中药活性成分通过调控肠道菌群改善2型糖尿病的作用研究进展

2型糖尿病(type 2 diabetes mellitus, T2DM)是慢性代谢疾病之一,因高患病率成为当今全球性公共健康难题。肠道菌群在T2DM的发生和发展中发挥重要作用,通过调节肠道菌群治疗T2DM已经成为当前研究的焦点。近年来,已有研究表明中药在改善T2DM的同时使肠道菌群发生变化,但中药是否通过调控肠道菌群发挥药理作用尚不明确。中药富含的多种活性成分是中药发挥药理作用的关键。因此,本文系统总结了中药多糖类、生物碱类、黄酮类、皂苷类及其他类活性成分调节肠道菌群干预T2DM的研究进展,旨在为中药预防和治疗T2DM作用提供更充分的理论依据,这对加速中药现代化具有重要意义。     

土壤增温与氮添加对杉木幼苗细根径级根长分布的影响

通过在福建省三明市陈大林业国有林场内开展土壤增温(增温5 ℃、不增温)和氮添加(不添加、4、8 g N·m^-2·a^-1)的交互试验(共6个处理),研究土壤增温、氮添加及二者交互作用对杉木细根径级根长分布的影响,用扩展模型可很好地拟合6个处理的径级根长分布(R²=0.97).结果表明: 增温使杉木细根总根长变小,但对细根直径影响不显著;氮添加使杉木细根总根长和直径均变小;增温和氮添加的交互作用对细根总根长有显著影响,但对细根直径无显著影响.6个处理细根径级根长分布均能用极值函数模型较好地拟合(R²>0.98).相关分析显示,直径<1 mm细根的比根长与极值模型拟合参数c值呈显著负相关,实际总根长与极值模型拟合参数b呈显著正相关.增温和氮添加及其交互作用可以影响杉木细根形态特征;极值模型拟合各处理径级根长分布所得参数在一定程度上可以反映细根形态特征对环境条件变化的响应.     

Influence of semax on the emotional state of white rats in the norm and against the background of cholecystokinin-tetrapeptide action

The effects of the adrenocorticotropic hormone (ACTH(4–10)) analog, Semax (MEHFPGP), on the level of anxiety and depression in white rats have been studied in the normal state and against the back-ground of cholecystokinin-tetrapeptide (CCK-4) action. Semax was injected intranasally in doses of 50 and 500 μg/kg 15 min before the testing. CCK-4 was administered intraperitoneally in a dose of 400 μg/kg 40 min before the testing. The level of anxiety was estimated in the elevated plus-maze test, and the degree of depression, in the forced swimming test. Semax administration did not influence the emotional state of animals in the normal state. The CCK-4 injection led to an increase in anxiety and depression in rats. Semax normalized the animal behavior disturbed by the CCK-4 administration, which attests to its anxiolytic and antidepressant effects at elevated levels of anxiety and depression.     

Antibodies to synthetic peptides for the detection of survivin in tumor tissues

Survivin, an endogenous protein, is a promising marker for the cancer diagnosis. The aim of the present work was to obtain antibodies specific to survivin and capable of detecting this protein in tumor tissues. Four peptides corresponding to fragments (1–22), (54–74), (80–88)–(153–165), and (118–144) of the survivin-2B sequence were selected and synthesized. Rabbits were immunized with the synthetic peptides. It has been shown that all peptides in a free state, without conjugation with a high-molecular-weight carrier, stimulate the production of antibodies capable of binding with recombinant survivin. Antipeptide antibodies were isolated from sera and their performance in the immunohistochemical detection of survivin in human tumor tissues was studied. It was shown that only antibodies to the (80–88)–(153–165) peptide bind to the survivin present in breast and bladder tumors. The ability of antibodies to this peptide to detect survivin in tumor tissue lysates was demonstrated by immunoblotting. The part of the sequence targeted by the antibodies against the (80–88)–(153–165) peptide was localized using truncated peptide fragments.     

Interaction of human mesenhymal stromal with immune cells

Multipotential mesenchymal stromal cells (MMSCs) are the subject of increasing scientific interest due to the key role of these cells in physiological renewal and repair. Allogeneic MMSC interaction with other components of tissue processes in the environment, in particular, with immune cells is one of the most intriguing questions of modern cell physiology. MMSCs possess pronounced immunomodulatory capabilities based on their immmunoprivilege properties and the ability to suppress an immune response. This review considers the state-of-the-art in the field of MMSC immunomodulatory effects and their mechanisms. The interaction between MMSCs and immune cells is a complex, multidirectional process governed by both direct cell-to-cell interactions and soluble factors (interferon-γ, tumor necrosis factor, prostaglandin E₂, hepatocyte growth factor, interleukins, etc.). The importance of physical environmental factors, primarily oxygen tension, for the characteristics of the interaction between MMSCs and immune cells is discussed.     

The effect of internal exposure to 90Sr on hematopoietic stem cells in CBA mice

After acute intake of 90Sr the changes of d-9 CFUs number in mice (CBA) bone marrow, spleen and peripheral blood were investigated. The obtained results indicated similar quantitative changes in bone marrow and spleen CFUs on exposure to the 90Sr when radiation doses did not cause the decrease in life-time (1.11 kBq/g). Sarcomogeneous doses of 90Sr (29.6 kBq/g) resulted in drastic changes of hemopoietic system: spleen haematopoiesis activation and suppression of bone marrow functions. On the first day after 90Sr injection (29.6 kBq/g) the increase in number of peripheral blood CFUs (circulating pool) was observed.     

Epileptogenic activity of tripeptide corticotropin-releasing factor fragment (CRF(4-6))

The effects of centrally administered tripeptide fragment CRF(4-6) of corticotropin-releasing factor on convulsive activity in outbred albino rats were investigated. The peptide CRF(4-6) (icv; 6, 30, 150 nmol/head) causes dose-dependent increase in total EEG power in 1-40 Hz frequency range as a reflection of tripeptide-induced various epileptiform EEG signs such as single peaks and spike trains without external convulsion. Higher doses of CRF(4-6) (icv; 150, 225, 300 nmol per animal) induce tonicoclonic seizures. Switching to convulsive activity occurs at CRF(4-6) dose of 150 nmol per animal: injection of this dose leads only to EEG paroxysmal activity under habitual conditions and induces pathological locomotor activation under stressing conditions. Thus, CRF(4-6) similarly to full-length corticotropin-releasing factor induces epileptiform activity in rats.