CCL2 promotes lymphatic metastasis via activating RhoA and Rac1 pathway and predict prognosis to some extent in tongue cancer

BACKGROUND

Oral tongue cancer is an extremely malignant tumor with high rate of lymphatic metastasis. Little is known about its invasion and metastasis mechanisms so far.

METHODS

To clarify the main role of CCL2 in tongue cancer progression, we performed Transwell migration assay to confirm the effects of different concentrations of CCL2 on the migration and invasion of tongue cancer cells. Next, by siRNA interference of RhoA and Rac1 in LNMTca8113 cells, we are able to observe that these two molecules block the effect of CCL2 on cell migration and cytoskeleton reorganization by laser confocal microscopy. Moreover, the AKT phosphorylation level of PI3K downstream molecule under the action of CCL2 also be detected by qRT-PCR and western blot, so as to determine whether CCL2 affects the proliferation of LNMTca8113 cells through PI3K/AKT pathway. Finally, we analyzed the relationship between plasma CCL2 level and various clinicopathological parameters in patients with tongue cancer. Results: We found that tongue cancer cells treated with CCL2 migrate faster at first. CCL2 may enhance the invasion and migration of LNMTca8113 cells by activating RhoA and Rac1 to promote cytoskeleton reorganization. Promotion of LNMTca8113 migration induced by CCL2 was inhibited by silence of RhoA and Rac1. CCL2 could increase the phosphorylation of downstream Akt/PI3K signal and promoted the proliferation. Plasma concentration confirmed that the CCL2 level was closely related to the clinical stage of tongue cancer. Patients with lower CCL2 levels had a relatively longer progression-free survival and total survival time.

RESULTS

After adding CCL2, the number of proliferation and migration of tongue cancer cells increased and the expression of RhoA and Rac1 rose up in LNMTca8113 cell line. The cytoskeleton reorganization was notable. Patients with higher serum levels of CCL2 had shorter progression-free survival than those with lower levels of CCL2 (P < 0.0001).

CONCLUSIONS

CCL2 promotes the invasion and metastasis of tongue cancer by PI3K/Akt pathway. The plasma level of CCL2 may predict prognosis of tongue cancer patients. CCL2 can serve as a potential therapeutic target for tongue cancer treatment.

Learning curve of trans-areola single-site endoscopic thyroidectomy in a high-volume center: A CUSUM-based assessment

BACKGROUND

Limited attempts have been made in trans-areola single-site endoscopic thyroidectomy (TASSET) due to technical challenges and the lengthy time for proficiency. This study aimed to define the learning curve of TASSET and to describe improvements in operative performance over time.

METHODS

Based on 222 consecutive TASSET procedures, the learning curve was established according to the operation time by using cumulative sum analysis (CUSUM). The end-point of learning curve was defined as the number of cases necessitated to reach the initial surgical proficiency stage. The demographic information, surgical and oncological outcomes, surgical stress, and postoperative complications were also analyzed.

RESULTS

There were 70 cases of simple lobectomy for benign nodules and 152 cases of lobectomy with central neck dissection (CND) for malignancy. The mean operative time was 106.54 ± 38.07 min (range: 46-274 min). The learning curve identified two phases: the skill acquisition phase (Case 1-Case 41) and the proficiency phase (Case 42-Case 222). There were no significant differences in demographic information, drainage amount and duration, oncological outcomes, and postoperative complications between the two phases (p > 0.05). Both operation time and postoperative hospitalization decreased significantly in Phase 2 (154.63 ± 52.21 vs. 95.64 ± 22.96 min, p < 0.001; 4.12 ± 0.93 vs. 3.65 ± 0.63 days, p < 0.001). Additionally, the mean variations of surgical stress factors (C-reactive protein and erythrocyte sedimentation rate) decreased significantly as the phase progress. The case number required for proficiency phase in benign and malignant tumor were 18 and 33, respectively, and lymph node resection posed a significant impact on the endpoint of the learning curve (p < 0.001). Meanwhile, the size of nodule showed no significant impact (p = 0.622). For right-handed surgeons, 16 cases and 25 cases were required for technical competence in left-sided and right-sided lesions, respectively, and no significant difference reached (p = 0.266).

CONCLUSIONS

TASSET has demonstrated safe and technically feasible with comparable oncological outcomes. Experience of 41 cases was required for surgical competence and proficiency. The initial learning stage could be more quickly adopted by high-volume thyroid surgeons with standardized procedures.

Reconstruction of Buccal-penetrating Defects Using the Double-folded Lateral Arm Free Flap

The reconstruction of buccal-penetrating defects remains challenging. The present study aims to explore the application value of the lateral arm free flap (LAFF) on the reconstruction of buccal-penetrating defects with the hope of providing a better option for clinical practice. Nineteen patients with this kind of issue posed by either tumor resections or deformities in the craniofacial regions were recruited in this study, and LAFF was employed to reconstruct these defects by double folding and individually designing the flap. All the flaps prepared for these subjects in our study survived, and the postoperative assessment of these subjects receiving LAFF revealed that this approach to managing buccal-penetrating defects is able to achieve satisfactory results in terms of appearance and functional recovery. Therefore, our study suggests that LAFF is 1 of the promising flaps to reconstruct the buccal-penetrating defects.

CXCL1 promoted the migration and invasion abilities of oral cancer cells and might serve as a promising marker of prognosis in tongue cancer

BACKGROUND

Oral tongue squamous cell carcinoma tends to metastasize to cervical lymphatic nodes early which leads to a 50% drop of survival rate. CXCL1 could be secreted by LNMTca8113 cell induced lymphatic endothelial cells and promoted LNMTca8113 cell migration. The current study aimed to further explore the effect of CXCL1 on the proliferation and migration abilities of tongue cancer cells and the prognostic value of serum CXCL1 in oral tongue squamous cell carcinoma.

METHODS

Cell proliferation and migration ability were analysed by CCK8 assays and transwell migration assays. Immunofluorescence technique was used to show cytoskeleton. GST pull-down assay was applied to quantify the activation of GTPases. Blood samples of patients were collected and clinicopathological characteristics were analysed.

RESULTS

CXCL1 could promote cancer cell proliferation in appropriate concentration by PI3K/AKT pathway. It also regulated the activation of Rho GTPases to mediate the rearrangements of cytoskeleton to promote tumour cell migration. Level of plasma CXCL1 could predict the possibility of early lymphatic metastasis and had a predictive value in progression-free survival and overall survival.

CONCLUSIONS

CXCL1 could promote oral cancer cell proliferation, migration and invasion in vitro and contributed theoretical knowledge for the target selection in molecular targeted therapy. Level of plasma CXCL1 might serve as a biomarker for prognosis in oral tongue squamous cell carcinoma patients.

Single incision-plus approach for gasless endoscopic parotidectomy: a seven-step procedure

Endoscopic parotidectomy has the potential to become a reliable procedure for benign and low-grade malignant parotid gland tumors. Based on the previous literature review and our own clinical experience, we introduced in detail the surgical procedure of single incision-plus approach for gasless endoscopic parotidectomy. This method contributes a logical approach to achieving endoscopic resection of parotid gland tumor and preservation of facial nerve, which can be summarized into the following seven-step method: preoperative preparation; design of retroauricular-hairline incision and plus-incision; surgical cavities creation and coalescence; separation of surgical boundaries; separation and protection of the facial nerve trunk; processing of the branches of facial nerve; en bloc resection of the superficial parotid gland and tumor. Endoscopic parotidectomy is a more difficult procedure than conventional parotid surgery, requiring more precision as well as more experience and equipment. The learning curve of time and frequency is influenced by many factors, like anatomy, instruments, procedures and patience. We contribute our clinical exploration of anatomical precautions, feasible instruments, and surgical procedures and summarize precautions under single incision-plus in gasless endoscopic parotidectomy. Given the growing interest in the aesthetic process of the parotid region, the seven-step method may have the potential to be a method for teaching gasless endoscopic parotidectomy.

The central role of a two‐way positive feedback pathway in molecular targeted therapies‐mediated pyroptosis in anaplastic thyroid cancer

Background

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive tumours. We previously confirmed that apatinib has potential therapeutic effects on ATC via regulated cell death (RCD). As a newly identified RCD, pyroptosis demonstrates direct antitumour activity different from apoptosis or autophagy. Therefore, the clinical significance, regulatory role and underlying mechanisms of pyroptosis in ATC were focused on in this study.

Methods

In a phase II trial, patients with anaplastic or poorly differentiated thyroid carcinoma received apatinib 500 mg once daily. Multiple assays were implemented to evaluate the antitumour efficacy of apatinib and/or melittin in vitro and in vivo. High‐throughput sequencing was applied to analyse differential mRNAs expression in ATC cells treated by apatinib with or without melittin. In situ Hoechst 33342/PI double‐staining, LDH release assay and enzyme‐linked immunosorbent assay (ELISA) were employed to determine pyroptosis. In mechanism exploration, quantitative RT‐PCR, Western blotting and si‐RNA knocking down were executed.

Results

Seventeen patients were evaluable. Apatinib showed a promising therapeutic effect by a disease control rate (DCR) of 88.2%; however, treatment was terminated in 23.5% of patients due to intolerable toxicity. To reduce adverse events, a pyroptosis‐mediated synergistic antitumour effect of apatinib and melittin was identified in treatment of ATC in vitro and in vivo. The caspase‐1–gasdermin D (GSDMD) axis‐mediated pyroptosis was the key to extra antitumour effect of the combination of apatinib and melittin. Moreover, caspase‐3–gasdermin E (GSDME) pyroptosis pathway also functioned importantly in addition to caspase‐1–GSDMD pathway. Evidenced by in vitro and in vivo study, a two‐way positive feedback interaction was innovatively confirmed between caspase‐1–GSDMD and caspase‐3–GSDME axes.

Conclusions

Through pyroptosis mediated by caspase‐1–GSDMD and caspase‐3–GSDME axes synchronically, low‐dosage apatinib and melittin could synergistically achieve a comparable therapeutic potential with reduced AEs. More importantly, a two‐way positive feedback interaction is innovatively proposed between these two axes, which provide a new prospect of targeted therapy.

Sentinel lymph node biopsy versus elective neck dissection in squamous cell carcinoma of the oral cavity with a clinically N0 neck: Systematic review and meta-analysis of prospective studies

Sentinel lymph node biopsy (SLNB) is an emerging strategy for managing early-stage oral squamous cell carcinoma (SCC) with a clinically N0 (cN0) neck. However, the role of SLNB in this scenario is debatable. Herein, relevant literature was systematically reviewed, and a meta-analysis was performed to evaluate the potential dividends of SLNB compared to elective neck dissection (END) for these patients. The meta-analysis, including six prospective studies, showed comparable results of the two management strategies in terms of regional recurrence (risk ratio [RR] = 0.99; 95% confidence interval [CI], 0.58-1.70), 5-year disease-free survival (RR = 0.99; 95% CI, 0.87-1.11), and 5-year overall survival (RR = 1.01; 95% CI, 0.90-1.13). Fewer adverse events occurred in the SLNB arm than in the END arm (RR = 0.12; 95% CI, 0.02-0.70). Overall, SLNB results in as favorable an oncologic prognosis for patients with cN0 oral SCC as END, while significantly lessening side effects and unnecessary surgeries.

Evaluation of Postoperative Repair Effect of Oral Tumors Based on Free Ultrasound Flap Transplantation

In this paper, the treatment of oral tumors with free flap transplantation based on ultrasound contrast is studied, and the repair effect is analyzed and evaluated in-depth, the postoperative quality of life of patients with oral malignant tumors is evaluated, and the factors affecting their quality of life are analyzed. 120 patients with oral malignant tumors were selected. The continuity of the jaws, neck clearance method, clinical stage, tumor recurrence, radiotherapy, and chemotherapy all have varying degrees of impact on the postoperative quality of life. Multivariate analysis suggests that tumor recurrence has the greatest impact on the quality of life of patients followed by jaw continuity, tumor stage, with or without neck clearance. First, the early detection rate of tumors should be improved, and the tumors should be removed as completely as possible during the operation to avoid residues. If necessary, cervical lymph node dissection can be performed. Patients with discontinuous jaws should be reconstructed and repaired in time to restore the maxillofacial shape and function of the patients, to greatly reduce the impact on the quality of life of patients after surgery.

Thyroidectomy for thyroid cancer via transareola single-site endoscopic approach: results of a case-match study with large-scale population

BACKGROUND

Due to technical challenges, single-site endoscopic thyroidectomy (SSET) is seldom reported and has been attempted in only limited cases. This large-scale study aimed to compare the clinical outcomes of standardized transareola SSET (TASSET) with those of conventional open thyroidectomy (COT) for thyroid cancer.

METHODS

The data were prospectively collected, and case-match study was performed at a ratio of 1:1 according to age, sex, body mass index, lesion size, number of lesion foci, lesion side, recurrent laryngeal nerve (RLN) exploration and pathology. Two hundred eligible patients underwent TASSET, and the same number of patients was selected for propensity score matching from 2256 patients who underwent COT. Perioperative data, including surgical profile, oncological and traumatic burdens, and cosmetic satisfaction, were analyzed.

RESULTS

No significant differences were observed in blood loss or drainage between TASSET and COT groups. There were no differences in operation time between TASSET and COT (106.39 ± 28.44 vs 102.55 ± 23.10 min, p = 0.154). A total of 3.63 ± 1.82 lymph nodes (LNs) were retrieved from CND with 0.96 ± 1.42 positive in TASSET. In COT, the total and positive LN yields were 3.77 ± 1.91 and 0.99 ± 1.40 (p = 0.445, p = 0.802). Cancer recurrence was not observed in either group. There were no differences in the occurrence of permanent and transient hoarseness or RLN injuries. Postoperative flap seroma or hematoma occurred in 12 TASSET patients and 58 COT patients (p < 0.001). The pain score, CRP level and ESR in TASSET group were lower than those in COT group. TASSET yielded significantly better incision recovery and cosmetic scores than did COT at both the proliferation and stabilization stages.

CONCLUSIONS

TASSET is technically feasible and yields enhanced recovery with minimally invasive and cosmetic advantages without compromising the level of safety or cancer eradication.

Nanotechnology-based drug delivery systems for enhanced diagnosis and therapy of oral cancer

Oral cancer is a common malignant life-threatening tumor. Despite some advances in traditional therapy, mortality and mobidity rates are high due to delayed diagnosis and ineffective treatment. Additionally, some patients inevitably suffer from various fatal adverse effects during the course of therapy. Therefore, it is imperative to develop novel methods to eradicate oral cancer cells with minimal adverse effects on normal cells. Nanotechnology is a promising and novel vehicle for the diagnosis and treatment of oral cancer with encouraging recent achievements. In this review, we present state-of-the-art nanotechnology-based drug delivery systems employed in the domain of oral cancer, especially for its enhanced diagnosis and therapy. We describe in detail the types of nanotechnology used in the management of oral cancer and summarize administration routes of nanodrugs. Finally, the potential and prospects of nanotechnology-based drug delivery systems as promising modalities of diagnosis and therapy of oral cancer are highlighted.

Comparison of contrast-enhanced ultrasound and contrast-enhanced computed tomography for the diagnosis of cervical lymph node metastasis in squamous cell carcinoma of the oral cavity

Early detection of cervical lymph node metastasis (CLNM) from squamous cell carcinoma (SCC) of the oral cavity remains challenging. This prospective study was performed to evaluate the ability of contrast-enhanced ultrasound (CEUS) to detect CLNM from oral cavity SCC. Additionally, its diagnostic value was compared with that of contrast-enhanced computed tomography (CECT). Forty-eight consecutive patients with SCC of the oral cavity were enrolled. All subjects were examined preoperatively with both CEUS and CECT. Subsequently, neck dissections were performed for these patients, and cervical lymph nodes separated from the surgical specimens were assessed histologically. The diagnostic performance of these two examinations was compared based on the results of histopathology. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and Youden index for CEUS and CECT were 69.39% vs. 44.90%, 94.71% vs. 97.12%, 89.88%% vs. 87.16%, 75.56% vs. 78.57%, 92.92% vs. 88.21%, and 64.10% vs. 42.02%, respectively. A significant difference was observed in terms of sensitivity (P=0.024) and Youden index (rate difference 22.08%, 95% confidence interval 2.72-41.44%). Therefore, CEUS appears to be a promising diagnostic tool that is superior to CECT for detecting CLNM from SCC of the oral cavity, with a higher sensitivity.

Double-Layer Microsphere Incorporated with Strontium Doped Calcium Polyphosphate Scaffold for Bone Regeneration

To design and prepare a novel controlled release system for sustained release of two drugs. In this study, a double-layer microsphere was incorporated with strontium-doped calcium polyphosphate (SCPP) scaffold to facilitate bone regeneration and achieve skull repair. The double-layer microsphere combining tetracycline loaded sodium alginate and matrix metalloproteinase-2 (MMP-2) loaded chitosan was manufactured by electrospinning, which were further adhered to SCPP scaffold. The characteristics of microstructure were observed through scanning electron microscope. Loading efficiencies and the optimal ratio of microsphere of the obtained controlled release system were investigated. In addition, the cytotoxicity and the effects on osteoblast proliferation and expressions of osteogenesis-related factors were examined in vitro. Thereafter, the compound material with the controlled release system was implanted in the skull defect of rabbit to evaluate its properties of promoting bone regeneration. The results indicated that this novel controlled release system with SCPP scaffold and the double-layer microspheres loaded with tetracycline and MMP-2 could be a promising material for bones repair.

Elective Neck Dissection Versus Observation in Squamous Cell Carcinoma of Oral Cavity With Clinically N0 Neck: A Systematic Review and Meta-Analysis of Prospective Studies

PURPOSE

To assess the possible benefits of elective neck dissection (END) in patients with squamous cell carcinoma (SCC) of the oral cavity and clinically N0 neck.

MATERIALS AND METHODS

Medline, Embase, the China National Knowledge Infrastructure, and the Wan Fang Database were systematically searched. A meta-analysis was performed to evaluate the possible benefits of END to such patients.

RESULTS

Six prospective studies involving 865 patients fulfilled the inclusion criteria. Meta-analysis of all included studies showed that END substantially lowered the risk of regional recurrences (risk ratio [RR] = 0.27; 95% confidence interval [CI], 0.21-0.36) in the fixed-effect model compared with observation only. Three of the 6 included studies showed that the specific death rate related to regional recurrences was lower in the END group than in the observation group in the fixed-effect model (RR = 0.35; 95% CI, 0.19-0.65). The mean metastasis rate of occult cervical lymph node was 30.27% (standard deviation, 9.42%). When the fixed-effect model was applied, 4 of the 6 included studies showed less recurrence in the END group compared with the observation group (RR = 0.53; 95% CI, 0.44-0.64).

CONCLUSIONS

END substantially decreases recurrences and deaths related to regional recurrences in early-stage SCC of the oral cavity with clinically N0 neck, especially SCC of the oral tongue and floor of the mouth, which is necessary for such patients.

Carcinoma associated fibroblasts derived from oral squamous cell carcinoma promote lymphangiogenesis via c-Met/PI3K/AKT in vitro

Carcinoma-associated fibroblasts (CAFs) are dominant components of the tumor microenvironment (TME) that promote the development, progression and metastasis of cancer. c-Met is a receptor of the hepatocyte growth factor (HGF), which is involved in lymphangiogenesis. Currently, the roles of CAFs during lymphangiogenesis are unknown. It has been hypothesized that CAFs contribute to lymphangiogenesis of oral squamous cell carcinoma (OSCC) via a HGF/c-Met complex. The expression of HGF in OSCC was determined using CAFs derived from OSCC tissue and it was demonstrated that HGF is overexpressed in OSCC-derived CAFs. It was also revealed that c-Met was highly expressed in human lymphatic endothelial cells (HLECs) when co-cultured with CAFs. Furthermore, it was demonstrated that recombinant human HGF significantly enhanced the proliferation, migration, invasion and tube formation of HLECs. By contrast, the inhibition of c-Met expression suppressed the aforementioned biological activities and also downregulated the expression of c-Met, phosphoinositide 3-kinase and phosphorylated protein kinase B. Taken together, these data demonstrate that c-Met is associated with the regulation of lymphangiogenesis. Thus, the results of the present study indicate that c-Met may be a promising novel therapeutic target to treat patients with OSCC.

Difference in resting-state fractional amplitude of low-frequency fluctuation between bipolar depression and unipolar depression patients

OBJECTIVE

To investigate the difference in fractional amplitude of low-frequency fluctuation (fALFF) of localized brain activities in the resting-state between bipolar depression and unipolar depression patients and to find biological markers that differentiate the two groups of patients.

PATIENTS AND METHODS

Thirteen patients with bipolar depression, 15 patients with unipolar depression, and 16 healthy control subjects that were matched in age and years of education were subjected to 3.0 T resting-state functional magnetic resonance scans. The values of whole brain fALFF were calculated and statistical analysis was performed.

RESULTS

The fALFF-values of the right inferior temporal gyrus, left cerebellar posterior lobe, right middle temporal gyrus, left inferior frontal gyrus/insula, right inferior frontal gyrus/insula, left lingual gyrus and right middle temporal gyrus of the three groups showed significant differences (p < 0.05). Compared with the healthy control (HC) group, the fALFF-values of the unipolar depression (UD) patient group significantly increased in the right superior temporal gyrus, left insula, left inferior frontal gyrus, right inferior frontal gyrus, right supramarginal gyrus and right medial frontal gyrus but significantly decreased in the right medial occipital gyrus, left frontal lobe, right superior parietal lobule; the fALFF-values of the bipolar depression (BD) patient group significantly decreased in the left cerebellum posterior lobe, right lingual gyrus, left lingual gyrus, right middle temporal gyrus, left middle temporal gyrus, and left superior frontal gyrus and significantly increased in the right inferior frontal gyrus and left insula compared to those of the HC group; compared with those of the UD group, the fALFF-values of the BD group significantly decreased in the left middle occipital gyrus, right middle temporal gyrus, left middle frontal gyrus, and left medial frontal gyrus.

CONCLUSIONS

The brain activities of BD and UD patients in the resting-state exhibit abnormalities, which differ between the two groups of patients.

[Effects of oral cancer-associated fibroblasts on the proliferation, migration, invasion and tube formation to human lymphatic endothelial cells]

OBJECTIVE

To investigate the effects of oral cancer-associated fibroblasts (CAFs) on lymphangiogenesis in oral squamous cell carcinoma (OSCC).

METHODS

CAFs and normal fibroblasts (NFs) were obtained from the tissues of patients with OSCC who did not receive radio-chemotherapy before operation. And the CAFs and NFs were isolated by method of tissue block and identified by immunohistochemical staining. The effects of CAFs (group A) and NFs (group B) to human lymphatic endothelial cells (HLEC) were detected by using a 24-multiwell transwell cell culture chamber. DMEM sugar medium was as blank control group. The number of proliferative, migratory, invasive and tubes of HLEC were counted under inverted phase contrast microscope.

RESULTS

The proliferative number of HLEC of group A for 96, 144, 196 h was significantly higher than that of group B and blank control group, group B higher than blank control group (P<0.01). The migratory and invasive number of HLEC of group A for 96 h was significantly higher than that of group B and blank control group, group B higher than blank control group (P<0.01). The number of tube formation of HLEC of group A for 24 h was significantly higher than that of group B and blank control group, group B higher than blank control group (P<0.01).

CONCLUSION

CAFs promote HLEC's proliferation, migration, invasion, tube formation, and these effects are stronger than NFs.

[Garrè's osteomyelitis with bilateral mandible: a case report]

Garrès osteomyelitis is a specific type of chronic osteomyelitis that most commonly occurs in young patients, secondary to dental infection, and affects the unilateral side of the mandible. Bilateral mandibular Garrè's osteomyelitis is rare. In this article, a case of Garrè's osteomyelitis with bilateral mandible is reported. Its etiology, clinical pathologic features, diagnosis, differential diagnosis, and treatment methods are discussed by reviewing relevant literature.

Tuning response range of a transmission-based fiber-optic refractometer through LP₁₁ mode

A kind of sensing scheme is theoretically proposed to efficiently tune the response range of a fiber-optic refractometer based on the adiabatic transmission of the higher-order LP11 mode. Near the cut-off condition, transmission of the LP11 mode is a strong function of the refractive index (RI) under detection; thus high sensitivity is achieved. The cut-off RI value is dependent on the waist diameter; therefore the response RI range with high sensitivity can be changed just by altering the waist diameter. Theoretical calculations reveal that the response range is effectively tuned from 1.43-1.438 to 1.35-1.365 when the waist diameter is reduced from 2.5 to 1 μm. The proposed fiber-optic sensor is also superior when used as an absorbing sensor since the higher-order mode LP11 has a much larger power fraction in the evanescent field compared with the fundamental mode LP01 of the same fiber.

Euler force actuation mechanism for siphon valving in compact disk-like microfluidic chips

Based on the Euler force induced by the acceleration of compact disk (CD)-like microfluidic chip, this paper presents a novel actuation mechanism for siphon valving. At the preliminary stage of acceleration, the Euler force in the tangential direction of CD-like chip takes the primary place compared with the centrifugal force to function as the actuation of the flow, which fills the siphon and actuates the siphon valving. The Euler force actuation mechanism is demonstrated by the numerical solution of the phase-field based mathematical model for the flow in siphon valve. In addition, experimental validation is implemented in the polymethylmethacrylate-based CD-like microfluidic chip manufactured using CO2 laser engraving technique. To prove the application of the proposed Euler force actuation mechanism, whole blood separation and plasma extraction has been conducted using the Euler force actuated siphon valving. The newly introduced actuation mechanism overcomes the dependence on hydrophilic capillary filling of siphon by avoiding external manipulation or surface treatments of polymeric material. The sacrifice for highly integrated processing in pneumatic pumping technique is also prevented by excluding the volume-occupied compressed air chamber.

Silica nanospheres for filtering higher-order optical fiber modes

Tapered optical fibers (TOFs) modified by 400 nm-diameter silica nanospheres have been experimentally and theoretically investigated. Responses of the modified TOFs (MTOFs) to methylene blue (MB) solution and surrounding refractive index (RI) have been compared. The higher-order modes are effectively filtered by the silica nanospheres, which is visualized by the interferometric output spectrum of the MTOF. The higher-order mode filtering makes the MTOF respond to MB solution with reduced sensitivity, which endows the MTOF with the potential for distinguishing the RI property from the absorption property of the molecules under detection.

[Alcohol withdrawal syndrome associated with oral cancer operation: a case report]

Alcohol withdrawal syndrome (AWS) is a rare complication associated with oral cancer operation. This article reported a case of AWS after resection of squamous cell cancer of the right floor of mouth combined with radical neck dissection and trapezius myocutaneous flap reconstruction. The discussion included diagnosis, treatment and prevention of AWS.

[High resolution refractive index sensor based on the non-complete surface state of 1-D photonic crystal]

A novel refractive index sensor based on one-dimensional photonic crystal non-complete surface defect is introduced and the principle and the method of the sensor are discussed. The experiment system used to detect the refractive index was constructed to get high resolution and high Q-value. The sensor is verified by detecting the dimethyl sulphone solution. The experimental result indicates that this refractive index sensor's sensitivity is 3 025 nm x RIU(-1), and when the resolution of spectrometer is 0.01 nm the resolution of this sensor is 3.3 x 10(-6) RIU. The Q value of this sensor is 260, and the sensor has good linearity in 1.4-1.42 range (the linearity is 0.991 27). It was analyzed how the photonic crystal periodicity and liquid thickness affect the Q value of the sensor. The result proved that this kind of total reflection photonic crystal surface wave sensor is label free, which is similar with SPR sensor, and the sensor has high resolution, high Q-value and has real-time survey characteristic.

Derived vascular endothelial cells induced by mucoepidermoid carcinoma cells: 3-dimensional collagen matrix model

Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes, possibly due to proliferation of vascular endothelial cells (ECs) induced by mucoepidermoid carcinoma cells (MCCs) in their three-dimensional (3D) microenvironment. To date, no studies have dealt with tumor cells and vascular ECs from the same origin of mucoepidermoid carcinoma using the in vitro 3D microenvironment model. In this context, the current research aims to observe neovascularization with mucoepidermoid carcinoma microvascular ECs (MCMECs) conditioned by the microenvironment in the 3D collagen matrix model. We observed the growth of MCMECs purified by immunomagnetic beads and induced by MCCs, and characteristics of tubule-like structures (TLSs) formed by induced MCMECs or non-induced MCMECs. The assessment parameters involved the growth curve, the length, the outer and inner diameters, and the wall thickness of the TLSs, and the cell cycle. Results showed that MCCs induced formation of the TLSs in the 3D collagen matrix model. A statistically significant difference was noted regarding the count of TLSs between the control group and the induction group on the 4th day of culture (t=5.00, P=0.001). The outer and inner diameters (t(1)=5.549, P(1)=0.000; t(2)=10.663, P(2)=0.000) and lengths (t=18.035, P=0.000) of the TLSs in the induction group were statistically significant larger than those in the control group. The TLSs were formed at the earlier time in the induction group compared with the control group. It is concluded that MCCs promote growth and migration of MCMECs, and formation of the TLSs. The 3D collagen matrix model with MCMECs induced by MCCs in the current research may be a favorable choice for research on pro-angiogenic factors in progression of mucoepidermoid carcinoma.

[Study on the method of selecting Hadamard spectrophotometer's multi-slits]

In order to realize high throughput of Hadamard spectrometer, the performance of four Hadamard S slits are compared. Multi-micro-silicon slits were produced by MEMS technique. Based on diffraction theory, the formula with Hadamard S matrix is presented. The phenomenon of diffraction is analyzed by using the software of Matlab. The comparison was made between the Matlab simulating picture and the actual diffract picture of S slits on throughput. Experiment results indicate the precisions of the system. The influence of the factors such as spot distance, slit dimension and the matrix array on the throughput was analyzed, then the diffracting way of S slit was offered. The results of emulation are consistent with test, and proved that the design method on the slit in the paper is right. The way of analysis can provide some theoretic and application foundations for slit design.

The alteration of Id-1 and TSP-1 expression in mucoepidermoid carcinoma associated with its clinical features and prognosis

Expression of Id-1 (inhibitors of DNA binding/differentiation protein 1) and TSP-1 (thrombospondin-1) in mucoepidermoid carcinoma and their relationship to pathological features and prognosis was studied. Moderately and poorly differentiated groups had significantly higher Id-1 positive expression rate (p<0.05) than well differentiated carcinoma. Stages III-IV showed significant increase of Id-1 positive expression rate (p<0.05) compared with stages I and II. Id-1 positive expression was significantly higher in patients with cervical lymph node metastasis or relapse at 5 years (p<0.05). After that, patients with negative Id-1 expression had significantly higher tumor-free survival than patients with positive expression (p<0.05). Correlation between the expression of Id-1 and TSP-1 in mucoepidermoid carcinoma was negative (p<0.05). Poorly differentiated groups show significantly lower TSP-1 positive expression rate than well differentiated groups (p<0.05). No significant differences of TSP-1 positive expression were detected with clinical stage. TSP-1 positive expression was significantly lower in patients with cervical lymph node metastasis or relapse at 5 years (p<0.05). After 5 years, patients with positive TSP-1 expression had significantly higher tumor-free survival than patients with negative TSP-1. Positive Id-1 expression is associated with high malignancy/poor prognosis; positive TSP-1 expression is associated with low malignancy/good prognosis. Protein expression status may help assess tumor malignancy and patient prognosis.

[Expression and significance of basic fibroblast growth factor and transforming growth factor-beta 1 in mucoepidermoid carcinoma with different malignant degree]

OBJECTIVE

To study the expression and significance of basic fibroblast growth factor(bFGF)and transforming growth factor-beta 1 (TGF-beta1) in mucoepidermoid carcinomas with different malignant degree.

METHODS

Using immunohistochemistry (IHC) staining technique, bFGF and TGF-beta1 proteins in the mucoepidermoid carcinoma tissues with different malignant degree, including well-differentiated, moderately differentiated and poorly differentiated mucoepidermoid carcinoma, and normal salivary gland tissue were detected.

RESULTS

The positive rate of bFGF and TGF-beta1 in normal salivary glands were apparently lower than those in malignant mucoepidermoid carcinomas (P<0.05). The positive rate of bFGF in moderately and poorly differentiated mucoepidermoid carcinoma was higher than that in the well-differentiated carcinoma (P <0.05). However, the positive expression of bFGF showed no relationship between the moderately and poorly differentiated mucoepidermoid carcinomas. The positive rate of TGF-beta1 in moderately and poorly differentiated mucoepidermoid carcinomas was lower than that in the well-differentiated carcinoma (P<0.05). The positive expression of TGF-beta1 showed no relationship between the moderately and poorly differentiated mucoepidermoid carcinomas. The expression of bFGF and TGF-beta1 showed negative correlation (r=- 0.471, P=0.0003).

CONCLUSION

The expression of TGF-beta1 may inhibit the development of the mucoepidermoid carcinoma, contrariwise, the expression of bFGF may prompt the development of the mucoepidermoid carcinoma. The expression of bFGF and TGF-beta1 has a negative correlation.

[Facial multiple malignant proliferating tricholemmoma: a case report]

Malignant proliferating tricholemmoma is a very rare dermatic annexal tumor originated from outer root sheath cells. In this article, a case of facial multiple malignant proliferating tricholemmoma was reported, and its clinical pathologic features, differential diagnosis, treatment methods and histogenesis were discussed by reviewing relevant literatures.

Correlation between the expression of thrombospondin-1 and neovascularization in mucoepidermoid carcinoma

BACKGROUND

Researchers have recently demonstrated that thrombospondin-1 (TSP-1) has an important function in regulating neovascularization. Whether it inhibits or accelerates neovascularization, however, is still controversial. We found few reports about the correlation between TSP-1 and vascularization in mucoepidermoid carcinoma. In this research, the distribution and expression of TSP-1 in mucoepidermoid carcinoma were investigated. We also analyzed (1) the correlation between the expression of TSP-1 and microvessel density (MVD), as an indicator of neovascularization activity, and (2) the effect of TSP-1 on neovascularization and tumor growth in the subcutaneous xenotransplanted model of mucoepidermoid carcinoma.

METHOD

(1) The sites and intensity of expression of TSP-1 and the MVD were analyzed in 45 cases of mucoepidermoid carcinoma after surgery by the method of streptavidin-peroxidase (SP) immunohistochemistry; and (2) recombinant human thrombospondin-1 (rhTSP-1) was injected twice a week for five consecutive weeks around the tumor in the subcutaneous xenotransplanted tumor model of mucoepidermoid carcinoma in nude mice. Each week, the tumor size was measured, in order to draw the growth curve of the xenotransplanted tumor model of mucoepidermoid carcinoma, and MVD was measured.

RESULTS

(1) The positive expression of TSP-1 protein was 57.78% (26/45). Most positive staining for TSP-1 was found in the cytoplasm of the cancer cells, while some staining occurred in the extracellular matrix. The mean MVD in 45 cases of mucoepidermoid carcinoma was 58.17 +/- 19.77 per 100 visual fields. Tumors with a high expression of TSP-1 showed a low MVD value, and the TSP-1 immunocompetence and microvessel density showed a significant negative correlation (r(s) = -0.947, P < 0.001). (2) The xenotransplanted tumors with the injection doses of 1.25, 0.75 and 0.25 microg/ml respectively were 36.97%, 53.36% and 73.61% of the size of the control group ((451 +/- 92), (651 +/- 113), (898 +/- 86) and (1220 +/- 157) mm(3) respectively, F = 53.167, P < 0.001), and their weights were respectively 35.14%, 51.35% and 70.27% of the control group ((1.3 +/- 0.5), (1.9 +/- 0.5), (2.6 +/- 0.3), and (3.7 +/- 0.7) g respectively, F = 62.669, P < 0.001). Their MVDs were 25.00%, 45.93%, and 72.20% respectively of the control group and concentration dependent (15.43 +/- 3.45, 28.35 +/- 4.24, 44.57 +/- 3.35 and 61.73 +/- 5.43 per 100 visual fields respectively, F = 54.582, P < 0.001).

CONCLUSIONS

The TSP-1 has a higher expression in mucoepidermoid carcinoma and the expression has a significant negative correlation with neovascularization. The TSP-1 inhibits neovascularization and tumor growth, and it might be a new biological therapy for treatment of patients with mucoepidermoid carcinoma.

[Correlation between the expression of thrombospondin-1 and the angiogenesis in mucoepidermoid carcinoma]

OBJECTIVE

To study the relationship between the expression of thrombospondin-1 (TSP-1) and the angiogenesis in mucoepidermoid carcinoma.

METHODS

Immunohistochemistry were applied to detect the expression of TSP-1 and the value of microvessel density (MVD) in 45 mucoepidermoid carcinoma patients.

RESULTS

Positive expressions of TSP-1 protein were detected in 26 of the 45 (57. 78%) cases. Most positive staining for TSP-1 was observed in the cytoplasm of the cancer cells, some of those were in the extracellular matrix. The mean MVD in 45 cases with mucoepidermoid carcinoma was 60. 68 +/- 19.84 vessels per 100 field of vision. Tumors with a high expression of TSP-1 showed a low value of MVD and the correlation between TSP-1 immunocompetence and microvessel density was highly significant (r(s) = -0.942, P < 0.001).

CONCLUSION

The TSP-1 is expressed in most mucoepidermoid carcinoma and were associated with neovascularization. TSP-1 is likely to inhibit the extensive neovascularization and increased TSP-1 expression might inhibit angiogenic phenotype in mucoepidermoid carcinoma.

[The expression of inhibitor-1 of DNA binding/differentiation-1 and thrombospondin-1 in mucoepidermoid carcinoma of different malignant degree]

OBJECTIVE

To study the expression of inhibitor-1 of DNA binding/differentiation-1 (Id-1) and thrombospondin-1 (TSP-1) genes in mucoepidermoid carcinoma of different malignant degree and analyze the relationship between them.

METHODS

Using immunohistochemistry (IHC) staining technique, TSP-1 and Id-1 proteins in the mucoepidermoid carcinoma of different malignant degree, including well-differentiated, moderately differentiated and poorly differentiated mucoepidermoid carcinoma, and normal salivary gland tissues were detected.

RESULTS

The positive rate of Id-1 and TSP-1 in normal salivary glands were apparently lower than that in malignant mucoepidermoid carcinoma(P = 0.000, P = 0.013). The positive rate of Id-1 in moderately and poorly differentiated mucoepidermoid carcinoma was higher than that of the well-differentiated (P = 0.001, P = 0.002). However, the positive expression of Id-1 showed no relationship between the moderately and poorly differentiated mucoepidermoid carcinoma(P > 0.05). The positive rate of TSP-1 in poorly differentiated mucoepidermoid carcinoma was less than that of the well-differentiated(P = 0.014). The positive expression of TSP-1 showed no relationship between the moderately and poorly differentiated mucoepidermoid carcinoma(P > 0.05), and the positive expression of it also showed no relationship between the moderately and well differentiated mucoepidermoid carcinoma (P > 0.05). The expression of Id-1 and TSP-1 showed negative correlation(r = -0.394, P = 0.002).

CONCLUSION

The expression of TSP-1 may inhibit the development of the mucoepidermoid carcinoma, contrarily, the expression of Id-1 may prompt the development of the mucoepidermoid carcinoma. The expression of Id-1 and TSP-1 has negative correlation.

Odontogenic tumours: a retrospective study of 1642 cases in a Chinese population

A total of 1642 odontogenic tumour cases retrieved from the files of the College of Stomatology, Sichuan University, China were retrospectively analyzed for gender, age, tumour site and relative frequency of various types, and the data compared with that of previous reports. The final diagnosis in each case was based on the WHO 2005 histopathological classification of odontogenic tumours. Of these tumours 1592 (97.0%) were benign and 50 (3.0%) were malignant. Ameloblastoma (40.3%) was the most frequent type, followed by keratocystic odontogenic tumour (35.8%), odontoma (4.7%) and odontogenic myxoma (4.6%). The mean age of the patients was 32.1, with a wide range (3-84 years). The male-female ratio and maxilla-mandible ratio were 1.4:1 and 1:4.0, respectively. Ameloblastoma and keratocystic odontogenic tumours, important indications of extensive surgical procedures, are not considered rare in this Chinese population, whereas odontoma is uncommon.

[Analysis and test of piezoelectric micropump for drug delivery]

With a microsystem or micropump, the release rate of drug delivery is able to be controlled easily to maintain the therapeutic efficacy. A piezoelectric membrane-valve micropump for implantable and carryhome drug delivery system is developed and tested. The influence elements of dynamic performance of the PZT actuator and valve were analyzed, and the calculation method of resonant frequency of the membrane valve was provided. Study results showed that the output performance of the micropump depended on the coupling effect of the actuator and valve. For a given actuator, the output value and the optimal frequency of a micropump could be enhanced only by valve design. Two micropumps with different valve dimensions were fabricated for comparing examination. The smaller -valve micropump obtained higher output values (the maximum flow rate and backpressure being 3.5 ml/min and 27 KPa, respectively) and two optimal frequencies (800 Hz and 3 000 Hz). The larger -valve micropump achieved lower output values (the maximum flow rate and backpressure being 3.0 ml/min and 9 KPa, respectively) and one optimal frequency (about 200 Hz). The test results suggest that the output values and optimal frequency of micropump can be improved by changing the valve dimension, and the viewpoint that checkvalve micropump works only with low acting frequency is wrong.

Immunohistochemical co-localization of lymphatics and blood vessels in oral squamous cell carcinomas

BACKGROUND

Differentiating lymphatic vessels from blood vessels is difficult, partly due to the lack of a specific method for identifying lymphatics. A new lymphatic vessel-reactive antibody, D2-40 has recently become commercially available. We examined the selectivity of D2-40 for lymphatics in oral neoplastic lesions for discrimination from blood vessels.

METHODS

Formalin-fixed, paraffin-embedded sections of oral lymphangiomas (n = 3), oral hemangiomas (n = 7), and oral squamous cell carcinomas (OSCC, n = 46) were double immunostained with D2-40 and anti-CD34 monoclonal antibodies (MoAb) using ENVISION-polymer technique with 5-bromo-4-chloro-3-indoxyl-phosphate (BCIP)/nitroblue tetrazolium chloride (NBT) and 3,3'-diaminobenzidine (DAB) as color reagents, respectively.

RESULTS

In the oral lymphangiomas and hemangiomas D2-40 was detected in all lymphatics, while all blood vessels were positive for CD34. In OSCC, number of vessels for lymphatics (P < 0.01) and for blood vessels in the perineoplastic areas were significantly greater than those in intratumoral areas.

CONCLUSIONS

These results indicate that lymphatic proliferation might be much more extensive in the peritumoral area than intratumoral.

[The changes of bacteria group on oral mucosa after radiotherapy of postoperative patients of oral carcinoma]

OBJECTIVE

To investigate the microbial contents presented on the surface of mucosa in the oral cavity of patients who accepted radiotherapy, and to provide the evidences of controlling post-radiotherapeutic infections.

METHODS

32 patients (19 males and 13 females) aged from 37 - 72 received radiotherapy after oral squamous cell carcinomas operation were selected. Samples of saliva were obtained from the radiated center and opposite mucosa before and after radiotherapy. The detective amount, detective ratio and constituent ratio were analysed by cultivation and identification.

RESULTS

Streptococci, Candida albicans and Pseudomonas aeruginosa significantly increased on both sides of the oral mucosa while Neisseria and Actinobacillus decreased on radiated region after the radiotherapy.

CONCLUSION

Radiotherapy has great effects on oral bacteria and pathogenic organism may play a role in post-radiotherapy infections. It is necessary to do bacteria culture and choose sensitive antibiotics regularly for post-radiotherapeutic patients.

[Immunohistochemical findings on liver tissue in patients with hepatitis C]

OBJECTIVE

To investigate the distributions and infer relations of HCV antigens in the liver tissues.

METHODS

Immunohistochemical techniques as polyclonal antibody to HCV, monoclonal antibody to HCV - NS3 and monoclonal antibody to HCV - NS5 were used to detect HCV antigens in 107 patients with hepatitis C.

RESULTS

HCV antigens in liver tissues were identified on these three kinds of antibodies. The positive rates were 38.3%, 28.0% and 52.3% respectively. The positive granules were located in the cytoplasma of liver cells. The distributions of positive cells were scattered, diffusive and clustered. No obvious anatomic association was observed between the expression of HCV - NS3 and inflammatory reaction. HCV - NS5 positive cells were more commonly seen around or in the flammatory focci.

CONCLUSION

The expressions of various components of HCV were demonstrated in different concentrations. The expressions of HCV - NS5 might be related to the pathogenesis of hepatitis C.

[Pathologic changes of lymphatic capillaries after injection of U14 cells in rat tongue perineoplastic area]

OBJECTIVE

1. To establish a model of neck lymphatic metastasis of cancer by injecting tumor cells into the rat tongue; 2. To observe the relationship between pathologic changes of perineoplastic lymphatic in different stages of implanted tumor growth and lymphatic metastasis of tumor cells.

METHODS

60 Kunming rats with injection of 5 x 10(6) U14 tumor cells into each rat tongue were chosen and randomized into 6 groups. In every 5 days, specimens of rat tongues with implanted tumor and neck lymph nodes with possible metastatic tumor cells were removed from each group of rats. Cryosections of rat tongue were processed with a modified enzyme-histochemical staining technique, using 5'-nucleotidase with HE to demonstrate lymphatic capillaries. Attention was paid to pathologic change of lymphatic capillaries in perineoplastic area of rat tongue in different growth stages of implanted tumor. Routing wax sections of lymph nodes processed with HE staining were examined under light microscopy to determine whether there were any metastasis tumor cells.

RESULTS

1. Metastasis to neck lymph nodes could be observed 15 days later after injection of U14 tumor cells into rat tongue. The situation of metastasis of lymph nodes varied greatly from tumor cells in bundle within marginal sinus to complete occupation of lymph nodes by U14 cells. 2. Tumor cells penetrated the lymphatic capillary by passing singly or in clumps between endothelial cells or through some destroyed endothelia. A great number of lymphatic with dilated cavity was found nearby the tumor tissue which facilitated tumor cells to enter the lymphatic cavity. 3. There were much more amount of lymphatic capillaries with dilated cavity around tumor mass comparing with that of normal tongue of the control group rats, and the number of lymphatic capillaries with opening cavity tend to increase with growth of implanted tumor.

CONCLUSION

Direct and objective view of lymphatic capillaries can be obtained by means of the modified enzyme-histochemical staining technique, using 5'-nucleotidase with HE to demonstrate lymphatic capillaries; A great number of lymphatic capillaries with dented cavity in normal physical state are forced to be dilated during process of tumor growth, thus in turn increase the possibility for tumor cells to penetrate the lymphatic capillary by passing singly or in clumps between endothelial cells.

[Study of superinfection of HBV and HCV]

OBJECTIVES

To understand the situation in hepatitis B patients coinciding with HCV and to explore its influence on HCV on the replication of HBV.

METHODS

Using ELISA, 712 hepatitis B patients were tested for serum anti-HCV and markers of HBV.

RESULTS

Of the 712 patients, anti-HCV positive rate was 14.47% with the highest 48.98% in patients with severe hepatitis and the lowest 3.25% in patients with acute hepatitis. Markedly different anti-HCV positive rates (P < 0.001) in patients of different clinical stages were discovered. The more severe the case with longer the course, the higher the anti-HCV positive rates. In patients with superinfection of HBV and HCV, serum HBsAg, HBeAg and anti-HBcIgM positive rates were lower than those in patients with hepatitis B (P < 0.001, P < 0.001 and P < 0.05) but the anti-HBe positive rates were higher. All the differences showed an obvious statistical significance.

CONCLUSION

Hepatitis B coinciding with HCV infection is responsible for the deterioration of the disease and towards its formation of its chronic phase as well as for the inhibition of HBV replication.

[Study on hepatitis G virus infection]

OBJECTIVE

To find out the situation of HGV infection in Shandong Province, and to explore the relations between HGV infection and HCV or HBV infection.

METHODS

Enzyme linked immunosorbent assay (ELISA) was used to determine the serum anti-HGV in 1,082 patients with viral hepatitis, 77 patients with non A-E hepatitis and 361 blood donors.

RESULTS

53 patients whose serum anti-HGVs were positive (positive rate: 3.49%) were noticed. The anti-HGV positive rate (8.93%) in patients with Hepatitis C was remarkably higher than that (3.32%) in patients with Hepatitis B (chi 2 = 8.80, P < 0.01). The anti-HGV positive rate (4.82%) in patients with chronic hepatitis was significantly higher than that (0.79%) in patients with acute hepatitis (chi 2 = 10.79, P < 0.01). The anti-HGV positive rate (8.00%) in patients with severe hepatitis was obviously higher than that in patients with acute hepatitis (chi 2 = 10.23, P < 0.01).

CONCLUSION

The manifestations of HGV infection can be expressed as virus-carriers, subclinical infection or various clinical types. Patients with Hepatitis C were more subjective to be overlapped with HGV than the patients with Hepatitis B; moreover, HCV or HBV infection superinfected with HGV is associated with exacerbation of patients' condition and the formation of chronic infection.

Odontogenic tumors. A demographic study of 759 cases in a Chinese population

Seven hundred fifty-nine cases of odontogenic tumors retrieved from the files of College of Stomatology, West China University of Medical Sciences were classified according to the World Health Organization's Histological Classification of Odontogenic Tumors and compared with similar reports from other countries. Among these cases, 93.9% of the tumors were benign and 6.1% were malignant. Ameloblastomas predominated (58.6%) with a predilection for the mandible, while odontomas, generally regarded as the most frequent odontogenic tumor in North America, only accounted for 6.7%, the fourth most common tumor in this series. The mandible and the maxilla were divided into eight anatomic regions, and the distribution of each odontogenic tumor type amongst these regions was recorded. The relative incidence of each tumor type, patient age and gender were also compared with data from other selected large series. Geographic differences were noted in the relative incidence of ameloblastoma, odontoma and malignant odontogenic tumors among the Chinese/African, North American and Turkish/German groups. Ameloblastoma and malignant odontogenic tumors are not considered rare in a Chinese population.

[Study of HDV infection in Shandong province]

To understand the situation of HDV infection in Shandong province and to explore the relationship between HDV and HBV infections, 2681 samples infected with HBV were tested for serum anti-HDV with enzyme linked immunosorbent assay, in Shandong. Among them, 207 (7.72%) were found to be anti-HDV positive. Anti-HDV positive rates in HBsAg carriers and in hepatitis B patients were 3.16% and 13.15%, respectively. A significant difference (P < 0.001) was noticed between the two groups. In the second group, anti-HDV positive rates in patients with chronic active hepatitis and severe hepatitis were both higher than those in patients with acute hepatitis and chronic persistent hepatitis and the difference was significant (P < 0.001). The longer the history and the more severe the condition the higher of the anti-HDV positive rate was seen. The results indicated that the combined and over-lapping HDV infections were both responsible for the chronic status of hepatitis B and its deterioration.