Attenuation by all-trans-retinoic acid of sodium chloride-enhanced gastric carcinogenesis induced by N-methyl-N′-nitro-N-nitrosoguanidine in Wistar rats

The effect of prolonged administration of all-trans-retinoic acid (RA) on sodium chloride-enhanced gastric carcinogenesis induced by N-methyl-N′-nitro-N-nitrosoguanidine, and the labelling and apoptotic indices and immunoreactivity of transforming growth factor (TGF) α in the gastric cancers was investigated in Wistar rats. After 25 weeks of carcinogen treatment, the rats were given chow pellets containing 10% sodium chloride and subcutaneous injections of RA at doses of 0.75 or 1.5 mg kg−1 body weight every other day. In week 52, oral supplementation with sodium chloride significantly increased the incidence of gastric cancers compared with the untreated controls. Long-term administration of RA at both doses significantly reduced the incidence of gastric cancers, which was enhanced by oral administration of sodium chloride. RA at both doses significantly decreased the labelling index and TGF-α immunoreactivity of gastric cancers, which were enhanced by administration of sodium chloride, and significantly increased the apoptotic index of cancers, which was lowered by administration of sodium chloride. These findings suggest that RA attenuates gastric carcinogenesis, enhanced by sodium chloride, by increasing apoptosis, decreasing DNA synthesis, and reducing TGF-α expression in gastric cancers. © 1999 Cancer Research Campaig

Using virtual reality in criminological research

Since the pioneering early studies of the 1990s hinted at its promise as a research method, virtual reality (VR) technology has increasingly been used by social scientists. Given recent developments that have greatly enhanced realism, reduced costs, and increased possibilities for application, VR seems well on its way to become an established research tool in the social sciences. However, as with other ethodological innovations, the field of criminology hasbeen slow to catch on. To address this gap, this article explores the potential of VR as a tool for crime research. It provides readers with a brief and non-technical description of VR and its main elements and reviews severalapplications of VR in social scientific research that are potentially relevant for criminologists. By way of illustration, we identify and discuss in more detail different areas in which we think the field of criminology can particularly benefit from VR and offer suggestions for research. Some of the equipment available on the consumer market is also reviewed.In conjunction, the different sections should equip readers interested in applying VR in their own research with a fundamental understanding of what it entails and how it can be applied

Measurement of serum and vitreous concentrations of anti-type II collagen antibody in diabetic retinopathy

Atsuko Nakaizumi,1 Masanori Fukumoto,1 Teruyo Kida,1 Hiroyuki Suzuki,1 Seita Morishita,1 Takaki Satou,1 Hidehiro Oku,1 Tsunehiko Ikeda,1 Kimitoshi Nakamura2 1Department of Ophthalmology, Osaka Medical College, Takatsuki City, Osaka, 2Nakamura Eye Clinic, Nagano, Japan Background: Autoimmune mechanisms have been postulated as a cause of diabetic retinopathy (DR), as several autoantibodies have reportedly been detected in the serum of DR patients. In this present study, we measured serum and vitreous levels of anti-type II collagen (anti-II-C) antibodies in DR patients and investigated their association with the mechanism of development of DR.Patients and methods: Blood samples were obtained from patients with proliferative DR and from patients with diabetic macular edema who underwent vitrectomy at Osaka Medical College, Takatsuki City, Osaka, Japan. Diabetic patients without DR were also included. The control group consisted of age- and sex-matched patients with noninflammatory eye diseases who underwent eye surgery for retinal detachment or for cataracts. The levels of anti-II-C immunoglobulin (Ig)G antibody in the vitreous and serum were measured using a human/monkey anti-II-C IgG assay kit.Results: The serum levels of anti-II-C IgG antibody were significantly higher in the DR patients than in the patients with noninflammatory eye disease (56.8±33.8 units/mL versus 30.5±13.7 units/mL, respectively; P<0.05, Fisher’s exact test). These levels were also significantly higher in the diabetic patients without DR than in the patients with noninflammatory eye disease (76.3±49.7 units/mL versus 30.5±13.7 units/mL, respectively; P<0.01, Fisher’s exact test). However, anti-II-C IgG antibody levels were unable to be detected in all of the obtained vitreous fluid samples.Conclusion: The development and progression of DR may be related to a mechanism involving intraocular type II collagen, which normally has immunological tolerance as a sequestered antigen. In DR, the disruption of the blood–retinal barrier leads to contact between the intraocular type II collagen and immunocompetent cells, and to subsequent activation of the autoimmune mechanism. Keywords: blood–retinal barrier, autoimmune mechanism, vitreous, seru