14 research outputs found
Presence of C-type natriuretic peptide in human kidney and urine
Presence of C-type natriuretic peptide in human kidney and urine. The current study was undertaken to investigate the presence of CNP immunoreactivity in both human kidney and urine. Immunohistochemical staining with an indirect immunoperoxidase method utilizing an antibody which is 100% cross-reactive to both CNP-53 and CNP-22 was performed on five human kidney specimens (three biopsies of normal cadaveric donor kidneys and two of normal autopsy specimens). CNP immunoreactivity was positive in proximal, distal and medullary collecting duct tubular cells in a cytoplasmic and granular staining pattern. CNP immunoreactivity was also determined in the urine of five healthy volunteers utilizing a sensitive and specific double-antibody radioimmunoassay with a mean concentration of 10.8 ± 1.0 pg/ml. With the utilization of high pressure liquid chromatography, this immunoreactivity proved to be consistent with both the low molecular weight form, CNP-22, as well as the high molecular weight form, CNP-53. Urinary excretion of CNP was also measured in normal subjects (N = 5) and in patients with congestive heart failure (CHF, N = 6). CHF patients excreted over three times more CNP than normals (27.2 ± 2.8 vs. 8.7 ± 0.81 pg/min, P < 0.004) despite no difference between the two groups in plasma CNP concentrations (6.97 ± 0.28 vs. 8.08 ± 1.52 pg/ml, P = NS). This study demonstrates for the first time the presence of CNP immunoreactivity in human kidney and suggests that renal tubular cells may be an additional non-vascular site of synthesis for this cardiorenal acting peptide. This study also demonstrates an increase in urinary CNP excretion in congestive heart failure
Elimination, reversal, and directional bias of optical diffraction
We experimentally demonstrate the manipulation of optical diffraction,
utilizing the atomic thermal motion in a hot vapor medium of
electromagnetically-induced transparency (EIT). By properly tuning the EIT
parameters, the refraction induced by the atomic motion may completely
counterbalance the paraxial free-space diffraction and by that eliminates the
effect of diffraction for arbitrary images. By further manipulation, the
diffraction can be doubled, biased asymmetrically to induced deflection, or
even reversed. The latter allows an experimental implementation of an analogy
to a negative-index lens
COVID-19-Related Thrombotic and Bleeding Events in Adults With Congenital Heart Disease.
BACKGROUND
Altered coagulation is a striking feature of COVID-19. Adult patients with congenital heart disease (ACHD) are prone to thromboembolic (TE) and bleeding complications.
OBJECTIVES
The purpose of this study was to investigate the prevalence and risk factors for COVID-19 TE/bleeding complications in ACHD patients.
METHODS
COVID-19-positive ACHD patients were included between May 2020 and November 2021. TE events included ischemic cerebrovascular accident, systemic and pulmonary embolism, deep venous thrombosis, myocardial infarction, and intracardiac thrombosis. Major bleeding included cases with hemoglobin drop >2Â g/dl, involvement of critical sites, or fatal bleeding. Severe infection was defined as need for intensive care unit, endotracheal intubation, renal replacement therapy, extracorporeal membrane oxygenation, or death. Patients with TE/bleeding were compared to those without events. Factors associated with TE/bleeding were determined using logistic regression.
RESULTS
Of 1,988 patients (age 32 [IQR: 25-42] years, 47% male, 59 ACHD centers), 30 (1.5%) had significant TE/bleeding: 12Â TE events, 12 major bleeds, and 6 with both TE and bleeding. Patients with TE/bleeding had higher in-hospital mortality compared to the remainder cohort (33% vs 1.7%; PÂ <Â 0.0001) and were in more advanced physiological stage (PÂ =Â 0.032) and NYHA functional class (PÂ =Â 0.01), had lower baseline oxygen saturation (PÂ =Â 0.0001), and more frequently had a history of atrial arrhythmia (PÂ <Â 0.0001), previous hospitalization for heart failure (PÂ <Â 0.0007), and were more likely hospitalized for COVID-19 (PÂ <Â 0.0001). By multivariable logistic regression, prior anticoagulation (OR: 4.92; 95%Â CI: 2-11.76; PÂ =Â 0.0003), cardiac injury (OR: 5.34; 95%Â CI: 1.98-14.76; PÂ =Â 0.0009), and severe COVID-19 (OR: 17.39; 95%Â CI: 6.67-45.32; PÂ <Â 0.0001) were independently associated with increased risk of TE/bleeding complications.
CONCLUSIONS
ACHD patients with TE/bleeding during COVID-19 infection have a higher in-hospital mortality from the illness. Risk of coagulation disorders is related to severe COVID-19, cardiac injury during infection, and use of anticoagulants