多烯脂肪酸对脑血栓伴高脂血症病人降脂作用的疗效观察

目的：研究多烯脂肪酸胶囊对脑血栓伴高脂血症病人的降脂作用。选血脂康作对照。方法：６０例脑血栓伴高脂血症病人随机分为二组：治疗组（ｎ＝３１）及对照组（ｎ＝２９）。服药前及服药后４周,８周查血脂。结果：⑴服药４周后ＴＣ和ＬＤＬ－Ｃ分别降低２１．０２％和２８．９３％（多烯脂肪酸组）。⑵多烯脂肪酸组降低了３４．０６％的血清ＴＧ水平,效果显,结论：多烯脂肪酸胶囊降ＴＧ和ＬＤＬ－Ｃ水平与血脂康作用相近,其降     

祛痰合剂最大耐受量观察及其对血,尿常规的影响

目的： 观察祛痰合剂的毒性大小。方法： 采用一日内最高允许浓度,最大剂量灌胃测其毒性实验方法。结果： 最大耐受量对小鼠各项指标观察均无影响。结论： 耐受系数为人日用量３６０倍。     

磷酸钙作为佐剂应用在乙肝核酸疫苗中的可能性研究

目的：研究使用磷酸钙作为乙ＤＮＡ疫苗的佐剂,诱导机体免疫反应的可能性,方法：磷酸钙与疫苗ＤＮＡ制备出磷酸钙－ＤＮＡ共沉物,免疫小鼠,检测外周血抗体,观察免疫应答反应,结果：磷酸钙－ＤＮＡ共沉物能激发机体免疫应答反应。结论：佐剂在核酸疫苗的应用值得进一步研究。     

pH电极位置对反流性食管炎酸监测的影响

为探讨ｐＨ电极位置对反流性食管炎酸监测的影响,将６０例反流性食管炎随机分为对照（Ｃ）组和试验（Ｔ）组。 Ｃ组 ３０例用测压法将 ｐＨ电极置于下食管括约肌（ＬＥＳ）上缘 ５ ｃｍ处;Ｔ组 ３０例用 ｐＨ梯度法将电极放于胃食管连接处（ＧＥＪ）上方 ５ ｃｍ处。连续 ２４ ｈ ｐＨ监测。结果显示,Ｃ与Ｔ组前鼻孔至ＧＥＪ平均距离分别为（４６． ２±４．１） ｃｍ与（４６． ５±４． ５） ｃｍ,两者无明显差异（Ｐ＝０． ８）。两组前鼻孔至ＧＥＪ平均距离（４６． ３±４． ３） ｃｍ比 Ｃ组前鼻孔至ＬＥＳ上缘平均距离（４３． ３±３． １） ｃｍ低 ３． ０ ｃｍ（Ｐ＝０． ０００３）。食管酸监测的 ｐＨ＜４,总百分时间和总计分在Ｔ组（８．５和 ４５． ５）和Ｔ组中ＧＥＪ＞ＬＥＳ上缘＋３ ｃｍ和＜－３ｃｍ范围者（１０． ０和 ９９． ３）较Ｃ组（４． ８和 ２６． ３）均有明显增高, Ｐ均＜０． ０１）,而Ｔ组中ＧＥＪ≤ＬＥＳ上缘＋３ ｃｍ和≥－３ ｃｍ范围者（７． １和 ３９． ４）则无明显差异（ Ｐ均＞０． ０５）。研究结果表明,因 ＧＥＪ常比 ＬＥＳ上缘偏低,故以 ＧＥＪ安放电极（尤其是ＧＥＪ＞ＬＥＳ上缘 ＋ ３ｃｍ或＜－ ３ｃｍ范围者）对反流性食管炎行 ｐＨ监测时     

Simultaneous Construct Surface Microstructural and Internal Network-Like Conductive Pathways of Poly(l-lactic acid)/Carbon Nanomaterials Composite Foams

The poly(l -lactic acid) (PLLA)/carbon nanomaterials composite foams with hierarchical surface microstructural and internal conductive pathways are successfully prepared by a simple crystallization-assisted rapid phase separation (CARPS). The dimension and morphology of carbon nanomaterials can induce different crystallization forms to construct the hierarchical surface microstructure, and they are distributed on the phase interface of solvent and non-solvent to form conductive pathways. It is found that the heterogeneous nucleation of nanomaterials promotes a significant increase in crystallinity, and a stacked granular structure formed on the surface promotes the increase of the water contact angle to 148.7°. Foams with interconnecting pore structures contribute to the formation of 85.3% porosity and 12.33 g g⁻¹ oil absorption. Carbon nanomaterials are distributed on the pore walls of the porous foam, which converts the foam from an insulating material to a conducting polymer. Furthermore, the uniform distribution of nanomaterials significantly affects the thermal stability of the PLLA. In belief, the multifunctional biodegradable foam, prepared by a CARPS method, makes it promising for industrial production and has potential applications in electrical conductivity, oil-water separation, and many other fields.     

Performance of point-of care molecular and antigen-based tests for SARS-CoV-2: a living systematic review and meta-analysis

BackgroundMolecular and antigen point-of-care tests (POCTs) have augmented our ability to rapidly identify and manage SARS-CoV-2 infection. However, their clinical performance varies among individual studies.ObjectivesThe evaluation of the performance of molecular and antigen-based POCTs in confirmed, suspected, or probable COVID-19 cases compared with that of laboratory-based RT-PCR in real-life settings.Data sourcesMEDLINE/PubMed, Scopus, Embase, Web of Science, Cochrane Library, Cochrane COVID-19 study register, and COVID-19 Living Evidence Database from the University of Bern.Study eligibility criteriaPeer-reviewed or preprint observational studies or randomized controlled trials that evaluated any type of commercially available antigen and/or molecular POCTs for SARS-CoV-2, including multiplex PCR panels, approved by the United States Food and Drug Administration, with Emergency Use Authorization, and/or marked with Conformitè Europëenne from European Commission/European Union.ParticipantsClose contacts and/or patients with symptomatic and/or asymptomatic confirmed, suspected, or probable COVID-19 infection of any age.Test/sMolecular and/or antigen-based SARS-CoV-2 POCTs.Reference standardLaboratory-based SARS-CoV-2 RT-PCR.Assessment of risk of biasEligible studies were subjected to quality-control and risk-of-bias assessment using the Quality Assessment of Diagnostic Accuracy Studies 2 tool.Methods of data synthesisSummary sensitivities and specificities with their 95% CIs were estimated using a bivariate model. Subgroup analysis was performed when at least three studies informed the outcome.ResultsA total of 123 eligible publications (97 and 26 studies assessing antigen-based and molecular POCTs, respectively) were retrieved from 4674 initial records. The pooled sensitivity and specificity for 13 molecular-based POCTs were 92.8% (95% CI, 88.9–95.4%) and 97.6% (95% CI, 96.6–98.3%), respectively. The sensitivity of antigen-based POCTs pooled from 138 individual evaluations was considerably lower than that of molecular POCTs; the pooled sensitivity and specificity rates were 70.6% (95% CI, 67.2–73.8%) and 98.9% (95% CI, 98.5–99.2%), respectively.DiscussionFurther studies are needed to evaluate the performance of molecular and antigen-based POCTs in underrepresented patient subgroups and different respiratory samples.     

Evidence for direct and indirect mechanisms in the potent modulatory action of interleukin-2 on the release of acetylcholine in rat hippocampal slices

1. The biphasic nature of the potent modulatory action of interleukin-2 (IL-2) on hippocampal acetylcholine (ACh) release was investigated by use of brain slice superfusion.
2. Both the potentiating (10⁻¹³ M) and inhibitory (10⁻⁹ M) effects of IL-2 on hippocampal ACh release were stimulation-dependent and were blocked by a neutralizing IL-2 receptor antibody, suggesting the activation of typical IL-2 receptors in both cases.
3. Tetrodotoxin (TTX; 10 μM) failed to block the potentiation of ACh release induced by a very low concentration of IL-2 (10⁻¹³M) suggesting a direct effect on cholinergic nerve terminals.
4. In contrast, the inhibitory effect seen at a higher concentration (10⁻⁹ M) was TTX-sensitive, and hence indicative of an indirect action.
5. To establish the nature of this intermediate mediator, blockers of nitric oxide synthesis, and of opioid and γ-aminobutyric acid (GABA) receptors were used. Only GABA_A and GABA_B receptor antagonists altered the inhibitory action of IL-2, suggesting the participation of GABA as mediator.
6. Taken together, these results provide further evidence for the potent role of IL-2 in the modulation of cholinergic function in the rat hippocampus.

     

Enhancement of the response to purinergic agonists in P2Y1 transfected 1321N1 cells by antagonists suramin and PPADS

1. We have previously shown that both suramin and pyridoxal-phosphate-6-azophenyl-2′, 4′ disulphonic acid (PPADS) act as antagonists at transfected P2Y₁ receptors. Here we show that under certain experimental conditions these two P2 antagonists can enhance the response to agonists acting at these receptors.
2. The expression of either P2Y₁ or P2Y₂ receptors in 1321N1 human astrocytoma cells results, on a change of medium, in an elevation of basal (no added agonist) accumulation of [³H]-inositol(poly)phosphates([³H]-InsP_x) compared to cells not expressing these receptors. This elevation is much greater in P2Y₁ transfectants than in P2Y₂ transfectants.
3. Both PPADS and suramin reduced this basal level of [³H]-InsP_x accumulation in the P2Y₁ expressing cells.
4. When a protocol was used which required changing the culture medium, antagonists were added at a concentration which reduced the basal accumulation by about 50%, there was a significant stimulation in response to increasing concentrations of 2-methylthioadenosine 5′-triphosphate (2MeSATP), in the absence of antagonists there was no significant effect of the agonist.
5. However, when 2MeSATP was added in the absence of a change of medium and with no antagonist present, there was a several fold increase in [³H]-InsP_x accumulation. These results show that a release of endogenous agonist activity (possibly ATP/ADP) from the P2Y₁ expressing cells can create conditions in which a response to an agonist such as 2MeSATP can only be seen in the presence of a competitive antagonist.

     

Development and in Vitro Evaluation of Systems to Protect Peptide Drugs from Aminopeptidase N

Purpose. Develop and evaluate systems to prevent aminopeptidase N caused enzymatic degradation of perorally administrated peptide drugs. Methods. Bacitracin was covalently bound to the unabsorbable carrier matrix poly(acrylic acid) (paa) in order to avoid any dilution effects of the inhibitor in the intestine as well as systemic toxic side effects. The inhibitory effect of this conjugate, of neutralized paa and N-acetylcysteine was evaluated using a brush border membrane model. Results. Whereas within 6 h of incubation 65.3 ± 3.7 mol/1 of the substrate (L-leucine p-nitroanilide) was hydrolyzed under our assay conditions, this metabolism was reduced to 44.5 ± 6.3 mol/1 and 49.0 ± 8.8 mol/1 (n = 3–5; ± S.D.) using 1.5% bacitracin-polymer conjugate and 0.5% N-acetylcysteine, respectively. The same amount of bacitracin as immobilized to the polymer exhibited a comparably weaker inhibitory effect. Neutralized paa did not inhibit membrane bound aminopeptidase N. Covering the membrane with a thin mucus layer led to a significantly lowered inhibitory effect of all tested agents. Conclusions. The immobilization of enzyme inhibitors to a carrier matrix and the use of N-acetylcysteine as a novel inhibitor are promising strategies in order to overcome the enzymatic barrier caused by membrane bound peptidases. However the use of effective mucolytic agents seems to be a prerequisite.     

Antifungal Activity of a New Triterpenoid Glycoside from Pithecellobium racemosum (M.)

Purpose. In a continuation of our search for novel antifungal compounds from higher plants, the standard extract of the bark of Pithecellobium racemosum was found to have good activity against important AIDS-related opportunistic yeasts. Methods. The extract was subjected to bioguided fractionation using silica gel column chromatography which led to purification of triterpene glycosides. The structures of these compounds were determined by a combination of spectroscopic (IR, NMR, HRMS) and chemical methods. Results. Compound 1 is a new glycoside, 3-O[-L-arabinopyranosyl (1 -2)][-L arabinopyranosyl (1 -6)]2-acetoamido-2-deoxy--D-gluco-pyranosyl oleanolic acid and Compound 2 was identified as the known compound 3-O-[-L-arabinopyranosyl (l-2)]-L-arabinopyranosyl (1-6)] 2-acetamido-2-deoxy--D-glucopyranosyl echinocystic acid. Conclusions. Compound 1 is a new glycoside, 3-O-[-L-arabinopyranosyl (1-2)]-L-arabinopyranosyl (l-6)]-2-acetoamido-2-deoxy--D-glucopyranosyl oleanolic acid and exhibits moderate antifungal activity against T. mentogrophytes, C. albicans and S. cerevisiae with MIC values of 6.25, 12.5 and 12.5 g/ml respectively.