Biomedical subjects

Ya-li Zhao

Publications and source records attributed to Ya-li Zhao.

6 recordsLinked to original sources

PubMed2006

[The mutation R672H in SCN4A gene exists in Chinese patients with hypokalaemic periodic paralysis].

OBJECTIVE: Mutation screening was performed on two Chinese families with HOKPP to locat the corresponding mutations and to specify the clinical features associated with the mutation. METHODS: Target-exon PCR and direct sequencing were used to screen mutation in the CACNA1S and SCN4A gene of all numbers of the two families. The clinical features of patients were summary. RESULTS: A heterozygous point mutation 2015G-->A causing R672H in the SCN4A was found in five patients and five normal relatives of the two families. Features of R672H mutation are incomplete penetrance, especially non-penetrance of phenotype in women and potassium is effective, but acetazolamide is not. CONCLUSION: The SCN4A R672H mutation exists in the Chinese family with HOKPP.

Adolescent↗

PubMed2005

Age-related decrease in expression of peroxisome proliferator-activated receptor alpha and its effects on development of dyslipidemia.

BACKGROUND: Ageing is associated with increased incidence of dyslipidemia. To investigate potential molecular mechanisms, the effects of age and fibrate administration on peroxisome proliferator-activated receptor alpha (PPARalpha) expression in livers of young and old rats were studied. METHODS: A total of 16 young (2-month-old) and 16 old rats (24-month-old) were randomly assigned to a control group and fenofibrate group (fenofibrate in a total therapeutic dosage of 0.5% in ratio to each treated rat weight in 14 days). RT-PCR was applied to evaluate hepatic mRNA expression of PPARalpha and its target genes. Western blotting was used to determine PPARalpha protein level in liver tissue. RESULTS: When compared with 2-month-old rats, the liver tissue from 24-month-old rats showed reduced expression of PPARalpha mRNA (52%, P < 0.05) and protein (109%, P < 0.01). Consequently, the mRNA levels of PPAR target genes, LPL, ACO, ACS and CPT-1 were markedly lowered by 19%, 8%, 13% and 9% respectively, and apoCIII increased by 24% in livers from 24-month-old rats, compared with values obtained from 2-month-old rats (P < 0.05). Fenofibrate therapy significantly lowered plasma triglyceride and total cholesterol levels in old rats, accompanied with improvement in hepatic expression of genes, including LPL, ACO, ACS, CPT-1 and apoCIII, but no change was found in PPARalpha expression in livers from either 24-month or 2-month-old rats. CONCLUSIONS: The decrease in the hepatic PPARalpha expression is probably directly related to the lipid metabolic disturbances observed in old animals. The beneficial effects of fenofibrate administration in old rats suggests that fibrates may be useful for treating lipid disturbances in old people.

Aging↗

PubMed2005

[Effects of interleukin-10 on expression of inflammatory mediators and anti-inflammatory mediators during acute lung injury in rats].

OBJECTIVE: To investigate the effects of interleukin-10 (IL-10) on expression of inflammatory mediators and anti-inflammatory mediators during acute lung injury (ALI). METHODS: Rat model of ALI was reproduced by intratracheal instillation of lipopolysaccharide (LPS) in a dose of 10 mg/kg. Fifty-four male SD rats were randomly divided into control group, LPS group and LPS+IL-10 group, with 18 rats in each group (6 rats at 2, 6 and 24 hours respectively). Arterial gas analysis, the total protein concentration in bronchoalveolar lavage fluid (BALF), the total cell counts and classification in BALF, the lung coefficient, lung pathology were examined. Reverse transcription-polymerase chain reaction (RT-PCR) method was used to determine the expression of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and IL-1ra mRNA in lung tissue. RESULTS: (1)In LPS group the partial pressure of oxygen in artery (PaO(2)) was progressively decreased, while the lung coefficient, the total protein concentration, the total cell counts in BALF were greatly increased, and lung pathology showed severe polymorphonuclear leukocytes infiltration with bleeding and hyaline membranes formation. In LPS+IL-10 group the values of all above parameters were alleviated. (2)In LPS group TNF-alpha mRNA expression peaked at 2 hours, then decreased sharply; IL-1beta mRNA expression greatly increased at 2 hours, peaked at 6 hours, then decreased; IL-1ra mRNA expression increased and peaked at 6 hours, remaining higher than control group at 24 hours. IL-10 inhibited TNF-alpha mRNA and IL-1beta mRNA expression but showed no effect on IL-1ra mRNA expression. CONCLUSION: (1)ALI is characterized by overwhelming expression of TNF-alpha mRNA, IL-1beta mRNA, while the expression of IL-1ra mRNA is much delayed than TNF-alpha mRNA and IL-1beta mRNA. It suggests that there is an imbalance between inflammatory/anti-inflammatory mediators in the early phase of ALI. (2)IL-10 can inhibit the expression of inflammatory mediators and has no effect on the expression of anti-inflammatory mediators, thus it contributes to the balance between them, ameliorating ALI in rats.

Acute Lung Injury↗

PubMed2004

Angiotensin II induced upregulation of G alpha q/11, phospholipase C beta 3 and extracellular signal-regulated kinase 1/2 via angiotensin II type 1 receptor.

BACKGROUND: The role of the G alpha q/11-mediated signal transduction pathway in angiotensin II (AngII) induced cardiac hypertrophy remains unclear. This study was to investigate the role of the G alpha q/11 signal transduction pathway in the development of cardiac hypertrophy in 2K1C hypertensive rats and in cultured neonatal rat ventricular myocytes (NRVMs) and to elucidate the effects of the pathway on AngII induced cardiac hypertrophy. METHODS: Renal hypertension was induced in 2K1C hypertensive rats by placing a silver clip around the left renal artery. At 8 weeks after operation, the systolic blood pressure, the ratio of left ventricular weight to body weight (LV/BW), and the concentration of AngII in the heart were measured. The protein levels of G alpha q/11 and extracellular signal-regulated kinase 1/2 (ERK1/2) were assayed by Western blot analysis, and the activity of phospholipase C (PLC) in the myocardium was detected using [(3)H]-PIP2 as a substrate. Changes in [(3)H]-leucine incorporation and in the protein levels of the signal molecules G alpha q/11, PLC beta 3, and ERK1/2 were measured after NRVMs were stimulated with 10(-7) mol/L AngII. RESULTS: The protein levels of G alpha q/11 and ERK1/2 in the hearts of 2K1C rats increased by 35.8% and 31.9%, respectively, compared with the sham group. The PLC activity in the 2K1C group was also significantly increased (P < 0.05). The levels of G alpha q/11, PLC beta 3, and ERK1/2 increased significantly after NRVMs were stimulated by AngII. The upregulation of G alpha q/11, PLC beta 3 and ERK1/2 in NRVMs occurred prior to [(3)H]-leucine incorporation increases, and could be inhibited with losartan. CONCLUSION: AngII can initiate cardiac hypertrophy and upregulate signal molecules in the G alpha q/11-mediated signal transduction pathway, such as G alpha q/11, PLC beta 3 and ERK1/2, at both tissue and cellular levels.

Angiotensin II↗

PubMed2004

[Effects of 2450 MHz microwave on long-term potentiation of hippocampus and lipofuscin contents in rat brain].

OBJECTIVE: To study the mechanism of the effects of microwave on learning and memory. METHOD: Long-term potentiation (LTP) of hippocampus induced potential and lipofuscin content in rat brain were studied. After irradiated by a 2450 MHz microwave, rats hippocampus induced potential in vivo was recorded and lipofuscin content in the brain was measured by fluorospectrophotometry. RESULT: Continuous microwave with 10-25 mW/cm2 intensity could inhibit the amplitude of the population spike (PS) of weak and strong stimuli induced LTP with an intensity-effect relationship. At 25 mW/cm2, lipofuscin content was significantly higher than control and 10 mW/cm2 group (P<0.05). CONCLUSION: Continuous microwave with 10-25 mW/cm2 intensity impairs learning and memory by restraining hippocampus LTP and brain lipofuscin content.

Animals↗

PubMed2003

[Effects of microwave irradiation on ATPase activity and voltage dependent ion channel of rat hippocampus cell membrane].

OBJECTIVE: To study the effect of microwave irradiation on hippocampus cell. METHOD: Changes of ATPase activity and voltage dependent ion channel of hippocampus cell membrane were observed in mice exposed to 2 450 MHz microwave irradiation of 10 mW/cm2 from a physical therapy machine. Histochemical method and patch clamp method were used to determine the activity of Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase and voltage dependent Na+, K+, Ca2+ channels respectively. RESULT: 1) Na+, K(+)-ATPase activity of microwave irradiated mice showed no significant change as compared with the control, but the activity of Ca2+, Mg(2+)-ATPase decreased significantly (P< 0.05); 2) In microwave irradiated mice, Na+, K+, Ca2+, current inducement rate in hippocampus neuron decreased significantly, the membrane voltage of Na+ current peak shifted to depolarization, and the attenuation rate of Na+ current and current A inducement rate decreased significantly as compared with control mice. CONCLUSION: Irradiation of 2 450 MHz microwave at a doze of 10 mW/cm2 was not fatal to mice hippocampus cell. But Ca2+, Mg(2+)-ATPase activity of hippocampal cell membrane and voltage dependent Na+, K+, Ca2+ ion channel of hippocampal nervous were affected which would affect study and memory.

Animals↗