Snail1 correlates with patient outcomes in E-cadherin-preserved gastroesophageal junction adenocarcinoma

PURPOSE

The poor prognosis of gastroesophageal junction (GEJ) adenocarcinoma is largely associated with metastasis. We here report the first study to investigate the expression of epithelial-mesenchymal transition (EMT) markers Snail1 and E-cadherin in GEJ adenocarcinoma.

METHODS

Snail1 and E-cadherin were detected by immunohistochemistry in a cohort of 128 patients with surgically resected GEJ adenocarcinoma. We assessed the pathologic and prognostic relevance in all patients and within clinically different preserved E-cadherin and reduced E-cadherin-expressing sub-groups.

RESULTS

Immunoreactivity for Snail1 and E-cadherin was positive in 68 and 43 % of tumors, respectively. Snail1-positive tumors had more frequent lymph node metastasis and advanced tumor stage. E-cadherin expression was highly associated with histological differentiation, tumor size, advanced stage, presence of lymph node metastasis and distant metastasis. Patients with positive E-cadherin expression or negative Snail1 expression had significantly favorable overall survival rate. In E-cadherin-preserved tumors, the expression of Snail1 was related to lymph node metastasis, advanced stage and poor patient outcome. However, Snail1 expression had no statistically significant relationship with clinicopathologic parameters or prognosis in the reduced E-cadherin-expressing sub-group. Multivariate survival analysis identified that tumor stage [hazard ratio (HR) 2.440; 95 % confidence interval (CI) 1.216-4.896; P = 0.012], lymph node metastasis (HR 2.404; 95 % CI 1.188-4.867; P = 0.015) and gender (HR 3.244; 95 % CI 1.568-6.714; P = 0.002) were independent prognostic markers for overall survival.

CONCLUSIONS

Snail1 may act more critically in E-cadherin-positive tumors. Evaluation of Snail1 and E-cadherin in GEJ adenocarcinoma may help in assessing malignant properties and stratifying patients.

Short-term therapeutic drug monitoring of mycophenolic acid reduces infection: a prospective, single-center cohort study in Chinese living-related kidney transplantation

BACKGROUND

The role of therapeutic drug monitoring (TDM) of mycophenolic acid (MPA) in kidney transplant recipients (KTRs) is not clear. We performed a prospective cohort study to evaluate the efficiency of MPA TDM in the Chinese population.

METHODS

A total of 183 living-related KTRs were studied; 101 KTRs received controlled-dose mycophenolate mofetil (MMF) (the CD group), and 82 patients received fixed-dose MMF (the FD group). MPA exposure was measured at days 3, 7, 14, and 30 in the CD group, and at day 30 in the FD group. The primary endpoint was treatment failure (a composite of acute rejection, graft loss, death, or MMF discontinuation) at 12 months post transplantation.

RESULTS

In the CD group, with a starting MMF dose of 2 g/day, approximately 35% of patients had high MPA levels, which were >60 mg × h/L, and mean MPA levels were 59.17 mg × h/L and 61.38 mg × h/L for the CD and FD groups, respectively (P = 0.588). After adjusting MMF dose, MPA exposures in the CD group at day 30 were lower than those in the FD group at day 30 (54.06 vs. 61.38, P = 0.004). At month 12, the CD group had fewer infections (16.8% vs. 31.7%, P = 0.018) with no difference in treatment failure, acute rejection, diarrhea, or anemia.

CONCLUSIONS

KTRs can benefit from short-term TDM of MPA in reducing infection, without increasing acute rejection.

Differential expression of hemolymph proteins between susceptible and insecticide-resistant Blattella germanica (Blattodea: Blattellidae)

A proteomic approach combining two-dimensional polyacrylamide gel electrophoresis and tandem mass spectrometry was used to compare hemolymph expression profiles of a beta-cypermethrin-resistant Blattella germanica L. strain and a beta-cypermethrin-susceptible strain. Twenty-eight hemolymph proteins were differentially expressed in the resistant cockroach strain; 19 proteins were upregulated and 9 proteins were downregulated compared with the susceptible strain. Protein identification indicated that expression of putative cuticular protein, nitric oxide synthase, triosephosphate isomerase, alpha-amylase, ABC transporter, and Per a 3 allergen was elevated, and expression of arginine kinase and glycosidase was reduced. The differential expression of these proteins reflects the overall change in cellular structure and metabolism related to the resistance of pyrethroid insecticides.

Matrine-induced apoptosis of human nasopharyngeal carcinoma cells via in vitro vascular endothelial growth factor-A/extracellular signal-regulated kinase1/2 pathway inactivation

Matrine, a main active extract from Sophora flavescens Ait, has been demonstrated to exert anticancer effects on various cancer cell lines, such as malignant melanoma, breast cancer, and lung cancer. However, it is currently unclear whether matrine could also elicit an inhibitory effect on growth of nasopharyngeal carcinoma (NPC), let alone the possible molecular mechanisms. Therefore, in a previous study, we investigated matrine-induced proliferation inhibition and apoptosis in NPC cells. It was shown that proliferation of human NPC cells (CNE1 and CNE2) was significantly diminished by matrine in a dose- and time-dependent manner, and apoptosis was induced in both 2 NPC cells, particularly in CNE2 cells. Moreover, the increased apoptosis rate in matrine-treated CNE2 cells confirmed the proapoptotic activity of matrine. We further found that matrine treatment dose- and time-dependently reduced the levels of vascular endothelial growth factor-A (VEGF-A), and inactivated extracellular signal-regulated kinase1/2 (ERK1/2), followed by increased expression of downstream target caspase-3. Overall, we conclude that matrine could induce apoptosis of human NPC cells via VEGF-A/ERK1/2 pathway, which supports the potential use of matrine in clinically treating NPC.

Interscapulothoracic resection of tumours of shoulder with a note on reconstruction

We retrospectively reviewed the outcomes of 33 consecutive patients who had undergone an extra-articular, total or partial scapulectomy for a malignant tumour of the shoulder girdle between 1 July 2001 and 30 September 2013. Of these, 26 had tumours which originated in the scapula or the adjacent soft tissue and underwent a classic Tikhoff-Linberg procedure, while seven with tumours arising from the proximal humerus were treated with a modified Tikhoff-Linberg operation. We used a Ligament Advanced Reinforcement System for soft-tissue reconstruction in nine patients, but not in the other 24. The mean Musculoskeletal Tumor Society score (MSTS) was 17.6 (95% confidence interval (CI) 15.9 to 19.4); 17.6 (95% CI 15.5 to 19.6) after the classic Tikhoff-Linberg procedure and 18.1 (95% CI 13.8 to 22.3) after the modified Tikhoff-Linberg procedure. Patients who had undergone a LARS soft-tissue reconstruction had a mean score of 18.6 (95% (CI) 13.9 to 22.4) compared with 17.2 (95% CI 15.5 to 19.0) for those who did not. The Tikhoff-Linberg procedure is a useful method for wide resection of a malignant tumour of the shoulder girdle which helps to preserve hand and elbow function. The method of soft-tissue reconstruction has no effect on functional outcome.

Aberrant DNA methylation of MGMT and hMLH1 genes in prediction of gastric cancer

We aimed to explore the association between aberrant DNA methylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) and human mutL homolog 1 (hMLH1) genes with gastric cancer. A total of 283 gastric cancer patients who were confirmed by pathological diagnosis were included in our study. Aberrant DNA methylation of MGMT and hMLH1 were detected. The proportions of DNA hypermethylation in MGMT and hMLH1 in cancer tissues were significantly higher than those in remote normal-appearing tissues. The DNA hypermethylation of MGMT was correlated with the tumor-necrosis-metastasis stage in gastric cancer tissues. Results showed that individuals with gastric cancer in the N1 and M1 stages had a significantly higher risk of DNA hypermethylation of MGMT in cancer tissues [odds ratio (OR) = 1.97, 95% confidence interval (CI) = 1.15-3.37 for the N1 stage; OR (95%CI) = 5.39 (2.08-14.98) for the M1 stage]. In conclusion, we found that aberrant hypermethylation of MGMT could be a predictive biomarker for detecting gastric cancer.

Knockdown of cancerous inhibitor of protein phosphatase 2A may sensitize NSCLC cells to cisplatin

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified human oncoprotein that can stabilize some proteins by inhibiting degradation mediated by protein phosphatase 2A (PP2A) and it increases the proliferation of several cancer cells. Recent studies have highlighted a potential role for CIP2A in promoting tumor progression and metastasis. However, whether CIP2A could increase chemoresistance of cancer cells to chemotherapeutic agent cisplatin remains unclear. To determine whether CIP2A serves as a potential therapeutic target of human non-small-cell lung cancer (NSCLC), we utilized small interference RNA (siRNA) to knock down CIP2A expression in human NSCLC cells and analyzed their phenotypic changes. The data demonstrated that CIP2A silencing led to decreased proliferation, impaired clonogenicity and enhanced chemosensitivity and apoptosis to cisplatin in human NSCLC cells, as well as reduced Akt phosphorylation. In addition, overexpression of CIP2A diminished NSCLC cell chemosensitivity to cisplatin by inducing activation of Akt pathway, suggesting critical roles of CIP2A in NSCLC cell chemoresistance to cisplatin and rasing the possibility of CIP2A inhibition as a promising approach for lung cancer therapy.

A perturbation theory study of electron vortices in electromagnetic fields: the case of infinitely long line charge and magnetic dipole

The novel discovery of electron vortices carrying quantized orbital angular momentum motivated intensive research of their basic properties as well as applications, e.g. structural characterization of magnetic materials. In this paper, the fundamental interactions of electron vortices within infinitely long atomic-column-like electromagnetic fields are studied based on the relativistically corrected Pauli-Schrödinger equation and the perturbation theory. The relative strengths of three fundamental interactions, i.e. the electron-electric potential interaction, the electron-magnetic potential/field interaction and the spin-orbit coupling are discussed. The results suggest that the perturbation energies of the last two interactions are in an order of 10(3)-10(4) smaller than that of the first one for electron vortices. In addition, it is also found that the strengths of these interactions are strongly dependant on the spatial distributions of the electromagnetic field as well as the electron vortices.

Reconstruction of the hemipelvis with a modular prosthesis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint

We report our early experience with the use of a new prosthesis, the Modular Hemipelvic Prosthesis II, for reconstruction of the hemipelvis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint.

We retrospectively reviewed the outcome of 17 patients who had undergone resection of a pelvic tumour and reconstruction with this prosthesis between July 2002 and July 2010.

One patient had a type I+II+III+IV resection (ilium + peri-acetabulum + pubis/ischium + sacrum) and 16 had a type I+II+IV resection (ilium + acetabulum + sacrum). The outcome was assessed at a mean follow-up of 33 months (15 to 59). One patient was alive with disease, 11 were alive without disease and five had died of disease. The overall five-year survival rate was 62.4%. Six patients had a local recurrence. The mean Musculoskeletal Tumour Society score was 58% (33 to 77). Deep infection occurred in two patients, problems with wound healing in five and dislocation in one.

For patients with a primary malignant peri-acetabular sarcoma involving the sacroiliac joint, we believe that this new prosthesis is a viable option for reconstruction of the bony defect left following resection of the tumour. It results in a satisfactory functional outcome with an acceptable rate of complications.

Cite this article: Bone Joint J 2014;96-B:399–405.

A case of adult-onset Still's disease presenting with multifocal central serous chorioretinopathy

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder of unknown etiology with no specific histological features. In this study, we reported a 43-year-old woman who developed AOSD with multifocal central serous chorioretinopathy (CSC). Up to now, the patient is still on close follow-up. Besides, we reviewed the literature emphasized on the ophthalmological features of AOSD.

Peripheral immunomodulation with ginsenoside Rg1 ameliorates neuroinflammation-induced behavioral deficits in rats

Neuroinflammatory disturbances have been closely associated with depression and many other neuropsychiatric diseases. Although targeting neuroinflammatory mediators with centrally acting drugs has shown certain promise, its translation is faced with several challenges especially drug delivery and safety concerns. Here, we report that neuroinflammation-induced behavioral abnormality could be effectively attenuated with immunomodulatory agents that need not to gain brain penetration. In a rat model with intracerebral lipopolysaccharide (LPS) challenge, we validated that ginsenoside Rg1 (Rg1), a well-established anti-inflammatory agent, was unable to produce a direct action in the brain. Interestingly, peripherally restricted Rg1 could effectively attenuate the weight loss, anorexic- and depressive-like behavior as well as neurochemical disturbances associated with central LPS challenge. Biochemical assay of neuroimmune mediators in the periphery revealed that Rg1 could mitigate the deregulation of the hypothalamic-pituitary-adrenal axis and selectively blunt the increase in circulating interleukin-6 levels. Furthermore, these peripheral regulatory effects were accompanied by dampened microglial activation, mitigated expression of pro-inflammatory mediators and neurotoxic species in the central compartment. Taken together, our work suggested that targeting the peripheral immune system may serve as a novel therapeutic approach to neuroinflammation-induced neuropsychiatric disorders. Moreover, our findings provided the rationale for employing peripherally active agents like Rg1 to combat mental disturbances.

High-dose immunosuppressive therapy combined with cord blood infusion and non-myeloablative peripheral blood stem cell transplantation for patients with severe aplastic anemia

OBJECTIVES

The aim of this study was to compare the clinical effective rates of high-dose immunosuppressive therapy combined with cord blood infusion (IS + CBI) and non-myeloablative peripheral blood stem cell transplantation (NSCT) for severe aplastic anemia (SAA).

PATIENTS AND METHODS

Human leukocyte antigen (HLA)-mismatched patients received immunosuppressive therapy combined with IS + CBI, whereas those with HLA matches received NSCT. Clinical effective rates, hematopoietic recovery, and prevalence of complications were compared between the two groups.

RESULTS

No significant difference in total effective rate or 2 years long-term survival was observed between the two groups. The total effective treatment in the NSCT, IS + CBI group was 80%, 68.75%, and the 2 years long-term survival rate in two groups was 2 years 76.66%, 68.75%, respectively. The median times of WBC > 1.0×109/L in the NSCT group was faster than that of IS + CBI group (13 vs 19 days) (p = 0.027). The median recovery times of PLT and Hb in the NSCT group was significantly faster than that of IS + CBI group (19 vs 50 days) (p = 0.00), (27 vs 57 days) (p = 0.001). The SAA group and the very SAA (VSAA) group did not show a significant difference in effective rate (76.74% vs 68.42%) (p = 0.490). In the NSCT group, two preparative regimens did not show a significant difference in effect (70.59% vs 92.31%) (p = 0.141).

CONCLUSIONS

IS + CBI is applicable to HLA-mismatched patients with SAA. NSCT is the treatment of choice for patients with HLA matching alleles. Both treatment methods are effective on VSAA.

The frontal cortex IGF system is down regulated in the term, intrauterine growth restricted fetal baboon

OBJECTIVE

The IGF system exerts systemic and local actions during development. We previously demonstrated that fetal cerebral cortical IGF1 is reduced at 0.5 gestation in our IUGR baboon nonhuman primate model. We hypothesized that by term protein expression of several key IGF system stimulatory peptide pathway components and downstream nutrient signaling effectors of IGF, mammalian target of rapamycin (mTOR) and S6, would decrease, indicating reduced cellular nutrient uptake and protein synthesis.

DESIGN

We fed 7 control baboons ad libitum while 6 baboons ate a globally reduced diet (70% of feed eaten by controls) from 0.16 gestation through pregnancy that produces IUGR. Fetuses were removed at Cesarean section at 0.9 gestation. Frontal cortex sections were stained for IGFI, IGFII, IGFRI, IGFR2, IGFBP2, 3, 5 and 6, and mTOR and ribosomal protein S6 and double stained with NeuN a neuron-specific nuclear antigen.

RESULTS

All proteins stained neuronal cytoplasm except IGFRI which showed only glial cell cytoplasmic and blood vessel staining. IUGR fetuses showed decreased frontal cortical immunoreactive IGFI, IGFII, IGFRI, IGFBP2, 5 and 6, and mTOR and S6 (p < 0.05). IGFBP3 increased (p < 0.05) and IGFR2 was unchanged (p > 0.05). There were no differences between male and female fetal brains.

CONCLUSIONS

When fetal nutrient availability is decreased, IUGR down regulates the IGF system and its mTOR signaling pathway in the fetal frontal cortex coincident with slowed growth. These findings emphasize the importance of the local tissue IGF system in fetal primate brain development.

Clinical and epidemiological survey and analysis of the first case of human infection with avian influenza A(H7N9) virus in Hangzhou, China

To investigate and report on the clinical and epidemiological characteristics of the first case of human infection with avian influenza A(H7N9) virus in Hangzhou, China. A field epidemiological survey was used to study the first case in Hangzhou. The patient was a 39-year-old male chef with a history of exposure to a farm product market and to poultry prior to the onset of disease on 15 March 2013. He had diarrhea, chills, pyrexia, and intermittent cough with freshly red foamy bloody sputum early in his disease. His fever > 39 °C continued for a week with rapid progression. Computed tomography findings showed extensive bilateral consolidation, followed by multiorgan failure. The patient died on the morning of 27 March. His infection was eventually confirmed 1 week later on 3 April. Flu-like symptoms including fever and cough were found in 46 of his 138 close contacts. This was the first case of human infection with avian influenza A(H7N9) virus in Hangzhou. None of the close contacts had onset of the disease. The case patient’s condition progressed rapidly. The source of infection might be his exposure to the farm product market, but the mode of exposure remains unclear.

Cruciferous vegetables consumption and the risk of female lung cancer: a prospective study and a meta-analysis

BACKGROUND

Epidemiological studies evaluating the association between cruciferous vegetables (CVs) intake and female lung cancer risk have produced inconsistent results.

PATIENTS AND METHODS

This study followed 74 914 Chinese women aged 40-70 years who participated in the Shanghai Women's Health Study. CV intake was assessed through a validated food-frequency questionnaire (FFQ) at baseline and reassessed during follow-up. Hazard ratios (HRs) and 95% confidence interval (CIs) were estimated by using Cox proportional hazards models. Furthermore, we carried out a meta-analysis of all observational studies until December 2011.

RESULTS

After excluding the first 2 years of follow-up, 417 women developed lung cancer over a mean of 11.1 years of follow-up. An inverse association of borderline statistical significance was observed between CV consumption and female lung cancer risk, with HR for the highest compared with the lowest quartiles of 0.73 (95% CI 0.54-1.00, P trend = 0.1607). The association was strengthened in analyses restricting to never smokers, with the corresponding HR of 0.59 (95% CI 0.40-0.87, P trend = 0.0510). The finding of an inverse association between CV intake and lung cancer risk in women was supported by our meta-analysis of 10 included studies.

CONCLUSIONS

Our study suggests that CV consumption may reduce the risk of lung cancer in women, particularly among never smokers.

Tailored eculizumab therapy in the management of complement factor H-mediated atypical hemolytic uremic syndrome in an adult kidney transplant recipient: a case report

Atypical hemolytic uremic syndrome (aHUS) is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury (AKI) which frequently progresses to end-stage renal disease (ESRD). In 50% of affected patients, mutations in complement regulatory proteins cause inappropriate complement activation with endothelial injury. Complement factor H (CFH) mutations cause 25% of aHUS cases; these patients have an 80% recurrence risk after kidney transplantation. Eculizumab, an anti-C5 antibody, is effective in limiting hemolysis episodes in patients with aHUS, but less is known about preventing recurrence after kidney transplantation. Herein we report the use of prophylactic eculizumab in an adult with aHUS who underwent kidney transplantation. A 31-year-old female presented with aHUS and progressive AKI associated with low complement 3 level leading to ESRD despite plasmapheresis and corticosteroids. She had a heterozygous nonsense mutation in CFH and reduced plasma CFH levels. She was given preoperative plasmapheresis and eculizumab and underwent living unrelated renal transplantation. Postoperatively, eculizumab was dosed to achieve low functional complement 5 levels and low soluble membrane attack complex levels and she has maintained excellent graft function without aHUS recurrence. We propose that eculizumab with titrated dosing should be used in CFH-mediated aHUS patients who are at a high risk of recurrence.

Aldo-keto reductase 1C3 may be a new radioresistance marker in non-small-cell lung cancer

Human aldo-keto reductase 1C3, type 2 3α-hydroxysteroid dehydrogenase (HSD)/type 5 17β-HSD (AKR1C3) is known to be involved in steroid, prostaglandin and lipid aldehyde metabolism. The role of AKR1C3 in the radiosensitivity to X-rays of human non-small-cell lung cancer (NSCLC) cells was explored. In this study, a specific small interfering RNA (siRNA) to target the AKR1C3 gene was used. A suite of readouts including cell survival were determined using a colony formation assay; apoptosis evaluated by Annexin V expression levels, irradiation-induced cytotoxicity established using a MTT cell viability assay and cell cycle distribution measured by flow cytometry were used in characterizing the role of the AKR1C3 gene. Although AKR1C3 was significantly overexpressed in both our radioresistant subclone cells and NSCLC tissues, a specific AKR1C3 siRNA significantly enhanced cell radiosensitivity and was concomitant with decreased expression of this gene. Furthermore, reduced interleukin-6 (IL-6)-mediated radioresistance was observed when siRNA was used to knock down AKR1C3 activity. This AKR1C3-mediated radioresistance was correlated with an arrest in the G2/M cell cycle and a decreased induction of apoptosis. AKR1C3 may present a potential therapeutic target in addressing radioresistance of NSCLC, and in particular in IL-6-mediated radioresistance.

Meat consumption and risk of lung cancer: evidence from observational studies

BACKGROUND

A number of epidemiological studies have reported inconsistent findings on the association between meat consumption and lung cancer.

DESIGN

We therefore conducted a systematic review and meta-analysis to investigate the relationship between meat consumption and lung cancer risk in epidemiological studies.

RESULTS

Twenty-three case-control and 11 cohort studies were included. All studies adjusted for smoking or conducted in never smokers. The summary relative risks (RRs) of lung cancer for the highest versus lowest intake categories were 1.35 (95% confidence interval (CI) 1.08-1.69) for total meat, 1.34 (95% CI 1.18-1.52) for red meat, and 1.06 (95% CI 0.90-1.25) for processed meat. An inverse association was found between poultry intake and lung cancer (RR = 0.91, 95% CI 0.85-0.97), but not for total white meat (RR = 1.06, 95% CI 0.82-1.37) or fish (RR = 1.01, 95% CI 0.96-1.07).

CONCLUSIONS

The relationship between meat intake and lung cancer risk appears to depend on the types of meat consumed. A high intake of red meat may increase the risk of lung cancer by about 35%, while a high intake of poultry decreases the risk by about 10%. More well-designed cohort studies on meat mutagens or heme iron, meat cooking preferences, and doneness level are needed to fully characterize this meat-lung cancer association.

High cell density and high monoclonal antibody production through medium design and rational control in a bioreactor

A simple feeding strategy was developed and successfully employed for nutritional control in a 2-L fed-batch culture of hybridoma cells. A previously developed stoichiometric model for animal cell growth was used to design a supplemental medium for feeding. Undialyzed fetal bovine serum and trace metals (Fe(2+), SeO(3) (2-), Li(+), Zn(2+), and Cu(2+)) were fed to the cells periodically in addition to the automatic feeding of other nutrients in the supplemental medium. In this study, the maximum viable cell density was increased from 6.3 x 10(6) to 1.7 x 10(7) cells/mL, and the culture span was extended from 340 to 550 hours. The final monoclonal antibody titer achieved was 2400 mg/L. The specific production rates for ammonia and lactate were further reduced from 0.0045 and 0.0048 in our previous fed-batch experiments to 0.0028 and 0.0036 mmol/10(9) cell h, respectively. Only 3.4% of the total glucose consumption was converted into lactate, compared to 67% in a conventional batch culture.

Stoichiometric analysis of animal cell growth and its application in medium design

Animal cell cultivation in vitro has been studied for more than 40 years. However, the culture medium composition has not been designed on the basis of the stoichiometric nutritional demands for animal cell growth. In this article, a model was developed to study the stoichiometric demands for nutrients (including glucose, 20 amino acids, and 10 vitamins)for the synthesis of cell mass and product. The coefficients for these nutrients in the stoichiometric equation governing animal cell growth were determined based on cell composition. In addition, a detailed analysis of the nutrients' roles in the synthesis of cell mass and product was also performed. Applications of the stoichiometric analysis in animal cell cultivation, such as culture medium design, supplemental medium formulation, and feeding strategy will also be discussed. The stoichiometric analysis can be potentially employed to analyze results from animal cell cultures, to improve the performance of culture processes, and to design new process rationally. It can also help to provide a better understanding of animal cell metabolism. Simplifications on the cellular energy metabolism were made in order to simplify the model and to provide the preliminary bases to test the process performance. However, this could introduce inaccuracies for the model and results in errors in the calculations of glucose and glutamine concentrations when employed in medium design. (c) 1994 John Wiley & Sons, Inc.

Energy metabolism and ATP balance in animal cell cultivation using a stoichiometrically based reaction network

A metabolic reaction network is developed for the estimation of the stoichiometric production of adenosine triphosphate (ATP) in animal cell culture. By using the material balance data from fed-batch and batch cultures of hybridoma cells, the stoichiometric ATP productions are determined with estimated effective P/O ratios of 2 for NADH and 1.2 for FADH(2). A significant percentage of the ATP requirement (16-41%) in hybridoma cells is generated directly from free energy release without the participation of oxygen. The oxidative phosphorylation of NADH accounts for about 60% of the total ATP production in the fed-batch cultures and about 47% in the batch culture. The oxidative phosphorylation of FADH(2) accounts for less then 20% of the total ATP production in all cases.A fractional model is devised to analyze the contribution of each nutrient to the ATP production. Results show that a majority of the ATP is produced from glucose metabolism (60-76%). Less than 30% of the ATP is derived from glutamine, and less than 11% is derived from other essential amino acids. The analysis also shows that the glycolytic pathway generates more ATP in the batch (41%) than in the fed-batch (<27%) cultures. The TCA cycle provides 51-68% of the total ATP production. The calculated stoichiometric oxygen consumption differs among the batch and fed-batch cultures, depending on the glucose concentration. This result suggests that the relationship between the oxygen uptake rate (OUR) and cell growth may change with the culture conditions. However, the calculated respiratory quotient (RQ) is relatively constant in all cases.A linear relationship is obtained between the specific ATP production rate and the specific cell growth rate. The maximum ATP yield and the maintenance ATP requirement are determined based on this linear relationship. The biosynthetic ATP demand estimated from the dry cell weight and cell composition is significantly lower than that calculated from the maximum ATP yield, indicating that the non-growth-associated ATP demand may contain other factors than what is considered in the estimation of the biosynthetic ATP demand.

The point mutation induced by the low-energy N+ ion implantation in impatiens balsamine genome

To investigate the effect of genome mutations induced by low energy ions implantation in higher plants, genome mutation of Impatiens balsamine mutant induced by low energy N+ ion implantation were analyzed by the RAPD, ISSR and genome sequence. Six out of the 121 ISSR primers and 6 out of the 135 RAPD primers showed that polymorphism ratios between mutants and wild type were 4.96% and 2.89%, respectively. Sequence analysis revealed that base deletions, insertions, and substitutions were observed in the mutant genome comparable to wild type. N+ induced point mutations were mostly base substitution (77.4%), no duplication, long fragments insertions and deletions was found. In all point mutation, adenine (A) was most sensitive to the N+ ion implantation in impatiens. The transition was mainly A --> guanine (G) (15.90%) and thymine (T) --> cytosine (C) (12.55%). Transversion happened in A <--> T (16.74%), which much higher than C <--> G(5.02%), G <--> T(6.69%), A <--> C (7.11%) bases. These findings indicate that low energy ions being a useful mutagen were mostly cause the point mutation in impatiens.

Role of mammalian homologue of Caenorhabditis elegans unc-13-1 (Munc13-1) in the recruitment of newcomer insulin granules in both first and second phases of glucose-stimulated insulin secretion in mouse islets

AIMS/HYPOTHESIS

We have previously reported that the haplodeficient Munc13-1(+/-) mouse exhibits impaired biphasic glucose-stimulated insulin secretion (GSIS), causing glucose intolerance mimicking type 2 diabetes. Glucagon-like peptide-1 (GLP-1) can bypass these insulin-secretory defects in type 2 diabetes, but the mechanism of exocytotic events mediated by GLP-1 in rescuing insulin secretion is unclear.

METHODS

The total internal reflection fluorescence microscopy (TIRFM) technique was used to examine single insulin granule fusion events in mouse islet beta cells.

RESULTS

There was no difference in the density of docked granules in the resting state between Munc13-1(+/+) and Munc13-1(+/-) mouse islet beta cells. While exocytosis of previously docked granules in Munc13-1(+/-) beta cells is reduced during high-K(+) stimulation as expected, we now find a reduction in additional exocytosis events that account for the major portion of GSIS, namely two types of newcomer granules, one which has a short docking time (short-dock) and another undergoing no docking before exocytosis (no-dock). As mammalian homologue of Caenorhabditis elegans unc-13-1 (Munc13-1) is a phorbol ester substrate, phorbol ester could partially rescue biphasic GSIS in Munc13-1-deficient beta cells by enhancing recruitment of short-dock newcomer granules for exocytosis. The more effective rescue of biphasic GSIS by GLP-1 than by phorbol was due to increased recruitment of both short-dock and no-dock newcomer granules.

CONCLUSIONS/INTERPRETATION

Phorbol ester and GLP-1 potentiation of biphasic GSIS are brought about by recruitment of distinct populations of newcomer granules for exocytosis, which may be mediated by Munc13-1 interaction with syntaxin-SNARE complexes other than that formed by syntaxin-1A.

Schizophrenia shows a unique metabolomics signature in plasma

Schizophrenia is a severe complex mental disorder affecting 0.5-1% of the world population. To date, diagnosis of the disease is mainly based on personal and thus subjective interviews. The underlying molecular mechanism of schizophrenia is poorly understood. Using targeted metabolomics we quantified and compared 103 metabolites in plasma samples from 216 healthy controls and 265 schizophrenic patients, including 52 cases that do not take antipsychotic medication. Compared with healthy controls, levels of five metabolites were found significantly altered in schizophrenic patients (P-values ranged from 2.9 × 10(-8) to 2.5 × 10(-4)) and in neuroleptics-free probands (P-values ranging between 0.006 and 0.03), respectively. These metabolites include four amino acids (arginine, glutamine, histidine and ornithine) and one lipid (PC ae C38:6) and are suggested as candidate biomarkers for schizophrenia. To explore the genetic susceptibility on the associated metabolic pathways, we constructed a molecular network connecting these five aberrant metabolites with 13 schizophrenia risk genes. Our result implicated aberrations in biosynthetic pathways linked to glutamine and arginine metabolism and associated signaling pathways as genetic risk factors, which may contribute to patho-mechanisms and memory deficits associated with schizophrenia. This study illustrated that the metabolic deviations detected in plasma may serve as potential biomarkers to aid diagnosis of schizophrenia.

BCLAF1 is a radiation-induced H2AX-interacting partner involved in γH2AX-mediated regulation of apoptosis and DNA repair

H2AX, a histone H2A variant, has a key role in the cellular response to DNA double-strand breaks (DSBs). H2AX senses DSBs through rapid serine 139 phosphorylation, concurrently leading to the formation of phospho-(γ)H2AX foci with various proteins. However, in the cells with different sensitivity to ionizing radiation (IR)-induced DSBs, still incomplete are those specific proteins selectively recruited by γH2AX to decide different cell fates. Because the abundance of γH2AX indicates the extent of DSBs, we first identified IR-induced dose-dependent H2AX-interacting partners and found that Bcl-2-associated transcription factor 1 (BCLAF1/Btf) showed enhanced association with γH2AX only under high-dose radiation. In acutely irradiated cells, BCLAF1 promoted apoptosis of irreparable cells through disturbing p21-mediated inhibition of Caspase/cyclin E-dependent, mitochondrial-mediated pathways. Meanwhile, BCLAF1 co-localized with γH2AX foci in nuclei and stabilized the Ku70/DNA-PKcs complex therein, facilitating non-homologous end joining (NHEJ)-based DSB repair in surviving cells. In tumor cells, BCLAF1 was intrinsically suppressed, leading to formation of anti-apoptotic Ku70-Bax complexes and disruption of Ku70/DNA-PKcs complexes, all of which contribute to tumor-associated apoptotic resistance and cell survival with defective NHEJ DNA repair. For the first time, our studies reveal that, based on the extent of DNA damage, BCLAF1 is involved in the γH2AX-mediated regulation of apoptosis and DNA repair, and is a γH2AX-interacting tumor suppressor.

Effect of small interfering RNA targeting wild-type FLT3 in acute myeloid leukaemia cells in vitro and in vivo

This study investigated the effect of using small interfering RNA (siRNA) to silence the wild-type FMS-like tyrosine kinase 3 (FLT3) gene in acute myeloid leukaemia (AML) cells, in vitro and in vivo. FLT3 siRNA was introduced into the human AML cell line, THP1, and into a THP1 xenograft tumour model in BALB/c nude mice. FLT3 siRNA effectively reduced both the mRNA and the protein levels of FLT3, arrested cells in G(0)/G(1) phase, inhibited THP1 cell proliferation and increased apoptosis. Intraperitoneal injection of FLT3 siRNA suppressed tumour growth in BALB/c nude mice. FLT3 siRNA treatment also reduced cyclin D1 and Bcl-2 protein levels, and increased the nuclear level of silencing mediator for retinoic acid and thyroid hormone receptors protein both in vitro and in vivo. These data suggest that FLT3 siRNA is a strong inhibitor of FLT3 expression in vitro and in vivo, and may provide a new therapeutic target for AML.

Vaporized Perfluorocarbon Confers Protection against Acute Lung Injury by Inhibiting MMP-9 Expression without Protective Effects in other Organs

OBJECTIVE: Vaporized perfluorocarbon (PFC) is a treatment for lung injury; this study investigated its mode of action and potential protective effects on other organs, which are unclear. METHODS: Acute lung injury was induced by lung lavage with artificial seawater in 32 female New Zealand White rabbits. Animals received either conventional mechanical ventilation (CMV), positive end-expiratory pressure under CMV (PEEP), vaporized PFC ventilation, or positive end-expiratory pressure with vaporized PFC ventilation (PEEP + PFC). Histopathology of the lung, small intestine, liver and kidney were investigated. Matrix metalloproteinase (MMP)-9 mRNA levels in the lung were analysed. RESULTS: Pathological injury of the lung was significantly alleviated in the PEEP, PFC and PEEP + PFC groups compared with the CMV group. Tissue damage in the liver, kidney and small intestine was similar between all groups. MMP-9 mRNA levels in the PEEP, PFC and PEEP + PFC groups were significantly lower than those in the CMV group. CONCLUSIONS: Vaporized PFC ventilation can significantly alleviate lung injury but has no significant protective effect on other organs. Alleviation of lung injury may be associated with MMP-9 inhibition.