Area-under-the-HbA1c-curve above the normal range and the prediction of microvascular outcomes: an analysis of data from the Diabetes Control and Complications Trial

AIMS

In the Diabetes Control and Complications Trial, mean updated HbA(1c) accounted for most of the differential risk of microvascular complications between intensive and conventional insulin therapy. We hypothesized, however, that a more precise measure of chronic hyperglycaemic exposure may be the incremental area-under-the-HbA(1c)-curve above the Diabetes Control and Complications Trial-standardized normal range for HbA(1c) (iAUC(HbA1c>norm)).

METHODS

Using the Principal Diabetes Control and Complications Trial data set, we compared the following three measures of chronic glycaemic exposure for their capacity to predict retinopathy, nephropathy and neuropathy during the Diabetes Control and Complications Trial: mean updated HbA(1c), iAUC(HbA1c>norm), and total area-under-the-HbA(1c)-curve (tAUC(HbA1c)). For each outcome, models using each of these three glycaemic measures were compared in the following three ways: hazard or odds ratio, χ(2) statistic, and Akaike information criterion.

RESULTS

The three glycaemic measures did not differ in their prediction of neuropathy. iAUC(HbA1c>norm) was modestly superior to mean updated HbA(1c) for predicting nephropathy (χ(2) P = 0.017, Akaike P = 0.032). In contrast, for predicting retinopathy, both iAUC(HbA1c>norm) (χ(2) P = 0.0005, Akaike P = 0.0005) and tAUC(HbA1c) (χ(2) P = 0.004, Akaike P = 0.004) were significantly better than mean updated HbA(1c). Varying its HbA(1c) threshold incrementally between 37 and 53 mmol/mol (5.5-7.0%), inclusive, did not improve the prediction of retinopathy by iAUC(HbA1c>threshold) beyond that of tAUC(HbA1c,) consistent with the concept of a continuous relationship between glycaemia and retinopathy, with no glycaemic threshold.

CONCLUSIONS

Both iAUC(HbA1c>norm) and tAUC(HbA1c) were superior to mean updated HbA(1c) for predicting retinopathy. Optimal assessment of chronic glycaemic exposure as a determinant of retinopathic risk may require consideration of both the degree of hyperglycaemia and its duration.

Maternal pregravid weight is the primary determinant of serum leptin and its metabolic associations in pregnancy, irrespective of gestational glucose tolerance status

CONTEXT

Several previous studies have investigated circulating levels of the adipokine leptin in relation to gestational diabetes mellitus (GDM). However, these studies have yielded markedly conflicting results, including increased, decreased, and unchanged leptin levels in women with GDM as compared with their peers.

OBJECTIVE

We sought to evaluate the metabolic determinants of serum leptin in a well-characterized cohort reflecting the full spectrum of glucose intolerance in pregnancy.

DESIGN, SETTING, AND PARTICIPANTS

Metabolic characterization, including oral glucose tolerance test (OGTT) and measurement of serum leptin, insulin, lipids, adiponectin, and C-reactive protein, was performed in 817 pregnant women. The OGTT identified 198 women with GDM, 142 with gestational impaired glucose tolerance, and 477 with normal glucose tolerance.

RESULTS

Median leptin (ng/ml) did not differ between the normal glucose tolerance (33.7), gestational impaired glucose tolerance (36.3), and GDM (36.4) groups (P = 0.085). On univariate correlation analysis, leptin was most strongly associated with prepregnancy body mass index (BMI) (r = 0.54, P < 0.0001), fasting insulin (r = 0.60, P < 0.0001), and C-reactive protein (r = 0.38, P < 0.0001) but only weakly associated with area under the glucose curve (AUC(glucose)) on the OGTT (r = 0.10, P = 0.0066). On multiple linear regression analysis, the strongest independent determinant of leptin was prepregnancy BMI (t = 11.55, P < 0.0001), whereas AUC(glucose) was not a significant predictor (t = -0.95, P = 0.34). Furthermore, although its respective associations with fasting insulin, triglycerides, and adiponectin varied across tertiles of prepregnancy BMI, leptin was not significantly associated with AUC(glucose) in any BMI tertile.

CONCLUSIONS

Pregravid BMI, rather than gestational glucose tolerance, is the primary determinant of serum leptin concentration in pregnancy.

Heterogeneous reaction of NO2 on the surface of montmorillonite particles

The studies on heterogeneous reactions over montmorillonite, which is a typical 2:1 layered aluminosilicate, will benefit to the understanding of heterogeneous reactions on clay minerals. Montmorillonite can be classified as sodium montmorillonite or calcium montmorillonite depending on the cation presented between the different layers. Using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), the heterogeneous reaction mechanism of NO2 on the surface of montmorillonite was firstly investigated. Results showed that the reaction of NO2 on the surface of sodium and calcium montmorillonite fit a first-order kinetics, and the reaction duration of calcium montmorillonite was longer than that of sodium montmorillonite under the dry condition. For either sodium or calcium montmorillonite, the uptake coefficient decreased as humidify increased.

Discordant effects on central obesity, hepatic insulin resistance, and alanine aminotransferase of low-dose metformin and thiazolidinedione combination therapy in patients with impaired glucose tolerance

Alanine aminotransferase (ALT) predicts incident type 2 diabetes (T2DM), possibly reflecting early fatty liver and hepatic insulin resistance. Thiazolidinediones and metformin can improve fatty liver and hepatic insulin resistance, respectively. In the Canadian Normoglycemia Outcome Evaluation trial, rosiglitazone/metformin (Rosi/Met, 4/1000 mg) reduced incident T2DM by 66% in subjects with impaired glucose tolerance. For insight on the hepatic effects of this therapy in relation to T2DM, we evaluated the temporal changes in waist, hepatic insulin sensitivity (1/Homeostasis Model Assessment of Insulin Resistance) and ALT in the Rosi/Met (n = 103) and placebo (n = 104) arms over median of 3.9 years. Waist did not differ between the arms. Hepatic insulin sensitivity improved in the Rosi/Met arm in year 1, but deteriorated thereafter as in the placebo arm. In contrast, Rosi/Met lowered ALT in year 1 and maintained this effect throughout the trial. Thus, low-dose Rosi/Met had no effect on central obesity, a transient effect on hepatic insulin sensitivity, and a sustained effect on ALT.

Endovascular stent-graft treatment for Stanford type A aortic dissection

OBJECTIVE

The aim of the study is to summarise our experience of endovascular stent grafting for Stanford type A aortic dissection.

DESIGN

Retrospective analysis at single centre.

METHODS

From January 2001 to January 2009, we treated 45 cases of Stanford type A aortic dissection with endovascular stent grafting. The entry tear was located at the ascending aorta in 10 cases (DeBakey type I), the aortic arch in 14 cases and the distal aortic arch or proximal descending aorta in 21 cases in which the ascending aorta was also involved by the dissection.

RESULTS

The surgical success rate was 97.8% (44/45) and 30-day mortality rate was 6.7% (3/45). Type I endoleaks occurred in 10 cases: one patient died intra-operatively, four were successfully treated with ballooning, four were sealed with aortic cuffs and one case caused by left subclavian artery (LSA) reflux was sealed with an occluder. Average follow-up time was 35.5 ± 5.4 months. Up to the most recent review or death, 32 patients had complete thrombosis and 10 had partial thrombosis inside the false lumen. Two deaths occurred after 30-days postoperatively.

CONCLUSION

Endovascular stent-graft treatment is a minimally invasive and effective method to treat Stanford type A aortic dissection.

Associations and costs of parental symptoms of psychiatric distress in a multi-diagnosis group of children with special needs

BACKGROUND

Families supporting children with complex needs are significantly more distressed and economically disadvantaged than families of children without disability and delay. What is not known is the associations and costs of parental psychiatric distress within a multi-diagnosis group of special needs children.

METHODS

In this cross-sectional survey, families were identified from the Children's Treatment Network. Families were eligible if the child was aged 0-19 years, resided in Simcoe/York, and if there were multiple family needs (n = 429).

RESULTS

Some 42% of surveyed parents exhibited symptoms (mild to severe) of psychiatric distress. The presence of these symptoms was associated with reports of poorer social support, family dysfunction, greater adverse impact of the child's situation on the family, poorer child behaviour, unfavourable parenting styles and poorer child psychosocial functioning. The severity of the child's physical dysfunction was not related to parents/guardians most knowledgeable symptoms of psychiatric distress. Total parent costs were higher and children's uses of primary care services were higher in parents with symptoms of psychiatric distress.

CONCLUSION

Parent symptoms of psychiatric distress are a significant societal concern in families with complex needs children. Children's rehabilitation efforts need to incorporate parental mental health assessment and treatment into existing programmes. This could lead to decreases in direct and indirect healthcare utilisation costs.

Rational Construction of Polymeric Nonlinear Optical Materials. Properties of Chromophore-Functionalized Polystyrenes

Processable polymeric nonlinear optical materials can be synthesized by functionalizing a glassy macromolecule with chromophores having large quadratic hyperpolarizabilities, followed by poling in an electric field. In the present case, the functionalization of polystyrene with 4- (4-nitrophenylaza)(N-ethyl)(2-hydroxyethyl))aniline, 4-(4-N,N-dimethylaminostyryl) pyridine, and N-(4-nitrophenyl)-L-prolinol is described. Particularly noteworthy is the high level of chromophore units that can be incorporated into transparent films of these materials, the high second harmonic coefficients that can be achieved (as high as d33 – 11 × 10-9 esu at 1064 nm), and the long-term temporal stability of the second harmonic generation capacity.

Applications of PZT and Related Thin Films in Piezoelectric Microsensors

Ferroelectric thin films have been deposited on polycrystalline silicon micromechanical structures to form both physical microsensors and microactuator devices. These devices which include acoustic pressure sensors, infrared detectors, micropositioners, and stepper motors are based on either the piezoelectric or pyroelectric properties of sol-gel Pb(ZrxTi1-x)O3 or PbTiO3 deposited on surface-machined microelectromechanical structures. Several materials, micromachining, process integration, and performance issues are introduced in the description of these devices.

High glucose induces dysfunction and apoptosis in endothelial cells: is the effect of high glucose persistence more important than concentration?

Oxidative stress and inflammation are involved in the pathogenesis of diabetic endothelial dysfunction. Herein we reported the biological changes induced by hyperglycemia in human umbilical vein endothelial cells (HUVECs) and the potential underlying mechanisms sought to determine whether high glucose concentration or the persistence plays a key role in the development of vascular lesions. The HUVECs were exposed to various glucose concentrations (5, 15, 30, and 60 mmol/L of D-glucose supplemented), and several oxidative stress factors, such as NO, NOS, and ROS, and inflammatory signaling markers, such as TNF-α, TNFR, RIP, TRADD, TRAF-2 and NF-κB, were analyzed at various times (24, 48, 72, and 96 h). High glucose (HG) induced a transient increase of NO within 24 h and decreased afterwards, in accord with the expression of eNOS. HG also increased ROS and TNF-α production and activated the TNF-α-mediated signal transduction, decreasing cell viability and inducing apoptosis. However, 3 HG groups had similar effects on HUVECs with the increased duration of exposure, which resulted in the amplified oxidative and inflammatory damage. Taken together, these findings suggest that the HG persistence exacerbates oxidative stress and activates the inflammatory-mediated signaling pathways, inducing endothelial dysfunction and apoptosis, regardless of the concentration of HG. Our results provide the first evidence that HG persistence is more important than concentration in the progress of diabetic endothelial dysfunction.

Quasi-steady-state and steady-state models for heat and moisture transport in textile assemblies

Heat and moisture transport plays an important role in many engineering areas. In many sweat transport systems, such as clothing assembly, the moisture concentration (or sweat) is relative small and the air concentration reaches a steady state quickly. In this paper, a quasi-steady-state multi-component and multi-phase model for heat and moisture transport in porous textile materials with phase change is proposed. An analytic form of the air concentration is obtained in terms of the mixture gas (vapour and air) concentration and temperature. The new model is described in the form of a single-component flow with an extra air resistance (permeability), involving only the vapour concentration (or pressure), temperature and water content. The existence of the classical positive solutions of the corresponding steady-state model is proved. Two types of clothing assemblies are investigated numerically. The comparisons among the experimental measurements and numerical results of the fully dynamic model, the proposed quasi-steady-state model and steady-state model are also presented. Numerical results show that the proposed quasi-steady-state model is realistic and less complicated.

Mitogenic effect contributes to increased virulence of Streptococcus suis sequence type 7 to cause streptococcal toxic shock-like syndrome

Streptococcus suis serotype 2 sequence type 7 strains emerged in 1996 and caused a streptococcal toxic shock-like syndrome in 1998 and 2005 in China. Evidence indicated that the virulence of S. suis sequence type 7 had increased, but the mechanism was unknown. The sequence type 7 strain SC84, isolated from a patient with streptococcal toxic shock-like syndrome during the Sichuan outbreak, and the sequence type 1 strain 31533, a typical highly pathogenic strain isolated from a diseased pig, were used in comparative studies. In this study we show the mechanisms underlying cytokine production differed between the two types of strains. The S. suis sequence type 7 strain SC84 possesses a stronger capacity to stimulate T cells, naive T cells and peripheral blood mononuclear cell proliferation than does S. suis sequence type 1 strain 31533. The T cell response to both strains was dependent upon the presence of antigen-presenting cells. Histo-incompatible antigen-presenting cells were sufficient to provide the accessory signals to naive T cell stimulated by the two strains, indicating that both sequence type 7 and 1 strains possess mitogens; however, the mitogenic effect was different. Therefore, we propose that the difference in the mitogenic effect of sequence type 7 strain SC84 compared with the sequence type 1 strain 31533 of S. suis may be associated with the clinical, epidemiological and microbiological difference, where the ST 7 strains have a larger mitogenic effect.

An intelligent mobile vehicle navigator based on fuzzy logic and reinforcement learning

In this paper, an alternative training approach to the EEM-based training method is presented and a fuzzy reactive navigation architecture is described. The new training method is 270 times faster in learning speed; and is only 4% of the learning cost of the EEM method. It also has very reliable convergence of learning; very high number of learned rules (98.8%); and high adaptability. Using the rule base learned from the new method, the proposed fuzzy reactive navigator fuses the obstacle avoidance behaviour and goal seeking behaviour to determine its control actions, where adaptability is achieved with the aid of an environment evaluator. A comparison of this navigator using the rule bases obtained from the new training method and the EEM method, shows that the new navigator guarantees a solution and its solution is more acceptable.

Quantitation of SU11248, an oral multi-target tyrosine kinase inhibitor, and its metabolite in monkey tissues by liquid chromatograph with tandem mass spectrometry following semi-automated liquid–liquid extraction

SU11248 is a potent inhibitor of PDGFR, VEGFR, KIT, and Flt3, and is currently under Phase I clinical evaluation as an anticancer drug. A sensitive and specific analytical method for the quantitation of SU11248 and its metabolite in several monkey tissues (liver, kidney, brain and white fat) using LC-MS-MS following semi-automated liquid-liquid extraction (LLE) was developed and validated. Amounts of 50 mg of tissue were homogenized using an ultrasonic processor. After addition of the stable labelled internal standard (IS) and ammonium hydroxide (0.3%), samples were extracted with 2.5 ml of tert-butyl methyl ether. Following centrifugation, aliquots of 1.8 ml of the organic phase were transferred into a 96-well plate. The Packard Multiprobe II robotic liquid handler was used to perform all steps mentioned above. The organic phase was dried and the residue was reconstituted with 800 microl of 15 mM ammonium formate buffer solution (pH 3.25) using a Tomtec Quadra 96 workstation. Aliquots of 10 microl of the resulting solution were injected into the LC-MS-MS system. A Symmetry Shield C8 column (50 mm x 2.1 mm, 3.5 microm) was used to perform the chromatographic analysis. The mobile phase was 15 mM ammonium formate buffer solution (pH 3.25)-acetonitrile (74:26 (v/v)) with a flow-rate of 0.35 ml/min. Retention times of the metabolite and SU11248 were about 2.5 and 3.5 min, respectively. Total cycle time was 5 min. MS detection used the Applied Biosystems-MDS Sciex API 3000 with TurbolonSpray interface and multiple reaction monitoring (MRM) operated in positive ion mode. The method was validated for both compounds over the calibration range of about 2 and 2000 ng/g. The suitability and robustness of the method for in vivo samples were confirmed by analysis of monkey tissues from animals dosed with SU11248.

[Preparation and analysis of pure type II collagen from porcine articular cartilage]

This investigation was aimed at the preparation of pure type II collagen from porcine articular cartilage and the feasible method for producing type II collagen in bulk. After dispersal of the porcine articular cartilage, the proteoglycans were extracted by guanidinium hydrochloride and dissolved by pepsin in acid solvent. The contaminants including denatured and degraded protein and other collagen was removed via the repeated procedure of purification. For obtaining the purer type II collagen, the chromatography with sepharose H. P. Column was also used. The purity of the sample was compared with the type II collagen produced by Sigma Company. Both type II collagens were characterized by SDS-PAGE electrophoresis, amino acid analysis and maximal violet chromatography, and all of the results accorded with the standard photograph in the references. The purity of the sample was higher than that of the product of Sigma Company. This prepared collagen of type II is a product of high purity. The raw materials are the common porcine articular cartilage, which is rich in resource and low in cost. Therefore, it is suitable to produce type II collagen in batches.

Room-temperature ionic liquids: a novel versatile lubricant

Alkylimidazolium tetrafluoroborates are promising versatile lubricants for the contact of steel/steel, steel/aluminium, steel/copper, steel/SiO2, Si3N4/SiO2, steel/Si(100), steel/sialon ceramics and Si3N4/sialon ceramics; they show excellent friction reduction, antiwear performance and high load-carrying capacity.

[The transferability of acetochlor and butachlor in soil]

The transferability of acetochlor and butachlor in soil was studied by soil thin layer chromatography. Acetochlor and butachlor were dropped on the glass plate and spreaded soil on the glass plate was collected per 2 cm, then acetochlor and butachlor were analyzed quantitatively by HPlC. When river water was as the spread solution, Rf(relative flow) of acetochlor and butachlor in the Haidian loam were 0.116 and 0.031 respectively, Rf of acetochlor and butachlor in the Baiyangdian sandy loam were 0.147 and 0.032 respectively. When 30 mg.L-1 dodecylbenzene sulfonic acid sodium salt solution was as the spread solution, Rf of acetochlor and butachlor in the Haidian loam were 0.159 and 0.034 respectively. Acetochlor's transferability was weak and the gradation of its transferability was II grade, while butachlor's was more weak and the gradation was I grade. Anionic surfactant solution can promote pesticides to transfer. Cationic surfactant solution can impede pesticides to transfer.

Prevalence of iron transport gene on pathogenicity-associated island of uropathogenic Escherichia coli in E. coli O157:H7 containing Shiga toxin gene

Uropathogenc Escherichia coli (UPEC) CFT073 has a pathogenicity-associated island (PAI(CFT073)), which causes pyelonephritis and cystitis. Using PCR method, we found the prrA gene of PAI(CFT073) in E. coli O157:H7 EDL933. Further detailed PCR screening of 38 open reading frames, the right and left junction sequences of PAI(CFT073), revealed that it is the prrA-modD-yc73-fepC gene cluster but not the PAI(CFT073) present in E. coli O157:H7 EDL933. A rapid preliminary analysis suggested that the prrA-modD-yc73-fepC gene cluster of the PAI(CFT073), is present in 43 strains of E. coli O157:H7 containing Shiga toxin (Stx) gene but absent in 19 strains of E. coli O157:H7 without Stx gene. A strict co-occurrence of the prrA-modD-yc73-fepC gene cluster and Stx genes was observed, regardless of their origin. The prrA-modD-yc73-fepC gene cluster encode proteins probably involved in iron uptake system, which strongly suggests the importance of iron metabolism in the Stx-mediated virulence. In addition, the prrA-modD-yc73-fepC gene cluster may be used as a diagnostic marker to distinguish E. coli O157:H7 strains containing Stx gene from that without Stx gene, and possibly to quickly detect other pathogenic gram-negative bacteria containing the Stx gene.

Dynamics and mechanism of ultraviolet photolysis of atrazine on soil surface

The photolysis of atrazine in the soil surface under UV light and the factors affecting this has been studied. A rate constant of 0.09-0.17 min-1, photolytic depth of 0.1-0.3 mm and half-life of 4-8 min were determined. The results show that soil granularity, pH, humidity, organic content, humic acid and surface-active agents could affect the photolysis of atrazine in soil. GC-MS showed three photolytic products: 1-sec-butyl-4,4-diethyl-1-tetrazene, N2,N4-diethyl-6-methyl-1,3,5-triazine-2,4-diamine and 6-chloro-N2-propyl-1,3,5-triazine-2,4-diamine. The mechanism of the photolytic process is discussed.

Oral HCFU for prevention of hepatic metastasis in an experimental colorectal carcinoma

BACKGROUND

An animal experimental study was performed to clarify the preventive effect of oral HCFU (1-hexylcarbamoyl-5-fluorouracil) on hepatic metastasis.

MATERIALS AND METHODS

A total of 180 BALB/C mice received intraportal injection of Colon26 cancer cells followed by oral daily administration of HCFU to 5 groups divided according to the dose of HCFU, ranging from 0 (controls) to 7.5 mg/Kg for 21 days. These groups were independently assigned to 3 sets to investigate survival rates and degree of hepatic metastasis.

RESULTS

Mean survivals in the treated groups were statistically longer than the controls except the 7.5 mg/Kg group. HCFU 7.5 and 5 mg/Kg groups showed the minimum liver weight on the 12th and 16th day, respectively these were significantly smaller than those of controls (p < 0.0001 in both).

CONCLUSION

It is considered that oral HCFU could effectively suppress hepatic metastasis of the colon26 cancer cells and prolong the life of animals. This finding suggests the promising clinical application of oral HCFU for colorectal cancer after curative resection.

[Multimedia environmental behavior of herbicide atrazine]

In the paper, taking the Baiyangdiang Lake area as a study field, on the basis of soil characterization, environmental monitoring, and studies of adsorption, biodegradation, hydrolysis and photolysis, the atrazine concentrations in soil, groundwater and corn plant during 30 years were predicted by multimedia environmental fugacity model.

Expression of extracellular calcium-sensing receptor in human osteoblastic MG-63 cell line

We have previously shown the expression of the extracellular calcium (Ca2+o)-sensing receptor (CaR) in osteoblast-like cell lines, and others have documented its expression in sections of murine, bovine, and rat bone. The existence of the CaR in osteoblasts remains controversial, however, since some studies have failed to document its expression in the same osteoblast-like cell lines. The goals of the present study were twofold. 1) We sought to determine whether the CaR is expressed in the human osteoblast-like cell line, MG-63, which has recently been reported by others not to express this receptor. 2) We investigated whether the CaR, if present in MG-63 cells, is functionally active, since most previous studies have not proven the role of the CaR in mediating known actions of Ca2+o on osteoblast-like cells. We used immunocytochemistry and Western blotting with the specific, affinity-purified anti-CaR antiserum 4637 as well as Northern blot analysis and RT-PCR using a riboprobe and PCR primers specific for the human CaR, respectively, to show readily detectable CaR protein and mRNA expression in MG-63 cells. Finally, we employed the patch-clamp technique to show that an elevation in Ca2+o as well as the specific, allosteric CaR activator NPS R-467 (0.5 microM), but not its less active stereoisomer NPS S-467 (0.5 microM), activate an outward K+ channel in MG-63 cells, strongly suggesting that the CaR in MG-63 cells is not only expressed but is functionally active.

Soluble recombinant endostatin purified from Escherichia coli: antiangiogenic activity and antitumor effect

Endostatin is a potent and specific antiangiogenic protein capable of inhibiting the growth of murine and xenotransplanted human tumors. Thus far, however, recombinant endostatin prepared from Escherichia coli is insoluble after purification and therefore inappropriate for clinical settings. A soluble form of endostatin is available from a yeast system with relatively low yield and high cost, which has made it difficult to produce endostatin in quantities sufficient for extensive clinical evaluation. In this study, we developed a protocol to generate soluble recombinant murine endostatin from E. coli at a yield of 150 mg/liter-culture and 99% purity. The in vivo antiangiogenic and antitumor activities of the soluble recombinant endostatin are equally as potent as those of the previously published insoluble form. A similar protocol may be used to produce soluble human endostatin.

High-pathogenicity island of Yersinia spp. in Escherichia coli strains isolated from diarrhea patients in China

The high-pathogenicity island (HPI) of Yersinia has been observed in 93% of 60 enteroadhesive Escherichia coli strains and 80% of E. coli strains isolated from blood samples. In the present study we investigated 671 fecal samples from patients with diarrhea in Shandong Province, China, and isolated HPI-harboring E. coli from 6. 26% of the samples. The isolation rates for patients with diarrhea in three age groups, 10 to 20, 30 to 40, and 50 to 60 years, were 6. 70, 12.35, and 10.81%, respectively. Therefore, HPI-harboring E. coli is the third most frequently isolated enteric pathogen from patients with diarrhea. Vomiting and abdominal pain were recorded for 33.33 and 66.67% of the patients, respectively. Stools with blood were observed for 9.52% of the patients. Twenty-four of 42 (57%) patients experienced a temperature over 37.4 degrees C. These observations indicate that HPI-harboring E. coli is one of the major causes of diarrheal disease in China and that the clinical symptoms caused by HPI-harboring E. coli differ from those caused by enteroadhesive E. coli.

Galpha(i2) but not Galpha(i3) is required for muscarinic inhibition of contractility and calcium currents in adult cardiomyocytes

Parasympathetic stimulation of the heart acts through M(2)-muscarinic acetylcholine receptors to regulate ion channel activity and subsequent inotropic status. Although muscarinic signal transduction is mediated via pertussis toxin-sensitive G proteins Galpha(i/o), the specific signal transduction requirements of Galpha(i2) and Galpha(i3) in mediating muscarinic regulated L-type calcium currents (I(Ca, L)), intracellular calcium, and cell contractility remain to be determined. Adult ventricular myocytes were isolated from Galpha(i2)-null mice, Galpha(i3)-null mice, and their wild-type littermates. Cell shortening, intracellular calcium levels, and I(Ca, L) were all measured in response to isoproterenol, a beta-adrenergic receptor agonist, and carbachol, a cholinergic receptor agonist. With isoproterenol stimulation, myocytes from all groups demonstrated a marked increase in calcium currents, correlating with augmented intracellular calcium transient amplitude and cell shortening. Carbachol significantly attenuated the isoproterenol response in wild-type and Galpha(i3)-null cells but had no effect in Galpha(i2)-null cells. This study demonstrates that Galpha(i2), but not Galpha(i3), is required for muscarinic inhibition of the beta-adrenergic response in adult murine ventricular myocytes.

Development of an affordable diaphragmatic pump for cardiopulmonary bypass: an in vivo evaluation

A new diaphragmatic pump (L-Y pump) and its drive unit were developed in our institute. The pump has a priming volume of 80 ml. The pump housing is 72 mm in diameter and 42 mm in height. Its total weight is 139 g. To assess and confirm the function and controllability of this pump, comparative studies of cardiopulmonary bypass (CPB) with L-Y pump (group A) and conventional roller pump (Group B) were performed using dogs. Both pumps provided pump flow of 90 to 100 ml/kg/min. The hemodynamics of both groups were stable and within the normal range. No leakage or thrombus formation was observed in the L-Y pump. All biochemistry data showed no significant differences between the 2 groups. This data demonstrated low plasma-free hemoglobin levels in the L-Y pump group; after 120 min of CPB, mean plasma free hemoglobin levels were 48.7 +/- 8.6 mg/dl in the roller pump group and 21.4 +/- 7.1 mg/dl in the L-Y pump group, and minimal hemolysis was indicated. In conclusion, this L-Y pump and its controller system might be useful for CPB in terms of its low hemolysis and good pump quality. This pump demonstrated easy manipulation, good controllability, and provided a sufficient pulsatile flow. This pump is suitable not only for CPB, but also as a long-term circulatory support system.

Defective extracellular calcium (Ca(o))-sensing receptor (CaR)-mediated stimulation of a Ca(2+)-activated potassium channel in glioblastoma cells transfected with a dominant negative CaR

Glioblastoma cells exhibit several forms of sensitivity to extracellular calcium (Ca(o)) that might be conferred by the Ca(o)-sensing receptor (CaR) that is intimately involved in the maintenance of Ca(o) homeostasis by various cell types. This receptor is expressed in human glioblastoma cell line, U87, and here we show that CaR activators stimulate a Ca(2+)-activated potassium (K(+)) channel (CAKC) with a conductance of 140 pS. The responses to CaR activators, however, were blunted in U87 cells transfected with a CaR bearing an inactivating mutation (R185Q) that has previously been shown to exert a dominant negative (DN) action on the wild type receptor. Raising Ca(o) from 0.75 to 2.0 mM or addition of a polycationic CaR agonist, each activated CAKC in nontransfected wild type and empty vector-transfected U87 cells, while they had little or no effect on channel activity in cells expressing the DN CaR (DN-CaR cells). In nontransfected wild type and empty vector-transfected cells, the specific 'calcimimetic' CaR activator, NPS R-467, stimulated the channel, while its less active stereoisomer, NPS S-467, did not. In DN-CaR cells, in contrast, NPS R-467, had no effect on channel activity, suggesting defective coupling of the CaR to this ion channel. CaR-mediated stimulation of these K(+) channels could lead to membrane repolarization and related changes in cellular function under normal conditions. Since the R185Q mutation in the CaR produces a more severe phenotype in humans than most inactivating mutations of this receptor, some of its clinical consequences could potentially result from abnormal CaR-dependent channel functioning.

[The research and manufacture of the pneumatic left ventricular assist pump]

The manufacturing methods and testing results of the pneumatic left ventricular assist pump(L-Y pump) are introduced in this paper. The results demonstrate that L-Y pump is reliable, biocompatible and in keeping with the clinical requirements.

Design of experiment and data analysis by JMP (SAS institute) in analytical method validation

Validation of an analytical method through a series of experiments demonstrates that the method is suitable for its intended purpose. Due to multi-parameters to be examined and a large number of experiments involved in validation, it is important to design the experiments scientifically so that appropriate validation parameters can be examined simultaneously to provide a sound, overall knowledge of the capabilities of the analytical method. A statistical method through design of experiment (DOE) was applied to the validation of a HPLC analytical method for the quantitation of a small molecule in drug product in terms of intermediate precision and robustness study. The data were analyzed in JMP (SAS institute) software using analyses of variance method. Confidence intervals for outcomes and control limits for individual parameters were determined. It was demonstrated that the experimental design and statistical analysis used in this study provided an efficient and systematic approach to evaluating intermediate precision and robustness for a HPLC analytical method for small molecule quantitation.

A high-resolution (13)C 3D CSA-CSA-CSA correlation experiment by means of magic angle turning

It is shown in this paper that a previously reported 90 degrees sample flipping (13)C 2D CSA-CSA correlation experiment may be carried out alternatively by employing constant slow sample rotation about the magic angle axis and by synchronizing the read pulse to 13 of the rotor cycle. A high-resolution 3D CSA-CSA-CSA correlation experiment based on the magic angle turning technique is reported in which the conventional 90 degrees 2D CSA-CSA powder pattern for each carbon in a system containing a number of inequivalent carbons may be separated according to the isotropic chemical shift value. The technique is demonstrated on 1,2,3-trimethoxybenzene in which all of the overlapping powder patterns that cannot be segregated by the 2D CSA-CSA experiment are resolved successfully by the 3D CSA-CSA-CSA experiment, including even the two methoxy groups (M(1) and M(3)) whose isotropic shifts, confirmed by high-speed MAS, are separated by only 1 ppm. A difference of 4 ppm in the principal value component (delta(33)) between M(1) and M(3) is readily obtained.

Generation of a polymorphic marker linked to thymoma susceptibility gene of rat 1 by genetically-directed representational difference analysis

BUF/Mna (BUF) is a rat strain susceptible to spontaneous development of thymomas. We have previously shown that the thymoma susceptibility is controlled principally by a dominant susceptibility gene located on chromosome 7, thymoma susceptibility gene of rat 1 (Tsr1). To generate genetic markers tightly linked to Tsr1, we performed genetically directed representational difference analysis (GDRDA) with three combinations of the tester and driver DNAs. From 124 ¿ACI/NMs x (BUF x ACI/NMs) F1¿ backcross rats, 12 rats with the ACI/BUF genotype in the Tsr1 region (A/B rats) and 13 rats with the ACI/ACI genotype in the region (A/A rats) were selected, and their DNAs were pooled, respectively. Three kinds of tester DNAs, i) inbred BUF, ii) (BUF x ACI)F1, and iii) the pool from the A/B rats, were subtracted by the driver DNA prepared from the pool of the A/A rats. The three combinations yielded one, two, and one polymorphic marker(s), respectively. One marker, D7Ncc28, was isolated commonly by the three combinations of subtraction, and another marker, D11Ncc12 was isolated only by the second combination. Linkage analysis demonstrated that D7Ncc28 was located in the 8.3 cM region where Tsr1 has been mapped. The three combinations of subtraction were shown to be almost equally capable of isolating polymorphic markers in a specific chromosomal region.

Enhanced expression of extracellular calcium sensing receptor in monocyte-differentiated versus undifferentiated HL-60 cells: potential role in regulation of a nonselective cation channel

Human promyelocytic leukemia cells (HL-60) have been used widely as a model for studying the differentiation of hematopoietic progenitor cells in vitro. After treatment with phorbol-12-myristate-13-acetate (PMA) or 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], HL-60 cells differentiate into cells with the phenotype of monocytes/macrophages. We previously showed that peripheral blood monocytes and the murine J774 monocytic cell line express the CaR, and myeloid progenitors in the bone marrow and myeloid cells in peripheral blood other than monocytes express lower levels of the CaR. Therefore, we investigated whether undifferentiated HL-60 cells express a functional G protein-coupled, extracellular calcium (Ca(2+)(o))-sensing receptor (CaR) and if the expression of the CaR increases as these cells differentiate along the monocytic lineage. The use of reverse transcription-polymerase chain reaction (RT-PCR) with CaR-specific primers, followed by sequencing of the amplified products, identified an authentic CaR transcript in undifferentiated HL-60 cells. Both immunocytochemistry and Western blot analysis using a CaR-specific antiserum detected low levels of CaR protein expression in undifferentiated HL-60 cells. The levels of CaR protein increased considerably following treatment of the cells with PMA (50 nM) or 1,25(OH)(2)D(3) (100 nM) for 5 days. Northern analysis using a CaR-specific riboprobe identified CaR transcripts in undifferentiated HL-60 cells, but CaR mRNA levels did not change appreciably after treatment with either agent, suggesting that upregulation of CaR protein occurs at a translational level. PMA-treated HL-60 cells expressed a nonselective cation channel (NCC), and the calcimimetic CaR activator, NPS R-467, but not its less active stereoisomer, NPS S-467, as well as the polycationic CaR agonist, neomycin, activated this NCC, demonstrating that the CaR expressed in these cells is functionally active. Therefore, HL-60 cells exhibit an increase in CaR protein expression, occurring at a translational level during their differentiation into cells with a monocyte/macrophage phenotype in response to treatment with PMA or 1, 25(OH)(2)D(3), which is functionally linked to activation of a nonselective cation channel.

Spin-locking mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning

The spin-locking mechanism of the spin I = 3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrödinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-locking signals. The spin-locking for a spin I = 3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences.