Serum high mobility group box chromosomal protein 1 is associated with clinicopathologic features in patients with hepatocellular carcinoma

BACKGROUND/AIMS

The role of high mobility group box chromosomal protein 1 in hepatocellular carcinoma is unknown. The aim of study was to evaluate contributions of high mobility group box chromosomal protein 1 in hepatocellular carcinoma, and analyse the correlation between high mobility group box chromosomal protein 1 and clinicopathologic outcomes.

PATIENTS/METHODS

High mobility group box chromosomal protein 1 levels were analysed by Western blot analysis. Edmondson grade, TNM stage and the Cancer of the Liver Italian Program score were used as analysis variables.

RESULTS

The serum high mobility group box chromosomal protein 1 levels in hepatocellular carcinoma (84.2 +/- 50.4 ng/ml) was significantly higher than those in chronic hepatitis (39.8 +/- 10.5 ng/ml), liver cirrhosis (40.2 +/- 11.6 ng/ml) and healthy control (7.0 +/- 5.9 ng/ml, p < 0.0001, respectively), and positive correlation were found between high mobility group box chromosomal protein 1 and alpha-fetoprotein (r = 0.952, p < 0.0001), and between high mobility group box chromosomal protein 1 and the size of tumour (r = 0.904, p < 0.0001). High mobility group box chromosomal protein 1 were significant differences among Edmondson grade I, II, III, IV; TNM stage I, II, III, IV and Cancer of the Liver Italian Program score 0-1 points, 2-4 points, > 4 points (p < 0.0001, respectively).

CONCLUSIONS

These results suggest that high mobility group box chromosomal protein 1 may be a useful marker for evaluating the tumour stage and predicting prognosis in hepatocellular carcinoma. Targeting high mobility group box chromosomal protein 1 production or release might have potential approaches for hepatocellular carcinoma treatment.

Avian influenza A (H5N1) infection in a patient in China, 2006

BACKGROUND

Highly pathogenic avian influenza H5N1 virus has caused increasing human infection in Eurasia since 2004. So far, H5N1 human infection has been associated with over 50% mortality that is partly because of delay of diagnosis and treatment.

OBJECTIVES AND METHODS

Here, we report that an H5N1 influenza virus infected a 31-year-old patient in Shenzhen in June 2006. To identify the possible source of the infection, the human isolate and other H5N1 influenza viruses obtained from poultry and wild birds in southern China during the same period of time were characterized.

RESULTS

Genetic and antigenic analyses revealed that the human H5N1 influenza virus, Shenzhen/406H/06, is of purely avian origin and is most closely related to viruses detected in poultry and wild birds in Hong Kong in early 2006.

CONCLUSIONS

The findings of the present study suggest that the continued endemicity of H5N1 influenza virus in the poultry in southern China increases the chance for introduction of the virus to humans. This highlights the importance of continued surveillance of poultry and wild birds for determining the source for human H5N1 infection.

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.

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.

X-ray microbeams: Tumor therapy and central nervous system research

Irradiation with parallel arrays of thin, planar slices of X-ray beams (microplanar beams, or microbeams) spares normal tissue, including the central nervous system (CNS), and preferentially damages tumors. The effects are mediated, at least in part, by the tissue's microvasculature that seems to effectively repair itself in normal tissue but fails to do so in tumors. Consequently, the therapeutic index of single-fraction unidirectional microbeam irradiations has been shown to be larger than that of single-fraction unidirectional unsegmented beams in treating the intracranial rat 9L gliosarcoma tumor model (9LGS) and the subcutaneous murine mammary carcinoma EMT-6. This paper presents results demonstrating that individual microbeams, or arrays of parallel ones, can also be used for targeted, selective cell ablation in the CNS, and also to induce demyelination. The results highlight the value of the method as a powerful tool for studying the CNS through selective cell ablation, besides its potential as a treatment modality in clinical oncology.

Maintenance therapy with budesonide and formoterol in chronicobstructive 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.

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.

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.

[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.

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.

[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.

[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.

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.

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.

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.

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.

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.

[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.

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.

Neuronal ceroid lipofuscinoses: research update

This study describes the phenotype/genotype analysis of 159 probands with neuronal ceroid lipofuscinosis (37 CLN1, 72 classic CLN2, 10 variant LINCL, and 40 CLN3) collected at the New York State Institute for Basic Research in Developmental Disabilities (IBR). Phenotype/genotype comparison showed that mutations in the CLN1 gene were associated with different phenotypes: infantile, late infantile, and juvenile. Two common mutations (223A-->C and 451C-->T) were found in 26 of 37 CLN1 subjects (64% of alleles examined). A nonsense point mutation, 451C-->T, was the most common in CLN1 subjects with infantile onset at 0-2 years, accounting for 50% of alleles studied. A missense point mutation, 223A-->C, was the most common among CLN1 subjects with juvenile onset older than 4 years, accounting for 45% of alleles examined. Twenty-one other CLN1 mutations were identified in 4 of 37 subjects with infantile onset, 6 of 37 with late-infantile onset, and 6 of 37 with juvenile onset. All CLN1 probands were palmitoyl-protein thioesterase (PPT)-deficient and showed granular osmiophilic deposits (GROD) at the electron microscopic (EM) level. In the group of classic CLN2 (72 probands), two common mutations were found: an intronic 3556G-->C transversion in the invariant AG of 3' splice junction in 55% of probands, and a nonsense mutation 3670C-->T in 30% of probands. Classic late-infantile onset (2-4 years) was found in 68 of 72 (95%) cases, whereas juvenile onset (> 4 years) occurred only in 4 of 72 (5%) cases. All probands had deficiency of tripeptidyl-peptidase I (TPP1) activity and, at the EM level, curvilinear profiles. Ten probands with late-infantile onset did not show mutations in the CLN2 gene, had normal TPP1 activity, and at the EM level had mixed profiles. Further studies are in progress to identify genetic defect(s) in these subjects. The CLN3 group (40 probands) was divided into two categories: classic or typical presentation, and delayed classic or atypical presentation. All CLN3 patients had onset of symptoms after 4 years of age. In 40 probands, the 1.02-kb common deletion was found in one or two alleles of the CLN3 gene. Homozygotes for the common CLN3 deletion showed the classic phenotype. The phenotype in compound heterozygotes was either the classic or the delayed classic or atypical form. Thus, our study indicates that some mutations in the CLN1 and CLN2 genes may be associated with juvenile onset of the disease process and a more benign clinical course. Interfamilial and intrafamilial variations also were found, especially in the speed of becoming blind and neurologically disabled.

Heterogeneity of late-infantile neuronal ceroid lipofuscinosis

PURPOSE

Late-infantile neuronal ceroid lipofuscinosis (LINCL), an autosomal recessively inherited lysosomal storage disorder characterized by autofluorescent inclusions and rapid progression of neurodegeneration, is due to CLN2 gene mutations. However, CLN2 mutation analysis has failed to identify some clinically diagnosed "late-infantile" NCL cases. This study was conducted to further characterize genetic heterogeneity in families affected by LINCL.

METHODS

DNA mutations in the CLN1, CLN2, and CLN3 genes that underlie INCL (infantile NCL), LINCL, and JNCL (juvenile NCL), respectively, were studied with molecular analyses.

RESULTS

A total of 252 families affected by childhood NCL were studied. Of 109 families clinically diagnosed as having LINCL, 3 were determined to have either INCL or JNCL by identification of mutation(s) in CLN1 or CLN3. Six families diagnosed initially as having JNCL were found to have LINCL based on the finding of mutations in the CLN2 gene. In addition, several novel mutations were identified.

CONCLUSIONS

Clinical and genetic heterogeneity of LINCL was demonstrated in nine LINCL families studied.

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.

Intermittent hypoxia exposure prevents mtDNA deletion and mitochondrial structure damage produced by ischemia/reperfusion injury

In the present study, polymerase chain reaction (PCR) was conducted to determine mtDNA(4834) deletion, and myocardial ultrastructure was visualized by electron microscope to see whether intermittent hypoxia (high altitude) adaptation exerts some action on mitochondria against ischemia/reperfusion injury. Myocardial ischemia/reperfusion in isolated perfused rat hearts induced severe damage to the ultrastructure of myocardial mitochondria and mtDNA4834 deletion down to 87.5% of normoxia rats. After the rats were exposed to intermittent hypoxia (5000 m; 6 h/d for 28 d), the myocardial structure was well reserved and mtDNA(4834) deletion dropped to 28.57%of control (P<0.05). It is suggested that intermittent hypoxia adaptation prevents mtDNA deletion, and preserves normal structure of mitochondria, which would be beneficial to the maintenance of normal mitochondrial function, and increases tolerance of myocardium against ischemia/reperfusion injury.

[Differentiation of human glioma cells BT-325 induced by sodium butyrate]

OBJECTIVE

To study the differentiation of human glioma cells BT-325 induced by sodium butyrate in vitro.

METHODS

BT-325 cells were treated with 1 mmol/L sodium butyrate. Flow cytometry was used to analyze the cell cycle. Cell differentiation was identified by flow cytometry and Western blot analysis.

RESULTS

After 6-8 days of sodium butyrate treatment, the differentiation characters could be observed distinctively, such as the reduced cell density, the increased cell size and the marked increase in cell process formation and cell-to-cell connection. At the same time, Western blot showed that the amount of glial fibrillary acidic protein was elevated after the sodium butyrate treatment.

CONCLUSION

Human glioma cells BT-325 could be induced to differentiation by sodium butyrate.

[Zafirlukast inhibition of leukotriene C4 induced endothelin-1 expression in human airway structural cell]

OBJECTIVE

To investigate the effects of a cysteinyl leukotriene receptor antagonist (zafirlukast) on endothelin-1(ET-1) expression in human airway epithelial cell line (16-HBE) and airway smooth muscle cells (ASMC) in response to leukotriene C4(LTC4) stimulation.

METHODS

16-HBE or ASMC was incubated with 10(-8) mol/L LTC4 and graded concentrations of zafirlukast. ET-1 level in supernatant was determined by ELISA and ET-1 mRNA expression was assessed by RT-PCR.

RESULTS

(1) LTC4 induced ET-1 mRNA expression in 16-HBE and ASMC was significantly inhibited by zafirlukast (10(-8) mol/L) 0.23 +/- 0.10 vs. 0.10 +/- 0.03 (16-HBE), t = 3.698, P = 0.034; 0.13 +/- 0.04 vs. 0.04 +/- 0.02 ASMC, t = 4.629, P = 0.019. (2) When graded concentrations of zafirlukast (0, 10(-12) mol/L, 10(-10) mol/L, 10(-8) mol/L, 10(-6) mol/L) were added to the LTC4 cultured 16-HBE and ASMC, a significant inhibition of ET-1 production was observed in both groups cultured with 10(-8) mol/L or more zafirlukast [(12.7 +/- 1.3) ng/L vs (5.5 +/- 2.6) ng/L 16-HBE, t = 4.693, P = 0.019; (7.5 +/- 1.0) ng/L vs (4.4 +/- 0.9) ng/L ASMC (t = 5.003, P = 0.007)]. (3) There was a significant negative linear correlation between ET-1 levels and zafirlukast concentrations in LTC4-treated 16-HBE and ASMC (16-HBE: r = -0.9177, P = 0.0289; ASMC: r = -0.9451, P = 0.0153).

CONCLUSIONS

These data suggest that zafirlukast inhibit LTC4-induced ET-1 over-expression 16-HBE and ASMC, which may be one of the anti-inflammatory mechanism of LTs receptor antagonists.

[Expression of GM-CSE mRNA in asthmatic patients]

OBJECTIVE

To explore non-invasive and specific markers for airway inflammation.

METHODS

RT-PCR methods were used to measure GM-CSF mRNA expression in airway mucosa and induced sputum from asthmatic patients. The correlation was analyzed between expression of GM-CSF mRNA and eosinophils or other inflammatory cells.

RESULTS

(1) The numbers of eosinophils and EG2 positive cells were (17.9 +/- 7.0) x 10(2) per mm2, and (8.9 +/- 3.0) x 10(2) per mm2 in the asthmatic group, significantly higher than those in the non-asthmatic control which were (1.9 +/- 1.0) x 10(2) per mm2, and (0.8 +/- 0.2) x 10(2) per mm2, respectively (P < 0.05). (2) The expression of GM-CSF mRNA was (1.4 +/- 0.6) in the asthmatic group, significantly higher than that in the control group (0.3 +/- 0.3) (P < 0.05), and GM-CSF mRNA expression was correlated with the numbers of EG2 positive cell (r = 0.73 and P < 0.05). (3) The percentage of eosinophils in induced sputum from asthmatic patients was (0.334 +/- 0.067), which was significantly higher than that from chronic bronchitis and control (0.021 +/- 0.004), (0.008 +/- 0.003) (P < 0.05). (4) The expression of GM-CSF mRNA in asthmatics was (0.320 +/- 0.054), significantly higher than that in chronic bronchitis and the control group (0.188 +/- 0.024 and 0.058 +/- 0.028) (P < 0.05). The expression of GM-CSF mRNA in patients with chronic bronchitis was also significantly higher than that in the control group (P < 0.05).

CONCLUSIONS

The expression of GM-CSF mRNA in induced sputum may be a relatively specific marker for airway inflammation.

Neuronal ceroid lipofuscinoses and possible pathogenic mechanism

The neuronal ceroid lipofuscinoses (NCLs) consist of eight autosomal recessively inherited storage disorders characterized by lysosomal inclusions of autofluorescent lipofuscins and rapid neurodegenerative progression. The NCLs include eight forms that result from genetic deficiency on genes CLN(1) to CLN(8), respectively: four classic forms with clinical onset at varying ages-infantile (INCL), late-infantile (LINCL), juvenile (JNCL), and adult (ANCL)-and four variants of late-infantile onset-the Finnish variant LINCL (fLINCL), Portuguese variant LINCL (pLINCL), Turkish variant LINCL (tLINCL), and progressive epilepsy with mental retardation (EPMR). The genes CLN(1) and CLN(2) have been characterized to encode lysosomal hydrolytic enzymes, but CLN(3), CLN(5), and CLN(8) encode transmembranous proteins with unknown function. Although clinical and pathological abnormalities have been recognized to be similar in all eight forms, the molecular mechanism explaining NCL pathogenesis remains unclear. In this review, the molecular basis for NCLs and a possible pathogenic mechanism are discussed.

[Tracheal transplantation]

OBJECTIVE

To treat long tracheal cancer by tracheal transplantation.

METHODS

In March 17, 1999, a patient received a total laryngeal resection and a resection of 8 cm upper and middle trachea, which was replaced by a 6 cm long trachea of another donor. The donor trachea was dipped first in preservation liquid A for sterilization for 24 hours, then in preservation liquid B for over 48 hours for destructing MHC. Pedunculated greater omentum and pedunculated greater pectoral musculus supplied the blood for the donor trachea. One side of the donor was anastomosed with the lower trachea, and the other with the neck skin.

RESULTS

The patient survived 300 days after operation. The auto tracheal membrane covered the donor surface; auto- and xeno trachea was well anastomose. The new trachea grew very well.

CONCLUSION

Trachea transplantation is possible the best method to treat long tracheal disease if the transplantable trachea is less 5 cm.

Estradiol potentiates antiarrhythmic and antioxidative effects of intermittent hypoxic rat heart

AIM

To study the effects of estradiol (Est) on antiarrhythmic and antioxidative effects of intermittent hypoxia in rat heart.

METHODS

Ligating and loosening the coronary artery of rat to induce ischemic and reperfusion arrhythmias, using arrhythmia score (AS) to evaluate the arrhythmias, measuring the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in myocardium.

RESULTS

AS of arrhythmia induced by ischemia and reperfusion in intermittent hypoxia 28-d group (IH28) and in intermittent hypoxia with Est group (IH14-Est) are lower than that in control group (CON), respectively. AS of ischemic arrhythmia but not reperfusion arrhythmia in Est treated group (ESTG) was lower than that in CON. No significant difference in AS of ischemia and reperfusion existed among CON, vehicle group (VEH), and intermittent hypoxia 14-d group (IH14). The activity of SOD was higher and the content of MDA was lower in IH28 and in IH14-Est compared with that in CON. No significant difference of the activity of SOD and the content of MDA existed among CON, VEH, IH14, and ESTG.

CONCLUSION

Est potentiated the antiarrhythmic and antioxidative effects of intermittent hypoxia on rat heart.

[Proinflammatory cytokine stimulated NF-kappa B activation and the effect of dexamethasone in the human airway epithelial cells]

OBJECTIVE

To observe the expression of NF-kappa B activation and the effect of dexamethasone on the NF-kappa B activity in the human airway epithelial cell line 16HBE after TNF-alpha stimulation.

METHODS

After 16HBE was treated with different concentration of TNF-alpha(10 U/ml, 100 U/ml, 1,000 U/ml) and dexamethasone (100 nmol/L), total RNA and cellular, nuclear protein were extracted at 1 hour, 2 hour, 4 hour, respectively. RT-PCR and electrophoresis mobility shift assay(EMSA) were used to detect the expression of IL-8 mRNA and NF-kappa B activation.

RESULTS

The activity of NF-kappa B activation became stronger at 1 hour in the TNF-alpha stimulated group than the control, peaked at 2 hours and then decreased at 4 hours. Supershift assay confirmed that both p50 and p65 were components of active NF-kappa B. At the same time, IL-8 mRNA expression was elevated at 4 hours. After dexamethasone treatment, the expression of NF-kappa B activation and IL-8 mRNA became lower.

CONCLUSIONS

It is suggested that activated NF-kappa B played a key role in the inflammatory process of respiratory diseases through regulating the expression of some important factors (cytokines). Glucocorticoid inhibited the activation of NF-kappa B and showed antiinflammatory effect.

Intermittent hypoxia exposure-induced heat-shock protein 70 expression increases resistance of rat heart to ischemic injury

AIM

To quantify the levels of HSP70 induced by different durations of intermittent (high altitude) hypoxia and to correlate them with the degree of protection of the rat heart from ischemic injury.

METHODS

Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the level of HSP70 mRNA expression in rat myocardium. Ischemia/reperfusion injury was presented as severity of arrhythmias induced by occlusion and reperfusion of the left anterior descending coronary artery of rat heart.

RESULTS

The level of HSP70 mRNA expression increased progressively along with the duration of intermittent hypoxia training. It was 2.6, 3.6, and 3.8 folds after 14-, 28-, and 42-d exposures compared to that of normoxia. The tolerance of rat heart to ischemia/reperfusion injury increased with hypoxia pretreatment. Such an effect was significant after rat were exposed to a 28-d intermittent hypoxia (IH). The scores for ischemia and reperfusion inducing arrhythmia for 28- and 42-d IH were 1.2 +/- 0.5, 1.0 +/- 0.5 and 1.0 +/- 0.5, 0.9 +/- 0.5 (P < 0.01 compared with 4.0 +/- 0.7, 3.3 +/- 0.6 in normoxia rats). The overexpression of HSP70 and the increased tolerance to subsequent acute ischemia/reperfusion injury could last for 2 wk after the rats (subjected to 28 d IH) returned to normoxia. Furthermore, there was a reverse correlation between the amount of HSP70 induced and the arrhythmia occurrence (r = -0.98, -0.92 for ischemia and reperfusion induced arrhythmia, P < 0.01).

CONCLUSION

These results suggest that increased resistance of rat heart to ischemia/reperfusion injury after intermittent hypoxia exposure may be related to the amount of HSP70 induced.

[Antiarrhythmic and antioxidative effects of intermittent hypoxia exposure on rat myocardium]

The purpose of the study was to observe the effects of intermittent hypoxia exposure (IH) on the arrhythmia and antioxidation with ligation of coronary artery of rat heart together with measuring SOD (superoxide dismutase) and MDA (malondialdehyde) in myocardium. Comparison with continued hypoxia exposure was also made. The results obtained are as follows. (1) Arrhythmia scores of ischemic arrhythmia and reperfusion arrhythmia observed in the rats treated with IH 28-day (IH28) and 42-day (IH42), one week (IH28-1W) and two weeks (IH28-2W) after 28-day IH, as well as in those with continued hypoxia 28-day (CH28) and 42-day (CH42), were significantly lower than controls. (2) SOD in IH28, IH42, CH28, CH42, IH28-1W, IH28-2W and three weeks after 28-day IH were significantly higher than controls; MDA in IH14, IH28, IH42, CH28, CH42, IH28-1W and IH28-2W were significantly lower than controls. It is suggested that IH for 28 or 42 days has some definite antiarrhythmic effect against ischemia and reperfusion, which was related to the strength of antioxidation in myocardium. The antiarrhythmic effects occurred gradually after 14 days IH and persisted for about two weeks after 28 days IH.

Inhibitory effect of 1-(2, 6-dimethylphenoxy)-2-(3, 4-dimethoxyphenyl-ethylamino) propane hydrochloride on inward rectifier and delayed rectifier K+ currents in guinea pig ventricular myocytes

AIM

To study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenyl-ethylamino) propane hydrochloride (DDPH) on action potential (AP), inward rectifier K+ current (IK1), and delayed rectifier K+ current (IK) in isolated guinea pig ventricular myocytes.

METHODS

Whole cell patch-clamp recording techniques.

RESULTS

DDPH 0.1-100 mumol.L-1 decreased 50% duration of action potential (APD50) concentration-dependently. APD50 was shortened from (493 +/- 58) to (262 +/- 38) ms (n = 7 cells from 5 guinea pigs, P < 0.01) by DDPH 10 mumol.L-1. However, 90% duration of action potential (APD90) was increased by DDPH (> 1 mumol.L-1). At high concentration (> 10 mumol.L-1) DDPH decreased resting membrane potential (RP) and amplitude of action potential (APA). DDPH inhibited tail current of IK (IK.tail) concentration-dependently, 46% at 10 mumol.L-1 and 78% at 100 mumol.L-1. EC50 for DDPH inhibiting IK was 13.3 (11.6-16.7) mumol.L-1. DDPH also blocked IK1. DDPH at high concentration (> 10 mumol.L-1) shifted the reverse potential of IK1 positively. All the effects of DDPH were reversible after washout.

CONCLUSION

DDPH blocked both IK1 and IK current in guinea pig ventricular myocytes.

Volume- and calcium-activated chloride channels in human umbilical vein endothelial cells

AIM

To characterize the properties of chloride currents and its modulation in human umbilical vein endothelial cells (HUVEC).

METHODS

Using whole-cell patch-clamp recording techniques.

RESULTS

Exposure of HUVEC to 13.5% and 27% hypotonic solution (HTS) induced a current ICl, vol. This current was correlated with the changes in cell volume and showed a modest outward rectification. It was slowly inactivated at positive potential (> 50 mV), and it was time- and voltage-independent in kinetics. The current densities (pA/pF) were 20 +/- 3 (13.5% HTS) and 58 +/- 4 (27% HTS, n = 7), respectively at +100 mV test potential. Applying GTP gamma s (300 mumol.L-1) elicited a current similar to ICl, vol, while cAMP (0.5 mmol.L-1) had no effect on the current. Increase in [Ca2+]i, either by directly loading cells with high concentration of Ca2+ (CaCl2), or by perfusing vasoactive agonist ATP (10 mumol.L-1), activated ICl, Ca. The current density was only (23 +/- 5) pA/pF (n = 8 cells). Such current was slowly activated at positive potential, inactivated quickly at negative potential, and showed strong outward rectification. Both currents were inhibited by DIDS and verapamil. Challenging a cell with elevated [Ca2+]i and HTS activated ICl, vol on the top of ICl, Ca in the same cell, suggested co-existence of these two currents and that they were modulated by different ways. cAMP-regulated chloride channel and ClC (chloride channel family) channel were absent.

CONCLUSION

HUVEC express two kinds of chloride channels, ICl, vol activated by change in cell volume and ICl, Ca by elevation of [Ca2+]i, respectively.

[Modification of cochlear active micromechanism by auditory cortex]

OBJECTIVE

To investigate the modification of active micromechanism of outer hair cells by auditory cortex.

METHODS

1. Effects of selective attention on distortion product otoacoustic emissions (DPOAE) were analyzed in 9 human subjects with normal hearing. Visual tasks, two letters, O and Q, were alternatively displayed on a computer screen. Letter Q was target stimulus flashing randomly (probability was 20%), and letter O was non-target stimulus occurring regularly (probability was 80%). 2. In 13 guinea pigs, DPOAEs were measured before and after decerebration.

RESULTS

1. Visual tasks suppressed DPOAE significantly in both 1 kHz and 2 kHz (P < 0.05). 2. DPOAE reduced significantly in decerebrated guinea pigs.

CONCLUSION

The study further demonstrates that the efferents from the auditory cortex do innervate the cochlea, and the efferent pathway passes from the auditory cortex, the super olive complex to the cochlea. Through this pathway the auditory cortex modulates the cochlear active micromechanism. The underlying mechanism was discussed.

Modulation by muscarinic receptor antagonists on negative chronotropic effects of tetrandrine

AIM

To investigate the influence of selective antagonist for muscarinic (M) receptor subtype on tetrandrine (Tet) reducing heart rate, inhibiting sinoatrial node (SAN) function, and its ionic mechanism.

METHODS

Effects of reducing heart rate of Tet were maintained in isolated right atrium and pithed rats. Modification on action potentials (AP) of SAN cells and L-type calcium current (ICa-L) by Tet were recorded by means of standard microelectrode and patch-clamp whole cell recording techniques.

RESULTS

Tet inhibited spontaneous beating rate of isolated right atrium (EC50, 23.7 mumol.L-1) and reduced heart rates in pithed rats in a concentration-dependent manner (EC50, 18.6 mg.kg-1). Automaticity of SAN was inhibited by Tet. AP upstroke velocity (Vmax), spontaneous depolarization rates in phase 4 (SP4) were decreased and sinus cycle length (SCL) was prolonged when treated with Tet. Tet (30 mumol.L-1) caused a reduction in peak value of ICa-L from (1275 +/- 190) pA to (498 +/- 94) pA in isolated single cardiomyocyte. Atropine and AF-DX 116 (M2 subtype selective antagonist) could attenuate such effects of Tet in a competitive mode.

CONCLUSION

Negative chronotropic effects of Tet are due to its inhibition of ICa-L. Modification on ICa-L is the major mechanism of M receptor modulating Tet effects.

[Diagnostic significance of transiently evoked otoacoustic emissions in meniere's disease]

OBJECTIVE

To judge the diagnostic significance of TEOAE by glycerol test in Meniere's disease.

METHOD

TEOAE were recorded from all testing ears with or without Meniere's disease.

RESULT

The wave reproducibility, amplitude of response, band reproducibility, band SNR in ears of affected ears with meniere's disease after administration of glycerol were increased, about which the parameters of affected ears in positive glycerol test were obviously higher than that in negative glycerol test. All parameters in normal ears with Meniere's disease increased too, and there have the changes of main frequency.

CONCLUSION

TEOAE records of glycol test may be more sensitive and more simple than pure tone audiometry in diagnosing meniere's disease, and should be used more extensively.

[Characteristics of outward potassium currents of outer hair cell isolated from the guinea pig cochlea]

OBJECTIVE

To study the normal values and characteristics of potassium currents (Ik) of outer hair cell (OHC) isolated from the guinea pig cochlea.

METHOD

With the patch-clamp whole cell recording technique and several supplementary methods, the Ik potassium tail current (Iktail) and reverse potential were recorded under the conditions of the various intra and extracellular solutions and various command voltage stimuli.

RESULT

Ik possessed evident voltage and time-dependence. The peak current appeared within 20 ms. The average activated potential was approximately -32.7 mV. Ik increased fastestly and greatestly in the voltage range from the activating voltage to 0 mV, and it approached saturation approximately at 40 mV. In normal status, no distinct "rundown phenomenon" of Ik appeared. When 10 mmol/L KCl was put in extracellular solution, Ik would increased. Nevertheless, when K+ was substituted by Cs+ in the intracellular solution, Ik would disappear. The reversal potential, -64.0 mV in average approximately, could be measured by means of Iktail. Furthermore, by means of slope command voltage stimuli, the processes of Ik activation, increment or decrement and saturation could be observed.

CONCLUSION

As showing by the above described features, Ik possessed the characteristics of both an inward rectifier and rapid element of a delay rectifier, which would play important role in frequency tuning, mechanic-electrical transduction, maintenance of resting potential and excitement in OHC.

Comparison of the capacity of beta-cyclodextrin derivatives and cyclophanes to shuttle cholesterol between cells and serum lipoproteins

Previous studies from this laboratory have demonstrated that low concentrations of cyclodextrins (<1.0 mm), when added to serum, act catalytically as cholesterol shuttles to accelerate the exchange of free cholesterol between cells and serum lipoproteins. As cholesterol shuttles, cyclodextrins have the potential to serve as pharmacological agents for modifying cholesterol metabolism. In the present study, we have quantitated the cholesterol-shuttling capacity of a series of newly synthesized beta-cyclodextrin derivatives (betaCDs), with varying structure, and two double-decker cyclophanes. The general protocol is as follows. [(3)H]cholesterol-labeled CHOK1 cells are incubated for 2 h with the test compounds alone or together with 5% human serum, and efflux of the cellular [(3)H]cholesterol is measured. As methyl beta-cyclodextrin (MbetaCD) served as the basis for comparison, initial experiments were conducted that demonstrated there was a dose-dependent stimulation of cell cholesterol efflux as the concentration of MbetaCD increased, with an EC(50) that was calculated to be 0.05 mm. To determine the cholesterol-shuttling capacity of the newly synthesized compounds, cell cholesterol efflux is measured when the compounds are present alone, at a concentration of 0.05 mm, or together with 5% human serum. Our results demonstrate that the double-decker cyclophanes are the most efficient cholesterol shuttles. Under our experimental conditions, methyl beta-cyclodextrin (MbetaCD) approximately doubles the efflux of cell cholesterol to serum, whereas one of the double-decker cyclophanes produces a 4-fold stimulation in efflux. Four of the beta-cyclodextrin derivatives (betaCDs) display shuttling ability similar to that of MbetaCD. Furthermore, there does not appear to be a structural pattern among the other betaCDs which could explain their shuttling capacity.

[Effects of sodium salicylate on outward potassium current, resting potential and membrane electric capacitance of the outer hair cell isolated from guinea pig cochlea]

OBJECTIVES

To study effects of sodium salicylate on the outward potassium current (IK), resting potential (RP) and membrane electric capacitance (MEC) of outer hair cells isolated from guinea pig cochleas and the cytoelectrophysiological mechanisms of effects of sodium salicylate on functions of hair cells.

METHODS

Using the patch-clamp whole cell recording technique, IK, RP and MEC were measured before and after the administration of sodium salicylate at concentration of 0.1 or 1.0 mmol/L. The effects of sodium salicylate on IK, RP and MEC were observed.

RESULTS

The effects of sodium salicylate on IK had time- and dosage-effect relations, of which the former mean IK increasing and then decreasing after administration, the later meant that the effects of sodium salicylate being much more dominant during either increasing or decreasing IK in higher concentration than in lower concentration. The mean RP was approximately--60 mV and the mean MEC was approximately 39 pF. Sodium salicylate could decrease RP and MEC, which possessed a dosage-effect relation, that is, the effect was stronger in higher concentration than in lower concentration, and there was no clear evidence for time-effect relation.

CONCLUSIONS

The sodium salicylate might affect the K+ conduction at the lateral membrane and internal and external distribution of K+ in the outer hair cell. Sodium salicylate might affect the excitability and mechanical activity of the outer hair cell by means of affecting IK, RP and MEC, which might be one of the cochlear mechanisms of the effects of sodium salicylate on the functions of hair cells.

[Effect of ear-canal air pressure variation on tempanometry using a sweep-frequency probe tone]

OBJECTIVE

By observing the effect of ear-canal pressure variation (ECPV) on tempanometry using a sweep-frequency probe tone, the roles of sweep-frequency tempanograms changes were studied.

METHOD

Tympanograms using a sweep-frequence probe tone were measured for 60 ears of 30 subjects at ECPV by admittance (Y), susceptance (B), conductance (G) with GSI33 middle ear analyzer.

RESULT

There was not obviously difference about phase angle and resonance frequency among 3 measured conditions (P > 0.05); Resonance frequency became higher with higher positive pressure and lower with lower negative pressure in ear-canal; delta Y, delta G got lower with higher positive and lower negative pressure at resonance frequency; delta B is about 0 mmhos and almost didn't change with ECPV; phase angle decreased with higher positive or lower negative pressure. delta Y, delta G and delta phi were the highest at the peak pressure.

CONCLUSION

The higher the ear-canal positive pressure or the lower the negative pressure is, the higher the compliance and the lower the mass of middle ear is comparatively. The rub of middle ear is the lowest at normal peak pressure.

[Analysis of measured results of transient-evoked otoacoustic emissions]

OBJECTIVE

In order to provide grounds for clinical diagnosis, the normal sensitive parameters of the transient evoked otoacoustic emissions (TEOAE) in normal ears were studied.

METHOD

60 ears with normal hearing subjects using ILO-88 otodynamic analyzer system were measured, the click stimuli level is 80 dB SPL and the stimuli pattern used non-linear model.

RESULT

Analysis of the normal values of the stability, A-B difference, response amplitude, wave reproducibility, band reproducibility and band SNR, dominant frequencies were obtained.

CONCLUSION

The findings from comprehensive analysis of spectrum, response amplitude and reproducibility can be used as main sensitive parameters to evaluated whether or not of normal-hearing.

Trinucleotide CGG repeat in the FMR1 gene in Chinese mentally retarded patients

The fragile X syndrome of mental retardation is related to the number of trinucleotide CGG repeats at the 5'-untranslated region of the FMR1 gene located on the X-chromosome. We have studied X-chromosomes from 649 unaffected Chinese subjects and 324 patients with mild mental retardation. All study subjects were unrelated. The CGG repeat number was analysed by electrophoresis of a polymerase chain reaction followed by gel transfer and hybridisation with a 32P-labeled (CCG)5 probe. The DNA samples having detectable CGG expansion were further analysed by Southern blot analysis with probe StB12.3 after restriction digestion by EcoR I and Eag I. For the unaffected Chinese subjects, a different distribution pattern of CGG allele size from Caucasians was observed. It was a bimodal pattern and the CGG repeat number ranged from 19 to 54. The most common CGG repeat allele was 29 compared with 30 in Caucasians. The second mode appeared at 36 repeats. There was mild statistical difference in the repeat patterns between the mentally retarded patients and unaffected subjects, although the essential features were similar. Among the mentally retarded patients, one male had an unmethylated full mutation and one female had a full mutation. The fragile X prevalence was 0.6%, which is lower than two previous studies in Chinese mentally retarded patients utilising cytogenetic analysis. Our results indicate that a large-scale screening program would be worthwhile to determine the prevalence of the fragile X syndrome in the Chinese population.

Late infantile neuronal ceroid lipofuscinosis is due to splicing mutations in the CLN2 gene

Late infantile neuronal ceroid lipofuscinosis, LINCL, is one of the most common pediatric neurodegenerative disorders. It is caused by mutations in the CLN2 gene, which encodes a lysosomal pepstatin-insensitive peptidase (LPIP). We have identified a novel mutation, T523-1G --> A, by molecular analyses of three unrelated LINCL cases. The mutation was found to affect a 3' intronic splicing acceptor site, resulting in an aberrant mRNA with an insertion of 146 bp of intronic sequence. This causes a frame shift, produces a nonfunctional truncated protein, and results in LINCL.

Frequency of the fragile X syndrome in Chinese mentally retarded populations is similar to that in Caucasians

Fragile X syndrome is recognized as the most common inherited cause of mental retardation in western countries. The prevalence of the fragile X syndrome in Asian populations is uncertain. We report a multi-institutional collaborative study of molecular screening for the fragile X syndrome from 1,127 Chinese mentally retarded (MR) individuals. We found that 2.8% of the Chinese MR population screened by DNA analysis had the fragile X full mutation. Our screening indicated that the fragile X syndrome prevalence was very close to that of Caucasian subjects. In addition, we found that 62.5% of fragile X chromosomes had a single haplotype for DXS548-FRAXAC1 (21-18 repeats) which was present in only 9.7% of controls. This unique distribution of microsatellite markers flanking the FMR1 CGG repeats suggests that the fragile X syndrome in Chinese populations, as in the Caucasian, may also be derived from founder chromosomes.

Possible founder effects for FRAXE alleles

To determine if FRAXE alleles may have haplotype associations with nearby microsatellites, we analyzed 149 unrelated control Caucasian X chromosomes for FRAXE GCC alleles along with five nearby microsatellites. The microsatellites included three that are new; GT25, CA4, and CA5 located approximately 24, approximately 48, and approximately 50 kb proximal to the FRAXE GCC repeat, and two that were identified previously: DXS8091 and DXS1691, located approximately 90 and approximately 5 kb distal. No significant correlations between haplotypes for the proximal microsatellites were found. Significant correlations of FRAXE GCC repeats and distal microsatellite allele sizes, DXS8091 (r = 0.24) and DXS1691 (r = -0.40), were found. One haplotype, 18-19 of DXS8091-DXS1691, was present on 57% of chromosomes with > or =22 FRAXE repeats but present on only 10% with <22 repeats. We conclude that this distal haplotype association likely reflects a FRAXE allele founder effect. The lack of association or founder effects seen for the three newly identified proximal markers, located within 50 kb of FRAXE GCC, may reflect an unusually high rate of mutation for these microsatellites or a higher rate of recombination in the proximal region.