Discrimination of normal and cancerous human skin tissues based on laser-induced spectral shift fluorescence microscopy.

A homemade spectral shift fluorescence microscope (SSFM) is coupled with a spectrometer to record the spectral images of specimens based on the emission wavelength. Here a reliable diagnosis of neoplasia is achieved according to the spectral fluorescence properties of ex-vivo skin tissues after rhodamine6G (Rd6G) staining. It is shown that certain spectral shifts occur for nonmelanoma/melanoma lesions against normal/benign nevus, leading to spectral micrographs. In fact, there is a strong correlation between the emission wavelength and the sort of skin lesions, mainly due to the Rd6G interaction with the mitochondria of cancerous cells. The normal tissues generally enjoy a significant red shift regarding the laser line (37 nm). Conversely, plenty of fluorophores are conjugated to unhealthy cells giving rise to a relative blue shift i.e., typically SCC (6 nm), BCC (14 nm), and melanoma (19 nm) against healthy tissues. In other words, the redshift takes place with respect to the excitation wavelength i.e., melanoma (18 nm), BCC (23 nm), and SCC (31 nm) with respect to the laser line. Consequently, three data sets are available in the form of micrographs, addressing pixel-by-pixel signal intensity, emission wavelength, and fluorophore concentration of specimens for prompt diagnosis.

Fluorescence emission quenching of RdB fluorophores in attendance of various blood type RBCs based on Stern-Volmer formalism.

In this work, the optical properties of Rhodamine B (RdB) are investigated in the attendance of various red blood cells (RBCs). RdB fluorophores, as biological markers, is excited using SHG-CW Nd:YAG laser at 532 nm. In fact, the addition of biomolecules of interest to the reference fluorophore notably changes the fluorescence properties of the suspension. Here, laser induced fluorescence (LIF) spectrophotometry based on Stern-Volmer quenching formalism and field emission scanning electron microscope (FESEM) are employed here. According to the given fluorescence spectra, the spectral shift of emissions as well as quenching coefficients are assessed subsequently. The Stern-Volmer formalism is used to determine the quenching coefficients. In fact, RdB + RBCs suspensions contain a plenty of bioconjugates leading to the signal reduction and notable red shift in RdB fluorescence emissions. Furthermore, it is demonstrated that the positive blood type RBCs exhibit the higher quenching coefficients and the larger red shifts against those of negative blood types. This mainly arises from the nature of specific sugar antigens available on the RBC membranes as to N-acetylgalactosamine and galactose attached to the O-antigen terminal would enhance further quenching of the species. Moreover, a significant correlation appears between Stern-Volmer coefficients and the corresponding RBCs. In fact, distinct discrepancy takes place in quenching coefficients in terms various positive/negative blood types to envisage a facile method of blood typing.

Fluorescence properties of Phycocyanin and Phycocyanin-human serum albumin complex.

In this work, the fluorescence properties of Phycocyanin (PC) and the corresponding quenching effects are investigated in attendance of human serum albumin (HSA). At first, PC is excited at 532 nm using CW SHG Nd:YAG laser, then the emission wavelength, Stokes shift, quantum yield, extinction constant and self-quenching coefficient are obtained based on the modified Beer-Lambert equation. It is shown that a notable red shift appears in terms of PC concentration. According to the fluorescence spectra, the addition of HSA in PC solution leads to a significant reduction in the fluorescence signal via quenching events, however a lucid blue shift takes place in the same time. Stern-Volmer formalism is used to determine the quenching constant (KS), the number of binding sites (n) between PC and HSA as well as the association constant Ka for the purpose of facile transportation to the target in the context of drug delivery. Eventually, temperature dependent coefficients and corresponding spectral shifts are investigated over a wide range of temperatures at a couple of distinct PC concentrations to attest the dominant static quenching takes place. The rate of conjugate formations elevates at low temperatures leading to a certain blue shift. Furthermore, large KS is measured in the course of signal reduction, particularly at low PC populations. In fact, PC conjugation to HSA is essential interaction to enhance chemo drug transportation. Here, at the body temperature, the quenching coefficient decreases to facilitate the drug release. Moreover, the spectral shift of fluorescence emission can be useful for simultaneous monitoring and drug delivery treatment.

The correlation between Pax5 deletion and patients survival in Iranian children with precursor B-cell acute lymphocytic leukemia.

Despite advances in treatment, children with acute lymphoblastic leukemia (ALL) still experience drug resistance and relapse. Several gene mutations are involved in the onset of this disease and resistance to therapy. The present study examines the incidence of IKZF1, CDKN2A/B, PAX5, EBF1, ETV6, BTG1, RB1, JAK2, and Xp22.33 gene deletions/duplications associated with pediatric ALL in Iran and investigates the possible effect of these mutations on drug resistance. Three-year disease-free survival (3DFS) was evaluated for children diagnosed with Philadelphia negative precursor-B-cell ALL hospitalized at Sayed-al-Shohada Hospital, Isfahan-Iran, from January 2009 until December 2012. DNA was extracted from bone marrow slides, and ALL correlated gene deletions and duplications were measured using Multiplex Ligation-dependent Probe Amplification (MLPA) method. The correlation between gene mutations and 3DFS was then assessed. Among the nine aforementioned investigated genes, 63% of samples showed at least one gene mutation. At least two concomitant genomic mutations were observed in 42% of samples. Pax5 deletion was the most prevalent gene mutation observed in 45% of cases, and showed significant negative impact on response to treatment. CDKN2A/B (9p21.3) gene deletion, and ETV6 (12p13.2) gene duplication also demonstrated negative effect on patient survival and contributed to a worse prognosis if concomitant with Pax5 gene deletion. ALL patients with one of the gene deletions including Pax5  and CDKN2A/B (9p21.3) or ETV6 (12p13.2) gene duplication are classified as high-risk patients and need more intensified protocols of treatment to improve their chance of survival.

In vitro activity of kombucha tea ethyl acetate fraction against Malassezia species isolated from seborrhoeic dermatitis.

BACKGROUND AND PURPOSE: Seborrheic dermatitis is a chronic and recurrent superficial dermatitis in which Malassezia species play an important role. There are different Malassezia species, which have been recently reported to be resistant to common antifungals. Natural sources can be useful alternatives to reduce the emergence of this resistance. Kombucha tea is believed to have potential antimicrobial properties. Regarding this, the present study aimed to investigate the antifungal activity of Kombucha tea ethyl acetate fraction (KEAF) against Malassezia species obtained from the patients with seborrheic dermatitis. MATERIALS AND METHODS: A total of 23 clinical isolates were identified by direct microscopic examination and Tween assimilation, and then confirmed by DNA sequencing of ITS regions for Malassezia species. Kombucha tea was fractionated using ethyl acetate (1:2 v/v). The minimum inhibitory concentration (MIC) microdilution assay was used to evaluate the anti-Malssezia activity of KEAF at three concentrations of 10, 40, and 80 mg/mL. RESULTS: The results of the DNA sequence analysis indicated that M. furfur (39.13%) was the predominant species, followed by M. globosa (30.43%), M. sloofie (13.04%), M. sympodialis (13.04%), and M. restricta (4.34%), respectively. Furthermore, KEAF showed inhibitory activity against Malassezia species. Accordingly, KEAF had the lowest and highest MIC value against M. sloofie and M. restricta, respectively. Moreover, the inhibitory effect of the extract was equivalent to that of ketoconazole at 4.8 µg/mL. CONCLUSION: The findings of the current study highlighted the antifungal properties of KEAF. Therefore, this extract can be promoted as complementary medicine for the treatment of the infections caused by Malassezia.

The role of ATP-binding cassette transporter A2 in childhood acute lymphoblastic leukemia multidrug resistance.

Acute lymphoblastic leukemia (ALL) is one of the most prevalent hematologic malignancies in children. Although the cure rate of ALL has improved over the past decades, the most important reason for ALL treatment failure is multidrug resistance (MDR) phenomenon. The current study aims to explain the mechanisms involved in multidrug resistance of childhood ALL, and introduces ATP-binding cassette transporterA2 (ABCA2) as an ABC transporter gene which may have a high impact on MDR. Benefiting from articles published inreputable journals from1994 to date and experiments newly performed by our group, a comprehensive review is written about ABCA2 and its role in MDR regarding childhood ALL. ABCA2 transports drugs from the cytoplasm into the lysosomal compartment, where they may become degraded and exported from the cell. The aforementioned mechanism may contribute to MDR. It has been reported that ABCA2 may induce resistance to mitoxantrone, estrogen derivatives and estramustine. It is resistant to the aforementioned compounds. Furthermore, the overexpression ofABCA2 in methotrexate, vinblastine and/or doxorubicin treated Jurkat cells are observed in several publications. The recent study of our group showsthatthe overexpression ofABCA2 gene in children with ALL increases the risk of MDR by 15 times. ABCA2 is the second identified member of the ABCA; ABC transporters' subfamily. ABCA2 gene expression profile is suggested to be an unfavorable prognostic factor in ALL treatment. Better understanding of the MDR mechanisms and the factors involved may improve the therapeutic outcome of ALL by modifying the treatment protocols.

Beta s gene in Central Iran is in linkage disequilibrium with the Indian-Arab haplotype.

Sickle cell anemia is not considered to be a significant disease in Iran, although the sickle cell trait is estimated to have a high incidence in the Southern provinces. Since 1977, when the presence of a mild sickle cell anemia was reported in this country, there have been no further investigations published giving precise data on the incidence and origins of the sickle cell mutation in Iran. We report here the finding of patients with the sickle cell trait, sickle cell anemia, and sickle-beta thalassemia in Central Iran. A survey of 300 individuals from a village in Southeast Esfahan revealed an incidence of the sickle cell trait of 8.33%. "Cascade screening" enabled 96 relatives in four surrounding villages to be tested, and the at-risk couples were offered counseling as a "sickle cell control program." The hematological indices and HbF levels of the affected patients were determined. The HbF levels were unusually high, ranging from 18% to 41.4%, and SS patients with the highest levels were asymptomatic. Linkage analysis revealed the betaS gene haplotype in this population to be the Indian-Arab haplotype.