[Actively promoting the research and development of artificial intelligence diagnosis and treatment of orbital disease].

Medical artificial intelligence (AI) promotes technological revolution and industrial transformation in the medical field, and the medical level of orbital disease will also be improved with the in-depth development of AI diagnosis and treatment. The problems should be solved in the orbital disease AI research at the initial stage include: the complex knowledge system of orbital disease requires cross-disciplinary knowledge to improve the level of diagnosis and treatment; the early diagnosis and treatment of orbital disease is absent, and effective technical methods are needed to crack the screening dilemma; the operation of the disease is difficult, and special mechanical devices are needed to break through the boundaries of surgical technique; the medical team of orbital disease is scarce, and it is necessary to share the medical resources effectively. In order to solve the problems mentioned above, the following research directions of orbital disease AI diagnosis and treatment should be included: the orbital disease AI diagnosis system, the orbital disease AI screening platform, the orbital surgery robot and the orbital disease telemedicine. Through the development of multidisciplinary diagnosis and treatment, the in-depth exploration of interdisciplinary basic research, the extensive implementation of clinical research, and the extensive integration of industry and academic communication, the AI diagnosis and treatment of orbital disease is approaching a new era. (Chin J Ophthalmol, 2019, 55: 801-805).

[Tumor necrosis factor-α inhibitor protects against myocardial ischemia/reperfusion injury via Notch1 mediated inhibition of oxidative/nitrative stress in traumatic mice].

OBJECTIVE: To test the effects of TNF-α inhibitor Etanercept on myocardial ischemia/reperfusion (MI/R) injury in posttraumatic mice, and explore related mechanisms. METHODS: Traumatic mouse model was established with Noble-Collip drum. Five days after trauma, Notch1 was knocked down by intramyocardial injection of Notch1 small interfering RNAs (siRNA) or scrambled siRNA (20 µg). Seven days after trauma, mice were subjected to MI/R (30 minutes ischemia followed by reperfusion). Sham operation was similarly performed without coronary artery ligation. Ten minutes before reperfusion, mice received Etanercept (8 mg/kg, i. p.). ELISA was used to detect plasma levels of TNF-α and troponin I (cTnI) and myocardial nitrotyrosine content. Twenty-four hours after reperfusion, left ventricular ejection fraction (LVEF) was measured by echocardiography. Infarct size was determined by Evans blue/2, 3, 5-triphenyl tetrazolium chloride (TTC) double staining. Cardiac caspase-3 activity was detected using a caspase-3 kit. Myocardial TNF-α and Notch1 intracellular domains (Notch1 ICD) expressions were determined by Western blot. Chemiluminescence was used to assess myocardial superoxide anion content. RESULTS: (1) Compared to vehicle group, Etanercept treatment significantly reduced cTnI content, infarct size and caspase-3 activity (all P<0.01), while obviously increased LVEF (P<0.01). (2) Etanercept treatment also significantly reduced plasma and myocardial TNF-α contents (P<0.01), whereas markedly increased myocardial Notch1 ICD content (P<0.05). (3) Compared to scrambled siRNA group, Notch1 deficiency significantly increased cTnI content, infarct size and caspase-3 activity (P<0.05), whereas obviously reduced LVEF (P<0.05). (4) Etanercept significantly reduced myocardial superoxide anion and nitrotyrosine content (P<0.01), which was reversed by downregulation of Notch1 (P<0.05). CONCLUSIONS: TNF-α inhibitor Etanercept can alleviate MI/R injury after trauma by reducing myocardial oxidative/nitrative stress via activating Notch1 signaling pathway.

Evaluation of organic contamination in urban groundwater surrounding a municipal landfill, Zhoukou, China.

This paper investigates the organic pollution status of shallow aquifer sediments and groundwater around Zhoukou landfill. Chlorinated aliphatic hydrocarbons, monocylic aromatic hydrocarbons, halogenated aromatic hydrocarbons, organochlorine pesticides and other pesticides, and polycyclic aromatic hydrocarbons (PAHs) have been detected in some water samples. Among the detected eleven PAHs, phenanthrene, fluorine, and fluoranthene are the three dominant in most of the groundwater samples. Analysis of groundwater samples around the landfill revealed concentrations of PAHs ranging from not detected to 2.19 µg/L. The results show that sediments below the waste dump were low in pollution, and the shallow aquifer, at a depth of 18-30 m, was heavily contaminated, particularly during the wet season. An oval-shaped pollution halo has formed, spanning 3 km from west to east and 2 km from south to north, and mainly occurs in groundwater depths of 2-4 m. For PAH source identification, both diagnostic ratios of selected PAHs and principal component analysis were studied, suggesting mixed sources of pyro- and petrogenic derived PAHs in the Zhoukou landfill. Groundwater table fluctuations play an important role in the distribution of organic pollutants within the shallow aquifer. A conceptual model of leachate migration in the Quaternary aquifers surrounding the Zhoukou landfill has been developed to describe the contamination processes based on the major contaminant (PAHs). The groundwater zone contaminated by leachate has been identified surrounding the landfill.

The quantitative effect of diamond grit size on the subsurface damage induced in dental adjustment of porcelain surfaces.

Diamond burs with different grit sizes are often applied to adjust ceramic prostheses in restorative dentistry. However, the quantitative influence of diamond grit size on subsurface damage in adjusting ceramic prostheses is unknown. The aim of this study was to investigate and visualize the quantitative effect of diamond bur grit size on subsurface damage in dental adjusting of a feldspar prosthetic porcelain. Diamond burs with coarse (106-125 rm), medium (53-60 microm), and fine (10-20 microm) grit sizes were selected. Dental adjusting-induced subsurface damage was quantitatively investigated with the aid of finite element analysis (FEA) and scanning electron microscopy (SEM). Significant differences in subsurface damage depth were found among the coarse, medium, and fine diamond burs (ANOVA, p < 0.05). Coarse diamond burs induced approximately 6-8 times deeper subsurface damage than fine burs. Diamond grit size is confirmed to be a controlling factor in determining the degree of subsurface damage. Subsurface damage depths also significantly increased with removal rate (ANOVA, p< 0.05). The correlation of the SEM-measured subsurface damage depths and the diamond grit sizes supports the FEA predictions. From a practical standpoint, dental porcelains should be adjusted using smaller diamond grit sizes with lower removal rates to minimize subsurface damage.

Stress and damage at the bur-prosthesis interface in dental adjustments of a leucite-reinforced glass ceramic.

This article reports on the effects of dental adjustment parameters on stress and damage induced in a leucite-reinforced glass ceramic using a high-speed dental handpiece and coarse diamond burs. As one of machinable dental ceramics for prosthetic restorations, a leucite-reinforced glass ceramic has higher fracture toughness than feldspar porcelains. However, the extent of subsurface damage and stress induced in clinical dental adjustments is unknown. Tensile, shear, compressive and von Mises stresses at the bur-ceramic interface were investigated as functions of dental adjustment parameters using finite element analysis (FEA). The depths of subsurface damage were predicted using FEA according to the maximum principal stress criterion and experimentally measured using scanning electron microscopy (SEM). The resulting predicted subsurface damage depths agree well with the experimentally measured data. Both adjustment parameters, depth of cut and feed rate, were found to have significant influences on adjustment-induced stresses (P < 0.01) and subsurface damage (P < 0.01). It is also found that the predicted and measured subsurface damage depths increased linearly with the diamond grit depth of cut.

[Investigation of treatment and analysis of prognostic risk on enterocutaneous fistula in China: a multicenter prospective study].

Objective: To investigate the diagnosis and treatment for enterocutaneous fistula (ECF) in China, and to explore the prognostic factors of ECF. Methods: A multi-center cross-sectional study was conducted based on the Registration System of Chinese Gastrointestinal Fistula and Intra-Abdominal Infections to collect the clinical data of ECF patients from 54 medical centers in 22 provinces/municipalities from January 1, 2018 to December 31, 2018. The clinical data included patient gender, age, length of hospital stay, intensive care unit (ICU) admission, underlying diseases, primary diseases, direct causes of ECF, location and type of ECF, complications, treatment and outcomes. All medical records were carefully filled in by the attending physicians, and then re-examined by more than two specialists. The diagnosis of ECF was based on the clinical manifestations, laboratory/imaging findings and intraoperative exploration. Results: A total of 1521 patients with ECF were enrolled, including 1099 males and 422 females, with a median age of 55 years. The top three primary diseases of ECF were malignant tumors in 626 cases (41.2%, including 540 gastrointestinal tumors, accounting for 86.3% of malignant tumors), gastrointestinal ulcers and perforations in 202 cases (13.3%), and trauma in 157 cases (10.3%). The direct causes of ECF were mainly surgical operation in 1194 cases (78.5%), followed by trauma in 156 (10.3%), spontaneous fistula due to Crohn's disease in 92 (6.0%), radiation intestinal injury in 41 (2.7%), severe pancreatitis in 20 (1.3%), endoscopic treatment in 13 (0.9%) and 5 cases (0.3%) of unknown reasons. All the patients were divided into three groups: 1350 cases (88.7%) with simple ECF, 150 (9.9%) with multiple ECF, and 21 (1.4%) with combined internal fistula. Among the patients with simple ECF, 438 cases (28.8%) were jejuno-ileal fistula, 313 (20.6%) colon fistula, 170 (11.2%) rectal fistula, 111 (7.3%) duodenal fistula, 76 (5.0%) ileocecal fistula, 65 (4.3%) ileocolic anastomotic fistula, 55 (3.6%) duodenal stump fistula, 36 (2.4%) gastrointestinal anastomotic fistula, 36 (2.4%) esophagogastric/esophagojejunal anastomotic fistula, 29 (1.9%) gastric fistula and 21 (1.4%) cholangiopancreatiointestinal. Among all the simple ECF patients, 991 were tubular fistula and 359 were labial fistula. A total of 1146 patients finished the treatment, of whom 1061 (92.6%) were healed (586 by surgery and 475 self-healing) and 85 (7.4%) died. A total of 1043 patients (91.0%) received nutritional support therapy, and 77 (6.7%) received fistuloclysis. Infectious source control procedures were applied to 1042 patients, including 711 (62.0%) with active lavage and drainage and 331 (28.9%) with passive drainage. Among them, 841 patients (73.4%) underwent minimally invasive procedures of infectious source control (replacement of drainage tube through sinus tract, puncture drainage, etc.), 201 (17.5%) underwent laparotomy drainage, while 104 (9.1%) did not undergo any drainage measures. A total of 610 patients (53.2%) received definitive operation, 24 patients died within postoperative 30-day with mortality of 3.9% (24/610), 69 (11.3%) developed surgical site infection (SSI), and 24 (3.9%) had a relapse of fistula. The highest cure rate was achieved in ileocecal fistula (100%), followed by rectal fistula (96.2%, 128/133) and duodenal stump fistula (95.7%,44/46). The highest mortality was found in combined internal fistula (3/12) and no death in ileocecal fistula. Univariate prognostic analysis showed that primary diseases as Crohn's disease (χ(2)=6.570, P=0.010) and appendicitis/appendiceal abscess (P=0.012), intestinal fistula combining with internal fistula (χ(2)=5.460, P=0.019), multiple ECF (χ(2)=7.135, P=0.008), esophagogastric / esophagojejunal anastomotic fistula (χ(2)=9.501, P=0.002), ECF at ileocecal junction (P=0.012), non-drainage/passive drainage before the diagnosis of intestinal fistula (χ(2)=9.688, P=0.008), non-drainage/passive drainage after the diagnosis of intestinal fistula (χ(2)=9.711, P=0.008), complicating with multiple organ dysfunction syndrome (MODS) (χ(2)=179.699, P<0.001), sepsis (χ(2)=211.851, P<0.001), hemorrhage (χ(2)=85.300, P<0.001), pulmonary infection (χ(2)=60.096, P<0.001), catheter-associated infection (χ(2)=10.617, P=0.001) and malnutrition (χ(2)=21.199, P<0.001) were associated with mortality. Multivariate prognostic analysis cofirmed that sepsis (OR=7.103, 95%CI:3.694-13.657, P<0.001), complicating with MODS (OR=5.018, 95%CI:2.170-11.604, P<0.001), and hemorrhage (OR=4.703, 95%CI: 2.300-9.618, P<0.001) were independent risk factors of the death for ECF patients. Meanwhile, active lavage and drainage after the definite ECF diagnosis was the protective factor (OR=0.223, 95%CI: 0.067-0.745, P=0.015). Conclusions: The overall mortality of ECF is still high. Surgical operation is the most common cause of ECF. Complications e.g. sepsis, MODS, hemorrhage, and catheter-associated infection, are the main causes of death. Active lavage and drainage is important to improve the prognosis of ECF.

Effects of diethylhexyl phthalate (DEHP) on INSL3 mRNA expression by Leydig cells derived from mouse embryos and in newborn mice.

Insulin-like factor 3 (INSL3) regulates testicular descent during fetal life, and Insl3 gene inactivation results in cryptorchidism. Little is known, however, about whether the plasticizer diethylhexyl phthalate (DEHP), a contaminant found widely in the environment, influences INSL3 expression. In this study, primary cultures of Leydig cells from mouse embryos were treated in vitro with DEHP. We also treated pregnant mice with DEHP from gestation day 12 to postnatal day 3 in order to study the effect of DEHP in vivo. INSL3 mRNA expression levels in primary Leydig cell cultures and in the testes of newborn mice were significantly lower following DEHP treatment. DEHP also caused detrimental morphological changes in both primary cultures of Leydig cells and the testes of newborn mice. These results suggest that the downregulation of INSL3 mRNA by DEHP might cause abnormalities of gubernacular development, which might be one of the mechanisms for development of cryptorchidism.

In vitro study on high rotation deep removal of ceramic prostheses in dental surgery.

In vitro study on high rotation (up to over 300,000 rpm) deep removal (up to 150 microm) of ceramic prostheses, made of a machinable ceramic, Vita Mark II, was performed in dental surgery using a high-speed dental handpiece. Dental clinical removal relevance, including tangential and normal grinding forces, specific grinding energy, and surface roughness, was investigated to establish the relationships among the surgery parameters, chip geometry, and fracture mechanism. The results show that both the tangential and normal grinding forces increased with increases in both depth of cut and maximum undeformed chip thickness, but decreased with an increase in grinding speed. Specific grinding energy decreased with increase in the depth of cut and the maximum undeformed chip thickness, but increased with an increase in grinding speed. Surface roughness and morphology appeared to be independent of the increases in depth of cut, grinding speed, and maximum chip thickness. The limitation for deep removal using the dental handpiece was found that the operation at the depth of cut of 150 microm or beyond resulted in a huge normal force exertion of 3 N with a great variation. The microfracture, the lateral fracture, and the ductile microcutting were found to occur simultaneously in dental surgery to remove the ceramic prostheses.

[Expression of Fra-1 in laryngeal squamous cell carcinoma].

Objective:To investigate expressions of Fra-1 in laryngeal squamous cell carcinoma. Method:Using immunohistochemical method and RT-PCR detecting 47 cases of laryngeal squamous carcinoma tissues and 21 cases of para-carcinoma tissues with the level of protein and mRNA, we analyzed the relationship of the genes expression and clinical parameters. Result:The level of protein positive expression of Fra-1 genes in laryngeal squamous cancer tissue were higher than adiacent tissues (P<0.05). The expression of Fra-1 protein in laryngeal squamous cancer tissue were significant correlation with the clinical stages, lymph metastasis, smoking. They had no significant correlation with the pathological grade, age, anatomic zonation. The mRNA level expression of Fra-1 genes in laryngeal squamous cancer tissue were higher than adjacent tissues (P<0.01). The expression of Fra-1 gene in the mRNA level was correlated with pathologic stage, clinical stage, lymph metastasis, and smoking, but wasn't correlated with age and anatomic zonation. Conclusion:In laryngeal squamous cell carcinoma, the expression of Fra-1 gene are overexpressed. Fra-1 may play a role in the occurrence and development of the laryngeal cancer.

Myocardial elastogram using a fast mapping algorithm.

Ultrasound myocardial elastography is a promising technique to estimate regional myocardial function. In this study, we proposed a fast mapping method to map myocardial elastogram. A nude mouse's heart was scanned in supine position by an ultrasound system. The parasternal long-axis view of the heart and the ultrasound radio frequency (RF) signals were acquired for dynamic estimation of myocardial elasticity. The displacement and strain were calculated using analytic minimization (AM) and linear polynomial curve fitting method, respectively. The fast mapping method was proposed to map myocardial elastogram. The results display the contraction of myocardium intuitively. The method in this study is proved to have a potential to estimate viable myocardium in the future.

[Expression and correlation of Fra-1 and HMGA1 in laryngeal squamous cell carcinoma].

Objective: To investigate the expressions of Fra-1 and HMGA1 in laryngeal squamous cell carcinoma and their correlation. Methods: Immunohistochemistry and reverse transcription-polymer chain reaction (RT-PCR) were used to detect the expressions of HMGA1 and Fra-1 in laryngeal squamous carcinoma tissues in 47 cases and para-carcinoma tissues in 21 cases(the First Hospital of Shijiazhuang). The relationship between the gene expressions in carcinoma tissues and clinopathological parameters such as pathological grade, clinical stage, lymph metastasis, age and anatomic site and the relevance of the two gene expressions were analyzed. SPSS 13.0 software was used to analyze the data. Results: The positive expression rates of Fra-1 and HMGA1 proteins in laryngeal squamous cancer tissue were 48.9% and 53.2%, which were respectively higher than the rates of 19.0% for Fra-1 (χ(2)=5.416, P<0.05) and of 23.8% for HMGA1 (χ(2)=5.083, P<0.05) in adjacent tissues. The expression of Fra-1 gene was correlation with pathological grade, clinical stage and lymph metastasis (t values were -1.079, -1.066 and -1.067, all P<0.05), but not with age and anatomic site (t values were -1.068 and -1.054, both P>0.05). The expression of HMGA1 gene was correlation with pathological grade, clinical stage, lymph metastasis and age (t values were -1.112, -1.065, -1.009 and -1.066, all P<0.05), but not with anatomic site (t=-1.036, P>0.05). The expressions of Fra-1 and HMGA1 gene were positively correlation (r=0.672, P<0.05). Conclusions: In laryngeal squamous cancer, Fra-1 and HMGA1 are excessive expression, with a positive correlation between the expressions of both genes.

ZEB1 promotes prostate cancer proliferation and invasion through ERK1/2 signaling pathway.

OBJECTIVE: Prostate cancer is a kind of malignancy with high occurrence in the male urogenital system. However, the mechanism of the occurrence, the progression, and the metastasis of prostate cancer are still unclear. Searching for the effective molecule target is of great significance to improve the curative effect on prostate cancer. Zinc finger E box binding protein-1 (ZEB1) protein is a member of the zinc finger transcription factor family that participates in the embryonic development and formation. ZEB1 was found to be involved in the occurrence and in the development of multiple cancers, while its role in prostate cancer still needs elucidation. MATERIALS AND METHODS: Normal prostate cell line PC-3M and prostate cancer cell line DU145 were cultured in vitro and transfected by ZEB1 siRNA. ZEB1 mRNA and protein expressions were detected by real-time PCR and Western blot assay. Cell proliferation was determined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell migration was evaluated by transwell assay. Cell apoptosis was evaluated by caspase-3 activity. The impact of ZEB1 on extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling pathway was assessed by Western blot assay. RESULTS: ZEB1 expression significantly increased in DU145 cells compared with PC-3M cells (p<0.05). ZEB1 mRNA and protein obviously declined, cell proliferation inhibited, cell invasion suppressed, and Caspase-3 activity enhanced in DU145 cells after ZEB1 siRNA transfection (p<0.05). ZEB1 siRNA markedly decreased ERK1/2 phosphorylation in DU145 cells compared with control (p<0.05). CONCLUSIONS: Inhibition of ZEB1 promoted prostate cancer apoptosis, restrained proliferation, and suppressed invasion through down-regulating ERK1/2 signaling pathway.

The expression of OCT4 and its clinical significance in laryngeal squamous carcinoma tissues.

OBJECTIVE: To investigate the expression of OCT4 and its clinical significance in laryngeal squamous carcinoma tissues. PATIENTS AND METHODS: Immunohistochemical staining was used to analyze the expression of OCT4 in 61 cases of laryngeal squamous carcinoma and 10 cases of the adjacent normal laryngeal tissues. RESULTS: The expression of OCT4 was not detected in normal laryngeal tissues, but could be detected in the nucleus of laryngeal carcinoma. The positive expression rates of OCT4 in well-moderately differentiated and poorly differentiated laryngeal squamous carcinoma tissues were 25.6% (11/43) and 66.7% (12/18) respectively, and there were significant differences (p < 0.01). The expression of the OCT4 protein was related to lymph node metastasis and TNM stage (p < 0.05), but not to gender, age and position of the tumor (p > 0.05). CONCLUSIONS: OCT4 is expressed in laryngeal squamous carcinoma tissues and is closely related to the cell differentiation of laryngeal carcinoma, lymph node metastasis and clinical stage.

Surface integrity and removal mechanism in simulated dental finishing of a feldspathic porcelain.

Dental abrasive finishing of a fine-grained feldspathic porcelain was performed on a computer-assisted apparatus for simulation of a 2-degrees-of-freedom restorative operation with a dental handpiece and a coarse diamond bur of grit size of 106-125 mum. Finishing forces, surface roughness, and morphology were investigated as functions of finishing conditions. The tangential and normal forces were measured using a piezoelectric dynamometer and a data processing system. The results indicated that these forces increased with either the depth of cut or with the feed rate, in the ranges of 0.12-0.31 N and 0.45-1.09 N, respectively. However, an increase in either depth of cut or feed rate affected neither the surface roughness measured using a stylus profilometer nor the morphology observed under a scanning electron microscope. The finished porcelain surfaces were found to consist of the microfracture and chipping areas, ductile removal areas, smeared areas, and debris. Irregular fracture and chipping resulted from the extension of lateral/median cracks; ductile micromachining was attributed to the plastic deformation accompanied by distributed microcracks. It was determined that a combination of the microfracture and ductile micromachining was the primary mechanism for material removal.

Performance evaluation of a dental handpiece in simulation of clinical finishing using a novel 2DOF in vitro apparatus.

This paper reports on the performance evaluation of a dental handpiece in simulation of clinical finishing using a novel two-degrees-of-freedom (2DOF) in vitro apparatus. The instrumented apparatus consisted of a two-dimensional computer-controlled coordinate worktable carrying a dental handpiece, a piezoelectric force dynamometer, and a high-speed data acquisition and signal conditioning system for simulating the clinical operations and monitoring the dental finishing processes. The performance of the dental handpiece was experimentally evaluated with respect to rotational speed, torque, and specific finishing energy under the applied clinical finishing conditions. The results show that the rotational speeds of the dental handpiece decreased by increasing either the depth of cut or the feed rate at a constant clinically applied air pressure and water flowrate. They also decreased when increasing both the tangential and normal finishing forces. The specific finishing energy decreased with an increase in either depth of cut or feed rate, while the finishing torque increased as either the depth of cut or the feed rate was increased. Implications of these results were to provide guidance for proper applications of dental handpieces in clinical practice.

[Advances in the research of promotion effect of Aloe vera on wound healing and its clinical use].

Aloe vera has been widely investigated and used as folk medicine since ancient time. Biologically active substances in its gel include polysaccharides, glycoprotein, enzymes, anthraquinones or phenolic compounds, vitamins, minerals, and so on, which play important roles in anti-inflammatory response, antimicrobial, antiviral, antioxidant activity, immunoregulation effects, and especially in wound healing. In this paper, we review the advances in the mechanism and clinical application of Aloe vera and its extract on wound healing, so as to provide new ideas for the treatment of various kinds of wounds.

Electrical level of defects in single-layer two-dimensional TiO2.

The remarkable properties of graphene and transition metal dichalcogenides (TMDCs) have attracted increasing attention on two-dimensional materials, but the gate oxide, one of the key components of two-dimensional electronic devices, has rarely reported. We found the single-layer oxide can be used as the two dimensional gate oxide in 2D electronic structure, such as TiO2. However, the electrical performance is seriously influenced by the defects existing in the single-layer oxide. In this paper, a nondestructive and noncontact solution based on spectroscopic ellipsometry has been used to detect the defect states and energy level of single-layer TiO2 films. By fitting the Lorentz oscillator model, the results indicate the exact position of defect energy levels depends on the estimated band gap and the charge state of the point defects of TiO2.

The role of Ca2+ and protein kinase C in the acrosome reaction of giant panda (Ailuropoda melanoleuca) spermatozoa.

Fresh semen was collected from adult male giant pandas and the role of Ca2+, Ca2+ ionophore A23187 and protein kinase C (PKC) in sperm motility and acrosome reaction (AR) was assessed by lens culinaris agglutinin conjugated with fluorescein isothiocyanate (FITC-LCA) labeling and transmission electron microscopy. The AR in giant panda spermatozoa was characterized by vesiculation of the outer acrosomal membrane through its invagination. Both the sperm motility and the AR rate decreased significantly (p < 0.05) in Ca2+-free and low Ca2+ medium. The addition of 10 microM Ca2+ ionophore A23187 potently stimulated AR. After incubation for capacitation, the PKC activator phorbol 12-myristate 13-acetate (PMA) stimulated AR in a dose-dependent manner and its effect could be overcome by the PKC inhibitor staurosporine. These results suggest that Ca2+ and PKC play an important role in the sperm acrosome reaction of the giant panda.

Study on in vitro sperm capacitation and egg-penetration of giant panda.

A preliminary report on in vitro sperm capacitation and egg-penetration of giant panda is briefly presented. The panda spermatozoon consists of head, neck and tail, just like the spermatozoa of other animals. Before capacitation sperm heads clustered together and dispersed after capacitation. They were then able to swim straight forward. During the time of in vitro capacitation the plasma membrane of the sperm head was first expanded to various degrees, then disintegrated, and finally became detached. The electro-dense material in the acrosome appeared in small clumps with high density. Extensive vesiculation occurred between the bi-layered acrosome membranes and thus led to disintegration. Vesiculation in panda sperm differs from that reported in hamsters. When the capacitated panda spermatozoa came into contact with the hamster eggs, the region between the acrosome collar and postacrosome cap first fused with the egg membrane followed by the penetration of the nucleus into the cortex of the egg. Some of the penetrating sperm nuclei became decondensed and some did not. The success of in vitro sperm capacitation and egg-penetration of giant panda is of great significance, suggesting that it is possible to carry out in vitro fertilization and embryo transplantation in this endangered species.