香菇多糖的免疫调节作用

研究香菇多糖(LTN)的免疫调节作用。结果表明,LTN1及5mg·kg^-1·d^-1×6,ip可促进正常小鼠由ConA(2.5mg·kg^-1)刺激的脾脏T淋巴细胞增殖反应。1,5及10mg·kg^-1·d^-1×8或5,ip能分别纠正由环磷酰胺(Cy,200mg·kg^-1和80mg·kg^-1,ip)诱导的免疫亢进或低下状态。此外,LTN(1,5和10mg·kg^-1·d^-1×6,ip),促使小鼠胸腺L3T4+(Th)和Lyt2+(Ts)细胞数减少,外周脾脏L3T4+和Lyt2+细胞数增加,腹腔巨噬细胞释出肿瘤坏死因子(TNF)也明显增加。这些作用均以LTN5mg·kg^-1·d^-1作用最佳。提示LTN可能通过影响T细胞及其亚型,促进TNF活性调节机体的免疫功能。     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: PHYSIOLOGICAL ACTIONS OF ANGIOTENSIN II MEDIATED BY AT1 AND AT2 RECEPTORS IN THE BRAIN

• 1 Autoradiographic binding studies have shown that the AT₁ receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT₁ receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
• 2 While there are differences between species, AT₂ receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
• 3 Circulating AngII acts on AT₁ receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
• 4 Centrally administered AngII may act on AT₁ receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
• 5 Recent evidence shows that centrally administered AT₁ antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
• 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT₁ receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.

     

常咯啉在实验性心律失常狗的药代动力学－药效动力学分析

用Ｈａｒｒｉｓ冠脉结扎法诱发的心律失常狗研究常咯啉药代动力学－药效动力学。７只狗按８３．３３μｇ·ｋｇ￣（－１）·ｍｉｎ￣（－１）静脉滴注６０ｍｉｎ，在给药期间和停药后不同时间记录ＥＣＧ及测定血药浓度。Ｃ－Ｔ数据用药代程序计算药代参数；药效数据用药代－药效同步分析模型计算药效动力学参数，Ｋ１０，Ｔ１／２，Ｖｄ，Ｃｌ分别为０．００８７ｍｉｎ￣（－１），７８．０３ｍｉｎ，４０．５５ｍｌ·ｋｇ￣（－１）和０．４２１ｍｌ·ｋｇ￣（－１）·ｍｉｎ￣（－１）；Ｋｅ０和Ｃｅ（５０）分别为０．００４８ｍｉｎ￣（－１）和２．０１μｇ·ｍｌ￣（－１）.     

常咯啉在实验性心律失常狗的药代动力学-药效动力学分析

用Harris冠脉结扎法诱发的心律失常狗研究常咯啉药代动力学-药效动力学。7只狗按83.33μg·kg^-1·min^-1静脉滴注60min,在给药期间和停药后不同时间记录ECG及测定血药浓度。C-T数据用药代程序计算药代参数;药效数据用药代-药效同步分析模型计算药效动力学参数,K₁₀, T_1/2,Vd,Cl分别为0.0087min^-1,78.03min,40.55ml·kg^-1和0.421ml·kg^-1·min^-1;K_eO和Ce(50)分别为0.0048min^-1和2.01μg·ml^-1.     

ANTEROVENTRAL WALL OF THE THIRD VENTRICLE AND DORSAL LAMINA TERMINALIS: HEADQUARTERS FOR CONTROL OF BODY FLUID HOMEOSTASIS?

1. The subfornical organ, median preoptic nucleus and the organum vasculosum of the lamina terminalis (OVLT) are a series of structures situated in the anterior wall of the third ventricle and form the lamina terminalis. The OVLT and ventral part of the median preoptic nucleus are part of a region known as the anteroventral third ventricle region.
2. Data from many laboratories, using techniques ranging from lesions, electrophysiology, neuropharmacology, Fos expression, immunohistochemistry and receptor localization, indicate that the tissue in the lamina terminalis plays a major role in many aspects of body fluid and electrolyte balance.
3. The subfornical organ and OVLT lack the blood-brain barrier and detect alterations in plasma tonicity and the concentrations of circulating hormones such as angiotensin II and possibly atrial natriuretic peptide and relaxin.
4. This information is then integrated within the lamina terminalis (probably in the median preoptic nucleus) with neural signals from other brain regions. The neural output from the lamina terminalis is distributed to a number of effector sites including the paraventricular (both parvo- and magno-cellular parts) and supraoptic nuclei and influences vasopressin secretion, water drinking, salt intake, renin secretion, renal sodium excretion and cardiovascular regulation.     

Choice feeding of selenium-deficient laying hens affects diet selection,selenium intake and body weight

Inadequate selenium (Se) supply often in combination with low vitamin E status causes deficiency symptoms in many species. It is likely that a vague discomfort or sickness is perceived before clear deficiency signs become apparent. We investigated whether Se-deficient hens reduce their Se deficit by selecting a diet containing more selenium when offered two diets with different Se concentrations. A Low-Se diet (0.07 mg Se/kg) was supplemented with Se-enriched yeast (Sel-Plex 50) to produce Medium-Se (0.20 mg Se/kg) and High-Se (1.50 mg Se/kg) diets. Each of two consecutive study parts (I and II) with the same hens and treatments began with a 6-wk baseline period (Medium-Se diet), subsequently followed a 9-wk depletion period (Low-Se diet or Medium-Se diet), then a 6-wk choice feeding period in which two diets with different Se concentrations (Low-Se and Medium-Se, Medium-Se and High-Se, or Low-Se and High-Se) were offered. A control group received the Medium-Se diet throughout the study. Daily Se intake, calculated from daily feed intake, followed similar patterns in both parts of the study, but Se-deficient hens preferred (P < 0.05) the High-Se diet to the Low-Se diet during the first 3 wk of choice feeding only in part I. We conclude that young Se-deficient laying hens reduce their Se deficit if they have a choice between a Low-Se and a High-Se diet by preferentially selecting the High-Se diet, possibly based on learned place preference and/or learned taste aversion to the Low-Se diet, presumably in response to discomfort due to Se-deficiency.     

氟化钠、单氟磷酸钠漱口后2 h菌斑液、菌斑及唾液氟离子的测定

氟化钠(NaF)和单氟磷酸钠(NaMFP)是目前市售最常见的含氟牙粉。以前一致认为氟的抗龋效能取决于牙所处液体环境中Fˉ浓度,但其临床抗龋效果却与二者的Fˉ浓度出现较大差异。本研究定量分析NaF和NaMFP液漱口后,唾液、全菌斑及菌斑液中Fˉ、MFPˉ浓度的变化,揭示其不同的抗龋特性。 标本取自12位自愿受试者。每个象限各选一颗磨牙或前磨牙取菌斑。测前48h不刷牙,当晚禁食,次日上午收集龈下菌斑和唾液标本作为基线水     

Inflammation and aging: Can endocannabinoids help?

Aging often leads to cognitive decline due to neurodegenerative process in the brain. As people live longer, there exists a growing concern linked to long-term, slowly debilitating diseases, such as Alzheimer's disease for which a cure has not yet been found. Recently, the role of neuroinflammation has attracted attention due to its slow onset, chronic nature and its possible role in the development of many different neurodegenerative diseases. In the future, treatment of chronic neuroinflammation may help counteract aspects of neurodegenerative disease. Our recent studies have focused upon the endocannabinoid system for its unique effects on the expression of neuroinflammation. The basis for the manipulation of the endocannabinoid system in the brain in combination with existing treatments for Alzheimer's disease will be discussed in this review.