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N Zhong

Publications and source records attributed to N Zhong.

At least 19 recordsLinked to original sources
PubMed2006

A double-blind, placebo-controlled study of house dust mite immunotherapy in Chinese asthmatic patients.

BACKGROUND: The purpose of this study was to determine if house dust mite immunotherapy with Alutard SQ is effective in improving symptom control and reducing rescue medication use in Chinese patients with mild to moderate allergic asthma. METHODS: This is a double-blind, placebo-controlled study involving 132 asthmatic subjects aged 6-45 years recruited from three different regions of Mainland China. Subjects were given a 52-week course of immunotherapy with Dermatophagoides pteronyssinus extract (Alutard Der p, ALK-Abelló, Hørsholm, Denmark) or placebo while their dose of inhaled corticosteroids (ICS) was maintained. RESULTS: 129 subjects (64 in active group) completed the study. The symptom scores began to diverge at week 29 with the immunotherapy group showing a significantly lower score until week 48 (P = 0.018). Immunotherapy resulted in a significant decline in symptom (P = 0.002) and medication (P = 0.007) scores during the second half of the treatment period. Both groups showed significant improvement in peak flow rate and bronchial hyperresponsiveness. Serum eosinophil cationic protein (ECP) also decreased in both groups of subjects, but peripheral blood eosinophil count remained unchanged. Skin test response decreased in actively treated subjects only, but Der p-specific immunoglobulin E (IgE) remained unchanged. Immunotherapy resulted in a significantly greater improvement in self-evaluation scores (P < 0.01). CONCLUSIONS: One year treatment with Alutard SQ house dust mite immunotherapy significantly reduced symptoms and medication use in asthmatic subjects. This was associated with a greater subjective improvement in asthma control.

Adolescent↗
PubMed2005

Progression of early postnatal retinal pathology in a mouse model of neuronal ceroid lipofuscinosis.

PURPOSE: Accumulation of autofluorescent storage material in the CNS is a hallmark of neuronal ceroid lipofuscinosis (NCL, Batten disease). Since the retina is generally the first CNS target affected in NCL and could serve as a means to assess early disease progression as well as potential therapeutic responses, we followed the course of postnatal retinal pathology in tissues from the CLN8 (mnd) mouse model of NCL. RESULTS: Cytoplasmic inclusions in the retinal ganglion cell (RGC) layer were shown by periodic acid schiff stain by P7. TUNEL measurements of cell death became significant at P21 (P<0.001) with most cell death occurring in the photoreceptor layer. Significant autofluorescence and RGC hypertrophy were evident in mnd mice at P0, prior to eye opening or significant cell death. CONCLUSION: An increased understanding of the timing, location, and characteristic retinal pathologies of Batten disease may lead to diagnostic and therapeutic advances in the clinical setting.

Aging↗
PubMed2003

Expression of matrix metalloproteinases MMP-9 within the airways in asthma.

The matrix metalloproteinase (MMP) enzymes MMP-9, have relevance to chronic structural airway changes in asthma, which can be generated by structural and inflammatory cells, and have the ability to degrade proteoglycans and thus potentially enhance airway fibrosis and smooth muscle proliferation through their ability to release and activate latent, matrix-bound growth factors. Immunostaining for MMP-9 was undertaken in acetone-fixed and glycolmethacrylate-embedded endobronchial biopsy specimens obtained by fibreoptic bronchoscopy under local anaesthesia. The findings from 30 asthmatic subjects were compared with those from 18 chronic obstructive pulmonary disease (COPD) subjects and 10 healthy controls. Meanwhile, pulmonary function test and airway responsiveness were performed. Immunoreactivity for MMP-9 was assessed by an image analysis system. The biopsy specimens from asthmatic subjects contained significantly more eosinophils (P < 0.001) than those from COPD subjects, and healthy control did not contain eosinophils. MMP-9 immunoreactivity could be identified in endobronchial biopsy specimens from all the asthmatic subjects and 40% ofthe COPD subjects, but could not be identified in healthy controls. Gelatinase B (MMP-9) immunoreactivity was located in bronchial epithelium and extracellular matrix in submucosa, prominent in denuded epithelium. The immunohistochemical score for MMP-9 was significantly correlated with eosinophilic number in bronchial mucosa. FEV1% predicted FEV1/FVC (%) (r = 0.52, 0.41, 0.37, respectively P < 0.01 did not correlate with PD20 FEV1 from asthmatic subjects. MMP-9 is expressed by bronchial epithelium and may be a important factor for eosinophil infiltraed into airway from asthma subjects.

Adult↗
PubMed2003

Maintenance therapy with budesonide and formoterol in chronic obstructive pulmonary disease.

Lung function in chronic obstructive pulmonary disease (COPD) can be improved acutely by oral corticosteroids and bronchodilators. Whether clinical improvement can be maintained by subsequent inhaled therapy is unknown. COPD patients (n=1,022, mean prebronchodilator forced expiratory volume in one second (FEV1) 36% predicted) initially received formoterol (9 microg b.i.d.) and oral prednisolone (30 mg o.d.) for 2 weeks. After this time, patients were randomised to b.i.d. inhaled budesonide/formoterol 320/9 microg, budesonide 400 microg, formoterol 9 microg or placebo for 12 months. Postmedication FEV1 improved by 0.21 L and health-related quality of life using the St George's Respiratory Questionnaire (SGRQ) by 4.5 units after run-in. Fewer patients receiving budesonide/formoterol withdrew from the study than those receiving budesonide, formoterol or placebo. Budesonide/formoterol patients had a prolonged time to first exacerbation (254 versus 96 days) and maintained higher FEV1 (99% versus 87% of baseline), both primary variables versus placebo. They had fewer exacerbations (1.38 versus 1.80 exacerbations per patient per year), had higher prebronchodilator peak expiratory flow, and showed clinically relevant improvements in SGRQ versus placebo (-7.5 units). Budesonide/formoterol was more effective than either monocomponent in both primary variables. Budesonide/formoterol in a single inhaler (Symbicort) maintains the benefit of treatment optimisation, stabilising lung function and delaying exacerbations more effectively than either component drug alone or placebo.

Administration, Inhalation↗
PubMed2001

Roles for mitochondrial and reverse mode Na+/Ca2+ exchange and the plasmalemma Ca2+ ATPase in post-tetanic potentiation at crayfish neuromuscular junctions.

We have explored the processes regulating presynaptic calcium concentration ([Ca(2+)](i)) in the generation of post-tetanic potentiation (PTP) at crayfish neuromuscular junctions, using spectrophotometric dyes to measure changes in [Ca(2+)](i) and [Na(+)](i) and effects of inhibitors of Ca(2+)-transport processes. The mitochondrial Na(+)/Ca(2+) exchange inhibitor CGP 37157 was without effect, whereas the reverse mode plasmalemmal Na(+)/Ca(2+) exchange inhibitor KB R7943 reduced PTP and Ca(2+) accumulation caused by increased [Na(+)](i). Exchange inhibitory peptide and C28R2 had opposite effects, consistent with their block of the plasma membrane Ca(2+) ATPase. All drugs except CGP 37157 reduced Ca(2+) accumulation caused by Na(+) accumulation, which occurred on block of the Na(+)/K(+) pump, acting in proportion to their effects on plasmalemmal Na(+)/Ca(2+) exchange. We find no role for mitochondrial Na(+)/Ca(2+) exchange in presynaptic Ca(2+) regulation. The plasma membrane Na(+)/Ca(2+) exchanger acts in reverse mode to admit Ca(2+) into nerve terminals during and for some minutes after tetanic stimulation, while at the same time the plasma membrane Ca(2+) ATPase operates as an important Ca(2+) removal process. The interplay of these two Ca(2+) transport processes with Na(+)-independent mitochondrial Ca(2+) fluxes and the plasmalemma Na(+)/K(+) pump determines the magnitude of tetanic [Ca(2+)](i) accumulation and potentiation of excitatory transmission, and the post-tetanic time courses of decay of elevated [Ca(2+)](i) and PTP.

Action Potentials↗
PubMed2001

Phosphorylation and local presynaptic protein synthesis in calcium- and calcineurin-dependent induction of crayfish long-term facilitation.

Long-term facilitation at the crayfish opener muscle is elicited by prolonged high frequency stimulation, and arises from an increase in functional active zones, resulting in increased transmitter release. LTF induction depends critically upon presynaptic calcium accumulation and calcineurin (PP2B) activity. The protein synthesis dependence of this synaptic strengthening was investigated. LTF occurred without transcription, but the translation inhibitors cycloheximide and anisomycin, or local presynaptic injection of mRNA cap analog m7GpppG, impaired LTF expression. Both MAP kinase and phosphatidylinositol 3-OH kinase (PI3K) activation are implicated in this rapamycin-sensitive synaptic potentiation. This study defines an important role for protein synthesis in the expression of activity-dependent plasticity, and provides mechanistic insight for the induction of this process at presynaptic sites.

Animals↗
PubMed2001

Pheno/genotypic correlations of neuronal ceroid lipofuscinoses.

The neuronal ceroid lipofuscinoses (NCL) are a large group of autosomal recessive lysosomal storage disorders with both enzymatic deficiency and structural protein dysfunction. Previously, diagnosis of NCL was based on age at onset and clinicopathologic (C-P) findings, classified as 1) infantile (INCL), 2) late infantile (LINCL), 3) juvenile (JNCL), and 4) adult (ANCL). Most patients with NCL have progressive ocular and cerebral dysfunction, including cognitive/motor dysfunction and uncontrolled seizures. After reviewing 319 patients with NCL, the authors found that 64 (20%) did not fit into this classification of NCL. With research progress, four additional forms have been recognized: 5) Finnish, 6) Gypsy/Indian, and 7) Turkish variants of LINCL and 8) northern epilepsy, also known as progressive epilepsy with mental retardation. These eight NCL forms resulted from 100 different mutations on genes CLN1to CLN8 causing different phenotypes (http://www.ucl.ac.uk/ncl). The genes CLN1 and CLN2 encode lysosomal palmitoyl protein thioesterase and tripeptidyl peptidase 1. The function of CLN3, CLN5, and CLN8 gene-encoded products is unknown, although their predicted amino acid sequences suggest they have a transmembrane topology. The diagnosis of NCL is based on C-P findings, enzymatic assay, and molecular genetic testing. Before biochemical and genetic tests are conducted, ultrastructural studies (i.e., blood [buffy coat] or punch biopsies [skin, conjunctiva]) must be performed to confirm the presence and nature of lysosomal storage material (fingerprint or curvilinear profiles or granular osmiophilic deposits). The recognition of variable onset from infancy to middle age supersedes the traditional emphasis on age-related NCL forms.

Age of Onset↗
PubMed2001

Elevated plasma amyloid beta-peptide 1-42 and onset of dementia in adults with Down syndrome.

We compared levels of plasma amyloid beta-peptides Abeta1-42 and Abeta1-40 in 108 demented and nondemented adults with Down syndrome (DS) and 64 adults from the general population. Abeta1-42 and Abeta1-40 levels were significantly higher in adults with DS than in controls (P=0.0001). Compared to nondemented adults with DS, Abeta1-42 levels in demented adults with DS were selectively increased by 26% (28.2 pg/ml vs. 22.4 pg/ml, P=0.004). In addition, mean plasma levels of Abeta1-42 were 22% higher in DS cases with the apolipoprotein varepsilon4 allele than in DS subjects without an varepsilon4 allele (25.9 pg/ml vs. 21.2 pg/ml, P=0.01), while mean plasma levels of Abeta1-40 did not vary by APOE genotype. These results support the hypothesis that Abeta1-42 plays an important role in the pathogenesis of dementia associated with DS, as it does in Alzheimer's disease, and that variations in plasma levels may be related to disease progression.

Adult↗
PubMed2001

Neuronal ceroid lipofuscinoses: classification and diagnosis.

The neuronal ceroid lipofuscinoses (NCLs) are neurodegenerative disorders characterized by accumulation of ceroid lipopigment in lysosomes in various tissues and organs. The childhood forms of the NCLs represent the most common neurogenetic disorders of childhood and are inherited in an autosomal-recessive mode. The adult form of NCL is rare and shows either an autosomal-recessive or autosomal dominant mode of inheritance. Currently, five genes associated with various childhood forms of NCLs, designated CLN1, CLN2, CLN3, CLN5, and CLN8, have been isolated and characterized. Two of these genes, CLN1 and CLN2, encode lysosomal enzymes: palmitoyl protein thioesterase 1 (PPT1) and tripetidyl peptidase 1 (TPP1), respectively. CLN3, CLN5, and CLN8 encode proteins of predicted transmembrane topology, whose function has not been characterized yet. Two other genes, CLN6 and CLN7, have been assigned recently to small chromosomal regions. Gene(s) associated with the adult form of NCLs (CLN4) are at present unknown. This study summarizes the current classification and new diagnostic criteria of NCLs based on clinicopathological, biochemical, and molecular genetic data. Material includes 159 probands with NCL (37 CLNI, 72 classical CLN2, 10 variant LINCL, and 40 CLN3) collected at the New York State Institute for Basic Research in Developmental Disabilities (IBR) as well as a comprehensive review of the literature. The results of our study indicate that although only biochemical and molecular genetic studies allow for definitive diagnosis, ultrastructural studies of the biopsy material are still very useful. Thus, although treatments for NCLs are not available at present, the diagnosis has become better defined.

Adolescent↗
PubMed2001

Molecular genetic testing for neuronal ceroid lipofuscinoses.

Eight different NCL forms have been recognized to be encoded by genes CLN1-8. CLN1,2,3,5,and 8 have been cloned, and at least 85 mutations have been detected. Molecular technology can now be applied to genetic testing for NCLs; testing is now available in clinic diagnostic and research laboratories for CLN genes that have been cloned. Molecular genetic testing makes it possible not only to confirm clinical and pathological diagnoses but also to offer pre-symptom diagnosis and carrier screening for NCL families. In addition, DNA-based mutation analysis may predict prenatal outcome more accurately for pregnant women in NCL families.

Cloning, Molecular↗
PubMed2001

Outlook for future treatment.

Currently, no treatment is available for neuronal ceroid lipofuscinoses. The progress of human genome project will stimulate molecular cloning of unidentified genes underlying the NCLs, which will lead eventually clinical management and therapies for NCL. Characterizing the native substrate(s) for the palmitoyl-protein thioesterase-1 (PPT1) and tripeptidyl peptidase 1 (TPP1), understanding the protein functions encoded by CLN genes, and uncovering the pathological metabolic mechanism for the NCLs are the bases of designing rational treatments for the NCLs. Testing potential therapeutic agents, replacing deficient enzymes, and developing gene therapy will be the major tasks for NCL researchers.

Clinical Trials as Topic↗
PubMed2001

Producing parallel x rays with a bent-crystal monochromator and an x-ray tube.

A bent Laue monochromator and a conventional x-ray tube were used to produce a fan beam that was parallel in the plane perpendicular to the plane of the fan. The x-ray fan beam was tunable in energy and had about 12% energy bandwidth at a slice height of 5 mm when tuned to 50 keV. The beam's energy was slightly coupled to the vertical position on the beam's height. The slice height could be varied from 1 to 10 mm. The flux at 50 keV was approximately 2x10(6) photons/mm2/s with a rotating anode tungsten x-ray tube operating at 120 kVp and 100 mA. The narrow energy bandwidth of the beam produced is advantageous over a conventional divergent polychromatic beam for all radiography applications, while the parallelism of the beam enhances its intensity by about threefold and offers some advantages for computed tomography.

Biophysical Phenomena↗
PubMed2001

[Tracheobronchopathia osteochondroplastica].

OBJECTIVE: To describe the clinical manifestations of tracheobronchopathia osteochondroplastica (TO). METHODS: X-ray film, CT-scanning, lung function, fibro-bronchoscopy and histological examination were performed in all 4 patients. Clinical features were analyzed with reviewing the reported literatures. RESULTS: From June 1999 to May 2000, 4 cases of TO (male/female: 2/2, age: 35 approximately 60 yrs) were found among the 1 125 cases of fibro-bronchoscopy, with the positive rate of 0.35%. TO was characterized by cartilaginous and /or osseous submucosal nodules in the trachea and the central bronchi. Symptoms included cough (3/4), hemoptysis (2/4), hoarseness (1/4), with one case of entirely symptom free. Radiography showed no use for the diagnosis. Multiple submucosal nodules and plaques that outgrew into the lumen of the trachea were revealed by CT-scanning in 3 of 4 cases. Pulmonary function testing showed normal in 3 patients and mild obstruction in 1 patient. The bronchoscopic appearance of TO presented with multiple whitish, hard nodules projecting into the tracheal lumen from anterior and lateral walls, with sparing of the posterior wall. Pathological examination showed island of bony tissue and cartilage in the submucosa with almost intact respiratory epithelium. The symptoms and mucosal hyperemia were improved in one patient treated with beclomethasone dipropionate and theophylline for 6 months. CONCLUSIONS: As an uncommon disease, TO is often misdiagnosed or underdiagnosed. Fibro-bronchoscopy and CT scan remain the main methods for the diagnosis of TO.

Adult↗
PubMed2001

[Systemic side effects of long-term treatment with low dose inhaled corticosteroids in children with asthma].

OBJECTIVE: To observe the systemic side effects of low dose inhaled Beclomethasone dipropionate (BDP) in children with mild asthma. METHODS: 30 children with mild asthma were randomly divided into 3 groups to receive treatment with inhaled placebo (group A), BDP 200 micrograms/d (group B) and BDP 400 micrograms/d (group C) respectively. Bronchial hyperresponsiveness (BHR), height growth, bone mineral density (BMD), calcium and phosphate metabolism and hypothalamic-pituitary-adrenal axis (HPAA) function were measured. RESULTS: Inhaled BDP of 200 micrograms/d and 400 micrograms/d reduced BHR in mild asthmatic children and there was no significant difference between two groups [log(PD20-FEV1)]:(2.04 +/- 0.47) micrograms to (2.70 +/- 0.13) micrograms in group A and (1.94 +/- 0.46) micrograms to (3.15 +/- 0.18) micrograms in group B (P < 0.01). Serum osteocalcin, calcium, phosphate, alkaline phosphatase, basic cortisol and BMD didn't change significantly after BDP treatment in three groups (all P > 0.05) [In group A, B and C, concentrations serum osteocalcin were (29 +/- 12) micrograms/L, (22 +/- 6) micrograms/L, (31 +/- 11) micrograms/L, serum calcium: (2.49 +/- 0.11) mmol/L, (2.39 +/- 0.28) mmol/L, (2.20 +/- 0.35) mmol/L, serum phosphate: (1.8 +/- 0.6) mmol/L, (1.7 +/- 0.7) mmol/L, (1.5 +/- 0.4) mmol/L, radius BMD: (0.44 +/- 0.02) g/cm2, (0.42 +/- 0.05) g/cm2, (0.40 +/- 0.10) g/cm2, ulna BMD:(0.35 +/- 0.04) g/cm2, (0.36 +/- 0.08) g/cm2, (0.32 +/- 0.07) g/cm2, serum alkaline phosphatase: (410 +/- 113) U/L, (337 +/- 99) U/L, (351 +/- 122) U/L, serum basic cortisol: (350 +/- 86) nmol/L, (407 +/- 199) nmol/L, (365 +/- 71) nmol/L, lumbar spine (L4-5) BMD: (0.64 +/- 0.06) g/cm2, (0.59 +/- 0.08) g/cm2, (0.62 +/- 0.09) g/cm2 respectively]. Height growth had a trend of reducing after BDP treatment though not reaching statistical difference. Height standard deviation score (SDS): 1.1 +/- 0.7 to 1.2 +/- 0.9 in group A, 1.3 +/- 0.7 to 1.3 +/- 0.9 in group B and 1.1 +/- 0.7 to 1.0 +/- 0.7 in group C. Serum cortisol after ACTH stimulation reduced significantly in group C [(621 +/- 199) nmol/L to (482 +/- 97) nmol/L, P < 0.01]. CONCLUSION: The results of this study suggest that 200 micrograms/d BDP can reduce BHR significantly and has no detected systemic side effects in mild asthmatic children, and 400 micrograms/d BDP can reduce serum cortisol after ACTH stimulation. The long-term dose of BDP should be controlled to be less than 400 micrograms/d in children with mild asthma.

Administration, Inhalation↗
PubMed2001

[Effects of selective attention and contralateral acoustic stimulation on latency of distortion product otoacoustic emissions].

OBJECTIVE: To investigate the effects of selective attention and contralateral acoustic stimulation on latency of distortion product otoacoustic emissions. METHOD: Latency of DPOAE was recorded in 30 ears of 15 normal subjects with and without visual attention task, contralateral acoustic stimulation and combination of both forms of stimulus. RESULT: No significant change was observed in three form of stimulus. CONCLUSION: The effects of selective attention and contralateral acoustic stimulation on latency of DPOAE have to be further studied.

Acoustic Stimulation↗
PubMed2001

[An analysis of the results of central masking effect on healthy ears].

OBJECTIVE: To investigate the mechanism of Central Masking Effects(CME) and its effects on audiometry measurement. METHOD: The pure tone threshold was measured when the notest ear was masked or was in quiet respectively. We investigated the different results while giving different level maskers at the same frequency, or giving the same masker at different frequencies to find out their rules. RESULT: The CME has frequency-selective properties and sound level-selective properties. The CME appears apparently at 1 kHz and 2 kHz. At 2 kHz, the CME get the highest. When the masker was lower than 60 dB HL, the CME became higher as the masker was tuned higher; when the masker was 60 dB HL, the CME get the highest[(11.53 +/- 4.38)dB HL]. If the masker was higher than 70 dB HL, overmasking appeared. CONCLUSION: Our observations come to the conclusion that central masking correction should be made clinically when the masker is higher than 40 dB HL. 60 dB HL masker at 2 kHz can make the CME higher than 10 dB HL, thereby can be used to identify false deafness.

Adult↗
PubMed2000

Effects of intermittent hypoxia on action potential and contraction in non-ischemic and ischemic rat papillary muscle.

Although it has been reported that intermittent hypoxia had the anti-arrhythmia effect, little is known about the effects on the action potential (AP) and contraction of papillary muscle, as well as the mechanism of anti-arrhythmia. The purpose of present study is to observe the effects of intermittent hypoxia on action potential and contraction of papillary muscle in rat left ventricle simultaneously using conventional intracellular microelectrode and contraction recording. The effects of intermittent hypoxia on AP and contraction during ischemic solution perfusion were also investigated. After exposed to intermittent hypoxia (six hours daily) for 42 days (IH42), duration (APD20) of 20%, 50% (APD50) and 90% (APD90) repolarization of AP prolonged significantly compared with animals in control (Con). Effective refractory period (ERP) in IH42 also prolonged significantly. Perfused with mimic ischemic solution, the changes of electric and mechanical activities in IH42 and in 28 days exposure to intermittent hypoxia (IH28) were much smaller than that in Con and IH14. The result of the study suggested that intermittent hypoxia prolonged the APD and ERP, offered the resistance against the ischemic damage on myocardium, which may be the electrophysiological basis of the anti-arrhythmia of intermittent hypoxia.

Action Potentials↗