Effects of coat length and faecal hair removal on measured nutrient digestibility in cats.

OBJECTIVES: This experiment was conducted to evaluate the effect of coat length and faecal hair removal on measured nutrient digestibility in longhair and shorthair cats. METHODS: A total of 14 adult domestic cats, with a mean ± SD body weight of 4.5 ± 1.21 kg and a mean ± SD age of 3.3 ± 1.38 years, were used for a nutrient digestibility trial. The nutrient digestibility of cats was measured by hair-included faeces and hair-removed faeces. Food was provided twice daily (09:00 h and 16:00 h) and water was provided ad libitum. Cats were adapted to a steel cage and diet for 16 days before a 10 day collection period. During the collection period, food offered, food refused and faecal output were measured daily and used for digestibility analysis. RESULTS: The digestibility of dry matter, crude protein and neutral detergent fibre (NDF) of longhair cats was underestimated by 8% ( P = 0.02), 9% ( P = 0.04) and 14% ( P = 0.04), respectively. In shorthair cats, the digestibility of dry matter, crude protein and crude ash increased by 4% ( P = 0.01), 5% ( P = 0.02) and 15% ( P <0.01), respectively, with hair-removed faeces. The nutrient digestibility between longhair and shorthair cats showed no difference when hair-included faeces were used. However, when using hair-removed faeces, the digestibility of NDF and amino acids in longhair cats were about 4-8% higher than in shorthair cats ( P <0.05). CONCLUSIONS AND RELEVANCE: This study showed that the nutrient digestibility values were affected by whether the hair in faeces was removed or not. Removing hair from faeces is a more precise method with which to evaluate the apparent nutrient digestibility of domestic cats.

Evaluation of grooming behaviour and apparent digestibility method in cats.

OBJECTIVES: This experiment was conducted to evaluate the behavioural time budget for grooming and grooming patterns for shorthair and longhair cats, and to assess the effect of grooming behaviour on apparent digestibility of nutrients in domestic cats ( Felis catus) by comparing hair-included faeces and hair-removed faeces. METHODS: A total of 10 adult domestic cats, with a mean ± SD body weight of 4.3 ± 0.89 kg and a mean ± SD age of 3.5 ± 1.38 years, were used for behavioural observation. Cats were housed individually in stainless steel cages at the animal hospital. The cats' behaviour was recorded on a webcam videotaping system for one 24 h period; then, faecal samples were collected and analysed to measure apparent digestibility. RESULTS: There was no significant difference between longhair and shorthair cats in behavioural time budget for grooming and grooming patterns. The apparent digestibility of dry matter, crude protein, crude ash, acid detergent fibre (ADF) and neutral detergent fibre (NDF) of hair-removed faeces was significantly higher than that of hair-included faeces: about 6% ( P <0.01), 7% ( P <0.01), 14% ( P <0.01), 12% ( P = 0.01) and 10% ( P <0.01), respectively. CONCLUSIONS AND RELEVANCE: There was no difference in grooming patterns between longhair cats and shorthair cats. Also, the digestibility of dry matter, crude protein, crude ash, ADF and NDF has been underestimated by approximately 6%, 7%, 14%, 12%, and 10%, respectively, when they have been calculated using the conventional digestibility method for domestic cats.

Increased nicotinamide adenine dinucleotide pool promotes colon cancer progression by suppressing reactive oxygen species level.

Nicotinamide adenine dinucleotide (NAD) exists in an oxidized form (NAD+ ) and a reduced form (NADH). NAD+ plays crucial roles in cancer metabolism, including in cellular signaling, energy production and redox regulation. However, it remains unclear whether NAD(H) pool size (NAD+ and NADH) could be used as biomarker for colon cancer progression. Here, we showed that the NAD(H) pool size and NAD+ /NADH ratio both increased during colorectal cancer (CRC) progression due to activation of the NAD+ salvage pathway mediated by nicotinamide phosphoribosyltransferase (NAMPT). The NAMPT expression was upregulated in adenoma and adenocarcinoma tissues from CRC patients. The NADH fluorescence intensity measured by two-photon excitation fluorescence (TPEF) microscopy was consistently increased in CRC cell lines, azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CRC tissues and tumor tissues from CRC patients. The increases in the NAD(H) pool inhibited the accumulation of excessive reactive oxygen species (ROS) levels and FK866, a specific inhibitor of NAMPT, treatment decreased the CRC nodule size by increasing ROS levels in AOM/DSS mice. Collectively, our results suggest that NAMPT-mediated upregulation of the NAD(H) pool protects cancer cells against detrimental oxidative stress and that detecting NADH fluorescence by TPEF microscopy could be a potential method for monitoring CRC progression.

Detection of Sleeping Beauty transposition in the genome of host cells by non-radioactive Southern blot analysis.

The Sleeping Beauty transposon (SB-Tn) system is being used widely as a DNA vector for the delivery of therapeutic transgenes, as well as a tool for the insertional mutagenesis in animal models. In order to accurately assess the insertional potential and properties related to the integration of SB it is essential to determine the copy number of SB-Tn in the host genome. Recently developed SB100X transposase has demonstrated an integration rate that was much higher than the original SB10 and that of other versions of hyperactive SB transposases, such as HSB3 or HSB17. In this study, we have constructed a series of SB vectors carrying either a DsRed or a human ß-globin transgene that was encompassed by cHS4 insulator elements, and containing the SB100X transposase gene outside the SB-Tn unit within the same vector in cis configuration. These SB-Tn constructs were introduced into the K-562 erythroid cell line, and their presence in the genomes of host cells was analyzed by Southern blot analysis using non-radioactive probes. Many copies of SB-Tn insertions were detected in host cells regardless of transgene sequences or the presence of cHS4 insulator elements. Interestingly, the size difference of 2.4 kb between insulated SB and non-insulated controls did not reflect the proportional difference in copy numbers of inserted SB-Tns. We then attempted methylation-sensitive Southern blots to assess the potential influence of cHS4 insulator elements on the epigenetic modification of SB-Tn. Our results indicated that SB100X was able to integrate at multiple sites with the number of SB-Tn copies larger than 6 kb in size. In addition, the non-radioactive Southern blot protocols developed here will be useful to detect integrated SB-Tn copies in any mammalian cell type.

Observation of red-shifted strong surface plasmon scattering in single Cu nanowires.

Surface plasmon scattering spectra of chemically produced single Cu nanowires were obtained using a total internal reflection microscope. In particular, we have observed a strong surface plasmon peak in the far red and a red-shift of the surface plasmon resonance with increasing nanowire diameter. We believe that the most reasonable origin for the red-shift of comparably large diameter nanowires is the phase retardation effect.

Synthesis of dendrimer-based biotin radiopharmaceuticals to enhance whole-body clearance.

To synthesize a biotin radiopharmaceutical that clears rapidly, dendrimer was used as a carrier and conjugated with succinimidyl 3-[(125)I]iodobenzoate and tetrafluorophenyl norbiotinamidosuccinate. Then, succinic anhydride was used to reduce its pI. In mice, the non-succinylated product showed high liver (67% ID/g) and kidney (44% ID/g) uptakes and whole-body retention (94% ID) at 20 min that persisted for 12 hr. The corresponding organ uptakes (22% and 11% ID/g) and the whole-body retention (47% ID) were drastically reduced by succinylation (p<0.0001). Lysine co-injection further lowered renal uptake.

Radioimmunotherapy of A431 xenografted mice with pretargeted B3 antibody-streptavidin and (90)Y-labeled 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA)-biotin.

We investigated the biodistribution of (88)Y/(111)In-labeled 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA)-biotin and therapy with (90)Y-labeled DOTA-biotin in tumor-bearing mice after B3-streptavidin antibody conjugate (B3-SA) pretargeting. B3 antibody, recognizing Lewis(y) antigen, was conjugated to streptavidin (B3-SA). For pretargeting, 400 micro g of the B3-SA was injected i.v. into mice bearing A431 tumor xenografts. After tumor localization of B3-SA, 100 micro g of synthetic clearing agent was injected i.v. to clear the unbound B3-SA from the circulation. Four h later, 1 micro g of radiolabeled DOTA-biotin was injected i.v. Radioimmunotherapy was performed with doses of 9.25 to 37 MBq of (90)Y-labeled DOTA-biotin. As a result, radiolabeled DOTA-biotin cleared rapidly. All of the normal tissues had <2.6% of the injected dose per gram, whereas tumor uptake reached approximately 15% ID/g. The total tumor uptake of radioactivity remained similar for 96 h or longer. In the first study, the median survival of the control group was 8 days, whereas it increased to >163 days in the 37 MBq (90)Y group (P < 0.005). In a second therapy group, 7 of 10 mice receiving 37 MBq of (90)Y and B3-SA were cured, and remained healthy for >180 days after therapy, compared with control groups, with