Efficacy of troxerutin on streptozotocin-induced rat model in the early stage of diabetic retinopathy.

The vascular changes associated with early diabetic retinopathy, which include the formation of microaneurysms and acellular capillaries, vessel dilation, vascular endothelial growth factor expression, were investigated experimentally in streptozotocin-induced diabetic rats treated with antioxidants: troxerutin (trihydroxy-ethylrutoside, CAS 7085-55-4), Vaccinium myrtillus, and calcium dobesilate (hydroquinone calcium sulfonate, CAS 20123-80-2). The development and progression of retinopathy was followed using fundus photography. After 3 months, the rats were sacrificed and half of the eyes were prepared for neovascularization analysis, and the other half were used for VEGF (vascular endothelial growth factor) analysis. The results from fundus photography and ADPase (adenosine diphosphatase) staining were quantified by the percentage area of the retinal vasculature using a commercial image analyzer. The VEGF protein in the retinal homogenates was assessed using an ELISA (enzyme linked immunosorbent assay) kit and VEGF-mRNA by RT-PCR (reverse transcription polymerase chain reaction). In the ADPase stain, the retinal vascular percent area increased significantly in the diabetic control. Neovascularization and aneurysms were observed in the diabetic control and were attenuated by 50 mg/kg troxerutin, but the retinal vascular percentage area was not significantly different from the diabetic control. The VEGF protein concentration was higher in diabetic rats than in the nondiabetic rats (21.5 +/- 2.1 vs 27.7 +/- 5.8 pg/mg, p < 0.05), and this increase was attenuated by 10 mg/kg troxerutin (24.5 +/- 3.8 pg/mg, p < 0.05) and prevented by 50 mg/kg troxerutin (19.5 +/- 2.2 pg/mg, p < 0.05). However, there were no significant differences between the groups. The VEGF-mRNA density showed a increasing tendency by 20% in the diabetic rats compared with the non-diabetic rats (1.0 +/- 0.1 vs 1.2 +/- 0.1 VEGF/beta-actin), and this increase was corrected by 10 mg/kg troxerutin (1.0 +/- 0.1 VEGF/beta-actin), 50 mg/kg troxerutin (0.9 +/- 0.1 VEGF/beta-actin) and Vaccinium myrtillus (1.1 +/- 0.1 VEGF/beta-actin). Oxidative stress might be involved in the upregulation of retinal VEGF during early diabetes, and it is likely that troxerutin has comparatively effective antioxidant properties. Therefore, troxerutin might be a useful treatment for attenuating diabetic retinopathy.

Spontaneous complex odontoma in a Sprague-Dawley rat.

Complex odontoma from a female Sprague-Dawley rat is described histopathologically. Necropsy revealed a hard (bony), white mass (3.0 x 3.0 x 2.1 cm) on the left mandible. Microscopically, the mass consisted of islands or nests of epithelial and mesenchymal elements that formed abortive tooth structures. In other areas, tooth formation consisted of a pulp cavity lined by layers of odontoblasts, dentin, enamel, and ameloblasts. Concerning all features of normal tooth formation which was differentiated and mineralized yet completely disorganized, the diagnosis of complex odontoma was recommended.

Herd-level seroprevalence of swine-influenza virus in Korea.

A total of 911 serum samples from 130 herds (an average of nine serum samples per herd) in Korea were examined for antibody to swine H1N1-influenza virus using enzyme-linked immunosorbent assay (ELISA). The list of farms was obtained from the Korean Swine Association, and herds were included from all five of the country's states. Farms were selected using a random-numbers table for swine within farms and for farms. All serum samples were collected from 22- to 24-week-old finishing pigs between September 2000 and March 2001. By ELISA, 93 out of 130 sampled herds (71.5%) were positive against swine H1N1-influenza virus. Our data suggested that seropositive herds for swine H1N1-influenza virus are distributed diffusely throughout the Republic of Korea.

Postweaning multisystemic wasting syndrome of pigs in Korea: prevalence, microscopic lesions and coexisting microorganisms.

A retrospective study was performed on natural cases of postweaning multisystemic wasting syndrome (PMWS), recorded from January 1999 to December 2000, to determine the prevalence, microscopic lesions, and other coexisting pathogens associated with PMWS. PMWS is diagnosed based on three criteria: the presence of clinical signs (retardation of growth), characteristic microscopic lesions (granulomatous inflammation and inclusion body), and the presence of porcine circovirus (PCV)-2 within these lesions. One hundred and thirty three (8.1%) of the 1634 pigs submitted from 1243 pig farms were diagnosed for PMWS. The affected pigs were from 25 to 120 days old, the majority (78 cases, 58.6%) being 60 to 80 days old. PMWS occurred each month during the two-year study period, but the incidence peaked in May (38 cases, 28.6%), followed by April (18 cases, 13.5%) and June (13 cases, 9.8%). The most consistent and characteristic lesions were multifocal, granulomatous inflammation in lymph nodes, liver and spleen, characterized by infiltration of epithelioid macrophages and multinucleated giant cells. The majority of cases (113 cases, 85.0%) was dual infection with other pathogens. The combination of PCV-2 and Hemophilus parasuis (43 cases, 32.3%) was shown to be the most prevalent followed by PCV-2 and porcine reproductive and respiratory syndrome virus (39 cases, 29.3%). The consistent presence of PCV-2, but lower prevalence of other viral and bacterial pathogens in all pigs examined with PMWS, has led to the speculation that PCV-2 is the etiological agent causing PMWS.

Antimicrobial susceptibility of pathogenic Escherichia coli isolated from pigs in Korea.

The in vitro susceptibilities of 285 isolates of Escherichia coli from preweaned and postweaned pigs with diarrhea and edema disease were tested with the 15 commonly used antimicrobial drugs by an agar dilution minimal inhibitory concentration procedure according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines. All E. coli isolates tested in this study belonged to enterotoxigenic E. coli, attaching and effacing E. coli, or Shiga toxin-producing E. coli. Field isolates had low MIC90 for ceftiofur (1 microg/ml). No correlation in antimicrobial resistance was found in three types of E. coli.

Detection and differentiation of North American and European genotypes of porcine reproductive and respiratory syndrome virus in formalin-fixed, paraffin-embedded tissues by multiplex reverse transcription-nested polymerase chain reaction.

North American and European genotypes of porcine reproductive and respiratory syndrome virus (PRRSV) were distinguished in formalin-fixed, paraffin-embedded tissues from PRRSV-infected pigs by multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR). A method based on xylene deparaffinization followed by proteinase K digestion yielded RNA of quality for reliable and consistent RT-nPCR analyses. The PRRSV nucleic acid was detected in lung, mediastinal lymph node, tonsil, and liver samples from pigs inoculated with North American strain virus, European strain virus, or both North American and European strains. All 30 archival formalin-fixed, paraffin-embedded lung tissues from pigs naturally infected with PRRSV were positive for PRRSV by RT-nPCR amplication and gave a pattern that corresponded to the North American genotype. Multiplex RT-nPCR could be applied successfully to formalin-fixed, paraffin-embedded tissues for the detection and differentiation between North American and European genotypes of PRRSV.