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1.
J Bone Joint Surg Br ; 88(6): 747-50, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16720767

RESUMO

We describe the results of arthrodesis for the treatment of recurrent acute neuropathic bone disease in 24 feet and of chronic disease with deformity in 91 feet, undertaken between January 1984 and December 2003. All were due to leprosy. Correction of the deformity was achieved in 80 of 106 feet (76%) and fusion in 97 of 110 feet (88%). In the 24 feet in which recurrent neuropathic bone disease was the reason for surgery, 17 (71%) obtained stability while in seven (29%) symptoms recurred postoperatively. Complications were experienced following 58 of the 110 operations (53%). In patients presenting primarily with deformity with a minimum follow-up of two years (79 feet), there was a reduced frequency of ulceration in 40 (51%). Normal footwear could be worn by 32 patients (40%) after surgery, while 40 (51%) required a moulded insole. Arthrodesis of the ankle in the neuropathic foot due to leprosy has a good overall rate of success although the rate of complications is high.


Assuntos
Artrodese/métodos , Artropatia Neurogênica/cirurgia , Deformidades Adquiridas do Pé/cirurgia , Doenças do Pé/cirurgia , Adolescente , Adulto , Idoso , Artrodese/efeitos adversos , Artropatia Neurogênica/etiologia , Criança , Feminino , Doenças do Pé/etiologia , Humanos , Hanseníase/complicações , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Sapatos , Resultado do Tratamento
2.
J Virol ; 79(3): 1487-99, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15650175

RESUMO

The tropism of Sindbis virus (SB) for cells of the dendritic cell (DC) lineage and the virulence of SB in vivo are largely determined by the efficacy of alpha/beta interferon (IFN-alpha/beta)-mediated antiviral responses. These responses are essentially intact in the absence of PKR and/or RNase L (K. D. Ryman, L. J. White, R. E. Johnston, and W. B. Klimstra, Viral Immunol. 15:53-76, 2002). In the present studies, we investigated the nature of antiviral effects and identity of antiviral effectors primed by IFN-alpha/beta treatment of bone marrow-derived DCs (BMDCs) generated from mice deficient in PKR and RNase L (TD). IFN-alpha/beta priming exerted significant antiviral activity at very early stages of SB replication and most likely inhibited the initial translation of infecting genomes. The early effect targeted cap-dependent translation as protein synthesis from an SB-like and a simple RNA were inhibited by interferon treatment, but an encephalomyocarditis virus internal ribosome entry site-driven element exhibited no inhibition. Phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 was defective after virus infection of TD cells, suggesting other mechanisms of translation inhibition. To identify components of these alternative antiviral pathway(s), we have compared global gene regulation in BMDCs derived from normal 129 Sv/Ev, IFNAR1-/-, and TD mice following infection with SB or treatment with IFN-alpha/beta. Candidate effectors of alternative antiviral pathways were those genes induced by virus infection or IFN-alpha/beta treatment in 129 Sv/Ev and TD-derived BMDC but not in virus-infected or IFN-alpha/beta-treated IFNAR1-/- cells. Statistical analyses of gene array data identified 44 genes that met these criteria which are discussed.


Assuntos
Antivirais/farmacologia , Células Dendríticas/virologia , Interferon-alfa/farmacologia , Interferon beta/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Sindbis virus/patogenicidade , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Células da Medula Óssea , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Chaperoninas/genética , Chaperoninas/metabolismo , Células Dendríticas/citologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas/genética , Proteínas/metabolismo , Proteínas/farmacologia , Proteínas de Ligação a RNA , Sindbis virus/genética , Sindbis virus/metabolismo , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo
3.
J Virol ; 73(5): 3682-91, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10196260

RESUMO

A viral mRNA of the late kinetic class expressed by murine cytomegalovirus (MCMV) contains an open reading frame (ORF) whose predicted protein, designated MCK-1, has homology to beta chemokines (M. R. MacDonald, X.-Y. Li, and H. W. Virgin IV, J. Virol. 71:1671-1678, 1997). The present study analyzed further the structure of the transcript in infected fibroblast cells. A splicing event removed the MCK-1 stop codon, bringing a downstream ORF into frame with the chemokine homolog and demonstrating that the MCK-1 ORF was an exon of a larger gene. The predicted 31.4-kDa protein, designated MCK-2, contains a putative amino-terminal signal sequence and a beta chemokine domain, followed by a carboxyl-terminal domain without significant homology to known proteins. Quantitative analysis of mRNA forms in MCMV-infected fibroblast cells at late times after infection indicated that the viral chemokine RNA was predominantly spliced. There was no evidence for expression of RNA encoding either MCK-1 or MCK-2 at immediate early or early times after infection with MCMV. Monoclonal antibodies generated against bacterially expressed MCK-2 recognized multiple proteins in the range of approximately 30 to approximately 45 kDa in Western blot analysis of MCK-2 expressed in transfected COS cells. The monoclonal antibodies immunoprecipitated a similar group of proteins in transfected COS cells metabolically labeled with radioactive cysteine. Radiolabelled protein of apparent higher molecular mass was immunoprecipitated from culture medium overlying the transfected cells, suggesting that posttranslationally modified MCK-2 can be secreted. Two proteins with apparent molecular mass suggestive of posttranslational modification were detected by Western blot analysis of cells harvested at late times after infection with MCMV. These studies show that MCMV encodes and expresses a beta chemokine homolog with a novel predicted structure.


Assuntos
Quimiocinas CC/genética , Muromegalovirus/genética , Splicing de RNA , RNA Viral , Sequência de Aminoácidos , Animais , Asparagina , Células COS , Linhagem Celular , Células Eucarióticas , Fibroblastos/metabolismo , Fibroblastos/virologia , Camundongos , Dados de Sequência Molecular , Polissacarídeos , Processamento de Proteína Pós-Traducional , RNA Mensageiro , Fatores de Tempo
4.
Arch Otolaryngol Head Neck Surg ; 124(12): 1315-20, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9865752

RESUMO

OBJECTIVE: To identify surface landmarks that can serve as reference points to the underlying musculature in the treatment of glabellar rhytids. METHODS: Fifty cadaver hemibrows were dissected to assess the location, disposition, and relationships of the brow muscles, along with their variations at each of several consistent locations. Particular attention was paid to the corrugator supercilii, frontal belly of the frontalis, and procerus muscles. CONCLUSIONS: The information gained here may be applied to the pharmacological or surgical treatment of glabellar rhytids. Knowledge of the frequent location of the muscles involved, relative to easily identifiable surface landmarks, allows a more precise approach.


Assuntos
Músculos Faciais/anatomia & histologia , Músculos Faciais/cirurgia , Feminino , Testa , Humanos , Masculino , Ritidoplastia/métodos
5.
J Virol ; 71(2): 1671-8, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8995698

RESUMO

A gene (HJ1) present in murine cytomegalovirus (MCMV) encodes an open reading frame (ORF) whose predicted amino acid sequence shows homology to the beta (or C-C) class of chemotactic cytokines known as chemokines. The region of homology is located in the carboxyl-terminal portion of the 116-amino-acid ORF. A 0.9-kb RNA transcript corresponding to the HJ1 gene is expressed in MCMV-infected fibroblasts and macrophages as a member of the late kinetic class of virally encoded transcripts. A transcriptional start site is located between the third and fourth methionine residues in the ORF, predicting a primary amino acid structure, starting at the fourth methionine residue, which includes a possible signal peptide as well as conserved cysteine residues typical for mammalian beta chemokines. The RNA transcript is polyadenylated, suggesting that it can undergo translation within the cytoplasm of an MCMV-infected cell. We speculate that expression of the chemokine homolog at late times in the MCMV replication cycle plays a role in MCMV pathogenesis, possibly by action as a chemotactic agonist or antagonist or by alteration of the activation or differentiation state of a susceptible cell such as a macrophage.


Assuntos
Quimiocinas/genética , Genes Virais , Muromegalovirus/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Regulação Viral da Expressão Gênica , Camundongos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
6.
Arch Otolaryngol Head Neck Surg ; 122(6): 664-70, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8639301

RESUMO

OBJECTIVE: To describe a new technique of polytef (Gore-Tex) implantation into the upper and lower lips and nasolabial grooves by using large implants as a method that achieves effective cosmetic improvement. SETTING: A private cosmetic surgery center. PARTICIPANTS: Thirty-three (female) patients who desired fuller lips and 62 patients (52 female and 10 male) who requested less prominent cheek lip grooves. MAIN OUTCOME MEASURE: Significant patient satisfaction after 12 to 54 months. RESULTS: Conspicuous aesthetic effect that related to both lip and nasolabial groove correction was documented. All patients but 4 (2 in each group) were pleased with the final outcome of the treatment. CONCLUSIONS: In the opinion of the authors, the threading technique of polytef implantation creates inconspicuous improvement-both in lip augmentation and nasolabial groove correction. Large polytef implants that were inserted through a tunneling technique produced consistently good results. Implants (lip augmentation: width, < or = 10 mm, and thickness, 4 mm; nasolabial groove correction: width, 8 mm, and thickness, < or = 8 mm) were found to be safe, simple, and effective.


Assuntos
Face/cirurgia , Lábio/cirurgia , Politetrafluoretileno , Próteses e Implantes , Cirurgia Plástica , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Complicações Pós-Operatórias
7.
J Virol ; 70(3): 1365-74, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8627652

RESUMO

Murine cytomegalovirus (MCMV) gene products dispensable for growth in cell culture are likely to have important functions within the infected host, influencing tissue tropism, dissemination, or immunological responses against the virus. To identify such genes, our strategy was to delete large regions of the MCMV genome likely to contain genes nonessential for virus replication in NIH 3T3 cells. Mutant virus RV7 contained a deletion of 7.7 kb spanning portions of MCMV HindIII-J and -I. This virus grew comparably to wild-type (WT) virus in NIH 3T3 fibroblasts, primary embryo fibroblasts, and bone marrow macrophages. However, RV7 failed to replicate in target organs of immunocompetent BALB/c mice and severe combined immunodeficient mice, which are exquisitely sensitive to MCMV infection. This defect in vivo growth may be related to the observation that RV7 grew poorly in the peritoneal macrophage cell line IC-21, which is highly permissive for growth of WT MCMV. Two other mutant viruses with an insertion or smaller deletion in the region common to the RV7 deletion grew comparably to WT virus in the macrophage cell line and replicated in salivary gland tissue. The poor growth of RV7 in IC-21 cells was due to a block in immediate-early gene expression, as levels of RNA from immediate-early gene IE1 were reduced eightfold compared with levels for WT virus in macrophages infected with RV7. Consequently, levels of RNA from early and late genes were also reduced. The lower expression of IE1 in RV7-infected IC-21 macrophages was not due to defective entry of virus into the cells, as equal amounts of viral DNA were present in cells 3 h after infection with RV7 or WT MCMV. These studies demonstrate that deletion of sequences in HindIII-J and -I confer altered cell and tissue tropism.


Assuntos
Deleção de Genes , Genes Virais , Muromegalovirus/genética , Muromegalovirus/fisiologia , Replicação Viral/genética , Células 3T3 , Animais , Linhagem Celular , Linhagem Celular Transformada , Células Cultivadas , Desoxirribonuclease HindIII , Feminino , Fibroblastos/citologia , Proteínas Imediatamente Precoces/metabolismo , Macrófagos/citologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Muromegalovirus/patogenicidade , Fases de Leitura Aberta , Gravidez , Recombinação Genética , Transativadores/metabolismo
8.
Arch Otolaryngol Head Neck Surg ; 122(3): 333-7, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8607963

RESUMO

Congenital cystic adenomatoid malformation of the lung is an uncommon anomaly. Two patients with this condition were recently referred to the Otolaryngology Service at The Hospital for Sick Children, Toronto, Ontario, for bronchoscopic evaluation of the airway to rule out a foreign body. Although history did not disclose a clear episode of aspiration in either case, chest radiographs showed unilateral lobar hyperinflation with mediastinal shift, consistent with foreign body obstruction. We report two cases to introduce congenital cystic adenomatoid malformation to the English otolaryngology literature and to increase awareness of it among otolaryngologists.


Assuntos
Malformação Adenomatoide Cística Congênita do Pulmão/diagnóstico , Corpos Estranhos/diagnóstico , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Pulmão , Masculino
10.
Head Neck ; 17(6): 487-93, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8847207

RESUMO

BACKGROUND: The patient with nasopharyngeal carcinoma (NPC) frequently is initially seen with regional node dissemination. Preliminary investigations suggest that the presence of Epstein-Barr virus (EBV) genomes in neck metastases from an occult primary may be diagnostic and predictive of NPC. The goal of this study was to test this proposition. METHODS: The polymerase chain reaction (PCR) was used to detect the presence of EBV DNA in fine-needle aspirate (FNA) samples obtained from malignant neck nodes. Control samples were obtained from other locations in the head and neck. PATIENTS: The patients in this study were evaluated at the Toronto Princess Margaret Hospital, a province-wide tertiary-care cancer treatment center. Of the 23 patients evaluated with malignant neck masses, 6 had NPC, 5 patients had metastatic squamous cell carcinoma of an unknown primary, and 12 patients served as controls with other known head and neck carcinomas. One of the patients initially diagnosed as an unknown primary later demonstrated NPC. FNA specimens were also obtained from 24 normal parotid, submandibular, or thyroid glands for comparison. RESULTS: In the samples with sufficient DNA for analysis, EBV was detected in 5 of 5 neck nodes from patients with known NPC. EBV was also detected in the neck node of a patient who went on to develop NPC and in a cervical node from 1 of 2 patients in whom the primary tumor remained unknown. None of the evaluable control neck nodes of FNA controls from other sites demonstrated EBV. CONCLUSIONS: These results demonstrate the utility of NPC-diagnostic EBV gene amplification in FNA samples of neck metastases and suggest that the presence of the EBV genome in FNA samples of neck nodes is predictive of the presence of NPC.


Assuntos
Biópsia por Agulha , Carcinoma/secundário , Carcinoma/virologia , Herpesvirus Humano 4/isolamento & purificação , Metástase Linfática/patologia , Neoplasias Nasofaríngeas/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/patologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/secundário , Carcinoma de Células Escamosas/virologia , Estudos de Coortes , DNA Viral/análise , Previsões , Amplificação de Genes , Genoma Viral , Herpesvirus Humano 4/genética , Humanos , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Primárias Desconhecidas/patologia , Neoplasias Primárias Desconhecidas/virologia , Glândula Parótida/patologia , Glândula Parótida/virologia , Reação em Cadeia da Polimerase , Estudos Prospectivos , Método Simples-Cego , Glândula Submandibular/patologia , Glândula Submandibular/virologia , Glândula Tireoide/patologia , Glândula Tireoide/virologia
11.
Cancer ; 75(9): 2307-12, 1995 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-7712442

RESUMO

BACKGROUND: The relationship between sinonasal inverted papilloma (IP) and various strains of human papilloma virus (HPV) has been examined previously. Yet there is little consensus regarding the incidence or role of HPV in IP. The possible role of Epstein-Barr virus (EBV), which, like HPV, is a DNA virus linked to human lymphoid and epithelial malignancies, was investigated. METHODS: The polymerase chain reaction (PCR) was used to detect EBV genomic sequences in surgical specimens of IP, in benign nasal polyps, and various control tissues. The IP specimens were similarly examined for the presence of HPV types 6, 11, 16, and 18. RESULTS: EBV DNA was found in 13 of 20 IP specimens (65%) and none of the 10 control tissues. Nine of the 20 specimens contained HPV DNA, and 5 of 20 specimens contained both EBV and HPV. CONCLUSIONS: These results imply a previously unsuspected role for Epstein-Barr virus in the pathogenesis of sinonasal inverted papilloma.


Assuntos
Genoma Viral , Herpesvirus Humano 4/genética , Neoplasias Nasais/microbiologia , Papiloma Invertido/microbiologia , Neoplasias dos Seios Paranasais/microbiologia , DNA Viral/análise , DNA Viral/genética , Genes Virais/genética , Infecções por Herpesviridae , Humanos , Pólipos Nasais/genética , Pólipos Nasais/microbiologia , Neoplasias Nasais/genética , Papiloma Invertido/genética , Papillomaviridae/classificação , Papillomaviridae/genética , Neoplasias dos Seios Paranasais/genética , Reação em Cadeia da Polimerase , Infecções Tumorais por Vírus
12.
J Otolaryngol ; 23(3): 151-9, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8064951

RESUMO

Carboplatin was introduced to the paediatric population as an alternative chemotherapeutic agent in the management of various malignant neoplasms, including sarcomas of the head and neck, in the hope that it would have fewer side effects than pre-existing agents. While many investigators have considered the ototoxicity of this drug only incidentally, others have presumed it to be of negligible importance. A recent animal model of its use has demonstrated damage to the inner hair cells of the cochlea, particularly at the basal turn, with a corresponding high incidence of hearing loss. Similarly, 11 of 22 patients who received this agent at the Hospital for Sick Children over the past 2 years demonstrated a sensorineural hearing loss in the 4 to 12 kHz range. This complication occurred as early as after the first dose and was generally progressively worse with subsequent doses. Consequently, we recommend careful audiologic monitoring of children receiving this agent.


Assuntos
Carboplatina/efeitos adversos , Cóclea/efeitos dos fármacos , Audição/efeitos dos fármacos , Adolescente , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Audiometria de Tons Puros , Limiar Auditivo/efeitos dos fármacos , Carboplatina/administração & dosagem , Criança , Pré-Escolar , Chinchila , Cóclea/ultraestrutura , Feminino , Células Ciliadas Auditivas Internas/efeitos dos fármacos , Células Ciliadas Auditivas Internas/ultraestrutura , Transtornos da Audição/induzido quimicamente , Perda Auditiva de Alta Frequência/induzido quimicamente , Perda Auditiva Neurossensorial/induzido quimicamente , Humanos , Masculino , Neoplasias/tratamento farmacológico , Estudos Prospectivos
14.
J Allergy Clin Immunol ; 91(3): 752-7, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8454798

RESUMO

BACKGROUND: Thirty-nine male subjects, with new-onset wheezing, were selected from participants in the Department of Veterans Affairs Normative Aging Study and compared with 74 age-matched controls. Wheezing was defined by responses to a standardized and regularly administered questionnaire. The subjects with wheezing had a reduced FEV1 compared with controls (p = 0.005), but most had values above 80% predicted. Current smoking was more common in subjects with wheezing (36.8% vs 8.11% in controls, p < 0.001). The mean age of both subjects and controls was 64 years. METHODS: Allergen-specific IgE antibodies were measured, starting with sera at the time of the most recent questionnaire, and on the average 3.1, 7.6, and 12.3 years before that, with use of stored serum samples. RESULTS: Total IgE did not differ significantly between the groups. IgE binding to dust mite antigen was detected in 13% to 15% of the subjects with wheezing compared with fewer than 7% of the controls over four time intervals (p = 0.014). IgE binding to cat and ragweed antigens did not differ significantly between groups. If current nonsmokers were analyzed separately, IgE binding to cat allergen was also slightly greater in subjects with wheezing compared with controls (p = 0.054). Sequential analysis of IgE antibody levels to mite antigen, over time, indicated that IgE antibody antedated the onset of wheezing. CONCLUSIONS: New-onset wheezing in an older adult male population is significantly associated with allergic sensitization to dust mite. There was a borderline association with sensitization to cat in noncurrent smokers only. This supports the hypothesis that a subgroup may have allergic triggers to their symptoms.


Assuntos
Envelhecimento/imunologia , Alérgenos/imunologia , Sons Respiratórios/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Humanos , Imunoglobulina E/análise , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Ácaros/imunologia , Mecânica Respiratória , Sons Respiratórios/fisiopatologia , Fumar , Inquéritos e Questionários
16.
J Biol Chem ; 264(26): 15578-92, 1989 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2768279

RESUMO

The rat preprotachykinin I gene mRNA is alternatively spliced to yield three different mRNA species differing in their protein coding regions. We have produced recombinant vaccinia viruses expressing alpha-, beta-, and gamma-preprotachykinin to examine the tachykinin-related peptides produced upon post-translational processing of each individual precursor. Infection of BSC-40 or AtT-20 cell lines with a beta-preprotachykinin-encoding vaccinia virus recombinant results in the expression of the precursor protein. The pro-form (signal peptide removed) can be immunoprecipitated from extracts of infected cells. Infected cells of both types secrete into the culture medium a product(s) which reacts in radioimmunoassay with an antiserum shown to recognize precursor as well as mature substance P. Infected AtT-20, but not BSC-40, cells secrete into the culture medium a processed form(s) of beta-preprotachykinin which reacts in radioimmunoassay with an anti-serum which recognizes the amidated carboxyl terminus of substance P. The molecular nature of the tachykinin products produced in and secreted from AtT-20 cells infected with alpha-, beta-, and gamma-preprotachykinin-encoding recombinants was analyzed by combined high performance liquid chromatography and radioimmunoassay. Peptides were identified based on comigration with synthetic standards and antisera cross-reactivity. We determined that alpha-preprotachykinin is processed to the mature undecapeptide, substance P. beta-Preprotachykinin was processed into multiple products, including substance P, neurokinin A, neurokinin A(3-10), and neuropeptide K. gamma-Preprotachykinin was processed into substance P, neurokinin A, neurokinin A(3-10), and neuropeptide gamma. These five tachykinin peptide products were all routed through the regulated secretory pathway and were secreted into the medium in a cAMP-stimulatable fashion. Since all of these peptides have been shown to be biologically active, it is important to consider the biological consequences of their co-secretion in vivo.


Assuntos
Transformação Celular Viral , Precursores de Proteínas/genética , Processamento de Proteína Pós-Traducional , Taquicininas/genética , Vaccinia virus/genética , Animais , Linhagem Celular , RNA Polimerases Dirigidas por DNA/metabolismo , Vetores Genéticos , Neoplasias Hipofisárias , Plasmídeos , Radioimunoensaio , Taquicininas/biossíntese , Transcrição Gênica
17.
Bioessays ; 10(2-3): 62-9, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2470367

RESUMO

Substance P and related tachykinin peptides probably act as neurotransmitters or modulators of neurotransmission, and regulate biological processes as diverse as salivary secretion and transmission of pain signals. Substance P peptide sequences are expressed in three distinct mRNAs that are generated from one gene by differential RNA splicing. In addition to substance P, as many as three other tachykinin peptides can be generated from the polyprotein precursors by differential posttranslational processing. Three tachykinin receptor subtypes have been extensively characterized which differentially interact with the naturally occurring tachykinin peptides. Therefore, the generation of diversity of tachykinin peptides results from differential precursor RNA splicing and differential posttranslational processing. The specificity of peptide responses is the result of selective receptor subtype expression.


Assuntos
Precursores de Proteínas/genética , Substância P/genética , Taquicininas/genética , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Receptores de Neurotransmissores/metabolismo , Receptores de Taquicininas , Taquicininas/metabolismo
18.
Cancer Res ; 41(8): 3035-9, 1981 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6788366

RESUMO

The effect of 5'-deoxy-5'-methylthioadenosine (MTA) on the growth of culture murine lymphoid cells was examined. MTA inhibited the growth of murine lymphoid cell lines of both B- and T-cell origin in a reversible, nontoxic, and dose-dependent fashion. When measured 2 days after the addition of MTA to the cells, the concentration that inhibited proliferation by 50% for MTA was about 250 muM. Cells incubated in the presence of 0.5 mM MTA for 1, 2, or 3 days were able to recover from the inhibitory effect of the nucleoside and resumed growth. Six structural analogs of MTA were also found to inhibit cell growth. Five of these analogs served as alternative substrates for MTA phosphorylase, while one, the 7-deaza analog (5'-deoxy-5'-methylthiotubercidin), was not a substrate for the phosphorylase but was a potent inhibitor of enzyme activity. Inhibition of growth by 5'-deoxy-5'-methylthiotubercidin was dose dependent (the concentration that inhibited proliferation by 50% approximately or equal to 10 muM) and at 50 muM was reversible and nontoxic.


Assuntos
Adenosina/análogos & derivados , Divisão Celular/efeitos dos fármacos , Desoxiadenosinas , Linfócitos/citologia , Tionucleosídeos/farmacologia , Adenosina/metabolismo , Adenosina/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Camundongos , Purina-Núcleosídeo Fosforilase/metabolismo , Tionucleosídeos/metabolismo , Tubercidina/análogos & derivados , Tubercidina/farmacologia
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