[Research progress on the relationship between dietary patterns and metabolic-associated fatty liver disease]

Globally, metabolic-asssociated fatty liver disease has become a significant health burden due to its complex pathogenesis, and there are no specific and effective therapeutic drugs to date. The onset and progression of metabolic-asssociated fatty liver disease is closely associated with improper dietary habits. The cornerstone to treat metabolic-asssociated fatty liver disease is weight loss through a well-balanced diet. This article summarizes and discusses the research progress at home and abroad in relationship to metabolic-asssociated fatty liver disease and dietary patterns such as the Mediterranean diet, the DASH diet, an energy-restricted balanced diet, a low fat diet, a low carbohydrate diet, a western diet, an animal food diet, a traditional diet, and others. In addition, it categorizes the effects of various dietary patterns on the prevention, treatment, or induction of several issues that need further metabolic-asssociated fatty liver disease research for subsequent reference.

Signal and noise extraction from analog memory elements for neuromorphic computing

Dense crossbar arrays of non-volatile memory (NVM) can potentially enable massively parallel and highly energy-efficient neuromorphic computing systems. The key requirements for the NVM elements are continuous (analog-like) conductance tuning capability and switching symmetry with acceptable noise levels. However, most NVM devices show non-linear and asymmetric switching behaviors. Such non-linear behaviors render separation of signal and noise extremely difficult with conventional characterization techniques. In this study, we establish a practical methodology based on Gaussian process regression to address this issue. The methodology is agnostic to switching mechanisms and applicable to various NVM devices. We show tradeoff between switching symmetry and signal-to-noise ratio for HfO₂-based resistive random access memory. Then, we characterize 1000 phase-change memory devices based on Ge₂Sb₂Te₅ and separate total variability into device-to-device variability and inherent randomness from individual devices. These results highlight the usefulness of our methodology to realize ideal NVM devices for neuromorphic computing.

Plasma growth hormone-binding protein levels in Atlantic salmon Salmo salar during smoltification and seawater transfer

Specific growth hormone (GH)-binding protein (Ghbp) was purified from Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss plasma with immunoprecipitation and characterized in cross-linking studies using autoradiography and western blots. The size of the Ghbp was estimated to be c. 53 kDa. A radioimmunoassay was established to measure Ghbp in salmonids, using antibodies specific against the extracellular segment of the S. salar growth hormone receptor 1 (grh1; GenBank AY462105). Plasma Ghbp levels were measured in S. salar smolts in fresh water and after transfer to seawater (SW; experiments 1 and 2), and in post-smolts kept at different salinities (0, 12, 22 and 34) for 3 months (experiment 3). A transient increase in plasma Ghbp, which lasted for 1 month or less, was noted in smolts after transfer to SW. Concomitantly, plasma GH and gill Na(+) -K(+) -ATPase activity increased during smoltification (in experiment 2). No difference in plasma Ghbp was evident between post-smolts kept at different salinities, although the fish kept at salinity 34 had higher plasma GH than the group kept at salinity 22 and higher hepatic ghr1 expression than post-smolts kept at salinity 12. This suggests that plasma Ghbp regulation may respond to salinity changes in the short term. The lack of correlation between Ghbp, plasma GH and hepatic ghr1 expression in the long-term post-smolt experiment indicates that Ghbp levels may be regulated independently of other components of the endocrine GH system in salmonids.

Differential effects of voltage-gated calcium channel blockers on calcium channel alpha-2-delta-1 subunit protein-mediated nociception

BACKGROUND

Overexpression of the voltage-gated calcium channel (VGCC) alpha-2-delta1 subunit protein (Cav α2 δ1 ) has been shown to cause pain states. However, whether VGCC are involved in pain states driven by abnormal Cav α2 δ1 expression is not known.

METHODS

Intrathecal injection of N-, P/Q- and L-type VGCC blockers were tested in two models: a transgenic neuronal Cav α2 δ1 overexpression (TG) model with behavioural hypersensitivity and a spinal nerve ligation (SNL) model with Cav α2 δ1 overexpression in sensory pathways and neuropathy pain states.

RESULTS

The nociceptive response to mechanical stimuli was significantly attenuated in both models with ω-conotoxin GVIA (an N-type VGCC blocker) and nifedipine (an L-type VGCC blocker), in which ω-conotoxin GVIA appeared more potent than nifedipine. Treatments with ω-agatoxin IVA (P-VGCC blocker), but not ω-conotoxin MVIIC (Q-VGCC blocker) had similar potency in the TG model as the N-type VGCC blocker, while both ω-agatoxin IVA and ω-conotoxin MVIIC had minimal effects in the SNL model compared with controls.

CONCLUSION

These findings suggest that, at the spinal level, N- and L-type VGCC are likely involved in behavioural hypersensitivity states driven by Cav α2 δ1 overexpression. Q-type VGCC has minimal effects in both models. The anti-nociceptive effects of P-type VGCC blocker in the Cav α2 δ1 TG mice, but minimally at the SNL model with presynaptic Cav α2 δ1 up-regulation, suggest that its potential action site(s) is at the post-synaptic and/or supraspinal level. These findings support that N-, L- and P/Q-type VGCC have differential contributions to behavioural hypersensitivity modulated by Cav α2 δ1 dysregulation at the spinal cord level.

Adenovirus-mediated anti-sense extracellular signal-regulated kinase 2 gene therapy inhibits activation of vascular smooth muscle cells and angiogenesis, and ameliorates transplant arteriosclerosis

The aim of this study was to explore underlying mechanisms of transplant arteriosclerosis (TA) based on intimal thickening that involve activation of vascular smooth muscle cells (VSMCs) and angiogenesis. We also examined the effects of adenovirus-mediated anti-sense extracellular signal-regulated kinase 2 (ERK2) (Adanti-ERK2) gene therapy on TA.

METHODS

We employed a rat aorta transplantation model (Brown-Norway → Lewis). The animals were divided into: (1) an isograft group (n = 6), (2) an empty control group (n = 6), (3) the Ad-LacZ group (n = 6), and (4) the adanti-ERK2 group (n = 6). At 60 days after transplantation, we documented the ratio of intima/(intima + media) the isografts pathologically. Staining for α-actin and platelet-derived growth factor (PDGF)-BB was performed to analyze the migration and secretion of VSMCs. We evaluated angiogenesis and COX-2 staining.

RESULT

Isografts showed normal histology; allografts from the empty control group and the Ad-LacZ group displayed typical TA lesions, while the pathology was significantly improved among the adanti-ERK2 group. The ratios of intima/(intima + media) were 7.6 ± 2.1%, 81.4% ± 6.7%, 85.9% ± 9.4%, and 15.9% ± 4.1% among the isograft group, the empty control, the Ad-LacZ, and the adanti-ERK2 groups respectively. The α-actin+ cells in the intima per field (×400) were 2.1 ± 1.1, 71.3 ± 9.2, 76.4 ± 11.3, and 34.8 ± 5.3, PDGF-BB+ cells, 0.9 ± 0.5, 28.4 ± 3.4, 29.1 ± 3.2, and 8.6 ± 1.7; COX-2+ cells in new capillaries were none, 36.3 ± 8.3, 40.9 ± 9.2, and 10.4 ± 3.9 respectively (P < .05).

CONCLUSION

Intimal thickening a key feature of TA, involves activation of VSMC (proliferation, migration and secretion), and the accompanying angiogenesis. Adanti-ERK2 gene therapy modulates the mechanisms, protecting allografts against TA.

The soluble tachyzoite antigen of Toxoplasma gondii has a protective effect on mouse allografts

BACKGROUND

Infection with some types of parasites can significantly prolong allograft survival in mice. It is unknown whether the soluble tachyzoite antigen (STAg) from Toxoplasma gondii has the same effect and by what mechanism it acts.

METHODS

A mouse model of cardiac and skin allograft transplantation was established between BALB/c (H-2(d)) and C57BL/6(H-2(b)) mice. T gondii STAg was prepared, and 5 μg was administered subcutaneously to recipient mice 4 days before transplantation. The graft status was checked daily, and histologic and immunohistochemical assays were used to evaluate rejection. The serum cytokine levels from the recipient mice were analyzed by Luminex.

RESULT

The administration of 5 μg STAg 4 days before transplantation significantly prolonged the survival time of the heart and skin allografts to 85.17 ± 14.06 and 24.17 ± 2.32 days, respectively. Immunohistochemical staining showed that the CD4(+) and CD8(+) T lymphocytes were markedly reduced in the allografts at day 7 posttransplantation. Notably, interleukin (IL)-12, IL-2, and IL-17 levels were significantly reduced in the serum of mice treated with STAg compared with untreated mice 7 days after transplantation. In contrast, the levels of the antiinflammatory cytokine IL-10 were elevated.

CONCLUSION

A single administration of STAg before transplantation can significantly prolong the allograft survival time, which is accompanied by impaired lymphocyte infiltration and a reduced Th1 response.

Antisense ERK1/2 oligodeoxynucleotide gene therapy attenuates graft arteriosclerosis of aortic transplant in a rat model

Chronic rejection is a major cause of transplant loss that is effected by the extracellular signal-regulated kinases (ERK) pathway. This study investigated the effects of antisense ERK1/2 oligodeoxynucleotide(ODN) gene therapy on chronic rejection.

METHODS

Lewis (RT1(1)) rats served as recipients of Brown-Norway (BN, RT1n) grafts. The BN rat abdominal aortas were harvested and orthotopically grafted into Lewis rats. The recipients were divided into three groups: (1) control group (n = 9), (2) random ODN transfer group (n = 10), and (3) antisense ODN transfer group (n = 10). At day 60 after transplantation, the recipients were sacrificed; the grafted aortas were evaluated histologically and immunohistochemically. ERK1/2 protein expression in the grafts was determined using Western Blot assays. Serum levels of slCAM-1 were detected by ELISA.

RESULTS

In the control group and random ODN transfer group, we observed a remarkable degree of intimal hyperplasia and inflammatory cell infiltration, including macrophages and T cells. Compared with the control group, antisense ERK1/2 ODN gene therapy resulted in a significant reduction in neointimal proliferation (P < .01), inhibition of ERK1/2 protein expression (P < .01), decreased graft infiltration with CD4+ T lymphocytes (P < .01), CD8+ T lymphocytes(P < .05), and ED-1 macrophages (P < .01) with decreased serum levels of sICAM-1 (P < .05). We obtained a negative correlation between ERK1/2 expression and immune cell infiltration or ICAM-1 level.

CONCLUSIONS

Antisense ERK1/2 gene therapy can attenuate graft arteriosclerosis so as to protect aortic allografts. The protection seemed to correlate with inhibition of inflammatory infiltration, implying that the ERK1/2 signal transduction pathway plays an important role in the process of chronic vascular rejection.

Adenovirus-Mediated Antisense-ERK2 Gene Therapy Attenuates Chronic Allograft Nephropathy

BACKGROUND

The aim of this study was to investigate the effects of adenovirus-mediated antisense ERK2 (Adanti-ERK2) gene therapy on chronic allograft nephropathy.

METHODS

We employed a rat kidney transplantation mode (F344-->Lewis) and studied four groups: (1) controls (n = 6); (2) vector controls (n = 6); (3) an Adanti-ERK2 group (n = 10); and (4) an isograft group (n = 4). The animals were monitored for proteinuria, graft histology, infiltrating cells, and immune-related gene (interleukin-2 [IL-2] and intracellular adhesion molecule-1 [ICAM-1]) expression for 20 weeks after transplantation.

RESULTS

The control group had increasing proteinuria during the 20-week follow-up. All rats showed advanced chronic renal failure associated with strong immune cell infiltration and immune gene expression. Chronic graft injury was accelerated in the vector-control group, but no significant difference was observed compared with the control group. In contrast, the Adanti-ERK2 group showed less inflammation and improved graft histology/function compared with controls. Moreover, ERK2 protein expression in the Adanti-ERK2 group was lower than in the control group (P < .05) and vector-control group (P < .05). Furthermore, serial estimates of genes (IL-2, ICAM-1) related to chronic rejection showed significant downregulation in the Adanti-ERK2 group (P < .01).

CONCLUSIONS

Adenovirus-mediated antisense ERK2 gene therapy attenuated chronic allograft nephropathy. The protective effects of antisense ERK2 gene therapy may have derived from a blocked ERK signal transduction pathway, which reduced ERK expression as well as those of immune-related genes.

Effects of local and systemic viral interleukin-10 gene transfer on corneal allograft survival

In this study, we explored the immunomodulatory effects of viral interleukin (IL) IL-10 after ex vivo and in vivo gene transfer in experimental corneal transplantation. Wistar-Furth rats were used as donors and major histocompatibility complex class I/II-disparate Lewis rats served as recipients. For ex vivo gene therapy donor corneas were either transfected with liposome/vIL-10 plasmid DNA mixtures or transduced with a vIL-10 expressing adenovirus vector (AdvIL-10). For in vivo studies, recipients were treated with AdvIL-10 intraperitoneally 1 day before transplantation. Graft survival was analysed using the Kaplan-Meier survival method. To monitor the efficacy of the therapy messenger RNA (mRNA) cytokine expression profiles in grafts and draining lymph nodes were analysed by quantitative real-time reverse transcription-polymerase chain reaction. Moreover, anti-adenovirus immunity was also investigated. Neither ex vivo liposome-mediated vIL-10 gene transfer nor ex vivo AdvIL-10 gene transfer led to prolonged corneal allograft survival. In contrast, corneal allograft survival was significantly prolonged in animals receiving systemic AdvIL-10 gene transfer. Moreover, only systemic vIL-10 gene therapy modulated the cytokine mRNA expression profile in draining lymph nodes. Interestingly, systemic AdvIL-10 gene transfer could not inhibit the generation of anti-adenovirus antibodies. Our data indicate systemic expression of the vIL-10 gene is required to modulate the cytokine expression profile in the draining lymph nodes, which might be a pre-requisite for the success of cytokine gene therapy.

Absence of GABA type A signaling in adult medial habenular neurons

Neural inhibition in the brain is mainly mediated by ionotropic GABA type A receptors. Apart from the GABA type A receptors, both K(+)-Cl(-) cotransporter isoform 2 and the GABA-synthesizing enzyme, glutamic acid decarboxylase, are essential determinants for GABA type A receptor-mediated inhibition. By using immunofluorescent staining, we observed that K(+)-Cl(-) cotransporter isoform 2, GABA type A receptor beta2/3 subunits and a presynaptically localized glutamic acid decarboxylase isoform, glutamic acid decarboxylase 65, were all absent in adult Sprague-Dawley rat medial habenular nucleus, while immunopositive staining for glutamic acid decarboxylase 67, GABA and GABA type B receptor type 2 subunit were present in the medial habenular nucleus. Consistent with the lack of GABA type A signaling as detected by immunohistochemistry, GABA (100 muM) evoked no measurable currents in the medial habenular nucleus but induced bicuculline-sensitive currents in the lateral habenular nucleus and in the CA1 area of hippocampus. We also failed to record miniature inhibitory postsynaptic currents in medial habenular nucleus neurons. These results support the idea that GABAergic transmission in medial habenular nucleus is probably not mediated by any of the most common GABA type A receptor subtypes. Our data suggest that GABA type B receptor-mediated inhibition may play a role in balancing neuronal excitation in this special region. Further exploration for factors determining medial habenular nucleus neural inhibition will lead to a more complete understanding of control of synaptic balance in the CNS.

Chromosome inheritance in triploid Pacific oyster Crassostrea gigas Thunberg

Reproduction and chromosome inheritance in triploid Pacific oyster (Crassostrea gigas Thunberg) were studied in diploid female x triploid male (DT) and reciprocal (TD) crosses. Relative fecundity of triploid females was 13.4% of normal diploids. Cumulative survival from fertilized eggs to spat stage was 0.007% for DT crosses and 0.314% for TD crosses. Chromosome number analysis was conducted on surviving progeny from DT and TD crosses at 1 and 4 years of age. At Year 1, oysters from DT crosses consisted of 15% diploids (2n=20) and 85% aneuploids. In contrast, oysters from TD crosses consisted of 57.2% diploids, 30.9% triploids (3n=30) and only 11.9% aneuploids, suggesting that triploid females produced more euploid gametes and viable progeny than triploid males. Viable aneuploid chromosome numbers included 2n+1, 2n+2, 2n+3, 3n-2 and 3n-1. There was little change over time in the overall frequency of diploids, triploids and aneuploids. Among aneuploids, oysters with 2n+3 and 3n-2 chromosomes were observed at Year 1, but absent at Year 4. Triploid progeny were significantly larger than diploids by 79% in whole body weight and 98% in meat weight at 4 years of age. Aneuploids were significantly smaller than normal diploids. This study suggests that triploid Pacific oyster is not completely sterile and cannot offer complete containment of cultured populations.

Cloning and characterization of the pseudonajatoxin b precursor

An Australian common brown snake, Pseudonaja textilis, is known to contain highly lethal neurotoxins. Among them, a long-chain alpha-neurotoxin, pseudonajatoxin b, has been identified. In this report, while presenting evidence for the presence of at least four such long-chain alpha-neurotoxins in the venom of P. textilis, we describe the characteristics of both the mRNA and the gene responsible for the synthesis of these neurotoxins. A precursor toxin synthesized from the gene has been identified as being capable of producing the isoforms possibly by post-translational modifications at its C-terminal end. Recombinant toxins corresponding to the precursor and its product have been found to possess similar binding affinities for muscular acetylcholine receptors (IC(50)=3x10(-8) M) and a lethality, LD(50), of 0.15 microg/g in mice.

Molecular cloning, characterization and evolution of the gene encoding a new group of short-chain alpha-neurotoxins in an Australian elapid, Pseudonaja textilis

The structure and organization of five genes responsible for the synthesis of six isoforms of short-chain alpha-neurotoxins in Pseudonaja textilis venom are reported in this paper. This also forms the first report which describes the synthesis of two neurotoxin mRNA variants from one of these genes (Pt-sntx1) as a result of alternative splicing. Each gene consists of three exons which are separated by two introns and each has a functional promoter. The promoter activity was confirmed by both CAT assay and Real-Time PCR. A transcription initiation site, two putative TATA boxes, one CCAAT box and the transcription factor binding consensus sites for AP-1, GATA-2, c/EBPb were identified in the 5' non-coding region of each gene. Phylogenetic analysis showed that these five genes from P. textilis constituted a distinct group which has evolved by gene duplication followed by accelerated evolution from an ancestral gene.

Postsynaptic short-chain neurotoxins from Pseudonaja textilis. cDNA cloning, expression and protein characterization

Two lethal proteins, which specifically bind to the nAChR from Torpedo californica, were isolated from the venom of Pseudonaja textilis, the common brown snake from Australia. The isolated proteins have masses of 6236 and 6345 Da and are structurally related to short-chain neurotoxins from other elapids. Six cDNAs encoding isoforms of related neurotoxins were cloned using the RT-PCR of the venom gland mRNAs. The sequences of the corresponding proteins consist of 57-58 amino acid residues and display several unique features when compared with all known short-chain neurotoxins. Accordingly, they grouped separately in phylogenetic analysis. The six cDNAs were expressed in Escherichia coli and the recombinant proteins were characterized. They have similar masses and display similar toxicities and binding constants to the nAChR as the native toxins isolated from the venom. Thus, a new group of short-chain postsynaptic neurotoxins from the venom of an Australian elapid has been characterized.

[Investigations on dermal contamination among workers exposed to terephthalic acid]

Forty-three workers exposed to terephthalic acid(TPA) were selected to study the dermal contamination of TPA and the load of TPA in urine. The results showed that there existed a double logarithmic correlation between dermal contamination of TPA and air TPA concentration and a a logarithmic correlation between urinary TPA and total inhaled TPA. Neither dermal TPA contamination nor total TPA exposure exhibited and dose-dependent relationship with urinary TPA. Based on this occupational epidemiology investigation, it was proved that the absorption of TPA is not mainly from dermal exposure.

[Enzyme-linked immunoadsorbent assays for myelin basic protein and antibodies to myelin basic protein in serum and CSF of patients with diseases of the nervous system]

Simplified enzyme-linked immunoadsorbent assays (ELISA) for myelin basic protein (MBP) and antibodies to myelin basic protein (Anti-MBP) have been used to test 337 patients with diseases of the nervous system including 36 compressive diseases (CMP), 33 multiple sclerosis (MS), 34 cerebrovascular diseases (CVD), 31 inflammatory diseases of central nervous system (ID), 161 epilepsy (EP) and 42 other nervous diseases (OND). Comparison of results among various groups indicates that serum mean MBP values of CMP, MS, CVD, ID and EP groups are significantly higher than those of OND group and normal control (P < 0.01). The serum mean MBP value of 33 acute trauma patients with spine fracture and paraplegia, the majority of CMP group, is the highest compared with MS group (P < 0.05), CVD, ID and EP groups (P < 0.01). CSF mean MBP value of 15 CVD patients is markedly greater than that of OND group (P < 0.05). No statistically significant differences are found in serum MBP values between OND group and normal control, and in serum and CSF Anti-MBP values among six groups by using our method.

MicroPACS: a PC-based small PACS implementation

To make picture archiving and communication systems (PACS) a practical reality for small-scale structures, it appears necessary to build a network that integrates and optimises production management, analysis and storage of images, and to include the ability to communicate with other similar remote structures. To solve the various technical problems related to small-scale PACS implementation, MicroPACS, a local area network, was developed around PC-like microcomputers. Every necessary function is assessed and implemented, including a centralised data-base, a distributed image bank, different storage levels and a specific task for image exchanges. An additional protocol was also developed for remote consultation through ISDN. Standardisation of image encapsulation and a point-to-point link between remote sites ensure easy transfers between heterogeneous local networks or bases and integrity of local databases.

Parameters of exponentially damped sinusoids in noise and their application to the analysis of visual evoked potentials

The backward prediction and singular value (SV) truncation methods for estimating multiple exponentially damped real sinusoids in noise have been studied. The basic theory and algorithm are outlined, and the effect on the error of computational parameters, such as the sampling window, the sampling rate, the order of the prediction-error filter (PEF) and the truncated point of SV, were studied using simulated data. If the computational parameters are carefully chosen, the estimate of frequency and damping factor of a damped sinusoid is quite accurate (within a certain range of signal to noise (S/N) ratio). We use this method to estimate the parameters of visual evoked potentials (VEP) and then reconstructed them from estimated parameters according to the resonant model. The error between original VEP and the reconstructed waveform is within 5%. This method can be used in the analysis and recognition of various systems.