早产儿瘦素质量浓度与早期静脉营养及生长发育相关性探讨

目的探讨瘦素质量浓度与早期静脉营养及生长发育的关系。方法新疆医科大学第一 附属医院新生儿科于2005 01—2006 02，将收治的86例早产适于胎龄儿用随机数字表法分为观察组(早期微量喂养同时辅助胃肠外营养组)45 例和对照组(单纯早期微量喂养组)47例，分别测定脐血及第7天血清瘦素质量浓度，同时监测营养状况和生长发育指标，并作对比分析。结果 (1)观察组与对照组脐血瘦素质量浓度分别为(4.6±3.7)ng/mL、(4.8±2.2)ng/mL，生后第7天两组瘦素质量浓度分别为(4.3±2.2)ng/mL、(3.1 ±1.7)ng/mL。对照组第7天血清瘦素质量浓度明显低于脐血(P<0.05)，而观察组其差异无统计学意义(P>0.05)。(2)脐血瘦素质量浓度与出生体 重、胎龄成正相关(r=0.56、r=0.67)。(3)观察组第7天热卡及蛋白质摄入量、血清瘦素质量浓度、皮褶厚度变化值与对照组相比，差异有统计 学意义(P<0.05)。结论对早产儿应尽早喂养，同时需要胃肠外营养作为肠内营养的补充。瘦素可作为新生儿营养效果判定的实验室指标之一。     

Temporal Dynamics of the Intestinal Microbiome Following Short-Term Dietary Restriction

Short-term dietary restriction has been proposed as an intriguing pre-operative conditioning strategy designed to attenuate the surgical stress response and improve outcomes. However, it is unclear how this nutritional intervention influences the microbiome, which is known to modulate the systemic condition. Healthy individuals were recruited to participate in a four-day, 70% protein-restricted, 30% calorie-restricted diet, and stool samples were collected at baseline, after the restricted diet, and after resuming normal food intake. Taxonomy and functional pathway analysis was performed via shotgun metagenomic sequencing, prevalence filtering, and differential abundance analysis. High prevalence species were altered by the dietary intervention but quickly returned to baseline after restarting a regular diet. Composition and functional changes after the restricted diet included the decreased relative abundance of commensal bacteria and a catabolic phenotype. Notable species changes included Faecalibacterium prausnitzii and Roseburia intestinalis, which are major butyrate producers within the colon and are characteristically decreased in many disease states. The macronutrient components of the diet might have influenced these changes. We conclude that short-term dietary restriction modulates the ecology of the gut microbiome, with this modulation being characterized by a relative dysbiosis.     

针刺足三里对对乙酰氨基酚诱发大鼠肝损伤的影响

目的：观察针刺足三里对对乙酰氨基酚（ APAP）多次给药诱发大鼠肝损伤血清转氨酶和肝脏病理学变化的影响,探讨针刺对药源性肝脏损伤的保护作用。方法75只SD大鼠随机分为正常对照组（ NC组）、APAP模型1组（ APAP1组）、针刺＋APAP 模型1组（ ZC＋APAP1组）、 APAP模型2组（ APAP2组）、针刺＋APAP模型2组（ ZC＋APAP2组）。 APAP1组和APAP2组大鼠每天分别按体重灌胃给予APAP 300、600 mg／kg;APAP1组和APAP2组大鼠每天分别按体重灌胃给予 APAP 300、600 mg／kg后即刻针刺其后肢足三里穴20 min;NC组灌胃给予相同体积剂量的生理盐水。各组大鼠连续给药或针刺14 d后,检测血清转氨酶活性和检查肝脏病理学变化情况。结果与NC组相比,ZC＋APAP1组、APAP2组和ZC＋APAP2组大鼠血清AST和ALT活性均显著升高（P＜0．05或P＜0．01）;与APAP1组、APAP2组相比, ZC＋APAP1组、ZC＋APAP2组大鼠血清AST、ALT活性均显著性升高（P＜0．05或P＜0．01）。 APAP1组和ZC＋APAP1组间肝脏病理学改变,差异无统计学意义（P＞0．05）,而APAP2组与ZC＋APAP2组肝脏病理学改变显著（P＜0．05）。结论针刺足三里促进APAP诱导大鼠血清AST和ALT活性的升高;但肝脏病理组织学检查结果显示,针刺足三里对APAP多次给药诱发大鼠肝损伤具有一定的保护作用。     

Expression of fibrinogen receptors during activation and subsequent desensitization of human platelets by epinephrine

Epinephrine causes platelet aggregation and secretion by interacting with alpha 2-adrenergic receptors on the platelet surface. Platelet aggregation requires the binding of fibrinogen to a specific receptor on the membrane glycoprotein IIb-IIIa complex. Although the IIb-IIIa complex is identifiable on the surface of resting platelets, the fibrinogen receptor is expressed only after platelet activation. The current studies were designed to examine the effect of occupancy of platelet alpha 2-adrenergic receptors by epinephrine on the expression of fibrinogen receptors and on the aggregation of platelets. The ability of epinephrine to induce the expression of fibrinogen receptors was studied under two different conditions: acute stimulation (less than 1 min) and prolonged stimulation (50 to 90 min), the latter of which is associated with a reduction or "desensitization" of the platelet aggregation response. Expression of the fibrinogen receptor was monitored with 125I-fibrinogen as well as with 125I-PAC-1 (PAC-1), a monoclonal antibody that binds to the glycoprotein IIb-IIIa complex only after platelets are activated. Epinephrine caused an immediate increase in PAC-1 and fibrinogen binding that was dependent on occupancy of the alpha 2-receptor by epinephrine and on the presence of extracellular free Ca (KCa = 30 mumol/L). By itself, 1 mmol/L Mg was unable to support induction of the fibrinogen receptor by epinephrine. However, it did decrease the Ca requirement by about two orders of magnitude. Prolonged stimulation of unstirred platelets by epinephrine led to a 70% decrease in the aggregation response when the platelets were subsequently stirred. Despite their decreased aggregation response, desensitized platelets bound PAC-1 and fibrinogen normally, indicating that the loss of aggregation was not due simply to a decrease in fibrinogen receptor expression. Although desensitization was not affected by pretreatment of the platelets with aspirin, it was partially prevented when extracellular Ca was chelated by EDTA during the long incubation with epinephrine. These studies demonstrate that once platelet alpha 2-adrenergic receptors are occupied by epinephrine, extracellular Ca is involved in initiating the aggregation response by supporting the induction of the fibrinogen receptor and the binding of fibrinogen. Furthermore. Ca-dependent reactions subsequent to fibrinogen binding may be necessary for maximal platelet aggregation and are impaired when platelets become desensitized to epinephrine.     

Glycoprotein Ib and glycoprotein IX are fully complexed in the intact platelet membrane

Two new murine monoclonal antibodies, AK 1 and SZ 1, reactive with the human platelet glycoprotein (GP) Ib-IX complex have been produced by the hybridoma technique. Both AK 1 and SZ 1 immunoprecipitated the GP Ib-IX complex from Triton X-100-solubilized, periodate-labeled platelets. With trypsinized, labeled platelets, AK 1, SZ 1, and FMC 25 (epitope on GP IX) immunoprecipitated a membrane-bound proteolytic fragment of the GP Ib-IX complex consisting of GP IX and an congruent to 25,000 mol wt remnant of the alpha-chain of GP lb disulfide-linked to the beta-subunit. Unexpectedly, although AK 1 and SZ 1 immunoprecipitated purified GP Ib-IX complex, neither antibody immunoprecipitated the individual components of this complex, GP Ib or GP IX. When GP Ib and GP IX were recombined, however, AK 1 and SZ 1 again immunoprecipitated the reformed complex, strongly suggesting that both antibodies were recognizing an epitope present only on the intact complex. Cross-blocking studies indicated that AK 1 and SZ 1 recognized a very similar or identical epitope that was proximal to the epitope for FMC 25. Both AK 1 and SZ 1 bound to a similar number of binding sites (congruent to 25,000) on intact platelets as monoclonal antibodies directed against either GP lb or GP IX. The combined data suggests that GP lb and GP IX are fully complexed in the intact platelet membrane.     

Informant ratings of cognitive decline of elderly people: relationship to longitudinal change on cognitive tests

Formal assessment of cognitive decline with cognitive tests can be difficult, requiring either two measurement points or a comparison of 'hold' with 'don't hold' tests. Informant-based assessment provides an alternative approach because informants can adopt a longitudinal perspective and directly rate cognitive change. A study was carried out to assess the validity of informant ratings collected by means of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). A community sample of 500 subjects aged 74 or over underwent four cognitive tests on two occasions 3½ years apart. On the second occasion, informants filled out the IQCODE. Subjects rated as having moderate or severe decline were found to have greater change on the cognitive tests. These findings support the validity of informant ratings of cognitive decline.