The relationship between the acid and alkaline phosphatase activity and the adherence of Candida parapsilosis to human buccal epithelial cells

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Buccal alterations in diabetes mellitus

Long standing hyperglycaemia besides damaging the kidneys, eyes, nerves, blood vessels, heart, can also impair the function of the salivary glands leading to a reduction in the salivary flow. When salivary flow decreases, as a consequence of an acute hyperglycaemia, many buccal or oral alterations can occur such as: a) increased concentration of mucin and glucose; b) impaired production and/or action of many antimicrobial factors; c) absence of a metalloprotein called gustin, that contains zinc and is responsible for the constant maturation of taste papillae; d) bad taste; e) oral candidiasis f) increased cells exfoliation after contact, because of poor lubrication; g) increased proliferation of pathogenic microorganisms; h) coated tongue; i) halitosis; and many others may occur as a consequence of chronic hyperglycaemia: a) tongue alterations, generally a burning mouth; b) periodontal disease; c) white spots due to demineralization in the teeth; d) caries; e) delayed healing of wounds; f) greater tendency to infections; g) lichen planus; h) mucosa ulcerations. Buccal alterations found in diabetic patients, although not specific of this disease, have its incidence and progression increased when an inadequate glycaemic control is present

MTH1 deficiency selectively increases non-cytotoxic oxidative DNA damage in lung cancer cells: more bad news than good?

Representative images of “Comets” and the corresponding intensity profiles, showing (i) ~ 5% Tail DNA damage, typical of the NSCLC cells treated with no siRNA or scramble siRNA, and analysed by regular Fpg-modified alkaline comet assay (0.8 U Fpg/gel); and (ii) comets showing ~ 10% tail DNA, typical of the NSCLC cells treated with MTH1 siRNA. Superimposed on the Comet images are the image analysis software (Komet 5.5, Andor Technology) determined boundaries demarcating the ‘Comet head’ (pink circle) and ‘tail extent’ (vertical orange line) (Barber RC, Hickenbotham P, Hatch T, Kelly D, Topchiy N, Almeida GM, et al. Radiation-induced transgenerational alterations in genome stability and DNA damage. Oncogene. 2006;25(56):7336–7342). % tail DNA = 100 - % head DNA; % head DNA = (integrated optical head intensity / (integrated optical head intensity + integrated optical tail intensity)) × 100. (PDF 1431 kb

A new, semi-automated technique for quantification of Candida adherence to denture acrylic surfaces

Adherence of Candida species to various host surfaces is an important prerequisite for colonization and pathogenesis. Researchers have problems in quantifying candidal adherence to plastic surfaces (used for fabrication of prostheses) due to coaggregation of adherent yeasts and to the laborious, time-consuming method of microscopic quantification. We describe here, a semiautomated image analysis system which is superior to conventional visual light microscopic techniques of quantifying yeasts attached to solid substrates such as acrylic. The results demonstrated a significant positive correlation between the number of cells quantified by traditional light microscopy and the corresponding area obtained by the semi-automated image analysis system (r = 0.83, P < 0.02). The new system is simple, less laborious and is particularly useful when the adherent attributes of a large battery of yeasts are characterized.link_to_subscribed_fulltex

Relative cell surface hydrophobicity of Candida parapsilosis and Candida albicans.

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The relationship between the acid and alkaline phosphatase activity and the adherence of clinical isolates of Candida parapsilosis to human buccal epithelial cells

Candida parapsilosis is an emerging fungal pathogen implicated in many diseases, especially in compromised hosts. Candidal colonization and infection depends on the initial ability to adhere to host surfaces, which in turn depends upon the cell wall components and the allied structures of both the host and the fungus. Examination of a miscellaneous collection of 24 C parapsilosis isolates, from both superficial and deep infections, for their potential pathogenic traits displayed a relationship between the phosphatase activity measured with p-nitrophenol phosphate and adhesion of the yeasts to human buccal epithelial cells (BECs). Significant intraspecies differences were seen in both the alkaline and acid phosphatase activity as well as in their adhesion to BECs (p<0.0001). The acid phosphatase activity of the superficial isolates was significantly greater (152%) than that of the systemic isolates (p=0.0352). A highly significant positive correlation was also established between the yeast adhesion to BECs and both the acid (r=0.88, p<0.0001) and alkaline (r=0.9, p<0.0001) phosphatase activity. These relationships, described here for the first time, imply that phosphatases of Candida species may play a crucial role in potentiating their virulence.link_to_subscribed_fulltex

Adhesion to denture acrylic surfaces and relative cell-surface hydrophobicity of Candida parapsilosis and Candida albicans

C. parapsilosis is an opportunistic emerging pathogen which together with C. albicans causes diseases in immunocompromised patients. Adhesion of Candida species to various surfaces is an important event in colonization and pathogenesis, and the relative cell-surface hydrophobicity (CSH) of the organism is a contributory physical force involved. Therefore, in vitro adhesion to acrylic surfaces and relative CSH of 24 isolates of C. parapsilosis and 10 isolates of C. albicans were studied. There was no significant difference in relative adhesion of C. parapsilosis isolates and C. albicans, although the former demonstrated a tendency for increased adhesion. There was significant intra-species variation in adhesion among isolates of C. parapsilosis (p=0.0001), but not C. albicans. In general, C. parapsilosis isolates demonstrated a two-fold greater relative CSH than C. albicans (p=0.0003). When the relative CSH of superficial and systemic isolates of C. parapsilosis were compared, the former showed a significantly higher (49.15%) relative CSH than their systemic counterparts (p<0.01). A highly significant positive correlation between adhesion and relative CSH of C. parapsilosis (p=0.74, p<0.0001) was also noted. Taken together, these data suggest that the attributes of adhesion and relative CSH of Candida species may contribute differentially in varying disease states of the human host, such as superficial and systemic Candida infections.link_to_subscribed_fulltex