144 Oct-4 EXPRESSION PATTERN IN THE EQUINE EMBRYO

Oct-4 is a key transcription factor in the control of early embryonic development and maintenance of a pluripotent cell population. Variation in Oct-4 expression patterns during embryo development have been reported among species, and have been related to the time of placental development in those species. This study was conducted to investigate Oct-4 expression pattern during early embryonic development in the horse, a species with relatively delayed placentation. In vitro-produced embryos were obtained from in vitro-matured oocytes via fertilization by intracytoplasmic sperm injection. Ex vivo blastocysts were recovered from mares that had been artificially inseminated. Oct-4 status was determined by immunocytochemistry; photomicrographs were taken at 4 standardized settings to aid in qualitative comparison of the amount of fluorescence. A total of 106 oocytes and embryos were evaluated. Immature oocytes showed Oct-4 expression in the nucleus and cytoplasm, as did early-cleaved embryos (2 to 5 cells, 1 to 2 days). Oct-4 expression in embryos at 3 to 4 days (6 to 12 cells) decreased and was restricted to the cytoplasm. From 5 to 6 days (15 cells to morulae), Oct-4 intensity increased and was exclusively found in the nuclei. In vitro-produced blastocysts (7 to 8 days) expressed Oct-4 equivalently in the trophectoderm and inner cell mass nuclei; culture for 2 to 3 more days (10 to 11 days) did not alter Oct-4 expression. However, when in vitro-produced blastocysts were transferred to the uteri of mares and recovered after 2 to 3 days (IVP-ET), the embryos showed strong expression of Oct-4 within the inner cell mass and limited expression in the trophectoderm, and a similar pattern was seen for ex vivo-recovered embryos. In bigger embryos (such as a 1779-�m ex vivo embryo and a 1121-�m IVP-ET embryo), the trophectoderm lost staining completely. These results suggest that Oct-4 expression is present in both nucleus and cytoplasm in equine oocytes and early-cleaved embryos as a result of maternal mRNA accumulation. Oct-4 protein decreases over the first few days of embryonic development as these stores are used. The shift to greater expression, in the nucleus only, during further embryo development suggests embryonic genome activation. Oct-4 expression in the trophectoderm of in vitro-produced blastocysts was different from that in blastocysts that had been exposed to the uterus (both ex vivo and IVP-ET); this indicates that differentiation of the trophectoderm is dependent upon factors present in the uterine environment. The Oct-4 expression in the trophectoderm of in vitro-produced equine blastocysts thus appears to be an artifact due to in vitro culture; this finding may be applicable to the reported patterns of Oct-4 expression in embryos of other species. This work was supported by the Link Equine Research Endowment Fund, Texas A&M University.

Emerging invasive liver abscess caused by K1 serotype Klebsiella pneumoniae in Korea

OBJECTIVES

The high incidence of invasive liver abscess caused by Klebsiella pneumoniae in Taiwan, contrasted with the rareness of this disease in Western countries, has aroused special interest. There have been few detailed reports from other Asian countries. To investigate a current epidemiology of K. pneumoniae liver abscess in Korea and to determine K serotype distribution in K. pneumoniae strains causing liver abscess, we performed a nationwide prospective study.

METHODS

Community-acquired, culture-proven liver abscess cases were enrolled between 2004 and 2005. Etiologies and clinical features were analyzed. K. pneumoniae isolates were serotyped according to K antigen. Meta-analysis was done to determine the time trend of the etiologies of liver abscess in Korea.

RESULTS

Out of 371 cases collected prospectively, 290 (78.2%) were caused by K. pneumoniae. Most K. pneumoniae liver abscesses were monomicrobial. Diabetes mellitus was the most common underlying disease (39.9%). Distant metastatic infections were frequently observed (8.7%). magA PCR revealed that 95 (59.4%) out of 160 K. pneumoniae isolates belonged to the K1 serotype.

CONCLUSIONS

Our study indicates that K. pneumoniae has emerged as a major etiologic agent of liver abscess in Korea, and these emerging infections seem to be attributable to invasive K. pneumoniae strains with capsular K1 serotype.

Production of horse foals via direct injection of roscovitine-treated donor cells and activation by injection of sperm extract

We evaluated the effects of different donor cell treatments and activation methods on production of blastocysts after equine nuclear transfer. Nuclear transfer was performed by direct injection of donor cells, using a piezo drill, and standard activation was by injection of sperm factor followed by culture with 6-dimethylaminopurine. There was no difference in blastocyst development between embryos produced with roscovitine-treated or confluent donor cells (3.6% for either treatment). Addition of injection of roscovitine or culture with cycloheximide at the time of activation did not affect blastocyst development. Overall, transfer of eight blastocysts produced using roscovitine-treated donor cells and our standard activation protocol yielded three pregnancies, of which two (25% of transferred embryos) resulted in delivery of viable foals. Flow cytometric evaluation showed that roscovitine treatment significantly increased the proportion of cells classified as small, in comparison to growth to confluence or serum deprivation, but did not significantly affect the proportion of cells in G0/G1 (2N DNA content). Transfer of one blastocyst produced using roscovitine-treated donor cells, with addition of roscovitine injection at activation, yielded one pregnancy which was lost before 114 days' gestation. Transfer to recipients of two blastocysts produced using confluent donor cells with addition of cycloheximide at activation gave no resulting pregnancies. We conclude that roscovitine treatment of donor cells yields equivalent blastocyst production after nuclear transfer to that for confluent donor cells, and that direct injection of roscovitine-treated donor cells, followed by activation using sperm extract, is compatible with efficient production of viable cloned foals.

Holding immature equine oocytes in the absence of meiotic inhibitors: Effect on germinal vesicle chromatin and blastocyst development after intracytoplasmic sperm injection

Holding immature oocytes before the onset of maturation simplifies oocyte transport and aids in scheduling later manipulations. We report here a method for holding equine oocytes in the absence of meiotic inhibitors. In Experiment 1, immature oocytes with expanded cumuli were cultured at 38.2 degrees C in medium containing cycloheximide, or were held at room-temperature in M199 with Hanks' salts, for 16-18 h before maturation. Control oocytes were matured immediately after recovery. Oocytes were fertilized by intracytoplasmic sperm injection and cultured for 4d. Embryo development was not different among treatments. In Experiment 2, oocytes were treated as in Experiment 1, but embryos were cultured for 7.5d. Blastocyst development was significantly lower in the cycloheximide-treated group than in controls (7% versus 30%) with the room-temperature group intermediate (16%). In Experiment 3, oocytes were cultured at 38.2 degrees C in medium containing roscovitine, or were held at room temperature in sealed glass vials in a mixture of 40% M199 with Earle's salts, 40% M199 with Hanks' salts, and 20% FBS (EH treatment) for 16-18 h, before maturation, sperm injection, and embryo culture for 7.5d. Blastocyst development of oocytes in the EH treatment was significantly higher than that for roscovitine-treated oocytes (34% versus 12%), but not significantly different from that for controls (25%). Oocytes in the EH treatment did not mature during holding (70% germinal vesicle stage after 18 h holding). Whereas culture with cycloheximide or roscovitine of equine oocytes with expanded cumuli reduced subsequent blastocyst formation, these oocytes could be held in a modified M199 at room temperature overnight without adverse affecting meiotic or developmental competence.

Effects of enzyme inducers and inhibitors on the pharmacokinetics of metformin in rats: involvement of CYP2C11, 2D1 and 3A1/2 for the metabolism of metformin

BACKGROUND AND PURPOSE

The types of hepatic microsomal cytochrome P450 (CYP) isozymes responsible for the metabolism of metformin in humans and rats have not been published to date. Therefore, a series of experiments using various inducers and inhibitors of CYP isozymes was conducted to find out what types of CYP isozymes are involved in the metabolism of metformin in rats.

EXPERIMENTAL APPROACH

Metformin at a dose of 100 mg kg(-1) was administered intravenously to rats. The rats were pretreated with CYP inducers such as 3-methylcholanthrene, orphenadrine, isoniazid, and dexamethasone (major inducers of CYP1A1/2, 2B1/2, 2E1, and 3A1/2, respectively, in rats), or CYP inhibitors such as SKF-525 (a non-specific inhibitor of CYP isozymes), and sulfaphenazole, quinine, and troleandomycin (major inhibitors of CYP2C11, 2D1, and 3A1/2, respectively, in rats). The time-averaged non-renal clearance (CLNR) of metformin was compared with that of controls.

KEY RESULTS

In rats pretreated with dexamethasone, the CLNR was significantly faster (57% increase) than for the controls. In rats pretreated with SKF-525-A, sulfaphenazole, quinine, and troleandomycin, the CLNR was significantly slower (24.3, 62.9, 77.6, and 78.7% decrease, respectively) than for the controls. However, the CLNR values did not significantly different in the rats pretreated with 3-methylencholanthrene, orphenadrine, and isoniazid compared with the controls.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that metformin was metabolized mainly via CYP2C11, 2D1, and 3A1/2 in rats. This result could contribute to understanding of the possible changes in metformin pharmacokinetics in disease models where CYP2C11 and/or 3A1/2 are altered.

CT colonography in a Korean population with a high residue diet: Comparison between wet and dry preparations

AIM

To compare wet and dry preparation methods for computed tomography colonography (CTC) in terms of preparation quality, interpretation time, and diagnostic performance for polyp detection in a population with a high residue diet.

MATERIALS AND METHODS

Eighty-six patients were divided into two groups. Group 1 (n=24) received a wet preparation of 4l polyethylene glycol (PEG) solution, and group 2 (n=62) received a dry preparation of phosphor-soda. Abnormal findings, including polyps, and the time required to interpret the CTC images in both groups were documented by a radiologist. CTC findings were compared to those of colonoscopy as a reference standard. Two radiologists evaluated the quality of CTC with regard to residual fluid, faeces, and colonic distension using a four-point scale in consensus. Statistical differences for residual fluid, faeces, distensibility on CTC, and interpretation time between the two groups were analysed. The diagnostic performance of CTC in both groups was also compared.

RESULTS

One-hundred and ninety polyps in 70 patients were identified using colonoscopy. Regarding the quality of images produced the wet preparation was significantly better than the dry preparation (p<0.05). The average interpretation time was significantly shorter for the wet group (11.7 min) than the dry group (16.4 min) (p<0.05). For per-patient analysis, the positive predictive value (PPV) was significantly better for the wet (100%) than the dry group (79.6%; p=0.025). Sensitivities and PPV for >or=10 mm polyps were comparable between two groups (p>0.05).

CONCLUSION

In a population with a high-residue diet, CTC with wet preparation can be interpreted in a time-efficient manner and is comparable with CTC with dry preparation.

Identification of phenylpropanoids in methyl jasmonate treated Brassica rapa leaves using two-dimensional nuclear magnetic resonance spectroscopy

Metabolic analysis showed a clear increase in phenylpropanoid levels in Brassica rapa leaves after treatment with methyl jasmonate. A fraction of phenylpropanoids was prepared by Diaion HP-20 and Sephadex LH-20 column chromatography after MeOH-water extraction. Even with these purification steps, isolation of each phenylpropanoid for structure elucidation is not easy due to the low levels in the plants (ca. 0.004%). A mixture was analyzed without further purification using HPLC-electrospray ionization mass spectrometry and NMR spectroscopy. Based on the NMR results including (1)H NMR, J-resolved, correlated spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlation (HMBC) spectra, both (1)H and (13)C resonances of the compounds were obtained. Using these NMR data, five phenylpropanoids conjugated with malate were identified: 5-hydroxyferuloyl-, caffeoyl-, coumaroyl-, feruloyl-, and sinapoyl malate. Of the compounds, 5-hydroxyferuloyl malate is a new phenylpropanoid. In addition to the five constitutive phenylpropanoids bearing trans-configuration, their cis forms, which are believed to be artifacts formed in the course of extraction steps, were also identified in the fraction.

Blastocyst development in equine oocytes with low meiotic competence after suppression of meiosis with roscovitine prior to in vitro maturation

This study was conducted to evaluate the in vitro development of equine oocytes with compact cumuli that had been subjected to a period of meiotic suppression with roscovitine before in vitro maturation. In experiment 1, oocytes were recovered from slaughterhouse-derived ovaries and held in M199 + 10% fetal bovine serum containing 66 μM roscovitine with or without an overlay of mineral oil in 5% CO2 in air at 38.2 °C for 16–18 or 24 h. No oocytes treated with roscovitine in the absence of an oil overlay for 16–18 h were maturing, compared with 2–4% of oocytes in other treatments. In experiment 2, oocytes were either fixed immediately after recovery, or were cultured for 18 h in the presence or absence of roscovitine. Oocytes cultured in the absence of roscovitine had a significantly higher rate of meiotic resumption (18%) than was found in the other two treatments (0). In experiment 3, oocytes were matured immediately or after 16–18 h culture with roscovitine. Maturation rates were similar between oocytes previously treated with roscovitine (22%) and control oocytes (19%). Mature oocytes were fertilized by intracytoplasmic sperm injection and then cultured, with or without oviductal epithelial cells, for 7.5 days. There was no significant effect of roscovitine treatment on blastocyst development. Development to blastocyst of roscovitine-treated oocytes in DMEM/F-12 + co-culture (37%) was significantly higher than that of control oocytes in DMEM/F-12 without co-culture (14%). These data indicate that equine oocytes with compact cumuli can be held in roscovitine before maturation without any harmful effect on blastocyst formation.

beta-lapachone induces growth inhibition and apoptosis in bladder cancer cells by modulation of Bcl-2 family and activation of caspases

AIM

To study in vitro the molecular mechanism of apoptosis caused by beta-lapachone, a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae).

MATERIALS AND METHODS

The study was carried out on human bladder carcinoma T24 cell line. Determination of cell viability was done using trypan blue exclusion method, apoptosis quantitative estimation - by DAPI staining and agarose gel electrophoresis for DNA fragmentation. Flow cytometry analysis, RT-PCR and Western blot analysis, colorimetric assay of caspase activity were applied as well.

RESULTS

It was found that in micromolar range of concentrations beta-lapachone inhibited the viability of T24 cells by inducing apoptosis, which could be proved by formation of apoptotic bodies and DNA fragmentation. Treatment of T24 cells with beta-lapachone resulted in a down-regulation of Bcl-2 expression and up-regulation of Bax expression. beta-lapachone-induced apoptosis was also associated with activation of caspase-3 and caspase-9, inhibition of IAP expression, and degradation of poly (ADP-ribose) polymerase, phospholipase C-gamma1 and beta-catenin proteins. At the same time Fas and FasL levels were inhibited upon treatment with beta-lapachone in a concentration-dependent manner.

CONCLUSION

beta-lapachone-induced apoptosis in T24 cells is mediated, at least in part, by the mitochondrial-signaling pathway.

Equine blastocyst development after intracytoplasmic injection of sperm subjected to two freeze-thaw cycles

This study was conducted to evaluate the effects of thawing, division into aliquots and refreezing on fertilizing capacity (ability to support embryo development after intracytoplasmic sperm injection; ICSI) of frozen stallion semen. Frozen semen from a fertile stallion was thawed, diluted 1:100 with freezing extender, and refrozen (2F treatment). Control semen was frozen only once. In vitro matured equine oocytes were injected with: (1) motile control spermatozoa; (2) motile 2F spermatozoa; (3) non-motile 2F spermatozoa; or (4) non-motile 2F spermatozoa, followed by injection of sperm extract. Blastocyst development after ICSI was equivalent between control spermatozoa and motile 2F spermatozoa (27 and 23%, respectively). Blastocyst development after injection of non-motile 2F spermatozoa (13%) tended (P=0.07) to be lower than that for control spermatozoa. Injection of sperm extract into oocytes that received non-motile 2F spermatozoa resulted in a significant decrease in blastocyst development (to 2%) compared with injection of non-motile 2F spermatozoa alone. Spermatozoa from a subfertile stallion was similarly processed and used for ICSI; blastocyst development for both motile control (once frozen) spermatozoa and motile 2F spermatozoa was 9%. In conclusion, frozen stallion semen may be thawed, diluted, and refrozen without effect on the ability of motile spermatozoa to initiate embryo development after ICSI. Non-motile spermatozoa from reprocessed semen may also achieve embryo development after ICSI. To our knowledge, this is the first report evaluating the ability of refrozen spermatozoa to produce embryos by ICSI in any species.

Effect of closed minimized cardiopulmonary bypass on cerebral tissue oxygenation and microembolization

OBJECTIVE

Coronary artery bypass grafting with cardiopulmonary bypass carries a risk for neurologic complications because of cerebral hypoperfusion and microembolization. The basic goals of a novel closed minimized extracorporeal circulation are to prevent excessive hemodilution and to avoid blood-air interface. The aim of this prospective randomized study was to determine the effect of using the minimized extracorporeal circulation system compared with open conventional extracorporeal circulation on cerebral tissue oxygenation and microembolization.

METHODS

Forty patients undergoing coronary artery bypass grafting (20 in each group) were continuously monitored for changes in cerebral oxygenated hemoglobin and tissue oxygenation index by using near-infrared spectroscopy. Total microembolic count and gaseous embolic count in both median cerebral arteries were monitored with multifrequency transcranial Doppler instrumentation.

RESULTS

In the conventional extracorporeal circulation group there was a highly significant reduction in both cerebral oxygenated hemoglobin and tissue oxygenation index from the start to the end of cardiopulmonary bypass (P < .01). The rate of decrease in cerebral oxygenated hemoglobin after aortic cannulation was faster in the conventional extracorporeal circulation group (F test = 9.03, P < .001). No significant changes with respect to cerebral oxygenated hemoglobin or tissue oxygenation index occurred in the minimized extracorporeal circulation group, except at the beginning of rewarming (P < .01). Total embolic count, as well as gaseous embolic count, in the left and right median cerebral arteries was significantly lower in the minimized extracorporeal circulation group (all P < .05). Postoperative bleeding was greater (P < .05) and the transfusion rate was higher (P < .05) in the conventional extracorporeal circulation group.

CONCLUSIONS

Use of closed minimized cardiopulmonary bypass compared with conventional open cardiopulmonary bypass preserves cerebral tissue oxygenation and reduces cerebral microembolization.

29 BIRTH OF A FOAL CLONED BY ADULT SOMATIC CELL NUCLEAR TRANSFER WITH ROSCOVITINE-TREATED DONOR CELLS

Only one horse foal produced from adult somatic cell nuclear transfer has been reported in the scientific literature (Galli et al. 2003 Nature 425, 680); a second foal from the same laboratory was reported in the popular press in 2005. In these reports, the blastocyst rates were 3 and 17%, and efficiency to birth of a live foal from total reconstructed oocytes was 0.1 and 0.5%, respectively. In cattle, roscovitine treatment of donor cells has been associated with a decrease in blastocyst development, but an increase in live births (Gibbons et al. 2002 Biol. Reprod. 66, 895-900). The present study was performed to determine the effect of roscovitine treatment of donor cells on blastocyst production after equine nuclear transfer and to evaluate the viability of pregnancies established via this treatment. In Experiment 1, fibroblasts were either grown to confluence or treated with 15 �g/mL roscovitine, for 24 h. Enucleated in vitro-matured oocytes were reconstructed by direct injection of fibroblasts using a piezo drill. Recombined oocytes were activated by injection of stallion sperm extract, followed by culture in the presence of 2 mM 6-DMAP for 4 h. They were then placed in culture in DMEM/F-12 with 10% fetal bovine serum (FBS) under mixed gas for 8 days and evaluated for blastocyst development. In Experiment 2, oocytes recombined with either confluent or roscovitine-treated donor cells were activated as above either alone or with the addition of 10 �g/mL cycloheximide at the time of 6-DMAP treatment. Resulting blastocysts from Experiment 2 were transferred transcervically to the uteri of recipient mares. One embryo was transferred per mare. In Experiment 1, there was no difference in rates of cleavage (73-19%) or blastocyst development between confluence and roscovitine treatments (2/55, 3.6% vs. 2/56, 3.6%, respectively). In Experiment 2, there was no significant difference in rates of cleavage (78-18%) or blastocyst development (0-1%; 4/105, 0/104, 0/106, 2/108) among donor cell or activation treatments. Six blastocysts were transferred to mares: two from confluent donor cells and four from roscovitine-treated donor cells. One mare, which received an embryo from the roscovitine donor/6-DMAP treatment, established pregnancy after transfer. The pregnancy continued normally and the mare delivered a colt with minimal assistance on Day 389. Typing for 13 equine microsatellites confirmed that the colt was of the same DNA type as the donor fibroblasts. The colt has grown and developed normally. Results of these studies show that roscovitine treatment of equine donor cells does not negatively affect the proportion of recombined oocytes that progress to the blastocyst stage. A viable colt resulted from an embryo produced with roscovitine-treated donor cells. More work is needed on methods to increase blastocyst rates after nuclear transfer in this species. This work was supported by the Link Equine Research Endowment Fund, Texas A&M University.

Effects of flocculent aggregates on microfiltration with coagulation pretreatment of high turbidity waters

Immersed membrane systems, and those with in-line coagulation, have been extensively applied in drinking water systems. Sedimentation is usually replaced by membrane processes in both systems. In these systems, voluminous flocculent aggregates formed during coagulation could be potential foulants. When raw waters with high turbidity are introduced, particle loadings to membrane due to coagulation pretreatment are enormous and thus could increase fouling. In general, during the rainy season, the turbidity of the Han River water, which supplies drinking water for the City of Seoul, Korea, is more than a hundred times higher than usual. Therefore, effects of floc on membrane fouling were investigated with highly turbid waters. Two turbidity concentrations, 40 and 200 NTU, were formulated by the addition of kaolin (used as a natural particle surrogate) to the Han River raw water. The results showed that the flux decline behaviours of the highly turbid waters were different from those of natural raw water. Coagulation pretreatment was very effective at reducing membrane fouling. Flocculent aggregates showed a negative effect on the flux decline but a positive effect on the membrane cleaning efficiency.