Photooxidation of azo dye reactive black 5 using a novel supported iron oxide: heterogeneous and homogeneous approach

Photooxidation of azo dye Reactive Black 5 (RB5) by H202 was performed with a novel supported iron oxide in a batch reactor in the range of pH 2.5-6.0. The iron oxide was prepared through a fluidized-bed reactor (FBR) and much cheaper than the Nafion-based catalysts. Experimental results indicate that the iron oxide can significantly accelerate the degradation of RB5 under the irradiation of UVA light (wavelength = 365 nm). An advantage of the catalyst is its long-term stability, which was confirmed through using the catalyst for multiple runs in the degradation of RB5. In addition, this study focused mainly on determining the proportions of homogeneous catalysis and heterogeneous catalysis in the batch reactor. Conclusively, although heterogeneous catalysis contributes primarily to the oxidation of RB5 during pH 4.5-6.0, the homogeneous catalysis is of increasing importance below pH 4.0 because of the Fe ions leaching from the catalyst to solution.

Electron microscopic examination of the viromatrix of Rana grylio virus in a fish cell line

Rana grylio virus (RGV), a Ranavirus belonging to the family Iridoviridae, assembles in the viromatrix which is a factory for viral genome replication and particle assembly. Ultrastructural studies of the viromatrix will clarify the pathway of assembly. The viromatrix and quantitative changes in RGV infected epithelipma papulosum cyprini (EPC) cells, one of fish cell lines, were studied by electron microscopy. It was shown that viromatrices were adjacent to the nucleus, and the electron density was lower than that of the surrounding cytoplasm. The viromatrix contained virus particles with different forms, electron-dense materials and amorphous structures which included tubules and membranous materials. Tubules were often observed in direct continuity with empty capsids. Several bundles of intermediate filaments were seen alongside the viromatrix and crystalline aggregates. Large clusters of mitochondria occurred in proximity to viromatrix. A total of 990 cells profiles were examined. The results showed that 394 cells contained viromatrix: 89.3% contained one, and 10.7% contained two to four viromatrices. The number of viromatrices increased gradually and reached a peak at 16 h p.i. The viromatrix area at 24 h p.i. increased up to 7.4 +/- 0.69 microm(2) which was three-times lower than that at 6 h p.i. The number of empty capsids within viromatrix was generally more than that of "full" particles at different time points, and there was a strong positive correlation between them.

Distribution of human chemokine (C-X3-C) receptor 1 (CX3CR1) gene polymorphisms and haplotypes of the CC chemokine receptor 5 (CCR5) promoter in Chinese people, and the effects of CCR5 haplotypes on CCR5 expression

Two chemokine (C-X3-C) receptor 1 (CX3CR1) gene polymorphisms, V249I and T280M, and 10 CC chemokine receptor 5 (CCR5) promoter haplotypes, P1-P10, have recently been reported to influence the progression of acquired immune-deficiency syndrome (AIDS). As these studies were performed mainly with Caucasian and African-American subjects, we determined the distribution of these alleles in Chinese people for the purpose of predicting possible clinical responses to the human immunodeficiency virus type 1 (HIV) epidemics in countries with significant Chinese populations, as well as to establish their effects on the expression of surface CCR5. Ninety-six HIV-negative Chinese individuals in Taiwan were subjected to genotyping, and we thus determined that the allelic frequencies of CX3CR1V249I and T280M changes were 2.6% and 2.1%, respectively, which were lower than found in Caucasians (25.5% and 14.0%, respectively). Unlike the previous reports, we only detected CCR5P1 and P4 haplotypes in Taiwanese people, and the P1/P1, P1/P4 and P4/P4 genotype frequencies were 21.0%, 41.1% and 37.9%, respectively. The sequencing data confirmed the results of previous studies, showing that CCR5P1 exhibited a complete linkage disequilibrium with a polymorphic allele 59029A present in the CCR5 promoter. Furthermore, fluorescence-activated cell sorter analysis revealed that, in the absence of the CCR2-64I mutation, individuals carrying CCR5P1 tended to express more surface CCR5 on monocytes and CD4+ cells. Therefore, this study not only reports the frequencies for the CX3CR1 and CCR5 promoter haplotypes in a Chinese population living in Taiwan, but also identifies a statistical link between the P1/P1 haplotype and the elevated CCR5 expression levels in the study group.

Vitamin B6 deficiency decreases the glucose utilization in cognitive brain structures of rats

The effects of vitamin B(6) deficiency on metabolic activities of brain structures were studied. Male Sprague-Dawley weanling rats received one of the following diets: (1) 7 mg pyridoxine HCl/kg (control group); (2) 0 mg pyridoxine HCl/kg (vitamin B(6)-deficient group); or (3) 7 mg pyridoxine HCl/kg with food intake restricted in quantity to that consumed by the deficient group (pair-fed control group). After 8 weeks of dietary treatment, rats in all three groups received an intravenous injection of 2-deoxy-[(14)C] glucose (100 microCi/kg). Vitamin B(6) status was evaluated by plasma pyridoxal 5'-phosphate concentrations. The vitamin B(6)-deficient group had significantly lower levels of plasma pyridoxal 5'-phosphate than did the control and pair-fed groups. The local cerebral glucose utilization rates in structures of the limbic system, basal ganglia, sensory motor system, and hypothalamic system were determined. The local cerebral glucose utilization rates in each of the four brain regions in the deficient animals were approximately 50% lower (P < 0.05) than in the control group. Results of the present study suggest that serious cognitive deficit may occur in vitamin B(6)-deficient animals.

Degradation of azo dyes using low iron concentration of Fenton and Fenton-like system

This study investigated Fenton and Fenton-like reactions at low iron concentration (<or==10 mg l-1) to oxidize three commercial azo dyes, namely Red MX-5B, Reactive Black 5 and Orange G. In some local cases in Taiwan, wastewater color was found to be the only problem in meeting local effluent standards. This investigation reveals that both of these methods can remove the color of these dyes completely. Moreover they only produce little sludge in wastewater that meet local effluent standards and do not need to further treat. The effects of Fe2+, Fe3+, H2O2 and solution pH on dye decolorization are demonstrated in detail. The optimum pH for both Fenton and Fenton-like reactions in this study are about pH 2.5-3.0. Increasing the dose of ferric nitrate enhances the dye decolorization. The optimal levels of H2O2 required for the process are also examined. High levels of H2O2 appear to reduce dye decolorization. In addition, it is also found that decolorization of azo dyes undergoes a faster reaction rate than mineralization of azo dyes.

Persistent retention of acetic acid is associated with complete tumour necrosis in patients with hepatocellular carcinoma undergoing percutaneous acetic acid injection

BACKGROUND

Ultrasound (US)-guided percutaneous acetic acid injection therapy (PAIT) is effective for patients with hepatocellular carcinoma (HCC). This study aimed to determine the occurrence and predictive value of persistent intra-tumoral retention of acetic acid after PAIT.

METHODS

We prospectively studied 60 (52 M, mean age 68 +/- 10 years) patients with 72 HCC nodules (45 < or = 3 cm) treated with PAIT. The presence of post-treatment persistent retention of acetic acid, defined as a homogeneous and highly hyperechoid mass in US appearance 3 days after completion of the treatment, was correlated with the treatment response.

RESULTS

The mean size of the treated tumour was 2.9 +/- 1.0 cm (range 1.5-5 cm). Thirty (42%) HCC nodules showed complete tumour necrosis demonstrated by contrast-enhanced dynamic CT. Complete response was found in 22 (69%) of 32 nodules showing persistent intra-tumoral retention of acetic acid (P < 0.001). Small (< or = 3 cm) tumour size was also significantly associated with complete tumour necrosis (P = 0.001). There were no significant differences of the injection volume and treatment sessions between those with and without complete tumour necrosis in either small or large (> 3 cm) HCC (P > 0.1). Multivariate logistic regression analysis showed that persistent retention of acetic acid (odds ratio (OR) 10.4, 95% confidence interval (CI) 3.1-34.7; P < 0.001) and tumour size < or = 3 cm (OR 6.8, 95%, CI 1.8-25.8; P = 0.002) were independent factors predicting complete tumour necrosis.

CONCLUSIONS

The presence of persistent retention of acetic acid is associated with a favourable response and may predict complete tumour necrosis after PAIT.

Study on hydrogen production with hysteresis in UASB

This paper uses a 10-l UASB (upflow anaerobic sludge blanket) bench-scale reactor to treat the esterification wastewater of a polyethylene terephthalate manufacturing plant. Two organic loading rates are used to evaluate the effect on H2 production of temperature gradually step-down and step-up in the range of 11-25 degrees C. Experimental results show that H2 production is positively related to temperature. H2 production increases with temperature at the higher organic loading rate (4.5 kg COD m(-3)d(-1)). However, the H2 produced does not go back to its original concentration but rather follows a hysteresis curve. This hysteresis also occurs in the corresponding concentrations of COD, acetate, propionate and butyrate. As in the H2 profiles, these parameter curves return clockwise during the temperature step-up. At the lower organic loading rate (2.2 kg COD m(-3)d(-1)), no obvious hysteresis is observed for H2 curve. The pattern of other parameters, except for the propionate, returns counterclockwise resulting in the hysteresis phenomena.

Treatment of non-biodegradable wastewater by electro-Fenton method

A novel electro-Fenton method, called the Fered-Fenton method, applying H2O2 and electrogenerated ferrous ions for treating organic-containing wastewater was investigated. By combining electrochemical reduction and chemical oxidation, the process can regenerate ferrous ions and remove organic compounds simultaneously in a batch reactor. Because the generation rate of ferrous ions is one of the key parameters in evaluating the oxidation efficiency of the reaction system, the initial current efficiencies (eta(i)) for iron (III) reduction are examined first. It shows that increasing initial ferric ion concentration can achieve high initial current efficiency. In addition, eta(i) decreased (ca. 20-100%) with increasing current density of cathode (ca. 40-199 A/m2). For illustration, the wastewater from chemical (i.e. electroless) nickel plating was treated in this investigation owing to its non-biodegradability and high organic concentration. The average pH, COD and Ni concentrations of this wastewater were about 5.0, 30,000 and 2,000 mg/L, respectively. Experimental results indicate that traditional Fenton method only removed 60% of COD when using 5,000 mg/L of ferrous ions. However, the COD removal efficiency was promoted after the electricity was introduced into the system (i.e. Fered-Fenton method). Moreover, Ni concentration was reduced from 2,080 to 0.3 mg/L, indicating that the removal efficiency was higher than 99.9%.

Reliability of contemporary radiology to measure tumour size of hepatocellular carcinoma in patients undergoing resection: limitations and clinical implications

BACKGROUND

Preoperative radiology has been widely used to detect and measure hepatocellular carcinoma (HCC). However, its accuracy and reliability are unclear. This study aimed to assess the ability of current radiology to measure tumour size in patients undergoing resection.

METHODS

We evaluated 212 HCC patients undergoing curative resection. Tumour size measured in the pathological examination was correlated with that obtained in preoperative ultrasound (US) and contrast-enhanced dynamic computed tomography (CT). Accuracy and association with tumour recurrence were investigated.

RESULTS

The mean size of the tumour was 4.5 +/- 2.6 cm and was accurate in both US and CT in only 6 (3%) patients. Cirrhosis (P = 0.015), absence of tumour stain (P = 0.002) and small (< or = 4 cm) tumour (P < 0.001) were the significant factors associated with size deviation using both US and CT. Ninety-four (44%) patients developed tumour recurrence within 17 +/- 11 months of resection. Recurrence rate was 52%, 52% and 67% in patients with underestimation in US (relative risk [RR]: 2.0, 95% confidence interval [CI]: 1.2-3.4, P = 0.01), CT (RR: 2.1, 95% CI: 1.1-4, P = 0.022) and both modalities (RR: 2.5, 95% CI: 1.4-4.2, P = 0.001), respectively, compared to 30% recurrence in patients with accurate estimation of tumour size.

CONCLUSION

The accuracy of radiology in measuring tumour size was poor, and may lead to inappropriate treatment. The finding that underestimation of tumour size was associated with a higher tumour recurrence rate is consistent with the hypothesis that HCC may recur from pre-existing tumour foci which could not be identified from the current imaging modalities.

Comparison of percutaneous acetic acid injection and percutaneous ethanol injection for hepatocellular carcinoma in cirrhotic patients: a prospective study

BACKGROUND

Ultrasound-guided percutaneous ethanol injection (PEI) and percutaneous acetic acid injection (PAI) are effective in the treatment of hepatocellular carcinoma (HCC). We conducted a prospective study to compare the therapeutic efficacy of both these methods.

METHODS

Sixty-three patients were treated by PAI using 50% acetic acid and 62 by PEI using pure ethanol. There were no significant baseline differences in age, sex, Child-Pugh class, tumour size and number, or other clinico-biochemical parameters between the two groups.

RESULTS

During a follow-up period of 24 +/- 9 (range 6-38) months, 19 (30%) of the PAI group and 21 (34%) of the PEI group died (P = 0.704). The 1- and 3-year survival rates were 84% and 51% for the PAI group and 81% and 46% for the PEI group (P = 0.651). The corresponding tumour recurrence rates were 51% and 74% for the PAI group, and 54% and 64% for the PEI group (P = 0.787). The treatment sessions were 3.9 +/- 1.6 and 6.2 +/- 2.3 for the PAI and PEI groups, respectively, in each treatment cycle (P = 0.008). A multivariate analysis using the Cox regression model revealed that ascites (relative risk (RR) 3.1, 95% confidence interval (CI) 1.5-6.3, P = 0.002), large (>3 cm) or multinodular HCCs (RR 2.4, 95% CI 1.1-5.4, P = 0.04), and development of tumour recurrence (RR 7.0, 95% CI 3.1-16.0, P < 0.001) were independent, poor prognostic factors in both groups.

CONCLUSIONS

PAI and PEI are equally effective in the treatment of HCC. PAI has the advantage of fewer treatment sessions in each treatment course. Careful pretreatment patient selection may improve survival.

Predicting multiple sclerosis at optic neuritis onset

Using multivariate analyses, individual risk of clinically definite multiple sclerosis (CDMS) after monosymptomatic optic neuritis (MON) was quantified in a prospective study with clinical MON onset during 1990-95 in Stockholm, Sweden. During a mean follow-up time of 3.8 years, the presence of MS-like brain magnetic resonance imaging (MRI) lesions and oligoclonal immunoglobulin (Ig) G bands in cerebrospinal fluid (CSF) were strong prognostic markers of CDMS, with relative hazard ratios of 4.68 [95% confidence interval (CI) 2.21-9.91] and 5.39 (95% CI 1.56-18.61), respectively. Age and season of clinical onset were also significant predictors, with relative hazard ratios of 1.76 (95% CI 1.02-3.04) and 2.21 (95% CI 1.13-3.98), respectively. Based on the above two strong predictors, individual probability of CDMS development after MON was calculated in a three-quarter sample drawn from a cohort, with completion of follow-up at three years. The highest probability, 0.66 (95% CI 0.48-0.80), was obtained for individuals presenting with three or more brain MRI lesions and oligoclonal bands in the CSF, and the lowest, 0.09 (95% CI 0.02-0.32), for those not presenting with these traits. Medium values, 0.29 (95% CI 0.13-0.53) and 0.32 (95% CI 0.07-0.73), were obtained for individuals discordant for the presence of brain MRI lesions and oligoclonal bands in the CSF. These predictions were validated in an external one-quarter sample.

Patient characteristics and prescription patterns of atypical antipsychotics among patients with schizophrenia

BACKGROUND

Schizophrenia, one of the leading causes of disability, contributes substantially to the use of medical and mental health services. The treatment of schizophrenia is therefore particularly important to reduce deficits across a large number of neurocognitive domains.

OBJECTIVE

To describe the prescription (e.g. initiation and switching) patterns of atypical antipsychotic agents and examine the extent to which patient sociodemographic and clinical characteristics are associated with the prescription patterns of atypical antipsychotics among patients with schizophrenia.

METHODS

Using unique data sources from the Veterans Health Administration (VA), the study identified 89 107 patients with schizophrenia based on at least one inpatient or more than or equal to two outpatients' ICD-9-CM codes (> or =7 days apart). We defined a prior 6-month (1/1/99 to 6/30/99) and a post 6-month (7/1/99 to 12/31/99) period to describe patterns of initiation and switching of atypical antipsychotics.

RESULTS

Only a small number of patients were on clozapine (1.8%) and quetiapine (1.4%). More patients were prescribed olanzapine (23%) than risperidone (20%) (P < 0.001). Compared with patients who were on risperidone, those who were on olanzapine were younger (P < 0.001), more likely Hispanic (P < 0.001), more likely married (P < 0.05), had more service-connected disability (P < 0.001), had fewer numbers of physical comorbidities (P < 0.001), and a lower body mass index (BMI) (P < 0.05).

CONCLUSION

Olanzapine and risperidone appear to be prescribed to patients with different sociodemographic and clinical characteristics. Future research needs to explore the reasons for those differences.

Nociceptin/orphanin FQ into the rat periaqueductal gray decreases the withdrawal latency to heat and loading, an effect reversed by (Nphe(1))nociceptin(1-13)NH(2)

The present study investigated the effect of intraperiaqueductal grey injection of nociceptin/orphanin FQ (N/OFQ) and an antagonist (Nphe(1))nociceptin(1-13)NH(2) on the hindpaw withdrawal response to thermal and mechanical stimulation in rats. N/OFQ (5 nmol) significantly decreased the nociceptive thresholds in both tests and 1, 5 and 10 nmol of (Nphe(1))nociceptin(1-13)NH(2) significantly reversed this effect in a dose dependent way. Our results demonstrate, that N/OFQ has a nociceptive action, possibly through inhibition of PAG neurons. This effect is blocked by the antagonist (Nphe(1))nociceptin(1-13)NH(2) probably via ORL1 receptors in the periaqueductal grey.

High failure rate using allograft fascia lata in pubovaginal sling surgery for female stress urinary incontinence

OBJECTIVES

To present our unfavorable experiences using allograft fascia lata. Allograft fascia lata is an attractive sling material providing less pain, a shorter operation time, and a reported effectiveness equal to autologous fascia.

METHODS

A total of 18 women (mean age 51.7 years, range 37 to 76) underwent pubovaginal sling surgery for stress urinary incontinence between March 1999 and July 1999 and were enrolled in this study. Solvent dehydrated gamma-irradiated human fascia lata with a size of 7 x 2 cm was used as the sling. The results were collected with a questionnaire survey.

RESULTS

All patients were followed up for a mean of 9.2 months (range 6.9 to 11.6). Thirteen patients considered the surgery successful or to have provided improvement, with a mean of 82.5% (range 50% to 100%) subjective improvement. Five patients (27.8%) had significant failure with full recurrence of incontinence within 3 to 6 months.

CONCLUSIONS

Solvent dehydrated gamma-irradiated allograft fascia is not reliable in pubovaginal sling surgery. The high failure rates within a short period prohibit its use in the operative management of stress urinary incontinence.

Long-term evaluation of recombinant interferon alpha2b in the treatment of patients with hepatitis B e antigen-negative chronic hepatitis B in Taiwan

The effect of interferon (IFN) on hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) has not been fully investigated in Chinese patients. We enrolled 58 HBeAg-negative CHB Chinese patients with hepatitis B viremia in Taiwan to evaluate the response to IFN. 30 patients received recombinant IFN 5 million units 3 times weekly for 6-10 months, and 28 patients who refused IFN treatment served as controls. Rates of virological response and biochemical response were higher in the treated group at the end of treatment (57% vs 18%, P = 0.006, and 73% vs 29%, P = 0.002, respectively). Both effects were superior in the treated group at 6 months after IFN withdrawal (virological: 30% vs 7%, P = 0.06; biochemical: 47% vs 7%, P = 0.002). Improvement of liver histological activities with persistently biochemical response was found in 65% of the treated patients. After a mean of 32 months' follow-up, virological response was rarely maintained (17% vs 4%, P = 0.228) but biochemical response was better in the treated group (27% vs 4%, P = 0.039). None of the treated patients but five controls developed severe complications of CHB during the follow-up period. A larger total IFN dosage or a younger age (< or = 40 years) were associated with 'sustained' virological response. Younger age and higher baseline alanine transaminase values (> or = 120 Ul(-1)) were related to 'sustained' biochemical response.

Hereditary hemorrhagic telangiectasia: demonstration of portosystemic venous shunts using power Doppler sonography and sonographically guided percutaneous transhepatic portovenography

Hereditary hemorrhagic telangiectasia is a rare autosomal dominant inherited disease associated with vascular abnormalities, which may occur in any organ. Cases of hereditary hemorrhagic telangiectasia accompanied by intrahepatic portosystemic venous shunts, however, have rarely been described. We report a case of hereditary hemorrhagic telangiectasia in which intrahepatic portosystemic shunts were detected using power Doppler sonography and portovenography with percutaneous transhepatic contrast agent injection. On gray-scale sonography, the common hepatic artery was dilated, and dilated tubular structures mimicking dilated biliary tracts were found. Power Doppler sonography demonstrated the continuity of tortuous vascular channels connecting a branch of the right portal vein to a branch of the right hepatic vein. The dilated vascular channels and tributaries of the right hepatic vein showed a monophasic waveform pattern on spectral analysis. Portovenography showed a tangle of vascular structures connecting with a branch of the right hepatic vein.

Notch signaling in lymphocyte development

Signaling through Notch has been implicated in many cell-fate decisions during lymphocyte development. Recent studies have provided new clues--and raised new controversies--regarding the exact role that Notch signaling plays in the commitment of cells to the T-cell lineage. Progress has also been made in deducing the transcriptional program induced by Notch and the mechanism of oncogenic transformation by Notch in lymphocytes.

Inhibition of cyclic GMP hydrolysis in human corpus cavernosum smooth muscle cells by vardenafil, a novel, selective phosphodiesterase type 5 inhibitor

One of the key mediators of penile erectile function is nitric oxide (NO), which activates soluble guanylyl cyclase within the smooth muscle of erectile tissue and stimulates the production of cGMP. In addition to synthesis by cyclases, intracellular cGMP concentrations are tightly regulated by phosphodiesterases, which hydrolyze and inactivate cyclic nucleotides. In this study, we compared the inhibition of cGMP hydrolysis by vardenafil and sildenafil; two inhibitors selective for phosphodiesterase type 5 (PDE5). Vardenafil is a novel, high affinity PDE5 inhibitor currently under clinical development. In soluble extracts of human corpus cavernosum smooth muscle cells, vardenafil and sildenafil effectively inhibited cGMP hydrolysis at substrate concentrations of 1, 5 and 10 microM cGMP. The IC50 values for vardenafil were approximately 5-fold lower than for sildenafil at the substrate concentrations tested. Dixon plot analyses of the inhibition data demonstrated that vardenafil had a smaller inhibition constant (Ki = 4.5 nM) than sildenafil (Ki = 14.7 nM) in the same cellular extracts. In intact cells, 10 microM of the nitric oxide donor sodium nitroprusside resulted in a minimal (17%) increase in cGMP, relative to basal levels (321 +/- 65 fmol/mg prot). Treatment of cells with 10, 50 or 100 nM vardenafil, in the presence of 10 microM sodium nitroprusside, elevated cGMP levels in a dose dependent fashion, from 63% to 137% of basal levels. Equimolar concentrations of sildenafil also caused dose dependent increases in intracellular cGMP, but to a lesser extent (27-60%). These observations suggest that vardenafil is a more potent PDE5 inhibitor, than sildenafil in vitro. The more pronounced increase of cGMP in the presence of NO in intact cells suggests that vardenafil will be effective at lower doses than sildenafil under clinical conditions.

Blockade effects of (Nphe1)Nociceptin(1-13)-NH(2) on anti-nociception induced by intrathecal administration of nociceptin in rats

The present study investigated the roles of the opioid-receptor-like (ORL1) receptor and its endogenous ligand nociceptin on nociception in the spinal cord of rats. Intrathecal administration of 10 nmol of nociceptin produced significant increases in hindpaw withdrawal latencies (HWLs) to thermal and mechanical stimulation. There were no significant changes of average maximum angles in inclined plane tests after intrathecal injection of 10 nmol of nociceptin in rats. The intrathecal nociceptin-induced increases in HWL were antagonized by intrathecal administration of (Nphe1)Nociceptin(1-13)-NH(2), a selective antagonist of ORL1 receptor, in a dose-dependent manner. The results demonstrated that ORL1 receptor is involved in the nociceptin-induced anti-nociceptive effect in the spinal cord of rats.

Reduced regional [14C]2-deoxyglucose uptake in response to long-term clozapine administration in rats

Clozapine has superior effects in treating negative symptoms of schizophrenia and causes less extrapyramidal side effects than traditional antipsychotics. In this study, we investigated the effects of acute and long-term clozapine administration on [14C]2-deoxyglucose uptake (2-DG uptake) in rats, as measured using the [14C]2-deoxy-D-glucose method. The 2-DG uptake was reduced in fewer regions after chronic clozapine (46%) than after acute clozapine (97%). After chronic clozapine treatment, the 2-DG uptake was reduced in the shell, but not the core, of the nucleus accumbens. In addition, long-term clozapine treatment remained affecting 2-DG uptake in several regions of the extrapyramidal system and the thalamus. The pattern of 2-DG uptake changes after long-term clozapine administration may provide information for the regions related to the therapeutic effect of clozapine.

Experimental models for the investigation of female sexual function and dysfunction

There have been limited anatomic and physiological investigations of the female sexual arousal response. A broader understanding of the physiologic mechanisms of female sexual arousal function is required to improve the management of women with sexual dysfunction. Three experimental test systems have been developed to understand better the biochemical and physiological mechanisms of female sexual arousal response. An in vivo animal model was developed to record physiological and hemodynamic changes in the clitoris and vagina following pelvic nerve stimulation and administration of vasoactive agents and physiological modulators. In vitro organ baths of clitoral and vaginal tissue were utilized to investigate mechanisms involved in the regulation of smooth muscle contractility. In addition, primary cell cultures of human and animal clitoral and vaginal smooth muscle cells were developed to investigate signal transduction pathways modulating smooth muscle tone. In vivo studies revealed hemodynamic changes in vagina and clitoris in response to pelvic nerve stimulation, vasodilators and physiological modulators. Organ bath studies have demonstrated that clitoral and vaginal smooth muscle tone is affected by non-adrenergic and non-cholinergic neurotransmitters, and the presence of functional alpha 1 and alpha 2 adrenergic receptors in these tissues has been established through biochemical studies. These changes are regulated by the tone of vascular and non-vascular smooth muscle in the vagina and clitoris. Primary cell culture studies have suggested that several physiological modulators such as vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and prostaglandin E (PGE) regulate vaginal smooth muscle contractility. Data from experimental models have provided a preliminary understanding of the mechanisms of the female sexual arousal response.

[Rhein induces apoptosis in cancer cells and shows synergy with mitomycin]

AIM

To study the apoptosis-inducing and growth-inhibitory effect of rhein, an herb-derived compound, and its combination with mitomycin C (MMC) on cultured tumor cells.

METHODS

MTT assays were used to determine the inhibition of proliferation by drugs in several tumor cell lines. Nucleoside transport and DNA synthesis inhibition were determined by [3H] thymidine transport and incorporation assays. Flow cytometry, electrophoresis on agarose gels and morphological assessment were applied to analyze the apoptotic changes.

RESULTS

The IC50 values of nucleoside transport was 19.1 micrograms.mL-1 and that of the DNA synthesis inhibited by rhein was 27.4 micrograms.mL-1. In MTT assay the IC50 values of rhein for KB, hepatoma BEL-7402 and mammary carcinoma MCF-7 cells were 11.5 micrograms.mL-1, 14.0 micrograms.mL-1 and 18.4 micrograms.mL-1 respectively. Synergistic effect of rhein and MMC was found in all the three cell lines. As found, rhein induced apoptosis in KB cells, and the increase of apoptotic cells reached 71.0% at 96 h. The combination of rhein and MMC enhanced the induction of apoptosis significantly.

CONCLUSION

These results suggest that rhein, as a biochemical modulator, might be potentially useful in cancer chemotherapy.

Ranitidine-related Stevens-Johnson syndrome in patients with severe liver diseases: a report of two cases

Ranitidine is widely used and well tolerated. Ranitidine-related skin eruption is rare and usually mild. We presented two patients who developed Stevens-Johnson syndrome after ranitidine therapy. Before therapy, both patients had severe liver disease and jaundice. The first was a case of ketoconazole-induced hepatitis, and the second was a case of hepatitis C-related liver cirrhosis with hepatocellular carcinoma. Ranitidine was the most likely drug responsible for causing Stevens-Johnson syndrome in these two patients.

Heterogenous and homogenous catalytic oxidation by supported gamma-FeOOH in a fluidized-bed reactor: kinetic approach

Oxidation of benzoic acid (BA) by H2O2 was performed with a novel supported gamma-FeOOH catalyst in a circulating fluidized-bed reactor (CFBR). This study focused mainly on determining the proportions of homogeneous catalysis and heterogeneous catalysis in this CFBR. Also studied herein was how pH, H2O2 concentration, and BA concentration affect the oxidation of BA. Experimental results indicate that the decomposition rate of H2O2 was proportional to its concentration and that the oxidation rate of BA depended on both H2O2 and BA concentrations. The change in the rate constant of heterogeneous catalysis by pH was described in terms of ionization fractions of surface hydroxyl group. From the mathematical deduction, we can infer thatthe reaction rate associated with ...Fe(III)OH2+ is markedly higher than that with ...Fe(III)OH. Conclusively, although heterogeneous catalysis contributes primarily to the oxidation of BA at pH 4.4-7.0, the homogeneous catalysis is of increasing importance below pH 4.4 because of the reductive dissolution of gamma-FeOOH.