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1.
Clin Exp Dermatol ; 36(6): 579-83; quiz 583-4, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21671991

RESUMO

This is a report of a study day held in London on 3 March 2010 to discuss measures with which to meet the nutritional requirements of patients with epidermolysis bullosa (EB). Members of national and international multidisciplinary teams (MDTs) caring for patients with EB attended this event. The study day focused on four challenging aspects of management intimately associated with nutritional status in EB, necessitating close cooperation between MDT members: iron-deficiency anaemia, gastrostomy placement and feeding, muscle mass and mobility, and dental health. The study day provided a unique forum for dietitians, doctors, nurses, physiotherapists, psychologists, psychotherapists, dentists, dental hygienists and occupational therapists to share knowledge and debate problems common to all who strive to promote best practice in this rare and complex group of conditions.


Assuntos
Epidermólise Bolhosa/dietoterapia , Apoio Nutricional/métodos , Adolescente , Adulto , Anemia Ferropriva/prevenção & controle , Criança , Prestação Integrada de Cuidados de Saúde/organização & administração , Serviços de Saúde Bucal , Epidermólise Bolhosa/complicações , Epidermólise Bolhosa/fisiopatologia , Exercício Físico , Feminino , Gastrostomia/métodos , Humanos , Comunicação Interdisciplinar , Masculino , Necessidades Nutricionais , Estado Nutricional , Adulto Jovem
2.
Science ; 239(4840): 645-7, 1988 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-3277276

RESUMO

Identification of genes that function to protect cells from radiation damage is an essential step in understanding the molecular mechanisms by which mammalian cells cope with ionizing radiation. The intrinsic radiation resistance (D0) of NIH 3T3 cells was markedly and significantly increased by transformation with ras oncogenes activated by missense mutations. This radiobiologic activity appeared to be a specific consequence of the ras mutations rather than of transformation, since revertant cells that contained functional ras genes (but were no longer phenotypically transformed) retained their increased D0's.


Assuntos
Sobrevivência Celular/efeitos da radiação , Genes ras , Animais , Transformação Celular Neoplásica , Células Cultivadas , Células Clonais , Relação Dose-Resposta à Radiação , Camundongos , Camundongos Endogâmicos
3.
Science ; 182(4112): 592-4, 1973 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-4355680

RESUMO

Strain BALB/c mice were injected intraperitoneally with 0.5 milliliter of pristane, and 39 to 56 days later they were infected with Abelson murine leukemia virus, which is a lymphosarcomagenic variant of Moloney virus. Fifty-eight percent of the mice developed lymphosarcoma, and 28 percent developed immunoglobulin-producing plasmacytomas within 20 to 93 days (77 to 149 days after the pristane injection). Two of 57 control mice developed plasmacytomas at days 138 and 166 after a single injection of pristane; no plasmacytomas were found in mice treated with virus alone.


Assuntos
Alcanos , Carcinógenos , Vírus da Leucemia Murina , Plasmocitoma/etiologia , Animais , Eletroforese em Gel de Amido , Imunoglobulina A/isolamento & purificação , Fragmentos de Imunoglobulinas/isolamento & purificação , Imunoglobulinas/isolamento & purificação , Linfoma não Hodgkin/induzido quimicamente , Linfoma não Hodgkin/etiologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas do Mieloma/isolamento & purificação , Plasmocitoma/induzido quimicamente , Plasmocitoma/imunologia , Fatores de Tempo
4.
Sex Transm Infect ; 84(4): 306-11, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18385223

RESUMO

OBJECTIVE: To investigate self-administered vaginal swabs for assessing prevalence and correlates of carcinogenic human papillomavirus (HPV) infection in rural Rakai, Uganda. METHODS: 1003 sexually experienced women enrolled in a community cohort provided self-administered vaginal swabs collected at annual, home-based surveys. Carcinogenic HPV prevalence, adjusted odds ratios (AOR), 95% confidence intervals (CI) and associated risk factors were determined. RESULTS: Carcinogenic HPV prevalence was 19.2%: 46.6% among HIV positive and 14.8% among HIV negative women (p<0.001). Type-specific prevalence ranged from 2.0% (HPV 16 and 52) to 0.2% (HPV 31). Age-specific HPV prevalence decreased significantly (p<0.001) among HIV negative women; however, the decrease among HIV positive women was not as pronounced (p = 0.1). Factors independently associated with carcinogenic HPV infection were HIV (AOR 4.82, CI 3.10 to 7.53), age (AOR 4.97, 95% CI 2.19 to 11.26 for 15-19 year olds compared to 40+ years), more than two sex partners in the past year (AOR 2.21, CI 1.10 to 4.43) and self-reported herpes zoster, candidiasis or tuberculosis (AOR 4.52, CI 1.01 to 20.31). Married women were less likely to have prevalent carcinogenic HPV (AOR 0.46, CI 0.30 to 0.70). CONCLUSIONS: HPV prevalence and correlates measured using self-administered vaginal swabs were similar to studies that use cervical samples. Thus, self-collection can be used as a substitute for cervical specimens and provide an important tool for research in populations unwilling to undergo pelvic exam.


Assuntos
Infecções por Papillomavirus/epidemiologia , Adolescente , Adulto , DNA Viral/análise , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Prevalência , Fatores de Risco , Saúde da População Rural , Infecções Tumorais por Vírus/epidemiologia , Uganda/epidemiologia
5.
Mol Cell Biol ; 11(7): 3699-710, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2046673

RESUMO

ras oncogene-transformed NIH 3T3 cells expressing glucocorticoid-inducible antisense c-myc cDNA transcripts at levels sufficient to deplete c-myc protein lost their transformed morphology and the ability to grow in soft agar; their ability to form tumors in nude mice was also impaired. These changes were dependent on the continuous expression of the antisense sequences. No major effects on plating efficiencies, growth rates in monolayer culture, or immortalization were observed in the revertant cells, indicating that the observed effects were not a toxic consequence of c-myc protein depletion. Transfection with the same vector expressing c-myc in the sense orientation or other control vectors had no effect on transformation. These results suggest that a certain minimum level of expression of c-myc is required for the maintenance of ras transformation in NIH 3T3 cells.


Assuntos
Transformação Celular Neoplásica , DNA Antissenso/genética , Genes myc , Genes ras , Animais , Southern Blotting , Ciclo Celular , Divisão Celular , Linhagem Celular , Deleção Cromossômica , Vetores Genéticos , Cinética , Camundongos , Fenótipo , Plasmídeos , Proteínas Proto-Oncogênicas c-myc/análise , Proteínas Proto-Oncogênicas c-myc/genética , Transfecção
6.
J Natl Cancer Inst ; 54(5): 1249-53, 1975 May.
Artigo em Inglês | MEDLINE | ID: mdl-165315

RESUMO

Spleen cell cultures stimulated to DNA synthesis by antigen or mitogen were infected with Abelson virus, a C-type RNA virus inducing nonthymic lymphomas in mice. After 3 days the cells were transferred to mice and caused 100 percent incidence of lymphomas in as few as 29 days. That a number of the tumors were of donor origin, as shown by female karyotypes in recipient male mice, indicated that cells infected by virus in vitro were transformed. The process depended upon both virus and stimulation of lymphocytes in culture. Lymphoid tumors did not develop in mice receiving cells from virus-infected cultures not exposed to antigen or mitogen.


Assuntos
Transformação Celular Neoplásica , Vírus da Leucemia Murina , Baço , Animais , Células Cultivadas , DNA/biossíntese , Eritrócitos/imunologia , Técnicas In Vitro , Cariotipagem , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitógenos/farmacologia , Coelhos/imunologia , Baço/citologia , Baço/metabolismo , Replicação Viral
7.
Cancer Res ; 48(4): 793-7, 1988 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-3276398

RESUMO

The genetic basis of cellular resistance to the anticancer drug cis-diamminedichloroplatinum(II) (CP) is not well understood. In the course of identifying genes from human tumors capable of conferring resistance to CP, we tested the ability of several types of cellular and viral ras oncogene (H, K, and N) to alter the CP response of mouse cells. Using clonogenic assays, we found that NIH 3T3 fibroblasts transformed with missense mutation-activated ras oncogenes demonstrated substantially increased resistance to 1-h exposures to CP (P less than 0.05 to less than 0.001, at different drug concentrations), with 50% inhibitory concentration ratios (compared to NIH 3T3) of 4.5-8.5. Cells transformed with v-mos v-fms, and with a normal ras protooncogene activated by overproduction driven by an MLV ltr, demonstrate intermediate resistance (50% inhibitory concentration ratio, approximately 2.0). Cells transfected with the pSV2neo plasmid or with human genomic DNA that is not transforming had survival curves no different from those of NIH 3T3. ras genes are highly conserved in mammalian cells. Should these findings also prove to apply to human tumors, the presence of activated ras genes might help predict clinical response to CP.


Assuntos
Transformação Celular Neoplásica , Cisplatino/toxicidade , Genes ras , Animais , Linhagem Celular , Células Cultivadas , Clonagem Molecular , Resistência a Medicamentos , Humanos , Vírus do Sarcoma Murino de Kirsten/genética , Camundongos , Camundongos Endogâmicos , Transfecção
8.
Cancer Res ; 51(8): 2118-23, 1991 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-2009531

RESUMO

The molecular genetic basis for cancer cell resistance to the important family of platinum coordination complex drugs is poorly understood. The observation that malignant cells commonly become resistant to therapy, while normal cells rarely do, suggests that certain molecular processes involved in malignancy, e.g., oncogene activation, might also play a role in drug resistance. Since aberrant expression and amplification of various myc oncogenes have been implicated in the prognosis of human cancers, the poor therapeutic response of some of these tumors might be explained if high levels of myc gene products rendered cells more refractory to therapy. We tested this hypothesis by determining the effect of varying the level of c-myc expression on resistance to cis-platinum and ionizing radiation in Friend murine erythroleukemia cells expressing varying levels of c-myc gene product. We found that a) the degree of cis-platinum resistance correlated directly with the level of c-myc expression, b) glucocorticoid induction of murine mammary tumor virus promoter-driven c-myc sequences significantly increased cis-platinum resistance, c) restoring c-myc transcript levels to normal restored the original cis-platinum sensitivity at a rate which paralleled that of induced c-myc transcript depletion, and d) c-myc transcript level had no effect on ionizing radiation response. These findings suggest that c-myc levels may influence therapeutic success in some tumors and may regulate specific processes by which cells cope with DNA damage caused by DNA cross-linking agents such as the platinum analogues, but not ionizing radiation.


Assuntos
Cisplatino/metabolismo , Vírus da Leucemia Murina de Friend , Regulação Leucêmica da Expressão Gênica , Genes myc/genética , Leucemia Eritroblástica Aguda/genética , Ciclo Celular , Linhagem Celular , Resistência a Medicamentos/genética , Amplificação de Genes , Leucemia Eritroblástica Aguda/metabolismo , Transfecção/genética
9.
Mol Endocrinol ; 4(10): 1539-45, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2178219

RESUMO

The process of liver regeneration involves the concerted action of certain growth factors, which stimulate hepatocyte proliferation, and other antiproliferative factors, which prevent uncontrolled growth of this organ. Some of the biological actions of insulin-like growth factor-II (IGF-II), a mitogenic polypeptide closely related to insulin, may be mediated by the IGF-II receptor. This receptor consists of a single chain extracellular domain and a very small cytoplasmic domain, and can bind lysosomal enzymes that contain mannose-6-phosphate (M-6-P) residues. Since these enzymes may be involved in remodelling processes in certain tissues, we measured the expression of the IGF-II/M-6-P receptor in the liver after subtotal hepatectomy. Binding of [125I]IGF-II to crude plasma membranes from regenerating liver was maximal 2 days after hepatectomy (4.9% specific binding/60 micrograms protein) and subsequently decreased. Both control livers (livers removed at the time of operation) and sham-operated control livers demonstrated specific [125I]IGF-II binding of 1.1% throughout the experimental period. This increase in binding in regenerating liver was shown to be associated with an increase in the concentration of IGF-II receptor protein by means of Western blot analysis using a polyclonal anti-IGF-II/M-6-P receptor antiserum (3637). Similarly, steady state levels of IGF-II/M-6-P receptor mRNA, measured by solution hybridization/RNase protection assays, were significantly increased in the regenerating liver (2.0-fold over the control value 2 days after hepatectomy). Five and 10 days postsurgery, the levels of IGF-II receptor mRNA were markedly reduced, and they were even lower than the levels in control livers.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Regeneração Hepática/fisiologia , Receptores de Superfície Celular/metabolismo , Animais , Western Blotting , Membrana Celular/metabolismo , Hepatectomia , Fator de Crescimento Insulin-Like II/metabolismo , Fígado/metabolismo , Masculino , Manosefosfatos/metabolismo , Hibridização de Ácido Nucleico , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos , Receptor IGF Tipo 2 , Receptores de Superfície Celular/genética , Receptores de Somatomedina , Ribonucleases
10.
Endocrinology ; 130(6): 3484-91, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1317785

RESUMO

We have examined the developmental pattern of the insulin-like growth factor-II (IGF-II)/mannose 6-phosphate (M6P) receptor mRNA in various rat tissues from 20-day gestation fetuses and 20-day postnatal animals by Northern blotting and solution hybridization/RNase protection assays. The major mRNA species in all fetal and postnatal tissues was 9.0 kilobases. The rank order of receptor mRNA concentrations among the fetal tissues was heart greater than limb/muscle, lung, intestine, kidney, liver greater than brain, which agrees with the previously reported rank order of the tissue concentrations of receptor protein. The concentration of IGF-II/M6P receptor mRNA was significantly lower in postnatal tissues, again reflecting the relative levels of receptor protein in fetal and postnatal tissues. We measured IGF-II/M6P receptor mRNA copy number in fetal heart, the tissue with the highest concentration of receptor protein and mRNA, by including in the solution hybridization/RNase protection assay known amounts of a sense strand transcript of the receptor cDNA. This sense strand standard was quantitated by incorporating a tracer amount of [32P]UTP into the transcript and measuring the radioactivity in the product purified by gel electrophoresis. The receptor mRNA copy number in fetal heart was 74 molecules/cell. We conclude that the IGF-II/M6P receptor mRNA concentration is an important determinant of the level of receptor protein in most tissues.


Assuntos
RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Envelhecimento , Animais , Northern Blotting , Encéfalo/fisiologia , Clonagem Molecular , Feminino , Regulação da Expressão Gênica , Idade Gestacional , Intestinos/fisiologia , Rim/fisiologia , Fígado/fisiologia , Pulmão/fisiologia , Manosefosfatos/metabolismo , Músculos/fisiologia , Especificidade de Órgãos , Gravidez , RNA Mensageiro/genética , Ratos , Receptor IGF Tipo 2
11.
Int J Radiat Oncol Biol Phys ; 11(1): 49-55, 1985 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2981791

RESUMO

Despite impressive advances in the clinical management of Hodgkin's disease, little is known about its cellular origin or the mechanism(s) of "Hodgkinogenesis." Recent findings that certain human cellular oncogenes can cause malignant transformation suggest that aberrant activation of these genes may play a role in carcinogenesis. To determine if such genes are operative in Hodgkin's cells, we isolated DNA from splenic nodules of three patients with nodular sclerosis Hodgkin's disease and tested its ability to transform mouse NIH 3T3 cells, the standard assay for oncogene-mediated malignant transformation. Transformed cells containing human DNA were obtained from two patients. DNA from these primary transformants yielded secondary transformants of NIH 3T3 fibroblasts; one also transformed normal mouse bone marrow macrophages, a cell type probably related to the Hodgkin's cell. When analyzed by Southern blot methods for homology with closed oncogene probes, the transforming genes from both patients had homology with N-ras. The homology and size of the restriction fragments were similar to those of transforming genes isolated from patients with acute nonlymphocytic leukemias. The presence of the same activated oncogene in tumor tissue from two different patients suggests that it may play an important role in Hodgkinogenesis.


Assuntos
Transformação Celular Neoplásica , DNA de Neoplasias/genética , Doença de Hodgkin/genética , Oncogenes , Adolescente , Animais , Sequência de Bases , Linhagem Celular , Enzimas de Restrição do DNA , Eletroforese em Gel de Ágar , Feminino , Fibroblastos/patologia , Doença de Hodgkin/patologia , Humanos , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Hibridização de Ácido Nucleico , Transfecção
12.
Best Pract Res Clin Gastroenterol ; 15(6): 851-67, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11866481

RESUMO

Interviewing the elderly patient, typified by poor memory, often confused and sometimes hard of hearing, requires great patience and perseverance on the part of the physician to extract pertinent information from a complicated history involving past and present illnesses, multiple medications (both prescribed and over-the-counter), and social as well as economic issues. These circumstances may include retirement, death of a spouse and a change of living conditions. Assessment of these issues, followed by a careful physical examination, must lead to a diagnostic programme that is thorough yet practical, with consideration of the benefit of each procedure contemplated. The ultimate goal must be to renew the patient's ability to function as well as to improve the patient's quality of life. Many illnesses characteristic of the aged person are treatable but not curable. The goal is to improve the quality of life and to make the declining years as comfortable as possible. Typical cases illustrating these points are presented and discussed and their resolutions described.


Assuntos
Gastroenteropatias/diagnóstico , Geriatria/métodos , Anamnese/métodos , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Avaliação Geriátrica , Humanos , Masculino , Exame Físico/métodos , Qualidade de Vida
15.
Mol Reprod Dev ; 35(4): 408-13, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8398120

RESUMO

The first indication that the insulin-like growth factor-II/mannose 6-phosphate receptor (IGF-II/M6PR) is developmentally regulated came from studies of the serum form of the receptor in the rat. By immunoblotting, the circulating form of the receptor, which was 10 kDa smaller than the tissue receptor, was high in 19 day fetal and 3, 10, and 20 day postnatal sera and then declined sharply. We next used quantitative immunoblotting to measure the total tissue IGF-II/M6PR in the rat. The receptor levels were high in fetal tissues and in most tissues declined dramatically in late gestation and/or in the early postnatal period. The rank order of receptor expression was heart > placenta > lung = intestine > muscle = kidney > liver > brain. In heart, the receptor was 1.7% of total protein in the extract. More recently, we have examined the expression of IGF-II/M6PR mRNA using Northern blotting and a solution hybridization/RNase protection assay. The rank order of receptor mRNA concentration among fetal tissues agreed with the rank order of receptor protein. The concentration of receptor mRNA was significantly lower in postnatal tissue than in fetal tissue. Thus IGF-II/M6PR mRNA concentration is an important determinant of receptor protein in most tissues. What is the function of the IGF-II/M6PR in embryonic and fetal tissues? The M6PR in birds and frogs does not bind IGF-II. It is intriguing that the rat IGF-II/M6PR is prominent during the embryonic and fetal periods, times at which the differences between mammals, on the one hand, and frogs and birds, on the other, are most striking.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Envelhecimento/metabolismo , Desenvolvimento Embrionário e Fetal , Receptor IGF Tipo 2/biossíntese , Receptor IGF Tipo 2/genética , Animais , Regulação da Expressão Gênica , Especificidade de Órgãos , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , Ratos
16.
Can J Appl Sport Sci ; 7(3): 178-81, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6897020

RESUMO

This paper describes a program coded in BASIC, which efficiently provides management of certain track meet functions. In addition to generating heat and lane assignments, recording results, and scoring on an individual and team basis, the program allows coaches and officials to retrieve information on teams, participants, and events which are completed, in-progress, or upcoming. Utilization of the program requires neither computer programming experience, nor any related expertise.


Assuntos
Computadores , Software , Atletismo
17.
Proc Natl Acad Sci U S A ; 71(10): 4077-81, 1974 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-4372605

RESUMO

While C-type RNA viruses are known to induce leukemias and lymphomas, oncogenic transformation of lymphoid cells by them in vitro has not been reported. In this study, splenocytes from female BALB/c mice were infected in vitro with Abelson virus, a C-type RNA virus that induces nonthymic lymphomas and plasmacytomas in mice. The cells were transplanted into recipients of different karyotype, either male BALB/c mice or hybrid BALB/c x AL/N (CALF1) mice, which bear the Rb(5.19)1Wh translocation. Transplants of eight of the resulting tumors (one plasmacytoma and seven lymphomas) contained cells of donor BALB/c karyotype, indicating that transformation of splenocytes occurred in vitro.


Assuntos
Transformação Celular Neoplásica , Vírus da Leucemia Murina , Linfócitos , Retroviridae , Animais , Células Cultivadas , Feminino , Genótipo , Cariotipagem , Vírus da Leucemia Murina/crescimento & desenvolvimento , Linfoma/etiologia , Linfoma/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Neoplasias Experimentais/etiologia , Plasmocitoma/etiologia , Plasmocitoma/genética , Retroviridae/crescimento & desenvolvimento , Baço/citologia
18.
J Bacteriol ; 110(1): 291-9, 1972 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-4552993

RESUMO

Different patterns of isozymes were obtained by starch-gel electrophoresis of alkaline phosphatase from Escherichia coli strains differing only by strA or ram mutations, or both, in the 30S ribosomal subunit. The isozyme spread was reduced in strA and increased in ram strains; this strictly parallels the restriction and enhancement of translational ambiguity produced by these mutations. Streptomycin present during growth had an effect similar to ram on both isozymes and ambiguity. The three isozymes analyzed have different N-terminal residues: aspartic acid, valine, and threonine. Different patterns of isozymes were also obtained in a wild-type strain through the specific action of exogenous arginine. A link between the mechanism of the effect of arginine and that of the ribosome is not obvious. The possibility is discussed that in both cases, although by different mechanisms, N-terminals are formed with different sensitivity to limited degradative attack.


Assuntos
Fosfatase Alcalina/biossíntese , Escherichia coli/enzimologia , Ribossomos/fisiologia , Fosfatase Alcalina/análise , Fosfatase Alcalina/isolamento & purificação , Aminoácidos/análise , Arginina/farmacologia , Ácido Aspártico/análise , Cromatografia DEAE-Celulose , Compostos de Dansil , Eletroforese em Gel de Amido , Escherichia coli/citologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/fisiologia , Genética Microbiana , Isoenzimas/biossíntese , Mercaptoetanol , Mutação , Oxirredução , Desnaturação Proteica , Estreptomicina/farmacologia , Treonina/análise , Ureia , Valina/análise
19.
J Biol Chem ; 264(28): 16733-8, 1989 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-2550455

RESUMO

We used quantitative immunoblotting to measure the total tissue insulin-like growth factor II/mannose 6-phosphate (IGF-II/Man-6-P) receptor in the rat. Whole embryos (6-15 days of gestation) and tissues from 16- and 20-day-old fetal and 5-, 10-, 20-, and 40-day-old postnatal rats were placed in liquid nitrogen, extracted with 2% Triton X-100, and boiled in 2% sodium dodecyl sulfate. The extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis together with aliquots of a highly purified rat IGF-II/Man-6-P receptor standard. The protein bands were transferred from the gel to nitrocellulose sheets by electroelution. The nitrocellulose sheets were incubated with a specific IGF-II/Man-6-P receptor antiserum (3637). The immunoblots were developed with 125I-protein A and an immunoperoxidase stain. Stained areas were cut from the immunoblots, and radioactivity was measured in a gamma-counter. IGF-II/Man-6-P receptor levels were high in fetal tissues and in most tissues declined dramatically in late gestation and/or in the early postnatal period. Concentrations in 16-day-old fetal tissues, expressed as percent of total protein in the extract, were: heart, 1.7; placenta, 1.0; lung, 0.7; intestine, 0.7; muscle, 0.5; kidney, 0.5; liver, 0.3; and brain, 0.1. In whole embryos (6-15 days of gestation), the IGF-II/Man-6-P receptor ranged between 0.1 and 0.4% of total protein in the extract. The IGF-II/Man-6-P receptor size varied within approximately 20 kDa among different tissues and also varied with developmental age in the same tissue. We conclude that the IGF-II/Man-6-P receptor is a major cellular protein in some fetal tissues and that the developmental pattern of receptor expression suggests that the receptor plays an important role in fetal growth and development.


Assuntos
Envelhecimento/metabolismo , Desenvolvimento Embrionário e Fetal , Feto/metabolismo , Hexosefosfatos/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Manosefosfatos/metabolismo , Receptores de Superfície Celular/biossíntese , Somatomedinas/metabolismo , Animais , Immunoblotting , Especificidade de Órgãos , Ratos , Ratos Endogâmicos , Receptor IGF Tipo 2 , Receptores de Superfície Celular/análise , Receptores de Somatomedina
20.
Eur J Biochem ; 190(1): 71-7, 1990 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-2163834

RESUMO

The insulin-like growth-factor-II/mannose-6-phosphate (IGF-II/Man6P) receptor binds two classes of ligands, insulin-like growth factors and lysosomal enzymes. We have examined the ability of the lysosomal enzyme, beta-galactosidase, to modulate the binding of 125I-IGF-II to the receptor. beta-Galactosidase purified from bovine testis was fractionated on a DEAF-Sephacel ion-exchange column. Column fractions were assayed for enzymatic activity and for ability to inhibit the binding of 125I-IGF-II to the IGF-II/Man6P receptor. Enzyme fractions eluting at higher NaCl concentrations which had previously been shown to exhibit greater uptake by cells in culture, exhibited greater potency in inhibiting the binding of 125I-IGF-II to the receptor. A pool of these fractions from the DEAE-Sephacel column inhibited 125I-IGF-II binding to pure receptor by 80% with the concentration required for half-maximal inhibition being 25 nM. The inhibition of binding by beta-galactosidase was completely blocked by simultaneous incubation with Man6P. Inhibition of the enzymatic activity of beta-galactosidase with D-galactonic acid gamma-lactone did not affect the ability of beta-galactosidase to inhibit the binding of 125I-IGF-II to the receptor. Scatchard analysis of IGF-II binding to pure receptor in the presence and absence of beta-galactosidase showed that beta-galactosidase decreased the binding affinity for IGF-II (Kd 0.26 nM versus 1.0 nM in the presence of 57 nM beta-galactosidase). We confirmed the observations of others that Man6P alone actually increases the binding of 125I-IGF-II to the IGF-II/Man6P receptor, but we found that this phenomenon was dependent upon the method of preparation of the IGF-II/Man6P receptor. Microsomal membrane preparations, solubilized membranes, and receptors purified on an IGF-II-Sepharose column all exhibited stimulation of 125I-IGF-II binding by Man6P, whereas receptors purified on lysosomal enzyme affinity columns showed little or no stimulation of 125I-IGF-II binding by Man6P. We conclude that beta-galactosidase decreases the binding affinity of the IGF-II/Man-6-P receptor for IGF-II by binding with high affinity to the Man6P-recognition site.


Assuntos
Galactosidases/farmacologia , Fator de Crescimento Insulin-Like II/metabolismo , Receptores de Superfície Celular/metabolismo , Somatomedinas/metabolismo , beta-Galactosidase/farmacologia , Animais , Sítios de Ligação/efeitos dos fármacos , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Masculino , Receptor IGF Tipo 2 , Testículo/enzimologia
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