Biomedical subjects

Yuan Li

Publications and source records attributed to Yuan Li.

At least 55 records · Page 3Linked to original sources

PubMed2006

Glucocorticoid receptor subunit gene expression in thyroid gland and adenomas.

The present study was undertaken to investigate whether the glucocorticoid receptor -alpha (GR-alpha) and -beta (GR-beta) mRNA may be expressed in thyroid gland. Ten normal thyroid gland and 14 follicular adenomas were studied using a real-time fluorescent quantitative RT-PCR (FQ-RT-PCR) method. The results demonstrated that there was a lower expression of GR-alpha mRNA (x10(6) GR-alpha cDNA copies/microg total RNA) in thyroid adenoma (1.27+/-0.26) than that in normal thyroid gland (3.53+/-1.22) (p < 0.001). The expression of GR-beta mRNA was lower in all the thyroid tissues. Of note, there was a significant difference in GR-beta mRNA expression (x10(4) GR-beta cDNA copies/microg total RNA) between thyroid adenoma (80.8+/-13.9) and thyroid gland (1.78+/-0.59) (p < 0.001). The GR-alpha/GR-beta ratios in thyroid adenoma and normal thyroid gland were 1.67+/-0.68 and 207.57+/-84.41 respectively (p < 0.001). These results revealed, for the first time, that both GR-alpha and GR-beta mRNA expression were detectable in both thyroid gland and adenomas tissues. We therefore conclude that down-regulation of GR-alpha and up-regulation of GR-beta mRNA expression may play an important role in the thyroid adenomas.

Adenoma↗

PubMed2006

Sleep architecture in children with adenoidal hypertrophy.

AIM: Adenoidal hypertrophy (AH) in children is associated with obstructive manifestations like mouth breathing, snoring. Unfortunately, little is known regarding sleep architecture of AH in children. The purpose of this study was therefore undertaken to investigate the polysomnographic variables in children with AH. METHOD: 47 children with AH and 11 controls underwent nocturnal polysomnography. Sleep was scored manually according to the standard set by Rechtschaffen. RESULTS: In AH, stage 1 sleep percentage and rapid eye movement (REM) latency were increased significantly, while the sleep percentage of stage 2 and REM was decreased remarkably compared with that of controls. Arousal index in AH was much more higher than that in controls. Arousal index in REM sleep was higher than that in non-rapid eye movement (NREM) sleep in AH, but the number of arousals in REM sleep was lower than that in NREM sleep. Hypopnea events were the most common type of respiratory events, followed by obstructive events in AH and controls. Apnea/hypopnea index in AH was higher in comparison to controls. No significant difference was found between the children with AH and controls in SaO(2) nadir (%) and base mean SaO(2) (%). Apnea/hypopnea index was related to hypopnea arousal in REM sleep and hypoxemia arousal in NREM sleep. CONCLUSION: AH is predominantly characterised by a hypopnea with little obstruction in children. Our results clearly and for the first time demonstrated that sleep architecture was abnormal in children with AH. We therefore speculate that hypopnea arousal in REM sleep and hypoxemia arousal in NREM sleep may play an important role in the course of respiratory disturbance.

Adenoids↗

PubMed2006

Chronic prostatitis during puberty.

OBJECTIVE: To investigate the features of chronic prostatitis (CP) during puberty and the effects of biofeedback on young males with this disease. PATIENTS AND METHODS: In all, 40 patients were divided into two groups; group 1 included 25 pubertal patients with CP (mean age 16.5 years, sd 1.1) and group 2 was a control group including 15 patients (mean age 16.2 years, sd 1.2) with a normal lower urinary tract. National Institute of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) scores (three parts) were assessed individually in both groups. Expressed prostatic secretions and urine samples after prostate massage from group 1 were cultured to determine whether patients were infected with bacteria, and group 1 was categorized into various NIH types. Each patients in the two groups underwent urodynamics and group 1 were treated with biofeedback. RESULTS: In group 1, there were one, three and 21 patients with type II, IIIA and IIIB prostatitis. The incidence of staccato voiding and detrusor-sphincter dyssynergia (DSD), and the maximum urinary flow rate (Qmax), postvoid residual urine volume (PVR), maximum detrusor pressure (Pdetmax) and maximum urethral closure pressure (MUCP) between the groups were significantly different (P < 0.05). The total NIH-CPSI scores and all the subdomains between the groups before biofeedback were significantly different (P < 0.001). In group 1 the difference in NIH-CPSI scores and Qmax before and after biofeedback was significant (P < 0.05). CONCLUSIONS: The main type of CP during puberty is IIIB; the dominating symptom is a voiding disorder. The impact on life and psychological effects are substantial. Pubertal boys with CP have pelvic floor dysfunction and several abnormal urodynamic values, i.e. staccato voiding, DSD, decreasing Qmax, and increasing Pdetmax and MUCP. The effect of biofeedback strategies for treating pubertal CP is satisfactory.

Adolescent↗

PubMed2006

Vascular endothelial growth factor-C expression in bladder transitional cell cancer and its relationship to lymph node metastasis.

OBJECTIVE: To elucidate the role of vascular endothelial growth factor-C (VEGF-C) in bladder transitional cell carcinoma (TCC), examining VEGF-C expression in bladder TCC tissue and the association of VEGF-C with clinicopathological features, as the expression of VEGF-C in several carcinomas is significantly associated with angiogenesis, lymphangiogenesis and regional lymph node metastasis, but there are few reports of VEGF-C expression in bladder TCC. PATIENTS AND METHODS: The study included 45 patients with bladder TCC; VEGF-C expression was assessed by immunohistochemistry and the association between VEGF-C expression and angiogenesis, as evaluated by microvessel density (MVD), was examined. RESULTS: There was VEGF-C expression in the cytoplasm of tumour cells, but very little in the normal transitional epithelium. VEGF-C expression was significantly associated with tumour size, pathological T stage, pathological grade, lymphatic-venous involvement and pelvic lymph node metastasis (all P < 0.05). Multivariate analysis showed that VEGF-C expression was an exclusive independent factor influencing pelvic lymph node metastasis. Moreover, the patients with high VEGF-C expression had a markedly poorer prognosis than those with no or low VEGF-C expression (P = 0.014). A multivariate analysis based on the Cox proportional hazard model showed that lymph node metastasis was only an independent prognostic factor in the multivariate analysis using the Cox regression model (P = 0.010). CONCLUSION: The present study provides evidence supporting the involvement of VEGF-C expression in the promotion of lymph node metastasis in bladder TCC. Examination of VEGF-C expression in biopsy specimens might be beneficial in predicting pelvic lymph node metastasis.

Adult↗

PubMed2006

Glandular odontogenic cyst in China: report of 12 cases and immunohistochemical study.

OBJECTIVE: The purpose of this study was to present 12 additional cases of glandular odontogenic cyst (GOC) in the Department of Oral Pathology, School of Stomatology, Wuhan University, People's Republic of China, and to investigate their immunohistochemical cytokeratins (CKs) expression in the epithelial components. METHODS: A total of 12 GOCs were reviewed clinically and radiographically, and immunohistologic CKs AE1, 7, 8/18, 10/13, 14, 16, 19 and 20 were performed by using a standard biotin-streptavidin immunoperoxidase technique on paraffin sections. RESULTS: The present series showed that eight occurred in males and four in females. The mean age was 37.6 years with a peak incidence occurring in the third decades (six of 12). Mandibles were more affected than maxillas (7:5), especially anterior mandible (four of seven). Radiographically, ratio multilocular to unilocular radiolucencies was 5:7 usually with well-defined borders. Histologically, cystic spaces were lined by non-keratinized stratified epithelia containing focal plaque-like or whirlpool-like thickenings; surface epithelial layer-containing eosinophilic cuboidal cells; mucous cells; and mucin pools of microcystic areas in the epithelium. Immunohistochemistry showed that epithelium of GOCs stained for CKs AE1, 7, 8/18, 10/13, 14 and 19 with slight changes in their patterns, and no reaction to CKs 16 and 20. CONCLUSIONS: Most clinical and histologic features in this study were analogous to those reported west population, although with slight difference between them. Histologically, the morphology of the epithelium strongly suggested an odontogenic origin, and CKs expression of GOC was similar to that of odontogenic epithelium, suggesting histochemically that GOC might be derived from odontogenic epithelium.

Adult↗

PubMed2006

Role of oxidative stress in the apoptosis of hepatocellular carcinoma induced by combination of arsenic trioxide and ascorbic acid.

AIM: The present study was designed to determine the possible pathway underlying the enhancement of apoptosis induced by the combined use of arsenic trioxide (As(2)O(3)) and ascorbic acid (AA). METHODS: The level of intracellular reactive oxygen species (ROS) was detected by means of flow cytometry analysis with an oxidation-sensitive fluorescent probe (6-carboxy-2',7' dichlorodihydrofluorescein diacetate) uploading. The activity of glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were detected by biochemical methods. The mitochondrial membrane potential was measured by flow cytometry analysis with rhodamine 123 staining. Bcl-2, Bax, and p17 subunit of caspase-3 were analyzed using the Western blot method. The apoptosis rate was determined by flow cytometry with annexin-V/propidium iodide staining. RESULTS: Compared with As(2)O(3) (2.0 micromol/L) treated alone, As(2)O(3) (2.0 micromol/L) in combination with AA (100 micromol/L) decreased intracellular GSH content from 101.30+/-5.76 to 81.91+/-3.12 mg/g protein, and increased ROS level from 127.61+/-5.12 to 152.60+/-5.88, which was represented by the 2, 7-dichlorofluorescein intensity. The loss of mitochondria membrane potential was increased from 1269.97+/-36.11 to 1540.52+/-52.63, which was presented by fluorescence intensity. The p17 subunit of caspase-3 expression was increased approximately 2-fold. However, SOD and GPx depletion and the ratio of Bcl-2 to Bax were equal to that of As2O3 treated alone (P>0.05). When the ROS scavenger, N-acetyl-L-cysteine, was added to As(2)O(3) and AA combined treatment group, the apoptosis rate decreased from 15.60 %+/-1.14% to 9.48%+/-0.67%, and the ROS level decreased from 152.60+/-5.88 to 102.77+/-10.25. CONCLUSION: AA potentiated As(2)O(3)-induced apoptosis through the oxidative pathway by increasing the ROS level. This may be the result of depleting intracellular GSH. It may influence the downstream cascade following ROS, including mitochondria depolarization and caspase-3 activation. However, SOD and GPx depletion and the ratio of Bcl-2 to Bax influenced by As(2)O(3) was not found to be potentiated by AA.

Acetylcysteine↗

PubMed2006

Removal of arginine 332 allows human TRIM5alpha to bind human immunodeficiency virus capsids and to restrict infection.

Human TRIM5alpha (TRIM5alpha(hu)) only modestly inhibits human immunodeficiency virus type 1 (HIV-1) and does not inhibit simian immunodeficiency virus (SIV(mac)). Alteration of arginine 332 in the TRIM5alpha(hu) B30.2 domain to proline, the residue found in rhesus monkey TRIM5alpha, has been shown to create a potent restricting factor for both HIV-1 and SIV(mac.) Here we demonstrate that the potentiation of HIV-1 inhibition results from the removal of a positively charged residue at position 332 of TRIM5alpha(hu.) The increase in restricting activity correlated with an increase in the ability of TRIM5alpha(hu) mutants lacking arginine 332 to bind HIV-1 capsid complexes. A change in the cyclophilin A-binding loop of the HIV-1 capsid decreased TRIM5alpha(hu) R332P binding and allowed escape from restriction. The ability of TRIM5alpha(hu) to restrict SIV(mac) could be disrupted by the presence of any charged residue at position 332. Thus, charged residues in the v1 region of the TRIM5alpha(hu) B30.2 domain can modulate capsid binding and restriction potency. Therapeutic strategies designed to neutralize arginine 332 of TRIM5alpha(hu) might potentiate the innate resistance of human cells to HIV-1 infection.

Anti-HIV Agents↗

PubMed2006

Functional replacement of the RING, B-box 2, and coiled-coil domains of tripartite motif 5alpha (TRIM5alpha) by heterologous TRIM domains.

Tripartite motif 5alpha (TRIM5alpha) restricts some retroviruses, including human immunodeficiency virus type 1 (HIV-1), from infecting the cells of particular species. TRIM5alpha is a member of the TRIM family of proteins, which contain RING, B-box, coiled-coil (CC), and, in some cases, B30.2(SPRY) domains. Here we investigated the abilities of domains from TRIM proteins (TRIM6, TRIM34, and TRIM21) that do not restrict HIV-1 infection to substitute for the domains of rhesus monkey TRIM5alpha (TRIM5alpha(rh)). The RING, B-box 2, and CC domains of the paralogous TRIM6 and TRIM34 proteins functionally replaced the corresponding TRIM5alpha(rh) domains, allowing HIV-1 restriction. By contrast, similar chimeras containing the components of TRIM21, a slightly more distant relative of TRIM5, did not restrict HIV-1 infection. The TRIM21 B-box 2 domain and its flanking linker regions contributed to the functional defectiveness of these chimeras. All of the chimeric proteins formed trimers. All of the chimeras that restricted HIV-1 infection bound the assembled HIV-1 capsid complexes. These results indicate that heterologous RING, B-box 2, and CC domains from related TRIM proteins can functionally substitute for TRIM5alpha(rh) domains.

Amino Acid Motifs↗

PubMed2006

G protein-linked cell signaling and cardiovascular functions in diabetes/hyperglycemia.

Vascular complications, including impaired contractility and increased cell proliferation, are the most common complications with diabetes. Chronic hyperglycemia seems to be an important contributing factor in this process. Various signaling pathways are implicated in diabetes/hyperglycemia-induced impaired vascular functions. Nonenzymatic glycation, enhanced production of diacylglycerol, increased activity of membranous protein kinase C (PKC), and increased oxidative stress have been proposed to explain the adverse effects of hyperglycemia on vascular smooth muscle cells. Hyperglycemia-induced stimulation of L-type Ca2+ channel via G protein-coupled adenylyl cyclase/cAMP and phospholipase C/PKC pathways also has been shown. In addition, hyperglycemia has been reported to decrease the availability of nitric oxide in humans, which may contribute to all the hemodynamic and physiological changes occurring in diabetes. G protein-adenylyl cyclase signaling that plays an important role in the regulation of cardiovascular functions also has been reported to be impaired in diabetes and under hyperglycemic conditions. In this review article, various G protein-linked cell signaling and functions in diabetes and hyperglycemia are discussed.

Adenylyl Cyclases↗

PubMed2006

Macrophage-specific expression of human lysosomal acid lipase corrects inflammation and pathogenic phenotypes in lal-/- mice.

Lysosomal acid lipase (LAL) hydrolyzes cholesteryl esters and triglycerides to generate free fatty acids and cholesterol in the cell. The downstream metabolites of these compounds serve as hormonal ligands for nuclear receptors and transcription factors. Genetic ablation of the lal gene in the mouse caused malformation of macrophages and inflammation-triggered multiple pathogenic phenotypes in multiple organs. To assess the relationship between macrophages and lal-/- pathogenic phenotypes, a macrophage-specific doxycycline-inducible transgenic system was generated to induce human LAL (hLAL) expression in the lal-/- genetic background under control of the 7.2-kb c-fms promoter/intron2 regulatory sequence. Doxycycline-induced hLAL expression in macrophages significantly ameliorated aberrant gene expression, inflammatory cell (neutrophil) influx, and pathogenesis in multiple organs. These studies strongly support that neutral lipid metabolism in macrophages contributes to organ inflammation and pathogenesis.

Animals↗

PubMed2006

Microcirculatory detection of Toll-like receptor 4 in rat pancreas and intestine.

This paper was aimed to detect Toll-like receptor 4 (TLR4) microcirculatory expression and localization in rat pancreas and intestine. Acute pancreatitis (AP) was induced by twice injections of cerulein (20 mug in total) and acute necrotizing pancreatitis (ANP) was induced by intraductal injection of 5% taurocholate (1 ml/kg.bw). Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were used to detect and localize TLR4 in the pancreas and intestine. Results showed that RT-PCR of RNA isolated from pancreatic and intestinal tissue yielded the predicted amplicon for TLR4; IHC analysis localized TLR4 expression to the endothelium of pancreatic arteriole, venule, acinar capillary network and sinusoidal capillary of endocrine islet; TLR4 expression in intestine was principally in the microvascular endothelium and leucocytes within the mucosa lamina propria. TLR4 staining in intestine was more intense in taurocholate-induced pancreatitis (TIP) than that in cerulein-induced pancreatitis (CIP). In conclusion, TLR4 could be detected in the pancreatic and intestinal microcirculation, suggesting TLR4 involved in the microcirculatory impairment in AP; the more intense intestinal TLR4 expression in TIP suggests a potential risk for secondary infection.

Animals↗

PubMed2006

[Oocyte activation with calcium ionophore A23187 and puromycin on human oocytes that fail to fertilize after intracytoplasmic sperm injection].

OBJECTIVE: To investigate the effect of assisted oocyte activation with calcium ionophore A23187 and puromycin on human oocytes that fail to fertilize after intracytoplasmic sperm injection (ICSI). METHODS: All 113 discarded oocytes that showed no evidence of fertilization at 16 - 18 hours after in vitro maturation (IVM)-ICSI cycles and conventional ICSI were assigned to four groups according to the time after ICSI: IVM-ICSI 22-hour group (n = 33), IVM-ICSI 44-hour group (n = 18), ICSI 44-hour group (n = 37) and ICSI 68-hour group (n = 25). All unfertilized oocytes were exposed to calcium ionophore A23187 (5 micromol/L) for 5 minutes and subsequently incubated with puromycin (10 microg/ml) for 4 hours. After incubation, the oocytes were cultured in vitro for 3 - 5 days. The activation rate, proportion of oocytes that showed pronucleus formation and cleavage rate were calculated after activation. Sex chromosomal analysis was performed by dual color fluorescence in situ hybridization (FISH) on the embryos that displayed two pronuclei and a second polar body. RESULTS: The combination of calcium ionophore A23187 with puromycin could activate the unfertilized oocytes 22 - 68 hours after ICSI. Best results were achieved in IVM-ICSI 22-hour group, which elicited 88% (29/33) of activation rate, 62% (18/29) of cleavage rate and 28% (5/18) of 4-cell embryos. One embryo in this group developed to the morular stage. The activation rate and developmental potential of the activated embryos in IVM-ICSI 44-hour group, ICSI 44-hour group and ICSI 68-hour group decreased. FISH analysis showed 4 embryos with XX and 9 embryos with XY in 16 embryos. CONCLUSIONS: The combination of calcium ionophore A23187 with puromycin could effectively activate unfertilized oocytes 22 - 68 hours after ICSI. The cultured time of unfertilized oocytes after ICSI affects activation efficiency and developmental potential of the activated embryos. The activated zygotes that display two pronuclei and a second polar body can develop normally.

Calcimycin↗

PubMed2006

[Effects of enhanced UV-B radiation on physiological metabolism, DNA and protein of crops: a review].

Ozone depletion in stratosphere has led to the increase of solar UV-B radiation reaching to the earth surface, which would affect crops to various extents. This review dealt with the effects of enhanced UV-B radiation on the physiological metabolism, DNA damage and protein content of crops. Enhanced UV-B radiation could increase crops' flavonoid content but decrease their chlorophyll content and photosynthesis, induce gene change, and result in DNA damage and change of protein content.

Crops, Agricultural↗

PubMed2006

[Intraspecific differences in physiological responses of different wheat cultivars to enhanced UV-B radiation].

In this paper, field studies were conducted to determine the potential of alterations in physiology, and the intraspecific differences in sensitivity of 10 wheat (Triticum aestivum) cultivars to enhanced UV-B radiation. The supplemental UV-B radiation was 5.00 kJ x m(-2), simulating a depletion of 20% stratospheric ozone in Kunming area. The results showed that six of 10 tested wheat cultivars showed significant changes in total chlorophyll content, among which, chlorophyll a was strongly reduced, but chlorophyll b was reduced to a lesser extent, leading to a decrease in chlorophyll a/b ratio. The effects of UV-B on MDA and flavonoid contents also showed intraspecific difference. The MDA content of 5 cultivars was significant increased, while that of 2 cultivars was decreased. Four cultivars had significantly increased flavonoid content, but the flavonoid content in 2 cultivars was significantly decreased. The changes of chlorophyll and flavonoid contents were significantly correlated with the content of MDA(r = -0.78, P < 0.01 and r = -0.75, P < 0.05 respectively). There was a correlation between flavonoid and anti-UV-B radiation of wheat.

Chlorophyll↗

PubMed2006

[Investigation of GR mRNA quantu expression in chronic sinusitis and nasal polyps].

OBJECTIVE: To detect the expression of the glucocorticoid receptor-alpha/beta (GR-alpha/beta) mRNA in nasal polyp and normal nasal mucosa and investigate the significance of receptor-alpha/beta in GC-insensitive and GC-sensitive patients. METHODS: The expression of GR-alpha/beta mRNA in 40 samples of nasal polyp and 30 normal nasal mucosa was examined by using Fluorescent quantitative PCR. RESULTS: Forty cases were screened from the 80 cases after follow-up, including 26 cases of GC-sensitive and 14 cases of GC-insensitive. the levels of GR-beta mRNA in group of GC-insensitive [(5.72 +/- 0.58) x 10(2) copy/microg] were significantly higher than that of GC-sensitive [(4.82 +/- 0.28) x 10(2) copy/microg, t = -6.65, P < 0.01] and normal nasal mucosa [(4.44 +/- 0.35) x 10(2) copy/microg, t = -9.19, P < 0.01]. There was difference between group of GC-insensitive and other two groups of GC-sensitive and normal nasal mucosa (P < 0.01). The ratio of GR-alpha/GR-beta showed significant difference between the group of GC-sensitive (829.42 +/- 67.36) and that of GC-insensitive (535.70 +/- 89. 00, t = 11.74, P < 0.01). CONCLUSIONS: The high expression of GR-beta mRNA and low expression of GR-alpha mRNA in nasal polyp show the status of "insensitive" in chronic sinusitis and nasal polyp. The GR-beta may play an important role in evaluating the effect of glucocorticoid in chronic sinusitis and nasal polyps.

Adult↗

PubMed2006

[Comparison of the outcome of intracytoplasmic single sperm injection between two motile sperm separation methods].

OBJECTIVE: To evaluate the efficiency of density gradient and improved swim-up methods for motile sperm isolation from fresh semen samples in intracytoplasmic sperm injection and embryo transfer (ICSI-ET) program, thus guiding the clinical application. METHODS: The fertilization rate, cleavage rate, high-quality embryo rate, clinical pregnancy rate, sperm abnormal rate and recovery rate of 42 cycles were studied prospectively. The cycles were divided into two groups with respect to the motile sperm isolation methods. RESULTS: No obvious difference was found in the fertilization rate, cleavage rate, high-quality embryo rate and clinical pregnancy rate between the two methods. The abnormal sperm rate induced by the improved swim-up method was significantly higher than that of the density gradient method (P < 0.01). For severe oligozoospermia, the recovery rate of motile sperm with density gradient was higher than that of improved swim-up (P < 0.01). CONCLUSION: In the ICSI-ET, there is no obvious difference in clinical pregnancy outcome between the two methods. The method of improved swim-up can be used for all patients but those with severe oligozoospermia.

Adult↗

PubMed2006

[Gene rearrangement studies in Hashimoto's thyroiditis and primary lymphoma of thyroid].

OBJECTIVE: To study the immunoglobulin gene rearrangement patterns in Hashimoto's thyroiditis (HT) and primary thyroid lymphoma (PTL), and to analyze the relationship between the two diseases. METHODS: Formalin-fixed and paraffin-embedded tissues of 11 cases of PTL and 38 cases of HT as well as their clinical data, were retrieved. The latter group was further subcategorized into classic HT and suspicious PTL. Gene rearrangement studies for immunoglobulin heavy chains and light chains were carried out by polymerase chain reaction (PCR) using VH, FR3A and FR3kappa primers. RESULTS: There was an increasing trend in immunoglobulin gene rearrangement rate for classic HT (10.7%), suspicious PTL (40.0%) and PTL (72.7%) groups. In general, a female predilection was observed. This sex predilection however was less obvious in the PTL group. There was no relationship between serum antibody (both thyroglobulin and thyroid peroxidase) titers and gene rearrangement patterns. CONCLUSIONS: HT and PTL show morphologic overlaps and may not be clearly distinguished on the basis of light microscopy alone. PCR-based immunoglobulin gene rearrangement study may be helpful in the detection of cases with early lymphomatous transformation of HT.

Female↗

PubMed2006

[The artifacts and test-retest reliability of multiple auditory steady-state response].

OBJECTIVE: To investigate the characteristics and clinical application of artifacts and the test-retest reliability of multiple auditory steady-state response (MASSR). METHOD: The authors tested a group of healthy young volunteers and a group of patients with sensory hearing loss with the MASSR by analysing the rate of false negative artifacts (FNA) and their distribution. The healthy young volunteers were retested with MASSR several days after the first test to investigated the test retest reliability of MASSR. Furthermore, three cases of healthy young volunteers were retested in the sleeping status to explore the stability of MASSR threshold and the influence of sleep. RESULT: (1) The FNA mainly distributed in low frequencies districts and the intensities were near threshold, no remarkable differences could be seen between the normal ears and the ear with sensory hearing loss. The FNA disappeared when the volunteers were asleep. (2) The test-retest variability was much higher in 0.5 kHz than in other frequencies. The variable range was 0 - 30 dB in 0.5 kHz, and there was test-retest reliability in 1.0-4.0 kHz. (3) The artificial response was present when using strong stimulus for the patients with profound hearing loss. When MASSR was recorded in awake condition, the FNA appeared. When using strong stimulus for the cases with profound hearing loss, the artificial response existed and the test-retest variabilities were large. The whole test duration was often much longer than the auditory brainstem response (ABR) and 40 Hz auditory evoked potential (40 Hz AEP). CONCLUSION: As an objective auditory evaluation method, MASSR scarcely has superior characteristics to ABR and 40 Hz AEP.

Adolescent↗