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Biomedical subjects

J He

Publications and source records attributed to J He.

At least 199 records · Page 11Linked to original sources
PubMed1999

A class of neuroD-related basic helix-loop-helix transcription factors expressed in developing central nervous system in zebrafish.

Neuronal basic helix-loop-helix (bHLH) transcription factors such as neuroD and neurogenin have been shown to play important roles in neuronal development. In the present study, several distinct bHLH DNA fragments were isolated from the zebrafish genomic DNA by a pair of degenerate polymerase chain reaction (PCR) primers deduced from the conserved bHLH domains of neuroD and neurogenins. Based on the bHLH fragments, three complete neuroD-related cDNA clones, including complete coding regions, ndr1a, ndr1b, and ndr2 (ndr for neuroD related), were isolated and assembled by 5' and 3' rapid amplification of cDNA ends (RACE). A phylogenetic analysis indicated the presence of four groups of neuroD-related genes in the neuroD subfamily in vertebrates: neuroD, ndr1a/ndr1b/MATH-2, ndr2/NDRF, and neuroM/MATH3. Expression of the newly isolated neuroD-related genes was examined by reverse transcriptase (RT)-PCR and whole-mount in situ hybridization. Unlike neuroD, which was expressed broadly in primary neurons during early zebrafish development starting from 10 h postfertilization (hpf), expression of ndr1a and ndr1b started relatively late (around 22 hpf) and was restricted to the olfactory system: olfactory bulbs in the telecephalon (ndr1a and ndr1b) and olfactory organs (ndr1b) starting around 22 hpf. Although a faint ndr2 mRNA signal was detected by RT-PCR in early embryos, no ndr2 mRNA was detected by whole-mount in situ hybridization in embryos up to 72 hpf, suggesting that it is expressed rather late. Our observations suggest that the two novel neuroD-related genes, ndr1a and ndr1b, are involved in the development of the olfactory system and perhaps contribute to its functional complexity.

Amino Acid Sequence↗
PubMed1999

Fast skeletal muscle-specific expression of a zebrafish myosin light chain 2 gene and characterization of its promoter by direct injection into skeletal muscle.

A zebrafish myosin light chain 2 cDNA clone was isolated and characterized. Sequence analysis of the clone revealed a high homology with the mammalian and avian genes encoding the fast skeletal muscle isoform, MLC2f. In situ hybridization and Northern blot hybridization analyses indicated that the zebrafish MLC2f mRNA is expressed exclusively in the fast skeletal muscle. Ontogenetically, the MLC2f mRNA appears around 16 hours postfertilization (hpf) in the first few well-formed anterior somites. At later stages, the MLC2f mRNA can also be detected in fin buds, eye muscles, and jaw muscles. To develop a useful model system for analyzing muscle gene regulation, the promoter of the zebrafish MLC2f gene was isolated and linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The MLC2f/CAT chimeric constructs were analyzed by direct injection into the zebrafish skeletal muscle, and significant CAT activity was observed; in contrast, little or no CAT activity was generated from a similarly injected prolactin gene promoter/CAT gene construct. Within the 1 kb of the MLC2f promoter region, several MEF2-binding sites and E-boxes were identified, suggesting that MLC2f can be regulated by muscle transcription factors MEF2 and myogenic bHLH proteins. A 5' deletion analysis indicated that the proximal 79 nucleotides from the transcription start site, which contains a single MEF2-binding site, is sufficient to drive a high level of CAT activity in injected muscle. Internal deletion of the MEF2 element in the -79-bp construct caused an 80% decrease in CAT activity, whereas internal deletion of the same MEF2 element in a -1044-bp construct had no effect on induced CAT activity. These observations suggest that an MEF2 element is important to activate the MLC2f gene in muscle cells, and the effect of loss of the proximal MEF2 element can be compensated for by the presence of the upstream MEF2 elements. This study also demonstrated that direct injection of DNA into skeletal muscle is a valid and valuable approach to analyze muscle gene promoters in the zebrafish.

Amino Acid Sequence↗
PubMed1999

Kinetics of cytokine production in the cornea and trigeminal ganglion of C57BL/6 mice after corneal HSV-1 infection.

To investigate the role of cytokines in the pathogenesis of acute herpetic keratitis (HK), we examined the kinetics of cytokine expression in the corneas and the trigeminal ganglia (TG) of C57BL/6Cr (B6) mice after herpes simplex virus type 1 (HSV-1) infection and observed the influence of the targeted disruption of interferon-gamma (IFN-gamma) gene on the clinical course of HK and/or viral clearance. Following corneal infection with HSV-1 Amakata strain, all corneas developed a typical dendritic keratitis. Quantitative analysis using enzyme-linked immunosorbent assay (ELISA) revealed that the expression of interleukin-1alpha (IL-1alpha), IL-5, IL-6, and IFN-gamma in corneas and TGs significantly elevated immediately after infection, peaked between days 2 and 7 postinfection (p.i.), and then diminished. One exception was IFN-gamma, whose expression significantly persisted in the TGs until day 30 p.i. An additional experiment using IFN-gamma-/- (gko) mice revealed that there was no significant difference in the peak level of viral replication in corneas and TGs between gko and B6 mice, although gko mice showed a significant delay of virus clearance in both corneas and TGs (p < 0.005) and higher mortality rate than B6 mice after HSV-1 infection (p < 0.01). These data suggest that the production of proinflammatory cytokines closely correlates with the pathogenesis of HK, and that IFN-gamma plays an important role in enhancing viral clearance from the cornea and TG.

Animals↗
PubMed1999

What is the role of dietary sodium and potassium in hypertension and target organ injury?

There is substantial evidence from both observational epidemiology studies and randomized controlled trials that dietary intake of sodium and potassium is important in the etiology of hypertension. However, the direct evidence for a direct link between dietary sodium and potassium and risk of cardiovascular and renovascular events is limited. Epidemiological studies should be designed to examine the relationship between dietary intake of sodium and potassium and risk of stroke, coronary heart disease, left ventricular hypertrophy, and renal disease in a prospective manner. In these studies, dietary intake of sodium and potassium should be estimated using multiple 24-hour urine collections. These studies should be focused on African Americans because they are at a disproportionately high risk of developing hypertension and blood pressure-related vascular disease. Moreover, this group has been underrepresented in most previous epidemiological studies.

Black or African American↗
PubMed1999

Apoptosis induced by infection of primary brain cultures with diverse human immunodeficiency virus type 1 isolates: evidence for a role of the envelope.

Apoptosis of neurons and astrocytes is induced by human immunodeficiency type 1 (HIV-1) infection in vitro and has been demonstrated in brain tissue from patients with AIDS. We analyzed a panel of diverse HIV-1 primary isolates for the ability to replicate and induce neuronal and astrocyte apoptosis in primary human brain cultures. Apoptosis was induced three- to eightfold by infection with the blood-derived HIV-1 isolates 89.6, SG3, and ADA. In contrast, the brain-derived HIV-1 isolates YU2, JRFL, DS-br, RC-br, and KJ-br did not induce significant levels of apoptosis. The ability of HIV-1 isolates to induce apoptosis was independent of their replication capacity. Studies of recombinant chimeras between the SG3 and YU2 viruses showed that replacement of the YU2 Env with the SG3 Env was sufficient to confer the ability to induce apoptosis to the YU2 virus. Replacement of the Env V3 regions alone largely conferred the phenotypes of the parental clones. The SG3 Env used CXCR4 and CCR3 as coreceptors for virus entry, whereas YU2 used CCR5 and CCR3. The V3 regions of SG3 and YU2 conferred the ability to use CXCR4 and CCR5, respectively. In contrast, the 3' region of Env, particularly the C3V4 region, was required in conjunction with the V3 region for efficient use of CCR3. These results provide evidence that Env is a major determinant of neurodegenerative mechanisms associated with HIV-1 infection in vitro and raise the possibility that blood-derived viruses which emerge during the late stages of disease may affect disease progression in the central nervous system.

Animals↗
PubMed1999

The effect of chronic coffee drinking on blood pressure: a meta-analysis of controlled clinical trials.

We sought to assess the effect of coffee consumption on blood pressure in humans. Our data sources included a MEDLINE search of the literature published before December 1997, bibliography review, and expert consultation. We selected controlled trials in which coffee consumption was the only difference between the intervention and control groups, mean blood pressure change was reported for each group or period, and treatment lasted for >24 hours. Of 36 studies initially identified, 11 (522 participants) met these inclusion criteria. Information on sample size, study design, participant characteristics (gender, race, age, baseline blood pressure, and antihypertensive medications), and treatment results were abstracted by 3 reviewers using a standardized protocol. Treatment effect of coffee consumption on blood pressure was estimated with the use of a random-effects model. In the 11 trials, median duration was 56 days (range, 14 to 79 days), and median dose of coffee was 5 cups/d. Systolic and diastolic blood pressure increased by 2.4 (range, 1.0 to 3.7) mm Hg and 1.2 (range, 0.4 to 2.1) mm Hg, respectively, with coffee treatment compared with control. Multiple linear regression analysis identified an independent, positive relationship between cups of coffee consumed and subsequent change in systolic blood pressure, independent of age of study participants and study design characteristics. The effect of coffee drinking on systolic and diastolic blood pressure was greater in trials with younger participants. Our findings provide support for a relationship between coffee consumption and higher blood pressure. Trials of coffee cessation of longer duration and in persons with hypertension should be performed.

Adolescent↗
PubMed1999

Analysis of cyclin dependent kinase inhibitors in malignant astrocytomas.

The cyclin-dependent kinase inhibitors p16, p21, and p27 in human brain, and brain tumors were examined to explore clinicopathologic correlations. Western analysis and immunohistochemistry was performed and correlated retrospectively with the patients clinical characteristics. A trend was found between increased progression-free survival and p27 expression. There was no correlation between p27 expression and age or gender. The expression of p27 in malignant gliomas may have prognostic value. In addition, an investigation of the therapeutic benefit of overexpression of this cyclin-dependent kinase inhibitor is warranted given reports of diminished malignant potential of tumors expressing p27.

Adolescent↗
PubMed1999

Evaluation of a rapid test for the detection of antibodies to human immunodeficiency virus type 1 and 2.

Hema-Strip HIV-1/2 is a one-step rapid test for the detection of anti-HIV-1/2 antibodies in whole blood. The test requires no expensive equipment and the results are available within 10-15 min. Using 72 known HIV-1 positive samples and 780 high-risk prisoners, the sensitivity and specificity of Hema-Strip HIV-1/2 was found to be comparable to microparticle enzyme immunoassay (MEIA). The data also indicated that Hema-Strip HIV-1/2 is an effective alternate testing system to conventional ELISA where the use of ELISA is not suitable and the result of the HIV testing is needed urgently.

Evaluation Studies as Topic↗
PubMed1999

Elevated systolic blood pressure as a risk factor for cardiovascular and renal disease.

AIM: To review published literature on the relationship between systolic blood pressure and risk of cardiovascular and renal disease. DATA: identification Studies were retrieved using the MEDLINE database, bibliographies, and the authors' reference files. STUDY SELECTION: Prospective cohort studies and randomized controlled trials which were published in English-language journals. DATA EXTRACTION: All retrieved publications were reviewed by the two authors. Information on sample size, duration, study design, antihypertensive medication, participant characteristics and outcomes was abstracted for randomized controlled trials which reported reductions in systolic blood pressure during intervention. DATA SYNTHESIS: Results from several prospective cohort studies indicate that the association between systolic blood pressure and risk of coronary heart disease, stroke and end-stage renal disease is continuous, graded, and independent. Furthermore, they suggest that the association of systolic blood pressure with these outcomes is stronger than that of diastolic blood pressure. Pooling of the data available from randomized controlled trials indicates that an average reduction of 12-13 mmHg in systolic blood pressure over 4 years of follow-up is associated with a 21% reduction in coronary heart disease, a 37% reduction in stroke, a 25% reduction in total cardiovascular mortality, and a 13% reduction in all-cause mortality. CONCLUSION: Observational epidemiologic studies and randomized controlled trials have demonstrated that systolic blood pressure is an independent and strong predictor of risk of cardiovascular and renal disease.

Adult↗
PubMed1999

Effect of metalloproteinase inhibitor on corneal cytokine expression after alkali injury.

PURPOSE: Interleukin (IL)-1alpha and IL-6 levels in the cornea are greatly elevated during the early stages after an alkali burn in mice. The authors investigated the effect of synthetic inhibitor of matrix metalloproteinase (SIMP) on the expression of inflammatory cytokines in alkali-burned murine corneas and evaluated the clinical appearance of the eyes. METHODS: After 0.5N NaOH-alkali burns to 400 corneas of ICR mice, 200 received 400 microg/ml of SIMP topically 4 times a day while 200 corneas were similarly treated with vehicle only. At days 4, 7 and 14 after injury, each cornea was assigned a clinical score for corneal opacity, corneal epithelial defect, hyphema and cataract. Extracts of injured corneas in each group were then assayed for cytokine production using ELISA systems for IL-1alpha, IL-1beta, IL-6 and tumor necrosis factor-alpha (TNF-alpha). RESULTS: The levels of IL-1alpha, IL-1beta and IL-6 were significantly lower in the SIMP-treated group than in the vehicle-treated group 7 days after the burn. However, levels of these cytokines were similar in the SIMP and non-SIMP groups at days 4 and 14. Levels of TNF-alpha did not differ between both groups at any postinjury time. In the SIMP-treated corneas, there was less opacification and hyphema formation and epithelial regeneration was faster. CONCLUSIONS: Topical application of SIMP in alkali-burned murine corneas reduced the expression of IL-1alpha, IL-1beta, and IL-6 and lessened the severity of the injury.

Animals↗
PubMed1999

Potassium in preventing and treating high blood pressure.

Our objective was to assess the effects of supplementation with oral potassium on blood pressure (BP) in humans, using pooled analysis of randomized, controlled trials. Results from 33 randomized, controlled trials (2,609 participants) in which potassium supplementation was the only difference between the intervention and control conditions were used. Information on sample size, duration, study design, potassium dose, participant characteristics, and treatment results was independently obtained by the authors using a standardized protocol. The findings from each trial were pooled after weighting the results for individual studies by the inverse of its variance. Using a random-effects model, potassium supplementation was associated with a significant reduction in mean (95% confidence interval) systolic and diastolic BP of -4.44 (range, -2.53 to -6.36) and -2.45 (range, -0.74 to -4.16) mm Hg, respectively. After exclusion of a trial with extreme results, potassium supplementation was still associated with a significant reduction in mean (95% confidence interval) systolic and diastolic BP of -3.11 (range, -1.91 to -4.31) and -1.97 (range, -0.52 to -3.42) mm Hg, respectively. The BP effects of potassium administration appeared to be enhanced in studies where participants were concurrently exposed to a high intake of sodium. Increased potassium intake should be included as a recommendation for prevention and treatment of hypertension, especially in those who are unable to reduce their intake of sodium.

Adolescent↗
PubMed1999

[Study on the relationship between epidermal growth factor and fetal growth retardation].

OBJECTIVE: To evaluate the significance of epidermal growth factor (EGF) in the development of fetal growth retardation (IUGR). METHODS: EGF concentrations in amniotic fluid, maternal and fetal blood from 86 pregnant women in the third-trimester were determined by radioimmunoassay (RIA). These subjects were divided into control, large-for gestational age (LGA) group and IUGR group according to neonatal birth weights. EGF concentrations in blood samples taken from umbilical vein and artery of 11 controls were also analyzed. RESULTS: No significant differences of EGF concentrations existed in amniotic fluid, maternal and fetal blood between control and LGA group (P > 0.2 for all). Compared to the control, EGF concentration of IUGR group in amniotic fluid decreased but those in maternal and fetal blood increased significantly (P < 0.05 for all). EGF concentration of cord serum in IUGR group was significantly higher than that in LGA group (P < 0.05), but no differences of EGF levels in amniotic fluid and maternal blood existed between the two groups (P > 0.05, for all). EGF in blood samples taken from umbilical vein and artery were at the same level (P > 0.1). CONCLUSIONS: EGF in amniotic fluid, maternal and fetal blood may originate from different sources, and EGF may play a role in the development of IUGR.

Adult↗
PubMed1999

[Review of external therapy for internal diseases in Ming yi lei an (Classified Medical Records of Famous Doctors)].

External therapy was applied for internal diseases in 78 case records in Classified Medical Records of Famous Doctors, including 19 kinds of external therapies for 41 categories of internal disease involving 40 famous doctors. The external therapy embodied the principle of "treatment according to differential diagnosis of Zhen "of TMC", "regular treatment", "contrary treatment" and multiple routes of administration were given in accordance with the differentiation, demonstrating that ancient doctors paid high attention to external therapy for internal diseases.

China↗
PubMed1999

[Cerebrovascular diseases complications after cardiac surgery].

OBJECTIVE: To assess morbidity, mortality, sorts, risk factors, prevention and treatment of patients with cerebrovascular disease complication (CVDC) undergoing cardiopulmanary bypass (CPB). METHODS: We retrospectively reviewed 10,173 cases of CPB surgery, analysed risk factors of CVDC after CPB surgery in comparison with controls. RESULTS: After CPB surgery, the general morbidity of neurological complications (NC) was 1.44% (146/10,173), of which CVDC accounted for 59.58% (87/146). In the CVDC group, cerebral embolism accounted for 39.09%, cerebral infarction 28.74%, cerebral haemorrhage 11.49%, prosthetic valve endocarditis (PVE) with CVD 10.34%, and others 10.35%. Death occurred in 44 patients of the NC group, in which CVDC went to 47.72% (21/44). Aortic clump time and CPB time were greatly longer in the CVDC group than controls (P < 0.01). CONCLUSIONS: The main postoperative neurological complications after CPB surgery are CVDC, most of which are ischemic cerebrovascular disease. Postoperative CVDC correlates with longer aortic clump time and CPB time during the operation.

Adolescent↗
PubMed1999

[Collagen expression of intra-acinar pulmonary arteries and right ventricle and intervention of Radix Astragali in rats with hypoxic pulmonary hypertension].

OBJECTIVE: To investigate the collagen expression effect of intra-acinar pulmonary arteries and the right ventricle and to observe the intervention effect of Radix Astragali in rats with hypoxic pulmonary hypertension. METHODS: Wistar male rats were divided into three groups: hypoxia group, which was fed in hypoxic environment (oxygen concentration was 9%-12%) under normal atmospheric pressure for three weeks (12 hours every day); intervention group, which was abdomenly injected with Radix Astragali and fed in the same environment as hypoxia group; and control group, which was fed in normal environment. Pulmonary artery pressure and cardiac output of the right ventricle were measured with catheterization and Fick's method. Protein expression of collagen in intra-acinar pulmonary arteries was assessed with histopathologic method. mRNA expressions of collagen in the right ventricle, and endothelin-1 and nitric oxide synthase in lung tissue were evaluated by RT-PCR technique. RESULTS: Compared with those in control group, pulmonary artery pressure and protein expression of collagen in intra-acinar pulmonary arteries and mRNA expression of type I collagen in the right ventricle and endothelin-1 in lung tissue were obviously increased in hypoxia group (mean pulmonary artery pressure: (24.8 +/- 3.6) mm Hg vs (18.8 +/- 1.7) mm Hg, P < 0.01; protein expression of collagen: (20.4 +/- 4.5) AU vs (3.4 +/- 1.1) AU (P < 0.01), but mRNA expression of nitric oxide synthase in lung tissue was declined. Compared with the data obtained in hypoxia group, cardiac output and mRNA expression of nitric oxide synthase in lung tissue were raised in intervention group (cardiac output: [(141 +/- 20) ml/min vs (118 +/- 40) ml/min, P < 0.01], but protein expression of collagen in intra-acinar pulmonary arteries and mRNA expression of type I collagen in the right ventricle and endothelin-1 in lung tissue were markedly decreased (protein expression of collagen: [(5.6 +/- 1.2) AU vs (20.4 +/- 4.5) AU, P < 0.001]. CONCLUSION: Changes of collagen expression in intra-acinar pulmonary arteries and right ventricle are one of the most important features in remodeling of pulmonary arteries and right ventricle in hypoxic pulmonary hypertension. Radix Astragali can partly inhibit the remodeling of pulmonary arteries and right ventricle, and regulate mRNA expression of endothelin-1, nitric oxide synthase, and collagen, thus contributing to the treatment of hypoxic pulmonary hypertension.

Animals↗
PubMed1999

Relationship between bone mineral density and polymorphism of the estrogen receptor gene in healthy postmenopausal women in China.

OBJECTIVE: To investigate the possible relationship between bone mineral density and polymorphism of the estrogen receptor (ER) gene in Shanghai healthy postmenopausal women. METHODS: 250 unrelated healthy postmenopausal women were selected for bone mineral density (BMD) determination by Dual energy X-ray absorptiometry (DEXA) and polymorphism of estrogen receptor gene analyses by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Pvu II polymorphisms of ER gene was associated with low Troch BMD (P = 0.0153) while there was no significant relationship between Xba I polymorphism of ER gene and BMD at any of skeletal sites included in the present study, and the combination of Pvu II and Xba I polymorphisms of ER gene was significantly associated with both low Lumbar 2-4 (P = 0.0369) and Troch (P = 0.0384) BMD. Multiple stepwise regression analysis also indicated that two combined polymorphisms were correlated significantly with Lumbar 2-4 BMD (P = 0.0254) while this correlation was not revealed at any other skeletal sites. CONCLUSION: There is significant relationship between the polymorphism of ER gene and both Lumbar 2-4 BMD and Troch BMD. It is significant to explore the pathogenesis of osteoporosis and to prevent the development of osteoprosis by use of molecular genetics.

Absorptiometry, Photon↗
PubMed1999

[Effect of caoguo zhimu decoction on N-methyl-D-aspartate receptor gene expression of epileptic kindling model in rats].

OBJECTIVE: To explore the effect of Caoguo Zhimu decoction (CGZMD) on N-methyl-D-aspartate (NMDA) receptor gene expression of epileptic model on rat brain. METHODS: Adopting the pentylenetetrazol (PTZ) kindling model to observe the NMDAR1 mRNA gene expression by situs hybridization. RESULTS: After 28 days of CGZMD treatment, the NMDAR1 mRNA gene expression on CA1, CA2, CA3 part of rat hippocampus reduced obviously, the comparison between experimental group and the model control group showed significant difference (P < 0.05). CONCLUSION: CGZMD decreased NMDAR1 mRNA gene expression, it may be caused the NMDA receptor decline, hence revealed its anti-epileptic effect.

Animals↗