Cyclic neutropenia (CN): a clue to the control of granulopoiesis

A simple quantitative feedback model of granulopoiesis is presented and discussed within the framework of existing data on granulopoiesis in both normals and patients with cyclic neutropenia (CN). The model assumes that the controlled compartment is the bone marrow pool of mature neutrophils (PMNs), which sends a negative feedback signal to the mitotic pool of early granulocyte precursors (i.e., CFU-C, myeloblasts, etc.) thus controlling the granulocyte production rate. Three parameters are found to play important roles in determining the response of the system to perturbations. These are: TM, the granulocyte maturation time; a, a parameter reflecting the strength of the negative feedback exerted by mature PMNs on the granulocyte production rate; and b, a parameter describing the leakiness of the bone marrow for PMN egress. It is shown that depending on the relative magnitudes of a and b, the system will either respond to perturbations with a damped oscillation (a less than b: the normal state) or with a sustained oscillation (a greater than b: the CN state). In both cases, the oscillation period is found to approximately equal 2TM. Deductions of the values of a, b, and TM from experimental data are consistent with the predictions of the model and show an increased value of a in CN relative to the normal state. This suggests an overly active feedback mechanism as the pathophysiologic basis of CN. In addition, the model can explain how various therapeutic agent correct CN and also provides insight into why other hematologic cell lines and CSA oscillate in CN.     

大豆异黄酮对大鼠骨密度及骨代谢生化指标的影响

目的 研究植物雌激素-大豆异黄酮对大鼠骨密度及骨代谢生化指标的影响。方法 将断乳Wister大鼠按体重随机分为4组，分别给予基础饲料和不同剂量的大豆异黄酮。每周称体重，调整给食量。12周后处死大鼠，取脏器称重，计算脏体比值；剥离股骨，测骨矿物质含量(BMC)、骨密度(BMD)和骨钙、骨磷的含量；对血清中骨形成生化指标碱性磷酸酶、骨钙素和骨吸收生化指标抗酒石酸酸性磷酸酶进行检测，同时测定雌激素-雌二醇(E2)的含量。结果 具有弱雌激素样作用的大豆异黄酮对实验大鼠的子宫、卵巢无刺激作用。与对照组相比，给予大豆异黄酮能提高BMC、BMD及骨钙含量，并随剂量的增加而增大。大豆异黄酮可影响骨代谢，高剂量的大豆异黄酮(41．6mg／kg)同时抑制骨形成和骨吸收，使骨转化率降低，但对骨吸收的作用大于骨形成。给予大豆异黄酮组血清雌激素水平大于对照组。结论 大豆异黄酮通过调整骨代谢生化指标的活性，提高大鼠的骨钙含量和骨密度，可预防骨质疏松的发生。     

Sit-to-stand performance depends on sensation,speed, balance,and psychological status in addition to strength in older people

BACKGROUND: Sit-to-stand (STS) performance is often used as a measure of lower-limb strength in older people and those with significant weakness. However, the findings of recent studies suggest that performance in this test is also influenced by factors associated with balance and mobility. We conducted a study to determine whether sensorimotor, balance, and psychological factors in addition to lower-limb strength predict sit-to-stand performance in older people. METHODS: Six hundred and sixty nine community-dwelling men and women aged 75-93 years (mean age 78.9, SD = 4.1) underwent quantitative tests of strength, vision, peripheral sensation, reaction time, balance, health status, and sit-to-stand performance. RESULTS: Many physiological and psychological factors were significantly associated with sit-to-stand times in univariate analyses. Multiple regression analysis revealed that visual contrast sensitivity, lower limb proprioception, peripheral tactile sensitivity, reaction time involving a foot-press response, sway with eyes open on a foam rubber mat, body weight, and scores on the Short-Form 12 Health Status Questionnaire pain, anxiety, and vitality scales in addition to knee extension, knee flexion, and ankle dorsiflexion strength were significant and independent predictors of STS performance. Of these measures, quadriceps strength had the highest beta weight, indicating it was the most important variable in explaining the variance in STS times. However, the remaining measures accounted for more than half the explained variance in STS times. The final regression model explained 34.9% of the variance in STS times (multiple R =.59). CONCLUSIONS: The findings indicate that, in community-dwelling older people, STS performance is influenced by multiple physiological and psychological processes and represents a particular transfer skill, rather than a proxy measure of lower limb strength.     

成人动脉血气分析标本采集技术的研究进展

本文在文献回顾的基础上对目前成人动脉血气分析采血部位、采血用具、穿刺方法等情况进行归纳分析,旨在为临床护士采集血气分析标本提供参考。     

A Preliminary Formula to Predict Timing of Symptom Resolution for Collegiate Athletes Diagnosed With Sport Concussion

ContextSymptom presentation and recovery after sport concussion (SC) are variable. Empirically based models documenting typical symptom duration would assist health care providers in managing return to play after SC.ObjectiveTo develop a prediction model for SC symptom duration.DesignCross-sectional study.SettingTwo National Collegiate Athletic Association Division I university laboratories.Intervention(s)Participants completed the Revised Head Injury Scale (HIS-r), Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), and Sensory Organization Test within 24 hours of SC diagnosis.ResultsThe final formula consisted of the HIS-r''s self-reported neck pain, drowsiness, tingling, and nervousness duration and ImPACT total symptom severity (R = 0.62, R² = 39%, R²_adj = 34.2%, P < .001). Approximately 29% (R²_cv = 29%) of the variance associated with total days symptomatic after SC was explained by our preliminary formula when cross-validated. The current formula correctly identified 76% of participants who recovered within 10 days of injury.ConclusionsOur results suggest that self-reported duration of 4 symptoms during the initial 24 hours after injury along with total symptom severity as measured by ImPACT accounted for a considerable amount of variance associated with days symptomatic after SC in collegiate athletes. Until the formula is cross-validated in a college-aged sample, caution is warranted in using it clinically.Key Words: traumatic brain injuries, prediction, prolonged recovery, symptom severity, symptom duration

Key Points

• A formula to predict symptom resolution after sport concussion primarily consisting of initial symptom duration and severity correctly identified 76% of National Collegiate Athletic Association Division I collegiate athletes who recovered within 10 days.
• Before it can be used clinically, the formula must be cross-validated on larger samples.

The clinical presentation of and recovery from sport concussion (SC) are variable among athletes. Recovery curves based on animal models suggest the metabolic vulnerability associated with concussion resolves within approximately 7 to 10 days.^1,2 During this period of metabolic dysfunction, athletes experience neurocognitive and motor deficits as well as a constellation of symptoms.^3–5 These sequelae serve as markers that clinicians can measure to track recovery and make informed return-to-play and return-to-learn decisions.⁶The resolution of motor (eg, postural stability) and neurocognitive (eg, memory, reaction time, information-processing speed) deficits, along with self-reported symptoms (eg, headache, nausea, dizziness), varies based on a number of factors. These factors include age, sex, background history, comorbid conditions, and signs and symptoms reported or observed at the time of injury.^7–12 For example, in terms of age, only 50% of high school athletes (14–18 years of age) were reported to recover from SC in approximately 7 days, whereas 90% of adult athletes ≥18 years of age recovered in 7 days.^8,13–15 Regarding sex differences, Covassin et al¹⁶ observed that female high school athletes may take up to 14 days to recover in terms of memory and processing speed after concussion. In a separate study, Covassin et al¹² noted that concussed high school- and college-aged females consistently demonstrated higher symptom levels than male participants up to 14 days after concussion.Though the majority of concussion symptoms in older athletes resolve in ≤7 days of injury, approximately 10% of concussed athletes experience persistent symptoms up to 3 months after their diagnosis.¹⁷ Additionally, a subset of patients may experience 3 or more postconcussion symptoms for 3 months or longer, which is classified as postconcussion syndrome (PCS). Babcock et al¹⁸ found that 29% of pediatric concussion patients diagnosed in the emergency department for whom sport was the primary mechanism of injury (35%) were later diagnosed with PCS, which equates to 105 000 cases of pediatric PCS annually in the United States. The authors suggested that being able to prospectively identify candidates at risk for PCS would assist clinicians in discharge planning (eg, education, medications, and ongoing follow-up), ultimately resulting in improved patient outcomes.Studies examining predictors of SC recovery have usually addressed the dichotomy of typical recovery (7–13 days) versus protracted recovery.^3,12 Protracted recovery has been defined as resolution of SC lasting longer than 14,¹⁰ 21,¹¹ 45, or 90 days.^17,19 Several predictors, including loss of consciousness (LOC), posttraumatic amnesia (PTA), retrograde amnesia, total symptom severity, dizziness severity, and headache severity, have been associated with a 1.8- to 6-fold increase in risk for protracted recovery.^11,17,18 Of these predictors, LOC and amnesia are points of debate because of their infrequent occurrence and questionable relationship with injury severity and recovery.^8,11,20The objective of our study was to determine if the number of days an athlete reported concussion-related symptoms could be predicted from dependent variables derived from clinical measures commonly used to manage this injury. The ability to determine how many days an athlete will report SC-related symptoms may assist clinicians by allowing identification of athletes at risk for prolonged recoveries and institution of the appropriate medical and psychosocial infrastructure to assist in a full recovery.     

Local application of lactoferrin promotes bone regeneration in a rat critical‐sized calvarial defect model as demonstrated by micro‐CT and histological analysis

Lactoferrin is a multifunctional glycoprotein with therapeutic potential for bone tissue engineering. The aim of this study was to assess the efficacy of local application of lactoferrin on bone regeneration. Five‐millimetre critical‐sized defects were created over the right parietal bone in 64 Sprague–Dawley rats. The rats were randomized into four groups: group 1 (n  =  20) had empty defects; group 2 (n  =  20) had defects grafted with collagen gels (3 mg/ml); group 3 (n  =  20) had defects grafted with collagen gels impregnated with bovine lactoferrin (10 μg/gel); and group 4 (n  =  4) had sham surgeries (skin and periosteal incisions only). The rats were sacrificed at 4 or 12 weeks post‐operatively, and the calvaria were excised and evaluated with micro‐CT (Skyscan 1172) followed by histology. The bone volume fraction (BV/TV) was higher in lactoferrin‐treated animals at both timepoints, with groups 1, 2, 3 and 4 measuring 10.5  ±  1.1%, 8.6  ±  1.4%, 16.5  ±  0.6% and 24.27  ±  2.6%, respectively, at 4 weeks (P  <  0.05); and 12.2  ±  1.3%, 13.6  ±  1.5%, 21.9  ±  1.2% and 29.3  ±  0.8%, respectively, at 12 weeks (P  <  0.05). Histological analysis revealed that the newly formed bone within the calvarial defects of all groups was a mixture of woven and lamellar bone, with more bone in the group treated with lactoferrin at both timepoints. Our study demonstrated that local application of lactoferrin significantly increased bone regeneration in a rat critical‐sized calvarial defect model. The profound effect of lactoferrin on bone regeneration has therapeutic potential to improve the poor clinical outcomes associated with bony non‐union. LF In Vivo JTERM Authors Contributions. Copyright © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.     

北京市新农合大病保险实施效果分析与评价

目的:测算分析北京市新农合大病保险对患者疾病经济负担的减轻作用,对制度实施效果进行评价。方法:按照经济发展水平和大病保险承办方式选取北京市三个区县,再从中选择大病患者较多的2~3个乡镇。通过与大病保险管理者进行访谈,了解其运行现状;对样本乡镇全部大病患者进行问卷调查了解患者主观感受,收到有效问卷497份。利用新农合管理中心信息平台测算患者疾病经济负担。对定量和定性资料分别采用统计分析与主题框架法进行分析。结果:经大病保险报销,三个区县大病患者平均自付费用明显减轻,实际补偿比均有不同程度的提高,但灾难性卫生支出情况无显著改善。结论:应通过提高大病保险起付线与报销比例,拓宽报销目录等举措提高其补偿水平,重点缓解极重患者疾病经济负担。     

Evidence that both long-acting thyroid stimulator and long-acting thyroid stimulator-protector stimulate the human thyroid gland.

Thyroid-stimulating immunoglobulins were prepared from two potent sera, one contained long-acting thyroid stimulator (LATS) and the other contained both LATS and LATS-protector (LATS-P). The potencies of the immunoglobulin G (IgG) preparations were estimated in the McKenzie assay. The accumulation of cyclic AMP in mouse thyroid lobes was stimulated only by LATS--IgG; LATS-P--IgG was inactive. In contrast, both LATS-IgG and LATS-P--IgG were equally effective in slices of human thyroid.     

Effects of intravenous glucose on whole body leucine dynamics, studied with 1-13C-leucine, in healthy young and elderly adults

We examined whole body leucine metabolism in healthy young and elderly adults while in the postabsorptive state and during an intravenous glucose administration at two rates. Leucine flux, incorporation into whole body protein, and oxidation were estimated from a continuous intravenous infusion of L-[1-13C]leucine and determination of 13C enrichment in plasma leucine and expired air. Per unit of body weight, leucine flux and rates of incorporation into protein were similar in young and old men. Old women showed lower rates compared with young women. Rates were similar for both age groups when expressed per unit of total body water and/or of muscle protein mass. Intravenous glucose infusion (4 mg . kg-1 . min-1) reduced plasma leucine levels and flux similarly in both age groups. Thus, age-related differences in muscle mass and sensitivity of peripheral tissues to insulin-mediated glucose uptake and metabolism are not paralleled by alterations in whole body leucine kinetics in the postabsorptive state.     

高血压患者心脏变时性功能不良及其意义

目的:探讨原发性高血压(EH)患者心脏变时性功能不良(CI)及其意义。方法:随机选择EH患者60例,行活动平板运动试验,记录心率、血压变化,运动时间(time)、代谢当量(METs);计算2级运动的心率变时性反应指数(CRI2)、最大心率收缩压二项乘积(RPP)和心肌耗氧量(MV.O2)并与正常对照组40例比较。结果:EH组峰值心率及心率上升幅度小于对照组(148.75±11.81):(154.27±12.05)次/min,(67.44±13.37):(74.12±14.43)次/min,P<0.05;CRI2低于对照组(0.94±0.22):(1.03±0.15),P<0.05;EH组CI的人数共29例(48.33%)明显多于对照组7例(17.5%),P<0.005,其中CRI2<0.8的人数20例(33.33%),CRI2>1.3的人数9例(15%),对照组为6例(15%)、1例(2.5%),两组间有显著性差异P<0.05;表明EH组存在CI;EH组运动时间(time)缩短(8.78±1.87):(9.77±1.88)min,P<0.05;运动贮量(METs)降低(9.21±1.39):(9.82±1.48),P<0.05;而RPP,MV.O2分别高于对照组[(26484.64±3573.49):(24118.39±3060.76),(30.78±5.0):(27.47±4.23)ml/kg.min,P<0.001]。结论:EH患者存在CI,提示有心脏自主神经损害,临床应引起重视。