A Rare Case of Aggressive Infective Endocarditis Due to Corynebacterium striatum.

Corynebacterium striatum is considered a rare pathogen in infective endocarditis (IE). C. striatum is a Gram-positive facultative anaerobic bacterium found in the environment and human flora. It is part of the microbiota of the skin and nasal mucosa of humans and has been increasingly reported as the etiologic agent of community-acquired and nosocomial diseases. A 91-year-old female patient was admitted to our clinic with complaints of increased fatigue for a week. Transthoracic echocardiography revealed a labile, echogenic appearance on the mitral valve that may be consistent with infective endocarditis, causing mitral regurgitation. Transesophageal echocardiography (TEE) confirmed this finding on the same day. In three-dimensional (3D) TEE, there was an oval mass of 1.9 cm × 1.1 cm at the level of the P2 scallop of the posterior mitral leaflet, and 1.0 cm of mobile vegetation was observed on it. Three serial blood cultures from peripheral vessels identified C. striatum. Antibiotic treatment of the patient was started with daptomycin 1 × 750 mg and meropenem 3 × 1 g. The cardiology team advised the patient to undergo early surgery, but the patient declined, and the case was followed up medically. On the 10th follow-up day, the patient had a speech disorder. Cerebral computed tomographic angiography showed an appearance compatible with a septic embolism in the left main cerebral artery. The patient's condition worsened throughout follow-ups, and she died on day 12. The purpose of presenting this case is to emphasize the importance of Corynebacterium species, which is a cause of rare native valve infectious endocarditis, and to show the difficulties in its treatment.

The relation between left ventricular systolic function parameters and preceding or prepreceding beat-to-beat distance in patients with atrial fibrillation: an echocardiographic study.

We aimed at investigating the relation between left ventricle (LV) systolic parameters and beat-to-beat distances and also whether this relation is different in heart failure with reduced ejection fraction (HFrEF) patients with atrial fibrillation (AF). The relation between peak velocity in left ventricular outflow (VLVOT), left atrioventricular plane displacement (LAVPD) or peak systolic tissue Doppler velocity of lateral mitral annulus (Lateral S') and preceding beat-to-beat distance (RR1) or prepreceding beat-to-beat distance (RR2) were analyzed by linear regression analysis. From this analysis, three parameters were obtained: slope of regression line, constant of regression line, and square of regression coefficient (r2) of linear relation. In the group with HFrEF, the slope and r2 values of the regression line showing the relationship between the RR1 interval and VLVOT, LAVPD, and Lateral S' values were higher and the constants were lower. In the Kendall rank correlation analysis, the slope, constant, and r2 values of the regression analysis between RR1 interval and VLVOT or Lateral S' were in significant correlation with LVEF. The r2 of VLVOT-RR1 analysis, slope of this analysis, and slope of Lateral S'-RR1 regression line values were mostly predictive for detecting HFrEF. It was concluded that the novel parameters obtained by linear regression analysis between LV systolic function parameters and RR1 interval, but not RR2, might be beneficial for evaluating systolic heart failure in patients with AF. They might have potential for future research about the physiopathology of heart and prognosis in patient with AF.

Comparison of warm fluid and cold fluid resuscitation during uncontrolled hemorrhagic shock model in rats.

BACKGROUND: This study was designed to compare the effects of resuscitation with cold and warm fluid on survival time, rate and volume of hemorrhage, hemodynamics, hypothermia, coagulopathy, acid-base balance, hematocrit, lactate, and base deficit during uncontrolled hemorrhagic shock (HS) model in rats. METHODS: HS model was created with splenic vascular and parenchymal injury in 29 rats under ketamine and xylazine anesthesia. Thirty minutes after the hemorrhage, the rats were randomized to receive 14.5 mL/kg 0.9% sodium chloride solution at either 24ºC (Group 1; n=9) or 4ºC (Group 2; n=10) for 20 minutes. Groups 1 and 2 were compared with group that did not receive fluid (Group 3; n=10). Statistical data were represented as mean±SD. SPSS for Windows, Version 15.0 (SPSS, Inc., Chicago, IL, USA) software, Bonferroni-adjusted Mann-Whitney U test and Kaplan-Meier procedure were used to perform statistical data analysis. P value of ≤0.05 was considered statistically significant. RESULTS: Cold fluid resuscitation decreased survival time due to increased rate and volume of hemorrhage, acidosis, hypothermia, lactate, and base deficit and decreased blood pressure and hematocrit. CONCLUSION: There is a great need for further experimental and clinical trials on fluid resuscitation in trauma in order to define which fluid should be administered, temperature of the fluid, quantity to be delivered, and duration.

Neuropeptide Y3-36 incorporated into PVAX nanoparticle improves functional blood flow in a murine model of hind limb ischemia.

We generated a novel nanoparticle called PVAX, which has intrinsic antiapoptotic and anti-inflammatory properties. This nanoparticle was loaded with neuropeptide Y3-36 (NPY3-36), an angiogenic neurohormone that plays a central role in angiogenesis. Subsequently, we investigated whether PVAX-NPY3-36 could act as a therapeutic agent and induce angiogenesis and vascular remodeling in a murine model of hind limb ischemia. Adult C57BL/J6 mice (n = 40) were assigned to treatment groups: control, ischemia PBS, ischemia PVAX, ischemia NPY3-36, and Ischemia PVAX-NPY3-36 Ischemia was induced by ligation of the femoral artery in all groups except control and given relevant treatments (PBS, PVAX, NPY3-36, and PVAX-NPY3-36). Blood flow was quantified using laser Doppler imaging. On days 3 and 14 posttreatment, mice were euthanized to harvest gastrocnemius muscle for immunohistochemistry and immunoblotting. Blood flow was significantly improved in the PVAX-NPY3-36 group after 14 days. Western blot showed an increase in angiogenic factors VEGF-R2 and PDGF-ß (P = 0.0035 and P = 0.031, respectively) and antiapoptotic marker Bcl-2 in the PVAX-NPY3-36 group compared with ischemia PBS group (P = 0.023). Proapoptotic marker Smad5 was significantly decreased in the PVAX-NPY3-36 group as compared with the ischemia PBS group (P = 0.028). Furthermore, Y2 receptors were visualized in endothelial cells of newly formed arteries in the PVAX-NPY3-36 group. In conclusion, we were able to show that PVAX-NPY3-36 can induce angiogenesis and arteriogenesis as well as improve functional blood flow in a murine model of hind limb ischemia.NEW & NOTEWORTHY Our research project proposes a novel method for drug delivery. Our patented PVAX nanoparticle can detect areas of ischemia and oxidative stress. Although there have been studies about delivering angiogenic molecules to areas of ischemic injury, there are drawbacks of nonspecific delivery as well as short half-lives. Our study is unique because it can specifically deliver NPY3-36 to ischemic tissue and appears to extend the amount of time therapy is available, despite NPY3-36's short half-life.

Hydrogen Peroxide-Responsive Nanoparticle Reduces Myocardial Ischemia/Reperfusion Injury.

BACKGROUND: During myocardial ischemia/reperfusion (I/R), a large amount of reactive oxygen species (ROS) is produced. In particular, overproduction of hydrogen peroxide (H2O2) is considered to be a main cause of I/R-mediated tissue damage. We generated novel H2O2-responsive antioxidant polymer nanoparticles (PVAX and HPOX) that are able to target the site of ROS overproduction and attenuate the oxidative stress-associated diseases. In this study, nanoparticles were examined for their therapeutic effect on myocardial I/R injury. METHODS AND RESULTS: The therapeutic effect of nanoparticles during cardiac I/R was evaluated in mice. A single dose of PVAX (3 mg/kg) showed a significant improvement in both cardiac output and fraction shortening compared with poly(lactic-coglycolic acid) (PLGA) particle, a non-H2O2-activatable nanoparticle. PVAX also significantly reduced the myocardial infarction/area compared with PLGA (48.7±4.2 vs 14.5±2.1). In addition, PVAX effectively reduced caspase-3 activation and TUNEL-positive cells compared with PLGA. Furthermore, PVAX significantly decreased TNF-α and MCP-1 mRNA levels. To explore the antioxidant effect of PVAX by scavenging ROS, dihydroethidium staining was used as an indicator of ROS generation. PVAX effectively suppressed the generation of ROS caused by I/R, whereas a number of dihydroethidium-positive cells were observed in a group with PLGA I/R. In addition, PVAX significantly reduced the level of NADPH oxidase (NOX) 2 and 4 expression, which favors the reduction in ROS generation after I/R. CONCLUSIONS: Taken together, these results suggest that H2O2-responsive antioxidant PVAX has tremendous potential as a therapeutic agent for myocardial I/R injury.

Effectiveness of hyperbaric oxygen and ozone applications in tissue healing in generated soft tissue trauma model in rats: an experimental study.

BACKGROUND: Soft tissue trauma is a type of acute traumatic ischemia. We investigated in this study whether the edema, inflammation and ischemia caused by the trauma could be affected positively by hyperbaric oxygen (HBO) and ozone therapy. METHODS: Soft tissue trauma was generated in a total of 63 adult male Sprague-Dawley rats. Subsequently, rats were divided into three groups. The first group was treated with ozone, the second group with HBO, and the third group served as controls. Tissue and blood samples were taken at the end of the procedures. Tissue lipid peroxidation (LPO), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), inducible nitric oxide synthase (iNOS), heme oxygenase (HO)-1, and hypoxia-inducible factor (HIF)-1 levels were detected. Hematoxylin-eosin staining was used to determine the inflammation and edema histopathologically. RESULTS: We also detected HIF-1 activity, which decreases when the oxygen concentration increases, HO-1 activity, which has anti-inflammatory effects, and iNOS activity, which releases in any type of acute case. We determined a statistically significant reduction in iNOS and LPO levels in both the HBO and Ozone groups. A significant decrease in inflammation was detected in both the Ozone and HBO groups compared with the Control group, and a significant decrease in edema was detected in all three groups. CONCLUSION: We think that HBO and Ozone therapy have beneficial effects on biochemical and histopathological findings. Related clinical trials will be helpful in clarifying the effects.