[Comparison of the effects of total hip arthroplasty via direct anterior approach and posterolateral piriformis-sparing approach]

OBJECTIVE

To compare the clinical effects of direct anterior approach (DAA) and posterolateral piriformis-sparing approach (Mis-PLA) for minimally invasive surgery of total hip arthroplasty.

METHODS

The patients who had total hip arthroplasty from March 2015 to February 2016 were randomly divided into 2 groups: DAA group and Mis-PLA group. In the study, 43 patients (45 hips) were performed with total hip replacement via the direct anterior approach (DAA group). As comparison, 39 patients (42 hips) were performed with total hip replacement via the posterolateral piriformis-sparing approach (Mis-PLA group) at the same period. DAA group: 27 male patients (27 hips), and 16 female patients (18 hips), with an average age of (57.4±7.3) years, preoperative Harris score (41.4±8.7), body mass index (BMI) (24.3±2.2) kg/m²; Mis-PLA group: 25 male patients (26 hips), 14 female patients (16 hips), with an average age of (59.2±7.3) years, preoperative Harris score (39.6±8.4), BMI (24.7±2.5) kg/m². The length of incision, operation time, blood loss, postoperative Harris score were observed and specially the hip functional recovery was fully assessed.

RESULTS

(1) All the incisions healed by first intention. No complications were found in both groups. The length of incision:DAA group: (9.2±0.7) cm and Mis-PLA group: (9.5±0.6) cm. No statistical significant differences were found (P=0.053). The operation time:DAA group (74.3±10.1) min and Mis-PLA group (37.5±4.3) min, which showed statistically significant differences (P<0.01). Blood loss: DAA group (229.6±79.2) mL and Mis-PLA group (215.7±56.0) mL. No statistical significant differences were found (P=0.366). (2) The patients in both groups were followed up for 6-12 months. The Harris hip scores for 6 weeks' follow-up: (85.5±4.1) in DAA group and (79.0±4.4) in Mis-PLA group, which indicated statistically significant differences (P<0.01). The Harris scores for the 6-month follow-up: (94.3±2.7) in DAA group and (95.2±1.9) in Mis-PLA group. No statistically significant differences were found (P=0.125). The basic daily hip function analysis for the 6-week follow-up: walking speed: no statistically significant differences were found between the two groups (P=0.298); Climbing stairs: Mis-PLA group' outcome was better than DAA group's with statistical differences (P=0.047); Circling, sitting and wearing shoes and socks: outcomes in DAA group exceeded Mis-PLA group's with statistically significant differences (P<0.01, P=0.016, P<0.01).

CONCLUSION

Total hip arthroplasty through either DAA or Mis-PLA approaches could result in very satisfactory clinical effect. Comparing with DAA, Mis-PLA requires less operation time, shorter learning curve,which indicates that it is a relatively safer approach. The advantages of total hip arthroplasty through direct anterior approach lie in less positional limitation in the early stage of postoperative period, as well as a faster recovery of hip function.

[Paying attention to the protection of the function organ of submandibular gland]

Submandibular gland is an important human function organ. With the wide application of sialoendoscope and new understanding of IgG4 related sialadenitis, a lot of submandibular glands which were previously considered to be removed are preserved. However, some submandibular glands which might be preserved are still unfortunately sacrificed. Therefore, we advocate the popularization and promotion of new knowledge and techniques and should pay more attention to the protection of the function organ of submandibular gland.

[Surgical reconstruction of maxillary defects using a computer-assisted techniques]

The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate diagnosis and treatment of maxillary tumor; (2) Maxillary reconstruction with free fibula flap used computer assisted techniques; (3) Computer assisted orbital floor reconstruction after maxillectomy. The results suggested that computer assisted techniques could significantly improve the clinical outcome of maxillary reconstruction.

Endothelial Tight Junctions Are Opened in Cholinergic-Evoked Salivation In Vivo

Blood vessels provide the original supplies for the formation of primary saliva, which is regulated by the tight junctions (TJs) between endothelial cells. Previous studies have shown that blood flow increases with vasodilatation during cholinergic-evoked salivation. However, changes in vascular paracellular permeability and the role of endothelial TJs in salivation are unknown. Here, we established an in vivo paracellular permeability detection system and observed that the endothelial TJs were permeable to 4-kDa fluorescein isothiocyanate (FITC)-dextran while impermeable to 40- and 70-kDa FITC-dextran under an unstimulated condition in mouse submandibular glands (SMGs). Pilocarpine increased the flux of 4- and 40-kDa FITC-dextran out of blood vessels but did not affect 70-kDa FITC-dextran. Claudin 5, a TJ protein specifically localized in salivary endothelial cells, was redistributed from the apicolateral membranes to the lateral and basolateral membranes and cytoplasm in cholinergic-stimulated mouse SMGs and freshly cultured human SMG tissues. In the transplanted SMGs from epiphora patients, we found that claudin 5 was present in the basolateral membranes and cytoplasm, instead of the apical region in control SMGs. Moreover, the level of phospho-myosin light chain 2 increased within the blood vessels of the pilocarpine-stimulated mouse SMGs and transplanted human SMGs, while the downstream molecule F-actin was reorganized in the endothelial cells of the transplanted human SMGs. Taken together, our findings provide direct visual evidence that the opening of endothelial TJs and the redistribution of claudin 5 are essential events contributing to cholinergic-evoked salivation, thus enriching our understanding of the secretory mechanisms that link blood flow to primary saliva formation by regulating the endothelial paracellular permeability.

The Paradoxical Effects of Different Hepatitis C Viral Loads on Host DNA Damage and Repair Abilities

Hepatitis C virus (HCV)-induced hepatic stress is associated with increased oxidative DNA damage and has been implicated in hepatic inflammation. However, HCV infection and replication are uneven and vary among individual hepatocytes. To investigate the effect of the viral load on host DNA damage, we used an Enhanced Yellow Fluorescent Protein gene (EYFP)-tagged HCV virus to distinguish between HCV intracellular high viral load (HVL) cells and low viral load (LVL) cells. The cell sorting efficiency was confirmed by the high expression of the HCV polyprotein. We found DNA damage γ-H2AX foci in the HVL population. Comet assays demonstrated that HVL was related to the extent of the DNA strand breaks. Surprisingly, the DNA qPCR arrays and western blotting showed that the damage-related genes GPX2, MRE11, phospho-ATM, and OGG1 were significantly up-regulated in LVL cells but inversely down-regulated or consistently expressed in HVL cells. The colony survival assay to examine the repair abilities of these cells in response to irradiation showed that the LVL cells were more resistant to irradiation and had an increased ability to repair radiation-induced damage. This study found that intracellular viral loads drove cellular DNA damage levels but suppressed damage-related gene expression. However, the increase in damage-related gene expression in the LVL cells may be affected by ROS from the HVL cells. These findings provide new insights into the distinct DNA damage and repair responses resulting from different viral loads in HCV-infected cells.

Effects of Phenylephrine on Transplanted Submandibular Gland

Autotransplantation of the submandibular gland is a potential treatment for severe kerato-conjunctivitis sicca. However, one of the major barriers to this procedure is that secretions from the transplanted gland decrease shortly after the operation, which may lead to obstruction of Wharton’s duct, or even to transplantation failure. Using a rabbit model, we investigated whether phenylephrine could improve the secretion from the transplanted gland. We found that phenylephrine treatment significantly reversed the decrease in salivary secretion after transplantation, enhanced the expressions of α1A-, α1B-, and α1D-adrenoceptor mRNA, and ameliorated atrophy of acinar cells. Furthermore, phenylephrine also induced translocation of aquaporin-5 from the cytoplasm to the apical membrane, and increased the levels of phospho-ERK1/2, ERK1/2, phospho-PKCζ, and PKCζ in the transplanted gland. These results indicate that phenylephrine treatment moderates structural injury and improves secretory function in the transplanted submandibular gland through promoting α1-adrenoceptor expression and post-receptor signal transduction.

Functional α1-Adrenoceptor Subtypes in Human Submandibular Glands

α1-Adrenoceptor has been discovered to exist in many human tissues and mediates important physiological functions. The purpose of this study was to detect the expression, distribution, and function of α1-adrenoceptor subtypes in human submandibular glands. α1A- and α1B-Adrenoceptor mRNAs were identified by reverse-transcription/polymerase chain-reaction (RT-PCR), and their proteins were detected by Western blotting. No expression of the α1D-adrenoceptor mRNA and protein was found. By in situ hybridization and immunohistochemistry, α1A- and α1B-adrenoceptor mRNAs and proteins were shown to be widespread in both ductal and acinar cells. By confocal microscopy, phenylephrine (stimulating both α1A- and α1B-adrenoceptors) or A61603 (α1A-selective agonist) induced an increase in intracellular calcium by 2.33 ± 0.18-fold and 1.81 ± 0.43-fold, respectively, while 5-methylurapidil (α1A-selective antagonist) partly blocked calcium mobility stimulated by phenylephrine. The results indicated that functional α1A- and α1B-adrenoceptors were expressed in human submandibular glands, and might contribute to the regulation of saliva synthesis and secretion.

Bromomethylthioindole Inspired Carbazole Hybrids as Promising Class of Anti-MRSA Agents

Series of N-substituted carbazole analogues bearing an indole ring were synthesized as anti-methicillin-resistant Staphylococcus aureus (MRSA) agents from a molecular hybridization approach. The representative compound 19 showed an MIC = 1 μg/mL against a panel of MRSA clinical isolates as it possessed comparable in vitro activities to that of vancomycin. Moreover, compound 19 also exhibited MIC = 1 μg/mL activities against a recent identified Z172 MRSA strain (vancomycin-intermediate and daptomycin-nonsusceptible phenotype) and the vancomycin-resistant Enterococcus faecalis (VRE) strain. In a mouse model with lethal infection of MRSA (4N216), a 75% survival rate was observed after a single dose of compound 19 was intravenously administered at 20 mg/kg. In light of their equipotent activities against different MRSA isolates and VRE strain, the data underscore the importance of designed hybrid series for the development of new N-substituted carbazoles as potential anti-MRSA agents.

[Effect of autonomic denervation on the secretory function of submandibular glands]

Submandibular gland is innervated by sympathetic and parasympathetic nerves, both of which work synergistically to promote the salivation of the glands. However, denervation does not always produce an inhibitive effect. Regeneration secretion was put forward to describe the situation in which the glands after denervation were found to be supersensitive to the stimulation of several agonists of saliva secretion-related receptors. It is of clinical significance to get a good understanding of the secretory mechanism changes in the autonomically denervated submandibular gland. The present paper aims to review the studies on the denervation effects on the submandibular gland.

Mycotoxin Patulin Suppresses Innate Immune Responses by Mitochondrial Dysfunction and p62/Sequestosome-1-dependent Mitophagy

Innate immune responses are important for pathogen elimination and adaptive immune response activation. However, excess inflammation may contribute to immunopathology and disease progression (e.g. inflammation-associated hepatocellular carcinoma). Immune modulation resulting from pattern recognition receptor-induced responses is a potential strategy for controlling immunopathology and related diseases. This study demonstrates that the mycotoxin patulin suppresses Toll-like receptor- and RIG-I/MAVS-dependent cytokine production through GSH depletion, mitochondrial dysfunction, the activation of p62-associated mitophagy, and p62-TRAF6 interaction. Blockade of autophagy restored the immunosuppressive activity of patulin, and pharmacological activation of p62-dependent mitophagy directly reduced RIG-I-like receptor-dependent inflammatory cytokine production. These results demonstrated that p62-dependent mitophagy has an immunosuppressive role to innate immune response and might serve as a potential immunomodulatory target for inflammation-associated diseases.

Interleukin-17 Impairs Salivary Tight Junction Integrity in Sjögren's Syndrome

Sjögren's syndrome (SS) is an inflammatory autoimmune disease that causes secretory dysfunction of the salivary glands. It has been reported that proinflammatory cytokine interleukin-17 (IL-17) was elevated and tight junction (TJ) integrity disrupted in minor salivary glands from SS patients. However, whether the elevated IL-17 in SS affects TJ integrity and thereby alters the function of salivary gland is unknown. Here, by using nonobese diabetic (NOD) mice as SS model, we found that the stimulated salivary flow rate was significantly decreased in NOD mice. Lymphocyte infiltration was mainly observed in submandibular glands (SMGs), but not parotid glands (PGs), of NOD mice. IL-17 was significantly increased and mainly located in lymphocytic-infiltrating regions in SMGs but not detectable in PGs of NOD mice. Meanwhile, the epithelial barrier function was disrupted, as evidenced by an increased paracellular tracer clearance and an enlarged acinar TJ width in SMGs of NOD mice. Furthermore, claudin-1 and -3 were elevated especially at the basolateral membranes, whereas claudin-4, occludin, and zonula occludens-1 (ZO-1) were reduced in SMGs of NOD mice. Moreover, occludin and ZO-1 were dispersed into cytoplasm in SMGs of NOD mice. However, no change in the expression and distribution of TJ proteins was found in PGs. In vitro, IL-17 significantly decreased the levels and apical staining of claudin-4 and ZO-1 proteins in the cultured SMG tissues, as well as claudin-1, occludin, and ZO-1 in PG tissues. Moreover, IL-17 activated the phosphorylation of IκBα and p65 in SMG cells, whereas pretreatment with NF-κB inhibitor pyrrolidine dithiocarbamate suppressed the IL-17-induced downregulation of claudin-4 and ZO-1 in SMG tissues. Taken together, these findings indicate that IL-17 derived from infiltrating lymphocyte impairs the integrity of TJ barrier through NF-κB signaling pathway, and thus might contribute to salivary gland dysfunction in SS.

Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18)  cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43)  cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

New measurement of antineutrino oscillation with the full detector configuration at Daya Bay

We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×10^{5} GW_{th}  ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six ^{241}Am-^{13}C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin^{2}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3}  eV^{2} in the three-neutrino framework.

Communication: Tracking molecular structure deformation and relaxation in real time

The CH3I structural deformation induced by strong laser fields is revealed by time- and frequency-resolved ro-vibrational spectra. The experimental results show that the CH3I molecule undergoes ultrafast structural deformation of CH3 "umbrella-closing" induced by the strong fs laser field (more than 10(11) W/cm(2)) and followed by a structural relaxation of "umbrella-opening" within an exponential decay time scale of ∼620 fs. This study provides a first glimpse of the immense potential of the time- and frequency-resolved vibrational spectra in studying molecular deformation dynamics.

Pre- and Post-synaptic Effects of Botulinum Toxin A on Submandibular Glands

Intraglandular injection of botulinum toxin type A (BoNT/A) is an effective treatment for sialorrhea. Despite numerous experimental and clinical studies on inhibition of saliva section by BoNT/A, the proteolysis of synaptosomal-associated protein 25 (SNAP-25) following BoNT/A treatment has not yet been confirmed in the salivary gland after injection of BoNT/A. More important, it is not known whether BoNT/A exerts a direct effect in acinar cells. Here, we show that injection of BoNT/A into the rat submandibular gland (SMG) decreased salivary flow in a dose-dependent manner; the inhibitory effect lasted at least 4 wk, and salivary flow recovered to normal levels by 12 wk. During the inhibitory period, SMG neurons and synapses expressed lower levels of full-length SNAP-25, and cleavage of SNAP-25 was observed, as indicated by detection of reduced molecular weight SNAP-25 using Western blotting. In addition, the water channel aquaporin 5 (AQP5) was downregulated and abnormally distributed in rat SMG after injection of BoNT/A. The direct effects of BoNT/A on AQP5 expression and distribution were assessed in vitro to exclude the influence of BoNT/A-induced inhibitory neurotransmission. In stable GFP-AQP5-transfected SMG-C6 cells, treatment with BoNT/A reduced the cell surface protein level of AQP5 in a dose- and time-dependent manner without affecting total AQP5 protein expression. Cell surface biotinylation and immunofluorescence demonstrated translocation of AQP5 from the membrane to the cytoplasm, which was confirmed by decreased levels of AQP5 protein in the membrane fraction and increased levels in the cytoplasmic fraction, suggestive of AQP5 redistribution. Taken together, these results indicated that BoNT/A reversibly decreased saliva secretion in rat SMGs through not only the presynaptic SNAP-25 cleavage but also the postsynaptic AQP5 redistribution. These data provide the first evidence for a direct effect of BoNT/A on the salivary gland.

[Expression characteristics of epithelial markers in human embryonic stem cells differentiating into keratinocytes]

OBJECTIVE

To differentiate human embryonic stem cells (hESCs) into keratinocytes (K-hESCs) and analyse the expression characteristics of biomarkers of K-hESCs.

METHODS

The hESCs of line H9 were seeded on matrigel in mTeSR1 medium. The hESCs were directly differentiated into keratinocytes in epithelial differentiation medium with bone morphogenetic protein 4, retinoic acid and N2 supplement. The karyotype of K-hESCs was analyzed, comparing the gene expression differences of K-hESCs with human gingival epithelial cells (HGECs), human immortalized oral epithelial cells (HIOECs) and HaCaT by Real-time PCR. Molecular characteristics of the cell differentiation were observed throughout the process by immunocytochemical techniques.

RESULTS

H9-hESCs were successfully differentiated into the cells that exhibited characteristics of keratinocytes in epithelial differentiation medium. The karyotype of K-hESCs was 46, XX; and the keratinocyte gene p63 expression in K-hESCs was significantly lower than that in HaCaT (P < 0.05), but there was no significant difference of p63 expression in K-hESCs, comparing with that in HGECs and HIOECs (P > 0.05).

CONCLUSION

H9-hESCs could be directly differentiated into K-hESCs. The gene expression of K-hESCs was similar to that of epithelial cells in the early stage of monolayer cells differentiation with high proliferative activity.

Reconstruction of maxillary defects with free fibula flap assisted by computer techniques

OBJECTIVE

Free fibula flaps are widely used for maxillary reconstruction. The three-dimensional position of the fibula flap is very difficult to control in conventional operations based solely on the surgeon's experience. We aimed to improve this surgery by using computerized techniques.

METHODS

Twenty-seven patients with maxillary tumors underwent maxillectomy and free fibula flap reconstruction in our department between 2011 and 2013. Virtual planning and surgical navigation were used for eight patients, and conventional surgery was performed in 19 patients. The three-dimensional fibular positions were evaluated in the two groups. Differences between the postoperative position of the fibular segments and the virtual plans were evaluated in the computer-assisted surgery group.

RESULTS

The three-dimensional position of the fibula flap in the computer-assisted surgery group, including the vertical distance (p = 0.013), horizontal position (p = 0.019) and extension of the posterior end (p = 0.041), was significantly more accurate and nearer to the ideal position than that in the conventional surgery group. The average difference between the actual postoperative position of the fibular segments and the virtual plan in the computer-assisted surgery group was <5 mm.

CONCLUSION

Application of computer-assisted techniques such as virtual planning and surgical navigation significantly improve the clinical outcomes of maxillary reconstruction with free fibula flaps.

Search for a light sterile neutrino at Daya Bay

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

TLR7/8 agonists activate a mild immune response in rabbits through TLR8 but not TLR7

Toll-like receptors 7 (TLR7) and 8 (TLR8) recognize viral single-stranded RNA and small molecular weight agonists to activate anti-viral immune responses. TLR8s from different species have distinct ligand recognitions. For example, human TLR8 is responsive to ligand stimulation, but mouse and rat TLR8 are activated by small molecular weight agonists only in the presence of polyT-oligodeoxynucleotides. TLR7 and TLR8 have been reported to be absent and pseudogenized, respectively, in rabbit (Oryctolagus cuniculus). In this study, we detected the expression of rabbit (rab)TLR8 in immune-cell-associated tissues. Cell proliferation and cytokine expressions in rabbit splenocytes were induced by the TLR7/8 ligand but not by the TLR7 ligands, suggesting that rabTLR8 is functional but rabTLR7 is not. In rabbits, CL075, a TLR7/8 ligand, activated an antigen-specific antibody response, although one not as potent as aluminum salt or Freund's adjuvant. Nevertheless, CL075, alone or in combination with aluminum salt, generates fewer adverse effects than Freund's adjuvant at the injection sites. To further investigate the activation of rabTLR8, we cloned its cDNA. In cell-based assay, this rabTLR8 is activated by TLR7/8 ligand but not activated by TLR7 ligand. Upon stimulation the rabTLR8 had a lower activation compared to the activation of TLR8 from other species, except the mouse and rat TLR8s. Using different deletion and human-rabbit chimeric TLR8 expressing constructs, we showed that an extra peptide in the undefined region results in reduced activity of rabTLR8. These results provide a molecular basis for the mild activities of TLR7/8 ligands in rabbits, and suggest TLR7/8 agonists may provide safer immune stimuli in rabbits than in other non-rodent species.

Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

The inducible nitric-oxide synthase (iNOS)/Src axis mediates Toll-like receptor 3 tyrosine 759 phosphorylation and enhances its signal transduction, leading to interferon-β synthesis in macrophages

Double-stranded RNA (dsRNA) induces phosphorylation of Toll-like receptor 3 (TLR3) at tyrosine 759 and subsequently triggers signaling pathways to promote interferon-β (IFN-β) production. In this study, we found that dsRNA stimulation induces biphasic TLR3 Tyr-759 phosphorylation in macrophages. In addition to the immediate TLR3 Tyr-759 phosphorylation, we identified a second wave of Tyr-759 phosphorylation accompanied by an increase of both Src and ifn-β transcription in the later phase of dsRNA stimulation. Interestingly, Src phosphorylated TLR3 Tyr-759 in vitro and in vivo. However, knockdown of Src abolished the late phase of TLR3 Tyr-759 phosphorylation and decreased the nuclear accumulation of interferon regulatory factors 3 and 7 (IRF3 and -7) and IFN-β production. Reintroduction of Src restored all of these molecular changes. Notably, via down-regulation of Src, dsRNA-elicited TLR3 Tyr-759 phosphorylation, the nuclear accumulation of IRF3/IRF7, and IFN-β generation were inhibited in inducible nitric-oxide synthase (iNOS)-null macrophages. TLR3 knockdown destabilized Src and reduced the nuclear level of IRF3/IRF7 and IFN-β production in macrophages exposed to LPS (a TLR4 ligand known to induce Src and IFN-β expression). Ectopic expression of wild type TLR3, but not its 759-phenylalanine mutant, restored Src activity and ifn-β transcription. Taken together, these results suggested an essential role of the iNOS/Src/TLR3 axis in IFN-β production in macrophages.

Hypersensitive mAChRs are involved in the epiphora of transplanted glands

Autologous transplantation of the submandibular gland is an effective treatment for severe dry eye syndrome. However, more than 40% of patients experience epiphora 3 to 6 months after transplantation. The underlying mechanism of epiphora remains to be elucidated. To investigate the potential roles of muscarinic acetylcholine receptors (mAChRs) in the induction of epiphora in transplanted glands, we assessed and found elevated mRNA and protein expression of M1- and M3-mAChR in transplanted glands from epiphora patients. The content of inositol 1, 4, 5-trisphosphate was also elevated. Moreover, carbachol (5 and 10 µM) induced greater increase of [Ca(2+)]i in isolated epiphora submandibular cells than in controls. Although aquaporin-5 (AQP5) content and distribution in the apical and lateral plasma of epiphora glands did not change, AQP5 content was reduced in lipid microdomains (lipid rafts and caveolae) but increased in non-lipid microdomains compared with controls. Carbachol (10 µM) increased the ratio of non-lipid microdomain to total AQP5 in the cultured control submandibular gland tissue. Taken together, these results indicated that hypersensitive mAChRs might be involved in the epiphora of transplanted submandibular glands by modulating AQP5 trafficking.

Clinicopathological study of distant metastases of salivary adenoid cystic carcinoma

Most studies of the clinicopathological characteristics and prognosis of patients with distant metastasis of salivary adenoid cystic carcinoma (SACC) have used small patient samples. To further explore this issue, a descriptive and prognostic study of 467 patients with SACC who were treated from 1963 to 2009 was conducted at a single institution. One hundred and forty-five patients (31.0%) had distant metastases. At least 20% of patients who presented with the early-stage disease and no recurrence developed distant metastasis. The overall 5-, 10-, and 20-year survival rates were 85.6%, 67.4%, and 50.4%, respectively, for patients without distant metastasis, and 69.1%, 45.7%, and 14.3%, respectively, for patients with distant metastasis. The median survival time after distant metastasis was 36 months (range 1-112 months). The prognosis was similar between patients who received treatment for metastasis and those who did not. Patients who were diagnosed with early-stage disease and without local recurrence of the primary tumours could also develop distant metastases. The biological characteristics of adenoid cystic carcinoma were different from those of squamous cell carcinoma. At present, the effectiveness of treatment for distant metastases is not ideal and further research is needed.

Lymphotoxin signaling is initiated by the viral polymerase in HCV-linked tumorigenesis

Exposure to hepatitis C virus (HCV) typically results in chronic infection that leads to progressive liver disease ranging from mild inflammation to severe fibrosis and cirrhosis as well as primary liver cancer. HCV triggers innate immune signaling within the infected hepatocyte, a first step in mounting of the adaptive response against HCV infection. Persistent inflammation is strongly associated with liver tumorigenesis. The goal of our work was to investigate the initiation of the inflammatory processes triggered by HCV viral proteins in their host cell and their possible link with HCV-related liver cancer. We report a dramatic upregulation of the lymphotoxin signaling pathway and more specifically of lymphotoxin-β in tumors of the FL-N/35 HCV-transgenic mice. Lymphotoxin expression is accompanied by activation of NF-κB, neosynthesis of chemokines and intra-tumoral recruitment of mononuclear cells. Spectacularly, IKKβ inactivation in FL-N/35 mice drastically reduces tumor incidence. Activation of lymphotoxin-β pathway can be reproduced in several cellular models, including the full length replicon and HCV-infected primary human hepatocytes. We have identified NS5B, the HCV RNA dependent RNA polymerase, as the viral protein responsible for this phenotype and shown that pharmacological inhibition of its activity alleviates activation of the pro-inflammatory pathway. These results open new perspectives in understanding the inflammatory mechanisms linked to HCV infection and tumorigenesis.

Hepatitis C affects nearly 200 million people worldwide. It results from the failure of the immune system to control the hepatitis C virus (HCV) replication and spread, leading to progressive liver disease that can culminate in fibrosis, cirrhosis and cancer. The inflammatory cells that infiltrate the diseased liver functionally contribute to fibrotic disease and cancer development by the release of potent soluble mediators that regulate cell survival and proliferation, angiogenesis, tissue remodelling, metabolism and genomic integrity. The goal of our work was to study the mechanisms of the initiation of the inflammatory process linked to HCV infection. We have shown that the presence of a single viral protein, namely NS5B, the RNA dependent RNA polymerase, promotes pro-inflammatory signaling. Moreover, inhibition of this pathway in HCV transgenic mice fully protects the animals from HCV-linked liver cancer. Our study contributes to a better understanding of the inflammatory mechanisms linked to HCV infection and thereby to tumorigenesis.

Adenoma-linked barrier defects and microbial products drive IL-23/IL-17-mediated tumour growth

Approximately 2% of colorectal cancer is linked to pre-existing inflammation known as colitis-associated cancer, but most develops in patients without underlying inflammatory bowel disease. Colorectal cancer often follows a genetic pathway whereby loss of the adenomatous polyposis coli (APC) tumour suppressor and activation of β-catenin are followed by mutations in K-Ras, PIK3CA and TP53, as the tumour emerges and progresses. Curiously, however, 'inflammatory signature' genes characteristic of colitis-associated cancer are also upregulated in colorectal cancer. Further, like most solid tumours, colorectal cancer exhibits immune/inflammatory infiltrates, referred to as 'tumour-elicited inflammation'. Although infiltrating CD4(+) T(H)1 cells and CD8(+) cytotoxic T cells constitute a positive prognostic sign in colorectal cancer, myeloid cells and T-helper interleukin (IL)-17-producing (T(H)17) cells promote tumorigenesis, and a 'T(H)17 expression signature' in stage I/II colorectal cancer is associated with a drastic decrease in disease-free survival. Despite its pathogenic importance, the mechanisms responsible for the appearance of tumour-elicited inflammation are poorly understood. Many epithelial cancers develop proximally to microbial communities, which are physically separated from immune cells by an epithelial barrier. We investigated mechanisms responsible for tumour-elicited inflammation in a mouse model of colorectal tumorigenesis, which, like human colorectal cancer, exhibits upregulation of IL-23 and IL-17. Here we show that IL-23 signalling promotes tumour growth and progression, and development of a tumoural IL-17 response. IL-23 is mainly produced by tumour-associated myeloid cells that are likely to be activated by microbial products, which penetrate the tumours but not adjacent tissue. Both early and late colorectal neoplasms exhibit defective expression of several barrier proteins. We propose that barrier deterioration induced by colorectal-cancer-initiating genetic lesions results in adenoma invasion by microbial products that trigger tumour-elicited inflammation, which in turn drives tumour growth.

Hepatic expression of HCV RNA-dependent RNA polymerase triggers innate immune signaling and cytokine production

Innate immunity controls pathogen replication and spread. Yet, certain pathogens, such as Hepatitis C Virus (HCV), escape immune elimination and establish persistent infections that promote chronic inflammation and related diseases. Whereas HCV regulatory proteins that attenuate antiviral responses are known, those that promote inflammation and liver injury remain to be identified. Here, we show that transient expression of HCV RNA-dependent RNA polymerase (RdRp), NS5B, in mouse liver and human hepatocytes results in production of small RNA species that activate innate immune signaling via TBK1-IRF3 and NF-κB and induce cytokine production, including type I interferons (IFN) and IL-6. NS5B-expression also results in liver damage.

Activation of transient receptor potential vanilloid subtype 1 increases secretion of the hypofunctional, transplanted submandibular gland

Hyposecretion occurs in most patients early after submandibular gland autotransplantation for severe keratoconjunctivitis sicca. Endogenous transient receptor potential vanilloid subtype 1 (TRPV1) has been recently demonstrated in rabbit submandibular glands, and activation of TRPV1 by capsaicin increases secretion in isolated glands, but the TRPV1-mediated secretory mechanism remains to be elucidated. The purpose of this study was to verify whether activation of TRPV1 by capsaicin could improve the secretion of transplanted gland and its underlying mechanism. The salivary flow of the transplanted glands was significantly decreased, and the mRNA and protein levels of TRPV1 and aquaporin 5 (AQP5) were downregulated in the transplanted glands. Topical capsaicin cream increased secretion and upregulated levels of TRPV1 and AQP5 in transplanted glands. Moreover, in cultured submandibular gland cells, capsaicin increased the mRNA expression of AQP5 and led to redistribution of AQP5 from the cytoplasm to the plasma membrane via TRPV1 activation. Capsaicin enhanced the phosphorylation of extracellular signal-regulated kinase (ERK). Preincubation of cells with PD98059, an inhibitor of ERK kinase, suppressed the capsaicin-induced mRNA expression of AQP5. In summary, the capsaicin-induced secretory mechanism involved activation of TRPV1 and upregulation of AQP5 in an ERK-dependent manner and promoted the redistribution of AQP5 in submandibular gland cells. Activation of TRPV1 may provide a new therapeutic strategy to improve submandibular gland hypofunction.

Hepatocyte IKKbeta/NF-kappaB inhibits tumor promotion and progression by preventing oxidative stress-driven STAT3 activation

The NF-kappaB activating kinase IKKbeta suppresses early chemically induced liver tumorigenesis by inhibiting hepatocyte death and compensatory proliferation. To study IKKbeta's role in late tumor promotion and progression, we developed a transplant system that allows initiated mouse hepatocytes to form hepatocellular carcinomas (HCC) in host liver after a long latency. Deletion of IKKbeta long after initiation accelerated HCC development and enhanced proliferation of tumor initiating cells. These effects of IKKbeta/NF-kappaB were cell autonomous and correlated with increased accumulation of reactive oxygen species that led to JNK and STAT3 activation. Hepatocyte-specific STAT3 ablation prevented HCC development. The negative crosstalk between NF-kappaB and STAT3, which is also evident in human HCC, is a critical regulator of liver cancer development and progression.

Dietary and genetic obesity promote liver inflammation and tumorigenesis by enhancing IL-6 and TNF expression

Epidemiological studies indicate that overweight and obesity are associated with increased cancer risk. To study how obesity augments cancer risk and development, we focused on hepatocellular carcinoma (HCC), the common form of liver cancer whose occurrence and progression are the most strongly affected by obesity among all cancers. We now demonstrate that either dietary or genetic obesity is a potent bona fide liver tumor promoter in mice. Obesity-promoted HCC development was dependent on enhanced production of the tumor-promoting cytokines IL-6 and TNF, which cause hepatic inflammation and activation of the oncogenic transcription factor STAT3. The chronic inflammatory response caused by obesity and enhanced production of IL-6 and TNF may also increase the risk of other cancers.

Monocytes transduced with lentiviral vectors expressing hepatitis C virus non-structural proteins and differentiated into dendritic cells stimulate multi-antigenic CD8(+) T cell responses

Halting the spread of hepatitis C virus (HCV) and also eradicating HCV in subjects with chronic infection are major goals for global health. To this end, several years of research on HCV vaccine development have led to the conclusion that multi-antigenic and multi-functional vaccine types are necessary for effectiveness against HCV infection. In this study, we evaluated lentiviral vectors (LV) expressing clusters of HCV structural (LV-HCV-S) and non-structural (LV-HCV-NS) genes for future vaccine development. Batches of high titer LV were used to transduce differentiated dendritic cells (DC) and monocytes. We report successful delivery of HCV gene clusters, particularly into monocytes, leading to >80% LV-HCV-NS and >70% LV-HCV-S and transduced cells, respectively. Intracellular expression of HCV proteins in monocyte-derived DC resulted in immunophenotypic changes, such as downregulation of CD83 and CD86. Monocytes expressing NS proteins and differentiated into DC stimulated allogeneic and autologous CD8(+) and CD4(+) T cells in vitro and resulted in antigen-specific CD8(+) T cell responses against NS3, NS4a and NS5b. Hence, lentiviral-mediated expression of the multi-antigenic HCV-NS cluster in monocytes subsequently differentiated into DC is a novel potential anti-HCV vaccine modality.

Isoproterenol improves secretion of transplanted submandibular glands

Autotransplantation of the submandibular gland is effective for severe keratoconjunctivitis sicca. However, most transplants show decreased secretion shortly after the operation, which leads to obstruction of Wharton's duct. The hypothesis that decreased catecholamine release due to denervation contributes to hypofunction in the early phase was tested in transplanted glands in rabbits. We found that salivary flow, expression of beta(1)- and beta(2)-adrenoceptor, and the maximum binding capacity were markedly decreased in the transplanted glands. Isoproterenol significantly reversed the decreased secretion, enhanced the expressions of beta(1)- and beta(2)-adrenoceptor, and ameliorated the atrophy of acinar cells. The contents of cAMP and phospho-ERK 1/2 were increased after isoproterenol treatment. These results indicate that lack of beta-adrenoceptor stimulation is involved in early dysfunction of the transplanted gland. Isoproterenol treatment moderates structural injury and improves secretory function in the transplanted submandibular gland through up-regulating beta(1)- and beta(2)-adrenoceptor expression and post-receptor signal transduction.

IL-6 and Stat3 are required for survival of intestinal epithelial cells and development of colitis-associated cancer

Colitis-associated cancer (CAC) is the most serious complication of inflammatory bowel disease. Proinflammatory cytokines have been suggested to regulate preneoplastic growth during CAC tumorigenesis. Interleukin 6 (IL-6) is a multifunctional NF-kappaB-regulated cytokine that acts on epithelial and immune cells. Using genetic tools, we now demonstrate that IL-6 is a critical tumor promoter during early CAC tumorigenesis. In addition to enhancing proliferation of tumor-initiating cells, IL-6 produced by lamina propria myeloid cells protects normal and premalignant intestinal epithelial cells (IECs) from apoptosis. The proliferative and survival effects of IL-6 are largely mediated by the transcription factor Stat3, whose IEC-specific ablation has profound impact on CAC tumorigenesis. Thus, the NF-kappaB-IL-6-Stat3 cascade is an important regulator of the proliferation and survival of tumor-initiating IECs.

125I seed implant brachytherapy-assisted surgery with preservation of the facial nerve for treatment of malignant parotid gland tumors

The surgical treatment of malignant parotid gland tumors combined with (125)I seed implant brachytherapy and preservation of the facial nerve is described. Tumor and parotid gland resection with preservation of the facial nerve was carried out in 12 patients with malignant parotid gland tumors. (125)I seeds were implanted into the target area intra- or postoperatively. The extent of regional control of the tumor was followed up, and facial nerve function was evaluated. None of the patients had tumor recurrence during the follow-up period of 50-74 months (median follow-up period, 66 months). Facial nerve function had recovered to normal by 6 months postoperatively in all patients. A limited surgical resection combined with (125)I seed implant brachytherapy is therefore considered to be an alternative treatment for local control of malignant parotid gland tumors with preservation of the facial nerve.

Hepatocyte necrosis induced by oxidative stress and IL-1 alpha release mediate carcinogen-induced compensatory proliferation and liver tumorigenesis

Hepatocyte I kappaB kinase beta (IKK beta) inhibits hepatocarcinogenesis by suppressing accumulation of reactive oxygen species (ROS) and liver damage, whereas JNK1 activation promotes ROS accumulation, liver damage, and carcinogenesis. We examined whether hepatocyte p38 alpha, found to inhibit liver carcinogenesis, acts similarly to IKK beta in control of ROS metabolism and cell death. Hepatocyte-specific p38 alpha ablation enhanced ROS accumulation and liver damage, which were prevented upon administration of an antioxidant. In addition to elevated ROS accumulation, hepatocyte death, augmented by loss of either IKK beta or p38 alpha, was associated with release of IL-1 alpha. Inhibition of IL-1 alpha action or ablation of its receptor inhibited carcinogen-induced compensatory proliferation and liver tumorigenesis. IL-1 alpha release by necrotic hepatocytes is therefore an important mediator of liver tumorigenesis.

Palmitoylation and polymerization of hepatitis C virus NS4B protein

Hepatitis C Virus (HCV) NS4B protein induces a specialized membrane structure which may serve as the replication platform for HCV RNA replication. In the present study, we demonstrated that NS4B has lipid modifications (palmitoylation) on two cysteine residues (cysteines 257 and 261) at the C-terminal end. Site-specific mutagenesis of these cysteine residues on individual NS4B proteins and on an HCV subgenomic replicon showed that the lipid modifications, particularly of Cys261, are important for protein-protein interaction in the formation of the HCV RNA replication complex. We further demonstrated that NS4B can undergo polymerization. The main polymerization determinants were mapped in the N-terminal cytosolic domain of NS4B protein; however, the lipid modifications on the C terminus also facilitate the polymerization process. The lipid modification and the polymerization activity could be two properties of NS4B important for its induction of the specialized membrane structure involved in viral RNA replication.

The ubiquitin-proteasome system facilitates the transfer of murine coronavirus from endosome to cytoplasm during virus entry

The ubiquitin-proteasome system is involved in cellular endocytosis and maturation of some viruses. In this study, we found that proteasome inhibitors blocked mouse hepatitis virus replication at an early step in the viral life cycle. In the presence of MG132, the entering viruses accumulated in both the endosome and denser lysosome, suggesting that the ubiquitin-proteasome system is involved in the release of virus from the endosome to the cytosol during the virus entry step.

Microvascular autologous submandibular gland transfer in severe cases of keratoconjunctivitis sicca

The objective is to evaluate the technique of microvascular autologous submandibular gland transfer for the treatment of severe keratoconjunctivitis sicca. From August 1999 to April 2002, 38 patients with severe keratoconjunctivitis sicca were treated by autologous submandibular gland transfer to the temporal region of the skull. The related vessels were anastomosed to the superficial temporal artery and vein. When the vein was too small, venous bridging was applied. Prior to cutting off the gland, the facial artery was preserved and infused with heparin in normal saline after the gland had been freed to allow inspection of the blood oozing from the three veins. This would be helpful in the selection of a relevant vein for anastomosis. Wharton's duct was transplanted to the upper lateral conjunctiva fornix, and the gland was left denervated. Postoperative scintigraphy with Tc99m pertechnetate, follow-up studies, and management of complications were performed. The transplantations were successful in 33 cases, their symptoms of xerophthalmia disappeared. The discomfort resulting from bright light and wind was also relieved. These patients could stop applying artificial tears. In five patients the transplanted glands did not survive. Epiphora occurred in eight cases. They were successfully treated by reducing the size of the graft. Obliteration of Wharton's duct took place in two cases and was treated by the reconstruction of the duct or duct orifice. Microvascular autologous submandibular gland transfer is a lasting and effective solution for severe cases of keratoconjunctivitis sicca.

Multiple type A/B heterogeneous nuclear ribonucleoproteins (hnRNPs) can replace hnRNP A1 in mouse hepatitis virus RNA synthesis

Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 has previously been shown to bind mouse hepatitis virus (MHV) RNA at the 3' end of both plus and minus strands and modulate MHV RNA synthesis. However, a mouse erythroleukemia cell line, CB3, does not express hnRNP A1 but still supports MHV replication, suggesting that alternative proteins can replace hnRNP A1 in cellular functions and viral infection. In this study, we set out to identify these proteins. UV cross-linking experiments revealed that several CB3 cellular proteins similar in size to hnRNP A1 interacted with the MHV RNA. These proteins were purified by RNA affinity column with biotinylated negative-strand MHV leader RNA and identified by mass spectrometry to be hnRNP A2/B1, hnRNP A/B, and hnRNP A3, all of which belong to the type A/B hnRNPs. All of these proteins contain amino acid sequences with strong similarity to the RNA-binding domains of hnRNP A1. Some of these hnRNPs have previously been shown to replace hnRNP A1 in regulating RNA splicing. These proteins displayed MHV RNA-binding affinity and specificity similar to those of hnRNP A1. hnRNP A2/B1, which is predominantly localized to the nucleus and shuttles between the nucleus and the cytoplasm, was shown to relocalize to the cytoplasm in MHV-infected CB3 cells. Furthermore, overexpression of hnRNP A/B in cells enhanced MHV RNA synthesis. Our findings demonstrate that the functions of hnRNP A1 in MHV RNA synthesis can be replaced by other closely related hnRNPs, further supporting the roles of cellular proteins in MHV RNA synthesis.

Diagnosis and treatment of epithelial salivary gland tumours in children and adolescents

In a series of 2,871 epithelial salivary gland neoplasms managed in the Peking University School of Stomatology between 1974 and 1999, 86 arose in children <16 years of age (52 parotid, 12 submandibular gland, 2 sublingual gland, and 20 minor salivary gland). Considerable delay was encountered in diagnosis (benign 24 months and malignant 16 months). In this group of children, 46 tumours (53%) proved to be malignant, with an incidence in the parotid, submandibular, sublingual, and minor salivary glands of 31/52 (60%), 2/12, 0/2, and 13/20 (65%), respectively. Sixty-six of 86 neoplasms (77%) occurred in children between 10 and 16 years of age. Only six neoplasms were encountered in children of 5 years or younger, four of which were high-grade malignant tumours. Benign tumours were successfully treated by local excision with only one recurrence. Of 46 malignant neoplasms, 8 were treated palliatively; of the remainder 8 were lost to follow-up and 2 patients died of their disease.

Adenomatous ductal proliferation of the salivary gland

OBJECTIVE

The objective of this study is to report a series of patients with adenomatous ductal proliferation of the salivary gland and to investigate the nature and histogenesis of this process.

STUDY DESIGN

The histologic and immunohistochemical studies of 13 patients with adenomatous ductal proliferation of the salivary gland were performed.

RESULTS

Ten cases coexisted with other diseases, such as salivary gland tumor or chronic parotitis. Most of the lesions were limited to 1 or 2 lobules and showed prominent ductal proliferation with some acinar cell complexes. The proliferative ducts had a compact growth pattern with little stroma. Dedifferentiation of acinar cells, identified by the loss of their secretory granules and appearing similar to intercalated duct epithelium, was seen in the early stages of adenomatous ductal proliferation.

CONCLUSION

Acinar cells play a role in the histogenesis of salivary gland tumors because acinar cells clearly participate in the formation of the proliferative ducts.

Unicystic ameloblastoma: a clinicopathologic study of 33 Chinese patients

The term unicystic ameloblastoma refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst, but on histologic examination show a typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/or mural tumor growth. To ascertain the clinicomorphologic spectrum and biologic behavior of this tumor group, the clinicopathologic features of 33 unicystic ameloblastomas from Chinese patients were studied. This series represents approximately 19% of all cases of ameloblastoma accessioned in the authors' hospital during a 15-year period. Twenty-one patients were male and 12 were female, for a total of 33 patients. The age at diagnosis ranged from 8 to 60 years (mean, 25.3 yrs) and peaked at the second and third decades (70%), Thirty tumors (91%) occurred in the mandible and three in the maxilla. Of the 29 patients with a radiographic record, an expansive unilocular radiolucency was seen in 22 cases, and was multilocular in seven cases. Microscopically, all tumors demonstrated a generally monocystic growth pattern. Eight tumors were simple cystic, 10 comprised intraluminal tumor nodules, and the remaining 15 had a conspicuous component of infiltrative tumor islands in the cyst capsule. The cystic tumor linings invariably showed, at least in part, a typical ameloblastomatous pattern that was often accompanied by epithelial areas of various histologic appearance. Follow up of 29 patients revealed no recurrence in less than 4 years of follow up, but did reveal a 35% recurrence rate at more than 4 years of follow up. The average interval to recurrence was approximately 7 years. Recurrence also appeared to relate to histologic subtypes of unicystic ameloblastoma, with those invading the fibrous wall having a rate of 35.7%, but other types having a rate of 6.7%. Despite the fact that unicystic ameloblastoma may, in general, compare favorably with its solid or multicystic counterpart in terms of clinical behavior and response to treatment, the subsets of the maxillary lesions or tumors containing invading islands in the fibrous wall could have a high risk of recurrence. Furthermore, recurrence of unicystic ameloblastoma may be long delayed, and a long-term postoperative follow up is essential to the proper management of these patients.

Endogenous fatty acid synthesis in squamous cell carcinomas of the oral cavity

We measured the synthesis of endogenous fatty acids in oral squamous cell carcinoma, its adjacent tissue, and normal oral tissues that were collected fresh from surgical specimens. The tissues were minced in Roswell Park Memorial Institute Medium 1640 (RPMI 1640) and incubated in [1(2)-(14)C] acetic acid, sodium salt ((14)CH(3)(14)CO(2)Na). Total lipids were then extracted and(14)C was measured by scintillation counter. We found that incorporation of(14)C in the total lipids of squamous cell carcinoma was significantly higher than in the other tissues.

Possible effects of the Three Gorges dam on the transmission of Schistosoma japonicum on the Jiang Han plain, China

The Three Gorges dam, under construction on the Yangtze River in China, might affect the transmission of Schistosoma japonicum on the Jiang Han plain, which is downstream of the dam. To study this possibility, the prevalence of schistosomiasis was investigated in relation to a range of malacological, hydrological and meteorological factors. The general water level in the Yangzte over a year had a marked effect on the distribution of the intermediate host (Oncomelania hupensis) and the prevalence of human schistosomiasis in that year. Disease prevalence showed significant correlations with the density of the snail hosts, the level of the water table, annual rainfall, yearly evaporation, and altitude. Once the dam is complete, the flow of water downstream will probably be maintained at a level between those currently occurring in flood and dry weather, and this may have implications for schistosome transmission. Systematic monitoring is necessary to investigate the impact of the environmental changes brought about by the dam on transmission.

[Overproduction of cholera toxin B subunit by recombinant Escherichia coli MM2 in lactate-containing medium]

The expression of ctb gene in recombinant E. coli MM2 strain is affected by temperature, pH and carbon source. High level production of cholera toxin B subunit (CTB) was investigated in lactate-containing medium which designed by experiments of orthogonal test. Upshifting temperature from 30 degrees C to 37 degrees C could increase the production of CTB by 4 fold, upshifting pH value from 7.2 to 8.4 at the later culture stage could increase the specific expression level of CTB by 2.14 fold, and adding sodium acetate increased the production of CTB by 65%. In 5 L fermentor the cell density was reached at OD600 30, and the 186.7 mg/L of CTB was obtained. The CTB in the culture supernatants was in the form of polymer like the native CTB from Sigma, and also possessed the same antigenity.

Impact of environmental change and schistosomiasis transmission in the middle reaches of the Yangtze River following the Three Gorges construction project

With the construction of the Three Gorges high dam on the Yangtze River in China in mind, a serious of ecological environmental factors that might affect the transmission of Schistosoma japonicum in Jian Han Plain were investigated by means of data collection, field surveys and observation in Hubei Province. Several ecological factors including water level of the Yangtze River; riparian water table, annual rainfall and yearly evaporation were investigated in relation to the prevalence of schistosomiasis. The results suggest that after the dam construction, middle water level flows (ie between flood flows and dry-weather flows) will persist in the flood season due to a rise in the water table. The investigation indicated that snail distribution and human schistosomiasis prevalence differed significantly between years which had typically high, middle and low typical water levels in the Yangzte. Moreover, the prevalence of the disease showed a significant linear regression relationship with density of snail intermediate hosts, water table, annual rainfall, yearly evaporation and ground altitude in the survey area. Systematic and careful monitoring and surveillance is necessary to investigate the impact of the environmental changes brought about by the dam construction on schistosomiasis transmission.

Histogenesis and development of membranous basal cell adenoma

The histogenesis of salivary gland tumors remains controversial. A histologic and immunohistochemical study was carried out on 12 cases of membranous basal cell adenoma in the salivary glands to investigate its histogenesis and development. In 4 cases, multiple focal proliferations of striated ducts in the surrounding salivary gland, which were conspicuous, allowed tracing of the development of the tumors from their origin. The earliest changes were characterized by hyperplasia of the basal cells of striated ducts. Continuous ductal proliferation led to the formation of microadenomas. The observations suggest that proliferating basal cells of striated ducts apparently participate in and play a main role in the histogenesis of some membranous basal cell adenomas of the salivary glands.