Low-Temperature, Universal Synthetic Route for Mesoporous Metal Oxides by Exploiting Synergistic Effect of Thermal Activation and Plasma

Mesoporous metal oxides exhibit excellent physicochemical properties and are widely used in various fields, including energy storage/conversion, catalysis, and sensors. Although several soft-template approaches are reported, high-temperature calcination for both metal oxide formation and template removal is necessary, which limits direct synthesis on a plastic substrate for flexible devices. Here, a universal synthetic approach that combines thermal activation and oxygen plasma to synthesize diverse mesoporous metal oxides (V2O5, V6O13, TiO2, Nb2O5, WO3, and MoO3) at low temperatures (150-200 °C), which can be applicable to a flexible polymeric substrate is introduced. As a demonstration, a flexible micro-supercapacitor is fabricated by directly synthesizing mesoporous V2O5 on an indium-tin oxide-coated colorless polyimide film. The energy storage performance is well maintained under severe bending conditions.

Role of Oxygen in Amorphous Carbon Hard Mask Plasma Etching

In the current and next-generation Si-based semiconductor manufacturing processes, amorphous carbon layer (ACL) hard masks are garnering considerable attention for high-aspect-ratio (HAR) etching due to their outstanding physical properties. However, a current limitation is the lack of research on the etching characteristics of ACL hard masks under plasma etching conditions. Given the significant impact of hard mask etching on device quality and performance, a deeper understanding of the etching characteristics of ACL is necessary. This study aims to investigate the role of oxygen in the etching characteristics of an ACL hard mask in a complex gas mixture plasma etching process. Our results show that a small change of oxygen concentration (3.5-6.5%) can significantly alter the etch rate and profile of the ACL hard mask. Through our comprehensive plasma diagnostics and wafer-processing results, we have also proven a detailed mechanism for the role of the oxygen gas. This research provides a solution for achieving an outstanding etch profile in ACL hard masks with sub-micron scale and emphasizes the importance of controlling the oxygen concentration to optimize the plasma conditions for the desired etching characteristics.

Identification of epigenetic variation associated with synchronous pod maturity in mungbean (Vigna radiata L.)

Cytosine methylation in genomic DNA affects gene expression, potentially causing phenotypic variation. Mungbean, an agronomically and nutritionally important legume species, is characterized by nonsynchronous pod maturity, resulting in multiple harvest which costs extra time and labor. To elucidate the epigenetic influences on synchronous pod maturity (SPM) in mungbean, we determined the genome-wide DNA methylation profiles of eight mungbean recombinant inbred lines (RILs) and their parental genotypes, and compared DNA methylation profiles between high SPM and low SPM RILs, thus revealing differentially methylated regions (DMRs). A total of 3, 18, and 28 pure DMRs, defined as regions showing no significant correlation between nucleotide sequence variation and methylation level, were identified in CpG, CHG, and CHH contexts, respectively. These DMRs were proximal to 20 genes. Among the 544 single nucleotide polymorphisms identified near the 20 genes, only one caused critical change in gene expression by early termination. Analysis of these genome-wide DNA methylation profiles suggests that epigenetic changes can influence the expression of proximal genes, regardless of nucleotide sequence variation, and that SPM is mediated through gibberellin-mediated hormone signaling pathways. These results provide insights into how epialleles contribute to phenotypic variation and improve SPM in mungbean cultivars.

QTL Analysis of Resistance to High-Intensity UV-B Irradiation in Soybean (Glycine max [L.] Merr.)

High-intensity ultraviolet-B (UV-B) irradiation is a complex abiotic stressor resulting in excessive light exposure, heat, and dehydration, thereby affecting crop yields. In the present study, we identified quantitative trait loci (QTLs) for resistance to high-intensity UV-B irradiation in soybean (Glycine max [L.]). We used a genotyping-by-sequencing approach using an F6 recombinant inbred line (RIL) population derived from a cross between Cheongja 3 (UV-B sensitive) and Buseok (UV-B resistant). We evaluated the degree of leaf damage by high-intensity UV-B radiation in the RIL population and identified four QTLs, UVBR12-1, 6-1, 10-1, and 14-1, for UV-B stress resistance, together explaining 20% of the observed phenotypic variation. The genomic regions containing UVBR12-1 and UVBR6-1 and their syntenic blocks included other known biotic and abiotic stress-related QTLs. The QTL with the highest logarithm of odds (LOD) score of 3.76 was UVBR12-1 on Chromosome 12, containing two genes encoding spectrin beta chain, brain (SPTBN, Glyma.12g088600) and bZIP transcription factor21/TGACG motif-binding 9 (bZIP TF21/TGA9, Glyma.12g088700). Their amino acid sequences did not differ between the mapping parents, but both genes were significantly upregulated by UV-B stress in Buseok but not in Cheongja 3. Among five genes in UVBR6-1 on Chromosome 6, Glyma.06g319700 (encoding a leucine-rich repeat family protein) had two nonsynonymous single nucleotide polymorphisms differentiating the parental lines. Our findings offer powerful genetic resources for efficient and precise breeding programs aimed at developing resistant soybean cultivars to multiple stresses. Furthermore, functional validation of the candidate genes will improve our understanding of UV-B stress defense mechanisms.

Comprehensive RNA sequencing and co-expression network analysis to complete the biosynthetic pathway of coumestrol, a phytoestrogen

Coumestrol (CMS), a coumestan isoflavone, plays key roles in nodulation through communication with rhizobia, and has been used as phytoestrogens for hormone replacement therapy in humans. Because CMS content is controlled by multiple genetic factors, the genetic basis of CMS biosynthesis has remained unclear. We identified soybean genotypes with consistently high (Daewonkong) or low (SS0903-2B-21-1-2) CMS content over 2 years. We performed RNA sequencing of leaf samples from both genotypes at developmental stage R7, when CMS levels are highest. Within the phenylpropanoid biosynthetic pathway, 41 genes were tightly connected in a functional co-expression gene network; seven of these genes were differentially expressed between two genotypes. We identified 14 candidate genes involved in CMS biosynthesis. Among them, seven were annotated as encoding oxidoreductases that may catalyze the transfer of electrons from daidzein, a precursor of CMS. Two of the other genes, annotated as encoding a MYB domain protein and a MLP-like protein, may increase CMS accumulation in response to stress conditions. Our results will help to complete our understanding of the CMS biosynthetic pathway, and should facilitate development of soybean cultivars with high CMS content that could be used to promote the fitness of plants and human beings.

Transcriptomic variation in proanthocyanidin biosynthesis pathway genes in soybean (Glycine spp.)

BACKGROUND

Proanthocyanidins are oligomeric or polymeric end products of flavonoid metabolic pathways starting with the central phenylpropanoid pathway. Although soybean (Glycine spp.) seeds represent a major source of nutrients for the human diet, as well as components for the cosmetics industry as a result of their high levels of flavonoid metabolites, including isoflavonoids, anthocyanins and proanthocyanidins, the genetic regulatory mechanisms underlying proanthocyanidin biosynthesis in soybean remain unclear.

RESULTS

We evaluated interspecific and intraspecific variability in flavonoid components in soybean using 43 cultivars, landraces and wild soybean accessions. We performed transcriptomic profiling of genes encoding enzymes involved in flavonoid biosynthesis using three soybean genotypes, Hwangkeum (elite cultivar), IT109098 (landrace) and IT182932 (wild accession), in seeds. We identified a Glycine max landrace, IT109098, with a proanthocyanidin content as high as that of wild soybean. Different homologous genes for anthocyanidin reductase, which is involved in proanthocyanidin biosynthesis, were detected as differentially expressed genes between IT109098 and IT182932 compared to Hwangkeum.

CONCLUSION

We detected major differences in the transcriptional levels of genes involved in the biosynthesis of proanthocyanidin and anthocyanin among genotypes beginning at the early stage of seed development. The results of the present study provide insights into the underlying genetic variation in proanthocyanidin biosynthesis among soybean genotypes. © 2017 Society of Chemical Industry.

Predicting biochemical recurrence in patients with high-risk prostate cancer using the apparent diffusion coefficient of magnetic resonance imaging

Purpose

We aimed to investigate whether the apparent diffusion coefficient (ADC) value in diffusion-weighted magnetic resonance imaging predicts the prognoses of patients with high-risk prostate cancer.

Materials and Methods

A total of 157 patients with high-risk prostate cancer (based on D'Amico's criteria) were included in the analysis. Patients underwent preoperative 3.0 Tesla magnetic resonance imaging within 2 months before radical prostatectomy. Those who received neoadjuvant hormone therapy (33 persons) or radiation therapy (18 persons) were excluded. The ADC of the tumor calculated from 2 b-values (0 and 1,000 s/mm²) was measured. Areas under receiver operating characteristics curves were calculated to maximize the accuracy of the ADC value. Based on the obtained cutoff value, the patients were stratified into 2 groups: Group A consisted of patients with ADC values <746×10⁻⁶ mm²/s and group B comprised those with ADC values ≥746×10⁻⁶ mm²/s.

Results

Group A showed higher rate of lymph positive and biochemical recurrence (BCR) rates than group B. Kaplan-Meier analysis showed that the BCR-free survival rate of group A was much lower than that of group B (p<0.001). On Cox proportional regression analyses, ADC group A (hazard ratio [HR], 3.238, p=0.002) and pathologic lymph node positive (HR, 2.242; p=0.009) were independent predictors of BCR.

Conclusions

In patients with high-risk prostate cancer, ADC value is significantly associated with BCR-free survival. Therefore, the ADC value is a useful tool for predicting the prognoses of these high-risk patients.

Transcriptomic Profiling of Soybean in Response to High-Intensity UV-B Irradiation Reveals Stress Defense Signaling

The depletion of the ozone layer in the stratosphere has led to a dramatic spike in ultraviolet B (UV-B) intensity and increased UV-B light levels. The direct absorption of high-intensity UV-B induces complex abiotic stresses in plants, including excessive light exposure, heat, and dehydration. However, UV-B stress signaling mechanisms in plants including soybean (Glycine max [L.]) remain poorly understood. Here, we surveyed the overall transcriptional responses of two soybean genotypes, UV-B-sensitive Cheongja 3 and UV-B-resistant Buseok, to continuous UV-B irradiation for 0 (control), 0.5, and 6 h using RNA-seq analysis. Homology analysis using UV-B-related genes from Arabidopsis thaliana revealed differentially expressed genes (DEGs) likely involved in UV-B stress responses. Functional classification of the DEGs showed that the categories of immune response, stress defense signaling, and reactive oxygen species (ROS) metabolism were over-represented. UV-B-resistant Buseok utilized phosphatidic acid-dependent signaling pathways (based on subsequent reactions of phospholipase C and diacylglycerol kinase) rather than phospholipase D in response to UV-B exposure at high fluence rates, and genes involved in its downstream pathways, such as ABA signaling, mitogen-activated protein kinase cascades, and ROS overproduction, were upregulated in this genotype. In addition, the DEGs for TIR-NBS-LRR and heat shock proteins are positively activated. These results suggest that defense mechanisms against UV-B stress at high fluence rates are separate from the photomorphogenic responses utilized by plants to adapt to low-level UV light. Our study provides valuable information for deep understanding of UV-B stress defense mechanisms and for the development of resistant soybean genotypes that survive under high-intensity UV-B stress.

Pathological T3a Upstaging of Clinical T1 Renal Cell Carcinoma: Outcomes According to Surgical Technique and Predictors of Upstaging

Purpose

To evaluate the prognosis of pT3a upstaging from cT1 renal cell carcinoma, and to compare the outcomes of partial or radical nephrectomy in cases of pT3a upstaging.

Materials and Methods

We reviewed the records of patients who underwent partial or radical nephrectomy for cT1 at our center between January 2001 and October 2013. We compared the 2-year recurrence-free survivals for cases with pT1 or pT3a upstaging, and for partial or radical nephrectomy in cases with pT3a upstaging. Clinicopathological parameters were analyzed in univariate and multivariate analyses to evaluate their associations with upstaging.

Results

Among the 1,009 eligible patients, 987 patients were included in the analysis. The mean follow-up was 48.5 ± 27.8 months in whole patients. The 2-year recurrence-free survival was worse in the pT3a upstaging group, compared to the pT1 group (87.3% vs. 98.7%; p < 0.001). Partial nephrectomy and radical nephrectomy had no significant difference in 2-year recurrence-free survivals (91.9% vs. 83.7%; p = 0.251). The multivariate analysis revealed that upstaging was associated with old age, cT1b stage, clinical symptoms, and a high Fuhrman grade.

Conclusions

Pathological T3a upstaging of cT1 renal cell carcinoma was associated with a poorer prognosis, compared to pT1 disease. However, the surgical technique (radical or partial nephrectomy) did not affect the recurrence rate. Therefore, clinicians should select the treatment method based on the clinical stage, and consider the pathological stage during the follow-up.

Optimization of a Virus-Induced Gene Silencing System with Soybean yellow common mosaic virus for Gene Function Studies in Soybeans

Virus-induced gene silencing (VIGS) is an effective tool for the study of soybean gene function. Successful VIGS depends on the interaction between virus spread and plant growth, which can be influenced by environmental conditions. Recently, we developed a new VIGS system derived from the Soybean yellow common mosaic virus (SYCMV). Here, we investigated several environmental and developmental factors to improve the efficiency of a SYCMV-based VIGS system to optimize the functional analysis of the soybean. Following SYCMV: Glycine max-phytoene desaturase (GmPDS) infiltration, we investigated the effect of photoperiod, inoculation time, concentration of Agrobacterium inoculm, and growth temperature on VIGS efficiency. In addition, the relative expression of GmPDS between non-silenced and silenced plants was measured by qRT-PCR. We found that gene silencing efficiency was highest at a photoperiod of 16/8 h (light/dark) at a growth temperature of approximately 27°C following syringe infiltration to unrolled unifoliolate leaves in cotyledon stage with a final SYCMV:GmPDS optimal density (OD)600 of 2.0. Using this optimized protocol, we achieved high efficiency of GmPDS-silencing in various soybean germplasms including cultivated and wild soybeans. We also confirmed that VIGS occurred in the entire plant, including the root, stem, leaves, and flowers, and could transmit GmPDS to other soybean germplasms via mechanical inoculation. This optimized protocol using a SYCMV-based VIGS system in the soybean should provide a fast and effective method to elucidate gene functions and for use in large-scale screening experiments.

Genome sequence of mungbean and insights into evolution within Vigna species

Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. Here we construct a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis, which includes several important dietary legumes in Asia, and to enable a better understanding of the evolution of leguminous species. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (V. reflexo-pilosa var. glabra) provides genomic evidence of a recent allopolyploid event. The species tree is constructed using de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.

Genome-wide mapping of NBS-LRR genes and their association with disease resistance in soybean

BACKGROUND

R genes are a key component of genetic interactions between plants and biotrophic bacteria and are known to regulate resistance against bacterial invasion. The most common R proteins contain a nucleotide-binding site and a leucine-rich repeat (NBS-LRR) domain. Some NBS-LRR genes in the soybean genome have also been reported to function in disease resistance. In this study, the number of NBS-LRR genes was found to correlate with the number of disease resistance quantitative trait loci (QTL) that flank these genes in each chromosome. NBS-LRR genes co-localized with disease resistance QTL. The study also addressed the functional redundancy of disease resistance on recently duplicated regions that harbor NBS-LRR genes and NBS-LRR gene expression in the bacterial leaf pustule (BLP)-induced soybean transcriptome.

RESULTS

A total of 319 genes were determined to be putative NBS-LRR genes in the soybean genome. The number of NBS-LRR genes on each chromosome was highly correlated with the number of disease resistance QTL in the 2-Mb flanking regions of NBS-LRR genes. In addition, the recently duplicated regions contained duplicated NBS-LRR genes and duplicated disease resistance QTL, and possessed either an uneven or even number of NBS-LRR genes on each side. The significant difference in NBS-LRR gene expression between a resistant near-isogenic line (NIL) and a susceptible NIL after inoculation of Xanthomonas axonopodis pv. glycines supports the conjecture that NBS-LRR genes have disease resistance functions in the soybean genome.

CONCLUSIONS

The number of NBS-LRR genes and disease resistance QTL in the 2-Mb flanking regions of each chromosome was significantly correlated, and several recently duplicated regions that contain NBS-LRR genes harbored disease resistance QTL for both sides. In addition, NBS-LRR gene expression was significantly different between the BLP-resistant NIL and the BLP-susceptible NIL in response to bacterial infection. From these observations, NBS-LRR genes are suggested to contribute to disease resistance in soybean. Moreover, we propose models for how NBS-LRR genes were duplicated, and apply Ks values for each NBS-LRR gene cluster.

RNA-Seq analysis of a soybean near-isogenic line carrying bacterial leaf pustule-resistant and -susceptible alleles

Bacterial leaf pustule (BLP) disease is caused by Xanthomonas axonopodis pv. glycines (Xag). To investigate the plant basal defence mechanisms induced in response to Xag, differential gene expression in near-isogenic lines (NILs) of BLP-susceptible and BLP-resistant soybean was analysed by RNA-Seq. Of a total of 46 367 genes that were mapped to soybean genome reference sequences, 1978 and 783 genes were found to be up- and down-regulated, respectively, in the BLP-resistant NIL relative to the BLP-susceptible NIL at 0, 6, and 12h after inoculation (hai). Clustering analysis revealed that these genes could be grouped into 10 clusters with different expression patterns. Functional annotation based on gene ontology (GO) categories was carried out. Among the putative soybean defence response genes identified (GO:0006952), 134 exhibited significant differences in expression between the BLP-resistant and -susceptible NILs. In particular, pathogen-associated molecular pattern (PAMP) and damage-associated molecular pattern (DAMP) receptors and the genes induced by these receptors were highly expressed at 0 hai in the BLP-resistant NIL. Additionally, pathogenesis-related (PR)-1 and -14 were highly expressed at 0 hai, and PR-3, -6, and -12 were highly expressed at 12 hai. There were also significant differences in the expression of the core JA-signalling components MYC2 and JASMONATE ZIM-motif. These results indicate that powerful basal defence mechanisms involved in the recognition of PAMPs or DAMPs and a high level of accumulation of defence-related gene products may contribute to BLP resistance in soybean.

Anti-inflammatory effect of germanium-concentrated yeast against paw oedema is related to the inhibition of arachidonic acid release and prostaglandin E production in RBL 2H3 cells

1 To investigate anti-inflammatory activity of organic germanium, we measured the effect of germanium-concentrated yeast on arachidonic acid release, prostaglandin E(2) (PGE(2)) production, histamine release, and intracellular H(2)O(2) or hydroperoxide generation in RBL 2H3 cells, and carrageenan-induced paw oedema in rats. 2 Germanium-concentrated yeast dose-dependently inhibited carrageenan-induced paw oedema, suggesting that germanium-concentrated yeast has anti-inflammatory activity in acute inflammation. 3 Germanium-concentrated yeast significantly inhibited melittin-induced arachidonic acid release and PGE(2) production in RBL 2H3 cells. 4 Germanium-concentrated yeast did not affect melittin-induced histamine release and silica-induced intracellular H(2)O(2) or hydroperoxide generation in RBL 2H3 cells. 5 These results suggest that anti-inflammatory activity of germanium-concentrated yeast appears partly to be related to the inhibition of arachidonic acid release and PGE(2) production in RBL 2H3 cells.

Effects of stimulation of AMP-activated protein kinase on insulin-like growth factor 1- and epidermal growth factor-dependent extracellular signal-regulated kinase pathway

AMP-activated protein kinase (AMPK) is tightly regulated by the cellular AMP:ATP ratio and plays a central role in the regulation of energy homeostasis. Previously, AMPK was reported to phosphorylate serine 621 of Raf-1 in vitro. In the present study, we investigated a possible role of AMPK in extracellular signal-regulated kinase (Erk) cascades, using 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR), a cell-permeable activator of AMPK and antisense RNA experiments. Activation of AMPK by AICAR in NIH-3T3 cells resulted in drastic inhibitions of Ras, Raf-1, and Erk activation induced by insulin-like growth factor 1 (IGF-1). Expression of an antisense RNA for the AMPK catalytic subunit decreased the AMPK activity and significantly diminished the AICAR effect on IGF-1-induced Ras activation and the subsequent Erk activation, indicating that its effect is indeed mediated by AMPK. Phosphorylation of Raf-1 serine 621, however, was not involved in AMPK-mediated inhibition of Erk cascades. In contrast to IGF-1, AICAR did not block epidermal growth factor (EGF)-dependent Raf-1 and Erk activation, but our results demonstrated that multiple Raf-1 upstream pathways induced by EGF were differentially affected by AICAR: inhibition of Ras activation and simultaneous induction of Ras-independent Raf activation. The activities of IGF-1 and EGF receptor were not affected by AICAR. Taken together, our results suggest that AMPK differentially regulate Erk cascades by inhibiting Ras activation or stimulating the Ras-independent pathway in response to the varying energy status of the cell.

Roles of histidine residues in tobacco acetolactate synthase

Acetolactate synthase (ALS) catalyzes the first common step in the biosynthesis of valine, leucine, and isoleucine in plants and microorganisms. ALS is the target of several structurally diverse classes of herbicides, including sulfonylureas, imidazolinones, and triazolopyrimidines. The roles of three well-conserved histidine residues (H351, H392, and H487) in tobacco ALS were determined using site-directed mutagenesis. Both H487F and H487L mutations abolished the enzymatic activity as well as the binding affinity for the cofactor FAD. Nevertheless, the mutation of H487F did not affect the secondary structure of the ALS. The K(m) values of H351M, H351Q, and H351F are approximately 18-, 60-, and fivefold higher than that of the wild-type ALS, respectively. Moreover, the K(c) value of H351Q for FAD is about 137-fold higher than that of wALS. Mutants H351M and H351Q showed very strong resistance to Londax (a sulfonylurea) and Cadre (an imidazolinone), whereas mutant H351F was weakly resistant to them. However, the secondary structures of mutants H351M and H351Q appeared to be different from that of wALS. The mutation of H392M did not have any significant effect on the kinetic parameters nor the resistance to ALS-inhibiting herbicides. These results suggest that the His487 residue is located at the active site of the enzyme and is likely involved in the binding of cofactor FAD in tobacco ALS. Mutational analyses of the His351 residue imply that the active site of the ALS is probably close to its binding site of the herbicides, Londax and Cadre.

Phosphatidylinositol 3-kinase regulates differentiation of H9c2 cardiomyoblasts mainly through the protein kinase B/Akt-independent pathway

Phosphatidylinositol 3-kinase (PI3-kinase) is known to be a crucial regulator of muscle differentiation. However, its downstream pathway for this function is quite obscure. In this experiment we demonstrated the regulatory mechanism of the differentiation of H9c2 cardiomyoblasts, focusing on PI3-kinase, protein kinase B/Akt (PKB/Akt) and p42/44 mitogen-activated protein kinase (p42/44 MAPK). When H9c2 cells stably transfected with a constitutively active p110 (H9c2-p110*), a constitutively active PKB/Akt (H9c2-Akt), and an empty vector (H9c2-con) were induced to differentiate, H9c2-p110* cells differentiated fastest, followed by H9c2-Akt cells. H9c2-con cells differentiated at the slowest rate. Consistent with this result, LY294002 completely blocked differentiation of all these transfected cell lines, whereas PD098059 had no effect on their differentiation. When H9c2-p110* cells were transiently transfected with a dominant negative form of PKB/Akt, differentiation was not affected. Taken together, we concluded that PI3-kinase, but not p42/44 MAPK, regulates differentiation of H9c2 cardiomyoblasts mainly through the PKB/Akt-independent pathway.

Hypothermia does not result in more complications after colon surgery

Our objective was to determine the incidence of complications in postoperative patients who were either normothermic or hypothermic. A recent, widely publicized paper concluded that the maintenance of normothermia could reduce the incidence of infectious complications and shorten hospitalization in patients undergoing colorectal surgery. However, some controversy arose regarding the methods of this paper. Patients were deliberately rendered hypothermic, were given more than 3.5 days of prophylactic antibiotics and were transfused significantly more units of blood. We reviewed the charts of 150 consecutive patients who underwent elective partial or subtotal colectomy with primary anastomosis. Among the key items analyzed were intraoperative and postoperative temperature, use of warming devices, duration of surgery, transfusions, interval to oral intake and bowel function, length of stay, complications, infections, and laboratory values. Hypothermia was defined as intraoperative temperature <95.5 degrees F. There were 101 normothermic patients and 49 hypothermic patients. Hypothermic patients had a mean age of 68.7 years versus 66.8 for the normothermic patients (P = 0.472). Comorbidities were similar in both groups. Warming devices were used in >90 per cent of the patients in both groups. The rates of postoperative infections and complications were similar in both groups. Postoperative lengths of stay were also not different. Despite finding that one-third of our patients were hypothermic during elective colon resection, hypothermia had no effect on outcome variables. In contrast to the previous study, the incidence of infectious complications was identical in our patients. Before ascribing postoperative complications and increased resource utilization as adverse effects of hypothermia, further studies are indicated.

Effect of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'- dicarboxylate (DDB) on chemical-induced liver injury

The effects of orally administered dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene-dioxybiphenyl-2,2'-d icarboxylate (DDB) on the hepatotoxicity induced by carbon tetrachloride, acetaminophen or ethanol were investigated in rats and mice. Either single or repeated DDB pretreatment (50 or 200 mg/kg) did not alter the hepatotoxicity induced by carbon tetrachloride (0.2 or 1.0 ml/kg, i.p.) in female rats as indicated by increases in the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) in serum. The hepatotoxicity of acetaminophen (350 mg/kg, i.p.) was also unaffected in male mice pretreated with DDB (50 mg/kg/d) for a week. However, DDB administration (50 mg/kg/d for 7 d) decreased the hepatic fatty degeneration induced by repeated ethanol treatment (0.75 g/kg, i.p., x2 times a day for a week) in rats as shown by the accumulation of triglycerides and cholesterol in the liver. Malondialdehyde (MDA) formation in liver homogenates was inhibited by DDB treatment. The significance of the action of DDB on alcoholic fatty liver generation in clinical settings is discussed.

Cysteine 42 is important for maintaining an integral active site for O-acetylserine sulfhydrylase resulting in the stabilization of the alpha-aminoacrylate intermediate

O-Acetylserine sulfhydrylase-A (OASS-A) is a pyridoxal 5'-phosphate (PLP) dependent enzyme from Salmonella typhimurium that catalyzes the beta-replacement of acetate in O-acetyl-L-serine (OAS) by sulfide to give L-cysteine. The reaction occurs via a ping-pong kinetic mechanism in which alpha-aminoacrylate in Schiff base with the active site PLP is an intermediate [Cook, P. F., Hara, S., Nalabolu, S. R., and Schnackerz, K. D. (1992) Biochemistry 31, 2298-2303]. The sequence around the Schiff base lysine (K41) has been determined [Rege, V. D., Kredich, N. M., Tai, C.-H., Karsten, W. E., Schnackerz, K. D., & Cook, P. F. (1996) Biochemistry 35, 13485-13493], and the sole cysteine in the primary structure is immediately C-terminal to the lysine. In an effort to assess the role of C42, it has been changed to serine and alanine by site-directed mutagenesis. The mutant proteins are structurally nearly identical to the wild-type enzyme on the basis of UV-visible, fluorescence, far-UV and cofactor-induced CD, and 31P NMR studies, but subtle structural differences are noted. Kinetic properties of both mutant proteins differ significantly from those of the wild-type enzyme. The C42S mutant exhibits a > 50-fold increase in the OAS:acetate lyase activity and a 17-fold decrease in V for the cysteine synthesis compared to the wild-type enzyme, while decreases of > 200-fold in the OAS: acetate lyase activity and a 30-fold decrease in V for the cysteine synthesis are found for the C42A mutant enzyme. In both cases, however, the pH dependence of kinetic parameters for cysteine synthesis and OAS: acetate lyase activity yield, within error, identical pK values. In the three-dimensional structure of OASS-A, cysteine 42 is located behind the cofactor, pointing away from the active site, toward the interior of the protein. The dramatic change in the OAS:acetate lyase activity of OASS-A in the C42S and C42A mutant proteins likely results from a localized movement of the serine hydroxyl (compared to the cysteine thiol) toward additional hydrophilic, hydrogen-bonding groups in C42S, or away from hydrophilic groups for C42A, repositioning structure around and including K41. Subtle movement of the epsilon-amino group of K41 may change the geometry for nucleophilic displacement of the amino acid from PLP, leading to changes in overall activity and stability of the alpha-aminoacrylate intermediate. Data indicate that single amino acid substitutions that yield only subtle changes in structure can produce large differences in reaction rates and overall mechanism.

Insulin has a limited effect on the cell cycle progression in 3T3 L1 fibroblasts

Insulin has pleiotropic effects on the regulation of cellular growth, differentiation, and metabolism. The biochemical events ultimately leading to cell proliferation after insulin treatment have been demonstrated in detail by numerous research groups. However, depending on cell types, it has been shown that insulin has various effects on cell proliferation. Therefore, we attempted to more critically evaluate the effect of insulin on cell proliferation in 3T3 L1 fibroblasts. In this study, we investigated insulin's effect on cell proliferation by using [3H]thymidine incorporation, flow cytometry, and cell counting. In 3T3 L1 fibroblasts studied in 0.5% serum, insulin induced a two-fold increase in [3H]thymidine incorporation over at 48 h, and the maximal rate of DNA synthesis was observed during 8-12 h incubation. The flow cytometric analysis also showed that insulin increased the cell population in the S phase. After insulin treatment for 48 h, cell numbers increased approximately 45% in comparison with 0.5% serum control. Cell division was found to occur only once in 60 h after staining 3T3 L1 fibroblasts with carboxyfluorescein diacetate succinimidyl ester (CFSE). Taken together, this data indicates that insulin stimulated the transit from the G0/G1 to S phase, progressed the cell cycle through the G2/M phase, and increased the cell number. However, under our experimental conditions, cells divided only once in 60 h in the presence of insulin.

Potentiation of acetaminophen hepatotoxicity by acute physical exercise in rats

Effects of acute physical exercise on the acetaminophen-induced hepatotoxicity were examined in adult female rats. Rats were forced to move at a speed of 10 m/min for 2 hr in a rotating cage. Immediately following the exercise bout rats were treated with acetaminophen (APAP; 700 mg/kg, i.p.). The physical exercise enhanced the hepatotoxicity of APAP as shown by increases in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities measured 24 hr following the treatment. A significant decrease in hepatic glutathione (GSH) was observed in the rats forced to exercise suggesting that the enhancement of APAP hepatotoxicity was associated with the depression of this endogenous tripeptide. The role of adrenergic stimulation in the exercise-induced hepatic GSH depression was examined by pretreating the animals with a receptor specific adrenergic antagonist, such as prazosin HCl (15 mg/kg, i.p.), propranolol HCl (15 mg/kg, i.p.), and yohimbine HCl (15 mg/kg, i.p.) 15 min prior to the exercise bout, but neither of the antagonists prevented the GSH depression. Administration of alpha-tocopherol acetate (450 mg/kg/day for 3 days and 150 mg/kg on day 4, i.p.) did not affect the exercise-induced GSH depression or lipid peroxidation in liver homogenates as determined by increases in malondialdehyde formation. These results suggest that neither adrenergic stimulation nor oxidative stress plays a significant role in the enhancement of APAP hepatotoxicity and hepatic GSH depression induced by acute physical exercise.

Enhancement of mitogen-stimulated proliferation of low dose radiation-adapted mouse splenocytes

We have monitored mitogen-stimulated mouse splenocyte proliferation as a biological end point of radiation damages to access adaptive response to ionizing radiation. When cells were pre-exposed to an adapting dose of 0. 01 Gy of low dose gamma-ray 4, 7, and 20 hours prior to an acute challenging dose of 2 Gy, most significant enhancement in splenocyte proliferation was induced at 4 hour interval. When the challenging high dose was varied, an adaptive response was observed at up to 4 Gy of high dose gamma-ray challenge. Gamma-ray-irradiated mouse splenocyte showed characteristic morphology of apoptotic cells. The extent of DNA fragmentation, another characteristic of apoptotic cells, was also reduced in low dose gamma-ray-adapted cells. The addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazol (DRFB), respectively during adaptation period, the period between low and high dose irradiations, were able to inhibit the induction of adaptive response. These data suggest that to induce adaptive response to ionizing radiation in mouse splenocytes, both protein and RNA synthesis are required.

Acid-base chemical mechanism of aspartase from Hafnia alvei

An acid-base chemical mechanism is proposed for Hafnia alvei aspartase in which a proton is abstracted from C-3 of the monoanionic form of L-aspartate by an enzyme general base with a pK of 6.3-6.6 in the absence and presence of Mg2+. The resulting carbanion is presumably stabilized by delocalization of electrons into the beta-carboxyl with the assistance of a protonated enzyme group in the vicinity of the beta-carboxyl. Ammonia is then expelled with the assistance of a general acid group that traps an initially expelled NH3 as the final NH4+ product. In agreement with the function of the general acid group, potassium, an analog of NH4+, binds optimally when the group is unprotonated. The pK for the general acid is about 7 in the absence of Mg2+, but is increased by about a pH unit in the presence of Mg2+. Since the same pK values are observed in the pKi(succinate) and V/K pH profile, both enzyme groups must be in their optimum protonation state for efficient binding of reactant in the presence of Mg2+. At the end of a catalytic cycle, both the general base and general acid groups are in a protonation state opposite that in which they started when aspartate was bound. The presence of Mg2+ causes a pH-dependent activation of aspartase exhibited as a partial change in the V and V/Kasp pH profiles. When the aspartase reaction is run in D2O to greater than 50% completion no deuterium is found in the remaining aspartate, indicating that the site is inaccessible to solvent during the catalytic cycle.

Linkage mapping of 40 randomly isolated liver cDNA clones in the mouse

We report the chromosomal mapping of 43 loci for 40 randomly isolated mouse liver cDNA clones by linkage analysis in an interspecific backcross of ((C57BL/6J x Mus spretus) x C57BL/6J). The clones were sequenced from both sides and a subset was examined for expression in various mouse tissues. Fifteen of the 40 mapped cDNA clones are either identical or strongly related to known sequences in GenBank, while 25 represent new genes. Additional loci mapped in this cross include 53 simple sequence repeat polymorphisms and 40 restriction fragment length variants from previously characterized cDNA markers. Nine homologous human genes were identified for 7 mouse liver cDNA clones. One clone that maps to mouse chromosome 3 (D3Ucla1) identified a novel homologous segment (synteny) on human chromosome 18q23 (D18S372E). These studies provide linkage mapping and initial characterization of random cDNA clones that may provide a resource for the positional candidate cloning of disease genes.

Chromosomal localization of lipolytic enzymes in the mouse: pancreatic lipase, colipase, hormone-sensitive lipase, hepatic lipase, and carboxyl ester lipase

Several lipases and their cofactors are involved in the absorption, transport, storage, and mobilization of lipids. As part of an effort to examine the role of these enzymes in plasma lipid metabolism and genetic susceptibility to atherosclerosis, we report the chromosomal mapping of their genes in mouse. Restriction fragment length variants for each gene were identified, typed in an interspecific cross, and tested for linkage to known chromosomal markers. The gene for pancreatic lipase resides on chromosome 19, while the gene for its cofactor, colipase, is on chromosome 17. A gene for a protein with sequence similarity to pancreatic lipase was tightly linked (no observed recombination) to the gene for pancreatic lipase, suggesting a gene cluster. The gene for hormone-sensitive lipase is near the gene cluster containing apolipoproteins C-II and E on chromosome 7. The gene for hepatic lipase is near the gene for apolipoprotein A-I on chromosome 9. The carboxyl ester lipase gene resides on chromosome 2. Previously, we have mapped the gene for lipoprotein lipase to chromosome 8. Thus, with the exception of pancreatic lipase and a related protein, these lipase genes, including several that are members of a gene family, are widely dispersed in the genome. Comparison of chromosomal locations for these genes in mouse and humans shows that the previously observed interspecies syntenies are preserved.

Product dependence of deuterium isotope effects in enzyme-catalyzed reactions

Theory for enzyme-catalyzed reactions is developed for the dependence on product concentration of deuterium isotope effects on V and V/K. Generally, a product that decreases the off-rate for a second product to zero causes the isotope effect on V/K to decrease to DKeq and that on V to decrease to a value between 1 and DKeq. If the second product off-rate is decreased to a finite value, DV and D(V/K) will decrease to a value greater than DKeq, while if there is no effect on the off-rate for the second product, DV and D(V/K) will not change. Interestingly, for a ping-pong mechanism, the presence of the product that provides a reversible connection between the isotope-sensitive step and the isotope-insensitive half-reaction will give an isotope effect on V/K for the latter. (In the absence of the product, the isotope effect on V/K for the isotope-insensitive half-reaction will be unity.) Theory is supported with data for alcohol and lactate dehydrogenases. For lactate dehydrogenase, D(V/Kpyruvate) decreases from 1.93 +/- 0.02 at zero to 1.16 +/- 0.02 at infinite lactate concentration, while DV decreases from a value of 1.75 +/- 0.03 at zero to a value of 0.93 +/- 0.05 at infinite lactate concentration. Thus, it appears that the pathway in which lactate is released first is greatly preferred, but the pathway in which NAD+ is released before lactate is observed at high lactate concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetic mechanism of the adenosine 3',5'-monophosphate dependent protein kinase catalytic subunit in the direction of magnesium adenosine 5'-diphosphate phosphorylation

In order to define the overall kinetic mechanism of adenosine 3',5'-monophosphate dependent protein kinase catalytic subunit and also to elaborate the kinetic mechanism in the direction of peptide phosphorylation, we have determined its kinetic mechanism in the direction of MgADP phosphorylation. Studies of initial velocity as a function of uncomplexed Mg2+ (Mgf) in the absence and presence of dead-end inhibitors were used to define the kinetic mechanism. Data are consistent with the overall kinetic mechanism in the direction of MgADP phosphorylation being random with both the pathways allowed, i.e., the pathway in which MgADP binds to the enzyme prior to phosphorylated peptide and the pathway in which phosphorylated peptide binds to enzyme prior to MgADP. In addition, depending on the concentration of Mgf, one or the other pathway predominates. At low (0.5 mM) Mgf, the mechanism is steady-state ordered with the pathway in which phosphorylated peptide binds first being preferred; at high (10 mM) Mgf, the kinetic mechanism is equilibrium ordered, and the pathway in which MgADP binds first is preferred. This change in mechanism to equilibrium ordered at higher concentration of Mgf is due to an increase in affinity of the enzyme for MgADP and a decrease in affinity for the phosphorylated peptide. The Haldane relationship gives a Keq of 2 +/- 1 x 10(3) at pH 7.2, in agreement with the values obtained from 31P NMR (1.6 +/- 0.8 x 10(3)) and direct determination of reactant concentrations at equilibrium (3.5 +/- 0.6 x 10(3)).

Identification and localization of talin in chick retinal pigment epithelial cells

Retinal pigmented epithelial cells are adherent at their basal surface to Bruch's membrane and at their apical surface to the neural retina. We examined the expression and distribution of two proteins that are found in regions of cell-matrix interaction, talin and integrin. Talin is a 235-kDa cytoplasmic protein that has been localized to regions of cell-substrate adhesion. It binds to both integrin, a transmembrane glycoprotein complex, and to vinculin, a cytoskeletal protein. In the present study, we produced a polyclonal antibody to chicken gizzard talin. Using this antibody we showed by western blot analysis that talin is expressed by RPE cells and is found in the triton-soluble fraction. Talin was shown to co-localize with integrin and vinculin in the basal region of chick RPE cells isolated from 18-day-old chick embryos. Neither talin nor integrin was found in the apical processes or in the zonula adherens. Antibodies to vinculin showed staining both in the apical and basal regions of the RPE cells. The localization of integrin, talin and vinculin along the basal membrane suggests that this complex is important in the attachment of the RPE cells to the basement membrane. The distribution of integrin and talin was examined in primary cultures of RPE cells grown on permeable filters. In these cells, a polarized distribution of integrin and talin was not observed. This may suggest that the neural retina may be important for maintaining the differentiated state of the RPE cells.

Chemical mechanism of the adenosine cyclic 3',5'-monophosphate dependent protein kinase from pH studies

The pH dependence of kinetic parameters and inhibitor dissociation constants for the adenosine cyclic 3',5'-monophosphate dependent protein kinase reaction has been determined. Data are consistent with a mechanism in which reactants selectively bind to enzyme with the catalytic base unprotonated and an enzyme group required protonated for peptide (Leu-Arg-Arg-Ala-Ser-Leu-Gly) binding. Binding of the peptide apparently locks both of the above enzyme residues in their correct protonation state. MgATP preferentially binds fully ionized and requires an enzyme residue (probably lysine) to be protonated. The maximum velocity and V/KMgATP are pH independent. The V/K for Ser-peptide is bell-shaped with pK values of 6.2 and 8.5 estimated. The pH dependence of 1/Ki for Leu-Arg-Arg-Ala-Ala-Leu-Gly is also bell-shaped, giving pK values identical with those obtained for V/KSer-peptide, while the Ki for MgAMP-PCP increases from a constant value of 650 microM above pH 8 to a constant value of 4 mM below pH 5.5. The Ki for uncomplexed Mg2+ obtained from the Mg2+ dependence of V and V/KMgATP is apparently pH independent.