Utilisation of prophylactic mastectomy in 10 European centres

Increasingly women at high risk of breast cancer are opting for prophylactic surgery to reduce their risks. Data from 10 European centres that offer a risk counselling and screening service to women at risk show different approaches to the option of preventive surgery, although most centres adhere to a protocol including at least two risk counselling sessions and a psychological assessment. Thus far the combined centres have data on 174 women who have undergone prophylactic mastectomy with in excess of 400 women years of follow up. Operations were carried out on women with lifetime risks of 25-80%, with an average annual expected incidence rate of 1% per women. No breast cancers have occurred in this cohort. Long term follow up on an extended group of women will be necessary to truly address the risk of subsequent breast cancer and the psychological sequelae.

Determinants of increased energy expenditure in HIV-infected women

BACKGROUND

Little is known about sex-specific effects of HIV infection on energy expenditure.

OBJECTIVE

We investigated the determinants of energy expenditure in HIV-infected women.

DESIGN

Resting energy expenditure (REE), body composition, and hormonal and nutritional indexes were compared in 33 ambulatory, premenopausal HIV-infected women and 26 weight-matched, healthy premenopausal control subjects. REE was determined by indirect calorimetry and body composition by dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis, and skinfold-thickness analysis. Hormonal indexes included leptin, testosterone, estradiol, and insulin-like growth factor I.

RESULTS

HIV-infected subjects had a higher REE than control subjects [6794 +/- 1374 compared with 6011 +/- 607 kJ/d (1624 +/- 329 compared with 1437 +/- 145 kcal/d), P = 0.0096]. On average, REE was 119 +/- 23% of Harris-Benedict predictions in HIV-infected subjects compared with 102 +/- 9% for control subjects (P = 0.0007). In HIV-infected subjects, REE was highly correlated with fat-free mass (FFM) by DXA (R = 0.641, P < 0.001), but not with weight or disease status. The slope of the regression equation for REE and FFM was significantly greater (P = 0.027, analysis of covariance) for HIV-infected subjects [REE (kJ/d) = 203.5 (kg FFM) - 1237] than for control subjects [REE (kJ/d) = 77.4 (kg FFM) + 2923]. In a stepwise regression analysis, FFM was the most significant variable (P = 0.005), followed by free testosterone (P = 0.029), which together explained 49% of the variation in REE. The final equation was REE (kJ/d) = 230.8 (kg FFM) + 395.9 (free testosterone, pmol/L) - 3304.

CONCLUSIONS

Energy expenditure was higher in HIV-infected women than in control women. FFM is the primary determinant of REE in HIV-infected women, but energy expenditure is greater per kg FFM in HIV-infected subjects than in control subjects, which may contribute to the wasting syndrome.

Characterization of Ke 6, a new 17beta-hydroxysteroid dehydrogenase, and its expression in gonadal tissues

The abnormal regulation of the Ke 6 gene has been linked to the development of recessive polycystic kidney disease in the mouse. In this report, we have shown that Ke 6 is a 17beta-hydroxysteroid dehydrogenase and can regulate the concentration of biologically active estrogens and androgens. The Ke 6 enzyme is preferentially an oxidative enzyme and inactivates estradiol, testosterone, and dihydrotestosterone. However, the enzyme has some reductive activity and can synthesize estradiol from estrone. We find that the Ke 6 gene is expressed within the ovaries and testes. The presence of Ke 6 protein within the cumulus cells surrounding the oocyte places it in a strategic location to control the level of steroids to which the egg is exposed. Previously, it had been shown that glucocorticoids can induce renal cysts in the neonatal rodent, only when given at a narrow time window of postnatal kidney development. We propose that the reduction in the level of Ke 6 enzyme, which occurs in the cpk, jck, and pcy mice, may lead to abnormal elevations in local level of sex steroids, which either directly or indirectly via abnormal glucocorticoid metabolism result in recessive renal cystic disease, a developmental disorder of the kidney.

A statewide survey of immunization rates in Minnesota school age children: implications for targeted assessment and prevention strategies

BACKGROUND

A retrospective statewide immunization survey of the 69115 Minnesota children who entered kindergarten in 1992 was conducted.

METHODS

Information was collected from school immunization records on date of birth, dates of vaccination for each dose of vaccine, address of residence and race/ethnicity (when available). Immunization rates were assessed retrospectively for each month of a child's life from 2 to 48 months of age. Age-appropriate immunization was defined as receipt of all scheduled vaccines within 30 days of the recommended age.

RESULTS

Immunization levels varied by vaccine, age of the child and race/ethnicity. For example at 19 months of age, 73% of students had received measles, mumps, rubella vaccine; however, only 39% had received their fourth dose of diphtheria, tetanus and pertussis vaccine. White, non-Hispanic students consistently had higher vaccination rates than children of other racial/ ethnic groups. For example 45% of white, non-Hispanic students were age-appropriately vaccinated at 16 months of age compared with 25% of Blacks, 30% of American Indians, 30% of white Hispanics and 28% of Asian-Pacific Islanders (Mantel-Haenzel chi square, P < 0.001 for each comparison). Furthermore coverage rates frequently varied significantly by neighborhood, thereby identifying pockets of underimmunization within communities.

CONCLUSION

Our data demonstrate that vaccination rates can vary substantially by age, race/ ethnicity and neighborhood. Detailed immunization assessment is necessary so that effective targeted interventions can be developed.

Transdermal testosterone administration in women with acquired immunodeficiency syndrome wasting: a pilot study

Although human immunodeficiency virus (HIV) disease is increasing rapidly among women, no prior studies have investigated gender-based therapeutic strategies for the treatment of acquired immunodeficiency syndrome (AIDS) and its complications in this population. Markedly decreased serum androgen levels have been demonstrated in women with AIDS and may be a contributing factor to the wasting syndrome in this population. To assess the effects of androgen replacement therapy in women with AIDS wasting, we conducted a randomized, placebo-controlled, pilot study of transdermal testosterone administration. The primary aim of the study was to determine efficacy in terms of the change in serum testosterone levels, safety parameters and tolerability. A secondary aim of the study was to investigate testosterone effects on weight, body composition, quality of life, and functional indexes. Fifty-three ambulatory women with the AIDS wasting syndrome defined as weight less than 90% of ideal body weight or weight loss of more than 10% of the preillness maximum, free of new opportunistic infection within 6 weeks of study initiation, and with screening serum levels of free testosterone less than the mean of the normal reference range (< 3 pg/mL) were enrolled in the study. Subjects were age 37 +/- 1 yr old (mean +/- SEM), weighed 92 +/- 2% of ideal body weight, and had lost 17 +/- 1% of their maximum weight. CD4 count was 324 +/- 36 cells/mm3, and viral burden was 102,382 +/- 28,580 copies. Subjects were randomized into three treatment groups, in which two placebo patches (PP), one active/one placebo patch (AP group), or two active patches (AA group) were applied twice weekly to the abdomen for 12 weeks. The expected nominal delivery rates of testosterone were 150 and 300 microg/day, respectively, for the AP and AA groups. Forty-five subjects completed the study (PP group, n = 13; AP group, n = 14; AA group, n = 18). Two additional subjects from the PP group and two from the AP group were included in the intent to treat analysis. Serum free testosterone levels increased significantly from 1.2 +/- 0.2 to 5.9 +/- 0.8 pg/mL (AP) and from 1.9 +/- 0.4 to 12.4 +/- 1.6 pg/mL (AA) in response to testosterone administration (P < 0.0001 for comparison of AA vs. PP and AP vs. PP; normal range, 1.3-6.8 pg/mL). Testosterone administration was generally well tolerated locally and systemically, with no adverse trends in hirsutism scores, lipid profiles, or liver function tests. Weight increased significantly in the AP group (1.9 +/- 0.7 kg) vs. the PP group (0.6 +/- 0.8 kg; P = 0.043), but did not increase significantly in the AA group (0.9 +/- 0.4 kg; P = 0.263 vs. PP, by mixed effects model assessing the interaction of time and treatment on all available data, one-tailed test). Improved social functioning (P = 0.024, by one-tailed test) and a trend toward improved pain score (P = 0.059) were observed in the AP vs. the PP-treated patients (RAND 36-Item Health Survey questionnaire). Five of six previously amenorrheic patients in the AP group had spontaneous resumption of menses compared to only one of four amenorrheic patients in the AA group (P = 0.045 for comparison of actual number of periods during the study). This study is the first investigation of testosterone administration in women with AIDS wasting. We demonstrate a novel method to augment testosterone levels in such patients that is safe and well tolerated during short term administration. At the lower of the two doses administered in this study, testosterone therapy was associated with positive trends in weight gain and quality of life. Higher, more supraphysiological, dosing was not associated with positive trends in weight or overall well-being. These data suggest that testosterone administration may improve the status of women with AIDS wasting. Further studies are needed to assess the effects of testosterone on weight in HIV-infected women and to define the optimal therapeutic window for test

Glucocorticoid pretreatment reduces the cytotoxic effects of a variety of DNA-damaging agents on rat tibial growth-plate chondrocytes in vitro

It is apparent that cytotoxic chemotherapy used to treat childhood malignancies has a major impact on subsequent growth. Our initial studies have demonstrated a direct adverse effect of individual glucocorticoids and cytotoxic agents on the proliferative capacity of rat tibial growth-plate chondrocytes in vitro. In the present study we investigated the interaction between these classes of agents using in vitro cultures of chondrocytes and examined the potential of these cells to recover from the adverse effects of the drugs as applied either alone or in combination. The glucocorticoids prednisolone and dexamethasone significantly reduced the growth rate of chondrocytes when present in cultures for 3 days. The growth rate increased following the removal of prednisolone and dexamethasone from cultures and reached 83.9+/-0.8% and 62.4+/-4.0%, respectively, of the control values after 11 days of culture. In contrast, cell numbers were significantly reduced when the DNA-damaging agents cisplatin, carboplatin, etoposide or actinomycin-D were present in cultures for 3 days. Very little recovery of cell growth was observed after removal of the drugs from cultures, with cell loss occurring in the cisplatin- and actinomycin-D-treated cultures. However, pretreatment of chondrocytes with either of the glucocorticoids completely ameliorated the cytotoxic effects of etoposide and carboplatin and significantly reduced those of cisplatin and actinomycin-D. Recovery of the cells treated with a combination of glucocorticoid and DNA-damaging agent was demonstrated by a significant increase in their ability to form colonies in suspension culture. Colony numbers were increased by a factor of between 5 and 80 as compared with the cells receiving medium alone followed by DNA-damaging agent. The glucocorticoids offer a protective effect in terms of the reduced cytotoxicity of DNA-damaging agents and improve the subsequent clonogenicity and recovery of growth-plate chondrocytes. This has important implications for treatment schedules involving both cytotoxic agents and glucocorticoids in childhood malignancies.

Effects of androgen administration in men with the AIDS wasting syndrome. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Development of successful anabolic strategies to reverse the loss of lean body mass is of critical importance to increase survival in men with the AIDS wasting syndrome. Hypogonadism, an acquired endocrine deficiency state characterized by loss of testosterone, occurs in more than half of all men with advanced HIV disease. It is unknown whether testosterone deficiency contributes to the profound catabolic state and loss of lean body mass associated with the AIDS wasting syndrome.

OBJECTIVE

To investigate the effects of physiologic testosterone administration on body composition, exercise functional capacity, and quality of life in androgen-deficient men with the AIDS wasting syndrome.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

University medical center.

PATIENTS

51 HIV-positive men (age 42 +/- 8 years) with wasting (body weight < 90% of ideal body weight or weight loss > 10% of baseline weight) and a free testosterone level less than 42 pmol/L (normal range for men 18 to 49 years of age, 42 to 121 pmol/L [12.0 to 35.0 pg/mL]).

INTERVENTION

Patients were randomly assigned to receive testosterone enanthate, 300 mg, or placebo intramuscularly every 3 weeks for 6 months.

MEASUREMENTS

Change in fat-free mass was the primary end point. Secondary clinical end points were weight, lean body mass, muscle mass, exercise functional capacity, and change in perceived quality of life. Virologic variables were assessed by CD4 count and viral load.

RESULTS

Compared with patients who received placebo, testosterone-treated patients gained fat-free mass (-0.6 kg and 2.0 kg; P = 0.036), lean body mass (0.0 kg and 1.9 kg; P = 0.041), and muscle mass (-0.8 kg and 2.4 kg; P = 0.005). The changes in weight, fat mass, total-body water content, and exercise functional capacity did not significantly differ between the groups. Patients who received testosterone reported benefit from the treatment (P = 0.036), feeling better (P = 0.033), improved quality of life (P = 0.040), and improved appearance (P = 0.021). Testosterone was well tolerated in all patients.

CONCLUSIONS

Physiologic testosterone administration increases lean body mass and improves quality of life among androgen-deficient men with the AIDS wasting syndrome.

Decreased leptin levels in normal weight women with hypothalamic amenorrhea: the effects of body composition and nutritional intake

Leptin is a protein encoded by the ob gene and expressed in adipocytes. A sensitive marker of nutritional status, leptin is known to correlate with fat mass and to respond to changes in caloric intake. Leptin may also be an important mediator of reproductive function, as suggested by the effects of leptin infusions to restore ovulatory function in an animal model of starvation. We hypothesized that leptin levels are decreased in women with hypothalamic amenorrhea and that leptin may be a sensitive marker of overall nutritional status in this population. We, therefore, measured leptin levels and caloric intake in 21 women with hypothalamic amenorrhea (HA) and 30 age-, weight-, and body fat-matched eumenorrheic controls. Age (24 +/- 5 vs. 24 +/- 3 yr), body mass index (20.6 +/- 1.3 vs. 21.1 +/- 1.5 kg/m2), percent ideal body weight (94.9 +/- 5% vs. 96.3 +/- 6.3%), and fat mass (14.2 +/- 3.6 vs. 15.5 +/- 2.9 kg, determined by dual energy x-ray absortiometry) did not differ between the groups. Leptin levels were significantly lower in the HA subjects compared with those in the controls (7.1 +/- 3.0 vs. 10.6 +/- 4.9 micrograms/L; P = 0.005). Total caloric intake (1768 +/- 335 vs. 2215 +/- 571 cal/day; P = 0.003), fat intake (333 +/- 144 vs. 639 +/- 261 cal/day; P < 0.0001), and insulin levels (5.6 +/- 1.2 vs. 7.4 +/- 3.2 microU/mL; P = 0.015) were lower in the women with HA than in the eumenorrheic controls. The difference in leptin levels remained significant after controlling for insulin (P = 0.023). These data are the first to demonstrate hypoleptinemia, independent of fat mass, in women with HA. The hypoleptinemia may reflect inadequate calorie intake, fat intake, and/or other subclinical nutritional disturbances in women with HA. The mechanism and reproductive consequences of low leptin in this large population of women remain unknown.

The pathogenesis of African swine fever in the resistant bushpig

Bushpigs and warthogs are natural reservoir hosts of African swine fever virus (ASFV) in the wild, showing no clinical signs of disease when infected with the same highly virulent isolates of ASFV that induce rapid, haemorrhagic death in domestic pigs. In contrast to domestic pigs, infection of bushpigs with Malawi isolate results in low levels of virus replication and lymphocyte apoptosis within the spleen, and a relatively low spread of virus to other lymphoid tissues. However, at 10 days post-infection, a high degree of apoptosis was seen in B lymphocytes of the B cell follicles in bushpig lymph nodes. Virus infected cells were present amongst the apoptotic B cells of these follicles, suggesting that indirect factors released from ASFV infected macrophages signal surrounding lymphocytes to enter apoptosis. The susceptibility/resistance of domestic pigs/bushpigs to ASFV may serve as a unique veterinary model for the recently emerging haemorrhagic disease of man.

Imaging soft X-ray microscope at Rits Synchrotron Radiation Center

An imaging soft X-ray microscope with zone plates has been installed at Rits SR Center (Ritsumeikan University, Kusatsu, Japan). With this microscope, specimens were set in air, which made it possible to investigate the specimens without breaking the vacuum of the microscope. The specimens can be prefocused with an optical microscope. Dry and wet biospecimens in air were observed. A new optical system was designed to improve the resolution.

Chemotherapeutic agents used in the treatment of childhood malignancies have direct effects on growth plate chondrocyte proliferation

Short stature is one of the most well recorded long term sequelae for adult survivors of childhood malignancies. It has become increasingly apparent that cytotoxic chemotherapy, as well as craniospinal irradiation, has a major impact on growth, but there are virtually no studies which explore the mechanisms by which these cytotoxic drugs affect growth. We have used an in vitro system to investigate the direct effects of a range of chemotherapeutic agents on the proliferative responses of rat tibial growth plate chondrocytes, both in suspension and monolayer culture. The glucocorticoids and purine anti-metabolites reduced chondrocyte proliferation both in monolayer and suspension cultures and this resulted from an increase in cell doubling times with a concomittant reduction in the numbers of S phase cells. DNA damaging agents (e.g. actinomycin-D) were also able to reduce chondrocyte proliferation, both in monolayer and suspension culture. This, however, was the result of a cell cycle arrest and subsequent cell death. In our studies, methotrexate had no significant effect on the proliferative responses of the chondrocytes either in monolayer or suspension culture. These results indicate direct effects of a range of chemotherapeutic agents on the proliferative responses of growth plate chondrocytes. Both cytostatic and cytotoxic effects were observed although the impact of either the potential loss of cells from the proliferative pool during chondrocyte differentiation, or the reduction in the rate of chondrocyte turnover on long bone growth remains to be elucidated.

Effect of Cheyne-Stokes respiration on muscle sympathetic nerve activity in severe congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

Severe congestive heart failure (CHF) is associated with Cheyne-Stokes (C-S) respiration, which may be an index of poorer prognosis. The mechanisms linking C-S respiration to poorer functional status and prognosis in patients with CHF are unknown. We tested the hypothesis that C-S respiration increases muscle sympathetic nerve activity (MSNA) in 9 patients with CHF. Oxygen saturation was 96 +/- 1% during normal breathing and 91 +/- 1% after the apneic episodes (p < 0.05). Mean blood pressure was 79 +/- 8 mm Hg during normal breathing and 85 +/- 8 mm Hg during C-S respiration (p = 0.001). C-S respiration increased MSNA burst frequency (from 45 +/- 5 bursts/min during normal breathing to 50 +/- 5 bursts/min during C-S respiration; p < 0.05) and total integrated nerve activity (to 117 +/- 7%; p < 0.05). We also studied an additional 5 patients in whom C-S breathing was constant, without any periods of spontaneous normal breathing. In these patients, MSNA was higher (65 +/- 5 bursts/min) than MSNA in patients in whom C-S breathing was only intermittent (45 +/- 5 bursts/min; p < 0.05). In all 14 patients, the effects of different phases of C-S respiration were examined. MSNA was highest during the second half of each apnea (increasing to 152 +/- 14%; p < 0.01) and blood pressure was highest during mild hyperventilation occurring after termination of apnea (p < 0.0001). We conclude that C-S respiration decreases oxygen saturation, increases MSNA, and induces transient elevations in blood pressure in patients with CHF.

Multidrug resistance gene expression correlates with progesterone production in dehydroepiandrosterone-induced polycystic and equine chorionic gonadotropin-stimulated ovaries of prepubertal rats

Polycystic ovaries (PCO) can be induced in prepubertal rats by daily injection of dehydroepiandrosterone (DHEA). There are high levels of progesterone, androgens, and estrogens in the cystic fluid of DHEA-treated rat ovaries. The purpose of this study was to investigate whether high levels of steroids in the PCO correlate with the expression of multidrug resistance gene product P-glycoprotein (Pgp). Using C219, a monoclonal antibody that recognizes the 170-kDa ATP-dependent transmembrane pump, we localized Pgp on the plasma membrane of granulosa cells in cystic follicles but not of oocytes or thecal/interstitial cells. In normal prepubertal rats, Pgp was localized in progesterone-producing granulosa cells of the preovulatory follicles and in cells of the corpora lutea after eCG/hCG stimulation, but not in growing follicles, oocytes, or thecal/interstitial cells. Northern analysis of these tissues indicated strong expression of Pgp mRNA in the preovulatory follicles, cystic follicles, and corpora lutea. From these findings it seems that progesterone produced by the granulosa cells may act in an autocrine manner to induce the expression of Pgp. It may be possible that progesterone interacts with the Pgp of these granulosa cells to modulate steroid efflux.

Estrogen responsiveness and control of normal human breast proliferation

Our understanding of the hormonal control of the proliferation of normal human breast epithelium is still surprisingly meager. However, the results of a number of recent studies have confirmed that estrogen is the major steroid mitogen for the luminal epithelial cell population (the usual targets for neoplastic transformation). Estrogen seemingly exerts its effects on cell division indirectly as there is complete dissociation between the population of luminal epithelial cells expressing the estrogen receptor (ER)4 and those that proliferate. We suggest that the ER-negative proliferating cells represent a precursor or stem cell population that differentiates to ER-containing, nonproliferative cells. In turn, these ER-positive cells act as 'estrogen sensors' and transmit positive or negative paracrine growth signals to the precursor cells depending on the prevailing hormonal environment. As yet there is no direct evidence supporting this hypothesis but we suggest ways in which it may be obtained. The implication of these studies is that inhibition of luminal epithelial proliferation with tamoxifen or pure antiestrogens or by preventing ovarian steroid secretion should be an effective strategy for the prevention of breast cancer. In addition, we may be able to predict the risk of breast cancer in an individual by measuring the intrinsic estrogen sensitivity of her breast epithelium. Finally, study of the paracrine mechanisms of growth control in the normal human breast may provide new, more specific, therapeutic targets for breast cancer prevention.

Influence of dehydroepiandrosterone on the expression of insulin-like growth factor-1 during cystogenesis in polycystic rat ovaries and in cultured rat granulosa cells

This study was designed to investigate the expression of insulin-like growth factor-1 (IGF-1) during cystogenesis in the dehydroepiandrosterone (DHEA)-induced rat polycystic ovarian syndrome (PCO) model. IGF-1 expression patterns in DHEA-treated rat ovaries were compared with those in control ovaries. In situ hybridization revealed a similar distribution of IGF-1 mRNA in DHEA-treated and control ovaries: in both, IGF-1 mRNA expression was confined to the granulosa cells of preantral and small antral follicles. Some hybridization signals for IGF-1 mRNA were also found in theca and infrequently in the interstitial cells. No signal was observed in larger antral follicles, atretic follicles, or cysts. This similarity indicates that there might be a shared mechanism in the early follicular development of normal folliculogenesis and DHEA-induced cystogenesis. The effects of DHEA on granulosa cells were analyzed in vitro in their quiescent, proliferative, differentiative, and preovulatory stages. Northern analysis revealed three transcripts for IGF-1 (7.5 kilobases [kb], 1.6 kb, and a group of signals between 0.4 and 0.9 kb) in cells at all stages except the preovulatory. The strongest signal was observed in cells of the proliferative stage of control cultures, while expression of IGF-1 increased only in the DHEA-treated cells cultured in the differentiative stage (when they secrete estrogen). Increase in IGF-1 expression may contribute to the hypersteroidogenism observed in the DHEA-treated rat PCO model.

Dissociation between steroid receptor expression and cell proliferation in the human breast

We have shown previously that estradiol stimulates cell proliferation and progesterone receptor (PgR) synthesis in luminal epithelial cells of the normal human breast. Approximately 10-15% of luminal epithelial cells within the normal breast express immunodetectable estrogen receptor (ER), but little is known about their distribution within lobules and their organization in relation to the smaller population of proliferating cells. Using normal human breast tissue, we show that ER-positive cells are distributed evenly throughout the mammary epithelium. Using double antibody immunofluorescence, we show that 96% of steroid receptor-positive cells synthesize both ER and PgR (n = 25). Double labeling with antibodies to either ER or PgR coupled with either [3H]thymidine histoautoradiography or with antibodies to the Ki67 proliferation antigen indicates that dividing cells are separate from those expressing the receptors (although they are often in close proximity). However, in contrast to the normal human breast, two-thirds of ER-positive human mammary tumors examined (n = 19) have a high proportion of dividing cells that are ER positive. These data are consistent with the hypothesis that cells in normal human breast epithelium are hierarchical in organization and support a model in which proliferation of ER-negative cells is controlled by paracrine factors released from ER-positive cells under the influence of estradiol. This organization may be disrupted in some tumors.

Estrogen sensitivity of normal human breast tissue in vivo and implanted into athymic nude mice: analysis of the relationship between estrogen-induced proliferation and progesterone receptor expression

High serum concentrations of estradiol (E2) equivalent to those observed in the luteal phase of the menstrual cycle stimulate both epithelial cell proliferation and progesterone receptor (PgR) expression in normal human breast tissue xenografted into athymic nude mice. We report here the results of further investigations designed to determine whether the induction of PgR expression and proliferation require different E2 concentrations and whether proliferating cells expressed the PgR. In untreated normal breast xenografts, the PgR was virtually undetectable and proliferation was at basal levels. Progesterone (Pg) treatment alone had no effect compared to no treatment. Treatment with E2 at follicular phase serum concentrations maximally increased PgR expression but was without effect on proliferation. However, treatment with E2 at luteal phase serum concentrations, alone or in combination with Pg, significantly increased both the PgR content and the proliferation of the breast epithelium. These experimentally derived data reflected the observations made on normal breast tissue at surgical biopsy where PgR content was similar in both halves of the menstrual cycle, whereas proliferation was significantly higher in the luteal phase. Finally, using double labelling techniques, it was demonstrated that proliferating epithelial cells rarely expressed PgR in normal breast tissue obtained at surgical biopsy. These results suggest that the threshold of E2 required to induce PgR expression in normal human breast epithelial cells is lower than that required to induce proliferation and that the majority of proliferating breast cells do not express the PgR.

Polycystic ovarian condition in the dehydroepiandrosterone-treated rat model: hyperandrogenism and the resumption of meiosis are major initial events associated with cystogenesis of antral follicles

BACKGROUND

The purpose of this study was to elucidate the early effects of dehydroepiandrosterone (DHEA) in the polycystic rat model by charting cytological changes in the early antral follicle of the ovary and constructing a serum hormonal profile. Histological examinations of ovaries from DHEA-treated rats for ten consecutive days revealed that the oocyte of antral follicles, ranging from 1.5 mm to 3.4 mm in diameter, had become activated, i.e., had resumed meiosis. Tabulation and statistical analysis revealed a highly significant difference in the percentage of oocyte activation between the ovaries of DHEA-treated and control rats. Granulosa cells associated with those antral follicles included in our statistical analysis showed no evidence of atresia. A few follicles not included in our analysis contained oocytes that had resumed meiosis and whose associated granulosa cells were atretic. The observed resumption of meiosis occurred in the absence of surges of follicle stimulating hormone (FSH) and luteinizing hormone (LH). During meiosis, a period when many oocytes become activated, levels of serum androgens (DHEA, testosterone, and androstenedione) were high, while FSH, LH, and prolactin (PRL) levels did not differ significantly from those in the controls. Follicles that resume meiosis may be members of a group of follicles that produces a signal(s) when the oocyte becomes uncoupled from the granulosa cell. This signal(s) permit(s) a reprogramming of the accompanying granulosa cells of the follicle to engage in certain developmental processes of cystogenesis. Just what cascade of signals is necessary to achieve this selection remains elusive at this time and is the subject of our continuing investigations.

Induction of apoptosis by tamoxifen and ICI 182780 in primary breast cancer

Hormonal breast cancer therapies have traditionally been considered cytostatic, but recent pre-clinical data suggest that anti-oestrogens can induce apoptosis. The aim of this study was to assess whether tamoxifen (TAM) and ICI 182780 (ICI) could induce apoptosis in human breast cancer, and whether this was related to oestrogen receptor status. We measured apoptosis in primary breast cancer patients before and after pre-surgical treatment with 20 mg/day TAM (study 1) or 6 or 18 mg/day ICI (study 2). In each study there was a randomised non-treatment (NT) control group. TAM significantly increased apoptotic index (AI) in ER+ but not in ER- tumours. There was a significant increase in AI following treatment with ICI. Insufficient pairs of samples were available to determine whether this change was confined to ER+ tumours, but in a cross-sectional analysis AI was significantly higher in excision biopsies for ICI-treated than NT patients for ER+ but not ER- tumours. Our results provide clinical evidence that apoptosis may be induced in ER+ primary breast cancer by both non-steroidal and steroidal anti-oestrogens.

Assessment of hormone dependence of comedo ductal carcinoma in situ of the breast

BACKGROUND

Ductal carcinoma in situ (DCIS) represents 20%-30% of breast cancers detected by clinical screening (i.e., mammography). More than 50% of DCIS lesions may be estrogen receptor negative and, therefore, hormone independent. However, the role of estrogen in the natural history of DCIS is unknown.

PURPOSE

A novel in vivo (i.e., xenograft) model was developed to determine to what degree DCIS lesions depend on estrogen for growth.

METHODS

Specimens of breast tissue were collected from 52 women during diagnostic or therapeutic surgical procedures. Portions of each specimen were randomly selected and analyzed by histology and thymidine labeling (to measure cell proliferation). The remainder of each specimen was implanted into five to 18 athymic BALB/c nu/nu mice (depending on the amount of tissue available), with eight pieces of approximately 2 mm x 2 mm x 1 mm implanted at different locations on the back of each mouse. Half of the mice received implants containing estrogen (2 mg 17 beta-estradiol), and the other half received placebo implants. Levels of cell proliferation in xenografts, recovered after 14, 28, 42, or 56 days in the mice, were measured by thymidine labeling or by immunohistochemistry through use of an antibody specific for the Ki-67 nuclear antigen. Immunohistochemistry was also used to measure the levels of estrogen receptor in the tissue specimens. Serum 17 beta-estradiol levels in the mice were measured by radioimmunoassay.

RESULTS

Initial levels of cell proliferation were approximately 10-fold higher in 10 specimens with estrogen receptor-negative, comedo (i.e., more malignant in appearance) DCIS than in four specimens with estrogen receptor-positive DCIS (mean proliferation indices: 22% versus 1.9%, respectively; two-sided P < .001). Xenografts from the majority of specimens survived up to 56 days in the mice and maintained good architectural and cellular preservation. Estrogen treatment of the xenograft-bearing mice had no effect on the high level of cell proliferation observed in estrogen receptor-negative, comedo DCIS specimens (two-sided P = .89). In contrast, increased levels of cell proliferation in response to estrogen supplementation were measured in three estrogen receptor-positive, noncomedo DCIS specimens (two-sided P < .001). However, even with estrogen treatment, cell proliferation levels in estrogen receptor-positive DCIS specimens did not reach those seen in estrogen receptor-negative DCIS specimens.

CONCLUSION AND IMPLICATION

Estrogen receptor-negative, comedo DCIS lesions appear to be estrogen independent; therefore, antiestrogen (e.g., tamoxifen) therapy may not benefit patients with comedo DCIS.

The polycystic ovarian (PCO) condition: apoptosis and epithelialization of the ovarian antral follicles are aspects of cystogenesis in the dehydroepiandrosterone (DHEA)-treated rat model

This investigation was designed to study apoptosis and epithelialization during cystogenesis of the dehydroepiandrosterone rat model. Using in situ DNA 3'- end-labeling with non-radioactive digoxigenindidesoxy-UTP (dig-ddUTP), apoptosis is initially seen in cumulus granulosa cells and other granulosa cells facing the antrum. During cystogenesis, apoptosis systematically progresses from the cumulus towards the mural granulosa layer. In contrast, granulosa cells of atretic follicles undergo apoptosis in a random manner. The outer layer of mural granulosa cells during cystogenesis escapes apoptosis. Granulosa cells contain vimentin. However, the outer mural granulosa cell layer that lines the cyst acquires keratin. In addition to being associated with each other via gap junctions, the outer layer of granulosa cells acquire tight junctions. With the characterization of the transformation of the outer mural granulosa cells into a characteristic epithelium and the orderly progression of apoptosis, we further the understanding of the multifaceted process of cystogenesis of the ovarian antral follicle.

Differential influence of TGFbeta1 and TGFbeta3 isoforms on cell cycle kinetics and postirradiation recovery of normal and malignant colorectal epithelial cells

PURPOSE

A clonogenic assay was used to determine the effects of the growth factors TGFbeta1 and TGFbeta3 on the radiation responses of a normal rat epithelial cell line (IEC6) and a human colonic carcinoma epithelial cell line (Widr).

METHODS AND MATERIALS

The radiation sensitivity and ability to recover from potentially lethal damage (PLD), of preconfluent monolayer cultures, was assessed in the presence of the growth factors for 24 h prior to, during, and after irradiation.

RESULTS

The surviving fractions of both cell lines assessed immediately following irradiation were unaffected by TGFbeta1 or TGFbeta3. However, TGFbeta3 (but not TGFbeta1) significantly reduced the amount of PLD recovery in the Widr cells (but not in the IEC6 cells). This was associated with a reduction in the shoulder region of the survival curve, rather than a change in slope. A comparative analysis of the effects of TGFbetas 1 and 3 on cell cycle events in the two cell lines demonstrated significantly more Widr cells in the S phase, in the presence of TGFbeta3 only, compared to the controls. This remained constant both before and immediately following irradiation. In the IEC6 cell line TGFbeta3 produced an increase in the numbers of G1 phase cells, characteristic of a G1 arrest.

CONCLUSION

It seems likely that TGFbeta3-induced radiosensitisation in Widr cells, 6 h after a single dose of irradiation, is related to its effects on cell cycle events such that the failure of these cells to arrest in G1, either before or after irradiation, results in significantly reduced recovery from DNA damage. This, however, may not be the only mechanism by which this growth factor produces this effect. Indeed, it will also be necessary to investigate these effects in in vivo models and to determine the response to fractionated irradiation before the potential therapeutic benefit of both the differential effects observed between the two TGFbeta isoforms and also between the malignant and normal cell lines can be fully assessed.

Steroidogenic acute regulatory (StAR) protein (p25) and prohibitin (p28) from cultured rat ovarian granulosa cells

This study has identified and characterized two intracellular proteins (25 and 28 kDa) during ongoing differentiation of rat granulosa cells isolated from preantral and early antral follicles. The identity of p25 was confirmed as the mitochondria associated StAR protein by western blotting analysis. In the culture conditions used, this protein was expressed only when granulosa cells were stimulated with FSH to produce progesterone. It is apparent that the steroidogenic differentiation of granulosa cells affects StAR expression. Amino acid sequence analysis of p28 identified it as prohibitin and was corroborated by western blot analysis with antibodies specific for rat prohibitin. During the ongoing differentiation of granulosa cells there were changes in the expression of p28/prohibitin. Although prohibitin is constitutively expressed in granulosa cells, there is an increase in the more acidic isoform of prohibitin when oestrogen concentrations are raised by increased production or exogenous addition. This increase in this acidic isoform of prohibitin is due to phosphorylation. It is possible that oestrogen induces phosphorylation of prohibitin and, thus, may be involved in the regulation of granulosa cell proliferation and the ontogeny of the ovarian follicle.

Modulation of mRNA levels in the presence of thymocytes and genome mapping for a set of genes expressed in mouse thymic epithelial cells

Modulation of gene expression in mouse thymic epithelium upon culture in the presence of thymocytes (coculture) was studied by comparison of hybridization signatures on a set of nearly 5000 mouse thymus cDNA clones. Forty-nine differentially expressed clones (usually down-regulated in coculture) were characterized by tag sequencing. Many of them corresponded to entities that had not been described previously in the mouse, and were further characterized by genome mapping. This set of genes appears to be involved in growth regulation and differentiation within the thymus.

Fish vaccine antigens produced or delivered by recombinant DNA technologies

Current efforts to develop vaccines, particularly for aquacultured species, have turned largely to biotechnology because it provides the means to inexpensively produce sufficient quantities of the immunoprotective antigen. These efforts have resulted in several prototype vaccines for fish and the publication of a large number of articles on the subject. However, there are only a few recombinant DNA-based vaccines for aquaculture in the licensing pipeline. Continued funding of research on recombinant DNA vaccines comes from the recognition by industry and government funding agencies that this research can lead to an increased understanding of the mechanisms in protective immunity. This is especially important for fish and shellfish species since our knowledge of the immune mechanisms in these animals is pitifully meagre. This presentation discusses the relative merits of the different recombinant DNA technologies that have been used to produce viral vaccines for fish and the promising approaches that are under consideration to increase the efficacy of these vaccines. There are many approaches to antigen production by recombinant DNA techniques including: (i) the preparation of purified antigenic proteins produced from the cloned viral genes in a variety of vector/host expression systems, (ii) chemical synthesis or the use of fusion vectors to produce peptides corresponding to known epitopes, (iii) defined attenuations, i.e. specific genetic alterations, of live virus vaccines, (iv) the use of live bacterial or viral vectors to deliver resistance genes or viral antigens, (v) anti-idiotype antibodies, and (vi) DNA vaccines where purified plasmid DNA expressing the pathogen gene under a eucaryotic promoter is injected. All of these technologies have been used more or less successfully in the development of vaccines for aquacultured species. However, the requirements for safety, effectiveness, ease of application and low cost/dose restrict their commercial development for aquaculture. The ideal viral vaccine for aquaculture must be effective in preventing death, be inexpensive to produce and license, provide immunity of long duration, and be easily administered. In addition, these vaccines must not only provide protection against the lethal effects of virus infection but prevent the formation of virus persistence. This is especially true for infectious haematopoietic necrosis virus (IHNV) which has been shown to persist in survivors in the presence of high antibody levels. Since resolution of virus persistence is thought to be correlate with cell-mediated immunity, vaccines designed to augment the cell-mediated immunity must be developed for fish. Approaches that are being considered include the use of cytokines in combination with subunit vaccines and the use of specific MHC-I inducer adjuvants with the vaccine. The "tailoring" of vaccine immunogenicity using different combinations of antigen and adjuvant will be presented.

Efficacy of twice weekly treatment for tuberculosis given under direct observation in Africa

The efficacy of a 6 months course of twice weekly therapy with 4 drugs for tuberculosis, preceded by a 2-3 weeks intensive daily phase, is unknown. Implementation of this regime as community-based directly observed therapy in Africa is highly effective (85% completion rate); it is important to estimate the efficacy of the regime before advocating its widespread use and before conducting prospective trials. We retrospectively evaluated 109 consecutive adults with culture-positive pulmonary tuberculosis who had documented completion of treatment; 84 (77%) were traced and in 15 (14%) a history was obtained from a close relative; 10 (9%) had left the area. Nineteen patients were producing sputum and 4 of these were culture-positive for Mycobacterium tuberculosis, giving an estimated cure rate of 95% (95% confidence interval, 89-98%). Follow-up specimens revealed no acquired drug resistance and restriction fragment length polymorphism analysis of patient-paired specimens showed them to be nearly identical, indicating that treatment had failed or there had been early relapse. This preliminary study suggested that generally twice weekly 4-drug treatment for tuberculosis, given under direct observation, is curative in an acceptable proportion of patients. Prospective trials are indicated.

Type I insulin-like growth factor receptor gene expression in normal human breast tissue treated with oestrogen and progesterone

The epithelial proliferation of normal human breast tissue xenografts implanted into athymic nude mice is significantly increased from basal levels by oestradiol (E2), but not progesterone (Pg) treatment at serum concentrations similar to those observed in the luteal phase of the human menstrual cycle. Type I IGF receptor (IGFR-I) mRNA and protein have been shown to be up-regulated by E2 in MCF-7 breast cancer cells in vitro in which IGF-I and E2 act synergistically to stimulate proliferation. We have investigated the expression of the IGFR-I mRNA in normal human breast xenografts treated with or without E2 or Pg alone and in combination. Northern analysis of 20 micrograms of RNA extracted from the breast xenograft samples showed no hybridization with 32P-labelled IGFR-I probe, although an 11-kb species of IGFR-I mRNA could be seen when 20 micrograms of RNA extracted from either MCF-7 breast cancer cells or human breast carcinomas was examined in this way. In order to analyse the expression of IGFR-I mRNA in breast xenografts, a quantitative reverse transcription-polymerase chain reaction (RT-PCR) was employed in which RNA loading, reverse transcription and PCR efficiencies were internally controlled. The data indicate that the IGFR-I mRNA is up-regulated by two to threefold compared with untreated levels by 7 and 14 days E2 treatment. In contrast, 7 or 14 days Pg treatment down-regulates the receptor mRNA to approximately half that of untreated levels, whereas combination E2 and Pg treatment produced a twofold increase in IGFR-I mRNA levels compared with untreated tissue. The results are consistent with the suggestion that E2 may act to stimulate proliferation indirectly via a paracrine mechanism involving IGFs in normal as well as malignant human breast epithelial cells.

The effects of dehydroepiandrosterone (DHEA) and its metabolites on the polycystic ovarian condition (PCO): cystogenic changes of rat granulosa cells in vitro

During mammalian folliculogenesis, granulosa cells (GCs) are initially steroidogenically quiescent, later proliferate, and subsequently commence to hormonally differentiate, first producing estrogen and later, in the preovulatory stage, secreting both estrogen and progesterone. In this study and elsewhere, we have used follicle-stimulating hormone with a combination of growth factors in vitro to simulate the above in vivo conditions. In a previous study, we used dehydroepiandrosterone (DHEA) to accomplish the polycystic ovary condition (PCO) in rats. In the latter model, there were high circulating levels of DHEA and its metabolite, androstenedione. In the present study, we investigated the effects of high levels of DHEA (10(-5) M) and its metabolites, androstenedione, androstenediol and dehydroepiandrosterone sulfate on the quiescent, proliferative, and steroidogenically differentiating stages of GCs cultured in a serum-free medium for up to 10 days. In addition to possessing the regularly occurring organelles, when cultured with the aforementioned androgens, the GCs acquired endoplasmic reticulum of the smooth variety which is associated with steroidogenesis. The radioimmunoassay data showed that GCs cultured in the quiescent and proliferative stages in the presence of the androgens, no longer remain in these stages but proceed to differentiate in a preovulatory direction by producing both estrogen and progesterone. This study supports our hypothesis that high circulating levels of DHEA and/or its metabolites have most effect during the quiescent and proliferative stages of granulosa cells, with regard to their structure and their steroidogenic activities.

High-dose chemotherapy supported by peripheral blood progenitor cells in poor prognosis metastatic breast cancer--phase I/II study. Edinburgh Breast Group

Current treatments for metastatic breast cancer are not associated with significant survival benefits despite response rates of over 50%. High-dose therapy with autologous bone marrow transplantation (ABMT) has been investigated, particularly in North America, and prolonged survival in up to 25% of women has been reported, but with a significant treatment-related mortality. However, in patients with haematological malignancies undergoing autologous transplantation, haematopoietic reconstruction is significantly quicker and mortality lower than with ABMT, when peripheral blood progenitor cells (PBPCs) are used. In 32 women with metastatic breast cancer, we investigated the feasibility of PBPC mobilisation with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) after 12 weeks' infusional induction chemotherapy and the subsequent efficacy of the haematopoietic reconstitution after conditioning with melphalan and either etoposide or thiotepa. PBPC mobilisation was successful in 28/32 (88%) patients, and there was a rapid post-transplantation haematopoietic recovery: median time to neutrophils > 0.5 x 10(9) l-1 was 14 days and to platelets > 20 x 10(9) l-1 was 10 days. There was no procedure-related mortality, and the major morbidity was mucositis (WHO grade 3-4) in 18/32 patients (56%). In a patient group of which the majority had very poor prognostic features, the median survival from start of induction chemotherapy was 15 months. Thus, PBPC mobilisation and support of high-dose chemotherapy is feasible after infusional induction chemotherapy for patients with metastatic breast cancer, although the optimum drug combination has not yet been determined.

Effects of short-term recombinant human insulin-like growth factor I administration on bone turnover in osteopenic women with anorexia nervosa

Significant osteoporosis affects over half of all women with anorexia nervosa (AN). The mechanisms of bone loss in this condition are not known, and estrogen administration alone has not been shown to prevent bone loss. Insulin-like growth factor I (IGF-I), a nutritionally dependent bone trophic hormone, is know to stimulate osteoblast function and collagen synthesis in vivo and in vitro. We hypothesized that short term administration of recombinant human IGF-I (rhIGF-I) would increase bone turnover in young women with AN. We studied 23 women, aged 18-29 yr (mean +/- SD, 23 +/- 4 yr) with AN. Spinal bone density was significantly reduced compared to that in age-matched controls (0.85 +/- 0.11 vs. 1.19 +/- 0.12 g/cm2 by dual energy x-ray absorptiometry; P < 0.001) and was below the normal mean in 54% of the women. Patients were randomized to receive rhIGF-I (100 or 30 micrograms/kg) or placebo sc twice a day for 6 days. Bone turnover was assessed at baseline and after 3 and 6 days of treatment using two markers of bone formation [osteocalcin (OC) and type I procollagen carboxyl-terminal propeptide (PICP)] and three specific markers of bone resorption [pyridinoline (PYRX), deoxypyridinoline (DPYRX), and N-telopeptide (NTX)]. Serum OC was reduced significantly (P < 0.001) in women with AN compared to normal premenopausal women (5.4 +/- 3.8 vs. 8.6 +/- 4.5 ng/mL) and correlated with percent fat mass (r = 0.60;P < 0.01) and body mass index (r = 0.50;P < 0.05). Markers of bone resorption were elevated significantly compared to normal levels [DPYRX, 18.2 +/- 7.0 vs. 11.4 +/- 5.2 nmol/mmol creatinine, (P < 0.001); NTX, 53.5 +/- 22.5 vs. 36.5 +/- 14.6 nmol BCE/mmol creatinine (P < 0.01)]. IGF-I levels were relatively low at baseline compared to those in age-matched controls (203 +/- 93 vs. 262 +/- 84 ng/mL;P < 0.01) and increased to 673 +/- 268 ng/mL [P < 0.05; 100 micrograms/kg twice daily (BID)] and 545 +/- 255 ng/mL (P < 0.05; 30 micrograms/kg BID). During short term administration of rhIGF-I at a dose of 100 micrograms/kg BID, there was a significant (P < 0.05) increase in markers of bone formation, as assessed by both PICP (147 +/- 33 to 303 +/- 187 ng/mL) and OC (5.3 +/- 3.8 to 10.9 +/- 7.4 ng/mL). There was also a significant (P < 0.05) increase in markers of bone resorption as assessed by PYRX (51.0 +/- 16.6 to 87.1 +/- 8.2 nmol/mmol creatinine) and DPYRX (17.3 +/- 4.5 to 26.3 +/- 3.7 nmol/mmol creatinine). The group randomized to receive short term administration of rhIGF-I at a dose of 30 micrograms/kg BID demonstrated a significant (P < 0.05) increase in PICP (110.9 +/- 47.0 to 134.8 +/- 43.2 ng/mL) and an insignificant increase in OC levels (4.5 +/- 3.2 to 6.8 +/- 5.9 ng/mL). However, markers of bone resorption were unchanged during rhIGF-I administration at this dose. Serum PTH and serum and urinary calcium were unchanged in both treatment groups compared to placebo levels. These data demonstrate that young women with anorexia nervosa have decreased markers of bone formation and increased bone resorption. This is the first demonstration that short term rhIGF-I administration increases markers of bone turnover in severely osteopenic women with AN. The effects of short term rhIGF-I on bone turnover are dose dependent. At a dose of 100 micrograms BID, rhIGF-I administration significantly stimulated both markers of bone formation and bone resorption. At a dose of rhIGF-I of 30 micrograms BID, there was an increase in one marker of bone formation, PICP, without a change in markers of bone resorption. Further studies are required to determine whether chronic administration of rhIGF-I can affect bone mass in young women with profound osteopenia due to anorexia nervosa.

Serum leptin levels in women with anorexia nervosa

Leptin is a protein encoded by the ob gene that is expressed in adipocytes and regulates eating behavior via central neuroendocrine mechanisms. Serum leptin levels have been shown to correlate with weight and percent body fat in normal and obese individuals; however, it is not known whether the regulation of leptin is normal below a critical threshold of body fat in chronic undernutrition. We investigated serum leptin levels in 22 women, aged 23 +/- 4 yr, with anorexia nervosa. Duration of disease, weight, BMI, percent body fat, and serum leptin levels were determined for each patient. Nutritional status was assessed further by caloric intake and measurement of insulin and insulin-like growth factor I (IGF-I) levels. Twenty-three healthy women, aged 23 +/- 4 yr, taking no medications, with normal menstrual function and body mass index (BMI) between 20-26 kg/m2 (mean, 23.7 +/- 1.7 kg/m2), served as a control population for comparison of leptin levels. Subjects with anorexia nervosa were low weight (BMI, 16.3 +/- 1.6 kg/m2; normal, 20-26 kg/m2) and exhibited a striking reduction in percent body fat (7 +/- 2%; normal, 20-30%). The mean serum leptin level was significantly decreased in subjects with anorexia nervosa compared with that in age- and sex-matched controls of normal body weight (5.6 +/- 3.7 vs. 19.1 +/- 8.1 ng/mL; P < 0.0001). Serum leptin levels were correlated highly with weight, as expressed either BMI (r = 0.66; P = 0.002) or percent ideal body weight (r = 0.68; P = 0.0005), body fat (r = 0.70; P = 0.0003), and IGF-I (r = 0.64; P = 0.001), but not with caloric intake or serum levels of estradiol or insulin in subjects with anorexia nervosa. The correlation between leptin and body fat was linear, with progressively lower, but detectable, leptin levels measured even in patients with less than 5% body fat, but was not significant when the effects of weight were taken into account. In contrast, the correlation between leptin and IGF-I remained significant when the effects of weight, body fat, and caloric intake were taken into account. In normal controls, leptin correlated with BMI (r = 0.55; P = 0.007) and IGF-I (r = 0.44; P < 0.05), but not with fat mass. These data demonstrate that serum leptin levels are reduced in association with low weight and percent body fat in subjects with anorexia nervosa compared to normal controls. Leptin levels correlate highly with weight, percent body fat, and IGF-I in subjects with anorexia nervosa, suggesting that the physiological regulation of leptin is maintained in relation to nutritional status even at an extreme of low weight and body fat.

Transforming growth factor beta 1 expression in human colorectal tumours: an independent prognostic marker in a subgroup of poor prognosis patients

Members of the transforming growth factor beta (TGF-beta family, in particular TGF-beta 1, are some of the most potent inhibitory growth factors in a variety of cell types. Resistance to TGF-beta 1-induced growth inhibition is frequently observed in colorectal carcinomas and is associated with tumour progression. Perturbations of TGF-beta 1 expression and function, therefore, may contribute to the loss of some constraints on tumour cell growth. In this study we have examined the expression of TGF-beta 1 and its precursor latency-associated peptide (LAP)-TGF-beta in human colorectal tumours using immunohistochemical techniques. In 86% of the tumours the LAP-TGF-beta complex was present in both the stromal and epithelial cells, whereas the mature TGF-beta 1 peptide was expressed in the glandular epithelium of 58.3% of these tumours. Intense staining for TGF-beta 1 was positively associated with advanced Dukes' stage. Furthermore, there was a significant correlation between the presence of TGF-beta 1 in the tumours and a shorter post-operative survival. This was most significant in a subgroup of patients who had received only a palliative operation. These results suggest that TGF-beta 1 expression may be useful as an independent prognostic indicator for a subgroup of patients who have a particularly poor prognosis.

Pharmacokinetics, pharmacological and anti-tumour effects of the specific anti-oestrogen ICI 182780 in women with advanced breast cancer

We have assessed the pharmacokinetics, pharmacological and anti-tumour effects of the specific steroidal anti-oestrogen ICI 182780 in 19 patients with advanced breast cancer resistant to tamoxifen. The agent was administered as a monthly depot intramuscular injection. Peak levels of ICI 182780 occurred a median of 8-9 days after dosing and then declined but were above the projected therapeutic threshold at day 28. Cmax during the first month was 10.5 ng/ml-1 and during the sixth month was 12.6 ng ml-1. The AUCs were 140.5 and 206.8 ng day ml-1 on the first and sixth month of dosing respectively, suggesting some drug accumulation. Luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels rose after withdrawal of tamoxifen and then plateaued, suggesting no effect of ICI 182780 on the pituitary-hypothalamic axis. There were no significant changes in serum levels of prolactin, sex hormone-binding globulin (SHBG) or lipids. Side-effects were infrequent. Hot-flushes and sweats were not induced and there was no apparent effect of treatment upon the endometrium or vagina. Thirteen (69%) patients responded (seven had partial responses and six showed "no change' responses) to ICI 182780, after progression on tamoxifen, for a median duration of 25 months. Thus ICI 182780, given by monthly depot injection, and at the drug levels described, is an active second-line anti-oestrogen without apparent negative effects on the liver, brain or genital tract and warrants further evaluation in patients with advanced breast cancer.

Spatial Response of Mammals to Late Quaternary Environmental Fluctuations

Analyses of fossil mammal faunas from 2945 localities in the United States demonstrate that the geographic ranges of individual species shifted at different times, in different directions, and at different rates in response to late Quaternary environmental fluctuations. The geographic pattern of faunal provinces was similar for the late Pleistocene and late Holocene, but differing environmental gradients resulted in dissimilar species composition for these biogeographic regions. Modern community patterns emerged only in the last few thousand years, and many late Pleistocene communities do not have modern analogs. Faunal heterogeneity was greater in the late Pleistocene.

5-HT3 receptor antagonists in the control of cisplatin-induced delayed emesis

Two large randomized, double-blind, placebo-controlled studies with an appropriate study design have been conducted to fully evaluate the efficacy of ondansetron in the control of cisplatin-induced delayed emesis. These studies show that ondansetron and particularly ondansetron plus dexamethasone have moderate efficacy in the control of cisplatin-induced delayed emesis and nausea. The benefit of ondansetron, with or without dexamethasone, may be greatest in patients with incomplete control of acute emesis. The efficacy of ondansetron in this setting compared to its greater efficacy during the acute phase of emesis induced by cisplatin and the more prolonged phases of acute emesis induced by cyclophosphamide and carboplatin indicates that non-5-HT3-mediated emetic mechanisms maybe are relatively more important in the delayed phase of emesis following cisplatin.

Evaluation of live attenuated influenza vaccines in children 6-18 months of age: safety, immunogenicity, and efficacy. National Institute of Allergy and Infectious Diseases, Vaccine and Treatment Evaluation Program and the Wyeth-Ayerst ca Influenza Vaccine Investigators Group

Live attenuated, cold-adapted (ca) monovalent and bivalent influenza A vaccines were evaluated in seronegative infants (ages 6-18 months) in a double-blind placebo-controlled trial to assess safety and immunogenicity. A total of 182 seronegative subjects received a single intranasal dose (10(6.2) TCID50) of ca A/Kawasaki/9/86 (H1N1) or ca A/Los Angeles/2/87 (H3N2), both as a bivalent vaccine, or placebo. Respiratory and systemic symptoms did not differ between groups after vaccination. Hemagglutination antibody seroconversions (> or = 1:8) to H3N2 exceeded 90%. In contrast, seroconversions to A/Kawasaki/9/86 (H1N1) were significantly less frequent in bivalent ca vaccine recipients (31%) than in monovalent ca H1N1 recipients (83%) (P < .002). During a subsequent H3N2 epidemic, nasal washes were cultured for viruses from any subject with respiratory illness. H3N2 infections documented by virus isolation were reduced by 65% in ca H3N2 recipients compared with placebo or ca HIM recipients (P = .01).

The Seismic Structure of the Sun

Global Oscillation Network Group data reveal that the internal structure of the sun can be well represented by a calibrated standard model. However, immediately beneath the convection zone and at the edge of the energy-generating core, the sound-speed variation is somewhat smoother in the sun than it is in the model. This could be a consequence of chemical inhomogeneity that is too severe in the model, perhaps owing to inaccurate modeling of gravitational settling or to neglected macroscopic motion that may be present in the sun. Accurate knowledge of the sun's structure enables inferences to be made about the physics that controls the sun; for example, through the opacity, the equation of state, or wave motion. Those inferences can then be used elsewhere in astrophysics.

Evidence of reciprocity of bcl-2 and p53 expression in human colorectal adenomas and carcinomas

Evidence of accumulating for the failure of apoptosis as an important factor in the evolution of colorectal cancer and its poor response to adjuvant therapy. The proto-oncogene bcl-2 suppresses apoptosis. Its expression could provide an important survival advantage permitting the development of colorectal cancer. The expression of bcl-2 and p53 was determined by immunohistochemistry in 47 samples of histologically normal colonic mucosa, 19 adenomas and 53 adenocarcinomas. Expression of bcl-2 in colonic crypts > 5 cm from the tumours was confined to crypt bases but was more extensive and intense in normal crypts < 5 mm from cancers. A higher proportion of adenomas (63.2%) than carcinomas (36.5%) expressed bcl-2 (P < 0.05). A lower proportion of adenomas (31.6%) than carcinomas (62.3%) expressed p53 (P < 0.02). A total of 26.3% of adenomas and 22% of carcinomas expressed both bcl-2 and p53. To determine whether these samples contained cells which expressed both proteins, a dual staining technique for bcl-2 and p53 was used. Only 1/19 adenomas and 2/53 carcinomas contained cells immunopositive for both bcl-2 and p53. Moreover there was evidence of reciprocity of expression of bcl-2 and p53 in these three double staining neoplasms. We suggest that bcl-2 provides a survival advantage in the proliferative compartment of normal crypts and colorectal neoplasms. However, its expression is lost during the evolution from adenoma to carcinoma, whereas p53 expression is increased, an event generally coincident with the expression of stabilised p53, which we presume to represent the mutant form.

New endocrine therapies for breast cancer

How do the new endocrine therapies stand up to the aims of modern endocrine therapy outlined in Table 1? We wish to see increased efficacy, decreased toxicity and improved general health in women taking a new agent. None of the new non-steroidal anti-oestrogens have shown unequivocal evidence of improved efficacy in the clinic to mirror their improved profiles over tamoxifen in preclinical studies. We know that toremifene is equivalent to tamoxifen, but we do not have any phase III data from the other four compounds in development. The specific steroidal antioestrogen, ICI 182,780, looks very promising, but is early in its developmental programme. The new aromatase inhibitors are likely to prove equal to tamoxifen or progestagens, but it is disappointing that improved oestrogen suppression has not led, to date, to improved efficacy. No comment can be made about adjuvant or preventative therapy for any of the new agents, although trials are planned for the new aromatase inhibitors in this clinical situation. Currently, the antiprogestins are disappointing and we will need to wait a considerable time for new agents in preclinical testing to reach the clinic. Many of the new agents are associated with decreased toxicity. It is likely that the NSAEs will be equitoxic with tamoxifen. The steroidal antioestrogen looks particularly non-toxic as do the new aromatase inhibitors, and thus we have an advance in terms of reduced toxicity. The effects of the new agents on the uterus, lipids and bone are in the early stages of testing. Raloxifene, ICI 182,780 and the new aromatase inhibitors are expected to have no proliferative effects on the endometrium, but only the new NSAEs are expected to have beneficial cardiovascular and skeletal effects. If the steroidal anti-oestrogens and new aromatase inhibitors become adjuvant therapies of choice, other agents to prevent osteoporosis and cardiovascular events may also have to be administered.

Effects of short-term antiestrogen treatment of primary breast cancer on estrogen receptor mRNA and protein expression and on estrogen-regulated genes

Effects of the pure antiestrogen ICI182780 and tamoxifen on ER-protein, ER-mRNA, and estrogen-regulated mRNA expression were analysed using matched pretreatment core-cut biopsies and post-treatment mastectomy samples from 43 ER positive human breast cancers. Sixteen controls received either no preoperative treatment (n = 9) (7 days) or placebo (n = 7) (median 21 days) prior to primary surgery. Nineteen patients received ICI182780 6 mg/day (n = 10) or 18 mg/day (n = 9) for 7 days. Eight patients were given preoperative tamoxifen (4 x 40 mg-day 1, 20 mg/day thereafter, median 21 days). ER-protein expression was assessed on pre and post treatment samples by immunocytochemistry. ER, pS2, pLIV1, and actin-mRNA expression was determined by northern analysis on post-treatment samples only. ER-mRNA levels were similar to controls following ICI182780 or tamoxifen treatment. However ER-protein levels were significantly suppressed by ICI182780, particularly at the higher dosage (p = 0.0013). Tamoxifen had no significant effect on ER-protein levels. The ER-mRNA and ER-protein contents of control tumors were linearly related (Spearman r = 0.719, p = 0.006). A similar relationship between pretreatment protein and post ICI182780 treatment mRNA levels was observed (r = 0.652, p = 0.005). However, comparison of post ICI182780 treatment protein and mRNA results shows a loss of linearity through a reduction in protein without concurrent loss of mRNA (r = 0.28, p = 0.257). pS2 mRNA hybridization was lower in ICI182780 treated samples than controls (Mann-Whitney p = 0.035) but was unaffected by tamoxifen. pLIV1 mRNA hybridization was uninfluenced by either treatment. Short term exposure of breast tumors to ICI182780 appears to produce a greater inhibition of estrogen-induced transcriptional events than tamoxifen. These effects appear to occur without a concurrent reduction in ER mRNA levels.

Buoyant density of Escherichia coli is determined solely by the osmolarity of the culture medium

In previous studies, we had shown that the buoyant density of Escherichia coli is determined by the osmolarity of the growth medium by varying the osmolarity of the medium with NaCl or sucrose. However, the buoyant density of the cells always exceeded that of the growth medium. Here we determined the effect of medium with a buoyant density greater than the expected buoyant density of cells by adding Nycodenz to Luria broth. Percoll gradients of cells were analyzed by laser light scattering. The buoyant density for 125- and 375-mOsM-grown cells was 0.002 g/ml and 0.003 g/ml more, respectively, for cells grown in the presence of Nycodenz than those grown without Nycodenz, while the buoyant density of 250-mOsM-grown cells was 0.005 g/ml less for cells grown in the presence of Nycodenz than those grown without Nycodenz. Cells grown in 500-mOsM medium with or without Nycodenz had the same buoyant density. The buoyant density of cultures grown in defined medium was the same as those grown in rich medium, with only the medium osmolarity correlating to buoyant density. We conclude from these experiments that neither buoyant density nor chemical make-up of the medium determines the buoyant density of cells grown in that medium. Only the medium osmolarity determines cell buoyant density, suggesting that E. coli has no mechanisms to sense buoyant density.

The role of attention in the programming of saccades

Accurate saccadic programming in natural visual scenes requires a signal designating which of the many potential targets is to be the goal of the saccade. Is this signal controlled by the allocation of perceptual attention, or do saccades have their own independent selective filter? We found evidence for the involvement of perceptual attention, namely: (1) summoning perceptual attention to a target also facilitated saccades; (2) perceptual identification was better at the saccadic goal than elsewhere; and (3) attempts to dissociate the locus of attention from the saccadic goal were unsuccessful, i.e. it was not possible to prepare to look quickly and accurately at one target while at the same time making highly accurate perceptual judgements about targets elsewhere. We also studied the trade-off between saccadic and perceptual performance by means of a novel application of the "attentional operating characteristic" (AOC) to oculomotor performance. This analysis revealed that some attention could be diverted from the saccadic goal with virtually no cost to either saccadic latency or accuracy, showing that there is a ceiling on the attentional demands of saccades. The links we discovered between saccades and attention can be explained by a model in which perceptual attention determines the endpoint of the saccade, while a separate trigger signal initiates the saccade in response to transient changes in the attentional locus. The model will be discussed in the context of current neurophysiological work on saccadic control.