Integrated Bioinformatics Analysis Confirms the Diagnostic Value of Nourin-Dependent miR-137 and miR-106b in Unstable Angina Patients

The challenge of rapidly diagnosing myocardial ischemia in unstable angina (UA) patients presenting to the Emergency Department (ED) is due to a lack of sensitive blood biomarkers. This has prompted an investigation into microRNAs (miRNAs) related to cardiac-derived Nourin for potential diagnostic application. The Nourin protein is rapidly expressed in patients with acute coronary syndrome (ACS) (UA and acute myocardial infarction (AMI)). MicroRNAs regulate gene expression through mRNA binding and, thus, may represent potential biomarkers. We initially identified miR-137 and miR-106b and conducted a clinical validation, which demonstrated that they were highly upregulated in ACS patients, but not in healthy subjects and non-ACS controls. Using integrated comprehensive bioinformatics analysis, the present study confirms that the Nourin protein targets miR-137 and miR-106b, which are linked to myocardial ischemia and inflammation associated with ACS. Molecular docking demonstrated robust interactions between the Nourin protein and miR137/hsa-miR-106b, involving hydrogen bonds and hydrophobic interactions, with -10 kcal/mol binding energy. I-TASSER generated Nourin analogs, with the top 10 chosen for structural insights. Antigenic regions and MHCII epitopes within the Nourin SPGADGNGGEAMPGG sequence showed strong binding to HLA-DR/DQ alleles. The Cytoscape network revealed interactions of -miR137/hsa-miR--106b and Phosphatase and tensin homolog (PTEN) in myocardial ischemia. RNA Composer predicted the secondary structure of miR-106b. Schrödinger software identified key Nourin-RNA interactions critical for complex stability. The study identifies miR-137 and miR-106b as potential ACS diagnostic and therapeutic targets. This research underscores the potential of miRNAs targeting Nourin for precision ACS intervention. The analysis leverages RNA Composer, Schrödinger, and I-TASSER tools to explore interactions and structural insights. Robust Nourin-miRNA interactions are established, bolstering the case for miRNA-based interventions in ischemic injury. In conclusion, the study contributes to UA and AMI diagnosis strategies through bioinformatics-guided exploration of Nourin-targeting miRNAs. Supported by comprehensive molecular analysis, the hypoxia-induced miR-137 for cell apoptosis (a marker of cell damage) and the inflammation-induced miR-106b (a marker of inflammation) confirmed their potential clinical use as diagnostic biomarkers. This research reinforces the growing role of miR-137/hsa-miR-106b in the early diagnosis of myocardial ischemia in unstable angina patients.

Impedimetric Sensors for Cyclocreatine Phosphate Determination in Plasma Based on Electropolymerized Poly(o-phenylenediamine) Molecularly Imprinted Polymers

Cyclocreatine and its water-soluble derivative, cyclocreatine phosphate (CCrP), are potent cardioprotective drugs. Based on recent animal studies, CCrP, FDA-awarded Orphan Drug Designation, has a promising role in increasing the success rate of patients undergoing heart transplantation surgery by preserving donor hearts during transportation and improving the recovery of transplanted hearts in recipient patients. In addition, CCrP is under investigation as a promising treatment for creatine transporter deficiency, an X-linked inborn error resulting in a poor quality of life for both the patients and the caregiver. A newly designed molecularly imprinted polymer (MIP) material was fabricated by the anodic electropolymerization of o-phenylenediamine on screen-printed carbon electrodes and was successfully applied as an impedimetric sensor for CCrP determination to dramatically reduce the analysis time during both the clinical trial phases and drug development process. To enhance the overall performance of the proposed sensor, studies were performed to optimize the electropolymerization conditions, incubation time, and pH of the background electrolyte. Scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry were used to characterize the behavior of the developed ultrathin MIP membrane. The CCrP-imprinted polymer has a high recognition affinity for the template molecule because of the formation of 3D complementary cavities within the polymer. The developed MIP impedimetric sensor had good linearity, repeatability, reproducibility, and stability within the linear concentration range of 1 × 10^-9 to 1 × 10^-7 mol/L, with a low limit of detection down to 2.47 × 10^-10 mol/L. To verify the applicability of the proposed sensor, it was used to quantify CCrP in spiked plasma samples.

Nourin-Dependent miR-137 and miR-106b: Novel Biomarkers for Early Diagnosis of Myocardial Ischemia in Coronary Artery Disease Patients

Background: Although cardiovascular imaging techniques are widely used to diagnose myocardial ischemia in patients with suspected stable coronary artery disease (CAD), they have limitations related to lack of specificity, sensitivity and “late” diagnosis. Additionally, the absence of a simple laboratory test that can detect myocardial ischemia in CAD patients, has led to many patients being first diagnosed at the time of the development of myocardial infarction. Nourin is an early blood-based biomarker rapidly released within five minutes by “reversible” ischemic myocardium before progressing to necrosis. Recently, we demonstrated that the Nourin-dependent miR-137 (marker of cell damage) and miR-106b-5p (marker of inflammation) can diagnose myocardial ischemia in patients with unstable angina (UA) and also stratify severity of ischemia, with higher expression in acute ST-segment elevation myocardial infarction (STEMI) patients compared to UA patients. Minimal baseline-gene expression levels of Nourin miRNAs were detected in healthy subjects. Objectives: To determine: (1) whether Nourin miRNAs are elevated in chest pain patients with myocardial ischemia suspected of CAD, who also underwent dobutamine stress echocardiography (DSE) or ECG/Treadmill stress test, and (2) whether the elevated levels of serum Nourin miRNAs correlate with results of ECHO/ECG stress test in diagnosing CAD patients. Methods: Serum gene expression levels of miR-137, miR-106b-5p and their corresponding molecular pathway network were measured blindly in 70 enrolled subjects using quantitative real time PCR (qPCR). Blood samples were collected from: (1) patients with chest pain suspected of myocardial ischemia (n = 38) both immediately “pre-stress test” and “post-stress test” 30 min. after test termination; (2) patients with acute STEMI (n = 16) functioned as our positive control; and (3) healthy volunteers (n = 16) who, also, exercised on ECG/Treadmill stress test for Nourin baseline-gene expression levels. Results: (1) strong correlation was observed between Nourin miRNAs serum expression levels and results obtained from ECHO/ECG stress test in diagnosing myocardial ischemia in CAD patients; (2) positive “post-stress test” patients with CAD diagnosis showed upregulation of miR-137 by 572-fold and miR-106b-5p by 122-fold, when compared to negative “post-stress test” patients (p < 0.001); (3) similarly, positive “pre-stress test” CAD patients showed upregulation of miR-137 by 1198-fold and miR-106b-5p by 114-fold, when compared to negative “pre-stress test” patients (p < 0.001); and (4) healthy subjects had minimal baseline-gene expressions of Nourin miRNAs. Conclusions: Nourin-dependent miR-137 and miR-106b-5p are promising novel blood-based biomarkers for early diagnosis of myocardial ischemia in chest pain patients suspected of CAD in outpatient clinics. Early identification of CAD patients, while patients are in the stable state before progressing to infarction, is key to providing crucial diagnostic steps and therapy to limit adverse cardiac events, improve patients’ health outcome and save lives.

Nourin-Dependent miR-137 and miR-106b: Novel Early Inflammatory Diagnostic Biomarkers for Unstable Angina Patients

BACKGROUND

Currently, no blood biomarkers exist that can diagnose unstable angina (UA) patients. Nourin is an early inflammatory mediator rapidly released within 5 min by reversible ischemic myocardium, and if ischemia persists, it is also released by necrosis. Nourin is elevated in acute coronary syndrome (ACS) patients but not in symptomatic noncardiac and healthy subjects. Recently, circulating microRNAs (miRNAs) have been established as markers of disease, including cardiac injury and inflammation.

OBJECTIVES

To profile and validate the potential diagnostic value of Nourin-dependent miR-137 (marker of cell damage) and miR-106b-5p (marker of inflammation) as early biomarkers in suspected UA patients and to investigate the association of their target and regulating genes.

METHODS

Using Nourin amino acid sequence, an integrated bioinformatics analysis was conducted. Analysis indicated that Nourin is a direct target for miR-137 and miR-106b-5p in myocardial ischemic injury. Two linked molecular networks of lncRNA/miRNAs/mRNAs were also retrieved, including CTB89H12.4/miR-137/FTHL-17 and CTB89H12.4/miR-106b-5p/ANAPC11. Gene expression profiling was assessed in serum samples collected at presentation to an emergency department (ED) from: (1) UA patients (n = 30) (confirmed by invasive coronary angiography with stenosis greater than 50% and troponin level below the clinical decision limit); (2) patients with acute ST elevation myocardial infarction (STEMI) (n = 16) (confirmed by persistent ST-segment changes and elevated troponin level); and 3) healthy subjects (n = 16).

RESULTS

Gene expression profiles showed that miR-137 and miR-106b-5p were significantly upregulated by 1382-fold and 192-fold in UA compared to healthy, and by 2.5-fold and 4.6-fold in STEMI compared to UA, respectively. Healthy subjects showed minimal expression profile. Receiver operator characteristics (ROC) analysis revealed that the two miRNAs were sensitive and specific biomarkers for assessment of UA and STEMI patients. Additionally, Spearman's correlation analysis revealed a significant association of miRNAs with the associated mRNA targets and the regulating lncRNA.

CONCLUSIONS

Nourin-dependent gene expression of miR-137 and miR-106b-5p are novel blood-based biomarkers that can diagnose UA and STEMI patients at presentation and stratify severity of myocardial ischemia, with higher expression in STEMI compared to UA. Early diagnosis of suspected UA patients using the novel Nourin biomarkers is key for initiating guideline-based therapy that improves patients' health outcomes.

Abstract 13311: Cyclocreatine Phosphate: A Novel Mechanism for Preventing Development of Heart Failure

Introduction: Demand ischemia causes irreversible myocardial injury (MI) through exhaustion of cellular adenosine triphosphate (ATP). We demonstrated that enhancing myocardial ATP stores during ischemia using Cyclocreatine Phosphate (CCrP), prevents myocardial injury and maintains cardiac contractility in a variety of models. The FDA has granted CCrP Orphan Drug Status with the designation of “ Prevention of Ischemic Injury to Enhance Cardiac Graft Recovery and Survival in Heart Transplantation ” .

Hypothesis: CCrP administration will prevent ischemic injury and the subsequent development of heart failure in standard isoproterenol (ISO) rat model.

Methods: 20 male Wistar rats (180-220 g) were used: ISO/saline (n=6), ISO/CCrP 0.8 gm/kg/day (n=5), control/saline (n=5), control/CCrP 0.8 gm/kg/day (n=4). Rats were injected S.C. with ISO for two consecutive days at doses of 85 and 170 mg/kg/day, respectively, then left for 2 weeks. CCrP and saline were injected IP (1 ml) 24 hours and 1 hour before ISO administration, then daily for 2 weeks. Serum CK-MB (U/L) measured 24 hours after last ISO injection. After 14 days, ECHO analysis for Ejection Fraction (EF%) was conducted, as well as heart weight (mg), fibrosis and deposition of collagen. Mean ± S.E.M and one-way ANOVA analysis were used.

Results: Table I shows evidence of MI after 24 hours by high elevation of CK-MB in ISO rats, while significant protection was seen in ISO/CCrP rats. After 14 days, ISO/CCrP rats showed normal EF% and heart weight, while ISO/saline rats showed significant drop in EF% and an increase in heart weight. Blinded pathology indicated marked increase of fibrin and collagen deposition in ISO/saline rats, which were not seen in ISO/CCrP rats. Healthy rats treated with CCrP for 14 days, showed no toxicity in liver and renal function.

Conclusions: The bioenergetic Cyclocreatine Phosphate is a promising first-in-class cardio-protective drug that prevents the development of heart failure due to ischemia.

Cyclocreatine protects against ischemic injury and enhances cardiac recovery during early reperfusion

Introduction: A critical mechanism of how hypoxia/ischemia causes irreversible myocardial injury is through the exhaustion of adenosine triphosphate (ATP). Cyclocreatine (CCr) and its water-soluble salt Cyclocreatine-Phosphate (CCrP) are potent bioenergetic agents that preserve high levels of ATP during ischemia. Areas covered: CCr and CCrP treatment prior to the onset of ischemia, preserved high levels of ATP in ischemic myocardium, reduced myocardial cell injury, exerted anti-inflammatory and anti-apoptotic activities, and restored contractile function during reperfusion in animal models of acute myocardial infarction (AMI), global cardiac arrest, cardiopulmonary bypass, and heart transplantation. Medline and Embase (1970 - Feb 2019), the WIPO databank (up to Feb 2019); no language restriction. Expert opinion: This review provides the basis for a number of clinical applications of CCrP and CCr to minimize ischemic injury and necrosis. One strategy is to administer CCrP to AMI patients in the pre-hospital phase, as well as during, or after Percutaneous Coronary Intervention (PCI) procedure to potentially achieve protection of the myocardium, reduce infarcted-size, and, thus, limit the progression to heart failure. Another clinical applications are in predictable myocardial ischemia where pretreatment with CCrP would likely improve outcome and quality of life of patients who will undergo cardiopulmonary bypass for coronary revascularization and end-stage heart failure patients scheduled for heart transplantation.

CYCLOSPORIN H: A NOVEL ANTI-INFLAMMATORY THERAPY FOR INFLUENZA FLU PATIENTS

Relatively little is known about the inflammatory mediators and mechanisms that drive the progression of influenza flu infection to cytokine storm, lung dysfunction, organ failure, and ultimately death. Vaccines and antiviral medications cannot control the excessive host inflammatory response associated with severe influenza flu infection. Studies by Elgebaly et al demonstrated the rapid release of a potent inflammatory mediator, recently named Nourin, by local mammalian tissues in response to injury and infection. Nourin is a formyl peptide that acts through the formyl peptide receptor (FPR) on phagocytic leukocytes. As an initial signal in the innate immunity, Nourin stimulates leukocyte chemotaxis, induces acute and chronic inflammation, and stimulates the release of a number of the cytokine storm mediators from monocytes, neutrophils and endothelial cells. Furthermore, Nourin detected in plasma samples from patients with severe influenza infection was much higher compared to moderate influenza. The Nourin antagonist, Cyclosporin H, is a potent anti-inflammatory compound, which acts as a specific competitive antagonist of formyl peptides on the formyl peptide receptor (FPR) on phagocytic: leukocytes. Cyclosporin H completely blocked neutrophil chemotaxis induced by: (a) the standard formyl peptide, f-MLF, (b) the Staphylococcus aureus bacteria-derived formyl peptide Phenol-soluble modulins, such as PSM3a, plus(c) the host-derived Nourin released by: (1) cultured epithelial cells infected with the PR8 HINI influenza virus for 6.to 24 hours, (2),Nourin detected in the serum of mouse model of HINI Swine flu influenza infection for 6 hours , along with (3) Nourin detected in plasma samples collected from severe and moderate influenza pa- tients. Furthermore, in-vivo treatment by Cyclosporin H in the mouse model of HINI Swine flu influenza infection for 5 days markedly reduced lung inflammation and endothelial cell damage. Thus, two clinical applications for Nourin and its antagonist Cyclosporin H are proposed: Diagnostic Application: The blood Nourin test can be used as a key inflammatory biomarker for "early" detection and monitoring of influenza flu patients proceeding to hyperactive inflammation and, thus, permitting early crucial anti-inflammatory therapy. Therapeutic Application: Cyclosporin H will specifically block Nourin as an important initial stimulant of cytokine mediators, and thus can control the development and progression of cytokine storm plus organ inflammation, which usually initiates 3 to 8 days post influenza. Since Cyclosporin H does not target the virus,, it will not develop drug resistance,and will reduce the host uncontrpolled inflammatory response, induced by both new strains of flu viruses and existing viruses with mutations.

Enhancement of cardiac function by cyclocreatine in models of cardiopulmonary bypass

This study tests the hypothesis that the administration of cyclocreatine prior to global ischemia enhances recovery of cardiac function during reperfusion. Two models were used. First, in a Langendorff-working heart model of normothermic cardioplegic arrest, rats (n = 6 per group) were injected intravenously with saline or cyclocreatine (600, 300, or 150 mg/kg). After 30 min or 2 h, hearts were excised and perfused in the Langendorff mode for 5 min and then in the working heart mode for 20 min. Normothermic arrest was induced by infusing warm St. Thomas solution once; then hearts were kept at 37 degrees C for 40 min. Following arrest, hearts were reperfused in the Langendorff mode for 15 min and then in the working mode for 30 min. Cyclocreatine consistently produced significantly better recovery of aortic flow and cardiac output compared to that of saline hearts. Second, in an intact canine model of cold cardioplegic arrest, adult mongrel dogs (n = 3 to 6 per group) underwent aortic cross-clamping for 1 h, followed by reperfusion on bypass for 45 min and off bypass for 4 h. Dogs were injected intravenously with saline or cyclocreatine (500 mg/kg) for 1 h before experiment. Post-bypass segmental contractility and cardiac output were significantly better in cyclocreatine hearts compared to that of controls. In a limited study, after a 3 h aortic cross-clamp time, cyclocreatine hearts achieved 91% baseline function while control hearts failed after 2 h. Results of this study suggest that cyclocreatine, without inotropic or chronotropic effect, protects the heart from global ischemic injury.

Enhancement of the recovery of rat hearts after prolonged cold storage by cyclocreatine phosphate

The present study determined whether the administration of cyclocreatine phosphate (CCrP) prior to ischemia can enhance the recovery of rat hearts hypothermically preserved for a prolonged period. Rats (n = 6 per group) were injected intravenously with 1 ml saline or CCrP (500 mg/kg). After 2 hr, hearts were excised and arrested by an infusion of University of Wisconsin solution. Saline hearts were then incubated in 40 ml UW, while CCrP hearts were incubated in 40 ml UW containing 100 mg CCrP; a mixture that is now referred to as Hartford Hospital (HH) solution. After 6 hr of storage at 4 degrees C, hearts were reperfused in the Langendorff mode for 15 min and then in the working heart mode for 30 min. Results indicated that the recovery of cardiac function--measured as aortic flow, coronary flow, cardiac output, stroke volume, and stroke work--was significantly better in CCrP group (50-55% baseline) compared with that of saline hearts (20-25%). Although no difference in enzyme leakage (i.e., creatine kinase) or lactate was detected between the two groups, the increase in heart weight after the initial 6-hr storage was significantly higher in saline hearts compared with that of CCrP hearts. Results of this study support the conclusion that CCrP treatment provides improved functional recovery after prolonged hypothermic preservation.

Increased interleukin-1 activity in the injured vitamin A-deficient cornea

Injury to a vitamin A-deficient cornea leads to severe acute inflammation often culminating in ulceration. We report on possible regulatory mechanisms involved in the pathogenesis of corneal inflammation in vitamin A deficiency. Thymocyte comitogenic assay and interleukin (IL)-6 induction in corneal fibroblasts have shown that thermally injured and mechanically abraded vitamin A-deficient rat corneas produce much higher levels of an IL-1-like factor as compared with uninjured or injured, normal control corneas. This was confirmed by antibody capture enzyme immunoassay, which detected high levels of IL-1 alpha and IL-1 beta in injured vitamin A-deficient corneas. To our knowledge this is the first report describing the induction of IL-1 in the vitamin A-deficient cornea by thermal and mechanical injuries. When mechanically injured corneas were screened for chemotactic activity, they were found to contain significantly higher levels of a chemoattractant as compared with similarly injured, normal control corneas. Chemotactic activity [expressed as a percentage of a known chemotactic tripeptide, formyl-methionyl-leucyl-phenylalanine (fMLP), found in medium harvested from vitamin A-deficient corneas] averaged 58.8 +/- 8.9% (SEM) as compared with 12.6 +/- 5.4% in medium conditioned by normal corneas. Checkerboard analysis confirmed that the activity in vitamin A-deficient cornea conditioned medium was chemotactic and not chemokinetic. These results demonstrate a correlation between IL-1 levels and severity of inflammation in the injured vitamin A-deficient rat cornea.

Evidence of cardiac inflammation after open heart operations

In this study, 6 anesthetized dogs underwent global cardiac arrest for 1 hour, followed by reperfusion on bypass for 45 minutes. The hearts were then weaned off cardiopulmonary bypass and monitored for an additional 2 hours. Using modified Boyden chambers, high levels of neutrophil chemotactic activity were detected (using a checkerboard analysis) in the coronary sinus effluents obtained during cardiac arrest. The activity tended to decline during reperfusion. Assay of myeloperoxidase (a marker for neutrophils) revealed an accumulation of large numbers of neutrophils in the right (14 +/- 1.1 x 10(4) cells/g wet weight) and left (16 +/- 1 x 10(4) cells/g wet weight) ventricles after 2 hours of reperfusion. Light microscopy evaluation confirmed the presence of neutrophils, not only in the ventricles, but also in a greater number in the right and left atria. Electron microscopy study of these hearts revealed the presence of mild reversible changes, indicating good preservation of the hearts during arrest. Results of this study provide evidence for an acute inflammatory reaction that takes place after cardiac operations and suggest a role for myocardial tissues in the initiation of such a response through their release of neutrophil chemotactic factors.

The induction of anterior chamber inflammation by factors released from hydrogen peroxide-injured corneas: effect of dexamethasone and indomethacin

Studies from our laboratory have demonstrated the release of high levels of neutrophil chemotactic factors (NCF) from isolated rabbit corneas injured by hydrogen peroxide (H2O2). The purpose of the present study was to determine the biological activity of these factors and to test the hypothesis that the intracameral injection of these factors can induce inflammation of the anterior segment. Under sterile conditions, the epithelial surfaces of isolated rabbit corneas were incubated with a 300 ul mixture of glucose (G) (1mg/ml) and glucose oxidase (GO) (20 U/ml) at 37 degrees C for 6 hours. This supernatant solution was collected and a 100 ul sample containing NCF, but not H2O2, was injected into the anterior chamber of anesthetized rabbit eyes (n = 8). Anterior chamber inflammation, characterized by moderate corneal edema associated with a fibrinous anterior chamber reaction, was evident 2 and 4 hours after injection. Aqueous humor analysis revealed the presence of fibrin and a large number of neutrophils (32 +/- 5 x 10(4) cells/ml). Control eyes, on the other hand, showed normal morphology and low levels of neutrophils after the injection of 100 ul minimum essential medium (MEM) (n = 8) (1.2 +/- 0.14 x 10(4) cells/ml), G/GO mixture (n = 8) (5 +/- 0.86 x 10(4) cells/ml), or supernatant solutions collected from MEM-treated corneas (n = 8) (15 +/- 2 x 10(4) cells/ml). To determine whether the inflammatory reaction observed was due to a direct effect of the chemoattractants or mediated through stimulation of arachidonic acid (AA) metabolites, we pretreated rabbit eyes with a sterile solution of 0.1% dexamethasone (n = 8 eyes) or with a sterile solution of 3.4% indomethacin (n = 8 eyes) three times a day, for one day, prior to the injection of NCF supernatant solution. Examination 2 hours and 4 hours after injection revealed inflammation characterized by mild-to-moderate corneal edema associated with a fibrinous anterior chamber reaction was observed with or without prior treatment with AA metabolite inhibitors. No difference in the degree of inflammation was detected clinically. Results of these studies suggest that NCF released from H2O2-injured corneas can directly induce inflammation of the anterior segment, and that metabolites of AA are not mediating the observed in vivo response.

Cyclocreatine inhibits neutrophil accumulation in the myocardium of a canine model of coronary artery occlusion and reperfusion

This study tests the hypothesis that the administration of cyclocreatine before ischemia inhibits the release of neutrophil chemotactic factors from myocardial tissues and subsequently reduces neutrophil accumulation into ischemic areas. Adult mongrel dogs underwent left anterior descending coronary artery occlusion for 1 h, followed by a 2-h reperfusion. Cyclocreatine-treated dogs (n = 6) were injected intravenously with cyclocreatine solution (600 mg/kg) 1 h before the experiment and during ligation of the coronary artery. Control dogs (n = 6) were injected with saline. Neutrophil chemotactic activity was measured in plasma samples using standard modified Boyden chambers. In controls dogs, significantly elevated levels of chemotactic activity were recovered in blood samples taken during reperfusion (i.e., 2.8-3.5-fold; P < .0001) as compared to base-line activity recovered before occlusion. Preliminary biochemical characterizations revealed that the recovered chemotactic factors (via checkerboard analysis) are proteins of high molecular weight (greater than 100 kDa). Biopsy samples of control hearts showed an accumulation of a large number of neutrophils in the ischemic portions. Cyclocreatine-treated dogs, on the contrary, showed low levels of chemotactic activity during reperfusion, which correlated with the absence of neutrophils in ischemic areas. These results indicate the capability of cyclocreatine to inhibit the release of neutrophil chemotactic factors from ischemic myocardium, which subsequently prevented neutrophil accumulation.

Cardiac-derived neutrophil chemotactic factors: detection in coronary sinus effluents of patients undergoing myocardial revascularization

Recent studies from our laboratory have demonstrated the release of neutrophil chemotactic factors from isolated rabbit hearts perfused with cardioplegic solutions and from ischemic dog hearts after coronary artery occlusion for 1 hour. On the basis of these animal studies, a test is now made of the hypothesis that neutrophil chemotactic factors are released by myocardial tissues of patients who undergo surgical myocardial revascularization. By means of modified Boyden chambers, the levels of neutrophil chemotactic factors were measured in effluent collected from the coronary sinuses of six patients undergoing cardiopulmonary bypass during periods of cold cardioplegia. Plain cardioplegic solutions were also analyzed. The standard formyl-methionyl-leucyl-phenylalanine, a stimulant of neutrophil recruitment, was used as a positive control solution. Results indicated the recovery of significantly high levels of neutrophil chemotactic factors in patient samples (i.e., 128% +/- 19% of formyl-methionyl-leucyl-phenylalanine) compared with control plain cardioplegic solution (less than 5% of formyl-methionyl-leucyl-phenylalanine) (p less than 0.0001). A standard checkerboard analysis indicated that the observed activity is chemotactic (i.e., directed migration) and not chemokinetic (i.e., random migration). This study also showed that these factors are proteins of a molecular weight in excess of 300 kd and exhibit in vivo activity by recruiting neutrophils into rabbit skin. The absence of immune cell-derived chemoattractants such as interleukin-1 and leukotriene B4 in these coronary sinus effluents suggests that the observed chemotactic activity is cardiac derived. Results of this investigation therefore demonstrate the release of neutrophil chemotactic factors by ischemic human hearts during cardiopulmonary bypass.

Urinary neutrophil chemotactic factors in interstitial cystitis patients and a rabbit model of bladder inflammation

The present study investigates a possible source of inflammatory mediators involved in the pathogenesis of bladder inflammation characteristics of interstitial cystitis disease. Our tested hypothesis is that in response to injury, tissues of the urinary bladder participate in the initiation of bladder inflammation by releasing inflammatory mediators such as neutrophil chemotactic factors. Bladders of anesthetized rabbits (n = 7) were instilled with an acidic solution (pH 4.5) for 15 minutes, then washed with saline and instilled with sterile phosphate buffered saline (PBS) (pH 7.2) for an additional 45 minutes prior to sacrificing the rabbits. Control rabbits (n = 7) were instilled with sterile PBS (pH 7.2) for 15 minutes, then 45 minutes. The levels of neutrophil chemotactic factors were measured using modified Boyden chambers and rabbit peritoneal neutrophils as indicator cells. Results indicated the release of high levels of neutrophil chemotactic factors (via a checkerboard analysis) from acid-treated bladders after 15 minutes (70 +/- 4% of standard) and 45 minutes (80 +/- 7%). Electron microscopy analysis of these acid-treated bladders revealed the infiltration of a large number of neutrophils, which correlates with the recovery of neutrophil chemotactic factors. Control rabbits, on the other hand, showed low levels of chemotactic activity (less than 10 percent) and exhibited normal bladder morphology with absence of neutrophils. The glycosaminoglycan (GAG) layer was intact in both acid-treated and control bladders. High levels of neutrophil chemotactic factors were also detected in urine samples from eleven patients with interstitial cystitis (113 +/- 25%) (not due to interleukin-1 or leukotriene B4) which were not detected in urine samples from healthy volunteers (n = 9) or from thirteen control patients with bladder diseases other than interstitial cystitis. These preliminary studies indicate the capability of injured bladder tissues to release neutrophil chemotactic factors which contribute to the initiation of bladder inflammation. The presence of neutrophil chemotactic factors in urine samples of interstitial cystitis patients suggests a possible role of these mediators in the pathogenesis of the disease.

Neutrophil chemotactic factors derived from conjunctival epithelial cells: preliminary biochemical characterization

We have previously reported on the release of neutrophil chemotactic factors (NCF) from injured conjunctival tissue. The present study was designed to biochemically characterize these conjunctiva-derived chemotactic factors and determine their biological activities. Bulbar conjunctiva was surgically removed from a rabbit eye and incubated with 250 microL of minimal essential medium (MEM) for 6 hours at 37 degrees C in a 5% CO2 atmosphere. Chemotactic activity was assayed using modified Boyden chambers with rabbit peritoneal neutrophils as indicator cells. Following treatment with subtilisin protease for 90 minutes, chemotactic activity of the conjunctival factors was reduced by 74%. Similarly, activity was lost after heating at 56 degrees C for 60 minutes (41% inhibition). Using ultrafiltration techniques, we showed that the majority of the chemotactic activity remained above a 100 kilodalton filter, suggesting the existence of high molecular weight factors. We also showed that the conjunctival factors are not glycoproteins and bind to both anion and cation exchange resins. When 100 microL of conjunctival supernatant was injected in the superior tarsal conjunctiva of rabbits, significant recruitment of neutrophils was evident by 4 hours. Control rabbits injected with MEM did not show neutrophil recruitment. Results of these studies indicate that NCF from traumatized conjunctival tissue are proteins (and not glycoproteins) of high molecular weight, heat labile, exhibit anionic and cationic charges, and are active in vivo.

Neutrophil chemotactic factors in the tears of giant papillary conjunctivitis patients

This study was designed to determine the presence of neutrophil chemotactic factors in the tears of patients with giant papillary conjunctivitis (BPC) secondary to contact lenses. Chemotactic activity was measured using modified Boyden chambers and the chemoattractant formylmethionyl-leucyl-phenylalanine (f-MLP) for 100 percent response. Elevated levels of chemotactic activity were found in the tears of symptomatic patients (80.8 +/- 6.4, % f-MLP) compared with control tears of asymptomatic contact lens wearers (15.7 +/- 3.3%) and non-contact lens wearers (5.6 +/- 1.2%). Using radioimmunoassay, C5a (serum-derived chemoattractant), leukotriene-B4, and interleukin-1 (immune cell-derived chemoattractants) were not detected in the tears of symptomatic patients. The authors determined whether injured conjunctival cells participate in this process by releasing neutrophil chemotactic factors. Isolated rabbit bulbar conjunctiva incubated with culture medium for 4 and 6 hr released high levels of neutrophil chemotactic factors. The release of these factors from injured conjunctiva support the premise that physical trauma of conjunctival cells induced by contact lenses may be an important component of the pathophysiology of giant papillary conjunctivitis.

Cyclocreatine inhibits the production of neutrophil chemotactic factors from isolated hearts

This study was designed to determine the effect of cyclocreatine on the release of neutrophil chemotactic factors (NCF) from isolated rabbit hearts. We tested the hypothesis that if ischemia is important for the formation of NCF from the myocardium, then blocking (or delaying) ischemic changes with cyclocreatine should inhibit the release of NCF. Two models were used, including (1) perfusion of rabbit hearts (Langendorff apparatus) with oxygenated (95% oxygen) Krebs-Henseleit buffer (K-H buffer) containing 5% cyclocreatine for 120 minutes, and (2) incubating hearts with phosphate-buffered saline (PBS) containing 5% cyclocreatine for 120 minutes. For both models, rabbits were injected intravenously with 10 ml of 5% cyclocreatine solution 30 minutes before the animals were killed and the hearts removed. Control rabbits were injected with 5% creatine solution or saline for 30 minutes before perfusing hearts with K-H buffer or incubating with PBS. Chemotactic activity was assayed in the perfusates and supernatants using modified Boyden chambers and rabbit peritoneal neutrophils as indicator cells. The chemoattractant f-Met-Leu-Phe (f-MLP) was the positive control for a 100% response rate. Isolated hearts perfused with cyclocreatine showed significantly lower chemotactic activity (ie, 1.24 +/- 1% f-MLP; P less than 0.0001) compared to hearts perfused with K-H buffer (129 +/- 18%) or creatine (227 +/- 42%) (mean +/- standard error). Similar results were obtained using incubated hearts. Next the effect of cyclocreatine on neutrophils in the Boyden chamber was determined and it was found that it did not alter neutrophil migration, which excludes a direct inhibitory effect on the cells. Furthermore supernatant from cyclocreatine-treated hearts did not inhibit neutrophil chemotaxis to C5a, indicating absence of a chemotaxis inhibitor in this preparation. Results of these studies suggest that the observed low activity recovered in perfusate and supernatant of cyclocreatine-treated hearts is a result of reduction in the synthesis and/or release of the factors from myocardial tissues. Similar to previously established data, cyclocreatine treatment significantly preserved myocardial nucleotide levels (ie, adenosine triphosphate and creatine phosphate), which supports our hypothesis that the formation of NCF is ischemia dependent and that maintaining elevated levels of myocardial energy nucleotides reduced chemotactic factor release.

Cornea derived neutrophil chemotactic factors: intracellular synthesis and release

The present study was designed to test the hypothesis that the release of neutrophil chemotactic factors (NCF) from isolated corneas following hydrogen peroxide stimulation requires specific intracellular synthesis. For these studies, the epithelial surfaces of isolated rabbit corneas were preincubated with various inhibitors of protein synthesis (cycloheximide, 10 micrograms/ml, and puromycin, 50 micrograms/ml) and transcription (actinomycin D, 5 micrograms/ml) for 60 min prior to exposure of the corneas to glucose (G, 1 mg/ml) and glucose oxidase (GO, 20 U/ml) for 6 h at 37 degrees C. All three inhibitors decreased the levels of NCF recovered in the extracorneal fluids by 80-98%, suggesting that peroxide acts to upregulate NCF production at both the transcription and translation levels. When corneas were incubated with G/GO for 6 h at 12 degrees C or 4 degrees C instead of 37 degrees C, a reduction in the levels of NCF recovered in the supernatants was noted at 12 degrees C (46-91% inhibition) and at 4 degrees C (67-96% inhibition), suggesting that the synthesis of NCF at cold temperature was only reduced but not totally inhibited. To demonstrate that the observed reduction in chemotactic activity recovered from corneas incubated at 12 degrees C or 4 degrees C is not due to a temperature-dependent inhibition of NCF biosynthesis, but rather to a disruption of intracellular vesicular transport, temperature shift experiments were performed. Corneas were incubated with G/GO overnight at 12 degrees C or 4 degrees C prior to shifting to 37 degrees C for an additional 6 h.(ABSTRACT TRUNCATED AT 250 WORDS)

The release of a neutrophil chemotactic factor from UV-B irradiated rabbit corneas in vitro

Rabbit corneas were isolated, mounted on plastic rings to form a cup and the endothelium was covered with RPMI tissue culture medium. The preparation was then irradiated with 1 J. cm-2 of 300 nm light over 1 hour and then incubated for a further two hours in the dark. The supernatant fluid was assayed for chemotactic activity toward rabbit neutrophils in an in vitro Boyden chamber assay. The results indicated that medium from irradiated corneas had a chemotactic activity that was 42% of that produced by the standard chemoattractant f-met-leu-phe, (10(-9) M) while medium from unexposed corneas and exposed medium alone had less than 3% activity. An in vivo assay using sub-epidermal injection into the back of a rabbit gave qualitatively similar results, only f-met-leu-phe and the medium from irradiated corneas causing neutrophil infiltration of the tissue. A checkerboard analysis confirmed that the activity was chemotactic rather than chemokinetic. Release of a chemotactic factor following UV-B irradiation provides a mechanism for the recruitment of neutrophils, at specific localized areas of the endothelium, that is seen after discrete in vivo irradiation. The results also confirm the importance of corneal inflammatory mediators in the development of tissue damage subsequent to exposure to toxic agents.

Neutrophil chemotactic activity in human gastric secretions

To study levels of neutrophil chemotactic activity in human gastric secretions, these secretions were collected via the endoscope during elective esophagogastroduodenoscopy. Fresh samples were then prepared for the neutrophil chemotactic assay with the use of human peripheral neutrophils in modified Boyden chambers. Mean maximum chemotactic activity was 45.8% +/- 11.2% in patients with gastric inflammation compared with only 10.1% +/- 4.2% in patients with normal results of endoscopic examination. The chemotactic factors responsible for this chemotactic activity may play a role in the recruitment of neutrophils to areas of gastric mucosal injury.

Release of chemotactic factors by veins during preparation for arterial bypass

With the use of arterial bypass release neutrophil chemotactic factors, saphenous veins were removed from dogs by means of standard surgical technique and were distended to a pressure of 200 mm Hg for 15 minutes with cold (4 degrees C) plasmalyte solution. Veins cannulated in situ and flushed with cold (4 degrees C) plasmalyte solution served as negative controls. Experimental and control flush solutions were assayed for the presence of neutrophil chemotactic factors with the use of modified Boyden chambers. Chemotactic activity from the distended vein grafts was 2.2 to 7.2 times the control value. Biologic chemotactic activity was demonstrated as well. These results suggest a role for the vein graft itself in the recruitment of neutrophils to implanted veins by releasing chemoattractants.

Cardiac derived neutrophil chemotactic factors; preliminary biochemical characterization

The purpose of this study is to investigate whether isolated hearts perfused with cardioplegic solution release inflammatory mediators such as neutrophil chemotactic factors (NCF). Three conditions were tested, including: (1) perfusion of rabbit hearts with crystalloid cardioplegic solution (4 degree C) saturated with air (95% oxygen) and containing dextrose (i.e. complete system), (2) perfusion of rabbit hearts with non-oxygenated cardioplegic solution, containing dextrose (i.e. minus oxygen system), and (3) perfusion of hearts with cold cardioplegic solution saturated with air in the absence of dextrose (i.e. minus dextrose system). At various time intervals (5 min, 1, 2, 3 and 4 h) samples of circulated perfusate were removed and assayed for the presence of NCF using modified Boyden chambers. Rabbit peritoneal neutrophils were the indicator cells. The standard chemoattractant, f-Met-Leu-Phe (f-MLP) was the positive control. High levels of neutrophil chemotactic activity were detected in perfusate of all above described hearts perfused for 4 h (i.e. 194 +/- 22% of f-MLP control--complete system, 126 +/- 13%--minus oxygen and 136 +/- 10%-minus dextrose). Histological evaluation of these hearts showed evidence of global ischemia. We also detected significant levels of NCF in effluent of hearts perfused for 5 min, 1, 2 and 3 h. Similar to perfused hearts, isolated rabbit hearts incubated for 4 h with non-oxygenated cardioplegic solution (in presence and absence of dextrose) released high levels of NCF (132 +/- 18%-intact heart; and 100 +/- 6% myocardial segments). Standard checkerboard analysis revealed that the observed activity released from these hearts is chemotactic.(ABSTRACT TRUNCATED AT 250 WORDS)

Release of neutrophil chemotactic factors from gastric tissue. Initial biochemical characterization

This study was designed to characterize neutrophil chemotactic factors released by gastric tissue. Full-thickness rabbit stomach (organ culture) was prepared and incubated in Ringer's solution at 37 degrees C. Culture supernatants were collected at 1, 2, 3, and 4 hr and assayed for neutrophil chemotactic activity in modified Boyden chambers. High levels of chemotactic activity were seen at 3 hr of incubation. Antral and fundic tissue were equally capable of producing neutrophil chemotactic activity. In addition, high levels of activity were seen from both the serosal and mucosal surfaces. Initial biochemical characterization of these gastric-derived factors revealed that: (1) a majority of the activity (80-90%) exhibited molecular weight values of greater than 300 kDa, (2) the chemotactic activity was heat stable but was partially reduced by treatment with a protease, subtilisin (37% inhibition), and (3) 70-80% of the activity in the supernatants was extracted into organic solvent (ethyl acetate). These factors may prove to be important in recruitment of neutrophils to areas of gastric injury.

Effects of sodium hypochlorite (Dakin's solution) on cells of the wound module

This study investigates the effects of sodium hypochlorite, or Dakin's solution (DS), on the function and viability of cells of the wound module (neutrophils, fibroblasts, and endothelial cells). For functional studies, the influence of DS on the in vitro migration of neutrophils was evaluated. Our data indicate that DS (2.5 x 10(-2)% to 2.5 x 10(-4)%) results in greater than 90% inhibition of the migration of both stimulated and nonstimulated neutrophils. Electron microscopy and trypan blue evaluation of neutrophils exposed to DS at these concentrations revealed normal structural features, which indicates that the observed reduction in neutrophil migration is not a result of cell death. In contrast to neutrophils, cultured fibroblasts and endothelial cells exposed to DS (2.5 x 10(-2)% or 2.5 x 10(-3)%) for 30 minutes show marked cell injury characterized by convoluted nuclei, cytoplasmic vacuolization, dilated endoplasmic reticulum, and swollen mitochondria on electron microscopy. These data suggest that DS, even at very dilute concentrations, is toxic to cells of the wound module. We therefore recommend abandonment of the use of DS in open wounds.

Inflammatory mediators in alkali-burned corneas: preliminary characterization

Leukocyte chemotactic factors (LCF) are important inflammatory mediators which activate and recruit leukocytes from the circulation into sites of tissue damage. These factors were recently detected in the tear fluid of inflamed eyes induced by alkali burn. It remains unclear, however, whether the detected LCF are released from injured corneal tissues or leaked from the circulation. Using a corneal cup model developed in our laboratory, we began examining the capability of corneal tissues to produce LCF in response to alkali injury. We also evaluated the influence of citric acid on the production of LCF from corneas preinjured by the alkali sodium hydroxide (NaOH). For these studies, the epithelial surfaces of corneas isolated from bovine and human eyes were exposed to 1N NaOH for 35 seconds at room temperature. The NaOH was then removed and the epithelial surfaces washed once with buffer and incubated with culture medium for 1, 2, 4, and 6 hours at 37 degrees C/5% CO2 atmosphere. Our results showed that (1) NaOH2 induced corneal epithelial cell injury ranging from cell discoloration and moderate damage of the upper half of the epithelium (1-4 hrs) to total destruction of the epithelium (6 hrs); (2) NaOH-injured corneas (2 hr incubation post injury) produced significant levels of chemotactic activity (via checkerboard analysis) specific for neutrophils (115% maximum chemotactic response [MCR]) and mononuclear cells (94% MCR); (3) preliminary characterization of these factors revealed that they are protease and heat sensitive, extractable by organic solvents, and possess molecular weight values greater than 100,000 daltons; and (4) incubation of NaOH-pretreated corneas with 0.01% citric acid for 2 hours markedly inhibited the production of LCF for both neutrophils (98% inhibition) and mononuclear cells (91% inhibition). Results of these studies indicate that alkali-burned bovine and human corneas generate leukocyte chemoattractants which differ in their biochemical characteristics from previously known low molecular weight chemotactic factors such as C5a, interleukin-1, or leukotriene B4.

Characterization of neutrophil and monocyte specific chemotactic factors derived from the cornea in response to hydrogen peroxide injury

To unravel the contributions of corneal tissue in endocular inflammation, we examined the capability of corneal endothelial cells (CECs) to release leukocyte chemotactic factors (LCFs) following injury induced by the leukocyte product hydrogen peroxide. Hydrogen peroxide (H2O2) was chemically generated by the interactions of glucose and glucose oxidase prepared in serum-free minimal essential medium (MEM). For these studies, endothelial surfaces of isolated bovine corneas were incubated with glucose (1 mg/ml) and glucose oxidase (20 U/ml) for 4, 6, and 10 hours at 37 C/in a 5% CO2 atmosphere. Supernatants were then removed and assayed for bovine neutrophil or mononuclear cell chemotactic activity. C5 fragment was our positive control for 100% chemotactic response. Corneas were also fixed in buffered formalin for histopathologic evaluation. Results of these studies indicated that 1) 6-hour interactions of the glucose (G)/glucose oxidase (GO) mixture with endothelial surfaces resulted in both endothelial cell injury (cytoplasmic vacuolization and convoluted nuclei) and production of chemotactic factors (via checkerboard analysis) specific for both neutrophils (58% maximum chemotactic response [MCR]) and mononuclear cells (75% MCR); 2) control corneas treated with either G or GO for 4 and 6 hours produced low levels of LCFs (5-15% MCR); 3) preliminary molecular weight characterization of cornea-derived LCFs obtained from corneas incubated with G/GO for 6 hours revealed the detection of chemotactic activity specific for mononuclear cells in two major fractions, one near the void volume (greater than 130,000 daltons) and one near the elution volume (less than or equal to 10,000-15,000 daltons). Chemotactic activity specific for neutrophils was detected only in one major fraction near the elution volume (less than or equal to 10,000-15,000 daltons); and 4) the production of these LCFs by isolated corneas was significantly inhibited, in a dose-response fashion, when the enzyme catalase (1200-6000 U/ml) was added to corneas incubated with G/GO for 6 hours. To investigate whether isolated CECs were capable of producing LCFs in response to G/GO injury, the authors incubated cultured bovine CECs with G/GO for 3, 6, and 20 hours at 37 C in a 5% CO2 atmosphere. Similar to isolated corneas, cultured CECs incubated with G/GO for 6 hours produced significant levels of LCFs specific for neutrophils (67% MCR) and mononuclear cells (75% MCR). Furthermore, the addition of catalase (3000 U/ml) to corneas incubated with G/GO for 6 hours markedly reduced the production of LCFs. These in vitro studies suggest that corneal cells and/or corneal matrix may play important roles in the initiation and amplification of endocular inflammation in vivo by elaborating factors that control leukocyte influx to the anterior chamber region.

Reversal of gamma-radiation-induced leukemogenesis in mice by immunomodulation with thiabendazole and dinitrofluorobenzene

The effect of thiabendazole (TBZ) and dinitrofluorobenzene (DNFB) on radiation-induced leukemogenesis was investigated in the C57BL/6 mouse model. Administration of TBZ-DNFB during, post, or during and post irradiation successfully blocked leukemogenesis, as indicated by the absence of leukemia blast cells in thymus and peripheral blood, as well as prevented thymic lymphoma. TBZ-DNFB treatment prevented the development of leukemia when studies were terminated both after 7 months of last irradiation (disease fully developed) and after 5 months of last irradiation (disease in the process of development). This TBZ-DNFB treatment also resulted in a significant increase in survival.

An in vitro model of leukocyte mediated injury to the corneal epithelium

To enhance efforts directed at unraveling the role and mechanisms of leukocytes in mediating injury to corneal epithelium, an isolated bovine corneal cup was developed and evaluated. Bovine peripheral leukocytes and lysates were added to the corneal epithelial surface of isolated cornea for various periods after which the degree of morphologic changes and cell damage were assessed using light and electron microscopy. Results of these studies indicate that leukocyte/epithelial cell interactions are characterized by five successive stages: (1) leukocyte adhesion to superficial layer of the epithelium, (2) leukocyte penetration beneath the superficial epithelium, (3) epithelial cell injury, (4) leukocyte phagocytosis of killed epithelial cells and (5) ulceration and total destruction of the full thickness of the epithelial layer. The above sequence appears to be both time and dose dependent; that is epithelial cells exposed to leukocytes for short periods (5-60 minutes) or to low dose levels (10(5) - 10(7) cells/ml) shows leukocyte adhesion and penetration beneath the superficial layer of the epithelium, (stage 1 and 2), while longer exposures (2-3 hours) or higher numbers of leukocytes (10(7) - 10(8) cells/ml), leads to deeper penetration of epithelium by leukocytes and epithelial injury (Stages 3,4,and 5). We also observed that direct contact of intact leukocytes with epithelial cells is apparently necessary to induce this type of injury. These findings demonstrate the ability of leukocytes to destroy corneal epithelial cells and the value of this new ocular model for studies of the basic immunology of ocular inflammation.

Leukocyte-mediated injury to corneal endothelial cells. A model of tissue injury

Although leukocyte-mediated cell injury has long been suggested as a major mechanism of general tissue injury in acute and chronic inflammation, only limited data have been developed to directly implicate leukocytes in ocular tissue injury. In an effort to unravel the role and mechanisms of leukocyte-mediated injury to the cornea, an isolated corneal cup model was developed. For this model, peripheral bovine leukocytes were added to isolated bovine corneal cultures (corneal cup) in vitro, after which endothelial cell damage and death were evaluated morphologically. In general, corneal endothelial cell swelling was observed within 5-10 minutes after leukocyte exposure, followed by detachment of the corneal endothelium at a 30-75-minute interval. Grossly, the detached endothelium appeared as a floating sheet. Using trypan blue dye exclusion, cells in the sheet were found to be nonviable. When examined ultrastructurally, the sheet was found to consist of leukocytes and endothelial cell debris. Light-microscopic examination of the corneal cup at 5-10 minutes after leukocyte action demonstrated extensive endothelial cell damage, as indicated by cell membrane thickening, cytoplasmic vacuolization, and changes in nuclear shape. These changes in the endothelial cells were confirmed by electron microscopy. Vacuolization and swelling of the endothelium appeared as the first changes, induced by leukocyte interactions with the endothelial cell layer. In general, the endothelial cell nucleus became convoluted, mitochondria swelled, and the endoplasmic reticulum became dilated. These changes become more pronounced as the endothelial cells become detached from the underlying Descemet's membrane. Leukocyte interaction with corneal epithelium, on the other hand, did not result in cell detachment, but only cell damage. These studies demonstrate the ability of leukocytes to denude Descemet's membrane of endothelial cells and destroy corneal endothelial cells in vitro. They also suggest that the corneal cup model system will enhance both morphologic and biochemical evaluation of the mechanisms and consequences of leukocyte-mediated injury to the cornea, and thereby provide new insights into the mechanisms of endocular inflammation and tissue injury in vivo.

Thiabendazole-induced suppression of renal damage in a murine model of autoimmune disease

The present study was designed to compare the efficacy of thiabendazole (TBZ) with that of levamisole in the treatment of murine lupus. Both drugs were given in the presence of the T-dependent antigen dinitrofluorobenzene (DNFB). Female NZB/NZW F1 mice 2 months of age were treated with TBZ + DNFB, levamisole + DNFB, and drug solvents, once a week, from 2 through 9 months of age. All mice were then left without further treatment for an additional 2 months. TBZ/DNFB treatment has significantly reduced proteinuria, glomerular deposition of immunoglobulins and complement components, and development of the proliferative glomerulonephritis characteristic of untreated NZB/NZW mice. Levamisole/DNFB treatment, on the other hand, had little to no effect on the course of the disease when compared with untreated NZB/NZW mice. These studies clearly demonstrate the effectiveness of the TBZ/antigen therapy in maintaining renal function in autoimmune diseased mice.