LPS receptor subunits have antagonistic roles in epithelial apoptosis and colonic carcinogenesis.

Colorectal carcinoma (CRC) is characterized by unlimited proliferation and suppression of apoptosis, selective advantages for tumor survival, and chemoresistance. Lipopolysaccharide (LPS) signaling is involved in both epithelial homeostasis and tumorigenesis, but the relative roles had by LPS receptor subunits CD14 and Toll-like receptor 4 (TLR4) are poorly understood. Our study showed that normal human colonocytes were CD14(+)TLR4(-), whereas cancerous tissues were CD14(+)TLR4(+), by immunofluorescent staining. Using a chemical-induced CRC model, increased epithelial apoptosis and decreased tumor multiplicity and sizes were observed in TLR4-mutant mice compared with wild-type (WT) mice with CD14(+)TLR4(+) colonocytes. WT mice intracolonically administered a TLR4 antagonist displayed tumor reduction associated with enhanced apoptosis in cancerous tissues. Mucosa-associated LPS content was elevated in response to CRC induction. Epithelial apoptosis induced by LPS hypersensitivity in TLR4-mutant mice was prevented by intracolonic administration of neutralizing anti-CD14. Moreover, LPS-induced apoptosis was observed in primary colonic organoid cultures derived from TLR4 mutant but not WT murine crypts. Gene silencing of TLR4 increased cell apoptosis in WT organoids, whereas knockdown of CD14 ablated cell death in TLR4-mutant organoids. In vitro studies showed that LPS challenge caused apoptosis in Caco-2 cells (CD14(+)TLR4(-)) in a CD14-, phosphatidylcholine-specific phospholipase C-, sphingomyelinase-, and protein kinase C-ζ-dependent manner. Conversely, expression of functional but not mutant TLR4 (Asp299Gly, Thr399Ile, and Pro714His) rescued cells from LPS/CD14-induced apoptosis. In summary, CD14-mediated lipid signaling induced epithelial apoptosis, whereas TLR4 antagonistically promoted cell survival and cancer development. Our findings indicate that dysfunction in the CD14/TLR4 antagonism may contribute to normal epithelial transition to carcinogenesis, and provide novel strategies for intervention against colorectal cancer.

Multi-walled carbon nanotube-supported metal-doped ZnO nanoparticles and their photocatalytic property.

A simple and versatile approach has been developed to synthesize multi-walled carbon nanotubes/metal-doped ZnO nanohybrid materials (MWNT/M-doped ZnO) by means of the co-deposition method. The experimental results illuminate that MWNTs can be modified by metal-doped ZnO nanoparticles at 450 °C, such as Mn, Mg, and Co elements. Furthermore, the MWNT/Mg-doped ZnO hybrids have been proven to have a high photocatalytic ability for methyl orange (MO), in which the degraded rate for MO reaches 100 % in 60 min. The enhancement in photocatalytic activity is attributed to the excellent electriconal property of MWNTs and Mg-doping. The resultant MWNT/Mg-doped ZnO nanohybrids have potential applications in photocatalysis and environmental protection.

Cordyceps militaris and mycelial fermentation induced apoptosis and autophagy of human glioblastoma cells.

This study is the first report that investigated the apoptosis-inducing effects of Cordyceps militaris (CM) and its mycelial fermentation in human glioblastoma cells. Both fractions arrested the GBM8401 cells in the G0/G1 phase, whereas the U-87MG cells were arrested at the G2/M transitional stage. Western blot data suggested that upregulation of p53 and p21 might be involved in the disruption of cell cycle progression. Induction of chromosomal condensation and the appearance of a sub-G1 hypodipoid population further supported the proapoptogenicity, possibly through the activation of caspase-3 and caspase-8, and the downregulation of antiapoptotic Bcl-2 and the upregulation of proapoptotic Bax protein expression. Downregulation of mammalian target of rapamycin and upregulation of Atg5 and LC3 II levels in GBM8401 cells implicated the involvement of autophagy. The signaling profiles with mycelial fermentation treatment indicated that mycelial fermentation triggered rapid phosphorylation of Akt, p38 MAPK, and JNK, but suppressed constitutively high levels of ERK1/2 in GBM8401 cells. Mycelial fermentation treatment only significantly increased p38 MAPK phosphorylation, but decreased constitutively high levels of Akt, ERK1/2, and JNK phosphorylation in U-87MG cells. Pretreatment with PI3K inhibitor wortmannin and MEK1 inhibitor PD98059 prevented the mycelial fermentation-induced cytotoxicity in GBM8401 and U-87MG cells, suggesting the involvement of PI3K/Akt and MEK1 pathways in mycelial fermentation-driven glioblastoma cell apoptosis and autophagy.

Multi-walled carbon nanotubes supported Cu-doped ZnO nanoparticles and their optical property.

Multi-walled carbon nanotubes (MWNTs)/Cu-doped ZnO composite powders were prepared by co-precipitation method, and were characterized by X-ray diffraction, electron microscopy, fluorescence spectrum, and ultraviolet spectrum. Experimental results show that the MWNTs can be modified by Cu-doped ZnO nanoparticles with hexagonal wurtzite structure after annealed at 450 °C, and the nanoparticle size is about 15 nm. Two ultraviolet (UV) peaks and a green band centered at about 510 nm are observed in the fluorescence spectrum of MWNTs/Cu-doped ZnO composite powder annealed at 450 °C. Furthermore, MWNTs and Cu doping significantly improve the UV absorption ability of ZnO.

Self-assembled silicon oxide nanojunctions.

Novel silicon oxide nanojunction structures with various shapes, such as X type, Y type, T type, ringlike and treelike, are fabricated in a self-assembled manner by the hydrothermal method without any metallic catalyst. In the silicon oxide nanojunctions, both the silicon oxide nanowire part and the junction part consist of the same chemical composition, forming homogeneous homojunctions and being made suitable for application in nanoscale optoelectronics devices. The formation of silicon oxide nanojunctions may be influenced by the surrounding environment in the reaction kettle, growth space among the silicon oxide nanowires and the weight of SiO droplets at the growth tip.

Regular Tai Chi Chuan exercise improves T cell helper function of patients with type 2 diabetes mellitus with an increase in T-bet transcription factor and IL-12 production.

BACKGROUND: Exercise has been shown to be beneficial in the treatment of type 2 diabetes mellitus (DM); its benefit to immune function, however, remains to be determined. OBJECTIVE: This study investigated the effect of a 12-week course of Tai Chi Chuan (TCC) exercise on T cell helper (Th) reaction in patients with type 2 DM. METHODS: A case-control study was performed in 30 pairs of patients with type 2 DM and normal age-matched adults. Fasting blood glucose, HbA1c, mediators (interleukin (IL)-12, IL-4 and transforming growth factor (TGF)beta) and transcription factors (T-bet, GATA-3 and FoxP3) of Th1/Th2/T regulatory (Treg) reaction were measured before and after a 12-week TCC exercise programme. RESULTS: Fasting glucose and HbA1c levels in the patients with type 2 DM were significantly higher than in age-matched controls before exercise. After TCC exercise, HbA1c levels in patients with type 2 DM significantly decreased (7.59 (0.32)% vs 7.16 (0.22)%; p = 0.047) and blood levels of IL-12 increased significantly (5.96 (1.10) vs 12.96 (3.07); p = 0.035). To study the molecular Th1/Th2/Treg reaction, patients with type 2 DM were found to have lower T-bet but not GATA-3 or FoxP3 expression than normal controls before TCC exercise. After the 12-week TCC exercise T-bet expression significantly increased in patients with type 2 DM. CONCLUSIONS: A 12-week TCC exercise programme decreases HbA1c levels along with an increase in the Th1 reaction. A combination of TCC with medication may provide an even better improvement in both metabolism and immunity of patients with type 2 DM.

Atypical manifestation of Vibrio vulnificus septicaemia.

Vibrio vulnificus is a Gram-negative marine bacterium that may cause local wound infection, gastroenteritis, or septicaemia. Fatal septicaemia usually presents with fever, shock, and large haemorrhagic bullae on the legs. This report is about a man who had severe V. vulnificus septicaemia but presented with atypical features of leg pain and diffuse purpuric skin lesions. V. vulnificus septicaemia should be suspected if the following are present: septic shock, leg pains associated with diffuse purpuric skin lesions, recent consumption of raw seafood, and a past medical history of liver cirrhosis.

Regular tai chi chuan exercise enhances functional mobility and CD4CD25 regulatory T cells.

BACKGROUND: The duration and vigour of physical exercise are widely considered to be critical elements that may positively or negatively affect physical health and immune response. OBJECTIVES: To investigate the effect of a 12 week programme of regular tai chi chuan exercise (TCC) on functional mobility, beliefs about benefits of exercise on physical and psychological health, and immune regulation in middle aged volunteers. METHODS: This quasi-experimental research design involving one group with testing before and after the programme was conducted to measure the effect of 12 weeks of TCC exercise in 14 men and 23 women from the normal community. RESULTS: Regular TCC exercise had a highly significant positive effect on functional mobility (p = 0.001) and beliefs about the health benefits of exercise (p = 0.013) in the 37 participants. Total white blood cell and red blood cell count did not change significantly, but a highly significant (p<0.001) decrease in monocyte count occurred. A significant (p = 0.05) increase in the ratio of T helper to suppressor cells (CD4:CD8) was found, along with a significant (p = 0.015) increase in CD4CD25 regulatory T cells. Production of the regulatory T cell mediators transforming growth factor beta and interleukin 10 under specific antigen stimulation (varicella zoster virus) was also significantly increased after this exercise programme. CONCLUSIONS: A 12 week programme of regular TCC exercise enhances functional mobility, personal health expectations, and regulatory T cell function.

[The outcomes of restraint reduction program in nursing homes].

One of the problems in nursing home care in Taiwan is resident restraint, including physical and chemical restraints. This pre-experimental study was conducted to investigate whether a restraint reduction program could reduce the prevalence of restraint in nursing homes. Three registered nursing homes were randomly selected from nursing homes in the Kaohsiung area. Staff and residents of these nursing homes were educated in restraint alternatives, balance training and managing behavior problems in one month of interventions. Three days before and after interventions, prevalence of restraints, falls, and of pressure sores, balance reaction, frequency of agitation, use of psychotic drugs, as well as the restraint knowledge of the nursing staff, was measured. After the restraint reduction program, the prevalence of restraint and frequency of resident agitation decreased significantly. The prevalence of falls and pressure sores of residents was not changed significantly. The restraint knowledge of the nursing staff significantly increased after the restraint reduction program. The information from this study led to a better strategy to reduce restraint for the elderly in nursing homes. The results could also provide a model to improve the quality of care in nursing homes in Taiwan.

Reversal caused by n-butylidenephthalide from the deficits of inhibitory avoidance performance in rats.

The present study was designed to investigate the mechanism of action of n-butylidenephthalide on the deficits of inhibitory avoidance performance induced by drugs in rats with piracetam as a positive control. n-Butylidenephthalide attenuated the scopolamine-induced and mecamylamine-induced acquisition impairment, and also attenuated the acquisition impairment induced by scopolamine plus mecamylamine. Furthermore, scopolamine methylbromide, a peripheral cholinergic muscarinic receptor antagonist, did not block the counteracting effect of n-butylidenephthalide on the scopolamine-induced acquisition impairment. n-Butylidenephthalide attenuated the impairment of inhibitory avoidance performance induced by the central acetylcholinergic neurotoxin AF64A administered intracisternally. From the above results, we suggest that n-butylidenephthalide attenuated the deficits of inhibitory avoidance performance induced by drugs, which are the effects related to activating the central but not the peripheral cholinergic neuronal system via muscarinic and nicotinic receptors.

The ameliorating effect of the water layer of Fructus Schisandrae on cycloheximide-induced amnesia in rats: interaction with drugs acting at neurotransmitter receptors.

Our previous study indicated that the water layer present in Fructus Schisandra(FS(w)) at 10 and 25 mg kg(-1)significantly counteracted cycloheximide (CXM)-induced amnesia. Therefore, the mechanism of action of the ameliorating effect of FS(w)on CXM-induced amnesia in the passive avoidance task was investigated in rats. The ameliorating effect of FS(w)on CXM-induced amnesia was depressed by scopolamine. The serotonin releaser, p -chloroamphetamine significantly antagonized the ameliorating effect of FS(w)on CXM-induced amnesia. Furthermore, the ameliorating effect was also inhibited by the 5-HT(1A)receptor agonist 8-OH-DPAT, but potentiated by the 5-HT(2)receptor antagonist ritanserin. Finally, the GABA(A)receptor antagonist bicuculline blocked the ameliorating effect of FS(w). These results suggest that the beneficial effect of FS(w)on CXM-induced amnesia is amplified by treatment with serotonergic 5-HT(2)receptor antagonists, but reduced by serotonergic 5-HT(1A)receptor agonists as well as GABA(A)and cholinergic receptor antagonists.

[Continuing education needs & knowledge of gerontological nursing among nurses in nursing homes].

The purpose of this study was to explore continuing education needs and knowledge of gerontological nursing among nurses in nursing homes, and analyze the relationship of demographic characteristics, knowledge and continuing education needs. Twenty nursing homes were randomly selected and 130 nurses were interviewed by structured questionnaires to ascertain their demographic characteristics, knowledge of gerontological nursing, and continuing education needs. Results showed that more than half of the nurses had not attended any courses in gerontological nursing in school, or in post-graduate continuing education. The rate of correct answers for knowledge of gerontological nursing was 70.8%. The worst knowledge was of gerontological statistics, followed by physical and psychological aspects of aging. Knowledge levels in gerontological nursing were positively correlated with age (r = .22, p < .05) having taken gerontological nursing courses (r =.22, p < .05) and having taken continuing education in gerontological nursing (r = .18, p < .05). Knowledge levels were negatively correlated with having lived with the elders in their own family (r = -.30, p < .05). Nurses who graduated from junior college or nursing high school had lower scores for knowledge than college graduates (F = 25.31, p < .001). The intensity level of continuing education needs ranged from needed to strongly needed, especially for knowledge regarding clinical care, followed by general information on aging, and administration and management. The level of continuing education needs was not different among the various demographic characteristics and knowledge levels in gerontological nursing. Results from this study suggest that gerontological nursing courses should be increased in nursing schools. Furthermore, a well-formulated continuing education model for gerontological nurses in nursing homes is also essential to promote the quality of care of the elderly.

A N(alpha)-acetyltransferase selectively transfers an acetyl group to NH2-terminal methionine residues: purification and partial characterization.

Methionine N(alpha)-acetyltransferase (M-N(alpha)AT), which selectively catalyzes the transfer of an acetyl group from acetyl coenzyme A to the alpha-NH2 group of methionine residues in proteins and peptides, was isolated from Saccharomyces cerevisiae. The enzyme was purified 22000-fold to apparent homogeneity by successive purification steps using DEAE-Sepharose, DE-52 cellulose, CM-52 cellulose, Affi-Gel Blue gel and hydroxyapatite. The Mr of the native enzyme was estimated to be 70000 +/- 5000 by gel filtration chromatography. The enzyme has a pI near 8.3 as determined by chromatofocusing on Mono P. The enzyme catalyzed the transfer of an acetyl group to a synthetic peptide mimicking the first 24 residues of yeast proteinase A inhibitor 3 (Met-Asn-Thr...) and 3 of its 19 penultimately substituted analogues ([Asp2], [Glu2], and [Gln2]). Based on the estimated molecular weight and amino-acid sequence, The enzyme is different from two other recently identified methionine N(alpha)-acetyltransferases, NAT2 (Kulkarni, M.S. and Sherman, F. (1994) J. Biol. Chem. 269, 13141-13147) and MAK3 (Tercero, J.C. and Wickner, R.B. (1992) J. Biol. Chem. 267, 20277-20281). Among these three enzymes, M-N(alpha)AT and NAT2 have similar substrate specificity, however, only purified M-N(alpha)AT, but not recombinant NAT2 gene product, can catalyze the transfer of acetyl group to NH2-terminal methionine residues. The availability of this methionine N(alpha)-acetyltransferase will advance the understanding of protein co-translational processing.

Acetyl-CoA hydrolase involved in acetate utilization in Saccharomyces cerevisiae.

Acetyl-CoA hydrolase, catalyzing the hydrolysis of acetyl-CoA, is presumably involved in regulating the intracellular acetyl-CoA or CoASH pools. The yeast enzyme is encoded by ACHl (acetyl-CoA hydrolase) and the expression of ACH1 is repressed by glucose (Lee, F.-J.S., Lin, L.-W. and Smith, J.A. (1990) J. Biol. Chem. 265, 7413-7418). In order to study the biological function of the acetyl-CoA hydrolase, a null mutation (achl-1) was created by gene replacement. The mutation, while not lethal, slows down acetate utilization. In comparison to wild-type, homozygote achl-l diploids, the onset of sporulation was delayed. When measuring the levels of ACH1 mRNA and acetyl-CoA hydrolase activity, we demonstrated that ACHl was highly expressed during sporulation process. These results indicated that acetyl-CoA hydrolase in yeast cells involved in acetate utilization and subsequently affected the sporulation process.

Model peptides reveal specificity of N alpha-acetyltransferase from Saccharomyces cerevisiae.

N alpha-Acetylation is a major co-translational modification occurring at the alpha-NH2 group of eukaryotic cytosolic proteins. In order to understand better the specificity of N alpha-acetyltransferase, we used the purified enzyme from yeast (Lee, F.-J. S., Lin, L.-W., and Smith J. A. (1988) J. Biol. Chem. 263, 14948-14955) and synthetic peptides mimicking the NH2 terminus of yeast and human proteins. Alcohol dehydrogenase I-(1-24) and 8 of the 19 synthetic analogues with substitutions at the NH2-terminal residue were N alpha-acetylated with varying efficiency. Penultimate amino acid substitutions, except for proline, had little influence on N alpha-acetylation. Substitution of sequences from N alpha-acetylated proteins into the yeast sequences which cannot be N alpha-acetylated demonstrated that not only the first 3 NH2-terminal residues but also more carboxyl-terminal residues were important for determining the specificity of N alpha-acetyltransferase. Two other peptides mimicking yeast mitochondrial cytochrome c oxidase (subunit VI) and ATPase inhibitor, which are naturally non-acetylated, were efficiently acetylated. In addition, recombinant human alcohol dehydrogenase I and basic fibroblast growth factor, which are naturally N alpha-acetylated, were not acetylated post-translationally.

A glucose-repressible gene encodes acetyl-CoA hydrolase from Saccharomyces cerevisiae.

Acetyl-CoA hydrolase, catalyzing the hydrolysis of acetyl-CoA, is presumably involved in regulating the intracellular acetyl-CoA pool. Recently, a yeast acetyl-CoA hydrolase was purified to homogeneity from Saccharomyces cerevisiae and partially characterized (Lee, F.-J. S., Lin, L.-W., and Smith, J. A. (1989) Eur. J. Biochem. 184, 21-28). In order to study the biological function and regulation of the acetyl-CoA hydrolase, we cloned and sequenced the full length cDNA encoding yeast acetyl-CoA hydrolase. RNA blot analysis indicates that acetyl-CoA hydrolase is encoded by a 2.5-kilobase mRNA. DNA blot analyses of genomic and chromosomal DNA reveal that the gene (so-called ACH1, acetyl-CoA hydrolase) is present as a single copy located on chromosome II. Acetyl-CoA hydrolase is established to be a mannose-containing glycoprotein, which binds concanavalin A. By measuring the levels of ACH1 mRNA and acetyl-CoA hydrolase activity in different growth phases and by examining the effects of various carbon sources, we have demonstrated that ACH1 expression is repressed by glucose.

Identification of methionine Nalpha-acetyltransferase from Saccharomyces cerevisiae.

N alpha-Acetylation is the most frequently occurring chemical modification of the alpha-NH2 group of eukaryotic proteins and was believed until now to be catalyzed by a single N alpha-acetyltransferase. The transfer of an acetyl group from acetyl coenzyme A to the alpha-amino group of five NH2-terminal residues (serine, alanine, methionine, glycine, and threonine) in proteins accounts for approximately 95% of acetylated residues. We have found that a crude lysate from Saccharomyces cerevisiae mutant (aaa1) deficient in N alpha-acetyltransferase activity can effectively transfer an acetyl group to peptides containing NH2-terminal methionine but not to serine or alanine. This methionine N alpha-acetyltransferase has been extensively purified, and this purified enzyme can selectively transfer an acetyl group to various model peptides containing an NH2-terminal methionine residue and a penultimate aspartyl, asparaginyl, or glutamyl residue. Such specificity of N alpha-acetylation of methionine has been previously observed based on the analysis of eukaryotic protein sequences (Persson, B., Flinta, C., Heijne, G., and Jornvall, H. (1985) Eur. J. Biochem. 152, 523-527; Arfin, S.M., and Bradshaw, R. A. (1988) Biochemistry 27, 7979-7984). The indentification of this methionine N alpha-acetyltransferase provides an explanation as to why two distinct classes of N alpha-acetylated proteins exist in nature: (i) those whose initiator methionine is acetylated and (ii) those whose penultimate residue is acetylated after cleavage of the initiator methionine.

N alpha acetylation is required for normal growth and mating of Saccharomyces cerevisiae.

Acetylation is the most frequently occurring chemical modification of the alpha-NH2 group of eucaryotic proteins and is catalyzed by N alpha-acetyltransferase. The yeast enzyme is encoded by the AAA1 (amino-terminal alpha-amino acetyltransferase) gene. A null mutation (aaa1-1) created by gene replacement, while not lethal, slows cell growth and results in heterogeneous colony morphology. In comparison with wild-type cells, aaa1-1/aaa1-1 diploids cannot enter stationary phase, are sporulation defective, and are sensitive to heat shock. In addition, the aaa1-1 mutation specifically reduces mating functions of MATa cells. These results indicate that N alpha acetylation plays a crucial role in yeast cell growth and mating.

N alpha-acetyltransferase deficiency alters protein synthesis in Saccharomyces cerevisiae.

Acetylation is the most frequently occurring chemical modification of the alpha-NH2 group of eukaryotic proteins and is catalyzed by a N alpha-acetyltransferase. Two-dimensional gel electrophoresis was used to compare the soluble proteins synthesized in wild type and a mutant (aaa1) yeast cells lacking N alpha-acetyltransferase. Among 855 soluble proteins identified in wild type and mutant, approximately 20% of the proteins in the mutant either disappeared or were shifted to higher pI without a change of molecular mass, and 27 proteins were observed only in the mutant. In addition, the synthesis of another 12% of the proteins in the mutant was either diminished or enhanced, suggesting that the acetylation of certain regulatory proteins may affect their expression. This is the first demonstration of the broad-based functional role of N alpha-acetylation in eukaryotic protein synthesis.