Understanding the role of uncharacterized and hypothetical pathogenicity genes of Colletotrichum orbiculare to oxidative stress and phenolics of cucumber plant in anthracnose development

Uncharacterized and hypothetical pathogenicity genes of Colletotrichum orbiculare inciting anthracnose of cucumber are poorly annotated but could be potential antifungal targets in anthracnose control. Hence, to associate them with specific functions in fungal–host interactions for exploitation in anthracnose control, their responses to reactive oxygen species produced due to oxidative burst and constitutive or induced phenolics, the earliest known defence mechanisms of host plants were assessed. Among commercially available related phenolic compounds, at the lowest concentration of 1 mM, ferulic and chlorogenic acids were less toxic to the pathogen. Among the phenolics, a less significant expression of superoxide dismutase coupled with a strong expression of catalase in ferulic acid greater than that in menadione and hydrogen peroxide, respectively indicated its oxidative effect through generation of radicles similar to that of hydrogen peroxide. However, lack of expression of beta-ketoadipate pathway genes in response to the phenolic acids indicated the role of other phenol metabolizing genes of the pathogen. In planta expression followed by constitutive expression of uncharacterized and hypothetical pathogenicity genes of C. orbiculare in a minimal medium indicated that 6 of the genes are not redundant and may function under stress conditions. Among the genes, significant expression of ENH87556 in menadione (1.3-fold) together with a weak expression in hydrogen peroxide in relation to untreated control indicated its role in oxidative stress generated due to the superoxide radical of menadione. Additionally, a strong expression (3.8-fold) of the gene in ferulic acid greater than that of either control, minimal medium or minimal medium with leaf extract indicated its role in phenol metabolism. Thus, the gene could be a potential molecular target for anthracnose control upon validation by functional analysis.

Surgical outcome of tragal cartilage in myringoplasty A prospective study

Background: Tympanoplasty refers to any operation involving reconstruction of the tympanic membrane and/or the ossicular chain. Myringoplasty is a Tympanoplasty without ossicular reconstruction. Chronic otitis media is one of the commonest Otological problems among Sudanese, in both adult and children (43%) and they presented with perforation of the eardrum and different degrees of hearing loss. Aim: To evaluate the audiological and surgical results of tragal cartilage graft in myringoplasty for reconstruction of tympanic membrane perforation. Materials and methods: A total of 25 patients in the age group of 16 - 60 years suffering from chronic suppurative otitis media of tubotympanic type, attending the outpatient department at Rajah Muthiah Medical College and hospital and underwent tragal cartilage myringoplasty between October 2015 to August 2017 were included in the study. Results: The mean preoperative pure tone average was 37 and the postoperative pure tone average was 25.80 at 6th week and 15.60 at 10th week. The calculated p-value was less than 0.001 which was statistically significant. Graft uptake was 92% in our study. There was no postoperative retraction. Postoperative reperforation was seen in 2 (8%) patients. Conclusion: Graft takeup in tragal cartilage myringoplasty has been excellent, hearing results are satisfactory and complications are minimal. Immobility of the transplant during the early stages of the healing process is the most important factor for the successful surgical outcome of myringoplasty.

Odynophagia following retained bee stinger

Nearly half of Hymenoptera stings affect the head and neck region of victims, but reports on oropharyngeal bee stings are very few. We describe the case of a patient with odynophagia and suffocation in mass envenomation. He had a retained bee stinger whose removal was delayed for more than 24 hours following the sting, due to persisting angioedema. Odynophagia receded after removal of the stinger and treatment with paracetamol, steroids and metronidazole. The patient also developed rhabdomyolysis, renal failure and hepatitis that were treated with conservative therapy. Oropharyngeal stings can simulate symptoms of persisting angioedema in victims of mass envenomation.(AU)

n-Propanol as a substrate for assaying the ligninperoxidase activity of Phanerochaete chrysoporium.

The steady state kinetics of ligninperoxidase catalysed reaction using n-propanol as the organic substrate and monitoring the formation of propanaldehyde at lambda = 300 nm spectrophotometerically as functions of different reaction parameters has been studied. It has been concluded that n-propanol can be used as a substrate for analysing the activity of ligninperoxidase. The turnover number of ligninperoxidase of Phanerochaete chrysosporium using n-propanol as substrate has been found to be higher approximately by a factor of 10(3) as compared to that using veratryl alcohol as the substrate. The method works in assaying the activity of ligninperoxidase produced by Aspergillus fumigatus indicating that it can be used for assaying the ligninperoxidase activities produced by other microorganisms also and is not limited to assaying the ligninase activity produced by Phanerochaete chrysosporium alone. Under identical experimental conditions, horseradish peroxidase does not show peroxidase activity using n-propanol as substrate indicating that the method does not interfere with the activities of other peroxidases.

Extracellular production of alpha-rhamnosidase by Rhizopus nigricans.

Extracellular production of alpha-rhamnosidase [EC 3.2.1.40] from an indigeneous fungal strain of R. nigricans has been demonstrated. The enzyme has been shown to follow Michaelis-Menten kinetics using p-nitrophenyl-alpha-L-rhamnopyranosid as a substrate. The pH and the temperature optima of the enzyme have been found to be around 6.5 and 60 degrees-80 degrees C respectively.