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Biomedical subjects

Sassan Rezaie

Publications and source records attributed to Sassan Rezaie.

6 recordsLinked to original sources
PubMed2004

Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran.

BACKGROUND: Pityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins. METHODS: Differentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin. RESULTS: In pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%), followed by M. furfur (25.3%), M. sympodialis(9.3%), M. obtusa (8.1%) and M. slooffiae (4.0%). The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species. CONCLUSIONS: According to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered.

Adult↗
PubMed2004

Inhibitory effect of Aspergillus fumigatus extract on matrix metalloproteinases expression.

BACKGROUND: Matrix metalloproteinases (MMPs) play a role in several physiologic and pathologic events. There are some evidence indicating the involvement of MMPs in the pathophysiology of fungal infections. METHODS: Here we study somatic extract of Aspergillus fumigatus. The influence of Aspergillus vs. two other fungal extracts on MMPs production by Fibrosarcoma cell line was investigated using an in vitro cytotoxicity assay, sodium dodecyl sulfate-polyacrylamide and gelatin zymography. RESULTS: Comparative dose-dependent inhibitory effects on MMPs were seen by A. fumigatus extract and compared with some steroidal and non-steroidal drugs. Cytotoxicity analysis of our extract revealed much lower cell death than other examined agents. CONCLUSIONS: Since inhibition of MMPs activity has been employed in modality therapy in such diseases as cancer, this extract might be promising in the preparation of anti-MMP therapeutic derivatives.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Fluconazole downregulates metallothionein expression and increases copper cytotoxicity in Microsporum canis.

Azole antifungals are widely used to treat infections with dermatophyte fungi. Whereas it is well established that this class of drugs interferes with fungal ergosterol synthesis, little is known about its potential other biological effects. Here we report the isolation and structural organization of Microsporum canis metallothionein gene and demonstrate that fluconazole is able to downregulate the baseline as well as copper-induced expression of this gene. Since this effect occurred within 30 min after exposure of the fungus to fluconazole, it is unlikely that it is due to impaired ergosterol synthesis. Our additional demonstration that fluconazole enhances copper toxicity for M. canis suggests that inhibition of metallothionein expression by fluconazole is biologically relevant and may represent an important additional mode of the antifungal action of this drug. Therefore our data indicate that antifungal effects of azole derivatives might not only be due to interference with cell wall synthesis but may also affect other biological circuits within the fungal cells.

Amino Acid Sequence↗
PubMed2002

Differential expression of a novel gene in response to hsp27 and cell differentiation in human keratinocytes.

The 27 kDa heat shock protein (hsp27) is expressed in keratinocytes in a differentiation-related pattern. Keratinocyte differentiation involves a coordinated program of expression and interaction of specific differentiation-related genes and proteins. To investigate the functional role of hsp27 in these processes we used a differential display approach to identify genes that might be regulated by the expression of hsp27 in human keratinocytes. mRNA was extracted from the human squamous carcinoma cell line A431 and a subclone stably transfected with human hsp27. Reverse transcriptase differential display polymerase chain reaction was performed using one base anchored oligo-dT and arbitrary primers. Differentially expressed genes were confirmed by northern blot analysis and further characterized by sequencing. Their expression in human skin and other tissues was investigated by northern blot and in situ hybridization. Out of five fragments detected with the initial reverse transcriptase differential display polymerase chain reaction screen one could be confirmed by northern blot to be downregulated in hsp27-overexpressing A431. This mRNA (G24) is not only downregulated by overexpression of hsp27 in A431 but also during differentiation in normal human keratinocytes in culture and in situ, situations where hsp27 is known to be induced. According to sequence analysis G24 represents a novel gene that does not code for a protein and thus might belong to the growing family of noncoding RNAs. These results not only demonstrate for the first time that overexpression of hsp27 by gene transfer is associated with regulation of gene expression but also reveal a novel differentiation-associated gene in human keratinocytes.

Base Sequence↗
PubMedDate not supplied

Facial demodicosis.

A 24-year-old man presented with papulopustular, rosacea-like centro- facial lesions. Many Demodex mites were found in the affected area by microscopy of smears from pustules. This observation provides further evidence that demodicosis is a condition distinct from common rosacea. Considering clinical similarities of demodicosis, rosacea and some mycotic infections, direct examination to confirm the etiological agent is highly recommended prior to treatment.

Adult↗