutação , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Elementos de Resposta , Transativadores/metabolismo , Transcrição Gênica/efeitos dos fármacos , Transfecção
17.
J Biol Chem ; 273(32): 20615-21, 1998 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-9685419

RESUMO

The sodium/myo-inositol cotransporter is a plasma membrane protein responsible for concentrative cellular accumulation of myo-inositol in a variety of tissues. When cells in kidney and brain are exposed to a hyperosmolar salt condition (hypertonicity) due to the operation of urinary concentration mechanism and pathological conditions, respectively, they survive the stress of hypertonicity by raising the cellular concentration of myo-inositol. Transcription of the sodium/myo-inositol cotransporter gene is markedly stimulated in response to hypertonicity, leading to an increase in the activity of the cotransporter, which in turn drives the osmoprotective accumulation of myo-inositol. To understand the molecular mechanisms by which hypertonicity stimulates transcription, we analyzed the 5'-flanking region of the cotransporter gene for cis-acting regulatory sequences. We identified five tonicity-responsive enhancers that are scattered over 50 kilobase pairs. All the enhancers are variations of the same type of enhancer interacting with the transcription factor named tonicity-responsive enhancer binding protein. In vivo methylation experiments demonstrated that exposure of cells to hypertonicity increases the binding of tonicity-responsive enhancer binding protein to the enhancer sites, indicating that all of these enhancers are involved in the transcriptional stimulation. We conclude that the sodium/myo-inositol cotransporter gene is regulated by a large region (approximately 50 kilobase pairs) upstream of the gene.


Assuntos
Proteínas de Transporte/genética , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica/genética , Proteínas de Choque Térmico/genética , Proteínas de Membrana , Simportadores , Transcrição Gênica/genética , Animais , Sequência de Bases , Transporte Biológico/genética , Linhagem Celular , Membrana Celular/química , Clonagem Molecular , Proteínas de Ligação a DNA/fisiologia , Genes Reporter , Soluções Hipertônicas/farmacologia , Inositol/metabolismo , Dados de Sequência Molecular , Concentração Osmolar , Fatores de Transcrição/metabolismo , Transfecção/genética
18.
Biochemistry ; 36(23): 7064-70, 1997 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-9188705

RESUMO

Trans-phosphorylation of rhodopsin refers to a reaction in which a rhodopsin kinase molecule that has been activated by a light-activated rhodopsin molecule collides with and phosphorylates a second molecule of rhodopsin that has not been activated by light. It has been invoked as a mechanism for high-gain phosphorylation, a phenomenon that is observed at low bleaching levels where up to several hundred moles of phosphate are added to the rhodopsin pool per mole of photolyzed rhodopsin. Trans-phosphorylation is an appealing mechanism to propose for high-gain phosphorylation, but it has not been tested directly because of the difficulty inherent in unambiguous identification of light-activated and dark forms of rhodopsin present in the same reaction mixture. We report here a direct assay for trans-phosphorylation of rhodopsin. The assay is based on the use of a split receptor mutant of rhodopsin, SR(1-4/5-7), in which the fully functional protein is assembled from two separately expressed fragments. Because of different electrophoretic mobilities, SR(1-4/5-7) and wild-type rhodopsin can be monitored independently for phosphorylation while in the same reaction mixture. Thus, if wild-type rhodopsin is exposed to light and then incubated in the dark with SR(1-4/5-7), ATP, and rhodopsin kinase, phosphorylation of SR(1-4/5-7) would be a clear demonstration that trans-phosphorylation has occurred. Despite numerous attempts using several different experimental configurations, we have been unable to detect trans-phosphorylation of dark rhodopsin with this system.


Assuntos
Proteínas do Olho/metabolismo , Proteínas Quinases/metabolismo , Rodopsina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Células COS , Receptor Quinase 1 Acoplada a Proteína G , Técnicas In Vitro , Luz , Fosforilação
20.
Arch Biochem Biophys ; 341(1): 193-9, 1997 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9143369

RESUMO

The sodium/myo-inositol cotransporter (SMIT) is a plasma membrane protein catalyzing transfer of myo-inositol into cells against a considerable concentration gradient using the electrochemical potential of sodium across the cell membrane. Transcription of the SMIT gene is markedly stimulated when cells are exposed to a hypertonic environment resulting in increased abundance of SMIT mRNA and increased SMIT activity. The increased accumulation of myo-inositol protects cells from the deleterious effects of hypertonicity. In an effort toward understanding transcriptional regulation, we cloned canine genomic DNA fragments containing the SMIT gene. The gene is 37 kb in size consisting of 2 exons and a large intron of 25 kb. The entire open reading frame is in the second exon. The promoter of the gene is highly active due to a GC-rich sequence. Ribonuclease protection assay using a riboprobe complementary to the 5' end of the gene confirmed that the promoter of the gene is stimulated by hypertonicity. The promoters and regulatory sequences of the SMIT gene and the betaine transporter gene, another gene regulated by hypertonicity, appear to be different.


Assuntos
Proteínas de Transporte/genética , Proteínas de Choque Térmico/genética , Regiões Promotoras Genéticas , Simportadores , Animais , Sequência de Bases , Northern Blotting , Cloranfenicol O-Acetiltransferase/genética , Cloranfenicol O-Acetiltransferase/metabolismo , Mapeamento Cromossômico , Clonagem Molecular , Cães , Éxons/genética , Biblioteca Gênica , Genes Reporter , Inositol/metabolismo , Íntrons/genética , Luciferases/genética , Luciferases/metabolismo , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Sequências Reguladoras de Ácido Nucleico , Transcrição Gênica/genética
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