The synthesis and localization of alternatively spliced fibronectin EIIIB in resting and thrombin-treated megakaryocytes

There are several species of alternatively spliced fibronectin (FN). One of these, FN EIIIB, is primarily present in embryonic and in proliferating and migrating cells and is believed to be important for cell maturation. We have studied the synthesis, localization, and secretion of this FN isoform in isolated guinea pig megakaryocytes, nonmegakaryocytic bone marrow cells, and platelets. There was 7.5 times more general FN in megakaryocytes than in nonmegakaryocytic cells based on the analysis of equivalent amounts of protein. FN EIIIB was detected by Western blotting in megakaryocytes but not in nonmegakaryocytic cells present in bone marrow. Neither megakaryocytes nor platelets secreted FN EIIIB, while megakaryocytes secreted 25.3% +/- 4.6% general FN and platelets secreted about 61% general FN in response to thrombin. Analysis of immunostained cells by confocal microscopy revealed that FN EIIIB had been redistributed to the surface of megakaryocytes in response to thrombin. Synthesis was studied by metabolic labeling, and megakaryocytes were shown to synthesize FN and FN EIIIB. Thus, megakaryocytes and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. The expression of FN EIIIB on the megakaryocyte surface may influence migration and maturation.     

Identification of Inflamed Atherosclerotic Lesions In Vivo Using PET-CT

Inflammation plays a major pathogenetic role in the development of atherosclerotic plaques and related thromboembolic events. The identification of vulnerable plaques is of the utmost importance, as this may allow the implementation of more effective preventive and therapeutic interventions. Fluorodeoxyglucose positron emission tomography (FDG-PET) has been shown to be useful for tracing inflammation within plaques. However, its relationship to immunohistochemical findings in different territories of the peripheral circulation was not completely elucidated. We aimed to determine whether plaque inflammation could be measured by PET in combination with computer tomography (CT) using FDG and what is the relationship between FDG uptake and immunohistochemical findings in the removed atherosclerotic lesions of the femoral and carotid arteries. The study included 31 patients, 21 patients with high-grade stenosis of the internal carotid artery (ICA) and 10 patients with occlusion of the common femoral artery (CFA), all of whom underwent endarterectomy. Before endarterectomy in all patients, FDG-PET/CT imaging was performed. FDG uptake was measured as the maximum blood—normalized standardized uptake value, known as the target to background ratio (TBR max). TBR max amounted to 1.72?±?0.8, and in patients with ICA, stenosis was not significantly different from patients with CFA occlusion. Immunohistochemical and morphometric analyses of the plaques obtained at endarterectomy showed that the density of T lymphocytes and macrophages (number of cells per square millimeter) was significantly higher in subjects with stenosis of the ICA than in subjects with occlusion of the femoral arteries: lymphocytes, 1.26?±?0.21 vs. 0.77?±?0.29; p?=?0.02 and macrophages, 1.01?±?0.18 vs. 0.69?±?0.23; p?=?0.003. In the whole group of patients, the density of inflammatory cells significantly correlated with FDG uptake represented by PET-TBR max: T lymphocytes, r?=?0.60; p?<?0.01 and macrophages, r?=?0.65; p?<?0.01. The results of our study show that FDG uptake is related to the accumulation of inflammatory cells in atherosclerotic lesions. This finding suggests that FDG uptake reflects the severity of atherosclerotic vessel wall inflammation, and in stenotic lesions, it could be an indicator of their vulnerability. However, data from large outcome studies is needed to estimate the usefulness of this technique in identifying the most dangerous atherosclerotic lesions and vulnerable patients.     

Young red blood cells; observations about the cytometric and morphologic alterations in the beginning of their life

Summary A recently described separation technique consisting of a combination of counterflow centrifugation and subsequent density (Percoll) scparation was tested for its ability to enrich red cell populations with young cells in comparison to either separation technique alone. The relative age of every fraction was determined by HbAlc measurements, resulting in the lowest HbAlc for the combination method. Conventional reticulocyte counting and floweytometric counting with thiazole orange indicated that in the youngest fractions the combination method showed the highest reticulocyte counts. There was a good correlation between manual and flowcytometric counting results. Radio-iron studies showed a two-fold enrichment with young cells in the fraction with the lowest HbAIc acquired by the combination technique in comparison to the other two methods. Cytometric measurements showed that the fractions with the lowest HbAlc were the ones with the highest MCV and MCH and the lowest MCHC. Besides loss of their RNA-material, young cells already seem to loose water and haemoglobin like older cells, resulting in a decrease of MCV and MCH and in increase in MCHC. It is concluded that combining counterflow centrifugation with subsequent density fractionation results in superior enrichment with young cells in comparison to the results of each method alone.     

Infection of central nervous system after kidney transplantation

Central nervous system (CNS) infection remains an important problem among transplant recipients. The recent review by Singh and Husain and this letter from Yugoslavia underline the following: a subacute‐chronic presentation is typical of fungal and bacterial CNS infections; early diagnosis is the key to effective therapy; the indication for a CNS evaluation is an unexplained headache, particularly in conjunction with a change in the level of consciousness (classical meningeal findings may not be present in a timely fashion); and the minimum CNS evaluation is a cranial computerized tomographic (CT) scan and a lumbar puncture. Robert H. Rubin, MD     

Effects of lowering dialysate calcium concentration on mineral metabolism and parathyroid hormone secretion: a multicentric study

This prospective study was conducted with the aim of examining the efficacy of lowering dialysate calcium (dCa) in order to: (i) stimulate bone turnover in hemodialysis patients with biochemical signs of adynamic bone disease (ABD) (hypercalcemia, normal alkaline phosphatase and intact parathyroid hormone (iPTH) <150 pg/mL); and (ii) diminish hypercalcemia in patients with secondary hyperparathyroidism (sHPT) (hypercalcemia, high alkaline phosphatase and iPTH > 400 pg/mL), thus permitting the use of calcium-containing phosphorus binders and vitamin D metabolites. Patients were divided into: an ABD-treated group (24 patients), a sHPT-treated group (18 patients), an ABD-control group (12 patients) and a sHPT-control group (11 patients). For the ABD- and sHPT-treated patients, hemodialysis was conducted with dCa 1.5 mmol/L for three months and then with dCa 1.25 mmol/L for an additional three months, while in the control groups hemodialysis was conducted with dCa 1.75 mmol/L during the entire study. Reduction of dCa in patients with ABD caused a slight but insignificant decrease of Ca, but a significant and permanent increase of bone-specific alkaline phosphatase and intact parathyroid hormone level serum levels. Reduction of dCa in patients with sHPT slightly but insignificantly decreased Ca and intact parathyroid hormone level values. Nevertheless, this enabled the calcium-based phosphate binder dose to be raised and vitamin D3 metabolites to be introduced. Logistic regression analysis indicated that milder bone disease (both ABD and sHPT) was associated with more the favorable effect of dCa reduction. Thus, low dCa stimulated parathyroid glands and increased bone turnover in ABD patients, and enabled better control of mineral metabolism in sHPT patients.     

Contrast-induced nephropathy in a patient with type 2 diabetes and coronary artery disease: a case report

Contrast-induced nephropathy (CIN) is the impairment of kidney function defined as a serum creatinine increase of 25% or 44 µmol/L compared with baseline, usually occurring 24 to 48 hours after the use of intravenous contrast. Important risk factors for CIN include female sex, advanced age (>65 years), type 2 diabetes (T2D), kidney disease, advanced heart failure, and intravascular volume depletion. We herein present a male patient with T2D, moderately reduced renal function, no albuminuria, and a positive echocardiography stress test. He underwent percutaneous coronary intervention (PCI), and two drug-eluting stents (in the left anterior descending coronary artery) and three bare-metal stents (in the right coronary artery) were implanted. Despite adequate rehydration (0.9% intravenous NaCl with 8.4% sodium bicarbonate) before and after the procedures, he developed irreversible kidney injury after coronary angiography and PCI. This case report demonstrates the unpredictable clinical course of CIN. Patients with T2D are at high risk for the occurrence of CIN, so careful clinical assessment is recommended with global renal functional reserve evaluation.     

冠状动脉搭桥术早期并发症及死亡率(附196例报告)

1985年1月～1987年12月作者于荷兰格罗宁根医学科学院心胸外科主做了196例冠状动脉搭桥术。术后早期死亡2例(1.0％)、内出血3例(1.5％)、胸骨裂开2例(1.0％)、心律紊乱40例(20.4％)、围手术期心肌梗塞5例(2.6％),本文就术后早期并发症进行了讨论。     

Regulation of bone remodeling by vitamin K2

All living tissues require essential nutrients such as amino acids, fatty acids, carbohydrates, minerals, vitamins, and water. The skeleton requires nutrients for development, maintaining bone mass and density. If the skeletal nutritional requirements are not met, the consequences can be quite severe. In recent years, there has been growing interest in promotion of bone health and inhibition of vascular calcification by vitamin K2. This vitamin regulates bone remodeling, an important process necessary to maintain adult bone. Bone remodeling involves removal of old or damaged bone by osteoclasts and its replacement by new bone formed by osteoblasts. The remodeling process is tightly regulated, when the balance between bone resorption and bone formation shifts to a net bone loss results in the development of osteoporosis in both men and women. In this review, we focus on our current understanding of the effects of vitamin K2 on bone cells and its role in prevention and treatment of osteoporosis.