CDP840: a novel inhibitor of PDE-4

We present the in vitro characterization of a novel phosphodiesterase type 4 inhibitor, CDP840 (R-[+]-4-[2-¿3-cyclopentyloxy-4-methoxyphenyl¿-2-phenylethyl]pyridine), which has shown efficacy in a phase II allergen challenge study in asthmatics without adverse effects. CDP840 potently inhibits PDE-4 isoenzymes (IC50 2-30 nM) without any effect on PDE-1, 2, 3, 5, and 7 (IC50 > 100 microM). It exhibited no significant selectivity in inhibiting human recombinant isoenzymes PDE-4A, B, C or D and was equally active against the isoenzymes lacking UCR1 (PDE-4B2 and PDE-4D2). In contrast to rolipram, CDP840 acted as a simple competitive inhibitor of all PDE-4 isoenzymes. Studies with rolipram indicated a heterogeneity within all the preparations of PDE-4 isoenzymes, indicative of rolipram inhibiting the catalytic activity of PDE-4 with both a low or high affinity. These observations were confirmed by the use of a PDE-4A variant, PDE-4A330-886, which rolipram inhibited with low affinity (IC50 = 1022 nM). CDP840 in contrast inhibited this PDE-4A variant with similar potency (IC50 = 3.9 nM), which was in good agreement with the Kd of 4.8 nM obtained from [3H]-CDP840 binding studies. Both CDP840 and rolipram inhibited the high-affinity binding of [3H]-rolipram binding to PDE-4A, B, C, and D with similar Kd app (7-19 nM and 3-5 nM, respectively). Thus, the activity of CDP840 at the [3H]-rolipram binding site was in agreement with the inhibitor's activity at the catalytic site. However, rolipram was approximately 100-fold more potent than CDP840 at inhibiting the binding of [3H]-rolipram to mouse brain in vivo. These data clearly demonstrate that CDP840 is a potent selective inhibitor of all PDE-4 isoenzymes. In contrast to rolipram, CDP840 was well-tolerated in humans. This difference, however, cannot at present be attributed to either isoenzyme selectivity or lack of activity in vitro at the high-affinity rolipram binding site (Sr).

Assessment of upwind dinghy sailing performance using a Virtual Reality Dinghy Sailing Simulator

The ability of fourteen competitive helmsmen of different skill levels to sail a standard course towards the wind (upwind) was assessed using a virtual reality sailing simulator. The simulator consisted of a Laser dinghy deck which pivoted between two supports and was dynamically controlled by a computer driven pneumatic ram. Computer generated graphics realistically reproduced helming, sheeting, tacking and boat trim. After familiarisation with the simulator, subjects performed a standard 1 km upwind test and were ranked according to their completion time. The subjects were then asked to fill out a questionnaire to obtain an estimate of how effectively the simulator reproduced the conditions of actual sailing. Mean scores showed the sailors considered overall feel and simulation of physical movement as "good" (5 on a scale of 1 to 6). Rankings for the upwind test were compared with independent competition rankings for each subject. Overall time to complete the upwind test correlated well with a subject's external ranking (Spearman's rank order r=0.99). The results indicate that the test used can differentiate between variations in upwind sailing performance over a wide range of ability. The simulator thus provides for the first time a method of measuring and analysing a sailor's performance in a controlled laboratory setting.

Receptor-mediated endocytosis of albumin by kidney proximal tubule cells is regulated by phosphatidylinositide 3-kinase

Receptor-mediated endocytosis of albumin is an important function of the kidney proximal tubule epithelium. We have measured endocytosis of [125I]-albumin in opossum kidney cells and examined the regulation of this process by phosphatidylinositide 3-kinase (PI 3-kinase). Albumin endocytosis was inhibited by both wortmannin (IC50 6.9 nM) and LY294002 (IC50 6.5 microM) at concentrations that suggested the involvement of PI 3-kinase in its regulation. Recycling rates were unaffected. We transfected OK cells with either a wild-type p85 subunit of PI 3-kinase, or a dominant negative form of the p85 subunit (Deltap85) using the LacSwitch expression system. Transfects were screened by immunoblotting with anti-PI 3-kinase antibodies. Under basal conditions, transfects demonstrated no expression of p85 or Deltap85, but expression was briskly induced by treatment of the cells with IPTG (EC50 13.7 microM). Inhibition of PI 3-kinase activity by Deltap85 was confirmed by in vitro kinase assay of anti-phosphotyrosine immunoprecipitates from transfected cells stimulated with insulin. Expression of Deltap85 resulted in marked inhibition of albumin endocytosis, predominantly as a result of reduction of the Vmax of the transport process. Expression of p85 had no significant effect on albumin uptake. The results demonstrate that PI 3-kinase regulates an early step in the receptor-mediated endocytosis of albumin by kidney proximal tubular cells.

Inhibition of protein synthesis by acid in L6 skeletal muscle cells: analogies with the acute starvation response

Impaired protein synthesis (PS) occurs in skeletal muscle during acute starvation. Even though it is well established that uraemic metabolic acidosis (MA) stimulates protein degradation (PD) and is a major contributor to skeletal muscle wasting in chronic renal failure, the accompanying effects of MA on PS are much less clear. Previous work has shown that, in cultured L6 skeletal muscle cells, PD and leucine oxidation are stimulated by acid. The aim of the present study was to determine whether acid (like acute starvation) can also inhibit PS. PS (14C-phenylalanine incorporation) was measured in L6 cells in MEM + 2% serum at acid pH (7.1) or control pH (7.5). After 24 h, acid inhibited PS (7.7 +/- 0.2 vs. 8.9 +/- 0.1 nmol Phe/4 h/35-mm culture well in controls, p = 0.01) and this was maintained at 72 h. In vitro this could arise because acid only inhibits the rapid PS occurring in dividing cells. However, when division was abolished with 10(-5) mol/l cytosine arabinoside, PS inhibition by acid still occurred (6.9 +/- 0.1 vs. 8.3 +/- 0.2 at control pH, p < 0.05). Acid also had no effect on the specific radioactivity of cellular phenylalanine, suggesting that the impaired PS was not a consequence of inadequate labelling of this pool. Elevated PD and impaired PS together led to loss of 7% of the total protein in only 28 h (-21 +/- 3 microg/well, p = 0.004). This combination of impaired PS with increased PD and increased leucine oxidation in response to acid resembles the response of skeletal muscle to acute starvation. These superficial similarities between the starvation state and MA suggest that fundamental metabolic signals may occur which are common to both states.

Correcting impotence in the male dialysis patient: experience with testosterone replacement and vacuum tumescence therapy

Sexual dysfunction remains a common and often distressing problem in the male dialysis population. Traditionally its management has consisted of correction of anemia, optimization of dialysis, removal of implicated medication, and finally depot injections of a testosterone ester. At a dedicated renal impotence clinic, we studied the effectiveness of testosterone replacement in men with biochemically proven hypogonadism and then vacuum tumescence therapy in those with continued erectile dysfunction. Depot testosterone was given to 27 patients (aged 52.4+/-2.5 years; duration of dialysis, 2.00+/-0.40 years; and duration of sexual dysfunction, 2.92+/-0.49 years): sexual function was fully restored in only three (11.1%), and two gradually lost the response over 18 months. Nineteen patients (70.3%) had partial responses, varying from an increased sense of well-being alone to restored sexual function apart from an impairment of the duration of penile erection. Five patients (18.5%) had no response, and testosterone was contraindicated in another four. Four of the treated patients (14.8%) reported fluid retention. Vacuum tumescence devices were then offered to 32 patients who remained impotent but declined by six. Twenty-six patients (aged 49.6+/-2.2 years; duration of dialysis, 2.50+/-0.58 years; and duration of sexual dysfunction, 3.26+/-0.56 years) used the devices, with 19 (73.1%) having full correction of their erectile dysfunction; six also continued with depot testosterone to maintain their libido. Penile discomfort was described by five patients (19.2%) whose potency was not restored. A further five predialysis patients have used the devices, and all had correction of their erectile dysfunction. The correction of biochemical hypogonadism in the male dialysis population with testosterone rarely restores sexual function to normal, whereas vacuum tumescence therapy corrects penile erection dysfunction in most patients.

Inhibin immunohistochemistry applied to ovarian neoplasms: a novel, effective, diagnostic tool

Immunohistochemistry using monoclonal antibodies against human inhibin, a peptide hormone produced by ovarian granulosa cells to inhibit follicle-stimulating hormone (FSH), has been recently applied to diagnostic anatomic pathology. This investigation hypothesizes that inhibin immunohistochemistry will aid in the crucial clinical distinction between sex cord-stromal and other primary ovarian neoplasms. Available H&E slides and clinical information from a retrospective surgical series of 186 primary ovarian tumors were reviewed to verify diagnoses, and representative paraffin sections were immunostained with anti-inhibin (R1 monoclonal, Serotec, Kidlington, Oxford, UK). Immunoreactivity was graded as weak/strong (W/S), and the proportion of strong staining cells was coded as follows: S1 = <10%, S2 = 10%-50%, S3 = >50%, respectively. Inhibin immunoreactivity for 137 sex cord-stromal lesions was as follows: 100% of 66 granulosa cell tumors: 80% S3, 20% S2; 100% of 17 Sertoli-stromal tumors: 90% S3, 10% S2; 100% of 13 hyperplastic follicular/stromal lesions: 90% S3, 10% S2; 100% of six steroid cell tumors: 100% S3; 90% of 18 thecomas: 40% S3, 10% S2, 10% S1, 30% W; 0% of 12 fibromas, three myxomas, and two sclerosing stromal tumors. None (0 of 49) of the other ovarian neoplasms exhibited inhibin: 22 carcinomas, 12 carcinosarcomas, seven small cell carcinomas, six germ cell tumors, and two lymphomas. In the typical case, the distinction between sex cord-stromal and other ovarian neoplasms requires nothing more than routine pathological examination. In diagnostically challenging cases, our data indicate that inhibin immunohistochemistry is a very useful adjunct because granulosa and sertoli-stromal tumors are positive whereas other potential mimickers have been negative thus far.

Role of an improvement in acid-base status and nutrition in CAPD patients

Short-term correction of metabolic acidosis in normal and uremic subjects has been shown to decrease protein degradation, but the long-term effects of better correction of acidosis on nutrition in ESRF are unknown. The aim of this study was to assess the possible benefits, in the nutritional state and morbidity, of improved correction of acidosis in the first year of treatment with continuous ambulatory peritoneal dialysis (CAPD). Two hundred consecutive new CAPD patients were randomized, in a single-blind fashion, to receive a high (HA; lactate 40 mmol/liter) or low (LA; lactate 35 mmol/liter) alkali dialysate for one year. Calcium carbonate and sodium bicarbonate were also used to correct acidosis in the HA group. At one year, the venous serum bicarbonate and arterial pH were 7.44 +/- 0.004 and 27.2 +/- 0.3 mmol/liter in the HA group, and 23.0 +/- 0.3 mmol/liter and 7.4 +/- 0.004 in the LA group (P < 0.001). Dialysis dose, at one year or at the point of leaving the study (HA 8.0 +/- 0.1 liters/day vs. LA 8.5 +/- 0.3 liters/day) was not significantly different (P = 0.18). At one year, the increase in body weight in the HA group (6.1 +/- 0.66 kg) was higher than in the LA group (3.71 +/- 0.56 kg, P < 0.05). The increase in midarm circumference in the HA patients (1.26 +/- 0.16 cm) was significantly higher than the increase in the LA patients (0.61 +/- 0.16 cm, P < 0.05). The increase in triceps skinfold thickness were not significantly different (HA 2.5 +/- 0.41 mm vs. LA 1.24 +/- 0.38 mm, P = 0.1). Serum albumin was 37.8 +/- 0.4 g/dl at one year in the HA group, and 38.2 +/- 0.5 g/dl in the LA group (NS). Dietary protein intake at one year (HA 0.9 +/- 0.2 g/kg/day vs. LA 1.0 +/- 0.1 g/kg/day) was not significantly different. There were fewer hospital admissions in the HA group (1.13 +/- 0.16 per patient per year) compared to the LA group (1.71 +/- 0.22 per patient per year, P < 0.05). The HA patients spent less days in hospital per year than the LA patients (16.4 +/- 1.4 days/year vs. 21.2 +/- 1.9 days/year; P < 0.05). It is concluded that better correction of metabolic acidosis leads to greater increases in body weight and midarm circumference, but not triceps skinfold thickness, in the first year of CAPD. The improvement in morbidity, in terms of number of admissions and days in hospital per year, may be associated with the improvement in nutritional state.

Expression of the receptor for parathyroid hormone-related protein in normal and malignant breast tissue

Parathyroid hormone-related protein (PTHrP) is the cause of humoral hypercalcaemia of malignancy and interacts with parathyroid hormone (PTH) receptors. Breast cancer cells produce PTHrP in vitro and in vivo. The breast cancer cell line MCF-7, which products PTHrP and expresses PTHrP receptors, proliferates in response to PTHrP. The aim of these studies was to determine the tissue location of PTHrP/PTH receptors (PTHrPR) in primary breast carcinomas and to establish whether they had the potential to respond to PTHrP. The cellular location of mRNA for the PTHrP/PTH receptor was identified using in situ hybridization in primary breast carcinomas and normal breast tissue. Immunohistochemistry for PTHrP was carried out on the same specimens. Tumours were assessed and scored by two observers using the product of intensity of signal and number of positive tumour cells (possible range 0-9). Tumours were also assessed for Ki-67 expression by counting positive nuclei. Non-malignant ductular epithelium expressed mRNA for the PTHrP receptor (mean score 2.6, range 1-4). Breast carcinomas (mean score 4.4, range 0-9) showed variable expression of PTHrP receptor mRNA: eight tumours were negative, 50 had scores similar to normal breast tissue, and 49 had higher scores for the receptor. Levels of expression of the receptor within the primary breast carcinomas were unrelated to immunohistochemical detection of PTHrP or to any standard prognostic factor. There was a significant (P = 0.05) relationship between Ki-67 and PTHrPR expression in individual tumours. The presence of PTHrP and its receptor in normal breast epithelium and breast carcinomas demonstrates that most breast tumours are able to respond to PTHrP. The Ki-67 data suggest that PTHrP is a potential autocrine growth factor in primary breast carcinoma.

D-penicillamine reduces renal injury in the remnant model of chronic renal failure in the rat

BACKGROUND

Glomerulosclerosis and interstitial fibrosis, which are cardinal features of the end-stage kidney, result from accumulation of extracellular matrix proteins, particularly collagen, in the glomerular mesangium and renal interstitium. This study examined the effect of D-penicillamine (DPC), which inhibits collagen deposition, on disease progression in the remnant kidney.

METHODS

Two groups of 10 rats underwent two-thirds nephrectomy and were pair-fed 20% casein paste (Gp 1) or the same paste supplemented with 90 mg/kg body wt per day of DPC (Gp 2). Two further groups of five non-nephrectomized animals also received 20% casein paste either alone (Gp 3) or supplemented with DPC (Gp 4). In a further experiment, systolic blood pressure was compared at 1 and 4 weeks after nephrectomy in eight DPC-treated remnants and eight untreated controls.

RESULTS

Gp 2 developed significantly less proteinuria than Gp 1 (41 +/- 9 vs 142 +/- 33 mg/24 h at 6 weeks, P < 0.005; 136 +/- 36 vs 282 +/- 59 mg/24 h at 12 weeks, P < 0.05). At sacrifice after 12 weeks, glomerular filtration rates were higher (1.34 +/- 0.08 vs 1.07 +/- 0.1 ml/min, P < 0.05), kidney total collagen content was lower (14.9 +/- 1.5 vs 26.9 +/- 5.4 mg/kidney, P < 0.05) and glomerular abnormalities, interstitial fibrosis and lymphocytic infiltration were less marked in Gp 2 compared with Gp 1. DPC had no effect on protein excretion, total kidney collagen or GFR in non-nephrectomized rats, and did not influence the early rise in blood pressure seen after two-thirds nephrectomy.

CONCLUSIONS

These findings demonstrate that DPC reduces renal injury in the remnant kidney, and raise the possibility of a therapeutic role for DPC in the treatment of patients with chronic renal failure.

Hypoxia induces intercellular adhesion molecule-1 on cultured human tubular cells

The adverse effects of acute renal ischemia are partly mediated through an infiltration of inflammatory cells into the tubulointerstitium. The expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) by resident renal cells (endothelial cells and tubular cells) may facilitate this process. We investigated whether hypoxia stimulates the expression of ICAM-1 by cultured human proximal tubular cells (HPTC). Hypoxic culture conditions (PO2 < 4 kPa) stimulated the expression of ICAM-1 by HPTC in a time-dependent manner (P < 0.0001) as demonstrated by quantitative flow cytometry analysis. Quantitative PCR demonstrated an increase in ICAM-1 transcription. Re-oxygenation of tubular cells did not increase ICAM-1 expression further. TNF alpha concentration in culture supernatants increased with hypoxia, but blocking experiments demonstrated that TNF alpha was not implicated in hypoxia-induced expression of ICAM-1. Furthermore, the cytokines IL-6 and IL-1 beta were not involved, but the effect of hypoxia was blocked by PDTC, an antioxidant that may inhibit the activation of the transcription factor NF-kappa B. These data demonstrate that hypoxia is a stimulus that induces the synthesis and expression of the adhesion molecule ICAM-1, presumably via the activation of NF-kappa B.

Erythropoietin and sexual dysfunction

BACKGROUND

Erythropoietin (rHuEpo) therapy has been shown to improve sexual function in the male dialysis population, with several studies suggesting a direct effect upon endocrine function, as well as correction of anaemia. Nevertheless many male dialysis patients receiving rHuEpo continue to complain of sexual dysfunction.

METHODS

At a dedicated renal impotence clinic, 65 male dialysis patients were screened for endocrine disturbances. Baseline serum sex hormones were compared between those receiving and not receiving rHuEpo, using either the two-sample t test or the Mann-Whitney U test, after assessing for normality. Results from four patients were excluded on account of either medications (antiemetic phenothiazines), hepatic dysfunction, or carcinomatosis.

RESULTS

Twenty-five patients (41.0%) were receiving rHuEpo, the recipients and non-recipients being well matched for haemoglobin (10.19 +/- 0.29 vs 10.55 +/- 0.25 g/dl, n.s.), age (51.1 +/- 1.9 vs 53.6 +/- 2.1 years, n.s.) and duration of sexual dysfunction (median, 3.0 vs 3.0 years, n.s.). The rHuEpo recipients had a higher median creatinine (1090 vs 972 micromol/l, P < 0.02), but similar nutritional status to the non-recipients (albumin 41.0 vs 39.0 g/l, n.s.). The total duration of rHuEpo therapy was 0.85 +/- 0.14 years. Prolactin levels were similar in both the rHuEpo recipients and non-recipients (440 vs 541 mu/l, n.s.), as were LH (11.0 vs 10.5 iu/l, n.s.) and FSH (8.0 vs 6.5 iu/l, n.s.). However, there were significant elevations of testosterone (19.8 +/- 1.3 vs 16.1 +/- 1.1 nmol/l, P < 0.05) and sex hormone binding globulin (SHBG) (40.5 vs 26.0 nmol/l, P < 0.01), with a trend toward elevated oestradiol (304 vs 248 pmol/l, P = 0.095) in the rHuEpo-treated group. Forty-eight subjects (78.7%) received peritoneal dialysis (PD), with the 19 rHuEpo recipients (39.6%) demonstrating increased serum testosterone (21.0 +/- 1.5 vs 16.6 +/- 1.3 nmol/l, P < 0.05), SHBG (40.5 vs 26.5 nmol/l, P < 0.01), LH (15.0 vs 10.0 iu/l, P < 0.01) and FSH (12.0 vs 5.3 iu/l, P < 0.05). These differences were not demonstrated in the 13 haemodialysis (HD) subjects.

CONCLUSIONS

Male dialysis patients complaining of sexual dysfunction after correction of anaemia with rHuEpo are characterized by higher levels of serum testosterone and SHBG, but not suppression of hyperprolactinaemia or hyperoestrogenism. Male PD subjects receiving rHuEpo also demonstrated increased LH and FSH.

Characteristics of albumin binding to opossum kidney cells and identification of potential receptors

Albumin re-absorption in the kidney proximal tubule may be pathophysiological in disease. Opossum kidney (OK) cell monolayers were used to investigate the characteristics of [125I]-labelled albumin binding at 4 degrees C. Two binding sites were identified, one with high affinity (KD 154.8 +/-7 mg/l) and low capacity, the other with low affinity (KD 8300 +/- 1000 mg/l) and high capacity. Binding was sensitive to lectins Glycine max and Ulex europaeus I, but not other lectins, indicating involvement of a glycoprotein(s) in the binding process. Binding was also sensitive to a number of agents known to inhibit binding to scavenger receptors. [125I]-Labelled albumin ligand blotting of OK cell membrane proteins identified several albumin-binding proteins with identical lectin affinities to those proteins mediating albumin binding to OK cell monolayers. These results provide initial evidence of the identity of albumin receptors in kidney tubules, and suggest that they may be members of the family of scavenger receptors.

Effect of correction of acidosis on nutritional status in dialysis patients

Malnutrition is a well-recognised feature of end-stage renal failure and contributes to the continuing high morbidity and mortality in this group of patients. One of the aetiological factors is metabolic acidosis which has been shown to increase protein degradation in both experimental models of chronic renal failure and in humans with uraemia. Many patients currently receiving haemodialysis have subnormal values of plasma bicarbonate. However, the values can be normalised by using a dialysate bicarbonate concentration of 35-40 mmol/l and in continuous ambulatory peritoneal dialysis (CAPD), a similar increment in plasma bicarbonate can be achieved using a dialysate lactate content of 35-40 mmol/l. In short-term studies in haemodialysis patients there is evidence of an increase in body weight and other anthroprometric parameters when the plasma bicarbonate has been normalised by increasing the dialysate bicarbonate content. A long-term study in CAPD patients has demonstrated increased body weight, tricep skinfold thickness and midarm muscle circumference in those patients with a plasma bicarbonate of 27.2 +/- 0.3 mmol/l, compared to those with a value of 23.0 +/- 0.3 mmol/l. These studies strongly suggest that correction of acidosis by increased dialysate buffering capacity will improve nutritional status for patients with end-stage renal failure.

Dose-response study of ibandronate in the treatment of cancer-associated hypercalcaemia

Hypercalcaemia is an important cause of morbidity in malignant disease. We studied the efficacy and safety of intravenous ibandronate (a new, potent bisphosphonate) in a multicentre study of 147 patients with severe cancer-associated hypercalcaemia which had been resistant to treatment with rehydration alone. Of 131 randomized patients who were eligible for evaluation, 45 were allocated to receive 2 mg ibandronate, 44 patients to receive 4 mg and 42 patients to receive 6 mg. Serum calcium values fell progressively in each group from day 2, reaching a nadir at day 5, and in some patients normocalcaemia was maintained for up to 36 days after treatment. The 2-mg dose was significantly less effective than the 4-mg or 6-mg dose in correcting hypercalcaemia, as the number of patients who achieved serum calcium values below 2.7 mM after treatment was 50% in the 2-mg group compared with 75.6% in the 4-mg group and 77.4% in the 6-mg group (P < 0.05; 2 mg vs others). In a logistic regression analysis, three factors were found to predict response; ibandronate dose (higher doses were more effective), severity of presenting hypercalcaemia (severe hypercalcaemia was associated with less complete response) and tumour type (patients with breast carcinoma and haematological tumours responded better than those with other tumours). Ibandronate was generally well tolerated and no serious drug-related adverse events were observed. We conclude that ibandronate is a safe, well tolerated and effective treatment for cancer-associated hypercalcaemia, which should prove a useful addition to the current range of therapies available to treat this condition.

Serum 1,25-dihydroxyvitamin D may be related inversely to disease activity in breast cancer patients with bone metastases

1,25-dihydroxyvitamin D (1,25-(OH)2D) stimulates differentiation and controls proliferation in breast cancer cells. The role of endogenous 1,25-(OH)2D and its relation to PTH related protein (PTHrP) during the progression of breast cancer is not known; we therefore investigated these hormones in two studies. In a cross-sectional study of patients with breast cancer at different stages of disease, serum 1,25-(OH)2D levels (mean +/- SE) were highest in early disease (102 +/- 3.7 pmol/L), fell in normocalemic patients with bone metastases (52 +/- 5.3 pmol/L; P < 0.01), and were lowest in hypercalcemic patients (33 +/- 5.6 pmol/L; P < 0.001). PTHrP was detectable in the serum of only one normocalcemic patient with progressive metastases but was present in 11 of the 12 hypercalcemic patients, thus PTHrP did not stimulate 1,25-(OH)2D synthesis. In a 6-month longitudinal study of normocalcemic patients with bone metastases undergoing hormonal therapy, serum 1,25-(OH)2D concentrations fell in patients whose disease progressed (P = 0.0056), but remained constant in those who were stable or responded to treatment. These changes in 1,25-(OH)2D preceded clinical signs of progression and predicted disease response. In the progressive group, five of whom died during the study, 1,25-(OH)2D decreased between the initial and final samples, PTH fell significantly from 24.8 to 13.5 ng/L (P = 0.025), serum calcium rose from 2.27 to 2.39 mmol/L (P = 0.017), and the urinary calcium/creatinine ratio rose from 0.37 to 0.68 (P = 0.046). PTH and 1,25-(OH)2D were significantly correlated in the final samples from this group, Spearman's rank correlation = 0.80, P = 0.022. The results indicate that normocalcemia in these patients is maintained, at the expense of suppressing PTH and 1,25-(OH)2D, in the face of increased calcium released from lytic lesions in bone. Loss of the antiproliferative effects of 1,25-(OH)2D may then permit more rapid secondary growth of the tumor.

Cyclosporin A and multiple fibroadenomas of the breast

Multiple bilateral fibroadenomas are uncommon. This finding in four women who had received renal transplants prompted further inquiry. A prospective study was performed on 39 women under the age of 55 years who had received a renal transplant at least 1 year earlier. Clinical examination and breast ultrasonography were performed. Factors considered included immunosuppressive therapy, concurrent medication and renal function. Blood was taken for estimation of oestradiol, prolactin, follicle-stimulating hormone (FSH) and sex hormone binding globulin levels. Fibroadenomas were found in 13 of 29 women who had received cyclosporin A: multiple in ten and bilateral in five. No abnormal breast findings were seen in 10 patients immunosuppressed with steroids and azathioprine alone (chi 2 = 7.30, 1 d.f., P < 0.01). Serum oestradiol concentration was raised in women with fibroadenomas compared with that in those with normal breasts (P < 0.05) and the level of FSH was lower (P < 0.01). Cyclosporin A may act on breast fibroblasts by humoral mechanisms and direct action.

A comparison of axillary node status between cancers detected at the prevalence and first incidence breast screening rounds

Screen-detected breast cancers are smaller than those detected in symptomatic populations and, for any given size, they are associated with fewer lymph node metastases. The management of axillary lymph nodes in patients with screen-detected breast cancer remains controversial. We have previously reported that prevalence (initial screen)-detected cancers are associated with nodal metastases in 17.4% of cases overall. Cancers < or = 10 mm, of any grade, are associated with metastases in only 5% of cases, and grade I cancers <30 mm are not associated with metastases. This led to our recommendation that axillary surgery is unnecessary for these groups of women. The present study compared the nodal status of cancers detected at the prevalence and first incidence (second) screens in order to determine whether our recommendation is appropriate for cancers detected at the first incidence screen. Overall, 30.1% of cancers detected in the first incidence screen presented axillary nodal metastases. At all size ranges, cancers detected at the first incidence screen were associated with significantly more lymph node metastases than prevalence-detected cancers. In particular, cancers < or = 10 mm were associated with metastases in 14.3% of cases. With the possible exception of grade I cancers, we believe that surgical staging of the axilla is essential for cancers detected at the first incidence screen, irrespective of size.