Cerebrospinal fluid cathepsin B and S

Cathepsins are increased in the brain of elderly animals. We investigate the presence of cathepsin B and S in human cerebrospinal fluid (CSF) plasma and the associations with cystatin C, age and sex. We measured cathepsin B and S concentrations in CSFs from 118 persons, undergoing elective surgical procedures, with ELISA. Both cathepsin B and cathepsin S were positively correlated with age. No correlation was observed between cathepsin B or S and length, height or body mass index. Both cathepsin B and S were positively correlated to the cystatin C concentration in CSF. Calculated reference intervals were 4,893–17,636 pg/mL for cathepsin B and 2,681–11,459 pg/mL for cathepsin S. Elderly individuals had significantly higher levels of both cathepsin B (r _s = 0.38, p = 0.00002) and cathepsin S (r _s = 0.35, p = 0.0001) in CSF.     

Quantitative assessment and determinants of suture-holding capacity of human pancreas

Background

Hard pancreas is welcome by surgeons performing resective pancreatic surgery, because it is believed to offer better suture holding capacity (SHC), thus decreasing the risk for a postoperative leak. However, neither the actual SHC of pancreatic tissue in humans nor its determinants have been studied.

Methods

We directly measured SHC for polydioxanone 5–0 suture and tissue hardness at the pancreatic isthmus in 53 human pancreata using a dynamometer and a durometer. A histologic score based on fibrosis grade, fat content, pancreatic duct size, and signs of chronic pancreatitis was calculated for every sample. We tested the hypothesis that SHC of the pancreas was proportional to tissue hardness, and evaluated the role of different possible histomorphologic determinants of SHC.

Results

Suture-holding capacity correlated perfectly with tissue hardness (r = 0.98; P < 0.001; 95% confidence interval, 0.96–0.99). The histologic score showed a stronger correlation with both parameters than any single histologic parameter. The SHC of transductal sutures was significantly higher than that of pure transparenchymal sutures. The SHC and hardness were significantly lower in patients who developed a clinically relevant pancreatic fistula postoperatively.

Conclusions

A mixture of histomorphologic features of human pancreas determines its tissue hardness and SHC. Involvement of the main pancreatic duct in the suture line appears to increase the mechanical strength of the pancreatic anastomosis.     

NKG2C deletion is a risk factor of HIV infection

NK cell function is important in the immune response to HIV infection. NKG2C and NKG2A are activating and inhibitory NK cell receptors, respectively, and their only known ligand, HLA-E, demonstrates increased expression in HIV infection and presents at least one HIV-derived peptide. A variation in chromosome 12 exists in which the 16-kb section of DNA encompassing the nkg2c gene is completely absent. DNA samples of 433 HIV-1-infected patients and 280 controls were genotyped by PCR, and revealed an association of the absence variation with a higher risk of HIV infection, as well as faster progression and higher pretreatment viral loads (p<0.05, respectively). Surface NKG2C expression, analyzed by FACS, on the freshly isolated lymphocytes of 20 control and 19 HIV-infected donors revealed that NKG2C expression is genotype dependent in both populations: no NKG2C expression in the -/- groups, intermediate expression in the +/- groups, and highest expression in the +/+ groups. The comparison of NKG2C and NKG2A expression in HIV and control groups (+/- and +/+ included) indicates an increased NKG2C expression on HIV patient NK cells (p<0.05) and decreased inhibitory NKG2A expression on CD8 T cells (p<0.001), and both these effects are more striking in the +/+ genotype (p<0.005). Furthermore, a positive correlation was found between HIV viral load and the proportion of NKG2C(+) NK cells. The increased expression of NKG2C in HIV patients, in combination with the genetic association of the absence variation with an increased susceptibility to HIV infection, higher HIV viral set point, and a faster progression, indicate that NKG2C is important in the defense against HIV infection and progression.     

Metabolic syndrome and its association with fatty liver disease after orthotopic liver transplantation

The metabolic syndrome (MetS) might contribute to morbidity after orthotopic liver transplantation (OLT). For this reason, we searched for MetS‐associated risk factors and analyzed the link with nonalcoholic fatty liver disease (NAFLD) in OLT recipients. De novo MetS affected 32.9% of our cohort (n = 170) within 2 years after OLT. Multivariate analysis identified glycosylated hemoglobin (HbA1c) levels ≥5% [odds ratio (OR) = 3.5; 95% confidence interval (CI) = 1.56–8.13, P = 0.003], diabetes mellitus (OR = 4.31, CI = 1.69–10.99, P = 0.002), and arterial hypertension (OR = 4.59, CI = 1.46–14.49, P = 0.009) as independent risk factors for de novo MetS. MetS incidence correlated with steroid dosage after OLT (5.2 ± 2.4 mg/day vs. 7.1 ± 4.7 mg/day, P = 0.014), and was linked to NAFLD (P = 0.001) via obesity (OR = 4.67, CI = 1.55–14.1, P = 0.006) and dyslipidemia (OR = 4.23, CI = 1.35–13.3, P = 0.013) post‐OLT. In conclusion, we were able to identify low threshold HbA1c as a novel risk factor for MetS after OLT and described a link of MetS with NAFLD in transplant organs. This study also indicated that steroid treatment is associated with MetS rates after OLT.     

Insulin is essential for in vitro chondrogenesis of mesenchymal progenitor cells and influences chondrogenesis in a dose-dependent manner

Purpose

Insulin is a commonly used additive in chondrogenic media for differentiating mesenchymal stem cells (MSCs). The indispensability of other bioactive factors like TGF-β or dexamethasone in these medium formulations has been shown, but the role of insulin is unclear. The purpose of this study was to investigate whether insulin is essential for MSC chondrogenesis and if there is a dose-dependent effect of insulin on MSC chondrogenesis.

Methods

We cultivated human MSCs in pellet culture in serum-free chondrogenic medium with insulin concentrations between 0 and 50 μg/ml and assessed the grade of chondrogenic differentiation by histological evaluation and determination of glycosaminoglycan (GAG), total collagen and DNA content. We further tested whether insulin can be delivered in an amount sufficient for MSC chondrogenesis via a drug delivery system in insulin-free medium.

Results

Chondrogenesis was not induced by standard chondrogenic medium without insulin and the expression of cartilage differentiation markers was dose-dependent at insulin concentrations between 0 and 10 μg/ml. An insulin concentration of 50 μg/ml had no additional effect compared with 10 μg/ml. Insulin was delivered by a release system into the cell culture under insulin-free conditions in an amount sufficient to induce chondrogenesis.

Conclusions

Insulin is essential for MSC chondrogenesis in this system and chondrogenic differentiation is influenced by insulin in a dose-dependent manner. Insulin can be provided in a sufficient amount by a drug delivery system. Therefore, insulin is a suitable and inexpensive indicator substance for testing drug release systems in vitro.     

Lack of cardioprotection from metabolic support with glutamine or glutamate in a porcine coronary occlusion model

Objective Previous experimental studies indicate that glutamine or glutamate may provide cardioprotection by improving the oxidative metabolism in myocardial ischemia. We investigated the effect of glutamine or glutamate, given during reperfusion, on resulting infarct size and hemodynamic recovery.

Design A porcine coronary occlusion model was applied. Infusions were initiated 15 min before reperfusion and supplemented with intracoronary bolus doses at reperfusion. The primary outcome measure was infarct size in relation to area at risk determined by a standard tissue staining procedure. Secondary outcome measures were the hemodynamic variables.

Results The infarct sizes as a proportion of the area at risk (mean±SD) were: control group, 0.64±0.19 (n=9); glutamine group, 0.87±0.07 (p<0.05 vs control group) (n=8); glutamate group, 0.72±0.11 (n=9). Glutamine increased systemic vascular resistance, while glutamate preserved cardiac output during infusion.

Conclusion Substrate supplementation with the anaplerotic precursors glutamine and glutamate is ineffective as adjunctive therapy for severe myocardial ischemia. Beneficial effects documented in less complex experimental systems could not be transferred to a more pathophysiological relevant model.     

Percutaneous Transluminal Coronary Angioplasty versus Thrombolysis in Acute Myocardial Infarction: A Prospective,Matched, Controlled Study

The aim of this study was to evaluate the outcome of primary percutaneous transluminal coronary angiography (PTCA) in the treatment of acute myocardial infarction (AMI) The study included patients with electrocardiographic signs of transmural AMI, symptom duration of less than 12 h, and with no contraindications to thrombolytic therapy. Patients who had undergone primary PTCA were matched consecutively, for age, gender, infarct localization and duration of symptoms, to patients who had received thrombolytic therapy (82 patients to each group). Patients who were admitted to hospital during daytime had a primary PTCA, whereas those admitted outside daytime were given thrombolytic therapy. In the primary PTCA group, 9 patients had a combined endpoint compared with 22 patients in the thrombolysis group (p &lt; 0.02 ). In-hospital mortality was 3.7% in the PTCA group and 4.9% in the thrombolysis group (ns). At six months, a combined endpoint occurred in 23 patients in the primary PTCA group and in 50 patients in the thrombolysis group (p &lt; 0.00005). Six months' mortality was 4.9% in the PTCA group and 7.3% in the thrombolysis group (ns). Among patients in the PTCA group, left ventricular ejection fraction was significantly higher, stay in hospital was shorter and there were significantly fewer incidences of heart failure and severe arrhythmias than among patients in the thrombolysis group. The results of primary PTCA implemented in our departments are comparable with those reported in randomized trials from experienced centres. Our study indicates that patients treated with primary PTCA have fewer complications, a better left ventricular systolic function and a shorter hospital stay compared with patients treated with thrombolysis.