Design and Analysis of Porous Elastomeric Polymer Based on Electro-Mechanical Coupling Characteristics for Flexible Pressure Sensor

Elastomeric polymers have gained significant attention in the field of flexible electronics. The investigation of the electro-mechanical response relationship between polymer structure and flexible electronics is in increasing demand. This study investigated the factors that affect the performance of flexible capacitive pressure sensors using the finite element method (FEM). The sensor employed a porous elastomeric polymer as the dielectric layer. The results indicate that the sensor's performance was influenced by both the structural and material characteristics of the porous elastomeric polymer. In terms of structural characteristics, porosity was the primary factor influencing the performance of sensors. At a porosity of 76%, the sensitivity was 42 times higher than at a porosity of 1%. In terms of material properties, Young's modulus played a crucial role in influencing the performance of the sensors. In particular, the influence on the sensor became more pronounced when Young's modulus was less than 1 MPa. Furthermore, porous polydimethylsiloxane (PDMS) with porosities of 34%, 47%, 67%, and 72% was fabricated as the dielectric layer for the sensor using the thermal expansion microsphere method, followed by sensing capability testing. The results indicate that the sensor's sensitivity was noticeably influenced within the high porosity range, aligning with the trend observed in the simulation.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Untargeted Metabolomic Profiling of the Correlation Between Prognosis Differences and PD-1 Expression in Sepsis: A Preliminary Study

Objectives: The mortality rate of sepsis remains very high. Metabolomic techniques are playing increasingly important roles in diagnosis and treatment in critical care medicine. The purpose of our research was to use untargeted metabolomics to identify and analyze the common differential metabolites among patients with sepsis with differences in their 7-day prognosis and blood PD-1 expression and analyze their correlations with environmental factors.

Methods: Plasma samples from 18 patients with sepsis were analyzed by untargeted LC-MS metabolomics. Based on the 7-day prognoses of the sepsis patients or their levels of PD-1 expression on the surface of CD4+ T cells in the blood, we divided the patients into two groups. We used a combination of multidimensional and monodimensional methods for statistical analysis. At the same time, the Spearman correlation analysis method was used to analyze the correlation between the differential metabolites and inflammatory factors.

Results: In the positive and negative ionization modes, 16 and 8 differential metabolites were obtained between the 7-day death and survival groups, respectively; 5 and 8 differential metabolites were obtained between the high PD-1 and low PD-1 groups, respectively. We identified three common differential metabolites from the two groups, namely, PC (P-18:0/14:0), 2-ethyl-2-hydroxybutyric acid and glyceraldehyde. Then, we analyzed the correlations between environmental factors and the common differences in metabolites. Among the identified metabolites, 2-ethyl-2-hydroxybutyric acid was positively correlated with the levels of IL-2 and lactic acid (Lac) (P < 0.01 and P < 0.05, respectively).

Conclusions: These three metabolites were identified as common differential metabolites between the 7-day prognosis groups and the PD-1 expression level groups of sepsis patients. They may be involved in regulating the expression of PD-1 on the surface of CD4+ T cells through the action of related environmental factors such as IL-2 or Lac, which in turn affects the 7-day prognosis of sepsis patients.

A combination of three probiotic strains for treatment of acute diarrhoea in hospitalised children: an open label, randomised controlled trial

Acute diarrhoea continues to be a leading cause of morbidity, hospitalisation, and mortality worldwide, and probiotics have been proposed as a complementary therapy in the treatment of acute diarrhoea. The goal of this study is to assess the efficacy and safety of three combined probiotic strains, Bifidobacterium lactis Bi-07, Lactobacillus rhamnosus HN001, and Lactobacillus acidophilus NCFM, as an adjunct to rehydration therapy in treatment of acute watery diarrhoea in hospitalised children. Eligible diarrheal children were randomised into intervention group (IG, n=96, conventional treatment for diarrhoea in combination with probiotics) and control group (CG, n=98, conventional treatment for diarrhoea without probiotics). The primary assessments of this study were duration of diarrhoea and hospital stay and improvement in diarrhoea symptoms. Significantly more children in the IG showed improvements in diarrhoea (defined as a decrease of stool frequency to no more than four times per day and an improved stool consistency within 24-48 h after the treatment) than those in the CG (96.9 vs 79.6%, P<0.05). Children supplemented with the mixed strains had a 22.5 h shorter (121.4±13.7 h vs 143.9±19.8 h) mean duration of diarrhoea and 1.2 d shorter hospital stays (5.1±1.2 d vs 6.3±1.4 d) than children only receiving the rehydration therapy (P<0.05). The prevalence of constipation of children in the IG (3.1%) was markedly lower (P<0.05) than that of children in the CG (13.3%) after treatment. In conclusion, the mixture of three probiotic strains given to children aged 1-3 years resulted in shorter durations of diarrhoea and hospitalisation and a higher percentage of improved children.

Global transcriptome analysis to identify critical genes involved in the pathology of osteoarthritis

Objectives

The aim of this study was to identify key pathological genes in osteoarthritis (OA).

Methods

We searched and downloaded mRNA expression data from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) of joint synovial tissues from OA and normal individuals. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analyses were used to assess the function of identified DEGs. The protein-protein interaction (PPI) network and transcriptional factors (TFs) regulatory network were used to further explore the function of identified DEGs. The quantitative real-time polymerase chain reaction (qRT-PCR) was applied to validate the result of bioinformatics analysis. Electronic validation was performed to verify the expression of selected DEGs. The diagnosis value of identified DEGs was accessed by receiver operating characteristic (ROC) analysis.

Results

A total of 1085 DEGs were identified. KEGG pathway analysis displayed that Wnt was a significantly enriched signalling pathway. Some hub genes with high interactions such as USP46, CPVL, FKBP5, FOSL2, GADD45B, PTGS1, and ZNF423 were identified in the PPI and TFs network. The results of qRT-PCR showed that GADD45B, ADAMTS1, and TFAM were down-regulated in joint synovial tissues of OA, which was consistent with the bioinformatics analysis. The expression levels of USP46, CPVL, FOSL2, and PTGS1 in electronic validation were compatible with the bio-informatics result. CPVL and TFAM had a potential diagnostic value for OA based on the ROC analysis.

Conclusion

The deregulated genes including USP46, CPVL, FKBP5, FOSL2, GADD45B, PTGS1, ZNF423, ADAMTS1, and TFAM might be involved in the pathology of OA.

Cite this article: X. Zhang, Y. Bu, B. Zhu, Q. Zhao, Z. Lv, B. Li, J. Liu. Global transcriptome analysis to identify critical genes involved in the pathology of osteoarthritis. Bone Joint Res 2018;7:298–307. DOI: 10.1302/2046-3758.74.BJR-2017-0245.R1.

Leaching of Conductive Species: Implications to Measurements of Electrical Resistivity

Electrical tests have been used to characterize the microstructure of porous materials, the measured electrical response being determined by the contribution of the microstructure (porosity and tortuosity) and the electrical properties of the solution (conductivity of the pore solution) inside the pores of the material. This study has shown how differences in concentration between the pore solution (i.e., the solution in the pores) and the storage solution surrounding the test specimen leads to significant transport (leaching) of the conductive ionic species between the pore solution and the storage solution. Leaching influences the resistivity of the pore solution, thereby influencing electrical measurements on the bulk material from either a surface or uniaxial bulk resistance test. This paper has three main conclusions: 1.) Leaching of conductive species does occur with concentration gradients and that a diffusion based approach can be used to estimate the time scale associated with this change. 2.) Leaching of ions in the pore solution can influence resistivity measurements, and the ratio of surface to uniaxial resistivity can be used as a method to assess the presence of leaching and 3.) An estimation of the magnitude of leaching for standardized tests of cementitious materials.

Silencing NFBD1/MDC1 enhances the radiosensitivity of human nasopharyngeal cancer CNE1 cells and results in tumor growth inhibition

NFBD1 functions in cell cycle checkpoint activation and DNA repair following ionizing radiation (IR). In this study, we defined the NFBD1 as a tractable molecular target to radiosensitize nasopharyngeal carcinoma (NPC) cells. Silencing NFBD1 using lentivirus-mediated shRNA-sensitized NPC cells to radiation in a dose-dependent manner, increasing apoptotic cell death, decreasing clonogenic survival and delaying DNA damage repair. Furthermore, downregulation of NFBD1 inhibited the amplification of the IR-induced DNA damage signal, and failed to accumulate and retain DNA damage-response proteins at the DNA damage sites, which leaded to defective checkpoint activation following DNA damage. We also implicated the involvement of NFBD1 in IR-induced Rad51 and DNA-dependent protein kinase catalytic subunit foci formation. Xenografts models in nude mice showed that silencing NFBD1 significantly enhanced the antitumor activity of IR, leading to tumor growth inhibition of the combination therapy. Our studies suggested that a combination of gene therapy and radiation therapy may be an effective strategy for human NPC treatment.

Lower serum fibroblast activation protein shows promise in the exclusion of clinically significant liver fibrosis due to non-alcoholic fatty liver disease in diabetes and obesity

Non-alcoholic fatty liver disease (NAFLD) is common in diabetes and obesity but few have clinically significant liver fibrosis. Improved risk-assessment is needed as the commonly used clinical-risk algorithm, the NAFLD fibrosis score (NFS), is often inconclusive.

AIMS

To determine whether circulating fibroblast activation protein (cFAP), which is elevated in cirrhosis, has value in excluding significant fibrosis, particularly combined with NFS.

METHODS

cFAP was measured in 106 with type 2 diabetes who had transient elastography (Cohort 1) and 146 with morbid obesity who had liver biopsy (Cohort 2).

RESULTS

In Cohort 1, cFAP (per SD) independently associated with median liver stiffness (LSM) ≥ 10.3 kPa with OR of 2.0 (95% CI 1.2-3.4), p=0.006. There was 0.12 OR (95% CI 0.03-0.61) of LSM ≥ 10.3 kPa for those in the lowest compared with the highest FAP tertile (p=0.010). FAP levels below 730 pmol AMC/min/mL had 95% NPV for LSM ≥ 10.3 kPa and reclassified 41% of 64 subjects from NFS 'indeterminate-risk' to 'low-risk'. In Cohort 2, cFAP (per SD), associated with 1.7 fold (95% CI 1.1-2.8) increased odds of significant fibrosis (F ≥ 2), p=0.021, and low cFAP reclassified 49% of 73 subjects from 'indeterminate-risk' to 'low-risk'.

CONCLUSIONS

Lower cFAP, when combined with NFS, may have clinical utility in excluding significant fibrosis in diabetes and obesity.

LPCVD of InN on GaAs(110) Using HN3 and TMIn: Comparison with Si(100) Results

Low-pressure chemical vapor deposition (LPCVD) of InN and laser-assisted LPCVD on GaAs(110) and Si(100) using HN3 and trimethyl indium (TMIn) has been studied with XPS, UPS and SEM. Without 308-nm excimer laser irradiation, InN film was built on the GaAs but not on Si surface under the present low-pressure conditions. When the photon beam was introduced, InN films with In:N atomic ratio of 1.0±0.1 and a thickness of more than 20 Å (the limit of the electron escaping depth for the In3d X-ray photoelectrons) were formed on Si(100) surface. In both cases, the formation of surface nitrides at the initial film growth processes was clearly indicated in the XPS spectra. The He(II) UP spectra taken from InN films on GaAs and Si are nearly identical and agree well with the result of a pseudo-potential calculation for the InN valence band. The corresponding SEM pictures showed smooth InN films on GaAs(110), while grains with diameter of ∼100 nm were observed for InN on Si(100).

Biochemical mechanisms of action of Hypericum LI 160 in glial and neuronal cells: inhibition of neurotransmitter uptake and stimulation of extracellular signal regulated protein kinase

We have investigated biochemical mechanisms that may underlie the antidepressant effects of Hypericum LI 160. We found that LI 160 inhibits uptake of serotonin and norepinephrine in cultures of rat cortical astrocytes. Observed differences in the kinetic parameters Km and Vmax as well as in the recovery of uptake after removal of Hypericum indicates that LI 160 does not affect serotonin and norepinephrine transport in the same manner. This suggests that multiple components of the extract can mediate inhibition of these neurotransmitter transporters. Hypericum LI 160 also inhibits serotonin uptake in neuronal cultures from serotonergic-rich raphe nuclei; concentration-response studies indicate LI 160 is 25 times more potent in terms of inhibition of serotonin uptake in neurons than in astrocytes. In addition, Hypericum LI 160 inhibits norepinephrine uptake in SK-N-SH cells, a human neuroblastoma cell line enriched in norepinephrine transporters. A chemical constituent of LI 160, hyperforin, is about 10 to 20 times more potent than LI 160 in inhibiting neurotransmitter uptake in astrocytes and neuronal cells; this finding is consistent with the observation that hyperforin comprises 5% of LI 160 extracts. As several weeks are needed to achieve a clinical response with antidepressants, we have also investigated whether Hypericum LI 160 affects biochemical mechanisms that underlie long-term changes such as gene expression. We found that LI 160 stimulates a sustained activation of extracellular signal regulated protein kinase (ERK), a key component of a signal transduction pathway involved in gene expression. Taken together, our findings suggest that Hypericum LI 160 can affect rapidly-acting as well as slower-developing, long-term biochemical mechanisms related to depressive disorders.

The generation of Th memory in neonates versus adults: prolonged primary Th2 effector function and impaired development of Th1 memory effector function in murine neonates

Immunization during the neonatal period often results in Th2-biased secondary responses. To understand the regulation of this phenomenon, we have examined all phases of Th development, from the generation of primary effectors to the duration of the primary effector stage to the production of memory effector function. First, we had previously reported that although primary responses in the neonatal lymph nodes are mature, mixed Th1/Th2-like, primary responses in the spleens of the same animals are exclusively Th2-like. To determine whether Th2-dominant secondary responses are due to the Th2-polarized primary function in the spleen, neonates were splenectomized before immunization. Even in the absence of primary neonatal splenic responses, the secondary responses of neonates were Th2 dominant. Thus, the overwhelmingly Th2 primary responses in the neonatal spleen are not required to generate Th2-dominant memory in the lymph nodes. Second, we have compared the kinetics of the primary response phase in neonates and adults. In adults, Ag-specific Th2 function disappeared rapidly from both the lymph nodes and spleen. In contrast, primary Th2 function persisted out to 5 wk in both neonatal organs. Third, the generation of Th memory responses was examined in animals initially immunized as neonates and in adults. These experiments demonstrated that neonates are selectively impaired in the development of Th1 memory effector function. Together, these results indicate that neonates are biased to Th2 function at all phases of an immune response.

[The effect of methylenum coeruleum in laparoscope cholecystectomy]

OBJECTIVES

To help the operator correctly judge in operation the cystic gall duct and choledoch, and eliminate the operation wound.

METHODS

To divide laparoscope cholecystectomy patients with the same weight at the same period into two groups: development group (589 cases) using methylenum coeruleum and conducting cholecysto-puncture visualization during the operation in which colors of cholecyst, cystic gall duct and choledoch turn blue; comparative group (553 cases) using regular laparoscope cholecystectomy.

RESULTS

The two groups differed remarkably in operation time, complication, and transferring rate (P < 0.01).

CONCLUSIONS

Methylenum coeruleum development technology in operation is a kind of visualization to help the operator judge in operation Calot triangular anatomy construction correctly, reduce the operation time obviously, and increase the rate of success.

Exclusive Th2 primary effector function in spleens but mixed Th1/Th2 function in lymph nodes of murine neonates

Recent studies have shown that neonatal mice are competent to develop mature, Ag-specific Th1 function in situ. However, under many conditions, Th2 responses dominate in the neonate, while Th1 responses are more prevalent in adults. To compare further the immune responses of neonates and adults, we used the enzyme-linked immunospot method to measure the frequencies of primary Th1/Th2 effectors generated in situ in the spleens and lymph nodes. As assessed by the detection of IFN-gamma- or IL-4-producing cells, adults developed mixed Th1/Th2 responses in both organs. Neonatal lymph nodes contained mature frequencies of IFN-gamma- and IL-4-producing cells. In striking contrast, while mature frequencies of Th2 cells developed in neonatal spleens, virtually no IFN-gamma-secreting cells were detected. Exclusive Th2 function was observed in both BALB/c and C57BL/6 neonates, strains in which the Th2 and Th1 lineages, respectively, are favored in adults. Although Th1 effectors were virtually undetectable, the addition of rIL-12 boosted the frequency of IFN-gamma-secreting cells to adult levels. Therefore, Th1 effectors apparently developed in situ, but Th1 effector function either was not promoted or was inhibited upon subsequent exposure to the Ag in culture. Together, these results indicate that the quality of a primary Th response in neonates is strongly dependent on the site of initial Ag exposure; responses initiated in the lymph nodes are mixed Th1/Th2, whereas responses occurring in the spleen are heavily Th2 biased.

Mitogenic signaling by ATP/P2Y purinergic receptors in astrocytes: involvement of a calcium-independent protein kinase C, extracellular signal-regulated protein kinase pathway distinct from the phosphatidylinositol-specific phospholipase C/calcium pathway

Activation of ATP/P2Y purinergic receptors stimulates proliferation of astrocytes, but the mitogenic signaling pathway linked to these G-protein-coupled receptors is unknown. We have investigated the role of extracellular signal-regulated protein kinase (ERK) in P2Y receptor-stimulated mitogenic signaling as well as the pathway that couples P2Y receptors to ERK. Downregulation of protein kinase C (PKC) in primary cultures of rat cerebral cortical astrocytes greatly reduced the ability of extracellular ATP to stimulate ERK. Because occupancy of P2Y receptors also leads to inositol phosphate formation, calcium mobilization, and PKC activation, we explored the possibility that signaling from P2Y receptors to ERK is mediated by a phosphatidylinositol-specific phospholipase C (PI-PLC)/calcium pathway. However, neither inhibition of PI-PLC nor chelation of calcium significantly reduced ATP-stimulated ERK activity. Moreover, a preferential inhibitor of calcium-dependent PKC isoforms, Gö 6976, was significantly less effective in blocking ATP-stimulated ERK activity than GF102903X, an inhibitor of both calcium-dependent and -independent PKC isoforms. Furthermore, ATP stimulated a rapid translocation of PKCdelta, a calcium-independent PKC isoform, but not PKCgamma, a calcium-dependent PKC isoform. ATP also stimulated a rapid increase in choline, and inhibition of phosphatidylcholine hydrolysis blocked ATP-evoked ERK activation. These results indicate that P2Y receptors in astrocytes are coupled independently to PI-PLC/calcium and ERK pathways and suggest that signaling from P2Y receptors to ERK involves a calcium-independent PKC isoform and hydrolysis of phosphatidylcholine by phospholipase D. In addition, we found that inhibition of ERK activation blocked extracellular ATP-stimulated DNA synthesis, thereby indicating that the ERK pathway mediates mitogenic signaling by P2Y receptors.

Hypericum LI 160 inhibits uptake of serotonin and norepinephrine in astrocytes

Extracts of Hypericum perforatum, commonly known as St. John's wort, are frequently used in Germany and other European countries to treat mild to moderately severe depression, but the mechanism of antidepressant activity of Hypericum is not understood. Because known mechanisms of antidepressant activity include inhibition of serotonin and/or norepinephrine uptake, we investigated the effects of standardized extracts of Hypericum LI 160 on the transport of these monoamine neurotransmitters into astrocytes, cells which surround synaptic terminals and regulate neurotransmission by means of their uptake systems. We found that LI 160 inhibited both serotonin and norepinephrine uptake in a dose-dependent manner. The two monoamine transport systems were affected differently by LI 160: for serotonin, the main effect was a 50% decrease in the rate of maximal transport, whereas for norepinephrine, the main effect was a 4.5 fold reduction in the apparent affinity of norepinephrine for its uptake sites. Upon removal of LI 160, uptake was restored, thereby indicating that the inhibition was not due to a toxic effect of Hypericum on the cells. These findings suggest that the ability of LI 160 to inhibit serotonin and norepinephrine uptake may underlie the antidepressant activity of this Hypericum extract.

[The change of salivary beta 2-microglobulin concentration in normal adults]

OBJECTIVE

To understand the influence of various physiological factors on the concentration of beta 2-microglobulin in saliva.

METHODS

We measured salivary beta 2-microglobulin concentration in 200 normal adults, from 21 year-old to 70 year-old, by means of radioactive immunoassay method.

RESULTS

We found, that there was no significant difference between males and females in salivary beta 2-m concentration, and salivary beta 2-m concentration was more significantly elevated in the adults above 50 year-old, compared with the adults from 21 year-old to 50 year-old. We also found, that there was no significant correlation between salivary beta 2-m concentration and serum beta 2-m concentration.

CONCLUSIONS

Our results suggested, that beta 2-m in saliva may be produced in oral cavity and salivary glands, and measurement of salivary beta 2-m concentration may offer a valuable method to diagnose lymphocytic infiltration disease in oral cavity or salivary glands.

Identification of cis-acting elements in the SUC2 promoter of Saccharomyces cerevisiae required for activation of transcription

We analyzed the effects of site-directed mutations in the SUC2 promoter of Saccharomyces cerevisiae. Analyses were performed in wild-type as well as mig1 and tup1 mutant strains after the promoter mutants were reintroduced into the native SUC2 locus on the left arm of chromosome IX. Mutation of the two GC boxes revealed that these elements play two distinct roles: they are, as expected, required for Mig1-mediated repression but they are also necessary for activation of the SUC2 promoter in response to glucose limitation. The individual GC boxes are functionally redundant with regard to Mig1-mediated repression, however, only the upstream GC box is essential for high level expression of SUC2. Microccocal nuclease sensitivity of the SUC2 promoter in derepressed cells was reduced in the GC box mutant promoters, particularly in the vicinity of the TATA box. The difference in nuclease sensitivity between wild-type and GC box mutant promoters was not evident in tup1- cells. The formation of nuclease-resistant chromatin does not require the GC boxes, indicating that other cis-acting elements can serve to recruit the Ssn6-Tup1 co-repressor complex to the SUC2 promoter.

[Microwave extraction technique]

A new microwave aided extraction (MAE) technique is introduced in this paper. It gives the extraction method as well as reagents, equipment and conditions used in the technique. In temperature controlled pressurized vessels, polar solvent (eg. acetone) and the combinations of polar and non-polar solvents can be heated to approximately 100 degrees C above their normal boiling points. It is told that the higher the extraction temperature the more the recovery is. The ratio of polar to non-polar solvents affects not only the microwave heating rate but also the extraction recovery. The highest recovery ratios are gotten at the solvent ratio of three parts of acetone to two parts of hexane. We can see from the pesticides chromatogram with MAE, that very little break-down of endrin or DDT are detected and they are well below the EPA specified tolerance limits. We can find from the comparison of MAE with sonication and Soxhlet extraction techniques that microwave extraction technique has not only higher average recoveries (%) but also good precision (RSD, %). The data and comparison results illustrate that the microwave extraction is a rapid method (about 15 minutes) with less solvent consumption (about 30-50 mL), good recovery, and easy to be controlled automatically in comparison with the Soxhlet extraction, sonication and other extraction methods.

Vasoactive intestinal peptide stimulates the growth of rat hepatoma cells in vitro

Using tetrazolium colorimetric assay (MTT assay) and cell counting methods, the effect of vasoactive intestinal peptide (VIP) on the growth of cultured rat hepatoma FSK-7902 cells was investigated. The results showed that VIP obviously stimulated the proliferation of the rat hepatoma cells. The growth promoting effect increased with VIP concentration. Exposure to VIP for 12 h followed by removal of the peptide resulted in sustained growth promotion for several days.