Validation of PCR based detection system for aflatoxin producing molds.

Aflatoxins are polyketide secondary metabolites that are produced by certain fungal species in the Aspergillus section Flavi, particularly Aspergillus flavus and Aspergillus parasiticus which contaminate human food as well as animal feed. These are among the most carcinogenic substances known. Due to the toxic and carcinogenic properties of aflatoxins, there is a need to develop reliable methods to detect the presence of aflatoxigenic Aspergilli in contaminated food and feed. Not all Aspergillus strains are able to produce aflatoxins. It requires a detection methodology which can specifically distinguish between the aflatoxin producing and nonproducing strains of Aspergillus. Present communication reports validation of a PCR based detection system based on three genes viz., nor-1, apa-2 and omt-1 involved in aflatoxin biosynthesis, that can specifically distinguish the two aflatoxin producing species viz. Aspergillus flavus ,and Aspergillus parasiticus from non-producers i.e., A. niger, A. fumigates and A. oryzae.

Exploratory analysis of clinical benefit of ipilimumab and nivolumab treatment in patients with metastatic melanoma from a single institution.

PURPOSE: We retrospectively analysed overall survival (OS) and potential predictive biomarkers of OS in patients with metastatic melanoma treated with ipilimumab plus nivolumab in a single institution. METHODS AND PATIENTS: Electronic medical records of patients with advanced melanoma receiving ≥ 1 dose of a combined ipilimumab plus nivolumab regimen between March 3, 2016 and March 7, 2020 in a single institution, were reviewed. OS was analysed using the Kaplan-Meier method. Sub-group analyses were conducted to examine several endpoints according to relevant clinical, molecular and pathological variables using logistic and Cox models. RESULTS: Forty-four cases were reviewed, 38 (86.4%), of whom had cutaneous melanoma, 21 (47.7%) were BRAF mutant, 21 (47.7%) presented high lactate dehydrogenase (LDH) values, 23 (52.3%) had ≥ 3 disease sites, and 10 (22.7%) patients had brain metastases. The median follow-up was 37.7 months, and the median OS was 21.1 months (95% CI 8.2-NR). In the multivariate analysis, the OS was significantly longer in patients with an Eastern Cooperative Oncology Group (ECOG) score of 0, LDH ≤ upper limit of normal, absence of liver metastases and neutrophil-to-lymphocyte ratio (NLR) < 5 (all p ≤ 0.05, log-rank test). These factors allowed the classification of patients into three prognostic risk groups (low/intermediate/high risk) for death. CONCLUSION: Overall survival of real-world patients from our cohort receiving ipilimumab plus nivolumab was lower than in previous studies. The ECOG score, LDH values, the presence of liver metastases and the NLR were independent prognostic factors for survival.

SILENT MYOCARDIAL ISCHEMIA IN HEMODIALYSIS PATIENTS - FACTOR FICTION?

Thirty eight patients underwent Holter ECG monitoring for a 48 hour period covering dialysis and intermediate period to detect incidence of myocardial ischemia manifesting as ST segment changes. Seventeen patients (44.7%) had 165 episodes of dynamic ST segment changes lasting from 1 to 177 minutes, with maximum ST depression of 4 mm. The mean age of patients was 45 ± 14 years and 14 (82.6%) of them were males. Ten (58.8%) patients had hypertension, and 5 (29.4%) patients each had diabetes mellitus and pre-existing coronary artery disease. Six (35.3%) patients with dynamic ST segment changes had ventricular ectopics ranging from isolated ventricular premature contractions to episodes of ventricular tachycardia. No significant hypotension or angina was documented during these episodes of ST segment deviation. We concluded that hemodialysis plays an important role in the genesis of the above ECG changes.

Enhanced cellulase producing mutants developed from heterokaryotic Aspergillus strain.

A heterokaryon 28, derived through protoplast fusion between Aspergillus nidulans and Aspergillus tubingensis (Dal8), was subjected cyclic mutagenesis followed by selection on increasing levels of 2-deoxy glucose (2-DG) as selection marker. The derived deregulated cellulase hyper producing mutant '64', when compared to fusant 28, produced 9.83, 7.8, 3.2, 4.2 and 19.74 folds higher endoglucanase, ß-glucosidase, cellobiohydrolase, FPase and xylanase, respectively, under shake cultures. The sequence analysis of PCR amplified ß-glucosidase gene from wild and mutant showed nucleotide deletion/substitution. The mutants showed highly catalytic efficient ß-glucosidase as evident from low Km and high Vmax values. The expression profiling through zymogram analysis also indicated towards over-expression of cellulases. The up/down regulated expressed proteins observed through SDS-PAGE were identified by Peptide mass fingerprinting The cellulase produced by mutants in conjunction with cellulase free xylanase derived from Thermomyces lanuginosus was used for efficient utilization of alkali treated rice straw for obtaining xylo-oligosaccharides and ethanol.

Proteome-based profiling of hypercellulase-producing strains developed through interspecific protoplast fusion between Aspergillus nidulans and Aspergillus tubingensis.

Thirty heterokaryons, formed by protoplast fusion of Aspergillus nidulans and Aspergillus tubingensis, were selected on the basis of their ability to grow on 2-deoxyglucose (0.2 %, w/v) and intermediate spore color. These heterokaryons were studied for cellulase production using shake flask and solid substrate cultures at 40 °C. Fusants 51 and 28 exhibited appreciably higher levels of endoglucanase, cellobiohydrolase, ß-glucosidase, and FPase activities when compared with parental strains. Employing proteomic-based approaches, the differential expression of proteins in secretome of fusants and parental strains were analyzed using two-dimensional electrophoresis. The expression of some of the proteins in the fusants was found to be up/downregulated. The upregulated proteins in the fusant 51 were identified by liquid chromatography-mass spectroscopy as endoxylanase, endochitinase, ß-glucosidase, as well as hypothetical proteins. The cellulases produced by fusants 28 and 51 showed improved saccharification of alkali treated rice straw when compared with the parental strains.