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Open access

Areeba Ahmad, Veena Maheshwari, Arif Ahmad, Rashid Saleem and Riaz Ahmad

Observation of Esterase-Like-Albumin Activity during N'-Nitrosodimethyl amine Induced Hepatic Fibrosis in a Mammalian Model

Aim: Hepatic fibrosis (HF) is characterized by irregular growth and amassing of fibrous scar tissues in the liver causing weakened hepatocytes metabolism and protein level alterations, including albumin. Albumin with Mr~68-70 kDa is unglycosylated soluble plasma protein with various biological roles. In this study, we demonstrate ‘esterase-like activity’ of albumin during NDMA-induced HF in rats.

Material and Methods: In rats, HF was induced by weekly i.p. injections of NDMA in doses of 10 mg/kg b.wt. Sera of controls (untreated) and treated rats were processed for biochemical tests, electrophoretic profiling and in-gel esterase activity localization using α, β-naphthyl acetates. H&E staining of liver sections (~ 5 μm) was done to confirm induction of HF.

Results: NDMA satisfactorily induces hepatic fibrosis within 21 days which is also evident by significant increase in SALP, SGOT, SGPT and bilirubin levels in rats. ‘Esterase-like activity’ of albumin detected in animal sera remains stable throughout the course of treatment irrespective of other biochemical changes.

Conclusion: During pathogenesis of HF, formation of stable esterase-albumin complex may have some important role and hence, prior recommending the use of albumin as diagnostic marker we propose further investigations to elucidate the mechanism of its formation.

Open access

Areeba Ahmad, Mohd Irshad, Waseem Ahmad, Abdul Khan and Riaz Ahmad

Analysis of Serum Proteins and Enzymes Level in Human Subjects with Osteoarthritis

The aim of the present study was to assess the serum proteins and enzymes level using polyacrylamide gel electrophoretic (PAGE) profiles in human subjects with osteoarthritis (OA). Forty-one subjects with confirmed OA were selected for the present study. Sera were collected from these individuals and loaded in equal amounts on native and denaturing PAGE separately. Software analysis of these profiles was done using Scion Imaging (Beta release-4, Scion Corporation) and GelPro (Media Cybernetics, USA) programs. To visualize esterases (Est) and lactate dehydrogenase (LDH) isoenzymes in the sera of these patients substrate specific staining was performed. Differences in the values of control and OA subjects were tested statistically. Software analysis of native-PAGE profiles revealed the presence of nineteen peptides in control and twenty one in OA subjects respectively. Two extra peptides were present in the β-globulins region of OA subjects. Significant decline from 42.77% to 34.72% in albumin levels (hypoalbuminemia) was observed in OA subjects with total albumin to globulin ratio 0.58. In SDS-PAGE, the difference in control and OA subjects was observed among eight peptides with molecular weight 25, 22 and 20 kDa (absent in OA) and five novel peptides 270, 125, 30, 21.36 and 18.4 kDa (absent in controls), while albumin retains the major activity. For enzymes, Est follow a relative order, BchEst (42.86%)> ArylEst (16.24%)>AchEst (6.85%) in OA subjects with the expression of a new BchEst isoform in 4.78% and two isoforms of ArylEst at 2.13 and 1.61% concentrations respectively. Significantly declined albumin esterase-like activity (AlbEst) was observed (34%) (P<0.05) in diseased subjects compared with controls (47%). Significant increase in LDH-5 and decline in LDH-1 and -2 isoenzymes were also observed in the sera of OA subjects. However, the overall rank of LDH isoenzymes was similar in control and OA subjects. Our results demonstrate noticeable differences in the sera PAGE profiles and enzymes activity in control and OA subjects and provide evidence to select serum for its use in the search for suitable biochemical markers in osteoarthritis.

Open access

Devoshree Mukherjee and Riaz Ahmad

Abstract

N′-Nitrosodiethylamine (NDEA) is an effective hepatotoxicant, carcinogen and mutagen. NDEA-induced hepatic necrosis, through metabolic activation by CYP2E1, is an extensively used experimental model. In the present study, we analysed the dose- and time-dependent effect of NDEA on hepatic damage, RBC rheology and proteomic profile in male Wistar rats. The rats, 5–6 weeks old, were divided into four groups: Group-1 served as control and received normal saline, Group-2 received a single dose of 200 mg/kg body weight NDEA intraperitoneally (i.p.) and the animals were sacrificed after one week; the rats of Group-3 received a single dose of 100 mg/kg body weight NDEA and were sacrificed after one week; Group-4 received 100 mg/kg body weight/wk NDEA for two weeks and were then sacrificed. Various biochemical parameters such as ALT, AST, ALP and bilirubin were determined. Further, RBC rheology, histopathology (H&E staining) of liver biopsies and polypeptide profiling (SDS-PAGE) in sera and liver sections were also carried out both in control and NDEA treated groups. Our results showed a significant increase in all the biochemical parameters of the liver function test (p<0.05). In NDEA treated categories dacryocytes (tear drop cells), schistocytes (fragmented cells), codocytes (target cells), acanthocytes (spur cells) and ovalocytes (oval cells) were observed. H & E stained liver biopsies treated with NDEA showed abnormal liver architecture with severe haemorrhage, neutrophilic infiltration and dysplastic hepatocytes manifested in a dose-dependent manner. Software analysis of SDS-PAGE of control and NDEA treated rat sera and liver revealed qualitative and quantitative differences in polypeptide composition. Based on the presence/absence, polypeptides were classified in three different categories: (1) house-keeping, present in all the groups investigated; (2) novel, present in either control or NDEA treated group at any given time; (3) differential expression, showing quantitative differences. Our study indicates a dose and time-dependent hepatocellular damage and proteome profile which is likely due to NDEA-mediated oxidative stress in rats.

Open access

Areeba Ahmad, Ravish Fatima, Veena Maheshwari and Riaz Ahmad

Effect of N'-nitrosodimethylamine on red blood cell rheology and proteomic profiles of brain in male albino rats

We investigated the effects of N'-nitrosodimethylamine (NDMA) induced toxicity on red blood cell rheology in male rats and identified bands in proteomic profiles of brain which can be used as novel markers. Polyacrylamide gel electrophoresis (PAGE) profiles exhibited constitutive as well as induced expression of the polypeptides. Remarkably, the molecular weight range of the polypeptides (8-150 kDa) corresponded to that of the family of heat shock proteins. Our results revealed significant changes in blood parameters and showed the presence of acanthocytes, tear drop cells, spicules and cobot rings in the treated categories. Lactate dehydrogenase and esterase zymograms displayed a shift to anaerobic metabolism generating hypoxia-like conditions. This study strongly suggests that NDMA treatment causes acute toxicity leading to cell membrane destruction and alters protein profiles in rats. It is therefore recommended that caution should be exercised in using NDMA to avoid risks, and if at all necessary strategies should be designed to combat such conditions.

Open access

Madeeha Riaz, Rehana Zia, Farhat Saleemi, Farooq Bashir, Riaz Ahmad and Tousif Hossain

Abstract

The mechanical properties of silicate glass-ceramics were evaluated based on the compressive strength tests. It was found that Ta2O5 addition improved densification, refinement of the microstructure and toughening of the bodies. The maximum compressive strength of the bodies with 1 mol% Ta2O5 was increased 3-fold (245.92 ±0.3 MPa) in comparison to undoped glass-ceramics which was measured to be 89.04 ±0.3 MPa, while for 3 mol% it became 4-fold (387.12 ±0.4 MPa) greater. The addition of Ta2O5 stabilized the system by controlling the biodegradation of the glass-ceramics. It effectively depressed the apatite formation as by addition of 3 mol% Ta2O5 no apatite layer was observed. It may be concluded from this study that mechanical and physical properties can be improved by the addition of Ta2O5, but at a cost of bioactivity. Still the optimized composition having Ta2O5 ⩽ 1 mol% may provide appropriate strength of biomaterials for high load bearing applications.

Open access

Riaz Ahmad, Absar-ul Hasnain, Arshad Khan and Mumtaz Alam

Presence of Circulating Lactate Dehydrogenase-Immunoglobulin G (LDH-IgG) Complex in the Sera of Post-Burn Patient

Lactate dehydrogenase (LDH) is an enzyme that belongs to the class oxidoreductase. It actively participates in the inter-conversion of lactate to pyruvate during anaerobic glycolysis in cell cytoplasm. Available literature suggests that there exist only five isoenzymes of LDH which on polyacrylamide gels (Native PAGE) resolve into five bands in normal healthy individuals. However, the presence of extra band in humans is either detected in reproductive tissues or during some pathological state. Here, we report a case in which an extra sixth band of LDH was visualized which forms a complex with IgG in the circulating sera of burn subject. The presence of LDH-IgG complex was confirmed in freshly collected sera using PAGE and immunological approaches. The complex get disappears from 2nd day onwards. The probable reason of the formation of this complex and its relation with the progression of the disease is discussed.

Open access

Usma Abbasi, Riaz Ahmad and Absar-ul Hasnain

Abstract

We have investigated biochemical properties of myofibrillar proteins of the digenetic trematode Isoparorchis hypselobagri, which correlate with its survival in the oxygen-rich swim bladder of its host catfish (Wallago attu). The polypeptide composition of the trematode’s natural actomyosin (NAM) was striated-muscle-like, with the exception that a 98-kD polypeptide corresponding to paramyosin also existed in its sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles. The profiles of immunoprecipitated NAM of the trematode support these inferences. Ca2+-sensitivity of myofibrillar contractility and Mg2+-ATPase activity of I. hypselobagri resembled troponin-linked calcium regulation of the host striated muscle. Myofibrillar permeability to water influx was insensitive to calcium chelation at neutral pH. However, the host swim bladder myofibrils displayed smooth-muscle-like polypeptide composition, pH dependence of contractility, Ca2+-sensitivity, ATPase activities, and inactivation kinetics. We propose 2 survival strategies that I. hypselobagri appears to have co-evolved: (i) fast-muscle-like musculature with exceptionally high contractility or ATPase activity; and (ii) type-II myosin resembling the host muscle in functional plasticity.

Open access

Riaz Ahmad, Nazia Nazam, Arshad Khan and Mumtaz Alam

Significance of Serum Lactate Dehydrogenase and its Isoenzymes During Post-Burn Follow-Up

The present study aims to evaluate the role of lactate dehydrogenase (LDH) isoenzymes in thermal burns. A total of 18 patients of both genders with 20 to 50% total burn surface area (TBSA), admitted to the Burn Ward of JN Medical College and Hospital was assessed. These patients were subjected to general and systemic examinations. The sera collected at day 1, 2, 5 and 10 during follow-up of burn patients were used for LDH quantitation. PAGE profiles showed significant differences in the levels of LDH isoenzymes in all the burn subjects (P=0.05). Software analysis of gel-scans showed the presence of five isoenzyme bands of which LDH-1 and -2 are the least contributors. During follow-up, it was observed that the ranking of LDH isoenzymes approaches control values at day 2 in 20% TBSA patients, while in the remaining cases it occurs at day 5. 3D-densitograms indicated high activity of LDH in 50% of TBSA patients even at day 10; however, the relative ranking of these isoenzymes was similar to control values (LDH-4>- 5>-3>-1>-2). We were of the opinion that the high activity of LDH enzyme is due to the enzyme-immunoglobulin-G (LDH-IgG) complex, but surprisingly we did not observe this complex in 50% of burn patients at any of the durations. Therefore, it is suggested that LDH isoenzymes play a role in the pathophysiology of the disease and can be an asset to ascertain the invisible tissue damage. Moreover, the high activity of LDH in 50% of burns is due to some unknown mechanism and not due to the binding of LDH with IgG.

Open access

Riaz Ahmad, Saba Qayyum, Absar-ul Hasnain, Anjum Ara, Arshad Khan and Mumtaz Alam

Observation on the Changes in Lactate Dehydrogenase Isoenzymes in Post-Burn Patients: Significance in Relation to Creatine Kinase

The present study deals with the quantitative assessment of lactate dehydrogenase isoenzymes in the sera of burn subjects. Efforts are also made here to show better predictive marker value of sera LDH, as a few other known protein markers like creatine kinase and myoglobin have limited analytical value in the management of thermal burns. Blood was initially collected at day-1 of admission from 29 burn and 10 healthy subjects. Further, the sampling was carried out at 2, 5, 10, 20 and 30 days of wound healing (recovery). Plasma and sera LDH isoenzymes were monitored on 7.5% polyacrylamide gel electrophoresis. Quantitative assessment of LDH isoenzymes was done from gelscans using GelPro and Scion Imaging softwares. Sera CK levels were estimated colorimetrically using reagent kits. Our results show that quantitative changes in LDH isoenzyme were more convincing and interpretable in the sera than plasma. Sera LDH-5 isoenzyme was detected as the major contributor of total sera LDH activity, which follows a change parallel to sera CK in burn subjects. Sera LDH-5 activity also remains significantly high for up to 10 days while sera CK levels were detected elevated up to 5 days (P<0.05) during the recovery of patients. Therefore, the present findings strongly recommended the use of sera to assess the LDH activity and indicate better stability of sera LDH-5 than sera CK during post burn wound healing.

Open access

Riaz Ahmad, Asma Farooqi, Jiazhong Zhang and Nasir Ali

Abstract

A steady flow of a power law fluid through an artery with a stenosis has been analyzed. The equation governing the flow is derived under the assumption of mild stenosis. An exact solution of the governing equation is obtained, which is then used to study the effects of various parameters of interest on axial velocity, resistance to flow and shear stress distribution. It is found that axial velocity increases while resistance to flow decreases when going from shear-thinning to shear-thickening fluid. Moreover, the magnitude of shear stress decreases by increasing the tapering parameter. This problem was already addressed by Nadeem et al. [14], but the results presented by them were erroneous due to a mistake in the derivation of the governing equation of the flow. This mistake is highlighted in the "Formulation of the Problem" section.