Molecular characteristics of extended-spectrum beta-lactamases among gram-negative isolates collected in Cairo University Hospital

Phenotyping is commonly used for detection of extended-spectrum beta-lactamase (ESBL) production in gram-negative isolates. ESBLs are mainly coded for by four important genes, namely bla (TEM), bla (SHV), bla (CTX-M), and bla (OXA). Our aim in this study is to assess use of a multiplex PCR as a rapid method to identify four common genes responsible for ESBL production in different gram-negative isolates. All 793 clinical isolates are subjected to both screen and confirmatory testing for ESBL production using double disc synergy testing (DDST). Two hundred isolates with the ESBL phenotype are subjected to multiplex PCR for detection of the four genes bla (TEM, SHV, CTX-M, and OXA). The isolates were obtained from various clinical specimens: 68 (34 %) were isolated from urine cultures, 43 (21.5 %) from sputum, 26 (13 %) from wounds, 34 (17 %) from blood culture, 20 (10 %) from stool of healthy carrier and nine (4.5 %) from bronchoalveolar lavages. In this study, 83 isolates (41.5 %) were from outpatients (urine and stool specimens only), and the remaining 117 isolates (58.5) were from inpatients. By PCR technique, 181 isolates were found to be ESBL producers. blaTEM was the commonest genotype (39.2 %), followed by blaSHV (32.5 %) and blaCTX-M (30.9 %), either alone or in combination. Acinetobacter baumannii isolate had none of the ESBL genes. Eighteen (9.9 %) out of 181 isolates carried more than one type of beta-lactamase genes. Our study demonstrated rapid detection of bla (TEM, SHV, CTX-M, and OXA) in isolates belonging to Enterobacteriaceae and other nonfermenting clinical isolates using multiplex PCR. This genotypic method provided a rapid and efficient differentiation of ESBLs in the laboratory.     

Platelet-rich plasma versus corticosteroid injections in the management of patients with rotator cuff disease: A systematic review and meta-analysis

Platelet-rich plasma (PRP) is an alternative to corticosteroid (CS) injections in managing rotator cuff disease. This meta-analysis investigated differences between PRP and CS for function and pain scores in significance and minimal clinical important difference (MCID). A literature search of Ovid Cochrane Library, Medline, Embase, Epub, and Scopus was conducted from inception to October 28, 2021. Eligible studies reported patients older than 18 years with a diagnosis of rotator cuff disease. This review was registered in PROSPERO (ID: CRD42021278740). Twelve studies met eligibility criteria (n = 639) of patients receiving either PRP or CS. At short-term follow-up, a difference favored CS compared to PRP in baseline change for disability of arm, shoulder, and hand (DASH) score (MD = −5.08, 95% CI: −8.00, −2.15; p = 0.0007; I² = 0%) and simple shoulder test (SST) (MD = 1.25, 95% CI: 0.33, 2.18; p = 0.008; I² = 0%). At intermediate follow-up, a difference favored PRP to CS baseline change of the DASH score (MD = 3.41, 95% CI: 0.67, 6.15; p = 0.01; I² = 0%). At medium-term, a difference favored PRP to CS baseline change of the American Shoulder and Elbow Surgeons Shoulder (ASES) score (MD = −4.42, 95% CI: −8.16, −0.67; p = 0.02; I² = 0%). Both treatments achieved individual MCID for each score. Despite favoring CS at short-term follow-up and PRP at intermediate- and medium-term follow-up, functional and pain scores did not demonstrate any clinical difference between the two treatment modalities in management of rotator cuff disease at all follow-up periods.     

Safety and efficacy of biodegradable polymer-coated biolimus-eluting stents

BackgroundUsing drug eluting stents with a biodegradable polymer ensures that both the drug and coating are absorbed from the stent surface after completing their functions, which may reduce the need for prolonged antiplatelet therapy and decrease the risk of late stent thrombosis.ObjectivesOur study sought to compare the safety and efficacy of a biolimus-eluting stent (with biodegradable polymer) with a well-established sirolimus- or paclitaxel-eluting stent (with durable polymers).MethodsWe undertook a prospective, randomized, comparative study that included 145 patients with chronic stable coronary artery diseases or acute coronary syndromes. The patients were randomized for treatment with either biolimus-eluting (n = 62) or sirolimus/paclitaxel-eluting (n = 83) stents. The study endpoint was a composite of major adverse cardiac events (MACE) within 2 years. Angiographic follow-up was scheduled at the end of the study or earlier if clinically indicated.ResultsAt the two-year follow-up, a biodegradable polymer biolimus-eluting stent showed comparable safety and efficacy to permanent polymer DES(5[8.1%] patients in the biolimus group vs.8[9.6%] in the sirolimus/paclitaxel group, p = 0.7). The incidence of mortality, myocardial infarction, cerebrovascular accident and target lesion revascularization was similar for both stent types. Furthermore, the incidence of stent thrombosis was statistically non-significant between both the groups.ConclusionThe use of a biodegradable polymer-based DES (biolimus-eluting) demonstrated satisfactory efficacy and safety profiles with low MACE and stent thrombosis rates up to 2 years compared with other non-biodegradable polymer-based DES.     

Micelles as potential drug delivery systems for colorectal cancer treatment

Despite the significant progress in cancer therapy, colorectal cancer (CRC) remains one of the most fatal malignancies worldwide. Chemotherapy is currently the mainstay therapeutic modality adopted for CRC treatment. However, the long-term effectiveness of chemotherapeutic drugs has been hampered by their low bioavailability, non-selective tumor targeting mechanisms, non-specific biodistribution associated with low drug concentrations at the tumor site and undesirable side effects. Over the last decade, there has been increasing interest in using nanotechnology-based drug delivery systems to circumvent these limitations. Various nanoparticles have been developed for delivering chemotherapeutic drugs among which polymeric micelles are attractive candidates. Polymeric micelles are biocompatible nanocarriers that can bypass the biological barriers and preferentially accumulate in tumors via the enhanced permeability and retention effect. They can be easily engineered with stimuli-responsive and tumor targeting moieties to further ensure their selective uptake by cancer cells and controlled drug release at the desirable tumor site. They have been shown to effectively improve the pharmacokinetic properties of chemotherapeutic drugs and enhance their safety profile and anticancer efficacy in different types of cancer. Given that combination therapy is the new strategy implemented in cancer therapy, polymeric micelles are suitable for multidrug delivery and allow drugs to act concurrently at the action site to achieve synergistic therapeutic outcomes. They also allow the delivery of anticancer genetic material along with chemotherapy drugs offering a novel approach for CRC therapy. Here, we highlight the properties of polymeric micelles that make them promising drug delivery systems for CRC treatment. We also review their application in CRC chemotherapy and gene therapy as well as in combination cancer chemotherapy.     

Mechanical Properties of Orifice Preflaring Nickel-titanium Rotary Instrument Heat Treated Using T-Wire Technology

Introduction

This study examined whether the use of T-Wire heat treatment enhanced the resistance to torsional force, cyclic fatigue, and bending stiffness of orifice preflaring nickel-titanium instruments.

Cyclosporine and mycophenolate mofetil 48 hours before renal transplantation enables the use of low cyclosporine doses and achieves better graft function

Reducing calcineurin-inhibitor induced nephrotoxicity and simultaneously avoiding long-term side effects are desirable goals in renal transplantation. We examined the hypothesis that administration of cyclosporine and mycophenolate mofetil (MMF) 48 hours before renal transplantation allows reduction in the target cyclosporine C2 concentration, thus decreasing toxicity and improving graft function. We enrolled 80 kidney recipients in a single-center study comparing 2 cyclosporine-based protocols. Group I patients (n = 40) received a standard dose of cyclosporine (blood cyclosporine C2, 800-1500 ng/mL) with MMF and standard doses of corticosteroids. Group II patients (n = 40) were treated with a low dose of cyclosporine (blood cyclosporine C2, 450-800 ng/mL) and MMF plus low doses of corticosteroids after induction 48 hours before surgery with cyclosporine and MMF. Patient (97.5% vs 100%) and graft survivals (92.5% vs 95%) at 1 year were not different between the groups, although patients in group II experienced significantly fewer acute rejection episodes (10% vs 30%; P < .01). Delayed graft function occurred less often among group I than group II (17.5 vs 20%), but the difference was not significant. Graft function at 1 year was significantly better among group II (serum creatinine 1.31 vs 1.64 mg/dL and creatinine clearance 63 mL/min versus 47 mL/min; P < .05). We concluded that administration of cyclosporine and MMF 48 hours before renal transplantation allowed the safe effective use of low target C2 cyclosporine concentrations, enabling an early decrease in cyclosporine dose. These preliminary results indicated better 1-year graft function compared with the normal cyclosporine dose regimen.     

Overexpression of G1-S cyclins and cyclin-dependent kinases during multistage human pancreatic duct cell carcinogenesis.

PURPOSE: Molecular analysis of pancreatic intraepithelial neoplasia lesions and ductal adenocarcinoma suggested a multistage paradigm for pancreatic duct cell carcinogenesis. This study investigated the molecular basis for the neoplastic duct cells in this pancreatic intraepithelial neoplasia-carcinoma sequence to acquire progressive enhancement of their proliferative potential. EXPERIMENTAL DESIGN: Using tissue microarray blocks containing 15 to 40 pancreatic intraepithelial neoplasia lesions and ductal adenocarcinoma of pancreas, we studied by immunohistochemistry the expression profiles of cyclins and cyclin dependent kinases (CDKs) that regulate the G1-S cell cycle checkpoints. The role of cyclins D3 and D1 in three pancreatic cancer cell lines was investigated using specific short interfering RNA technique. RESULTS: Cyclin D3 overexpression was noted the earliest in pancreatic intraepithelial neoplasia-1A and was prevalent in 90% to 100% of high-grade pancreatic intraepithelial neoplasias and ductal cancer. Cyclin A overexpression was also noted early and reached 50% to 100% of high-grade pancreatic intraepithelial neoplasias and cancer, but the percentage of abnormal duct cells showing overexpression of cyclin A was significantly lower than cyclin D3. Cyclin E overexpression occurred in 20% to 25% of high-grade pancreatic intraepithelial neoplasias and in 75% of ductal carcinoma. Cyclin D1 demonstrated the lowest frequency of overexpression that occurred late. CDK2 and CDK4 overexpression was also noted in early pancreatic intraepithelial neoplasias and progressively increased to reach 60% to 75% in carcinoma. The down-regulation of cyclin D3 mRNA and protein levels using specific short interfering RNA resulted in growth inhibition of pancreatic cancer cell lines. CONCLUSION: The results provide additional insight into the mechanism of G1-S cell cycle checkpoints deregulation during stepwise pancreatic duct cell carcinogenesis, and suggest a p16-independent role for cyclin D3 in deregulating the G1 cell cycle checkpoints during early stages of pancreatic duct cell carcinogenesis.