Analysis of Antral Biopsy Specimens for Evidence of Acquired Mucosa-Associated Lymphoid Tissue in HIV1-Seropositive and HIV1-Negative Patients

Background: There is conflicting evidence concerning the prevalence of Helicobacter pylori gastritis in HIV1-infected patients. Furthermore, a possible influence of immunodeficiency on the acquisition of mucosa-associated lymphoid tissue (MALT) in the antral mucosa remains to be elucidated.

Methods: Seventy-seven consecutive HIV1-infected patients (mean age, 40.2 years) were compared in a prospective study with 77 HIV1-negative age-matched patients, using immunohistochemical stainings.

Results: In HIV1-infected patients the prevalence of H. pylori gastritis was lower and the inflammatory reaction less pronounced than in controls. Lymphoid follicles and intraepithelial B cells were significantly more often detected in HIV1-negative patients.

Conclusions: Evidence of acquired MALT is only rarely found in HIV1-infected patients. These findings might contribute to the explanation of why low-grade gastric MALT lymphomas have not been reported in HIV1-infected patients so far.     

Recent advances in systemic therapy of soft tissue sarcomas

Improvements in surgical techniques, for example reconstructive surgery; and radiation therapy techniques, such as intensity-modulated radiotherapy; have made some impact on the functional outcomes of sarcomas with a local biology. Effective local control can be achieved with effective function in the vast majority of patients. The problem of distant metastases, however, continues to plague a large group of patients with this disease. Recent advances in the systemic therapy of sarcomas is highlighted by the rapid development and approval of the molecularly targeted therapy imatinib (Gleevec^®) for advanced gastrointestinal stromal tumors. Several other agents have been, or are being studied with far less rewarding results. Among these, the more encouraging examples include the nucleoside analog gemcitabine (Gemzar^®) and gemticibine/docetaxel (Taxotere^®) in combination, which display some selective activity in sarcomas of gynecologic origin. The marine compound ecteinascidin (ET-743) has been studied in two different schedules (24 and 3 h infusions), demonstrating biological activity worthy of further investigation. Identification of new agents with activity in this diverse group of diseases is extremely important. Identification of specific targets responsible for tumorigenesis and effective inhibition of these targets holds the most promise for future improvement in cure rates. However, until such time, it is equally important to emphasize clinical research attempting to further optimize the use of the standard chemotherapeutic agents, with growth-factor support in appropriately selected patients.     

Guidelines and considerations for conducting experiments using tissue microarrays

Tissue microarrays (TMAs) represent a powerful method for undertaking large‐scale tissue‐based biomarker studies. While TMAs offer several advantages, there are a number of issues specific to their use which need to be considered when employing this method. Given the investment in TMA‐based research, guidance on design and execution of experiments will be of benefit and should help researchers new to TMA‐based studies to avoid known pitfalls. Furthermore, a consensus on quality standards for TMA‐based experiments should improve the robustness and reproducibility of studies, thereby increasing the likelihood of identifying clinically useful biomarkers. In order to address these issues, the National Cancer Research Institute Biomarker and Imaging Clinical Studies Group organized a 1‐day TMA workshop held in Nottingham in May 2012. The document herein summarizes the conclusions from the workshop. It includes guidance and considerations on all aspects of TMA‐based research, including the pre‐analytical stages of experimental design, the analytical stages of data acquisition, and the postanalytical stages of data analysis. A checklist is presented which can be used both for planning a TMA experiment and interpreting the results of such an experiment. For studies of cancer biomarkers, this checklist could be used as a supplement to the REMARK guidelines.     

Ectopic osteogenesis of hBMP-2 gene-transduced human bone mesenchymal stem cells/BCB

We determined the feasibility of using scaffolds of adenoviral human BMP2 gene (AdBMP2)-modified human bone marrow mesenchymal stem cells (hBMSCs) and antigen-free bovine cancellous bone (BCB) to construct bone tissue. hMSCs were infected with AdBMP-2. Expression of BMP-2 and alkaline phosphatase confirmed successful secretion of active BMP-2. The osteogenic capability of a composite of AdBMP2-modified hMSCs with BCB was evaluated in athymic mice (group A). BCB (group B), hMSCs/BCB (group C), adenoviral β‐galactosidase genes (Adβgal)-transfected hMSCs/BCB (group D) were controls. Formation of bone tissue was assessed by histological methods 4 weeks and 8 weeks after implantation. Implanted cells were identified by human Y-chromosome-specific fluorescence in-situ hybridization (FISH). hMSCs differentiated into osteogenic cells, and bone formation was observed. Obvious bone formation was not noted at any time point in control groups. We hypothesize that the described method is a promising method for bone regeneration.     

Connective Tissue News

The editor welcomes for publication short news items of interest to readers of this journal, and especially details of forthcoming symposia and conferences concerned with subjects pertinent to the field.     

Book Reviews

Abstract

The authors report a method for mounting methyl methacrylate-embedded samples of bone in a manner that provides superior stability and more reproducible orientation. In addition, this system provides for a filing procedure similar to paraffin block filing systems. (The J Histotechnol 31(4): 179–182, 2008)

Submitted March 17, 2008; accepted with revisions June 22, 2008     

Differential staining of mast cells with toluidine blue

Abstract

Mast cells play a significant role in inflammatory diseases such as asthma, inflammatory bowel disease, and autoimmune diseases. Inhibition of c-kit receptor tyrosine kinase, a growth factor receptor, significantly reduces mast cell numbers. The purpose of this study was to determine the effect of Compound X (a c-kit inhibitor) on mast cell numbers in rats. Connective tissue mast cells (CTMCs) and mucosal mast cells (MMCs) have differing histochemical characteristics which presents a challenge when staining for quantification by semi-automated image analysis. CTMCs are present in tissues such as tongue and skin and will stain readily in tissues fixed routinely. In contrast, MMCs, such as those present in the intestinal mucosa, are sensitive to fixation. Brief fixation in Carnoy’s solution, although seldom used due to its composition (a mixture of ethanol, chloroform, and acetic acid), was employed to fix tissues for MMC staining, while tissues for CTMC demonstration were fixed in 10% neutral buffered formalin. An enzyme histochemistry method, napthol AS-D choloroacetate (specific esterase), was briefly considered for staining; however, granulocytes stained along with mast cells, requiring manual identification and exclusion, thereby rendering the method incompatible with automated means of quantification. Instead, staining was performed using two different toluidine blue methods which have proven conducive to semi-automated image analysis techniques. CTMCs were stained using Luna’s toluidine blue, while MMCs were stained with Matsson’s toluidine blue modification. In summary, the selected methods, based upon a conventional stain, were easy to do and successfully identified both populations of mast cells for quantification by image analysis.     

Processing of Paraffin Embedded Tissues for Flow Cytometry

Abstract

Aneuploidy (abnormal numbers of chromosome sets) and a rapidly dividing cell population have been well known characteristics of malignant disease. Cell ploidy is now also recognized as a reliable indicator of tumor aggressiveness and response to treatment, and flow cytometry is a relatively new procedure for quantitating nuclear DNA content as an index of ploidy. The technique has been utilized to analyze cells in body fluids or cells extracted from fresh solid tissues. We have used recently developed methods to analyze cells taken from formalin fixed, paraffin embedded tissues. (The J Histotechnol 10: 109,1987)