Lifetime correction of genetic deficiency in mice with a single injection of helper-dependent adenoviral vector

Ideally, somatic gene therapy should result in lifetime reversal of genetic deficiencies. However, to date, phenotypic correction of monogenic hyperlipidemia in mouse models by in vivo gene therapy has been short-lived and associated with substantial toxicity. We have developed a helper-dependent adenoviral vector (HD-Ad) containing the apolipoprotein (apo) E gene. A single i.v. injection of this vector completely and stably corrected the hypercholesterolemia in apoE-deficient mice, an effect that lasted the natural lifespan of the mice. At 2.5 years, control aorta was covered 100% by atherosclerotic lesion, whereas aorta of treated mice was essentially lesion-free. There was negligible toxicity associated with the treatment. We also developed a method for repeated HD-Ad vector administration that could be applied to organisms, e.g., humans, with life spans longer than 2-3 years. These studies indicate that HD-Ad is a promising system for liver-directed gene therapy of metabolic diseases.

Distinct physiological functions of thiol peroxidase isoenzymes in Saccharomyces cerevisiae

A new type of peroxidase ("thiol peroxidase"; TPx) having cysteine as the primary site of catalysis has been discovered from prokaryotes to eukaryotes. In addition to two yeast TPx isoforms (TSA I and TSA II/AHPC1) previously described, three additional TPx homologues were identified by analysis of the open reading frame data base for Saccharomyces cerevisiae. Three novel isoforms showed a distinct thiol peroxidase activity supported by thioredoxin, and appeared to be distinctively localized in cytoplasm, mitochondria, and nucleus. Each isoform was named after its subcellular localization such as cytoplasmic TPx I (cTPx I or TSA I), cTPx II, cTPx III (TSA II/AHPC1), mitochondrial TPx (mTPx), and nuclear TPx (nTPx). Their transcriptional activities suggest that cTPx I and cTPx III are the most predominant isoforms among the five type isoforms. Transcriptional activities of TPx isoenzymes during yeast life span were quite different from each other. Unlike other TPx null mutants, cTPx I null mutant was hypersensitive to various oxidants except for 4-nitroquinoline N-oxide. The null mutant was more resistant toward 4-nitroquinoline N-oxide and acidic culture than its wild type. The severe growth retardation of cTPx II mutant resulted in accumulation of G(1)-phased cells. Based on kinetic properties of five isoforms, their subcellular localizations, and distinct physiology of each null mutant, we discussed the physiological functions of five types of TPx isoenzymes in yeast throughout the full growth cycle.

Thioredoxin-dependent hydroperoxide peroxidase activity of bacterioferritin comigratory protein (BCP) as a new member of the thiol-specific antioxidant protein (TSA)/Alkyl hydroperoxide peroxidase C (AhpC) family

Escherichia coli bacterioferritin comigratory protein (BCP), a putative bacterial member of the TSA/AhpC family, was characterized as a thiol peroxidase. BCP showed a thioredoxin-dependent thiol peroxidase activity. BCP preferentially reduced linoleic acid hydroperoxide rather than H(2)O(2) and t-butyl hydroperoxide with the use of thioredoxin as an in vivo immediate electron donor. The value of V(max)/K(m) of BCP for linoleic acid hydroperoxide was calculated to be 5-fold higher than that for H(2)O(2), implying that BCP has a selective capability to reduce linoleic acid hydroperoxide. Replacement of Cys-45 with serine resulted in the complete loss of thiol peroxidase activity, suggesting that BCP is a new bacterial member of TSA/AhpC family having a conserved cysteine as the primary site of catalysis. BCP exists as a monomer, and its functional Cys-45 appeared to exist as cysteine sulfenic acid. The expression level of BCP gradually elevated during exponential growth until mid-log phase growth, beyond which the expression level was decreased. BCP was induced 3-fold by the oxidative stress given by changing the growth conditions from the anaerobic to aerobic culture. Bcp null mutant grew more slowly than its wild type in aerobic culture and showed the hypersensitivity toward various oxidants such as H(2)O(2), t-butyl hydroperoxide, and linoleic acid hydroperoxide. The peroxide hypersensitivity of the null mutant could be complemented by the expression of bcp gene. Taken together, these data suggest that BCP is a new member of thioredoxin-dependent TSA/AhpC family, acting as a general hydroperoxide peroxidase.

Removals of hydrogen peroxide and hydroxyl radical by thiol-specific antioxidant protein as a possible role in vivo

Thiol-specific antioxidant protein (Protector Protein; PRP) from Saccharomyces cerevisiae was found to remove hydrogen peroxide and hydroxyl radical in the presence of dithiothreitol (DTT). Without DTT as a reducing equivalent, the antioxidant protein did not show the activities for destroying hydrogen peroxide and hydroxyl radical. N-ethylmaleimide (NEM) was observed to prevent the PRP from both removing hydrogen peroxide and protecting the cleavage of DNA. These observations suggest that the sulfhydryl of cysteine in PRP could function as a strong nucleophile to attack and destroy H2O2 and .OH.

Effect of Bacillus subtilis C-3102 spores as a probiotic feed supplement on growth performance, noxious gas emission, and intestinal microflora in broilers

Bacillus subtilis C-3102 has been used as a direct-fed microbial or probiotic product since 1986 to improve production performance in broilers worldwide. This study was conducted to determine and confirm the effect of B. subtilis C-3102 spore supplementation to feed on growth performance, nutrient digestibility, carcass quality, blood profiles, noxious gas emission, and intestinal and excreta microflora in broilers. A total of 816 one-day-old male Ross 308 broilers (46.06 ± 0.67 g) were used in a 5-wk study with Calsporin, B. subtilis final product (1.0 × 10(9) cfu/g of B. subtilis). Broilers were randomly allotted to 1 of 3 dietary treatments consisting of 16 replicate cages with 17 broilers each: I) CON (control, basal diet), II) BS300 (CON + 300 mg of B. subtilis/kg of feed), and III) BS600 (CON + 600 mg of B. subtilis/kg of feed). Regarding probiotic effect, B. subtilis significantly increased Lactobacillus counts in the cecum, ileal, and excreta, and reduced Escherichia coli counts in the cecum and excreta, compared with CON. In addition, supplementation also tended to reduce Clostridium perfringens counts in the large intestine and excreta, while linearly reducing Salmonella counts in the cecum, ileal, large intestine, and excreta, compared with CON. Regarding growth performance, B. subtilis enhanced ADG in the starter and overall experimental periods, without any effects on feed intake compared with CON. Consequently, feed conversion ratio in the grower-finisher and overall experimental periods decreased significantly. The inclusion of B. subtilis improved the digestibility of DM and gross energy, as well as reducing ammonia emission, compared with CON. No significant difference in breast muscle color, water holding capacity, and drip loss, and relative organ weights, as well as in white blood cells, red blood cells, lymphocyte counts, and IgG amount, were observed. Overall, B. subtilis C-1302 is capable of providing a probiotic effect leading to improved growth performance and feed efficiency, due to the manipulation of intestinal microflora, with minimal side effects in broilers.

Influence of probiotics in different energy and nutrient density diets on growth performance, nutrient digestibility, meat quality, and blood characteristics in growing-finishing pigs

The study was conducted to determine the effects of probiotics (Bacillus subtilis endospore and Clostridium butyricum endospore complex) supplementation and different energy and nutrient densities on growth performance, nutrient digestibility, and meat quality in growing-finishing pigs. A total of 96 pigs with initial BW of 47.50 ± 1.14 kg were used in a 10-wk experiment. Pigs were randomly allotted to 1 of 4 treatments in a 2 × 2 factorial arrangement of treatments with 2 levels of energy and nutrient density (low and high energy, CP, and Lys) and 0.2% probiotics according to their sex and BW (6 pens, with 2 gilts and 2 barrows/pen). From 0 to 5 wk, ADG and G:F, as well as the apparent total tract digestibility (ATTD) of N and energy, were improved (P < 0.05) in the probiotic groups and in the high-energy and high-nutrient-density groups. From 6 to 10 wk, ADG and G:F, as well as the ATTD of DM, N, and energy, were increased (P < 0.01) when pigs were fed the high-energy and high-nutrient-density diets. Pigs fed the probiotic supplement or the high-energy and high-nutrient-density diets had increased (P < 0.01) ADG and G:F overall. Moreover, pigs fed the high-energy and high-nutrient-density diets had increased (P < 0.05) meat color scores, marbling scores, drip loss values, pH, and LM area (P < 0.05) compared with those fed the low-energy and low-nutrient-density diets, whereas the probiotic treatment groups had increased (P < 0.01) meat color scores, marbling scores, and redness values. The lightness and yellowness values in the low-energy and low-nutrient-density dietary treatments were greater (P < 0.05) than those in the high-energy and high-nutrient-density dietary treatments. Interactive effects of dietary energy and nutrient density and probiotics were also observed (P < 0.05) on the digestibility of N at wk 10 and energy at wk 5, as well as on meat firmness at the end of the experiment. In conclusion, dietary supplementation of probiotics increased growth performance throughout the experiment and exerted beneficial effects on ATTD. Meat quality was improved when pigs were fed high-energy and high-nutrient-density diets.

Comparison of different nutritional assessments in detecting malnutrition among gastric cancer patients

AIM: To evaluate the prevalence of preoperative and postoperative malnutrition and the relationships between objective and subjective nutritional assessment of gastric cancer patients.

METHODS: From October 2005 to July 2006, we studied 80 patients with no evidence of recurrent disease and no loss to follow-up after curative surgery for gastric cancer. In this group, 9 patients underwent total gastrectomy and 71 patients subtotal gastrectomy. At admission, 6 and 12 mo after surgery, the patients were assessed on the subjective global assessment (SGA), nutritional risk screening (NRS-2002), nutritional risk index (NRI) and by anthropometric measurements and laboratory data. Differences between the independent groups were assessed with the Student’s t test and one-way analysis of variance. Spearman’s rank correlation coefficients were calculated to evaluate the association between the scores and variables.

RESULTS: The prevalence of malnutrition at admission was 31% by SGA and 43% by NRS-2002. At admission, the anthropometric data were lower in the malnourished groups defined by the SGA and NRS-2002 assessments, but did not differ between the groups using the NRI assessment. Body weight (BW), body mass index (BMI), triceps skin fold and midarm circumference were significantly reduced, but the total lymphocyte count, albumin, protein, cholesterol and serum iron levels did not decrease during the postoperative period. Six months after surgery, there was a good correlation between the nutritional assessment tools (SGA and NRS-2002) and the other nutritional measurement tools (BW, BMI, and anthropometric measurements). However, 12 mo after surgery, most patients who were assessed as malnourished by SGA and NRS-2002 had returned to their preoperative status, although their BW, BMI, and anthropometric measurements still indicated a malnourished status.

CONCLUSION: A combination of objective and subjective assessments is needed for the early detection of the nutritional status in case of gastric cancer patients after gastrectomy.

Effects of multistrain probiotics on growth performance, apparent ileal nutrient digestibility, blood characteristics, cecal microbial shedding, and excreta odor contents in broilers

This experiment was conducted to investigate the efficacy of Lactobacillus acidophilus, Bacillus subtilis, and Clostridium butyricum supplementation in broilers. A total of 400 one-day-old mixed sex Ross 308 broilers with an initial average BW of 46 ± 0.5 g were randomly allotted into 4 treatments with 5 replicate pens per treatment and 20 broilers in each pen for 35 d. Dietary treatments were (1) an antibiotic-free diet (CON), (2) CON + 5 mg/kg of avilamycin, (3) CON + 1 × 10(5) cfu of multistrain probiotics/kg of diet (P1), and (4) CON + 2 × 10(5) cfu of multistrain probiotics/kg of diet (P2). Broilers fed the P1 and P2 diets had greater BW gain than broilers fed the CON diet during d 22 to 35 (P = 0.01) and overall (P = 0.02). Feed conversion ratios in P1 and P2 were decreased (P = 0.03) compared with that in CON from d 22 to 35. Ileal digestibility of most essential amino acids, with the exception of His and Phe, were increased (P < 0.05) in P1 and P2 compared with CON. Serum IgA and IgM concentrations in P2 were higher (P < 0.05) than those in CON. The cecal Lactobacillus numbers were increased (P = 0.02), and the counts of Escherichia coli were decreased (P = 0.03) in P1 and P2 compared with CON. Dietary supplementation with multistrain probiotics decreased (P < 0.05) the excreta NH3 content compared with the CON. In conclusion, dietary supplementation with multistrain probiotics improved broiler growth performance, ileal amino acids digestibility, and humoral immunity. Furthermore, the probiotics decreased the cecal numbers of E. coli and decreased the NH3 content of excreta.

Thioredoxin-linked "thiol peroxidase" from periplasmic space of Escherichia coli

Three different molecular masses (24, 22, and 20 kDa) of antioxidant proteins were purified in Escherichia coli. These proteins exhibited the preventive effects against the inactivation of glutamine synthetase activity and the cleavage of DNA by a metal-catalyzed oxidation system capable of generating reactive oxygen species. Their antioxidant activities were supported by a thiol-reducing equivalent such as dithiothreitol. Analysis of the amino-terminal amino acid sequences and the immunoblots between 24- and 22-kDa proteins indicates that the 24-kDa protein is an intact form of the 22-kDa protein that was previously identified 22-kDa subunit (AhpC) of E. coli alkyl hydroperoxide reductase (AhpC/AhpF). We isolated and sequenced an E. coli genomic DNA fragment that encodes 20-kDa protein. Comparison of the deduced amino acid sequence of the 20-kDa protein with that of AhpC revealed no sequence homology. A search of a data bank showed that the 20-kDa protein is a new type of antioxidant enzyme. The synthesis of this novel 20-kDa protein was increased in response to oxygen stress during growth. The 20-kDa protein resides mainly in the periplasmic space of E. coli, whereas the 24-kDa AhpC resides mainly in the matrix. The 20-kDa protein was functionally linked to the thioredoxin as an in vivo thiol-regenerating system and exerted a peroxidase activity. This 20-kDa protein is thus named "thiol peroxidase," which could act as an antioxidant enzyme removing peroxides or H2O2 within the catalase- and peroxidase-deficient periplasmic space of E. coli.

Characteristic immunostimulation by angelan isolated from Angelica gigas Nakai

The immunopharmacological characteristics of angelan, a polysaccharide purified from Angelica gigas Nakai, were investigated in relation to the specificity to immune cells. The treatment of angelan increased the expression of IL-2, IL-4, IL-6, and IFN-gamma. The expression of IL-6 and IFN-gamma was rapidly augmented but that of IL-2 responded later. In the case of IL-4, angelan stimulated at early time after exposure but down-regulated thereafter. These results suggested that macrophages and natural killer cells involved in nonspecific immunity were primarily activated and helper T cells were secondarily affected by angelan. Angelan also had lympho-proliferative potential to B cells, specifically. The specificity of angelan was also elucidated in a cell fractionation experiment. The activated B cells by angelan also increased antibody production. The direct activation of B cells, macrophages, and accessory cells and the indirect activation of helper T cells coordinately increased immune functions such as in vitro and in vivo T-dependent immunization and antibody production. The experiment of host resistance to syngeneic tumors also showed that angelan potentiated the immune functions. In conclusion, angelan, a purified polysaccharide from an oriental herbal drug, showed characteristic immunostimulation, which was different from clinically used polysaccharides such as lentinan and PSK.

Supplemental effect of probiotic Bacillus subtilis B2A on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality of growing broiler chicks

One-day-old Ross 308 male broiler chicks were used to investigate the additive effect during growth of Bacillus subtilis B2A derived from soil samples on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality. Five hundred seventy-six birds (46 ± 0.5 g) were fed 3 different levels of B. subtilis B2A (1.1 × 10(4), 1.0 × 10(5), and 1.0 × 10(6) cfu), in a basal diet based on corn-soybean meal, for 28 d. In the current study, feed intake and feed conversion during 1 to 28 d showed significant improvement as dietary B. subtilis B2A increased from 1.1 × 10(4) to 1.0 × 10(6) cfu (linear, P < 0.05). All blood parameters, such as white blood cells, red blood cells, and lymphocyte and haptoglobin concentrations, were not influenced by B. subtilis B2A added into the diet; however, the weights of the bursa of Fabricius were significantly increased linearly in B. subtilis B2A-fed groups (P < 0.05). Bacillus subtilis B2A supplementation was associated with reduced intestinal Salmonella burden (linear and quadratic, P < 0.05). Breast meat pH and color were not affected by B. subtilis B2A, but 1 d drip loss was decreased (linear, P < 0.05). Our observations suggest that B. subtilis B2A benefits productivity and reduces Salmonella in broilers.

Correlation of cervical carcinoma and precancerous lesions with human papillomavirus (HPV) genotypes detected with the HPV DNA chip microarray method

BACKGROUND

Human papillomavirus (HPV) infection is considered to play an important role in the development of cervical carcinoma, and it is known that certain HPV types, such as HPV-16 and HPV-18, are highly associated with cervical carcinoma. However, the pathologic behavior of other HPV types remains unclear. Recently, a new HPV detection technique, the HPV DNA chip, was introduced. The HPV DNA chip harbors 22 HPV probes and has the advantage of being able to detect 22 HPV types simultaneously. To evaluate the quality of the HPV DNA chip method and to identify HPV types related to cervical carcinoma and precancerous lesions, the authors performed HPV typing in cervical specimens from 1983 patients and compared their cytologic and histologic diagnoses.

METHODS

The HPV DNA chip was used for HPV typing. Among 1983 patients who were tested for HPV types, cervical smear cytology was performed in 1650 patients, and 677 of those patients underwent cervical biopsy.

RESULTS

Among the 1650 smears that were examined cytologically, 92.7% (114 of 123 smears) of low-grade squamous intraepithelial lesions (LSILs), 98.1% (106 of 108 smears) of high-grade squamous intraepithelial lesions (HSILs), and 96.3% (51 of 53 smears) of carcinomas were HPV positive, compared with only 35.1% of smears with normal cytology that were HPV positive. HPV-16 was the most prevalent type (chi-square test; P < 0.01) in LSILs (28.5%), in HSILs (51.9%), and in carcinomas (62.5%) followed by HPV-58 and a group of low-risk types (HPV-6, HPV-11, HPV-34, HPV-40, HPV-42, HPV-43,and HPV-44) in LSILs. HPV-58 (15.7%), HPV-18 (6.7%), and HPV-52 (4.6%) were the next most prevalent types after HPV-16 in HSILs. HPV-18 (11.4%) and HPV-58 (11.4%) were the second most common types in carcinomas. HPV-58 had the highest positive predictive value (54.9%) for the detection of histologically confirmed HSIL or carcinoma, whereas HPV 16 had the highest negative predictive value (80.6%). The sensitivity (96.0%) of the HPV test using the DNA chip method for detecting HSIL or carcinoma was superior compared with the sensitivity of cytologic diagnosis (83.6%).

CONCLUSIONS

The HPV DNA chip provides a very sensitive method for detecting 22 HPV genotypes with reasonable sensitivity (96.0%) and reasonable negative predictive value (96.9%), and it overcomes the low sensitivity of cytologic screening for the detection of HSIL or carcinoma. HPV-58, HPV-52, and HPV-56, as well as HPV-16 and HPV-18, were associated highly with HSIL and carcinoma in the current large series. In addition, multiple HPV infection was associated less frequently with cervical carcinoma and with precancerous lesions compared with normal cytology.

Mussel Inspired Highly Aligned Ti3C2Tx MXene Film with Synergistic Enhancement of Mechanical Strength and Ambient Stability

Two-dimensional (2D) MXene has shown enormous potential in scientific fields, including energy storage and electromagnetic interference (EMI) shielding. Unfortunately, MXene-based material structures generally suffer from mechanical fragility and vulnerability to oxidation. Herein, mussel-inspired dopamine successfully addresses those weaknesses by improving interflake interaction and ordering in MXene assembled films. Dopamine undergoes in situ polymerization and binding at MXene flake surfaces by spontaneous interfacial charge transfer, yielding an ultrathin adhesive layer. Resultant nanocomposites with highly aligned tight layer structures achieve approximately seven times enhanced tensile strength with a simultaneous increase of elongation. Ambient stability of MXene films is also greatly improved by the effective screening of oxygen and moisture. Interestingly, angstrom thick polydopamine further promotes the innate high electrical conductivity and excellent EMI shielding properties of MXene films. This synergistic concurrent enhancement of physical properties proposes MXene/polydopamine hybrids as a general platform for MXene based reliable applications.

Induction of an antioxidant protein of Saccharomyces cerevisiae by O2, Fe3+, or 2-mercaptoethanol

A soluble 27-kDa protein from Saccharomyces cerevisiae specifically prevents the inactivation of various enzymes caused by a nonenzymatic Fe3+/O2/thiol mixed-function oxidation system but not by mixed-function oxidation systems in which the thiol component is replaced by another electron donor-e.g., ascorbate. In this report, using a 125I-labeled monospecific antibody against the 27-kDa protein, we measured changes in the 27-kDa protector protein in response to changes in oxidative stress and heat shock. With a shift from an anaerobic (95% N2/5% CO2) to a hyperaerobic (95% O2/5% CO2) atmosphere, a 3-fold increase was observed. This increase was prevented by cycloheximide, indicating that the induction requires new protein synthesis. The antioxidant protein synthesis was also significantly enhanced by the addition of either 2-mercaptoethanol or Fe3+ to the growth medium. Radioimmunoassay results also show that the antioxidant protein is an abundant protein, as it constitutes 0.7% of total soluble protein from yeast grown aerobically. Immunoblotting experiments revealed that rat tissues also contain a 27-kDa protein that can be specifically recognized by antibodies against the yeast protein. These results suggest that in vivo induction in yeast of the 27-kDa protein may represent an adaptive response that evolved to protect cells against damage caused by thiol-dependent mixed-function oxidation systems, and the antioxidant protein is conserved in mammalian tissues. A heat shock applied to yeast did not cause any significant increases in the concentration of the 27-kDa protein.

Long-term stable correction of low-density lipoprotein receptor-deficient mice with a helper-dependent adenoviral vector expressing the very low-density lipoprotein receptor

BACKGROUND

Familial hypercholesterolemia (FH) that results from LDL receptor (LDLR) deficiency affects approximately 1 in 500 persons in the heterozygous state and approximately 1 in 1 million persons in the homozygous state. We tested a novel gene therapy strategy for the treatment of FH in a mouse model.

METHODS AND RESULTS

We delivered the VLDL receptor (VLDLR) to the liver of LDLR-deficient mice and compared the effect of a helper-dependent adenoviral vector with all viral coding sequences deleted (HD-Ad-mVLDLR) with a first-generation vector (FG-Ad-mVLDLR), an HD-Ad (HD-Ad-0) that contained no expression cassette, and dialysis buffer (DB). A single intravenous injection of HD-Ad-mVLDLR led to a lowering of plasma cholesterol that lasted >/=6 months. Acute liver toxicity (as measured with liver enzyme elevation) occurred after FG-Ad-mVLDLR but not after HD-Ad-mVLDLR, HD-Ad-0, or DB treatment. At 6 months, VLDLR was detected in the liver with Western blotting and with immunofluorescence staining only in HD-Ad-mVLDLR-treated mice. Aortic atherosclerosis was almost completely prevented in these animals.

CONCLUSIONS

HD-Ad-mediated intravenous delivery of VLDLR to hepatocytes is well tolerated. It produces long-term lowering of plasma cholesterol and prevents atherosclerosis development in LDLR-deficient mice. These data provide support for the feasibility and safety of this approach for therapy of human subjects.

Inhibition of aromatase activity by flavonoids

In searching for potent cancer chemopreventive agents from synthetic or natural products, 28 randomly selected flavonoids were screened for inhibitory effects against partially purified aromatase prepared from human placenta. Over 50% of the flavonoids significantly inhibited aromatase activity, with greatest activity being demonstrated with apigenin (IC50: 0.9 microg/mL), chrysin (IC50: 1.1 microg/mL), and hesperetin (IC50: 1.0 microg/mL).

Structural properties of cellulose and cellulase reaction mechanism

The effects of structural properties and their changes during cellulose hydrolysis on the enzymatic hydrolysis rate have been studied from the reaction mechanism point of view. Important findings are the following: (1) The crystallinity index (CrI) of partially crystalline cellulose increases as the hydrolysis reaction proceeds, and a significant slowing down of the reaction rate during the enzymatic hydrolysis is, in large part, attributable to this structural change of cellulose substrate. (2) The crystallinity of completely disordered cellulose, like phosphoric-acid-treated cellulose, does not change significantly, and a relatively high hydrolysis rate is maintained during hydrolysis. (3) The specific surface area (SSA) of partially crystalline cellulose decreases significantly during enzymatic hydrolysis while the change in SSA of regenerated cellulose is found to be negligible. (4) The value of degree of polymerization (DP) of highly ordered crystalline cellulose remains practically constant whereas the change in DP of disordered regenerated cellulose is found to be very significant. (5) Combination of these structural effects as well as cellulase adsorption, product inhibition, and cellulase deactivation all have important influence on the rate of cellulase reaction during cellulose hydrolysis. More experimental evidence for a two-phase model, which is based on degradation of cellulose by simultaneous actions of cellulase complex on the crystalline and amorphous phases, has been obtained. Based on experimental results from this study and other results accumulated, the mode of cellulase action and a possible reaction mechanism are proposed.

Central neurocytoma: the role of radiation therapy and long term outcome

BACKGROUND

It has been suggested that the biologic behavior of central neurocytoma is indolent, although little is known regarding the role of radiation therapy and long term outcome. To clarify the role of radiation therapy and long term outcome, the authors retrospectively analyzed 15 cases of central neurocytoma.

METHODS

Clinical records and radiologic findings of 15 cases of central neurocytoma diagnosed at Seoul National University Hospital between January 1982 and February 1995 were carefully reviewed. The duration of follow-up was from 18-168 months (mean, 52 months); follow-up images were reviewed and the patient's Karnofsky performance scale (KPS) was assessed up to the time of last follow-up.

RESULTS

The age of the patients ranged from 15 to 60 years (mean, 25 years) and the male to female ratio was 11:4. Macroscopic total resection of the tumor was performed in seven patients, two of whom received fractionated radiation therapy. Subtotal removal of the tumor was performed in eight patients, five of whom received this same therapy. In 2 of the 5 patients who did not receive radiation therapy after macroscopic total resection, the tumors recurred 8 and 21 months after surgery, respectively; in contrast, recurrence was not detected in the 2 patients who received fractionated radiation therapy after macroscopic total resection. In all five patients who received fractionated radiation therapy after subtotal resection, the tumor shrank (n = 3) or disappeared (n = 2) during the postsurgical follow-up period ranging from 27-113 months; the tumor began to shrink from 6 months to 2 years after radiation. No change was found in the three patients who did not receive radiation therapy after subtotal resection. At the time of last follow-up, the KPS was greater than 90 in all patients except one who required assistance in his daily activities because of complications from radiation therapy.

CONCLUSIONS

It is suggested that even if the biologic behavior of a central neurocytoma is benign, radiation therapy appears to have an effect on tumor control. However, it should be carefully decided whether to use radiation therapy for a residual tumor because radiation can cause delayed complications and the clinical course of subtotally resected patients who do not receive radiation therapy is extremely benign.

Glutathione-linked thiol peroxidase activity of human serum albumin: a possible antioxidant role of serum albumin in blood plasma

A 65-kDa molecular mass of thiol-specific antioxidant protein was purified from human plasma and identified as human serum albumin (HSA) by the analysis of amino-terminal amino acid sequence. This protein exhibited the preventive effects against the inactivation of glutamine synthetase activity and the peroxidation of lipid by a metal-catalyzed oxidation system. These antioxidant activities were supported by a thiol-reducing equivalent such as DTT and reduced glutathione. The thiol-specific antioxidant activity of HSA was greatly activated by halide ion, especially by chloride ion. HSA showed a significant capability to destroy H2O2 in the presence of reduced glutathione, resulting in the production of oxidized glutathione. Both the preventive activity against the glutamine synthetase inactivation and the peroxidase activity were completely abolished by the reactions of HSA with N-ethylmaleimide and iodoacetate, chemical modification agents for sulfhydryl of protein, only in the presence of thiol-reducing equivalent such as DTT. These results suggest that serum albumin acts as a major and predominate antioxidant exerting a glutathione-linked thiol peroxidase activity which removes reactive oxygen species such as H2O2 within blood plasma.

Decursin: a cytotoxic agent and protein kinase C activator from the root of Angelica gigas

A cytotoxic compound was purified from the root of Angelica gigas Nakai by silica gel chromatography and preparative HPLC. As a result of the structure analysis by mass, IR, 1H-NMR, and 13C-NMR spectrometry, the effective compound was identified as decursin, a pyranocoumarin characterized originally from Angelica decursiva Fr. et Sav. In vitro cytotoxicity testing showed that decursin displayed toxic activity against various human cancer cell lines, for which the ED50 of decursin was about 5-16 micrograms/ml. On the other hand, decursin displayed relatively low cytotoxicity against normal fibroblasts. Decursin also activated protein kinase C (PKC) in vitro, which indicates that the cytotoxic activity of decursin may be related to the protein kinase C activation.

Effect of dietary Spirulina (Arthrospira) platensis on the growth performance, antioxidant enzyme activity, nutrient digestibility, cecal microflora, excreta noxious gas emission, and breast meat quality of broiler chickens

This study examined the effects of dietary Spirulina (Arthrospira) platensis supplementation on growth performance, antioxidant enzyme activity, nutrient digestibility, cecal microflora, excreta noxious gas emission, organ weight and breast meat quality in broiler chickens. In total, 800 Ross 308 male broiler chickens (1-d-old) were randomly divided into 5 dietary treatments with 10 replicate cages (16 birds/replicate) per treatment for 5 wk. The dietary treatments were a control basal diet without Spirulina or with 0.25, 0.5, 0.75, or 1.0% Spirulina. Body weight gain, feed conversion, and/or European production efficiency index improved linearly with supplementation of Spirulina during d 8 to 21, 22 to 35, and overall d 1 to 35 (P < 0.05). Dietary Spirulina supplementation caused a significant increase in the serum enzyme activity of superoxide dismutase and glutathione peroxidase (linear, P < 0.05). Apparent total tract digestibility of dry matter and nitrogen showed a linear increase in Spirulina supplementation (P < 0.05). Cecal Lactobacillus count linearly increased and excreta ammonia gas emission linearly decreased, as dietary Spirulina supplementation increased (P < 0.05). There were no significant effects on relative organ weight and breast meat quality of broilers fed with Spirulina diets; however, 7 d drip loss linearly decreased in treatment groups fed with Spirulina (P < 0.05). These results indicate that adding Spirulina to the diet of broilers can improve antioxidant enzyme activity, dry matter and nitrogen digestibility, cecal Lactobacillus population, excreta ammonia gas emission, and 7 d drip loss of breast meat. In addition, dietary inclusion of 1.0% Spirulina powder might provide a good alternative to improve broiler chicken production.

Inhibition of metal-catalyzed oxidation systems by a yeast protector protein in the presence of thioredoxin

A protector protein from Saccharomyces cerevisiae specifically prevents the inactivation of enzymes caused by a thiol/Fe3+/O2 metal-catalyzed oxidation system but not by an ascorbate/Fe3+/O2 system. Ascorbate/Fe3+/O2-mediated damage of enzymes could be prevented by the protector protein only in the presence of reduced thiol. We demonstrate that two proteins from yeast, thioredoxin plus another protein having properties similar to that expected to thioredoxin reductase, when presented with NADPH and the yeast protector protein prevented inactivation of E. coli glutamine synthetase by the ascorbate/Fe3+/O2 system. This system also removes hydrogen peroxide effectively. We also demonstrate evidence suggesting that the NADPH-dependent thioredoxin system reactivates protector protein by reversible disulfide-dithiols exchange.

Effects of lactation and pregnancy on gene expression of endometrium of Holstein cows at day 17 of the estrous cycle or pregnancy

Objectives were to determine effects of lactation and pregnancy on endometrial gene expression on d 17 of the estrous cycle and pregnancy. Heifers (n = 33) were assigned randomly after parturition to lactating (L, n = 17) or nonlactating (NL, n = 16) groups. Cows were subjected to an ovulation synchronization program for a timed artificial insemination (TAI); 10 cows in L and 12 in NL were inseminated. Slaughter occurred 17 d after the day equivalent to TAI, and intercaruncular endometrial tissues were collected. Gene expression was determined by DNA microarray analysis for pregnant (L, n = 8; NL, n = 6) and noninseminated cyclic (L, n = 7; NL, n = 4) cows. Differentially expressed genes were selected with a P-value <0.01 and absolute expression >40. In addition, a fold effect >1.5 was used as a criterion for genes affected by pregnancy. In total, 210 genes were differentially regulated by lactation (136 downregulated and 74 upregulated), and 702 genes were differentially regulated by pregnancy (407 downregulated and 295 upregulated). The interaction effect of pregnancy and lactation affected 61 genes. Genes up- and downregulated in pregnant cows were associated with several gene ontology terms, such as defense response and interferon regulatory factor, cell adhesion, and extracellular matrix. The gene ontology analyses of up- and downregulated genes of lactating cows revealed terms related to immunoglobulin-like fold, immune response, COMM domain, and non-membrane-bounded organelle. Several genes upregulated by lactation, such as IGHG1, IGLL1, IGK, and TRD, were related to immune function, particularly for B cells and γδ T cells. Developmental genes related to limb and neural development and glucose homeostasis (e.g., DKK1, RELN, PDK4) were downregulated by lactation, whereas an interaction was also detected for RELN. The stated genes associated with immune function and developmental genes expressed in the endometrium affected by lactational state are possible candidate genes for interventions to improve fertility of lactating dairy cows.

Intramedullary spinal cord astrocytoma in adults: postoperative outcome

Intramedullary spinal cord astrocytomas are relatively rare and usually low-grade lesions with a long natural history. The rarity of the condition and its indolent clinical course has made the evaluation of treatment efficacy difficult. To clarify postoperative outcome and prognostic factors, we performed a retrospective analysis of intramedullary spinal cord astrocytomas in a single institute. Twenty-eight patients were surgically treated between 1978 and 1999; of median age 36 years (range, 19-68 years); nineteen patients were males and nine females. All patients presented with pain and neurological deficits. The cervical cord was involved in fifteen patients, cervico-thoracic in five, thoracic in six and thoraco-lumbar in two. Gross total removal was performed in three patients, subtotal removal in six, partial removal in fourteen and biopsy only in five. Nineteen patients received radiation therapy postoperatively. The mean follow-up period was 31.9 months (range, 0.5-184 months). Low-grade astrocytomas were found in 18 cases, anaplastic astrocytoma in three cases and glioblastomas in seven cases. The median survivals of patients with low- and high-grade astrocytoma were 184 months and 8 months, respectively (p < 0.05). The median survivals of irradiated and non-irradiated patients with low-grade astrocytoma were 184 months and 102 months. Neither the extent of resection, nor radiation influenced the survival rate. In summary, the histological grade was the most significant predictor of survival in patients with astrocytoma of the spinal cord.

Purification and characterization of thiol-specific antioxidant protein from human red blood cell: a new type of antioxidant protein

A thiol-specific antioxidant protein (Protector Protein, PRP) was purified from human red blood cells (RBC). The PRP exists as a predominant protein in human RBC, which showed distinct thiol-specific antioxidant activities in the presence of dithiothreitol (DTT) as a reducing equivalent. The human RBC PRP (HRPRP) completely inhibited visible absorption spectral changes of oxyhemoglobin, DNA cleavage, and the peroxidation of RBC membrane by a nonenzymatic Fe3+/O2/thiol mixed-function oxidation system capable of generating hydroxyl radical. These observations suggest that HRPRP could act as a new type of antioxidant protein to maintain the RBC integrity by scavenging reactive oxygen species.