[Diagnostic performances of salivary gland ultrasonography for Sjögren's syndrome].

OBJECTIVE: To evaluate the diagnostic performances of salivary gland ultrasonography(SGUS)in Sjögren's syndrome(SS). METHODS: A total of 246 patients with dry mouth and/or eyes who were treated in the outpatient department and inpatient department of Rheumatology and Immunology Department of the Ninth People's Hospital, Shanghai Jiaotong University School of Medicine from December 2019 to January 2022 were collected. All patients received SGUS examination and scored by 2019 outcome measures in rheumatology clinical trial (OMERACT)ultrasonic scoring system.Their general information, unstimulated saliva flow rate(USFR), Schirmer test and serological test results were recorded. In the study, 193 cases had lip gland biopsy. The 2016 American College of Rheumatology(ACR)/ European League Against Rheumatism(EULAR)classification criteria were adopted as the diagnostic standard of SS. χ2 test was used to compare the difference of salivary gland ultrasonic scores between the two groups. The receiver operating characteristic(ROC) curve was used to evaluate the accuracy of SGUS in diagnosing SS, and the disease characteristics of SGUS positive group and negative group in the SS patients were compared. RESULTS: A total of 175 patients were SS group according to the ACR/EULAR classification, and the remaining 71 patients were non-SS group.There was no significant difference in age [(54.2±11.8) years vs. (53.4±14.9) years, P=0.705] and female (94.4% vs.93.1%, P=1.000) between SS and non-pSS groups. A total of 109 patients were SGUS positive (≥ 2 points), of whom 104 patients met the SS diagnosis and 5 patients did not meet the SS diagnosis. The positive rate of SGUS in SS group was significantly higher than that in non-SS group (59.4% vs. 7.0%, P < 0.001). The accuracy of 2019 OMERACT ultrasonic scoring system to predict ACR/EULAR classification was good, with an area under the curve of 0.762 (95%CI 0.701-0.823). The absolute agreement between the SGUS outcome and ACR-EULAR classification was 69.1%(170/246), with a sensiti-vity of 59.4%(104/175), specificity of 93%(66/71), positive predictive value of 95.4%(104/109) and negative predictive value of 48.2% (66/137). A total of 81 patients were positive SGUS combined with anti-SSA antibody, 100% (81/81) fulfilled the ACR-EULAR criteria, 85 patients were negative SGUS and anti SSA antibody, and 60 patients(70.6%, 60/85) did not fulfil the ACR-EULAR criteria. SGUS positive group had higher antinuclear antibody(ANA) positive rate(83.1% vs. 98.1%, P < 0.001) in the patients with SS. CONCLUSION: The OMERACT ultrasonic scoring system has high diagnostic value in SS. The combination of SGUS and anti-SSA antibody can improve the diagnostic value.

[The diagnostic potential of Golgi protein 73 for cirrhosis in patients with chronic hepatitis C].

Objective: To explore the diagnostic value and model of serum Golgi protein 73 (GP73) in patients with hepatitis C cirrhosis. Methods: 271 cases with chronic hepatitis C virus infection who were treated in the Fifth Medical Center of PLA General Hospital from January 2010 to December 2017 were retrospectively collected as the research objects, including 126 cases with hepatitis and 145 cases with liver cirrhosis. Serum GP73 and liver stiffness measurement (LSM) based on transient elastography test were performed in all patients. Simultaneously, blood routine, liver function, coagulation function and other related indicators were collected. GP73 diagnostic efficiency for liver cirrhosis was evaluated by receiver operating characteristic curve (ROC). GP73 diagnostic value was clarified after comparison with aspartate aminotransferase/platelet ratio index (APRI), FIB-4 index (FIB-4) and LSM. Compensated hepatitis C virus-related cirrhosis diagnostic model based on serological index was established by logistic regression analysis. Results: The area under the receiver operating characteristic curve (AUC) of GP73, LSM, FIB-4 and APRI in the diagnosis of compensated hepatitis C virus-related cirrhosis were 0.923, 0.839, 0.836 and 0.800 respectively, and GP73 had the best diagnostic efficiency (P <0.001). LSM and GP73 combined use had improved the diagnostic sensitivity of cirrhosis to 97.24%. Multivariate logistic regression analysis revealed that GP73, age, and platelets were independent predictors of cirrhosis.Compensated hepatitis C virus-related cirrhosis diagnostic model (GAP) was established based on the result: LogitP=1/[1+exp(6.145+0.013×platelet-0.059×age-0.059×GP73)].AUC model for diagnosing compensated liver cirrhosis was 0.944, and the optimal cut-off value was 0.56, with sensitivity and specificity of 84.03% and 92.06%, respectively, and the diagnostic efficiency of this model was better than that of APRI, FIB-4, LSM and GP73 alone (P<0.05). Conclusion: GP73 is a reliable serum biomarker for the diagnosis of compensated hepatitis C virus-related cirrhosis. The GAP diagnostic model based on GP73, platelet count, and age can further improve the diagnostic efficiency and help to diagnose patients with compensated hepatitis C virus-related cirrhosis.

[Metabolomics study of tris(2-chloroethyl) phosphate induced hepaotoxicity and nephrotoxicity in Sprague-Dawley rats].

Objective: To discuss the potential toxic target organ and the toxic effects and mechanisms of tris (2-chloroethyl) phosphate (TCEP) on SD rats. Methods: 40 female SD rats weaning from milk for 21 days, weighted (50±2.3)g were selected as subjects and marked by the weight. They were randomly divided into 4 groups, namely control group, 50 (L), 100 (M) and 250 (H) mg·kg(-1)·d(-1) dose of TCEP group. Each group has 10 rats, and administrated the corresponding dose of drug or vehicle by mouth, quaque die for 60 days. All rats were sacrificed after the last administration. The livers and kidneys were dyed by HE for pathological observation; and the blood samples were collected to analyze the biochemical index. H(1)-Nuclear Magnetic Resonance ((1)H-NMR)-based metabolomics methods coupling with histopathogy examination were used to investigate the toxic effects of TCEP. Results: Inflammatory cell infiltration and hepatic necrosis were observed in the liver of TCEP-treated rats. Inflammatory cells invaded and calcification/ossification foci were also found in renal of TCEP-treated rats and tumor hyperplasia were existed in renal tubule in H group. The level of HDL-C in the L, M and H group were separately (1.7±0.09) , (1.5±0.07) and (1.3±0.1) µmol/L, which were all significantly lower than that of control group ( (1.9±0.2) µmol/L) (P<0.05) . The activity of cholinesterase (CHE) in the L, M and H group were separately (918±14.8) , (828±28.6) and (674±36.5) U/L, which were all significantly lower than that of control group ((1056±28.8) µmol/L) (P<0.05). Moreover, The level of creatinine (CRE) in the L, M and H group were separately (29.8±4.6) , (28.9±5.3) and (25.8±6.2) µmol/L, which were all significantly lower than that of control group ((30.2±3.9) µmol/L) (P<0.05). In the H group, the enzyme activities of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), alkaline phosphatase (ALP) and the contents of total bilirubin (TBIL), glucose (GLU) and uric acid (UA) were all significantly higher than the results in control group. The results of (1)H-NMR metabolomics showed that the contents of lactate, glycine, high-density lipoprotein, low-density lipoprotein and phosphatidylcholine in blood of rats would decrease by TCEP exposure, while N-acetylglycoprotein, acetate, alanine, glucose, lipids, lipoproteins and fatty acids would increase. Conclusion: TCEP caused disorders in endogenous energy metabolism, leading to the pathological changes of inflammatory cells infiltration and necrosis in liver and kidney, caused enzyme activity changes of ALT, ALP and the content changes of other liver and kidney injury-related markers.

[Modified percutaneous vertebroplasty assisted by preoperative CT-based digital design: a new technique for osteoporotic vertebral compression fracture].

OBJECTIVE: To report a new technique of modified percutaneous vertebroplasty (PVP) assisted by preoperative CT-based digital design for osteoporotic vertebral compression fracture (OVCF), and to discuss its preliminary clinical results. METHODS: Thoracolumbar spine segment data (Dicom format) were obtained from lamellar CT scanning of seven old female or male with single OVCF. A three-dimensional model of thoracolumbar spine and simulative PVP models (via double transpedicular approach) were built in the Mimics software. With the help of a preoperative transparent marker located at the back midline skin and preoperative digital design by Mimics software, the needle insert point and needle direction in every patient were established. The surgical time, the number of intraoperative radiation perspective, bone cement filling condition in fracture vertebra, intraoperative complications and visual analogue scale (VAS) scores before and after surgery were recorded to evaluate the preliminary clinical results after modified PVP. RESULTS: The puncture process during PVP was in high accordance with the preoperative digital design by Mimics software in seven cases of single OVCF with the average age of 78 years old. The operation time was only 16.57±2.07 minutes and the intraoperative radiation perspective numbers were less than ten (7.86±1.68) times. The bone cement filling in all fracture vertebras were good and no surgical complications such as spine cord injury and cement leakage were founded. The VAS scores before and after surgery were 8.57±0.53 points and 1.43±0.53 point (P=0.000), respectively. CONCLUSION: Percutaneous vertebroplasty (PVP) assisted by preoperative CT-based digital design has high accuracy, which is expected to reduce operation time, intraoperative radiation exposure and the surgical complications related to puncture failure.

A 2-Stage Root Analog Implant with Compact Structure, Uniform Roughness, and High Accuracy.

Immediate implant placement has the advantages of shortening the operation time, reducing the treatment cycle and cost. At present, this technology has been used widely, but the indications of immediate implantation are still limited. Here, a novel type of root analog implant (RAI) was manufactured by selective laser melting technology to address the limitation. Under optimized condition, RAIs were printed with the internal density of 99.73% and the uniform surface roughness of 11 µm (Sa). Besides, the deviation between RAI specimen and design models is controlled within 0.15 mm after optimizing scanning parameters. The substrate printed could promote human bone marrow stromal cell proliferation, spreading, and osteogenic differentiation. The bone-implant contact (BIC, 75% ± 7%) and bone volume/total volume (BV/TV, 74% ± 7%) of RAIs were significantly higher than that of conventional implants (BIC, 66% ± 5%; BV/TV, 62% ± 5%) in in vivo experiments. Further, customized abutments were designed for the RAIs, improving the masticatory ability of the beagle dogs after crown restoration. This study aims to design a personalized 2-stage RAI with compact structure and uniform roughness, in order to achieve better fracture resistance, initial osseointegration efficiency, and dispersed stress in immediate implantation. It provides a certain guiding value for standardizing the manufacture and clinical application of RAI in immediate implantation.

Endoscope-controlled maxillary sinus floor elevation: a review of the literature.

A systematic review of the literature was conducted to assess the safety and efficacy of endoscope-assisted maxillary sinus elevation. PubMed, Embase, Web of Science, and the Cochrane database were searched for articles in English. Published studies involving patients who had undergone endoscope-assisted maxillary sinus floor augmentation were selected. The validity of the included articles was evaluated. After going through full texts, a total of 12 studies met the eligibility criteria and were included. It was concluded that endoscope-controlled maxillary sinus floor elevation was a viable and beneficial method, providing direct visualisation of the integrity of the mucosa and placing of bone graft material. The endoscope could be inserted into the maxillary sinus lumen, subantral space below the Schneiderian membrane, or through the alveolar crest. With the endoscope, perforations can be detected and managed precisely. However, high-quality clinical trials are still needed to validate the predictability and advantages of this surgical procedure.

[Effects of platelet-rich plasma combined with polylactic acid/polycaprolactone on healing of pig deep soft tissue defect caused by fragment injury].

Objective: To investigate the effects of platelet-rich plasma (PRP) combined with polylactic acid/polycaprolactone (PLA/PCL) on healing of mininature pig deep soft tissue defect caused by fragment injury. Methods: Two male Bama miniature pigs with 11 to 12 months (the same below) were selected by lottery to prepare PRP. The other twenty-seven male Bama miniature pigs were used to reproduce deep soft tissue defect caused by high-explosive ammunition fragment injury on bilateral posterior femoral region. According to the random number table, 27 pigs were divided into control group, material group, and PRP+material group, with 9 pigs in each group. After debridement, wounds of pigs in material group and PRP+material group were filled with PLA/PCL and PLA/PCL+2 mL activated PRP, respectively. Pigs in each group received suture of full-thickness skin to close the wounds. The operative duration was recorded. The length and volume of wounds of pigs in the above groups were measured immediately after surgery. In 1, 2, and 4 weeks after surgery, 3 pigs in each group were sacrificed to collect femoral wounds tissue on two sides, and PLA/PCL were collected from wounds of pigs in material group and PRP+material group for general observation of wounds tissue and degradation of the material. In 2 and 4 weeks after surgery, wounds tissue was obtained to observe the histological changes by hematoxylin-eosin staining, and expressions of transforming growth factor ß (TGF-ß) and vascular endothelial growth factor (VEGF), and angiogenesis were determined by immunohistochemical method. In 1, 2, and 4 weeks after surgery, wounds tissue was collected to determine mRNA expressions of TGF-ß and VEGF by real-time quantitative reverse transcription polymerase chain reaction. Data were processed with analysis of variance of factorial design, one-way analysis of variance, and least significant difference-t test. Results: (1) There were no significantly statistical differences in length and volume of the wounds of pigs among the three groups (F=0.336, 0.282, P>0.05). The operative duration in control group [(30.9±2.1)min] was significantly shorter than that of material group [(39.7±2.2)min] and PRP+material group[(40.0±2.6)min], t=-11.45, -11.88, P<0.01. (2) There were respectively 10, 7, and 5 wounds tissue with infection in pigs of control group, material group, and PRP+material group. In 1, 2, 4 weeks after surgery, all of the wounds tissue of pigs was infected in control group, while none of wounds tissue of pigs was infected in material group and PRP+material group. In pigs of material group and PRP+material group, materials and tissue were easily separated in 1 week after surgery; some materials were integrated with tissue and showed a tendency of degradation in 2 weeks after surgery; materials were completely embedded with tissue in 4 weeks after surgery. (3) In pigs of control group, erythrocytes and inflammatory cells infiltration in wounds tissue were observed in 2 weeks after surgery, and necrotic tissue and inflammatory cells infiltration in wounds tissue were still observed in 4 weeks after surgery. In pigs of material group and PRP+material group, a large number of erythrocytes and inflammatory cells infiltration were observed in 2 weeks after surgery. Compared with that of material group, wounds tissue of pigs in PRP+material group had no inflammatory cells infiltration in 4 weeks after surgery. (4) Protein expressions of TGF-ß in fibroblasts and multinuclear macrophagocytes, VEGF in fibroblasts and vascular endothelial cells, and blood vessel formation in wounds tissue of pigs in PRP+material group were significantly more than those of pigs in control group and material group in 2 and 4 weeks after surgery. (5) The mRNA expression of TGF-ß in wounds tissue of pigs in material group was significantly higher than that in control group in 4 weeks after surgery (t=-3.93, P<0.01). Compared with those of pigs in control group and material group, the mRNA expression of TGF-ß in wounds tissue of pigs in PRP+material group was significantly increased at each time point (t=9.23, 13.81, 11.73, -7.51, -12.04, -7.80, P<0.01). The mRNA expression of VEGF in wounds tissue of pigs increased significantly in material group compared with that of pigs in control group in 4 weeks after surgery (t=-3.94, P<0.01). Compared with those of pigs in control group and material group, the mRNA expression of VEGF in wounds tissue increased significantly in wound tissue of pigs in PRP+material group at each time point (t=12.33, 3.95, 7.97, -11.36, -2.97, -4.04, P<0.01). Conclusions: PRP combined with PLA/PCL can accelerate wound healing of deep soft tissue defect of mininature pigs caused by fragment injury by providing physical scaffold for newborn tissue growth, promoting mRNA and protein expressions of TGF-ß and VEGF.

Development of a chemiluminescence immunoassay using recombinant non-structural epitope-based proteins to accurately differentiate foot-and-mouth disease virus-infected and vaccinated bovines.

The contamination of inactivated vaccine with non-structural proteins (NSPs) leads to a high false-positive rate, which is a substantial barrier to accurately differentiate foot-and-mouth disease virus (FMDV)-infected animals from vaccinated animals. To address this problem, a new chemiluminescence immunoassay (CLIA) method was developed to detect antibodies targeting the two recombinant epitope-based proteins located in 3A and 3B. The 3Aepitp-3Bepitp CLIA exhibited a diagnostic sensitivity of 94.0% and a diagnostic specificity of 97.5% for the detection of serum samples (naïve bovines, n = 52, vaccinated bovines, n = 422, infected bovines, n = 116) from animals with known status. The CLIA method also had a concordance rate of 88.1% with the PrioCHECK FMDV NSP ELISA based on the detection of 270 serum samples from the field. Importantly, the 3Aepitp-3Bepitp CLIA produced no false-positives when used to detect FMDV in samples from bovines that had been vaccinated up to five times, and it was demonstrated a low false-positive rate when the bovines had been vaccinated up to ten (2.15%) and fifteen times (5.93%). Therefore, the 3Aepitp-3Bepitp CLIA detects FMDV in samples from frequently vaccinated bovines with high accuracy and represents an alternative method to differentiate FMDV-infected and vaccinated bovines.

Role of extracellular exopolymers in biological phosphorus removal.

Three sequencing batch reactors (SBRs) supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal (EBPR), although all of them were seeded from the same sludge. With the measurement of poly-beta-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPs) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPs played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

L-asparaginase release from Escherichia coli cells with K2HPO4 and Triton X100.

A method to release L-asparaginase (EC 3.5.1.1) from ATCC Escherichia coli 11303 cells by chemical permeabilization was studied. It was found that a combination of K2HPO4 and Triton X100 was effective. The influences of K2HPO4 concentration, Triton concentration, E. coli cell concentration and pH on the release of enzyme and proteins were investigated in detail. Experimental results showed that 12.5% (w/v) K2HPO4, 2% (w/v) Triton X100 and 3 x 10(8) cells/mL made the amount of enzyme released over 70%. L-Asparaginase in K2HPO4 and Triton solution could remain stable at least for 24 h. The release effect of K2HPO4 and Triton X100 used simultaneously was better than that of K2HPO4 and Triton X100 used separately in succession. Electron microscopy indicated that the chemical treatment altered the surface structure of E. coli cells but did not break them. As the method does not produce a large amount of cell fragments and the amount of enzyme released is relatively high, it can be thought to be an valuable and economic method to release intracellular enzyme.

Developmental toxicity and structure-activity relationships of chlorophenols using human embryonic palatal mesenchymal cells.

The chlorophenols (CPs) comprise a major class of widely distributed and frequently occurring environmental contaminants. Previous studies have demonstrated the adverse effects of CPs on embryonic and fetal development. HEPM (human embryonic palatal mesenchymal) and MOT (mouse ovarian tumor) cell lines have been utilized in complementary bioassays for the detection of teratogens, but not the CPs. In this study, our objectives were 2-fold: (1) to determine if the HEPM assay could be used to complement other bioassay systems of nonhuman origin, i.e., Hydra attenuata (HA) and rat whole embryo culture (WEC), in the evaluation of the developmental toxicity of CPs, and (2) to delineate the ability of the HEPM assay to evaluate structure-activity relationships of pentachlorophenol (C5P), 2,3,4,5-tetrachlorophenol (C4P), 2,3,5-trichlorophenol (C3P), 3,5-dichlorophenol (C2P), 4-monochlorophenol (CP), phenol, and CP derivatives (i.e., acetates, sodium phenates and anisoles). HEPM cells were seeded into each well of a 24-well plate and cultivated for 24 h. The medium was replaced with fresh medium containing various concentrations of test chemicals dissolved in dimethyl sulfoxide (DMSO, 0.1%). After culturing for 72 h, the medium was removed, cells were trypsinized, and cell number determined. The HEPM cell growth inhibition assay demonstrated a linear relationship between the IC50 values of the CPs and degree of chlorine substitution. The IC50 values of C5P, C4P, C3P, C2P, CP, and phenol were 18.8, 21.5, 27.5, 63.0, 150.0 and 470.0 microM, respectively. A clear structure-activity relationship was observed between toxicity of CPs and the degree of chlorine substitution. The rank order of CP toxicity from the HEPM assay (i.e., C5P > C4P > C3P > C2P > CP > phenol) is in excellent agreement with previous in vitro and in vivo studies. However, contrary to published reports, the HEPM assay predicted that all CPs were teratogenic (false positives). These findings suggest that the HEPM cell growth inhibition bioassay may be useful to discriminate between subtle differences in structure-activity and, in combination with other bioassays, might facilitate the rapid detection and prioritization of diverse cytotoxins, including various developmental toxicants. Importantly, conclusions about the teratogenicity of a test chemical (via HEPM testing) should be approached with caution and confirmed with other teratogen-sensitive systems.

Photodynamic therapy in the treatment of malignant tumours: an analysis of 540 cases.

Malignant tumours (540 cases), including tumours of the lung, oesophagus, cardia, stomach, rectum, bladder, other urinary genital organs, face and mouth, eyes, ear, nose and throat (ENT), head and neck, breast and skin, were treated using photodynamic therapy (PDT) between 1982 and 1985 in Beijing. All of the cases were identified pathologically and the patients received haematoporphyrin derivative (HPD) (5 mg kg-1) intravenously 48-72 h prior to PDT. An argon-pumped dye laser emitting at 630 nm was used for the treatment. The results were as follows: complete response (CR) was obtained in 227 cases (42.1%), partial response (PR) was obtained in 114 cases (21.1%), mild response (MR) was obtained in 120 cases (22.2%) and 79 cases (14.6%) showed no response (NR). The effectiveness of PDT in the different organs was compared. HPD fluorescence was examined in 409 cases of malignant tumours: 344 lesions (84.1%) revealed red fluorescence (positive reaction), 32 gave an equivocal response and 33 gave a negative reaction. Positive fluorescence was seen in all types of malignant tumour in our study. Indications and limitations of PDT for the different organs are discussed and compared.

Surface treatment of injectable strontium-containing bioactive bone cement for vertebroplasty.

A novel injectable bioactive bone-bonding cement (SrHAC) composed of strontium-containing hydroxyapatite (Sr-HA) as the inorganic filler and bisphenol A diglycidylether dimethacrylate (Bis-GMA) as the organic matrix for vertebroplasty was developed previously. In this study, the Sr-HA powders were surface treated with methyl methacrylate (MMA) to improve the interface integration of the two phases. After surface treatment, the compression strength and Young's modulus, which were tested after immersion in distilled water at 37 degrees C for 24 h according to ISO 5833, were increased by 68.65 % (p <.001) and 31.02% (p <.001), respectively. The bending strength and bending stiffness of the bioactive bone cement were significantly improved by 54.44% (p <.001) and 83.90% (p <.001). In addition, the handling property of the cement was also enhanced. In vitro biomechanical testing showed that the stiffness of the fractured spine recovered to 82.5% (p <.01) of the intact condition after cementation with surface-treated SrHAC. The failure load of the spine cemented with original and MMA-treated SrHAC improved by 14.25% (p <.05) and 46.91% (p <.05) in comparison with the fractured spines. Results from this study revealed that the MMA-treated SrHAC has a better mechanical effect for orthopedic applications.

[Studies on coprecipitate of anordrin-PVP].

The coprecipitate of anordrin (AD)-PVP was prepared by solvent method. The DSC (differential scanning calorimetry) revealed that AD did not have crystalline structure in coprecipitates of 1:7-1:9. X-ray diffraction spectrum of 1:8 coprecipitate (COPPT) showed no crystalline structure of AD. The dissolution rate of AD was about 38 times higher for 1:8 COPPT than pure AD. Activation energies determined by DTG (derivative thermogravimetry) were 182.8 and 133.4 kJ/mol, respectively, showing that the 1:8 COPPT is much more stable than pure AD in thermal degradation. The experimental results showed that anti-implantation effect of the 1:8 COPPT was much better than that of AD tablets: the number of implantation sites of mice administrated 1:8 COPPT (5 mg/kg) was 0.2 (P less than 0.01) and that of mice administrated AD tablets (10.6 mg/kg) was 0.9 (P less than 0.05); effective dose of 1:8 COPPT was less than half of that of AD tablets.

Osteogenic behavior of alginate encapsulated bone marrow stromal cells: an in vitro study.

Sodium alginate is a useful polymer for the encapsulation and immobilization of a variety of cells in tissue engineering because it is biocompatible, biodegradable and easy to process into injectable microbeads. Despite these properties, little is known of the efficacy of calcium cross-linked alginate gel beads as a biodegradable scaffold for osteogenic cell proliferation and differentiation. In this study, we investigated the ability of rabbit derived bone marrow cells (BMCs) to proliferate and differentiate in alginate microbeads and compared them with BMCs cultured in poly-L-lysine (PLL) coated microbeads and on conventional 2D plastic surfaces. Results show that levels of proliferation and differentiation in microbeads and on tissue culture plastics were comparable. Cell proliferation in microbeads however diminished after fortification with a coating layer of PLL. Maximum cell numbers observed were, 3.32 x 10(5) +/- 1.72 x 103; 3.11 x 10(5) +/- 1.52 x 10(3) and 3.28 x 10(5) +/- 1.21 x 10(3 ) for the uncoated, PLL coated and plastic surface groups respectively. Alkaline phosphatase and protein expressions reflected the stage of cell differentiation. We conclude that calcium cross-linked alginate microbeads can act as a scaffold for BMC proliferation and osteogenic differentiation and has potential for use as 3D degradable scaffold.

Bone density measurements in intra-oral radiographs.

Jaw bone density measurements are applicable in many clinical situations to assess bone tissue. To be able to implement research findings in clinical reality, tools must be simple and low cost. Intra-oral radiographs including a reference material perform well as a densitometric tool. However, the inclusion of a reference material, usually in the form of a metal wedge, is an additional burden for the dentist. The aim of this study was to evaluate whether a reference step wedge is required for accurate densitometric results. Dual energy X-ray absorptiometry measurements and densitometric measurements on intra-oral radiographs using a custom-made software were performed on bone samples from the premolar region of the mandible. Observer agreement of bone density expressed as grey value was high. The correlation between mandibular bone mineral density and the densitometric values on intra-oral radiographs was substantially higher when the aluminium step wedge was included. The Wilcoxon test revealed no significant difference between the density measurements using nine or three steps of the Al reference wedge. Density determination of grey value and mm Aleq thickness value both have good intra- and inter-observer agreement. However, jaw bone densitometry is far more accurate when including a reference wedge.

In vitro evaluation of alginate encapsulated adipose-tissue stromal cells for use as injectable bone graft substitute.

This study aims to investigate the survival and osteogenic behavior of murine-derived adipose-tissue stromal cells (ATSCs) encapsulated in alginate microcapsules thereby instigating further studies in this cell delivery strategy for in vivo osteogenesis. Cell viability was quantified using a tetrazolium-based assay and osteogenic differentiation was evaluated by both alkaline-phosphatase (ALP) histochemistry and osteocalcin mRNA analysis. Following microencapsulation, cell numbers increased from 3.9 x 10(3) on day 1 to 7.8 x 10(3) on day 7 and maintained excellent viability in the course of 21-day culture. ALP was 6.9, 5.5, and 3.2 times higher than monolayer cultures on days 7, 14, and 21, respectively. In addition, osteocalcin mRNA was detectable in encapsulated cultures earlier (day 14) than monolayer cultures. We conclude that alginate microcapsules can act as three-dimensional matrix for ATSC proliferation and has potential for use as injectable, biodegradable scaffold in bone tissue engineering.

[Effects of ultrasonography on evaluating the status of cervical lymphatic metastasis in patients with oral squamous cell carcinoma].

OBJECTIVE: To investigate effects of ultrasonography on evaluating the status of cervical lymphatic metastasis in patients with oral squamous cell carcinoma (OSCC). METHODS: Nineteen OSCC patients with the diagnosis confirmed by biopsy of primary focus were included in this study. All the patients were hospitalized in the department of stomatology, Beijing Medical University during June, 1995 and June, 1996, among them there were 13 men and 6 women. The ages were ranged from 31 to 71 years old, with the average of 54.4 years old. The primary focus of 13 cases were in tongue, 3 cases in cheek, 2 cases in gum, and 1 case in the conjunction of gum, mouth floor and tongue respectively. All the patients were examined by ultrasonography prior to operation, and operated with the procedures of excision of primary focus and radical neck dissection. The length, width, Vmax and Vmin and Resistance Index (RI = (Vmax-Vmin)/Vmax) of blood flow of cervical lymphatic nodes were measured with acuson 128 xp/10 color Doppler flow imaging scanner with a 7.5 MHz probe. The total of 34 cervical lymphatic nodes were examined by the scanner. L/W ratios in all nodes, RI and Vmax in 16 nodes were obtained respectively. All results were divided into two groups, metastases and non-metastases groups based on the pathological findings for further statistic analysis. Student t test was employed in the study. RESULTS: The average L/W ratios, the average Vmax and the average RI were 1.95 and 2.17, 0.24 and 0.14, and 0.80 and 0.56 in metastases and non-metastases groups respectively. There was a significant difference between RI in two groups, but no statistical differences were revealed in L/W ratios and Vmax, despite the great difference in the average Vmax in the two groups. When RI > or = 0.65 and Vmax > or = 0.20 m/s were regarded as the criterion for positive diagnosis, the accuracy rate, the sensibility and the specificity was 91.2%, 90%, and 91.7% respectively in making diagnosis of OSCC. CONCLUSION: The status of cervical lymphatic metastases in OSCC patients could be evaluated accurately by the color Doppler flow imaging scanner, which might be helpful in making accurately diagnosis of OSCC, selecting the appropriate operation procedure of neck dissection leading to increased survival ratio and improved quality of life for the patients.

[Study on chitosan-gelatin/hydroxyapatite composite scaffolds--preparation and morphology].

OBJECTIVE: To prepare chitosan-gelatin/hydroxyapatite (CS-Gel/HA) composite scaffolds, and to investigate the influence of components and preparing conditions to their micromorphology. METHODS: The CS-Gel/HA composite scaffolds were prepared by phase-separation method. Micromorphology and porosity were detected by using scanning electron microscope and liquid displacement method respectively. RESULTS: Porous CS-Gel/HA composite scaffolds could be prepared by phase-separation method, and their density and porosity could be controlled by adjusting components and quenching temperature. CONCLUSION: The study suggests the feasibility of using CS-Gel/HA composite scaffolds for the transplantation of autogenous osteoblasts to regenerate bone tissue.

Crystallization and preliminary crystallographic data of fructose-1,6-bisphosphatase from human muscle.

The enzyme human muscle fructose-1,6-bisphosphatase, which plays a critical role in gluconeogenesis, has been crystallized in the presence of 2-propanol, polyethylene glycol and magnesium chloride at pH 7.5. The space group was determined to be P4(2)2(1)2, with unit-cell parameters a = b = 73.57, c = 146.50 A, alpha = beta = lambda = 90 degrees and one subunit in the asymmetric unit. A 99.6% complete data set to 2.04 A has been collected at the National Synchrotron Light Source.