An EBMT registry matched study of allogeneic stem cell transplants for lymphoma: allogeneic transplantation is associated with a lower relapse rate but a higher procedure-related mortality rate than autologous transplantation.

The role of allogeneic bone marrow transplantation in lymphoma remains uncertain. We have analyzed 1185 allogeneic transplants for lymphoma reported to the EBMT registry between 1982 and 1998 and compared the results with those of 14687 autologous procedures performed over the same period. Patients receiving allogeneic transplants were subdivided according to histology: low-grade non-Hodgkin's lymphoma (NHL) 231 patients; intermediate-grade NHL 147 patients; high-grade NHL 255 patients; lymphoblastic NHL 314 patients; Burkitt's lymphoma 71 patients; and Hodgkin's disease 167 patients. These patients received allogeneic transplants as their first transplant procedure. Actuarial overall survival (OS) at 4 years from transplantation was: low-grade NHL 51.1%; intermediate-grade NHL 38.3%; high-grade NHL 41.2%; lymphoblastic lymphoma 42.0% years; Burkitt's lymphoma 37.1%; and Hodgkin's disease 24.7% years. These outcomes are relatively poor because of the high procedure-related mortality associated with these procedures, particularly in patients with Hodgkin's disease (51.7% actuarial procedure-related mortality at 4 years). Multivariate analysis showed that for all lymphomas apart from Hodgkin's disease, status at transplantation significantly affected outcome. A matched analysis was performed: for all categories of lymphoma, OS was better for autologous than for allogeneic transplantation. Relapse rate was better in the allogeneic group for low-, intermediate- and high-grade, and lymphoblastic NHL. It was equivalent for Burkitt's lymphoma and worse in the allogeneic group for Hodgkin's disease. Allogeneic transplantation appears to be superior to autologous procedures in terms of producing a lower relapse rate. The toxicity of allogeneic procedures must however be reduced before this translates into an improvement in OS.

In vivo CAMPATH-1H prevents GvHD following nonmyeloablative stem-cell transplantation.

BACKGROUND: We have investigated a novel nonmyeloablative conditioning regimen in 44 patients with hematological malignancies. The median patient age was 41 years. Many of the patients had high-risk features, including 19 patients with a previous failed transplant. METHODS: Recipient conditioning consisted of CAMPATH-1H 20 mg/day on Days -8 to -4, fludarabine 30 mg/m(2) on Days -7 to -3 and melphalan 140 mg/m(2) on Day -2. Thirty-six recipients received unmanipulated G-CSF mobilized PBSC from HLA identical siblings and eight received unmanipulated BM from MUD. GvHD prophylaxis was with CYA alone for 38 patients and CYA plus MTX for six sibling recipients. RESULTS: Forty-two of the 43 evaluable patients had sustained engraftment. Results of chimerism analysis using microsatellite PCR indicate that 18 of 31 patients studied were full donor chimeras, while the other patients were mixed chimeras in one or more lineages. At a median follow-up of 9 months (range, 3-29 months) 33 patients remain alive in CR, or with no evidence of disease progression. Seven patients relapsed or progressed post-transplant and four of them subsequently died. Four patients died from regimen-related complications. There were no cases of Grades III-IV acute GvHD. Only two patients developed Grade II acute GvHD and only one had chronic GvHD. The estimated probability of non-relapse mortality at 1 year was 11%.Results: Although longer follow-up is needed to establish the long-term remission rates, this study demonstrates that this nonmyeloablative preparative regimen is associated with durable engraftment, minimal toxicity and low incidence of GvHD.

Secondary leukaemia and myelodysplasia after autografting for lymphoma: results from the EBMT. EBMT Lymphoma and Late Effects Working Parties. European Group for Blood and Marrow Transplantation.

Between 1978 and 1996 more than 7500 lymphoma transplants have been reported to the European Bone Marrow Transplantation (EBMT) Lymphoma Registry. This has been examined to establish the incidence of secondary leukaemia and myelodysplasia and to relate this to possible prognostic factors. 131 centres representing 4998 patients responded to a questionnaire. This identified 66 patients with post transplant myelodysplastic syndrome (MDS)/acute myeloid leukaemia (AML). The actuarial risk for MDS/AML at 5 years post-transplant (+/-95% CI) was 4.6% (3.1-6.8) for Hodgkin's disease and 3.0% (2.0-4. 3) for non-Hodgkin's lymphoma. Multivariate analysis for all patients demonstrated an effect of age at transplant, radiotherapy at conditioning, number of transplants and interval between diagnosis and transplant as risk factors. For patients with NHL, grade of histology was important (low grade > intermediate or high-grade); for Hodgkin's disease, female sex was identified as a risk factor. These findings suggest that the incidence of MDS/AML may not be greater following an autograft than after conventional chemotherapy.

Outcome of epithelial ovarian cancer in women under 40 years of age treated with platinum-based chemotherapy.

We retrospectively investigated the outcome of ovarian cancer in women aged less than 40 years treated in three randomised phase III studies of platinum-based chemotherapy. 624 patients had invasive epithelial ovarian cancer. A Cox proportional hazard model was used to study prognostic variables. 29 women (5%) were under 40 years of age. Stage, histological grade and amount of residual disease were significantly worse in women aged > or = 40 years. Median follow-up was 66.7 months. At 5 years 65% of women below 40 years of age were alive compared with 20% of older women (95% confidence interval (CI) of the difference 27.1-63.0). The progression-free interval was 59% versus 16% (95% CI 24.3-60.8). No patient under 40 years of age relapsed after 18 months. Age > or = 40 years was a poor prognostic variable, particularly for serous tumours, the commonest subtype in younger women (hazard ratio (HR): 3.33). Other prognostic factors were Eastern Cooperative Oncology Group (ECOG) performance status (HR: 1.25), presence of residual disease (HR: 1.43), histological grade (HR: 1.36) and International Federation of Gynaecology and Obstetrics (FIGO) stage (HR: 1.47). These results suggest that there are biological differences in the behaviour of serous carcinoma of the ovary in women of reproductive age compared with older women.

Autologous stem cell transplantation for T and null cell CD30-positive anaplastic large cell lymphoma: analysis of 64 adult and paediatric cases reported to the European Group for Blood and Marrow Transplantation (EBMT).

Anaplastic large cell lymphoma (ALCL) is a heterogeneous family of lymphoid tumours, among which the T and null cell types were recently listed in the REAL classification as a distinct entity. Reports on autologous stem cell transplantation (ASCT) in this group are only occasional. Sixty-four patients with T and null cell ALCL from 25 European centres had been registered with the European Group for Blood and Marrow Transplantation (EBMT) at the onset of this study. The median age was 25 years (range 3.2-53.0). Thirty of the 64 patients (47%) were in complete remission (CR), 18 (28%) in partial remission (PR), and the remaining 16 (25%) had a more advanced or chemotherapy-refractory disease at transplant. Eighty-one percent of the patients were conditioned with chemotherapy alone and 75% received marrow stem cells. All the patients transplanted in first CR (15), except one, maintained the CR over time; six of 15 transplanted in CR subsequent to first, six of 18 transplanted in PR and 14 of 16 transplanted in refractory or relapsed disease progressed. Actuarial overall survival (OS) at 10 years is 70%. Multivariate analysis showed that good status at transplant, younger age, absence of B symptoms and absence of extranodal disease indicated a better prognosis. These data suggest that ASCT should be considered as a possible treatment for chemosensitive patients in CR or PR. However, definitive conclusions cannot be drawn from this study and a prospective randomised trial between ASCT and conventional chemotherapy may be indicated.

Five-day oral etoposide treatment for advanced small-cell lung cancer: randomized comparison with intravenous chemotherapy.

BACKGROUND: Oral etoposide is an active single agent in small-cell lung cancer (SCLC) and is widely prescribed as first-line treatment as an alternative to intravenous combination chemotherapy in patients with extensive disease. PURPOSE: The intention of this study was to determine if the effects of oral etoposide therapy on survival and quality of life are equivalent to those of intravenous chemotherapy. METHODS: In a randomized trial of palliative treatment in advanced SCLC, oral etoposide (100 mg given twice daily for 5 days) was compared with intravenous chemotherapy consisting of alternating cycles of cisplatin and etoposide (PE) and cyclophosphamide, doxorubicin, and vincristine (CAV). Six cycles of chemotherapy were administered every 21 days in both regimens. Symptom control and quality of life were measured with the Rotterdam Symptom Checklist and a daily diary card. In January 1996, after 155 patients had been randomly assigned from a projected intake of 365 patients, an independent Data Monitoring Committee examined the interim results. Survival was determined by the Kaplan-Meier method, and the logrank test was used to compare treatments. For quality-of-life comparisons, average scores were calculated for each time point. The Mann-Whitney U test was used to determine any significant overall differences between treatments. For the Rotterdam Symptom Checklist, separate analyses were done for each subset (psychological well-being, physical symptoms, lung cancer symptoms, treatment symptoms, activity, and quality of life). Response rates and toxicity scores were compared by using chi2. All statistical tests were two-sided. RESULTS: Survival was inferior at 1 year in the oral etoposide group compared with intravenous therapy (9.8% for oral versus 19.3% for intravenous; difference = 9.5%; 95% confidence interval of difference = 0.3%-18.7%; P<.05), and there was a trend toward inferior overall survival. Median survival was 4.8 months for oral treatment and 5.9 months for intravenous therapy. Progression-free survival was worse in the oral etoposide arm (median = 3.6 months versus 5.6 months; P<.001), as well as overall response rate (32.9% versus 46.3%; P<.01). With the exception of acute nausea and vomiting associated with intravenous chemotherapy, all aspects of symptom control and quality of life were either the same or worse in the oral etoposide group. Study closure was recommended. CONCLUSIONS: These interim results show that this schedule of oral etoposide is inferior to intravenous chemotherapy in the treatment of advanced SCLC and should not be used as first-line treatment of this disease.

A randomised trial of low-dose/high-frequency chemotherapy as palliative treatment of poor-prognosis small-cell lung cancer: a Cancer research Campaign trial.

We report the results of a randomised trial in extensive small-cell lung cancer (SCLC) of a novel approach to palliative chemotherapy. A widely used 3 weekly regimen was compared with the same drugs given at half the dose but twice the frequency with the same intended overall dose intensity (DI). A total of 167 patients defined as having extensive SCLC with adverse prognostic features were randomised to receive either a 3 weekly regimen of cisplatin 60 mg m-2 i.v. on day 1 and etoposide 120 mg m-2 i.v. on day 1 and 100 mg b.d. orally on days 2 and 3 alternating with cyclophosphamide 600 mg m-2 i.v., doxorubicin 50 mg m-2 i.v. and vincristine 2 mg i.v. all on day 1 for a maximum of six courses (3 weekly); or treatment with the same drugs but with each course consisting of half the 3 weekly dose given every 10 or 11 days for a maximum of 12 courses. In the 10/11 day regimen overall response rate was 58.9% (95% CI, 47.9-69.2%) with 12.8% complete responses (CR). For the 3 weekly treatment the overall response rate was 44.9% (95% CI, 35.0-55.5%) with 10.1% CR. Median survival was similar in the two arms at 6.4 months (95% CI, 4.9-7.3 months) and 5.8 months (95% CI, 4.0-6.6 months) respectively. Survival at 1 year was 9.9% (95% CI, 5.0-18.5%) and 8.9% (95% CI, 4.6-16.6%). The 95% CI for the difference in survival at 1 year is -7.09% to +9.09%. Haematological toxicity and treatment delays owing to infection were more frequent with the 10/11 day regimen but other toxicities were equal in both arms. Other aspects of quality of life were measured in a small representative cohort of patients using a daily diary card (DDC). There was a trend of improved quality of life on the 10/11 day arm, but there was little difference between the two treatments. The trial shows that a low-dose/high-frequency regimen with the same DI as conventionally scheduled chemotherapy gives similar response rates and survival. This and other modifications of the schedule may offer new approaches to palliative treatment of advanced cancer. However, in this trial there was no significant benefit in toxicity or other aspects of quality of life.

Assessment of 'quality of life' using a daily diary card in a randomised trial of chemotherapy in small-cell lung cancer.

BACKGROUND: Quality of life (QOL) was assessed using a daily diary-card within a multicentre randomised trial of treatment of small-cell lung cancer. The trial compared a weekly dose-intensive regimen with a 3-weekly conventional treatment in good prognosis patients, that is patients with limited disease or extensive disease with a good performance status (ECOG 0or 1) and alkaline phosphatase of less than one and a half times the upper limit of normal. The trial which has been previously reported detected no difference in response or survival. PATIENTS AND METHODS: Daily diary cards (DDCs) were collected for up to eight months from the first day of chemotherapy in a cohort of 75 patients at one centre. Percentages of scores over a specified level were calculated for each of the eight diary card questions and comparisons were made between treatment arms. RESULTS: During the period of chemotherapy compliance in completing DDCs was 72.5% in the weekly arm and 77.2% in the 3 weekly. Significantly worse scores were reported with weekly chemotherapy during this period for six of the eight parameters, namely: ;nausea, vomiting, happiness, appetite, general well-being and sleep. Recognised problems of QOL data collection, in particular, compliance, attrition and generalisability are highlighted by this study and are discussed in the paper. CONCLUSIONS: The QOL measurements indicate that 3 weekly chemotherapy is the preferred treatment. This study demonstrates that QOL measurements may be helpful in choosing between treatment alternatives where no difference in outcome is observed.

Randomized trial comparing weekly versus 3-week chemotherapy in small-cell lung cancer: a Cancer Research Campaign trial.

PURPOSE: A randomized trial of chemotherapy, given on either a 1-week or a 3-week schedule, was performed in small-cell lung cancer (SCLC) patients. The aim was to determine if weekly scheduling produced survival superior to conventional treatment. PATIENTS AND METHODS: Four hundred thirty-eight patients with SCLC with either limited disease (LD; 276 patients) or good-prognosis extensive disease (ED; 162 patients) were randomized. Weekly chemotherapy was 12 alternating cycles of ifosfamide/doxorubicin and cis-platin/etoposide (PE), while 3-week treatment was six alternating cycles of cyclophosphamide/doxorubicin/vincristine (CAV) and PE. Thoracic irradiation was administered 3 weeks after completion of chemotherapy to LD patients who attained a complete response (CR) or partial response (PR). Patients were well matched for clinical characteristics and prognostic factors. RESULTS: Overall response was the same in both arms: 82.3% (39.4% CR) with weekly and 81.1% (36.9% CR) with 3-week treatment. The median survival (MS) durations were 10.8 and 10.6 months for weekly and 3-week chemotherapy, respectively. The 2-year survival rates were 11.8% and 11.7% in the weekly and 3-week arms, respectively. Received dose-intensity (DI) was 73.9% of projected for weekly treatment and 92.7% for 3-week treatment. Hematologic toxicity was the major dose-limiting toxicity for the weekly treatment. CONCLUSION: This trial excludes at 90% power a benefit of greater than 10% for 2-year survival for weekly treatment. The received DI was reduced to a greater extent with weekly treatment, mainly due to hematologic toxicity.

Use of running wheels regulates the effects of the ovaries on circadian rhythms.

Free-running circadian rhythms in core temperature, wheel-running and general locomotor activity were studied in ovariectomized or intact female rats housed with or without access to a running wheel. No differences in the monitored parameters were found between the intact and ovariectomized rats without a wheel. In the presence of a wheel, however, the intact rats differed from those that had been ovariectomized by displaying a shorter circadian period, an increased amplitude of the temperature rhythm, and strikingly higher rates of wheel-running and general locomotor activity. After estradiol treatment, the ovariectomized rats with a wheel developed a small increase in the temperature amplitude, and also in the correlation between wheel-running and general locomotor activity; these changes were not associated with a significant increase in wheel-running or a shortening of the circadian period. We conclude that some of the differences in circadian function between intact and ovariectomized rats are due to the differential use they make of running wheels, when available, and not directly attributable to the absence or presence of gonadal steroids.

Maternal hypothyroxinemia and brain development: II. Biochemical, metabolic and behavioural correlates.

Using a rat model, we have investigated the influence of maternal hypothyroxinemia throughout pregnancy on brain development in young and adult progeny. Although no consistent change was observed in whole brain total protein concentration, the subcellular distribution of protein was adversely affected. Isolation of glycoprotein from developing brain by concanavalin A-affinity chromatography and subsequent resolution by gel electrophoresis revealed the selective compromise of particular glycoprotein species. Furthermore, both control and experimental progeny expressed unique glycoprotein species which either persisted over the period studied or were transient. Calcineurin, a regulator of neurite elongation, was compromised in young progeny, as were a number of lysosomal enzymes (beta-D-glucosidase and aryl sulphatase). In adult progeny, the content of cerebroside sulphate (a major myelin galactolipid) was reduced in midbrain and paleocortex, and brain region-specific compromise was observed for acetylcholine metabolic enzymes. These changes were associated with alterations in behavioural output. We conclude that the availability of maternal thyroxine to the fetus may be a critical determinant for normal brain development and function.

Catecholamine synthesis inhibitors increase pineal adrenaline content by stimulating adrenal medullary activity.

Estimation of noradrenaline and adrenaline utilization in the pineal gland of female rats was attempted using inhibitors of the enzymes that catalyse the catecholamine biosynthetic pathway. Treatment with FLA63, an inhibitor of dopamine beta-hydroxylase (10 mg/kg, 2 h before killing), induced depletion of noradrenaline and adrenaline in the preoptic area and median eminence (sites, respectively, inside and outside the blood-brain barrier) but, paradoxically, resulted in a significant increase (+77%) in the pineal content of adrenaline without affecting that of noradrenaline. Treatment with LY134046, an inhibitor of phenylethanolamine N-methyltransferase (40 mg/kg, 5 and 2 h before killing), induced depletion of adrenaline in the preoptic area and median eminence but, again, resulted in a paradoxical and large increase in pineal adrenaline (+224%); this increase was prevented by prior adrenalectomy. Blood samples taken from free-moving rats fitted with intravenous and intraperitoneal cannulae revealed a marked increase in plasma levels of adrenaline after each injection of LY134046. These results suggest that the adrenal medulla is the primary source for the increase in pineal adrenaline seen after administration of the enzyme inhibitors. The precise site of uptake and the biological implications of this phenomenon remain to be elucidated. Nevertheless, interpretation of in vivo experiments involving these catecholamine synthesis inhibitors should take this adrenal response into account.

Centrally administered neuropeptide Y enhances the hypothermia induced by peripheral administration of adrenoceptor antagonists.

The distribution of neuropeptide Y in the brain includes extensive coexistence within adrenaline- and noradrenaline-containing neurons and many of its actions are often associated with adrenergic systems. Since neuropeptide Y immunoreactivity is particularly intense in the preoptic area, one of the principal sites for thermoregulation, we have tested the effects of neuropeptide Y on core temperature in normothermic rats, and rats rendered hypothermic by systemic treatment with adrenergic antagonists. In the normothermic rat, intracerebroventricular administration of 1 microgram of neuropeptide Y did not have a significant effect on core temperature. Intraperitoneal treatment with the alpha 1-adrenoceptor antagonist, prazosin, or the beta-adrenoceptor antagonist, propranolol, caused an immediate and significant hypothermia; the intracerebroventricular administration of 1 microgram of neuropeptide Y, 10 minutes after these drugs, strongly potentiated their hypothermic effect. Although intraperitoneal treatment with the alpha 2-adrenoceptor antagonist, idazoxan, had no hypothermic effect per se, the intracerebroventricular administration of NPY 10 minutes after this antagonist led to a significant decrease in core temperature.

Maturation of thyroid function in normal human foetuses.

The functional maturation of an independent foetal thyroid activity was investigated in the present study. Serum concentrations of total T4, free T4, TSH and TBG were measured in 23 foetuses between 18 and 31 weeks' gestational age. Foetal samples were collected by transabdominal needling from the placental cord insertion. TT4, FT4, TBG and TSH levels significantly increased with gestational age. FT4 levels were comparable with the adult range by 28 weeks' gestation; TBG levels reached adult values at approximately 30 weeks, while TT4 was lower than adult levels throughout the whole period studied. TSH values were, in all cases, higher than the normal adult range. A significant positive correlation was present between TT4 and TBG, TT4 and TSH, and TBG and TSH levels; on the contrary, no correlation was demonstrated between FT4 and TSH levels. The TSH/TT4 ratio significantly decreased with gestational age. The results suggest an incomplete responsiveness of the foetal thyroid gland to TSH, while the feedback control system between pituitary and thyroid is operating at a different set point from that in post-natal life. The normal range of thyroid parameters established is of clinical relevance for the antenatal diagnosis, and eventual treatment of thyroid disorders that may seriously damage foetal development and maturation.

Effect of maternal hypothyroxinaemia during fetal life on the calmodulin-regulated phosphatase activity in the brain of the adult progeny in the rat.

Calmodulin-regulated phosphatase activity was measured in the brain of 2-month-old rats born from hypothyroid and normal dams, using a fluorometric enzyme assay developed for this purpose. Calmodulin content was measured in the same brain regions by radioimmunoassay. Significant differences between groups in weight and protein content, basal phosphatase and calmodulin-regulated phosphatase activity were found. The brain region most affected was the cerebellum, where basal and calmodulin-regulated phosphatase activities, and protein content were increased. The data point towards a lasting effect of maternal hypothyroxinaemia on the brain function of the progeny.

Silent ovulation in rhesus monkeys (M. mulatta): dissociation of hormonal and behavioral states.

Ovarian hormone levels were monitored in rhesus monkeys during the breeding and non-breeding seasons. Ovulation (as inferred from progesterone levels in blood serum in excess of 1.5 ng/ml) was most frequent in the breeding season but was absent only during the month of August. Summer (non-breeding season) ovulations were more frequently "silent," or without heterosexual behavior, than were winter ovulations. This finding suggested that estradiol stimulation may cause different behavioral responses at different times of the year. To test this hypothesis, ovariectomized females were treated with subcutaneously implanted estradiol capsules at different times within and outside the normal breeding season. In either season, treatment with estradiol resulted in increased female-to-female sexual behavior. Only during the breeding season, however, did the estradiol-treated ovariectomized females interact sexually with males. Although males copulated with both estradiol-treated and gonadally intact, untreated females during the breeding season, their rate of copulation with the intact females was higher. The results suggest that: (1) Some female rhesus monkeys displaying strictly seasonal breeding behavior continue to have luteal activity indicative of ovulation in May, June and July, (2) Summer ovulatory cycles are rarely accompanied by sexual behavior, (3) Estradiol treatment of ovariectomized females induces female-to-female sexual behavior both in the breeding and non-breeding seasons, and (4) Males are less responsive to the presence of estrogen-stimulated females in the non-breeding season than in the breeding season.

A backpack system for long-term osmotic minipump infusions into unrestrained marmoset monkeys.

A backpack system is described whereby osmotic minipumps are used to infuse gonadotrophin-releasing hormone (GnRH) subcutaneously in a pulsatile manner into infertile socially subordinate female marmoset monkeys (Callithrix jacchus jacchus). This procedure enables long-term infusion of GnRH without the necessity of repeated subcutaneous implantation of pumps and GnRH reservoirs. The backpack and cannulae system is inexpensive and can be constructed from commonly available materials. The GnRH treatment successfully overcame the suppression of pituitary luteinizing hormone secretion imposed by the low social status of female marmoset monkeys.

Resumption of seasonal breeding patterns in male and female rhesus monkeys transferred from an indoor to an outdoor environment.

Seasonal aspects of social behavior and sex steroid levels were observed in two groups of rhesus monkeys from March through December. One group (3 males, 7 females) had lived outdoors for several years. The other group (6 males, 5 females), transferred outdoors in late February, had lived indoors for several years. In March-April, the long-term outdoor residents displayed the expected seasonal pattern of sexual behavior, characterized by absence of complete sequences of copulatory behavior. At this time the indoor-adapted group displayed high levels of copulatory behavior. Thereafter, frequencies of sexual behavior of the two groups were similar. Testosterone in the males was positively correlated with frequency of sexual behavior in each group. Females in the indoor-adapted group displaced menstrual cycles in March and April and 3 of 5 became pregnant at this time. The two remaining indoor-adapted females continued to display ovulatory cycles, but little sexual behavior, throughout the summer. Interestingly, two females in the outdoor-adapted group also displayed summer ovulatory cycles; without concomitant sexual activity. These data show that the disruption of seasonal breeding patterns produced by lengthy indoor housing remains briefly apparent following transfer outdoors, but is substantially overcome within a few months.

Effect of estradiol-treated females on all-female groups of rhesus monkeys during the transition between the nonbreeding and breeding seasons.

Behavior, sex steroid levels and sex skin color were monitored in 2 out-door-housed all-female groups of rhesus monkeys during the nonbreeding season and into the breeding period. Each group contained gonadally intact and ovariectomized (OVX) females. In one group, 2 OVX females were implanted with estradiol benzoate pellets. Female-to-female sexual behavior, sex skin redness and endocrine indices of ovulation (in intact females) all increased as the breeding season approached. The two groups did not differ with regard to these measures. This lack of difference suggests that the presence of males may be required to mediate socially facilitated out-of-season breeding by females. No strong relationships were detected between steroid levels of intact females and sex skin color or female-to-female sexual behavior in all-female groups.

Influence of estrogen-treated females on sexual behavior and male testosterone levels of a social group of rhesus monkeys during the nonbreeding season.

The effect of the sequential estradiol benzoate treatment of each of 6 ovariectomized (OVX) females on a social group of rhesus monkeys was examined during the period from May to August. The group was housed outdoors and was composed of 7 adult males and 5 intact females, in addition to the 6 OVX animals. Social behavior was observed and male testosterone levels were monitored before, during and after estrogen treatment of the OVX females. Behavior of an unmanipulated group was also examined, and no sexual behavior occurred in this control group from May through August. In contrast, the sexual behavior of both males and gonadally intact females of the experimental group increased when estrogen-treated females were present. Sexual behavior remained elevated after the estrogen-treated females had been removed and continued so into the breeding season. The sexual behavior of the untreated females was displayed in cycles about 26 days in length. Male testosterone levels increased to values typical of the breeding season. Aggressive and submissive behavior also increased during the treatment. These results confirm previous findings about the influence of estrogen-treated females on male sexual behavior, and present the first direct evidence of increased testosterone levels in this situation. In addition, the data suggest that the presence of estrogen-treated females can induce sexual behavior in the other females of the same social group.