Pharmacokinetics of Dietary 13C-Labeled Docosahexaenoic Acid and Docosapentaenoic Acid in Red Sea Bream Chrysophrys major

The objectives of this study were to investigate: 1) the pharmacokinetics of dietary docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) using ¹³C-labeled fatty acids; 2) the interorgan transport of DHA in the red sea bream by monitoring the DHA level of several organs; and 3) the relationship between the plasma DHA level and optimum dietary DHA level in the plasma of the red sea bream Chrysophrys major . For this purpose, a mixture of 38.5% of [¹³C]DHA, 8.5% of [¹³C]DPA, and 4.2% of [¹³C]palmitic acid were given to the red sea bream at dose level of 8.0, 16.0, and 47.9 mg/kg by a single oral administration. For [¹³C]DHA, the maximum plasma concentration (t_max) occurred at 2.00–3.00 h after the oral administration. The peak plasma concentration (C_max) and the area under the plasma concentration-time curve to 24 h (AUC_0-24 for [¹³C]DHA level linearly increased with respect to dosage. [¹³C]DHA appeared in each organ (plasma, erythrocyte and the fat body of the orbit, liver, intestine, skin, brain, heart and muscle) at 0.5 h and was observed until 24 h. From the values determined for the pharmacokinetic parameters, the range of the effective plasma DHA level for normal growth of the red sea bream was suggested to be between 21.0 and 40.3 μg/mL. For [¹³C]DPA, the AUC_0-24 and C_max values also linearly increased with the dosage, but t_max did not depend on it.     

Prehistoric hawaiian fishponds

One of the important technological concepts that was developed in the Hawaiian Islands is that of the fishpond. From the 14th to the 19th centuries, these sites served as aquariums for the raising of selected fish. From its inception until the 1900's, the fishpond progressed little in design and function. Its rudimentary nature was a function of both technology and religion. Because of the open ditches, sluice grates, and permeable walls, neither the types nor the quantity of juvenile fish entering or leaving could be controlled. In addition, religious beliefs prevented experimenting with fertilization to increase yield. Although seemingly inefficient, the native aquacultural system was not intended to produce a great amount of fish but rather to yield selected fish on call. Fishponds became symbols of the chiefly right to conspicuous consumption and to ownership of the land and its resources. They were manifestations of the chief's political power and his ability to control and tap his resources. As soon as the native aristocracy changed to a Western-style kingdom, the fishpond's function changed, until, by the 1930' s, the majority were simply archeological remains-mounds and walls of rock along a river or shore.     

Comparison of estrus induction and subsequent fertility with two different intravaginal devices in ewes during the non-breeding season

Two experiments were conducted to compare the effect of estrus induction by controlled internal drug release (CIDR) and intravaginal cream containing 500 mg progesterone (P cream) in ewes during the non-breeding season. In the first experiment, twenty-four ewes were randomly grouped for two treatments with the different intravaginal devices for 12 days: Group A was the CIDR group and Group B was the P cream group. Blood was collected from all treated ewes, and progesterone (P(4)), estradiol 17-beta (E(2)) and luteinizing hormone (LH) concentrations were measured by enzyme immunoassay. In the second experiment, the conception rates from natural mating, estrus-detected AI (inseminated 12 h after estrus detection), or fixed-time AI (inseminated 42 h after removal of an intravaginal device) in 127 ewes treated with CIDR or P cream were compared. In Experiment 1, the rate of estrus induction and the time of estrus onset after device removal were 91.7% and 36.3 +/- 15.7 h in Group A, and 100% and 35.0 +/- 12.6 h in Group B, respectively. There were no significant differences between the devices. The mean plasma P(4) concentration in Group B was significantly (P < 0.01) lower than Group A between day -9 and day -1 (Day 0: the day of device removal). However, no significant differences were found in the mean E(2) concentrations of the two groups after treatment. The mean time of estrus onset in ewes with an observed LH surge and the time of LH surge after treatment were 23.3 +/- 8.7 h and 30.3 +/- 5.0 h for Group A and 27.6 +/- 6.5 and 26.3 +/- 8.0 h for Group B, respectively, and there were no significant differences. However, a significant difference (P < 0.05) was found in the mean time from the time of estrus onset to LH surge between Group A (6.4 +/- 6.7 h) and Group B (-1.3 +/- 4.1 h). In Experiment 2, the conception rates for natural mating, estrus-detected AI, and fixed-time AI were 55.0, 29.4, and 25.0% for Group A and 40.7, 25.0, and 42.1% for Group B, respectively, and there were no significant differences. These results suggest that the effect of induction of estrus and ovulation and the rate of conception after treatment were comparable to CIDR even though the plasma P(4) concentration of the P cream method tended to be low during the insertion period.     

N-acetylglucosaminyltransferase I activity of bovine oviduct epithelial cells: stimulation by luteinizing hormone, vascular endothelial growth factor and tumor necrosis factor alpha

N-acetylglucosaminyltransferase I (GnT I; EC 2.4.1.101), which catalyzes the first step in the conversion of oligomannose to complex or hybrid N-glycans of glycoproteins, was found in media cultured with bovine oviduct epithelial cells (BOEC) obtained from non-pregnant cows during the follicular phase. Combined treatment with specific hormones increased GnT I release from BOEC. Luteinizing hormone (LH; 10 ng/ml) alone slightly, but together with 17beta-estradiol (E2; 1 ng/ml), synergistically increased GnT I activity. Vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF) alpha, which have been shown to have their highest activities in the bovine oviduct during the periovulatory period, also increased in GnT I activity. This study provides the first evidence of an increase of GnT I release from BOEC in vitro, and shows that endocrine as well as local factors such as LH, VEGF and TNFalpha increase this activity. The results suggest that GnT I activity in the bovine oviduct may contribute to the induction of glycosylation and thereby contributing to the provision of the optimal microenvironment for fertilization and early development of the embryos.     

Developmental competence of porcine blastocysts produced in vitro

The establishment of in vitro embryo production (IVP) system in pigs enables us to generate viable embryos with a quality equal to that of in vivo derived embryos. This technology contributes not only to developments in reproductive physiology and agriculture but also to biotechnologies for producing cloned or genetically modified pigs. The birth of piglets from in vitro matured and fertilized embryos at the two- to 4-cell stage was first achieved about 10 years ago, but it was only quite recently that piglets were produced after the transfer of IVP blastocysts. This improvement to the blastocyst stage of the in vitro culture system after in vitro maturation and fertilization can be expected to play a part in the development of an advanced IVP system. Here, we discuss the developmental ability of porcine embryos produced by our improved IVP system and the utilization of this technique in the new biotechnology.     

Relationship between serum sex hormone concentrations and histology of seminiferous tubules of captured baleen whales in the Western North Pacific during the feeding season

The present study was conducted to obtain new information on relationships among serum testosterone (T), estradiol-17 beta (E(2)), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) concentrations and histology of seminiferous tubules in captured common minke and Bryde's whales during the feeding season. Blood samples and testes were collected from common minke (n=39 for blood samples, n=15 for testes) and Bryde's (n=14 for blood samples, n=7 for testes) whales captured from May 2001 to August 2001 in the Western North Pacific. Serum T concentrations, in 35.9% of the common minke and 57.1% of Bryde's whales, were below the detection limit (< 2.5 pg/ml). There were no significant differences in the serum concentrations of E(2), FSH, and LH among immature, mature common minke and Bryde's whales except that LH levels of immature Bryde's whales was higher than those of common minke whales. In most seminiferous tubules of mature whales, only a single-layer of spermatogonia was observed. However, spermatozoa were observed in seminiferous tubules in 2/13 of mature common minke and 4/4 of mature Bryde's whales with the low or undetectable T levels. These results indicate that the low serum T concentrations reflect the inactivity of spermatogenesis in both baleen whales, and that it is not possible to assess gonadal activity in either common minke or Bryde's whales using serum sex hormone concentrations during the feeding season.     

Seroprevalence of Bartonella infection in American free-ranging and captive pumas (Felis concolor) and bobcats (Lynx rufus)

Bartonella henselae is the main agent of cat scratch disease in humans and domestic cats are the main reservoir of this bacterium. We conducted a serosurvey to investigate the role of American wild felids as a potential reservoir of Bartonella species. A total of 479 samples (439 serum samples and 40 Nobuto strips) collected between 1984 and 1999 from pumas (Felis concolor) and 91 samples (58 serum samples and 33 Nobuto strips) collected from bobcats (Lynx rufus) in North America, Central America and South America were screened for B. henselae antibodies. The overall prevalence of B. henselae antibodies was respectively 19.4% in pumas and 23.1% in bobcats, with regional variations. In the USA, pumas from the southwestern states were more likely to be seropositive for B. henselae (prevalence ratio (PR) = 2.82, 95% confidence interval (CI) = 1.55, 5.11) than pumas from the Northwest and Mountain states. Similarly, adults were more likely to be B. henselae seropositive than juveniles and kittens (PR = 1.77, 95% CI = 1.07, 2.93). Adult pumas were more likely to have higher B. henselae antibody titers than juveniles and kittens (p = 0.026). B. henselae antibody prevalence was 22.4% (19/85) in bobcats from the USA and 33.3% (2/6) in the Mexican bobcats. In the USA, antibody prevalence varied depending on the geographical origin of the bobcats. In California, the highest prevalence was in bobcats from the coastal range (37.5%). These results suggest a potential role of wild felids in the epidemiological cycle of Bartonella henselae or closely related Bartonella species.     

In vitro and in vivo developmental ability of oocytes derived from porcine primordial follicles xenografted into nude mice

We evaluated the developmental ability of oocytes in porcine primordial follicles xenografted into nude mice. Ovarian tissues from 20-day-old piglets, in which most of the follicles were primordial, were transplanted under the kidney capsules of ovariectomized nude mice. Forty-nine to 89 days after grafting (mean +/- SEM, 66.9 +/- 1.9 days; n = 64), the host mice showed the presence of cornified epithelial cells in their vaginal smears for the first time. The mice were then treated with 4 IU of equine chorionic gonadotropin (eCG) 60 days after first detection of vaginal cornification. Oocytes were collected from the host mice 48 h after treatment with eCG, and then matured. The maturation rates, based on the incidence of first polar body, ranged from 25.1% to 42.5%. They were then fertilized in vitro and cultured in vitro for 6 days, or transferred into estrous-synchronized recipients and recovered after 6 days. On Day 6 of culture, 15.4% of the matured oocytes had cleaved to the 2- to 8-cell stage. However, neither the embryos cultured in vitro nor those transferred and recovered developed to advanced embryonic stages, such as morulae or blastocysts. This result suggests that the developmental ability of xenografted oocytes is insufficient, even after in vitro maturation. Further strategies, such as improvement of hormonal treatment for host mice, are required to enable oocytes in xenografted ovarian tissues to acquire the cytoplasmic maturation necessary for embryonic development.