Activation of HIF-1α (hypoxia inducible factor-1α) prevents dry eye-induced acinar cell death in the lacrimal gland

The pathogenesis of immune-mediated lacrimal gland (LG) dysfunction in Sjögren's syndrome has been thoroughly studied. However, the majority of dry eye (DE) is not related to Sjögren type, and its pathophysiology remains unclear. The purpose of this study was to determine and investigate the protective mechanisms against DE stress in mice. DE induced prominent blood vessel loss without apoptosis or necrosis in the LG. Autophagic vacuoles, distressed mitochondria, and stressed endoplasmic reticulum were observed via electron microscopy. Immunoblotting confirmed the increase in autophagic markers. Glycolytic activities were enhanced with increasing levels of succinate and malate that, in turn, activated hypoxia-inducible factor (HIF)-1α. Interestingly, the areas of stable HIF-1α expression overlapped with COX-2 and MMP-9 upregulation in LGs of DE-induced mice. We generated HIF-1α conditional knockout (CKO) mice in which HIF-1α expression was lost in the LG. Surprisingly, normal LG polarities and morphologies were completely lost with DE induction, and tremendous acinar cell apoptosis was observed. Similar to Sjögren's syndrome, CD3⁺ and CD11b⁺ cells infiltrated HIF-1α CKO LGs. Our results show that DE induced the expression of HIF-1α that activated autophagy signals to prevent further acinar cell damage and to maintain normal LG function.

Calcium extrusion regulatory molecules: differential expression during pregnancy in the porcine uterus

Calcium ions in the uterine endometrium are essential for the establishment and maintenance of pregnancy, but the cellular and molecular mechanisms of calcium ion regulation in the endometrium are not fully understood. Our previous study in pigs found that calcium regulatory molecules, transient receptor potential, vanilloid type 6 and calbindin-D9K, are expressed in the uterine endometrium during the estrous cycle and pregnancy. However, we did not determine the expression of calcium extrusion regulatory molecules, plasma membrane calcium ATPases (ATP2Bs), sodium/calcium exchangers (SLC8As), or potassium-dependent sodium/calcium exchangers (SLC24As), in the uterine endometrium and conceptuses. Thus, in this study we determine whether ATP2Bs, SCL8As, and SLC24As are expressed in the uterine endometrium during the estrous cycle and pregnancy and in conceptuses during early pregnancy. Real-time RT-PCR analysis showed that ATP2Bs, SLC8As, and SLC24As were expressed in the uterine endometrium in a pregnancy status- and stage-specific manner. Conceptuses during early pregnancy also expressed these molecules. In situ hybridization analysis showed that ATP2B1, SLC8A1, and SLC24A4 were localized mainly to luminal and glandular epithelium and stromal cells in the endometrium during pregnancy. These results indicate that calcium extrusion regulatory molecules are expressed in the uterine endometrium during the estrous cycle and pregnancy and in conceptuses during early pregnancy, indicating that calcium extrusion regulatory molecules may play important roles in the establishment and maintenance of pregnancy by regulating calcium ion concentration in the uterine endometrium in pigs.

An interim analysis of a phase II study of the combination of TACE and sorafenib in patients with unresectable hepatocellular carcinoma in National Cancer Center Korea (COTSUN KOREA, NCT00919009)

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Background: Transarterial chemoembolization (TACE) is the palliative treatment for patients with unresectable HCC. TACE-induced ischemic injury is known to increase circulating VEGF and related with poor prognosis.The aim of this study is to evaluate efficacy and safety of combined TACE with sorafenib, VEGFR inhibitor in unresectable HCC patients.

Methods: This study is a non-randomized, open-labeld, single-arm, phase II investigator-initiated clinical study. Estimated number of subjects was 50 under the assumption of 3.2 months of median time to progression (TTP) with TACE alone. All patients are Child-Pugh class A or superb B. Sorafenib begins to be administered on 3 days after the first session of TACE and will be subsequently administered up to 24 weeks. Efficacy of TACE was evaluated after 4 weeks from TACE by dynamic CT. Repeated TACE is performed “on demand” in case of PR or SD according to CT/MRI evaluation.

Results: A total of 50 patients were enrolled for this interim analysis. Male was 84% and mean age was 61.5years. Causes of underlying chronic liver disease were HBV in 28 patients (65.1%). Patients were categorized into modified UICC stage II (15, 30.0%), III (24, 48.0%) and IVA (11, 22.0%). Median follow-up period was 5.3 months (range, 1.0–13.1). The size of index lesions was ranged from 1.0 cm to 13.1 cm, and number of lesions was between 1 and 5. Number of TACE sessions was 1.0 (range, 1–4). Common adverse events (AE) during sorafenib therapy were elevation of serum AST/ALT (96.8%), hypocalcemia (90.0%), thrombocytopenia (84.0%), and hyperbilirubinemia (76.0%). Hand-foot skin reaction was most frequently observed among AE of NCI CTCAE grade 3 or higher (40.0%), followed by elevation of serum ALT (38.0%). Dose reduction of sorafenib was needed most commonly due to hand-food skin reaction (n=29). Median TTP was 5.1 months (range, 3.8–6.3).

Conclusions: Adverse events were approved as acceptable by independent monitoring system. Preliminary evidence of antitumor activity was also observed. This trial can be safely performed with close monitoring in inoperable and/or unresectable HCC patients.

No significant financial relationships to disclose.

Electrochemical characterization of Pt-Ru-Pd catalysts for methanol oxidation reaction in direct methanol fuel cells

PtRuPd nanoparticles on carbon black were prepared and characterized as electrocatalysts for methanol oxidation reaction in direct methanol fuel cells. Nano-sized Pd (2-4 nm) particles were deposited on Pt/C and PtRu/C (commercial products) by a simple chemical reduction process. The structural and physical information of the PtRuPd/C were confirmed by TEM and XRD, and their electrocatalytic activities were measured by cyclic voltammetry and linear sweep voltammetry. The catalysts containing Pd showed higher electrocatalytic activity for methanol oxidation reaction than the other catalysts. This might be attributed to an increase in the electrochemical surface area of Pt, which is caused by the addition of Pd; this results in increased catalyst utilization.

Electrochemical characterization of nano-sized Pd-based catalysts as cathode materials in direct methanol fuel cells

To improve the catalytic activity of palladium (Pd) as a cathode catalyst in direct methanol fuel cells (DMFCs), we prepared palladium-titanium oxide (Pd-TiO2) catalysts which the Pd and TiO2 nanoparticles were simultaneously impregnated on carbon. We selected Pd and TiO2 as catalytic materials because of their electrochemical stability in acid solution. The crystal structure and the loading amount of Pd and TiO2 on carbon were characterized by X-ray diffraction (XRD) and energy dispersive X-ray microanalysis (EDX). The electrochemical characterization of Pd-TiO2/C catalysts for the oxygen reduction reaction was carried out in half and single cell systems. The catalytic activities of the Pd-TiO2 catalysts were strongly influenced by the TiO2 content. In the single cell test, the Pd-TiO2 catalysts showed very comparable performance to the Pt catalyst.

CHARMM general force field: A force field for drug-like molecules compatible with the CHARMM all-atom additive biological force fields

The widely used CHARMM additive all-atom force field includes parameters for proteins, nucleic acids, lipids, and carbohydrates. In the present article, an extension of the CHARMM force field to drug-like molecules is presented. The resulting CHARMM General Force Field (CGenFF) covers a wide range of chemical groups present in biomolecules and drug-like molecules, including a large number of heterocyclic scaffolds. The parametrization philosophy behind the force field focuses on quality at the expense of transferability, with the implementation concentrating on an extensible force field. Statistics related to the quality of the parametrization with a focus on experimental validation are presented. Additionally, the parametrization procedure, described fully in the present article in the context of the model systems, pyrrolidine, and 3-phenoxymethylpyrrolidine will allow users to readily extend the force field to chemical groups that are not explicitly covered in the force field as well as add functional groups to and link together molecules already available in the force field. CGenFF thus makes it possible to perform "all-CHARMM" simulations on drug-target interactions thereby extending the utility of CHARMM force fields to medicinally relevant systems.

Support vector machine quantile regression for detecting differentially expressed genes in microarray analysis

OBJECTIVES

One of the main objectives of microarray analysis is to identify genes differentially expressed under two distinct experimental conditions. This task is complicated by the noisiness of data and the large number of genes that are examined. Fold change (FC) based gene selection often misleads because error variability for each gene is heterogeneous in different intensity ranges. Several statistical methods have been suggested, but some of them result in high false positive rates because they make very strong parametric assumptions.

METHODS

We present support vector quantile regression (SVMQR) using iterative reweighted least squares (IRWLS) procedure based on the Newton method instead of usual quadratic programming algorithms. This procedure makes it possible to derive the generalized approximate cross validation (GACV) method for choosing the parameters which affect the performance of SVMAR. We propose SVMQR based on a novel method for identifying differentially expressed genes with a small number of replicated microarrays.

RESULTS

We applied SVMQR to both three biological dataset and simulated dataset and showed that it performed more reliably and consistently than FC-based gene selection, Newton's method based on the posterior odds of change, or the nonparametric t-test variant implemented in significance analysis of microarrays (SAM).

CONCLUSIONS

The SVMQR method was an exploratory method for cDNA microarray experiments to identify genes with different expression levels between two types of samples (e.g., tumor versus normal tissue). The SVMQR method performed well in the situation where error variability for each gene was heterogeneous in intensity ranges.

Phase II study of irinotecan based fourth-line chemotherapy for gefitinib therapy-failed non-small cell lung cancer (NSCLC)

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Background: Despite the undoubted gains from EGFR TK inhibitor therapy as 2nd or 3rd line chemotherapy, most of them will relapse during treatment. Among these patients, they might be young, with good performance status, and their disease is expressed with only minor symptoms. The objectives of this study were to evaluate the antitumor efficacy and safety of irinotecan based regimen as 4th line therapy for refractory or recurrent to gefitinib treatment. We report our experience with irinotecan-based 4th line chemotherapy. Methods: Eligibility required proven NSCLC refractory or recurrent after 3rd line chemotherapy(gefitinib), measurable lesions by RECIST, and ECOG PS 0–1. Irinotecan (60mg/m2, day 1,8,15) and/or cisplatin (60 mg/m2, day 1) were administered every four week for at least 2 course. We analyzed for time to tumor progression (TTP) for first, response rates and toxicities. Results: Since June 2004, 17 patients (consisting of 9 with squamous cell, 7 with adeno-, and 1 with NSCLC not further specified) with a median age of 61 years were enrolled, with 1 drop out during treatment. Chemotherapy was administered for a median 2 courses (range 2–6). Median TTP was 91 (range 35–210) days. Two pts achieved a PR and 5 pts a SD. Disease control rate was 41.2%. Response rate was 11.8%. Toxicity of grade 3 or 4 consisted of neutropenia (35.3%), anemia (29.4%), thrombocytopenia (17.7%), nausea (17.6%), and diarrhea (23.5%). There were no treatment related deaths. Conclusions: This irinotecan based chemotherapy for EGFR TK inhinbitor therapy failed NSCLC patients showed promising efficacy with tolerable toxicity. Irinotecan based chemotherapy may be considered a potential therapeutic option for 4th line chemotherapy in well selected patients.

No significant financial relationships to disclose.

Low SER versus high SER thoracic radiotherapy in the management of limited-stage small cell lung cancer

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Background: Patients with small-cell lung cancer account for about 20% of all lung cancer patients, with only one third of the patients presenting with limited disease. Although the combinations of chemo and radiation therapy have improved the prognosis substantially, the optimal chemoradiotherapy remains controversial in LD-SCLC. There are many reports that the overall duration of the chemoradiotherapy package is the most relevant predictor of the outcome. Therefore we tested SER beginning with the start of any treatment until the end of radiotherapy in patients with LD-SCLC. Methods: We enrolled the patients who were diagnosed as SCLC histologically in Korea University Medical Center from 2003 to 2006. All of them presented with limited disease. We divided them into two groups; the low SER (within 60 days of SER) and the high SER group (over 60 days). The patients were treated with thoracic radiotherapy and platinum based topoisomerase inhibitor. Overall survival was analyzed with a Cox model adjusted for performance and the chemotherapy regimen. Results: Of 29 patients, 16 patients were in low SER and 13 patients were in high SER. Low SER, as compared with high SER, significantly prolonged survival rate (p=0.028). We evaluated the radiation effect by the time between the start of chemotherapy and the start of radiotherapy, below 30 days and above 30 days, but there were no statistically comparable difference in there survival time between the two groups (p=0.176). The survival times of the patients were increased by 3.094 times in the low SER (95% C.I, 1.083 to 8.840, p=0.028) and by 6.901 times in ECOG groups 0 or 1 compared with group 2 (95% C.I, 1.563 to 30.468, p=0.018). There were no statistically significant increases in the side effects: pneumonitis, esophagitis, and BM suppressions. Conclusions: The cumulative survival of the patients in the low SER group is higher than for patients in the high SER group. The SER may facilitate a more rational design of combined-modality treatment in rapidly proliferating tumors.

[Table: see text]

No significant financial relationships to disclose.

Halophilic and halotolerant bacteria from river waters and shallow groundwater along the Rouge River of southeastern Michigan

The use of sodium chloride to melt highway and road snow is believed to have a significant effect on the groundwater ecosystem of the rivers where the salt from the roads drain. As the river composition changes, the bacterial population also changes to favour those bacteria that are more suited to the higher salt concentrations. In this experiment, we surveyed the cultivable salt-loving organisms (halophiles) on three sites that encompass the Rouge River (Lotz; site 1, Lilly, site; 8, and Ford Field, site 9). A total of 125 isolates were surveyed. Representative isolates of distinct morphologies were subjected to physiological test, using API strips and identified by 16 rDNA sequence analysis. The 16S rDNA sequences were analyzed and compared with sequences from Genbank. Results indicated that the SSU rRNA sequences of the bacterial isolates were similar to six major genera, Bacillus, Staphylococcus, Halobacillus, Paenabacillus, Halomonas, and Clostridium. Half of the isolates sequenced were similar to Bacillus spp. The API assay showed that the majority of the isolates were positive for the enzymes tryptophane deaminase, gelatinase and beta-galactosidase. Indole production, acetoin production and citrate utilization were not observed for any isolates. Fermentation of carbohydrates was observed for very few isolates. The primary enzyme found in all isolates was arginine dihydrolase, which might be an indicator of the presence of such enzyme in halophilic and halotolerant bacteria present in the Rouge River.

Reverse echelon node and a lymphatic ectasia in the same patient during breast lymphoscintigraphy: the importance of injection and imaging technique

Lymphoscintigraphy, along with triangulated patient body marking, can serve as a guide for surgeons during sentinel lymph node harvesting. Unique drainage patterns have been noted, especially with areolar or intradermal based injections, which are becoming increasingly popular. The images lymphoscintigraphy provide have been invaluable in delineating these patterns. The authors present a case that simultaneously illustrates two separate points in the same patient, a reverse echelon node and a lymphatic ectasia. To our knowledge, this combination has never been described in the same patient. Perilesional and areolar-cutaneous junction injections were performed sequentially and generated these patterns that could potentially have resulted in added morbidity and a false-negative sentinel node if not realised before surgery. Lymphoscintigraphy added valuable information in the management of this patient, which can occasionally present with complex patterns of activity during sentinel node harvesting.

Kinematic changes at intensities proximal to onset of lactate accumulation

AIM

The purpose of this study was to examine changes in selected kinematic variables at 3 running intensities proximal to the onset of blood lactate accumulation (OBLA; 4 mM of blood lactate). It was hypothesized that greater changes in lower body mechanics would occur when running faster than normal race pace compared to when running slower than race pace.

METHODS

Nine competitive male distance runners ran at 3 running intensities (RI): 1) each runner's VO(2) at 10% below the VO(2) at OBLA, 2) VO(2) at OBLA, and 3) VO(2) at 10% above the VO(2) at OBLA. Selected kinematic and physiological variables were measured at each RI.

RESULTS

VO(2) at RI 1, 2 and 3 was highly correlated with running speed (r=0.93). The blood lactate (BL) showed a nonlinear increase from RI 1 (2.9+/-0.8 mM) to 2 (4.1+/-0.9 mM) to 3 (6.7+/-1.8 mM). The vertical oscillation of center of gravity (VOCOG), stride frequency (SF), range of motion (ROM) of trunk angle, and maximal knee flexion during flight phase (MKFF) changed nonlinearly as did the BL. Significant relationships between BL and VOCOG (r=0.44) and between BL and SF (r=0.51) were found (ps<0.05).

CONCLUSION

The findings show a possibility that lower body running mechanics have a relationship with BL.

Zn(2+) induces stimulation of the c-Jun N-terminal kinase signaling pathway through phosphoinositide 3-Kinase

Zn(2+), one of the most abundant trace metal ions in mammalian cells, modulates the functions of many regulatory proteins associated with a variety of cellular activities. In the central nervous system, Zn(2+) is highly localized in the cerebral cortex and hippocampus. It has been proposed to play a role in normal brain function as well as in the pathophysiology of certain neurodegenerative disorders. We here report that Zn(2+) induced stimulation of the c-Jun N-terminal kinase (JNK) pathway in mouse primary cortical cells and in various cell lines. Exposure of cells to Zn(2+) resulted in the stimulation of JNK and its upstream kinases including stress-activated protein kinase kinase and mitogen-activated protein kinase kinase kinase. Zn(2+) also induced stimulation of phosphoinositide 3-kinase (PI3K) The Zn(2+)-induced JNK stimulation was blocked by LY294002, a PI3K inhibitor, or by a dominant-negative mutant of PI3Kgamma. Furthermore, overexpression of Rac1N17, a dominant negative mutant of Rac1, suppressed the Zn(2+)- and PI3Kgamma-induced JNK stimulation. The stimulatory effect of Zn(2+) on both PI3K and JNK was repressed by the free-radical scavenging agent N-acetylcysteine. Taken together, our data suggest that Zn(2+) induces stimulation of the JNK signaling pathway through PI3K-Rac1 signals and that the free-radical generation may be an important step in the Zn(2+) induction of the JNK stimulation.

Glutathione S-transferase mu modulates the stress-activated signals by suppressing apoptosis signal-regulating kinase 1

Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase that can activate the c-Jun N-terminal kinase and the p38 signaling pathways. It plays a critical role in cytokine- and stress-induced apoptosis. To further characterize the mechanism of the regulation of the ASK1 signal, we searched for ASK1-interacting proteins employing the yeast two-hybrid method. The yeast two-hybrid assay indicated that mouse glutathione S-transferase Mu 1-1 (mGSTM1-1), an enzyme involved in the metabolism of drugs and xenobiotics, interacted with ASK1. We subsequently confirmed that mGSTM1-1 physically associated with ASK1 both in vivo and in vitro. The in vitro binding assay indicated that the C-terminal portion of mGSTM1-1 and the N-terminal region of ASK1 were crucial for binding one another. Furthermore, mGSTM1-1 suppressed stress-stimulated ASK1 activity in cultured cells. mGSTM1-1 also blocked ASK1 oligomerization. The ASK1 inhibition by mGSTM1-1 occurred independently of the glutathione-conjugating activity of mGSTM1-1. Moreover, mGSTM1-1 repressed ASK1-dependent apoptotic cell death. Taken together, our findings suggest that mGSTM1-1 functions as an endogenous inhibitor of ASK1. This highlights a novel function for mGSTM1-1 insofar as mGSTM1-1 may modulate stress-mediated signals by repressing ASK1, and this activity occurs independently of its well-known catalytic activity in intracellular glutathione metabolism.

Distinct and redundant functions of mu1 medium chains of the AP-1 clathrin-associated protein complex in the nematode Caenorhabditis elegans

In the nematode Caenorhabditis elegans, there exist two micro1 medium chains of the AP-1 clathrin-associated protein complex. Mutations of unc-101, the gene that encodes one of the micro1 chains, cause pleiotropic effects (). In this report, we identified and analyzed the second mu1 chain gene, apm-1. Unlike the mammalian homologs, the two medium chains are expressed ubiquitously throughout development. RNA interference (RNAi) experiments with apm-1 showed that apm-1 and unc-101 were redundant in embryogenesis and in vulval development. Consistent with this, a hybrid protein containing APM-1, when overexpressed, rescued the phenotype of an unc-101 mutant. However, single disruptions of apm-1 or unc-101 have distinct phenotypes, indicating that the two medium chains may have distinct functions. RNAi of any one of the small or large chains of AP-1 complex (sigma1, beta1, or gamma) showed a phenotype identical to that caused by the simultaneous disruption of unc-101 and apm-1, but not that by single disruption of either gene. This suggests that the two medium chains may share large and small chains in the AP-1 complexes. Thus, apm-1 and unc-101 encode two highly related micro1 chains that share redundant and distinct functions within AP-1 clathrin-associated protein complexes of the same tissue.

Molecular genetic analysis of apm-2 and aps-2, genes encoding the medium and small chains of the AP-2 clathrin-associated protein complex in the nematode Caenorhabditis elegans

In this report, we analyzed the apm-2 and aps-2 genes, which encode the nematode homologues of the medium chain and the small chain of the plasma membrane-associated clathrin-associated protein complex AP-2, respectively. We determined the genomic structure of the two genes. We show that apm-2 and aps-2 genes are expressed in most, if not all, cells during embryogenesis, and that the two genes are expressed primarily in neurons and some hypodermal cells following hatching through adulthood. RNA interference experiments showed that the reduction of either apm-2 or aps-2 gene function causes embryonic lethality, larval lethality at various stages of development, and other morphological defects in the larval stages. These results indicate that apm-2 and aps-2 gene functions are required during both embryogenesis and larval stages, and that their functions may be required in proper neuronal functions.

Rb protein down-regulates the stress-activated signals through inhibiting c-Jun N-terminal kinase/stress-activated protein kinase

The Rb protein is the product of the retinoblastoma susceptibility gene and loss of Rb function is detected in many types of human cancers. Rb plays important roles in the regulation of cell proliferation, differentiation, senescence, and apoptotic cell death. Here we show that Rb can physically interact with c-Jun NH(2)-terminal kinase/stress-activated protein kinase (JNK/SAPK), thereby inhibiting intracellular signals mediated by JNK/SAPK. Both in vitro binding and in vitro kinase studies suggest that a carboxyl-terminal domain of Rb containing amino acids 768-928 might be crucial for inhibiting JNK/SAPK. In comparison, Rb did not affect enzymatic activity of either extracellular signal-regulated kinase 1 or p38. Ectopically expressed Rb also abrogated the apoptotic cell death induced by ultraviolet radiation or the activation of MEKK1, an upstream kinase that can stimulate the JNK/SAPK cascade. JNK/SAPK inhibition highlights a novel function of Rb, which may provide a new mechanism by which Rb regulates cell death. JNK/SAPK is a major protein kinase that can be stimulated in response to a variety of cellular stresses. Our results, therefore, suggest that Rb, by inhibiting JNK/SAPK, may act as a negative regulator in stress-activated intracellular signaling cascades.