Changes in the physiochemical, microbial, and sensory characteristics of fresh pork sausage containing rosemary and green tea extracts during retail display.

The effects of adding combinations of rosemary (R: 1500, 2000, 2500 ppm) and green tea (G: 100, 200, 300 ppm) extracts in combination with synthetic antioxidants on the physiochemical, microbial, and sensory characteristics of fresh pork sausage were evaluated. R and G improved (P < .05) oxidative stability as evidenced by lower TBARS. R2500 and G300 had fewer PPC than the control at d 7, 14, and 21 of storage. Consumer acceptability scores were greater (P < .05) in sausages with R and G when compared to the control, and the majority of the R and G treatments were liked by 98% of the respondents. Treatment combinations of at least R2000 and G200 were described by positive drivers of liking such as spice-complex, ginger, nutmeg, rosemary flavors and aromas and lower scores for descriptors such as rancid, fruity, and off-flavor/odor. This research demonstrates that rosemary and green tea extracts improved the keeping quality of fresh pork sausage under simulated retail display.

Impact of High-Level Daptomycin Resistance in the Streptococcus mitis Group on Virulence and Survivability during Daptomycin Treatment in Experimental Infective Endocarditis.

Among the viridans group streptococci, the Streptococcus mitis group is the most common cause of infective endocarditis. These bacteria have a propensity to be ß-lactam resistant, as well as to rapidly develop high-level and durable resistance to daptomycin (DAP). We compared a parental, daptomycin-susceptible (DAPs) S. mitis/S. oralis strain and its daptomycin-resistant (DAPr) variant in a model of experimental endocarditis in terms of (i) their relative fitness in multiple target organs in this model (vegetations, kidneys, spleen) when animals were challenged individually and in a coinfection strategy and (ii) their survivability during therapy with daptomycin-gentamicin (an in vitro combination synergistic against the parental strain). The DAPr variant was initially isolated from the cardiac vegetations of animals with experimental endocarditis caused by the parental DAPs strain following treatment with daptomycin. The parental strain and the DAPr variant were comparably virulent when animals were individually challenged. In contrast, in the coinfection model without daptomycin therapy, at both the 106- and 107-CFU/ml challenge inocula, the parental strain outcompeted the DAPr variant in all target organs, especially the kidneys and spleen. When the animals in the coinfection model of endocarditis were treated with DAP-gentamicin, the DAPs strain was completely eliminated, while the DAPr variant persisted in all target tissues. These data underscore that the acquisition of DAPr in S. mitis/S. oralis does come at an intrinsic fitness cost, although this resistance phenotype is completely protective against therapy with a potentially synergistic DAP regimen.

Molecular cloning and expression pattern of oriental river prawn (Macrobrachium nipponense) nitric oxide synthase.

Nitric oxide synthase (NOS) produces nitric oxide (NO) by catalyzing the conversion of l-arginine to l-citrulline, with the concomitant oxidation of nicotinamide adenine dinucleotide phosphate. Recently, various studies have verified the importance of NOS invertebrates and invertebrates. However, the NOS gene family in the oriental river prawn Macrobrachium nipponense is poorly understood. In this study, we cloned the full-length NOS complementary DNA from M. nipponense (MnNOS) and characterized its expression pattern in different tissues and at different developmental stages. Real-time quantitative polymerase chain reaction (RT-qPCR) showed the MnNOS gene to be expressed in all investigated tissues, with the highest levels observed in the androgenic gland (P < 0.05). Our results revealed that the MnNOS gene may play a key role in M. nipponense male sexual differentiation. Moreover, RT-qPCR revealed that MnNOS mRNA expression was significantly increased in post-larvae 10 days after metamorphosis (P < 0.05). The expression of this gene in various tissues indicates that it may perform versatile biological functions in M. nipponense.

Fibre type-dependent response of broiler muscles to dietary antioxidant supplementation for oxidative stability enhancement.

The influence of dietary antioxidants and quality of oil on the oxidative and physico-chemical properties of chicken broiler breast and thigh meat stored was studied in either an oxygen-enriched (HiOx: 80% O2/20% CO2) or an air-permeable polyvinylchloride (PVC) packaging system during retail display at 2-4°C for up to 14 and 7 d, respectively. Broilers were fed on a diet with either a low-oxidised (peroxide value (POV) 23 meq O2/kg) or a high-oxidised (POV 121 meq O2/kg) oil, supplemented with or without an algae/selenium-based antioxidant with organic minerals, for 42 d. Lipid and protein oxidation, myofibrillar protein profile and purge loss were analysed. In both packaging systems, lipid oxidation (thiobarbituric acid-reactive substances [TBARS]) was inhibited by up to 65% and 57% in chicken breast and thigh, respectively, with an antioxidant-supplemented diet compared to those without. In both breast and thigh samples, protein sulfhydryls and water-holding capacity (purge loss) were better protected by the antioxidant dietary treatment, regardless of oil quality. Thigh muscles had up to sevenfold greater TBARS formation and more myosin heavy chain losses compared to breast samples. Antioxidant supplementation was more protective against lipid oxidation and water-holding capacity in the group fed on high-oxidised oil compared to those fed on low-oxidised oil. The results suggest that dietary antioxidants can minimise the negative impact of oxidised oil on broiler meat quality, and this protection was more pronounced for thigh than breast muscle, indicating inherent variations between muscle fibre types.

Gene expressions and metabolomic research on the effects of polyphenols from the involucres of Castanea mollissima Blume on heat-stressed broilers chicks.

To study the effects of polyphenolic extract from involucres of Castanea mollissima Blume ( PICB: ), a novel approach using gene expression by real time polymerase chain reaction ( REAL-TIME PCR: ) coupled with metabolomic profiling technique was established to explain the mechanism of PICB on heat-stressed broiler chicks. Four thousand 28-day-old male Arbor Acres (AA) broilers were randomly assigned to 5 groups (4 replicates / group, 20 chicks / replicate), in which group 1 was normal control group fed with basic ration; groups 2, 3, 4, and 5 were fed with the basic ration with a supplementation of 0.2% Vitamin C ( VC: ), or 0.2%, 0.3%, or 0.4% of PICB respectively. After 1 wk of adaptation, heat stress was applied for 7 consecutive days. On d 3 and d 7 of heat stress, the chicks were sacrificed and sampled. The mRNA expression of heat stress protein 70 (HSP70), glutathione peroxidase ( GSH-PX: ), ornithine decarboxylase ( ODC: ), epidermal growth factor ( EGF: ) and epidermal growth factor receptor ( EGFR: ) were detected by real-time PCR using samples from jejunum mucosa. The serum and jejunum mucosa metabolomic profiles of PICB group showing best antioxidative effects and control group at d 3 were studied using the method of the gas chromatography - time of flight mass spectrometry ( GT-TOF-MS: ), followed by principal component analysis and partial least squares-discriminate analysis. Potential biomarkers were found using Student's t-test. The results showed mRNA expressions of HSP70, GSH-Px, ODC, EGF, and EGFR were altered by the supplementation of PICB. PICB exhibited antioxidative and growth promoting effects, and 0.3% PICB supplementation level exhibited the best. Three metabolites in the serum and 5 in the jejunum mucosa were identified as potential biomarkers. They were considered to be in accordance with antioxidative and growth promoting effects of PICB, which involved in the energy metabolism (sorbitol, palmitic acid), carbohydrate metabolism, amino acids metabolism (serine, L-ornithine), glutathione metabolism (glutamate, L-ornithine), GnRH signaling pathway (inositol), etc. These findings provided novel insights into our understanding of molecular mechanism of PICB effects on heat-stressed chicks.

Protective effect of Bu-Zhong-Yi-Qi decoction, the water extract of Chinese traditional herbal medicine, on 5-fluorouracil-induced intestinal mucositis in mice.

Intestinal mucositis is a serious toxic side effect of 5-fluorouracil (5-FU) treatment. Bu-Zhong-Yi-Qi decoction (BZYQD), a water extract of Chinese traditional herbal medicine, is widely used in chemotherapy in Asia as an alternative treatment to reduce the side effects of chemotherapy. However, the mechanism is unknown. To evaluate its mechanism, we investigated the effect of BZYQD on 5-FU-induced intestinal mucositis in mice, especially with regard to apoptosis in the intestinal mucosal epithelia. In the present study, mice were divided into three groups: control, 5-FU, and 5-FU + BZYQD. Mice in the 5-FU and 5-FU + BZYQD groups were administered 5-FU (100 mg/kg/day, intraperitoneally) for 6 days, and the mice in the latter group were given BZYQD (8 g/kg/day, intragastrically) beginning 4 days before 5-FU and continuing until the termination of the experiment. Loss in body weight and diarrhea during the 5-FU treatment were significantly attenuated by administration of BZYQD. The morphological signs of intestinal damage, including shortened villi height, crypt destruction, apoptosis, and necrosis, in intestinal mucosal epithelia were also reversed, accompanied by reduced neutrophil infiltration, nitrite levels, and inflammatory factors (tumor necrosis factor α and interleukin 1ß) and increased levels of reduced glutathione. These results suggest that BZYQD inhibits 5-FU-induced intestinal mucositis, and this effect may be due to the reduction in apoptosis and necrosis in intestinal mucosal epithelia via the suppression of inflammatory cytokine upregulation. In conclusion, inhibiting cytokine-mediated apoptosis or necrosis can be the molecular mechanism by which BZYQD reduces the gastrointestinal side effects of cancer chemotherapy.

Molecular cloning, characterization, and expression analysis of a Broad-Complex homolog during development in the oriental river prawn Macrobrachium nipponense.

Broad-Complex (BR-C) is an early ecdysone-responsive gene encoding a family of zinc-finger transcription factors. In this study, we isolated the full-length cDNA of a BR-C homolog from the testes of the oriental river prawn (Macrobrachium nipponense), according to established expressed sequence tag information, using the rapid amplification of cDNA ends technique. The homolog was designated as MnBR-C. The full-length cDNA of MnBR-C contained a 1095-bp open reading frame encoding a precursor protein of 365 amino acid residues. Comparative and bioinformatic analyses revealed that MnBR-C exhibited a high degree of homology with BR-C proteins, and contained the BTB and Zf-H2C2-2 domains. Real-time quantitative polymerase chain reaction (qPCR) analysis revealed that the MnBR-C expression level varied significantly in the developing embryo, postembryonic larva, and adult tissue. Real-time qPCR showed that the MnBR-C gene was expressed in all of the tissues investigated, with the highest level of expression in the brain. In addition, MnBR-C was more abundantly expressed in the testes than in the ovaries.

Augmentation of water-holding and textural properties of breast meat from oxidatively stressed broilers by dietary antioxidant regimens.

1. The impact of dietary antioxidants and degree of oil oxidation on textural attributes of chicken broiler breast meat stored in oxygen-enriched, air-permeable polyvinylchloride and skin packaging systems during retail display at 2-4°C for up to 21 d was assessed. 2. Broilers were fed on diets either with a low-oxidised oil (peroxide 23 mEq O2/kg) or with a high-oxidised oil (peroxide 121 mEq O2/kg), with or without an algae-based antioxidant and organic mineral antioxidant supplement for 42 d. 3. Fatty acids and radical scavenging activities of the diets were estimated. Meat colour, pH, myofibrillar protein profile and textural traits were measured. 4. Diets with high-oxidised oil reduced stearic, linoleic and linolenic acid content compared to low-oxidised oil samples, regardless of antioxidant supplementation. Meat colour and pH varied among dietary treatments throughout storage. Meat samples from the antioxidant dietary group, irrespective of oil oxidation level, had lower amounts of purge and cooking losses compared to the unsupplemented diets. For all packaging systems, meat shear force was significantly higher for broilers fed on high-oxidised diets. 5. The results demonstrate that dietary antioxidant supplementation can minimise the negative impact of oxidised oil on the quality of broiler meat packaged in different atmospheric environments.

Antioxidative activity of the polyphenols from the involucres of Castanea mollissima Blume and their mitigating effects on heat stress.

Polyphenols extracted from plants have multiple functions in animal production. To explore new sources of tannin-rich extracts, which have potential benefits for animal health, this study focused on the effects of polyphenolic extracts from involucres of Castanea mollissima Blume (PICB) on heat-stressed broilers. In vitro experiments were first performed using intestinal cryptlike epithelial cell line-6 (IEC-6) cells to evaluate the effects of PICB on cell proliferation and antioxidative parameters under normal and heat-stress conditions. Then in vivo experiments were carried out with 2 trials: in trial 1, 400 one-d-old male Arbor Acres (AA) broilers were randomly assigned to 5 groups (4 replicates/group, 20 chicks/replicate): group 1 was a normal control group fed the basic ration; groups 2 to 5 were fed the basic ration supplemented with 0.2% vitamin C and 0.2%, 0.3%, and 0.4% PICB, respectively. Trial 1 lasted 42 d, and growth performance was monitored every week. At the end of the trial, the chicks were sacrificed and sampled. In trial 2, 400 twenty-eight-d-old chicks were randomly assigned to 5 groups as described in trial 1. After 1 week of adaptation, heat stress was applied for 7 consecutive days. On days 3 and 7 of heat stress, the chicks were sacrificed and sampled. The results showed that PICB could stimulate IEC-6 cell proliferation and had strong in vitro antioxidant activity. PICB had no effect on the growth performance and carcass parameters of AA broilers in trial 1, whereas in trial 2, group 4 saw improved growth performance and antioxidant activity compared to the first three groups (P < 0.05). In conclusion, PICB had no effects on the growth performance of IEC-6 cells and AA broilers under normal conditions, whereas it could mitigate heat-stress effects on the growth performance and antioxidant activity of IEC-6 cells and AA broilers, implying that PICB could be used as a suitable additive to improve animal production under heat-stress conditions.

Combination therapy with iron chelation and vancomycin in treating murine staphylococcemia.

Iron acquisition is a virulence factor for Staphylococcus aureus. We assessed the efficacy of the iron chelator, deferasirox (Def), alone or in combination with vancomycin (Van) against two methicillin-resistant S. aureus (MRSA) strains in vitro and in a murine bacteremia model. In vitro time-kill assays were carried out against MRSA or vancomycin-intermediate S. aureus (VISA) strains. The impact of Def on Van binding to the surface of S. aureus was measured by flow cytometry. Furthermore, we compared the efficacy of Def, Van, or both drugs in treating S. aureus bacteremia in a murine model. Combination therapy reduced MRSA and VISA viability in vitro versus either drug alone or untreated controls (p < 0.005); this outcome was correlated with enhanced Van surface binding to S. aureus cells. In vivo, Def + Van combination therapy significantly reduced the bacterial burden in mice kidneys (p = 0.005) and spleen (p < 0.001), and reduced the severity of infection with MRSA or VISA strains compared to placebo-treated mice. Our results show that Def enhances the in vitro and in vivo capacity of Van-mediated MRSA killing via a mechanism that appears to involve increased binding of Van to the staphylococcal surface. Iron chelation is a promising, novel adjunctive therapeutic strategy for MRSA and VISA infections.

Textural and viscoelastic properties of pork frankfurters containing canola-olive oils, rice bran, and walnut.

Textural, rheological and microstructural properties of frankfurters made with 20% pork backfat, 20% canola or 20% canola-olive (3:1) oils, including rice bran (RB) and walnut extract (WE) as macronutrients (2.5%) were investigated. Textural parameters, including hardness, gumminess and rupture-force, were highly (P<0.05) influenced by the fat-oil composition. Addition of RB or WE in vegetable oil emulsions improved textural consistency (P<0.05). However, RB addition reduced gelling capacity, suggesting antagonistic interactions between fiber and oil droplets. Vegetable oil addition favored gel network formation, and, when combined with WE, showed the highest improvement of gel elasticity. These textural and gelling properties were corroborated by frankfurter micrographs, which revealed interactions between vegetable oils, RB, or WE with protein matrix and fat globules affecting these parameters. The results suggest that functional plant-derived ingredients can be valuable to the modification of frankfurter formulations for improved nutrition and as well as textural quality.

First Report of Tobacco curly shoot virus Infecting Pepper in China.

In recent years, whitefly-transmitted begomovirues (family Geminiviridae) have caused severe leaf curl disease on tobacco and tomato in southern China, but have not been found on pepper. In August 2009, pepper plants (Capsicum frutescens) grown in the field in Panzhihua City of Sichuan Province (southwestern China), from where the occurrence of begomoviruses has not been reported previously, showed stunting, leaf yellowing, and mild curling symptoms. To identify possible begomoviruses, total DNA was extracted from three infected pepper plants (SC117, SC118, and SC119) with typical symptoms. Using degenerate primer pair PA/PB specific for members of the genus Begomovirus (2), a 500-bp DNA fragment covering parts of the intergenic region and V2 gene of the genome of begomoviruses was amplified from all samples. No amplification was observed from healthy plant extracts. The PCR product from SC118 was cloned and two clones were chosen to be sequenced. Alignment of the partial DNA sequences revealed that the cloned products from isolate SC118 were nearly identical (98.5%) and most closely related to Tobacco curly shoot virus isolate Y35 (TbCSV-[China:Yunnan 35:2001]; Accession No. AJ420318) (96.9 and 97.3% identity, respectively). Therefore, the entire genome of isolate SC118 was sequenced. Overlap primers TbCSV-F(5'-CCGCCGTCTCAACTTCGACAG-3') and TbCSV-R(5'-ATCTGCTGGTCGCTTCGACAT-3') were designed to amplify the full-length genome of SC118. The complete genome sequence of SC118 was determined to be 2,746 nucleotides (Accession No. GU001879) long, with two open reading frames (ORFs) in the virion-sense strand and four ORFs in the complementary-sense strand, typical of the Old World begomoviruses. A comparison with other reported sequences of begomoviruses shows that the genome of SC118 shares the highest nucleotide sequence identity (99.7%) with TbCSV-[China:Yunnan 35:2001]. When PCR was used to detect TbCSV from the other two isolates (SC117 and SC119) with TbCSV specific primer pair Y35F1 and Y35+10R (4), which amplified the fragment covering the whole C2 and C3 genes and the partial C1 and V1 genes of the genome of TbCSV, an amplicon of approximately 1.0 kb was obtained from all samples. To determine whether a satellite molecule was associated with the three virus isolates, a universal betasatellite abutting primer pair (beta01 and beta02) was used (1). No amplification product was detected. In previous studies, it was demonstrated that only 11 isolates were associated with betasatellites among 39 TbCSV-infected, field-collected samples (3), and betasatellites could be associated with noncognate begomoviruses (4). Therefore, the three isolates examined in this study are too few to come to a conclusion that betasatellites are not associated with TbCSV infection of pepper plants. A detailed search for the presence of betasatellites needs to be conducted to draw a definitive conclusion. The above results confirmed that samples SC117, SC118, and SC119 were infected by TbCSV. To our knowledge, this is the first report of TbCSV on pepper in China. References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:317, 2002. (2) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (3) Z. Li et al. Phytopathology 95:902, 2005. (4) L. Qing et al. Phytopathology 99:716, 2009.

Inhibition of oxidant-induced biochemical changes of pork myofibrillar protein by hydrolyzed potato protein.

The objective of the study was to investigate the role of hydrolyzed potato protein (HPP) in protecting myofibril protein isolate (MPI) from oxidative modification. MPI prepared from pork muscle was suspended (30 mg protein/mL) in 15 mM piperazine-N, N-bis(2-ethane sulfonic acid) buffer (pH 6.0) with 0, 0.3, 0.75, and 1.5 mg/mL of antioxidative HPP (1-h Alcalase hydrolysate). Oxidation was induced by incubating the protein suspensions at 4 degrees C for 24 h with (1) an iron-catalyzed oxidizing system (IOS: 0.01 mM FeCl3, 0.1 mM ascorbic acid, and 1.0 mM H202) and (2) a metmyoglobin-oxidizing system (MOS: 0.1 mM metmyoglobin and 0.1 mM H2O2). Changes in oxidized MPI were measured as thiobarbituric acid-reactive substances (TBARS), protein carbonylcontent, Ca- and K-ATPase activities, and ultraviolet (UV) spectra. Oxidation increased the production of TBARS and protein carbonyls by 2.9- and 0.24-fold in IOS and 5.6- and 2.2-fold in MOS, respectively. The 2 oxidizing systems altered the Ca- and K-ATPase activities and exposed hydrophobic groups buried in MPI. The presence of HPP reduced the extent of MPI oxidation in all physicochemical categories tested. Therefore, HPP may be used as a potential functional ingredient in meat products to enhance their oxidative stability.

Identification of a differential gene HUMMLC2B between F1 hybrids Landrace x Yorkshire and their female parents Yorkshire.

In order to investigate heterosis on a molecular basis, suppression subtractive hybridization was used to analyze the differences in gene expression between porcine F1 hybrids Landrace x Yorkshire and their female parents Yorkshire. From two specific subtractive cDNA libraries, the clones screened out by reverse Northern high-density blots screening were chosen to clone full-length cDNA by RACE. An expression-upregulated gene for Yorkshire skeletal muscle, designated as HUMMLC2B, was identified. Porcine HUMMLC2B contains an open reading frame (ORF) encoding 169 amino acids residues with 59 and 115 nucleotides in the 5' and 3' untranslated regions (UTRs), respectively. In the porcine genome, it contains seven exons separated by six introns. High allelic variations and four SINEs were detected in it. Comparison of derived amino acid sequence of HUMMLC2B with database sequences revealed highly conserved 12 amino acid residues in a putative calcium-binding region. RT-PCR analysis showed a tissue-specific pattern of expression in skeletal muscle and a similar level of expression during skeletal muscle development. The possible role of HUMMLC2B and its relation to porcine heterosis are discussed.

Effect of ligustrazine on ischemia-reperfusion injury in murine kidney.

INTRODUCTION: Ischemia-reperfusion (I/R) injury is unavoidable in cadaveric renal transplantation. It contributes to acute rejection and chronic allograft dysfunction. Studies have shown that Ligustrazine, a purified and chemically identified component of a Chinese herbal remedy, is a potent blocker of vasoconstriction and has strong effects to scavenge oxygen free radicals. Since warm I/R is potentially more damaging than cold storage, we investigated the possible protective effect of Ligustrazine on warm I/R in mice. METHODS: Unilaterally nephrectomized C57BL/6 male mice were subjected to 50 minutes of left renal ischemia. Group I were sham-operated animals; group II, nontreated animals (saline, iP 30 minutes before I/R); and group III, Ligustrazine-treated animals (80 mg/kg, iP 30 minutes before I/R). Mice were sacrificed 24 hours postreperfusion. Serum creatinine, blood urea nitrogen, kidney malondialdehyde (MDA)level, and superoxide dismutase (SOD) were determined as well as examining the kidneys histologically with immunohistochemistry for Bcl-2, and ICAM-1. RESULTS: I/R produced a six fold increase in creatinine and urea nitrogen levels in group II. Ligustrazine halved the increase, as well as attenuated the necrosis and apoptosis in the tubules (P < .01). Ligustrazine decreased MDA levels and ameliorated the down-regulation of SOD activity. Bcl-2 was up-regulated following I/R, especially in the Ligustrazine-treated group (P < .01). The up-regulation of ICAM-1 was greatly diminished by Ligustrazine (P < .01). CONCLUSION: These findings suggest that Ligustrazine reduces the renal dysfunction associated with warm I/R of the kidney.

cDNA cloning, genomic structure and polymorphism of the porcine FHL3 gene.

LIM domain proteins are important regulators of the growth, determination and differentiation of cells. Four-and-a-half LIM-only protein 3 (FHL3) is a type of LIM-only protein that contains four tandemly repeated LIM motifs with an N-terminal single zinc finger (half LIM motif). In this study, we have determined the complete coding sequence of pig FHL3 which encodes a 280 amino acid protein. The coding region of the pig FHL3 gene is organized in five exons and spans an approximately 2.1-kb genomic region. Comparative sequencing of six pig breeds revealed three single nucleotide polymorphisms (SNPs) within exon 2 of which an A-->G substitution at position 313 changes a codon for arginine into a codon for glycine. The substitution was situated within a PstI recognition site and developed as a PCR-RFLP marker for further use in population variation investigations and association analysis. The A/G polymorphism was segregating only in Landrace pigs. Association studies of the FHL3 polymorphism with carcass traits provided preliminary evidence that the PstI PCR-restriction fragment length polymorphism (RFLP) genotype may be associated with variation in several carcass traits of interest for pig breeding. Further investigations in more Landrace pigs are needed to confirm this.

Vitamin D3 supplementation of cull cows: effects on longissimus and semitendinosus muscle tenderness.

Previous studies have shown that supplementation of vitamin D3 to cow diets for 4 to 10 d before slaughter lowers Warner-Bratzler shear force (WBSF) values and increases sensory tenderness scores in beef cuts. The present study was conducted to evaluate the effects of vitamin D3 supplementation on muscle calcium concentration, WBSF values, and sensory tenderness ratings of LM and semitendinosus (ST) muscles from cull, predominately Angus, cows (eight cows per treatment). Treatments included 0 (control), 5 million IU, or 7.5 million IU of vitamin D3 supplemented daily for 7 d preslaughter. Twenty-four hours after slaughter, 2.54-cm-thick LM and ST muscle steaks were cut; aged for either 0, 7, 14, or 21 d (ST steaks aged for 7 d only); and frozen at -20 degrees C for WBFS and sensory analysis. Mean values for LM calcium concentration tended to increase (P = 0.14) with vitamin D3 supplementation (154, 176, and 183 microig/g, fresh basis, for 0, 5, and 7.5 million IU/d, respectively). After 7 d of aging, LM steaks from cows fed 7.5 million IU had lower (P < 0.05) WBSF values than 7-d steaks from controls and cows fed 5.0 million IU/d aged 7 d; however, vitamin D3 supplementation had no (P > 0.05) effect on WBSF values of ST steaks aged 7 d. Vitamin D3 supplementation did not (P > 0.05) affect sensory tenderness ratings for either LM or ST steaks at any aging period. Aging, however, had a linear (P < 0.001) effect on tenderness, with an increase in tenderness as aging time increased from 0 to 21 d. Thus, results from the present study indicate that vitamin D3 supplementation, at these levels and duration before slaughter, provided little benefit to muscle tenderness of beef from cull cows.

Isolation and characterization of cytotoxic saponin chloromaloside A from Chlorophytum malayense.

A cytotoxic steroidal glycoside was isolated from Chlorophytum malayense Ridley and its structure was characterized as a known compound, neohecogenin 3-O-beta-D-glucopyranosyl(1-->2)-[beta-D-xylopyranosyl(1-->3)]-beta-D- glucopyranosyl(1-->4)-beta-D-galactopyranoside (chloromaloside A). The structural identification was performed using 2D-NMR and LC/MS/MS analysis. The previous, erroneously assigned 1H-NMR spectral data were revised whereas the published 13C-NMR spectral assignments were confirmed. This compound showed in vitro cytotoxicity against several human cancer cell lines.

Narcolepsy in orexin knockout mice: molecular genetics of sleep regulation.

Neurons containing the neuropeptide orexin (hypocretin) are located exclusively in the lateral hypothalamus and send axons to numerous regions throughout the central nervous system, including the major nuclei implicated in sleep regulation. Here, we report that, by behavioral and electroencephalographic criteria, orexin knockout mice exhibit a phenotype strikingly similar to human narcolepsy patients, as well as canarc-1 mutant dogs, the only known monogenic model of narcolepsy. Moreover, modafinil, an anti-narcoleptic drug with ill-defined mechanisms of action, activates orexin-containing neurons. We propose that orexin regulates sleep/wakefulness states, and that orexin knockout mice are a model of human narcolepsy, a disorder characterized primarily by rapid eye movement (REM) sleep dysregulation.

Comparative efficacies of liposomal amikacin (MiKasome) plus oxacillin versus conventional amikacin plus oxacillin in experimental endocarditis induced by Staphylococcus aureus: microbiological and echocardiographic analyses.

Optimal treatment strategies for serious infections caused by Staphylococcus aureus have not been fully characterized. The combination of a beta-lactam plus an aminoglycoside can act synergistically against S. aureus in vitro and in vivo. MiKasome, a new liposome-encapsulated formulation of conventional amikacin, significantly prolongs serum half-life (t1/2) and increases the area under the concentration-time curve (AUC) compared to free amikacin. Microbiologic efficacy and left ventricular function, as assessed by echocardiography, were compared in animals administered either oxacillin alone or oxacillin in combination with conventional amikacin or MiKasome in a rabbit model of experimental endocarditis due to S. aureus. In vitro, oxacillin, combined with either free amikacin or MiKasome, prevented the bacterial regrowth observed with aminoglycosides alone at 24 h of incubation. Rabbits with S. aureus endocarditis were treated with either oxacillin alone (50 mg/kg, given intramuscularly three times daily), oxacillin plus daily amikacin (27 mg/kg, given intravenously twice daily), or oxacillin plus intermittent MiKasome (160 mg/kg, given intravenously, a single dose on days 1 and 4). The oxacillin-alone dosage represents a subtherapeutic regimen against the infecting strain in the endocarditis model (L. Hirano and A. S. Bayer, Antimicrob. Agents Chemother. 35:685-690, 1991), thus allowing recognition of any enhanced bactericidal effects between oxacillin and either aminoglycoside formulation. Treatment was administered for either 3 or 6 days, and animals were sacrificed after each of these time points or at 5 days after a 6-day treatment course (to evaluate for posttherapy relapse). Left ventricular function was analyzed by utilizing serial transthoracic echocardiography during treatment and posttherapy by measurement of left ventricular fractional shortening. At all sacrifice times, both combination regimens significantly reduced S. aureus vegetation counts versus control counts (P < 0.05). In contrast, oxacillin alone did not significantly reduce S. aureus vegetation counts after 3 days of therapy. Furthermore, at this time point, the two combinations were significantly more effective than oxacillin alone (P < 0.05). All three regimens were effective in significantly decreasing bacterial counts in the myocardium during and after therapy compared to controls (P < 0.05). In kidney and spleen abscesses, all regimens significantly reduced bacterial counts during therapy (P < 0.0001); however, only the combination regimens prevented bacteriologic relapse in these organs posttherapy. By echocardiographic analysis, both combination regimens yielded a significant physiological benefit by maintaining normal left ventricular function during treatment and posttherapy compared with oxacillin alone (P < 0.001). These results suggest that the use of intermittent MiKasome (similar to daily conventional amikacin) enhances the in vivo bactericidal effects of oxacillin in a severe S. aureus infection model and preserves selected physiological functions in target end organs.