Effects Of Various Chemicals Research Articles

Evaluation of the in vitro antimutagenic effect of Doash tea aqueous extracts

Human carcinogens are formed mainly due to the lifestyle and diet that is followed. It is well known that dietary factors play a crucial role in the aetiology of human cancer. The new attractions of drug discovery using natural products remain an important issue in the current herbal medicine research. The present study aimed to evaluate the antimutagenic activity of the water extracts of Doash leaves against several known mutagens, both direct- and indirect-acting, belonging to different chemical classes. These classes are heterocyclic amines (HAs), polycyclic aromatic hydrocarbons and nitrosamines. The antimutagenic activity will be determined in Salmonella/microsomal system (Ames) using strains of Salmonella Typhimurium. Four Salmonella bacterial strains (TA98, TA97, TA100 and TA1530) were used in the present study. Results obtained showed that Doash extract possesses powerful antimutagenic properties, which impair the deleterious effects of various chemicals used in this study. One possible mechanism involved in this protection is the inhibition of the metabolic activation of chemical carcinogens to their reactive metabolites. We also suggest that the health benefits of Doash could be derived from the additive and synergistic combinations of the various phytochemicals present in Doash leaves. Other studies should also be conducted to determine the active components of Doash leaves, including macronutrients, micronutrients and other phytochemicals. Clinical studies should be performed before any claims that Doash consumption offers chemoprotection against cancer can be made.

Cross experimental analysis of microarray gene expression data from volatile organic compounds treated targets

DNA microarrays have revolutionized environmental research by enabling the discovery of genomic markers that reflect the toxic effect of various chemicals and by providing information on the underlying mechanisms. Microarray-based toxicogenomics approaches have become a popular tool to investigate potential risks of exposure to various environmental contaminants at the DNA level. Especially, the analysis of microarray data that are generated under various experimental conditions is critically important for validation of biomarkers and, thus, diagnosis and treatment of environmental targets. Presently, we identified commonly regulated genes whose expression level varied upon exposure to volatile organic compounds (VOCs) by performing cross-experimental analysis of public gene expression datasets using the RankProd algorithm. VOCs are chemical contaminants that often exhibit long-term adverse effects upon chronic exposure. Since VOCs are often used in household items and residential buildings, it is important to understand their effect on human health in a more systematic way. This cross-experiment resulted in a valid set of commonly regulated genes. The functional analysis of these differentially expressed genes (DEGs) generated several significantly over-represented Gene Ontology terms and identified metabolic pathways tightly-associated with cancer development. The functional analysis of identified up-regulated genes (RPL27, RPS6, RPS11, RPS27A, AURKA, FNTA, HSP90AB1) revealed concordance with genes related to various respiratory symptoms such as non-small cell lung cancer. The selected commonly regulated diseaserelated genes were also compared with the DEGs identified in previous analysis performed individually for validation of biomarkers.

Chemical resistance tests on PP-ternary nanocomposite for its application in bioreactor liner fabrication

Continuous usage of bioreactor causes early degradation of most bioreactor liner materials due to the effects of various chemicals, consequently resulting in contamination in the bioprocess. Performance of PP-ternary nanocomposite (PPTN) for its potential application in the fabrication of bioreactor liner material was investigated in this study. The chemical resistance of the composite samples obtained was tested by exposing them to chemicals such as acid, alkaline, water and bacterial solutions, according to ASTM 543-06, and their effects on the composite samples were carefully observed. Specifically, the investigation focused on the changes in the physico-mechanical properties of PPTN following long term of exposure to these chemicals. The results show slight increase in the weight and dimensions of samples in the first few days, followed by constant reading for the period of 4 weeks. The performance in terms of physical properties was in the range of PPTN with 0.61% MWCNT > PPTN 0.45% > PPTN 0.17%. The maximum percentage change in tensile properties, observed in this study, was approximately 10% against PPTN (0.17%), which indicates stable mechanical properties of the composite and invariably suggests that the nanocomposites could serve as a better alternative for bioreactor liner fabrication.

‘Purity as life’: H.J. Heinz, religious sentiment, and the beginning of the industrial diet

Between 1880 and 1930 the application of new technologies not only reshaped the US landscape by introducing large‐scale manufacturing into urban settings, but it also transformed what Americans ate. This transformation to foods made outside of the home created opportunities for adulteration as exemplified by Upton Sinclair's The Jungle. Equally, widely reported toxic effects of various chemicals fed to Harvey Wiley's Poison Squad only heightened the public's and Congress's fear that there was something fundamentally wrong with the foods Americans ate. Using the H.J. Heinz Company as a case study, this article examines how one large industrial food processor built consumer trust based on his belief that religion and good works were essential to his business and crafting pure foods was his moral obligation. As a pioneer in the nascent food industry, Henry Heinz wanted to infuse both his products and his company with purity to differentiate his products and put consumers' fear of industrial foods to rest.

Chemical cleaning of reverse osmosis and nanofiltration membranes fouled by licorice aqueous solutions

The aim of this work was finding optimum cleaning agents and conditions for cleaning reverse osmosis (RO) and nanofiltration (NF) membranes fouled by licorice aqueous solutions. The effect of various chemicals on flux recovery (FR) and resistance removal (RR) of the fouled membranes was investigated. For both membranes the results indicate that a combination of ethylene diamine tetra acetic acid (EDTA), sodium dodecyl sulphate (SDS) and sodium hydroxide may be used as cleaning agents to achieve an optimum cleaning efficiency. Zeta potential and contact angle measurements indicate the changes in charge and hydrophilicity of the surface of RO and NF membranes at various pH solutions, respectively. The effect of surface characteristics is evident in efforts to select the optimal operating conditions. The effect of cleaning condition such as concentration, temperature, pH and cleaning time was studied. The optimum temperature, cleaning time, pH and concentration were found as 35 ± 1 °C, 20 min, 12 and 0.1 wt.%, respectively. SEM pictures showed the surface morphology of RO and NF membrane.

Magnetometric evaluation of toxicities of chemicals to the lungs and cells

Because the lungs are exposed to airborne hazardous materials, alveolar macrophages (AMs) play a major role in defending against the exposure to various noxious chemical substances. In this study, we reviewed magnetometric investigations of the effects of various chemicals on the lungs and AMs. Magnetometry, using magnetite as an indicator, was used to evaluate the effects of certain chemicals on the lung and AMs. A rapid decrease of the remanent magnetic field after the cessation of external magnetization, a phenomenon called relaxation, was impaired when the lungs and macrophages were exposed to toxic substances. The delayed in vivo relaxation observed in the lungs exposed to magnetite and gallium arsenide was almost identical to the in vitro relaxation observed in the AMs exposed to the same materials. Delayed relaxation was observed in the AMs exposed to silica dust; various fibers, such as chrysotile and some man-made mineral fibers; and toxic arsenic and cadmium compounds. The extracellular release of lactate dehydrogenase activity was found in the AMs exposed to the chemicals. Relaxation is attributed to the cytoskeleton-driven rotation of phagosomes containing magnetite. While the exact mechanism of delayed relaxation due to exposure to harmful chemicals remains to be clarified, cell magnetometry appears to be useful for the safety screening of chemical substances.

Evaluation of the effects of various chemicals on discharge of and pain caused by jellyfish nematocysts

Jellyfish tentacles in contact with human skin can produce pain swelling and redness. The pain is due to discharge of jellyfish nematocysts and associated toxins and discharge can be caused by a variety of mechanical and chemical stimuli. A series of tests were carried out with chemicals traditionally used to treat jellyfish stings e.g. acetic acid ammonia meat tenderizer baking soda and urea to determine if these chemicals stimulated or inhibited nematocyst discharge and if they brought relief to testers who were exposed to jellyfish tentacles. Chrysaora quinquecirrha (sea nettle) Chiropsalmus quadrumanus (sea wasp) and Physalia physalis (Portuguese man-of-war) were used in the study. It was found that many of the chemicals traditionally used to treat jellyfish stings stimulated nematocyst discharge and did not relieve the pain. However there was immediate relief when a common anesthetic lidocaine was sprayed on the skin of testers in contact with jellyfish tentacles. Initial exposure of tentacle suspensions to lidocaine prevented the nematocyst discharge by subsequent exposure to acetic acid ethanol ammonia or bromelain. Thus lidocaine in addition to acting as an anesthetic on skin in contact with jellyfish tentacles inhibited nematocyst discharge possibly by blocking sodium and/or calcium channels of the nematocytes.

INFLUENCE OF SEED TREATMENT ON THE ENHANCEMENT OF GERMINATION AND SEEDLING VIGOUR OF PAPAYA

Papaya is mainly propagated through seeds. The seeds are covered with sarcotesta, a whitish succulent and translucent material which has been reported to delay germination. The freshly extracted seeds exhibit dormancy when sown immediately and the dormancy can be broken by after-ripening by storage for a short period, but prolonged storage also results in poor germinability. Treatment of seeds with growth regulators and certain chemicals has been found to break dormancy and improve the germination. Hence an experiment was conducted in order to study the effect of various chemicals on seed germination and seedling growth of papaya. The experiment was carried out in completely randomized design with fifteen treatments in three replications. The treatments included soaking the seeds in GA 3 (50, 100 and 200 ppm), NAA (100 and 200 ppm) and thiourea (1000, 2000 ppm) for 6 and 12 h duration along with a control. The results revealed that seeds soaked in GA 3 200 ppm for 12 h reduced the time taken for 50% germination, increased root and shoot length and vigour index followed by seed treatment with thiourea 2000 ppm for 12 h. The least values were recorded in the control.

Effect of chemotherapy, vaccines and immunostimulants on innate immunity of goldfish infected with Aeromonas hydrophila

We report the effect of various chemicals, vaccines and immunostimulants on innate immune mechanisms such as phagocytosis activity, superoxide anion production of blood leukocytes, complement activity and plasma lysozyme activity and disease resistance in goldfish Carassius auratus (23 +/- 2 g) against Aeromonas hydrophila on Days 15 and 30 post-infection. In infected fish, the administration of diets supplemented with either probiotics, tri-herbal extract or azadirachtin for 30 d significantly enhanced phagocytic activity; administration for 15 d had no effect. In fish treated with heat-killed and formalin-killed vaccines, and probiotics-, tri-herbal- and azadirachtin-supplemented diets, superoxide anion production was enhanced on Day 30. However, there was no superoxide anion production in fish treated with tetracycline, furanace, formalin or hydrogen peroxide. Complement activity was also significantly enhanced on Days 15 and 30 in fish groups treated with vaccine and probiotics-, tri-herbal- and azadirachtin-supplemented diets. Other groups had no complement activity. Lysozyme activity was significantly enhanced after 30 d in fish treated with heat-killed vaccine and probiotics-, tri-herbal- and azadirachtin-supplemented diets. The probiotics- and tri-herbal-containing diet administration groups had no mortality (0%) preceding the challenge with live A. hydrophila. Groups treated with heat- or formalin-killed vaccines or azadirachtin-supplemented diet suffered mortalities of 30, 35 and 10%, respectively, which represents an improvement of survival rate compared to untreated infected control groups. We conclude that probiotics-, tri-herbal- and azadirachtin-supplemented diets act as immunostimulants enhancing the goldfish innate immune response and disease resistance against A. hydrophila.

Effect of Various Chemicals as Solvents on the Dissolution of Set White Mineral Trioxide Aggregate: An In Vitro Study

Introduction The main disadvantages of mineral trioxide aggregate (MTA) are its prolonged setting time and the difficulty in retrieving it from the root canal. Because MTA is alkaline in nature, it might interact with acids or chemicals and could disintegrate. The aim of this study was to assess the effect of various chemicals on dissolution of white MTA (WMTA). Methods Stainless steel molds were prepared and filled with WMTA that was exposed to carbonic acid, 2% chlorhexidine gluconate solution, 17% ethylenediaminetetraacetic acid (EDTA) solution, and saline on days 1 and 21. The surface hardness was measured before and after 5-, 10-, 15-, and 20-minute intervals after exposure to chemicals. The samples were probed with a #16 endodontic explorer after 20 minutes of chemical exposure and hardness testing. Results Both qualitative and quantitative analysis showed that carbonic acid was effective in significantly reducing the surface hardness of set WMTA on both days 1 and 21; 2% chlorhexidine gluconate reduced the surface hardness of set WMTA significantly on day 1 only. Conclusions Carbonic acid can be effectively used as an adjunct to dissolve set WMTA even after 21 days, whereas 2% chlorhexidine gluconate showed significant surface dissolution only within 24 hours of WMTA placement. Thus, usage of chlorhexidine gluconate as a root canal irrigant in which WMTA is used during endodontic procedure should be avoided for 24 hours. Solutions with EDTA have no effect on surface hardness of WMTA.

Filterable forms of Nocardia: a preferential site of infection in the mouse brain

Filterable forms of Nocardia (i.e., filterable nocardiae) are characterized as spherical structures containing many granules. They fluoresce brilliantly under ultraviolet light when stained with acridine orange and are acid-fast in paraffin-containing broth cultures. An accumulation of acid-fast lipochrome bodies, similar to filterable nocardiae, is observed in glial cells of the midbrain nigral lesions found in Parkinson's disease (PD). Preliminary results from experimental infection with filterable nocardiae revealed a possible site of infection in a region of the nervous system associated with movement disorders. Here we examined the preferential site of filterable nocardiae infection in the brain and investigated the effects of various chemicals and biological substances in relation to this preferential site on nocardiae growth in vitro. Examination of tissue samples immunostained for filterable nocardiae revealed that neurons in the olfactory bulbus and the midbrain periaqueductal gray area were immunopositive for filterable nocardiae. Several erythrocytes within blood vessels of the brain were also immunopositive. In addition, a dose-dependent relationship was observed between the growth of filterable nocardiae and erythrocyte lysates. These results suggest first that the preferential site of infection for filterable nocardiae might be erythrocytes, but could also be neurons in the bulbus olfactorius as well as in the midbrain periaqueductal gray area. Second, filterable nocardiae might grow to be branching cylindrical tubules such as that of mycelial bacteria in the presence of erythrocyte lysates.

Spectrometric studies on the cloud points of Triton X-405

The effect of various chemicals on the cloud point (CP) of nonionic surfactant Triton X-405 (TX-405) in aqueous solutions has been investigated. In the measurements of cloud point temperatures, UV–visible spectrophotometer was used instead of visual observation. The values of CP for Triton X-405 could not be measured directly because TX-405 had an average number of oxyethylene units per molecule, p ≈ 35 and a CP > 100 °C. To avoid additional measurements under pressure, TX-405 had their CP lowered below the normal boiling point of their solutions by adding the salting-out, CP-lowering salts at various concentrations, measuring the depressed CP values and extrapolating them to zero salt concentration. The CP values decrease linearly with increasing concentration of salts at studied concentrations. The results showed that the addition of the simple salts and nonionic surfactant Triton X-114 (TX-114) which are infinitely miscible with water decreased the cloud point of the TX-405. In this study, the real CP values of TX-405 which are merely listed as >100 °C in the literature was found as 116 ± 1 °C in various samples. In the lyotropic series, it is expected that the effect of F − > Cl − > Br − will be on the decrease in CP, because the ionic sizes increase along the group consequently decreasing the formal charge density on anion, thus lowering the attraction on anion and thereby lowering the attraction of water. The order of CP depression for the other anions is as follows: PO 4 3− > SO 4 2− > NO 3 − > Br −. This means that electrolyte containing trivalent anions is more effective at salting-out the PEO chain than those containing divalent anions and monovalent anions. Cations effectiveness is present in the following order for change: Na + > K + > NH 4 + because of their effect on water structure and their hydrophilicity. Overall the electrolytes and nonelectrolytes have a large amount of effect on CP of nonionic surfactant, because of their effect on water structure and their hydrophilicity.

Adverse Birth Outcomes of Maternal Smoking During Pregnancy and Genetic Polymorphisms: Exploiting Gene-Environment Interaction

It has been recognized that metabolic enzymes mediating genetic susceptibility to environmental chemicals such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls might be related to adverse human health. Recent studies, including the Hokkaido Study of Environmental and Children's Health, have shown that metabolic enzymes mediating genetic susceptibility to environmental chemicals including tobacco smoke might be related to adverse birth outcomes. Certain maternal genetic polymorphisms in the polycyclic aromatic hydrocarbons (PAHs)-metabolizing enzymes have been shown to enhance the association between maternal smoking and infant birth weight in both Caucasians and Japanese. For maternal genetic polymorphisms encoding the N-nitrosamine-metabolizing enzymes, we found that infant birth weight, birth length and birth head circumference were significantly smaller among infants of smokers than among those of nonsmokers and quitters. The adverse effects of maternal smoking on infant birth size may be modified by maternal genetic polymorphisms. Further study is required to clarify the potential association between genetic polymorphisms and cognitive function in childhood, becauae it has been reported that a small birth length or a small head circumference at birth might affect neurobehavioral development during early childhood. It is necessary to elucidate additive impacts of genetic factors on adverse effects of various chemicals commonly encountered in our daily lives, follow up the development of children, and carry out longitudinal observation.

Approaches and constraints of using existing landrace and extant plant material to understand agricultural spread in prehistory

The potential for the phylogeographical analysis of cereal landraces to determine the initial patterns of agricultural spread through Europe is discussed in relation to two of the first cereals to be domesticated, emmer wheat (Triticum turgidumsubsp.dicoccum) and barley (Hordeum vulgare). Extant landraces available from germplasm collections have a patchy distribution, largely being confined to regions of rugged upland topography, and the phylogeographical patterns observed may be due to ‘overstamping’ by more recent crop movements. Phylogeographical studies of non-viable historical landrace material held in herbarium and old seed collections and found in historical buildings have the potential to fill in the gaps in time and space. We explore the importance of precise geographical provenance and the limitations of this in extant and historical material. Additionally, we consider the effect of various chemicals and the preservation of DNA in the historical material.

Completely automated short-term genotoxicity testing for the assessment of chemicals and characterisation of contaminated soils and waste waters

The umu-test was developed for the detection of effects of chemical mutagens and carcinogens in environmental samples. It is performed according to ISO 13829 with Salmonella choleraesius subsp. chol. (strain TA1535/pSK1002). By automating the entire test, large numbers of toxicants and environmental samples as well as more treatments and parallels can be tested and, additionally, only low sample volumes are needed. In this work, an automated umu-test has been set up by installing a robotic XYZ-platform and a microplate reader inside a cabin. The use of established technical equipment for the automation in combination with a performance according to ISO standards was the essential aim of the approach. After initial preparation, the test is conducted software-controlled, follows the standard and fulfils the validity criteria of the standard procedure. For the optimization of the automated test umu-tests with one concentration of methyl methanesulfonate (MMS) of 166.7 mg/L were carried out. After optimization of incubation and pipetting conditions in the automated test, dose-response curves of various chemicals and environmental samples were assessed. The results of the automated umu-test have been compared with those of the standard manual test. The aim of the study was to show the applicability of an automated test system for the assessment of the genotoxic effects of various chemicals and environmental samples. During optimization, tests with 166.7 mg/L of MMS in every well of the microplate are carried out. Chemicals with different physical, chemical and toxicological properties are applied in both test systems. Water samples from different waste water treatment plants, and water extracts of contaminated and uncontaminated soils are assessed in the umu-test. The test is performed in parallel manually according to the standard and automatically using the robotic platform. Dose-response relationships and DLI-values are recorded and compared. The umu-test is applied on a RoboSeq 4204 SE pipetting station (MWG AG, Ebersberg, Germany). The robot is equipped with four holders for disposable tips to avoid undesired mixing of liquids while testing. With this system, it is possible to pipette all liquids. Photometric measurements are performed using a microplate reader. The pipetting station and the photometer are placed in an incubation cabin. According to the standards, exposure and growth of the bacteria are performed at 37 degrees C and the enzyme activity is assessed at 28 degrees C. Since both temperatures can't be adjusted simultaneously in the cabin, the test is performed in deviation from the standard at 33 degrees C. The results show that both the testing of non-volatile substances with strong or moderate genotoxic effects and the testing of water and soil samples in the automatic system work very well. Nevertheless, it is still difficult to characterize volatile chemicals automatically. This is illustrated, e.g. by testing 2- +/- -hydroxyquinoline. In this case, the chemical would not be assessed genotoxically after automatic performance of the umu-test. Sealing of the microplates, for example, avoids the loss of volatile substances, but this step of the procedure can not be performed automatically. Discussion. Only very few studies deal with the automation of bioassays. Eisentraeger et al. (2004) showed the suitability of a miniaturized and automated algae test for the testing of large numbers of environmental samples. Genotoxicity with an automated liquid handling are introduced by White et al. (1996) and Janz et al. (1989). A complete automation including liquid handling, incubation and photometric measurement is a new approach and leads to satisfying results. Optimization and suitability of the automated test are demonstrated in this study. Induction rates and growth factors do not differ significantly if the incubation temperature and the pipetting mode are optimized. Due to flexible scripting, the newly developed automated test system can also be used to perform other genotoxicity tests. Most results clearly show that genotoxicity tests can be automated completely allowing rapid testing that can be performed over night, for instance. Nevertheless, the test performance has to be optimized step by step depending on the technical characteristics of the automat. In order to overcome these technical problems, detailed knowledge of the hardware and the software of the automat and of the respective genotoxicity test system are needed. During this process of automation, it is very useful to test one genotoxic substance with an identical concentration in every well. The automated test system based on the RoboSeq 4204 SE pipetting station (MWG AG, Ebersberg, Germany) still has to be optimized with respect to the testing of volatile compounds. There is a need for removable, gas-tight microplate covers. For non-volatile chemicals and environmental samples, it can be used routinely. Nevertheless, the experiences made during this study can only partly be transferred to other robotic platforms and other bioassays, and automation of bioassays still can be a time-consuming matter.

Drug Assessment Based on Detection of l-Glutamate Released from C6 Glioma Cells Using an Enzyme−Luminescence Method

Monitoring of excitation activity of nerve cells is very useful for not only brain research but also assessment of the effects of various chemicals, including drugs and toxins. We previously reported a novel enzyme-luminescence method for real-time monitoring of l-glutamate release from C6 glioma cells with high levels of sensitivity ( approximately 10 nM) and temporal resolution (<1 s) using a luminescence plate reader. In the present study, we tested the applicability of this novel system for assessment of effects of drugs in vitro. Several drugs (e.g., veratridine and 4-aminopyridine) were administered to C6 glioma cells for inducing glutamate release. Moreover, antagonists of voltage-dependent Ca (2+) channels (e.g., nifedipine, flunarizine, and NiCl 2) and Na (+) channels (e.g., carbamazepine and lidocaine) were applied separately for evaluating the effects of these chemicals on glutamate release from the cells. The combined effect of carbamazepine and lidocaine was also investigated by using our method, and the combined effect was found to be more potent than that of single drug administration. These results indicated that the glutamate release from C6 cells was modulated by these drugs in a way similar to that found by using several conventional analytical techniques. We therefore conclude that the developed monitoring system for real-time detection of dynamic l-glutamate release from cells could be very useful for application to assessment of drugs acting on the nervous system.

Progesterone Receptors in the Developing Genital Tubercle: Implications for the Endocrine Disruptor Hypothesis as the Etiology of Hypospadias

In fetal mice genital tubercles the ontogenetic expression of progesterone receptors and the effect of in utero estrogen and testosterone exposure were investigated. To evaluate ontogenetic progesterone receptor expression genital tubercles from untreated fetuses at gestational days 12, 14, 16 and 18, and newborn pups were prepared for real-time reverse transcriptase-polymerase chain reaction or immunohistochemistry. To evaluate estrogen and testosterone effects pregnant dams were gavaged once daily with corn oil (vehicle), ethinyl estradiol or testosterone propionate from gestational days 12 through 17. At gestational day 19 the genital tubercles of delivered fetuses were harvested for morphological examination and then pooled for real-time reverse transcriptase-polymerase chain reaction. Progesterone receptor protein was first detected at gestational day 12 in the urethral plate and mesenchyma. At later stages staining intensity increased with a greater progesterone receptor signal, especially in the urethra. Progesterone receptor mRNA expression showed different increasing patterns in each sex until birth. However, no difference was noted between male and female genital tubercles in terms of the distribution and quantity of progesterone receptor expression. In utero ethinyl estradiol led to 8.2, 9.7 and 5.2-fold increases in progesterone receptor mRNA in females and in males with and without hypospadias, respectively. Testosterone propionate significantly decreased progesterone receptor mRNA levels in females and males. Progesterone receptors are expressed in developing genital tubercles, suggesting a direct role of progesterone in normal genital tubercle patterning. Their increasing expression until birth also implies increasing sensitivity of the genital tubercles to the effects of estrogenic and progestogenic endocrine disruptors during fetal life. Ethinyl estradiol and testosterone propionate lead to opposing effects on progesterone receptor expression, in addition to their opposing morphological effects on the genital tubercles. These findings expand our knowledge of genital tubercle morphogenesis and provide important information for understanding the effects of endocrine disruptors.

Relationship between Cell Morphology and Intracellular Potassium Concentration in Candida albicans

Previously we reported that valinomycin inhibited hyphal growth and induced growth as a chain of yeast cells under hyphal growth induction conditions in Candida albicans. To elucidate the hyphal growth inhibition by valinomycin, we examined the effect of various chemicals on the morphology and found that miconazole inhibited hyphal growth as well as valinomycin: both compounds promoted the leakage of potassium from cells. Analysis of intracellular potassium suggested that hyphal cells contain potassium at high concentrations in comparison with yeast cells. Hyphal growth inhibition by valinomycin was obstructed by the addition of serum. Potassium measurement showed that the addition of serum causes an increase in intracellular potassium, suggesting that the obstruction by serum might be due to an increase in intracellular potassium. The above-mentioned results strongly suggest that the addition of valinomycin and miconazole decreased interacellular potassium and this decrease inhibited hyphal transition.

Effects of Solvents on Skin Permeation of Formoterol Fumarate

Effects of various chemicals applied as penetration enhancers on the permeation of formoterol fumarate (FF) across excised rat skin were investigated. Remarkable enhancement was noted with terpenes, fatty acid esters, and higher alcohols, whereas no significant influence was observed in the case of lower alcohols, pyrrolidones, and amines. At high concentration, a cineole/N-methyl-2-pyrrolidone (NMP) mixed solvent system slightly enhanced the skin permeation of FF compared with cineole alone, and a l-menthol/NMP mixed solvent system caused significant further increase. Maximum skin permeation of FF was seen when the ratio of l-menthol/NMP was 60/40 w/w. From the present results, l-menthol/NMP and isopropyl myristate (IPM)/NMP mixed solvent systems can be considered effective for augmenting skin permeation of FF, with potential applications in transdermal delivery of the drug.

Treatment with hydroxyurea and tyrphostin-1 significantly improves the transduction efficiency of recombinant adeno-associated viruses in human cancer cells

To enhance the transduction efficiency (TE) of a recombinant adeno-associated virus 2 (rAAV2) in human cancer cells, we examined the combined effects of various chemicals known to influence the rAAV2 transduction process at distinct steps. Among the agents tested were trichostatin A, a histone deacetylase inhibitor, MG-132, a proteosome inhibitor, the genotoxic agents hydroxyurea, aphidicolin, etoposide and camptothecin, and tyrphostin-1, an epidermal growth factor receptor inhibitor. During or after chemical treatment, various human cancer cells were infected with rAAV2 expressing beta-galactosidase. Treatment with hydroxy-urea or etoposide plus tyrphostin-1 dramatically increased the TE in most cell lines. The combination of hydroxyurea plus tyrphostin-1 increased TE to 37.7+/-7.9%, 32.8+/-2.0% and 31.8+/-2.1% in SK-Hep1, HeLa, and HCT116 cells, respectively. In addition, following rAAV2 infection and treatment with hydroxyurea plus tyrphostin-1, long-term transgene expression was observed for up to 6 months, with no damage to the transduced cells. These results indicate that rAAV2 transgene expression can be significantly enhanced by a combination of chemical agents with distinct activity and prolonged gene expression can occur following rAAV2 gene transfer into human cancer cells.