Escape from cell-cell and cell-matrix adhesion dependence underscores disease progression in gastric cancer organoid models

OBJECTIVE

Cell-cell (CC) and cell-matrix (CM) adhesions are essential for epithelial cell survival, yet dissociation-induced apoptosis is frequently circumvented in malignant cells.

DESIGN

We explored CC and CM dependence in 58 gastric cancer (GC) organoids by withdrawing either ROCK inhibitor, matrix or both to evaluate their tumorigenic potential in terms of apoptosis resistance, correlation with oncogenic driver mutations and clinical behaviour. We performed mechanistic studies to determine the role of diffuse-type GC drivers: ARHGAP fusions, RHOA and CDH1, in modulating CC (CCi) or CM (CMi) adhesion independence.

RESULTS

97% of the tumour organoids were CMi, 66% were CCi and 52% were resistant to double withdrawal (CCi/CMi), while normal organoids were neither CMi nor CCi. Clinically, the CCi/CMi phenotype was associated with an infiltrative tumour edge and advanced tumour stage. Moreover, the CCi/CMi transcriptome signature was associated with poor patient survival when applied to three public GC datasets. CCi/CMi and CCi phenotypes were enriched in diffuse-type GC organoids, especially in those with oncogenic driver perturbation of RHO signalling via RHOA mutation or ARHGAP fusions. Inducible knockout of ARHGAP fusions in CCi/CMi tumour organoids led to resensitisation to CC/CM dissociation-induced apoptosis, upregulation of focal adhesion and tight junction genes, partial reversion to a more normal cystic phenotype and inhibited xenograft formation. Normal gastric organoids engineered with CDH1 or RHOA mutations became CMi or CCi, respectively.

CONCLUSIONS

The CCi/CMi phenotype has a critical role in malignant transformation and tumour progression, offering new mechanistic information on RHO-ROCK pathway inhibition that contributes to GC pathogenicity.

The Assessment of the Diagnostic Accuracy of Antigen-Detecting Rapid Diagnostic Test using Nasopharyngeal Swab Specimen in Detecting SARS-CoV-2 among Patients in a Private Hospital in Bulacan, Philippines

Introduction/Objective

Continuous progression of the COVID-19 outbreak prompted an expensive, limited, and slow-moving laboratory-based molecular testing capacity of the gold standard, Real-time Reverse Transcription- Polymerase Chain Reaction (rRT-PCR), in detecting SARS-CoV-2. The vital step in mitigation is utilizing an accurate diagnostic detection assay to deploy various preventive measures. Therefore, there is a need to evaluate an accessible, fast, and inexpensive point-of-care immunoassay, such as Antigen-detecting Rapid Diagnostic Tests (Ag- RDTs). Thus, the study aimed to assess the diagnostic accuracy of Ag-RDT in detecting SARS-CoV-2.

Methods/Case Report

A non-experimental, quantitative, and cross-sectional cohort study utilized 272 SARS-CoV-2 Ag-RDT with rRT-PCR confirmation collected from April 2021 to February 2022 in a private primary hospital laboratory database in Bulacan, Philippines. Diagnostic accuracy parameters of Ag-RDT included in the study are sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results (if a Case Study enter NA)

The overall sensitivity and specificity of Ag-RDT were 69.6% and 98.8%, respectively. Additionally, it exhibited a PPV of 84.2% and an NPV of 97.2%. With a hypothetical 1% prevalence, PPV and NPV were 36.8% and 99.7%. Meanwhile, PPV and NPV were 86.5% and 96.7% at 10% prevalence. High specificity denotes that positive Ag-RDT test results can be confidently considered in true SARS-CoV-2 infection, while low sensitivity entails that a negative result must be subjected to confirmatory tests. Furthermore, when prevalence increases, PPV increases while NPV decreases.

Conclusion

The study primarily encapsulated that the Ag-RDT cannot replace rRT-PCR in detecting SARS-CoV-2 infections. Despite its shortcomings, Ag-RDT is still valuable in areas with moderate-to-high disease prevalence and with limited access to confirmatory test due to its high predictive values and advantages. A larger number of positive results of rRT-PCR, evaluation of factors correlating to low sensitivity, and a prospective study are recommended for future studies.

Systemic proinflammatory-profibrotic response in aortic stenosis patients with diabetes and its relationship with myocardial remodeling and clinical outcome

Background

It is unclear whether and how diabetes mellitus may aggravate myocardial fibrosis and remodeling in the pressure-overloaded heart. We investigated the impact of diabetes on the prognosis of aortic stenosis (AS) patients and its underlying mechanisms using comprehensive noninvasive imaging studies and plasma proteomics.

Methods

Severe AS patients undergoing both echocardiography and cardiovascular magnetic resonance (CMR) (n=253 of which 66 had diabetes) comprised the imaging cohort. The degree of replacement and diffuse interstitial fibrosis by late gadolinium enhancement (LGE) and extracellular volume fraction (ECV) was quantified using CMR. Plasma samples were analyzed with the multiplex proximity extension assay for 92 proteomic biomarkers in a separate biomarker cohort of severe AS patients (n=100 of which 27 had diabetes).

Results

In the imaging cohort, diabetic patients were older (70.4±6.8 vs. 66.7±10.1 years) and had a higher prevalence of ischemic heart disease (28.8% vs. 9.1%), with more advanced ventricular diastolic dysfunction. On CMR, diabetic patients had increased replacement and diffuse interstitial fibrosis (LGE% 0.3 [0.0–1.6] versus 0.0 [0.0–0.5], p=0.009; ECV% 27.9 [25.7–30.1] versus 26.7 [24.9–28.5], p=0.025) (Figure 1).

Plasma proteomics analysis of the biomarker cohort revealed that 9 proteins (E-selectin, interleukin-1 receptor type 1, interleukin-1 receptor type 2, galectin-4, intercellular adhesion molecule 2, integrin beta-2, galectin-3, growth differentiation factor 15, and cathepsin D) are significantly elevated in diabetic AS patients (Figure 2). Pathway over-representation analyses of the plasma proteomics with Gene Ontology terms indicated that pathways related to inflammatory response and extracellular matrix components were enriched, suggesting that diabetes is associated with systemic effects that evoke proinflammatory and profibrotic response to the pressure-overloaded myocardium.

During follow-up (median 6.3 years [IQR 5.2–7.2]) of the imaging cohort, 232 patients received aortic valve replacement (AVR) with 53 unexpected heart failure admissions or death. Diabetes was a significant predictor of heart failure and death, independent of clinical covariates and AVR (hazard ratio 1.88, 95% confidence interval 1.06–3.31, p=0.030).

Conclusion

Plasma proteomic analyses indicate that diabetes potentiates the systemic proinflammatory and profibrotic milieu in AS patients. These systemic biological changes underlie the increase of myocardial fibrosis, diastolic dysfunction, and worse clinical outcomes in severe AS patients with concomitant diabetes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Research Foundation of Korea

Augmented risk of ischemic stroke in hypertrophic cardiomyopathy patients without documented atrial fibrillation

Background

Ischemic stroke is a common complication in patients with hypertrophic cardiomyopathy (HCM) (1). Although atrial fibrillation (AF) is a well-established risk factor for ischemic stroke in HCM, the risk of ischemic stroke in patients with HCM without documented AF is less recognized (1, 2). This study aimed to determine the risk of ischemic stroke and identify its risk factors in patients with HCM without documented AF.

Methods

This nationwide population-based cohort study used the Korean National Health Insurance database. After excluding patients with a prior history of AF, thromboembolic events, cancer, or the use of anticoagulants, we identified 8,328 HCM patients without documented AF and 1:2 propensity score-matched 16,656 non-HCM controls. The clinical outcome was an incident ischemic stroke.

Results

During a mean follow-up of approximately 6 years, ischemic stroke occurred in 328/8,328 (3.9%) patients with HCM and 443/16,656 (2.7%) controls. Among individuals who developed ischemic stroke, the proportion of AF concomitantly detected accounted for 26.5% (87/328) and 5.8% (26/443) in the HCM and control groups, respectively. The overall incidence of ischemic stroke was 0.716/100 person-years in the HCM group, which was significantly higher than that in the control group (0.44/100 person-years) (HR 1.643; 95% CI, 1.424–1.895; P<0.001, Figure 1). The subgroup analysis according to age, sex, and comorbidities (chronic heart failure, hypertension, dyslipidemia, and vascular disease) consistently demonstrated a higher risk of ischemic stroke in the HCM group (P for interaction >0.05). In the HCM group, age ≥65 years (adjusted hazard ratio [HR] 2.741; 95% confidence interval [CI], 2.156–3.486; P<0.001) and chronic heart failure (adjusted HR 1.748; 95% CI, 1.101–2.745; P=0.018) were independent risk factors for ischemic stroke. Overall incidence was 1.360/100 in patients with HCM aged ≥65 and 2.315/100 person-years years in those with chronic heart failure, respectively. Also, compared to controls aged <65 years and without CHF, adjusted HR for ischemic stroke was 4.756 (95% CI 3.807–5.867) in patients with HCM aged ≥65 years and 2.539 (95% CI 1.638–3.936) in those with CHF, respectively (Figure 2).

Conclusions

Patients with HCM without documented AF are at a higher risk of ischemic stroke than the propensity score-matched general population. Age ≥65 years and chronic heart failure are two strong independent risk factors for ischemic stroke in this population.

Funding Acknowledgement

Type of funding sources: None.

P1274 Early surgery versus watchful waiting in patients with moderate aortic stenosis and left ventricular systolic dysfunction

Background

Aortic stenosis (AS) induces significant pressure overload to the left ventricle (LV) and its burden may increase if there is concomitant LV systolic dysfunction. Severe AS with LV systolic dysfunction is a class I indication for aortic valve replacement (AVR) irrespective of symptoms, however, this recommendation is not well established in those with moderate AS and LV systolic dysfunction. In this study, we sought to investigate the clinical impact of surgical AVR among patients with moderate AS and LV systolic dysfunction.

Methods

From 2001 to 2017, we retrospectively but consecutively identified patients with moderate AS and LV systolic dysfunction from a single tertiary hospital. Moderate AS was defined as aortic valve area between 1.0 and 1.5cm2 and LV systolic dysfunction as LV ejection fraction less than 50%. The primary outcome was all-cause death and we additionally analyzed cardiac death as a secondary endpoint. The outcomes were compared between those who underwent early surgical AVR at the stage of moderate AS versus those who were followed without AVR at the outpatient clinic.

Results

Among a total of 257 patients with moderate AS and concomitant LV systolic dysfunction (70.0 ± 11.3 years, 63.4% of male), 34 patients received early AVR. Patients in the AVR group was younger than the observation group (64.2 ± 8.1 vs. 70.9 ± 11.5, respectively), and had a lower prevalence of hypertension and chronic kidney disease. During a mean of 3-year follow up, 112 patients (47.5%) died and the overall death rate was 15.367 per 100 person-year (PY). The AVR group showed a significantly lower rate of all-cause death than the observation group (5.241PY vs. 18.160PY, p-value = 0.002). After multivariable Cox proportional hazard regression adjusting for age, sex, comorbidities and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of all-cause death (hazard ratio [HR] 0.340, 95% confidence interval [CI] 0.117 - 0.985, p-value = 0.047). However, there was no risk reduction of cardiac death (HR 0.578 95% CI 0.150 - 2.231, p-value = 0.426).

Conclusions

In patients with moderate AS and LV systolic dysfunction, AVR reduces the risk of all-cause death. A prospective design study is warranted to confirm our findings in the near future.

Abstract P1274 Figure. Kaplan-Meier curves for deaths

P1603 Changes of cardiac function in cirrhotic patients after liver transplantation

Funding Acknowledgements

This study was supported by the grant of CJ healthcare 2016 research fund.

Background

Liver cirrhosis (LC) has been known to affect cardiovascular performance. Limited study have evaluated the alteration of myocardial function in patients with LC after liver transplantation (LT).

Purpose

The aim of study was to evaluate changes of cardiac function in patients with cirrhosis following LT using conventional and speckle-tracking echocardiography and late gadolinium enhancement (LGE) of cardiac magnetic resonance (MR).

Methods

Thirty-five patients with cirrhosis (mean age, 57.1 ± 9.0; male, 75%) who were listed for LT were prospectively enrolled. Patients underwent conventional, speckle-tracking echocardiography, and cardiac MR imaging with LGE. Echocardiography and cardiac MR were performed at pre and 1 year after LT. Cirrhotic patients were compared with normal control (n = 20, mean age, 65.0 ± 14.8; men, 11(55%)) and echocardiographic and cardiac MR data were compared pre and post LT.

Results

Conventional and speckle-tracking echocardiography and Cardiac MR imaging demonstrated hyperdynamic left ventricular (LV) function in patients with cirrhosis (LV ejection fraction (EF) with cardiac MR 67.8 ± 7.0% in LC vs. 63.4 ± 6.4% in control, P = 0.028; global longitudinal strain (GLS) -24.3 ± 2.6% in LC vs. -18.6 ± 2.2% in control, P < 0.001). There were no LGE in patients with cirrhosis and no significant differences in LV size, LV wall thickness, LV mass index, and diastolic function between cirrhotic patients and control group (all P > 0.1). Corrected QT interval (QTc) in electrocardiogram was prolonged in LC patients (P < 0.001). One-year after LT, LV end-diastolic diameter and LV end-diastolic volume significantly decreased (P = 0.016 and 0.022, respectively). Although LVEF showed no significant changes 1 year post-LT (P = 0.362), LV-GLS (from -24.7 ± 1.8% to -20.8 ± 3.4%, P < 0.001) significantly decreased. QTc interval also decreased 1 year after LT (from 470.4 ± 29.6msec to 428.2 ± 31.6msec, P = 0.001).

Conclusions

The present study demonstrated that cirrhotic patients showed hyperdynamic circulation and prolonged QTc interval compared with normal controls. After 1 year LT, LV size reduced and augmented LV function was normalized. Given that no LGE in cardiac MR and normalized GLS and QTc after LT, cardiac dysfunction in LC patients could be reversed by LT.

P1368 Effect of angiotensin receptor blocker in patients with moderate or severe aortic stenosis: a randomized controlled trial

Funding Acknowledgements

This study was supported by grants from Boryung Pharmacy Research Fund.

Background/Introduction: Pathophysiology of aortic stenosis (AS) and several previous studies suggested the potential role of angiotensin receptor blocker (ARB) in patients with AS.

Purpose

We aimed to investigate the effects of Fimasartan, an ARB, on exercise capacity and progression of AS in patients with moderate to severe AS.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled trial in 32 normotensive or controlled-hypertensive patients with moderate or severe AS. Study participants were randomized to Fimasartan 30 mg to 60 mg daily (n = 14) or placebo (n = 18) for 1 year, and underwent cardiopulmonary exercise test, 6-minute walk test, and echocardiography at 0, 6, and 12 months, with follow-up data available in 29 subjects.

Results

Significant reductions in blood pressures were observed in the Fimasartan group but not in the placebo group. Two of the 14 patients in the Fimasartan group withdrew the study due to mild symptoms probably related with the decreased blood pressure, and one patient decline the study protocol. After the 12-month treatment, the peak oxygen consumption (VO2; the primary outcome) in the Fimasartan group was significantly decreased (from 28.3 ± 5.9 to 25.4 ± 3.8 mL/min/kg, P = 0.021) but not in the placebo group (P for interaction = 0.046) (Figure 1A). The severity of AS showed a gradual progression in both groups, without inter-group differences (mean transaortic pressure; Fimasartan group, +4.0 ± 3.8 mmHg/year; placebo group, +5.3 ± 6.2 mmHg/year; P for interaction = 0.429) (Figure 1B). Parameters of left ventricular systolic and diastolic function did not change in both groups.

Conclusions

The use of ARB impaired exercise capacity in patients with moderate or severe AS, and did not prevent the progression of AS. However, due to the small number of participants, further studies are required to confirm these findings.

Abstract P1368 Figure.

P785 Left ventricular geometry and myocardial contractility modulate impact of statins on prognosis in patients with acute heart failure

Funding Acknowledgements

N/A

Background/Introduction: The benefit of statins in patients with heart failure (HF) remains controversial and the mechanism of action is largely speculative. We investigated whether survival benefit with statins differs according to left ventricular (LV) geometry and myocardial contractility in acute HF patients.

Methods

We enrolled 1792 acute HF patients receiving statins and 2296 patients not receiving statins admitted from 2009 to 2016. The LV and right ventricular (RV) global longitudinal strain (GLS) was assessed as a measure of myocardial contractility. Patients were classified into 2 groups based on ischemic etiology of HF and further divided into 4 subgroups according to the median values of LV-GLS or RV-GLS. The primary outcome was 5-year all-cause mortality. The study protocol was approved by the ethics committee at each institute and complied with the Declaration of Helsinki. The need for written informed consent was waived.

Results

During the 5-year follow-up, 1740 (40.4%) patients died and they had more unfavorable baseline characteristics. Statin therapy was significantly associated with improved survival in overall patients and in both groups with and without ischemic etiology (all p <0.001). Patients with concentric remodeling/hypertrophy and eccentric hypertrophy demonstrated survival benefit with statin therapy (P = 0.033, 0.004, and 0.008, respectively), while those with normal geometry did not (p = 0.123). In the non-ischemic HF group, survival benefit with statin therapy was confined to patients with low LV-GLS (p = 0.045) or those with low RV-GLS p = 0.003). On the contrary, in ischemic HF group, survival benefit with statin therapy was observed in all patients regardless of the values of LV-GLS or RV-GLS. Significant interactions were present between statin use and diabetes mellitus and IHD (p for interaction = 0.027 and 0.003, respectively) regarding mortality.

Conclusions

LV geometry and myocardial contractility may modulate the effects of statins in patients with acute HF. These echocardiographic measures can provide prognostic information to guide tailored statin treatment in this population. Our findings may also help to develop more well-designed prospective studies, in terms of a more homogenous study population, to confirm survival benefit with statin therapy.

Abstract P785 Figure. Multivariate Cox survival curves

Role of protein kinase C-η in cigarette smoke extract-induced apoptosis in MRC-5-cells

Cigarette smoke (CS) is a major risk factor for emphysema, which causes cell death in structural cells of the lung by mechanisms that are still not completely understood. We demonstrated previously that CS extract (CSE) induces caspase activation in MRC-5 human lung fibroblasts, activated protein kinase C-η (PKC-η), and translocated PKC-η from the cytosol to the membrane. The objective of this study was to investigate the involvement of PKC-η activation in a CSE-induced extrinsic apoptotic pathway. We determined that CSE increases expression of caspase 3 and 8 cleavage in MRC-5 cells and overexpression of PKC-η significantly increased expression of caspase 3 and 8 cleavage compared with control LacZ-infected cells. In contrast, dominant negative (dn) PKC-η inhibited apoptosis in MRC-5 cells exposed to CSE and decreased expression of caspase 3 and 8 compared with control cells. Exposure to 10% CSE for >8 h significantly increased lactate dehydrogenase release in PKC-η-infected cells compared with LacZ-infected cells. Additionally, PKC-η-infected cells had an increased number of Hoechst 33342 stained nuclei compared with LacZ-infected cells, while dn PKC-η-infected cells exhibited fewer morphological changes than LacZ-infected cells under phase-contrast microscopy. In conclusion, PKC-η activation plays a pro-apoptotic role in CSE-induced extrinsic apoptotic pathway in MRC-5 cells. These results suggest that modulation of PKC-η may be a useful tool for regulating the extrinsic apoptosis of MRC-5 cells by CSE and may have therapeutic potential in the treatment of CS-induced lung injury.

Whole-genome sequencing and comprehensive molecular profiling identify new driver mutations in gastric cancer

Gastric cancer is a heterogeneous disease with diverse molecular and histological subtypes. We performed whole-genome sequencing in 100 tumor-normal pairs, along with DNA copy number, gene expression and methylation profiling, for integrative genomic analysis. We found subtype-specific genetic and epigenetic perturbations and unique mutational signatures. We identified previously known (TP53, ARID1A and CDH1) and new (MUC6, CTNNA2, GLI3, RNF43 and others) significantly mutated driver genes. Specifically, we found RHOA mutations in 14.3% of diffuse-type tumors but not in intestinal-type tumors (P < 0.001). The mutations clustered in recurrent hotspots affecting functional domains and caused defective RHOA signaling, promoting escape from anoikis in organoid cultures. The top perturbed pathways in gastric cancer included adherens junction and focal adhesion, in which RHOA and other mutated genes we identified participate as key players. These findings illustrate a multidimensional and comprehensive genomic landscape that highlights the molecular complexity of gastric cancer and provides a road map to facilitate genome-guided personalized therapy.

Cord blood T cells retain early differentiation phenotype suitable for immunotherapy after TCR gene transfer to confer EBV specificity

Adoptive T cell therapy can be effective for Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease and melanoma. Transducing high-affinity TCR genes into T lymphocytes is an emerging method to improve potency and specificity of tumor-specific T cells. However, both methods necessitate in vitro lymphocyte proliferation, generating highly differentiated effector cells that display reduced survival and antitumor efficacy postinfusion. TCR-transduction of naive lymphocytes isolated from peripheral blood is reported to provide superior in vivo survival and function. We utilized cord blood (CB) lymphocytes, which comprise mainly naive cells, for transducing EBV-specific TCR. Comparable TCR expression was achieved in adult and CB cells, but the latter expressed an earlier differentiation profile. Further antigen-driven stimulation skewed adult lymphocytes to a late differentiation phenotype associated with immune exhaustion. In contrast, CB T cells retained a less differentiated phenotype after antigen stimulation, remaining CD57-negative but were still capable of antigen-specific polyfunctional cytokine expression and cytotoxicity in response to EBV antigen. CB T cells also retained longer telomeres and in general possessed higher telomerase activity indicative of greater proliferative potential. CB lymphocytes therefore have qualities indicating prolonged survival and effector function favorable to immunotherapy, especially in settings where donor lymphocytes are unavailable such as in solid organ and CB transplantation.

Cornulin, a marker of late epidermal differentiation, is down-regulated in eczema

BACKGROUND

Eczema is a common chronic inflammatory skin disorder which shows strong genetic predisposition. To identify new potential molecular determinants of the disease pathogenesis, we performed a gene expression study in an eczema mouse model. This analysis identified a marked down regulation of the cornulin gene (CRNN), a member of the epidermal differentiation complex, in the eczema-like skin. We then investigated CRNN as an eczema candidate gene and studied its polymorphism and the expression in the skin of eczema patients.

METHODS

An eczema-like phenotype was induced in mice by allergen (Der p2) patching. Gene expression analysis was performed with the subtractive suppression hybridization method and validated by real time PCR and the transmission disequilibrium test was used to test for genetic associations in 406 multiplex eczema families.

RESULTS

Der p 2 patched mice developed a localized eczema and a Th 2 skewed systemic response. Real time PCR analysis confirmed a down regulation of CRNN mRNA in eczema-like skin in the mouse model and in human eczema. The CRNN polymorphism rs941934 was significantly associated with atopic eczema in the genetic analysis (P = 0.006), though only as part of an extended haplotype including a known associated variant (2282del4) in the filaggrin gene.

CONCLUSIONS

CRNN mRNA expression is decreased in eczematous skin. Further studies are needed to verify whether the associated cornulin polymorphism contribute to the genetic susceptibility in eczema.

Thymol and related alkyl phenols activate the hTRPA1 channel

BACKGROUND AND PURPOSE

Thymol, a major component of thyme and oregano, has medical uses in oral care products as an astringent and antibiotic. Its distinctive sharp odour and pungent flavour are considered aversive properties. The molecular basis of these aversive properties is not well understood.

EXPERIMENTAL APPROACH

The ability of thymol to activate human transient receptor potential channel A1 (hTRPA1) expressed in stably transfected human embryonic kidney 293 (HEK293) cells was measured by membrane potential and calcium-sensitive dyes in a fluorescence-imaging plate reader (FLIPR) assay. Direct activation of hTRPA1 currents was measured by whole-cell voltage clamp recording. Intracellular calcium changes were measured using fura-2 dye. The FLIPR assay was also used to measure membrane potential changes elicited by thymol after pretreatment with camphor, a known TRPA1 inhibitor. The ability of related alkyl phenols to activate hTRPA1 was also determined.

KEY RESULTS

Thymol potently activated a membrane potential response and intracellular calcium increase in hTRPA1-expressing HEK293 cells in a concentration-dependent manner. Activation by thymol desensitized hTRPA1 to further exposure to thymol or the known ligand allyl isothiocyanate (AITC). The related phenols 2-tert-butyl-5-methylphenol, 2,6-diisopropylphenol (propofol) and carvacrol also activated hTRPA1. Phenols with less bulky carbon substitutions and lower logP values were less potent in general. The response to thymol was blocked by camphor.

CONCLUSIONS AND IMPLICATIONS

These results suggest a role for hTRPA1 activation in the reported pungent and aversive properties of some of these pharmaceutically important phenols.

Quantitative MRI reveals aging-associated T2 changes in mouse models of Alzheimer's disease

In this study, we used MRI to analyze quantitative parametric maps of transverse (T(2)) relaxation times in a longitudinal study of transgenic mice expressing mutant forms of amyloid precursor protein (APP), presenilin (PS1), or both (PS/APP), modeling aspects of Alzheimer's disease (AD). The main goal was to characterize the effects of progressive beta-amyloid accumulation and deposition on the biophysical environment of water and to investigate if these measurements would provide early indirect evidence of AD pathological changes in the brains of these mice. Our results demonstrate that at an early age before beta-amyloid deposition, only PS/APP mice show a reduced T(2) in the hippocampus and cortex compared with wild-type non-transgenic (NTg) controls, whereas a statistically significant within-group aging-associated decrease in T(2) values is seen in the cortex and hippocampus of all three transgenic genotypes (APP, PS/APP, and PS) but not in the NTg controls. In addition, for animals older than 12 months, we confirmed our previous report that only the two genotypes that form amyloid plaques (APP and PS/APP) have significantly reduced T(2) values compared with NTg controls. Thus, T(2) changes in these AD models can precede amyloid deposition or even occur in AD models that do not deposit beta-amyloid (PS mice), but are intensified in the presence of amyloid deposition.

PPARG locus haplotype variation and exacerbations in asthma

The peroxisome proliferator-activated receptor gamma (PPARgamma) regulates inflammation and may play a role in asthma. Using mouthwash-derived DNA and clinical interviews and measurements, we investigated the association of previously characterized single-nucleotide polymorphisms in the PPARG gene (Pro12Ala, C1431T, and C-681G) with asthma exacerbations in patients aged 3-22 years (n=569). The common homozygous haplotype combination of the Pro12 and C1431 alleles was associated with increased risk for asthma exacerbations (ProC, odds ratio (OR) 1.87, 95% confidence interval 1.25-2.79; P=0.002). The ProC genotype was associated with increased school absences (OR 1.82, 95% confidence interval 1.21-2.76; P=0.004) and hospital admissions (OR 2.32, 95% confidence interval 1.18-4.58; P=0.015) over the preceding 6 months. The population-attributable risk of this genotype was 33%. Common genetic variation at the PPARG locus may play an important role in modulating the long-term control of asthma in children and young adults.

Increase in circulating Foxp3+CD4+CD25(high) regulatory T cells in nasopharyngeal carcinoma patients

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated disease with high prevalence in Southern Chinese. Using multiparametric flow cytometry, we identified significant expansions of circulating naïve and memory CD4+CD25(high) T cells in 56 NPC patients compared with healthy age- and sex-matched controls. These were regulatory T cells (Treg), as they overexpressed Foxp3 and GITR, and demonstrated enhanced suppressive activities against autologous CD4+CD25- T-cell proliferation in functional studies on five patients. Abundant intraepithelial infiltrations of Treg with very high levels of Foxp3 expression and absence of CCR7 expression were also detected in five primary tumours. Our current study is the first to demonstrate an expansion of functional Treg in the circulation of NPC patients and the presence of infiltrating Treg in the tumour microenvironment. As Treg may play an important role in suppressing antitumour immunity, our findings provide critical insights for clinical management of NPC.

Stereotactic Radiotherapy for the Treatment of Pituitary Adenomas

PURPOSE

The aim of this study was to retrospectively review local control and morbidity following stereotactic radiotherapy (SRT) for pituitary adenoma.

METHODS

Between 1997 and 2004, 39 patients with pituitary adenomas received SRT. Median age was 56 years (range: 13 to 90 years). Thirty-three patients underwent incomplete transsphenoidal surgery prior to SRT and six had unresectable tumors. The largest tumor dimension varied from 1.7 to 6 cm (median: 3 cm). Tumor volume varied from 1.2 to 56 mL (median 10.5 mL). Thirty-five tumors were < or = 1 mm from the optic chiasm/nerve. Thirty-three tumors were non-functional. SRT was delivered by a dedicated linear accelerator (Novalis, Heimstetten, Germany). Beam collimation was achieved by a fixed circular collimator (five patients) or a micro-multileaf collimator (34 patients). Total dose varied from 4500 to 5040 cGy (median: 4860 cGy) and was prescribed at the 90 % isodose line.

RESULTS

After a median follow-up of 32 months (range: 12 to 94 months), the local control rate was 100 %. Tumor size was stable in 26 patients and decreased in 13 patients. Hormone normalization did not occur following SRT. New endocrine deficiency occurred in six patients. No patient developed cranial nerve injury or second malignancy following treatment.

CONCLUSIONS

SRT achieves a high rate of local control and a low rate of treatment-induced morbidity. SRT is applicable to pituitary adenomas in close proximity to the optic apparatus and tumors in excess of three centimeters in the greatest dimension. Further follow-up is necessary to establish the long-term outcome following SRT for pituitary adenomas.

Effect of atenolol on QTc interval lengthening during hypoglycaemia in type 1 diabetes

AIMS/HYPOTHESIS

Hypoglycaemia is associated with heart rate-corrected QT (QTc) interval lengthening on the ECG; this may be important in the pathogenesis of sudden overnight death in young people with diabetes. Since hypoglycaemic QTc lengthening appears to be mediated through the sympathoadrenal response, we tested the hypothesis that beta1-blockade will prevent these changes in type 1 diabetic patients and so provide a potential therapeutic intervention.

METHODS

We studied eight type 1 diabetic adults without cardiovascular or renal complications. Similar hypoglycaemic clamp studies were performed on two occasions, at least 4 weeks apart, but immediately before one visit subjects received atenolol 100 mg daily for 7 days. Following a 60-min euglycaemic (5 mmol/l) period, blood glucose was lowered over 30 min to 2.5 mmol/l, and held for 60 min. High-resolution ECG was recorded at baseline and at 0, 30 and 60 min during each glycaemic plateau. QT interval was measured using a semiautomated tangent method and QTc was derived from QT using the Fridericia formula.

RESULTS

Mean (SD) baseline QTc was similar at both visits: control 391 (30) ms, post-atenolol 386 (34) ms; (p=0.33). Without atenolol pretreatment, QTc lengthened during hypoglycaemia to a maximum of 448 (34) ms (p<0.001). On atenolol, QTc lengthening was significantly reduced (peak QTc 413 (27) ms; p=0.004 vs control visit).

CONCLUSIONS/INTERPRETATION

Hypoglycaemic QTc lengthening is blunted by atenolol in patients with type 1 diabetes. Selective beta1-blockade may help prevent sudden death, if we can identify those at high risk.

Dual stimulation of Epstein-Barr Virus (EBV)-specific CD4+- and CD8+-T-cell responses by a chimeric antigen construct: potential therapeutic vaccine for EBV-positive nasopharyngeal carcinoma

Virus-associated malignancies are potential targets for immunotherapeutic vaccines aiming to stimulate T-cell responses against viral antigens expressed in tumor cells. Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma, a high-incidence tumor in southern China, expresses a limited set of EBV proteins, including the nuclear antigen EBNA1, an abundant source of HLA class II-restricted CD4(+) T-cell epitopes, and the latent membrane protein LMP2, a source of subdominant CD8(+) T-cell epitopes presented by HLA class I alleles common in the Chinese population. We used appropriately modified gene sequences from a Chinese EBV strain to generate a modified vaccinia virus Ankara recombinant, MVA-EL, expressing the CD4 epitope-rich C-terminal domain of EBNA1 fused to full-length LMP2. The endogenously expressed fusion protein EL is efficiently processed via the HLA class I pathway, and MVA-EL-infected dendritic cells selectively reactivate LMP2-specific CD8(+) memory T-cell responses from immune donors in vitro. Surprisingly, endogenously expressed EL also directly accesses the HLA class II presentation pathway and, unlike endogenously expressed EBNA1 itself, efficiently reactivates CD4(+) memory T-cell responses in vitro. This unscheduled access to the HLA class II pathway is coincident with EL-mediated redirection of the EBNA1 domain from its native nuclear location to dense cytoplasmic patches. Given its immunogenicity to both CD4(+) and CD8(+) T cells, MVA-EL has potential as a therapeutic vaccine in the context of nasopharyngeal carcinoma.

Inhibition of tumour necrosis factor-alpha secretion from rat astrocytes by Sesim-Tang

Substance P (SP) can stimulate secretion of tumour necrosis factor-alpha (TNF-alpha) from astrocytes stimulated with lipopolysaccharide (LPS). In this study, we have examined whether an aqueous extract of Sesim-Tang inhibits the secretion of TNF-alpha from primary cultures of rat astrocytes. Sesim-Tang (10-1000 microg/mL) significantly inhibited the TNF-alpha secretion by astrocytes stimulated with LPS and SP. Interleukin-1 (IL-1) has been shown to elevate TNF-alpha secretion from LPS-stimulated astrocytes while having no effect on astrocytes in the absence of LPS. We therefore examined whether IL-1 mediated inhibition of TNF-alpha secretion from primary astrocytes by Sesim-Tang. Treatment with Sesim-Tang (10-1000 microg/mL) of astrocytes stimulated with both LPS and SP decreased IL-1 secretion significantly. Moreover, the secretion of TNF-alpha by LPS and SP in astrocytes was progressively inhibited with increasing amounts of IL-1 neutralizing antibody. Our results suggest that Sesim-Tang may inhibit TNF-alpha secretion by inhibiting IL-1 secretion and that Sesim-Tang has an antiinflammatory activity in the central nervous system.

Analytical ultracentrifugation studies of translin: analysis of protein-DNA interactions using a single-stranded fluorogenic oligonucleotide

Translin is a recently identified nucleic acid binding protein that appears to be involved in the recognition of conserved sequences found at many chromosomal breakpoints. Previous reports indicate that, based on gel filtration analysis and electron microscopy of protein-DNA complexes, translin forms an octameric structure that binds the DNA. In this study, we further examine the possibility of self-association of translin and its interactions with DNA by analytical ultracentrifugation. Sedimentation velocity analysis of translin indicates that the predominant species sediments with a sedimentation coefficient of 8.5 S and has a frictional ratio, f/f(omicron), of 1.35; these data are consistent with the presence of an octamer with an ellipsoidal configuration; a small amount of a component with significantly higher mass is also present. Equilibrium sedimentation studies of translin at three different protein concentrations also indicate that the predominant species present is an octamer with a minor fraction of aggregated species. Neither monomer nor dimer was detected. Sedimentation equilibrium studies of translin with an FITC-labeled single-stranded oligonucleotide were performed to examine the interaction. A novel analysis method has been developed to analyze protein-nucleic acid interactions based on global fitting of scans of 280 and 490 nm to appropriate mathematical models. Utilizing this method, it was determined that the DNA binding species of translin is an octamer binding a single-stranded oligonucleotide with a DeltaG degrees value of -9.49 +/- 0.12 kcal/mol, corresponding to a dissociation constant, K(d), of 84 +/- 17 nM. On the basis of this evidence and electron microscopy, it is envisioned that translin forms an annular structure of eight subunits, hydrodynamically an oblate ellipsoid, which binds DNA at chromosomal breakpoints.

The role of bacteria in gallstone pathogenesis

Bacteria are often found in high concentrations in brown pigment and less so in cholesterol gallstones. Although it is intriguing to hypothesize that cholesterol stone formation is non-bacterial in nature and principally different from the pathogenesis of "infectious" brown pigment gallstones, it is more likely that significant overlap exists between the two processes. Most gallstones are composite in nature. Using molecular-genetic methods, bacteria can be found in most pure cholesterol gallstones (i.e. those whose structure consists of more than 90% cholesterol). The natural history of the gallstones development is unknown. It is likely that brown pigment stones can evolve in their chemical composition after the termination of the infectious process that initiate their formation, and may further develop into either mixed or nearly pure cholesterol stones. In a similar fashion, cholesterol-poor or black pigment gallstones may act as foreign bodies to enhance the propensity of bacterial colonization in the presence of pre-existing gallstones or cholangitis, thereby activating pathways of bacterial lithogenesis and resulting in the encasement of cholesterol nuclei with pigment shells and/or in the internal remodeling of extant stones. It is often difficult, if not impossible, to ascertain whether bacterial infection of bile arose before stone formation or vice-versa. The development of gallstones (nucleation, assembly of microcalculi, growth, remodeling) includes the interaction of both bacterial and non-bacterial mechanisms, working discontinuously over years and decades and shaping the structural individuality of each stone. At cholecystectomy, the gallstone removed from the patient represents the end product of a long pathologic process. Although our understanding of the exact temporal contribution of bacteria in lithogenesis is incomplete, it is important for the clinician to realize that most gallstones are colonized by a bacterial biofilm, even though the bile may be culture-negative.

The role of bacteria in gallstone pathogenesis

Bacteria are often found in high concentrations in brown pigment and less so in cholesterol gallstones. Although it is intriguing to hypothesize that cholesterol stone formation is non-bacterial in nature and principally different from the pathogenesis of "infectious" brown pigment gallstones, it is more likely that significant overlap exists between the two processes. Most gallstones are composite in nature. Using molecular-genetic methods, bacteria can be found in most pure cholesterol gallstones (i.e. those whose structure consists of more than 90% cholesterol). The natural history of the gallstones development is unknown. It is likely that brown pigment stones can evolve in their chemical composition after the termination of the infectious process that initiate their formation, and may further develop into either mixed or nearly pure cholesterol stones. In a similar fashion, cholesterol-poor or black pigment gallstones may act as foreign bodies to enhance the propensity of bacterial colonization in the presence of pre-existing gallstones or cholangitis, thereby activating pathways of bacterial lithogenesis and resulting in the encasement of cholesterol nuclei with pigment shells and/or in the internal remodeling of extant stones. It is often difficult, if not impossible, to ascertain whether bacterial infection of bile arose before stone formation or vice-versa. The development of gallstones (nucleation, assembly of microcalculi, growth, remodeling) includes the interaction of both bacterial and non-bacterial mechanisms, working discontinuously over years and decades and shaping the structural individuality of each stone. At cholecystectomy, the gallstone removed from the patient represents the end product of a long pathologic process. Although our understanding of the exact temporal contribution of bacteria in lithogenesis is incomplete, it is important for the clinician to realize that most gallstones are colonized by a bacterial biofilm, even though the bile may be culture-negative.

Variations of the prominences of the bony palate and their relationship to complete dentures in Korean skulls

The osteological and morphological variations of the prominences in the bony palate of 160 Korean skulls were studied. The frequency of the occurrence of the posterior palatine crest, located on the posterior border of the greater palatine foramen, was 13.8%. Palatal ridges were observed commonly in the skulls; however, the smooth type, which has no palatal ridges in the palate, was shown in 14.7% of cases, and palatal spines were observed in 33.8%. The prevalence of palatal tubercles was 11.6%, and all were found in the molar region. The palatine torus was found in 18.8% of cases and the most common type was along the median palatine suture from the incisive foramen to the posterior border of the palatine bone (63.3%). No significant differences between sexes or sides were found in the posterior palatine crest, palatal ridges, and palatal tubercle. However, the sex distribution of the palatine torus was significantly different (P < 0.05). These results would be helpful clinically in fabricating maxillary complete dentures for edentulous patients.

Gallstones

Gallstones are estimated to affect over 20 million people in the United States. Recent studies have clarified the role of various dietary components in gallstone disease. Also, insulin resistance has been demonstrated to be a risk factor for gallstones. Other research has focused on the pathophysiology of gallstones and on clarifying the underlying mechanisms of previously noted risk factors for gallstones. New techniques for the noninvasive diagnosis of bile duct stones continue to be developed and tested. These techniques include computed tomography and magnetic resonance cholangiography. The impact and appropriateness of laparoscopic cholecystectomy continue to debated, and studies point to both overuse and underuse of this operation in the management of the disease.

Epstein-Barr virus-specific cytotoxic T lymphocyte responses in the blood and tumor site of Hodgkin's disease patients: implications for a T-cell-based therapy

Approximately 40% of Hodgkin's disease (HD) cases carry EBV in the malignant Hodgkin-Reed Sternberg (H-RS) cells, with expression of viral latent membrane proteins (LMPs) 1 and 2. These viral proteins are targets for CTLs in healthy EBV carriers, and their expression in EBV-associated HD raises the possibility of targeting them for a CTL-based immunotherapy. Here we characterize the CTL response to EBV latent antigens in both the blood and tumor-infiltrating lymphocytes of HD patients using two approaches: (a) in vitro reactivation of CTLs by stimulation with the autologous EBV-transformed lymphoblastoid cell line; and (b) an enzyme-linked immunospot assay to quantify frequencies of CTLs specific for known LMP1/2 epitopes. We detected EBV-specific CTLs in blood and biopsy samples from both EBV-negative and EBV-positive HD patients. However, as in healthy EBV carriers, LMP-specific CTL precursors occurred only at low frequency in the blood of HD patients, and with the exception of one EBV-negative HD case, were undetectable in the tumor. These data give rise to two considerations: (a) they may explain why EBV-positive tumor cells persist in the presence of an existing EBV-specific immune response; and (b) they provide a rationale for selectively boosting/eliciting LMP-specific CTL responses as a therapy for EBV-positive HD.

Cyclophilin a binds to peroxiredoxins and activates its peroxidase activity

Six distinct peroxiredoxin (Prx) proteins (Prx I-VI) from distinct genes have been identified in mammalian tissues. Prxs are members of a group of peroxidases that have conserved reactive cysteine residue(s) in the active site(s). An immediate physiological electron donor for the peroxidase catalysis for five Prx proteins (Prx I-V) has been identified as thioredoxin (Trx), but that for Prx VI (1-Cys Prx) is still unclear. To identify an immediate electron donor and a binding protein for Prx VI, we performed a Prx VI protein overlay assay. A 20-kDa binding protein was identified by the Prx VI protein overlay assay with flow-through fractions from a High-Q column with rat lung crude extracts. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and MS-Fit, we identified the 20-kDa Prx VI-binding protein as a cyclophilin A (CyP-A). The binding of recombinant human CyP-A (hCyP-A) to Prx VI was confirmed by using the hCyP-A protein overlay assay and Western immunoblot analysis with hCyP-A-specific antibodies. hCyP-A enhanced the antioxidant activity of Prx VI, as well as the other known mammalian Prx isotypes. hCyP-A supported antioxidant activity of Prx II and Prx VI both against thiol (dithiothreitol)-containing metal-catalyzed oxidation (MCO) systems and ascorbate-containing MCO systems. Prx II was reduced by hCyP-A without help from any other reductant, and the reduction was cyclosporin A-independent. These results strongly suggest that CyP-A not only binds to Prx proteins but also supports its peroxidase activity as an immediate electron donor. In addition, Cys(115) and Cys(161) of hCyP-A were found to be involved in the activation and the reduction of Prx.

The effect of total sleep deprivation on cognitive functions in normal adult male subjects

This study was conducted to evaluate the effect of acute sleep deprivation on cognitive functions. A total of 18 healthy right handed males were deprived of sleep for 24 hours. Luria-Nebraska Neuropsychological Battery and calculation & digit-span subtest of K-WAIS were administered before and after sleep deprivation in order to examine the changes of cognitive functions. There were no differences in freedom from distractibility, tacile function, visual function, reading, writing, arithmetic and intellectual process function. However, the cognitive functions such as motor, rhythm, receptive & expressive speech, memory and complex verbal arithmetic function were decreased after sleep deprivation. All of these functions are known to be related to the right anterior hemisphere. For localization scales, the scores of right frontal and right temporal dysfunction scale were increased after sleep deprivation. These results indicate that sleep deprivation has a negative effect on cognitive functions, especially those associated with right anterior hemisphere or subcortical areas.

Identification of oxysterols in human bile and pigment gallstones

BACKGROUND AND AIMS

Although cholesterol is the most abundant sterol in animal tissues, oxidized products of cholesterol (oxysterols) also occur in mammalian organs and blood and are cytotoxic, atherogenic, and carcinogenic. However, the presence of oxysterols in bile or gallstones has never been reported.

METHODS

Fresh human bile and gallstones were collected. Sterol content and structure were analyzed using gas chromatography/mass spectrometry (GC/MS). Bacterial DNA was extracted from human gallstones.

RESULTS

GC/MS identified cholesta-4,6-diene-3-one and cholest-4-ene-3-one, with several as yet unidentified oxysterols in bile and stone samples. Several plant and fungal sterols were also present in gallstones. When 102 human gallstones were analyzed for oxysterols, they were markedly higher (as percent of total sterols) in pigment gallstones, where bacterial DNA is most abundant.

CONCLUSIONS

These observations suggest biliary oxysterols are associated with the presence of bacteria and may play a role in the pathogenesis of gallstones and biliary tract cancers.

In vivo measurements of brain glucose transport using the reversible Michaelis-Menten model and simultaneous measurements of cerebral blood flow changes during hypoglycemia

Glucose is the major substrate that sustains normal brain function. When the brain glucose concentration approaches zero, glucose transport across the blood-brain barrier becomes rate limiting for metabolism during, for example, increased metabolic activity and hypoglycemia. Steady-state brain glucose concentrations in alpha-chloralose anesthetized rats were measured noninvasively as a function of plasma glucose. The relation between brain and plasma glucose was linear at 4.5 to 30 mmol/L plasma glucose, which is consistent with the reversible Michaelis-Menten model. When the model was fitted to the brain glucose measurements, the apparent Michaelis-Menten constant, Kt, was 3.3 +/- 1.0 mmol/L, and the ratio of the maximal transport rate relative to CMRglc, Tmax/CMRglc, was 2.7 +/- 0.1. This Kt is comparable to the authors' previous human data, suggesting that glucose transport kinetics in humans and rats are similar. Cerebral blood flow (CBF) was simultaneously assessed and constant above 2 mmol/L plasma glucose at 73 +/- 6 mL 100 g(-1) min(-1). Extrapolation of the reversible Michaelis-Menten model to hypoglycemia correctly predicted the plasma glucose concentration (2.1 +/- 0.6 mmol/L) at which brain glucose concentrations approached zero. At this point, CBF increased sharply by 57% +/- 22%, suggesting that brain glucose concentration is the signal that triggers defense mechanisms aimed at improving glucose delivery to the brain during hypoglycemia.

Characterization of model bile using fluorescence energy transfer from dehydroergosterol to dansylated lecithin

Fluorescence energy transfer from dehydroergosterol (DHE) to dansylated lecithin (DL) was used to characterize lecithin-cholesterol vesicles in the presence of the bile salt, sodium taurocholate. At lipid concentrations approximating physiological levels, exposure of fluorescently labeled vesicles to the bile salt led to a dose-dependent increase in the DHE-to-DL fluorescence ratio during the first 24 h after mixing. The initial changes in the fluorescence ratio correlated well with conventional turbidity measurements that quantify partial micellization of vesicles as a function of bile salt loading. In addition, fluorescence energy transfer from DHE to DL revealed cholesterol enrichment of vesicles and re-vesiculation of micelles at bile salt loadings for which vesicles and micelles coexisted. Samples containing the cholesterol-enriched vesicle fraction exhibited further increases in the DHE-to-DL fluorescence ratio during a 4-week observation period but only after a significant lag period of several days. The lag period decreased with cholesterol loading, and the increase in the fluorescence ratio always preceded the appearance of microscopic, birefringent, either needlelike or platelike, cholesterol crystals, in samples that were initially supersaturated with cholesterol. Cholesterol crystals were not observed, and the fluorescence ratio did not increase, for any sample that was undersaturated with cholesterol.Taken together, these results suggest that the latter changes in fluorescence are the result of cholesterol nucleation. Fluorescence energy transfer from DHE to DL is therefore a promising technique for the characterization of model bile and, possibly, provides a direct measurement of cholesterol nucleation.

Hepatic toxicity and recovery of Fischer 344 rats following exposure to 2-aminoanthracene by intraperitoneal injection

Humans may be exposed to 2-aminoanthracene (2-AA), a substituted polycyclic aromatic hydrocarbon, and a recognized mutagen and carcinogen, through oral and respiratory routes from contact with a variety of environmental sources. For the present study, we sought to evaluate hepatic damage and recovery in Fischer 344 rats following multiple i.p. injections of 5 mg of 2-AA. Rats were injected weekly for up to 5 weeks. Subgroups were then allowed to recover for 1, 5, or 9 weeks, and biochemical and pathologic changes were evaluated. We observed that weight gains were reduced relative to controls for all groups receiving > or = 2 injections. Serum enzyme levels indicative of liver damage were evident and included alterations in serum aspartate aminotransferase, alkaline phosphatase, total protein, albumin, and globulin. These alterations usually returned to normal by 5 weeks following cessation of 2-AA administration. In contrast, histologic liver changes, including hepatocyte hypertrophy, biliary hyperplasia with oval cell proliferation, altered foci, nodular hyperplasia, and one hepatocellular adenoma became more severe with time. This experiment demonstrates patterns of hepatic damage and recovery in rats exposed to 2-AA.

Relative changes of cerebral arterial and venous blood volumes during increased cerebral blood flow: implications for BOLD fMRI

Measurement of cerebral arterial and venous blood volumes during increased cerebral blood flow can provide important information regarding hemodynamic regulation under normal, pathological, and neuronally active conditions. In particular, the change in venous blood volume induced by neural activity is one critical component of the blood oxygenation level-dependent (BOLD) signal because BOLD contrast is dependent only on venous blood, not arterial blood. Thus, relative venous and arterial blood volume (rCBV) and cerebral blood flow (rCBF) in alpha-chlorolase-anesthetized rats under hypercapnia were measured by novel diffusion-weighted (19)F NMR following an i.v. administration of intravascular tracer, perfluorocarbons, and continuous arterial spin labeling methods, respectively. The relationship between rCBF and total rCBV during hypercapnia was rCBV(total) = rCBF(0.40), which is consistent with previous PET measurement in monkeys. This relationship can be linearized in a CBF range of 50-130 ml/100 g/min as DeltarCBV(total)/ DeltarCBF = 0.31 where DeltarCBV and DeltarCBF represent rCBV and rCBF changes. The average arterial volume fraction was 0.25 at a basal condition with CBF of approximately 60 ml/100 g/min and increased up to 0.4 during hypercapnia. The change in venous rCBV was 2-fold smaller than that of total rCBV (DeltarCBV(vein)/DeltarCBF = 0.15), while the arterial rCBV change was 2.5 times larger than that of total rCBV (DeltarCBV(artery)/DeltarCBF = 0.79). These NMR results were confirmed by vessel diameter measurements with in vivo videomicroscopy. The absolute venous blood volume change contributes up to 36% of the total blood volume change during hypercapnia. Our findings provide a quantitative physiological model of BOLD contrast.

Targeting antigen in mature dendritic cells for simultaneous stimulation of CD4+ and CD8+ T cells

Due to their potent immunostimulatory capacity, dendritic cells (DC) have become the centerpiece of many vaccine regimens. Immature DC (DCimm) capture, process, and present Ags to CD4(+) lymphocytes, which reciprocally activate DCimm through CD40, and the resulting mature DC (DCmat) loose phagocytic capacity, but acquire the ability to efficiently stimulate CD8(+) lymphocytes. Recombinant vaccinia viruses (rVV) provide a rapid, easy, and efficient method to introduce Ags into DC, but we observed that rVV infection of DCimm results in blockade of DC maturation in response to all activation signals, including CD40L, monocyte-conditioned medium, LPS, TNF-alpha, and poly(I:C), and failure to induce a CD8(+) response. By contrast, DCmat can be infected with rVV and induce a CD8(+) response, but, having lost phagocytic activity, fail to process the Ag via the exogenous class II pathway. To overcome these limitations, we used the CMV protein pp65 as a model Ag and designed a gene containing the lysosomal-associated membrane protein 1 targeting sequence (Sig-pp65-LAMP1) to target pp65 to the class II compartment. DCmat infected with rVV-Sig-pp65-LAMP1 induced proliferation of pp65-specific CD4(+) clones and efficiently induced a pp65-specific CD4(+) response, suggesting that after DC maturation the intracellular processing machinery for class II remains intact for at least 16 h. Moreover, infection of DCmat with rVV-Sig-pp65-LAMP1 resulted in at least equivalent presentation to CD8(+) cells as infection with rVV-pp65. These results demonstrate that despite rVV interference with DCimm maturation, a single targeting vector can deliver Ags to DCmat for the effective simultaneous stimulation of both CD4(+) and CD8(+) cells.

Alterations of the p53 and pRB pathways in human astrocytoma

Human astrocytomas are characterized by a number of molecular changes affecting two critical tumor suppressor pathways: the pRB and the p53 pathways. Genetic alterations functionally eliminate pRB and p53 themselves or upstream and/or downstream molecules such as products of the Ink4a/ARF locus, p16Ink4a and p14ARF. As a result, malignant cells are defective in critical cell cycle and apoptosis regulatory elements contributing to unrelenting tumour growth and invasion. Current research aims to discover effective means of reconstituting p53 and pRB pathway components in an effort to attenuate the aggressive phenotype of astrocytoma.

Discovery of a novel member of the histamine receptor family

We report the discovery, tissue distribution and pharmacological characterization of a novel receptor, which we have named H4. Like the three histamine receptors reported previously (H1, H2, and H3), the H4 receptor is a G protein-coupled receptor and is most closely related to the H3 receptor, sharing 58% identity in the transmembrane regions. The gene encoding the H4 receptor was discovered initially in a search of the GenBank databases as sequence fragments retrieved in a partially sequenced human genomic contig mapped to chromosome 18. These sequences were used to retrieve a partial cDNA clone and, in combination with genomic fragments, were used to determine the full-length open reading frame of 390 amino acids. Northern analysis revealed a 3.0-kb transcript in rat testis and intestine. Radioligand binding studies indicated that the H4 receptor has a unique pharmacology and binds [(3)H]histamine (K(d) = 44 nM) and [(3)H]pyrilamine (K(d) = 32 nM) and several psychoactive compounds (amitriptyline, chlorpromazine, cyproheptadine, mianserin) with moderate affinity (K(i) range of 33-750 nM). Additionally, histamine induced a rapid internalization of HA-tagged H4 receptors in transfected human embryonic kidney 293 cells.

Effects of bile salts on cholestan-3beta,5alpha,6beta-triol-induced apoptosis in dog gallbladder epithelial cells

Oxysterols are cytotoxic agents. The gallbladder epithelium is exposed to high concentrations of oxysterols, and so elucidating the mechanisms of cytotoxicity in this organ may enhance our understanding of the pathogenesis of biliary tract disorders. We investigated the cytotoxic effects of the oxysterol cholestan-3beta,5alpha,6beta-triol (TriolC) on dog gallbladder epithelial cells. Apoptosis was the major form of cytotoxicity, as determined by analysis of nuclear morphologic changes and by multiparameter flow cytometry. Hydrophobic bile salts are known to have cytotoxic effects, whereas hydrophilic bile salts have cytoprotective effects. We therefore examined whether the hydrophobic bile acid taurodeoxycholic acid (TDC) and the hydrophilic bile acid tauroursodeoxycholic acid (TUDC) had modifying effects on oxysterol-induced cytotoxicity. TriolC caused an increase in the number of apoptotic cells from 14+/-11% (control) to 48+/-12% of total cells (P<0.01). After combining TriolC with TDC, cell apoptosis increased to 63+/-16% (P<0.05), whereas after addition of TUDC, the number of apoptotic cells decreased to 31+/-12% (P<0.05) of total cells. In summary, oxysterols such as TriolC induce apoptosis. Hydrophobic bile salts enhance TriolC-induced apoptosis, whereas hydrophilic bile salts diminish TriolC-induced apoptosis. These results suggest that interactions between oxysterols and bile salts play a role in the pathophysiology of biliary tract disorders.

Anatomical study of the pyramidal process of the palatine bone in relation to implant placement in the posterior maxilla

The placement of dental implants in the molar region of the maxilla is often difficult because of insufficient bone volume and the inferior bone quality. In order to avoid these limitations, the pillar of bone, which is composed of the maxillary tuberosity, the pyramidal process of the palatine bone and the pterygoid process of the sphenoid bone, was introduced for implant placement. In fact, the pyramidal process is the posterior structure where implants are placed but until now, there is no available data of the size or shape of the pyramidal process. Therefore, we measured the height, anteroposterior distance and mediolateral distance of the pyramidal process and observed the shape of lateral and posterior surfaces of the pyramidal process of 54 Korean edentulous dry skulls in this study. The height was 13.1 mm (male: 13.6 mm, female: 12.4 mm). The anteroposterior distance was 6.5 mm (male: 6.7 mm, female: 6.1 mm). The mediolateral distance was 9.5 mm (male: 9.9 mm, female: 9.0 mm). The most common type was the right-angled triangle in the lateral surface (44.4%) and in the posterior surface (66.7%). There was no statistical significance between the male and the female in all items (P > 0.05). These results provide anatomical features in relation to placement of dental implants in the molar region of the maxilla and would be useful in treatment planning of partially or completely edentulous patients.

Dermatofibrosarcoma protuberans: treatment results of 35 cases

BACKGROUND AND PURPOSE

This study evaluates the treatment results of patients with dermatofibrosarcoma protuberans.

PATIENTS AND METHODS

Between August 1987 and July 1998, 35 consecutive patients with pathologically proved dermatofibrosarcoma protuberans received surgery with or without radiation therapy. Their treatment results were analyzed retrospectively.

RESULTS

The patient ages ranged from 5 to 67 years (median 37 years). There were 24 males and 11 females. The anatomic sites of tumor were: trunk in 21, extremity in eight, and head and neck region in six. The maximal dimension of tumor ranged from 1.5 to 25 cm. Surgery techniques included local excision and wide excision with or without graft or flap. Adjuvant radiation therapy was given to 11 patients, with a dose ranging from 46 to 68 Gy (one pre-operative, ten post-operative). At a median follow-up of 50 months (range 11-131 months), there were 11 patients (nine patients without radiation therapy) who developed local failure. Salvage therapy (excision with or without radiation therapy) was given to all of them, and ten achieved disease control. Some patients had treatment-related moderate cosmetic or functional problems.

CONCLUSIONS

Dermatofibrosarcoma protuberans is a malignancy of a high cure rate, and adjuvant radiation therapy can reliably decrease the local recurrence rate and prevent mutilation and functional deficit caused by repeated surgery.

Oligomerization of dopamine and serotonin receptors

Until recently, it has largely been assumed that G protein-coupled receptors (GPCRs) function as monomeric entities. However, over the past few years, we and others have documented that GPCRs can form dimers and oligomers, leading to a re-evaluation of the mechanisms thought to mediate GPCR function. Despite the growing number of investigations into dimerization, little is known about the structural basis of receptor-receptor interactions and the functional consequences of dimer formation. Here, we present a brief review of some insights we have gained into the dimerization of dopamine and serotonin receptors. We have demonstrated that agonist-regulated trafficking is identical for receptor monomers and dimers, however, agonist treatment appears to stabilise the receptor oligomers. An investigation of the structural assembly between receptors involved in dimerization showed that there are several sites of interaction including hydrophobic transmembrane domain interactions and intermolecular disulphide bonds. We have also examined receptor hetero-oligomerization and demonstrated the potential for novel functions as a result of these associations. Finally, as a result of these observations, we have been able to present evidence that GPCRs function as oligomers in the cell.

Anaerobic bacteria and intrahepatic stones: detections of Clostridium sp. and Bacteroides fragilis

OBJECTIVE

To detect anaerobic bacteria Clostridium sp. and Bacteroides fragilis in intrahepatic stones by molecular genetic method.

METHODS

DNA was extracted from 59 stone samples and subjected to polymerase chain reaction (PCR) amplification targeting the 16S rRNA gene of Clostridium sp. and the glutamine synthetase gene of Bacteroides fragilis. Single-strand conformational polymorphism (SSCP) analysis was performed to identify the Clostridium sp.

RESULTS

16S rRNA gene sequences for Clostridium sp. were identified in 49 stones (83%, 49/59). The two most common groups were detected in 19 (41%) and 17 (37%) of the 46 samples using SSPC analysis, and 25/59 (42%) stones were tested positive for Bacteroides fragilis.

CONCLUSIONS

Anaerobes such as Clostridium sp. and Bacteroides fragilis present in intrahepatic stones and may play a role in stone formation. PCR is a useful technique to detect fastidious pathogens, which are difficult to culture. SSCP of PCR products is a rapid method in differentiating bacterial species.

Apical gene transfer into quiescent human and canine polarized intestinal epithelial cells by lentivirus vectors

Intestinal epithelial cells secrete a protective luminal mucus barrier inhibiting viral gene transfer. Quiescent, polarized monolayers of primary epithelial cells from dog gallbladder and human colon are efficiently transduced through the apical mucus side by lentivirus vectors, suggesting their application to intestinal gene therapy.

Cholestan-3beta,5alpha,6beta-triol, but not 7-ketocholesterol, suppresses taurocholate-induced mucin secretion by cultured dog gallbladder epithelial cells

In order to investigate oxysterol-mediated effects on the biliary system, we studied the effects of cholestan-3beta,5alpha,6beta-triol (TriolC) and 7-ketocholesterol (7KC) on gallbladder epithelial cells. We compared their cell proliferation effects in cultured dog gallbladder epithelial cells (DGBE) to their effects in cultured human pulmonary artery endothelial cells (HPAE). Oxysterols inhibited cell proliferation in a dose-dependent fashion. Oxysterols inhibited cell growth to 50% of control at a higher dose for DGBE cells than for HPAE cells. TriolC was more cytotoxic than 7KC. We also investigated the effect of oxysterols on bile salt-induced mucin secretion by DGBE cells. TriolC suppressed mucin secretion by DGBE cells, whereas 7KC did not. These findings support the hypothesis that biliary oxysterols affect gallbladder mucosal function.

Second malignant tumors in patients with nasopharyngeal carcinoma and their association with Epstein-Barr virus

Since previous published studies about second malignant tumors (SMTs) in nasopharyngeal carcinoma (NPC) patients usually included a limited sample size and did not attain consistent results, we conducted a large retrospective study in a cohort of 1,549 patients to assess the risk of SMT in NPC patients following radiotherapy (RT) in Taiwan. The follow-up period ranged from 2 to 16 years, with a median of 7 years. Thirty-nine patients developed SMTs during the 7,145 person-year follow-up [standardized incidence ratio (SIR): 2. 8; 95% confidence interval (CI): 2.0 to 3.9]. Increased risks of developing SMTs were observed for head and neck (H/N) cancer (SIR: 16.5; 95% CI: 10.0 to 26.8), gastric cancer (SIR: 5.5; 95% CI: 2.2 to 11.4) and leukemia (SIR: 9; 95% CI: 1.9 to 26.3). Paraffin-embedded specimens of secondary H/N cancer (11), secondary gastric cancer (6) and their corresponding NPC specimens were examined by EBER in situ hybridization to assess the association between Epstein-Barr virus (EBV) and these SMTs. Twenty-six primary H/N and 5 gastric cancer specimens were chosen as the control groups. In H/N cancer, EBV was detected in 3.8% of the primary cancers and 9.1% of the secondary cancers. All the positive specimens resulted from hypopharyngeal cancer. Of the secondary gastric cancers, only 1 case (16.6%) was associated with EBV. None of the primary gastric cancers was associated with EBV. Our results indicate an increased risk of developing SMTs, with a preference for head and neck cancer, gastric cancer and leukemia, in NPC patients after RT in Taiwan. Only a small proportion of the secondary H/N and gastric cancers was associated with EBV.

Comparison of clinical behaviors and responses to radiation between squamous cell carcinomas and adenocarcinomas/adenosquamous carcinomas of the cervix

BACKGROUND

Adenocarcinomas/adenosquamous carcinomas (AC/ASC) are relatively uncommon histological subtypes in cervical cancer. In this study, we retrospectively compared the clinical behaviors and responses to radiation of squamous cell carcinomas (SCC) and AC/ASC in patients with stage I-IVA cervical cancer primarily treated by radiotherapy (RT).

METHODS

Nine hundred twenty-eight patients with cervical cancer primarily treated with RT were included in this study. Ninety-four percent of the patients had SCC and 6% had AC/ASC. The association of histological subtype to various clinical parameters was assessed. Tumor response and failure patterns were analyzed, and the prognostic significance of histological subtype and other clinical parameters were evaluated by univariate and multivariate analyses.

RESULTS

(1) Patients with AC/ASC had a significantly higher percentage of bulky I-IIA disease, a younger age (< 45 years), and an elevated carcinoembryonic antigen (CEA) level, but a lower percentage of elevated squamous cell carcinoma antigen (SCC-Ag) level, than patients with SCC. Hemoglobin (Hb) levels and lymph node status were not significantly different between SCC and AC/ASC patients. (2) A higher percentage of AS/ASC patients had residual induration 2 to 3 months after RT than those with SCC (40% vs. 21.6%, p = 0.008). Higher local failure rates were found for AC/ASC patients compared to SCC patients (38% vs. 15%, p = 0.001). (3) The 5-year disease-specific survival rate was 66% and 50% for SCC and AC/ASC patients, respectively (p = 0.016). Advanced stages, Hb levels lower than 10 g/dl, positive lymph nodes, AC/ASC histological subtype, and SCC-Ag levels higher than 10 ng/ml were independent prognostic factors for worse survival for all patients. For patients with AC/ASC in particular, only stage and positive lymph nodes were significant prognostic factors.

CONCLUSION

Cervical cancer patients with AC/ASC are relatively younger and have a higher incidence of elevated CEA and a lower incidence of elevated SCC-Ag levels than those with SCC. For AC/ASC patients, the tumor responses to RT were relatively slow and poor. This group of patients had a worse survival rate than patients with SCC, mainly because of the higher incidence of uncontrolled local disease for AC/ASC patients.

Elective neck irradiation for nasopharyngeal carcinoma

BACKGROUND

This study was conducted to evaluate the effectiveness of elective neck irradiation (ENI) for nasopharyngeal carcinoma (NPC), and to analyze factors associated with ENI failure.

METHODS

A radiation port covering the side of a neck without gross nodal metastasis was qualified for evaluation of the effectiveness of ENI. From 1988 through 1992, a total of 261 patients with N0 (130 cases), N1 (91 cases), and N3 (40 cases) NPCs were studied. All patients were irradiated with 60Co teletherapy or 10 MV x-ray to a total dose of 46.8 Gy/26 fractions, followed by a boost treatment to the primary site to a total dose of 64.8 to 75.6 Gy/36-42 fractions. All ENI ports received irradiation to a dose of 46.8 to 60.8 Gy. The duration of follow-up was 6 to 10 years, with a median of 8.1 years. Factors associated with to the risk of ENI failure were analyzed.

RESULTS

(1) The overall 5-year actuarial local control rate and actuarial survival rate were 74% and 63%, respectively. (2) Among the 261 cases in which ENI treatment was used, the treatment failed in 12 cases, accounting for a crude ENI failure rate of 5%. The overall 5- and 10-year cumulative risk of ENI failure was 5% and 7%, respectively. (3) Time from the start of treatment to ENI failure ranged from 9 to 66 months, with a median of 17 months. (4) Of the 12 patients for whom EMI failed, 11 (92%) had recurrence in the upper neck, and one in the lower neck. (5) Existence of prior failure at the primary site was the only factor significantly correlated with the risk of ENI failure (p < 0.001). The 5-year cumulative risk of ENI failure for patients with local failure vs. those without was 16% vs. 1% (p < 0.0001).

CONCLUSION

Moderate-dose ENI was highly effective in the control of subclinical disease in the neck for NPC. ENI failure was closely associated with prior failure at the primary site, implying that local primary tumor failure may lead to an increased potential for metastasis to the neck.

CTL control of EBV in nasopharyngeal carcinoma (NPC): EBV-specific CTL responses in the blood and tumors of NPC patients and the antigen-processing function of the tumor cells

Undifferentiated nasopharyngeal carcinoma (NPC) is latently infected with EBV and expresses a restricted number of viral proteins. Studies in healthy virus carriers have demonstrated that at least some of these proteins can act as targets for HLA class I-restricted CTLs. Therefore we have explored the possibility of a CTL-based therapy for NPC by characterizing EBV-specific CTL responses in 10 newly diagnosed NPC cases and 21 healthy virus carriers from Southeast Asia. Using the autologous EBV-transformed lymphoblastoid cell line, virus-specific CTL were reactivated in vitro from PBMC, cloned, and screened for cytotoxicity against target cells expressing individual EBV proteins from recombinant vaccinia vectors. EBV-specific CTLs were identified in 6 of 10 patients and 14 of 21 controls and mainly targeted the EBV nuclear Ag 3 (EBNA3) family of viral latent proteins. However, in 3 of 10 patients and 11 of 21 controls, CTLs specific for the NPC-associated protein LMP2 were also detected, albeit at low frequency. EBV-specific CTLs were detected in tumor biopsy material obtained from 3 of 6 of the patients, indicating that functional CTL are present at the tumor site, but none was specific for tumor-associated viral proteins. To assess the Ag-presenting function in NPC we studied two NPC-derived cell lines (C15 and c666.1) and demonstrated that both were capable of processing and presenting endogenously synthesized protein to HLA class I-restricted CTL clones. Overall, our data provide a sound theoretical basis for therapeutic strategies that aim to boost or elicit LMP2-specific CTL responses in NPC patients.