Thyrotropic activity of crude hCG in FRTL-5 rat thyroid cells

The presence of thyroid stimulating activity in partially purified hCG was investigated using, as bioassay system, iodide uptake in rat thyroid FRTL-5 cells. The biological responses evoked by hCG were tested after neutralisation with monoclonal and polyclonal antisera to hTSH and hCG, and after fractionation on Sephadex G-100. The molar amounts of TSH and hCG in respective preparations were calculated assuming an activity of 30 IU/mg and 19 IU/mg, respectively, for bTSH and hTSH, and of 14,000 IU/mg for hCG. A dose-dependent response, paralleling that evoked by bTSH, was observed in a concentration range of 0.1-4 mumol/l hCG; 1 mumol of hCG was equivalent to 50 pmol of bTSH and 132 pmol of hTSH. The thyrotropic activity coeluted with hCG immunoactivity on Sephadex G-100. Incubation with monoclonal anti-hTSH antibodies did not affect the stimulatory ability of hCG preparation, indicating that it was not due to hTSH contamination. Similarly, a pretreatment with monoclonal and polyclonal anti-hCG antibodies did not significantly alter the iodide uptake response induced by hCG. These results indicate that the thyrotropic activity in partially purified hCG is not due to the presence of aspecific contaminants, but to a substance structurally related to hCG in terms of molecular weight. However, it appeared to differ from hCG immunologically, suggesting the hypothesis that minor modifications in the molecular structure may confer thyrotropic activity on hCG, altering its immunoreactive potency.     

Ischemia Modified Albumin for the assessment of patients presenting to the emergency department with acute chest pain but normal or non-diagnostic 12-lead electrocardiograms and negative cardiac troponin T

BACKGROUND: The diagnosis of myocardial ischemia in patients with acute chest pain at rest but non-diagnostic electrocardiograms (ECG) is problematic. Ischemia Modified Albumin (IMA) is a new biochemical marker of ischemia, which may be useful to characterise acute coronary syndrome (ACS) patients. METHODS: We studied 131 patients (mean age 58.5 years; 95 male) presenting to the emergency department with symptoms suggestive of ACS but with normal or non-diagnostic ECGs. Cardiac troponin T (cTnT) and IMA were measured within 3 h of last chest pain episode. Based on hospital diagnostic test results, patients were classified as having ACS or non-ischemic chest pain (NICP), by two independent cardiologists unaware of IMA results. RESULTS: Mean IMA levels (U/ml) were higher in patients with ACS (98.3+/-11) compared to patients with NICP (85.5+/-15); p<0.0001. IMA levels >93.5 U/ml demonstrated a sensitivity and specificity of 75% for the diagnosis of ACS; area under the receiver operator characteristic curve 0.78 (95% CI: 0.70-0.85). If we applied the manufacturer cutoff point of 85 U/ml, the sensitivity of IMA increased to 90.6% with a specificity of 49.3% (negative predictive value=84.6%). In combination with cTnT (6-12 h) (>0.05 ng/ml), the sensitivity increased to 92.2%. After multivariate analysis, IMA levels >85 U/ml (odds ratio=14.6 [95% CI 4.4-48.4]; p<0.0001), age and prior myocardial infarction were independent predictors of ACS. CONCLUSION: IMA may be a useful biomarker for the identification of ACS in patients presenting with typical acute chest pain but normal or non-diagnostic ECGs.     

Application of transcatheter valves for aortic valve replacement in pediatric patients: A case series

• Diabetic patients are frequently affected by coronary artery disease (CAD) and are at increased risk of CAD‐related adverse events, even after drug‐eluting stent (DES) implantation. If currently available DES have similar safety and efficacy in diabetic and nondiabetic patients is still debated.
• This prospective, multicenter registry showed similar 3‐year outcome in patients undergoing different DES implantation, although diabetic patients, especially those requiring insulin treatment, had significantly higher risk of adverse events than nondiabetic patients.
• Specific efforts to improve the performance of DES in diabetic patients are mandatory to adequately address the unsolved issue of diabetic patients affected by CAD.

     

Renal transplantation in HLA sensitized patients: Traversing the immunological barrier

Successful renal transplantation across HLA barrier in sensitized individuals has been on the rise during the past decade, primarily due to improved desensitization regimes. The aim of this study was to share outcome of desensitization in renal transplant recipients with donor‐specific anti‐HLA antibodies (DSA). This was a retrospective analysis of all HLA immunized individuals who were prospective renal transplant recipients. All such patients underwent preconditioning as per the institutional desensitization protocol. Complement‐dependent cytoxicity‐based crossmatch (CDC‐XM), luminex‐based crossmatch (LM‐XM) and flowcytometry‐based crossmatch (FC‐XM) were done in all cases. If any of these tests turned out positive, single antigen bead assay (SAB) was performed. Desensitization for DSA was performed in 55 patients and all patients were followed‐up for 1 year to assess graft function and patient outcome. CDC‐XM being a less sensitive assay, could not detect incompatibility in 29 (52.73%) cases. After desensitization, even though SAB and LM‐XM results revealed an MFI within acceptable range, FC‐XM being an extremely sensitive assay, continued to give a positive result in eight (14.55%) cases. The mean ± SD number of pretransplant TPE were 3.44 ± 0.98 (2‐11). Out of 55, there were 10 patients who were lost to follow up. Patient and graft survival of 45 patients at 1 year was found to be 100%. Preconditioning for renal transplants in the form of immunosuppression with TPE is an extremely useful auxiliary for transplantation in HLA sensitized renal transplant recipients.     

A copper chelate selectively triggers apoptosis in myeloid-derived suppressor cells in a drug-resistant tumor model and enhances antitumor immune response

Myeloid-derived suppressor cells (MDSCs), one of the major orchestrators of immunosuppressive network are present in the tumor microenvironment suppress antitumor immunity by subverting Th1 response in tumor site and considered as a great obstacle for advancement of different cancer immunotherapeutic protocols. Till date, various pharmacological approaches have been explored to modulate the suppressive functions of MDSCs in vivo. The present study describes our endeavor to explore a possibility of eradicating MDSCs by the application of a copper chelate, namely copper N-(2-hydroxy acetophenone) glycinate (CuNG), previously found to be a potential immunomodulator that can elicit antitumorogenic Th1 response in doxorubicin-resistant EAC (EAC/Dox) bearing mice. Herein, we demonstrated that CuNG treatment could reduce Gr-1+CD11b+ MDSC accumulation in ascitic fluid and spleen of EAC/Dox tumor model. Furthermore, we found that CuNG mediated reduction in MDSCs is associated with induction of Th1 response and reduction in Treg cells. Moreover, we observed that CuNG could deplete MDSCs by inducing Fas-FasL mediated apoptotic cell death where death receptor Fas expression is enhanced in MDSCs and FasL is provided by activated T cells. However, MDSC expansion from bone marrow cells and their differentiation was not affected by CuNG. Altogether, these findings suggest that the immunomodulatory property of CuNG is attributed to, at least in part, by its selective cytotoxic action on MDSCs. So, this preclinical study unveils a new mechanism of regulating MDSC levels in drug-resistant cancer model and holds promise of translating the findings into clinical settings.     

Thrombospondin-1 Deficiency Causes a Shift from Fibroproliferative to Inflammatory Kidney Disease and Delays Onset of Renal Failure

Thrombospondin-1 (TSP1) is a multifunctional matricellular protein known to promote progression of chronic kidney disease. To gain insight into the underlying mechanisms through which TSP1 accelerates chronic kidney disease, we compared disease progression in Col4a3 knockout (KO) mice, which develop spontaneous kidney failure, with that of Col4a3;Tsp1 double-knockout (DKO) mice. Decline of excretory renal function was significantly delayed in the absence of TSP1. Although Col4a3;Tsp1 DKO mice did progress toward end-stage renal failure, their kidneys exhibited distinct histopathological lesions, compared with creatinine level–matched Col4a3 KO mice. Although kidneys of both Col4a3 KO and Col4a3;Tsp1 DKO mice exhibited a widened tubulointerstitium, predominant lesions in Col4a3 KO kidneys were collagen deposition and fibroblast accumulation, whereas in Col4a3;Tsp1 DKO kidney inflammation was predominant, with less collagen deposition. Altered disease progression correlated with impaired activation of transforming growth factor-β1 (TGF-β1) in vivo and in vitro in the absence of TSP1. In summary, our findings suggest that TSP1 contributes to progression of chronic kidney disease by catalyzing activation of latent TGF-β1, resulting in promotion of a fibroproliferative response over an inflammatory response. Furthermore, the findings suggest that fibroproliferative and inflammatory lesions are independent entities, both of which contribute to decline of renal function.Progression of chronic kidney disease (CKD) toward end-stage renal failure (ESRF) is a prominent problem in clinical nephrology.¹ The incidence of CKD is rising, but effective therapies to halt progression of disease remain elusive.² Progression of CKD results from a complex interplay of pathologies that involve all constituents of the kidney, which makes it difficult to single out targets for effective therapeutic strategies.³The extent of so-called tubulointerstitial fibrosis is often considered to be the rate-limiting step in progression of CKD.¹ This idea is founded on histopathological analysis of large cohorts of kidney biopsies, which demonstrated that only tubulointerstitial fibrosis (which at the time was determined as the relative volume of the interstitium within a kidney biopsy section) correlates with and also predicts progression of CKD toward ESRF, irrespective of the underlying primary disease.^{4, 5, 6, 7} Widening of the tubulointerstitium, which is referred to as tubulointerstitial fibrosis, is caused by a composite of extracellular matrix (ECM) accumulation, sterile inflammation, accumulation of activated fibroblasts, and rarefaction of microvessels.¹ Although the relevance of each of these events to progression of fibrosis and CKD is hotly debated, this knowledge led to the concept that tubulointerstitial fibrosis is a common pathway of all chronic progressive kidney diseases and that effective antifibrotic therapies could potentially halt progression of CKD irrespective of the underlying disease. However, such therapies are not yet available.¹Our aim was to gain insight into mechanisms that underlie the contribution of thrombospondin-1 (TSP1) to progression of CKD. TSP1 is the most-studied member of the thrombospondin family of matricellular proteins.⁸ Previous studies have demonstrated that pharmacological suppression or genetic depletion of TSP1 attenuates disease progression in animal models of CKD.^{9, 10, 11, 12, 13} TSP1 is a 450-kDa trimeric ECM protein, which does not fulfill primarily structural roles in the matrix, but instead functions as an extracellular modulator of cell function.^{8, 14} Most prominently, TSP1 is known to inhibit angiogenesis, inhibit inflammation, activate MMP-dependent ECM turnover, and facilitate fibroblast migration and activation, all of which are considered important contributors to progression of CKD.^{8, 10} To delineate through which of its known biological activities TSP1 impacts progression of CKD, we compared progression of kidney disease of Col4a3 knockout (KO) mice (deficient in type IV collagen α3 chain) with that of Col4a3;Tsp1 double-knockout (DKO) mutant mice.¹⁵Here, we demonstrate that decrease of excretory renal function is delayed if TSP1 is absent. Furthermore, tissue analysis of plasma creatinine level–matched kidneys of Col4a3 KO and of Col4a3;Tsp1 DKO revealed that in Col4a3 KO mice disease progression is predominantly associated with fibrosis, whereas inflammation is the predominant interstitial pathology in Col4a3;Tsp1 DKO mice. We provide evidence that this altered disease progression is due to impaired activation of latent transforming growth factor-β1 (TGF-β1) in the absence of TSP1. Our findings provide evidence that both fibroproliferative injury and inflammation can independently cause expansion of the interstitium, leading to decline of excretory renal function.