Nanocrystalline Alumina-Zirconia-Based Eutectic Ceramics Fabricated with High-Energy Beams: Principle, Solidification Techniques, Microstructure and Mechanical Properties.

Nanocrystalline alumina-zirconia-based eutectic ceramics fabricated with high-energy beams and composed of ultrafine, three-dimensionally entangled, single-crystal domains are a special category of eutectic oxides that exhibit exceptionally high-temperature mechanical properties, such as strength and toughness as well as creep resistance. This paper aims to provide a comprehensive review on the basic principles, advanced solidification processes, microstructure and mechanical properties of alumina-zirconia-based eutectic ceramics, with particular attention to the status of the art on a nanocrystalline scale. Some basic principles of coupled eutectic growth are first introduced based on previously reported models, followed by concise introduction of solidification techniques and the control strategy of solidification behavior from the processing variables. Then, the microstructural formation of nanoeutectic structure is elucidated with regard to different hierarchical scales, and mechanical properties such as hardness, flexural and tensile strength, fracture toughness and wear resistance are discussed in detail for a comparative study. Nanocrystalline alumina-zirconia-based eutectic ceramics with unique microstructural and compositional characteristics have been produced with high-energy beam-based processes, and in many cases, promising improvements in mechanical performance have been reported as contrasting with conventional eutectic ceramics.

Cranium and Vertebral Column of Xingxiulong chengi (Dinosauria: Sauropodomorpha) from the Early Jurassic of China.

The Lower Jurassic Lufeng Formation in Yunnan Province of southwestern China provides one of the most abundant records of sauropodomorphs in the world. However, most of them have not been fully described. Xingxiulong chengi is among the most complete non-sauropodan sauropodomorphs ever discovered from Lufeng Formation and is represented by three partial skeletons. Here, we provide a detailed osteological description of its axial skeleton, including both the cranial and postcranial elements, and compare its anatomy with that of other known non-sauropodan sauropodomorphs. In general, the cranium of Xingxiulong is more similar to those of more basal sauropodomorphs than to sauropodiforms, as evidenced by features such as an only slightly concave dorsal margin of the postorbital, a caudally placed rostral margin of the infratemporal fenestra not extending below the orbit, and long and slender basipterygoid processes divergent from each other at an angle of approximately 80 degrees. However, its postcranial axial skeleton possesses some unique or relatively derived features among basal sauropodomorphs, such as four sacral vertebrae and caudal dorsal vertebrae with laterally expanded neural spine tables. This provides future workers with a reassessment of non-sauropodan sauropodomorphs through the lens of Xingxiulong chengi, which will serve to increase our knowledge on the anatomy, phylogeny, and furthermore, evolution of sauropodomorph dinosaurs. Anat Rec, 303:772-789, 2020. © 2019 American Association for Anatomy.

Microarc Oxidation Coating Combined with Surface Pore-Sealing Treatment Enhances Corrosion Fatigue Performance of 7075-T7351 Al Alloy in Different Media.

Rotating bending fatigue tests have been performed to evaluate the corrosion fatigue performance and its influence factors of 7075-T7351 Al alloy in different media, namely air and a 5.0 wt % NaCl aqueous solution. All samples were coated by microarc oxidation (MAO) coating technology; some samples were followed by an epoxy resin pore-sealing treatment. Microscopic analyses of the surfaces and fracture cross-sections of samples were carried out. The results reveal that the sample with a MAO coating of 10 µm thickness and pore-sealing treatment by epoxy resin possesses optimal corrosion fatigue performance in the different media. The MAO coating with a pore-sealing treatment significantly improves the corrosion fatigue limit of 7075-T7351 Al alloy.

A new basal sauropodiform dinosaur from the Lower Jurassic of Yunnan Province, China.

The Lufeng Formation in Lufeng Basin of Yunnan Province, southwestern China preserves one of the richest terrestrial Lower Jurassic vertebrate faunas globally, especially for its basal sauropodomorphs, such as Lufengosaurus and Yunnanosaurus. Here we report a new taxon, Xingxiulong chengi gen. et sp. nov. represented by three partial skeletons with overlapping elements. Xingxiulong possesses a number of autapomorphies, such as transversely expanded plate-like summit on top of the neural spine of posterior dorsal vertebrae, four sacral vertebrae, robust scapula, and elongated pubic plate approximately 40% of the total length of the pubis. Phylogenetic analysis resolves Xingxiulong as a basal member of Sauropodiformes, and together with another two Lufeng basal sauropodiforms Jingshanosaurus and Yunnanosaurus, they represent the basalmost lineages of this clade, indicating its Asian origin. Although being relatively primitive, Xingxiulong displays some derived features normally occurred in advanced sauropodiforms including sauropods, such as a four sacral-sacrum, a robust scapula, and a pubis with elongated pubic plate. The discovery of Xingxiulong increases the diversity of basal sauropodomorphs from the Lufeng Formation and indicates a more complicated scenario in the early evolution of sauropodiforms.

Immunochemotherapy for primary central nervous system lymphoma with rituximab, methotrexate, cytarabine and dexamethasone: Retrospective analysis of 18 cases.

The incidence of primary central nervous system lymphoma (PCNSL) has increased in the last two decades and the clinical research regarding the treatment for PCNSL patients has also increased. However, the optimal induction chemotherapy has not been fully established. In the present retrospective study, the aim was to analyze the outcome in PCNSL patients treated with the combination of rituximab, methotrexate (MTX), cytarabine (Ara-C) and dexamethasone (R-MAD). Eighteen patients from Beijing Tiantan Hospital (Beijing, China) between January 2010 and March 2014 were newly diagnosed with PCNSL [diffuse large B-cell lymphoma (DLBCL) type] and received R-MAD as first-line treatment. The dosage was as follows: 375 mg/m2 rituximab was administered on day 0, 3.5 g/m2 MTX was administered on day 1, 1 g/m2 Ara-C was administered on day 2 and 10 mg dexamethasone was administered on days 1-3, every 3 weeks. After 6 cycles, the overall response rate was 94.5%. Ten (55.6%) patients achieved complete response (CR), 7 (38.9%) achieved partial response (PR) and 1 (5.6%) had progressive disease (PD). Patients were followed up from the start of the treatment, median 24.2 months (range 6-48). The overall survival (OS) rate was 94.5% and progression-free survival rate was 94.5%. The median OS was 22 months (95% confidence interval, 19.4-24.6). The high level of serum lactate dehydrogenase (LDH) concentration was associated with a poor outcome. Among 5 patients with an abnormally high LDH concentration, 1 achieved CR, 3 had PR and 1 had PD. None of the patients experienced any grade 4 toxicity. These results indicated that the R-MAD immunochemotherapy regimen is effective in PCNSL patients without serious toxicity. A prospective investigation with more patients should be administered in order to understand the more accurate effect of the regimen.

The first well-preserved coelophysoid theropod dinosaur from Asia.

Coelophysoid dinosaurs represent the earliest major radiation of neotheropods. These small-to-medium-sized agile bipeds lived throughout much of Pangaea during the Late Triassic-arly Jurassic. Previously reported coelophysoid material from Asia (excluding the Gondwanan territory of India) is limited to two specimens that comprise only limb fragments. This paper describes a new genus and species of coelophysoid, Panguraptor lufengensis, from the Lower Jurassic Lufeng Formation of Yunnan Province, China. The new taxon is represented by a well-preserved skeleton, including the skull and lower jaw, the presacral vertebral column and partial ribs, the right scapula, a partial forelimb, part of the pelvic girdle, and an almost complete hind limb. It is distinguished from other coelophysoid theropods by the unique combination of the following three character states: 1) diagonal (rostrodorsal-caudoventral) ridge on lateral surface of maxilla, within antorbital fossa, 2) elliptical, laterally facing fenestra caudodorsal to aforementioned diagonal ridge, and 3) hooked craniomedial corner of distal tarsal IV. Cladistic analysis recovers Panguraptor lufengensis deeply nested within Coelophysoidea as a member of Coelophysidae, and it is more closely related to Coelophysis than to "Syntarsus". Panguraptor represents the first well-preserved coelophysoid theropod dinosaur from Asia, and provides fresh evidence supporting the hypothesis that terrestrial tetrapods tended to be distributed pan-continentally during the Early Jurassic.

[Mixed craniopharyngioma: long-term results after gamma knife combined with stereotactic brachytherapy].

OBJECTIVE: To evaluate the long-term results of combination treatment with Gamma Knife radiosurgery and stereotactic intracavitary brachytherapy for mixed cystic and solid craniopharyngiomas. METHODS: Sixty-seven consecutive patients with mixed cystic and solid craniopharyngioma treated by Gamma Knife radiosurgery combined with stereotactic brachytherapy from October 1996 to December 2005 were selected for retrospective analysis. The inclusion criterion was the patients who survived for at least 5 years after combined treatment. There were 39 male and 28 female patients and the mean age was 31.5 years (ranged from 3 to 70 years). The clinical evaluations including neurological, neuro-ophthalmological, and neuro-endocrinological examinations, assessment of comprehensive quality of life and neuroimaging examinations were performed periodically. The actuarial survival rates and the mean survival time were calculated by using Kaplan-Meier product limit method. The rates were compared using the χ(2) test. RESULTS: Follow-up period varied from 60 to 168 months, with an average of 114 months. The tumor response rate gained from combination treatment with Gamma Knife radiosurgery and stereotactic intracavitary brachytherapy for predominantly solid and cystic craniopharyngiomas were 10/12 and 90.9% respectively, and 89.6% in all. Mean survival after combination treatment was (110 ± 9) months. The mean survival of patients with predominantly solid and cystic craniopharyngioma were (97 ± 12) months and (120 ± 14) months and the actuarial 10-year survival rates were 7/12 and 69.1%. There was no statistics difference in tumor response rate and 10-year survival rate between 2 groups of patients with predominantly solid and cystic craniopharyngioma. The actuarial 5-, 6-, 7-, 8-, 9- and 10-year survival rates were 90.5%, 85.7%, 83.3%, 76.4%, 69.4% and 60.0% respectively. The decreased visual acuity had improved in 68.3% at 6 months postoperatively and in 70.0% in long term results. Comprehensive quality of life in long term follow-up of 67 patients was excellent in 28 cases(41.8%), good in 19 cases(28.4%), fair in 17 cases(25.4%) and poor in 3 cases(4.5%), respectively. The side effects that occurred 6 to 12 months after treatment were worsening of visual acuity (4 patients), dysfunction of hypothalam (4 patients) and third nerve palsy was found in 1 patents 5 years after treatment. The rate of complications was 13.4%. CONCLUSION: Combination treatment with Gamma Knife radiosurgery and stereotactic intracavitary brachytherapy is highly effective and safety in the treatment of mixed cystic and solid craniopharyngiomas.

Previously unrecognized ornithuromorph bird diversity in the Early Cretaceous Changma Basin, Gansu Province, northwestern China.

Here we report on three new species of ornithuromorph birds from the Lower Cretaceous Xiagou Formation in the Changma Basin of Gansu Province, northwestern China: Yumenornis huangi gen. et sp. nov., Changmaornis houi gen. et sp. nov., and Jiuquanornis niui gen. et sp. nov.. The last of these is based on a previously published but unnamed specimen: GSGM-05-CM-021. Although incomplete, the specimens can be clearly distinguished from each other and from Gansus yumenensis Hou and Liu, 1984. Phylogenetic analysis resolves the three new taxa as basal ornithuromorphs. This study reveals previously unrecognized ornithuromorph diversity in the Changma avifauna, which is largely dominated by Gansus but with at least three other ornithuromorphs. Body mass estimates demonstrate that enantiornithines were much smaller than ornithuromorphs in the Changma avifauna. In addition, Changma enantiornithines preserve long and recurved pedal unguals, suggesting an arboreal lifestyle; in contrast, Changma ornithuromorphs tend to show terrestrial or even aquatic adaptions. Similar differences in body mass and ecology are also observed in the Jehol avifauna in northeastern China, suggesting niche partitioning between these two clades developed early in their evolutionary history.

The role of mitochondrial calcium uniporter in neuroprotection in traumatic brain injury.

The alteration in cellular Ca(2+) homeostasis is one of the key mechanisms contributing to secondary neuronal damage and altered physiology during the process of traumatic brain injury (TBI). However, there is considerable uncertainty about the efficacy of calcium channel blockers in randomized, controlled, clinical trials. In the physiological condition, cellular Ca(2+) homeostasis occurs through repetitive bursts of rising intracellular Ca(2+) that, sometimes are referred to as Ca(2+) oscillations. Mitochondria are intimately involved in the spatiotemporal tuning of cellular Ca(2+) signaling mainly through mitochondrial Ca(2+) uniporter (MCU). Excessive Ca(2+) uptake by the mitochondria through MCU is a key event in mitochondrial dysfunction and cell death in TBI. Selective inhibition of MCU has showed a promising cardioprotection and neuroprotection effect in many preclinical studies. Based on these preclinical results, the selective inhibition of MCU may be a new strategy for neuroprotection in TBI patients.

[Magnetic resonance spectroscopy-guided stereotactic biopsy for brain lesion].

OBJECTIVE: To study the clinical value of magnetic resonance spectroscopy (MRS) image in stereotactic biopsy for brain lesion. METHODS: From April 2008 to April 2010, 126 cases (72 male and 54 female, aged from 10 to 82 years, mean 45 years) of brain lesion which were difficult to diagnose were divided into two groups by random number table, 62 cases were executed for MRI-guided frameless stereotactic biopsy (MRI group), 64 cases were executed for MRI and MRS-guided frameless stereotactic biopsy (MRS group). Operation used MRI and Three-dimensional MRS image to locate, and used frameless CAS-R-2 robots to carry out the positioning operating. RESULTS: No surgery-related deaths and infections. Pathological diagnosis was 106 cases of brain tumors, 6 cases of inflammatory disease, 4 cases of tumor-like demyelinating disease and multiple sclerosis, 3 cases of neurodegenerative disease, 7 cases failed to obtain positive pathological diagnosis. The total rate of positive diagnosis was 94.4%, the positive rate in MRS-guided stereotactic biopsy group was 98.4% (63/64), the positive rate of conventional MRI-guided biopsy group was 90.3% (56/62), and there was statistically significant difference between the two groups (χ(2) = 3.92, P = 0.047). Four cases presented with postoperative complications, the complication rate was 3.2% (4/126); the complications were cerebral hemorrhage associated with aphasia, epilepsy, subcutaneous hematoma, gastrointestinal bleeding, which were improved after treatment. CONCLUSIONS: MRS-guided stereotactic biopsy group has a higher positive rate than MRI-guided stereotactic biopsy group, indicating that this method can improve the positive rate of diagnosis, and thus will help to formulate treatment plan for brain lesion.

[Preparation of anti-ASNS monoclonal antibody and detection of ASNS expression in tumor].

AIM: To prepare and characterize monoclonal antibodies against ASNS for the research of ASNS function. METHODS: To induce the expression of the fusion protein MS2-ASNS, Hybridomas were generated by the fusion with Sp2/0 myelomas and spleen cells, which were obtained from mice immunized with MS2-ASNS recombinant proteins. The specificity and titer of mAb were identified by ELISA methods, and then used to detect the affinity of ASNS in cancer cells by Western blot. The expression of ASNS was detected in some cancer lines and tissues by IHC. RESULTS: Two hybridoma cell lines F4-15 and F4-16, which stably secret anti-ASNS mAbs were produced. Both cell lines produce IgG2a monoclonal antibody. ELISA demonstrated that anti-ASNS mAbs had high specificity and titer. The titers of anti-ASNS mAbs produced by hybridoma cell lines were up to 1:5×10(5);. Western blot demonstrated that ASNS was expressed in some cancer lines, including human lymphoma cell line K562 and cervical cancer cell line HeLa. The expression of ASNS was also detected by IHC in several tumor cell lines, such as stomach cancer cell line SGC-7901 and liver cancer cell lines SMMC-7721, BEL-7402, HepG2 as well as lung and esophageal carcinoma tissue. CONCLUSION: The monoclonal antibodies against ASNS have been successfully prepared, which provides a tool for the following research of nasal type NK/T cell lymphoma.

[Clinical experience of stereotactic biopsy for the brain lesions].

OBJECTIVES: To investigate the methodology of diversified advanced image-guided stereotactic biopsy for the brain lesions, and its diagnostic significance and experience in nervous system diseases. METHODS: Retrospectively reviewed 1187 cases of brain lesions underwent image-guided stereotactic biopsy from December 1987 to January 2009. There were 694 male (58.5%) and 493 female (41.5%) patients, aged from 1 to 85 years (average 39.7 years). There were 607 cases in CT-guided, including positron emission computed tomography (PET) guided stereotactic biopsy; 580 cases in MRI-guided, including proton magnetic resonance spectroscopy ((1)H-MRS) guided stereotactic biopsy. Routine frame was used in 726 cases and frameless stereotactic biopsy in 461 cases, including neuroendoscopic biopsy in 28 cases, guided by computer assisted surgery (CAS) computer-assistant robot. In the early 450 cases, CT/MRI images films were employed to measure the coordinates of the target by hand, while in the late 737 cases, computer-assistant planning software rebuilt the CT/MRI images and figured out the optimal neurosurgical path for biopsy. RESULTS: The positive diagnosis rate of biopsy was 97.4%, 983 (82.8%) cases were diagnosed pathologically as brain tumors, and 173 (14.6%) cases as non-tumor diseases. The tumors mainly including neuroglioma, metastatic tumor, primary central nervous system lymphoma and germ cell tumors. In non-tumor diseases, mainly including multiple sclerosis, tumefactive demyelinating lesion, neurodegenerative disease, inflammation and parasite. The biopsy operation caused small hematoma without neurological deficits in 20 cases (1.7%), and caused large hematoma (> 10 ml) which need neurosurgical treatment (catheterization or craniotomy evacuation of hematoma) in 9 cases (0.8%). Hemorrhage associated with biopsy caused 3 cases (0.3%) death. There were no severe intracranial infection cases. CONCLUSIONS: The stereotactic biopsy with advanced image-guided technique represents a safe, reliable and minimally invasive method for pathological diagnosis of intracranial lesions. Moreover, the developments of biochemical imaging gives a new concept to the stereotactic biopsy.

[The clinical features, neuroimaging findings and pathological characteristics of 26 patients with pathologically proven tumor-like inflammatory demyelinating diseases].

OBJECTIVE: To summarize the clinical features, neuroimaging findings and pathological characteristics of 26 patients with tumor-like inflammatory demyelinating diseases (TIDD) confirmed by histopathology for better diagnosis and differential diagnosis. METHODS: The clinical features, neuroimaging findings and pathological characteristics of 26 patients (14 male, 12 female) with pathologically proven TIDD (24 brain-type and 2 spinal cord-type) were retrospectively analysed. RESULTS: The mean onset age was 6 - 69 (36.7 ± 13.8) years. Twenty-one patients had good prognosis with a median followed-up duration of 51.0 months. Two patients were died of post-operative complication and pulmonary infection respectively and the remaining 3 patients were lost to followed up. The TIDD patients almost showed monophasic clinical setting. Headache, indifference accompanied with hypothesis were the commonest initial symptoms. The positive or abnormal rates of cerebrospinal fluid oligoclonal bands (OCB) and myelin basic protein (MBP) in TIDD patients were high. The involvements of bilateral and multi-lesions were commonest in TIDD (61.5%, 65.4% respectively). Twenty-two patients with CT unenhanced scanning showed hypodense lesions. Long T(1) and long T(2) signal intensity was showed on MRI and most cases appeared round-like lesion in shape. According to the shape of enhancement of the 23 patients performed with contrast agents, 11 were shown with open-ring enhancement, 4 cases (including 2 accompanied with open-ring enhancement) with complete ring enhancement, 3 with asymmetrical dotted enhancement, 2 with diffused even enhancement, and no enhancement was seen in the other 6. Furthermore, 14 cases with DWI and 12 with FLAIR all appeared hyperdensity. The typical pathological changes were demyelinating, perivascular inflammatory cells infiltration and reactive gliosis. Occasionally, the Creutzfeldt cells were also found in brain tissue of some patients. CONCLUSIONS: TIDD is a distinct demyelinating disease entity. In spite of being apt to be confused with the neoplasm in brain and spinal cord. TIDD has its own-features, for example, OCB is frequently positive in patients with TIDD and the level of MBP may be significantly increased. Furthermore, the involvements of bilateral and multi-lesions are the common in TIDD, and most cases showed open-ring enhancement or complete rim enhancement on MRI. In addition, all cases present hypodense lesions on unenhanced CT and patients with hyperdense seemed not to be considered as TIDD.

[Anatomic study of the medial pedis composite flaps with saphenous nerve and tendon and its application].

OBJECTIVE: To investigate the anatomy of the medial pedis composite flaps with saphenous nerve and tendon and its application in the repair of tendo calcaneus and adjacent defects. METHODS: 10 cadavers (20 sides) were observed. The origin, course, size and the distribution of the medial plantar artery were studied. 12 cases with tendo calcaneus and adjacent defects were reconstructed with the medial pedis composite flaps with saphenous nerve. Donor site defects were covered with free skin graft. RESULTS: The medial plantar artery gives off deep branch [diameter (1.5 +/- 0.3) mm] and superficial branch [diameter (1.0 +/- 0.2) mm]. In 18 sides, the deep branches give off the medial branches and lateral branches. While in 2 sides, the superficial branches give off the medial branches and lateral branches with no big branches from the deep branches. There are branches of saphenous nerve and medial dorsal cutaneous nerve in the flap. All the flaps were survived. 8 cases were followed up for one months to one years. Good color, texture and function of the flaps were achieved. CONCLUSIONS: The medial pedis composite flaps with saphenous nerve can repair tendo calcaneus and adjacent defects. It is a easy and safe procedure with reliable anatomy and good results.

[Diagnosis and radiotherapy of germinomas arising in basal ganglia and thalamus].

OBJECTIVE: To summarize the clinical characteristic and radiotherapeutic effect of germinomas arising in basal ganglia and thalamus. METHODS: The clinical data of 13 cases were reviewed retrospectively. All cases were pathologic diagnosis through stereotactic biopsy. Gamma-knife or ordinary irradiation were 2 cases respectively and the combined therapy with interstitial brachytherapy as foundation were 9 cases. RESULT: All cases were male, median age of 16.1 years. Hemiparesis and ataxia were major symptoms, some cases were accompanied with precocious puberty. Imaging manifested intratumoral cystic components represented 76.9% of all lesions, calcification represented 30.8%, ipsilateral cerebral and brain stem hemiatrophy represented 46.2%, cerebral white matter invasion through internal capsule or corpus callosum represented 30.8%. One case died because of late complication and 12 cases had achieved satisfied therapeutic effect (the mean followed-up period was 40.6 months). Tumor-control were effective. CONCLUSIONS: The clinical manifestation and imaging characteristics are helpful to diagnosis. Stereotactic biopsy make the affirmatory diagnosis. Operative total-removal is impossible because of deep location, neighbour of vital structure and invasion. The combined therapy with interstitial brachytherapy was effective.

[Polyadenylation signal-deficient retroviruses transformation of human gastric epithelial GES-1 cells].

OBJECTIVE: To verify if mutated polyadenylation signal retroviruses can produce viral-host readthrough transcripts (Rth) and have the ability to transform human gastric epithelial GES-1 cells, and to discuss the new functions of retroviruses in gastric cancer related gene research. METHODS: The polyadenylation signal-deficient retrovirus vector mutated by PCR site-directed mutagenesis was used to make polyadenylation signal-deficient retroviruses by PA317 packaging cells. The GES-1 cells were infected by the viruses and selected by G418. Viral-host readthrough RNAs were checked by Northern blot. The cell growth and soft agar assay were run to test the transformed cells. RESULTS: polyadenylation signal-deficient retroviruses could be packaged by PA317 packaging cells. The viruses had the ability to infect GES-1 cells. Northern blot analysis of viral RNA from infected pools and individual G418-resistant clones demonstrated that mutation of consensus LTR polyadenylation signals generated Rth viral RNA in the infected GES-1 cells. Phenotypic analysis results showed that the GES-1 cells infected with plyadenylation signal mutant viruses tended to grow in a cluster manner. Pools of PA317 cells infected with mutant viruses were able to form colonies in soft agar with a higher efficiency than control or uninfected cells. CONCLUSION: Host readthrough transcripts generated by polyadenylation signal mutant viruses may contribute to transformation GES-1 cell phenotypes. The mutant vectors and the method described in the present work may be useful as tools to trap and identify genes involved in retroviral insertion mediated cell transformation.

[Expression of midkine fusion protein and preparation and application of its monoclonal antibodies].

AIM: To express midkine (MK) protein, prepare its monoclonal antibody (mAb), and detect its expression in tumor cells. METHODS: The human MK gene fragment was cloned from kidney cancer tissues by RT-PCR and inserted into the prokaryotic expression vector pMS-31b. The MS2-MK fusion protein was expressed in E.coli after temperature induction. The purified fusion protein was used to immunize BALB/c mice to prepare mAbs against MK by routine hybridoma technique. The Ig subclasses of the mAbs were identified by ELISA. The expression of MK in tumor cells was detected with the mAbs. RESULTS: MK gene was cloned and MS2-MK fusion protein was expressed successfully. Two hybridoma cell lines secreting anti-MK mAbs were obtained. The Ig subclass of the 2 mAbs was IgG1 and IgG2a, respectively. MK was expressed in gastric carcinoma cell line MGC803 and gastric cancer tissue. CONCLUSION: The MS2-MK fusion protein was expressed in E.coli and the mAbs against MK were pepared, which allow futher research on MK function.

Cloning of 3H11 mAb variable region gene and expression of 3H11 human-mouse chimeric light Chain.

AIM:To clone mouse anti-human gastric cancer mAb(3H11) variable genes and to construct 3H11 human-mouse chimeric antibody.METHODS: The entire VH and VL genes of anti-gastric cancer mAb 3H11 were cloned by RT-PCR method from 3H11 hybridoma cells, using 5' primers for leader sequences. The 3H11 VL gene was then inserted into human-mouse chimeric light chain expression vector and transfected into murine Sp2/0 myeloma cells.RESULTS: DNA sequence analysis indicated that the cloned genes included the whole leader sequences and the mature Ig variable region encoding sequences. After gene transfection, transient expression of chimeric light chain protein was detected.CONCLUSION: DNA sequences and transient expression indicated that the cloned gene was functional. This work laid basis for constructing 3H11 human mouse chimeric antibody in the future.