Effects of Dietary Protein Concentration on Lipid Metabolism Gene Expression and Fatty Acid Composition in 18-23-Month-Old Hanwoo Steers

The present study evaluated the influence of dietary protein level on growth performance, fatty acid composition, and the expression of lipid metabolic genes in intramuscular adipose tissues from 18- to 23-month-old Hanwoo steers, representing the switching point of the lean-to-fat ratio. Forty steers with an initial live weight of 486 ± 37 kg were assigned to one of two treatment groups fed either a concentrate diet with 14.5% CP and or with 17% CP for 6 months. Biopsy samples of intramuscular tissue were collected to analyze the fatty acid composition and gene expression at 23 months of age. Throughout the entire experimental period, all steers were restrained twice daily to allow individual feeding. Growth performance, blood metabolites, and carcass traits, according to ultrasonic measurements, were not affected by the experimental diets. The high-protein diet significantly increased the expression of intramuscular PPARα (p < 0.1) and LPL (p < 0.05) but did not affect genes involved in fatty acid uptake (CD36 and FABP4) nor lipogenesis (ACACA, FASN, and SCD). In addition, it downregulated intramuscular VLCAD (p < 0.01) related to lipogenesis but also GPAT1 (p = 0.001), DGAT2 (p = 0.016), and SNAP23 (p = 0.057), which are involved in fatty acid esterification and adipocyte size. Hanwoo steers fed a high-protein diet at 18-23 months of age resulted in a relatively lower lipid turnover rate than steers fed a low-protein diet, which could be responsible for shortening the feeding period.

Investigation of blood biomarkers related to meat quality and quantity in Hanwoo steers

Objective

This study was conducted to investigate the correlation between blood components and carcass traits, and to find the biomarkers related to meat quality and quantity in Hanwoo steers.

Methods

One hundred twenty-six Hanwoo steers (8 to 9 months of age, body weight of 185.6±24.38 kg) were used to find the correlation between blood compositions and carcass traits. The steers were fed concentrate and rice straw (30 steers) or total mixed rations (96 steers) during the whole experimental period. Blood samples were collected from the jugular vein at the growing (8 to 12 months), fattening (13 to 23 months) and finishing phases (24 to 30 months). Steers were slaughtered at 30 to 31 months of age (body weight of 701.6±60.45 kg) and the carcass traits were evaluated. Blood metabolites and hormones were analyzed and the correlation coefficients and regression equations with carcass traits were determined.

Results

Average concentrations of retinol, leptin and insulin were 1.10 IU, 30.34 ng, and 35.35 ng per mL of blood plasma, respectively. Retinol has negative correlations (p<0.01) with insulin and leptin. Blood insulin and total protein decreased with the age of steers, but retinol, aspartic acid transaminase (AST), glucose, cholesterol and triglyceride increased. In the finishing phase, significant (p<0.01) negative correlations occurred between blood retinol content and marbling score, and between blood AST content and longissimus muscle area of 13th rib, and the following regression equations were obtained: Marbling score (1–9) = −0.009×retinol (IU/100 mL)+ 9.125 (R² = 0.643), Longissimus muscle area (cm²) = −0.250× AST(U/L)+112.498 (R² = 0.450).

Conclusion

It is possible to make highly marbled beef by controlling the blood retinol content during the fattening and finishing phases of Hanwoo steers. Accordingly, blood retinol and AST could be biomarkers for determining beef quality and quantity, respectively, prior to slaughter.

Effects of feeding system on growth performance, plasma biochemical components and hormones, and carcass characteristics in Hanwoo steers

OBJECTIVE

This study was conducted to compare growth performance, blood components and carcass traits by two feeding systems (concentrate with roughage separately [CON] vs total mixed ration [TMR]) in Hanwoo steers, and to learn the relationship between blood components during fattening or finishing phases and carcass traits in Hanwoo steers.

METHODS

Sixty steers aged 8 months were allotted to two feeding systems and fed similar amounts of average dry matter and total digestible nutrient throughout whole experimental period according to each feeding program. Steers were weighed monthly, taken blood at the end of growing, fattening and finishing periods, and slaughtered at 30 month of age.

RESULTS

Growing performance was higher (p<0.05) in the CON group compared to the TMR group during fattening and finishing periods. The CON group was lower (p<0.05) in blood aspartic acid transaminase, blood urea nitrogen and retinol levels during growing period, but higher in triglyceride and cholesterol levels during fattening and finishing periods compared to the TMR group. The CON group was greater (p<0.05) in rib-eye area, and lighter (p<0.05) red in meat color compared to the TMR group. In the correlation coefficients between blood components of steers and carcass traits, retinol had a negative (p<0.05) correlation with marbling score and rib-eye area. Leptin had a positive (p<0.05) correlation with back fat thickness. Blood cholesterol and triglyceride were positively (p<0.05) correlated with carcass weight and rib-eye area.

CONCLUSION

Growth performance, carcass ribeye area and meat color showed a more desirable result in the CON compared to the TMR in Hanwoo steers. Assessing the accumulated data of carcass traits with blood components including hormones-particularly retinol, cholesterol, triglyceride, and leptin-during the fattening or finishing phases, it may be possible to find a biomarker for determining beef quality in living animals.

Responses of blood glucose, insulin, glucagon, and Fatty acids to intraruminal infusion of propionate in hanwoo

This study was carried out to investigate the effects of intraruminal infusion of propionate on ruminal fermentation characteristics and blood hormones and metabolites in Hanwoo (Korean cattle) steers. Four Hanwoo steers (average body wt. 270 kg, 13 month of age) equipped with rumen cannula were infused into rumens with 0.0 M (Water, C), 0.5 M (37 g/L, T1), 1.0 M (74 g/L, T2) and 1.5 M (111 g/L, T3) of propionate for 1 hour per day and allotted by 4×4 Latin square design. On the 5th day of infusion, samples of rumen and blood were collected at 0, 60, 120, 180, and 300 min after intraruminal infusion of propionate. The concentrations of serum glucose and plasma glucagon were not affected (p>0.05) by intraruminal infusion of propionate. The serum insulin concentration at 60 min after infusion was significantly (p<0.05) higher in T3 than in C, while the concentration of non-esterified fatty acid (NEFA) at 60 and 180 min after infusion was significantly (p<0.05) lower in the propionate treatments than in C. Hence, intraruminal infusion of propionate stimulates the secretion of insulin, and decreases serum NEFA concentration rather than the change of serum glucose concentration.

Effects of Coconut Materials on In vitro Ruminal Methanogenesis and Fermentation Characteristics

The objective of this study was to evaluate the in vitro effects of coconut materials on ruminal methanogenesis and fermentation characteristics, in particular their effectiveness for mitigating ruminal methanogenesis. Fistulated Holstein cows were used as the donor of rumen fluid. Coconut materials were added to an in vitro fermentation incubated with rumen fluid-buffer mixture and timothy substrate for 24 h incubation. Total gas production, gas profiles, total volatile fatty acids (tVFAs) and the ruminal methanogens diversity were measured. Although gas profiles in added coconut oil and coconut powder were not significantly different, in vitro ruminal methane production was decreased with the level of reduction between 15% and 19% as compared to control, respectively. Coconut oil and coconut powder also inhibited gas production. The tVFAs concentration was increased by coconut materials, but was not affected significantly as compared to control. Acetate concentration was significantly lower (p<0.05), while propionate was significantly higher (p<0.05) by addition of the coconut materials than that of the control. The acetate:propionate ratio was significantly lowered with addition of coconut oil and coconut powder (p<0.05). The methanogens and ciliate-associated methanogens in all added coconut materials were shown to decrease as compared with control. This study showed that ciliate-associated methanogens diversity was reduced by more than 50% in both coconut oil and coconut powder treatments. In conclusion, these results indicate that coconut powder is a potential agent for decreasing in vitro ruminal methane production and as effective as coconut oil.

Changes in microbial diversity, methanogenesis and fermentation characteristics in the rumen in response to medicinal plant extracts

This study evaluated the in vitro effect of medicinal plant extracts on ruminal methanogenesis, four different groups of methanogens and ruminal fermentation characteristics. A fistulated Holstein cow was used as a donor of rumen fluid. Licorice and mugwort extracts (Glycyrrhiza uralensis and Artemisia capillaris, 0.5% and 1% of total substrate DM, respectively), previously used as folk remedies, were added to an in vitro fermentation incubated with buffered-rumen fluid. Total gas production in Glycyrrhiza uralensis extract treatment was not significantly different between treatments (p<0.05) while total gas production in the Artemisia capillaris extract treatment was lower than that of the control. Artemisia capillaris extract and Glycyrrhiza uralensis extract reduced CH₄ emission by 14% (p<0.05) and 8% (p<0.05), respectively. Ciliate-associated methanogens population decreased by 18% in the medicinal plant extracts treatments. Medicinal plant extracts also affected the order Methanobacteriales community. Methanobacteriales diversity decreased by 35% in the Glycyrrhiza uralensis extract treatment and 30% in the Artemisia capillaris extract treatment. The order Methanomicrobiales population decreased by 50% in the 0.5% of Glycyrrhiza uralensis extract treatment. These findings demonstrate that medicinal plant extracts have the potential to inhibit in vitro ruminal methanogenesis.

Effects of Supplementing Microbially-fermented Spent Mushroom Substrates on Growth Performance and Carcass Characteristics of Hanwoo Steers (a Field Study)

This study evaluated the effect of dietary supplementation of microbially-fermented spent mushroom substrates (MFSMS) on weight gain, carcass characteristics, and economic efficiency of Hanwoo steers. Highly cellulolytic bacteria (Enterobacter spp. and Bacillus spp.) isolated from spent mushroom substrates (SMS) stacks were inoculated (1% v/v) into the SMS, which was anaerobically fermented and fed to the steers for 12.6 months during the growing and fattening periods. Growing Hanwoo steers were assigned to the control group without supplementation of Microbially-fermented SMS (MFSMS), to a treatment group with 50% of MFSMS (1/2 of the ad libitum group), and to a treatment group with ad libitum access to SMS (the ad libitum group). All the groups were fed the formulated feed and rice straw. The voluntary intake (DM basis) of MFSMS was 1.6 kg/d during the growing period and 1.4 kg/d during the fattening period. The voluntary rice straw intake decreased by 6 to 11%, but the total voluntary DMI increased by 7 to 15% with MFSMS fed. The increased DMI with MFSMS supplementation resulted in a tendency of increased (p = 0.055) live weight gain by 8 to 12% compared with the control group. At slaughtering, the supplementation of MFSMS increased (p<0.05) the ribeye area by an average of 10 cm(2). In conclusion, feeding MFSMS improved growth performance and carcass traits of Hanwoo steers and could successfully replace a part of conventional roughage such as rice straw commonly used in Asian countries.

The Effect of Plant Extracts on In-vitro Ruminal Fermentation, Methanogenesis and Methane-related Microbes in the Rumen

The effect on methanogens attached to the surface of rumen ciliate protozoa by the addition of plant extracts (pine needles and ginkgo leaves) was studied with particular reference to their effectiveness for decreasing methane emission. The plant extracts (pine needles and ginkgo leaves) were added to an in vitro fermentation incubated with rumen fluid. The microbial population including bacteria, ciliated-associated methanogen, four different groups of methanogens and Fibrobacter succinogenes were quantified by using the real-time PCR. Gas profiles including methane, carbon dioxide and hydrogen, and runinal fermentation characteristics were observed in vitro. The methane emission from samples with an addition of individual juices from pine needles, ginkgo leaves and 70% ethanol extract from ginko leaves was significantly lower (p<0.05, 27.1, 28.1 and 28.1 vs 34.0 ml/g DM) than that of the control, respectively. Total VFAs in samples with an addition of any of the plant extracts were significantly lower than that of the control (p<0.05) as well. The order Methanococcales and the order Methanosarcinales were not detected by using PCR in any incubated mixtures. The ciliate-associated methanogens population decreased from 25% to 49% in the plant extacts as compared to control. We speculate that the supplementation of juice from pine needles and ginkgo leaves extract (70% ethanol extract) decreased the protozoa population resulting in a reduction of methane emission in the rumen and thus inhibiting methanogenesis. The order Methanobacteriales community was affected by addition of all plant extracts and decreased to less than the control, while the order Methanomicrobiales population showed an increase to more than that of the control. The F. succinogenes, the major fibrolytic microorganism, population in all added plant extracts was increased to greater than that of the control. In conclusion, pine needles and ginkgo leaves extracts appear to have properties that decrease methanogenesis by inhibiting protozoa species and may have a potential for use as additives for ruminants.

Selective ABTS Radical-Scavenging Activity of Prenylated Flavonoids fromCudrania tricuspidata

The antioxidative properties of five prenylated flavonoids, including new flavanone (2), from the root bark of Cudrania tricuspidata were examined against the ABTS, DPPH, and hydroxyl radicals. In most of the assays to determine their antioxidative properties, the ABTS activity was strongly correlated with DPPH because both methods are responsible for the same chemical property of hydrogen- or electron-donation to the antioxidant. On the other hand, the prenylated flavonoids (1-5) acted differently with both methods; namely, all the prenylated flavonoids strongly scavenged the ABTS radical (IC(50) < 10 microM), while they were inactive against the DPPH radical (IC(50) > 300 microM). Even though isolated 5,7,2',4',-tetrahydroxy-6,5'-diprenylflavanone (3) showed weak reducing power (746 mV) by cyclic voltammetry when compared to quercetin (394 mV), both had similar ABTS activity (IC(50) < 5 microM).

Kurarinol, tyrosinase inhibitor isolated from the root of Sophora flavescens

It is well known that flavanones, sophoraflavanone G 1, kurarinone 2, and kurarinol 3, from the root of Sophora flavescens, have extremely strong tyrosinase inhibitory activity. This study delineates the principal pharmacological features of kurarinol 3 that lead to inhibition of the oxidation of l-tyrosine to melanin by mushroom tyrosinase (IC(50) of 100 nM). The inhibition kinetics analyses unveil that compounds 1 and 2 are noncompetitive inhibitors. However similar analysis shows kurarinol 3 to be a competitive inhibitor. Compounds 1 and 2 exhibited potent antibacterial activity with 10 microg/disk against Gram-positive bacteria, whereas kurarinol 3 did not ostend any antibacterial activity. Interestingly, kurarinol 3 inhibits production of melanin in S. bikiniensis without affecting the growth of microorganism. It is thus distinctly different from the other tyrosinase inhibitors 1 and 2. In addition, kurarinol 3 manifests relatively low cytotoxic activity (EC(50)>30 microM) compared to 1 and 2. To account for these observations, we conducted molecular modeling studies. These suggested that the lavandulyl group within 3 is instrumental in the interaction with the enzyme. More specifically, the terminal hydroxy function within the lavandulyl group is most important for optimal binding.

Synthesis of All Four Stereoisomers of 3-Amino-2-hydroxybutanoic Acids

All four stereoisomers of 3-amino-2-hydroxybutanoic acids were been obtained as single enantiomers via stereospecific reactions from D-gulonic acid gamma-lactone and D-glucono-delta-lactone.

An experimental model of ischemia in rabbit hindlimb

This study was performed to establish an experimental model of ischemia for the investigation of new treatment modality of limb-threatening ischemia. We produced ischemia in the hindlimbs of 8 New Zealand white rabbits. Under general anesthesia, the left femoral artery was exposed, freed, and excised from distal external iliac artery to proximal popliteal and saphenous arteries. And then both hindlimbs were serially examined to assess the ischemia according to the time table until postoperative 6 weeks. We assessed clinical observation, blood pressure, radioisotopic perfusion scan, and angiography. Clinical ischemic changes of the operated feet were observed in 63%. The blood pressure of left calves was measurable on postoperative day 3 (p<0.05, vs preoperative day 2) and then gradually increased to reach a plateau in postoperative week 6. Radioisotopic arterial perfusion showed similar profiles as in blood pressure. Angiography of ischemic hindlimbs demonstrated a few collateral vessels arising from the internal iliac artery with the reconstitution of the posterior tibial artery in postoperative week 2. In postoperative week 6, collaterals remained the same in number. However, these became dilated and tortuous and showed reconstitution in distal hindleg. In conclusion, this is a reproducible, measurable, and economical animal model of hind limb ischemia.

EMF1, a novel protein involved in the control of shoot architecture and flowering in Arabidopsis

Shoot architecture and flowering time in angiosperms depend on the balanced expression of a large number of flowering time and flower meristem identity genes. Loss-of-function mutations in the Arabidopsis EMBRYONIC FLOWER (EMF) genes cause Arabidopsis to eliminate rosette shoot growth and transform the apical meristem from indeterminate to determinate growth by producing a single terminal flower on all nodes. We have identified the EMF1 gene by positional cloning. The deduced polypeptide has no homology with any protein of known function except a putative protein in the rice genome with which EMF1 shares common motifs that include nuclear localization signals, P-loop, and LXXLL elements. Alteration of EMF1 expression in transgenic plants caused progressive changes in flowering time, shoot determinacy, and inflorescence architecture. EMF1 and its related sequence may belong to a new class of proteins that function as transcriptional regulators of phase transition during shoot development.

EMF1, a novel protein involved in the control of shoot architecture and flowering in Arabidopsis

Shoot architecture and flowering time in angiosperms depend on the balanced expression of a large number of flowering time and flower meristem identity genes. Loss-of-function mutations in the Arabidopsis EMBRYONIC FLOWER (EMF) genes cause Arabidopsis to eliminate rosette shoot growth and transform the apical meristem from indeterminate to determinate growth by producing a single terminal flower on all nodes. We have identified the EMF1 gene by positional cloning. The deduced polypeptide has no homology with any protein of known function except a putative protein in the rice genome with which EMF1 shares common motifs that include nuclear localization signals, P-loop, and LXXLL elements. Alteration of EMF1 expression in transgenic plants caused progressive changes in flowering time, shoot determinacy, and inflorescence architecture. EMF1 and its related sequence may belong to a new class of proteins that function as transcriptional regulators of phase transition during shoot development.

Characterization of MADS box genes from hot pepper

The cDNA clone, CanMADS1, was isolated from young flower buds of the hot pepper (Capsicum annuum L.) by screening a cDNA library using the OsMADS1 rice MADS-box gene as a probe. We used a yeast two-hybrid screening method to investigate interaction partners of the protein product of CanMADS1. A MADS-box gene, CanMADS6, was isolated from young flower buds using the region containing the K domain and 15 amino acid residues of the C-terminal region of CanMADS1 as a bait. CanMADS1 and CanMADS6 showed high amino acid sequence similarities to members of the AGL2 subfamily and the SQUA subfamily, respectively. CanMADS1 transcript was expressed in flower buds and fruits, and the transcription signal was the strongest in the stage of the fruit set (2 d after anthesis). CanMADS6 showed the same expression pattern as CanMADS1. CanMADS1 and CanMADS6 were not expressed in leaves. These results suggest that a regulatory role for flower and fruit development of the hot pepper may be accomplished through an interaction of the protein products of the two MADS-box genes, CanMADS1 and CanMADS6.

Antibacterial activity of S-methyl methanethiosulfinate and S-methyl 2-propene-1-thiosulfinate from Chinese chive toward Escherichia coli O157:H7

S-Methyl methanethiosufinate (1) and S-methyl 2-propene-1-thiosulfinate (2) were easily seperated from Chinese chive (Allium tuberosum L.) using simple column chromatography. Both compounds showed significant antibacterial activities against E. coli O-157:H7 including spoilage microorganism in food. Structural assignment was based on Mass and NMR-spectroscopic methods.

Two rice MADS domain proteins interact with OsMADS1

OsMADS1 is a MADS box gene controlling flower development in rice. In order to learn more about the function of OsMADS1, we searched for cellular proteins interacting with OsMADS1 employing the yeast two-hybrid system. Two novel proteins with MADS domains, which were named OsMADS14 and OsMADS15, were isolated from a rice cDNA library. OsMADS14 and -15 are highly homologous to the maize MADS box gene ZAP1 which is an orthologue of the floral homeotic gene APETALA1 (AP1). Interactions among the three MADS domain proteins were confirmed by in vitro experiments using GST-fused OsMADS1 expressed in Escherichia coli and in vitro translated proteins of OsMADS14 and -15. We determined which domains in OsMADS1, -14, and -15 were required for protein-protein interaction employing the two-hybrid system and pull-down experiments. While the K domain was essential for protein-protein interaction, a region preceded by the K domain augmented this interaction. Interestingly, the C-terminal region of OsMADS1 functioned as a transcriptional activation domain in yeast and mammalian cells, while, on the other hand, the C domains of OsMADS14 and -15 exhibited only very weak transcriptional activator functionality, if any at all.

Activating mutation of GS alpha in McCune-Albright syndrome causes skin pigmentation by tyrosinase gene activation on affected melanocytes

McCune-Albright syndrome (MAS) is a sporadic disease characterized by café-au-lait spots, polyostotic fibrous dysplasia and hyperfunctional endocrinopathies. To elucidate the mechanism of skin pigmentation, melanocytes, keratinocytes and fibroblasts were primary cultured from the café-au-lait spot of a MAS patient. Then, mutational analysis and morphologic evaluation were performed. Also, cAMP level and tyrosinase gene expression in cultured cells were determined. Only Gsalpha mutation was found in affected melanocytes and the cAMP level in affected melanocytes was higher than that of normal melanocytes. The mRNA expression of tyrosinase gene was increased in the affected melanocytes. This study suggests that skin pigmentation of MAS results from activating mutation of Gsalpha in melanocytes and the mechanism involves the c-AMP-mediated tyrosinase gene activation.

Truncated form of importin alpha identified in breast cancer cell inhibits nuclear import of p53

Disruption of the function of tumor suppressor proteins occasionally can be dependent on their subcellular localization. In about 40% of the breast cancer tissues, p53 is found in the cytoplasm as opposed to the nucleus, where it resides in normal breast cells. This means that the regulation of subcellular location of p53 is an important mechanism in controlling its function. The transport factors required for the nuclear export of p53 and the mechanisms of their nuclear export have been extensively characterized. However, little is known about the mechanism of nuclear import of p53. p53 contains putative nuclear localization signals (NLSs) which would interact with a nuclear transport factor, importin alpha. In this report we demonstrate that importin alpha binds to NLSI in p53 and mediates the nuclear import of p53. Reverse transcriptase-polymerase chain reaction and sequencing analyses showed that a truncated importin alpha deleted the region encoding the putative NLS-binding domain of p53, suggesting that it could not bind to NLSs of p53 proteins. Binding of importin alpha to p53 was confirmed by using yeast two-hybrid assay. When expressed in CHO-K1 cells, the truncated importin alpha predominantly localized to the cytoplasm. In truncated importin alpha expressing cells, p53 preferentially localized to cytoplasmic sites as well. A significant increase in the p21(waf1/cip1) mRNA level and induction of apoptosis were also observed in importin alpha overexpressing cells. These results strongly suggest that importin alpha functions as a component of the NLS receptor for p53 and mediates nuclear import of p53.

Systemic induction of a Phytolacca insularis antiviral protein gene by mechanical wounding, jasmonic acid, and abscisic acid

We have isolated a gene encoding a ribosome-inactivating protein (RIP) from Phytolacca insularis, designated as P. insularis antiviral protein 2 (PIP2). The PIP2 gene contained an open reading frame encoding a polypeptide of 315 amino acids. The deduced amino acid sequence of PIP2 was similar to those of other RIPs from Phytolacca plants. Recombinant PIP2 was expressed in Escherichia coli and was used to investigate its biological activities. Recombinant PIP2 inhibited protein synthesis in rabbit reticulocyte lysate by inactivating ribosomes through N-glycosidase activity. It also exhibited antiviral activity against tobacco mosaic virus (TMV). Expression of the PIP2 gene was developmentally regulated in leaves and roots of P. insularis. Furthermore, expression of the PIP2 gene was induced in leaves by mechanical wounding. The wound induction of the PIP2 gene was systemic. Expression of the PIP2 gene also increased in leaves in a systemic manner after treatment with jasmonic acid (JA) and abscisic acid (ABA), but not with salicylic acid (SA). These results imply that plants have employed the systemic synthesis of the defensive proteins to protect themselves more efficiently from infecting viruses.

A fast fractal decoding algorithm based on the selection of an initial image

In this correspondence, we show that the number of iterations required for the convergence of the fractal image decoding algorithm can be reduced by selecting a suitable initial image. We consider fractal decoding to have two components, namely, "DC" and "AC". Our initial image is an approximation of the attractor of DC decoding, which is a good estimation of the "range-averaged" image, i.e., the image obtained by replacing all pixel intensities in a given block by the mean value of the block. From the simulation, it is demonstrated that the decoding speed is greatly improved.

Co-administration of toluene and xylene antagonized the testicular toxicity but not the hematopoietic toxicity caused by ethylene glycol monoethyl ether in Sprague-Dawley rats

Occupational painters are exposed to ethylene glycol monoethyl ether (EGEE), a widely used emulsifying solvent known to cause testicular degeneration and bone marrow depression, together with toluene (TOL) and xylene (XYL) as a mixture. In the previous study (Chung et al., Tox. Lett. 104:143, 1999), testicular atrophy caused by EGEE (200 mg/kg) was shown to be antagonized by co-administration of TOL (250 mg/kg) and XYL (500 mg/kg). This study was conducted to provide histological support for the previously observed antagonistic protective effect of TOL + XYL on EGEE inducible testicular toxicity and to determine whether a similar antagonistic effect can be demonstrated against the EGEE derived hematopoietic toxicity. Compared to the extent of seminiferous tubule degeneration caused by EGEE (150 mg/kg, six times per week for 4 weeks), testes of rats given co-administration of TOL (250 mg/kg) + XYL (500 mg/kg) showed dramatically reduced tubular degeneration. Hyperplasia of Leydig cells in the interstitium was observed in both EGEE and EGEE + TOL + XYL-treated rats. Although a minimal dose of EGEE causing testicular atrophy was used, WBC and platelet counts were decreased significantly. In the TOL + XYL-treated control group, the WBC and platelet counts were not decreased. However, the bone marrow depression caused by EGEE was not reversed by the combined administration of TOL + XYL. In all experimental groups (EGEE alone, TOL + XYL, EGEE + TOL + XYL), plasma levels of creatinine and alkaline phosphatase were significantly decreased. In addition to the marked testicular atrophy, EGEE also decreased the weights of adrenal glands and epididymis. In conclusion, while the testicular degeneration caused by EGEE was antagonized by TOL + XYL, the EGEE derived hematopoietic suppression was not reversed.

Determination of the motif responsible for interaction between the rice APETALA1/AGAMOUS-LIKE9 family proteins using a yeast two-hybrid system

A MADS family gene, OsMADS6, was isolated from a rice (Oryza sativa L.) young flower cDNA library using OsAMDS1 as a probe. With this clone, various MADS box genes that encode for protein-to-protein interaction partners of the OsMADS6 protein were isolated by the yeast two-hybrid screening method. On the basis of sequence homology, OsMADS6 and the selected partners can be classified in the APETALA1/AGAMOUS-LIKE9 (AP1/AGL9) family. One of the interaction partners, OsMADS14, was selected for further study. Both genes began expression at early stages of flower development, and their expression was extended into the later stages. In mature flowers the OsMADS6 transcript was detectable in lodicules and also weakly in sterile lemmas and carpels, whereas the OsMADS14 transcript was detectable in sterile lemmas, paleas/lemmas, stamens, and carpels. Using the yeast two-hybrid system, we demonstrated that the region containing of the 109th to 137th amino acid residues of OsMADS6 is indispensable in the interaction with OsMADS14. Site-directed mutation analysis revealed that the four periodical leucine residues within the region are essential for this interaction. Furthermore, it was shown that the 14 amino acid residues located immediately downstream of the K domain enhance the interaction, and that the two leucine residues within this region play an important role in that enhancement.

Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain

APETALA1 (AP1) of Arabidopsis thaliana is a transcription factor controlling flower development. AP2 is a member of the MADS (MCM1, AGAMOUS, DEFICIENS, SRF) superfamily, which plays important roles in differentiation in plants and animals. MADS domains, which function most importantly in DNA binding, are found in all major eukaryotic kingdoms. In plants, MADS domain-containing proteins also possess a region of moderate sequence similarity named the K domain, which is involved in protein-protein interaction. Little is known about the function of a third, highly variable, domain designated the C domain, as it resides at the C terminus of the MADS proteins of plants. Here we report that the C-terminal domain of Arabidopsis thaliana AP1 and its homologues perform a transcriptional activation function. The C-terminal region of AP1 is composed of at least two separable transcriptional activation domains that function synergistically.

Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain

APETALA1 (AP1) of Arabidopsis thaliana is a transcription factor controlling flower development. AP2 is a member of the MADS (MCM1, AGAMOUS, DEFICIENS, SRF) superfamily, which plays important roles in differentiation in plants and animals. MADS domains, which function most importantly in DNA binding, are found in all major eukaryotic kingdoms. In plants, MADS domain-containing proteins also possess a region of moderate sequence similarity named the K domain, which is involved in protein-protein interaction. Little is known about the function of a third, highly variable, domain designated the C domain, as it resides at the C terminus of the MADS proteins of plants. Here we report that the C-terminal domain of Arabidopsis thaliana AP1 and its homologues perform a transcriptional activation function. The C-terminal region of AP1 is composed of at least two separable transcriptional activation domains that function synergistically.

Identification of a rice APETALA3 homologue by yeast two-hybrid screening

A cDNA clone OsMADS16 was isolated from the rice young inflorescence cDNA expression library by the yeast two-hybrid screening method with OsMADS4 as bait. We have previously shown that the OsMADS4 gene is a member of the PI family and that the MADS-box gene is involved in controlling development of the second and third whorls of rice flowers. The sequence comparison indicated that OsMADS16 belongs to the AP3 family. The OsMADS16 protein contains a PI-derived motif, FAFRVVPSQPNLH, that is a conserved sequence in AP3 family genes at the C-terminal region. In addition, OsMADS16 contains a paleoAP3 motif, YGGNHDLRLG, downstream of the PI-derived motif. The paleoAP3 motif is a consensus sequence in the C-terminal region of the AP3 family genes of lower eudicot and magnolid dicot species. RNA blot analysis showed that the OsMADS16 gene was expressed in the second and third whorls, whereas the OsMADS4 transcripts were present in the second, third, and fourth whorls. These expression patterns of the OsMADS16 and OsMADS4 genes are very similar to those of AP3 and PI, respectively. In the yeast two-hybrid system, OsMADS4 interacted only with OsMADS16 among several rice MADS genes investigated, suggesting that OsMADS4 and OsMADS16 function as a heterodimer in specifying sepal and petal identities. The OsMADS16 protein displayed transcription activation ability in yeast, whereas AP3 did not. It was also shown in yeast that OsMADS16 interacted with PI whereas OsMADS4 did not interact with AP3. These differences between OsMADS16 and AP3 indicate that the functions of the AP3 family genes of monocots and dicots diverged during molecular evolution processes of the B function genes. Deletion analysis showed that the 155-200 amino acid region of the OsMADS16 protein plays an important role in the transcription activation ability.

Inhibition of stem cell factor- and nerve growth factor-induced morphological change by wortmannin in mast cells

Recombinant murine stem cell factor (rmSCF) or recombinant murine nerve growth factor (rmNGF) induced the morphological change of large numbers of rat peritoneal mast cells (RPMC). We investigated the role of phosphatidylinositol 3'-kinase (PI3-kinase) in receptors-mediated morphological change in RPMC. Exposure of RPMC to PI3-kinase inhibitor, wortmannin, before the addition of rmSCF and rmNGF antagonized those factors-induced morphological change. These results suggest that the Pl3-kinase is involved in the signal transduction pathway responsible for morphological change following stimulation of rmSCF and rmNGF and that wortmannin blocks these responses.

Expressed sequence tags of radish flower buds and characterization of a CONSTANS LIKE 1 gene

Expressed sequence tag (EST) analysis was conducted for young flower buds of radish plants. Among a total of 66 ESTs examined, 40 showed a significant similarity to previously identified genes. Twenty-eight ESTs were similar to proteins identified in other plants, 11 were similar to eukaryotic proteins other than plants, and one was similar to a prokaryotic protein. Four clones were selected for further studies. EST clone 81, which showed a homology to germin-like proteins was expressed more abundantly in leaves and roots as compared to flower buds. Clone 105 was highly homologous to the translation inhibitor protein and was expressed in all three organs, but the expression level was higher in flower buds and roots. Another EST clone, 133, which shared a significant similarity with the Ran-binding protein, hybridized to two different size transcripts that were detectable only in flower buds. Clone 39 was a homolog of CONSTANS, which is a gene involved in controlling the flowering time in Arabidopsis. The cDNA clone of EST clone 39 containing the entire open reading frame was obtained and designated as RsCOL1 (Raphanus sativus CONSTANS LIKE 1). It was 1049 bp long and contained an open reading frame of 307 amino acid residues (calculated molecular mass = 33.1 kDa). The RsCOL1 protein contained two putative zinc finger motifs in the amino terminal region which were 59% identical to the corresponding region of the Arabidopsis CO protein. The radish protein also contained a predicted nuclear localization domain in the carboxyl terminal region which was 87% identical to the corresponding region of CO. DNA blot analysis revealed that the radish genome contained several genes similar to RsCOL1. RNA blot analysis showed that RsCOL1 was strongly expressed in flower buds at the early bolting stage, and the expression level declined as the flower bud matured. The transcript was also detectable in leaves and roots. In mature flowers, the RsCOL1 transcript was present primarily in carpels.

Inhibitory effect of mast cell-mediated immediate-type allergic reactions in rats by spirulina

We investigated the effect of spirulina on mast cell-mediated immediate-type allergic reactions. Spirulina dose-dependently inhibited the systemic allergic reaction induced by compound 48/80 in rats. Spirulina inhibited compound 48/80-induced allergic reaction 100% with doses of 100-1000 microg/g body weight, i.p. Spirulina (10-1000 microg/g body weight, i.p.) also significantly inhibited local allergic reaction activated by anti-dinitrophenyl (DNP) IgE. When rats were pretreated with spirulina at a concentration ranging from 0.01 to 1000 microg/g body weight, i.p., the serum histamine levels were reduced in a dose-dependent manner. Spirulina (0.001 to 10 microg/mL) dose-dependently inhibited histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. The level of cyclic AMP in RPMC, when spirulina (10 microg/mL) was added, transiently and significantly increased about 70-fold at 10 sec compared with that of control cells. Moreover, spirulina (10 microg/mL) had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production. These results indicate that spirulina inhibits mast cell-mediated immediate-type allergic reactions in vivo and in vitro.

Cloning of a cDNA encoding phospholipase D from Pimpinella brachycarpa

Phospholipase D (PLD, EC 3.1.4.4) has been known to be related to various cellular processes in plants. To gain an understanding of the property of the enzyme in Pimpinella brachycarpa, the cDNA of the enzyme was isolated by PCR with degenerate primers, cDNA library screening, and 5' RACE. The full-length PLD cDNA is 2859 bp long and contains an open reading frame of 2424 bp coding for a polypeptide of 808 amino acids. The deduced enzyme has a calculated molecular mass of 91.7 kDa and pI of 5.86. The percent identity and similarity values of P. brachycarpa PLD with those of other PLDs in plants are 70 approximately 78 and 84 approximately 95, respectively. It was identified that PLD from P. brachycarpa has HQKIVVVD and HAKMMIVD sequences which were homologous with a duplicated HXKXXXXD motif that has been conserved in PLDs from plants, animals, and yeast. Based on the analysis of amino acid similarity, it is believed that PLD from P. brachycarpa is an alpha form which is distinct from PLD beta reported recently. The N-terminus is homologous to the C2 domain which is present in a number of different proteins involved in signal transduction and membrane trafficking in animals. Southern and northern blot analyses indicated that PLD was expressed from one copy of PLD gene in the genome of P. brachycarpa.

Expression of a cDNA encoding Phytolacca insularis antiviral protein confers virus resistance on transgenic potato plants

To develop an antiviral agent and virus-resistant plants, a cDNA clone encoding Phytolacca insularis antiviral protein (PIP) was isolated from a cDNA library constructed with poly(A)+ RNA purified from leaves of P. insularis. The PIP cDNA contains an open reading frame encoding 307 amino acids. The deduced amino acid sequence includes a putative signal sequence of 22 amino acids at the N-terminus. The amino acid sequence of PIP shares 84% homology with that of the pokeweed antiviral protein (PAP). In addition, the mature PIP exhibits the conserved putative active site found in other ribosome-inactivating proteins (RIPs). Recombinant PIP (rPIP) synthesized in Escherichia coli inhibits protein synthesis in vitro in rabbit reticulocyte lysate through the N-glycosidase activity in a similar manner with other RIPs. Local lesion assays with purified rPIP revealed that it inhibits infection of various viruses to plants. Transgenic potato plants expressing the PIP cDNA under the control of the cauliflower mosaic virus 35S promoter are resistant to viruses, such as potato virus X, potato virus Y, and potato leafroll virus. These results suggest that the PIP cDNA could be used for the development of an antiviral agent and transgenic plants resistant against a broad spectrum of plant viruses infecting through both mechanical and aphid transmission.

Reproductive toxicity of 2-bromopropane in Sprague Dawley rats

OBJECTIVES

In an effort to clarify the mass intoxication of workers at an electronic company in Korea, the possible causative chemical for reproductive toxicity, 2-bromopropane (2BP), was investigated.

METHODS

2BP was tested through the use of repeated dose experiments among male Sprague Dawley rats. Ten rats were assigned to each treatment group. Vehicle control olive oil and 2BP concentrations of 125 mg/kg, 250 mg/kg, and 500 mg/kg were injected into the intraperitoneum on 28 consecutive days.

RESULTS

The rats showed significant decreases in body weight depending on the 2BP dose. The right and left testes showed typical weight loss depending on the dose of 2BP. The red blood cells, hemoglobin, and hematocrit showed some degree of decline with the high dose. The amount of hemoglobin, the mean platelet volume, the number of white blood cells, and the number of lymphocytes decreased significantly with the high dose, while the number of granulocytes and monocytes had a tendency to decrease depending on the dose of 2BP. The histopathology of the testes treated with the middle and high 2BP dose showed a typical patch appearance with severely depleted atrophic tubules, exhibiting germ cell necrosis of spermatogonia and spermatocytes in the seminiferous tubules. Leydig cell hyperplasia or hypertrophy in the interstitial tissue was also noticeable. The epididymis showed some degree of atrophy with vacuolization of the epididymal epithelium.

CONCLUSIONS

The testes are the main target organs tested for 2BP toxicity. 2BP also affect the hematopoietic system and thus induces leukopenia and normocytic anemia. Besides the reproductive organs and the hematopoietic system, no significant toxicity has been found.

Effects of 2-bromopropane on the female reproductive function in Sprague-Dawley rats

2-Bromopropane (2BP) has been implicated to be the reason for the mass intoxication of workers at an electronic company in Korea. A case series study indicated that 2BP was the possible causative chemical for reproductive toxicity, causing severe anemia accompanied by amenorrhea among female workers, and azoospermia or oligospermia among male workers. To clarify the effect of 2BP on the female reproductive function, repeated doses of 2BP were tested on female Sprague-Dawley rats for 21 days. Ten rats were assigned to each treatment group. The rats were maintained in a 12 hr: 12 hr light-dark cycle and vaginal smears were monitored daily for 3 cycles. After the rats had completed 3 estrous cycles, vehicle control olive oil, 300 mg, 600 mg, and 900 mg/kg of 2BP were injected into intraperitoneum for 14 days. The female rats were then mated with male rats on a 1:1 ratio basis. The treatment continued for an additional 7 days. Rats treated with 2BP experienced a significant decrease in body weight gain depending on the dose of 2BP. The estrous cycles of the rats continued at a normal duration of time before the initiation of treatment, showing 4.32 days for the control group, 4.79 days for the low dose, 4.63 days for the middle dose, and 4.75 days of estrous cycle for the high dose group. 2BP treatment, however, induced a significant delay of the estrous cycle in the high dose treated group, showing 11.1 +/- 3.82 days of the estrous cycle. 2BP decreased the fertility and tended to decrease in the number of pups born, depending on the dose. A 900 mg/kg treatment of 2BP decreased ovarian weight, but 2BP did not affect the length of gestation. Our results indicated that 2BP seemed to be the causative agent for amenorrhea observed in female workers.

Structure and expression of the AWI 31 gene specifically induced by wounding in Arabidopsis thaliana

Differential screening of an Arabidopsis cDNA library constructed from the plant tissues harvested 1 h after wounding resulted in the isolation of wound-inducible cDNA clones (Kim et al., 1994). The cDNA clones could be broadly classified into two groups according to the expression time of their transcripts. Nine clones from the 10 different wound-inducible cDNAs were rapidly induced, reaching a maximum level in approximately 1-1.5 h and then were progressively reduced after wounding. The cDNA clone AWI 31 showed steady accumulation of the transcripts and reached the maximum value at a later time point of 2.5 h and then started to decline. The corresponding gene of the AWI 31 in which the coding region was interrupted by an intron, had an open reading frame that predicted a protein of 386 amino acids. However, the gene product did not show any significant homology to other known proteins in the database. Northern hybridization study using the cDNA probe revealed that the gene was not regulated by other environmental stresses such as drought, high salt, low temperature, or a DPE herbicide treatment, indicating that the cDNA clone AWI 31 was specifically induced by wounding.

Korean analytical quality assurance (KAQUA) program for biological monitoring

The Korean analytical quality assurance (KAQUA) program on biological monitoring was performed by the Industrial Health Research Institute in Korea in spring, 1995. The object of the KAQUA program is to improve the analysis capability for the biological monitoring of hazardous chemicals and to confirm the reliability of data from each laboratory. The items chosen for the first round were analyses of lead in blood (PbB) and of hippuric acid in urine (HAU). Eighty-eight laboratories in Korea participated in this program. Two levels of samples, randomly chosen among six levels for each item, were sent to the participants. The consensus value from participants and reference laboratories was determined by statistical analysis and used as a reference value. The tolerance range was +/-15% (+/-6 micrograms/dl for PbB below 40 micrograms/dl) of the reference value. The mean proficiency rate of analytical data increased dramatically in the first round compared with a pre-round that was provided as part of a training course for participants before performing the first round. The mean proficiency rate of PbB was 69% at pre-round and increased at 91% at the first round; for HAU the increase was from 58% to 88%. Not only the analytical results but also raw data were reviewed to find problems which might have arisen during the analytical process. Re-education courses provided after final evaluation of each participant by means of telephone discussion, correspondence course, and experimental practice, were helpful in achieving the purpose of the analytical quality assurance program.

Human chorionic gonadotropin induces nitric oxide synthase mRNA in mouse peritoneal macrophages

We examined the effects of human chorionic gonadotropin (hCG) on the production of nitric oxide (NO) by mouse peritoneal macrophages. hCG had no effect on NO synthesis by itself, whereas recombinant interferon-gamma (rIFN-gamma) alone had modest activity. When hCG was used in combination with rIFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of hCG on NO synthesis was shown at 6 h after treatment with rIFN-gamma. This increase in NO synthesis was reflected as increased amount of inducible NO synthase (iNOS) mRNA. NG-monomethyl-L-arginine, and arginase inhibited rIFN-gamma-plus-hCG-induced NO production. On the basis of these observations, we conclude that hCG activates expression of iNOS mRNA in mouse peritoneal macrophages accompanied by NO accumulation via pathway dependent on L-arginine in the culture medium.

Lead concentrations in blood among the general population of Korea

The purpose of this survey was to obtain information on the overall blood lead concentrations of the Korean population due to environmental exposure. Five hundred and twenty-five Korean adults from four provinces who had no previous occupational exposure to lead were chosen by random sampling to represent the general (normal) population. Blood lead determinations were performed by atomic absorption spectrometry with a graphite furnace. Interlaboratory quality control for analysis of blood lead was carried out in seven laboratories in Korea and Europe. The geometric mean were 6.36 micrograms/dl for males and 5.09 micrograms/dl for females. There was no correlation between blood lead concentration and age. The mean concentration of blood lead in smokers was higher than that in nonsmokers (P < 0.0005). The mean blood lead concentration in male nonsmokers was higher than that in female nonsmokers (P < 0.0005). Differences in mean blood lead values according to residential area were observed, and this result showed good agreement with the results of ambient monitoring.

Clinical and immunologic evaluations of reactive dye-exposed workers

To evaluate type 1 hypersensitivity to reactive dyes, its prevalence, and its relationship to respiratory dysfunction, we studied clinical and immunologic features, including skin prick tests. RAST, and bronchoprovocation tests, of 309 employees working in a reactive-dye industry. Our survey revealed that 78 (25.2%) employees had work-related lower respiratory symptoms associated with or without nasal, skin, or eye symptoms. Among these employees, 38 (48.7%) had nonspecific bronchial reactivity. Thirteen demonstrated immediate (6), dual (6), or late only (1) asthmatic responses after inhalation of four kinds of reactive-dye solutions. Twenty-five employees demonstrated immediate skin responses to black GR dye, and 21 reacted to orange 3R. Fifty-three employees (17%) had specific serum IgE antibody against black GR and orange 3R-human serum albumin conjugate. Specific IgE was detected more frequently in symptomatic employees (30%) and smokers (100%). No association was found between atopy and specific IgE binding. The RAST-inhibition tests of black GR revealed significant inhibitions by black GR-human serum albumin conjugate and minimal inhibitions by unconjugated black GR. Orange 3R RAST-inhibition tests revealed significant inhibitions by conjugated forms of black GR and orange 3R and some inhibitions by two unconjugated dyes, suggesting an immunologic cross-reactivity between these dyes. These findings suggested that reactive dyes could induce immunologic responses, most likely IgE-mediated.