Search

We investigated the capacity of human islets to produce monocyte chemoattractant protein-1 (MCP-1). Primary cultures of pancreatic islets expressed and secreted MCP-1, as determined by Northern blot, immunohistochemistry, in situ [...]

Introduction: Arteriovenous grafts (AVGs) serve as an alternative to native arteriovenous fistulas (AVFs) in the context of hemodialysis patient life planning. AVGs are more susceptible to developing outflow stenosis (due to intimal hyperplasia), thrombosis, and infections. However, an often overlooked contributor to AVG failure is cannulation damage. The objective of this paper is to assess the impact of cannulations on AVGs. We aim to establish a classification of AVG damage by comparing clinical data and ultrasound images with microscopic morphological findings obtained from explanted grafts.Materials and methods: This study is conducted at a single center. We included all patients who underwent AVG creation between 2011 and 2019. Comprehensive data on clinical history, follow-up, and complications were collected and reviewed. Duplex ultrasound (DUS) characteristics were documented, and all grafts explanted during the analysis period underwent optical microscopy evaluation. Finally, clinical data, along with DUS and microscopic findings, were integrated to derive a damage classification.Results: During the study period, 247 patients underwent 334 early cannulation AVGs. The median follow-up duration was 714 days (IQR 392, 1195). One hundred eleven (33%) grafts were explanted. Clinical data and DUS findings were utilized to formulate a four-grade classification system indicating increasing damage.Conclusion: Cannulation damage alone does not solely account for AVG failure. It results from a biological host-mediated process that promotes the growth of intimal hyperplasia at the cannulation sites. This process is not clinically significant within the initial 2 years after AVG creation.

The aim of this study was to evaluate the application of shear wave elastography (SWE) in the routine management of thyroid nodules, as a possible additional tool to the standard sonographic triage. A total of 248 consecutive patients scheduled for ultrasound‐guided thyroid fine‐needle aspiration were included in the study. The presence of a pure colloid lesion was an exclusion criterion. Absolute and relative SWE stiffness measurements on color‐coded elastograms, expressed in kilopascals and meters per second, were correlated with radiologic and pathologic features. SWE values in thyroid nodules were significantly higher than normal thyroid tissue (P= .0001), proving the different elastic properties of the pathologic tissues. Regarding the radiologic characteristics of the nodules, SWE highest values were associated with the largest lesions (P= .0105) but independent from sonographic and Doppler findings. The SWE elasticity was not influenced by the characteristics of the biopsy smears. The final correlation between the SWE results and the pathologic diagnoses showed a trend in stiffness from tender tumors (follicular adenoma) to papillary thyroid carcinoma (P= .016). SWE allows the identification of nodules within normal parenchyma; however, the present study does not confirm the potential role in differentiating between benign and malignant thyroid nodules.

Antigen masking in routinely processed tissue is a poorly understood process caused by multiple factors. We sought to dissect the effect on antigenicity of each step of processing by using frozen sections as proxies of the whole tissue. An equivalent extent of antigen masking occurs across variable fixation times at room temperature. Most antigens benefit from longer fixation times (>24 hr) for optimal detection after antigen retrieval (AR; for example, Ki-67, bcl-2, ER). The transfer to a graded alcohol series results in an enhanced staining effect, reproduced by treating the sections with detergents, possibly because of a better access of the polymeric immunohistochemical detection system to tissue structures. A second round of masking occurs upon entering the clearing agent, mostly at the paraffin embedding step. This may depend on the non-freezable water removal. AR fully reverses the masking due both to the fixation time and the paraffin embedding. AR itself destroys some epitopes which do not survive routine processing. Processed frozen sections are a tool to investigate fixation and processing requirements for antigens in routine specimens.

Several studies have shown that there is a paucity of immune cells within the stroma of pancreatic adenocarcinoma, a very aggressive cancer with a median survival of about 18 months. A 65-year-old man presented with jaundice. Abdominal ultrasound revealed intra- and extrahepatic bile duct dilatation and a 45-mm diameter hypoechoic solid mass within the pancreatic head; a computed tomography scan excluded vascular infiltration and metastatic lesions. The patient received immunotherapy consisting of 6,000,000 IU human recombinant interleukin-2 administered subcutaneously twice a day for 3 consecutive days. Thirty-six hours after the last dose, he underwent a pylorus-preserving pancreatoduodenectomy. Because of the presence of high-grade dysplasia detected by intraoperative histological examination of a distal section, a spleen preserving total pancreatectomy was performed. The postoperative course was uneventful. The patient died 32 months after surgery because of local recurrence. Histopathology showed G3 pancreatic ductal adenocarcinoma infiltrating the anterior and posterior peripancreatic tissue, duodenal wall and intrapancreatic common bile duct, with sarcoma-like foci and a component of intraductal tumor involving the common bile duct. In the distal pancreas, widespread foci of pancreatic intraepithelial neoplasia (PanIN2-3) were found. The Ki-67 proliferation index was 16%. TNM staging was pT3 pN1 R1. Sections were immunostained for the T-lymphocyte marker CD3 and for the dendritic cell marker CD1a. Intratumoral infiltration was high for CD1a+ cells and mild for CD3+ cells. Preoperative immunotherapy with interleukin-2 may contribute to massive stromal infiltration of immune cells in pancreatic adenocarcinoma. This may prolong the survival even in the presence of negative prognostic factors (age >65 years, tumor diameter >20 mm, R1, tumor grade G3).

We report a case of the contemporaneous presence of two histologically different pancreatic neoplasms, one renal cancer and one embryogenic duodenal anomaly in a single patient. A 66-year-old man underwent ultrasound examination because of urinary disorders; a solid neoformation within the inferior pole of the left kidney was observed. Computed tomography confirmed the renal lesion, but also a heterogeneous mass within the pancreatic head appeared without bile ducts dilatation. Abdominal magnetic resonance revealed a multiloculated cystic component of the pancreatic mass. A second CT scan confirmed the renal and biliary findings, but it revealed a modest enlargement of the pancreatic asymptomatic mass. A resection of the left kidney inferior pole and a pylorus-preserving pancreaticoduodenectomy were performed. Histopathologic analysis of the surgical specimen revealed mild differentiated papillary renal carcinoma, intraductal papillary mucinous adenoma of the pancreatic head, foci of intraepithelial pancreatic neoplasm and pancreatic heterotopy of duodenal muscular and submucosal layers. The coexistence of several primaries and anomalies in one patient led us to suppose a genetic predisposition to different lesions, even in the absence of known familial genetic syndromes. The study of such cases may help to improve the investigation of molecular correlations and etiological factors of different solid tumors. Nowadays, surgery is the only effective cure.

Bone marrow–derived mesenchymal stem cells (BM-MSCs) are stromal cells with the ability to proliferate and differentiate into many tissues. Although they represent powerful tools for several therapeutic settings, mechanisms regulating their migration to peripheral tissues are still unknown. Here, we report chemokine receptor expression on human BM-MSCs and their role in mediating migration to tissues. A minority of BM-MSCs (2% to 25%) expressed a restricted set of chemokine receptors (CXC receptor 4 [CXCR4], CX3C receptor 1 [CX3CR1], CXCR6, CC chemokine receptor 1 [CCR1], CCR7) and, accordingly, showed appreciable chemotactic migration in response to the chemokines CXC ligand 12 (CXCL12), CX3CL1, CXCL16, CC chemokine ligand 3 (CCL3), and CCL19. Using human pancreatic islets as an in vitro model of peripheral tissue, we showed that islet supernatants released factors able to attract BM-MSCs in vitro, and this attraction was principally mediated by CX3CL1 and CXCL12. Moreover, cells with features of BM-MSCs were detected within the pancreatic islets of mice injected with green fluorescent protein (GFP)–positive BM. A population of bona fide MSCs that also expressed CXCR4, CXCR6, CCR1, and CCR7 could be isolated from normal adult human pancreas. This study defines the chemokine receptor repertoire of human BM-MSCs that determines their migratory activity. Modulation of homing capacity may be instrumental for harnessing the therapeutic potential of BM-MSCs.

Rapamycin is a recently introduced immunosuppressive agent. Its effect on lymphocytes has been extensively studied. Whether it can also modulate dendritic cell (DC) function is unknown.

The possibility of performing transplantation several days after explant seems to be a peculiarity of islet grafts, and the opportunity to cryopreserve human islets may permit an indefinite period for modulating the recipient immune system. The aim of the present study was the evaluation of in vitro and in vivo functional properties of cryopreserved human islets.

A case of rapidly fatal small cell sarcoma of kidney in a young woman is described. Histologic, immunohistochemical, and ultrastructural studies demonstrated some features not reported previously in the literature, such as the arrangement of vimentin intermediate filaments in small irregular masses and the presence of various types of cytoplasmic projections. These findings, together with the observation of rare neoplastic elements with immunophenotypic and subcellular aspects of histiocytic and myofibroblastic differentiation, suggest that this tumor should be included in a group of small cell sarcomas of kidney lacking features of differentiation and should be considered a new variant occurring in adulthood.

We have isolated a novel cDNA (SEL1L) that shows sequence similarities to SEL-1, a gene identified as an extragenic suppressor of thelin-12hypomorphic mutant fromCaenorhabditis elegans(7, 8). SEL1L exhibits a tissue-specific pattern of expression: a single poly(A)+RNA species of 7.5 kb is abundantly expressed only in the pancreas of healthy individuals, whereas low to undetectable levels are observed in other adult and in some fetal tissues. Somatic hybrid panel and fluorescencein situhybridization positioned this gene in the q31 band of human chromosome 14. The tissue-specific expression of this gene induced us to study its role in human pancreatic carcinomas. Our analysis revealed that 17% of adenocarcinomas of the pancreas did not express SEL1L to a detectable level; however, no gross genomic alterations were apparent in the few hundred kilobases of the relevant region.