Diagnostic implication of thyroid spherules for cytological diagnosis of thyroid nodules

OBJECTIVE

Thyroid fine-needle aspiration (FNA) is a principal diagnostic procedure for thyroid nodules. A specific cytomorphological structure, known as the thyroid spherule, is often seen in FNA specimens. The clinical significance of these spherules in terms of diagnosis and prevalence remains largely unexplored.

METHODS

We performed a retrospective study on 310 thyroid FNA specimens and categorized them according to the Bethesda System for Reporting Thyroid Cytopathology. The presence, size and number of thyroid spherules in each specimen were examined and these data were subsequently correlated with the clinicopathological features.

RESULTS

Thyroid spherules were almost exclusively detected in benign cases, comprising 7.6% of all benign diagnoses. The average diameter of spherules in benign cases was 84.9 μm. Benign cases and cases with atypia of undetermined significance cases primarily exhibited low cellularity, while follicular neoplasms and malignant cases typically showed moderate to high cellularity. In the subgroup of FNA cases with moderate to high cellularity, spherules were identified in 12 (20%) of 59 benign FNA cases. Within this group, the sensitivity and specificity of thyroid spherules for detecting benign FNA cases were 20% and 100%, respectively.

CONCLUSIONS

Our results suggest that the presence of thyroid spherules in FNA specimens can serve as a highly specific marker for benign thyroid conditions. The prevalence of spherule detection is strongly influenced by the cellularity. In cases with moderate to high cellularity, the identification of spherules can assist the cytopathologists in diagnosing thyroid FNA cases as benign.

Reference intervals for bone marrow cells in juvenile and young adult cats bone marrow cytology

BACKGROUND

The current bone marrow (BM) reference intervals (RI) are based on a limited number of cats. Age-related changes in BM variables might be important, possibly affecting the interpretation of the results.

OBJECTIVES

Establish BM cytologic reference intervals (RIs) and association of age and sex on these findings, in healthy juvenile and young adult cats.

METHODS

BM aspirates of cats deemed healthy based on history and clinical, CBC, serum chemistry findings, and negative retrovirus serology were obtained and examined cytologically. The examination included a 1000-nucleated differential cell count and cell morphologic assessment. RIs were calculated using parametric, robust, and nonparametric methods. The cytologic findings were examined for associations with sex and age.

RESULTS

The study included 40 cats (females, 22 [55%]; males, 18 [45%]) with a median age of 1.5 years (range 0.5-5). Most calculated RIs were similar to those previously reported. BM plasma cell and monocyte counts were weakly and positively correlated with age (rs, .312 and .373, respectively; P < .05). Metarubricytes were higher in females (mean, 25.1%; SD, 6.0%) than males (mean, 21.2%; SD, 6.0%; P < .05).

CONCLUSIONS

The BM differential cell counts determined in this study can serve as RIs for cats aged 0.5-5 years.

Development of an Artificial-Intelligence-Based Tool for Automated Assessment of Cellularity in Bone Marrow Biopsies in Ph-Negative Myeloproliferative Neoplasms

The cellularity assessment in bone marrow biopsies (BMBs) for the diagnosis of Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPNs) is a key diagnostic feature and is usually performed by the human eyes through an optical microscope with consequent inter-observer and intra-observer variability. Thus, the use of an automated tool may reduce variability, improving the uniformity of the evaluation. The aim of this work is to develop an accurate AI-based tool for the automated quantification of cellularity in BMB histology. A total of 55 BMB histological slides, diagnosed as Ph- MPN between January 2018 and June 2023 from the archives of the Pathology Unit of University "Luigi Vanvitelli" in Naples (Italy), were scanned on Ventana DP200 or Epredia P1000 and exported as whole-slide images (WSIs). Fifteen BMBs were randomly selected to obtain a training set of AI-based tools. An expert pathologist and a trained resident performed annotations of hematopoietic tissue and adipose tissue, and annotations were exported as .tiff images and .png labels with two colors (black for hematopoietic tissue and yellow for adipose tissue). Subsequently, we developed a semantic segmentation model for hematopoietic tissue and adipose tissue. The remaining 40 BMBs were used for model verification. The performance of our model was compared with an evaluation of the cellularity of five expert hematopathologists and three trainees; we obtained an optimal concordance between our model and the expert pathologists' evaluation, with poorer concordance for trainees. There were no significant differences in cellularity assessments between two different scanners.

Comparison of reduced field-of-view DWI and conventional DWI techniques for the assessment of lumbar bone marrow infiltration in patients with acute leukemia

Objectives

To compare the imaging quality, apparent diffusion coefficient (ADC), and the value of assessing bone marrow infiltration between reduced field-of-view diffusion-weighted imaging (r-FOV DWI) and conventional DWI in the lumbar spine of acute leukemia (AL).

Methods

Patients with newly diagnosed AL were recruited and underwent both r-FOV DWI and conventional DWI in the lumbar spine. Two radiologists evaluated image quality scores using 5-Likert-type scales qualitatively and measured signal-to-noise ratio (SNR), contrast-to-noise (CNR), signal intensity ratio (SIR), and ADC quantitatively. Patients were divided into hypo- and normocellular group, moderately hypercellular group, and severely hypercellular group according to bone marrow cellularity (BMC) obtained from bone marrow biopsies. The image quality parameters and ADC value between the two sequences were compared. One-way analysis of variance followed by LSD post hoc test was used for the comparisons of the ADC values among the three groups. The performance of ADC obtained with r-FOV DWI (ADCr) and conventional DWI(ADCc) in evaluating BMC and their correlations with BMC and white blood cells (WBC) were analyzed and compared.

Results

71 AL patients (hypo- and normocellular: n=20; moderately hypercellular: n=19; severely hypercellular: n=32) were evaluated. The image quality scores, CNR, SIR, and ADC value of r-FOV DWI were significantly higher than those of conventional DWI (all p<0.05), and the SNR of r-FOV DWI was significantly lower (p<0.001). ADCr showed statistical differences in all pairwise comparisons among the three groups (all p<0.05), while ADCc showed significant difference only between hypo- and normocellular group and severely hypercellular group (p=0.014). The performance of ADCr in evaluating BMC (Z=2.380, p=0.017) and its correlations with BMC (Z=-2.008, p = 0.045) and WBC (Z=-2.022, p = 0.043) were significantly higher than those of ADCc.

Conclusion

Compared with conventional DWI, r-FOV DWI provides superior image quality of the lumbar spine in AL patients, thus yielding better performance in assessing bone marrow infiltration.

Towards detection of early response in neoadjuvant chemotherapy of breast cancer using Bayesian intravoxel incoherent motion

Introduction

The early identification of good responders to neoadjuvant chemotherapy (NACT) holds a significant potential in the optimal treatment of breast cancer. A recent Bayesian approach has been postulated to improve the accuracy of the intravoxel incoherent motion (IVIM) model for clinical translation. This study examined the prediction and early sensitivity of Bayesian IVIM to NACT response.

Materials and methods

Seventeen female patients with breast cancer were scanned at baseline and 16 patients were scanned after Cycle 1. Tissue diffusion and perfusion from Bayesian IVIM were calculated at baseline with percentage change at Cycle 1 computed with reference to baseline. Cellular proliferative activity marker Ki-67 was obtained semi-quantitatively with percentage change at excision computed with reference to core biopsy.

Results

The perfusion fraction showed a significant difference (p = 0.042) in percentage change between responder groups at Cycle 1, with a decrease in good responders [-7.98% (-19.47-1.73), n = 7] and an increase in poor responders [10.04% (5.09-28.93), n = 9]. There was a significant correlation between percentage change in perfusion fraction and percentage change in Ki-67 (p = 0.042). Tissue diffusion and pseudodiffusion showed no significant difference in percentage change between groups at Cycle 1, nor was there a significant correlation against percentage change in Ki-67. Perfusion fraction, tissue diffusion, and pseudodiffusion showed no significant difference between groups at baseline, nor was there a significant correlation against Ki-67 from core biopsy.

Conclusion

The alteration in tumour perfusion fraction from the Bayesian IVIM model, in association with cellular proliferation, showed early sensitivity to good responders in NACT.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03501394, identifier NCT03501394.

MarrowQuant 2.0: A Digital Pathology Workflow Assisting Bone Marrow Evaluation in Experimental and Clinical Hematology

Bone marrow (BM) cellularity assessment is a crucial step in the evaluation of BM trephine biopsies for hematologic and nonhematologic disorders. Clinical assessment is based on a semiquantitative visual estimation of the hematopoietic and adipocytic components by hematopathologists, which does not provide quantitative information on other stromal compartments. In this study, we developed and validated MarrowQuant 2.0, an efficient, user-friendly digital hematopathology workflow integrated within QuPath software, which serves as BM quantifier for 5 mutually exclusive compartments (bone, hematopoietic, adipocytic, and interstitial/microvasculature areas and other) and derives the cellularity of human BM trephine biopsies. Instance segmentation of individual adipocytes is realized through the adaptation of the machine-learning-based algorithm StarDist. We calculated BM compartments and adipocyte size distributions of hematoxylin and eosin images obtained from 250 bone specimens, from control subjects and patients with acute myeloid leukemia or myelodysplastic syndrome, at diagnosis and follow-up, and measured the agreement of cellularity estimates by MarrowQuant 2.0 against visual scores from 4 hematopathologists. The algorithm was capable of robust BM compartment segmentation with an average mask accuracy of 86%, maximal for bone (99%), hematopoietic (92%), and adipocyte (98%) areas. MarrowQuant 2.0 cellularity score and hematopathologist estimations were highly correlated (R² = 0.92-0.98, intraclass correlation coefficient [ICC] = 0.98; interobserver ICC = 0.96). BM compartment segmentation quantitatively confirmed the reciprocity of the hematopoietic and adipocytic compartments. MarrowQuant 2.0 performance was additionally tested for cellularity assessment of specimens prospectively collected from clinical routine diagnosis. After special consideration for the choice of the cellularity equation in specimens with expanded stroma, performance was similar in this setting (R² = 0.86, n = 42). Thus, we conclude that these validation experiments establish MarrowQuant 2.0 as a reliable tool for BM cellularity assessment. We expect this workflow will serve as a clinical research tool to explore novel biomarkers related to BM stromal components and may contribute to further validation of future digitalized diagnostic hematopathology workstreams.

Resilience of Neural Cellularity to the Influence of Low Educational Level

BACKGROUND

Education is believed to contribute positively to brain structure and function, as well as to cognitive reserve. One of the brain regions most impacted by education is the medial temporal lobe (MTL), a region that houses the hippocampus, which has an important role in learning processes and in consolidation of memories, and is also known to undergo neurogenesis in adulthood. We aimed to investigate the influence of education on the absolute cell numbers of the MTL (comprised by the hippocampal formation, amygdala, and parahippocampal gyrus) of men without cognitive impairment.

METHODS

The Isotropic Fractionator technique was used to allow the anisotropic brain tissue to be transformed into an isotropic suspension of nuclei, and therefore assess the absolute cell composition of the MTL. We dissected twenty-six brains from men aged 47 to 64 years, with either low or high education.

RESULTS

A significant difference between groups was observed in brain mass, but not in MTL mass. No significant difference was found between groups in the number of total cells, number of neurons, and number of non-neuronal cells. Regression analysis showed that the total number of cells, number of neurons, and number of non-neuronal cells in MTL were not affected by education.

CONCLUSIONS

The results indicate a resilience of the absolute cellular composition of the MTL of typical men to low schooling, suggesting that the cellularity of brain regions is not affected by formal education.

Lipid metabolism mRNA expression and cellularity of intramuscular adipocytes within the Longissimus muscle of Angus- and Wagyu-sired cattle fed for a similar days on feed or body weight endpoint

This study investigates intramuscular (IM) adipocyte development in the Longissimus muscle (LM) between Wagyu- and Angus-sired steers compared at a similar age and days on feed (D) endpoint or similar body weight (B) endpoint by measuring IM adipocyte cell area and lipid metabolism mRNA expression. Angus-sired steers (AN, n = 6) were compared with steers from two different Wagyu sires (WA), selected for either growth (G) or marbling (M), to be compared at a similar days on feed (DOF; 258 ± 26.7 d; WA-GD, n = 5 and WA-MD, n = 5) in Exp. 1 or body weight (BW; 613 ± 18.0 kg; WA-GB, n = 4 and WA-MB, n = 5) in Exp. 2, respectively. In Exp. 1, WA-MD steers had a greater (P ≤ 0.01) percentage of IM fat in the LM compared with AN and WA-GD steers. In Exp. 2, WA-MB steers had a greater (P ≤ 0.01) percentage of IM fat in the LM compared with AN and WA-GB steers. The distribution of IM adipocyte area was unimodal at all biopsy collections, with IM adipocyte area becoming progressively larger as cattle age (P ≤ 0.01) and BW increased (P ≤ 0.01). Peroxisome proliferator activated receptor delta (PPARd) was upregulated earlier for WA-MD and WA-MB cattle compared with other steers at a similar DOF and BW (P ≤ 0.02; treatment × biopsy interaction). Peroxisome proliferator activated receptor gamma was upregulated (PPARg) at a lesser BW for WA-MB steers (P = 0.09; treatment × biopsy interaction), while WA-MD steers had a greater (P ≤ 0.04) overall mean PPARg mRNA expression compared with other steers. Glycerol-3-phosphate acyltransferase, lipin 1, and hormone sensitive lipase demonstrated mRNA expression patterns similar to PPARg and PPARd or CCAAT enhancer binding protein beta, which emphasizes their importance in marbling development and growth. Additionally, WA-MD and WA-MB steers often had a greater early mRNA expression of fatty acid transporters (fatty acid transport protein 1; P < 0.02; treatment × biopsy interaction) and binding proteins (fatty acid binding protein 4) compared with other steers. Cattle with a greater marbling propensity appear to upregulate adipogenesis at a younger chronological and physiological maturity through PPARd, PPARg, and possibly adipogenic regulating compounds, lysophosphatidic acid, and diacylglycerol. These genes and compounds could be used as potential markers for marbling propensity of cattle in the future.

Hematopoietic Stem Cell-Derived Adipocytes Modulate Adipose Tissue Cellularity, Leptin Production and Insulin Responsiveness in Female Mice

A subpopulation of adipocytes in the major adipose depots of mice is produced from hematopoietic stem cells rather than mesenchymal progenitors that are the source of conventional white and brown/beige adipocytes. To analyze the impact of hematopoietic stem cell-derived adipocytes (HSCDAs) in the adipose niche we transplanted HSCs in which expression of a diphtheria toxin gene was under the control of the adipocyte-specific adiponectin gene promoter into irradiated wild type recipients. Thus, only adipocytes produced from HSC would be ablated while conventional white and brown adipocytes produced from mesenchymal progenitor cells would be spared. Wild type mice transplanted with HSCs from mice containing a reporter gene, but not the diphtheria toxin gene, regulated by the adiponectin gene promoter served as controls. In mice in which HSCDA production was suppressed, adipocyte size declined while adipose depot weights were unchanged and the number of conventional adipocyte progenitors significantly increased. We also measured a paradoxical increase in circulating leptin levels while physical activity was significantly decreased in the HSCDA depleted mice. Finally, insulin sensitivity was significantly reduced in HSCDA depleted mice. In contrast, loss of HSCDA production had no effect on body weight, components of energy balance, or levels of several circulating adipokines and tissue-resident inflammatory cells. These data indicate that ablation of this low-abundance subpopulation of adipocytes is associated with changes in circulating leptin levels and leptin-regulated endpoints associated with adipose tissue function. How they do so remains a mystery, but our results highlight the need for additional studies to explore the role of HSCDAs in other physiologic contexts such as obesity, metabolic dysfunction or loss of sex hormone production.

High-Resolution Diffusion-Weighted Imaging of C6 Glioma on a 7T BioSpec MRI Scanner: Correlation of Tumor Cellularity and Nuclear-to-Cytoplasmic Ratio with Apparent Diffusion Coefficient

RATIONALE AND OBJECTIVES

To determine the association of the apparent diffusion coefficient (ADC) with quantitative cellularity and the nuclear-to-cytoplasmic ratio in C6 glioma.

MATERIALS AND METHODS

Animal models bearing C6 gliomas underwent MR scans with T1 rapid acquisition with relaxation enhancement (RARE), T2 RARE, and high-resolution diffusion-weighted imaging sequences. For each model, three consecutive sections were used to draw regions of interest (ROIs) and measure ADC values; the middle section was localized in the plane with the maximal solid tumor area. The minimal, mean, and maximal ADC values were recorded for each ROI. GFAP-immunostained sections coregistered with ADC measurements were used to calculate tumor cellularity and the nuclear-to-cytoplasmic (N/C) ratio. Spearman's correlation was used to assess the relationship between ADC values and quantitative tumor cellularity as well as N/C ratios with a significance level of p < 0.05.

RESULTS

Thirty-three sections from 11 glioma-bearing rats were analyzed. The median values of the minimal, mean, and maximal ADC were 0.443 × 10^-3, 0.744 × 10^-3, and 1.140 × 10^-3 mm²/s, respectively. The median cellularity and N/C ratio were 2151.234 per 0.025 mm² and 0.857, respectively. The minimal, mean, and maximal ADCs were all significantly associated with cellularity, with correlation coefficients of -0.712 (p < 0.001), -0.631 (p < 0.001), and -0.460 (p = 0.007), respectively. The minimal and mean ADC had significant negative relationships with the N/C ratio, with correlation coefficients of -0.565 (p =  0.001) and -0.426 (p = 0.013), respectively.

CONCLUSION

The minimal ADC correlated well with cellularity and N/C ratios in C6 glioma and may be used as a biomarker of these two pathological features.

Using deep learning for quantification of cellularity and cell lineages in bone marrow biopsies and comparison to normal age-related variation

Cellularity estimation forms an important aspect of the visual examination of bone marrow biopsies. In clinical practice, cellularity is estimated by eye under a microscope, which is rapid, but subjective and subject to inter- and intraobserver variability. In addition, there is little consensus in the literature on the normal variation of cellularity with age. Digital image analysis may be used for more objective quantification of cellularity. As such, we developed a deep neural network for the segmentation of six major cell and tissue types in digitized bone marrow trephine biopsies. Using this segmentation, we calculated the overall bone marrow cellularity in a series of biopsies from 130 patients across a wide age range. Using intraclass correlation coefficients (ICC), we measured the agreement between the quantification by the neural network and visual estimation by two pathologists and compared it to baseline human performance. We also examined the age-related changes of cellularity and cell lineages in bone marrow and compared our results to those found in the literature. The network was capable of accurate segmentation (average accuracy and dice score of 0.95 and 0.76, respectively). There was good neural network-pathologist agreement on cellularity measurements (ICC=0.78, 95% CI 0.58-0.85). We found a statistically significant downward trend for cellularity, myelopoiesis and megakaryocytes with age in our cohort. The mean cellularity began at approximately 50% in the third decade of life and then decreased ±2% per decade to 40% in the seventh and eighth decade, but the normal range was very wide (30-70%).

Initial Condition Assessment for Reaction-Diffusion Glioma Growth Models: A Translational MRI-Histology (In)Validation Study

Reaction-diffusion models have been proposed for decades to capture the growth of gliomas. Nevertheless, these models require an initial condition: the tumor cell density distribution over the whole brain at diagnosis time. Several works have proposed to relate this distribution to abnormalities visible on magnetic resonance imaging (MRI). In this work, we verify these hypotheses by stereotactic histological analysis of a non-operated brain with glioblastoma using a 3D-printed slicer. Cell density maps are computed from histological slides using a deep learning approach. The density maps are then registered to a postmortem MR image and related to an MR-derived geodesic distance map to the tumor core. The relation between the edema outlines visible on T2-FLAIR MRI and the distance to the core is also investigated. Our results suggest that (i) the previously proposed exponential decrease of the tumor cell density with the distance to the core is reasonable but (ii) the edema outlines would not correspond to a cell density iso-contour and (iii) the suggested tumor cell density at these outlines is likely overestimated. These findings highlight the limitations of conventional MRI to derive glioma cell density maps and the need for other initialization methods for reaction-diffusion models to be used in clinical practice.

On the Additional Information Provided by 3T-MRI ADC in Predicting Tumor Cellularity and Microscopic Behavior

BACKGROUND

to evaluate whether Apparent Diffusion Coefficient (ADC) values of invasive breast cancer, provided by 3T Diffusion Weighted-Images (DWI), may represent a non-invasive predictor of pathophysiologic tumor aggressiveness.

METHODS

100 Patients with histologically proven invasive breast cancers who underwent a 3T-MRI examination were included in the study. All MRI examinations included dynamic contrast-enhanced and DWI/ADC sequences. ADC value were calculated for each lesion. Tumor grade was determined according to the Nottingham Grading System, and immuno-histochemical analysis was performed to assess molecular receptors, cellularity rate, on both biopsy and surgical specimens, and proliferation rate (Ki-67 index). Spearman's Rho test was used to correlate ADC values with histological (grading, Ki-67 index and cellularity) and MRI features. ADC values were compared among the different grading (G1, G2, G3), Ki-67 (<20% and >20%) and cellularity groups (<50%, 50-70% and >70%), using Mann-Whitney and Kruskal-Wallis tests. ROC curves were performed to demonstrate the accuracy of the ADC values in predicting the grading, Ki-67 index and cellularity groups.

RESULTS

ADC values correlated significantly with grading, ER receptor status, Ki-67 index and cellularity rates. ADC values were significantly higher for G1 compared with G2 and for G1 compared with G3 and for Ki-67 < 20% than Ki-67 > 20%. The Kruskal-Wallis test showed that ADC values were significantly different among the three grading groups, the three biopsy cellularity groups and the three surgical cellularity groups. The best ROC curves were obtained for the G3 group (AUC of 0.720), for G2 + G3 (AUC of 0.835), for Ki-67 > 20% (AUC of 0.679) and for surgical cellularity rate > 70% (AUC of 0.805).

CONCLUSIONS

3T-DWI ADC is a direct predictor of cellular aggressiveness and proliferation in invasive breast carcinoma, and can be used as a supporting non-invasive factor to characterize macroscopic lesion behavior especially before surgery.

High parathyroid hormone levels after parathyroidectomy for parathyroid adenoma are not related to the cellularity of the remaining glands

BACKGROUND

Patients with primary hyperparathyroidism (PHPT) treated surgically occasionally have normalized calcium, but persistently high parathyroid hormone (PTH). We hypothesized that a possible explanation for this phenomenon is an underlying hyperplasia rather than adenoma.

METHODS

Retrospective cohort of patients who underwent parathyroidectomy for PHPT with biopsy of a normal-appearing parathyroid gland were included. Cellularity level of each biopsy and of the adenoma's rim was determined.

RESULTS

Forty-seven patients were included. Of them, 19 (40%) had postoperative normocalcemia but elevated PTH. There was no correlation between cellularity either in the rim or of the normal-appearing parathyroid gland and postoperative PTH. The postoperative high PTH group had higher preoperative PTH (P = 0.001) and larger adenomas (P = 0.025).

CONCLUSIONS

High PTH levels after successful parathyroidectomy in patients with primary hyperparathyroidism do not appear to result from underlying hyperplasia. A possible alternative explanation is that these patients have a higher preoperative burden of disease.

Imaging Hallmarks of the Tumor Microenvironment in Glioblastoma Progression

Glioblastoma progression involves multifaceted changes in vascularity, cellularity, and metabolism. Capturing such complexities of the tumor niche, from the tumor core to the periphery, by magnetic resonance imaging (MRI) and spectroscopic imaging (MRSI) methods has translational impact. In human-derived glioblastoma models (U87, U251) we made simultaneous and longitudinal measurements of tumor perfusion (F_p), permeability (K^trans), and volume fractions of extracellular (v_e) and blood (v_p) spaces from dynamic contrast enhanced (DCE) MRI, cellularity from apparent diffusion coefficient (ADC) MRI, and extracellular pH (pH_e) from an MRSI method called Biosensor Imaging of Redundant Deviation in Shifts (BIRDS). Spatiotemporal patterns of these parameters during tumorigenesis were unique for each tumor. While U87 tumors grew faster, F_p, K^trans, and v_p increased with tumor growth in both tumors but these trends were more pronounced for U251 tumors. Perfused regions between tumor periphery and core with U87 tumors exhibited higher F_p, but K^trans of U251 tumors remained lowest at the tumor margin, suggesting primitive vascularization. Tumor growth was uncorrelated with v_e, ADC, and pH_e. U87 tumors showed correlated regions of reduced v_e and lower ADC (higher cellularity), suggesting ongoing proliferation. U251 tumors revealed that the tumor core had higher v_e and elevated ADC (lower cellularity), suggesting necrosis development. The entire tumor was uniformly acidic (pH_e 6.1-6.8) early and throughout progression, but U251 tumors were more acidic, suggesting lower aerobic glycolysis in U87 tumors. Characterizing these cancer hallmarks with DCE-MRI, ADC-MRI, and BIRDS-MRSI will be useful for exploring tumorigenesis as well as timely therapies targeted to specific vascular and metabolic aspects of the tumor microenvironment.

Comparison of the multigene panel test and OncoScan™ for the determination of HER2 amplification in breast cancer

The diagnostic accuracy of the multigene panel test (MPT) and OncoScan™ in the determination of HER2 amplification in breast tumors remains controversial. In the present study, HER2 copy number was analyzed using both MPT and OncoScan™ in 45 breast tumors and was compared with that in fluorescent in situ hybridization (FISH) analysis. Tumors with low cellularity were examined using tumor cell enrichment and fluorescence‑activated cell sorting. Both MPT and OncoScan™ exhibited significant correlations with FISH with respect to the determination of HER2 amplification in breast tumors. However, the correlation coefficient was significantly higher for the comparison of MPT and FISH (r=0.770) compared with that between OncoScan™ and FISH (r=0.564). The accuracy of MPT (93.3%) was slightly higher compared with that in OncoScan™ (84.4%) in determining the HER2 status, which was mostly explained by the higher sensitivity of MPT in tumors with low cellularity (83.3 vs. 33.3%), but not in those with high cellularity (81.8 vs. 72.7%). The specificity was 100% for both tests. The MPT exhibited higher sensitivity in the determination of the amplification of other genes, including MYC, fibroblast growth factor receptor 1 and GATA binding protein 3 in tumors with low cellularity compared with that in tumors with high cellularity. OncoScan™ exhibited low sensitivity without tumor cell enrichment. The results suggested that MPT could be a promising method to determine HER2 status in breast tumors and that it could exhibit improved accuracy compared with that in OncoScan™ in tumors with low cellularity.

Bone marrow adiposity and the hematopoietic niche: A historical perspective of reciprocity, heterogeneity, and lineage commitment

PURPOSE

Here we review the current knowledge on bone marrow adipocytes (BMAds) as active contributors to the regulation of the hematopoietic niche, and as potentially pivotal players in the progression of hematological malignancies. We highlight the hierarchical and functional heterogeneity of the adipocyte lineage within the bone marrow, and how potentially different contexts dictate their interactions with hematopoietic populations.

RECENT FINDINGS

Growing evidence associates the adipocyte lineage with important functions in hematopoietic regulation within the BM niche. Initially proposed to serve as negative regulators of the hematopoietic microenvironment, studies have also demonstrated that BMAds positively influence the survival and maintenance of hematopoietic stem cells (HSCs). These seemingly incongruous findings may at least be partially explained by stage-specificity across the adipocytic differentiation axis and by BMAds subtypes, suggesting that the heterogeneity of these populations allows for differential context-based interactions. One such distinction relies on the location of adipocytes. Constitutive bone marrow adipose tissue (cBMAT) historically associates to the "yellow" marrow containing so-called "stable" BMAs larger in size, less responsive to stimuli, and linked to HSC quiescence. On the other hand, regulated bone marrow adipose tissue (rBMAT)-associated adipocytes, also referred to as "labile" are smaller, more responsive to hematopoietic demand and strategically situated in hematopoietically active regions of the skeleton. Here we propose a model where the effect of distinct BM stromal cell populations (BMSC) in hematopoiesis is structured along the BMSC-BMAd differentiation axis, and where the effects on HSC maintenance versus hematopoietic proliferation are segregated. In doing so, it is possible to explain how recently identified, adipocyte-primed leptin receptor-expressing, CXCL12-high adventitial reticular cells (AdipoCARs) and marrow adipose lineage precursor cells (MALPs) best support active hematopoietic cell proliferation, while adipose progenitor cells (APCs) and maturing BMAd gradually lose the capacity to support active hematopoiesis, favoring HSC quiescence. Implicated soluble mediators include MCP-1, PAI-1, NRP1, possibly DPP4 and limiting availability of CXCL12 and SCF. How remodeling occurs within the BMSC-BMAd differentiation axis is yet to be elucidated and will likely unravel a three-way regulation of the hematopoietic, bone, and adipocytic compartments orchestrated by vascular elements. The interaction of malignant hematopoietic cells with BMAds is precisely contributing to unravel specific mechanisms of remodeling.

SUMMARY

BMAds are important operative components of the hematopoietic microenvironment. Their heterogeneity directs their ability to exert a range of regulatory capacities in a manner dependent on their hierarchical, spatial, and biological context. This complexity highlights the importance of (i) developing experimental tools and nomenclature adapted to address stage-specificity and heterogeneity across the BMSC-BMAd differentiation axis when reporting effects in hematopoiesis, (ii) interpreting gene reporter studies within this framework, and (iii) quantifying changes in all three compartments (hematopoiesis, adiposity and bone) when addressing interdependency.

Deep Neural Network Analysis of Pathology Images With Integrated Molecular Data for Enhanced Glioma Classification and Grading

Gliomas are primary brain tumors that originate from glial cells. Classification and grading of these tumors is critical to prognosis and treatment planning. The current criteria for glioma classification in central nervous system (CNS) was introduced by World Health Organization (WHO) in 2016. This criteria for glioma classification requires the integration of histology with genomics. In 2017, the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) was established to provide up-to-date recommendations for CNS tumor classification, which in turn the WHO is expected to adopt in its upcoming edition. In this work, we propose a novel glioma analytical method that, for the first time in the literature, integrates a cellularity feature derived from the digital analysis of brain histopathology images integrated with molecular features following the latest WHO criteria. We first propose a novel over-segmentation strategy for region-of-interest (ROI) selection in large histopathology whole slide images (WSIs). A Deep Neural Network (DNN)-based classification method then fuses molecular features with cellularity features to improve tumor classification performance. We evaluate the proposed method with 549 patient cases from The Cancer Genome Atlas (TCGA) dataset for evaluation. The cross validated classification accuracies are 93.81% for lower-grade glioma (LGG) and high-grade glioma (HGG) using a regular DNN, and 73.95% for LGG II and LGG III using a residual neural network (ResNet) DNN, respectively. Our experiments suggest that the type of deep learning has a significant impact on tumor subtype discrimination between LGG II vs. LGG III. These results outperform state-of-the-art methods in classifying LGG II vs. LGG III and offer competitive performance in distinguishing LGG vs. HGG in the literature. In addition, we also investigate molecular subtype classification using pathology images and cellularity information. Finally, for the first time in literature this work shows promise for cellularity quantification to predict brain tumor grading for LGGs with IDH mutations.

Stability of sputum inflammatory phenotypes in childhood asthma during stable and exacerbation phases

BACKGROUND

Management strategies based on airway inflammation phenotypes are increasingly used for adults with asthma. While sputum-based phenotypes are relatively stable in adults with asthma, there is little such data in childhood asthma. Hence, we aimed to evaluate the stability of sputum inflammatory phenotypes in children with asthma both in the stable and during exacerbation phases.

METHODS

Sputum cellularity data from two previous prospective studies involving children with asthma were re-evaluated and categorized into two inflammatory phenotypes: eosinophilic (>2.5% eosinophils) and noneosinophilic (≤2.5% eosinophils). Baseline values and follow-up sputum inflammatory phenotype classification were compared in children with asthma during stable and exacerbation phases.

RESULTS

Thirteen of 32 children (41%) with stable asthma demonstrated a change in sputum inflammatory phenotype 8 weeks later. In a different second cohort, both sputum eosinophils and neutrophils percentages increased and peaked on Day 1 of asthma exacerbation, but compared with baseline, 22% (2/9) and 13% (1/8) of these children had their sputum phenotype categorization changed on Day 1 and Day 3 of exacerbation, respectively.

CONCLUSION

In children with asthma, sputum inflammatory phenotypes are variable in both stable and exacerbation phases, in contrast to data in adults.

Difference in developmental dynamics between subcutaneous and abdominal adipose tissues in goose (Anser Cygnoides)

Goose (Anas cygnoides), as a typical species domesticated from a migratory bird, has maintained the capability of depositing excess lipid and preferentially accumulating fat within the abdomen and subcutaneous, which not only leads to decrease in yield of meat product, but also affects the feed conversion rate. Here, an experiment was conducted to examine the difference in developmental dynamics between subcutaneous (SAT) and abdominal adipose tissues (AAT) in goose. The results showed that SAT could be clearly observed at embryonic days (E) 15, whereas AAT were clearer until E20. Although the weights of SAT and AAT showed a significant rising with advancing age (P < 0.05), their gains were not completely uniform, and more adipose deposited preferentially toward AAT after birth (P < 0.05). Additionally, a clear expansion in adipocyte size was observed in AAT and SAT during embryonic stages (P < 0.05). The average adipocyte area in AAT continued to increase after birth (P < 0.05), while the cell areas in SAT were relatively invariable (P > 0.05). Furthermore, the expression levels of FABP4/aP2, ACSL1 and PPARγ were much higher in SAT than in AAT, whereas relative higher expression level of IL-6 was observed in the AAT during embryonic stages. After birth, the more expression of LPL and PPARα were detected in AAT than did in SAT (P < 0.05), whereas greater ATGL expression was in SAT (P < 0.05). Taken together, these findings suggest that AAT may display greater fat storage capacity than SAT accompanied by changes in cell area and lipogenic capacity. Considering that there is disparity in the individual adipose tissues, we suggested that careful consideration for the precise interventions used to control SAT or AAT deposition in meat-producing animals to improve feed efficiency.

Correlation between cytologic features and histologic grades in cutaneous and subcutaneous soft tissue sarcomas in dogs-A pilot study

Currently, canine soft tissue sarcoma (STS) grading is based on histopathology. In humans, several studies have demonstrated concordance between cytologic grading systems for STS and histologic grade. The aim of this study was to correlate several cytologic parameters (smear cellularity, anisokaryosis, nucleolar malignancy score, multinucleation, and the number of mitotic figures per 200 cells) that form part of a human STS cytologic grading system, with histologic grades of canine cutaneous and subcutaneous STS. Three observers (blinded) reviewed the cytologic preparations independently from cases with confirmed histologic diagnoses of STS. A cytologic grading score was assigned for each parameter. Correlations between cytologic grading scores (averaged between observers) and histologic grades were assessed using Spearman's correlation coefficient, with statistical significance defined as P < .05. Twenty-one cases were included in the study (10 Grade I STS, nine Grade II STS, and two Grade III STS). The number of mitotic figures (≥3) per 200 cells was the only parameter that showed a significant but weak, positive correlation with histologic grade (r_s  = .469; P = .032). No Grade I tumors had ≥3 mitotic figures per 200 cells; however, ≥3 mitotic figures per 200 cells were only observed in 33% of Grade II tumors and 50% (one out of two) of the Grade III tumors. This pilot study suggests that an increased number of mitotic figures seen on cytology might correlate with higher grade STS; however, the sensitivity of this parameter for grading STS appears to be low.

Screening For Bone Marrow Cellularity Changes in Cynomolgus Macaques in Toxicology Safety Studies Using Artificial Intelligence Models

Many compounds affect the cellularity of hematolymphoid organs including bone marrow. Toxicologic pathologists are tasked with their evaluation as part of safety studies. An artificial intelligence (AI) tool could provide diagnostic support for the pathologist. We looked at the ability of a deep-learning AI model to evaluate whole slide images of macaque sternebrae to identify and enumerate bone marrow hematopoietic cells. The AI model was trained and able to differentiate the hematopoietic cells from the other sternebrae tissues. We compared the model to severity scores in a study with decreased hematopoietic cellularity. The mean cells/mm² from the model was lower for each increase in severity score. The AI model was trained by 1 pathologist, providing proof of concept that AI model generation can be fast and agile, without the need of a cross disciplinary team and significant effort. We see great potential for the role of AI-based bone marrow screening.

Preanalytic variables in quality and quantity of nucleic acids extracted from FNA specimens of thyroid gland nodules collected in CytoLyt: Cellularity and storage time

BACKGROUND

Morphologic and genetic analysis of thyroid nodules may be performed from a single vial. Preanalytic variables that affect nucleic acid extracted from a single vial are evaluated.

METHODS

Thyroid fine-needle aspiration (FNA) specimens collected in CytoLyt were evaluated. A ThinPrep slide was prepared. Extracted nucleic acids were analyzed using Oncomine Comprehensive Panel, version 2, after Ion AmpliSeq library preparation. A pathologist and a cytotechnologist enumerated specimen cellularity.

RESULTS

Fifty-six samples were collected from 55 nodules in 53 patients. Bethesda category correlated with cellularity (P = .01), and storage time (median, 43 days; range, 7-77 days) was longer for specimens in categories II and III than for those in categories IV and VI (P = .01). The mean specimen DNA concentration was 4.5 ng/µL (range, 0-23.8 ng/µL), and 25 (45%) had concentrations >3.3 ng/µL. The mean specimen RNA concentration was 4.8 ng/µL (range, 0-42.4 ng/µL), and 31 (55%) had concentrations >1.4 ng/µL. Nucleic acid quantity increased with epithelial cellularity. Storage time weakly correlated with the quantity of extracted DNA, independent of cellularity, but not extracted RNA. Greater proportions of cell-free DNA and lesser proportions of long, intact RNA fragments were extracted from a subset of samples with longer storage time. Among 15 single nucleotide variants, the median mutant allelic fraction was 15.1%. One false-negative result was identified. Five specimens subsequently determined to harbor a genetic alteration failed quality metrics.

CONCLUSIONS

Cellularity and storage time affect the quantity and quality of nucleic acid extracted from thyroid FNA specimens collected in CytoLyt. Further investigation will serve to quantify the magnitude of such effects and to elucidate other contributing factors.

Tumor Cell Representation by an Improvised Technique of Fine-Needle Aspiration Specimen Acquisition and Cell Block Preparation: Our Experience in Lung Cancer Cases in a Peripheral Center of Eastern India

Background

Being a minimally invasive diagnostic technique, Fine-Needle Aspiration Cytology (FNAC) has become the first-line test and corresponding aspirated material has become the target specimen for diagnosis and ancillary tests in lung carcinoma. Although the role of Cell Blocks (CBs) in diagnosis and in ancillary testing is well recognized in literature, limited attention has been paid to specimen procurement and triage in the preparation of CBs. In the present scenario, CBs are not consistently optimal because of its low cellularity.

Aims

This study is aimed to describe an improvised technique of specimen acquisition and cell block preparation in CT-guided FNACs of lung carcinoma cases in a resource-constrained center and to assess its efficacy for optimal representation of cellularity, morphology, and architecture.

Materials and Methods

Total 85 lung carcinoma cases undergoing CT-guided FNAC in our center from February 2017 to January 2018 were included in this study. 4 to 5 direct smears and subsequent CBs were made from material obtained by single pass. Cellularity of smears and corresponding cell blocks were assessed and categorized according to a scoring system (score 1 to 3 for number of cells <50, 50-100, >100, respectively). Preserved architecture and morphology were also assessed in smears and CBs.

Results

The evaluated samples showed a cellularity score 3 in 65.4%CBs and score 2 in 24.7% CBs. Overall, 90.1% cell blocks had acceptable cellularity. Cell morphology was preserved in all CBs of acceptable cellularity, except for two adenocarcinoma, one squamous cell carcinoma, and one small cell carcinoma blocks. Cellular architecture was also preserved in all CBs of acceptable cellularity.

Conclusions

This simple improvised technique of CB preparation optimized its cellularity, morphology, and architectural preservation, even after adequate cellular FNA smears.

Lipid Deposition and Metabolism in Local and Modern Pig Breeds: A Review

Modern pig breeds, which have been genetically improved to achieve fast growth and a lean meat deposition, differ from local pig breeds with respect to fat deposition, fat specific metabolic characteristics and various other properties. The present review aimed to elucidate the mechanisms underlying the differences between fatty local and modern lean pig breeds in adipose tissue deposition and lipid metabolism, taking into consideration morphological, cellular, biochemical, transcriptomic and proteomic perspectives. Compared to modern breeds, local pig breeds accumulate larger amounts of fat, which generally contains more monounsaturated and saturated fatty acids; they exhibit a higher adipocyte size and higher activity of lipogenic enzymes. Studies using transcriptomic and proteomic approaches highlighted several processes like immune response, fatty-acid turn-over, oxidoreductase activity, mitochondrial function, etc. which differ between local and modern pig breeds.

Differential impacts of late gestational over-and undernutrition on adipose tissue traits and associated visceral obesity risk upon exposure to a postnatal high-fat diet in adolescent sheep

We hypothesized that late gestation malnutrition differentially affects expandability of adipose tissues to predispose for early postnatal visceral adiposity. Twin-lambs born to dams fed HIGH (150%/110% of required energy/protein, respectively), NORM (100% of requirements) or LOW (50% of NORM) diets during the last trimester were used. Postnatally, lambs were raised on moderate (CONV) or high-carbohydrate-high-fat (HCHF) diets. Adipose tissues were sampled at autopsy at 6 months of age (~puberty) to characterize cellularity, adipocyte cross-sectional area and gene expression patterns. HIGH and LOW compared to NORM lambs had reduced intrinsic (under CONV diet) cellularity in subcutaneous and mesenteric (particularly LOW), and reduced obesity-induced (under HCHF diet) hyperplasia in subcutaneous, mesenteric and perirenal (particularly HIGH) adipose tissues. This corresponded with more pronounced HCHF diet-induced hypertrophy in mesenteric (particularly LOW), perirenal (particularly HIGH) and subcutaneous (particularly HIGH) adipose tissues, and tissue-specific reductions in mRNA expressions for lipid metabolism, angiogenesis and adipose development. Gene expression for inflammation and lipid metabolism markers were increased and decreased, respectively, in HCHF lambs (HCHF lambs became obese) in all tissues. Both prenatal over- and undernutrition predisposed for abdominal adiposity and extreme perirenal hypertrophy due to reduced intrinsic (observed under CONV diet) cellularity and impaired ability of subcutaneous, mesenteric and perirenal adipose tissues to expand by hyperplasia rather than hypertrophy on an obesogenic (HCHF) diet.

MarrowQuant Across Aging and Aplasia: A Digital Pathology Workflow for Quantification of Bone Marrow Compartments in Histological Sections

The bone marrow (BM) exists heterogeneously as hematopoietic/red or adipocytic/yellow marrow depending on skeletal location, age, and physiological condition. Mouse models and patients undergoing radio/chemotherapy or suffering acute BM failure endure rapid adipocytic conversion of the marrow microenvironment, the so-called "red-to-yellow" transition. Following hematopoietic recovery, such as upon BM transplantation, a "yellow-to-red" transition occurs and functional hematopoiesis is restored. Gold Standards to estimate BM cellular composition are pathologists' assessment of hematopoietic cellularity in hematoxylin and eosin (H&E) stained histological sections as well as volumetric measurements of marrow adiposity with contrast-enhanced micro-computerized tomography (CE-μCT) upon osmium-tetroxide lipid staining. Due to user-dependent variables, reproducibility in longitudinal studies is a challenge for both methods. Here we report the development of a semi-automated image analysis plug-in, MarrowQuant, which employs the open-source software QuPath, to systematically quantify multiple bone components in H&E sections in an unbiased manner. MarrowQuant discerns and quantifies the areas occupied by bone, adipocyte ghosts, hematopoietic cells, and the interstitial/microvascular compartment. A separate feature, AdipoQuant, fragments adipocyte ghosts in H&E-stained sections of extramedullary adipose tissue to render adipocyte area and size distribution. Quantification of BM hematopoietic cellularity with MarrowQuant lies within the range of scoring by four independent pathologists, while quantification of the total adipocyte area in whole bone sections compares with volumetric measurements. Employing our tool, we were able to develop a standardized map of BM hematopoietic cellularity and adiposity in mid-sections of murine C57BL/6 bones in homeostatic conditions, including quantification of the highly predictable red-to-yellow transitions in the proximal section of the caudal tail and in the proximal-to-distal tibia. Additionally, we present a comparative skeletal map induced by lethal irradiation, with longitudinal quantification of the "red-to-yellow-to-red" transition over 2 months in C57BL/6 femurs and tibiae. We find that, following BM transplantation, BM adiposity inversely correlates with kinetics of hematopoietic recovery and that a proximal to distal gradient is conserved. Analysis of in vivo recovery through magnetic resonance imaging (MRI) reveals comparable kinetics. On human trephine biopsies MarrowQuant successfully recognizes the BM compartments, opening avenues for its application in experimental, or clinical contexts that require standardized human BM evaluation.

Evaluation of cellular adequacy in endometrial liquid-based cytology

OBJECTIVE

This study evaluated cellular adequacy in endometrial liquid-based cytology (LBC) specimens.

METHODS

In total, 1267 cases were obtained and the rate of unsatisfactory specimen and diagnostic accuracy for malignancy were assessed. If ≥10 cellular clusters composed of ≤30 endometrial cells were found per specimen, then the sample was provisionally considered adequate.

RESULTS

The unsatisfactory rate (with fewer than 10 clusters) was 15.4%. Diagnostic accuracy in specimens with ≥10 clusters was significantly higher (90.5% vs 36.4%) than that in specimens with fewer than10 clusters. Moreover, the unsatisfactory rate in patients aged ≥60 years was significantly higher (33.8% vs 13.2%) than that in patients younger than 60 years. Although the unsatisfactory rate was decreased, significant differences were not found between cases with fewer than five clusters (22.6%) and fewer than 10 clusters (33.8%) in patients aged ≥60 years. Diagnostic accuracy in cases with five or more clusters was significantly higher (90.3% vs 0%) than that in cases with fewer than five clusters.

CONCLUSIONS

We propose that ≥10 clusters with ≥30 endometrial cells per cluster could be used as a specimen adequacy criterion for endometrial LBC. If ≥10 clusters cannot be found in patients aged ≥60 years, then the use of the alternative criterion of five or more clusters may yield satisfactory specimen adequacy.

Reduced Number of Adipose Lineage and Endothelial Cells in Epididymal fat in Response to Omega-3 PUFA in Mice Fed High-Fat Diet

We found previously that white adipose tissue (WAT) hyperplasia in obese mice was limited by dietary omega-3 polyunsaturated fatty acids (omega-3 PUFA). Here we aimed to characterize the underlying mechanism. C57BL/6N mice were fed a high-fat diet supplemented or not with omega-3 PUFA for one week or eight weeks; mice fed a standard chow diet were also used. In epididymal WAT (eWAT), DNA content was quantified, immunohistochemical analysis was used to reveal the size of adipocytes and macrophage content, and lipidomic analysis and a gene expression screen were performed to assess inflammatory status. The stromal-vascular fraction of eWAT, which contained most of the eWAT cells, except for adipocytes, was characterized using flow cytometry. Omega-3 PUFA supplementation limited the high-fat diet-induced increase in eWAT weight, cell number (DNA content), inflammation, and adipocyte growth. eWAT hyperplasia was compromised due to the limited increase in the number of preadipocytes and a decrease in the number of endothelial cells. The number of leukocytes and macrophages was unaffected, but a shift in macrophage polarization towards a less inflammatory phenotype was observed. Our results document that the counteraction of eWAT hyperplasia by omega-3 PUFA in dietary-obese mice reflects an effect on the number of adipose lineage and endothelial cells.

The Absolute Number of Oligodendrocytes in the Adult Mouse Brain

The central nervous system is a highly complex network composed of various cell types, each one with different subpopulations. Each cell type has distinct roles for the functional operation of circuits, and ultimately, for brain physiology in general. Since the absolute number of each cell type is considered a proxy of its functional complexity, one approach to better understand how the brain works is to unravel its absolute cellularity and the quantitative relations between cell populations; in other words, how one population of cells is quantitatively structured, in relation to another. Oligodendrocytes are one of these cell types - mainly, they provide electric insulation to axons, optimizing action potential conduction. Their function has recently been revisited and their role extended, one example being their capability of providing trophic support to long axons. To determine the absolute cellularity of oligodendroglia, we have developed a protocol of oligodendrocyte quantification using the isotropic fractionator with a pan-marker for this cell type. We report a detailed assessment of specificity and universality of the oligodendrocyte transcription factor 2 (Olig2), through systematic confocal analyses of the C57BL/6 mouse brain. In addition, we have determined the absolute number (17.4 million) and proportion (about 20%) of this cell type in the brain (and in different brain regions), and tested if this population, at the intraspecific level, scales with the number of neurons in an allometric-based approach. Considering these numbers, oligodendrocytes proved to be the most numerous of glial cells in the mouse brain.

Cell Count Analysis from Nonbronchoscopic Bronchoalveolar Lavage in Preterm Infants

OBJECTIVES

To establish the reference values, diagnostic accuracy, and effect of various factors on cell count in intubated preterm neonates subjected to nonbronchoscopic bronchoalveolar lavage.

STUDY DESIGN

This prospective, cross-sectional, blinded study included preterm neonates ventilated for any reason who underwent nonbronchoscopic bronchoalveolar lavage if they had not previously received postnatal antibiotics or steroids. Lavage was performed before surfactant replacement, if any. A gentle ventilation policy was applied. Pneumonia was diagnosed using clinical criteria, without considering cell count. Investigators performing cell counts were blinded to the clinical data.

RESULTS

There were 276 neonates enrolled; 36 had congenital or ventilator-associated pneumonia. In the 240 noninfected babies, median neutrophil count increased significantly after the first 2 days of ventilation (day 1, 2 cells per field [IQR, 0.0-9.5 cells per field]; day 2, 2 cells per field [IQR, 0-15 cells per field]; day 3, 20 cells per field [IQR, 2-99 cells per field]; day 4, 15 cells per field [IQR, 2-96 cells per field]; P < .0001). No significant difference was seen over time in infected babies. Multivariate analysis indicated pneumonia (standardized β = 0.134; P = .033) and the time spent under mechanical ventilation before nonbronchoscopic bronchoalveolar lavage as factors significantly influencing neutrophil count (standardized β = 0.143; P = .027). Neutrophil count was correlated with the duration of ventilation (rho = 0.28; P <.001). Neutrophil counts were higher in infected (24 cells/field [IQR, 5-78] cells/field) than in noninfected babies (4 cells/field [IQR, 1-24 cells/field]; P <.001) and had an moderate reliability for pneumonia within the first 2 days of ventilation (area under the curve, 0.745; (95% CI, 0.672-0.810; P = .002).

CONCLUSIONS

We provide reference values for airway neutrophil counts in ventilated preterm neonates. Bronchoalveolar lavage neutrophils significantly increase after 2 days of ventilation. Neutrophil count has moderate accuracy to diagnose pneumonia, but only within the first 2 days of ventilation.

Abnormal development of the inferior temporal region in fetuses with Down syndrome

Down syndrome (DS) is a genetic condition associated with impairment in several cognitive domains. Previous evidence showed a notable neurogenesis reduction in the hippocampal region of DS fetuses, which may account for the impairment of declarative memory that characterizes DS starting from early life stages. The fusiform gyrus (FG) and the inferior temporal gyrus (ITG) play a key role in visual recognition memory, a function that is impaired in children and adults with DS. The goal of the current study was to establish whether fetuses with DS (17-21 weeks of gestation) exhibit neuroanatomical alterations in the FG and ITG that may underlie recognition memory impairment. We found that the FG and ITG of fetuses with DS had a reduced thickness and fewer cells in comparison with euploid fetuses. Moreover, DS fetuses had fewer cells expressing the neuronal marker NeuN than euploid fetuses, but a similar number of cells expressing the astrocytic marker GFAP and, consequently, a higher percentage of astrocytes. Immunohistochemistry for calretinin (CR), a marker of GABAergic interneurons, showed that in DS fetuses the ratio of CR-positive vs. CR-negative cells was greater than in euploid fetuses, both in the FG (177%) and ITG (161%). An increased ratio of CR-positive vs. CR-negative cells was also found in the entorhinal cortex, hippocampus and dentate gyrus. Results provide novel evidence that the FG and ITG of DS fetuses exhibit numerous developmental defects. These defects may underlie the functional alterations in visual recognition memory observed in children with DS.

Quantitative susceptibility mapping (QSM) minimizes interference from cellular pathology in R2* estimation of liver iron concentration

BACKGROUND

A challenge for R2 and R2* methods in measuring liver iron concentration (LIC) is that fibrosis, fat, and other hepatic cellular pathology contribute to R2 and R2* and interfere with LIC estimation.

PURPOSE

To examine the interfering effects of fibrosis, fat, and other lesions on R2* LIC estimation and to use quantitative susceptibility mapping (QSM) to reduce these distortions.

STUDY TYPE

Prospective.

PHANTOMS, SUBJECTS

Water phantoms with various concentrations of gadolinium (Gd), collagen (Cl, modeling fibrosis), and fat; nine healthy controls with no known hepatic disease, nine patients with known or suspected hepatic iron overload, and nine patients with focal liver lesions.

FIELD STRENGTH/SEQUENCE

The phantoms and human subjects were imaged using a 3D multiecho gradient-echo on clinical 1.5T and 3T MRI systems.

ASSESSMENT

QSM and R2* images were postprocessed from the same gradient-echo data. Fat contributions to susceptibility and R2* were corrected in signal models for LIC estimation.

STATISTICAL TESTS

Polynomial regression analyses were performed to examine relations among susceptibility, R2* and true [Gd] and [Cl] in phantoms, and among susceptibility and R2* in patient livers.

RESULTS

In phantoms, R2* had a strong nonlinear dependency on [Cl], [fat], and [Gd], while susceptibility was linearly dependent (R²  > 0.98). In patients, R2* was highly sensitive to liver pathological changes, including fat, fibrosis, and tumors, while QSM was relatively insensitive to these abnormalities (P = 0.015). With moderate iron overload, liver susceptibility and R2* were not linearly correlated over a common R2* range [0, 100] sec^-1 (P = 0.35).

DATA CONCLUSION

R2* estimation of LIC is prone to substantial nonlinear interference from fat, fibrosis, and other lesions. QSM processing of the same gradient echo MRI data can effectively minimize the effects of cellular pathology.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;48:1069-1079.

AdipoCount: A New Software for Automatic Adipocyte Counting

Obesity has spread worldwide and become a common health problem in modern society. One typical feature of obesity is the excessive accumulation of fat in adipocytes, which occurs through the following two physiological phenomena: hyperplasia (increase in quantity) and hypertrophy (increase in size) of adipocytes. In clinical and scientific research, the accurate quantification of the number and diameter of adipocytes is necessary for assessing obesity. In this study, we present a new automatic adipocyte counting system, AdipoCount, which is based on image processing algorithms. Comparing with other existing adipocyte counting tools, AdipoCount is more accurate and supports further manual correction. AdipoCount counts adipose cells by the following three-step process: (1) It detects the image edges, which are used to segment the membrane of adipose cells; (2) It uses a watershed-based algorithm to re-segment the missing dyed membrane; and (3) It applies a domain connectivity analysis to count the cells. The outputs of this system are the labels and the statistical data of all adipose cells in the image. The AdipoCount software is freely available for academic use at: http://www.csbio.sjtu.edu.cn/bioinf/AdipoCount/.

Digital image analysis agrees with visual estimates of adult bone marrow trephine biopsy cellularity

INTRODUCTION

Evaluation of cellularity is an essential component of bone marrow trephine biopsy examination. The standard practice is to report the results as visual estimates (VE). Digital image analysis (DIA) offers the promise of more objective measurements of cellularity.

METHODS

Adult bone marrow trephine biopsy sections were assessed for cellularity by VE. Sections were scanned using an Aperio AT2 Scanscope and analyzed using a Cytonuclear (version 1.4) algorithm on halo software. Intraclass correlation (ICC) was used to assess relatedness between VE and DIA, and between MRI and DIA for a separate subset of patients. Trephine biopsy sections from a subset of patients with bone marrow biopsies uninvolved by malignancy were assessed for age-related changes.

RESULTS

Interobserver VE agreement was good to excellent. The ICC value was 0.81 for VE and DIA, and 0.50 for MRI and DIA. Linearity studies showed no statistically significant trend for age-related changes in cellularity in our cohort (r = -.29, P = .06).

CONCLUSIONS

Agreement was good between VE and DIA. It may be possible to use DIA or VE to measure cellularity in the appropriate clinical scenario. The limited sample size precludes similar determinations for MRI calculations. Further studies examining healthy donors are necessary before making definitive conclusions regarding age and cellularity.

Non-Invasive Prostate Cancer Characterization with Diffusion-Weighted MRI: Insight from In silico Studies of a Transgenic Mouse Model

Diffusion-weighted magnetic resonance imaging (DWI) enables non-invasive, quantitative staging of prostate cancer via measurement of the apparent diffusion coefficient (ADC) of water within tissues. In cancer, more advanced disease is often characterized by higher cellular density (cellularity), which is generally accepted to correspond to a lower measured ADC. A quantitative relationship between tissue structure and in vivo measurements of ADC has yet to be determined for prostate cancer. In this study, we establish a theoretical framework for relating ADC measurements with tissue cellularity and the proportion of space occupied by prostate lumina, both of which are estimated through automatic image processing of whole-slide digital histology samples taken from a cohort of six healthy mice and nine transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. We demonstrate that a significant inverse relationship exists between ADC and tissue cellularity that is well characterized by our model, and that a decrease of the luminal space within the prostate is associated with a decrease in ADC and more aggressive tumor subtype. The parameters estimated from our model in this mouse cohort predict the diffusion coefficient of water within the prostate-tissue to be 2.18 × 10-3 mm2/s (95% CI: 1.90, 2.55). This value is significantly lower than the diffusion coefficient of free water at body temperature suggesting that the presence of organelles and macromolecules within tissues can drastically hinder the random motion of water molecules within prostate tissue. We validate the assumptions made by our model using novel in silico analysis of whole-slide histology to provide the simulated ADC (sADC); this is demonstrated to have a significant positive correlation with in vivo measured ADC (r2 = 0.55) in our mouse population. The estimation of the structural properties of prostate tissue is vital for predicting and staging cancer aggressiveness, but prostate tissue biopsies are painful, invasive, and are prone to complications such as sepsis. The developments made in this study provide the possibility of estimating the structural properties of prostate tissue via non-invasive virtual biopsies from MRI, minimizing the need for multiple tissue biopsies and allowing sequential measurements to be made for prostate cancer monitoring.

Modifications of pancreatic diffusion MRI by tissue characteristics: what are we weighting for?

Diffusion-weighted imaging holds the potential to improve the diagnosis and biological characterization of pancreatic disease, and in particular pancreatic cancer, which exhibits decreased values of the apparent diffusion coefficient (ADC). Yet, variable and overlapping ADC values have been reported for the healthy and the pathological pancreas, including for cancer and other benign conditions. This controversy reflects the complexity of probing the water-diffusion process in the pancreas, which is dependent upon multiple biological factors within this organ's unique physiological environment. In recent years, extensive studies have investigated the correlation between tissue properties including cellularity, vascularity, fibrosis, secretion and microstructure and pancreatic diffusivity. Understanding how the various physiological and pathological features and the underlying functional processes affect the diffusion measurement may serve to optimize the method for improved diagnostic gain. Therefore, the aim of the present review article is to elucidate the relationship between pancreatic tissue characteristics and diffusion MRI measurement.

In vivo imaging of cancer cell size and cellularity using temporal diffusion spectroscopy

PURPOSE

A temporal diffusion MRI spectroscopy based approach has been developed to quantify cancer cell size and density in vivo.

METHODS

A novel imaging microstructural parameters using limited spectrally edited diffusion (IMPULSED) method selects a specific limited diffusion spectral window for an accurate quantification of cell sizes ranging from 10 to 20 μm in common solid tumors. In practice, it is achieved by a combination of a single long diffusion time pulsed gradient spin echo (PGSE) and three low-frequency oscillating gradient spin echo (OGSE) acquisitions. To validate our approach, hematoxylin and eosin staining and immunostaining of cell membranes, in concert with whole slide imaging, were used to visualize nuclei and cell boundaries, and hence, enabled accurate estimates of cell size and cellularity.

RESULTS

Based on a two compartment model (incorporating intra- and extracellular spaces), accurate estimates of cell sizes were obtained in vivo for three types of human colon cancers. The IMPULSED-derived apparent cellularities showed a stronger correlation (r = 0.81; P < 0.0001) with histology-derived cellularities than conventional ADCs (r = -0.69; P < 0.03).

CONCLUSION

The IMPULSED approach samples a specific region of temporal diffusion spectra with enhanced sensitivity to length scales of 10-20 μm, and enables measurements of cell sizes and cellularities in solid tumors in vivo. Magn Reson Med 78:156-164, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Correlation between apparent diffusion coefficient (ADC) and cellularity is different in several tumors: a meta-analysis

The purpose of this meta-analysis was to provide clinical evidence regarding relationship between ADC and cellularity in different tumors based on large patient data.

Medline library was screened for associations between ADC and cell count in different tumors up to September 2016. Only publications in English were extracted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) was used for the research.

Overall, 39 publications with 1530 patients were included into the analysis. The following data were extracted from the literature: authors, year of publication, number of patients, tumor type, and correlation coefficients.

The pooled correlation coefficient for all studies was ρ = -0.56 (95 % CI = [−0.62; −0.50]),. Correlation coefficients ranged from ρ =−0.25 (95 % CI = [−0.63; 0.12]) in lymphoma to ρ=−0.66 (95 % CI = [−0.85; −0.47]) in glioma. Other coefficients were as follows: ovarian cancer, ρ = −0.64 (95% CI = [−0.76; −0.52]); lung cancer, ρ = −0.63 (95 % CI = [−0.78; −0.48]); uterine cervical cancer, ρ = −0.57 (95 % CI = [−0.80; −0.34]); prostatic cancer, ρ = −0.56 (95 % CI = [−0.69; −0.42]); renal cell carcinoma, ρ = −0.53 (95 % CI = [−0.93; −0.13]); head and neck squamous cell carcinoma, ρ = −0.53 (95 % CI = [-0.74; −0.32]); breast cancer, ρ = −0.48 (95 % CI = [−0.74; −0.23]); and meningioma, ρ = -0.45 (95 % CI = [−0.73; −0.17]).

Dietary magnesium intake alters age-related changes in rat adipose tissue cellularity

Obesity and related metabolic diseases are associated with increased risk of cardiovascular disease. We have previously shown the beneficial effects of dietary magnesium (Mg) supplementation on cardiovascular disease in rats. Therefore, we aimed to examine the effect of an Mg-deficient or supplemented diet on adipose tissue cellularity changes during aging, and on blood pressure (BP), in rats. Male rats received for one (young adult) or 22 months (old), an Mg-deficient (Def) (150 mg/kg), standard (Std) (800 mg/kg) or Mg-supplemented (Sup) (3200 mg/kg) diet. Adipose tissue development and cellularity, BP and leptinemia were evaluated. In rats fed a standard diet, the large increase in adipose tissue weight observed during aging was related to an increase in both size and number of adipocytes. In young adult rats, although adiposity was unchanged, Mg supplementation resulted in a shift of the frequency distribution of adipocytes toward greater sizes, adipose cell weight increasing by 62%. Mg deficiency did not modify adipocyte size, but increased their number (30% more than for the standard or Sup-diet). In old rats, the Def-diet led to relative adipocyte hypotrophy, which was counterbalanced by an increase in the number of adipocyte. Conversely, adipocyte size and number were similar in the Sup-diet and standard diet-fed rats. BP was modified in old rats according to dietary Mg, whereas it remained unchanged young adult rats regardless of the diet received. This study suggests that Mg intake may affect age-related changes in rat adipose tissue lipid storage capacity.

Prognostic factors of successful on-purpose tumor biopsies in metastatic cancer patients included in the SHIVA prospective clinical trial

PURPOSE

To identify patient/tumor characteristics associated with success of biopsy in patients who received multiple lines of chemotherapy.

METHODS

Patients with refractory cancer from our center, who were included in a prospective randomized phase II trial comparing targeted therapies based on molecular profile of tumors versus conventional chemotherapy, were retrospectively included in this IRB-approved study. All patients had a biopsy of a tumor lesion performed during surgery, or using CT/palpation/endoscopic guidance. A biopsy was considered successful if the neoplastic cellularity was greater than 30%. Primary lesion, size and location of biopsied lesion, on-going chemotherapy and the differential attenuation between non-enhanced and venous phase (HU) for CT-guided biopsied lesions were recorded.

RESULTS

228 patients (age=59±15yo; M/F=1.9) were included. One hundred and sixty biopsies (72%) of the 221 biopsies performed were successful. Prognostic factors of biopsy success were: no ongoing chemotherapy, surgical or palpation-guided biopsy, lymph nodes/soft tissue location(P <0.01). Among the 221 performed biopsies, 122 (55%) were performed using CT guidance and 82 (67%) were successful. In this subgroup, biopsied lesions located in lymph nodes/soft tissue were associated with a higher success rate while lung location was associated with failure (P <0.01). The mean differential attenuation was significantly higher in lesions with a successful biopsy (P <0.001).

CONCLUSION

Success of biopsy was less frequent with CT guidance than with surgical or palpation-guided biopsy and was higher in soft tissues and lymph nodes than that in visceral metastasis. Ongoing chemotherapy decreased tumor cell content and consequently the success of the biopsy samples for molecular profiling.

A Novel System for Estimating Residual Disease and Pathologic Response to Neoadjuvant Treatment of Prostate Cancer

BACKGROUND

Pathologic variables that characterize response of prostate carcinoma to current neoadjuvant therapy have not been characterized in detail. This study reports (i) the histological features of prostate cancer treated with abiraterone and enzalutamide and inter-pathologist variance in identifying these features, and (ii) the effect of the novel androgen deprivation agents on residual cancer volume.

METHODS

We reviewed sections of prostatectomies from 37 patients treated with neoadjuvant agents and 22 untreated patients, tabulated the frequency of nine features of cancer (intact cancer glands, isolated cancer cells, poorly formed glands, cribriform architecture, clear spaces, intraductal carcinoma, solid sheets of cancer cells, prominent nucleoli, and previously described ABC grouping) and two features of benign glands (prominent basal cells and coalescent corpora amylacea). We used several methods, including a novel metric (visual grid system), to estimate residual tumor volume.

RESULTS

The most highly reproducible features were ABC grouping (κ = 0.56-0.7), presence of intraductal carcinoma (κ = 0.34-0.72), cribriform architecture (κ = 0.42-0.68), solid sheets of tumor cells (κ = 0.44-0.56), and coalescent corpora amylacea (κ = 0.4-0.54). Among poorly reproducible features were prominent nucleoli (κ = 0.03-0.11), clear spaces (κ = 0.05-0.07), and poorly formed cancer glands (κ = 0.02-0.1). Determination of tumor mass was excellent regardless of the method used-maximum tumor size (κ = 0.9-0.94), tumor area (κ = 0.94-0.96), and grid-based tumor cellularity (κ = 0.9).

CONCLUSIONS

We propose using a set of parameters including maximum tumor size, tumor area/volume, cellularity, volume, and ABC grouping for evaluating radical prostatectomies post-neoadjuvant therapy. Prostate 76:1285-1292, 2016. © 2016 Wiley Periodicals, Inc.

Endometrial cancer: correlation of apparent diffusion coefficient (ADC) with tumor cellularity and tumor grade

BACKGROUND

Diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) are widely used for detecting uterine endometrial cancer. The relationships between ADC values and pathological features of endometrial cancer have not yet been established.

PURPOSE

To investigate whether ADC values of endometrial cancer vary according to histologic tumor cellularity and tumor grade.

MATERIAL AND METHODS

We retrospectively reviewed 30 pathologically confirmed endometrial cancers. All patients underwent conventional non-enhanced magnetic resonance imaging (MRI) and DWI procedures, and ADC values were calculated. Tumor cellularity was evaluated by counting cancer cells in three high-power ( × 400) fields. The correlation between ADC values and tumor cellularity was assessed using Pearson's correlation coefficient test for statistical analysis.

RESULTS

The mean ± standard deviation (SD) ADC value ( ×10(-3) mm(2)/s) of endometrial cancer was 0.85 ± 0.22 (range, 0.55-1.71). The mean ± SD tumor cellularity was 528.36 ± 16.89 (range, 298.0-763.6). ADC values were significantly inversely correlated with tumor cellularity. No significant relationship was observed between ADC values and tumor grade (mean ADC values: G1, 0.88 ± 0.265 × 10(-3) mm(2)/s; G2, 0.80 ± 0.178 × 10(-3) mm(2)/s; G3, 0.81 ± 0.117 × 10(-3) mm(2)/s).

CONCLUSION

There is a significant inverse relationship between ADC values and tumor cellularity in endometrial cancer. No significant differences in average ADC value were observed between G1, G2, and G3 tumors. However, the lower the tumor grade, the wider the SD.

Biological, biochemical and biomechanical characterisation of articular cartilage from the porcine, bovine and ovine hip and knee

This study aimed to determine the optimal starting material for the development of an acellular osteochondral graft. Osteochondral tissues from three different species were characterised; pig (6 months), cow (18 months) and two ages of sheep (8-12 months and >4 year old). Tissues from the acetabulum and femoral head of the hip, and the groove, medial and lateral condyles and tibial plateau of the knee were assessed. Histological analysis of each tissue allowed for qualification of cartilage histoarchitecture, glycosaminoglycan (GAG) distribution, assessment of cellularity and cartilage thickness. Collagen and GAG content were quantified and cartilage water content was defined. Following biomechanical testing, the percentage deformation, permeability and equilibrium elastic modulus was determined. Results showed that porcine cartilage had the highest concentration of sulphated proteoglycans and that the condyles and groove of the knee showed higher GAG content than other joint areas. Cartilage from younger tissues (porcine and young ovine) had higher cell content and was thicker, reflecting the effects of age on cartilage structure. Cartilage from older sheep had a much higher elastic modulus and was less permeable than other species.

Differentiation of Diffuse Large B-cell Lymphoma From Follicular Lymphoma Using Texture Analysis on Conventional MR Images at 3.0 Tesla

RATIONAL AND OBJECTIVES

Diffuse large B-cell lymphoma (DLBCL) represents the most common type of aggressive non-Hodgkin lymphoma (NHL); follicular lymphoma (FL) is the most frequent indolent NHL. The aim of this study was to investigate whether texture-based analysis of conventional magnetic resonance imaging (MRI) allows discrimination of DLBCL from FL, and further, to correlate the MRI texture features with diffusion-weighted imaging apparent diffusion coefficient (ADC) value and tumor tissue cellularity.

MATERIALS AND METHODS

Forty-one patients with histologically proven NHL (30 DLBCL and 11 FL) underwent conventional MRI and diffusion-weighted imaging examination before treatment. Based on regions of interest, texture analysis was performed on T1-weighted images pre- and postcontrast enhancement and on T2-weighted images with and without fat suppression, and features derived from the run-length matrix- and co-occurrence matrix-based methods were analyzed. Receiver operating characteristic curves were performed for the three most discriminative texture features for the differentiation of the two most common types of lymphoma. The analyzed MRI texture features were correlated with the ADC value and the tumor tissue cellularity.

RESULTS

We found that on T1-weighted images postcontrast enhancement, run-length matrix-based texture analysis for lesion classification differentiated DLBCL from FL, with specificity and sensitivity of 76.6% and 76.5%, respectively. There was no correlation between the texture features and the ADC value or tumor tissue cellularity.

CONCLUSIONS

DLBCL and FL can be differentiated by means of texture analysis on T1-weighted MRI postcontrast enhancement. These results could serve as a basis for the use of the texture features on conventional MRI as adjunct to clinical examination to distinguish DLBCL from FL.

A prospective Phase II clinical trial of 5-aminolevulinic acid to assess the correlation of intraoperative fluorescence intensity and degree of histologic cellularity during resection of high-grade gliomas

OBJECT There is evidence that 5-aminolevulinic acid (ALA) facilitates greater extent of resection and improves 6-month progression-free survival in patients with high-grade gliomas. But there remains a paucity of studies that have examined whether the intensity of ALA fluorescence correlates with tumor cellularity. Therefore, a Phase II clinical trial was undertaken to examine the correlation of intensity of ALA fluorescence with the degree of tumor cellularity. METHODS A single-center, prospective, single-arm, open-label Phase II clinical trial of ALA fluorescence-guided resection of high-grade gliomas (Grade III and IV) was held over a 43-month period (August 2010 to February 2014). ALA was administered at a dose of 20 mg/kg body weight. Intraoperative biopsies from resection cavities were collected. The biopsies were graded on a 4-point scale (0 to 3) based on ALA fluorescence intensity by the surgeon and independently based on tumor cellularity by a neuropathologist. The primary outcome of interest was the correlation of ALA fluorescence intensity to tumor cellularity. The secondary outcome of interest was ALA adverse events. Sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), and Spearman correlation coefficients were calculated. RESULTS A total of 211 biopsies from 59 patients were included. Mean age was 53.3 years and 59.5% were male. The majority of biopsies were glioblastoma (GBM) (79.7%). Slightly more than half (52.5%) of all tumors were recurrent. ALA intensity of 3 correlated with presence of tumor 97.4% (PPV) of the time. However, absence of ALA fluorescence (intensity 0) correlated with the absence of tumor only 37.7% (NPV) of the time. For all tumor types, GBM, Grade III gliomas, and recurrent tumors, ALA intensity 3 correlated strongly with cellularity Grade 3; Spearman correlation coefficients (r) were 0.65, 0.66, 0.65, and 0.62, respectively. The specificity and PPV of ALA intensity 3 correlating with cellularity Grade 3 ranged from 95% to 100% and 86% to 100%, respectively. In biopsies without tumor (cellularity Grade 0), 35.4% still demonstrated ALA fluorescence. Of those biopsies, 90.9% contained abnormal brain tissue, characterized by reactive astrocytes, scattered atypical cells, or inflammation, and 8.1% had normal brain. In nonfluorescent (ALA intensity 0) biopsies, 62.3% had tumor cells present. The ALA-associated complication rate among the study cohort was 3.4%. CONCLUSIONS The PPV of utilizing the most robust ALA fluorescence intensity (lava-like orange) as a predictor of tumor presence is high. However, the NPV of utilizing the absence of fluorescence as an indicator of no tumor is poor. ALA intensity is a strong predictor for degree of tumor cellularity for the most fluorescent areas but less so for lower ALA intensities. Even in the absence of tumor cells, reactive changes may lead to ALA fluorescence.

MRI-Derived Restriction Spectrum Imaging Cellularity Index is Associated with High Grade Prostate Cancer on Radical Prostatectomy Specimens

Purpose: We evaluate a novel magnetic resonance imaging (MRI) technique to improve detection of aggressive prostate cancer (PCa).

Materials and Methods: We performed a retrospective analysis of pre-surgical prostate MRI scans using an advanced diffusion-weighted imaging technique called restriction spectrum imaging (RSI), which can be presented as a normalized z-score statistic. Scans were acquired prior to radical prostatectomy. Prostatectomy specimens were processed using whole-mount sectioning and regions of interest (ROIs) were drawn around individual PCa tumors. Corresponding ROIs were drawn on the MRI imaging and paired with ROIs in regions with no pathology. RSI z-score and conventional apparent diffusion coefficient (ADC) values were recorded for each ROI. Paired t-test, ANOVA, and logistic regression analyses were performed.

Results: We evaluated 28 patients with 64 ROIs (28 benign and 36 PCa). The mean difference in RSI z-score (PCa ROI–Benign ROI) was 2.17 (SE = 0.11; p < 0.001) and in ADC was 551 mm²/s (SE = 80 mm²/s; paired t-test, p < 0.001). The differences in the means among all groups (benign, primary Gleason 3, and primary Gleason 4) was significant for both RSI z-score (F_3,64 = 97.7, p < 0.001) and ADC (F_3,64 = 13.9, p < 0.001). A t-test was performed on only PCa tumor ROIs (n = 36) to determine PCa aggressiveness (Gleason 3 vs. Gleason 4) revealing that RSI z-score was still significant (p = 0.03), whereas, ADC values were no longer significant (p = 0.08). In multivariable analysis adjusting for age and race, RSI z-score was associated with PCa aggressiveness (OR 10.3, 95% CI: 1.4–78.0, p = 0.02) while ADC trended to significance (p = 0.07).

Conclusion: The RSI-derived normalized cellularity index is associated with aggressive PCa as determined by pathologic Gleason scores. Further utilization of RSI techniques may serve to enhance standardized reporting systems for PCa in the future.

Adipose depots differ in cellularity, adipokines produced, gene expression, and cell systems

The race to manage the health concerns related to excess fat deposition has spawned a proliferation of clinical and basic research efforts to understand variables including dietary uptake, metabolism, and lipid deposition by adipocytes. A full appreciation of these variables must also include a depot-specific understanding of content and location in order to elucidate mechanisms governing cellular development and regulation of fat deposition. Because adipose tissue depots contain various cell types, differences in the cellularity among and within adipose depots are presently being documented to ascertain functional differences. This has led to the possibility of there being, within any one adipose depot, cellular distinctions that essentially result in adipose depots within depots. The papers comprising this issue will underscore numerous differences in cellularity (development, histogenesis, growth, metabolic function, regulation) of different adipose depots. Such information is useful in deciphering adipose depot involvement both in normal physiology and in pathology. Obesity, diabetes, metabolic syndrome, carcass composition of meat animals, performance of elite athletes, physiology/pathophysiology of aging, and numerous other diseases might be altered with a greater understanding of adipose depots and the cells that comprise them-including stem cells-during initial development and subsequent periods of normal/abnormal growth into senescence. Once thought to be dormant and innocuous, the adipocyte is emerging as a dynamic and influential cell and research will continue to identify complex physiologic regulation of processes involved in adipose depot physiology.

Technical note: Alternatives to reduce adipose tissue sampling bias

Understanding the mechanisms by which nutritional and pharmaceutical factors can manipulate adipose tissue growth and development in production animals has direct and indirect effects in the profitability of an enterprise. Adipocyte cellularity (number and size) is a key biological response that is commonly measured in animal science research. The variability and sampling of adipocyte cellularity within a muscle has been addressed in previous studies, but no attempt to critically investigate these issues has been proposed in the literature. The present study evaluated 2 sampling techniques (random and systematic) in an attempt to minimize sampling bias and to determine the minimum number of samples from 1 to 15 needed to represent the overall adipose tissue in the muscle. Both sampling procedures were applied on adipose tissue samples dissected from 30 longissimus muscles from cattle finished either on grass or grain. Briefly, adipose tissue samples were fixed with osmium tetroxide, and size and number of adipocytes were determined by a Coulter Counter. These results were then fit in a finite mixture model to obtain distribution parameters of each sample. To evaluate the benefits of increasing number of samples and the advantage of the new sampling technique, the concept of acceptance ratio was used; simply stated, the higher the acceptance ratio, the better the representation of the overall population. As expected, a great improvement on the estimation of the overall adipocyte cellularity parameters was observed using both sampling techniques when sample size number increased from 1 to 15 samples, considering both techniques' acceptance ratio increased from approximately 3 to 25%. When comparing sampling techniques, the systematic procedure slightly improved parameters estimation. The results suggest that more detailed research using other sampling techniques may provide better estimates for minimum sampling.

Impact of touch preparations on core needle biopsies

BACKGROUND

Touch preparations (TPs) can be performed for on-site adequacy assessment of core needle biopsies (CNBs). Although TPs can play a role in decreasing the number of nondiagnostic core biopsies, the impact of TPs on CNB has not been extensively evaluated.

METHODS

Computerized tomography-guided CNBs performed in a tertiary cancer center were retrospectively identified. On-site adequacy assessment was performed in all cases. The matching TPs and CNBs were evaluated for diagnostic accuracy of the TP. The relation between the site of biopsy and the cellularity of the CNB was also analyzed.

RESULTS

A total of 1100 CNB cases with associated TPs were identified over a 6-month period. Eighty-four cases (8%) showed marked differences in cellularity between CNB and TP, and 43 of these 84 cases (4.3%) showed the presence of diagnostic cells in either CNB or TP, but not in both. Lung was the biopsy site where CNB was most affected by loss of diagnostic cells.

CONCLUSIONS

TP and CNB findings must be integrated to prevent a misdiagnosis. Lung CNBs were more frequently affected by performing TPs.