The Hartnup phenotype: Mendelian transport disorder, multifactorial disease.

The Hartnup mutation affects an amino acid transport system of intestine and kidney used by a large group of neutral charge alpha-amino acids (six essential and several nonessential). We compared developmental outcomes and medical histories of 21 Hartnup subjects, identified through newborn screening, with those of 19 control sibs. We found no significant differences in means of growth percentiles and IQ scores between Hartnup and control groups (but all low academic performance scores were found in the Hartnup group, and various skin lesions occurred in five Hartnup subjects), no significant difference between means of the summed plasma values for amino acids affected by the Hartnup gene in Hartnup and control groups, two Hartnup subjects with clinical manifestations--impaired somatic growth and IQ in one, impaired growth and a "pellagrin" episode in the other--who had the lowest summed plasma amino acid values in the Hartnup group; the corresponding values for their sibs were the low outliers in the control group, and two tissue-specific forms of the Hartnup (transport) phenotype: renal and intestinal involvement (15 families) and renal involvement alone (one family), both forms having been inherited as autosomal recessives (the symptomatic probands had the usual form). Whereas deficient activity of the "Hartnup" transport system is monogenic, the associated plasma amino acid value (measured genotype) is polygenic. The latter describes the parameter of homeostasis and liability to disease. Cause of Hartnup disease is multifactorial.     

1-Aminocyclopentane-1,2,4-tricarboxylic acids screening on glutamatergic and serotonergic systems

Enantiopure constrained 1-aminocyclopentane-1,2,4-tricarboxylic acids containing the glutamic acid skeleton were prepared as two diastereomers characterized by having the carboxylic groups in position two and four cis-oriented to each other and trans with respect to 1-carboxylic group and all cis-oriented carboxylic groups, respectively. A biochemical screening of activity of the above amino acids was investigated on glutamate and 5-HT receptors to find a possible metabotropic agonist, acting on the serotoninergic system.     

Evaluation of amino acid profile in serum of patients with Covid-19 for providing a new treatment strategy

BackgroundAmino acids have an important role in metabolism and may affect COVID-19-related outcomes. In our study, the amino acid serum level of hospitalized COVID19 patients was evaluated to determine a new treatment strategy.MethodsThe amino acid profile covering 43 amino acids in 68 subjects, comprising 30 (14 men and 16 women) controls and 38 (16 men and 22 women) COVID-19 patients, were examined. The amino acid profiles of the participants were screened by LC-MS/MS.ResultsCompared with the control group, serum levels of 27 amino acids increased in the patient group. Alpha-aminopimelic acid, sarcosine, and hydroxyproline amino acids were considerably higher in the control group than in the patient group (p<0.0001). There was no notable difference among control group and the case group for 13 amino acids (p≥0.05). A significant positive correlation was seen among the control and the patient groups in the mean amino acid values (r=0.937; p<0.0001).ConclusionsThese results postulated a clear picture on the serum levels of amino acid in the COVID-19 patients. Serum amino acids measured in hospitalized COVID-19 patients can explain the patient''s metabolic status during the disease.     

Biochemical and heart adaptations to physical training and supplementation with amino acids

This study evaluated the role of amino acids supplementation on the heart's adaptation under extensive training conditions. Sixty active athletes (bicyclists and swimmers) were separated into 2 groups: 30 were given amino acid mixture (1 g per 10 kg of body weight) for a period of 1 month, and the other 30 were given placebo for the same duration (control group). In the same time period, 20 subjects of similar age not engaged in physical training or sports activities were used as the additional control group. Blood concentrations of alanine transaminase (ALT), asparagine transaminase, lactate dehydrogenase (LDH), gamma-glutamil transpeptidase, alkaline phosphatase (ALP), amylase, triglycerides, albumin, interleukin-6 (IL-6), and interleukin-10 (IL-10) were determined for all subjects before and after the intervention period. Concentrations of LDH and ALP were increased, but concentrations of ALT, albumin, and triglycerides were decreased in the blood of trained athletes compared with healthy subjects not engaged in sports activities. In the athletes, some increases in IL-6 levels were noted; however, they were significantly (p < 0.05) lower than in patients with myocardiodystrophy. The values of IL-10 in athletes were higher than concentrations of IL-10 in patients with myocardiodystrophy but still lower than the normal values. The inhibition of IL-10 in blood may play an important role in the induction of apoptosis in cells of the heart muscle. After amino acid supplementation, the athletes' values for albumin, triglycerides, IL-10, LDH, and ALP were significantly increased compared with the post-placebo control groups. Enzyme activities of other enzymes remained unchanged in all groups. Histological data from a secondary study of actual heart tissue showed that the amino acids supplementation may have inhibiting effects on myocardial apoptosis. The criteria of efficiency of the amino acids supplementation were defined by the albumin, IL-6, and IL-10 concentrations.     

Follow the leader: preference for specific amino acids directly following the initial methionine in proteins of different organisms

It is well established that the vast majority of proteins of all taxonomical groups and species are initiated by an AUG codon, translated into the amino acid methionine (Met). Many attempts were made to evaluate the importance of the sequences surrounding the initiation codon, mostly focusing on the RNA sequence. However, the role and importance of the amino acids following the initiating Met residue were rarely investigated, mostly in bacteria and fungi. Herein, we computationally examined the protein sequences of all major taxonomical groups represented in the Swiss-Prot database, and evaluated the preference of each group to specific amino acids at the positions directly following the initial Met. The results indicate that there is a species-specific preference for the second amino acid of the majority of protein sequences. Interestingly, the preference for a certain amino acid at the second position changes throughout evolution from lysine in prokaryotes, through serine in lower eukaryotes, to alanine in higher plants and animals.     

Neuropsychological and biochemical investigations in heterozygotes for phenylketonuria during ingestion of high dose aspartame (a sweetener containing phenylalanine)

Aspartame, a high intensity sweetener, is used extensively worldwide in over 5,000 products. Upon ingestion, aspartame is completely metabolized to two amino acids and methanol (approximately 50% phenylalanine, 40% aspartic acid, and 10% methanol). The effects of aspartame on cognitive function, electroencephalograms (EEGs) and biochemical parameters were evaluated in 48 adult (21 men, 27 women) heterozygotes for phenylketonuria (PKUH). PKUH subjects whose carrier status had been proven by DNA analysis ingested aspartame (either 15 or 45 mg/kg/day) and placebo for 12 weeks on each treatment using a randomized, doubleblind, placebo-controlled, crossover study. A computerized battery of neuropsychological tests was administered at baseline weeks -2 and -1, and during treatment at weeks 6, 12, 18, and 24. Samples for plasma amino acids and urinary organic acids were also collected during these visits. EEGs were evaluated by conventional and spectral analysis at baseline week -1 and treatment weeks 12 and 24. The results of the neuropsychological tests demonstrated that aspartame had no effect on cognitive function. Plasma phenylalanine significantly increased, within the normal range for PKUH, at 1 and 3 h following the morning dose of aspartame in the group receiving the 45 mg/kg per day dose only. There were no significant differences in the conventional or spectral EEG analyses, urinary organic acid concentrations, and adverse experiences when aspartame was compared with placebo. This study reaffirms the safety of aspartame in PKUH and refutes the speculation that aspartame affects cognitive performance, EEGs, and urinary organic acids.     

Increased Hippocampal Afterdischarge Threshold in Ketogenic Diet is Accompanied by Enhanced Kynurenine Pathway Activity

The efficacy of a ketogenic diet (KD) in controlling seizure has been shown in many experimental and clinical studies, however, its mechanism of action still needs further clarification. The major goal of the present study was to investigate the influence of the commercially available KD and caloric restriction (CR) on the hippocampal afterdischarge (AD) threshold in rats, and concomitant biochemical changes, specifically concerning the kynurenine pathway, in plasma and the hippocampus. As expected, the rats on the KD showed higher AD threshold accompanied by increased plasma β-hydroxybutyrate level compared to the control group and the CR rats. This group presented also lowered tryptophan and elevated kynurenic acid levels in plasma with similar changes in the hippocampus. Moreover, the KD rats showed decreased levels of branched chain amino acids (BCAA) and aromatic amino acids (AAA) in plasma and the hippocampus. No regular biochemical changes were observed in the CR group. Our results are analogous to those detected after single administrations of fatty acids and valproic acid in our previous studies, specifically to an increase in the kynurenine pathway activity and changes in peripheral and central BCAA and AAA levels. This suggests that the anticonvulsant effect of the KD may be at least partially associated with those observed biochemical alternations.

     

The effect of consuming different proportions of hummer fish on biochemical and histopathological changes of hyperglycemic rats

Hammour fish (grouper fish) are known to be of great nutritional value for human consumption, as their protein has a high biological value and contains all the essential amino acids. Grouper fish are also a good source of minerals, vitamins, and fats that contain essential fatty acids. Thus, the current study aims to know the effect of different proportion of hummer fish on biochemical and histopathological changes of hyperglycemic rats. Twenty-four (24) Sprague Dawley-strain male albino rats, which weighed 150 ± 10 g, were divided into four groups. One group served as the negative control (normal), while the others were rendered diabetic using alloxan. One of the diabetic groups was considered the positive control and fed a standard diet, whereas the remaining two groups were fed with a 20% and 25% hammour fish diet for 28 days. At the end of the experiment, blood samples were taken from all the rats, and their organs were removed and subjected to biochemical analysis. The results indicated that the group fed with the 25% hammour fish diet exhibited significantly lower levels of liver, kidney, and heart damage, along with lower levels of serum glucose, total cholesterol, triglycerides, LDL, GOT, GPT and ALP, as compared to the positive control. The urea and creatinine levels were significantly higher for the rats that were fed the 20% hammour fish diet than for those in the positive control. The histopathological study of the heart showed a slight improvement of the heart tissues with the increase of hammour fish intake compare to the positive control, while kidney of rat from group 4, which were fed 25% hammour fish, showed granularity of epithelial lining glomerular tufts.     

Amino Acid Interaction with and Adsorption on Clays: FT-IR and Mössbauer Spectroscopy and X-ray Diffractometry Investigations

In the present paper, the adsorption of amino acids (Ala, Met, Gln, Cys, Asp, Lys, His) on clays (bentonite, kaolinite) was studied at different pH (3.00, 6.00, 8.00). The amino acids were dissolved in seawater, which contains the major elements. There were two main findings in this study. First, amino acids with a charged R group (Asp, Lys, His) and Cys were adsorbed on clays more than Ala, Met and Gln (uncharged R groups). However, 74% of the amino acids in the proteins of modern organisms have uncharged R groups. These results raise some questions about the role of minerals in providing a prebiotic concentration mechanism for amino acids. Several mechanisms are also discussed that could produce peptide with a greater proportion of amino acids with uncharged R groups. Second, Cys could play an important role in prebiotic chemistry besides participating in the structure of peptides/proteins. The FT-IR spectra showed that the adsorption of amino acids on the clays occurs through the amine group. However, the Cys/clay interaction occurs through the sulfhydryl and amine groups. X-ray diffractometry showed that pH affects the bentonite interlayer, and at pH 3.00 the expansion of Cys/bentonite was greater than that of the samples of ethylene glycol/bentonite saturated with Mg. The Mössbauer spectrum for the sample with absorbed Cys showed a large increase (～20%) in ferrous ions. This means that Cys was able to partially reduce iron present in bentonite. This result is similar to that which occurs with aconitase where the ferric ions are reduced to Fe 2.5.     

开放流水养殖模式下暂养时间对黄颡鱼肌肉品质和营养价值的影响

文章旨在探索开放流水养殖模式下,暂养对黄颡鱼(Pelteobagrus fulvidraco)肌肉品质和营养价值的影响。试验选用处于快速生长期的大规格鱼种(15.69±2.28) g黄颡鱼为试验对象,随机分为4组,分别暂养0(对照组)、20d、30d和40d,每组3个重复。试验期间投喂黄颡鱼配合饲料,在养殖过程中定期测量水质。在试验结束后对其生长性能、血清生化指标、肌肉氨基酸、脂肪酸组成及质构特性进行比较。结果显示:(1)暂养期间试验池的水质氨态氮含量在0.03—0.05 mg/L,亚硝态氮含量均在0.01 mg/L,溶氧水平均超过9.0 mg/L。(2)暂养时间延长,黄颡鱼末体重和增重率呈上升趋势,特定生长率呈下降趋势,各组间差异显著(P<0.05);暂养20d、30d和40d组的成活率、肥满度、肝体比及脏体比组间无显著性差异(P>0.05)。(3)暂养30d和40d组血清中的白蛋白和总蛋白含量显著高于对照组和暂养20d组(P<0.05),但其γ-谷氨酰基转移酶和碱性磷酸酶活性、总胆固醇和总胆汁酸含量显著低于对照组和暂养20d组(P<0.05);对照组、暂养2...     

重复经颅磁刺激对创伤性颅脑损伤患者脑脊液中兴奋性氨基酸含量的影响

目的：探讨重复经颅磁刺激（rTMS）对急性颅脑损伤患者脑脊液中兴奋性氨基酸（EAA）含量的影响。方法：30例创伤性颅脑损伤（TBI）病人按格拉斯哥昏迷评分分为轻型组（rTMS3）、中型组（rTMS2）、重型组（rTMS1）,每组10例,各组病人分别随机分为rTMS对照亚组（A组）及治疗亚组（B组）,每亚组5例。于TBI后第15天行腰椎穿刺采集脑脊液,采用高效液相色谱法测定脑脊液中谷氨酸（ASP）及门冬氨酸（GLU）含量。结果：脑脊液ASP和GLU水平随着脑损伤程度的加重而升高,各rTMS治疗组与相应各对照组的EAA相比,rTMS治疗组EAA的水平均低于相应对照组。结论：rTMS可通过降低TBI后脑脊液EAA水平发挥脑保护作用。脑脊液EAA的含量变化可作为TBI严重程度的生化指标。     

Evaluation of natural resistance of winter triticale cultivars to grain aphid using food coefficients

Five food coefficients were used to evaluate resistance of winter triticale cultivars against grain aphid Sitobion avenae (Fabr.). On the basis of the results of biochemical analysis the following coefficients were calculated: soluble carbohydrates–total nitrogen, soluble carbohydrates–free amino acids, soluble carbohydrates–protein amino acids, nonprotein amino acids–protein amino acids, nonprotein amino acids–free protein amino acids. The results showed that the values of all coefficients for the 'Lasko' cultivar, which is resistant to S. avenae , were higher than those of the susceptible 'Grado' cultivar. Applied tests of natural resistance of winter triticale, based on biochemical properties of the plants, revealed considerable variability of resistance of both cultivars to grain aphid. Thus, the tests may be very useful for preliminary selection of newly introduced strains and cultivars of winter triticale in respect of their resistance to grain aphid. The method may be also applied for a quick evaluation of new genetically engineered products and the culture of highly aphid-resistant plants.     

Amino acid supplementation alters bone metabolism during simulated weightlessness.

High-protein and acidogenic diets induce hypercalciuria. Foods or supplements with excess sulfur-containing amino acids increase endogenous sulfuric acid production and therefore have the potential to increase calcium excretion and alter bone metabolism. In this study, effects of an amino acid/carbohydrate supplement on bone resorption were examined during bed rest. Thirteen subjects were divided at random into two groups: a control group (Con, n = 6) and an amino acid-supplemented group (AA, n = 7) who consumed an extra 49.5 g essential amino acids and 90 g carbohydrate per day for 28 days. Urine was collected for n-telopeptide (NTX), deoxypyridinoline (DPD), calcium, and pH determinations. Bone mineral content was determined and potential renal acid load was calculated. Bone-specific alkaline phosphatase was measured in serum samples collected on day 1 (immediately before bed rest) and on day 28. Potential renal acid load was higher in the AA group than in the Con group during bed rest (P < 0.05). For all subjects, during bed rest urinary NTX and DPD concentrations were greater than pre-bed rest levels (P < 0.05). Urinary NTX and DPD tended to be higher in the AA group (P = 0.073 and P = 0.056, respectively). During bed rest, urinary calcium was greater than baseline levels (P < 0.05) in the AA group but not the Con group. Total bone mineral content was lower after bed rest than before bed rest in the AA group but not the Con group (P < 0.05). During bed rest, urinary pH decreased (P < 0.05), and it was lower in the AA group than the Con group. These data suggest that bone resorption increased, without changes in bone formation, in the AA group.     

山药对环江香猪营养物质消化代谢的影响

为了探讨山药对环江香猪营养物质消化代谢的影响,本研究选用体重为4.55±0.63 kg的环江香猪10头,随机分为2组,每组5头,单笼饲养,分别饲喂山药日粮和基础日粮,试验期为7 d。试验开始和结束时分别称取试验猪体重,记录日采食量;试验第5～7 d收集粪样,用TiO2指示剂法测定常规营养成分的消化率;试验第7 d采血分离血浆,分别用全自动生化分析仪和氨基酸分析仪测定生化指标和氨基酸浓度。结果表明,与对照组相比,试验组平均日增重、粗蛋白、粗脂肪和干物质消化率均有所提高(P>0.05);血浆尿素氮和血氨浓度均显著降低、总蛋白浓度显著升高(P<0.05),白蛋白和葡萄糖浓度及碱性磷酸酶活性均有所升高(P>0.05);血浆丙氨酸、甘氨酸、天冬氨酸、谷氨酸、苏氨酸和总氨基酸浓度均显著升高(P<0.05)。上述结果提示,山药可改善环江香猪的消化代谢功能,这为开发环江香猪的绿色环保饲料提供了一定的科学依据。     

激光和γ射线复合处理对水稻胚芽中17种氨基酸含量的影响

用２８、５６ｒｄγ射线单一和加５、１５、２５ｍｉｎＮ＿２激光处理水稻干糙米,经发芽后,测定各处理胚芽中１７种氨基酸的含量,结果表明：两种剂量的γ射线单一处理均能使所测１７种氨基酸中的多数,其含量降低。而加适当剂量的Ｎ＿２激光辐照,可使多数氨基酸的含量得到回升,甚至超过对照。这些研究结果表明：一定剂量的激光对于因γ射线辐射引起的氨基酸含量降低的异常生化现象,具有修复作用。     

Cultural characteristics and fatty acid composition of propionibacteria

The cultural characteristics and cellular fatty acid composition of 40 strains representing 7 species of Propionibacterium and of 9 cultures of anaerobic corynebacteria were studied. The cultures were characterized by means of 23 separate cultural and biochemical tests. Cultures of the two genera differed consistently in only two reactions; the propionibacteria did not produce indole or liquefy gelatin, whereas the anaerobic corynebacteria were consistently positive with these tests. The fatty acids were extracted from whole cells and examined as methyl esters by gas-liquid chromatography. The most abundant acid in the seven Propionibacterium species was a C(15)-saturated branched-chain acid which was present in both the iso-and anteiso-form. Based on a comparison of the relative abundance of these isomers (i-C(15) and a-C(15)), the species were separated into two groups. P. freudenreichii and P. shermanii (group one) were similar and contained the a-C(15) isomer as the predominant acid. The i-C(15) isomer was the most abundant acid in the second group (P. arabinosum, P. jensenii, P. pentosaceum, P. thoenii, and P. zeae). The fatty acid profiles of the anaerobic corynebacteria were somewhat similar to those of the second group of propionibacteria, but were distinct from the profiles of P. freudenreichii and P. shermanii. The addition of branched-chain amino acids (l-leucine and l-isoleucine) to the growth medium increased the synthesis of the specific fatty acid(s) structurally related to the added amino acid.     

双氯醇胺对湖羊后肢肌肉氨基酸净平衡的调节

采用４头装有长久性肠系膜静脉和右后肢股动、静脉血管瘘的湖羊,按自身对照设计,研究了β－激动剂双氯醇胺以湖羊后肢肌肉氨基酸净平衡的调节。经肠系膜静脉灌注双氯醇胺,湖羊后肢血液氨基酸流量与对照其相比有有显著差异（Ｐ〈０．０１）。在１５种氨基酸中,有１０种氨基酸的吸收量大幅度增加;另有５种氨基酸释放量增加,或者吸收量减小。结果表明,有氯醇胺可通过改变肌肉吸收或释放氨基酸的种类和数量来调节湖羊后肢肌肉氨基     

THE FREE AMINO ACIDS IN HUMAN CEREBROSPINAL FLUID

—(a) The free amino acids in human cerebrospinal fluid from 78 subjects have been determined by means of ion exchange chromatography. Analyses were performed on 2 to 3 ml of CSF. (b) Normal values are given for a control group of 13 subjects. (c) The presence of homocarnosine in human CSF is ascertained. The concentration of this dipeptide is very high in CSF samples from phenylketonuric patients. (d) The CSF amino acid pattern in 20 patients with a metabolic disease is discussed. (e) The CSF amino acid pattern of 38 patients suffering from a variety of neurological conditions are reported.     

Concentrations of GABA and Other Amino Acids in CSF from Torsion Dystonia Patients

Abstract: Free amino acid concentrations were measured by conventional amino acid analysis, and γ-aminobutyric acid (GABA) concentrations were determined, by an ion-exchange fluorometric technique, in CSF specimens from 16 patients with torsion dystonias and in CSF from a large number of control subjects. The mean CSF GABA concentration of the dystonia patients (97 ± 11 nmol/L) did not differ significantly from the means for CSF GABA in two groups of adult control subjects. Mean concentrations of all commonly determined amino compounds were normal in the CSF of torsion dystonia patients, except for ornithine, which was modestly but significantly reduced.