Metformin improves insulin sensitivity in insulin sensitive tissues such as liver, muscle and fat. However, the functional roles and the underlying mechanism of metformin action in pancreatic β cells remain elusive. Here we show that, under normal growth condition, metformin suppresses MIN6 β cell proliferation and promotes apoptosis via an AMPK-dependent and autophagy-mediated mechanism. On the other hand, metformin protects MIN6 cells against palmitic acid (PA)-induced apoptosis. Our findings indicate that metformin plays a dual role in β cell survival and overdose of this anti-diabetic drug itself may lead to potential β cell toxicity.

AimsCoronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and within a few months of the first outbreak, it was declared a global pandemic by the WHO. The lethal virus SARS-CoV-2 is transmitted through respiratory droplets and enters host cells through angiotensin-converting enzyme 2 (ACE-2) receptors. ACE-2 receptors are highly expressed in many tissues, including testes. Therefore, the objective of this study was to summarize the available literature regarding the correlation between sex hormone levels and COVID-19.MethodsThe PubMed, Web of Science, Embase, and Cochrane Library databases were reviewed systematically through August 2022 for studies comparing sex hormone levels between different patient groups: COVID-19 versus no COVID-19, more severe versus less severe COVID-19, and non-survivors versus survivors. Various types of clinical research reporting sex hormone levels, including free testosterone (FT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17β-oestradiol (E2), the oestradiol-to-testosterone ratio (E2/T), prolactin (PRL), and sex hormone-binding globulin (SHBG), were included. Random- or fixed-effects models were used to calculate weighted mean differences (WMDs) and 95% confidence intervals (CIs). Heterogeneity among the studies was assessed by the I2 index, and data analyses were performed using meta-analysis with Stata version 12.0.ResultsTwenty-two articles that included 3369 patients were ultimately included in the meta-analysis. According to analysis of the included studies, patients with COVID-19 had significantly low T/LH, FSH/LH, and SHBG levels and high levels of LH, and E2/T, but their levels of FT, FSH, PRL, E2, and progesterone were not affected. Publication bias was not found according to funnel plots and Egger’s regression and Begg’s rank correlation tests.ConclusionLow T/LH, FSH/LH, and SHBG serum levels and high LH, and E2/T levels may increase the risk of COVID-19. Additionally, the greater is the clinical severity of COVID-19, the higher is the probability of increases in LH, and E2/T serum levels and decreases in T/LH, FSH/LH, and SHBG levels. COVID-19 may have unfavourable effects on gonadal functions, which should be taken seriously by clinicians. Routine monitoring of sex hormone levels might help clinicians to evaluate disease severity in patients with COVID-19.

Background Radiofrequency ablation (RFA) is used to treat various cancers, but its use in thyroid cancer remains controversial. The aim of this study was to investigate surgical findings after RFA for papillary thyroid cancer (PTC). Material/Methods The study included 21 patients (average age 44.9±13.3 years) who had biopsy-confirmed thyroid cancer treated with RFA in multiple hospitals. Surgery was done in the First Hospital of China Medical University. Results The 21 patients had a total of 32 thyroid nodules that were treated with RFA. Twenty-eight nodules were malignant, and 4 nodules were benign. Before RFA, 17 of the malignant nodules were >1 cm and 11 were ≤1 cm. Among the 28 malignant nodules, post-ablation lesions adhered to or invaded the structures surrounding the thyroid in 17 (60.7%), 19 (67.9%), and 22 (78.6%) nodules evaluated with ultrasound, contrast-enhanced computed tomography, and intraoperatively, respectively. Based on pathology results, 7 (33.3%) of the 21 patients had bilateral cancer. Ten (47.6%) of the 21 patients had central lymph node metastasis and 2 (9.5%) had lateral lymph node metastasis. For 5 (15.6%) of the 32 nodules, the fine-needle aspiration results were not consistent with the postoperative pathological results. Five (23.8%) of the 21 patients with lymph node metastasis had clinically negative (CN0) lesions. Conclusions RFA for PTC primary lesions may be incomplete and leave residual lymph node metastasis, even in lesions ≤1 cm. RFA should be recommended with caution in the treatment of operable patients with primary PTC.

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