ABSTRACT
Virtual reality (VR)-based training has shown some benefits in medical education, supporting skill acquisition, and helping reduce anxiety in real-world settings. However, the use of VR simulators in veterinary education remains limited. This study aimed to introduce a VR simulator to support veterinarian training in canine anaesthesia induction and endotracheal intubation. This study involved a group that learned solely with instructional videos (video group), and one that learned concurrently with the video and VR simulator (VR group). Third- and fourth-year veterinary students were included and underwent a descriptive test on canine endotracheal intubation. Canine endotracheal intubation success rates were compared between the video (n = 364) and VR (n = 60) groups of fifth-year students. A survey on the VR usability was conducted (n=91). The median descriptive test scores improved in the VR (63.3/100) vs the video group (51.5/100). The canine intubation success rates were comparable in the VR and video groups at 84.3â¯% and 77.4â¯%, respectively. A total of 90.1â¯% of the surveyed students rated the ease of use of the simulator highly. Overall, VR simulators were well-received, suggesting benefits in new skill retention. Further studies are required to evaluate the extent of skill improvement through VR-based training, compared to conventional methods, and to assess its impact on student motivation. Evaluating the long-term effects of VR-based training on skill development and retention will also provide a deeper understanding of its educational benefits.
ABSTRACT
We utilized electrostatic interaction to induce rapid crystallization of streptavidin. Simply mixing streptavidins possessing either a positively or negatively charged peptide at their C-terminus generated diffraction-quality crystals in a few hours. We modified the streptavidin crystals with fluorescent molecules using biotin, demonstrating the concept of protein crystals as functional biomaterials.
Subject(s)
Peptides/chemistry , Streptavidin/chemistry , Biotin/analogs & derivatives , Biotin/chemistry , Biotinylation , Crystallization , DNA/chemistry , Dendrimers/chemistry , Fluoresceins/chemistry , Fluorescent Dyes/chemistry , Static ElectricityABSTRACT
AIM: This study evaluated the effects of a glucagon-like peptide-1 receptor agonist on gastrointestinal (GI) tract motility and residue rates by examining GI transit time and lumen using capsule endoscopy. MATERIAL AND METHODS: GI motility and lumen were assessed by capsule endoscopy before and after liraglutide administration in 14 patients with type 2 diabetes mellitus (T2DM). RESULTS: Gastric transit time in the group with diabetic neuropathy (DN) was 1:12:36±1:04:30h before liraglutide administration and 0:48:40±0:32:52h after administration (nonsignificant difference, P=0.19). Gastric transit time in the non-DN group was 1:01:30±0:52:59h before administration and 2:33:29±1:37:24h after administration (significant increase, P=0.03). Duodenal and small intestine transit time in the DN group was 4:10:34±0:25:54h before and 6:38:42±3:52:42h after administration (not significant, P=0.09) and, in the non-DN group, 3:51:03±0:53:47h before and 6:45:31±2:41:36h after administration (significant increase, P=0.03). The GI residue rate in the DN group was 32.1±24% before administration and 90.0±9.1% after administration (significant increase, P<0.001), and increased in all patients; in the non-DN group, it was 32.1±35.3% before and 78.3±23.9% after administration (significant increase, P<0.001), and also increased in all patients. CONCLUSION: Liraglutide causes delayed gastric emptying and inhibits duodenal and small intestine motility. However, these GI movement-inhibiting effects may be decreased or absent in patients with DN-associated dysautonomia.
Subject(s)
Diabetic Neuropathies/physiopathology , Gastrointestinal Motility/drug effects , Gastrointestinal Transit/drug effects , Glucagon-Like Peptide-1 Receptor/agonists , Liraglutide/pharmacology , Aged , Capsule Endoscopy , Humans , Male , Middle Aged , Phenylethyl Alcohol/analogs & derivativesABSTRACT
The rolling rate (r) dependence of textures was investigated in the Ti-26Nb-3Al (mol%) alloy to reveal the conditions required to form the {001}<110> recrystallization texture, which is a desirable orientation for the ß-titanium shape memory alloy. {001}<110> was the dominant cold-rolling texture when r=90% and it was transferred to the recrystallization texture without forming {112}<110>, which is detrimental for the isotropic mechanical properties of the rolled sheet. A further increase in r resulted in the formation of {112}<110> in both rolling and recrystallization textures. Therefore, r should be controlled to form only the {001}<110> rolling texture, because the {112}<110> texture can overwhelm the {001}<110> texture during recrystallization.
Subject(s)
Dental Alloys/chemistryABSTRACT
PURPOSE: To investigate the efficacy of the combination of ultrasound-guided rectus sheath (RS) and transversus abdominis plane (TAP) blocks compared with TAP or RS block alone in gynecological single-incision laparoscopic surgery (SILS). MATERIALS AND METHODS: Bilateral TAP blocks (Group A, n = 12), TAP and RS blocks (Group B, n = 12), and RS blocks (Group C, n = 12) with 40 ml ropivacaine/patient were performed for ovarian tumor SILS. The analgesic effects were evaluated using a numerical rating scale (NRS) at zero, six, 12, 24, and 48 hours post-surgery. RESULTS: Umbilical pain on completion of general anesthesia was significantly less frequent in Group B (1/12) than Group A (7/12) (p = 0.03). The postoperative NRS scores were significantly lower in Group B than Group A at zero (p = 0.02) and six (p = 0.03) hours and Group C at zero (p = 0.001), six (p = 0.02), and 12 (p = 0.004) hours. CONCLUSION: The combination of RS and TAP blocks reduced early postoperative pain compared with RS or TAP block alone for gynecological SILS.
Subject(s)
Gynecologic Surgical Procedures/adverse effects , Laparoscopy/adverse effects , Nerve Block , Ovarian Neoplasms/surgery , Pain, Postoperative/prevention & control , Abdominal Muscles , Abdominal Wall , Adult , Amides/therapeutic use , Anesthesia, General , Female , Humans , Middle Aged , Pain, Postoperative/diagnosis , Pain, Postoperative/etiology , Retrospective Studies , Ropivacaine , Young AdultABSTRACT
La maloclusión pseudoclase III es caracterizada par un desequilibrio funcional que, por lo general, resulta de contactos oclusales prematuros que causan un desplazamiento funcional anterior de la mandíbula. Estos casos, si no son tratados en una etapa inicial de desarrollo, pueden generar interferencias en el crecimiento normal de las bases óseas y resultar en una deformidad facial. Este papel conlleva a la selecci6n de un aparato apropiado, tomando cuenta opciones actuales, para una intervenci6n temprana en el desarrollo de maloclusiones de clase III. El uso del aparato progenico en este tipo de maloclusión, permite la correcci6n dental en pocos meses y una estabilidad terapéutica de la mandíbula mesio-posicionada fomentando un crecimiento esquelético favorable en una niña de 5,6 años de edad que acude a la clínica de postgrado del Instituto Latino Americano de Investigaci6n y Enseñanza Odontológica (ILAPEO) en Curitiba, Brasil...
Pseudo Class III malocclusion is a functional imbalance that generally results from premature occlusal contacts that causes a functional anterior displacement of the mandible. These cases, if not treated at an early stage of development, may interfere in normal growth of bone bases, resulting in facial deformity. This paper suggests the selection of an adequate appliance considering the available possibilities for early intervention of Class III malocclusion. The use of the progenic appliance in such dental malocclusion allows correction in a few months and therapeutic stability mesio-positioned mandible encouraging favorable skeletal growth in a child of 5.6 years of age who came to the Postgraduate Clinic of the Latin American Institute of Dental Research and Education (ILAPEO) in Curitiba, Brazil...
Subject(s)
Humans , Female , Child, Preschool , Malocclusion, Angle Class III , Orthodontics, Corrective , BrazilABSTRACT
Two analytical methods for the evaluation of photocatalytic oxidation and reduction abilities were developed using a photocatalytic microreactor; one is product analysis and the other is reaction rate analysis. Two simple organic conversion reactions were selected for the oxidation and reduction. Since the reactions were one-to-one conversions from the reactant species to the product species, the product analysis was simply performed using gas chromatography, and the reactions were monitored in situ in the photocatalytic microreactor using the UV absorption spectra. The partial oxidation and reduction abilities for each functional group can be judged from the yield and selectivity, and the corresponding reaction rate, while the total oxidation ability can be judged from the conversion. We demonstrated the application of these methods for several kinds of visible light photocatalysts.
ABSTRACT
WHAT IS KNOWN AND OBJECTIVE: Both itraconazole (ITCZ) and voriconazole (VCZ) are potent inhibitors of cytochrome P450 (CYP) 3A, and their effects have been reported to be equal. However, ITCZ is metabolized by CYP3A, whereas VCZ is mainly metabolized by CYP2C9 and CYP2C19 and only partially by CYP3A. We experienced the case of a patient who showed a 5-fold increase in trough levels of tacrolimus (FK) level after switching from ITCZ to VCZ. Our objective is to discuss the mechanism of the increase drug-drug interaction in terms of serum concentration of the azole drugs and patient pharmacogenomics. CASE SUMMARY: A 53-year-old woman was treated with FK (1 mg/day) for lupus nephritis. Because fungal infection was suspected, she received ITCZ (100 mg/day). When ITCZ was replaced with VCZ (400 mg/day), the blood concentration of FK increased markedly from 6·1 to 34·2 ng/mL. During coadministration with FK, the levels of ITCZ and VCZ were 135·5 ng/mL and 5·5 µg/mL, respectively, with the VCZ level around 3-fold higher than the previously reported level (1·4-1·8 µg/mL). Her CYP genotypes were CYP2C19*1/*2, CYP3A4*1/*1 and CYP3A5*3/*3. WHAT IS NEW AND CONCLUSION: The patient was a CYP2C19 intermediate metabolizer (IM) and deficient in CYP3A5. The increase in plasma VCZ level appears to have been at least in part, associated with the CYP2C19 IM phenotype. One possible explanation for the marked increase in blood FK concentration was increased inhibition of CYP3A because of the impaired metabolism and subsequent increased plasma concentration of VCZ. This case shows that the severity of drug interactions may be influenced by metabolic gene polymorphism.
Subject(s)
Antifungal Agents/pharmacokinetics , Immunosuppressive Agents/pharmacokinetics , Lupus Nephritis/drug therapy , Tacrolimus/pharmacokinetics , Antifungal Agents/pharmacology , Aryl Hydrocarbon Hydroxylases/genetics , Cytochrome P-450 CYP2C19 , Cytochrome P-450 CYP3A/genetics , Drug Interactions , Female , Genotype , Humans , Immunosuppressive Agents/therapeutic use , Itraconazole/pharmacokinetics , Itraconazole/pharmacology , Middle Aged , Pharmacogenetics , Polymorphism, Genetic , Pyrimidines/pharmacokinetics , Pyrimidines/pharmacology , Tacrolimus/therapeutic use , Triazoles/pharmacokinetics , Triazoles/pharmacology , VoriconazoleABSTRACT
Quantitation of individual monoclonal antibodies (mAbs) within a combined antibody drug product is required for preclinical and clinical drug development, including pharmacokinetic (PK), toxicology, stability, and biochemical characterization studies of such drugs. We have developed an antitoxin, XOMA 3AB, consisting of three recombinant mAbs that potently neutralize the known subtypes of type A botulinum neurotoxin (BoNT/A). The three mAbs bind nonoverlapping BoNT/A epitopes with high affinity. XOMA 3AB is being developed as a treatment for botulism resulting from BoNT/A. To develop antibody-specific assays, we cloned, expressed, and purified BoNT/A domains from Escherichia coli. Each mAb bound only to its specific domain with affinity comparable to the binding to holotoxin. mAb-specific domains were used to develop an enzyme-linked immunosorbent assay (ELISA) for characterization of the integrity and binding activity of the three mAbs in the drug product. An electrochemiluminescence bridging assay that is robust to interference from components in serum was also developed, and we demonstrate that it can be used for PK assays. This type of antigen engineering to generate mAb-specific domains is a general method allowing quantitation and characterization of individual mAbs in a mAb cocktail that binds the same protein and is superior to anti-idiotype approaches.
Subject(s)
Antibodies, Monoclonal/analysis , Botulinum Toxins, Type A/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/analysis , Antibodies, Neutralizing/immunology , Botulinum Toxins, Type A/chemistry , Botulinum Toxins, Type A/genetics , Botulinum Toxins, Type A/isolation & purification , Chromatography, Gel , Chromatography, High Pressure Liquid , Cloning, Molecular , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Protein ConformationABSTRACT
A 52-year-old woman who presented with acute onset of chest pain was diagnosed with Stanford type A acute aortic dissection by computed tomography at another hospital. She was referred to our department for emergency surgery. The left pericardium visualized via a median sternotomy was clearly defective, and the left phrenic nerve was located ventral to the defect. The ascending aorta and total arch were replaced with an aortic valve and a prosthetic graft, respectively. Postoperative chest radiography excluded left phrenic nerve palsy. The postoperative course was uneventful and the patient was discharged on postoperative day 17.
Subject(s)
Aortic Aneurysm/surgery , Aortic Dissection/surgery , Pericardium/abnormalities , Acute Disease , Female , Humans , Middle AgedABSTRACT
Anti-CD20 antibody rituximab is now essential for the treatment of CD20-positive B-cell lymphomas. Decreased expression of CD20 is one of the major mechanisms underlying both innate and acquired resistance to rituximab. In this study, we show that histone deacetylase (HDAC) inhibitors augment the cytotoxic activity of rituximab by enhancing the surface expression of CD20 antigen on lymphoma cells. HDAC inhibitors, valproic acid (VPA) and romidepsin, increased CD20 expression at protein and mRNA levels in B-cell lymphoma cell lines with relatively low CD20 expression levels. The VPA-mediated increase in CD20 expression occurred at 1 m, which is clinically achievable and safe, but insufficient for inducing cell death. Chromatin immunoprecipitation assays revealed that HDAC inhibitors transactivated the CD20 gene through promoter hyperacetylation and Sp1 recruitment. HDAC inhibitors potentiated the activity of rituximab in complement-dependent cytotoxic assays. In mouse lymphoma models, HDAC inhibitors enhanced CD20 expression along with histone hyperacetylation in transplanted cells, and acted synergistically with rituximab to retard their growth. The combination with HDAC inhibitors may serve as an effective strategy to overcome rituximab resistance in B-cell lymphomas.
Subject(s)
Antibodies, Monoclonal/pharmacology , Antigens, CD20/metabolism , Depsipeptides/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Lymphoma, B-Cell/drug therapy , Lymphoma, B-Cell/metabolism , Valproic Acid/pharmacology , Acetylation , Animals , Antibiotics, Antineoplastic/pharmacology , Antibodies, Monoclonal, Murine-Derived , Antineoplastic Agents/pharmacology , Antineoplastic Combined Chemotherapy Protocols , Apoptosis/drug effects , Blotting, Western , Cell Proliferation/drug effects , Chromatin Immunoprecipitation , Drug Synergism , Flow Cytometry , Humans , Lymphoma, B-Cell/pathology , Mice , Mice, SCID , Promoter Regions, Genetic/genetics , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , RituximabSubject(s)
Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Mutation/genetics , Ribosomal Protein S6 Kinases, 90-kDa/metabolism , fms-Like Tyrosine Kinase 3/genetics , Apoptosis , Cell Movement , Cell Proliferation , Enzyme Activation , Flow Cytometry , Fusion Proteins, bcr-abl/metabolism , Humans , Immunoblotting , Janus Kinase 2/metabolism , Leukemia, Myeloid, Acute/pathology , Phosphorylation , Prognosis , RNA, Small Interfering/pharmacology , Ribosomal Protein S6 Kinases, 90-kDa/antagonists & inhibitors , Ribosomal Protein S6 Kinases, 90-kDa/genetics , STAT5 Transcription Factor/metabolism , Tandem Repeat Sequences/genetics , Tumor Cells, Cultured , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
Multiple myeloma (MM) is incurable, mainly because of cell adhesion-mediated drug resistance (CAM-DR). In this study, we performed functional screening using short hairpin RNA (shRNA) to define the molecule(s) responsible for CAM-DR of MM. Using four bona fide myeloma cell lines (KHM-1B, KMS12-BM, RPMI8226 and U266) and primary myeloma cells, we identified CD29 (beta1-integrin), CD44, CD49d (alpha4-integrin, a subunit of VLA-4), CD54 (intercellular adhesion molecule-1 (ICAM-1)), CD138 (syndecan-1) and CD184 (CXC chemokine receptor-4 (CXCR4)) as major adhesion molecules expressed on MM. shRNA-mediated knockdown of CD49d but not CD44, CD54, CD138 and CD184 significantly reversed CAM-DR of myeloma cells to bortezomib, vincristine, doxorubicin and dexamethasone. Experiments using blocking antibodies yielded almost identical results. Bortezomib was relatively resistant to CAM-DR because of its ability to specifically downregulate CD49d expression. This property was unique to bortezomib and was not observed in other anti-myeloma drugs. Pretreatment with bortezomib was able to ameliorate CAM-DR of myeloma cells to vincristine and dexamethasone. These results suggest that VLA-4 plays a critical role in CAM-DR of MM cells. The combination of bortezomib with conventional anti-myeloma drugs may be effective in overcoming CAM-DR of MM.
Subject(s)
Boronic Acids/pharmacology , Cell Adhesion/physiology , Drug Resistance, Neoplasm/drug effects , Integrin alpha Chains/physiology , Integrin alpha4/physiology , Integrin alpha4beta1/physiology , Multiple Myeloma/metabolism , Neoplasm Proteins/physiology , Pyrazines/pharmacology , Antibodies/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Bortezomib , Cell Adhesion Molecules/physiology , Cell Line, Tumor/metabolism , Dexamethasone/pharmacology , Down-Regulation , Doxorubicin/pharmacology , Drug Resistance, Neoplasm/physiology , Gene Expression Regulation, Neoplastic/drug effects , Gene Knockdown Techniques , Humans , Integrin alpha Chains/biosynthesis , Integrin alpha Chains/genetics , Integrin alpha4/biosynthesis , Integrin alpha4/genetics , Multiple Myeloma/drug therapy , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , Vincristine/pharmacologyABSTRACT
This study was conducted to examine the effects of the reproductive cycle of donor cat on the quality of oocytes at recovery and developmental competence of oocytes after in vitro fertilization (IVF) and somatic cell nuclear transfer (NT). Based on the presence or absence of follicles and corpora lutea, the ovarian pairs collected were classified into inactive, follicular or luteal stages. After collection of oocytes, the oocytes were classified into four grades according to the morphological condition of oocyte cytoplasm and cumulus cells. A total of 16 558 oocytes were obtained from 198 ovarian pairs. The total mean numbers of oocytes and the mean numbers of oocytes with high quality (grade I) were significantly higher in ovarian pairs at the inactive stage (111.1 and 19.0 oocytes, respectively) than in ovarian pairs at the follicular stage (67.1 and 11.4 oocytes, respectively). A significant difference in the proportions of oocytes with grade I out of the total examined oocytes was observed between the follicular and luteal stages of ovaries (14.9% vs 20.2%, p < 0.05). The proportions of IVF embryos cleaved and developed to blastocysts significantly decreased with decreased quality of oocytes at recovery, irrespective of the reproductive status of ovaries. Moreover, there were no significant differences in the proportions of cleavage and development to the blastocyst stage of IVF and NT embryos among three oestrous stages of ovaries. These results indicate that the reproductive cycle stage of donor cat ovaries has no apparent effects on the in vitro development of oocytes after IVF and NT, but the quality of oocytes at recovery influences the development of IVF embryos.
Subject(s)
Fertilization in Vitro/veterinary , Nuclear Transfer Techniques/veterinary , Oocytes/physiology , Animals , Blastocyst/physiology , Cats , Culture Techniques , Female , Male , Ovarian Follicle/cytologyABSTRACT
PKC412 is a staurosporine derivative that inhibits several protein kinases including FLT3, and is highly anticipated as a novel therapeutic agent for acute myeloblastic leukemia (AML) carrying FLT3 mutations. In this study, we show that PKC412 exerts differential cell cycle effects on AML cells depending on the presence of FLT3 mutations. PKC412 elicits massive apoptosis without markedly affecting cell cycle patterns in AML cell lines with FLT3 mutations (MV4-11 and MOLM13), whereas it induces G2 arrest but not apoptosis in AML cell lines without FLT3 mutations (THP-1 and U937). In MV4-11 and MOLM13 cells, PKC412 inactivates Myt-1 and activates CDC25c, leading to the activation of CDC2. Activated CDC2 phosphorylates Bad at serine-128 and facilitates its translocation to the mitochondria, where Bad triggers apoptosis. In contrast, PKC412 inactivates CDC2 by inducing serine-216 phosphorylation and subsequent cytoplasmic sequestration of CDC25c in THP-1 and U937 cells. As a result, cells are arrested in the G2 phase of the cell cycle, but do not undergo apoptosis because Bad is not activated. The FLT3 mutation-dependent differential cell cycle effect of PKC412 is considered an important factor when PKC412 is combined with cell cycle-specific anticancer drugs in the treatment of cancer and leukemia.
Subject(s)
Cell Cycle/drug effects , Leukemia, Myeloid, Acute/genetics , Mutation , Staurosporine/analogs & derivatives , fms-Like Tyrosine Kinase 3/genetics , Apoptosis/drug effects , Apoptosis/genetics , CDC2 Protein Kinase , Cell Cycle/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin B/metabolism , Cyclin-Dependent Kinases , Humans , Leukemia, Myeloid, Acute/pathology , Phosphorylation , Serine/metabolism , Signal Transduction/drug effects , Signal Transduction/genetics , Staurosporine/pharmacology , U937 Cells , bcl-Associated Death Protein/metabolism , fms-Like Tyrosine Kinase 3/antagonists & inhibitors , fms-Like Tyrosine Kinase 3/metabolismABSTRACT
The objectives of the present study were to investigate the effects of the stage of the estrous cycle at the start of an estradiol benzoate (EB) and progesterone (P) based treatment protocol on new follicular wave emergence, subsequent estrus and ovulation. The experiment was conducted using a crossover design with each cow (five cross-bred cows) being assigned to one of three groups at 3-month intervals within a 1-year period. Estrous cycle stage in individual cows was initially synchronized with prostaglandin F(2)alpha. After detection of estrus, each cow was injected intramuscularly (i.m.) with 2 mg EB and 200 mg P (EB/P) on day 5, 12 or 17 of the estrous cycle (estrus=day 0), followed by 1 mg EB i.m. 12 days after the EB/P treatment. Ovarian ultrasonographic examinations showed that the emergence of a new follicular wave occurred after EB/P treatment in all groups and the mean interval from EB/P treatment to wave emergence did not differ among the groups (3.2-3.8 days). All cows in each group exhibited behavioral estrus and ovulated the newly formed dominant follicle. However, cows in the day-17 group exhibited estrus 1-3 days before the second EB injection. The concentrations of progesterone showed faster reduction, during the treatment period, in the day-12 and -17 groups compared to the day-5 group. These results indicate that the EB/P treatment induces an emergence of a new follicular wave, irrespective of the estrous cycle stage at the start of treatment, but the effect of EB/P protocol on estrous/ovulation synchronization is influenced by the stage of the estrous cycle.
Subject(s)
Cattle/physiology , Corpus Luteum/drug effects , Estrus/drug effects , Ovarian Follicle/drug effects , Ovulation/drug effects , Progesterone/blood , Animals , Cross-Over Studies , Estradiol/analogs & derivatives , Estradiol/pharmacology , Estrous Cycle/drug effects , Estrus Synchronization/drug effects , Female , Fertility Agents, Female/pharmacology , Progesterone/pharmacologyABSTRACT
The present study was conducted to examine the meiotic competence of canine oocytes embedded in collagen gel, and to investigate the effects of timed exposure of the oocytes embedded in collagen gel to gonadotrophins during maturation culture, on their nuclear maturation. Cumulus-oocyte complexes (COCs) were collected from bitches at the anoestrous and dioestrous stages of the reproductive cycle. In the first experiment, half of the COCs were embedded in collagen gels. The COCs with or without collagen-gel embedding were cultured in a TCM-199 medium supplemented with 0.1 IU/ml human menopausal gonadotropin (hMG) and 10 IU/ml human chorionic gonadotropin (hCG) for 72 h. In the second experiment, the COCs embedded in collagen gels were cultured in TCM-199 medium with gonadotrophins (hMG and hCG) for various periods (0, 24, 48 and 72 h) and then cultured in the medium without gonadotrophins until reaching total culture period (72 h). The percentage of the oocytes reaching metaphase I and metaphase II (MI/MII) was significantly higher (p < 0.05) in COCs with collagen-gel embedding than in COCs without collagen-gel embedding. The percentage of oocytes that were arrested at the germinal vesicle stage was significantly lower (p < 0.05) in oocytes cultured with gonadotrophins than in oocytes cultured without gonadotrophins. However, there were no significant differences in the percentages of oocytes that reached each stage of meiosis among the groups, irrespective of the duration of exposure to gonadotrophins. These observations indicate that embedding of COCs by collagen gel enhances the meiotic competence of canine oocytes, but removal of hormone supplement from maturation medium does not improve the ability of the oocytes to reach MII stage.
Subject(s)
Dogs/physiology , Gonadotropins/pharmacology , Meiosis/drug effects , Meiosis/physiology , Oocytes/physiology , Anestrus/physiology , Animals , Cell Culture Techniques/veterinary , Collagen , Diestrus/physiology , FemaleABSTRACT
By using multiwalled carbon nanotubes as an element of a nanobiprism, we evaluated quantitatively the coherence of electrons emitted from tungsten tips at room temperature and 78 K, and found an enhancement of coherence at 78 K. The increase of the transverse coherence length of the electron beam agreed well with that of the inelastic mean free path of electrons in solids, demonstrating the direct relationship between the coherences of the electron beam and the original electronic states. On the basis of this experimental fact, we comment on the interpretation of recent Hanbury Brown-Twiss type experiments for electrons reported by Kiesel et al. [Nature (London) 418, 392 (2002)]].
ABSTRACT
O artigo não apresenta resumo.
ABSTRACT
To investigate the role of flagella and monomer flagellin in the interaction between Pseudomonas syringae pv. tabaci and plants, non-polar fliC and fliD mutants were produced. The ORFs for fliC and fliD are deleted in the DeltafliC and DeltafliD mutants, respectively. Both mutants lost all flagella and were non-motile. The DeltafliC mutant did not produce flagellin, whereas the DeltafliD mutant, which lacks the HAP2 protein, secreted large amounts of monomer flagellin into the culture medium. Inoculation of non-host tomato leaves with wild-type P. syringae pv. tabaci or the DeltafliD mutant induced a hypersensitive reaction (HR), whereas the DeltafliC mutant propagated and caused characteristic symptom-like changes. In tomato cells in suspension culture, wild-type P. syringae pv. tabaci induced slight, visible HR-like changes. The DeltafliC mutant did not induce HR, but the DeltafliD mutant induced a remarkably strong HR. Expression of the hsr203J gene was rapidly and strongly induced by inoculation with the DeltafliD mutant, compared to inoculation with wild-type P. syringae pv. tabaci. Furthermore, introduction of the fliC gene into the DeltafliC mutant restored motility and HR-inducing ability in tomato. These results, together with our previous study, suggest that the flagellin monomer of pv. tabaci acts as a strong elicitor to induce HR-associated cell death in non-host tomato cells.