Glucose transport and metabolism in the perfused hindquarters of lean and obese-hyperglecemic (db/db) mice effects of insulin and electrical stimulation

Changes in glucose transport and metabolism in skeletal muscles of the obese-diabetic mice (db/db) was characterized using the perfused mouse hindquarter preparation. Metabolism of [5-³H]glucose, uptake of 3-O-[methyl-³H]glucose (methylglucose) and [2-¹⁴C]deoxyglucose (deoxyglucose) was studied under resting, electrically stimulated contracting, and insulin-stimulated conditions. Basal rate of methylglucose uptake was 255 ± 18 and 180 ± 9 μl/15 min per ml intracellular fluid space for lean and db/db mice, respectively. The V_? of methylglucose transport was decreased with no change in K_m in the db/db mice. Both electrical stimulation and insulin (1/mU/ml) increased methylglucose uptake rate 2-fold in both lean and obese mice. We observed no significant change in insulin sensitivity in the db/db mice in stimulating methylglucose uptake which was subnormal under all conditions. Similar results were obtained using deoxyglucose. Likewise, uptake of glucose and ³H₂O production from [5-³H]glucose were significantly reduced, both at rest and during electrically stimulated contraction in the db/db mouse. However, lactate production in the electrically stimulated db/db mouse preparations was not significantly different from that in the lean mice. These data suggest a major contribution from an impaired glucose transport activity to the reduction in glucose metabolism in the db/db mouse skeletal muscle.     

Effects of electrical stimulation before or after in vitro fertilization on sperm penetration and pronuclear formation of pig oocytes

The effects of exposure of pig oocytes to an electrical pulse on sperm penetration and pronuclear formation were determined before or after in vitro fertilization (IVF). After in vitro maturation (IVM) or after collection from oviducts of unmated gilts, pig oocytes either were not exposed or were exposed to an electrical pulse (a 10 sec pulse at 4.0 V mm^?1 AC followed by a 30 μsec pulse at 120 V mm^?1 DC), followed 30 min later by IVF. The incidence of male pronuclear formation of both IVM and in vivo-matured oocytes at 12 hr after insemination was decreased from 59% and 100%, respectively, to 2% and 36%, respectively, by the electrical pulse, but the penetration rates (88–100%) and polyspermic rates (79–100%) were not affected by exposure to an electrical pulse. Similarly, when pig IVM oocytes were exposed to an electrical pulse at 6 hr after insemination, electrical activation did not decrease penetration rates (93% vs. 90%), polyspermic rates (83% vs. 91%), or number of spermatozoa in penetrated oocytes (4.0 ± 0.5 vs. 4.6 ± 0.5) but did decrease the rate of male pronuclear formation from 58% to 18%. When oocytes were examined at 6 hr after insemination, 75% of them had been penetrated and resumed meiotic progression, but all sperm heads in penetrated oocytes were fully condensed or only partially decondensed. The percentage of penetrated eggs with multiple female pronuclei was increased when oocytes were exposed to an electrical pulse in all experimental series. In summary, electrical activation of pig oocytes before or just after IVF does not prevent sperm penetration but does inhibit male pronuclear formation and increases the formation of multiple female pronuclei. © 1993 Wiley-Liss, Inc.     

自体外周血干细胞移植联合髓芯减压治疗早中期股骨头缺血性坏死的临床研究

目的对比研究单纯股骨头髓芯减压与联合自体外周血干细胞移植治疗早中期股骨头缺血性坏死（ANFH）的临床疗效。方法 2004年10月至2012年3月期间就诊于福建省龙岩市第一医院,经影像学检查及术后病理检查确诊为ANFH的患者90例。A组采用单纯髓芯减压共34例,男22例,女12例,年龄22~62岁（中位年龄41.5岁）。B组采用髓芯减压联合自体外周血干细胞移植（用rhG-CSF皮下注射4 d进行外周血干细胞动员,第5天分离外周造血干细胞混悬液。在髓芯减压基础上沿减压隧道注入自体外周血干细胞10~15 ml）56例,男35例,女21例,年龄21~62岁（中位年龄39岁）。按世界骨髓循环研究学会（ARCO）国际骨坏死标准：A组：Ⅰ期7髋,Ⅱ期26髋,Ⅲ期17髋;B组：Ⅰ期10髋,Ⅱ期50髋,Ⅲ期29髋。术后及随访期间进行Harris评分和疼痛视觉模拟（VAS）评分,对X线片、CT及MRI检查结果进行评估。两组Harris评分和VAS评分比较用成组t检验。结果 A组34例,B组49例随访13~89个月,平均38.5个月。术后3、6、12个月与术前的Harris评分比较有明显提高,VAS评分有明显的下降;术前、术后3个月两时间点的A、B组Harris评分比较差异无统计学意义（t=0.342、0.628,P=0.781、0.516）;术后6、12个月的B组评分优于A组（t=2.991、7.753,P=0.009、0.001）。术后12个月A、B两组T1相低信号区所占股骨头体积的比例分别为（17.24±3.71）﹪和（12.11±3.14）﹪,差异有统计学意义（t=4.360,P=0.001）。结论髓芯减压联合自体外周血干细胞移植治疗早中期ANFH,可显著减轻关节疼痛,改善股骨头血液供应,明显恢复关节功能,加速病灶区骨组织修复,有效防止股骨头进一步塌陷。     

Redox control of angiogenic factors and CD31-positive vessel-like structures in mouse embryonic stem cells after direct current electrical field stimulation

The molecular mechanisms driving angiogenesis in tissues derived from embryonic stem (ES) cells are currently unknown. Herein we investigated the effects of direct current (DC) electrical field treatment on endothelial cell differentiation and angiogenesis of mouse ES cells. Treatment of ES cell-derived embryoid bodies with field strengths ranging from 250 V/m to 750 V/m, applied for 60 s, dose-dependently increased the capillary area staining positive for the endothelial-specific marker platelet endothelial cell adhesion molecule-1 (PECAM-1), indicating stimulation of endothelial cell differentiation and angiogenesis. Consequently, increased expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) within 24 h was observed. Electric field treatment raised reactive oxygen species (ROS) generation for at least 48 h, which was blunted by NADPH-oxidase inhibitors diphenylen iodonium chloride (DPI) as well as 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), and increased the expression of NADPH-oxidase subunits p22-phox, p47-phox, p67-phox, and gp91-phox within 24 h. Electrical field treatment resulted in activation of extracellular regulated kinase 1,2 (ERK1,2), p38, as well as c-Jun NH2-terminal kinase (JNK). Pretreatment with the JNK inhibitor SP600125 resulted in a significant decrease in capillary areas under control conditions as well as under conditions of electrical field treatment, whereas the p38 inhibitor SB203580 was without effects. By contrast, the ERK1,2 antagonist UO126 inhibited electrical field-induced angiogenesis, whereas angiogenesis under control conditions was unimpaired. The increase in capillary areas and VEGF expression as well as activation of JNK and ERK1,2 was significantly inhibited in the presence of the free radical scavenger vitamin E underscoring the role of ROS in electrical field-induced angiogenesis of ES cells.     

In situ demonstration of changes in the preoptico-neurohypophysical complex after electrical stimulation of the olfactory tract in the catfish Clarias batrachus (Linn.)

Summary Electrical stimulation (five minutes) of the olfactory tract in Clarias batrachus results in total degranulation of the neurons of the pars magnocellularis (PMC), while a ten-minute treatment is required for degranulation of the entire nucleus preopticus (NPO). The preoptico-neurohypophysial tract (PNT) and neurohypophysis (NH) of these animals are feebly stained. By 15 minutes of stimulation the neurosecretory material (NSM) is depleted from the entire system; only a few granules may be present in the PNT and NH. A delay for 30 minutes after a 15-minute stimulation causes restoration of NSM in the NH and PNT, while a 60-minute delay results in a higher degree of accumulation of NSM.

---

Zusammenfassung Eine 5 min dauernde elektrische Stimulierung des Tractus olfactorius von Clarias batrachus bewirkt eine vollständige Entgranulierung der sekretorischen Neurone der Pars magnocellularis nuclei praeoptici (PMC), während für die Entgranulierung des ganzen Nucleus praeopticus (NPO) eine Stimulierungsdauer von 10 min erforderlich ist. Die Neurosekretfärbung des Tractus praeoptico-neurohypophyseus (PNT) und der Neurohypophyse (NH) fällt bei diesen Versuchstieren mäßig aus. Nach 15 minütiger Stimulierung ist das färbbare Material (NSM) im ganzen neurosekretorischen System weitgehend abgebaut; nur noch wenige Granula finden sich im PNT und in der NH. Eine Ruhephase von 30 min, die auf eine 15 minütige Stimulierung folgt, führt zum Wiederauftreten des NSM in der NH und im PNT, während nach einer 60 minütigen Pause die Menge des NSM weiter zunimmt.

     

Biomass accumulation and clogging in biotrickling filters for waste gas treatment. Evaluation of a dynamic model using dichloromethane as a model pollutant

A dynamic model is developed that describes the degradation of volatile acidifying pollutants in biotrickling filters (BTFs) for waste gas purification. Dynamic modelling enables the engineer to predict the clogging rate of a filter bed and the time it takes the BTF to adapt to changes in its inlet concentration. The most important mechanisms that govern the behaviour of the BTF are incorporated in the model. The time scale of the accumulation of biomass in a filter is investigated, and an approach is presented that can be used to estimate how long a BTF can be operated before its packing has to be cleaned. A three-month experiment was carried out to validate the model, using dichloromethane (DCM) as a model acidifying pollutant. Valuable experimental data about biomass accumulation and liquid hold-up in the reactor were obtained with an experimental set-up that allows the continuous registration of the weight of the BTF. The results show that in BTFs eliminating DCM from a waste gas, clogging is not to be expected up to concentrations of several g/m3. Model calculations based on the measurements also suggest that the maximum carbon load that can safely be applied per unit void packing volume should not exceed 0.5-1.6 C mol/(m3. h), depending on the density of the biofilm formed. The model is a good predictor of the elimination of the pollutant in the system, the axial gas and liquid concentration profiles, the axial biomass distribution, and the response of the system upon a stepwise increase in the DCM inlet concentration. The influence of the buffer concentrations in the liquid phase upon the performance of the BTF is investigated.     

不同频率电刺激膈神经导致膈肌肌浆网Ca~(2 )-ATPase和Ca~(2 )释放-摄取动力学改变

研究不同频率慢性电刺激（ＣＥＳ）后兔膈肌肌浆网（ＳＲ）Ｃａ２＋－ＡＴＰａｓｅ活性以及ＳＲ Ｃａ２＋摄取－释放动力学对不同频率ＣＥＳ的适应性变化。建立不同频率ＣＥＳ组;用定磷法测定ＳＲ Ｃａ２＋－ＡＴＰａｓｅ活性;用Ｆｕｒａ－２荧光法测定ＳＲ　Ｃａ２＋摄取－释放动力学。与对照组比较,慢性低频电刺激１０ Ｈｚ和２０Ｈｚ组的ＳＲ　Ｃａ２＋－ＡＴＰａｓｅ活性明显降低（Ｐ＜０．０１）,Ｃａ２＋释放－摄取动力学也显著降低（Ｐ＜０．０１）;慢性高频电刺激５０ Ｈｚ和１００Ｈｚ组的ＳＲ Ｃａ２＋－ＡＴＰａｓｅ活性则显著升高（Ｐ＜０．０１）,Ｃａ２＋释放－摄取动力学亦明显升高（Ｐ＜０．０１）。实验提示,ＣＥＳ后不同频率ＣＥＳ导致膈肌ＳＲＣａ２＋－ＡＴＰａｓｅ、Ｃａ２＋摄取－释放动力学产生不同的适应性变化;对不同功能状态的膈肌应用不同频谱的慢性电刺激可能具有重要的临床意义。