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Biomedical subjects

J Yao

Publications and source records attributed to J Yao.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Effects of seed coating formulation on seedling characters of Atractylodes macrocephala].

The effects of seed coating formulation (SCF) of Atractylodes macrocephala Koidz. on seedling in two experimental plots located in Hangzhou and Jiande were studied, and desinged with L9(3(4)) orthogonal comparison. The results showed that the SCF with paclobutrazol (pp333) had a significant effect on the rate of germination at Hangzhou plot, all factors had no significant effects on length of seedlings in both plots, and both atonik (sodium O-nitrophenolate) and PP333 on the fresh or dry seedling weight had significant effects.

Asteraceae↗
PubMed2001

[The VIP-immunoreactive nerve fibers in dental pulp-dentin complex of human premolar].

OBJECTIVE: The expression of vasoactive intestinal peptide (VIP) in dental pulp-dentin complex of human premolar was studied to find out the relationship of distribution and function of VIP positive nerve fibers. METHODS: Fresh health premolars were collected, fixed, decalcified, embedded in paraffin and cut into slices. The slices were treated by immunohistochemical reaction of VIP and quantitative image analysis was then carried out. RESULTS: VIP positive nerve fibers in dental root were in bundle and branches of the nerve fibers were few. The nerve fibers extended in a radiative way from cervical line to the coronal pulp and branched a lot. A part of branches surrounded blood vessels, some terminated in the dental pulp matrix, the others passed odontoblast layer and ran into the predentin. In the coronal pulp the integral optical density was 12.7400 +/- 1.8070, the volume density was 0.0192 +/- 0.0127, the length density was 0.0046 +/- 0.0028; in predentin the integral optical density was 13.0700 +/- 1.9270, the line length was (19.6000 +/- 8.5970) microns. CONCLUSIONS: VIP-immunoreactive nerve fibers exist in human dental pulp-dentin complex. Some fibers surround blood vessels, some terminate in dental pulp matrix and predentin, which suggest that in addition to relating the action of blood vessels, VIP-immunoreactive nerve fibers might also relate to sense.

Adolescent↗
PubMed2001

Relationship between hyperventilation and intracranial pressure in patients with severe head injury.

With high fatality rate and disability rate, the pathophysiologic changes of severe head injury are complicated. But the method of lowering intracranial pressure (ICP) through artificial hyperventilation is called in question recently. To understand the related changes of the partial pressure of carbon dioxide in artery (PaCO(2)) and the ICP at the acute period of severe head injury, a total of 64 patients with severe head injury were monitored and analyzed on the 3rd day after injury.

Adolescent↗
PubMed2001

Generation of EST and cDNA microarray resources for the study of bovine immunobiology.

Recent developments in expressed sequence tag (EST) and cDNA microarray technology have had a dramatic impact on the ability of scientists to study the responses of thousands of genes to external stimuli, such as infection, nutrient flux, and stress. To date however, these studies have largely been limited to human and rodent systems. Despite the tremendous potential benefit of EST and cDNA microarray technology to studies of complex problems in domestic animal species, a lack of integrated resources has precluded application of these technologies to domestic species. To address this problem, the Center for Animal Functional Genomics (CAFG) at Michigan State University has developed a normalized bovine total leukocyte (BOTL) cDNA library, generated EST clones from this library, and printed cDNA microarrays suitable for studying bovine immunobiology. Our data revealed that the normalization procedure successfully reduced highly abundant cDNA species while enhancing the relative percentage of clones representing rare transcripts. To date, a total of 932 EST sequences have been generated from this library (BOTL) and the sequence information plus BLAST results made available through a web-accessible database (http://gowhite.ans.msu.edu). Cluster analysis of the data indicates that a total of 842 unique cDNAs are present in this collection, reflecting a low redundancy rate of 9.7%. For creation of first generation cDNA microarrays, inserts from 720 unique clones in this library were amplified and microarrays were produced by spotting each insert or amplicon 3 times on glass slides in a 48-patch arrangement with 64 total spots (including blanks and positive controls) per patch. To test our BOTL microarray, we compared gene expression patterns of concanavalin A stimulated and unstimulated peripheral blood mononuclear cells (PBMCs). In total, hybridization signals on over 90 amplicons showed upregulation (> 3x) in response to Con A stimulation, relative to unstimulated cells. A second experiment with PBMCs from a different group of animals was performed to test reproducibility of microarray results. There was a high correlation between the 2 experiments (r = 0.72, P < 0.001). Resources described in this publication offer a highly efficient and integrated system to study gene expression changes in bovine leukocytes.

Animals↗
PubMed2001

An immunogenomics approach to understanding periparturient immunosuppression and mastitis susceptibility in dairy cows.

Studies comparing in vivo and in vitro functional capacities of leukocytes from non-parturient and periparturient dairy cows have provided substantial evidence that systemic and local mammary immune defenses are deficient around parturition. This evidence has lead to the reasonable hypothesis that immune deficiency underlies the heightened mastitis susceptibility of periparturient cows. Nutrition and vaccine studies substantiate this hypothesis, showing that dietary antioxidant supplementation and rigorous immunization regimes can bolster innate and humoral immunity to the point that mastitis severity and time for return to normal milk production are reduced. However, completely effective resolution of this significant production disease has not been achieved because so little is understood about its complex etiology. In particular, we possess almost no knowledge of how or why immune cells responding to parturient physiology end up with deficient functional capacities. Fluctuations in reproductive steroid hormones and chronic shifts in neuroendocrine hormones with roles in nutrient partitioning and appetite control may affect the expression of critical leukocyte genes in periparturient dairy cows. A thorough understanding of leukocyte biology during periparturition would seem a critical goal for future development of effective mastitis prevention strategies. Recently, our group has begun to use cDNA microarray technology to explore bovine leukocyte RNA for global gene expression changes occurring around parturition. We are working within the context of a hypothesis that the physiology of parturition negatively affects expression of critical genes in blood leukocytes. In the current study we initiated hypothesis testing using leukocyte RNA from a high producing Holstein cow collected at 14 days prepartum and 6 hours postpartum to interrogate a cDNA microarray spotted with > 700 cDNAs representing unique bovine leukocyte genes. This analysis revealed 18 genes with > or = 1.2-fold higher expression 14 days prepartum than 6 hours postpartum. BLASTN analysis of these genes revealed only one that can be considered a classical immune response gene. All other repressed genes were either unknown or putatively identified as encoding key proteins involved in normal growth and metabolism of cells. Given the critical roles of these repressed genes in normal cell functions, we may have identified good candidates to pursue with respect to periparturient immunosuppression and mastitis susceptibility.

Animals↗
PubMed2001

[Immediate microcirculation reaction of periodontal ligaments to experimental intrusion of dog teeth].

OBJECTIVE: The purpose of this study is to investigate the immediate microcirculation reaction of periodontal ligaments to experimental intrusion of dog teeth. METHODS: The forth premolar was chosen as the anchor tooth to intrude the second premolar using an intrusion circle loop. All tissue sections were observed and analyzed using the ink perfusion technique and an image analysis apparatus. RESULTS: The microvascular pattern of periodontal ligaments was changed after the maxillary second premolar had been intruded for 2 hours with 100 g of force. The vascular diameter and volume density diminished, but the vascular number and some parts of the microvasculature, especially capillaries were compressed due to the blood escaping from the periodontal ligament. It showed that the initial effect of 100 g of intrusive force caused adaptable changes in the microcirculation of periodontal ligaments, but no significant impediment of blood flow occurred. CONCLUSION: During the tooth intrusion with 100 g of force, a suitable microenvironment was established for the benefit of the survival of periodontal ligaments, which could avoid overloads imposed on the periodontal ligament and decreased the injury of periodontal tissue. It elucidates that the microcirculation of periodontal ligaments plays an important role in the protection of the periodontal tissue, in terms of biological function.

Animals↗
PubMed2001

[Study on apoE gene polymorphism in Chinese type II b hyperlipidemia].

OBJECTIVE: To study apolipoprotein(apo) E polymorphism and its relationship with plasma lipids and apolipoproteins levels in Chinese patients with type II b hyperlip oproteinemia. METHODS: apoE genotypes were assayed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method, serum lipids were determined by enzyme method, and apolipoproteins were measured by radial immunodiffusion assay in 74 type II b hyperlipidemia patients whose fasting serum lipids levels were TG > or = 2.26 mmol/L, TC > or = 6.21 mmol/L and in 230 healthy subjects whose fasting serum lipids levels were TG < 1.82 mmol/L, TC < 6.21 mmol/L from a population of Chinese Han nationality in Chengdu area. RESULTS: Compared with the control group, the serum TG, TC, LDLC, nHDLC, apoA II, apoB100, apoC II, apoC III, apoE levels and TG/HDLC ratio in patients with type II b hyperlipidemia were significantly increased(P < 0.001), and the serum HDLC levels and apoE/apoC III ratio were significantly decreased (P < 0.05). ApoE3/3 genotype and allele epsilon 3 frequency in type II b hyperlipidemia group and control group were both the highest. In type II b hyperlipidemia group, allele epsilon 2 frequency tended to increase and allele epsilon 4 frequency tended to decrease as compared with those in the control group (P > 0.05). In type II b hyperlipidemia group the genotype of apoE2 was associated with higher serum TG, apoC II, apoE levels and apoE/apoC III ratio when compared with the genotype of apoE3; the genotype of apoE4 was associated with higher serum TC, nHDLC and apoE levels when compared with the genotypes E3 and E2 (P < 0.001). CONCLUSION: The alleles epsilon 2 and epsilon 4 are associated with serum TG, TC, nHDLC, apoC II and apoE levels to some extent in type II b hyperlipide in Chinese population.

Adult↗
PubMed2001

[The abnormal changes of apolipoprotein(s) in patients with type 2 diabetes mellitus].

OBJECTIVE: To investigate the changes of the apolipoproteins(apoA I, A II, B100, C II, C III, E) in patients with type 2 diabetes mellitus. METHODS: The levels of fasting plasma glucose(FBG), insulin, TG, TC, apoA I, A II, B100, C II, C III, E were all measured in 127 non-diabetic subjects and 143 type 2 diabetic patients (20 associated with coronary heart disease (CHD) and 66 associated with hypertriglyceridemia(HTG), 55 associated with hypercholesterolemia). RESULTS: In male type 2 diabetic patients, the levels of FBG, WHR and apoC II were significantly higher (P < 0.05) and apoA I, A II levels were significantly lower (P < 0.05) than those in male non-diabetic subjects. In female type 2 diabetic patients, the levels of FBG, BMI, WHR, TG significantly elevated while HDL-C, apoA I, A II levels significantly decreased as compared with those in female non-diabetic subjects. In type 2 diabetic group, the levels of WHR, FBG and TG in HTG patients were elevated significantly as compared with those without HTG, and the levels of HDL-C, apoA I and apoA II were decreased; the levels of WHR, TG, TC, apoB100, C II, C III, E in patients with HTC were significantly higher than those whose cholesterol levels were normal. In patients with CHD, the levels of fasting insulin, apoB100, apoC II and apoE were significantly higher than those in patients without CHD, and the levels of HDL-C and apoA II were decreased significantly. CONCLUSION: Abnormal changes of apo(s) in type 2 diabetes mellitus may be a cause of type 2 diabetes associated with HTG and CHD.

Adult↗
PubMed2001

[New progress of surface enhanced Raman spectroscopic studies on a gold electrode in a nonaqueous system].

Based on a highly sensitive new generation confocal microprobe Raman system, the adsorption behavior of thiocyanate (SCN-) on a gold electrode in methanol solution was investigated by SERS for the first time. Preliminary results demonstrated that the interaction between SCN- and the electrode is so strong that its SERS signal can be detected in the whole research potential region (-0.1 V(-)-1.4 V). The orientation change may occur in the potential range -0.6 V-0.7 V. From -0.1 V to -0.6 V SCN- is adsorbed mainly through S end onto Au surface while in the potential range of -0.7 V to -1.2 V it is oriented mainly through N end. The potential dependence of the Raman frequency of nu CN resulted in two different values of electrochemical Stark effect, suggesting the existence of molecular orientation change.

Electrochemistry↗
PubMed2001

[Determination of impurities in electrolytic manganese by atomic absorption spectrometry].

The content of K, Na, Ca, Mg, Fe in electrolytic manganese are determined by FAAS, and content of Cu, Cr, Co, Ni determined by GFAAS after sample is dissolved by HCl (aq). The best condition for determination is investigated, including method of dissolving and acidity, and influence of coexist elements and exclusion of these influences. The methods prove to be rapid, accurate and convenient. The recoveries of method are 88.9%-108.7%, the relative standard deviations are 0.6%-6.7%. The results obtained by calibration curve method are in good conformity with the standard addition method and results measured by ICP. The method can be utilized in analysis of impurities in electrolytic manganese.

Chromium↗
PubMed2000

Direct interaction between endothelial nitric-oxide synthase and dynamin-2. Implications for nitric-oxide synthase function.

Endothelial nitric-oxide synthase (eNOS) is regulated in part through specific protein interactions. Dynamin-2 is a large GTPase residing within similar membrane compartments as eNOS. Here we show that dynamin-2 binds directly with eNOS thereby augmenting eNOS activity. Double label confocal immunofluorescence demonstrates colocalization of eNOS and dynamin in both Clone 9 cells cotransfected with green fluorescent protein-dynamin and eNOS, as well as in bovine aortic endothelial cells (BAEC) expressing both proteins endogenously, predominantly in a Golgi membrane distribution. Immunoprecipitation of eNOS from BAEC lysate coprecipitates dynamin and, conversely, immunoprecipitation of dynamin coprecipitates eNOS. Additionally, the calcium ionophore, a reagent that promotes nitric oxide release, enhances coprecipitation of dynamin with eNOS in BAEC, suggesting the interaction between the proteins can be regulated by intracellular signals. In vitro studies demonstrate that glutathione S-transferase (GST)-dynamin-2 quantitatively precipitates both purified recombinant eNOS protein as well as in vitro transcribed (35)S-labeled eNOS from solution indicating a direct interaction between the proteins in vitro. Scatchard analysis of binding studies demonstrates an equilibrium dissociation constant (K(d)) of 27.6 nm. Incubation of purified recombinant eNOS protein with GST-dynamin-2 significantly increases eNOS activity as does overexpression of dynamin-2 in ECV 304 cells stably transfected with eNOS-green fluorescent protein. These studies demonstrate a direct protein-protein interaction between eNOS and dynamin-2, thereby identifying a new NOS-associated protein and providing a novel function for dynamin. These events may have relevance for eNOS regulation and trafficking within vascular endothelium.

Animals↗
PubMed2000

Pressurized gradient capillary electrochromatographic separation of eighteen amino acid derivatives.

A pressurized gradient capillary electrochromatography (pCEC) instrument was developed to separate 18 amino acid derivatives. A reversed-phase C18 column (3 microm, 130 mm x 75 microm I.D.) and an acetate buffer (50 mmol/l NaAc, pH 6.4) with an ion-pair reagent (1% N,N-dimethylformamide) were used to separate derivatized amino acids from a standard solution (2 microg/ml), and the wavelength of the UV-Vis detector was 360 nm. The pressure on the capillary column was kept at approx. 70 Pa and 3 kV positive voltage was added on the outlet end of column. The effect of voltage on the eluting order of amino acids and the resolution of separation were studied, and it was found that when the voltage was higher than 3 kV, the adsorption of amino acids in the porous C18 column occurred. The effect of salt concentration, injection volume, and column length on the separation of amino acids was determined. The amino acid sample was separated by pCEC, and RSDs of the migration times of each amino acid were all less than 2.5%.

Amino Acids↗
PubMed2000

Characterization of human SCO1 and COX17 genes in mitochondrial cytochrome-c-oxidase deficiency.

At least three proteins, COX17p, SCO1p, and its homologue SCO2p are thought to be involved in mitochondrial copper transport to cytochrome-c-oxidase (COX), the terminal enzyme of the respiratory chain. Recently, we and others have shown that mutations in SCO2 are associated with a lethal infantile hypertrophic cardiomyopathy (HCMP) with COX-deficiency. The majority of patients with a similar phenotype were, however, negative for SCO2 mutations, suggesting the other genes as candidates for this disorder. Here we report on the genomic organization of SCO1 and COX17 on human chromosomes 17 and 3 respectively, and the complete sequence analysis of COX17 and SCO1 in 30 patients with COX deficiency. Using a panel of human:mouse-monochromosomal hybrids, the expression of COX17 was specifically restricted to chromosome 3, indicating that the previously reported sequence on chromosome 13 represents a pseudogene. DNA sequence analysis of SCO1 and COX17 in nine patients with severe COX deficiency and fatal HCMP, and in 21 patients with other COX deficiency disorders, did not reveal any pathogenic mutations or polymorphisms. We conclude that neither SCO1 nor COX17 are common causes of COX deficiency disorders.

Cardiomegaly↗
PubMed2000

The transcription factor EGR-1 directly transactivates the fibronectin gene and enhances attachment of human glioblastoma cell line U251.

EGR-1, a transcription factor with important functions in the regulation of growth and differentiation, is highly expressed in brain. Previous studies have shown that EGR-1 suppresses the transformed phenotype. However, the expression and role of EGR-1 in human glioblastoma cells are not yet determined. In this study, we found that the basal expression of the EGR-1 protein is undetectable, but is inducible in four human glioblastoma cell lines. To determine EGR-1 functions, we re-expressed EGR-1 in human glioblastoma U251 cells and found that the secretion of transforming growth factor-beta1 (TGF-beta1), plasminogen activator inhibitor-1 (PAI-1), and fibronectin (FN) was greatly enhanced. Addition of anti-TGF-beta antibodies completely inhibited the secretion of PAI-1, but had little effect on secretion of FN, indicating that PAI-1 is under the control of EGR-1-induced TGF-beta1. An examination of the promoter of the FN gene revealed two EGR-1-binding sites between positions -75 and -52 and positions -4 and +14 that specifically bound EGR-1 in gel mobility shift experiments. Utilizing wild-type and mutant FN promoter/luciferase reporter genes, we demonstrated that EGR-1 positively regulated the activity of the FN gene. In addition, cell adhesion and migration were greatly increased in the EGR-1-expressing cells, and adhesion was reversed by addition of RGD-containing peptides. These results suggest that EGR-1 may regulate cell interaction with the extracellular matrix by coordinated induction of TGF-beta1, FN, and PAI-1 in human glioblastoma cells.

Antibodies↗
PubMed2000

Sex-specific effects of in utero manipulation of GABA(A) receptors on pre- and postnatal expression of BDNF in rats.

Exposure to diazepam (DZ) during the last week of in utero development in rats induces neurobehavioral effects that do not become apparent in exposed animals until young adult ages. Some of the effects are sex specific. This study evaluated the hypothesis that late gestational exposure to DZ, a positive modulator of GABA(A) receptors, affects the developmental appearance of brain-derived neurotrophic factor (BDNF), an effect that could be linked to the later consequences of the exposure. Pregnant Long-Evans rats were injected with DZ (2.5 mg/kg) over gestation days 14-20, and their male and female offspring were evaluated for levels of BDNF mRNA and protein in the cerebral cortex and hypothalamus at fetal day 20 and at postnatal ages spanning birth to young adulthood. The effects of the exposure were sex and region specific. At fetal day 20 the expression of BDNF was reduced by about 20% in the hypothalamus of males only. The early exposure affected postnatal expression of BDNF in the hypothalamus only modestly, influencing the age-related profile in both sexes. Postnatal development of BDNF in the cerebral cortex was significantly affected by the in utero exposure in males only with mRNA levels lower in the exposed group and protein levels higher during juvenile ages. At adulthood, both levels were lower in DZ-exposed males. GABA serves a role as a trophic factor during early development, and these results suggest that manipulation of GABA(A) receptors during early development could interact with the developmental action of other trophic factors thereby leading to altered neural organization and later neurobehavioral dysfunction.

Animals↗
PubMed2000

Down-regulation of p27 is a significant predictor of poor overall survival and may facilitate metastasis in colorectal carcinomas.

The p27 gene product has been shown to have prognostic significance in a range of tumors. Down-regulation of p27 has also been implicated in loss of cell adhesion in tumor cells. Our study aimed to investigate whether p27 expression was significantly correlated with overall survival of colorectal carcinoma patients in the Singapore population, which is predominantly Chinese. Staining was performed on 136 paraffin-embedded specimens collected between 1991 and 1992 using an anti-p27 monoclonal antibody. Follow-up of patients was until time of death or for 5 years. There was a significant association between overall survival and p27 expression for all specimens. However, there was no significant correlation between p27 expression and other clinical features such as gender, age, tumor stage, differentiation, and site. When stratified by tumor stage, patients whose tumors exhibited higher metastatic potential (stage III/IV) but had strong p27 expression had a median survival that was 23 months longer than stage III/IV patients whose tumors had no or weak p27 expression. Our results thus suggest that one potential mechanism of action of p27 is to suppress metastasis possibly through its involvement in cell adhesion.

Age Factors↗