The effect of bentonite concentration on the drug delivery efficacy of a pH-sensitive alginate/bentonite hydrogel     

Seung-Taek Oh  Oh-Jin Kwon  Byoung-Chul Chun  Jae-Whan Cho  Jong-Shin Park 《Fibers and Polymers》2009,10(1):21-26

We produced a protein loaded, pH-sensitive alginate-bentonite hydrogel for wound dressings. Alginate is a nontoxic polysaccharide with favorable pH-sensitive properties that make it useful for the intestinal delivery of protein drugs. However, the use of alginate for drug delivery is limited by drug leaching and rapid dissolution of alginate at the higher pH, which may result in lower entrapment efficiency and a burst in the release of entrapped protein drugs. To overcome these problems, we created a novel cross-linked alginate-bentonite hydrogel by combining mineral-rich bentonite with the alginate matrix along with an additive to ensure controlled release. We analyzed the gel in the drug loading process in an aqueous environment by looking at the release profiles of a model protein drug (BSA) from the hydrogel at pH values of 4.5, 5.2 (skin area) and 7.4, 9.2 (wound area). The swelling ratio decreased with bentonite concentration, but did not fall below 6. The rate of drug release was slowest at a pH value of 4.5 and fastest at a pH value of 9.2. The rate of drug release decreased with bentonite concentration. The presence of bentonite prevents the rapid dissolution of alginate at the higher pH, ensuring the controlled release of the entrapped drug.  相似文献   

Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets          下载免费PDF全文

HF Wan  JT Zhu  Y Shen  X Xiang  HJ Yin  ZF Fang  LQ Che  Y Lin  SY Xu  B Feng  D Wu 《Reproduction in domestic animals》2016,51(1):135-142

The effects of dietary β‐hydroxy‐β‐methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β‐hydroxy‐β‐methylbutyrate calcium (HMB‐Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor‐4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin‐like growth factor‐1 (IGF‐1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation.  相似文献   

Viscerotropic velogenic Newcastle disease virus replication in feathers of infected chickens     

Dong-Hun Lee  Jung-Hoon Kwon  Jin-Yong Noh  Jae-Keun Park  Seong-Su Yuk  Tseren-Ochir Erdene-Ochir  Sang-Soep Nahm  Yong-Kuk Kwon  Sang-Won Lee  Chang-Seon Song 《Journal of veterinary science (Suw?n-si, Korea)》2016,17(1):115-117

  相似文献   

Detection of Paranannizziopsis australasiensis in tuatara (Sphenodon punctatus) using fungal culture and a generic fungal PCR     

S Humphrey  S Alexander  HJ Ha 《New Zealand veterinary journal》2016,64(5):298-300

AIMS: To describe the methods used at the Animal Health Laboratory (AHL, Ministry for Primary Industries) to identify Paranannizziopsis australasiensis.

METHODS: Skin biopsy samples from two adult male tuatara were submitted to the AHL in March 2014. Approximately half of each sample was processed for fungal culture and incubated on mycobiotic agar containing cycloheximide at 30°C. Following morphological examination of the culture products, DNA was extracted from suspect colonies. PCR was used to amplify the internal transcribed spacer (ITS) region of fungal rRNA using primers ITS1 and ITS4. Positive amplicons were subjected to DNA sequencing and the results were compared to published sequences. In addition, DNA was extracted from the remaining skin samples and the same PCR was carried out to compare the results.

RESULTS: After 7 days of incubation, colonies morphologically resembling P. australasiensis were observed. DNA extracted from these isolates tested positive for P. australasiensis by PCR and DNA sequencing. Samples of DNA extracted directly from the infected skin samples tested negative for P. australasiensis using the generic fungal PCR.

CONCLUSIONS AND CLINICAL RELEVANCE: Isolation and identification of P. australasiensis was carried out using a combination of fungal culture and molecular testing available at AHL. Results were available in significantly less time than in the past, when isolates had to be sent overseas. PCR and sequencing of fungal isolates is a valuable tool for identification of species that have few, if any, unique macroscopic or microscopic features to aid identification. Further sampling from captive and wild New Zealand reptiles will provide important information on the epidemiology of P. australasiensis, and the conservation and management implications for tuatara and other native reptile species.  相似文献   

Transient ischaemia affects plasma membrane glutamate transporter, not vesicular glutamate transporter, expressions in the gerbil hippocampus   总被引：3，自引：0，他引：3  

Kim DS  Kwak SE  Kim JE  Jung JY  Won MH  Choi SY  Kwon OS  Kang TC 《Anatomia, histologia, embryologia》2006,35(4):265-270

In the present study, we investigated expressions of vesicular glutamate transporter (VGLUT) and of the plasma membrane glutamate transporters [glutamate transporter 1 (GLT-1), glutamate/aspartate transporter (GLAST) and excitatory amino acid carrier 1 (EAAC-1)] in the gerbil hippocampus following transient ischaemia. The expressional levels and distribution patterns of VGLUT immunoreactivities were unaltered until 3 days after ischaemic-insults. However, VGLUT-2 immunoreactivity in the CA1 region was reduced at 4 days after ischaemia due to delayed neuronal death. In addition, both GLT-1 and GLAST immunoreactivities in the CA1 region were enhanced at 30 min - 12 h after ischaemia-reperfusion and their expression began to reduce at 24 h after ischaemia-reperfusion. In contrast, EAAC-1 immunoreactivity was transiently reduced in the CA1 region at 30 min after ischaemia, re-enhanced at 3-12 h after ischaemia, and re-reduced at 24 h after ischaemia. These findings suggest that malfunctions of plasma membrane glutamate transporters, not of VGLUT, may play an important role in the elevation of extracellular glutamate concentration following ischaemic insults.  相似文献   

Molecular characterization of recent Korean porcine reproductive and respiratory syndrome (PRRS) viruses and comparison to other Asian PRRS viruses   总被引：14，自引：0，他引：14  

Cha SH  Choi EJ  Park JH  Yoon SR  Song JY  Kwon JH  Song HJ  Yoon KJ 《Veterinary microbiology》2006,117(2-4):248-257

Twenty-eight PRRS viruses (PRRSVs) isolated from various pig farms in Korea between 2002 and 2003 were sequenced for open-reading frame (ORF) 5 and/or full-length genome and compared with numerous PRRSVs reported from North America, Europe and Asia. All Korean isolates examined were genetically of the North American genotype. The ORF5 sequence of one isolate was identical to Ingelvac PRRS MLV vaccine virus. ORF5 nucleotide sequence divergence of the remaining 27 Korean PRRSVs from VR-2332, the prototype of the North American PRRSV and parental strain of the MLV vaccine virus, ranged from 1.3% to 12.9%, which corresponded to 2.0% to 14.9% divergence at the amino acid level, raising a concern on the efficacy of the MLV vaccine. Phylogenetic analyses of ORF5 and/or full-length sequences revealed that the Korean PRRSVs formed a clade distinct from PRRSVs reported from other Asian countries (China, Taiwan, Japan, and Thailand). Our study demonstrated that PRRSVs of the North American genotype were introduced to the Korean swine population some time ago and have evolved independently from PRRSV in other Asian countries, suggesting that geographic separation might influence the molecular evolution of PRRSV. This should be taken into consideration when a national PRRS prevention and control policy for international trade is established.  相似文献   

Antimicrobial resistance in Salmonella enterica serovars Enteritidis and Typhimurium isolated from animals in Korea: comparison of phenotypic and genotypic resistance characterization     

Yang SJ  Park KY  Kim SH  No KM  Besser TE  Yoo HS  Kim SH  Lee BK  Park YH 《Veterinary microbiology》2002,86(4):295-301

Fourteen and 22 each of Salmonella Enteritidis and Salmonella Typhimurium (S. Typhimurium) were isolated from animals from 1983 to 1999 in Korea and tested for their antibiotic resistance patterns, phage types and resistance gene patterns. S. Typhimurium isolates were highly resistant to streptomycin, sulfisoxazole and tetracycline, 95, 95 and 86%, respectively. The incidence of multiple antibiotic resistance (resistant to more than two drugs tested) of S. Typhimurium isolates was extremely high (100%) comparing to S. Enteritidis isolates (21%). Two of the five ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfisoxazole and tetracycline) resistant type S. Typhimurium isolates were phage type definitive type 104 (DT104).For the detection of resistance related genes in S. Enteritidis and S. Typhimurium isolates, particularly ACSSuT type S. Typhimurium, antibiotic resistance genes, cmlA/tetR, bla(PSE-1) and bla(TEM), and genus Salmonella specific gene, sipB/C, were amplified using four pairs of primers in a hot-start multiplex polymerase chain reaction (PCR). Two Korean isolates of S. Typhimurium DT104 showed bla(TEM) amplicons instead of bla(PSE-1) for the ampicillin resistance and they were susceptible to florfenicol. The multiplex PCR used in this study was useful in characterization of multiple drug resistant Salmonella isolates, especially ACSSuT type S. Typhimurium, and identification of beta-lactamase gene distribution among Salmonella isolates.  相似文献   

Molecular epidemiological investigation of Newcastle disease virus from domestic ducks in Korea     

Lee EK  Jeon WJ  Kwon JH  Yang CB  Choi KS 《Veterinary microbiology》2009,134(3-4):241-248

To expand the epidemiological understanding of Newcastle disease virus (NDV) found in domestic ducks in Korea, 14 NDV isolates from apparently healthy domestic ducks were biologically and genetically characterized. Thirteen and 1 isolates of NDV were categorized into lentogenic and velogenic viruses, respectively, based on in vivo pathogenicity tests. Twelve lentogenic viruses showed HA activity to horse RBCs, while 1 lentogenic virus and the velogenic virus were negative. Lentogenic viruses (n=13) had sequence motifs of (112)ERQERL(117) (n=1) or (112)GRQGRL(117) (n=12) at the F0 cleavage site, while the velogenic virus (n=1) had a sequence motif of (112)RRQKRF(117) at the same site. Phylogenetic analysis revealed that at least three distinct genotypes may exist in domestic ducks in Korea; one class I genotype (genotype 2), and two class II (genotypes I and VII) genotypes. The class I virus was most closely related to strains of genotype 2 which were isolated in birds from the USA, Germany and Denmark. Twelve lentogenic class II viruses were grouped together in genotype I, and were then divided into at least three clusters, namely Aomori-like, Ulster2C-like, and V4-like. The velogenic class II virus was assigned to genotype VII which represents viruses responsible for recent epidemics in many Asian countries including Korea. The epidemiological importance of domestic duck isolates of NDV in Korea is discussed.  相似文献   

Shortening the Postpartum Anoestrous Interval in Suckled Crossbred Dual Purpose Cows Using Progestagen Intravaginal Sponges plus eCG and PGF_2α     

JC Gutiérrez  R Palomares  R González  G Portillo  M Montero-Urdaneta  J Rubio-Guillén  HJ. Hernández-Fonseca  E Soto-Belloso 《Reproduction in domestic animals》2009,44(1):48-54

One hundred and twenty‐six suckled crossbred cows (Bos taurus × Bos indicus), with body condition score ≥3 (1–5 point scale), were employed in the present study to evaluate the effectiveness of intravaginal progestin‐releasing sponges (IVS) for shortening anoestrous interval. Fifty‐four cows were assigned to control group. Seventy‐two cows were treated with IVS impregnated with 250 mg of medroxy‐acetate‐progesterone (MAP) as follows: day 0, IVS plus 5 mg of 17β‐E and 50 mg of MAP i.m.; day 6, 500 IU of equine chorionic gonadotropin and 25 mg prostaglandin F_2α i.m.; day 8, IVS withdrawal and day 9, 1 mg 17β‐E i.m. Cows were also grouped according to postpartum days (dpp) at treatment: MAP <70 days (n = 25); control <70 days (n = 22); MAP >70 days (n = 47); control >70 days (n = 32). From IVS removal, cows were detected in oestrus and inseminated. Cows not detected in oestrus were timed artificial insemination 72 h after sponge removal. Treatment effect on oestrous rate (ER), conception rate (CR), pregnancy rate (PR) and treatment to conception intervals (TCI) and calving to conception intervals (CCI) were evaluated. The ER, CR and PR were analysed using proc logistic , while TCI and CCI with proc glm of SAS. The groups MAP <70 days and MAP >70 days showed higher (p < 0.01) ER than control <70 days and control >70 days (84.0% and 76.6% vs 31.8% and 31.3% respectively). The PR was higher (p < 0.01) in MAP <70 days vs control <70 days (64.0% vs 22.7%) and also higher (p < 0.05) in MAP >70 days vs control <70 days (40.4% vs 18.8%). The TCI and CCI were shorter (p < 0.01) in MAP <70 days vs control <70 days (36.0 and 95.8 days; 95.3 and 158.6 days respectively). In conclusion, only cows treated with IVS before 70 dpp had a CCI shorter than 100 days, consequently this treatment shortened postpartum anoestrous interval in crossbred dual purpose cattle.  相似文献   

Diagnosis of Endometritis in the Bitch: A New Approach     

E Fontaine  X Levy  A Grellet  A Luc  F Bernex  HJ Boulouis  A Fontbonne 《Reproduction in domestic animals》2009,44(S2):196-199

There are a few investigations into endometritis in the bitch and its relationship with failure to conceive remains unclear. This may be because of the difficulty in collecting uterine samples for further investigations. Recently, transcervical catheterization by vaginal endoscopy has been introduced allowing the evaluation of the endometrium. In this study, uterine cytology and bacteriology were evaluated in 26 infertile bitches. Endometritis was bacterial in origin in most cases (70% of affected bitches), but these results may be underestimated, as some other pathogens (anaerobic bacteria, mycoplasms and fungi) were not investigated. Endometritis, in our opinion, should be investigated in each case of unexplained infertility in bitches. The method used here seems reliable although defining more accurate classification criteria will improve the efficiency of this non-invasive technique.  相似文献