Effects of global or targeted deletion of the EP4 receptor on the response of osteoblasts to prostaglandin in vitro and on bone histomorphometry in aged mice

Because global deletion of the prostaglandin EP4 receptor results in neonatal lethality, we generated a mouse with targeted EP4 receptor deletion using Cre–LoxP methodology and a 2.3 kb collagen I a1 promoter driving Cre recombinase that is selective for osteoblastic cells. We compared wild type (WT), global heterozygote (G-HET), targeted heterozygote (T-HET) and knockout (KO) mice. KO mice had one targeted and one global deletion of the EP4 receptor. All mice were in a mixed background of C57BL/6 and CD-1. Although there were one third fewer G-HET or KO mice at weaning compared to WT and T-HET mice, G-HET and KO mice appeared healthy. In cultures of calvarial osteoblasts, prostaglandin E₂ (PGE₂) increased alkaline phosphatase (ALP) activity in cells from WT mice, and this effect was significantly decreased in cells from either G-HET or T-HET mice and further decreased in cells from KO mice. A selective agonist for EP4 receptor increased ALP activity and osteocalcin mRNA levels in cells from WT but not KO mice. A selective COX-2 inhibitor, NS-398, decreased osteoblast differentiation in WT but not KO cells. At 15 to 18 months of age there were no differences in serum creatinine, calcium, PTH, body weight or bone mineral density among the different genotypes. Static and dynamic histomorphometry showed no consistent changes in bone volume or bone formation. We conclude that expression of the EP4 receptor in osteoblasts is critical for anabolic responses to PGE₂ in cell culture but may not be essential for maintenance of bone remodeling in vivo.     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Suppressed Accumulation of Cerebral Amyloid β Peptides in Aged Transgenic Alzheimer’s Disease Mice by Transplantation with Wild-Type or Prostaglandin E2 Receptor Subtype 2-Null Bone Marrow

A complex therapeutic challenge for Alzheimer’s disease (AD) is minimizing deleterious aspects of microglial activation while maximizing beneficial actions, including phagocytosis/clearance of amyloid β (Aβ) peptides. One potential target is selective suppression of microglial prostaglandin E₂ receptor subtype 2 (EP2) function, which influences microglial phagocytosis and elaboration of neurotoxic cytokines. To test this hypothesis, we transplanted bone marrow cells derived from wild-type mice or mice homozygous deficient for EP2 (EP2^−/−) into lethally irradiated 5-month-old wild-type or APPswe-PS1ΔE9 double transgenic AD mouse model recipients. We found that cerebral engraftment by bone marrow transplant (BMT)-derived wild-type or EP2^−/− microglia was more efficient in APPswe-PS1ΔE9 than in wild-type mice, and APPswe-PS1ΔE9 mice that received EP2^−/− BMT had increased cortical microglia compared with APPswe-PS1ΔE9 mice that received wild-type BMT. We found that myeloablative irradiation followed by bone marrow transplant-derived microglia engraftment, rather than cranial irradiation or BMT alone, was responsible for the approximate one-third reduction in both Aβ plaques and potentially more neurotoxic soluble Aβ species. An additional 25% reduction in cerebral cortical Aβ burden was achieved in mice that received EP2^−/− BMT compared with mice that received wild-type BMT. Our results provide a foundation for an adult stem cell-based therapy to suppress soluble Aβ peptide and plaque accumulation in the cerebrum of patients with AD.Alzheimer’s disease (AD), the most common dementing neurodegenerative disease,¹ is a major public health burden for older Americans.² Amyloid β (Aβ) peptides are pleotropic molecules that are directly neurotoxic and stimulate liberation of cytotoxic cytokines through activation of microglia innate immune response.³ However, activated microglia phagocytosis and degradation of Aβ species is key to cerebral Aβ homeostasis.⁴ Thus, an important but complex therapeutic challenge is balancing deleterious and beneficial aspects of microglial activation in AD.⁵ One proposed mechanism of microglial modulation is prostaglandin E₂ signaling, especially through activation of the E prostanoid receptor subtype 2 (EP2).⁶ Cultured microglia lacking EP2 (EP2^−/−) show enhanced phagocytosis of Aβ from human brain explants and reduced paracrine neurotoxicity.⁷ In vivo experiments with EP2^−/− mice have shown reduced accumulation of cerebral Aβ in a transgenic mouse model of AD,^7,8,9 as well as suppressed oxidative damage to neurons following innate immune activation.^7,10,11,12 However, because EP2 is expressed by several cell types in brain, including microglia and neurons, the importance of microglial-specific EP2 has not been established. To address this gap in our knowledge, bone marrow cells from EP2^−/− mice were transplanted into APPswe-PS1ΔE9 mice.Circulating bone marrow transplant (BMT)-derived cells can selectively replace resident microglia,¹³ and up to 30% of microglia can be derived from donor marrow in wild-type mice recipients up to a year after transplantation.^14,15 Moreover, engraftment of brain appears qualitatively more efficient in recipient AD mice than in wild-type controls.^16,17 The reasons for the apparent higher engraftment are not clear, but may be in response to chronic low level immune activation in AD mouse brains.^16,17 Some investigators have shown BMT-derived microglia associated with Aβ deposits in vivo, and that transgenic AD mouse BMT recipients have reduced Aβ plaque burden.¹⁷ Although previous data addressed potential mechanisms by which BMT-derived microglia might promote clearance of Aβ peptides,¹⁸ the results of these studies were confounded by the effects of preconditioning brain irradiation; it is possible that the reduced Aβ plaque burden was caused by irradiation-induced alteration of Aβ production or clearance rather than BMT-derived microglia. In the current studies, we robustly quantify microglial engraftment in brains of APPswe-PS1ΔE9 mice. In addition, we control for the potential confounder of irradiation-mediated Aβ peptide suppression by evaluating Aβ in mice that received cranial-specific irradiation with or without BMT. Finally, we test the hypothesis that BMT with cells from EP2^−/− mice would enhance cerebral bone marrow derived microglia engraftment and clearance of Aβ peptides from cerebrum of APPswe-PS1ΔE9 mice.     

Phantom Sensations: A Neurophenomenological Exploration of Body Memory

This paper brings neuroscientific experiments into relation with concepts from phenomenological philosophy to investigate phantom sensations from the perspective of embodied subjectivity. Using a mirror device to create intersensory effects in subjects experiencing phantom sensations, one can create illusions aiming at alleviating phantom pain. Neuroplasticity as a general property of the brain and cortical remapping as a specific mechanism underlying the success of this procedure are interpreted with the phenomenological notions of body image, body schema, and body memory. It is argued that a phantom can be understood as an ambiguous unity of body-imagistic neglect and body-schematic remembering. This neurophenomenological approach highlights the significance of the polarity of subjective-objective embodied experience one the one hand, and the spatial and temporal horizons of the emergence of phantoms on the other. Thereby, implicit and explicit forms of remembering, habitual and reflective modes of behavioural and cognitive self-representation and -understanding can be compared according to how the body integrates its various sensations.

     

Elevation of cerebrospinal fluid soluble CD27 levels in patients with meningeal localization of lymphoid malignancies [published erratum appears in Blood 1996 Oct 1;88(7):2818]

Diagnosis of meningeal localization of lymphoid malignancies by means of cytologic examination of the cerebrospinal fluid (CSF) can be difficult. Thus far no reliable CSF tumor markers have been identified. CD27 is a transmembrane disulfide-linked 55-kD homodimer present on most peripheral blood T cells and on a subset of B cells. CD27 is also expressed on human malignant B cells and high levels of soluble CD27 can be present in the serum of patients with B-cell malignancies. The aim of this study is to determine prospectively the diagnostic value of CSF sCD27 as a tumor marker in patients with meningeal localization of lymphoid malignancies. CSF sCD27 levels were determined by sandwich enzyme-linked immunosorbent assay. The optimal cut-off value using receiver operator characteristics curves was found to be 10 U/mL. sCD27 levels were normal in all 50 control patients (lumbar disc protrusion) and in 39 of 40 samples obtained from patients with either solid tumors or acute myeloid leukemia. Of 104 CSF samples from 70 children with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) undergoing routine central nervous system (CNS) staging, sCD27 was false positive and false negative in only one sample each. In 70 samples from 45 patients suspected of meningeal localization of ALL or NHL, the sCD27 test had an excellent sensitivity (100%) and specificity (82%). In 7 patients with positive CSF studied longitudinally, sCD27 levels correlated very well with remission and relapse. sCD27 levels were not nonspecifically increased by the administration of cytostatic drugs. Finally, sCD27 was also elevated in the 4 patients studied with primary central nervous system lymphoma (PCNSL). CSF sCD27 is a promising tumor marker in patients with either meningeal localization of lymphoid malignancies or PCNSL, and can be useful in the differential diagnosis of CNS involvement by either lymphoid malignancies or solid tumors.     

Infiltrative lamina propria invasion pattern as an independent predictor for cancer‐specific and overall survival of instillation treatment‐naïve stage T1 high‐grade urothelial bladder cancer

Objectives

To investigate established prognostic factors and relatively new histopathological tumor characteristics including metric substage and lamina propria invasion patterns in a large series of T1 high‐grade non‐muscle‐invasive bladder cancer.

Methods

Between 1989 and 2012, 322 patients with initial stage T1 high‐grade bladder cancer underwent transurethral resection, followed by re‐transurethral resection and a conservative approach with follow‐up regime alone or instillation treatment. Transurethral resection specimens were reassessed by two experienced urological pathologists for tumor grade according to the World Health Organization 1973 classification, metric T1 substage, lamina propria invasion pattern and associated carcinoma in situ. The median follow‐up period was 42 months (interquartile range 25–72 months). In addition to Kaplan–Meier analyses, uni‐ and multivariable Cox regression analyses were used to compare progression‐free survival, cancer‐specific survival and overall survival for the studied parameters comparing two subcohorts.

Results

While in patients after instillation treatment no examined feature was shown as an independent predictor for prognosis, there were predictive histopathological features in multivariable Cox regression analyses in instillation treatment‐naïve patients: associated carcinoma in situ (hazard ratio 2.278, 95% confidence interval 1.119–4.634, P = 0.023) and World Health Organization 1973 grade 3 (hazard ratio 2.950, 95% confidence interval 1.021–8.536, P = 0.046) for worse progression‐free survival, infiltrative lamina propria tumor pattern for worse cancer‐specific survival (hazard ratio 2.369, 95% confidence interval 1.034–5.429, P = 0.042) and overall survival (hazard ratio 1.049, 95% confidence interval 1.024–1.075, P = 0.001).

Conclusions

The results of the present T1 high‐grade bladder cancer series suggest that lamina propria invasion pattern is a promising parameter to predict the prognosis of T1 high‐grade bladder cancer in an instillation treatment‐naïve subcohort. Prospective multicenter evaluations are warranted. The need for instillation treatment in T1 high‐grade bladder cancer is clearly demanded.