Effect of the epicardial fat volume on the outcomes after a left atrial posterior wall isolation in addition to pulmonary vein isolation in patients with persistent atrial fibrillation

Background

While the effect of a circumferential pulmonary vein isolation (CPVI) alone is unsatisfactory, that of an additional electrical posterior wall box isolation (POBI) is controversial in persistent atrial fibrillation (PeAF) patients. Increased epicardial adipose tissue (EAT) is associated with higher recurrence rates after AF catheter ablation (AFCA).

Purpose

We investigated the possible effects of a POBI on rhythm outcomes with varying EAT volumes.

Methods

We included 1,187 patients with PeAF undergoing a de novo AFCA (79.6% male, median age 60 years) into two groups including those receiving a CPVI alone (n=687) and those an additional POBI (n=500). The rhythm outcomes at two years post-AFCA were compared in subgroups stratified by the total EAT volume using propensity overlap weighting.

Results

A reduced total EAT volume was linearly associated with more favorable rhythm outcomes for an additional POBI treatment than for a CPVI alone (P for interaction=0.002). Among the patients with smaller EAT volumes (≤116.23 ml, the median value, n=594), an additional POBI was associated with a reduced AF recurrence risk as compared to a CPVI only (weighted hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.56–0.99; weighted log-rank P=0.039). In contrast, among the remaining 593 patients with greater EAT volumes (>116.2 3mL), there was no difference in the AF recurrence risk between an additional POBI and CPVI alone (weighted HR 1.13, 95% CI 0.84–1.52; weighted log-rank P=0.410). Among 185 patients with a repeat ablation, the POBI reconnection rate tended to be higher in the large EAT group (75.0%) than small EAT group (55.4%, P=0.060).

Conclusion

While PeAF patients with a smaller EAT volume averted AF recurrence by an additional POBI after the CPVI, no benefit of the POBI was observed in those with a greater EAT volume. The EAT volume might identify AF patients likely to benefit from linear ablation in addition to the CPVI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Ministry of Science, ICT & Future Planning (MSIP)Korean Ministry of Health and Welfare

Artificial intelligence-predicted poor responders to catheter ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Although atrial fibrillation (AF) catheter ablation is effective for rhythm control, in some patients it is hard to maintain sinus rhythm in spite of repeated AF catheter ablation (AFCA) procedures and anti-arrhythmic drugs (AADs). We explored the pre-procedural predictors for poor responders to AFCA and tested whether artificial intelligence (AI) assists the prediction of poor responders in the independent cohort by determining the invasive parameters.

Methods

Among 1,214 patients who underwent AFCA and regular rhythm follow-up for 56.2 ± 33.8 months (59 ± 11 years, 73.5% male, 68.6% paroxysmal AF), we differentiated 92 poor responders defined as those with sustained AF despite repeat AFCAs, AADs, or electrical cardioversion. Using the Youden index, we identified advanced LA remodeling with lower LA voltage under 1.109mV. AI model, which was derived from development cohort using medical record, was applied to predict LA voltage <1.109mV in the independent cohort (n = 634, poor responders = 24) using a grad-cam score.

Results

The patients with lower LA voltage under 1.109mV showed significantly poorer rhythm outcomes (Log-rank p < 0.001). We determined invasive parameter LA voltage by using the multiple variables (age, female sex, AF type, CHA2DS2VASc score, LA dimension, E/em, hemoglobin, PR interval) and achieved relatively good prediction power of AI for LA voltage <1.109mV (AUC = 0.734, sensitivity 0.729, specificity 0.643) in the test cohort. In the independent cohort, the AI model showed good discrimination power for poor responders (AUC 0.751, p < 0.001) by estimating LA voltage, which is an invasive variable. The patients with predicted lower LA voltage (grad-cam score <0) showed poorer rhythm outcome after active rhythm control (Log-rank p < 0.001)

Conclusions

The patients with advanced atrial remodeling with low LA voltage, which can be predicted by an AI, showed significantly higher recurrence of AF after AFCA with AADs or cardioversion. AI may assist to select these poor responder patients before the AFCA procedure. Abstract Figure.

Left atrial wall stress and the outcome of catheter ablation for atrial fibrillation: artificial intelligence-based prediction of clinical outcome

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Left atrial (LA) wall stress (LAW-str) may contribute to the mechanism of atrial fibrillation (AF).

Purpose

We explored the clinical characteristics and the rhythm outcome of AF depending on LAW-str among the patients who underwent AF catheter ablation (AFCA). We also tested whether artificial intelligence (AI) properly estimate LAW-str without invasive parameters.

Methods

We included 2223 patients (72.8% male, 59.0 [52.0–67.0] years old, 28.7% with persistent AF [PeAF]) who underwent radiofrequency catheter ablation (RFCA). LAW-str was calculated by the Law of Laplace using LA diameter (echocardiogram), peak LA pressure, and mean LA wall thickness (computed tomography) measured by customized software. Based on the quartile (Q1–4) or AI-estimated values of LAW-str, we compared clinical characteristics and rhythm outcome.

Results

LAW-str was independently associated with PeAF (p < 0.001), diabetes (p = 0.012) and vascular disease (p = 0.002), body mass index (p < 0.001), E/Em (p < 0.001), and mean LA voltage (p < 0.001). During 26.0 (12.0–52.0) months follow-up, clinical recurrence of AF was significantly higher in the Q4 of LAW-str group (log rank p = 0.001). LAW-str was independently associated with clinical recurrence after AFCA (HR 1.001 [1.000–1.002], p = 0.013). AI-based model using non-invasive parameters predicted Q4 of LAW-str with area under the curve (AUC) 0.734, which was similar to logistic regression based predictive model using all data including invasive parameters (AUC 0.726). Patients in Q4 of LAW-str showed consistently worse rhythm outcome regardless of the type of AF, sex, or AI-based prediction (p = 0.039).

Conclusions

The LAW-str seems to be associated with rhythm outcome of AFCA and AI can predict this complex parameter with moderate accuracy. TableMultivariateβ (95% CI)PPersistent AF31.08 (21.77-40.39)<0.001Diabetes mellitus15.36 (3.35-27.38)0.012Vascular disease22.27 (8.4-36.14)0.002Body mass index2.91 (1.53-4.29)<0.001E/Em4.95 (3.87-6.02)<0.001Mean LA voltage-22.24 (-27.96–16.52)<0.001Linear regression analysis for clinical variables predictive of LA wall stress (10^3 dyn/cm2).Abstract Figure. AF recurrence by LAW-str, AI-prediction

Age-related endothelial dysfunction in human skeletal muscle feed arteries: the role of free radicals derived from mitochondria in the vasculature

AIM

This study sought to determine the role of free radicals derived from mitochondria in the vasculature in the recognized age-related endothelial dysfunction of human skeletal muscle feed arteries (SMFAs).

METHODS

A total of 44 SMFAs were studied with and without acute exposure to the mitochondria-targeted antioxidant MitoQ and nitric oxide synthase (NOS) blockade. The relative abundance of proteins from the electron transport chain, phosphorylated (p-) to endothelial (e) NOS ratio, manganese superoxide dismutase (MnSOD) and the mitochondria-derived superoxide (O2-) levels were assessed in SMFA. Endothelium-dependent and endothelium-independent SMFA vasodilation was assessed in response to flow-induced shear stress, acetylcholine (ACh) and sodium nitroprusside (SNP).

RESULTS

MitoQ restored endothelium-dependent vasodilation in the old to that of the young when stimulated by both flow (young: 68 ± 5; old: 25 ± 7; old + MitoQ 65 ± 9%) and ACh (young: 97 ± 4; old: 59 ± 10; old + MitoQ: 98 ± 5%), but did not alter the initially uncompromised, endothelium-independent vasodilation (SNP). Compared to the young, MitoQ in the old diminished the initially elevated mitochondria-derived O2- levels and appeared to attenuate the breakdown of MnSOD. Furthermore, MitoQ increased the ratio of p-eNOS to NOS and the restoration of endothelium-dependent vasodilation in the old by MitoQ was ablated by NOS blockade.

CONCLUSION

This study demonstrated that MitoQ reverses age-related vascular dysfunction by what appears to be an NO-dependent mechanism in human SMFAs. These findings suggest that mitochondria-targeted antioxidants may have utility in terms of counteracting the attenuated blood flow and vascular dysfunction associated with advancing age.

Delayed presentation of osteochondroma on the ventral surface of the scapula

Osteochondroma is a cartilage-covered bony excrescence that arises from the surface of a bone. It is the most common benign bone tumor in the scapula and can also present as multiple masses in multiple hereditary exostosis. A solitary scapular lesion might lead to "snapping scapula" syndrome, which is characterized by a sometimes audible but usually palpable grinding sensation experienced with scapular abduction. Snapping scapula is usually painless without specific symptoms; however, discomfort may result from the mechanical effects of a ventral scapular mass projecting onto a normally smooth, gliding scapulothoracic joint. Furthermore, malignant transformation of the cartilaginous cap, by virtue of the increased mass, may precipitate symptoms. The visual deformities and interference with major joint function are the most frequent musculoskeletal complaints related by patients. Indications for operative intervention include painful mechanical dysfunction unresponsive to conservative measures and sarcomatous change. Ventral scapular osteochondromas have been reported to cause scapular asymmetry and should be ruled out as part of a differential diagnosis to a "winged" scapula. A solitary osteochondroma can be excised either by arthroscopic or by open means, with the size of the lesion dictating precise management. Scapular osteochondromas usually are detected early during maturation due to mechanical symptoms or gross deformity. Unfortunately, most require surgical excision. Most surgical excisions have been reported in adolescents and young adults. We report an unusual case of osteochondroma from the ventral surface of the scapula in 56-year-old woman who had experienced delayed onset mechanical symptoms which required surgical excision.

Electrical characteristic analysis using low-frequency noise in low-temperature polysilicon thin film transistors

This study carried out an electrical characteristic analysis using low-frequency noise (LFN) in top gate p-type low-temperature polysilicon thin film transistors (LTPS TFTs) with different active layer thicknesses between 40 nm and 80 nm. The transfer characteristic curves show that the 40-nm device has better electrical characteristics compared with the 80-nm device. The carrier number fluctuation, with and without correlated mobility fluctuation model in both devices, has modeled well the measured noise. On the other hand, the trap density and coulomb scattering in the 40-nm device are smaller compared with the 80-nm device. To confirm the effectiveness of the LFN noise analysis, the trap densities at a grain boundary are extracted using in both devices the similar methods of Proano et al. and Levinson et al. That is, coulomb scattering, caused by the trapped charges at or near the interface, has a greater effect on the device with inferior electrical properties. Based on the LFN and the quantitative analysis of the trap density at a grain boundary, the interface traps between the active layer and the gate insulator can explain the devices' electrical degradation.

Caspase-3 activation as a key factor for HBx-transformed cell death

OBJECTIVES

Nuclear factor-kappa B (NF-kappaB) activation has been associated with the tumorigenic growth of hepatitis B virus X protein (HBx)-transformed cells. This study was aimed to find a key target for treatment of HBx-mediated cancers.

MATERIALS AND METHODS

NF-kappaB activation, endoplasmic reticulum-stress (ER-stress), caspase-3 activation, and cell proliferation were evaluated after Chang/HBx cells permanently expressing HBx viral protein were treated with inhibitors of NF-kappaB, proteasome and DNA topoisomerase.

RESULTS

Inhibition of NF-kappaB transcriptional activity by transient transfection with mutant plasmids encoding Akt1 and glycogen synthase kinase-3beta (GSK-3beta), or by treatment with chemical inhibitors, wortmannin and LY294002, showed little effect on the survival of Chang/HBx cells. Furthermore, IkappaBalpha (S32/36A) mutant plasmid or other NF-kappaB inhibitors, 1-pyrrolidinecarbonidithioic acid and sulphasalazine, were also shown to have little effect on the cell proliferation. By contrast, proteasome inhibitor-1 (Pro1) and MG132 enhanced the HBx-induced ER-stress response and the subsequent activation of caspase-12, -9 and -3 and reduced cell proliferation. Camptothecin (CPT), however, triggered activation of caspase-3 without induction of caspase-12, and reduced cell proliferation. In addition, CPT-induced cell death was reversed by pre-treatment with z-DEVD, a caspase-3-specific inhibitor.

CONCLUSIONS

Detailed exploitation of the regulators of caspase-3 activation could open the gate for finding an efficient target for development of anticancer therapeutics against HBx-transformed hepatocellular carcinoma.

Pharmacokinetics and metabolism of acriflavine in rats following intravenous or intramuscular administration of AG60, a mixture of acriflavine and guanosine, a potential antitumour agent

Acriflavine (ACF; CAS 8063-24-9), a mixture of trypaflavine (TRF) and proflavine (PRF) at a ratio of 2:1 is being investigated in rodents as an anticancer agent. However, its pharmacokinetics have not been investigated in mammals. Guanosine is known to potentiate the anticancer activity of some compounds. The pharmacokinetics of AG60, a 1:1 mixture of ACF and guanosine, were therefore investigated in rats. Rats were given 2 or 10 mg kg(-1) AG60 by intravenous bolus or 6 or 30 mg kg (-1) intramuscularly. An HPLC-based method was developed to analyse the levels of TRF, PRF, and their metabolites in plasma, bile, urine and tissue homogenates. The plasma concentrations of TRF and PRF decreased rapidly after intravenous administration and more slowly after intramuscular administration. Both TRF and PRF were distributed widely, most notably in the kidney, and were eliminated slowly. Three glucuronosyl conjugate metabolite peaks were tentatively identified in the bile. The intramuscular route leads to a prolongation of TRF or PRF plasma levels, and the systemic exposures for both TRF and PRF were both relatively high. These observations indicate that the intramuscular route may be the best way to administer AG60 for various clinical applications.

Human hair growth enhancement in vitro by green tea epigallocatechin-3-gallate (EGCG)

Green tea is a popular worldwide beverage, and its potential beneficial effects such as anti-cancer and anti-oxidant properties are believed to be mediated by epigallocatechin-3-gallate (EGCG), a major constituent of polyphenols. Recently, it was reported that EGCG might be useful in the prevention or treatment of androgenetic alopecia by selectively inhibiting 5alpha-reductase activity. However, no report has been issued to date on the effect of EGCG on human hair growth. This study was undertaken to measure the effect of EGCG on hair growth in vitro and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro. EGCG promoted hair growth in hair follicles ex vivo culture and the proliferation of cultured DPCs. The growth stimulation of DPCs by EGCG in vitro may be mediated through the upregulations of phosphorylated Erk and Akt and by an increase in the ratio of Bcl-2/Bax ratio. Similar results were also obtained in in vivo dermal papillae of human scalps. Thus, we suggest that EGCG stimulates human hair growth through these dual proliferative and anti-apoptotic effects on DPCs.

An algorithm to detect a center of pupil for extraction of point of gaze

This work proposes an algorithm that is developed for the video-oculograph method. It is used to detect a center of pupil for extraction of point of gaze in the eye image acquired by a charge coupled device camera and TV receiver card. The center of pupil could be detected accurately by applying the proposed algorithm in this study that removes noise effectively caused by eyelashes and image that is projected on pupil. In this study, we assume that the pupil is a perfect circle in the captured eye images.

Skin problems after a tsunami

BACKGROUND

On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated.

OBJECTIVE

To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami.

METHODS

Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh Province, Indonesia.

RESULTS

The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. Contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected.

CONCLUSIONS

Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.

Ethnic characteristics of eyelashes: a comparative analysis in Asian and Caucasian females

BACKGROUND

Despite similar biochemical composition of human hair between races, physico-morphological characteristics are not identical in different ethnic groups. Eyelashes have been investigated far less than scalp hair, and the information available is insufficient.

OBJECTIVES

To obtain basic information about eyelashes and to clarify differences between female eyelashes in Asians and Caucasians.

METHODS

Twenty Asian and 10 white Caucasian female volunteers aged between 20 and 29 years were admitted to the study. Lateral digital photographs of upper eyelashes were taken and curl-up and lift-up angles of upper eyelashes were measured from lateral views. Images of upper eyelashes were also taken using the phototrichogram technique and total numbers, lengths and thicknesses of upper eyelashes were obtained (a total of 4661 eyelashes; 2946 for Asian, 1715 for Caucasian). The central portion of the eyelashes or whole eyelashes were clipped and images were taken immediately and 7 days later to obtain the growth rate and anagen ratio of upper eyelashes. Numbers and thickness of eyelash cuticular layers were obtained by electron microscopy.

RESULTS

Compared with Caucasians, Asian eyelashes revealed lower lift-up and curl-up angles, fewer numbers and a thicker transverse diameter. However, no statistical difference was observed in length or growth rate. Duration of anagen was estimated at about 2 months. The eyelash anagen ratio obtained from five Asians was 17.8 +/- 3.3%. By electron microscopy, the number of cuticular layers in transverse section was greater in Asian (8.0 +/- 1.2) than Caucasian females (6.5 +/- 1.1), but no statistical difference was found in single cuticle layer thickness between the two groups. Moreover, eyelash characteristics were not influenced by eye makeup in either race.

CONCLUSIONS

Our results on eyelash morphology and growth characteristics demonstrated significant ethnic differences in Asian and Caucasian females that could provide basic information for future investigations.

Effects of feeding antibiotic-free creep feed supplemented with oligofructose, probiotics or synbiotics to suckling piglets increases the preweaning weight gain and composition of intestinal microbiota

The objective of this study was to determine whether feeding an antibiotic-free creep feed supplemented with either oligofructose, probiotics or synbiotics to suckling piglets influences growth performance, the gut microflora, gut morphology and hematological traits at weaning. Twenty sows with 10 piglets each were randomly assigned to one of four treatments. The treatments consisted of a control (antibiotic-free) diet, 0.2% oligofructose (OF), 0.3% probiotics or 0.5% synbiotics (mixture of 0.2% OF+0.3% probiotics). Piglets were offered the diet ad libitum from 7 d after birth until one day after weaning (21 d of age). At the day after weaning, blood samples were collected from the jugular vein to determine the immune response. Digesta samples of the ileum and colon were collected to determine the microbial composition. Tissue segments from the duodenum and ileum were collected for morphometric measurements of the small intestine. The average daily weight gain was significantly higher for piglets fed the OF or synbiotics diet compared with the pigs fed the control diet. The hematological traits (the concentration of lymphocytes and neutrophils in whole blood) were not affected by the diet. Piglets fed the OF, probiotics or synbiotics diet had a significantly decreased number of total coliform bacteria in the colon. Feeding OF, probiotics or synbiotics significantly increased the population of bifidobacteria in the ileum compared to the control. In the colon, the probiotics and synbiotics diet significantly increased the number of bifidobacteria compared with the control diet. The results of this experiment showed that supplementation of oligofructose or synbiotics to an antibiotic-free creep feed during the preweaning period affected gut microbial population and performance of piglets.

Prognostic significance of glycaemic control in patients with HBV and HCV-related cirrhosis and diabetes mellitus

AIMS

Diabetes mellitus (DM) is frequently observed in patients with cirrhosis, particularly that due to hepatitis C virus (HCV) infection. However, no studies have focused on the clinical significance of glycaemic control in cirrhotic patients because of their short life expectancy and poor hepatic function. The aim of this study was to evaluate the prognostic impact of glycaemic control in patients with hepatitis B virus (HBV) and HCV-related cirrhosis and DM.

METHODS

A total of 434 patients with HCV-related (HCV group, n = 88) or HBV-related (HBV group, n = 346) cirrhosis were studied retrospectively. We determined the prevalence of DM and treatment methods for hyperglycaemia and status of glycaemic control, and the patients' outcome.

RESULTS

The prevalence of DM was 43.2% (38/88) in the HCV group and 19.7% (68/346) in the HBV group. Patients in the HCV group were older with a female preponderance. DM was detected before the diagnosis of cirrhosis or simultaneously in 92% and 79% in the HCV and HBV groups, respectively. Most patients were treated with insulin or oral hypoglycaemic agents. However, blood glucose levels were maintained within the normal range in 34.2% of the HCV group and in 23.5% of the HBV group. Forty-six patients died during the observation period in both groups. Hepatic failure was the most common cause of death, and sepsis and variceal bleeding were more frequent in the HCV group than in the HBV group. Multivariate analysis showed that Child-Pugh class was the most important factor for survival in both groups. In the HCV group, the status of glycaemic control was a significant independent factor of survival (P = 0.018). In the HBV group, age and the development of spontaneous bacterial peritonitis were significant.

CONCLUSION

DM is more frequent in patients with HCV-related cirrhosis than in patients with HBV. Strict control of blood glucose levels could improve survival in HCV patients. A precise assessment of the risks and benefits of glycaemic control is required to reduce the mortality and morbidity of patients with cirrhosis and DM.

Molecular cloning of levan fructotransferase gene from Arthrobacter ureafaciens K2032 and its expression in Escherichia coli for the production of difructose dianhydride IV

AIMS

To clone and overexpress a novel levan fructotransferase gene lftA from Arthrobacter ureafaciens K2032.

METHODS AND RESULTS

The lftA gene, encoding a levan fructotransferase (LFTase) of 521 amino acids (aa) residues, was cloned from the genomic DNA of A. ureafaciens K2032, and overexpressed in Escherichia coli. The recombinant LFTase overexpressed in E. coli was then used to produce a difructose dianhydride (DFA IV) from levan. DFA IV crystals with 97% purity could be obtained from the reaction mixture in 83.7% yield by using a natural crystallization method.

CONCLUSIONS

The lftA gene cloned from A. ureafaciens K2032 encode a novel levan fructotransferase which produces difructose dianhydride (DFA IV) from levan.

SIGNIFICANCE AND IMPACT OF THE STUDY

Levan fructotransferase is a useful enzyme with great promise in the production of DFA IV and various fructosides.

Cloning and expression of a novel esterase gene cpoA from Burkholderia cepacia

AIMS

To screen and clone a novel enzyme with specific activity for the resolution of (R)-beta-acetylmercaptoisobutyrate (RAM) from (R,S)-beta-acetylmercaptoisobutyrate [(R,S)-ester].

METHODS AND RESULTS

A micro-organism that produces a novel esterase was isolated and identified as the bacterium Burkholderia cepacia by using the analysis of cellular fatty acids, Biolog automated microbial identification/characterization system, and 16S rRNA gene sequence analysis. A novel esterase gene was cloned from the chromosomal DNA of B. cepacia and was designated as cpoA. The cpoA encodes a polypeptide of 273 amino acids which shows a strong sequence homology with many bacterial nonhaeme chloroperoxidases. In addition, a typical serine-hydrolase motif, Gly-X-Ser-X-Gly, and the highly conserved catalytic triad, Ser95, Asp224, and His253, were identified in the deduced amino acid sequence of cpoA by multiple sequence alignment.

CONCLUSION

The cpoA cloned from B. cepacia encodes a novel esterase which is highly related to the nonhaeme chloroperoxidases.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that describes the isolation and cloning of a serine esterase gene from B. cepacia, which is useful in the chiral resolution of (R,S)-ester. The cloned gene will allow additional research on the bifunctionality of the enzyme with esterase and chloroperoxidase activity at the structural and functional levels.

A case of primary adenosquamous carcinoma of the liver presented with liver abscess

Primary adenosquamous carcinoma of the liver is a very rare type of cholangiocarcinoma and is defined as a cancer containing both squamous and adenomatous components in the same lesion. Recently, we experienced a primary adenosquamous carcinoma of the liver presented as liver abscess. A 63-year-old man was presented with a 4-day history of fever and chill. The radiologic study showed a 4 cm-sized, central hypoattenuated mass with peripheral rim enhancement in the left lobe of the liver. Ultrasonography-guided aspiration and biopsy suggested an adenocarcinoma with abscess in the liver. At laparotomy, the tumor occupied the left lobe of the liver and invaded the right diaphragm. An extended left lobectomy and a partial excision of the involved diaphragm were done. Grossly, the tumor was 6 x 5 x 5 cm in size and had an eccentric necrosis. Microscopically, the tumor was composed of adenocarcinoma and squamous cell carcinoma with a transitional area.

The temporal alteration of GAD67/GAD65 ratio in the gerbil hippocampal complex following seizure

In the present study, the distribution of glutamic acid decarboxylase (GAD) isoforms in the hippocampus of the Mongolian gerbil and its association with different sequelae of spontaneous seizure were investigated to identify the roles of balance of GAD isoforms in the epileptogenesis and the recovery mechanisms in these animals. The GAD67/GAD65 ratio in the hippocampus of pre-seizure seizure sensitive (SS) gerbil was approximately 3.5-fold higher as compared to seizure resistant (SR) gerbil. Following seizure, this ratio shifted to the level of SR gerbils up to 12 h postical. Therefore, the mismatched GAD67/GAD65 ratio (imbalance of GAD isoform expressions) in the hippocampus of SS gerbil implies that GABAergic neurons may be highly activated in order to regulate the increased neuronal excitability. In addition, the alteration in this ratio after seizure may be the compensatory response for reduction of epileptic activity in this animal.

Effect of diazinon on behavior of Japanese medaka (Oryzias latipes) and gene expression of tyrosine hydroxylase as a biomarker

This paper reports on the development of a biomarker used to monitor abnormal behaviors caused by diazinon in Japanese medaka (Oryzias latipes) as a model organism. Tyrosine hydroxylase (TH) activity in tissues was measured and the TH enzyme production in specific organs using a in situ cytochemical technique was monitored. These data were comparatively analyzed with those from semi-quantitative RT-PCR utilizing medaka TH gene that could be a potential biomarker for neuronal modulations and behaviors. For monitoring experiments at behavioral and molecular biological levels, the fish were treated under different sublethal conditions of diazinon (O, O-diethyl O-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] phosphorothioate) and their behavioral responses were observed. There were no significant differences in activity of TH head and body portions when the fish were exposed to lower concentrations (0.5-10 ppb) of diazinon including control treatment (0 ppb) for 24 hr. In temporal change of TH activity at 100 ppb diazinon treatment, however, the activity of body portion appeared to be inhibited during the first 30 min exposure but later seemed to recover slightly after 1 hr. TH appeared to be expressed mainly in the olfactory bulb, midbrain and brain stem regions as assessed by in situ immunohistochemistry. The treatment (1000 ppb) significantly suppressed TH protein production in the olfactory bulb, midbrain and brain stem regions. In kidney from the body portion the higher concentration treatment (1000 ppb) caused little suppression compared with the control. The RT-PCR showed that a production of TH mRNA transcript was significantly inhibited at 5 ppm diazinon treatment in the body portion. It was concluded that a suppression of TH activity would be one of the causes for the abnormal behaviors of the medaka that could be quantitatively monitored using an image processing system. This study provides molecular and neurobehavioral bases of a biomonitoring system for toxic chemicals using a model organism such as fish.

Changes of skin blood flow and color on lesional and control sites during PUVA therapy for psoriasis

BACKGROUND

Although the colors of psoriatic lesions, largely determined by erythema and scales, are important clinical indicators, expressing them in an objective manner is difficult. Cutaneous blood flow (CBF) also affects erythema. Serial measurement of these parameters during phototherapy was almost nonexistent.

OBJECTIVE

The objectives of our study were to observe the changes of color parameters and the CBF of psoriatic lesions during PUVA therapy and to determine their clinical significance.

METHODS

CBF, measured by laser Doppler flowmetry, and color parameters, measured by tristimulus colorimetry and reflectance spectrophotometry, were assessed in 13 patients with psoriasis who received PUVA therapy.

RESULTS

The values of CBF, erythema index (EI), and a(*) (color parameter representing red-green axis) in psoriatic lesions were significantly different from those observed in the control sites before therapy. The parameters of psoriatic lesions normalized according to the clinical improvement and approached those of the control sites as PUVA therapy progressed. The values of melanin index (MI), L(*) (color parameter representing white-black axis), and b(*) (color parameter representing yellow-blue axis) showed no significant difference between the psoriatic plaques and the control sites. They all displayed changes toward darkening and indicated tanning induced by PUVA therapy. Serial changes presented a generally unidirectional pattern in the control sites. However, this was not always the case in psoriatic lesions because scale, infiltration, and erythema also affected the measurement of blood flow and the color of the skin.

CONCLUSION

Color parameters and CBF were closely related with clinical improvement according to consecutive phototherapy. They may serve as objective indices for the visible morphology and underlying lesional pathophysiology of psoriasis.

Microbial PCB dechlorination in dredged sediments and the effect of moisture

Evidence of reductive dechlorination of polychlorinated biphenyls (PCBs) in sediments was investigated in Hudson River sediments dredged and encapsulated in 1978 at Moreau, NY. The effect of different moisture contents in dredged sediments on dechlorination and dechlorinating microorganisms was also determined using PCB-spiked sediments in which the moisture level was adjusted by simulating a dewatering process. The congener pattern of PCBs indicated that the dechlorination in the dredged sediments was far less advanced than that in the river sediments collected from the general area of the dredged site (Ft. Edward site). Dechlorination in encapsulated sediments at the Moreau site appeared to have stopped soon after dredging. When microorganisms eluted from the encapsulated sediments were inoculated in clean sediments spiked with Aroclor 1242, an extensive dechlorination was observed, indicating that the encapsulated sediments still harbored dechlorinating microorganisms. However, the same inoculum failed to further dechlorinate residual congeners in the dredged sediments. On the other hand, an inoculum obtained in 1990 from the dredged site in the Hudson River dechlorinated the residual congeners further. In simulated dredged sediments, the maximum level of dechlorination was lower at reduced moisture contents. The population size of dechlorinating microorganisms, as determined by the most probable number (MPN) technique, was also smaller at the lower moisture levels. There was a significant correlation between the maximum extent of dechlorination and the specific death rate of dechlorinating populations. These results indicate that the underlying mechanism of the moisture-dependent maximum dechlorination is the moisture-dependence of the death rate of dechlorinating microorganisms.

Molecular epidemiology of hepatitis A virus in Korea

BACKGROUND

The prevalence of antibodies for hepatitis A virus (anti-HAV) in adolescents and young adults has decreased remarkably following the economic growth in Korea. As a result, this age group has a high risk for HAV infection paradoxically, and over 1500 cases of clinically overt hepatitis A occurred in 1998. Human isolates of hepatitis A virus (HAV) are categorized within four genotypes (I, II, III, and VII). In some geographic regions, closely related isolates cluster, suggesting endemic spread of the virus, while in other regions multiple genotypes circulate. Virtually no data are available with regard to the genetic relatedness of Korean strains of HAV.

METHODS AND RESULTS

A 168 base pair segment encompassing the putative VP1/2A junction of the HAV genome was amplified by RT-PCR and sequenced in sera of 18 Korean patients with a sporadic form of acute hepatitis A. Pairwise comparisons of the nucleic acid and amino acid sequences of 18 Korean isolates with one another revealed that the Korean isolates showed > 94.6% and > 96.4% identity, respectively. All of the 18 Korean isolates clustered within genotype IA, irrespective of the geographic locations and the time that hepatitis occurred. Unique amino acid sequence changes that had never been reported in genotype IA were found in nine of the 18 isolates. These changes were Gln-->Ser and Lys-->Arg in 2A-19 and 2A-10 amino acid positions.

CONCLUSION

The presence of single genotype and unique mutations may be related with the circulation of endemic HAV over a long period of time in Korea.

Specific inhibition of transforming growth factor-beta2 expression in human osteoblast cells by antisense phosphorothioate oligonucleotides

To elucidate the role of endogenous transforming growth factor (TGF)-beta2 on human osteoblast cell, antisense phosphorothioate oligonucleotides (S-ODNs) complementary to regions in mRNA of TGF-beta2 were synthesized and examined their effects on TGF-beta2 production and cell proliferation in a human osteoblast cell line ROS 17/2. Antisense S-ODNs were designated for three different target regions in the mRNA of TGF-beta2. Among several antisense S-ODN analyzed, an oligonucleotide (AS-11) complementary to the translation initiation site of mRNA of TGF-beta2 demonstrated a selective and strong inhibitory effect on TGF-beta2 production in osteoblast cells. Other antisense S-ODNs which were designated for other regions in mRNA of TGF-beta2 and one- or three-base mismatched analogs of AS-11 showed little or much less antisense activities than AS-11. Therefore, the most effective target site in mRNA of TGF-beta2 is at the initiation codon region. The antisense effects of AS-11 were observed without reduction of levels of mRNA of TGF-beta2. Furthermore, the inhibition of TGF-beta2 expression by antisense S-ODN appeared to enhance cell proliferation, demonstrating the growth inhibitory effect of autocrine TGF-beta2 in osteoblast cells.

Prenatal fumonisin (FB1) treatment in rats results in minimal maternal or offspring toxicity

To investigate the neurobehavioral and developmental effects of the mycotoxin, FB1, Sprague-Dawley rats were treated with FB1 on gestational days 13-20. In Experiment 1, FB1 was obtained from culture material and pregnant rats were gavaged with 0, 0.8 or 1.6 mg/kg. In Experiment 2, pregnant rats were gavaged with purified FB1 at doses of 0, 1.6 or 9.6 mg/kg. Offspring were evaluated on a battery of behavioral tests as well as measures of whole and regional brain weight. There were no effects on maternal weight gain, reproductive outcomes, or offspring body weight through adulthood in either experiment. Complex maze performance, open field and running wheel activity were not altered by prenatal FB1 treatment. In Experiment 2, acoustic startle response was depressed at two ages during the first or second block of 9 trials in males treated with purified FB1. Females exhibited no such alterations. Play behavior at PND 33, but not PND 26, was increased in males prenatally treated with 9.6 mg/kg relative to those treated with 1.6 mg/kg. There were no substantive treatment effects on regional brain weight. These results suggest that doses of < or = 9.6 mg purified FB1/kg and/or < or = 1.6 mg FB1/kg obtained from culture material cause minimal maternal toxicity and produce few development functional alterations. In addition, potential FB1-related functional alterations were evident only in males providing further support for a mild sex-specific effect for fumonisin.

Fumonisin B1 in developing rats alters brain sphinganine levels and myelination

Objectives of this study were to test the hypothesis that fumonisin B1 (FB1) alters sphinganine (Sa) levels and myelin synthesis in the central nervous system of developing rats. FB1 (subcutaneous, 0.4 or 0.8 mg/kg/day) from postnatal days (PND) 3 to PND 12 resulted in a significant reduction of body weight gain and decreased survival rates. Both Sa levels and Sa/sphingosine (So) ratios were significantly increased in the brain of rats given 0.8 mg FB1/kg/day. To confirm the effect of limited nutrition on changes in the Sa levels and myelinogenesis, rats given 0.8 mg FB1/kg/day or treated by limited nutrition (temporary removal from dam during postnatal period) were compared to those in saline controls. Sa levels and Sa/So ratios were increased significantly in the 0.8 FB1-treated, but were not altered in the limited nutrition group. Myelin deposition in the corpus callosum and 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activities were decreased significantly in both nutritionally limited and FB1-exposed rats. These data indicate that sphingolipid metabolism in the central nervous system of developing rats is vulnerable to FB1 exposure. The hypomyelination associated with FB1-treatment may be mediated by limited nutrition.

Cyclo(dehydroala-L-Leu), an alpha-glucosidase inhibitor from Penicillium sp. F70614

A diketopiperazine (1) has been isolated from the culture broth of Penicillium sp. F70614 and its structure has been determined to be cyclo(dehydroala-L-Leu) by various spectroscopic analyses. This compound selectively inhibited yeast alpha-glucosidase and porcine intestinal alpha-glucosidase with IC50 values of 35 and 50 microg/ml, respectively. However, it did not show significant inhibitory effects against almond beta3-glucosidase, Aspergillus alpha-galactosidase, Escherichia coli beta-galactosidase and jack bean alpha-mannosidase.

Human brain GABA transaminase tissue distribution and molecular expression

Human brain gamma-aminobutyrate transaminase is differentially expressed in a tissue-specific manner. mRNA master dot-blot analysis for 50 different human tissues, including different brain regions and fetal tissues, provided a complete map of the tissue distribution. Genomic Southern analysis revealed that the gamma-aminobutyrate transaminase gene is a single copy, at least 15 kb in size. In addition, human brain gamma-aminobutyrate transaminase cDNA was expressed in Escherichia coli using a pGEX expression vector system. Catalytically active gamma-aminobutyrate transaminase was expressed in large quantities and the purified recombinant enzyme had kinetic parameters that were indistinguishable from those isolated from other mammalian brains. The human enzyme was inactivated by a well-known antiepileptic drug vigabatrin. Values of Ki and kinact were 1 mM and 0.35 min-1, respectively. Results from inactivation kinetics suggested that human gamma-aminobutyrate transaminase is more sensitive to the vigabatrin drug than the enzyme isolated from bovine brain.

Detection of hepatitis A viral RNA in sera of patients with acute hepatitis A

BACKGROUND AND AIMS

The Detection of hepatitis A virus (HAV) is important for diagnosis and epidemiological studies of hepatitis A. The polymerase chain reaction (PCR) technique is a sensitive test to detect HAV-RNA in specimens. The aims of the present study were to clarify the detection rate of serum HAV-RNA by PCR and the natural history of HAV viraemia, and to determine the correlation between viraemia and the clinical characteristics in patients with acute hepatitis A.

METHODS

Hepatitis A virus RNA was tested in 74 serum samples which were serially collected from 27 patients with acute hepatitis A. A nested reverse transcription (RT)-PCR for HAV-RNA was performed with primer sets located at the VP1 region of the HAV genome and the PCR products were electrophoresed on a 1.5% agarose gel.

RESULTS

Hepatitis A virus RNA was found in 18 of 27 (67%) patients with hepatitis A. There were no significant differences between groups positive and negative for HAV-RNA in clinical and laboratory data, except the time interval between clinical onset and initial serum sampling for RT-PCR (10 +/- 6 vs 19 +/- 14 days) and the alanine aminotransferase (ALT) level at initial serum sampling for RT-PCR (1436 +/- 1416 vs 518 +/- 432 IU/L). The mean duration of HAV viraemia was 30 +/- 19 days (range, 5-59 days). The duration of HAV viraemia and duration of abnormal ALT levels from clinical onset were positively correlated (r = 0.685, P = 0.007).

CONCLUSION

In conclusion, HAV-RNA RT-PCR is a useful tool to detect HAV viraemia and to study the molecular epidemiology of HAV infection.

Human pyridoxal kinase: overexpression and properties of the recombinant enzyme

Pyridoxal kinase catalyses the phosphorylation of the vitamin B6. A human brain pyridoxal kinase cDNA was isolated, and the recombinant enzyme was overexpressed in E. coli as a fusion protein with maltose binding protein (MBP). Pure pyridoxal kinase exhibits a molecular mass of about 40 kDa when examined by SDS-PAGE and FPLC gel filtration. The recombinant enzyme is a monomer endowed with catalytic activity, indicating that the native quaternary structure of pyridoxal kinase is not a prerequisite for catalytic function. Zn2+ is the most effective divalent cation in the phosphorylation of pyridoxal, and the human enzyme has maximum catalytic activity in the narrow pH range of 5.5-6.0. The Km values for two substrates pyridoxal and ATP are 97 microM and 12 microM, respectively. In addition, the unfolding processes of the recombinant enzyme were monitored by circular dichroism. The values of the free energy change of unfolding (AGo = 1.2 kcal x mol(-1) x K(-1)) and the midpoint transition (1 M) suggested that the enzyme is more stable than ovine pyridoxal kinase against denaturation by guanidine hydrochloride. Intrinsic fluorescence spectra of the human enzyme from red-edge excitation and fluorescence quenching experiments showed that the tryptophanyl residues are not completely exposed and more accessible to neutral acrylamide than to the negatively charged iodide. The first complete set of catalytic and structural properties of human pyridoxal kinase provide valuable information for further biochemical studies on this enzyme.

Identification of propentofylline metabolites in rats by gas chromatography/mass spectrometry

Propentofylline (PPF, 3-methyl-1-(5-oxohexyl)-7-propylxanthine) has been reported to be a compound for treatment of both vascular dementia and dementia of the Alzheimer type. The short half-life (about 15 min) of PPF at the terminal elimination phase and poor bioavailability after oral administration of PPF to rabbits (Kim et al., 1992) suggest in part that this drug takes the extensive first-pass metabolism in the liver. In addition, the metabolic pathway for PPF remains unclear. The objective of this experiment is to identify urinary metabolites of PPF in rats. For the identification of the metabolites, rat urine was collected after oral administration of 100 mg/kg PPF. PPF metabolite, 3-methyl-1-(5-hydroxyhexyl)-7-propylxanthine, was synthesized and confirmed by gas chromatography/mass spectroscopy (GC/MS) and 1H nuclear magnetic resonance spectroscopy. The urinary metabolites of PPF were extracted with diethyl ether and identified by electron impact and chemical ionization GC/MS. One urinary metabolite was confirmed to be 3-methyl-1-(5-hydroxyhexyl)-7-propylxanthine by synthesized authentic compound. Several metabolites of monohydroxy- and dihydroxy-PPF were identified based on mass fragmentation of both intact and trimethylsilylated derivatives of PPF metabolites and the novel structure of these metabolites is suggested based on mass spectra.

Biochemical and morphological effects of fumonisin B(1) on primary cultures of rat cerebrum

Chronic dietary consumption of the mycotoxin fumonisin B(1) (FB(1)) is associated with leukoencephalomalacia and neuronal degeneration, but identification of the cellular mechanisms underlying this neurotoxicity is difficult due to concurrent adverse systemic changes. For this reason, the present investigation used an in vitro approach to assess the short-term consequences of direct FB(1) (0. 5-75 microM) exposure on astrocytes and oligodendrocytes in primary cultures of rat cerebrum. Beginning at 5 days in vitro, the cultures were exposed to FB(1) at five concentrations (0.5-75 microM), and the cultures were evaluated at 10 and 15 days in vitro. The levels of the sphingolipid-associated constituents sphingosine and sphinganine were determined with a high-performance liquid chromatography. Relative to untreated cultures, exposure to FB(1) diminished the levels of sphingosine at 15 days in vitro, whereas FB(1)-exposed cultures showed significantly increased sphinganine levels and sphinganine/sphingosine ratios. In addition to these changes in sphingolipid constituents, FB(1)-exposed (0.5-75 microM) cultures exhibited a two-fold increase in the number of process-bearing cells by 15 days in vitro. Also, the activity of 2', 3'-cyclic nucleotide 3'-phosphohydrolase, an enzyme associated with myelin and oligodendrocytes, was increased in FB(1)-treated cultures. This study suggests that short-term exposure to FB(1) may modify the proliferation or differentiation of glial cells.

Refolding of pyridoxine-5'-P oxidase assisted by GroEL

The unfolding of brain pyridoxine-5'-P oxidase by guanidinium chloride has been investigated at equilibrium. Circular dichroism, fluorescence spectroscopy and gel exclusion chromatography were used to monitor the unfolding process. The enzyme dissociates reversibly into monomers, but the fluorescence properties of the cofactor FMN are not restored upon dilution with potassium phosphate buffer (pH 7.4). Spontaneous refolding leads to 20% recovery of the catalytic activity. Addition of GroEL to the renaturing buffer accelerates the recovery of catalytic activity that approaches a level of 80% with respect to the native enzyme. The rate of recovery of catalytic activity assisted by GroEL parallels the rate of FMN fluorescence quenching, suggesting that structural rearrangements of the catalytic domain is the last step to take place in the refolding process.