Crystalline Ropes of Metallic Carbon Nanotubes

Fullerene single-wall nanotubes (SWNTs) were produced in yields of more than 70 percent by condensation of a laser-vaporized carbon-nickel-cobalt mixture at 1200degreesC. X-ray diffraction and electron microscopy showed that these SWNTs are nearly uniform in diameter and that they self-organize into "ropes," which consist of 100 to 500 SWNTs in a two-dimensional triangular lattice with a lattice constant of 17 angstroms. The x-ray form factor is consistent with that of uniformly charged cylinders 13.8 +/- 0.2 angstroms in diameter. The ropes were metallic, with a single-rope resistivity of <10(-4) ohm-centimeters at 300 kelvin. The uniformity of SWNT diameter is attributed to the efficient annealing of an initial fullerene tubelet kept open by a few metal atoms; the optimum diameter is determined by competition between the strain energy of curvature of the graphene sheet and the dangling-bond energy of the open edge, where growth occurs. These factors strongly favor the metallic (10,10) tube with C5v symmetry and an open edge stabilized by triple bonds.

Analysis of the mouse transcriptome based on functional annotation of 60,770 full-length cDNAs

Only a small proportion of the mouse genome is transcribed into mature messenger RNA transcripts. There is an international collaborative effort to identify all full-length mRNA transcripts from the mouse, and to ensure that each is represented in a physical collection of clones. Here we report the manual annotation of 60,770 full-length mouse complementary DNA sequences. These are clustered into 33,409 'transcriptional units', contributing 90.1% of a newly established mouse transcriptome database. Of these transcriptional units, 4,258 are new protein-coding and 11,665 are new non-coding messages, indicating that non-coding RNA is a major component of the transcriptome. 41% of all transcriptional units showed evidence of alternative splicing. In protein-coding transcripts, 79% of splice variations altered the protein product. Whole-transcriptome analyses resulted in the identification of 2,431 sense-antisense pairs. The present work, completely supported by physical clones, provides the most comprehensive survey of a mammalian transcriptome so far, and is a valuable resource for functional genomics.

Biomedical applications of collagen

Collagen is regarded as one of the most useful biomaterials. The excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenecity, made collagen the primary resource in medical applications. The main applications of collagen as drug delivery systems are collagen shields in ophthalmology, sponges for burns/wounds, mini-pellets and tablets for protein delivery, gel formulation in combination with liposomes for sustained drug delivery, as controlling material for transdermal delivery, and nanoparticles for gene delivery and basic matrices for cell culture systems. It was also used for tissue engineering including skin replacement, bone substitutes, and artificial blood vessels and valves. This article reviews biomedical applications of collagen including the collagen film, which we have developed as a matrix system for evaluation of tissue calcification and for the embedding of a single cell suspension for tumorigenic study. The advantages and disadvantages of each system are also discussed.

Hepatocyte nuclear factor 4alpha (nuclear receptor 2A1) is essential for maintenance of hepatic gene expression and lipid homeostasis

The numerous functions of the liver are controlled primarily at the transcriptional level by the concerted actions of a limited number of hepatocyte-enriched transcription factors (hepatocyte nuclear factor 1alpha [HNF1alpha], -1beta, -3alpha, -3beta, -3gamma, -4alpha, and -6 and members of the c/ebp family). Of these, only HNF4alpha (nuclear receptor 2A1) and HNF1alpha appear to be correlated with the differentiated phenotype of cultured hepatoma cells. HNF1alpha-null mice are viable, indicating that this factor is not an absolute requirement for the formation of an active hepatic parenchyma. In contrast, HNF4alpha-null mice die during embryogenesis. Moreover, recent in vitro experiments using tetraploid aggregation suggest that HNF4alpha is indispensable for hepatocyte differentiation. However, the function of HNF4alpha in the maintenance of hepatocyte differentiation and function is less well understood. To address the function of HNF4alpha in the mature hepatocyte, a conditional gene knockout was produced using the Cre-loxP system. Mice lacking hepatic HNF4alpha expression accumulated lipid in the liver and exhibited greatly reduced serum cholesterol and triglyceride levels and increased serum bile acid concentrations. The observed phenotypes may be explained by (i) a selective disruption of very-low-density lipoprotein secretion due to decreased expression of genes encoding apolipoprotein B and microsomal triglyceride transfer protein, (ii) an increase in hepatic cholesterol uptake due to increased expression of the major high-density lipoprotein receptor, scavenger receptor BI, and (iii) a decrease in bile acid uptake to the liver due to down-regulation of the major basolateral bile acid transporters sodium taurocholate cotransporter protein and organic anion transporter protein 1. These data indicate that HNF4alpha is central to the maintenance of hepatocyte differentiation and is a major in vivo regulator of genes involved in the control of lipid homeostasis.

A candidate precursor to serous carcinoma that originates in the distal fallopian tube

The tubal fimbria is a common site of origin for early (tubal intraepithelial carcinoma or TIC) serous carcinomas in women with familial BRCA1 or 2 mutations (BRCA+). Somatic p53 tumour suppressor gene mutations in these tumours suggest a pathogenesis involving DNA damage, p53 mutation, and progressive loss of cell cycle control. We recently identified foci of strong p53 immunostaining-termed 'p53 signatures'-in benign tubal mucosa from BRCA+ women. To examine the relationship between p53 signatures and TIC, we compared location (fimbria vs ampulla), cell type (ciliated vs secretory), evidence of DNA damage, and p53 mutation status between the two entities. p53 signatures were equally common in non-neoplastic tubes from BRCA+ women and controls, but more frequently present (53%) and multifocal (67%) in fallopian tubes also containing TIC. Like prior studies of TIC, p53 signatures predominated in the fimbriae (80-100%) and targeted secretory cells (HMFG2 + /p73-), with evidence of DNA damage by co-localization of gamma-H2AX. Laser-capture microdissected and polymerase chain reaction-amplified DNA revealed reproducible p53 mutations in eight of 14 fully-analysed p53 signatures and all of the 12 TICs; TICs and their associated ovarian carcinomas shared identical mutations. In one case, a contiguous p53 signature and TIC shared the same mutation. Morphological intermediates between the two, with p53 mutations and moderate proliferative activity, were also seen. This is the first report of an early and distinct alteration in non-neoplastic upper genital tract mucosa that fulfils many requirements for a precursor to pelvic serous cancer. The p53 signature and its malignant counterpart (TIC) underline the significance of the fimbria, both as a candidate site for serous carcinogenesis and as a target for future research on the early detection and prevention of this disease.

Beta-cell lipotoxicity in the pathogenesis of non-insulin-dependent diabetes mellitus of obese rats: impairment in adipocyte-beta-cell relationships

Hyperinsulinemia, loss of glucose-stimulated insulin secretion (GSIS), and peripheral insulin resistance coexist in non-insulin-dependent diabetes mellitus (NIDDM). Because free fatty acids (FFA) can induce these same abnormalities, we studied their role in the pathogenesis of the NIDDM of obese Zucker diabetic fatty (ZDF-drt) rats from 5 weeks of age (before the onset of hyperglycemia) until 14 weeks. Two weeks prior to hyperglycemia, plasma FFA began to rise progressively, averaging 1.9 +/- 0.06 mM at the onset of hyperglycemia (P < 0.001 vs. controls). At this time GSIS was absent and beta-cell GLUT-2 glucose transporter was decreased. The triacylglycerol content of prediabetic islets rose to 10 times that of controls and was correlated with plasma FFA (r = 0.825; P < 0.001), which, in turn, was correlated with the plasma glucose concentration (r = 0.873; P < 0.001). Reduction of hyperlipacidemia to 1.3 +/- 0.07 mM by pair feeding with lean littermates reduced all beta-cell abnormalities and prevented hyperglycemia. Normal rat islets that had been cultured for 7 days in medium containing 2 mM FFA exhibited increased basal insulin secretion at 3 mM glucose, and first-phase GSIS was reduced by 68%; in prediabetic islets, first-phase GSIS was reduced by 69% by FFA. The results suggest a role for hyperlipacidemia in the pathogenesis of NIDDM; resistance to insulin-mediated antilipolysis is invoked to explain the high FFA despite hyperinsulinemia, and sensitivity of beta cells to hyperlipacedemia is invoked to explain the FFA-induced loss of GSIS.

Direct antidiabetic effect of leptin through triglyceride depletion of tissues

Leptin is currently believed to control body composition largely, if not entirely, via hypothalamic receptors that regulate food intake and thermogenesis. Here we demonstrate direct extraneural effects of leptin to deplete fat content of both adipocytes and nonadipocytes to levels far below those of pairfed controls. In cultured pancreatic islets, leptin lowered triglyceride (TG) content by preventing TG formation from free fatty acids (FFA) and by increasing FFA oxidation. In vivo hyperleptinemia, induced in normal rats by adenovirus gene transfer, depleted TG content in liver, skeletal muscle, and pancreas without increasing plasma FFA or ketones, suggesting intracellular oxidation. In islets of obese Zucker Diabetic Fatty rats with leptin receptor mutations, leptin had no effect in vivo or in vitro. The TG content was approximately 20 times normal, and esterification capacity was increased 3- to 4-fold. Thus, in rats with normal leptin receptors but not in Zucker Diabetic Fatty rats, nonadipocytes and adipocytes esterify FFA, store them as TG, and later oxidize them intracellularly via an "indirect pathway" of intracellular fatty acid metabolism controlled by leptin. By maintaining insulin sensitivity and preventing islet lipotoxicity, this activity of leptin may prevent adipogenic diabetes.

Jasmonic acid carboxyl methyltransferase: a key enzyme for jasmonate-regulated plant responses

Methyl jasmonate is a plant volatile that acts as an important cellular regulator mediating diverse developmental processes and defense responses. We have cloned the novel gene JMT encoding an S-adenosyl-l-methionine:jasmonic acid carboxyl methyltransferase (JMT) from Arabidopsis thaliana. Recombinant JMT protein expressed in Escherichia coli catalyzed the formation of methyl jasmonate from jasmonic acid with K(m) value of 38.5 microM. JMT RNA was not detected in young seedlings but was detected in rosettes, cauline leaves, and developing flowers. In addition, expression of the gene was induced both locally and systemically by wounding or methyl jasmonate treatment. This result suggests that JMT can perceive and respond to local and systemic signals generated by external stimuli, and that the signals may include methyl jasmonate itself. Transgenic Arabidopsis overexpressing JMT had a 3-fold elevated level of endogenous methyl jasmonate without altering jasmonic acid content. The transgenic plants exhibited constitutive expression of jasmonate-responsive genes, including VSP and PDF1.2. Furthermore, the transgenic plants showed enhanced level of resistance against the virulent fungus Botrytis cinerea. Thus, our data suggest that the jasmonic acid carboxyl methyltransferase is a key enzyme for jasmonate-regulated plant responses. Activation of JMT expression leads to production of methyl jasmonate that could act as an intracellular regulator, a diffusible intercellular signal transducer, and an airborne signal mediating intra- and interplant communications.

Human myocyte-specific enhancer factor 2 comprises a group of tissue-restricted MADS box transcription factors

The MEF2 site is an essential element of muscle enhancers and promoters that is bound by a nuclear activity found, so far, only in muscle and required for tissue-specific transcription. We have cloned a group of transcription factors from human muscle that are responsible for this activity: They are present in muscle-specific DNA-binding complexes, have a target sequence specificity identical to that of the endogenous activity, and are MEF2 site-dependent transcriptional activators. These MEF2 proteins comprise several alternatively spliced isoforms from one gene and a related factor encoded by a second gene. All share a conserved amino-terminal DNA-binding domain that includes the MADS homology. MEF2 transcripts are ubiquitous but accumulate preferentially in skeletal muscle, heart, and brain. Specific alternatively spliced isoforms are restricted to these tissues, correlating exactly with the presence of endogenous MEF2 activity. Furthermore, MEF2 protein is detected only in skeletal and cardiac muscle nuclei and not in myoblast and nonmuscle cells. Thus, post-transcriptional regulation is important in the generation of tissue-specific MEF2 activity. Cardiac and smooth, as well as skeletal, muscles contain functionally saturating levels of MEF2 trans-activating factors that are absent in nonmuscle cells. Moreover, MEF2 is induced in nonmuscle cells by MyoD; however, MEF2 alone is insufficient to produce the full muscle phenotype. Implications for the molecular mechanisms of myogenesis are considered.

Distribution of calcitonin gene-related peptide in the rat peripheral nervous system with reference to its coexistence with substance P

This immunocytochemical study, using a double-staining method, showed that calcitonin gene-related peptide-like immunoreactive structures are widely distributed in the peripheral nervous system and that many of them coexist with substance P-like immunoreactive structures in single sensory ganglion cells. Neurons positive for calcitonin gene-related peptide but negative for substance P were detected in sensory ganglia. These cells were large (about 30-45 micron in diameter); these primary sensory neurons containing calcitonin gene-related peptide can probably act independently of substance P. There were neurons containing calcitonin gene-related peptide without substance P in the pterygopalatine ganglion, although these cells were less numerous than in the sensory ganglia. In consecutive sections, calcitonin gene-related peptide-like structures occurred in thyroid parafollicular cells, which also contain calcitonin. This suggested that messenger RNA for producing calcitonin gene-related peptide is also present in the thyroid, and like calcitonin, calcitonin gene-related peptide may have a peripheral physiological role.

Abnormally short serum half-lives of IgG in beta 2-microglobulin-deficient mice

The MHC class I-related receptor, FcRn, mediates the transfer of maternal gamma globulin (IgG) to young rodents, primarily via intestinal transcytosis, and this provides humoral immunity for the first few weeks after birth. In a previous study, the site of mouse IgG1 (mIgG1) with which FcRn interacts has been mapped using recombinant wild-type and mutated Fc-hinge fragments. The site encompasses residues at the CH2-CH3 domain interface of Fc (Ile253, His310, Gln311, His433 and Asn434) and the same amino acids are involved in regulating the pharmacokinetics of the Fc-hinge fragments. This suggests that in addition to its known function, FcRn might also play a role in IgG homeostasis. Consistent with this hypothesis, in this study, we demonstrate that FcRn alpha-chain mRNA is present not only in neonatal brush border but also in other tissues of adult animals (liver, lung, spleen and endothelial cells). In addition, analysis of the pharmacokinetics of mouse Ig/Fc-hinge fragments in genetically manipulated mice that are deficient in the expression of FcRn demonstrates that the beta-phase half-lives are abnormally short. These findings suggest that FcRn is involved in IgG homeostasis.

Coexistence of calcitonin gene-related peptide and substance P-like peptide in single cells of the trigeminal ganglion of the rat: immunohistochemical analysis

The localization of calcitonin gene-related peptide (CGRP) and substance P (SP) in the rat trigeminal ganglion was examined by means of the indirect immunofluorescent method. About 40% of neurons in the ganglion contained CGRP-like immunoreactivity (CGRPI), while about 20% of neurons showed SP-like immunoreactivity (SPI). In serial sections, nearly all the SPI neurons contained CGRPI.

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.

Stimuli-responsive liposomes for drug delivery

The ultimate goal of drug delivery is to increase the bioavailability and reduce the toxic side effects of the active pharmaceutical ingredient (API) by releasing them at a specific site of action. In the case of antitumor therapy, association of the therapeutic agent with a carrier system can minimize damage to healthy, nontarget tissues, while limit systemic release and promoting long circulation to enhance uptake at the cancerous site due to the enhanced permeation and retention effect (EPR). Stimuli-responsive systems have become a promising way to deliver and release payloads in a site-selective manner. Potential carrier systems have been derived from a wide variety of materials, including inorganic nanoparticles, lipids, and polymers that have been imbued with stimuli-sensitive properties to accomplish triggered release based on an environmental cue. The unique features in the tumor microenvironment can serve as an endogenous stimulus (pH, redox potential, or unique enzymatic activity) or the locus of an applied external stimulus (heat or light) to trigger the controlled release of API. In liposomal carrier systems triggered release is generally based on the principle of membrane destabilization from local defects within bilayer membranes to effect release of liposome-entrapped drugs. This review focuses on the literature appearing between November 2008-February 2016 that reports new developments in stimuli-sensitive liposomal drug delivery strategies using pH change, enzyme transformation, redox reactions, and photochemical mechanisms of activation. WIREs Nanomed Nanobiotechnol 2017, 9:e1450. doi: 10.1002/wnan.1450 For further resources related to this article, please visit the WIREs website.

Induction by leptin of uncoupling protein-2 and enzymes of fatty acid oxidation

We have studied mechanisms by which leptin overexpression, which reduces body weight via anorexic and thermogenic actions, induces triglyceride depletion in adipocytes and nonadipocytes. Here we show that leptin alters in pancreatic islets the mRNA of the genes encoding enzymes of free fatty acid metabolism and uncoupling protein-2 (UCP-2). In animals infused with a recombinant adenovirus containing the leptin cDNA, the levels of mRNAs encoding enzymes of mitochondrial and peroxisomal oxidation rose 2- to 3-fold, whereas mRNA encoding an enzyme of esterification declined in islets from hyperleptinemic rats. Islet UCP-2 mRNA rose 6-fold. All in vivo changes occurred in vitro in normal islets cultured with recombinant leptin, indicating direct extraneural effects. Leptin overexpression increased UCP-2 mRNA by more than 10-fold in epididymal, retroperitoneal, and subcutaneous fat tissue of normal, but not of leptin-receptor-defective obese rats. By directly regulating the expression of enzymes of free fatty acid metabolism and of UCP-2, leptin controls intracellular triglyceride content of certain nonadipocytes, as well as adipocytes.

The predictive value of self assessed general, physical, and mental health on functional decline and mortality in older adults

OBJECTIVE

To examine the extent to which older people's self assessments of general health, physical health, and mental health predict functional decline and mortality.

DESIGN

The study uses population-based secondary data from the US Longitudinal Study of Aging (LSOA).

PARTICIPANTS

A total of 7527 persons aged 70 years or above living in the community.

METHODS

Eight different measures on self reported general, physical, and mental health were used. Change in functional status was measured using a composite index of ADLs and IADLs over a period of six years. Duration of survival was calculated over a period of seven years. Adjusting for age and gender, multiple logistic regression was used in analysing functional decline, and Cox proportional hazard model, for mortality. Then all of the self assessed health measures were incorporated into the final model--controlling for baseline sociodemographic characteristics, functional status, disease/conditions, and use of health and social services--to assess the independent contribution of each measure in predicting future health outcomes.

MAIN RESULTS

Overall, older people's self assessed general, physical, and mental health were predictive of functional decline and mortality. In multivariate analyses, older people who assessed their global health, self care ability, and physical activity less favourably were more likely to experience poor health outcomes. Gender disparity, however, was observed with poor global health affecting functional decline in men only. Self care ability was predictive of functioning in women only, whereas it was predictive of mortality in men only.

CONCLUSIONS

Self assessed global health, as well as, specific dimensions of health act as significant, independent predictors of functioning and mortality in a community dwelling older people.

Synergistic enhancement of nuclear receptor function by p160 coactivators and two coactivators with protein methyltransferase activities

Nuclear receptors (NRs) activate gene transcription by binding to specific enhancer elements and recruiting coactivators of the p160 family to promoters of target genes. The p160 coactivators in turn enhance transcription by recruiting secondary coactivators, including histone acetyltransferases such as CREB-binding protein (CBP) and p300/CBP-associated factor (p/CAF), as well as the recently identified protein methyltransferase, coactivator-associated arginine methyltransferase 1 (CARM1). In the current study, protein arginine methyltransferase 1 (PRMT1), another arginine-specific protein methyltransferase that shares a region of high homology with CARM1, was also found to act as a coactivator for NRs. PRMT1, like CARM1, bound to the C-terminal AD2 activation domain of p160 coactivators and thereby enhanced the activity of NRs in transient transfection assays. The shape of the graphs of reporter gene activity versus the amounts of CARM1 or PRMT1 expression vector indicated a cooperative relationship between coactivator concentration and activity. Moreover, CARM1 and PRMT1 acted in a synergistic manner to enhance reporter gene activation by both hormone-dependent and orphan NRs. The synergy was most evident at low levels of transfected NR expression vectors, where activation of reporter genes was almost completely dependent on the presence of NR and all three exogenously supplied coactivators, i.e. GRIP1, CARM1, and PRMT1. In contrast, with the higher levels of NR expression vectors typically used in transient transfection assays, NR activity was much less dependent on the combination of coactivators, suggesting that target gene activation occurs by different mechanisms at high versus low cellular concentrations of NR. Because multiple coactivators are presumably required to mediate transcriptional activation of native genes in vivo, the low-NR conditions may provide a more physiologically relevant assay for coactivator function.

Skin thickness of Korean adults

Skin thickness varies considerably between different races and age-groups, between men and women, and between different regions of the body surface. A few authors reported the skin thickness of different regions of the body, but no detailed study have been performed on Asian. We performed 452 biopsies on 28 different regions of the normal skin of Korean men and women. The specimens were stained with hematoxylin-eosin and measured microscopically. The thickness of the skin (epidermis plus dermis) ranged from 521 to 1977 microm; the eyelid, prepuce, and inguinal skin was thinnest (521-626 microm), and the back was thickest (1977 microm). The thickness of the epidermis varied from 31 to 637 microm; skin thickness in the prepuce, eyelid, supraclavicular region, postauricular region, and axilla ranged from 31 to 71 microm; the buttock, dorsum of the hand, and dorsum of the foot were relatively thick (138-189 microm); the palm and sole were thickest (601-637 microm). The thickness dermis varied from 469 to 1942 microm; skin thickness in the eyelid, prepuce, inguinal region, and postauricular region ranged from 469 to 645 microm; the buttock, chest, and anterior neck were relatively thick (1318-1586 microm); the back was thickest (1942 microm). The epidermis accounted for 3.7-16.8% of the entire skin in most regions, except in the palm and sole (40.6-44.6%). Thickness data may be useful in harvesting full- or split-thickness skin grafts.

Suppression of hepatitis B virus expression and replication by hepatitis C virus core protein in HuH-7 cells

Hepatitis B and C viruses (HBV and HCV, respectively) are associated with acute and chronic liver diseases and hepatocellular carcinoma. To elucidate the molecular status of superinfection with these two hepatitis viruses, we cotransfected the full-length or truncated version of HCV structural genes (core and envelope 1) together with the cloned HBV DNA into a human hepatoma cell line (HuH-7). Expression of HBV-specific major transcripts (3.5 and 2.1 kb), as well as HBV antigens (hepatitis B surface antigen and hepatitis B e and core antigens), was reduced about two- to fourfold by the presence of the HCV structural genes. In addition, the secretion of HBV viral particles, including the viral nucleocapsid and mature virion, was drastically suppressed about 20-fold. Analysis of the intracellular HBV core protein-associated nucleic acid indicated that the encapsidated HBV pregenomic RNA was similarly reduced about 14-fold. Deletion analysis of the HCV structural genes demonstrated that the core gene alone or the fragment containing the core protein's N-terminal 122 amino acid residues conferred the same level of suppressive activity as the full-length structural genes. By indirect immunofluorescence, we found that the core protein of HCV was located in the cytoplasm of transfected HuH-7 cells at day 3 posttransfection and was targeted to the nucleus at day 6. Thus, the kinetics of the suppressive effect exerted by HCV constructs matched the timing of core protein entrance into the nucleus. Our results substantiate the clinical finding that HBV markers are suppressed by superinfection with HCV and further imply that this inhibitory effect may occur in the processes of transcription and encapsidation of HBV pregenomic RNA and may be mediated by the core protein of HCV. The deduced amino acid sequence of the HCV core protein has revealed that it is a basic protein which contains a putative DNA-binding motif (SPRG), as well as triplicate nuclear localization signals and several putative protein kinase A and C recognition sites. These characteristics imply that the HCV core protein can also function as a gene-regulatory protein.

The PTPN22 C1858T functional polymorphism and autoimmune diseases--a meta-analysis

OBJECTIVE

To assess whether combined evidence shows the association between the protein tyrosine phosphatase non-receptor 22 (PTPN22) C1858T polymorphism and autoimmune diseases, and to summarize the effect size of the polymorphism associated with susceptibility of autoimmune diseases.

METHODS

We surveyed studies on the PTPN22 C1858T polymorphism and autoimmune diseases using comprehensive Medline search and review of the references. Meta-analysis was performed for genotypes T/T (recessive effect), T/T + C/T (dominant effect) and T-allele in random effects models.

RESULTS

Twenty-nine studies with 43 comparisons including 13 rheumatoid arthritis (RA), six systemic lupus erythematosus (SLE), six type-1 DM (T1D), three Grave's disease (GD), four inflammatory bowel diseases (IBD), three juvenile idiopathic arthritis (JIA), two psoriasis, two multiple sclerosis, two Addison's disease and two Celiac disease were available for the meta-analysis. The overall odds ratios (ORS) for T-allele, T/T and T/T + C/T genotypes were significantly increased in RA, SLE, GD and T1D (OR for T-allele = 1.58, 1.49, 1.85, 1.61, respectively, P < 0.00001). This meta-analysis showed the association between the T-allele and the T/T genotype and JIA (OR = 1.34, P = 0.03; OR = 1.97, P = 0.02) but did not reveal the association between the PTPN22 C1858T polymorphism and IBD, psoriasis, multiple sclerosis, Addison's disease and Celiac disease.

CONCLUSION

This meta-analysis demonstrates that the PTPN22 1858T allele confers susceptibility to RA, SLE, GD, T1D and JIA, supporting evidence of association of the PTPN22 gene with subgroup of autoimmune diseases.

Novel form of lipolysis induced by leptin

Hyperleptinemia causes disappearance of body fat without a rise in free fatty acids (FFA) or ketones, suggesting that leptin can deplete adipocytes of fat without releasing FFA. To test this, we measured FFA and glycerol released from adipocytes obtained from normal lean Zucker diabetic fatty rats (+/+) and incubated for 0, 3, 6, or 24 h in either 20 ng/ml recombinant leptin or 100 nM norepinephrine (NE). Whereas NE increased both FFA and glycerol release from adipocytes of +/+ rats, leptin increased glycerol release in +/+ adipocytes without a parallel increase in FFA release. In adipocytes of obese Zucker diabetic fatty rats (fa/fa) with defective leptin receptors, NE increased both FFA and glycerol release, but leptin had no effect on either. Leptin significantly lowered the mRNA of leptin and fatty acid synthase of adipocytes (FAS) (p < 0.05), and up-regulated the mRNA of peroxisome proliferator-activated receptor (PPAR)-alpha, carnitine palmitoyl transferase-1, (CPT-1), and acyl CoA oxidase (ACO) (p < 0.05). NE (100 nM) also lowered leptin mRNA (p < 0.05) but did not affect FAS, PPARalpha, ACO, or CPT-1 expression. We conclude that in normal adipocytes leptin directly decreases FAS expression, increases PPARalpha and the enzymes of FFA oxidation, and stimulates a novel form of lipolysis in which glycerol is released without a proportional release of FFA.

Congestion of right liver graft in living donor liver transplantation

BACKGROUND

Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. One solution to this problem is to use a right liver graft without a middle hepatic vein (MHV). However, the need for drainage from the MHV tributaries has not yet been described.

METHODS

Five right liver grafts without a MHV were transplanted in patients including two hepatitis B virus-cirrhosis, two fulminant hepatic failure and one secondary biliary cirrhosis. The graft weight ranged from 650 to 1,000 g, corresponding to 48 to 83% of the standard liver volume of the recipients.

RESULTS

Two of five recipients were complicated with severe congestion of the right median sector immediately after reperfusion, followed by prolonged massive ascites and severe liver dysfunction. One of the patients died of sepsis with progressive hepatic dysfunction 20 days after the operation.

CONCLUSIONS

Preservation and reconstruction of the MHV tributaries is recommended to prevent congestion of the right liver graft without MHV.

Disappearance of body fat in normal rats induced by adenovirus-mediated leptin gene therapy

Sustained hyperleptinemia of 8 ng/ml was induced for 28 days in normal Wistar rats by infusing a recombinant adenovirus containing the rat leptin cDNA (AdCMV-leptin). Hyperleptinemic rats exhibited a 30-50% reduction in food intake and gained only 22 g over the experimental period versus 115-132 g in control animals that received saline infusions or a recombinant virus containing the beta-galactosidase gene (AdCMV-beta Gal). Body fat was absent in hyperleptinemic rats, whereas control rats pair-fed to the hyperleptinemic rats retained approximately 50% body fat. Further, plasma triglycerides and insulin levels were significantly lower in hyperleptinemic versus pair-fed controls, while fatty acid and glucose levels were similar in the two groups, suggestive of enhanced insulin sensitivity in the hyperleptinemic animals. Thus, despite equivalent reductions in food intake and weight gain in hyperleptinemic and pair-fed animals, identifiable fat tissue was completely ablated only in the former group, raising the possibility of a specific lipoatrophic activity for leptin.

Role of nitric oxide in obesity-induced beta cell disease

Here we report that free fatty acid-induced suppression of insulin output in prediabetic Zucker diabetic fatty (ZDF) rats is mediated by NO. When normal islets were cultured in 2 mM FFA, NO production and basal insulin secretion increased slightly. In cultured prediabetic ZDF islets, FFA induced a fourfold greater rise in NO, upregulated mRNA of inducible nitric oxide synthase (iNOS), and reduced insulin output; both nicotinamide and aminoguanidine, which lower NO, prevented the FFA-mediated increase in iNOS mRNA, reduced NO, and minimized the loss of insulin secretion. In vivo nicotinamide or aminoguanidine treatment of prediabetic ZDF rats prevented the iNOS expression in islets and decreased beta cell dysfunction while blocking beta cell destruction and hyperglycemia. We conclude that NO-lowering agents prevent adipogenic diabetes in obese rats.