Inhibition of biofilm bacteria and adherent fungi from marine plankton cultures using an antimicrobial combination

The presence of organic matter in plankton cultures will lead to 10- to 1000-fold increases in bacterial density in less than 24 h. The presence of bacteria and fungi can damage cultivated phytoplankton and zooplankton. These microorganisms can also inhibit experiments investigating the role of these microorganisms in the community and in biological and ecological laboratory studies. The aim of this study was thus to evaluate the effect of penicillin?+?streptomycin?+?neomycin (antibiotics) in combination with nystatin (antifungal) to select an antimicrobial combination for the inhibition of biofilm bacteria and adherent fungi that is effective and also non-toxic to marine phytoplankton and zooplankton. Acartia tonsa was exposed to different antimicrobial treatments and application routes (culture medium, culture food, both) to evaluate the survival and egg and fecal pellet production endpoints. The same treatments were also applied to measure Amphibalanus improvisus survival and settlement and Conticribra weissflogii growth endpoints. We selected the most sensitive experimental organism and exposed it to some novel antimicrobial combinations. To evaluate the inhibition potential, biofilm bacteria and adherent fungi were exposed to the treatments that were safe for the bioindicator species. A tonsa was considered the most sensitive of all tested organisms. The treatment composed of 0.025 g L^?1 penicillin G potassium?+?0.08 g L^?1 streptomycin sulfate?+?0.04 g L^?1 neomycin sulfate showed the best results for A. tonsa and C. weissflogii cultures. No differences were observed for A. improvisus between the treatments. A. tonsa survival rates showed no differences from the control at nystatin concentrations up to 0.005 g L^?1 in combination with the antibiotics. The biofilm bacterial density decreased up to 94% under this treatment, and fungal growth was prevented. Species of other planktonic groups should also be tested to improve our understanding of the effectiveness of the treatments proposed.

     

Antioxidative activities of fractions obtained from brewed coffee

The antioxidative activity of column chromatographic fractions obtained from brewed coffee was investigated to find antioxidants and to assess the benefit of coffee drinking. The dichloromethane extract inhibited hexanal oxidation by 100 and 50% for 15 days and 30 days, respectively, at the level of 5 microg/mL. A GC/MS analysis of fractions, which exhibited oxidative activity, revealed the presence of antioxidative heterocyclic compounds including furans, pyrroles, and maltol. The residual aqueous solution exhibited slight antioxidative activity. The inhibitory activity (%) of the seven fractions from an aqueous solution toward malonaldehde formation from lipid oxidation ranged from 10 to 90 at a level of 300 microg/mL. The results indicate that brewed coffee contains many antioxidants and consumption of antioxidant-rich brewed coffee may inhibit diseases caused by oxidative damages.     

Antioxidative activities of heterocyclic compounds formed in brewed coffee

Typical volatile heterocyclic compounds found in brewed coffee extracts-pyrroles, furans, thiophenes, and thiazoles-were examined for antioxidative activity, which was determined by measuring the oxidative conversion of hexanal to hexanoic acid using gas chromatography. 2-Acetylpyrrole, 1-methylpyrrole, and pyrrole inhibited hexanal oxidation by 98, 87, and 78%, respectively, at a concentration of 500 microgram/mL over a period of 30 days. 2-Methylfuran, which inhibited hexanal oxidation by 90% at all concentrations tested (500, 200, and 100 microgram/mL) for a 30-day period, exhibited the greatest activity among furans tested. Similarly, 2-methylthiophene, which inhibited hexanal oxidation by almost 100% at a concentration of 500 microgram/mL over 30 days, exhibited the greatest activity among the thiophenes tested. In general, thiazoles were ineffective antioxidants at all concentrations tested. However, 4,5-dimethylthiazole was able to inhibit hexanal oxidation by 50% at the highest level tested (500 microgram/mL). 2-Acetylpyrrole, 2-methylfuran, and 2-methylthiophene at concentrations of 500, 200, and 100 microgram/mL and furan at a concentration of 500 microgram/mL exhibited antioxidative activities comparable to that of the synthetic antioxidant butylated hydroxytoluene at a concentration of 50 microgram/mL.     

The possible role of the tibial plateau angle for the severity of osteoarthritis in dogs with cranial cruciate ligament rupture

The purpose of this study was to determine factors correlated with the severity of radiographic osteoarthritis (OA) scoring in dogs with cranial cruciate ligament rupture (CrCLR). Three radiographs of stifle joints (craniocaudal, mediolateral, and mediolateral radiograph with 90 degree flexion of the stifle and tarsal joints) were obtained from 36 dogs with CrCLR (Clinical group) and from 22 dogs without stifle joint disease (Control group). Information about these dogs was collected from the owners and from medical records. Radiographic OA scores in each dog in the clinical group were determined from radiographs using a numeric grading system previously reported. The tibial plateau angle (TPA) in each dog in both groups was measured on mediolateral radiographs with 90 degree flexion of the stifle and tarsal joints. The Mann-Whitney's U test was used for comparing variables between the clinical group and the control group, and Spearman's rank correlation test was used for evaluating correlations between radiographic OA scores and variables in the clinical group. No significant differences were detected between the clinical group and the control group for any of the variables. There were two positive correlations; one between the radiographic OA score and TPA (r=0.395, p=0.014); and the other between body weight and OA score (r=0.399, p=0.013) in the clinical group. Our results indicate that body weight and TPA could affect the severity of the radiographic OA score in dogs with CrCLR.     

Effect of protein malnutrition on the skin epidermis of hairless mice

The purpose of this study was to evaluate the effect of protein malnutrition on the skin epidermis of mice. A low protein diet induced thinning of the skin epidermis, a decrease of cell proliferative activity in epidermal cells and a decrease of stratum corneum hydration. Dityrosine was immunostained in the cytoplasm of epidermal cells in the low protein diet group. Plasma advanced oxidation protein product (AOPP) levels were significantly more increased in the low protein diet group than in the control diet group. These results suggest that protein malnutrition adversely affects the structure and water barrier and reservoir functions of the skin epidermis, and these pathological changes are associated with the expressions of protein oxidation markers, dityrosine and AOPP.     

A retrospective study of intervertebral disc herniation in dogs in Japan: 297 cases

We investigated the epidemiological characteristics of intervertebral disc herniation (IVDH) in Japan in a large population using a retrospective study. The sample population was dogs (n=297) with IVDH in Japan. Medical records were reviewed for breed, sex, age, affected interspace and neurological severity. The dogs were comprised of 132 cases of cervical IVDH (C-IVDH) and 165 cases of thoracolumbar IVDH (TL-IVDH). In Japan, the Dachshund, Beagle and Shih Tzu tended to suffer from both C-IVDH and TL-IVDH. The Shiba Inu, a characteristic Japanese dog breed, suffered from both C-IVDH and TL-IVDH, although there was little data relating to the whole breed. Male dogs tended to suffer from C-IVDH and TL-IVDH at a rate almost twice that of females in Japan. Among the three predominant dog breeds, the Dachshund, Beagle and Shih Tzu, the Dachshund tended to suffer from both C-IVDH and TL-IVDH at an earlier age than the Beagle, and the Beagle tended to suffer from both C-IVDH and TL-IVDH earlier than the Shih Tzu. Among the three predominant breeds, the Shih Tzu, in particular, tended to suffer from both C-IVDH and TL-IVDH at multiple sites. Our data from Japan were in partial agreement with previous data from the U.S.A., and epidemiological characteristics of IVDH peculiar to Japan were also identified.     

Evaluation of feeding value of forage soybean silage as a substitute for wheat bran in sheep

Twelve sheep were used in a 3 × 3 Latin square design to evaluate the effect of substituting wheat bran with forage soybean silage in the diet on apparent digestibility and nitrogen balance. Forage soybean (Glycine max (L.) Merrill) was cultivated in a no‐till, no‐herbicide cropping system with Italian ryegrass (Lolium multiflorum Lam.) as a living mulch. Forage soybean and Italian ryegrass were wilted and ensiled in round bales without additives, respectively. The experimental diets were based on corn silage supplemented with protein sources (tow silages or wheat bran). The crude protein and the acid detergent insoluble protein contents of forage soybean silage were the highest among the protein sources. The apparent digestibility of crude protein and the nitrogen balance did not significantly differ among the diets. In addition, the phytoestrogen content of forage soybean silage was below the level at which animal reproductive performance would be negatively affected. These results suggest that forage soybean silage has comparable feeding value to wheat bran, and can be given at an inclusion level of 17% (dry matter basis) as an alternative protein source to wheat bran without adverse effects on digestion or nitrogen balance in sheep fed a corn silage‐based diet.     

Expressions of lipid oxidation markers, N(ε)-hexanoyl lysine and acrolein in cisplatin-induced nephrotoxicity in rats

The purpose of this study was to evaluate whether N(ε)-hexanoyl lysine (N(ε)-HEL) and acrolein reflect the severity of cisplatin-induced nephrotoxicity. Immunoexpression of N(ε)-HEL and acrolein in kidneys and their urinary concentration were examined up to day 4 post-cisplatin injection in rats. Cisplatin-induced tubular injury was observed histopathologically on days 2-4 after injection and became more severe time-dependently. On days 2-4, N(ε)-HEL and acrolein were immunostained in the cytoplasm of damaged tubular cells. Their immunostaining intensity and urinary levels increased as tubular injury became more severe. These results suggest that expressions of N(ε)-HEL and acrolein were associated with the pathogenesis of cisplatin-induced nephrotoxicity.     

Expressions of protein oxidation markers, dityrosine and advanced oxidation protein products in acetaminophen-induced liver injury in rats

The purpose of this study was to evaluate whether dityrosine and advanced oxidation protein products (AOPP) were useful as biomarkers for monitoring the development of acetaminophen-induced liver injury. Dityrosine immunoexpression in the liver along with plasma AOPP concentration was examined up to 24 hr post-acetaminophen injection in rats. The histopathological changes in the liver appeared 3 hr after acetaminophen injection and became exacerbated with time. The immunohistological expression of dityrosine was also first detected in the damaged hepatocytes 3 hr after the injection and became more accentuated at 6, 12 and 24 hr in accompanying with the elevation of plasma AOPP concentration. These results suggested that dityrosine and AOPP expressions might be useful biomarkers for monitoring the development of acetaminophen-induced liver injury.     

Complete nucleotide sequence of the cytochrome b gene of channel catfish Ictalurus punctatus and comparison of sequence homology among channel catfish and other fishes

To clarify the phylogenic relationship of channel catfish with other fishes, the cytochrome b (Cyt b) gene of the catfish was cloned and sequenced. Channel catfish (Ictalurus punctatus) belonging to the family Ictaluridae in the order Siluriformes showed a 78.4-87.4% similarity to all but one fish of the family Cyprinidae and river loach Crossostoma lacustre of the family Balitoridae in the order Cypriniformes in which genes had already been sequenced, and a 97.2% similarity to the goldfish (Carassius auratus) belonging to the family Cyprinidae. Within the family Cyprinidae, a 78.8-89.2% similarity to one another was recorded. In addition, the similarity rate between the family Cyprinidae and the family Balitoridae reached a value of 77.8-79.9% in the order Cypriniformes. Furthermore, in an unrooted phylogenetic tree consisting of four branches among eight fishes, channel catfish and goldfish appeared in the same branch. These results suggested that the Cyt b gene of the channel catfish in the order Siluriformes was closely related to that of a goldfish in the order Cypriniformes. The results were not agreement with the morphological classification. Genetic reclassification of the fishes may be necessary to identify the ancestor. This is the first report on the cloning and complete sequencing the Cyt b gene of the channel catfish which may contribute to the genetic reclassification of catfishes belonging to the order Siluriformes.