Analysis Of Serial Sections Research Articles

Three‐dimensional Characterization of Occlusive Lesions in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) includes a vasculopathy of fixed occlusive lesions in small pulmonary arteries. Evaluation of vascular lesions in PAH has relied on two‐dimensional histological preparations and morphological grading methodologies to evaluate lesion incidence and severity. However, this approach fails to acknowledge the structure of vascular lesions in situ and is inherently prone to investigator bias, leading to controversy regarding the hemodynamic impact of occlusive lesions in PAH and the possible misidentification of lesions within the lung vasculature. Therefore, we developed a semi‐automated, three‐dimensional approach to the analysis of composite serial histological sections to examine the geometry of vascular lesions in PAH. Given that recent studies of vascular morphology in PAH demonstrate that the progression of occlusive lesions has both temporal and spatial components, we tested the hypothesis that occlusive lesions within pulmonary arteries in PAH vary in composition and severity along the length of vessel segments. Using Sugen/hypoxia treated PAH rats, we found that lesion composition and severity was a complex function of vessel length, where von Willebrand factor‐positive endothelium and luminal occlusion surrounding plexiform lesion sites formed a highly variable continuum. These results suggest that the contribution of occlusive lesions to the pathophysiology of PAH may be misrepresented, and underscore the necessity of an unbiased approach to the anatomical characterization of the vasculopathy of PAH.Support or Funding InformationSupported by NIH HL66299 and HL60024.

Abstract P2-05-06: Analytical and clinical validation of a fully automated tissue-based quantitative assay (MetaSite Breast™) to detect the likelihood of distant metastasis in hormone receptor (HR)-positive, HER2-negative early stage breast cancer (ESBC)

Abstract Background: MetaSite Breast™ is a validated assay to predict risk of distant breast cancer metastasis in patients with HR+/HER2- ESBC. The assay measures the number of MetaSites defined as tumor microanatomic structures composed of MENA protein expressing tumor cells in contact with CD31+ endothelial cells and CD68+ macrophages. Previous studies have demonstrated that an increased number of these microanatomic structures is associated with distant metastasis (DM) in HR+/HER2- ESBC independent of clinicopathologic features. Analytical validation of MetaSite Breast™ demonstrated precision of 97-99% (repeat image analysis of the same slide) and performance of 91-96% (staining and image analysis of serial tumor sections). We sought to further understand the importance of the MetaSite in predicting distant breast cancer metastasis utilizing a fully automated prognostic assay in an independent large patient cohort. Methods: We conducted a nested case-control study within a cohort of 3,760 patients diagnosed between 1980 and 2000 with invasive breast cancer from the Kaiser Permanente Northwest health care system. Cases (n=259) were women who developed a subsequent distant metastasis; controls, selected using incidence density sampling, were matched closely to cases (1:1) on age at and calendar year of primary diagnosis. Of the 481 patient tumor samples evaluated in this study, 57% were HR+/HER2-, 19% were triple negative (TN), and 15% were HER2+ disease. Multivariate models were adjusted for clinical factors including: lymph node status, tumor size, tumor grade, and HRT; as well as matching variables: age and year of diagnosis. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression. Results: In the HR+/HER2- group, MetaSite Score (MS) ranged from 0-357 and the mean was 44.6. MS was a significant predictor of DM (P=0.039) in patients with HR+/HER2- disease. Cut-points based on tertiles of MS in all 259 controls defined intermediate (13-41) and high (>41) risk groups that were significantly associated with risk of DM versus the low risk group (OR=2.24; 95%CI=1.23-4.13, P=0.009) and (OR=2.94; 95%CI=1.62-5.41, P=0.0005), respectively. Univariate estimates of absolute risk of DM with cutoffs based on 90% sensitivity and specificity were 9.4% for the low risk group (MS<7), 14.1% for the intermediate (MS=7-91), and 23.4% for the high (MS>91). When adjusted for clinical factors, estimates of absolute risk of DM were 6.6%, 14.1%, and 33.0% for the low, intermediate, and high risk groups, respectively. A binary cut-point for the high risk group was determined (MS>14) and was significant with a 2-fold higher risk of DM versus the low risk group and adjusted for clinical covariates (P=0.036). MS was not positively associated with DM in TN or HER2+ disease. Conclusions: MetaSite Breast™ significantly predicted the risk of distant breast cancer metastasis in ESBC patients with HR+/HER2-disease, independent of classical clinicopathologic features. Citation Format: Donovan MJ, Jones JG, Entenberg DR, Condeelis JS, D'alfonso TM, Gustavson M, Molinaro A, Oktay MH, Xue X, Sparano JA, Peterson MA, Podznyakova O, Rohan TE, Shuber AP, Gertler FB, Ly A, Divelbiss ME, Hamilton DA. Analytical and clinical validation of a fully automated tissue-based quantitative assay (MetaSite Breast™) to detect the likelihood of distant metastasis in hormone receptor (HR)-positive, HER2-negative early stage breast cancer (ESBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-06.

A Comparison of Porosity Analysis Using 2D Stereology Estimates and 3D Serial Sectioning for Additively Manufactured Ti 6Al 2Sn 4Zr 2Mo Alloy

Abstract Porosity is a typical defect in additively manufactured (AM) parts. Such defects limit the properties and performance of AM parts, and therefore need to be characterized accurately. Current methods for characterization of defects and microstructure rely on classical stereological methods that extrapolate information from two dimensional images. The automation of serial sectioning provides an opportunity to precisely and accurately quantify porosity in three dimensions in materials. In this work, we analyzed the porosity of an additively manufactured Ti 6Al 2Sn 4Zr 2Mo sample using Robo-Met.3D®, an automated serial sectioning system. Image processing for three dimensional reconstruction of the serial-sectioned two dimensional images was performed using open source image analysis software (Fiji/ImageJ, Dream.3D, Paraview). The results from this 3D serial sectioning analysis were then compared to classical 2D stereological methods (Saltykov stereological theory). We found that for this dataset, the classical 2D methods underestimated the porosity size and distributions of the larger pores; a critical attribute to fatigue behavior of the AM part. The results suggest that acquiring experimental data with equipment such as Robo-Met.3D® to measure the number and size of particles such as pores in a volume irrespective of knowing their shape is a better choice.

Assessing the Effects of Fibrosis on Lung Function by Light Microscopy-Coupled Stereology.

Pulmonary diseases such as fibrosis are characterized by structural abnormalities that lead to impairment of proper lung function. Stereological analysis of serial tissue sections allows detection and quantitation of subtle changes in lung architecture. Here, we describe a stereology-based method of assessing pathology-induced changes in lung structure.

Sentinel Lymph Node Detection by Blue Dye Versus Indocyanine Green Fluorescence Imaging in Colon Cancer.

Nodal staging is used in colorectal cancer (CRC) to determine which patients should receive adjuvant chemotherapy. The aim of this study was to evaluate the role of indocyanine green fluorescence imaging (ICG-FI) in sentinel lymph node (SLN) detection compared to the standard technique. Twenty patients with CRC admitted for elective colectomy were included (NCT01995591). Ex vivo SLN detection was performed using patent blue (PB) and free ICG injected around the tumor. Identification rates were 95% (19/20) for both techniques. Sensitivity was 43% for PB and 57% for ICG. Correlation between the techniques was 83%. FI was more sensitive in patients with body mass index (BMI) >25 kg/m(2) Serial section analysis did not allow for up-staging of patients. The use of ICG-FI is superior to the blue dye technique in patients with a BMI >25 kg/m(2) However, the sensitivity of ICG-FI in SLN detection remains low, with a high rate of false-negative results.

Techniques and applications of three‐dimensional electron microscopy in entomological research

AbstractStructural studies using two‐dimensional (2D) images show limitations in understanding the structure and functions of cellular organelle and protein. To overcome the difficulty, over the last few years 3D reconstruction techniques using electron microscopy have been developed at extremely high speed. In this paper, currently available 3D reconstruction techniques of electron microscopy (such as electron tomography, serial section analysis and single particle analysis) are introduced using our data as examples of the application. The 3D structure of mitochondria with the defect of mitochondrial protein in round worm, Caenorhabditis elegans, through electron tomography, the cell–cell interaction in lamina of Drosophila melanogaster by serial‐section using ultramicrotome and high‐voltage electron microscopy and a thin filament related to muscle contraction in Drosophila melanogaster were used for examples of the application. These results through 3D reconstruction reveal the structural changes in a cellular organelle and protein that had not been shown by 2D structure.

Sentinel Lymph Node Biopsy for Cutaneous Squamous Cell Carcinoma on the Head and Neck

Metastasis of cutaneous squamous cell carcinoma (SCC) to the nodal basin is associated with a poor prognosis. The role of sentinel lymph node biopsy (SLNB) for regional staging in patients diagnosed with SCC is unclear. To evaluate a single institution's experience with use of SLNB for regional staging of SCC on the head and neck. A retrospective review of 53 patients who were diagnosed with SCC on the head and neck, at high risk for nodal metastasis based on National Comprehensive Cancer Network (NCCN) risk factors, and treated with wide local excision (WLE) and SLNB from December 1, 2010, through January 30, 2015, in a single academic referral center was performed. The follow-up period ended November 5, 2015. Sentinel lymph node biopsy paraffin blocks were retrieved and processed retrospectively with serial sectioning and immunohistochemical analysis (IHC) in cases with nodal recurrence following a negative SLNB. Sentinel node (SN) identification rate, SLNB positivity rate, local recurrence, regional nodal recurrence, and distant recurrence. In 53 patients with 54 tumors the SN identification rate was 94%. The SLNB positivity rate was 11.3%. On more thorough tissue processing and IHC, metastatic SCC was identified in 2 of 5 (40%) cases previously deemed negative. After reclassification of these cases, the adjusted SLNB positivity rate was 15.1%. The adjusted rate of false omission was 7.1% (95% CI, 2%-19%). Nodal disease developed in 20.8% overall. Angiolymphatic invasion (Cohen d, 3.52; 95% CI, 1.83-5.21), perineural invasion (Cohen d, 0.81; 95% CI, 0.09-1.52), and clinical size (Cohen d, 0.83; 95% CI, 0.05-1.63) were associated with the presence of nodal disease. Rigorous study of SLNB for cutaneous SCC incorporating prospectively-collected comprehensive data sets based on standardized treatment algorithms is justified with potential to modify clinical practice. Our study demonstrates the critical importance of serial sectioning and IHC of the SLNB specimen for accurate diagnosis. Use of the NCCN guidelines may facilitate identification of patients with SCC at high risk for nodal metastasis.

Complex epithelial remodeling underlie the fusion event in early fetal development of the human penile urethra

We recently described a two-step process of urethral plate canalization and urethral fold fusion to form the human penile urethra. Canalization (“opening zipper”) opens the solid urethral plate into a groove, and fusion (“closing zipper”) closes the urethral groove to form the penile urethra. We hypothesize that failure of canalization and/or fusion during human urethral formation can lead to hypospadias. Herein, we use scanning electron microscopy (SEM) and analysis of transverse serial sections to better characterize development of the human fetal penile urethra as contrasted to the development of the human fetal clitoris.Eighteen 7–13 week human fetal external genitalia specimens were analyzed by SEM, and fifteen additional human fetal specimens were sectioned for histologic analysis. SEM images demonstrate canalization of the urethral/vestibular plate in the developing male and female external genitalia, respectively, followed by proximal to distal fusion of the urethral folds in males only. The fusion process during penile development occurs sequentially in multiple layers and through the interlacing of epidermal “cords”. Complex epithelial organization is also noted at the site of active canalization. The demarcation between the epidermis of the shaft and the glans becomes distinct during development, and the epithelial tag at the distal tip of the penile and clitoral glans regresses as development progresses.In summary, SEM analysis of human fetal specimens supports the two-zipper hypothesis of formation of the penile urethra. The opening zipper progresses from proximal to distal along the shaft of the penis and clitoris into the glans in identical fashion in both sexes. The closing zipper mechanism is active only in males and is not a single process but rather a series of layered fusion events, uniquely different from the simple fusion of two epithelial surfaces as occurs in formation of the palate and neural tube.

Jaw myogenesis in the monk parakeet: evidence of developmental reprogramming in the emergence of novel muscles in Psittaciformes (Aves)

Psittaciformes have apomorphies in the muscles of the jaw that include both the adductors m. ethmomandibularis (EM) and m. pseudomasseter (PM), which are responsible for the generation of strong bite forces. While the EM is present in all Psittaciformes, the PM can be absent or present, and even underdeveloped or well-developed. The aim of this study is to identify developmental reprogramming processes by comparing the myogenesis of the jaw of the monk parakeet Myiopsitta monachus with the information available about other species of Psittaciformes. Seventeen specimens including embryos at different developmental stages, and nestlings of different ages were studied through the analysis of serial histological sections. At embryonic stage 24 (S24) the muscle precursor was observed in the first pharyngeal arch. At S27 the muscle precursor was found to be divided into lateral, intermediate and medial portions. At S31 the independent development of the EM as a rostro-dorsal projection of the mm. pterygoidei could be observed. At S36 the individualization of all muscles was complete. Finally, the PM was detected two days after hatching as an aponeurotic dorsal projection of the m. adductor mandibulae externus superficialis, located lateral to the arcus jugalis. Our results suggest that in M. monachus the muscles EM and PM emerge as a result of a process of heterotipy, and variations in the degree of development of the PM are associated to a heterochronic process of post-displacement, with M. monachus having an underdeveloped PM with respect to basal Psittaciformes.

Characterization of Kidney and Skeleton Phenotypes of Mice Double Heterozygous for Foxc1 and Foxc2

Foxc1 and Foxc2 play key roles in mouse development. Foxc1 mutant mice develop duplex kidneys with double ureters, and lack calvarial and sternal bones. Foxc2 null mice have been reported to have glomerular abnormalities in the kidney and axial skeletal anomalies. Expression patterns of Foxc1 and Foxc2 overlap extensively and are believed to have interactive roles. However, cooperative roles of these factors in glomerular and skeletal development are unknown. Therefore, we examined the kidneys and skeleton of mice that were double heterozygous for Foxc1 and Foxc2. Double heterozygotes were generated by mating single heterozygotes for Foxc1 and Foxc2. Newborn double heterozygous mice showed many anomalies in the kidney and urinary tract resembling Foxc1 phenotypes, including duplex kidneys, double ureters, hydronephrosis and mega-ureter. Some mice had hydronephrosis alone. In addition to these macroscopic anomalies, some mice had abnormal glomeruli and disorganized glomerular capillaries observed in Foxc2 phenotypes. Interestingly, these mice also showed glomerular cysts not observed in the single-gene knockout of either Foxc1 or Foxc2 but observed in conditional knockout of Foxc2 in the kidney. Serial section analysis revealed that all cystic glomeruli were connected to proximal tubules, precluding the possibility of atubular glomeruli resulting in cyst formation. Dorsally opened vertebral arches and malformations of sternal bones in the double heterozygotes were phenotypes similar to Foxc1 null mice. Absent or split vertebral bodies in the double heterozygotes were phenotypes similar to Foxc2 null mice, whilst hydrocephalus noted in the Foxc1 phenotype was not observed. Thus, Foxc1 and Foxc2 have a role in kidney and axial skeleton development. These transcription factors might interact in the regulation of the embryogenesis of these organs.

Functional Effects of Delivering Human Mesenchymal Stem Cell-Seeded Biological Sutures to an Infarcted Heart.

Stem cell therapy has the potential to improve cardiac function after myocardial infarction (MI); however, existing methods to deliver cells to the myocardium, including intramyocardial injection, suffer from low engraftment rates. In this study, we used a rat model of acute MI to assess the effects of human mesenchymal stem cell (hMSC)-seeded fibrin biological sutures on cardiac function at 1 week after implant. Biological sutures were seeded with quantum dot (Qdot)-loaded hMSCs for 24 h before implantation. At 1 week postinfarct, the heart was imaged to assess mechanical function in the infarct region. Regional parameters assessed were regional stroke work (RSW) and systolic area of contraction (SAC) and global parameters derived from the pressure waveform. MI (n = 6) significantly decreased RSW (0.026 ± 0.011) and SAC (0.022 ± 0.015) when compared with sham operation (RSW: 0.141 ± 0.009; SAC: 0.166 ± 0.005, n = 6) (p < 0.05). The delivery of unseeded biological sutures to the infarcted hearts did not change regional mechanical function compared with the infarcted hearts (RSW: 0.032 ± 0.004, SAC: 0.037 ± 0.008, n = 6). The delivery of hMSC-seeded sutures exerted a trend toward increase of regional mechanical function compared with the infarcted heart (RSW: 0.057 ± 0.011; SAC: 0.051 ± 0.014, n = 6). Global function showed no significant differences between any group (p > 0.05); however, there was a trend toward improved function with the addition of either unseeded or seeded biological suture. Histology demonstrated that Qdot-loaded hMSCs remained present in the infarcted myocardium after 1 week. Analysis of serial sections of Masson's trichrome staining revealed that the greatest infarct size was in the infarct group (7.0% ± 2.2%), where unseeded (3.8% ± 0.6%) and hMSC-seeded (3.7% ± 0.8%) suture groups maintained similar infarct sizes. Furthermore, the remaining suture area was significantly decreased in the unseeded group compared with that in the hMSC-seeded group (p < 0.05). This study demonstrated that hMSC-seeded biological sutures are a method to deliver cells to the infarcted myocardium and have treatment potential.

Unilateral Impact of Altered Loading by Changing Teeth Height on the TMJ Fibrocartilage: Disc and Condyle of Wistar Rats

Temporomandibular joint (TMJ) is sensitive to loading and mechanical stress that provokes morphological changes produced by the impact in the occlusal plane. Here, this impact is evaluated in TMJ articular disc and articular cartilage using an in vivo model of unilateral occlusal plane impact and by analysis of serial tissue sections stained with Hematoxylin-Eosin (H-E) or with Masson trichrome technique. Thus, six groups of 5 Wistar rats (200 - 250 g) are subjected to biomechanical dental stimulation by placing unilateral resin occlusal interference, or unilateral tooth wear made by upper left molars artificial mechanical devastation (1 control and 2 experimental groups for each treatment). Each treatment is evaluated two times at 1 and 15 days post-treatment. By H-E staining, control groups show chondrocytes arrangement as several cord cell groups in comparison with the experimental groups, which show an arrangement in one cord cell along of articular disc. However, this yields no significant difference (p < 0.05) in cell number between control and experimental groups. In contrast, in articular cartilage chondrocytes are random distributed along the superficial zone in control groups, while in experimental groups cell-free regions are observed in superficial zone. An image Blue hue analysis for trichrome stain is performed to quantify collagen; this shows a significant collagen decrease (p < 0.05) in almost all experimental groups compared with the controls. A degenerative process biomechanically induced by unilateral occlusal plane modification, causes cell and tissue changes on the TMJ structures that remain the degenerative changes observed in early osteoarthritis.

Effect of Associative Learning on Memory Spine Formation in Mouse Barrel Cortex.

Associative fear learning, in which stimulation of whiskers is paired with mild electric shock to the tail, modifies the barrel cortex, the functional representation of sensory receptors involved in the conditioning, by inducing formation of new inhibitory synapses on single-synapse spines of the cognate barrel hollows and thus producing double-synapse spines. In the barrel cortex of conditioned, pseudoconditioned, and untreated mice, we analyzed the number and morphological features of dendritic spines at various maturation and stability levels: sER-free spines, spines containing smooth endoplasmic reticulum (sER), and spines containing spine apparatus. Using stereological analysis of serial sections examined by transmission electron microscopy, we found that the density of double-synapse spines containing spine apparatus was significantly increased in the conditioned mice. Learning also induced enhancement of the postsynaptic density area of inhibitory synapses as well as increase in the number of polyribosomes in such spines. In single-synapse spines, the effects of conditioning were less pronounced and included increase in the number of polyribosomes in sER-free spines. The results suggest that fear learning differentially affects single- and double-synapse spines in the barrel cortex: it promotes maturation and stabilization of double-synapse spines, which might possibly contribute to permanent memory formation, and upregulates protein synthesis in single-synapse spines.

MPTH-29CONNECTING MUTANT GENOTYPES TO ABERRANT TRANSCRIPTIONAL SIGNATURES ACROSS SERIAL SECTIONS OF A HUMAN TUMOR

Identifying the transcriptional consequences of mutations that cause tumors may reveal new targets for the development of cancer therapies. However, this task is complicated by the variability that characterizes tumors from different individuals, which arise from unique genetic backgrounds, consist of various cell types in different proportions, and often exhibit clonal heterogeneity. Here we present a novel strategy to connect mutant genotypes to aberrant transcriptional signatures within individual human tumors. This strategy deconstructs a tumor by extracting RNA from serial sections and comparing genome-wide gene coexpression relationships to control samples analyzed in a similar fashion. In parallel, quantitative genomic analysis of the same serial sections enables identification and mapping of clonal populations within the tumor. We apply this strategy to a single grade II human astrocytoma and identify tumor-specific transcriptional signatures. Genomic analysis reveals clonal heterogeneity, including a dominant clone marked by mutations in IDH1 and TP53. Expression patterns of the two largest tumor-specific transcriptional signatures are almost perfectly associated with the spatial distribution of the dominant clone and consist of genes that are activated or repressed within malignant cells and their microenvironment. Our experimental strategy offers an unbiased and personalized method for identifying aberrant transcriptional signatures that are associated with specific mutant genotypes in any solid tumor while preserving the complex cellular milieu of the tumor microenvironment. More generally, this strategy can reveal shared and distinct patterns of transcriptional organization between any pair of tissue samples, thereby facilitating novel comparisons of diverse biological systems in health and disease.

Novel bio-spectroscopic imaging reveals disturbed protein homeostasis and thiol redox with protein aggregation prior to hippocampal CA1 pyramidal neuron death induced by global brain ischemia in the rat

Global brain ischemia resulting from cardiac arrest and cardiac surgery can lead to permanent brain damage and mental impairment. A clinical hallmark of global brain ischemia is delayed neurodegeneration, particularly within the CA1 subsector of the hippocampus. Unfortunately, the biochemical mechanisms have not been fully elucidated, hindering optimization of current therapies (i.e., therapeutic hypothermia) or development of new therapies. A major limitation to elucidating the mechanisms that contribute to neurodegeneration and understanding how these are influenced by potential therapies is the inability to relate biochemical markers to alterations in the morphology of individual neurons. Although immunocytochemistry allows imaging of numerous biochemical markers at the sub-cellular level, it is not a direct chemical imaging technique and requires successful “tagging” of the desired analyte. Consequently, important biochemical parameters, particularly those that manifest from oxidative damage to biological molecules, such as aggregated protein levels, have been notoriously difficult to image at the cellular or sub-cellular level. It has been hypothesized that reactive oxygen species (ROS) generated during ischemia and reperfusion facilitate protein aggregation, impairing neuronal protein homeostasis (i.e., decreasing protein synthesis) that in turn promotes neurodegeneration. Despite indirect evidence for this theory, direct measurements of morphology and ROS induced biochemical damage, such as increased protein aggregates and decreased protein synthesis, within the same neuron is lacking, due to the unavailability of a suitable imaging method. Our experimental approach has incorporated routine histology with novel wide-field synchrotron radiation Fourier transform infrared imaging (FTIRI) of the same neurons, ex vivo within brain tissue sections. The results demonstrate for the first time that increased protein aggregation and decreased levels of total protein occur in the same CA1 pyramidal neurons 1 day after global ischemia. Further, analysis of serial tissue sections using X-ray absorption spectroscopy at the sulfur K-edge has revealed that CA1 pyramidal neurons have increased disulfide levels, a direct indicator of oxidative stress, at this time point. These changes at 1 day after ischemia precede a massive increase in aggregated protein and disulfide levels concomitant with loss of neuron integrity 2 days after ischemia. Therefore, this study has provided direct support for a correlative mechanistic link in both spatial and temporal domains between oxidative stress, protein aggregation and altered protein homeostasis prior to irreparable neuron damage following global ischemia.

Circadian rhythmicity of synapses in mouse somatosensory cortex.

The circadian rhythmicity displayed by motor behavior of mice: activity at night and rest during the day; and the associated changes in the sensory input are reflected by cyclic synaptic plasticity in the whisker representations located in the somatosensory (barrel) cortex. It was not clear whether diurnal rhythmic changes in synapse density previously observed in the barrel cortex resulted from changes in the activity of the animals, from daily light/dark (LD) rhythm or are driven by an endogenous clock. These changes were investigated in the barrel cortex of C57BL/6 mouse strain kept under LD 12:12h conditions and in constant darkness (DD). Stereological analysis of serial electron microscopic sections was used to assess numerical density of synapses. In mice kept under LD conditions, the total density of synapses and the density of excitatory synapses located on dendritic spines was higher during the light period (rest phase). In contrast, the density of inhibitory synapses located on dendritic spines increased during the dark period (activity phase). Under DD conditions, the upregulation of the inhibitory synapses during the activity phase was retained, but the cyclic changes in the density of excitatory synapses were not observed. The results show that the circadian plasticity concerns only synapses located on spines (and not those on dendritic shafts), and that excitatory and inhibitory synapses are differently regulated during the 24h cycle: the excitatory synapses are influenced by light, whilst the inhibitory synapses are driven by the endogenous circadian clock.

Profiling of adrenocorticotropic hormone and arginine vasopressin in human pituitary gland and tumor thin tissue sections using droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS.

Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections, using a fully automated droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS system for spatially resolved sampling, HPLC separation, and mass spectrometric detection. Excellent correlation was found between the protein distribution data obtained with this method and data obtained with matrix-assisted laser desorption/ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis), and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH-secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH-secreting adenomas and in normal anterior adenohypophysis compared with non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis, as expected. This work reveals that a fully automated droplet-based liquid-microjunction surface-sampling system coupled to HPLC-ESI-MS-MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, including AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity, and specificity of this method support the potential of this basic technology, with further advancement, for assisting surgical decision-making. Graphical Abstract Mass spectrometry based profiling of hormones in human pituitary gland and tumor thin tissue sections.

Altered intrahepatic microcirculation of idiopathic portal hypertension in relation to glutamine synthetase expression.

Alteration in intrahepatic microcirculation of idiopathic portal hypertension (IPH) has been poorly understood. This study aimed to characterize altered intrahepatic microcirculation of IPH focusing on the expression pattern of glutamine synthetase (GS). Immunohistochemical staining of GS was performed using liver sections of IPH (n = 28). Serial section analysis was performed to determine microcirculatory disturbances of IPH. Paraportal shunt vessels were observed in 20 cases of IPH, and they were divided into two types according to the GS staining pattern; hepatocytes surrounding the vessels were negative for GS (type 1) and positive for GS (type 2). All 20 cases had one or more type 1 vessels within a section, and 10 cases were further associated with type 2 vessels. The cases with type 2 vessels showed infrequent symptoms of esophageal varices. Regarding the GS staining as an indicator of hepatic veins, some type 2 vessels were supposed to represent portovenous shunts. Isolated arteries in hepatic parenchyma were present in 21 cases, and they were located around terminal hepatic venules in six cases, corresponding to centrizonal arteries. Broad hepatocellular GS staining in hyperplastic lesions was noted in five cases, whereas nodular regenerative hyperplasia lacked GS expression. GS immunostaining revealed microcirculatory disturbances of IPH that were associated with abnormalities in both venous and arterial vessels.

Identification of four Aconitum species used as "Caowu" in herbal markets by 3D reconstruction and microstructural comparison.

Authentication is the first priority when evaluating the quality of Chinese herbal medicines, particularly highly toxic medicines. The most commonly used authentication methods are morphological identification and microscopic identification. Unfortunately, these methods could not effectively evaluate some herbs with complex interior structures, such as root of Aconitum species with a circular conical shape and an interior structure with successive changes. Defining the part that should be selected as the standard plays an essential role in accurate microscopic identification. In this study, we first present a visual 3D model of Aconitum carmichaeli Debx. constructed obtained from microscopic analysis of serial sections. Based on this model, we concluded that the point of largest root diameter should be used as the standard for comparison and identification. The interior structure at this point is reproducible and its shape and appearance can easily be used to distinguish among species. We also report details of the interior structures of parts not shown in the 3D model, such as stone cells and cortical thickness. To demonstrate the usefulness of the results from the 3D model, we have distinguished the microscopic structures, at their largest segments, of the other three Aconitum species used for local habitat species of Caowu. This work provides the basis for resolution of some debate regarding the microstructural differences among these species. Thus, we conclude that the 3D model composed of serial sections has enabled the selection of a standard cross-section that will enable the accurate identification of Aconitum species in Chinese medicine.

Therapeutic effectiveness of bone marrow-derived mesenchymal stem cell administration against acute pulmonary thromboembolism in a mouse model

InstructionAcute pulmonary thromboembolism (APTE) is a common clinical condition associated with significant morbidity and mortality. Although promising, bone marrow-derived mesenchymal stem cell (BMSC) treatment for thrombus resolution remains controversial. The therapeutic effectiveness of BMSC against APTE has not been evaluated. This study aims to determine whether BMSCs administration is effective in mouse model. Materials and MethodsTherapeutic efficacy of female and male BMSCs were evaluated by applying serial sectioning analysis method for the whole lungs of APTE mice and calculating each thrombus size in volume. Plasmid construction and stable transfection were used to manipulate expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in both genders of BMSCs. Western blot were performed to detect GAPDH and urokinase plasminogen activator expression in BMSCs. ResultsOur data showed, 1) compared with non-serial sectioning method, the serial sectioning method detected more thrombi, larger size ranges of thrombus area, and the volume of each individual thrombus. 2) BMSCs significantly decreased the thrombi size in APTE mice, with female BMSCs superior to male ones. 3) female BMSCs showed a higher GAPDH protein level and manipulations of GAPDH expression in female or male BMSCs profoundly affected their therapeutic efficacies as well as urokinase plasminogen activator expression. ConclusionThis study indicates serial-sectioning analysis method is necessary for evaluating APTE and provides strong evidences for BMSCs possessing therapeutic effectiveness against APTE, with female BMSCs superior to male counterparts. GAPDH played a critical role in the superior function of female BMSCs, possibly by regulating the expression of urokinase plasminogen activator.