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Interstitial Edema-Preventing Mechanisms
Published in Waldemar L. Olszewski, Lymph Stasis: Pathophysiology, Diagnosis and Treatment, 2019
In reference to (2), as demonstrated by Olszewski,32 chronic lymphedema in dogs following extensive excision of leg lymphatics is preceded by severe changes in remaining or regenerated collecting lymphatics. The vessels become fibrotic, dilated, and develop valvular insufficiency. While the transport capacity of these vessels may be greatly reduced, it is likely that they can still transport a decent amount of lymph, provided an increased “filling pressure”. The situation may be similar to that of failing heart ventricles, which may maintain a reasonable cardiac output as long as atrial pressure is increased. While it is still uncertain what determines the filling of the initial lymphatics, both interstitial pressure and volume may be important.35 As pointed out by Wiederhielm30 and Granger et al.,31 attainment of a new steady state following impairment of lymph transport would take weeks, compared to hours or a few days following increased capillary filtration.
Frequency-selective heart defibrillation model
Published in Waldemar Wójcik, Sergii Pavlov, Maksat Kalimoldayev, Information Technology in Medical Diagnostics II, 2019
T.A. Smerdova, E.L. Pirotti, M.V. Bachinsky, V.E. Krivonosov, S.M. Goncharuk, M. Maciejewski, S. Kalimoldayeva
Defibrillation is the cessation of fibrillatory contractions of the heart ventricles or atria. The onset of ventricular fibrillation leads to increased hypoxia and a drop in the tone of the heart, which causes cardiac arrest. The probability of patients survival with ventricular fibrillation decreases by 7–10% every minute (Valenzuela et al. 1997, Haskel 1978, Hossack & Hartwig 1982, Krawczyk et al. 2003). The method of defibrillation is to act on the heart with a strong electric discharge, which removes the ventricular fibrillation and leads to the restoration of normal heart function (Smerdova 2014). The main goal of defibrillation is to successfully interrupt ventricular fibrillation with the smallest discharge to avoid damage to the myocardium, which is often observed when high energy is used (Dahl et al. 1988) (Kerber et al. 1988).
Biochemistry
Published in Burkhard Madea, Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
Müller and co-workers made a significant contribution to investigating Tg and thyroid hormone concentrations in heart blood samples obtained from mechanical asphyxia cases (including hanging, strangulation by ligature and throttling) and control cases [49–52]. These authors observed higher Tg levels in heart blood serum samples in individuals who died by hanging (Tg levels ranging from 12 ng/ml to more than 400 ng/ml) compared to sudden death cases. Moreover, the highest Tg concentrations were measured in cases of incomplete suspension (i.e. hanging in a sitting or semi-reclining posture), possibly suggesting an influence of agony duration on heart blood Tg levels [49]. In a subsequent study, Müller et al. [50] found higher T4 concentrations in heart blood serum in cases of hanging as well as higher T3 values in heart blood serum in cases of unexpected natural death and hanging. In another report, Müller et al. [52] measured Tg concentrations in blood samples obtained from both heart ventricles in hanging, throttling and strangulation by ligature cases. Comparisons pertaining to the obtained heart blood Tg values were performed among the asphyxia subgroups themselves as well as between asphyxia subgroups and control cases (sudden deaths). The highest mean Tg concentration was observed in throttling cases (561.6 ng/ml). Although the highest Tg values were measured in throttling and hanging cases (853 ng/ml and 892 ng/ml respectively), value ranges in cases of hanging (4–892 ng/ml) and strangulation by ligature (2–628 ng/ml) were larger than in throttling cases (252–853 ng/ml). Furthermore, statistically significant differences were found between throttling and strangulation by ligature as well as between throttling and hanging. Müller et al. [52] emphasized that, although potentially contributory to the elucidation of antemortem mechanical asphyxia, postmortem Tg values should not be used individually to confirm a vital reaction diagnosis in cases of suspected external neck compression but always in association with morphological findings obtained from autopsy.
Pro-BNP Levels and Its Prognostic Role in Chronic Hypertensive Pregnancies: A Prospective Case-Control Study From A Tertiary Care Hospital
Published in Hypertension in Pregnancy, 2021
Mehmet Akif Erdol, Atakan Tanacan, Hasan Eroglu, Nazan Vanli Tonyali, Mehmet Erdogan, Aykan Yucel, Nuray Yazihan, Dilek Sahin
Various natriuretics have been studied in hypertensive disorders of pregnancy, one of them is B-type natriuretic peptide (BNP). BNP is synthesized, stored, and secreted from heart ventricles depending on pressure or fluid overload. Pro-BNP is separated by proteolysis to short active BNP and inactive N-terminal pro-BNP (NT-proBNP). In previous studies, NT-proBNP levels were found to be higher in patients with preeclampsia and gestational HT compared to the control group [3–5] Although there are conflicting studies, it has been shown that NT-proBNP can be a prognostic marker for poor outcomes in pregnancy with preeclampsia [3,5]. BNP levels in patients with chronic HT may be higher than in healthy adults even in the pre-hypertensive stage [6]. Knowledge about BNP levels in chronic hypertensive pregnancies is limited. In the present study, we aimed to investigate plasma NT-proBNP levels and their prognostic role in pregnant women with chronic hypertension.
Trends in post–heart transplant biopsies for graft rejection versus nonrejection
Published in Baylor University Medical Center Proceedings, 2021
Aayla K. Jamil, Aasim Afzal, Tariq Nisar, Aaron Y. Kluger, Joost Felius, Detlef Wencker, Shelley A. Hall, Parag Kale
Endomyocardial biopsies (EMBs) are performed routinely for the diagnosis of cardiomyopathies and have been the standard of care for surveillance of post–heart transplant cardiac allograft rejection. This invasive procedure uses flexible bioptomes through femoral access in the groin or internal jugular access through the neck to get small 2 to 5 mm tissue samples from the heart ventricles. The procedure is guided by two-dimensional echocardiography or fluoroscopy, both of which have limitations. Fluoroscopic imaging systems can make the directional control of the bioptome tip tricky, while echocardiography can miss the tip of a deflectable bioptome, and the chordae tendineae, fibrous heart valve cords, can be damaged due to missed detection. Scarring from frequent biopsies can also result in difficult biopsy with insufficient tissue for testing.1 Newer noninvasive blood tests are commercially available to test graft rejection by serial gene expression to gauge cellular function, using microarrays to test gene transcription from mRNA, which also provides information about the immune status of the allograft.2 Such testing is easier on the patients and requires fewer hospital resources than invasive EMBs done in a catheterization unit. In this study, we looked at national trends for EMB procedures in posttransplant patients to determine the burden of EMBs done in noncomplicated heart graft recipients.
FOXF1 ameliorates angiotensin II-induced cardiac fibrosis in cardiac fibroblasts through inhibiting the TGF-β1/Smad3 signaling pathway
Published in Journal of Receptors and Signal Transduction, 2020
A total of 6 female Sprague-Dawley rats (age, 6 weeks; weight, 180–200 g) were obtained from the Animal Breeding Center of Luohe Medical College (Luohe, China) as reported previously [8], with minor modifcations. They were housed in barrier facilities under a 12-h light/dark cycle at a temperature of 22 ± 2˚C and had free access to laboratory chow and tap water. Rats were used to harvest CFs. Briefly, rats were anesthetized intraperitoneally with sodium pentobarbital (50 mg/kg). Heart ventricles were removed under sterile conditions, placed in cold sterile calcium-free PBS, minced into ∼2-mm cubes, and treated with 1 mg/ml type II collagenase (Santa Cruz Biotechnology, Santa Cruz, CA, MA, USA). Dissociated cells were cultured in Dulbecco’s modifed Eagle’s medium (DMEM; Invitrogen; Thermo Fisher Scientifc, Inc., Waltham, MA, USA) supplemented with 10% fetal bovine serum (FBS; Sigma-Aldrich; Merck KGaA), 100 U/ml penicillin sulfate and 100 U/ml streptomycin (Sigma-Aldrich; Merck KGaA) at pH 7.4, in an incubator with a humidified atmosphere of 5% CO2 at 37˚C. All experimental procedures were approved by the guidelines of the Animal Care and Use Committee of Luohe Medical College (Luohe, China).