Effects of tannic acid and its related compounds on food mutagens or hydrogen peroxide-induced DNA strands breaks in human lymphocytes

The effect of tannic acid (TA), gallic acid (GA), propyl gallate (PA) and ellagic acid (EA) on DNA damage in human lymphocytes induced by food mutagens [3-amino-1-methyl-5H-pyrido (4,3-b) indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimadazo (4,5-b) pyridine (PhIP) or H2O2 was evaluated by using single-cell electrophoresis (comet assay). The toxicity of these tested compounds (0.1-100 microg/ml) on lymphocytes was not found. These compounds did not cause DNA strand breaks at lower concentrations of 0.1-10 microg/ml. At a concentration of 100 microg/ml, TA and GA exhibited slight DNA damage, whereas PA and EA showed no DNA strand breaks. TA and its related compounds decreased the DNA strand breaks induced by Trp-P-2, PhIP or H2O2 at concentrations of 0.1-10 microg/ml. DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycoslase (FPG)] were used to examine the levels of oxidised pyrimidines and purines in human lymphocytes induced by H2O2. All the compounds at 10 microg/ml can reduce the level of FPG sensitive sites. However, only EA inhibited the formation of EndoIII sensitive sites. The results indicated that these compounds can enhance lymphocytes resistance towards DNA strand breaks induced by food mutagens or H2O2 in vitro.

Do patients with acute liver failure have a better chance to receive liver grafting?

OBJECTIVE

Patients with acute hepatic failure (AHF) were always given first priority on the transplant waiting list. We investigated whether AHF patients will deprive other patients on the waiting list of the chance of liver transplantation (LTx).

METHODS AND RESULTS

From January 1999 to March 2003, a total of 423 patients were on the transplant waiting list at the National Taiwan University Hospital. Sixty-five of the patients had AHF caused by hepatitis-B-related disease (HBV, n = 52, 80%), Wilson disease (n = 3, 4.6%), drug-induced AHF (n = 3, 4.6%), and other causes (n = 7, 10.8%).Thirty-three patients died and 16 survived by medical treatment. Two received LTx abroad and 14 underwent LTx at our hospital (7 living-related; 7 cadaver). A total of 140 patients died while waiting for a transplant during the period studied. Of them, 107 were among 358 non-AHF patients (30%), and time-to-death interval was 133 +/- 175 days (median: 62); 33 were among 65 AHF patients (51%); time to death was 19 +/- 28 days (median: 8). There were 35 cadaver donor livers available during the period; 28 of 358 non-AHF patients (7.8%), and 7 of 65 AHF patients (10.7%) received cadaveric LTx. Their waiting time totaled 342 +/- 316 and 12 +/- 9 days, respectively (P < .0001).

CONCLUSION

Most AHF patients died unless they received liver grafts. Even with a higher priority assigned to them, AHF patients still have little chance to get a cadaver donor liver in Taiwan, and non-AHF patients have an even slimmer chance. Therefore, we need to encourage liver donation from living-related donors.

Micro and nano-fabrication of biodegradable polymers for drug delivery

This paper presents state-of-the-art micro and nano-fabrication techniques for biodegradable polymers. Replication molding, using a rigid or elastic master, can pattern structures on a polymer surface in a submicron resolution at a low cost. Layer-by-layer rapid prototyping methods are promising in producing controlled release units with complicated geometries, release mechanisms and the ability to control microstructure and composition. Special attention is paid to the fast, flexible, and non-invasive laser fabrication techniques that have great potential in the fabrication of biodegradable polymer drug delivery devices in both a laboratory and industry scale.

Diallyl disulfide (DADS) induced apoptosis undergo caspase-3 activity in human bladder cancer T24 cells

Diallyl disulfide (DADS), one of the major components of garlic (Allium sativum), is well known to have chemopreventative activity against human cancer such as colon, lung and skin. But the exact mechanism of the action is still unclear. In this study, we investigated how DADS--induced cell cycle arrest and apoptosis in T24 human bladder cancer cells in vitro. Apoptosis induction, cell viability, cell cycle arrest, caspases-3, -9 activity and gene expression were measured to determine their variation by flow cytometric assay, western blot, and determination of caspase-3 activity, PCR and cDNA microarray. There are significant differences in cell death (decreased viable cells then increased the amounts of apoptosis) of T24 cells that were detected between DADS (5-75 microM) treated and untreated groups. A significant increase was found in apoptosis induction when cells were treated with DADS (50 microM) compared to without DADS treated groups. DADS also promoted caspase-3 activity after exposure for 1, 3, 6, 12, and 24 h, which led to induce apoptosis. DADS also increased the product of intracellular hydrogen peroxide. Furthermore, the DADS-induced apoptosis on T24 cells was blocked by the broad-spectrum caspase inhibitor, z-VAD-fmk and antioxidant (catalase). DADS also increased cyclin E and decreased CDK2 gene expression which may lead to the G2/M arrest of T24 cells.

The fluid property dependency on micro-fluidic characteristics in the deposition process for microfabrication

The droplet impingement into a cavity at micrometer-scale is one of important fluidic issues for microfabrications, e.g. the inkjet deposition process in the PLED display manufacturing. The related micro-fluidic behaviors in the deposition process should be carefully treated to ensure the desired quality of microfabrication. The droplets generally dispensing from an inkjet head, which contains an array of nozzles, have a volume in several picoliters, while each nozzle responds very quickly and jets the droplets into cavities on substrates with micrometer size. The nature of droplet impingement depends on the fluid properties, the initial state of droplet, the impact parameters and the surface characteristics. The commonly chosen non-dimensional numbers to describe this process are the Weber number, the Reynolds number, the Ohnesorge number, and the Bond number. This paper discusses the influences of fluid properties of a Newtonian fluid, such as surface tension and fluid viscosity, on micro-fluidic characteristics for a certain jetting speed in the deposition process via a numerical approach, which indicates the impingement process consists of four different phases. In the first phase, the droplet stretching outwards rapidly, where inertia force is dominated. In the second phase, the recoiling of droplet is observed, where surface tension becomes the most important force. In the third phase, the gravitational force pulls the droplet surface towards cavity walls. The fourth phase begins when the droplet surface touches cavity walls and ends when the droplet obtains a stable shape. If the fluid viscosity is relatively small, the droplet surface touches cavity walls in the second phase. A stable fluid layer would not form if the viscosity is relatively small.

Guidelines for the use of antifungal agents in the treatment of invasiveCandidaand mould infections

ABSTRACT Treatment of invasive fungal infections is increasingly complex. Amphotericin B deoxycholate has long been the mainstay of treatment. However, there has been increasing recognition of both the propensity for nephro-toxicity in haematology, transplant and intensive care patients as well as its adverse impact on morbidity and mortality. This has coincided with the availabilty of newer, and in certain settings, more effective antifungal agents. Although the newer agents clearly cause less nephrotoxicity than amphotericin B, drug interactions, hepatic effects and unique side-effects need to be considered. The spectrum of the newer triazoles and echinocandins varies, highlighting the importance of accurate identification of the causative organism where possible. Consensus Australian guidelines have been developed to assist clinicians with treatment choices by reviewing the current evidence for the efficacy, the toxicity and the cost of these agents.

Serum insulin-like growth factor-II and alpha-fetoprotein as tumor markers of hepatocellular carcinoma

To evaluate the diagnostic application of serum insulin-like growth factor-II (IGF-II) and alpha-fetoprotein (AFP) levels in hepatocellular carcinoma (HCC), IGF-II and AFP were determined in 100 cirrhotic patients with HCC, 100 sex- and age-matched patients with cirrhosis alone and 50 healthy controls. The results indicated that IGF-II and AFP levels in patients with HCC were higher than in those with cirrhosis alone (p = 0.0001). There is an inverse correlation between IGF-II and (log)AFP (r = -0.410, p = 0.0001) in patients with HCC. Multivariate analysis indicated that IGF-II and AFP were closely associated, in a dose-related fashion, with the presence of HCC. Receiver operating characteristic curves were used to determine the optimal cutoff values of IGF-II (4.5 mg/g prealbumin) and AFP (100 ng/ml), respectively. Both IGF-II and AFP show a high specificity and positive likelihood ratio. The sensitivity was 42.0% for IGF-II and 73.0% for AFP. Determination of both markers in parallel significantly increased the diagnostic accuracy (96.5%) and sensitivity (97.9%), with a high specificity (95.1%) and positive likelihood ratio (19.9). In conclusion, IGF-II and AFP may be used as complementary tumor markers to discriminate HCC from cirrhosis.

Evaluation of natural and enhanced PCP biodegradation at a former pesticide manufacturing plant

Pentachlorophenol (PCP) has been used in the past as a pesticide, herbicide, antifungal agent, bactericide, and wood preservative. Thus, PCP is among the most ubiquitous chlorinated compounds found in groundwater contamination. A former pesticide manufacturing plant located in southern Taiwan has been identified as a PCP spill site. In this study, groundwater samples collected from the PCP site were analyzed to assess the occurrence of natural PCP biodegradation. Microcosm experiments were conducted to (1) evaluate the feasibility of biodegrading PCP by indigenous microbial consortia under aerobic and cometabolic conditions, and (2) determine the potential of enhancing PCP biodegradation using cane molasses and biological sludge cake as the substitute primary substrates under cometabolic conditions. The inocula used in this microcosm study were aquifer sediments collected from the PCP site and activated sludges collected from the municipal and industrial wastewater treatment plants. Results from this field investigation indicate that the natural biodegradation of PCP is occurring and causing the decrease in PCP concentration. Microcosm results show that the indigenous microorganisms can biodegrade PCP under both aerobic and aerobic cometabolism conditions. A PCP-degrading bacterium was isolated from the collected aquifer sediments and identified as Pseudomonas mendocina NSYSU via some biochemical tests and further conformation of DNA sequencing. In batch cultures, P. mendocina NSYSU used PCP as its sole source of carbon and energy. The isolated bacterium, P. mendocina NSYSU, was capable of completely degrading PCP as indicated by the increase in biomass formation with the decrease in PCP concentrations occurred in the carbon-free medium simultaneously. Results indicate that the in situ or on-site aerobic bioremediation using indigenous microorganisms or inoculated bacteria would be a feasible technology to clean up the studied PCP-contaminated site. Results from this study will be useful in designing a scale-up in situ or on-site PCP bioremediation system (e.g., on-site bioreactor) for field application.

Review article: registered nurse-administered propofol sedation for endoscopy

Propofol has several attractive properties that render it a potential alternative sedative agent for endoscopy. Compared with meperidine and midazolam, it has an ultra-short onset of action, short plasma half-life, short time to achieve sedation, faster time to recovery and discharge, and results in higher patient satisfaction. Shorter times to achieve sedation enhance efficiency in the endoscopy unit. Multiple studies have documented the safe administration of propofol by non-anaesthesiologists. Administration by registered nurses is more cost-effective than administration by anaesthesiologists. However, the administration of propofol by a registered nurse supervised only by the endoscopist is controversial because the drug has the potential to produce sudden and severe respiratory depression. More information is needed on how training nurses and endoscopists should proceed to give propofol, as well as the optimal level of monitoring to ensure the safety of nurse-administered propofol.

Detection of Burkholderia pseudomallei in rice fields with PCR-based technique

Burkholderia pseudomallei Ara- in rice fields was detected using PCR-based techniques with 16S RNA and flagella gene primer sets. The sensitivity of these PCRs was at least 1 CFU/mL of B. pseudomallei Ara- preincubated into Ashdown's medium for 6 h. B. pseudomallei Ara- DNA from watery soil were more detectable than from dry soil. The distribution of this DNA was mainly found at a depth of 300-600 mm under crop-covered fields, but not detected in the location of soil close to the land surface. The results suggest that PCR based on 16S RNA and flagella gene primer sets can be applied to investigate the presence of B. pseudomallei Ara- in contaminated soil of rice fields.

Enhanced PCE dechlorination by biobarrier systems under different redox conditions

The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to evaluate the (1) feasibility of enhancing PCE biodegradation using cane molasses and sludge cakes as the primary substrates under methanogenic and iron reducing conditions, and (2) potential of installation a sludge cake/cane molasses biobarrier to clean up PCE-contaminated aquifers. The biodegradability of sludge cake (from secondary wastewater treatment system) and cane molasses was tested using bioavailability experiments. Results show that biodegradable materials were released from sludge cake/cane molasses and utilized by microbial consortia. Based on the chemical oxygen demand (COD) tests, approximately 28 and 248 mg of biodegradable COD can be released from 1g of sludge cake and 1g of cane molasses under anaerobic conditions, which have the potential to convert 70 and 620 mg of PCE to ethylene (ETH), respectively. Reductive dechlorination was evaluated using microcosms containing primary substrates (sludge cake/cane molasses) and inocula (aquifer sediments). Results indicate that sludge cake and cane molasses can serve as the diffusion sources of primary substrates, and enhance the reductive dechlorination of PCE under methanogenic processes. However, results from this study were not sufficient enough to show that reductive dechlorination of PCE would occur under iron-reducing conditions. This indicates that more studies need to be performed to further evaluate the role of iron reduction on the PCE dechlorination. Results reveal that it is feasible and applicable to install a sludge cake or cane molasses biobarrier to clean up PCE contaminated aquifers. From an engineering point of view, the sludge cake/cane molasses biobarrier has the potential to become an environmentally and economically acceptable technology for PCE bioremediation.

Distribution and dynamics of gap junction channels revealed in living cells

To study the structural composition and dynamics of gap junctions in living cells, we tagged their subunit proteins, termed connexins, with the autofluorescent tracer green fluorescent protein (GFP) and its cyan (CFP) and yellow (YFP) color variants. Tagged connexins assembled normally and channels were functional. High-resolution fluorescence images of gap junction plaques assembled from CFP and YFP tagged connexins revealed that the mode of channel distribution is strictly dependent on the connexin isoforms. Co-distribution as well as segregation into well-separated domains was observed. Based on accompanying studies we propose that channel distribution is regulated by intrinsic, connexin isoform specific signals. High-resolution time-lapse images revealed that gap junctions, contrary to previous expectations, are dynamic assemblies of channels. Channels within clusters and clusters themselves are mobile and constantly undergo structural rearrangements. Movements are complex and allow channels to move, comparable to other plasma membrane proteins not anchored to cytoskeletal elements. Comprehensive analysis, however, demonstrated that gap junction channel movements are not driven by diffusion described to propel plasma membrane protein movement. Instead, recent studies suggest that movements of gap junction channels are indirect and predominantly propelled by plasma membrane lipid flow that results from metabolic endo- and exocytosis.

Biotransformation of cyanide to methane and ammonia by Klebsiella oxytoca

Klebsiella oxytoca, isolated from cyanide-containing industrial wastewater, was shown to be able to biodegrade cyanide to non-toxic endproducts using cyanide as the sole nitrogen source. In this study, ammonia was one of the detected endproduct of cyanide biodegradation by the concentrated resting cells of K. oxytoca. Moreover, cyanide has been shown to be biotransformed to methane through the actions of concentrated resting cells. Biodegradation of cyanide by cell-free extracts was not observed, which might be due to the inactivation of nitrogenase (an oxygen-labial enzyme) caused by the oxygen exposure after cell disruption. Results show that the cyanide consumption by resting cells of K. oxytoca was induced when the pretreatment of these cells with cyanide was conducted. However, the cyanide-degrading capability of resting cells pretreated with ammonia was inhibited. The inhibition of cyanide degradation by resting cells of K. oxytoca was affected by the ammonia concentration. This might result from the suppression of nitrogenase activity of K. oxytoca by ammonia since nitrogenase was suggested to be the sole cyanide-degrading enzyme during the cyanide degradation process. Results from this study also show that the processes of cyanide biodegradation and ammonia production by resting cells occurred simultaneously. This suggests that the utilization of cyanide as nitrogen source by K. oxytoca might proceed using ammonia as an assimilatory substrate.

Influence of age on intrarenal resistive index measurement in normal subjects

BACKGROUND

We investigated the influence of age on intrarenal arterial resistive index (RI) measurement in 135 normal subjects (71 male, 64 female; age range = 17-68 years, median age = 37 years).

METHODS

Each subject underwent color Doppler measurement of the intrarenal RI from three distinct interlobar arteries in the superior, middle, and inferior parts of both kidneys. The mean of six RI values obtained from both kidneys was used for analysis. The correlation of RI with different variables was investigated by linear regression and stepwise multiple linear regression. Variables analyzed were age, systolic blood pressure, diastolic blood pressure, mean blood pressure, pulse pressure, and pulse rate.

RESULTS

The results of linear regression showed that age had a significantly positive correlation ( r = 0.276, p = 0.0012) and diastolic blood pressure had a significantly negative correlation ( r = -0.186, p = 0.0311) with the RI. The results of stepwise multiple linear regression showed that the combination of age and diastolic blood pressure could explain approximately 15% of the RI changes ( r(2) = 0.1535).

CONCLUSION

Although there is a statistically significant positive correlation between intrarenal RI and age, the correlation is weak. This suggests that the influence of age on RI measurement is small and may be of no clinical importance.

Establishment of cell lines from a tropical grouper, Epinephelus awoara (Temminck & Schlegel), and their susceptibility to grouper irido- and nodaviruses

Four tropical marine fish cell lines have been established from the eye, fin, heart and swim bladder of grouper, Epinephelus awoara (Temminck & Schlegel). Optimum media and temperature conditions for maximum growth were standardized. The eye and swim bladder cells were mostly epithelial, but the fin and heart cells were mostly fibroblastic. The viability of cells was 95% after 1 year of storage in liquid nitrogen (-196 degrees C). Besides these four cell lines, previously established grouper brain, kidney and liver cell lines were also used for a viral susceptibility study which showed that all the cell lines were sensitive to grouper iridovirus, whereas only brain, fin and liver cell lines were susceptible to the yellow grouper nervous necrosis virus (a nodavirus). Electron microscopy studies of the grouper irido- and nodaviruses in ultrathin sections of infected cells showed an abundance of viral particles in the cytoplasm of the virus-infected cells indicating the effective replication of these two viruses. It is suggested that these cell lines can be used for the isolation of putative fish specific viruses and provide a valuable tool to study the mechanisms of host-pathogen interactions. Furthermore, these cell lines upon transfection, using pEGFP-C1 and pEGFP-aMT2.5 (ayu metallothionein promoter), produced significant fluorescent signals indicating their utility for exogenous studies.

Effects of soil pH, temperature and water content on the growth of Burkholderia pseudomallei

Optimum conditions were determined for the growth of Burkholderia pseudomallei in natural soils or waters. It grows better in paddy soil, crop-covered and fallow field than in fresh and salty water. Although the optimal temperature and pH for the growth were 37 or 42 degrees C, and 6.5 or 7.5 in an environmental-mimicking soil medium, this bacterium can still grow at 4 degrees C, which was suggested to be related with the occurrence of melioidosis in some cold areas. In soil media with water content < 15. B. pseudomallei did not grow until 60 d of incubation, suggesting that water contents of soils in which it dwelled would be one important factor in determining the growth rate.

Remediation of PCE-contaminated aquifer by an in situ two-layer biobarrier: laboratory batch and column studies

The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop an in situ two-layer biobarrier system consisting of an organic-releasing material layer followed by an oxygen-releasing material layer. The organic-releasing material, which contained sludge cakes from a domestic wastewater treatment plant, is able to release biodegradable organics continuously. The oxygen-releasing material, which contained calcium peroxide, is able to release oxygen continuously upon contact with water. The first organic-releasing material layer was to supply organics (primary substrates) to reductively dechlorinate PCE in situ. The second oxygen-releasing material layer was to release oxygen to aerobic biodegrade or cometabolize PCE degradation byproducts from the first anaerobic layer. Batch experiments were conducted to design and identify the components of the organic and oxygen-releasing materials, and evaluate the organic substrate (presented as chemical oxygen demand (COD) equivalent) and oxygen release rates from the organic-releasing material and oxygen-releasing materials, respectively. The observed oxygen and COD release rates were approximately 0.0368 and 0.0416 mg/d/g of material, respectively. A laboratory-scale column experiment was then conducted to evaluate the feasibility of this proposed system for the bioremediation of PCE-contaminated groundwater. This system was performed using a series of continuous-flow glass columns including a soil column, an organic-releasing material column, two consecutive soil columns, and an oxygen-releasing material column, followed by two other consecutive soil columns. Anaerobic acclimated sludges were inoculated in the first four columns, and aerobic acclimated sludges were inoculated in the last three columns to provide microbial consortia for contaminant biodegradation. Simulated PCE-contaminated groundwater with a flow rate of 0.25 L/d was pumped into this system. Effluent samples from each column were analyzed for PCE and its degradation byproducts. Results show that up to 99% of PCE removal efficiency was obtained in this passive system. Thus, the biobarrier treatment scheme has the potential to be developed into an environmentally and economically acceptable remediation technology for the in situ treatment of PCE-contaminated aquifer.

The prevalence of TT virus and GB virus C/hepatitis G virus infection in individuals with raised liver enzymes but without HBV or HCV infection in Taiwan

The prevalence of TT virus (TTV) and GB virus-C/hepatitis G virus (GBV-C/HGV) infection and the association with raised liver function tests in 546 Taiwanese with negative HBsAg, anti-HCV and HCV RNA was elucidated. They were tested for serum alanine aminotransferase (ALT), GBV-C/HGV RNA, anti-envelope protein 2 antibody (anti-E2) and TTV DNA. Direct sequencing and phylogenetic analyses were performed on 58 isolates for TTV genotype determination. The prevalence of TTV DNA, GBV-C/HGV RNA, anti-E2 and over all GBV-C/HGV exposure was 24.9, 3.4, 8.2 and 11.1%, respectively. Using uni- and multi-variate analyses, male gender and TTV viremia were associated significantly with raised ALT values. Sixty-nine percent of TTV isolates were deduced to be TTV genotype 1 and they had significantly lower mean age than genotype non-1 isolates. In the population, raised ALT may be related to male gender and be attributable to TTV infection but not to GBV-C/HGV among individuals with no evidence of current HBV and HCV infection. TTV genotype 1 is the most prevalent genotype and associated with younger age.

Changes in vesicourethral function following laparoscopic hysterectomy versus abdominal hysterectomy

OBJECTIVE

To assess whether total hysterectomy is associated with increased postoperative vesicourethral abnormalities.

SAMPLE

Forty-five patients had a laparoscopic hysterectomy and 36 patients had a total abdominal hysterectomy.

DESIGN

Before and after hysterectomy, patients underwent a urinalysis, a personal interview, and an urodynamic study.

RESULTS

Of the laparoscopic hysterectomy group, 27 patients (60%) exhibited urinary symptoms preoperatively, and 22 patients (48.9%) remained symptomatic following surgery. There was no significant change in the number of women with one or more urinary symptoms, but the incidence of urinary frequency and stress incontinence decreased significantly following hysterectomy (p < 0.05). Of the total abdominal hysterectomy group, preoperative voiding symptoms were present in 22 patients (61.1%). After surgery, urinary symptoms were present in 19 patients (52.8%). Some patients did not complain of any urinary frequency or stress incontinence following hysterectomy, but this figure did not differ significantly (p > 0.05). Maximal urethral closure pressure and maximal cystometric capacity demonstrated significant increases for both groups following surgery.

CONCLUSIONS

The results indicated that total hysterectomy, either laparoscopic or total abdominal hysterectomy, did not significantly increase the subjective and objective incidence of vesicourethral dysfunction. On the contrary, some patients experience a substantial improvement of pre-existing urinary frequency or stress incontinence, partly as a result of an increase in the maximal urethral closure pressure and total bladder capacity following hysterectomy.

Theoretical study of the internal rotational barriers in nitrotoluenes, nitrophenols, and nitroanilines

The molecular geometries and internal rotational barriers of the nitro group of 3-nitrotoluene (3-NT), 4-nitrotoluene (4-NT), 3-nitrophenol (3-NP), 4-nitrophenol (4-NP), 3-nitroaniline (3-NA), and 4-nitroaniline (4-NA) were calculated by five different types of density functional theory (DFT) methods with three different levels of basis sets. Analyses of the torsional angles of the nitro, methyl, amino, and hydroxyl groups indicate that 3-NP, and 4-NP are planar molecules, but 3-NT, 4-NT, 3-NA, and 4-NA are not planar molecules. Internal rotational barriers of the nitro group were calculated as the V2 barrier, and the NO2 torsional potentials for each molecule were given. The heights of the V2 barrier vary with the DFT methods, the basis sets, and the kinds and positions of substituents. The average values of the V2 barriers for 3-NT, 4-NT, 3-NP, 4-NP, 3-NA, and 4-NA are 6.44, 6.92, 6.64, 7.93, 6.38, and 9.13 kcal/mol, respectively. Torsional potentials of the OH and NH2 groups of nitrophenol and nitroaniline derivatives were also studied by a B3LYP/6-31G* approach. Except for the OH group in 2-NP, these derivatives have the V2 barrier.

The relationship between FTL and NA, DMV or CVLM in central cardiovascular control

The aim of the present study was to examine the relationship between the lateral tegmental field (FTL), a cardioinhibitory area, with other cardioinhibitory areas, i.e., the ambiguus nucleus (NA) and the dorsal motor nucleus of vagus (DMV) and the caudal ventrolateral medulla (CVLM), a vasopressor inhibitory area. In 55 cats anesthetized with chloralose (40 mg/kg) and urethane (400 mg/kg), the cardiovascular responses of heart rate (HR), systemic arterial blood pressure (SAP) and vertebral nerve activity (VNA) were recorded. The FTL, NA, DMV and CVLM were identified first by stimulation (rectangular pulses in 80 Hz, 0.5 ms, 50-100 microA) and then confirmed by microinjection of sodium glutamate (Glu, 0.25M, 70 nl). In studying the influence of NA, DMV, or CVLM lesion on the Gluinduced responses in FTL, kainic acid (KA, 24 mM, 100 nl) was microinjected into the NA, DMV or CVLM. FTL stimulation produced an average decrease of HR by 55%. After KA lesioning of the ipsilateral NA or the DMV, the decreased HR induced by FTL was significantly diminished. After subsequent lesion of the contralateral DMV or NA, the bradycardia of FTL was abolished. The reduction of resting HR was more intense after lesioning the NA than DMV and with the left side more than that of the right side. These studies suggest that the cardioinhibitory responses of FTL are mediated through both NA and DMV with predominance of the former, while the hypotensive effect of FTL is mediated through CVLM. The precise pathway responsible for the FTL-induced bradycardia and hypotension is to be determined.

Tumorigenesis induced by the HHV8-encoded chemokine receptor requires ligand modulation of high constitutive activity

ORF74 (or KSHV-vGPCR) is a highly constitutively active G protein-coupled receptor encoded by HHV8 that is regulated both positively and negatively by endogenous chemokines. When expressed in transgenic mice, this chemokine receptor induces an angioproliferative disease closely resembling Kaposi sarcoma (KS). Here we demonstrate that several lines of mice carrying mutated receptors deficient in either constitutive activity or chemokine regulation fail to develop KS-like disease. In addition, animals expressing a receptor that preserves chemokine binding and constitutive activity but that does not respond to agonist stimulation have a much lower incidence of angiogenic lesions and tumors. These results indicate that induction of the KS-like disease in transgenic mice by ORF74 requires not only high constitutive signaling activity but also modulation of this activity by endogenous chemokines.

Disruption of neutrophil migration in a conditional transgenic model: evidence for CXCR2 desensitization in vivo

We developed transgenic mice conditionally expressing the neutrophil chemoattracting chemokine KC and the beta-galactosidase gene in multiple tissues. In these transgenic mice, doxycycline treatment induced a strong up-regulation in the expression of KC in several tissues, including heart, liver, kidney, skin, and skeletal muscle. Expression of KC within these tissues led to a rapid and substantial increase in the serum levels of KC (serum KC levels were higher than 200 ng/ml 24 h after treatment). Accordingly, beta-galactosidase expression was also detected after injection of doxycycline and was highest in skeletal muscle, pancreas, and liver. Surprisingly, despite expression of KC in multiple tissues, no neutrophil infiltration was observed in any of the tissues examined, including skin. Doxycycline treatment of nontransgenic mice grafted with transgenic skin caused dense neutrophilic infiltration of the grafts, but not the surrounding host skin, indicating that the KC produced in transgenic tissues was biologically active. In separate experiments, neutrophil migration toward a localized source of recombinant KC was impaired in animals overexpressing KC but was normal in response to other neutrophil chemoattractants. Analysis of transgenic neutrophils revealed that high concentrations of KC in transgenic blood had no influence on L-selectin cell surface expression but caused desensitization of the receptor for KC, CXCR2. These results confirm the neutrophil chemoattractant properties of KC and provide a mechanistic explanation for the paradoxical lack of leukocyte infiltration observed in the presence of elevated concentrations of this chemokine.

Reoperative Snodgrass procedure

PURPOSE

We examine the results of a reoperative Snodgrass procedure for complex hypospadias.

MATERIALS AND METHODS

A total of 25 patients with hypospadias in whom repair had failed underwent a reoperative Snodgrass procedure. Mean patient age and number of prior repairs were 11.4 years and 2.5, respectively. Before this treatment the meatus was at the distal shaft in 10 cases, mid shaft in 9, proximal shaft in 4 and penoscrotal junction in 2. Preoperatively the associated complications were fistulas in 13 patients, residual chordee in 12 and diverticulum in 1. In 8 cases the fistula was incorporated into the hypospadiac opening and treated as a longer defect. The urethral plates were, subjectively, surgically altered or unaltered in 7 and 18 patients, respectively. In 8 patients (group A) the previous repair(s) did not involve dissection of the urethral plate (unaltered) nor was there a fistula. The remaining 17 patients were classified as group B. The neourethra was then reconstructed as the Snodgrass technique. Followup urethral calibration was performed in 17 patients.

RESULTS

Mean followup period was 13.7 months. Mean length and size of neourethra were 19.9 mm. and 14Fr, respectively. There were 7 (28%) postoperative fistulas of the neourethra. The incidences of postoperative fistula of the neourethra were 0% and 41.2% in groups A and B, respectively (p <0.01). Statistically the surgically altered urethral plate and the presence of a preoperative fistula were 2 independent factors predicting a higher postoperative fistula rate. The overall postoperative meatal stenosis rate was 13 (52%) with 3 (37.5%) in group A and 10 (58.8%) in group B, respectively (p >0.05). The meatal stenosis was treated with simple dilation in 11 cases and meatoplasty during subsequent fistula repair in 2. Stricture at the anastomostic site between the normal urethra and neourethra was noted in 2 patients. Fistula repair was successfully performed 6 months later in 4 patients.

CONCLUSIONS

The Snodgrass procedure is a viable option for the treatment of previously failed hypospadias repair. It was highly effective in patients with a surgically unaltered urethral plate and no preoperative fistula.

GB virus C/hepatitis G virus infection in chronic hepatitis C patients with and without interferon-alpha therapy

GB virus C/hepatitis G virus (GBV-C/HGV) RNA, detected by polymerase chain reaction, and antibodies to the GBV-C/HGV envelope protein (anti-E2), detected by an enzyme-linked immunosorbent assay, were used to evaluate both the impact of GBV-C/HGV on the coexistent hepatitis C virus (HCV) infection and the course of GBV-C/HGV infection in chronic hepatitis C patients with and without interferon-alpha (IFN-alpha) treatment. Of the 162 chronic hepatitis C patients treated with INF-alpha, 17.9% were GBV-C/HGV RNA-positive and 18.5% anti-E2-positive (total exposure, 35.2%). Neither present nor past GBV-C/HGV infection had impact on the clinical features, HCV virological characteristics and response to IFN-alpha treatment in chronic hepatitis C patients. Among patients with ongoing HCV/GBV-C/HGV coinfection, 20.7% (6/29) in IFN-alpha-treated patients lost GBV-C/HGV RNA concomitant with anti-E2 seropositivity, which was significantly higher than 4.8% (2/42) in patients without INF-alpha treatment (P<0.05). Based on multivariate analyses, the significant factors associated with clearance of GBV-C/HGV viremia combined with anti-E2 seropositivity were baseline anti-E2 seropositivity and IFN-alpha treatment. In summary, GBV-C/HGV did not alter the course of coexistent HCV. IFN-alpha treatment was effective in some patients against GBV-C/HGV and might facilitate anti-E2 seroconversion in chronic hepatitis C patients with GBV-C/HGV viremia.

Modified approach of hand-assisted laparoscopic nephroureterectomy for transitional cell carcinoma of the upper urinary tract

Objectives. To report a modified approach for hand-assisted laparoscopic nephroureterectomy (HALNU).Methods. Seven patients with localized transitional cell carcinoma of the upper urinary tract underwent unilateral HALNU. Patients were placed in a 60 degrees oblique position during the entire procedure. Via a 7-cm Gibson incision on the lesion side, the distal ureterectomy and bladder cuff excision were done by an open method without opening the bladder. Then, with the surgeon's hand inserted into the peritoneal cavity by way of the same wound, HALNU was performed with two to three additional laparoscopic ports. The perioperative parameters were compared with those of 15 cases of conventional open nephroureterectomy.Results. Patients in the HALNU group had significantly less mean blood loss (140 versus 455 mL) and earlier resumption of oral intake (33 versus 61 hours), required fewer narcotics (38 versus 70 mg of morphine sulfate equivalent), and were discharged earlier (7.33 versus 9.1 days), with a faster convalescence to normal activity (3.7 versus 5.6 weeks; all P < 0.05). The total mean surgical time was 3.7 hours for the HALNU group.Conclusions. Our approach used the same incision to both excise the distal ureter and apply the hand-assist device. It also preserved the benefits of the minimal invasiveness of laparoscopic surgery compared with its open counterpart.

External beam radiation therapy for inoperable hepatocellular carcinoma with portal vein thrombosis

Portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC) has a poor impact on prognosis. Many of these tumors may cause intrahepatic and extrahepatic metastases. From January 1991 to December 1996, 41 unresectable HCC patients with PVT underwent transcatheter arterial chemoembolization (TACE) and external beam radiation therapy (EBRT) to the portion of PVT. The irradiated field, with a mean equivalent field size of 6.6 x 7.1 cm2, was localized and simulated by abdominal sonography, angiography and computed tomography. Radiation dose ranged from 36 to 66 Gy (mean dose: 51.4 Gy), in a daily fraction of 1.8 to 2 Gy. The response of EBRT was evaluated by abdominal sonography within 3 months of completion of EBRT. The response rates of the PVT after treatment were 39% for complete response (CR), 41% for partial response (PR), and 19% for no response (NR), respectively. The median overall survival time from start of radiotherapy was 10 months for all patients, 17 months for CR patients, 8 months for PR patients and 4 months for NR patients. By multivariate analysis, response of PVT resulted in a significant improvement in survival. (P = 0.001) There was no occurrence of severe complication of radiation-induced liver disease. The results obtained with combined treatment modality of EBRT and TACE in the treatment of HCC patients with PVT are encouraging.

A comparison of dermatologists' and primary care physicians' accuracy in diagnosing melanoma: a systematic review

OBJECTIVE

To compare the accuracy of dermatologists and primary care physicians (PCPs) in identifying pigmented lesions suggestive of melanoma and making the appropriate management decision to perform a biopsy or to refer the patient to a specialist.

DATA SOURCES

Studies published between January 1966 and October 1999 in the MEDLINE, EMBASE, and CancerLit databases; reference lists of identified studies; abstracts from recent conference proceedings; and direct contact with investigators. Medical subject headings included melanoma, diagnosis, screening, primary care, family practitioner, general practitioner, internal medicine, dermatologist, and skin specialist. Articles were restricted to those involving human subjects.

STUDY SELECTION

Studies that presented sufficient data to determine the sensitivity and specificity of dermatologists' or PCPs' ability to correctly diagnose lesions suggestive of melanoma and to perform biopsies on or refer patients with such lesions.

DATA EXTRACTION

Two reviewers independently abstracted data regarding the sensitivity and specificity of the dermatologists and PCPs for diagnostic and biopsy or referral accuracy. Disagreements were resolved by discussion. The quality of the studies was also evaluated.

DATA SYNTHESIS

Thirty-two studies met inclusion criteria; 10 were prospective studies. For diagnostic accuracy, sensitivity was 0.81 to 1.00 for dermatologists and 0.42 to 1.00 for PCPs. None of the studies reported specificity for dermatologists; one reported specificity for PCPs (0.98). For biopsy or referral accuracy, sensitivity ranged from 0.82 to 1.00 for dermatologists and 0.70 to 0.88 for PCPs; specificity, 0.70 to 0.89 for dermatologists and 0.70 to 0.87 for PCPs. Receiver operating characteristic curves for biopsy or referral ability were inconclusive.

CONCLUSIONS

The published data are inadequate to demonstrate differences in dermatologists' and PCPs' diagnostic and biopsy or referral accuracy of lesions suggestive of melanoma. We offer study design suggestions for future studies.

The effects on vesicourethral function following laparoscopic hysterectomy

The aim of our study is to determine whether laparoscopic hysterectomy is associated with increased postoperative urinary symptoms and to assess the change in urodynamic parameters after operation. Forty-five women were arranged for laparoscopic hysterectomy (LH). Each patient received urinalysis, interview, and urodynamic study including uroflowmetry, filling and voiding cystometry and urethral pressure profilometry before and after hysterectomy. A total of 27 patients (60%) had urinary symptoms preoperatively. After operation, only 22 patients (48.9%) remained symptomatic. There was no significant change in the number of women with one or more voiding symptoms before and after surgery, but the incidence of urinary frequency and stress incontinence decreased significantly after laparoscopic hysterectomy (P < 0.05). In addition, maximal urethral closure pressure and maximal cystometric capacity showed significant increases after operation. They were 73.1 cm H2O (range: 49-114) vs 104.4 cm H2O (range: 60-147) (P < 0.001), and 363.3 ml (range: 287-423) vs 396.1 ml (range: 265-515) (P < 0.001), respectively. The result indicated that laparoscopic hysterectomy did not significantly increase the subjective or objective incidence of vesicourethral dysfunction. On the contrary, some patients might be cured of urinary frequency or stress incontinence postoperatively.

Pseudo-Meigs syndrome and elevated levels of tumor markers associated with benign ovarian tumors--two case reports

Elevated tumor markers for a post-menopausal woman presenting with a multilocular adnexal mass, ascites, and pleural effusion were interpreted as being highly suspicious of malignancy. This paper describes two cases of ovarian tumors presenting with all signs of malignancy. Following surgical excision of the masses, and histopathological assay, a benign pure struma ovarii and a mucinous cystadenoma were diagnosed by pathologists. The immediate and complete resolution of symptoms were achieved post-operatively, and the previously-evident abnormal tumor markers rapidly declined to the normal range, the two tumors were subsequently classified as pseudo-Meigs' syndromes.

Changing prevalence of hepatitis C virus genotypes: molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan

To determine the hepatitis C virus (HCV) genotype distribution in Taiwan and to clarify the relationship between genotype and the pathogenesis of HCV infection, 1,164 subjects positive for serum HCV antibodies and HCV RNA from three HCV hyperendemic areas (Masago, Tzukuan, and Taoyuan) and a tertiary referral center in Taiwan were studied during 1995-1997. HCV genotypes and viral loads were determined using Okamoto's method and branched DNA assay, respectively. Genotype 1b was the most prevalent in Tzukuan (61.9%), Taoyuan (76.9%), and the referral center (47.0%). By contrast, genotype 2a was the major HCV type in Masago (63.5%). Prevalence of genotype 1b positively and that of genotype 2a negatively correlated to age, regardless of study populations (P < 0.01). Based on multivariate analysis, the significant factors associated with the presence of cirrhosis, with or without hepatocellular carcinoma, in chronic hepatitis C patients were genotype 1b and age. In conclusion, these results underline that independent HCV outbreaks continue in HCV hyperendemic areas in Taiwan, concomitant with a changing relative prevalence of HCV genotypes in relation to age. Both the correlation of genotype 1b with age (cohort effect) and intrinsic properties of HCV genotypes are probably responsible for the association between genotype and the pathogenesis of HCV infection.

Inhibition of methyl-n-amylnitrosamine hydroxylation by diallyl sulfide and phenethylisothiocyanate in the rat

Formation of the stable 2-, 3-, and 4-hydroxy derivatives of methyl-n-amylnitrosamine (MNAN) probably reflects cytochrome P-450-catalyzed activation of MNAN by 1-hydroxylation. Here we studied inhibition of the oxidation of MNAN to hydroxy-MNANs (HO-MNANs) by freshly excised tissues from MRC-Wistar rats treated with the vegetable-derived chemicals diallyl sulfide (DAS) and phenethylisothiocyanate (PEITC). Rats were gavaged with DAS (200 mg/kg), PEITC (163 mg/kg), or vehicle (corn oil) alone. After various times, the rats were killed, the esophagus, nasal mucosa, and liver were removed, and the tissues/tissue slices were incubated for two hours with 23 microM MNAN. HO-MNAN formation was measured by gas chromatography-thermal energy analysis. Significant (p < 0.01) 72-75%, 40%, and 44% inhibitions of total HO-MNAN formation were observed for nasal mucosa removed at 3-18 hours, for esophagus at 18 hours, and for liver at 3 hours, respectively, after gavage of DAS. Significant (p < 0.03) 46-75% inhibition of HO-MNAN formations was observed for the esophagus at 2-24 hours after gavage of PEITC. In disposition studies, rats were treated with DAS (200 mg/kg) in corn oil and sacrificed after various intervals. DAS was determined by gas chromatography of tissue homogenate extracts. After gavage of DAS, its total recovery from all tissues studied was 27% of the dose after 45 minutes and 15-19% after 90 and 180 minutes, with > 80% of the recovered DAS in the stomach contents. Up to 2% per tissue of the recovered DAS was found in the stomach wall, liver, and blood. After intraperitoneal injection of DAS, < or = 2% of the dose was recovered in the blood and < or = 0.7% in the liver. Hence, gavage of DAS and PEITC significantly inhibited HO-MNAN formation for up to 18 and 24 hours, respectively, whereas DAS was > 80% metabolized 90 minutes after its gavage. These findings suggest that long-lasting inhibitors or their metabolites, or inactivation of P-450 enzymes, were responsible for the persistence of inhibition of MNAN metabolism.

Health status of mothers of adults with intellectual disability

A cross-sectional survey was conducted to describe the health of mothers of adults with intellectual disability (ID), and the influence of the mother's and her adult child's characteristics on her health. The sample consisted of 108 mothers divided into mid-life and later-life groups. Four service agencies mailed SF-36 forms and demographic questionnaires to their clients. The return rate from primary caregivers was 70%. The physical and the mental components of health of both groups of mothers were found to be similar to or better than those of their counterparts in the US national norms. Arthritis was found to influence the physical health of both groups of mothers. Employment was found to influence physical health of the mid-life mothers, while family income was found to influence mental health of the later-life mothers. The characteristics of adults with ID did not influence the mothers' health significantly. Mothers' caregiving for their adult children with ID might not be as detrimental to the mid-life mothers' physical component of health as it might be to the later-life mothers. Further studies are needed.

Hepatic MR imaging using ferumoxides: prospective evaluation with surgical and intraoperative sonographic confirmation in 25 cases

OBJECTIVE

The purpose of our study was to evaluate the sensitivity and accuracy of ferumoxides-enhanced MR imaging in comparison with surgery and intraoperative sonography.

SUBJECTS AND METHODS

We prospectively evaluated 25 consecutive studies in 24 patients who underwent ferumoxides-enhanced hepatic MR imaging before surgery and intraoperative sonography. Both 1.5-T scanners (13 cases) and 0.2-T scanners (12 cases) were used. Turbo spin-echo T2-weighted sequences were performed before and after the administration of ferumoxides and the images were compared. Lesions were classified as solid or nonsolid and tabulated on standard liver maps. The liver maps from MR imaging were compared with those from surgery and intraoperative sonography. For lesions greater than 1 cm, the regions of interest were measured and contrast-to-noise ratio was calculated.

RESULTS

Of 93 solid lesions found at surgery, 69 were seen on unenhanced MR imaging (sensitivity, 74.2%) and 87 were seen on ferumoxides-enhanced MR imaging (sensitivity, 93.5%) (p < 0.05). Of the seven benign lesions (five cysts, two hemangiomas) found at surgery, all were correctly identified as benign on MR imaging. Two lesions identified as solid before surgery were not found at surgery. Mean lesion contrast-to-noise ratio for the unenhanced scans was 22.9 and 34.5 (p < 0.001) for the ferumoxides-enhanced scans. Subanalysis of 1.5- and 0.2-T MR imaging revealed similar results with significant (p < 0.05) increases in sensitivity for both. The average size of the lesions missed before surgery was 0.7 cm.

CONCLUSION

Turbo spin-echo T2-weighted ferumoxides-enhanced MR imaging at either 1.5 or 0.2 T has value in preoperative liver assessment.

Methanofollis aquaemaris sp. nov., a methanogen isolated from an aquaculture fish pond

A novel methanogen, designated strain N2F9704T, was isolated from an aquaculture fish pond near Wang-gong, Taiwan. The cells were irregular cocci, non-motile, 1.2-2.0 microm in diameter and stained gram-negative. Cells of strain N2F9704T lysed easily by SDS treatment (0.1 g l(-1)) and the S-layer protein had an Mr of 137000. The catabolic substrates used included formate and H2+CO2, but not acetate, methanol, trimethylamine or secondary alcohols. The optimal growth parameters for strain N2F9704T were pH 6.5, 37 degrees C with 0.5% NaCl. Trace amounts of tungstate not only promoted growth but also extended the range of growth conditions. Analysis of the 16S rDNA sequence revealed a phylogenetic relationship to Methanofollis species and the name Methanofollis aquaemaris sp. nov. is therefore proposed for strain N2F9704T (= OCM 746T = CCRC 16166T). Additionally, the strain was infected with a novel coccus-shaped, enveloped virus with a diameter of 200 nm.

Correlations between theoretical and experimental determination of heat of formation of certain aliphatic nitro compounds

Heats of formation of energetic materials were calculated by Dewar's AM1 and Stewart's PM3 methods. In order to compare the theoretical results with the experimental ones, some correlation models were proposed in this study. Correlations were evaluated by multivariable linear regression method, considering the number of nitro groups and the use of quadratic relations involving the number of carbon, hydrogen, nitrogen, and oxygen atoms. Results indicated very precise correlations. Based on these correlations, heats of formation of some aliphatic nitro compounds can be predicted at 95% predictive interval without experimental analysis.

Treatment guideline of enuresis in Taiwan

The treatment guideline of enuresis suggested by the study group of enuresis in Taiwan is reported. Medical consultation and treatment of enuresis are recommended at the age of 5 and 6 years respectively. Evaluation of the enuretic children includes history taking, physical examination and laboratory investigations. A checklist is provided for quick evaluation in busy clinics. Urinalysis, urine specific gravity and office ultrasonography are essential tests. An algorithm of treatment of monosymptomatic enuresis is constructed. The two main options of treatment are behavioral modification with alarm system and pharmacotherapy with desmopressin or imipramine. Imipramine is recommended as one of the treatment options because of its relative safety in Taiwan. However the potential toxicity and mortality of imipramine is highlighted and warned. The responses to treatment are evaluated after a period of treatment for 1 to 3 months. Further evaluation and individualized treatment is suggested for poor responders.

Evaluation of TCDD biodegradability under different redox conditions

Polychlorinated dibenzo-p-dioxins have been generated as unwanted by-products in many industrial processes. Although their widespread distribution in different environmental compartments has been recognized, little is known about their fate in the ultimate environment sinks. The highly stable dioxin isomer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been called the most toxic compound known to man. In this laboratory microcosm study, TCDD bioavailability was evaluated under five reduction/oxidation (redox) conditions including aerobic biodegradation, aerobic cometabolism, methanogenesis, iron reduction, and reductive dechlorination. Activated sludge and aquifer sediments from a TCDD and a pentachlorophenol (PCP) contaminated site were used as the inocula. Acetate, sludge cake, and cane molasses were used as the primary substrates (carbon sources) in cometabolism and reductive dechlorination microcosms. After a 90-day incubation period, microcosms constructed under reductive dechlorination conditions were the only treatment showing promising remediation results. The highest TCDD degradation rate [up to 86% of TCDD removal (with an initial concentration of 96 microg/kg of soil)] was observed in the microcosms with anaerobic activated sludge as the microbial inocula and sludge cakes as the primary substrates. Except for reductive dechlorination microcosms, no significant TCDD removal was observed in the microcosms prepared under other conditions. Thus, application of an effective primary substrate to enhance the reductive dechlorination process is a feasible method for TCDD bioremediation. Bioremediation expense can be significantly reduced by the supplement of some less expensive alternative substrates (e.g., sludge cakes, cane molasses). Results would be useful in designing a scale-up in situ or on-site bioremediation system such as bioslurry reactor for field application.

Depentylation of the rat esophageal carcinogen, methyl-n-pentylnitrosamine, by microsomes from various human and rat tissues and by cytochrome P450 2A3

Methyl-n-pentylnitrosamine (MPN) is carcinogenic for the rat esophagus. To determine organ specificity for MPN activation by human tissues, microsomes isolated from human organs (snap-frozen <6 h after death or removed surgically) were incubated with [pentyl-(3)H]MPN, and [(3)H]pentaldehyde formation was measured by high-pressure liquid chromatography of its 2,4-dinitrophenylhydrazone using radioflow assay. With 100 microM MPN, mean depentylation rates were 6.6 (liver), 2.9 to 3.8 (kidney, stomach, small intestine, and colon), and 0.4 to 1.6 (esophagus, lung, and skin) pmol of pentaldehyde/mg of protein/min. Of 14 human esophagi, four showed relatively high depentylation rates of 3.3 to 4.1 pmol/mg/min. Apparent K(m) was 80 to 160 microM (V(max), 3-15 pmol/mg/min) for three esophagi, 90 to 130 (2 livers), and 1330 (1 kidney) microM. Rat tissues showed mean depentylation rates for 100 microM MPN of 24.9 (liver), 14.5 (esophagus), 7.0 (lung), and 0.0 to 2.7 (5 other tissues) pmol/mg/min. MPN depentylation by rat cytochrome P450 2A3 showed an apparent K(m) of 8 microM (V(max), 70 pmol/nmol of P450/min) and was competitively inhibited by the CYP2A inhibitor coumarin (apparent K(i), 4 microM). Coumarin (0.4 mM) inhibited microsomal depentylation of 100 microM MPN by 37 to 62% for human esophagus, liver, kidney, and colon and for rat esophagus but not for rat liver and lung. MPN depentylation by rat esophageal microsomes increased up to 90% on adding P450 reductase. The results indicate organ-specific MPN metabolism by rat but not human esophagus. Nevertheless, the relatively high activity of four human esophagi might indicate increased susceptibility of some individuals to carcinogenesis by unsymmetrical dialkylnitrosamines.

Laboratory column studies for evaluating a barrier system for providing oxygen and substrate for TCE biodegradation

The industrial solvent trichloroethylene (TCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop a biobarrier system containing oxygen-organic releasing material to enhance the aerobic cometabolism of TCE in situ. The oxygen-organic material, which contains calcium peroxide and peat, is able to release oxygen and primary substrates continuously upon contact with water. Batch experiments were conducted to design and identify the components of the oxygen-organic releasing material, and evaluate the oxygen and organic substrate (presented as COD equivalent) release from the designed oxygen-organic material. The observed oxygen and chemical oxygen demand (COD) release rates were approximately 0.0246 and 0.052 mg/d/g of material, respectively. A laboratory-scale column experiment was then conducted to evaluate the feasibility of this proposed system for the bioremediation of TCE-contaminated groundwater. This system was performed using a series of continuous-flow glass columns including a soil column, an oxygen-organic material column, followed by two consecutive soil columns. Aerobic acclimated sludges were inoculated in all three soil columns to provide microbial consortia for TCE biodegradation. Simulated TCE-contaminated groundwater with a flow rate of 0.25 l/day was pumped into this system. Effluent samples from each column were analyzed for TCE and other indicating parameters (e.g., pH, dissolved oxygen). Results show that the decreases in TCE concentrations were observed over a 4-month operating period. Up to 99% of TCE removal efficiency was obtained in this passive system. Results indicate that the continuously released oxygen and organic substrates from the oxygen-organic materials enhanced TCE biotransformation. Thus, the biobarrier treatment scheme has the potential to be developed into an environmentally and economically acceptable remediation technology.

Ultrasonic characteristics of periportal collateral circulation in hepatocellular carcinoma with portal vein invasion

Real-time ultrasound (US) was used to analyze the morphological characteristics of periportal collateral circulation (PPCC) and the hepatic artery in hepatocellular carcinoma (HCC) patients with portal vein invasion (PVI). During a 5-year interval, a total of 17 HCC patients with main portal vein thrombosis and detectable periportal vessels were collected: 14 men and 3 women, aged 27 to 76 years old. We examined these patients' periportal vessels by real-time US, then differentiated PPCC from hepatic artery by duplex Doppler US. We analyzed the morphological appearances of real-time US imaging of PPCC and the hepatic artery. Our results showed that the PPCC was always torturously worm-like in appearance on real-time US, and the hepatic artery usually had a linear channel appearance on real-time US. When these two kinds of vessels were seen simultaneously along the pathway of a thrombosed portal vein, the inner vessel was always the hepatic artery with linear channel structure, and the outer vessel was always PPCC with a torturously worm-like structure. In conclusion, real-time US is a useful and reliable modality in detecting periportal vessels and differentiating PPCC from the hepatic artery.

A methodology for evaluation of boundary detection algorithms on breast ultrasound images

Image segmentation is the partition of an image into a set of non-overlapping regions that comprise the entire image. The image is decomposed into meaningful parts, which are uniform with respect to certain characteristics, such as grey level or texture. This study presents a novel methodology to evaluate ultrasound image segmentation algorithms. The sonographic features can differentiate between various sized malignant and benign breast tumours. The clinical experiment can determine whether a tumour is benign or not, based on contour, shape, echogenicity and echo texture. Further study of the standardized sonographic features, especially the tumour contour and shape, will improve the positive predictive value and accuracy rate in breast tumour detection. The effectiveness of using this methodology is illustrated by evaluating image segmentation on breast ultrasound images. Via definite segmentation, the appreciated tumour shape and contour can be ascertained. Furthermore, this method can enhance the ability of ultrasound to distinguish between benign and malignant breast lesions.

Ubiquitous transgenic expression of the IL-23 subunit p19 induces multiorgan inflammation, runting, infertility, and premature death

p19, a molecule structurally related to IL-6, G-CSF, and the p35 subunit of IL-12, is a subunit of the recently discovered cytokine IL-23. Here we show that expression of p19 in multiple tissues of transgenic mice induced a striking phenotype characterized by runting, systemic inflammation, infertility, and death before 3 mo of age. Founder animals had infiltrates of lymphocytes and macrophages in skin, lung, liver, pancreas, and the digestive tract and were anemic. The serum concentrations of the proinflammatory cytokines TNF-alpha and IL-1 were elevated, and the number of circulating neutrophils was increased. In addition, ubiquitous expression of p19 resulted in constitutive expression of acute phase proteins in the liver. Surprisingly, liver-specific expression of p19 failed to reproduce any of these abnormalities, suggesting specific requirements for production of biologically active p19. Bone marrow transfer experiments showed that expression of p19 by hemopoietic cells alone recapitulated the phenotype induced by its widespread expression, pointing to hemopoietic cells as the source of biologically active p19. These findings indicate that p19 shares biological properties with IL-6, IL-12, and G-CSF and that cell-specific expression is required for its biological activity.

Application of microbial enumeration technique to evaluate the occurrence of natural bioremediation

Natural bioremediation is believed to be the major processes that account for both containment of the petroleum-hydrocarbon plume and reduction of the contaminant concentrations. In this study, the feasibility of applying the microbial enumeration technique was assessed for natural biodegradation evaluation at three selected gasoline spill sites. At each site, two monitor wells were installed along the groundwater flow, and one multilevel sampler (MLS) was installed to delineate the vertical distribution of the contaminant plume. Two continuous soil cores were collected at each site to evaluate the horizontal distribution of the microbial activity. Soil samples were used for microbial enumeration, grain-size distribution analysis, and sediment extraction. In situ tracer study was performed using 1,2,4-trimethylbenzene (1,2,4-TMB) as the tracer to study the efficiency of contaminant biodegradation. Investigation results demonstrate the agreement between microbial enumeration and other evaluation techniques for natural bioremediation (e.g., geochemical indicator analysis, tracer study). Results suggest that the microbial enumeration is useful in assessing the occurrence, efficiency, and status of the bioremediation. Because this technique provides insight into factors controlling contaminant biodegradation, it could be performed as the supplemental method for natural bioremediation evaluation at petroleum-hydrocarbon spill sites.

Development of a biobarrier for the remediation of PCE-contaminated aquifer

The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop a biobarrier system, which includes a peat layer to enhance the anaerobic reductive dechlorination of PCE in situ. Peat was used to supply primary substrate (electron donor) continuously. A laboratory-scale column experiment was conducted to evaluate the feasibility of this proposed system or PCE removal. This experiment was performed using a series of continuous-flow glass columns including a soil column, a peat column, followed by two consecutive soil columns. Anaerobic acclimated sludges were inoculated in all three soil columns to provide microbial consortia for PCE biodegradation. Simulated PCE-contaminated groundwater with a flow rate of 0.25 l/day was pumped into this system. Effluent samples from each column were analyzed for PCE and its degradation byproducts (trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), vinyl chloride (VC), ethylene (ETH), and ethane). Results show that the decrease in PCE concentrations and production of PCE byproducts were observed over a 65-day operating period. Up to 98%, of PCE removal efficiency was obtained in this passive system. Results indicate that the continuously released organics from peat column enhanced PCE biotransformation. Thus, the developed biobarrier treatment scheme has the potential to be developed into a cost-effective in situ PCE-remediation technology, and can be utilized as an interim step to aid in system scale-up.

Influence of hepatitis C virus on the profiles of patients with chronic hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the most common causes of chronic liver disease, cirrhosis and hepatocellular carcinoma. The influence of HCV infection on the clinicopathological and virological profiles of chronic HBV infection was investigated.

METHODS

A total of 100 chronic HBV carriers with histopathological diagnoses by liver biopsy were studied. Hepatitis B e antigen (HBeAg) and anti-HCV antibody were tested. Serum HCV-RNA was detected by using a nested reverse transcription-PCR assay. A branched DNA (bDNA) assay was used to detect HBV-DNA and quantitate the serum levels.

RESULTS

Eighteen (18%) of 100 patients were positive for anti-HCV and HCV-RNA. Patients with concurrent HCV and HBV infection were significantly older than those without HCV infection (P < 0.05). The positive rates of HBeAg and HBV-DNA as well as the serum levels of HBV-DNA in patients with concurrent HCV and HBV infection were significantly lower than those without concurrent HCV and HBV infection (P < 0.01, P < 0.05, and P < 0.001, respectively). By using multivariate analysis, the factors of seroconversion of HBeAg and decreasing level of HBV-DNA were significantly correlated to concurrent HCV and HBV infection in chronic HBV carriers. The factors of increasing age and concurrent HCV and HBV infection were significantly correlated to seroconversion of HBeAg.

CONCLUSIONS

The concurrent HCV and HBV infection in chronic HBV carriers might result in a suppression of HBV replication that presented with a lower level of serum HBV-DNA and HBeAg seroconversion. Nevertheless, neither more obvious increase in biochemical parameters nor histopathological progression to more advanced liver diseases was observed.