Corneal disorders in KKAy mouse: a type 2 diabetes model

PURPOSE: To observe the clinical and histopathological changes occurring in corneas of KKAy mice, a model of type 2 diabetes, and to elucidate the possible mechanisms involved in these changes. METHODS: Corneal epithelial cell proliferation was analyzed in KKAy and age-matched non-diabetic C57BL/6J control mice using (3)H-thymidine autoradiography. Clinical examination and histopathological analysis were also conducted on both types of mice. RESULTS: KKAy mice showed a significant elevation in blood glucose concentration and body weight compared to age-matched control mice. Fragile corneal epithelial cell attachment and subepithelial opacities were observed in the central area of the cornea of 10-week-old KKAy mice. Corneal epithelial cell proliferation decreased significantly in the 16-week-old KKAy mice. Histological study in the older KKAy mice groups revealed the presence of subepithelial deposits, widening of the intracellular spaces between corneal epithelial cells with poor adherence to the basement membrane (BM) and thickening of the BM itself. At the central area of the cornea, remnants of cell components with deposits and lacuna formation were observed, perhaps secondary to the continuous presence of poor adhesion and detachment of epithelial cells in the area. In the 50-week and older KKAy mice, thinning and atrophy of the corneal epithelial cell layer became more prominent at the central cornea with increases in deposition of materials, blood vessel invasion and activation of keratocytes. The deposits were stained black by von Kossa's method, indicating the presence of tissue calcium. Type IV collagen immunoreactivity was observed not only in the corneal and conjunctival BM but also between the stroma, particularly around the central cornea and in the walls of invading vessels. Laminin staining was intense at the BM around the central cornea, and in the walls of invading vessels along the stroma. Pyrraline, which is one of the major components of advanced glycation end products, was also present in the stroma, and around blood vessels. All these corneal changes were not observed with aging in the age-matched C57BL/6J mice. CONCLUSIONS: Our findings provide evidence of the existence of corneal disorders in KKAy mice. These observations may provide useful information for the explanation of the mechanisms involved in corneal disorders in non-insulin-dependent diabetes mellitus patients.     

A macular hole in the eye of a young patient with retinitis pigmentosa

PURPOSE: To describe the histological and cytological findings in the epiretinal membrane around a macular hole. CASE: A 24-year-old male patient with retinitis pigmentosa had had night blindness since childhood. A macular hole(Stage 2) in his left eye was noted when he was 18 years old. He visited our department when he was 22 years old. The visual acuity on the left was 0.5 at the first examination and two years later it was 0.2 with enlargement of the macular hole. Pars plana vitrectomy was applied, and we removed the thick yellow epiretinal membrane around the hole. The macular hole was closed, and the visual acuity improved to 0.7. The removed membrane contained many cells including macrophages, Müller cells, glial cells, and fibroblasts. There were many granules that appeared to be xantophyll outside the cell bodies. CONCLUSION: The components of the membrane suggest that the macular hole was caused by vitreous degeneration due to retinitis pigmentosa.     

Clinical estimation of vancomycin measurement method on hemodialysis patient

The fluorescence polarization immunoassay (FPIA) method is used to perform measurement of vancomycin hydrochloride (VCM) at many institutions. However, the values measured by the FPIA method are more vulnerable to overestimation than the high performance liquid chromatography (HPLC) method. In particular, it was not reported to perform exact therapeutic drug monitoring (TDM) measurement. Since overestimation is likely in patients with renal dysfunction, the HPLC method is preferable for TDM measurement. This study investigates the clinical conditions that lead to overestimation in the FPIA method, paying attention to the relation of clinical laboratory data inspection values and the existence of hemodialysis (HD). Overestimation in the evaluation of TDM using the FPIA method was clinically examined with 116 serum samples obtained from 18 cases medicated with VCM. The relevance between overestimation of patients who had not had HD performed was 72.7 +/- 61.7% (means +/- SD). In short, the overestimation was greatest in HD patients. Since overestimation did not affect the evaluation of clinical TDM, such as an effect and a side-effect, the TDM of VCM was shown to be satisfactorily evaluated by the simple FPIA method.     

Rapid bactericidal activities of carbapenems against Pseudomonas aeruginosa in simulating human plasma concentrations

The rapid bactericidal activities of panipenem (PAPM), imipenem (IPM), and meropenem (MEPM) against Pseudomonas aeruginosa were investigated by using in vitro pharmacodynamic model simulating the human plasma concentrations after intravenous drip infusion at 500 mg for 0.5 hours. Against P. aeruginosa PAO1, PAPM and IPM showed rapider reduction in viable cell counts than MEPM at 0.5 hours after exposure. All drugs showed more than 3 log10 reduction in viable cell counts at 2 hours after exposure and bacterial regrowth was not observed throughout 6 hours. The initial bactericidal activities of the drugs against 4 clinical isolates within 1 hour after exposure were also investigated by the same method. Against P. aeruginosa strain 12,475, the 3 drugs showed similar initial bactericidal activity but PAPM and IPM showed stronger initial bactericidal activity than MEPM against the other strains as did against P. aeruginosa PAO1. The morphological change of a strain 12,489, for which the initial bactericidal activities were different largely, after 0.5 hours exposure to simulated drug-concentrations was investigated by scanning electron microscope. PAPM and IPM induced morphological changes in most of the cells and cell lysis and bulge formation. On the other hand, MEPM induced changes of the surface structure of cells and slightly elongated cells, but not cell lysis.     

2a-[4-(Tetrahydropyridoindol-2-yl)butyl]tetrahydrobenzindole derivatives: new selective antagonists of the 5-hydroxytryptamine7 receptor

A series of tetrahydrobenzindoles was prepared, and the affinity of these compounds for the 5-hydroxytryptamine7 (5-HT7) receptor and other receptors was evaluated. Most of the compounds showed high affinity for the 5-HT7 receptor, and 2a-[4-(tetrahydropyridoindol-2-yl)butyl]tetrahydrobenzindole derivatives (26a-j) exhibited high selectivity for this receptor. The nature of the substituent at the 9-position of the tetrahydropyridindole ring affected the affinity for the 5-HT7 receptor, and the 9-carbamoyl moiety afforded increased selectivity. Compound 26j exhibited high affinity for the 5-HT7 receptor, with at least 280-fold selectivity over the 5-HT2 receptor. In a functional model of 5-HT7 receptor activation, this compound was confirmed to have 5-HT7 receptor antagonist activity. It should be a useful tool for clarifying the biological role of the 5-HT7 receptor.     

Novel chondroitin sulfate-binding cationic liposomes loaded with cisplatin efficiently suppress the local growth and liver metastasis of tumor cells in vivo

An increased level of chondroitin sulfate (CS) expression on the cell surface is often associated with malignant transformation and the progression of tumor cells. In this study, CSs expressed on highly metastatic tumor cells were used as a target for the selective delivery of anticancer drugs by polyethylene glycol (PEG)-coated liposomes that contained a new cationic lipid 3,5-dipentadecycloxybenzamidine hydrochloride (TRX-20). We found that PEG-coated TRX-20 liposomes (TRX-20 liposomes) bound preferentially to certain CSs, such as CS B, CS D, and CS E, whereas PEG-coated liposomes lacking TRX-20 showed no significant binding to any of the glycosaminoglycans tested. In vitro, TRX-20 liposomes, but not plain PEG liposomes, avidly bound to and were readily internalized by highly metastatic tumor cells such as LM8G5 and ACHN cells, which express large amounts of CS on the cell surface. When TRX-20 liposomes were loaded with cisplatin, they effectively killed the CS-expressing tumor cells in vitro, whereas cisplatin-PEG liposomes lacking TRX-20 were totally ineffective. When injected systemically, TRX-20 liposomes preferentially accumulated in the liver and in solid s.c. LM8G5 tumors. Therapeutic experiments in mice bearing a s.c. LM8G5 tumor revealed that cisplatin-loaded TRX-20 liposomes were significantly more effective in reducing the local tumor growth than cisplatin-loaded plain PEG liposomes or free cisplatin. Furthermore, the cisplatin-loaded TRX-20 liposomes markedly suppressed metastatic spreading of LM8G5 tumor cells to the liver, significantly increasing the survival time of the tumor-bearing mice. These results demonstrate that the CS-targeted delivery of anticancer drugs by novel cationic liposomes represents a potentially useful strategy to prevent the local growth and metastasis, particularly to the liver, of tumor cells that have enhanced expression of CS.     

An 80-year-old woman with non-resectable pulmonary adenocarcinoma that responded to concomitant use of gemcitabine and vinorelbine

An 80-year-old female with non-resectable pulmonary adenocarcinoma was treated with five courses of chemotherapy consisting of gemcitabine (GEM) 1,000 mg/m2 plus vinorelbine (VNR) 25 mg/m2 (days 1 and 8, every 4 weeks). A partial response (PR) was achieved, and her complaints abated and quality of life (QOL) improved. Although gastro-intestinal symptoms and bone marrow suppression were observed as side effects, they were within a tolerable range and did not interfere with the therapy. Anti-cancer chemotherapy for non-resectable lung cancer might be worth consideration even for elderly patients more than 80 years of age.     

Monitoring of singlet oxygen is useful for predicting the photodynamic effects in the treatment for experimental glioma.

PURPOSE: Singlet oxygen ((1)O(2)) generated in photodynamic therapy (PDT) plays a very important role in killing tumor cells. Using a new near-IR photomultiplier tube system, we monitored the real-time production of (1)O(2) during PDT and thus investigated the relationship between the (1)O(2) production and photodynamic effects. EXPERIMENTAL DESIGN: We did PDT in 9L gliosarcoma cells in vitro and in an experimental tumor model in vivo using 5-aminolevulinic acid and nanosecond-pulsed dye laser. During this time, we monitored (1)O(2) using this system. Moreover, based on the (1)O(2) monitoring, we set the different conditions of laser exposure and investigated whether they could affect the tumor cell death. RESULTS: We could observe the temporal changes of (1)O(2) production during PDT in detail. At a low fluence rate the (1)O(2) signal gradually decreased with a low peak, whereas at a high fluence rate it decreased immediately with a high peak. Consequently, the cumulative (1)O(2) at a low fluence rate was higher, which thus induced a strong photodynamic effect. The proportion of apoptosis to necrosis might therefore be dependent on the peak and duration of the (1)O(2) signal. A low fluence rate tended to induce apoptotic change, whereas a high fluence rate tended to induce necrotic change. CONCLUSIONS: The results of this study suggested that the monitoring of (1)O(2) enables us to predict the photodynamic effect, allowing us to select the optimal laser conditions for each patient.     

Molecular Mechanisms Leading to the Phenotypic Development in Paternal and Maternal Uniparental Disomy for Chromosome 14

Human chromosome 14q32.2 carries a cluster of imprinted genes. They include paternally expressed genes (PEGs) such as DLK1 and RTL1, and maternally expressed genes (MEGs) such as GTL2 (alias, MEG3), RTL1as (RTL1 antisense), and MEG8. Consistent with this, paternal and maternal uniparental disomies for chromosome 14 (upd(14)pat and upd(14)mat) cause distinct phenotypes. In this review, we summarize the current knowledge about the underlying factors for the development of upd(14)pat and upd(14)mat phenotypes. The data available suggest that the DLK1-GTL2 intergenic differentially methylated region (IG-DMR) plays an important role in the maternal to paternal epigenotypic switch, and that excessive RTL1 expression and decreased DLK1 and RTL1 expression play a major role in the development of upd(14)pat-like and upd(14)mat-like phenotypes, respectively.     

Widespread Integration and Survival of Adult-Derived Neural Progenitor Cells in the Developing Optic Retina

Adult rat hippocampus-derived neural progenitor cells (AHPC) show considerable adaptability following grafting to several brain regions. To evaluate the plasticity of AHPCs within the optic retina, retrovirally engineered AHPCs were grafted into the vitreous cavity of the adult and newborn rat eye. Within the adult eye, AHPCs formed a uniform nondisruptive lamina in intimate contact with the inner limiting membrane. Within 4 weeks of grafting to the developing eye, the AHPCs were well integrated into the retina and adopted the morphologies and positions of Müller, amacrine, bipolar, horizontal, photoreceptor, and astroglial cells. Although the cells expressed neuronal or glial markers, none acquired end-stage markers unique to retinal neurons. This suggests that the adult-derived stem cells can adapt to a wide variety of heterologous environments and express some but not all features of retinal cells when exposed to the cues present late in retinal development.