Selective modulation of P-glycoprotein activity by steroidal saponines from Paris polyphylla

Bio-guided fractionation of the roots of Paris polyphylla (Trilliaceae), based on inhibition of P-glycoprotein-mediated daunorubicin efflux in K562/R7 cell line, led to isolation and identification of the three saponins 3-O-Rha(1-->2)[Ara(1-->4)]Glc-pennogenine, gracillin and polyphyllin D, and the two ecdysteroids 20-hydroxyecdysone and pinnatasterone. These compounds were tested for multidrug reversion on P-glycoprotein (ABCB1) with both drug-selected and transfected cell lines, and also on Breast Cancer Resistance Protein (BCRP/ABCG2). By contrast to a weak efficiency on BCRP, the three saponins displayed significant effects as inhibitors of P-glycoprotein-mediated drug efflux.     

Effects of dietary fat and energy on body weight and composition after gonadectomy in cats

OBJECTIVE: To evaluate the effect of dietary fat and energy density on body weight gain, body composition, and total energy expenditure (TEE) in neutered and sexually intact cats. ANIMALS: 12 male and 12 female cats PROCEDURE: Male cats were castrated (castrated male [CM]) or underwent no surgical procedure (sexually intact male [IM]). Female cats underwent ovariectomy (spayed female [SF]) or laparotomy and ligation of both uterine tubes without ovary removal (sexually intact female [IF]). Cats were fed either the low-fat (LF) or high-fat (HF) diet for 26 weeks, with the final allocation consisting of 8 groups: IF-LF IF-HE SF-LF, SF-HF IM-LF, IM-HF, CM-LF, and CM-HF. Mean food intake for each group was recorded daily, and body weight was monitored weekly throughout the study. Body composition and TEE were measured before surgery in week 0 and at the end of the study (week 26) by isotope dilution (double-labelled water). RESULTS: N eutered cats gained significantly more body fat and body weight (53.80+/-5.79%) than sexually intact cats (27.11+/-5.79%) during the study. Body weight gain of neutered cats fed the HF diet was greater than those fed the LF diet. Following correction for body composition, TEE was similar in all groups and no pattern towards increased food intake was evident. CONCLUSIONS AND CLINICAL RELEVANCE: Weight gain in neutered cats was decreased by feeding an LF, low energy-dense diet. To prevent weight gain in cats after neutering, a suitable LF diet should be fed in carefully controlled meals rather than ad libitum.     

Production of offspring from one-day-old oocytes stored at room temperature

To determine the feasibility of preserving oocytes without freezing, we stored mouse oocytes in several media at different temperatures for one day. Confocal microscopy of the metaphase-II spindle in these stored oocytes revealed gross abnormalities in both the spindle and the arrangement of chromosomes. The abnormal spindles could not be rescued by transplanting the aged spindle-chromosome complex into a fresh enucleated oocyte. A diploid parthenogenetic development showed that some of the oocytes stored at room temperature could still develop into blastocysts (10-57%). However, oocytes stored in a refrigerator (5%) or incubator (0%) lost the potential almost entirely. Fertilization of room-temperature-preserved oocytes with fresh spermatozoa by ICSI or IVF resulted in, respectively, 4 and 10%, full-term births. These results suggest that when oocytes are stored at room temperature for one day, most have irreversible damage not only to their cytoplasm but also to the spindle. However, since at least a few percent of stored oocytes retained the potential for full-term development, it may be possible to overcome these problems and develop a simple method for preserving mammalian oocytes without freezing.     

Influence of dietary linseed, fish and coconut oil on growth performance of growing pigs kept on small holdings in central Vietnam

The aim of the study was to investigate the effect on growth performance of the addition of 5% of either linseed, fish or coconut oil to the diet of growing pigs kept on small holdings in central Vietnam. The diets were fed on six different farms; there were three animals per treatment per farm. The farmers fed a base diet according to personal choice, but were instructed to use linseed, fish and coconut oil. The diets were fed to the pigs from 70 to 130 days of age. The diets with 5% linseed oil on average contained 2.4 g alpha-linolenic acid/MJ of metabolizable energy (ME) and the diets with 5% fish oil on average contained 0.06 and 0.75 g eicosapentaenoic and docosahexaenoic acid/MJ ME, respectively. The relative percentages of docosahexaenoic, eicosapentaenoic, alpha-linolenic and linoleic acid in adipose tissue were determined by the intake of the corresponding fatty acids. Dietary linseed oil vs. coconut oil significantly enhanced daily weight gain and vs. fish oil it also stimulated growth, but this effect just failed to reach statistical significance. It is concluded that extra intake of alpha-linolenic acid may stimulate growth in growing-finishing pigs, this effect being independent of the conversion of alpha-linolenic acid into eicosapentaenoic and docosahexaenoic acid.     

Suppurative rhinitis associated with Haemophilus species infection in a cat

A young cat with signs of chronic rhinitis was evaluated for underlying anatomical, inflammatory, or infectious disease. Initial diagnostics were significant for the isolation of an unusual pathogen, Haemophilus species. Isolation using a human RapID NH system erroneously identified the isolate as H. segnis, a human pathogen. No database of veterinary pathogens (Haemophilus) are included in the system and animal pathogens will either be erroneously identified or yield a unique biocode not listed. Because of the unique nature of the pathogen we explored the possibility of immunosuppression as a contributory factor to infection. A variety of laboratory tests were employed to evaluate immune function. The clinical indications and utility of immune function testing are discussed. No immune dysfunction was identified.     

A novel in vitro hydroponic culture system for potato (Solanum tuberosum L.) microtuber production

An innovative in vitro hydroponic culture system used in potato (Solanum tuberosum L.) microtuber production is described in this paper. In vitro potato plantlets, 6–8 cm in height, derived from meristems of potato tubers cultured on 1/2 Murashige and Skoog (MS) nutrient medium after 30 days culture were cut into 1.5 cm stem node segments and used as explants. These stem nodes were cultured in a novel system called in vitro hydroponic culture system containing 1/2 MS medium supplemented with 0.5 μM naphthaleneacetic acid (NAA), 0.3 μM gibberellic acid (GA₃), 3.7 μM adenine sulfate, 10% coconut water, 0.5 g/l activated charcoal, 80 g/l sucrose with or without 8 g l⁻¹ agar. Liquid medium was distributed to the carrier substrates in each storey of the system with the aid of capillary robes. In the present paper, the effects of porous material used as substrate carrier and the number of storeys involved in the culture system on microtuber formation and their morphological characteristics are reported. Cotton layer substrate is more stable for organogenesis of potato microtubers. Microtubers, 3.19 mm in diameter and 49.82 mg in weight, could be harvested from a one-storey in vitro hydroponic culture system containing filter paper as substrate. However, microtubers cropped from three-storey in vitro hydroponic culture system with cotton layer were bigger and weightier than those from three-storey system containing filter paper. The above results of the in vitro hydroponic system examined in this study might open up a new approach in producing potato and other hygrophilous microtuber.     

Transmissible gastroenteritis (TGE) of swine: in vitro virus attachment and effects of polyanions and polycations

Four transmissible gastroenteritis virus (TGEV) strains (Purdue-115, D-52, 188-SG and Gep-II) and two cell lines (swine testis-ST and pig kidney-RPD) were used to study virus attachment and cell susceptibility. Virus attachment was partially thermodependent and the rate varied, depending on the strain. Identical TGEV inocula produced a higher plaque number by plaque assay in the swine testis cell line (ST) than in the pig kidney cell line (RPD) but [3H]uridine-labelled virus was found associated equally well with both cell lines. A field TGEV strain (Gep-II), which was unable to multiply in cell cultures, appeared able to inhibit the attachment of radiolabelled cell-passaged virus. Therefore, the susceptibility to TGEV infection was apparently not determined at the virus-to-cell attachment stage. The attachment sites on the cell surface were specific, however, differences in TGEV attachment determinant between strains were not observed. Attachment of all the virus strains tested was enhanced by DEAE-dextran and inhibited by dextran sulfate, poly-L-lysine (PLL), poly-L-alpha-ornithine (PLO) and protamine sulfate.