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1.
Nature ; 580(7802): 216-219, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32269349

RESUMO

Present estimates suggest that of the 359 million tons of plastics produced annually worldwide1, 150-200 million tons accumulate in landfill or in the natural environment2. Poly(ethylene terephthalate) (PET) is the most abundant polyester plastic, with almost 70 million tons manufactured annually worldwide for use in textiles and packaging3. The main recycling process for PET, via thermomechanical means, results in a loss of mechanical properties4. Consequently, de novo synthesis is preferred and PET waste continues to accumulate. With a high ratio of aromatic terephthalate units-which reduce chain mobility-PET is a polyester that is extremely difficult to hydrolyse5. Several PET hydrolase enzymes have been reported, but show limited productivity6,7. Here we describe an improved PET hydrolase that ultimately achieves, over 10 hours, a minimum of 90 per cent PET depolymerization into monomers, with a productivity of 16.7 grams of terephthalate per litre per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET). This highly efficient, optimized enzyme outperforms all PET hydrolases reported so far, including an enzyme8,9 from the bacterium Ideonella sakaiensis strain 201-F6 (even assisted by a secondary enzyme10) and related improved variants11-14 that have attracted recent interest. We also show that biologically recycled PET exhibiting the same properties as petrochemical PET can be produced from enzymatically depolymerized PET waste, before being processed into bottles, thereby contributing towards the concept of a circular PET economy.


Assuntos
Hidrolases/química , Hidrolases/metabolismo , Plásticos/química , Plásticos/metabolismo , Polietilenotereftalatos/química , Polietilenotereftalatos/metabolismo , Engenharia de Proteínas , Reciclagem , Actinobacteria/enzimologia , Burkholderiales/enzimologia , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/metabolismo , Dissulfetos/química , Dissulfetos/metabolismo , Ensaios Enzimáticos , Estabilidade Enzimática , Fusarium/enzimologia , Modelos Moleculares , Ácidos Ftálicos/metabolismo , Polimerização , Thermobifida
2.
J Fr Ophtalmol ; 39(5): 415-20, 2016 May.
Artigo em Francês | MEDLINE | ID: mdl-27155911

RESUMO

PURPOSE: To describe a technique for extemporaneously drawing up bevacizumab for intravitreal injection (IVT) and report the rate of post-injection endophthtalmitis. PATIENTS AND METHODS: Retrospective monocentric analysis (January 2010-December 2014) of all IVT of bevacizumab drawn up with the following technique: in the operating room (class ISO 7) through a mini-spike with an integrated bacteria retentive air filter. The surgeon was wearing sterile gloves and a mask. The assisting nurse wore a mask. The bevacizumab vial was discarded at the end of each session. RESULTS: Six thousand two hundred and thirty-six bevacizumab injections were performed. One case of endophthalmitis was noted (0.016%). During the same period, 4 cases of endophthalmitis were found after IVT of other drugs (4/32,992; 0.012%. P=0.8). CONCLUSION: Intravitreal injection of bevacizumab after extemporaneous withdrawal through a mini-spike filter is a simple and safe technique. The risk of postoperative endophthalmitis is very low. This simple technique facilitates access to compounded bevacizumab.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Bevacizumab/administração & dosagem , Contaminação de Medicamentos/prevenção & controle , Infecções Oculares Bacterianas/prevenção & controle , Injeções Intravítreas/métodos , Degeneração Macular/tratamento farmacológico , Filtros Microporos , Inibidores da Angiogênese/efeitos adversos , Bevacizumab/efeitos adversos , Composição de Medicamentos/instrumentação , Composição de Medicamentos/métodos , Contaminação de Medicamentos/estatística & dados numéricos , Endoftalmite/epidemiologia , Endoftalmite/prevenção & controle , Infecções Oculares Bacterianas/epidemiologia , Infecções Oculares Bacterianas/etiologia , Humanos , Injeções Intravítreas/efeitos adversos , Injeções Intravítreas/instrumentação , Injeções Intravítreas/normas , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Comportamento de Redução do Risco
3.
Scand J Med Sci Sports ; 23(6): 705-12, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22353227

RESUMO

This study aimed to examine if the faster pulmonary oxygen uptake (VO2p) phase 2 in children could be explained by increased O2 availability or extraction at the muscle level. For that purpose, O2 availability and extraction were assessed using deoxyhemoglobin (HHb) estimated by near-infrared spectroscopy during moderate-intensity constant load cycling exercise in children and young adults. Eleven prepubertal boys and 12 men volunteered to participate in the study. They performed one maximal graded exercise to determine the power associated with the gas exchange threshold (GET) and four constant load exercises at 90% of GET. VO2p and HHb were continuously monitored. VO2p , HHb, and estimated capillary blood flow (Qcap) kinetics were modelled after a time delay and characterized by the time to achieve 63% of the amplitude (τ) and by mean response time (MRT: time delay + τ), respectively. Mean values of τ for VO2p (P < 0.001), of MRT for HHb (P < 0.01) and of MRT for Qcap (P < 0.001) were significantly shorter in children. Faster VO2p kinetics have been shown in children; these appear due to both faster O2 extraction and delivery kinetics as indicated by faster HHb and Qcap kinetics, respectively.


Assuntos
Desenvolvimento Infantil/fisiologia , Exercício Físico/fisiologia , Pulmão/metabolismo , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Oxigênio/fisiologia , Capilares/fisiologia , Criança , Teste de Esforço , Hemoglobinas/análise , Humanos , Cinética , Masculino , Troca Gasosa Pulmonar , Fluxo Sanguíneo Regional/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
4.
Psychoneuroendocrinology ; 37(6): 844-51, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22029953

RESUMO

The endocannabinoid system is known to have positive effects on depression partly through its actions on neurotrophins, such as Brain-Derived Neurotrophic Factor (BDNF). As BDNF is also considered the major candidate molecule for exercise-induced brain plasticity, we hypothesized that the endocannabinoid system represents a crucial signaling system mediating the beneficial antidepressant effects of exercise. Here we investigated, in 11 healthy trained male cyclists, the effects of an intense exercise (60 min at 55% followed by 30 min at 75% W(max)) on plasma levels of endocannabinoids (anandamide, AEA and 2-arachidonoylglycerol, 2-AG) and their possible link with serum BDNF. AEA levels increased during exercise and the 15 min recovery (P<0.001), whereas 2-AG concentrations remained stable. BDNF levels increased significantly during exercise and then decreased during the 15 min of recovery (P<0.01). Noteworthy, AEA and BDNF concentrations were positively correlated at the end of exercise and after the 15 min recovery (r>0.66, P<0.05), suggesting that AEA increment during exercise might be one of the factors involved in exercise-induced increase in peripheral BDNF levels and that AEA high levels during recovery might delay the return of BDNF to basal levels. AEA production during exercise might be triggered by cortisol since we found positive correlations between these two compounds and because corticosteroids are known to stimulate endocannabinoid biosynthesis. These findings provide evidence in humans that acute exercise represents a physiological stressor able to increase peripheral levels of AEA and that BDNF might be a mechanism by which AEA influences the neuroplastic and antidepressant effects of exercise.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Moduladores de Receptores de Canabinoides/sangue , Depressão/sangue , Endocanabinoides , Exercício Físico/fisiologia , Recompensa , Adulto , Amidas , Ácidos Araquidônicos/sangue , Ciclismo/fisiologia , Cromatografia Líquida de Alta Pressão , Etanolaminas/sangue , Glicerídeos/sangue , Hematócrito , Humanos , Masculino , Espectrometria de Massas , Ácidos Oleicos , PPAR alfa/metabolismo , Ácidos Palmíticos/sangue , Alcamidas Poli-Insaturadas/sangue , Adulto Jovem , beta-Endorfina/sangue
5.
Genomics ; 83(4): 658-66, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15028288

RESUMO

Palate, lung, and nasal epithelium clone (Plunc, now renamed Splunc1) is a small secreted protein expressed in the oropharynx and upper airways of humans, mice, rats, and cows. This protein is structurally homologous to known mediators of host defense against gram-negative bacteria. We have characterized the genomic sequence and expression of a novel but closely related gene from rodents, which we call splunc5. Mouse Splunc5 sequence is 60% identical to mouse Splunc1. The genes also share highly conserved genomic elements including intron-exon structure and intronic sequence. Strikingly, splunc5 is expressed exclusively in the interpapillary epithelium of the tongue's dorsal surface. By comparing the expression profiles of splunc5, splunc1, and a third related sequence, lplunc1, in mice, we show that these genes are expressed in unique domains along a continuous corridor of oral, lingual, pharyngeal, and respiratory epithelia. This expression pattern is consistent with the hypothesis that these proteins protect epithelial surfaces colonized by potentially pathogenic microorganisms.


Assuntos
Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Glicoproteínas/biossíntese , Glicoproteínas/genética , Fosfoproteínas/biossíntese , Fosfoproteínas/genética , Biossíntese de Proteínas , Proteínas/genética , Língua/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Éxons , Hibridização In Situ , Íntrons , Camundongos , Camundongos Endogâmicos C57BL , Modelos Genéticos , Dados de Sequência Molecular , Família Multigênica , RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glândulas Salivares/metabolismo , Homologia de Sequência do Ácido Nucleico , Distribuição Tecidual
6.
J Dent Res ; 82(12): 944-50, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14630892

RESUMO

An expanding number of innate immune molecules occupy the "epithelial frontier". This review introduces a recently recognized class of mammalian proteins with similarity to PLUNC (palate, lung and nasal epithelium clone), which is itself related to the host defense protein BPI (bactericidal/permeability-increasing protein). Four emerging lines of evidence unite the PLUNC-like proteins: conserved genetic structure, epithelial expression, three-dimensional protein similarity, and a physiological response to injury or inflammation. By analogy to known proteins of the innate immune system, an emerging hypothesis for this family is that they act as sensors of Gram-negative bacteria in the oral cavity, among other areas.


Assuntos
Atividade Bactericida do Sangue/imunologia , Proteínas Sanguíneas/imunologia , Glicoproteínas/imunologia , Zíper de Leucina/imunologia , Proteínas de Membrana/imunologia , Mucosa Bucal/imunologia , Fosfoproteínas/imunologia , Peptídeos Catiônicos Antimicrobianos , Epitélio/imunologia , Bactérias Gram-Negativas/imunologia , Humanos , Imunidade Inata/imunologia
7.
J Fr Ophtalmol ; 26(6): 570-6, 2003 Jun.
Artigo em Francês | MEDLINE | ID: mdl-12910195

RESUMO

INTRODUCTION: Internal limiting membrane peeling has recently given interesting results in the management of macular edema in diabetic patients, even in the absence of vitreomacular tractions. This study was conducted to evaluate the results of a surgical treatment for macular edema resulting from branch retinal vein occlusion. MATERIAL AND METHODS: A nonrandomized prospective study was conducted between March 2001 and April 2002 on 12 eyes of 12 consecutive patients with a visual acuity of 20/40 or less resulting from branch retinal vein occlusion with macular edema. Internal limiting membrane peeling associated with arteriovenous crossing sheathotomy was performed on six eyes and internal limiting membrane peeling alone was performed on six eyes. Patients were tested with ETDRS visual acuity, fluorescein angiography, automated perimetry, and OCT pre- and postoperatively (at 3 and 6 months). RESULTS: At 6 months, postoperative visual acuity was improved in all patients (mean VA=20/40; range, 20/125-20/20), with an average gain of three lines of vision (or 14 ETDRS points) (p=0.002). Fundus examination and fluorescein angiography results were improved in all patients. At 6 months, on automated field testing, the mean corrected defect improved from 3.4+/-0.9dB to 2.3+/-0.9dB (p=0.008). On OCT, mean foveal thickness decreased from 419+/-57 micro m to 233+/-10 micro m (p=0.02). No difference was noted between simple vitrectomy with internal limiting membrane peeling and arteriovenous crossing sheathotomy in terms of visual acuity (p=0.5), visual field (p=0.2), or foveal thickness (p=0.6) improvement. CONCLUSION: Our findings suggest that internal limiting membrane removal for macular edema may improve the functional prognosis in patients with branch retinal vein occlusion. Adventitial sheathotomy did not yield further functional benefits in these cases.


Assuntos
Degeneração Macular/cirurgia , Oclusão da Veia Retiniana/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Angiofluoresceinografia , Humanos , Degeneração Macular/etiologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Resultado do Tratamento , Vitrectomia/métodos
8.
J Fr Ophtalmol ; 26(6): 577-85, 2003 Jun.
Artigo em Francês | MEDLINE | ID: mdl-12910196

RESUMO

PURPOSE: To describe the results of radial optic neurotomy for the treatment of severe central retinal vein occlusion. PATIENTS AND METHODS: Prospective noncomparative single-center study. Analysis of ten eyes of ten consecutive patients whose visual acuity was 0.1 or less. They underwent fluorescein angiography, visual field testing by automated perimetry, and macular thickness analysis by optical coherence tomography preoperatively at 3 months and at 6 months postoperatively. RESULTS: Mean visual acuity on an ETDRS chart increased from 30+/-12 points preoperatively to 42+/-15 points at the 3-month visit, (p=0.03), and mean macular thickness decreased from 580+/-150 micro m to 361+/-52 micro m (p=0.04). All patients had clinical improvement as determined by fundus examination and fluorescein angiography. An improvement in the central visual field was observed in all eyes. Mean visual acuity of the five patients followed-up for 6 months was 52.8+/-20 points. No visual loss was observed. None of the patients underwent laser photocoagulation or has presented with neovascularization so far. Optociliary veins developed in three eyes and a retinochoroidal anastomosis within the disk incision was observed in two eyes. CONCLUSION: These preliminary results are encouraging when compared to the reported natural progression of severe central retinal vein occlusion. A bypass of the site of occlusion is a possible mechanism for radial optic neurotomy. A randomized study should be conducted to assess the efficacy of radial optic neurotomy and determine the best candidates for surgery.


Assuntos
Nervo Óptico/cirurgia , Oclusão da Veia Retiniana/cirurgia , Idoso , Feminino , Angiofluoresceinografia , Seguimentos , Glaucoma/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Acuidade Visual
9.
Biochem Soc Trans ; 31(Pt 4): 801-5, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12887309

RESUMO

A cluster of related genes whose products show structural identity with bactericidal permeability-increasing protein (BPI) has been identified in the genomes of both mice (on chromosome 2) and humans (on chromosome 20). Genes in the cluster include those encoding parotid secretory protein (PSP), von Ebner minor salivary gland protein (VEMSGP) and sequences in the PLUNC (palate, lung and nasal epithelium clone) family, among others. This mini-review addresses the tissue-specific expression of these genes in the mouse.


Assuntos
Proteínas Sanguíneas/genética , Proteínas de Transporte/biossíntese , Glicoproteínas/biossíntese , Mucosa Intestinal/metabolismo , Proteínas de Membrana , Mucosa Bucal/metabolismo , Fosfoproteínas/biossíntese , Mucosa Respiratória/metabolismo , Proteínas e Peptídeos Salivares/biossíntese , Animais , Peptídeos Catiônicos Antimicrobianos , Proteínas de Transporte/genética , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Glicoproteínas/genética , Humanos , Mucosa Intestinal/fisiologia , Lipocalina 1 , Camundongos , Mucosa Bucal/citologia , Mucosa Bucal/fisiologia , Fosfoproteínas/genética , Mucosa Respiratória/fisiologia , Proteínas e Peptídeos Salivares/genética
10.
J Exp Zool ; 291(3): 274-81, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11598915

RESUMO

The turtle shell, an evolutionarily novel structure, contains a bony exoskeleton that includes a dorsal carapace and a ventral plastron. The development of the carapace is dependent on the carapacial ridge (CR), a bulge in the dorsal flank that contains an ectodermal structure analogous to the apical ectodermal ridge (AER) of the developing limb (Burke. 1989a. J Morphol 199:363-378; Burke. 1989b. Fortschr Zool 35:206-209). Although the CR is thought to mediate the initiation and outgrowth of the carapace, the mechanisms of shell development have not been studied on the molecular level. Here, we present data suggesting that carapace formation is initiated by co-opting genes that had other functions in the ancestral embryo, specifically those of limb outgrowth. However, there is divergence in the signaling repertoire from that involved in limb initiation and outgrowth. In situ hybridizations with antisense riboprobes derived from Trionyx spiniferous fibroblast growth factor-10 (tfgf10) and Trachemys scripta (T. scripta) fibroblast-growth factor 8 (tfgf8) cDNAs were performed on sections of early T. scripta embryos (< 30 days). Expression of tfgf10 was localized to the mesenchyme subjacent to the ectoderm of the CR. In the chick limb bud, FGF10 is known to be expressed in the early limb-forming mesenchyme and is capable of inducing FGF8 in the AER to initiate the outgrowth of the limb bud. Although the expression of tfgf8 was found in the AER of the developing turtle limb, it was not seen in the CR. Thus, the initiation of the carapace is in agreement with FGF10 expression in the CR, but FGF8 does not appear to have a role in mediating early carapace outgrowth.


Assuntos
Evolução Biológica , Desenvolvimento Ósseo/genética , Fatores de Crescimento de Fibroblastos/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Tartarugas/genética , Animais , Sequência de Bases , Desenvolvimento Embrionário , Fatores de Crescimento de Fibroblastos/farmacologia , Hibridização In Situ , Dados de Sequência Molecular , Tartarugas/anatomia & histologia , Tartarugas/crescimento & desenvolvimento
12.
Arch Environ Contam Toxicol ; 40(3): 303-10, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11443359

RESUMO

Constructed wetlands are built because they can act as sinks for many pollutants, thereby protecting the water quality of downstream ecosystems. The treatment performance is generally assessed using mass balance calculations. Along with the mass balance approach, we compared the metal content of populations of a common pond snail (Helisoma trivolvis Say) collected upstream and downstream of a 3-year-old constructed wetland. Snails were collected in early May, June, and August 1998. At the same time, water samples for particulate and dissolved metals were taken every 3 days for the duration of the experiment. Overall, the wetland retained most dissolved metals, including Fe, Mn, Cu, Zn, Ni, and Pb, but released dissolved As. However, the wetland released particulate Fe and Mn. With the exception of Zn, the metal concentrations of the downstream snails were on average higher than those measured in the upstream population. The higher metal content of downstream snails was likely related to the significant export of particulate metals by the wetland, despite the overall retention of dissolved metals. This study points to the need for biological as well as chemical monitoring to determine the treatment efficiency and toxicological risk associated with constructed wetlands.


Assuntos
Monitoramento Ambiental/métodos , Caracois Helix/fisiologia , Metais Pesados/análise , Eliminação de Resíduos Líquidos , Animais , Arquitetura de Instituições de Saúde , Medição de Risco , Distribuição Tecidual , Poluição da Água/prevenção & controle
13.
Biochem Biophys Res Commun ; 284(3): 792-7, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11396972

RESUMO

Few genes have been isolated which display specific expression in the proximal airways. A recently identified mouse cDNA, plunc, appears to be confined to the upper airways and nasopharyngeal epithelium, and may prove a useful marker for these regions. We now report the genomic cloning and characterization of the mouse plunc gene as well as its developmental expression in the nasal and airway epithelium. We also report the novel finding that plunc is also expressed in the medullary compartment of the murine thymus. The mouse gene contains nine exons and the intron-exon boundaries are conserved with those in the human homologue. At e14.5 plunc is expressed in the nasal epithelium and several days later is seen in the thymic lobes, but not in the lining of the tracheobronchial tree. Expression in the trachea and main-stem bronchi first appears at 1--2 days after birth. Tracheobronchial expression persists at high levels throughout adulthood, as do regional areas of nasal and thymic expression. Finally, we show that the human homologue is expressed in bronchial epithelium, suggesting a transcript that is evolutionarily conserved in the mammalian airway.


Assuntos
Glicoproteínas/genética , Pulmão/embriologia , Fosfoproteínas/genética , Timo/embriologia , Animais , Brônquios/metabolismo , Glicoproteínas/metabolismo , Humanos , Hibridização In Situ , Pulmão/metabolismo , Camundongos , Nasofaringe/embriologia , Nasofaringe/metabolismo , Fosfoproteínas/metabolismo , Sítios de Splice de RNA , RNA Mensageiro/biossíntese , Mucosa Respiratória/embriologia , Mucosa Respiratória/metabolismo , Timo/metabolismo , Traqueia/embriologia , Traqueia/metabolismo
15.
Laryngoscope ; 110(1): 161-7, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10646734

RESUMO

OBJECTIVE/HYPOTHESIS: To determine if angiogenic growth factors including vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) are expressed in human paragangliomas. STUDY DESIGN: A histopathologic and molecular examination of paraganglioma specimens obtained from surgical cases or retrieved from the Pathology Department of the Massachusetts Eye and Ear Infirmary. METHODS: Fresh tumor or archival, paraffin-embedded paraganglioma specimens were analyzed by immunohistochemistry, Western blotting, and ELISA. RESULTS: Positive immunohistochemical staining for VEGF was observed in five of nine surgical specimens and in six of eight archival specimens (11/17, or 65%). PD-ECGF immunoreactivity was detected in four of five surgical specimens and six of eight archival specimens (10/13, or 77%). The presence of PD-ECGF was confirmed by Western blot assay and ELISA confirmed the presence of VEGF in tumor extract. CONCLUSIONS: Both VEGF and PD-ECGF are expressed in paragangliomas and may contribute to the extreme vascularity of these tumors. Key Words. Vascular endothelial growth factor, platelet-derived, endothelial cell growth factor, hypoxia, tumor vasculature.


Assuntos
Indutores da Angiogênese/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Paraganglioma Extrassuprarrenal/genética , Indutores da Angiogênese/análise , Corpos Aórticos/química , Corpos Aórticos/metabolismo , Western Blotting/métodos , Tumor do Corpo Carotídeo/química , Tumor do Corpo Carotídeo/genética , Tumor do Corpo Carotídeo/metabolismo , Fatores de Crescimento Endotelial/análise , Fatores de Crescimento Endotelial/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Tumor do Glomo Jugular/química , Tumor do Glomo Jugular/genética , Tumor do Glomo Jugular/metabolismo , Humanos , Imuno-Histoquímica , Linfocinas/análise , Linfocinas/metabolismo , Paragânglios não Cromafins/química , Paragânglios não Cromafins/metabolismo , Paraganglioma Extrassuprarrenal/química , Paraganglioma Extrassuprarrenal/metabolismo , Isoformas de Proteínas , Timidina Fosforilase/análise , Timidina Fosforilase/metabolismo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
16.
J Biol Chem ; 274(19): 13698-703, 1999 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-10224143

RESUMO

We have identified a novel gene transcript of approximately 1.1 kilobases in length that is expressed in the presumptive nasal epithelium of the mouse embryo. In situ hybridization analysis shows discrete regions of expression associated with the palate, nasal septum, and nasal conchae. This transcript is also expressed strongly in the trachea and bronchi of the adult lung. Screening of a mouse heart cDNA library yielded several overlapping clones to give a continuous sequence of 1113 bases, containing an open reading frame of 278 codons comprising the complete mRNA. No significant homologies with known genes were observed at the nucleotide level; limited amino acid homology with two salivary gland-specific proteins was noted. A search for functionally significant protein motifs revealed consensus sequences for N-glycosylation, protein kinase C and casein kinase phosphorylation, and a leucine zipper. Additionally, we observed a unique amino acid sequence pattern, consisting of the residues Gly-(Leu/Pro/Gln)-(Pro/Leu)-Leu-Pro-Leu, repeated four times near the amino-terminal portion of the protein with two amino acid residues separating the repeats. Based on these observations, we propose that we have identified a new gene, which we call plunc (for palate, lung, and nasal epithelium clone; GenBankTM accession number U69172).


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas/genética , Pulmão/metabolismo , Mucosa Nasal/metabolismo , Palato/metabolismo , Fosfoproteínas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar , Desenvolvimento Embrionário e Fetal/genética , Feminino , Camundongos , Camundongos Endogâmicos ICR , Dados de Sequência Molecular , Mucosa Nasal/embriologia , Palato/embriologia , Gravidez , Homologia de Sequência de Aminoácidos
17.
Dev Dyn ; 214(2): 101-15, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10030590

RESUMO

Vertebrate Pax genes encode a family of transcription factors that play important roles in embryonic patterning and morphogenesis. Two closely related Pax genes, Pax-1 and Pax-9, are associated with early axial and limb skeleton development. To investigate the role of these genes in cartilage formation we have examined the expression profiles of Pax-1 and Pax-9 in developing chick limb mesenchyme in vivo and in vitro. Both transcripts are detected by reverse transcription polymerase chain reaction and Northern blotting throughout chick limb development, from the early bud stages (Hamburger-Hamilton 20-23) to fully patterned appendages (stage 30). Whole-mount in situ hybridization reveals complex, nonoverlapping expression domains of these two genes. Pax-1 transcripts first appear at the anterior proximal margin of the limb buds, while Pax-9 is expressed more distally at what will be the junction of the autopod and the zeugopod. In situ hybridization to serial sections of the girdles reveals that in the pectoral region Pax-1 is expressed proximally in condensed mesenchyme surrounding the junction of the developing scapula, humerus, and coracoid. In the pelvis, Pax-1 is expressed between the femur and the developing acetabulum and along the ventral edge of the ischium; this transcript was also found in the distal hindlimb along the posterior edge of the fibula. Pax-9 transcripts were not detected in the pectoral girdle at any stage, and only weakly in the pelvis along the ventral ischial margin. In the distal parts of both wings and legs, however, Pax-9 is strongly expressed between the anterior embryonic cartilages (e.g., distal radius or tibia) and the anterior ectodermal ridge. The expression of both genes was strongest in undifferentiated cells of precartilage condensations or at the margins of differentiated cartilages, and was absent from cartilage itself. In micromass cultures of chondrifying limb bud mesenchyme expression of Pax-1 and Pax-9 is maintained for up to 3 days in vitro, most strongly at the end of the culture period during chondrogenic differentiation. As seen in vivo, transcripts are found in loose mesenchyme cells at the outer margins of developing cartilage nodules, and are absent from differentiated chondrocytes at the nodule center. Taken together, these investigations extend previous studies of Pax-1 and Pax-9 expression in embryonic limb development while validating limb bud mesenchyme culture as an accessible experimental system for the study of Pax gene function and regulation. Our in vivo and in vitro observations are discussed with reference to 1) the relationship between somitic and limb expression of these two Pax genes, 2) what regulates this expression in different regions of the embryo, and 3) the putative cellular functions of Pax-1 and Pax-9 in embryonic skeletogenesis.


Assuntos
Desenvolvimento Ósseo/genética , Proteínas de Ligação a DNA/genética , Botões de Extremidades/crescimento & desenvolvimento , Fatores de Transcrição/genética , Animais , Elementos Antissenso (Genética) , Northern Blotting , Embrião de Galinha , Proteínas de Ligação a DNA/análise , Hibridização In Situ , Botões de Extremidades/metabolismo , Modelos Biológicos , Fator de Transcrição PAX9 , Fatores de Transcrição Box Pareados , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Distribuição Tecidual , Fatores de Transcrição/análise
18.
Biol Bull ; 193(1): 77-89, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28581849

RESUMO

We present the first in vivo measurements of intersegmental rotation in the ophiuroid arm, comparing lateral bending performance in seven epifaunal species from Discovery Bay, Jamaica. The species studied include suspension-feeders, deposit-feeders, and scavengers, and also represent two major types of vertebral ossicle morphology. Animals were photographed with strobe illumination, and the angular deflections between arm segments were recorded. Despite considerable variation in vertebral morphology, ecology, and behavior, Discovery Bay ophiuroids show similar, overlapping distributions of maximal intersegmental rotations. Although interspecific differences in mean lateral flexibility can be statistically significant, absolute differences among species are small and of unknown functional significance. These quantitative data challenge long-standing assumptions about how the ophiuroid vertebral skeleton affects intersegmental flexibility, and how intersegmental flexibility per se affects an ophiuroid's ecological style or success.

19.
Tissue Cell ; 27(5): 539-43, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18621311

RESUMO

Local areas of roughened skeletal calcite are reported from the otherwise smooth, imperforate skeletal articulations of the ophiuroid vertebral ossicle (Echinodermata: Ophiuroidea). Complementary patterns of roughness on both proximal and distal articulating surfaces suggest local points of wear between adjacent ossicles, presumably caused by repeated rotation of the intervertebral joint. This surface feature is discussed with respect to its possible origin (mechanical action, resorption of skeletal material, experimental artifact) and the functional morphology of the ophiuroid arm skeleton.

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