Biomedical subjects

C Jiang

Publications and source records attributed to C Jiang.

At least 91 records · Page 5Linked to original sources

PubMed2000

Cloning and characterization of CIS 1b (cytokine inducible SH2-containing protein 1b), an alternative splicing form of CIS 1 gene.

JAK-STAT pathway is essential in relaying cytokine signals and plays a vital role in cellular responses such as proliferation, differentiation and immunity. Some members of a recently found cytokine-inducible SH2 protein (CIS, =SOCS or SSI) family have proved to have negative effects on modulating JAK-STAT signaling pathway. In the present study, a novel human cDNA (CIS1b) which proved to be a variant of CIS1 gene was isolated by screen human placenta lambda gt11 cDNA library and 5'-rapid amplification of cDNA ends (RACE). Furthermore, the gene structure of CIS1 was determined by comparing the cDNA sequences of CIS1 and CIS1b to the genomic sequence in human chromosome 3p21.3. The expression patterns of CIS1b as well as CIS1 were analysed by Northern blot.

Alternative Splicing↗

PubMed2000

Computerization of leprosy records: national leprosy recording and reporting system in China.

This paper describes the national system of leprosy recording and reporting in China and the computerization of records. The system was designed for data collection at local level and data entry by optically scanned or manual mode as well as for sophisticated data analysis. The major functions include data entry, data check, sum-up, maintenance, communication, inquiry, statistics, graph and print. A total of 17 options for epidemiological and clinical data analysis are available. Through the implementation for about 10 years, the system has gained widespread acceptance. This acceptance would facilitate introduction of computer analysis to other leprosy projects and other disease control programs in China. Up to 1998, a database of more than 740,000 records covering all the leprosy patients detected since 1949 had been established by this system.

Adolescent↗

PubMed2000

[Association between hypertensive cerebrovascular stroke and renin-angiotensin system gene polymorphism from Chinese cohort in Shanghai].

OBJECTIVE: To evaluate the association between hypertensive cerebrovascular stroke and renin-angiotensin system gene polymorphism from Chinese cohort. METHODS: The polymorphisms of angiotensinogen(AGT) and angiotensin-converting enzyme(ACE) from 257 cases of simple essential hypertension(EH) and 218 cases of hypertensive stroke(131 hemorrhagic cases and 87 ischemic cases were detected by PCR-RFLP. RESULTS: The frequencies of DD genotype and D allele of ACE gene in ischemic stroke were significantly higher than those in hemorrhagic stroke and EH, and the odds ratios(OR) of DD/II genotype were 3.25(2.20-4.79) and 2.87(2.03-4.06), while the OR of D/I allele were 1.83(1.38-2.43) and 1.69(1.27-2.24) respectively. Otherwise, there was no difference in frequency distribution of Met235Thr mutation polymorphism and DD+TT/non DD non TT combined among the three groups. CONCLUSION: The I/D polymorphism of ACE gene may be one of the risk factors and susceptible genetic markers for ischemic stroke with essential hypertension in Chinese.

Angiotensinogen↗

PubMed2000

Effect of nifedipine on proliferation and DNA synthesis of human gingival fibroblasts.

OBJECTIVE: To investigate the effect of Nifedipine, a calcium channel blocker, on cellular proliferation in gingival fibroblasts in vitro. METHODS: Gingival fibroblasts were cultured and incubated with various concentrations of Nifedipine (23.5, 108, 360, and 1200 ng/mL) for up to 7 days. RESULTS: Cell numbers were significantly different among these groups on the sixth and seventh days, especially between the 1200 ng/mL or 360 ng/mL and the other concentrations. CONCLUSION: Nifedipine can influence proliferation of gingival fibroblasts in high concentrations.

Adolescent↗

PubMed2000

[Utilization of municipal sludge in agriculture and sustainable development].

Based on the ideas of sustainable development, this paper analyzed the features and disposal situations of municipal sludge and its influence on agricultural and urban development. It is suggested that the land application of municipal sludge is significant and urgent for urban and agricultural sustainable development. Land application of sludge will also be basic outlet for sludge disposal in the future. The key of land application of sludge lies in controlling the content of toxic pollutants in sludge and utilizing sludge scientifically.

Agriculture↗

PubMed2000

Neuroendocrine differentiation in ovarian mucinous tumors.

OBJECTIVE: To investigate the relationship between neuroendocrine differentiation in ovarian mucinous tumors and its genesis. METHODS: A morphologic study of seventy-three cases of ovarian mucinous tumors (32 benign, 20 borderline, 21 malignant) using immunohistochemical and immunohistochemical/histochemical double staining techniques. RESULTS: The study showed that in tumors of benign, borderline and malignant types, the incidence of chromogranin A (CgA) positive cells was 62.5%, 75%, 76% and that of 5-hydroxytryptamine (5-HT) positive cells was 31.3%, 40% and 39%, respectively. Neuroendocrine cells (NEC) were not evenly distributed in any tumor. In four cases of the benign tumors, the number of CgA positive cells was more than 30 percent, localizing between the glandular basement membrane and the mucinous epithelial cells, with many intermediate cells containing both CgA and periodic acid-schiff (PAS) positive granules. CONCLUSION: The occurrence of both neuroendocrine and exocrine granules within the same cell has been previously described as "intermediate" in pancreatic hyperplasia, pancreatic tumors and lung signet-ring cell carcinoids. This has not previously been observed in benign ovarian mucinous tumors. Finding both endocrine and exocrine granules within a single cell seems to indicate a histogenetic relationship between the ovarian endocrine and exocrine cells. The four cases of the benign tumors might be originated from a common stem cell, such as the so-called amphocrine cell. The relationship between these four tumors and neuroendocrine differentiation in ovarian mucinous tumors needs to be further clarified.

Adenocarcinoma, Mucinous↗

PubMed2000

[Study on the relation between hypertensive left ventricular hypertrophy in very old people with neurohormonal factors and ventricular arrhythmias].

OBJECTIVE: To study the relation between hypertensive left ventricular hypertrophy (LVH) in very old people (> 80 year) with neuro-hormone factors and ventricular arrhythmias. METHODS: Measurements were made on the heart rate variation, renin (Ren), angiotensin-II (AT-II), aldosterone (Ald), insulin (Ins), Holter and ambulatory blood pressure monitor in 60 cases of 2 groups: 30 with primary hypertension in very old people and LVH (group A); 30 with simple primary hypertension in very old people (group B). RESULTS: (1) There was no significant difference of AT-II and Ren among group A and B (P > 0.05); (2) Ins and Ald value in group A was much higher than group B (P all < 0.01); (3) Very lower frequency (VLF) and low frequency (LF) and LF/HF (high frequency) in group A were significantly higher than group B (P < 0.01, 0.05, 0.05, respectively); (4) incidence of premature ventricular beats and myocardial ischemia in group A were higher than those in group B. CONCLUSIONS: (1) Sympathetic nerve excitability in group A was greatly increased; (2) Hypertensive LVH were closely associated with Ald and Ins level, but not with AT-II and Ren; (3) There was obvious correction between group A and premature ventricular beats and ischemia.

Aged↗

PubMed2000

[Diagnosis and surgical treatment of temporal lobe epilepsy].

OBJECTIVE: To discuss the diagnosis and surgical treatment of temporal lobe epilepsy. METHODS: From 1995 to 1998, 30 patients with intractable mesial temporal lobe epilepsy were identified by EEG and MR. Among them, 15 patients underwent anterior temporal lobectomy, while another 15 patients accepted selective amygdalahippocampectomy. The results of operation and follow-up were analyzed. RESULTS: As to seizure outcome, all patients were benefited from surgery. Surgical result was satisfactory in 18 patients, notable in 11, and good in 1. There was no complication. CONCLUSIONS: MR is beneficial for the localization of epileptic foci. Operation is an effective way for the treatment of temporal lobe epilepsy. Selective amygdalohippocampus is the first choice for medial temporal lobe epilepsy. Transzygmatic-temporal lobe base approach improves the safety of operation.

Adolescent↗

PubMed2000

[Clinical observation on operation of cerebral speech area under combined acupuncture-drug anesthesia].

OBJECTIVE: To study the effect of combined acupuncture-drug anesthesia (CADA) in neurosurgical operation of cerebral speech area. METHODS: Twenty-five patients with tumor close to the speech area underwent neurosurgical operation under CADA or general anesthesia were observed, and the post-operational language function protecting effect was analyzed. RESULTS: Among the 15 patients accepted CADA, total tumor resection was achieved in 9 cases, and subtotal or partial resection achieved in 6 due to their tumor too close to the speech area. No post-operational complication such as dysphasia or aggravation of functional disorder was found in the patients. In the 10 cases underwent general anesthesia, 7 had tumor total resection, 3 had partial resection, and 3 cases suffered from post-operational dysphasia. CONCLUSION: CADA is helpful in speech area judgement in neurosurgical operation so as to avoid the operational injury on functional area. It is an important method of anesthesia in surgical operation on cerebral speech area.

Acupuncture Analgesia↗

PubMed2000

[Parent artery occlusion for the treatment of vertebral artery aneurysm].

OBJECTIVE: To describe the endovascular treatment of posterior aneurysm with balloon occlusion of ipsilateral vertebral artery. METHODS: 10 patients aging from 12 to 52 years old with mean age 41 were performed occlusion of unilateral vertebral artery after 30 minutes test occlusion. The whole procedure was under systemic anticoagulation. The Willi's Circle was evaluated by MRA before treatment. RESULTS: No immediate complication occurred after the treatment. 10 patients were followed up for 3 months to 5 years. 8 of the 10 cases accepted MR or DSA examination. Focal infarction was found in one patient. The aneurysm was filling in contralateral vertebral artery angiography in one patient, but there was no symptom. CONCLUSION: Vertebral artery occlusion is an effective treatment to some complicated posterior circulation aneurysms, which is difficult to be clipped and coiled.

Adolescent↗

PubMed1999

Striking bimodal methylation of the repeat unit of the tandem array encoding human U2 snRNA (the RNU2 locus).

The genes encoding human U2 small nuclear RNA are arrayed in tandem (the RNU2 locus) and have undergone concerted evolution for >35 Myr. Tandem organization of repetitive sequences may facilitate recombination that underlies concerted evolution, but could risk instability. Since DNA methylation plays a crucial role in genome stability, we investigated the methylation status of the RNU2 locus to understand the forces maintaining array stability and homogeneity. We found that a region of approximately 1.5 kb spanning the U2 promoter, U2 gene sequence, and CT microsatellite is completely unmethylated, whereas the rest of the repeat is heavily methylated. Since the U2 transcription enhancer DSE and CT microsatellite mark the boundaries between methylated and unmethylated domains, they might function as cis-acting elements for establishing and maintaining proper methylation at the RNU2 locus. Interestingly, the RNU2 locus in human fibrosarcoma line HT1080 is hypomethylated, and de novo methylation did not occur in an artificial U2 tandem array introduced by stable transfection. The observed bimodal methylation pattern may be important for both efficient transcription of U2 gene and maintenance of nearly perfect tandem arrays in somatic cells.

Cell Line↗

PubMed1999

Opposite effects of pH on open-state probability and single channel conductance of kir4.1 channels.

1. A decrease in intracellular pH (pHi) inhibits whole-cell Kir4.1 currents. To understand channel biophysical properties underlying this inhibition, single channel Kir4.1 currents were studied in inside-out patches using symmetric concentrations of K+ applied to each side of the plasma membrane. Under such conditions, inward rectifying currents were observed in about 2 of 3 patches. At pH 7.4, these currents showed a single channel conductance of 22 pS with a channel open-state probability (Popen) of approximately 0.9. 2. The effects of intracellular protons on macroscopic Kir4.1 currents were examined in giant inside-out patches at various pH levels of internal solutions. Current amplitude increased with a modest acidification (pH 7.0 and 6.6), and decreased with further reductions in pHi. The Kir4.1 currents were completely suppressed at pH 5.4. These effects were fast and reversible. 3. Low pHi inhibited Popen and enhanced single channel conductance in a concentration-dependent manner with pK (midpoint pH value for channel inhibition) of 6.0 and 6.8, respectively. At pH 5.8, Popen was inhibited by 70 % and single channel conductance increased by 35 %. Washout brought both Popen and single channel conductance rapidly back to baseline levels. 4. Theoretical currents were calculated using percentage changes in Popen and single channel conductance at each pH level tested. The trajectory of these currents is very close to that of experimental currents recorded from giant patches. Thus, opposite effects of intracellular protons on Popen and single channel conductance are demonstrated, which are likely to result in changes of macroscopic Kir4.1 currents with low pH.

Animals↗

PubMed1999

Functional and structural diversity of the human Dickkopf gene family.

Wnt proteins influence many aspects of embryonic development, and their activity is regulated by several secreted antagonists, including the Xenopus Dickkopf-1 (xDkk-1) protein. xDkk-1 inhibits Wnt activities in Xenopus embryos and may play a role in induction of head structures. Here, we characterize a family of human Dkk-related genes composed of Dkk-1, Dkk-2, Dkk-3, and Dkk-4, together with a unique Dkk-3 related protein termed Soggy (Sgy). hDkks 1-4 contain two distinct cysteine-rich domains in which the positions of 10 cysteine residues are highly conserved between family members. Sgy is a novel secreted protein related to Dkk-3 but which lacks the cysteine-rich domains. Members of the Dkk-related family display unique patterns of mRNA expression in human and mouse tissues, and are secreted when expressed in 293T cells. Furthermore, secreted hDkk-2 and hDkk-4 undergo proteolytic processing which results in cleavage of the second cysteine-rich domain from the full-length protein. Members of the human Dkk-related family differ not only in their structures and expression patterns, but also in their abilities to inhibit Wnt signaling. hDkk-1 and hDkk-4, but not hDkk-2, hDkk-3 or Sgy, suppress Wnt-induced secondary axis induction in Xenopus embryos. hDkk-1 and hDkk-4 do not block axis induction triggered either by Xenopus Dishevelled (Xdsh) or Xenopus Frizzled-8 (Xfz8), both of which function to transduce signals from Wnt ligands. Thus, hDkks 1 and 4 may inhibit Wnt activity by a mechanism upstream of Frizzled. Our findings highlight the structural and functional heterogeneity of human Dkk-related proteins.

Amino Acid Sequence↗

PubMed1999

Identification of a critical motif responsible for gating of Kir2.3 channel by intracellular protons.

Protons are involved in gating Kir2.3. To identify the molecular motif in the Kir2.3 channel protein that is responsible for this process, experiments were performed using wild-type and mutated Kir2. 3 and Kir2.1. CO2 and low pHi strongly inhibited wild-type Kir2.3 but not Kir2.1 in whole cell voltage clamp and excised inside-out patches. This CO2/pH sensitivity was completely eliminated in a mutant Kir2.3 in which the N terminus was substituted with that in Kir2.1, whereas a similar replacement of its C terminus had no effect. Site-specific mutations of all titratable residues in the N terminus, however, did not change the CO2/pH sensitivity. Using several chimeras generated systematically in the N terminus, a 10-residue motif near the M1 region was identified in which only three amino acids are different between Kir2.3 and Kir2.1. Mutations of these residues, especially Thr53, dramatically reduced the pH sensitivity of Kir2.3. Introducing these residues or even a single threonine to the corresponding positions of Kir2.1 made the mutant channel pH-sensitive. Thus, a critical motif responsible for gating Kir2.3 by protons was identified in the N terminus, which contained about 10 residues centered by Thr53.

Amino Acid Sequence↗

PubMed1999

Effects of intra- and extracellular acidifications on single channel Kir2.3 currents.

1. The inward rectifier K+ channel Kir2.3 is inhibited by hypercapnia, and this inhibition may be mediated by decreases in intra- and extracellular pH. To understand whether Kir2.3 has two distinct pH sensors and whether cytosol-soluble factors are involved in the modulation of this channel during intracellular acidification, single channel currents were studied by expressing Kir2.3 in Xenopus oocytes. 2. In excised inside-out patches, Kir2.3 currents had a high baseline channel open-state probability (Po, at pH 7.4) with a strong inward rectification. Single channel conductance at hyperpolarizing membrane potential was about 17 pS with 150 mM K+ applied to both sides of the membrane. The channel showed a substate conductance of about 8 pS. 3. Reduction of intracellular pH (pHi) produced a fast and reversible inhibition of single channel Kir2.3 currents in inside-out patches. The extent of this inhibition is concentration dependent. A clear reduction in Kir2.3 currents was seen at pHi 7.0, and channel activity was completely suppressed at pHi 6.2 with mid-point inhibition (pK) at pH 6.77. 4. The effect of low pHi on Kir2.3 currents was due to a strong inhibition of Po and a moderate suppression of single channel conductance. The pK values for these single channel properties were pH 6.78 and 6.67, respectively. 5. The decrease in Po with low pHi resulted from an increase in the channel mean closed time without significant changes in the mean open time. Substate conductance was not seen during low pHi. 6. Decrease in extracellular pH (pHo) also caused inhibition of single channel activity of Kir2.3 currents in excised outside-out patches. This effect, however, was clearly different from that of pHi: the pK (pH 6.70) was about 0.1 pH units lower; more than 50 % channel activity was retained at pHo 5.8; and low pHo affected mainly single channel conductance. 7. These results therefore indicate that (1) there are two distinct pH sensors in Kir2.3, (2) different mechanisms are involved in the modulation of Kir2.3 through these two pH sensors, and (3) cytosol-soluble factors do not appear to be engaged in this modulation.

Algorithms↗

PubMed1999

Suppression of Kir2.3 activity by protein kinase C phosphorylation of the channel protein at threonine 53.

Kir2.3 plays an important part in the maintenance of membrane potential in neurons and myocardium. Identification of intracellular signaling molecules controlling this channel thus may lead to an understanding of the regulation of membrane excitability. To determine whether Kir2.3 is modulated by direct phosphorylation of its channel protein and identify the phosphorylation site of protein kinase C (PKC), we performed experiments using several recombinant and mutant Kir2.3 channels. Whole-cell Kir2.3 currents were inhibited by phorbol 12-myristate 13-acetate (PMA) in Xenopus oocytes. When the N-terminal region of Kir2.3 was replaced with that of Kir2.1, another member in the Kir2 family that is insensitive to PMA, the chimerical channel lost its PMA sensitivity. However, substitution of the C terminus was ineffective. Four potential PKC phosphorylation sites in the N terminus were studied by comparing mutations of serine or threonine with their counterpart residues in Kir2.1. Whereas substitutions of serine residues at positions 5, 36, and 39 had no effect on the channel sensitivity to PMA, mutation of threonine 53 completely eliminated the channel response to PMA. Interestingly, creation of this threonine residue at the corresponding position (I79T) in Kir2.1 lent the mutant channel a PMA sensitivity almost identical to the wild-type Kir2.3. These results therefore indicate that Kir2.3 is directly modulated by PKC phosphorylation of its channel protein and threonine 53 is the PKC phosphorylation site in Kir2.3.

Animals↗

PubMed1999

Binding and uptake of cationic lipid:pDNA complexes by polarized airway epithelial cells.

To better understand the barriers associated with cationic lipid-mediated gene transfer to polarized epithelial cells, Fischer rat thyroid (FRT) cells and polarized normal human bronchial epithelial (NHBE) cells grown on filter supports at an air-liquid interface were used to study the binding and uptake of cationic lipid:plasmid DNA (pDNA) complexes. The efficiencies of binding and uptake of cationic lipid:pDNA complexes by these cell systems were monitored using fluorescence microscopy of fluorescently tagged lipid or pDNA probes. Fluorescent probe bound to the cell surface was differentiated from internalized probe by adding trypan blue, which quenched the fluorescence of bound but not internalized probes. For proliferating cells, binding and internalization of the cationic lipid:pDNA complexes were determined to be efficient. In contrast, little binding or internalization of the complexes was observed using polarized epithelial cells. However, after aspirating a small area of cells from the filter support, virtually all of the cells adjoining this newly formed edge bound and internalized the cationic lipid:pDNA complexes. To determine if their uptake in edge cells was related to the ability of the complexes to access the basolateral membranes of these cells, the binding and uptake of complexes was monitored in polarized NHBE cells that had been pretreated with EGTA or Ca2+-free media, strategies known to disrupt tight junctions. Cells treated in this manner bound and internalized cationic lipid:pDNA complexes efficiently and also expressed significant levels of transgene product. Control cells with intact tight junctions neither bound complexes nor expressed significant transgene product. These data confirm and extend earlier observations that the polarized apical membranes of airway epithelial cells are resistant to transfection by lipid:pDNA complexes. Further, in contrast to previous studies that have shown the entry step of complexes is not an important barrier for COS and HeLa cells, binding and entry of complexes in polarized NHBE cells appear to be rate limiting. These findings suggest that strategies designed to open the tight junctions of polarized epithelial cells may improve gene delivery to these cells for diseases such as cystic fibrosis (CF).

Alkaline Phosphatase↗

PubMed1999

Selenium-induced inhibition of angiogenesis in mammary cancer at chemopreventive levels of intake.

The trace element nutrient selenium (Se) has been shown to possess cancer-preventive activity in both animal models and humans, but the mechanisms by which this occurs remain to be elucidated. Because angiogenesis is obligatory for the genesis and growth of solid cancers, we investigated, in the study presented here, the hypothesis that Se may exert its cancer-preventive activity, at least in part, by inhibiting cancer-associated angiogenesis. The effects of chemopreventive levels of Se on the intra-tumoral microvessel density and the expression of vascular endothelial growth factor in 1-methyl-1-nitrosourea-induced rat mammary carcinomas and on the proliferation and survival and matrix metalloproteinase activity of human umbilical vein endothelial cells in vitro were examined. Increased Se intake as Se-enriched garlic, sodium selenite, or Se-methylselenocysteine led to a significant reduction of intra-tumoral microvessel density in mammary carcinomas, irrespective of the manner by which Se was provided: continuous exposure (7-wk feeding) with a chemoprevention protocol or acute bolus exposure (3 d) after carcinomas had established. Compared with the untreated controls, significantly lower levels of vascular endothelial growth factor expression were observed in a sizeable proportion of the Se-treated carcinomas. In contrast to the mammary carcinomas, the microvessel density of the uninvolved mammary glands was not altered by Se treatment. In cell culture, direct exposure of human umbilical vein endothelial cells to Se induced cell death predominantly through apoptosis, decreased the gelatinolytic activities of matrix metalloproteinase-2, or both. These results indicate a potential for Se metabolites to inhibit key attributes (proliferation, survival, and matrix degradation) of endothelial cells critical for angiogenic sprouting. Therefore, inhibition of angiogenesis associated with cancer may be a novel mechanism for the anticancer activity of Se in vivo, and multiple mechanisms are probably involved in mediating the anti-angiogenic activity.

Animals↗