Novel Fluorinated Hybrid Polymer by Radical Polyaddition of Bis(α‐trifluoromethyl‐β,β‐difluorovinyl) Terephthalate onto Dialkoxydialkylsilanes

To develop the radical polyaddition of bisperfluoroisopropenyl esters, the reactions of bis(α‐trifluoromethyl‐β,β‐difluorovinyl) terephthalate [CF₂?C(CF₃)OCOC₆H₄COOC(CF₃)?CF₂] (BFP) with dialkoxydialkylsilane were examined to prepare fluorinated hybrid polymers bearing dialkylsilyl groups in the main chain. Prior to polyaddition, the radical addition reaction of 2‐benzoyloxypentafluoropropene [CF₂?C(CF₃)OCOC₆H₅] (BPFP) has been investigated to afford the results that diethoxydimethylsilane (DEOMS) or dimethoxydimethylsilane with BPFP initiated by oxo radical are the best combination for the preparation of polymers. The mechanism of the addition reaction was proposed. Radical polyaddition of BFP with DEOMS initiated by benzoyl peroxide or di‐tert‐butyl peroxide has yielded polymers of up to molecular weight 1 × 10⁶ with rather broad molecular weight distribution. A mechanism for the polyaddition reaction is proposed based on the radical addition reaction between BPFP and DEOMS. The step‐growth polymerization is initiated by hydrogen abstraction of DEOMS to add a perfluoroisopropenyl group, followed by a 1,7‐shift of the radical in the intermediate. The relationship between addition reaction mechanism and polyaddition mechanism was also discussed.

     

Ras homolog gene family H (RhoH) deficiency induces psoriasis-like chronic dermatitis by promoting TH17 cell polarization

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Behaviour of permeation and separation for aqueous organic acid solutions through poly(vinyl chloride) and poly[(vinyl chloride)-co-(vinyl acetate)] membranes

The permeation and separation characteristics of poly(vinyl chloride) (PVC) and poly[(vinyl chloride)-co-(vinyl acetate)] (poly(VC-co-VAc)) membranes were investigated for aqueous organic acid solutions by pervaporation and evapomeation. The PVC membrane preferentially incorporates organic acids and predominantly permeates water from aqueous organic acid solutions. Water permselectivities of these aqueous solutions through the PVC membrane are significantly dependent on high diffusivity of water across the membrane. It was found that the permeation rate increases and the separation factor for the water permselectivity decreases with increasing vinyl acetate (VAc) content in the poly(VC-co-VAc) membrane. Preferential solubility of acetic acid into the poly(VC-co-VAc) membrane increases with the VAc content. This result was explained by a strong affinity between acetic acid and the VAc unit in the poly(VC-co-VAc) membrane.     

Heterotopic transplantation of the failing rat heart as a model of left ventricular mechanical unloading toward recovery

The left ventricular assist device (LVAD) is usually used in patients with end-stage heart failure as a bridge to transplantation. Recently, some studies have reported functional recovery with the use of an LVAD, although the mechanisms responsible for recovery are not fully understood. We investigated the functional recovery of the infarcted, failing rat heart in response to mechanical unloading after heterotopic transplantation. Heart failure was induced in Lewis rats by ligating the left anterior descending artery. After 4 weeks, the infarcted hearts were harvested and heterotopically transplanted. The transplanted infarcted heart was removed after 2 weeks of unloading and examined for hypertrophy and fibrosis, as well as for mRNA levels encoding for brain natriuretic peptide, sarco(endo)plasmic reticulum Ca(2+)-ATPase2a (SERCA2a), and beta1- and beta2-adrenergic receptors. Normal and infarcted rats without transplantation served as control animals. The infarcted heart was hypertrophied as evidenced by an increase in heart weight and myocyte diameter. After unloading the infarcted heart for 2 weeks, there was a decrease in heart weight and myocyte diameter. However, the percentage of myocardial fibrosis increased after unloading. The mRNA expression of brain natriuretic peptide and the beta2-adrenergic receptor significantly improved after mechanical unloading. The levels of SERCA2a mRNA tended to increase after unloading. In conclusion, unloading the failing, infarcted heart can help normalize left ventricular hypertrophy and cardiac gene expression. This unloading model appears to partially mimic the conditions of hemodynamic support with an LVAD in heart failure patients and potentially offers insights into the mechanisms of functional recovery.     

Structural dependence of apatite formation on titania gels in a simulated body fluid

The apatite-forming ability of titania gels with different structures has been investigated in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma. Titania gels with an amorphous structure or with an anatase or rutile structure were prepared by the sol-gel process with a subsequent heat treatment at various temperatures. The titania gels with an amorphous structure did not induce apatite formation on their surfaces in the simulated body fluid, whereas gels with an anatase or rutile structure induced apatite formation on their surfaces. The deposition of apatite was more pronounced on the anatase gels than on the rutile gels. This indicates that a specific structure of titania is effective in inducing apatite formation in a body environment. Such a specific structure was assumed in this study to be the crystalline planar arrangement in the anatase structure, which facilitates epitaxy of the apatite crystal.     

B-cell repertoire specific for an unfolded self-determinant of mouse lysozyme escape tolerance and dominantly participate in the autoantibody response

We previously found that autoantibodies against mouse lysozyme (ML) were strongly induced in normal BALB/c mice when immunized with mutant ML that has triple mutations rendering the dominant T-cell epitope of hen egg lysozyme (HEL), HEL 107-116. As T cells specific for HEL 107-116 were primed in these mice, the anti-ML immunoglobulin G (IgG) responses would be the result of collaborations between autoreactive B cells specific for ML and T cells specific for HEL 107-116. Serum IgG responses against ML were dominantly focused on the ML 14-69 region, indicating that B cells responding to the epitope escape tolerance. In the present study, we prepared several monoclonal antibodies (mAbs) specific for ML 14-69 and examined their antigen specificities in detail, to characterize the nature of the remaining B-cell repertoire specific for ML. mAbs specific for ML 14-69 interacted weakly with soluble, native ML, but the interactions were strengthened by denaturation of ML. The apparent affinity constants between these mAbs and ML showed an increase, ranging from six- to 80-fold, by denaturation of ML. Therefore, these mAbs were more specific for the denatured determinant than for the determinant in the native structure. These results indicate that a substantial number of autoreactive B cells, specific for the unfolded conformation of ML, escape tolerance and are dominantly involved in the autoantibody response to ML. Our finding provides important information to understand the naturally occurring autoreactive B-cell repertoire in normal mice.     

T-cell variant of classical Hodgkin's lymphoma with nodal and cutaneous manifestations demonstrated by single-cell polymerase chain reaction

The atypical cells of CD30(+) cutaneous lymphoproliferative disorders (CD30CLD) are commonly of T-cell origin and frequently have a similar morphology as Hodgkin or Reed-Sternberg cells of Hodgkin's lymphoma (HL). HL is one of the tumors associated with CD30CLD. Although most studies support a B-cell derivation of the tumor cells in HL, recently a few cases of classical HL with T-cell genotype have been reported. We report a patient who presented with CD30CLD whose lymph nodes showed classical HL of mixed cellularity subtype at presentation. By single-cell PCR, the same clonal gene rearrangements of the T cell receptor-beta gene locus could be assigned to the CD30(+) and CD15(+) cells of both skin and lymph node. In a lymph node biopsy specimen taken in relapse after several courses of chemotherapy, the CD30(+) tumor cells were abundant. The T cell-derived tumor cells displayed aberrant expression of the Pax-5 gene in all specimens. A common clonal origin of both CD30CLD and HL of the lymph node in the patient presented here suggests that HL with T-cell genotype exists in association with CD30CLD as well as in sporadic cases and may share clonal origin with the skin tumor.     

Expression of insulin-like growth factor 1 receptor in primary breast cancer: immunohistochemical analysis

Insulin-like growth factor-1 receptor (IGF-1R) has been implicated in regulation in tumor growth. The results of previous studies performed by radioimmunoassay are conflicting, and the prognostic significance of IGF-1R expression in primary breast cancer is still controversial. IGF-1R expression was evaluated in formalin-fixed, paraffin-embedded tissue of 210 primary breast cancer patients by using anti-IGF-1R antibody. The clinicopathologic variables and 5-year disease-free survival were studied, and their correlations between IGF-1R expressions were investigated. IGF-1R overexpression was observed in 43.8% of tumors. IGF-1R overexpression had no correlation with prognosis or with other clinicopathologic parameters, such as age, tumor size, nodal status, histologic grade, hormone receptor status, and human epidermal growth factor 2 status. Though its prognostic value in breast cancer is limited, immunohistochemical evaluation of IGF-1R by using this monoclonal antibody may be useful in translational research using archived material.     

Significance of fibrils in the formation of the Kimmelstiel-Wilson nodule

Summary The pathogenesis of the nodular lesion in diabetic glomerulosclerosis is described in association with fibrils. Thirteen diabetic patients with glomerular nodular lesions and 9 diabetics without the nodules were examined by electron microscopy using periodic acid-thio-carbohydrazide-silver proteinate staining. In cases of nodular glomerulosclerosis, abundant fibrillar structures mixed with electron-dense material were detected within the nodule and the mesangial matrix. They were also occasionally observed along the subendothelial space of the glomerular capillary walls. On the cross-section, these fibrils, including the lucent periphery, were 34 nm wide. Immunohistologically, collagen V and collagen VI were detected in nodular lesions. In contrast, in cases of the diffuse type of glomerulosclerosis, the widened mesangium was composed of dense material, which resembled the original mesangial matrix. The above fibrils were not detected in the mesangium. These findings suggest that the accumulation of the peculiar fibrils in the glomerular mesangium is a major pathogenic factor in the formation of Kimmelstiel-Wilson nodules.     

Lamivudine and IFN-beta sequential therapy in HBe antigen-positive patients with chronic hepatitis B virus genotype C infection.

Sequential treatment with lamivudine and interferon (IFN) has induced sustained biochemical and virologic responses in the majority of patients with chronic hepatitis B in France. However, the efficacy of sequential treatment in patients with chronic hepatitis B virus (HBV) genotype C infection has not been evaluated. Twenty-four HBe antigen-positive patients were treated with 100 mg lamivudine alone for 16-32 weeks, then with both 6 MU IFN-beta and lamivudine for 4 weeks, and lastly with IFN-beta alone for 20 weeks. Sustained response was achieved in 7 (29%) patients 24 weeks after the end of therapy. No lamivudine-resistant variants emerged in any patient. Hepatitis flare occurred in 3 patients after the withdrawal of lamivudine, but none had decompensation. The patients with sustained response were significantly younger at baseline (p = 0.033) and had a significantly lower HBV DNA level at the start of IFN (p = 0.020) than those without sustained response. In conclusion, the rate of response to sequential therapy with lamivudine and IFN in HBe antigen-positive patients with HBV genotype C infection was lower than the rate reported previously. Patients who were young or who had a favorable virologic response to lamivudine were more likely to have a sustained response.