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S Anil

Publications and source records attributed to S Anil.

At least 19 recordsLinked to original sources
PubMed2003

Phenotypic diversity of oral C. albicans isolated on single and sequential visits in an HIV-infected Chinese cohort.

HIV-infected individuals maintain multiple oral C. albicans strains over time that are thought to undergo microevolution in terms of both phenotypic and genotypic features. To study this phenomenon, a 12-month prospective study was conducted in a cohort of 16 HIV-infected ethnic Chinese individuals with (A) and without (B) symptoms of oropharyngeal candidiasis to evaluate the phenotype distribution among oral C. albicans isolates during disease progression. Oral rinse samples were obtained and up to five C. albicans colony-forming units were selected per each visit, during the one year period of multiple visits. The isolates were phenotyped using two commercially available biotyping kits, the API 20C system, API ZYM system, and a plate test for resistance to boric acid. A total of 261 C. albicans strains in group A were differentiated into 67 biotypes, while 42 biotypes were seen amongst the 182 isolates from group B. The major biotypes in the two groups were similar and were in decreasing order of prevalence J1R, J1S, J6S, J6R, J2S, K1S, J10R, K1R, and K6R; 48 different biotypes were seen in group A and 24 in group B, with some uniquely represented in each group, leading to a significant association between the prevalence of the biotypes J1S and J2S and symptomatic candidiasis (p<0.05). Taken together this study illustrates the wide phenotypic spectrum of oral C. albicans associated with HIV-infection.

Adult↗
PubMed2003

Adhesion and cell-surface-hydrophobicity of sequentially isolated genetic isotypes of Candida albicans in an HIV-infected Southern Chinese cohort.

Objectives of the study were to investigate the variability in yeast adhesion and cell-surface-hydrophobicity (CSH) during human immunodeficiency virus (HIV) disease progression, using a total of 60 sequential Candida albicans isolated from oral rinse samples of seven HIV-infected individuals with (4) and without (3) clinical symptoms of oropharyngeal candidosis. Significant differences in the adhesion to buccal epithelial cells (BECs) during sequential visits were observed for all genetic isotypes in five of the seven individuals and three isotypes belonging to the sixth individual. A single isotype of patient HK1 and another of HK4 (genotype I) demonstrated significant variations in their CSH during sequential visits whereas no such differences were noted for the remaining genotypes. On Spearman correlation analysis an isotype from HK1 demonstrated a significant increased adherence to BECs and CSH during HIV disease progression whereas no such correlation was noted for the remaining isotypes studied. No significant differences in adherence to BECs or CSH values were observed between the symptomatic oral candidosis and the asymptomatic carrier group. Further, on regression analysis only the single isotype of HK1 demonstrated a significant positive correlation between adherence to BECs and CSH whereas no such correlation was observed when all tested Candida isolates were pooled and evaluated as a single, large group.

AIDS-Related Opportunistic Infections↗
PubMed2003

Brief exposure to antimycotics reduces the extracellular phospholipase activity of Candida albicans and Candida tropicalis.

BACKGROUND: Although the phospholipase activity is considered a potential virulence determinant of the pathogenic Candida species, the effect of antimycotics on this attribute is not known. Hence we evaluated the phospholipase activity in 10 isolates each of Candida albicans and Candida tropicalis, after their exposure to antifungals. METHODS: The impact of antimycotics on phospholipase activity was also assessed after exposure of the isolates to sub-minimum inhibitory concentrations of nystatin, amphotericin B and fluconazole. RESULTS: All Candida isolates investigated exhibited phospholipase activity (Pz). In general C. ALBICANS showed relatively higher P(z) activity than C. tropicalis , and exposure of the isolates to antimycotics led to a significant (p < 0.05) reduction in the phospholipase activity. Nystatin and amphotericin B, but not fluconazole, significantly reduced the phospholipase activity of both Candida species. CONCLUSION: These observations, while confirming the higher virulence of C. albicans relative to C. tropicalis, demonstrate for the first time the effect of antifungal agents on extracellular phospholipases of these common opportunistic pathogens.

AIDS-Related Opportunistic Infections↗
PubMed2002

The impact of polyene, azole, and DNA analogue antimycotics on the cell surface hydrophobicity of Candida albicans and Candida tropicalis in HIV infection.

Oral candidiasis is the most common opportunistic infection in individuals infected with the human immunodeficiency virus. Though Candida albicans is the major aetiological agent, non-albicans species such Candida tropicalis are now emerging as important agents of such infection. The Candida cell surface hydrophobicity (CSH) is considered a critical factor contributing to its colonization potential and virulence. It is also known that brief exposure to sub-cidal concentrations of antifungal agents is a likely scenario in the oral environment where the administered drugs are diluted continuously due to the flushing action of saliva. Hence the objective of the present study was to compare the CSH of 10 isolates each of C. albicans and C. tropicalis from HIV-infected individuals following brief exposure (1 hour) of isolates to sub-therapeutic concentrations of nystatin, amphotericin B, ketoconazole, fluconazole and 5-flurocytosine. The CSH was assessed by a previously described biphasic aqueous-hydrocarbon assay. The mean percentage reduction of CSH of C. albicans following brief exposure to nystatin, amphotericin B, ketoconazole, fluconazole and 5-flurocytosine was 27.33 (p < 0.001), 21.34 (p < 0.05), 11.74 (p > 0.05), 18.4 (p > 0.05) and 14.64 (p > 0.05) respectively. The mean percentage reduction of CSH of C. tropicalis following brief exposure to nystatin, amphotericin B, ketoconazole, fluconazole and 5-flurocytosine was 33.81 (p < 0.01), 28.88 (p < 0.01), 12.6 (p > 0.05), 21.53 (p > 0.05) and 17.68 (p > 0.05) respectively. A significant interspecies variation in CSH was observed for nystatin and amphoterecin B. Overall the results reveal that the CSH of C. albicans is affected to a significantly lesser degree compared with C. tropicalis when exposed to the antifungals. These data further illustrate another mode of action of antifungals on Candida leading to a reduction in the CSH and thereby the yeast adherence to host tissues.

AIDS-Related Opportunistic Infections↗
PubMed2002

Impact of lysozyme and lactoferrin on oral Candida isolates exposed to polyene antimycotics and fluconazole.

OBJECTIVE: To assess the antifungal activity of lysozyme and lactoferrin on 10 oral isolates each of Candida albicans and Candida tropicalis following their brief exposure (I h) to subtherapeutic concentrations of two polyene drugs - nystatin, amphotericin B, and an azole -fluconazole. METHODS: Yeasts were sequentially exposed to subtherapeutic concentrations of antifungals and then to either lysozyme or lactoferrin and the viability evaluated by quantifying colony-forming units. RESULTS: The exposure of both C. albicans and C. tropicalis isolates to all three antifungal agents significantly increased their susceptibility to lysozyme (P < 0.05) but not to lactoferrin. Exposure to the two polyene drugs had a lesser impact on the lysozyme susceptibility of both Candida species compared with the azole drug. Both interspecies and intraspecies sensitivity to lysozyme was noted and C. albicans was less susceptible than C. tropicalis. CONCLUSIONS: Lysozyme, in addition to being a potent natural antifungal agent, may act synergistically with the studied antimycotics.

Amphotericin B↗
PubMed2001

The effect of oral bacteria on Candida albicans germ-tube formation.

A total of eight bacterial isolates belonging to six species, and a select group of 12 oral Candida albicans isolates, were used to study the effect of bacteria on germ-tube formation. Briefly, each bacterial suspension (10(5-6) cells/ml) was mixed with a C. albicans suspension (10(7) cells/ml) and incubated at 37 degrees C for 90 min with bovine serum, and the percentage germ-tube-positive Candida cells was quantified using a haemocytometer, under light microscopy. In general, out of eight bacteria, Streptococcus sanguis SK21A, Streptococcus salivarius SK56, Escherichia coli ATCC 25922, and S. salivarius OBU3 suppressed germ-tube formation to varying degrees, with different C albicans isolates. Porphyromonas gingivalis Pg 50, Lactobacillus casei ATCC 7469 and Prevotella intermedia OBU4 elicited significant enhancement of germ-tube formation, whereas S. sanguis OBU 2 had no effect. E. coli ATCC 25922 was the only organism to show statistically significant suppression of germ-tube formation (p=0.0312). A significant increase in the germ tube production of C. albicans isolated from HIV-infected compared with HIV-free individuals was also noted. The current results tend to suggest that commensal and transient oral bacterial populations may selectively influence the differential expression of germ-tube-forming ability of C. albicans isolates.

Candida albicans↗
PubMed2001

Post-antifungal effect of polyene, azole and DNA-analogue agents against oral Candida albicans and Candida tropicalis isolates in HIV disease.

Oropharyngeal candidiasis (OPC) is the most frequent AIDS-associated opportunistic infection, as up to 90% of HIV-infected individuals suffer at least one episode during the course of their disease. Various in vivo and in vitro procedures have been used to assess the effectiveness of antifungal agents used in HIV infection. In the present study, we evaluated in vitro the minimum inhibitory concentration (MIC) and the post-antifungal effect (PAFE) of two polyenes, two azoles and one DNA-analogue against 10 oral isolates of Candida albicans and 10 of Candida tropicalis, all from HIV-infected individuals, in order to obtain basic data on the pharmacodynamics of these drugs. One-hour exposure to twice the MIC of all the drugs, except fluconazole, elicited a consistently high PAFE in both Candida species. Furthermore, the PAFE elicited by the antifungals (except fluconazole) was significantly prolonged for C. tropicalis compared with C. albicans. This speedy recovery of C. albicans isolates exposed to transient low concentrations of antifungals appeared to reflect its virulence compared with lesser potent species, such as C. tropicalis. Taken together, the current data, while confirming the existence of PAFE in a non-albicans species of Candida, also provide further clues for the recalcitrance of C. albicans species in the face of antifungal therapy for oropharyngeal candidiasis.

AIDS-Related Opportunistic Infections↗
PubMed2001

The impact of chlorhexidine gluconate on the relative cell surface hydrophobicity of oral Candida albicans.

OBJECTIVES: Adherence of Candida albicans has been implicated as the first step in the pathogenesis of oral candidosis, and its relative cell surface hydrophobicity (CSH) a contributory physical force. Chlorhexidine gluconate is by far the commonest antiseptic mouthwash prescribed in dentistry. The intra-oral concentrations of the retained chlorhexidine mouthwash fluctuate considerably due to the dilution effect of saliva and the cleansing action of the oral musculature. Hence the objective of the present study was to investigate the effect of brief exposure to sub-therapeutic concentrations of chlorhexidine gluconate on the relative CSH of C. albicans. DESIGN: The CSH of the isolates was assessed by a biphasic aqueous-hydrocarbon assay. RESULTS: A statistically significant reduction in CSH was observed following the exposure of Candida isolates to 0.005 and 0.0025% chlorhexidine gluconate. CONCLUSIONS: These results elucidate additional mechanisms by which chlorhexidine gluconate suppress candidal pathogenicity despite a brief period of transient exposure within the oral environment.

Adhesiveness↗
PubMed1999

Metastasis of thyroid carcinoma to the mandible. Case report.

Metastatic tumours to the jaw bones are uncommon. The incidence of jaw bone metastasis is difficult to assess accurately since the usual method to determine the distribution of a metastatic tumour has been by a radiographic skeletal survey in which the jaws are rarely included. At times, metastatic lesions of the orofacial region may be the first evidence of dissemination of a known tumour from its primary site. A case of metastatic follicular carcinoma of the thyroid to the mandible is presented. The present case emphasizes the importance of considering metastasis in the differential diagnosis of a radiolucent lesion in the mandible in a patient with a history of any malignant disease.

Adenocarcinoma, Follicular↗
PubMed1998

Chondrosarcoma of the maxilla. Case report.

Chondrosarcoma is a rare malignant neoplasm of the jaws. The diagnosis of this lesion is mainly based on the histopathological appearance. A case of chondrosarcoma of the maxilla is reported. The origin of this rare tumor in the maxilla, a bone with exclusive membranous ossification, is discussed.

Adult↗
PubMed1997

Oral lesions of HIV and AIDS in Asia: an overview.

The magnitude of HIV infection in the Asian region is increasing dramatically. Oral disease represents an important health problem for HIV-infected individuals, because of its diagnostic, prognostic and therapeutic implications. The documentation and reporting of HIV infection and AIDS in most of the Asian countries has been superficial. Though the epidemiology of HIV infection in Asia has been studied by many investigators, few attempts have been made to summarise the data and assess the magnitude of the problem, the mode of transmission, the spread of infection and clinical pattern of illness. A review of the literature shows that there is hardly any published data on oral manifestations of HIV infection or AIDS from the Asian region. However, some preliminary information is available on the type of lesion presenting in patients from India and Thailand. These observations suggest that oral manifestations are common in HIV-infected and AIDS patients. The pattern of occurrence of various lesions reported appears to show variation from those reports from other parts of the world, but no definitive conclusion can be drawn from these preliminary observations. Further epidemiological studies are necessary to substantiate the present understanding of the nature of oral lesions found in Asian countries.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Gingival enlargement as a diagnostic indicator in leukaemia. Case report.

The acute leukaemias are a group of neoplastic diseases that are characterized by proliferation of immature white cells in the bone marrow and/or blood and are often associated with severe leukopenia, anaemia and thrombocytopenia. Oral manifestations are more common in patients with acute leukaemia. Oral bleeding, gingival enlargement, ulceration and infection in patients with leukaemia have been described. Leukaemic infiltrates in the gingivae are commonly seen in acute monocytic leukaemia. A case of acute monocytic leukaemia in a 34-year-old female who reported with gingival enlargement is presented here. The role of oral lesions as a diagnostic indicator is discussed.

Adult↗
PubMed1996

Squamous cell carcinoma of the gingiva in an HIV-positive patient: a case report.

This article presents a case of gingival squamous cell carcinoma in a patient who was HIV positive but who had no history of pan chewing, smoking, alcohol consumption or nutritional deficiency. Investigations also revealed the presence of superimposed pseudomembranous candidiasis. The case reported reveals that squamous cell carcinoma of the gingiva may occur as an oral manifestation of AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1995

Evaluation of serum beta 2-microglobulin in premalignant and malignant lesions of the oral cavity.

Serum beta-2-microglobulin was estimated in patients with oral leukoplakia, oral submucous fibrosis, and oral cancer. The results were compared with that of an equal number of age- and sex-matched healthy controls. A definite increase in the level of beta 2-microglobulin was observed in patients with oral submucous fibrosis and oral cancer. Though the level of beta 2-microglobulin was found to be high in oral leukoplakia, it was not statistically significant. Further studies will validate the role of beta 2-microglobulin estimation to predict the malignant potential of oral submucous fibrosis.

Adult↗
PubMed1995

Mandibulofacial dysostosis. Case report.

A case of mandibulofacial dysostosis (Treacher Collins syndrome) is presented. Clinical features and skull radiographs revealed typical anomalies associated with the syndrome. Cleft of the soft palate and unerupted multiple supernumerary teeth were present in this case. No haematological, biochemical or immunological abnormalities could be detected in the patient. Pedigree analysis showed an autosomal dominant mode of transmission of the disease. Chromosomal studies did not reveal any structural or numerical discrepancies.

Adolescent↗
PubMed1994

Oral squamous cell carcinoma in a case of dyskeratosis congenita.

Oral manifestations of dyskeratosis congenita (DCG) have received little attention in dental literature. This report is a case of dyskeratosis congenita in a 17-year-old female which was associated with oral lesions such as leukoplakia, superimposed candidal infection, desquamative gingivitis, and severe periodontitis. Histopathologic examination of the granular lesion on the right lateral border of the dorsum of the tongue showed well-differentiated squamous cell carcinoma. Etiopathogenesis, clinical features, and laboratory findings of this disease are discussed.

Adolescent↗
PubMed1993

Fracture of tooth by internal resorption: case report.

A case of extensive internal resorption of the left mandibular first premolar in a 24 year old man is reported. The case presented with slight discolouration and mobility of the tooth. On radiological examination extensive internal resorption and a fracture line at the cemento enamel region was observed, separating the crown and root. The case was treated endodontically after surgical removal of the fractured fragment of the crown.

Adult↗