Objective. There is an increased interest in rheumatology in mesenchymal progenitor/stem cells (MPCs) and their roles in rheumatic diseases, but little is known about the phenotype of these cells in vivo. The aim of this study was to isolate and characterize human bone marrow (BM) MPCs.Methods. Fluorescence microscopy was used to identify putative MPCs among adherent BM cells. To purify them, a positive selection with antifibroblast microbeads was used, combined with fluorescenceactivated cell sorting (FACS) for microbead؉,CD45 low cells. A more detailed phenotype of these cells was determined using 4-color flow cytometry, and standard chondrogenic, osteogenic, and adipogenic assays were used to investigate their differentiation potentials.Results. Putative MPCs microscopically identified as large, fibroblast-like, D7-FIB؉ cells were purified using positive selection with D7-FIB-conjugated (antifibroblast) microbeads followed by FACS for specifically bound microbead؉,CD45 low cells. These cells represented 0.01% of mononuclear cells in the BM. They were uniformly positive for CD105, LNGFR, HLA-DR, CD10, CD13, CD90, STRO-1, and bone morphogenetic protein receptor type IA (BMPRIA) and were negative for CD14, CD34, CD117, and CD133. Only cells with this phenotype could proliferate and produce adherent cell monolayers capable of chondrogenic, osteogenic, and adipogenic differentiation. D7-FIB؊ cells in the BM lacked any MPC activity. Uncultured skin fibroblasts had a phenotype similar to that of BM MPCs, but were negative for LNGFR, STRO-1, HLA-DR, and BMPRIA.Conclusion. This study shows the distinct phenotype, morphology, and method of isolation of BM MPCs. The findings may have implications for defining the physiologic roles of MPCs in arthritis, bone diseases, and joint regeneration.

Numerous procedures for data analysis of seed germination responses are scattered throughout the literature. Here an attempt has been made to summarize the existing methods, to compare the information they provide and to examine their strengths and weaknesses. The methods reviewed include the percent germination, germination index, coefficient of velocity, median response time, probit analysis, curve‐fitting of cumulative germination, heat sums, survival analysis with life tables, logistic regression, proportional hazards regression and accelerated failure time analysis. Comparisons among these method are discussed and illustrated with data from germination responses in tomato (Lycopersicon eseulentum Mill.). Seed germination involves not only qualitative responses of individuals, but also population responses which are distributed over time. Standard analysis of variance or regression methods are appropriate for a data analysis where germination of all viable seed is observed, but they are inappropriate when some viable seeds fail to germinate. Such missing (censored) data complicates statistical analysis and subsequent interpretation. Germinations tests should be designed to determine the nature of censored responses, which can be subsequently accommodated by several statistical procedures referred to as survival analysis.

Purpose:To investigate the possibility of using combined blood oxygen level-dependent (BOLD) imaging and diffusion-weighted imaging (DWI) to detect pathological and physiological changes in renal tissue damage of the kidney induced by chronic renal hyperfiltration. Materials and Methods:The apparent diffusion coefficient (ADC) and the T 2 * value within the inner compartments of the kidneys of 17 rats with diabetes mellitus were compared with the results obtained from a control group (N ϭ 16). The influence of dynamic changes of the renal function on the blood-oxygen saturation was evaluated by comparing the T 2 * values before and after the active reduction of tubular transport by furosemide injection.Results: All compartments of the diabetic kidney showed significantly (P Ͻ 0.05) lower T 2 *-values compared to the control group. In particular, the very low values in the outer stripe (OS) of the outer medulla (OM) (T 2 *-normal: 69.4 Ϯ 10.9 msec; T 2 *-diabetic: 51.4 Ϯ 13.9 msec) indicated either hypoxia due to hyperfiltration, or renal blood volume changes. Diffusion imaging of the same area showed significantly lower ADC values (ADC-normal: 1.45 Ϯ 0.26; ADCedema: 1.19 Ϯ 0.25 [10 -9 m 2 /s]) that correlated with pathological findings on histopathology. The injection of furosemide significantly (P Ͻ 0.05) increased T 2 * in all compartments of both populations while the ADC remained unchanged.Conclusion: BOLD-contrast imaging appears to be able to depict tissue at risk from ischemia by revealing information about the balance between tubular workload and delivery of oxygen, and thus may reflect a measure of the reserve capacity. The diffusion measurements apparently reveal complementary information. Although ADC imaging is not sensitive to the current energy metabolism, it appears toreflect the pathological changes within the tissue. Therefore, ADC measurements may be a sensitive indicator of the severity of ischemic lesions.

This study characterizes the diffusion anisotropy of the human kidney using a diffusion-weighted, single-shot echo planar imaging (EPI) sequence in order to access the full apparent diffusion tensor (ADT) within one breathhold. The fractional anisotropy (FA) of the cortex and the medulla were found to be 0.22 ؎ 0.12 and 0.39 ؎ 0.11, respectively (N ‫؍‬ 10), which emphasizes the need for rotationally invariant diffusion measurements for clinical applications. Additional limitations for clinical diffusion imaging on the kidney are the strong susceptibility variations within the abdomen that restrict the use of imaging techniques employing long echo trains, and the severe motion sensitivity that limits the available imaging time to one breath-hold. To overcome these problems an isotropic, diffusion-weighted, segmented EPI protocol that facilitates the acquisition of high-resolution diffusion-weighted images within a single breath-hold was implemented. Using this method, the apparent diffusion coefficient (ADC) of the cortex and medulla were found to be 2. 89 Index terms: diffusion; magnetic resonance imaging; kidney; EPI; fractional anisotropy WATER TRANSPORT is the predominant phenomenon throughout the kidney due to the kidney's major role in water reabsorption and concentration-dilution functions. These movements are mainly located in the tubular cells and are controlled either by active or passive mechanisms, depending on their location in the nephrons. Consequently, the measurement of the diffusion characteristics of the kidney may provide useful insights into the mechanisms of various renal diseases, including chronic renal failure, renal artery stenosis, and uretral obstruction. However, renal diffusion imaging is very challenging due to the extreme motion sensitivity of diffusion-weighted sequences, and the clinical use of this technique has been hampered by both the severe motion artifacts caused by arterial pulsations and respiratory motion. Diffusion-weighted single-shot-EPI (DW-SSEPI) (1), in conjunction with single breath-hold imaging (2-6) and peripheral pulse unit (PPU) triggering, (7) has been suggested as a possible means of overcoming these problems. However, the restriction of the diffusion experiment to a single breathhold limits the possible spatial resolution and the precision of the diffusion measurement (the number of directions for the diffusion weighting, the number of b-values, and the number of averages). As a result, most studies in the literature have measured the ADC in only one direction (2,4 -7), and hence have implicitly assumed that the diffusion characteristics of the kidney are isotropic. Hydration has been shown to increase global ADC values (3), while renal artery stenosis or ureteral obstruction decreased the values (2,3). In cases of acute or chronic renal failure, the cortical and medullary ADC values were significantly lower than in normal kidneys, and the cortical values were highly correlated with the serum creatinine levels (2).Although some studies have implied that t...

A rapid dynamic imaging sequence has been developed in which only the 32 phase encoding steps that encode low spatial frequencies are collected for each dynamic image. These are substituted into a previously acquired, 128 x 128 raw data set prior to image reconstruction. In this way the dynamic information is retained while the overall appearance is improved in comparison with images obtained by zero filling to 128 x 128, leading to better qualitative evaluation. The limited k-space sampling means that the technique is most effective for large homogeneous areas of signal change since fine changes in contrast are imperfectly recorded.

The Haematological Malignancy Research Network (HMRN) was established in 2004 to provide robust generalizable data to inform clinical practice and research. It comprises an ongoing population-based cohort of patients newly diagnosed by a single integrated haematopathology laboratory in two adjacent UK Cancer Networks (population 3·6 million). With an emphasis on primary-source data, prognostic factors, sequential treatment/response history, and socio-demographic details are recorded to clinical trial standards. Data on 8131 patients diagnosed over the 4 years 2004–08 are examined here using the latest World Health Organization classification. HMRN captures all diagnoses (adult and paediatric) and the diagnostic age ranged from 4 weeks to 99 years (median 70·4 years). In line with published estimates, first-line clinical trial entry varied widely by disease subtype and age, falling from 59·5% in those aged <15 years to 1·9% in those aged over 75 years – underscoring the need for contextual population-based treatment and response data of the type collected by HMRN. The critical importance of incorporating molecular and prognostic markers into comparative survival analyses is illustrated with reference to diffuse-large B-cell lymphoma, acute myeloid leukaemia and myeloma. With respect to aetiology, several descriptive factors are highlighted and discussed, including the unexplained male predominance evident for most subtypes across all ages.

Summary. The aim of this study was to develop a flow cytometric test to quantitate low levels of circulating myeloma plasma cells, and to determine the relationship of these cells with disease stage. Cells were characterized using five-parameter flow cytometric analysis with a panel of antibodies, and results were evaluated by comparison with fluorescent consensus-primer IgH-PCR.Bone marrow myeloma plasma cells, defined by high CD38 and Syndecan-1 expression, did not express CD10, 23, 30, 34 or 45RO, and demonstrated weak expression of CD37 and CD45. 65% of patients had CD19 ¹ 56 þ plasma cells, 30% CD19 ¹ 56 low , and 5% CD19 þ 56 þ , and these two antigens discriminated myeloma from normal plasma cells, which were all CD19 þ 56 low .Peripheral blood myeloma plasma cells had the same composite phenotype, but expressed significantly lower levels of CD56 and Syndecan-1, and were detected in 75% (38/51) of patients at presentation, 92% (11/12) of patients in relapse, and 40% (4/10) of stem cell harvests. Circulating plasma cells were not detectable in patients in CR (n ¼ 9) or normals (n ¼ 10), at a sensitivity of up to 1 in 10 000 cells. There was good correlation between the flow cytometric test and IgH-PCR results: myeloma plasma cells were detectable by flow cytometry in all PCR positive samples, and samples with no detectable myeloma plasma cells were PCR negative. Absolute numbers decreased in patients responding to treatment, remained elevated in patients with refractory disease, and increased in patients undergoing relapse. We conclude that flow cytometry can provide an effective aternative to IgH-PCR that will allow quantitative assessment of low levels of residual disease.

University of Newcastle, Newcastle upon Tyne NE2 4HH.Interferon-y (IFN-y) is an important cytoldne involved in regulation of the activation, growth and differentiation of immune cells and other cell types such as those of the endothelium. Previously we have demonstrated that IFN-y activity is antagonised by heparin, a heavily dphated glyco&noglycan (GAG), and the structurally related molecule heparan dphate. More recently, using a oon-anticoagulant heparin derivative (Leo Pharmaceuticals), we have shown that the ability of heparin to inhibit IFN-y is unrelated to its anticoagulant activity. In this present study, we have investigated the underlying mechanism for IFN-y inhibition by heparin.Radioligand binding assays demonstrated that total binding of 'z'I-labelled IFN-y to the EAhy.926 endothelial hybridoma cell line was significantly reduced in the presence of heparin or heparan sulphate at 125pglml; the structurally dissimilar GAG chondroitin sulphate had no effect.This suggests that soluble heparin inhibits IFN--, by competing with heparinlike, cell-surface GAGs to bind the cytoldw.Treatment of EAhy.926 cells with 25mM chlorate was non-toxic but inhibited the incorporation of ["S]-sulphate into GAG chains, and greatly reduced the capacity of these cells to bind [lUI]-IFN-y; this was paralleled by decreased upregulation of class I1 MHC antigens by IFN-y stimulated cells that had been pre-treated with chlorate. This indicates that sulphated, negatively charged regions on cell-surface GAGs are involved in both the sequestration and biological activity of IFN-y.A cationic 10 amino acid peptide sequence (-AKTGKRKRSG-) from the C-terminal region of IFN-y was found to competitively reduce binding of ['"I]-IFN-y to the cell line. This provides evidence for interaction between a specific region of the cytokine molecule and cell-surface GAGs.These results indicate that IFN-y is sequestered onto endothelial cells by binding to sulphated, heparin-like domains on cell-surface heparan sulphate proteoglycans. This interaction appears to be essential for optimal cytokine activity and represents a potential target for clinical immune modulation.Two candidate tumour supressor genes have been mapped to 9 2 1 . a region conundy lost in tumours. These candidate genes are p16 and p15. W e have studied a series of squamous cell carcinomas of the head and neck (SCC-HN) with respect to p15 and p16. W e have found that LOH on 9p21 is a common event in SCC. W e have also found that all of our immortal cell lines have undetectable expression of p16. This appears to be due to either homoygous deletion of the gene or transcriptional silencing of the gene by methylation. W e have observed no mutations in the coding sequence of any of the lines retaining p16. Reintroduction of p16 into immortal cell lines causes a reduction in cloning efficiency. In contrast the p15 gene was rarely transcriptionally silenced and was not homoygously deleted in any of the cell lines showing deletion of p16. The status of pRb appears normal in all our cell lies...