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Biomedical subjects

Hong Jiang

Publications and source records attributed to Hong Jiang.

At least 109 records · Page 6Linked to original sources
PubMed2005

[Forty-three tracheal stricture with Ni-Ti shape memory alloy stent].

OBJECTIVE: To evaluate the application of Ni-Ti shape memory alloy stent for treating tracheal stricture, including its indications and complications. METHODS: Forty-three patients clinical data were analyzed, among them, 15 suffered from tumor; 7 trauma; 4 granulation; 1 Wegener's granuloma, 2 rhinoscleroma, 1 without clear diagnosis; 7 were relapsing polychondritis; 1 were respiratory amyloidosis; 4 were tracheobronchial tuberculosis, 5 were tracheobronchomalacia. The stricture degree: Level I: 15 patients, Level II:24 patients, Level III:4 patients. The location of stricture in 5 patients extended to the subglottis area. All patients had tracheal stricture and accepted the treatment with Ni-Ti shape memory alloy stent. RESULTS: Forty-two patients breathed freely after the operation, 1 patient died after surgery. The tracheostoma in 18 patients was closed 34 days after operation. Among the remaining 8 patients with tracheostoma:3 patients left hospital with tracheal cannula; 1 patient died,2 patients were found stent shifted and no evident breath improving; 2 patients were found granulation and had secondary operation with laser. CONCLUSION: Ni-Ti shape memory alloy stent can expand the tracheal stricture quickly and thus improve the breath effectively, which is minimally invasive and simple. It can be used as a method in the treatment of tracheal stricture.

Adult↗
PubMed2005

[The clinical and genetic characteristics of autosomal recessive juvenile Parkinsonism in a Chinese family].

OBJECTIVE: To understand clinic and genetic characteristics of Chinese AR-JP. METHODS: The clinical dates of 1 Chinese AR-JP family was collected and analysed. Genomic DNA was extracted by standard techniques from venous blood leukocytes of members in three women of the family, polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) analysis and DNA sequencing were used to detect mutation of parkin gene. RESULTS: Onset age of 2 Chinese AR-JP patients is young, periods of disease is long, clinical manifestation include: resting tremor, rigidity, bradykinesias, disability, a good response to levodopa, but early levodopa induced symptom fluctuation; but no hyperactive tendon reflexes, sleep benefit, and foot dystonia. Parkin mutation analysis in 2 patients of the family discovered abnormal SSCP electrophoresis band, by DNA examination, conformed 2 base deletion mutation (exon 2 202-203delAG). CONCLUSIONS: Clinical features of Chinese AR-JP patients are different with Japanese AR-JP, similar with late-onset Parkinson disease; our study detected a parkin mutation (exon 2 202-203delAG), conform mutation of parkin gene is a cause of AR-JP in Chinese.

Adult↗
PubMed2005

The Qa-1 dependent CD8+ T cell mediated regulatory pathway.

The immune system has evolved a variety of regulatory mechanisms to ensure the peripheral self-tolerance as well as the optimal capacity to elicit effective anti-infection immunity. At present, there is no satisfactory conceptual framework to explain how the peripheral immunity is regulated at a biological system level, which enables the immune system to perform its essential functions to mount effective immunity to virtually any foreign antigens but avoid harmful immune responses to self. In this regard, during the past few years, an "affinity/avidity model of peripheral T cell regulation" has been proposed and tested, which opens up a new paradigm to understand how the peripheral immunity, to both self and foreign antigens, is regulated. The paradigm is based on the discovery of a subset CD8+ T cells with TCRs which specifically recognize a unique set of self-peptides presented by the MHC class Ib molecule Qa-1 differentially expressed on T cells as a function of the affinity/avidity of T cell activation. These Qa-1 restricted CD8+ T cells represent an example of how the immune system utilizes a unified mechanism to regulate adaptive immunity to both self and foreign antigens. Thus, by selectively down-regulating T cells of intermediate affinity/avidity, to any antigens, the immune system controls the adaptive immunity without the necessity to distinguish self from non-self in the periphery at the level of T cell regulation.

Animals↗
PubMed2005

[Mutation analysis of small heat shock protein 27 gene in Chinese patients with Charcot-Marie-Tooth disease].

OBJECTIVE: To investigate the features of small heat shock protein 27 (HSP27) gene mutation in Chinese patients with Charcot-Marie-Tooth disease (CMT). METHODS: DNA samples from 114 CMT probands were screened for mutations in HSP27 gene by polymerase chain reaction and direct sequencing, and haplotype analysis was further carried out on the mutation detected families. RESULTS: One missense mutation C379T was detected in 4 autosomal dominant CMT2 families. Haplotype analysis indicated that the 4 families probably had a common ancestor. CONCLUSION: To the authors' knowledge, this is the first report of HSP27 gene mutation in Chinese patients with CMT, but it may be not common(0.90%). The C379T mutation in HSP27 gene also causes CMT2 except for distal hereditary motor neuropathy, thus providing further evidence that even the same mutation in the same gene may lead to distinct phenotypes.

Asian People↗
PubMed2005

[The role of isoprenaline-induced, calcium-activated transient outward chloride current in atrial electrical remodeling of rabbit].

OBJECTIVE: To investigate the relationship between the changes of the L-type calcium current (I(Ca, L)) and the calcium-activated transient outward chloride current (I(Cl, Ca)), and the repolarization characteristic of action potential in phase 1 under isoprenaline (ISO) stimulation in atrium myocytes of rabbit. METHODS: Atrium myocytes were obtained by enzymatic dissociation from a section of atrial free wall. The membrane currents and action potential were recorded by the whole-cell patch-clamp technique. RESULTS: After recording I(Ca, L), atrium myocytes were perfused with ISO (1 micromol/L) immediately. Five minutes later, a transient outward current (I(to)) was significantly induced, and the peak of I(to) was gradually increased while I(Ca, L) gradually decreased with increasing in clamp voltage. The I(to) was resistant to 4-AP (3 mmol/L) but sensitive to DIDS (150 micromol/L, Cl(-) channel blocker). This current was blocked by CdCl(2) (200 micromol/L, Ca(2+) channel blocker). The elicited rate of I(to) was 91.67% (P < 0.05). (2) The shape of AP was like an inverse triangle with no plateau in Phase 2 after ISO (1 micromol/L) perfusion. Moreover, compared to the parameters of control group, APD(50) and APD(90) were significantly shortened from (65.4 +/- 4.2) ms and (95.8 +/- 3.8) ms to (12.8 +/- 3.8) ms and (27.0 +/- 4.7) ms, and reduced to 80.46% and 71.87%, respectively (P < 0.01, n = 12). 4-AP (3 mmol/L) had on obvious effect on the shape of AP, however, the plateau of AP in phase 2 was recovered by DIDS (150 micromol/L) perfusion, APD(50) and APD(90) were (41.1 +/- 4.5) ms and (79.6 +/- 3.4) ms respectively. Compared to the parameters of control group, there were no significant differences (P > 0.05, n = 12). These results indicated that ionic transport were changed by ISO perfusion in atrium myocytes and I(to) played an important role in the phase 1 repolarization of AP. CONCLUSIONS: Before ISO administration, we could only observe I(Ca, L) in atrium myocytes of rabbit. After isoproterenol intervention, certain intracellular ionic consistency and membrane ionic channels were changed. Calcium activated chloride channel and I(to2) revealed obvious predominance which shorten APD significantly. Action potential showed a triangle with no plateau, suggesting an electrical remodeling in atrium myocytes. The remodeling of ionic channel is related possibly with the opening of Ca(2+)-activated Cl(-) current, which maybe the electrophysiological base of reentrant atrial tachycardia.

Animals↗
PubMed2005

[Electrophysiological study of 16 patients with severe N-hexane neuropathy].

OBJECTIVE: To observe electrophysiological changes of severe N-hexane neuropathy getting active therapies and discuss its prognosis. METHODS: A follow-up study involved 16 adult severe N-hexane neuropathy patients who got active therapies was performed. EMG in right muscle of thenar, tibial muscle, and vastus medialis, NCV in right median nerve, common peroneal nerve, and sural nerve were determined and analyzed before treatment and in the first, the third, the ninth, and the twenty-fourth month after treatment. RESULTS: The electrophysiology in severe N-hexane neuropathy patients showed that the voluntary potential during muscle relaxation increased by 25.0%; the motor unit potential time limit prolonged by 20.8%, and the amplitude increased by 12.5%, and multiphasic wave increased by 16.5% during mild contraction; the raise decreased by 25.0% during strong contraction. In control group, the MCV, SCV, SNAP, DML, and CMAP of median nerve were (54.63 +/- 5.33) m/s, (59.25 +/- 6.45) m/s, (26.53 +/- 6.32) microV, (3.96 +/- 0.65)ms, and (9.89 +/- 2.30) mV respectively, the MCV, CMAP, DML of common peroneal nerve were (48.49 +/- 3.25) m/s, (5.47 +/- 1.77) mV, (5.20 +/- 1.27) ms respectively, and the SCV, SNAP of sural nerve were (63.21 +/- 9.30) m/s, (4.63 +/- 1.29) microV respectively. Severe N-hexane neuropathy patients presented significantly different abnormalities in the NCV and EMG (P < 0.01). The MCV, SCV, SNAP, DML, CMAP of median nerve were (46.00 +/- 4.32) m/s, (40.66 +/- 2.65) m/s, (7.98 +/- 1.05) microV, (4.28 +/- 0.63) ms, and (6.32 +/- 1.54) mV respectively. The MCV, CMAP, DML of common peroneal nerve were (48.49 +/- 3.25) m/s, (3.21 +/- 1.99) mV, (7.32 +/- 1.65) ms respectively. The SCV, SNAP of sural nerve were (36.48 +/- 5.20) m/s, (2.15 +/- 1.22) microV respectively. These parameters gradually recovered to normal levels in 24 months after treatment. CONCLUSION: The electrophysiological abnormalities in severe N-hexane neuropathy patients can restore after treatment, and clinical prognosis is good.

Adult↗
PubMed2005

[Mutation analysis of DJ1 gene in patients with autosomal recessive early-onset Parkinsonism].

OBJECTIVE: To investigate the mutation characteristics of DJ1 gene in Chinese patients with autosomal recessive early-onset Parkinsonism (AR-EP). METHODS: Mutations of DJ1 gene were screened by polymerase chain reaction combined with DNA direct sequencing in index patients with AR-EP from 11 unrelated families. RESULTS: No pathogenetic mutations in the DJ1 gene were detected in this group. Six intronic DJ1 polymorphisms (IVS1-15T-->C, IVS4+30T-->G, IVS4+45G-->A, IVS4+46G-->A, IVS5+31G-->A, g.168-185del) were found. Three of them (IVS1-15T-->C, IVS4+45G-->A, IVS4+46G-->A) were not reported previously. CONCLUSION: DJ1 mutations were rare in Chinese patients with autosomal recessive early-onset Parkinsonism.

Adolescent↗
PubMed2005

[Construction of the eukaryotic expression vector of MJD1 and its expression in SH-SY5Y cells].

OBJECTIVE: To construct the eukaryotic expression vector of MJD1 with normal copies of CAG trinucleotide repetition and MJD1 with CAG trinucleotide repetition expansion mutation respectively, and to determine whether the polyglutamine expansion in ataxin-3 could lead to the formation of intranuclear aggregation. METHODS: The coding sequence of wild-type MJD1 and mutant MJD1 was amplified by PCR from pAS2-1-MJD20Q and pAS2-1-MJD68Q respectively. After being digested with BamH I and Hind III, the PCR products were inserted into pcDNA3. 1-Myc-His(-) B. The recombinant plasmids pcDNA3.1-Myc-His(-) B-MJD20Q and pcDNA3.1-Myc-His(-) B-MJD68Q were identified by enzyme digestion analysis and DNA sequencing. The recombinant plasmid was transfected into SH-SYSY cells and the expression of MJD1 in the transfected cells was analyzed by Western blot. The immunofluorescence of the transfected cells was examined using a confocal microscope to observe the formation of intranuclear aggregation. RESULTS: Enzyme digestion analysis and DNA sequencing showed that the target gene was cloned into pcDNA3. 1-Myc-His(-) B. The expression of MJD1 in the transfected cells was confirmed by Western blot; The SH-SY5Y cells transfected with pcDNA3. 1-Myc-His(-) B-MJD68Q showed the formation of intranuclear aggregation, but the cells transfected with pcDNA3.1-Myc-His(-) B-MJD20Q did not show such phenomenon. CONCLUSION: The eukaryotic expression vectors of MJD1 has been successfully constructed; The polyglutamine expansion in ataxin-3 could lead to the formation of intranuclear aggregation.

Ataxin-1↗
PubMed2004

Truncated ClC-1 mRNA in myotonic dystrophy exerts a dominant-negative effect on the Cl current.

BACKGROUND: Muscle fiber degeneration and myotonic discharges are the hallmarks of myotonic dystrophy (DM). The molecular basis for the myotonia was recently tied to abnormal splicing of the chloride channel (ClC-1) pre-mRNA, often resulting in UAG premature termination, which leads to decreased channel protein and therefore a reduced resting chloride conductance. METHODS: The authors assessed the functional properties of two commonly occurring DM mRNA splice variants by expression in oocytes. RESULTS: Neither splice variant coded for a functional Cl- channel. Co-injection of alternative splice variants with wild-type ClC-1 cRNA reduced the current density and accelerated channel closure upon repolarization of the membrane. CONCLUSIONS: These data show that the aberrantly spliced chloride channel message exerts a dominant negative effect that may contribute to the development of myotonia.

Alternative Splicing↗
PubMed2004

Small heat-shock protein 22 mutated in autosomal dominant Charcot-Marie-Tooth disease type 2L.

Charcot-Marie-Tooth (CMT) disease is the most common inherited motor and sensory neuropathy. We have previously described a large Chinese CMT family and assigned the locus underlying the disease (CMT2L; OMIM 608673) to chromosome 12q24. Here, we report a novel c.423G-->T (Lys141Asn) missense mutation of small heat-shock protein 22-kDa protein 8 (encoded by HSPB8), which is also responsible for distal hereditary motor neuropathy type (dHMN) II. No disease-causing mutations have been identified in another 114 CMT families.

Charcot-Marie-Tooth Disease↗
PubMed2004

Myotonic dystrophy type 1 is associated with nuclear foci of mutant RNA, sequestration of muscleblind proteins and deregulated alternative splicing in neurons.

Myotonic dystrophy type 1 (DM1) is caused by expansion of a CTG repeat in the DMPK gene. In skeletal muscles, DM1 may involve a novel, RNA-dominant disease mechanism in which transcripts from the mutant DMPK allele accumulate in the nucleus and compromise the regulation of alternative splicing. Here we show evidence for a similar disease mechanism in brain. Examination of post-mortem DM1 tissue by fluorescence in situ hybridization indicates that the mutant DMPK mRNA, with its expanded CUG repeat in the 3'-untranslated region, is widely expressed in cortical and subcortical neurons. The mutant transcripts accumulate in discrete foci within neuronal nuclei. Proteins in the muscleblind family are recruited into the RNA foci and depleted elsewhere in the nucleoplasm. In parallel, a subset of neuronal pre-mRNAs show abnormal regulation of alternative splicing. These observations suggest that CNS impairment in DM1 may result from a deleterious gain-of-function by mutant DMPK mRNA.

Adult↗
PubMed2004

An Rb-Skp2-p27 pathway mediates acute cell cycle inhibition by Rb and is retained in a partial-penetrance Rb mutant.

It is believed that Rb blocks G1-S transition by inhibiting expression of E2F regulated genes. Here, we report that the effects of E2F repression lag behind the onset of G1 cell cycle arrest in timed Rb reexpression experiments. In comparison, kinase inhibitor p27Kip1 protein accumulates with a faster kinetics. Conversely, Rb knockout leads to faster p27 degradation. Rb interacts with the N terminus of Skp2, interferes with Skp2-p27 interaction, and inhibits ubiquitination of p27. Disruption of p27 function or expression of the Skp2 N terminus prevents Rb from causing G1 arrest. A full-penetrance, inactive Rb mutant fails to interfere with Skp2-p27 interaction but, interestingly, a partial-penetrance Rb mutant that is defective for E2F binding retains full activity in inhibiting Skp2-p27 interaction and can induce G1 cell cycle arrest with wild-type kinetics. These results identify an Rb-Skp2-p27 pathway in Rb function, which may be involved in inhibition of tumor progression.

Animals↗
PubMed2004

Conjugate-gradient optimization method for orbital-free density functional calculations.

Orbital-free density functional theory as an extension of traditional Thomas-Fermi theory has attracted a lot of interest in the past decade because of developments in both more accurate kinetic energy functionals and highly efficient numerical methodology. In this paper, we developed a conjugate-gradient method for the numerical solution of spin-dependent extended Thomas-Fermi equation by incorporating techniques previously used in Kohn-Sham calculations. The key ingredient of the method is an approximate line-search scheme and a collective treatment of two spin densities in the case of spin-dependent extended Thomas-Fermi problem. Test calculations for a quartic two-dimensional quantum dot system and a three-dimensional sodium cluster Na216 with a local pseudopotential demonstrate that the method is accurate and efficient.

Journal Article↗
PubMed2004

ABCA1 is required for normal central nervous system ApoE levels and for lipidation of astrocyte-secreted apoE.

ABCA1 is an ATP-binding cassette protein that transports cellular cholesterol and phospholipids onto high density lipoproteins (HDL) in plasma. Lack of ABCA1 in humans and mice causes abnormal lipidation and increased catabolism of HDL, resulting in very low plasma apoA-I, apoA-II, and HDL. Herein, we have used Abca1-/- mice to ask whether ABCA1 is involved in lipidation of HDL in the central nervous system (CNS). ApoE is the most abundant CNS apolipoprotein and is present in HDL-like lipoproteins in CSF. We found that Abca1-/- mice have greatly decreased apoE levels in both the cortex (80% reduction) and the CSF (98% reduction). CSF from Abca1-/- mice had significantly reduced cholesterol as well as small apoE-containing lipoproteins, suggesting abnormal lipidation of apoE. Astrocytes, the primary producer of CNS apoE, were cultured from Abca1+/+, +/-, and -/- mice, and nascent lipoprotein particles were collected. Abca1-/- astrocytes secreted lipoprotein particles that had markedly decreased cholesterol and apoE and had smaller apoE-containing particles than particles from Abca1+/+ astrocytes. These findings demonstrate that ABCA1 plays a critical role in CNS apoE metabolism. Since apoE isoforms and levels strongly influence Alzheimer's disease pathology and risk, these data suggest that ABCA1 may be a novel therapeutic target.

ATP Binding Cassette Transporter 1↗
PubMed2004

A novel mutation in KCNQ2 gene causes benign familial neonatal convulsions in a Chinese family.

Benign familial neonatal convulsions (BFNC) are a rare autosomal dominant inherited epilepsy syndrome. Two voltage-gated potassium channel genes, KCNQ2 on chromosome 20q13.3 and KCNQ3 on chromosome 8q24, have been identified as the genes responsible for benign familial neonatal convulsions. By linkage analysis and mutation analysis of KCNQ2 gene, we found a novel frameshift mutation of KCNQ2 gene, 1931delG, in a large Chinese family with benign familial neonatal convulsions. This mutation is located in the C-terminus of KCNQ2, in codon 644 predicting the replacement of the last 201 amino acids with a stretch of 257 amino acids showing a completely different sequence. An unusual clinical feature of this family is that the seizures of every patient did not remit until 12 to 18 months. This is the first report of KCNQ2 gene mutation in China.

Base Sequence↗
PubMed2004

Differential gene expression patterns by oligonucleotide microarray of basal versus lipopolysaccharide-activated monocytes from cord blood versus adult peripheral blood.

Monocytes (Mo) are critically important in the generation of inflammatory mediators, cytokines/chemokines, and regulation of innate and adaptive immune responses. We and others have previously demonstrated significant dysregulated cytokine gene expression and protein production and in vitro functional activities of activated cord blood (CB) vs adult peripheral blood (APB) mononuclear cells (MNC). In this study, we compared, by oligonucleotide microarray, the differential gene expression profiles of basal and LPS-activated APB vs CB Mo. We demonstrated a significant increase in the gene expression of several important functional groups of CB genes compared with basal levels including cytokine (IL-12p40, 5-fold), immunoregulatory (signaling lymphocytic activation molecule, 4-fold), signal transduction (Pim-2, 3-fold), and cell structure (Rho7, 4-fold) among others. Furthermore, there was significantly differentially amplified gene expression in LPS-activated APB vs LPS-activated CB Mo, including cytokine (G-CSF, 14-fold), chemokine (macrophage-inflammatory protein 1alpha, 5-fold), immunoregulatory (MHC DRB1, 5-fold), transcription factor (JunB, 4-fold), signal transduction (STAT4, 5-fold), apoptotic regulation (BAX, 5-fold), and cell structure (ladinin 1, 6-fold) among others. These results provide insight into the molecular basis for normal genetic regulation of Mo development and cellular function and differential inflammatory and innate and adaptive immune responses between activated CB and APB Mo.

Adjuvants, Immunologic↗