BACKGROUND: Icaridin and DEET are common insect repellents widely used on human skin and clothing (skin-insect repellents [skin-IR]) to repel common pests, such as mosquitoes and biting flies. Novel analytical methods for urinary skin-IR exposure biomarkers that can be effectively applied in epidemiological studies and provide strong evidence related to risk assessment associated with daily exposure are required. In this study, we aimed to develop a method for analyzing the concentrations of icaridin, DEET, and two DEET metabolites N,N-diethyl-3-(hydroxymethyl) benzamide and 3-(diethylcarbamoyl) benzoic acid in human urine. METHODS: In this analysis, after formic acid-induced acidification of the urine sample, exposure biomarkers were extracted using solid-phase extraction composed of a modified polystyrenedivinylbenzene polymer for reversed phase (hydrophobic) retention. Subsequently, high-performance liquid chromatography-tandem mass spectrometry was performed within 10 min for a separation analysis. The present method was applied to five Japanese adults (aged 20-43 years) who used icaridin or DEET-containing products within a week. RESULTS: Limits of detection were 0.06-0.11 µg/L. Extraction recoveries were 74%-88%. The intraday and interday variations were 1.5-17.5 and 0.9-15.8% relative standard deviation, respectively. All exposure biomarkers were successfully detected in all five adults. Urinary concentrations of exposure biomarkers reached their maximum values within 15 h after starting to use skin-IR. CONCLUSIONS This method was successful in measuring urinary exposure biomarkers of skin-IR, including icaridin and DEET. Moreover, this study presents the first application of biomonitoring of urinary icaridin concentrations after using a commercial product.
Humans ; Solid Phase Extraction/methods* ; Tandem Mass Spectrometry/methods* ; Adult ; Insect Repellents/urine* ; DEET/urine* ; Young Adult ; Male ; Japan ; Female ; Chromatography, Liquid ; Biomarkers/urine* ; Chromatography, High Pressure Liquid ; East Asian People

OBJECTIVE: Peroxisome proliferator-activated receptor delta (PPAR-delta) is an ubiquitously expressed nuclear receptor that has been implicated in adipose tissue formation, brain development, and atherosclerosis. Despite mouse studies demonstrating that PPAR-delta activation has favorable anti-atherogenic properties by improving systemic lipid profiles, the relationship between PPAR-delta agonist and angiogenesis is unknown. We hypothesized that PPAR-delta ligands modulate the angiogenesis. METHODS: To test this hypothesis we treated primary cultures of bovine aortic endothelial cells with PPAR-delta specific ligand, GW501516 (50-800 nM) for 6 h. RESULTS: GW501516 dose-dependently decreased nitric oxide production without alteration in endothelial nitric oxide synthase (eNOS) expression. Analysis with phospho-specific antibodies against eNOS demonstrated that GW501516 significantly decreased the phosphorylation of eNOS at Serine1179 (eNOS-Ser1179). Concurrently, GW501516 also decreased the Akt phosphorylation. GW501516 did not affect endothelial cell proliferation or induce apoptosis. However, GW501516 inhibited endothelial cell migration, and tube formation in a high nanomolar concentration. The inhibition of endothelial cell tube formation by GW501516 was prevented by addition of the nitric oxide donor, DETA NONOate (5 microM). GW501516 was also found to inhibit angiogenesis in vivo in the chicken chorioallantoic membrane assay. CONCLUSION: These results provide that high nanomolar range of GW501516 inhibits angiogenesis by a mechanism involving dephosphorylation of eNOS-Ser1179.
Adipose Tissue ; Animals ; Antibodies, Phospho-Specific ; Apoptosis ; Atherosclerosis ; Brain ; Chickens ; Chorioallantoic Membrane ; DEET ; Endothelial Cells ; Humans ; Ligands ; Mice ; Nitric Oxide ; Nitric Oxide Synthase Type III ; Nitroso Compounds ; Peroxisomes ; Phosphorylation ; PPAR delta ; Thiazoles ; Tissue Donors

BACKGROUND: Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF) are now considered as major health problems in the Philippines. N,N,-dietyl-3-toluamide (DEET) is recognized as the most effective against Aedes aegypti. However, the concern about its use have underscored the need to find a safer alternative repellent.
OBJECTIVES: This study aims to determine and compare the repellent activity of tea tree (Melaleuca alternifolia) oil against Aedes aegypti with 7% DEET using a double-blind controlled experimental trial
METHODOLOGY: Twenty healthy subjects were allocated systematically by alternate assignment into three treatment groups (Control vs. Tea Tree oil, control vs. 7 percent DEET, Tea Tree oil vs DEET). All subjects were exposed to Aedes aegypti for 5 minutes every hour for 8 hours and the number of mosquitoes biting/landing were recorded and compared for each treatment group
RESULTS: Fifty percent tea tree oil has a repellent activity against Aedes aegypti and its efficacy is comparable to 7% DEET. Both treatments were equally effective in repelling mosquitoes for 7 hours. No cutaneous reactions to both repellents were noted
CONCLUSION: The efficacy of tea tree oil is comparable to 7% DEET and is recommended as an alternative natural mosquito repellent.

Human ; Aedes ; Deet ; Dengue ; Healthy Volunteers ; Insect Repellents ; Melaleuca ; Severe Dengue ; Tea ; Tea Tree Oil ; Trees

PURPOSE: The purpose of the present study is to determine the relation between in vitro resistance to 9 drugs, measured with colorimetric methylthiazol tetrazolium(MTT) assay and prognostic factors. METHODS: Thirty children with leukemia were evaluated at the pediatric department of Dongsan Medical Center. All samples tested with the MTT assay contained 80% or more leukemic cells, which were isolated by Ficoll density gradient centrifugation, and were incubated with 9 drugs for 4 days. The optical density(OD) of the wells was measured with microplate spectrophotometer. Leukemic cell survival(LCS) was calculated by OD treated well/OD control wellsx100(%). LD50 was calculated from the dose-response curve and used as a measure of resistance. RESULTS: Among the 30 children with leukemia, 16 were ALL, 14 were AML. Seventeen boys and thirteen girls ranged in age from 9 months to 16 years. Comparing LD50 values according to leukemic type, AML revealed relatively high LD50 values for all drugs, except VCR. But there were no significant differences between ALL and AML(P>0.05). Male showed high LD50 values for ASP, DET, ARA-C, VP16, ADR and 6TG. Age<2 and >10 years children showed high LD50 values for all drugs, except 6TG. Patients with a leukocyte count>100,000/mm3 at diagnosis showed high LD50 values for VCR, ASP, DET, MTX, ARA-C, ADR, and 6TG. Patients with normal chromosome showed higher LD50 values. CONCLUSION: Our study showed higher LD50 values at AML, male, age<2 and 10>years old, leukocyte count>100,000/mm3, and normal karyotype. The MTT test may contribute to the selection of effective chemotherapeutic agent for children with acute leukemia.
Centrifugation, Density Gradient ; Child ; Cytarabine ; DEET ; Diagnosis ; Etoposide ; Female ; Ficoll ; Humans ; Karyotype ; Lethal Dose 50 ; Leukemia ; Leukocytes ; Male ; Viperidae

BACKGROUND/AIMS: The distribut ion of HCV genotypes varies with geographical area, and genot ypes can affect t he nat ur al course of HCV infection, but adequate genot yping data were not accumulat ed in Korea. This study was des igned to det ermine the pattern of distribution of HCV genotypes in Korea and it's clinical implications. METHODS: 100 cons ecut ive anti- HCV( +), RT-PCR(+) cases were recruited. Genotype specific oligonucleotide primers were made according to the sequence variation of NS5 region of HCV genome. Heminested PCR with mixed primersets was per formed, and genotype specific PCR products of different size were verified. Sequencing of cloned PCR products was done in cases with representative genotypes. Clinical profiles of genotype 1b and 2a were compared. RESULTS: Genotyping was done in 78 among 100 cases. Genotype 1b (48/ 78, 57.7%) and 2a (25/ 78, 32.1%) were most prevalent , and 1a (1/ 78, 1.3%) and mixed form (7/ 78, 9.0%) were also found. Milder cases with persistent normal ALT levels were more frequently seen in genotype 2a ( 9/ 25, 36.0%) than in genot ype 1b (3/ 45, 6.7%) (p< 0.01). CONCLUSIONS: Genotype 1b and 2a were major ones in anti- HCV( +) Korean adults, and the tendency of milder clinical course of genotype 2a was suggested.
Adult ; Clone Cells ; DEET ; DNA Primers ; Genome ; Genotype ; Hepacivirus* ; Hepatitis C* ; Hepatitis* ; Humans ; Korea ; Polymerase Chain Reaction*

A 47 year old man gave a history of progressive deterioration of vision in his right eye of more than 8 years duration, which culminated in total blindness. Since 1981 by several ophthalmologists, he had been diagnosed as retinal deta chment, a case of cysticercosis, or choroidal melanoma of the right eye. On admission, ultrasonogram and CT scan for the globe showed choroidal tu mor which entirely filled the vitreous cavity. Cytology for ascites disclosed malignant melanoma cells. Death from metastatic disease occurred four weeks after admission. The diffrentiation between primary and metastatic melanoma may be difficult. The followings are the noted help points: metastatic tumors are typically multiopIe and flat in the uveal tract: multiple tumor emboli are observed in choroid, ciliary body or retinal vessels: associated nevus cells at the base of tumor are lacking: and epitheloid cell types are consistently present. This case might be, morphologically and by his history, originated from a primary choroidal melanoma(epitheloid type).
Ascites ; Blindness ; Choroid* ; Ciliary Body ; Cysticercosis ; DEET ; Humans ; Melanoma* ; Middle Aged ; Neoplasm Metastasis* ; Nevus ; Retinal Vessels ; Retinaldehyde ; Tomography, X-Ray Computed ; Ultrasonography

A 47 year old man gave a history of progressive deterioration of vision in his right eye of more than 8 years duration, which culminated in total blindness. Since 1981 by several ophthalmologists, he had been diagnosed as retinal deta chment, a case of cysticercosis, or choroidal melanoma of the right eye. On admission, ultrasonogram and CT scan for the globe showed choroidal tu mor which entirely filled the vitreous cavity. Cytology for ascites disclosed malignant melanoma cells. Death from metastatic disease occurred four weeks after admission. The diffrentiation between primary and metastatic melanoma may be difficult. The followings are the noted help points: metastatic tumors are typically multiopIe and flat in the uveal tract: multiple tumor emboli are observed in choroid, ciliary body or retinal vessels: associated nevus cells at the base of tumor are lacking: and epitheloid cell types are consistently present. This case might be, morphologically and by his history, originated from a primary choroidal melanoma(epitheloid type).
Ascites ; Blindness ; Choroid* ; Ciliary Body ; Cysticercosis ; DEET ; Humans ; Melanoma* ; Middle Aged ; Neoplasm Metastasis* ; Nevus ; Retinal Vessels ; Retinaldehyde ; Tomography, X-Ray Computed ; Ultrasonography

The normal vascularization of peripheral nervesand the vascular factor in peripheral nerve les ons have regained increasing interest among surgeons. So, several attempts have been made to assess the relative importance of the vasa nervorum and intrinsic longitudinal vascular plexuses of nerve in maintaining the blood supply.of a segment of nerve trunk. The purpose of our experiment was to determine in laboratory animals the maximum extent to which a nerve can be mobilized without impairing its vascular supply so much that nerve function is jeopardized. All our studies were carried out on both sides of the sciatic-tibial nerve of thirty-two rabbit which were anesthetized intraperitoneally with urethane. The experimental procedure differed in three groups, Group I in which the sciatic nerve was mobilized 3 cm in length, Group II was mob lized 7 cm length and Group III was mobilized 10cm long. The tibialis post. muscles of each group were analyzed at intervals ot 1,2,4,6 and 8 weeks after neurolysis. Each muscles were examined grossly and histologically after hematoxylin and eosin staining. Experimental studies showed that a peripheral nerve is a well vascularized structure with a considerable reserve capacity in its microirculation. The intrinsic collateral system is well developeed and experimental deta supported the view that peripheral nerves may be mobilized over a cons derable length with or the only minium interference with their microvascular flow. The results were as follows: 1. The first evidence of histologic change in the muscle fibers was in the sarcolemmal neclei. 2. Localized atrophy of muscle fibers were observed at the six weeks after neurolysis. 3. With increasing length of neurolysis, abnormal finding were developed in early stage. 4. Massive atrophy of muscle fibers were noted in the muscle fibers which neurolysed more 7cm.
Animals, Laboratory ; Atrophy ; DEET ; Eosine Yellowish-(YS) ; Hematoxylin ; Muscles ; Peripheral Nerves ; Sciatic Nerve ; Surgeons ; Urethane ; Vasa Nervorum