Ocular Toxicity of Benzalkonium Chloride Homologs Compared with Their Mixtures

This study was performed to assess the in vivo ocular toxicity of benzalkonium chloride (BAK) homologs compared with commercially available BAK (BAK mixture) and to assess the ocular toxicity of BAK homolog after repeated ocular application. Rabbit eyes were examined by ophthalmology and scanning electron microscopy (SEM) after 10 applications of BAK homologs with C12 (C12-BAK) and C14 (C14-BAK) alkyl chain lengths and a BAK mixture at concentrations of 0.001% (w/v), 0.003% (w/v), 0.005% (w/v), 0.01% (w/v) and 0.03% (w/v). The ocular toxicity of C12-BAK to rabbit eyes was examined by ophthalmology and histopathology after repeated ocular application for 39 weeks. In addition, the antimicrobial activities of C12-BAK and C14-BAK against A. niger, S. aureus and P. aeruginosa were assessed. Ocular toxicity of C12-BAK was less than those of the BAK mixture and C14-BAK. No ocular toxicity was noted after ocular application of 0.01% C12-BAK to rabbits for 39 weeks. C12-BAK showed antimicrobial activities at a concentration of 0.003%. These results suggest that the use of C12-BAK to replace BAK mixture as a preservative in ophthalmic solutions should be considered in order to reduce the incidence of the corneal epithelial cell injury induced clinically by BAK.     

PCR–RFLP identifies differences in hrpZ sequences to distinguish two genetic groups of Pseudomonas syringae pv. syringae strains from barley and wheat with bacterial black nod

Differences in hrpZ sequences determined by polymerase chain reaction (PCR)–restriction fragment length polymorphism (RFLP) were used to investigate the molecular epidemiology of Pseudomonas syringae pv. syringae (PSS) strains that were isolated from diseased barley and wheat plants in Okayama, Japan. PCR–RFLP using HhaI separated PSS strains into two groups (A and B). Although specific PCR–RFLP groups of PSS strains were not always isolated from specific cultivars or seeds produced in a specific area, many strains isolated from barley and wheat belonged to PCR–RFLP groups A and B, respectively.     

Differential characteristics of microfold cells on the dome epithelium of porcine ileum

The monospecific antibody directed against cytokeratin 18 consistently immunostained microfold cells (M‐cells) in the ileum epithelium of pigs. In adult pigs, M‐cells were numerously distributed in the dome epithelium overlying Peyer's patches, especially in the crypt epithelium to the lower dome epithelium. The M‐cells presented in the crypt epithelium were mostly columnar in shape and showed a gradual transition from columnar cells to pocket‐like cells as they drew near the lower dome epithelium. In contrast, the M‐cells that were sporadically located in the villus epithelium were all columnar and similar to enterocytes in shape. In newborn pigs, a few M‐cells were observed only in the infant dome epithelium, which were all columnar resembling the enterocytes. Of the 19 lectins used, the dome epithelial cells were selectively stained by lectins from Ulex europaeus‐I and Anguuilla anguilla. Especially, the M‐cells were stained by lectin from Anguuilla anguilla although the intensity varied on individual pigs. Lymphoid follicles in the lamina propria were well developed in the adults compared to these in the newborns, and lymphoid cells were more populated in the lower part than the upper part of the dome. The present results provide available information to understand the differentiation and functional heterogeneity of porcine M‐cells.     

Differentiation of Fusobacterium necrophorum subspecies from bovine pathological lesions by RAPD-PCR

Nineteen strains from bovine abscesses identified as Fusobacterium necrophorum by the VPI method were examined by other methods. The API 20A test kit characterized all 19 strains as F. necrophorum. Seven of the strains had haemagglutinating activity and were classified as F. necrophorum subspecies necrophorum, and the remaining, 12 nonhaemagglutinating strains, were classified as F. necrophorum subspecies funduliforme. We used RAPD-PCR with a 10-mer oligonucleotide primer, W1L-2, to confirm this differentiation of the two subspecies. These results suggest that random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) with a suitable primer can be used as a new tool for the differentiation of F. necrophorum subspecies isolated from bovine pathological lesions.     

Studies of waste tea garden soils (Part 1)1)

I. Introduction

In Uji district, Kyoto Pref., the most famous place of tea production in Japan, tea gardens, particularly the refined tea (Gyokuro and Matsucha) gardens, have been producing very low yields. Their features are poor, dotted with withered plants. Such tea gardens are named the waste tea gardens. ōsugi²⁾ and Yoshie³⁾ had made research on these phenomena since 1930 and ascribed them to some defects of soil properties.     

Mechanical and chemical constituents of water-stable aggregates of paddy soil with relationship to the aggregate size

Introduction

In previous papers¹,², a method for determining the water-stable aggregate in paddy soils has been reported. This method is based on the slaking disruption of air dried clod of soil in an excess of water. The aggregates thus obtained are truly stable in water and also stable against a gentle agitation in wet sieving operation. It is very interesting to study the cementing materials which stabilize the aggregates.     

On the complex formation between soil humus and polyvalent cations

In 1946 BREMNER et al.(1) suggested a theory that, in soils, polyvalent metals are combined with organic matter as metal-organic matter complexes, and that these complexes are insoluble in solvents that do not themselves form complexes with metals. The principle of one of the most prevailing methods for humus extraction, the neutral sodium pyrophosphate extraction proposed by BREMNER and LEES (2), is a corollary of the theory.     

Neutralizing antibodies against feline parvoviruses in nondomestic felids inoculated with commercial inactivated polyvalent vaccines

The virus neutralization (VN) antibody titers of serum samples from 18 individuals representing 8 carnivore species vaccinated with commercial polyvalent vaccines optimized for domestic cats containing inactivated feline panleukopenia virus (FPLV) were evaluated against canine parvovirus type 2 (CPV2). In addition, the titers among 5 individuals from 4 carnivore were evaluated against antigenic variants of feline parvoviruses; FPLV, CPV2, CPV2a, CPV2b, CPV2c, mink enteritis virus type 1 (MEV1) and MEV2. The polyvalent vaccines induced cross-reactive VN titers against antigenic variants of feline parvoviruses in nondomestic felids. However, we observed very low cross-reactive VN antibody in lions and Siberian tigers, therefore we should pay attention to CPV infections in these animals even if they were vaccinated with inactivated FPLV vaccines.     

Carrier-state infection of feline T-lymphoblastoid cells with feline calicivirus

The susceptibility of feline T lymphocytes to feline calicivirus (FCV) in vitro was investigated using feline T-lymphoblastoid cell lines, namely MYA-1 and FL74 cells. The virus titers of supernatants in FCV-infected MYA-1 and FL74 cell cultures increased rapidly, and FCV antigens were also detected in the FCV-infected cells. There were slight differences in the molecular weights of capsid proteins expressed in FCV-infected MYA-1, FL74 and Crandell feline kidney cells. MYA-1 and FL74 cells were productively and persistently infected with FCV, and FCV antigens were observed in the FCV-infected cells for more than one month. At 3 months post infection, FCV-infected FL74 cells that stopped producing infectious FCV could be reinfected with FCV. However, no cytopathic effects were observed.     

Molecular typing of Japanese strains of Ralstonia solanacearum in relation to the ability to induce a hypersensitive reaction in tobacco

The genetic diversity of 120 Ralstonia solanacearum strains isolated from a variety of host plants across Japan was assessed on the basis of hypersensitive response (HR) in tobacco leaves and phylogenetic analyses of endoglucanase gene egl, hrpB, and gyrB. Phylogenetic analysis of egl revealed that only three strains belonged to phylotype IV, and 117 strains belonged to phylotype I. Partial sequences of HrpB were identical among phylotype I strains except for one strain. Analyses using the partial nucleotide sequences of the gyrB and egl gene fragments grouped phylotype I strains into 11 gyrB and 8 egl types, respectively, whereas analyses using the partial amino acid sequences of GyrB and Egl grouped phylotype I strains into 4 GyrB and 5 Egl types, respectively. Using multilocus sequence typing of GyrB and Egl, we identified 10 unique sequence types within the Japanese phylotype I strains. Strains belonging to the GyrB42 or GyrB66 type caused wilt in tobacco, and strains belonging to GyrB2 or GyrB9 type elicited HR, demonstrating that HR induction in tobacco is genetically differentiated in the Japanese strains of R. solanacearum.