Browse

You are looking at 1 - 10 of 819 items for

  • All content x
Clear All
Open access

David S. Mathiesen, Jonatan I. Bagger, Katrine B. Hansen, Anders E. Junker, Astrid Plamboeck, Signe Harring, Thomas Idorn, Mads Hornum, Jens J Holst, Anna E Jonsson, Torben Hansen, Tina Vilsbøll, Asger Lund, and Filip K Knop

The T allele of TCF7L2 rs7903146 is a common genetic variant associated with type 2 diabetes (T2D), possibly by modulation of incretin action. In this study, we evaluated the effect of the TCF7L2 rs7903146 T allele on the incretin effect and other glucometabolic parameters in normal glucose tolerant individuals (NGT) and participants with T2D. The rs7903146 variant was genotyped in cohorts of 61 NGT individuals (23 were heterozygous (CT) or homozygous (TT) T allele carriers) and 43 participants with T2D (20 with CT/TT). Participants were previously examined by an oral glucose tolerance test (OGTT) and a subsequent isoglycemic intravenous glucose infusion (IIGI). The incretin effect was assessed by quantification of the difference in integrated beta cell secretory responses during an OGTT and IIGI. Glucose and hormonal levels were measured during experimental days, and from these, indices of beta cell function and insulin sensitivity were calculated. No genotype-specific differences in the incretin effect were observed in the NGT group (P = 0.70) or the T2D group (P = 0.68). NGT T allele carriers displayed diminished glucose-dependent insulinotropic polypeptide response during OGTT (P = 0.01) while T allele carriers with T2D were characterized by lower C-peptide AUC after OGTT (P = 0.04) and elevated glucose AUC after OGTT (P = 0.04). In conclusion, our findings do not exclude that this specific TCF7L2 variant increases the risk of developing T2D via diminished incretin effect, but genotype-related defects were not detectable in these cohorts.

Open access

Serena Martinelli, Mario Maggi, and Elena Rapizzi

Pheochromocytomas/paragangliomas (PPGLs) are rare neuroendocrine tumours linked to more than 15 susceptibility genes. PPGLs present with very different genotype/phenotype correlations. Certainly, depending on the mutated gene, and the activated intracellular signalling pathways, as well as their metastatic potential, each tumour is immensely different. One of the major challenges in in vitro research, whatever the study field, is to choose the best cellular model for that study. Unfortunately, most of the time there is not “a best” cell model. Thus, in order to avoid observations that could be related to and/or dependent on a specific cell line, researchers often perform the same experiments using different cell lines simultaneously. The situation is even more complicated when there are only very few cell models obtained in different species for a disease. This is the case for PPGLs. In this review, we will describe the characteristics of the different cell lines and of mouse models, trying to understand if there is one that is more appropriate to use, depending on which aspect of the tumours one is trying to investigate.

Open access

Hei Yi Vivian Pak, Andrew Lansdown, Peter Taylor, Dafydd Aled Rees, John Stephen Davies, and Caroline Hayhurst

Objective

Acromegaly is a rare condition and there is often a long path to diagnosis for many patients. We sought to explore patient’s perceptions and understanding of acromegaly, to examine the quality of communication and find gaps in the information provided at diagnosis.

Design

A prospective study using qualitative research methodology and grounded theory. A semi-structured interview was conducted with 18 patients treated for acromegaly in a single tertiary centre and verbatim transcripts were thematically analysed for overarching themes.

Results

Eighteen patients with acromegaly were interviewed. The mean age of participants was 52 (range 30–72). Four overarching themes emerged; (1) Patients rely on online resources to understand acromegaly in the time between diagnosis and tertiary care clinic; (2) There is not enough support available for patients; (3) Patients have a basic understanding of acromegaly and associated conditions, but the long-term impact is underestimated; and (4) Patients initially felt intimidated by the multidisciplinary team panel, but overall found it useful.

Conclusion

Acromegalic patients have a strong need for information at the point of initial diagnosis, in particular online resources and interaction with other experienced patients. Wider dissemination of patient educational resources into primary and secondary care settings may improve overall patient satisfaction, treatment adherence and subsequent health care provider–patient relationships.

Open access

Thomas Crezee, Mirela Petrulea, Doina Piciu, Martin Jaeger, Jan Wa Smit, Theo S Plantinga, Carmen E. Georgescu, and Romana Netea-Maier

The PI3K-Akt-mTOR pathway plays a central role in the development of non-medullary thyroid carcinoma (NMTC). Although somatic mutations have been identified in these genes in NMTC patients, the role of germline variants has not been investigated. Here, we selected frequently occurring genetic variants in AKT1, AKT2, AKT3, PIK3CA and MTOR and have assessed their effect on NMTC susceptibility, progression and clinical outcome in a Dutch discovery cohort (154 patients, 188 controls) and a Romanian validation cohort (159 patients, 260 controls). Significant associations with NMTC susceptibility were observed for AKT1 polymorphisms rs3803304, rs2494732 and rs2498804 in the Dutch discovery cohort, of which the AKT1 rs3803304 association was confirmed in the Romanian validation cohort. No associations were observed between PI3K-Akt-mTOR polymorphisms and clinical parameters including histology, TNM staging, treatment response and clinical outcome. Functionally, cells bearing the associated AKT1 rs3803304 risk allele exhibit increased levels of phosphorylated Akt protein, potentially leading to elevated signaling activity of the oncogenic Akt pathway. All together, germline encoded polymorphisms in the PI3K-Akt-mTOR pathway could represent important risk factors in development of NMTC.

Open access

Leticia Ribeiro de Oliveira, Carlos Alberto Longui, Guilherme Guaragna-Filho, Jose Luiz Costa, Rafael Lanaro, David Antonio Silva, Maria Izabel Chiamolera, Maricilda Palandi de Mello, Andre Moreno Morcillo, Andrea Trevas Maciel-Guerra, and Gil Guerra Júnior

Objective: Steroid measurement is a challenge in pediatric endocrinology. Currently, liquid chromatography with tandem mass spectrometry (LC-MS/MS) is considered a gold standard for this purpose. The aim of this study was to compare both LC-MS/MS and immunoassay (IA) for androgens before and after human recombinant chorionic gonadotropin (r-hCG) stimulus in children with 46,XY Disorders of Sex Development (DSD).

Methods: Nineteen patients with 46,XY DSD were evaluated; all of them were prepubertal and non gonadectomized. Testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA) and androstenedione were measured by IA and LC-MS/MS before and 7 days after rhCG injection. The correlation between IA and LC-MS/MS was analysed by the intraclass correlation coefficient (ICC) and Spearman's rank correlation coefficient (SCC). For concordance analysis the Passing and Bablok (PB) regression and the Bland and Altman (BA) method were used.

Results: Testosterone showed excellent correlation (ICC = 0.960 and SCC = 0.964); DHT showed insignificant and moderate correlations as indicated by ICC (0.222) and SCC (0.631), respectively; DHEA showed moderate correlation (ICC = 0.585 and SCC = 0.716); and androstenedione had poor and moderate correlations in ICC (0.363) and SCC (0.735), respectively. Using the PB method, all hormones showed a linear correlation, but proportional and systematic concordance errors were detected for androstenedione, systematic errors for testosterone and no errors for DHEA and DHT. By the BA method, there was a trend of IA to overestimate testosterone and androstenedione and underestimate DHEA and DHT when compared to LC-MS/MS.

Conclusion: Traditional IA should be replaced by LC-MS/MS for the androgens measurement in prepubertal children whenever is possible.

Open access

Xiaojie Wang, Zhiyuan Chen, Ziyi Li, Bo Chen, Yong Qi, Guowei Li, and Jonathan D Adachi

Background

Several epidemiological studies have demonstrated the risk factors for fall, while few studies investigated the association between frailty and risk of fall in diabetic patients aged ≥45 years.

Methods

In this multicity observational study, participants with type 2 diabetes aged ≥45 years were enrolled. Frailty status was measured by a frailty index (FI) of deficit accumulation. We used multivariable regression models to examine the relationship between frailty and fall in diabetic patients, and further investigated the associations between frailty and fall in varied subgroups.

Results

A total of 2049 participants with type 2 diabetes were identified in our study. Our results showed a per-s.d. and a per-0.01 increment of FI were associated with an increased risk of fall, with a fully adjusted OR of 1.89 (95% CI: 1.50, 2.38), 1.06 (95% CI: 1.04, 1.09), respectively. The effects were magnified when frailty was considered as dichotomous, with an OR of 3.08 (95% CI: 2.18, 4.34). In further subgroup analyses, we found that the females, the older, rural residents, individuals with no sitting toilet, people with poor balance performance and those in poor health status were susceptible to fall. Especially, for the risk of fall in the older, a per-s.d. increase of FI corresponded to an OR of 2.46 (95% CI: 1.68, 3.62). When frailty was regarded as a binary variable, the effect increased to 4.62 (95% CI: 2.54, 8.38) in the older subgroup.

Conclusion

Frailty was associated with a higher risk of fall in people with type 2 diabetes, and the effects were higher in vulnerable groups. This evidence suggested that more attention should be paid to vulnerable groups for fall prevention.

Open access

Ju-shuang Li, Tao Wang, Jing-jing Zuo, Cheng-nan Guo, Fang Peng, Shu-zheng Zhao, Hui-hui Li, Xiang-qing Hou, Yuan Lan, Ya-ping Wei, Chao Zheng, and Guang-yun Mao

Diabetic retinopathy (DR), the most common microvascular complication of diabetes and leading cause of visual impairment in adults worldwide, is suggested to be linked to abnormal lipid metabolism. The present study aims to comprehensively investigate the relationship between n-6 polyunsaturated fatty acids (PUFAs) and DR. This was a propensity score matching based case-control study, including 69 pairs of DR patients and type 2 diabetic patients without DR with mean age of 56.7 ± 9.2 years. Five n-6 PUFAs were determined by UPLC-ESI-MS / MS system. Principle component regression (PCR) and multiple conditional logistic regression models were used to investigate the association of DR risk with n-6 PUFAs depending on independent training and testing sets, respectively. According to locally weighted regression model, we observed obvious negative correlation between levels of five n-6 PUFAs (linoleic acid, γ-linolenic acid, eicosadienoic acid, dihomo-γ-linolenic acid and arachidonic acid) and DR. Based on multiple PCR model, we also observed significant negative association between the five n-6 PUFAs and DR with adjusted OR (95% CI) as 0.62 (0.43,0.87). When being evaluated depending on the testing set, the association was still existed, and PCR model had excellent classification performance, in which area under the curve (AUC) was 0.88 (95%CI: 0.78, 0.99). In addition, the model also had valid calibration with a non-significant Hosmer-Lemeshow Chi-square of 9.44 (P = 0.307) in the testing set. n-6 PUFAs were inversely associated with the presence of DR, and the principle component could be potential indicator in distinguishing DR from other T2D patients.

Open access

Pan Chen, Liqin Pan, Wensi Huang, Huijuan Feng, Wei Ouyang, Juqing Wu, Jing Wang, Yuying Deng, Jiaxin Luo, and Yanying Chen

Objective

To evaluate the relationship between the BRAF V600E mutation in lymph node metastasis (LNM) and its invasive characteristics in papillary thyroid cancer (PTC).

Material and methods

A total of 373 PTC patients were enrolled in this study conducted at Zhujiang Hospital of Southern Medical University between January 2017 and December 2018. PTCs with cervical lymph node metastases were verified pathohistologically, and primary tumors and LNM were examined for the BRAF V600E mutation. Patients were excluded from the study if the BRAF V600E mutation was examined only in primary tumors or only in LNM.

Results

Of the 373 patients examined, BRAF V600E mutation frequency in primary tumors was slightly higher than in LNM (81.5% vs 78.0%, P = 0.000), the intra-class correlation coefficient (ICC) was 0.865 (95% CI 0.835–0.890). The BRAF V600E mutation in both primary tumor and LNM negatively correlated with the size of the largest metastatic focus of LNM (Odds ratio, OR = 0.297, 95% CI 0.143–0.616, P = 0.001; OR = 0.242, 95% CI 0.119–0.492, P = 0.000, respectively). There was no relationship between BRAF V600E mutation in LNM and the number, extranodal extension or stage of LNM (P > 0.05).

Conclusion

The BRAF V600E mutation in LNM may not be related to the invasive characteristics of LNM in PTC.

Open access

Guido Zavatta and Bart L Clarke

The first adjunctive hormone therapy for chronic hypoparathyroidism, recombinant human parathyroid hormone (1–84) (rhPTH(1–84)) was approved by the FDA in January 2015. Since the approval of rhPTH(1–84), growing interest has developed in other agents to treat this disorder in both the scientific community and among pharmaceutical companies. For several reasons, conventional therapy with calcium and activated vitamin D supplementation, magnesium supplementation as needed, and occasionally thiazide-type diuretic therapy remains the mainstay of treatment, while endocrinologists and patients are constantly challenged by limitations of conventional treatment. Serum calcium fluctuations, increased urinary calcium, hyperphosphatemia, and a constellation of symptoms that limit mental and physical functioning are frequently associated with conventional therapy. Understanding how conventional treatment and hormone therapy work in terms of pharmacokinetics and pharmacodynamics is key to effectively managing chronic hypoparathyroidism. Multiple questions remain regarding the effectiveness of PTH adjunctive therapy in preventing or slowing the onset and progression of the classical complications of hypoparathyroidism, such as chronic kidney disease, calcium-containing kidney stones, cataracts, or basal ganglia calcification. Several studies point toward an improvement in the quality of life during replacement therapy. This review will discuss current clinical and research challenges posed by treatment of chronic hypoparathyroidism.

Key points:

  • Conventional therapy with calcium and activated forms of vitamin D are currently the mainstays of treatment for most patients with chronic hypoparathyroidism.
  • Hormone therapy can be administered through FDA-approved once-daily rhPTH(1–84), or off-label multiple-daily injections of teriparatide. The former is the only FDA-approved drug, with safety and efficacy supported by a randomized placebo-controlled trial and open-label long-term extension trial data.
  • Twice-daily teriparatide has been used in children safely for up to 10 years.
  • New pharmacological options that replace the deficient hormone wi ll likely be available within the next few years.
Open access

Raja Padidela, Moira S Cheung, Vrinda Saraff, and Poonam Dharmaraj

X-linked hypophosphataemia (XLH) is caused by a pathogenic variant in the PHEX gene, which leads to elevated circulating FGF23. High FGF23 causes hypophosphataemia, reduced active vitamin D concentration and clinically manifests as rickets in children and osteomalacia in children and adults. Conventional therapy for XLH includes oral phosphate and active vitamin D analogues but does not specifically treat the underlying pathophysiology of elevated FGF23-induced hypophosphataemia. In addition, adherence to conventional therapy is limited by frequent daily dosing and side effects such as gastrointestinal symptoms, secondary hyperparathyroidism and nephrocalcinosis. Burosumab, a recombinant human IgG1 MAB that binds to and inhibits the activity of FGF23, is administered subcutaneously every 2 weeks. In clinical trials (phase 2 and 3) burosumab was shown to improve phosphate homeostasis that consequently resolves the skeletal/non-skeletal manifestations of XLH. Burosumab was licensed in Europe (February 2018) with the National Institute for Health and Care Excellence, UK approving use within its marketing authorisation in October 2018. In this publication, the British Paediatric and Adolescent Bone Group (BPABG) reviewed current evidence and provide expert recommendations for care pathway and management of XLH with burosumab.