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N Zhong

Publications and source records attributed to N Zhong.

At least 73 records · Page 4Linked to original sources
PubMed1998

Compound heterozygous genotype is associated with protracted juvenile neuronal ceroid lipofuscinosis.

We present a clinicopathological study and the first molecular genetic analysis of a family with 2 siblings affected by a rare, protracted form of juvenile neuronal ceroid lipofuscinosis (JNCL). Molecular genetic studies showed that both siblings, in addition to being heterozygous for the 1.02-kb CLN3 deletion, a common mutation in JNCL, also had a G-to-A missense mutation at nucleotide 1,020 of the CLN3 cDNA sequence on the non-1.02-kb deletion chromosomes. This point mutation resulted in a substitution of glutamic acid by lysine at position 295 of the CLN3 protein. Thus, a single point mutation at residue 295 of the CLN3 protein in protracted JNCL may underlie the phenotype in this form, which differs from that in classic JNCL.

Adult↗
PubMed1998

Molecular screening of Batten disease: identification of a missense mutation (E295K) in the CLN3 gene.

Batten disease, the juvenile form of neuronal ceroid lipofuscinosis, is a prevalent neuron degenerative disorder of childhood. A 1.02-kb genomic deletion in the Batten disease gene CLN3 has been determined to be a common mutation. We developed a PCR method to screen for this deletion and tested 43 Batten disease probands. We found 36% (31/86) of Batten disease chromosomes did not carry the 1.02-kb deletion. Of the three heterozygotes for the 1.02-kb deletion, a novel G-to-A missense mutation at nucleotide 1020 of the CLN3 cDNA sequence was found on two of the non-1.02-kb deletion chromosomes. The missense mutation resulted in a substitution of glutamic acid (E) by lysine (K) at position 295 (E295 K). The E295 K mutation causes a change in predicted local protein conformation. This glutamic acid is a highly conserved acidic amino acid, being present in human, mouse, dog and yeast, which suggests it may play an important role in the function of the Batten disease protein.

Alternative Splicing↗
PubMed1998

Studies of atypical JNCL suggest overlapping with other NCL forms.

In the United States, juvenile neuronal ceroid-lipofuscinosis (JNCL) is the most common form of NCL. This study analyzed 191 cases, diagnosed on the basis of age-at-onset, clinical symptomatology, and pathologic findings. Twenty percent (40/191) of these cases from 24/120 families manifested atypical clinical symptomatology and/or pathologic findings (typical revealed fingerprints and atypical revealed mixed inclusions, or only curvilinear or granular profiles) and, therefore, represent variant forms of JNCL. Those patients in the study with typical JNCL were a uniform group of cases, whereas the atypical were heterogenous and were divided into 8 subgroups based on the clinicopathologic findings. Forty-three families were analyzed (27 typical, 16 atypical) for the common 1.02 kb deletion and several pedigrees for novel mutations. In typical JNCL the common 1.02 kb deletion in both alleles (homozygous) were observed in 23/27, and only 1 allele (heterozygous) was exhibited in 4/27 families. In atypical JNCL families, 5/16 were heterozygous for the common 1.02 kb deletion. None of the remaining 11/16 families had the common 1.02 kb deletion in either allele, but in 9/11 cases the palmitoyl-protein thioesterase (PPT) levels were deficient. In cases where the mutation in CLN3 gene has not been identified, several possibilities may exist. The phenotype may be caused by a yet undefined mutation in CLN3 or may be due to overlapping with other forms of NCL.

Adolescent↗
PubMed1998

Two common mutations in the CLN2 gene underlie late infantile neuronal ceroid lipofuscinosis.

Late infantile neuronal ceroid lipofuscinosis (LINCL) is one of the most common pediatric neuronal degenerative disorders. A candidate gene underlying this disease, designated CLN2, was recently cloned and the gene product was characterized as a lysosomal pepstatin-insensitive carboxypeptidase (LPIC). Four mutations were identified in CLN2 from three unrelated LINCL individuals. To investigate further the mutation frequency in LINCL, we screened 16 LINCL probands for these four mutations. The previously reported intronic mutation, T523-1 G-->C. was found in 56% (9/16) of the cases, of which two were homozygous and accounted for 34% (11/32) of LINCL chromosomes. The previously reported nonsense mutation, 636 C-->T leading to R208stop, was found in 31% (5/16) of the cases, including one homozygote and accounted for 19% (6/32) of LINCL chromosomes. Two previously described missense mutations, 1107 T-->C and 1108 G-->A, were not detected in any of these 16 probands. In total, the two observed mutations, T523-1 G-->C and 636 C-->T, accounted for 53% (17/32) of LINCL alleles. Thus, one or both mutations were seen in 11 (69%) cases and no mutation has yet been identified in five. Our finding that these two mutations are common in LINCL cases adds further evidence in support of the idea that dysfunction of LPIC underlies LINCL. Positive molecular testing can now complement clinical diagnosis of LPIC and will allow for pre-natal diagnosis for subsequent pregnancies.

Aminopeptidases↗
PubMed1998

[Determination of normal values and analysis of their relation for distortion product otoacoustic emission in guinea pigs].

In the present paper, we measured systematically the normal values of 1, 2, 4, 6 kHz distortion product otoacoustic emission (DPOAE) in guinea pigs and analyzed the relation of these values. The incidence of DPOAE in all frequencies were 100%. The amplitudes of DPOAE above 2 kHz were large than 25 dB SPL, but the amplitude of 1 kHz was lower than one of above 2 kHz. The threshold of above 2 kHz were lower than one of 1 kHz. A trend was found that latencies of all frequencies decreases accompanied with the f2 frequencies increasing. I/0 function curves demonstrated that there was a significant relation between the amplitudes of DPOAE and the levels of primary stimuli in the statistics, that is, lower levels of primary stimuli and smaller amplitudes of DPOAE. Our results indicated that a guinea pig, whose DPOAE possessed the properties of high incidence, large amplitude and stable responsibility, was an appropriate experimental animal for studying DPOAE. In addition, this paper recommended briefly the experience about the measuring techniques for DPOAE in guinea pigs.

Acoustic Stimulation↗
PubMed1998

[Analysis of spectral history of distort-product otoacoustic emissions in subjects of transient vertebrobasilar ischemic vertigo].

Analysis of the spectral history of distrot-product otoacoustic emissions (DPOAE) was performed to evaluate the cochlear function in subjects of vertebrobasilar transient ischemic vertigo (VBTIV). Thresholds of pure tone and acoustic reflex didn't increase while the amplitudes of DPOAE decreased, and the spectral history of DPOAE rippled dramastically. 36.8% of cases were found abnormal by the amplitudes and the spectral history of DPOAE. The results confirmed that those patients with mild disfunction of cochlea can be detected by the amplitude and spectral history of DPOAE, which may be useful to differentiate the region of VBTIV.

Aged↗
PubMed1998

[A study on DPOAE in patients with diabetes mellitus].

In present experiment we tested DPOAE in 19 patients with diabetes mellitus and compared with control subjects. Results showed that DPOAE (f2 above 3 kHz) disappeared in 2 patients (3 ears) indicating cochlear lesion, both of DPOAE contralateral suppressive effects and selective attention effects significantly reduced in 4 patients (7 ears), and reversed in 3 patients (6 ears) indicating disorders existing in cortex topdown and efferent of MOCS. It was suggested that tests of DPOAE and suppression (induced by CAS and selective attention) may be useful for making early diagnosis of cochlear-pathy and auditory efferent disorders (cortex and MOCS) before retinalpathy happened. This study on DPOAE provided important evidence for early diagnosis and early treatment of diabetic complications.

Acoustic Stimulation↗
PubMed1998

[Prophylactic and therapeutic effects of beclomethasone inhalation on bronchial hyperresponsiveness and asthma: a randomized, double-blind, parallel-group controlled trial].

OBJECTIVE: To better understand the effects of corticosteroid inhalation on asthma and asymptomatic bronchial hyperresponsiveness (BHR). METHODS: A double blind, randomized study was conducted to compare the effects of beclomethasone dry powder (BDP, 600 micrograms/day) inhalation with placebo on BHR and asthmatic symptoms in 59 students (12-18 yrs) for one year. RESULTS: After one year of treatment, lgPD20-FEV1 increased significantly in asthmatics in the BDP group (0.385 +/- 0.424 vs 1.187 +/- 0.603 mumol histamine). Thirty percent of asthmatics in BDP group and 86% in the control group developed symptoms in this year (P = 0.076). There was no significant difference in lgPD20-FEV1 between the BDP and the control group in asymptomatic BHR students. However, none in the BDP group of asymptomatic BHR students developed asthmatic symptoms compared with 3 cases (15%) in control group. The accumulative symptom score showed significant difference between the BDP group and the control group in asymptomatic BHR students (1.50 +/- 2.54 vs 5.58 +/- 6.22, P < 0.01). CONCLUSION: The results suggested that BDP could significantly relieve the severity of BHR and symptoms in asthmatics, and could have some prophylactic effects on the development of asthma in those with asymptomatic BHR.

Administration, Inhalation↗
PubMed1998

[Effect of inhaled-corticosteroids on the mRNA expressions of endothelin-1 and endothelin converting enzyme in bronchial asthma].

OBJECTIVE: To investigate the expressions of endothelin-1(ET-1) and endothelin converting enzyme (ECE) mRNA in bronchial mucosal biopsis from asthmatics, and the effect of inhaled-corticosteroids on the expressions of ET-1 and ECE genes. METHOD: The expressions of ET-1 and ECEmRNA in bronchial mucosal tissue were evaluated by reverse transcription DNA polymerase chain reaction (RT-PCR); With fibro bronchoscopy, the naked-eye inflammatory severity and inflammatory score of bronchial mucoses were recorded. RESULT: (1) The expression level of ET-1 mRNA was 0.86 +/- 0.06 in non-steroids-treated group and 0.14 +/- 0.06 in control non-asthmatic group. The expression of ECE mRNA in non-steroid group was 0.31 +/- 0.04, and 0.30 +/- 0.05 in control group, P = 0.238. (2) The ET-1 and ECE mRNA expressions were 0.22 +/- 0.01 and 0.16 +/- 0.01 respectively in steroid treated group. (3) The naked-eye bronchial mucosal inflammatory score was 6.0 +/- 1.9 in non-steroids treated group, moreover, the expression of ET-1 mRNA was positively correlated with the score (r = 0.78, P < 0.05). CONCLUSION: There was markedly higher ET-1 mRNA expression in the bronchial mucosa in asthmatics, but the ECE mRNA expression was unchanged significantly; Inhaled corticosteroids obviously inhibited both ET-1 mRNA and ECE mRNA expressions in bronchial mucosa, which may be one of the anti-inflammatory mechanisms of inhaled-corticosteroid in management of bronchial asthma.

Adult↗
PubMed1998

[L-arginine prolonged the efficacy of inhaled nitric oxide on the inhibition of pulmonary hypertension].

OBJECTIVE: The aim of this study is to investigate the effects of L-arginine, the substrate of nitric oxide (NO) on the duration of nitric oxide selective decrease of pulmonary hypertension. To assess whether combined use of inhaled nitric oxide and venous administered L-arginine can improve the efficacy of inhaled NO on the inhibition of hypoxia induced pulmonary hypertension. METHOD: Eight pigs with hypoxic pulmonary hypertension received either inhaled NO(12-15 ppm) for 10 minutes or inhaled NO plus venous administrered L-arginine(10 g), then hemodynamic parameters were recorded. RESULT: NO inhalation significantly inhibited hypoxic induced pulmonary hypertension with pulmonary arterial pressure decreasing from 4.2 +/- 0.4 kPa to 2.5 +/- 0.5 kPa(P < 0.01) and pulmonary vascular resistance from 56 +/- 25 kPa.s.L-1 to 31 +/- 13 kPa.s.L-1(P < 0.01), but this just lasted for 3-5 minutes after stopping inhalation; combined use of L-arginine infusion did not further decrease pulmonary arterial pressure, but significantly prolonged the inhibitory effect of inhaled NO on pulmonary hypertension (20 times) as compared with inhaled NO only. CONCLUSION: With the existence of exogenous NO, supplement of NO substrate L-arginine produced a synesgetic inhibition effect on hypoxic induced pulmonary hypertension.

Administration, Inhalation↗
PubMed1998

[The changes of EG1 and EG2 positive eosinophils and their clinical significance in asthmatics].

OBJECTIVE: To evaluate the significance of EG1 or EG2 positive eosinophils in relating to the severity of asthma. METHOD: EDTA-anticoagulated venous blood were treated by FOG method, and FTTC-conjugated monoclonal antibodies were added. Flow cytometry technique was used. RESULT: EG1 and EG2 positive eosinophils increased significantly in patients with acute asthma (n = 29) as compared with control (n = 13) and COPD (n = 12), P < 0.05. There were significant correlation of the mean fluorescence intensity(MFI) between EG1, EG2 and the degree of the symptom. CONCLUSION: There is a significant increase of activated eosinophils in peripheral blood in asthmatics, the expression of EG1 and EG2 positive eosinophils correlated well with the severity of symptom in asthmatics. EG1 and EG2, as the marker for eosinophils activity, may be sensitive and specific in evaluating the severity of asthmatics symptom.

Adolescent↗
PubMed1998

[Thoracoscopic lung reduction surgery for emphysema].

OBJECTIVE: To study the surgical treatment of emphysema. METHOD: Five patients with severe diffused pulmonary emphysema underwent surgical bilateral lung volume reduction by video-assisted thoracoscopy. All patients were male and their age ranged from 60 to 71 years (mean 64.3 years). Before surgery, 5 patients required supplement oxygen with exertion and one oxygen supplement at rest. Preoperative and postoperative assessments included standard pulmonary function studies, chest CT scan and quantitative nuclear lung perfusion and ventilation scan. Wedge resection was performed were in 3 patients, simple plication in 1, and combined wedge resection and plication in 1. There were no early or late mortality and no requirement for immediate postoperative ventilatory assistance. RESULT: Follow-up ranged from 10 to 12 months. After surgery the mean forced expiratory volume in 1 second (FEV(1)) was significantly increased from 0.46 L to 1.13 L (P < 0.001) and the mean forced vital capacity (FVC) was markedly improved from 1.74 L to 2.93 L (P < 0.001). Pulmonary compliance was significantly improved and resistance of airway decreased (P < 0.001). The mean distance during 6-min walk test increased from 10 m to 400 m in 4 patients. CONCLUSION: Thoracoscopic bilateral lung volume reduction is an effective and safe technique for patients with severe emphysema. It can relieve dyspnea and improve in excise tolerance and quality of life.

Aged↗
PubMed1997

Expression studies of CLN3 protein.

Expression of the gene for Batten disease (CLN3) was studied in Escherichia coli and in a cell-free rabbit reticulocyte expression systems. A full-length recombinant fusion CLN3 protein was not produced in the bacterial systems used. However, both N-terminal fragment encompassing 246 amino acids and short C-terminal fragment containing 428-438 amino acids of the CLN3 protein were successfully overexpressed in bacteria. Further studies showed that the C-terminal sequence of the CLN3 protein corresponding to the 356-438 amino acid residues was responsible for inhibition of protein synthesis in bacteria. The full-length CLN3 gene product was readily synthesized in vitro in the cell-free rabbit reticulocyte expression system. The product obtained, corresponding to core CLN3 protein, showed an approximate molecular weight of 43 kDa. Immunoprecipitation of this product with pAb to 4-19 amino acids of the CLN3 protein allows us to suggest that CLN3 protein translation starts at Met-1.

Adolescent↗
PubMed1997

[Effects of chronic hypoxia on the expression of oncogene jun fos and myb mRNA in rat lung].

This paper is to investigate the expression of oncogene jun fos and myb mRNA in the lung of rats exposed to chronic hypoxia. 15 SD rats were put in low oxygen chamber (FiO2 = 0.1), 8 hrs daily for 1, 2 and 3 weeks. Five rats breathing room air served as control. Oncogene expression in lung tissue assessed by the use of in situ hybridization. The results showed that (1) there was a slight expression of jun mRNA but not fos and myb mRNA in the control normoxic rats' lung; (2) it was found that a less expression of jun mRNA in lung after 1 week hypoxia, but after 2 week hypoxia jun mRNA elevated again and significantly increased after 3 week hypoxia as compared with that in normoxia; (3) the oncogene myb mRNA expression showed significant increase in 1 and 2 week hypoxia and returned to normal status in 3 week hypoxia; (4) after 1 to 3 week hypoxia, a significant increased expression of fos mRNA was found as compared with that in normoxia. It is suggested hypoxia may induce increased expression of proto-oncogene jun myb and fos, which may be related to proliferation of pulmonary arterial smooth muscle cells and fibroblasts.

Animals↗
PubMed1997

[A study on the contralateral suppressive effects of distortion product otoacoustic emissions].

To investigate the physiological properties of contralateral suppressive effects of otoacoustic emissions, the effects of contralateral norrow band noise (NBN) on distortion product otoacoustic emissions (DPOAE) in 23 young subjects (46 ears) with normal hearing were studied using ILO92 otodynamic system. The results showed: 1. The amplitude of DPOAE (2f1-f2) was significantly reduced as the intensity of contralateral NBN increased. They were in significant minus correlation (F2 from 1 to 6 kHz, coefficients were -0.49(-)-0.24, all P < 0.05, the slope 0.26-0.08 dB/10 dB); 2. The suppressive effect was the biggest when the primary F2 was 1 kHz or 2 kHz and between 45 dB SPL and 65 dB SPL of intensity level, and damped as primary frequency increased. The most significant reduction of DPOAE amplitude was 3.85 dB SPL; 3. When contralateral NBN was below 50 dB HL, the suppression was frequency-selective; and the most suppressive effect happened when NBN intensities were between 20 dB HL and 50 dB HL. 4. The noise floor in ipsilateral car canal has not been altered by contralateral noise (20-50 dB HL). The underlying mechanism was discussed in this study. It appears that contralateral suppressive effects of DPOAE can be used as a tool in exploring the function of medial olivocochlear system.

Acoustic Stimulation↗