Apoptosis-inducing effect of a new bisphosphonate,YM529, on various hematopoietic tumor cell lines

In recent years, it has been reported that bisphosphonates inhibited the cell cycle of myeloma cells to inhibit cell proliferation directly, and it was also reported that bisphosphonates induced apoptosis of myeloma cells in vitro. Recently, YM529 was developed as a new third-generation bisphosphonate. In our experiment, we investigated whether YM529 showed an antitumor effect on hematopoietic tumor cell lines other than myeloma, and we compared YM529 with YM175, which had a relatively more potent antitumor effect than that of existing bisphosphonates. We found that YM529 inhibited cell proliferation in various hematopoietic tumor cell lines (acute promyelocytic leukemia cell line HL-60, chronic myeloid leukemia cell line K562, histiocytic lymphoma cell line U937, lymphoblastic leukemia T cell line Jurkat, acute lymphoblastic leukemia T cell line MOLT-4, lymphoblastic leukemia B cell line CCRF-SB) including myeloma (myeloma cell line HS-Sultan) dose-dependently and time-dependently to a degree equivalent or superior to that in myeloma, and induced apoptosis at a lower concentration as compared with YM175. We confirmed many dead cells as well as apoptosis based on the detection of the nuclei with separate globular structure, the activation of caspase-3, and the decrease in mitochondrial transmembrane potential. Therefore, it is concluded that further utilization of YM529 can be expected against hematopoietic tumor cells in the future.     

The behavior of dihydropyrazine with DNA strand-breakage activity in vivo

The effects on the viability of cell lines treated with 2,3-dihydro-5,6-dimethylpyrazine and its derivatives, which revealed DNA strand-breakage activity by the generation of radicals in vitro, were recognized from certain morphological changes and the detection of apoptosis-related proteins: cleaved PARP and SAPK/JNK. These results would suggest that sugar-derived dihydropyrazines induce changes in the cells of certain organs and cause various internal injuries in vivo. The biodistribution of 14C-labelled 2,3-dihydro-5,6-dimethylpyrazine was studied in mouse and the autoradiograms showed highly contrasting results. Radioactivity was high in the brain, spinal cord, salivary gland, and thymus and low in the heart, stomach, and blood. The result was supported by the activity (% dose per organ).     

Stress and vascular responses: endothelial dysfunction via lectin-like oxidized low-density lipoprotein receptor-1: close relationships with oxidative stress

Endothelial dysfunction is associated with pathological vascular conditions including atherosclerosis, hypertension, and diabetes. The oxidatively modified form of low-density lipoprotein (LDL) is recognized as a major cause of endothelial dysfunction in atherogenesis. As the receptor for oxidized LDL in endothelial cells, we have identified the lectin-like oxidized LDL receptor-1 (LOX-1). LOX-1 is up-regulated by products of oxidative stresses and the molecules that induce oxidative stresses. Activation of LOX-1 induces the generation of reactive oxygen species and decreases NO released from endothelial cells. LOX-1 activation further induces the expression of endothelin-1, AT(1) receptor, and cell adhesion molecules. Together with these properties, LOX-1 works as an adhesion molecule for activated platelets and neutrophils. Thus, LOX-1, within the close relationships between oxidative stress generation and response, enhances functional changes in endothelial cells that are relevant to the disturbed vascular homeostasis under pathological settings.     

Effects of perinatal exposure to bisphenol A on the behavior of offspring in F344 rats

The objective of this investigation is to evaluate whether perinatal maternal exposure to bisphenol A (BPA) at 4, 40, and 400 mg/kg per day affects the behavior of offspring in F344 rats. Perinatal BPA exposure inhibited the body weight increases of male and female offspring in a dose-dependent manner, which continued after weaning. Spontaneous activity analyses revealed that BPA elongated immobile time during the dark phase in female offspring. At 4 weeks of age, male offspring exposed to BPA at 40 and 400 mg/kg per day performed avoidance responses significantly higher in the shuttlebox avoidance test. At 8 weeks of age, however, male offspring only at 4 mg/kg per day showed significantly lower responses. In the open-field behavior test at 8 weeks of age, male offspring exposed to BPA only at 4 mg/kg per day showed a higher percent of grooming than the control male offspring. In conclusion, perinatal exposure to BPA caused the behavioral alterations in the offspring.     

Vitrectomy with internal limiting membrane peeling for macular retinoschisis and retinal detachment without macular hole in highly myopic eyes

PURPOSE: To report anatomic and visual improvement following vitrectomy with internal limiting membrane (ILM) peeling for two highly myopic patients with retinoschisis and/or retinal detachment without a macular hole. DESIGN: Two interventional case reports. METHODS: Two highly myopic patients who had retinoschisis and/or retinal detachment without a full-thickness macular hole underwent vitrectomy, internal limiting membrane peeling, and long-acting gas injection. Main outcome measures included best-corrected visual acuity, biomicroscopic appearance, and optical coherent tomography finding. RESULTS: Vitrectomy with ILM peeling results in biomicroscopic, functional, and tomographic improvement in both patients, for follow-up periods of 12 months and 8 months, respectively.CONCLUSIONS: Vitrectomy with ILM peeling and gas tamponade is an effective method for retinoschisis and/or retinal detachment without a macular hole in highly myopic patients.     

Herpes simplex keratitis after ophthalmic surgery

PURPOSE: We report 6 cases of herpes simplex keratitis after ophthalmic surgery, in eyes without clinical history of herpes simplex keratitis. CASES: These cases comprised 6 patients examined at our hospital between April 1992 and November 2001. Past operations were keratoplasty in 5 eyes and cataract surgery in 1 eye. Clinical findings and predisposing factors were evaluated retrospectively. The period between herpetic epithelial keratitis onset and ophthalmic surgery ranged from 1.5 to 79 months. Predisposing factors included corticosteroid therapy and operative wound. The herpetic epithelial lesions were dendritic ulcers in 2 eyes, geographic ulcer in 1 eye, and atypical epithelial lesions in 3 eyes; in all cases, herpes simplex virus (HSV)-DNA was detected by polymerase chain reaction (PCR) in tear fluid. All herpetic epithelial lesions healed with oral and topical acyclovir. CONCLUSIONS: When corticosteroids are used following ophthalmic surgery, physicians should be alert to the possibility of herpetic epithelial keratitis, even in patients with no clinical history of herpes simplex keratitis. PCR detection in tear fluid is helpful in diagnosing this disease.     

Macrophage depletion inhibits experimental choroidal neovascularization

OBJECTIVE: To investigate the role of macrophages in the development of laser-induced choroidal neovascularization (CNV) by selective depletion with liposomal clodronate (Cl(2)MDP-LIP). METHODS: Laser photocoagulation was used to induce CNV in wild-type C57BL/6J mice. Animals were treated with intravenous (IV) and/or subconjunctival (SC) Cl(2)MDP-LIP or PBS-LIP at the following time points: 2 days before, immediately after, 2 days before and immediately after, or 2 days after laser injury. CNV responses were compared on the basis of en masse volumetric measurements and fluorescein angiography after laser photocoagulation. Macrophages were identified by immunostaining for F4/80, and vascular endothelial growth factor (VEGF) expression was quantified by ELISA. RESULTS: Macrophages invaded the site of laser injury within 1 day of photocoagulation and peaked at 3 days. IV Cl(2)MDP-LIP significantly decreased the volume of CNV and angiographic leakage when administered 2 days before and/or immediately after laser injury, but not when administered 2 days after injury. SC Cl(2)MDP-LIP significantly decreased lesion volume when coadministered with IV PBS-LIP but not IV Cl(2)MDP-LIP. IV Cl(2)MDP-LIP was significantly more beneficial when administered 2 days before laser injury than immediately after, but combining SC Cl(2)MDP-LIP with IV treatment eliminated this difference. Reduction in CNV volume correlated with VEGF protein levels and number of infiltrating macrophages. CONCLUSIONS: Generalized macrophage depletion reduced the size and leakage of laser-induced CNV and was associated with decreased macrophage infiltration and VEGF protein. These findings define the role of the macrophage as a critical component in initiating the laser-induced CNV response.     

Scleral plug of biodegradable polymers containing tacrolimus (FK506) for experimental uveitis

PURPOSE: To evaluate the efficacy of a biodegradable polymeric scleral plug containing the immunosuppressive agent, FK506, in a rabbit model for experimental uveitis. METHODS: The scleral plugs were prepared by dissolving poly(DL-lactide-co-glycolide; PLGA) and FK506 (weight, 8.5 mg; length, 5 mm; 1% FK506). The release of FK506 was evaluated in vitro by spectrophotometry on days 1, 3, 7, 14, 21, and 35. In vivo, FK506 concentrations of the vitreous were measured by high performance liquid chromatography 2 and 4 weeks after intravitreous plug implantation in pigmented rabbits. Sixteen pigmented rabbits were immunized twice subcutaneously with 10 mg of Mycobacterium tuberculosis H37Ra antigen. Twelve days later, the right eyes of all rabbits were challenged with an intravitreal injection of 50 micro g of antigen. After the first challenge, the 16 eyes of 16 pigmented rabbits were divided into two groups. Scleral plugs were implanted into the vitreous of the right eye of eight rabbits. Eight control rabbits received a sham device. The aqueous protein concentrations and cell counts were determined on postchallenge days 7, 14, and 28. To simulated chronic inflammation, the eyes were rechallenged with intravitreal antigen on day 14 and were observed for 1 month. Inflammation of the anterior chamber and the vitreous were graded clinically by two masked observers. Retinal function was evaluated by electroretinography (ERG) and histologic examination. RESULTS: Clinical scores (anterior chamber cells, flare, and vitreous opacity) showed that treated eyes had significantly less inflammation than untreated eyes (P<0.001). Quantitative analysis of inflammatory cells (P<0.001) and protein concentrations (P<0.0001) in the anterior chamber showed significant decreases in treated eyes. Histopathologic examination showed marked inflammation and tissue disorganization in the untreated eyes. No retinal toxicity was detected, histopathologically and electroretinographically. After antigen rechallenge, inflammation in experimental eyes was still less than in control eyes. CONCLUSIONS: Intravitreal sustained-release of FK506 from a biodegradable polymeric scleral plug was highly effective in suppressing the inflammation of experimental uveitis in a rabbit model for at least 6 weeks. This device may be useful in the management of patients with severe chronic uveitis.     

Measuring of ocular wavefront aberration in large pupils using OPD-scan

Wavefront analysis using a scanning slit refractometer (the OPD-Scan) was evaluated in both artificial and human eyes, in comparison with the Hartmann-Shack wavefront sensor (H-S) currently often used. Comparison of different methods and configurations carried out in the artificial eyes yielded basically the same results in moderate refractive error cases. There was a closer match between the RMS (root mean square) wavefront error obtained by OPD-Scan and H-S in the 6 mm pupils than in the 4 mm pupils of the same normal human eyes. Although OPD-Scan employs a different approach in determining aberration, the aberration value is similar to that of H-S, especially in large pupils.