Effects of ghrelin on the structural complexity of exocrine pancreas tissue architecture

Fractal nature of human gastrointestinal system: Exploring a new era

The morphological complexity of cells and tissues, whether normal or pathological, is characterized by two primary attributes: Irregularity and self-similarity across different scales. When an object exhibits self-similarity, its shape remains unchanged as the scales of measurement vary because any part of it resembles the whole. On the other hand, the size and geometric characteristics of an irregular object vary as the resolution increases, revealing more intricate details. Despite numerous attempts, a reliable and accurate method for quantifying the morphological features of gastrointestinal organs, tissues, cells, their dynamic changes, and pathological disorders has not yet been established. However, fractal geometry, which studies shapes and patterns that exhibit self-similarity, holds promise in providing a quantitative measure of the irregularly shaped morphologies and their underlying self-similar temporal behaviors. In this context, we explore the fractal nature of the gastrointestinal system and the potential of fractal geometry as a robust descriptor of its complex forms and functions. Additionally, we examine the practical applications of fractal geometry in clinical gastroenterology and hepatology practice.

Pancreas-visceral fat CT value ratio and serrated pancreatic contour are strong predictors of postoperative pancreatic fistula after pancreaticojejunostomy

BACKGROUND

Our aim is to elucidate the true preoperative risk factors for postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD), making it possible to select POPF high-risk patients preoperatively regardless of intraoperative pancreatic consistency judged by the surgeon's hand.

METHODS

Among the 298 patients who underwent PD with pancreaticojejunostomy from 2007 to 2016, 262 patients had preoperative CT configurations that could be precisely evaluated. Risk factor analyses were conducted using various perioperative factors, including preoperative CT findings, such as CT values of the pancreas, pancreas-visceral fat CT value ratio and pancreatic outer contour. Pancreatic outer contour was further divided into smooth- (smooth interlobular) and serrated-type contours (feathery, irregular interlobular) by preoperative CT.

RESULTS

In terms of the incidence of POPF, among the 262 patients, POPF grade B/C was found in 27 (10.3%): grade B in 23 (8.8%) and grade C in 4 (1.5%). According to multivariate analysis, a high pancreas-visceral fat CT value ratio (p = 0.002), serrated-type contour (p = 0.02) and no history of chemoradiotherapy (p = 0.019) were identified as independent risk factors for POPF grade B/C. Even in patients with soft pancreas, the incidence of POPF grade B/C was 0% (0/57) in patients with a pancreas-visceral fat CT value ratio of less than - 0.4 and smooth-type contour, whereas the incidence was markedly high (45.0%, 9/20) in patients with a pancreas-visceral fat CT value ratio of - 0.4 or greater and serrated-type contour, indicating that patients with soft pancreas should be categorized into POPF high-risk and low-risk groups according to preoperative CT scan results.

CONCLUSIONS

The pancreas-visceral fat CT value ratio and serrated-type pancreas are useful markers to preoperatively identify true POPF high-risk groups in patients undergoing PD, regardless of the pancreatic texture judged intraoperatively.

Differences in Chromatin Texture and Nuclear Fractal Dimension Between Hashimoto's and Lymphocytic Thyroiditis Lymphocytes

Previous evidence suggested that lymphocytic thyroiditis (LT) was a variant of Hashimoto's thyroiditis (HT), thus the aim of the current study is to quantify structural changes in histological specimens taken from HT and LT patients. A total of 600 images containing a single lymphocyte nucleus (300 nuclei per group) were obtained from 20 patients with HT and LT. In order to quantify changes in the nuclear architecture of investigated lymphocytes, the fractal dimension (FD) and some gray-level co-occurrence matrix texture parameters (angular second moment, inverse difference moment, contrast, entropy, and correlation) were calculated for each nucleus. A statistically significant difference in the FD of the "binary-outlined" nucleus and that of the corresponding "black-and-white" nucleus was detected between HT and LT lymphocyte nuclei. In addition, there was also a statistically significant difference in contrast and correlation between HT and LT lymphocyte nuclei. In conclusion, the results of this study suggested that there was a difference in structural complexity between investigated lymphocyte nuclei; additionally, LT lymphocytes possessed probably more complex texture and larger variations as well as more asymmetrical nuclei compared with HT lymphocytes. Accordingly, these findings indicate that LT is probably not a variant of HT; however, more complex studies are necessary to estimate differences between these types of thyroiditis.

Morphology of the pancreas in type 2 diabetes: effect of weight loss with or without normalisation of insulin secretory capacity

AIMS/HYPOTHESIS

This study was designed to establish whether the low volume and irregular border of the pancreas in type 2 diabetes would be normalised after reversal of diabetes.

METHODS

A total of 29 individuals with type 2 diabetes undertook a very low energy (very low calorie) diet for 8 weeks followed by weight maintenance for 6 months. Methods were established to quantify the pancreas volume and degree of irregularity of the pancreas border. Three-dimensional volume-rendering and fractal dimension (FD) analysis of the MRI-acquired images were employed, as was three-point Dixon imaging to quantify the fat content.

RESULTS

There was no change in pancreas volume 6 months after reversal of diabetes compared with baseline (52.0 ± 4.9 cm(3) and 51.4 ± 4.5 cm(3), respectively; p = 0.69), nor was any volumetric change observed in the non-responders. There was an inverse relationship between the volume and fat content of the pancreas in the total study population (r =-0.50, p = 0.006). Reversal of diabetes was associated with an increase in irregularity of the pancreas borders between baseline and 8 weeks (FD 1.143 ± 0.013 and 1.169 ± 0.006, respectively; p = 0.05), followed by a decrease at 6 months (1.130 ± 0.012, p = 0.006). On the other hand, no changes in FD were seen in the non-reversed group.

CONCLUSIONS/INTERPRETATION

Restoration of normal insulin secretion did not increase the subnormal pancreas volume over 6 months in the study population. A significant change in irregularity of the pancreas borders occurred after acute weight loss only after reversal of diabetes. Pancreas morphology in type 2 diabetes may be prognostically important, and its relationship to change in beta cell function requires further study.

Fractal dimension and lacunarity of tumor microscopic images as prognostic indicators of clinical outcome in early breast cancer

AIM

Research in the field of breast cancer outcome prognosis has been focused on molecular biomarkers, while neglecting the discovery of novel tumor histology structural clues. We thus aimed to improve breast cancer prognosis by fractal analysis of tumor histomorphology.

PATIENTS & METHODS

This retrospective study included 92 breast cancer patients without systemic treatment.

RESULTS

Fractal dimension and lacunarity of the breast tumor microscopic histology possess prognostic value comparable to the major clinicopathological prognostic parameters.

CONCLUSION

Fractal analysis was performed for the first time on routinely produced archived pan-tissue stained primary breast tumor sections, indicating its potential for clinical use as a simple and cost-effective prognostic indicator of distant metastasis risk to complement the molecular approaches for cancer risk prognosis.

Gray-Level Co-Occurrence Matrix Texture Analysis of Breast Tumor Images in Prognosis of Distant Metastasis Risk

Owing to exceptional heterogeneity in the outcome of invasive breast cancer it is essential to develop highly accurate prognostic tools for effective therapeutic management. Based on this pressing need, we aimed to improve breast cancer prognosis by exploring the prognostic value of tumor histology image analysis. Patient group (n=78) selection was based on invasive breast cancer diagnosis without systemic treatment with a median follow-up of 147 months. Gray-level co-occurrence matrix texture analysis was performed retrospectively on primary tumor tissue section digital images stained either nonspecifically with hematoxylin and eosin or specifically with a pan-cytokeratin antibody cocktail for epithelial malignant cells. Univariate analysis revealed stronger association with metastasis risk by texture analysis when compared with clinicopathological parameters. The combination of individual clinicopathological and texture variables into composite scores resulted in further powerful enhancement of prognostic performance, with an accuracy of up to 90%, discrimination efficiency by the area under the curve [95% confidence interval (CI)] of 0.94 (0.87-0.99) and hazard ratio (95% CI) of 20.1 (7.5-109.4). Internal validation was successfully performed by bootstrap and split-sample cross-validation, suggesting that the models are generalizable. Whereas further validation is needed on an external set of patients, this preliminary study indicates the potential use of primary breast tumor histology texture as a highly accurate, simple, and cost-effective prognostic indicator of distant metastasis risk.