Transgene expression in neonatal mouse inner ear explants mediated by first and advanced generation adenovirus vectors

The mouse serves as a valuable model for treatment leading to the prevention and therapy of inner ear disease. Transgenic correction of genetic inner ear disease in mice may help develop treatment for human genetic inner ear disease. In mutations involving hair cells (HCs) or supporting cells (SCs), it is necessary to insert the wild-type transgenes directly into these cells. We used inner ear explants to characterize the transgenic expression using adenovirus-mediated reporter genes (bacterial lacZ). The variable parameters were the age of the explants (P1-P5), the type of vector (first and advanced generation adenovirus) and the genotype of the mouse (wild-type versus shaker-2 mutant). Transduction of cochlear HCs was detected at P1 and in some of the P3 cochleae. Low efficiency transduction of SCs was observed in P1 explants, but the efficiency increased with age and reached high levels at P5. The pattern of transduction was similar regardless of the genotype and the type of vector used. The data demonstrate that differentiating HCs and SCs in mouse explants can be transduced by adenovirus vectors, suggesting that cultures of mouse ears are a valuable model for developing inner ear gene therapy protocols.     

Gene transfer into supporting cells of the organ of Corti

To utilize the rapidly accumulating genetic information for developing new therapeutic technologies for inner ear disease, it is necessary to design technologies for expressing transgenes in the inner ear, especially in the organ of Corti. We examined the outcome of an adenovirus gene transfer into the organ of Corti via the scala media in guinea pigs. The transgene insert is the bacterial lacZ gene driven by a cytomegalovirus promoter. We demonstrate that the inoculation is detrimental to the hair cells that surround the site of inoculation, but the supporting cells in the organ of Corti survive and retain the ability to express the reporter transgene beta-gal. The ability to deliver transgenes that are expressed in the supporting cells is an important step in the development of clinically applicable treatments that involve hair cell regeneration.     

Predominant role of FcgammaRIII in the induction of accelerated nephrotoxic glomerulonephritis

BACKGROUND: Nephrotoxic glomerulonephritis is induced by the administration of antibody against the glomerular basement membrane (GBM). We demonstrated previously that Fc receptors for immunoglobulin G (IgG) (FcgammaR) play crucial roles in the induction of accelerated nephrotoxic glomerulonephritis by using FcRgamma-deficient (-/-) mice. Since FcRgamma-/- mice lack the cell surface expression of two activating FcgammaRs, FcgammaRI and FcgammaRIII. The present study aims to identify the FcgammaR responsible for the induction of nephrotoxic glomerulonephritis. METHODS: Accelerated anti-GBM glomerulonephritis was induced in FcgammaRI-/-, FcgammaRIII-/-, and FcRgamma-/- mice by preimmunization with rabbit IgG followed by inoculation of rabbit anti-GBM antibody. Histologic analysis and immunostaining of renal sections were performed. RESULTS: FcgammaRI-/- mice as well as wild-type mice showed severe glomerulonephritis with hypernitremia by the administration of anti-GBM antibody. In contrast, FcgammaRIII-/- mice showed much milder renal involvement, similar to FcRgamma-/- mice. Histologically, FcgammaRI-/- mice showed intracapillary proliferation, glomerular thrombosis, and crescent formation, whereas FcgammaRIII-/- mice showed only glomerular hypercellular changes. The depositions of anti-GBM antibodies, autologous antibodies and complement C3 along the GBM were equally observed among all three FcR-/- mouse types by immunostaining. CONCLUSIONS: Accelerated nephrotoxic glomerulonephritis is induced predominantly through FcgammaRIII but not FcgammaRI.     

Magnetic resonance imaging of sequelae of central pontine myelinolysis in chronic alcohol abusers

Central pontine myelinolysis (CPM) is one of the serious neurological complications of alcoholism. This study evaluated magnetic resonance images of sequelae of CPM. Approximately 600 alcoholic patients were examined by a 1.0-T magnetic resonance imaging device, and 11 patients were retrospectively found to have a central pontine lesion, a presumed sequela of CPM. The lesions had various shapes and most were cavitary. In 3 of the 11 patients bilateral symmetrical oval lesions were faintly visible in the middle cerebellar peduncles. These middle cerebellar peduncular lesions were diagnosed as having Wallerian degeneration of the pontocerebellar tract secondary to CPM.     

A prospective survey of delayed adverse reactions to iohexol in urography and computed tomography

We investigated 7505 inpatients who underwent intravenous urography or contrast-enhanced computed tomography to assess risk factors for delayed adverse drug reactions to iohexol, a non-ionic iodinated contrast medium. Focusing on delayed adverse reactions, all adverse events were prospectively investigated for 7 days after injection of iohexol. To explore the relevant risk factors, the relationship between occurrence of adverse reactions to iohexol and 17 different variables was evaluated by logistic regression analysis. To assess the influence of seasonal factors, adverse reactions were separately evaluated during two periods: February to April (the pollinosis period in Japan) and July to September (the non-pollinosis period). The prevalence of delayed adverse events and delayed adverse reactions was 3.5 and 2.8%, respectively, whereas the prevalence of adverse events and adverse reactions was 5.7 and 5.0%, respectively. Multivariate analysis showed that six parameters had a significant influence on delayed adverse reactions to iohexol, including (a) a history of allergy, (b) season, (c) radiographic procedure, (d) age, (e) concomitant surgery or other invasive procedures, and (f) concomitant medication. The prevalence of delayed reactions was lower than in previous large-scale studies. Significant risk factors included a history of allergy and performance of radiography during the pollinosis period, suggesting that allergy was involved in delayed adverse reactions. The type of radiographic procedure also had an influence. Electronic Publication     

CD45RB-targeting strategies for promoting long-term allograft survival and preventingchronic allograft vasculopathy

BACKGROUND: CD45RB is a potent immunomodulatory target to achieve long-term allograft survival. We evaluated the in vivo effect of anti-CD45RB monoclonal antibody (mAb) treatment in combination with conventional immunosuppression or costimulatory blockade strategies as a therapeutic modality for future clinical application. METHODS: A fully MHC-mismatched vascularized mouse cardiac allograft model was used to test the interactions between anti-CD45RB mAb and conventional immunosuppressive drugs or costimulatory blockade of the CD40/CD154 or B7/CD28 pathway. Chronic rejection was examined histologically for development of chronic allograft vasculopathy. RESULTS: Cyclosporine significantly abrogated the effect of anti-CD45RB therapy. In contrast, rapamycin acted synergistically with anti-CD45RB mAb in promoting long-term allograft survival. CD154 blockade further enhanced the tolerogenic efficacy of anti-CD45RB mAb. These synergistic effects of combination treatments also prevented the development of chronic allograft vasculopathy. CONCLUSION: CD45RB-targeting strategy in combination with the use of rapamycin or costimulatory blockade promotes allograft tolerance and prevents chronic rejection.     

Effects of insulin-like growth factor I on climbing fibre synapse elimination during cerebellar development

Functional neural circuit formation includes the process by which redundant synaptic connections formed earlier during development are subsequently eliminated. We report that insulin-like growth factor I (IGF-I) is a candidate factor that influences the developmental transition from multiple to mono innervation of cerebellar Purkinje cells (PCs) by climbing fibres (CFs). Continuous local application of exogenous IGF-I to the mouse cerebellum by means of ethylene-vinyl acetate copolymer (Elvax) significantly increased the degree of multiple CF innervation, when the IGF-I containing Elvax was implanted at postnatal day 8 (P8). In contrast, the IGF-I application starting at P12 had no effect on CF innervation. Conversely, continuous local application of antisera against IGF-I and its receptor significantly decreased the degree of multiple CF innervation when the application started at P8. We found that chronic treatment of exogenous IGF-I from P8 significantly enhanced the CF-mediated excitatory postsynaptic currents (CF-EPSCs). This effect was manifest for the smaller CF-EPSCs but not for the largest CF-EPSC of the multiple-innervated PCs. Conversely, chronic application of antisera from P8 caused attenuation of the largest CF-EPSCs. Other parameters for basic synaptic functions and cerebellar morphology were largely normal after the IGF-I or antisera treatment. These results suggest that IGF-I enhances the strength of developing CF synapses and may promote their survival, whereas the shortage of IGF-I impairs the development of CF synapses and, as a result, may facilitate their elimination. Thus, IGF-I is a potentially important factor among various signalling molecules that can influence CF synapse elimination during cerebellar development.     

Intradural lumbar disc herniation. Report of three cases with a review of the literature

Intradural lumbar disc herniation (ILDH) is rare. Three new cases of this condition are reported, adding to the 70 previously documented cases. An incidence of ILDH in between 0.04 and 0.33 percent of lumbar disc protrusions has been reported. More than one third of ILDH were observed at L1-2 to L3-4 levels, while only a tenth of cases occurred at L5-S1. The mechanism of ILDH is not known with certainty. Adhesions between the ventral wall of the dura and posterior longitudinal ligament could act as a preconditioning factor. A diagnosis of ILDH may be made with difficulty, and it is seldom suspected preoperatively. Prompt surgery is necessary because the neurologic prognosis appears to be closely linked with preoperative duration of neurologic symptoms.