Physiology and cell biology of acupuncture observed in calcium signaling activated by acoustic shear wave

This article presents a novel model of acupuncture physiology based on cellular calcium activation by an acoustic shear wave (ASW) generated by the mechanical movement of the needle. An acupuncture needle was driven by a piezoelectric transducer at 100?Hz or below, and the ASW in human calf was imaged by magnetic resonance elastography. At the cell level, the ASW activated intracellular Ca(2+) transients and oscillations in fibroblasts and endothelial, ventricular myocytes and neuronal PC-12 cells along with frequency-amplitude tuning and memory capabilities. Monitoring in vivo mammalian experiments with ASW, enhancement of endorphin in blood plasma and blocking by Gd(3+) were observed; and increased Ca(2+) fluorescence in mouse hind leg muscle was imaged by two-photon microscopy. In contrast with traditional acupuncture models, the signal source is derived from the total acoustic energy. ASW signaling makes use of the anisotropy of elasticity of tissues as its waveguides for transmission and that cell activation is not based on the nervous system.     

Amyloid histology stain for rapid bacterial endospore imaging

Bacterial endospores are some of the most resilient forms of life known to us, with their persistent survival capability resulting from a complex and effective structural organization. The outer membrane of endospores is surrounded by the densely packed endospore coat and exosporium, containing amyloid or amyloid-like proteins. In fact, it is the impenetrable composition of the endospore coat and the exosporium that makes staining methodologies for endospore detection complex and challenging. Therefore, a plausible strategy for facile and expedient staining would be to target components of the protective surface layers of the endospores. Instead of targeting endogenous markers encapsulated in the spores, here we demonstrated staining of these dormant life entities that targets the amyloid domains, i.e., the very surface components that make the coats of these species impenetrable. Using an amyloid staining dye, thioflavin T (ThT), we examined this strategy. A short incubation of bacillus endospore suspensions with ThT, under ambient conditions, resulted in (i) an enhancement of the fluorescence of ThT and (ii) the accumulation of ThT in the endospores, affording fluorescence images with excellent contrast ratios. Fluorescence images revealed that ThT tends to accumulate in the surface regions of the endospores. The observed fluorescence enhancement and dye accumulation, coupled with the sensitivity of emission techniques, provide an effective and rapid means of staining endospores without the inconvenience of pre- or posttreatment of samples.     

Cervical spine instability following cervical laminectomies for Chiari II malformation: a retrospective cohort study

Objective  The treatment of symptomatic Chiari II malformations typically involves multilevel cervical laminectomies in very young children. These patients are at significant risk of cervical instability. The purpose of this study was to determine the incidence and significance of cervical instability after multilevel cervical laminectomies in a cohort of patients decompressed for Chiari II malformation. Methods  Postoperative dynamic lateral cervical spine radiographs were obtained on pediatric patients who had multilevel cervical laminectomies for symptomatic Chiari II malformations. Postoperative cervical spine instability was determined radiographically using published criteria. Clinical instability and need for cervical fusion were also assessed. Results  Nine patients met inclusion criteria for the study. Five of the nine patients (56%) showed evidence of radiographic instability of their cervical spines following surgery for their Chiari II malformations, according to the criteria used. No patient showed evidence of clinical instability or required cervical fusion. Conclusion  Radiographic evidence of cervical spine instability following multilevel cervical laminectomies for Chiari II is common but may be of minimal clinical significance. The reason for the lack of clinical instability in what might be considered high-risk patients is not understood.     

Volumetric and Functional Recovery of the Remnant Liver After Major Liver Resection with Prior Portal Vein Embolization

Introduction  Portal vein embolization is an accepted method to increase the future remnant liver preoperatively. The aim of this study was to assess the effect of preoperative portal vein embolization on liver volume and function 3 months after major liver resection. Materials and methods  This is a retrospective case-control study. Data were collected of patients who underwent portal vein embolization prior to (extended) right hemihepatectomy and of control patients who underwent the same type of resection without prior portal vein embolization. Liver volumes were measured by computed tomography volumetry before portal vein embolization, before liver resection, and 3 months after liver resection. Liver function was assessed by hepatobiliary scintigraphy before and 3 months after liver resection. Results  Ten patients were included in the embolization group and 13 in the control group. Groups were comparable for gender, age, and number of patients with a compromised liver. The mean future remnant liver volume was 33.0 ± 8.0% prior to portal vein embolization in the embolization group and 45.6 ± 9.1% in the control group (p < 0.01). Prior to surgery, there were no significant differences in future remnant liver volume and function between the groups. Three months postoperatively, the mean remnant liver volume was 81.9 ± 8.9% of the initial total liver volume in the embolization group and 79.4 ± 11.0% in the control group (p > 0.05). Remnant liver function increased up to 88.1 ± 17.4% and 83.3 ± 14% respectively of the original total liver function (p > 0.05). Conclusion  Preoperative portal vein embolization does not negatively influence postoperative liver regeneration assessed 3 months after major liver resection. No grant support. Paper presented at the SSAT, Chicago, June 1, 2009.     

Interaction Effect of Genetic Polymorphisms in Glucokinase (GCK) and Glucokinase Regulatory Protein (GCKR) on Metabolic Traits in Healthy Chinese Adults and Adolescents

OBJECTIVE— Recent studies in European populations have reported a reciprocal association of glucokinase regulatory protein (GCKR) gene with triglyceride versus fasting plasma glucose (FPG) levels and type 2 diabetes risk. GCKR is a rate-limiting factor of glucokinase (GCK), which functions as a key glycolytic enzyme for maintaining glucose homeostasis. We examined the associations of two common genetic polymorphisms of GCKR and GCK with metabolic traits in healthy Chinese adults and adolescents.RESEARCH DESIGN AND METHODS— Two single nucleotide polymorphisms (SNPs), rs780094 at GCKR and rs1799884 at GCK, were genotyped in 600 healthy adults and 986 healthy adolescents. The associations of these SNPs with metabolic traits were assessed by linear regression adjusted for age, sex, and/or BMI. We also tested for the epistasis between these two SNPs and performed a meta-analysis among European and Asian populations.RESULTS— The T-allele of GCKR rs780094 was associated with increased triglycerides (P = 5.4 × 10⁻⁷), while the A-allele of GCK rs1799884 was associated with higher FPG (P = 3.1 × 10⁻⁷). A novel interaction effect between the two SNPs on FPG was also observed (P = 0.0025). Meta-analyses strongly supported the additive effects of the two SNPs on FPG and triglycerides, respectively.CONCLUSIONS— In support of the intimate relationship between glucose and lipid metabolisms, GCKR and GCK genetic polymorphisms interact to increase FPG in healthy adults and adolescents. These risk alleles may contribute to increased diabetes risk in subjects who harbor other genetic or environmental/lifestyle risk factors.The glycolytic enzyme glucokinase (GCK) is a glucose sensor that plays a key role in maintaining blood glucose homeostasis. In the pancreatic β-cells, GCK controls insulin secretion and biosynthesis (1). In the liver, GCK regulates glycogen synthesis and gluconeogenesis, and its activity is competitively inhibited by glucokinase regulatory protein (GCKR) (1,2).In support of these functions, rare mutations in the GCK gene have been found to be associated with maturity-onset diabetes of the young (MODY), permanent neonatal diabetes, and hyperinsulinemia of infancy (3). Moreover, a common promoter variant (−30A) (rs1799884) of GCK has been found to be associated with increased fasting plasma glucose (FPG) and lowered birth weight in general Caucasian populations (4,5). Recently, a genome-wide association (GWA) study conducted by the Diabetes Genetics Initiative identified a common intronic polymorphism at GCKR (rs780094) associated with plasma triglyceride level (6). Subsequent independent studies in Danish (7) and French (8) populations, as well as meta-analysis and fine- mapping (9) studies, confirmed that the minor alleles of rs780094 and rs1260326 (Pro446Leu), which are in strong linkage disequilibrium (LD), were associated with higher levels of triglyceride and C-reactive protein but lower fasting glucose, insulin, and/or insulin resistance.In this study, we examined the association of the GCKR rs780094 and GCK rs1799884 polymorphisms with type 2 diabetes–related quantitative traits in two independent samples of 600 adult and 986 adolescent Chinese residents in Hong Kong. Due to the intimate relationship between glucose and lipid metabolisms (10) and the functional interaction between GCKR and GCK, we also hypothesized the presence of epistasis effects between these two single nucleotide polymorphisms (SNPs) on FPG and fasting triglyceride levels.We genotyped two SNPs, rs1799884 in GCK and rs780094 in GCKR, in a total of 1,586 healthy subjects including adults and adolescents. The frequencies of the A-allele of rs1799884 were similar between our adult (0.16) and adolescent (0.19) cohorts, as well as the HapMap CHB data (0.20). Although the T-allele frequencies of rs780094 in our data (0.46 for both cohorts) were lower than in the HapMap CHB (0.60), they were similar to the frequency reported in a group of Singapore Chinese (0.46) from a meta-analysis study (9).The clinical characteristics of the adult and adolescent cohorts are summarized in ​and3)3) and remained significant after controlling for false discovery rate (P < 0.0056 for triglycerides with rs780094; P < 0.0028 for FPG with rs1799884). These findings are in agreement with reports from Caucasian populations (4,6–9,11–13), as well as a recent Japanese study (mean triglyceride levels of 1.07, 1.13, and 1.18 mmol/l, respectively, for CC, CT, and TT genotypes of rs780094, P = 0.097) (14).

TABLE 1

Clinical and metabolic characteristics of 1,586 healthy Chinese adults and adolescents

Combining the rapid MTT formazan exocytosis assay and the MC65 protection assay led to the discovery of carbazole analogs as small molecule inhibitors of Abeta oligomer-induced cytotoxicity

The discovery of small molecule inhibitors of cytotoxicity induced by amyloid-beta (Abeta) oligomers, either applied extracellularly or accumulated intraneuronally, is an important goal of drug development for Alzheimer's disease (AD), but has been limited by the lack of efficient screening methods. Here we describe our approach using two cell-based methods. The first method takes advantage of the unique ability of extracellularly applied Abeta oligomers to rapidly induce the exocytosis of formazan formed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). We employed a short protocol to quantify this toxicity, and quickly identified two novel inhibitors, code-named CP2 and A5, from two compound libraries. A second independent screen of the same libraries using our previously published MC65 protection assay, which identifies inhibitors of toxicity related to intracellular Abeta oligomers, also selected the same two leads, suggesting that both assays select for the same anti-Abeta oligomer properties displayed by these compounds. We further demonstrated that A5 attenuated the progressive aggregation of existing Abeta oligomers, reduced the level of intracellular Abeta oligomers, and prevented the Abeta oligomer-induced death of primary cortical neurons, effects similar to those demonstrated by CP2. Our results suggest that, when combined, the two methods would generate fewer false results and give a high likelihood of identifying leads that show promises in ameliorating Abeta oligomer-induced toxicities within both intraneuronal and extracellular sites. Both assays are simple, suitable for rapid screening of a large number of medicinal libraries, and amenable for automation.