Genomic Insight Into the Population Admixture History of Tungusic-Speaking Manchu People in Northeast China.

Manchu is the third-largest ethnic minority in China and has the largest population size among the Tungusic-speaking groups. However, the genetic origin and admixture history of the Manchu people are far from clear due to the sparse sampling and a limited number of markers genotyped. Here, we provided the first batch of genome-wide data of genotyping approximate 700,000 single-nucleotide polymorphisms (SNPs) in 93 Manchu individuals collected from northeast China. We merged the newly generated data with data of publicly available modern and ancient East Asians to comprehensively characterize the genetic diversity and fine-scale population structure, as well as explore the genetic origin and admixture history of northern Chinese Manchus. We applied both descriptive methods of ADMIXTURE, fineSTRUCTURE, F ST , TreeMix, identity by decedent (IBD), principal component analysis (PCA), and qualitative f-statistics (f 3, f 4, qpAdm, and qpWave). We found that Liaoning Manchus have a close genetic relationship and significant admixture signal with northern Han Chinese, which is in line with the cluster patterns in the haplotype-based results. Additionally, the qpAdm-based admixture models showed that modern Manchu people were formed as major ancestry related to Yellow River farmers and minor ancestry linked to ancient populations from Amur River Bain, or others. In summary, the northeastern Chinese Manchu people in Liaoning were an exception to the coherent genetic structure of Tungusic-speaking populations, probably due to the large-scale population migrations and genetic admixtures in the past few hundred years.

Obesity and Heath-Carter Somatotyping of 3438 Adults in the Xinjiang Uygur Autonomous Region of China by Multivariate Analysis.

INTRODUCTION: This study aimed to investigate the somatotype and obesity of adults in the Xinjiang Uygur Autonomous Region of China and to explore multivariate path analysis for the feasibility and scientificity of using somatotypes to evaluate obesity. SUBJECTS AND METHODS: According to anthropometric methods, a cross-sectional study was performed on 10 indexes of 3438 adults (1690 men and 1748 women, aged > 20 years) living in the Xinjiang Uygur Autonomous Region of China (including Kazakh, Kyrgyz, Xibe, Uzbek, Tatar and Tajik). The Heath-Carter anthropometric method and body mass index (BMI) were used to evaluate somatotype and obesity, respectively. The feasibility and scientificity of using somatotypes to evaluate obesity were analysed by correspondence analysis. RESULTS: Among the six populations, the somatotypes were mainly distributed as endomorphic mesomorph, mesomorph-endomorph and mesomorphic endomorph populations, accounting for 66.5% of males and 78.8% of females. The obesity rate (27.4% in males, 27.8% in females) of the six populations in the Xinjiang Uygur Autonomous Region of China was much higher than the average Chinese adult obesity rate (12.1%) and the global adult obesity rate (male: 11%, female: 15%). The distribution of BMI was significantly different (male: P=0.000, female: P=0.033) in different populations, and the incidence of overweight and obesity in the Xinjiang Uygur Autonomous Region of China increased gradually. This study found that there were significant differences in somatotype distribution among different obesity groups in the Xinjiang Uygur Autonomous Region of China (P=0.000). There was a strong correlation between overweight or obesity and endomorph-mesomorph, endomorphic mesomorph and mesomorphic endomorph. Furthermore, this study indicated that using somatotypes to evaluate obesity was reliable and scientific. CONCLUSION: This study concluded that the somatotype of overweight or obese people was mainly related to endomorphic mesomorph, mesomorph-endomorph, and mesomorphic endomorph.

Estimation of stature by using the dimensions of the right hand and right foot in Han Chinese adults.

The Han Chinese people are the main ethnic group in China and the largest ethnic group in the world. The dimensions of the hands and feet have been successfully used for the estimation of stature. A total of 26,927 healthy adult subjects, comprising 13,221 men and 13,706 women, were recruited. The survey samples were chosen through random cluster sampling. The mean values were significantly higher in men than those in women for all measurements (P<0.001). All the measurements showed a statistically significant correlation with stature (P<0.01). The combination of the right hand length and the right foot length was the best predictor of stature because it had the lowest standard error of estimate. The use of multiple regression equations yielded better results than did the use of linear regression equations. The accuracy of stature prediction ranged from ±4.81 to ±6.39 cm. The present study was of great importance with regards to improving the physical anthropology database of ethnic groups in China.

Chest circumference and sitting height among children and adolescents from Lhasa, tibet compared to other high altitude populations.

OBJECTIVES: The adaptation of human beings to a high altitude environment during growth has been reported in several populations but is less known for Tibetans. The objective of this study was to investigate similarities and differences of Tibetans in patterns and characteristics of physical growth and development in comparison to other high altitude populations. METHODS: We measured the stature, weight, chest circumference and sitting height of 2,813 healthy children and adolescents aged 6- to 21-year-old living at 3,658-4,500 m in Tibet, China, and compared them with published data from other high altitude populations. Eligible participants must have been born and raised in Tibet, and both their parents' families have to be Tibetan for at least the past three generations. RESULTS: The physical growth and development of children and adolescents in Tibet and the Andes followed similar patterns, such as delayed growth, short stature and sitting height, and large chest dimensions. Relative to stature, Tibetan sitting heights are similar to Andeans, but chest circumferences are smaller. CONCLUSIONS: Findings from this study reinforce the conclusion that Tibetan and Andean populations have adapted differently to high altitude hypoxia. The physical features of each population may result from unique adaptation to hypoxia, as well as socio-ecological factors, such as poor nutrition.

Study on the adult physique with the Heath-Carter anthropometric somatotype in the Han of Xi'an, China.

The study of somatotypes has important significance for medical and physical anthropology as well as sports science. The aim of this study was to understand the somatotype components of the Han population in Xi'an and compare the somatotypes of the Han and five other nationalities in China. The study sample consisted of 429 people of Han nationality (207 males, 222 females) from Xi'an, China, aged ≥20 years old. The Heath-Carter anthropometric method was employed. We evaluated the differences in age and sex by one-way ANOVA and t test. A comparison of somatotypes between the Han and other nationalities was made using the U test. The results showed that the male and female samples all could be classified as having a mesomorphic endomorph profile. The difference in endomorphy was strongest between sexes in all age groups (P < 0.01). There were prominent differences in mesomorphy and ectomorphy between males and females in the 50-59- and ≥60-year-old age groups. In females, the differences in somatotype components appeared to be distinguished between ages (P < 0.01 or P < 0.05). However, in males, there were prominent differences in somatotype components between the 20-29 year olds and all other age groups (P < 0.01 or P < 0.05) except for between those 20-29 and ≥60 years old in endomorphy. Compared with the other five nationalities, there were prominent differences in somatotype components between males and females. These results suggest that the somatotype of the Han population in Xi'an, China, has a predominantly mesomorphic endomorph profile. The endomorphic component shows distinct differences between ages and genders, respectively. Additionally, there are distinct differences in the somatotype components between Xi'an Han and five other nationalities in China in males and females.

The analysis on risk factors and clinical treatment of craniocerebral injury concurrent with acute kidney injury.

The main objective of this study was to investigate the risk factors and clinical treatment of craniocerebral injury concurrent with acute kidney injury. A total of 220 patients who suffered from craniocerebral injury from March 2010 to March 2012 in our Hospital were prospectively analyzed. Craniocerebral injury was defined according to the medical history, the verification of CT, and some investigated scores. The acute kidney injury was defined as a relative 47% increase of serum creatinine. The method of multivariate logistic regression analysis was used to evaluate the possible risk factors associated with post-craniocerebral injury concurrent with acute kidney injury. The clinical treatments of craniocerebral injury concurrent with acute kidney injury were also identified via experimental results, and the pathological mechanism of craniocerebral injury concurrent with acute kidney injury was found to be related to cerebral tissue lesions, but some potential factors were ambiguous. The incidence of acute kidney injury was 70.2% with craniocerebral injury. In hospital, mortality of acute kidney injury patients was 31.2%, which was 6.019 times of non-acute kidney injury patients (p < 0.01). The incidence of acute kidney injury in patients with craniocerebral injury was 58.3%, which was significantly higher compared to moderate and mild groups (p < 0.01). Unconditional multivariate logistic regression analysis results revealed that lower score, elderly, and male were the independent predictors of acute kidney injury episodes. Finally, some important factors were worthy of detailed study and further investigation.

Gender differences and age-related changes in body fat mass in Tibetan children and teenagers: an analysis by the bioelectrical impedance method.

OBJECTIVE: We aimed to obtain the fat base value and the fat distribution characteristics of Tibetan children and teenagers by estimating their body fat content with the bioelectrical impedance method. METHODS: We recruited 1427 healthy children and teenagers by a stratified cluster sampling method. By using bioelectrical impedance analysis, we obtained various values relevant to fat. RESULTS: We found that total body fat mass and the fat mass of various body parts increased with age in boys and girls. Yet there were no differences between age groups until 11 years. However, fat mass increased quickly between 11 and 18 years, and significant differences were seen between adolescent boys and girls; all fat indices were higher in girls than in boys (p<0.05). CONCLUSIONS: The characteristics of fat in Tibetan children and teenagers in Tibet is related to age and gender related hormone secretion, which reflects the physiological characteristics in different developmental stages.

Simvastatin attenuates angiotensin II­induced inflammation and oxidative stress in human mesangial cells.

Chronic kidney disease (CKD) is an intractable disease in which inflammation and oxidative stress are important. In the present study, the effect of simvastatin on inflammation and oxidative stress induced by angiotensin II (Ang II) in human mesangial cells (HMCs) and its corresponding mechanism was examined. In the in vitro experiment, HMCs were pretreated either without additives (control group) or with simvastatin at different concentrations (0, 0.1, 1 or 10 µM) for 1 h and were then stimulated by Ang II (1 µM) for 24 h. Following stimulation, the cells were collected for analysis using quantitative polymerase chain reaction, western blotting and dihydroethidium staining. The supernatant of the cells was collected and analyzed using an enzyme­linked immunosorbent assay. The results demonstrated that simvastatin suppressed the increased mRNA expression of monocyte chemoattractant protein­1, tumor necrosis factor­α, interleukin (IL)­1ß and IL­6 and the content of reactive oxygen species induced by Ang II in a dose­dependent manner. In addition, simvastatin decreased the protein expression of cyclooxygenase­2 (COX­2), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and protein kinase C (PKC) as well as the content of prostaglandin E2 and the phosphorylation level of nuclear factor­κB (NF­κB) p65 in a dose­dependent manner. Furthermore, simvastatin significantly increased the protein expression of peroxisome proliferator­activated receptor γ (PPARγ). Therefore, simvastatin suppressed inflammation and oxidative stress in Ang II­stimulated HMCs via COX­2, PPARγ, NF­κB, NADPH oxidase and PKCs, thereby exerting a protective effect on CKD.

Arctigenin attenuates lipopolysaccharide-induced acute lung injury in rats.

Arctigenin (ATG) has been reported to possess anti-inflammatory properties. However, the effects of ATG on lipopolysaccharide (LPS)-induced acute lung injury (ALI) remains not well understood. In the present study, our investigation was designed to reveal the effect of ATG on LPS-induced ALI in rats. We found that ATG pretreatment attenuated the LPS-induced ALI, as evidenced by the reduced histological scores, myeloperoxidase activity, and wet-to-dry weight ratio in the lung tissues. This was accompanied by the decreased levels of tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-1 (IL-6) in the bronchoalveolar lavage fluid. Furthermore, ATG downregulated the expression of nuclear factor kappa B (NF-κB) p65, promoted the phosphorylation of inhibitor of nuclear factor-κB-α (IκBα) and activated the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPKα) in the lung tissues. Our results suggested that ATG attenuates the LPS-induced ALI via activation of AMPK and suppression of NF-κB signaling pathway.

A comparison of measurement methods and sexual dimorphism for digit ratio (2D:4D) in Han ethnicity.

The digit ratio (2D:4D) is sexually dimorphic and has been considered an indicator of prenatal sex hormone exposure. Previous studies have shown that males tend to have lower 2D to 4D ratio than females, and this sexual dimorphism has been reported across different ethnic groups and different countries. However, digit ratio data are missing from the Han ethnicity in China. Furthermore, most of the previous studies used direct measurement for digit ratio. In this article, we used multiple measurement methods, including the direct measurement and two X-ray measurement methods to examine the trait of 2D:4D in Chinese Han. Our sample consisted of 128 men and 122 women from Liaoning Medical University. They were 18-20 years old. The direct measurement and two types of X-ray measurements of the length of their 2nd and 4th fingers were used separately to calculate digit ratios. Soft tissue thickness of 2D and 4D fingertips were also assessed from the two X-ray methods. The results suggest that (1) sex differences in 2D:4D tend to be stronger in the two X-ray measurements in comparison to the direct measurement; (2) 2D:4D ratios from X-ray measurements tend to be lower than that from the direct measurement; (3) Han ethnicity have a lower mean value of 2D:4D than other ethnic groups; (4) no sex difference in the soft tissue of finger tips. In conclusion, the digit ratio is lower in both men and women in Han, and the sexual dimorphism in digit ratio was stronger with X-ray measurements in comparison to the direct measurement.

7,8-dihydroxyflavone, a small-molecule tropomyosin-related kinase B (TrkB) agonist, attenuates cerebral ischemia and reperfusion injury in rats.

7,8-dihydroxyflavone (7,8-DHF) is a recently identified potent agonist of tropomyosin-related kinase B that can cross the blood-brain barrier after oral or intraperitoneal administration. The aim of the present study was to determine whether 7,8-DHF has neuroprotective effects against cerebral ischemia and reperfusion (I/R) injury and, if so, to investigate the possible underlying mechanisms. Cerebral I/R injury rats were induced by middle cerebral artery occlusion for 90 min followed by reperfusion for 24 h. 7,8-DHF was administered intraperitoneally at a dose of 5 mg/kg immediately after ischemia. Our results showed that 7,8-DHF significantly reduced neurological deficit scores, infarct volumes, and neuronal apoptosis in brains of I/R rats. Meanwhile, 7,8-DHF also increased Bcl-2 expression, decreased expression of cleaved caspase-3, Bax and inducible nitric oxide synthase, and inhibited nuclear factor-κB activation in ischemic cortex. Finally, malondialdehyde and nitric oxide contents were reduced, but activities of glutathione, glutathione peroxidase and superoxide dismutase were restored in ischemic cortex treated with 7,8-DHF. Taken together, our findings demonstrated that 7,8-DHF is able to protect against cerebral I/R injury, which may be, at least in part, attributable to its anti-apoptotic, anti-oxidative and anti-inflammatory actions.

Telomere, aging and age-related diseases.

Aging is an inevitable biological process that affects most living organisms. The process of aging is regulated at the level of the organism, as well as at the level of tissues and cells. Despite the enormous consequences associated with the aging process, relatively little systematic effort has been expended on the scientific understanding of this important life process. Many theories have been proposed to explain the aging process, the centerpiece of which is molecular damage. Located at the ends of eukaryotic chromosomes and synthesized by telomerase, telomeres maintain the stabilization of chromosomes. Thus, the loss of telomeres may lead to DNA damage. The relationship between cellular senescence and telomere shortening is well established. Furthermore, telomere attrition occurs with age, and is proposed to be a fundamental factor in the aging process. Here, we review the contemporary literatures to explore the current views on the correlation of telomere loss and telomerase action with aging and age-related diseases.

Quantitative analysis and comparison of BMI among Han, Tibetan, and Uygur university students in Northwest China.

OBJECTIVES: To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students' physical health. METHODS: The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20-24 in Northwest China, and their height and weight were measured to calculate BMI. The BMI classification criteria for Chinese established by Work Group on Obesity in China (WGOC) were used for screening. RESULTS: Han, Tibetan, and Uygur university students show low obesity rates but high overweight rates. Han, Tibetan, and Uygur university students present a high rate of underweight, normal weight, and overweight, respectively. Female Han students show higher underweight and normal weight rates, but lower overweight and obesity rates, than male Han students. Female Tibetan students show higher normal weight rate, but lower overweight and obesity rates, than male Tibetan students. BMI increases with age for male students but decreases with age for female students. Male Uygur students show higher obesity rate than female Uygur students. Tibetan and Uygur university students have higher BMI than other minorities in South China.

Aquaporin changes in compound 48/80 induced inflammatory sublaryngeal edema in rat.

OBJECTIVES/HYPOTHESIS: Laryngeal edema is a common clinical condition. However, the underlying molecular mechanisms remain elusive. Aquaporins (AQPs) are small integral plasma membrane proteins that transport water across the plasma membrane. In this study, we explore the relationship between inflammatory laryngeal edema induced by compound 48/80 and the expression of AQPs. STUDY DESIGN: Prospective, controlled, experimental animal study. METHODS: Healthy adult male SD rats were injected with either sterile water, compound 48/80 (2 mg/kg), or compound 48/80 plus dexamethasone (3 mg/kg) via the tail vein. The larynxes were harvested 10, 30 minutes, and 1 hour after the injection for the measurement of sublaryngeal water content and histological and molecular evaluations. RESULTS: Ten and 30 minutes after the compound 48/80 injection compared with the sterile water injection control groups, the water content in subglottic larynx increased significantly and the tissues were markedly swollen accompanied with inflammatory cell infiltration. AQP1 and AQP5 mRNA decreased significantly. One hour after the compound 48/80 injection, the edema was diminished, but the inflammatory cell infiltration remained. AQP1 was elevated but AQP5 was still lower than controls. Dexamethasone did not significantly reduce laryngeal edema, but significantly reduced inflammatory cells infiltration induced by compound 48/80 injection. Dexamethasone increased the AQP5 level but not AQP1. CONCLUSIONS: AQP1 and AQP5 might play key roles in inflammatory subglottic edema caused by compound 48/80 in rats. AQP1 and AQP5 might be useful molecular targets of clinical treatment of inflammatory laryngeal edema.

The traits of five types of tongue movement in Han of Shaanxi, China.

The study sample consisting of 429 people (207 males, 222 females) of Han nationality in Shaanxi, China. Five types of tongue movements were investigated, including tongue rolling, tongue folding, tongue twisting, pointed tongue and clover-leaf tongue. The results revealed that the frequencies of tongue rolling, tongue folding, tongue twisting, pointed tongue and clover-leaf tongue were 63.6, 14.0, 12.6, 54.8 and 0 %, respectively. There were no significant gender differences except with pointed tongue. Compared with other nationalities, tongue rolling, tongue folding, and pointed tongue of Han in Shaanxi had an average frequency. Tongue twisting and clover-leaf tongue had low frequencies. There were significant differences in frequency of clover-leaf tongue between Han and another seven nationalities of China (P < 0.01). Furthermore, only three pairs of trait correlations were exhibited among ten pairs of types of tongue movement combination traits when analyzed using Pearson's correlation coefficient. The data indicated that the correlations of tongue movement were between tongue rolling and tongue folding, between pointed tongue and tongue rolling, and also between tongue folding and pointed tongue, respectively. Additionally, there were significant differences in frequency of tongue movements with age. The possible mechanism of variations of tongue movements with aging may involve the degradation of tongue function, and differential gene activation and modulation, or protein translation.

Serum leptin concentration and its effect on puberty in Naqu Tibetan adolescents.

This study aimed to clarify the regularity of leptin in Naqu Tibetan adolescents. This study investigated the concentration of fasting serum leptin and clarified its relationship between BMI and other indices. Healthy Naqu Tibetan adolescents aged 12-18 were investigated randomly in the study. They were divided into seven groups (each year as one group, 12 boys and 12 girls in each group); serum concentrations of leptin, estradiol, testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were analyzed. The height and body weight of the 168 healthy Naqu Tibetan adolescents were also assessed. The leptin level in boys decreased with age but increased in girls; in boys and girls they both differed between groups (p<0.05). In boys, the leptin level was inversely correlated with body mass index (BMI), FSH, and T (p<0.05), while in girls, it was positively related to BMI, FSH, LH, and E2 (p<0.01).These findings suggested that during puberty the serum leptin concentration increased with age in girls while it decreased in boys; in the same age group, the leptin level in girls was significantly higher than in boys. Leptin may have some relationship with puberty in Tibetan adolescents.

The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT).

OBJECTIVE: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. METHOD: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. RESULTS: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). CONCLUSION: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

Estimation of human age according to telomere shortening in peripheral blood leukocytes of Tibetan.

In most normal somatic cells, the terminal restriction fragments (TRF) length and age are inversely correlated, which can be used to determine individual age. However, very little is known about the quantitative relationship between human telomeres and age. The aim of the present study was to investigate age-, gender-, and ethnicity-related changes in telomere length in human peripheral blood leukocytes (PBLs). Changes with age in telomere lengths were assessed by Southern blotting. The results shown that telomeres shorten in human PBLs in an age-dependent manner (r = -0.913, P < 0.01). The formula for age estimation according to telomere shortening was Y = -16.539X + 236.287 (Y: age, year; X: mean TRF length, kb). We analyzed the mean TRF length in males and females and found that males had shorter telomeres than females. Moreover, we compared the TRF length of Tibetan and Han population in China and found that telomere length did not differ between 2 populations. We conclude that estimation of human age according to telomere shortening in PBLs is a novel method especially when there is no morphologic information, furthermore, the gender must be considered when age estimation is carried out based on telomere shortening.

[Anatomical study of auditory brainstem implantation through retrosigmoid approach].

OBJECTIVE: To provide anatomic data for auditory brainstem implantation (ABI) through the retrosigmoid approach. METHODS: Simulated operations were performed on 30 web adult head specimens and the structure around the foramen of luschka was observed. Both microscope and endoscope were employed. RESULTS: (1)The bony window, the most adjacent but not overlapping with sigmoid sinus, was a circle with a radius of 20 mm. Its center was located behind midpoint of the line from parietal notch to mastoid apex with a distance of (26.42 +/- 1.29) mm. The distance between bony window and transverse sinus, mastoid apex, foramen of luschka, jugular foramen, posterior edge of internal auditory meatus and root entry zone of the IX cranial nerve were (22.45 +/- 1.41) mm, (35.51 +/- 1.65) mm, (43.86 +/- 2.20) mm, (16.56 +/- 1.64) mm, (15.01 +/- 0.63) mm and (46.27 +/- 1.70) mm respectively; (2) The foramen of luschka can be spotted by using microscope or endoscope, especially 30 degrees angled endoscope. By this way, we could obtain a more distinct visual field without over-retraction of cerebellum and achieve the goal of minimally invasive surgery. The distance between the foramen of luschka and internal acoustic porus was (15.01 +/- 0.53) mm; (3) The foramen of luschka lies in the triangle formed by flocculus and root entry zone of glossopharyngeal nerve and rostral margin of biventer lobule. Choroids plexus acts as a direct landmark. the length of lateral recess was (17.53 +/- 1.03) mm. The distance between acoustic tubercle and the foramen of luschka and the root of cochlea never was (16.52 +/- 1.67) mm and (13.77 +/- 1.66) mm respectively. CONCLUSION: Adjustment of the angle of skull bone window and clarification of cerebellopontine angle are the keys to positioning the foramen of luschka. The usage of 30 degrees angled endoscope can identify the angle are the keys to positioning the foramen of luschka. The usage of 30 degrees angled endoscope can identify the foramen of luschka more accurately and expose the operation area more clearly.