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1.
Org Lett ; 22(10): 3969-3973, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32342693

RESUMO

The replacement of toxic solvents with greener alternatives in Heck-Cassar-Sonogashira (HCS) cross-couplings was investigated. The fine-tuning of the HCS protocol allowed to achieve complete conversions and high speed under mild conditions. N-Hydroxyethylpyrrolidone (HEP) gave the best results. Moreover, the methodology was successfully applied to the synthesis of an intermediate of the anticancer drug Erlotinib, demonstrating the versatility of the new green protocol.

2.
HLA ; 2018 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-29577660

RESUMO

The novel ERAP1 allelic variant is a missense polymorphism leading to the Arg53Pro substitution.

3.
RSC Adv ; 8(18): 9723-9730, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-35540807

RESUMO

A new metal-free protocol for promoting oxidation of amines in aqueous-organic medium was developed. NaIO4 and TEMPO as the catalyst emerged as the most efficient and selective system for oxidation of differently substituted benzyl amines to the corresponding benzaldehydes without overoxidation. Unsymmetrical secondary amines underwent selective oxidation only at the benzylic position thus realising an oxidative deprotection of a benzylic group with an easy amine recovery.

4.
Sci Rep ; 7(1): 17723, 2017 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-29255232

RESUMO

In autumn 2013, the presence of Xylella fastidiosa, a xylem-limited Gram-negative bacterium, was detected in olive stands of an area of the Ionian coast of the Salento peninsula (Apulia, southern Italy), that were severely affected by a disease denoted olive quick decline syndrome (OQDS). Studies were carried out for determining the involvement of this bacterium in the genesis of OQDS and of the leaf scorching shown by a number of naturally infected plants other than olive. Isolation in axenic culture was attempted and assays were carried out for determining its pathogenicity to olive, oleander and myrtle-leaf milkwort. The bacterium was readily detected by quantitative polymerase chain reaction (qPCR) in all diseased olive trees sampled in different and geographically separated infection foci, and culturing of 51 isolates, each from a distinct OQDS focus, was accomplished. Needle-inoculation experiments under different environmental conditions proved that the Salentinian isolate De Donno belonging to the subspecies pauca is able to multiply and systemically invade artificially inoculated hosts, reproducing symptoms observed in the field. Bacterial colonization occurred in prick-inoculated olives of all tested cultivars. However, the severity of and timing of symptoms appearance differed with the cultivar, confirming their differential reaction.


Assuntos
Olea/microbiologia , Doenças das Plantas/microbiologia , Xylella/isolamento & purificação , Itália , Olea/metabolismo , Síndrome , Virulência , Xylella/metabolismo , Xylella/patogenicidade
5.
J Anim Sci ; 95(9): 3873-3884, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28991993

RESUMO

The presence of lesions on the pig carcass is an indicator of poor animal welfare and has economic impact as it downgrades the carcass value. The assessment of the age of lesions on the carcass may help identify risk factors and ultimately prevent their occurrence. The aim of this study was to assess the age of lesions on pig carcasses through spectrophotometric color evaluation and to relate the results with gene expression and histological and histochemical parameters. A total of 96 barrows were mixed 4 times over 3 d before slaughter and 80 lesions were selected after skin lesion observations to define 4 age categories: < 7 h (T1), 7-25 h (T2), 25-30 h (T3), and 49-54 h (T4). A nonlesioned skin area was used as a control. At slaughter, 3 biopsies per lesion and control skin were taken immediately after bleeding for analyses of gene expression (, , , , , , , , , ), skin histological characteristics (inflammation, erosion or ulceration, and necrosis), and enzyme activity (alkaline phosphatase and adenosine triphosphatase). The number of lesions was counted on each carcass, and the color was assessed visually by a pictorial chart and instrumentally through a spectrophotometer. Delta values (Δ) were calculated as the difference between the value of the lesion and the value of the control for all measures, except for the histological analysis. Results indicated that visual color observation was not sufficiently accurate to discriminate lesions by time of infliction ( > 0.10), while the spectrophotometer ΔL* and Δa* values variation allowed the identification of < 7 h or > 25 h old lesions ( < 0.05). Similarly, the expression of , , , , and genes was higher ( < 0.05) in < 7 h old lesions, while gene expression was higher ( < 0.05) in < 25 h old lesions. As for the histological analysis, the severity of inflammation was correlated with the age of the lesion (lower score in < 7 h old lesions and higher score in > 25 h old lesions; < 0.05). To conclude, the spectrophotometric color assessment of the carcass lesions at slaughter appears to be a reliable method to discriminate between fresh and older lesions on the carcass at the abattoir.


Assuntos
Bem-Estar do Animal , Carne Vermelha/normas , Dermatopatias/veterinária , Espectrofotometria/veterinária , Doenças dos Suínos/patologia , Fatores Etários , Animais , Cor , Expressão Gênica , Histocitoquímica/veterinária , Masculino , Análise Multivariada , Pele/patologia , Dermatopatias/patologia , Suínos
6.
Eur J Surg Oncol ; 43(11): 2012-2020, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28912071

RESUMO

BACKGROUND: It is controversial whether sentinel node biopsy (SNB) is adequate in breast cancer patients who become cN0 after primary chemotherapy. To address this we retrospectively compared outcomes in T2 cases given primary chemotherapy, comparing those given axillary dissection (AD) with those given SNB but no AD if sentinel nodes were clinically negative post-chemotherapy. METHODS: We examined overall survival (OS), disease-free survival (DFS), and axillary failure in 317 consecutive cT2 cN0/1 patients given primary chemotherapy followed by quadrantectomy/mastectomy, between January 2002 and December 2007. The approach to the axilla changed over time allowing division into three groups: 101 (31.9%) given upfront AD; 139 (43.8%) given SNB + AD; and 77 (24.3%) given SNB only because the SNs were negative. RESULTS: After median follow-ups of 92 (AD), 99 (SNB + AD) and 72 months (SNB-only), OS (p = 0.131) and DFS (p = 0.087) did not differ between the 3 groups, or between SNB-only and the ypN1 and ypN0 subgroups of SNB + AD, or between the cN0 and cN1 subgroups (before chemotherapy) of the SNB-only group. No SNB-only patient had axillary failure. OS (p = 0.004) and DFS (p = 0.002) were better in patients with complete response than those with partial response or stable/progressive disease. CONCLUSIONS: SNB is adequate in T2 patients who are cN0 after primary chemotherapy, irrespective of axillary status before. Better outcomes after complete pathological remission confirm the prognostic importance of response to primary chemotherapy, and suggest that all T2 patients should receive primary chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Biópsia de Linfonodo Sentinela , Adulto , Axila , Feminino , Humanos , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/patologia , Linfocintigrafia , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Retrospectivos , Taxa de Sobrevida
7.
Clin Microbiol Infect ; 23(5): 335.e1-335.e5, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28259548

RESUMO

OBJECTIVE: This multicentre cross-sectional study aims to estimate the prevalence of five neglected tropical diseases (Chagas disease, filariasis, schistosomiasis, strongyloidiasis and toxocariasis) among immigrants accessing health care facilities in five Italian cities (Bologna, Brescia, Florence, Rome, Verona). METHODS: Individuals underwent a different set of serological tests, according to country of origin and presence of eosinophilia. Seropositive patients were treated and further followed up. RESULTS: A total of 930 adult immigrants were enrolled: 477 men (51.3%), 445 women (47.9%), eight transgender (0.8%); median age was 37.81 years (range 18-80 years). Most of them had come from the African continent (405/930, 43.5%), the rest from East Europe, South America and Asia, and 9.6% (89/930) were diagnosed with at least one of the infections under study. Seroprevalence of each specific infection varied from 3.9% (7/180) for Chagas disease to 9.7% (11/113) for toxocariasis. Seropositive people were more likely to be 35-40 years old and male, and to come from South East Asia, sub-Saharan Africa or South America. CONCLUSIONS: The results of our study confirm that neglected tropical diseases represent a substantial health problem among immigrants and highlight the need to address this emerging public health issue.


Assuntos
Emigrantes e Imigrantes , Doenças Negligenciadas/epidemiologia , Doenças Parasitárias/epidemiologia , Adolescente , Adulto , África Subsaariana/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Ásia/epidemiologia , Estudos Transversais , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Doenças Negligenciadas/diagnóstico , Doenças Negligenciadas/parasitologia , Doenças Parasitárias/diagnóstico , Saúde Pública , Estudos Soroepidemiológicos , Fatores Socioeconômicos , América do Sul/epidemiologia , Adulto Jovem
8.
J Anim Sci ; 93(2): 758-66, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26020756

RESUMO

To attain a good level of animal welfare, pigs require a sufficient environmental illumination. Therefore, minimum levels for light duration and light intensity have been set up by the European legislation (Directive 2008/120). An experimental trial was designed to determine whether an increased duration of the photophase (up to 16 h of light per day) could modify the behavior, productive parameters, and meat and ham quality of Italian heavy pigs. Forty crossbred (Large White × Landrace) castrated males pigs (26 kg initial average BW) intended for Protected Designation of Origin (according to European Union Regulation 1151/2012, ) dry-cured ham production were raised according to Parma ham production rules up to the weight of 160 kg. Pigs were homogeneously allotted to 2 experimental groups, each comprising 20 pigs. The short photoperiod (SP) group received the minimum mandatory number of hours of light per day (corresponding to 8 h/d), whereas the long photoperiod (LP) group was subjected 16 h of light per day during the whole production cycle. Light intensity was maintained at 40 lux (i.e., the minimum mandatory level) for both the experimental groups. Growth and slaughtering parameters, carcass traits, fatty acid composition, meat and dry-cured ham quality, and animal behavior were assessed. Pigs in the LP group showed a greater live weight and carcass weight compared to the SP group ( = 0.005 and = 0.007, respectively). Similarly, hams obtained from the LP group were significantly heavier and their weight losses during the dry-curing period were reduced ( < 0.01) when compared to the SP group. No significant differences were detected between the experimental groups as concerns meat and ham quality or fatty acid composition of the subcutaneous fat. Pigs in the LP group spent more time resting and less time pseudo-rooting ( < 0.01). Our results indicate that, given an appropriate dark period for animal rest, an increased duration of the photoperiod, even at the lower mandatory light intensity level, can favorably affect growth parameters of heavy pigs without any negative effect on animal behavior, carcass traits, or meat or long-cured ham quality. Therefore, rearing pigs in semidarkness should be considered as a baseless practice, contrary to animal welfare.


Assuntos
Comportamento Animal/fisiologia , Peso Corporal/fisiologia , Indústria Alimentícia/normas , Carne/normas , Fotoperíodo , Suínos/crescimento & desenvolvimento , Suínos/fisiologia , Bem-Estar do Animal , Animais , Composição Corporal/fisiologia , Ácidos Graxos/análise , Masculino , Fenótipo , Controle de Qualidade , Descanso/fisiologia , Gordura Subcutânea/química , Fatores de Tempo
9.
Virus Genes ; 50(1): 165-71, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25315631

RESUMO

The complete genome of a Tomato black ring virus isolate (TBRV-Mirs) (RNA1, 7,366 nt and RNA2, 4,640 nt) and the RNA2 sequences (4,437; 4,445; and 4,442 nts) of three Grapevine chrome mosaic virus isolates (GCMV-H6, -H15, and -H27) were determined. All RNAs contained a single open reading frame encoding polyproteins of 254 kDa (p1) and 149 kDa (p2) for TBRV-Mirs RNA1 and RNA2, respectively, and 146 kDa for GCMV RNA2. p1 of TBRV-Mirs showed the highest identity with TBRV-MJ (94 %), Beet ringspot virus (BRSV, 82 %), and Grapevine Anatolian ringspot virus (GARSV, 66 %), while p2 showed the highest identity with TBRV isolates MJ (89 %) and ED (85 %), followed by BRSV (65 %), GCMV (58 %), and GARSV (57 %). The amino acid identity of RNA2 sequences of four GCMV isolates (three from this study and one from GenBank) ranged from 91 to 98 %, the homing protein being the most variable. The RDP3 program predicted putative intra-species recombination events for GCMV-H6 and recognized GCMV as a putative inter-species recombinant between GARSV and TBRV. In both cases, the recombination events were at the movement protein level.


Assuntos
Genoma Viral , Nepovirus/genética , Nepovirus/isolamento & purificação , RNA Viral/genética , Análise de Sequência de DNA , Análise por Conglomerados , Solanum lycopersicum/virologia , Dados de Sequência Molecular , Peso Molecular , Nepovirus/classificação , Fases de Leitura Aberta , Filogenia , Poliproteínas/química , Poliproteínas/genética , Recombinação Genética , Homologia de Sequência de Aminoácidos , Vitis/virologia
10.
Eur J Surg Oncol ; 40(7): 805-12, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24768443

RESUMO

BACKGROUND: Our randomized trial found no survival advantage for axillary dissection (AD) compared observation only (no AD) in older patients with early breast cancer and a clinically negative axilla, indicating that AD is unnecessary. We compared characteristics and outcomes in out-trial patients with those in trial patients to provide indications as to whether AD can be safely omitted outside the trial setting. METHODS: The trial started in 1996, recruiting 238 patients age 65-80 years with cT1cN0 breast cancer, randomized to conservative surgery with or without AD. Over the recruitment period, 109 eligible patients who refused to participate in the trial, also received conservative breast surgery with or without AD depending on patient preference/surgeon opinion. Trial and out-trial patients received conventionally-fractioned whole breast radiation and tamoxifen for five years. Endpoints were breast cancer mortality, overall survival, and cumulative incidence of axillary disease in patients not receiving AD. RESULTS: After 15 years of follow-up, breast cancer mortality and overall survival did not differ between the AD and no AD arms, in either the trial or out-trial cohorts. The 15-year cumulative incidence of axillary relapse was 6% in the no AD arm of the trial group, and zero in the no AD arm of the out-trial group. CONCLUSIONS: Outside the trial setting, older patients with T1N0 breast cancer can be safely treated by conservative surgery, postoperative radiotherapy and tamoxifen for five years (if ER-positive). Axillary surgery is appropriate only for the small proportion of patients who develop overt axillary disease during follow-up.


Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Excisão de Linfonodo/métodos , Linfonodos/patologia , Mastectomia Segmentar/métodos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Axila/cirurgia , Biópsia por Agulha , Neoplasias da Mama/mortalidade , Quimioterapia Adjuvante , Estudos de Coortes , Intervalos de Confiança , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Feminino , Avaliação Geriátrica , Humanos , Imuno-Histoquímica , Linfonodos/cirurgia , Invasividade Neoplásica/patologia , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Radioterapia Adjuvante , Medição de Risco , Análise de Sobrevida , Tamoxifeno/administração & dosagem , Fatores de Tempo
11.
Animal ; 8(5): 810-6, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24739353

RESUMO

Pigs are increasingly used in medical research as transgenic laboratory animals; however, little knowledge is presently available concerning their welfare assessment. The aim of the present study was to investigate some welfare-related parameters of transgenic pigs intended for xenotrasplantation (human decay-accelerating factor (hDAF)) when compared with their conventional (i.e. not transgenic) close relatives (full sibs and half sibs). A total of 14 Large White female transgenic pigs and 10 female non-transgenic (conventional) pigs from four litters were used. All pigs were from the same conventional boar, donor of the semen treated for sperm-mediated gene transfer. During the experiment, BW ranged from 50 to about 80 kg and pigs were weighed at the beginning and at the end of the experiment. Animals were subjected to a set of behavioural tests: a human approach test (HAT), a novel object test (NOT) and an open-door test (ODT). Food preferences were tested through the offer of different foods (banana, apple, carrot, cracker and lemon). During a 4-day period, pigs were diurnally videotaped to study the prevalence of the different behaviours and social interactions (aggressive and non-aggressive interactions). At the end of the trial, cortisol level had been assessed on bristles. No significant differences (P>0.05) were observed between hDAF transgenic and conventional pigs with respect to growth traits, reactivity towards unexpected situations (HAT, NOT, ODT), food preferences, main behavioural traits, social interactions and hair cortisol.


Assuntos
Bem-Estar do Animal , Animais Geneticamente Modificados/genética , Antígenos CD55/genética , Suínos/genética , Animais , Animais Geneticamente Modificados/fisiologia , Comportamento Animal , Feminino , Preferências Alimentares , Expressão Gênica , Cabelo/química , Humanos , Hidrocortisona/análise , Masculino , Comportamento Social , Espermatozoides/fisiologia , Suínos/fisiologia , Temperatura , Transgenes , Transplante Heterólogo/veterinária
12.
J Appl Microbiol ; 115(3): 786-95, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23742127

RESUMO

AIMS: The aim of this study was to apply the flow cytometry to Lactobacillus sakei strains, selected as potential autochthonous starters, to investigate dynamics and physiological heterogeneity of microbial behaviour under different stress conditions. METHODS AND RESULTS: A simultaneous nucleic acid double-staining assay was applied to discriminate cell populations in different physiological states after exposure to heat (50 and 55°C) and acid (pH 2·5 and 3·0) stresses. Alive cells with intact membranes, damaged cells still alive but with injured membranes, so with even a recovery ability, and dead cells with a permanent membrane damage were differentiated with a significant increase in damaged cells after stronger stress treatments. CONCLUSIONS: The existence and characteristics of subpopulations displaying heterogeneity in particular conditions are highly relevant, because specific subpopulations may show improved survival, changes and dynamics under stress conditions. SIGNIFICANCE AND IMPACT OF STUDY: This assay has potential for physiological research on lactic acid bacteria and for application in the food industry. The assessment of intermediate physiological states in Lb. sakei strains with recovery possibility could be an important criterion for application of potential starter cultures. Application of flow cytometry and characterization of sorted subpopulations may contribute to further understanding of diversity and heterogeneity in physiology of bacterial populations.


Assuntos
Citometria de Fluxo/métodos , Lactobacillus/crescimento & desenvolvimento , Estresse Fisiológico , Corantes Fluorescentes , Temperatura Alta , Lactobacillus/citologia , Lactobacillus/genética , Ácidos Nucleicos/análise , Coloração e Rotulagem
13.
J Sports Med Phys Fitness ; 53(3): 283-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23715253

RESUMO

AIM: The aim of the present study was to evaluate, in a group of semi-professional volleyball players, the function of the rotator cuff muscles with a new specific device. METHODS: We have studied 30 asymptomatic volleyball players, 15 females and 15 males, all right handed central or lateral spikers, with some specific functional tests. Every subject was evaluated by some common clinical tests to detect shoulder range of motion (ROM) and rotator cuff muscles strength in both sides. Athletes were also submitted to an isometric bilateral shoulder strength test, with a specific upper limb dynamometer (Dynatorq), in three different positions: 1) arm 0° abducted; 2) arm 90° abducted and 90° external rotation, to try to reproduce the spike gesture; 3) arm behind the thorax, as a simulation of clinical lift-off test. All clinical and instrumental data were collected in male and female groups and, in each group, comparisons between dominant and non dominant shoulders. RESULTS: Our data show in all athletes an initial postero-superior impingement with significant weakness of the subscapularis muscle in the dominant shoulder. CONCLUSION: In all overhead athletes, and in particular in volleyball spikers, a pre-clinical diagnosis of lack of strength of the subscapularis muscle in the dominant side, before the occurrence of pain or discomfort signs, could be an important diagnostic aspect to avoid or delay the back-retraction of the joint capsule of the shoulder.


Assuntos
Contração Isométrica/fisiologia , Manguito Rotador/fisiologia , Voleibol/fisiologia , Adulto , Transtornos Traumáticos Cumulativos/diagnóstico , Transtornos Traumáticos Cumulativos/fisiopatologia , Diagnóstico Precoce , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Força Muscular/fisiologia , Adulto Jovem
16.
J Virol Methods ; 155(1): 72-6, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18940199

RESUMO

Little cherry, an economically important disease of cherry is caused by at least two different viruses. One of these is Little cherry virus 1 (LChV-1) for the detection of which no efficient serological tools are available, so that diagnosis is based on molecular methods. In this study, different immunization strategies for producing antibodies against the viral coat protein of LChV-1 were tried, using either purified virus preparations, or bacterially expressed protein, or a DNA vector that expressed the cloned coat protein (CP) gene in vivo. Effective induction of specific antibodies to LChV-1 CP was obtained using DNA intramuscular immunization followed by a single boost with the recombinant protein. The entire coat protein sequence was cloned in a mammalian expression vector and, after being coated by an amphiphilic non-toxic reagent was delivered into rabbit. A protein boost increased the specific immune response against the virus protein. The sensitivity of this antiserum is lower if compared with that of antisera raised conventionally against other viruses, thus it requires improvements for use for diagnostic purposes.


Assuntos
Anticorpos Antivirais/sangue , Proteínas do Capsídeo/imunologia , Closteroviridae/imunologia , DNA/administração & dosagem , Proteínas Recombinantes/administração & dosagem , Vacinas Virais/administração & dosagem , Animais , Proteínas do Capsídeo/genética , Closteroviridae/genética , Closteroviridae/isolamento & purificação , DNA/genética , DNA/imunologia , Imunização Secundária , Doenças das Plantas/virologia , Prunus/virologia , Coelhos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Vacinação , Vacinas Virais/genética , Vacinas Virais/imunologia
17.
Meat Sci ; 81(4): 678-85, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20416571

RESUMO

Objective of this study was to evaluate the performance, the quality and oxidative stability of meat, the total Se and specific selenoamino-acids content of muscle of lambs that were fed diets supplemented from different Se sources and at different levels. Forty-eight Apennine lambs 30day old (12.78±0.94kg) received, during a 63day period, a total mixed ration (TMR) which was either Se unsupplemented (Control group - background only- 0.13mg/kg Se) or supplemented with Na selenite (0.30mg/kg Se as sodium selenite) or selenium enriched yeast (0.30mg/kg and 0.45mg/kg Se as Se-yeast). Growth performance, feed to gain ratio, carcass and meat quality (pH, drip and cooking losses, colour, GSH-Px activity and chemical analysis) did not show any difference between the treatments. Meat colour and oxidative stability during 9 days of refrigerated storage were unaffected by dietary supplementation, suggesting that, at the levels of Se used in this experiment, dietary Se, even from an organic source, had limited potential for reducing lipid oxidation. Selenium supplementation raised the Se content in muscle (P<0.001) with the greatest increase when Se-yeast was fed. Although selenite increased total Se, it did not influence total or specific selenoamino-acids in this tissue. On the contrary, Se-yeast supplementation led to an increase in muscle Se-methionine content. We conclude that Se supplementation can increase significantly muscle Se levels and produce, particularly when Se-yeast is fed, a source of Se enriched meat as Se-methionine.

18.
Amino Acids ; 34(2): 333-6, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17136507

RESUMO

The synthesis of an orthogonally protected constrained analogue of dipeptide DG (Asp-Gly) is reported exploiting alkylation of a chiral lactam. The versatility of this analogue was proven by removal of t-Boc protecting group, followed by coupling under homogeneous conditions with t-Boc-Arg(Z(2))-Gly, to give a conformationally restricted analogue of RGDG tetrapeptide.


Assuntos
Dipeptídeos/síntese química , Biomimética
19.
J Gen Virol ; 87(Pt 8): 2387-2395, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16847135

RESUMO

Higher plants use post-transcriptional gene silencing (PTGS), an RNA-degradation system, as a defence mechanism against viral infections. To counteract this, plant viruses encode and express PTGS suppressor proteins. Four of the five proteins encoded by the Grapevine virus A (GVA) genome were screened using a green fluorescent protein (GFP)-based transient expression assay, and the expression product of ORF5 (protein p10) was identified as a suppressor of silencing. ORF5 p10 suppressed local and systemic silencing induced by a transiently expressed single-stranded sense RNA. This protein was active towards both a transgene and exogenous GFP mRNAs. Ectopic expression of GVA-ORF5 by a Potato virus X vector enhanced symptom severity. The findings that p10 markedly reduces the levels of small interfering RNAs (siRNAs) and that the recombinant protein is able to bind single-stranded and double-stranded forms of siRNAs and microRNAs, suggest the existence of a potential mechanism of suppression based on RNA sequestering.


Assuntos
Vírus de Plantas/genética , Interferência de RNA , Vírus de RNA/genética , Proteínas Virais/fisiologia , Expressão Gênica , Genes Reporter , Vetores Genéticos , Proteínas de Fluorescência Verde/análise , Doenças das Plantas/virologia , Vírus de Plantas/patogenicidade , Potexvirus/genética , Ligação Proteica , Vírus de RNA/patogenicidade , RNA Interferente Pequeno/metabolismo , Nicotiana/virologia , Transfecção
20.
Arch Virol ; 151(10): 1973-83, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16699830

RESUMO

A full-length cDNA clone of olive latent virus 1 (OLV-1), a member of the genus Necrovirus, family Tombusviridae, was subjected to site-directed mutagenesis, and coat protein gene mutants were constructed. A mutant clone, denoted Delta3297, was obtained by deleting the nucleotide in position 3297, thus inducing a frameshift and replacing the last 49 amino acids of the viral coat protein (CP) by a shorter sequence of 39 amino acids. This mutant was viable, stable, able to synthesize a smaller CP, and able to give rise to the formation of apparently intact virus particles. Cell-to-cell movement of Delta3297 in Nicotiana benthamiana leaves was not affected, but, contrary to wild type OLV-1, it failed to spread systemically. These results indicate that virion formation is necessary but not sufficient for long-distance movement for OLV-1 and highlights the role of the CP carboxy-terminal domain in systemic infection.


Assuntos
Proteínas do Capsídeo/fisiologia , Doenças das Plantas/virologia , Infecções por Vírus de RNA/virologia , Tombusviridae/química , Sequência de Aminoácidos , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Mutação da Fase de Leitura , Locomoção , Dados de Sequência Molecular , Mutação Puntual , Estrutura Terciária de Proteína/fisiologia , Nicotiana , Tombusviridae/patogenicidade , Tombusviridae/fisiologia , Virulência
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