Pharmacokinetics of anastrozole and tamoxifen alone, and in combination, during adjuvant endocrine therapy for early breast cancer in postmenopausal women: a sub-protocol of the 'Arimidex and tamoxifen alone or in combination' (ATAC) trial

The ATAC trial evaluates in a randomized, double-blind design, Arimidextrade mark (anastrozole) alone or in combination with tamoxifen, relative to tamoxifen alone as 5-year adjuvant treatment in postmenopausal women with early breast cancer. Patients included in the pharmacokinetic (PK) sub-protocol had been in ATAC for > or =3 months, taking their medication in the morning and were 100% compliant for the preceding 14 days. Blood samples were collected 24 +/- 4 h after last dose. Trough (C(min)) plasma concentrations of anastrozole, tamoxifen and desmethyltamoxifen (DMT) were measured by validated methods. The PK results were based on a total of 347 patients (131 anastrozole (1 mg o.d.), 111 tamoxifen (20 mg o.d.), 105 anastrozole and tamoxifen (1 and 20 mg o.d. respectively)). The geometric mean steady-state trough plasma concentrations of tamoxifen and DMT were statistically equivalent in patients receiving tamoxifen alone or in combination with anastrozole: geometric mean tamoxifen = 94.8 ng ml(-1)and 95.3 ng ml(-1)in tamoxifen alone and combination groups, respectively; geometric mean DMT = 265.1 and 277.6 ng ml(-1)in the tamoxifen and anastrozole and tamoxifen groups, respectively. The geometric mean anastrozole levels were 27% lower (90% Cl 20-33%;P< 0.001) in the presence of tamoxifen than with anastrozole alone. Baseline plasma oestradiol levels were not obtained in the PK sub-protocol, however, such information was available from a similar ATAC sub-protocol, which evaluated bone mineral density. Mean oestradiol levels were 21.3, 19.3, and 21.6 pmol l(-1)prior to treatment and 3.7, 20.9 and 3.6 pmol l(-1)after 3 months in the anastrozole, tamoxifen, and combination groups, respectively (n = 167). On-treatment values were below the detection limit (3 pmol l(-1)) in 43.6 and 38.5% of the anastrozole alone and anastrozole in combination with tamoxifen groups, respectively. As a result of (a) the lack of effect of anastrozole on tamoxifen and DMT levels and (b) the observed fall in blood anastrozole levels having no significant effect on oestradiol suppression by anastrozole, we conclude that the observed reduction in anastrozole levels by tamoxifen is unlikely to be of clinical significance when anastrozole and tamoxifen are administered together.

Costimulatory blockade by the induction of an endogenous xenospecific antibody response

Xenogeneic tissues induce vigorous T cell immunity, reflecting the ability of costimulatory molecules to function across species barriers. We describe a strategy to inhibit costimulation that exploits species differences using the model of porcine pancreatic islet transplantation into mice. Mice were immunized with chimeric peptides that contained a known T cell epitope and selected sequences of the porcine costimulatory molecule CD86. This resulted in anti-peptide antibody responses that recognized intact porcine CD86, blocked costimulation by porcine CD86 but not murine CD86 in vitro, and prolonged the survival of porcine islet grafts in vivo. This strategy of inducing endogenous donor-specific costimulatory blockade has potential clinical applicability.

DNA-PK-independent rejoining of DNA double-strand breaks in human cell extracts in vitro

PURPOSE

To investigate the role of DNA-dependent protein kinase (DNA-PK) in the rejoining of ionizing radiation-induced DNA double-strand breaks (dsb).

MATERIALS AND METHODS

This study employed previously described in vitro assays that utilize nuclei or 'naked' DNA prepared from agarose-embedded cells as a substrate and S-HeLa cell extracts as a source of enzymes. Rejoining of dsb in these assays is absolutely dependent on cell extract and it proceeds, under optimal reaction conditions, to an extent similar to that observed in intact cells. Results were confirmed in a plasmid-based assay for in vitro rejoining of dsb.

RESULTS

It is shown that concentrations of wortmannin completely inhibiting DNA-PK activity profoundly affect the rejoining of dsb in vivo, but have no effect on dsb rejoining in vitro. Furthermore, fractionation of cell extracts using ammonium sulphate precipitation, generates protein fractions that are able to support dsb rejoining, despite the fact that they do not contain detectable amounts of either DNA-PKcs or Ku80. Efficient rejoining of dsb in vitro is also observed with extracts of MO59J cells that lack DNA-PK activity. Finally, rejoining of dsb remains unaffected by wortmannin in a plasmid-based assay, and is also detectable with extracts of MO59J cells.

CONCLUSIONS

These findings are in contrast with genetic studies demonstrating a requirement for DNA-PK activity for efficient rejoining of dsb in vivo. The difference between in vitro and in vivo results may not be attributed to chromatin structure since wortmannin was without an effect when using nuclei as a substrate. It is speculated that the differences between in vivo and in vitro results can be explained either by assuming the operation of multiple pathways in dsb rejoining, some of which do not require DNA-PK, or by postulating a purely regulatory/damage-sensing role for DNA-PK in intact cells but no direct involvement in dsb rejoining.

Octreotide as primary therapy for acromegaly

The effects of octreotide (up to 5 yr) as primary treatment in 26 patients with acromegaly were compared with those in 81 patients with acromegaly who received octreotide as secondary or adjunctive therapy after previous surgery and/or pituitary radiation. These patients were part of a multicenter study that took place between 1989-1995. The study was divided into 3 phases beginning with a 1-month placebo-controlled treatment period followed by a 1-month washout period. In the second phase, patients were randomized to treatment with either 100 or 250 micrograms octreotide, sc, every 8 h for 6 months. Octreotide was then discontinued for 1 month and reinitiated at the lower dose for a total mean treatment duration of 39 months. The dose was titrated by each investigator to improve each patient's individual response, which included improvement in symptoms and signs of acromegaly as well as reduction of GH and insulin-like growth factor I (IGF-I) into the normal range. In the second phase of the study, in which patients were randomized to either 100 or 250 micrograms octreotide, three times daily, mean integrated GH and IGF-I concentrations after 3 and 6 months were equivalent in the primary and secondary treatment groups. During long term open label treatment, mean GH fell from 32.7 +/- 5.2 to 6.0 +/- 1.7 micrograms/L 2 h after octreotide injection in the primary therapy group and remained suppressed for a mean period of 24 months (range, 3-60 months). The mean final daily dose was 777 micrograms. In the patients receiving secondary treatment, mean GH fell from 30.2 +/- 7.6 to 5.6 +/- 1.1 micrograms/L after 3 months and remained suppressed for the remainder of the study (average dose, 635 micrograms daily). Mean IGF-I concentrations fell from 5.2 +/- 0.5 x 10(3) U/L (primary treatment group) and 4.7 +/- 0.4 x 10(3) U/L (secondary treatment group) to a mean of 2.2 +/- 0.3 x 10(3) U/L in both groups after 3 months of open label treatment and remained suppressed. IGF-I was reduced into the normal range during at least half of the study visits in 68% of the primary treatment group and in 62% of the secondary treatment group. Patients whose GH levels fell to at least 2 SD below the baseline mean GH were considered responders. There was no significant difference in the percentage of responders in the primary and secondary treatment groups (70% vs. 61%), nor was there a statistical difference in the mean GH concentrations between the groups. Symptoms of headache, increased perspiration, fatigue, and joint pain were reported at baseline by 46%, 73%, 69%, and 85%, respectively, of patients in the primary therapy group and improved during 3 yr of octreotide treatment in 50-100%. Similarly, these acromegaly-related symptoms were reported by 62%, 58%, 78%, and 60% of patients in the secondary therapy group, and improvement was noted in 62-88%. Pituitary magnetic resonance imaging scans were available in 13 of 26 patients in the primary treatment group before and after 6 months of octreotide treatment. Tumor shrinkage was observed in 6 of 13 patients, with reduction in tumor volume greater than 25% in only 3. Of 6 patients with documented tumor shrinkage, IGF-I was reduced into the normal range in 4 patients. Of the 7 remaining patients in whom tumor shrinkage was less than 10%, IGF-I was reduced into the normal range in 4 patients. Of the 7 remaining patients in whom tumor shrinkage was less than 10%, IGF-I was reduced into the normal range in 5 patients. The degree of tumor shrinkage did not correlate with the percent reduction in IGF-I or GH. In summary, octreotide was equally effective in 26 previously untreated acromegalic patients (primary treatment group) and 81 patients previously treated with either surgery or pituitary radiation (secondary treatment group). These observations call into question the current practice of surgical resection of all newly diagnosed GH-secreting pituitary adenomas regardless of the likelihood of cure. (AB

Current treatment guidelines for acromegaly

Acromegaly, an indolent disorder of growth hormone (GH) hypersecretion is most typically caused by a somatotroph cell adenoma and may be treated by several modalities. Transsphenoidal surgical resection of micro-adenomas by experienced neurosurgeons results in biochemical normalization (postglucose GH <2 ng/mL, assay-dependent, age- and sex-matched IGF-I levels) in 70% of patients. However, over 65% of GH-secreting adenomas are invasive or macroadenomas, and over 50% of these patients have persistent postoperative GH hypersecretion. Irradiation of adenomas results in attenuation of GH secretion to more than 5 ng/mL in 50% of subjects after 12 yr. However, the percent of parents who normalize IGF-I levels is less certain. Most of these patients develop associated pituitary failure and rarely develop other local adverse effects. About 60% of patients receiving somatostatin analogs achieve normalized IGF-I levels. Efficacy of medical management with somatostatin analogs may be improved by increasing injection frequency, changing delivery modes to depot preparations, and in the future, development of novel SRIF receptor subtype-specific analogs. An integrated approach to acromegaly management based upon relative risks and benefits of the currently available therapeutic modes is presented that allows for a national individualized strategy designed to achieve maximal biochemical control of GH hypersecretion and elevated IGF-I levels.

A study of bereavement in an intensive therapy unit

This study explores the experiences of relatives of patients who died in an ITU. It describes bereaved relatives' perceptions of a follow-up programme. Needs of relatives at time of death are identified. Bereaved relatives' perceptions of social support are included. Other problems present following the death of a loved one are discussed, including disposal of belongings.

Adequacy of information and acceptability of pain relief as assessed by a postpartum questionnaire

An audit cycle has been completed looking at the availability of information about different types of anaesthesia in labour, their usage and the degree of maternal satisfaction. The initial audit 7 years ago led to the production of an information leaflet on pain relief in labour. The current audit (1996) demonstrated that the majority of patients receive the leaflet and find the information useful. The leaflet may have helped improve satisfaction and selection of analgesia in primigravide. However, the leaflet needs updating to include some information on caesarean section now that this has become such a common form of delivery.

Skin tone, hostility, and blood pressure in young normotensive African Americans

Several studies have found a positive relationship between darkness of skin tone and blood pressure in African Americans. This has raised speculation about the relative contributions of genetic and/or psychosocial factors in the mediation of this relationship. Using a laboratory stress protocol, we performed cardiovascular reactivity testing with 42 male and 40 female African-American college students after pre-testing them on measures of hostility using four psychometric scales derived from the Minnesota Multiphasic Personality Inventory (MMPI). Skin tone measures were obtained with a reflectance spectrophotometer. In the combined sample of males and females, we found a weak but statistically significant positive relationship between darker skin tone and systolic blood pressure (p = 0.03). However, males were significantly darker than females (p = .005) suggesting that the skin tone and blood pressure relationship is an artifact of gender. No differences in patterns of cardiovascular habituation or levels of hostility were found between dark and light subjects. Discussion of these results focuses on the weak statistical relationship found in this and other studies and the specificity of previous findings based on educational and socioeconomic factors.

Critical care nurses' perception of a bereavement follow-up service

Over the last decade, care of patients' relatives has increasingly been seen to be of growing importance in the holistic approach to nursing care. Care of recently bereaved people has been encompassed within this and is now being seen as part of the nurses' role. Although there has been little empirical research, there is an increasing school of thought with the belief that much improvement can be achieved in the care of bereaved people in acute settings. The aim of this report is to give an insight into benefits and failings of a bereavement follow-up service within a critical care setting, as perceived by nurses.

Variants of the melanocyte-stimulating hormone receptor gene are associated with red hair and fair skin in humans

Melanin pigmentation protects the skin from the damaging effects of ultraviolet radiation (UVR). There are two types of melanin, the red phaeomelanin and the black eumelanin, both of which are present in human skin. Eumelanin is photoprotective whereas phaeomelanin, because of its potential to generate free radicals in response to UVR, may contribute to UV-induced skin damage. Individuals with red hair have a predominance of phaeomelain in hair and skin and/or a reduced ability to produce eumelanin, which may explain why they fail to tan and are at risk from UVR. In mammals the relative proportions of phaeomelanin and eumelanin are regulated by melanocyte stimulating hormone (MSH), which acts via its receptor (MC1R), on melanocytes, to increase the synthesis of eumelanin and the product of the agouti locus which antagonises this action. In mice, mutations at either the MC1R gene or agouti affect the pattern of melanogenesis resulting in changes in coat colour. We now report the presence of MC1R gene sequence variants in humans. These were found in over 80% of individuals with red hair and/or fair skin that tans poorly but in fewer than 20% of individuals with brown or black hair and in less than 4% of those who showed a good tanning response. Our findings suggest that in humans, as in other mammals, the MC1R is a control point in the regulation of pigmentation phenotype and, more importantly, that variations in this protein are associated with a poor tanning response.

TRP-1 expression correlates with eumelanogenesis in human pigment cells in culture

We have investigated the relationship in human cultured normal and malignant melanocytes between the accumulation of mRNAs encoding tyrosinase and tyrosinase-related protein-1 (TRP-1), the activity of tyrosinase and the presence of melanin. Tyrosinase mRNA correlates with tyrosinase activity and with the presence of pheomelanin, eumelanin or both melanin types. In contrast TRP-1 mRNA is only detectable in cells containing eumelanin, which suggests a role for TRP-1 in the eumelanin synthesis pathway.

Bereavement follow-up service in intensive care

Following the death of a patient nurses sometimes wonder later how the surviving relatives have coped with the death of their loved one and whether there was any further help that could have been given. This report describes services available to bereaved relatives in Intensive Care Units (ICUs) throughout the UK and how, with limited resources, a formal follow-up service to all bereaved relatives can be achieved.