Moving into a new era of periodontal genetic studies: relevance of large case–control samples using severe phenotypes for genome‐wide association studies

Studies to elucidate the role of genetics as a risk factor for periodontal disease have gone through various phases. In the majority of cases, the initial ‘hypothesis‐dependent’ candidate‐gene polymorphism studies did not report valid genetic risk loci. Following a large‐scale replication study, these initially positive results are believed to be caused by type 1 errors. However, susceptibility genes, such as CDKN2BAS (Cyclin Dependend KiNase 2B AntiSense RNA; alias ANRIL [ANtisense Rna In the Ink locus]), glycosyltransferase 6 domain containing 1 (GLT6D1) and cyclooxygenase 2 (COX2), have been reported as conclusive risk loci of periodontitis. The search for genetic risk factors accelerated with the advent of ‘hypothesis‐free’ genome‐wide association studies (GWAS). However, despite many different GWAS being performed for almost all human diseases, only three GWAS on periodontitis have been published – one reported genome‐wide association of GLT6D1 with aggressive periodontitis (a severe phenotype of periodontitis), whereas the remaining two, which were performed on patients with chronic periodontitis, were not able to find significant associations. This review discusses the problems faced and the lessons learned from the search for genetic risk variants of periodontitis. Current and future strategies for identifying genetic variance in periodontitis, and the importance of planning a well‐designed genetic study with large and sufficiently powered case–control samples of severe phenotypes, are also discussed.     

Gracilaria changii(Rhodophyta) alleviates bisphenol A-induced adverse reproductive abnormalities in mice

Objective: To evaluate the potential of Gracilaria changii extract in ameliorating the potential adverse effects of bisphenol A. Methods: The antioxidant capacity of Gracilaria changii extracted using different solvents(methanol, ethanol, and aqueous) was studied. The mice were administered by oral gavage with bisphenol A(60 mg/kg body weight) for 6 weeks with or without Gracilaria changii aqueous extract. Thereafter, the mice were either euthanized for histology and immunohistochemistry studies or mated to evaluate the pregnancy rate. Results: Gracilaria changii aqueous extract showed the highest antioxidant properties compared with extract using methanol and ethanol. The aqueous extract of Gracilaria changii improved the uterus index and uterine lipid peroxidation after bisphenol A exposure, although the uterine expressions of estrogen receptors and complement C3 were not improved. Histological evaluation of the uterus during the estrus stage has revealed that the extract could mitigate bisphenol A-induced adverse effects in the uterus as there was a lower percentage of mice showing abnormalities like decreased eosin staining in the myometrium, and decrease in the number of eosinophil and endometrial glands in the endometrium. Besides, Gracilaria changii aqueous extract improved the pregnancy rate of mice administered with bisphenol A. Conclusions: Gracilaria changii extract protects against bisphenol A-induced female reproductive abnormalities in mice which may be mediated via modulation of eosinophil migration, endometrial gland formation, and protein expressions associated with prostaglandins in the myometrium.     

Clinical and economic outcomes of a multidisciplinary team approach in a lower extremity amputation prevention programme for diabetic foot ulcer care in an Asian population: A case‐control study

Present guidelines recommend a multidisciplinary team (MDT) approach to diabetic foot ulcer (DFU) care, but relevant data from Asia are lacking. We aim to evaluate the clinical and economic outcomes of an MDT approach in a lower extremity amputation prevention programme (LEAPP) for DFU care in an Asian population. We performed a case‐control study of 84 patients with DFU between January 2017 and October 2017 (retrospective control) vs 117 patients with DFU between December 2017 and July 2018 (prospective LEAPP cohort). Comparing the clinical outcomes between the retrospective cohort and the LEAPP cohort, there was a significant decrease in mean time from referral to index clinic visit (38.6 vs 9.5 days, P < .001), increase in outpatient podiatry follow‐up (33% vs 76%, P < .001), decrease in 1‐year minor amputation rate (14% vs 3%, P = .007), and decrease in 1‐year major amputation rate (9% vs 3%, P = .05). Simulation of cost avoidance demonstrated an annualised cost avoidance of USD $1.86m (SGD $2.5m) for patients within the LEAPP cohort. In conclusion, similar to the data from Western societies, an MDT approach in an Asian population, via a LEAPP for patients with DFU, demonstrated a significant reduction in minor and major amputation rates, with annualised cost avoidance of USD $1.86m.     

Managing complications of radiation therapy in head and neck cancer patients: Part II. Management of radiation-induced caries

Head and neck cancer is becoming a more recognizable pathology to the general population and dentists. The modes of treatment include surgery and/or radiation therapy. Where possible, pretreatment dental assessment shall be provided for these patients before they undergo radiation therapy. There are occasions, however, whereby head and neck cancer patients are not prepared optimally for radiation therapy. Because of this, they succumb to complicated oral complications after radiation therapy. The management of xerostomia has been reviewed in Part I of this series. In this article, the management of dental caries, a sequalae of xerostomia following radiation therapy is reviewed.     

Lobectomy and Prophylactic Central Neck Dissection for Papillary Thyroid Microcarcinoma: Do Involved Lymph Nodes Mandate Completion Thyroidectomy?

Background

The present study was designed to investigate the necessity of completion thyroidectomy for patients who underwent thyroid lobectomy for low-risk papillary thyroid microcarcinoma (PTMC) that was later pathologically diagnosed as central lymph node (CLN) metastasis.

Methods

Between 1986 and 2001, we assessed 551 patients who underwent thyroidectomy with prophylactic ipsilateral central compartment neck dissection, and 409 patients were followed-up completely. Thyroid lobectomy were performed in 281 and 128 patients, respectively. The patients were divided into two groups according to CLN metastasis. Clinicopathological profiles and follow-up details were investigated by retrospective chart review.

Results

The CLN-positive and -negative groups were comprised of 43 (15.2 %) and 238 patients (84.8 %), respectively. The mean ages of the two groups were not significantly different (p > 0.05). The mean tumor size of the CLN-positive group (6.8 mm) was significantly larger than that of the CLN-negative group (5.6 mm; p < 0.05). Microscopic capsular invasion was significantly higher in the CLN-positive group (51.2 vs. 23.9 %; p < 0.05). Overall, 21 patients (7.4 %, 21/281) experienced recurrence. Among these, 2 (4.7 %, 2/43) and 19 (8.0 %, 19/238) were in the CLN-positive and -negative groups, respectively. There was no significant correlation between CLN metastasis and tumor recurrence.

Conclusions

Postoperative recurrence was lower in the CLN-positive group, and there was no significant correlation between CLN metastasis and tumor recurrence. Our results suggest that it is not necessary to perform completion thyroidectomy for PTMC patients who have undergone thyroid lobectomy and who have been pathologically diagnosed with CLN metastasis.     

Risk Prediction Model Based on Magnetic Resonance Elastography-Assessed Liver Stiffness for Predicting Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma

Background/AimsPosthepatectomy liver failure (PHLF) is a major complication that increases mortality in patients with hepatocellular carcinoma after surgical resection. The aim of this retrospective study was to evaluate the utility of magnetic resonance elastography-assessed liver stiffness (MRE-LS) for the prediction of PHLF and to develop an MRE-LS-based risk prediction model.MethodsA total of 160 hepatocellular carcinoma patients who underwent surgical resection with available preoperative MRE-LS data were enrolled. Clinical and laboratory parameters were collected from medical records. Logistic regression analyses were conducted to identify the risk factors for PHLF and develop a risk prediction model.ResultsPHLF was present in 24 patients (15%). In the multivariate logistic analysis, high MRE-LS (kPa; odds ratio [OR] 1.49, 95% confidence interval [CI] 1.12 to 1.98, p=0.006), low serum albumin (≤3.8 g/dL; OR 15.89, 95% CI 2.41 to 104.82, p=0.004), major hepatic resection (OR 4.16, 95% CI 1.40 to 12.38, p=0.014), higher albumin-bilirubin score (>–0.55; OR 3.72, 95% CI 1.15 to 12.04, p=0.028), and higher serum α-fetoprotein (>100 ng/mL; OR 3.53, 95% CI 1.20 to 10.40, p=0.022) were identified as independent risk factors for PHLF. A risk prediction model for PHLF was established using the multivariate logistic regression equation. The area under the receiver operating characteristic curve (AUC) of the risk prediction model was 0.877 for predicting PHLF and 0.923 for predicting grade B and C PHLF. In leave-one-out cross-validation, the risk model showed good performance, with AUCs of 0.807 for all-grade PHLF and 0. 871 for grade B and C PHLF.ConclusionsOur novel MRE-LS-based risk model had excellent performance in predicting PHLF, especially grade B and C PHLF.