Induction of remission with intravenous immunoglobulin and cyclophosphamide in steroid-resistant Evans' syndrome associated with dermatomyositis

Evans' syndrome is characterised by the simultaneous or sequential occurrence of Coombs'-positive haemolytic anaemia (AIHA) and immune thrombocytopenia without underlying aetiology. It has been found to be associated with collagen vascular diseases, especially systemic lupus erythematosus (SLE) and scleroderma. However, Evans' syndrome with dermatomyositis is very rare. A 59-year-old woman, who had been taking high-dose prednisolone for a month and cyclosporin for 10 days for dermatomyositis, developed purpura on the left popliteal fossa. The platelet and haemoglobin levels decreased to 77,000/mm3 and 9.8 g/dl, respectively. Antiplatelet antibody was positive. Thrombocytopenia responded to intravenous immunoglobulin (IVIG) for a short time, but further decreased in a week. Her blood film showed features of haemolytic anaemia. Laboratory findings showed reticulocytosis and a positive direct Coombs' test. Bone marrow examination showed a mild hyperplasia of erythroid precursors and megakaryocytes. The patient was successfully treated with cyclophosphamide in addition to oral prednisolone. AIHA in connective tissue disease may develop gradually and show a benign clinical course in most patients. Therefore, we suggest that patients with dermatomyositis and anaemia should always be checked for haemolysis if there is no other explanation.

Refractive changes of congenital entropion and epiblepharon on surgical correction

In order to investigate the refractive error, amblyopic frequency, and refractive change, if any, following recovery of cornea injury through surgery of epiblepharon and congenital entropion patients, we retrospectively reviewed the sex distribution, age at operation, chief complaints, preoperative and postoperative refractive errors, and best corrected visual acuity in 160 previously operated patients. The average age at operation was 7.9 years. The preoperative best corrected visual acuity of 133 eyes (41.6%) was below 5/9. Ninety-five eyes (29.7%) were preoperative myopes above -1.0D; 77 eyes (24%) were hyperopes above +1.0D; and 163 eyes were astigmatic above -1.0D. Of 228 eyes that were followed up for more than one year, 66 eyes demonstrated a best corrected visual acuity of below 5/9. There was no significant difference in the change in corneal astigmatism following surgery between the group under the age of 7 and the group over the age of 7. However, the mean best corrected visual acuity at postoperative one year was 6/9, which was significantly different from the preoperative value (P=0.006). Concurrent postoperative glasses correction and amblyopic therapy is indicated because the incidence of refractive errors and amblyopia is higher in epiblepharon and congenital entropion.

Inhibition of prostaglandin E2 production by platycodin D isolated from the root of Platycodon grandiflorum

Platycodin D, isolated from the root of Platycodon grandiflorum A. DC. (Campanulaceae) suppressed prostaglandin E2 production at 10 and 30 microM in rat peritoneal macrophages stimulated by the protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA). Platycodin D3 and oleanolic acid showed no effect at these concentrations. Western blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by platycodin D in parallel with the inhibition of prostaglandin E2 production. Platycodin D showed no direct effect on COX-1 and COX-2 activities. TPA-induced release of [3H]arachidonic acid from pre-labeled macrophages was also not inhibited by platycodin D.

Density of states, Potts zeros, and Fisher zeros of the Q-state Potts model for continuous Q

The Q-state Potts model can be extended to noninteger and even complex Q by expressing the partition function in the Fortuin-Kasteleyn (F-K) representation. In the F-K representation the partition function Z(Q,a) is a polynomial in Q and v=a-1 (a=e(betaJ)) and the coefficients of this polynomial, Phi(b,c), are the number of graphs on the lattice consisting of b bonds and c connected clusters. We introduce the random-cluster transfer matrix to compute Phi(b,c) exactly on finite square lattices with several types of boundary conditions. Given the F-K representation of the partition function we begin by studying the critical Potts model Z(CP)=Z(Q,a(c)(Q)), where a(c)(Q)=1+square root[Q]. We find a set of zeros in the complex w=square root[Q] plane that map to (or close to) the Beraha numbers for real positive Q. We also identify Q(c)(L), the value of Q for a lattice of width L above which the locus of zeros in the complex p=v/square root[Q] plane lies on the unit circle. By finite-size scaling we find that 1/Q(c)(L)-->0 as L-->infinity. We then study zeros of the antiferromagnetic (AF) Potts model in the complex Q plane and determine Q(c)(a), the largest value of Q for a fixed value of a below which there is AF order. We find excellent agreement with Baxter's conjecture Q(AF)(c)(a)=(1-a)(a+3). We also investigate the locus of zeros of the ferromagnetic Potts model in the complex Q plane and confirm that Q(FM)(c)(a)=(a-1)(2). We show that the edge singularity in the complex Q plane approaches Q(c) as Q(c)(L) approximately Q(c)+AL(-y(q)), and determine the scaling exponent y(q) for several values of Q. Finally, by finite-size scaling of the Fisher zeros near the antiferromagnetic critical point we determine the thermal exponent y(t) as a function of Q in the range 2</=Q</=3. Using data for lattices of size 3</=L</=8 we find that y(t) is a smooth function of Q and is well fitted by y(t)=(1+Au+Bu2)/(C+Du) where u=-(2/pi)cos(-1)(squareroot[Q]/2). For Q=3 we find y(t) approximately 0.6; however if we include lattices up to L=12 we find y(t) approximately 0.50(8) in rough agreement with a recent result of Ferreira and Sokal [J. Stat. Phys. 96, 461 (1999)].

Protective role of superoxide dismutases against ionizing radiation in yeast

The protective role of superoxide dismutases (SODs) against ionizing radiation, which generates reactive oxygen species (ROS) harmful to cellular function, was investigated in the wild-type and in mutant yeast strains lacking cytosolic CuZnSOD (sod1Delta), mitochondrial MnSOD (sod2Delta), or both SODs (sod1Deltasod2Delta). Upon exposure to ionizing radiation, there was a distinct difference between these strains in regard to viability and the level of protein carbonyl content, which is the indicative marker of oxidative damage to protein, intracellular H2O2 level, as well as lipid peroxidation. When the oxidation of 2',7'-dichlorofluorescin was used to examine the hydroperoxide production in yeast cells, the SOD mutants showed a higher degree of increase in fluorescence upon exposure to ionizing radiation as compared to wild-type cells. These results indicated that mutants deleted for SOD genes were more sensitive to ionizing radiation than isogenic wild-type cells. Induction and inactivation of other antioxidant enzymes, such as catalase, glucose 6-phosphate dehydrogenase, and glutathione reductase, were observed after their exposure to ionizing radiation both in wild-type and in mutant cells. However, wild-type cells maintained significantly higher activities of antioxidant enzymes than did mutant cells. These results suggest that both CuZnSOD and MnSOD may play a central role in protecting cells against ionizing radiation through the removal of ROS, as well as in the protection of antioxidant enzymes.

Poly(ethylene glycol)-poly(L-lactide) diblock copolymer prevents aggregation of poly(L-lactide) microspheres during ethylene oxide gas sterilization

Sterilization procedure is one of the most important obstacles in the clinical applications of biodegradable microspheres. The microspheres prepared with poly(alpha-hydroxy acid) were severely aggregated during ethylene oxide (EO) gas sterilization, and could not be used in clinical applications. In this study, the effects of EO gas sterilization on the poly(L-lactide) (PLLA) microspheres were analyzed by nuclear magnetic resonance spectroscopy (1H-NMR), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), scanning electron microscope (SEM) and size fractionation. The aggregation between the microspheres might be stimulated by high mobility of amorphous regions of PLLA on the microsphere surfaces since both water vapor and gas mixture can reduce glass transition temperature (Tg) of PLLA below the sterilization temperature. During EO gas sterilization, there were no changes in the molecular structure and the molecular weight of PLLA in microspheres, but there were changes in the crystallinity of PLLA in microspheres. In this study, poly(L-lactide)-poly(ethylene glycol) diblock copolymers (PLE) were blended with PLLA homopolymers in various ratios to design the microsphere suitable for EO gas sterilization. Aggregation of PLLA microspheres was markedly prevented when more than 4wt% of PLE was blended in the microspheres. This inhibition effect on aggregation may be due to the increased initial crystallinity of the microspheres, which help to maintain the microsphere morphology during EO gas sterilization.

Assessing the competence of persons with Alzheimer's disease in providing informed consent for participation in research

OBJECTIVE

The capacity of persons with Alzheimer's disease or other neuropsychiatric disorders for giving consent to participate in research has come under increasing scrutiny. While instruments for measuring abilities related to capacity have been developed, how they should be used to categorize subjects as capable or incapable is not clear. A criterion validation study was carried out to help address this question.

METHOD

The authors measured the ability of 37 subjects with mild-to-moderate Alzheimer's disease and 15 elderly comparison subjects to provide consent for participation in a hypothetical clinical trial. Using the judgment of three experts as the criterion standard, the authors performed a receiver operator characteristic analysis for the capacity ability measures from the MacArthur Competence Assessment Tool-Clinical Research VERSION: The results were compared with categorizations of capacity status that were based on normative values.

RESULTS

While most comparison subjects scored perfectly on all measures of the competence assessment tool, the majority of the group with Alzheimer's disease showed significant decision-making impairment. Thresholds based on normative values resulted in 84% (N=31) of the Alzheimer's disease subjects being rated as incapable on at least one ability; thresholds based on expert judgment resulted in 62% (N=23) failing to meet cutoff scores on at least one ability.

CONCLUSIONS

Even relatively mild Alzheimer's disease significantly impairs consent-giving capacity. But differentiating capable from incapable subjects remains an issue despite the aid of standardized tools. More research is needed to understand the relationship between subject factors (performance on ability measures) and categorical judgments about their capacity.

An improved strategy for a genetic assay for site-specific proteolysis

We have previously reported a genetic assay that is suitable for the study of substrate specificity of a protease in vivo, and herein present a simplified version of the method. In this procedure, expressed in Saccharomyces cerevisiae by using the constitutive alcohol dehydrogenase promoter is a fusion protein in which a transcription factor is linked to the intracellular domain of an integral membrane protein by a protease substrate sequence. Following this, a protease is expressed by using the inducible GAL promoter in the same yeast cells. The cleavage of the substrate sequence by the specific protease results in the release of the transcription factor and subsequent activation of reporter genes in nucleus. Since the expression of a protease is strictly under the control of the inducible GAL promoter, false substrate sequences that are cleaved by endogenous yeast proteases can be easily recognized and eliminated from further characterization. This suggests that the modified strategy provides an efficient tool for the analysis of substrate sequences of a protease in vivo.

Morphology of calretinin and tyrosine hydroxylase-immunoreactive neurons in the pig retina

The morphology of calretinin- and tyrosine hydroxylase-immunoreactive (IR) neurons in adult pig retina was studied. These neurons were identified using antibody immunocytochemistry. Calretinin immunoreactivity was found in numerous cell bodies in the ganglion cell layer. Large ganglion cells, however, were not labeled. In the inner nuclear layer, the regular distribution of calretinin-IR neurons, the inner marginal location of their cell bodies in the inner nuclear layer, and the distinctive bilaminar morphologies of their dendritic arbors in the inner plexiform layer suggested that these calretinin-IR cells were AII amacrine cells. Calretinin immunoreactivity was observed in both A-and B-type horizontal cells. Neurons in the photoreceptor cell layer were not labeled by this antibody. The great majority of tyrosine hydroxylase-IR neurons were located at the innermost border of the inner nuclear layer (conventional amacrines). The processes were monostratified and ran laterally within layer 1 of the inner plexiform layer. Some of the tyrosine hydroxylase-IR neurons were located in the ganglion cell layer (displaced amacrines). The processes of displaced tyrosine hydroxylase-IR amacrine cells were also located within layer 1 of the inner plexiform layer. Some processes of a few neurons were located in the outer plexiform layer. A very low density of neurons had additional bands of tyrosine hydroxylase-IR processes in the middle and deep layers of the inner plexiform layer. The processes of tyrosine hydroxylase-IR neurons extended radially over a wide area and formed large, moderately branched dendritic fields. These processes occasionally had varicosities and formed "dendritic rings". These results indicate that calretinin- and tyrosine hydroxylase-IR neurons represent specific neuronal cell types in the pig retina.

Vanilloid and isovanilloid analogues as inhibitors of methionyl-tRNA and isoleucyl-tRNA synthetases

As aminoacyl adenylate surrogates, a series of methionyl and isoleucyl phenolic analogues containing bioisosteric linkers mimicking ribose have been investigated. Inhibition of synthesized compounds to the aminoacylation reaction by the corresponding Escherichia coli methionyl-tRNA and isoleucyl-tRNA synthetases indicated that 18 was found to be a potent inhibitor of isoleucyl-tRNA synthetase. A molecular modeling study demonstrated that in 18, isovanillate and hydroxamate served as proper surrogates for adenine and ribose in isoleucyl adenylate, respectively.

Ester and hydroxamate analogues of methionyl and isoleucyl adenylates as inhibitors of methionyl-tRNA and isoleucyl-tRNA synthetases

The structure activity relationship on a series of ester and hydroxamate analogues of methionyl and isoleucyl adenylate has been investigated through introducing linkers between the 1'-position of ribose and adenine surrogates as methionyl-tRNA, and isoleucyl-tRNA synthetase inhibitors, respectively. The results indicate that ester analogue 23 was found to be a potent inhibitor of Escherichia coli methionyl-tRNA synthetase, and its interaction with the active site was proposed by a molecular modeling study.

Centrality dependence of charged particle multiplicity in Au-Au collisions at square root of (s)NN = 130 GeV

We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions at square root of [s(NN)] = 130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find dN(ch)/d eta(vertical line eta = 0) = 622+/-1(stat)+/-41(syst). The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.

Serum 8-hydroxy-guanine levels are increased in diabetic patients

OBJECTIVE

The production of reactive oxygen species is increased in diabetic patients, especially in those will poor glycemic control. We have investigated oxidative damage in type 2 diabetic patients using serum 8-hydroxyguanine (8-OHG) as a biomarker.

RESEARCH DESIGN AND METHODS

We studied 41 type 2 diabetic patients and compared them with 3 nondiabetic control subjects. Serum 8-OHG concentration was assayed using high-pressure liquid chromatography.

RESULTS

The type 2 diabetic patients had significantly higher concentrations of 8-OHG in their serum than the control subjects (5.03 +/- 0.69 vs. 0.96 +/- 0.15 pmol/ml P < 0.01). There was no association between the levels of 8-OHG and HbA1c. We also could not and any correlation between serum 8-OHG levels and age, duration of diabetes, serum lipids, or creatinine or albumin exeretion rate. Creatinine clearance showed marginal correlation with serum 8-OHG levels (P = 0.06). Among the diabetic patients, those with proliferative retinopathy had significantly higher 8-OHG levels than those with nonproliferative retinopathy or without retinopathy. Likewise, the serum 8-OHG levels in patients who had advanced nephropathy (azotemia) were higher than in patients with normoalbuminuria, microalbuminuria, or overt proteinuria.

CONCLUSIONS

Our findings show that measuring serum 8-OHG is a novel convenient method for evaluating oxidative DNA damage. Diabetic patients, especially those with advanced microvascular complications, had significantly higher serum 8-OHG levels; this suggests that such changes may contribute to the development of microvascular complications of diabetes.

Ceramide inhibits cell proliferation through Akt/PKB inactivation and decreases melanin synthesis in Mel-Ab cells

Ceramide is a bioactive sphingolipid that mediates a variety of cell functions. However, the effects of ceramide on cell growth and the melanogenesis of melanocytes are not known. In the present study, we investigated the actions of cell-permeable ceramide and its possible role in the signaling pathway of a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Our results show that C2-ceramide inhibits DNA synthesis in Mel-Ab cells and G361 human melanoma cells in a dose-dependent manner. Cell cycle analysis confirmed the inhibition of DNA synthesis by a reduction in the S phase. To investigate the ceramide signaling pathway, we studied whether C2-ceramide is able to influence extracellular signal-regulated kinase (ERK) and/or Akt/protein kinase B (PKB) activation. We demonstrated that phosphorylated Akt/PKB is decreased by C2-ceramide, whereas phosphorylated ERK was only slightly affected. Therefore, the C2-ceramide-induced inactivation of Akt/PKB may be closely related to the reduced cell proliferation of Mel-Ab cells. Furthermore, we assessed the effects of C2-ceramide on the pigmentation of Mel-Ab cells. The results obtained showed that the melanin content of cells was significantly reduced by C2-ceramide at concentrations in the range of 1-10 microM, and that the pigmentation-inhibiting effect of C2-ceramide is much greater than that of kojic acid at 1-100 microM. In addition, we found that the activity of tyrosinase is reduced by C2-ceramide treatment. Our results demonstrate that C2-ceramide reduces the pigmentation of Mel-Ab cells by inhibiting tyrosinase activity.

Clinical impacts of tumor cell contamination of hematopoietic stem cell products in metastatic breast cancer patients undergoing autologous peripheral blood stem cell transplantation: multicenter trial

To determine whether the tumor cell contamination of peripheral blood stem cells influences clinical impacts on high-dose chemotherapy in patients with metastatic breast cancer, we analyzed carcinoembryonic antigen (CEA) mRNA in the apheresis products by nested RT-PCR (reverse transcriptase-polymerase chain reaction). A total of 38 metastatic breast cancer patients and ten normal healthy subjects as a negative control were included. Twenty out of 38 (51.3%) apheresis products from patients with metastatic breast cancer were positive for CEA mRNA. CEA mRNA was noted in 54.8% (17/31) of patients mobilized with chemotherapy plus G-CSF and 42.8% (3/7) of patients with G-CSF alone. There was no significant difference in age, estrogen receptor, menopausal status, mobilization method, disease free interval, or number of metastasis sites (1 vs > or = 2) between positive and negative groups. The presence of CEA mRNA in apheresis products did not influence the time to progression and overall survival in both groups. However, both the univariate and the multivariate analysis disclosed that the number of metastasis was associated with survival significantly. We suggest that the tumor cell contamination does not predict poor treatment outcome in patients with metastatic breast cancer.

Nuclear localization of beta-catenin is an important prognostic factor in hepatoblastoma

In this study, mutational and immunohistochemical analyses of beta-catenin were performed in 30 hepatoblastomas, to assess the prevalence of alterations of the Wnt pathway with respect to clinicopathological parameters and survival. Four missense mutations of beta-catenin (13.3%) were detected and there was strong immunoreactivity for beta-catenin in the cytoplasm and/or the nucleus in 97% of hepatoblastomas. Nuclear and cytoplasmic staining was demonstrated in 19 of 30 tumours (63%), while ten revealed only cytoplasmic staining. Statistically, this nuclear beta-catenin staining was significantly higher in the embryonal (Fisher exact test; p=0.00393) or undifferentiated type (p=0.00156) of hepatoblastoma than in the fetal type, but there was no difference between clinical stages I and II and clinical stages III and IV (p=0.175). Cumulative survival curves showed that nuclear beta-catenin staining (generalized Wilcoxon test; p=0.0088), undifferentiated histological type (p=0.0305), and clinical stages III and IV (p=0.0107) were significantly correlated with shorter survival time in these patients. Moreover, Cox multivariate analysis provides evidence that nuclear beta-catenin staining is the most important prognostic factor for survival (p=0.0090). It is therefore concluded that immunohistochemical analysis of beta-catenin might be a useful clinical tool for estimating the prognosis for patients with hepatoblastoma.

Increased erythritol production in fed-batch cultures of Torula sp. by controlling glucose concentration

The effect of glucose concentration on erythritol production by Torula sp. was investigated. The maximum volumetric productivity of erythritol was obtained at an initial glucose concentration of 300 g l(-1) in batch culture. The volumetric productivity was maximal at a controlled glucose concentration of 225 g l(-1), reducing the lag time of the erythritol production. A fed-batch culture was established with an initial glucose concentration of 300 g l(-1) and with a controlled glucose concentration of 225 g l(-1) in medium containing phytic acid as a phosphate source. In this fed-batch culture, a final erythritol production of 192 g l(-1) was obtained from 400 g l(-1) glucose in 88 h. This corresponded to a volumetric productivity of 2.26 g l(-1) h(-1) and a 48% yield.

Fatty acid patterns in gastric mucosa of stomach cancer patients

omega6 and omega3 fatty acids are important cellular components and known to be involved in disease processes. However, few studies have focused on mucosa fatty acid in human gastric cancer. The purpose of this study was to investigate how fatty acid patterns of mucosa are altered in gastric cancer. Fatty acids were analyzed by gas chromatography and their relative compositions (%) were determined and evaluated both in mucosa total-fatty acids and in phospholipid-fatty acids in paired cancerous and non-cancerous gastric cancer tissues (n = 18). The level of arachidonic acid (20:4omega6, AA) appeared significantly higher both in phospholipid-fatty acids (p < 0.05) and in total-fatty acids (p < 0.001) in cancerous mucosa compared to non-cancerous mucosa. The omega6/omega3 fatty acid ratio of phospholipid-fatty acids was also significantly higher in cancerous mucosa. The higher level of AA in cancerous tissue can be partially explained by the higher ratio of 20:4omega 6/20:3omega6 (desaturation index) and the lower ratio of 22:4omega6/20:4 omega6 (elongation index). The change in the relative composition of arachidonic acid may influence the production of prostaglandins and related metabolites, which regulate cell differentiation and proliferation. The findings of this study with respect to fatty acid changes, especially in terms of arachidonic acid metabolism, may be of relevance in the understanding of the roles of specific fatty acids and possibly of eicosanoids in gastric cancer.

Cloning and characterization of the Hansenula polymorpha homologue of the Saccharomyces cerevisiae MNN9 gene

A gene homologous to Saccharomyces cerevisiae MNN9 has been cloned and characterized in the methylotrophic yeast Hansenula polymorpha. This gene was cloned from a H. polymorpha genomic DNA library using the S. cerevisiae MNN9 gene as a probe. The H. polymorpha MNN9 homologue (HpMNN9) contained a 1062 bp open reading frame encoding a predicted protein of 354 amino acids. The deduced amino acid sequence showed 58% and 51% identity, respectively, with the S. cerevisiae and Candida albicans Mnn9 proteins. Disruption of HpMNN9 leads to phenotypic effects suggestive of cell wall defects, including detergent sensitivity and hygromycin B sensitivity. The hygromycin B sensitivity of S. cerevisiae mnn9 null mutant was complemented in the presence of the HpMNN9 gene. The DNA sequence of the H. polymorpha homologue has been submitted to GenBank with the Accession No. AF264786.

Wegener's granulomatosis presenting as mediastinal soft tissue mass invading the tracheal wall

Wegener's granulomatosis (WG) is a clinicopathologic entity of unknown cause characterised by a necrotising granulomatous vasculitis affecting multiple organs, especially the upper and lower respiratory tracts, lung and kidney. The lung is the most frequently, and sometimes the only involved organ. Single or multiple nodules, with or without cavitation, are the most common pulmonary manifestations in WG, but mediastinal involvement is atypical. The sole tracheal involvement is rare and hilar and mediastinal involvement has been thought not to be part of the clinical feature. We experienced a rare case of WG presenting as paratracheal mediastinal lesions with tracheal wall invasion, which responded dramatically to corticosteroid treatment. We present this case with a review of the literature.

Burkitt's lymphoma presenting as ileocaecal intussusception in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) are reported to have an increased risk of malignancy, especially lymphoproliferative disorders. We decribe the occurrence of ileocaecal intussusception secondary to Burkitt's lymphoma in a patient with SLE. A 23-year-old woman, who had been diagnosed with SLE 2 years ago, developed intermittent abdominal pain with a palpable mass. Computed tomography and a double-contrast barium enema showed a lobulated mass with intussusception at the ileocaecal junction. Right hemicolectomy and splenectomy was performed after histopathological examinations on colonoscopic biopsy revealed Burkitt's lymphoma. Fourteen months after chemotherapy, there is no evidence of recurrence of the Burkitt's lymphoma. When a patient with SLE has abdominal complaints, besides serositis, lupus enteritis such as peptic ulcer disease, mesenteric vasculitis with or without complications and pancreatitis, we have to consider intussusception secondary to gastrointestinal lymphoma as one of the differential diagnoses. Therefore, we should thoroughly investigate patients with SLE presenting with abdominal pain and not simply consider it afeature of lupus enteritis until other causes have been ruled out.

Induction of early growth response-1 gene expression by calmodulin antagonist trifluoperazine through the activation of Elk-1 in human fibrosarcoma HT1080 cells

The early growth response gene-1 (Egr-1) is a transcription factor that plays an important role in cell growth and differentiation. It has been known that Egr-1 expression is down-regulated in many types of tumor tissues, including human fibrosarcoma HT1080 cells, and introduction of the Egr-1 gene into HT1080 cells inhibits cell growth and tumorigenic potential. Trifluoperazine (TFP), a phenothiazine class calmodulin antagonist, is known to inhibit DNA synthesis and cell proliferation and potentially important in antitumor activities. To understand the regulatory mechanism of Egr-1, we investigated the effect of TFP on expression of Egr-1 in HT1080 cells. Herein, we report that Egr-1 expression was increased by TFP in synergy with serum at the transcriptional level. Both the Ca(2+)/calmodulin-dependent protein kinase II inhibitor KN62 and the calcineurin inhibitor cyclosporin A enhanced TFP-dependent increase of Egr-1, suggesting that the Ca(2+)/calmodulindependent pathway plays a role in regulation of Egr-1 expression in HT1080 cells. The TFP-stimulated increase of the Egr-1 protein was preferentially inhibited by the MEK-specific inhibitor PD98059. In addition, activation of human Egr-1 promoter and the transcriptional activation of the ternary complex factor Elk-1 induced by TFP were inhibited both by pretreatment of PD98059 and by expression of the dominant-negative RasN17. These results indicate that the Ras/MEK/Erk/Elk-1 pathway is necessary for TFP-induced Egr-1 expression. We propose that the calmodulin antagonist TFP stimulates Egr-1 gene expression by modulating Ras/MEK/Erk and activation of the Elk-1 pathway in human fibrosarcoma HT1080 cells.

Effect of total sleep deprivation on the dimensional complexity of the waking EEG

STUDY OBJECTIVES

Sleep deprivation can affect the waking EEG that may reflect information processing of the brain. We examined the effect of total sleep deprivation (TSD) on nonlinear dynamics of the waking EEG.

DESIGN

Paired-group design.

SETTING

A sleep disorders laboratory in a hospital.

PARTICIPANTS

Twenty healthy male volunteers.

INTERVENTIONS

Waking EEG data were recorded from subjects with eyes closed after (a) an 8-hour night's sleep and (b) TSD for 24 hours. The dimensional complexity (D2), as a nonlinear measure of complexity, of the EEG after a full night sleep were compared with those of the EEG after TSD.

MEASUREMENTS AND RESULTS

The sleep-deprived states had lower D2 values at three channels (P4, O2, and C3) than normal states.

CONCLUSIONS

TSD results in the decrease of complexity in the brain, which may imply sub-optimal information processing of the cerebral cortex. We suggest that the investigation of the relation between nonlinear dynamics of the waking EEG induced by TSD and cognitive performance may offer fruitful clues for understanding the role of sleep and the effects of sleep deprivation on brain function.

Long-term delivery of all-trans-retinoic acid using biodegradable PLLA/PEG-PLLA blended microspheres

All-trans-retinoic acid (atRA) has been proved to be effective against several malignancies in human clinical trials. However, in many patients who were treated with atRA, the cancer relapsed after a brief remission. One reason for such relapse is that atRA is metabolized by specific P450s that are induced in the liver during prolonged atRA treatments. In order to overcome such a drawback of atRA, we prepared biodegradable microspheres to provide continuous release of atRA for a long period of time. These biodegradable microspheres were prepared by poly(L-lactide) (PLLA) and polyethylene glycol (PEG)-PLLA diblock copolymers (PLE) in various blending ratios to control the release rate of atRA. As the PLE content in microsphere was increased, the density of the hydrophilic PEG block of PLE on microsphere surfaces increased and the microspheres were dispersed well in PBS without any surfactants. Various release patterns of atRA were obtained according to PLE and atRA contents in the microspheres. Especially, the pseudo-zero-order release profiles were observed for 5 weeks when the contents of PLE and atRA in the microspheres were above 4 wt.%.

Baryon rapidity loss in relativistic Au + Au collisions

An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8 GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that display a broad peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a stationary source at midrapidity decreases with increasing beam energy. The data suggest that the stopping is substantially less than complete at these energies.