Quantitative assessments of retinal macular structure among rural-dwelling older adults in China: a population-based, cross-sectional, optical coherence tomography study.

OBJECTIVES: To quantitatively assess and compare retinal macular structures of rural-dwelling older adults in China using two different optical coherence tomography (OCT) scanners and to examine their associations with demographic, lifestyle, clinical and ocular factors. DESIGN, SETTING AND PARTICIPANTS: This population-based, cross-sectional study included 971 participants (age ≥60 years) derived from the Multimodal Interventions to Delay Dementia and Disability in Rural China study. We collected data on demographics, lifestyle factors, clinical conditions (eg, cardiovascular disease (CVD)) and ocular factors (eg, visual acuity and spherical equivalent). We used two models of spectral-domain OCT to measure macular parameters in nine Early Treatment Diabetic Retinopathy Study subfields. Data were analysed using the multiple general linear models. RESULTS: Spectralis OCT demonstrated higher macular thickness but a lower macular volume than Primus 200 OCT (p<0.05). Nasal quadrant of the inner and outer subfields was the thickest, followed by superior quadrant. Adjusting for multiple potential confounding variables, older age was significantly correlated with lower average inner and outer macular thicknesses and overall macular volume. Men had higher macular parameters than women. The presence of CVD was correlated with lower central macular thickness (ß=-6.83; 95% CI: -13.08 to -0.58; p=0.032). Middle school or above was associated with higher average inner macular thickness (ß=7.85; 95% CI: 1.14 to 14.55; p=0.022) and higher spherical equivalent was correlated with lower average inner macular thickness (ß=-1.78; 95% CI: -3.50 to -0.07; p=0.042). CONCLUSIONS: Macular thickness and volume assessed by Spectralis and Primus 200 OCT scanners differ. Older age and female sex are associated with lower macular thickness and volume. Macular parameters are associated with education, CVD and spherical equivalent. TRIAL REGISTERATION NUMBER: MIND-China study (ChiCTR1800017758).

Thyroid stimulating hormone correlates with triglyceride levels but is not associated with the severity of acute ischemic stroke in patients with euthyroidism: a cross-sectional study.

Background: Growing evidence suggests an association between thyroid stimulating hormone (TSH) and severity of acute ischemic stroke (AIS). However, few studies have ruled out the potential influences of abnormal thyroid hormones when assessing this association. This study aimed to investigate the association between TSH levels and the severity of AIS patients with euthyroidism, and to explore the potential mechanism of TSH on this disease by analyzing the correlation of TSH with lipid profiles. Methods: This retrospective study consisted of 345 patients with normal T3 and T4 levels admitted for first-ever cerebral ischemic stroke. Baseline data of participant were collecte. Laboratory data, including serum levels of TSH and lipid profiles were measured in our hospital's clinical laboratory on admission. Stroke severity was recorded using the National Institutes of Health Stroke Scale (NIHSS). Associations between TSH levels and disease severity were analyzed with logistic regression analysis. Correlations between TSH and lipid profiles were analyzed with Spearman's rank correlation analysis. Results: Among the 345 patients with AIS, the median age was 63 years (63±12 years), 106 patients (30.7%) were female, 237 (68.7%) patients were mild-severity and 108 (31.3%) patients were severity. Data analysis showed that higher serum TSH levels were associated with the mild severity of patients with AIS (P=0.042 in Kruskal-Wallis test, P=0.025 in logistic regression analysis, and P=0.044 in multiple logistic regression), but not in AIS patients with euthyroidism (P=0.078, P=0.337, respectively). Furthermore, TSH levels were correlated with triglycerides (TG) levels not only in total patients (r=0.135, P=0.012) but also in the patients with euthyroidism (r=0.133, P=0.018). Conclusions: TSH levels are associated with the severity of AIS patients, but not in patients with euthyroidism, predicting that stratified management of TSH may be beneficial in patients with AIS. Moreover, TSH levels are correlated with TG levels in patients with AIS.

Mild cognitive impairment among rural-dwelling older adults in China: A community-based study.

BACKGROUND: Epidemiological studies of mild cognitive impairment (MCI) and subtypes of MCI have rarely focused on rural residents in China. METHODS: This population-based study included 5068 participants (age ≥60 years) who were living in rural communities. We defined MCI, amnestic MCI (aMCI), and non-amnestic MCI (naMCI) following the Petersen's criteria that integrated neuropsychological assessments with in-person clinical evaluations. RESULTS: The overall prevalence of MCI, aMCI, and naMCI was 26.48%, 22.30%, and 4.18%, respectively. The prevalence of MCI increased with age. The adjusted odds ratio (OR) of MCI was 0.71 (95% confidence interval [CI] 0.61 to 0.82) for primary school (vs. illiteracy), 0.30 (0.24 to 0.39) for middle school or above, 1.35 (1.09 to 1.67) for being farmers, 0.65 (0.54 to 0.78) for alcohol consumption, 1.43 (1.20 to 1.70) for stroke history, and 1.14 (0.95 to 1.36) for any apolipoprotein E (APOE) ε4 allele (vs ε3/ε3). CONCLUSIONS: MCI affects over one-fourth of rural older adults in China. Overall MCI was associated with demographic factors, non-alcohol consumption, and stroke, but not with APOE genotype and cardiometabolic factors.

Serum adenosine deaminase activity and acute cerebral infarction: a retrospective case-control study based on 7913 participants.

BACKGROUND: Adenosine deaminase (ADA) is a key enzyme that catalyzes the deamination of adenosine into inosine, which eventually decomposes into uric acid (UA). A body of papers have reported that adenosine and UA are closely related to cerebrovascular events. However, the association between serum ADA activity and acute cerebral infarction (ACI) remains unclear. METHODS: 7913 subjects were enrolled, including 3968 ACI patients and 3945 controls, in this study. An automatic biochemistry analyzer was used to determine serum activity. RESULTS: Serum ADA activity was found that was significantly decreased in patients with ACI (10.10 ± 3.72 U/L) compared to those without ACI (11.07 ± 2.85 U/L, p < 0.001). After Logistic regression analysis, ADA concentrations were negatively correlated with ACI (OR = 1.161, 95% CI: 1.140-1.183, p < 0.001). Smoking and alcohol consumption decreased serum ADA concentrations in patients with ACI, whereas diabetes and hypertension had the opposite effect. CONCLUSIONS: Serum ADA concentrations in patients with ACI are markedly decreased, suggesting that the decreased ADA concentrations may be involved in the pathogenesis of ACI. We hypothesized that decreased ADA activity may be an adaptive mechanism to maintain adenosine levels and protect against ischemic brain injury.

LIGHT deficiency attenuates acute kidney disease development in an in vivo experimental renal ischemia and reperfusion injury model.

Ischemia-reperfusion (I/R), a leading risk factor of acute kidney injury (AKI), is associated with high mortality and risk of progression to chronic kidney disease. However, the molecular mechanism of I/R-AKI remains not fully understood, which hinders its efficient clinical treatment. In this study, we observed that LIGHT deficiency remarkably attenuated I/R-AKI, as evidenced by rescued renal function, ameliorated tubular cell apoptosis, and alleviated inflammatory responses. Consistently, blocking LIGHT signaling with its soluble receptor fusion proteins (HVEM-IgG-Fc or LTßR-IgG-Fc) improved I/R renal dysfunction. RNA-sequencing and corresponding results indicated that LIGHT promoted oxidative stress and inflammation triggered by ischemic injury. Moreover, LIGHT signaling augmented ischemic stress-induced mitochondrial dysfunction characterized by an imbalance in mitochondrial fission and fusion, decreased mtDNA copies, impaired mitophagy, and increased mitochondrial membrane potential (ΔΨm). Mechanistically, LIGHT promoted mitochondrial fission by enhancing Drp1 phosphorylation (Ser616) and its translocation to the mitochondria. In conclusion, these results suggest that LIGHT-HVEM/LTßR signaling is critical for the I/R-AKI pathogenesis and it is further confirmed to be related to the increase in I/R-induced oxidative stress and mitochondria dysfunction, which may be the underlying mechanism of LIGHT signaling-mediated I/R-AKI.

Clinical Features, Treatment, and Prognostic Factors in Neuronal Surface Antibody-Mediated Severe Autoimmune Encephalitis.

Objective: This study aimed to determine the clinical characteristics and evaluate the efficacy of immunotherapy and the long-term prognosis of severe autoimmune encephalitis (AE) in China. Methods: Clinical features, laboratory or radiological findings, and treatment outcomes of 60 severe patients with AE from January 1, 2014, to December 31, 2020, were collected. Continuous variables were compared using the t-test and the nonparametric Mann-Whitney U test, as appropriate. Univariate and multivariable logistic regression analyses were performed to assess the correlations between factors, treatment responses, and prognosis of severe AE. Results: The median age of symptom onset was 35 years. Tumors were identified in 23.3% of patients, and 36/60 (60%) patients responded to first-line immunotherapy. Second-line immunotherapy was implemented in 26/60 (43.3%) patients. A significant clinical benefit was observed in 19/26 (73.1%) patients treated with lower dosage rituximab; seven patients were still refractory and received bortezomib as an add-on therapy. During the last follow-up, 48/60 (80%) patients achieved good outcomes (mRS, 0-2), and 10 died. Seventeen patients experienced relapses. A high CD19+ B-cell count (OR, 1.197; 95% CI [1.043-1.496]; p = 0.041) and a lower neutrophil-to-lymphocyte ratio (NLR; OR, 0.686; 95% CI [0.472-0.884]; p = 0.015) predict the response to first-line treatment and good prognosis, respectively. Conclusions: Patients with severe AE were in critical condition at baseline but could be salvaged after effective rescue immunotherapy. A lower dosage of rituximab could be an optimal option for severe AE. CD19+ B-cell count and NLR may provide prognostic information for predicting treatment response and outcome of severe AE.

Health status and risk profiles for brain aging of rural-dwelling older adults: Data from the interdisciplinary baseline assessments in MIND-China.

Introduction: Multidomain intervention approaches have emerged as a potential strategy to reduce dementia risk. We sought to describe the baseline assessment approaches, health conditions, and risk profiles for brain aging of participants in the randomized controlled Multimodal INterventions to delay Dementia and disability in rural China (MIND-China). Methods: MIND-China engaged residents who were ≥60 years of age and living in rural communities in the western Shandong province. In March to September 2018, all participants underwent the core module assessments via face-to-face interviews, clinical examinations, neuropsychological testings, and laboratory tests. Specific modules of examination were performed for sub-samples, including brain magnetic resonance imaging scans, genetic and blood biochemical markers, actigraphy testing, cardiopulmonary coupling analysis for sleep quality and disturbances, audiometric testing, and optical coherence tomography examination. We performed descriptive analysis. Results: In total, 5765 participants (74.9% of all eligible residents) undertook the baseline assessments. The mean age was 70.9 years (standard deviation, 5.9), 57.2% were women, 40.6% were illiterate, and 88.3% were farmers. The overall prevalence of common chronic diseases was 67.2% for hypertension, 23.4% for dyslipidemia, 23.5% for heart disease, 14.4% for diabetes mellitus, and 5.4% for dementia. The prevalence rates of hypertension, diabetes mellitus, dyslipidemia, obesity, heart disease, depressive symptoms, and dementia were higher in women than in men (P < .05). Overall, 87.1% of the participants had at least two of the 15 chronic diseases (89.3% in women vs 84.2% in men, P < .001). Participants examined for the specific modules were younger, more likely to be women, and more educated than those not examined. Discussion: Comprehensive baseline assessments of participants in MIND-China provide extremely valuable data sources for interdisciplinary research into the complex relationships of aging, health, brain aging, and functional consequences among older adults living in the rural communities. Highlights: MIND-China is a multimodal intervention study among rural residents ≥60 years of age.At baseline, 5765 participants undertook the interdisciplinary assessments.The baseline assessments consisted of core module and specific modules.Specific modules included brain magnetic resonance imaging (MRI), blood biomarkers, ActiGraph, cardiopulmonary coupling (CPC), pure-tone audiometry (PTA), and optical coherence tomography (OCT).

MiRNA-190 exerts neuroprotective effects against ischemic stroke through Rho/Rho-kinase pathway.

Ischemic stroke is an urgent public health concern and one of the major causes of deaths and disabilities over the world. MicroRNA (miRNA) has become a key mediator of cerebral ischemia-reperfusion (I/R) injuries. However, whether miR-190 is involved in cerebral I/R-induced neuronal damage remains unknown. This study was to investigate the role of miR-190 in the brain I/R injury. We divided the rats into sham, I/R, control, and miR-190-mim (miR-190 mimics) groups. Quantitative real-time polymerase chain reaction (qRT-PCR), Nissl staining, flow cytometry, and western blot were conducted to examine the expression of miR-190 and cell apoptosis in different groups. The results showed that the expression of miR-190 was greatly decreased in rats suffering with I/R. Overexpression of miR-190 significantly reduced the increased neurological scores, brain water contents, infarct volumes, and neuronal apoptosis in rats suffering with I/R. In addition, we found that the expression of RhoA and Rho kinase was greatly elevated in rats suffering with I/R. Bioinformatics analysis indicated that Rho was a target of miR-190. Moreover, overexpression of miR-190 significantly downregulated the increased mRNA and protein expression of Rho/Rho kinase and cell apoptosis, while inhibition of miR-190 further upregulated the increased mRNA and protein expression of Rho/Rho kinase and cell apoptosis in rats suffering with I/R. Furthermore, knockdown of Rho significantly downregulated the increased mRNA and protein expression of Rho/Rho kinase and cell apoptosis, while these effects were inhibited by miR-190 inhibitors in rats suffering with I/R. These results indicate that miR-190 confers protection against brain I/R damage by modulating Rho/Rho-kinase signaling.

Association of KCNJ10 variants and the susceptibility to clinical epilepsy.

We first enrolled the available case-control studies to investigate the genetic association between three polymorphisms (rs1130183, rs1890532, and rs2486253) of KCNJ10 (the potassium voltage-gated channel subfamily J member 10) gene and the susceptibility towards clinical epilepsy. We utilized the meta-analysis, FPRP (false-positive report probability) test, and the TSA (trial sequential analysis) for the data pooling and the evaluation of statistical power. Totally, eight eligible articles were finally included. For KCNJ10 rs1130183, compared with population-based controls, a reduced epilepsy risk in cases was observed in models of allelic T vs. C, heterozygotic CT vs. CC, dominant CT + TT vs. CC, carrier T vs. C [all OR (odds ratio) <1, P < 0.05, Benjamini & Hochberg-adjusted P < 0.05, bonferroni-adjusted P < 0.05]. There were similar results in the subgroup analysis of "Caucasian". The positive conclusion was also statistically supported by the result of the FPRP test and TSA. Nevertheless, no statistically significant differences between epilepsy cases and negative controls were detected in any comparison of KCNJ101890532 and rs2486253. In summary, it is possible that the CT genotype of KCNJ10 rs1130183 is related to a reduced clinical epilepsy susceptibility, especially in Caucasians. However, more sample sizes are still required for a more robust conclusion in different populations, and more adjusted factors should be considered.

Complement component 3 prevents imiquimod-induced psoriatic skin inflammation by inhibiting apoptosis in mice.

Complement component 3 (C3), a pivotal molecule in the complement system, is an essential immune mediator in various diseases, including psoriasis. However, the mechanistic role of C3 in psoriasis pathology and development remains elusive. Here, we showed that C3 deficiency dramatically augmented imiquimod-induced psoriasis-like skin inflammation, characterized by greater epidermal hyperplasia, inflammatory cell infiltration, and inflammatory gene expression than those in wild-type counterparts. In addition, C3 deficiency promoted imiquimod-induced skin cell apoptosis and supported greater proportions of IFN-γ+ T cells in the inflamed tissues. Accordingly, C3 supplement in the C3 deficient mice reduced skin inflammation and cells apoptosis. Moreover, blocking apoptosis with Z-VAD-FMK, a broad caspase inhibitor, markedly attenuated imiquimod-induced psoriasis-like skin inflammation and IFN-γ+ T cell responses in C3-deficient mice. Collectively, our results suggest that C3 prevents imiquimod-induced psoriasis-like skin inflammation by inhibiting apoptosis.

The genetic effect of the ICAM1 (intercellular adhesion molecule 1) rs5498 polymorphism on the susceptibility towards multiple sclerosis.

In the present study, we included currently published evidence to comprehensively evaluate the influence of the rs5498 polymorphism within the ICAM1 (intercellular adhesion molecule 1) gene on the genetic risk of multiple sclerosis. STATA 12.0 software was utilized to carry out the heterogeneity assessment, association test, and Begg's test as well as the Egger's tests and sensitivity analyses. A total of 11 high-quality case-control studies were selected from the initially retrieved 2209 articles. The lack of high heterogeneity led to the use of a fixed-effect model in all genetic models. The results of the association test showed a reduced risk of multiple sclerosis in the allelic G vs A (Passociation = 0.036, OR = 0.91) and dominant AG+GG vs AA (Passociation = 0.042, OR = 0.85) but not in other genetic models (all Passociation > 0.05). In addition, the negative results were observed in further subgroup analyses based on ethnicity or Hardy-Weinberg equilibrium in all genetic models. Data from Begg's and Egger's tests further excluded the presence of remarkable publication bias, while sensitivity analysis data supported stable outcomes. Thus, we conclude that ICAM1 rs5498 may not be related to the risk of multiple sclerosis in Caucasian or Asian populations, which still merits further research.

Unique expression pattern of KIBRA in the enteric nervous system of APP/PS1 mice.

KIBRA has been recognized as a memory-related gene, which is abundant in the brain and kidney of mammals. However, the expression pattern of KIBRA in the "second brain"-enteric nervous system (ENS) is still unknown, especially in neurodegenerative disorders. In this study, we aimed to investigate the detailed expression pattern of KIBRA in the intestinal myenteric nerve plexus of APP/PS1 and wild type mice by whole mount staining technology. The deposition of Aß and increased levels of phosphorylated Tau (p-Tau) and total Tau (T-Tau) protein were observed in the intestinal myenteric nerve plexus of APP/PS1 mice. Interestingly, the amount of Tuj+ cells remained unchanged between these two groups. Compared to the control mice, the protein levels of KIBRA significantly increased in the jejunal myenteric plexus of APP/PS1 mice, and the proportion of KIBRA+ GABAergic neurons in both the jejunal myenteric nerve plexus and the cortex was much higher in the APP/PS1 mice. But there was no significant difference in the number of KIBRA+ cholinergic neurons and KIBRA+ nitrergic neurons between APP/PS1 and wild type mice. In summary, our study further confirmed that typical pathology features of Alzheimer's disease (AD) not only existed in the central nervous system but also in the ENS.

Role of stem cell factor in the regulation of ICC proliferation and detrusor contraction in rats with an underactive bladder.

Stem cell factor (SCF) is critical in regulating the proliferation, differentiation and function of the interstitial cells of Cajal (ICCs), which are closely associated with smooth muscle dysfunction. The present study aimed to examine the effect of SCF on ICC proliferation and detrusor contraction in rats with an underactive bladder. Sprague­Dawley rats were divided into four groups comprising control, control+SCF, detrusor underactivity (DU), and DU+SCF groups. The ICC count was determined using immunofluorescence; serum levels of SCF were determined using an enzyme­linked immunosorbent assay; mRNA and protein levels of c­kit and SCF in tissues were assessed using reverse transcription­quantitative polymerase chain reaction and western blot analyses, respectively. Detrusor contractility was determined using muscle strips, based on the contraction amplitude and frequency determined in each specimen. Significantly fewer ICCs were observed in the DU group, in addition to decreased expression levels of SCF and c­kit, compared with the control group. In addition, the detrusor contraction frequency and amplitude were markedly reduced. However, the administration of SCF significantly increased the number of ICCs, and the levels of SCF and c­kit in animals with DU, and resulted in markedly amplified detrusor contraction frequency and amplitude. Similarly, the number of ICCs and levels of SCF and c­kit were higher in the control+SCF group, compared with the control group. Overall, these findings suggested that exogenous SCF improved the organ dysfunction caused by reduced ICC number, providing a novel approach for organ repair.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Ureaplasma urealyticum infections using a novel isothermal simultaneous RNA amplification testing method in infertile males.

BACKGROUND: The purpose of this study was to evaluate the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Ureaplasma urealyticum infections in infertile men that consulted our outpatient departments using a novel simultaneous amplification testing (SAT) that is RNA-detection based. The possible impact of C. trachomatis, N. gonorrhoeae, M. genitalium and U. urealyticum infections on semen parameters was also noted in the present study. METHODS: A total of 2607 males that were diagnosed with infertility were included in this study. C. trachomatis, N. gonorrhoeae, M. genitalium and U. urealyticum infections were detected in the urine samples using SAT method. Related data, including semen parameters and age as well as C. trachomatis, N. gonorrhoeae, M. genitalium and U. urealyticum infections were collected and analyzed. RESULTS: A total of 51 and 1418 urine samples were found positive for M. genitalium RNA and U. urealyticum RNA, respectively, while the prevalence of C. trachomatis and N. gonorrhoeae was relatively lower. Men with positive M. genitalium RNA and U. urealyticum RNA had higher sperm DNA fragmentation index (DFI) while the comparisons of other semen parameters yielded nonsignificant results between the RNA positive and negative group. A multivariate linear regression analysis revealed that U. urealyticum and M. genitalium infections posed significant factors of DFI (adjusted R2 = 46.2%). CONCLUSIONS: Our study suggested a relative high prevalence of U. urealyticum and M. genitalium infection based on this novel SAT detection method. U. urealyticum and M. genitalium infection could possibly impair male fertility potential through promoting sperm DNA damage.

Triptolide Protects Against Ischemic Stroke in Rats.

Inflammatory response plays an important role in the pathogenesis of ischemic stroke and anti-inflammatory agents may provide a choice of treatment. Triptolide is reported to be anti-inflammatory. In this study, we investigated the effects of triptolide on cultured neuronal cell line in vitro and experimental ischemic stroke in vivo. Oxygen-glucose deprivation (OGD) and tumor necrosis factor-α (TNF-α) stimulated SH-SY5Y cells were incubated with triptolide. In vivo, rats were subjected to middle cerebral artery occlusion (MCAO) for 1 h, followed by reperfusion for 23 h. Results of this study showed that triptolide treatment reduced the OGD-induced cytotoxicity and apoptosis and blocked TNF-α-induced activation of NF-κB and p38MAPK in SH-SY5Y cells. Intraperitoneal injection of triptolide showed significant neuroprotective actions in stroke rats. Triptolide attenuated neurological deficit, brain infarct volume, and brain water content, and inhibited activation of NF-κB and p38MAPK. These data show that triptolide protects rats against ischemic cerebral injury via inhibiting NF-κB and p38MAPK signaling pathways.

[Study on the neurophysiologic of detrusor overactivity due to partial bladder outflow obstruction].

OBJECTIVE: To study the neurophysiologic of detrusor overactivity (DO) due to partial bladder outflow obstruction (PBOO). METHODS: Twenty four female Wistar rats with DO caused by PBOO were studied simultaneously with ten sham-operated rats. An electrophysiological multi-channel simultaneous recording system was used to record pelvic afferent fiber potentials as well as the pudendal nerve motor branch potentials, external urethral sphincter electromyogram (EUS EMG) and abdominal muscle EMG during filling cystometry. To test the effect of the unstable contraction in DO rats after the decentralization of the central nervous system, DO rats were studied the changes of the unstable contraction after transection of the spinal cord (T(8) level), pelvic nerve, the sympathetic trunk, and the pudendal nerve. RESULTS: The incidence of DO was 62.5% in filling cystometry. During filling cystometry, there are two type of DO contraction according to the changes of pelvic afferent fiber signals, the relevant nerves and muscles responses: the small pressure of the unstable contraction (S-DO) and the big pressure of the unstable contraction (B-DO). For the B-DO, there were significant changes in the recordings of pelvic afferent fiber, the motor branch of the pudendal nerve, EUS EMG, and abdominal muscle EMG. While all these differences have not been recorded during S-DO. Both the filling-voiding cycle and the unstable contraction of B-DO were eliminated and the base line of bladder pressure increased after T(8) spinal cord transection. While the S-DO was not affected by such transection. When bladder relevant nerves were transected by the sequence of the pelvic nerve, the sympathetic trunk, and the pudendal nerve, the filling-voiding cycle was eliminated. The base line of bladder pressure increased significantly. No B-DO was recorded, but the S-DO still existed. CONCLUSION: There are some bladder-genic factors take part in the DO contractions induced by PBOO.

[Morphological study on the role of ICC-like cells in detrusor neuro-modulation of rat urinary bladder].

OBJECTIVE: To investigate the role of ICC-like cells in bladder neuromodulation in rat urinary bladder. METHODS: 14 SD rats and 1 guinea pig were sacrificed in this study. The ultra structural relationships among interstitial cells, nerves and detrusor smooth muscle cells (DSMCs) of urinary bladder were investigated by transmission electron microscopy (TEM). c-kit immunofluorescence was used to identify ICC-like cells in SD rat urinary bladder and the structural relationship between ICC-like cells and nerve terminals was studied by immunofluorescence (double-label). RESULTS: Gap junction between ICC-like cells and DSMCs was confirmed by TEM. ICC-like cells were very close apposition with nerve terminals under TEM. ICC-like cells were identified to exist in sub-urothelium layer, along the longitude of smooth muscle bundles and among detrusor smooth muscle in SD rat urinary bladder by c-kit immunofluorescence. Double-labeled tissue with c-kit and PGP9.5 antibodies also showed that ICC-like cells were very close apposition with nerve terminals in SD rat bladder. CONCLUSIONS: Morphological study indicated that ICC-like cells in rat urinary bladder may play an important role in detrusor neuromodulation. Further study on function will be helpful for elucidating the mechanism of bladder neuromodulation clearly.