Potential involvement of placental AhR in unexplained recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a common complication of pregnancy. Recent studies have demonstrated that the aryl hydrocarbon receptor (AhR) might play important roles in establishing and maintaining early pregnancy. In this study, we found that placental AhR protein levels were significantly lower and placental CYP1A1 mRNA levels were higher in unexplained RSA (URSA) patients than in control subjects. The results of immunohistochemical analyzes showed that placental AhR was expressed in syncytiotrophoblast cells and that the level of AhR was markedly lower in these cells in URSA subjects than in control subjects. β-Naphthoflavone (β-NF, an AhR ligand) at 5μM significantly inhibited proliferation and migration in HTR-8/SVneo cells and was associated with the activation of AhR. Moreover, overexpressing AhR in JAR cells significantly increased CYP1A1 mRNA levels and inhibited cell migration. These results indicate that AhR is highly activated in URSA placentas and that the activation of AhR in the placenta might impair trophoblast cell proliferation and migration, possibly leading to the occurrence of URSA.

Nano-level position resolution for particle tracking in digital in-line holographic microscopy

Three-dimensional particle tracking in biological systems is a quickly growing field, many techniques have been developed providing tracking characters. Digital in-line holographic microscopy is a valuable technique for particle tracking. However, the speckle noise, out-of-focus signals and twin image influenced the particle tracking. Here an adaptive noise reduction method based on bidimensional ensemble empirical mode decomposition is introduced into digital in-line holographic microscopy. It can eliminate the speckle noise and background of the hologram adaptively. Combined with the three-dimensional deconvolution approach in the reconstruction, the particle feature would be identified effectively. Tracking the fixed beads on the cover-glass with piezoelectric stage through multiple holographic images demonstrate the tracking resolution, which approaches 2 nm in axial direction and 1 nm in transverse direction. This would facilitate the development and use in the biological area such as living cells and single-molecule approaches.

Testing the mutant selection window hypothesis in vitro and in vivo with Staphylococcus aureus exposed to fosfomycin

The purpose of this study was to test the mutant selection window (MSW) hypothesis in vitro and in vivo with Staphylococcus aureus exposed to fosfomycin. With the in vitro time-kill studies, S. aureus ATCC 29213 [with a minimal concentration that inhibits colony formation by 99% (MIC99) of 2.2 μg/mL and a mutant prevention concentration (MPC) of 57.6 μg/mL] lost fosfomycin susceptibility at antibiotic concentrations (2×, 4×, and 8× MIC) that are between the lower and upper boundaries of the MSW. In the tissue-cage model, S. aureus was exposed to fosfomycin pharmacokinetics at concentrations below the MIC99, between the MIC99 and the MPC, and above the MPC, respectively. Changes in susceptibility and counts of total and resistant viable bacteria were monitored in tissue-cage fluid obtained daily. However, the selection of resistant mutants was not observed during antibacterial treatment and 48 h after the termination of fosfomycin treatment, regardless of the fosfomycin dosage. Besides, we found no differences between the in vitro-isolated mutant and its sensitive parental strain, which indicates the absence of fitness cost of fosfomycin resistance in S. aureus ATCC 29213. These findings demonstrate that agar plate determinations do not fit the MSW for fosfomycin treatment of rabbits infected with S. aureus ATCC 29213; therefore, the existence of the window must be demonstrated not only in vitro but also in vivo. Further research is needed on the exact mechanism of resistance.

CD38 and E2F transcription factor 2 have uniquely increased expression in rheumatoid arthritis synovial tissues

The purpose of the current study was to find novel rheumatoid arthritis (RA)-specific gene expression by simultaneously comparing the expression profiles of the synovial tissues from patients with RA, osteoarthritis (OA) and ankylosing spondylitis (AS). The Illumina Human HT-12 v4 Expression BeadChip was used to investigate the global gene expression profiles in synovial tissues from RA (n = 12), OA (n = 14) and AS (n = 7) patients. By comparing the profiles in synovial tissues from RA, OA and AS, we identified the CD38, ankyrin repeat domain 38 (ANKRD38), E2F transcription factor 2 (E2F2), craniofacial development protein 1 (CFDP1), cluster of differentiation (CD)7, interferon-stimulated exonuclease gene 20 kDa (ISG20) and interleukin-2 receptor gamma (IL)-2RG genes as differentially expressed gene expression in RA synovial tissues. The increased expression of CD38, E2F2 and IL-2RG, as revealed using real-time polymerase chain reaction (PCR) with synovial tissues from RA (n = 30), OA (n = 26) and AS patients (n = 20), was in agreement with the microarray data. Immunohistochemistry revealed significant CD38 expression and E2F2 in synovial membranes from RA patients (n = 5). The CD38(+) cells had high a percentage in the RA patients' blood (n = 103) and in the CD3(+) and CD56(+) subsets. The CD38(+) cell percentage was correlated significantly with RF level (P = 0·026) in RA patients. The IL-1α and IL-β levels were depressed significantly in the culture medium of RA synovial fibroblast cells (n = 5) following treatment with siRNAs targeting the E2F2 or CD38 genes. This study suggests that the uniquely increased expression of CD38 and E2F2 in RA synovial tissues contribute to the immunoactivation of the disease.

Orexin A-mediated stimulation of 3β-HSD expression and testosterone production through MAPK signaling pathways in primary rat Leydig cells

BACKGROUND

Orexin A (ORA) regulates food intake, energy metabolism, gastrointestinal and reproductive functions.

AIM

The purpose of this study was to demonstrate whether the expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) and testosterone was stimulated by ORA and mediated through mitogen-activated protein kinases (MAPK) in rat Leydig cells.

METHODS

Primary Leydig cells were isolated from male rat testes, cultured, and treated with ORA under various conditions.

RESULTS

Orexin receptor 1 (OX (1) R) mRNA, but not orexin receptor 2 mRNA, was detected in primary Leydig cells. ORA up-regulated the expression of OX( 1) R mRNA and protein in a dose-responsive manner and increased the phosphorylation of extracellular receptor kinase 1/2 (ERK1/2) and p38 MAPK levels, but did not affect the phosphorylation of the JNK MAPK. Phosphorylation of ERK1/2 and p38 MAPKs by ORA was blocked with U0126 and SB203580 inhibitors, respectively. An OX(1)R-specific inhibitor, SB334867, also blocked the phosphorylation of ERK1/2 and p38 by ORA. Inhibitor treatment also blocked 3β-HSD expression and testosterone production.

CONCLUSIONS

These results demonstrate that ORA activation of OX(1)R up-regulates 3β-HSD expression and testosterone production via the ERK1/2 and p38 MAPKs signaling pathways in primary rat Leydig cells.

Efficacy evaluation of two transgenic maize events expressing fused proteins to CrylAb-susceptible and -resistant Ostrinia furnacalis (Lepidoptera: Crambidae)

The Asian corn borer, Ostrinia furnacalis (GuenCe), is a major pest of maize in China. Transgenic Bt maize could provide an effective way to control this pest. However, the potential of resistance evolution has been documented in the laboratory-a CrylAb-resistant strain of Asian corn borer (Asian corn borer-AbR) could survive well on two Bt maize events, that is, MON810 and Bt11. Pyramided transgenic crops with multiple dissimilar Bt insecticidal proteins offer a superior route for pests control compared with that with one Bt single gene. In this study, two novel transgenic Bt maize events (N30 and V3), which contained a fused gene Cry1Ab/Cry2Aj and CrylAb /Vip3DA, respectively, were evaluated for their efficacy on protection against CrylAb-susceptible Asian corn borer (Asian corn borer-BtS) as well as their potential for dealing with the Asian corn borer-AbR. In laboratory bioassay, no neonate larvae of Asian corn borer-BtS fed on the whorl leaves, tassels, husks, silks, and kernels of N30 and V3 could survive at 96 h after infestation. In contrast, only 2.0-8.7% larvae died as they fed on non-Bt maize tissues. As Asian corn borer-AbR neonate larvae fed on N30 and V3 silks and kernels, 95.0% even more larvae were killed at 96 h after infestation, and all died at 168 h after infestation, while 10.0-11.67% larvae survived on non-Bt control. In the field test under artificial infestation at middle whorl leaf and silking stages of maize, there were no significant leaf, silk, and stalk damage on Bt maize plants by comparison with severe leaf feeding, stalk born, and ear damage in control, in addition, the expression profiles of a fused protein of CrylAb/Cry2Aj or CrylAb/Vip3DA in different tissues of N30 and V3 were also confirmed. In conclusion, it is clear that both Bt maize events (N30 and V3) show great potential for protecting maize from attack by Asian corn borer that has resistance to Cry1Ab protein.

Use of extracorporeal membrane oxygenation in tracheal surgery: a case series

OBJECTIVES

To review our experience of extracorporeal membrane oxygenation in airway management during tracheal surgery.

METHODS

A retrospective, observational study was conducted to evaluate the effectiveness of extracorporeal membrane oxygenation in tracheal surgery in Shanghai Chest Hospital between 2008 and 2012.

RESULTS

In all 91 tracheal surgeries, 7 high-risk cases used extracorporeal membrane oxygenation. The duration of extracorporeal membrane oxygenation support ranged from 10 min to 31 min. All extracorporeal membrane oxygenation patients underwent surgical procedures safely and there was no hospital mortality.

CONCLUSIONS

Although various advanced anesthesia techniques can ensure a safe airway in tracheal surgery in most cases, extracorporeal circulation plays an important role in high-risk cases.

Lamotrigine vs. lamotrigine plus divalproex in randomized, placebo-controlled maintenance treatment for bipolar depression

OBJECTIVE

To compare the maintenance efficacy of lamotrigine (Lam) to combination therapy of Lam+divalproex ER (Div) in recently depressed patients with bipolar disorder (BD).

METHOD

We randomized 86 BD I or II patients in a major depressive episode to 8 months of double-blind treatment with Lam+placebo or Lam+Div. To be eligible for randomization, patients had to achieve control of both depressive and manic symptoms during an open phase that included both Lam and Div.

RESULTS

Time to depressive episode did not differ significantly by Kaplan-Maier survival analysis (χ2=1.82, df=1, P=0.18). However, several secondary outcomes did show significant differences. The proportion of Lam+placebo patients who had at least one Montgomery-Asberg Depression Rating Scale (MADRS) score≥15 during the maintenance phase was 67% (30/45) compared with 44% (18/41) for the Lam+Div group (χ2=4.51, P=0.03). Among BD I patients assigned to Lam+placebo, 71.4% (25/35) had at least one visit with MADRS score≥15 compared with 36.7% (11/30) among Lam+Div patients (χ2=7.89, df=1, P=0.005).

CONCLUSION

Lam+Div generally provided greater maintenance efficacy than Lam alone for depressive indices in recently depressed BD patients.

Increased expression of alpha 1-anti-trypsin in the synovial tissues of patients with ankylosing spondylitis

OBJECTIVES

Evidence indicates that the hyperplasia and inflammation of synovial tissues are significantly related to the pathogenic process of ankylosing spondylitis (AS). Using a proteomics approach, we detected a significantly increased expression of alpha 1-anti-trypsin (ATA1) in synovial membranes of patients with AS.

METHODS

We continued to investigate the expression level and location of ATA1 in synovial tissue of AS. We also investigated the genetic effect of the gene encoding ATA1 on AS. Western blot analysis was applied to determine the expression of ATA1 in synovial tissues by comparing the expression profiles of AS (n=8), rheumatoid arthritis (RA, n=9) and osteoarthritis (OA, n=9) samples. Immunohistochemistry was used to localise the expression of ATA1 in the synovial membrane. Taqman method was used to genotype tag SNPs (rs2753934, rs2749531 and rs6575424) with 56 AS cases, 260 RA cases and 160 healthy controls.

RESULTS

We detected an increased expression of ATA1 in synovial membranes of AS as compared with samples from RA and OA. We immuno-localised the significant expression of ATA1 in AS tissues. No significant association was found between the ATA1 polymorphism and AS or RA. Haplotype analysis did not reveal a haplotype to be associated with AS or RA.

CONCLUSIONS

It has been reported that ATA1 is related with inflammation and new bone formation, two important features of AS. The current findings suggest that ATA1 contributes to the pathogenesis of AS by up-regulating the gene expression in the synovial tissues.

Evidence for the adaptive evolution of ORF5 gene of Porcine reproductive and respiratory syndrome virus isolated in China

Porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 gene encoding an envelope glycoprotein involved in humoral immunity is the most variable protein-coding gene of PRRSV. The present study aimed to identify potential selective pressures acting on the ORF5 gene of PRRSV isolates of North American type prevalent in China. The non-synonymous to synonymous rate ratio ω (dN/dS) was employed as a measure of selective pressure at the codon level. An overall ω of 0.45 indicated negative (purifying) selection as the major driving force operating on the ORF5 gene during adaptation of the virus to swine. Determination of ω values for individual amino acids sites revealed 8 positively selected sites, most of them situated in the N-terminal ectodomain, indicating their potential role in the binding of virus to the cellular receptors. Further, 75 negatively selected sites were identified in the rest of molecule, probably as a result of functional or immunological constraints. Determination of potential N-glycosylation sites revealed 7 sites, four of which coincided with the positively selected ones. These results indicated that a specific adaptive evolution has operated on the ORF5 gene of Chinese PRRSV isolates. It is hoped that the disclosed adaptive sites might help identify a candidate antigenic epitope for the use in vaccine against this serious swine disease.

Though with constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network

Chloroplasts evolved as a result of endosymbiosis, during which sophisticated mechanisms evolved to translocate nucleus-encoded plastid-targeted enzymes into the chloroplast to form the chloroplast metabolic network. Given the constraints and complexity of endosymbiosis, will preferential attachment still be a plausible mechanism for chloroplast metabolic network evolution? We answer this question by analysing the metabolic network properties of the chloroplast and a cyanobacterium, Synechococcus sp. WH8102 (syw). First, we found that enzymes related to more ancient pathways are more connected, and synthetases have the highest connectivity. Most of the enzymes shared by the two densest cores between the chloroplast and syw are synthetases. Second, the highly conserved functional modules mainly consist of highly connected enzymes. Finally, isozymes and enzymes from endosymbiotic gene transfer (EGT) were distributed mainly in conserved modules and showed higher connectivity than nonisozymes or non-EGT enzymes. These results suggest that even with severe evolutionary constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network. However, the current analysis may not completely differentiate whether the chloroplast network properties reflect the evolution of the chloroplast network through preferential attachment or has been inherited from its cyanobacterial ancestor. To fully differentiate these two possibilities, further analyses of the metabolic network structure properties of organisms at various intermediate evolutionary stages between cyanobacteria and the chloroplast are needed.

Clinical study and PLA2G6 mutation screening analysis in Chinese patients with infantile neuroaxonal dystrophy

BACKGROUND AND PURPOSE

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder. The most typical neuropathological finding of this disease is axonal swelling. Before the identification of associated mutations in PLA2G6-encoding iPLA(2)-VIA (cytosolic Ca(2+)-independent phospholipids A(2), group VIA) in 2006, neuropathological evidence was critical for definitive diagnosis. Only five genetic studies in INAD patients have been published worldwide, wherein 44 mutations were reported. To define the clinical and genetic characteristics of Chinese patients with INAD, 10 cases were analyzed.

METHODS

For 10 cases of INAD, extensive clinical investigations, neuropathological examination, and mutation screening in PLA2G6 were performed.

RESULTS

All cases displayed typical clinical features. Axonal swelling was found in skin or sural nerve biopsy specimens in three cases. Twelve PLA2G6 mutations were identified, nine of which were novel. These novel mutations include six missense, one abolishing the normal start codon, one nonsense, and one splice-site mutation.

CONCLUSIONS

The nine novel mutations identified in this study suggest the uniqueness of the PLA2G6 mutation spectrum in Chinese patients, and greatly extends the spectrum of known mutations in INAD patients. In addition to pathological evidence, genetic analysis can inform definitive diagnosis of INAD.

Aberrant promoter methylation and tumor suppressive activity of the DFNA5 gene in colorectal carcinoma

To identify novel methylated gene promoters, we compared differential RNA expression profiles of colorectal cancer (CRC) cell lines with or without treatment of 5-aza-2'-deoxycytidine (5-aza-dC). Out of 1776 genes that were initially 'absent (that is, silenced)' by gene expression array analysis, we selected 163 genes that were increased after 5-aza-dC treatment in at least two of three CRC cell lines. The microarray results were confirmed by Reverse Transcription-PCR, and CpG island of the gene promoters were amplified and sequenced for examination of cancer-specific methylation. Among the genes identified, the deafness, autosomal dominant 5 gene, DFNA5, promoter was found to be methylated in primary tumor tissues with high frequency (65%, 65/100). Quantitative methylation-specific PCR of DFNA5 clearly discriminated primary CRC tissues from normal colon tissues (3%, 3/100). The mRNA expression of DFNA5 in four of five colon cancer tissues was significantly downregulated as compared to normal tissues. Moreover, forced expression of full-length DFNA5 in CRC cell lines markedly decreased the cell growth and colony-forming ability whereas knockdown of DFNA5 increased cell growth in culture. Our data implicate DFNA5 as a novel tumor suppressor gene in CRC and a valuable molecular marker for human cancer.

Development of the bipolar inventory of symptoms scale

OBJECTIVE

Most rating scales for bipolar disorders (BDs) do not encompass the spectrum of symptomatology now established as characterizing the illness. We report the rationale, format, reliability and initial validity studies of the Bipolar Inventory of Symptoms Scale (BISS), a 44-item scale designed to encompass the spectrum of behavioral disturbances in BDs.

METHOD

Structured video interviews of 20 patients representing four bipolar syndromal subtypes were rated by nine raters.

RESULTS

Generally, high inter-rater reliability and internal consistency were established for the depression and mania subscales and the BISS total score. The BISS discriminated across subtypes of bipolar patients with depressed, manic/hypomanic, mixed manic or recovered status.

CONCLUSION

The BISS has adequate reliability, concurrent validity and is capable of discriminating between bipolar subtypes. It also provides a comprehensive scale to assess discrete behavioral components of BD.

Glucagon-like peptide-2 protects against TPN-induced intestinal hexose malabsorption in enterally refed piglets

Premature infants receiving chronic total parenteral nutrition (TPN) due to feeding intolerance develop intestinal atrophy and reduced nutrient absorption. Although providing the intestinal trophic hormone glucagon-like peptide-2 (GLP-2) during chronic TPN improves intestinal growth and morphology, it is uncertain whether GLP-2 enhances absorptive function. We placed catheters in the carotid artery, jugular and portal veins, duodenum, and a portal vein flow probe in piglets before providing either enteral formula (ENT), TPN or a coinfusion of TPN plus GLP-2 for 6 days. On postoperative day 7, all piglets were fed enterally and digestive functions were evaluated in vivo using dual infusion of enteral ((13)C) and intravenous ((2)H) glucose, in vitro by measuring mucosal lactase activity and rates of apical glucose transport, and by assessing the abundances of sodium glucose transporter-1 (SGLT-1) and glucose transporter-2 (GLUT2). Both ENT and GLP-2 pigs had larger intestine weights, longer villi, and higher lactose digestive capacity and in vivo net glucose and galactose absorption compared with TPN alone. These endpoints were similar in ENT and GLP-2 pigs except for a lower intestinal weight and net glucose absorption in GLP-2 compared with ENT pigs. The enhanced hexose absorption in GLP-2 compared with TPN pigs corresponded with higher lactose digestive and apical glucose transport capacities, increased abundance of SGLT-1, but not GLUT-2, and lower intestinal metabolism of [(13)C]glucose to [(13)C]lactate. Our findings indicate that GLP-2 treatment during chronic TPN maintains intestinal structure and lactose digestive and hexose absorptive capacities, reduces intestinal hexose metabolism, and may facilitate the transition to enteral feeding in TPN-fed infants.

Citrullination of fibronectin in rheumatoid arthritis synovial tissue

OBJECTIVES

Citrullination, catalysed by peptidylarginine deiminase (PAD), is the post-translational modification of peptidylarginine to citrulline, which is intimately involved in the pathogenesis of rheumatoid arthritis (RA). Fibronectin (Fn), a large glycoprotein, is expressed at high levels in arthritic joints and it mediates various physiological processes through interactions with cell-surface integrin receptors and growth factors. We investigated the citrullination of Fn and its potential contribution to the pathogenesis of RA.

METHODS

We localized Fn expression and citrullination in RA synovial tissue by immunohistochemistry, immunoprecipitation and western blotting. We also determined levels of citrullinated Fn in plasma from RA patients using sandwich enzyme-linked immunosorbent assay (ELISA). After incubating Fn with rabbit skeletal muscle PAD, we examined the binding ability of citrullinated Fn to vascular endothelial growth factor (VEGF) and integrin beta1 using a solid-phase receptor binding assay as well as the effect of the citrullinated Fn on apoptosis using cultured HL-60 cells.

RESULTS

Immunohistochemistry and western blotting analysis indicated that Fn formed extracellular aggregates that were specifically citrullinated in RA synovial tissue. No Fn deposits were observed in synovial tissues of osteoarthritis (OA). Sandwich ELISA detected higher levels of citrullinated Fn in plasma from patients with RA than from healthy controls or those with systemic lupus erythematosus. Following citrullination in vitro, the affinity of Fn for VEGF increased, but binding activity to integrin beta1 decreased and Fn no longer stimulated the apoptosis of monocytes induced from cultured HL-60 cells.

CONCLUSIONS

Our results suggest that the citrullination of Fn is a specific event for RA synovium, although others have detected citrullinated total proteins in inflamed synovial tissue of RA and non-RA patients. Citrullination of Fn could alter interactions between Fn and its receptors and growth factors, consequently contributing to mechanisms of RA pathogenesis such as perturbed angiogenesis and apoptosis.

CUL1, a component of E3 ubiquitin ligase, alters lymphocyte signal transduction with possible effect on rheumatoid arthritis

Ubiquitination affects various immune processes and E3 ubiquitin ligases (E3) play an important role in determining substrate specificity. We identified 11 human E3 ligase genes of potential importance in pathogenesis of autoimmune diseases by search of public databases and screened them for candidacy of biological investigation with case-control linkage disequilibrium tests on multiple SNPs in the genes using rheumatoid arthritis (RA) as a model of autoimmune diseases. Significant association with RA was observed in an SNP in intron 3 of Cullin 1 (CUL1) that affected transcriptional efficiency of the promoter activity in lymphocytic cell lines. Quantitative expression analysis revealed that CUL1 mRNA was highly detected in lymphoid tissues including spleen and tonsil, and was specifically expressed in T and B lymphocytes in fractionated peripheral leukocytes. Histological evaluation of tonsils indicated that CUL1 protein expression was relatively specific for maturing germinal centers. Suppression of CUL1 expression had influence on the phenotype of T-cell line, that is, it inhibited IL-8 induction, which is known to play an important role in the migration of inflammatory cells into the affected area seen in RA. Our data suggest that the regulation of CUL1 expression in immunological tissues may affect the susceptibility of RA via altering lymphocyte signal transduction.

The inhibition of antithrombin by peptidylarginine deiminase 4 may contribute to pathogenesis of rheumatoid arthritis

OBJECTIVE

The gene for peptidylarginine deiminase 4 (PADI4) has been found to be closely associated with rheumatoid arthritis (RA). Peptidylarginine deiminase (PADI) catalyses the post-translational modification of peptidylarginine to citrulline, a reaction known as citrullination. PADI extracted from rabbit muscle has been reported to citrullinate antithrombin, a principal plasma inhibitor of thrombin. Thrombin is known to induce angiogenesis, fibrin formation and inflammation, the primary events of the RA joint. Here, we investigate whether human PADI4 can inhibit antithrombin by catalysing antithrombin citrullination and how the enzyme is involved in RA pathogenesis.

METHODS

Antithrombin was incubated with recombinant PADI4 protein, and the inactivation of antithrombin was determined by reduction of its thrombin-inhibiting activity. Citrullination of antithrombin was detected by western blotting and enzyme-linked immunosorbent assay (ELISA). In addition, the citrullination level, activity and concentration of antithrombin in RA plasma were investigated by sandwich ELISA.

RESULTS

Incubation of antithrombin with PADI4 resulted in loss of thrombin-inhibitory activity and in citrullination of antithrombin. RA plasma showed higher levels of citrullinated antithrombin than controls with non-arthritis disease and healthy individuals.

CONCLUSION

The results indicate that PADI4 could inactivate antithrombin through citrullination. The abnormal expression or activation of PADI4 in RA synovium is suggested to be responsible for the high level of citrullinated antithrombin in RA plasma. Local inhibition of antithrombin activity in RA synovium might lead to the excessive angiogenesis, fibrin deposition and inflammation of the tissue.

Localization of peptidylarginine deiminase 4 (PADI4) and citrullinated protein in synovial tissue of rheumatoid arthritis

OBJECTIVES

Peptidylarginine deiminases (PADIs) convert peptidylarginine into citrulline via post-translational modification. Anti-citrullinated peptide antibodies are highly specific for rheumatoid arthritis (RA). Our genome-wide case-control study of single-nucleotide polymorphisms found that the PADI4 gene polymorphism is closely associated with RA. Here, we localized the expression of PADI4 and the citrullinated protein product in synovial RA tissue.

METHODS

We used immunohistochemistry, double immunofluorescent labelling and western blotting.

RESULTS

We found that PADI4 is extensively expressed in T cells, B cells, macrophages, neutrophils, fibroblast-like cells and endothelial cells in the lining and sublining areas of the RA synovium. We also found extracellular and intracellular expression of PADI4 in fibrin deposits with loose tissue structures where apoptosis was widespread. Unlike PADI4, citrullinated protein generally appeared in fibrin deposits that were abundant in the RA synovium. The citrullinated fibrin aggregate was immunoreactive against immunoglobulin (Ig) A and IgM, but not IgG and IgE. Although a little PADI4 was expressed in osteoarthritic and normal synovial tissues, significant citrullination was undetectable.

CONCLUSIONS

The results showed that PADI4 is mainly distributed in cells of various haematopoietic lineages and expressed at high levels in the inflamed RA synovium. The co-localization of PADI4, citrullinated protein and apoptotic cells in fibrin deposits suggests that PADI4 is responsible for fibrin citrullination and is involved in apoptosis. The immunoreactivity of citrullinated fibrin with IgA and IgM in the RA synovium supports the notion that citrullinated fibrin is a potential antigen of RA autoimmunity.

Mechanosensitive channel currents recorded in rat microvascular endothelial cells with whole-cell mode

Using the whole-cell patch-clamp technique, we recorded delayed outward currents in rat brain microvascular endothelial cells (BRMECs), which were nearly completely inhibited by 20 mmol/L extracellular TEA-Cl and 5 mM extracellular CsCl. Whole-cell currents were elicited under voltage clamp condition by 2100 ms depolarizing voltage pulses applied every 7 s between -100 to 90 mV in 10 mV increment from a holding potential of -100 mV. The currents were defined as delayed rectified K+ currents (IKv), which were inhibited in a concentration-dependent manner by bath application of TEA-Cl, with an IC50 approximately 2.0 mM, similar to that reported on IKv in other preparations. In the present of mechanical force, outward currents were increased in amplitude as compared with controls. These mechanical force induced currents were also defined as IKv, which are different from previous described mechanosensitive currents with characteristic of inward rectifier.

Effects of maturation-inducing hormone on heterologous gap junctional coupling in ovarian follicles of Atlantic croaker

A previous ultrastructural study of heterologous (granulosa cell-oocyte) gap junction (GJ) contacts in ovarian follicles of Atlantic croaker suggested that these contacts disappear late during the process of resumption of oocyte meiosis. This observation suggested that, unlike scenarios proposed for a number of other species, uncoupling of GJ is not necessary for the onset of meiotic resumption in croaker follicles. However, the functionality of heterologous GJ contacts and the temporal association between maturation-inducing hormone (MIH)-induced changes in heterologous coupling and resumption of oocyte meiosis have not been examined in Atlantic croaker. These questions were addressed with a cell-cell coupling assay that is based on the transfer of a GJ marker, Lucifer Yellow, from oocytes to granulosa cells. Follicle-enclosed oocytes injected with Lucifer Yellow allowed transfer of the dye into the follicle cell layer, thus confirming that there is functional heterologous coupling between the oocyte and the granulosa cells. Dye transfer was observed in vitellogenic, full-grown/maturation-incompetent, and full-grown/maturation-competent follicles. Treatment of maturation-competent follicles with MIH caused a time-dependent decline in the number of follicles transferring dye. However, although GJ uncoupling in some of the follicles was observed before germinal vesicle breakdown (GVBD, index of meiotic resumption), about 50% of the follicles maintained the ability to transfer dye even after GVBD had occurred. Further, a known GJ inhibitor (phorbol 12-myristate 13-acetate) blocked heterologous GJ within a time frame similar to that seen with MIH but without inducing any of the morphological changes (including GVBD) associated with follicular maturation. In conclusion, uncoupling of heterologous GJ seems insufficient and unnecessary for the onset of meiotic resumption in ovarian follicles of Atlantic croaker.

The affects of acupuncture at sibai and neiting acupoints on gastric peristalsis

The frequency and amplitude of gastric peristaltic wave were significantly changed in 15 subjects when Sibai (ST 2) and Neiting (ST 44) acupoints of the Stomach Channel of Foot-Yangming were punctured. The results demonstrate that these acupoints are effective for treatment of stomach diseases, providing an experimental basis for the theory of channels and collaterals.

Aberrant induction of Par-4 is involved in apoptosis of hippocampal neurons in presenilin-1 M146V mutant knock-in mice

Mutations in presenilin-1 (PS-1) have been shown to increase neuronal vulnerability to apoptosis in Alzheimer's disease (AD). Par-4 is a novel cell-death-promoting protein associated with neuronal degeneration in AD. We previously reported that, in transfected PC12 cells, Par-4 seems to be involved in the neurodegenerative mechanisms of PS-1 mutations. However, direct evidence for a necessary role of Par-4 in the pathogenic mechanisms of PS-1 mutations in neurons is lacking. We recently generated and characterized presenilin-1 mutant M146V knock-in (PS-1 M146V KI) mice. We now report that expression of the mutant presenilin-1 in these mice induces early and exaggerated increase in Par-4 expression in hippocampal neurons following glucose deprivation (an insult relevant to the pathogenesis of AD). Importantly, inhibition of Par-4 expression by antisense par-4 oligonucleotide treatment counteracts neuronal apoptosis promoted by M146V mutation of PS-1. Mitochondrial dysfunction and caspase-3 activity induced by glucose deprivation was significantly exacerbated in hippocampal neurons expressing the mutant PS-1. Antisense par-4 treatment largely suppressed the adverse effect of the mutant PS-1 on mitochondrial dysfunction and caspase activation. These results provide evidence in hippocampal neurons that Par-4 is involved in the neurodegenerative cascades associated with PS-1 M146V mutation by acting relatively early in the apoptotic process before mitochondrial dysfunction and caspase-3 activation. Since levels of Par-4 are significantly increased in the hippocampus in human AD brain, the results of this study may provide a significant link between aberrant induction of Par-4 and the neurodegenerative cascades promoted by PS-1 mutations in AD.

Localization of estrogen receptor alpha and beta RNA in germinal and nongerminal epithelia of the channel catfish testis

The germinal epithelium of the anterior region of the channel catfish testis is the site of spermatogenesis, whereas the nongerminal epithelium of the posterior region (seminal vesicle) may play a role in the regulation of seminal fluid composition. The available information indicates that estrogens play a physiological role in the regulation of spermatogenesis and seminal fluid composition in vertebrates. However, the cellular distribution of estrogen receptor (ER) gene expression in the teleost testis is poorly understood. Therefore, the objective of this study was to determine the presence and cellular distribution of ERalpha and ERbeta transcripts in germinal and nongerminal epithelia of the mature testis of channel catfish. RT-PCR of whole-testis RNA extracts showed that ERalpha and ERbeta RNAs are present in the mature testis. In situ hybridization of histological sections of the germinal epithelium showed that primary spermatocytes contain little or no ERalpha or ERbeta RNA. However, both ER transcripts were present in secondary spermatocytes and spermatids and their levels were relatively high in mature sperm. The columnar epithelium of the seminal vesicle also contained ERalpha and ERbeta RNA. The ER RNAs in epithelial cells of the seminal vesicle were not evenly distributed throughout the cytoplasm but seemed to concentrate in their apical region, near the nucleus. In conclusion, ERalpha and ERbeta genes are coexpressed in germinal and nongerminal epithelia of the mature testis of channel catfish and seem to be developmentally regulated in spermatocytes. These observations are consistent with the concept that estrogens, via interaction with ERalpha and ERbeta, participate in the regulation of male gamete development and fertility.

Comparative experimental study of Ho-Yag laser and true-cut biopsy needle in myocardial revascularization

OBJECTIVE

To study the mechanism and effects of blood perfusion on acute ischemic region of myocardium through channel created by Ho-Yag laser and True-cut biopsy needles with myocardial contrast echocardiography.

METHODS

We partially ligated the left anterior descending coronary artery of canine hearts between the 1st and 2nd diagonal branches to produce two groups of acute myocardial ischemia models and then performed transmyocardial revascularization (TMR) on this region with Ho-Yag laser and True-cut biopsy needles. Myocardial contrast echocardiography was performed with a new generation of ultrasound contrast agent and second harmonic imaging of this region before, during ischemia and after revascularization. Pictures were taken with "R" wave trigger skill.

RESULTS

Acoustic density (dB) in the ischemic region (anterior wall) with myocardial contrast echocardiography decreased obviously after the left anterior descending artery was ligated (Laser group: 5, 40 +/- 1.81, Needle group: 7.11 +/- 2.51) compared with that before (Laser group: 11.69 +/- 1.61, Needle group: 12.96 +/- 2.88, P < 0.01). dB increased remarkably after TMR by either laser or True-cut biopsy needle (Laser group: 11.02 +/- 2.01, Needle group: 10.01 +/- 4.45. P < 0.01) compared to that during ischemia and approximated to that before ischemia (P > 0.05). We found that the acoustic density of the contrast developed one picture (one cardiac cycle) ahead in the transmyocardial revascularization region than that in the lateral and other region of the left ventricle wall in the scan of both groups.

CONCLUSIONS

Acute ischemic myocardium can be perfused immediately by oxygenated blood from the left ventricle through channels created with both Ho-Yag laser and True-cut biopsy needles. Evidence of blood perfusion through these channels mainly during systolic phase was detected, and myocardial contrast ultrasound using intravenous perfluorocarbon-exposed sonicated dextrose albumin was regarded as a reliable method in the study of transmyocardial revascularization.

[A new briquetting method for biomass coal and its influencing factors]

Regarding to the limitation and low economical efficiency of conventional biomass coal briquetter determined by its briquetting method, a new briquetting mechanism using the linkage function of biomass fiber was established. The effect of different coal, briquetting pressure, biomass shape and content, water content on new brequtting mechanism was studied preliminarily. The results showed that the new mechanism was suitable for varied kinds coal and biomass. The briquette mechanical performance was improved as biomass content increased with a reasonable low limitation of about 15%. Pure biomass also could be briquetted. The briquetting pressure which could consolidate the linkage of biomass fiber was no more than 120 MPa. There would be a negative effect at too high pressure. Increasing biomass content and decreasing pressure at certain degree could offset the negative effect of water content significantly, with a permissive limitation over 10% for Datong coal.

Par-4 is a synaptic protein that regulates neurite outgrowth by altering calcium homeostasis and transcription factor AP-1 activation

Although Par-4 (prostate apoptosis response-4) is involved in initiation of neurodegenerative cascades associated with certain neurodegenerative disorders, normal physiological roles of Par-4 in neurons have remained elusive. It was recently reported that Par-4 protein levels could be regulated at translational level in synaptic terminals following apoptotic insults, suggesting that Par-4 might play a role in synaptic function. We report that Par-4 is a synaptic protein preferably localized in postsynaptic density (PSD). The expression of Par-4 in synaptosome preparations and PSDs are developmentally and regionally regulated. Synaptic Par-4 is enriched in the cerebral cortex and the hippocampus, but not in the cerebellum. In vitro as well as in vivo experiments demonstrate that the levels of synaptic Par-4 increase as the neurons mature. Overexpression of Par-4 in transfected PC12 cells inhibits nerve growth factor (NGF)-induced cellular differentiation and neurite outgrowth by a mechanism involving aberrant elevation of intracellular calcium levels and suppression of activation of the transcription factor AP-1. The actions of Par-4 were consistently blocked by co-expression of the dominant negative regulator of Par-4 activity (the leucine zipper domain of Par-4). Since the leucine zipper domain of Par-4 (Leu.zip) may mediate protein--protein interactions, the results indicate that the actions of Par-4 require its interaction with other protein(s) or dimerization with itself. These results suggest that Par-4 may play an important role in postsynaptic signal transduction and regulation of cellular pathways associated with cellular differentiation and neurite outgrowth. Identification of Par-4 as a novel synaptic protein may have significant implications in understanding the mechanisms of synaptic functions in physiological and pathological settings.

Prostate apoptosis response-4 enhances secretion of amyloid beta peptide 1-42 in human neuroblastoma IMR-32 cells by a caspase-dependent pathway

Prostate apoptosis response-4 (Par-4) is a leucine zipper protein that promotes neuronal cell death in Alzheimer's disease (AD). Neuronal degeneration in AD may result from extracellular accumulation of amyloid beta peptide (Abeta) 1-42. To examine the effect of Par-4 on Abeta secretion and to reconcile amyloid/apoptosis hypotheses of AD, we generated IMR-32 cell lines that overexpress Par-4 and/or its leucine zipper domain. Overexpression of Par-4 did not significantly affect levels of the endogenously expressed beta amyloid precursor protein but drastically increased the Abeta(1-42)/Abeta(total) ratio in the conditioned media about 6-8 h after trophic factor withdrawal. Time course analysis of caspase activation reveals that Par-4 overexpression exacerbated caspase activation, which is detectable within 2 h after trophic factor withdrawal. Furthermore, inhibition of caspase activity by the broad spectrum caspase inhibitor BD-fmk significantly attenuated the Par-4-induced increase in Abeta 1-42 production. In addition, the effects of Par-4 on secretion of Abeta 1-42 were consistently blocked by co-expression of the leucine zipper domain, indicating that the effect of Par-4 on Abeta secretion may require its interaction with other protein(s). These results suggest that Par-4 increases secretion of Abeta 1-42 largely through a caspase-dependent pathway after apoptotic cascades are initiated.

Nucleotide-induced conformational changes in the human multidrug resistance protein MRP1 are related to the capacity of chemotherapeutic drugs to accumulate or not in resistant cells

Intracellular accumulation of anthracycline derivatives was measured in a human embryonic kidney cell line (HEK) and a resistant subline (HEK/multidrug resistance protein (MRP1)) overexpressing MRP1 at the plasma membrane surface. Two compounds (daunorubicin and doxorubicin) were rejected outside the multidrug-resistant cells. On the contrary, three compounds (4'-deoxy-4'-iodo-doxorubicin, 4-demethoxy-daunorubicin and 3'-(3-methoxymorpholino)doxorubicin) accumulated equally within sensitive HEK cells and resistant HEK/MRP1 cells. Our main objective here was to characterize the MRP1 conformational changes mediated by the binding of these anthracycline derivatives and to determine whether these conformational changes are related to MRP1-mediated drug transport. MRP1 was reconstituted in lipid vesicles as previously described [Manciu, L., Chang, X.B., Riordan, J.R. and Ruysschaert, J.-M. (2000) Biochemistry 39, 13026-13033]. The reconstituted protein was shown to conserve its ATPase and drug transport activity. Acrylamide quenching of Trp fluorescence was used to monitor drug-dependent conformational changes. Binding of drugs (4-demethoxy-daunorubicin and 3'-(3-methoxymorpholino)doxorubicin) which accumulate in resistant cells immobilizes MRP1 in a conformational state that is insensitive to ATP binding whereas drugs rejected outside the resistant cells (daunorubicin, doxorubicin) favor a conformational change which may be a required step in the transport process.

Novel transcripts of the estrogen receptor alpha gene in channel catfish

Complementary DNA libraries from liver and ovary of an immature female channel catfish were screened with a homologous ERalpha cDNA probe. The hepatic library yielded two new channel catfish ER cDNAs that encode N-terminal ERalpha variants of different sizes. Relative to the catfish ERalpha (medium size; 581 residues) previously reported, these new cDNAs encode Long-ERalpha (36 residues longer) and Short-ERalpha (389 residues shorter). The 5'-end of Long-ERalpha cDNA is identical to that of Medium-ERalpha but has an additional 503-bp segment with an upstream, in-frame translation-start codon. Recombinant Long-ERalpha binds estrogen with high affinity (K(d) = 3. 4 nM), similar to that previously reported for Medium-ERalpha but lower than reported for catfish ERbeta. Short-ERalpha cDNA encodes a protein that lacks most of the receptor protein and does not bind estrogen. Northern hybridization confirmed the existence of multiple hepatic ERalpha RNAs that include the size range of the ERalpha cDNAs obtained from the libraries as well as additional sizes. Using primers for RT-PCR that target locations internal to the protein-coding sequence, we also established the presence of several ERalpha cDNA variants with in-frame insertions in the ligand-binding and DNA-binding domains and in-frame or out-of-frame deletions in the ligand-binding domain. These internal variants showed patterns of expression that differed between the ovary and liver. Further, the ovarian library yielded a full-length, ERalpha antisense cDNA containing a poly(A) signal and tail. A limited survey of histological preparations from juvenile catfish by in situ hybridization using directionally synthesized cRNA probes also suggested the expression of ERalpha antisense RNA in a tissue-specific manner. In conclusion, channel catfish seemingly have three broad classes of ERalpha mRNA variants: those encoding N-terminal truncated variants, those encoding internal variants (including C-terminal truncated variants), and antisense mRNA. The sense variants may encode functional ERalpha or related proteins that modulate ERalpha or ERbeta activity. The existence of ER antisense mRNA is reported in this study for the first time. Its role may be to participate in the regulation of ER gene expression.

Hormonal regulation and cellular distribution of connexin 32.2 and connexin 32.7 RNAs in the ovary of Atlantic croaker

The in vitro effects of human chorionic gonadotropin (hCG) on ovarian connexin (Cx) 32.2 and 32.7 RNA levels and ovarian follicle maturation were assessed, and the cellular distribution of Cx transcripts in the ovary was determined. hCG caused a concentration-dependent induction of Cx32.2 RNA, which peaked coincidentally with the appearance of morphological indices of oocyte maturational competence (OMC). Cx32.2 RNA levels declined thereafter in all treatment groups, although this decline was not accompanied by the onset of germinal vesicle breakdown (GVBD) at the lowest hCG concentration used. The levels of Cx32.7 RNA initially declined and subsequently increased to preincubation values after hCG treatment, but these changes were not dependent on hCG concentration. In a separate experiment, the decline in Cx32.7 RNA occurred in the presence or absence of hCG and was prevented by low (physiological) concentrations of estradiol-17beta (E2) or by protein kinase C (PKC) inhibitor, but was enhanced in the presence of high E2 concentrations or of PKC activator. These changes in Cx32. 7 RNA abundance were not associated with any indices of oocyte maturation. In situ hybridization of tissue sections showed the presence of Cx32.2 and Cx32.7 RNA in somatic cells of the ovarian follicle but not in oocytes. Cx32.2 RNA seemed to be present in granulosa and thecal cells, but the assay resolution was insufficient to reliably determine the distribution of Cx32.7 transcript by somatic cell type. In view of earlier findings that Cx32.2-based (but not Cx32.7-based) connexons can form functional homotypic channels, these results indicate that Cx32.2 gene expression in granulosa cells is sufficient for the formation of homologous gap junctions (GJ). Northern blot of RNA extracts from ovulated eggs, which are free of follicle cells, showed the presence of relatively low levels of both Cx RNAs. Thus, it is possible that Cx32.2 is present in oocytes and that it participates in heterologous (homotypic) GJ formation between the oocyte and the granulosa cells. In conclusion, Cx32.2 RNA levels in somatic cells of the ovarian follicle correlated positively with morphological indices of OMC acquisition, but subsequently declined during GVBD. These changes in Cx32.2 RNA may function in the regulation of GJ contacts during follicular maturation.

The non-hydrolytic pathway of cystic fibrosis transmembrane conductance regulator ion channel gating

It has been suggested that the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel may utilize a novel gating mechanism in which open and closed states are not in thermodynamic equilibrium. This suggestion is based on the assumption that energy of ATP hydrolysis drives the gating cycle. We demonstrate that CFTR channel gating occurs in the absence of ATP hydrolysis and hence does not depend on an input of free energy from this source. The binding of ATP or structurally related analogues that are poorly or non-hydrolysable is sufficient to induce opening. Closing occurs on dissociation of these ligands or the hydrolysis products of those that can be cleaved. Not only can channel opening occur without ATP hydrolysis but the temperature dependence of the open probability (Po.) is reversed, i.e. Po. increases as temperature is lowered whereas under hydrolytic conditions, Po. increases as temperature is elevated. This indicates that there are different rate-limiting steps in the alternate gating pathways (hydrolytic and non-hydrolytic). These observations demonstrate that phosphorylated CFTR behaves as a conventional ligand-gated channel employing cytoplasmic ATP as a readily available cytoplasmic ligand; under physiological conditions ligand hydrolysis provides efficient reversibility of channel opening.

Changes of reliability and efficiency of micronucleus bioassay in Vicia faba after exposure to metal contamination for several generations

Mitotic root micronucleus (MCN) frequency in Vicia faba as a bioassay, is primarily based on the extent of the sentinel Vicia response in terms of cytogenetic damage quantitatively or qualitatively to indicate the presence of mutagenic contaminants. This paper describes an investigation designed to assess changes in MCN frequencies of Vicia faba from three generation plants obtained, respectively from a reference site (RS) and a metal-contaminated experimental field (EF) in the bioassay of mutagenic Cd(2+) and NaN(3). The background value, dose-response to Cd(2+) and to NaN(3) in three generation (F(1), F(2) and F(3)) plants of the EF and the initial (F(0)) plants were determined in terms of MCN frequencies. With more generations of growing Vicia plants in the EF, a higher background value of MCN frequency, a lower slope value in the regression equation, a smaller ratio of MCN frequency between the control and treatment in the same generation and larger perturbation values were observed. This denotes that the decreased reliability and efficiency are represented in Vicia plants from the EF if the plants are used as sentinels in the bioassay of mutagenic Cd(2+) and NaN(3). It was concluded that the Vicia MCN bioassay should be used as an endpoint biomarker acceptable in biomonitoring environmental mutagens when the sentinel plants were collected from clean areas. Because no place is absolutely without pollutants, it is suggested that several seed stock centers should be established for providing sentinel Vicia if Vicia MCN bioassay is used as a biomarker to identify the global environmental status.

Enteral nutrient intake level determines intestinal protein synthesis and accretion rates in neonatal pigs

Our objective was to determine the minimum enteral intake level necessary to increase the protein accretion rate (PAR) in the neonatal small intestine. Seven-day-old piglets received an equal total daily intake of an elemental diet, with different proportions given enterally (0, 10%, 20%, 40%, 60%, 80%, and 100%). After 7 days, piglets were infused intravenously with [(2)H(3)]leucine for 6 h, and the fractional protein synthesis rate (FSR) was measured in the proximal (PJ) and distal jejunum (DJ) and the proximal (PI) and distal ileum (DI). The jejunal FSR increased from 45%/day to 130%/day between 0 and 60% enteral intake, whereas the FSR in the ileum was less sensitive to enteral intake level. At 0% enteral intake, PAR was significantly negative in the PJ, DJ, and PI (range -70 to -43 mg/day) and positive in the DI (49 mg/day), whereas intestinal protein balance occurred at 20% enteral intake. At 100% enteral intake, the PAR was greatest in the DI, even though the rates of protein turnover were 50% lower than in the PJ. We conclude that there is net intestinal protein loss at 0% enteral intake, protein balance at 20% enteral intake, and maximal intestinal protein accretion at 60% enteral intake.

Dietary plasma protein is used more efficiently than extruded soy protein for lean tissue growth in early-weaned pigs

We compared the effects of supplementing either animal plasma or extruded soy protein in the diet based on the efficiency of dietary protein utilization for lean tissue growth in early-weaned pigs. Twenty-four 14-d-old pigs (4 kg body weight) were pair-fed (per kg body weight) either a control diet containing extruded soy protein (C; n = 12) or a diet with 10% animal plasma (P; n = 12) for 24 d. During the 24 days, protein intake was not different, yet mean daily body weight gains (+23%) and food conversion efficiencies (expressed as the ratio of body weight gain to protein intake) (+19%) were greater (P < 0.05) in the P group than in the C group. Lean body mass measured after 24 d, using both dual-energy X-ray absorptiometry and total body potassium analysis, was significantly (P < 0.05) greater (approximately 16%) in P than in C pigs. The circulating urea concentrations were 40% lower (P < 0.05) in P than in C pigs. Our results demonstrate that supplementing early-weaned pig diets with animal plasma rather than extruded soy protein increased the efficiency of dietary protein use for lean tissue growth and that this response is mediated in part by decreased amino acid catabolism.