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1.
Mycorrhiza ; 31(2): 149-159, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33475799

RESUMO

The influence of mycorrhizal symbiosis on ecosystem processes depends on the mycorrhizal type and status of plants. Early research hypothesized that the proportion of arbuscular mycorrhizal (AM) species decreases and of ectomycorrhizal (ECM) and ericoid mycorrhizal (ERM) species increases along increasing elevations and latitudes. However, there is very scarce information about this pattern along elevation gradients. We aimed to test this hypothesis and to describe the trends in plant mycorrhizal status by examining the Pyrenean mountain range (from 400 to 3400 m asl). The distribution of plant mycorrhizal types: AM, ECM, ERM, and non-mycorrhizal (NM) and status (obligately, OM, or facultatively, FM mycorrhizal plants, FM) were identified based on the Pyrenean Floristic Atlas and analyzed for climatic and edaphic drivers. The proportion of AM plants decreased slightly with elevation, while ECM species peaked at 1000 m asl. The proportion of ERM and NM plant species rose with increasing elevation. The proportion of FM species increased, and OM species decreased with increasing elevation. The change of AM and ECM species, and OM and FM species, along the elevational gradient, corresponds broadly to changes along the latitudinal gradient, driven by a combination of climatic and edaphic factors. Differently, the elevational occurrence of NM plant species is mainly driven only by climatic factors (low temperature) and that of ERM species by only edaphic factors (low pH). Large-scale macroecological studies (≥ 50 km grid cell) well reflect the effects of climate on the distribution of plant mycorrhizal traits, but local data (≤ 1 km grid cell) are needed to understand the effects of soil conditions and land use.


Assuntos
Micorrizas , Ecossistema , Plantas , Solo , Simbiose
2.
Ann Rheum Dis ; 75(6): 1133-8, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26318385

RESUMO

OBJECTIVES: To evaluate the risk of opportunistic infections (OIs) in patients with rheumatoid arthritis (RA) treated with tofacitinib. METHODS: Phase II, III and long-term extension clinical trial data (April 2013 data-cut) from the tofacitinib RA programme were reviewed. OIs defined a priori included mycobacterial and fungal infections, multidermatomal herpes zoster and other viral infections associated with immunosuppression. For OIs, we calculated crude incidence rates (IRs; per 100 patient-years (95% CI)); for tuberculosis (TB) specifically, we calculated rates stratified by patient enrolment region according to background TB IR (per 100 patient-years): low (≤0.01), medium (>0.01 to ≤0.05) and high (>0.05). RESULTS: We identified 60 OIs among 5671 subjects; all occurred among tofacitinib-treated patients. TB (crude IR 0.21, 95% CI of (0.14 to 0.30)) was the most common OI (n=26); median time between drug start and diagnosis was 64 weeks (range 15-161 weeks). Twenty-one cases (81%) occurred in countries with high background TB IR, and the rate varied with regional background TB IR: low 0.02 (0.003 to 0.15), medium 0.08 (0.03 to 0.21) and high 0.75 (0.49 to 1.15). In Phase III studies, 263 patients diagnosed with latent TB infection were treated with isoniazid and tofacitinib concurrently; none developed TB. For OIs other than TB, 34 events were reported (crude IR 0.25 (95% CI 0.18 to 0.36)). CONCLUSIONS: Within the global tofacitinib RA development programme, TB was the most common OI reported but was rare in regions of low and medium TB incidence. Patients who screen positive for latent TB can be treated with isoniazid during tofacitinib therapy.


Assuntos
Antirreumáticos/efeitos adversos , Artrite Reumatoide/tratamento farmacológico , Infecções Oportunistas/induzido quimicamente , Piperidinas/efeitos adversos , Pirimidinas/efeitos adversos , Pirróis/efeitos adversos , Tuberculose/induzido quimicamente , Antirreumáticos/uso terapêutico , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/imunologia , Ensaios Clínicos como Assunto , Humanos , Hospedeiro Imunocomprometido , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Incidência , Janus Quinase 3/antagonistas & inibidores , Infecções Oportunistas/epidemiologia , Infecções Oportunistas/imunologia , Piperidinas/uso terapêutico , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Medição de Risco , Tuberculose/epidemiologia , Tuberculose/imunologia
3.
Nat Genet ; 9(2): 152-9, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7719342

RESUMO

We have examined data on six closely linked microsatellite loci on chromosome 9q34 from 59 Ashkenazi Jewish families with idiopathic torsion dystonia (ITD). Our data show that the vast majority (> 90%) of early-onset ITD cases in the Ashkenazi population are due to a single founder mutation, which we estimate first appeared approximately 350 years ago. We also show that carriers preferentially originate from the northern part of the historic Jewish Pale of settlement (Lithuania and Byelorussia). The recent origin of this dominant mutation and its current high frequency (between 1/6,000 and 1/2,000) suggest that the Ashkenazi population descends from a limited group of founders, and emphasize the importance of genetic drift in determining disease allele frequencies in this population.


Assuntos
Distonia Muscular Deformante/epidemiologia , Distonia Muscular Deformante/genética , Judeus/história , Judeus/estatística & dados numéricos , Alelos , Mapeamento Cromossômico , Cromossomos Humanos Par 9 , Distonia Muscular Deformante/etiologia , Europa (Continente)/epidemiologia , Frequência do Gene , Marcadores Genéticos , Genética Populacional , História do Século XVII , Humanos , Mutação , Linhagem , Tempo
4.
Nat Genet ; 17(1): 40-8, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9288096

RESUMO

Early-onset torsion dystonia is a movement disorder, characterized by twisting muscle contractures, that begins in childhood. Symptoms are believed to result from altered neuronal communication in the basal ganglia. This study identifies the DYT1 gene on human chromosome 9q34 as being responsible for this dominant disease. Almost all cases of early-onset dystonia have a unique 3-bp deletion that appears to have arisen idependently in different ethnic populations. This deletion results in loss of one of a pair of glutamic-acid residues in a conserved region of a novel ATP-binding protein, termed torsinA. This protein has homologues in nematode, rat, mouse and humans, with some resemblance to the family of heat-shock proteins and Clp proteases.


Assuntos
Cromossomos Humanos Par 9 , Distonia Muscular Deformante/genética , Chaperonas Moleculares , Transportadores de Cassetes de Ligação de ATP/genética , Idade de Início , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas de Transporte/química , Mapeamento Cromossômico , Análise Mutacional de DNA , Triagem de Portadores Genéticos , Ligação Genética , Marcadores Genéticos , Humanos , Judeus/genética , Linfócitos , Camundongos , Dados de Sequência Molecular , Mutação Puntual , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Ratos , Proteínas Recombinantes/biossíntese , Alinhamento de Sequência , Deleção de Sequência , Homologia de Sequência de Aminoácidos , Transcrição Gênica
5.
Reumatol Clin (Engl Ed) ; 19(6): 319-327, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37286268

RESUMO

OBJECTIVE: To describe efficacy, safety, and patient-reported outcomes (PROs) in patients with rheumatoid arthritis (RA) with an inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) treated with tofacitinib or biological DMARDs (bDMARDs) in real-life conditions. METHODS: A noninterventional study was performed between March 2017 and September 2019 at 13 sites in Colombia and Peru. Outcomes measured at baseline and at the 6-month follow-up were disease activity (RAPID3 [Routine Assessment of Patients Index Data] score), functional status (HAQ-DI [Health Assessment Questionnaire] score), and quality of life (EQ-5D-3L [EuroQol Questionnaire]). The Disease Activity Score-28 (DAS28-ESR) and frequency of adverse events (AEs) were also reported. Unadjusted and adjusted differences from baseline were estimated and expressed as the least squares mean difference (LSMD). RESULTS: Data from 100 patients treated with tofacitinib and 70 patients with bDMARDs were collected. At baseline, the patients' mean age was 53.53 years (SD 13.77), the mean disease duration was 6.31 years (SD 7.01). The change from baseline at month 6 was not statistically significant different in the adjusted LSMD [SD] for tofacitinib vs. bDMARDs for RAPID3 score (-2.55[.30] vs. -2.52[.26]), HAQ-DI score (-.56[.07] vs. -.50[.08]), EQ-5D-3L score (.39[.04] vs. .37[.04]) and DAS28-ESR (-2.37[.22] vs. -2.77[.20]). Patients from both groups presented similar proportions of nonserious and serious AEs. No deaths were reported. CONCLUSION: Changes from baseline were not statistically significantly different between tofacitinib and bDMARDs in terms of RAPID3 scores and secondary outcomes. Patients from both groups presented similar proportions of nonserious and serious AEs. CLINICAL TRIAL NUMBER: NCT03073109.


Assuntos
Antirreumáticos , Artrite Reumatoide , Humanos , Pessoa de Meia-Idade , Qualidade de Vida , América Latina , Resultado do Tratamento , Pirróis/uso terapêutico , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Medidas de Resultados Relatados pelo Paciente
6.
Expert Rev Pharmacoecon Outcomes Res ; 22(5): 787-794, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35249439

RESUMO

OBJECTIVE: To evaluate work productivity of adult Latin American patients with rheumatoid arthritis (RA) treated with tofacitinib and biological disease-modifying anti-rheumatic drugs (bDMARDs) measured by the Work Productivity and Activity Impairment (WPAI) in RA questionnaire at 0- and 6-month follow-up. METHODS: This non-interventional study was performed in Colombia and Peru. Evaluated the effects of tofacitinib and bDMARDs in patients with RA after failure of conventional DMARDs. The WPAI-RA questionnaire was administered at baseline and at the 6-month (±1 month) follow-up. The results are expressed as least squares means (LSMs), and standard errors (SEs). RESULTS: One hundred patients treated with tofacitinib and 70 patients treated with bDMARDs were recruited. Twenty-eight percent of patients from the tofacitinib group and 40.0% from the bDMARDs group were working for pay at baseline. At month 6, the changes in absenteeism, presenteeism, and work impairment due to health were -18.3% (SE 7.7), -34.8% (SE 5.9), and -11.0% (SE 16.5), respectively, in the tofacitinib group and -19.4% (SE 8.0), -34.8% (SE 6.2), and -15.9% (SE 15.0), for the bDMARD group. CONCLUSION: For patients who reported working, there were improvements in presenteeism, absenteeism, and work impairment due to health in both groups. TRIAL REGISTRATION: NCT03073109.


Assuntos
Antirreumáticos , Artrite Reumatoide , Adulto , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Eficiência , Humanos , América Latina , Piperidinas/uso terapêutico , Pirimidinas/uso terapêutico , Pirróis/efeitos adversos , Resultado do Tratamento , Desempenho Profissional
7.
Growth Factors ; 29(2-3): 82-93, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21410323

RESUMO

The estrogen receptor (ER) is a primary target for breast cancer (BC) treatment. As BC progresses to estrogen-independent growth, the insulin-like growth factor-1 receptor (IGF-1R) and the ER interact in synergistic cross-talk mechanisms, which result in enhanced activation of both receptors' signaling cascades. Insulin-like growth factor-2 (IGF-2) is critical in BC progression and its actions are mediated by the IGF-1R. Our previous studies showed that IGF-2 regulates survival genes that protect the mitochondria and promote chemoresistance. In this study, we analyzed BC cells by subcellular fractionation, Western-Blot, qRT-PCR, and siRNA analysis. Our results demonstrate that IGF-2 activates ER-α and ER-ß, and modulates their translocation to the nucleus, membrane organelles, and the mitochondria. IGF-2 actions are mediated by the IGF-1R and the insulin receptor. This novel mechanism of IGF-2 synergistic cross-talk signaling with ER-α and ER-ß can promote estrogen-independent BC progression and provide new therapeutic targets for the treatment of BC patients.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Receptor de Insulina/metabolismo , Idoso , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Feminino , Humanos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Transdução de Sinais , Transcrição Gênica
8.
Growth Factors ; 29(6): 278-89, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21913804

RESUMO

We showed that when insulin-like growth factor II (IGF-II) is highly expressed in breast tissues and cell lines, the IGF-I receptor signaling pathway is highly activated. Since IGF-II activates the insulin receptor (INSR), we propose that the INSR signaling is also activated in this system. We examined the expression of both INSR isoforms, insulin receptor A (INSR-A) and insulin receptor B (INSR-B), and the downstream signaling pathways in breast cancer (BC) cells and in paired (normal/tumor) breast tissues from 100 patients. Analysis was performed by real-time PCR, Western blot, immunohistochemistry, and phospho-ELISA techniques. Tumor tissues and cell lines from African-American patients expressed higher levels of INSR-A, but lower levels of INSR-B. Accordingly, insulin receptor substrate 1 and focal adhesion kinase activation were significantly increased in these women. We conclude that higher INSR-A and lower INSR-B contribute to higher proliferation and lower metabolic response. Thus, differential expression of INSR isoforms represents a potential biological link between BC and diabetes.


Assuntos
Antígenos CD/metabolismo , Neoplasias da Mama/metabolismo , Diabetes Mellitus/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Receptor de Insulina/metabolismo , Transdução de Sinais , Negro ou Afro-Americano , Antígenos CD/biossíntese , Antígenos CD/genética , Mama/metabolismo , Feminino , Proteína-Tirosina Quinases de Adesão Focal/biossíntese , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like II/genética , Fosforilação , Isoformas de Proteínas/metabolismo , Receptor de Insulina/biossíntese , Receptor de Insulina/genética , Células Tumorais Cultivadas , População Branca
9.
Educ Health (Abingdon) ; 22(2): 274, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20029751

RESUMO

CONTEXT: Women's health is an often neglected component of health professions education despite the well-documented need to improve the health status of women, especially in low income countries. This paper was written on behalf of all members of The Network: Towards Unity for Health Women and Health Taskforce (WHTF) which unites leaders in women's health and higher education from different countries around the world. The WHTF objectives include teaching health providers the skills and knowledge necessary to improve care to women; encouraging universities to partner with community women's groups; promoting the inclusion of women's rights and gender issues in curricula; and cultivating leadership among female health professions students. OBJECTIVE/CONTENT: The main goal of the paper is to provide an overview of the collaborative processes, the accomplishments and the lessons learned in this project since the early 1990s. It includes the history and evolution of the Taskforce; the importance of human rights and gender issues in approaching women's health; teaching tools--the Women and Health Learning Package (WHLP); implementation of WHLP in health professions education and community settings; and main outcomes and future challenges. The WHLP was implemented in fourteen universities and seven university community programs. A new edition of WHLP will be available in 2009. CONCLUSION: The WHTF is a model of south-south collaboration in health professions education and community programs to improve women's health. It has been successful in reaching universities and communities all over the globe and provides a model for other education, health and community issues.


Assuntos
Comitês Consultivos , Redes Comunitárias , Pessoal de Saúde/educação , Cooperação Internacional , Saúde da Mulher , Currículo , Feminino , Processos Grupais , Humanos , Desenvolvimento de Programas , Direitos da Mulher
10.
Neuron ; 2(5): 1427-34, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2576373

RESUMO

Torsion dystonia is a movement disorder of unknown etiology characterized by loss of control of voluntary movements appearing as sustained muscle contractions and/or abnormal postures. Dystonic movements can be caused by lesions in the basal ganglia, drugs, or gene defects. Several hereditary forms have been described, most of which have autosomal dominant transmission with variable expressivity. In the Ashkenazi Jewish population the defective gene frequency is about 1/10,000. Here, linkage analysis using polymorphic DNA and protein markers has been used to locate a gene responsible for susceptibility to dystonia in a large, non-Jewish kinship. Affected members of this family have a clinical syndrome similar to that found in the Jewish population. This dystonia gene (ITD1) shows tight linkage with the gene encoding gelsolin, an actin binding protein, and appears by multipoint linkage analysis to lie in the q32-q34 region of chromosome 9 between ABO and D9S26, a region that also contains the locus for dopamine-beta-hydroxylase.


Assuntos
Cromossomos Humanos Par 9 , Distonia Muscular Deformante/genética , Polimorfismo de Fragmento de Restrição , Proteínas de Ligação ao Cálcio/genética , Mapeamento Cromossômico , Sondas de DNA , Dopamina beta-Hidroxilase/genética , Gelsolina , Ligação Genética , Marcadores Genéticos , Humanos , Proteínas dos Microfilamentos/genética , Linhagem
11.
J Cytol ; 35(3): 143-148, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30089942

RESUMO

INTRODUCTION: Cervicouterine cancer (CC) is a health problem worldwide and is the fourth most common cancer in women, with a greater proportion of individuals affected by advanced stages of the disease in developing countries. OBJECTIVE: To determine the sensitivity and specificity of the TruScreen™ opto-electronic device vs. conventional cytology in CC screenings. METHODOLOGY: This is a prospective observational study that included individuals who presented for the first time at the Dysplasia Clinic of the Instituto Nacional de Cancerología from March 1 through April 30, 2016, and those referred due to abnormal conventional cytology. The patients were evaluated with the TruScreen™ device, conventional cytology, colposcopy and, if necessary, cervical biopsy. The results were analyzed by descriptive statistics as well as the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the TruScreen™, using conventional cytology as the standard. RESULTS: Thirty-two patients were included who met the inclusion criteria. The average age of the patients was 40 years (range, 23-61 years). For the diagnosis of high-grade intraepithelial lesions, the TruScreen™ device showed a 43% sensitivity, a 92% specificity, a PPV of 60%, and a NPV of 85%, whereas evaluation via cervical biopsy exhibited a 33% sensitivity, an 86% specificity, a 33% PPV, and an 86% NPV. The Kappa agreement index of the TruScreen™ with the colposcopies was 0.70. CONCLUSIONS: TruScreen™ demonstrated low sensitivity and high specificity compared with conventional cytology, which had a high NPV.

14.
Plant Dis ; 90(8): 1004-1011, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30781291

RESUMO

We report the results of a survey for the presence of Papaya ringspot virus (PRSV) along the coasts of the Gulf of Mexico and the Pacific Ocean, in 15 federal states of Mexico that account for over 98% of the national papaya production. More than 80 locations were visited in 58 counties. Out of a total of 267 papaya leaf samples, 157 tested positive for PRSV. We tested for the presence of three other viruses because of the occurrence of severe, atypical symptoms in plantations. Only Papaya mosaic virus (PapMV) was detected. PRSV was present in every county. PapMV was less frequent, but its overall distribution was almost identical. PRSV and PapMV occurred in single or mixed infections of papaya and other host species that could function as virus reservoirs. We investigated the diversity of the coat protein (CP) sequences of 36 PRSV isolates. The amino acid sequence divergence among all isolates ranged from 0.4 to 9.9%, and was comparable to that found in other regions of the world. In contrast to most of these world regions, there is a clear correlation between CP sequence variation and the geographical origins of the virus isolates.

15.
Mol Endocrinol ; 3(3): 567-74, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2473392

RESUMO

The insulin-like growth factor binding proteins (IGF-BPs) are structurally and immunologically distinct from the IGF type 1 or type 2 receptors and are characterized by two major forms: a large, GH-dependent BP found in human plasma (Mr = 150 k) and a small GH-independent BP (Mr = 28-42 k) present in human plasma, amniotic fluid, and HEP G2 cells. Using affinity cross-linking techniques, we have identified several binding proteins secreted by human breast cancer cell lines (Hs578T, MDA-231, T-47D, and MCF-7). Under nonreducing conditions these proteins migrated at an apparent Mr = 35, 28, 27, and 24 k, while reducing conditions revealed bands of apparent Mr = 35, 32, 27, and 24 k. Competitive binding studies in T-47D-conditioned media demonstrated that these BPs bound more IGF-II than IGF-I, and that IGF-II potently inhibited binding of either IGF-I or -II. Immunological studies using a polyclonal antibody against the HEP G2 small BP revealed no immunoreactive BP in conditioned media from MCF-7 and T-47D and only slight immunoreactivity in conditioned media from Hs578T and MDA 231. Analysis by Northern blot, using a probe from the cDNA sequence of the HEP G2 BP, demonstrated that Hs578T and MDA-231 cell lines contained small amounts of the 1.65 kilobase mRNA characteristic of the HEP G2 BP, while MCF-7 and T-47D tested negative.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Transporte/isolamento & purificação , Northern Blotting , Western Blotting , Eletroforese em Gel de Poliacrilamida , Humanos , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo
16.
Endocrinology ; 138(5): 2199-202, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9112420

RESUMO

A chemiluminescent dot blot assay has been developed by our laboratory for rapid determinations of IGF-I in serum-free conditioned media (CM) collected from cultured cells. In contrast to IGF-I radioimmunoassays (RIAs), the IGF binding proteins (IGFBPs) did not interfere with the dot blot assay and did not require the laborious (and sometimes ineffective) removal of IGFBPs. Although all six IGFBPs were shown to bind to 125I IGF-I, none interfered with IGF-I detection on nitrocellulose dot blots. In contrast, an RIA using the same Oncogene monoclonal antibody (clone 82-9A) showed interference by IGFBP-1, IGFBP-2, and IGFBP-4. The IGF-I dot blot assay was sensitive (0.125-8.0 ng IGF-I), specific (assay crossreactivity with IGF-II is less than 1%), and reproducible (intra-assay variance < or = 6%; inter-assay variance < 12%) when chemiluminescence was quantified by phosphorimager and Molecular Analyst software (BioRad). The apparent sensitivity of the enhanced chemiluminescence (ECL) reagent to serum, precludes the use of this assay for IGF-I determination in serum or in serum-containing media.


Assuntos
Meios de Cultivo Condicionados/química , Técnicas de Imunoadsorção , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina , Fator de Crescimento Insulin-Like I/análise , Medições Luminescentes , Anticorpos Monoclonais , Western Blotting , Humanos , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/análise , Controle de Qualidade , Proteínas Recombinantes/análise , Sensibilidade e Especificidade
17.
Endocrinology ; 134(4): 1960-3, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7511096

RESUMO

A dot blot method for the detection of picogram quantities of human and rat insulin-like growth factor II (IGF-II) in serum-free conditioned media is described. The crossreactivity of human recombinant IGF-I in the assay was < 10%. None of the IGF binding proteins (IGFBP 1-6) diminished the IGF-II signal. In contrast, significant interference by the IGFBPs was observed when the same concentrations of IGFBPs and 125I-IGF-II were used in a radioimmunoassay which utilized the same antibody. Why IGF-II is detected in the dot blot assay without IGFBP interference is not understood. We speculate that the conformation of the IGF-II/binding protein complex may be altered by binding to the nitrocellulose, exposing the IGF-II epitope that is recognized by the antibody. IGF-II was detected in 1 microliter of serum-free conditioned media from BRL 3A cells (which secrete IGF-II) while no signal was generated by 50 microliters of BRL 3A2 conditioned media (which do not secrete IGF-II). In summary, this method is ideal for screening cells in serum free-culture for production of IGF-II without the need for separation of IGF-II from cell derived IGFBPs.


Assuntos
Proteínas de Transporte/metabolismo , Fator de Crescimento Insulin-Like II/análise , Animais , Artefatos , Autorradiografia , Meios de Cultura Livres de Soro , Humanos , Immunoblotting , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina , Medições Luminescentes , Radioimunoensaio , Ratos , Proteínas Recombinantes , Somatomedinas/metabolismo
18.
Endocrinology ; 137(5): 1851-9, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8612524

RESUMO

A previous observation that insulin-like growth factor II (IGF-II) inhibits the cellular uptake of a lysosomal enzyme by inhibiting binding to the IGF-II/mannose 6-phosphate receptor led to the proposal that, in a cell producing IGF-II, the routing of lysosomal enzymes might be altered. To test this hypothesis MCF-7 breast cancer cells were transfected with pRc/CMV vector only (CMV) or vector containing IGF-II complementary DNA encoding either mature (M-II) or precursor (P-II) IGF-II, and the routing of cathepsin D, a predominant lysosomal enzyme in this cell line, was examined. The concentration of IGF-II in media conditioned by P-II clones (11.2 +/- 4.3 micrograms/ml) was much higher than in media conditioned by M-II clones (1.3 +/- 1.5 micrograms/ml). Metabolic labeling experiments were performed with 10 mM mannose 6-phosphate present in the medium to block reuptake of lysosomal enzymes. Cell extracts (C) and media (M) were immuno-precipitated with a cathepsin D antiserum, and immunoprecipitates were analyzed by SDS-PAGE. The mean of the C/M ratio of cathepsin D for the seven P-II clones (1.60 +/- 0.13) was significantly lower than for the six CMV clones (3.47 +/- 0.48). Similar results were obtained when conditioned M and C were examined by immunoblotting after a 48-h incubation. The mean of the C/M ratio for the seven P-II clones (11.4 +/- 1.6) was significantly lower than for the six CMV clones (24.9 +/- 5.2). There was also a strong negative correlation between the ratio of intracellular cathepsin D to extracellular cathepsin D and relative cathepsin D synthesis (r = 0.843), consistent with increased cathepsin D production in cells overexpressing IGF-II. It is concluded that endogenous IGF-II modulates the routing of cathepsin D in MCF-7 cells.


Assuntos
Neoplasias da Mama/metabolismo , Catepsina D/metabolismo , Fator de Crescimento Insulin-Like II/farmacologia , Catepsina D/biossíntese , Meios de Cultivo Condicionados , DNA Complementar/genética , Humanos , Técnicas de Imunoadsorção , Fator de Crescimento Insulin-Like II/genética , Fator de Crescimento Insulin-Like II/metabolismo , Lisossomos/enzimologia , Receptor IGF Tipo 2/metabolismo , Transfecção , Células Tumorais Cultivadas
19.
J Clin Endocrinol Metab ; 80(1): 104-10, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7530254

RESUMO

Insulin-like growth factor-binding protein-4 (IGFBP-4) is an important regulator of insulin-like growth factor-I (IGF-I) anabolic activity in bone. Although cultured human osteoblast-like (hOB) cells have been reported to secrete IGFBP-4, we could not detect IGFBP-4 protein in 8 of 27 individual donor-derived hOB-cell conditioned medium (hOB-CM) samples examined by Western ligand blotting. Nonetheless, this subset of hOB cells had normal IGFBP-4 messenger ribonucleic acid expression and protein secretion. Regulation of IGFBP-4 levels in hOB cultures appeared to occur extracellularly. hOB cells produce an IGFBP-4 proteinase that requires the presence of IGF for cleavage of the IGFBP-4 molecule into 2 fragments of approximately 18 and 14 kilodaltons. These fragments are not detected by Western ligand blotting. Our data indicate that elevated endogenous levels of IGF can activate IGFBP-4 proteolysis, because in hOB cultures lacking detectable IGFBP-4 protein 1) basal IGF messenger ribonucleic acid expression was increased; 2) IGF-II peptide levels were elevated; 3) IGF-neutralizing antibodies added to hOB-CM attenuated the proteolysis of exogenous IGFBP-4; and 4) recombinant human IGFBP-4 was proteolyzed into 2 immunoreactive fragments of approximately 18 and 14 kilodaltons during cell-free incubations in these hOB-CM without the addition of exogenous IGF. In conclusion, elevated IGF expression and secretion can contribute to enhanced proteolysis of endogenous and exogenous IGFBP-4 via a proteinase secreted by cultured hOB cells. Levels of endogenous IGF peptide may determine IGFBP-4 availability in the bone microenvironment and, thus, modulate the local cell response to IGF-I.


Assuntos
Proteínas de Transporte/metabolismo , Osteoblastos/metabolismo , Somatomedinas/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Disponibilidade Biológica , Células Cultivadas , Feminino , Expressão Gênica , Humanos , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina , Masculino , Pessoa de Meia-Idade , Peptídeo Hidrolases/metabolismo , RNA Mensageiro/metabolismo , Valores de Referência , Somatomedinas/genética
20.
J Clin Endocrinol Metab ; 71(2): 530-2, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1696278

RESUMO

Human breast cancer cells (HBCC) secrete at least four different forms of IGFBPs. We have previously demonstrated that hIGFBP-1 is a minor component of IGFBPs secreted by Hs578T cells and is absent in CM from MCF-7 cells. In our present report, we describe the immunological and structural relationship of HBCC IGFBPs to hIGFBP-2 and hIGFBP-3. Analysis of conditioned media (CM) from Hs578T by Western ligand blotting revealed three IGFBPs of apparent Mr = 38K, 28K, and 24K; CM from MCF-7 revealed only two IGFBPs, of apparent Mr = 31K and 24K. Immunoprecipitation studies with polyclonal antibodies raised against hIGFBP-2 and hIGFBP-3 demonstrated that the 38K IGFBP in Hs578T CM is immunologically related to hIGFBP-3, while the 31K IGFBP in MCF-7 cells is related to the hIGFBP-2. Analysis by Northern blot demonstrated that MCF-7 cells contained mRNA for hIGFBP-2, while Hs578T cells contained the mRNA characteristic of the hIGFBP-3. The identity of the 24K IGFBP remains unknown, and may represent a distinct IGFBP. Of note, assay of CM following removal of BPs by acid chromatography demonstrated no detectable IGF-I or -II. The role of these IGFBPs in HBCC is of interest in view of the potential modulation of IGF actions by these proteins.


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Transporte/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Somatomedinas/metabolismo , Células Tumorais Cultivadas/metabolismo , Western Blotting , Proteínas de Transporte/análise , Proteínas de Transporte/genética , Proteínas de Transporte/isolamento & purificação , Linhagem Celular , Feminino , Humanos , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina , RNA Neoplásico/isolamento & purificação , Proteínas Recombinantes/metabolismo
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