Evidence that venous hypertension causes stasis dermatitis

A clinical model to examine the hypothesis that venous hypertension of the lower leg per se can cause lower leg stasis dermatitis is described. To prove this concept, we retrospectively studied a consecutive series of 38 patients with lower leg dermatitis who underwent phlebological examination at our consultation over a period of four years. Among those patients who had an insufficiency of the superficial veins only, without insufficiency of the deep veins, 22 had undergone patch testing to common allergens in phlebology. We found 10 patients with a stasis dermatitis of the lower leg and an incompetent great saphenous vein, six of whom had no detectable contact sensitization at all and another four exclusively to phlebologically irrelevant substances, e.g. nickel, cobalt, chromate or epoxid resin. All these 10 patients showed long saphenous vein incompetence from the groin to the medial aspect of the leg. All were operated by classical flush ligation and saphenectomy. Lower leg dermatitis healed in all 10 patients within 8–12 weeks and no recurrence was observed (1 year follow-up). These results support clinical experience that venous hypertension alone indeed can cause lower leg dermatitis.

[Recommendations for the use of polyhexanide-containing products for the treatment of wounds]

Polihexanide-containing wound products are often used for the treatment of acute and chronic wounds. Although information pertaining to the use of polihexanide can be found in the literature, the appropriate use of these products in clinical practice is not always clear. The goal of this short review is to provide clinically relevant recommendations to physicians and nurses treating patients with acute and chronic wounds. This review describes the clinically relevant characteristics of polihexanide and gives recommendations for the prophylaxis and treatment of wound infections.

Upregulation of the insulin receptor and type I insulin-like growth factor receptor are early events in hepatocarcinogenesis

The molecular mechanisms underlying the development of hepatocellular carcinoma (HCC) are not yet fully understood. Preneoplastic foci of altered hepatocytes regularly precede HCC in various species. The predominant earliest type of foci of altered hepatocytes, the glycogen storage focus (GSF), shows an excess of glycogen (glycogenosis) in the cytoplasm. During progression from GSF to HCC, the stored glycogen is gradually reduced, resulting in complete loss in basophilic HCC. We have previously shown that in N-nitrosomorpholine-induced hepatocarcinogenesis, insulin receptor substrate (IRS-1) is strongly expressed in GSF and reduced during progression to HCC, thus correlating with the glycogen content. In the present study, we observed increased levels of insulin receptor, IGF-I receptor (IGF-IR), IRS-2, and mitogen-activated kinase/extracellular regulated kinase-1 in GSF, following the same pattern of expression as IRS-1. We conclude that the abundance of IRS-1, IRS-2, and mitogen-activated kinase/extracellular regulated kinase-1 coincides with a concerted upregulation of both IR and IGF-IR induced by the hepatocarcinogen. Our data suggest that in early hepatocellular preneoplasia, the upregulation of IR elicits glycogenosis through IRS-1 and/or IRS-2, whereas the increased level of the IGF-IR may lead to the increased cell proliferation previously reported in GSF. Therefore, the concerted upregulation of both IR and IGF-IR may represent initial events in hepatocarcinogenesis.

Estrogens promote invasion of prostate cancer cells in a paracrine manner through up-regulation of matrix metalloproteinase 2 in prostatic stromal cells

Accumulating evidence suggests an enhancing effect of estrogens on prostate cancer (PCa) progression. Matrix metalloproteinase 2 (MMP2), which plays an important role in prostate cancer invasion, is mainly expressed in prostatic stromal cells (PrSC). Here we show that estradiol (E(2)) treatment up-regulates MMP2 production in PrSC, which promotes PCa cell invasion in a paracrine manner. Conditioned medium (CM) was collected from E(2)-treated prostatic stromal cell line WPMY-1 and primary PrSC. The CM of E(2)-treated WPMY-1 and PrSC promoted invasion of PCa cells, as measured by Matrigel transwell assays. Treatment with E(2) and 1,3,5-Tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole, an estrogen receptor-alpha (ERα) specific agonist, significantly up-regulated MMP2 expression in WPMY-1 and PrSC cells at both mRNA and protein levels. The CM treated with an anti-MMP2 antibody lost the stimulatory effect on invasion of PCa cells. The ER inhibitor ICI 182,780, as well as a TGFβ1 neutralizing antibody and ERα-specific small interfering RNA effectively suppressed E(2)-induced MMP2 expression in WPMY-1 cells. Mechanistic studies showed that E(2) up-regulated MMP2 in an indirect manner: E(2) induced TGFβ1 expression via ERα; TGFβ1 stimulated MMP2 expression in PrSC; the invasion of PCa cells were stimulated by elevated MMP2 expression induced by E(2) in a paracrine manner. Our data show that E(2) induces MMP2 expression in WPMY-1 and PrSC cells, which was mediated by TGFβ1. The effect of E(2) on invasion of PCa cells is mediated by up-regulation of MMP2 in a paracrine mechanism.

Self-regulation of commitment to reduce cigarette consumption: mental contrasting of future with reality

The model of fantasy realisation (Oettingen, 2000) specifies mental contrasting of a positive future with negative reality as a strategy that creates strong goal commitments. We propose that fantasies about a positive and negative future produce strong goal commitments when contrasted with the respective reality. The present study supports this hypothesis in the area of reducing cigarette consumption. Mental contrasting of a positive future with negative reality as well as mental contrasting of a negative future with positive reality led to taking immediate action when participants had high expectations of success. Results indicate that both fantasies about a positive future and a negative future can be used to commit to goals that benefit health and prevent disease.

Meeting report: 3rd international workshop on insulin & cancer heidelberg, Germany, october 30-31, 2010

The 3rd International Workshop on Insulin & Cancer was held on October 30-31, 2010 at the German Cancer Research Centre in Heidelberg/Germany. The topics followed-up the discussions of the previous workshops: possible differences in mitogenicity between natural insulin and genetically engineered insulin derivatives (insulin analogues), as shown by laboratory studies and epidemiologic studies alike; molecular studies on the links between metabolic and mitogenic effects of insulin, and of hyperinsulinaemia in particular; epidemiologic evidence of interferences between insulin and other hormones, particularly sex hormones, and obesity-associated cancer; the involvement of inflammatory cytokines produced by fat tissue in obesity-associated cancer; aspects of drug-design (binding drugs to albumin) and, last but not least, detection and investigation of circulating cancer cells.

Epigenetically deregulated microRNA-375 is involved in a positive feedback loop with estrogen receptor alpha in breast cancer cells

Estrogen receptor α (ERα) upregulation causes abnormal cell proliferation in about two thirds of breast cancers, yet understanding of the underlying mechanisms remains incomplete. Here, we show that high expression of the microRNA miR-375 in ERα-positive breast cell lines is a key driver of their proliferation. miR-375 overexpression was caused by loss of epigenetic marks including H3K9me2 and local DNA hypomethylation, dissociation of the transcriptional repressor CTCF from the miR-375 promoter, and interactions of ERα with regulatory regions of miR-375. Inhibiting miR-375 in ERα-positive MCF-7 cells resulted in reduced ERα activation and cell proliferation. A combination of expression profiling from tumor samples and miRNA target prediction identified RASD1 as a potential miR-375 target. Mechanistic investigations revealed that miR-375 regulates RASD1 by targeting the 3' untranslated region in RASD1 mRNA. Additionally, we found that RASD1 negatively regulates ERα expression. Our findings define a forward feedback pathway in control of ERα expression, highlighting new strategies to treat ERα-positive invasive breast tumors.

[Chronic venous insufficiency in postthrombotic syndrome and varicose veins]

Venous disorders have a high prevalence and require approximately 1% of health budgets of industrialized countries. The postthrombotic syndrome (PTS) is defined by subjective symptoms and morphologic trophical skin changes following deep venous thrombosis. Prevention of venous thromboembolism in risk situations, easy availability of diagnostic tools (D-dimers, colour-coded duplex sonography) and early detection of deep venous thrombosis, as well as immediate therapeutic anticoagulation along with leg compression during the acute phase and over a two year period of time significantly reduce the incidence of PTS. Chronic venous insufficiency (CVI) includes trophical skin and soft tissue pathologies of the lower leg due to venous hypertension in the distal venous system of the lower extremity. Roughly, two main causes can be distinguished. (A) Deep venous insufficiency (A1 in postthrombotic syndrome; A2 in primary deep venous insufficiency) and (B) superficial venous reflux, usually varicose veins. Compression therapy, surgical ablation of superficial venous reflux, and tangential ablation with split skin graft (shave treatment) of refractory venous ulcers are the mainstays in the treatment of CVI.

Current reversals and synchronization in coupled ratchets

Current reversal is an intriguing phenomenon that has been central to recent experimental and theoretical investigations of transport based on ratchet mechanism. By considering a system of two interacting ratchets, we demonstrate how the coupling can be used to control the reversals. In particular, we find that current reversal that exists in a single driven ratchet system can ultimately be eliminated with the presence of a second ratchet. For specific coupling strengths a current-reversal free regime has been detected. Furthermore, in the fully synchronized state characterized by the coupling threshold k(th), a specific driving amplitude a(opt) is found for which the transport is optimum.

Abdominal compartment syndrome

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are frequently encountered in critically ill patients and carry a high morbidity and mortality risk. Despite these facts, IAH/ACS are still overlooked by many physicians and therefore timely diagnosis is not made and treatment is often inadequate. All clinicians should be aware of the risk factors predicting IAH/ACS, the profound implications and derangements on all organ systems, the clinical presentation, the appropriate measurement of intra-abdominal pressure to detect IAH/ACS and the current treatment options for these detrimental syndromes. This comprehensive review provides knowledge about known facts, unresolved issues and future directions for research to improve patient survival and long-term outcome.

[A rare interstitital lung disease in two smokers]

Pulmonary Langerhans-cell histiocytosis should be suspected in patients with nodular or cystic changes in the upper pulmonary lobes. Patients with Langerhans-cell histiocytosis usually have a history of smoking; lack of nicotine exposure or an age over 60 years makes the diagnosis unlikely. The diagnostic work-up should include a high-resolution CT of the chest as well as a bronchoalveolar lavage, bronchoscopic and/or surgical lung biopsy. Smoking cessation is the essential part of the treatment.

Treatment with insulin glargine (Lantus) increases the proliferative potency of the serum of patients with type-1 diabetes: a pilot study on MCF-7 breast cancer cells

CONTEXT AND OBJECTIVE

Insulin glargine (Lantus) stimulates growth of MCF-7 cells stronger than human insulin. We investigated if serum from diabetic patients treated with glargine versus human insulin may display a similar effect.

METHODS

Pairs of serum samples from 31 C-peptide negative type-1 diabetic patients were investigated. In cross-over fashion, 23 patients were treated with glargine plus rapid-acting insulin analogues, and similar doses of human NPH and rapid-acting insulin. For comparison, eight patients were treated with insulin detemir (Levemir) and human NPH. MCF-7 cells were incubated with 10% serum and proliferation was assessed after 72 hours.

RESULTS

Serum containing insulin glargine was 1.11(95% CI 1.05-1.18) fold more mitogenic than human insulin-containing serum (p < 0.005); mitogenicity of serum containing detemir was 0.99(95% CI 0.98-1.02) fold that of human insulin-containing serum.

CONCLUSION

The serum of diabetic patients was slightly stronger mitogenic when using glargine as compared to human insulin or detemir for treatment.

Interaction of the double-strand break repair kinase DNA-PK and estrogen receptor-alpha

Here we show that, upon estrogen stimulation, DNA-dependent protein kinase (DNA-PK) forms a complex with estrogen receptor-α in a breast cancer cell line (MELN). Inhibition of DNA-PK by siRNA technology demonstrated that estrogen-induced ERα activation and cell cycle progression is, at least, partially dependent on DNA-PK.

Estrogens are suggested to play a role in the development and progression of proliferative diseases such as breast cancer. Like other steroid hormone receptors, the estrogen receptor-α (ERα) is a substrate of protein kinases, and phosphorylation has profound effects on its function and activity. Given the importance of DNA-dependent protein kinase (DNA-PK) for DNA repair, cell cycle progression, and survival, we hypothesized that it modulates ERα signaling. Here we show that, upon estrogen stimulation, DNA-PK forms a complex with ERα in a breast cancer cell line (MELN). DNA-PK phosphorylates ERα at Ser-118. Phosphorylation resulted in stabilization of ERα protein as inhibition of DNA-PK resulted in its proteasomal degradation. Activation of DNA-PK by double-strand breaks or its inhibition by siRNA technology demonstrated that estrogen-induced ERα activation and cell cycle progression is, at least, partially dependent on DNA-PK.

Responding to patient safety incidents: the "seven pillars"

BACKGROUND

Although acknowledged to be an ethical imperative for providers, disclosure following patient safety incidents remains the exception. The appropriate response to a patient safety incident and the disclosure of medical errors are neither easy nor obvious. An inadequate response to patient harm or an inappropriate disclosure may frustrate practitioners, dent their professional reputation, and alienate patients.

METHODS

The authors have presented a descriptive study on the comprehensive process for responding to patient safety incidents, including the disclosure of medical errors adopted at a large, urban tertiary care centre in the United States.

RESULTS

In the first two years post-implementation, the "seven pillars" process has led to more than 2,000 incident reports annually, prompted more than 100 investigations with root cause analysis, translated into close to 200 system improvements and served as the foundation of almost 106 disclosure conversations and 20 full disclosures of inappropriate or unreasonable care causing harm to patients.

CONCLUSIONS

Adopting a policy of transparency represents a major shift in organisational focus and may take several years to implement. In our experience, the ability to rapidly learn from, respond to, and modify practices based on investigation to improve the safety and quality of patient care is grounded in transparency.

Mental Contrasting of Future and Reality

Mental contrasting of a desired future with present reality leads to expectancy-dependent goal commitments, whereas focusing on the desired future only makes people commit to goals regardless of their high or low expectations for success. In the present brief intervention we randomly assigned middle-level managers (N = 52) to two conditions. Participants in one condition were taught to use mental contrasting regarding their everyday concerns, while participants in the other condition were taught to indulge. Two weeks later, participants in the mental-contrasting condition reported to have fared better in managing their time and decision making during everyday life than those in the indulging condition. By helping people to set expectancy-dependent goals, teaching the metacognitive strategy of mental contrasting can be a cost- and time-effective tool to help people manage the demands of their everyday life.

Continuous monitoring of ruminal pH using wireless telemetry

This paper describes the performance of a prototype telemetric intraruminal bolus that measures and records pH continuously, can be delivered orally to the reticulum via bolling gun, has no external attachments and allows unrestricted activity of the animal. When interrogated by wireless the bolus transmits the recorded data to an operator standing beside the animal with a handheld receiving station. Boluses were placed in fistulated animals to enable direct comparison with samples obtained directly from the rumen and measured with a laboratory instrument. Overall, the mean (±s.d.) pH recorded on the manually collected samples (pH 6.64 ± 0.67) was generally less than that of the continuously measured telemetric system (pH 7.03 ± 0.54) with a correlation of r = 0.93 (P < 0.01). Data are presented to show typical diurnal and grain-enforced changes in pH recorded in a rumen over a 70-day period. The development of the Well Cow pH bolus device potentially enables researchers, dairy farmers and feedlot managers to monitor rumen function of any ruminant over prolonged periods without the need for invasive sampling. Enemark et al. (2003) considered that a 14–21-day observational period is required to properly monitor for conditions such as subacute ruminal acidosis. Whilst significant correlation (P < 0.01; r = 0.982) existed between the two readings for the first 40 days of continuous recording, the Well Cow pH bolus reading started to deviate significantly from the directly measured value thereafter. Regardless, a continuously measuring functional life of up to 40 days indicates that the current prototype has the capacity to accurately detect subacute ruminal acidosis.

Specific involvement of glycogen synthase kinase-3 in the function and activity of sex steroid hormone receptors reveals the complexity of their regulation

Protein kinases represent key nodes for the integration of multiple intracellular signalling pathways, resulting in modulation of both ligand-dependent and ligand-independent mechanisms of sex steroid receptor (sSR) signalling cascades. The proline-directed Ser/Thr kinases including mitogen-activated protein kinases and cyclin dependent kinases were especially reported to contribute to the function and activity of sSRs. The relevant effects of these kinases are well-documented but the impact of glycogen synthase kinase-3 (GSK-3), another member of this kinase family, has been underestimated. Indeed, the specific role of GSK-3 regarding the different sSRs will help to understand further the complexity of sSR signalling. So far, AR and ERalpha were identified as GSK-3 substrates. Additionally, the docking properties of GSK-3 were demonstrated to play a crucial role in sSR signal transduction. Reciprocally, GSK-3 was described as a potential target of non-genomic effects of sSRs. Therefore, GSK-3 regulates and is regulated by sSRs. This review focuses on the emerging and promising involvements of GSK-3 regarding the signalling cascade of the respective sSRs. This review represents a necessary complement of information to highlight the importance of GSK-3 regarding sSR function and activity.

Proliferative effect of Apidra (insulin glulisine), a rapid-acting insulin analogue on mammary epithelial cells

The structural modification of insulin results in the generation of insulin analogues that show altered binding affinities to the insulin receptor and/or the IGF-I receptor, and as a consequence insulin analogues may have altered mitogenic potency. We analysed the proliferative effect of the rapid-acting insulin analogue Apidra (insulin glulisine) on mammary epithelial cells. We show that Apidra and Actrapid (recombinant human insulin) have similar proliferative effects on benign MCF10A and tumorigenic MCF7 cells and on epithelial cells of mouse mammary gland. Whereas Apidra and Actrapid induced similar activation of Erk1/2, activation of Akt/PKB by Apidra was significantly weaker compared to regular insulin. As AKT/PKB, an effector of the phosphoinositide 3-kinase pathway, mediates metabolic effects of insulin, we studied induction of hexokinase-2 in MCF7 cells and hexokinase-2 and hexokinase-4 in HepG2 cells by Actrapid and Apidra. Both genes were not significantly induced by Actrapid and Apidra in these cell lines.

Ovulation-stimulation drugs and cancer risks: a long-term follow-up of a British cohort

To assess long-term health effects of ovarian-stimulation drugs we followed-up for over 20 years a British cohort of 7355 women with ovulatory disorders, 43% of whom were prescribed ovarian-stimulation drugs, and identified a total of 274 deaths and 367 incident cancers. Relative to the general population, the cohort experienced lower mortality from most causes, including from all neoplasms combined, and lower incidence of cervical cancer, but higher incidence of cancers of the breast (relative risk: 1.13; 95% CI 0.97, 1.30) and corpus uteri (2.02; 1.37, 2.87). There were, however, no significant differences in the risk of cancers of the breast, corpus uteri, ovary, or of any other site, between women who had been prescribed ovarian-stimulation drugs and those who had not. Further analyses by type of drug and dose revealed a dose-response gradient in the risk of cancer of the corpus uteri (P for linear trend=0.03), with women given >or=2250 mg of clomiphene having a 2.6-fold (2.62; 0.94, 6.82) increase in risk relative to those who were not treated. These findings do not support strong associations between ovulation-stimulation drugs and cancer risks, but they indicate the need for continued monitoring to establish whether risks are elevated in certain subgroups of users.

Analysis of signaling pathways related to cell proliferation stimulated by insulin analogs in human mammary epithelial cell lines

Insulin and insulin analogs stimulate proliferation of human mammary epithelial cells. We identified and analyzed the signaling pathways related to cell proliferation induced by regular insulin and by four insulin analogs presently approved for therapeutical use. Benign and malignant mammary cell lines showing different insulin receptor (IR) and IGF-I receptor (IGF-IR) expression patterns were studied. Cell proliferation was studied by crystal violet staining (BrdU-FACS analysis). Activation of insulin and IGF signaling pathways was studied by analysis of the phosphorylation status of IGF-IR and of key signaling proteins of the phosphoinositide 3-kinase (PI3K)/Akt and MAP kinase pathways, by the use of specific PI3K and MAP kinase inhibitors, and by silencing of IR and IGF-IR. Lantus stimulated the growth of MCF7 cells, which show high IGF-IR/IR ratio, significantly at 0.3 nmol/l, while regular insulin (Actrapid and bovine insulin) and other insulin analogs (Novorapid, Humalog, and Levemir) stimulated cell growth at 1.5-15 nmol/l concentrations. No difference between Lantus and the other insulin analogs was observed regarding growth stimulation of MCF10A cells showing low IGF-IR/IR ratio. Growth stimulation of MCF7 cells by Lantus was mainly due to strong activation of the IGF-IR and the MAP kinase pathway. Regular insulin and other insulin analogs tested activated mainly the IR and the PI3K/Akt pathway. We conclude that unlike regular insulin and other insulin analogs, Lantus strongly activates the IGF-IR and the MAP kinase pathway in MCF7 cells and is a strong mitogen for cells characterized by a high-IGF-IR/IR ratio.

Mental Contrasting and Goal Commitment: The Mediating Role of Energization

Mentally contrasting a desired future with present reality is a self-regulation strategy that leads to goal commitment in line with a person's expectations of success. One possible mediator variable of these effects is level of energization. In Study 1, energization assessed by physiological measures was found to mediate the effect of mental contrasting on goal commitment. In Study 2, feelings of energization, as assessed by self-report, mediated the effect of mental contrasting on goal commitment as gauged by performance on an acute stress paradigm (giving a talk in front of a camera). Results imply that when expectations of success are high, mental contrasting provides the level of energy needed to commit to realizing desired futures.

Dihydrotestosterone interacts with EGFR/MAPK signalling and modulates EGFR levels in androgen receptor-positive LNCaP prostate cancer cells

Androgen receptor (AR) signalling plays a pivotal role in prostate cancer pathogenesis and progression. However, androgen-mediated AR signalling is yet to be fully understood. EGFR and MAP kinase signalling pathways play predominant roles in AR function. Therefore, we investigated the interaction of EGFR signalling and AR activity in AR-positive LNCaP cells. We found that 5alpha-dihydrotestosterone (DHT) and EGF had a synergistic effect on AR activity as detected by a luciferase reporter system, although EGF alone did not activate AR. Both ERK1/2 and p38 were involved in DHT and DHT/EGF-induced AR activation as detected by specific MEK and p38 inhibitors. Furthermore, 24-h treatment of the cells with DHT resulted in ubiquitination and down-regulation of the EGFR. This effect could be inhibited by the anti-androgen flutamide, suggesting an androgen-dependent mechanism. On the other hand, DHT-treatment strongly increased AR levels in LNCaP cells. These data suggest a complex regulatory loop between activated AR and EGFR. In conclusion, activation of AR by both DHT and EGF/DHT involves the MAP kinase pathway. Long-term activation of AR results in increase of AR levels, which through so far unknown regulatory mechanisms results in ubiquitination and degradation of the EGFR.

Effect of N-chlorotaurine mouth rinses on plaque regrowth and plaque vitality

The purpose of this 4-day plaque regrowth study was to assess the effect of N-chlorotaurine (NCT) mouth rinses on plaque inhibition and plaque vitality. Eighty volunteers participated in this investigator-blind, randomized, clinical controlled study in parallel groups. No oral hygiene was permitted except rinsing with a 2% or 3% NCT mouth rinse, a positive or a negative control. Primary parameters were the plaque index (Silness and Löe, Acta Odontol Scand, 22:121-135, 1964) and plaque vitality (Netuschil et al., J Clin Periodontol, 16:484-488, 1989) after the final rinse. In addition, another plaque index (Turesky et al., J Periodontol, 41:41-43, 1970), plaque area, and bleeding on probing were recorded. All parameters were taken at baseline and day 5. U test was applied on a 5% error level. No differences in plaque inhibition were found between the two NCT formulations and the negative control. However, a statistically significant reduction of plaque vitality compared to the negative and positive control was observed. Discoloration of the tongue and unpleasant taste were recorded in participants in the NCT groups. NCT mouth rinses did not inhibit plaque regrowth, but they did reduce the vitality of plaque bacteria. Methods of prolonging the substantivity of the NCT mouth rinses should be investigated to enhance the antibacterial properties of these formulations.

Cholangiocarcinoma complicating primary sclerosing cholangitis: a 24-year experience

AIM

To report the prevalence and outcome of cholangiocarcinoma arising in primary sclerosing cholangitis for a British tertiary referral centre.

METHODS

All patients diagnosed with primary sclerosing cholangitis and concurrent cholangiocarcinoma were identified from a prospectively maintained departmental database, and the mode of presentation, management and outcome were determined.

RESULTS

Of 370 patients with primary sclerosing cholangitis, 48 patients (13%) were diagnosed with a cholangiocarcinoma within a median time of 0.51 months (range: 0-73.12) from presentation to the unit. Mode of presentation included: inoperable tumours (n = 14); incidental findings in transplant hepatectomy specimens (n = 13); primary sclerosing cholangitis follow-up (n = 9); transplant work-up (n = 5); transplant waiting list (n = 5); suspected tumour confirmed at transplant (n = 1), and incidental finding at cholecystectomy (n = 1). The diagnosis was confirmed by: radiology-guided biopsy (n = 27); MRI (n = 3); CT (n = 2); laparoscopy or laparotomy (n = 2), and frozen section at transplant (n = 1). Management consisted of: transplantation (n = 14, including 1 abandoned); hepatic resection (n = 8), and palliation through stenting (n = 26). The overall median survival of the cohort was 4.9 months (range: 0.09-104.5). Median survival ranged from 2.6 months (range: 0.09-35.3) for palliation to 7.6 months (range: 0.6-99.6) for transplantation and 52.8 months (range: 3.7-104.5) for resection. There was no difference in survival between the transplant and resection groups (p = 0.14).

CONCLUSIONS

Cholangiocarcinoma is a common finding in primary sclerosing cholangitis and regular screening of this cohort of patients at referring centres is advocated to detect early tumours, as surgical treatment at an early stage offers significantly better outcomes for this cohort of patients.

Proliferative effects of insulin analogues on mammary epithelial cells

Structural modification of insulin results in the generation of insulin analogues that show altered binding affinities to the insulin receptor and/or IGF-I receptor. As a consequence these insulin analogues may have increased mitogenic potency. Nine benign or malignant human mammary epithelial cells, which show different insulin receptor and IGF-I receptor expression patterns, were studied regarding mitogenicity of insulin and insulin analogues. Only insulin glargine showed a significantly higher proliferative effect on MCF-7 breast cancer cells compared to regular insulin among a panel of short- or long-acting insulin analogues, that are in clinical use.

Optimization of fast spiral chemical shift imaging using least squares reconstruction: application for hyperpolarized (13)C metabolic imaging

A least-squares-based optimization and reconstruction algorithm has been developed for rapid metabolic imaging in the context of hyperpolarized (13)C. The algorithm uses a priori knowledge of resonance frequencies, J-coupling constants, and T(2)* values to enable acquisition of high-quality metabolic images with imaging times of approximately 100 ms for an 8-cm field of view (FOV) and 0.5 cm isotropic resolution. A root-mean-square error (rMSE) analysis is introduced to optimize metabolic image quality by appropriate choice of pulse sequence parameters, echo times, and signal model. By performing the reconstruction in k-space, the algorithm also allows the inclusion of the effect of chemical shift evolution during the readout period. Single-interleaf multiecho spiral chemical shift imaging (spCSI) is analyzed in detail as an illustrative example for the use of the new reconstruction and optimization algorithm. Simulation of the in vivo spectrum following the bolus injection of hyperpolarized (13)C(1) pyruvate shows that single-interleaf spiral spectroscopic imaging can achieve image quality in 100 ms, comparable to the performance of a 13-s phase-encoded chemical shift imaging (FIDCSI) experiment. Single-interleaf spCSI was also tested at a 3-T MR scanner using a phantom containing approximately 0.5-M solutions of alanine, lactate, and a pyruvate-pyruvate hydrate C(1)-C(2) ester at thermal equilibrium polarization, all enriched to 99% (13)C in the C(1) carbonyl positions. Upon reconstruction using the k-space-based least-squares technique, metabolite ratios obtained using the spCSI method were comparable to those obtained using a reference FIDCSI acquisition.

Elevated insulin-like growth factor-I receptor (IGF-IR) levels in primary breast tumors associated with BRCA1 mutations

The insulin-like growth factors (IGFs) play a pivotal role in breast cancer. Inherited predisposition to breast and ovarian cancer is associated with germline BRCA1/BRCA2 mutations. To evaluate the impact of BRCA1 mutations on IGF-IR gene expression, we performed an immunohistochemical analysis of IGF-IR in primary breast tumors from BRCA1 mutation carriers and non-carriers. Results obtained revealed a significant elevation in IGF-IR levels in tumors from BRCA1 mutation carriers compared with non-carriers. To assess the potential inhibitory role of BRCA1 on IGF-IR levels, we infected the BRCA1-deficient HCC1937 cell line with a BRCA1-encoding adenoviral vector. Results of Western blots showed that BRCA1 induced a large reduction in endogenous IGF-IR levels. Furthermore, results of chromatin immunoprecipitation assays indicated that the mechanism of action of BRCA1 involves interaction with Sp1, a potent transactivator of the IGF-IR gene. In conclusion, our data suggests that the IGF-IR gene is a physiologically relevant downstream target for BRCA1 action.

Glycogen synthase kinase-3 protects estrogen receptor alpha from proteasomal degradation and is required for full transcriptional activity of the receptor

Glycogen synthase kinase-3 (GSK-3) plays a key role in the regulation of transcription factors including steroid receptors. Having identified estrogen receptor-alpha (ERalpha) as substrate for GSK-3, the impact of GSK-3 on ERalpha function and activity upon 17beta-estradiol (E2)-dependent activation remains to be clarified. Here we show by using small interfering technology in combination with immunoblot, gene expression analysis, and luciferase reporter assays that silencing of GSK-3alpha or GSK-3beta results in the reduction of ERalpha levels and transcriptional activity in ERalpha-positive breast cancer cells. Using MCF-7 cells we demonstrate that reduction of ERalpha levels upon GSK-3 silencing was due to increased proteasomal degradation of ERalpha rather than inhibition of ERalpha protein synthesis. Indeed, under this condition, ERalpha protein was rescued using the proteasome inhibitor MG132 in presence of the protein synthesis inhibitor cycloheximide. In addition, strong accumulation of ubiquitinated ERalpha was obtained after GSK-3 silencing in the presence of MG132. We conclude that GSK-3 protects ERalpha from proteasomal degradation and plays a crucial role in ERalpha protein stabilization and turnover. Furthermore, in vitro kinase assay depicted that GSK-3beta phosphorylates ERalpha at Ser-118. GSK-3 silencing resulted in decrease of E2-induced nuclear ERalpha phosphorylation at Ser-118 and E2-induced estrogen response element-dependent luciferase reporter gene expression. Neither Ser-118 phosphorylation nor luciferase activity was restored by use of MG132. Moreover, the expression of estrogen-responsive genes (pS2 and progesterone receptor) was decreased upon GSK-3 silencing. These findings demonstrated that GSK-3 is required for E2-induced ERalpha phosphorylation at Ser-118 and full transcriptional activity of the receptor upon E2 stimulation.

Field-effect sensors with charged macromolecules: Characterisation by capacitance–voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods

Field-effect-based capacitive electrolyte-insulator-semiconductor (EIS) sensors have been utilised for the deoxyribonucleic acid (DNA) immobilisation and hybridisation detection as well as for monitoring the layer-by-layer adsorption of polyelectrolytes (anionic poly(sodium 4-styrene sulfonate) (PSS) and cationic poly(allylamine hydrochloride) (PAH)). The EIS sensors with charged macromolecules have been systematically characterised by capacitance-voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods. The effect of the number and polarity of the polyelectrolyte layers on the shift of the capacitance-voltage curves has been investigated. Alternating potential shifts of about 30-90 mV have been observed after the adsorption of each polyanion and polycation layer, respectively. The DNA immobilisation and hybridisation signals were 35-55 and 24-33 mV, respectively. The possible mechanisms for the sensor responses are discussed.

Insulin-like growth factor-I controls BRCA1 gene expression through activation of transcription factor Sp1

The insulin-like growth factors (IGFs) have a central role in mammary gland growth and differentiation as well as in breast cancer development. The BRCA1 gene encodes a pleiotropic protein that functions as a transcription factor. Germline BRCA1 mutations are associated with inherited predisposition to breast and ovarian cancer and confer a substantially increased risk for developing these neoplasms. Several lines of evidence led us to hypothesize that there is a functional interaction between the BRCA1 and IGF-I systems relevant to breast cancer biology. The present study tested the notion that BRCA1 gene expression is regulated by the IGF-I signaling pathway. Results of Western immunoblotting and RT-PCR analyses show that IGF-I stimulates BRCA1 protein and mRNA levels. Transient transfection experiments using BRCA1 promoter-luciferase reporter constructs reveal that IGF-I enhances BRCA1 promoter activity, suggesting that the effect of IGF-I is mediated at the transcriptional level. In addition, we provide evidence that the Sp1 zinc-finger protein is directly involved in BRCA1 gene transactivation. Combined, our data suggests that, at least part of the biological actions of IGF-I in mammary gland cells may be mediated through BRCA1. Dysregulated BRCA1 expression resulting from aberrant IGF signaling may have important consequences relevant to breast cancer pathogenesis.

Estrogen receptor regulates insulin-like growth factor-I receptor gene expression in breast tumor cells: involvement of transcription factor Sp1

The insulin-like growth factors, IGF-I and IGF-II are a family of mitogenic polypeptides with important roles in growth and differentiation. The biological actions of the IGFs are mediated by the IGF-I receptor (IGF-IR), a cell-surface tyrosine kinase, whose activation by serum IGF-I seems to be a key step in breast cancer initiation. Evidence accumulated indicates that estrogens stimulate the expression and activity of IGF axis components. The aim of our study was to examine the transcriptional mechanisms involved in regulation of IGF-IR gene expression by the estrogen receptor (ER). For this purpose, transient transfections using an IGF-IR promoter-luciferase reporter plasmid were performed in breast cancer-c derived ER-positive MCF-7 cells and isogenic ER-negative C4 cells. To examine the potential involvement of zinc-finger nuclear proteins in the transactivating effect of estrogens, chromatin immunoprecipitation (ChIP) experiments were performed using an Sp1 antibody, along with the Sp1-family-binding inhibitor Mithramycin A. The results obtained indicate that basal IGF-IR promoter activity was 5.8-fold higher in MCF-7 than in C4 cells. Estradiol treatment significantly activated the IGF-IR promoter in MCF-7, but not in C4 cells. Furthermore, the estrogen responsive region in the IGF-IR promoter was mapped to a GC-rich sequence located between nucleotides -40 and -188 in the 5' flanking region. ChIP experiments revealed that at least part of the estrogen effect on IGF-IR expression was mediated through activation of the Sp1 transcription factor. In summary, our studies demonstrate that IGF-IR gene transcription in breast cancer cells is controlled by interactions between ERalpha and Sp1. Dysregulated expression of the IGF-IR gene may have pathologic consequences with relevance in breast cancer etiology.