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Southern blotting of bovine genomic DNA indicated the presence of at least 3 bovine tIFN genes. The full DNA sequence of one of these genes, thought to be expressed in trophoblast, has been determined, including 193 bp of 5' non-coding region. The inferred amino acid sequence of bovine tIFN is more similar to ovine tIFN (80%) than to bovine IFN-alpha II (70%). The 5' flanking sequence has some similarity with bovine IFN-alpha II, and may contain a viral response element. A recombinant bovine alpha I interferon (Ciba Geigy; brIFN), resembling tIFN, extended oestrous cycle length in sheep when administered by intrauterine infusion over the period, Days 12-15 after oestrus, when maternal recognition of pregnancy occurs. Intramuscular injection was only effective at the doses used if given over a longer period (i.e. Days 9-15). Our experiments indicate that both tIFN and brIFN inhibit luteolysis by preventing a rise in endometrial oxytocin receptor concentrations, and suggest that tIFN achieves this by extending the time for which progesterone suppresses oxytocin receptor development. Further studies are required to confirm this hypothesis and to elucidate the interaction of the effects of progesterone and tIFN in endometrial cells.

The entire coding region of an ovine endometrial oxytocin receptor (OTR) cDNA was generated by PCR, subcloned into the SV40 major late promoter expression vector pSVLJ and transiently expressed in Cos-7 cells. A specific OTR antagonist, 125I-labelled d(CH2)5 [Tyr(Me)2,Thr4,Tyr-NH29]-vasotocin (OTA), was used to describe the binding kinetics of the expressed receptor which had a Kd of 4·5 nm and Bmax of 2·4 nm/mg protein (6·8 × 105 receptor molecules/transfected cell). The functional properties of the expressed OTR were determined by measuring oxytocin-induced phosphoinositide (PI) hydrolysis. Oxytocin increased PI turnover in OTR transfected cells fourfold in excess of residual endogenous activity, and stimulated phospholipase C (PLC) activity in a dose- and time-dependent manner, confirming that the expressed OTR cDNA was functional. Arginine vasopressin also stimulated PI turnover in a dose-dependent manner; thresholds of responses to oxytocin and arginine vasopressin were 10−9 m and 10−7 m respectively. OTA did not increase PI turnover and competitively inhibited the oxytocin-induced response. Direct activation of the pathway by aluminium fluoride and guanosine (3′-Othio)-triphosphate (GTPγS) confirmed that the OTR was G-protein linked. Co-incubation of GTPγS with oxytocin shifted the PI-response threshold from 10−7 m to 10−9 m and significantly increased the level of response, suggesting that maximum PI turnover was agonist-dependent. The G-protein involved in mediating the signal transduction pathway was pertussis toxin-insensitive and, therefore, probably a member of the Gq subfamily. The PLC inhibitor, U73122, had no effect on oxytocin-induced PI turnover, consistent with the response in endometrial tissue. These data suggest that the signalling pathway mediated by expressed OTR is similar to that attributed to OTR occupancy in ovine endometrium. Journal of Endocrinology (1996) 149, 389–396

A bovine trophoblast interferon (IFN-τ) gene promoter sequence (− 450 to +26 bp relative to the transcription start site) led to expression of reporter gene (CAT) constructs transfected into L929 (murine fibroblast) or JAR (human choriocarcinoma) cells. Expression depended on the presence of an exogenous (SV40) enhancer. Poly(I)(C) activated endogenous IFN production in L929 and JAR cells but had no consistent effect on CAT expression. Similar results were obtained in L929 cells with inactivated Newcastle disease virus. There was no 'priming' effect of exogenous Type I IFN. Deletion mutants revealed sites exerting negative control on expression between −338 and −247 bp, and between −150 and −71 bp; these regions contained sequences resembling previously identified negative regulatory domains. In the absence of viral inducibility it is proposed that negative regulation contributes towards the stringent control of expression characteristic of IFN-τ genes.

Between January 1980 and October 1983, 417 patients were randomized for mastectomy followed by axillary node sampling or full axillary clearance. The aim of the study was to determine whether a standard ‘four-node’ axillary sample, followed by careful dissection of removed tissue, could accurately indicate the extent of local treatment required. Axillary radiotherapy was given only to patients with histological involvement of sampled nodes and not to any having axillary clearance. The incidence of involved nodes was similar for both groups, as were distant relapse and survival rates. Currently 62.6 per cent are alive after clearance and 65.0 per cent after sampling. A non-significant increase in the rate of locoregional relapse was observed for those treated by axillary node clearance, this being due mainly to increased relapse on the unirradiated chest wall (clearance 21 per cent versus sampling 12 per cent in patients with node-positive disease). There was only a minor difference in axillary relapse, favouring axillary clearance (3.0 versus 5.4 per cent). In patients with operable breast cancer, mastectomy with axillary node sampling gives equal control to mastectomy with axillary node clearance but, as morbidity is greater, surgical clearance of the axilla is the preferred option.

Objective: To determine any cardiac or vascular morbidity associated with long term treatment with tamoxifen given after mastectomy for primary breast cancer. Design: Cohort study using linkage between database of a randomised trial and statistics of Scottish hospital inpatients to identify episodes of cardiac and vascular morbidity. Setting: NHS hospitals in Scotland. Subjects: 1312 women who had undergone mastectomy for breast cancer and who were randomised either to a treatment group to receive adjuvant tamoxifen or to a control group to be given tamoxifen only on first relapse of disease. Maximum duration of tamoxifen treatment was 14 years. Total woman years of follow up were 9943. Main outcome measures: Randomised and observational comparisons of risk (expressed as hazard ratios) of myocardial infarction, other cardiac event, cerebrovascular disease, or thromboembolic event according to treatment allocated and between non-users, former users, and current users of tamoxifen. Results: Use of tamoxifen was associated with lower rates of myocardial infarction. Hazard ratio for women in control group was 1.92 (95% confidence interval 0.99 to 3.73) compared with women allocated to adjuvant treatment. The association was stronger for current use: hazard ratio for non-users was 3.49 (1.52 to 8.03) compared with current users. Current users of tamoxifen, however, had higher rates of thromboembolic events: hazard ratio for non-users was 0.40 (0.18 to 0.90) compared with current users. Conclusions: Our results provide further evidence that tamoxifen reduces the risk of myocardial infarction. Thromboembolic events should be carefully monitored in trials of tamoxifen, particularly those of prophylactic treatment, in which tamoxifen is given to healthy women.

A sheep endometrial oxytocin receptor (OTR) cDNA (1·5 kb) was isolated from a λ-ZAP library using a reverse transcription-PCR product probe generated from oestrous endometrial mRNA. The sheep OTR cDNA shared an overall similarity of 82% with human OTR cDNA, 85% with pig OTR cDNA and 76% with rat OTR cDNA. The encoded receptor was a 391 amino acid polypeptide 94% similar to human OTR, 94% similar to pig OTR and 93% similar to rat OTR. The sheep OTR contained two additional amino acids compared with human OTR which were located in the highly GC-rich third intracytoplasmic loop. This region is thought to be associated with G protein coupling and signal transduction. Expression of the cDNA in Cos-7 cells and measurement of oxytocin-induced phosphoinositide turnover confirmed that it coded for a functional product. The affinity of the expressed receptor was comparable with that observed for the in vivo receptor.

From 1963–1973, 200 women with operable breast cancer were randomized in a trial comparing two local therapy policies: 97 to the ‘radical’ policy (radical mastectomy) and 103 to the ‘conservative’ (total mastectomy and axillary node sample). The extent of local therapy also varied with axillary node histology: if node negative or no node identified — no radiotherapy (XRT) and, if node positive, radiotherapy to the chest wall and regional lymph nodes in the radical group and to the axilla alone in the conservative group. There were no differences overall either in total survival (log rank test P = 0.23) or in distant disease-free rates ( P = 0.092). The risk of loco-regional relapse favoured those radically treated ( P = 0.047). 71 patients were found to have involved nodes (4 XRT violations). Following an axillary clearance 60 were node negative and 3 had no nodes identified whilst following an axillary sample 37 were node negative and 29 had no nodes identified ( 3 29 XRT violations). Excluding the XRT violations, the distant disease free rates for these three groups were 64%, 36% and 57% and the axillary relapse rates were 1.5%, 1.6% and 16% respectively. It is concluded that the node sampling was insufficient to identify the node positive cases to the detriment of the assessment of the conservative policy.

Between April 1974 and December 1979, 348 women, with Stage I or II breast cancer without node involvement on lymph node sampling, were randomized, after simple mastectomy, for routine postoperative radiotherapy or no further treatment in a trial conducted in the South-east of Scotland. After a median follow-up of 15 years from randomization for the alive patients, the two treatment groups had very similar results for both distant disease-free rates and total survival. A non-significant advantage in event-free survival was found for those irradiated (HR = 1.21, CI = 0.91–1.61) which was accounted for by a significant increase in loco-regional relapse in those not given radiotherapy (HR = 2.19, CI = 1.38–3.48). In one-third of those randomized, no information on node histology was available. Subgroup analysis within the resulting two categories of nodal status confirmed an advantage in distant disease-free rates for those classified histologically as node negative compared to those without node histology (HR = 0.54, CI = 0.38–0.77). It is concluded that, for women with stage I or II breast cancer, when histological examination of lower axillary nodes suggests absence of axillary spread, a watching policy is safe but that when no nodes have been examined, postoperative radiotherapy should be considered in order to achieve maximal local control of disease.

A synthetic 45-mer oligonucleotide corresponding to part of the ovine endometrial oxytocin receptor cDNA was hybridized to sections of ovine uterus collected from 40 ewes at different stages during the oestrous cycle, the first 3 weeks of pregnancy and seasonal anoestrus. The quantity of oxytocin receptor mRNA was measured as the optical density (OD) value on autoradiographs using image analysis. Message first appeared in the luminal epithelium on days 14–15 of the cycle, increasing to a peak OD of 0·48 at oestrus and decreasing again between days 2 and 5. Oxytocin receptor mRNA in the superficial glands, deep glands and caruncular stroma increased between day 15 and oestrus to peak OD values of 0·17, 0·11 and 0·11 respectively, declining again by day 2 and reaching basal values (ODs.e.m.) on days 0–1, but the change was not significant. In pregnant ewes there was no detectable oxytocin receptor mRNA on days 14–15 in any region, but hybridization to the luminal epithelium was present in two of three ewes on day 21. In anoestrous ewes oxytocin receptor mRNA concentrations in all areas of the endometrium were approximately half those measured at oestrus. Optical density readings for oxytocin receptor mRNA in the various uterine compartments were compared with measurements of oxytocin receptors in the same regions as assessed by binding studies using the 125I-labelled oxytocin antagonist d(CH2)5[Tyr(Me)2,Thr4,Tyr-NH29]-vasotocin (125I-labelled OTA). In the endometrium, receptor mRNA and 125I-labelled OTA binding patterns changed in parallel, and both sets of measurements were significantly correlated (P125I-labelled OTA binding occurred at oestrus; this was not accompanied by a similar increase in oxytocin receptor mRNA hybridization. This study helps to confirm that the previously identified cDNA clone is derived from the ovine oxytocin receptor, as patterns of oxytocin receptor mRNA expression in the endometrium closely resembled those of oxytocin binding. Maximum expression and binding both occurred at oestrus, suggesting that regulation of the oxytocin receptor gene in the uterus occurs principally at the transcriptional, rather than at the translational, level. Failure to detect a significant increase in myometrial mRNA expression at oestrus may indicate that the endometrial and myometrial oxytocin receptors are of different isoforms.

We have cloned a 2.4-kb cDNA containing the complete coding sequence of ovine Mx from a lambda ZAP library constructed using RNA from the endometrium of a normal sheep on day 16 of pregnancy. Ovine Mx shows 80% similarity to human MxA. Human and mouse Mx are type-1 interferon (IFN)-induced genes that have previously been shown to confer resistance to influenza virus. The ovine Mx cDNA contains an open reading frame of 1962 nucleotides (nt) coding for a 653-amino-acid (aa) protein. The deduced translated sequence has consensus GTP-binding sites and similarity to the human MxA sequence (RKFLKERLARL) that has been shown to be essential for resistance against vesicular stomatitis virus (VSV). The presence of Mx mRNA was investigated by Northern blot analysis in the endometrium of non-pregnant sheep and between days 8 and 127 of pregnancy. Mx expression was detected at high levels between day 13 and day 20 of pregnancy. Furthermore, eightfold higher levels of Mx mRNA were detected in the pregnant versus the non-pregnant uterine horn in unilaterally pregnant sheep. Mx mRNA can be induced in sheep endometrium by ovine trophoblast interferon (IFN-tau).

In 1985 a second randomisation was initiated for women in the treatment arm of the Scottish Tamoxifen Trial either to stop tamoxifen at 5 years or to continue indefinitely. A preliminary analysis of outcome in 342 patients at a median follow-up of 6 years suggests that a worthwhile gain in disease control from continuing adjuvant tamoxifen beyond 5 years is unlikely. [Hazard ratio for events (relapse or death without relapse) is 1.27, 95% CI = 0.87 - 1.85.] There is a suggestion that therapy for longer than 5 years may increase the risk of endometrial carcinoma (P = 0.064).

The polymerase chain reaction (PCR) was used to generate a 131 bp cDNA encoding part of the sheep endometrial oxytocin receptor. The nucleotide sequence of this cDNA was 93.8% identical to the human oxytocin receptor sequence in this region. When used to probe Northern blots of sheep endometrial RNA the PCR product identified a 6.7 kb mRNA which appeared and disappeared during the oestrous cycle in parallel with the oxytocin receptor molecule as measured by ligand binding. The sheep endometrial receptor mRNA was significantly larger than the human myometrial mRNA (4.7 kb). It is suggested that the cloned cDNA described here is an appropriate probe for use where it is required to measure sheep oxytocin receptor mRNA.

There is now evidence from in vivo and in vitro studies that the rate of Schwann cell generation is regulated by the balance of two opposing signals, beta neuregulins and endothelins. The beta neuregulins promote the development of precursors to Schwann cells whereas endothelins retard it through an action on endothelin-B receptors. The present work has shown additional controls of this transition, and implicates AP-2 transcription factors, in particular AP-2 alpha, as negative regulators of Schwann cell generation. We found that both AP-2 alpha and AP-2 gamma are present in early embryonic nerves, whereas AP-2 beta was not. Isoform-specific analysis of AP-2 alpha showed that isoform 3 was most abundant with isoforms 1 and 2 present in lesser amounts; isoform 4 was absent. Maximal AP-2 alpha and AP-2 gamma mRNA expression occurred at embryonic day (E) 12/13 in the mouse and at E14/15 in the rat, which correlates with the presence of Schwann cell precursors in the nerve. In both rats and in mice, in vivo and in vitro, downregulation of AP-2 alpha mRNA and protein coincided with one of the main steps in Schwann cell development, the precursor-Schwann cell transition. Moreover, Schwann cell generation was delayed if this downregulation was prevented by enforced expression of AP-2 alpha in precursors. These studies suggest that AP-2 is involved in the control of the timing of Schwann cell development.

Background and Methods: The Scottish Adjuvant Tamoxifen Trial (main trial) was initiated in April 1978 to assess the effect of tamoxifen given to patients with breast cancer immediately after mastectomy (or mastectomy plus radiation therapy) (adjuvant arm) or only after the patients had had a relapse (control arm); 1323 patients were randomly assigned (667 to the adjuvant arm and 656 to the control arm). Results have been reported for the follow-up period from 2.5 through 8 years. In this article, we report updated results after a median follow-up of 15 years. If agreeable and eligible, patients who were disease free at 5 years in the adjuvant arm of the main trial were entered into a duration trial and randomly assigned either to stop taking tamoxifen (169 patients) or to continue taking it indefinitely until relapse or death (173 patients). For this update, we analyzed information on death, recurrence, survival, and other malignancies for all but 21 of the 560 living patients from the original and duration trials to determine the probabilities of total survival, systemic relapse of disease, and death from breast cancer. All statistical tests are two-sided. Results: The beneficial effect of adjuvant tamoxifen given for 5 years on the probability of total survival (P = .006), systemic relapse (P = .007), and death from breast cancer (P = .002) has been maintained through 15 years. No additional benefit was observed in those randomly assigned to continue taking tamoxifen beyond 5 years. Conclusion: Information from this study suggests that, if adjuvant tamoxifen is given to women with operable breast cancer, it need not be for more than 5 years.

Inherited retinal degenerations such as retinitis pigmentosa (RP) are characterized by progressive death of the photoreceptors due to apoptosis. To identify changes in gene expression associated with the degenerative state in RP retinas, expression profiling of apoptosis-related genes was performed using a gridded array technique.Total RNAs from RP and control retinas were used to generate radiolabeled cDNA probes to screen gridded membrane arrays of 205 apoptosis-related genes. Reverse transcription-polymerase chain reaction was used to generate probes corresponding to differentially expressed genes for Northern blot analysis and for mRNA in situ hybridization studies of retinal cryosections. Fluorescence immunocytochemistry was performed on retinal sections using available antibodies.By expression profiling, we identified upregulated expression of the mRNA for secreted Frizzled-related protein-2 (SFRP2) in RP retina in comparison with control. By Northern blot analysis, SFRP2 mRNA levels were 2- to 20-fold higher in RP samples than in controls. The localization of SFRP2 mRNA by in situ hybridization varied according to the degree of degeneration, from stratified in relatively well-preserved retinas to diffuse in the highly degenerative state. By immunofluorescence, SFRP2 protein in RP retinas was found mainly to colocalize with the cell adhesion and signal transducing protein beta-catenin.SFRPs can regulate apoptosis in vitro and appear to interact with the Wnt/Frizzled signaling pathway, which includes routes to apoptotic activation. Increased SFRP2 expression in RP retinas suggests that an altered pattern of Wnt signal transduction may be a step in the degenerative process linking causal mutations with eventual photoreceptor demise.

Although basic helix-loop-helix (bHLH) proteins play an important role in transcriptional control in many cell types, the role of HLH proteins in Schwann cells has yet to be assessed. In this study, we have analyzed the expression of the dominant negative HLH genes, Id1 to Id4 and the class A gene REB, during Schwann cell development. We found that mRNA derived from these genes was present in the Schwann cell lineage throughout development including embryonic precursors and mature cells. The mRNA levels were not significantly regulated during development. Nevertheless, by using antibodies against the four different Id proteins, we found clear regulation of some of these genes at the protein level, in particular Id 2, 4, and REB, both in amount and nuclear/cytoplasmic localization. All these proteins are found in the nuclei of Schwann cell precursors but are not seen in nuclei of Schwann cells of newborn nerves. We observed extensive overlap in Id expression, especially in Schwann cell precursors that co-expressed all four Id proteins and REB. We also showed that Id 1 and 2 were up-regulated as Schwann cells progressed through the cell cycle. These data indicate that HLH transcription factors act as regulators of Schwann cell development and point to the existence of as yet unidentified cell type-specific bHLH proteins in these cells.

The interaction of cells with the extracellular matrix plays a critical role in morphogenesis and cell differentiation. To define how Schwann cells might interact with the extracellular matrix, we chose to study the expression of the laminin/collagen receptor alpha1beta1 integrin during nerve development in the rat from embryonic day 14 to maturity. We found that this integrin is expressed predominantly on mature non-myelin-forming cells and only at very low levels on myelin-forming cells. Significant levels of this integrin were not detected on Schwann cell precursors or embryonic Schwann cells in vivo. Experiments using transected and crushed sciatic nerve showed that alpha1beta1 integrin expression is regulated at least in part by axonal contact. Furthermore, Schwann cell culture experiments showed that alpha1beta1 integrin levels are strongly upregulated by transforming growth factor-beta(s) and phorbol esters.

To determine whether, when primary breast cancer is treated by local excision supported by systemic therapy appropriate to the oestrogen receptor status (ER) of the tumour, local radiotherapy can be avoided.We carried out a randomised controlled trial in 585 patients aged less than 70 years with primary breast cancers of 4 cm or less in size in four specialist units and seven other hospitals in Scotland. After local excision of the tumour (1 cm margin) and an axillary lymph-node clearance or sample, all patients received systemic therapy with oral tamoxifen 20 mg daily or six 3-weekly intravenous bolus injections of cyclophosphamide 600 mg, methotrexate 50 mg, and fluorouracil 600 mg per m2, depending upon the ER concentration in the primary tumour. Patients were then randomly allocated to postoperative radical radiotherapy (50 Gy to breast with boost to the tumour bed) or to no further local treatment. The median follow-up of living patients was 5.7 years. The primary analysis was by intention to treat but since some patients did not receive systemic therapy appropriate to their ER status, a subsidiary analysis was restricted to 464 patients in whom all details of the protocol had been observed.In the primary analysis survival was equal in the radiotherapy and non-radiotherapy groups (hazard ratio [HR] 0.98, 95% CI 0.67-1.44). Event-free survival showed an advantage in the irradiated patients (HR 0.54, 95% CI 0.39-0.74), largely due to fewer loco-regional relapses (HR 0.20, 95% CI 0.12-0.33). The relapse rate in the ipsilateral breast was 24.5% in the non-irradiated group and 5.8% following breast irradiation. The subsidiary analysis confirmed these findings and indicated the advantage of radiotherapy irrespective of ER concentration. There was a non-significant trend towards fewer distant metastases in the irradiated group.After local excision of a primary breast cancer, we conclude that radiotherapy to the residual breast tissue is advisable even when selective adjuvant systemic therapy is given.

In 1985 a second randomisation was initiated for women in the treatment arm of the Scottish Tamoxifen Trial either to stop tamoxifen at 5 years or to continue indefinitely. A preliminary analysis of outcome in 342 patients at a median follow-up of 6 years suggests that a worthwhile gain in disease control from continuing adjuvant tamoxifen beyond 5 years is unlikely. [Hazard ratio for events (relapse or death without relapse) is 1.27, 95% CI = 0.87 - 1.85.] There is a suggestion that therapy for longer than 5 years may increase the risk of endometrial carcinoma (P = 0.064).

Using the rat sciatic nerve as a model for the study of Schwann cell differentiation we have identified a Schwann cell precursor, a distinct cell type present in developing nerves at a time when they are projecting to their target tissues. These cells develop into Schwann cells over a relatively short time in vivo. In vitro, they can generate Schwann cells if they are cultured in neuron-conditioned medium or in the presence of neu-differentiation factors (NDF) (neuregulins, heregulins, glial growth factor), a recently discovered family of growth factors expressed at high levels in neurons. Thus neu-differentiation factors may be important neuro-glia signalling molecules in the Schwann cell lineage. Later stages in the development of Schann cells, such as differentiation towards a myelin phenotype, can be studied using cultured Schwann cells. These cells dedifferentiate both in vivo and in vitro when they are deprived of axonal contact. Elevation of intracellular cyclic AMP levels in the absence of cell division causes high levels of expression of Po, the major myelin glycoprotein. TGF beta s and FGFs suppress this induction, while IGFs promote it.

All who are involved with the care of young women with breast cancer must be aware that it is now 100 years since George Beatson (1896) when only 47 years of age, dared to remove the ovaries of a 33-year-old Glasgow woman with progressing recurrent disease. A rapid and convincing remission occurred but, despite reporting this in the Lancet a year later, it was not until the 1930s that real interest in ovarian ablation developed. A few earlier reports had confirmed the effectiveness of the procedure but it was when Taylor (1934) first suggested the possibility of benefit from removing the ovaries at the time of mastectomy that interest seemed to increase. For the next 30 years the results of many small retrospective series were published with indirect comparisons of outcome from early (prophylactic or adjuvant) with that from late (post-relapse or “therapeutic”) ovarian ablation. Conflicting conclusions were drawn but the balance of opinion was in favour of the therapeutic approach, largely because of the dramatic and sometimes prolonged responses which could occur. It was argued that early ablation would be unnecessary in 40% and that the tumour would be unresponsive in 75% of the remainder leaving only 15% to benefit from prophylactic therapy.

OBJECTIVE--To determine any cardiac or vascular morbidity associated with long term treatment with tamoxifen given after mastectomy for primary breast cancer. DESIGN--Cohort study using linkage between database of a randomised trial and statistics of Scottish hospital inpatients to identify episodes of cardiac and vascular morbidity. SETTING--NHS hospitals in Scotland. SUBJECTS--1312 women who had undergone mastectomy for breast cancer and who were randomised either to a treatment group to receive adjuvant tamoxifen or to a control group to be given tamoxifen only on first relapse of disease. Maximum duration of tamoxifen treatment was 14 years. Total woman years of follow up were 9943. MAIN OUTCOME MEASURES--Randomised and observational comparisons of risk (expressed as hazard ratios) of myocardial infarction, other cardiac event, cerebrovascular disease, or thromboembolic event according to treatment allocated and between nonusers, former users, and current users of tamoxifen. RESULTS--Use of tamoxifen was associated with lower rates of myocardial infarction. Hazard ratio for women in control group was 1.92 (95% confidence interval 0.99 to 3.73) compared with women allocated to adjuvant treatment. The association was stronger for current use: hazard ratio for non-users was 3.49 (1.52 to 8.03) compared with current users. Current users of tamoxifen, however, had higher rates of thromboembolic events:hazard ratio for non-users was 0.40 (0.18 to 0.90) compared with current users. CONCLUSIONS--Our results provide further evidence that tamoxifen reduces the risk of myocardial infarction. Thromboembolic events should be carefully monitored in trials of tamoxifen, particularly those of prophylactic treatment, in which tamoxifen is given to healthy women.

The sheep endometrial oxytocin receptor plays a central role in determining the time at which luteolysis occurs during the oestrous cycle, and in the events leading to the establishment of pregnancy (the maternal recognition of pregnancy). Expression of the receptor in the uterus is controlled by ovarian steroid hormones, and by trophoblast interferon (IFN-tau). We report here studies on the second messengers involved in the effect of IFN-tau, and on the structure and expression of the oxytocin receptor. The receptor is expressed in ovine endometrial explants during culture, when the explants are taken during the luteal phase of the cycle; this process is partially blocked by inhibitors of protein kinase C, or by down-regulation of protein kinase C. Therefore it is suggested that protein kinase C, rather than tyrosine kinases, is involved in the effect of IFN-tau on oxytocin receptor expression. Northern blotting shows that in common with uterine oxytocin receptor mRNA in other species, the message is heterogeneous. cDNA sequencing indicates the sheep uterine oxytocin receptor is at least 2 amino acids longer than those of other species, and expression of the receptor in Cos-7 cells induces oxytocin responsiveness in terms of phosphoinositide turnover.

This paper describes the results of a national survey on the non-surgical treatment of early breast cancer in the UK relating to the management of ductal carcinoma in-situ (DCIS), and the rationale for the current status of the UK DCIS trial. The survey shows that there is considerable clinical uncertainty, which can only be resolved by the trial.

The oxytocin receptor, a seven transmembrane domain, G protein-linked receptor molecule, plays a central role in determining the endocrine function of the ruminant uterine endometrium. During non- pregnant cycles the control of this molecule by circulating steroid hormones leads to regression of the corpora lutea. The kinetics of the mechanisms involved determine the time at which luteolysis occurs, and therefore the length of the oestrous cycle. In pregnancy, secretions of the trophoblast block endometrial oxytocin receptor gene expression and lead to luteal maintenance. An understanding of the molecular mechanisms involved in the steroidal control of oxytocin receptor gene expression will provide an explanation for the relative constancy of oestrous cycle lengths in non-pregnant animals. Unravelling the way in which trophoblast products block expression of the oxytocin receptor gene will lead to a better understanding of the reasons for the high rate of embryonic loss in domestic ruminants.

This report gives the responses of general surgeons in Scotland to two questionnaires. Satisfactory rates were obtained: 82% for the more detailed survey in 1988 and 62% for the second survey (1991), where nonrespondents were not followed up. In 1988 the rationale was the poor participation in the Scottish breast conservation trial while the 1991 survey further investigated the diversity of surgical opinion identified in the first. The limited trial support in 1988 was mainly due to reluctance to accept all treatment options. The majority were prepared to consider trial participation although 47% believed this compromised doctor-patient relationships. Although breast-conserving therapy was widely supported, many different views on management were encountered, both in the degree of influence of specific factors and in the decisions taken in relation to them. We believe these surveys have re-inforced a need for management guidelines, particularly as around half the patients with symptomatic breast cancer were being treated in non-specialist units.

The endometrial oxytocin receptor occupies a central point in the choice between luteolysis and pregnancy in ruminants. Receptor expression determines the time at which luteolysis occurs in nonpregnant animals, and thereby determines the duration of the oestrous cycle. Inhibition of receptor expression by trophoblast interferon (IFN) blocks the process of luteal regression and leads to continued progesterone secretion and the successful growth of the conceptus. Trophoblast IFN is probably required from the time of normal luteolysis during the cycle until luteal oxytocin concentrations of pregnancy decline, thus removing the stimulatory mechanism for the release of the episodes of prostaglandin F2 alpha required for luteolysis.

This paper presents results, 5 years after closure, of a randomized trial comparing adjuvant with postrelapse tamoxifen in 747 women with histological node-negative breast cancer. Two hundred thirty-six disease-free patients on adjuvant therapy were secondarily randomly assigned at 5 years to stop or to continue tamoxifen until relapse. Adjuvant tamoxifen, taken for a median duration of 60 months, has significantly prolonged disease-free survival overall (P = .0001), in the 214 premenopausal group (P = .018), in the 533 postmenopausal group (P = .0026), and for the 246 patients with estrogen receptor levels greater than 19 fmol/mg of protein (P = .0032); distant relapse has also been delayed overall (P = .029). Total survival comparison by Kaplan-Meier life-table analysis shows a nonsignificant trend in the same direction (P = .07). Adjuvant tamoxifen has also reduced the incidence of contralateral breast cancer and of death from myocardial infarction. No increase in the incidence of endometrial cancer has been found.

OBJECTIVE--To investigate the incidence of fatal myocardial infarction in women in the two randomised arms of the Scottish adjuvant tamoxifen trial. DESIGN--Retrospective review of hospital notes to determine with the greatest possible certainty women who had died of an acute myocardial infarction. SETTING--Scottish Cancer Trials Office, the University of Edinburgh. PATIENTS--1070 postmenopausal women with operable breast cancer who were randomised to receive either adjuvant tamoxifen for five years or until relapse (539 patients) or tamoxifen for at least six weeks on the confirmation of first recurrence (531 patients). MAIN OUTCOME MEASURES--Incidence of fatal myocardial infarction in women with no known or suspected systemic cancer. RESULTS--Of the 200 women who died in the adjuvant tamoxifen arm of the trial, 44 were free of cancer at death and 10 of these died of myocardial infarction. In the observation arm 251 women died, of whom 61 showed no evidence of systemic cancer and 25 had a fatal myocardial infarction. The incidence of fatal myocardial infarction in the two groups was significantly different (chi 2 = 6.88, p = 0.0087). CONCLUSION--Tamoxifen given for at least five years as adjuvant therapy for breast cancer seems to have a cardioprotective oestrogen-like effect in postmenopausal women.

Adjuvant systemic therapy is now an important and recognized part of the initial management of patients with operable breast cancer. Its value in delaying relapse and prolonging total survival is established for disease of poor prognosis. For premenopausal patients the currently advised treatment is a 6 months course of CMF polychemotherapy and for postmenopausal patients it is daily tamoxifen for 2-5 years. For patients with disease of good prognosis there is a need to evaluate, within randomized trials, the usefulness of newer biological indicators of prognosis to improve selection for and of treatment. Continued monitoring of long-term results for delayed morbidity is also necessary.

A brief resume of adjuvant endocrine therapy for operable breast cancer is given. This was first suggested in the 1930's but has only become accepted in the last 10-15 years. The reason for the lack of survival benefit in the first randomised trial, which began in 1948 in Manchester, was thought to be due to the increasing use of hormone therapy for metastases. Revival of interest came with the survival gain reported in the Toronto ovarian trial and the success in post-menopausal patients of the non-toxic anti-oestrogen tamoxifen. The different dose schedules used in the various large tamoxifen trials could explain the confusingly variable results in the literature. Combined analysis of trial results indicates that CMF is the adjuvant therapy of choice for pre-menopausal patients but this therapy may in part be acting through the ovaries. The Scottish and NATO trials have an overall survival advantage from adjuvant tamoxifen, even in pre-menopausal patients, and both have shown results to be independent of oestrogen receptor (ER) status. Whether the extra 3 years given in Scotland adds an additional benefit over the more commonly used 2-year course is uncertain. A statistically invalid look at selected data in the Scottish trial suggests that, in ER positive cases, post-relapse tamoxifen may have as great an effect on total survival as adjuvant use, a finding similar to that suggested by the first ovarian ablation trial and one requiring continued review.

Southern blotting of bovine genomic DNA indicated the presence of at least 3 bovine tIFN genes. The full DNA sequence of one of these genes, thought to be expressed in trophoblast, has been determined, including 193 bp of 5' non-coding region. The inferred amino acid sequence of bovine tIFN is more similar to ovine tIFN (80%) than to bovine IFN-alpha II (70%). The 5' flanking sequence has some similarity with bovine IFN-alpha II, and may contain a viral response element. A recombinant bovine alpha I interferon (Ciba Geigy; brIFN), resembling tIFN, extended oestrous cycle length in sheep when administered by intrauterine infusion over the period, Days 12-15 after oestrus, when maternal recognition of pregnancy occurs. Intramuscular injection was only effective at the doses used if given over a longer period (i.e. Days 9-15). Our experiments indicate that both tIFN and brIFN inhibit luteolysis by preventing a rise in endometrial oxytocin receptor concentrations, and suggest that tIFN achieves this by extending the time for which progesterone suppresses oxytocin receptor development. Further studies are required to confirm this hypothesis and to elucidate the interaction of the effects of progesterone and tIFN in endometrial cells.

The establishment of pregnancy in domestic ruminants depends upon the continued secretion of progesterone by the corpora lutea. In non-pregnant cycles the corpora lutea regress between days 12-15 after oestrus in the sheep; this process must be blocked to ensure continued exposure of the uterus to progesterone. This review discusses the evidence that embryonic products are involved in the maintenance of corpus luteum function, the identification of factors which may be responsible for this maintenance and the probable mechanism of action. The discussion centres on the recent identification of a trophoblast interferon which is thought to be the major trophoblastic factor preventing luteolysis in sheep and cattle.

Analysis of ovine conceptus RNA by slot blotting, Northern analysis and nested polymerase chain reaction failed to detect oxytocin–neurophysin prohormone mRNA. Probes used hybridized with both the 3' end of the prohormone mRNA and the oxytocin-coding sequence. Northern analysis of bovine and porcine conceptus RNA was also negative, and polymerase chain reaction demonstrated oxytocin–neurophysin mRNA in ovine corpus luteum, but not in human corpus luteum or decidua, or in ovine endometrium. Infusion of oxytocin into the uterine lumen in cyclic ewes between days 9 and 19 or 20 after oestrus failed to prolong the luteal phase of the cycle and had no effect on endometrial oxytocin receptor concentrations or uterine prostaglandin F secretion. Oxytocin administered systematically prevented luteolysis and reduced uterine prostaglandin F secretion. Taken together, these data suggest that blastocyst-derived oxytocin is unlikely to contribute to corpus luteum maintenance in early pregnancy. They are inconsistent with a previous report that the ovine blastocyst synthesizes and secretes oxytocin. Journal of Endocrinology (1991) 130, 443–449

Late-pregnant goats were separated into two groups. A control group of four goats had small (approximately 3 ml) volumes of secretion expelled from one mammary gland at infrequent intervals between day 130 of gestation and parturition. An experimental group of five goats had as much secretion as possible removed from both glands twice daily beginning on day 137 of gestation and continuing until parturition. After parturition, both groups were milked twice daily. Regular 'milking out' before parturition stimulated secretion of triglyceride by the mammary gland, and most of the fatty acids secreted in the triglyceride before parturition had a chain length of 18 carbons. Secretion of 6-14-carbon chain-length fatty acids in the milk triglycerides increased after parturition. There was no evidence that the onset of secretion of medium-chain and long-chain fatty acids occurred at different times in the control animals. It is concluded that the onset of secretion of medium-chain and long-chain fatty acids in milk triglycerides can be dissociated, although both are normally synchronized with parturition. Removal of secretion by the offspring at parturition may be a stimulus for the onset of secretion of long-chain fatty acids, but the onset of secretion of medium-chain fatty acids is brought about by some other mechanism.

The treatment of lactating goats with ACTH (single intramuscular injection) or cortisol (systemic infusion) resulted in an increase in milk yield and in the secretion of lactose, citrate and glucose into milk. The concentration of glucose in arterial plasma was also increased, resulting in a greater supply of glucose to the mammary gland. After ACTH treatment mammary uptake of glucose from the circulation did not increase and the balance between mammary uptake of glucose from blood and mammary output of glucose 'equivalents' into milk was significantly reduced. The results show that ACTH and cortisol can increase milk yield and lactose secretion by altering mammary metabolism of glucose. J. Endocr. (1984) 101, 203–211

A prospective study has been carried out in 172 women to determine the sensitivity of methods to detect occult metastatic disease in the skeleton and liver. With the exception of bone scintiscans, the results of these tests bore little relationship to recurrence rates. On the other hand, knowledge of the histopathology of the lower axillary (pectoral) lymph nodes is of value in this respect. A follow-up study is also reported which confirms the importance of accurate measurements of the primary tumour clinical node status and oestrogen receptor contact of the tumour in defining prognostic groups. Elastosis (estimated in 165 tumours) did not prove to be a useful prognostic index.

The theoretical possibility of designing the blading of a conventional windmill so as to match the optimum loading for maximum output at two different operating conditions (i.e., at two different values of the ratio of tip speed to wind speed) is investigated using the vortex blade element theory. The theory of optimum loading is developed, including the effect of profile drag. For the range of parameters considered, it is shown that the effect of profile drag on blade loading is quite small, although the effect on efficiency is significant. The simpler theory, neglecting profile drag, and first presented by Glauert, then is used to design three sets of blading which match the Glauert loading conditions at two conditions, tip speed ratios of 4 and 5. The first design is for fixed blading and the other two involve pitch changes of 1.5° and 2° between the two conditions, the latter two showing a moderate degree of taper and being more desirable from a structural design point of view. It is concluded that the possibility of designing blading having high efficiency over a considerable range of operating conditions exists and can be used.