[Establishment and application of quantitative immunoassay method based on stable element labeling and inductively coupled plasma mass spectrometry].

Objective: To establish a quantitative immunoassay method based on stable element labeling and inductively coupled plasma mass spectrometry (ICP-MS) for the detection of serum amyloid A (SAA) and evaluate its performance. Methods: An immunoassay system based on sandwich method was established with magnetic bead as carrier and holmium (Ho) as element tags. The binding ratio of hydrophilic streptavidin magnetic beads and biotinylated antibody, the amount of elemental antibody, and the reaction time were optimized to choose the optimal reaction conditions. According to the documents of Clinical and Laboratory Standards Institute (CLSI), the analytical performance was evaluated, including the limit of blank (LOB), linearity, accuracy, specificity, imprecision and interference test. Finally, 82 SAA plasma samples were collected after the turbidimetric inhibition immunoassay, and the newly established method was used for detection. Moreover, the detection results of the two methods were analyzed by Pearson correlation analysis. Results: The optimal binding ratio of hydrophilic streptavidin and biotinylated antibody was 1∶0.15, the amount of Ho-labeled antibody was 3 µl and the incubation time of the two reaction steps was 40 min and 30 min, respectively. The LOB was 0.6 ng/ml. The linearity was good within the range of 0-1 200 µg/L (R2=0.998 9, P<0.001). The inter-batch precision of high-value samples and low-value samples was 9.42% and 7.95%, respectively, and the intra-batch precision was 14.56% and 13.56%, respectively. The recovery was 96.01%-104.76%. The cross-reaction rates with procalcitonin (PCT) and C-reactive protein (CRP) were 0.45% and 0.015%, respectively. When the concentration of triglyceride≤35.5 mg/L, bilirubin≤0.52 mg/L and hemoglobin≤2.4 g/L, the interference bias was less than 10%. The results of 82 SAA plasma samples were 12.65 (4.45, 59.03) mg/L by ICP-MS immunoassay and 18.23 (9.33, 68.72) mg/L by turbidimetric inhibition immunoassay, respectively. The newly established system was well correlated with turbidimetric inhibition immunoassay (R2=0.983, P<0.001). Conclusion: The quantitative immunoassay for SAA with Ho as marker established in this study has high precision, good accuracy, high specificity, and wide linear range, which can meet the clinical testing requirements.

[Effect of the surgical treatment of maxillary medication-related osteonecrosis of the jaw].

Objective: To explore the methods and clinical effects of the surgery for treating maxillary medication-related osteonecrosis of the jaw (MRONJ). Methods: The clinical data including gender, age, stage of lesion, treatment method and prognosis of 28 patients with maxillary MRONJ who underwent surgical treatment in the Department of Oral and Maxillofacial Surgery of Medical School of Nanjing University from January 2013 to October 2020 were retrospectively analyzed. There were 20 males and 8 females. The mean age at onset was (65.6±11.1) years old. According to the guidelines of American Association of Oral and Maxillofacial Surgeons, the patients' lesions were divided into 2 or 3 stages. Ten cases of stage 2 lesions were tightly sutured after partial jaw resection. Among them, 4 lesions were sutured directly with mucoperiosteal flaps, 4 lesions were covered by adjacent flaps and 2 lesions was covered by buccal fat pad flaps and adjacent flaps. Eighteen cases of stage 3 lesions were treated with sequestrectomy and drainage channels were formed. Patients were followed up regularly after the surgery, and the effect of surgical treatment was judged according to the clinical criteria such as clinical manifestations, local oral examination, imaging examination etc. Results: After follow-up for 12 to 52 months, the postoperative pain score (1.20±2.53) was significantly lower than preoperative pain score (6.70±0.95) (P<0.05) in stage 2 patients. Eight patients' mucosa healed completely without new dead bone formed. Two patients had recurrence and developed to stage 3 at the time of revisit. There were 18 cases of stage 3 lesions, which formed drainage channels after removal of the dead bone. The postoperative follow-up time was 2 to 67 months, and the symptoms of inflammation and infection disappeared. Postoperative pain score (3.40±0.51) was significantly lower than preoperative pain score (7.06±1.00) (P<0.05). Conclusions: Soft tissue flap closure of wound after partial maxillectomy is an effective approach for the treatment of maxillary MRONJ stage 2 lesions, while maxillary stage 3 lesions could be treated for eliminating clinical symptoms and improving the quality of life when establishing unobstructed drainage after dead bone extraction.

[Clinical analysis and surgical treatment evaluation of 23 cases with primary parapharyngeal space tumors].

Objective: To analyze the clinical characters and surgical treatment of primary parapharyngeal space (PPS) tumors. Methods: A total of 23 cases of primary PPS tumors which were treated from November 2011 to December 2017 were included for the retrospective analysis in this study. Results: Twenty-three cases of patients with primary PPS tumors were analyzed in this study. Surgical approach was as follows: transcervial approach applied in 7 cases, transparotid approach in 4 cases, transoral approach in 2 cases, transmandibular approach in 4 cases, and the combined approaches on 6 cases. Besides, among 7 cases with upper PPS tumor, we applied the surgical navigation system in the surgery of 3 cases. The mean surgery duration of these cases, 3.5 h, was shorter than unused ones, while the mean maximum size (MMS) of tumors, 5.7 cm, was also larger. So far, 23 cases had no recurrence and metastasis. The most frequent histopathological type of all the cases was pleomorphic adenoma (8 cases), followed by Schwannoma (5 cases). With an 8-to-72-months follow up, 23 cases had no recurrence, metastasis or death. Conclusions: Surgical resection is preferred in the treatment of PPS tumors. In the upper PPS tumor cases, the surgical navigation system could reduce the operative duration significantly and is more suitable for larger tumors.

Long non-coding RNA LINC00899 as a novel serum biomarker for diagnosis and prognosis prediction of acute myeloid leukemia.

OBJECTIVE: Recently, several long non-coding RNAs (lncRNAs) have been implicated in acute myeloid leukemia (AML). However, the clinical significance of lncRNAs in AML patients still remains unclear. We aimed to evaluate the expression level of lncRNA LINC00899 (LINC00899) and its potential for diagnosis and prognosis in AML. PATIENTS AND METHODS: Expression levels of LINC00899 in bone marrow and serum obtained from AML patients and healthy controls were assessed by quantitative real-time PCR. Receiver operating characteristic (ROC) curves were used to evaluate the sensitivity and specificity of serum LINC00899. The association between serum LINC00899 expression and clinicopathological factors as well as the overall survival were analyzed. RESULTS: We found that the levels of serum LINC00899 were frequently upregulated in the bone marrow and serum of AML patients. Higher expression of serum LINC00899 was positively associated with FAB classification (p = 0.002) and cytogenetics (p = 0.005). Moreover, ROC curve analyses showed that serum LINC00899 could discriminate AML patients from healthy controls with the area under the curve (AUC) of 0.807 (95% CI, 0.7262- 0.8752). In addition, the serum LINC00899 expression level was significantly reduced when the patients achieved complete remission. Kaplan-Meier analysis showed that patients with high serum LINC00899 expression had a shorter overall survival compared with the low serum LINC00899 expression group (p = 0.0013). Finally, Cox proportional hazards analysis showed that high serum LINC00899 expression was an independent prognostic marker of poor outcome. CONCLUSIONS: We firstly found that serum LINC00899 might be a potential and useful noninvasive biomarker for the early clinical detection and prognosis of AML.

Role of PPARα in down-regulating AGE-induced TGF-ß and MMP-9 expressions in chondrocytes.

Peroxisome proliferator-activated receptor is closely associated with the pathogenesis of osteoarthritis. The level of exogenous advanced glycation end-products (AGEs) in articular cartilage is highly associated with the severity of osteoarthritic lesions. However, their interactions and role in promoting osteoarthritisprogression remain unclear. Here, we investigated the effect of AGEs on transforming growth factor (TGF)-ß and matrix metalloproteinase (MMP)-9 expression, and discussed the correlation between AGEs and osteoarthritis, possible signaling pathways and mechanism in rabbit chondrocytes. TGF-ß and MMP-9 mRNA and protein expression, catalase (CAT) and superoxide dismutase (SOD) activity, and malondialdehyde (MDA) and reactive oxygen species (ROS) levels were analyzed in chondrocytes treated with different concentrations of AGEs using RT-PCR and/or western blot; we detected NF-κB nuclear translocation by immunofluorescence. AGE treatment significantly increased TGF-ß and MMP-9 mRNA and protein expression compared to controls (P < 0.01) in a dose-dependent manner (highest at 100 µg/mL). AGE-induced TGF-ß and MMP-9 expressions in chondrocytes were significantly inhibited by anti-RAGE and PDTC (0.1 mM) treatment (P < 0.01). Furthermore, AGE-treatment significantly decreased CAT and SOD activity and increased MDA levels in a concentration-dependent manner compared to controls (P < 0.05), significantly promoting NF-κB nuclear translocation. AGE significantly inhibited the increased expression of TGF-ß and MMP- 9, and induced chondrocyte damage. Its mechanism is associated with RAGE activation, increased ROS expression, and activation of the NF- κB signaling pathways.

Production of cartilage link protein by human granulosa-lutein cells.

Link protein (LP), an extracellular matrix protein in cartilage, stabilizes aggregates of hyaluronic acid (HA) and proteoglycans, including aggrecan and inter-alpha-trypsin inhibitor (ITI). We have shown previously that cartilage LP is present in the maturing rat and mouse ovary. In the present study, we have employed immunohistochemistry to examine the anatomical distribution of cartilage LP in the human ovary. The expression of cartilage LP was selectively detected in the cells within the granulosa compartment of the preovulatory dominant follicle. The HA-positive granulosa-lutein cells were found to be a cartilage LP-positive subpopulation. We subsequently studied the in vitro expression of cartilage LP in cultured human granulosa-lutein cells obtained at oocyte retrieval for in vitro fertilization. Analysis of cultured cells by enzyme-linked immunoaffinity assay, Western blotting and immunofluorescence microscopy revealed that gonadotropin stimulates cartilage LP production. Time-course studies indicated that the cartilage LP production was induced as early as with gonadotropin stimulation for 2 h, and the effect was sustained up to 8 h. Western blot analysis further revealed the presence of the macroaggregates composed of HA, ITI and cartilage LP in the gonadotropin-stimulated granulosa-lutein cell extracts. Collectively, the present results raise the possibility that cartilage LP forms extracellular structures that may have a regulatory function in the developing follicle in the human ovary.

Ryudocan expression by luteinized granulosa cells is associated with the process of follicle atresia.

OBJECTIVE: To evaluate the presence of ryudocan in follicular fluid (FF) and its possible correlation with FF E(2) and P, and to study the levels of ryudocan in granulosa-lutein cells stimulated with hCG. DESIGN: Controlled clinical study and in vitro experiment. SETTING: University teaching hospital. PATIENT(S): One hundred seven patients undergoing IVF. INTERVENTION(S): The FF and granulosa-lutein cells were aspirated from follicles 34 hours after an ovulatory gonadotropin bolus. MAIN OUTCOME MEASURE(S): FF ryudocan, E(2), and P levels as well as hCG-mediated induction of ryudocan. RESULT(S): Ryudocan was abundant in the FF; the concentration of ryudocan in human FF was estimated to be 305.5 +/- 200.8 ng/mL (mean +/- SD). Atretic follicles had higher concentrations of ryudocan (559.1 +/- 156.5 ng/mL). FF ryudocan levels were inversely correlated with FF E(2) (r = -0.5023) and P concentrations (r = -0.4459). A detectable amount of ryudocan was found in pooled granulosa-lutein cells. Ryudocan production was augmented by surge levels of hCG. CONCLUSION(S): Ryudocan is expressed in luteinized granulosa cells in vitro. The higher concentrations of ryudocan in FF of atretic follicles suggest an involvement of ryudocan in the process of atresia.

Suppression of urokinase-type plasminogen activator expression from human ovarian cancer cells by urinary trypsin inhibitor.

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, efficiently inhibits tumor cell invasion and metastasis. We examined the effect of UTI on urokinase-type plasminogen activator (uPA) expression in ovarian cancer cell lines, HOC-I and HRA. By Northern blot, Western blot, ELISA, and zymographic analyses, we demonstrated that UTI inhibited the expression of uPA mRNA and protein in these cells in a time- and dose-dependent manner, independent of whether induction was triggered by phorbol ester. Monoclonal antibody 4G12, which inhibits UTI binding to the cells, produced a dose-dependent abrogation in UTI-mediated down-regulation of uPA expression. These data suggest that UTI significantly down-regulates tumor cell uPA mRNA expression and protein secretion, and that UTI binding to the cells is necessary to exert the UTI's action.

Identification and characterization of a Kunitz-type protease inhibitor in ascites fluid from patients with ovarian carcinoma.

Urinary trypsin inhibitor (UTI; Mr 40 kDa) is a Kunitz-type protease inhibitor that efficiently inhibits cell-associated trypsin and plasmin activities. The aim of this study is to examine the expression pattern of UTI in the human ovarian carcinoma ascites fluid by Western blotting, zymography, immunoprecipitation, immunohistochemistry, biochemical and gene analyses and animal experiments. We have identified and characterized the 40 kDa immunoreactive UTI (UTI(40)) and 8 kDa degradation fragment (UTI(8)) in ascites fluid. The levels of UTI(40) and UTI(8) are elevated in ascites fluid taken from patients with ovarian carcinoma relative to paired plasma samples. The UTI(40) and UTI(8) were identified immunologically by the reactivity with 2 different anti-UTI antibodies recognizing different epitopes of the UTI molecule, functionally by its ability to bind trypsin and structurally by its apparent molecular mass with and without deglycosylation treatment. The purified polypeptides have been sequenced and were identical with sequences obtained from UTI and the carboxyl-terminal domain of UTI, respectively. However, UTI mRNA was not detected in the ovarian carcinoma tissue and ovarian carcinoma cell lines examined. Based on extravasation experiments using intravenously injected biotinylated inter-alpha-trypsin inhibitor (IalphaI; a precursor of UTI), we conclude that UTI(40) and UTI(8) found in the ascites fluid may result from (i) the extravasation of plasma proteins such as IalphaI into the peritoneal cavity via hyperpermeable vessels and (ii) the subsequent degradation of IalphaI and UTI(40) by tumor cell-associated trypsin-like enzymes.

Identity of urinary trypsin inhibitor-binding protein to link protein.

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, directly binds to some types of cells via cell-associated UTI-binding proteins (UTI-BPs). Here we report that the 40-kDa protein (UTI-BP(40)) was purified from the cultured human chondrosarcoma cell line HCS-2/8 by UTI affinity chromatography. Purified UTI-BP(40) was digested with trypsin, and the amino acid sequences of the peptide fragments were determined. The sequences of six tryptic fragments of UTI-BP(40) were identical to subsequences present in human link protein (LP). Authentic bovine LP and UTI-BP(40) displayed identical electrophoretic and chromatographic behavior. The UTI-binding properties of UTI-BP(40) and LP were indistinguishable. Direct binding and competition studies strongly demonstrated that the NH(2)-terminal fragment is the UTI-binding part of the LP molecule, that the COOH-terminal UTI fragment (HI-8) failed to bind the NH(2)-terminal subdomain of the LP molecule, and that LP and UTI-BP(40) exhibited significant hyaluronic acid binding. These results demonstrate that UTI-BP(40) is identical to LP and that the NH(2)-terminal domain of UTI is involved in the interaction with the NH(2)-terminal fragment of LP, which is bound to hyaluronic acid in the extracellular matrix.

Expression of link protein during mouse follicular development.

To gain insight into the role of link protein in ovarian follicle development, we used immunohistochemistry to determine the patterns of link protein expression in mouse ovary in response to gonadotropin stimulation. Polyclonal antibodies were raised against link protein purified from bovine cartilage. Stimulation of immature mice with gonadotropins increased link protein expression in the granulosa layer of large preovulatory follicles. The number and intensity of immunostained cells increased over 2 hr after hCG injection. Cumulus cells stained link protein mainly in the extracellular matrix, whereas mural granulosa cells showed marked deposits of link protein in the cytoplasm. Link protein expression persisted in luteinized granulosa cells after ovulation and in corpora lutea. Link protein staining was also present in the theca cells and oocytes, which was a consistent finding regardless of gonadotropin treatment. The staining intensity was negated by treatment with hyaluronidase, suggesting that the link protein is bound to hyaluronic acid. On Western blotting, a reacting protein species of about 42 kD was seen in the gonadotropin-treated ovarian extract. The precise cellular distribution of link protein in mouse ovary was determined for the first time by an immunohistochemical method in this study. (J Histochem Cytochem 47:1433-1442, 1999)

Identification of link protein during follicle development and cumulus cell cultures in rats.

Cumulus oocyte complex (COC) expansion is induced through hyaluronic acid production and accumulation of proteins of the inter-alpha-trypsin inhibitor family in the gonadotropin-stimulated cumulus cells. Link protein, a glycoprotein found in cartilage, interacts specifically with hyaluronic acid and stabilizes the binding of proteoglycan monomers to hyaluronic acid to form aggregates. The aim of this study was to investigate the expression of immunoreactive link protein during follicle development in rats and in cumulus cells in culture by immunohistochemistry and Western blot as well as by specific enzyme-linked immunosorbent assay. Immunohistochemical analysis revealed that the extracellular matrix of cumulus cells that were morphologically at a stage of COC expansion were markedly stained for link protein, whereas granulosa cells from immature follicles were not stained. Cumulus cells deposited link protein into the extracellular matrix in an in vitro culture system. The staining intensity was negated by the treatment with hyaluronidase, suggesting that the link protein is bound to hyaluronic acid. We have identified a 42-kDa immunoreactive link protein in rat ovary during the preovulatory period and in COC extracts. Addition of FSH to the medium of cumulus cells in culture supplemented with 10% FBS and oocyte-conditioned medium resulted in an increased rate of link protein synthesis. This work suggests that the cumulus cells synthesize the link protein that may stabilize the binding of inter-alpha-trypsin inhibitor or dermatan sulfate proteoglycan to hyaluronic acid to make up hyaluronic acid-rich matrix aggregate.

Urinary trypsin inhibitor down-regulates hyaluronic acid fragment-induced prostanoid release in cultured human amnion cells by inhibiting cyclo-oxygenase-2 expression.

We postulated that urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, may inhibit low molecular weight hyaluronic acid (HA) fragment-induced prostanoid release and de-novo expression of the inducible cyclo-oxygenase-2 (COX-2) isoform in human term amnion cells. Purified amnion cultures were obtained from human fetal membranes and were exposed to a HA fragment (molecular weight 35 kDa) in the presence or absence of UTI (0-5.0 micromol/l). Amnion cells treated with the HA fragment (100 nmol/l) released significantly more prostanoids (PGE2 and PGF2alpha) than controls (PGE2: 2.1 +/- 0.13 pg/10(6) cells/24 h compared with 0.42 +/- 0.01, P < 0.05; PGF2alpha: 1.0 +/- 0.17 pg/10(6) cells/24 h compared with 0.13 +/- 0.01, P < 0.05). UTI inhibited HA fragment-induced prostanoid release in a dose-dependent manner, with 50% inhibitory concentration values of 0.8 micromol/l for PGE2 and 1.9 micromol/l for PGF2alpha. Western blot analyses demonstrated that protein levels of COX-2 were substantially increased in amnion cells treated with HA fragment. HA fragment-mediated COX-2 production was markedly diminished by pretreatment with UTI (1.0 micromol/l). These results are the first to demonstrate that UTI is a potent inhibitor of HA fragment-induced arachidonic acid metabolism.

Immunolocalization of hyaluronic acid and inter-alpha-trypsin inhibitor in mice.

The direct interaction of hyaluronic acid (HA) and heavy chain (HC) of the inter-alpha-trypsin inhibitor (IalphaI) family plays a critical role in the organization and stabilization of the extracellular matrix. The aim of the present investigation was to elucidate the distribution of the IalphaI HC and HA in adult mouse tissues. An immunohistochemical method using a rabbit polyclonal antibody raised against mouse IalphaI heavy-chain peptide and a specific probe for HA (biotinylated HA-binding protein) was used to demonstrate an immunolocalization of IalphaI HC and HA. Distribution and localization of HA was of three types, namely, colocalization with IalphaI HC itself (cartilaginous tissue and ovary), localization around IalphaI HC immunostaining (lung, intestine and skeletal muscle), and localization at a small distance from IalphaI HC or a different distribution pattern (brain, liver, skin and kidney). These results indicate that IalphaI HC could function as an HA-rich matrix stabilizer on the cells of cartilage and maturing ovary, in which IalphaI HC shows colocalization with its predominant ligand, HA.

Serum hyaluronic acid levels during pregnancy and labor.

OBJECTIVE: To study the changes in concentrations of serum hyaluronic acid in uncomplicated human pregnancies. METHODS: We determined the concentrations of serum hyaluronic acid, using a specific enzyme-linked immunosorbent assay, in 70 nonpregnant women, 250 women during their pregnancies, and 68 women at the time of parturition. Results were analyzed for statistical significance with Scheffé test for multiple comparisons. RESULTS: During pregnancy, mean (+/- standard deviation) serum hyaluronic acid levels were 11.4 +/- 4.5, 13.6 +/- 2.8, 20.6 +/- 1.5, and 46.9 +/- 7.9 ng/mL at 5-14 (n = 47), 15-26 (n = 46), 27-37 (n = 58), and 38-40 (n = 99) weeks' gestation, respectively. Pregnant women in labor (n = 68) had significantly higher levels (100.4 +/- 11.3 ng/mL) than did women at term but not in labor (P < .01). CONCLUSION: Maternal serum hyaluronic acid concentrations increase as pregnancy progresses and serum levels increase significantly at term. Hyaluronic acid may be associated with cervical ripening during parturition.

Production of prostanoids via increased cyclo-oxygenase-2 expression in human amnion cells in response to low molecular weight hyaluronic acid fragment.

Increased concentrations of hyaluronic acid (HA) have been found in serum and at uterine cervix at term. In its native form, HA exists as a high molecular weight (MW) polymer, but during parturition a lower MW HA fragment accumulates. The aim of this study was to investigate the regulatory mechanisms responsible for increased amnion prostanoid production and cyclo-oxygenase (COX) expression in response to HA. Human term amnion cells in culture were exposed to native HA polymer (MW 2.2x106) and its fragment (MW 3.5x104). We have determined levels of prostanoids, prostaglandins E2 and F2alpha, in conditioned media using specific immunoassays. Expression of COX-1 and COX-2 was examined with Western blot. Results were analyzed for statistical significance with Mann-Whitney U-test. Human amnion cells treated with HA fragment (100 nmol/l) produced significantly more PGE2 (2.3+/-0.21 (mean+/-S.D.) pg/106 cells/24 h) than controls (0.34+/-0.03) or high MW HA-treated cells (1.2+/-0.21). Protein levels of COX-2, but not COX-1, were substantially increased in amnion cells treated with HA fragment. HA fragment-mediated prostanoid production is markedly diminished by pretreatment with indomethacin. Our results indicate that HA fragment, rather than physiologic native HA polymer, induces amnion cell-derived prostanoid production via increased COX-2 expression. COX-2-mediated prostanoid production is likely a key physiologic event in HA fragment-mediated cervical ripening and the labor onset.

Internalization of urinary trypsin inhibitor in human uterine fibroblasts.

We have characterized the molecular species and internalization of urinary trypsin inhibitor (UTI) in human uterine fibroblasts. Link protein (LP) has previously been identified as one of the cell-associated UTI binding proteins. The truncated forms of UTI were readily detectable in the cells after incubating the cells with purified UTI. Immunoblotting analysis with a panel of domain-specific antibodies revealed that the UTI species lacked the amino-terminal domain of UTI, but contained the carboxyl-terminal domain. We have examined whether LP is involved in the UTI internalization in the cells. Internalization of 125I-labelled UTI was blocked by the intact UTI, but not by the carboxyl-terminal domain of UTI. Treatment with a polyclonal antibody to the UTI binding domain of LP partially inhibited UTI binding to the cells, but did not significantly prevent UTI internalization. In addition, preincubation of the cells with hyaluronidase reduced the UTI binding to the cells, but had no effect on the rate with which UTI was internalized. These data allow us to conclude that there are at least two different mechanisms for internalization of UTI. The major one is via unknown UTI receptors in a Ca2+, Mg2+-sensitive manner and another is via LP.