解剖学和影像学观察寰枢关节及相关结构的对比研究

目的:评价解剖学和影像学方法观察寰枢关节(AAJ)及相关结构的优缺点及应用价值。方法:对8例寰枢关节段尸体解剖标本进行解剖学和影像学对比研究,观察椎动脉寰枢段(VA-A)、第1、2脊神经(CN1,CN2)以及AAJ滑膜皱襞(SF)的解剖,测量它们的大小及位置关系值。结果:CN1出椎管后向外下走行于寰椎后弓上缘及VA下缘,CN2出椎管后走行于寰、枢椎后弓之间及VA后。SF存在于寰枢中央前关节6例,寰枢外侧关节5例。VA-A沿AAJ走行,有4个弯曲,其中第2、4个弯曲远离其骨结构。CN1、CN2到VA-A距离范围分别为0.0~2.2 mm、0.0~3.6 mm,VA2个弯曲行程远离AAJ骨结构距离范围分别为0.0~4.8 mm、2.0~7.9 mm,解剖及影像测量值统计学比较差异无统计学意义(P0.05)。结论:解剖学方法有利于观察CN和SF,影像学方法显示VA-A与AAJ清楚。两者具有互补性,得到的测量值相当,结合应用为研究该区域的复杂解剖提供了新的手段。     

孕妇对母乳喂养自信心及其影响因素的研究

目的分析孕妇对母乳喂养自信心现状及其影响因素。方法采用自行设计的基本资料问卷、中文版母乳喂养自信心量表和社会支持量表,对2009年9月至12月在厦门市3所三级甲等医院产科门诊随访的201例孕妇进行母乳喂养自信心及其影响因素研究。结果孕妇对母乳喂养自信心平均水平为(3.50±0.68)分。母乳喂养间接经验、决定时间、爱人对母乳喂养的态度和社会支持度是孕妇对母乳喂养自信心的主要影响因素,其中社会支持对母乳喂养的态度影响最大。结论孕妇对母乳喂养自信心有待提高,护理工作者要充分利用母乳喂养间接经验的模范示范作用,尽早开展以家庭为中心的母乳喂养宣教,并为孕妇提供广泛的社会支持,提高孕妇对母乳喂养的自信心,从而提高母乳喂养率和延长母乳喂养时间。     

Phylogenetic designation of enterovirus 71 genotypes and subgenotypes using complete genome sequences

Human enterovirus 71 (EV-71) is genotyped for molecular epidemiological investigation mainly using the two structural genes, VP1 and VP4. Based on these, EV-71 is divided into three genotypes, A, B and C, and within the genotypes B and C, there are further subgenotypes, B1–B5 and C1–C5. Classification using these genes is useful but gives incomplete phylogenetic information. In the present study, the phylogenetic relationships amongst all the known EV-71 and human enterovirus A (HEV-A) isolates with complete genome sequences were examined. A different tree topology involving EV-71 isolates of subgenotypes, C4 and B5 was obtained in comparison to that drawn using VP1. The nucleotide sequence divergence of the C4 isolates was 18.11% (17–20%) when compared to other isolates of subgenotype C. However, this positions the C4 isolates within the cut-off divergence value of 17–22% used to designate the virus genotypes. Hence, it is proposed here that C4 should be designated as a new genotype D. In addition, the subgenotype B5 isolates had an average nucleotide divergence of only 6.14% (4–8%) when compared to other subgenotype B4 isolates. This places the B5 isolates within the subgenotype B4. It is proposed here that the B5 isolates to be redesignated as B4. With the newly proposed genotype D and inclusion of subgenotype B5 within B4, the average nucleotide divergence between genotypes was 18.99% (17-22%). Inter- and intra-subgenotype average divergences were 12.02% (10–14%) and 3.92% (1–10%), respectively. A phylogenetic tree built using the full genome sequences is robust as it takes into consideration changes in the sequences of both the structural and non-structural genes. Similar nucleotide similarities, however, were obtained if only VP1 and 3D RNA polymerase genes were used. Furthermore, addition of 3D RNA polymerase sequences will also show recombination events. Hence, in the absence of full genome sequences, it is proposed here that a combination of VP1 and 3D RNA polymerase gene sequences be used for initial genotyping of EV-71 isolates.     

WNK-SPAK/OSR1-NCC kinase signaling pathway as a novel target for the treatment of salt-sensitive hypertension

Hypertension is the most prevalent health condition worldwide,affecting~1 billion people.Gordon’s syndrome is a form of secondary hypertension that can arise due to a number of possible mutations in key genes that encode proteins in a pathway containing the With No Lysine[K](WNK)and its downstream target kinases,SPS/Ste20-related proline-alanine-rich kinase(SPAK)and oxidative stress responsive kinase 1(OSR1).This pathway regulates the activity of the thiazide-sensitive sodium chloride cotransporter(NCC),which is responsible for NaCl reabsorption in the distal nephron.Therefore,mutations in genes encoding proteins that regulate the NCC proteins disrupt ion homeostasis and cause hypertension by increasing NaCl reabsorption.Thiazide diuretics are currently the main treatment option for Gordon’s syndrome.However,they have a number of side effects,and chronic usage can lead to compensatory adaptations in the nephron that counteract their action.Therefore,recent research has focused on developing novel inhibitory molecules that inhibit components of the WNK-SPAK/OSR1-NCC pathway,thereby reducing NaCl reabsorption and restoring normal blood pressure.In this review we provide an overview of the currently reported molecular inhibitors of the WNK-SPAK/OSR1-NCC pathway and discuss their potential as treatment options for Gordon’s syndrome.     

Properties of slow early potassium current in neurons of snail Helix pomatia

• 1.1. In isolated neurons of visceral ganglia of snail Helix pomatia a slow early outward current (IAs) was studied using a two-microelectrode voltage clamp technique.
• 2.2. The time of activation and inactivation of I_As at −40 mV were 90–120 msec and 3–5 sec respectively. The removal of inactivation at −120 mV took 2–5 min.
• 3.3. The reversal potential of the I_As was about −80mV in normal saline and was sensitive to the external potassium concentration, changing about 35 mV per fivefold change in potassium over the range from 4 to 20 mM. The results suggest that I_As were due to K⁺.
• 4.4. The I_As persisted in Ca²⁺-free medium and in the presence of Ca²⁺-channels blockers, e.g., Cd²⁺.
• 5.5. The I_As were blocked by 1–10 μM extracellular 4-aminopyridine, 1 mM of tetraethylammonium ions, 1 mM of Ba²⁺, but one was resistant to 1 mM Cs⁺.
• 6.6. 4-aminopyridine had a dual effect on the I_As. It blocked the normal current, and then appeared to increase the inactivated currents.

     

Cytokine production in the central nervous system of Lewis rats with experimental autoimmune encephalomyelitis: dynamics of mRNA expression for interleukin-10, interleukin-12, cytolysin,tumor necrosis factor α and tumor necrosis factor β

The kinetics of mRNA expression in the central nervous system (CNS) for a series of putatively disease-promoting and disease-limiting cytokines during the course of experimental autoimmune encephalomyelitis (EAE) in Lewis rats were studied. Cytokine mRNA-expressing cells were detected in cryosections of spinal cords using in situ hybridization technique with synthetic oligonucleotide probes. Three stages of cytokine mRNA expression could be distinguished: (i) interleukin (IL)-12, tumor necrosis factor (TNF)-β (=lymphotoxin-α) and cytolysin appeared early and before onset of clinical signs of EAE; (ii) TNF-α peaked at height of clinical signs of EAE; (iii) IL-10 appeared increasingly at and after clinical recovery. The early expression of IL-12 prior to the expression of interferon-γ (IFN-γ) mRNA shown previously is consistent with a role of IL-12 in promoting proliferation and activation of T helper 1 (Th1) type cells producing IFN-γ. The TNF-β mRNA expression prior to onset of clinical signs favours a role for this cytokine in disease initiation. A pathogenic effector role of TNF-α was suggested from these observations that TNF-α mRNA expression roughly paralleled the clinical signs of EAE. This may be the case also for cytolysin. IL-10-expressing cells gradually increased to high levels in the recovery phase of EAE, consistent with a function in down-regulating the CNS inflammation. From these data we conclude that there is an ordered appearance of putative disease-promoting and -limiting cytokines in the CNS during acute monophasic EAE.     

Optimization of the Gafchromic™ EBT protocol for IMRT QA

Quality assurance of external beam (radio)therapy (EBT) requires tools with specific characteristics. A radiochromic film dubbed “Gafchromic? EBT” (G-EBT) that is particularly suited for external beam therapy because of its features was introduced in 2004. Its characteristics, especially the high spatial resolution, make it suitable for measurement of dose distributions in radiotherapy, especially intensity-modulated radiation therapy (IMRT). While several aspects of the film characteristics have been previously reported separately, we present a comprehensive evaluation centered on practical IMRT verification, leading to an optimized protocol. Therefore the constancy within one batch, the relationship between optical density (OD) and dose (dose range between 1.4Gy and 8.4Gy) and the dose rate dependence for four dose rates (55, 108, 217, 441 MU/min) were investigated. In addition to these characteristics, energy dependence between two energies (50 kV and 6 MV), tissue equivalency, post irradiation coloration over one month, pressure and temperature sensitivity were evaluated. We then optimized the protocol using the G-EBT films, in combination with an EPSON-Expression? 1680pro flatbed scanner, for IMRT QA, while either striving to keep the compound error as small as possible or trying to reduce evaluation time. As a basis for this protocol optimization, the characteristics of the scanner (such as inhomogeneity of the scanning field) and its software (such as consequences of extracting only the red color channel) had to be determined first. The interaction of film and scanner (variation of the OD depending on the scanning direction or the scanning resolution) was assessed as well. Using the optimized protocol for IMRT QA, the compound error could be reduced to approximately 2% for a quality-driven approach and maximum 5.5% for an approach attempting to reduce procedure time. While the quality-driven approach provides appropriate accuracy for individual patient QA, the procedure-time driven approach can only be used for preliminary measurements.     

Historical Brief on Composition of Human Meibum Lipids

Meibomian glands (MG) secrete an oily substance, meibum, that spreads across the ocular surface and mixes with secretions produced by other ocular structures to create a thin film. The protective efficacy of the tear film is believed to be related to the chemical composition of the lipid layer. We reviewed the literature describing the composition of human MG secretions and have provided an overview on methods of collecting meibum samples, methods of lipid analyses, and the results obtained in previous studies. The usefulness and quality of the data obtained about meibum depend on proper sampling and the analytical techniques used. Historically, several methods have been developed, which have yielded contradictory data regarding meibum sample collection and analytical techniques. Based on review of the literature, the major lipids present in meibum are of nonpolar origin: waxes, sterols, and sterol esters, followed by triacylglycerides and fatty acids. The amphiphilic lipids, diacylglycerides, were reported in fewer studies, and monoacylglycerides were reported in only two. Information on the composition of the polar lipids is more controversial. Meibum phospholipids were found in small amounts (16% or less) in some studies, but not in others. Thus, meibum is a complex mixture of lipid molecules. Historical analytical inconsistencies may be partly explained by limitations of past analytical procedures and by the consideration that the tear film lipid layer may have contributing sources other than meibum.     

Immunology: Paper alert

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.