• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1417-1424
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• 2011

This study was conducted to assess the relation between threonine (Thr) oxidation rate and threonine efficiency on rat and chicken fed with graded levels of protein and threonine. The increase in threonine content from 0.28 to 0.72% in a diet containing 12.0% crude protein (CP) caused a gradual increase in threonine dehydrogenase (TDG) activity in rat liver. Similar, but more pronounced results were observed after 18.0% CP in the diet. Both protein levels in combination with the highest level of threonine supplementation increased liver TDG activity significantly, indicating enhanced threonine catabolism. Parameters of efficiency of threonine utilization calculated from parallel nitrogen balance studies decreased significantly and indicated threonine oversupply after a maximum of threonine supplementation. At the lower levels of threonine addition the efficiency of threonine utilization was not significantly changed. In the chicken liver up to 0.60% true digestible threonine (dThr) in the 18.5% CP diet produced no effect on the TDG activity. However, TDG activity in the liver was elevated by the diet containing 22.5% CP (0.60% dThr) and the efficiency of threonine utilization decreased, indicating the end of threonine limiting range. In conclusion, the in vitro TDG activity in the liver of rat and growing chicken has an indicator function for the dietary supply of threonine.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.69-76
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• 2014

This study was carried out to evaluate the relationship between threonine (Thr) efficiency and Thr dehydrogenase (TDG) activity as an indicator of Thr oxidation on chicks fed with levels of diets (CP [17.5% and 21.5%] and Thr [3.8 and 4.7 g/100 g CP]; glycine [Gly][0.64% and 0.98%] and true digestible Thr [dThr] [0.45% and 0.60%]). Calculation of the Thr efficiency was based on N-balance data and an exponential N-utilization model, and TDG activity was determined as accumulation of aminoacetone and Gly during incubation of hepatic mitochondria. This study found that in the liver of chicks who received a diet containing up to 0.79% Thr (4.7 g Thr/100 g of CP) in the 17.5% CP diet, no significant (p>0.05) effect on TDG activity was observed. However, significantly (p = 0.014) increased TDG activity was observed with a diet containing 21.5% CP (4.7 g Thr/100 g of CP) and the efficiency of Thr utilization showed a significant (p = 0.001) decrease, indicating the end of the Thr limiting range. No significant (p>0.05) effect on the total TDG activity and accumulation of Gly was observed with addition of Gly to a diet containing 0.45% dThr. In addition, addition of Gly to a diet containing 0.60% dThr also did not result in a change in accumulation of Gly. Due to an increase in accumulation of aminoacetone, an elevated effect on total TDG activity was also observed. No significant (p>0.05) reduction in the efficiency of Thr utilization was observed after addition of Gly at the level of 0.45% dThr. However, significantly (p<0.001) reduced efficiency of Thr utilization was observed after addition of Gly at the level of 0.60% dThr. Collectively, we found that TDG was stimulated not only by addition of Thr and protein to the diet, but also by addition of Gly, and efficiency of Thr utilization was favorably affected by addition of Gly at the level near to the optimal Thr concentration. In addition, no metabolic requirement of Gly through the TDG pathway was observed with almost the same accumulation of Gly and a slight increase in TDG activity by addition of Gly. Thus, our findings suggest that determination of TDG activity and parameter of efficiency of Thr utilization may be useful for evaluation of dietary Thr level.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.21-29
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• 1998

Four feeding trials with 260 pigs were conducted to evaluate the effects of supplementing the diet with different amino acids on growth performance and blood metabolites for weanling, growing and finishing pigs. One hundred twenty weanling pigs (Exp. 1, BW 8 kg), eighty growing pigs (Exp. 2. BW 20 kg), thirty growing pigs (Exp. 3, BW 29 kg) and thirty finishing pigs (Exp. 4, BW 50 kg) were randomly allotted to different dietary treatments according to sex and body weight. Pigs weight and feed consumption were measured at initiation and termination of each trial with 4 weeks. At the end of trial, blood samples from three pigs selected in each pen (Exp. 1) and each pig (Exp. 2) were obtained to determine the level of blood urea nitrogen, glucose, insulin and cortisol in the serum. In Exp. 1, pigs fed diet supplemented both with lysine and methionine had the best feed conversion ratio (p < 0.05), but no significant differences (p > 0.05) were observed in ADG and ADFI. Pigs receiving control diet obtained the obtained the optimal ADG (p < 0.05), ADFI (p < 0.05) and F/G for the whole period. No differences were detected in serum glucose, insulin and cortisol concentrations. In Exp. 2, pigs receiving the control diet exhibited the lowest serum urea nitrogen (p < 0.05), ADG, F/G and serum insulin concentration increased linearly (p < 0.05) with the inclusion of lysine, methionine, threonine and tryptophan in diets. No significant differences (p > 0.05) were detected for glucose and cortisol content in pigs serum among dietary treatments. In Exp. 3 and 4, pigs growth rate increased linearly (p < 0.01), and feed conversion efficiency was also improves by addition of lysine, methionine, threonine and tryptophan. In conclusion, pigs fed diets supplemented with lysine, methionine, threonine and tryptophan together obtained optimal growth performance in growing and finishing periods.

• Korean Journal of Head & Neck Oncology
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• v.21 no.2
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• pp.158-164
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• 2005

Purpose: The serine/threonine kinase Akt was described to inhibit apoptosis in cancer. This study was to examine the effect of Gleevec on head and neck squamous cell carcinoma(HNSCC) through the mechanism of Akt. Experimental Design: Gleevec was introduced into the HNSCC cell lines UMSCC10B, HN12 and HN30 in a range of concentrations. Cell viability was assessed by clonogenic survival analysis. Targets of Gleevec(PDGFR, c-Kit, and c-Abl) were evaluated by Western blot. HNSCC tissue samples were stained for PDGFR, c-Kit and phosphorylated Akt. Akt phosphorylation following Gleevec treatment was assessed using Western blot. Akt siRNA was used to as the positive control. Results: Colony forming efficiency decreased with an increase in concentration of Gleevec. Expressions of PDGFR, c-Kit, and c-Abl were observed in HNSCC cells. Immunohistochemistry confirmed high expression of PDGFR, c-Kit, and p-Akt in human HNSCC tissues. Akt kinase activity was significantly inhibited with increasing concentration of Gleevec in HNSCC cells, and near complete dephosphorylation of Akt was observed at $6{\mu}M$ of Gleevec in the UMSCC10B and HN30 cell lines. Conclusions: Gleevec at clinically comparable concentrations caused a dose dependant decrease in HNSCC survival. The decreased cell survival was related to the inhibition of Akt kinase activity and dephosphorylation of Akt. Akt signaling pathway may be a relevant target for Gleevec in treating HNSCC.

• Journal of Animal Science and Technology
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• v.62 no.6
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• pp.840-853
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• 2020

The present study was conducted to investigate the effect of a multi-protease on production indicators of broiler chickens fed a crude protein and amino acid deficient-diets for 35 days immediately after hatch. A total of 448 one-day-old Ross 308 male broiler chicks were allocated in a completely randomized design into one of eight dietary treatments (positive control [PC], negative control [NC: minus 0.5% from PC, and minus 2% of lysine, methionine, threonine and methionine plus cysteine], extreme negative control [ENC: minus 1% from PC, minus 4% of lysine, methionine, threonine and methionine plus cysteine], and plus multi-protease 150 or 300 g per ton [e. g., PC-150]; PC, PC-150, NC, NC-150, NC-300, ENC, ENC-150, ENC-300) to give eight replicates with seven birds in a battery cage. Body weight, average daily gain, average daily feed intake, feed conversion ratio, and mortality were measured every week. Carcass traits, proximate analysis of breast meat, and ileum digestibility were analyzed on day 21 and 35. Feeding a multi-protease (i.e., more than 150 g/ton) for 35 days immediately after hatching improved feed efficiency and ileum digestibility (i.e., dry matter, crude protein, and energy) compared to their counterparts (i.e., diets without multi-protease: PC, NC, and ENC). In conclusion, our results indicated that broiler chickens fed nutrients deficient-diet (i.e., crude protein and amino acids) supplemented a multi-protease had an ability to compensate and (or) improve their growth performance commensurate with increased ileal digestibility for 35 days immediately after hatch.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.126-132
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• 1991

Nutritional factors affecting the urinary excretion of acid-soluble peptides(ASP) in rats were studied using protein-free diet, gluten diet, casein diet, and gluten supplemented with lysine and threonine(GLT) diet. The content of urinary ASP was lowest in protein-free diet group among the four kinds of diets above. But the amino acid pattern of urinary ASP in the four dietary groups were similar each other, suggesting that urinary ASP is mainly from endogenous origin under these nutritional conditions. The efficiency of dietary protein utilization was significantly lower in gluten diet than that of casein diet or GLT diet. Those findings suggest that the rate of urinary excretion of ASP-form amino acids can be employed as an index of protein metabolism, particularly as a simple index in the assessing the status of protein nutrition.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.709-711
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• 2001

To elucidate the putative role of the amido group in the metal binding of the fuculose-1-phosphate aldolase from Methanococcus jannaschii, we have examined a potential targen using site-directed mutagenesis. The replacement of asparagine 25 with leucine or threonine was shown to have a negative effect, not only on catlytic efficiency, but also on substrage recognition as well. The Hill coefficient values yeilded a value of =1. All metals used with the wild-type aldolases exhibited higher activity than that of the mutants. The spectra of the mutants were quite different from the wild-type aldolase. A highly conserved amino acid of asparagine 25 in a related family of aldolase odes not appear to provide sufficient evidence for evolution.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.407-412
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• 2009

In this study, a rapid and efficient concentrating procedure that can be used for detecting viruses in vegetables was developed. The Sabin strain of poliovirus type 1 was used to evaluate the efficiency of virus recovery. The procedure included: (a) elution with 0.25 M threonine-0.3 M NaCl pH 9.5; (b) polyethylene glycol (PEG) 8000 precipitation; (c) chloroform extraction; (d) 2$^{nd}$ PEG precipitation; (f) RNA extraction; (g) reverse transcription-polymerase chain reaction (RT-PCR) combined with semi-nested PCR. The overall recoveries by elution/concentration were 29.0% from cabbage and 13.7% from lettuce. The whole procedure usually takes 18 hr. The overall detection sensitivity was 100 RT-PCR units of genogroup II norovirus (GII NoV)/25 g cabbage and 100 RT-PCR units of GII NoV/10 g lettuce. The virus detecting method developed in this study should facilitate the detection of low levels of NoV in cabbage and lettuce.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.363-367
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• 1984

Conditions for efficient formation and regeneration of protoplasts of Streptococcus lactis ATCC 11454 were investigated. Addition of 20mM DL-threonine into growth medium, growth phase and lysozyme concentration had significant effects on protoplast formation. Approximately, 20% regeneration efficiency was obtained by optimizing the medium composition and modifying the plating procedure.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.3
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• pp.309-313
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• 1996

This experiment was carried out to investigate the effect of rumen-protected lysine (RPLys) on growth rate, feed efficiency and plasma amino acid concentrations in sheep. RPLys was supplemented at the level of 0% ($T_1$), 0.2% ($T_2$) and 0.4% ($T_3$) of total DMI with 24 sheep in a 56 day feeding trial. The results are summarized as follows: 1. live weight gain of sheep in groups $T_1$, $T_2$ and $T_3$ was 219, 216 and 244 g/d, and was significantly (p < 0.05) higher for $T_3$ through the entire experiment. 2. Feed intake was not affected by RPLys supplementation. 3. The group fed $T_3$ had a significantly (p < 0.05) better feed efficiency than the groups fed $T_1$ and $T_3$. The response of $T_3$ was higher in growing period II of feeding low protein basal diet than in period I. 4. Plasma lysine concentrations tended to be higher with supplementing RPLys, but there were no differences between $T_2$ and $T_3$. 5. Supplementing RPLys in the diets increased plasma concentrations of arginine, asparagines, threonine, serine, valine and leucine compared with sheep receiving no RPLys. In contrast, plasma histidine was lower in sheep fed the supplementing RPLys than fed the diet $T_1$ with significant (p < 0.05) difference.