405 research outputs found
Pathophysiology of acute experimental pancreatitis: Lessons from genetically engineered animal models and new molecular approaches
The incidence of acute pancreatitis is growing and worldwide population-based studies report a doubling or tripling since the 1970s. 25% of acute pancreatitis are severe and associated with histological changes of necrotizing pancreatitis. There is still no specific medical treatment for acute pancreatitis. The average mortality resides around 10%. In order to develop new specific medical treatment strategies for acute pancreatitis, a better understanding of the pathophysiology during the onset of acute pancreatitis is necessary. Since it is difficult to study the early acinar events in human pancreatitis, several animal models of acute pancreatitis have been developed. By this, it is hoped that clues into human pathophysiology become possible. In the last decade, while employing molecular biology techniques, a major progress has been made. The genome of the mouse was recently sequenced. Various strategies are possible to prove a causal effect of a single gene or protein, using either gain-of-function (i.e., overexpression of the protein of interest) or loss-of-function studies (i.e., genetic deletion of the gene of interest). The availability of transgenic mouse models and gene deletion studies has clearly increased our knowledge about the pathophysiology of acute pancreatitis and enables us to study and confirm in vitro findings in animal models. In addition, transgenic models with specific genetic deletion or overexpression of genes help in understanding the role of one specific protein in a cascade of inflammatory processes such as pancreatitis where different proteins interact and co-react. This review summarizes the recent progress in this field. Copyright (c) 2005 S. Karger AG, Basel
Impact of iron addition on phosphorus dynamics in sediments of a shallow peat lake 10 years after treatment
Internal phosphorus (P) loading is a key water quality challenge for shallow lakes. Addition of iron (Fe) salts has been used to enhance P retention in lake sediments. However, its effects on sediment geochemistry are poorly studied, albeit pivotal for remediation success. Here, we assess the factors controlling the retention of P and long-term effects following application of FeCl3 (0.5–1 mol Fe/m2, 2010) in the eutrophic, shallow peat lake Terra Nova (the Netherlands). Treatment reduced P levels in the lake for two years, but afterwards summer release of P intensified, resulting in higher surface water P concentrations than before treatment. Porewater and sediment analyses indicate that the majority of the added Fe is still undergoing redox cycling within the top 10 cm of sediment accounting for the binding of up to 70 % of sedimentary P. Sequential extractions further suggest that organic matter (OM) plays a key role in the resulting P and Fe dynamics: While reduction of P binding Fe(III) phases results in P release to porewaters, the produced Fe2+ remains bound to the solid phase presumably stabilized by OM. This causes P release from the sediments in excess to Fe during temporary low oxygen conditions in summer months, as confirmed by whole core flux incubation experiments. Quantitative coprecipitation of P with Fe upon reoxygenation of the water body is then impossible, leading to a gradual increase in surface water P. This first long-term study on a shallow peat lake underpins the role of OM for Fe cycling and the need to carefully consider the sediment properties and diagenetic pathways in the planning of Fe-amendments
Anal canal cancer treatment: practical limitations of routine prescription of concurrent chemotherapy and radiotherapy
Pheochromocytoma presenting as recurrent urinary tract infections : a case report
<p>Abstract</p> <p>Introduction</p> <p>Pheochromocytomas are rare, potentially fatal, neuroendocrine tumors of the adrenal medulla or extra-adrenal paraganglia. Their clinical presentation varies greatly from the classic triad of episodic headache, diaphoresis and tachycardia to include a spectrum of non-specific symptomatology.</p> <p>Case presentation</p> <p>A 43-year-old Caucasian woman was referred to us from primary care services with a three-month history of recurrent urinary tract infections on a background of hypertension, latent autoimmune diabetes of adulthood and autoimmune hypothyroidism. At 38 years she required insulin therapy. Despite medication compliance and dietary control, she reported a recent history of increased insulin requirements and uncontrolled hypertension with concomitant recurrent urinary tract infections. A renal ultrasound examination, to rule out underlying renal pathology, revealed an incidental 8cm right adrenal mass of both solid and cystic components. A subsequent computed tomography of her abdomen and pelvis confirmed a solid heterogeneous mass consistent with a pheochromocytoma. There were no other features suggestive of multiple endocrine neoplasia. Urinary collection over 24 hours revealed grossly elevated levels of catecholamines and metabolites. Following an open right adrenalectomy, our patient's insulin requirements were significantly reduced and her symptoms resolved. Two weeks post-operatively, an iodine-131-metaiodobenzylguanidine scintigraphy was negative for residual tumor and metastatic disease. Urinary catecholamine and metabolite concentrations were within the normal range at a follow-up six months later.</p> <p>Conclusion</p> <p>Pheochromocytoma is a rare catecholamine-producing tumor requiring a high index of suspicion for early diagnosis. Our case report serves to highlight the importance of considering pheochromocytoma as a differential diagnosis in the atypical setting of recurrent urinary tract infections and concomitant autoimmune disease.</p
Effect of 18F-fluciclovine positron emission tomography on the management of patients with recurrence of prostate cancer: Results from the FALCON Trial
Purpose:
Early and accurate localization of lesions in patients with biochemical recurrence (BCR) of prostate cancer may guide salvage therapy decisions. The present study, 18F-Fluciclovine PET/CT in biochemicAL reCurrence Of Prostate caNcer (FALCON; NCT02578940), aimed to evaluate the effect of 18F-fluciclovine on management of men with BCR of prostate cancer.
Methods and Materials:
Men with a first episode of BCR after curative-intent primary therapy were enrolled at 6 UK sites. Patients underwent 18F-fluciclovine positron emission tomography/computed tomography (PET/CT) according to standardized procedures. Clinicians documented management plans before and after scanning, recording changes to treatment modality as major and changes within a modality as other. The primary outcome measure was record of a revised management plan postscan. Secondary endpoints were evaluation of optimal prostate specific antigen (PSA) threshold for detection, salvage treatment outcome assessment based on 18F-fluciclovine-involvement, and safety.
Results:
18F-Fluciclovine was well tolerated in the 104 scanned patients (median PSA = 0.79 ng/mL). Lesions were detected in 58 out of 104 (56%) patients. Detection was broadly proportional to PSA level; ≤1 ng/mL, 1 out of 3 of scans were positive, and 93% scans were positive at PSA >2.0 ng/mL. Sixty-six (64%) patients had a postscan management change (80% after a positive result). Major changes (43 out of 66; 65%) were salvage or systemic therapy to watchful waiting (16 out of 66; 24%); salvage therapy to systemic therapy (16 out of 66; 24%); and alternative changes to treatment modality (11 out of 66, 17%). The remaining 23 out of 66 (35%) management changes were modifications of the prescan plan: most (22 out of 66; 33%) were adjustments to planned brachytherapy/radiation therapy to include a 18F-fluciclovine-guided boost. Where 18F-fluciclovine guided salvage therapy, the PSA response rate was higher than when 18F-fluciclovine was not involved (15 out of 17 [88%] vs 28 out of 39 [72%]).
Conclusions:
18F-Fluciclovine PET/CT located recurrence in the majority of men with BCR, frequently resulting in major management plan changes. Incorporating 18F-fluciclovine PET/CT into treatment planning may optimize targeting of recurrence sites and avoid futile salvage therapy
CONFIRM: a double-blind, placebo controlled phase III clinical trial investigating the effect of nivolumab in patients with relapsed mesothelioma: study protocol for a randomised controlled trial
Background: Mesothelioma is an incurable, apoptosis-resistant cancer caused in most cases by previous exposure
to asbestos and is increasing in incidence. It represents a growing health burden but remains under-researched,
with limited treatment options. Early promising signals of activity relating to both PD-L1- and PD-1-targeted
treatment in mesothelioma implicate a dependency of mesothelioma on this immune checkpoint. There is a need
to evaluate checkpoint inhibitors in patients with relapsed mesothelioma where treatment options are limited.
Methods: The addition of 12 months of nivolumab (anti-PD1 antibody) to standard practice will be conducted in
the UK using a randomised, placebo-controlled phase III trial (the Cancer Research UK CONFIRM trial). A total of 336
patients with pleural or peritoneal mesothelioma who have received at least two prior lines of therapy will be
recruited from UK secondary care sites. Patients will be randomised 2:1 (nivolumab:placebo), stratified according to
epithelioid/non-epithelioid, to receive either 240 mg nivolumab monotherapy or saline placebo as a 30-min
intravenous infusion. Treatment will be for up to 12 months. We will determine whether the use of nivolumab
increases overall survival (the primary efficacy endpoint). Secondary endpoints will include progression-free
survival, objective response rate, toxicity, quality of life and cost-effectiveness. Analysis will be performed
according to the intention-to-treat principle using a Cox regression analysis for the primary endpoint (and
for other time-to-event endpoints).
Discussion: The outcome of this trial will provide evidence of the potential benefit of the use of nivolumab
in the treatment of relapsed mesothelioma. If found to be clinically effective, safe and cost-effective it is likely
to become the new standard of care in the UK
Bromodeoxyuridine Labeling Index as an Indicator of Early Tumor Response to Preoperative Radiotherapy in Patients with Rectal Cancer
PURPOSE: Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal cancer response to preoperative radiotherapy (RT). METHODS AND MATERIAL: Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I), or to short RT and 4–5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37°C, and the BrdUrdLI was calculated as a percentage of BrdUrd-labeled cells. RESULTS: Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios were calculated separately for fast (BrdUrd LI > 8.5%) and slowly (BrdUrd LI ≤ 8.5%) proliferating tumors and correlated with overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation was observed only in slowly proliferating tumors. CONCLUSIONS: Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI was correlated to inhibition of proliferation in responsive tumors
Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition
Limited Value of Staging Squamous Cell Carcinoma of the Anal Margin and Canal Using the Sentinel Lymph Node Procedure: A Prospective Study with Long-Term Follow-Up
Background. Selection of patients with anal cancer for groin irradiation is based on tumor size, palpation, ultrasound, and fine needle cytology. Current staging of anal cancer may result in undertreatment in small tumors and overtreatment of large tumors. This study reports the feasibility of the sentinel lymph node biopsy (SLNB) in patients with anal cancer and whether this improves the selection for inguinal radiotherapy. Methods. A total of 50 patients with squamous anal cancer were evaluated prospectively. Patients without a SLNB (n = 29) received irradiation of the inguinal lymph nodes based on lymph node status, tumor size, and location of the primary tumor. Inguinal irradiation treatment in patients with a SLNB was based on the presence of metastases in the SLN. Results. SLNs were found in all 21 patients who underwent a SLNB. There were 5 patients (24%) who had complications after SLNB and 7 patients (33%) who had a positive SLN and received inguinal irradiation. However, 2 patients with a tumor-free SLN and no inguinal irradiation developed lymph node metastases after 12 and 24 months, respectively. Conclusions. We conclude that SLNB in anal cancer is technically feasible. SLNB can identify those patients who would benefit from refrain of inguinal irradiation treatment and thereby reducing the incidence of unnecessary inguinal radiotherapy. However, because of the occurrence of inguinal lymph node metastases after a tumor-negative SLNB, introduction of this procedure as standard of care in all patients with anal carcinoma should be done with caution to avoid undertreatment of patient who otherwise would benefit from inguinal radiotherapy
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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