RESUMO
BACKGROUND: Several studies have previously reported that laparoscopic surgery using an energy sealing device generates hazardous surgical smoke. However, the droplets appearing on the surface of peritoneal fluid irrigated with saline, after dissection phase of laparoscopic gastrectomy were ignored for a long time. This study aimed to investigate the composition and clinical significance of these droplet particles. METHODS: This study prospectively enrolled 15 patients with early gastric cancer (cT1NanyM0) who were scheduled for laparoscopic gastrectomy. Floating phases of peritoneal irrigation fluid containing droplets in dissected area were retrieved before and after surgical dissection. Using gas chromatography analysis, the areas under the peak were compared between the samples retrieved before and after surgical dissection. We also analyzed if the area value with significant change was related to the inflammatory response. RESULTS: In gas chromatography, the area values after laparoscopic surgical dissection were significantly increased in 10 out of 37 kinds of fatty acids, compared to those before surgical dissection. The significant increase in area value of α-linoleic and eicosadienoic acids were positively correlated with the elevated level of C-reactive protein at postoperative day 2 (Spearman's ρ = 0.843, P < 0.001; Spearman's ρ = 0.785, P = 0.001). CONCLUSIONS: The lipid droplets, generated after laparoscopic lymphadenectomy during gastric cancer surgery, contained various types of fatty acids, and some of them have been found to be associated with inflammatory response.
Assuntos
Laparoscopia , Neoplasias Gástricas , Líquido Ascítico/metabolismo , Ácidos Graxos , Gastrectomia/métodos , Humanos , Laparoscopia/métodos , Gotículas Lipídicas/metabolismo , Excisão de Linfonodo/métodos , Estudos Retrospectivos , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/cirurgiaRESUMO
OBJECTIVE: Extracts from the brown algae Sargassum micracanthum have documented anti-viral, anti-oxidant, and anti-inflammatory activities as well as potential anti-tumor efficacy against several cancer types. Here, we evaluated the inhibitory effect and molecular mechanisms of methanol extract of S. micracanthum (MESM) on the aggressiveness of human head and neck squamous cell carcinoma (HNSCC) using in vitro cell culture-based models. DESIGN: To test the potential efficacy of MESM on the migratory and invasive properties of HNSCC cells, we used wound healing, transwell cell migration and invasion assays. Proteome profiling and functional in silico analysis were applied to investigate the possible modes of action by MESM. We also examined the metabolite profiling of MESM using gas chromatography/mass spectrometry. RESULTS: MESM inhibited the motility of human HNSCC cell lines as well as invasiveness without influencing cell survival. Proteome profiling identified 19 oncogenic proteins significantly downregulated by MESM treatment. Protein-protein interaction network and gene ontology analyses revealed that Tie2 and associated angiogenic signaling pathway components were significantly enriched among these downregulated oncogenic proteins, which was confirmed by validating the reduced Tie2 expression in MESM treatment groups. Metabolite profiling of MESM identified six-carbon sugar alcohols such as D-sorbitol and/or D-mannitol as the main bioactive compounds. D-sorbitol and D-mannitol effectively reduced Tie2 expression and the aggressiveness of human HNSCC cell lines. CONCLUSIONS: These findings suggest that six-carbon sugar alcohols in MESM have promising anti-cancer efficacy for the treatment of human HNSCC and further identify Tie2 signaling components as potential treatment targets.
Assuntos
Neoplasias de Cabeça e Pescoço , Sargassum , Linhagem Celular Tumoral , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , Metanol , Extratos Vegetais/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genéticaRESUMO
In a previous study, we demonstrated the anti-inflammatory activity of the essential oil extracted from Korean pine (Pinus koraiensis, Sieb. et Zucc.) wood. This study aims to investigate the active anti-inflammatory constituents of P. koraiensis oil. The essential oil was extracted from P. koraiensis wood by hydrodistillation and was divided into six fractions (A-F) through fractional distillation. Then, the anti-inflammatory activities of the fractions (A-F) were determined. Fractions A and F markedly downregulated the production of pro-inflammatory cytokines as well as the secretion of ß-hexosaminidase in lipopolysaccharide (LPS)-stimulated RBL-2H3 cells. The main constituents of the active anti-inflammatory A and F fractions were (+)-α-pinene, (-)-ß-pinene, (+)-α-terpineol, 3-carene, (+)-limonene, and longifolene. These six single compounds decreased the expression of inflammatory-related genes (i.e., IL-4 and IL-13) as well as the secretion of ß-hexosaminidase in LPS-stimulated RBL-2H3 cells. (+)-α-Pinene, (-)-ß-pinene, (+)-α-terpineol, and longifolene exhibited the strongest effects; these effects were comparable to those of the positive control (i.e., dexamethasone). The findings indicate that the interactions between these components exhibit potential for the management and/or treatment of inflammatory conditions as well as base structures for the development of novel anti-inflammatory drugs.
Assuntos
Anti-Inflamatórios , Lipopolissacarídeos/toxicidade , Óleos Voláteis , Pinus/química , Madeira/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Óleos Voláteis/química , Óleos Voláteis/farmacologia , RatosRESUMO
Abeliophyllum distichum (Oleaceae), which is the only species in the monotypic genus and is grown only on the Korean peninsula, has a high scarcity value. Its five variants (white, pink, round, blue, and ivory) have different morphological characteristics in terms of the color of petals and sepals or shape of the fruits. Despite its high value, there has been no study on variant classification except in terms of their morphological characteristics. Thus, we performed a volatile component analysis of A. distichum flowers and multivariate data analyses to reveal the relationship between fragments emitted from five variants of A. distichum flowers with their morphological characteristics. As a result, 66 volatile components of this plant were identified by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS), showing unique patterns for each set of morphological characteristics, especially the color of the petals. These results suggest that morphological characteristics of each variant are related to the volatile composition.
RESUMO
Cholesterol and squalene are fatty materials of latent fingermarks that can be utilized for dating methodologies and visualization techniques. Previous studies have suggested these compounds undergo degradation in fingermarks as a function of time (days) and light at ambient temperature. However, studies assessing how their composition changes at low and high temperatures over short periods of time (hours) have not been published previously. Here, we performed quantitative analysis of cholesterol and squalene in natural fingermark residue using PVDF membrane, after exposure to a range of temperatures (-20 to 100°C) for 4 and 8 h. We found that levels of both fatty materials remained constant at -20 to 60°C, but both showed significant reduction at 100°C, over short exposure times. These results indicate that cholesterol and squalene are detectable at -20 to 60°C, whereas at 100°C or higher, both are lost due to rapid thermal degradation.
RESUMO
In this study, we isolated and identified an aggregation-sex pheromone from Monochamus saltuarius, the major insect vector of the pine wood nematode in Korea. Adult males of M. saltuarius produce 2-undecyloxy-1-ethanol, which is known as an aggregation-sex pheromone in other Monochamus species. We performed field experiments to determine the attractiveness of the pheromone and other synergists. More M. saltuarius adult beetles were attracted to traps baited with the pheromone than to unbaited traps. Ethanol and (-)-α-pinene interacted synergistically with the pheromone. Traps baited with the pheromone + (-)-α-pinene +ethanol were more attractive to M. saltuarius adults than traps baited with the pheromone, (-)-α-pinene, or ethanol alone. Ipsenol, ipsdienol, and limonene were also identified as synergists of the aggregation-sex pheromone for M. saltuarius adults. In field experiments, the proportion of females was much higher in the beetles caught in traps than among the beetles emerging from naturally-infested logs in the laboratory. Our results suggest that a combination of aggregation-sex pheromone and synergists could be very effective for monitoring and managing M. saltuarius.
Assuntos
Besouros/fisiologia , Etanol/análogos & derivados , Éteres/metabolismo , Controle de Insetos/métodos , Pinus/parasitologia , Doenças das Plantas/parasitologia , Atrativos Sexuais/metabolismo , Tylenchida/fisiologia , Animais , Comportamento Animal , Monoterpenos Bicíclicos , Besouros/química , Etanol/análise , Etanol/metabolismo , Éteres/análise , Feminino , Insetos Vetores/química , Insetos Vetores/fisiologia , Masculino , Monoterpenos/metabolismo , Atrativos Sexuais/análiseRESUMO
We evaluated the repellent activity of 12 Apiaceae plant essential oils and their components against male and female adult German cockroaches, Blattella germanica L., to find new natural repellents. Of all the plant essential oils tested, ajowan (Trachyspermum ammi Sprague) and dill (Anethum graveolens L.) essential oils showed the most potent repellent activity against male and female adult German cockroaches. Repellent activities of chemicals already identified in active oils were also investigated. Of the compounds identified, carvacrol, thymol, and R-(-)-carvone showed >80% repellent activity against male and female adult German cockroaches at 2.5 µg/cm2. S-(+)-Carvone, (+)-dihydrocarvone, and terpinen-4-ol showed >70% repellent activity against male and female adult German cockroaches at 10 µg/cm2. Our results indicated that Apiaceae plant essential oils and their constituents have good potential as natural repellents against adult German cockroaches.
Assuntos
Apiaceae/química , Blattellidae/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Animais , Repelentes de Insetos/análise , Repelentes de Insetos/química , Óleos Voláteis/análise , Óleos Voláteis/química , Óleos de Plantas/análise , Óleos de Plantas/químicaRESUMO
This study was carried out to better understand the characteristic modification mechanisms of monolignols by enzyme system of Abortiporus biennis and to induce the degradation of monolignols. Degradation and polymerization of monolignols were simultaneously induced by A. biennis. Whole cells of A. biennis degraded coniferyl alcohol to vanillin and coniferyl aldehyde, and degraded sinapyl alcohol to 2,6-dimethoxybenzene- 1,4-diol, with the production of dimers. The molecular weight of monolignols treated with A. biennis increased drastically. The activities of lignin degrading enzymes were monitored for 24 h to determine whether there was any correlation between monolignol biomodification and ligninolytic enzymes. We concluded that complex enzyme systems were involved in the degradation and polymerization of monolignols. To degrade monolignols, ascorbic acid was added to the culture medium as a reducing agent. In the presence of ascorbic acid, the molecular weight was less increased in the case of coniferyl alcohol, while that of sinapyl alcohol was similar to that of the control. Furthermore, the addition of ascorbic acid led to the production of various degraded compounds: syringaldehyde and acid compounds. Accordingly, these results demonstrated that ascorbic acid prevented the rapid polymerization of monolignols, thus stabilizing radicals generated by enzymes of A. biennis. Thereafter, A. biennis catalyzed the oxidation of stable monolignols. As a result, ascorbic acid facilitated predominantly monolignols degradation by A. biennis through the stabilization of radicals. These findings showed outstanding ability of A. biennis to modify the lignin compounds rapidly and usefully.
Assuntos
Basidiomycota/efeitos dos fármacos , Basidiomycota/metabolismo , Lignina/metabolismo , Substâncias Redutoras/farmacologia , Acroleína/análogos & derivados , Acroleína/metabolismo , Ácido Ascórbico/farmacologia , Basidiomycota/enzimologia , Benzaldeídos/metabolismo , Meios de Cultura/química , Lignina/química , Estrutura Molecular , Peso Molecular , Fenóis/metabolismo , Fenilpropionatos/metabolismo , PolimerizaçãoRESUMO
Aromatherapy has been suggested as an alternative therapeutic method for the treatment of atopic dermatitis (AD), eczema and other skin diseases. In the current study, the anti-atopic properties of the volatile organic compounds of Chamaecyparis obtusa (VOCCo) were examined to determine whether they are amenable for use as a pharmaceutical candidate. The alterations in histological features, serum IgE levels and mast cell infiltration following exposure to VOCCo were determined in a 2,4-dinitrochlorobenzene (DNCB)-induced AD-like mouse model. The results of these experiments demonstrated that VOCCo inhibited the development of AD-like skin lesions by reducing the serum IgE level and mast cell infiltration into the dermal and subcutaneous layers. This was supported by screening of immune cytokine mRNAs, including interleukin (IL)-1ß and IL-6 from the skin of DNCB-treated mice. The expression of IL-1ß and IL-6 in the skin lesions of mice was dose-dependently inhibited by treatment with VOCCo. Furthermore, treatment with VOCCo resulted in the recovery of histopathological features in AD-like skin lesions. These results suggest that VOCCo may have therapeutic and preventive effects for the development of AD.
Assuntos
Chamaecyparis/química , Dermatite Atópica/patologia , Extratos Vegetais/farmacologia , Pele/efeitos dos fármacos , Compostos Orgânicos Voláteis/farmacologia , Animais , Chamaecyparis/metabolismo , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/terapia , Dinitroclorobenzeno/toxicidade , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Imunoglobulina E/sangue , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/metabolismo , Pele/metabolismo , Pele/patologia , Compostos Orgânicos Voláteis/isolamento & purificaçãoRESUMO
BACKGROUND: An assessment was made of the repellency to female stable flies of tamanu nut oil fatty acids or their esters alone (each 0.5 mg cm(-2) ) or in combination with cuminyl alcohol, cuminaldehyde and α-phellandrene (each 0.25 mg cm(-2) ), using an exposed human hand bioassay. Results were compared with those of synthetic repellent DEET (0.25 mg cm(-2) ). RESULTS: Based upon protection time (PT) (time to first bite of stable fly), oleic acid, linoleic acid, methyl oleate or methyl linoleate synergised the repellency of each monoterpenoid and DEET. For example, the binary mixture of oleic acid and cuminyl alcohol (PT 2.05 h) resulted in significantly greater repellency than either oleic acid (0.55 h), cuminyl alcohol (0.70 h) or DEET alone (1.50 h). The binary mixtures of oleic acid and cuminyl alcohol or DEET (PT 2.10 h) did not differ significantly in repellency. The structure-activity relationship indicates that the degree of saturation, the side chain length and the functional group of fatty acids appear to play a role in determining the fatty acid repellency to stable flies. CONCLUSION: Mixtures formulated from fatty acid and monoterpenoid could be useful as potential repellents for protecting humans and possibly domestic animals from bites caused by stable fly.
Assuntos
Calophyllum/química , Repelentes de Insetos/farmacologia , Muscidae/efeitos dos fármacos , Óleos de Plantas/farmacologia , Terpenos/farmacologia , Animais , DEET/farmacologia , Ésteres , Ácidos Graxos/química , Ácidos Graxos/farmacologia , Feminino , Humanos , Repelentes de Insetos/química , Nozes/química , Óleos de Plantas/química , Relação Estrutura-Atividade , Terpenos/químicaRESUMO
The sap of Acer okamotoanum has been termed 'bone-benefit-water' in Korea owing to its mineral and sugar content. In particular, the calcium (Ca) and potassium (K) concentrations of the sap of Acer okamotoanum are 40- and 20-times higher, respectively, than commercial spring water. In the present study, we examined whether Acer okamotoanum sap improves or prevents hypertension-like symptoms in a rat model. Male Sprague-Dawley rats (8-weeks-old) were provided commercial spring water supplemented with 25, 50 or 100% Acer okamotoanum sap, 3% potassium ions (K+) or captopril, and treated daily for 2 weeks with NG-nitro-L-arginine methyl ester (L-NAME; 100 mg/kg/day) by subcutaneous injection, in order to induce hypertensive symptoms. Rats were euthanized 6 h following the final injection. To assess the effect of the sap on hypertension-like symptoms, we examined the mean blood pressure (BP), protein levels and localization of endothelial nitric oxide synthase (eNOS) in the descending aorta of the rats. BP levels were significantly lower in hypertensive rats received 25, 50 and 100% sap compared with rats who were administered only commercial spring water. Protein levels of eNOS were repressed in L-NAME-only-treated rats, but were elevated in the descending aorta of rats administered captopril, K+ water and Acer okamotoanum sap (25, 50 and 100%) up to the level of the sham group provided commercial spring water, and then injected with dimethyl sulfoxide for the same period of time. Localized eNOS protein was abundantly expressed in the perivascular descending aorta adipose tissue of the rats. Taken together, these results demonstrated that the sap of Acer okamotoanum ameliorated high BP induced by L-NAME treatment in a rat model.
Assuntos
Acer/química , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Inibidores Enzimáticos , Hipertensão/induzido quimicamente , NG-Nitroarginina Metil Éster , Preparações de Plantas/farmacologia , Animais , Cálcio/metabolismo , Modelos Animais de Doenças , Hipertensão/enzimologia , Hipertensão/patologia , Imuno-Histoquímica , Masculino , NG-Nitroarginina Metil Éster/toxicidade , Óxido Nítrico Sintase Tipo III/metabolismo , Potássio/metabolismo , Ratos , Ratos Sprague-Dawley , Água/farmacologiaRESUMO
In this study, the antibacterial activity of essential oil from Chamaecyparis obtusa (Sieb. et Zucc) leaves and twigs was investigated. The test strains were Klebsiella pneumoniae, Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, Escherichia coli, Legionella pneumophila, and Methicilline-resistant Staphylococcus aureus. Antibacterial activity was estimated by measuring bacterial growth inhibition. Histopathological examination was also performed. C. obtusa oil distinctly inhibited the growth of all test strains and exhibited the strongest antibacterial activity against L. monocytogenes. It was chromatographically divided into several fractions. The fractions were further tested against antibacterial activity and their chemical compositions were analyzed. The fraction containing terpinen-4-ol (TA) showed high antibacterial activity toward all strains tested. Tests with authentic samples showed that TA played a major role in the antibacterial activity of C. obtusa oil, and in a mice test, the oil actively minimized inflammation by S. aureus.
Assuntos
Antibacterianos/farmacologia , Bactérias/crescimento & desenvolvimento , Chamaecyparis/química , Doenças Transmitidas por Alimentos/microbiologia , Inibidores do Crescimento/farmacologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Animais , Antibacterianos/análise , Bactérias/efeitos dos fármacos , Feminino , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/tratamento farmacológico , Humanos , Camundongos , Camundongos Endogâmicos ICR , Óleos Voláteis/análise , Óleos de Plantas/análise , Terpenos/análise , Terpenos/farmacologiaRESUMO
This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2 mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.
Assuntos
Antifúngicos/isolamento & purificação , Fungos/efeitos dos fármacos , Leptospermum/química , Óleos Voláteis/isolamento & purificação , Óleos de Plantas/isolamento & purificação , Syzygium/química , Antifúngicos/farmacologia , Cromatografia em Camada Fina , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologiaRESUMO
The insecticidal activity of phytochemicals isolated from the roots of Phryma leptostachya var. asiatica against third instar larvae of Culex pipiens pallens, Aedes aegypti, and Ocheratatos togoi was examined. The two constituents of P. leptostachya var. asiatica roots were identified as the leptostachyol acetate (I) and 8'-acetoxy-2,2',6-trimethoxy-3,4,4',5'-dimethylenedioxyphenyl-7,7'-dioxabicyclo[3.3.0]octane (II) by spectroscopic analysis. Compound I was lethal to C. pipiens pallens, A. aegypti, and O. togoi at 10 ppm. Compound II showed weak or no insecticidal activity against three mosquito species at 10 ppm. The LC(50) values of I against C. pipiens pallens, A. aegypti, and O. togoi were 0.41, 2.1, and 2.3 ppm, respectively. Naturally occurring P. leptostachya var. asiatica root-derived compounds merit further study as potential mosquito larval control agents or lead compounds.
Assuntos
Culicidae , Inseticidas , Larva , Lignanas/análise , Magnoliopsida/química , Raízes de Plantas/química , Aedes , Animais , Culex , OchlerotatusRESUMO
The toxic effects of Eucalyptus globulus leaf oil-derived monoterpenoids [1,8-cineole, l-phellandrene, (-)-alpha-pinene, 2-beta-pinene, trans-pinocarveol, gamma-terpinene, and 1-alpha-terpineol] and the known Eucalyptusleaf oil terpenoids (beta-eudesmol and geranyl acetate) on eggs and females of the human head louse, Pediculus humanus capitis, were examined using direct contact and fumigation bioassays and compared with the lethal activity of delta-phenothrin and pyrethrum, two commonly used pediculicides. In a filter paper contact bioassay with female P. h. capitis, the pediculicidal activity was more pronounced with Eucalyptus leaf oil than with either delta-phenothrin or pyrethrum on the basis of LT(50) values (0.125 vs 0.25 mg/cm(2)). 1,8-Cineole was 2.2- and 2.3-fold more toxic than either delta-phenothrin or pyrethrum, respectively. The pediculicidal activities of (-)-alpha-pinene, 2-beta-pinene, and (E)-pinocarveol were comparable to those of delta-phenothrin and pyrethrum. l-Phellandrene, gamma-terpinene, and 1-alpha-terpineol were relatively less active than delta-phenothrin and pyrethrum. beta-Eudesmol and geranyl acetate were ineffective. 1-alpha-Terpineol and (E)-pinocaveol were highly effective at 0.5 and 1.0 mg/cm(2), respectively, against P. h. capitis eggs. At 1.0 mg/cm(2), (-)-alpha-pinene, 2-beta-pinene, and gamma-terpinene exhibited moderate ovicidal activity, whereas little or no ovicidal activity was observed with the other terpenoids and with delta-phenothrin and pyrethrum. In fumigation tests with female P. h. capitis at 0.25 mg/cm(2), 1,8-cineole, (-)-alpha-pinene, (E)-pinocarveol, and 1-alpha-terpineol were more effective in closed cups than in open ones, indicating that the effect of the monoterpenoids was largely due to action in the vapor phase. Neither delta-phenothrin nor pyrethrum exhibited fumigant toxicity. Eucalyptus leaf oil, particularly 1,8-cineole, 1-alpha-terpineol, and (E)-pinocaveol, merits further study as potential pediculicides or lead compounds for the control of P. h. capitis.