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1.
Malays J Pathol ; 46(1): 51-62, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38682844

RESUMO

Small animal models play an important role in investigating and revealing the molecular determinants and mechanisms underlying neuro-virulence of enterovirus A71 (EV-A71). In our previous study, we successfully developed two mouse cell-line replication competent EV-A71 strains (EV71:TLLm and EV71:TLLmv) which were capable of inducing neuro-invasion in BALB/c mice. The more virulent EV71:TLLmv exhibited ability to induce acute encephalomyelitis accompanied by neurogenic pulmonary oedema. EV71:TLLcho virus strain was generated from EV71:TLLm by a series of passages in CHO-K1 cells. EV71:TLLcho demonstrated a broader range of infectivity across various mammalian cell lines and exhibited complete cytopathic effects (CPE) within 48 hours post-inoculation in comparison to EV71:TLLm or EV71:TLLmv. EV71:TLLcho consistently yielded higher levels of viral replication at all time points examined. In comparison to EV71:TLLm, EV71:TLLcho consistently induced more severe disease and increased mortality in one-week old BALB/c mice. However, unlike mice challenged with EV71:TLLmv, none of the mice challenged with EV71:TLLcho progressed to severe acute encephalomyelitis and developed neurogenic pulmonary oedema.


Assuntos
Modelos Animais de Doenças , Enterovirus Humano A , Infecções por Enterovirus , Camundongos Endogâmicos BALB C , Edema Pulmonar , Animais , Edema Pulmonar/virologia , Edema Pulmonar/patologia , Infecções por Enterovirus/complicações , Infecções por Enterovirus/virologia , Camundongos , Replicação Viral , Humanos
2.
Clin Oncol (R Coll Radiol) ; 34(9): e410-e419, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35717318

RESUMO

AIMS: The aim of TROG 14.04 was to assess the feasibility of deep inspiration breath hold (DIBH) and its impact on radiation dose to the heart in patients with left-sided breast cancer undergoing radiotherapy. Secondary end points pertained to patient anxiety and cost of delivering a DIBH programme. MATERIALS AND METHODS: The study comprised two groups - left-sided breast cancer patients engaging DIBH and right-sided breast cancer patients using free breathing through radiotherapy. The primary end point was the feasibility of DIBH, defined as left-sided breast cancer patients' ability to breath hold for 15 s, decrease in heart dose in DIBH compared with the free breathing treatment plan and reproducibility of radiotherapy delivery using mid-lung distance (MLD) assessed on electronic portal imaging as the surrogate. The time required for treatment delivery, patient-reported outcomes and resource requirement were compared between the groups. RESULTS: Between February and November 2018, 32 left-sided and 30 right-sided breast cancer patients from six radiotherapy centres were enrolled. Two left-sided breast cancer patients did not undergo DIBH (one treated in free breathing as per investigator choice, one withdrawn). The mean heart dose was reduced from 2.8 Gy (free breathing) to 1.5 Gy (DIBH). Set-up reproducibility in the first week of treatment assessed by MLD was 1.88 ± 1.04 mm (average ± 1 standard deviation) for DIBH and 1.59 ± 0.93 mm for free breathing patients. Using a reproducibility cut-off for MLD of 2 mm (1 standard deviation) as per study protocol, DIBH was feasible for 67% of DIBH patients. Radiotherapy delivery using DIBH took about 2 min longer than for free breathing. Anxiety was not significantly different in DIBH patients and decreased over the course of treatment in both groups. CONCLUSION: Although DIBH was shown to require about 2 min longer per treatment slot, it has the potential to reduce heart dose in left-sided breast cancer patients by nearly a half, provided careful assessment of breath hold reproducibility is carried out.


Assuntos
Neoplasias da Mama , Neoplasias Unilaterais da Mama , Neoplasias da Mama/radioterapia , Suspensão da Respiração , Estudos de Viabilidade , Feminino , Coração , Humanos , Órgãos em Risco , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Reprodutibilidade dos Testes , Neoplasias Unilaterais da Mama/radioterapia
3.
Breast ; 22(6): 1019-25, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24070852

RESUMO

Ductal carcinoma in situ (DCIS) is a heterogeneous, pre-malignant disease accounting for 10-20% of all new breast tumours. Evidence shows a statistically significant local control benefit for adjuvant radiotherapy (RT) following breast conserving surgery (BCS) for all patients. The baseline recurrence risk of individual patients varies according to clinical-pathological criteria and in selected patients, omission of RT may be considered, following a discussion with the patient. The role of adjuvant endocrine therapy remains uncertain. Ongoing studies are attempting to define subgroups of patients who are at sufficiently low risk of recurrence that RT may be safely omitted; investigating RT techniques and dose fractionation schedules; and defining the role of endocrine therapy. Future directions in the management of patients with DCIS will include investigation of prognostic and predictive biomarkers to inform individualised therapy tailored to the risk of recurrence.


Assuntos
Neoplasias da Mama/terapia , Carcinoma in Situ/terapia , Carcinoma Ductal de Mama/terapia , Recidiva Local de Neoplasia , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma in Situ/patologia , Carcinoma in Situ/cirurgia , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Quimioterapia Adjuvante , Feminino , Humanos , Mastectomia Segmentar , Recidiva Local de Neoplasia/patologia , Radioterapia Adjuvante , Fatores de Risco , Tamoxifeno/uso terapêutico
4.
Ann Oncol ; 23(11): 2852-2858, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22776708

RESUMO

BACKGROUND: Rates and risk factors of local, axillary and supraclavicular recurrences can guide patient selection and target for postmastectomy radiotherapy (PMRT). PATIENTS AND METHODS: Local, axillary and supraclavicular recurrences were evaluated in 8106 patients enrolled in 13 randomized trials. Patients received chemotherapy and/or endocrine therapy and mastectomy without radiotherapy. Median follow-up was 15.2 years. RESULTS: Ten-year cumulative incidence for chest wall recurrence of >15% was seen in patients aged <40 years (16.1%), with ≥4 positive nodes (16.5%) or 0-7 uninvolved nodes (15.1%); for supraclavicular failures >10%: ≥4 positive nodes (10.2%); for axillary failures of >5%: aged <40 years (5.1%), unknown primary tumor size (5.2%), 0-7 uninvolved nodes (5.2%). In patients with 1-3 positive nodes, 10-year cumulative incidence for chest wall recurrence of >15% were age <40, peritumoral vessel invasion or 0-7 uninvolved nodes. Age, number of positive nodes and number of uninvolved nodes were significant parameters for each locoregional relapse site. CONCLUSION: PMRT to the chest wall and supraclavicular fossa is supported in patients with ≥4 positive nodes. With 1-3 positive nodes, chest wall PMRT may be considered in patients aged <40 years, with 0-7 uninvolved nodes or with vascular invasion. The findings do not support PMRT to the dissected axilla.


Assuntos
Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Metástase Linfática , Mastectomia , Recidiva Local de Neoplasia , Adulto , Axila , Neoplasias da Mama/patologia , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/patologia , Pessoa de Meia-Idade , Radioterapia Adjuvante , Receptores de Estrogênio/metabolismo , Fatores de Risco , Falha de Tratamento
5.
J Med Imaging Radiat Oncol ; 53(4): 412-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19695049

RESUMO

INTRODUCTION: Inconsistencies in contouring target volumes for partial breast irradiation (PBI) may result in geographical misses and compromise treatment outcomes. The present study aimed to (1) determine the variability of the target volumes contoured and treatment plans generated by participating centres in credentialing for participation in a multicentre PBI trial; and (2) assess dosimetric changes when standardized target volumes were used. METHODS: The CT image sets of two de-identified patients post-breast conserving surgery were used. Contouring of the target volumes for the two cases was performed and a treatment plan as per protocol specifications was generated for each case by the seven participating centres. Planning of both cases was repeated by five centres using a set of standardized target volumes to evaluate resulting dosimetric changes in the treatment plans. RESULTS: The surgical cavity, the part of the planning target volume used for dose evaluation and ipsilateral whole breast volumes contoured by the centres varied by 25%, 16% and 21% (1 standard deviation), respectively. The dosimetric variations found when the standardized target volumes were used were smaller than those noted when centre-specific volumes were used. The volumes of the ipsilateral lungs receiving 30% of the prescribed dose and the volumes of the ipsilateral whole breasts receiving 95% and 50% of the prescribed dose were reduced in the treatment plans developed using the standardized target volumes. CONCLUSIONS: Given the impact of contouring on dose distributions, quality assurance procedures in clinical trials of PBI need to take into account both the technical approaches and the contouring.


Assuntos
Neoplasias da Mama/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Ensaios Clínicos como Assunto , Fracionamento da Dose de Radiação , Estudos de Viabilidade , Feminino , Humanos , Nova Zelândia , Resultado do Tratamento
6.
Genetika ; 43(5): 668-74, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17633561

RESUMO

Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique namely Random Amplified Polymorphic DNA (RAPD) to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively' uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA done based on the RAPD makers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution.


Assuntos
Variação Genética , Metais Pesados/análise , Perna (Organismo)/química , Perna (Organismo)/genética , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental , Marcadores Genéticos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNA
7.
Malays J Pathol ; 29(2): 69-78, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19108398

RESUMO

All known field isolates of enterovirus 71 (EV71) can be divided into three distinct genogroups (A, B, C) and 10 subgenogroups (A, B1-5, C1-4) based on VP1 gene sequences. We examined VP1 gene sequences of 10, 12 and 11 EV71 strains isolated in peninsular Malaysia during the outbreaks of hand, foot and mouth disease in 1997, 2000 and 2005 respectively. Four EV71 strains isolated in the hand, foot and mouth disease outbreak of 2006 in Sarawak (Malaysian Borneo) were included to describe their genetic relationship. Four subgenogroups (C1, C2, B3 and B4) of EV71 co-circulated and caused the outbreak of hand, foot and mouth disease in peninsular Malaysia in 1997. Two subgenogroups (C1 and B4) were noted to cause the outbreak in 2000. In the 2005 outbreak, besides EV71 strains of subgenogroup C1, EV71 strains belonged to subgenogroup B5 were isolated but formed a cluster which was distinct from EV71 strains of the subgenogroup B5 isolated in 2003. The four EV71 strains isolated from clinical specimens of patients with hand, foot and mouth disease in the Sarawak outbreak in early 2006 also belonged to subgenogroup B5. Phylogenetic analysis of the VP1 gene sequences showed that the four Sarawak EV71 isolates belonged to the same cluster as the EV71 strains that were isolated in peninsular Malaysia as early as May 2005. The data suggested that the EV71 strains causing the outbreak in Sarawak could have originated from peninsular Malaysia.


Assuntos
Surtos de Doenças , Enterovirus Humano A/genética , Doença de Mão, Pé e Boca/genética , Doença de Mão, Pé e Boca/virologia , Sequência de Bases , Proteínas do Capsídeo/genética , Enterovirus Humano A/isolamento & purificação , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência
8.
Arch Virol ; 148(7): 1369-85, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12827466

RESUMO

Human enterovirus 71 (EV71) (genus Enterovirus, family Picornaviridae) has been responsible for sporadic cases and outbreaks of hand-foot-and-mouth disease (HFMD), aseptic meningitis, encephalitis and poliomyelitis-like disease in Europe, the U.S.A., Australia and Asia. Recently, there has been an increase in EV71 activity in the Asia-Pacific region, with many outbreaks of HFMD associated with brainstem encephalitis manifesting as neurogenic pulmonary oedema with a high case fatality rate. In 1997, and again in 2000, EV71 outbreaks occurred in peninsular Malaysia. Variations in VP1 gene sequences have been shown to divide all known EV71 field isolates into three distinct genogroups (A, B and C). Consequently we examined the VP1 gene sequences of 43 EV71 strains isolated in peninsular Malaysia between 1997 and 2000 in order to determine the genogroup prevalence over the period. In this study we show that four subgenogroups (B3, B4, C1 and C2) of EV71 circulated in peninsular Malaysia between 1997 and 2000. Subgenogroups B3, B4 and C1 have been identified as the primary cause of the outbreaks of EV71 in peninsular Malaysia. Subgenogroup C1 also displayed endemic circulation from 1997 to 2000 and subgenogroup C2 was present at a low level during the 1997 outbreak.


Assuntos
Infecções por Enterovirus/epidemiologia , Enterovirus/genética , Doença de Mão, Pé e Boca/epidemiologia , Sequência de Aminoácidos , Sequência de Bases , Sequência Consenso , Primers do DNA , Surtos de Doenças , Enterovirus/classificação , Enterovirus/patogenicidade , Genótipo , Geografia , Doença de Mão, Pé e Boca/mortalidade , Humanos , Incidência , Malásia/epidemiologia , Epidemiologia Molecular/métodos , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência
9.
Med J Malaysia ; 57(1): 80-7, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14569722

RESUMO

This is a 10-year retrospective review of mucocutaneous infection by human herpesvirus 1 (HHV1) and human herpesvirus 2 (HHV2) carried out by the virus diagnostic unit of University Malaya Medical Centre (UMMC). A total of 504 specimens from UMMC and a private clinic in the same city (KLSC) were tested; 198 samples from patients with oral lesions and 306 from patients with genital lesions. HHV1 was found to be responsible for 98.4% of oral lesions whereas HHV2 was the cause of 83.6% of all genital lesions. Detailed analysis showed no statistical difference by age group, race or gender among the patients with oral and genital lesions. Two laboratory methods were used in this study. Of the total 504 specimens tested, 18.0% specimens were positive by direct immunofluorescence (IF), 55.0% by virus isolation and 56.5% when both methods were used in combination. Although IF can provide a more rapid diagnosis, it is, however, less sensitive and can be attributed partly to inadequate collection of specimens.


Assuntos
Herpes Simples/epidemiologia , Herpes Simples/virologia , Herpesvirus Humano 1/isolamento & purificação , Herpesvirus Humano 2/isolamento & purificação , População Urbana/estatística & dados numéricos , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Herpes Simples/diagnóstico , Humanos , Malásia/epidemiologia , Masculino , Estudos Retrospectivos
10.
Med J Malaysia ; 57(1): 88-91, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14569723

RESUMO

The prevalence of HFMD as well as the causative agents was unknown in peninsular Malaysia prior to May 1997. From May 1997 to June 2001, 585 patients suspected to have enterovirus infections, with 467 patients clinically diagnosed as having HFMD, were investigated in the diagnostic virology unit of the University Malaya Medical Centre. Data from this study showed that HFMD is endemic in Malaysia with the occurrence of two outbreaks during the study period. In each outbreak, a number of viruses were isolated but enterovirus 71 was the main virus isolated in both outbreaks. Echovirus 7 (Eo7) was isolated from 5 patients with HFMD in the second outbreak, a clinical entity that has not been attributed to it previously. Children aged 4 years and below, particularly those between 1 and 2 years of age, were in the main group of patients affected by the illness. HFMD by itself and without neurological involvement was relatively benign and self-limiting. There was no significant difference in the virus isolation rate with respect to gender and ethnic groups. Virus isolation was attempted in a total of 764 clinical specimens consisting of 342 stool specimens, 285 oral secretions specimens and 137 vesicular fluid specimens. Oral specimens gave the highest virus isolation rate (33.3%) followed by vesicular specimens (27.0%). Stool specimens only yielded an isolation rate of 14.0%.


Assuntos
Doença de Mão, Pé e Boca/epidemiologia , Centros Médicos Acadêmicos/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Doença de Mão, Pé e Boca/virologia , Humanos , Lactente , Malásia/epidemiologia , Masculino , Estudos Retrospectivos
11.
Med J Malaysia ; 57(1): 97-103, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14569725

RESUMO

A seroepidemiological study carried out on 800 stored serum samples collected between January 1999 to December 2000 derived from an urban population in Malaysia showed that the overall seropositive rate of human paravovirus B19 infection was 37.6%, with an overall geometric mean titre (GMT) of 18.3 IU. The seropositive rates of B19 among the male and female populations were 39.0% and 36.3% respectively. The seropositive rates among the racial groups were 37.2%, 38.2%, 38.1% and 29.4% respectively for the Malays, Chinese, Indians and other races. There was no statistical significant gender and racial differences in the B19 seropositive rates. When compared with the seroprevalence of B19 infection in other Asian countries, the seropositive rate of B19 in Malaysia was low in the younger age group and increased steadily with age. The unusual finding in this study was the presence of a high seropositive rate in those between six months to five years of age, especially in children in the one year old age group.


Assuntos
Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Parvovirus B19 Humano/isolamento & purificação , População Urbana/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Infecções por Parvoviridae/sangue , Estudos Soroepidemiológicos , Distribuição por Sexo
12.
J Mol Cell Cardiol ; 33(12): 2135-44, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11735260

RESUMO

Our previous work in cultured cells has shown that the maintenance of mitochondrial Ca(2+) homeostasis is essential for cell survival, and that the anti-apoptotic protein Bcl-2 is able to maintain a threshold level of mitochondrial Ca(2+) by the inhibition of permeability transition. To test whether Bcl-2 also affects the mitochondrial Na(+)-Ca(2+) exchange (NCE), a major efflux pathway for mitochondrial Ca(2+), studies using transgenic mice that overexpress Bcl-2 in the heart have been performed. NCE activity was determined as the Na(+)-dependent Ca(2+) efflux in the isolated mitochondria. Overexpression of Bcl-2 led to a significant reduction of NCE activity as well as increased resistance to permeability transition in the mitochondria of transgenic heart. This was accompanied by increased matrix Ca(2+) level, enhanced formation of NADH and enhanced oxidation of pyruvate, an NAD(+)-linked substrate. Furthermore, there was induction of cellular Ca(2+) transport proteins including the Na(+)-Ca(2+) exchanger of the sarcolemma (NCX). Bcl-2 not only stimulates NCX expression in the sarcolemma but also attenuates the Na(+)-Ca(2+) exchange in the mitochondria. These results are consistent with the protection by Bcl-2 against apoptosis in heart following ischemia/reperfusion.


Assuntos
Mitocôndrias Cardíacas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Animais , Cálcio/metabolismo , Regulação da Expressão Gênica , Homeostase , Humanos , Membranas Intracelulares/metabolismo , Camundongos , Camundongos Transgênicos , NAD/metabolismo , Permeabilidade , Sarcolema/metabolismo
13.
J Gen Virol ; 82(Pt 11): 2629-2639, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11602774

RESUMO

The complete nucleotide sequences are reported of two strains of echovirus 7, the prototype Wallace strain (Eo7-Wallace) and a recent Malaysian strain isolated from the cerebrospinal fluid of a child with fatal encephalomyelitis (Eo7-UMMC strain). The molecular findings corroborate the serological placement of the UMMC strain as echovirus 7. Both Eo7-Wallace and Eo7-UMMC belong to the species human enterovirus B and are most closely related to echovirus 11. Eo7-UMMC has undergone significant genetic drift from the prototype strain in the 47 years that separate the isolation of the two viruses. Phylogenetic analysis revealed that Eo7-UMMC did not arise from recombination with another enterovirus serotype. The molecular basis for the severely neurovirulent phenotype of Eo7-UMMC remains unknown. However, it is shown that mutations in the nucleotide sequence of the 5' untranslated region (UTR) of Eo7-UMMC result in changes to the putative structure of the 5' UTR. It is possible that these changes contribute to the neurovirulence of Eo7-UMMC.


Assuntos
Encefalite Viral/virologia , Enterovirus Humano B/genética , Infecções por Enterovirus/virologia , Frequência do Gene , Genoma Viral , Regiões 3' não Traduzidas/química , Regiões 5' não Traduzidas/química , Sequência de Aminoácidos , Sequência de Bases , Líquido Cefalorraquidiano/virologia , Pré-Escolar , Enterovirus Humano B/química , Enterovirus Humano B/classificação , Humanos , Masculino , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Filogenia , Análise de Sequência de DNA
14.
Am J Physiol Heart Circ Physiol ; 280(5): H2313-20, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11299236

RESUMO

To test whether the antiapoptotic protein Bcl-2 prevents apoptosis and injury of cardiomyocytes after ischemia-reperfusion (I/R), we generated a line of transgenic mice that carried a human Bcl-2 transgene under the control of a mouse alpha-myosin heavy chain promoter. High levels of human Bcl-2 transcripts and 26-kDa Bcl-2 protein were expressed in the hearts of transgenic mice. Functional recovery of the transgenic hearts significantly improved when they were perfused as Langendorff preparations. This protection was accompanied by a threefold decrease in lactate dehydrogenase (LDH) released from the transgenic hearts. The transgenic mice were subjected to 50 min of ligation of the left descending anterior coronary artery followed by reperfusion. The infarct sizes, expressed as a percentage of the area at risk, were significantly smaller in the transgenic mice than in the nontransgenic mice (36.6 +/- 5 vs 69.9 +/- 7.3%, respectively). In hearts subjected to 30 min of coronary artery occlusion followed by 3 h of reperfusion, Bcl-2 transgenic hearts had significantly fewer terminal deoxynucleodidyl-transferase nick-end labeling-positive or in situ oligo ligation-positive myocytes and a less prominent DNA fragmentation pattern. Our results demonstrate that overexpression of Bcl-2 renders the heart more resistant to apoptosis and I/R injury.


Assuntos
Apoptose/fisiologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Animais , Expressão Gênica/fisiologia , Humanos , Marcação In Situ das Extremidades Cortadas , L-Lactato Desidrogenase/metabolismo , Camundongos , Camundongos Transgênicos , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/química , Miocárdio/enzimologia , Miocárdio/patologia , Proteínas Proto-Oncogênicas c-bcl-2/análise
15.
Free Radic Biol Med ; 29(7): 589-96, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11033410

RESUMO

Superoxide dismutase scavenges oxygen radicals, which have been implicated in ischemia/reperfusion (I/R) injury in the heart. Our experiments were designed to study the effect of a moderate increase of copper/zinc superoxide dismutase (CuZnSOD) on myocardial I/R injury in TgN(SOD1)3Cje transgenic mice. A species of 0.8 kb human CuZnSOD mRNA was expressed, and a 273% increase in CuZnSOD activity was detected in the hearts of transgenic mice with no changes in the activities of other antioxidant enzymes. Furthermore, immunoblot analysis revealed no changes in the levels of HSP-70 or HSP-25 levels. Immunocytochemical study indicated that there was increased labeling of CuZnSOD in the cytosolic fractions of both endothelial cells and smooth muscle cells, but not in the myocytes of the hearts from transgenic mice. When these hearts were perfused as Langendorff preparations for 45 min after 35 min of global ischemia, the functional recovery of the hearts, expressed as heart rate x LVDP, was 48 +/- 3% in the transgenic hearts as compared to 30 +/- 5% in the nontransgenic hearts (p <.05). The improved cardiac function was accompanied by a significant reduction in lactate dehydrogenase release from the transgenic hearts. Our results demonstrate that overexpression of CuZnSOD in coronary vascular cells renders the heart more resistant to I/R injury.


Assuntos
Antioxidantes/metabolismo , Vasos Coronários/enzimologia , Endotélio Vascular/enzimologia , Músculo Liso Vascular/enzimologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/enzimologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Transcrição Gênica , Animais , Catalase/metabolismo , Vasos Coronários/patologia , Endotélio Vascular/patologia , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Proteínas de Choque Térmico HSP27 , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/metabolismo , Humanos , Técnicas In Vitro , L-Lactato Desidrogenase/análise , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Chaperonas Moleculares , Músculo Liso Vascular/patologia , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Proteínas de Neoplasias/metabolismo , RNA Mensageiro/genética
16.
Biochim Biophys Acta ; 1497(1): 69-76, 2000 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-10838160

RESUMO

Transforming growth factor-beta1 (TGF-beta1), an abundant growth factor in bone matrix, has been shown to be involved in bone formation and fracture healing. The mechanism of action of the osteogenic effect of TGF-beta1 is not clearly understood. In this study, we found that the addition of TGF-beta1 to murine osteoblastic MC3T3-E1 cells induced vascular endothelial growth factor (VEGF) mRNA production. VEGF mRNA levels reached a plateau within 2 h after the addition of TGF-beta1. The induction was superinduced by cycloheximide and blocked by actinomycin D. Ro 31-8220, a protein kinase C inhibitor, abrogated the induction. In addition, curcumin, an inhibitor for transcription factor AP-1, also blocked the induction. Electrophoretic mobility shift assay revealed an enhanced binding of transcription factors AP-1 and NF-kappaB. Transient transfection experiment showed that VEGF promoter activity increased 3.6-fold upon TGF-beta1 stimulation. Immunoblot analysis showed that the amount of secreted VEGF was elevated in the medium 4 h after TGF-beta1 stimulation. Our results therefore suggest that at least part of the osteogenic activity of TGF-beta1 may be attributed to the production of VEGF.


Assuntos
Fatores de Crescimento Endotelial/genética , Linfocinas/genética , Osteoblastos/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia , Animais , Western Blotting , Linhagem Celular , Curcumina/farmacologia , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Fatores de Crescimento Endotelial/metabolismo , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Indóis/farmacologia , Luciferases/genética , Luciferases/metabolismo , Linfocinas/metabolismo , Camundongos , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Regiões Promotoras Genéticas/genética , Proteína Quinase C/antagonistas & inibidores , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Tempo , Fator de Transcrição AP-1/efeitos dos fármacos , Fator de Transcrição AP-1/metabolismo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
17.
Med J Malaysia ; 55(3): 299-303, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11200707

RESUMO

A retrospective review of rubella serological results carried out in the Virus Diagnostic Unit, University Hospital Kuala Lumpur (UHKL) from January 1993 to September 1999 showed the presence of rubella infection annually which appeared to increase periodically every two to three years. There was no statistical significant difference in the rubella positive rate between male and female population aged 14 to 48 years. Congenital rubella infections (CRI) occurred in babies delivered in UHKL yearly from 1993 to 1998 with an average incidence rate of 48 per 100,000 deliveries. Peaks of rubella cases appeared to be followed by an increase in incidence of CRI cases 6 to 9 months later. The study showed that only 50.8% clinically diagnosed rubella was confirmed by laboratory finding. This study also showed an increase of rubella activity for the months of July, August and September 1999 and this may herald an increase of CRI cases in the coming millennium.


Assuntos
Rubéola (Sarampo Alemão)/epidemiologia , Adolescente , Adulto , Feminino , Humanos , Incidência , Malásia , Masculino , Pessoa de Meia-Idade , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Estudos Retrospectivos , Rubéola (Sarampo Alemão)/congênito , Rubéola (Sarampo Alemão)/diagnóstico , Rubéola (Sarampo Alemão)/prevenção & controle , Testes Sorológicos , Vacinação/normas
18.
Free Radic Biol Med ; 25(8): 891-7, 1998 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9840733

RESUMO

Hydrogen peroxide (H2O2) is a reactive oxygen species generated by several metabolic pathways in mammalian cells. Endothelial cells are extremely susceptible to oxidative stress. H2O2 has been reported to increase the permeability in these cells. Using rat heart endothelial cell culture as a model system, we examined the effect of H2O2 on the gene expression of vascular endothelial growth factor (VEGF), a potent mitogen of endothelial cells and a vascular permeability factor. By Northern blot analysis we found that VEGF mRNA responded to H2O2 in a dose-and time-dependent manner. The induction was superinduced by cycloheximide and blocked by actinomycin D. N-Acetylcysteine, a synthetic antioxidant, was able to suppress the induction. H7, a protein kinase C inhibitor, could also block the induction. Electrophoretic mobility shift assay revealed an enhanced binding of transcription factors, AP-1 and NF-kappaB. Immunoblot analysis showed that the amount of secreted VEGF was elevated in the medium 4 h after H2O2 stimulation. Our results demonstrate that VEGF gene expression is upregulated by H2O2 in these endothelial cells.


Assuntos
Fatores de Crescimento Endotelial/genética , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Coração , Peróxido de Hidrogênio/farmacologia , Linfocinas/genética , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Northern Blotting , Células Cultivadas , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Cinética , Inibidores de Proteínas Quinases , Proteínas Quinases/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/biossíntese , Ratos , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
19.
Biochim Biophys Acta ; 1405(1-3): 29-34, 1998 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-9784597

RESUMO

Addition of lysophosphatidic acid (LPA) to rat aorta-derived endothelial cells significantly induced preproendothelin-1 (preproET-1) mRNA expression. PreproET-1 mRNA levels reached a plateau within 1 h after the addition of 0.5 microM LPA and declined after 2 h. The induction was superinduced by cycloheximide and was blocked by actinomycin D. Suramin, an LPA receptor antagonist, abolished the induction of preproET-1 mRNA by LPA. Protein kinase C inhibitors, H7 and bisindolylmaleimide, were able to block the induction. Transient transfection experiment revealed that the elevated preproET-1 mRNA was a result of the activation of ET-1 gene activity. Electrophoretic mobility shift assay revealed that LPA stimulated the binding of AP-1. The secreted level of ET-1 was elevated 2.3-fold after 12 h of stimulation with LPA. Our results suggest that the upregulation of preproET-1 by LPA may serve to augment and prolong the vasoconstriction action of LPA.


Assuntos
Endotelina-1/biossíntese , Endotelina-1/genética , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Lisofosfolipídeos/farmacologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Animais , Células Cultivadas , Endotelinas/genética , Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Maleimidas/farmacologia , Proteína Quinase C/antagonistas & inibidores , Precursores de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Fator de Transcrição AP-1/metabolismo , Regulação para Cima/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos
20.
Biochim Biophys Acta ; 1401(2): 187-94, 1998 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-9531974

RESUMO

Vascular endothelial growth factor (VEGF) is a potent mitogen for endothelial cells and a vascular permeability factor. In this study we found that the addition of angiotensin II (AII) to rat heart endothelial cells induced VEGF mRNA production. VEGF mRNA levels reached a plateau within 2 h after the addition of AII and decreased after 4 h. The induction was superinduced by cycloheximide and blocked by actinomycin D. Losartan, an AT1 receptor antagonist, abolished the induction of VEGF mRNA by AII, whereas PD 123319, an AT2 receptor antagonist, had no effect on VEGF mRNA induction. H7, a protein kinase C inhibitor, blocked the induction. RT-PCR experiments showed two mRNA species (VEGF 120 and VEGF 164) in these cells and both species were stimulated by AII. Transient transfection experiment showed that VEGF promoter activity was increased 2.2-fold upon AII stimulation. Electrophoretic mobility shift assay revealed an enhanced binding of transcription factors AP-1 and NF-kappa B. Immunoblot analysis showed that the amount of secreted VEGF was elevated in the medium 8 h after AII stimulation. Our results demonstrate for the first time that the upregulation of VEGF by AII may play a significant role in AII-induced hyperpermeability.


Assuntos
Angiotensina II/farmacologia , Fatores de Crescimento Endotelial/análise , Fatores de Crescimento Endotelial/fisiologia , Endotélio Vascular/citologia , Linfocinas/análise , Linfocinas/efeitos dos fármacos , Linfocinas/fisiologia , Vasoconstritores/farmacologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Angiotensina II/administração & dosagem , Animais , Anti-Hipertensivos/farmacologia , Northern Blotting , Bovinos , Meios de Cultivo Condicionados/análise , Meios de Cultivo Condicionados/química , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Relação Dose-Resposta a Droga , Fatores de Crescimento Endotelial/genética , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Immunoblotting , Losartan/farmacologia , Linfocinas/genética , Inibidores da Síntese de Ácido Nucleico/farmacologia , Proteína Quinase C/antagonistas & inibidores , Inibidores da Síntese de Proteínas/farmacologia , Piridinas/farmacologia , RNA Mensageiro/análise , RNA Mensageiro/efeitos dos fármacos , Ratos , Fatores de Transcrição/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Vasoconstritores/administração & dosagem
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