Midtrimester abortion induced by serial intravaginal administration of prostaglandin E2 suppositories in conjunction with a contraceptive diaphragm

Midtrimester abortion was successfully induced in a series of 20 patient by intra-amniotic instillation of 15(S)-15-methyl-prostaglandin F_2α with a mean abortion time of 17.78 hours. The patients in this study were divided into two groups, Groups I received on initial dose of 2.5 mg 15-ME-PGF_2α and aborted in a mean time of 16.26 hours. The patients in Group II received 3.0 mg 15-ME-PGF_2α and aborted in a mean time of 18.94 hours. There was no significant difference in the abortion time, occurrence of side effects or the initiation of uterine activity between Group I and Group II. Parous patients aborted somewhat faster than nulliparous patients but this difference was not significant. In this study 80% of the patients aborted in 24 hours or less, and the intra-amniotic instillation of 15-ME-PGF_2α was an effective abortifacient technique from the 15th to the 23rd week of gestation. The uterine response to intra-amniotic instillation of 15-ME-PGF_2α was characterized by the gradual appearance of low amplitude, high frequency contractions accompanied by a rise in baseline intrauterine tonus. Uterine activity developed gradually and peaked at 1:50 hours after intra-amniotic instillation of 15-ME-PGF_2α. In this small series 15-ME-PGF_2α administered via intra-amniotic instillation did not appear to have a distinct advantage over the naturally occurring PGF_2α administered by the same method for the induction of midtrimester abortion; a larger series is indicated to define the advantages of either technique.     

Preoperative dilatation of the cervix by single vaginal administration of 15-methyl-PGF2α-methyl ester

Two different vaginal suppositories have been developed suitable for one single treatment for preoperative dilatation of the cervix prior to vacuum aspiration in late first trimester abortion. The study included 60 patients equally distributed in one control group (Group I) where vacuum aspiration was performed without pretreatment; one group (Group II) where the patients obtained 2.0 mg 15-methyl-PGF_2α-methyl ester in a rapid releasing base six hours prior to operation and one group (Group III) where the prostaglandin dose was increased to 2.5 mg 15-methyl-PGF_2α-methyl ester and a more slow releasing base was used and the operation performed after 12 hours. The mean cervical dilatation at operation was in Group II 9 mm and in Group III 11 mm in comparison with 4.8 mm in the control group. The bleeding at the operation was also significantly reduced.     

Midtrimester abortion induced by single intra-amniotic instillation of two dose schedules of 15(S)-15-methyl-prostaglandin F2alpha.

Midtrimester abortion was successfully induced in a series of 20 patient by intraamniotic instillation of 15(S)-15-methyl-prostaglandin F2alpha with a mean abortion time of 17.78 hours. The patients in this study was divided into two groups, Groups 1 received an initial dose of 2.5 mg 15-ME-PGF2alpha and aborted in a mean time of 16.26 hours. The patients in Group II received 3.0 mg 15-ME-PGF2alpha and aborted in a mean time of 18.94 hours. There was no significant difference in the abortion time, occurrence of side effects or the initiation of uterine activity between Group I and Group II. Parous patients aborted somewhat faster than nulliparous patients but this difference was not significant. In this study 80% of the patients aborted in 24 hours or less, and the intra-amniotic instillation of 15-ME-PGF2alpha was an effective abortifacient technique from the 15th to the 23rd week of gestation. The uterine response to intra-amniotic instillation of 15-ME-PGF2alpha was characterized by the gradual appearance of low amplitude, high frequency contractions accompanied by a rise in baseline intrauterine tonus. Uterine activity developed gradually and peaked at 1:50 hours after intraamniotic instillation of 15-ME-PGF2alpha. In this small series 15-ME-PGF2alpha administered via intra-amniotic instillation did not appear to have a distinct advantage over the naturally occuring PGF2alpha administered by the same method for the induction of midtrimester abortion; a large series in indicated to define the advantage of either technique.     

Midtrimester abortion induced by a single intra-amniotic instillation of two dose schedules of 15(S)-15-methyl-prostaglandin F2α

Midtrimester abortion was successfully induced in a series of 20 patient by intra-amniotic instillation of 15(S)-15-methyl-prostaglandin F_2α with a mean abortion time of 17.78 hours. The patients in this study were divided into two groups, Groups I received on initial dose of 2.5 mg 15-ME-PGF_2α and aborted in a mean time of 16.26 hours. The patients in Group II received 3.0 mg 15-ME-PGF_2α and aborted in a mean time of 18.94 hours. There was no significant difference in the abortion time, occurrence of side effects or the initiation of uterine activity between Group I and Group II. Parous patients aborted somewhat faster than nulliparous patients but this difference was not significant. In this study 80% of the patients aborted in 24 hours or less, and the intra-amniotic instillation of 15-ME-PGF_2α was an effective abortifacient technique from the 15th to the 23rd week of gestation. The uterine response to intra-amniotic instillation of 15-ME-PGF_2α was characterized by the gradual appearance of low amplitude, high frequency contractions accompanied by a rise in baseline intrauterine tonus. Uterine activity developed gradually and peaked at 1:50 hours after intra-amniotic instillation of 15-ME-PGF_2α. In this small series 15-ME-PGF_2α administered via intra-amniotic instillation did not appear to have a distinct advantage over the naturally occurring PGF_2α administered by the same method for the induction of midtrimester abortion; a larger series is indicated to define the advantages of either technique.     

Reproductive function of mares given daily injections of prostaglandin F2alpha beginning at day 42 of pregnancy

Mares at Day 42 of pregnancy received daily intramuscular (i.m.) injection of 5 mg of prostaglandin F2alpha (PGF(2alpha)) until the beginning of the first (Group I, n = 3) or second estrous cycle (Group II, n = 2). All mares aborted 3 to 4 d after the first injection; they displayed estrus 2 to 6 d after this injection. As determined by palpation per rectum and serum progesterone levels, each estrus was accompanied by an ovulation. Endometrial cups did not regress after PGF(2alpha) treatment since serum samples from the mares contained pregnant mare serum gonadotropin (PMSG) for at least 30 d after first injection, as determined by mare immunopregnancy test. After the first estrus, two of three mares in Group I displayed a prolonged diestrus (> 25 d). In contrast, the first estrous cycle was short (8 to 12 d) for mares in Group II. Serum progesterone levels in the first 6 d postovulation were lower (P < 0.05) for Group II than for Group I, indicating that formation of the corpus luteum was impaired by daily injections of PGF(2). Results indicate that 1) daily injections of PGF(2alpha) can induce abortion in mares at Day 42 of pregnancy, 2) abortion is followed by estrus and ovulation, 3) the endometrial cups do not regress as a result of this treatment, and 4) daily injections of PGF(2) can impair early corpus luteum development.     

Ginger extract attenuates labetalol induced apoptosis,DNA damage,histological and ultrastructural changes in the heart of rat fetuses

Labetalol is a medication used to treat maternal hypertension during pregnancy. However, it is often associated with many side effects. Recently, several studies have been focused on the protective effect of medicinal plant extracts, such as ginger, against drugs inducing toxicity. Therefore, it has been hypothesized that ginger aqueous extraction can ameliorate labetalol-induced histological, ultrastructural changes, DNA damage, and apoptosis in fetal heart tissue. To achieve the aim of this study, sixty pregnant female albino rats were divided into 4 groups (15 each). Group I (Control). Group II received ginger (200 mg/kg). Group III received labetalol (300 mg/kg). Group IV received labetalol first followed by ginger. All groups were orally injected daily during the organogenesis phase of gestation i.e., from the 6th to the 15th day, and sacrificed at the 20th day of gestation. Results showed that labetalol-induced marked histological and ultrastructural alterations. Also, there was severe DNA damage and an increase in the apoptotic rates determined by Annexin-V/PI dual staining assay. Injection of the ginger aqueous extract caused evident improvement in cardiac tissue, DNA damage, and apoptotic rates. In conclusion, the results suggest that ginger extract could be a potential candidate agent for reducing labetalol-induced cardiotoxicity in the fetal heart of albino rats.     

Luteolytic action of 15-keto prostaglandin F2α in the rhesus monkey

The naturally-occurring metabolite of prostaglandin F_2α, 15-keto prostaglandin F_2α (15-keto PGF_2α), elicited rapid and sustained declines in serum progesterone concentrations when administered to rhesus monkeys beginning on day 22 of normal menstrual cycles. Evidence for luteolysis of a more convincing nature was obtained in studies where a single dose of 15-keto PGF_2α was given on day 20 of ovulatory menstrual cycles in which intramuscular injections of hCG were also given on days 18–20; serum progesterone concentrations fell precipitously in monkeys within 24 hours following intramuscular administration of 15-keto PGF_2α. However, corpus luteum function was impaired in only 4 of 11 early pregnant monkeys when 15-keto PGF_2α was administered on days 30 and 31 from the last menses, a time when the ovary is essential for the maintenance of pregnancy. Gestation failed in 2 additional monkeys 32 and 60 days after treatment with 15-keto PGF_2α, but progressed in an apparently normal manner in the remaining 5 animals. Two pregnant monkeys treated with 15-keto PGF_2α on day 42 from the last menstrual period, a time when the ovary is no longer required for gestation, continued their pregnancies uneventfully. Corpus luteum function was not impaired in 9 control monkeys which received injections of vehicle or hCG at appropriate times during the menstrual cycle or pregnancy.     

Inhibition of uterine prostaglandin-F2α production by bovine conceptus secretory proteins

The effect of bovine conceptus secretory proteins (CSP) on uterine prostaglandin (PG)-F_2α production was evaluated in dairy cattle following injection of estradiol-17β. Intrauterine injections of dialyzed serum proteins (Control, n=5) or CSP (n=5) were administered from days 15 through 18 post-estrus. Following intrauterine treatments on day 18, all cows were injected with E₂ (3 mg) to stimulate uterine PGF_2α production. Plasma concentrations of progesterone (P₄) and 15-keto-13,14-dihydro-PGF_2α (PGFM) were determined by RIA. The PGFM responses following E₂ challenge were decreased (p<0.01) for cows receiving CSP versus serum proteins into the uterine lumen. Individual PGFM, P₄ and cycle length responses are discussed. Data suggest that proteins secreted by the bovine conceptus suppress uterine PGF_2α production during pregnancy recognition in the cow.     

Raised serum human chorionic gonadotrophin concentrations in hyperemesis gravidarum.

Serum human chorionic gonadotrophin (HCG) concentrations were determined by radioimmunoassay with an antiserum specific to HCG beta-subunit in 42 patients with hyperemesis gravidarum and 115 women with normal pregnancies. Mean concentrations (+/- SE of mean) were higher in the women with hyperemesis gravidarum at 7-8 weeks (40.8 +/- 5.2 IU/ml v 22.1 +/- 1.4 IU/ml; P less than 0.001), 9-11 weeks (38.1 +/- 2.3 IU/ml v 27.1 +/- 2.1 IU/ml; P less than 0.0025), and 12-14 weeks of gestation (35.9 +/- 4.2 IU/ml v 25.1 +/- 1.7 IU/ml; P less than 0.005), but there was no difference between the two groups at 15-20 weeks of gestation. In the hyperemesis gravidarum group primigravid women had a higher (P less than 0.005) mean HCG concentration (41.8 +/- 4.0 IU/ml) than multigravid women (32.2 +/- 2.3 IU/ml). The results suggest a causal relation between a high serum HCG concentration and hyperemesis gravidarum.     

Role of the nongravid part of the uterus in the luteolytic effects of estrogen in pregnant rats

Effects of a low dose of estradiol on the luteal function were studied in intact pregnant rats. The pregnant rats received daily sc injections of 0.1 microgram estradiol or sesame oil from day 7 to 14 of pregnancy (day 1 = day of insemination). Serum progesterone levels on day 15 were significantly lower in the estrogen-treated group than in the oil-treated group. In order to study how estrogen induced luteolysis, the pregnant rats received each of the following treatments on day 7 of pregnancy: (1) The uterus except that containing a single conceptus was removed by hysterectomy (hysterectomy group); (2) All but a single conceptus were removed by aspiration, so that rats carried only a single conceptus with the whole part of the nongravid uterus (aspiration group). Each group of rats received also sc injections of 0.1 microgram estradiol or sesame oil from day 7 to 14 of pregnancy. Estradiol treatment caused a significant decline in serum progesterone levels in the aspiration group on day 15, but this was not the case in the hysterectomy group. There was no significant difference in serum LH levels among any of the groups on day 15 of pregnancy. These results indicated that estradiol induced luteolysis in the intact pregnant rats, which would, at least in part, be mediated through the uterus.     

Effect of prostaglandin F2 alpha on the secretion of human prolactin

This study examines the role of PGF2a (prostaglandin F2alpha) in increasing the secretion rate of human prolactin. 11 women (mean gestational period, 18 weeks) seeking pregnancy termination were divided into 4 groups: 1) Group 1 consisted of 6 women who received 30 mg initially of PGF2a injected intramuscularly and an additional 15 mg after 24 hours if abortion had not occured; mean induction to termination period was 38 hours; 2) Group 2 comprised of 3 women who received PGF2a (500-1500 ug) via the transcervical route at 1 to 2 hourly interval; average number of injections was 20; mean induction to termination period, 24 hours; 3) Group 3 had 2 women receiving hypertonic saline by intraamniotic injection; mean induction to termination period was 51 hours; 4) Group 4 had 4 women who served as controls; mean observation period, 20 hours. Venous blood samples were heparinized in tubes at intervals of 2 to 3 hours. A homologous radioimmunoassay using highly purified human prolactin (for iodination and standards) plus rabbit antihuman prolactin measured serum prolactin. Spikes of serum prolactin up to 550 ng/ml were observed at irregular intervals in 5 women in Group 1; the spikes were less frequent and of smaller amplitude in Groups 3 and 4. The increase in serum prolactin was dramatic and more sustained in Group 2 patients and peaked towards the end of the prostaglandin infusion. Serum prolactin of Group 2 patients were significantly higher than those of Groups 3 and 4 (p0.01). 5 of 9 women whose pregnancies were terminated by PGF2a lactated. However, there was no significant difference between the mean serum prolactin levels in women who lactated (136 ng/ml) and those who did not (120 ng/ml). Although PGF2a is not a lactogenic hormone, this study shows that PGF2a stimulates the secretion of human prolactin during second trimester pregnancy. The fact that the transcervical route caused a significant increase in serum prolactin and the intraamniotic route did not is attributed to the increased systemic absorption of PGF2a following transcervical administration. No correlation was seen between the presence or absence of lactation and the serum prolactin level following pregnancy termination with PGF2a.     

Luteolytic action of 15-keto prostaglandin F2alpha in the rhesus monkey.

The naturally-occurring metabolite of prostaglandin F2alpha, 15-keto prostaglandin F2alpha (15-keto PGF2alpha), elicited rapid and sustained declines in serum progesterone concentrations when administered to rhesus monkeys beginning on day 22 of normal menstrual cycles. Evidence for luteolysis of a more convincing nature was obtained in studies where a single dose of 15-keto PGF2alpha was given on day 20 of ovulatory menstrual cycles in which intramuscular injections of hCG were also given on days 18-20; serum progesterone concentrations fell precipitously in monkeys within 24 hours following intramuscular administration of 15-keto PGF2alpha. However, corpus luteum function was impaired in only 4 of 11 early pregnant monkeys when 15-keto PGF2alpha was administered on days 30 and 31 from the last menses, a time when the ovary is essential for the maintenance of pregnancy. Gestation failed in 2 additional monkeys 32 and 60 days after treatment with 15-keto PGF2alpha, but progressed in an apparently normal manner in the remaining 5 animals. Two pregnant monkeys treated with 15-keto PGF2alpha on day 42 from the last menstrual period, a time when the ovary is no longer required for gestation, continued their pregnancies uneventfully. Corpus luteum function was not impaired in 9 control monkeys which received injections of vehicle or hCG at appropriate times during the menstrual cycle or pregnancy.     

Preoperative dilatation of the cervix by single vaginal administration of 15-methyl-PGF2alpha-methyl ester.

Two different vaginal suppositories have been developed suitable for one single treatment for preoperative dilatation of the cervix prior to vacuum aspiration in late first trimester abortion. The study included 60 patients equally distributed in one control group (Group I) where vacuum aspiration was performed without pretreatment; one group (Group II) where the patients obtained 2.0 mg 15-methyl-PGF2alpha-methyl ester in a rapid releasing base six hours prior to operation and one group (Group III) where the prostaglandin dose was increased to 2.5 mg 15-methyl-PGF2alpha-methyl ester and a more slow releasing base was used and the operation performed after 12 hours. The mean cervical dilatation at operation was in Group II 9 mm and in Group III 11 mm in comparison with 4.8 mm in the control group. The bleeding at the operation was also significantly reduced.     

Peripheral progesterone levels in pregnant and non-pregnant heifers following use of HCG.

Progesterone concentration in jugular blood of bred beef heifers was determined on days 9 and 16 in two trials. Human chorionic gonadotrophin (HCG) was administered to some of the heifers in each trial in an attempt to improve pregnancy percentage.In Trial 1, 183 heifers were divided into a control group and three groups of animals which were subjected to a 9-day estrous synchronization treatment prior to breeding. The treatment consisted of an ear implant containing 17 α acetoxy-11-beta-methyl 17 nor preg 4-ene 3, 20 dione (norgestomet) left in place for 9 days and an injection of 5 mg estradiol valerate (EV) and 3 mg of norgestomet given at the time of implantation. The heifers in one group received .25 mg estradiol-17β at time of implant removal; heifers in the 2nd group received 1500 IU of HCG in 5% beeswax and 95% sesame oil at breeding time, while heifers in the 3rd group received a placebo injection containing 5% beeswax and 95% sesame oil at breeding time. No differences in serum levels of progesterone were observed (P>0.5) between treatments or between pregnant and non-pregnant heifers on day 9 or 16 (P>.05). Pregnancy percentage in heifers receiving HCG was similar to that noted in the control heifers or the placebo injected heifers while injection of estradiol 17β decreased the proportion of heifers which became pregnant.In trial 2, 58 heifers which had been bred 1 or 2 times without becoming pregnant were divided into a control group and a group in which heifers received 1000 IU of HCG 96 hr. after observed estrus. In heifers receiving HCG, serum levels of progesterone were higher (P<.01), on day 9 and 16 post estrus than in controls but no difference in serum progesterone was noted (P>.05) between pregnant and non-pregnant heifers on day 9 or 16. The proportion pregnant did not differ (P>.05) between heifers receiving HCG and control heifers.     

Pregnancy and interferon tau regulate major histocompatibility complex class I and beta2-microglobulin expression in the ovine uterus

Major histocompatibility complex (MHC) class I molecules, consisting of an alpha chain and beta2-microglobulin (beta2MG), play an important role in immune rejection responses by discriminating self and nonself and are increased by type I interferons during antiviral responses. Interferon tau (IFNtau), the pregnancy-recognition signal in ruminants, is a type I interferon produced by the ovine conceptus between Days 11 and 21 of gestation. In study 1, expression of MHC class I alpha chain and beta2MG mRNA and protein was detected primarily in endometrial luminal epithelium (LE) and glandular epithelium (GE) on Days 10 and 12 of the estrous cycle and pregnancy. On Days 14-20 of pregnancy, MHC class I and beta2MG expression increased only in endometrial stroma and GE and, concurrently, was absent in LE and superficial ductal GE (sGE). Although neither MHC class I nor beta2MG proteins were detected in Day 20 trophectoderm, beta2MG mRNA was detected in conceptus trophectoderm. In study 2, cyclic ewes were ovariectomized on Day 5, treated daily with progesterone to Day 16, received intrauterine infusions between Days 11 and 16 of either control serum proteins or recombinant ovine IFNtau, and were hysterectomized on Day 17. The IFNtau increased MHC class I and beta2MG expression only in endometrial stroma and GE. During pregnancy, MHC class I and beta2MG gene expression is inhibited in endometrial LE and sGE but, paradoxically, is stimulated by IFNtau in the stroma and GE. The silencing of MHC class I alpha chain and beta2MG genes in the endometrial LE and sGE during pregnancy recognition and establishment may be a critical mechanism preventing immune rejection of the conceptus allograft.     

Lack of a co-promotion effect of 60 Hz rotating magnetic fields on N-ethyl-N-nitrosourea induced neurogenic tumors in F344 rats

The present study was conducted to investigate the possible effect of 60 Hz magnetic fields as promoters of brain tumors initiated transplacentally by ethylnitrosourea (ENU) in F344 rats. One hundred twenty mated animals were divided into six different groups and exposed in utero on day 18 of gestation to a single intravenous dose of either Saline (vehicle control, Group I), or ENU 10 mg/kg (Groups II-VI). In the present study, a total of 480 offspring was used. The offspring in group II were given no further treatment while the offspring in Groups III-VI were exposed to four different intensities of magnetic fields. Animals received exposure to 60 Hz magnetic field at field strengths of 0 Tesla (sham control, T1, Group III), 5 muT (T2, Group IV), 83.3 muT (T3, Group V), or 500 muT (T4, Group VI), for 21 h/day from the age of 4 weeks to the age of 32 or 42 weeks. At histopathological examination, tumors of the nervous system were seen in all the ENU-treated groups. The tumor incidence of the ENU group at 32nd and 42nd week necropsy was higher than that of the vehicle control group. The incidence of glial tumors at 42nd week necropsy was higher than the 32nd week necropsy. However, there were no differences in the tumor incidence between the sham control (T1) and ENU + magnetic field exposure groups (T2-T4). In conclusion, there was no evidence that exposure of offspring to 60 Hz at magnetic field strengths up to 500 muT to the age of 32 or 42 weeks promoted ENU-initiated brain tumors in rats.     

Antibodies against oxidized low density lipoproteins in pregnant women

Oxidized low density lipoproteins (oxLDL) formed in vivo induce a humoral immune response. Oxidative modification of LDL renders it immunogenic and a heterogeneous population of specific anti-oxLDL antibodies is produced. These antibodies could represent a biological marker of oxidative stress and serve as markers of atherosclerosis. Autoantibodies against oxLDL (oLAb) have been detected in human subjects practically of every age. oLAb also appear in the blood of pregnant women. Some studies have shown that the levels of antibodies to oxLDL were elevated in women with established preeclampsia. The present study was aimed to estimate the oLAb IgG levels in the first and second trimester of pregnancy. Furthermore, we estimated the correlation between maternal serum (MS) levels of oLAb and alpha-1-fetoprotein (MS AFP), human chorionic gonadotrophin (MS HCG) and trophoblast-specific-beta-1-glycoprotein (MS SP1), because these proteins are determined as a part of prenatal biochemical screening for fetal congenital abnormalities. Our study deals with the oLAb changes in women with pregnancy-induced hypertension. We also investigated the correlation between oLAb IgG and anticardiolipin antibodies IgG (ACA) in the serum of pregnant women. We examined 40 pregnant women attending Institute for Mother and Child Care for their antenatal care as outpatients. Routine blood samplings between the 9-13th week of pregnancy and 16-18th week of pregnancy were performed as a part of biochemical prenatal screening for fetal congenital abnormalities (Group 1). Their mean age was 27 +/- 4.1 years. Furthermore, we examined 26 women in the second or third trimester with pregnancy-induced hypertension (Group 2). Group 2 was compared with 49 pregnant women in the second or third trimester who were normotensive (Group 3). We used commercial standardized ELISA kits for determination of oLAb IgG, ACA IgG, MS AFP and MS HCG, MS SP1 was analyzed by single radial immunodiffusion. We did not find any differences in the levels of oLAb IgG in the first and second trimester in the women of Group 1. The correlation between oLAb and ACA IgG was not statistically significant (Spearman coefficient r=0.22, p=0.1). The correlation between oLAb IgG with MS AFP, MS HCG and MS SP1 was not statistically significant. Weak negative correlation for AFP and HCG was suggested both in the first and in the second trimester. The levels of oLAb IgG in the group of women with pregnancy-induced hypertension were significantly lower than in the group of normotensive women (348 +/- 388 U/ml v.s. 579 +/- 400 mU/ml, p<0.01). We can conclude that the levels of oLAb do not differ in the first and second trimester of gravidity. However, we cannot exclude the possible influence of an inverse relationship between oLAb IgG titers and the synthesis of fetoplacental antigens. This finding is important especially in the context of the results of prenatal biochemical screening. Pregnancy-induced hypertension is associated with lower levels of oLAb. Weak cross-reactivity between oLAb and anticardiolipin antibodies may exist but there is a possibility that there are two different populations of antibodies reacting with various antigens.     

Effect of in vivo prostaglandin treatment on H-PGF2α uptake in hamster corpora lutea

Pregnant hamsters were administered (SC) prostaglandin or vehicle on the morning of the 4th day of pregnancy. Serum progesterone was significantly depressed (p<.01) at 0.5, 2, and 6 hours after treatment with 100 μg PGF_2α. Serum progesterone levels were unchanged 2 hours and 6 hours after treatment with 100 μg PGF_2β and 2 hours after treatment with 1 mg PGF_2β. Progesterone levels were depressed to less than 1 ng/ml 6 hours after treatment with 1 mg PGF_2β. The specific uptake of ³H-PGF_2α in whole hamster corpora lutea was significantly depressed 2 hours and 6 hours following 100 μg PGF_2α treatment. A 15% depression in specific uptake occurred 0.5 hour post-treatment. Treatment with 100 μg PGF_2β resulted in no change. Administration of 1 mg PGF_2β resulted in depressed ³H-PGF_2α uptake at both 2 and 6 hours post-treatment.Prostacyclin (PGI₂) treatment resulted in no change in either ³H-PGF_2α specific uptake or serum progesterone 2 hours after 100 μg treatment SC. These parameters were both reduced approximately 30% 6 hours post-treatment. Treatment with 6-keto-PGF_1α resulted in a complete lack of measurable ³H-PGF_2α uptake and serum progesterone levels less than 1 ng/ml at both 2 and 6 hours after treatment with 1 mg SC.     

Growth,feed intake and immune responses of orange-spotted grouper (Epinephelus coioides) exposed to low infectious doses of ectoparasite (Cryptocaryon irritans)

To explore the effect of low-dose Cryptocaryon irritans infection on growth, feeding and antiparasitic immunity of orange-spotted grouper (Epinephelus coioides), this study utilized C. irritans at concentrations of 5500 theronts/fish (Group I, 1/10 of 96 h LC50) or 11,000 theronts/fish (Group II) to infect E. coioides weighing 38 g on average at week 0, 2 and 4, respectively. Food consumption was recorded daily; the fish were weighed weekly; serum immobilizing titer (SIT), and acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), lysozyme (LZM) activity were recorded every 2 weeks; the fish were treated with lethal dose (70,000 theronts/fish) of C. irritans in the 8th week and death number were recorded. The result shows that in the 1st week after the first infection, the fish's weight gain (WG), length gain (LG), and specific growth rate (SGR) dropped as parasite dose increased, and WG, SGR values were negative; while, after the 2nd and the 3rd infection, no significant differences were detected among the three groups. These results indicated that the 1st infection affected the fish most, while the following infections were protected by some immunity. In the 3rd, 7th, and 8th week, condition factor (CF) increased with the increased infectious dose, indicating that the parasite affected body length more than body weight. As the experiment went on, accumulated food consumption (AFC) of all three groups steadily grew (control > Group I > Group II). But on the 2nd day after the first infection, daily food consumption (DFC) of Group I and II significantly dropped, the decline of Group II was greater than that of Group I, DFC recovered in the following week, with Group I earlier than Group II. After the 2nd infection, DFC of Group I and II dropped again, Group II still dropped more than Group I, and both groups recovered on the 3rd day after infection. The 3rd infection caused no significant difference in week food consumption (WFC). These results indicated that a higher dose of infection causes a greater drop in FC and a slower recovery. Weekly feed conversion ratio (WFCR) values of Group I and II in the 1st week was negative; in the 2nd week, WFCR was lower in the group infected by a higher dose of parasite; while in the 3rd and following weeks, no significant pattern was observed. Accumulate feed conversion ratio (AFCR) dropped as the infectious dose increased (control > Group I > Group II), AFCR of Group I and II reached above 0 in the 2nd and 4th week, respectively. From the 4th week on, the inter-group AFCR of the 3 groups still took on a declining trend with the increased infectious dose but the gap became smaller. One week after the first infection, SIT of Group I and Group II were 0; one week after the 2nd infection, SIT reached up to 8 (Group I) and 16 (Group II) respectively; and after the 3rd infection, SIT further increased and peaked in the 7th week. When challenged by lethal dose of C. irritans, fish of all 3 groups began to die since the 3rd day after infection, and the final deaths were 14, 12 and 8 for the control group, Group I and Group II, respectively. ACP activity in the 1st, 5th, 7th but the 3rd week was higher in the experiment group than that in the control group, but no significant difference was detected between Group I and II throughout the experiment. AKP activity increased as the infectious dose increased, but the difference among the three groups gradually became less obvious in latter infections, and no significant difference can be detected in the end. SOD activity increased with infection dose at each time point, while both group I and group II had their SOD activities first increased and then decreased as times of infection increased. The LZM activity of the two infection groups increased as the infectious times increased. Combining the results on growth and feeding, we speculated that the fish's physiological condition stabilized after 3 rounds of infection. To sum up, low-dose infection by C. irritans can induce the fish's immunity, but at the cost of decreasing food intake, decreased food conversion, and lagged growth.     

Termination of pregnancy in cats with prostaglandin F2α

Two subcutaneous injections of Prostaglandin F_2α THAM salt 24 hours apart terminated pregnancies in cats after the 40th day of gestation. Injections of 0.50 or 1.00 mg. PGF_2α THAM salt/Kg. body weight were the most effective in terminating pregnancies. Parturition or abortion occurred within 24 hours after the initial injection in 9 cats and after the 2nd injection in 4 cats.