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1.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 40(10): 771-775, 2022 Oct 20.
Artigo em Chinês | MEDLINE | ID: mdl-36348560

RESUMO

Objective: To compare the efficacy of high-flow nasal cannula oxygen therapy (HFNC) and non-rebreather face mask (NRFM) in the treatment of mild acute carbon monoxide poisoning (ACOP) in reducing carboxyhemoglobin (COHb) , and to explore the feasibility of HFNC in the treatment of ACOP. Methods: Patients with mild ACOP with COHb >10% who were admitted to the emergency department of Northern Jiangsu People's Hospital from January 2015 to December 2020 were analyzed, and those with altered consciousness, mechanical ventilation and those requiring hyperbaric oxygen therapy were excluded. The patients were divided into HFNC group and NRFM group according to the oxygen therapy used in the emergency department. The COHb decline value and COHb half-life in the two groups were observed. Results: Seventy-one patients were enrolled, including 39 in the NRFM group and 32 in the HFNC group. The baseline COHb in the HFNC group was 24.8%±8.3%, and that in the NRFM group was 22.5%±7.1%, with no significant difference between the two groups (t=1.27, P=0.094) . At 60 min, 90 min and 120 min of treatment, COHb in both groups decreased, but the COHb in HFNC group was lower than that in NRFM group at the same time point (P<0.05) . After 1 h of treatment, the COHb decrease in the HFNC group (16.9%±4.5%) was significantly higher than that in the NRFM group (10.1%±7.8%) (t=4.32, P=0.013) . The mean half-life of COHb in the HFNC group (39.3 min) was significantly lower than that in the NRFM group (61.4 min) (t=4.69, P=0.034) . Conclusion: HFNC treatment of mild ACOP can rapidly reduce blood COHb level, it is a potential oxygen therapy method for clinical treatment of ACOP.


Assuntos
Intoxicação por Monóxido de Carbono , Insuficiência Respiratória , Humanos , Intoxicação por Monóxido de Carbono/terapia , Cânula , Respiração Artificial , Máscaras , Oxigenoterapia/métodos , Carboxihemoglobina , Oxigênio/uso terapêutico , Insuficiência Respiratória/terapia
2.
Commun Med (Lond) ; 2(1): 144, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36380151

RESUMO

BACKGROUND: A recent dramatic surge in pet ownership has been observed across metropolitan areas in Asia. To date, there is a dearth of information on the risk associated with pet ownership for the transmission of parasites on a large scale in Asia, despite this continent giving rise to the largest burden of zoonotic infections worldwide. METHODS: We explored the nature and extent of zoonotic internal (endo-) and external (ecto-) parasites and arthropod-borne pathogens in 2381 client-owned dogs and cats living in metropolitan areas of eight countries in East and Southeast Asia using reliable diagnostic tests and then undertook extensive statistical analyses to define predictors of exposure to zoonotic pathogens. RESULTS: The estimated ORs for overall parasite infections are 1.35 [95% CIs 1.07;1.71] in young animals and 4.10 [1.50;11.2] in the animal group older than 15 years as compared with adult animals, 0.61 [0.48;0.77] in neutered animals as compared to unneutered animals, 0.36 [0.26;0.50] in animals living in urban areas as compared with rural areas, 1.14 [1.08;1.21] for each 1 °C increase of annual mean temperature which varies from 12.0 to 28.0 °C, and 0.86 [0.78;0.95] for each year of life expectancy which varies from 70.9 to 83.3 years. CONCLUSIONS: Here we highlight the influence of human life expectancy and the neutering status of the animals, which reflect increased living standards through access to education and human and veterinary health care, to be both strongly associated with exposure to zoonotic parasites. An integrated approach of local and international authorities to implement and manage educational programs will be crucial for the control of zoonotic infections of companion animals in Asia.


Parasites live on or inside animals or humans and can cause disease. Companion animals (pets) with parasites present a potential risk to the health of their owners, as certain kinds of parasites (known as zoonotic parasites) can affect both animal and human health. Here, we investigated whether human social conditions are associated with zoonotic parasite infections in companion animals in East and Southeast Asia. We found that higher human life expectancy and neutering of the companion animals were associated with fewer zoonotic parasite infections in the animals. These findings highlight the need for an enhanced commitment of local authorities to establish prevention campaigns, including education programs, against zoonotic pathogens. These measures will play a crucial role in alleviating the impact of these diseases in companion animals and humans in Asia.

3.
Vet Microbiol ; 254: 109008, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33582484

RESUMO

Feline leukaemia virus (FeLV) is a retrovirus associated with fatal disease in cats with infection in its progressive form. Although there are numerous reports on the occurrence of FeLV in the feline population worldwide, there is a paucity of data in Asia. In this study, we assessed the circulation of FeLV by ELISA and nested PCR in cats from different countries in Southeast Asia (i.e., Thailand, Malaysia, Singapore, Philippines, Indonesia and Vietnam) and Taiwan during 2017-2018. Forty-seven cats were positive to FeLV by antigen or provirus detection, but 32 samples were considered truly positive on the basis of positive molecular testing. Frequency of occurrence of FeLV proviral DNA ranged from 0% (0/43 positive samples) in Indonesia to 18.5% (22/119 positive samples) in Thailand. A statistically significant association (p < 0.05) was found between country of cats origin, age, lifestyle, abnormal oral mucosa, and FeLV molecular positive results. In-depth studies are needed in other countries in Southeast Asia to elucidate the mosaic of knowledge about FeLV epidemiology.


Assuntos
Doenças do Gato/epidemiologia , Vírus da Leucemia Felina/genética , Animais de Estimação/virologia , Infecções por Retroviridae/veterinária , Infecções Tumorais por Vírus/veterinária , Animais , Sudeste Asiático/epidemiologia , Doenças do Gato/sangue , Doenças do Gato/virologia , Gatos/virologia , DNA Viral/genética , Feminino , Vírus da Leucemia Felina/classificação , Vírus da Leucemia Felina/isolamento & purificação , Masculino , Provírus/genética , Infecções por Retroviridae/sangue , Infecções por Retroviridae/epidemiologia , Fatores de Risco , Taiwan/epidemiologia , Infecções Tumorais por Vírus/epidemiologia , Carga Viral
4.
Plant Biol (Stuttg) ; 19(1): 14-22, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27037632

RESUMO

Considerable variation occurs in post-maturity timing of dehiscence in fruits of Brassicaceae species, and several studies have shown that the pericarp plays an important role in seed germination and retention of viability in species with indehiscent fruits. However, little is known about the significance to seed biology of delay in pericarp dehiscence for <1 year in the field. Thus, we determined the role of the pericarps of Leptaleum filifolium and Neotorularia korolkovii, which open in <1 year after fruit maturity and dispersal, in seed germination and retention of seed viability. We compared dormancy-break via after-ripening in the laboratory and germination phenology and retention of seed viability in intact siliques and isolated seeds buried in an experimental garden. Seeds of both species have Type 6 non-deep physiological dormancy, which is enhanced by the pericarp. Seeds of both species after-ripened during summer 2013, and some of them germinated in autumn and some in the following spring in watered and non-watered soil. Germination percentages of seeds in siliques increased in soil in spring 2014, after the pericarps had opened. Most isolated seeds of L. filifolium and N. korolkovii had germinated or were dead by spring 2014 and summer 2015, respectively, whereas 60% of the seeds of both species in the (opened) pericarps were viable after 24 months. Thus, although the pericarp opened 9-10 months after burial, its presence had a significant effect on seed dormancy, germination phenology and retention of viability of seeds of L. filifolium and N. korolkovii.


Assuntos
Brassicaceae/fisiologia , Germinação , Sementes/fisiologia , Frutas/fisiologia , Dormência de Plantas , Estações do Ano , Solo/química , Água/fisiologia
5.
Clin Oncol (R Coll Radiol) ; 26(11): 684-91, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25194727

RESUMO

AIMS: At our centre, ductal carcinoma in situ (DCIS) was commonly treated with breast-conservation therapy (BCT). Local recurrence after BCT is a major concern. The aims of our study were to review the outcomes of DCIS treatment in our patients and to evaluate a nomogram from Memorial Sloan Kettering Cancer Centre (MSKCC) for predicting ipsilateral breast tumour recurrence (IBTR) in our Asian population. MATERIALS AND METHODS: Chart reviews of 716 patients with pure DCIS treated from 1992 to 2011 were carried out. Univariable Cox regression analyses were used to evaluate the effects of the 10 prognostic factors of the MSKCC nomogram on IBTR. We constructed a separate National Cancer Centre Singapore (NCCS) nomogram based on multivariable Cox regression via reduced model selection by applying the stopping rule of Akaike's information criterion to predict IBTR-free survival. The abilities of the NCCS nomogram and the MSKCC nomogram to predict IBTR of individual patients were evaluated with bootstrapping of 200 sets of resamples and the NCCS dataset, respectively. Harrell's c-index was calculated for each nomogram to evaluate the concordance between predicted and observed responses of individual subjects. RESULTS: Study patients were followed up for a median of 70 months. Over 95% of patients received adjuvant radiotherapy. The 5 and 10 year actuarial IBTR-free survival rates for the cohort were 95.5 and 92.6%, respectively. In the multivariate analysis, independent prognostic factors for IBTR included use of adjuvant endocrine therapy, presence of comedonecrosis and younger age at diagnosis. These factors formed the basis of the NCCS nomogram, which had a similar c-index (NCCS: 0.696; MSKCC: 0.673) compared with the MSKCC nomogram. CONCLUSION: The MSKCC nomogram was validated in an Asian population. A simpler NCCS nomogram using a different combination of fewer prognostic factors may be sufficient for the prediction of IBTR in Asians, but requires external validation to compare for relative performance.


Assuntos
Neoplasias da Mama/cirurgia , Carcinoma Intraductal não Infiltrante/cirurgia , Mastectomia Segmentar , Recidiva Local de Neoplasia/diagnóstico , Nomogramas , Ásia/epidemiologia , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Seguimentos , Humanos , Incidência , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Estudos Retrospectivos
6.
Asian Pac J Cancer Prev ; 12(8): 1973-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22292636

RESUMO

BACKGROUND: Human arrest defective 1 protein (ARD1), as a N-terminal acetyltransferase, has been reported to play a crucial role in tumorigenesis, but the results are somewhat controversial. To explore the clinical and pathological significance of ARD1 in breast tumorigenesis, we analyzed ARD1 status in multiple types of breast disease. METHODS: The expression of ARD1 protein was assessed by immunohistochemistry in 356 cases including 82 invasive ductal carcinomas (IDC), 159 fibroadenomas, 66 hyperplasia of mammary glands, 19 inflammatory breast disease, 30 breast cysts, and in 29 postoperative treatment patients. We assessed the relationship of ARD1 protein with clinical and pathological characteristics using χ2 test. RESULTS: ARD1 protein was observed at 61.0% (50/82), 54.7% (87/159), 37.9% (25/66), 36.8% (7/19) in IDC, fibroadenoma, hyperplasia, and inflammation, respectively, and less than 30.0% for breast cyst. Thus, high ARD1 expression correlated with breast cancer (relative risk = 1.32, P < 0.005). Moreover, the level of ARD1 protein in carcinoma patients was distinctly related to lymph node metastasis and ER status, with 94.0% (47/50) as copmpared to 6.0% (3/50) in metastatic and non-metastatic (P < 0.001), and 84.0% (42/50) and 16.0% (8/50) for ER + and ER - (P < 0.01), respectively. In addition, the level of ARD1 appeared to have potential for evaluation of prognosis in breast cancer patients after postoperative therapy. CONCLUSIONS: These results suggest that ARD1 expression may be as a potential target for exploring the mechanism of breast cancer metastasic to lymph nodes and hormone-responsive regulation.


Assuntos
Acetiltransferases/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Acetiltransferases/biossíntese , Acetiltransferases/metabolismo , Adulto , Cisto Mamário/genética , Cisto Mamário/metabolismo , Cisto Mamário/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/secundário , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Feminino , Fibroadenoma/genética , Fibroadenoma/metabolismo , Fibroadenoma/patologia , Humanos , Hiperplasia/genética , Hiperplasia/metabolismo , Hiperplasia/patologia , Imuno-Histoquímica , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Metástase Linfática , Pessoa de Meia-Idade , Acetiltransferase N-Terminal A , Acetiltransferase N-Terminal E , Fenótipo , Período Pós-Operatório , Prognóstico , Regulação para Cima
7.
Avian Dis ; 48(2): 410-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15283430

RESUMO

The characteristics of the pathogenic infectious bursal disease virus (IBDV) that infected avian species other than commercial chickens were largely unknown. In this study, by using in vivo and molecular methods, we had characterized an IBDV isolate (named 94268) isolated from an infectious bursal disease (IBD) outbreak in Malaysian village chickens--the adulterated descendant of the Southeast Asian jungle fowl (Gallus bankiva) that were commonly reared in the backyard. The 94268 isolate was grouped as the very virulent IBDV (vvIBDV) strain because it caused severe lesions and a high mortality rate in village chickens (>88%) and experimentally infected specific-pathogen-free chickens (>66%). In addition, it possessed all of the vvIBDV molecular markers in its VP2 gene. Phylogenetic analysis using distance, maximum parsimony, and maximum likelihood methods revealed that 94268 was monophyletic with other vvIBDV isolates and closely related to the Malaysian vvIBDV isolates. Given that the VP2 gene of 94268 isolate was almost identical and evolutionarily closely related to other field IBDV isolates that affected the commercial chickens, we therefore concluded that IBD infections had spread across the farm boundary. IBD infection in the village chicken may represent an important part of the IBD epidemiology because these birds could harbor the vvIBDV strain and should not be overlooked in the control and prevention of the disease.


Assuntos
Infecções por Birnaviridae/veterinária , Galinhas/virologia , Surtos de Doenças/veterinária , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/epidemiologia , Animais , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Clonagem Molecular , Imuno-Histoquímica/veterinária , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/patogenicidade , Malásia/epidemiologia , Microscopia Imunoeletrônica/veterinária , Coloração Negativa/veterinária , Filogenia , Doenças das Aves Domésticas/virologia , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Análise de Sequência de DNA/veterinária , Inoculações Seriadas , Organismos Livres de Patógenos Específicos
8.
Ann Acad Med Singap ; 32(4): 542-6, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12968561

RESUMO

INTRODUCTION: Severe acute respiratory syndrome (SARS) is a new form of atypical pneumonia caused by a coronavirus. We present the clinical course and chest radiographic findings of a case of SARS with fatal outcome. CLINICAL PICTURE: A 39-year-old Chinese male presented with fever, sore throat and non-productive cough. During his illness, serial chest radiographs showed increasingly severe air-space shadowing in both lungs. TREATMENT AND OUTCOME: The patient was treated with supplemental oxygen, levofloxacin, oseltamivir, ribavirin and methylprednisolone. As his condition worsened, the required ventilatory and inotropic support. He later developed a myocardial infarct and coagulopathy, and succumbed to his illness. CONCLUSION: The reported case mortality of SARS is about 9% worldwide. In Singapore, the mortality is 15.5%. Acute respiratory distress syndrome (ARDS) is believed to be a contributory factor to our patient's demise. We report this case to show the radiographic changes of ARDS in a patient with SARS.


Assuntos
Radiografia Torácica/métodos , Síndrome Respiratória Aguda Grave/diagnóstico por imagem , Adulto , Terapia Combinada , Progressão da Doença , Evolução Fatal , Humanos , Masculino , Insuficiência de Múltiplos Órgãos , Síndrome Respiratória Aguda Grave/terapia , Índice de Gravidade de Doença , Singapura
9.
Singapore Med J ; 44(4): 201-4, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12952033

RESUMO

A new form of atypical pneumonia was reported in the East Asian region beginning from early 2003. This was later termed by the World Health Organisation as Severe Acute Respiratory Syndrome (SARS). The diagnosis of SARS relies on a combination of clinical features and chest radiographic findings. A preliminary review of SARS in Singapore shows chest radiographic findings of patchy airspace shadowing with severe cases progressing to diffuse air-space shadowing. We illustrate these findings with temporal correlation in our case report. As SARS is a contagious, rapidly progressive and potentially fatal condition, early diagnosis is crucial for prompt management and isolation of patients. Recognition of chest radiographic findings aids in the early diagnosis and containment of SARS.


Assuntos
Pulmão/diagnóstico por imagem , Síndrome Respiratória Aguda Grave/diagnóstico por imagem , Adulto , Feminino , Humanos , Vigilância da População , Radiografia , Síndrome Respiratória Aguda Grave/epidemiologia
11.
Artigo em Chinês | MEDLINE | ID: mdl-12019451

RESUMO

N-terminal acetylation is the most common modification in eukaryotic proteins, affecting stability and activity of proteins. NatA is one of the N-terminal acetytransferases in yeast. It is composed of two subunits, NAT1 and ARD1. Defect in one of them leads to loss of activity of NatA. Null mutant of NAT1 in yeast exhibits a variety of phenotypes, including depression of a silent mating type locus (HML), failing to enter G(0) in poor nutrient situations and chromosomes instability. Based on homology of NAT1 between yeast and other organisms, the full-length CDS (coding sequence) of HNAT1 was cloned and sequenced. Result of in situ hybridization in testis of rat showed that expression of NAT1 was high and its expression was different in different phases of spermatogenesis. The gene may play an important role in spermatogenesis.


Assuntos
Acetiltransferases/genética , Sistemas de Transporte de Aminoácidos Neutros/genética , Espermatogênese/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Clonagem Molecular , Células HeLa , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Reação em Cadeia da Polimerase , Especificidade da Espécie
12.
Ann Acad Med Singap ; 31(1): 8-14, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11885502

RESUMO

INTRODUCTION: Elderly patients presenting with backache and vertebral collapse are a diagnostic challenge. Plain X-rays, computed tomography and radionuclide bone scans have not always reliably distinguished between benign and malignant causes. Magnetic resonance imaging (MRI) may be able to do so. MATERIALS AND METHODS: Patients who underwent MRI evaluation for vertebral collapse were retrospectively studied. Over a 21-month period from January 1995 to September 1996, 47 patients with 58 vertebral collapses were studied. Benign and malignant aetiologies were established by serial imaging, clinical outcome and histology. Imaging was performed with T1 and T2-weighted sequences, with contrast enhancement in some patients. Collapsed vertebrae were examined for appearance of marrow on T1 and T2-weighted sequences and after contrast administration, signal intensity of adjacent discs, degree of marrow involvement, involvement of posterior elements, presence or absence of paraspinal mass and end-plate integrity. Agreement between the final and radiological diagnosis was evaluated. RESULTS: There were 36 benign vertebral collapses (20 osteoporotic, 7 post-traumatic, 9 infective) and 22 malignant ones (20 metastatic carcinoma, 2 multiple myeloma). Features which pointed to malignant cause were hypointense marrow on T1-weighted images, marrow enhancement after intravenous contrast, greater than 50% marrow involvement and involvement of posterior elements. Of the vertebral collapses due to infection, 78% showed end-plate disruption. CONCLUSIONS: This study shows that MRI can be used to accurately differentiate between benign and malignant causes of vertebral collapse. Further differentiation between an osteoporotic, traumatic or infective cause can be done with the help of clinical history and evaluation of end-plate integrity.


Assuntos
Fraturas Espontâneas/patologia , Imageamento por Ressonância Magnética/métodos , Osteoporose/patologia , Fraturas da Coluna Vertebral/patologia , Neoplasias da Coluna Vertebral/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Diagnóstico Diferencial , Feminino , Fraturas Espontâneas/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/diagnóstico , Probabilidade , Estudos Retrospectivos , Sensibilidade e Especificidade , Fraturas da Coluna Vertebral/diagnóstico , Neoplasias da Coluna Vertebral/diagnóstico
13.
Sheng Li Xue Bao ; 53(2): 117-22, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11471210

RESUMO

The goal of this study was to clarify the relationship between blood pressure and inducible nitric oxide synthase (iNOS) activity. Different levels of blood pressure were obtained by long-term (six days) intravenous infusion of different concentrations (0.3%-8%) of NaCl solution to normal SD rats. iNOS activity assay and measurement of urinary nitrate/nitrite (UNOx), an index of NO production of the whole body, were carried out by isotope-labeled L-arginine conversion rate measurement and Greiss Reaction respectively. Groups of normotensive and hypertensive rats including normal Wistar rats, normal Sprague-Dawley (SD) rats, high NaCl-induced hypertensive rats (NaHR) and spontaneously hypertensive rats (SHR) were used to detect the changes in iNOS protein under normotension and hypertension by Western blotting. iNOS activity of aorta and kidney tissues and UNOx increased more significantly in hypertensive animals than in the normotensive control ones. Accordingly, iNOS protein in the aortas of NaHR and SHR increased by 149% and 261% respectively. It is suggested that in addition to cytokine and bacterial products etc, blood pressure is also an effective regulatory factor involved in iNOS activation and expression.


Assuntos
Pressão Sanguínea/fisiologia , Óxido Nítrico Sintase/metabolismo , Animais , Hipertensão/induzido quimicamente , Hipertensão/metabolismo , Masculino , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/biossíntese , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Ratos Wistar , Cloreto de Sódio/farmacologia
14.
Am J Hypertens ; 14(6 Pt 2): 68S-73S, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11411768

RESUMO

A large percentage of human hypertensive patients are salt sensitive, referring to the dependence of hypertension on sodium intake, but the cause of the salt sensitivity is not known. Although several mechanisms may contribute to salt-sensitive hypertension, the nitric oxide (NO) system appears to play a major role. Studies in humans and Dahl salt-sensitive (S) rats indicate that NO production is decreased during hypertension. Intravenous L-arginine infusion in Dahl S rats increases NO production and prevents salt-sensitive hypertension. In the Dahl salt-resistant (R) rat, NO production by both inducible NO synthase (iNOS) and neuronal NOS (nNOS) help to prevent salt-sensitive hypertension. Experimental evidence is summarized, indicating that the Dahl S rat has a deficient production of NO by nNOS, although NO production by iNOS appears to moderately decrease salt sensitivity. Other evidence about the importance of NO in salt-sensitive hypertension is reviewed, including the role of the renal NO system.


Assuntos
Hipertensão/induzido quimicamente , Hipertensão/fisiopatologia , Óxido Nítrico/fisiologia , Cloreto de Sódio , Animais , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/fisiologia , Rim/fisiopatologia , Óxido Nítrico Sintase/fisiologia , Sódio/administração & dosagem , Sódio/farmacologia
15.
Am J Physiol Regul Integr Comp Physiol ; 279(6): R2297-303, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11080098

RESUMO

The goal of this study was to determine the role of inducible nitric oxide synthase (iNOS) in the arterial pressure, renal hemodynamic, renal excretory, and hormonal changes that occur in Dahl/Rapp salt-resistant (R) and salt-sensitive (S) rats during changes in Na intake. Thirty-two R and S rats, equipped with indwelling arterial and venous catheters, were subjected to low (0.87 mmol/day) or high (20.6 mmol/day) Na intake, and selective iNOS inhibition was achieved with intravenous aminoguanidine (AG, 12.3 mg. kg(-1). h(-1)). After 5 days of AG, mean arterial pressure increased to 121 +/- 3% control in the R-high Na AG rats compared with 98 +/- 1% control (P < 0.05) in the R-high Na alone rats, and S-high Na rats increased their arterial pressure to 123 +/- 3% control compared with 110 +/- 2% control (P < 0.05) in S-high Na alone rats. AG caused no significant changes in renal hemodynamics, urinary Na or H(2)O excretion, plasma renin activity, or cerebellar Ca-dependent NOS activity. The data suggest that nitric oxide produced by iNOS normally helps to prevent salt-sensitive hypertension in the Dahl R rat and decreases salt sensitivity in the Dahl S rat.


Assuntos
Hipertensão/fisiopatologia , Rim/fisiopatologia , Óxido Nítrico Sintase/metabolismo , Sódio na Dieta , Animais , Pressão Sanguínea , Diurese , Taxa de Filtração Glomerular/efeitos dos fármacos , Guanidinas/farmacologia , Hemodinâmica , Hipertensão/enzimologia , Hipertensão/genética , Rim/irrigação sanguínea , Masculino , Nitratos/urina , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II , Nitritos/urina , Ratos , Ratos Endogâmicos Dahl , Valores de Referência , Circulação Renal
16.
Sheng Li Xue Bao ; 52(2): 103-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11961577

RESUMO

In the present work, we have examined the effects of selective inhibition of the inducible isoform of nitric oxide synthase (iNOS) in rat medulla by aminoguanidine (AG) on the arterial pressure of Dahl salt sensitive (DS), Dahl salt-resistant (DR) and Sprague Dawley (SD) rats by chronic in vivo hemodynamic experiment, the effect of sodium chloride (NaCl) or NaCl plus AG infusion on urinary nitrate/nitrite (urinary NO3/NO2 UNO(x)), the end product of nitric oxide (NO), excretion, glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and plasma renin activity (PRA). Furthermore, an iNOS activity assay was also made. The results showed that AG infusion significantly augmented the pressor response of DS and SD rats to high NaCl (8%) intake, and decreased GFR, ERPF and PRA of DS rats. In addition, in DS rats, renal medullary interstitial administration of high NaCl significantly elevated the iNOS activity of renal tissue, especially inner medulla and outer medulla, and greatly increased UNO(x) excretion. Therefore, it is concluded that inducible NOS is an important modulator of blood pressure in case of NaCl-induced hypertension.


Assuntos
Pressão Sanguínea/fisiologia , Medula Renal/enzimologia , Óxido Nítrico Sintase/fisiologia , Animais , Guanidinas/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II , Ratos , Ratos Endogâmicos Dahl , Ratos Sprague-Dawley , Renina/metabolismo , Cloreto de Sódio/farmacologia
17.
Hypertension ; 33(1 Pt 2): 456-61, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9931147

RESUMO

The goal of this study was to determine the role of neuronal nitric oxide synthase (nNOS) in the arterial pressure, renal hemodynamic, and renal excretory changes that occur in Dahl salt-resistant (DR) and salt-sensitive (DS) rats during changes in Na intake. Fifty-three DR and DS rats/Rapp strain of 7 to 8 weeks of age with indwelling arterial and venous catheters were subjected to low (0.87 mmol/d) or high (20.6 mmol/d) Na intake beginning 2 days before the start of the control period. Measurements were made during a 5-day control period followed by a 5-day period of nNOS inhibition with intravenous 7-nitroindazole (7NI, 1.67 mg. kg-1. h-1) or vehicle infusion. After 5 days of 7NI, mean arterial pressure increased to 120+/-6% control in the DR-high Na, 7NI rats compared with 98+/-1% control (P<0.05) in the DR-high Na alone rats. After 5 days of 7NI, DS-high Na rats, which had a control arterial pressure 31 mm Hg higher than the comparable DR rats, increased their arterial pressure to 114+/-3% control, which was not significantly different from the DS-high Na alone pressure of 110+/-2% control. No significant changes occurred in glomerular filtration rate, effective renal plasma flow, urinary Na excretion, or urine volume because of 7NI. However, plasma renin activity decreased significantly in DR and DS rats on low Na intake with 7NI infusion. The data demonstrate that the highly salt-resistant DR rat became salt-sensitive during nNOS inhibition with 7NI. However, the arterial pressure of the DS rat was not affected by 7NI. This suggests that nitric oxide produced by nNOS in the DR rat normally helps to prevent salt-sensitive hypertension and that low functional levels of nNOS in the DS rat may contribute to its salt-sensitivity.


Assuntos
Dieta Hipossódica , Inibidores Enzimáticos/farmacologia , Hipertensão/fisiopatologia , Indazóis/farmacologia , Óxido Nítrico Sintase/metabolismo , Sódio na Dieta , Animais , Pressão Sanguínea/efeitos dos fármacos , Taxa de Filtração Glomerular/efeitos dos fármacos , Hipertensão/enzimologia , Hipertensão/genética , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo I , Ratos , Ratos Endogâmicos Dahl , Circulação Renal/efeitos dos fármacos , Renina/sangue , Sódio/urina
18.
Can J Physiol Pharmacol ; 73(7): 1065-9, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8846402

RESUMO

Human adrenomedullin (hADM) is a newly isolated peptide with hypotensive activity in normotensive rats. The objective of this study was to investigate the effect of hADM(13-52) on hypertensive animals. hADM(13-52) induced a dose-dependent decrease in the blood pressure of spontaneously hypertensive rats and renal hypertensive rats. This result suggests that hADM is a novel antihypertensive peptide. In isolated rat aortic arteries, hADM(13-52) produced nitric oxide dependent relaxation and inhibited endothelin 1 and angiotensin II release. These in vitro effects may represent the molecular mechanisms underlying the hypotensive action of hADM in vivo.


Assuntos
Anti-Hipertensivos/farmacologia , Hipertensão/fisiopatologia , Fragmentos de Peptídeos/farmacologia , Vasodilatadores/farmacologia , Adrenomedulina , Angiotensina II/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Endotelinas/metabolismo , Humanos , Técnicas In Vitro , Masculino , Óxido Nítrico/fisiologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ratos Wistar
19.
Chin Med J (Engl) ; 107(10): 745-9, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7835100

RESUMO

In present study, we examined the effects of NG-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), and/or methylene blue (MB), a blocker of guanylate cyclase on the vasodilator response of isolated rat arteries including aorta and mesenteric artery to calcitonin gene-related peptide (CGRP) by in vitro vasoconstriction experiment, and the effect of LNNA on the depressor action of CGRP by in vivo hemodynamic experiment. Furthermore, the effect of CGRP on NOS activity and cyclic guanylate monophosphate (cGMP) content were also examined by NOS activity assay and radioimmunoassay (RIA), respectively. The results showed that LNNA and/or MB significantly decreased, but not abolished, the vasodilator response of isolated rat aorta and mesenteric artery to CGRP. The depressor effect of CGRP on LNNA-induced hypertensive rats (LHR) was obviously weaker than that on spontaneously hypertensive rats (SHR), renal hypertensive rats (RHR) and normotensive rats (NWR). In addition, CGRP (0.5 nmol/kg) increased the NOS activity of rat aorta tissue by 1.3 times (P < 0.05) and resulted in an increase of cGMP content of aorta (1.27 times, P < 0.05) and myocardium (1.38 times, P < 0.05). The results suggested that NO is involved in the action of CGRP.


Assuntos
Anti-Hipertensivos/farmacologia , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Óxido Nítrico/farmacologia , Vasodilatadores/farmacologia , Animais , Aorta/efeitos dos fármacos , Arginina/análogos & derivados , Arginina/farmacologia , Técnicas In Vitro , Masculino , Nitroarginina , Ratos , Ratos Endogâmicos SHR , Ratos Wistar
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