Identification of critical TF-miRNA-mRNA regulation loops for colorectal cancer metastasis

To explore the potential cause of colorectal cancer metastasis, gene expression profiles, GSE21510, and miRNA expression profiles, GSE48074, were downloaded from the Gene Expression Omnibus database. Differentially expressed genes in metastatic colorectal and non metastatic colorectal cancer compared with the normal samples were identified via the limma package in R. The differentially expressed miRNAs in colorectal cancer samples with lymph node metastasis compared with those without lymph node metastasis were screened out by the some method. Differentially expressed genes that were upregulated in colorectal cancer samples with distant metastasis in comparison to that in samples without distant metastasis and normal samples were considered to play important roles in colorectal cancer metastasis. Functional enrichment analysis of these genes was conducted using the Database for Annotation, Visualization, and Integrated Discovery v6.7. Biological processes related to cell differentiation and cell proliferation were significantly enriched. TF (transcription factor)-miRNA-mRNA regulation loops were constructed by using the starBase and ChIPBase databases. Finally, six critical regulation loops were screened out. They were composed of two TFs, two miRNAs, and three mRNAs. Some of these TFs, mRNAs, or miRNAs have previously been identified as critical targets in colorectal cancer metastasis. Additionally, several new targets were identified in our study, which may be helpful to improve metastatic colorectal cancer treatment.

Morphological characteristics and developmental changes of the ovary in the tick Haemaphysalis longicornis Neumann

Haemaphysalis longicornis (Ixodida: Ixodidae) is an important vector of transovarially transmitted parasites of the genus Babesia (Piroplasmida: Babesiidae). In the present study, we investigated the morphological characteristics and developmental changes of the ovary of H. longicornis. We show that the ovary of H. longicornis has a single tubular structure and is surrounded by a tunica propria. There is a longitudinal groove along one side of the ovary. During feeding and after engorgement, great changes can be observed in the ovary of H. longicornis and two rapid growth phases can be detected. The number of major protein bands of the ovary is significantly increased from day 3 of feeding and reaches a maximum on the day of engorgement. Therefore, the great diversity of proteins in the ovaries of H. longicornis can facilitate the identification of new targets for vaccine development.

Protective effect of oleanolic acid against beta cell dysfunction and mitochondrial apoptosis: crucial role of ERK-NRF2 signaling pathway

Pancreatic beta cell dysfunction is a hallmark of diabetes. Our previous results have shown that oleanolic acid (OA) has anti-diabetic potential. However, there is little literature reporting the effect of OA on beta cell dysfunction. The present study was designed to investigate the protective effect of OA against lipotoxicity and the underlying mechanisms. Lepr (db/db) diabetic mice were subjected to fasting blood glucose measurement, intraperitoneal glucose tolerance test after the administration of OA for two weeks. Histopathological observation was conducted by HE staining and transmission electron microscopy assay. Pancreatic islets were isolated from db/db diabetic mice and C57BL/6J mice. Palmitic acid (PA) was used to induce lipotoxicity in vitro. Apoptosis was evaluated in pancreatic islets in diabetic mice and in isolated pancreatic islets and beta-TC3 cells by TUNEL assay. Cellular ATP content, mitochondrial function and redox balance were examined. Phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) and the activation of nuclear erythroid factor 2 p45-related factor 2 (Nrf2) signaling were evaluated by western blotting. In db/db mice, OA significantly protects beta cell function against lipotoxicity, evidenced by inhibition of apoptosis and improvement of glucose tolerance. In cells, OA administration may protect against PA-induced apoptosis and decrease of GSIS, in which process the activation of Nrf2 is essential. Once Nrf2 is activated, OA could induce GCLc expression, promote the production of GSH, and thus inhibit JNK phosphorylation and solid the antioxidant defense of mitochondria, leading to the inhibition of mitochondrial apoptosis. ERK signaling pathway is responsible for OA-induced activation of Nrf2 and the protective effect of OA. Overall, our study enhances the understanding of the protective effect of OA on beta cell and provides clues for further studies on the underlying mechanisms.

optiCall: a robust genotype-calling algorithm for rare, low-frequency and common variants

Motivation: Existing microarray genotype-calling algorithms adopt either SNP-by-SNP (SNP-wise) or sample-by-sample (sample-wise) approaches to calling. We have developed a novel genotype-calling algorithm for the Illumina platform, optiCall, that uses both SNP-wise and sample-wise calling to more accurately ascertain genotypes at rare, low-frequency and common variants.

Results: Using data from 4537 individuals from the 1958 British Birth Cohort genotyped on the Immunochip, we estimate the proportion of SNPs lost to downstream analysis due to false quality control failures, and rare variants misclassified as monomorphic, is only 1.38% with optiCall, in comparison to 3.87, 7.85 and 4.09% for Illuminus, GenoSNP and GenCall, respectively. We show that optiCall accurately captures rare variants and can correctly account for SNPs where probe intensity clouds are shifted from their expected positions.

Availability and implementation: optiCall is implemented in C++ for use on UNIX operating systems and is available for download at http://www.sanger.ac.uk/resources/software/opticall/.

Contact:optiCall@sanger.ac.uk

Genome-wide association study of major depressive disorder: new results, meta-analysis, and lessons learned

Major depressive disorder (MDD) is a common complex disorder with a partly genetic etiology. We conducted a genome-wide association study of the MDD2000+ sample (2431 cases, 3673 screened controls and >1 M imputed single-nucleotide polymorphisms (SNPs)). No SNPs achieved genome-wide significance either in the MDD2000+ study, or in meta-analysis with two other studies totaling 5763 cases and 6901 controls. These results imply that common variants of intermediate or large effect do not have main effects in the genetic architecture of MDD. Suggestive but notable results were (a) gene-based tests suggesting roles for adenylate cyclase 3 (ADCY3, 2p23.3) and galanin (GAL, 11q13.3); published functional evidence relates both of these to MDD and serotonergic signaling; (b) support for the bipolar disorder risk variant SNP rs1006737 in CACNA1C (P=0.020, odds ratio=1.10); and (c) lack of support for rs2251219, a SNP identified in a meta-analysis of affective disorder studies (P=0.51). We estimate that sample sizes 1.8- to 2.4-fold greater are needed for association studies of MDD compared with those for schizophrenia to detect variants that explain the same proportion of total variance in liability. Larger study cohorts characterized for genetic and environmental risk factors accumulated prospectively are likely to be needed to dissect more fully the etiology of MDD.

Beneficial effects of jejunal continuity and duodenal food passage after total gastrectomy: a retrospective study of 704 patients

AIM

To evaluate effects of reconstruction procedures on post-operative outcomes and nutritional status after total gastrectomy.

METHODS

The study group comprised 704 consecutive patients with gastric cancer who underwent total gastrectomy between December 1985 and December 2003. Six alimentary reconstruction procedures were performed, including jejunal continuity [Braun, modified Braun I and II and functional jejunal interposition (FJI)] and jejunum transection ["P" Roux-en-Y and "P" jejunal interposition (PJI)]. The duodenal food passage was maintained only by FJI and PJI. We evaluated the time interval to restore food intake after surgery and the incidence of complications and nutritional status for 12 months.

RESULTS

Patients who received jejunum transection required 7.8+/-2.5 days and 11.9+/-4.9 days to restore liquid and semi-liquid food intake, respectively, which reduced to 3.9+/-2.1 days for liquid and 7.9+/-3.9 days for semi-liquid food intake by jejunum continuity. The incidence rates of reflux esophagitis and Roux-en-Y syndrome in patients receiving jejunum transection were 23.5% and 42.4%, respectively, which were decreased to 9.35% and 14.7%, respectively, by jejunal continuity. Furthermore, prognostic nutrition index score of patients receiving the procedures maintaining duodenal food passage (52.9+/-10.9) was higher than that of patients without the duodenal food passage (46.7+/-8.2).

CONCLUSION

Jejunal continuity and duodenal food passage showed beneficial effects on clinical outcomes after surgery. Among these six procedures, FJI was the only procedure to combine the benefits of jejunal continuity and maintaining the duodenal food passage, indicating that FJI has potential clinical application to improve the quality of patient's life after total gastrectomy.

Effect of dimethyl sulfoxide on post-thaw viability assessment of CD45+ and CD34+ cells of umbilical cord blood and mobilized peripheral blood

BACKGROUND

The effect of dimethyl sulfoxide (Me2SO) on enumeration of post-thaw CD45+ and CD34+ cells of umbilical cord blood (HPC-C) and mobilized peripheral blood (HPC-A) has not been systematically studied.

METHODS

Cells from leukapheresis products from multiple myeloma patients and umbilical cord blood cells were suspended in 1, 2, 5, or 10% Me2SO for 20 min at 22 degrees C. Cells suspended in Me2SO were then immediately assessed or assessed following removal of Me2SO. In other samples, cells were suspended in 10% Me2SO, cooled slowly to -60 degrees C, stored at -150 degrees C for 48 h, then thawed. The thawed cells in 10% Me2SO were diluted to 1, 2, 5, or 10% Me2SO, held for 20 min at 22 degrees C and then immediately assessed or assessed after the removal of Me2SO. CD34+ cell viability was determined using a single platform flow cytometric absolute CD34+ cell count technique incorporating 7-AAD.

RESULTS

The results indicate that after cryopreservation neither recovery of CD34+ cells nor viability of CD45+ and CD34+ cells from both post-thaw HPC-A and HPC-C were a function of the concentration of Me2SO. Without cryopreservation, when Me2SO is present recovery and viability of HPC-C CD34+ cells exposed to 10% Me2SO but not CD45+ cells were significantly decreased. Removing Me2SO by centrifugation significantly decreased the viability and recovery of CD34+ cells in both HPC-A and HPC-C before and after cryopreservation.

DISCUSSION

To reflect the actual number of CD45+ cells and CD34+ cells infused into a patient, these results indicate that removal of Me2SO for assessment of CD34+ cell viability should only be performed if the HPC are infused after washing to remove Me2SO.

Linear correlation between fractal dimension of EEG signal and handgrip force

Fractal dimension (FD) has been proved useful in quantifying the complexity of dynamical signals in biology and medicine. In this study, we measured FDs of human electroencephalographic (EEG) signals at different levels of handgrip forces. EEG signals were recorded from five major motor-related cortical areas in eight normal healthy subjects. FDs were calculated using three different methods. The three physiological periods of handgrip (command preparation, movement and holding periods) were analyzed and compared. The results showed that FDs of the EEG signals during the movement and holding periods increased linearly with handgrip force, whereas FD during the preparation period had no correlation with force. The results also demonstrated that one method (Katz's) gave greater changes in FD, and thus, had more power in capturing the dynamic changes in the signal. The linear increase of FD, together with results from other EEG and neuroimaging studies, suggest that under normal conditions the brain recruits motor neurons at a linear progress when increasing the force.

Microinjection of glutamate into dorsal motor nucleus of the vagus excites gallbladder motility through NMDA receptor - nitric oxide - cGMP pathway

We have reported that both glutamate and nitric oxide (NO) participated in the regulation of gallbladder motility in dorsal motor nucleus of the vagus (DMV). The aim of this study is to investigate the type of receptor in DMV that mediates the excitatory effect of glutamate on gallbladder motility and the correlation between the glutamate and NO. A frog bladder connected with a force transducer was inserted into the gallbladder to record the change of gallbladder pressure. Glutamate (65 mmol L(-1), 100 nL) microinjected into DMV significantly increased the strength of gallbladder phasic contraction. This effect was abolished by ketamine (180 mmol L(-1), 100 nL), the specific N-methyl-d-aspartic acid (NMDA) receptor antagonist, but was not influenced by 6-cyaon-7-nitroquinoxaline-2,3-(1H,4H)-dione (CNQX) (180 mmol L(-1), 100 nL), the non-NMDA ionotropic receptor antagonist. N(G)-nitro-l-arginine-emthyl (l-NAME) (1 mol L(-1), 100 nL), the nitric oxide synthase (NOS) inhibitor, reversed the excitatory effect of glutamate on gallbladder motility. Microinjection of sodium nitroprusside (SNP), the NO donor, into DMV enhanced the gallbladder motility, and this effect was not modulated by ketamine. Microinjection of NMDA (5 mmol L(-1), 100 nL) increased the strength of gallbladder phasic contraction, and this effect was attenuated by methylene blue (100 mmol L(-1), 100 nL), the soluble guanylate cyclase inhibitor. These results suggest that glutamate regulate the gallbladder motility through the NMDA receptor - NO - cGMP pathway in DMV.

The compound DATEM inhibits respiratory syncytial virus fusion activity with epithelial cells

The effect of diacetyltartaric acid esters of mono and diglycerides (DATEM) on fusion of respiratory syncytial virus (RSV) with HEp-2 cells was studied using the R18 fluorescence dequenching fusion assay. At DATEM concentrations less than 2.0 microg/ml, the inhibition of fusion increased with the concentration of DATEM. At 2 microg/ml of DATEM, the fusion was suppressed by 80-90%. Studies examining possible mechanism of fusion-inhibition indicated that DATEM was likely adsorbed onto lipid membranes of both viral envelope and target cell membranes. Quantitative measurements of DATEM adsorption onto membranes were also performed using lipid monolayers and vesicles. The surface pressure of lipid monolayer formed at the air/aqueous interface increased as the concentration of DATEM in the monolayer subphase increased, suggesting that DATEM was inserted into the monolayer. As the concentration of DATEM in vesicle suspensions increased, electrophoretic mobility of initially uncharged lipid vesicles also increased, reflective of increased negative charge at vesicle surfaces. These results strongly suggest that the insertion of DATEM onto membranes inhibited viral fusion. DATEM may prove to be effective in limiting the infectivity of RSV by interference with the fusion of the viral envelope with target cell membranes.

Functional magnetic resonance imaging before and after ventriculoperitoneal shunting for hydrocephalus--case report

A 70-year-old man with hydrocephalus was examined with functional magnetic resonance (fMR) imaging before and after ventriculoperitoneal shunting. Preoperatively, activation by right hand exercise revealed only a slight signal increase in the peri-rolandic area. However, 3 months after ventriculoperitoneal shunting, a significant signal increase was observed. fMR imaging may detect activity-related improvement of cerebral blood flow responses in patients with hydrocephalus after surgical treatment.

[Studies of hypoxic rat brain mitochondrial transcription activity in vitro]

AIM

To explore the effects of acute and chronic hypoxia on brain mitochondrial transcription activity in vitro of rats.

METHODS

Animal grouping: Wistar rats were randomized into acute hypoxic group (AH), chronic hypoxic group (CH) and the control. Mitochondrial transcription activity in vitro was measured in each group respectively as well as mitochondrial F0F1-ATPase activity, and effects of environmental ATP concentration on mitochondrial transcription activity in vitro was observed.

RESULTS

Brain mitochondrial transcription activity and F0F1-ATPase activity were marked depressed in AH while partly reversed in CH, and they were linearly related. Mitochondrial transcription activity in vitro was affected by ATP concentration diphasely.

CONCLUSION

Acute hypoxia may impair brain mitochondria energy metabolism by way of depressing mitochondrial transcription and then partially recover during chronic hypoxia. And mitochondrial transcription in vitro might be precisely regulated by ATP concentration.

Relationship between muscle output and functional MRI-measured brain activation

The relationship between functional MRI (fMRI)-measured brain signal and muscle force and or electromyogram (EMG) is critical in interpreting fMRI data and understanding the control mechanisms of voluntary motor actions. We designed a system that could record joint force and surface EMG online with fMRI data. High-quality force and EMG data were obtained while maintaining the quality of the fMRI brain images. Using this system, we determined the relationship between fMRI-measured brain activation and handgrip force and between fMRI-measured brain signal and EMG of extrinsic finger muscles. Ten volunteers participated in the experiments (only seven subjects' data were analyzed due to excessive noise in the fMRI data of three subjects). The participants exerted 20%, 35%, 50%, 65%, and 80% of the maximal force. During each contraction period, handgrip force, surface EMG of the finger flexor and extensor muscles, and fMRI brain images were acquired. The degree of muscle activation (force and EMG) was directly proportional to the amplitude of the brain signal determined by fMRI in the entire brain and in a number of motor function-related cortical fields, including primary motor, sensory regions, supplementary motor area, premotor, prefrontal, parietal and cingulate cortices, and cerebellum. All the examined brain areas demonstrated a similar relationship between the fMRI signal and force. A stronger fMRI signal during higher force indicates that more cortical output neurons and/or interneurons may participate in generating descending commands and/or processing additional sensory information. The similarity in the relationship between muscle output and fMRI signal in the cortical regions suggests that correlated or networked activation among a number of cortical fields may be necessary for controlling precise static force of finger muscles.

Skilled finger movement exercise improves hand function

BACKGROUND

Aging is accompanied by a marked decline in muscle strength and ability to maintain steady submaximal force. Studies have shown that exercise programs can improve age-related regression of hand function in elderly individuals. The purpose of this study was to train elderly subjects to perform skilled finger movements and to evaluate the changes in hand function involving skillful use of finger pinch.

METHODS

Grip strength, maximum pinch force (MPF), steadiness of pinch force at 5%, 10%, and 20% MPF, M wave, and Hoffman (H) reflex were measured. Fourteen elderly subjects were trained with skilled finger movements, and their performance involving finger pinch was measured.

RESULTS

Compared with untrained elderly subjects, the trained older adults significantly (p <.05) improved their ability to control submaximal pinch force, to maintain a steady hand posture, and to relocate a small object quickly with finger grip. The amplitude of H reflex increased significantly for the trained group.

CONCLUSIONS

Skilled finger movement training improves the ability to control submaximal pinch force, hand steadiness, and manual speed in elderly subjects; these improvements may be due to training-induced adaptations in the central and peripheral nervous systems.

[Allografting for massive bone defect: bone and soft tissue reconstruction and postoperative rehabilitation]

OBJECTIVE

To evaluate the results of limb function and the methods of bone and soft tissue reconstruction of patients treated with allografting.

METHODS

From May 1992 to January 1999, 90 patients suffered from bone malignant tumor were treated with allografting in different methods of internal fixations. The average follow-up was 37.5 months. The limb postoperative function, complications related to different surgical methods were compared according to Enneking evaluation system.

RESULTS

Skin necrosis, infection, non-union, fracture of allograft were the main complications which affect patients' limb postoperative functions. Of the 90 fresh-frozen allografting procedures, the final results of operation showed that hip joints and knee joints were better than the shoulder joints. More than 80% of the patients treated with interlocked intramedullary nail and allograft-prosthesis combination led to an over-all result that was excellent and good. Interlocked intermedullary nail was of recommended method of internal fixation. Early exercises of operative limbs could promote function recovery.

CONCLUSION

Using of interlocked intramedullary nail and allograft-prosthesis combination are of recommended operation method and can be applied with better results, and early exercises of operative limbs will lead to better functions.

DNA-binding and photocleavage studies of cobalt(III) mixed-polypyridyl complexes containing 2-(2-chloro-5-nitrophenyl)imidazo [4,5-f][1,10]phenanthroline

The ligand 2-(2-chloro-5-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline(CNOIP) and its complexes [Co(bpy)(2)(CNOIP)](3+) (1) and [Co(phen)(2)(CNOIP)](3+) (2) (bpy=2,2'-bipyridine; phen=1,10-phenanthroline) have been synthesized and characterized. Binding of the two complexes with calf thymus DNA has been investigated by spectroscopic methods, cyclic voltammetry, viscosity, and electrophoresis measurements. The experimental results indicate that both complexes bind to DNA through an intercalative mode. In comparison with their parent complexes containing PIP ligand (PIP=2-phenylimidazo[4,5-f][1,10]phenanthroline), the introduction of NO(2) and Cl groups to the PIP ligand decreased the binding affinity of complexes 1 and 2 to CT DNA. Both complexes have also been found to promote the photocleavage of plasmid pBR 322 DNA, the hydroxyl radical (OH*) is suggested to be the reactive species responsible for the cleavage.

[Effect of nucleus raphe obscurus on myoelectric activity of sphincter of Oddi in rabbits]

The aim of the present study was to investigate the role of nucleus raphe obscurus (NRO) in regulating the motility of sphincter of Oddi (SO). After fasting about l8~24 h, the rabbits were anesthetized with urethane (1.0 g/kg), and the myoelectric signals of SO were induced by a pair of copper electrodes inserted into the subsera. The results of microinjection of various drugs into NRO are as follows. After glutamate (340 mmol/L, 0.1 microl) was injected, activity of SO was excited. With microinjection of GABA (1 mol/L,0.1 microl), the spike burst of SO was inhibited. Following microinjection of ketamine (180 mmol/L, 0.1 microl), a kind of N-methyl-D-aspartate (NMDA) receptor antagonist, SO motility was inhibited and the effect of glutamate was abolished. Injection of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (2 mmol/L, 0.1 microl), a non-NMDA receptor antagonist, also excited the myoelectric activity of SO, but did not inhibit the effect of glutamate. The effect of glutamate was abolished by intravenous injection of atropine (0.2 mg/kg) or bilateral vagotomy, but not by injection of phentolamine (1.5 mg/kg) or propronalol (1.5 mg/kg), or by transection of the spinal cord. The above results indicate that NRO mediation of SO activity is due to the effect of glutamate on the NMDA receptors in the nucleus, the output of which is sent through vagal nerve and peripheral M cholinergic receptor to exert excitation of gallbladder motility.

Effect of a rippling mode on resonances of carbon nanotubes

A recent study determined the Young's modulus of carbon nanotubes by measuring resonance frequency and using the modulus-frequency relation resulting from the linear vibration theory. It leads to the report that the Young's modulus decreases sharply, from about 1 to 0.1 TPa with the diameter D increasing from 8 to 40 nanometers, and the investigators attributed this decrease to the emergence of an unusual bending mode during the measurement that corresponds to rippling on the inner arc of the bent nanotubes. The nonlinear analysis presented in this paper that captures the rippling mode suggests that the effective Young's modulus can indeed decrease substantially with increasing diameter, and that the results from the classical linear theory may be invalid in such measurements.

Effects of metal ions on simultaneous production of glucose oxidase and catalase by Aspergillus niger

The effects of various metal ions on the simultaneous production of glucose oxidase and catalase by Aspergillus niger were investigated. Calcium carbonate induced synthesis of both enzymes. The induction of calcium carbonate was accompanied by a metabolic shift from the glycolytic pathway (EMP, Embden-Meyerhof-Parnas) to direct oxidation of glucose by glucose oxidase. The time course of the biosynthesis of both enzymes is reported. The logistic model was in good agreement with the experimental growth results. The production of both enzymes was growth-associated. Finally, a model of growth and product formation was also proposed.

[A study on the expression of human leptin in the mammary glands of transgenic mice]

Human leptin expressed by E. coli had been used to treat human obesity in American and scientists had achieved good effects, the researchers here wanted to know whether human leptin can be expressed in the mammary glands of transgenic animas. In this study, human leptin gene about 1.0 kb, the terminator of rabbit whey acid protein gene (rWAP) about 0.2 kb and the promoter including the distal upstream region and part of the first exon of rWAP gene about 6.3 kb were used to construct a expression vector. Before we did the subclonings, the sequences of the human leptin gene were sequenced by ABI377 DNA Sequencer, the results showed that the fragment of human leptin gene included the last nine base pairs of the first exon, the complete sequences of the second exon(172 bp) and parts of the third exon(including part of the encoding sequences and part of the 3' untranslated region). The final expression vector was digested with NotI and a fragment of 7.5 kb was collected and dissolved in TE(10 mmol/L Tris.Cl, pH7.4; 0.1 mmol/L EDTA) for later microinjection. The concentration of DNA was about 2 micrograms/mL, the copy number in 1 mL was about 2.4 x 10(11), every 1 to 2 pL of the prepared DNA solution was microinjected into the mouse embryos at pronucleus stage. After standard microinjection procedures, 48 live mice were obtained. The tails of the mice were cut(about 0.1 g) at four weeks of age, genomic DNA was extracted and digested completely with EcoRI, two were confirmed to be transgenic mice(both were female) by Southern hybridization using DIG labeled human leptin gene as probe, transgenic rate among the mice born was about 4% (2/48). The two female transgenic mice(2# and C3) were mated with nontransgenic male mice. The two founder transgenic mice were segregated with their baby mice for at least three hours at the fifth day after parturition and were milked by intraperitoneal injection of 0.3 IU of oxytocin and udder massage. SDS-PAGE was used to analyze whether there were expression of human leptin in the milk of the two founder transgenic mice with the milk of non-transgenic mouse at fifth day after parturition as control. SDS-PAGE results showed that compared with the control there was a new band in both of the founder transgenic mice milk, and its molecular weight was about 16 kD, which was quite similar with that of the human leptin. The researchers estimated that the expression level of this protein in the milk of the transgenic mice was about 1-2 mg/mL.

[The vagus nerve coordinates the motion of gallbladder and sphincter of Oddi in the interdigestive period in rabbits]

AIM

To investigate the effect of vagus nerve on coordinating the motion of gallbladder (GB) and sphincter of Oddi (SO) in the interdigestive period in rabbits.

METHODS

Fasted for 15 h-18 h, but allowed to drink water, the rabbib were anesthetized with urethane (1.0 mg/kg, i.v.). In order to measure GB pressure, a frog bladder filled with normal saline was put into GB and connected to a transducer (TP-200T). Myoelectric signals of SO was recorded by a pair of copper electrodes.

RESULTS

In the interdigestive period, phasic contractions of GB (PCGB) and clusters of spike potentials of SO (CSPSO) was 1:1 correlated (Y = 0.962X + 0.587, r = 0.982, P < 0.01). That is, every PCGB was accompanied by one CSPSO. Microinjection of thyrotropin-releasing hormone (TRH, 0.8 nmol, 1 microliter) or monosodium glutamate (MSG, 2 mumol, 1 microliter) into dorsal vagal complex (DVC) enhanced the motility of GB and SO, and the 1:1 temporal relation between PCGB and CSPSO still existed. Vagotomy or intravenous injection of atropine inhibited the PCGB and the spike potentials of SO, and the 1:1 correlation between PCGB and CSPSO disappeared. The spike bursts of SO did not respond to the artificial rise of gallbladder pressure.

CONCLUSION

In the interdigestive period in rabbits, gallbladder and SO contract and relax rhythmically and simultaneously. This eoordinated motion between GB and SO is controlled by DVC via vagus nerve and peripheral M receptors.

The human factor IX gene as germline mutagen test: samples from Mainland China have the putatively endogenous pattern of mutation

Germline mutations are the major source of genetic variation that allows a species to evolve over time but at the cost of Mendelian disease and genetic predisposition to multifactorial diseases. Previous analyses have revealed that the pattern of germline mutations in the factor IX gene (F9) is similar among a variety of ethnically and geographically diverse populations and compatible with the ancient pattern that has shaped the mammalian genome. Here, we compare the pattern of germline mutation in a population of hemophilia B patients from Mainland China (n=66) to that in U.S. Caucasians, Blacks, and Mexican Hispanics and stratify by disease severity and ethnicity. The similar pattern of germline mutation in all ethnic groups studied to date provides additional data compatible with the inference that endogenous processes predominate in germline mutations.

Simultaneous measurement of human joint force, surface electromyograms, and functional MRI-measured brain activation

Functional magnetic resonance imaging (fMRI) has been increasingly used in studying human brain function given its non-invasive feature and good spatial resolution. However, difficulties in acquiring data from peripheral (e.g. information from muscle) during fMRI studies of motor function hinder interpretation of fMRI data and designing more sophisticated investigations. Here we describe a system that was designed to concurrently measure handgrip force, surface electromyograms (EMG) of finger flexor and extensor muscles, and fMRI of human brain. The system included a pressure transducer built in a hydraulic environment, a heavily shielded EMG recording element, and a visual feedback structure for online monitoring of force and/or EMG signal, by the subject positioned in the scanner during an fMRI experiment. System evaluation and subsequent fMRI motor function studies have indicated that by using this system, high quality force and EMG signals can be recorded without sacrificing the quality of the fMRI data.

Relationship between motor activity-related cortical potential and voluntary muscle activation

The purpose of this study was to investigate the relationship between EEG-derived motor activity-related cortical potential (MRCP) and voluntary muscle activation. Eight healthy volunteers participated in two experimental sessions. In one session, subjects performed isometric elbow-flexion contractions at four intensity levels [10%, 35%, 60%, and 85% maximal voluntary contraction (MVC)]. In another session, a given elbow-flexion force (35% MVC) was generated at three different rates (slow, intermediate, and fast). Thirty to 40 contractions were performed at each force level or rate. EEG signals were recorded from the scalp overlying the supplementary motor area (SMA) and contralateral sensorimotor cortex, and EMG signals were recorded from the skin surface overlying the belly of the biceps brachii and brachioradialis muscles during all contractions. In each trial, the force was used as the triggering signal for MRCP averaging. MRCP amplitude was measured from the beginning to the peak of the negative slope. The magnitude of MRCP from both EEG recording locations (sensorimotor cortex and SMA) was highly correlated with elbow-flexion force, rate of rising of force, and muscle EMG signals. These results suggest that MRCP represents cortical motor commands that scale the level of muscle activation.