Muhammad Asif Nawaz

1. A class of useful biological catalysts, pectinase catalyses the breakdown of plant-based pectin-rich polysaccharides. Pectin is a complex heteropolysaccharide which is mainly composed of galactu...

To increase its operational stability and ongoing reusability, B. subtilis pectinase was immobilized on iron oxide nanocarrier. Through co-precipitation, magnetic iron oxide nanoparticles were synthesized. Scanning electron microscopy (SEM) and energy dispersive electron microscopy (EDEX) were used to analyze the nanoparticles. Pectinase was immobilized using glutaraldehyde as a crosslinking agent on iron oxide nanocarrier. In comparison to free pectinase, immobilized pectinase demonstrated higher enzymatic activity at a variety of temperatures and pH levels. Immobilization also boosted pectinase’s catalytic stability. After 120 h of pre-incubation at 50 °C, immobilized pectinase maintained more than 90% of its initial activity due to the iron oxide nanocarrier, which improved the thermal stability of pectinase at various temperatures. Following 15 repetitions of enzymatic reactions, immobilized pectinase still exhibited 90% of its initial activity. According to the results, pectinase’s catalytic capabilities were enhanced by its immobilization on iron oxide nanocarrier, making it economically suitable for industrial use.

An automated, qualitative and semi-quantitative micro-assay for the detection of plant lectins also known as phyto-agglutinins (glycoproteins; have exciting applications in medicines) is described as an alternative to conventional assays. The method developed in this work is based on hemagglutination (HA) assay that can simultaneously detect the presence and concentration (titer) of lectins in as many as 96 different samples without the aid of an expert eye. We used rice (Oryza sativa L.) seeds for making clarified lectin extracts and Arabic gum as positive control in phosphate buffer saline; the method is applicable to all kinds and parts of the plants. Rabbit red blood cells were used in order to carry out the HA assay in a miniaturized experiment using U-welled microplates (MPs). 25 µL of plant extract is sufficient to carry out HA micro-assay at incubation temperature of 38°C for 20 min. The method was standardized with an expert eye and automated by using MP reader. Moreover, a standard curve for the direct interpretation of lectin concentration is also developed by conversion of absorbance values into titer. The method described will save time, material, labor, and simplify the rapid semi-quantification of plant lectins.

This study was designed to evaluate the emulsifying and rheological properties of acorn protein isolate (API) in different pH mediums (pH 3, 7 and 9) and in the presence of ionic salts (1 M NaCl and 1 M CaCl₂). API shows higher solubility in distilled water at pH 7, while at the same pH, a decrease in solubility was observed for API in the presence of CaCl₂ (61.30%). A lower emulsifying activity index (EAI), lower stability index (ESI), larger droplet sizes and slight flocculation were observed for API in the presence of salts at different pHs. Importantly, CaCl₂ treated samples showed relevantly higher EAI (252.67 m²/g) and ESI (152.67 min) values at all pH as compared to NaCl (221.76 m²/g), (111.82 min), respectively. A significant increase in interfacial protein concentration (4.61 mg/m²) was observed for emulsion at pH 9 with CaCl₂, while the major fractions of API were observed in an interfacial layer after SDS-PAGE analysis. All of the emulsion shows shear thinning behavior (τ_c > 0 and n < 1), while the highest viscosity was observed for emulsion prepared with CaCl₂ at pH 3 (11.03 ± 1.62). In conclusion, API, in the presence of ionic salts at acidic, neutral and basic pH, can produce natural emulsions, which could be substitutes for synthetic surfactants for such formulations.

Lectins are unique glycoproteins that react with specific sugar residues on cell surfaces resulting in agglutination. They offer enormous applications in therapeutics, diagnostics, medicine, and agriculture. Rice lectins are naturally expressed during biotic and abiotic stresses suggesting their importance in stress resistance physiology. The objective of this study was to determine the presence and relative concentration of lectins in different accessions of rice obtained from IABGR/NARC Islamabad mainly originated from Pakistan. About 210 rice accessions including 02 local varieties and 05 transgenic seeds were screened for seed lectins using a hemagglutination (HA) assay with 5% Californian bred rabbits’ erythrocytes. A protein concentration of 3–8 mg/100 mg of seed flour was measured for all the rice accessions; the highest was 8.03 mg for accession 7600, while the lowest noted was 3.05 mg for accession 7753. Out of 210 accessions, 106 showed the highest HA activity. These 106 genotypes were further screened for titer analysis and specific activity. The highest titer and specific activity were observed for accession 7271 as 1024 and 236 hemagglutination unit (HAU), respectively. The selected accessions’ relative affinity and HA capability were evaluated using blood from four different sources: human, broiler chicken, local rabbit, and Californian-breed rabbit. The highest HA activity was observed with Californian-breed rabbit RBCs. The lectin assay was stable for about 1–2 h. After the required investigations, the accessions with higher lectin concentration and HA capability could be used as a readily available source of lectins for further characterization and utilization in crop improvement programs.

Objective: To assess morbidity and success of transabdominal (O’Conor) repair of vesicovaginal fistula with orwithout interposition of flap between vagina and urinary bladder. Study Design: Prospective comparative study. Place and Duration of Study: Armed Forces Institute of Urology, Rawalpindi, from Mar 2016 to Jan 2019. Methodology: Fifty five patients were randomized into group A & B by lottery method. An inclusion criterionwas single fistulous opening of ≤3cm. Complex and recurrent fistulae were excluded. Patients in group A underwent O’Conor repair without interpositional flap while in group B vesicovaginal fistulae were repaired with flap interposition. Results: Twenty two patients were randomized in group A while 27 in group B. Mean age of patients was 41.65± 11.93 years. Gynecological and obstetrical surgery was the main cause of fistula. Mean duration of surgerywas 162.7 ± 18.49 minutes. Per-operative ureteric catheterization was done in 9 (16.8%) patients. Seventeen(30.6%) patients had paralytic ileus. There was transient fever in 4 (7.6%) of cases and wound infection was seenin 3 (5.8%) of patients. Mean hospital stay was 3.4 ± 2.3 days. Cystogram was done in 35 (64.5%) of patients before the removal of per-urethral catheter. The overall success rate was 92.9%. Ten (18.2%) of patients developed denovo urgency which was managed conservatively. There was no statistical difference in both groups in terms of morbidity and success. Conclusion: In simple Vesico-vaginal fistulae repair, interposition of flap can be omitted and it does not affect the outcomes in terms of success and morbidity.