Nanobodies for Accurate Recognition of Iso-tenuazonic Acid and Development of Sensitive Immunoassay for Contaminant Detection in Foods.

The accurate analysis of chemical isomers plays an important role in the study of their different toxic effects and targeted detection of pollutant isomers in foods. The Alternaria mycotoxins tenuazonic acid (TeA) and iso-tenuazonic acid (ITeA) are two isomer mycotoxins with the lack of single analysis methods due to the similar structures. Antibody-based immunoassays exhibit high sensitivity and superior application in isomer-specific determination. Previously, various kinds of antibodies for TeA have been prepared in our group. Herein, highly specific nanobodies (Nbs) against ITeA mycotoxin were selected from immune nanobody phage display library, and one of Nbs, namely Nb(B3G3) exhibited excellent affinity, thermal stability as well as organic solvent tolerance. By molecular simulation and docking technology, it was found that stronger interaction between Nb(B3G3) and ITeA lead to higher affinity than that for its isomer TeA. Furthermore, a sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA) was established with a limit of detection (LOD) of 0.09 ng/mL for ITeA mycotoxin. The recovery rate of ITeA in spiked samples was analyzed with 84.8%-89.5% for rice, 78.3%-96.3% for flour, and 79.5%-90.7% for bread. A conventional LC-MS/MS method was used to evaluate the accuracy of this proposed icELISA, which showed a satisfactory consistent correlation. Since the convenient strategy for nanobody generation by phage display technology, this study provide new biorecognition elements and sensitive immunoassay for analysis of ITeA in foods.

Chemiluminescent Enzyme Immunoassay and Bioluminescent Enzyme Immunoassay for Tenuazonic Acid Mycotoxin by Exploitation of Nanobody and Nanobody-Nanoluciferase Fusion.

The isolation of nanobodies (Nbs) from phage display libraries is an increasingly effective approach for the generation of new biorecognition elements, which can be used to develop immunoassays. In this study, highly specific Nbs against the Alternaria mycotoxin tenuazonic acid (TeA) were isolated from an immune nanobody phage display library using a stringent biopanning strategy. The obtained Nbs were characterized by classical enzyme-linked immunosorbent assay (ELISA), and the best one Nb-3F9 was fused with nanoluciferase to prepare an advanced bifunctional fusion named nanobody-nanoluciferase (Nb-Nluc). In order to improve the sensitivity and reduce the assay time, two different kinds of luminescent strategies including chemiluminescent enzyme immunoassay (CLEIA) and bioluminescent enzyme immunoassay (BLEIA) were established, respectively, on the basis of the single Nb and the fusion protein Nb-Nluc for TeA detection. The two-step CLEIA was developed on the basis of the same nanobody as ELISA, only with simple substrate replacement from 3,3',5,5'-tetramethylbenzidine (TMB) to luminol. In contrast with CLEIA, the novel BLEIA was conducted in one-step new strategy on the basis of Nb-Nluc and bioluminescent substrate coelenterazine-h (CTZ-h). Their half maximal inhibitory concentration (IC50) values were similar to 8.6 ng/mL for CLEIA and 9.3 ng/mL for BLEIA, which was a 6-fold improvement in sensitivity compared with that of ELISA (IC50 of 54.8 ng/mL). Both of the two assays provided satisfactory recoveries ranging from 80.1%-113.5% in real samples, which showed better selectivity for TeA analogues and other common mycotoxins. These results suggested that Nbs and Nb-Nluc could be used as useful reagents for immunodetection and that the developed CLEIA/BLEIA have great potential for TeA analysis.

Visual upconversion nanoparticle-based immunochromatographic assay for the semi-quantitative detection of sibutramine.

Immunochromatographic assay (ICA) has been used widely for the onsite monitoring of illegal additives due to its simplicity, speed, and low cost. However, a scanner is commonly required for ICA to achieve quantitative results. In this work, we developed a visual semi-quantitative ICA for sibutramine, a banned additive in diet foods, without the need for a scanner for measurement. Monoclonal antibodies specific for sibutramine were raised and conjugated with upconversion nanoparticles (UCNPs) as the luminescent tracer. ICA was developed by employing multiple test lines to achieve the semi-quantitative detection of sibutramine. Based on the optimal conditions, the cutoff levels (limit of quantitation, LOQ) of T1 line, T2 line, T3 line, and T4 line were 0.02 µg/mL, 0.15 µg/mL, 1.0 µg/mL, and 7.5 µg/mL, respectively, in buffer system. The ICA demonstrated a LOQ at 0.2 mg/kg for sibutramine in diet food samples. The assay (including pretreatment) can be finished within 30 min without the aid of other instruments, except a laser pen. No false positive or false negative results were observed. The results indicated that the proposed method was reliable, simple, and rapid for the screening of sibutramine abuse in diet food samples.

A rapid and simple fluorescence enzyme-linked immunosorbent assay for tetrabromobisphenol A in soil samples based on a bifunctional fusion protein.

Tetrabromobisphenol A (TBBPA) is the largest brominated flame retardant which can be released to environment and cause long-term hazard. In this work, we developed a rapid and highly sensitive fluorescence enzyme-linked immunosorbent assay (FELISA) for monitoring of TBBPA in soil samples. TBBPA specific nanobody derived from camelid was fused with alkaline phosphatase to obtain the bi-functional fusion protein, which enable the specific binding of TBBPA and the generation of detection signal simultaneously. The assay showed an IC50 of 0.23 ng g-1, limit detection of 0.05 ng g-1 and linear range from 0.1 to 0.55 ng g-1 for TBBPA in soil samples. Due to the high resistance to organic solvents of the fusion protein, a simple pre-treatment by using 40% dimethyl sulfoxide (DMSO) as extract solvent can eliminate matrix effect and obtain good recoveries (ranging from 93.4% to 112.4%) for spiked soil samples. Good relationship between the results of the proposed FELISA and that of liquid chromatography tandem mass spectrometry (LC-MS/MS) was obtained, which indicated it could be a powerful analytical tool for determination of TBBPA to monitor human and environmental exposure.

Prevention of contamination by biopsy needle track contamination using a novel adriamycin-loaded gelatin sponge.

BACKGROUND: The gold standard of tumor diagnosis is histological examination of a biopsy; however, there is concern that tumor cell dissemination along the needle track during percutaneous biopsy can cause local tumor relapse. We aimed to evaluate the value of an adriamycin (ADM)-loaded gelatin sponge in preventing tumor cell contamination along the biopsy needle track. METHODS: Data were obtained from 40 patients who were diagnosed by core needle biopsy as having osteosarcoma and who were followed up at our hospital between 2008 and 2011. Of the 40 patients, 20 had the needle biopsy tracks filled with ADM-loaded absorbable gelatin sponge immediately after the biopsy specimen was obtained, while the other 20 did not. All 40 patients underwent limb-salvage surgery, and specimens were obtained from the biopsy track for histopathologic examination of multiple sections. RESULTS: On histological examination, there was less tumor cell contamination along the biopsy tracks in the ADM group. CONCLUSION: Use of ADM-loaded absorbable gelatin sponge may prevent tumor cell contamination of a biopsy track, and reduce the possibility of consequent tumor relapse.

[Treatment of thoracolumbar tumors with total en bloc spondylectomy and the results of spinal stability reconstruction].

OBJECTIVE: To investigate the therapeutic effect of total en bloc spondylectomy (TES) for thoracolumbar tumors and the results of spinal stability reconstruction. METHODS: From January 2007 to June 2011 there were 18 patients with thoracolumbar tumors distributed in the thoracic vertebrae (n = 10) and lumbar vertebrae (n = 8). There were 7 haemangiomas, 5 giant cell tumors of bone, 1 malignant schwannoma, 1 solitary plasmocytoma, 1 neuroblastoma, 1 osteoblastoma, 1 metastatic malignant fibrous histiocytoma, and 1 metastasis of breast cancer. All the 18 patients were treated with improved TES under electrophysiological monitoring of spinal cord. Four patients were treated through one-stage combined anteroposterior approach and 14 patients through one-stage posterior approach. The anterior reconstructions included titanium mesh cages filled with bone or bone cement in 15 cases, titanium mesh cage with strengthened rings in 2 cases and artificial vertebral body replacement in 1 case. The posterior reconstruction included multiple segmental fixation with pedicle screw-rod system in 15 cases and short segmental fixation in 3 cases. Massive bone auto-graft was employed in 13 cases and fragmental bone graft in 5 cases. RESULTS: The total en bloc spondylectomy was performed successfully in 15 patients and unsuccessful in 3 whose spinal tumors were resected by piecemeal technique. In 15 patients with successfully performed TES, the duration of surgery was from 340 to 610 min (average, 450.7 min), the blood loss was from 3000 to 10 200 ml (average, 4850 ml), and the intraoperative blood transfusion was from 2800 to 9600 ml (average, 4200 ml). The operation-related complications comprised hemopneumothorax, intercostal nerve pain, stress ulcer and bleeding, and so on. One year after operation, the patients with neurological dysfunction recovered from grade A to grade D in one patient, and to grade E in the other 14 cases. The average visual analog scale (VAS) scores was 0.5. One patient with plasmacytoma and another one with L5 metastatic tumor suffered progression of the disease and were living with the diseases. The patient with metastatic malignant fibrous histiocytoma died of local recurrence and lung metastasis 16 months postoperatively. One patient with L4 neuroblastoma died of other reason and all the rest were free from relapse. The Cobb angle of upper and lower vertebral body adjacent to the involved vertebrae in sagittal plane was from -26.7° to 12.0° (average, -2.57°) just postoperatively and from -17.5° to 57.2° (average, 11.5°) at the last follow-up or before reoperation. There were 2 patients with screw-rod breakdown and 2 patients with internal fixation loosening. The measurement of titanium mesh cage subsided into adjacent vertebral bodies was average 7.5 mm. The revision surgery was performed in 3 patients, through combined anteroposterior approach in 2 and only posterior approach in 1 patient. CONCLUSIONS: TES significantly increases the therapeutic effect of spinal tumors, although accompanied with high difficulty and massive bleeding. In spinal stability reconstruction after total spondylectomy, it should be emphasized that posterior long segment fixation with pedicle screw-rod system, massive bone bridging graft and the application of thoracolumbosacral orthosis can achieve short-term firm fixation and long-term fusion-stabilization.

Phosphate-triggered ratiometric fluoroimmunoassay based on nanobody-alkaline phosphatase fusion for sensitive detection of 1-naphthol for the exposure assessment of pesticide carbaryl.

The excessive use of carbaryl has resulted in the risk of its exposure. In this study, we isolated six nanobodies (Nbs) from a camelid phage display library against the biomarker of carbaryl, 1-naphthol (1-NAP). Owing to its characteristics of easy genetic modifications, we produced a nanobody-alkaline phosphatase (Nb-CC4-ALP) fusion protein with good stability. A dual-emission system based ratiometric fluoroimmunoassay (RFIA) for quick and highly sensitive determination of 1-NAP was developed. Silicon nanoparticles (SiNPs) was used as an internal reference and for aggregation-induced emission enhancement (AIEE) of gold nanoclusters (AuNCs), while AuNCs could be quenched by MnO2 via oxidation. In the presence of ALP, ascorbic acid phosphate (AAP) can be transformed into ascorbic acid (AA), the later can etch MnO2 to recover the fluorescence of the AuNCs. Based on optimal conditions, the proposed assay showed 220-fold sensitivity improvement in comparison with conventional monoclonal antibody-based ELISA. The recovery test of urine samples and the validation by standard HPLC-FLD demonstrated the proposed assay was an ideal tool for screening 1-NAP and provided technical support for the monitoring of carbaryl exposure.

Development of a fluorescence polarization immunoassay for the detection of melamine in milk and milk powder.

A fluorescence polarization immunoassay (FPIA) based on a polyclonal antibody was developed for the determination of melamine in milk. To obtain an antibody with improved sensitivity and specificity, 6-hydrazinyl-1,3,5-triazine-2,4-diamine was coupled to bovine serum albumin and used as the immunogen for the rabbit immunization. Three fluorescein-labeled melamine tracers with different structures and spacer bridges were synthesized. The structural effect of the tracers on the assay characteristics was investigated. 6-(4,6-Diamino-1,3,5-triazin-2-ylamino)-N-(2-(3-(3',6'-dihydroxy-3-oxo-2,3-dihydrospiro[indene-1,9'-xanthene]-5-yl)thioureido)ethyl)hexanamide demonstrated better sensitivity than 5-(2-(4,6-diamino-1,3,5-triazin-2-yl)hydrazinecarbothioamido)-2-(6-hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid and 3-(4,6-diamino-1,3,5-triazin-2-ylthio)-N-(2-(3-(3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthene]-5-yl)thioureido)ethyl)propanamide. The limit of detection (10% inhibition) of the FPIA was 9.3 ng mL(-1) and the IC(50) (50% inhibition) value was 164.7 ng mL(-1). The antibody in the FPIA showed 21.2% cross-reactivity to the fly-killing insecticide cyromazine, but had no cross-reactivity to other natural structurally related compounds. Recoveries, measured in spiked milk and milk powder samples, ranged from 79.4 to 119.0%. Milk samples fortified with melamine were analyzed by this method and confirmed by high-performance liquid chromatography-mass spectrometry. Excellent recoveries and correlation with spiked levels were observed, suggesting that this immunoassay could be applied to the screening of melamine residues in milk and milk powder after a simple dilution procedure.

[Application value of 3T 1H-magnetic resonance spectroscopy in diagnosing tumors of bone and soft tissue].

OBJECTIVE: To study benign and malignant bone and soft tissue tumors with 1H-magnetic resonance spectroscopy (1H-MRS) at 3 Tesla MR scanner and assess the value of 1H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. METHODS; Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. 1H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 1H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds (Cho) opposite to the creatine (Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies. RESULTS: 1H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3.13 +/- 0.9 and 1.34 +/- 1.02, respectively (P = 0.02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94%, 80%, and 90%, respectively, in diagnosing malignancies. CONCLUSIONS: The increased Cho level, as measured by 1H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. 1H-MRS can be an important supplement to the conventional magnetic resonance imaging.

[Analysis of curative effect for 21 recurrent soft-tissue sarcoma].

OBJECTIVE: To summarize the effect of the surgery for recurrent soft-tissue sarcoma, and evaluate the treatment strategies. METHODS: The curative effect of 21 cases of recurrent soft-tissue sarcomas from January 2005 to March 2011 is analyzed. RESULTS: In 21 cases, 7 cases were amputated, 12 cases were ampliative resection and 2 cases were marginal excision. The 4 cases were recurrent, metastasis and dead, 1 cases were recurrent and live with tumor, 1 cases had metastasis and live with tumor. CONCLUSIONS: Appropriate enough surgery margine can prevent the local recurrence, and complete removal of the tumor and comprehensive radiation and chemotherapy treatment of recurrent soft tissue tumor is the key to success.

Highly specific nanobody against herbicide 2,4-dichlorophenoxyacetic acid for monitoring of its contamination in environmental water.

2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, is a small organic chemical pollutant in the environment. To develop a nanobody-based immunoassay for monitoring trace levels of 2,4-D, a step-wise strategy for the generation of nanobodies highly specific against this small chemical was employed. Firstly, we synthesized three novel haptens mimicking 2,4-D and assessed their influence on the sensitivity and specificity of the existing antibody-based assay. Polyclonal antibodies (pAb) from rabbits showed good sensitivity and moderate specificity for 2,4-D, pAb from llama based on selected haptens showed similar performance when compared to those from rabbits. Secondly, nanobodies derived from llama were generated for 2,4-D by an effective procedure, including serum monitoring and one-step library construction. One nanobody, NB3-9, exhibited good sensitivity against 2,4-D (IC50 = 29.2 ng/mL) had better specificity than the rabbit pAb#1518, with no cross-reactivities against the 2,4-D analogs tested. Thirdly, one-step fluorescent enzyme immunoassay (FLEIA) for 2,4-D based on a nanobody-alkaline phosphatase (AP) fusion was developed with IC50 of 1.9 ng/mL and a linear range of 0.4-8.6 ng/mL. Environmental water samples were analyzed by FLEIA and LC-MS/MS for comparison, and the results were consistent between both methods. Therefore, the proposed step-wise strategy from hapten design to nanobody-AP fusion production was successfully conducted, and the resulting nanobody based FLEIA was demonstrated as a convenient tool to monitor 2,4-D residuals in the environment.

Enhanced Non-Toxic Immunodetection of Alternaria Mycotoxin Tenuazonic Acid Based on Ferritin-Displayed Anti-Idiotypic Nanobody-Nanoluciferase Multimers.

The non-toxic immunoassay for mycotoxins is being paid more attention due to its advantages of higher safety and cost savings by using anti-idiotype antibodies to substitute toxins. In this study, with tenuazonic acid (TeA), a kind of highly toxic Alternaria mycotoxin as the target, an enhanced non-toxic immunoassay was developed based on the ferritin-displayed anti-idiotypic nanobody-nanoluciferase multimers. First, three specific ß-type anti-idiotype nanobodies (AId-Nbs) bearing the internal image of TeA mycotoxin were selected from an immune phage display library. Then, the AId-Nb 2D with the best performance was exploited to generate a nanoluciferase (Nluc)-functionalized fusion monomer, by which a one-step non-toxic immunodetection format for TeA was established and proven to be effective. To further improve the affinity of the monomer, a ferritin display strategy was used to prepare 2D-Nluc fusion multimers. Finally, an enhanced bioluminescent enzyme immunoassay (BLEIA) was established in which the half maximal inhibitory concentration (IC50) for TeA was 6.5 ng/mL with a 10.5-fold improvement of the 2D-based enzyme-linked immunosorbent assay (ELISA). The proposed assay exhibited high selectivities and good recoveries of 80.0-95.2%. The generated AId-Nb and ferritin-displayed AId-Nb-Nluc multimers were successfully extended to the application of TeA in food samples. This study brings a new strategy for production of multivalent AId-Nbs and non-toxic immunoassays for trace toxic contaminants.

[Release kinetics of methotrexate loaded calcium phosphate cement and histological evaluation of the osteogenesis in rabbits].

OBJECTIVE: To observe the release kinetics of methotrexate-loaded calcium phosphate cement (MTX-CPC) implanted in vivo and histologically investigate its resorption and osteogenesis. METHODS: MTX-CPC consisting of 1% methotrexate (MTX) (weight/weight) was pre-set and implanted into femoral muscles of 24 New Zealand rabbits. The in vivo MTX release kinetics was determined on the 1st, 2nd, 5th, 10th, 15th, 20th, 25th, and 30th post-implantation day. The local concentrations and the residual percentage of MTX were determined. Then the pre-set MTX-CPC was implanted into femoral condyle. Calcium phosphate cement (CPC) without MTX was used as a control. The femurs were harvested at the 1st day and the 1st, 3rd, and 6th month and examined by X ray. Then histomorphometric analyses including percentage of newly formed bone and amount of osteoblast and osteoclast were performed. RESULTS: The MTX release kinetics in vivo confirmed that MTX-CPC was a monolithic matrix system, with a burst effect in the initial stage and a sudden drop thereafter. The local concentration of the released MTX was 0.372 µg/ml on the 30th post-implantation day; with a concentration higher than the effective concentration,the incorporated MTX was expected to be continuously released over the following 2-3 months. Both MTX-CPC and CPC showed good biodegradability and osteoconduction. Although the release of MTX had an inhibitory effect on osteogenesis, especially in the initial stage, the area of newly formed bone, the amount of osteoblasts, and the amount of osteoclasts were not significantly different between MTX-CPC group and CPC group on the 6th post-implantation month. CONCLUSIONS: MPX-CPC system is an effective drug delivery system. Both MTX-CPC and CPC has good biodegradability and osteoconduction. Therefore,MTX-CPC system can be an ideal material for filling defects and controlling local recurrence.

One-Step Reconstruction with a Novel Suspended, Modular, and 3D-Printed Total Sacral Implant Resection of Sacral Giant Cell Tumor with Preservation of Bilateral S1-3 Nerve Roots via a Posterior-Only Approach.

OBJECTIVE: To investigate the efficacy and safety of spinopelvic reconstruction based on a novel suspended, modular, and 3D-printed total sacral implant after total piecemeal resection of a sacral giant cell tumor (SGCT) with the preservation of bilateral S1-3 nerve roots via a posterior-only approach. METHODS: Five patients who had undergone total piecemeal resection of SGCT involving upper sacral segments (S1 and S2 ) and the midline with the preservation of bilateral S1-3 nerve roots via a posterior-only approach between September 2017 and July 2018 were retrospectively reviewed. A novel suspended, modular, and 3D-printed total sacral implant had been used for reconstruction. This series included two female and three male patients, with a mean age of 42.2 years (range, 31-53 years). Surgical time, blood loss, complications, preoperative and postoperative neurological function, instrumentation failure, and local control were presented and analyzed. RESULTS: All patients underwent the operation without death or serious complications. The implant was installed on the defect, connecting the ilium and lumbar vertebrae, and fixed with a screw-rod system up to the level of L3-4 or L4-5 . The mean operative time was 502 min (range, 360-640 min) and the mean operative blood loss 4400 mL (range, 3000-7000 mL). The mean follow-up was 15 months. After the operation, pain was significantly relieved, and the patients resumed walking as early as 2 weeks later. The patients showed no neurogenic bladder dysfunction and no fecal incontinence or gait disturbance. Wound healing was poor in one patient. Patients recovered well without evidence of local recurrence. No implant failures or related clinical symptoms were detected during follow up. Satisfactory bone ingrowth and osseointegration at the bone-implant junctions was found in follow-up CT. CONCLUSION: Although technically challenging, it is feasible and safe to use a suspended, modular, and 3D-printed implant for reconstruction after total piecemeal resection with the preservation of bilateral S1-3 nerve roots in patients with SGCT. We believe that this implant can be applied to sacral reconstruction in a wide variety of diseases.

[A method of exosomes extraction from large-volume cell perfusate].

Objective: To establish an efficient method for extracting exosomes from large-volume cell perfusate. Methods: EA.HY926, an immortalized cell line produced by the hybridization of human umbilical vein endothelial cells and human lung adenocarcinoma cell line A549, was cultured with M199 culture medium containing 10% fetal bovine serum. Flexcell STR-4000 parallel plate flow chamber system was employed to apply shear stress to EA.HY926. And then the perfusate was collected. The cell debris was removed by centrifugation. The supernatant was freeze-dried into the dry powder and was resuspended by small-volume medium. The dialysis was used to desalt and purify the suspension. The exoEasy Maxi Kit was used to extract the exosomes. The morphology of exosomes was observed by electron microscopy. The size of exosomes was detected by nanometer particle size analyzer. The activity of exosomes was detected by PKH26 staining. BCA protein quantification method was used to detect the protein concentration of exosomes. The expressions of exosomal specific proteins CD9 and CD81 were detected by Western blot. The quantitative RT-PCR was used to detect the expression of related genes in the exosomes. Results: The exosomes extracted by this method were uniform in size, showing a typical and complete vesicle-like structure. The particle size was concentrated at 30～150 nm, and the peak value was at 97.63 nm, indicating that the size was appropriate and the purity was high. Moreover, exosomes-specific protein CD9 and CD81 were expressed. PKH26 could bind to the membranous structure of exosomes and exosomes could be efficiently taken up by cells. Endothelial cells-associated CD31, vWF mRNA, and microRNA molecules such as miR-126, miR-21, miR-155 were expressed in exosomes secreted by EA.HY926. Conclusion: This method can effectively extract structurally intact, high-concentration, high-quality exosomes from large-volume cell perfusate.

[Changes of 3-tesla 31P-MR spectroscopy of bone and soft tissue tumors].

OBJECTIVE: To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors. METHODS: 41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr. RESULTS: The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05). CONCLUSION: Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.

Design of Novel Haptens and Development of Monoclonal Antibody-Based Immunoassays for the Simultaneous Detection of Tylosin and Tilmicosin in Milk and Water Samples.

In this work, a monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (icELISA) was established to detect tylosin and tilmicosin in milk and water samples. A sensitive and specific monoclonal antibody was prepared by rational designed hapten, which was achieved by directly oxidizing the aldehyde group on the side chain of tylosin to the carboxyl group. Under the optimized conditions, the linear range of icELISA for tylosin and tilmicosin were 1.3 to 17.7 ng/mL and 2.0 to 47.4 ng/mL, with half-maximal inhibition concentration (IC50) values of 4.7 and 9.6 ng/mL, respectively. The cross-reactivity with other analogues of icELISA was less than 0.1%. The average recoveries of icELISA for tylosin and tilmicosin ranged from 76.4% to 109.5% in milk and water samples. Besides, the detection results of icELISA showed good correlations with HPLC-MS/MS. The proposed icELISA was satisfied for rapid and specific screening of tylosin and tilmicosin residues in milk and water samples.

Knee reconstruction with preservation of the meniscus in tibial giant cell tumor.

UNLABELLED: Giant cell tumor of bone sometimes is an aggressive benign skeletal tumor. Historically, curettage and bone grafting have a high recurrence with satisfactory function whereas wide resection has a reduced recurrence rate with compromise of limb function. Thus, maintaining joint function and achieving adequately wide resection introduces contradictory surgical goals. We developed a method for achieving both goals for giant cell tumors located in only one lateral plateau of the proximal tibia. We reconstructed 13 knees preserving the meniscus and reconstructing the tibial plateau with an iliac plate autograft after resection of a giant cell tumor involving one tibial plateau. Four patients had primary tumors and nine had recurrences after curettage. The minimum followup was 5 years (mean, 9.1 years; range, 5-12.75 years). We used the system of Enneking et al. to evaluate function. One patient had recurrence and underwent prosthesis replacement. No patient experienced collapse, instability, or pain, and knee function was restored to near normal. The mean functional score was 95%. While resecting the tumor, the normal anatomic structures of the knee can be preserved or restored in many patients. This method can be used in selected patients to reconstruct the knee after resection of tumors involving one tibial plateau. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

[Application of the proximal tibiofibular joint resection on the limb salvage for osteosarcoma of the proximal tibia].

OBJECTIVE: To evaluate the proximal tibiofibular joint resection on the limb salvage for osteosarcoma of the proximal tibia. METHODS: Between August 1995 and January 2004, 11 patients with osteosarcoma of proximal tibia and tibiofibular joint involved underwent resection and endoprosthetic proximal tibial replacement. Seven patients were male and 4 were female. The patients ranged in age from 14 to 23 years (mean 18 years). The surgical stage were IIB. RESULTS: The follow-up period varied from 2 to 9 years (mean 59 months). Three patients died of pulmonary metastases, 1 patient was still alive with pulmonary metastasis, 1 patient underwent amputation for local recurrence. There was 1 early skin necrosis, 2 transient palsy of the common peroneal nerve, and 2 thrombus of lower limb vein. The mean postoperative Musculoskeletal Tumor Society score of the knee joint was 70% (range 55% - 86%), the mean postoperative range of motion was 85 degrees (range 0 degrees - 120 degrees ), and the extensor lag varied from 0 degrees to 20 degrees . CONCLUSIONS: Limb salvage for osteosarcoma of the proximal tibia with proximal tibiofibular joint resection and custom-made prosthesis reconstruction has had excellent results, however, the prevention and treatment of relevant complications should be given more attention.

Transnasal Endoscopic Biopsy Approach to Atlas Tumor with X-ray Assisted and Related Radiographic Measure.

OBJECTIVE: To develop an endoscopic transnasal approach to atlas tumors and study its practicability. METHODS: This article comprises two components: an illustrative case report and observational data on 50 volunteers. As to the case report, a 34 year old man presented with occipital pain for more than 3 months and underwent systematic investigation in Qilu Hospital of Shandong University. CT and MRI scans showed bony destruction in the craniovertebral junction (CVJ) suggestive of tumor. Via an endoscopic transnasal approach to the suspected atlas tumor through the inferior nasal meatus, a Gallini biopsy needle was used to obtain tissue for examination. The procedure was performed endoscopically with double orientation X-ray guidance and coaxial technology after establishing the shortest distance for the biopsy track and range of target tissue and was assisted by manual palpation. As to the observational data, 50 volunteers underwent atlas-related morphometric image measurement using gemstone CT equipment. Biopsy track angles, range for biopsy of the atlas and biopsy track distances were measured by a blinded operator on CT images. CASE REPORT: pathological examination of the biopsy resulted in diagnosis of a chordoma. There were no complications such as bleeding, infection or spinal cord injury. One month later, the patient underwent tumor resection and reconstruction in other hospital and the diagnosis of chordoma was confirmed by pathological examination of the resected specimen. Observational data: measurements obtained from CT scans of the 50 volunteers were as follows. Biopsy track angles: mean leaning inside angle 3.53° ± 0.39° and mean posterior slope angle 13.05° ± 1.39°. Range for atlas biopsy: transverse diameter 11.84 ± 1.24 mm and longitudinal diameter 9.67 ± 0.90 mm. Biopsy track distances: from atlas to nostril, and to anterior and posterior edges of the inferior turbinate mucosa were 94.52 ± 5.03 mm, 78.21 ± 4.63 mm, and 33.51 ± 3.13 mm, respectively. CONCLUSIONS: An endoscopic transnasal approach enables biopsy and diagnosis of tumors in the anterior arch of the atlas. Relevant measurements were obtained by assessing CT scans of 50 volunteers to assist operators to determine the effective and safe range for transnasal atlas biopsy.