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1.
Zhonghua Bing Li Xue Za Zhi ; 47(10): 743-746, 2018 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-30317727

RESUMO

Objective: To investigate the expression of Apelin and Snail proteins in breast cancer and their relationship with the clinicopathological features and prognosis. Methods: The expression of Apelin and Snail proteins was detected by immunohistochemistry in 89 cases of breast cancer and 50 cases of mammary adenosis collected from January to June in 2008 at Fujian Cancer Hospital; the expression was correlated with the clinicopathological features and outcome of the patients. Results: Apelin and Snail were expressed in 42 cases(47.2%)and 36 cases(40.4%)of breast cancers, respectively, and the expression was higher than that of control group (P<0.01). The expression of Apelin was positively correlated with Snail (r=0.230, P<0.05). Apelin expression was associated with lymph node metastasis and TNM staging(P<0.05). Snail expression was associated with lymph node metastasis(P<0.05). Kaplan-Meier survival curve showed that the prognosis of Apelin positive group was worse than that of Apelin negative group (P<0.01). There was no significant difference in prognosis between Snail negative and positive groups (P>0.05). The prognosis of Apelin and Snail in both positive groups was worse than that of Apelin and Snail both negative groups (P<0.01). Multivariate COX regression analysis showed that Apelin and TNM staging could be used as independent prognostic factors for breast cancer (P<0.05). Conclusions: Apelin and Snail are highly expressed in breast cancer, and associated with lymph node metastasis and TNM stage. There is a positive correlation between Apelin and Snail expression, which may suggest a role in breast carcinogenesis. The prognosis of breast cancer with expression of Apelin and co-expression of Apelin and Snail is poor. Therefore, Apelin may be used as an effective indicator to evaluate the prognosis of breast cancer patients.


Assuntos
Neoplasias da Mama , Apelina , Mama , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Metástase Linfática , Estadiamento de Neoplasias , Prognóstico
2.
Nutr Metab Cardiovasc Dis ; 27(12): 1136-1142, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29170062

RESUMO

BACKGROUND AND AIMS: There are few studies on the association between HDL-C levels and arterial stiffness (AS). HDL-C levels vary in males and females, and it is not clear whether the relationship between HDL-C levels and AS is influenced by gender. The purpose of this study was to investigate gender differences in the association between HDL-C levels and AS in adults. METHODS AND RESULTS: After excluding subjects using lipid-lowering agent, 7254 subjects were enrolled. The AS was assessed by measuring the brachial-ankle pulse wave velocity (baPWV) value. The quartiles of HDL-C were <38, 38-45, 45-53 and >53 mg/dL in men and <48, 48-57, 57-69 and >68 mg/dL in women, respectively. In subjects aged <50 years, none of the HDL-C quartiles were associated with baPWV values. In subjects aged ≥50 years, the highest quartile of HDL-C (beta: -37.57, 95% CI: -61.61 to -13.54) was negatively related to baPWV values. When considering gender difference in subjects aged ≥50 years, the highest quartile of HDL-C (Q4 beta: -57.22, 95% CI: -95.63 to -18.81) was inversely associated with baPWV values in women, but none of the HDL-C quartiles were related to baPWV values in men. CONCLUSIONS: A high HDL-C level was associated with a lower risk of AS in subjects aged ≥50 years in women but not in men, although this relationship was not apparent in subjects aged <50 years. The association between HDL-C level and AS is thus influenced by gender in people aged ≥50 years.


Assuntos
Doenças Cardiovasculares/fisiopatologia , HDL-Colesterol/sangue , Dislipidemias/sangue , Rigidez Vascular , Adulto , Índice Tornozelo-Braço , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Estudos Transversais , Dislipidemias/diagnóstico , Dislipidemias/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Onda de Pulso , Fatores de Risco , Fatores Sexuais , Taiwan/epidemiologia , Regulação para Cima
3.
Zhonghua Bing Li Xue Za Zhi ; 46(5): 318-322, 2017 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-28468037

RESUMO

Objective: To investigate the clinicopathologic features of microcystic, elongated and fragmented (MELF) pattern invasion of endometrial adenocarcinoma. Methods: HE and immunohistochemistry staining method were used to analysis morphologic features and immunophenotype of 72 patients of endometrial adenocarcinoma with MELF pattern invasion, and chi-square test was used to analysis the clinicopathologic features. Results: The mean age of 72 patients was 54 years (40 to 70 years). Thirty-two patients were pre-menopausal and 40 were post-menopausal. According to the FIGO staging system (2014), 32 cases(44.4%)were at stage Ⅰ, 22 cases(30.6%)at stage Ⅱ, 17 cases(23.6%)at stage Ⅲ and 1 case(1.4%) at stage Ⅳ. Microscopically, MELF invasion showed microcystic, elongated slit-like or fragmented glands in myometrium and their lining cells usually were cube or flat, as well as the single or clusters of eosinophilic tumor cells mimicking histocytes. In addition, a fibromyxoid or inflammatory stromal response was often present.Immunohistochemical staining showed that MELF invasion was positive for p16, CA125 and CA19-9, but negative for ER, PR and p53.Compared with non-MELF pattern invasion, significant differences were noted in menopause pausimenia, FIGO stages, deep invasion into myometrium, lymph metastasis, lymphovascular space invasion (LVSL), serum CA125 and CA19-9 in patients with MELF pattern invasion (all P<0.05). Conclusions: MELF pattern invasion of endometrial adenocarcinoma is characterized by advanced FIGO stage, deep myoinvasion, high metastasis rate to lymph node and LVSL. Pathologists should recognize the MELF invasion and evaluate the depth of myometrium of infiltration and LVSL with special attention to the presence of MELF invasion with necessary immunohistochemistry for more accurate pathological diagnosis.


Assuntos
Adenocarcinoma/patologia , Neoplasias do Endométrio/patologia , Adenocarcinoma/sangue , Adenocarcinoma/química , Adenocarcinoma/ultraestrutura , Adulto , Idoso , Distribuição de Qui-Quadrado , Neoplasias do Endométrio/sangue , Neoplasias do Endométrio/química , Neoplasias do Endométrio/ultraestrutura , Feminino , Histiócitos/patologia , Humanos , Imuno-Histoquímica , Imunofenotipagem , Linfonodos , Metástase Linfática , Pessoa de Meia-Idade , Miométrio/química , Miométrio/patologia , Invasividade Neoplásica
5.
Br J Dermatol ; 170(4): 890-4, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24372057

RESUMO

BACKGROUND: The cingulate cortex is the main area in the brain involved in pruritus processing and is deactivated after scratching. Lichen simplex chronicus (LSC) is a common pruritic skin disorder characterized by skin lichenification following excessive scratching. Psychological factors may contribute to both the development and persistence of LSC. OBJECTIVES: To estimate the hazard ratio (HR) of LSC in people with anxiety disorders compared with the general population. METHODS: In this nationwide population-based retrospective cohort study we identified a total of 69 386 people, who formed the anxiety cohort, by using the Taiwan National Health Insurance Research Database from 2000 to 2009. The comparison cohort was composed of randomly selected people frequency matched for age (within 5-year intervals), sex and index date (the date of anxiety diagnosis) based on a 1 : 2 ratio. The risk of LSC was estimated as HRs and 95% confidence intervals (CIs) using the Cox proportional hazards model. RESULTS: After adjusting for age, sex and LSC-associated comorbidities, the people with anxiety had a 1·41-fold greater risk of developing LSC compared with the people in the comparison cohort (HR 1·41, 95% CI 1·30-1·52, P < 0·0001). In particular, individuals with obsessive-compulsive disorder had a significantly increased risk of developing LSC (HR 1·72, 95% CI 1·03-2·88, P = 0·0395). CONCLUSIONS: This study demonstrates that having an anxiety disorder is associated with an increased risk of LSC. Psychological factors were found to contribute to LSC. We recommend combining the management of LSC and psychological disorders to achieve favourable outcomes.


Assuntos
Transtornos de Ansiedade/complicações , Neurodermatite/psicologia , Adulto , Distribuição por Idade , Idoso , Transtornos de Ansiedade/epidemiologia , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurodermatite/epidemiologia , Distribuição por Sexo , Taiwan/epidemiologia
6.
Eur J Clin Microbiol Infect Dis ; 33(9): 1653-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24715153

RESUMO

Chronic fatigue syndrome (CFS) is a complex disorder accompanied by unexplainable persistent fatigue, in which several etiological factors exist, such as viral infections. Using the National Health Insurance Research Database (NHIRD) of Taiwan, this study evaluated the association between herpes zoster (HZ) infection and the risk of CFS, and examined the possibility of patients developing postviral fatigue effects, including the possibility of developing other unexplainable chronic fatigue conditions. In this prospective cohort study using the NHIRD, we identified 9,205 patients with HZ infection [ICD-9 (International Classification of Disease, Ninth Revision), code 053] and 36,820 patients without HZ infection (non-HZ) from 2005 to 2007, and followed up to the end of 2010. The incidence rate of CFS was higher in the HZ cohort than in the non-HZ cohort (4.56 vs. 3.44 per 1,000 person-years), with an adjusted hazard ratio of 1.29 [95 % confidence interval (CI) = 1.09-1.53]. It was shown that the risk of CFS without comorbidity for each patient increased from 1.25- to 1.36-fold between the CFS and non-CFS cohorts; with long-term follow-up, the HZ cohort showed a significantly higher cumulative incidence rate of developing CFS than the non-HZ patients. We propose that patients with chronic fatigue might exist in a subset of patients that would be associated with HZ infection. The actual mechanism of development of CFS that is attributed to HZ infection remains unclear. The findings of this population cohort study provide pivotal evidence of postviral fatigue among patients with HZ infection.


Assuntos
Síndrome de Fadiga Crônica/epidemiologia , Herpes Zoster/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Taiwan/epidemiologia , Adulto Jovem
8.
J Oral Rehabil ; 37(5): 346-51, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20113389

RESUMO

The survival rate of dental implants is markedly influenced by the quality of the bone into which they are placed. The purpose of this study was to determine the trabecular bone density at potential dental implant sites in different regions of the Chinese jawbone using computed tomography (CT) images. One hundred and fifty-four potential implant sites (15 in the anterior mandible, 47 in the anterior maxilla, 55 in the posterior mandible, and 37 in the posterior maxilla) were selected from the jawbones of 62 humans. The data were subjected to statistical analysis to determine any correlation between bone density (in Hounsfield units, HU) and jawbone region using the Kruskal-Wallis test. The bone densities in the four regions decreased in the following order: anterior mandible (530 +/- 161 HU, mean +/- s.d.) approximately equal anterior maxilla (516 +/- 132 HU) > posterior mandible (359 +/- 150 HU) approximately equal posterior maxilla (332 +/- 136 HU). The CT data demonstrate that trabecular bone density varies markedly with potential implant site in the anterior and posterior regions of the maxilla and mandible. These findings may provide the clinician with guidelines for dental implant surgical procedures (i.e., to determine whether a one-stage or a two-stage protocol is required).


Assuntos
Povo Asiático , Mandíbula/anatomia & histologia , Maxila/anatomia & histologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , China , Implantação Dentária Endóssea , Humanos , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X , Adulto Jovem
9.
10.
Microbiol Mol Biol Rev ; 64(4): 746-85, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11104818

RESUMO

Cellular differentiation, mating, and filamentous growth are regulated in many fungi by environmental and nutritional signals. For example, in response to nitrogen limitation, diploid cells of the yeast Saccharomyces cerevisiae undergo a dimorphic transition to filamentous growth referred to as pseudohyphal differentiation. Yeast filamentous growth is regulated, in part, by two conserved signal transduction cascades: a mitogen-activated protein kinase cascade and a G-protein regulated cyclic AMP signaling pathway. Related signaling cascades play an analogous role in regulating mating and virulence in the plant fungal pathogen Ustilago maydis and the human fungal pathogens Cryptococcus neoformans and Candida albicans. We review here studies on the signaling cascades that regulate development of these and other fungi. This analysis illustrates both how the model yeast S. cerevisiae can serve as a paradigm for signaling in other organisms and also how studies in other fungi provide insights into conserved signaling pathways that operate in many divergent organisms.


Assuntos
Fungos/patogenicidade , Calcineurina/metabolismo , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Fungos/citologia , Fungos/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Sistema de Sinalização das MAP Quinases , Feromônios , Receptor Cross-Talk , Fatores de Transcrição/metabolismo
11.
Nuklearmedizin ; 47(1): 48-55, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18278213

RESUMO

AIM: The retention index, a traditionally quantitative analysis of two-phase (201)Tl single photon emission computed tomography (SPECT) of the chest, is manually calculated by experienced physicians from comparable 2-D ROI. However, a 3-D ROI would provide more information than a 2-D ROI extracted from a single frame of SPECT. We propose a new diagnostic system, computer-aided diagnosis (CAD), to automatically detect suspicious lesions as 3-D objects on chest (201)Tl-SPECT, and assist the physician in interpreting these images. PATIENTS, METHODS: Seventy patients with thoracic lesions and confirmed diagnoses were enrolled to test this automatic CAD system. The reliability of the CAD system in detecting lesions as 3-D objects was compared to the 2-D ROI of (201)Tl-SPECT found by the manually visualized method. Furthermore, we also proposed a novel index, the retention index using the heart (RIH), to differentiate high retention (slow clearance, increasing target to heart ratio) as a criterion for a malignant lesion, from low retention (faster clearance, small or no increase of the target to heart ratio) for benign lesions. RESULTS: The CAD system can achieve a detection rate of 100% in automatically searching for thoracic lesions in (201)Tl-SPECT. In diagnostic performance, the CAD system with the RIH of comparable 3-D objects has an area under the ROC curve of 0.86, higher than the 0.78 of the traditional RI method (p=0.198). CONCLUSION: The CAD system of two-phase (201)Tl-SPECT is a promising tool for detecting and diagnosing thoracic lesions with a diagnostic accuracy of 0.81.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Infecções por Mycobacterium/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Tuberculose/diagnóstico por imagem , Adenocarcinoma/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma de Células Escamosas/diagnóstico por imagem , Diagnóstico por Computador , Feminino , Humanos , Pneumopatias/diagnóstico por imagem , Pneumopatias/microbiologia , Masculino , Pessoa de Meia-Idade , Radiografia Torácica , Radioisótopos
12.
Nat Commun ; 9(1): 1442, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29650960

RESUMO

Because the surface-to-volume ratio of quasi-two-dimensional materials is extremely high, understanding their surface characteristics is crucial for practically controlling their intrinsic properties and fabricating p-type and n-type layered semiconductors. Van der Waals crystals are expected to have an inert surface because of the absence of dangling bonds. However, here we show that the surface of high-quality synthesized molybdenum disulfide (MoS2) is a major n-doping source. The surface electron concentration of MoS2 is nearly four orders of magnitude higher than that of its inner bulk. Substantial thickness-dependent conductivity in MoS2 nanoflakes was observed. The transfer length method suggested the current transport in MoS2 following a two-dimensional behavior rather than the conventional three-dimensional mode. Scanning tunneling microscopy and angle-resolved photoemission spectroscopy measurements confirmed the presence of surface electron accumulation in this layered material. Notably, the in situ-cleaved surface exhibited a nearly intrinsic state without electron accumulation.

13.
Genetics ; 173(4): 1919-37, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16751665

RESUMO

In Saccharomyces cerevisiae, transcription of several drug transporter genes, including the major transporter gene PDR5, has been shown to peak during mitosis. The significance of this observation, however, remains unclear. PDR1 encodes the primary transcription activator of multiple drug transporter genes in S. cerevisiae, including PDR5. Here, we show that in synchronized PDR1 and pdr1-3 (multidrug resistant) strains, cellular efflux of a known substrate of ATP-binding-cassette transporters, doxorubicin (a fluorescent anticancer drug), is highest during mitosis when PDR5 transcription peaks. A genetic screen performed to identify regulators of multidrug resistance revealed that a truncation mutation in ELM1 (elm1-300) suppressed the multidrug resistance of pdr1-3. ELM1 encodes a serine/threonine protein kinase required for proper regulation of multiple cellular kinases, including those involved in mitosis, cytokinesis, and cellular morphogenesis. elm1-300 as well as elm1Delta mutations in a pdr1-3 strain also caused elongated bud morphology (indicating a G2/M delay) and reduction of PDR5 transcription under induced and noninduced conditions. Interestingly, mutations in several genes functionally related to ELM1, including cla4Delta, gin4Delta, and cdc28-C127Y, also caused drastic reductions in drug resistance and PDR5 transcription. Collectively, these data show that ELM1, and genes encoding related serine/threonine protein kinases, are required for regulation of multidrug resistance involving, at least in part, control of PDR5 transcription.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Sequência de Aminoácidos , Farmacorresistência Fúngica Múltipla/genética , Proteínas Quinases/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Deleção de Sequência , Transportadores de Cassetes de Ligação de ATP/biossíntese , Divisão Celular/genética , Fase G2/genética , Regulação Fúngica da Expressão Gênica/genética , Proteínas Quinases/metabolismo , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/biossíntese , Proteínas de Saccharomyces cerevisiae/metabolismo , Especificidade da Espécie , Transcrição Gênica
14.
Mol Cell Biol ; 14(4): 2298-306, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8139535

RESUMO

MOD5, a gene responsible for the modification of A37 to isopentenyl A37 of both cytosolic and mitochondrial tRNAs, encodes two isozymes. Initiation of translation at the first AUG of the MOD5 open reading frame generates delta 2-isopentenyl pyrophosphate:tRNA isopentanyl transferase I (IPPT-I), which is located predominantly, but not exclusively, in the mitochondria. Initiation of translation at a second AUG generates IPPT-II, which modifies cytoplasmic tRNA. IPPT-II is unable to target to mitochondria. The N-terminal sequence present in IPPT-I and absent in IPPT-II is therefore necessary for mitochondrial targeting. In these studies, we fused MOD5 sequences encoding N-terminal regions to genes encoding passenger proteins, pseudomature COXIV and dihydrofolate reductase, and studied the ability of these chimeric proteins to be imported into mitochondria both in vivo and in vitro. We found that the sequences necessary for mitochondrial import, amino acids 1 to 11, are not sufficient for efficient mitochondrial targeting and that at least some of the amino acids shared by IPPT-I and IPPT-II comprise part of the mitochondrial targeting information. We used indirect immunofluorescence and cell fractionation to locate the MOD5 isozymes in yeast. IPPT-I was found in two subcellular compartments: mitochondria and the cytosol. We also found that IPPT-II had two subcellular locations: nuclei and the cytosol. The nuclear location of this protein is surprising because the A37-->isopentenyl A37 modification had been predicted to occur in the cytoplasm. MOD5 is one of the first genes reported to encode isozymes found in three subcellular compartments.


Assuntos
Alquil e Aril Transferases , Núcleo Celular/enzimologia , Genes Fúngicos , Mitocôndrias/enzimologia , Biossíntese de Proteínas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/enzimologia , Transferases/biossíntese , Sequência de Aminoácidos , Sequência de Bases , Citosol/enzimologia , Isoenzimas/análise , Isoenzimas/biossíntese , Isoenzimas/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oligodesoxirribonucleotídeos , Fases de Leitura Aberta , Plasmídeos , Proteínas/análise , Proteínas/genética , Proteínas Recombinantes de Fusão/análise , Proteínas Recombinantes de Fusão/biossíntese , Saccharomyces cerevisiae/genética , Transcrição Gênica , Transferases/análise
15.
Genetics ; 171(3): 959-73, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16118188

RESUMO

TAF9 is a TATA-binding protein associated factor (TAF) conserved from yeast to humans and shared by two transcription coactivator complexes, TFIID and SAGA. The essentiality of the TAFs has made it difficult to ascertain their roles in TFIID and SAGA function. Here we performed a genomic synthetic genetic array analysis using a temperature-sensitive allele of TAF9 as a query. Results from this experiment showed that TAF9 interacts genetically with: (1) genes for multiple transcription factor complexes predominantly involving Mediator, chromatin modification/remodeling complexes, and regulators of transcription elongation; (2) virtually all nonessential genes encoding subunits of the SWR-C chromatin-remodeling complex and both TAF9 and SWR-C required for expressing the essential housekeeping gene RPS5; and (3) key genes for cell cycle control at the G1/S transition, as well as genes involved in cell polarity, cell integrity, and protein synthesis, suggesting a link between TAF9 function and cell growth control. We also showed that disruption of SAGA by deletion of SPT20 alters histone-DNA contacts and phosphorylated forms of RNA polymerase II at coding sequences. Our results raise the possibility of an unappreciated role for TAF9 in transcription elongation, perhaps in the context of SAGA, and provide further support for TAF9 involvement in cell cycle progression and growth control.


Assuntos
Alelos , Genoma Fúngico , Histona Acetiltransferases/fisiologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomyces cerevisiae/genética , Fatores Associados à Proteína de Ligação a TATA/genética , Fator de Transcrição TFIID/fisiologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Ciclo Celular/genética , Cromatina/metabolismo , Proteínas de Ligação a DNA/fisiologia , Análise em Microsséries , Proteínas Ribossômicas/biossíntese , Proteínas Ribossômicas/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/genética , Fator de Transcrição TFIID/metabolismo , Fatores de Transcrição/fisiologia , Transcrição Gênica/fisiologia
17.
Cancer Res ; 46(8): 3912-6, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2873883

RESUMO

Methotrexate (MTX) conjugates of a monoclonal antibody, anti-SSEA-1, containing an average of 45 mol MTX/mol of immunoglobulin M, were prepared by a carbodiimide coupling reaction. Binding experiments indicate that conjugation does not decrease the affinity of the antibody for its antigen. The conjugate strongly inhibits the growth of SSEA-1-bearing F-9 teratocarcinoma cells, with 50% inhibitory dose of 4.5 nM MTX, which makes it more active than free MTX (50% inhibitory dose of 15 nM). The drug-free antibody is not cytotoxic to F-9 cells at the concentrations used. The high efficacy of the conjugated drug may be due in part to the fact that anti-SSEA-1 antibody is an immunoglobulin M. MTX conjugated to nonspecific immunoglobulin M has little inhibitory effect (50% inhibitory dose of 150 nM). When acting on SSEA-1 negative cells, the two conjugates have only a small but identical effect. Thiamine pyrophosphate, an inhibitor of MTX transport, can prevent the cytotoxicity of the free MTX but not that of the anti-SSEA-1 conjugate. Leupeptin, an inhibitor of lysosomal protease, can partially protect F-9 cells against the antibody conjugate but not against free MTX. These results indicate that the MTX antibody conjugate binds specifically to F-9 cells, and is internalized and intracellularly degraded to release a small molecular active drug. Pretreatments of F-9 cells for 1 h with unlabeled antibody inhibits the subsequent uptake of identical concentration of labeled conjugate. The rate of internalization, however, regains almost normal values within 4 h, indicating a rapid reappearance of free antigenic sites at the cell surface.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Glicolipídeos/imunologia , Metotrexato/administração & dosagem , Teratoma/patologia , Animais , Imunoglobulina G/administração & dosagem , Leucovorina/farmacologia , Leupeptinas/farmacologia , Antígenos CD15 , Lisossomos/metabolismo , Metotrexato/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Teratoma/imunologia , Teratoma/terapia , Tiamina Pirofosfato/farmacologia , Trítio
18.
Biochim Biophys Acta ; 1034(1): 122-4, 1990 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-1691660

RESUMO

Histamine was coupled to poly(L-glutamate) (PLG) to give a copolymer, poly(glutamylhistamineglutamate) (PHG), with approx. 40% of carboxyl groups in PLG being modified. Unlike either poly(L-histidine) (PLH) or PLG, PHG precipitated only in buffers with pH between 4 and 5. A complex was formed between PHG and poly(L-lysine) (PLL) at pH 7, but it was rapidly dissociated at pH 5 or lower. When PHG-linked transferrin (Tf-PHG) was used to deliver a PLL-conjugated [3H]methotrexate ([3H]MTX-PLL) in K562 leukemia cell cultures, an intracellular accumulation of the radioactivity was observed. These results suggest that a copolymer with both imidazole and carboxyl groups can be useful in the design of acid-sensitive, carrier-mediated drug delivery systems.


Assuntos
Portadores de Fármacos , Histamina/administração & dosagem , Peptídeos/administração & dosagem , Ácido Poliglutâmico/administração & dosagem , Polilisina/administração & dosagem , Células Cultivadas , Concentração de Íons de Hidrogênio , Metotrexato/administração & dosagem , Metotrexato/farmacocinética , Transferrina/administração & dosagem
19.
Biochim Biophys Acta ; 801(1): 117-26, 1984 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-6087917

RESUMO

This paper characterizes the complex formed in vitro between polylysine and heparin in the presence of heparin excess, and investigates the interaction of this complex with the surface of Chinese hamster ovary cells. It examines the kinetics of surface binding and cellular uptake of the complex and shows that both processes can be distinguished from those of free heparin and free polylysine. The view that these three ligands bind to different surface sites is further supported by the fact that their interaction with cells is influenced differently by cell detachment with trypsin, detachment with EGTA or exposure to acid pH. Membrane transport of the complex is a saturable process suggestive of receptor-mediated endocytosis. It is, however, less effective than would be expected on the basis of the binding kinetics. Only 40% of the complex bound at 0 degrees C is internalized during a 2 h reincubation period at 37 degrees C, suggesting some degree of uncoupling between binding and endocytosis. These data confirm prior results obtained with methotrexate-polylysine conjugates. We had shown that the addition of heparin to a medium containing a methotrexate-polylysine conjugate leads unexpectedly to a marked cellular uptake of drug conjugate, which is capable of killing cells that are otherwise resistant to free methotrexate (Shen, W.-C. and Ryser, H.J.-P. (1981) Proc. Natl. Acad. Sci. USA 78, 7589-7593). The polylysine X heparin complex is therefore of interest as a potential carrier for intracellular drug delivery through endocytosis.


Assuntos
Heparina/metabolismo , Peptídeos/metabolismo , Polilisina/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Radioisótopos de Carbono , Linhagem Celular , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Feminino , Cinética , Ovário , Polilisina/toxicidade , Trítio
20.
Genetics ; 148(3): 1031-41, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9539422

RESUMO

The Aspergillus nidulans flbD gene encodes a protein with a Myb-like DNA-binding domain that is proposed to act in concert with other developmental regulators to control initiation of conidiophore development. We have identified a Neurospora crassa gene called rca-1 (regulator of conidiation in Aspergillus) based on its sequence similarity to flbD. We found that N. crassa rca-1 can complement the conidiation defect of an A. nidulans flbD mutant and that induced expression of rca-1 caused conidiation in submerged A. nidulans cultures just as was previously observed for overexpression of flbD. Thus, the N. crassa gene appears to be a functional homologue of A. nidulans flbD and this is the first demonstration of functional complementation of an A. nidulans sporulation defect using a gene from an evolutionarily distant fungus. However, deletion of the rca-1 gene in N. crassa had no major effect on growth rate, macroconidiation, microconidiation, or ascospore formation. The only phenotype displayed by the rca-1 mutant was straight or counterclockwise hyphal growth rather than the clockwise spiral growth observed for wild type. Thus, if rca-1 is involved in N. crassa development, its role is subtle or redundant.


Assuntos
Aspergillus nidulans/genética , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Genes Fúngicos , Neurospora crassa/genética , Transativadores/genética , Sequência de Aminoácidos , Aspergillus nidulans/fisiologia , Sequência de Bases , Clonagem Molecular , DNA Fúngico , Deleção de Genes , Teste de Complementação Genética , Dados de Sequência Molecular , Mutagênese , Neurospora crassa/crescimento & desenvolvimento , Homologia de Sequência de Aminoácidos , Esporos Fúngicos/genética
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