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Induction of glucose-regulated protein 78 by chronic hypoxia in human gastric tumor cells through a protein kinase C-epsilon/ERK/AP-1 signaling cascade.

The M(r) 78,000 glucose-regulated protein (GRP78) can be induced by physiological stresses such as glucose deprivation and hypoxia. In solid tumors, hypoxia can promote malignant progression and confer resistance to irradiation and chemotherapy by altering gene expression. Here, we investigated the molecular mechanisms and signaling pathway involved in the late and prolonged induction of the GRP78 gene by hypoxia in a human gastric cancer cell line, MKN28. Nuclear run-on assays and mRNA stability measurements revealed that transcriptional activation, not stabilization of mRNA, contributed to the dramatic induction of GRP78 gene under hypoxia. Induction of GRP78 by chronic hypoxia was completely abolished by pretreatment with PD98059 [a specific inhibitor of mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK1)] or by overexpression of a dominant-negative MEK1 mutant, demonstrating a direct involvement of ERK in the induction of transcription at the GRP78 promoter under these conditions. Furthermore, hypoxia increased the transcriptional activity of a 12-O-tetradecanoylphorbol-13-acetate response element-like motif on the GRP78 promoter and increased the abundance and DNA binding activity of AP-1 complex composed of c-Jun and c-Fos. A selective protein kinase C (PKC) inhibitor, GF109203X, inhibited the induction of GRP78 gene expression as well as the activities of both ERK and Raf-1. Among six PKC isoforms expressed in MKN28 cells, PKC-epsilon expression level and kinase activity were increased by hypoxia. Transfection of MKN28 cells with a dominant-negative PKC-epsilon blocked the induction of GRP78 through ERK by hypoxia, indicating that PKC-epsilon directly participated in GRP78 induction under hypoxia. Taken together, this study shows that a PKC-epsilon-Raf-1-MEK-ERK-AP1 signaling cascade acts on a 12-O-tetradecanoylphorbol-13-acetate response element-like element to mediate hypoxia-induced GRP78 expression in human gastric cancer cells. We also confirmed in vivo the overexpression of GRP78 in surgical specimens of human primary gastric tumors.

Adenocarcinoma↗

Induction of heme oxygenase-1 by phenylarsine oxide. Studies in cultured primary liver cells.

Heme oxygenase-1, the major inducible isoform of heme oxygenase (HO), can be induced by heme and numerous other physical and chemical factors, many of which cause cellular 'stress'. This has led to the realization that HO-1 is a major highly conserved stress or heat shock protein. Recent work has implicated activation of mitogen-activated protein kinases and other kinases in the mechanism of induction of HO-1, and suggested that signal transduction pathways through tyrosine kinases are involved in induction of HO-1 gene expression by stress inducers. We hypothesized that phenylarsine oxide (PAO), an inhibitor of protein tyrosine phosphatases (PTPs), might up-regulate the HO-1 gene. Here, we show that a remarkably brief (1-15 min) exposure of normal hepatocytes to low concentrations (0.5-3 microM) of PAO produces a marked increase in mRNA and protein of HO-1. This increase is comparable to the level obtained by addition of heme (20 microM), and occurs without producing changes in cellular glutathione levels or stabilization of HO-1 message. Preincubation of cells with inhibitors of protein synthesis decreased the ability of PAO to increase levels of HO-1 mRNA, suggesting that the inductive effect requires de novo protein synthesis. Addition of thiol donors abrogated the PAO-mediated induction of HO-1 in a dose dependent fashion. Addition of genistein, a tyrosine kinase inhibitor, blunted the induction produced by both PAO and heme. After brief incubations with PAO or heme, cell extracts showed comparable increases in levels of protein tyrosine phosphorylation in general, and specifically in ZAP70 kinase. Our results are consistent with the proposition that induction of HO-1 by PAO involves inhibition of specific PTP(s), and that the mechanisms of induction of HO-1 by PAO and by heme may share some common pathways.

Actins↗

[Comparison of vaginal misoprostol and oxytocin for labor induction in post-term pregnancy].

OBJECTIVES: To compare labour induction intervals between vaginal misoprostol and intravenous oxytocin as well as side effects of induction in post term pregnancies with intact membranes. METHODS: One hundred women were retrospectively selected to two groups treated with vaginal misoprostol 50 micrograms every 12 hours as needed to maximum 150 micrograms and treated with intravenous oxytocin. The primary outcome measure was time from induction to vaginal delivery. Statistical analysis was performed by t-Student test. RESULTS: Maternal age, parity, gestation were similar. There was a statistically important difference in labour induction intervals between the two groups. The mean time +/- SD to vaginal delivery in misoprostol group was 20.6 +/- 15.2 hours compared with 11.23 +/- 7.4 hours with oxytocin (p = 0.0396). Induction of labour failed in 12% and 32% in misoprostol and oxytocin treated group. Pethidine consumption in oxytocin treated group was higher (41 mg vs 89 mg, p = 0.04). Episodes of vomiting were more frequent in misoprostol treated group (22% vs 6%). There were no episodes of uterine hyperstimulation in both groups. CONCLUSIONS: Oxytocin stimulation resulted in a shorter induction to delivery interval. In misoprostol group induction failed in only 12% whereas in oxytocin group in 32%. There were no serious side effects in both groups. In misoprostol treated group patients required less analgetics then in oxytocin treated group.

Adult↗

[Misoprostol and oxytocin for induction of cervical ripening and labor in patients with term pregnancy and premature membrane rupture].

OBJECTIVE: To evaluate the effect of the concurrent administration of intravaginal misoprostol and oxytocin for cervical ripening and labor induction on length labor, mode of delivery and perinatal outcomes. PATIENTS AND METHODS: One hundred seven patients with singleton pregnancy at term, vertex presentations, premature rupture of membranes and Bishop scores of < or = 4 were randomly assigned to receive one of three treatments: Group I: Intravenous oxytocin plus intravaginal misoprostol (n = 36); Group II: Intravenous oxytocin plus placebo intravaginal (n = 34); Group III: Intravaginal misoprostol plus intravenous placebo. The time interval from induction to beginning of the labor, from induction to delivery, mode of delivery and perinatal outcomes were measured. RESULTS: The mean time from induction to beginning of labor was different between the groups: Group I: 48.75 minutes, Group II: 107.50 minutes, Group III: 95.94 minutes (p = 0.0024). The mean time in minutes from induction to delivery was different between the groups: Group I: 359.83; Group II: 537.05; Group III: 474.54 (p < 0.05). The frequency of tachysystole, mode of delivery and perinatal outcomes were similar among the three groups. CONCLUSIONS: Oxytocin that is administered simultaneously with intravaginal misoprostol for cervical ripening and labor induction in patients with pregnancies at term, premature rupture of membranes and Bishop scores < 4 make the labor beginning quickly, significantly shortens induction to delivery times without affecting the mode of delivery and with no apparent adverse maternal and perinatal effects.

Adult↗

[Combined usage of taxotere in induction chemotherapy of head and neck neoplasms].

BACKGROUND & OBJECTIVE: There were few reports about combined usage of taxotere in induction chemotherapy of head and neck cancer. It was reported previously that the total response rate in advanced head and neck cancer using TPF regimen [taxotere+cisplatin(DDP)+5-fluorouracil (5-FU)] was 93%. In this article, the authors preliminarily reported the response rate and side effects of TPF regimen in head and neck cancers. METHODS: Twenty-five cases with head and neck cancers in Guangzhou Tumor Hospital from January 1999 to June 2002 were reviewed. All cases underwent induction chemotherapy using TPF regimen (taxotere 75 mg/m(2), i.v. drip, d1; DDP 20 mg/m(2), i.v. drip, d1-3; 5-FU 300 mg/m(2), i.v. drip, d1-3; repeat per 3 weeks). All cases were followed up during chemotherapy and their response was evaluated after induction chemotherapy. The side effects were recorded. RESULTS: Six cases (24.0%) and 12 cases(48.0%) presented complete remission (CR) and partial remission (PR) after induction chemotherapy using TPF regimen, respectively. There were 7 cases with minimal or none response. The total response rate (CR+PR) after TPF induction chemotherapy was 72.0%. The response rates in oral cancers and the cancers in other primary sites including the base of tongue, larynx, hypopharynx, and nasopharynx were compared. It demonstrated that the response rates were 63.6%(7/11) and 71.4%(10/14), respectively, and there was no significant difference between the two groups (P=0.504). In this study, there were 9 cases that relapsed after first treatment. Their response rate after TPF induction chemotherapy was 44.4% (4/9), which had 1 case of CR and 3 cases of PR. In this study, 36.0% (9/25) patients had leucopoenia including 16.0% (4/25) of degree I, 16.0% (4/25) of degree II, 4.0%(1/25) of degree III according to WHO standard;64%(16/25) of patients presented side effects in alimentary system, but the level was all under II according to WHO standard. The side effects in kidney in all patients were degree 0. Other side effects included hair loss but their degrees were all under II according to WHO standard. CONCLUSION: Induction chemotherapy using TPF regimen in local advanced head and neck cancers could have good chemotherapy response. It is effective for local relapse cases after first treatment and its side effects are tolerable.

Adult↗

Tolerance induction in resting memory B cells specific for a protein antigen.

Resting memory B lymphocytes specific for the model protein Ag cytochrome c have been shown to be susceptible to tolerance induction in in vitro splenic fragment cultures. This induction of nonresponsiveness is dependent upon the strength of the interaction between surface Ig and specific Ag, where concentration, valency, affinity, and time of exposure all appear to be important factors, as is the case for tolerance induction in immature or primary B cells. The induction of nonresponsivenes in greater than 80% of Ag-specific memory B cells was achieved by incubation with 1 microM cytochrome polymer for 24 h in the absence of T cell help. Not only were memory B cells unresponsive to specific Ag, they were also unable to become activated through nonspecific uptake and presentation of an Ag to which T cells have been primed, demonstrating that the induction of nonresponsiveness involves more than a modulation or blockade of surface Ig receptors. Although soluble factors collected from activated T cells failed to prevent memory B cells from becoming nonresponsive after surface Ig cross-linking, the direct activation of T cells within splenic fragment cultures did partially inhibit tolerance induction in splenic fragment memory B cells. In addition, the induction of tolerance was partially blocked by protein tyrosine kinase inhibitors, suggesting a physiologic change within the B cells associated with the state of nonresponsiveness and resulting from tyrosine-specific phosphorylation.

Animals↗

[Current practice and results of labor induction].

INTRODUCTION: The role of labor induction has been gradually increasing in the last decade all over Europe due to the early detection of fetal jeopardy, improvement of neonatal therapy and availability of cervical ripening agents. Success rate of vaginal delivery depends on maternal, fetal condition and cervical status. PATIENTS: Authors report the outcome of 795 labor inductions during the period from 1996 to 2000 at the Department of Obstetrics and Gynecology at the University of Debrecen, Hungary. Preinduction cervical ripening and induction method was based on Bishop score and clinical situation. RESULTS: The rate of induced labor was 5.97% out of 13312 consecutive deliveries. The outcome of induction is discussed in details. The caesarean section rate after induction of vaginal delivery was 25% in this high risk group, and 33.3% among the total number of inductions. CONCLUSIONS: The clinical application of prostaglandins for cervical ripening among high risk pregnant women facilitates the decision of labor induction and provides a favourable rate of vaginal deliveries.

Adult↗

Induction therapy for early-stage non-small-cell lung cancer.

Data from adjuvant trials clearly indicate that one of the most important problems in patients with resected non-small-cell lung cancer (NSCLC) is compliance to chemotherapy. In the postoperative setting, significant comorbidities and incomplete recovery after surgery often make it difficult for patients to tolerate or comply with systemic therapy. Therefore, it may be preferable to deliver chemotherapy before surgery as "neoadjuvant" or "induction" chemotherapy. The rationale for using induction chemotherapy is based on evidence that chemotherapy might reduce tumor burden and possess activity against micrometastases, resulting in improved results by surgery, radiotherapy, or a combination. Moreover, induction therapy facilitates in vivo assessment of tumor response or resistance. Potential drawbacks include the risk of perioperative complications, and the possibility that the tumor mass may become unresectable due to disease progression. During the past decade, four phase III randomized trials evaluated the role of induction chemotherapy in stage IIIA NSCLC. The first three studies consistently showed that induction chemotherapy improves survival compared with surgery alone. More recently, a large phase III trial performed by French investigators suggested a survival benefit in stage I/II patients, but not stage IIIA. The high activity of new platinum-based chemotherapy--based on response rate and 1-year survival in advanced disease--reinforces the rationale for the use of these new combinations in early-stage NSCLC, especially for a subset of patients traditionally treated with surgery alone. Several phase III trials are currently evaluating the role of new doublets as induction chemotherapy; these are discussed in the article. The results of these ongoing phase III trials should help clarify the role of induction chemotherapy in early-stage disease.

Antineoplastic Combined Chemotherapy Protocols↗

A comparison of propofol and ketamine as induction agents for cesarean section.

OBJECTIVE: To compare the neonatal and maternal effects of propofol and ketamine as induction agents for elective cesarean section. DESIGN: Randomized, double-blind study. SETTING: Inpatient Obstetrics Department of Sappasitthiprasong Ubonratchatani Hospital, Ubonratchatani province, Thailand INTERVENTION: 2 groups of 50 patients each receiving either 2 mg/kg propofol or 1 mg/kg ketamine for the induction of anesthesia. RESULTS: The time from the induction to cord clamping (I-C), the time from the uterine incision to cord clamping (U-C), the hemodynamic changes, sleep'quality, dream, recall, awareness, Postoperative nausea & vomiting (PONV), and Apgar scores were studied In the ketamine group Systolic Blood Pressure and Diastolic Blood Pressure rose about 10-25% of the baseline after the induction, intubation, skin incision, and cord clamping (p < 0.001) while in the propofol group only the Heart Rate rose (p < 0.036) after the induction, the intubation, the skin incision, and cord clamping. Apgar scores, the I-C time, the U-C time, the age, the weight and total amount of methergin and oxytocin were not significantly different in both groups. No incidence of awareness, nightmare and ketamine's phychomimetic side effects was found The incidence of unpleasant light sleep, dreams and PONV was low. Most patients were willing to have the same anesthetic technique for the next cesarean section (81.3% of the propofol group & 86% of the ketamine group). CONCLUSION: Both propofol and ketamine can be used as alternative induction agents to thiopental. The addition of sevoflurane immediately after the induction, together with the use of midazolam and morphine after delivery shall prevent awareness and ketamine's phychomimetic side effects. However ketamine was cheaper and although Systolic Blood Pressure and Diastolic Blood Pressure were elevated they were within an acceptable range.

Adult↗

[Mouth opening in relation to the craniocervical position during induction of general anesthesia].

BACKGROUND: Decreased mouth opening and limited neck mobility sometimes make direct laryngoscopy or tracheal intubation difficult and compromise the safety in establishing the airway during induction of general anesthesia. Recent report indicated that mouth opening was related to the craniocervical position in awake subjects. The query about whether the neck position modulate the mouth opening during anesthetic induction under paralyzed condition is not clarified. We hypothesized that the neck extension and the flexion induce changes in inter-incisor distance (IID) during anesthetic induction. METHODS: Thirty relatively young patients for general anesthesia were (male; 20, female; 10) subjected. IID was measured with his/her neck positioned flexed, neutral and extended in the sagittal plane, each at preanesthetic awake period, and during anesthetic induction period. The effect of sniffing position on the mouth opening was also studied. RESULTS: At preanesthetic period, IID (mean +/- SD in mm) at neck flexion (37.4 +/- 7.8) was significantly shorter than both at neutral (44.1 +/- 7.5) and at extension (47.4 +/- 7.0). During induction, significant increase in IID was observed as patients' neck position changed from flexed (31.8 +/- 5.4) to neutral (36.6 +/- 5.4), and extended, (41.7 +/- 8.3). Sniffing position did not affect the mouth opening both at preanesthetic and during anesthetic induction period. CONCLUSIONS: Craniocervical extension may play a desirable role in the airway management with mouth opening widely during anesthetic induction under neuromuscular blockade.

Adult↗

Elective induction vs. spontaneous labor associations and outcomes.

OBJECTIVE: To determine factors and outcomes associated with elective medical induction of labor as compared with spontaneous labor in low-risk women. STUDY DESIGN: Using a birth certificate database including 11,849 low-risk, laboring women, univariate and multiple logistic regression was used to evaluate demographic and obstetric factors associated with elective labor induction. Low risk was defined as singleton, vertex, 37-41 weeks' gestation, no prior cesarean section, and no presenting medical/obstetric diagnoses considered indications for cesarean or induction. Adverse neonatal outcome was defined as 1- or 5-minute Apgar score < 7, neonatal intensive care unit admission or respiratory distress. Spontaneously laboring women (n = 10,608) were compared with women who underwent induced labor for no apparent medical/obstetric reason (n = 1,241). Interventions and outcomes during and after labor induction were adjusted for relevant associated variables. RESULTS: Odds ratios for epidural anesthesia, cesarean delivery and diagnoses of nonreassuring fetal heart rate patterns were independently increased following elective induction; odds ratios for cephalopelvic disproportion, instrumental delivery and adverse neonatal outcome were not. Maternal length of stay was 0.34 days longer with induction than with spontaneous labor (p < 0.0001). Slightly more induced labors ended before midnight. CONCLUSION: As compared with spontaneous labor, elective labor induction is independently associated with more intrapartum interventions, more cesarean deliveries and longer maternal length of stay. Neonatal outcome is unaffected.

Adult↗

[Effect of etomidate on hemodynamics in elderly and shock patients during general anesthesia induction].

OBJECTIVE: To investigate the effect of etomidate on the hemodynamics in elderly and shock patients during general anesthesia induction. METHODS: Totally 100 elderly patients or patients with hemorrhagic shock (ASA II -III ) undergoing surgery were studied. Anesthesia was induced with 4 microg/kg of fentanyl, 0.1 mg/kg of vecuronium and 0.2-0.3 mg/kg of etomidate, and the mean arterial blood pressure (MAP), heart rate (HR), stroke volume (SV), stroke index (SI), cardiac output (CO), cardiac index (CI), cardiac acceleration index (ACI), left cardiac work (LCW), and left cardiac work index (LCWI) were recorded using thoracic electrical bioimpedance (TEB) hemodynamic monitoring system before induction and at 1, 2 and 3 min after etomidate injection as well as at 3 min after intubation. RESULTS: After etomidate injection, MAP, HR, SV, SI, CO, CI, ACI, LCW and LCWI were decreased significantly as compared with those before induction (P<0.05). MAP, HR, CO, CI and ACI at 3 min after intubation were higher than those before induction (P<0.05), and the other indices resumed the baseline level. The amplitudes of such changes in the recorded indices was below 20% of the baseline level in the course of anesthesia induction. CONCLUSION: Cardiovascular hemodynamics may vary slightly during the course of induction with etomidate, which is an ideal drug for anesthesia induction for elderly or shock patients with unstable hemodynamics.

Abdomen↗

Profiling of signaling molecules in four different human prostate carcinoma cell lines before and after induction of apoptosis.

We have treated four prostate tumor cell lines, DU-145, PC-3, LNCaP and 22RV1 with various concentrations of cisplatin in order to check for influence on viability and for onset of apoptosis induction. At a cisplatin concentration of 20 microM, 22RV1 and DU-145 cells showed approximately 22% and 18% and PC-3 and LNCaP cells showed approximately 4 and 10% dead cells, respectively. When checking for apoptosis induction, the differences among the cell lines became even more evident. DU-145 and 22RV1 cells showed apoptosis induction at 5- and 2-microM cisplatin, whereas in the case of LNCaP and PC-3 cells comparable apoptosis induction was observed at 100-microM cisplatin; hence, the difference between the two groups of cell lines with respect to apoptosis induction is 20- and 50-fold, respectively. We used 37 antibodies to screen the expression levels of key signaling molecules and their phosphorylation status where appropriate. DU-145 and PC-3 cells are androgen-receptor negative and harbor non-functional p53, whereas LNCaP and 22RV1 cells are androgen-receptor positive and harbor wild-type p53. The results of the profiling of DU-145 and PC-3 support the notion that an intact PTEN/AKT pathway (as found in DU-145 and 22RV1 cells) and the presence of active p38 are responsible for the high sensitivity to apoptosis induction and that neither the androgen receptor nor the p53 status is of primary importance for the differences observed with respect to apoptosis induction.

Antineoplastic Agents↗

The addition of induction chemotherapy with etoposide, ifosfamide, and cisplatin failed to improve therapeutic outcome of concurrent chemoradiotherapy in patients with locally advanced non-small cell lung cancer -- single institution retrospective analysis.

Although chemoradiotherapy (CRT) is a standard treatment for unresectable locally advanced non-small cell lung cancer (NSCLC), the optimal sequencing remains to be determined. We retrospectively compared the treatment results of induction chemotherapy followed by concurrent CRT (induction group, 32 patients) with those of concurrent CRT alone (concurrent group, 41 patients) in unresectable stage IIIA/IIIB NSCLC patients. In induction group, 2 cycles of induction chemotherapy (etoposide/ifosfamide/cisplatin: 24 patients, others: 8 patients) were followed by concurrent CRT (60 Gy/30 fractions, 6 mg/m2 of cisplatin daily), while the same concurrent CRT was administered in concurrent group. Clinicopathologic characteristics including age, weight loss, histologic types, and clinical stage did not show significant differences between two groups except for a higher proportion of patients with ECOG performance status 2 in concurrent group (3% vs. 27%, p=0.015). Overall toxicity was generally acceptable with 1 treatment-related death from tracheoesophageal fistula in induction group. The response rates after concurrent CRT were 41% for induction group and 54% for concurrent group, which showed no significant difference (p=0.560). With median follow-up of 13 (1-92) months, there was a trend toward an advantage for concurrent group in median progression-free survival (6 months vs 8.3 months, p=0.067) and overall survival (12 months vs. 14.5 months, p=0.059). In multivariate analysis, only more than 10% weight loss within 6 months was significantly associated with poor survival (p=0.001). In conclusion, the addition of induction chemotherapy to concurrent CRT did not show any advantage over concurrent CRT alone in locally advanced NSCLC.

Antineoplastic Combined Chemotherapy Protocols↗

Glucocorticoid-receptor interaction and induction of murine mammary tumor virus.

The relationship between the cellular uptake of glucocorticoid hormones, the binding of these hormones to specific in vitro receptors, and the induction of mouse mammary tumor viruses in an established mouse mammary tumor cell line was highly correlated. These results suggest that the induction of mouse mammary tumor virus by glucocorticoid hormones is a physiological process acting through a mechanism of high affinity, saturable steroid-receptors. A temperature-sensitive or salt-dependent step following glucocorticoid-receptor interaction was required for nuclear uptake of the steroid. Induction studies with different adrenocorticoids indicate that the synthetic glucocorticoid, dexamethasone (1,4-pregnadiene-9-fluor-16alpha-methyl-11beta,17alpha,21-triol-3,20-dione), is the most potent inducer of mouse mammary tumor viruses and all steroids which caused significant induction were glucocorticoids. Other glucocorticoids appear to stimulate murine mammary tumor virus production by a mechanism similar to that of dexamethasone; for example, corticosterone competes with dexamethasone for binding to the glucocorticoid receptor and blocks the uptake of dexamethasone into cells. Progesterone also blocks the cellular uptake of dexamethasone and can bind to the glucocorticoid receptor at low concentrations (10-7 to 10-8 M) but progesterone does not consistently induce virus at hormone concentrations even as high as 10-4 M. Thus, in this system, binding to a cytoplasmic receptor is necessary but not sufficient for induction by glucocorticoids. Estrogens and androgens interfere with receptor binding and cellular uptake of dexamethasone but only at much higher concentration (10-4 M) than progesterone, and do not induce mammary tumor virus production. Although there was a positive correlation between steroid structure, binding, and biologic induction, other factors clearly affect the physiological manifestations of steroid actions. Mouse cells with comparable cytoplasmic receptor levels and comparable nuclear uptake differed absolutely in their degree of murine mammary tumor virus induction following hormone treatment. Although all mouse cells examined contain comparable levels of murine mammary tumor virus DNA, only cells producing constitutive levels of murine mammary tumor virus RNA could be induced to higher levels by a variety of glucocorticoids.

Aldosterone↗

[Growth and osteogenesis characteristics of cultured canine mesenchymal stem cells under osteogenic induction].

To investigate the growth and osteogenesis characteristics of cultured canine mesenchymal stem cells (cMSCs) under osteogenic induction. We found the cMSCs were isolated from adult canine using density gradient separation method. The cMSCs attachment formed soon after seeding and grew into colonies with the appearance of fibroblastic cells. The osteogenic induction compound of Dexamethasone (Dex), beta-sodium glycerphosphate (beta-GP), ascorbic acid (AA) was added to passaged cMSCs and the proliferation and osteogenic differentiation of them was studied. The morphology of cells was observed by light micrograph and transmission electron microscope. The proliferation and growth characteristics of cMSCs were observed during primary and passage cultures through MTT. The differentiation were assayed by alkaline phophatase (ALP) and osteocalcin (OCN). We found the cMSCs have an active proliferative ability in primary and passage culture, and cMSCs under osteogenic induction have the typical characteristic of a secretory cell; the osteogenic induction compound may induce cMSCs to differentiate to osteoblasts. There are higher expression of ALP and OCN in passage 3 cMSCs under osteogenic induction than that of the osteoblasts osteogenic induction condition. Our research suggest the cMSCs in our culture system are mainly undifferentiated osteoprogenitors and can differentiate to osteoblast under osteogenic induction.

Animals↗

[The effect of induction temperature on aggregation of consensus interferon-alpha expressed by Pichia pastoris].

The effect of induction temperature on aggregation of consensus interferon-alpha expressed by Pichia pastoris was investigated. The cell growth and cIFN level were analyzed and compared when Pichia pastoris was grown at 30,25,20 degrees C during induction phase, using 5.0L fermentor. The result suggested that the cell growth was not affected much under the different induction temperature, but the protein level declined markedly with the decrease of the induction temperature. The total protein ammount induced at 20 degrees C was 67.8 percent of that at 30 degrees C. SDS-PAGE and native-PAGE as well as Western blotting analysis were further conducted. The electrophoresis results revealed that cIFN formed aggregates after secreted into media when protein was induced at 30 degrees C but this problem can be restored by decreasing the induction temperature to 20 degrees C. cIFN monomer in supernatant arrived at 570mg/L and bioactivity of fermentation broth reached 1.05 x 10(9) IU/mL at 20 degrees C of induction temperature. The amount of cIFN monomer and bioactivity in supernatant elevated 7.2 and 38.7 times, respectively, when the induction temperature was controlled at 20 degrees C instead of conventional 30 degrees C.

Fermentation↗

Role of protein kinase C in IFN-mediated Ly-6E antigen induction.

The YAC T cell lymphoma normally does not express Ly-6E mRNA or Ly-6E surface molecules but can be induced to do so on incubation with either IFN-gamma or IFN-alpha/beta. This system afforded a model to assess the possible role of protein kinase C (PKC) in IFN-mediated Ly-6E induction. First, we used various pharmacologic agents known to interfere with the function of PKC or other kinases. The PKC inhibitors H-7 and phloretin were found to block Ly-6E induction by IFN-gamma or IFN-alpha/beta both at the mRNA and protein levels. In contrast, inhibitors of cyclic nucleotide-dependent kinases (HA1004), of myosin L chain kinase (ML-9, A-3) or of calmodulin (R24157, W-7) failed to suppress this induction. Next, we investigated the effects of the PKC activators PMA and mezerein (MEZ) on Ly-6E expression. Although neither PMA nor MEZ by themselves could induce Ly-6E in YAC cells, both agents enhanced by up to fivefold the induction of Ly-6 mRNA and Ly-6E surface expression triggered by IFN-gamma. However, the induction of Ly-6E expression caused by IFN-alpha/beta was only marginally increased by cotreatment of YAC cells with PMA or MEZ. Altogether, these observations demonstrate that PKC or a related kinase is involved in the transduction mechanisms that lead to Ly-6E induction. However, activation of PKC is not sufficient for this induction and requires other unidentified signal(s) provided by IFN. Our data also indicate that IFN-gamma and IFN-alpha/beta induce Ly-6E through overlapping but distinct intracellular pathways with different sensitivities to PKC activators.

Animals↗