Dynamic compaction of human mesenchymal stem/precursor cells into spheres self-activates caspase-dependent IL1 signaling to enhance secretion of modulators of inflammation and immunity (PGE2, TSG6, and STC1)

Human mesenchymal stem/precursor cells (MSC) are similar to some other stem/progenitor cells in that they compact into spheres when cultured in hanging drops or on nonadherent surfaces. Assembly of MSC into spheres alters many of their properties, including enhanced secretion of factors that mediate inflammatory and immune responses. Here we demonstrated that MSC spontaneously aggregated into sphere-like structures after injection into a subcutaneous air pouch or the peritoneum of mice. The structures were similar to MSC spheres formed in cultures demonstrated by the increased expression of genes for inflammation-modulating factors TSG6, STC1, and COX2, a key enzyme in production of PGE2. To identify the signaling pathways involved, hanging drop cultures were used to follow the time-dependent changes in the cells as they compacted into spheres. Among the genes upregulated were genes for the stress-activated signaling pathway for IL1α/β, and the contact-dependent signaling pathway for Notch. An inhibitor of caspases reduced the upregulation of IL1A/B expression, and inhibitors of IL1 signaling decreased production of PGE2, TSG6, and STC1. Also, inhibition of IL1A/B expression and secretion of PGE2 negated the anti-inflammatory effects of MSC spheres on stimulated macrophages. Experiments with γ-secretase inhibitors suggested that Notch signaling was also required for production of PGE2 but not TSG6 or STC1. The results indicated that assembly of MSC into spheres triggers caspase-dependent IL1 signaling and the secretion of modulators of inflammation and immunity. Similar aggregation in vivo may account for some of the effects observed with administration of the cells in animal models.

Analysis of morphine and codeine in samples adulterated with Stealth

Stealth is an adulterant used to avoid detection of drug abuse. The product does have an effect on the ability to detect several drugs of abuse, including the opiates morphine and codeine. It has previously been shown that low concentration (2500 ng/mL morphine) samples adulterated with Stealth tested negative by both Roche OnLine and Microgenics CEDIA immunoassays, but those spiked with higher concentrations (6000 ng/mL of codeine and morphine glucuronide) were positive. Initial results showed confirmation analysis was also sometimes negatively impacted by this adulterant. Urine samples were spiked with 6000 ng/mL of codeine and/or morphine glucuronide to assess the effect of Stealth. Each individual sample was split into separate aliquots. One aliquot of each was adulterated with Stealth following package directions. The samples were then tested by immunoassay and gas chromatography-mass spectrometry (GC-MS). The control and adulterated aliquots were positive by both immunoassays. Results of GC-MS analysis of the Stealth-adulterated aliquots following standard procedures using deuterated internal standards proved unsuccessful in several cases. In 4 of 12 cases (33%), neither the drugs nor internal standards were recovered despite repeated attempts. In one other sample, recovery was dramatically reduced, making accurate quantitation impossible, whereas the unadulterated aliquots of the same samples posed no problem with recovery. Addition of sodium disulfite to the aliquots prior to extraction allowed recovery of the drugs and internal standards from all samples. Analysis of the samples showed the concentration of morphine and codeine decreased in some by as much as 17 and 30%, respectively. In other cases, there was essentially no difference in the concentration seen before and after adulteration, with or without disulfite treatment. Unless the initial concentration of opiate is near the cutoff, samples containing opiates are likely to be immunoassay positive, it is important to consider this procedure as an option for samples that screen positive but the opiates and their respective internal standards are not recovered for GC-MS analysis.

The surface ectoderm is essential for nephric duct formation in intermediate mesoderm

The nephric duct is the first epithelial tubule to differentiate from intermediate mesoderm that is essential for all further urogenital development. In this study we identify the domain of intermediate mesoderm that gives rise to the nephric duct and demonstrate that the surface ectoderm is required for its differentiation. Removal of the surface ectoderm resulted in decreased levels of Sim-1 and Pax-2 mRNA expression in mesenchymal nephric duct progenitors, and caused inhibition of nephric duct formation and subsequent kidney development. The surface ectoderm expresses BMP-4 and we show that it is required for the maintenance of high-level BMP-4 expression in lateral plate mesoderm. Addition of a BMP-4-coated bead to embryos lacking the surface ectoderm restored normal levels of Sim-1 and Pax-2 mRNA expression in nephric duct progenitors, nephric duct formation and the initiation of nephrogenesis. Thus, BMP-4 signaling can substitute for the surface ectoderm in supporting nephric duct morphogenesis. Collectively, these data suggest that inductive interactions between the surface ectoderm, lateral mesoderm and intermediate mesoderm are essential for nephric duct formation and the initiation of urogenital development.

Limb deformity proteins: role in mesodermal induction of the apical ectodermal ridge

During early limb development, distal tip ectoderm is induced by the underlying mesenchyme to form the apical ectodermal ridge. Subsequent limb growth and patterning depend on reciprocal signaling between the mesenchyme and ridge. Mice that are homozygous for mutations at the limb deformity (ld) locus do not form a proper ridge and the anteroposterior axis of the limb is shortened. Skeletal analyses reveal shortened limbs that involve loss and fusion of distal bones and digits, defects in both anteroposterior and proximodistal patterning. Using molecular markers and mouse-chick chimeras we examined the ridge-mesenchymal interactions to determine the origin of the ld patterning defects. In the ld ridge, fibroblast growth factor 8 (Fgf8) RNA is decreased and Fgf4 RNA is not detected. In the ld mesenchyme, Sonic hedgehog (Shh), Evx1 and Wnt5a expression is decreased. In chimeras between ld ectoderm and wild-type mesenchyme, a ridge of normal morphology and function is restored, Fgf8 and Shh are expressed normally, Fgf4 is induced and a normal skeletal pattern arises. These results suggest that the ld mesenchyme is unable to induce the formation of a completely functional ridge. This primary defect causes a disruption of ridge function and subsequently leads to the patterning defects observed in ld limbs. We propose a model in which ridge induction requires at least two phases: an early competence phase, which includes induction of Fgf8 expression, and a later differentiation phase in which Fgf4 is induced and a morphological ridge is formed. Ld proteins appear to act during the differentiation phase.

Pancreatic adenocarcinoma: CT versus MR imaging in the evaluation of resectability--report of the Radiology Diagnostic Oncology Group

PURPOSE

To compare findings with computed tomography (CT) and magnetic resonance (MR) imaging in pancreatic adenocarcinoma and to determine optimal pulse sequences for MR imaging.

MATERIALS AND METHODS

CT scans and MR images were compared of 189 adult patients with known or suspected adenocarcinoma of the pancreas. Levels of confidence were correlated with surgical and pathologic results.

RESULTS

The accuracy of CT was 0.73 and of MR imaging was 0.70. The negative predictive value of CT was 0.28 and of MR imaging was 0.23. The positive predictive value of CT was 0.89 and of MR imaging was 0.88. Gradient-echo and T1-weighted spin-echo sequences ranked equally in evaluation of vascular invasion, T1-weighted spin-echo sequences were preferred for assessing lymphadenopathy, and T2-weighted spin-echo sequences were preferred for detecting hepatic metastases.

CONCLUSIONS

Cross-sectional imaging modalities are useful in the identification of unresectable pancreatic carcinoma. CT is recommended for initial imaging assessment.

Digital chest radiography: comparison of unprocessed and processed images in the detection of solitary pulmonary nodules

PURPOSE

To compare the accuracy with which simulated solitary pulmonary nodules can be identified on digital images of the chest that are unprocessed, processed with adaptive spatial filtering, or processed with global filtering.

MATERIALS AND METHODS

Six experienced chest radiologists evaluated 408 test radiographs (136 from each of the three types, half with simulated nodules) and judged whether a nodule was present. Data from the 2,448 observations were evaluated by means of a receiver operating characteristic curve with location methods.

RESULTS

Accuracy was significantly better with the adaptive filter technique than with the global technique (P < .05), and it was better with adaptive filtering than with no processing in the detection of pulmonary nodules in the mediastinal-subdiaphragmatic areas (P < .05). No significant difference was found between no processing and global filtering.

CONCLUSION

Adaptive filtration is superior to global filtration in the identification of solitary pulmonary nodules and is superior to no processing in nodules projected over the radiopaque areas of the thorax on digital images.

T-cell lymphokine response to orally administered proteins during priming and unresponsiveness

Feeding antigens induces an immunological unresponsiveness termed oral tolerance but under some conditions, for example following the administration of cyclophosphamide (CY), immunity can be induced. These observations have usually been made by studying antibody production and delayed hypersensitivity with little attention given to other measurements of cellular activation. We have therefore examined the lymphokines produced by T cells obtained after the induction of oral tolerance or intragastric priming. Cells isolated from the spleen and Peyer's patches (PP) of tolerized mice could secrete high levels of interferon-gamma (IFN-gamma) and moderate levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) in response to antigen while interleukin-2 (IL-2), IL-3 and IL-4 could not be detected. Mesenteric lymph node (MLN) cells of tolerized mice did not respond to antigen unless spleen adherent cells were added to the cultures where IFN-gamma and GM-CSF were produced. Intragastric priming was achieved by feeding antigen to CY-treated mice. T cells from the spleen, MLN and PP of these mice could produce GM-CSF, IFN-gamma, some IL-3 but little or no IL-2 and IL-4. The ability of MLN cells to proliferate with antigen in vitro was low and corresponded to low IL-2 production. Thus T cells from fed mice secrete a defined pattern of lymphokines which differs in tolerizing and priming regimes.

CT evaluation following Whipple procedure: potential pitfalls in interpretation

A series of 41 CT examinations in 14 patients who had undergone a Whipple procedure for pancreatic cancer followed by adjuvant chemotherapy and radiation therapy were reviewed to determine the spectrum of CT findings, as well as to identify potential sources of error in interpretation. Thickening of the wall of the gastric antrum and proximal duodenum from 5 to 10 mm (9 of 14 patients) occurred as early as 1 month after completion of radiotherapy and simulated recurrent tumor. Unopacified anastomotic bowel loops in the porta hepatis in 23 of 41 examinations (56%) also mimicked recurrent tumor or adenopathy. Five of 14 patients showed liver metastases and 4 of 14 had recurrent disease in the pancreatic bed. Pneumobilia (33 of 41 examinations) was a frequent normal finding.

Computed tomography of uterine sarcomas

Uterine sarcomas are rare tumors, comprising only 2% of uterine malignancies. Abdominal and pelvic computed tomography (CT) of 14 patients with pathologically proven uterine sarcomas were reviewed. The average age of patients in our series was 64 years. The primary tumor measured between 4 and 30 cm. CT characteristics of uterine sarcomas included a low density mass within the uterine cavity in 12 of 14 cases. In two cases the mass was nearly isodense with uterus. Tumor necrosis was present in eight cases. Two patients presented with sarcomatosis, two demonstrated nodal spread, and one had liver metastases. Hydronephrosis was seen in three cases.