A Y-shape-structured electrochemiluminescence biosensor based on carbon quantum dots and locked nucleic acid probe for microRNA determination with single-base resolution

Since microRNAs (miRNAs) are predictors of tumorigenesis, accurate identification and quantification of miRNAs with highly similar sequences are expected to reflect tumor diagnosis and treatment. In this study, a highly selective and sensitive electrochemiluminescence (ECL) biosensor was constructed for miRNAs determination based on Y-shaped junction structure equipped with locked nucleic acids (LNA), graphene oxide-based nanocomposite to enrich luminophores, and conductive matrix. Specifically, two LNA-modified probes were designed for specific miRNA recognition, that is, a dual-amine functionalized hairpin capture probe and a signal probe. A Y-shaped DNA junction structure was generated on the electrode surface upon miRNA hybridizing across the two branches, so as to enhance the selectivity. Carbon quantum dots-polyethylene imine-graphene oxide (CQDs-PEI-GO) nanocomposites were developed to enrich luminophores CQDs, and thus enhancing the ECL intensity. For indirect signal amplification, an electrochemically activated poly(2-aminoterephthalic acid) (ATA) film decorated with gold nanoparticles was prepared on electrode as an effective matrix to accelerate the electron transfer. The fabricated ECL biosensor achieved sensitive determination of miRNA-222 with a limit-of-detection (LOD) as low as 1.95 fM (S/N = 3). Notably, Y-shaped junction structures equipped with LNA probes endowed ECL biosensor with salient single-base discrimination ability and anti-interference capacity. Overall, the proposed Y-shaped ECL biosensor has considerable promise for clinical biomarker determination.

[Advances in clinical studies of chronic cough]

Chronic cough is a common complaint in respiratory specialist clinics, with a significant impact on cough-specific quality of life and psychophysiological health. The diagnosis, treatment and management of chronic cough remains a major challenge. We summarized a series of recent advances from clinical studies in the epidemiology, diagnosis and management of chronic cough over the past year.

An electrochemiluminescence resonance energy transfer biosensor based on CDs/PAMAM/rGO nanocomposites and Au@Ag2S nanoparticles for PML/RARα fusion gene detection

In recent years, electrochemiluminescence resonance energy transfer (ECL-RET) with low background signal and high specificity has attracted much attention among researchers. Herein, we established a novel ECL-RET biosensor for PML/RARα fusion gene detection. In this ECL-RET system, carbon dots (CDs) with low toxicity and prominent electrochemical activity were used as donor and Au@Ag2S core-shell nanoparticles (Au@Ag2S NPs) were employed as ECL acceptor. The Au@Ag2S NPs possessed a wide ultraviolet-visible (UV-vis) absorption spectrum between 500 nm and 700 nm, which completely overlapped with the ECL spectrum of CDs. Furthermore, the CDs-decorated poly-amidoamine/reduced graphene oxide (CDs/PAMAM/rGO) nanocomposites were prepared to improve the ECL signals and served as a substrate to stably load capture probe deoxyribonucleic acid (DNA). Based on the ECL-RET biosensing strategy, the Au@Ag2S NPs-labeled assistant probes and target DNA could pair with capture probes to form the sandwich-type DNA structure and the distance between donor and accepter was closed, leading to quenching of the ECL signal of CDs. The ECL-RET biosensor represented eminent analytical performance for PML/RARα fusion gene detection with a wide linear relationship from 5 fM to 500 pM and a low detection limit of 0.72 fM, which provided a novel technical means and theoretical basis for detection and diagnosis of acute promyelocytic leukemia.

Investigate clinical characteristics and genetic mutations of CPVT patients in Taiwan and risk stratification

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology

Background

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and lethal arrhythmia in children and young adults. RYR2 mutation accounts for 60% of CPVT patients. While many articles about CPVT are published in the Caucasian population, only a few studies are based on Asian ethnicity. A CPVT scorecard proposed using Caucasian patients is proven effective in reducing the burden of variants of uncertain significance (VUS) of RYR2 mutations is not yet tested in the Asian population.

Purpose

Identify mutations among Taiwanese CPVT patients and compare genetic and clinical results with other ethnicities. We also tested the efficacy of the CPVT scorecard in Taiwanese CPVT patients.

Methods

40 clinically diagnosed CPVT patients and their family members were consecutively enrolled from multi-centers. We compared clinical characteristics and genetic results with other ethnicities, and applied the Caucasian CPVT scorecard to test whether it is applicable in Taiwanese CPVT patients.

Results

This is the first nationwide CPVT cohort in Taiwan. Among the 29 patients with CPVT-related gene mutation, 12 RYR2 variants was identified in our cohort with 5 of them unreported in previous studies. The RYR2 yield rate was 55%, similar to other ethnicities. Exercise-induced symptoms including syncope and cardiac arrest were more severe in Taiwanese CPVT cohort, compared to Japanese and Caucasian cohorts. The CPVT scorecard also successfully reduced the VUS rate for the Taiwanese cohort.

Conclusions

Our study demonstrated genetic difference in CPVT patients across ethnicities, suggesting the importance of genetic testing in Taiwan. The CPVT scorecard is applicable to Taiwanese CPVT patients and is a helpful tool in interpreting genetic test results in clinical practice. Clinical characteristics of the cohort Gender (male, %) 15 (52%) Mean age of onset (years) 18 ± 15 Exercise-related syncope or cardiac arrest (n, %) 23 (79%) Exercise-related cardiac arrest (n, %) 14 (48%) Family history of unexplained sudden cardiac death (n, %) 5 (17%) Heart rate (bpm) 73 ± 16 Exercise stress test or Holter positive (n, %) 14 (48%) Ventricular arrhythmia (n, %) 23 (79%) Beta-blockers only (n, %) 10 (35%) Intracardiac defibrillator implantation (n, %) 15 (52%) CPVT score 6 ± 3

A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model

We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05) and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use.

Hypothermic effect of sodium acetysalicylate on afebrile monkeys

1 Afebrile monkeys (Macaca cyclopis) receiving systemic (100-300 mg/kg, i.p.) or central (5-20 mg into the 3rd cerebral ventricle) administration of sodium acetylsalicylate showed a dose-dependent reduction in rectal temperature in a thermoneutral environment (25 degrees C).2 Administration of sodium acetylsalicylate (10 mg) into the 3rd cerebral ventricle produced a hypothermia with a temperature decrement of 1.0 degrees C, ehile an intraperitoneal injection of 300 mg/kg was required for a temperature decrement of 0.9 degrees C. The ratio between the total doses given by the two toutes was 1 to 120.3 Following the administration of sodium acetylsalicylate, a decline in rectal temperature was accompanied by a tail cutaneous vasodilatation.4 The data suggest that sodium acetylsalicylate can lower the normal body temperature by activating heat loss or decreasing the normal (tonic) inhibition of the heat loss mechanism via the central nervous system.

Group A streptococcal infection caused by emm1 strains among children in southern Taiwan

The aim of this study was to characterize the molecular epidemiology of invasive and non-invasive group A streptococcus (GAS) infections in children from 1997 through 2004 in southern Taiwan. A collection of 32 invasive and 150 non-invasive isolates were recruited for analysis. emm1 (34.4%) and emm12 (40.0%) predominated in the invasive and non-invasive isolates, respectively. The peak incidence of invasive GAS infection (IGASI) occurred between 2002 and 2003. emm4 and emm12 were the major types among clinical isolates before 2001, and was replaced by emm1 during 2002-2003. All emm1 isolates were clonal relatedness. The declined prevalence of erythromycin resistance occurred in the major shift of the endemic isolates to emm1 strains during 2002-2003 in the community.

Streptococcal pyrogenic exotoxin B antibodies in a mouse model of glomerulonephritis

Streptococcal pyrogenic exotoxin B is an extracellular cysteine protease. Only nephritis-associated strains of group A streptococci secrete this protease and this may be involved in the pathogenesis of post-streptococcal glomerulonephritis. Mice were actively immunized with a recombinant protease inactive exotoxin B mutant or passively immunized with exotoxin B antibody. Characteristics of glomerulonephritis were measured using histology, immunoglobulin deposition, complement activation, cell infiltration, and proteinuria. None of the mice given bovine serum albumin or exotoxin A as controls showed any marked changes. Immunoglobulin deposition, complement activation, and leukocyte infiltration occurred only in the glomeruli of exotoxin B-hyperimmunized mice. One particular anti-exotoxin B monoclonal antibody, 10G, was cross-reactive with kidney endothelial cells and it caused kidney injury and proteinuria when infused into mice. This cross-reactivity may be involved in the pathogenesis of glomerulonephritis following group A streptococcal infection.

Heat shock protein 72 overexpression protects against hyperthermia, circulatory shock, and cerebral ischemia during heatstroke

This study extends our earlier studies in rats by applying our heatstroke model to a new species. Additionally, transgenic mice are used to examine the role of heat shock protein (HSP) 72 in experimental heatstroke. Transgenic mice that were heterozygous for a porcine HSP70i gene ([+]HSP72), transgene-negative littermate controls ([−]HSP72), and normal Institute of Cancer Research strain mice (ICR) under pentobarbital sodium anesthesia were subjected to heat stress (40°C) to induce heatstroke. In [−]HSP72 or ICR, the values for mean arterial pressure, the striatal blood flow, and the striatal Po2after the onset of heatstroke were significantly lower than those in preheat controls. The core and brain temperatures, the extracellular concentrations of ischemic and injury markers in the striatum, and the striatal neuronal damage scores were significantly greater than those in the preheat controls. In [−]HSP72 or ICR, the body temperatures, cell ischemia content, and injury marker in the striatum were significantly higher, and the mean arterial pressure, striatal blood flow, and striatal Po2concentration were significantly lower during heatstroke than in [+]HSP72. Accordingly, the latency and the survival times for [+]HSP72 significantly exceeded those of [−]HSP72 or ICR. These results demonstrate that the overexpression of HSP72 in multiple organs improves survival during heatstroke by reducing hyperthermia, circulatory shock, and cerebral ischemia and damage in mice.

Infusion of human umbilical cord blood cells protect against cerebral ischemia and damage during heatstroke in the rat

Intravenously delivered human umbilical cord blood cells (HUCBC) have been previously shown to improve both morphologic and functional recovery of heat-stroked rats. To extend these findings, we examined both the morphologic and functional alterations in the presence of HUCBC or human peripheral mononuclear cells (PBMC) 24 h before initiation of heatstroke. Anesthetized rats, 1 day before the initiation of heatstroke, were divided into three major groups and given the following: (a) serum-free lymphocyte medium (0.3 ml) intravenously; (b) PBMC (5 x 10(6) in 0.3 ml serum-free lymphocyte medium); or (c) HUCBC (5 x 10(6) in 0.3 ml serum-free lymphocyte medium). Another group of rats were exposed to room temperature (26 degrees C) and used as normothermic controls. In vehicle-treated heatstroke rats, their mean arterial pressure, cerebral blood flow, and brain PO(2) were all lower than in normothermic controls after the onset of heatstroke. However, their body temperatures and striatal levels of inducible nitric oxide synthase (iNOS)-dependent NO, ischemia and damage markers (e.g., glycerol, glutamate, and lactate/pyruvate ratio), and neuronal damage in the striatum were all greater. The heatstroke-induced arterial hypotension, cerebral ischemia and hypoxia, and increased levels of iNOS-dependent NO in the striatum were all significantly reduced by pretreatment with HUCBC, but not with PBMC. Moreover, HUCBC were localized by immunohistochemistry and PCR analysis in the injured brain structures and spleen. These findings indicate that HUCBC transplantation, in addition to having therapeutic values, can be a good choice for preventing heatstroke occurrence.

Improved treatment results for childhood acute myeloid leukemia in Taiwan

To improve treatment results for children with de novo acute myeloid leukemia (AML), we introduced a novel protocol, Taiwan Pediatric Oncology Group-AML-97A, for AML other than acute promyelocytic leukemia (APL), for which modified conventional protocols were used. From January 1, 1997, to December 31, 2002, 141 children younger than 17 years old with de novo AML were enrolled. In total, 117 patients with non-APL AML were treated with induction therapy of idarubicin and cytarabine (Ara-C), postremission therapy with high-dose Ara-C - containing regimens for four monthly courses, and moderate-dose therapy with idarubicin and Ara-C for four monthly courses. The first 19 patients with APL were treated with all-trans retinoic acid, idarubicin and Ara-C, with the remaining five patients receiving all-trans retinoic acid and idarubicin, followed by maintenance therapy for 2 years. Stem cell transplantation was performed in 29 patients in first remission with a similar outcome as chemotherapy alone. The remission rate in the AML-97A study was 90%, the 5-year survival 51 +/- 5.3% (s.e.) and the 5-year event-free survival 50 +/- 4.8%; for APL, these were 100%, 86 +/- 7.0, and 75 +/- 9.8%. For the whole group, the 5-year survival was 57 +/- 4.7% and the 5-year event-free survival 54 +/- 4.4%. The AML-97A regimen was well tolerated.

SHENG MAI SAN, A CHINESE HERBAL MEDICINE, PROTECTS AGAINST RENAL ISCHAEMIC INJURY DURING HEAT STROKE IN THE RAT

1. There is evidence that the induction of inducible nitric oxide synthase (iNOS) and peroxynitrite by ischaemia/reperfusion may lead to renal cell injury. Herein, we investigated whether Sheng mai san (SMS), a Chinese herbal medicine, protects against renal ischaemic injury during heat stroke by reducing iNOS-dependent nitric oxide (NO) and peroxynitrite formation. 2. Urethane-anaesthetized rats were exposed to heat stress (ambient temperature 43 degrees C) to induce heat stroke. Control rats were exposed to 24 degrees C. Mean arterial pressure and renal blood flow after the onset of heat stroke were significantly lower in heat stroke rats than in control rats. However, both colonic temperature and renal damage score were greater in heat stroke rats compared with control rats. Similarly, plasma NO, creatinine and blood urea nitrogen (BUN), as well as the renal immunoreactivity of iNOS and peroxynitrite, were significantly higher in heat stroke rats compared with their normothermic controls. 3. Pretreatment with SMS (1.2 g/day per rat for 7 consecutive days before the initiation of heat stress) significantly attenuated the heat stroke-induced arterial hypotension, hyperthermia, renal ischaemia and damage, the increased renal immunoreactivity of iNOS and peroxynitrite and the increased plasma levels of NO, creatinine and BUN. Pretreatment with SMS resulted in a prolongation of survival time in heat stroke. 4. The results of the present study suggest that SMS protects against renal ischaemic damage by reducing iNOS-dependent NO and peroxynitrite production during heat stroke.

Calreticulin expression in neuroblastoma--a novel independent prognostic factor

BACKGROUND

Calreticulin (CRT), an endoplasmic reticulum protein, has been reported to be essential for the differentiation of neuroblastoma (NB) cells, suggesting that CRT may affect the tumor behavior of neuroblastoma. The aim of this study was to evaluate the association of clinicopathologic factors and patient survival with the expression of CRT in patients with NB.

PATIENTS AND METHODS

Sixty-eight NBs were investigated by immunohistochemical staining against CRT, and were divided into positive and negative immunostaining groups. Correlations between calreticulin expression, various clinicopathologic and biologic factors, and patient survival were studied. In seven tumor samples, CRT mRNAs and proteins were evaluated with real-time PCR and western blot, respectively, and correlated with immunohistochemical findings.

RESULTS

Among 68 NBs, 32 (47.1%) showed positive CRT expression. Positive CRT immunostaining strongly correlated with differentiated histologies, as well as known favorable prognostic factors such as detected from mass screening, younger age (< or =1 year) at diagnosis and early clinical stages, but inversely correlated with MYCN amplification. Kaplan-Meier analysis revealed that NB patients with CRT expression did have better survival. Multivariate analysis demonstrated CRT expression to be an independent prognostic factor. Moreover, CRT expression also predicted better survival in patients with advanced-stage NBs, and its absence predicted poorer survival in patients whose tumor had no MYCN amplification. The amount of CRT mRNAs and proteins in NB tumor samples tested correlated well with the immunohistochemical expressions.

CONCLUSIONS

CRT expression correlates with the differentiation of NB and predicts favorable survival, thereby suggesting CRT to be a useful indicator for planning treatment of NB.

Inhibition of the dopamine system in rat amygdala attenuates the picrotoxin-induced locomoter hyperactivity and hypertension

The aim of the present study was to investigate whether picrotoxin-induced locomotor hyperactivity and hypertension can be inhibited by dopaminergic inhibition in rat amygdala. Locomotor activity was detected using a modularized infrared light matrix system in freely moving rats. In anaesthetized rats, blood pressure was measured while dopamine release was detected using in vivo voltammetry with carbon fibre electrodes. Systemic administration of picrotoxin (1-4 mg/kg) increased both locomotor activity (including horizontal motion, vertical motion and total distance travelled) and the number of turnings (both clockwise and anticlockwise), but inhibited postural freezing. The locomotor hyperactivity induced by systemic administration of picrotoxin was mimicked by direct injection of a small dose (1-3 micro g in 1.0 micro L) of picrotoxin into the amygdala. In vivo voltammetry data revealed that systemic administration of picrotoxin increased the release of dopamine in the amygdala of rat brain accompanied by hypertension. Local injection of kainic acid into the paramedian reticular nucleus (PRN) of the medulla oblongata decreased both the spontaneous release of dopamine in the amygdala and spontaneous levels of locomotor activity in rats. Furthermore, the picrotoxin-induced locomotor hyperactivity, hypertension and increased amygdaloid dopamine release were all suppressed following chemical stimulation of the PRN with kainic acid. Blockade of dopamine receptors with systemic or intra-amygdaloid injection of haloperidol (a dopamine receptor antagonist) significantly attenuated the picrotoxin-induced locomotor hyperactivity and hypertension. These results demonstrate that picrotoxin-induced hyperactivity and hypertension involve an increase in amygdaloid dopamine transmission that can be modulated by ascending projections from the PRN in the medulla oblongata.

Transcultural issues

Pharmacogenetics as a field of research is increasing the basis of knowledge on the use of psychotropics in different ethnic patient populations. This chapter summarizes current knowledge on the metabolism of anxiolytic agents with emphasis on pharmacogenetics and ethnic variations in drug responses.

Dopamine overload visualized in the basal ganglia of rabbit brain during heatstroke can be suppressed by hypothermia

The present study assesses the changes of dopamine levels in the basal ganglia (BG) of rabbit brain during heatstroke with or without hypothermia therapy. The dopamine levels were determined by using 6(F18) fluoro-L-dopa (FDOPA) positron emission tomography (PET) scan. Heatstroke was induced by exposing the anesthetized rabbits to a high blanket temperature (T(blanket)) of 45 degrees C. Hypothermia therapy was accomplished by decreasing T(blanket) from 45 to 16 degrees C. Regions-of-interest were carefully selected on the BG and cerebellum (C). The uptake ratio of FDOPA was defined as the mean counts per pixel from BG divided by the mean counts from C. BG/C ratios represent the dopamine levels of BG. The results showed that the values of mean arterial pressure (MAP) in heatstroke rabbits without hypothermia therapy were significantly lower than those in normothermic controls. However, BG/C FDOPA ratios were greater. Both the arterial hypotension and the increased BG/C FDOPA ratios observed during heatstroke were all reduced after hypothermia therapy. Our data demonstrate that the dopamine overload visualized in the BG of rabbit brain during heatstroke can be suppressed by hypothermia therapy.

The roles of vascular endothelial growth factor and angiopoietin-2 in the regression of pregnancy pyogenic granuloma

OBJECTIVES

The molecular mechanism for the regression of pregnancy pyogenic granuloma after parturition remains unclear. It has been proposed that, in the absence of vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) causes blood vessels to regress. Therefore, we investigated the roles of Ang-2 and VEGF in the regression of pregnancy pyogenic granuloma.

MATERIALS AND METHODS

The effects of tumor necrosis factor-alpha (TNF-alpha) on the transcription of Ang-2 were tested in endothelial cells by reverse transcriptase-polymerase chain reaction. A total of 15 specimens, including granulomas taken from five gravidas during pregnancy, five after parturition, and five from normal gingiva were compared by immunoblot assays for their relative expressions of Ang-1, Ang-2, Tie-2, VEGF, and beta-actin. Double staining, immunohistochemistry for Ang-2, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling for apoptotic cells, were used to evaluate their regression. Finally, a fibrin gel culture system was used to investigate whether the withdrawal of VEGF and addition of Ang-2 could cause newly grown microvessels to regress.

RESULTS

TNF-alpha upregulated the expression of Ang-2 in all endothelial cell types tested. The protein levels of Ang-2 and Tie-2 were highest in the granulomas in pregnancy, followed by those after parturition and normal gingiva, while Ang-1 and beta-actin exhibited no significant differences. The amount of VEGF was high in the granulomas in pregnancy and almost undetectable after parturition. Double staining on granulomas after parturition revealed more apoptotic cells and less Ang-2 than did those in pregnancy. In the fibrin gel assay, VEGF alone or in combination with Ang-2 could protect microvessels from apoptosis, while Ang-2 alone had no effect.

CONCLUSIONS

Our findings suggest that a lack of VEGF is associated with apoptosis of endothelial cells and regression of granuloma. The roles of Ang-2 require additional study.

Protective effects of alpha-tocopherol and mannitol in both circulatory shock and cerebral ischaemia injury in rat heatstroke

1. There is evidence that hydroxyl radicals are accumulated and oxidative stress is produced in multiple organs, including the brain, of rats with heat stroke. Herein, we investigated the effect on heat stroke-induced circulatory shock and cerebral ischaemic injury of two free radical scavengers, namely mannitol and alpha-tocopherol. 2. Urethane-anaesthetized rats were exposed to heat stress (ambient temperature 42 degrees C) to induce heat stroke. Control rats were exposed to 24 degrees C. Mean arterial pressure and cerebral blood flow after the onset of heat stroke were significantly lower in heat stroke rats than in control rats. However, cerebral free radicals, lipid peroxidation and the neuronal damage score were greater in heat stroke rats compared with control rats. Similarly, plasma cytokines, including tumour necrosis factor-alpha, interleukin (IL)-1beta and IL-6, were significantly higher in heat stroke rats compared with their normothermic controls. 3. Pretreatment with alpha-tocopherol (20 mg/kg, i.v.) or mannitol (10%, i.v.) 30 min before the onset of heat exposure significantly attenuated heat stroke-induced arterial hypotension, cerebral ischaemia and neuronal damage, the increased free radical formation and lipid peroxidation in the brain and the increased plasma levels of cytokines. Pretreatment with alpha-tocopherol or mannitol resulted in a prolongation of survival time in heat stroke. 4. These results demonstrate that although pretreatment with alpha-tocopherol and mannitol does not prevent the heat stroke syndrome entirely, an attenuation of the syndrome is observed.

Magnolol protects against cerebral ischaemic injury of rat heatstroke

1. Free radicals mediate cerebral ischaemic injury associated with heatstroke. Magnolol, an active component of Magnolia officinalis, is 1000-fold more potent than alpha-tocopherol in inhibiting lipid peroxidation in rat mitochondria. The aim of the present study was to ascertain whether magnolol attenuated cerebral ischaemic injury and free radical formation associated with heatstroke. 2. Urethane-anaesthetized rats were exposed to heat stress (ambient temperature 42 degrees C) to induce heatstroke. Controlled rats were exposed to 24 degrees C. Mean arterial pressure, cerebral perfusion pressure and cerebral blood flow after the onset of heatstroke were all significantly lower than in control rats. However, colonic temperature, intracranial pressure, heart rate, cerebral free radicals, lipid peroxidation and the neuronal damage score were greater after the onset of heatstroke. 3. Magnolol (20 or 40 mg/kg, i.v.) significantly attenuated the heatstroke-induced hyperthermia, arterial hypotension, intracranial hypertension, cerebral ischaemia and neuronal damage and increased free radical formation and lipid peroxidation in the brain. The extracellular concentrations of ischaemic (e.g. glutamate and lactate/pyruvate ratio) and damage (e.g. glycerol) markers in the corpus striatum were increased after the onset of heatstroke. Magnolol significantly attenuated the increase in striatal ischaemia and damage markers associated with heatstroke. 4. Thus, it appears that magnolol has impressive effects against heatstroke reactions.

Generation of HLA-C-specific cytotoxic T cells in association with marrow graft rejection: analysis of alloimmunity by T-cell cloning and testing of T-cell-receptor rearrangements

Peripheral blood mononuclear cells from a patient who rejected a T-cell-depleted marrow graft showed spontaneous cytotoxic activity specific for HLA-Cw4 and HLA-B35 alloantigens of the donor. T-cell-receptor complementarity-determining region 3 length distributions in a blood sample obtained at the time of rejection generally showed distortions in only 1 or 2 peaks, indicating that recipient T cells with a broad repertoire of antigen receptors survived the pretransplantation conditioning regimen. An HLA-Cw4-specific, CD8 T-cell clone was recovered from a blood sample after rejection. The T-cell-receptor-B gene rearrangement expressed by this clone was not readily detectable in other blood samples drawn before or after the transplantation, indicating that this clone was only 1 of many recipient-derived T cells that recognized HLA alloantigens of the donor. These results demonstrate the role of the HLA-C locus in T-cell-mediated alloimmune responses and add to emerging evidence that indicates the need to evaluate HLA-C compatibility in selecting hematopoietic stem cell donors for patients who have an increased risk of rejection.

Association of TLR4 mutations and the risk for acute GVHD after HLA-matched-sibling hematopoietic stem cell transplantation

Lipopolysaccharide (LPS) has been implicated in the pathogenesis of graft-versus-host disease (GVHD). The toll-like receptor (TLR)-4 has been recently identified as a major receptor for LPS. Mutations of TLR4 have been associated with LPS hyporesponsiveness. We hypothesized that TLR4 mutations reduce the risk of acute GVHD in allogeneic marrow transplant recipients. In a preliminary study to determine the frequency of TLR4 mutations and their possible association with GVHD, we tested 237 patients and their HLA-identical sibling donors for 2 TLR4 polymorphisms. All patients received methotrexate and cyclosporine for GVHD prophylaxis. One or more mutants were detected in 10.8% of patients and 10.6% of donors. Multivariable logistic regression models were used to analyze the association between TLR4 mutations and probability (1-sided) of GVHD. The odds ratio (adjusted for advanced disease, total body irradiation dose, and patient age) for development of grades II to IV GVHD when a mutation was present in the recipient was 0.63 (95% confidence interval [CI], 0.25-1.60; P = .16). When a mutation was present in the donor, the adjusted odds ratio was 0.88 (95% CI, 0.36-2.17; P = .40). When a mutation was present in both recipient and donor, the odds ratio was 0.72 (95% CI, 0.22-2.32; P = .29). Among 24 patients with TLR4 mutations in either donor or recipient, 4 (16.7%) developed gram-negative bacteremia. Among 213 patients without mutations, 14 (6.6%) developed gram-negative bacteremia (P = .09). The data indicate that a reduced risk of acute GVHD is associated with TLR4 mutations and that TLR4 mutations may increase the risk for gram-negative bacteremia. However, these associations are not statistically significant in recipients of HLA-matched sibling marrow transplants who are prophylactically treated for infections and GVHD. A much larger study population would be needed to confirm the role of LPS in the pathogenesis of GVHD in humans.

Cyclooxygenase-2 inducing Mcl-1-dependent survival mechanism in human lung adenocarcinoma CL1.0 cells. Involvement of phosphatidylinositol 3-kinase/Akt pathway

Cyclooxygenase 2 (COX-2) has been reported to be commonly expressed in advanced stages of human lung adenocarcinoma. In this study, the COX-2 constitutive expression vector was transfected into a human lung adenocarcinoma cell line CL1.0 and several clones were obtained which stably expressed COX-2. These COX-2-overexpressed clones demonstrated remarkable resistance to apoptosis induced by Ultraviolet B (UVB) irradiation, vinblastine B (VBL) cell lymphoma-2 (Bcl-2), or other anti-cancer drugs. To understand how COX-2 prevents apoptosis, the investigators examined the expression level of Bcl-2 family members. Mcl-1, but not other Bcl-2 members, was significantly up-regulated by COX-2 transfection or prostaglandin E(2) (PGE(2)) treatment. Treatment of COX-2-overexpressed cells (cox-2/cl.4) with two specific COX-2 inhibitors, NS-398 and celecoxib, caused an effective reduction of the increased level of Mcl-1. These data suggest that the expression level of Mcl-1 is tightly regulated by COX-2. Moreover, transfection of cox-2/cl.4 cells with antisense Mcl-1 enhanced apoptosis induced by UVB irradiation, revealing that Mcl-1 plays a crucial role in cell survival activity mediated by COX-2. Furthermore, COX-2 transfection or PGE(2) treatment evidently activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Inhibition of the PI3K pathway by LY294002 or wortmannin effectively attenuated the increased level of Mcl-1 induced by COX-2 or PGE(2). Blocking the PI3K activity with a dominant-negative vector, DN-p85, also greatly diminished the level of Mcl-1 and enhanced UVB-elicited cell death in cells transfected by COX-2. In a similar way, LY294002 inhibited cell survival and Mcl-1 level in PGE(2)-treated CL1.0 cells. These findings suggest that COX-2 promotes cell survival by up-regulating the level of Mcl-1 by activating the PI3K/Akt-dependent pathway.

Involvement of brain glutamate release in pyrogenic fever

Whether the glutamate release in the organum vasculosum laminae terminalis (OVLT) is attributable to genesis of a pyrogenic fever is unclear. The lack of information led us to evaluate the changes in glutamate concentrations of OVLT during the fever induced by staphylococcal enterotoxin A (SEA) in unanesthetized rabbits. Both the OVLT concentrations of glutamate and the colonic temperatures were simultaneously monitored during systemic injection of SEA, MK801 (an N-methyl-D-aspartate (NMDA) receptor channel blocker), ketamine (an NMDA receptor channel blocker), or normal saline. The extracellular dialysates in the brain were collected using a microdialysis probe previously placed in the OVLT region. The concentrations of glutamate in the microdialysates were measured by a high-pressure liquid chromatography in combination with a fluorescence detector. Systemic administration of SEA (30 ng x kg(-1) I.V.) increased both the concentrations of glutamate in the OVLT and the colonic temperatures. Glutamate appeared to rise slightly earlier than body temperature. Pretreatment or posttreatment with MK801 or ketamine significantly attenuated the SEA-induced augmenting glutamate release in the OVLT and fever in rabbits. The suppression of glutamate release appeared to start slightly earlier than temperature decline. In addition, the SEA-induced fever could be mimicked by direct injection of glutamate or SEA into the OVLT area. The fever induced by intra-OVLT injection of SEA or glutamate was significantly attenuated by pretreatment with an intra-OVLT dose of MK801 (5 microg) or ketamine (10 microg). The results suggest that glutamatergic pathways in the OVLT region are in pyrogenic fever genesis.

IL-6 inhibits apoptosis and retains oxidative DNA lesions in human gastric cancer AGS cells through up-regulation of anti-apoptotic gene mcl-1

Apoptosis plays a critical role in maintaining genomic integrity by selectively removing the most heavily damaged cells from the population. Reactive oxygen species (ROS) and certain inflammatory cytokines are always elevated during the human carcinogenic process. However, the biological significance of the interplay between ROS and inflammatory cytokine remains elusive. This study demonstrates that interleukin-6 (IL-6) effectively protects gastric cancer cells from the apoptosis induced by hydrogen peroxide (H(2)O(2)). The cell death signaling JNK pathway elicited by H(2)O(2) is also inhibited by IL-6. We further found that Mcl-1, but not other Bcl-2 family members, was up-regulated by IL-6, by a substantial level over 24 h. We further transfected a mcl-1 expression vector, pCMV-mcl-1, into the AGS cells, and successfully obtained several mcl-1-overexpressing clones. Flow cytometric analysis shows that these mcl-1-overexpressing AGS cells are more resistant to the apoptosis induced by H(2)O(2) when compared with the neo control AGS cells. Consistently, the activation of the JNK pathway induced by H(2)O(2) is also blocked in mcl-1-overexpressed cells. These results indicate that the anti-apoptotic effect of IL-6 is, at least in part, due to the up-regulation of mcl-1. To our surprise, either IL-6 exposure or mcl-1 overexpression fails to reduce the level of intracellular peroxides in the AGS cells triggered by H(2)O(2). This study also determined the level of 8-hydroxydeoxyguanosine (8-OH-dGua), an indicator for oxidative DNA lesions in IL-6-treated or mcl-1-overexpressed AGS cells after treatment with H(2)O(2). Notably, our results indicate that a majority of the 8-OH-dGua is efficiently removed in the AGS cells without IL-6 treatment, whereas only approximately 50% of the 8-OH-dGua was repaired in the IL-6-treated AGS cells after 24 h. Similarly, approximately 60-70% of the 8-OH-dGua also failed to repair and was retained in the genomic DNA of the mcl-1 transfectants. Results in this study provide a novel mechanism by which up-regulation of the Mcl-1 protein by IL-6 may enhance the susceptibility to H(2)O(2)-induced oxidative DNA lesions by overriding apoptosis.

The hypothermic effects of dl-tetrahydropalmatine in rats

Systemic administration of dl-tetrahydropalmatine (THP; 10-50 mg x kg(-1) intraperitoneally) produced a proportional decrease in both colonic temperature and release of hypothalamic serotonin (5-hydroxytryptamine (5-HT)) in rats at room temperature. The hypothermia was brought about by cutaneous vasodilation and decreased metabolism. The THP- induced hypothermia was significantly attenuated in rats with brain 5-HT depletion produced by control injection of 5,7-dihydroxytryptamine or in rats with 5-HT2A receptor activation produced by 1-(2,5-dimethoxy-4-iodophenyl) -2-aminopropane, or in rats with 5-HT1A receptor antagonist produced by (-)-pindolol. The results suggest involvement of serotoninergic antagonism in the THP-induced hypothermia in rats

Improving efficacy of antifungal therapy by polymerase chain reaction-based strategy among febrile patients with neutropenia and cancer

Early detection of fungal infections in and corresponding early treatment of febrile patients with neutropenia and cancer have been important issues and continue to be major challenges for clinicians. The use of nested PCR to make therapeutic decisions was studied. Sequential blood samples obtained from 42 patients with neutropenia and cancer were tested by nested PCR and culture. Instead of the empirical antifungal therapy strategy, amphotericin B treatment was initiated only for patients who had 2 consecutive positive results by nested PCR. A reduced mortality rate was observed for febrile patients with neutropenia and cancer who had fungal infections. Thus, this strategy, combined with the nested PCR for early detection of fungal infection in febrile patients with neutropenia, may be used as a guideline for antifungal therapy.

Alanyl-glutamine enriched total parenteral nutrition improves local, systemic, and remote organ responses to intraperitoneal bacterial challenge

BACKGROUND

Standard total parenteral nutrition (STD-TPN) may diminish host defense against infection. Glutamine (Gln) is suggested to enhance host immunity. This study investigated the effects of antecedent alanyl-glutamine enriched TPN (Ala-Gln-TPN) on host responses to intraperitoneal bacterial challenge compared with STD-TPN.

METHODS

Rats were divided into STD-TPN and Ala-Gln-TPN groups. They received isocaloric and isonitrogenous nutrition for 7 days and were challenged intraperitoneally with E. coli. Rats were killed before (0 hour) challenge and at 2 and 6 hours after challenge. Bacterial numbers in peritoneal lavage fluid (PLF), liver, spleen, and blood were determined. Tumor necrosis factor-alpha (TNF), interleukin (IL)-8, and interferon-gamma (IFN) in plasma and PLF were measured. Hepatic TNF, splenic TNF, and splenic IFN levels were determined.

RESULTS

The numbers of E. coli in systemic blood at 2 hours after intraperitoneal bacterial challenge were significantly lower in the Ala-Gln-TPN than in STD-TPN group. E. coli numbers in blood significantly correlated with those in the liver. The Ala-Gln-TPN also resulted in significantly higher PLF and hepatic TNF levels, higher splenic IFN levels, and lower plasma IL-8 levels at 6 hours after challenge compared with the STD-TPN.

CONCLUSIONS

Antecedent Ala-Gln enriched TPN enhance local, systemic, and remote organ immune responses to intraperitoneal bacterial challenge. Ala-Gln-TPN may enhance host defense and be more beneficial than standard TPN in sepsis.

Stimulatory effect of phenylephrine on the secretion of beta-endorphin from rat adrenal medulla in vitro

In an attempt to investigate the role of alpha1-adrenoceptors in the regulation of opioid secretion from adrenal gland, phenylephrine was employed to investigate the effect on secretion of beta-endorphin-like immunoreactivity (BER) from adrenal medulla of rat in vitro. Phenylephrine enhanced the BER from isolated adrenal medulla in a concentration-dependent manner and this action was abolished by the antagonists of alpha1-adrenoceptors, prazosin and tamsulosin. Investigations of signal pathway further support that an activation of alpha1-adrenoceptors is responsible for the stimulatory effect of phenylephrine on BER secretion from adrenal medulla. In the presence of U73312, the specific inhibitor of phospholipase C (PLC), phenylephrine-induced change of BER was reduced in a concentration-dependent manner but it was not affected by U73343, the negative control of U73312. Moreover, chelerythrine and GF 109203X diminished the action of phenylephrine at concentration sufficient to inhibit protein kinase C (PKC). In conclusion, our results suggest that an activation of alpha1-adrenoceptors in adrenal medulla by phenylephrine may enhance the secretion of opioids from adrenal gland of rat via signals of PLC-PKC pathway.

Genomics of unrelated-donor hematopoietic cell transplantation

Unrelated-donor hematopoietic cell transplantation is a proven curative modality for hematologic malignancies. The success of unrelated-donor transplantation has been achieved through a better understanding of the immunobiology of the HLA system and through more precise and comprehensive matching of donors and recipients. The extensive polymorphism of HLA genes confers important biological implications affecting engraftment, graft-versus-host disease and overall survival. Although more-complete HLA identity of the donor and recipient is associated with optimal transplant outcome, new information suggests that not every HLA disparity is functionally relevant. Future advances in unrelated-donor transplantation must include the identification of tolerable HLA mismatches, so that more patients may benefit from this therapeutic modality. Furthermore, the role of cytokine-gene polymorphisms and minor histocompatibility genes in transplant outcome requires investigation. Delineation of the function of these markers as transplantation determinants may provide alternative means for optimizing the results of hematopoietic cell transplantation.

Effects of glutamine-supplemented total parenteral nutrition on cytokine production and T cell population in septic rats

BACKGROUND

This study was designed to investigate the effects of total parenteral nutrition (TPN) enriched with glutamine (GLN) on in vivo cytokine production and cellular immune response in early and late septic stages of rats.

METHODS

Male Wistar rats were divided into 2 experimental groups and received TPN solution at an energy level of 270 kcal/kg body weight. The TPN solutions were isonitrogenous and identical in nutrients composition except for differences in amino acid content. One group received 2% GLN, whereas the other group received glycine (Gly) instead. TPN was maintained for 5 or 6 days according to the sacrifice schedule of the rats. On day 5, sepsis was induced by cecal ligation and puncture (CLP). Respective groups of rats were sacrificed 2, 4, 6, and 24 hours after CLP.

RESULTS

Sepsis resulted in a negative nitrogen balance in both groups, and nitrogen loss was significantly lower in the GLN than the Gly group. Interleukin (IL)-2 and interferon (IFN)-gamma in most of the samples collected at various time points were not detectable in plasma or peritoneal lavage fluid. No differences in plasma IL-6 and TNF-alpha concentrations were observed between the GLN and Gly groups. Also, there were no significant differences in IL-1beta, IL-6, and TNF-alpha concentrations in peritoneal lavage fluid between the 2 groups at various time points. The CD4+/CD8+ ratio was significantly higher in the GLN group than in the Gly group only at 4 hours after CLP, and no difference was observed at 24 hours after CLP.

CONCLUSIONS

TPN preinfused with a GLN-supplemented solution had a beneficial effect in ameliorating the extent of negative nitrogen balance in septic rats. However, parenterally administered GLN did not reduce the production of inflammatory mediators systemically or at the site of injury, and the influence on enhancing cellular immunity was not obvious.

Low mutational burden of individual acquired mitochondrial DNA mutations in brain

Neurons may be particularly susceptible to oxidative damage, which has been proposed to induce somatic mutations, particularly in mitochondrial DNA (mtDNA). Therefore, acquired mtDNA mutations might preferentially accumulate in the brain and could play a role in aging and neurodegenerative disorders. Recently, a somatic T to G mtDNA mutation at noncoding nucleotide position 414 was reported in fibroblasts specifically from elderly subjects, with mutational burdens of up to 50%. We screened for this mutation in brain-derived mtDNA from 8 Alzheimer's disease patients, 27 Parkinson's disease patients, 4 multiple system atrophy patients, and 44 controls using up to three RFLP analyses. A total of 73 of these subjects were over the age of 65. The 414 mutation was absent in all cases. Next, individual mtDNA fragments from 6 elderly subjects were cloned, and a total of 70 clones were sequenced. The 414 mutation was absent in all clones, though occasional sequence variations were identified at other sites in single clones. The 414 mutation also was absent in blood (n = 6) and fibroblasts (n = 11) from elderly subjects. Our data suggest that it is rare for any one particular acquired mtDNA mutation to reach levels in the brain that are functionally significant. This does not exclude the possibility that the cumulative burden of multiple, individually rare, acquired mutations impairs mitochondrial function.

The protective effect of hypervolemic hemodilution in experimental heatstroke

The authors tested the hypothesis in a rat model that hypervolemic hemodilution during heatstroke affected the mean arterial pressure (MAP), striatal dopamine (DA) release, and local cerebral blood flow and neuronal damage score in different brain structures. The heatstroke was induced by exposing the urethane-anesthetized rats to an ambient temperature of 42 degrees C. Hypervolemic hemodilution was produced by intravenous administration of 10% human albumin. Relative and absolute blood flow in the corpus striatum were determined using the laser Doppler flowmetry and the autoradiography diffusible tracer technique, respectively. The DA release in the striatum was estimated using the in vivo microdialysis technique. After onset of heatstroke, animals with hypervolemic state alone, produced by saline or heparinized blood injection, displayed higher values of DA release, as well as neuronal damage score in the striatum, hypothalamus, or cortex, but lower values of MAP and blood flow in the striatum, hypothalamus, or cortex compared to normothermic controls. However, the heatstroke-induced arterial hypotension, cerebral ischemia, increased striatal DA overload, and increased neuronal damage score were attenuated by induction of both hypervolemic and hemodilution state with 10% albumin either before or after the onset of heatstroke. In addition, constant infusions of a vasopressor agent phenylephrine (2 microg kg(-1) min(-1)) after the onset of heatstroke failed to maintain appropriate levels of MAP and resulted in no protection against heatstroke. Thus, it appears that the observed benefit of the 10% albumin is secondary to hemodilution and/or maintenance of MAP.

Ex vivo fluorescence microscopy provides simple and accurate assessment of neutrophil-endothelial adhesion in the rat lung

Neutrophil adhesion to the pulmonary endothelium is prerequisite to neutrophil transmigration and activation, both of which may lead to lung injury. A simple method to evaluate neutrophil adherence in the lung would be useful for developing new strategies for neutrophil-mediated lung injury. The purpose was to establish a simple method to evaluate neutrophil adhesion in the lung using ex vivo fluorescence microscopy. Rats were anesthetized, and the right jugular veins were catheterized. Neutrophils were isolated from another set of rats and labeled with 5,(6)-carboxyfluorescein diacetate. Animals were killed 120 s after a 1 x 10(6) labeled neutrophil injection. The pulmonary labeled neutrophil number was counted under a fluorescence microscope. In the first experiment, rats were given 0, 20, 200, or 2000 microg/kg lipopolysaccharide (LPS) i.p. At 4 h after challenge, the pulmonary labeled neutrophil number was determined. Kinetic studies were also performed at 0, 1, 4, and 8 h after 200 microg/kg LPS. Finally, anti-ICAM-1 Ab was injected i.v. before LPS 200 microg/kg, and the labeled neutrophil number in the lung was determined at 4 h. The number of pulmonary labeled neutrophils was higher after LPS 200 or 2000 microg/kg than after the other doses. The pulmonary labeled neutrophil number was increased at 4 h compared with the other time points. ICAM-1 blocking normalized the pulmonary labeled neutrophil number in the LPS group. In conclusion, our method seems to reflect ICAM-1-mediated neutrophil adherence to the endothelium in the present setting. This simple technique may be useful for evaluating neutrophil adhesion.

Immunohistochemical evaluation of cadherin and catenin expression in early gastric carcinomas: correlation with clinicopathologic characteristics and Helicobacter pylori infection

Dysfunction of E-cadherin and catenin has been linked to invasiveness and differentiation of tumors. This study aimed to characterize the expression of cadherins and catenins in early gastric carcinoma and their relationship to clinicopathologic characteristics and Helicobacter pylori infection. E-cadherin and alpha-, beta- and gamma-catenins were strongly expressed in normal epithelium but abnormal immunoreactivity of at least one of these four proteins was noted in 48 (90.6%) of 53 early gastric carcinomas. Only 5 cases with intestinal-type tumors had intact expression of E-cadherin and alpha-, beta-, and gamma-catenins. Abnormal immunoreactivity in the tumor tissue was observed in 18 patients (34.0%) for E-cadherin, in 35 (66.0%) for alpha-catenin, in 20 (37.7%) for beta-catenin, and in 37 (69.8%) for gamma-catenin. In diffuse-type tumors, abnormal expression of E-cadherin (60.9 vs. 13.3%, p < 0.0005), alpha-catenin (82.6 vs. 53.3%, p < 0.05) and gamma-catenin (91.3 vs. 53.3%, p < 0.005) was more frequent than in the intestinal type. Ten tumors with lymph node metastasis showed a relatively higher frequency of abnormal expression of E-cadherin (70 vs. 25.6%, p < 0.05) but a lower frequency of abnormal expression of beta-catenin (10 vs. 44.1%, p = 0.07) than those without metastasis. No significant association was found between cadherin/catenin expression and the depth of invasion or the H. pylori status. It was concluded that abnormal expression of E-cadherin and the catenin-mediated cell-cell adhesion system occurs frequently in early gastric carcinogenesis and may play an important role in the genesis of histologic differentiation and in the mode of metastasis of early gastric carcinomas.

DL-Tetrahydropalmatine may act through inhibition of amygdaloid release of dopamine to inhibit an epileptic attack in rats

DL-Tetrahydropalmatine (THP), an active component isolated from corydalis (a Chinese herbal medicine), possesses analgesic effects. Systemic administration of picrotoxin (3-4 mg/kg) produced increases of locomotion (including horizontal motion, vertical motion, and total distance traveled), elevations of turnings (including both clockwise and anticlockwise), and inhibition of postural freezing in freely moving rats, and increases of amygdaloidal release of dopamine in anesthetizes rats. All the afore-mentioned activity measures induced by picrotoxin were suppressed following THP pretreatment. The results indicate that THP may act through inhibition of amygdaloid dopamine release to inhibit an epileptic attack.

Loss of plasma glucose lowering response to cold stress in opioid mu-receptor knock-out diabetic mice

Opioid mu-receptor plays an important role in the regulation of glucose homeostasis in diabetic rats lacking insulin. Opioid mu-receptor knockout mice were employed to identify the essential role of this receptor in the present study. Western blotting analysis characterized the deletion of opioid mu-receptor in liver of knockout mice as compared to that of normal (wild-type) mice. We found that the plasma glucose concentration of diabetic mice induced by intraperitoneal injection of streptozotocin was markedly decreased after exposure to cold-stress in a cold room for 1 h. However, this plasma glucose lowering response to cold-stress was disappeared in diabetic mice lacking opioid mu-receptor. The important role of opioid mu-receptor in the plasma glucose lowering response to cold stress can thus be considered. Moreover, bilateral adrenalectomy abolished this plasma glucose lowering response to cold stress in diabetic mice with opioid mu-receptor, as compared to the shamed-operated animals. Therefore, activation of opioid mu-receptor by opioid from adrenal gland appears to be responsible for the plasma glucose lowering response to cold-stress in diabetic mice with insulin deficiency.

Superoxide dismutase in hepatocellular carcinoma affects patient prognosis

BACKGROUND/AIMS

The free radicals play an important role in the pathogenesis of neoplastic transformation of the tissues. Superoxide dismutase is a metalloenzyme, protecting the cells from oxygen radical insult. The superoxide dismutase activity may therefore alter the cellular signaling pathways against the insults derived from oxidative stress especially in the tumor tissues. Therefore, it is considered that superoxide dismutase activity is crucial in affecting the survival of the cancer bearing patients. This study aims to investigate the level of superoxide dismutase activity in hepatocellular carcinoma tissues and correlate this with patients' survival after surgery for hepatocellular carcinoma.

METHODOLOGY

Thirty-six patients who had hepatectomy for hepatocellular carcinoma at the National Taiwan University Hospital from 1992 to 1993 were included in this study. Superoxide dismutase activity of the tumor tissues was determined. The results were correlated with the patients' survival. The patients were grouped based on their postoperative survival time. Those patients who were deceased less then one year after surgery were in group I. Group II included patients who survived more than one year but less than 3 years after operation. Group III patients survived more than 3 years but less than 5 years. Ten patients who survived longer than 5 years after surgical intervention were in group IV. Data were expressed as mean and analyzed with ANOVA.

RESULTS

The demographic and clinical information of patients, such as age, gender, plasma albumin, globulin, alpha-fetoprotein levels, and hepatitis markers were comparable among these groups. The superoxide dismutase levels in the hepatocellular carcinoma were significantly higher in group IV than the other three groups (P < 0.05). Similarly, the superoxide dismutase levels of the hepatocellular carcinoma tissues from group III patients were significantly greater than those tissues from patients of either group I or group II. Tumor superoxide dismutase levels tended to be higher in group II than in group I, although it did not reach a statistical significance.

CONCLUSIONS

Patients with higher superoxide dismutase levels in the hepatocellular carcinoma survived longer after hepatectomy. The superoxide dismutase levels of the tumor tissue may influence the malignancy and the outcome of the patients. It serves as prognostic factor for patients after hepatocellular carcinoma operation.

Mutation analysis and the correlation between genotype and phenotype of Arg778Leu mutation in chinese patients with Wilson disease

BACKGROUND

The defective gene (ATP7B) that causes Wilson disease (WD) codes for a putative copper-transporting P-type adenosine triphosphatase. After cloning of ATP7B, the spectrum of mutations and their clinical consequences have been investigated in patients with WD in different ethnic populations. However, the spectrum of mutations and the correlation of genotype-phenotype in the Chinese population have not been extensively studied.

OBJECTIVE

To investigate the characterization of mutations of ATP7B and the correlation between genotype and phenotype in the Chinese population.

METHODS

We studied 60 unrelated healthy Chinese and 65 unrelated Chinese families, including 84 patients with WD and 126 parents. Genomic DNA was prepared from peripheral blood leukocytes using a salt-precipitation method. Polymerase chain reaction single-strand conformation polymorphism and subsequent direct sequencing were used to identify the mutations and polymorphisms of ATP7B. Statistical analysis was performed using t test or chi(2) test.

RESULTS

We identified 18 mutations (7 novel) and 11 polymorphisms (3 novel). The novel mutations are -36C-->T, Trp650ter, Gln914ter, 2810delT, Thr935Met, Arg1041Pro, and Glu1173Lys. The novel polymorphisms are 1168A-->G (Ile390Val), 2785A-->G (Ile929Val), and 3316G-->A (Val1106Ile). Two mutations, Arg778Leu and Thr935Met, are relatively frequent, representing 37.7% and 10.0% of patients, respectively. To our knowledge, we are the first to report the correlation between the genotype and phenotype of Arg778Leu. The result shows that Arg778Leu homozygotes are associated with the early onset of WD with hepatic presentation.

CONCLUSIONS

The Arg778Leu and Thr935Met mutations are hot spots in the Chinese population. The features of mutations of ATP7B differ between the Chinese and Western ethnic populations. The Arg778Leu mutation has severe effects on the function of ATP7B. These findings are valuable for developing a fast and effective method to diagnose the presence of the WD gene.

Chemical constituents from Drypetes littoralis

Chemical investigation of Drypetes littoralis yielded three new tricyclic diterpenes, drypetenones A, B, and C (1--3), and one new xanthone (4). Spectral analyses and chemical correlations established the structures as 10S-12-hydroxy-11-methoxy-13-methylpodocarpa-1,5,8,11,13-pentaene-3,7-dione, (1), 10S-12-hydroxy-11-methoxy-13-methylpodocarpa-5,8,11,13-tetraene-3,7-dione (2), 10S-12-hydroxy-6,11-dimethoxy-13-methylpodocarpa-1,5,8,11,13-pentaene-3,7-dione (3), and 1-hydroxy-7-hydroxymethyl-6-methoxyxanthone (4). Complete (13)C NMR assignment of boehmenan D (5) is also made.

Single nucleotide polymorphisms in intron 2 of the human interleukin-1 receptor antagonist (IL-1Ra) gene: further definition of the IL-1 beta and IL-1Ra polymorphisms in North American Caucasians and Taiwanese Chinese

Previous studies have suggested that a variable number tandem repeat (VNTR) polymorphism in the second intron of the interleukin-1 receptor antagonist (IL-1Ra) gene and the single nucleotide polymorphisms at positions -511 and +3954 of the IL-1beta gene might be associated with increased risks of chronic inflammatory diseases, autoimmune diseases and gastric cancer. In the present study, IL-1beta and IL-1Ra genotypes were analyzed among Asians in Taiwan and Caucasians in North America. We identified a novel polymorphism with 3 nucleotide substitutions in the IL-1Ra VNTR 2-repeat allele. One of the substitutions corresponds with the fourth 3' end nucleotide of the reverse primer that is often used for analysis of the IL-1Ra-associated VNTR locus. Mismatching between this primer and the 2-repeat allele can cause misleading amplification results when stringent conditions are used for annealing. The estimated haplotype frequencies of the variant IL-1 genes were significantly different between Taiwanese and Caucasians. The frequency of the pro-inflammatory IL-1Ra 2-repeat allele was significantly lower in Taiwanese than in Caucasians. In contrast, the frequencies of the pro-inflammatory IL-1beta -511T allele and +3954C allele were significantly higher among Taiwanese compared with Caucasians.

A nitric oxide-dopamine link pathway in organum vasculosum laminae terminalis of rat brain exerts control over blood pressure

1. Experiments were carried out to explore the possible role played by the nitric oxide (NO) and dopamine (DA) system in the organum vasculosum laminae terminalis (OVLT) of rat brain in arterial pressure regulation. 2. Intracerebroventricular (ICV) administration of NO donors such as hydroxylamine or sodium nitroprusside (SNP) caused an up to 59 mmHg decrease in blood pressure (BP) and a decrease in DA release (measured by nafion coated carbon fibre electrodes in combination with voltammetry) in the OVLT. In contrast, ICV administration of N(G)-nitro-L-arginine methyl ester (L-NAME; a constitutive NO synthase inhibitor) or 7-nitroindazol (a neuronal NO synthase inhibitor) caused an up to 98 mmHg increase in BP and an increase in DA release in the OVLT. 3. Intra-OVLT injection of amphetamine (0.1 - 0.3 mg), SKF 38393 (a DA D(1) receptor agonist; 0.01 - 0.03 mg), or apomorphine (a DA D(2,3) receptor agonist; 0.01 - 0.03 mg) caused an increase in BP. On the other hand, intra-OVLT injection of SCH23390 (a DA D(1) receptor antagonist; 0.005 - 0.020 mg) or haloperidol (0.005 - 0.020 mg) caused a decrease in BP. 4. The pressor effects induced by intra-OVLT administration of L-NAME were attenuated by pretreatment with intra-OVLT injection of haloperidol, SCF23390, or 6-hydroxydopamine. In the contrast, the hydroxylamine-, 8-Br-cGMP- or SNP-induced depressor effects were attenuated by pretreatment with intra-OVLT injection of amphetamine, SKF 38393 or apomorphine. 5. The data suggest that activation of a NO-DA link pathway within the OVLT of rat brain exerts control over blood pressure.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

The involvement of PI 3-K/Akt-dependent up-regulation of Mcl-1 in the prevention of apoptosis of Hep3B cells by interleukin-6

Interleukin-6 (IL-6) is a pleitrophic cytokine that not only regulates growth and differentiation of many cell types, but also induces production of acute phase proteins (AAP) in hepatocytes. Our previous works have demonstrated that both PI 3-K/Akt and STAT3 pathways were concomitantly activated and cooperatively mediated the anti-apoptotic effect of IL-6. This investigation reports that IL-6 protected cells against apoptosis induced by a variety of agents including, TGF-beta, UV and retinoic acid (RA) in Hep3B cells, suggesting that IL-6 is a fundamental determinant of hepatic cell survival. Mcl-1, but not other Bcl-2 family members, was rapidly up-regulated by IL-6, with a peak (approximately 3-4-fold) appearing at 4 h. Transient transfection of cells with a mcl-1 antisense vector, resulting in a 50-60% reduction of the anti-apoptotic effect of IL-6, indicating that Mcl-1 is a downstream effector of IL-6. Which signaling pathway transduced by IL-6 responsible for the Mcl-1 up-regulation was further investigated. In Hep3B cells, the JAK/STAT3, ERK, and PI 3-K/Akt pathways were activated by IL-6 stimulation. Blocking JAK/STAT3 activation with a dominant-negative mutant STAT3F or a JAK inhibitor AG490 could not influence IL-6-mediated Mcl-1 up-regulation. Similarly, PD98059 treatment, a MEK specific inhibitor, also failed to inhibit Mcl-1 expression. However, the IL-6-induced Mcl-1 up-regulation was effectively attenuated in the presence of PI 3-K inhibitors, LY294002 and wortmannin. Expression of dominant-negative Akt, but not Etk, could abrogate the IL-6-induced increase of Mcl-1. In conclusion, our results suggest that the anti-apoptotic effect of IL-6 is mediated, at least in part, by Mcl-1 expression and that is mainly through the PI 3-K/ Akt-dependent pathway.

Clinicopathologic association of cyclooxygenase 1 and cyclooxygenase 2 expression in gastric adenocarcinoma

OBJECTIVE

To evaluate the association of clinicopathologic factors and prognostic value with the expression of cyclooxygenase 1 and 2 in patients with gastric adenocarcinoma.

SUMMARY BACKGROUND DATA

Epidemiologic studies have indicated that nonsteroidal antiinflammatory drugs reduce the risk of colon cancer by as much as 40% and also decrease the risk of gastric cancer. Recently, gastric cancer was found to express constitutive cyclooxygenase 1 and inducible cyclooxygenase 2 isoenzymes. Nonsteroidal antiinflammatories, which may function as cyclooxygenase inhibitors, inhibited the growth of gastric cancer cells. These two isoenzymes' expressions associated with traditional clinicopathologic factors have not been fully evaluated, and their prognostic value for determining survival in patients remains to be clarified.

METHODS

Seventy-one specimens resected from patients with gastric adenocarcinoma were investigated by immunohistochemical stain against cyclooxygenase 1 and 2. The 71 specimens were divided into stain-positive and stain-negative groups. Correlations between cyclooxygenase 1 and 2 expression, various clinicopathologic factors (including vascular invasion and Helicobacter pylori infection), and prognosis were studied.

RESULTS

The cyclooxygenase 2-positive group was significantly correlated with vascular invasion and H. pylori infection by univariate and multivariate analysis. In patients with cyclooxygenase 2-positive cancer, the prognosis was significantly poorer than in those with cyclooxygenase 2-negative cancer. However, multivariate analysis showed that vascular invasion, serosal invasion, and lymph node metastasis were independent prognostic factors for patients with gastric cancer, but cyclooxygenase 2 expression was not. There was no significant correlation between cyclooxygenase 1 expression and clinicopathologic factors and prognosis.

CONCLUSIONS

Upregulated cyclooxygenase 2 expression was associated with H. pylori infection in gastric cancer and was also strongly correlated with positive vascular invasion, which was an independent prognostic factor for poorer survival in this study. The usefulness of cyclooxygenase 2 inhibitors in the prevention or treatment of gastric cancer remains undetermined but deserves further investigation.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Differential expression of tissue-specific promoters by gene gun

BACKGROUND

Tissue-specific promoters are becoming increasingly important in light of their effects on gene expression in gene therapy experiments. The regulation of gene expression may be as important as the delivery of the gene itself.

OBJECTIVES

To determine the effects of the involucrin (INV), keratin 14 (K14) and cytomegalovirus (CMV) promoters on the expression of the reporter gene beta-galactosidase.

METHODS

In vivo, plasmid DNA was introduced to BALB/c mice by gene gun. Skin biopsies were taken after 24 h for histology and beta-galactosidase staining. In tissue culture cells, plasmid DNA was introduced by transient transfection to cell lines 293 (transformed primary human embryonal kidney cells), NIH 3T3 (immortalized mouse fibroblasts) and human keratinocytes. Reporter gene expression was assayed by histochemical staining and chemiluminescence.

RESULTS

The K14 and INV promoter constructs showed beta-galactosidase gene expression only in the epidermis, while the CMV promoter showed gene expression in both the dermis and epidermis. In cell culture, the INV and K14 promoter constructs demonstrated significant beta-galactosidase expression in human keratinocytes, but minimal expression in 293 and NIH 3T3 cell types. CMV promoter constructs demonstrated significant expression in all cell types.

CONCLUSIONS

Gene expression can be regulated by different promoters both in vivo and in cell culture. Based on the physiological expression of the different promoters, gene expression can be restricted to certain cell types, tissues and skin layers.

Glucocorticoids reduce interleukin-1 concentration and result in neuroprotective effects in rat heatstroke

In urethane-anaesthetized rats, we assessed the protective effects of glucocorticoids against heatstroke-induced arterial hypotension and ischaemic neuronal damage. Heatstroke was induced by exposing the animals to an ambient temperature of 42 C. The time at which both the mean arterial pressure (MAP) and local cerebral blood flow (CBF) in the striatum decreased from their peak levels was taken as the onset of heatstroke. Control rats were exposed to a temperature of 24 C. The values of MAP and CBF after heatstroke onset were all significantly lower than those in control rats. However, the neuronal damage score in the striatum and serum levels of interleukin-1beta (IL-1beta) were greater. Systemic pretreatment or treatment with an exogenous glucocorticoid, dexamethasone (4 mg or 6 mg kg-1, i.v.), reduced the heatstroke-induced arterial hypotension, serum IL-1beta levels, cerebral ischaemia and neuronal damage, and resulted in prolongation of the time to death (TTD; the interval between the onset of heat stress and cardiac arrest). Following bilateral adrenalectomy, MAP, CBF and TTD values were found to be significantly lower in the adrenalectomized (ADX) rats than in the sham-ADX rats after heat exposure. These changes were attenuated by dexamethasone. The data support the argument that glucocorticoids reduce the plasma IL-1beta concentration and may provide the neuroprotective effects observed in rat heatstroke.