Faculty Bibliography

OBJECTIVE:COVID-19 infection may affect thyroid function. However, changes in thyroid function in COVID-19 patients have not been well described. This systematic review and meta-analysis assess thyroxine levels in COVID-19 patients, compared with non-COVID-19 pneumonia and healthy cohorts during the COVID-19 epidemic. METHODS:A search was performed in English and Chinese databases from inception to August 1, 2022. The primary analysis assessed thyroid function in COVID-19 patients, comparing non-COVID-19 pneumonia and healthy cohorts. Secondary outcomes included different severity and prognoses of COVID-19 patients. RESULTS:=0.003) and FT3 (SMD=0.51, P=0.001) than non-survivors. CONCLUSIONS:Compared with the healthy cohort, COVID-19 patients showed decreased TSH and FT3 and increased FT4, similar to non-COVID-19 pneumonia. Thyroid function changes were related to the severity of COVID-19. Thyroxine levels have clinical significance for prognosis evaluation, especially FT3.

The allure of tobacco smoking is linked to the instant gratification provided by inhaled nicotine. Unfortunately, tobacco curing and burning generates many mutagens including more than 70 carcinogens. There are two types of mutagens and carcinogens in tobacco smoke (TS): direct DNA damaging carcinogens and procarcinogens, which require metabolic activation to become DNA damaging. Recent studies provide three new insights on TS-induced DNA damage. First, two major types of TS DNA damage are induced by direct carcinogen aldehydes, cyclic-1,N²-hydroxy-deoxyguanosine (γ-OH-PdG) and α-methyl-1, N²-γ-OH-PdG, rather than by the procarcinogens, polycyclic aromatic hydrocarbons and aromatic amines. Second, TS reduces DNA repair proteins and activity levels. TS aldehydes also prevent procarcinogen activation. Based on these findings, we propose that aldehydes are major sources of TS induce DNA damage and a driving force for carcinogenesis. E-cigarettes (E-cigs) are designed to deliver nicotine in an aerosol state, without burning tobacco. E-cigarette aerosols (ECAs) contain nicotine, propylene glycol and vegetable glycerin. ECAs induce O⁶-methyl-deoxyguanosines (O⁶-medG) and cyclic γ-hydroxy-1,N²--propano-dG (γ-OH-PdG) in mouse lung, heart and bladder tissues and causes a reduction of DNA repair proteins and activity in lungs. Nicotine and nicotine-derived nitrosamine ketone (NNK) induce the same types of DNA adducts and cause DNA repair inhibition in human cells. After long-term exposure, ECAs induce lung adenocarcinoma and bladder urothelial hyperplasia in mice. We propose that E-cig nicotine can be nitrosated in mouse and human cells becoming nitrosamines, thereby causing two carcinogenic effects, induction of DNA damage and inhibition of DNA repair, and that ECA is carcinogenic in mice. Thus, this article reviews the newest literature on DNA adducts and DNA repair inhibition induced by nicotine and ECAs in mice and cultured human cells, and provides insights into ECA carcinogenicity in mice.

Epigenomic-wide DNA methylation profiling holds the potential to reflect both electronic cigarette exposure-associated risks and individual poor health outcomes. However, a systemic study in animals or humans is still lacking. Using the Infinium Mouse Methylation BeadChip, we examined the DNA methylation status of white blood cells in male ApoE-/- mice after 14 weeks of electronic cigarette exposure with the InExpose system (2 hr/day, 5 days/week, 50% PG and 50% VG) with low (6 mg/ml) and high (36 mg/ml) nicotine concentrations. Our results indicate that electronic cigarette aerosol inhalation induces significant alteration of 8,985 CpGs in a dose-dependent manner (FDR<0.05); 7,389 (82.2%) of the CpG sites are annotated with known genes. Among the top 6 significant CpG sites (P-value<1e-8), 4 CpG sites are located in the known genes, and most (3/5) of these genes have been related to cigarette smoking. The other two CpGs are close to/associated with the Phc2 gene that was recently linked to smoking in a transcriptome-wide associations study. Furthermore, the gene set enrichment analysis highlights the activation of MAPK and 4 cardiomyocyte/cardiomyopathy-related signaling pathways (including adrenergic signaling in cardiomyocytes and arrhythmogenic right ventricular cardiomyopathy) following repeated electronic cigarette use. The MAPK pathway activation correlates well with our finding of increased cytokine mRNA expression after electronic cigarette exposure in the same batch of mice. Interestingly, two pathways related to mitochondrial activities, namely mitochondrial gene expression and mitochondrial translation, are also activated after electronic cigarette exposure. Elucidating the relationship between these pathways and the increased circulating mitochondrial DNA observed here will provide further insight into the cell-damaging effects of prolonged inhalation of e-cigarette aerosols.

This collection of summaries on endoscopic diagnosis of Barrett's esophagus (BE) includes the best endoscopic markers of the extent of BE; the interpretation of the diagnosis of ultra-short BE; the criteria for endoscopic grading; the sensitivity and specificity of endoscopic diagnosis; capsule and magnifying endoscopy; narrow band imaging; balloon cytology; the distinction between focal and diffuse dysplasia; the techniques for endoscopic detection of dysplasia and the grading systems; and the difficulty of interpretation of inflammatory or regenerative changes

BACKGROUND: Hyalinizing trabecular adenoma (HTA) is an uncommon benign thyroid tumor that can present as a solitary thyroid nodule, a prominent nodule in a multinodular goiter, or as an incidental finding in a thyroidectomy specimen. The clinical significance of the lesion is that it is frequently misdiagnosed as papillary carcinoma on fine-needle aspiration cytology or as papillary or medullary carcinoma on histopathological section. We reviewed our recent experience with 7 patients diagnosed with HTA. METHODS: Fine-needle aspiration biopsy was performed in 7 patients presenting with a solitary thyroid nodule (n = 4) or a multinodular goiter (n = 3). The patients underwent total thyroidectomy (n = 6) or hemithyroidectomy (n = 1). RESULTS: In 4 patients, the preoperative cytology was suggestive of papillary carcinoma, in 2 patients suspicious, and in 1 patient positive for papillary carcinoma. On histopathological section, 2 patients had a microscopic HTA, 2 patients had HTA in 1 or 2 nodules of a multinodular goiter, and 3 patients had HTA in a solitary nodule. Except in 1 patient, who had a microscopic focus (3.2 mm) of papillary carcinoma, there was no evidence of malignancy in the surgical specimens on permanent histopathological section. CONCLUSIONS: Although HTA is a rare condition of the thyroid, the surgeon needs to be aware of this entity to be able to better discuss the pathological findings with the patient, particularly since some pathologists and endocrinologists believe that HTA may represent a malignant neoplasm of low metastatic potential