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1.
PLoS One ; 18(6): e0286022, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37267259

RESUMO

The responsible behaviour of consumers that purchase green computers is a form of sustainable consumption, as green computers use less energy resulting in less CO2 emissions and the use of fewer toxic metals and materials during their production. The research question is how to encourage such behaviour. Although prior research has provided some answers by investigating the antecedents of the behaviour, it has done so through a piecemeal approach from the angles of the theory of planned behaviour (TPB), the value-belief-norm (VBN) theory, and habits. The present research aims to investigate the antecedents of the responsible acquisition of computers behaviour (RACB) among Malaysian consumers by integrating the TPB and the VBN theory with the habits variable. Hypotheses and a research framework were developed based on these theories and a survey questionnaire was used to collect information on the green computer purchase behaviour of computer owners aged 17 and over in Malaysia. A total of 1,000 usable surveys were completed and structural equation modelling was used to analyse the data collected. The findings reveal that the TPB, the VBN theory, and the habits variable can be integrated to explain RACB, which is formed when biospheric values trigger subjective norms that subsequently result in the formation of habits that lead to intentions of acquiring green computers and RACB. The study's findings show that although personal norms do not affect RACB, subjective norms affect ascriptions of responsibility, personal norms, and RACB. The findings provide insights to policymakers, NGOs, manufacturers, and marketers that can assist them in designing strategies for the effective promotion of RACB.


Assuntos
Comportamento Social , Teoria do Comportamento Planejado , Humanos , Intenção , Inquéritos e Questionários , Hábitos
2.
Surg Neurol Int ; 8: 244, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29119042

RESUMO

BACKGROUND: Extradural hemangiomas are rare, have varied and challenging clinical presentations, and require special considerations from the management point of view. CASE DESCRIPTION: A 70-year-old female presented with back pain that was ultimately attributed to a thoracolumbar extra-dural "dumbbell" hemangioma. Following surgical resection, the patient did well. CONCLUSION: Extradural hemangiomas may present as spinal extradural soft tissue masses that must be differentiated from dumbbell neurofibroma.

3.
Asia Pac J Clin Oncol ; 13(6): 372-378, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28371190

RESUMO

AIM: For early-stage breast cancer, four cycles of docetaxel and cyclophosphamide (TC) was proven superior to doxorubicin plus cyclophosphamide in the US Oncology 9375 trial. Given primary prophylactic antibiotics, 5% febrile neutropenia was recorded in a population comprising 75.5% Caucasians. Smaller trials and retrospective studies reviewing TC use in Asian patients did not produce similar incidence rates. This study aims to discover the variable hematological toxicities with TC use in Caucasian and Asian patients. METHODS: Breast cancer data was retrospectively reviewed for patients receiving adjuvant docetaxel 60-75 mg/m2 plus cyclophosphamide 600 mg/m2 from six countries (China, Hong Kong, Japan, Taiwan, Italy, and United States). Similar number of patients with relatively balanced baseline characteristics were chosen for analysis of hematological and nonhematological toxicities and survival data. RESULTS: From March 2004 to July 2013, data of 227 patients (127 Asians and 100 Caucasian) patients were analyzed for treatment-related toxicities. During the four cycles of TC, Asians had a significantly higher rate of grade ≥2 neutropenia than Caucasians (45.7% vs 6.0%; P <0.001) and significantly more grade ≥3 neutropenia events were documented (respectively 30.7% vs 4.0%, P <0.001). The prophylactic use of G-CSF was similar; 26.0% in Asians and 28.0% in Caucasian (P = 0.764). There were no differences in nonhematological toxicities. No significant difference in disease-free survival was observed between Asians and Caucasians (log-rank P = 0.910). CONCLUSIONS: Ethnic differences in toxicity profile exist between Asian and Caucasian patients given adjuvant TC. Over 30% Asians but less than 5% Caucasians experienced grade ≥3 neutropenia.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Taxoides/efeitos adversos , Povo Asiático , Neoplasias da Mama/patologia , Docetaxel , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , População Branca
4.
Appl Ergon ; 44(5): 719-29, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22841592

RESUMO

Ever since the 9/11 terrorist attack, many countries are considering the use of smart national identity card (SNIC) which has the ability to identify terrorists due to its biometric verification function. However, there are many ergonomics issues in the use of SNIC, e.g. card credibility. This research presents a case study survey of Malaysian users. Although most citizens (>96%) own MyKad (Malaysia SNIC), many do not carry it around and use its applications. This defeats one of its main purposes, i.e. combating terrorism. Thus, the research investigates ergonomics issues affecting the citizens' Intention to Use (ITU) MyKad for homeland security by using an extended technology acceptance model. Five hundred questionnaires were collected and analysed using structural equation modelling. Results show that perceived credibility and performance expectancy are the key issues. The findings provide many countries with insights into methods of addressing ergonomics issues and increasing adoption of SNIC for homeland security.


Assuntos
Identificação Biométrica/instrumentação , Ergonomia/psicologia , Medidas de Segurança , Políticas de Controle Social , Adolescente , Adulto , Ansiedade/psicologia , Atitude , Bases de Dados Factuais , Feminino , Humanos , Intenção , Aplicação da Lei , Malásia , Masculino , Pessoa de Meia-Idade , Opinião Pública , Desejabilidade Social , Facilitação Social , Tecnologia , Terrorismo/prevenção & controle , Confiança , Adulto Jovem
6.
Int J Biol Markers ; 27(4): e295-304, 2012 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-23280127

RESUMO

Tumor-stromal interactions involve continuous crosstalk and interactions among different cell types and play pivotal roles in tumorigenesis, tumor development, disease progression, subsequent metastasis, and also tumor response to therapeutic agents. Tumor infiltrating lymphocytes (TILs) are important components of these tumor-stromal interactions. Specific TIL subtypes are known to be involved in the clinical course of individual patients. However, the status of TILs following endocrine therapy has not been studied in breast cancer patients. We evaluated the alterations of TIL subtypes in a cohort of East Asian patients with estrogen receptor-positive breast cancer during the course of neoadjuvant steroidal aromatase inhibitor (AI) therapy, using double immunohistochemical staining of CD8+ and T regulatory cells (Treg) or Foxp3+, yielding the CD8+/Treg ratio in individual patients. Changes in CD8+/Treg ratio before and after therapy were then correlated with pathobiological responses of individual patients based upon alterations of the Ki-67 labeling index (LI). A significant increase in the CD8+/Treg ratio was detected in responders (p=0.028) but not in non-responders, which may reflect the dynamic process in which the host immune response to tumor antigens changed in consequence of an interaction between tumor and stromal cells in its microenvironment following estrogen depletion caused by the AI. The CD8+/Treg ratio in breast cancer tissue can be a potential surrogate marker in surgical pathology specimens for predicting responses to neoadjuvant endocrine therapy, not only incorporating features of carcinoma cells as in Ki-67 LI but also those of adjacent stromal cells in the tumor microenvironment, especially in the early stage of treatment prior to any detectable clinical and/or histopathological changes.


Assuntos
Androstadienos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/imunologia , Fatores de Transcrição Forkhead/imunologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Receptores de Estrogênio/biossíntese , Antineoplásicos/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Biomarcadores Tumorais/imunologia , Neoplasias da Mama/patologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Ensaios Clínicos como Assunto , Feminino , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/genética , Humanos , Imuno-Histoquímica , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/patologia , Linfócitos do Interstício Tumoral/patologia , Terapia Neoadjuvante , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia
7.
Am J Physiol Gastrointest Liver Physiol ; 302(1): G105-15, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21921286

RESUMO

SAMP1/YitFcs mice serve as a model of Crohn's disease, and we have used them to assess gastritis. Gastritis was compared in SAMP1/YitFcs, AKR, and C57BL/6 mice by histology, immunohistochemistry, and flow cytometry. Gastric acid secretion was measured in ligated stomachs, while anti-parietal cell antibodies were assayed by immunofluorescence and enzyme-linked immunosorbent spot assay. SAMP1/YitFcs mice display a corpus-dominant, chronic gastritis with multifocal aggregates of mononuclear cells consisting of T and B lymphocytes. Relatively few aggregates were observed elsewhere in the stomach. The infiltrates in the oxyntic mucosa were associated with the loss of parietal cell mass. AKR mice, the founder strain of the SAMP1/YitFcs, also have gastritis, although they do not develop ileitis. Genetic studies using SAMP1/YitFcs-C57BL/6 congenic mice showed that the genetic regions regulating ileitis had comparable effects on gastritis. The majority of the cells in the aggregates expressed the T cell marker CD3 or the B cell marker B220. Adoptive transfer of SAMP1/YitFcs CD4(+) T helper cells, with or without B cells, into immunodeficient recipients induced a pangastritis and duodenitis. SAMP1/YitFcs and AKR mice manifest hypochlorhydria and anti-parietal cell antibodies. These data suggest that common genetic factors controlling gastroenteric disease in SAMP1/YitFcs mice regulate distinct pathogenic mechanisms causing inflammation in separate sites within the digestive tract.


Assuntos
Acloridria/imunologia , Doenças Autoimunes/imunologia , Gastrite/imunologia , Ileíte/imunologia , Acloridria/genética , Acloridria/patologia , Transferência Adotiva , Animais , Autoanticorpos/análise , Autoanticorpos/imunologia , Doenças Autoimunes/genética , Doenças Autoimunes/patologia , Linfócitos B/imunologia , Linfócitos B/patologia , Complexo CD3/análise , Complexo CD3/imunologia , Feminino , Ácido Gástrico/metabolismo , Gastrite/genética , Gastrite/patologia , Ileíte/genética , Ileíte/patologia , Antígenos Comuns de Leucócito/análise , Antígenos Comuns de Leucócito/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/imunologia , Linfócitos T/patologia , Linfócitos T Auxiliares-Indutores/imunologia
8.
Vet Microbiol ; 135(3-4): 368-73, 2009 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-18977620

RESUMO

To date information on rabbit haemorrhagic disease virus (RHDV) in Spain and Portugal has been scarce, although the disease is endemic and continues to have a considerable impact on species conservation and hunting industry. We analysed RHDVs obtained between 1994 and 2007 at different geographic locations in Portugal (40 samples), Spain (3 samples) and France (4 samples) from wild European rabbits (Oryctolagus cuniculus) that succumbed to the disease. Phylogenetic analyses based on partial VP60 gene sequences allowed a grouping of these RHDVs into three groups, termed "Iberian" Groups IB1, IB2 and IB3. Interestingly, these three Iberian groups clustered separately, though not far from earlier RHDVs of Genogroup 1 (containing e.g., strain "AST89"), but clearly distinct from globally described RHDV strains of Genogroups 2-6. This result, supported by a bootstrap value of 76%, gives rise to the hypothesis that the virus evolved independently since its introduction to wild rabbit populations on the Iberian Peninsula, with the Pyrenees acting as a natural barrier to rabbit and hence to virus dispersal. No differences were observed in RHDV sequences obtained from geographic regions where the rabbit subspecies O. c. algirus prevails compared with those obtained from O. c. cuniculus.


Assuntos
Infecções por Caliciviridae/veterinária , Vírus da Doença Hemorrágica de Coelhos/genética , Coelhos/virologia , Substituição de Aminoácidos , Animais , Infecções por Caliciviridae/epidemiologia , DNA Complementar/genética , Evolução Molecular , França , Vírus da Doença Hemorrágica de Coelhos/classificação , Fígado/virologia , Filogenia , Portugal/epidemiologia , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Virais/química , Proteínas Virais/genética
9.
J Virol ; 83(5): 2386-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19109386

RESUMO

Lentiviruses are causal agents of severe pathologies of a variety of mammals, including cattle and humans (e.g., AIDS and different types of lymphoma). While endogenous forms of lentivirus do not occur in these species, A. Katzourakis and coworkers (A. Katzourakis, M. Tristem, O. G. Pybus, and R. J. Gifford, Proc. Natl. Acad. Sci. USA 104:6261-6265, 2007) recently reported the presence in the genome of the European rabbit (Oryctolagus cuniculus) of multiple sequences defining a lentiviral subgroup elegantly referred to as RELIK (rabbit endogenous lentivirus type K). Sequence comparisons indicated that the RELIK ancestor may have integrated into the rabbit lineage more than 7 million years ago. We have substantiated this by producing sequence data certifying the sharing of RELIK sequences among leporid lineages that diverged some 12 million years ago.


Assuntos
Retrovirus Endógenos/genética , Evolução Molecular , Lagomorpha/virologia , Lentivirus/genética , Animais , Produtos do Gene gag/genética , Genes Virais , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
10.
Virus Res ; 137(2): 253-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18761043

RESUMO

Mutations were analysed in the major capsid protein VP60 of the rabbit haemorrhagic disease virus (RHDV), a calicivirus responsible for high mortality rates in both wild and domestic European rabbits (Oryctolagus cuniculus). Likelihood of positive selection was estimated using the PAML software applied to 43 non-identical complete sequences of the major capsid protein. Three codons showed signs of positive selection (with posterior probabilities over 95%), one of them is located in the region containing the major antigenic determinants (region E). The presence of positively selected codons (PSCs) in other regions may suggest the existence of other antigenic regions on the major capsid protein that stimulate protective immune responses. At all the 3 PSCs, variation contributes to putative N-glycosylation sites of the protein. An N-glycosylation site is deleted in the non-pathogenic strain RCV. Some of the substitutions at PSCs may alter the polarity and the charge of the protein with possible implications in the protein structure and host interaction. The detection of PSCs should allow a better understanding of the interaction between RHDV and the rabbit immune system.


Assuntos
Infecções por Caliciviridae/veterinária , Proteínas do Capsídeo/genética , Vírus da Doença Hemorrágica de Coelhos/genética , Coelhos , Seleção Genética , Animais , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/metabolismo , Códon , Glicosilação , Vírus da Doença Hemorrágica de Coelhos/metabolismo , Dados de Sequência Molecular , Coelhos/virologia
11.
Arch Virol ; 153(2): 329-35, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18193156

RESUMO

Rabbit haemorrhagic disease (RHD) is a highly fatal disease caused by a virus of the family Caliciviridae. Whereas recombination is well documented in other members of this family, the extent of recombination has so far not been studied in RHDV. To reach a better evaluation of the possible role of recombination in the evolution of RHDV virulence, we have searched for recombination events in RHDV by analysing 43 complete sequences of the major capsid gene VP60. Phylogenetic analyses revealed two well separated groups. Clear evidence for recombination was found for the Hartmannsdorf strain which shows different phylogenetic profiles depending on the region of the capsid examined.


Assuntos
Vírus da Doença Hemorrágica de Coelhos/genética , Recombinação Genética , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Vírus da Doença Hemorrágica de Coelhos/classificação , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Proteínas Estruturais Virais/química
12.
Int J Immunogenet ; 35(2): 111-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18205827

RESUMO

Chemokines receptors are transmembrane proteins that bind chemokines. Chemokines and their receptors are known to play a crucial role in the immune system and in pathogen entry. There is evidence that myxoma virus, the causative agent of myxomatosis, can use the chemokine receptor CXCR4 to infect cells. This virus causes a benign disease in its natural host, Sylvilagus, but in the European rabbit (Oryctolagus cuniculus) it causes a highly fatal and infectious disease known as myxomatosis. We have characterized the chemokine receptor CXCR4 gene in five genera of the order Lagomorpha, Ochotona (Ochotonidae), and Oryctolagus, Lepus, Bunolagus and Sylvilagus (Leporidae). In lagomorphs, the CXCR4 is highly conserved, with most of the protein diversity found at surface regions. Five amino acid replacements were observed, two in the intracellular loops, one in the transmembrane domain and two in the extracellular loops. Oryctolagus features unique amino acid changes at the intracellular domains, putting this genus apart of all other lagomorphs. Furthermore, in the 37 European rabbits analysed, which included healthy rabbits and rabbits with clinical symptoms of myxomatosis, 14 nucleotide substitutions were obtained but no amino acid differences were observed.


Assuntos
Substituição de Aminoácidos , Lebres/genética , Filogenia , Coelhos/genética , Receptores CXCR4/genética , Animais , Lebres/imunologia , Humanos , Myxoma virus/genética , Myxoma virus/imunologia , Mixomatose Infecciosa/genética , Mixomatose Infecciosa/imunologia , Coelhos/imunologia , Receptores CXCR4/imunologia , Especificidade da Espécie
13.
Int J Immunogenet ; 34(5): 321-4, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17845301

RESUMO

Homogenization of the CC-motif chemokine receptors CCR2 and CCR5 of cat (Felis catus) is documented and shown to be the outcome of gene conversion within the feline lineage. All regions were concerned, except the three extracellular protein domains (N- and C-tails, and ECL2), suggesting that structural differentiation at these domains could be related to pathogen susceptibility.


Assuntos
Gatos/genética , Conversão Gênica , Receptores CCR2/genética , Receptores CCR5/genética , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Filogenia , Receptores CCR2/classificação , Receptores CCR5/classificação
14.
Phys Rev Lett ; 97(16): 166103, 2006 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-17155416

RESUMO

Atomic force microscopy provides direct atomic-scale access to friction. In this paper, unexpected and potentially dramatic consequences of the tip elasticity are discussed. Under certain natural conditions an essentially new, nontrivial regime can be entered. Although the tip appears to perform typical stick-slip motion, the tip-surface contact is fully "lubricated" by fast thermal motion of the tip apex. The interpretation of the observations needs to be changed completely in this case.

15.
Biomed Pharmacother ; 60(6): 285-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16860527

RESUMO

The cell proliferation rate has been used to assess the biological aggressiveness and the metastatic potential of breast carcinoma. Different methods (flow cytometric S phase and proliferation associated antigens) have been used to assess the rate of proliferation previously. In this preliminary study, the cell proliferation rate of normal (N=45), benign (N=29) and invasive breast tumor tissue (N=70) has been quantified in vitro by ATP bioluminescence assay. Next, individual prognostic factor (tumor grades, lymph node involvement, estrogen and progesterone receptor and HER-2 status) has been correlated with the level of metabolic rate (ATP). The results showed that invasive tumor had the highest level of ATP bioluminescence compared with that of benign tumor (mean difference=1.97) and the normal breast tissue (mean difference=2.75). In addition, ATP level positively correlated with the number of axillary lymph node involvement (r(spearman)=0.433, P=0.021). These findings suggested that the measurement of ATP level may serve as a mean for the detection of cell proliferation and hence a surrogate marker for disease prognosis.


Assuntos
Trifosfato de Adenosina/metabolismo , Neoplasias da Mama/diagnóstico , Tomografia por Emissão de Pósitrons , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Quimioterapia Adjuvante , Feminino , Fibroadenoma/diagnóstico , Fibroadenoma/metabolismo , Fibroadenoma/patologia , Humanos , Medições Luminescentes , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo
16.
Biomed Pharmacother ; 60(6): 259-62, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16824726

RESUMO

Adjuvant therapy after surgery for breast cancer has provided significant benefits to patients at risk of relapse. However, the success of therapy for each individual patient will often take years to reveal. Preoperative therapy has brought about significant advances in the treatment of breast cancer. More breast conservation therapy can be performed and it becomes clear that pathologic complete response (pCR) is a good prognostic marker. Moreover, patients can be segregated into different clinical phenotypes after preoperative therapy: the responder non-recurrent, the responder recurrent, the non-responder non-recurrent and the non-responder recurrent. While conventional therapy and surgery is adequate for the responder non-recurrent and the non-responder non-recurrent cases, modification of conventional therapy, the adoption of a new approach or the incorporation of novel therapeutics may be necessary to improve the pCR and reduce recurrence for the later two groups of patients. Preoperative therapy has also made possible the development of biomarkers to predict response and resistance to treatment. With this translational approach, the therapy for each patient can be more targeted and individualized. A higher rate of success is expected.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Terapia Neoadjuvante , Quimioterapia Adjuvante , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Recidiva Local de Neoplasia/prevenção & controle , Resultado do Tratamento
17.
Thorax ; 61(7): 568-571, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16774949

RESUMO

BACKGROUND: Cigarette smoking causes accelerated facial wrinkling and predisposes to chronic obstructive pulmonary disease (COPD). However, it has long been recognised that there is a subgroup of susceptible smokers who are at increased risk of developing airflow obstruction. We have tested the hypothesis that there is a common susceptibility for the development of COPD and facial wrinkling in cigarette smokers. METHODS: One hundred and forty nine current and ex-smokers were recruited from a family based study of COPD genetics, 68 (45.6%) of whom fulfilled the definition of COPD. 124 (83.2%) had no or minor facial wrinkling (Daniell /=IV). Generalised estimating equations were used to adjust for familial correlations between related individuals and the potential confounding effects of age and pack years smoked. RESULTS: Forced expiratory volume in 1 second (FEV(1)) was significantly lower in those with wrinkles than in those without (mean difference in FEV(1) % predicted -13.7%, 95% CI -27.5 to 0.0, p = 0.05) and facial wrinkling was associated with a substantially increased risk of COPD (adjusted OR 5.0, 95% CI 1.3 to 18.5, p<0.02). The Daniell score correlated with the extent of emphysema on the CT scan (p<0.05) and facial wrinkling was also associated with a greater risk of more extensive emphysema (adjusted OR 3.0, 95% CI 1.0 to 9.3, p = 0.05). CONCLUSION: Facial wrinkling is associated with COPD in smokers, and both disease processes may share a common susceptibility. Facial wrinkling in smokers may therefore be a biomarker of susceptibility to COPD.


Assuntos
Doença Pulmonar Obstrutiva Crônica/etiologia , Envelhecimento da Pele , Fumar/efeitos adversos , Suscetibilidade a Doenças , Face/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/patologia , Envelhecimento da Pele/patologia
19.
Int J Immunogenet ; 33(3): 171-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16712647

RESUMO

Unlike other species, European rabbit (Oryctolagus cuniculus) possesses only one immunoglobulin gamma class. Allelic diversity at the Ig (immunoglobulin) gamma constant region encoded by the unique IGHG (immunoglobulin heavy gamma) gene is moreover much reduced. In the European rabbit, the genetic variation at IGGH hinge region is limited to a single nucleotide substitution, which causes a Met-Thr interchange at amino acid position 9 (IMGT hinge numbering). We have analysed the diversity at this region more in-depth by, (1) analysing the allelic variation in 11 breeds of domestic European rabbit (Oryctolagus cuniculus cuniculus), and (2) sequencing the gamma hinge exon in wild specimens of six species of rabbit (Oryctolagus and Sylvilagus) and hares (Lepus), including the two Oryctolagus subspecies (O. cuniculus cuniculus and O. cuniculus algirus). It appeared that among leporid species, amino acid changes occur exclusively at positions 8 and 9. However, while position 8 is occupied by either Pro or Ser residues, four different residues can occur at position 9 (Met, Thr, Pro and Leu). This variation concerns sites of potential O-glycosylation and/or proteolytic cleavage, suggesting that the underlying genetic diversity could be the outcome of selection. Preservation of the gamma hinge polymorphism in domestic stocks could therefore be important. We report here a polymerase chain reaction/restriction fragment length polymorphism protocol that has allowed the monitoring of the heterozygosity levels at the gamma hinge in 11 breeds of domestic European rabbit.


Assuntos
Alelos , Variação Genética , Lebres/genética , Éxons Codificadores da Região de Dobradiça/genética , Cadeias gama de Imunoglobulina/genética , Polimorfismo de Fragmento de Restrição , Animais , Variação Genética/imunologia , Lebres/imunologia , Éxons Codificadores da Região de Dobradiça/imunologia , Cadeias gama de Imunoglobulina/imunologia , Processamento de Proteína Pós-Traducional/genética , Processamento de Proteína Pós-Traducional/imunologia , Coelhos , Seleção Genética , Especificidade da Espécie
20.
Immunogenetics ; 58(5-6): 494-501, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16596402

RESUMO

Whereas in its natural host (Sylvilagus sps.) the effects of myxoma virus infections are benign, in European rabbit (Oryctolagus cuniculus), it causes a highly infectious disease with very high mortality rate, known as myxomatosis. There is evidence that, as with HIV-1 virus in human, myxoma virus may use chemokine receptors such as CCR5 of the host target cell for entry and activation of pathways of immune avoidance. We have characterized and compared CCR5 genes of leporid species with different susceptibility levels to myxomatosis. The CCR5 protein of O. cuniculus differs markedly from all those known from other species. The most striking was the replacement of a specific peptide motif of the second extracellular loop (ECL2) by a motif, which in other species characterizes the CCR2 molecules. While absent in Sylvilagus and Lepus species, this CCR2 imposed CCR5-ECL2 alteration was observed in all genomes of 25 European rabbits, representing the subspecies O. cuniculus algirus and O. cuniculus cuniculus. Allelic variation at the rabbit CCR5 locus confirmed that the gene conversion predates the subspecies split (1-2 Ma).


Assuntos
Lebres/genética , Lagomorpha/genética , Coelhos/genética , Receptores CCR5/genética , Receptores de Quimiocinas/genética , Alelos , Motivos de Aminoácidos/genética , Sequência de Aminoácidos , Animais , Conversão Gênica , Dados de Sequência Molecular , Mixomatose Infecciosa/genética , Polimorfismo Genético , Estrutura Terciária de Proteína , Receptores CCR2 , Receptores CCR5/classificação
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