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C G J Sweep

Publications and source records attributed to C G J Sweep.

At least 19 recordsLinked to original sources

Virilization due to ovarian androgen hypersecretion in a patient with ectopic adrenocorticotrophic hormone secretion caused by a carcinoid tumour: case report.

A 52-year-old woman presented with symptoms of virilization, which had been ongoing for 5 months. At the age of 34 years, she had a large abdominal carcinoid tumour removed. Twelve years later, she presented with Cushing's syndrome due to ectopic adrenocorticotrophic hormone (ACTH) production by carcinoid metastases localized in the right parametrium, fornix posterior and right diaphragm. Debulking laparotomy was performed followed by remission of hypercortisolism. Relapse of hypercortisolism followed 3 years later, and a second debulking laparotomy was performed including resection of the right ovary. In the following year, relapses of hypercortisolism were observed until bilateral adrenalectomy was performed. Laboratory evaluation revealed elevated serum levels of testosterone (23.0 nmol/l), androstenedione and 17-hydroxyprogesterone, and a serum estradiol (E2) level in the premenopausal range. The computerized tomography (CT) of the abdomen showed a large pelvic mass on the left side of the uterus without a recognizable left ovary. Treatment with a GnRH agonist (goserelin, 3.6 mg s.c., monthly) was initiated, resulting in normalization of the androgen levels. One year later, obstruction of the right ureter occurred due to progression of the pelvic metastases, thus a third debulking laparotomy with resection of the pelvic metastases including the left ovary was performed. The microscopic examination of the removed pelvic mass showed malignant carcinoid tissue with focal remnants of atrophic ovarian tissue. Two years after surgery, serum androgen levels are undetectable. We hypothesize that the high levels of ACTH at the site of the left ovary have induced androgen hypersecretion by steroid-producing cells in the ovary of our patient.

Adrenocortical Hyperfunction↗

Sperm integrity pre- and post-chemotherapy in men with testicular germ cell cancer.

BACKGROUND: While (partial) recovery of spermatogenesis, observed by means of standard semen analysis, has been seen in testicular cancer patients after chemotherapy with cisplatin, sperm genomic integrity and its implication for the patient's fertility are poorly understood. METHODS: Semen and serum from 22 patients treated for testicular cancer were analysed pre- and post-chemotherapy. Besides routine semen analysis, sperm samples were evaluated by computerized karyometric image analysis (CKIA), chromomycin-A3 assay (CMA3, chromatin condensation) and TdT-mediated dUTP nick-end labelling assay (TUNEL, DNA damage). Serum FSH, LH and testosterone concentrations were measured. RESULTS: Ejaculate volume decreased post-chemotherapy (P<0.05). External sperm characteristics (CKIA morphometry) and sperm counts did not deteriorate after chemotherapy. An improvement in DNA condensation was assessed after chemotherapy (37 versus 50% and 47.5 versus 63.7% for CMA3 and CKIA respectively; both P<0.005); yet a high percentage of TUNEL-positive sperm was found in the samples (21 versus 25% for pre- and post-chemotherapy samples respectively). These values were significantly higher than those of a convenience sample of normozoospermic males attending pre-IVF screening. Serum FSH and LH (IU/l) increased after chemotherapy compared with pretreatment levels (8.1 versus 16.7 and 4.5 vs 6.8; both P<0.05, respectively). CONCLUSIONS: Despite the improvement in sperm chromatin packaging after chemotherapy, an abnormally high percentage of DNA-damaged sperm was found in these samples. As sperm quality does not reach normal levels after treatment, it remains difficult to outline the best strategy and guidance concerning fertility potential of testicular cancer patients.

Adult↗

A patient with recurrent hypercortisolism after removal of an ACTH-secreting pituitary adenoma due to an adrenal macronodule.

A 41-yr-old female was referred for signs and symptoms of Cushing's syndrome. Cortisol was not suppressed by 1 mg dexamethasone (0.41 micromol/l). Midnight cortisol and ACTH were 0.44 micromol/l and 18 pmol/l, respectively. Urinary cortisol excretion was 250 nmol/24 h (normal between 30 and 150 nmol/24 h). A magnetic resonance imaging (MRI) revealed a pituitary lesion of 7 mm. ACTH and cortisol levels were unaltered by administration of human CRH and high-dose dexamethasone. Inferior sinus petrosus sampling showed CRH-stimulated ACTH levels of 128.4 (left sinus) vs a peripheral level of 19.2 pmol/l, indicating Cushing's disease. After 4 months of pre-treatment with metyrapone and dexamethasone, endoscopic transsphenoidal resection of an ACTH-positive pituitary adenoma was performed. ACTH levels decreased to 2.6 pmol/l and fasting cortisol was 0.35 micromol/l. Despite clinical regression of Cushing's syndrome and normalization of urinary cortisol, cortisol was not suppressed by 1 mg dexamethasone (0.30 micromol/l). Ten months post-operatively, signs and symptoms of Cushing's syndrome reoccurred. A high dose dexamethasone test according to Liddle resulted in undetectable ACTH, but no suppression of cortisol levels, pointing towards adrenal-dependent Cushing's syndrome. Computed tomography (CT)-scanning showed a left-sided adrenal macronodule. Laparoscopic left adrenalectomy revealed a cortical macronodule (3.5 cm) surrounded by micronodular hyperplasia. Fasting cortisol had decreased to 0.02 micromol/l. Glucocorticoid suppletion was started and tapered over 12 months. Symptoms and signs of hypercortisolism gradually disappeared. This case illustrates, that longstanding ACTH stimulation by a pituitary adenoma can induce unilateral macronodular adrenal hyperplasia with autonomous cortisol production.

ACTH-Secreting Pituitary Adenoma↗

Forearm vasoconstrictor response in uncomplicated type 1 diabetes mellitus.

BACKGROUND: According to the 'haemodynamic hypothesis', increased tissue perfusion predisposes to microangiopathy in diabetic patients. We hypothesized that the typical haemodynamic changes underlying the increased tissue perfusion can be explained by a decreased sympathetic nerve activity caused by chronic hyperglycaemia. In this study we investigated sympathetic activity in patients with uncomplicated type 1 diabetes mellitus (DM). MATERIALS AND METHODS: In 15 DM patients (DM duration 6.3 +/- 3.8 year; HbA1c 7.9 +/- 1.3%) and 16 age- and sex-matched healthy volunteers (Control), sympathetic nervous system activity was measured at rest (baseline) and during sympathoneural stimulation (lower body negative pressure (LBNP)) by means of interstitial and plasma noradrenaline (NA) sampling and power spectral analysis. Muscle sympathetic nerve activity (MSNA) was measured before (baseline) and during a cold pressure test. Forearm blood flow was measured during forearm vascular alpha- and beta-adrenergic receptor blockade. RESULTS: At baseline, forearm vascular resistance (FVR), plasma NA concentrations, MSNA and heart rate variability were similar in both groups. LBNP-induced vasoconstriction was significantly attenuated in the DM group compared with the Control group (DeltaFVR: 12 +/- 4 vs. 19 +/- 3 arbitrary units, P < 0.05). The responses of plasma NA and heart rate variability did not differ. CONCLUSIONS: Baseline FVR and sympathetic nerve activity are normal in patients with uncomplicated type 1 diabetes. However, the forearm vasoconstrictor response to sympathetic stimulation is attenuated, which cannot be attributed to an impaired sympathetic responsiveness.

Adrenergic Antagonists↗

Fertility in patients with congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is generally regarded as a paediatric endocrine disease, but nowadays nearly all patients reach adulthood as a result of improved diagnosis and treatment. It is now increasingly recognised that treatment goals shift during life: one of the major treatment goals in childhood and puberty, i.e. normal growth and development, is no longer relevant after childhood, whereas other aspects, such as fertility and side effects of long-term glucocorticoid treatment, become more important in adulthood. This paper focuses on fertility in male and female adult patients with CAH. In males with CAH the fertility rate is reduced compared with the normal population, the most frequent cause being testicular adrenal rest tumours. Development and growth of these tumours is assumed to be ACTH dependent and undertreatment may play an important role. If intensifying glucocorticoid treatment does not lead to tumour decrease, surgical intervention may be considered, but the effect on fertility is not yet known. In females with CAH the degree of fertility depends on the phenotype of the CAH. Most fertility problems are seen in the classic salt-wasting type. Age of menarche and regularity of the menstrual cycle depends on the degree of adrenal suppression. Not only adrenal androgens have to be normalised but also the levels of adrenal progestins (progesterone and 17-OH-progesterone) that interfere with normal ovulatory cycles. The regularity of menstrual cycles can be considered as an important measure of therapeutic control in adolescent females with CAH and therefore as a therapeutic goal from (peri)pubertal years on. Other factors that contribute to impaired fertility in females with CAH are ovarian hyperandrogenism (polycystic ovary syndrome), ovarian adrenal rest tumours, genital surgery and psychological factors. Subfertility in CAH can have its origin already in the peripubertal years and is therefore of interest to the paediatric endocrinologist.

Adrenal Hyperplasia, Congenital↗

Transsphenoidal pituitary surgery via the endoscopic technique: results in 35 consecutive patients with Cushing's disease.

OBJECTIVE AND DESIGN: The endoscopic technique has been recently introduced in the field of transsphenoidal pituitary surgery. This technique allows inspection of sellar, supra- and parasellar structures and removal of the tumor under direct visualization, is minimally traumatic and permits easier reoperations. This is the first report on the results of endoscopic surgery for patients with Cushing's disease. Our aim was to retrospectively analyze the results of pituitary surgery in 35 consecutive patients with Cushing's disease operated in our hospital after the introduction of the endoscopic technique (1998-2004). METHODS: Remission was defined as suppression of plasma cortisol (< or =50 nmol/L) after 1 mg dexamethasone overnight determined in the first 3 months after surgery and disappearance of clinical signs and symptoms of hypercortisolism. The patients were followed for an average of 27 months (range 4 to 81 months, median 20 months). RESULTS: Pituitary MRI showed a macroadenoma in 6 patients, a microadenoma in 17 patients and no adenoma in 12 patients. After the initial surgery 27 patients (77%) were in remission. None of the patients had a relapse during follow-up. In the remaining 8 patients hypercortisolemia persisted after surgery. Three of them had a second endoscopic pituitary surgery resulting in remission in two patients. In one patient a second endoscopic pituitary surgery will soon follow. The remaining four patients were treated with radiotherapy postoperatively. Two of them were at the time of data collection in remission. One patient from the remission group had a serious epistaxis and three patients had cerebrospinal fluid leakage, one requiring an external lumbar drain, shortly after surgery. No complications were recorded in the failure group. Postoperatively 34% of all patients required substitution with levothyroxine, 40% required substitution with glucocorticoids, 17% received estrogens or testosterone and 6% still required desmopressin. CONCLUSIONS: Endoscopic transsphenoidal pituitary surgery resulted in our series of patients with Cushings disease in an excellent postoperative remission rate. A randomized clinical trial, comparing endoscopic and conventional pituitary surgery in patients with Cushings disease, is needed to determine the pros and cons of both techniques.

ACTH-Secreting Pituitary Adenoma↗

Stress and outcome success in IVF: the role of self-reports and endocrine variables.

BACKGROUND: The aim of this study was to examine the associations between urinary levels of the stress hormones adrenaline, noradrenaline and cortisol during treatment with self reported stress, in order to investigate the mechanism for the previously observed negative association of anxiety and depression with the outcome of IVF/ICSI. METHODS: In a multicentre prospective cohort study, women entering their first cycle of IVF/ICSI treatment were asked to participate. From each participant nocturnal urine samples were collected; pre-treatment, before oocyte retrieval and before embryo-transfer (ET), to assess hormonal concentrations. Additionally, two questionnaires were administered before the start of the treatment to measure anxiety and depression. RESULTS: 168 women completed the questionnaires and collected at least two urine specimens. A significant positive correlation between urinary adrenaline concentrations at baseline and ET and the scores on depression at baseline were found. In women with successful treatment, lower concentrations of adrenaline at oocyte retrieval and lower concentrations of adrenaline and noradrenaline at ET, compared with unsuccessful women, were found. CONCLUSIONS: The significant positive association of adrenaline concentration with pregnancy and with depression suggested that this adrenal hormone could be one of the links in the complex relationship between psychosocial stress and outcome after IVF/ICSI.

Adult↗

Measurement of plasminogen activator system components in plasma and tumor tissue extracts obtained from patients with breast cancer: an EORTC Receptor and Biomarker Group collaboration.

The plasminogen activator (PA) system comprises the 2 serine proteases, urokinase PA (uPA) and tissue PA (tPA), the 2 serpin inhibitors, PAI-1 and PAI-2 and the uPA receptor (uPAR; CD87). High levels of uPA, PAI-1, uPA-PAI-1 complex and uPAR in breast cancer tissue are associated with poor prognosis, while high levels of tPA or PAI-2 correlate with good prognosis. In this study, pre-operative plasma levels of uPA, PAI-1, uPAR, tPA, uPA-PAI-1 complex, and tPA-PAI-1 complex were measured in patients with benign (n=103) and malignant breast disease (n=113) by immunoenzymatic assays (ELISA). While plasma antigen levels of uPA, PAI-1, uPA-PAI-1 complex and uPAR were not significantly different in the 2 groups, antigen levels of tPA and tPA-PAI-1 complex were significantly higher in patients with breast carcinoma compared to the control group. In plasma from the breast cancer patients, uPA levels correlated weakly but significantly with those of tPA (r=0.20, p=0.035) and uPAR (r=0.208, p=0.028). tPA levels correlated strongly with tPA-PAI-1 complex (r=0.972, p=0.0001) while uPA-PAI-1 levels were significantly associated with PAI-1 levels (r=0.534, p<0.0001), tPA levels (r=0.348, p=0.0003) and tPA-PAI-1 levels (r=0.356, p=0.002). However, no significant correlation was found between plasma and tumor tissue levels of uPA, PAI-1, uPA-PAI-1 complex, tPA or tPA-PAI-1. Our findings indicate that determination of these factors in plasma do not reflect their concentration in tumor tissue. Therefore, measurement of PA components in blood cannot be recommended for assessing prognosis in breast cancer.

Biomarkers, Tumor↗

Expression and localisation of the new metalloproteinase inhibitor RECK (reversion inducing cysteine-rich protein with Kazal motifs) in inflamed synovial membranes of patients with rheumatoid arthritis.

OBJECTIVE: To assess the expression and localisation of the new metalloproteinase inhibitor RECK, an inhibitor of matrix metalloproteinase-14 (MMP-14) secretion and activity, in the synovial membrane of patients with rheumatoid arthritis (RA). METHODS: RECK expression in synovium samples from patients with RA, osteoarthritis (OA), and "trauma" were studied by quantitative real time reverse transcription-polymerase chain reaction (Q-PCR). RECK mRNA levels were compared with those of the enzyme MMP-14. RECK expression on cryostat sections of synovium was disclosed by goat-antihuman RECK monoclonal antibody. RECK protein was detected on synovial cryostat sections and measured by western blotting. RECK expression on macrophages was investigated by double staining of CD68 and RECK on cryostat sections and characterised by confocal microscopy. RECK expression on RA monocytes or normal monocytes was further investigated by FACS analysis. RESULTS: RECK expression in the synovial membrane of patients with RA was significantly lower than in OA and controls. MMP-14 mRNA levels were not significantly different between the three groups. In RA synovium, RECK protein was expressed mainly in the lining layer but also by macrophages around blood vessels. Fibroblasts and about 50% of the CD68 positive macrophages expressed RECK. In CD68 positive macrophages, RECK was only expressed in secretory granules and not on the membrane. The same pattern was found in M-CSF cultured macrophages of patients with RA and controls. In contrast, synovial fibroblasts showed a diffuse membrane expression within the synovium similar to cultured RA fibroblasts. RECK expression was low on the membrane of monocytes according to FACS analysis. CONCLUSION: The new MMP inhibitor RECK is expressed in synovial membranes of RA, OA, and controls. RECK mRNA is lowest in RA synovial membranes. In contrast with fibroblasts, macrophages in the synovium express RECK only cytoplasmically and not on their membrane.

Arthritis, Rheumatoid↗

Decreased prolactin response to hypoglycaemia in patients with rheumatoid arthritis: correlation with disease activity.

OBJECTIVE: To compare basal and stimulated prolactin levels between patients with rheumatoid arthritis and healthy controls, and to assess the effects of antirheumatic treatment on prolactin concentrations. METHODS: Serum prolactin was assessed under basal conditions and during an insulin tolerance test (ITT) in 20 patients with recently diagnosed active rheumatoid arthritis and 20 age and sex matched controls. The patients were reassessed after two weeks' treatment with naproxen and after six months' additional treatment with either sulfasalazine or methotrexate. Disease activity was assessed by the disease activity score (DAS). RESULTS: Basal levels of prolactin were not significantly different between patients with rheumatoid arthritis and controls. Prolactin responses to hypoglycaemia were less in untreated rheumatoid patients than in controls. DAS scores correlated negatively with the area under the curve (AUC) for prolactin concentrations during the ITT. Treatment with naproxen for two weeks did not influence either basal or stimulated prolactin levels. After six months of antirheumatic treatment, prolactin responses to hypoglycaemia increased significantly to levels observed in controls. At the same time point, DAS had improved considerably. The improvement correlated with the increase in AUC of prolactin during the ITT (r = 0.48; p = 0.05). CONCLUSIONS: Patients with active rheumatoid arthritis have a decreased prolactin response to hypoglycaemia induced stress. The response recovers following treatment with antirheumatic drugs.

Adult↗

Metabolic profile of the hippocampus of Zucker Diabetic Fatty rats assessed by in vivo 1H magnetic resonance spectroscopy.

Localized in vivo 1H magnetic resonance spectroscopy (MRS) was used to investigate metabolite levels in the brain of adult Zucker Diabetic Fatty (ZDF) rats, an animal model for type 2 diabetes mellitus. This study focussed on the hippocampus, assumed to be one of the main brain areas affected by this disease. Together with an almost 5-fold increase in blood glucose concentration measured by glucose oxidation, significant increases were found in the hippocampal concentrations of glucose (4.93 vs 1.66 mM p < 0.001), myo-inositol (6.52 vs 4.30 mM; p < 0.05), and total creatine (12.71 vs 10.50 mM; p < 0.05) in ZDF rats (n = 5) compared with littermates (n = 5). Although no obvious alterations were detected in the hippocampal levels of other metabolites, including NAA + NAAG and choline-containing compounds in the ZDF rats, the increase in Glc and Ins levels is in line with elevated brain tissue contents of these metabolites in patients with diabetes mellitus.

Animals↗

Tissue inhibitors of metalloproteinase expression in human breast cancer: TIMP-3 is associated with adjuvant endocrine therapy success.

Tissue inhibitors of matrix metalloproteinase (TIMPs) may be involved in tumour growth, apoptosis, angiogenesis, invasion, and the development of metastases. This study has evaluated the association of the expression levels of the TIMP forms 1, 2, 3, and 4, measured by quantitative real-time RT-PCR, with classical clinicopathological characteristics, ie age, menopausal status, tumour size, histological grade, number of involved lymph nodes, and steroid hormone receptor status, and with disease progression and treatment sensitivity in 273 breast cancer patients. The mRNA levels of TIMP-1 and TIMP-2 were not associated with any known clinicopathological tumour feature. TIMP-3 and TIMP-4 levels were significantly higher in steroid hormone receptor-positive samples, although the levels of TIMP-4 were much lower than those of the other TIMPs. Only TIMP-3 predicted relapse-free survival (RFS) time differently depending on post-surgical treatment as, in particular, the interaction of TIMP-3 with endocrine therapy (p = 0.008, HR = 0.24, 95% CI = 0.09-0.69) contributed significantly to RFS in multivariate Cox regression analysis. In subgroup analyses, the 107 patients treated with tamoxifen differed greatly in prognosis after dichotomization by the median TIMP-3 level (p = 0.0003). Thus, high tumour levels of the matrix metalloproteinases inhibitor and pro-apoptotic factor TIMP-3 are associated with successful tamoxifen treatment of patients with breast cancer.

Adult↗

Percutaneous epididymal sperm aspiration: a diagnostic tool for the prediction of complete spermatogenesis.

The classification of azoospermia into obstructive or non-obstructive is largely based on medical history, physical examination and biochemical markers in serum and semen. However, the most accurate parameter for diagnosis is the testicular histology. The predictive value of the percutaneous epididymal sperm aspiration (PESA), FSH, LH, testosterone, inhibin-B and testicular volume was investigated for their accuracy to predict a complete spermatogenesis (Johnsen score > or =8) in order to replace the testicular histology. The specificity and sensitivity of FSH, inhibin-B, LH, testosterone, testicular volume, and the presence of sperm in a PESA procedure was evaluated in 147 azoospermic males attending the centre for infertility diagnosis. A positive PESA outcome presented the highest sensitivity and specificity to predict a Johnsen score > or =8 (93 and 94% respectively) compared with FSH (90 and 19%), inhibin-B (88 and 57%) and testicular volume (95 and 45%). Differences in clinical presentation were observed between patients with positive sperm retrieval with PESA, depending on the aetiology of obstruction. In conclusion, the presence of spermatozoa in the epididymis (PESA+) correlates with a Johnsen score > or =8 and is the most accurate parameter to predict complete spermatogenesis compared with clinical or biochemical parameters. Between obstructive azoospermic patients, the clinical parameters observed varied according to the aetiology.

Biopsy, Needle↗

Role of hexosamines in insulin resistance and nutrient sensing in human adipose and muscle tissue.

It has been proposed that the hexosamine pathway acts as a nutrient-sensing pathway, protecting the cell against abundant fuel supply, and that accumulation of hexosamines represents a biochemical mechanism by which hyperglycemia and hyperlipidemia induce insulin resistance. We hypothesized that if an increased flux through the hexosamine pathway caused insulin resistance in humans, the hexosamine levels should be increased in adipose and/or muscle tissue in insulin-resistant subjects, such as patients with type 2 diabetes and obese individuals. In addition, we reasoned that if the hexosamine pathway were a nutrient-sensing pathway, hexosamine levels in adipose and skeletal muscle tissue should be correlated with levels of circulating nutrients, such as glucose and free fatty acids (FFAs) and leptin concentrations. In a human cross-sectional study of 55 patients [20 with type 2 diabetes mellitus (DM) and 21 normal-lean (NL) and 14 normal-obese (NO) subjects] who underwent hip replacement surgery, adipose and muscle tissue biopsies were obtained and analyzed for levels of hexosamines [UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-N-acetylgalactosamine] and hexoses (UDP-glucose and UDP-galactose). Fasting plasma glucose, glycosylated hemoglobin, serum insulin and homeostasis model assessment calculations, serum lipids, and leptin were measured on the same day. Hexosamines were not elevated in adipose and muscle tissue of patients with type 2 DM compared with NL and NO subjects (UDP-GlcNac DM vs. NL vs. NO, 3.3 +/- 2.3 vs. 2.2 +/- 2.1 vs. 3.0 +/- 2.0 nmol/g tissue in adipose tissue and 8.1 +/- 2.9 vs. 7.8 +/- 2.8 vs. 7.6 +/- 2.8 nmol/g tissue in muscle tissue, respectively). Hexosamines in adipose tissue were positively correlated with circulating levels of FFA (UDP-GlcNAc, r = 0.33, P < 0.05; UDP-N-acetylgalactosamine, r = 0.41, P < 0.01). Adipose tissue UDP-GlcNAc was correlated with leptin levels (r = 0.33; P < 0.05). No such relationship was identified in muscle tissue. In conclusion, these findings argue against a pathophysiological role of the hexosamine pathway in insulin resistance in humans but support the hypothesis that the hexosamine pathway in adipose tissue, not in muscle, is a FFA-sensing pathway and could be involved in the regulation of leptin expression.

Adipose Tissue↗

Hexosamines are unlikely to function as a nutrient-sensor in 3T3-L1 adipocytes: a comparison of UDP-hexosamine levels after increased glucose flux and glucosamine treatment.

Whether the hexosamine biosynthesis pathway acts as a nutrient-sensing pathway is still unclear. Glucose is directed into this pathway by GFAT. Because the activity of GFAT is tightly regulated, we examined whether UDP-hexosamine levels can increase significantly and dose-dependently in response to elevated glucose concentrations. In glucosamine-treated 3T3-L1 adipocytes, inhibition of insulin-stimulated glucose uptake was highly correlated with UDP-hexosamine levels (r = -0.992; p < 0.0001 for UDP-GlcNAc and r = -0.996; p < 0.0001 for UDP-GalNAc). Incubation of 3T3-L1 adipocytes with 0.1 microM insulin for 24 h in medium containing 1 and 5 mM glucose increased the rate of glucose uptake by 365% and 175% compared to untreated cells, respectively. This increase was not observed when the cells were incubated for 24 h with insulin in medium containing 10 or 25 mM glucose. However, treatment of cells with insulin and 1, 5, 10, or 25 mM glucose resulted in similar increases in levels of UDP-GlcNAc and UDP-GalNAc that always amounted to approx 30-40% above baseline values. This led us to conclude that despite exposure of adipocytes to conditions of extreme and prolonged glucose disposal, the increases in cellular UDP-hexosamines were minimal and not dependent on the extracellular glucose concentration. Taken together, our results are in line with the hypothesis that in glucosamine-treated adipocytes UDP-hexosamines influence insulin-stimulated glucose uptake. However, our observations in glucose-treated adipocytes argue against the possibility that UDP-hexosamines function as a nutrient-sensor, and question the role of the hexosamine biosynthesis pathway in the pathogenesis of insulin resistance.

3T3-L1 Cells↗

Vascular endothelial growth factor levels do not predict efficacy of systemic adjuvant treatment as assessed in 1127 breast cancer patients.

The vascular endothelial growth factor (VEGF) is a mediator of angiogenesis and has proven to be of prognostic value in patients with primary breast cancer. In this study we investigated whether VEGF is of predictive value with regard to the efficacy of adjuvant systemic therapy in primary invasive breast cancer. In 1127 tumors of patients with invasive breast cancer the cytosolic levels of VEGF were measured using a quantitative enzyme-linked immunosorbent assay. These patients were followed for a median follow-up time of 59 months (range 2-268 months) after primary surgery. Correlations with well-known prognostic factors, and univariate and multivariate survival analyses were performed. The VEGF levels showed a positive correlation with age, menopausal status and tumor size. In addition, VEGF levels were inversely correlated with estrogen and progesterone receptor levels. A high VEGF level predicted an early relapse in the univariate relapse-free survival (RFS) analysis for all patients (P=0.010), but not in the multivariate analysis. Furthermore, there were no statistically significant interactions between the levels of VEGF and the use of adjuvant endocrine therapy or chemotherapy in the RFS analysis. We conclude that tumor levels of VEGF do not predict the efficacy of adjuvant endocrine therapy or chemotherapy in patients with primary breast cancer.

Adult↗

Vascular endothelial growth factor is associated with the efficacy of endocrine therapy in patients with advanced breast carcinoma.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a mediator of angiogenesis and is associated with a poor prognosis in patients with primary breast carcinoma. In the current study, the authors investigated whether there was an association between VEGF levels in tumor tissues and response rates to first-line, systemic therapy in patients with advanced breast carcinoma. METHODS: In 172 tumors from patients with primary breast carcinoma who developed distant metastases during follow-up, cytosolic levels of VEGF were measured using a quantitative enzyme-linked immunosorbent assay. Patients received either endocrine therapy (n = 96) or chemotherapy (n = 76) as first-line treatment after they were diagnosed with advanced disease. RESULTS: In univariate logistic regression analysis for response to endocrine therapy in 96 patients, an increasing level of VEGF, as a log-transformed, continuous variable, was correlated with a poor rate of response (P = 0.043). In multivariate analysis, a significantly lower rate of response to first-line endocrine therapy was found for patients who had high VEGF levels compared with patients who had low VEGF levels (P = 0.025). Similar results were found for the subgroup of 82 patients who received tamoxifen (P = 0.011). An association of VEGF with response to first-line endocrine therapy was found in addition to a predictive impact for estrogen receptor/progesterone receptor status (P = 0.027). VEGF levels did not predict the rate of response to first-line chemotherapy. CONCLUSIONS: The results demonstrated that the level of VEGF affects response to endocrine therapy independent of steroid hormone receptor status and may help to refine further the indication for this treatment in individual patients. Further studies are warranted to explain this underlying resistance to endocrine therapy.

Adult↗

Cyclin-E is a strong predictor of endocrine therapy failure in human breast cancer.

Recently, cyclin-E was reported to be the most prominent prognostic factor for breast cancer outcome described so far, even surpassing axillary nodal involvement. Earlier studies on the prognostic value of cyclin-E in breast cancer, however, yielded heterogeneous results. Therefore, we set out to confirm and extend these results by quantitative Taqman RT-PCR of cyclin-E levels in 277 resectable breast cancers. Cyclin-E levels were not associated with relapse-free survival (RFS) or overall survival (OS) in the total cohort of patients, or in the subset of patients without involved lymph nodes that were not treated with adjuvant systemic therapy. Besides several classical clinicopathological factors, the interaction between cyclin-E and adjuvant endocrine therapy (P=0.01, HR=3.04, 95% CI: 1.30-7.09) was found to contribute significantly in multivariate analyses. Cyclin-E levels were associated with poor RFS specifically in patients treated with adjuvant endocrine therapy (n=108, P=0.001, HR=4.01, 95% CI: 1.76-9.12), independent of estrogen receptor status. In conclusion, cyclin-E is not a pure prognostic factor in breast cancer, but rather a predictor of failure of endocrine therapy. Differences in literature on the presumed prognostic value of cyclin-E may be due to differences in treatment. Assessment of cyclin-E levels can aid in improving adjuvant treatment selection.

Adult↗