495 research outputs found

    Arsenic Carcinogenesis in the Skin

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    Chronic arsenic poisoning is a world public health issue. Long-term exposure to inorganic arsenic (As) from drinking water has been documented to induce cancers in lung, urinary bladder, kidney, liver and skin in a dose-response relationship. Oxidative stress, chromosomal abnormality and altered growth factors are possible modes of action in arsenic carcinogenesis. Arsenic tends to accumulate in the skin. Skin hyperpigmentation and hyperkeratosis have long been known to be the hallmark signs of chronic As exposure. There are significant associations between these dermatological lesions and risk of skin cancer. The most common arsenic-induced skin cancers are Bowen's disease ( carcinoma in situ), basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Arsenic-induced Bowen's disease (As-BD ) is able to transform into invasive BCC and SCC. Individuals with As-BD are considered for more aggressive cancer screening in the lung and urinary bladder. As-BD provides an excellent model for studying the early stages of chemical carcinogenesis in human beings. Arsenic exposure is associated with G2/M cell cycle arrest and DNA aneuploidy in both cultured keratinocytes and As -BD lesions. These cellular abnormalities relate to the p53 dysfunction induced by arsenic. The characteristic clinical figures of arsenic- induced skin cancer are: (i) occurrence on sun-protected areas of the body ; (ii) multiple and recrudescent lesions. Both As and UVB are able to induce skin cancer. Arsenic treatment enhances the cytotoxicity, mutagenicity and clastogenicity of UV in mammalian cells. Both As and UVB induce apoptosis in keratinocytes by caspase-9 and caspase-8 signaling, respectively. Combined UVB and As treatments resulted in the antiproliferative and proapoptotic effects by stimulating both caspase pathways in the keratinocytes. UVB irradiation inhibited mutant p53 and ki -67 expression, as well as increased in the number of apoptotic cells in As- BD lesions which resulted in an inhibitory effect on proliferation. As -UVB interaction provides a reasonable explanation for the rare occurrences of arsenical cancer in the sun-exposed skin. The multiple and recurrent skin lesions are associated with cellular immune dysfunction in chronic arsenism. A decrease in peripheral CD4+ cells was noticed in the inhabitants of arsenic exposure areas. There was a decrease in the number of Langerhans cells in As-BD lesion which results in an impaired immune function on the lesional sites. Since CD4+ cells are the target cell affected by As, the interaction between CD4+ cells and epidermal keratinocytes under As affection might be closely linked to the pathogenesis of multiple occurrence of arsenic -induced skin cancer. In this review, we provide and discuss the pathomechanisms of arsenic skin cancer and the relationship to its characteristic figures. Such information is critical for understanding the molecular mechanism for arsenic carcinogenesis in other internal organs

    Potential Ornamental Freshwater Crustacean (Family: Atyidae): Ecology, Biology and Feeding Habits

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    This study was conducted to study the biology, ecology and feeding habits of . 1iYopsis moluccensis in Sungai Bengoh and Sungai Turn and the effects of changes in the aquatic environment towards this species. . liropsis moluccensis shrimps were found living abundantly in shady, fast-flowing waters. The shrimps are omnivores and feeds on almost anything it filters through its setae. Twelve water quality parameters, namely TSS, TDS, BOD, COD, DO, pH, ammonia, orthophosphate, nitrates, conductivity, turbidity and temperature were used to determine the quality of the river water. River water was sampled at the two rivers for comparison purposes. Statistical analysis showed that orthophosphate, ammonia and total dissolved solids was not significantly different among stations. The culture of the organisms was unsuccessful due to factors such as salinity, temperature, water current and light exposure. The suitable salinity for culturing of this species remains unknown

    Raw data_artificial rock pools_CSY.xlsx

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    Coastal benthic and mobile organisms were sampled from drill-cored artificial rock pools and emergent rock surfaces on selected granite rock revetments on reclaimed coastlines in Penang, Malaysia. Sampling was done using quadrats and monitoring was conducted over a three-year period . Sessile organisms and algae were recorded in percentage coverage and mobile organisms in counts. All organisms were identified In-situ to the lowest taxonomic level possible.<br

    Developmental Biology And Genetic Diversity Of Selected Neritidae In Malaysia With An Emphasis On Nerita Balteata

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    The gastropods in this study are from the genus Nerita found in the rocky and muddy intertidal zones along the coasts of Malaysia. The species diversity was analyzed, morphological descriptions were made, and barcodes of cytochrome oxidase I were generated for each of the 12 species of nerites found. The nuclear gene, ATPS-α, successfully determined the phylogenetic status of each species. Twenty-one populations of the focal species of this study, N. balteata, were sequenced for 16S rRNA gene fragments to determine the population structure of nerites found in this region. Despite geographic and oceanographic barriers and habitat boundaries, the nerites managed to maintain a homogeneous structure between Peninsular Malaysia, Sarawak, and Sabah. Genetic distances between populations were low, phylogenetic trees did not exhibit distinct clades which denoted singular populations, and network diagrams produced two major haplotypes with most populations accounted for in each

    The historical evolution of accounting in China: the effects of culture.

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    Muchos estudios recientes han afirmado que China integra en su sistema contable sus reglas tradicionales, sus intereses culturales y su estilo de vida. La “cultura” sería el punto dominante en su sistema contable. Hofstede, Gray, Mueller y otros investigadores empíricos de la contabilidad, que enfatizan la influencia de los efectos culturales en la configuración de los sistemas contables nacionales, sostienen que la Contabilidad China ha sido dominada por la “Cultura” China. Este trabajo presenta tres de entre las variables culturales chinas, a saber, Confucianismo, Feng Shui, Budismo, Yin-Yang, etc., que han marcado los comportamientos y las técnicas contables chinas. En China, el sistema contable se basó tradicionalmente en las prácticas confucianistas y en la antigua sabiduría; estos elementos todavía influyen en el sistema actual. En este artículo se estudian las influencias desde una perspectiva histórica en relación con las variables culturales chinas. Las influencias examinadas se centran en los metódos de la teneduría de libros, en las prácticas contables, en la información contable, etc. Many recent studies have argued that China integrates its traditional rules, cultural interests and its life style into its accounting system. “Culture” is the main point for their accounting system. Hofstede, Gray, Mueller, and some other empiricist accounting researchers who emphasize the influence of cultural effects on national accounting improvements claim that Chinese Accounting has been dominated by Chinese “Culture”. This paper presents three Chinese cultural variables (e.g. Confucianism, Feng Shui, Buddhism, Yin-Yang, etc.) that have shaped Chinese accounting behaviors and techniques. In China, the Chinese accounting system was traditionally based on Confucian practices and ancient wisdom; these elements still influence the current system. In this paper, the influences are discussed from a historical perspective with regard to cultural variables in China. The influences studied focused on bookkeeping methods, accounting practices, accounting information, etc.Factores ambientales, contabilidad, cultura, China, Confucianismo, Feng Shui, polaridad Yin-Yang, contabilidad por partida simple y partida doble. Environmental Factors, Accounting, Culture, China, Confucianism, Feng Shui, Yin-Yang Polarity, Single & Double-Entry bookkeeping methods.

    現代美術與繪畫創作理念

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    [[abstract]]● 目錄 ● 序 ● 簡歷 ● 作品 1. 農 Farming 2. 展覽會 Exhibition 3. 蘇州 Suchou 4. 憩 The Yellow Guitar Resting in Silence 5. 荷 Lotuses 6. 牧 Pasturing 7. 室內樂 Chamber Concert 8. 繁華水影 Prosperity be the River 9. 老牆、古榕 Wall and Banyans 10. 溪邊人家 A Village by the Stream 11. 掬一束花香 Fragrance 12. 相、象 Image 13. 出航 Setting Sail 14. 人體 A young Woman 15. 泊 Anchoring 16. 荷影 Dancing Shadows of Lutuses 17. 水鄉 Water City 18. 聖誕紅 Christmas Trees 19. 花影 Shadows of Flowers 20. 夏荷 Lotuses on a Summer Morning 21. 望安海邊 The Seashore at Wang-An 22. 采菊東籬下 Chrysanthemums 23. 背影 A View from the back 24. 草原上的牛車 Oxcart on the Prairie 25. 雙美圖 The fair Ladies 26. 漁村一隅 Fishery Village 27. 當晚滿霞天 Dusk 28. 玫瑰 Rose

    Defective Beta(1)-Integrins Expression in Arsenical Keratosis and Arsenic -Treated Cultured Human Keratinocytes

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    Background: beta(1)-integrins, which localize to the basolateral surface of basal keratinocytes, are important in the differentiation control and proliferation of the epidermis. Many cutaneous diseases with perturbed differentiation, including arsenical keratosis, show altered patterns of integrin distribution and expression. Arsenic may induce arsenical keratosis through the differentiation and apoptosis aberration by integrins. The purpose of this study is to investigate the role of integrin and arsenic in the pathogenesis of arsenical keratosis. Methods: Twenty- five specimens obtained from 25 patients with arsenical keratosis disease were studied. Immunohistochemistry staining to beta(1), alpha(2) beta(1), or alpha(3)beta(1) integrins was performed in arsenical keratosis and clinically normal perilesional skin. Western blotting was used to assess the expression of integrin beta(1) and focal adhesion kinase (FAK) in arsenic-treated cultured keratinocytes. Results: A decreased expression of beta(1), alpha(2)beta(1), or alpha(3)beta(1) integrins was demonstrated in arsenical keratosis and clinical normal perilesional skin in a large proportion of arsenical keratosis cases studied. The expressions of integrin beta(1) and FAK were both decreased in arsenic- treated keratinocytes. Conclusions: Our results suggest that arsenic induces abnormal differentiation in arsenical keratosis via the effects of integrin expression in keratinocytes

    DRILLING PREDATION ON NERITID EGG CAPSULES BY THE MURICID SNAIL REISHIA CLAVIGERA

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    The egg capsules of neritid snails (Gastropoda: Neritimorpha) are made of a tough inner organic layer and an outer calcareous layer for further reinforcement. Such hard capsules are less susceptible to mechanical damage compared with soft or thin capsules of other gastropods, and there have been only a few reports of predation on neritid eggs. Here, we describe drilling predation on the reinforced egg capsule of Nerita japonica by Reishia clavigera (Caenogastropoda: Muricidae) on a high intertidal rocky shore in central Japan. The muricid makes a small, elliptical drill hole in the capsule lid by the use of both an accessory boring organ (ABO) and a radula, as it does in mollusc and barnacle shells. The etching around the hole by the acid secretion from the ABO, which can be observed under a dis-secting microscope and by scanning electron microscopy, should provide an effective way to identify muricid predation on neritid eggs, probably not only by R. clavigera but also by other species in the warm temperate to tropical regions all over the world. Reishia clavigera made drill holes in c. 14 % of the capsules, making it possibly the main cause of mortality for neritid eggs at the study site. However, this mortality rate is lower than those previously reported for caenogastropod eggs with softer capsules. All penetrated capsules of N. japonica were white (rather than brownish) and newly laid, suggesting that their acid-resistant organic layer had yet to harden at the time of radular rasping. The thick organic layer and calcareous coating are an effective armour, not only against the usual type of grazing but also against more sophisticated predation involving the chemical and mechanical boring of Muricidae

    Coastal Macroinvertebrate Study in Penang Island, Malaysia

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    Land reclamation in Penang began two decades ago and is still rampant with large reclamation projects planned to be executed in the near future. The present study provides the first information on effects of land reclamation in Penang towards the coastal macroinvertebrates. This study assessed the abundance, diversity, and evenness of coastal invertebrates assumed to be the foremost affected when land is reclaimed. Three kinds of areas were focused on: reclaimed, unclaimed (adjacent to reclaimed), and undisturbed. A total of 53 species of macroinvertebrates from 10 classes (Gastropoda, Bivalvia, Polychaeta, Malacostraca, Maxillopoda, Echinoidea, Polyplacophora, Branchiopoda, Scaphopoda, and Holothuroidea) were sampled. Reclaimed areas were moderately rich in species averaging 11 species compared to 7 species in adjacent and 14 in undisturbed areas. Species richness was the highest in Teluk Aling (an undisturbed area) with 22 species, and was the lowest in Gurney Drive (an adjacent area) with 2 species. The average species diversity and evenness on reclaimed land was the lowest with values of 1.9974 and 0.5787, respectively. The diversity was higher by 5.07% in adjacent areas and by 22.92% in undisturbed areas compared to reclaimed areas. Species evenness was 29.75% higher in unreclaimed areas and 17.87% higher in undisturbed areas compared to reclaimed areas. Land reclamation reduces species diversity and evenness, and to a lesser extent, species richness
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