Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Arthritis Res Ther ; 22(1): 97, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32349791

RESUMO

OBJECTIVES: To systematically review the impact of tapering targeted therapies (bDMARDs or JAKis) on the risk of serious infections and severe adverse events (SAEs) in patients with rheumatoid arthritis (RA) or axial spondyloarthritis (axSpA) in remission or low disease activity (LDA) state. MATERIALS AND METHODS: A meta-analysis based on a systematic review of PubMed, Embase, Cochrane, until August 2019, as well as relevant databases of international conferences, was used to evaluate the risk difference (RD) at 95% confidence interval (95% CI) of incidence density of serious infections, SAEs, malignancies, cardiovascular adverse events (CV AEs), or deaths after tapering (dose reduction or spacing) compared to continuation of targeted therapies. RESULTS: Of the 1957 studies initially identified, 13 controlled trials (9 RA and 4 SpA trials) were included in the meta-analysis. 1174 patient-years were studied in the tapering group (TG) versus 1086 in the usual care group (UC). There were 1.7/100 patient-year (p-y) serious infections in TG versus 2.6/100 p-y in UC (RD (95% CI) 0.01 (0.00 to 0.02), p = 0.13) and 7.4/100 p-y SAEs in TG versus 6.7/100 p-y in UC (RD 0.00 (- 0.02 to 0.02), p = 0.82). The risk of malignancies, CV AEs, or deaths did not differ between the tapering and the usual care groups. Subgroup analysis (RA and SpA) detected no significant differences between the two groups. CONCLUSION: We could not show significant impact of tapering bDMARD or JAKi over continuation concerning the risk of serious infections, SAEs, malignancies, CV AEs, or deaths in RA and SpA patients in remission or LDA state.


Assuntos
Antirreumáticos/administração & dosagem , Artrite Reumatoide , Produtos Biológicos/administração & dosagem , Janus Quinases/antagonistas & inibidores , Espondilartrite , Inibidores do Fator de Necrose Tumoral/administração & dosagem , Antirreumáticos/efeitos adversos , Artrite Reumatoide/tratamento farmacológico , Ensaios Clínicos Controlados como Assunto , Humanos , Espondilartrite/tratamento farmacológico
2.
Sci Rep ; 7: 39997, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28054672

RESUMO

We report the quantum efficiency of photoluminescence processes of Er optical centers as well as the thermal quenching mechanism in GaN epilayers prepared by metal-organic chemical vapor deposition. High resolution infrared spectroscopy and temperature dependence measurements of photoluminescence intensity from Er ions in GaN under resonant excitation excitations were performed. Data provide a picture of the thermal quenching processes and activation energy levels. By comparing the photoluminescence from Er ions in the epilayer with a reference sample of Er-doped SiO2, we find that the fraction of Er ions that emits photon at 1.54 µm upon a resonant optical excitation is approximately 68%. This result presents a significant step in the realization of GaN:Er epilayers as an optical gain medium at 1.54 µm.

3.
Ann Rheum Dis ; 76(1): 29-42, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27457514

RESUMO

BACKGROUND: New drugs and new evidence concerning the use of established treatments have become available since the publication of the first European League Against Rheumatism (EULAR) recommendations for the management of gout, in 2006. This situation has prompted a systematic review and update of the 2006 recommendations. METHODS: The EULAR task force consisted of 15 rheumatologists, 1 radiologist, 2 general practitioners, 1 research fellow, 2 patients and 3 experts in epidemiology/methodology from 12 European countries. A systematic review of the literature concerning all aspects of gout treatments was performed. Subsequently, recommendations were formulated by use of a Delphi consensus approach. RESULTS: Three overarching principles and 11 key recommendations were generated. For the treatment of flare, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), oral or intra-articular steroids or a combination are recommended. In patients with frequent flare and contraindications to colchicine, NSAIDs and corticosteroids, an interleukin-1 blocker should be considered. In addition to education and a non-pharmacological management approach, urate-lowering therapy (ULT) should be considered from the first presentation of the disease, and serum uric acid (SUA) levels should be maintained at<6 mg/dL (360 µmol/L) and <5 mg/dL (300 µmol/L) in those with severe gout. Allopurinol is recommended as first-line ULT and its dosage should be adjusted according to renal function. If the SUA target cannot be achieved with allopurinol, then febuxostat, a uricosuric or combining a xanthine oxidase inhibitor with a uricosuric should be considered. For patients with refractory gout, pegloticase is recommended. CONCLUSIONS: These recommendations aim to inform physicians and patients about the non-pharmacological and pharmacological treatments for gout and to provide the best strategies to achieve the predefined urate target to cure the disease.


Assuntos
Supressores da Gota/uso terapêutico , Gota/tratamento farmacológico , Corticosteroides/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Técnica Delphi , Aconselhamento Diretivo , Medicina Baseada em Evidências , Gota/sangue , Gota/terapia , Humanos , Interleucina-1/antagonistas & inibidores , Estilo de Vida , Educação de Pacientes como Assunto , Exacerbação dos Sintomas , Ácido Úrico/sangue
4.
Lupus ; 23(1): 69-74, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24213308

RESUMO

Objective To evaluate the extended follow-up of the CYCLOFA-LUNE trial, a randomized prospective trial comparing two sequential induction and maintenance treatment regimens for proliferative lupus nephritis based either on cyclophosphamide (CPH) or cyclosporine A (CyA). Patients and methods Data for kidney function and adverse events were collected by a cross-sectional survey for 38 of 40 patients initially randomized in the CYCLOFA-LUNE trial. Results The median follow-up time was 7.7 years (range 5.0-10.3). Rates of renal impairment and end-stage renal disease, adverse events (death, cardiovascular event, tumor, premature menopause) did not differ between the CPH and CyA group, nor did mean serum creatinine, 24 h proteinuria and SLICC damage score at last follow-up. Most patients in both groups were still treated with glucocorticoids, other immunosuppressant agents and blood pressure lowering drugs. Conclusion An immunosuppressive regimen based on CyA achieved similar clinical results to that based on CPH in the very long term.


Assuntos
Ciclofosfamida/efeitos adversos , Ciclosporina/efeitos adversos , Imunossupressores/efeitos adversos , Nefrite Lúpica/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Proliferação de Células/efeitos dos fármacos , Seguimentos , Humanos , Nefrite Lúpica/patologia , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/patologia
5.
Prague Med Rep ; 112(4): 298-304, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22142525

RESUMO

Although very rare in a European context, a bite from the black mamba Dendroaspis polylepis is an event that poses an immediate threat to life. Given the content of neurotoxins in the snake's venom, the mortality of envenomation reaches 100% in almost every case if ventilation is not provided in a timely manner and adequate therapy initiated. The report describes a case of a snake breeder being envenomed. This 31-year-old man was bitten by a black mamba on his finger, and who subsequently developed clinical symptoms of envenoming typical for the species. Thanks to mechanical ventilation being employed promptly, with myorelaxation during generalized muscle fasciculations, and particularly owing to the eventual antivenin therapy, the patient's condition settled without consequences. In addition to describing the given case in detail, the paper discusses the composition and mechanisms of action of black mamba venom, while providing guidelines for adequate therapy.


Assuntos
Elapidae , Mordeduras de Serpentes , Adulto , Animais , Antivenenos/uso terapêutico , Venenos Elapídicos , Humanos , Masculino , Mordeduras de Serpentes/diagnóstico , Mordeduras de Serpentes/fisiopatologia , Mordeduras de Serpentes/terapia
6.
Urol Int ; 87(1): 120-4, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21734351
7.
Br J Cancer ; 103(7): 1057-65, 2010 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-20736942

RESUMO

BACKGROUND: Tumour necrosis reflects the presence of hypoxia, which can be indicative of an aggressive tumour phenotype. The aim of this study was to investigate whether histological necrosis is a useful predictor of outcome in patients with pancreatic ductal carcinoma (PDC). METHODS: We reviewed histopathological findings in 348 cases of PDC in comparison with clinicopathological information. We counted small necrotic foci (micronecrosis) as necrosis, in addition to massive necrosis that had been only defined as necrosis in previous studies. The reproducibility of identifying histological parameters was tested by asking five independent observers to blindly review 51 examples of PDC. RESULTS: Both micronecrosis and massive necrosis corresponded to hypoxic foci expressing carbonic anhydrase IX detected by immunohistochemistry. Multivariate survival analysis showed that histological necrosis was an independent predictor of poor outcome in terms of both disease-free survival (DFS) and disease-specific survival (DSS) of PDC patients. In addition, metastatic status, and lymphatic, venous, and intrapancreatic neural invasion were independent prognostic factors for shorter DFS and metastatic status, margin status, lymphatic invasion, and intrapancreatic neural invasion were independent prognostic factors for DSS. The interobserver reproducibility of necrosis identification among the five independent observers was 'almost perfect' (κ-value of 0.87). CONCLUSION: Histological necrosis is a simple, accurate, and reproducible predictor of postoperative outcome in PDC patients.


Assuntos
Antígenos de Neoplasias/metabolismo , Anidrases Carbônicas/metabolismo , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/patologia , Anidrase Carbônica IX , Carcinoma Ductal Pancreático/mortalidade , Hipóxia Celular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/cirurgia , Período Pós-Operatório , Prognóstico , Reprodutibilidade dos Testes
8.
Lupus ; 19(11): 1281-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20605876

RESUMO

Intravenous cyclophosphamide is considered to be the standard of care for the treatment of proliferative lupus nephritis. However, its use is limited by potentially severe toxic effects. Cyclosporine A has been suggested to be an efficient and safe treatment alternative to cyclophosphamide. Forty patients with clinically active proliferative lupus nephritis were randomly assigned to one of two sequential induction and maintenance treatment regimens based either on cyclophosphamide or Cyclosporine A. The primary outcomes were remission (defined as normal urinary sediment, proteinuria <0.3 g/24 h, and stable s-creatinine) and response to therapy (defined as stable s-creatinine, 50% reduction in proteinuria, and either normalization of urinary sediment or significant improvement in C3) at the end of induction and maintenance phase. Secondary outcomes were incidence of adverse events, and relapse-free survival. At the end of the induction phase, 24% of the 21 patients treated by cyclophosphamide achieved remission, and 52% achieved response, as compared with 26% and 43%, respectively of the 19 patients treated by the Cyclosporine A. At the end of the maintenance phase, 14% of patients in cyclophosphamide group, and 37% in Cyclosporine A group had remission, and 38% and 58% respectively response. Treatment with Cyclosporine A was associated with transient increase in blood pressure and reversible decrease in glomerular filtration rate. There was no significant difference in median relapse-free survival. In conclusion, Cyclosporine A was as effective as cyclophosphamide in the trial of sequential induction and maintenance treatment in patients with proliferative lupus nephritis and preserved renal function.(ClinicalTrials.gov identifier: NCT00976300)


Assuntos
Ciclofosfamida , Ciclosporina/uso terapêutico , Imunossupressores , Nefrite Lúpica/tratamento farmacológico , Adulto , Ciclofosfamida/administração & dosagem , Ciclofosfamida/uso terapêutico , Feminino , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Infusões Intravenosas , Testes de Função Renal , Nefrite Lúpica/diagnóstico , Masculino , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
9.
Rozhl Chir ; 88(2): 62-4, 2009 Feb.
Artigo em Tcheco | MEDLINE | ID: mdl-19413261

RESUMO

Authors present a case report of the young man, Afghan military policeman, who was with gunshot injury referred to treatment to the Czech field hospital stationed in Kabul international airport at the time of the 4th contingent of the field hospital and chemical unit in international operation ISAF Afghanistan. The patient suffered from a double gunshot of the chest wall that caused open compound fracture of the left collar bone, fracture of the sternal bone and the right scapula and hemorhagic contusion of the left apical lung although it was not a penetrating injury of the chest. Left side posterolateral thoracotomy was performed and non-anatomical resection of the apical lung and further drainage of the pleural cavity were done. Revision of both the gunshot canals with debridements was further performed, of course. Postoperative course was without any complications and patient was sent to local Afghan hospital on the sixth postoperative day.


Assuntos
Traumatismos Torácicos/cirurgia , Ferimentos por Arma de Fogo/cirurgia , Adulto , Campanha Afegã de 2001- , Humanos , Masculino , Militares , Traumatismos Torácicos/patologia , Ferimentos por Arma de Fogo/patologia , Adulto Jovem
10.
Neoplasma ; 56(4): 298-302, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19473055

RESUMO

We investigated the expression of cell-associated CAIX protein in histological sections of the transitional cell carcinoma (TCC) of the urinary tract and of the soluble form of CAIX (s-CAIX) shed by the tumor into the serum and urine of TCC patients. A total of 23 patients with histologically confirmed TCC or squamous cell carcinoma (SCC) were enrolled in the pilot study. Sixteen healthy individuals served as controls. Membrane-bound CAIX was present in the tumor cells near the endoluminal surface. Necrosis was observed in only 4 samples. Using Western blots, s-CAIX concentrated from urine was visualized as a double band at 50 and 54 kDa. In most cases, the presence of s-CAIX in the urine correlated with CAIX expression in the tumor. On the other hand, s-CAIX did not exceed the normal level in the serum of TCC patients. Urine from patients with TCC of the urinary bladder and renal pelvis contained s-CAIX, allowing the detection of tumors in approximately 70% of the patients. Moreover, two additional patients with suspected, but unconfirmed bladder tumor, with s-CAIX detected in urine, developed tumors identified as TCC within six months. We suggest that after a simple, rapid and sensitive test, monitoring s-CAIX levels in urine will be developed, it may be useful for early detection of relapse in patients following transurethral tumor resection.


Assuntos
Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/metabolismo , Anidrases Carbônicas/metabolismo , Carcinoma de Células de Transição/enzimologia , Pelve Renal/enzimologia , Bexiga Urinária/enzimologia , Neoplasias Urológicas/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Anidrase Carbônica IX , Carcinoma de Células de Transição/sangue , Carcinoma de Células de Transição/urina , Estudos de Casos e Controles , Membrana Celular/enzimologia , Membrana Celular/patologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Técnicas Imunoenzimáticas , Pelve Renal/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Projetos Piloto , Prognóstico , Bexiga Urinária/patologia , Neoplasias Urológicas/sangue , Neoplasias Urológicas/urina , Adulto Jovem
11.
Phys Rev Lett ; 101(14): 147206, 2008 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-18851569

RESUMO

The role of graphene in mediating the exchange interaction is theoretically investigated when placed between two ferromagnetic dielectric materials. The calculation based on a tight-binding model illustrates that the magnetic interactions at the interfaces affect not only the graphene band structure but also the thermodynamic potential of the system, leading to an effective exchange bias between magnetic layers. The analysis indicates a strong dependence of the exchange bias on the properties of the mediating layer, revealing an efficient mechanism of electrical control even at room temperature.

12.
Folia Biol (Praha) ; 54(3): 73-80, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18647546

RESUMO

Nephrologists deal with a host of pathologic conditions involving renal and systemic endothelium. Both in native and transplanted kidneys, often the insult to the renal endothelium initiates the pathogenic process ultimately leading to the loss of organ function. Also, systemic atherosclerosis is accelerated in patients with renal dysfunction. In this review we would like to cover the possible role of CECs and their counterparts--circulating EPCs in the pathogenesis of endothelial dysfunction associated with chronic renal failure, ANCA-associated vasculitis, and progression of chronic renal disease.


Assuntos
Células Endoteliais/fisiologia , Falência Renal Crônica/patologia , Células-Tronco/fisiologia , Anticorpos Anticitoplasma de Neutrófilos/sangue , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Biomarcadores , Contagem de Células , Humanos , Transplante de Rim/patologia , Vasculite/etiologia , Vasculite/patologia
14.
Br J Cancer ; 89(6): 1067-71, 2003 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-12966427

RESUMO

Tumour-associated protein carbonic anhydrase IX (CA IX) has two major forms. One is a cell-associated, transmembrane protein seen on Western blots as a twin band of 54/58 kDa, expressed in gastric mucosa and in several types of cancer. The other is a soluble protein s-CA IX of 50/54 kDa, which is released into the culture medium or into the body fluids, most likely by proteolytic cleavage of the extracellular part from transmembrane and intracellular sequences. While TC media of CA IX-positive tumour cell lines or short-term cultures of tumour explants contain a relatively high concentration of s-CA IX (20-50 ng ml(-1)), the level of this antigen in blood serum and urine of renal clear cell carcinoma patients is about 1000 x lower. The concentration of CA IX in the blood and in urine varies within wide limits and there is no obvious correlation with tumour size. After nephrectomy, s-CA IX is cleared from the blood within a few days. Only an extremely low concentration of CA IX was detectable in the sera and in urine of control individuals.


Assuntos
Antígenos de Neoplasias/sangue , Antígenos de Neoplasias/urina , Anidrases Carbônicas/sangue , Anidrases Carbônicas/urina , Carcinoma de Células Renais/enzimologia , Neoplasias Renais/enzimologia , Proteínas de Neoplasias/sangue , Proteínas de Neoplasias/urina , Adulto , Idoso , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/urina , Northern Blotting , Anidrase Carbônica IX , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Membrana Celular/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Células Tumorais Cultivadas
15.
Physiol Res ; 52(4): 433-7, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12899655

RESUMO

The pathogenesis of arterial hypertension in autosomal dominant polycystic kidney disease (ADPKD) is complex and likely dependent on interaction of hemodynamic, endocrine and neurogenic factors. We decided to evaluate the role of endothelin (ET1) and nitric oxide (NO) in the regulation of arterial blood pressure (BP) and to determine plasma levels of ET1 and NO in the group of patients with ADPKD. The ADPKD group (18 patients, 6 men + 12 women, mean age 44.6+/-11.7 years, with creatinine clearancecorrig > 1.1 ml/s) was compared with a control group of 27 healthy volunteers of comparable age. Plasma levels of ET1 assessed by direct RIA determination in the group of ADPKD patients (11.03+/-1.8 fmol/ml) were significantly increased (p<0.001) in comparison with the control group (2.66+/-0.58 fmol/ml), while no significant differences were observed between normotensive and hypertensive patients in the ADPKD group. Serum levels of NO were evaluated according to the determination of serum levels of their metabolites - nitrites/nitrates. Serum levels of NO in the group of ADPKD patients (39.85+/-.38 micro mol/l) were significantly higher (p<0.05) in comparison with the control group (22.7+/-1.20 micro mol/l), whereas in the ADPKD group no significant differences were observed between normotensive and hypertensive patients. Thus, our study supports the concept of complex alteration of both vasoconstrictor and vasodilator systems in the pathogenesis of arterial hypertension in ADPKD.


Assuntos
Endotelina-1/fisiologia , Hipertensão/etiologia , Óxido Nítrico/fisiologia , Rim Policístico Autossômico Dominante/complicações , Adulto , Idoso , Antioxidantes/metabolismo , Doença Crônica , Creatina/metabolismo , Endotelina-1/sangue , Feminino , Taxa de Filtração Glomerular , Humanos , Hipertensão/enzimologia , Hipertensão/fisiopatologia , Peroxidação de Lipídeos/fisiologia , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/sangue , Rim Policístico Autossômico Dominante/enzimologia , Rim Policístico Autossômico Dominante/fisiopatologia
16.
Rozhl Chir ; 82(12): 645-51, 2003 Dec.
Artigo em Tcheco | MEDLINE | ID: mdl-14746235

RESUMO

The paper describes the advantages and disadvantages of the laparoscopic operations, the number of which steadily rises in urology. The laparoscopic surgery is considered to be a benefit regarding the short postoperative hospital stay, painless postoperative course, and virtually non-existing postoperative paralytic ileus. As disadvantage are deemed the long learning curve for the operating personal, and high economical costs, which could be cut down only if short off-work period in productive population is included. In the paper, the pathophysiological guidelines are outlined and emphasized during the laparoscopic operation, which the surgical and anesthesiological teams have to have in mind. On the own cohort of patients, the numbers and types of operations are described, which have been done at our department.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Urológicos , Adulto , Idoso , Humanos , Laparoscopia/efeitos adversos , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Urológicos/efeitos adversos
17.
Vnitr Lek ; 48(11): 1011-6, 2002 Nov.
Artigo em Tcheco | MEDLINE | ID: mdl-12577451

RESUMO

Case-control study comparing 81 patients with chronic renal failure (CRF) with 58 patients without renal disease who were evaluated by endoscopy of upper and/or lower gastrointestinal tract (GIT) for gastrointestinal bleeding or dyspepsia. The success of endoscopic examinations was the same in both groups. Patients with CRF more often underwent endoscopic examination because of gastrointestinal bleeding and they presented more often by hematochezia. Patients with CRF were more often found to have hemorrhagic gastropathy or duodenopathy and angiodysplasia of upper and lower GIT. However, duodenal ulcer was significantly more common in the control group without renal disease. Incidence of Helicobacter Pylori infection was low in both groups.


Assuntos
Endoscopia Gastrointestinal , Hemorragia Gastrointestinal/diagnóstico , Falência Renal Crônica/complicações , Feminino , Hemorragia Gastrointestinal/etiologia , Humanos , Masculino , Estudos Retrospectivos
18.
J Org Chem ; 66(13): 4595-600, 2001 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-11421779

RESUMO

Heptakis(2,3,6-tri-O-allyl)-beta-cyclodextrin 2 was converted to heptakis[2,3,6-tri-O-(2,3-dihydroxypropyl)]-beta-cyclodextrin 3 by osmium tetroxide-catalyzed dihydroxylation. A diastereomeric mixture of 3 was treated with sodium periodate followed by sodium borohydride to give heptakis[2,3,6-tri-O-(2-hydroxyethyl)]-beta-cyclodextrin 5 in 86% yield. Compound 5 could be quantitatively transformed into heptakis(2,3,6-tri-O-carboxymethyl)-beta-cyclodextrin 6 by TEMPO-mediated oxidation. The same reaction sequence was also applied to heptakis(2,6-di-O-allyl-3-O-methyl)-beta-cyclodextrin 8, heptakis(2,3-di-O-allyl-6-O-methyl)-beta-cyclodextrin 12, and heptakis(2,3-di-O-allyl-6-O-butyl)-beta-cyclodextrin 16; the analogous corresponding hydroxyethyl and carboxymethyl derivatives were isolated in high yields. All products were proved to be chemically uniform.


Assuntos
Ciclodextrinas/síntese química , Aditivos Alimentares/síntese química , beta-Ciclodextrinas , Ciclodextrinas/química , Aditivos Alimentares/química
19.
Am J Pathol ; 158(3): 905-19, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11238039

RESUMO

An acidic extracellular pH is a fundamental property of the malignant phenotype. In von Hippel-Lindau (VHL)-defective tumors the cell surface transmembrane carbonic anhydrase (CA) CA9 and CA12 genes are overexpressed because of the absence of pVHL. We hypothesized that these enzymes might be involved in maintaining the extracellular acidic pH in tumors, thereby providing a conducive environment for tumor growth and spread. Using Northern blot analysis and immunostaining with specific antibodies we analyzed the expression of CA9 and CA12 genes and their products in a large sample of cancer cell lines, fresh and archival tumor specimens, and normal human tissues. Expression was also analyzed in cultured cells under hypoxic conditions. Expression of CA IX and CA XII in normal adult tissues was detected only in highly specialized cells and for most tissues their expression did not overlap. Analysis of RNA samples isolated from 87 cancer cell lines and 18 tumors revealed high-to-moderate levels of expression of CA9 and CA12 in multiple cancers. Immunohistochemistry revealed high-to-moderate expression of these enzymes in various normal tissues and multiple common epithelial tumor types. The immunostaining was seen predominantly on the cell surface membrane. The expression of both genes was markedly induced under hypoxic conditions in tumors and cultured tumor cells. We conclude that the cell surface trans-membrane carbonic anhydrases CA IX and CA XII are overexpressed in many tumors suggesting that this is a common feature of cancer cells that may be required for tumor progression. These enzymes may contribute to the tumor microenvironment by maintaining extracellular acidic pH and helping cancer cells grow and metastasize. Our studies show an important causal link between hypoxia, extracellular acidification, and induction or enhanced expression of these enzymes in human tumors.


Assuntos
Anidrases Carbônicas/biossíntese , Hipóxia Celular , Concentração de Íons de Hidrogênio , Neoplasias/enzimologia , Neoplasias/etiologia , Biomarcadores Tumorais/biossíntese , Northern Blotting , Anidrases Carbônicas/genética , Anidrases Carbônicas/imunologia , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/enzimologia , Técnicas de Cultura de Células/métodos , Diferenciação Celular , Divisão Celular , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioblastoma/enzimologia , Humanos , Imuno-Histoquímica , Neoplasias Renais/diagnóstico , Neoplasias Renais/enzimologia , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Modelos Biológicos , Neoplasias/genética , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Células Tumorais Cultivadas
20.
Br J Cancer ; 82(11): 1808-13, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10839295

RESUMO

MN/CA IX is a cell surface protein, strongly associated with several types of human carcinomas. It exerts activity of carbonic anhydrase and capacity of binding to cell surface receptors. In the present work, we used affinity purified MN/CA IX protein to demonstrate that the cells adhere to immobilized MN/CA IX and that the monoclonal antibody M75 abrogates cell attachment to MN/CA IX. Using synthetic oligopeptides, we identified M75 epitope and located it in the proteoglycan domain, which contains a sixfold tandem repeat of six amino acids GEEDLP. From phage display library of random heptapeptides we identified and chemically synthesized those which compete for the epitope with M75 and inhibit adhesion of cells to MN/CA IX. These heptapeptides might serve as lead compounds for drug design.


Assuntos
Moléculas de Adesão Celular/metabolismo , Adesão Celular , Mapeamento de Epitopos , Proteínas de Neoplasias/metabolismo , Sequência de Aminoácidos , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/imunologia , Cromatografia de Afinidade , Ensaio de Imunoadsorção Enzimática , Humanos , Dados de Sequência Molecular , Proteínas de Neoplasias/química , Proteínas de Neoplasias/imunologia , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...