International Journal of Medicine and Medical Sciences

International Journal of Medicine and Medical Sciences ISSN 2167-0404 Vol. 10 (6), pp. 001-006, June, 2020. © International Scholars Journals

Full Length Research Paper

Study of sensitivity and ability of adenosine deaminase in response to pre-unfolding and especially pathological temperatures via changing the enzyme structure and activity

Mostafa Rezaei-Tavirani^1,2*, Saeed Hesami-Takallu³, Seyed Hassan Moghaddamnia¹, Shiva Kalantari⁴, Bijan Ranjbar⁵, Seyedeh Zahra Moosavi-Nejad⁶, Sayed-Amir Marashi⁷, Mohammad Rahmati Roodsari² and Farhad Malekzad²

¹Clinical Proteomics Research Center, Faculty of Paramedical Sciences, Shahid Beheshti University (M.C.), Tehran, Iran.

²Skin Research Center, Shahid Beheshti University (M.C.), Tehran, Iran.

³Science and Researches Branch, Islamic Azad University, Tehran, Iran.

⁴Asre-Novin Institute of Research and Industrial Services, Unit 12, No. 38 (Malek Building), Tajrish Sq., Fana-Khosro Ave., Tehran, Iran.

⁵Department of Biophysics, Faculty of Science, Tarbiat Modarres University, Tehran, Iran.

⁶Department of Biology, Faculty of Science, Alzahra University, Tehran, Iran.

⁷IMPRS-CBSC, Max Planck Institute for Molecular Genetics, Berlin, Germany.

Accepted 26 April, 2020

Abstract

Adenosine deaminase (ADA) is an important enzyme of the purine metabolic pathway, which catalyzes the conversion of adenosine and deoxyadenosine to their respective inosine derivatives plus ammonia, in a rapid and irreversible reaction. In this work, we studied the structural and kinetic properties of bovine ADA as a function of temperature in the range, 20 - 80°C by circular dichroism (CD) and UV-spectrophotometric techniques, as well as by measuring its activity in this temperature range. The results suggest that thermal unfolding of ADA occurs at temperatures above 60°C, while the enzyme undergoes detectable conformational changes during pre-unfolding heating. These changes affect the kinetics of reaction catalyzed by ADA. The relation between enzyme activity and structural changes is discussed.

Key words: Adenosine deaminase (ADA), UV-Vis spectrophotometry, Conformational changes, Circular dichroism (CD), Kinetic study.

International Journal of Medicine and Medical Sciences ISSN 2167-0404 Vol. 10 (6), pp. 001-008, June, 2020. © International Scholars Journals

Full Length Research Paper

Two-stage anaerobic digestion of aerobic pre-treated sisal leaf decortications residues: hydrolases activities and biogas production profile

Anthony Manoni Mshandete¹*, Lovisa Björnsson², Amelia Kajumulo Kivaisi¹, Mugassa Steven Thomas Rubindamayugi¹ and Bo Mattiasson²

¹Department of Molecular Biology and Biotechnology, University of Dar es Salaam. P. O. Box 35179, Dar es Salaam Tanzania.

²Department of Biotechnology, Centre for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, SE-22100, Lund, Sweden.

Accepted 24 May, 2020

Abstract

A two-stage system was investigated for anaerobic digestion (AD) of aerobically pre-treated sisal leaf decortication residue (SLDR) with regard to hydrolytic enzymes and biogas production. The system consisted of a solid-bed bioreactor for hydrolysis connected to methanogenic bioreactor packed with sisal fibre decortication residues (SFDR) as biofilm carriers. Some of the enzymes produced by microorganisms to hydrolyse SLDR were found to be pectinase, filter paper cellulase, amylase, - glucosidase, carboxylmethyl cellulase, xylanase and protease. Enzyme activities observed in the acidogenic bioreactor were much higher than those in the methanogenic bioreactor. The hydrolysis and the methanogenic stages were well separated, as indicated by the high carbon dioxide production, high volatile fatty acids (VFAs) concentration and low pH in the acidogenic bioreactor compared with high methane production, low VFAs concentration and above neutral pH in the effluent of the methanogenic bioreactor. Digestion of SLDR gave energy yields of 2.45 kWh/kg volatile solids added in the form of methane. The integrity of the methane filter was maintained throughout the period of operation producing biogas with 51 - 70% methane content. A stable effluent pH showed that the methanogenic bioreactor had good ability to withstand the variations in load and VFAs concentrations that occurred in the two- stage process. In conclusion, the results of this study showed that the two-stage system was suitable for effective stabilization and biomethanation of SLDR.

Key words: Anaerobic digestion, two-stage, sisal decortications residues, aerobic pre-treatment, biogas, hydrolases.

International Journal of Medicine and Medical Sciences ISSN 2167-0404 Vol. 10 (6), pp. 001-007, June, 2020. © International Scholars Journals

Full Length Research Paper

Lipid peroxidation and tyrosinase inhibition by lichen symbionts grown in vitro

Neeraj Verma, Bhaskar C. Behera*, Anjali Sonone and Urmila Makhija

Plant Science Division, Agharkar Research Institute, G.G. Agarkar Road, Pune- 411 004, India

Accepted 25 April, 2020

Abstract

The symbionts of lichen species Arthothelium awasthii, Heterodermia podocarpa, and Parmotrema tinctorum were isolated and cultured on various nutrient media incubated in a growth chamber. Methanolic extracts of one year old symbiont cultures were taken for evaluating their potential to inhibit lipid peroxidation and tyrosinase enzyme activity. The extracts of all cultured lichen-symbionts have shown a concentration-time dependent inhibition of lipid peroxidation and tyrosinase activities. IC₅₀ values for inhibition of lipid peroxidation by culture-extracts were 15.7 µg for A. awasthii, 12.68 µg for H. podocarpa and 11.47 µg for P. tinctorum. Testing the impact of the extracts on tyrosinase activity, we found IC₅₀ of 8.71 µg (A. awasthii), 14.55 µg (H. podocarpa) and 12.44 µg (P. tinctorum). According to their IC₅₀ the tested extracts turned out to be more effective for the tested parameters than the standard antioxidant Trolox (IC₅₀ for lipid peroxidation 16.13 µg) and Kojic acid tyrosinase inhibitor (IC₅₀ for tyrosinase inhibition 17.63 µg). The results suggest possible applications of lichen substances in the extracts of A. awasthii, H. podocarpa, and P. tinctorum symbionts as natural tyrosinase inhibitors.

Keyword: Lichen culture, Tyrosinase inhibition

International Journal of Medicine and Medical Sciences ISSN 2167-0404  Vol. 10 (4), pp. 001-005, April, 2020. © International Scholars Journals

Full Length Research Paper

A study on assessing the risk factors, outcomes and antimicrobial sensitivity patterns of surgical site infections

Siva Reddy, D.O Rao and P.A Kini

Department of Paediatric Surgery, Andhra Medical College, Visakhapatnam, Andhra Pradesh, India.

Accepted 22 May, 2019

Abstract

A prospective study was carried out on 1125 surgeries for the incidence of surgical site infections (SSIs). The etiologic agent was isolated, identified and the antibiotic susceptibility pattern was determined using standard methods. The risk associated with SSIs was assessed by multivariate regression logistic analysis. A case-control study was carried out for the outcome of SSIs. The outcomes measured were: length of intensive care unit (ICU) stay (in days), length of ward stay (in days), costs incurred (in rupees) by the patient, and mortality rate. The results indicated that 12% of patients undergoing surgery developed SSI. Staphylococcus aureus (33%) and Enterococcus spp. (33%) were the commonest etiologic agents. Patients with SSIs had a significantly extended ICU and ward stay (p<0.001), and incurred higher hospital costs (p<0.001) when compared to those who did not develop SSIs. The mortality rate was high in patients who developed SSIs. The risk factors associated with SSIs were age above 45 years (p=0.012), female (p=0.070), diabetic status (p<0.001) and surgeries such as gastrectomy, prostatectomy, hysterectomy, cholecystectomy and appendectomy. Surgical site wound infection, though preventable, still remains as high as 12%. Determining the antimicrobial patterns of the organisms causing SSIs will enable institutions to restrict the use of antimicrobials and take active measures in preventing the spread of drug resistance in a hospital.

Key words: Eitiology, risk factors, surgical site infections, SSI.

International Journal of Medicine and Medical Sciences ISSN 2167-0404  Vol. 10 (4), pp. 001-008, April, 2020. © International Scholars Journals

Full Length Research Paper

An investigation of ulcerogenic activity of ethanol extract from nuts of A. CATECHU in ethanol induced gastric mucosal injury in rats

Juhar F.K, Ibni A.D and Tuanku W.M

Department of Hostology, Faculty of Medicine, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia.

Accepted 19 December, 2019

Abstract

ARECA CATECHU L. (Arecaceae) nuts have been used in traditional medicine for the treatment of different diseases. The present study was performed to investigate the enhancement of ulcerogenic activity of ethanol extract from nuts of A. CATECHU in ethanol induced gastric mucosal injury in rats. Four groups of adult Sprague Dawley rats were orally pre-treated respectively with carboxymethyl cellulose (CMC) solution (ulcer control group), omeprazole 20 mg/kg (reference group), 250 and 500 mg/kg A. CATECHU nut extract in CMC solution (experimental groups) one hour before oral administration of absolute ethanol to generate gastric mucosal injury. After an additional hour, the rats were sacrificed and the ulcer areas of the gastric walls were determined. Grossly, the experimental groups exhibited significantly severe gastric mucosal injury compared to ulcer control group. Histological studies of the gastric wall revealed that experimental groups exhibited comparatively severe damage of gastric mucosa; along with edema and leucocytes infiltration of submucosal layer compared to ulcer control group. In conclusions, the present finding suggests that A. CATECHU nut extract enhanced ulcer production as ascertained grossly by significant increasing ulcer area, and histologically by comparatively increases in ulcer areas compared to ulcer control group.

Key words: Areca catechu nut, omeprazole, enhancement gastric ulcer, histology.