Felodipine downregulates serum interleukin-18 levels in rats with fructose-induced metabolic syndrome

OBJECTIVE

Human studies suggest that calcium-channel blockers have cardiovascular protection besides reducing blood pressure, and interleukin-18 (IL-18) levels which are elevated in obese population are associated with metabolic syndrome (MetS). The purpose of this research was to study the change of serum IL-18 levels and the effect of felodipine on it in high-fructose diet-fed rats.

METHODS

In this research, 30 Wistar male rats were randomized into 3 groups. A control group (no.=12) was fed with normal feeds, and high-fructose diet was given to a fructose group and a flodioine group (no.=9 in each group). All animals were fed for a period of 32 weeks, during which body weight and systolic blood pressure (BP) were measured once every 4 weeks. Felodipine (5 mg/kg/d) was then administered by gavage daily for 6 weeks to the felodipine group. Before and after treatment with felodipine, fasting plasma lipid, blood glucose, plasma insulin, and serum IL-18 were detected.

RESULTS

Body weight, systolic BP, triglycerides, fasting insulin, and the R-value of homeostasis model (HOMA-R) were significantly increased in high-fructose rats (p<0.01). Serum IL-18 levels were elevated and had significant positive correlation with HOMA-R in rats with fructose-induced MetS (p<0.01). We also found that felodipine may decrease HOMA-R and serum IL-18 levels besides reducing blood pressure (p<0.05, p<0.01).

CONCLUSION

IL-18 plays an important role in the development of MetS, while felodipine exerts an anti-inflammatory effect on rats with fructose-induced MetS by downregulating serum IL-18 levels.

Differential regulation of collagen types I and III expression in cardiac fibroblasts by AGEs through TRB3/MAPK signaling pathway

Advanced glycation end products (AGEs) play an important role in collagen deposition in diabetic cardiomyopathy. TRB3, a mammalian homolog of Drosophila tribbles, functions to increase glucose intolerance and regulates cell proliferation. We demonstrated that AGEs induce collagen type I expression but inhibit collagen type III expression, accompanied by increased TRB3 expression. Furthermore, the collagen type I induced byAGEs was down-regulated after inhibition of ERK and p38-MAPK, the collagen type III reduced by AGEs was up-regulated after inhibition of ERK. The expression of collagen types I and III regulated by AGEs through MAPK was partly reversed after treatment with TRB3 siRNA. It suggests that the TRB3/MAPK signaling pathway participates in the regulation of collagen types I and III by AGEs and may provide new therapeutic strategies for diabetic cardiomyopathy.

Heterogeneity in gene loci associated with type 2 diabetes on human chromosome 20q13.1

Human chromosome 20q12-q13.1 has been linked to type 2 diabetes mellitus (T2DM) in multiple studies. We screened a 5.795-Mb region for diabetes-related susceptibility genes in a Caucasian cohort of 310 controls and 300 cases with T2DM and end-stage renal disease (ESRD), testing 390 SNPs for association with T2DM-ESRD. The most significant SNPs were found in the perigenic regions: HNF4A (hepatocyte nuclear factor 4alpha), SLC12A5 (potassium-chloride cotransporter member 5), CDH22 (cadherin-like 22), ELMO2 (engulfment and cell motility 2), SLC13A3 (sodium-dependent dicarboxylate transporter member 3), and PREX1 (phosphatidylinositol 3,4,5-triphosphate-dependent RAC exchanger 1). Haplotype analysis found six haplotype blocks globally associated with disease (p<0.05). We replicated the PREX1 SNP association in an independent case-control T2DM population and inferred replication of CDH22, ELMO2, SLC13A3, SLC12A5, and PREX1 using in silico perigenic analysis of two T2DM Genome-Wide Association Study data sets. We found substantial heterogeneity between study results.

Neurogenesis and neurodegenerative diseases in human

Acute and chronic neurodegenerative diseases are the most common neurological disorders in human and affect millions of individuals worldwide. While the specific clinical presentation varies among such diseases, their common feature is neural cell death. Yet, despite major advances in the understanding of neural cell death, effective treatment for these diseases remains one of the foremost challenges for medicine today. The transplantation of embryonic cells into the diseased brain in human has emerged out a mere theory and is possible as a practical application. This advancement, however, has raised important ethical, technical and immunological concerns. Studies have documented that neurogenesis occurs in the adult brain and that endogenous neural stem/progenitor cells (NSCs) respond to neurodegenerative diseases, suggesting that it might be possible for dead or injured neural cells to be replaced by endogenous NSCs. In this regard it is especially interesting to know the biological behaviors of endogenous NSCs in response to neurodegenerative diseases. Understanding the mechanisms underlying these changes could lead to the development of new strategies for treating neurological diseases using endogenous NSC pool.

Sex-specific regulation of growth plate chondrocytes by estrogen is via multiple MAP kinase signaling pathways

Both male and female rat growth plate cartilage cells possess estrogen receptors (ERs), but 17beta-estradiol (E(2)) activates protein kinase C (PKC) and PKC-dependent biological responses to E(2) only in cells from female animals. PKC signaling can elicit genomic responses via mitogen activated protein kinase (MAPK) and E(2) has been shown to activate ERK MAPK in many cells, suggesting that MAPK may play a role in growth plate chondrocytes as well. We tested if E(2) increases MAPK activity and if so, whether the response is limited to female cells, if it is PKC-dependent, and if the mechanism involves traditional ER pathways. We also determined the contribution of MAPK to the biological response of growth plate chondrocytes and assessed the relative contributions of ERK, p38 and JNK MAPKs. Female rat costochondral cartilage cells were treated with E(2) and MAPK-specific activity determined in cell layer lysates. The mechanism of MAPK activation was determined by treating the cells with E(2) conjugated to bovine serum albumin (E(2)-BSA) to assess if membrane receptors were involved; stereospecificity was determined using 17alpha-estradiol; PKC and phospholipase C (PLC) dependence was determined using specific inhibitors; and the ER agonist diethylstilbestrol, the ER antagonist ICI 182780, and tamoxifen were used to assess the role of traditional ER pathways. E(2) regulation of ERK1/2 MAPK was assessed and the relative roles of ERK1/2, p38 and JNK MAPKs determined using specific inhibitors. E(2) caused a rapid dose-dependent activation of MAPK that was greatest in cells treated for 9 min with 10(-9) M hormone; activity remained elevated for 3 h. E(2)'s effect on MAPK was stereospecific and comparable to that of E(2)-BSA. It was insensitive to DES and ICI 182780, dependent on PKC and PLC, blocked by tamoxifen and it did not require gene transcription or translation. E(2) had no effect on ERK1 or ERK2 mRNA or protein but it caused a rapid phosphorylation of ERK1/2 at 9 min. Inhibition of ERK1/2 and p38 MAPK reduced the stimulatory effects of E(2) on alkaline phosphatase activity and [(35)S]-sulfate incorporation. These results suggest that E(2) regulates MAPK through a sex-specific membrane-mediated mechanism that does not involve cytosolic ERs in a traditional sense and that ERK1/2 and p38 mediate the downstream biological effects of the hormone.

The prevalence and spectrum of alpha and beta thalassaemia in Guangdong Province: implications for the future health burden and population screening

AIM

Thalassaemia is a good candidate disease for control by preventive genetic programmes in developing countries. Accurate population frequency data are needed for planning the control of thalassaemia in the high risk Guangdong Province of southern China.

METHODS

In total, 13397 consecutive samples from five geographical areas of Guangdong Province were analysed for both haematological and molecular parameters.

RESULTS

There was a high prevalence of carriers of alpha thalassaemia (8.53%), beta thalassaemia (2.54%), and both alpha and beta thalassaemia (0.26%). Overall, 11.07% of the population in this area were heterozygous carriers of alpha and beta thalassaemia. The mutation spectrum of alpha and beta thalassaemia and its constitution were fully described in this area. This study reports the true prevalence of silent alpha thalassaemia in the southern China population for the first time. In addition, two novel mutations that give rise to alpha thalassaemia, one deletion resulting in beta thalassaemia, and a rare deletion (--(THAI) allele) previously unreported in mainland China were detected. The frequency of the most common mutation, the Southeast Asian type of deletion (--(SEA), accounting for 48.54% of all alpha thalassaemias) was similar to the total of two alpha(+) thalassaemia deletions (-alpha(3.7) and -alpha(4.2), accounting for 47.49% of alpha thalassaemia).

CONCLUSION

Both alpha and beta thalassaemia are widely distributed in Guangdong Province of China. The knowledge gained in this study will enable the projected number of pregnancies at risk to be estimated and a screening strategy for control of thalassaemia to be designed in this area.

[Expression of WT1 gene mRNA in leukemia]

WT1 gene expression was determined in acute leukemic patients by RT-PCR.

RESULTS

19 patients were found to have positive results among 28 patients, the positive rate is 67.9%, and in 16 ANLL patients, 11 cases got positive results, in 12 ALL patients, 8 cases got positive results. It suggested that WT1 was highly expressed in acute leukemia. It is a new and significant detective marker for monitoring the effect of chemotherapy, predicting the prognosis and in the research of minimal residual disease (MRD).

Clearance of quinupristin-dalfopristin (Synercid) and their main metabolites during continuous veno-venous hemofiltration (CVVH) with or without dialysis

BACKGROUND

Quinupristin-dalfopristin (Q/D) is often utilized in critically ill patients, some of whom require CVVH. This study was undertaken to determine the clearance of O/D and their main active metabolites (RPR 100391, RP 69012, RP 12536) via CVVH in the swine model.

METHODS

Q/D 7.5 mg/kg was intravenously administered over 0.5 h to 12 swine after induction of acute renal failure by ligation of the renal arteries. At 0.5 h post injection, the CVVH procedure was initiated and continued for 8 hours at the following pump rates: (1)100 mL/min, (2)180 rnL/min, and (3)100 mL/min with dialysis (flow rate: 1 L/h). Blood and ultrafiltrate samples were collected at 1 h intervals and assessed by a validated HPLC method.

RESULTS

Plasma analysis suggests rapid metabolism to the main active metabolites which are appreciably cleared as demonstrated by high clearance and sieving coefficient estimates. Mean clearance estimates for RP 69012, RP 100391, and RP 12536 are 729, 777, and 578 mL/h in the 100 mL/min CVVH group, 772, 785, 685 mL/min in the 180 mL/min CVVH group, and 753, 791, 616 mL/min in the 100 mL/min CVVH group with 1 L/h dialysis, respectively.

CONCLUSION

These data reveal that Q/D is rapidly metabolized and the metabolites are cleared to a large extent via CVVH. Due to the considerable contribution of the metabolites to overall in vivo activities, additional studies are required to fully quantify their removal before final dosage modifications for patients undergoing CVVH can be recommended.

Transformation of cells overexpressing a tyrosine kinase by phospholipase D1 and D2

Phospholipase D (PLD) activity is elevated in response to most mitogenic signals. Two mammalian PLD genes (PLD1 and PLD2) have been cloned and their gene products have been characterized. PLD1 is a downstream target of the Ras/RalA GTPase cascade implicated in mitogenic and oncogenic signaling. Consistent with a role in mitogenic signaling, elevated expression of PLD1 transforms cells overexpressing the epidermal growth factor (EGF) receptor (EGFR). However, PLD2 colocalizes with the EGFR in caveolin-enriched light membrane microdomains. We therefore investigated whether PLD2 could also contribute to the transformation of cells overexpressing a tyrosine kinase. We report here that elevated expression of PLD2 transforms rat fibroblasts overexpressing either the EGFR or c-Src. Since overexpression of a tyrosine kinase is a common genetic alteration in several human cancers, these data suggest that elevation of either PLD1 or PLD2 may contribute to the progression to a malignant phenotype in cells with elevated tyrosine kinase activity.

Insight into hepatocellular carcinogenesis at transcriptome level by comparing gene expression profiles of hepatocellular carcinoma with those of corresponding noncancerous liver

Human hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. In this work, we report on a comprehensive characterization of gene expression profiles of hepatitis B virus-positive HCC through the generation of a large set of 5'-read expressed sequence tag (EST) clusters (11,065 in total) from HCC and noncancerous liver samples, which then were applied to a cDNA microarray system containing 12,393 genes/ESTs and to comparison with a public database. The commercial cDNA microarray, which contains 1,176 known genes related to oncogenesis, was used also for profiling gene expression. Integrated data from the above approaches identified 2,253 genes/ESTs as candidates with differential expression. A number of genes related to oncogenesis and hepatic function/differentiation were selected for further semiquantitative reverse transcriptase-PCR analysis in 29 paired HCC/noncancerous liver samples. Many genes involved in cell cycle regulation such as cyclins, cyclin-dependent kinases, and cell cycle negative regulators were deregulated in most patients with HCC. Aberrant expression of the Wnt-beta-catenin pathway and enzymes for DNA replication also could contribute to the pathogenesis of HCC. The alteration of transcription levels was noted in a large number of genes implicated in metabolism, whereas a profile change of others might represent a status of dedifferentiation of the malignant hepatocytes, both considered as potential markers of diagnostic value. Notably, the altered transcriptome profiles in HCC could be correlated to a number of chromosome regions with amplification or loss of heterozygosity, providing one of the underlying causes of the transcription anomaly of HCC.

[Microsurgical treatment of 86 cases of intracranial aneurysms]

OBJECTIVE

To summarize the microsurgical experience in the treatment of intracranial aneurysms.

METHOD

The clinical materials, surgical modes and prognosis of 86 cases of clipped intracranial aneurysms were retrospectively reviewed.

RESULTS

Of the 86 cases, 69 recovered, 10 were moderately disabled, 2 severely disabled, and 5 died.

CONCLUSIONS

To avoid rerupture, aneurysms should be treated as soon as possible when the diagnosis was established. Proper management of rupture of aneurysms during operation is the key of success. Multiple aneurysms are better to be clipped in one stage. "de novo" aneurysms could be detected early by long-term angiography.

[Molecular mechanism underlying calcium handling in diastolic heart failure]

OBJECTIVE

To elucidate the molecular mechanism underlying calcium handling in diastolic heart failure (DHF) from mRNA level and protein expression, including L-type calcium channel, sarcoplasmic reticulum (SR) Ca(2+)-ATPase, phospholamban, ryanodine receptor, calsequestrin.

METHODS

DHF was produced in rabbits by abdominal aortic coarctation. The mRNA amounts of these calcium-handling genes were measured by RT-PCR, while the protein levels of SR Ca(2+)-ATPase and phospholamban were analyzed by Western blot analysis.

RESULTS

The content of calcium was significantly increased in myocardium of rabbits with DHF than in the myocardium of sham-operated rabbits. The SR Ca(2+)-ATPase activity of DHF rabbits was significantly reduced compared with that in sham-operated rabbits (21.1 micromol.mg(-1).h(-1) +/- 5.7 micromol.mg(-1).h(-1) vs 10.5 micromol.mg(-1).h(-1) +/- 2.8 micromol.mg(-1).h(-1), P < 0.01). RT-PCR analyses showed that the steady-state level of mRNA encoding the L-type calcium channel and SR Ca2+-ATPase was decreased significantly in rabbits with DHF compared with that in the sham-operated rabbits (micromol.mg(-1).h(-1)): 0.75 +/- 0.11 vs 1.20 +/- 0.33; 0.76 +/- 0.12 vs 1.24 +/- 0.38, P < 0.05). The SR Ca(2+)-ATPase mRNA level correlated negatively well with left ventricular relaxation time constant and left ventricular end-diastolic pressure (r = -0.81, -0.64, respectively, P < 0.05 approximately 0.01); the mRNA level of L-type calcium channel correlated negatively with left ventricular end-diastolic pressure (r = -0.74, P < 0.05). The mRNA level of ryanodine receptor correlated negatively with the left ventricular relaxation time constant too (r = -0.71, P < 0.05). Protein level of SR Ca(2+)-ATPase was significantly lower in rabbits with DHF than in the sham-operated rabbits (0.76 +/- 0.6 vs 1.02 +/- 0.09, P < 0.05), whereas the protein level of phospholamban was unchanged.

CONCLUSION

The L-type calcium channel and SR Ca(2+)-ATPase were down regulated in DHF. These changes may be a contributory factor for DHF.

[Transfusion transmitted virus infection in mother-to-infant transmission]

OBJECTIVE

To investigate the perinatal infection of transfusion transmitted virus (TTV) in the mother-to-infant transmission and molecular evidence.

METHODS

TTV was examined in serum from 104 mothers and umbilical blood of their infants by a semi-nested polymerase chain reaction technique. TTV nucleotide sequences isolated from two sets of mother/infant pairs were analyzed.

RESULTS

The TTV detection rate was 13.46% (15/104), and it was 4.81% (5/104) in the umbilical blood of their newborns. Homology analysis was done by sequencing between positions 1,915 and 2,185 of the published TTV genome, Analysis of TTV sequences from the 2 pairs of mother and infant both infected confirmed a genetic link between the virus of the infected mother and their infected infants.

CONCLUSIONS

There is a possibility of vertical maternal-fetal transmission of TTV.

[Rapid detection of the common alpha-thalassemia-2 determinants by PCR assay]

OBJECTIVE

Most frequent molecular lesions of alpha-thalassemia-2 determinants are deletions of one alpha-globin gene. Satisfactory PCR methodologies for detecting the deletions are required for molecular diagnosis and genetic screening since there was no internal control in most published PCR-based strategies. The purpose of this study is to develop a reliable PCR protocol specific for the two common alpha-thalassemia-2 determinants with internal control.

METHODS

The multiple repeat elements and the high GC-content of the alpha-globin locus impose severe limitations on designing suitable primers and optimizing stable conditions for PCR. In this study, two multiplex PCR systems were successfully set up. One was designed to detect the rightward deletion (-alpha(3.7)/) with two pairs of primers including one newly optimized pair for amplification of the internal standard to indicate the success of failure of PCR amplification. The other, to the leftward deletion(-alpha(4.2)/) with three primers, which were designed according to the newly sequenced data of the -alpha(4.2) and HbQ-alpha(4.2) deletions in this lab(Genbank Accession No. AF221717). In the PCR system, one is used as a common upstream primer and the other two are used as specific downstream primers for typing the normal allele and the deletion one, respectively.

RESULTS

Easily interpretable, unambiguous amplifications were observed by using the multiplex PCR systems for the detection of the two common alpha-thalassemia-2 determinants. The three or four primers were run in the same tube under the same condition and both of these two systems could be used at the same thermal cycle parameters. For typing the rightward deletion, a mutant-specific amplification of 1.7 kb and a 1140 bp amplified band as a normal and system control were produced. For typing the leftward deletion, two PCR-amplified bands, a 956 bp fragment specific for a -alpha(4.2) gene and a 1140 bp one for a normal allele were found.

CONCLUSION

Two sets of PCR systems with internal controls for detecting the most common two alpha-thalassemia-2 determinants have been established and may be suitable for molecular diagnosis and population screening.

IgE production is involved in butyrate-enhanced NK cell activity in vivo

It has been demonstrated that patients with asthma have a large number of NK cells and show a stronger NK activity. These results indicate that NK cell activity may be related to total IgE level in serum in healthy subjects. Previously, we have found that sodium butyrate (NaBu) markedly enhanced the IL-4-induced IgE production in the LPS-stimulated murine splenocytes in vitro, and inductive rat IgE production in vivo, and enhanced the NK cell activity ex vivo. We hypothesized that the IgE production might be involved in butyrate-enhanced NK cell activity in vivo. Mice were intraperitoneally treated/immunized with NaBu or/and Ascaris suum extract (ASC), and the spleen NK cell activity was evaluated. Furthermore, the effect of serum (NAS) on IL-2- or IFN-gamma-induced spleen NK cell activity was determined. The spleen NK cell activity and IL-2- or IFN-gamma-induced spleen NK cell activity of mice treated/immunized with NaBu or/and ASC were stronger than those of untreated/unimmunized mice. Although IL-4 blocked IL-2 (100 U/ml)- or IFN-gamma (100 U/ml)-induced increase in NK cell activity, these NK cell activities in mice treated/immunized with NaBu/ASC were not inhibited. IgE production showed a tendency to rise in NaBu-treated mice serum, and a synergistic effect was observed with treatment of NaBu and ASC. Moreover, the NAS significantly increased IL-2(25 U/ml)-or IFN-gamma(25 U/ml)-induced NK cell activity, and its effect was inhibited by anti-mouse IgE mAb. These data show that IgE plays an important role in NAS-enhanced IL-2/IFN-gamma-induced NK cell activity, and IL-4 does not inhibit IgE and IL-2/IFN-gamma-induced NK cell activity in mice.

Clinical evaluation of a new technique for interdental enamel reduction

In orthodontics, reduction of tooth-size by grinding interproximal surfaces (stripping) of teeth is a common procedure. In order to achieve perfectly smooth surfaces, clinicians have carefully tested various methods and progressively improved this therapeutic procedure. In this in-vivo study we used scanning electron microscopy (SEM) to evaluate the morphologic effect of a 3-step technique using an oscillating perforated diamond-coated disc for enamel reduction and 2 Sof-Lex XT discs for polishing. This technique was applied in 32 patients with an average age of 15.5 years. A total of 296 interproximal surfaces was treated and replicas were produced for scanning electron microscopy evaluation. The scanning electron microscopy investigations demonstrated that more than 90% of the reproximated surfaces were very well or well polished, resulting in polished enamel surfaces smoother than untreated enamel. This technique proved to be clinically expedient as it finished each interproximal surface within about 2.2 minutes. At the same time, it was demonstrated to be safe and comfortable for the patient, eliminating the need for lip or cheek protectors and making injuries unlikely.

[Expression of heparanase gene and the metastatic activity of lung cancer]

BACKGROUND

To investigate the relationship between the expression of heparanase gene and the metastatic activity of lung cancer.

METHODS

Using the primers of heparanase gene, the expression of heparanase gene was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in two giant cell lung cancer cell lines with different metastatic activity and 56 primary tumor tissues of lung cancer and normal lung tissues.

RESULTS

Both cell lines and 80% (20/25) of primary tumor tissues of lung cancer with lymph node metastasis showed positive expression of heparanase gene, whereas 6.5% (2/31) primary tumor tissues of lung cancer without lymph node metastasis was positive and the normal lung tissues were all negative. The positive rate for expression of heparanase gene was significantly higher in the tumor tissues with lymph node metastasis than that without lymph node metastasis (P<0.001), higher in squamous cell carcinoma (47.2%, 17/36) than that in adenocarcinoma (20%, 4/20)(P<0.05), and remarkably higher in the poorly differentiated tumors (65%, 13/20) than that in the well-mediate differentiated tumors (22.2%, 8/36)(P<0.01).

CONCLUSIONS

The preliminary results suggest that the expression of heparanase gene may be one of the reliable markers for the metastastic activity gained by the lung cancer cells and could be used clinically in predicting the prognosis of patients.

Novel tumor-promoting property of tamoxifen

The tumor-promoting phorbol ester TPA (12-O-tetradecanoylphorbol-13-acetate) cooperates with c-Src overexpression to transform rat fibroblasts. TPA transforms c-Src-overexpressing cells by depleting the delta isoform of protein kinase C (PKCdelta). Tamoxifen, which has both estrogen-mimetic and estrogen-antagonist properties, has been widely used to improve the prognosis of breast cancer patients. However, with extended use, there is an increased risk for endometrial and other cancers that can be observed within 10 years of treatment. We report here that tamoxifen, similar to TPA, cooperates with c-Src overexpression to transform 3Y1 rat fibroblasts. Tamoxifen induced both DNA synthesis and anchorage-independent cell proliferation in c-Src-overexpressing, but not in parental, 3Y1 rat fibroblasts. Tamoxifen also induced an association between c-Src and PKCdelta that resulted in the tyrosine phosphorylation and down-regulation of PKCdelta. These phenotypes were not induced by estrogen, indicating that the effect of tamoxifen was in addition to any estrogen-mimetic effects. Thus, in addition to the hyperplasia-inducing capability of an estrogen-mimetic, tamoxifen has an additional tumor-promoting capability similar to that of TPA. The dual tumor-promoting capability of both estrogen- and TPA-mimetic properties for tamoxifen may contribute to the increased incidence of endometrial cancers observed in the relatively short exposure period of <10 years.