Urinary steroids in the periparturient and postpartum periods through early pregnancy in llamas

Urinary steroids were determined daily in the periparturient and postpartum periods, including early pregnancy, in the female llama. Estrone sulfate (E(1)S) and pregnanediol glucuronide (PdG) concentrations were determined by enzyme immunoassay with values corrected for variations in urine concentration by creatinine. Estrone sulfate concentrations, elevated during the last 20 days of gestation through 12 hours before parturition, were declining at the time of delivery. Pregnanediol glucuronide concentrations followed a pattern similar to that of estrone sulfate except that values began to decrease 5 days before parturition. Values for both E(1)S and PdG were basal by 24 hours after delivery. The first significant elevation of estrone sulfate, indicative of initial follicle development, was observed 5 days after parturition. Pregnanediol glucuronide concentrations were low during the postpartum period until 4 to 5 days after breeding. The PdG values rose steadily following copulatory-induced ovulation, which was initiated at about 2 weeks postpartum; values continued to increase through the first 15 days of pregnancy.     

Release of prostaglandin F2α during the bovine peripartal period

Progesterone, estrone and 15-keto-13,14-dihydro-PGF_2α levels were determined in the peripheral blood circulation during the peripartal period in 12 cows. Plasma concentrations of progesterone showed a gradual and continuous decrease during the last 60 days before parturition. This gradual decrease was followed by an abrupt decline in the progesterone concentration occurring 24–48 hours before delivery. The plasma levels of estrone started to increase about 30 days prior to parturition with high concentrations attained during the last days of pregnancy. After delivery the estrone content decreased to baseline levels. Increased levels of the PGF_2α metabolite were recorded 24–48 hours before parturition. These increased PGF_2α metabolite levels occurred before or in conjunction with prepartum luteolysis. Prostaglandin metabolite levels remained high during parturition and returned to baseline 10–20 days after delivery.     

Survival of Brucella abortus Strain RB51 Lyophilized and as Liquid Vaccine under Different Storage Conditions

Brucella abortus strain RB51 (SRB51) is a new cattle vaccine that is approved for use in the U.S. for prevention of brucellosis. At the present time, other countries are implementing or considering the use of SRB51 vaccine in their brucellosis control programs. In the current study, the effect of three stabilizing media, two fill volumes (1 and 3 ml), and three storage temperatures (−25, 4 and 25°C) on the viability of lyophilized SRB51 over a 52 week period was determined. The effects of three concentrations of bacteria (5×10⁸, 1×10⁹, or 5×10⁹ cfu/ml) and two storage temperatures (4 or 25°C) on viability of liquid SRB51 vaccine were also determined. For lyophilized strain RB51 vaccine, fill volume did not influence viability (P> 0·05) during lyophilization. Although fill volume did not influence viability during storage in World Health Organization (WHO) media or media containing both WHO and Lactose Salt (LS) media, 1 ml fill volumes of SRB51 in LS media had greater (P< 0·05) viability when compared to 3 ml fill volumes. Lyophilized SRB51 vaccine stored at 25°C had a more rapid decline in viability (P< 0·05) when compared to vaccine stored at −25 or 4°C. With the exception of the 3-ml fill volumes of LS media, all three stabilizing media were similar in maintaining viability of SRB51 at −25°C storage temperatures. However, when compared to WHO or WHO/LS media, stabilization in LS media was associated with a more rapid decline in viability during storage at 4 or 25°C (P< 0·05). Initial SRB51 concentration in liquid vaccine did not influence (P> 0·05) viability during storage at 4 or 25°C. When compared to liquid SRB51 vaccine stored at 25°C, storage at 4°C was associated with a slower decline in viability (P< 0·05) during 12 weeks of storage. Biochemical and morphological characteristics of SRB51 were stable under the storage conditions utilized in the present study. This study suggests that viability of SRB51 can be readily maintained during storage as a lyophilized or liquid brucellosis vaccine.     

Comparison of the digestible energy content of maize, oats and alfalfa between the European wild boar (Sus scrofa L.) and Landrace × Large White pig (Sus scrofa domesticus)

The objective of the current study was to compare the digestible energy (DE) contents of maize, oats and alfalfa meal between European wild boar (Sus scrofa L.) and the domestic pig (S. scrofa domesticus, Landrace × Large White). Six pure wild boar (S. scrofa L.) and six domestic pigs (Landrace × Large White) with liveweights (mean ± S.E.M.) of 26 ± 0.6 and 21 ± 1.1 kg, respectively, were fed diets at a daily level of 0.10 × metabolic body weight (W^0.75). The diets included a base diet and three experimental diets containing 700 g basal diet/kg and 300 g maize, oats or alfalfa meal/kg; all animals received all four diets. Chromic oxide was used as indigestible marker. The animals received each diet for an 8-day period with fecal samples collected on days 6, 7 and 8. The DE content of the maize, oats and alfalfa was calculated for each ingredient and statistically compared between the wild boar and domestic pig. For the maize and oats, there was no significant difference in the DE values between the domestic pig and wild boar. However, the DE value of the alfalfa was greater in the domestic pig (10.56 MJ kg⁻¹ DM) than in the wild boar (8.48 MJ kg⁻¹ DM). For ingredients that contain relatively low concentrations of fibre (such as maize and oats), it appears that DE values determined in the domestic pig can be validly applied for diet formulation for wild boars; however, for ingredients with higher fibre levels, the DE values in wild boar appear to be lower than those in the domestic pig.     

Time related changes in luteal prostaglandin synthesis and steroidogenic capacity during pregnancy, normal and antiprogestin induced luteolysis in the bitch

In nonpregnant and pregnant dogs the corpora lutea (CL) are the only source of progesterone (P4) which shows an almost identical secretion pattern until the rapid decrease of P4 prior to parturition. For the nonpregnant dog clear evidence has been obtained that physiological luteal regression is devoid of a functional role of the PGF2α-system and seems to depend on the provision of StAR. Yet in pregnant dogs the rapid prepartal luteal regression, coinciding with an increase of PGF2α, may be indicative for different regulatory mechanisms. To assess this situation and by applying semi-quantitative Real Time (Taq Man) RT-PCR, expression patterns were determined for the following factors in CL of pregnant and prepartal dogs and of mid-pregnant dogs treated with the antiprogestin Aglepristone: cyclooxygenase 2 (Cox2), prostaglandin E2 synthase (PGES), prostaglandin F2α synthase (PGFS), its receptors (EP2, EP4 an FP), the steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid-dehydrogenase (3βHSD) and the progesterone receptor (PR). Peripheral plasma P4 concentrations were determined by RIA. CL were collected via ovariohysterectomy from pregnant bitches (n = 3–5) on days 8–12 (Group 1, pre-implantation period), days 18–25 (Group 2, post-implantation period), days 35–40 (Group 3, mid-gestation period) and during the prepartal progesterone decline (Group 4). Additionally, CL were obtained from groups of 5 mid-pregnant dogs (days 40–45) 24 h, respectively 72 h after the second treatment with Aglepristone. Expression of Cox2 and PGES was highest during the pre-implantation period, that of PGFS and FP during the post-implantation period. EP4 and EP2 revealed a constant expression pattern throughout pregnancy with a prepartal upregulation of EP2. 3βHSD and StAR decreased significantly from the pre-implatation period to prepartal luteolysis, it was matched by the course of P4 concentrations. Expression of the PR was higher during mid-gestation and prepartal luteolysis than in the two preceding periods. After application of Aglepristone the overall mRNA-expression resembled the situation during prepartal luteolysis except for EP2, which remained unchanged.These data suggest that – as in the nonpregnant bitch – also in the pregnant bitch luteal production of prostaglandins is associated with luteal support rather than luteolysis. On the other hand induction of luteolysis by the PR blocker Aglepristone points to a role of luteal P4 as an autocrine factor in a positive loop feedback system controlling the availability of P4, StAR and 3βHSD.     

Flumethason-induced calving is preceded by a period of myometrial inhibition during luteolysis

The temporal relationship among changes of the concentrations of the 13,14-dihydro-15-keto metabolite of prostaglandin F2 alpha (PGFM), estrone (E1) and estrone sulphate (E1S) in maternal arterial plasma (MP) and amniotic fluid (AF), the prepartum progesterone (P4) decline in MP, and the evolution of uterine electromyographic (EMG) activity was investigated in 6 cows. Calving was induced by a single i.m. injection of 5 mg flumethason on Day 270 of gestation. The period under investigation was subdivided into four consecutive periods: Period 1 covered the last 2 days before flumethason treatment; Period 2 (mean +/- SEM duration: 16.1 +/- 2.5 h), Period 3 (8.8 +/- 1.1 h), and Period 4 (13.0 +/- 1.5 h) together included the interval between injection and the onset of the expulsive stage of induced parturition. Each was defined by its pattern of uterine EMG activity. During Periods 1 and 2, this activity occurred in long episodes (2-20 min; contractures) at a similar mean (+/- SEM) frequency (0.51 +/- 0.14/h and 0.42 +/- 0.07/h, respectively). No significant differences in hormonal concentrations in MP and AF between these two periods were detected. During Period 3, contractures nearly disappeared (freq: 0.09 +/- 0.05/h), and in MP mean P4 levels were significantly lower and PGFM levels were significantly higher than before. Mean PGFM concentrations in AF were not significantly changed during Period 3. Finally, during Period 4, EMG activity reappeared and a parturient EMG pattern gradually evolved in the presence of a further significant decline of P4 levels and significant increase of PGFM concentrations in MP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum and urinary hormones during pregnancy and the peri- and postpartum period in an Asian elephant (Elephas,maximus)

Blood and urine samples were collected weekly from an Asian elephant (Elephas maximus) for 10 months before conception, throughout pregnancy, and for 10 months after parturition. Additional daily samples were collected for 41 days before through 10 days after parturition to define endocrine events during the peripartum period. During gestation, serum progesterone concentrations increased gradually and, after ～13 weeks, were higher (P < 0.05) than those observed during the nonpregnant luteal phase. Concentrations peaked at ～12 months of gestation, gradually declined during the last month, and then decreased sharply to nondetectable levels 2 days before parturition. A 12 week lactational anestrus was observed before cyclicity resumed. The urinary profile of progestagen excretion paralleled that of circulating progesterone (r = 0.79; P < 0.05); however, radioimmunoassay of HPLC-separated fractions of urinary eluates indicated that this immunoactivity was not associated with native progesterone. After remaining basal through the first 16 weeks of gestation, serum prolactin concentrations increased to 100-fold about midterm and remained elevated until after parturition. Neither serum nor urinary cortisol concentrations were altered during pregnancy, but both increased markedly the day after parturition and remained elevated above prepartum levels for several weeks thereafter. These data indicate that analysis of serum prolactin can confirm pregnancy in the Asian elephant after ～4 months of gestation and that daily monitoring of serum or urinary progestagens is useful for predicting parturition. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Interactions between Prorocentrum donghaiense Lu and Scrippsiella trochoidea (Stein) Loeblich III under laboratory culture

Interactions between Prorocentrum donghaiense Lu and Scrippsiella trochoidea (Stein) Loeblich III, two species of causative bloom dinoflagellates in China, were investigated using bi-algal cultures under controlled laboratory conditions. The growth of P. donghaiense and S. trochoidea were significantly suppressed when the initial cell densities were set at 1.9 × 10⁴ cells mL⁻¹ or 1.9 × 10⁵ cells mL⁻¹ for P. donghaiense and 1.0 × 10⁴ cells mL⁻¹ for S. trochoidea when the initial size/density ratio was 1:1 or 10:1, respectively, but no out-competement was observed in either bi-algal culture by the end. The simultaneous assay on the culture filtrate showed that P. donghaiense filtrate prepared at a lower initial density (1.9 × 10⁴ cells mL⁻¹) stimulated the co-cultured S. trochoidea at a density of 1.0 × 10⁴ cells mL⁻¹, but filtrate at a higher density (1.9 × 10⁵ cells mL⁻¹) depressed its growth. Differently, the filtrate of S. trochoidea at a density of 1.0 × 10⁴ cells mL⁻¹ significantly suppressed the growth of P. donghaiense at a density of 1.9 × 10⁴ cells mL⁻¹, but had little stimulatory effect on P. donghaiense at a density of 1.9 × 10⁵ cells mL⁻¹compared to the control (P > 0.05). It is likely that these two species of microalgae interact with each other mainly by releasing allelochemical substance(s) into the culture medium, and a direct cell-to-cell contact was not necessary for their mutual interaction. We then quantify their interactions in the bi-algal culture by using a mathematical model. The estimated parameters from the model showed that the inhibition exerted by S. trochoidea on P. donghaiense was about 43 and 24 times stronger than the inhibitory effect that P. donghaiense exerted on S. trochoidea when the initial size/density were 1:1 and 10:1, respectively. S. trochoidea seemed to have a survival strategy that was superior to P. donghaiense in the bi-algal culture under controlled laboratory conditions. We also observed a closely positive relationship between the initial cell density and its effect on the co-cultured microalga by measuring the fluorenscence: filtrate prepared from higher initial cell density had stronger interference on the co-cultured microalga. Moreover, pre-treated under different temperature conditions (30 °C, 60 °C and 100 °C) would significantly changed the effect of culture filtrate on the co-cultured microalga. Result inferred that P. donghaiense or S. trochoidea would release allelochemicals into the bi-algal culture medium and the allelochemicals might be a mixture with temperature-sensitive components in it.     

Bottom water oxygenation history in southeastern Arabian Sea during the past 140 ka: Results from redox-sensitive elements

The concentrations of multiple redox-sensitive elements such as Re, U, Mo, Cd, V, Sb, and Tl were determined in sediments from the southeastern Arabian Sea (9°21′N: 71°59′E) to understand the bottom water oxygenation history throughout the past 140 ka. The enrichment of redox-sensitive elements (Re, U, Cd and Sb) above average crustal abundances suggests that the Last Glacial Maxima (17.48 ka), stadials of Marine Isotope Stage (MIS)-5 (5b and 5d) and Glacial Termination (GT)-II (133 ka) were associated with suboxic bottom water conditions. Sediments deposited during these suboxic conditions show the highest Re content (up to 54 ppb normalized to a carbonate free basis) which is highly enriched over average continental crust (0.4 ppb) and these sediments appear to be the major sink for the global mass balance estimation. Marine Isotope Stages 1, 3, 4 and interstadials of MIS-5 (5a, 5c & 5e) were all associated with near-oxic conditions. Overall, the lack of enrichment of Mo and V above crustal abundance, and a high Re/Mo (ppm/ppm) ratio (avg. 18.2 × 10^− 3) suggest that sediments of the southeastern Arabian Sea never contained free H₂S during the last 140 ka. These changes in the bottom water oxygen content can be related to the oceanic circulation pattern during this time and in part are reflected in relationships between the timing of redox changes and paleoproductivity proxies.     

Quantitative detection of the oil-degrading bacterium Acinetobacter sp. strain MUB1 by hybridization probe based real-time PCR

Quantitative detection of the oil-degrading bacterium Acinetobacter sp. strain MUB1 was performed using the SoilMaster^™ DNA Extraction Kit (Epicentre, Madison, Wisconsin) and hybridization probe based real-time PCR. The detection target was the alkane hydroxylase gene (alkM). Standard curve construction showed a linear relation between log values of cell concentrations and real-time PCR threshold cycles over five orders of magnitude between 5.4±3.0×10⁶ and 5.4±3.0×10² CFU ml⁻¹ cell suspension. The detection limit was about 540 CFU ml⁻¹, which was ten times more sensitive than conventional PCR. The quantification of Acinetobacter sp. strain MUB1 cells in soil samples resulted in 46.67%, 82.41%, and 87.59% DNA recovery with a detection limit of 5.4±3.0×10⁴ CFU g⁻¹ dry soil. In this study, a method was developed for the specific, sensitive, and rapid quantification of the Acinetobacter sp. strain MUB1 in soil samples.     

Influence of prenatal photoperiod on postnatal prolactin secretion in red deer (Cervus elaphus).

Plasma prolactin concentrations were higher (P < 0.001) in newborn red deer calves whose mothers had been maintained for the last 14 weeks of gestation in long days (18 h light) (group L, n = 9) than in those whose mothers had been kept over the same period in short days (6 h light) (group S, n = 5). After transfer of all hinds and suckled calves on the day of birth to constant intermediate daylength (12 h light), prolactin concentrations decreased exponentially (P < 0.001) in group L calves, but not in group S, during the first 21 days. Thereafter, prolactin fell to a nadir in group L calves and rose to peak values in group S calves at 8-12 weeks post partum (P = 0.003), before converging again by 14 weeks. The pattern of prolactin secretion over the first 14 weeks of life was therefore significantly affected by prenatal photoperiod. Plasma prolactin concentrations in the adult hinds were higher (P < 0.001) in group L than group S at 4-10 weeks before parturition; they were similarly high around parturition and fell thereafter to baseline values after 7 weeks. These results provide evidence that deer fetuses respond to photoperiodic information, thereby acquiring a photoperiodic history in utero that influences postnatal responses to photoperiod.     

Effect of renoguanylin on hydrogen/bicarbonate ion transport in rat renal tubules

Renoguanylin (REN) is a recently described member of the guanylin family, which was first isolated from eels and is expressed in intestinal and specially kidney tissues. In the present work we evaluate the effects of REN on the mechanisms of hydrogen transport in rat renal tubules by the stationary microperfusion method. We evaluated the effect of 1 μM and 10 μM of renoguanylin (REN) on the reabsorption of bicarbonate in proximal and distal segments and found that there was a significant reduction in bicarbonate reabsorption. In proximal segments, REN promoted a significant effect at both 1 and 10 μM concentrations. Comparing control and REN concentration of 1 μM, JHCO₃⁻, nmol cm^− 2 s^− 1 − 1,76 ± 0,11_control × 1,29 ± 0,08_{REN 10 μM}; P < 0.05, was obtained. In distal segments the effect of both concentrations of REN was also effective, being significant e.g. at a concentration of 1 μM (JHCO₃⁻, nmol cm^− 2 s⁻ 1 − 0.80 ± 0.07_control × 0.60 ± 0.06_{REN 1 μM}; P < 0.05), although at a lower level than in the proximal tubule. Our results suggest that the action of REN on hydrogen transport involves the inhibition of Na⁺/H⁺exchanger and H⁺-ATPase in the luminal membrane of the perfused tubules by a PKG dependent pathway.     

Peroxidase catalyzed phenolic compounds oxidation in presence of surfactant Dynol 604: A kinetic investigation

The kinetics of fungal peroxidase-catalyzed phenolic compounds (PCs) oxidation was investigated in presence of acetylenic-based surfactant Dynol 604 at pH 5.5 and 25 °C. It was shown that the presence of ppm concentrations of surfactant did not influence initial rate of PCs oxidation. The calculated apparent bimolecular rate constants were (1.8 ± 0.2) × 10⁵ M⁻¹ s⁻¹, (1.4 ± 0.4) × 10⁷ M⁻¹ s⁻¹, (1.30 ± 0.06) × 10⁷ M⁻¹ s⁻¹ and 1.1 × 10⁸ M⁻¹ s⁻¹ for phenol, 1-naphthol, 2-naphthol and 1-hydroxypyrene, respectively.During an extensive substrates conversion Dynol 604 showed diverse action for different PCs. The oxidation of phenol practically did not change, whereas the surfactant enhanced the conversion of 1- and 2-naphthol and 1-hydroxypyrene in dose response manner. The results accounted by a scheme, which contains a stadium of enzyme inhibition by oligomeric PC oxidation products. The action of the surfactant was explained by avoidance the enzyme active center clothing with the oligomers. The results acquired demonstrate a remarkable increase of substrates conversion in the presence of Dynol 604.     

15-Ketodihydro-PGF2α, Progesterone and Cortisol Profiles in Heifers after Induction of Parturition by Injection of Dexamethasone

In order to study rapid changes in 15-ketodihydro-PGF_2α, cortisol and progesterone in the period preceding parturition in cattle, pre-term parturition was induced in 4 late pregnant heifers. Parturitions were induced by 2 intramuscular injections of 20 mg dexamethasone with a 24-h interval. The first injection was made on days 254, 258, 264 and 265 in gestation, respectively. Twenty-four h before the first injection an intravenous polyurethane cannula was inserted. Blood samples were collected at least every hour until 12 h after parturition and during the second stage of labour at least 6 times per hour. Plasma was analysed for 15-ketodihydro-PGF_2α and progesterone by radioimmunoassays, and for cortisol by an ELISA. The average time from injection to parturition was 7.7 (6.6–8.9) days (mean (range)). Two of the heifers had retained foetal membranes (RFM). At the start of the experiment the levels of PGF_2α metabolite were low (< 300 pmol/L) and increased slowly to levels between 1000 and 2000 pmol/L at one day before parturition. During the last day, however, the levels increased rapidly and the highest levels (>10000 pmol/L) were reached at the time of delivery. No pulsatile release was seen. Immediately after foetal expulsion the PG-metabolite levels decreased rapidly in all animals. In the 2 animals with RFM, however, this decline ceased within a few h. The PG-metabolite levels in these animals then started to increase and reached levels as high as during parturition. Luteolysis occurred between 1.6 and 0.4 days before parturition in all animals. The cortisol profile showed a distinct peak at the time of parturition in the RFM heifers. This peak was absent in the non-RFM heifers. This study shows that the PGF_2α release at prepartal luteolysis and parturition is not pulsatile in cattle and that cortisol profiles in heifers with retained foetal membranes might differ from the profiles in non-RFM heifers at the time of parturition.     

Peripheral plasma progesterone and utero-ovarian prostaglandin F concentrations in the cow around parturition

The concentration of prostaglandin F in utero-ovarian venous plasma and progesterone in jugular venous plasma were determined by radioimmunoassay in 3 cows over the last 2–3 weeks of gestation. Utero-ovarian prostaglandin F concentrations did not show any consistent pattern in two of three cows until 48–72 h before term when the levels rose sharply from 1 ng/ml to a maximum 4–9 ng/ml during labour. The concentration of progesterone in jugular venous plasma tended to fall gradually over the last 20 days of gestation with a further fall occurring 48-36 h before delivery.In two other cows at around 240 days of gestation the concentration of plasma progesterone in ovarian venous plasma was 50 to 150 times the concentration of progesterone in uterine or jugular venous plasma. It is concluded from these results that the ovaries are the major source of progesterone in cows during late pregnancy. The findings also suggest that prostaglandin F may be the luteolytic factor responsible for the sharp decline in plasma progesterone concentrations over the last 48-36 h preceding parturition.     

Peripartal plasma concentrations of 15-ketodihydro-PGF2α, cortisol, progesterone and 17-β-estradiol in Martina Franca jennies

The transition from intra- to extrauterine environment represents a very delicate phase, in which the successful coordination of maturation is strictly connected with several hormonal changes during the last weeks of gestation and at parturition. While the peripartal endocrinology in the mare has been deeply investigated, the peripartal hormonal changes in the jenny need further evaluation. The aim of this study is to evaluate the mean 15-ketodihydro-PGF_2α (PGFM), cortisol (C), progesterone (P4), and 17β-estradiol (E2) levels during the peripartal period in this species. Ten Martina Franca jennies, with normal gestational length and parturition, were enrolled. From each jenny, blood was collected twice a day from 10 d before to 7 d after parturition and from the plasma obtained PGFM, C, P4 and E2 were analyzed by RIA. Higher, constant PGFM concentrations were observed in the pre-foaling days compared to the decreasing levels detected the days after delivery, as previously observed in the mare. During the whole period of observation no significant differences in plasma C levels were detected. In contrast to the mare, P4 has always been detectable and the highest level found at −2.5 days was significantly different compared to samples obtained between −10 and −4.5 days and between 1.5 and 7 days after foaling. Finally, E2 showed higher concentrations before foaling, with the highest values between −3 and −1.5 days, decreasing only one day before foaling. A positive correlation was found between PGFM and P4, during the last 4 days of gestation, while a positive correlation between PGFM and E2 was observed during the prepartum. Despite some similarities with the mare exist, differences have been found in P4 and E2 profiles, underlining once more the differences in the physiology of this two species.     

Urinary gonadotropin and estrogen excretion during the postpartum estrus,conception, and pregnancy in the cotton-top tamarin (Saguinus oedipus oedipus)

Hormonal profiles during postpartum estrus, time of conception, and pregnancy were determined in urine samples from six cotton-top tamarins (Saguinus oedipus oedipus). Noninvasive collection techniques permitted daily sampling throughout lactation and pregnancy. Urinary estrone (E1), estradiol (E2), and both bioactive and immunoreactive luteinizing hormone/chorionic gonadotropin (LH/CG) measures revealed an interval of 19 ± 2.07 (S E M) days between parturition and the postpartum ovulatory LH peak. An increase in both E1 and E2 was seen prior to the LH peak; however, E1 and E2 continued to increase to their highest concentrations after the LH peak. Since postpartum ovulations resulted in pregnancy, neither postpartum estrus nor conception was suppressed by lactation. The length of gestation (measured from the LH peak to parturition) was 183.7 ± 1.14 (S E M) days, which is at least 30 days longer than that previously reported for other callitrichid species. Both E1 and E2 reached their maximum levels during midpregnancy but showed a rapid decline at parturition. Gestational levels of CG were first detectable approximately 20 days after the LH peak and continued to be elevated for approximately 80 days. The Sub-Human Primate Tube Test (SHPTT) for pregnancy did not detect the LH Peak and was less sensitive than other methods in detecting CG. Two RIA methods and a bioassay technique could not distinguish between LH and CG. We concluded that monitoring both estrogen and LH concentration was needed to determine when ovulation occurs in the cotton-top tamarin, since peak values of estrogen are seen after the ovulatory LH peak. Also, these tamarins were pregnant the majority of the time, indicating an unusually high fertility rate in contrast to most noncallitrichid primate species.     

Effects of 1,4-phenylenebis(methylene)selenocyanate on mutagenesis and p53 protein expression in the tongue of lacI rats treated with 4-nitroquinoline-N-oxide

Previously we showed that the organoselenium compound, 1,4-phenylenebis(methylene)selenocyanate (p-XSC)¹ inhibits 4-nitroquinoline-N-oxide (4-NQO)-induced tongue tumorigenesis in Fisher rats. Here we investigate possible mechanisms of this inhibition by monitoring mutagenesis and p53 protein levels in lacI and conventional Fisher rats treated with: (1) a carcinogenic dose of 4-NQO for 10 weeks in drinking water, (2) 4-NQO + p-XSC (15 ppm as selenium), and (3) 4-NQO followed by p-XSC. For mutagenesis studies, rats were euthanized at 7, 12 or 23 weeks after the start of 4-NQO. For studies on p53 levels, rats were euthanized at 11, 15 and 23 weeks. Appropriate controls were also monitored. In the 4-NQO-alone groups, the mutant fraction (MF) in the cII gene in tongue increased at least 50× background level. The MF (in units of mutants/10⁵ plaque forming units) for the 7, 12, and 23 weeks 4-NQO groups were respectively, 184 ± 88, 237 ± 105, and 329 ± 110. Thus, mutagenesis increased with length of exposure and post-treatment time. p-XSC modestly (ca. 15–30%) inhibited mutagenesis under all conditions. The inhibition reached significance at the last time point. When p-XSC was administered after 4-NQO, the MF was also modestly reduced. In 4-NQO-alone animals, levels of p53 in tongue (determined by Western blotting) were 1, 1.5 and 2.4 control levels at 10, 15 and 23 weeks, respectively. In the p-XSC + 4-NQO group, the enhancement in p53 levels by 4-NQO treatment was decreased about 90% at 15 weeks and 45% (P < 0.05) at 23 weeks, and by slightly smaller percentages in corresponding post-treatment groups. p-XSC alone did not alter p53 levels. As p53 levels generally increase in response to DNA damage, these results suggest that p-XSC reduces 4-NQO-induced DNA damage, resulting in reduced 4-NQO-induced mutagenesis and carcinogenesis. However, the fact that p-XSC is also effective when administered after 4-NQO, suggests additional mechanisms of inhibition exist.     

Diet and physiological responses of Spondyliosoma cantharus (Linnaeus, 1758) to the Caulerpa racemosa var. cylindracea invasion

Marine invasions are a worldwide problem that involves changes in communities and the acclimation of organisms to them. The invasive Chlorophyte Caulerpa racemosa var. cylindracea is widespread in the Mediterranean and colonises large areas from 0 to 70 m in depth. The omnivorous fish Spondyliosoma cantharus presents a high frequency of occurrence of C. racemosa in the stomach contents at invaded areas (76.3%) while no presence of C. racemosa was detected in control areas. The isotopic composition of muscle differed significantly between invaded and non-invaded sites for δ¹³C (− 16.67‰ ± 0.09 and − 17.67‰ ± 0.08, respectively), δ¹⁵N (10.22‰ ± 0.22 and 9.32‰ ± 0.18, respectively) and the C:N ratio (2.01 ± 0.0002 and 1.96 ± 0.009, respectively). Despite the high frequency of occurrence of C. racemosa in the stomach contents of S. cantharus and its important contribution to the δ¹³C source (20.7% ± 16.2), the contribution of C. racemosa to the δ¹⁵N in S. cantharus food sources was very low (6.6% ± 5.8). Other invertebrate prey such as decapods and polychaetes were more important contributors to the δ¹⁵N source at both invaded and non-invaded sites. Activation of enzymatic pathways (catalase, superoxide dismutase, glutathione-s-tranferase, 7-ethoxy resorufin O-de-ethylase) but not a significant increase in lipid peroxidation MDA (0.49 ± 0.01 nmol/mg prot at non-invaded and 0.53 ± 0.01 nmol/mg prot at invaded sites) was observed in S. cantharus individuals living in C. racemosa-invaded sites compared with control specimens. The low δ¹⁵N contribution values of C. racemosa by S. cantharus together with the toxicity demonstrated by the activation of the antioxidant defences and the important contribution of invertebrate prey to the δ¹⁵N could mean that the ingestion of C. racemosa by S. cantharus might be unintentional during the predation of invertebrate preys living underneath the entanglement of the C. racemosa fronds and stolons mats.     

Kinetic analyses for bindings of concanavalin A to dispersed and condensed mannose surfaces on a quartz crystal microbalance

A biotinylated mannotriose (Man3-bio) was dispersively immobilized in the matrix of biotinylated lactose (Gal-Glc-bio) on a streptavidin-covered, 27-MHz quartz crystal microbalance (QCM), and binding kinetics of concanavalin A (Con A) to Man3-bio in the Gal-Glc-bio matrix could be obtained from frequency decreases (mass increases) of the QCM. Association constants (K_a) and binding and dissociation rate constants (k_on and k_off) could be determined separately as the 1:1 and 1:2 bindings of Con A to Man3-bio on the surface. When Man3-bio was immobilized with content of 1 to 5 mol% in the matrix, the 1:1 binding of Con A to Man3-bio was obtained as K_a = (4 ± 1) × 10⁶ M⁻¹, k_on = (4 ± 1) × 10⁴ M⁻¹ s⁻¹, and k_off = (12 ± 2) × 10^–3 s⁻¹. On the contrary, when Man3-bio was immobilized with content of 20 to 100 mol% in the matrix, the 1:2 binding of Con A to Man3-bio was obtained as K_a = (14 ± 2) × 10⁶ M⁻¹, k_on = (14 ± 2) × 10⁴ M⁻¹ s⁻¹, and k_off = (7 ± 2) × 10^–3 s⁻¹. Thus, K_a for the 1:2 binding was 10 times larger than that for the 1:1 binding, with a three times larger binding rate constant (k_on) and a three times smaller dissociation rate constant (k_off). This is the first example to obtain separate kinetic parameters for the 1:1 and 1:2 bindings of lectins to carbohydrates on the surface.