l-Arginine deiminase (ADI) has a powerful anticancer activity against various tumors, via arginine depletion, arresting the cell cycle at G1 phase. However, the current clinically tried bacterial ADI displayed a higher antigenicity and lower thermal stability. Thus, our objective was to purify and characterize this enzyme from thermophilic fungi, to explore its catalytic and antigenic properties for therapeutic uses. ADI was purified from thermophilic Aspergillus fumigatus KJ434941 to its electrophoretic homogeneity by 5.1-fold, with molecular subunit 50 kDa. The purified ADI was PEGylated and covalently immobilized on dextran to explore its catalytic properties. The specific activity of free ADI, PEG-ADI, and Dex-ADI was 26.7, 21.5, and 18.0 U/mg, respectively. At 50°C, PEG-ADI displays twofold resistance to thermal denaturation (t1/2 13.9 h), than free ADI (t1/2 6.9 h), while at 70°C, the thermal stability of PEG-ADI was increased by 1.7-fold, with similar stability to Dex-ADI with the free one. Kinetically, free ADI had the higher catalytic affinity to arginine, followed by PEG-ADI and Dex-ADI. Upon proteolysis for 30 min, the residual activity of native ADI, PEG-ADI, and Dex-AD was 8.0, 32.0, and 20.0% for proteinase K and 10.0, 52.0, and 90.0% for acid protease, respectively. The anticancer activity of the ADIs was assessed against HCT, HEP-G2, and MCF7, in vitro. The free and PEG-ADI exhibits a similar cytotoxic efficacy for the tested cells, lower than Dex-ADI. The free ADI had IC50 value 22.0, 16.6, and 13.9 U/mL, while Dex-ADI had 3.98, 5.18, and 4.43 U/mL for HCT, MCF7, and HEPG-2, respectively. The in vitro anticancer activity of ADI against HCT, MCF7, and HEPG-2 was increased by five-, three-, and threefold upon covalent modification by dextran. The biochemical and hematological parameters of the experimented animals were not affected by ADIs dosing, with no signs of anti-ADI immunoglobulins in vivo. The in vivo half-life time of free ADI, PEG-ADI, and Dex-ADI was 29.7, 91.1, 59.6 h, respectively. The present findings explored a novel thermostable, less antigenic ADI from thermophilic A. fumigatus, with further molecular and crystallographic analyses, this enzyme will be a powerful candidate for clinical trials.
To evaluate the possible association of Parkinson disease (PD) and melanoma in North America. Design, Setting, and Patients: Thirty-one centers enrolled patients with idiopathic PD. At visit 1, a neurologist obtained a medical history. At visit 2, a dermatologist recorded melanoma risk factors, performed a whole-body examination, and performed a biopsy of lesions suggestive of melanoma for evaluation by a central dermatopathology laboratory. We compared overall prevalence of melanoma with prevalence calculated from the US Surveillance Epidemiology and End Results (SEER) cancer database and the American Academy of Dermatology skin cancer screening programs. Results: A total of 2106 patients (mean [SD] age, 68.6 [10.6] years; duration of PD, 7.1 [5.7] years) completed the study. Most (84.8%) had received levodopa. Dermatology examinations revealed 346 pigmented lesions; der-matopathological findings confirmed 20 in situ melanomas (0.9%) and 4 invasive melanomas (0.2%). In addition, histories revealed 68 prior melanomas (3.2%). Prevalence (5-year limited duration) of invasive malignant melanoma in the US cohort of patients with PD (n=1692) was 2.24-fold higher (95% confidence interval, 1.21-4.17) than expected in age-and sex-matched populations in the US SEER database. Age-or sex-adjusted relative risk of any melanoma for US patients was more than 7 times that expected from confirmed cases in American Academy of Dermatology skin cancer screening programs. Conclusions: Melanoma prevalence appears to be higher in patients with PD than in the general population. Despite difficulties in comparing other databases with this study population, the study supports increased melanoma screening in patients with PD.
Lactic acid bacteria (LAB) are widely known for their probiotic activities for centuries. These bacteria synthesise some secretory proteinaceous toxins, bacteriocins, which help destroy similar or interrelated bacterial strains. This study was aimed at characterising bacteriocins extracted from Lactobacillus spp. found in yoghurt and assessing their bactericidal effect on foodborne bacteria. Twelve isolated Lactobacillus spp. were examined to produce bacteriocins by the organic solvent extraction method. Bacteriocins produced by two of these strains, Lactobacillus helveticus (BLh) and Lactobacillus plantarum (BLp), showed the most significant antimicrobial activity, especially against Staphylococcus aureus and Acinetobacter baumannii. Analysis of SDS-PAGE showed that L. plantarum and L. helveticus bacteriocins have a molecular weight of ~10 kDa and ~15 kDa, respectively. L. plantarum (BLp) bacteriocin was heat stable while L. helveticus (BLh) bacteriocin was heat labile. Both bacteriocins have shown activity at acidic pH. Exposure to a UV light enhances the activity of the BLh; however, it had negligible effects on the BLp. Different proteolytic enzymes confirmed the proteinaceous nature of both the bacteriocins. From this study, it was concluded that bacteriocin extracts from L. helveticus (BLh) can be considered a preferable candidate against foodborne pathogens as compared to L. plantarum (BLp). These partially purified bacteriocins should be further processed to attain purified product that could be useful for food spoilage and preservation purposes.
A series of 115 patients was treated with sodium valproate (Epilim) for periods ranging from 6 to 24 months and in dosages ranging from 400 mg to 2400 mg daily. All but six of these patients had intractable epilepsies and had been previously treated unsuccessfully with other anti-epileptic agents. Eighty patients had generalised seizures and 35 had partial seizures which, in 26 cases, were secondarily generalised. Reduction of seizure frequency by over 50 per cent occurred in about 70 per cent of patients with generalised seizures but in only 37 per cent of those with partial seizures. A number of patients reported increased alertness, improvement of mood, increased appetite and improved performance at school. The adverse effects encountered were gastro-intestinal symptoms, weight gain and hair loss.
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