A hierarchical combination algorithm for real-time cycle slip detection and repair in low satellite elevation and high ionospheric activity conditions

To enhance the accuracy and robustness of cycle slip detection and repair for triple-frequency data while minimizing the adverse effects of low satellite elevation and high ionospheric activity, a hierarchical combination algorithm for real-time cycle slip detection and repair is proposed. This algorithm begins by prioritizing the reduction of noise and ionospheric delay coefficients. It determines the optimal coefficients for the combination of observations from the BeiDou Navigation Satellite System's (BDS) Extra-Wide Lane (EWL), Wide Lane (WL), and Narrow Lane (NL). Leveraging the longer wavelength characteristics of the EWL combination, it simultaneously conducts cycle slip detection on the EWL combination alongside the pseudorange combination. Following this, based on the detection outcomes from the EWL combination, cycle slip detection is carried out on the WL combination. Finally, using the detection findings from the WL combination, cycle slip detection is executed on the NL combination. Given the NL combination's shorter wavelength and higher susceptibility to ionospheric delay, a dynamic ionospheric prediction model is applied to the NL combination to further mitigate the impact of ionospheric disturbances. After completing the cycle slip detection process, the results from the EWL, WL, and NL combinations are integrated and solved. Experimental results clearly demonstrate that, even in scenarios characterized by low satellite elevation and active ionospheric conditions, this algorithm consistently delivers outstanding detection performance for cycle slip instances, particularly for small cycle slip (less then two cycles). Remarkably, this performance is achieved without the need for intricate searches during cycle slip repair.

Application of a long short-term memory neural network algorithm fused with Kalman filter in UWB indoor positioning

Ultra-wideband technology has good anti-interference capabilities and development prospects in indoor positioning. Since ultra-wideband will be affected by random errors in indoor positioning, to exploit the advantages of the Kalman filter (KF) and the long short-term memory (LSTM) network, this paper proposes a long short-term memory neural network algorithm fused with the Kalman filter (KF-LSTM) to improve UWB positioning. First, the ultra-wideband data is processed through KF to weaken the noise in the data, and then the data is fed into the LSTM network for training, and the capability of the LSTM network to process time series features is employed to obtain more accurate label positions. Finally, simulation and measurement results show that the KF-LSTM algorithm achieves 71.31%, 37.28%, and 49.31% higher average positioning accuracy than the back propagation (BP) network, (back propagation network fused with the Kalman filter (KF-BP), and LSTM network algorithms, respectively, and the KF-LSTM algorithm performs more stably. Meanwhile, the more noise the data contains, the more obvious the stability contrast between the four algorithms.

Multi-orbit lunar GNSS constellation design with distant retrograde orbit and Halo orbit combination

The Moon is the closest natural satellite to mankind, with valuable resources on it, and is an important base station for mankind to enter deep space. How to establish a reasonable lunar Global Navigation Satellite System (GNSS) to provide real-time positioning, navigation, and timing (PNT) services for Moon exploration and development has become a hot topic for many international scholars. Based on the special spatial configuration characteristics of Libration point orbits (LPOs), the coverage capability of Halo orbits and Distant Retrograde Orbit (DRO) in LPOs is discussed and analyzed in detail. It is concluded that the Halo orbit with a period of 8 days has a better coverage effect on the lunar polar regions and the DRO has a more stable coverage effect on the lunar equatorial regions, and the multi-orbital lunar GNSS constellation with the optimized combination of DRO and Halo orbits is proposed by combining the advantages of both. This multi-orbital constellation can make up for the fact that a single type of orbit requires a larger number of satellites to fully cover the Moon, using a smaller number of satellites for the purpose of providing PNT services to the entire lunar surface. We designed simulation experiments to test whether the multi-orbital constellations meet the full lunar surface positioning requirements, and compare the coverage, positioning, and occultation effects of the four constellation designs that pass the test, and finally obtain a set of well-performing lunar GNSS constellations. The results indicate that the multi-orbital lunar GNSS constellation combining DRO and Halo orbits can cover 100% of the Moon surface, provides there are more than 4 visible satellites at any time on the Moon surface, which meets the navigation and positioning requirements, and the Position Dilution of Precision (PDOP) value is stable within 2.0, which can meet the demand for higher precision Moon surface navigation and positioning.

Improved GNSS integer ambiguity resolution method based on the column oriented Cholesky decomposition

Because the traditional Cholesky decomposition algorithm still has some problems such as computational complexity and scattered structure among matrices when solving the GNSS ambiguity,  it is the key problem to further improve the computational efficiency of the least squares ambiguity reduction correlation process in the carrier phase integer ambiguity solution. But the traditional matrix decomposition calculation is more complex and time-consuming, to improve the efficiency of the matrix decomposition, in this paper, the decomposition process of traditional matrix elements is divided into two steps: multiplication update and column reduction of square root calculation. The column reduction step is used to perform square root calculation and column division calculation, while the update step is used for the update task of multiplication. Based on the above ideas, the existing Cholesky decomposition algorithm is improved, and a column oriented Cholesky (C-Cholesky) algorithm is proposed to further improve the efficiency of matrix decomposition, so as to shorten the calculation time of integer ambiguity reduction correlation. The results show that this method is effective and superior, and can improve the data processing efficiency by about 12.34% on average without changing the integer ambiguity accuracy of the traditional Cholesky algorithm.

UWB Localization Based on Improved Robust Adaptive Cubature Kalman Filter

Aiming at the problems of Non-Line-of-Sight (NLOS) observation errors and inaccurate kinematic model in ultra-wideband (UWB) systems, this paper proposed an improved robust adaptive cubature Kalman filter (IRACKF). Robust and adaptive filtering can weaken the influence of observed outliers and kinematic model errors on filtering, respectively. However, their application conditions are different, and improper use may reduce positioning accuracy. Therefore, this paper designed a sliding window recognition scheme based on polynomial fitting, which can process the observation data in real-time to identify error types. Simulation and experimental results indicate that compared to the robust CKF, adaptive CKF, and robust adaptive CKF, the IRACKF algorithm reduces the position error by 38.0%, 45.1%, and 25.3%, respectively. The proposed IRACKF algorithm significantly improves the positioning accuracy and stability of the UWB system.

[Pituicytoma: a clinicopathological analysis of twenty-one cases]

Objective: To investigate the clinicopathological features and treatment strategies of pituicytoma. Methods: Twenty-one cases of pituicytoma were collected at the First Affiliated Hospital of Nanjing Medical University and Jinling Hospital, Nanjing, China from 2009 to 2020. The clinical data of 21 pituicytoma patients was retrospectively analyzed, and the relevant literature was reviewed. Results: Twenty-one patients aged 4 to 68 years, including 8 males and 13 females. All patients underwent surgical treatment. Histologically, the tumor was consisted almost entirely of elongate, bipolar spindle cells arranged in a fascicular or storiform pattern. Mitotic figures were rare. Immunohistochemically, tumor cells were diffusely positive for S-100 protein (21/21), vimentin (15/15) and TTF1 (14/14), while they were weakly or focally positive for GFAP (13/16) and EMA (6/12). CKpan was negative in all cases and Ki-67 proliferation index was low (<5%). Among the 18 patients with follow-up, all survived and 2 relapsed after surgery. Conclusions: Pituicytoma is a rare low-grade glioma of the sellar area. It is easily confused with other sellar tumors. Preoperative diagnosis is difficult. It needs to be confirmed by histopathology and immunohistochemistry. Microsurgery is the main treatment method at present.

A new transoral modality for the treatment of lingual thyroglossal duct cyst with suspension laryngoscopy by plasma coblation

INTRODUCTION

Lingual thyroglossal duct cysts (LTGDC) are a rare kind of thyroglossal duct cyst. However, Sistrunk surgery is not very suitable for this type of cyst. This study aimed to explore the efficacy of transoral excision of LTGDC by plasma coblation.

METHODS

The present study reviewed 11 patients, comprising seven males and four females, who had been diagnosed with LTGDC preoperatively by computed tomography (CT) and fibre-optic electronic laryngoscopy. Of those patients, two had recurrence after surgery of epiglottic cysts. All these patients underwent transoral excision by plasma coblation. Then, we collected preoperative data of the patients, observed the effect of surgery, and analysed factors relevant to LTGDC, including the estimated bleeding amount, postoperative hospitalisation, complications and recurrence rates.

RESULTS

The connection between LTGDC and hyoid was tapered on sagittal images of CT, which was vital evidence for the diagnosis of LTGDC. Surgery was performed successfully for all 11 patients, and all recovered without complication. There was no evidence of recurrence after surgery, during follow up for 3-43 months.

CONCLUSIONS

Transoral surgery for LTGDC can be performed successfully by plasma coblation, which is an effective and safe surgical treatment. Fibre-optic electronic laryngoscopy and CT are essential to the diagnosis of LTGDC in order to avoid missing detection and misdiagnosis.

Interleukin-4 Restores Insulin Sensitivity in Insulin-Resistant Osteoblasts by Increasing the Expression of Insulin Receptor Substrate 1

Obesity and latent inflammation can give rise to insulin resistance and type 2 diabetes. Here we established an insulin resistance model of osteoblasts to explore the restoration effect of anti-inflammatory interleukin-4 (IL-4) on insulin sensitivity and its mechanism. We found that IL-4 inhibited cell proliferation in a concentration- and time-dependent manner. Insulation resistance significantly reduced the phosphorylation levels of the insulin receptor substrate 1 (IRS1; Tyr612), Akt (Ser473), and AS160 (Ser318) proteins. The addition of IL-4 to the insulin resistance model led to a dose-dependent stimulation of the phosphorylation of IRS1, Akt, and AS160. IL-4 fully restored the activation of the insulin cascade in insulin-resistant cells at the concentration of 50 ng/ml. Additionally, IL-4 promoted the expression of IRS1 in a time-dependent manner. We conjecture that IL-4 restores insulin sensitivity in osteoblasts by upregulating the expression of IRS1. It was also found that IL-4 promoted the expression of osteoprotegerin depending on the time of exposure. This effect may play an important role in the regulation of the energy metabolism in the whole body.

Discovery of 4 exonic and 1 intergenic novel susceptibility loci for leprosy

Seven new risk coding variants have been identified through an exome-wide association study (EWAS), which studied the contributions of protein-coding variants to leprosy susceptibility. But some potential susceptibility loci were not studied in the previous EWAS study because of the project consideration. Seventeen unstudied potential susceptibility loci of the previous EWAS were validated in 3169 cases and 9814 controls in this study. Four disease-associated exonic loci were identified: rs671 in ALDH2 (P = 2.0 × 10^-20 , odds ratio [OR] = 1.35), rs13259978 in SLC7A2 (P = 1.74 × 10^-8 , OR = 1.28), rs925368 in GIT2 (P = 9.18 × 10^-17 , OR = 1.44), and rs75680863 in TCN2 (P = 8.37 × 10^-21 , OR = 0.74). Potentially implicating ZFP36L1 as a new susceptibility gene, 1 intergenic single nucleotide polymorphism (SNP), rs1465788 (P = 7.81 × 10^-6 , OR = 0.88), was also suggested to be associated with leprosy. A luciferase reporter assay showed that the rs1465788 risk allele notably decreased the transcription activity of the flanking sequence. These findings suggest the possible involvement of lipid metabolism, NF-κB homeostasis and macrophage antimicrobial pathways in leprosy pathogenesis.

Receptor-interacting Protein 140 represses Sirtuin 3 to facilitate hypertrophy, mitochondrial dysfunction and energy metabolic dysfunction in cardiomyocytes

AIM

The transcriptional cofactor receptor-interacting protein 140 (RIP140) is known as a deleterious regulator of cardiac mitochondrial function and energy metabolic homeostasis. This study revealed that RIP140 repressed Sirtuin 3 (SIRT3), a mitochondrial deacetylase that plays an important role in regulating cardiac function.

METHODS

RIP140 was overexpressed by adenovirus infection or was knocked down by RNA interference in neonatal rat cardiomyocytes.

RESULTS

RIP140 overexpression repressed, while RIP140 silencing elevated the expression and activity of SIRT3. Ad-RIP140 enhanced the expressions of the cardiac hypertrophic markers and increased cardiomyocyte surface area, whereas SIRT3 overexpression prevented the effect of Ad-RIP140. Additionally, SIRT3 overexpression reversed Ad-RIP140-induced mitochondrial dysfunction and energy metabolic dysfunction, such as increase in oxidative stress, decrease in mitochondrial membrane potential and ATP production, as well as downregulation of mitochondrial DNA-encoded genes and genes related to mitochondrial genome replication and transcription, mitochondrial oxidative phosphorylation and fatty acid oxidation. In contrast, SIRT3 silencing exacerbated RIP140-induced cardiomyocyte hypertrophy and mitochondrial dysfunction. Furthermore, the repression of SIRT3 by RIP140 was dependent on estrogen-related receptor-α (ERRα). The involvement of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) was ruled out of SIRT3 suppression by RIP140. RIP140 and PGC-1α might act as functional antagonists on the regulation of SIRT3.

CONCLUSION

This study indicates that suppression of SIRT3 by RIP140 facilitates the development of cardiomyocyte hypertrophy, mitochondrial dysfunction and energy metabolic dysfunction. Strategies targeting inhibition of RIP140 and upregulation of SIRT3 might improve cardiac energy metabolism and suggest therapeutic potential for heart diseases.

Conductive and protein resistant polypyrrole films for dexamethasone delivery

The development of inherently conducting polymers as controllable/programmable drug delivery systems has attracted significant interest in medical bionics, and the interfacial properties of the polymers, in particular, protein adsorption characteristics, is integral to the stability of the overall performance. Herein we report a hybrid conducting system based on polypyrrole doped with an anti-inflammatory prodrug, dexamethasone phosphate (DexP), upon which post-surface modification was conducted to render the polymer more biostable. We firstly investigated the influence of the current density and DexP concentration on the physiochemical properties and surface characteristics of the resulting polymer films. Films were then surface modified with thiolated poly(ethylene glycol). The influence of surface modification on inhibition of nonspecific protein adsorption to the polymer surfaces was evaluated using electrochemistry and quartz crystal microbalance. Furthermore, studies were undertaken to examine the effect of surface coatings on the drug release behaviour triggered by electrical stimulation. Our results demonstrated that both the physiochemical and interfacial properties of conducting polymers can be modulated to enhance the performance of the materials as biocompatible drug delivery systems. This provides important insight into molecular engineering of conducting polymers to facilitate their applications in medical bionics.

Gene expression of the p16(INK4a)-Rb and p19(Arf)-p53-p21(Cip/Waf1) signaling pathways in the regulation of hematopoietic stem cell aging by ginsenoside Rg1

The elucidation of the molecular mechanisms underlying the effects of traditional Chinese medicines in clinical practice is a key step toward their worldwide application, and this topic is currently a subject of intense research interest. Rg1, a component of ginsenoside, has recently been shown to perform several pharmacological functions; however, the underlying mechanisms of these effects remain unclear. In the present study, we investigated whether Rg1 has an anti-senescence effect on hematopoietic stem cells (HSCs) and the possible molecular mechanisms driving any effects. The results showed that Rg1 could effectively delay tert-butyl hydroperoxide (t-BHP)-induced senescence and inhibit gene expression in the p16(INK4a)-Rb and p19(Arf)-p53-p21(Cip/Waf1) signaling pathways in HSCs. Our study suggested that these two signaling pathways might be potential targets for elucidating the molecular mechanisms of the Rg1 anti-senescence effect.

WAVE3 promotes epithelial-mesenchymal transition of gastric cancer through upregulation of Snail

WAVE3, an actin cytoskeleton remodeling protein overexpressed in many kinds of cancers, has been associated with a lot of metastatic diseases. However, the role and mechanisms of the high expression of WAVE3 in human gastric cancer has not been fully elucidated. Here we demonstrated that WAVE3 was expressed in all six kinds of gastric-cancer cell lines: BGC-823, SGC-7901, AGS, MGC803, MKN28 and MKN45. Furthermore, a correlation was found between aggressiveness of these cell lines and expression of WAVE3. Next, we investigated the role of WAVE3 in SGC-7901 cells and found that upregulating WAVE3 could promote the migration, invasion and proliferation of SGC-7901 cells in vitro. It has been reported that WAVE3 could induce cancer invasion and metastasis by participating epithelial-mesenchymal transition (EMT). However, the mechanisms are not entirely clear. In this study we showed that elevated WAVE3 levels could induce EMT in SGC-7901 cells by dampening the expression of E-cadherin while increasing the expression of vimentin. Elevated WAVE3 levels could also improve the expression of transcription factor Snail. In addition, downregulating Snail could particularly reduce EMT and the metastasis, invasion and proliferation activity in SGC-7901 cells elevated by overexpression of WAVE3. Taken together, we demonstrated that WAVE3 promoted gastric-cancer-cells migration and invasion by taking part in EMT via upregulation of Snail. WAVE3 could be a useful target for gastric-cancer prevention and therapy.

Effects of a proteasome inhibitor on the NF-κB signalling pathway in experimental osteoarthritis

OBJECTIVES

To evaluate the effects of the proteasome inhibitor MG-132 on the expression of nuclear factor (NF)-κB p65, inhibitor (I)-κB, tumour necrosis factor (TNF)-α, and interleukin (IL)-1β in the cartilage and synovial tissues of rats with osteoarthritis (OA), and to investigate the role that the ubiquitin/proteasome system (UPS) plays in the OA process.

METHOD

A total of 144 adult male Sprague Dawley rats were randomly assigned to four groups: anterior cruciate ligament transaction (ACLT) + MG-132 (ACLT/M), ACLT + dimethylsulfoxide (ACLT/D), sham surgery (Sham), and naïve + MG-132 (naïve/M). Pathological morphology was undertaken. mRNA expression levels of NF-κB p65, I-κB, TNF-α, and IL-1β were determined using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The activities of the 20S proteasome chymotrypsin-like and peptidylglutamyl-peptide hydrolase-like enzymes were measured using fluorospectrophotometry.

RESULTS

The Mankin scores at all time points in ACLT/M rats were significantly lower than those in ACLT/D rats (p < 0.05). Despite the NF-κB p65 in the synovial tissue at 2 weeks after surgery and IL-1β in the cartilage tissue at 12 weeks after surgery, mRNA expression levels of NF-κB p65, IL-1β, and TNF-α at other time points in ACLT/M were significantly lower than those in ACLT/D (p < 0.05). mRNA levels of I-κB in the cartilage tissue in ACLT/M were significantly higher than those in ACLT/D at 2 weeks after surgery (p < 0.05). mRNA levels of I-κB in the synovial tissue in ACLT/M were higher than those in ACLT/D at all time points, and the difference was significant at 4 weeks after surgery (p < 0.05). MG-132 decreased the activities of the 20S proteasome chymotrypsin-like and peptidylglutamyl-peptide hydrolase-like enzymes in the cartilage and synovial tissues of rats.

CONCLUSIONS

The proteasome inhibitor MG-132 delays the progress of OA by alleviating synovial inflammation and protecting the articular cartilage tissue.

Effects of transportation on expression of Hsp90, Hsp70, Hsp27 and αB-crystallin in the pig stomach

Twenty pigs were randomly divided into four groups based on the amount of time spent in transport (zero, one, two or four hours). Pathological examination of all transported pigs showed that exfoliation of chief cells from the gastric surface occurred in pigs during transportation. These results imply that integrity of the gastric mucosa was compromised by damage occurring during the four-hour transportation, despite the fact that gastric ulcers were not present. Levels of Hsp90 expression in stomach tissues were significantly decreased (P<0.01) after two-hour transportation, but Hsp70 levels increased significantly (P<0.05) after one, two and four hours of transportation. Hsp27 levels remained relatively stable independent of the length of transport. Levels of αB-crystallin expression in the stomach were significantly increased (P<0.05) after four hours of transportation. Variations in Hsp90, Hsp70, Hsp27 and αB-crystallin levels suggest that distinct protective functions are modulated by different Hsps in stomach tissues during transportation. Alterations in Hsp70 and αB-crystallin expression appear to be associated with protective functions, as no apparent gastric ulcers were present in pigs that underwent four hours of transportation. Levels of heat shock transcription factor-1, which regulate the expression of Hsps, remained relatively stable independent of the transportation period.

The n-terminal 5-MER peptide analogue P165 of amyloid precursor protein exerts protective effects on SH-SY5Y cells and rat hippocampus neuronal synapses

The disturbance of the insulin-signaling pathway plays an important role in Alzheimer's disease. Resistance to insulin signaling renders neurons energy-deficient and vulnerable to oxidization or other metabolic insults and impairs synaptic plasticity. In search of neuroprotective drugs, we synthesized a peptide analogue, P165, an active domain of the soluble amyloid precursor protein, which is resistant to degradation and is suitable for oral administration in a clinical setting. Initially, we confirmed that P165 can protect cells from streptozotocin-caused damage and stimulate cell outgrowth using cultured SH-SY5Y cell lines treated with streptozotocin. P165 significantly reduced lactate dehydrogenase leakage from damaged cells, thereby rescuing cell energy production. Insulin signaling such as insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) proteins were upregulated to stimulate cell survival and growth. We proceeded to investigate the effect of P165 on streptozotocin-treated Alzheimer's disease (AD) rats. The data showed that P165 protected synaptic loss and dysfunction by increasing synaptophysin and PSD-95 (post synaptic density-95), while simultaneously decreasing α-synuclein expression. Moreover, animal behavior testing clearly showed that P165 increased rats' learning and memory activity. Overall, these results constitute evidence that peptide analogue 165 may protect synapse and improve learning and memory ability in AD.

Evidence for a role of mast cells in the mucosal injury induced by Newcastle disease virus

We have previously demonstrated that mast cells were significantly increased during Newcastle disease virus (NDV) infection, but their precise role in the process is unknown. In this study, we investigated the role of mast cells in this process by using ketotifen, a mast cell membrane stabilizer. A total of 60 specific-pathogen-free chickens were randomly divided into 3 groups of 20 birds each (NDV-infected group, ketotifen-pretreated group, and the control group). The ketotifen-pretreated group was administered orally with ketotifen before NDV infection. On 12, 24, and 48 h postinfection, 5 chickens from each treatment were killed. Tissues of proventriculus were collected to quantify mast cells, the content of tryptase and histamine by cytochemistry, immunohistochemistry, and fluorescence analysis, respectively. The results showed that the population of mast cells and the content of tryptase and histamine were increased significantly in the proventriculus (P < 0.01) of infected birds compared with the control group. An acute mucosal injury was observed in the infected chickens. In contrast, among chickens pretreated with ketotifen, followed by NDV infection, the mast cells number and the content of tryptase and histamine were decreased significantly (P < 0.01). Likely as a result, the mucosal injury was remitted remarkably. The overall results of this experiment suggest that mast cells are implicated in NDV-induced mucosal injury. Inhibition of mast cell mediator release may represent a novel strategy to modulate this process.

Effects of pig antibacterial peptides on growth performance and intestine mucosal immune of broiler chickens

Currently, substitutions for antibiotic growth promoters in animals are attracting interest. This study investigated the effects of pig antibacterial peptides (PABP) on growth performance and small intestine mucosal immune responses in broilers. Three hundred 1-d-old Arbor Acre male broiler chickens were randomly allocated to 5 groups with 60 birds per group. The groups were control group; PABP administered in drinking water at 20 and 30 mg/L of water; or PABP supplemented in feed at 150 and 200 mg/kg of diet. The birds were fed a corn-soybean based diet for 6 wk. Chickens were weighed weekly and killed after 42 d of feeding, and growth performance was measured. Samples of the duodenum and jejunum were collected. The villus height, mucosa thickness, alkaline phosphatase activity, and numbers of secreting IgA and goblet cells were evaluated. The PABP-treated groups had greater BW and average daily gain, greater height of villus and thickness of gut mucosa, greater activity of alkaline phosphatase, higher ratio of secreting IgA, and a greater number of goblet cells compared with the control group (P<0.05). In conclusion, PABP can improve the growth performance, increase the intestinal ability to absorb nutrients, and improve the mucosal immunity of the intestine.

BAC-mediated transgenic expression of fluorescent autophagic protein Beclin 1 reveals a role for Beclin 1 in lymphocyte development

Beclin 1/Atg6 is an essential component of the evolutionary conserved PtdIns(3)-kinase (Vps34) protein complex that regulates macroautophagy (autophagy) in eukaryotic cells and also interacts with antiapoptotic Bcl-2 family members, Bcl-2, and Bcl-x(L). To elucidate the physiological function of Beclin 1, we generated transgenic mice producing a green fluorescent Beclin 1 protein (Beclin 1-GFP) under Beclin 1 endogenous regulation. The beclin 1-GFP transgene is functional because it completely rescues early embryonic lethality in beclin 1-deficient mice. The transgenic mice appear normal, with undetected change in basal autophagy levels in different tissues, despite the additional expression of functional Beclin 1-GFP. Staining of Beclin 1-GFP shows mostly diffuse cytoplasmic distribution in various tissues. Detailed analysis of the transgene expression by flow cytometry reveals a Bcl-2-like biphasic expression pattern in developing T and B cells, as well as differential regulation of expression in mature versus immature thymocytes following in vitro stimulation. Moreover, thymocytes expressing high Beclin 1-GFP levels appear increasingly sensitive to glucocorticoid-induced apoptosis in vitro. Our results, therefore, support a role for Beclin 1 in lymphocyte development involving cross talk between autophagy and apoptosis.

Bacterium organizes hierarchical amorphous structure in microbial cellulose

A pellicle, a gel film of microbial cellulose, is a supermolecular system containing 99% of water by weight, which is closely related to an amorphous structure in it. Using ultra-small-angle neutron scattering, in order to cover over a wide range of length scales from nm to 10 microm, we examined the hierarchical amorphous structure in the microbial cellulose, which is synthesized by a bacterium (Acetobacter xylinum). The microbial cellulose swollen by water shows small-angle scattering that obeys a power law q -behavior according to q -alpha as a function of the magnitude of the scattering vector q . The power law, determined by scattering, is attributed to a mass fractal due to the distribution of the center of mass for the crystallite (microfibril) in amorphous cellulose swollen by water. As q increases, alpha takes the values of 2.5, 1, and 2.35, corresponding, respectively, to a gel network composed of bundles, a bundle composed of cellulose ribbons, and concentration fluctuations in a bundle. From the mass fractal q -behavior and its length scale limits, we evaluated a volume fraction of crystallite in microbial cellulose. It was found that 90% of the cellulose bundle is occupied by amorphous cellulose containing water.

Serum tumour markers in patients with chronic kidney disease

OBJECTIVE. Tumour markers are widely used for monitoring cancer patients and for screening certain tumours. It has recently been shown that the concentrations of some tumour markers are higher in patients with chronic kidney disease (CKD) than in healthy subjects. We analysed the influence of renal function and hemodialysis treatment on the serum levels of CA19-9, CA125, alpha fetoprotein (AFP), CA15.3, CA72.4, CYFRA 21-1, neuron-specific enolase (NSE) and squamous cell carcinoma antigen (SCC-Ag).

MATERIAL AND METHODS

232 non-dialysis patients with CKD and 37 uraemic patients treated with maintenance hemodialysis were enrolled in this study. The nondialysis patients were divided into three groups depending on their creatinine clearance (Ccr) levels: group 1 = Ccr < or =25 mL/min; group 2 = 25.1-49.9 mL/min; group 3 = Ccr > or =50 mL/min. For comparison, we chose 37 non-dialysis patients with similar Ccr, age and same gender as controls.

RESULTS

The serum concentrations of CA19-9, CA125 (male), CYFRA 21-1, NSE and SCC-Ag correlated negatively with Ccr, while there were no significant differences in the concentrations of CA125 (female), AFP, CA15.3, CA72.4. The serum levels of CA19-9, CA125, AFP, CA15.3, CA72.4, CYFRA 21-1, NSE and SCC-Ag showed no differences between hemodialysis patients and non-dialysis controls (p > 0.017).

CONCLUSIONS

The increase in the serum levels of CA19-9, CA125 (in males), CYFRA 21-1, NSE and SCC-Ag in patients with CKD affects the specificity of these markers in the diagnosis of cancer. Hemodialysis does not affect the serum levels of CA19-9, CA125, AFP, CA15.3, CA72.4, CYFRA 21-1, NSE and SCC-Ag.

Vibration training: benefits and risks

The main results of our recent several studies, i.e. the measurements of vibration training results for single case and group studies as well as the cardiovascular parameter measurements during vibrations and the corresponding hydrodynamic analysis, are summarized. Our studies and previous work all confirm that vibration training is an effective training method in order to improve maximal strength and flexibility as well as various other factors if the training is properly designed. Some recommendations regarding the proper ranges of frequencies, amplitudes and exposure duration of vibration training are made based on the existing vibration training practice and mechanism analysis, although much work remains to be carried out in order to set up clear rules for various groups of people so that maximal training results could be expected and in the meantime potential dangerous effects could be avoided. Cardiovascular parameter measurements confirm that total peripheral resistance (TPR) to the blood flow is increased during body vibration. Hydrodynamic analysis offers the mechanism for the increase of TPR through the deformation of vessels. As a reaction of compensation, more capillaries are probably opened in order to keep a necessary level of cardiac output needed for the body, resulting in more efficient gas and material metabolism between the blood and muscle fibres. This might be one of the reasons for the various potential beneficial effects of vibration training.

The early-onset phenotype of mitochondrial trifunctional protein deficiency: a lethal disorder with multiple tissue involvement

Mitochondrial trifunctional protein (TFP) deficiency is a clinically heterogeneous disorder with phenotypes of different severity. Early onset, severe forms predominantly exhibit cardiomyopathy, life-threatening arrhythmias and liver dysfunction; the later-onset, milder phenotype is mainly characterized by neuromyopathic features. The mechanisms that determine these heterogeneous presentations are unknown. We performed multiple tissue immunoblots from a patient with early-onset, lethal TFP deficiency and demonstrated absent TFP antigen in all. The predominant cardiac manifestation of severe TFP deficiency reflects its essential role in myocardial energetics, not its tissue-specific expression.

Deletion of the N-terminus of murine map2 by gene targeting disrupts hippocampal ca1 neuron architecture and alters contextual memory

Microtubule-associated protein-2 (MAP2) is a brain specific A-kinase anchoring protein that targets the cyclic AMP-dependent protein kinase holoenzyme (PKA) to microtubules. Phosphorylation of MAP2 by different protein kinases is crucial for neuronal growth. The N-terminus of MAP2 contains the binding site for regulatory subunit II of cAMP-dependent protein kinase (PKA-RIIbeta). Using homologous recombination, we created a mutant line of mice (delta1-158) that express truncated MAP2 lacking the N-terminal peptide and the PKA binding site. Deletion of the PKA binding site from the MAP2 gene resulted in decreased efficiency of MAP2 phosphorylation. Biochemical and immunohistochemical studies demonstrate major changes in the morphology of hippocampal neurons in delta1-158 mice. Behavioral tests indicate that delta1-158 mice were impaired (exhibited less conditioned freezing) relative to Wild-Type (WT) controls during a test of contextual, but not during auditory cue, fear conditioning when tested at 8 weeks or 8 months of age. The delta1-158 mice displayed a heightened sensitivity to shock at 8 weeks, but not at 8 months of age. We conclude that PKA binding to MAP2 and MAP2 phosphorylation is essential for the selective development of contextual memory.

Morphological relationship between intercalated duct and pancreatic islet in streptozotocin and/or camostat mesilate administrations in the chicken

Present electron microscopical and immunocytochemistrical studies elucidated some morphological relationship between intercalated duct (ICD) and pancreatic islet cells in the chicken in streptozotocin (STZ) and/or camostat mesilate (CM) administrations. Twenty-one chickens were set into four experimental groups: (1) control group, (2) STZ administration group, (3) CM administration group, and (4) STZ + CM administration group. Cytoplasms of ICD cells stained more strongly with eosin in STZ administration group than other groups, and electron-dense materials and intercalated processes between ICD and islet cells were also increasing in time dependence in STZ administration. Number of pancreatic islet in STZ + CM co-administration was about 3.1 times larger than other groups. Many small sized cells were detected at surrounding area of ICD and they incorporated 5-bromo-2'-deoxyuridine better than other experimental groups. Present morphological data suggested that ICD cells might support some tolerances of pancreatic endocrine cells against toxic substances and also involve in regeneration of new pancreatic islet cells in STZ + CM co-administration.

A model analysis of internal loads, energetics, and effects of wobbling mass during the whole-body vibration

The internal loads, energetics, and the effects of wobbling mass during the whole-body vibration are studied in terms of analysis and comparison of two models: one is a system of four degrees-of-freedom with rigid and wobbling masses in both lower body and upper body (Model A), while the other one (Model B) is a system of three degrees-of-freedom with a rigid upper body and is otherwise identical to Model A. The main findings are the following: (1) The wobbling mass in the upper body is able to reduce the total internal load on the rigid mass of the upper body considerably. (2) "Partial" internal loads on a certain part of the body may be even larger than the total load on the same part of the body because of the phase differences among the partial loads. Therefore, a full consideration of safety during the whole-body vibration has to take not only the total, but also all the partial internal loads into account. (3) The fluctuation of power input and the fluctuation of mechanical energy could be much larger than the fluctuation of dissipation rate. (4) For frequencies higher than the resonance frequency range, the amplitude of the oscillation of the centre of mass of the body is so reduced that only the change of elastic potential energy dominates in the change of mechanical energy. Thus, a simple picture of energy flow is obtained as follows: for approximately one half of the oscillation period, the energy flows from the vibrator into the human body and is mainly stored in the muscle-tendon system, while for the remaining approximate half of the period, the energy flows from the muscle-tendon system back to the vibrator with a slightly smaller amount because a small part of the flown-in energy has been dissipated.

Removal of chemical contaminants from water to below USEPA MCL using fiber glass supported activated carbon filters

A new, low-cost fiber glass supported activated carbon (FGAC) filter has been prepared that displays enhanced adsorption characteristics for the removal of BTEX (benzene, toluene, ethylbenzene, and p-xylene) from water to below maximum contaminant level (MCL) regulated by USEPA and two chemical warfare agent simulants (diisopropylmethyl phosphonate and 2-chloroethyl ethyl sulfide) to barely detectable levels. Breakthrough curves for both the FGAC filter and a commercially available granular activated carbon (GAC) filter containing equal weights of adsorbent show that the FGAC filter has greatly improved kinetics of adsorption over the GAC filter for all six chemical contaminants. Benzene breakthrough curves showed the FGAC filter effluent to contain less than one ppb as compared to several parts per million in the GAC filter effluent. This was 2 orders of magnitude better than the GAC and represents a major advance in generating good water quality for the military as well as the general public. The FGAC filter showed a much lower pressure drop and could be completely regenerated at least 6 times by heating to 190 degrees C under vacuum.

[Measurement of chlorodifluoromethane(HCFC-22) in the atmosphere by using an O2-induced electron capture detector (ECD)]

Chlorodifluoromethane (CHClF2, HCFC-22), a typical substitute of dichlorodifluoromethane(CF2Cl2, CFC-12), which atmospheric concentration was only at 10(-12) V/V level. After preconcentrated air sample, O2-Induced method was used to enhance sensitivity of ECD response to HCFC-22. When O2 concentration in carrier gas was 0.54%, there was the greatest value of S/N(signal to noise) and ECD response increased by about 500 times. With the study of other conditions, such as selection of the ECD temperature, programing of the column oven temperature and carrier gas flow, a practicable analysis method with high sensitivity of ECD was established.

Dynamic interactions of behavior and amine neurochemistry in acquisition and maintenance of social rank in crayfish

This review summarizes a set of experimental approaches with which we explore fighting behavior in crayfish and the importance of aminergic systems in its control. Our results illustrate that agonistic behavior in crustaceans can be characterized within a quantitative framework, that different types of behavioral plasticity in aggressive behavior are in need of physiological explanation, and that pharmacological intervention involving serotonergic systems produces characteristic changes in fighting. Moreover, we attempt to identify changes in neurochemistry during the acquisition of social status. Many of the studies presented here summarize ongoing work. Nonetheless, results to date complement and extend previous detailed physiological, morphological and biochemical studies exploring the roles of amines in aggression.

[Oxidative DNA damage of cartilage in osteoarthrosis]

In order to study molecular mechanism of osteoarthrosis, we used molecular techniques to detect DNA oxidative damage of cartilage. There were 10 samples from clinical operation including 5 cases of replacement of hip joint, 4 degenerative cartilage of knee osteoarthrosis, and 1 free body of knee joint. DNA from all samples was run out on an agarose gel and appeared classic nucleosomal ladders. (8-hydroxyl-2'-deoxyguanosine)/ml (8-OHdG) in DNA samples was measured by high-performance liquid chromatography with electrochemical detection (HPLC-EC). The results showed that the levels of 8-OHdG were increased to 0.11-0.26 ng.ml-1, average 0.177 ng.ml-1. Normal controls were lower than 0.05 ng.ml-1. The high 8-OHdG in DNA led to a misreading of affected templates and base-pair exchange, which could be a sensitive indicator about oxidative DNA damage, which was produced by free radicals or other DNA damage agents. The result suggests that oxidative DNA damage may be the molecular mechanism of osteoarthrosis.

[The action of proglumide blocking gastrin on gastric cancer cells]

OBJECTIVE

To investigate the practicability of proglumide to treat gastric cancer.

METHODS

MKN45 gastric cancer cell line was cultured and the effects on gastrin and gastrin receptor antagonist proglumide proliferative rate, cell dynamic cycle distribution and the concentration of cAMP in the cells were observed in vitro.

RESULTS

Gastrin promoted the proliferation of MKN45 cells and shifted cells from phase G(0)/G(1) to phase S, G(2)/M as well as increased intracellular cAMP, while proglumide blocked these effects.

CONCLUSIONS

Gastrin induces the proliferation and synthesis of DNA by its receptor. Proglumide may provide a new approach of non-cytotoxic treatment of gastric cancer.

Mammalian capping enzyme binds RNA and uses protein tyrosine phosphatase mechanism

Mammalian capping enzymes are bifunctional proteins with both RNA 5'-triphosphatase and guanylyltransferase activities. The N-terminal 237-aa triphosphatase domain contains (I/V)HCXXGXXR(S/T)G, a sequence corresponding to the conserved active-site motif in protein tyrosine phosphatases (PTPs). Analysis of point mutants of mouse RNA 5'-triphosphatase identified the motif Cys and Arg residues and an upstream Asp as required for activity. Like PTPs, this enzyme was inhibited by iodoacetate and VO43- and independent of Mg2+, providing additional evidence for phosphate removal from RNA 5' ends by a PTP-like mechanism. The full-length, 597-aa mouse capping enzyme and the C-terminal guanylyltransferase fragment (residues 211-597), unlike the triphosphatase domain, bound poly (U) and were nuclear in transfected cells. RNA binding was increased by GTP, and a guanylylation-defective, active-site mutant was not affected. Ala substitution at positions required for the formation of the enzyme-GMP capping intermediate (R315, R530, K533, or N537) also eliminated poly (U) binding, while proteins with conservative substitutions at these sites retained binding but not guanylyltransferase activity. These results demonstrate that the guanylyltransferase domain of mammalian capping enzyme specifies nuclear localization and RNA binding. Association of capping enzyme with nascent transcripts may act in synergy with RNA polymerase II binding to ensure 5' cap formation.