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3.
ESMO Open ; 9(4): 102942, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38503143

RESUMO

BACKGROUND: Optimizing immune checkpoint inhibitor (ICI) therapy may require identification of co-targetable checkpoint pathways via immune profiling. Herein, we analyzed the transcriptomic expression and clinical correlates of V-domain immunoglobulin suppressor of T-cell activation (VISTA), a promising targetable checkpoint. PATIENTS AND METHODS: RNA sequencing was carried out on 514 tissues reflecting diverse advanced/metastatic cancers. Expression of eight immune checkpoint markers [lymphocyte-activation gene 3 (LAG-3), tumor necrosis factor receptor superfamily 14 (TNFRSF14), programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), programmed death-ligand 2 (PD-L2), B- and T-lymphocyte attenuator (BTLA), T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), cytotoxic T-lymphocyte antigen 4 (CTLA-4)], in addition to VISTA, was analyzed, along with clinical outcomes. RESULTS: High VISTA RNA expression was observed in 32% of tumors (66/514) and was the most common highly expressed checkpoint among the nine assessed. High VISTA expression was independently correlated with high BTLA, TIM-3, and TNFRSF14, and with a diagnosis of pancreatic, small intestine, and stomach cancer. VISTA transcript levels did not correlate with overall survival (OS) from metastatic/advanced disease in the pan-cancer cohort or with immunotherapy outcome (progression-free survival and OS from the start of ICI) in 217 ICI-treated patients. However, in ICI-treated pancreatic cancer patients (n = 16), median OS was significantly shorter (from immunotherapy initiation) for the high- versus not-high-VISTA groups (0.28 versus 1.21 years) (P = 0.047); in contrast, VISTA levels were not correlated with OS in 36 pancreatic cancer patients who did not receive ICI. CONCLUSION: High VISTA expression correlates with high BTLA, TIM-3, and TNFRSF14 checkpoint-related molecules and with poorer post-immunotherapy survival in pancreatic cancer, consistent with prior literature indicating that VISTA is prominently expressed on CD68+ macrophages in pancreatic cancers and requiring validation in larger prospective studies. Immunomic analysis may be important for individualized precision immunotherapy.


Assuntos
Antígenos B7 , Neoplasias , Humanos , Neoplasias/imunologia , Antígenos B7/metabolismo , Masculino , Feminino , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Pessoa de Meia-Idade , Biomarcadores Tumorais/metabolismo , Proteínas de Checkpoint Imunológico/metabolismo , Idoso
4.
Int J Oral Maxillofac Surg ; 51(7): 942-948, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34937677

RESUMO

The aim of this study was to clarify the clinical significance of bone metabolism in the mandibular condyles in determining condylar resorptive changes. Twelve condyles of patients with idiopathic condylar resorption and degenerative joint disease were analysed using 99mTc HMDP SPECT/CT at baseline and subsequent computed tomography during the follow-up period. Twenty-two healthy condyles were enrolled as controls. After generating three-dimensional SPECT/CT images, two independent observers scored the degree of condylar uptake and measured the morphological changes in the condylar height and condylar volume. In the group with positive condylar uptake, the follow-up computed tomography showed significant decreases in condylar height (-1.69 ± 0.93 mm) and condylar volume (-12.51 ± 10.30%) when compared to healthy controls (condylar height, 0.09 ± 0.54 mm; condylar volume, -0.29 ± 4.22%) (P < 0.001). Moreover, the degree of uptake correlated with the changes in condylar height (observer 1, P = 0.012; observer 2, P = 0.039) and condylar volume (observer 1, P = 0.005; observer 2, P = 0.037). These results suggest that condylar bone metabolism is closely related to the resorptive activity. Thus, SPECT/CT would be useful in the prognostic evaluation or determination of treatment strategies for idiopathic condylar resorption and degenerative joint disease.


Assuntos
Artropatias , Côndilo Mandibular , Humanos , Imageamento Tridimensional/métodos , Côndilo Mandibular/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X
5.
Bioorg Med Chem Lett ; 21(6): 1786-91, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21324693

RESUMO

The anti-hypertensive effect of Eucommia leaves has been confirmed clinically, and the study of their anti-obesity properties has advanced. However, the compounds involved in their anti-obesity effect have not been fully elucidated. In this Letter, we examined the anti-obesity effect of Eucommia green leaf extract (EGLE) divided into five fractions with high porous polystyrene gel and of the compounds isolated, geniposidic acid, asperuloside and chlorogenic acid, respectively. A metabolic syndrome-like clinical model in mice was generated by feeding a 40% high-fat diet to examine the anti-obesity effects of chronic administration of test substance. After 4 weeks, body weight, white adipose tissue weight, plasma triglyceride levels and total cholesterol levels in the model mice were significantly inhibited by the 30% MeOH fraction (containing much higher levels of asperuloside than the other fractions), and these effects were similar to those of EGLE. Chronic administration of isolated asperuloside in Eucommia leaves suppressed increases in model mouse body weight, white adipose tissue weight, plasma triglyceride levels and free fatty acids levels. These results suggest that asperuloside in Eucommia leaves has important anti-obesity effects.


Assuntos
Fármacos Antiobesidade/isolamento & purificação , Eucommiaceae/química , Folhas de Planta/química , Tecido Adiposo/efeitos dos fármacos , Animais , Fármacos Antiobesidade/farmacologia , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Triglicerídeos/sangue
7.
J Dent Res ; 97(7): 779-786, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29494307

RESUMO

This study investigated a case of spindle cell carcinoma (SpCC) in tongue pathological lesions. The patient experienced a local recurrence and distant metastasis after surgical intervention. Although standard chemotherapy was administered, a granulomatous mass continued to develop. This aggressive growth led to survival of the tumor. Secondary debulking surgery was performed to improve the patient's quality of life at the request of the patient. Using a tissue sample derived from the secondary debulking surgery, we performed an analysis of the tumor's cell surface antigens, differentiation potential, metastatic ability, and inhibition potential by anticancer reagents. In vitro analysis revealed that the cell population grown under adherent culture conditions expressed the mesenchymal stem cell (MSC) markers CD73, CD90, and CD105. The cell line established from this SpCC contained colony-forming unit fibroblasts (CFU-Fs) and exhibited multipotent differentiation into several mesenchymal lineages, including bone, cartilage, and fat. The SpCC cells also displayed vigorous mobilization. These characteristics suggested that they had the differentiation potential of mesenchymal cells, especially MSCs, rather than that of epithelial cells. The surgical specimen analyzed in this study resisted the molecular target reagent cetuximab, which is an epidermal growth factor receptor inhibitor. This clinical insight revealed that chemotherapy-resistant SpCC cells have different characteristics compared to most other cancer cells, which are sensitive to cetuximab. Our cell death assay revealed that SpCC cell death was induced by the anticancer drug imatinib, which is known to inhibit protein tyrosine kinase activity of ABL, platelet-derived growth factor receptor α (PDGFRα), and KIT. Here, we report recurrent SpCC with characteristics of MSCs and potential for treatment with imatinib.


Assuntos
Carcinoma/patologia , Células-Tronco Mesenquimais/patologia , Recidiva Local de Neoplasia/patologia , Neoplasias da Língua/patologia , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/análise , Carcinoma/terapia , Técnicas de Cultura de Células , Morte Celular , Diferenciação Celular , Movimento Celular , Terapia Combinada , Resistencia a Medicamentos Antineoplásicos , Citometria de Fluxo , Humanos , Recidiva Local de Neoplasia/terapia , Procedimentos Cirúrgicos Bucais , Qualidade de Vida , Células-Tronco , Neoplasias da Língua/terapia , Células Tumorais Cultivadas
8.
Cochrane Database Syst Rev ; (2): CD004484, 2007 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-17443547

RESUMO

BACKGROUND: There is a range of treatment options for the management of the pulp in extensively decayed teeth. These include direct and indirect pulp capping, pulpotomy or pulpectomy. If the tooth is symptomatic or if there are periapical bone changes, then endodontic treatment is required. However, if the tooth is asymptomatic but the caries is extensive, there is no consensus as to the best method of management. In addition, there has been a recent move towards using alternative materials and methods such as the direct or indirect placement of bonding agents and mineral trioxide aggregate. Most studies have investigated the management of asymptomatic carious teeth with or without an exposed dental pulp using various capping materials (e.g. calcium hydroxide, Ledermix, Triodent, Biorex, etc.). However, there is no long term data regarding the outcome of management of asymptomatic, carious teeth according to different regimens. OBJECTIVES: This study aims to assess the effectiveness of techniques used to treat asymptomatic carious teeth and maintain pulp vitality. SEARCH STRATEGY: Electronic searches of the following databases were undertaken: The Cochrane Oral Health Group's Trials Register (March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to week 4, February 2006), EMBASE (1974 to 13 March 2006), National Research Register (March 2006), Science Citation Index - SCISEARCH (1981 to March 2006). Detailed search strategies were developed for each database. Handsearching and screening of reference lists were undertaken. There was no restriction with regard to language of publication. SELECTION CRITERIA: Studies included were randomised controlled trials (RCTs). Asymptomatic vital permanent teeth with extensive caries were included. Studies were those which compared techniques to maintain pulp vitality. Outcome measures included clinical success and adverse events. DATA COLLECTION AND ANALYSIS: Data were independently extracted by three review authors. Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. The Cochrane Oral Health Group's statistical guidelines were followed. MAIN RESULTS: Only four RCTs were identified. Interventions examined included: Ledermix, glycerrhetinic acid/antibiotic mix, zinc oxide eugenol, calcium hydroxide, Cavitec, Life, Dycal, potassium nitrate, dimethyl isosorbide, and polycarboxylate cement. Only one study showed a statistically significant finding; potassium nitrate/dimethyl isosorbide/polycarboxylate cement resulted in fewer clinical symptoms than potassium nitrate/polycarboxylate cement or polycarboxylate cement alone when used as a capping material for carious pulps. AUTHORS' CONCLUSIONS: It was disappointing that there were so few studies which could be considered as being suitable for inclusion in this review. The findings from this review do not suggest that there should be any significant change from accepted conventional practice procedures when the pulp of the carious tooth is considered. Further well designed RCTs are needed to investigate the potential of contemporary materials which may be suitable when used in the management of carious teeth. It is recognised that it is difficult to establish the 'ideal' clinical study when ethical approval for new materials must be sought and strict attention to case selection, study protocol and interpretation of data is considered. It is also not easy to recruit sufficient numbers of patients meeting the necessary criteria.


Assuntos
Cárie Dentária/terapia , Doenças da Polpa Dentária/terapia , Polpa Dentária , Adulto , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Oncogenesis ; 6(9): e377, 2017 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-28892104

RESUMO

Lysine-specific demethylase 1A (LSD1, KDM1A) specifically demethylates di- and monomethylated histones H3K4 and K9, resulting in context-dependent transcriptional repression or activation. We previously identified an irreversible LSD1 inhibitor T-3775440, which exerts antileukemic activities in a subset of acute myeloid leukemia (AML) cell lines by inducing cell transdifferentiation. The NEDD8-activating enzyme inhibitor pevonedistat (MLN4924, TAK-924) is an investigational drug with antiproliferative activities in AML, and is also reported to induce cell differentiation. We therefore tested the combination of these two agents in AML models. The combination treatment resulted in synergistic growth inhibition of AML cells, accompanied by enhanced transdifferentiation of an erythroid leukemia lineage into granulomonocytic-like lineage cells. In addition, pevonedistat-induced rereplication stress during the S phase was greatly augmented by concomitant treatment with T-3775440, as reflected by the increased induction of apoptosis. We further demonstrated that the combination treatment was markedly effective in subcutaneous tumor xenograft models as well as in a disseminated model of AML, leading to tumor eradication or prolonged survival in T-3775440/pevonedistat cotreated mice. Our findings indicate the therapeutic potential of the combination of LSD1 inhibitors and pevonedistat for the treatment of AML.

10.
Br J Ophthalmol ; 90(7): 826-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16597665

RESUMO

AIMS: To establish a keratoprosthesis (Kpro) surgical technique that maintains an intact superficial corneal layer. METHODS: A manual microkeratome (Moria LSK-1) was used to create a 130 mum flap of approximately 10 mm diameter in the right eye of Japanese white rabbits. The stoma beneath the flap area was dissected before the removal of a 5.0 mm stromal disc. A 5.0 mm collagen I immobilised poly(vinyl alcohol) (COL-PVA) disc was placed on the exposed posterior stroma close to Descemet's membrane. The flap was repositioned and fixed using 10-0 nylon sutures, which were removed 2 days following surgery. The corneas were followed clinically by slit lamp microscopy and photographs. Rabbits were sacrificed after 6 months, and the transplanted corneas were examined histologically by haematoxylin and eosin staining and immunohistochemistry against vimentin and alpha-smooth muscle actin (alpha-SMA). RESULTS: The transplanted COL-PVA discs remained transparent throughout the study, with no complications related to the flap or overlying epithelium. The interface between COL-PVA and Descemet's membrane remained clear without signs of opacification caused by scarring or cellular deposition. Pathology revealed the intact COL-PVA polymer in the posterior stroma, with minimal cellular infiltration along the anterior and posterior interfaces. Immunohistology shows vimentin and alpha-SMA staining at levels comparable to lamellar keratoplasty control. CONCLUSIONS: Microkeratome assisted deep lamellar keratoprosthesis may be a safe technique for the transplantation of artificial hydrogels for therapeutic purposes.


Assuntos
Córnea/cirurgia , Microcirurgia/métodos , Implantação de Prótese/métodos , Animais , Transplante de Córnea/instrumentação , Transplante de Córnea/métodos , Feminino , Hidrogéis , Álcool de Polivinil , Coelhos , Retalhos Cirúrgicos , Cicatrização
11.
Nucleic Acids Res ; 28(12): 2353-62, 2000 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-10871367

RESUMO

Photolyase is a DNA repair enzyme that reverses UV-induced photoproducts in DNA in a light-dependent manner. Recently, photolyase homologs were identified in higher eukaryotes. These homologs, termed crypto-chromes, function as blue light photoreceptors or regulators of circadian rhythm. In contrast, most bacteria have only a single photolyase or photolyase-like gene. Unlike other microbes, the chromosome of the cyanobacterium SYNECHOCYSTIS: sp. PCC6803 contains two ORFs (slr0854 and sll1629) with high similarities to photolyases. We have characterized both genes. The slr0854 gene product exhibited specific, light-dependent repair activity for a cyclo-butane pyrimidine dimer (CPD), whereas the sll1629 gene product lacks measurable affinity for DNA in vitro. Disruption of either slr0854 or sll1629 had little or no effect on the growth rate of the cyanobacterium. A mutant lacking the slr0854 gene showed severe UV sensitivity, in contrast to a mutant lacking sll1629. Phylogenetic analysis showed that sll1629 is more closely related to the cryptochromes than photolyases. We conclude that sll1629 is a bacterial cryptochrome. To our knowledge, this is the first description of a bacterial cryptochrome.


Assuntos
Cianobactérias/genética , DNA Bacteriano/efeitos da radiação , Desoxirribodipirimidina Fotoliase/genética , Proteínas de Drosophila , Proteínas do Olho , Flavoproteínas/genética , Células Fotorreceptoras de Invertebrados , Raios Ultravioleta , Sequência de Bases , Criptocromos , Cianobactérias/crescimento & desenvolvimento , Cianobactérias/efeitos da radiação , Reparo do DNA , DNA Bacteriano/genética , Escuridão , Genes Bacterianos , Luz , Dados de Sequência Molecular , Filogenia , Receptores Acoplados a Proteínas G
12.
Biochim Biophys Acta ; 1291(1): 89-95, 1996 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-8781530

RESUMO

1,5-Anhydro-D-glucitol (AG) is a major polyol, 99.9% of which is reabsorbed by the kidney. However, such reabsorption is inhibited by competition with glucose excreted in excess, i.e., glucosuria. Under such conditions, AG is excreted into the urine. We administered various types of sugars to rats by continuous intravenous infusion for two hours to evaluate the competition between AG and these sugars for renal reabsorption in vivo. The reabsorption of AG was significantly inhibited by competition with fructose and mannose. The excretion of AG in the 120 min after a load of 3.64 mmol of fructose was 1.99 +/- 0.33 mumol, that after 3.64 mmol of mannose loading was 2.34 +/- 0.43 mumol. These levels were comparable to the AG excretion observed after the administration of the same amount of glucose (3.87 +/- 0.61 mumol). No competition was observed with sucrose, xylose, myoinositol or galactose. The reabsorption of fructose and mannose was significantly inhibited by the presence of AG (P < 0.001) after a mixed load. Results suggest that AG is reabsorbed in the renal tubule by an AG/fructose/mannose-common transport system that is distinct from the major glucose reabsorption system. These findings may help to clarify the specific transport systems for various sugars in the renal tubule, as well as their physiological importance.


Assuntos
Desoxiglucose/metabolismo , Frutose/metabolismo , Túbulos Renais/metabolismo , Manose/metabolismo , Proteínas de Transporte de Monossacarídeos/fisiologia , Absorção , Animais , Glicemia/análise , Carboidratos/sangue , Carboidratos/urina , Desoxiglucose/sangue , Desoxiglucose/farmacologia , Desoxiglucose/urina , Frutose/sangue , Frutose/farmacologia , Frutose/urina , Glicosúria/metabolismo , Masculino , Manose/sangue , Manose/farmacologia , Manose/urina , Ratos , Ratos Wistar
13.
Biochim Biophys Acta ; 1456(1): 27-34, 2000 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-10611453

RESUMO

The steady-state fluorescence properties and uphill energy transfer were analyzed on intact cells of a chlorophyll (Chl) d-dominating photosynthetic prokaryote, Acaryochloris marina. Observed spectra revealed clear differences, depending on the cell pigments that had been sensitized; using these properties, it was possible to assign fluorescence components to specific Chl pigments. At 22 degrees C, the main emission at 724 nm came from photosystem (PS) II Chl d, which was also the source of one additional band at 704 nm. Chl a emissions were observed at 681 nm and 671 nm. This emission pattern essentially matched that observed at -196 degrees C, as the main emission of Chl d was located at 735 nm, and three minor bands were observed at 704 nm, 683 nm, and 667 nm, originating from Chl d, Chl a, and Chl a, respectively. These three minor bands, however, had not been sensitized by carotenoids, suggesting specific localization in PS II. At 22 degrees C, excitation of the red edge of the absorption band (which, at 736 nm, was 20 nm longer than the absorption maximum), resulted in fluorescence bands of Chl d at 724 nm and of Chl a at 682 nm, directly demonstrating an uphill energy transfer in this alga. This transfer is a critical factor for in vivo activity, due to an inversion of energy levels between antenna Chl d and the primary electron donor of Chl a in PS II.


Assuntos
Clorofila/química , Eucariotos/química , Complexo de Proteínas do Centro de Reação Fotossintética/química , Transferência de Energia , Complexos de Proteínas Captadores de Luz , Espectrometria de Fluorescência , Temperatura
14.
Biochim Biophys Acta ; 1217(2): 199-202, 1994 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8110835

RESUMO

We have isolated a novel human gene and cDNA encoding a member of the regI proteins, regI beta. The gene encodes a 166-amino acid protein which has 22 amino acid substitutions in comparison with the previously isolated human reg protein, regI alpha. RegI beta was expressed only in pancreas, whereas regI alpha was expressed in kidney and stomach as well as in pancreas.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Glicoproteínas , Proteínas do Tecido Nervoso , Pâncreas/metabolismo , Sequência de Aminoácidos , Sequência de Bases , DNA Complementar/análise , Expressão Gênica , Humanos , Litostatina , Dados de Sequência Molecular
15.
Biochim Biophys Acta ; 1219(1): 241-3, 1994 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-8086472

RESUMO

We report here the characterization of the 5'-regulatory region of rat Reg I gene encoding a growth stimulating factor for pancreatic beta-cells. Transient expression assays of the 5'-flanking region/luciferase fusion gene in AR4-2J cells showed that the -304/-237 region contained positive cis-acting elements. Gel shift assays using AR4-2J and rat pancreas nuclear extracts showed the formation of a specific complex with the -256/-237 oligonucleotide.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Proteínas do Tecido Nervoso , Ratos Wistar/genética , Sequências Reguladoras de Ácido Nucleico/genética , Animais , Sequência de Bases , Proteínas de Ligação ao Cálcio/biossíntese , Análise Mutacional de DNA , Proteínas de Ligação a DNA/metabolismo , Genes Reporter , Litostatina , Luciferases/biossíntese , Luciferases/genética , Camundongos , Dados de Sequência Molecular , Proteínas Nucleares/metabolismo , Pâncreas/metabolismo , Ligação Proteica , Ratos , Proteínas Recombinantes de Fusão/biossíntese , Deleção de Sequência , Homologia de Sequência do Ácido Nucleico
16.
Biochim Biophys Acta ; 1412(3): 250-61, 1999 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-10482787

RESUMO

We investigated the localization, structure and function of the biliproteins of the oxygenic photosynthetic prokaryote Acaryochloris marina, the sole organism known to date that contains chlorophyll d as the predominant photosynthetic pigment. The biliproteins were isolated by means of sucrose gradient centrifugation, ion exchange and gel filtration chromatography. Up to six biliprotein subunits in a molecular mass range of 15.5-18.4 kDa were found that cross-reacted with antibodies raised against phycocyanin or allophycocyanin from a red alga. N-Terminal sequences of the alpha- and beta-subunits of phycocyanin showed high homogeneity to those of cyanobacteria and red algae, but not to those of cryptomonads. As shown by electron microscopy, the native biliprotein aggregates are organized as rod-shaped structures and located on the cytoplasmic side of the thylakoid membranes predominantly in unstacked thylakoid regions. Biochemical and spectroscopic analysis revealed that they consist of four hexameric units, some of which are composed of phycocyanin alone, others of phycocyanin together with allophycocyanin. Spectroscopic analysis of isolated photosynthetic reaction center complexes demonstrated that the biliproteins are physically attached to the photosystem II complexes, transferring light energy to the photosystem II reaction center chlorophyll d with high efficiency.


Assuntos
Clorofila/química , Ficocianina/química , Ficoeritrina/química , Células Procarióticas/química , Sequência de Aminoácidos , Cianobactérias , Complexos de Proteínas Captadores de Luz , Dados de Sequência Molecular , Complexo de Proteínas do Centro de Reação Fotossintética/química , Complexo de Proteína do Fotossistema II , Ficobilinas , Rodófitas
17.
Biochim Biophys Acta ; 1412(1): 37-46, 1999 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-10354492

RESUMO

Antenna components and the primary electron donor of the photosystem (PS) II in the Chlorophyll (Chl) d-dominating prokaryote, Acaryochloris marina, were studied using time-resolved fluorescence spectroscopy in the ps time range. By selective excitation of Chl a or Chl d, differences in fluorescence properties were clearly resolved. At physiological temperature, energy transfer was confirmed by a red shift of emission maximum among PS II antenna components, and the equilibrium of energy distribution among Chl a and Chl d was established within 30 ps. A fluorescence component that can be assigned to delayed fluorescence (DF) was observed at 10 ns after the excitation; however, it was not necessarily resolved by the decay kinetics. At -196 degrees C, a red shift of emission maximum was reproduced but the equilibrium of energy distribution was not detected. DF was resolved in the wavelength region corresponding to Chl a by spectra and by decay kinetics. The lifetime of the DF was estimated to be approx. 15 ns, and the peaks were located at 681 and 695 nm, significantly shorter wavelengths than those of Chl d. These findings strongly suggest that an origin of DF is Chl a, and Chl a is most probably the primary electron donor in the PS II reaction center (RC). These results indicate that the constitution of PS II RC in this alga is essentially identical to that of other oxygenic photosynthetic organisms.

18.
Diabetes ; 38(6): 723-9, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2656341

RESUMO

To elucidate the value of using plasma 1,5-anhydro-D-glucitol (AG) as a marker of glycemic control in diabetic patients, the relationship between the plasma concentration of AG and glucosuria was examined in 152 patients with non-insulin-dependent diabetes mellitus (NIDDM). After recovery from the deterioration of glycemic control in NIDDM patients had started, AG began to increase day by day. The recovery of plasma AG showed a constant linear increase curve when excellent glycemic control was attained. The ordinary daily recovery rate of plasma AG was estimated to be 0.3 microgram/ml, which was independent of body weight, sex, age, the difference in treatment, the duration of diabetes, or the level of plasma AG among NIDDM patients. This rate decreased according to the increase in urinary glucose. When we calculated the decrease rate of plasma AG (delta AG), assuming 0.3 microgram/day to be the maximum increase rate in a day, we found a high correlation between delta AG and urinary glucose at almost all AG levels except the normal range and observed that plasma AG (A) times urinary glucose (G) was relatively constant. The formula A x G = 16 is a simple equation for rough estimation of urinary glucose from the plasma AG concentration in a stable glycemic-controlled NIDDM patient, and we call it the A.G index. The plasma AG also correlated significantly with fasting plasma glucose (r = -.810) and glycosylated hemoglobin (r = -.856) in the same stable glycemic-controlled NIDDM patients. Based on these observations, we propose that plasma AG can serve as a new marker that may provide sensitive and analytical information about glycemic control.


Assuntos
Biomarcadores/sangue , Glicemia/metabolismo , Desoxiaçúcares/sangue , Desoxiglucose/sangue , Diabetes Mellitus Tipo 2/sangue , Adulto , Idoso , Glicemia/análise , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/urina , Jejum , Feminino , Glicosúria , Humanos , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Gravidez , Gravidez em Diabéticas/sangue
19.
J Mol Biol ; 267(5): 1247-57, 1997 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-9150409

RESUMO

Specific molecular interactions involved in catalysis by antibody 6D9 were investigated by site-directed mutagenesis. The catalytic antibody 6D9, which was generated against a transition state analog (III), hydrolyzes a non-bioactive chloramphenicol monoester derivative (I) to produce chloramphenicol (II). Construction of a three-dimensional molecular model of 6D9 and sequence comparison within a panel of related antibodies suggested candidates for catalytic residues, His (L27d), Tyr (L32), Tyr (H58) and Arg (H100b); these were targeted for the site-directed mutagenesis study. The Y-H58-F and R-H100b-A mutants possessed catalytic activities comparable to that of the wild-type, and the Y-H58-H and Y-L32-F mutant displayed an approximately fivefold decrease in k(cat)/Km. In the transition state analysis, the plots of logK(TSA) versus log(k(cat)/Km) for the mutants are linear, with a slope of approximately 1.0, indicating that the entire hapten-binding energy in the mutants is also utilized to bind the transition state and to accelerate the catalysis. In addition, a dramatic change in the catalytic activity was observed when the histidine residue (27d) in the CDR1 light chain was replaced with alanine. The H-L27d-A mutant had no detectable catalytic activity. This mutation led to a large, 40-fold reduction in transition state binding, with no change in substrate binding. Coupled with the previous kinetic studies and chemical modifications of the intact 6D9 antibody, this mutagenesis study has demonstrated that His L27d plays an essential role in stabilization of the transition state, the mechanism of catalysis by the 6D9 antibody.


Assuntos
Anticorpos Catalíticos/metabolismo , Sítios de Ligação de Anticorpos , Histidina/metabolismo , Fragmentos de Imunoglobulinas/metabolismo , Região Variável de Imunoglobulina/metabolismo , Sequência de Aminoácidos , Anticorpos Catalíticos/genética , Sítios de Ligação de Anticorpos/genética , Cloranfenicol/biossíntese , Análise Mutacional de DNA , Ésteres/metabolismo , Histidina/genética , Hidrólise , Fragmentos de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Pró-Fármacos/metabolismo
20.
Br J Ophthalmol ; 89(2): 134-7, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15665339

RESUMO

AIMS: To evaluate the histology and function of Descemet's membrane transplanted with intact endothelium. METHODS: Japanese white rabbits and human eyebank eyes were used as donors and recipients of Descemet's membrane transplantation. Donor endothelium was hydrodissected by injecting indocyanine green from a limbal incision, and then processed as a corneal scleral button. A 6 mm diameter donor sheet was trephined, and folded in half using a 6 mm diameter polymer as a carrier. Recipient endothelium was also hydrodissected from the limbus using trypan blue to stain the Descemet's membrane. Continuous curvilinear descemetorhexis (CCD) was performed to remove a circular section of the Descemet's membrane using a 27 gauge cystotome. Donor tissue was inserted into the anterior chamber through a 5 mm limbal incision and apposed to the host stroma. Polymers were removed following transplantation. Similar surgical procedures were performed in both rabbits and eyebank eyes. Haematoxylin eosin stains were performed after 28 days in rabbits, and eyebank eyes were fixed immediately following surgery for endothelial cell counts. RESULTS: Rabbit control eyes demonstrated stromal oedema caused by loss of Descemet's membrane, whereas transplanted eyes had clear corneas. The mean (standard deviation) pachymetry of operated eyes was 376.6 (SD 32.5) mum compared with 389.6 (SD 25.1) mum in the unoperated eye. Mean endothelial density immediately following surgery in eyebank eyes was 2749 (SD 288) cells/mm(2). CONCLUSIONS: Transplantation of Descemet's membrane by CCD produces a functional graft with an optically clear interface similar to control cornea.


Assuntos
Transplante de Córnea/métodos , Lâmina Limitante Posterior/transplante , Metacrilatos , Animais , Contagem de Células , Córnea/patologia , Lâmina Limitante Posterior/patologia , Células Endoteliais/patologia , Endotélio/patologia , Endotélio/transplante , Feminino , Humanos , Coelhos
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