Bovine oocytes from early antral follicles grow to meiotic competence in vitro: effect of FSH and hypoxanthine

A large number of oocytes are contained in the mammalian ovary. A very small number of these oocytes grow to the final size, mature, and are ovulated. In the ovary there are more early antral follicles than late antral or preovulatory follicles, offering a large pool of oocytes for IVM and IVF if appropriate culture conditions could be devised. In the present study, early antral follicles containing oocytes 90 to 99 microm in diameter were isolated from bovine ovaries. Cumulus-oocyte complexes (COC) with pieces of parietal granulosa (COCG) were then dissected from the follicles. The COCGs were embedded in collagen gels and cultured in Medium 199 with 10% fetal calf serum (FCS) for 8 d. In Experiment 1, the effect of hypoxanthine and FSH on the growth of bovine oocytes was examined. When hypoxanthine (2 and 4 mM) and FSH (10 ng/ml) were added to the culture medium, the number of granulosa cell-enclosed oocytes increased significantly (P < 0.05). All of the oocytes surrounded by granulosa cells showed a normal morphology and were at the germinal vesicle stage, while 75 to 94% of the denuded oocytes were degenerated and had resumed meiosis. The mean diameter of the oocytes showing normal morphology was significantly higher than that measured before culture (P < 0.05). In Experiment 2, the maturational competence of in vitro-grown bovine oocytes was examined. Oocytes which were 90 to 99 microm in diameter before culture did not have meiotic competence. After being in a growth culture of 4 mM hypoxanthine- and 10 ng/ml FSH-supplemented medium for 7 or 11 d, granulosa cell-enclosed oocytes were recovered from the COCGs. No significant difference (P < 0.05) in the diameters of the oocytes was observed between 7 and 11 d of culture (7 d: 107.5 +/- 6.1 microm, n = 30; 11 d: 108.0 +/- 5.3 microm, n = 35). After a subsequent 24 h in a maturation free of hypoxanthine and FSH medium, only 17% of the oocytes cultured for 7 d underwent germinal vesicle breakdown. On the other hand, 89% of the oocytes cultured for 11 d underwent germinal vesicle breakdown, and 11% of the oocytes emitted the first polar body and reached metaphase II. These results demonstrate for the first time that bovine oocytes harvested from early antral follicles can grow, and acquire meiotic competence in vitro.

Orientational distribution of collagen fibers in cobra skin

The orientation and distribution of collagen fibers were studied in leather prepared from cobra skin using both the mechanical method and Osaki's microwave method. The degree of preferred collagen-fiber orientation was largest at the centre of the dorsum and decreased gradually from the dorsum to the abdomen. The collagen fibers were, on average, aligned parallel to the spinal column in the dorsum, and tended to be aligned equally in all directions in the abdomen. The skin expanded easily in the direction perpendicular to the direction of collagen-fiber orientation. These results indicate that it is difficult for the skin to expand or shrink in the cranial to caudal direction, whereas it is relatively easy for the skin to expand around the circumference of the body of the cobra. Collagen-fiber orientation therefore seems to be closely related to the functional motions of cobra skin during locomotion and when swallowing prey.

Multiple superconducting phases in new heavy fermion superconductor PrOs4Sb12

The superconducting gap structure of recently discovered heavy fermion superconductor PrOs4Sb12 was investigated by using thermal transport measurements in magnetic field rotated relative to the crystal axes. We demonstrate that a novel change in the symmetry of the superconducting gap function occurs deep inside the superconducting state, giving a clear indication of the presence of two distinct superconducting phases with twofold and fourfold symmetries. We infer that the gap functions in both phases have a point node singularity, in contrast to the familiar line node singularity observed in almost all unconventional superconductors.

Transfer of IkappaBalpha gene increase the sensitivity of paclitaxel mediated with caspase 3 activation in human lung cancer cell

In oncogenic therapies, apoptosis seems to be the important mechanism of deciding chemotherapy effect. NF-kappaB transcription factors are implicated in the control of cell proliferation and apoptosis. NF-kappaB is activated by chemotherapy and by irradiation, and this pathway has been shown to protect cells potently from their stimuli-induced apoptosis. Furthermore, inhibition of NF-kappaB leads to enhanced apoptosis in response to various stimuli. However, because the role of NF-kappaB as a modifier of the intrinsic chemosensitivity of cancer cells is less clear, we have studied the impact of IkappaBalpha (an inhibitor of NF-kappaB) on the chemosensitivity of human lung cancer cells. We used adenoviral vectors expressing human IkappaBalpha (AdIkappaBalpha) and investigated the effects of IkappaBalpha gene transfer in combination with 6 anticancer agents on a human pulmonary adenocarcinoma cell line, A549. Solutions containing anticancer agents at various concentrations were added followed by the addition of recombinant adenovirus solutions, and each IC50 was calculated based on the dose-response curves. The gene transfer of AdIkappaBalpha decreased IC50 from 12.0 to 2.2 nM on paclitaxel and increased IC50 from 0.27 to 16.0 microM on SM5887 compared with the transfer of control gene, AdLacZ. The IC50 did not change clearly on the other anticancer drugs. To investigate this molecular mechanism, we measured caspase 3 activity by the transfer of IkappaBalpha gene. On result, paclitaxel increased caspase 3 activity and SM5887 decreased the activity. These results indicate that the cell killing effect of anticancer drug is influenced by the inhibition of NF-kappaB activity and may, at least in part, depend on the regulation of caspase 3 activation. Adenovirus mediated IkappaBalpha gene transfer improve the anti-cancer effect of paclitaxel to lung cancer cells through the regulation of caspase 3 activation.

Orientation and distribution of collagen fibers in the sagittal plane of the human adult calcaneus

Human right calcaneus bone, consisting of hydroxyapatite and collagen fibers, was cut in the sagittal plane which was parallel to the long axes of the calcaneus bone and the human lower limb, into samples approximately 1.5 mm thick. The angular dependence of transmitted microwave intensity at 12 GHz was measured for each sample, using Osaki's microwave method. The direction and the degree of collagen-fiber orientation for the cut specimens changed with changing position from the heel end to the anterior, along to the long axis of the calcaneus bone. The direction of orientation deviated by about -60 degrees from the direction of the long axis of the human lower limb, in the region between the heel end and the middle, and by about 60 degrees near the anterior. The position at which the orientation angle changed drastically from negative to positive corresponded to the neck defined as the position where a posterior face of the talus contacts the calcaneus. The results suggest that the mechanical stress applied to the neck of the calcaneus bone from the lower limb may effectively disperse, on average, in two different directions where the collagen fibers are oriented at the neck.

Effects of acute and chronic alacepril treatment on exercise capacity and hemodynamics in patients with heart failure: a preliminary study

OBJECTIVE

This study determined whether alacepril treatment improves exercise hemodynamics in patients with heart failure.

METHODS

Supine bicycle ergometer exercise was performed after administration of placebo and after acute and chronic (12 weeks) alacepril treatment in 4 patients with heart failure. Oxygen uptake (VO2), arterial oxygen saturation (SaO2), and mixed venous oxygen saturation (SvO2) were measured continuously using a pulse oxymeter and a fiber optic catheter. Cardiac index was calculated with Fick's equation.

RESULTS

Acute alacepril treatment did not significantly alter the VO2 or hemodynamics. After chronic alacepril treatment, peak VO2 increased (placebo vs chronic alacepril treatment: 17.7 +/- 2.8 vs 21.7 +/- 2.8 ml/min/kg, p < 0.05). Arteriovenous oxygen difference (SaO2 - SvO2) at peak exercise was not altered, however, cardiac index at peak exercise (5.07 0.67 vs 6.35 +/- 0.48 I/min/m2, p = 0.02) increased and stroke volume index at peak exercise (37.3 +/- 3.4 vs 46.5 +/- 1.1 ml/m2, p = 0.07) tended to increase.

CONCLUSIONS

Chronic treatment with alacepril improved maximal exercise capacity in patients with heart failure. The increased peak VO2 was primarily due to the increased cardiac index, but not due to the widening of arteriovenous oxygen difference. Therapy-induced increase in stroke volume index may contribute to the increased cardiac index at peak exercise in our patients with heart failure.

Biologically induced Po emission from fresh water

Behavior of Po in fresh waters was examined in laboratory culture experiments using fresh water collected from a small pool, Xi river and Xiqing lake, showing formation of volatile Po compounds followed by emission to air. Addition of tryptone to the fresh water cultures increased the emission of Po considerably along with a growth of microorganisms, suggesting a connection of chemoheterotrophs to Po emission. Participation of photoautotrophs was also considered because Po emission was increased when NaHCO3 was added to the fresh water cultures. The emission behavior of Po and S in these experiments appeared in different ways. The quantity of Po emitted was comparable to the previous culture experiments (Momoshima, Song, Osaki & Maeda, Environ. Sci. Technol., 35, 2956-2960, 2001) in which artificial culture medium containing 3% NaCl was used and inoculated with sea sediment extract. The biological support for Po emission, thus, would be a general phenomenon in fresh water as well as a seawater environment and is possibly a source for atmospheric Po.

Use of hair pores to determine the orientation of collagen fibers in skin

Most people are interested in recovery of skin defects caused by burn, scald or trauma from the aesthetic and functional point of view. It will occupy an important role for successful skin graft for patients with such skin defects that the orientation of collagen fibers in the grafted skin matches to the fiber orientation in surrounding skin. There have been, to my best knowledge, no methods for determining the orientation of collagen fibers in the skin from the clinical point of view. Recently, the author has found a new method for directly determining the collagen-fiber orientation without cutting samples from a calf leather by analyzing the anisotropic shape of hair pore. Its principle is based on the quantitative evaluation of collagen-fiber orientation by approximating a hair pore to an ellipse. The results obtained by the new method using hair pores were supported by the microwave method, mechanical measurements and scanning electron microscopy. Such a method will be applicable for determining the orientational distribution of collagen fibers in skins of animals and humans and give a valuable probe for performing skin grafting based on the scientific data of hair pores.

Formation and emission of volatile polonium compound by microbial activity and polonium methylation with methylcobalamin

We observed biologically mediated emission of Po from culture solution inoculated sea sediment extract and incubated under natural light/dark cycle condition or dark condition the emitted Po compound would be lipophilic because of effective collection in organic solvent. Sterilization of the culture medium with antibiotics or CuSO4 completely suppressed growth of microorganisms and resulted in no emission of Po, indicating biological activity of microorganisms is responsible for formation and emission of volatile Po compound. Po emission also occurred when seawater was used as a culture medium. Our finding indicates a possibility of biotic source for atmospheric Po in the environment, which has been believed to be originated from abiotic sources. We compared emission behavior of Po and S in the culture experiments, the elements belong to XVI group in the Periodical Table, and consider that their emission mechanisms involved would be different though the emission of both elements is supported by biological activity of microorganisms. One of the chemical forms of S emitted was confirmed to be dimethyl sulfide (DMS) but that of Po is not known. Methylation experiments of Po with methylcobalamin demonstrated a formation and emission of volatile Po compound. The methylation of Po with methylcobalamin might be related to the observed Po emission in the culture experiments.

Altered purine nucleotide degradation during exercise in patients with essential hypertension

Purine degradation occurs during strenuous muscle exercise and plasma levels of hypoxanthine (HX), purine degradation intermediate, increase. Purine nucleotide degradation has not been investigated in patients with essential hypertension (HTN). The present study determined whether purine nucleotide degradation is altered in patients with HTN. Cardiopulmonary exercise test was performed with serial measurements in blood lactate and plasma HX in 24 patients (14 men and 10 women) with essential HTN (World Health Organization [WHO] class I to II; mean age, 57.7 +/- 2.1 years) and 24 age-, sex-matched normal subjects. Exercise was terminated either by severe fatigue or excess blood pressure increase. Peak work rate (WR) (normal v HTN, 151 +/- 10 v 135 +/- 8 W, not significant [NS]) was not different, but peak oxygen uptake (peak Vo(2), 26.3 +/- 1.5 v 22.2 +/- 0.9 mL/min/kg, P <.05) and anaerobic threshold were lower in patients with HTN. Resting levels of blood lactate and plasma HX were similar, but the increment from rest to peak exercise (Delta) for lactate (Delta lactate: 4.4 +/- 0.4 v 3.4 +/- 0.4 mmol/L, P <.05) and for HX (Delta HX, 15.9 +/- 2.2 v 9.1 +/- 1.1 micromol/L, P <.05) were significantly smaller in patients with HTN. When normalized by the peak WR, Delta HX/peak WR (0.105 +/- 0.013 v 0.069 +/- 0.007 micromol/L/W, P <.05) was significantly lower in patients with HTN. Patients with HTN exhibited reduced HX response to exercise with impaired exercise capacity. The exercise-induced changes in plasma HX were smaller in patients with HT when normalized with peak WR. These results suggest that the purine nucleotide degradation is reduced in patients with HTN.

Comparison of cedar pollen-induced allergic rhinitis in passively and actively sensitized guinea pigs

We have developed an allergic rhinitis model in guinea pigs using Japanese cedar pollen as antigen. In the present study, we examined whether provocation by pollen induces similar magnitudes of rhinitis symptoms in passively and actively sensitized guinea pigs. One group of animals was actively sensitized by intranasal application of pollen extract, and another was passively sensitized by intraperitoneal injection with anti-pollen serum. Actively and passively sensitized groups were then challenged by repeated and a single pollen inhalation, respectively. In both groups, sneeze was induced immediately after the challenge. The actively sensitized animals developed not only early but also late nasal blockage, whereas the passively sensitized animals showed only early nasal blockage. In both groups, an H1 antagonist, mepyramine, inhibited the occurrence of sneezing but did not inhibit nasal blockage. Nasal hyperresponsiveness to intranasal instillation of leukotriene D4 was obvious only in the actively sensitized animals. We thus conclude that although early nasal blockage is induced by a single antigen-antibody reaction, repetitive anaphylactic reaction is required for occurrence of late nasal blockage and hyperresponsiveness to stimuli. Furthermore, histamine plays a central role in induction of sneezing but not in nasal blockage, irrespective of whether animals are actively or passively sensitized.

L-arabinose feeding prevents increases due to dietary sucrose in lipogenic enzymes and triacylglycerol levels in rats

L-Arabinose is a natural, poorly absorbed pentose that selectively inhibits intestinal sucrase activity. To investigate the effects of L-arabinose feeding on lipogenesis due to its inhibition of sucrase, rats were fed 0-30 g sucrose/100 g diets containing 0-1 g L-arabinose/100 g for 10 d. Lipogenic enzyme activities and triacylglycerol concentrations in the liver were significantly increased by dietary sucrose, and arabinose significantly prevented these increases. Arabinose feeding reduced the weights of epididymal adipose tissue. Moreover, plasma insulin and triacylglycerol concentrations were significantly reduced by dietary L-arabinose. These findings suggest that L-arabinose inhibits intestinal sucrase activity, thereby reducing sucrose utilization, and consequently decreasing lipogenesis.