Expression of a 1,25-dihydroxyvitamin D3 membrane-associated rapid-response steroid binding protein during human tooth and bone development and biomineralization.

The calciotropic hormone 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] has been established to control skeletal tissue formation and biomineralization via the regulation of gene expression. This action involves the well-characterized nuclear 1,25(OH)2D3 receptor. However, it has been recognized that several cellular responses to 1,25(OH)2D3 may not to be related to the exclusive nuclear receptor. Indeed, this secosteroid is able to generate rapid responses that have been proposed to be mediated by interactions of the ligand, which is a putative cell membrane-associated rapid-response steroid (MARRS) binding protein for 1,25(OH)2D3 [1,25D3-MARRS]. The nongenomic pathway of 1,25(OH)2D3 was studied here in detail by immunolocalization of the 1,25D3-MARRS during the specific context of human prenatal development. Western blotting with proteins extracted from 4 week- to 27-week-old embryos was performed, evidencing a 65-kDa molecular species recognized by antibody Ab 099 generated against synthetic peptides corresponding to the N terminus of the 1,25D3-MARRS from chick intestinal basolateral membranes. Based on this biochemical conservation of protein in the human species, the temporospatial expression patterns were established in the craniofacial skeleton at the same ages. Comparative analysis was performed in teeth and bones from early morphogenesis to terminal cell differentiation and extracellular biomineralization. The data show the potential implication of 1,25D3-MARRS in the heterogeneous cell population including ameloblasts, odontoblasts, osteoblasts, and osteoclasts. The epithelial-mesenchymal cascade related to odontogenesis was coincident with a sequence of up- and down-regulation of immunoreactive 1,25D3-MARRS. Biomineralization was associated with a striking up-regulation in the adjoining secretory cells in all tissues. Finally, osteoclasts appeared also to express the 1,25D3-MARRS during these early phases of bone modeling. Previously obtained data of the nuclear vitamin D receptor (VDR) expression and this study on 1,25D3-MARRS suggest the existence of cross-talk between the genomic and nongenomic pathways during human development.     

Adeno-associated virus vector-mediated systemic delivery of IFN-beta combined with low-dose cyclophosphamide affects tumor regression in murine neuroblastoma models.

PURPOSE: Type I IFNs (IFN-alpha/beta) have shown significant antitumor activity in preclinical models but limited efficacy and significant toxicity in clinical trials. We hypothesized that the antitumor activity of type I IFNs could be enhanced by chronic, low-dose systemic delivery and sought to test this in murine neuroblastoma models. EXPERIMENTAL DESIGN: Continuous liver-generated expression of human IFN-beta (hINF-beta) was achieved through a gene therapy-mediated approach using adeno-associated virus vectors encoding hIFN-beta (AAV hINF-beta). Orthotopic localized retroperitoneal and disseminated models of neuroblastoma were established using three different xenografts. Immunohistochemical analysis and ELISA were used to evaluate the antiangiogenic effect of therapy. RESULTS: The development of both localized orthotopic (retroperitoneal) and disseminated neuroblastoma was prevented in all mice expressing hINF-beta. Continued growth of established retroperitoneal tumors, treated with AAV hINF-beta as monotherapy, was significantly restricted, and survival for mice with established, disseminated disease was significantly prolonged following administration of AAV hINF-beta. Analysis of treated tumors revealed a significant antiangiogenic effect. Mean intratumoral vessel density was diminished and expression of the angiogenic factors vascular endothelial growth factor and basic fibroblast growth factor were both decreased. Finally, combination therapy in which AAV hIFN-beta was used together with low-dose cyclophosphamide resulted in regression of both established retroperitoneal and disseminated disease. CONCLUSIONS: AAV-mediated delivery of hIFN-beta when used as monotherapy was able to restrict neuroblastoma growth due in part to inhibition of angiogenesis. When used in combination with conventional chemotherapy, AAV hIFN-beta was able to effect complete tumor regression.     

Improving recovery following cardiac surgery: a randomized clinical trial*

To enhance individual and family health during recovery from heart surgery, this study employed nursing interventions based on self-efficacy and family stress theory during the hospitalization period and for 3 months thereafter. The effectiveness of the interventions were assessed through a randomized trial in which 67 prospective bypass and valve surgery patients, aged 30-77 years, and their spouses, were allocated either the experimental interventions or usual care and followed for 6 months. At 3 months post-surgery, the only statistically significant differences between the experimentals and controls were on perceived self-efficacy for lifting and tolerating emotional distress. At 6 months no significant differences were found on individual or family measures. Analyses revealed that age, gender and preoperative cardiac status significantly affected individual recovery. The study is continuing with a larger sample in order to explicate the recovery process and to better determine whether a low intensity nursing intervention can effect changes in individual and family recovery.     

An Inbred Epilepsy-Prone Substrain of BALB/c Mice Shows Absence of the Corpus Callosum, an Abnormal Projection to the Basal Forebrain, and Bilateral Projections to the Thalamus

BALB/c mice lack a corpus callosum in about 11% of the population.Two inbred substrains of BALB/c mice, epilepsy-prone (EP) andepilepsy-resistant (ER), have been examined to determine whetherthese substrains differ in regard to corpus callosum morphology.Further, this study addressed the issue of whether misroutedcortical axons form an aberrant pathway instead of the corpuscallosum. Initial studies that examined fresh brain tissue ofadult animals revealed normal corpora callosa in all ER micebut deficient or absent corpora callosa in all EP mice. Subsequently,Dil crystals were placed in the motor cortices of aldehyde-fixedbrains of 2-week-old animals to investigate cortical projectionsin both inbred substrains of mice. Fluorescent microscopy revealedthat all of the ER animals had normal corpora callosa, whereasall EP animals exhibited either reduced corpora callosa (partiallycallosal) or an absence (acallosal) of this structure. Bothacallosal and partially callosal EP mice displayed an extensive,aberrant projection to the basal forebrain as well as bilateralprojections to midline and intralaminar thalamic nuclei. Thefibers projecting to the basal forebrain arose from the cortex,coursed toward the midline before turning ventrally along themidline, and appeared to terminate in the medial septal nucleusand the nucleus of the diagonal band. ER animals lacked thisaberrant cortical projection to the basal forebrain. Electronmicroscopic results obtained from EP mice indicated that labeledaxons in this aberrant pathway formed axosomatic, axodendritic,and axospinous synapses with the neurons in the medial septal/diagonalband complex. The function of the aberrant projection to thebasal forebrain remains unknown but it may provide an abnormalexcitatory input to a region that provides cholinergic and GABAergicinput to the cerebral cortex and hippocampus. The additionalprojections to midline and contralateral intralaminar thalamicnuclei in EP mice may function to intensify the synchronizationof bilateral discharges.