Opportunistic screening with multiphase contrast-enhanced dual-layer spectral CT for osteoblastic lesions in prostate cancer compared with bone scintigraphy

Our study aimed to compare bone scintigraphy and dual-layer detector spectral CT (DLCT) with multiphase contrast enhancement for the diagnosis of osteoblastic bone lesions in patients with prostate cancer. The patients with prostate cancer and osteoblastic bone lesions detected on DLCT were divided into positive bone scintigraphy group (pBS) and negative bone scintigraphy group (nBS) based on bone scintigraphy. A total of 106 patients (57 nBS and 49 pBS) was included. The parameters of each lesion were measured from DLCT including Hounsfield unit (HU), 40-140 keV monochromatic HU, effective nuclear numbers (Zeff), and Iodine no water (InW) value in non-contrast phase (N), the arterial phase (A), and venous phase (V). The slope of the spectral curve at 40 and 100 keV, the different values of the parameters between A and N phase (A-N), V and N phase (V-N), and hybrid prediction model with multiparameters were used to differentiate pBS from nBS. Receiver operating characteristic analysis was performed to compare the area under the curve (AUC) for differentiating the pBS group from the nBS group. The value of conventional HU values, slope, and InW in A-N and V-N, and hybrid model were significantly higher in the pBS group than in the nBS group. The hybrid model of all significant parameters had the highest AUC of 0.988, with 95.5% sensitivity and 94.6% specificity. DLCT with arterial contrast enhancement phase has the potential to serve as an opportunistic screening tool for detecting positive osteoblastic bone lesions, corresponding to those identified in bone scintigraphy.

Air pollution associate with advanced hepatic fibrosis among patients with chronic liver disease

We aimed to investigate the association between air pollution and advanced fibrosis among patients with metabolic associated fatty liver disease (MAFLD) and chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. A total of 1376 participants who were seropositive for HBV surface antigen (HBsAg) or antibodies to HCV (anti-HCV) or had abnormal liver function in a community screening program from 2019 to 2021 were enrolled for the assessment of liver fibrosis using transient elastography. Daily estimates of air pollutants (particulate matter ≤2.5 μm in diameter [PM2.5 ], nitrogen dioxide [NO2 ], ozone [O3 ] and benzene) were aggregated into mean estimates for the previous year based on the date of enrolment. Of the 1376 participants, 767 (52.8%) and 187 (13.6) had MAFLD and advanced fibrosis, respectively. A logistic regression analysis revealed that the factors associated with advanced liver fibrosis were HCV viremia (odds ratio [OR], 3.13; 95% confidence interval [CI], 2.05-4.77; p < 0.001), smoking (OR, 1.79; 95% CI, 1.16-2.74; p = 0.01), age (OR, 1.04; 95% CI, 1.02-1.05; p < 0.001) and PM2.5 (OR, 1.10; 95% CI, 1.05-1.16; p < 0.001). Linear regression analysis revealed that LSM was independently correlated with PM2.5 (β: 0.134; 95% CI: 0.025, 0.243; p = 0.02). There was a dose-dependent relationship between different fibrotic stages and the PM2.5 level (the PM2.5 level in patients with fibrotic stages 0, 1-2 and 3-4: 27.9, 28.4, and 29.3 μg/m3 , respectively; trend p < 0.001). Exposure to PM2.5 , as well as HBV and HCV infections, is associated with advanced liver fibrosis in patients with MAFLD. There was a dose-dependent correlation between PM2.5 levels and the severity of hepatic fibrosis.

Air pollution as a potential risk factor for hepatocellular carcinoma in Taiwanese patients after adjusting for chronic viral hepatitis

BACKGROUND

Air pollution is a risk factor for hepatocellular carcinoma (HCC). However, the effect of air pollution on HCC risk in patients with hepatitis remains unclear.

METHODS

This cross-sectional study recruited 348 patients with chronic hepatitis who were tested for serum hepatitis B surface antigen (HBsAg) and for antibodies against hepatitis B core antigen (HBcIgG) and hepatitis C virus (anti-HCV) in 2022. The diagnosis of HCC was based on the International Classification of Diseases, 10th revision (ICD-10). Daily estimates of air pollutants were aggregated into mean estimates for the previous year based on the date of recruitment or HCC diagnosis.

RESULTS

Out of 348 patients, 12 had HCC (3.4%). Patients with HCC were older (71.7 vs 50.9 years; p = 0.004), had higher proportion of HBsAg seropositivity (41.7% vs 5.1%; p < 0.001), and substantially higher levels of particulate matter 2.5 (PM 2.5 ) (21.5 vs 18.2 μg/m 3 ; p = 0.05). Logistic regression analysis revealed that the factors associated with HCC were age (odds ratio [OR]: 1.10; CI, 1.03-1.17; p = 0.01), PM 2.5 level (OR: 1.51; CI, 1.02-2.23; p = 0.04), and HBsAg seropositivity (OR: 6.60; CI, 1.51-28.85; p = 0.01) ( Table 3 ). There was a combined effect of PM 2.5 and HBsAg seropositivity on the risk of HCC development (OR: 22.17; CI, 3.33-147.45; p = 0.001).

CONCLUSION

In this study, we demonstrated that PM 2.5 and HBsAg seropositivity were associated with HCC occurrence and had synergistic effects after adjusting for confounding factors.

Quantifying the potential effects of air pollution reduction on population health and health expenditure in Taiwan

Air pollution, particularly ambient fine particulate matter (PM2.5) pollution, poses a significant risk to public health, underscoring the importance of comprehending the long-term impact on health burden and expenditure at national and subnational levels. Therefore, this study aims to quantify the disease burden and healthcare expenditure associated with PM2.5 exposure in Taiwan and assess the potential benefits of reducing pollution levels. Using a comparative risk assessment framework that integrates an auto-aggressive integrated moving average model, we evaluated the avoidable burden of cardiopulmonary diseases (including ischemic heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and diabetes mellitus) and related healthcare expenditure under different air quality target scenarios, including status quo and target scenarios of 15, 10, and 5 μg/m3 reduction in PM2.5 concentration. Our findings indicate that reducing PM2.5 exposure has the potential to significantly alleviate the burden of multiple diseases. Comparing the estimated attributable disease burden and healthcare expenditure between reference and target scenarios from 2022 to 2050, the avoidable disability-adjusted life years were 0.61, 1.83, and 3.19 million for the 15, 10, and 5 μg/m3 target scenarios, respectively. Correspondingly, avoidable healthcare expenditure ranged from US$ 0.63 to 3.67 billion. We also highlighted the unequal allocation of resources and the need for policy interventions to address health disparities due to air pollution. Notably, in the 5 μg/m3 target scenario, Kaohsiung City stands to benefit the most, with 527,368 disability-adjusted life years avoided and US$ 0.53 billion saved from 2022 to 2050. Our findings suggest that adopting stricter emission targets can effectively reduce the health burden and associated healthcare expenditure in Taiwan. Overall, this study provides policymakers in Taiwan with valuable insights for mitigating the negative effects of air pollution by establishing a comprehensive framework for evaluating the co-benefits of air pollution reduction on healthcare expenditure and disease burden.

Air pollution impede ALT normalization in chronic hepatitis B patients treated with nucleotide/nucleoside analogues

Biochemical response is an important prognostic indicator in chronic hepatitis B (CHB) patients receiving nucleotide/nucleoside analogues (NAs). However, the effects of air pollution in alanine aminotransferase (ALT) normalization remain elusive. This longitudinal study recruited 80 hepatitis B e antigen-negative CHB patients who received NAs. ALT levels were measured during the first year of anti-hepatitis B virus therapy. Normal ALT levels were defined as <19 U/L for females and <30 U/L for males, and the risk factors associated with ALT abnormalities were analyzed. The daily estimations of air pollutants (particulate matter ≤2.5 µm in diameter (PM2.5), nitrogen dioxide, ozone (O3), and benzene) were aggregated into the mean estimation for the previous month based on the date of recruitment (baseline) and 1 year later. Sixteen patients (20.0%) had a baseline ALT > 40 U/L; overall, 41 (51.6%) had an abnormal ALT (≥19 U/L for females and ≥ 30 U/L for males). After 1 year of NA therapy, 75 patients (93.8%) had undetectable hepatitis B virus DNA levels. Mean post-treatment ALT levels were significantly lower than mean pretreatment levels (21.3 vs 30.0 U/L, respectively; P < .001). The proportion of patients with a normal ALT was also significantly higher after versus before treatment (71.2% vs 51.2%, respectively; P = .001). The strongest factors associated with ALT abnormality after 1 year of NA treatment were body mass index (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.05-1.54; P = .01) and ozone level (OR, 1.11; 95% CI, 1.02-1.22; P = .02). Among hepatitis B e antigen-negative CHB patients with relatively low viral loads, 1 year of NA treatment improved ALT levels after the adjustment for confounding factors and increased the proportion of patients with normal ALT levels. Air pollution affects the efficacy of ALT normalization.

Long-term exposure to ambient fine particulate matter (PM2.5) and associations with cardiopulmonary diseases and lung cancer in Taiwan: a nationwide longitudinal cohort study

BACKGROUND

Although a number of studies have reported on the health effects of fine particulate matter (PM2.5) exposure, particularly in North American and European countries as well as China, the evidence about intermediate to high levels of PM2.5 exposures is still limited. We aimed to investigate the associations between long-term exposure to PM2.5 and risk of cardiopulmonary disease incidence in Taiwan with intermediate levels of PM2.5 exposure.

METHODS

A cohort of Taiwanese adults, who participated in the 2001, 2005, 2009 and 2013 National Health Interview Surveys, was followed through 2016 to identify cardiopulmonary disease onset. Exposure to PM2.5 was estimated by incorporating a widespread monitoring network of air quality monitoring stations and microsensors. We used time-dependent Cox regression models to examine the associations between the PM2.5 exposures and health outcomes, adjusting for individual characteristics and ecological covariates. The natural cubic spline functions were used to explore the non-linear effects of the PM2.5 exposure.

RESULTS

A total of 62 694 adults from 353 towns were enrolled. Each 10-μg/m3 increase in 5-year average exposure to PM2.5 was associated with a 4.8% increased risk of incident ischaemic heart disease (95% CI: -3.3, 13.6), 3.9% increased risk of incident stroke (95% CI: -2.9, 11.1), 6.7% increased risk of incident diabetes (95% CI: 1.1, 12.7), 15.7% increased risk of incident lung cancer (95% CI: -0.9, 35.1) and 11.5% increased risk of incident chronic obstructive pulmonary disease (95% CI: -0.8, 25.2). The concentration-response curve showed that there was no statistical evidence of non-linearity for most of the disease outcomes except for ischaemic heart disease (P for non-linearity = 0.014).

CONCLUSIONS

Long-term exposure to intermediate levels of ambient PM2.5 was associated with cardiopulmonary health outcomes. Our study adds value to future application and national burden of disease estimation in evaluating the health co-benefits from ambient air pollution reduction policy in Asian countries.

Protein phosphatase 2A inactivation induces microsatellite instability, neoantigen production and immune response

Microsatellite-instable (MSI), a predictive biomarker for immune checkpoint blockade (ICB) response, is caused by mismatch repair deficiency (MMRd) that occurs through genetic or epigenetic silencing of MMR genes. Here, we report a mechanism of MMRd and demonstrate that protein phosphatase 2A (PP2A) deletion or inactivation converts cold microsatellite-stable (MSS) into MSI tumours through two orthogonal pathways: (i) by increasing retinoblastoma protein phosphorylation that leads to E2F and DNMT3A/3B expression with subsequent DNA methylation, and (ii) by increasing histone deacetylase (HDAC)2 phosphorylation that subsequently decreases H3K9ac levels and histone acetylation, which induces epigenetic silencing of MLH1. In mouse models of MSS and MSI colorectal cancers, triple-negative breast cancer and pancreatic cancer, PP2A inhibition triggers neoantigen production, cytotoxic T cell infiltration and ICB sensitization. Human cancer cell lines and tissue array effectively confirm these signaling pathways. These data indicate the dual involvement of PP2A inactivation in silencing MLH1 and inducing MSI.

Effects of short- and long-term exposure to atmospheric pollution on COVID-19 risk and fatality: analysis of the first epidemic wave in northern Italy

The effects of exposure to atmospheric pollution on the incidence and mortality due to COVID-19 have been studied but not for sulfur dioxide (SO₂) in most studies. However, most studies failed to consider important cofounding factors in the estimation of health effects of air pollution. The objective of the study was to assess the short- and long-term effects of air pollution on the COVID-19 risk and fatality in Lombardy and Veneto. Air pollutants were studied based on monitoring station information in Lombardy and Veneto from January 2013 to May 2020. The daily number of cases and deaths of COVID-19 were collected from the reports of the Italian Ministry of Health in Italy. A generalized linear model with the generalized estimating equation method was used to evaluate the effects of short- and long-term exposure to air pollution on the COVID-19 outbreak in Lombardy and Veneto. After adjusting for other covariates, we found that short-term exposure to PM_2.5 and PM₁₀ had a tendency to increase the incidence and mortality of COVID-19 than long-term exposure, while for other air pollutants, including SO₂ and NO₂, long-term exposure was more significant than short-term exposure. Both short- and long-term exposure of SO₂ resulted in increased health effects on COVID-19 pandemic. Our findings suggest that exposure to atmospheric pollution has a significant impact on COVID-19 pandemic and call for further researches to deeply investigate this topic.

Initial clinical experience of patient-specific QA of treatment delivery in online adaptive radiotherapy using a 1.5 T MR-Linac

Purpose. This study aims to evaluate the performance of a commercial 1.5 T MR-Linac by analyzing its patient-specific quality assurance (QA) data collected during one full year of clinical operation.Methods and Materials. The patient-specific QA system consisted of offline delivery QA (DQA) and online calculation-based QA. Offline DQA was based on ArcCHECK-MR combined with an ionization chamber. Online QA was performed using RadCalc that calculated and compared the point dose calculation with the treatment planning system (TPS). A total of 24 patients with 189 treatment fractions were enrolled in this study. Gamma analysis was performed and the threshold that encompassed 95% of QA results (T95) was reported. The plan complexity metric was calculated for each plan and compared with the dose measurements to determine whether any correlation existed.Results. All point dose measurements were within 5% deviation. The mean gamma passing rates of the group data were found to be 96.8 ± 4.0% and 99.6 ± 0.7% with criteria of 2%/2mm and 3%/3mm, respectively. T95 of 87.4% and 98.2% was reported for the overall group with the two passing criteria, respectively. No statistically significant difference was found between adaptive treatments with adapt-to-position (ATP) and adapt-to-shape (ATS), whilst the category of pelvis data showed a better passing rate than other sites. Online QA gave a mean deviation of 0.2 ± 2.2%. The plan complexity metric was positively correlated with the mean dose difference whilst the complexity of the ATS cohort had larger variations than the ATP cohort.Conclusions. A patient-specific QA system based on ArcCHECK-MR, solid phantom and ionization chamber has been well established and implemented for validation of treatment delivery of a 1.5 T MR-Linac. Our QA data obtained over one year confirms that good agreement between TPS calculation and treatment delivery was achieved.

Estimating ground-level PM2.5 levels in Taiwan using data from air quality monitoring stations and high coverage of microsensors

A widespread monitoring network of Airbox microsensors was implemented since 2016 to provide high-resolution spatial distributions of ground-level PM_2.5 data in Taiwan. We developed models for estimating ground-level PM_2.5 concentrations for all the 3 km × 3 km grids in Taiwan by combining the data from air quality monitoring stations and the Airbox sensors. The PM_2.5 data from the Airbox sensors (AB-PM_2.5) was used to predict daily mean PM_2.5 levels at the grids in 2017 using a semiparametric additive model. The estimated PM_2.5 level at the grids was further applied as a predictor variable in the models to predict the monthly mean concentration of PM_2.5 at all the grids in the previous year. The modeling-predicting procedures were repeated backward for the years from 2016 to 2006. The model results revealed that the model R² increased from 0.40 to 0.87 when the AB-PM_2.5 data were included as a nonlinear component in the model, indicating that AB-PM_2.5 is a significant predictor of ground-level PM_2.5 concentration. The cross-validation (CV) results demonstrated that the root of mean squared prediction errors of the estimated monthly mean PM_2.5 concentrations were smaller than 5 μg/m³ and the R² of the CV models of 0.79-0.88 during 2006-2017. We concluded that Airbox sensors can be used with monitoring data to more accurately estimate long-term exposure to PM_2.5 for cohorts of small areas in health impact assessment studies.

Source apportionment of mass concentration and inhalation risk with long-term ambient PCDD/Fs measurements in an urban area

This study applies a receptor model to quantify source contributions to ambient concentration of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and inhalation cancer risk in Taipei from 2003 through 2009. Seventeen PCDD/F congeners were used in the effective variance solution to the Chemical Mass Balance equations to estimate source-specific mass contributions and inhalation risks. The average total PCDD/F concentration was 0.611pg/Nm(3) (0.036pg I-TEQ/Nm(3)). Traffic emissions contributed the most to the PCDD/F concentration (55.7%), followed by waste incinerators (18.6%) and joss stick burning (9.6%). For the inhalation cancer risk, the average was 1.1×10(-6) with traffic, waste incinerators, and joss paper burning as the main contributors (67.3%, 19.4%, and 6.3%, respectively). The mass and risk contributions of waste incinerators decreased significantly from 2003 to 2009 and were higher at downwind sites than at upwind sites. Reducing PCDD/F emissions from traffic and waste incinerators would provide the greatest health benefit. Policies that reduce the uncontrolled burning of joss stick and joss paper also need to be implemented.

Association of short-term exposure to fine particulate matter and nitrogen dioxide with acute cardiovascular effects

This study evaluated whether exposure to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) is associated with cardiovascular effects by examining a panel of 89 healthy subjects in Taipei, Taiwan. The subjects received two health examinations approximately 8months apart in 2013. Brachial-ankle pulse wave velocity (baPWV), a physiological indicator of arterial stiffness, and high-sensitivity C-reactive protein (hsCRP), a biomarker of vascular inflammations, were measured during each examination. Two exposure assessment methods were used for estimating the subjects' exposure to PM2.5 and NO2. The first method involved constructing daily land use regression (LUR) models according to measurements collected at ambient air quality monitoring stations. The second method required combining the LUR estimates with indoor monitoring data at the workplace of the subjects. Linear mixed models were used to examine the association between the exposure estimates and health outcomes. The results showed that a 10-μg/m(3) increase in PM2.5 concentration at a 1-day lag was associated with 2.1% (95% confidence interval: 0.7%-3.6%) and 2.4% (0.8%-4.0%) increases in baPWV based on the two exposure assessment methods, whereas no significant association was observed for NO2. The significant effects of PM2.5 remained in the two-pollutant models. By contrast, NO2, but not PM2.5, was significantly associated with increased hsCRP levels (16.0%-37.3% in single-pollutant models and 26.4%-44.6% in two-pollutant models, per 10-ppb increase in NO2). In conclusion, arterial stiffness might be more sensitive to short-term PM2.5 exposure than is inflammation.

Modeling horizontal and vertical variation in intraurban exposure to PM2.5 concentrations and compositions

Land use regression (LUR) models are increasingly used to evaluate intraurban variability in population exposure to fine particulate matter (PM2.5). However, most of these models lack information on PM2.5 elemental compositions and vertically distributed samples. The purpose of this study was to evaluate intraurban exposure to PM2.5 concentrations and compositions for populations in an Asian city using LUR models, with special emphasis on examining the effects of having measurements on different building stories. PM2.5 samples were collected at 20 sampling sites below the third story (low-level sites). Additional vertically stratified sampling sites were set up on the fourth to sixth (mid-level sites, n=5) and seventh to ninth (high-level sites, n=5) stories. LUR models were built for PM2.5, copper (Cu), iron (Fe), potassium (K), manganese (Mn), nickel (Ni), sulfur (S), silicon (Si), and zinc (Zn). The explained concentration variance (R(2)) of the PM2.5 model was 65%. R(2) values were >69% in the Cu, Fe, Mn, Ni, Si, and Zn models and <44% in the K and S models. Sampling height from ground level was a significant predictor in the PM2.5 and Si models. This finding stresses the importance of collecting vertically stratified information on PM2.5 mass concentrations to reduce potential exposure misclassification in future health studies. In addition to traffic variables, some models identified gravel-plant, industrial, and port variables with large buffer zones as important predictors, indicating that PM from these sources had significant effects at distant places.

SNP array technology: an array of hope in breast cancer research

Breast cancer is the most common malignancy in women worldwide. The incidence of breast cancer in Malaysia is lower compared to international statistics, with peak occurrence in the age group between 50 to 59 years of age and mortality rates of 18.6%. Despite current diagnostic and prognostic methods, the outcome for individual subjects remain poor. This is in part due to breast cancers' wide genetic heterogeneity. Various platforms for genetics studies are now employed to determine the identity of these genetic abnormalities, including microarray methods like high density single-nucleotide-polymorphism (SNP) oligonucleotide arrays which combine the power of chromosomal comparative genomic hybridization (cCGH) and loss of heterozygosity (LOH) in the offering of higher-resolution mappings. These platforms and their applications in highlighting the genomic alteration frameworks manifested in breast carcinoma will be discussed.

Androgen decreases dopamine neurone survival in rat midbrain

Clinical studies show that men are more likely to develop disorders affecting midbrain dopaminergic pathways, such as drug addiction and Parkinson's disease (PD). Although a great deal of focus has been given to the role of oestrogen in the maintenance of midbrain dopaminergic pathways, little is known about how testosterone influences these pathways. In the present study, we used stereological analysis of tyrosine hydroxylase-immunoreactive (TH-IR) cell bodies to determine how testosterone influences the dopaminergic cell bodies of the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA). Rats and mice were castrated at postnatal day (PN) 60, and these midbrain cell populations were counted on PN 90. One month after castration, TH-IR cell number had increased in the SNpc and VTA of rats and mice. Replacement with testosterone or the non-aromatisable analogue dihydrotestosterone (DHT) in castrated animals reduced TH-IR cell number in the SNpc and VTA in rats. In mice, the decrease of TH-IR cell number with testosterone or DHT replacement was observed only in the SNpc. The apparent increase in TH-IR neurone number after castration is not explained by an increase in TH expression because the number of nondopaminergic cells (TH-immunonegative, TH-IN) did not decrease proportionally after castration. TH-IN cell number did not change after castration or hormone replacement in rat or mouse SNpc or VTA. These findings suggest that testosterone may play a suppressive role in midbrain dopaminergic pathways.

Oestrogen receptors enhance dopamine neurone survival in rat midbrain

Previous findings in our laboratory and elsewhere have shown that ovariectomy of rats in adulthood attenuates cocaine-stimulated locomotor behaviour. Ovarian hormones enhance both cocaine-stimulated behaviour and increase dopamine overflow after psychomotor stimulants. The present study aimed to determine whether ovarian hormones have these effects in part by maintaining dopamine neurone number in the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA) and to investigate the roles of specific oestrogen receptors (ERs) in the maintenance of mesencephalic dopamine neurones. To accomplish this goal, we used unbiased stereological techniques to estimate the number of tyrosine hydroxylase-immunoreactive (TH-IR) cell bodies in midbrain regions of intact, ovariectomised and hormone-replaced female rats and mice. Animals received active or sham gonadectomy on postnatal day 60 and received vehicle, 17beta-oestradiol (E(2)) or selective ER agonists propyl-pyrazole-triol (PPT, ERalpha) or diarylpropionitrile (DPN, ERbeta) for 1 month post-surgery. In both rats and mice, ovariectomy reduced the number of TH-IR cells in the SNpc and VTA. Replacement with E(2), PPT or DPN prevented or attenuated the loss observed with ovariectomy in both rats and mice. An additional study using ER knockout mice revealed that adult female mice lacking ERalpha had fewer TH-IR cells in midbrain regions than wild-type mice, whereas mice lacking ERbeta had TH-IR cell counts comparable to wild-type. These findings suggest that, although both ER subtypes play a role in the maintenance of TH-IR cell number in the SNpc and VTA, ERalpha may play a more significant role.

Serum sex hormone levels in pre- and postmenopausal breast cancer patients

INTRODUCTION

This study was conducted to determine the association between serum sex hormone levels and breast cancer.

METHODS

The study was conducted on newly-diagnosed breast cancer patients who had not received any treatment. Controls were women not known to have any breast disease or hormone-related tumours. Serum hormones were divided into quartiles. Logistic regression adjusting for age and race were done to calculate the odds ratio (OR) and 95 percent confidence interval (CI).

RESULTS

A total of 207 subjects were recruited; 73 premenopausal (37 cases, 36 controls) and 134 postmenopausal (68 cases and 66 controls) women. In the premenopausal women, only serum testosterone was positively associated with breast cancer (OR 1.72, 95 percent CI 0.40-7.40), but this was not a significant finding (p-value is 0.468). In the postmenopausal women, oestradiol, progesterone and testosterone were positively associated with breast cancer with a highest to lowest quartile OR of 1.48, 2.35 and 4.23 (95 percent CI 0.59-3.69, 1.11-4.95 and 1.52-11.78, respectively). The OR was significant for both progesterone and testosterone (p-values of 0.025 and 0.006, respectively).

CONCLUSION

There were no statistically significant findings among the premenopausal cases. In postmenopausal women, serum progesterone and testosterone levels were significantly associated positively with the odds of having breast cancer.

Screening and characterization of microbial inhibitors against eukaryotic protein phosphatases (PP1 and PP2A)

AIM

To identify novel microbial inhibitors of protein phosphatase 1 (PP1).

METHODS AND RESULTS

750 actinomycetes and 408 microfungi were isolated from Sabah forest soils and screened for production of potential PP1 inhibitors using an in vivo screening system, in which candidate inhibitors were identified through mimicking the properties of PP1-deficient yeast cells. Acetone extracts of two fungi, H9318 (Penicillium) and H9978 (non-Penicillium) identified in this way showed inhibitory activity towards both mammalian PP1 and PP2A in an in vitro phosphatase assay, while extract from H7520 (Streptomyces) inhibited PP2A but not PP1. Consistently, using a drug-induced haploinsufficiency test, strains with either reduced PP1 or PP2A function were hypersensitive to H9318 and H9978 extracts whereas only the latter strain showed hypersensitivity to H7250 extract. H9318 extract was fractionated using RP-HPLC into two active peaks (S1 and S2). A yeast strain with reduced PP1 function showed hypersensitivity to fraction S2 whereas a strain with reduced PP2A function was hypersensitive to fraction S1. However, S1 and S2 inhibited both PP1 and PP2A activities to a similar extent.

CONCLUSION

Three candidate PP inhibitors have been identified.

SIGNIFICANCE AND IMPACT OF THE STUDY

Further development may generate useful research tools and ultimately therapeutic agents.

Reaction of 5 and 6 year olds to dental injection after viewing the needle: pilot study

The aim was to evaluate the practice of hiding the needle prior to dental anesthesia administration to children. Fourteen 5 and 6 year olds received dental treatment in two sessions. The needle was shown in one session and hidden in the other. Eleven children were cooperative and 3 uncooperative irrespective of approach. The children's behavior correlated with fears expressed by the mothers. Our initial fndintgs do not support the practice of hiding the needle.

Preparation of nano-sized particles from collagen II by a high-voltage electrostatic field system

The pilot study describes a novel method for preparing nano-sized particles from collagen II using a high-voltage electrostatic field system. Observations from transmission electron microscopy showed that, in one of the cases, the nano-sized collagen II particles exhibited good sphericity, and the particles were in the range of 23.3+/-1.7 nm in diameter at the experimental setting of 3 kV cm(-1), for a 3 h treatment period and at 25 degrees C (with a collagen concentration of 0.2 mg ml(-1)). When the treatment temperature increased to 30 degrees C, the collagen II began to lose the tendency to form individually separated spherically shaped nano-particles. Moreover, a fibrous structure of collagen II was formed instead of a nano-particle shape at the temperature of 37 degrees C. This result is probably contributed to by an entropy-driven process that is termed fibrillogenesis, a larger force causing the collagen molecules to self-assemble and then form collagen fibrils. It is interesting to note that this is practically the first attempt to produce nano-particles directly from collagen II solution under the treatment of a high-voltage electrostatic field, together with a set of working parameters for the collagen concentration and low-temperature setting.

Demonstration of different modes of cell death upon herpes simplex virus 1 infection in different types of oral cells

The effects of Herpes simplex virus 1 (HSV-1) infection on five different types of oral cancerous cells (neck metastasis of gingival carcinoma (GNM) cells and tongue squamous cells of carcinoma (TSCCa) and non-cancerous cells (buccal mucosal fibroblasts (BF), gingival fibroblasts (GF), oral submucosal fibrosis cells (OSF)) and one type of non-oral cancerous cells (KB cells) were investigated. In HSV-1-infected cells the cell viability, CPE, viral antigens accumulation, caspase-3 activity, annexin V binding and DNA fragmentation were estimated. Three different forms or pathways of cell death were considered: apoptosis (the presence or rise of caspase-3 activity, DNA fragmentation and annexin V binding), slow cell death (the presence or rise of DNA fragmentation, the absence or decline of caspase-3 activity and annexin V binding), and necrosis (the absence of decline of caspase-3 activity, DNA fragmentation and annexin V binding). The viability of all cell types, except for KB cells, was reduced by the infection. CPE and viral antigens data demonstrated that all six types of cells could be infected with HSV-1. Upon HSV-1 infection there occurred (i) a classical apoptosis in GF cells, (ii) apoptosis in the early phase of infection and necrosis in the late phase of infection in GNM and TSCCa cells, (iii) slow cell death followed by necrosis in BF and OSF cells (however, these cells showed a different type of CPE), (iv) a classical slow cell death in KB cells. It is hypothesized that HSV-1 infection has a potential to induce several distinct pathways leading to cell death or several forms of cell death. Moreover, more than one pathway may be involved in the death of particular cell type. As HSV-1 was demonstrated to infect different oral and non-oral cells and cause different pathways or forms of cell death, the safety of using HSV-1 as a vector for gene therapy should be re-considered.

Curcumin inhibited the arylamines N-acetyltransferase activity, gene expression and DNA adduct formation in human lung cancer cells (A549)

It is well known that N-acetyltransferase (NAT) plays an important role in the arylamine metabolism. We analysed the response of A549 human lung cancer cells for N-acetylation of 2-aminofluorene (AF) to curcumin. After curcumin treatment, the NAT activity was examined by HPLC, AF-DNA adduct formation was examined by HPLC, and NAT gene expression by polymerase chain reaction were detected. The NAT activity in the human A549 cells and cytosols was suppressed by curcumin in a dose-dependent manner. The results also demonstrated that gene expression (NAT1 mRNA) in human lung A549 tumor cells was inhibited and decreased by curcumin. After the incubation of human lung A549 tumor cells with AF with or without curcumin co-treatment, the cells were recovered and DNA was prepared and hydrolyzed to nucleotides. The adducted nucleotides were extracted into butanol and analyzation of AF-DNA adducts was done by HPLC. The results also demonstrated that curcumin decreases AF-DNA adduct formation in the human lung A549 tumor cells.

Do the CK18 related proteins change in general in epithelial cancers?

The modulation of cytokeratin 18 during tumor transformation in hepatoma had been previously recognized through a series of biochemical and immunological approaches. Expression of cytokeratin 18 in transitional cell carcinoma comparing with hepatoma was investigated using the hepatoma transformation model. CK18 related molecules were found. In the present study, we design various epithelial cancers with the same model. CK18 related molecules were all evident. Therefore, we suggest that CK18 related proteins would play an important role in tumorigenesis of epithelial cancers.

Co-expression of VEGF-C and its receptors, VEGFR-2 and VEGFR-3, in endothelial cells of lymphangioma. Implication in autocrine or paracrine regulation of lymphangioma

Lymphangioma has long been thought of as congenital malformations resulting from the failure of lymphatic vessels communicating with the venous system in the fetal period. Alternatively, it is proposed to be true neoplasm originated from the transformation of lymphatic endothelia. To extend the molecular basis of the pathogenesis of lymphangioma, we have characterized the expression of vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) in 29 cases of lymphangioma by RNA in situ hybridization. Endothelial cells of lymphangioma co-express transcripts of VEGF-C and its receptors VEGFR-3 (Flt4) and VEGFR-2 (Flk1), which are not detectable in the adjacent connective tissue. In contrast, there is little or no expression of VEGF-C, VEGFR-3, and VEGFR-2 mRNA in endothelial cells of hemangiomas, angiosarcomas, or normal lymphatic vessels of the small or large intestines. The results suggest that VEGF-C and its receptors may take active parts in the formation of lymphangioma by autocrine or paracrine regulation.

Herpetic neuralgia. Use of combination therapy for pain relief in acute and chronic herpes zoster

Herpes zoster (shingles) is a localized infection that begins in the dorsal root ganglla of the cranial or spinal nerves and spreads as a rash over the corresponding dermatome. It usually is caused by reactivation of latent varicella-zoster virus remaining from childhood chicken pox. Postherpetic neuralgia (PHN) is a chronic neuropathic pain syndrome that occurs as a complication of shingles, most commonly in older persons. Acute zoster and PHN can be severe conditions associated with impaired sleep, decreased appetite, depression, anxiety disorder, and diminished libido. Management of zoster-related pain should begin as soon as possible after the onset of symptoms. Combination therapy--including antiviral, antidepressant, corticosteroid, opioid, and topical agents--provides the most effective analgesia.

Ellagic acid inhibited 2-aminofluorene and p-aminobenzoic acid acetylation by mononuclear leucocytes from Sprague-Dawley rats

Following exposure of rats to the arylamine carcinogen 2-aminofluorene, DNA-carcinogen adducts were found in the liver and bladder target tissues, and also in circulating leucocytes. This work investigated the effect of ellagic acid on arylamine (2-aminofluorene and p-aminobenzoic acid) acetylations in rat leucocytes. Evidence is presented that rat mononuclear leucocytes are capable of acetylating 2-aminofluorene and p-aminobenzoic acid. Both lymphocytes and monocytes were able to acetylate arylamines during 18 h of culture. Cultured lymphocytes produced about twice as much N-acetyl-2-aminofluorene from 2-aminofluorene and 2.2-fold as much N-acetyl-p-aminobenzoic acid from p-aminobenzoic acid as monocytes. After cotreatment with ellagic acid the lymphocyte and monocyte cultures indicated that ellagic acid reduced 2-aminofluorene acetylation.

Surface modification of natural rubber latex films via grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion

Natural rubber (NR) latex films with surface grafted poly(ethylene glycol) (PEG) chains were prepared by UV-induced graft copolymerization of methoxy poly(ethylene glycol) monomethacrylate (PEGMA) onto the plasma-pretreated NR latex films. PEGMA macromononers of different molecular weights were used. The UV-induced graft copolymerization of PEGMA onto the plasma-pretreated NR latex films was also explored with PEGMA of different macromonomer concentrations and with different UV graft copolymerization time. The surface microstructures and compositions of the PEG-modified NR latex films were characterized by contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) measurements. In general, higher macromonomer concentration and longer UV graft copolymerization time led to a higher graft yield. Water contact angle measurements revealed that the hydrophilicity of the NR latex film surface was greatly enhanced by the grafting of the PEG chains. The NR surface with a high density of grafted PEG was very effective in reducing protein adsorption and platelet adhesion. A lower graft concentration of the high-molecular-weight PEG was more effective than a high graft concentration of the low-molecular-weight PEG in reducing protein adsorption and platelet adhesion.

Effects of berberine on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adduct formation in human leukemia cells

Berberine is an alkaloid occurring in the plant genera Berberis and Coptis. Although berberine had been demonstrated to have antineoplastic function by inhibiting DNA-synthesis in activated lymphocytes, there is no available information to address berberine affects on human leukemia cell N-acetyltransferase (NAT) activity and 2-aminofluorene (AF)-DNA adduct formation. Thus, berberine was tested for inhibition of arylamine NAT activity and AF-DNA adduct formation in human leukemia cells. The NAT activity was measured by a high performance liquid chromatography assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and the remaining AF and p-aminobenzoic acid (PABA). The NAT activity and AF-DNA adduct formation in human leukemia cells were inhibited by berberine in a dose-dependent manner, i.e. the higher the concentration of berberine, the higher the inhibition of NAT activity and AF-DNA adduct. The data also indicate that berberine decreased the apparent values of Km and Vmax from human leukemia cells in both cytosol and intact cells.

Fear of pain in orofacial pain patients

In the present study, we examined whether fear of pain, dental fear, general indices of psychological distress, and self-reported stress levels differed between 40 orofacial pain patients and 40 gender and age matched control general dental patients. We also explored how fear of pain, as measured by the Fear of Pain Questionnaire-III (J Behav Med 21 (1998) 389), relates to established measures of psychological problems in our sample of patients. Finally, we examined whether fear of pain uniquely and significantly predicts dental fear and psychological distress relative to other theoretically-relevant psychological factors. Our results indicate that fear of severe pain and anxiety-related distress, broadly defined, are particularly elevated in orofacial pain patients relative to matched controls. Additionally, fear of pain shares a significant relation with dental fear but not other general psychological symptomology, and uniquely and significantly predicts dental fear relative to other theoretically-relevant variables. Taken together, these data, in conjunction with other recent studies, suggest greater attention be placed on understanding the fear of pain in orofacial pain patients and its relation to dental fear and anxiety.

Use of sonography and radioisotope renography to diagnose hydronephrosis in patients with spinal cord injury

OBJECTIVE

To study the accuracy of sonography and radioisotope renography in detecting hydronephrosis in patients with spinal cord injury (SCI).

DESIGN

Prospective, blinded comparison study.

SETTING

Rehabilitation hospital affiliated with a medical college.

PARTICIPANTS

One hundred and nine patients with SCI (21 women, 88 men) participated.

INTERVENTIONS

Comprehensive urologic examinations including clinical evaluation, laboratory tests, intravenous urography (IVU), sonography, radioisotope renography (renal scan), voiding cystourethrography, and cystometry. The findings at sonography and renal scan were separately compared with the final diagnosis interpreted by IVU and clinical findings.

MAIN OUTCOME MEASURES

Effective renal plasma flow, pyelocaliectasis, and positive and negative predictive value.

RESULTS

A total of 235 kidneys were analyzed. Sonography correctly excluded the presence of hydronephrosis in 173 of 192 nonobstructed kidneys. Sonograms were interpreted as positive in 41 of 43 kidneys with documented hydronephrosis. Renal scan correctly excluded 161 nonobstructed kidneys. The renal scan detected 39 of 43 kidneys with hydronephrosis. The sensitivity of sonography was.96 with a specificity of.90. Renal scan reached a sensitivity of.91 with a specificity of.84.

CONCLUSION

Sonography and renal scan are safe, sensitive, and specific for detecting hydronephrosis. Combined use of both methods appears to be a reliable alternative to IVU in the long-term follow-up for patients with SCI with neurogenic bladder dysfunction.

A Combined Pore Blockage and Cake Filtration Model for Protein Fouling during Microfiltration

Previous studies of protein fouling during microfiltration have shown significant discrepancies between filtrate flux data and predictions of the classical pore blockage, pore constriction, and cake filtration models. A new mathematical model was developed for the filtrate flux which accounts for initial fouling due to pore blockage and subsequent fouling due to the growth of a protein cake or deposit over these initially blocked regions. The model explicitly accounts for the inhomogeneity in the cake layer thickness over different regions of the membrane arising from the time-dependent blockage of the pore surface. The model was shown to be in excellent agreement with experimental data obtained during the stirred cell filtration of bovine serum albumin solutions through polycarbonate track-etched microfiltration membranes over the entire course of the filtration. The model provides a smooth transition from the pore blockage to cake filtration regimes, eliminating the need to use different mathematical formulations to describe these two phenomena. In addition, the model provides the first quantitative explanation for some of the unusual observations reported previously in investigations of protein microfiltration. The results provide important insights into the underlying mechanisms of protein fouling during microfiltration. Copyright 2000 Academic Press.

Effects of ellagic acid by oral administration on N-acetylation and metabolism of 2-aminofluorene in rat brain tissues

Numerous studies have demonstrated that the Acetyl Coenzyme A-dependent arylamine NAT enzyme exist in many tissues of experimental animals including humans, and that NAT has been shown to be exist in mouse brain tissue. Increased NAT activity levels are associated with increased sensitivity to the mutagenic effects of arylamine carcinogens. Attenuation of liver NAT activity is related to breast and bladder cancer processes. Therefore, the effects of ellagic acid (EA) on the in vitro and in vivo N-acetylation of 2-aminofluorene (AF) were investigated in cerebrum, cerebellum and pineal gland tissues from male Sprague-Dawley rats. For in vitro examination, cytosols with or without EA (0.5-500 microM) co-treatment decreased 7-72%, 15-63% and 10-78% of AF acetylation for cerebrum, cerebellum and pineal gland tissues, respectively. For in vivo examination, EA and AF at the same time treated groups with all 3 examined tissues did show significant differences (the changes of total amounts of AF and AF metabolites based on the Anova analysis) when compared to the ones without EA cotreatment rats. The pretreatment of male rats with EA (10 mg/kg) 24 hr prior to the administration of AF (50 mg/kg) (one day of EA administration suffice to induce large changes in phase II enzyme activity) resulted in a 76% decrease in total AF and metabolites in pineal gland but did not show significant differences in cerebrum and cerebellum tissues. This is the first demonstration to show that EA decreases the N-acetylation of carcinogens in rat brain tissues.

The expression of cytokeratin 18 in transitional cell carcinoma comparing with hepatoma

The epithelium in kidneys and urinary bladders contain CK18 as in liver cells. The modulation of cytokeratin 18 during tumor transformation in hepatoma had been previously recognized through a series of biochemical and immunological approaches. A 14 KD hepatoma related molecules was found in the previous studies. We would like to utilize the hepatoma transformation model to study the changes in CK18 in transitional cell carcinoma, using immunoblotting and western blotting techniques. The result is that transitional cell carcinoma retain their CK18 molecule. Furthermore, CK18 related molecules similar to those seen in hepatoma also present in transitional cell carcinoma. The conclusions are transitional cell carcinoma contains CK18 related proteins similar to those seen in hepatoma tissues. We suggest that this element would be responsible for the change during the malignant transformation processes.

Stabilizing of cytokeratin in PLC/PRF/5 cells

There are two sorted groups of cytokeratin 18 (CK18) in forms of assembly and disassembly in PLC/PRF/5 cells. A subcellular shifting is found in association with conditions of microtubule networks. The finding shows that CK18 mostly in forms of assembly, when microtubule networks are in status. The result also reveals that CK18 is relatively in forms of disassembly, while microtubule networks are disrupted in steps. It indicates that intact microtubule networks are probably a stabilizing factor of assembled CK18. It implies that CK18 is not a stable molecule when the cell is under environmental stress.

Spider-mite problems and control in Taiwan

Problems with spider mites first appeared in Taiwan in 1958, eight years after the importation of synthetic pesticides, and the mites evolved into major pests on many crops during the 1980s. Of the 74 spider mite species recorded from Taiwan 10 are major pests, with Tetranychus kanzawai most important, followed by T. urticae, Panonychus citri, T. cinnabarinus, T. truncatus and Oligonychus litchii. Most crops suffer from more than one species. Spider mites reproduce year-round in Taiwan. Diapause occurs only in high-elevation areas. Precipitation is the most important abiotic factor restricting spider-mite populations. Control is usually accomplished by applying chemicals. Fifty acaricides are currently registered for the control of spider mites. Acaricide resistance is a serious problem, with regional variation in resistance levels. Several phytoseiid mites and a chrysopid predator have been studied for control of spider mites with good effect. Efforts to market these predators should be intensified so that biological control can be a real choice for farmers.

Electrokinetic Behavior of Palm Oil Emulsions in Dilute Electrolyte Solutions

The effect of metal cations, both nonhydrolyzable and hydrolyzable, on the zeta potential of palm olein emulsions stabilized by the nonionic emulsifier, polyoxyethylene nonyl phenyl ether, was investigated as a function of pH and cation concentrations, respectively. The oil drops were found to be negatively charged in the presence of simple mono- and divalent cations. Charge reversal of the oil drops was observed when hydrolyzable cations (Zn2+, Cu2+, Fe3+, and Al3+) were used and the behavior is strongly dependent on the type of cation, its concentration, and the pH of the dispersion. The results are discussed in terms of current theories of electrophoresis and adsorption-precipitation at interfaces. The chemical free energies of adsorption of the cations were calculated. Copyright 1999 Academic Press.

Effects of berberine on arylamine N-acetyltransferase activity in human bladder tumour cells

Berberine was used to determine inhibition of arylamine N-acetyltransferase (NAT) activity in human bladder tumour cells. The NAT activity was measured by HPLC assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and remaining 2-aminofluorene (AF) and p-aminobenzoic acid (PABA). Two assay systems were performed, one with cellular cytosols, the other with intact bladder tumour cell suspensions. The NAT activity in human bladder tumour cells was inhibited by berberine in a dose-dependent manner, that is, the higher the concentration of berberine, the higher the inhibition of NAT activity. The values of apparent Km and Vmax calculated from cytosol NAT and intact cells were also decreased by berberine. This report is the first demonstration to show berberine did affect human bladder tumour cell NAT activity.

Bladder shape impact on the accuracy of ultrasonic estimation of bladder volume

OBJECTIVE

Variations in bladder shape can lead to errors in ultrasonic estimation of the bladder volume. The purposes of this study were to compare the accuracies of various formulas to estimate bladder volume from sonographic measurements and to assess the impact of bladder shape on the accuracy of bladder volume estimation.

STUDY DESIGN

Twenty-four healthy volunteers (13 men, 11 women) and 55 spinal cord injury patients (48 men, 7 women) underwent ultrasonographic measurements of dimensions before and after voiding. Bladder shape was classified as cuboid, ellipsoid, or triangular prism. Ten formulas from the literature were applied to estimate bladder volume, using the volume voided or catheterized as the standard, and then linear regression was used to obtain optimal correction coefficients for the whole data set as well as each of the three bladder shapes.

SETTING

Rehabilitation hospital affiliated with a medical college.

RESULTS

The most accurate of the 10 formulas tested was height (H) X transverse depth (Dt) x weight (W) x 0.7 (mean error 17.4%+/-11.6%). Linear regression analysis yield optimal correction coefficients of .72 for the whole data set and .89, .81, and .66 for cuboidal, ellipsoid, and triangular prism-shaped bladders, respectively. The mean error for the estimation of bladder volume using .72 as the correction coefficient was 16.9%+/-11.9% and decreased to 12.7%+/-10.1% (p < .0001, paired t test) when the bladder shape was taken into account.

CONCLUSION

Using bladder shape for reference and applying the corresponding correction coefficient to volume calculations will improve the accuracy of the estimation.

Rhein affects arylamine N-acetyltransferase activity in Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene and p-aminobenzoic acid were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without specific concentrations of rhein co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there was decreased NAT activity associated with increased levels of rhein in H. pylori cytosols. Inhibition of growth studies from H. pylori demonstrated that rhein elicited dose-dependent bacteriostatic activity in H. pylori cultures: i.e. the greater the concentration of rhein, the greater the inhibition of growth to H. pylori. For the cytosol and intact bacteria examination, the apparent values of Km and Vmax were decreased after co-treatment with 40 microM rhein. This report is the first demonstration of rhein inhibition of arylamine N-acetyltransferase activity and rhein inhibition of growth in the bacterium H. pylori.

Needle aspiration cytology of metastatic high-grade transitional-cell carcinomas of the urinary tract

We reviewed 4 cases of high-grade transitional-cell carcinoma (TCC) of the urinary tract with solitary pulmonary metastases that were studied by transthoracic needle aspiration biopsy cytology. There were two grade II and two grade III TCCs. The two grade II tumors yielded, in needle aspirates, syncytial tumor-cell clusters showing ill-defined, granular cytoplasm and slightly pleomorphic nuclei with inconspicuous nucleoli. In one case the tumor-cell cluster showed a focal acinar arrangement, mimicking cells of an adenocarcinoma. In both cases the electron microscopy (EM) study of aspirated tumor cells revealed epithelial cells with well-formed cell junctions, intracytoplasmic vesicles, apical short microvilli, and focal interdigitation of lateral cell membranes, suggesting a urothelial neoplasm. The two grade III TCCs yielded, in needle aspirates, pleomorphic malignant cells singly and in small clusters, showing well-defined, granular cytoplasm and pleomorphic nuclei containing prominent nucleoli, suggesting a poorly differentiated adenocarcinoma or an anaplastic large-cell carcinoma. By EM examination the aspirated tumor cells from one case revealed well-formed cell junctions, intracytoplasmic vesicles, poorly formed microvilli, and focal interdigitation of lateral cell membranes, suggesting a urothelial differentiation. In the other case the tumor cells were pleomorphic cells with occasional cell junctions and no ultrastructural features as seen in the other 3 cases of TCC. The tumor cells from the two grade II TCCs showed strong immunopositive reaction with keratin 7 antibody and weakly positive reaction with carcinoembryonic antigen antibody (CEAA), while those of the two grade III TCCs displayed only a weak and focal immunopositive staining with keratin 7 antibody and strong reaction with CEAA.

Rhein affects arylamine N-acetyltransferase activity in Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene and p-aminobenzoic acid were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without specific concentrations of rhein co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there was decreased NAT activity associated with increased levels of rhein in H. pylori cytosols. Inhibition of growth studies from H. pylori demonstrated that rhein elicited dose-dependent bacteriostatic activity in H. pylori cultures: i.e. the greater the concentration of rhein, the greater the inhibition of growth to H. pylori. For the cytosol and intact bacteria examination, the apparent values of Km and Vmax were decreased after co-treatment with 40 microM rhein. This report is the first demonstration of rhein inhibition of arylamine N-acetyltransferase activity and rhein inhibition of growth in the bacterium H. pylori.

Aloe-emodin effects on arylamine N-acetyltransferase activity in the bacterium Helicobacter pylori

Arylamine N-acetyltransferase (NAT) activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (AF) were determined in H. pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without different concentrations of aloe-emodin co-treatment showed different percentages of AF and PABA acetylation. The data indicate that there was decreased NAT activity associated with increased aloe-emodin in H. pylori cytosols. Inhibition of growth study from H. pylori demonstrated that aloe-emodin elicited dose-dependent growth inhibition in H. pylori cultures. The report is the first finding of aloe-emodin inhibition of arylamine NAT activity in a strain of H. pylori.

Microprocessor based spatial TENS (transcutaneous electric nerve stimulator) designed with waveform optimality for clinical evaluation in a pain study

A microprocessor based TENS device is developed which utilizes a spatial procedure in the administration of electrical fields to actively interfere with pain signals reaching the brain. This unusual design also has the advantage of requiring the frequency characteristics of the electrical waveform produced to be optimally tuned to the mechanical impedance properties of the skin/tissue. Hence a much more efficient procedure for the transfer of electrical energy from the TENS device to the human tissue is provided. Data are presented involving patients from the Dayton VA Medical Center in Ohio, USA being tested with this new microprocessor system compared to the treatment obtained via a traditional stimulator.

Light-induced changes in frog pineal gland N-acetyltransferase activity

N-Acetyltransferase (NAT) activity was determined in the pineal gland of frogs (Rana tigrina) of different ages using 2-aminofluorene and p-aminobenzoic acid as substrates, and assayed by high-pressure liquid chromatography. Frogs of different ages were either killed during the light phase or exposed to darkness or light for 1 min during the dark phase of the lighting cycle, then returned to their cages in darkness for 30 min before being killed. The pineal gland NAT activity of 1-month-old frogs was inhibited when the animal was nocturnally exposed to 1 min of light. Nocturnal light exposure did not inhibit NAT activity in 1-month-old frogs, even though these animal displayed clear light-dark differences in pineal gland NAT activity. Nocturnal light exposure did not inhibit night-time levels of NAT activity in 1-month-old animals which had been bilaterally enucleated, thus suggesting that this effect is retinally mediated. Pretreatment of 1-month-old and 6-month-old animals with isoproterenol (a beta-adrenoceptor agonist drug) prevented the nocturnal light-induced inhibition of NAT activity. From the different sensitivity of 1-month-old and 6-month-old animals to different intensities or durations of nocturnal light exposure it was found that the duration or intensity of light exposure was not able to inhibit nocturnal NAT activity. The NAT activity was at least 4-5-fold greater in 1-month-old frogs than in 6-month-old frogs. This is the first demonstration of the retino-pineal gland pathway that appears to produce light-induced changes in pineal glands of frogs 1-month-old or older, but this pathway only functions in 1-month-old frogs, and does not appear to function in 6-month-old frogs.

The alteration of cytokeratin 18 molecule and its mRNA expression during tumor transformation in hepatoma

The cytokeratin 18 related molecules of human hepatocellular carcinoma have been previously recognized through a series of biochemical and immunological approaches. It is suggested that these molecules undergo modulation from human hepatocyte cytokeratin 18. To prove whether these molecules are produced by modulation or protein degradation, we checked the cytokeratin profile of human hepatoma cell line PLC/PRF/5 with the methods used before. These results revealed that the PLC cells have the same cytokeratin 18 related molecules as human hepatocellular carcinoma tissue. The gene expression of the cytokeratin 18 in non-tumor liver tissues, hepatocellular carcinoma and PLC/PRF/5 cells were investigated. First, the mRNAs of non-tumor liver tissues, hepatocellular carcinoma tissues and PLC/PRF/5 cells were collected by the acid guanidinium thiocyanate phenol chloroform method. After transcription into cDNA by reverse transcriptase polymerase chain reaction, the cDNAs of each specimen were amplified by PCR and then digested by SmaI and BamHI restriction enzymes. The digested cDNA fragments were electrophoresed in agarose gel and the base pairs were found to be the same in length between neoplastic and non-neoplastic hepatocytes.

Evidence for arylamine N-acetyltransferase in the nematode Anisakis simplex

N-Acetyltransferase activities with p-aminobenzoic acid and 2-aminofluorene were determined in Anisakis simplex, a nematode found in the intestine of the salt water fish Trichiurus lepturus. The N-acetyltransferase activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. The N-acetyltransferase activity from a number of Anisakis simplex whole tissue homogenizations was found to be 2.89 +/- 0.52 nmol/min per mg for 2-aminofluorene and 2.54 +/- 0.45 nmol/min per mg for p-aminobenzoic acid. The K(m) and Vmax values obtained were 1.06 +/- 0.69 mM and 9.34 +/- 1.94 nmol/min per mg for 2-aminofluorene, and 2.25 +/- 0.10 mM and 14.44 +/- 0.7 nmol/min per mg for p-aminobenzoic acid. The optimal pH value for the enzyme activity was pH 8.0 for both substrates tested. The optimal temperature for enzyme activity was 37 degrees C for both substrates. The N-acetyltransferase activity was inhibited by iodoacetamide: at 0.25 mM iodoacetamide, activity was reduced 50% and 1.0 mM iodoacetamide inhibits activity more than 90%. Among a series of divalent cations and salts, Cu2+ and Zn2+ were demonstrated to be the most potent inhibitors. This is the first demonstration of acetyl CoA/arylamine N-acetyltransferase activity in a nematode and extends the number of phyla in which this activity has been found.

Kinetics of acetyl coenzyme A:arylamine N-acetyltransferase from rapid and slow acetylator frog tissues

N-acetyltransferase (NAT) activity was determined in 100 frog (Rana tigrina) livers using 2-aminofluorene and p-aminobenzoic acid as substrates. Overall, the liver NAT activity of the 50 females was higher than the liver NAT activity of the 50 males. The activities (mean +/- SD) of NAT from the bladder, blood, colon, and liver of males was 0.30 +/- 0.11, 0.05 +/- 0.03, 0.09 +/- 0.05, and 0.93 +/- 0.56 nmol/min/mg protein for the acetylation of aminofluorene and 0.29 +/- 0.06, 0.36 +/- 0.04, 0.26 +/- 0.02, and 0.32 +/- 0.14 nmol/min/mg protein for the acetylation of p-aminobenzoic acid. In the bladder, blood, colon, and liver from female frogs, the activities obtained were 1.00 +/- 0.41, 0.52 +/- 0.07, 0.08 +/- 0.05, and 1.27 +/- 0.49 nmol/min/mg protein for aminofluorene and 0.34 +/- 0.12, 0.36 +/- 0.04, 0.34 +/- 0.07, and 0.48 +/- 0.21 nmol/min/mg protein for p-aminobenzoic acid. Kinetic constants for arylamine NAT activity in the blood, liver, bladder, and colon from frogs with rapid, intermediate, and slow acetylator activities were determined. KM and Vmax values for aminofluorene were 2- to 6-fold higher for liver than for the other tissues. KM and Vmax values for p-aminobenzoic acid showed a smaller variation among the tissues examined, with values obtained for the liver and bladder being somewhat higher than the values for the blood and colon. An apparent KM difference for aminofluorene was found in the liver from frogs with high and low acetylator activity. Based on the aminofluorene NAT activity of liver, there seems to be a polymorphism in NAT activity with 4 rapid, 21 intermediate, and 75 slow acetylators among the 100 frogs assayed. Distribution of acetylator phenotypes was similar among the 50 males and 50 females in this study. This is the first demonstration of acetyl coenzyme A:arylamine NAT activity in an amphibian and could lead to the development of a frog model for monitoring the effect of pollution of wetland environments on native species.

Application of radioisotope renography with technetium-99m mercaptoacetyltriglycine on patients with spinal cord injuries

The effectiveness of radioisotope renography with Technetium-99m (Tc-99m) mercaptoacetyltriglycine (MAG3) to provide possible routine urological follow-up was evaluated for the spinal cord injury (SCI) population. Sixty-six SCI patients were examined with radioisotope renography and renal ultrasonography. Excretory urography was done on 46 patients and voiding cystourethrography was done on 46 patients and voiding cystourethrography was done on 59 patients. The time-activity curve patterns of renography were classified into six groups. Curves A were normal. Curves B and C showed various excretion delay but normal effective renal plasma flow (ERPF). Curves D, E, and F showed definite decreased ERPF and excretion delay of different severity. The respective incidence of upper urinary tract complications were 12.0% (10/83) for A, 68.2% (15/22) for B, 100% (4/4) for C, 100% (8/8) for D, 100% (11/11) for E, and 100% (4/4) for F curves. The sensitivity of radioisotope renography was 83.9%, and the specificity was 92.0% in detecting the upper urinary tract complications. There was no adverse effect after 80 renography examinations on 66 SCI patients. As excretion delay occurred in the earlier stage of renal dysfunction, followed by decrease of ERPF, the abnormal time-activity curves can be sensitive indicators to subject SCI patients with early renal deterioration for further urodynamic and morphological studies. For patients with normal renograms, conventional uroradiological studies are not recommended because they are more invasive, cumbersome, and have more side effects as well as higher radiation exposure. We found that radioisotope renography with Tc-99m MAG3 is a safe, noninvasive, sensitive, and valuable urological screening test for SCI patients.