Superconducting properties of the Fe-based layered superconductor LaFeAsO0.9F0.1-delta

We have employed a new route to synthesize single phase F-doped LaOFeAs compound and confirmed the superconductivity above 20 K in this Fe-based system. We show that the new superconductor has a rather high upper critical field of over 50 T. A clear signature of superconducting gap opening below T(c) was observed in the far-infrared reflectance spectra, with 2Delta/kT(c) approximately 3.5-4.2. Furthermore, we show that the new superconductor has electron-type conducting carriers with a rather low-carrier density.

Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO1-xFxFeAs

A series of layered CeO1-xFxFeAs compounds with x=0 to 0.20 are synthesized by the solid state reaction method. Similar to the LaOFeAs, the pure CeOFeAs shows a strong resistivity anomaly near 145 K, which was ascribed to the spin-density-wave instability. F doping suppresses this instability and leads to the superconducting ground state. Most surprisingly, the superconducting transition temperature could reach as high as 41 K. Such a high T_{c} strongly challenges the classic BCS theory based on the electron-phonon interaction. The closeness of the superconducting phase to the spin-density-wave instability suggests that the magnetic fluctuation plays a key role in the superconducting pairing mechanism. The study also reveals that the Ce 4f electrons form local moments and are ordered antiferromagnetically below 4 K, which could coexist with superconductivity.

A comparative study of hFIX expression mediated by rAAV8 and rAAV1 administrated intramuscularly

BACKGROUND

Recombinant AAV serotype 8 (rAAV8) vector is relatively new for gene therapy. In this study, the hFIX expression mediated by rAAV8 injected intramuscularly was compared with that by rAAV1.

METHODS

rAAV8-hFIX or rAAV1-hFIX viruses were injected intramuscularly into two hind limbs of mice at doses of 5x10(10) gc and 2.5x10(12) gc (genome copy). The hFIX expression in the mouse plasma was detected by ELISA, APTT and Western blotting. The virus distribution was analyzed by immunohistochemical assay.

RESULTS

When the mice were infected with 5x10(10) gc virus, high levels of hFIX in the plasma of five rAAV8-hFIX virus-infected mice were detected 2 weeks after injection. A hFIX peak above 5000 ng/mL appeared between 2 and 6 weeks after injection. Relatively low levels of hFIX were detected in the plasma of rAAV1-hFIX virus-infected mice 2 weeks after injection. An hFIX peak above 3000 ng/mL appeared between 4 and 10 weeks after injection. However, much lower levels of hFIX were detected in mice infected with higher dose of rAAV8 virus. The hFIX in the mouse plasma was active biologically. The viruses were distributed mainly in the muscles of hind limbs.

DISCUSSION

Gene expression mediated by rAAV8 was sooner and stronger than that by rAAV1 after intramuscular administration. Inhibition might have been triggered markedly by rAAV8 at high doses.

Raloxifene acutely reduces glutamate-induced intracellular calcium increase in cultured rat cortical neurons via inhibition of high-voltage-activated calcium current

There is increasing evidence indicating that estrogen replacement therapy produces neuroprotective actions but has undesirable side effects on the reproductive system. Raloxifene is a selective estrogen receptor modulator that exerts estrogen agonist action in the brain while acting as an estrogen antagonist in the reproductive system. In the present study, we investigated whether raloxifene affected the glutamate-induced calcium (Ca2+) overload in rat cultured cortical neurons. The bulk cytosolic intracellular Ca2+ level was measured by using confocal microscopy with fluorescent Ca2+ probe fluo3. Whole-cell recording technique was used to observe the effects of raloxifene on N-methyl-D-aspartate (NMDA)-evoked and voltage-activated Ca2+ currents in cultured cortical neurons. Pre-exposure of cortical neurons to raloxifene (0.5 microM-10 microM) for 3 min attenuated intracellular Ca2+ increase induced by application of glutamate (300 microM) for 1 min. The action of raloxifene was reversible after washout. ICI 182,780 and thapsigargin did not block the action of raloxifene. In whole-cell recording experiments, raloxifene (10 microM) significantly reduced the amplitude of the high-voltage-activated Ca2+ current but had no effect on NMDA-evoked Ca2+ current. The present study demonstrates that raloxifene acutely reduces glutamate-induced intracellular Ca2+ increase probably via inhibition of high-voltage-activated calcium channels.

Effects of in vitro maturation of monkey oocytes on their developmental capacity

The study of in vitro maturation (IVM) of rhesus monkey oocytes has important implications for biomedical research and human infertility treatment. In vitro-matured rhesus monkey oocytes show much less developmental potential than IVM oocytes of other species. Since about 1980 when rhesus monkey IVM, in vitro fertilization (IVF) and in vitro embryo culture (IVC) systems were established, numerous efforts have been made to improve the developmental competence of oocytes and to understand the mechanisms regulating oocyte maturation. This review describes recent progress in this area, particularly the effects of factors such as steroid hormones, energy substrates, amino acids, ovarian follicle status, maternal age and breeding season on the developmental competence, gene expression patterns and genome integrity of rhesus IVM oocytes.

CD62L is required for the priming of encephalitogenic T cells but does not play a major role in the effector phase of experimental autoimmune encephalomyelitis

CD62L (l-selectin, mel 14) regulates naïve T cell homing into lymph nodes and the migration of leucocytes to sites of inflammation. The requirement of CD62L in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, has been demonstrated previously. However, it remains controversial as to whether CD62L is required for the induction or the effector phase of EAE. It is also unclear whether other non-T effector cells need CD62L to enter the central nervous system (CNS) parenchyma and exert their damaging effects on myelin. We report that mice with a targeted mutation of CD62L are resistant to Myelin oligodendrocyte glycoprotein peptide-induced EAE. CD62L-deficient mice had no peptide-specific T cell responses in the draining lymph nodes and had lower levels of peptide-specific T cell responses in spleens at a later time point. Adoptive transfer studies showed that CD62L-deficient mice were fully susceptible to adoptive transfer EAE induced by either wildtype or CD62L-deficient T cells. Moreover, CD62L-deficient, F4/80(+) macrophages can be efficiently recruited into the CNS parenchyma. These data suggest that CD62L is required for the induction of encephalitogenic T cells during EAE development, but is not required by T and non-T effector cells to attack the CNS parenchyma.

Neurosteroid enhances glutamate release in rat prelimbic cortex via activation of alpha1-adrenergic and sigma1 receptors

The present paper studied the effect and mechanism of neurosteroid pregnenolone sulfate (PREGS) on spontaneous glutamate release using electrophysiological and biochemical methods combined with a pharmacological approach. The results suggested that PREGS had a selective enhancing effect on spontaneous glutamate release in the prelimbic cortex and the hippocampus but not in the striatum. The effect of PREGS in the prelimbic cortex appeared to be via modulation of alpha1-adrenergic and sigma1 receptors, but in the hippocampus it might be dependent on sigma1 receptors only. The activation of alpha1-adrenergic receptors synergized sigma1 receptor activation in the prelimbic cortex. Intracellular calcium released from the endoplasmic reticulum, protein kinase C, adenylyl cyclase and protein kinase A played a key role in the effect of PREGS. Intracellular calcium, protein kinase C and adenylyl cyclase might be upstream events in the activation of protein kinase A after PREGS.

Infrared probe of the electronic structure and charge dynamics of Na0.7CoO2

We present measurements of the optical spectra on Na(0.7)CoO(2) single crystals. The optical conductivity shows two broad interband transition peaks at 1.6 eV and 3.1 eV, and a weak midinfrared peak at 0.4 eV. The intraband response of conducting carriers is different from that of a simple Drude metal. A peak at low but finite frequency is observed, which shifts to higher frequencies with increasing temperature, even though the dc resistivity is metallic. The origin of the interband transitions and the low-frequency charge dynamics have been discussed and compared with other experiments.

95FIRST REPORT ON CLEAVAGE DEVELOPMENT FOLLOWING CRYOPRESERVATION OF ADULT AND PREPUBERTAL RHESUS MONKEY (MACACA MULATTA) OOCYTES

Cryopreservation of non-human primate oocytes would allow a more efficient management of biological resources for medical research and endangered species preservation. Despite previous attempts, no cleavage-stage development has been reported following cryopreservation of rhesus monkey (Macaca mulatta) or other non-human primate oocytes. The extreme chilling sensitivity of rhesus monkey oocytes (Songsasen N et al., 2002 Fertil. Steril. 77, 818–825) might be overcomed by vitrification methods. Our aim was to test the Solid Surface Vitrification (SSV, Dinnyes A et al., 2000 Biol. Reprod. 63, 513–518) method on metaphase II (MII)-stage rhesus monkey oocytes and to achieve successful fertilization of warmed oocytes. Oocytes were obtained from hormonally stimulated adult and unstimulated prepubertal females and matured in vitro for 36 to 48h as described by Zhang P et al. (2001 Biol. Reprod. 64, 1417–1421). The vitrification solution contained 35% ethylene glycol (EG), 5% polyvinyl pyrrolidone, and 0.4M trehalose in Tyrode-lactate (TL)-HEPES medium with 3mgmL−1 BSA added. Oocytes at MII-stage were equilibrated in 4% EG in TL-HEPES at 37°C for 10 to 12min and then exposed to the vitrification solution at 37°C for about 20s. Oocytes in 2-μL droplets of vitrification solution were dropped onto a metal surface at about −180°C where they were vitrified instantaneously. Warming was performed by moving the vitrified droplets into 0.3M trehalose at 37°C. Recovered oocytes were exposed to 0.15M and then 0.075M trehalose for 2min each and then rinsed three times in TL-HEPES. Warmed oocytes were fertilized in vitro and then cultured for 96h in 50-μL drops of mCMRL-1066 containing 20% FCS at 37°C in a humidified atmosphere of 5% CO2, 5% O2, and 90% N2, as described in details by Zhang (see above). A total of 21 MII oocytes were collected from 2 adult and 55 MII oocytes from 14 prepubertal animals. No difference has been found between the rate of adult-origin (15/19; 79%) v. prepubertal-origin (37/52; 71%) oocytes surviving the vitrification process without lysis (P>0.05, chi-square analyses). Following subsequent IVF, 1/15 (7%) adult-origin and 4/23 (17%) prepubertal-origin oocytes cleaved further, which was lower than that of the corresponding controls (1/2 (50%) and 1/3 (33%), respectively). The furthest development observed following cryopreservation was 16-cell stage, verified by counting of stained nuclei. This is the first report on cleavage-stage development of cryopreserved rhesus monkey oocytes, demonstrating the feasibility of vitrification and the potential for gene banking of non-human primate oocytes, even from prepubertal animals. Further experiments are needed to achieve higher rates of cryosurvival and progeny development. This research was supported by a Chinese-Hungarian Bilateral Technological and Scientific Collaboration Project (No. CHN14/02).

Vascular endothelial growth factor inhibits outward delayed-rectifier potassium currents in acutely isolated hippocampal neurons

In the present study, whole-cell patch-clamp recording was used to study whether vascular endothelial growth factor (VEGF) had a regulatory effect on the potassium-channel currents. The outward delayed-rectifier potassium currents (I(K)) were recorded in acutely isolated hippocampal neurons from 14-day-old rat brains. A local application of VEGF at the concentrations from 50 ng/ml to 200 ng/ml dose-dependently inhibited I(K). Administration of VEGF (100 ng/ml) to the neurons only for seconds could significantly reduce I(K) in 26 of 39 recorded cells. The currents could recover to 82.8+/-3.7% of the control level at 60 s after removing VEGF in the buffer. In the I-V curve analysis, VEGF negatively shifted the I-V curve of I(K); the inhibition was gradually enhanced as the membrane potential increased from -40 mV to 50 mV in 13 cells. Thus, the results reveal that VEGF inhibits I(K) in acute, reversible and voltage-dependent manners. Double staining combined with confocal laser scanning microscopy was used to simultaneously detect the distribution of VEGF receptors (flt-1 and flk-1) in the hippocampal section and isolated neuron. Results showed that flt-1-positive staining, but not flk-1, could be observed on the membrane of the hippocampal neuron in both preparations, suggesting the presence of neuronal membrane VEGF flt-1 receptors in the hippocampus. To investigate if the inhibition by VEGF on I(K) is related to the presence of flt-1 receptors, we further did flt-1-receptor immunostaining for the recorded neurons, which was labeled with Lucifer Yellow during the recording. Among nine recorded cells, five showing the inhibition by VEGF had detectable signals for flt-1 receptors on their membrane, whereas the other four showing no inhibition had no flt-1 receptors either. The results suggest that VEGF can acutely inhibit I(K) in the hippocampal neurons probably related to the presence of membrane flt-1 receptors in the neurons.

Amino acid requirements for maturation of rhesus monkey (Macacca mulatta) oocytes in culture

This study evaluated the effects of different amino acid formulations on supporting meiotic and cytoplasmic maturation of rhesus monkey (Macacca mulatta) oocytes in vitro. Five hundred and forty-six cumulus-oocyte complexes (COCs) aspirated from unstimulated adult monkey follicles (> or = 1000 microm in diameter) were cultured in either modified Connaught Medical Research Laboratories 1066 medium (mCMRL-1066) or in one of eight chemically defined media (modified basic medium 5 supplemented with 5.5 mmol glucose l(-1), 0.003 mmol pantothenic acid l(-1) and different amino acid formulations) as below: (1) modified basic medium 5 (mBM5) containing no amino acid; (2) mBM5 + 0.2 mmol glutamine l(-1); (3) mBM5 + 11 amino acids from hamster embryo culture medium 6 (HECM-6) (11 AA); (4) mBM5 + Eagle's non-essential amino acids (NEA); (5) mBM5 + NEA + 0.2 mmol glutamine l(-1); (6) mBM5 + Eagle's essential amino acids (EA) without glutamine; (7) mBM5 + EA + 0.2 mmol glutamine l(-1); (8) mBM5 + Eagle's 20 amino acids (20 AA) + 0.2 mmol glutamine l(-1); and (9) mCMRL-1066 (control). All media contained FSH, LH, oestradiol and progesterone. After maturation, mature oocytes were subjected to the same fertilization and embryo culture procedures. COCs matured in treatment 5 had greater potential to progress to metaphase II (66%; P < 0.05) than did those in treatments 1 (37.3%), 2 (48.3%), 3 (41%), 6 (41%) and 9 (43%). Oocytes matured in treatment 8 had the best morula (53%) and blastocyst (18%) developmental responses (P < 0.05). The lowest (P < 0.05) morula and blastocyst developmental responses were obtained from COCs matured in treatments 1 (0%) and 6 (8%). The other media supported intermediate embryonic development (range 11-38% of morula and blastocyst). These results indicate that the choice of amino acids affects the competence of oocyte maturation and that Eagle's 20 AA with 0.2 mmol glutamine l(-1) is more efficient than the other amino acid formulations for maturation of rhesus monkey oocytes.

Activation of presynaptic D1 dopamine receptors by dopamine increases the frequency of spontaneous excitatory postsynaptic currents through protein kinase A and protein kinase C in pyramidal cells of rat prelimbic cortex

To determine the effect of dopamine on the frequency of spontaneous excitatory postsynaptic currents (EPSCs) in pyramidal cells of layers V-VI of the prelimbic cortex, whole-cell patch-clamp recordings were made from 92 pyramidal cells of layers V-VI of the rat prelimbic cortex. In normal buffer, dopamine 100 microM apparently increased the frequency of spontaneous EPSCs. Decreasing the concentration of dopamine from 100 to 50 microM was accompanied by a decreased effect of dopamine. Further decreasing the dopamine concentration to 10 and 1 microM had no effects on the frequency of spontaneous EPSCs. In the presence of tetrodotoxin or cadmium, the increasing effect of dopamine was eliminated. The increasing effect of dopamine was blocked by the dopamine D1 receptor antagonist SCH23390, but not by the dopamine D2 receptor antagonist sulpiride. The D1 receptor agonist SKF38393 partially mimicked the increasing effect, but the D2 receptor agonist quinpirole did not. The alpha(1)-adrenoceptor antagonist prazosin could not block the increasing effect of dopamine on the frequency of spontaneous EPSCs in most cells tested. The protein kinase A inhibitor H-89 and the protein kinase C inhibitor chelerythrine could antagonize the effect of dopamine. The protein kinase A activator forskolin and the protein kinase C activator phorbol 12,13-dibutyrate could mimic the effect of dopamine. These results indicate that dopamine, presynaptically acting on dopamine D1 receptors, increases the frequency of spontaneous EPSCs via intracellular protein kinase A and protein kinase C signaling pathways in pyramidal cells of layers V-VI of the prelimbic cortex.

Genetic aberrations in gliomatosis cerebri support monoclonal tumorigenesis

Gliomatosis cerebri is a rare condition in which the brain is infiltrated by an exceptionally diffusely growing glial cell population involving at least 2 lobes, though often more extensive, sometimes even affecting infratentorial regions. The neoplastic proliferation may have a monoclonal origin, or alternatively, reflect progressive neoplastic change of an entire tissue field ("field cancerization"). The presence of an identical set of genetic aberrations throughout the lesion would point to monoclonality of the proliferation. In contrast, the finding of non-identical genetic changes in widely separated regions within the neoplasm would support the concept of field cancerization. In the present study, a unique autopsy case of gliomatosis was available to verify either one of these hypotheses. Tissue samples were randomly taken from 24 locations throughout the brain and used for genetic investigation. In all samples the histology showed an identical picture of slightly elongated astrocytic cells, typical for gliomatosis. TP53 exon 5-8 mutation analysis was performed on all samples. Genome-wide screening for chromosomal aberrations was accomplished by comparative genomic hybridization (CGH). In addition, loss of heterozygosity analysis for polymorphic markers on chromosomal regions of the 2 most frequently observed DNA deletions was carried out. The most widespread genetic aberration was mutation of exon 7 of TP53, which was detected in 20 of 24 samples. Bidirectional sequencing revealed a mutation in codon 234 (TAC234TGC), resulting in an amino acid substitution Tyr-Cys. CGH analysis revealed losses on 2q11-q31 in 13 of 24 samples and losses on 19q13-qter in 10 of 24 samples from both left and right hemispheres. Allelic imbalances for markers on 2q (2q14.3 and 2q22.1) and 19q (both 19q13.2) were demonstrated in 10 of 24 and 18 of 24 samples, respectively. Other widespread chromosomal aberrations included losses on 3q13-qter and 16q22-qter and gains on 7q22-qter. The wide distribution of a particular set of genetic aberrations in this case supports the concept of monoclonal tumor proliferation. The results point to involvement of TP53 mutation in the tumorigenesis of gliomatosis cerebri.

Is tumor expression of the major histocompatibility complex antigen required for T cell immune surveillance?

Tumor expression of major histocompatibility complex antigen (MHC) class I and class II is not essential for the induction of memory T cells. However, induction of MHC class I-restricted effector cytotoxic T cells (CTL) appears dependent on MHC class I expression on tumors. Moreover, the effector function of tumor-specific CTL requires direct recognition of the tumor. In contrast, both the inductive and the effector phases of MHC class II-restricted T cells are independent of MHC class II expression on tumors.

Stably transfected ABCA1 antisense cell line has decreased ABCA1 mRNA and cAMP-induced cholesterol efflux to apolipoprotein AI and HDL

Using a sensitive real time fluorescent PCR assay, ABCA1 mRNA levels were induced by approximately 50-70-fold following 8Br-cAMP treatment of the RAW264 murine macrophage cell line, concomitant with the induction of cholesterol efflux to apoAI and HDL. A stably transfected ABCA1 antisense cDNA cell line was created, which led to approximately 50-70% reductions in ABCA1 mRNA levels in basal and 8Br-cAMP-treated cells, and diminished to the same extent the 8Br-cAMP-mediated efflux of cholesterol to apolipoprotein AI and HDL. These data demonstrate that ABCA1 is necessary for the cAMP-induced lipid efflux to both apoAI and HDL.

B7H costimulates clonal expansion of, and cognate destruction of tumor cells by, CD8(+) T lymphocytes in vivo

B7H/B7RP (hereby called B7H) is a new member of the B7 family of costimulatory molecules and interacts with inducible costimulatory molecule (ICOS). Its function for CD8 T cells has not been reported. We report here that expression of B7H on the tumor cells reduced tumorigenicity and induced immunity to subsequent challenge with parental tumor cells. The immune protection correlates with an enhanced cytotoxic T lymphocyte (CTL) response against P1A, the major tumor antigen expressed in the J558 tumor. To understand the mechanism of immune protection, we adoptively transferred transgenic T cells specific for tumor antigen P1A into mice that bore P1A-expressing tumors. We found that while the transgenic T cells divided faster in mice bearing the B7H(+) tumors, optimal B7H-induced clonal expansion of P1CTL required costimulation by B7-1 and B7-2 on the endogenous host antigen-presenting cells (APCs). Interestingly, when B7H(+) and B7H(-) tumors were coinjected, P1CTL selectively eliminated the B7H(+) tumor cells. Moreover, B7H expressed on the tumor cells made them highly susceptible to destruction by CTL in vivo, even if the CTL was administrated into mice with large tumor burdens. Tumors that recurred in the P1CTL-treated mice lost transfected B7H and/or H-2L(d), the class I molecule that presents the P1A peptide. Taken together, our results reveal that B7H costimulates clonal expansion of, and cognate destruction by CD8(+) T lymphocytes in vivo.

Local costimulation reinvigorates tumor-specific cytolytic T lymphocytes for experimental therapy in mice with large tumor burdens

Cytotoxic T cells recognize tumor Ags and destroy cancer cells in vitro. Adoptive transfer studies with transgenic T cells specific for tumor Ags have demonstrated that CTL are effective only in mice with small tumor burdens and thus appear to have limited potential in cancer immunotherapy. Here we used transgenic mice that express the TCR specific for an unmutated tumor Ag P1A and multiple lineages of P1A-expressing tumors to address this critical issue. We found that local costimulation, either by expression of B7-1 on the tumor cells or by local administration of anti-CD28 mAb 37N, reinvigorated the function of CTL specific for the tumor Ag, as it substantially increased the efficacy of CTL therapy for mice with large tumor burdens. Our study suggests that CTL-based immunotherapy can be manipulated to deal with large tumors.

On the site and mode of antigen presentation for the initiation of clonal expansion of CD8 T cells specific for a natural tumor antigen

Because of the low frequency of antigen-specific T cells, early events in the activation of tumor-specific T cells in vivo have not been well characterized. There is still no direct documentation on where the clonal expansion begins and how tumor antigens are presented to the host CD8 T cells to initiate it. Here we used transgenic T cells specific for a natural tumor antigen P1A to evaluate the kinetics, location, and modes of antigen presentation for initiating CTL response in vivo. Our results demonstrate that the initial activation of P1A-specific T cells takes place in the lymphoid organs. The activated T cells then migrate into tumors, where they undergo accelerated division and acquire distinct activation markers. The site of initiation cannot be altered by either local expression of costimulatory molecules or by intratumor injection of naïve T cells. Moreover, using genetic models that allow only one mode of antigen presentation, we show here that both cross-presentation of P1A by the host antigen-presenting cells, and direct antigen presentation and costimulation by the tumor cells are sufficient to initiate rapid T cell-clonal expansion in the lymphoid organ. These results provide direct evidence for two fundamental assumptions on the mechanisms of T-cell activation in vivo.

[A lumped parameter model of the peripheral extra-corporeal circulation]

A three-element model of lumped parameter in peripheral extra-corporeal circulation of an animal has been proposed and set up according to the fluid network theory. GEAR method, appropriate for the computation of the rigid problems, was used to solve the ordinary differential equations, so that a good convergence of the solution to the equations has been achieved. Physiological data of a 20 kg dog, obtained from our animal experiments were used to calculate the pressure and flow rate of important organs. The results of the mathematical model and animal tests showed that the peripheral extra-corporeal circulation could supply enough blood to the important organs, e.g. heart and brain, when the natural heart beating stopped. The results from both theoretical and experiments are critical to the cardiopulmonary cerebral resuscitation for the animals as well as for human beings.

Characterization of spontaneous excitatory synaptic currents in pyramidal cells of rat prelimbic cortex

Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded with the whole-cell patch-clamp technique from 41 pyramidal cells in the layers V-VI of the prelimbic (PL) cortex. The sEPSCs occurred randomly and the averaged frequency in 41 cells was 1.81+/-0.27 Hz. The amplitude distribution was skewed toward larger events and could be adequately fitted by a sum of two or three Gaussian distributions, but they could not be fitted by a sum of Gaussian distributions with equidistant separation in all cells studied (n=24). In eight of 24 cells, after the transformation of the amplitudes into logarithms, the skewed histogram became bell-shaped and could be adequately fitted by a single Gaussian distribution, whereas in the other 16 cells, after the transformation the histograms were still skewed. However, for those latter cells, when the logarithms were transformed into difference, the distribution of the differences in 15 of 16 cells became bell-shaped and could be adequately fitted by a single Gaussian distribution. The pie distribution of different rise times within one cell in 1 ms bin showed that there were four different patterns of the rise time distribution. The amplitude distribution of the sEPSCs was unchanged in 10 of 22 cells after TTX, but in the other 12 cells, it was changed significantly. However, for these cells although TTX had a marked effect, it could not change the skewed distribution into a single Gaussian distribution in case of both original and transformed data.

Effect of age and breeding season on the developmental capacity of oocytes from unstimulated and follicle-stimulating hormone-stimulated rhesus monkeys

Effects of age and season on the developmental capacity of oocytes from unstimulated and FSH-stimulated rhesus monkeys were examined. Immature cumulus-oocyte complexes were matured in vitro in modified CMRL-1066 medium containing 20% bovine calf serum and subjected to in vitro fertilization followed by embryo culture. After fertilization, ova from unstimulated prepubertal monkeys displayed lower development to morula (4%) than those from unstimulated adult females (18% in breeding season and 22% in nonbreeding season). No developmental difference was found between ova from unstimulated adult monkeys in breeding and nonbreeding seasons. However, ova from FSH-primed prepubertal monkeys displayed greater development to blastocyst stage (54%) than those from adult monkeys in the breeding season (16%) and nonbreeding season (0%); and ova from FSH-primed adult females in the breeding season had significantly (P < 0.05) greater developmental competence than those obtained in the nonbreeding season (> or = morula stage, 54% vs. 3%; blastocyst stage, 16% vs. 0%). These data indicate that 1) rhesus monkey oocytes acquire developmental competence in a donor age-dependent manner, and 2) animal age and breeding season modulate the effect of FSH on oocyte developmental competence in the rhesus monkey.