Plasmapheresis in the treatment of hepatic coma]

Fourteen patients, including 6 with viral hepatitis B and 8 with liver cirrhosis were treated with plasmapheresis for hepatic coma. Altogether 29 plasmaphereses were carried out. Complete recovery was achieved in one patient with viral hepatitis B and in 3 patients with liver cirrhosis. Plasmapheresis should be performed in patients with severe lesions to the liver. Classification of patients to the treatment should include clinical examination, biochemical and enzymatic tests, and evaluation of liver reserve with isotope hepatography. In case of the acute poisoning with hepatotoxic agents indications to plasmapheresis should be evaluated from the toxicologic point of view.     

Enzyme preparations for research on protein hydrolysates and amino acid mixtures not containing peptides

Some properties and the hydrolysing ability of two novel enzyme preparations, a proteolytic preparation "C" from Acremonium chrysogenum (Cephalosporium acremonium) and a peptidase preparation (the producer from the family Pseudomanadaceae), are described. The preparations can be used for obtaining protein hydrolysates with different ratios of free amino acids and peptides. The protein hydrolysis with the preparation "C" enables one to obtain hydrolysates containing 13-18% of free amino acids. The further treatment of the hydrolysates with the peptidase preparation results either in complete hydrolysis of the remained peptide fractions or in obtainment of solutions containing from 60 to 85% of free amino acids and low-molecular weight peptides.     

微生态制剂治疗轻微肝性脑病的有效性及安全性分析

评价微生态制剂治疗轻度肝性脑病(MHE)的有效性及安全性。

检索自建库至2020年9月在中国知网、万方数据知识服务平台、维普、中国生物医学文献服务系统、PubMed、Web of Science、Embase、Cochrane Library等数据库收录的关于微生态制剂治疗MHE的临床随机对照试验。

共纳入21篇文献, 包括1 543例患者。结果显示, 2组研究对象比较, 微生态制剂能提高双歧杆菌、乳杆菌水平, 差异有统计学意义[MD=1.82, 95%CI(1.19, 2.44), Z=5.70, P < 0.000 1;MD=1.74, 95%CI(0.95, 2.54), Z=4.30, P < 0.000 1], 降低肠杆菌水平[MD=-1.27, 95%CI(-1.97, -0.57), Z=3.55, P=0.000 4], 而肠球菌水平差异无统计学意义(P > 0.050 0);2组研究对象比较, 微生态制剂可显著降低血氨水平、ET水平[SMD=-0.83, 95%CI(-1.08, -0.58), Z=6.43, P < 0.000 1;MD=-0.08, 95%CI(-0.14, -0.01), Z=2.35, P=0.020 0];2组研究对象比较, 微生态制剂可显著降低数字连接试验A(NCT-A)用时[MD=-16.46, 95%CI(-21.33, -11.59), Z=6.63, P < 0.000 1], 而数字符号试验(DST)差异无统计学意义(P > 0.050 0);2组研究对象比较, 微生态制剂可降低终末期肝病模型评分(MELD)、Child-Pugh评分、OHE发生率[MD=-2.41, 95%CI(-3.87, -0.95), Z=3.24, P=0.001 0;MD=-1.54, 95%CI(-1.92, -1.16), Z=7.95, P < 0.000 1; OR=0.32, 95%CI(0.20, 0.52), Z=4.66, P < 0.000 1], 并显著提高临床有效率[OR=4.95, 95%CI(2.48, 9.86), Z=4.55, P < 0.000 1], 但不会增加不良反应[OR=0.48, 95%CI(0.12, 1.91), Z=1.04, P=0.300 0]。

微生态制剂可基于调节肠道菌群平衡有效改善MHE, 可防止OHE的发生, 且安全性好, 有望成为治疗MHE的最新选择。

     

Plasmapheresis in the treatment of hepatic coma complicating viral hepatitis]

Therapeutic plasmaphereses using CS 3000 Fenwal Cell Separator were performed in 4 women and 2 men, aged between 17 and 44 years, with hepatic coma complicating acute viral hepatitis type B. One to four plasma exchanges per patient were performed, usually at the volume of 3000 ml per procedure. Two patients at II and IVa period of the coma, according to Aboun classification, survived. Four patients at II, III and two at III/IV period of the coma died. The authors suggest that in some cases exchange of large volumes of plasma in the treatment of hepatic coma complicating acute viral hepatitis may be a lifesaving procedure.     

Elimination of phenylalanine from amino acid mixtures obtained from yeast hydrolysates and autolyzates]

In order to obtain amino acid mixtures devoid of phenylalanine, adsorption of aromatic amino acids was studied during their chromatography on ion-exchange resin IA-Ip. When 40 g of the amino acid mixture were passed through 400 ml of the swollen ion-exchange resin, phenylalanine and tyrosine were eliminated and 67% of dry substance were yielded. Ion-exchange resin adsorbed phenylalanine and tyrosine could be regenerated. The use IA-Ip is advantageous as compared with that of ion-exchange resin Amberlite IR-45 and activated charcoal.     

Electrochromatography of amino acid mixtures in fermentation liquors

The substitution of the phenolic chromatography dimension, by electrophoresis at 500 to 1000 volts, in a veronal buffer, pH 8.6, μ 0.02 followed by triple rechromatography in a completely miscible butanol, acetic acid, water solvent system, leads to clear, easily reproducible electrochromatography patterns. A reliable economical chromatography cabinet is described. The technique allows the analysis of many samples conveniently, and some important characteristics of unidentifiable components can be readily predicted.     

Extra- and intracellular amino acids in the hippocampus during development of hepatic encephalopathy

Fulminant hepatic failure was induced in rabbits by intravenous administration of galactosamine hydrochloride. The animals were sacrified after 45 h and the hippocampus analyzed for free amino acids. In addition, free amino acids were measured in plasma and in the extracellular fluid of the hippocampus 20, 30 and 45 h after galactosamine injection. The extracellular fluid compartment was analyzed by slow perfusion of a thin dialysis tube which was implanted in the hippocampus one day prior to galactosamine administration. The amino acid concentration in the extracellular fluid agreed fairly well with that of the cerebrospinal fluid in the control situation. During development of hepatic failure, the plasma concentrations of all amino acids increased. The changes in extracellular amino acids were smaller, except for phosphoethanolamine and glutamate. The concentration ratio intra/extracellular amino acids decreased in the hippocampus for amino acids with a normally high concentration gradient.     

Influence of triiodothyronine and dexamethasone on renal amino acid handling in rats loaded with various amino acid mixtures

Summary In adult female rats, the influence of dexamethasone or triiodothyronine on renal amino acid handling was investigated in amino acid loaded animals. Amino acids were administered intravenously as two mixtures, each containing four amino acids to overload amino acid reabsorption capacity. Bolus injections of both mixtures were followed by temporary increase in fractional excretion of the administered amino acids as well of the amino acids which were not covered in the mixtures. The administration of the two mixtures was followed by different interactions between various amino acid carriers.After dexamethasone pretreatment (60µg/100g b.wt. for 3 days, once daily) a stimulation of the renal amino acid handling could be shown. Triiodothyronine (20µg/100g b.wt. for 3 days, once daily) did not increase tubular reabsorption capacity for amino acids. It even increased fractional amino acid excretion in amino acid loaded rats as a sign of enhanced amino acid metabolism in the kidney and/or increased amino acid uptake into the tubular cells from the luminal site.     

Hormonal regulation of hepatic amino acid transport

The transport of 2-aminoisobutyric acid (AIB) into liver tissue was increased by both insulin and glucagon. We have now shown that these hormones do not stimulate the same transport system. Glucagon, possibly via cAMP, increased the hepatic uptake of AIB by a mechanism which resembled system A. This glucagon-sensitive system could be monitored by the use of the model amino acid MeAIB. In contrast, the insulin-stimulated system exhibited little or no affinity for MeAIB and will be referred to as system B. On the basis of other reports that the hepatic transport of AIB is almost entirely Na⁺ dependent and the present finding that the uptake of 2-aminobicyclo [2,2,1] heptane-2-carboxylic acid (BCH) was not stimulated by either hormone, we conclude that system B is Na⁺ dependent. Furthermore, insulin added to the perfusate of livers from glucagon-pretreated donors suppressed the increase in AIB or MeAIB uptake. Depending upon the specificities of systems A and B, both of which are unknown for liver tissue, the insulin/glucagon ratio may alter the composition of the intracellular pool of amino acids.     

Antiradiation effectiveness of amino acid mixtures of various compositions

Radioprotective efficacy of differently composed amino acid mixtures (e. g. swine brain hydrolyzate, mixtures of several crystalline amino acids, etc.) was estimated. The survival rate and average life of exposed animals increased after the administration of amino acid preparations. The most pronounced effect was produced by the mixtures composed of several crystalline amino acids.     

Experimental study of the effectiveness of antibacterial preparations in treating dysentery]

It was found that for successful elaboration of effective schemes for the use of antibacterial drugs in treatment of dysentery it was necessary to exploit various experimental models providing consideration of the drug toxicity and effect on the extra- and intracellular growth of the bacteria in addition to the other factors. The administration of enteroceptol for 3 days followed by furazolidon showed the best therapeutic effect in the treatment of guinea pigs with Shigella keratoconjunctivitis and Syrian hamsters with dysentery. The above drugs had low toxicity which was shown in the experiments with Hep-2 cell cultures. It was concluded that the use of the drugs with different modes of action was advisable in treatment of dysentery.     

Phase separation in amino acid mixtures is governed by composition

Macromolecular phase separation has recently come to immense prominence as it is central to the formation of membraneless organelles, leading to a new paradigm of cellular organization. This type of phase transition, often termed liquid-liquid phase separation (LLPS), is mediated by molecular interactions between biomolecules, including nucleic acids and both ordered and disordered proteins. In the latter case, the separation between protein-dense and -dilute phases is often interpreted using models adapted from polymer theory. Specifically, the “stickers and spacers” model proposes that the formation of condensate-spanning networks in protein solutions originates from the interplay between two classes of residues and that the main determinants for phase separation are multivalency and sequence patterning. The duality of roles of stickers (aromatics like Phe and Tyr) and spacers (Gly and polar residues) may apply more broadly in protein-like mixtures, and the presence of these two types of components alone may suffice for LLPS to take place. In order to explore this hypothesis, we use atomistic molecular dynamics simulations of capped amino acid residues as a minimal model system. We study the behavior of pure amino acids in water for three types of residues corresponding to the spacer and sticker categories and of their multicomponent mixtures. In agreement with previous observations, we find that the spacer-type amino acids fail to phase separate on their own, while the sticker is prone to aggregation. However, ternary amino acid mixtures involving both types of amino acids phase separate into two phases that retain intermediate degrees of compaction and greater fluidity than sticker-only condensates. Our results suggest that LLPS is an emergent property of amino acid mixtures determined by composition.     

Decrease in plasma tryptophan after tryptophan-free amino acid mixtures in man

Male healthy subjects, fasting 12 hours, ingested increasing amounts of a mixture containing a fixed proportion of seven essential amino acids (L-isoleucine 11.5%, L-leucine 18.0%, L-lysine 13.1%, L-methionine 18.0%, L-phenylalanine 18.0%, L-threonine 8.2%, L-valine 13.1%) and lacking tryptophan. The diets produced a rapid fall in plasma tryptophan which was proportional to the total amount of the amino acids ingested. Following the highest dose administered (36.6 g) plasma tryptophan fell to a minimum of about 35% the initial level and remained markedly reduced at 6 hours after treatment. The mechanism of this decrease and its potential clinical relevance are discussed.