Enhanced anti-tumor efficacy of 5-aminolevulinic acid-gold nanoparticles-mediated photodynamic therapy in cutaneous squamous cell carcinoma cells

The objective of this study was to investigate whether the conjugation of gold nanoparticles (GNPs) to 5-aminolevulinic acid (5-ALA) could enhance the anti-tumor efficiency of photodynamic therapy (PDT) in epidermoid carcinoma cells. The mRNA and protein expression levels were determined by quantitative real-time PCR and western blot, respectively. Cell viability, apoptosis, invasion, and migration were determined by MTT assay, flow cytometry, transwell invasion assay, and migration assay, respectively. Singlet oxygen generation was detected by the singlet oxygen sensor green reagent assay. Our results showed that PDT with 5-ALA and GNPs-conjugated 5-ALA (5-ALA-GNPs) significantly suppressed cell viability, increased cell apoptosis and singlet oxygen generation in both HaCat and A431 cells, and PDT with 5-ALA and 5-ALA-GNPs had more profound effects in A431 cells than that in HaCat cells. More importantly, 5-ALA-GNPs treatment potentiated the effects of PDT on cell viability, cell apoptosis, and singlet oxygen generation in A431 cells compared to 5-ALA treatment. Further in vitro assays showed that PDT with 5-ALA-GNPs significantly decreased expression of STAT3 and Bcl-2 and increased expression of Bax in A431 cells compared with PDT with 5-ALA. In addition, 5-ALA-GNPs treatment enhanced the inhibitory effects of PDT on cell invasion and migration and Wnt/β-catenin signaling activities in A431 cells compared to 5-ALA treatment. In conclusion, our results suggested that GNPs conjugated to 5-ALA significantly enhanced the anti-tumor efficacy of PDT in A431 cells, which may represent a better strategy to improve the outcomes of patients with cutaneous squamous cell carcinoma.

A case series pilot study on the combination of 5-aminolevulinic acid and photodynamic therapy (ALA-PDT) for treatment of vitiligo

Abstract: Background: To study the effective therapeutic concentration, drug application duration, irradiation duration and irradiation dosage of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) for treating vitiligo and observe its clinical efficacy. Objective: To assess the clinical efficacy of ALA-PDT for treating vitiligo. Methods: ALA with different drug concentrations, drug application durations, irradiation durations and irradiation dosages were adopted to treat skin lesions caused by vitiligo to determine the effective drug concentration, drug application duration, irradiation duration and irradiation dosage for treating three vitiligo volunteers and observe the therapeutic results. Results: The clinical trial suggested that ALA at a drug concentration of 1.5%, drug application duration for 3 hours, irradiation dosage of 80mw/cm2 and irradiation duration for 20 min was effective in treating vitiligo. Under these parameters, ALA-PDT was effective to the three vitiligo volunteers, with mild pain and feeling of burning but no other adverse reaction during treatment. Study limitations: Due to the small sample size in this study for the effectiveness of PDT in treating vitiligo and the potential variations in the efficacy for treating the disease at different areas, further studies shall be conducted for confirmation. Conclusions: ALA with a drug concentration at 1.5%, drug application duration for 3 hours, irradiation dosage of 80 mw/cm2 and irradiation duration for 20 min is effective in treating vitiligo. Therefore, ALA-PDT is safe and effective in treating the disease, with minor adverse events, providing a new method for treating vitiligo in the future.

Purification and production of the extracellular 5-aminolevulinate from recombiniant Escherichia coli expressing yeast ALAS / 生物工程学报

Aminolevulinic acid (ALA) is biosynthesized by the enzyme ALA synthase (ALAS). The ALA production has been studied using the overproducing ALAS from several bacteria in Escherchia coil, respectively. However, ALAS from eucaryote expressed in E. coli for producing ALA in the culture is not known. The extracellular ALA production and cell growth were investageted respectively using the recombinant E. coli overproducing Saccharomyces cerevisiae ALAS in shake-flask fermentations. The ALAS activity from the cell extract was assayed. The extracellular ALA was purified by the national-made large-dimension resins and confirmed by the capillary electrophoresis measurements. At 12h after induction at 37 degrees C, the extracellular ALA production was up to 162mg per liter LB culture at initial pH 6.5 with exogenous levulinate, succinate and and glycine at the concentration of 20 mmol/L respectively. The purity of ALA after purification is up to 90%.

Synthesis and evaluation of 4-substituted semicarbazones of levulinic acid for anticonvulsant activity / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity.</p><p><b>METHODS</b>All the compounds were evaluated for anticonvulsant activity. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) and subcutaneous metrazol (ScMet) induced seizure methods and minimal motor impairment was determined by rotorod test.</p><p><b>RESULTS</b>A majority of the compounds exhibited significant anticonvulsant activity after intraperitoneal administration. In the present study 4-(4'-fluoro phenyl) levulinic acid semicarbazone emerged as the most active molecule, showing broad spectrum of activity with low neurotoxicity. Unsubstituted levulinic acid semicarbazone was found to be inactive in all the screens.</p><p><b>CONCLUSION</b>The results obtained validate the hypothesis that presence of an aryl group near the semicarbazone moiety is essential for anticonvulsant activity. The results also indicate that the hydrophilic-hydrophobic site can accommodate hydrophilic groups.</p>

Prototipo de fuente lumínica pra terapia fotodinámica disenado en el Centro de Microscopía Electrónica / Prototype of light source for photodynmic therapy in Centre of Electron Mycroscopy

La Terapia Fotodinámica (PDT) es un tratamiento del cáncer basado en la acumulación específica de una droga fotosensible en el tejido maligno. Su posterior radiación con una longitud de onda apropiada, induce la producción de singuletes de oxígeno responsable de la peroxidación de las organelas y la muerte de las células neoplásicas. En el Centro de Microscopía Electrónica de la Universidad Nacional de Córdoba se diseñó y construyó un prototipo de fuente de irradiación no coherente de 630nm el que posibilitó la aplicación de PDT por primera vez en nuestro país. Este prototipo ha sido aplicado satisfactoriamente en el tratamiento de la queratosis actínica. Fueron tratadas 100 lesiones en 27 pacientes utilizando como fotosensibilizador al ácido d amino levulínico (ALA) al 20 por ciento La activación lumínica duró de 5 a 20 minutos dependiendo de la extensión y profundidad de la lesión. Los resultados obtenidos fueron los siguientes: Remisión Completa de las lesiones (RC) 84por ciento, Remisión parcial (RP) 10 por ciento, Sin respuesta (SR) 0 por ciento y Sin datos (SD) 6 por ciento. En el último grupo están incluidos aquellos pacientes que no retornaron para su evaluación. La alta efectividad, sumada a la inmejorable respuesta cosmética y la reducida agresividad, hacen de PDT el método de elección en el tratamiento de esta patología. El prototipo utilizado en este estudio demostró ser además de no invasivo y bien tolerado, altamente efectivo.

Multicollinearity may lead to artificial interaction: an example from a cross sectional study of biomarkers.

Collinearity is the situation which arises in multiple regression when some or all of the explanatory variables are so highly correlated with one another that it becomes very difficult, if not impossible, to disentangle their influences and obtain a reasonably precise estimate of their effects. Suppressor variable is one of the extreme situations of collinearity that one variable can substantially increase the multiple correlation when combined with a variable that is only modestly correlated with the response variable. In this study, we describe the process by which we disentangled and discovered multicollinearity and its consequences, namely artificial interaction, using the data from cross-sectional quantification of several biomarkers. We showed how the collinearity between one biomarker (blood lead level) and another (urinary trans, trans-muconic acid) and their interaction (blood lead level* urinary trans, trans-muconic acid) can lead to the observed artificial interaction on the third biomarker (urinary 5-aminolevulinic acid).

Clinical presentation of patients with acute intermittent porphyria-our experience with 12 patients

Acute Intermittent Porphyria [AIP] presents as acute abdomen and implicates emergency and injudicious surgery. A clinical profile of AIP has been studied in 12 patients in order to raise a high suspicion index so that injudicious surgery is avoided. The study shows that the cases fell in 2nd and 3rd decade with a male preponderance of 11:1. Abdominal pain, tachycardia, hypertension and neuropsychiatric manifestationns were found in almost all the cases. Four out of 12 patients had underwent surgery as [acute abdomen] and three died with septicaemia. Three fourth of the cases belonged to Baiochistan