Chitosan-Coated Collagen Membranes Promote Chondrocyte Adhesion,Growth, and Interleukin-6 Secretion

Designing scaffolds made from natural polymers may be highly attractive for tissue engineering strategies. We sought to produce and characterize chitosan-coated collagen membranes and to assess their efficacy in promoting chondrocyte adhesion, growth, and cytokine secretion. Porous collagen membranes were placed in chitosan solutions then crosslinked with glutaraldehyde vapor. Fourier transform infrared (FTIR) analyses showed elevated absorption at 1655 cm⁻¹ of the carbon–nitrogen (N=C) bonds formed by the reaction between the (NH₂) of the chitosan and the (C=O) of the glutaraldehyde. A significant peak in the amide II region revealed a significant deacetylation of the chitosan. Scanning electron microscopy (SEM) images of the chitosan-coated membranes exhibited surface variations, with pore size ranging from 20 to 50 μm. X-ray photoelectron spectroscopy (XPS) revealed a decreased C–C groups and an increased C–N/C–O groups due to the reaction between the carbon from the collagen and the NH₂ from the chitosan. Increased rigidity of these membranes was also observed when comparing the chitosan-coated and uncoated membranes at dried conditions. However, under wet conditions, the chitosan coated collagen membranes showed lower rigidity as compared to dried conditions. Of great interest, the glutaraldehyde-crosslinked chitosan-coated collagen membranes promoted chondrocyte adhesion, growth, and interleukin (IL)-6 secretion. Overall results confirm the feasibility of using designed chitosan-coated collagen membranes in future applications, such as cartilage repair.     

Plasma cells induce apoptosis of pre-B cells by interacting with bone marrow stromal cells

By using two-color phenotypic analysis with fluorescein isothiocyanate- anti-CD38 and phycoerythrin-anti-CD19 antibodies, we found that pre-B cells (CD38+CD19+) signifcantly decreased depending on the number of plasma cells (CD38++CD19+) in the bone marrow (BM) in the cases with BM plasmacytosis, such as myelomas and even polyclonal gammopathy. To clarify how plasma cells suppress survival of pre-B cells, we examined the effect of plasma cells on the survival of pre-B cells with or without BM-derived stromal cells in vitro. Pre-B cells alone rapidly entered apoptosis, but interleukin-7 (IL-7), a BM stromal cell line (KM- 102), or culture supernatants of KM-102 cells could support pre-B cell survival. On the other hand, inhibitory factors such as transforming growth factor-beta1 (TGF-beta1) and macrophage inflammatory protein- 1beta (MIP-1beta) could suppress survival of pre-B cells even in the presence of IL-7. Plasma cells alone could not suppress survival of pre- B cells in the presence of IL-7, but coculture of plasma cells with KM- 102 cells or primary BM stromal cells induced apoptosis of pre-B cells. Supernatants of coculture with KM-102 and myeloma cell lines (KMS-5) also could suppress survival of pre-B cells. Furthermore, we examined the expression of IL-7, TGF-beta1, and MIP-1beta mRNA in KM-102 cells and primary stromal cells cocultured with myeloma cell lines (KMS-5). In these cells, IL-7 mRNA was downregulated, but the expression of TGF- beta1 and MIP-1beta mRNA was augmented. Therefore, these results suggest that BM-derived stromal cells attached to plasma (myeloma) cells were modulated to secrete lesser levels of supporting factor (IL- 7) and higher levels of inhibitory factors (TGF-beta1 and MIP-1beta) for pre-B cell survival, which could explain why the increased number of plasma (myeloma) cells induced suppression of pre-B cells in the BM. This phenomenon may represent a feedback loop between pre-B cells and plasma cells via BM stromal cells in the BM.     

Induction of resistance to Schistosoma mansoni infection in mice by purified parasite paramyosin.

Freeze-thaw (FT)-disrupted schistosomula or their membrane extract induced significant resistance in mice to Schistosoma mansoni infection (34 and 25%, respectively) without the use of adjuvant. Antigens identified in schistosome extracts by sera from immunized animals were then evaluated for protective potential. Immunization with schistosomal antigens of 97 and 68-70 kD resulted in significant protection that was equivalent to that obtained by FT schistosomula. Since the 97-kD antigen was suggested to be parasite paramyosin, we used a biochemical technique to purify this muscle protein. Purified schistosome paramyosin ran as a single band on 10% SDS-PAGE and was recognized both by sera from mice immunized with FT schistosomula and a polyclonal antiserum raised against the 97-kD parasite protein. Preincubation of schistosome paramyosin with sera from mice immunized with FT schistosomula resulted in the removal of reactivity with the 97-kD protein in crude worm extracts. Paramyosin was identified by Western blotting to be in the tegument of schistosomula. The purified schistosome paramyosin resulted in significant protection in three separate experiments (24, 46, and 53%) without the use of adjuvant. Addition of BCG to paramyosin resulted in enhanced protection.     

Myelodysplastic syndromes with 5q deletion: pathophysiology and role of lenalidomide

Myelodysplastic syndrome (MDS) is a hematopoietic stem cell disorder primarily affecting CD34+ cells, characterized by ineffective hematopoiesis, often transforming into acute myelogenous leukemia (AML). A subset of patients has 5q deletion (del(5q)) as the culprit pathogenetic trigger. Del(5q) affects critical regions 5q31 and 5q33, leading to gene haplodeficiency with subsequent RPS14 haplodeficiency and P53 activation. Subsequent to P53 activation, erythroid cell apoptosis and ineffective erythropoiesis occur. Other pathogenetic elements include protein phosphatase 2a and CDC25C haplodeficiency and decreased miR-145 and miR-146a expression. Lenalidomide is an immunomodulatory agent that selectively suppresses the del(5q) clone. While the mechanism is not fully understood, it is associated with diverse molecular changes including stabilization of MDM2 with subsequent enhanced P53 degradation. Lenalidomide showed success in low- and intermediate-1-risk MDS as reported in the 002, 003, and 004 trials. However, in higher-risk MDS, the results of lenalidomide monotherapy were modest, mandating the use of combination therapy. The role and priority of lenalidomide varies between different guidelines, and accordingly, future efforts are necessary to reach a unified therapeutic algorithm. TP53 mutations are important predictors of AML progression and possible resistance to lenalidomide. It is recommended to identify TP53 mutation early in the disease since it may change the decision regarding choice of therapy. Challenges with lenalidomide therapy remain the long-term effects and timing of its discontinuation.     

Can transient elastography,Fib-4, Forns Index,and Lok Score predict esophageal varices in HCV-related cirrhotic patients?

Background

Gastroesophageal varices are present in approximately 50% of patients with liver cirrhosis. The aim of this study was to evaluate liver stiffness measurement (LSM), Fib-4, Forns Index and Lok Score as noninvasive predictors of esophageal varices (EV).

Methods

This prospective study included 65 patients with HCV-related liver cirrhosis. All patients underwent routine laboratory tests, transient elastograhy (TE) and esophagogastroduodenoscopy. FIB-4, Forns Index and Lok Score were calculated. The diagnostic performances of these methods were assessed using sensitivity, specificity, positive predictive value, negative predictive value, accuracy and receiver operating characteristic curves.

Results

All predictors (LSM, FIB-4, Forns Index and Lok Score) demonstrated statistically significant correlation with the presence and the grade of EV. TE could diagnose EV at a cutoff value of 18.2 kPa. Fib-4, Forns Index, and Lok Score could diagnose EV at cutoff values of 2.8, 6.61 and 0.63, respectively. For prediction of large varices (grade 2, 3), LSM showed the highest accuracy (80%) with a cutoff of 22.4 kPa and AUROC of 0.801. Its sensitivity was 84%, specificity 72%, PPV 84% and NPV 72%. The diagnostic accuracies of FIB-4, Forns Index and Lok Score were 70%, 70% and76%, respectively, at cutoffs of 3.3, 6.9 and 0.7, respectively. For diagnosis of large esophageal varices, adding TE to each of the other diagnostic indices (serum fibrosis scores) increased their sensitivities with little decrease in their specificities. Moreover, this combination decreased the LR− in all tests.

Conclusion

Noninvasive predictors can restrict endoscopic screening. This is very important as non invasiveness is now a major goal in hepatology.     

Outcome of aplastic anemia in adolescence: a survey of the Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation

We analyzed the outcome of 537 adolescents (age 12–18 years) with idiopathic aplastic anemia included in the database of the Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation comparing: i) matched family donor hematopoietic stem cell transplantation performed as first-line treatment with ii) front-line immunosuppressive therapy not followed by subsequent transplant given for failure and with iii) hematopoietic stem cell transplantation performed after failed front-line immunosuppressive therapy. Overall survival was 86% in the matched family donor hematopoietic stem cell transplantation group, 90% in patients given front-line immunosuppressive alone (those who did not fail this treatment and who did not receive subsequent rescue with hematopoietic stem cell transplantation) and 78% in subjects who underwent hematopoietic stem cell transplantation post failed front-line immunosuppressive therapy (P=0.14). Event-free survival in the same groups was respectively 83%, 64% and 71% (P=0.04). Cumulative incidence of rejection was 8% in matched family donor hematopoietic stem cell transplantation and 9% in transplants post failed front-line immunosuppression (P=0.62). Cumulative incidence of acute graft-versus-host disease was 12% in matched family donor transplants and 18% in transplants post failed immunosuppression (P=0.18). Chronic graft-versus-host disease was higher in matched family donor hematopoietic stem cell transplantation (8%) than in transplants post failed immunosuppressive therapy (20%) (P=0.0009). Cumulative incidence of post-therapy malignancies was 0.7% in matched family donor transplantations, 7% in transplantations post failed immunosuppression and 21% after front-line immunosuppression (P=0.0017). In the whole cohort, under multivariate analysis, the diagnosis to treatment interval of two months or under positively affected overall survival whereas up-front immunosuppression alone (with no subsequent rescue transplants) negatively affected event-free survival. In transplanted patients an interval from diagnosis to treatment of 2 months or under, bone marrow as source of cells and first-line matched family donor transplants provided a significant advantage in overall and event-free survival. Aplastic anemia in adolescents has a very good outcome. If a matched family donor is available, hematopoietic stem cell transplantation using bone marrow cells is the first choice treatment. If such a donor is not available, immunosuppressive treatment may still be an acceptable second choice, also because, in case of failure, hematopoietic stem cell transplantation is a very good rescue option.     

The Association of Diurnal Blood Glucose Variability With Subclinical Cardiac Disease in Patients With Type 2 Diabetes Mellitus

BackgroundThe relationship between glycemic control and the risk of cardiac disease in patients with Type 2 Diabetes Mellitus (T2DM) is controversial. 1,5-Anhydroglucitol (1,5-AG) is a biomarker of Glucose Variability (GV) and has been associated with clinical cardiovascular disease. However, its association with Subclinical Cardiac Disease (SCD) is unknown.Aim of the workStudy the association between GV and SCD.Subjects and methodsA cross-sectional study was conducted on 46 asymptomatic patients with T2DM as T2DM individuals group. Another 46 non-diabetic age and sex matched subjects were included as the healthy group. 1,5-AG was measured for all subjects. M-mode echocardiography in parasternal long axis view was used to measure Left Ventricular (LV) end diastolic dimension, LV end systolic dimension, ejection fraction, interventricular septum, LV posterior wall thickness, LV fractional shortening, left atrial dimension and aortic root dimension. Global Longitudinal Strain (GLS) was assessed by speckled tracking echocardiography.ResultsThere were no significant differences between both groups as regarding age, sex, BMI, AST, ALT, and serum creatinine. 1,5-AG was lower in T2DM individuals group. As regarding the echo parameters no significant difference found between both groups regarding left ventricular, left atrial and aortic root dimensions. T2DM individuals group showed a statistically significant higher mitral valve area, apical 2 chambers, apical 4 chambers, apical longitudinal axis and GLS. No correlation found between HbA1c and any echo parameters while 1,5-AG showed a significantly negative correlation with apical 2 chambers, apical 4 chambers, apical longitudinal axis and GLS. ROC curve analysis detected 1,5-AG less than 7.51 ng/ml as the best cut off value with sensitivity of 85.7%, specificity 75% to diagnose patients with T2DM and SCD.Conclusion1,5-AG might be used as an additional surrogate marker to identify patients with T2DM and SCD.     

Culprit lesion plaque characterization and thrombus grading by high-definition intravascular ultrasound in patients with ST-segment elevation myocardial infarction

Background

Dedicated prospective studies investigating high-definition intravascular ultrasound (HD-IVUS)-guided primary percutaneous coronary intervention (PCI) are lacking. The aim of this study was to qualify and quantify culprit lesion plaque characteristics and thrombus using HD-IVUS in patients presenting with ST-segment elevation myocardial infarction (STEMI).

Methods

The SPECTRUM study is a prospective, single-center, observational cohort study investigating the impact of HD-IVUS-guided primary PCI in 200 STEMI patients (NCT05007535). The first 100 study patients with a de novo culprit lesion and a per-protocol mandated preintervention pullback directly after vessel wiring were subject to a predefined imaging analysis. Culprit lesion plaque characteristics and different thrombus types were assessed. An IVUS-derived thrombus score, including a 1-point adjudication for a long total thrombus length, long occlusive thrombus length, and large maximum thrombus angle, was developed to differentiate between low (0–1 points) and high (2–3 points) thrombus burden. Optimal cut-off values were obtained using receiver operating characteristic curves.

Results

The mean age was 63.5 (±12.1) years and 69 (69.0%) patients were male. The median culprit lesion length was 33.5 (22.8–38.9) mm. Plaque rupture and convex calcium were appreciated in 48 (48.0%) and 10 (10.0%) patients, respectively. Thrombus was observed in 91 (91.0%) patients (acute thrombus 3.3%; subacute thrombus 100.0%; organized thrombus 22.0%). High IVUS-derived thrombus burden was present in 37/91 (40.7%) patients and was associated with higher rates of impaired final thrombolysis in myocardial infarction flow (grade 0–2) (27.0% vs. 1.9%, p < 0.001).

Conclusions

HD-IVUS in patients presenting with STEMI allows detailed culprit lesion plaque characterization and thrombus grading that may guide tailored PCI.     

Incidence of HCC in chronic hepatitis C patients with advanced hepatic fibrosis who achieved SVR following DAAs: A prospective study

Liver cirrhosis is an important risk factor for hepatocellular carcinoma. The reported annual incidence of HCC is about 3%‐8% in CHC cirrhotic patients. Based on the Cochrane systematic review, there was no clear evidence, on the long‐term clinical effects of DAAs in patients achieving SVR, as regard liver cirrhosis‐related HCC incidence. The aim of the study was to determine the incidence of HCC in chronic hepatitis C patients genotype IV with liver cirrhosis and advanced liver fibrosis after achieving SVR following DAA treatment in a prospective large cohort of HCV patients with long follow‐up. This was a prospective observational cohort study including 2372 CHC patients with advanced liver fibrosis or cirrhosis receiving DAA therapy in outpatient clinics at the Egyptian Liver Research Institute and Hospital since January 2015. Liver fibrosis was assessed using transient elastography. Abdominal ultrasonography and AFP measurement were done at baseline and follow‐up visits every 6 months, in addition to triphasic abdominal MSCT when needed. Patients were followed up after achieving SVR12 for at least 12 months. HCC developed in 109 cases during the follow‐up period (mean 23.60 ± 8.25 months). Overall HCC incidence was 2.338/100 PY, 95% CI = 1.942‐2.814. In patients with cirrhosis, the incidence of HCC was 2.917/100 PY, 95% CI = 2.407‐3.535, while in patients with advanced liver fibrosis the incidence of HCC was 0.664/100 PY, 95% CI = 0.333‐1.326. In conclusion, the incidence of HCC was reduced in chronic hepatitis C genotype 4 patients with liver cirrhosis (F4) and advanced hepatic fibrosis (F3) who achieved SVR following DAA therapy.