Leflunomide-induced cardiac injury in adult male mice and bioinformatic approach identifying Nrf2/NF-κb signaling interplay

Leflunomide (LFND) is an immunosuppressive and immunomodulatory disease-modifying antirheumatic drug (DMARD) that was approved for treating rheumatoid arthritis. LFND-induced cardiotoxicity was not fully investigated since its approval. We investigated the cardiac injury in male mice and identified the role of nuclear factor erythroid 2-related factor 2/nuclear factor-κ B (Nrf2/NF-κB) signaling. Male albino mice were assigned into five groups as control, vehicle, and LFND (2.5, 5, and 10 mg/kg). We investigated cardiac enzymes, histopathology, and the mRNA expression of Nrf2, NF-κB, BAX, and tumor necrosis factor-α (TNF-α). The bioinformatic study identified the interaction between LFND and Nrf2/NF-κB signaling; this was confirmed by amelioration in mRNA expression (0.5- to 0.34-fold decrease in Nrf2 and 2.6- to 4.61-fold increases in NF-κB genes) and increased (1.76- and 2.625-fold) serum creatine kinase (CK) and 1.38- and 2.33-fold increases in creatine kinase-MB (CK-MB). Histopathological results confirmed the dose-dependent effects of LFND on cardiac muscle structure in the form of cytoplasmic, nuclear, and vascular changes in addition to increased collagen deposits and apoptosis which were increased compared to controls especially with LFND 10 mg/kg. The current study elicits the dose-dependent cardiac injury induced by LFND administration and highlights, for the first time, dysregulation in Nrf2/NF-κB signaling.

Influence of Surface-Modification via PEGylation or Chitosanization of Lipidic Nanocarriers on In Vivo Pharmacokinetic/Pharmacodynamic Profiles of Apixaban

Nanostructured lipid carriers (NLCs) have been proven to significantly improve the bioavailability and efficacy of many drugs; however, they still have many limitations. These limitations could hinder their potential for enhancing the bioavailability of poorly water-soluble drugs and, therefore, require further amendments. From this perspective, we have investigated how the chitosanization and PEGylation of NLCs affected their ability to function as a delivery system for apixaban (APX). These surface modifications could enhance the ability of NLCs to improve the bioavailability and pharmacodynamic activity of the loaded drug. In vitro and in vivo studies were carried out to examine APX-loaded NLCs, chitosan-modified NLCs, and PEGylated NLCs. The three nanoarchitectures displayed a Higuchi-diffusion release pattern in vitro, in addition to having their vesicular outline proven via electron microscopy. PEGylated and chitosanized NLCs retained good stability over 3 months, versus the nonPEGylated and nonchitosanized NLCs. Interestingly, APX-loaded chitosan-modified NLCs displayed better stability than the APX-loaded PEGylated NLCs, in terms of mean vesicle size after 90 days. On the other hand, the absorption profile of APX (AUC_0-inf) in rats pretreated with APX-loaded PEGylated NLCs (108.59 µg·mL^-1·h^-1) was significantly higher than the AUC_0-inf of APX in rats pretreated with APX-loaded chitosan-modified NLCs (93.397 µg·mL^-1·h^-1), and both were also significantly higher than AUC_0-inf of APX-Loaded NLCs (55.435 µg·mL^-1·h^-1). Chitosan-coated NLCs enhanced APX anticoagulant activity with increased prothrombin time and activated partial thromboplastin time by 1.6- and 1.55-folds, respectively, compared to unmodified NLCs, and by 1.23- and 1.37-folds, respectively, compared to PEGylated NLCs. The PEGylation and chitosanization of NLCs enhanced the bioavailability and anticoagulant activity of APX over the nonmodified NLCs; this highlighted the importance of both approaches.

Memantine mitigates ROS/TXNIP/NLRP3 signaling and protects against mouse diabetic retinopathy: Histopathologic, ultrastructural and bioinformatic studies

Diabetic retinopathy (DRET) triggers vision loss in adults, however, little therapeutic options are existing. Memantine is an anti-Alzheimer drug that antagonizes the activity of glutamate at N-methyl-D-aspartate (NMDA) receptors. Glutamate and thioredoxin-interacting protein (TXNIP) are known to be overexpressed in diabetic retinas and can produce activation of NOD-like receptor protein 3 (NLRP3) with subsequent secretion of interlukin-1β. This study repurposed memantine for its neuroprotective effect in experimental DRET and tested its impact on ROS/TXNIP/NLRP3. In addition, KEGG pathway database and STRING database identified the protein-protein interaction between glutamate receptors and TXNIP/NLRP3. Male Swiss albino mice received alloxan (180 mg/kg) to induce DRET. After 9 weeks, we divided the mice into groups: (a) saline, (ii) DRET, (iii and iv) DRET + oral memantine (5 or 10 mg per kg) for 28 days. Then, mice were euthanized, and eyeballs were removed. Retinal samples were utilized for biochemical, histopathological, and electron microscopy studies. Retinal levels of glutamate, TXNIP, NLRP3 and interlukin-1β were estimated using ELISA technique as well as retinal malondialdehyde. Histopathological and ultrastructural examination demonstrated that oral memantine attenuated vacuolization and restored normal retinal cell layers. Moreover, memantine reduced TXNIP, NLRP3, interleukin-1β and MDA concentrations. These results provide evidence demonstrating memantine' efficacy in alleviating DRET via suppressing reactive oxygen species/TXNIP/NLRP3 signaling cascade. Therefore, memantine might serve as a potential therapy for retinopathy after adequate clinical research.

Implementing group research assignment in undergraduate medical curriculum; impact on students' performance and satisfaction

BACKGROUND

Medical educators need to integrate research skills within undergraduate medical curriculum to help students perceive their relevance to routine doctor's practice. The current work aimed to assess the impact of including group research assignment in the endocrine module to third year medical students on attaining some research, communication and E learning skills and on their performance in the module.

METHODS

Students carried out a group research activity (N = 10), wrote a report and presented their work as a poster, booklet or video clip. Multiple evaluation methods were used; a questionnaire to assess students' satisfaction and perception towards the skills acquired and a rubric to grade the research report and presentation. Also, students' final grades in the module were compared with that of the previous cohort who didn't conduct the research assignment.

RESULTS

Students' response rate to the questionnaire was 50%. 73.6% of students agreed that research enhanced critical evaluation of literature while 65.5% felt confident to further participate in research and 66.7% were satisfied about the whole research experience. Mean score of assignment was 84% for female students and 78% for male students. Grades of the current cohort in the endocrine module were significantly higher than that of the preceding cohort (78.7 ± 11 and 70.2 ± 13 respectively P< 0.001).

CONCLUSION

The current study pointed to the positive impact of implementing group research assignment within the undergraduate medical curriculum. Students were satisfied about the research exposure, agreed attaining some skills and got higher grades than preceding peers.

THU0588 TAKAYASU’S ARTERITIS PRESENTING WITH UNILATERAL DIGITAL CLUBBING IN A 23 YEAR-OLD MALE

Background:

Takayasu Arteritis is a chronic, large vessel arteritis that commonly involves the aorta and its major branches, mostly the ascending/descending aorta, subclavian arteries, and carotids [1].

Herein, we report a case of a 23 year-old medically free Indian male who presented to our hospital in acute distress complaining of cough, hemoptysis and shortness of breath for one week as well as intermittent fever and fatigue for five months. He presented with a BP of 140/100 mmHg as well was both systolic and early diastolic murmurs in the mitral and aortic areas, respectively. He also had a paraumbilical bruit and unilateral clubbing in the left hand with digital ischemia of the left index finger. Doppler ultrasound of the left arm showed monophasic flow pattern with low velocity in left distal radial, distal ulnar, and all digital arteries, except the second digital arteries; low velocity in the median artery; and no flow in the lateral artery of second digit (Figure 1). Computed tomography angiogram (CT Angio) (Figure 2) of the chest, abdomen, and pelvis showed fusiform aneurysm dilatation of the thoracic aorta extending into the right braciocephalic and subclavian arteries as well as the right common carotid artery.

Figure 1.Figure 2.

Unilateral clubbing in patients with TA occurs as a result of subclavian artery stenosis that leads to tissue ischemia and hypoxia [2-4]. In turn, the bone marrow release megakaryocytes, which enter the systemic circulation when an A-V shunt exists [5]. Platelet-derived growth factor (PDGF) (release from megakaryocytes) and vascular endothelial growth factor (VEGF) levels are highly expressed in the connective tissues of nail beds, leading to its proliferation and platelets clumps‘ accumulation [6, 7].

Objectives:

To report the fourth case worldwide and third case of an adult, respectively, with Takayasu’s arteritis who presents with unilateral clubbing.

Methods:

Our patient was started on pulse steroid therapy of methylprednisolone 1 gram IV od for 5 days and later switched to prednisolone 20 mg po BID. He also received methotrexate 10 mg PO once weekly and rituximab 750 mg IV stat; another dose of rituximab was given two weeks later.

Results:

His clubbing has significantly improved within 2 weeks of starting immunosuppressive therapy. He was discharged with follow up on methotrexate 12.5 mg PO once weekly and prednisilone 20 mg PO OD (to be tapered). Clubbing improved by a rate of 60% two weeks following discharge in two weeks.

Conclusion:

In all four cases of Takayasu arteries presenting with unilateral clubbing, patients’ clinical condition including presence of clubbing improved after initiation of immunosuppressive therapy.

References:

[1]Alibaz-Öner, F., Aydin, S. Z., & Direskeneli, H. (2015). Recent advances in Takayasu’s arteritis.European Journal of Rheumatology,2(1), 24–30.

[2]Kaditis AG, Nelson AM, Driscoll DJ. Takayasu\’s arteritis presenting with unilateral digital clubbing. J Rheumatol 1995;22:2346-8.

[3]Ishikawa M, Okada J, Kondo H. Takayasu’s arteritis with transient clubbed finger. Clin Exp Rheumatol 1999;17:629-30.

[4]Bivilibal M, Duru N, Dogdu G, Elevli M, Ayta S. A Takayasu’s Arteritis Case with Unilateral Digital Clubbing. Turk J Rheumatol. 2011;26(2):163–166.

[5]Martínez-Lavín M. Hypertrophic osteoarthropathy. Curr Opin Rheumatol. 1997 Jan;9(1):83-6. Review. PubMed PMID: 9110140.

[6]Dickinson CJ, Martin JF. Megakaryocytes and platelet clumps as the cause of finger clubbing. Lancet 1987;2:1434-5.

[7]Atkinson S, Fox SB. Vascular endothelial growth factor (VEGF)-A and platelet-derived growth factor (PDGF) play a central role in the pathogenesis of digital clubbing. J Pathol 2004;203:721-8.

Disclosure of Interests:

None declared

Association of genetic polymorphisms of chemokines and their receptors with clearance or persistence of hepatitis C virus infection

BACKGROUND

Polymorphisms of certain genes may have an effect on either persistence of infection or spontaneous clearance of hepatitis C virus (HCV). We hypothesized that one or more variants of chemokines (CCL2 and CCL5) and chemokine receptors (CC chemokine receptor type 2 [CCR2]) genes are associated with the susceptibility to HCV infection.

METHODS

We recruited 1460 patients with chronic HCV (CHC), 108 subjects with spontaneous virus clearance (SVC) and 1446 individuals as a healthy control group. All were genotyped for single nucleotide polymorphisms: rs13900 C/T of CCL2, rs3817655 T/A of CCL5 and rs743660 G/A and rs1799864 G/A of CCR2 using allelic discrimination real-time PCR technique.

RESULTS

The carriage of the A allele of CCR2 rs743660 was significantly higher in CHC compared to SVC (odds ratio [OR] 4.03) and to controls (1.42) and in controls compared to SVC (2.85) (all P < 0.01). Similarly, the A allele of CCR2 rs1799864 was significantly higher in the CHC group when compared with both SVC (1.97) and controls (2.13) (both P < 0.01), but the OR between controls and SVC was not significant (1.08, P = 0.723). Carriage of C allele of CCL2 rs13900 and the T allele of CCL5 rs3817655 were significantly higher in SVC group when compared with both CHC (OR = 0.19 and OR = 0.24, respectively) and control groups (OR = 0.65 and OR = 0.45, respectively [all P < 0.01]).

CONCLUSIONS

Susceptibility to HCV infection is associated with A alleles of both (rs743660 and rs1799864 G/A) of CCR2 while spontaneous clearance of HCV is associated with the C allele of rs13900 of CCL2 and T allele of rs3817655 of CCL5.

Integrated gasification combined cycle using Egyptian Maghara coal-rice straw feedstock

Rice straw is an agricultural waste that causes an annoying problem in Egypt if it is not well exploited. This study focuses on using this waste in power generation by co-gasification of Egyptian Maghara coal and rice straw blends using entrained flow gasifier technology. Aspen Plus was used to conduct a parametric study for investigation of the effect of changing the inputs to the gasifier on the produced gas composition. Three different input parameters, influencing the performance of the gasifier, including the percentage of coal to rice straw in the blend, the fraction of added water to the blend, and the mass percentage of oxygen with respect to the mass of the blend fed to the gasifier were analysed. Two alternative power production schemes (with and without carbon capturing) have been investigated. The obtained optimum feed conditions are: 40% coal in the feed blend, 20% water concentration in the feed slurry, and 80% oxygen with respect to the dry feed blend to the gasifier. For (10 0000 kg per hour) of the feed blend, the power generated was 270.1 MW in the case of non-carbon capturing, while in the case of carbon capturing, 263.52 MW was generated. Although it produces less power, applying carbon capturing techniques means handling less flue gas and thus using smaller gas turbines and results in more environmentally friendly emissions.

Serum and Urinary Interferon-Gamma-Inducible Protein 10 in Lupus Nephritis

BACKGROUND

Lupus nephritis is a serious manifestation of systemic lupus erythematosus (SLE). The objective of this study was to identify the sensitivity, specificity, and cut-off values of IP-10 in the serum and urine of patients with lupus nephritis compared to renal biopsy, albumin/creatinine ratio, and serum anti-dsDNA.

METHODS

Thirty female SLE patients were included. SLEDAI was calculated and blood and urine samples were collected. Patients were divided into 10 SLE patients with renal involvement (six active and four inactive), 10 active SLE, and 10 inactive SLE patients. Ten age-matched healthy (control) were included. Serum and urinary levels of IP-10 were measured by ELISA. Anti-dsDNA, urine albumin/creatinine ratio were performed.

RESULTS

Serum and urinary IP-10 in active SLE patients had significantly increased levels as compared to inactive SLE patients (P = 0.015, P = 0.033, respectively). However, there was no difference in serum and urinary levels between active renal and active non-renal patients. Albumin/creatinine ratio is a better marker in differentiating between lupus nephritis and SLE with no renal involvement. Any of serum and urinary IP-10, albumin/creatinine ratio, and anti-dsDNA did not correlate with the class of lupus nephritis in renal biopsy.

CONCLUSION

Urinary and serum IP-10 are useful markers of lupus activity, but not indicative of renal activity. Albumin/creatinine ratio is superior in identifying lupus nephritis and renal activity.

Feasibility and outcomes of endovascular embolization of cerebral arteriovenous malformations at a low-volume centre

BACKGROUND AND PURPOSE

Herein, we report our initial experience with the endovascular management of cerebral arteriovenous malformations (AVMs) using the liquid embolic agent Onyx and n-butyl cyanoacrylate for AVM embolization.

METHODS

We reviewed data from 15 patients with brain AVMs, who were observed at our endovascular facility from January 2008 to July 2011. All cases were embolized with Onyx and/or n-butyl cyanoacrylate. There were 8 women and 7 men with a mean age of 27.2 years (range 17-43 years). The clinical presentations included intracerebral haemorrhage (n = 7), seizures (n = 4), headache (n = 2), and focal neurological deficits (n = 2); according to the Spetzler-Martin classification (Spetzler R and Martin N (1986) J NeurosurgV65 446-83), 8 AVMs were grades I-II, 5 were grade III, and 2 were grades IV-V.

RESULTS

A total of 31 embolization procedures were performed in 15 patients, and 44 feeding pedicles were embolized, ranging from 1 to 5 per patient, with an average size reduction of 70% (median 75%, range 40-100%). Total obliteration was achieved for 3 AVMs (20%) (2 patients had single feeders and 1 patient had double feeders), and a partial embolization was achieved in 12 patients (80%). The procedure was related to a permanent disabling morbidity in one patient (6.6%), and no mortalities occurred.

CONCLUSIONS

The outcome of (AVM) embolization in our centre is comparable to the reported outcome in other larger-volume centres. The feasibility and safety of AVM embolization in our low-volume centre are similar to the outcomes reported at high-volume centre.

Occupational and environmental risk factors for idiopathic pulmonary fibrosis in Egypt: a multicenter case-control study

BACKGROUND

Despite the advances in medical therapy and technology, the prognosis of idiopathic pulmonary fibrosis (IPF) remains poor and the need for disease prevention based on identifying the risk factors becomes mandatory. Occupational and environmental exposures were studied in several countries and found to play important role in the disease development. However, in Egypt, a little attention has been paid to study the effect of these factors in the disease development.

OBJECTIVE

To identify the occupational and environmental risk factors associated with the development of IPF in Egypt.

METHODS

A multicenter hospital-based case-control study was carried out in chest hospitals affiliated to three Egyptian cities-Cairo, Tanta and Mansoura. Subjects were 201 patients with confirmed IPF (cases) and 205 age-, sex- and residence-matched controls. Data on occupational and environmental factors were obtained from a questionnaire. Multiple logistic regression analysis was used to determine the independent risk factors of IPF in both sexes for single factors with adjustment for age, residence and smoking status.

RESULTS

Compared with the controls, the risk of IPF in male workers was observed to increase significantly in chemical and petrochemical industries and carpentry and wood working (OR = 2.56, 95% CI: 1.02-7.01), and with occupational exposures to wood dust and wood preservatives. Among female workers, a significant increase was observed in farming (OR = 3.34, 95% CI: 1.17-10.12), raising birds and occupational exposures to animal feeds, products and dusts and pesticides. Risk of IPF decreased significantly in male workers and insignificantly among female workers in sales and clerical related activities. The environmental exposures to birds and cats were significantly associated with elevated risk of IPF development in both sexes.

CONCLUSION

In Egypt, farming, raising birds and wood working are important risk factors for the development of IPF.

Generation and characterization of a novel hematopoietic progenitor cell line with DC differentiation potential

Studies of hematopoietic stem cell (HSC)-derived dendritic cells (DCs) are often limited by the rarity of HSC. To facilitate the study of DCs, we have generated a novel cell line (CR1) by retroviral Notch(IC) gene transfer into Sca1(+)ckit(+)lin- HSC. CR1 cells proliferated in vitro in the presence of recombinant interleukin-3. They maintained an immature progenitor cell phenotype and an intact karyotype. In the presence of granulocyte-macrophage colony-stimulating factor or Flt3L, CR1 cells differentiated into myeloid and plasmacytoid DCs, respectively. Functionally, CR1 cells were comparable to primary bone-marrow-derived DCs with respect to Toll-like-receptor-mediated maturation, cytokine release and capacity to induce effective antitumor immunity. CR1 cells thus provide an elegant new cellular tool to study DC development, function and preclinical DC-based immunotherapies.

Clinicopathological studies on neurectomy in equids

Clinical and pathological changes following neurectomy were studied experimentally in 46 male and female equids. Sixty-three operations were performed using either the traditional or the Fackelman and Clodius methods of neurectomy. The effect of arteriovenous ligation was studied in 12 animals and 20 angiograms were performed post mortem to study the arterial pattern of the extremities of the operated limb. Neuroma formation (31 cases) and sloughing of the hoof (five cases) were the two main untoward sequelae. Neurectomy by the technique of Fackelman and Clodius proved superior to the traditional method. No essential changes were observed after ligation of the blood vessels, except in one case where collateral circulation was established.