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1.
Osteoporos Int ; 31(12): 2461-2471, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32656632

RESUMO

The cost-effectiveness of surgical versus conservative medical management of vertebral compression fractures in the US was analyzed in the context of inpatient versus outpatient treatment. Surgical intervention (balloon kyphoplasty and vertebroplasty) was found to be cost-effective relative to conservative medical management at a US willingness-to-pay threshold. INTRODUCTION: To date, only one published study has evaluated the cost-effectiveness (C/E) of balloon kyphoplasty (BKP) or vertebroplasty (VP) in US Medicare patients with osteoporotic vertebral compression fractures. This study further evaluates the C/E of surgical treatment vs. conservative medical management (CMM), expanding on prior modeling by accounting for quality-adjusted life-years gained. METHODS: A Markov microsimulation model of 1000 patients was constructed. Cost data were based on an analysis of Medicare claims payments, with propensity-score matching performed for BKP and VP vs. controls (CMM). Mortality inputs were based on US life tables, modified to account for age at initial fracture, presence of subsequent fracture(s), and relative risk of mortality by treatment. Separate incremental cost-effectiveness ratios (ICERs) were calculated for BKP and VP in inpatient and outpatient surgical treatment locations to account for individual clinical profiles presenting to each. RESULTS: The discounted ICER for inpatient BKP vs. CMM was $43,455 per QALY gained; for outpatient BKP vs. CMM, $10,922; for inpatient VP vs. CMM, $39,774; and for outpatient VP vs. CMM, $12,293. Probabilistic sensitivity analysis confirmed that both BKP and VP would be considered C/E vs. CMM at a US willingness-to-pay (WTP) threshold of $50,000/QALY in 80% and 100% of 500 model simulations, respectively. The most sensitive parameters included quality of life estimates and hazard ratios for mortality. CONCLUSION: While VP and BKP are more expensive treatment options than CMM in the short term, model results suggest interventional treatment is cost-effective, among patients eligible for surgery, at a US WTP threshold. This conclusion supports those from economic analyses conducted in EU-member countries.


Assuntos
Fraturas por Compressão , Cifoplastia , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Vertebroplastia , Idoso , Análise Custo-Benefício , Feminino , Fraturas por Compressão/cirurgia , Humanos , Medicare , Fraturas por Osteoporose/cirurgia , Qualidade de Vida , Fraturas da Coluna Vertebral/cirurgia , Resultado do Tratamento , Estados Unidos/epidemiologia
2.
Climacteric ; 18(1): 94-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25029389

RESUMO

OBJECTIVES: Sexual dysfunction is a known complication of treatment for many cancers, but there have been relatively few studies investigating outcomes for ovarian cancer survivors. We have previously reported that women treated for ovarian cancer experience persistent psychological and physical problems. Sexual functioning was highlighted as a significant factor and we sought to investigate this further. METHODS: Women were invited to complete a questionnaire using both paper and online response formats. A validated tool, the Sexual Activity Questionnaire, was used to obtain information from women following a diagnosis of ovarian cancer. RESULTS: Across all responders (n = 102, mean age 51.3 years), 63% of women reported their ovarian cancer diagnosis had negatively changed their sex life. The most common reasons given for an absence of sexual activity were a lack of interest in sex, physical problems that prevented sex or no partner. Of the 46% of responders who stated they were sexually active, 77% reported pain or discomfort during intercourse and 87% described vaginal dryness. CONCLUSION: For the majority of women, treatment for ovarian cancer negatively impacts on their sex lives. Many of the symptoms described by participants are potentially reversible and clinicians should be open to raising the issue of sexual functioning with their patients.


Assuntos
Coito/fisiologia , Neoplasias Ovarianas/complicações , Comportamento Sexual/psicologia , Disfunções Sexuais Fisiológicas/etiologia , Sobreviventes/psicologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Internet , Pessoa de Meia-Idade , Qualidade de Vida , Inquéritos e Questionários , Adulto Jovem
3.
Science ; 194(4270): 1157-9, 1976 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-17790908

RESUMO

Large numbers of black metallic spherules ranging in diameter from a few micrometers to over 800 micrometers are raining into the eastern Gulf of Mexico and adjacent areas of western Florida. The composition of the flux, its association with glass spherules and coky particles, and its magnitude point to industrial pollution, probably coal- and coke-burning facilities around the perimeter of the gulf, as the source. Since metallic particles represent only a small fraction of most fly ash, such an influx of large numbers of black magnetic spherules must be symptomatic of a much higher rate of sedimentation of fly ash. The internal microstructures and the general appearance of spherules derived from industrial processes are similar to those of particles derived from cosmic sources. Because of the high potential for contamination in micrometeorite studies, a complete compositional verification of each "cosmic" particle may be necessary.

4.
Science ; 217(4557): 364-6, 1982 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-17791518

RESUMO

N-beta-Alanyldopamine is the major tyrosine metabolite in the hemolymph and cuticle during pupal tanning in the tobacco hornworm, Manduca sexta L. Its concentration in hemolymph increases over 800-fold above larval levels by the start of tanning and decreases as the pupal cuticle darkens and hardens. It is a major catechol in species representing several insect orders and is the preferred substrate for pupal cuticular o-diphenol oxidase. In insects, N-beta-alanyldopamine appears to be the main precursor for tanning chemicals at certain developmental stages.

5.
Science ; 235(4793): 1200-4, 1987 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-3823880

RESUMO

Cross-polarization magic-angle-spinning nuclear magnetic resonance spectroscopy has been used to determine insect cuticle composition and cross-link structure during sclerotization or tanning. Unsclerotized cuticle from newly ecdysed pupae of the tobacco hornworm, Manduca sexta L., had a high protein content with lesser amounts of lipid and chitin. Concentrations of chitin, protein, and catechol increased substantially as dehydration and sclerotization progressed. Analysis of intact cuticle specifically labeled with carbon-13 and nitrogen-15 revealed direct covalent linkages between ring nitrogens of protein histidyl residues and ring carbons derived from the catecholamine dopamine. This carbon-nitrogen adduct was present in chitin isolated from cuticle by alkaline extraction and is probably bound covalently to chitin. These data support the hypothesis that the stiffening of insect cuticle during sclerotization results primarily from the deposition of protein and chitin polymers and their crosslinking by quinonoid derivatives of catecholamines.


Assuntos
Reagentes de Ligações Cruzadas/metabolismo , Insetos/metabolismo , Pele/metabolismo , Animais , Isótopos de Carbono , Fenômenos Químicos , Química , Espectroscopia de Ressonância Magnética , Isótopos de Nitrogênio
6.
Science ; 232(4752): 847-9, 1986 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-17755966

RESUMO

Through a multidisciplinary project (AMERIEZ), with an unusual complement of components, previously unknown temporal and spatial dimensions to the structure of Antarctic epipelagic and mesopelagic communities were revealed. In late spring, an abundance of crustacean species thought to occur only below 300 meters was detected in ice-covered surface waters. Evident in ice-free waters were the expected occurrence patterns of these normally nonmigratory mesopelagic organisms. Where the pack was consolidated and little light penetrated to depth, primary and secondary production was confined to ice floes, and the physical environment immediately beneath the ice was reminiscent of a mesopelagic one. This suite of characteristics possibly explains why the crustaceans resided at the surface.

7.
J Nurs Educ ; 47(6): 254-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18557312

RESUMO

Due to the shortage of nurses in the health care industry, colleges offering associate-degree nursing programs are beginning to pay more attention to attrition and the factors contributing to success. Alogistic regression model was used to explain the cognitive and noncognitive variables that contribute to success in a nursing fundamentals course. Although much work is necessary to fully understand first-semester nursing students' retention and success, an early identification model is explored to better support students as they enter associate-degree nursing programs.


Assuntos
Educação Técnica em Enfermagem/organização & administração , Ensino de Recuperação/organização & administração , Evasão Escolar/educação , Estudantes de Enfermagem , Adolescente , Adulto , Análise de Variância , Cognição , Avaliação Educacional , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Modelos Educacionais , Modelos de Enfermagem , Modelos Psicológicos , Avaliação das Necessidades , Pesquisa em Educação em Enfermagem , Valor Preditivo dos Testes , Análise de Componente Principal , Apoio Social , Sudeste dos Estados Unidos , Evasão Escolar/psicologia , Evasão Escolar/estatística & dados numéricos , Estudantes de Enfermagem/psicologia , Estudantes de Enfermagem/estatística & dados numéricos , Fatores de Tempo
8.
Nat Biotechnol ; 17(5): 480-6, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10331809

RESUMO

A small catalytic DNA, known as the 10-23 DNA enzyme or deoxyribozyme, has been shown to efficiently hydrolyze RNA at purine-pyrimidine (R-Y) junctions in vitro. Although these potentially cleavable junctions are ubiquitous, they are often protected from deoxyribozyme activity by RNA secondary structure. We have developed a multiplex cleavage assay for screening the entire length of a target RNA molecule for deoxyribozyme cleavage sites that are efficient, both in terms of kinetics and accessibility. This strategy allowed us to simultaneously compare the RNA cleaving activity of 80 deoxyribozymes for a model target gene (HPV16 E6), and an additional 60 deoxyribozymes against the rat c-myc target. The human papilloma virus (HPV) target was used primarily to characterize the multiplex system and determine its validity. The c-myc target, coupled with a smooth muscle cell proliferation assay, allowed us to assess the relationship between in vitro cleavage efficiency and c-myc gene suppression in cell culture. The multiplex reaction approach streamlines the process of revealing effective deoxyribozymes in a functional assay and provides accessibility data that may also be applicable to site selection for other hybridization-based agents.


Assuntos
DNA de Cadeia Simples/metabolismo , RNA/metabolismo , Animais , Sequência de Bases , Células Cultivadas , DNA Catalítico , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Humanos , Dados de Sequência Molecular , Músculo Liso , Conformação de Ácido Nucleico , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Papillomaviridae/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA/química , Ratos
9.
Mol Biol Cell ; 6(12): 1861-73, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8590811

RESUMO

Basic fibroblast growth factor (FGF-2) is a pleiotropic growth factor detected in many different cells and tissues. Normally synthesized at low levels, FGF-2 is elevated in various pathologies, most notably in cancer and injury repair. To investigate the effects of elevated FGF-2, the human full-length cDNA was expressed in transgenic mice under control of a phosphoglycerate kinase promoter. Overexpression of FGF-2 caused a variety of skeletal malformations including shortening and flattening of long bones and moderate macrocephaly. Comparison by Western blot of FGF-2 transgenic mice to nontransgenic littermates showed expression of human FGF-2 protein in all major organs and tissues examined including brain, heart, lung, liver, kidney, spleen, and skeletal muscle; however, different molar ratios of FGF-2 protein isoforms were observed between different organs and tissues. Some tissues preferentially synthesize larger isoforms of FGF-2 while other tissues produce predominantly smaller 18-kDa FGF-2. Translation of the high molecular weight isoforms initiates from unconventional CUG codons and translation of the 18-kDa isoform initiates from an AUG codon in the FGF-2 mRNA. Thus the Western blot data from the FGF-2 transgenic mice suggest that tissue-specific expression of FGF-2 isoforms is regulated translationally.


Assuntos
Desenvolvimento Ósseo , Osso e Ossos/anormalidades , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/fisiologia , Regulação da Expressão Gênica , Biossíntese de Proteínas , Animais , Sequência de Bases , Western Blotting , Osso e Ossos/patologia , Primers do DNA , DNA Complementar , Fator 2 de Crescimento de Fibroblastos/biossíntese , Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Dados de Sequência Molecular , Especificidade de Órgãos , Fosfoglicerato Quinase/genética , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas
10.
Ecohealth ; 14(Suppl 1): 47-60, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26695615

RESUMO

Through the exploration of disease risk analysis methods employed for four different UK herpetofauna translocations, we illustrate how disease hazards can be identified, and how the risk of disease can be analysed. Where ecological or geographical barriers between source and destination sites exist, parasite populations are likely to differ in identity or strain between the two sites, elevating the risk from disease and increasing the number and category of hazards requiring analysis. Simplification of the translocation pathway through the avoidance of these barriers reduces the risk from disease. The disease risk analysis tool is intended to aid conservation practitioners in decision making relating to disease hazards prior to implementation of a translocation.


Assuntos
Conservação dos Recursos Naturais , Répteis , Animais , Ecologia , Geografia , Humanos , Medição de Risco
11.
Biochim Biophys Acta ; 527(2): 465-71, 1978 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-569499

RESUMO

Alanine-neochymotrypsinogen was prepared by incubating 20 parts bovine pancreas chymotrypsinogen A with one part alpha-chymotrypsin in a solution containing 1 M (NH4)2SO4, 0.1 M sodium acetate, 0.05 M Tris buffer (pH 8.0) and 0.5 mg/ml soybean trypsin inhibitor. Optimal yields of NH2-terminal alanine were obtained after 60 h incubation at 4 degrees C. Ala-neochymotrypsinogen was isolated from the reaction mixture by affinity chromatography and ion-exchange chromatography on carboxymethyl-cellulose. As expected, the purified preparation was enzymatically inactive and, compared to chymotrypsinogen, had one additional NH2-terminal group identified as alanine. Ala-neochymotrypsinogen was activated by incubating with trypsin at a zymogen : trypsin ratio of 30 : 1 in 0.1 M phosphate buffer, pH 7.6 at 4 degrees C for 1 h. The fully active, stable species was identified as alpha-chymotrypsin.


Assuntos
Quimotripsina/metabolismo , Quimotripsinogênio/metabolismo , Alanina , Animais , Bovinos , Fenômenos Químicos , Química , Estabilidade de Medicamentos , Ativação Enzimática , Cinética , Pâncreas/enzimologia , Desnaturação Proteica , Relação Estrutura-Atividade , Inibidores da Tripsina
12.
Biochim Biophys Acta ; 701(3): 413-6, 1982 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-7066338

RESUMO

A novel, active derivative of alpha-chymotrypsin was prepared from alanine-neochymotrypsinogen in which the epsilon-amino groups and the alpha-amino group of N-terminal Ala149 were acetylated. The catalytic properties at neutral and alkaline pH of this enzyme derivative were compared with those of a control alpha-chymotrypsin derivative in which only the epsilon-amino groups were acetylated. While the Km (app) of the two derivatives were the same at pH 7 to 8, at more alkaline pH the derivative having the masked Ala149 had much lower Km (app) values than the control. It is concluded that the inactivation of alpha-chymotrypsin at high pH is linked, at least in part, to the ionization state of its N-terminal Ala149 group.


Assuntos
Alanina , Quimotripsina/metabolismo , Acilação , Fenômenos Químicos , Química , Quimotripsinogênio , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Cinética , Relação Estrutura-Atividade , Tripsina
13.
Biochim Biophys Acta ; 1077(3): 400-6, 1991 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-2029539

RESUMO

Cyclic voltammetric and chronoamperometric data are consistent with a process in which 3,4-dihydroxymandelic acid (DOMA) is oxidized initially in a two-electron step to its corresponding o-benzoquinone. This species is unstable and undergoes the rate-determining loss of CO2 (k = 1.6 s-1 at pH 6 and 25 degrees C) to give an unobserved p-benzoquinone methide intermediate that rapidly isomerizes to 3,4-dihydroxybenzaldehyde (DOBAL), DOBAL is also electroactive at the applied potential and is oxidized in a two-electron step to 4-formyl-1,2-benzoquinone. Subsequent reactions of 4-formyl-1,2-benzoquinone include the oxidation of unreacted DOMA and the hydration of its aldehyde functional group. Oxidation of DOMA directly to its p-benzoquinone methide apparently does not occur. Derivatives of mandelic acid (e.g., 4-hydroxymandelic acid) that are expected to give only their corresponding p-benzoquinone methides upon oxidation afford redox behavior that differs distinctly from that for DOMA.


Assuntos
Benzaldeídos/metabolismo , Catecóis/metabolismo , Ácidos Mandélicos/metabolismo , Cromatografia Líquida de Alta Pressão , Descarboxilação , Eletroquímica , Concentração de Íons de Hidrogênio , Oxirredução
14.
J Biomater Appl ; 29(8): 1145-54, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25281648

RESUMO

Biodegradable magnesium metal filaments placed inside biodegradable nerve conduits might provide the physical guidance support needed to improve the rate and extent of regeneration of peripheral nerves across injury gaps. In this study, we examined basic issues of magnesium metal resorption and biocompatibility by repairing sub-critical size gap injuries (6 mm) in one sciatic nerve of 24 adult male Lewis rats. Separated nerve stumps were connected with poly(caprolactone) nerve conduits, with and without magnesium filaments (0.25 mm diameter, 10 mm length), with two different conduit filler substances (saline and keratin hydrogel). At 6 weeks after implantation, magnesium degradation was examined by micro-computed tomography and histological analyses. Magnesium degradation was significantly greater when the conduits were filled with an acidic keratin hydrogel than with saline (p < 0.05). But magnesium filaments in some animals remained intact for 6 weeks. Using histological and immunocytochemical analyses, good biocompatibility of the magnesium implants was observed at 6 weeks, as shown by good development of regenerating nerve mini-fascicles and only mild inflammation in tissues even after complete degradation of the magnesium. Nerve regeneration was not interrupted by complete magnesium degradation. An initial functional evaluation, determination of size recovery of the gastrocnemius muscle, showed a slight improvement due to magnesium with the saline but not the keratin filler, compared with respective control conduits without magnesium. These results suggest that magnesium filament implants have the potential to improve repair of injured peripheral nerve defects in this rodent model.


Assuntos
Implantes Absorvíveis , Magnésio , Regeneração Nervosa , Traumatismos dos Nervos Periféricos/cirurgia , Animais , Materiais Biocompatíveis , Hidrogéis , Queratinas , Masculino , Teste de Materiais , Músculo Esquelético/inervação , Músculo Esquelético/patologia , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/patologia , Poliésteres , Ratos , Ratos Endogâmicos Lew , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Nervo Isquiático/cirurgia , Microtomografia por Raio-X
15.
Oncogene ; 34(39): 5025-36, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-25531318

RESUMO

RNA-binding proteins (RBPs) bind to and post-transcriptionally regulate the stability of mRNAs. La-related protein 1 (LARP1) is a conserved RBP that interacts with poly-A-binding protein and is known to regulate 5'-terminal oligopyrimidine tract (TOP) mRNA translation. Here, we show that LARP1 is complexed to 3000 mRNAs enriched for cancer pathways. A prominent member of the LARP1 interactome is mTOR whose mRNA transcript is stabilized by LARP1. At a functional level, we show that LARP1 promotes cell migration, invasion, anchorage-independent growth and in vivo tumorigenesis. Furthermore, we show that LARP1 expression is elevated in epithelial cancers such as cervical and non-small cell lung cancers, where its expression correlates with disease progression and adverse prognosis, respectively. We therefore conclude that, through the post-transcriptional regulation of genes such as mTOR within cancer pathways, LARP1 contributes to cancer progression.


Assuntos
Autoantígenos/fisiologia , Neoplasias/patologia , Processamento Pós-Transcricional do RNA , Ribonucleoproteínas/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Animais , Progressão da Doença , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica , Metástase Neoplásica , RNA Mensageiro/genética , Antígeno SS-B
16.
Hypertension ; 27(3 Pt 2): 735-9, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8613233

RESUMO

We conducted this study to test the hypothesis that hypertension is a primary consequence of poor glycemic control per se very early in insulin-dependent diabetes mellitus. Sprague-Dawley rats (n=15) were instrumented with artery and vein catheters, placed in metabolic cages, and sodium intake was clamped throughout the study. Mean arterial pressure was measured 24 h/d. After a precontrol period, streptozotocin (70 mg/kg IV) was administered, and 15 hours later a continuous intravenous infusion was begun at 4 U/rat per day. The insulin infusion was titrated on an individual rat basis to maintain good glycemic control, and after this 7-day control period, blood glucose, urinary sodium excretion, and mean arterial pressure were not different from precontrol values, averaging 8.8 +/- 0.6 mmol/L, 2.8 +/- 0.2 mmol/d, and 103 +/- 2 mm/Hg, respectively, for control days 5 through 7. Subsequently, a 4-day period of poor glycemic control was initiated by reducing the insulin infusion rate. Blood glucose, urinary sodium excretion, and mean arterial pressure began to increase on day 1; for diabetes days 3 and 4, they averaged 23.4 +/- 1.0 mmol/L, 3.6 +/- 0.1 mmol/d, and 110 +/- 2 mm Hg, respectively. All were significantly elevated. When insulin treatment was restored, all variables returned to control levels during the next 4 days. A second 4-day diabetic period yielded similar results. These results indicate that elevated blood pressure is a primary consequence of poor glycemic control in insulin-dependent diabetes, occurring before renal injury has had time to develop, and therefore, may be a factor contributing to the initiation of end-organ injury.


Assuntos
Glicemia/análise , Diabetes Mellitus Experimental/complicações , Hipertensão/etiologia , Insulina/administração & dosagem , Animais , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/metabolismo , Infusões Intravenosas , Masculino , Ratos
17.
Insect Biochem Mol Biol ; 24(8): 787-802, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7981728

RESUMO

Two high molecular weight cuticular proteins (MSCP120 and MSCP246) were extracted in acidic guanidine hydrochloride solution from tanning abdominal cuticle of Manduca sexta pharate pupae and purified by size exclusion high performance liquid chromatography. The apparent molecular weights were ca. 120 and 246 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Both proteins contained high levels of glutamate/glutamine, glycine, serine, alanine and aspartate/asparagine. MSCP120 was enriched in histidine relative to MSCP246, but the reverse was true for valine and proline. Small quantities of beta-alanine and 3,4-dihydroxyphenylalanine (DOPA), as well as other catechols and carbohydrates, also were detected in the hydrolysates. The proteins became radiolabeled when [1-14C]-beta-alanine was injected into pharate pupae, presumably by the formation of adducts with N-beta-alanyldopamine metabolites during sclerotization. Mild acid hydrolysis released N-beta-alanylnorepinephrine and 3,4-dihydroxyphenylketoethanol from both proteins. Strong acid hydrolysis yielded predominantly 3,4-dihydroxyphenylketoethylamine (arterenone), but also DOPA and dopamine. The N-terminal amino acid sequences of the two cuticular proteins were dissimilar, and that of MSCP246 was more hydrophobic than MSCP120. Both of these proteins were glycosylated with glucose, N-acetylglucosamine and traces of N-acetylgalactosamine, and MSCP246 also contained galactose. These structural glycoproteins, which occur in cuticle undergoing sclerotization, apparently react post-translationally with quinonoid tanning agents to yield catecholamine-protein adducts. Small amounts of peptidyl DOPA probably are formed by hydroxylation of tyrosyl residues. Results from this study are consistent with the hypothesis that these catechol-containing glycoproteins participate in cross-linking reactions in M. sexta pupal cuticle during sclerotization.


Assuntos
Catecóis/análise , Glicoproteínas/química , Manduca/química , Aminoácidos/análise , Animais , Carboidratos/análise , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Glicoproteínas/isolamento & purificação , Glicoproteínas/metabolismo , Peso Molecular , Pupa
18.
Insect Biochem Mol Biol ; 33(3): 331-43, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12609518

RESUMO

Three proteins, MsCP20, MsCP27 and MsCP36, that are secreted in greatest quantity into the pharate pupal cuticle of Manduca sexta ( Hopkins et al., 2000) were purified and their amino acid sequences determined by mass spectrometry and Edman degradation. Although these proteins become sclerotized and insoluble in the pupal exoskeleton, their sequences contain features characteristic for proteins occurring in less sclerotized pliable cuticles, such as arthrodial membranes and soft larval cuticles. These proteins carry a secondary modification attached to a threonine residue, presumably an O-linked sugar moiety. cDNA clones of the genes for MsCP20, MsCP27 and MsCP36 were constructed from pharate pupal integument RNA. Close agreement was found between the amino acid sequences determined by Edman degradation and sequences deduced from the cDNA clones. The molecular masses determined by protein sequencing for MsCP20, MsCP27, and MsCP36 were 17713, 17448, and 29582 Da, respectively, in close agreement with the masses deduced from the corresponding cDNA clones (17711, 17410, and 29638 Da). Temporal expression analysis indicates that MsCP20 and MsCP36 transcripts are present at low levels early in the fifth larval stadium, followed by a large increase in abundance prior to pupal ecdysis. MsCP27 was not detected during development of the fifth larval instar, but its transcript, like those of MsCP20 and MsCP36, increased to a peak level just before pupal ecdysis. Only the MsCP36 transcript was detected in adults. These results support the hypothesis that these proteins are synthesized by the epidermis and are subsequently deposited into the cuticle during the larval-pupal transformation of M. sexta where they become sclerotized in the formation of pupal exocuticle.


Assuntos
Proteínas de Insetos/genética , Manduca/genética , Pupa/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Primers do DNA , DNA Complementar , Eletroforese em Gel de Poliacrilamida , Proteínas de Insetos/química , Manduca/crescimento & desenvolvimento , Dados de Sequência Molecular , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
19.
Insect Biochem Mol Biol ; 26(5): 475-84, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8763166

RESUMO

Three catecholamine-containing proteins from tanning, pharate pupal, abdominal cuticle of the tobacco hornworm, Manduca sexta, have been purified to apparent homogeneity and characterized. These proteins have apparent molecular masses of 32, 41 and 48 kDa and were shown by liquid chromatography-electrochemical analysis, after heating in 1 M acetic acid at 110 degrees C, to release nu-beta-alanylnorepinephrine (NBANE). NBANE is a hydrolysis product of N-beta-alanyldopamine (NBAD) that is bonded covalently at the beta-side-chain carbon to amino acid residues of cuticular proteins. Amino acid compositional analysis revealed that MS-PCP32 (32 KDa) has a high content of alanine (25.6%), valine (13.1%), proline (10.8%) and glycine (10%), a low level of phenylalanine, and no detectable tyrosine or methionine. In contrast, MS-PCP41 (41 kDa) had a much higher content of glycine (31.2%) and substantial levels of serine (9.2%), proline (10.2%) and glutamate/glutamine (10.6%), whereas tyrosine and phenylalanine were not detected. Two of the three purified proteins showed apparent similarities to each other in nu-terminal amino acid sequences, and to several other known insect cuticular proteins. Proteins MS-PCP41 and MS-PCP48 had the characteristic GGX triplet repeat, which is found in a variety of cuticular proteins and may be important for protein folding appropriate for cuticular functions. Therefore, a diversity of cuticular proteins with different amino acid sequences and properties apparently are secreted into the presumptive pupal exocuticle. These then can form adducts and possible cross-links with NBAD through its quinonoid intermediates during cuticular sclerotization.


Assuntos
Catecolaminas/análise , Manduca/química , Proteínas/química , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Proteínas/isolamento & purificação , Pupa
20.
Insect Biochem Mol Biol ; 30(1): 19-27, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10646967

RESUMO

Proteins in pupal abdominal cuticle of the tobacco hornworm, Manduca sexta, were characterized during the pre-ecdysial and post-ecdysial periods of sclerotization and endocuticle formation. Protein extractability decreased dramatically as the cuticle became sclerotized through 6 h post-ecdysis, but increased rapidly from 9 to 48 h as endocuticular layers were secreted. Nearly 100 proteins that were extracted from pre-ecdysial cuticle became largely insoluble during sclerotization. Three major proteins in this group destined to become exocuticle had apparent molecular masses (Mapp) of 20, 27 and 36 kDa, and were designated MS-PCP20, MS-PCP27, and MS-PCP36. Amino acid analysis revealed glycine to predominate in all three proteins, and alanine, aspartate, glutamate, proline and serine were also relatively abundant. Histidine residues, which provide sites for adduct and cross-link formation with quinone metabolites of N-beta-alanyldopamine during sclerotization of pupal cuticle, ranged from 2 to 3 mol %. N-Terminal amino acid analysis of MSPC-20 and MSPC-36 also revealed some sequence similarities indicating they may be related. An almost entirely new group of proteins appeared by 9 h as endocuticule secretion began, and these increased in abundance through 48 h post-ecdysis. Two of these were major proteins with Mapps of 33 and 34 kDa, and they also had close similarities in their N-terminal amino acid sequences. This study showed that the large number of proteins secreted into the presumptive exocuticle of the pupa before ecdysis are involved in sclerotization reactions and as a consequence become largely insoluble. The epidermis then switches to the secretion of an entirely new group of proteins that are involved in formation of the endocuticle.


Assuntos
Proteínas de Insetos/química , Manduca/química , Muda/fisiologia , Sequência de Aminoácidos , Animais , Catecolaminas , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva , Manduca/crescimento & desenvolvimento , Dados de Sequência Molecular
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