Development of spermatogenic function in the sex maturation process in male cats

The spermatogenic function and plasma testosterone (T) level in the sex maturation process were investigated as to 180 mixed breed cats ranging from 4 months to 2 years in age to be castrated. Testis/epididymis weights reached a peak at 10 and 8 to 9 months of age, respectively. In the testis, sperm appeared at 5 months of age. At 7 months of age, sperm were observed in 96.2% of the cats. In the tail of the epididymis, sperm appeared in 46.9% of the cats at 6 months of age and in all cats at 8 or more months of age. Furthermore, the mean plasma T level rapidly increased at 8 months of age, and reached a peak (2.64 +/- 0.68 (SE) ng/ml) at 10 months of age. Three of 180 cats (1.67%) had unilateral cryptorchidism. These results suggest that the spermatogenic function in male cats becomes mature at 8 to 10 months of age.     

Quillaja saponin can modulate ovalbumin-induced IgE allergic responses through regulation of Th1/Th2 balance in a murine model

Quillaja saponin is the extract from the balk of a South American tree, and it is considered to modulate immunological responses. We hypothesized that Quillaja saponin may change allergy-associated cytokine profile and antigen-specific immune responses. The purpose of this study is to investigate whether Quillaja saponin can suppress ovalbumin (OVA)-induced IgE-mediated allergic responses through promoting a dominant Th1 immune response. The spleen cells from BALB/c mice, which were primed by OVA, were used for an in vitro challenge test. The level of total and OVA-specific IgE, IL-4, IFN-gamma, and IL-12 was determined by enzyme-linked immunosorbent assay (ELISA). BALB/c mice were orally administered with saponin for 35 days. The mice were immunized intraperitoneally with OVA on days 14 and 21. After intraperitoneal challenge with OVA on day 35, anaphylactic symptoms were monitored. Total and specific IgE and IgG, specific IgG1 and IgG2a, and histamine levels in serum were analyzed by ELISA. The increase of IL-12 and IFN-gamma levels was observed in the presence of Quillaja saponin, while the IL-4 level was decreased. Furthermore, Quillaja saponin suppressed total and OVA-specific IgE secretion in spleen cells. Balb/c mice that were orally administered Quillaja saponin exhibited lower total and OVA-specific IgE and OVA-specific IgG secretions, whereas total IgG levels remained unchanged. Suppression of OVA-specific IgG1 and an increase of OVA-IgG2a were observed in mice fed saponin. Quillaja saponin also decreased serum histamine levels and diminished anaphylactic symptoms. The present study indicates that Quillajasaponin can suppress allergen-specific IgE-mediated reactivity in a murine model of food allergy, which results from shifting from a Th2-dominated to a Th1-dominated immune response.     

Effects of pressurization on structure, water distribution, and sensory attributes of cured ham: can pressurization reduce the crucial sodium content?

This study investigated the replacement of tumbling (intermittent vacuum tumbling for 6 h) with pressure treatment (7 MPa for 4 s) in the production of a cured ham product with the aim of elucidating if the pressure treatment could reduce the amount of salt added to obtain a satisfactory product. Confocal laser scanning microscopy (CLSM) revealed a pressure-induced loosening of the meat structure, and proton nuclear magnetic resonance (NMR) relaxometry revealed that this structural modification of the meat had an impact on water properties and water distribution in both cooked and cooked/fried products. Three salt levels (0.6, 1.1, and 1.7% w/w) were investigated, and sensory profiling revealed that the pressured-cooked meat obtained a significantly higher juiciness score at low and medium salt levels. In addition, sensory profiling assessments revealed that at the lowest salt concentration the pressured product was perceived to be saltier compared with the tumbled product; however, the difference was not significant and was absent upon frying. In contrast, in sensory time intensity analysis the maximum intensity and the total salt taste were significantly higher in the pressured samples at the low and medium salt levels in the cooked samples. In conclusion, the present study showed strong evidence that the structure and biophysical characteristics of cured ham is altered by pressurization and suggested that pressurization may reduce the critical amount of salt required in a ham product.     

Comparison of two different nutritive conditions against the changes in peripheral blood mononuclear cells of periparturient dairy cows

To clarify the relationship between cellular immune status and nutritive condition in periparturient dairy cows, feeding content, blood profiles, and immune condition were observed in cows from two dairy herds with different types of feed content. Immunological analyses such as leukocyte population and peripheral blood mononuclear cell (PBMC) mRNA of IFN-gamma, TNF-alpha, IL-4, and IL-10, quantified by real-time RT-PCR were performed. With regard to feed content during dry periods, there were six cows in the herd with insufficient non-structural carbohydrate (NFC) intake (group I) and six cows in the herd with sufficient NFC intake (group II). Significantly lower levels of blood glucose were observed in group I between weeks -12 and 16 compared with group II. Serum cholesterol level was significantly lower in group I between weeks 2 and 10 than in group II. The numbers of CD3+ and CD4+ T cells in group I were significantly lower than those in group II in weeks 6 and 14. The numbers of CD21+ B cells were significantly lower in group I than in group II in weeks -16, -12, 2, and 10. On the other hand, the CD4+/CD8+ ratio in group II was significantly higher than group I between weeks 2 and 14. The IFNgamma/IL-4 mRNA rate in group I was significantly lower than group II in week 6. We concluded that cellular immune depression occurrs after calving in dairy cows with low nutritional status in the periparturient period.     

The muscle protein Dok-7 is essential for neuromuscular synaptogenesis

The formation of the neuromuscular synapse requires muscle-specific receptor kinase (MuSK) to orchestrate postsynaptic differentiation, including the clustering of receptors for the neurotransmitter acetylcholine. Upon innervation, neural agrin activates MuSK to establish the postsynaptic apparatus, although agrin-independent formation of neuromuscular synapses can also occur experimentally in the absence of neurotransmission. Dok-7, a MuSK-interacting cytoplasmic protein, is essential for MuSK activation in cultured myotubes; in particular, the Dok-7 phosphotyrosine-binding domain and its target in MuSK are indispensable. Mice lacking Dok-7 formed neither acetylcholine receptor clusters nor neuromuscular synapses. Thus, Dok-7 is essential for neuromuscular synaptogenesis through its interaction with MuSK.     

Development of EST-SSR markers of Ipomoea nil

Although Japanese morning glory (Ipomoea nil (L.) Roth.) has been used intensively for genetic studies, DNA markers have not been developed in Ipomoea nil sufficient to cover all chromosomes. Therefore, we conducted microsatellite (simple sequence repeats, SSR) marker development in I. nil for future genetic studies. From 92,662 expressed sequence tag (EST) sequences, 514 unique microsatellite-containing ESTs were identified. Primer pairs were designed automatically in 326 SSRs. Of 150 SSRs examined, 75 showed polymorphisms among strains. A phenogram based on the SSR genotypes revealed the genetic relation among seven Japanese morning glories from five different regions of the world and an ivyleaf morning glory (I. hederacea Jacq.). The developed SSR markers might be applicable for genetic studies of morning glories and their relatives.     

Estimation of glomerular filtration rate in calves using the contrast medium iodixanol

To develop a simple procedure for estimating glomerular filtration rate (GFR) in calves, a three-sample method using iodixanol was first compared to that using the standard agent inulin. Iodixanol and inulin were co-administered intravenously to calves at 40 mg I/kg and 40 mg/kg, respectively, and blood was collected 30, 60, 120, and 180 min later. Serum iodixanol and inulin concentrations were separately determined by high performance liquid chromatography and colorimetry. Serum urea nitrogen (UN) and creatinine concentrations were also measured. GFR estimated by iodixanol was consistent with that using inulin in clinically healthy calves. Based on GFR estimations in healthy calves and those renal-loaded with iodixanol, it was found that the serum creatinine concentrations became elevated when GFR decreased to 60% of the reference value. In contrast, serum UN concentrations fluctuated widely, presumably due to extra-renal factors. When GFR was estimated using the three-sample method and compared with the single-blood-sample method, 62/69 (90%) of samples tested were within the agreement plots. The results demonstrated that the single-blood-sample method using iodixanol may be useful in monitoring GFR in calves.     

Effects of brine salting with regard to raw material variation of Atlantic salmon (Salmo salar) muscle investigated by Fourier transform infrared microspectroscopy

Atlantic salmon fillets differing with regard to raw material characteristics (prerigor, postrigor, frozen/thawed) and salt content were investigated by FT-IR microspectroscopy and light microscopy. Local variation within each salmon fillet was further taken into account by sampling from the head and tail part separately as they vary in fat and moisture content. The highest salt uptake was achieved for frozen/thawed quality during brine-salting with 16% NaCl for 4 h, while the uptake was least for prerigor fish. At the same time, salting caused muscle fiber swelling of about 10% for both frozen/thawed and postrigor qualities. Differences in the FT-IR amide I spectral region were observed implying a change in the muscle protein secondary structure. Prerigor was least affected by brine-salting, having a final salt concentration of 2.2%, while postrigor had a NaCl content of 3.0% and frozen/thawed of 4.1%. Local variation within the fillets had an effect on the amide I absorption characteristics before as well as after salting. Salt uptake of the samples was affected by raw material quality and at the same time the degree of swelling of the myofibers was influenced by raw material character.