Colostrogenesis: candidate genes for IgG1 transcytosis mechanisms in primary bovine mammary epithelial cells.

Bovine colostrogenesis is distinguished by the specific transfer of IgG1 from the blood to mammary secretions. The process has been shown to be initiated by hormones and occurs during the last weeks of pregnancy when steroid concentrations of estradiol (E2 ) and progesterone (P4 ) are highly elevated. Rodent intestinal uptake of immunoglobulin G is mediated by a receptor termed Fc fragment of IgG, Receptor, Transporter, alpha (FcGRT) and supported by light chain Beta-2-Microglobulin (β2M). We hypothesized that steroid hormone treatments (E2 and P4 ) of bovine mammary epithelial cells in vitro would induce up-regulation of IgG1 transcytosis candidate gene mRNA expression suggesting involvement in IgG1 transcytosis. Two different primary bovine mammary epithelial cell cultures were cultured on plastic and rat tail collagen and treated with hormonal combinations (steroids/lactogenic hormones). Evaluated mRNA components were bLactoferrin (bLf: a control), bFcGRT, β2M, and various small GTPases; the latter components are reported to direct endosomal movements in eukaryotic cells. All tested transcytosis components showed strong expression of mRNA in the cells. Expression of bFcGRT, bRab25 and bRhoB were significantly up-regulated (p < 0.05) by steroid hormones. bRab25 and bRhoB showed increased expression by steroid treatments, but also with lactogenic hormones. Analysis for the oestrogen receptor (ER) mRNA was mostly negative, but 25% of the cultures tested exhibited weak expression, while the progesterone receptor (PR) mRNA was always detected. bRab25 and bRhoB and likely bFcGRT are potential candidate genes for IgG1 transcytosis in bovine mammary cells.

Venous thrombo-embolism as a complication of cross-sex hormone treatment of male-to-female transsexual subjects: a review

Administration of cross-sex hormones to male-to-female transsexual subjects, usually oestrogens + often anti-androgens, such as cyproterone acetate, carries a risk of venous thromboembolism (VTE). VTE usually occurs in the first year of oestrogen administration. Ethinyl oestradiol, due to its chemical structure, was in 2003 identified as a major factor in the occurrence of VTE. Most clinics do not prescribe ethinyl oestradiol any longer, but people who take hormones without medical supervision use often oral contraceptives containing ethinyl oestradiol, many times in overdose. Cessation of use of ethinyl oestradiol and peri-operative thrombosis prophylaxis for surgery have reduced prevalence rate of VTE. Other oral oestrogens should not be overdosed, and transdermal oestrogen is to be preferred. Thrombosis prophylaxis for surgery is mandatory. It seems advisable to stop hormone use at least 2 weeks before major surgery, to be resumed only after 3 weeks following full mobilisation.

Osseointegration of biochemically modified implants in an osteoporosis rodent model

The present study examined the impact of implant surface modifications on osseointegration in an osteoporotic rodent model. Sandblasted, acid-etched titanium implants were either used directly (control) or were further modified by surface conditioning with NaOH or by coating with one of the following active agents: collagen/chondroitin sulphate, simvastatin, or zoledronic acid. Control and modified implants were inserted into the proximal tibia of aged ovariectomised (OVX) osteoporotic rats (n = 32/group). In addition, aged oestrogen competent animals received either control or NaOH conditioned implants. Animals were sacrificed 2 and 4 weeks post-implantation. The excised tibiae were utilised for biomechanical and morphometric readouts (n = 8/group/readout). Biomechanical testing revealed at both time points dramatically reduced osseointegration in the tibia of oestrogen deprived osteoporotic animals compared to intact controls irrespective of NaOH exposure. Consistently, histomorphometric and microCT analyses demonstrated diminished bone-implant contact (BIC), peri-implant bone area (BA), bone volume/tissue volume (BV/TV) and bone-mineral density (BMD) in OVX animals. Surface coating with collagen/chondroitin sulphate had no detectable impact on osseointegration. Interestingly, statin coating resulted in a transient increase in BIC 2 weeks post-implantation; which, however, did not correspond to improvement of biomechanical readouts. Local exposure to zoledronic acid increased BIC, BA, BV/TV and BMD at 4 weeks. Yet this translated only into a non-significant improvement of biomechanical properties. In conclusion, this study presents a rodent model mimicking severely osteoporotic bone. Contrary to the other bioactive agents, locally released zoledronic acid had a positive impact on osseointegration albeit to a lesser extent than reported in less challenging models.

Cryopreservation and transplantation of ovarian tissue exclusively to postpone menopause: technically possible but endocrinologically doubtful.

Transplantation of cryopreserved ovarian tissue has been shown to induce pregnancies and puberty successfully. Therefore, using cryopreserved ovarian tissue to postpone menopause (tissue hormone therapy [THT]) seems to be an interesting option to avoid conventional menopause hormone therapy (MHT). Pregnancy induction and replacing MHT by THT, however, are completely different topics as different requirements need to be met. First, MHT requires long-lasting and continuous hormone production. It still needs to be proven if the transplanted tissue is active for at least 5 years with a continuous follicle growth to avoid phases with low oestrogen production, which would otherwise cause menopausal symptoms and could reduce the postulated benefit for women's health. Second, the advantage of a physiological hormone production over a non-physiological MHT is still hypothetical. Third, women who have undergone hysterectomies who do not need progesterone for endometrial protection would only require oestrogens, imposing more health benefits (cardiovascular system, mammary gland) than oestrogen and progesterone production or replacement. Therefore, transplanting ovarian tissue exclusively to postpone menopause is endocrinologically doubtful and should only be carried out within clinical trials.

Fertility preservation options in breast cancer patients.

The purpose of this review is to analyse current options for fertility preservation in young women with breast cancer (BC). Considering an increasing number of BC survivors, owing to improvements in cancer treatment and delaying of childbearing, fertility preservation appears to be an important issue. Current fertility preservation options in BC survivors range from well-established standard techniques to experimental or investigational interventions. Among the standard options, random-start ovarian stimulation protocol represents a new technique, which significantly decreases the total time of the in vitro fertilisation cycle. However, in patients with oestrogen-sensitive tumours, stimulation protocols using aromatase inhibitors are currently preferred over tamoxifen regimens. Cryopreservation of embryos and oocytes are nowadays deemed the most successful techniques for fertility preservation in BC patients. GnRH agonists during chemotherapy represent an experimental method for fertility preservation due to conflicting long-term outcome results regarding its safety and efficacy. Cryopreservation of ovarian tissue, in vitro maturation of immature oocytes and other strategies are considered experimental and should only be offered within the context of a clinical trial. An early pretreatment referral to reproductive endocrinologists and oncologists should be suggested to young BC women at risk of infertility, concerning the risks and benefits of fertility preservation options.

Interactions métaboliques entre le bisphénol A et le naproxène dans un modèle de foie de rat isolé et perfusé

L'exposition aux mélanges de contaminants (environnementaux, alimentaires ou thérapeutiques) soulève de nombreuses interrogations et inquiétudes vis-à-vis des probabilités d'interactions toxicocinétiques et toxicodynamiques. Une telle coexposition peut influencer le mode d’action des composants du cocktail et donc de leur toxicité, suite à un accroissement de leurs concentrations internes. Le bisphénol A (4 dihydroxy-2,2-diphenylpropane) est un contaminant chimique répandu de manière ubiquitaire dans notre environnement, largement utilisé dans la fabrication des plastiques avec l’un des plus grands volumes de production à l’échelle mondiale. Il est un perturbateur endocrinien par excellence de type œstrogèno-mimétique. Cette molécule est biotransformée en métabolites non toxiques par un processus de glucuronidation. L'exposition concomitante à plusieurs xénobiotiques peut induire à la baisse le taux de glucuronidation du polluant chimique d'intérêt, entre autres la co-exposition avec des médicaments. Puisque la consommation de produits thérapeutiques est un phénomène grandissant dans la population, la possibilité d’une exposition simultanée est d’autant plus grande et forte. Sachant que l'inhibition métabolique est le mécanisme d'interaction le plus plausible pouvant aboutir à une hausse des niveaux internes ainsi qu’à une modulation de la toxicité prévue, la présente étude visait d'abord à confirmer et caractériser ce type d'interactions métaboliques entre le bisphénol A et le naproxène, qui est un anti-inflammatoire non stéroïdiennes (AINS), sur l'ensemble d'un organe intact en utilisant le système de foie de rat isolé et perfusé (IPRL). Elle visait ensuite à déterminer la cinétique enzymatique de chacune de ces deux substances, seule puis en mélange binaire. Dans un second temps, nous avons évalué aussi l’influence de la présence d'albumine sur la cinétique métabolique et le comportement de ces deux substances étudiées en suivant le même modèle de perfusion in vivo au niveau du foie de rat. Les constantes métaboliques ont été déterminées par régression non linéaire. Les métabolismes du BPA et du NAP seuls ont montré une cinétique saturable avec une vélocité maximale (Vmax) de 8.9 nmol/min/ mg prot de foie et une constante d'affinité de l'enzyme pour le substrat (Km) de 51.6 μM pour le BPA et de 3 nmol/min/mg prot de foie et 149.2 μM pour le NAP. L'analyse des expositions combinées suggère une inhibition compétitive partielle du métabolisme du BPA par le NAP avec une valeur de Ki estimée à 0.3542 μM. Les résultats obtenus montrent que l’analyse de risque pour les polluants environnementaux doit donc prendre en considération la consommation des produits pharmaceutiques comme facteur pouvant accroitre le niveau interne lors d’une exposition donnée. Ces données in vivo sur les interactions métaboliques pourraient être intégrées dans un modèle pharmacocinétique à base physiologique (PBPK) pour prédire les conséquences toxicococinétique (TK) de l'exposition d'un individu à ces mélanges chimiques.

Interactions métaboliques entre le bisphénol A et le naproxène dans un modèle de foie de rat isolé et perfusé

L'exposition aux mélanges de contaminants (environnementaux, alimentaires ou thérapeutiques) soulève de nombreuses interrogations et inquiétudes vis-à-vis des probabilités d'interactions toxicocinétiques et toxicodynamiques. Une telle coexposition peut influencer le mode d’action des composants du cocktail et donc de leur toxicité, suite à un accroissement de leurs concentrations internes. Le bisphénol A (4 dihydroxy-2,2-diphenylpropane) est un contaminant chimique répandu de manière ubiquitaire dans notre environnement, largement utilisé dans la fabrication des plastiques avec l’un des plus grands volumes de production à l’échelle mondiale. Il est un perturbateur endocrinien par excellence de type œstrogèno-mimétique. Cette molécule est biotransformée en métabolites non toxiques par un processus de glucuronidation. L'exposition concomitante à plusieurs xénobiotiques peut induire à la baisse le taux de glucuronidation du polluant chimique d'intérêt, entre autres la co-exposition avec des médicaments. Puisque la consommation de produits thérapeutiques est un phénomène grandissant dans la population, la possibilité d’une exposition simultanée est d’autant plus grande et forte. Sachant que l'inhibition métabolique est le mécanisme d'interaction le plus plausible pouvant aboutir à une hausse des niveaux internes ainsi qu’à une modulation de la toxicité prévue, la présente étude visait d'abord à confirmer et caractériser ce type d'interactions métaboliques entre le bisphénol A et le naproxène, qui est un anti-inflammatoire non stéroïdiennes (AINS), sur l'ensemble d'un organe intact en utilisant le système de foie de rat isolé et perfusé (IPRL). Elle visait ensuite à déterminer la cinétique enzymatique de chacune de ces deux substances, seule puis en mélange binaire. Dans un second temps, nous avons évalué aussi l’influence de la présence d'albumine sur la cinétique métabolique et le comportement de ces deux substances étudiées en suivant le même modèle de perfusion in vivo au niveau du foie de rat. Les constantes métaboliques ont été déterminées par régression non linéaire. Les métabolismes du BPA et du NAP seuls ont montré une cinétique saturable avec une vélocité maximale (Vmax) de 8.9 nmol/min/ mg prot de foie et une constante d'affinité de l'enzyme pour le substrat (Km) de 51.6 μM pour le BPA et de 3 nmol/min/mg prot de foie et 149.2 μM pour le NAP. L'analyse des expositions combinées suggère une inhibition compétitive partielle du métabolisme du BPA par le NAP avec une valeur de Ki estimée à 0.3542 μM. Les résultats obtenus montrent que l’analyse de risque pour les polluants environnementaux doit donc prendre en considération la consommation des produits pharmaceutiques comme facteur pouvant accroitre le niveau interne lors d’une exposition donnée. Ces données in vivo sur les interactions métaboliques pourraient être intégrées dans un modèle pharmacocinétique à base physiologique (PBPK) pour prédire les conséquences toxicococinétique (TK) de l'exposition d'un individu à ces mélanges chimiques.

Molecular evolution of breast cancer

Molecular analysis of invasive breast cancer and its precursors has furthered our understanding of breast cancer progression. In the past few years, new multi-step pathways of breast cancer progression have been delineated through genotypic-phenotypic correlations. Nuclear grade, more than any other pathological feature, is strongly associated with the number and pattern of molecular genetic abnormalities in breast cancer cells. Thus, there are two distinct major pathways to the evolution of low- and high-grade invasive carcinomas: whilst the former consistently show oestrogen receptor (ER) and progesterone receptor (PgR) positivity and 16q loss, the latter are usually ER/PgR-negative and show Her-2 over-expression/amplification and complex karyotypes. The boundaries between the evolutionary pathways of well-differentiated/low-grade ductal and lobular carcinomas have been blurred, with changes in E-cadherin expression being one of the few distinguishing features between the two. In addition, lesions long thought to be precursors of breast carcinomas, such as hyperplasia of usual type, are currently considered mere risk indicators, whilst columnar cell lesions are now implicated as non-obligate precursors of atypical ductal hyperplasia (ADH) and well-differentiated ductal carcinoma in situ (DCIS). However, only through the combination of comprehensive morphological analysis and cutting-edge molecular tools can this knowledge be translated into clinical practice and patient management. Copyright (C) 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley Sons, Ltd.

Assessing the effectiveness of a mammography screening service

Background: Trials have shown that mammography screening reduces mortality and probably decreases morbidity related to breast cancer. Methods: We assessed whether the major mammography service in Western Australia (BreastScreen WA) is likely to reduce mortality by comparing prognostic variables between screen-detected and other cases of breast cancer diagnosed in 1999. We assessed likely reductions in morbidity by comparing treatments received by these two groups. To confirm mortality and morbidity reduction, we also compared prognostic variables and treatments with targets. Information on demographic variables, tumour characteristics at presentation and treatments were collected from medical records for all incident cases of breast cancer in Western Australia in 1999. We matched cases with the Western Australian Cancer Registry records to determine which cases had been detected by BreastScreen WA. Results: BreastScreen WA achieved the targets for mortality reduction. Tumours detected by BreastScreen WA were smaller in size, less likely to have vascular invasion, of lower histological grade and were more likely to be ductal carcinoma in situ alone without invasive carcinoma. Oestrogen receptor status was more likely to be positive, the difference in progesterone status was not significant, and lymph node involvement tended to be lower. BreastScreen WA patients were treated more often with local therapy and less often with systemic therapy, and the proportion of patients treated with breast-conserving surgery was close to the target for minimizing morbidity in breast cancer. Conclusion: Mammographic detection of breast cancer by BreastScreen WA is associated with reduced breast cancer morbidity and a more favourable prognosis.

Basal-like breast carcinomas: clinical outcome and response to chemotherapy

Background: Grade-III invasive ductal carcinomas of no special type (IDCs-NST) constitute a heterogeneous group of tumours with different clinical behaviour and response to chemotherapy. As many as 25% of all grade-III IDCs-NST are known to harbour a basal-like phenotype, as defined by gene expression profiling or immunohistochemistry for basal cytokeratins. Patients with basal-like breast carcinomas (BLBC) are reported to have a shorter disease-free and overall survival. Material and methods: A retrospective analysis of 49 patients with BLBC (as defined by basal cytokeratin expression) and 49 controls matched for age, nodal status and grade was carried out. Histological features, immunohistochemical findings for oestrogen receptor (ER), progesterone receptor (PgR) and HER2, and clinical outcome and survival after adjuvant chemotherapy were compared between the two groups. Results: It was more likely for patients with BLBCs to be found negative for ER (p < 0.0001), PgR (p < 0.0001) and HER2 (p < 0.01) than controls. Patients with BLBCs were found to have a significantly higher recurrence rate (p < 0.05) and were associated with significantly shorter disease-free and overall survival (both p, 0.05). In the group of patients who received anthracycline-based adjuvant chemotherapy (BLBC group, n = 47; controls, n = 49), both disease-free and overall survival were found to be significantly shorter in the BLBC group (p < 0.05). Conclusions: BLBCs are a distinct clinical and pathological entity, characterised by high nuclear grade, lack of hormone receptors and HER2 expression and a more aggressive clinical course. Standard adjuvant chemotherapy seems to be less effective in these tumours and new therapeutic approaches are indicated.

Hormones down under: Hormone therapy use after the women's health initiative

Aims: The primary objective was to describe the usage pattern of hormone therapy (HT) in a sample of urban Australian women in 2001 and to assess the characteristics of users vs. non-users. The second objective was to determine whether there had been any change in usage since the publication of the results of the combined oestrogen plus progestagen arm of the Women's Health Initiative (WHI) in 2002. Methods: A cohort of 374 postmenopausal women aged 50-80 years participated in this substudy of the LAW (Longitudinal Assessment of Ageing in Women) project: a 5-year multidisciplinary, observational study. Participants completed an annual medical assessment including details of the use of HT and the reasons for use, as well as demographic and psychosocial data. Results: In December 2001, 30.8% of the participants were using HT, whereas 55.4% were ever users. The management of vasomotor symptoms and mood disturbance were the primary reasons for use. Of those who had been using HT in December 2001 (24.4%) women ceased using HT in the 3 months following publication of the WHI results. The percentage of women using HT in December 2003 (13.9%) was less than half of that of December 2001. Conclusion: The rate of HT use and the reasons for use, in 2001 in Brisbane was similar to that of other Australian regions. Usage of HT decreased since the publication of the WHI results in 2002 which may reflect changing attitudes by patients and practitioners regarding HT.

HRT and everyday memory at menopause: A comparison of two samples of mid-aged women

Research on the effect of hormone replacement therapy (HRT) on memory in mid-aged women is equivocal although findings indicate that oestrogen may enhance verbal memory. Mood may mediate the relationship between HRT and memory. This study examined the effect of HRT on mood and everyday memory in two samples of women between ages 40 and 60 years. In the cross-sectional comparison (N = 124), HRT users performed significantly better on tests of everyday and verbal memory. A within-woman comparison of 17 women showed that everyday memory, working memory, and delayed verbal memory improved after 3 months of HRT use. The improvement in memory was not mediated by mood. These results suggest that any effect of HRT on mood may be short-term but that some aspects of everyday memory are enhanced, particularly verbal memory. The development of the everyday memory construct and future investigation are discussed.

Microarray-based comparative genomic hybridisation of breast cancer patients receiving neoadjuvant chemotherapy

We analysed the molecular genetic profiles of breast cancer samples before and after neoadjuvant chemotherapy with combination doxorubicin and cyclophosphamide (AC). DNA was obtained from microdissected frozen breast core biopsies from 44 patients before chemotherapy. Additional samples were obtained before the second course of chemotherapy (D21) and after the completion of the treatment (surgical specimens) in 17 and 21 patients, respectively. Microarray-based comparative genome hybridisation was performed using a platform containing approx5800 bacterial artificial chromosome clones (genome-wide resolution: 0.9 Mb). Analysis of the 44 pretreatment biopsies revealed that losses of 4p, 4q, 5q, 12q13.11–12q13.12, 17p11.2 and 17q11.2; and gains of 1p, 2p, 7q, 9p, 11q, 19p and 19q were significantly associated with oestrogen receptor negativity. 16q21–q22.1 losses were associated with lobular and 8q24 gains with ductal types. Losses of 5q33.3–q4 and 18p11.31 and gains of 6p25.1–p25.2 and Xp11.4 were associated with HER2 amplification. No correlations between DNA copy number changes and clinical response to AC were found. Microarray-based comparative genome hybridisation analysis of matched pretreatment and D21 biopsies failed to identify statistically significant differences, whereas a comparison between matched pretreatment and surgical samples revealed a statistically significant acquired copy number gain on 11p15.2–11p15.5. The modest chemotherapy-driven genomic changes, despite profound loss of cell numbers, suggest that there is little therapeutic selection of resistant non-modal cell lineages.

The effect of hormone replacement therapy on mood and everyday memory in younger mid-life women

Research on the effect of hormone replacement therapy (HRT) on both mood and memory indicates that oestrogen may enhance verbal memory in younger mid-aged women. This study examined the effect of HRT on everyday memory, while accounting for mood changes, in women between ages 40 and 60. A within-subjects comparison of 17 women, showed that mood, everyday memory, working memory, and delayed verbal memory improved after 3 months of HRT use. The improvement in memory was not mediated by mood, but changes in mood were moderated by exercise habits. The results suggest that verbal memory in particular may be enhanced by HRT in this age group, and everyday memory is an important construct to consider in future research.

Chromogenic in situ hybridisation testing for HER2 gene amplification in breast cancer produces highly reproducible results concordant with fluorescence in situ hybridisation and immunohistochemistry

Aims: The objective of this study was to evaluate the accuracy, ease of use and reproducibility of chromogenic in situ hybridisation (CISH) for HER2 testing by studying its inter-laboratory concordance in five Australian pathology laboratories. Methods: The HER2 status of 49 breast cancers was determined by CISH twice in two different laboratories. Each sample had previously been tested by immunohistochemistry (IHC; 2+ and 3+ cases selected) and fluorescence in situ hybridisation ( FISH). Participating laboratories were blinded to these test results. Oestrogen receptor ( ER) status was also evaluated for each cancer. Results: High correlation was observed between FISH and CISH results. No cases showing high gene amplification by FISH were scored as non-amplified by CISH ( kappa coefficient=1). High correlation was observed between IHC and CISH, all IHC 3+ samples showing amplification by CISH. Inter-laboratory CISH concordance was also good ( kappa coefficient=0.67). Fifty-six per cent of HER2-amplified samples tested ER positive, while 42% of ER-positive cases showed HER2 gene amplification, confirming that HER2 testing should not be confined to ER-negative breast cancers. Conclusions: These findings demonstrate that CISH is a robust test to assess HER2 status in breast cancer and therefore is an important addition to the HER2 testing algorithm.