Immunogenicity, Lot Consistency, and Extended Safety of rVSVΔG-ZEBOV-GP Vaccine: A Phase 3 Randomized, Double-Blind, Placebo-Controlled Study in Healthy Adults

BACKGROUND

This double-blind study assessed immunogenicity, lot consistency, and safety of recombinant vesicular stomatitis virus-Zaire Ebola virus envelope glycoprotein vaccine (rVSVΔG-ZEBOV-GP).

METHODS

Healthy adults (N = 1197) were randomized 2:2:2:2:1 to receive 1 of 3 consistency lots of rVSVΔG-ZEBOV-GP (2 × 107 plaque-forming units [pfu]), high-dose 1 × 108 pfu, or placebo. Antibody responses pre-/postvaccination (28 days, 6 months; in a subset [n = 566], months 12, 18, and 24) were measured. post hoc analysis of risk factors associated with arthritis following vaccination was performed.

RESULTS

ZEBOV-GP enzyme-linked immunosorbent assay (ELISA) geometric mean titers (GMTs) increased postvaccination in all rVSVΔG-ZEBOV-GP groups by 28 days (>58-fold) and persisted through 24 months. The 3 manufacturing lots demonstrated equivalent immunogenicity at 28 days. Neutralizing antibody GMTs increased by 28 days in all rVSVΔG-ZEBOV-GP groups, peaking at 18 months with no decrease through 24 months. At 28 days, ≥94% of vaccine recipients seroresponded (ZEBOV-GP ELISA, ≥2-fold increase, titer ≥200 EU/mL), with responses persisting at 24 months in ≥91%. Female sex and a history of arthritis were identified as potential risk factors for the development of arthritis postvaccination.

CONCLUSIONS

Immune responses to rVSVΔG-ZEBOV-GP persisted to 24 months. Immunogenicity and safety results support continued rVSVΔG-ZEBOV-GP development.

CLINICAL TRIALS REGISTRATION

NCT02503202.

Evaluation of immunogenicity and safety of VARIVAX™ New Seed Process (NSP) in children

Prior to availability of an effective vaccine, an estimated 4 million cases of varicella occurred annually in the United States, resulting in 10,000 hospitalizations and over 100 deaths. With the increased usage of a two-dose varicella vaccine (as recommended by the ACIP), approval of other VZV-containing products and the adoption of varicella vaccination in additional countries, the demand for VZV-containing vaccines has increased. This study (NCT02062502) evaluated the safety, tolerability, and immunogenicity of VARIVAX™ (VAR, varicella vaccine live) manufactured using a new seed manufacturing process (VAR_NSP) compared to the currently licensed VAR. Healthy children 12-23 months were randomized (1:1) into Group 1 (2 doses of VAR_NSP given concomitantly with M-M-R™ II, ∼3 months apart) versus  Group 2 (2 doses of VAR given concomitantly with M-M-R™ II, ∼3 months apart).  Serum samples collected prior to vaccination on Day 1 and 6 weeks Postdose 1 were tested for antibody to VZV using a glycoprotein enzyme-linked immunosorbent assay (gpELISA).  Safety was assessed Days 1 to 42 following each vaccination. Six weeks Postdose 1, the response rate (percent of subjects with VZV antibody titer ≥5 gpELISA units/mL) of VAR_NSP was non-inferior compared to VAR.  Vaccine-related adverse events (AEs) were comparable with the exception of measles-like rash, where a greater number of rashes were observed with VAR than VAR_NSP.  The 2 vaccination groups were comparable with incidence rates of AEs, injection-site AEs, vaccine-related AEs, systemic AEs, and serious AEs. This new process is an important innovation for the extreme demand of sustaining sufficient supplies of varicella vaccine to protect our communities against diseases caused by VZV.

Six-Month Safety Data of Recombinant Vesicular Stomatitis Virus-Zaire Ebola Virus Envelope Glycoprotein Vaccine in a Phase 3 Double-Blind, Placebo-Controlled Randomized Study in Healthy Adults

Background

This study (NCT02503202) evaluated the safety of recombinant vesicular stomatitis virus-Zaire Ebola virus envelope glycoprotein vaccine (rVSVΔG-ZEBOV-GP).

Methods

Overall, 1197 subjects were randomized 2:2:2:2:1; 1194 were vaccinated with 1 dose of 1 of 3 lots of rVSVΔG- ZEBOV-GP (2 × 107 plaque-forming units [pfu], n = 797; combined-lots group), a single high-dose lot of rVSVΔG-ZEBOV-GP (1 × 108 pfu, n = 264; high-dose group), or placebo (n = 133). Daily temperatures and adverse events (AEs) were recorded days 1 to 42 postvaccination. Solicited AEs included injection-site AEs from days 1 to 5, and joint pain, joint swelling, vesicular lesions (blisters), and rashes from days 1 to 42. Serious AEs (SAEs) were recorded through 6 months postvaccination.

Results

Fever (≥38.0°C) was observed in 20.2% of combined lots (3.2% with ≥39.0°C), 32.2% of high-dose (4.3% with ≥39.0°C), and 0.8% of placebo (0.8% with ≥39.0°C). Incidences of AEs of interest (days 1-42) were arthralgia (17.1% combined lots, 20.4% high-dose, 3.0% placebo), arthritis (5.1% combined lots, 4.2% high-dose, 0.0% placebo), and rash (3.8% combined lots, 3.8% high-dose, 1.5% placebo). Twenty-one SAEs and 2 deaths were reported, all assessed by investigators as unrelated to vaccine.

Conclusions

rVSVΔG-ZEBOV-GP was generally well-tolerated, with increased rates of injection-site and systemic AEs compared to placebo, and no vaccine-related SAEs or deaths. These findings support the use of rVSVΔG-ZEBOV-GP vaccine in persons at risk for Ebola virus disease.

Clinical Trials Registration

NCT02503202.

A double blind, randomized, active controlled study to assess the safety, tolerability and immunogenicity of measles, mumps rubella, and varicella vaccine (MMRV) manufactured using an alternative process

Vaccination against measles, mumps, rubella, and varicella is recommended for all children in the US. Limitations manufacturing Oka/Merck strain varicella-zoster virus have hampered the availability of the combination vaccine (MMRV) against these 4 viruses, which drove the need to investigate an alternative manufacturing process. Healthy children 12-to-23 months of age at 71 US sites were randomized (1:1) to receive MMRV manufactured using an alternative process (MMRV_AMP) or the currently licensed MMRV. Subjects received 2 0.5 mL doses 3 months apart. Sera were collected before and 6 weeks after Dose-1. Adverse experiences (AEs) were collected for 42 d after each dose and serious AEs and events of special interest for 180 d after Dose-2. Overall, 706 subjects were randomized to MMRV_AMP and 706 to MMRV and 698 and 702 received at least 1 dose of study vaccine, respectively. The risk difference in response rates and geometric mean concentrations of antibody to measles, mumps, rubella, and varicella viruses 6 weeks after Dose-1 met non-inferiority criteria for MMRV_AMP versus, MMRV. Response rates met acceptability criteria for each virus, and the seroconversion rate to varicella-zoster virus was 99.5% in both groups. Vaccine-related AEs were mostly mild-to-moderate in intensity and somewhat more common after MMRV_AMP. Febrile seizures occurred at similar rates in both groups during the first 42 d after each vaccine dose. MMRV_AMP is non-inferior to MMRV and represents an important advancement in maintaining an adequate supply of vaccines against these diseases.

Boceprevir plus peginterferon/ribavirin for treatment of chronic hepatitis C in Russia

AIM: To evaluate addition of boceprevir to peginterferon/ribavirin (PR) in Russian patients with chronic hepatitis C virus (HCV).

METHODS: Treatment-naive (TN) and treatment-experienced (TE) patients (who had failed prior treatment with PR for ≥ 12 wk) with chronic HCV genotype 1 infection were enrolled in this placebo-controlled, double-blind study. All patients initially received PR for 4 wk. Patients randomized to control treatment then received PR for an additional 44 wk. TN patients randomized to triple therapy received boceprevir (800 mg three times daily) plus PR for 24 wk and then further therapy according to treatment week 8 (TW8) HCV RNA levels. TE patients received boceprevir plus PR for 32 wk and then further therapy according to TW8 HCV RNA levels. Treatment was discontinued for TN patients with detectable HCV RNA at TW24 and TE patients with detectable HCV RNA at TW12 because of futility. The primary efficacy end point was sustained virologic response (SVR) defined as undetectable HCV RNA 24 wk after completing all study therapy.

RESULTS: SVR was 74.8% in the boceprevir plus PR arm compared with 46.2% in the control arm, with a stratification-adjusted treatment difference of 29.2% (95%CI: 16.4-41.5; P < 0.0001). Rates of SVR were higher in the boceprevir arm in both TN and TE patient groups (TN 78.4% vs 56.3%; TE 69.4% vs 30.0%). Within TE patients, the rates of SVR were higher with boceprevir plus PR compared with PR, regardless of treatment failure type (null responder, partial responder, and relapser). Most patients receiving boceprevir plus PR in both TN (86%) and TE (71%) populations were eligible for reduced treatment duration. Anemia was increased in patients receiving boceprevir plus PR vs PR alone (47.2% vs 24.4%); there was a corresponding increase in ribavirin dose reduction and erythropoietin use. Among patients receiving boceprevir plus PR, SVR rates were similar in patients with anemia (< 10 g/dL) and those without anemia (71.2% vs 77.4%).

CONCLUSION: Regulatory approval has been obtained for boceprevir plus PR in Russian patients with HCV genotype 1 infection based on the results of this study.

Overall safety profile of boceprevir plus peginterferon alfa-2b and ribavirin in patients with chronic hepatitis C genotype 1: a combined analysis of 3 phase 2/3 clinical trials

BACKGROUND & AIMS

Triple therapy with peginterferon/ribavirin (PR) plus an NS3 protease inhibitor has emerged as the standard-of-care for patients with chronic hepatitis C genotype-1. We provide a detailed safety analysis comparing PR to boceprevir plus PR (BOC/PR) across three phase 2/3 studies.

METHODS

SPRINT-1 was an open-label phase 2 study in 595 treatment-naive patients. In the two phase 3 studies, 1500 patients (1097 treatment-naive, SPRINT-2; 403 treatment-failure, RESPOND-2) were randomized to receive PR alone, or one of two regimens where BOC was added to PR after a 4-wk PR lead-in. In this analysis, the respective BOC/PR and PR arms were combined for all three trials. The benefit of shortened duration of treatment using response-guided therapy (RGT) was also explored in the SPRINT-2 trial.

RESULTS

Only two adverse events, anaemia and dysgeusia, occurred 20% more often with the BOC-containing regimens compared with PR. Nausea, diarrhoea and neutropenia were the only other common events with an incidence of at least 5% greater when BOC was added to the PR backbone. The proportions of patients reporting serious adverse events (AE), life-threatening AEs, and study drug discontinuation because of an AE were similar in the PR and BOC/PR arms. In treatment-naive patients, RGT generally did not result in a lower frequency of common AEs; however, RGT led to decreased exposure to all 3 study drugs and to a decrease in the mean duration of several clinically relevant AEs such as anaemia, neutropenia, fatigue and depression, as well as earlier normalization of haemoglobin and neutrophil counts.

CONCLUSIONS

The safety profile of BOC combination therapy largely reflects the known profile of peginterferon and ribavirin, with incremental haematolgical effects and dysgeusia. Shorter treatment duration with RGT significantly reduced the duration of AEs.

Boceprevir for chronic HCV genotype 1 infection in patients with prior treatment failure to peginterferon/ribavirin, including prior null response

BACKGROUND & AIMS

Boceprevir with peginterferon/ribavirin (BOC/PR) leads to significantly higher sustained virological response (SVR) rates in patients with chronic hepatitis C and partial response or relapse after prior treatment with peginterferon/ribavirin. We studied the efficacy of BOC/PR in patients with prior treatment failure, including those with a null response (<2-log10 decline in HCV RNA), to peginterferon/ribavirin.

METHODS

Patients in the control arms of boceprevir Phase 2/3 studies who did not achieve SVR were re-treated with BOC/PR for up to 44 weeks. Patients enrolling >2 weeks after end-of-treatment in the prior study received PR for 4 weeks before adding boceprevir.

RESULTS

Of 168 patients enrolled, four discontinued from the PR lead-in and 164 received BOC/PR. Baseline viral load was >800,000 IU/ml in 77% of patients; 62% had HCV genotype 1a, and 10% were cirrhotic. In the ITT analysis (all 168 patients), SVR was achieved in 20 (38%) of 52 patients with prior null response, 57 (67%) of 85 with prior partial response, and 27 (93%) of 29 with prior relapse. In the mITT analysis (164 BOC/PR-treated patients), SVR rates were 41% (20/49), 67% (57/85), and 96% (27/28), respectively. SVR was achieved by 48% of patients with <1-log10 decline in HCV-RNA after lead-in and 76% of those with ⩾ 1-log10 decline or undetectable HCV-RNA after lead-in. The most common adverse events were anemia (49%), fatigue (48%), and dysgeusia (35%); 8% of patients discontinued due to adverse events.

CONCLUSIONS

Re-treatment with BOC/PR improved SVR rates in all patient subgroups, including those with prior null response.

PET imaging of steroid receptor expression in breast and prostate cancer

The vast majority of breast and prostate cancers express specific receptors for steroid hormones, which play a pivotal role in tumor progression. Because of the efficacy of endocrine therapy combined with its relatively mild side-effects, this intervention has nowadays become the treatment of choice for patients with advanced breast and prostate cancer, provided that their tumors express hormone receptors. However, in case of breast cancer it is well known that part of the patients have hormone receptor-negative tumors at diagnosis, whereas other patients have discordant receptor expression across lesions. In addition, receptor expression can change during therapy and result in resistance to this therapy. Besides several lines of hormonal treatments, also other strategies to affect the hormone receptors are currently under investigation, namely histone deacetylases (HDAC) and heat shock protein (HSP) inhibitors. Knowledge of the actual receptor status can support optimal treatment decision-making and the evaluation of new drugs. Positron emission tomography (PET) is a non-invasive nuclear imaging technique that allows monitoring and quantification of hormone receptor expression across lesions throughout the body. Several PET tracers have been developed for imaging of the most relevant hormone receptors in breast and prostate cancer: i.e. the estrogen, progesterone and androgen receptors. Some of these PET tracers have been successfully applied in early clinical studies. This review will give an overview of the current status of PET imaging of hormone receptors in breast and prostate cancer.

Tibolone histology of the endometrium and breast endpoints study: design of the trial and endometrial histology at baseline in postmenopausal women

OBJECTIVE

To address the endometrial safety of tibolone.

DESIGN

The Tibolone Histology of the Endometrium and Breast Endpoints Study (THEBES) is a randomized, double-blind, parallel-group trial of tibolone compared with continuous combined conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA).

SETTING

Multi-country, multi-center ambulatory care setting.

PATIENT(S)

A total of 5,185 subjects were screened, and biopsies were obtained from 4,446 women.

INTERVENTION(S)

Participants were randomized in a 1:1:2 ratio, to tibolone (1.25 or 2.5 mg/d) or CEE-MPA.

MAIN OUTCOME MEASURE(S)

The one-sided 95% confidence intervals for the incidence of hyperplasia or cancer were evaluated for tibolone compared with CEE-MPA.

RESULT(S)

Endometrial biopsy results at baseline: atrophic (87.29%), inactive (0.25%), proliferative (6.12%), secretory (2.86%), menstrual type (0.40%), and hyperplasia (0.18%). Only subjects with atrophic or inactive endometrium were eligible for this study, and 3% of the women at screening either had no tissue (0.18%) or had an amount of tissue that was insufficient for diagnosis (2.72%). Three thousand two hundred forty postmenopausal women with a mean (+/-SD) age of 54.4 +/- 4.4 years and a mean time since menopause of 4.5 +/- 3.6 years were randomized.

CONCLUSION(S)

The Tibolone Histology of the Endometrium and Breast Endpoints Study is a prospective, randomized clinical trial, designed to provide evidence of the endometrial safety of tibolone compared with estrogen and progestogen. Screening endometrial histology shows a low prevalence of endometrial hyperplasia (0.18%) and no carcinoma.

Endometrial effects of tibolone

BACKGROUND AND OBJECTIVES

The Tibolone Histology of the Endometrium and Breast Endpoints Study is a multicenter, randomized, double-blind study designed to address the conflicting reports in the literature about the endometrial safety of tibolone (1.25 or 2.5 mg/d). Tibolone was compared with continuous combined conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA) (0.625 + 2.5 mg/d).

METHODS

Subjects were randomized in a 1:1:2 ratio to tibolone 1.25 mg/d, 2.5 mg/d, and CEE/MPA, respectively. The one-sided 95% confidence interval (CI) has been evaluated for the incidence of abnormal endometrial histology (hyperplasia or carcinoma) and hyperplasia and carcinoma separately for each of the two treatment groups and the treatment groups combined after 1 and 2 yr of treatment with tibolone, compared with CEE/MPA.

RESULTS

A total of 3240 women were randomized, with 3224 receiving at least one dose of study medication. The incidence and upper one-sided 95% CI for the incidence of abnormal endometrium (hyperplasia or carcinoma), and hyperplasia and carcinoma separately, were calculated at end point, yr 1, and yr 2. The incidence (upper one-sided 95% CI) of abnormal endometrium at end point was 0.0 (0.5), 0.0 (0.4), and 0.2 (0.5) in the tibolone 1.25 mg, 2.5 mg, and CEE/MPA groups, respectively. During the entire treatment period, amenorrhea was reported more frequently with tibolone 1.25 mg (78.7%) and 2.5 mg (71.4%) than CEE/MPA (44.9%).

CONCLUSION

The Tibolone Histology of the Endometrium and Breast Endpoints Study results confirm previous findings that tibolone does not induce endometrial hyperplasia or carcinoma in postmenopausal women, and it is associated with a better vaginal bleeding profile than CEE/MPA.

Effects of tibolone and continuous combined conjugated equine estrogen/medroxyprogesterone acetate on the endometrium and vaginal bleeding: results of the OPAL study

OBJECTIVES

The primary objective of the Osteoporosis Prevention and Arterial effects of tiboLone study was to compare the effect of tibolone and placebo on the progression of the common carotid artery intima-medial thickness; the common carotid artery intima-medial thickness and bone data will be presented elsewhere. A secondary objective was to assess the effects of tibolone (2.5 mg), continuous combined conjugated equine estrogen/medroxyprogesterone acetate [0.625/2.5 mg], and placebo on the endometrium and vaginal bleeding; these results are the subject of this report.

STUDY DESIGN

This 3-year, three-arm, international, randomized, double-blind, parallel group, placebo-controlled clinical trial enrolled 866 postmenopausal women (aged 45-79 years). The endometrium was assessed by annual transvaginal ultrasound scans and end-of-study biopsies (United States/United Kingdom centers only). Vaginal bleeding was recorded in daily diaries.

RESULTS

Endometrial thickness measured by transvaginal ultrasound scan increased slightly during the first year with tibolone and conjugated equine estrogen/medroxyprogesterone acetate, without any further progression. After 3 years, there were no significant differences between the tibolone, conjugated equine estrogen/medroxyprogesterone acetate, and placebo groups in the incidence of proliferation (1.4%, 4.8%, and 0%, respectively), endometrial hyperplasia (0% in all groups), or cancer (1, 0, and 1 case, respectively). During the first 3 months, bleeding/spotting rates were greater with conjugated equine estrogen/medroxyprogesterone acetate (48%) than with tibolone (18%; P < .001) or placebo (3%; P < .001). During 3 years of treatment, the incidence of bleeding/spotting was 66%, 48%, and 23% for conjugated equine estrogen/medroxyprogesterone acetate, tibolone, and placebo, respectively. The mean number of bleeding/spotting days was greater in the conjugated equine estrogen/medroxyprogesterone acetate than the tibolone or placebo groups (61, 28, and 7 days, respectively; P = .023 vs tibolone; P < .0001 vs placebo). The mean number of bleeding/spotting episodes was also greater in the conjugated equine estrogen/medroxyprogesterone acetate group (13 episodes) compared with the tibolone group (six episodes; P < .001) and placebo group (four episodes; P < .001). Vaginal bleeding was more commonly reported as an adverse event with conjugated equine estrogen/medroxyprogesterone acetate than tibolone (26.4% vs 10.8%, P < .0001) and as the reason for premature discontinuation (9% vs 2%, P = .001).

CONCLUSION

Compared with conjugated equine estrogen/medroxyprogesterone acetate, tibolone has a better tolerability profile with respect to vaginal bleeding but with a similar endometrial safety. These results reinforce the endometrial safety profile of tibolone.

Tibolone for the treatment of moderate to severe vasomotor symptoms and genital atrophy in postmenopausal women

OBJECTIVE

To demonstrate the safety and efficacy of tibolone (1.25 and 2.5 mg) in the treatment of moderate to severe vasomotor symptoms and symptoms associated with vaginal atrophy.

DESIGN

A placebo-controlled, double-blind, randomized, multicenter study was conducted on 396 healthy postmenopausal women experiencing a minimum of 7 moderate to severe hot flashes per day (60 per week). Participants were randomized to receive tibolone 1.25 or 2.5 mg or placebo once daily for 12 weeks. Assessments were done at weeks 4, 8, and 12. The severity and frequency of hot flashes were recorded in patient diaries on a daily basis.

RESULTS

Tibolone 2.5 mg significantly (P < 0.001) reduced the average number of hot flashes compared with placebo at week 4 (-7.82 vs -5.27), week 8 (-9.71 vs -5.86), and week 12 (-10.14 vs -5.85). The difference between tibolone 1.25 mg and placebo was significant (P < 0.001) at week 8 (-7.96) and week 12 (-8.32). Findings for the average daily severity of hot flashes were similar, with significantly greater reductions at week 4 (P < 0.05) and weeks 8 and 12 (P < 0.001) for tibolone 2.5 mg versus placebo and at weeks 8 and 12 for tibolone 1.25 mg versus placebo (P < 0.001). A menopausal atrophic symptom questionnaire revealed that tibolone 2.5 mg significantly (P < 0.05) reduced nocturia compared with placebo at weeks 4, 8, and 12 and urinary urgency at week 4. Compared with placebo, both doses of tibolone also significantly (P < 0.001) increased the vaginal maturation value from baseline. The overall incidence of adverse events was similar in all treatment groups.

CONCLUSIONS

Tibolone is effective and well tolerated for the treatment of moderate to severe vasomotor symptoms and the effects of vaginal atrophy associated with menopause.

The effect of tibolone and continuous combined conjugated equine oestrogens plus medroxyprogesterone acetate on progression of carotid intima–media thickness: the Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study

AIMS

At the time of the design of the Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study in 1996, oral hormone therapy (HT) was assumed to reduce cardiovascular risk. The evidence mainly came from the effects of combined conjugated equine oestrogens plus medroxyprogesterone acetate (CEE/MPA) therapy. Other HT regimes had not been studied widely. Tibolone, a selective tissue oestrogenic activity regulator, has several effects on cardiovascular risk factors, one of which is HDL lowering. Because the overall effect of tibolone on cardiovascular risk was unknown, the OPAL study was designed.

METHODS AND RESULTS

The OPAL study was a three-arm, randomized, placebo-controlled, double-blind study to determine the effect of tibolone (2.5 mg daily) and of CEE/MPA (0.625/2.5 mg daily) over 3 years on progression of carotid intima-media thickness (CIMT) in 866 healthy post-menopausal women. The women were recruited from six US and five European centres. The primary outcome was change in mean common CIMT. Annual common CIMT progression rates in the tibolone and CEE/MPA groups were higher than in the placebo group: 0.0077 mm [95% confidence interval (CI) 0.0051-0.0103] in the tibolone group, 0.0074 mm (0.0048-0.0099) in the CEE/MPA group, and 0.0035 mm (0.009-0.0061) in the placebo group. The differences with placebo (0.0042 mm/year for tibolone and 0.0039 mm/year for CEE/MPA) were statistically significant. HDL cholesterol increased in CEE/MPA group and was lowered in the tibolone group.

CONCLUSION

Both tibolone and CEE/MPA showed increased progression of common CIMT. Translation of the increased common CIMT progression of the CEE/MPA group into cardiovascular disease risk could not fully explain the observed increased cardiovascular risk as observed in the Women's Health Initiative study. This suggests that the net effect of tibolone and CEE/MPA on cardiovascular events may depend on the combined effects on the arterial wall, clotting factors, and possibly inflammation.

Tibolone relieves climacteric symptoms in highly symptomatic women with at least seven hot flushes and sweats per day

OBJECTIVE

To establish the potency of four dose levels of tibolone, a tissue selective estrogenic activity regulator (STEAR), to relieve climacteric symptoms in a subgroup of highly symptomatic women experiencing a minimum of seven hot flushes and sweats per day.

METHODS

In a group of 770 women receiving tibolone 0.625, 1.25, 2.5 or 5.0 mg or placebo for 12 weeks, a total of 317 women experienced at least seven hot flushes and sweats per day. Frequency and intensity of climacteric symptoms were assessed at baseline and after 4, 8 and 12 weeks of treatment. Vaginal bleeding/spotting was studied using diary cards. Occurrence of adverse events was determined by active questioning.

RESULTS

Tibolone induced a decrease in the frequency and intensity of climacteric symptoms, leading to statistically significant differences compared to placebo for dose levels of 1.25 mg and higher. The incidence of vaginal bleeding/spotting and of drug-related adverse events was similar in all tibolone dose groups, except for the 5.0 mg group, where the incidence was about twice as high. Dropout rate due to insufficient therapeutic effect is substantially higher in the 0.625 and 1.25 mg group (about 10%) compared to the 2.5 and 5.0 mg group (about 1%). These results are consistent with what occurred in the total study population published previously.

CONCLUSION

The effects of tibolone in highly symptomatic women experiencing at least seven hot flushes and sweats per day do not differ much from that in the total study population. A daily dose of 2.5 mg is the optimal dose for both the total study population and the subgroup of highly symptomatic women. However, in order to optimise individual treatment, the 1.25 mg dose might also be taken into consideration.

The effect of tibolone in postmenopausal women receiving tamoxifen after surgery for breast cancer: a randomised, double-blind, placebo-controlled trial

OBJECTIVE

To assess the effects of tibolone on climacteric symptoms, endometrium and serum lipid/lipoproteins in postmenopausal women receiving tamoxifen after surgery for breast cancer.

DESIGN

Double-blind, randomised, placebo-controlled, multicentre pilot study.

SETTING

Hospital outpatient clinic.

SAMPLE

Seventy postmenopausal women receiving tamoxifen following surgery for early breast cancer.

METHODS

Women received 20 mg/day oral tamoxifen plus either 2.5 mg/day oral tibolone or placebo for 12 months.

MAIN OUTCOME MEASURES

Frequency and severity of hot flushes (diary cards); intensity of hot flushes and sweats (Landgren scale); interference of hot flushes and sweats with normal life; frequency and intensity of other climacteric symptoms; endometrial thickness and histology; vaginal bleeding; breast cancer recurrence and serum lipid/lipoproteins.

RESULTS

Daily card data showed no change in the daily number of hot flushes with either tibolone or placebo (P= 0.219) after three months. There was a significant reduction in the severity of flushes with tibolone compared with placebo (-0.4 vs 0.2, P= 0.031). The Landgren scale showed a mean change in the number of hot flushes of -0.6 with tibolone and +1.1 with placebo after 12 months (P= 0.022). Endometrial biopsies were normal and vaginal bleeding was similar in both groups. A significant decrease in triglycerides (-23% vs 1.4%) and HDL (-12% vs 19%) was seen with tibolone compared with placebo after 12 months.

CONCLUSIONS

Tibolone prevented an increase in hot flushes in postmenopausal women given tamoxifen following surgery for breast cancer without untoward effects on the endometrium. Beneficial effects on serum lipid profile were noted.

The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study: design and baseline characteristics

The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) trial is a three-arm, randomized, placebo-controlled, double-blind study to determine the effect of tibolone 2.5 mg (Org OD 14) and continuous combined conjugated equine estrogens plus medroxyprogesterone acetate (0.625 mg/2.5 mg respectively) on progression of intima-media thickness of the carotid arteries and bone mineral density of the lumbar vertebrae and proximal femur in postmenopausal women. A total of 866 healthy postmenopausal women were recruited in six U.S. centers and five European centers. Duplicate carotid ultrasound examinations of the common carotid artery, the carotid bifurcation, and the internal carotid artery were performed at baseline. Single measurements of bone mineral density of the lumbar vertebrae and proximal femur were obtained at baseline. After randomization, ultrasound examinations were repeated every 6 months for 36 months following baseline, with a duplicate examination at the end of the study. Bone mineral density was measured every 12 months throughout the trial. The primary outcome is change in mean common carotid intima-media thickness (CIMT), defined as the average of the intima-media thickness measurements performed circumferentially at predefined angles for the near and far wall of 10-mm segments of the right and left distal common carotid arteries. Unique new features of the OPAL study are the specifically developed OPAL ultrasound protocol, yielding highly reproducible CIMT measurements, and the use of two experienced core laboratories for CIMT readings (one in the United States and one in Europe) with one common quality assurance and control program. The OPAL study is a large, placebo-controlled trial evaluating the effects of tibolone, as well as one of the first large randomized studies to determine the effects of continuous combined estrogen-progestin therapy on carotid atherosclerosis in healthy postmenopausal women. The OPAL study results are expected to complement other studies on atherosclerosis progression in healthy postmenopausal women.

Dose-response analysis of effects of tibolone on climacteric symptoms

OBJECTIVE

To assess the clinically optimal tibolone dose for the relief of climacteric complaints.

DESIGN

A randomised, double blind, placebo-controlled trial.

SETTING

Twenty-eight centres in Norway, The Netherlands, Sweden and Finland.

POPULATION

Seven hundred and seventy-five healthy postmenopausal women were randomised to tibolone in a daily dose of 0.625, 1.25, 2.5 or 5.0 mg or placebo for 12 weeks.

METHODS

At baseline, and after 4, 8 and 12 weeks, hot flushes, sweating, vaginal bleeding and adverse experiences were recorded.

MAIN OUTCOME MEASURES

Change in frequency and intensity of hot flushes and sweating over 12 weeks.

RESULTS

From week four onwards, 2.5 and 5.0 mg tibolone were significantly more effective than placebo, regarding the frequency of hot flushes and sweating (P < 0.001), whereas the 0.625 mg dose was not significantly different from placebo during the study. The frequency of hot flushes with the 1.25 mg dose was statistically significantly different from placebo, only from week eight onwards. The incidence of dropouts due to insufficient therapeutic effect was much higher in the tibolone 1.25 mg group (9.5%) than in the 2.5 (1.9%) and 5.0 mg (1.3%) groups. A dose-related increase in incidence of vaginal bleeding or spotting was observed (P < 0.0001). Bleeding incidence in the 5.0 mg dose group was about twice as high as in the 2.5 mg dose group. There was no difference in incidence of adverse experiences between the 2.5- and the 1.25 mg dose group.

CONCLUSION

A daily dose of 2.5 mg tibolone is the clinically optimal dose for the treatment of climacteric complaints in postmenopausal women.

Effect of tibolone compared with sequential hormone replacement therapy on carbohydrate metabolism in postmenopausal women

OBJECTIVE

To investigate the effects of tibolone on carbohydrate metabolism, and to compare these effects with those of a sequential regimen of conjugated equine estrogens and medrogestone.

METHODS

This was an open-label, multicentre, comparative study. Seventy-two postmenopausal women were randomized to receive either tibolone 2.5 mg/day or conjugated equine estrogens 0.6 mg plus sequential medrogestone 5 mg (CEE/M) for six 28-day cycles. Carbohydrate metabolism was evaluated at baseline and after three and six cycles of treatment by an oral glucose tolerance test (OGTT). A blood sample was taken at 30, 60, 90 and 120 mm after glucose 75 mg dosing for determination of plasma glucose, insulin and connecting peptide (C-peptide) levels.

RESULTS

The changes from baseline of glucose, insulin and C-peptide area-under-the-curve (AUC) values were not statistically significant after 3 and 6 months of tibolone or CEE/M treatment. There was a small transitory decrease in HbA(1C) after three cycles of treatment with tibolone.

CONCLUSION

The effects of tibolone and CEE/M on carbohydrate metabolism were considered to have no clinical significance.

Effects of tibolone on the endometrium

OBJECTIVE

To investigate the effects of 24 months of tibolone treatment on the endometrium in postmenopausal women.

DESIGN

An open, prospective, multicenter study with a treatment duration of 24 months.

POPULATION

One hundred and fifty healthy postmenopausal women.

METHODS

Women were treated with one tablet of tibolone (2.5 mg Org OD14) daily. Endometrial biopsies were taken at baseline, 12 months (n = 112) and 24 months (n = 62) to investigate endometrial histology by means of light microscopy.

RESULTS

No stimulation of atrophic endometrium was observed in 98.2% and 91.9% of the analyzed women after 12 and 24 months, respectively. A change from an atrophic endometrial pattern to a weakly proliferative pattern was seen in 1.8% (95% confidence interval (CI) 0.22-6.45) and 6.5% (95% CI 1.20-7.51) of the women after 12 and 24 months, respectively. In one woman, the endometrial pattern after 24 months was classified as simple hyperplasia (1.6%; 95% CI 0.01-3.20). The low incidence of proliferation and/or hyperplasia corresponds to that seen in other clinical trials in which women have been treated with placebo. Vaginal bleeding and/or spotting was reported by 18 women (12%), all showing an atrophic endometrium at all assessments, except for one woman with a proliferative endometrium at 24 months.

CONCLUSION

In the majority of women (92%), the endometrium remained atrophic during 24 months of tibolone treatment.

Effects of tibolone and continuous combined hormone replacement therapy on parameters in the clotting cascade: a multicenter, double-blind, randomized study

OBJECTIVE

To determine the effects of tibolone and continuous combined HRT (ccHRT) on parameters in the clotting cascade.

DESIGN

Randomized, double-blind study.

SETTING

Hemostasis unit of a university hospital clinic in Germany.

PATIENT(S)

Sixty healthy postmenopausal women.

INTERVENTION(S)

Twenty-nine subjects were treated with tibolone (2.5 mg/d) and 31 with oral ccHRT containing estradiol (2 mg/d) + estriol (1 mg/d) + norethindrone acetate (1 mg/d).

MAIN OUTCOME MEASURE(S)

Effects on parameters in the clotting cascade at baseline and after 12 and 24 weeks of treatment.

RESULT(S)

Tibolone increased fibrinolysis parameters without significantly altering coagulation parameters. Treatment with ccHRT resulted in a stimulating effect on parameters of both fibrinolysis and coagulation. Tibolone showed a stronger reduction of factor VII activity; less reduction of AT-III, protein C activity, and protein S activity; stronger increase of the activated partial thromboplastin time, plasminogen and plasminogen-antiplasminogen complexes; and less increase of D-Dimer than ccHRT. Both preparations similarly reduced climacteric complaints, whereas tibolone showed less breast complaints than ccHRT.

CONCLUSION(S)

This study confirms that tibolone, and to a lesser extent also ccHRT, changes hemostasis parameters toward a more fibrinolytic profile, which may diminish the risk of venous thrombosis.

Psychoendocrinological assessment of the menstrual cycle: the relationship between hormones, sexuality, and mood

The role of sex hormones in sexuality and mood across the menstrual cycle was investigated. Twenty-one normal health women were followed for one menstrual cycle. Blood samples were taken frequently, and analyzed for estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone sulfate, cortisol, and sex hormone-binding globulin. A diary concerning sexual interest and behavior, and different moods, was completed daily. Although the sample was not large, a clear effect of menstrual cycle phase on levels of testosterone and the free testosterone index was demonstrated. In a preliminary screening interview, 11 of the 21 women had reported that they suffered from premenstrual complaints (PC), the other 10 had reported no complaints in the premenstrual phase (NPC). Significant differences between the two groups were established in estradiol and the estradiol-progesterone ratio, with the NPC group having higher levels of both endocrine parameters across different menstrual samples. Psychologically, a cycle effect on tension and sexual interest was demonstrated. The NPC group reported a peak in sexual interest in the premenstrual phase, whereas the PC group reported a peak in the ovulatory phase. There was a difference between the two groups in feelings of fatigue but not in other moods across the menstrual cycle. The study provides further evidence of the importance of androgen levels in women's sexuality and shows again that the relationship between menstrual cycle phase and sexuality is much clearer than between phase and mood.

Oestrus, ovulation and peri-ovulatory hormone profiles in tethered and loose-housed sows

Multiparous sows that had been tethered during lactation were put in two different housing conditions after weaning (Day 0); the sows were either tethered by neck chain, or individually housed in a pen of approximately 6 m2. After two months, ten tethered and eleven loose housed sows were used to assess stress and reproductive parameters. Stereotypic behaviour after the afternoon feeding was assessed from Day 18 onwards; at Day 53 stereotypic behaviour tended to occur during a higher percentage of time in the tethered sows (P = 0.11) and at Day 66, the differences were significant (tethered, 78 +/- 5 vs. loose-housed, 40 +/- 10% of time (mean +/- sem); P = 0.03). At Day 35 and 55, cortisol profiles after afternoon feeding were similar for the two groups of sows (P > 0.10). Around oestrus (approximately Day 64), the profiles of oestradiol-17 beta, luteinizing hormone and progesterone were measured and proved to be similar for both treatment groups (P > 0.10). The duration of oestrus was shorter in the tethered sows (42 +/- 4 vs. 63 +/- 2 h; P < 0.001) and, consequently, the timing of ovulation during oestrus (h after onset of oestrus) was advanced in the tethered sows (28 +/- 2 vs. 41 +/- 2; P < 0.001). The duration of ovulation did not differ (tethered, 2.9 +/- 0.5 vs. loose-housed, 2.1 +/- 0.2 h; P = 0.16). The sows were sacrificed at Day 5 after ovulation; ovulation rate, fertilization rate, embryo development and embryo diversity were similar for the two groups, as were adrenal weight and size of adrenal cortex. Duration of oestrus and the levels of stereotypies at Day 60 tended to be negatively related in the tethered sows (P = 0.07), but not in the loose-housed sows (P = 0.65). In conclusion, sows that had been tethered during pregnancy and lactation, and were housed loose or were tethered again at weaning within two months differed both in stereotypic behaviour and in duration of oestrus, without apparent effects on reproductive hormones.

Rearing piglets in a poor environment: developmental aspects of social stress in pigs

Effects of rearing conditions on the development of social relationships were investigated in female pigs. For that purpose, one group of piglets was reared in a poor environment (i.e., a commercially used indoor 4.2-m2 standard farrowing crate) and the other in an enriched environment (i.e., 0.5-ha outdoor pasture with half-open farrowing crates). After weaning, all piglets were housed in pairs under standard conditions. Dominant and subordinate individuals were distinguished within pairs and social relationships between members of a pair were studied in adulthood. The results show that pairs reared in a poor environment behave more aggressively. The subordinates of these pairs also develop symptoms indicative of chronic social stress exposure: i.e., they show a delayed onset of puberty, a smaller daily weight gain, and elevated basal cortisol levels that are also higher 5 h after an acute restraint stressor (tethering stress). No such deviations were found in subordinates reared in an enriched environment. It is concluded that rearing piglets in a poor environment may facilitate the development of social stress in adult (subordinate) pigs. Two underlying mechanisms may be proposed: a) deteriorated social skills lead to increased social stress, or b) a failure to cope with stressors in general, and the stress of being subordinate in particular, occurs in animals reared under poor conditions.

Glucose tolerance of pregnant sows is related to postnatal pig mortality

An experiment was conducted on three farms to study the relationship between the results of an oral glucose tolerance test on d 104 +/- 4 of pregnancy and subsequent reproductive performance of 104 multiparous sows. After an overnight period without feed, sows were fed (3 g/kg BW.75) glucose, and blood samples were taken for analyses of glucose at -10, 10, 20, 30, 40, 50, 60 70, 80, 90, 105, and 120 min after administration of glucose. Glucose concentrations before glucose administration ranged from 2.0 to 3.6 mmol/L. Sows with lesser pretest glucose concentrations had longer (P < .01) durations of pregnancy (corrected for number of live pigs born) and heavier (P < .05) pigs at birth (corrected for farm and number of live pigs born). Peak glucose concentrations and areas under the curves (i.e., first 70 min and entire 120 min) ranged from .1 to 4.4 mmol/L, -40 to 211 (mmol/L).min, and -95 to 247 (mmol/L).min, respectively. Sows with greater (P < .01) peak concentration of glucose and greater area under the curve (first 70 min [P < .01] and entire 120 min [P < .01]) had increased pig mortality during the first 7 d after farrowing (corrected for live weight of the sows). In 83 sows, a sample of morning urine (before feeding) was collected and tested for glucose and ketone bodies. Neither glucose nor the ketone body acetoacetic acid was detected in the urine. The results indicate that sows that are less glucose-tolerant have greater pig mortality.

Effects of energy source in the diet on reproductive hormones and insulin during lactation and subsequent estrus in multiparous sows

Two experiments were performed. The first experiment was done to study the effects of dietary energy source on plasma insulin concentration using five gilts in a Latin square design with two diets over two periods. The diets contained either 200 g/kg of cornstarch (Starch) or soybean oil (Fat) as energy sources. Results indicate that insulin response was greater in the Starch-fed than in the Fat-fed gilts. A second experiment was performed in which 18 multiparous sows were fed one of the two experimental diets from farrowing until slaughter at d 35 of subsequent pregnancy. All sows nursed nine pigs. Blood samples were taken from a permanent jugular vein catheter every 12 min during a 12-h period on d 109 +/- 1 of pregnancy, on d 7 +/- 1, 14 +/- 1, and 21 +/- 1 of lactation, and on the day of weaning ( d 22 +/- 1). From 48 h after weaning, blood samples were taken every 4 h until 24 h after ovulation. After that, blood samples were taken at 12-h intervals until d 10 after ovulation. Differences between diets in insulin response were not significant. In Starch-fed sows, LH pulsatility at d 7 of lactation was greater (P < .05), the preovulatory LH surge was greater ( P < .05), and progesterone production was greater (P < .05) from 108 h until 256 h after the LH surge than in the Fat-fed sows. Results indicate that feeding Starch-rich diets to multiparous sows compared with Fat-rich diets, on an isocaloric basis, increases LH pulsatility during early lactation, the preovulatory LH surge, and progesterone production after the LH surge.

The effect of chronic stress on plasma cortisol concentrations in cyclic female pigs depends on the time of day

The influence of tethered housing (a condition of chronic stress) on morning and evening basal plasma cortisol levels was investigated in a longitudinal study in cyclic female nulliparous pigs (gilts). After a period of loose housing in individual pens ("nonstress" estrous cycles), six cannulated gilts were tethered by a neck chain and housed for a period of 20 wk (chronic stress estrous cycles). Blood was sampled twice daily (1000 and 1800 hr) for cortisol determination. Plasma cortisol levels showed a diurnal rhythm with significantly higher levels at 1000 hr than at 1800 hr. Tethered housing induced a significant increase in the 1800-hr plasma cortisol concentrations during the first three estrous cycles after tethering, whereas the 1000-hr plasma cortisol concentrations did not change throughout the experimental period. During the period of increased 1800-hr levels, cortisol was still released in a circadian fashion, albeit, the rhythm was flattened. In control gilts, housed loose during the entire experimental period, plasma cortisol concentrations at 1000 hr and at 1800 hr remained unaltered and 1000-hr cortisol concentrations were significantly higher than the 1800-hr concentrations during the experimental period. Therefore, possible effects of the experimental procedure or age-related effects could be excluded. These data indicate that, in tethered gilts, the chronic stress-induced hypercortisolemia is of transient nature, suggesting adaptive changes in the regulation of the hypothalamic-pituitary-adrenocortical axis. In addition, the data reveal circadian differences in the effect of chronic stress on hypothalamic-pituitary- adrenocortical function.

Chronic stress and pituitary-adrenocortical responses to corticotropin-releasing hormone and vasopressin in female pigs

Effects of long-term tethered housing (a condition of chronic stress) on pituitary-adrenocortical responsiveness to exogenous corticotropin-releasing hormone (CRH) and lysine8-vasopressin (LVP) were investigated in female pigs. Intravenous administration of CRH (dose range 10-440 pmol/kg body wt) or LVP (10-880 pmol/kg body wt) elicited transient and dose-related increases in plasma concentrations of adrenocorticotropic hormone (ACTH) and cortisol. Comparison of the responses induced by the peptides indicated that CRH is a more potent ACTH secretagogue than LVP. Treatment with LVP produced a fivefold greater plasma cortisol/ACTH ratio than treatment with CRH, suggesting that in addition to stimulating pituitary ACTH release it enhanced the ability of the adrenal cortex to secrete cortisol in response to ACTH. Whereas concomitant administration of 10 pmol CRH/kg body wt and 20 pmol LVP/kg body wt revealed an additive effect on ACTH release, synergism between both peptides was found with respect to their cortisol-releasing effect. Ten to thirteen weeks of chronic stress did not alter significantly the absolute ACTH and cortisol responses to the two peptides. In tethered pigs, the cortisol/ACTH ratio after CRH treatment, calculated from the area under the curve, was twofold that in loose-housed pigs. From these observations we conclude that after chronic stress the sensitivity of the adrenocortex to circulating ACTH was increased, whereas the sensitivity of the pituitary to CRH and/or LVP remained unaltered.

Chronic stress increases the opioid-mediated inhibition of the pituitary-adrenocortical response to acute stress in pigs

The role of endogenous opioid mechanisms in the pituitary-adrenocortical response to acute stress was investigated in a longitudinal study in cyclic female pigs before and after exposure to chronic stress (long term tethered housing). Challenge of loose-housed pigs with acute nose-sling stress for 15 min induced an activation of the hypothalamic-pituitary-adrenocortical axis, evidenced by a transient increase in plasma ACTH (peak height above basal, 98 +/- 12 pg/ml; mean +/- SEM) and cortisol (54 +/- 3 ng/ml) concentrations. Pretreatment with the opioid receptor antagonist naloxone (0.5 mg/kg BW, iv bolus) increased the challenge-induced ACTH and cortisol responses to 244 +/- 36 pg/ml and 65 +/- 5 ng/ml, respectively. This indicates that during acute nose-sling stress, endogenous opioid systems are activated that inhibit the pituitary-adrenocortical response. After exposure of the pigs to chronic stress (10-11 weeks of tethered housing), the challenge-induced ACTH response was attenuated, whereas the cortisol response remained unchanged, suggesting an increased adrenocortical sensitivity to circulating ACTH. In addition, pretreatment with naloxone induced a greater increment in the ACTH and cortisol responses in tethered pigs than in loose-housed pigs. As no such changes were found in control animals housed loose during the entire experimental period, this indicates that the impact of opioid systems had increased due to chronic stress. The increased impact of opioid systems during chronic stress may prevent excessive hypothalamic-pituitary-adrenocortical responses to acute stressors and, thus, may be of adaptive value.

Periovulatory profiles of oestradiol, LH and progesterone in relation to oestrus and embryo mortality in multiparous sows using transrectal ultrasonography to detect ovulation

The timing of oestrus, the concentrations of oestradiol, LH and progesterone, and embryo survival on day 35 of pregnancy in 16 weaned multiparous sows were studied in relation to the moment of ovulation. Ovulation was detected using transrectal ultrasonography. The interval between weaning and ovulation varied between 126 and 214 h (156 +/- 29). The peak oestradiol concentration was 27 +/- 17 pg ml-7; sows with a shorter interval between weaning and ovulation had higher peaks of oestradiol (r = -0.54, P = 0.02). The interval between the peak oestradiol concentration and peak LH concentration was 11 +/- 4 h. The shape, width and height of the LH surge were variable, but did not influence the interval between the peak LH concentration and ovulation, which varied between 26 and 34 h (30 +/- 3). The interval between ovulation and the time when the progesterone concentration rose to more than 1.0 ng ml-1 above basal progesterone concentrations varied from 6 to 19 h (13 +/- 4). Ovulation took place at a more or less constant relative time of the oestrous period (after 72 +/- 8% of the duration of oestrus), irrespective of the duration of oestrus. The timing of the peak concentrations of oestradiol and LH and the rise in progesterone concentrations were closely related to the occurrence of ovulation but not to the onset of oestrus. Embryo survival on day 35 of pregnancy was related to the interval between the peak concentrations of oestradiol and LH (r = -0.68, P = 0.02); shorter intervals resulted in higher embryo survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased cortisol response to exogenous adrenocorticotropic hormone in chronically stressed pigs: influence of housing conditions

In a longitudinal experiment, the influence of tethered housing (a condition of chronic stress) on the reactivity of the adrenal cortex to exogenous ACTH was investigated in gilts. To that end, the plasma cortisol response to synthetic ACTH (1-24; 10 micrograms/kg of BW; i.v. bolus injection via a permanent catheter) was determined before and after prolonged tethered housing. Two systems for tethered housing were used, one more restrictive than the other with regard to possibilities for visual and tactile contacts with conspecifics and visual control over the environment. The ACTH treatment induced a marked, transient plasma cortisol response in all gilts studied, irrespective of their housing conditions. Long-term tethered housing increased the ACTH-induced cortisol response. Possible effects of the experimental procedure or age-related effects could be excluded, because in control gilts, which were housed loose during the entire experimental period, the cortisol response to ACTH remained unaltered. The chronic stress-induced increase in the ACTH-induced cortisol response was considerably more pronounced and persistent in gilts that were deprived of possibilities for social contacts with conspecifics and visual control over the environment than in gilts with such possibilities. These data indicate that in tethered gilts adaptational changes occur at the level of the adrenal cortex that affect the ACTH-induced adrenocortical response. In addition, not only physical restraint but also restriction of social contact and visual control play an important role in the development of these changes.

Effect of flushing of blastocysts on days 10-13 on the life-span of the corpora lutea in the pig

Blastocysts were flushed out of both uterine horns of gilts on Days 10, 11, 12 or 13. In mated non-pregnant gilts flushing had no effect on progesterone profile or cycle length (20.8 +/- 0.4 versus 20.6 +/- 0.6 days in the preflush cycle, N = 6, mean +/- s.e.m.). Flushing the blastocysts out of the uterine horns on Day 10 resulted in a cycle with a normal progesterone profile and a normal length (21.2 +/- 0.4 days, N = 5). Flushing on Days 11, 12 or 13 resulted in a normal cycle or in maintenance of the CL for 3-13 days as indicated by elevated progesterone concentrations and an increased interoestrous interval of, respectively, 22.0 +/- 1.2 versus 19.8 +/- 0.6 days (Day 11; N = 6), 24.8 +/- 1.4 versus 21.0 +/- 0.6 days (Day 12; N = 5; P less than 0.05) and 26.3 +/- 2.3 versus 20.5 +/- 0.4 days (Day 13; N = 6; P less than 0.05). There was a positive relationship between the change in interoestrous interval and the interval between the first observed standing oestrus and flushing of the blastocysts (rs = 0.350; n = 22; P less than 0.1). There was a large variation in the diameter of the blastocysts flushed on the same day. Only in those gilts in which the blastocysts were greater than or equal to 8 mm or filamentous were the CL maintained for 3 or more days. These results indicate that a first signal for maternal recognition of pregnancy is generated on Day 12 and that blastocysts greater than or equal to 8 mm are required for prolongation of CL function for 3 or more days. Since CL function is only extended for a maximum of 13 days (mean 7.4 +/- 1.0), a second signal seems necessary to maintain the CL for the whole period of pregnancy.

Endometriosis in rhesus monkeys

9 Cases of endometriosis in rhesus monkeys were found in a colony of 35 females, which had undergone in the past X-ray treatment or one or more Caesarean sections and/or one or more treatments with gonadal steroids. Incidence, pathogenesis, clinical symptoms, histology and treatment are described.

Strength and duration characteristics of the facilitory and inhibitory effects of progesterone on the estrogen-induced gonadotropin surge in the female rhesus monkey

The dose-dependent effects of progesterone (P) on estradiol (E2)-induced gonadotropin release were investigated in the early follicular phase of female rhesus monkeys by sc implanting Silastic capsules containing either crystalline E2 or P. In group 1, E2 alone (250 pg/ml) and E2 in combination with P (1.5, 3, and 5 ng/ml) were administered in four consecutive experiments. The lowest P dosage (1.5 ng/ml) advanced the time of the maximal gonadotropin release, but the magnitude seemed to be decreased compared to that in the experiment with E2 alone. The higher P dosages (3 and 5 ng/ml) blocked the previously observed E2-induced gonadotropin surges. In group 2, E2 alone (250 pg/ml) and E2 in combination with P (1.5, 5, and 20 ng/ml), added 46 h after E2, were administered in four consecutive experiments. In all experiments, P advanced and increased the gonadotropin peaks. The FSH surges could be increased even further in the experiments with the two highest P dosages (5 and 20 ng/ml). After this period of facilitated gonadotropin secretion, we observed lower gonadotropin levels than those in the control experiment with E2 alone. This effect became more apparent by increasing by P dosage. These results point to a biphasic effect of P across time and dosage on the release of gonadotropins.