CXC ligand 13 in rheumatoid arthritis and its relation to secondary Sjögren’s syndrome

Aim of the workThe aim of the present study was to measure the level of the chemokine CXC ligand 13 protein (CXCL13) in the plasma and unstimulated saliva of rheumatoid arthritis (RA) patients in order to find out its role in the disease activity and its relation to secondary Sjögren’s syndrome (sSS).Patients and methodsThe study was conducted on thirty rheumatoid arthritis patients attending the Outpatient Clinic of Rheumatology and Rehabilitation department of Ain shams University Hospitals. The patients’ group had been classified into group (1) which included fifteen RA patients associated with sSS diagnosed according to the American–European Consensus Group Classification Criteria and group (2) which included fifteen RA patients not associated with sSS. Ten healthy subjects were included as a control group. Patients were subjected to full history taking, clinical examination, and laboratory detection of CXCL13 level in the plasma and saliva of patients as well as the control groups using ELISA technique. Assessment of disease activity in RA patients was done using the disease activity score (DAS28).ResultsPlasma levels of CXCL13 were significantly higher in RA patients than control group (p < 0.001). Plasma levels of CXCL13 were significantly correlated with the RA disease activity (r = 0.677, p < 0.001) and disease duration (r = 0.406, p < 0.05), while the salivary levels were higher in those with sSS and correlated with sSS disease duration (r = 0.536, p < 0.05). A highly significant correlation was found between salivary CXCL13 and severity of sSS (r = 0.816, p < 0.001). Salivary levels of CXCL13 above 110 pg/ml may diagnose sSS with sensitivity 80% and specificity 84%.ConclusionThe results of this preliminary study point out the importance of CXCL13 as a marker for RA disease activity, its role in diagnosing sSS, and estimation of sSS severity.     

Difficulties in Differentiating Coronaviruses from Subcellular Structures in Human Tissues by Electron Microscopy

Efforts to combat the coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have placed a renewed focus on the use of transmission electron microscopy for identifying coronavirus in tissues. In attempts to attribute pathology of COVID-19 patients directly to tissue damage caused by SARS-CoV-2, investigators have inaccurately reported subcellular structures, including coated vesicles, multivesicular bodies, and vesiculating rough endoplasmic reticulum, as coronavirus particles. We describe morphologic features of coronavirus that distinguish it from subcellular structures, including particle size range (60–140 nm), intracellular particle location within membrane-bound vacuoles, and a nucleocapsid appearing in cross section as dense dots (6–12 nm) within the particles. In addition, although the characteristic spikes of coronaviruses may be visible on the virus surface, especially on extracellular particles, they are less evident in thin sections than in negative stain preparations.     

The possible antianginal effect of allopurinol in vasopressin-induced ischemic model in rats

The anti-anginal effects of allopurinol were assessed in experimental model rats of angina and their effects were evaluated with amlodipine. In the vasopressin-induced angina model, oral administration of allopurinol in dose of 10 mg/kg revealed remarkably analogous effects in comparison with amlodipine such as dose-dependent suppression of vasopressin-triggered time, duration and severity of ST depression. In addition, allopurinol produced dose dependent suppression of plasma Malondialdehyde (MDA) level, systolic blood pressure, cardiac contractility and cardiac oxygen consumption; while in contrast, amlodipine minimally suppressed the elevation of plasma MDA level. Endothelial NO synthase (eNOS) expression, serum nitrate were strikingly increased, however lipid profile was significantly reduced. Seemingly, allopurinol was found to be more potent than amlodipine – a calcium channel antagonist. To conclude, it was explicitly observed and verified that on the ischemic electrocardiography (ECG) changes in angina pectoris model in rats, allopurinol exerts a significant protective effects, reminiscent of enhancement of vascular oxidative stress, function of endothelial cells, improved coronary blood flow in addition to the potential enhancement in myocardial stress. Moreover, our findings were in conformity with several human studies.     

Minimally invasive single-session double-level rotational osteotomy of the forearm bones to correct fixed pronation deformity in congenital proximal radioulnar synostosis

BackgroundCongenital proximal radioulnar synostosis is the most common congenital disease of the elbow joints and forearms.MethodsThis was a prospective study of 12 consecutive children (14 forearms) who presented to the National Institute of Neuromotor System in Egypt between September 2012 and September 2013 with severe congenital proximal radioulnar synostosis, having a mean pronation deformity of 70.7° (range 60°–85°), and who underwent operative correction by single-session double-level rotational osteotomy and percutaneous intramedullary K-wires of both the radius and ulna. Ten forearms were type III, and four were type II according to Cleary and Omer classification. The mean age at the time of surgery was 5 years and 2 months (range 4 years and 10 months to 6 years and 5 months). They were evaluated for functional results after rotational corrective osteotomy at a mean interval of 30.4 months (range 24–36 months) by physical examination and radiographs.ResultsAll children had a mean pronation deformity correction of 59.8° (range 30°–90°) reaching a final position of 20°–30° of pronation in the affected dominant extremities and 20° of supination in the affected non-dominant extremities after osteotomy. All children showed improvement in functional activities, with no loss of correction or non-union in any child, and no circulatory disturbances, neuropathies, or hypertrophic scars.ConclusionMinimally invasive single-session double-level rotation osteotomy of the proximal ulna and distal radius with percutaneous intramedullary K-wire fixation is a safe, technically simple and efficient procedure which corrects pronation deformity.     

Phospholipase C from Pseudomonas aeruginosa and Bacillus cereus:characterization of catalytic activity

Objective:To study characteristics of phospholipases C(PLCs),their importance for producing microorganisms us well us the potential of their use for industrial purposes.Methods:PLC from Bacillus cereus(B.cereus) D101 was selected as an example of Gram-positive PLCs and PLC from Pseudomanas aeruginosa(P.aeruginosa) D183 of Gram-negative ones.Enzymes were partially purified by ammonium sulfate precipitation followed by membrane dialysis.Partially purified preparations were used to study effect of different factors on activities as well as in substrate specificity tests which were conducted using a turbidimetric assay method.Results:Maximum activity was at pH 7 and 8 and 40 ℃ for P.aeruginosa PLC,and pH 8-10 and 37 ℃ for B.cereus PLC.Both PLCs were inhibited by Pi at 5 mM or higher,whereas,PLC from B.cereus only was inhibited by EDTA.Activity of P.aeruginosa PLC was not affected by removing Zn~(2+) ions from reaction mixture or their replacement with Ca~(2+),Ba~(2+),Mg~(2+) or Mn~(2+)ions.Vis-a-vis,activity of B.cereus PLC was found to be metal ion dependent PLCs from both isolates were relatively thermostable and showed maximum affinity toward phosphatidylcholine.Sphingomyelin and phosphatidylethanolamine were not good substrates and phosphatidylinositol,phosphatidylserine,phosphatidylglycerol and cardiolipin could be considered nonsubstrates.Conclusions:Human body physiological conditions could favor activity of P.aeruginosa and B.cereus PLCs.These enzymes may participate in phosphate scavenging and virulence of producing isolates but not in autolysis.PLCs from both isolates are potential candidates for industrial use.