The existence of senescent cells in conjunctival epithelium from elderly individuals.

PURPOSE: The ocular surface microenvironment changes with aging. However, it remains unclear if cellular senescence influences the ocular surface. We investigated the presence of p16INK4a-expressing senescent cells in healthy human conjunctiva. STUDY DESIGN: Clinical and experimental. METHODS: Healthy conjunctival tissue samples were obtained from middle-aged and elderly subjects. RT-qPCR was performed to assess the expression of senescence markers CDKN2A (p16INK4a) and CDKN1A (p21CIP1/WAF1) and immunostaining was performed to examine the expression of the senescence marker p16INK4a, stem cell markers Ki67 and p63, tight-junction marker ZO-1. RESULTS: Our study involved 19 conjunctival tissue samples (10 elderly and 9 middle-aged), mean age [elderly: 75.8 ± 3.7 years (72-81), middle-aged: 52.7 ± 7 years (38-59)], sex (elderly: 3 men, 7 women; middle-aged: 3 men, 6 women). The expression of p16INK4a was significantly increased at the RNA level in the elderly compared to middle-aged (p < 0.05). Positivity rate of p16INK4a was significantly elevated in the elderly (15.0 ± 7.8%) compared to middle-aged (0.2 ± 0.6%) (p < 0.05). Positivity rate of Ki67and p63 was significantly reduced in the elderly (1.7 ± 1.7% and 16.5 ± 9.5%) compared to middle-aged (3.9 ± 1.8% and 24.7 ± 5.7%) (p < 0.05). ZO-1 expression was reduced in tissue samples showing p16INK4a-positivity but retained in tissue samples in which p16INK4a was undetectable. CONCLUSIONS: Senescent cells accumulate with age in the conjunctival epithelium, accompanied by a decrease in Ki67, p63 and ZO-1 expressing cells.

Multiplexed transcriptional profiling of Dermatophagoides house dust mites allergens in human epithelium cells.

Allergic asthma, a chronic disease characterized by airway inflammation, poses a significant public health concern. It is well-established that house dust mites (HDMs) are common inducers of allergic responses in individuals, particularly children. In central Taiwan, our research team observed that over 80% of allergic children exhibited sensitization to various HDMs species. This investigation aims to bridge the gap between these observations and a better understanding of the early fundamental mechanisms for preventing allergic diseases. Specifically, our study delves into the impact of crude extracts of HDMs on human epithelial BEAS-2B cells. Our findings, based on RNA sequencing (RNA-seq) analysis, shed light on how three major Dermatophagoides HDMs allergens activate a common Toll-like receptor signaling pathway in human epithelial cells within a 4-h treatment. During this process, the nuclear transcription factor NF-κB translocated into the cell nucleus within 30 min of allergen stimulation, triggering the expression of pro-inflammatory genes such as IL-6 and IL-8 over 4 h. Additionally, when the cells were treated with specific Dermatophagoides microceras (Der m) allergens, it resulted in the upregulation of genes that regulate type 1 diabetes mellitus (T1DM) signaling pathways. This led to the mediation of IL-12A inflammation. Furthermore, there was an increase in gene sets associated with cilia function and the microtubule cytoskeleton in human epithelial cells after treatment with a combination of Der m allergens and Dexamethasone. Additionally, OMICs analysis was conducted to examine the effects of HDMs allergenic stimulation on human epidermal cells. We aimed to improve our understanding of the molecular mechanisms within cells and identify potential targets and natural products in the treatment of asthma caused by HDMs allergens.

Combined exposure of MAHs and PAHs enhanced amino acid and lipid metabolism disruption in epithelium leading asthma risk.

Monoaromatic hydrocarbons (MAHs) and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous air pollutants from industry, with multiple adverse effects on respiratory system. However, the underlying mechanisms of their mixture to induce asthma is still unclear. Here, we examined mixture of 8 MAHs, mixture of 16 PAHs and a total mixture (MIX) on human bronchial epithelial (16-HBE) cells. Exposure to MIX resulted in increased expressions of asthma alarm cytokines (TSLP, IL-25 and IL-33), indicating potential asthma risk. Exposure to MIX led to significant upregulation of transcriptional level of oxidative stress and inflammation biomarkers through aryl hydrocarbon receptor activation, including SOD-2, NQO-1, IL-1ß, IL-6 and IL-8 with 3.1, 19.9, 3.5, 23.4, 18.7, 28.1-fold change, indicated asthma related epithelial cell lesions. A total of 25, 49 and 59 differential metabolites were identified in cells response to MAH, PAH and MIX exposure, respectively, and enrichment analysis demonstrated MIX exposure disturbing alanine, aspartate and glutamate metabolism, glutathione metabolism, methionine metabolism and sphingolipid metabolism, involved in antioxidative defense and inflammation response. Combined exposure of MAHs and PAHs may result in increased toxic risks, and provide evidence to asthma onset and deterioration.

[Monkeypox with eccrine duct involvement]. / Viruela del mono con afectación de conductos ecrinos.

Monkeypox was historically considered a zoonotic disease restricted to areas with an animal reservoir and with limited possibilities of human transmission. However, the recent increase in incidence in non-endemic areas, together with the demonstration of human transmission, has led to more attention being paid to this disease. We present the case of a 27-year-old man with cutaneous lesions and perianal ulcers, clinically suggestive of a viral disease. Monkeypox was demonstrated with PCR analysis. The histological features and differential diagnoses of monkeypox are discussed and the characteristic histopathological pattern of eccrine gland epithelium is described which, if found in an ulcerated lesion, should raise suspicion of monkeypox.

Clinical Characteristics and Sensitization Profile of Patients Allergic to Cow Epithelium.

INTRODUCTION: Cow epithelium allergy (CEA) has been described in workers highly exposed to cattle, such as farmers and veterinarians, being a health problem in this population since it is their main livelihood. This study aimed to characterize the main clinical manifestations and define the sensitization profile of the cow epithelium-allergic population treated in our health area. METHODS: This is a retrospective study including a total of 34 patients with a clinical diagnosis of CEA, confirmed by skin tests, bovine epithelium-specific IgE levels and allergen-specific conjunctival challenge test in some cases. They were distributed by age, sex, profession, clinical symptoms, specific IgE levels to other mammalian epithelia, pollens, mites, and foods. Immunoblotting was performed with extracts from cow dander, cow body fluids (urine and saliva), bull urine, and 17 sera from immunotherapy-untreated CEA patients. RESULTS: The mean age of the patients was 44 years, with a higher incidence in cattle farmers. Rhinoconjunctivitis occurred in 100% of cases, with 35% having monosensitization to cow epithelium. Sera from most patients detected a 20-kDa IgE-binding band in cow dander, cow saliva, cow urine, and bull urine, corresponding to the major allergen Bos d 2 (bovine lipocalin). In 70% of the patients, a 25-kDa band was detected in cow and bull urine extracts, whose identification by mass spectrometry and investigation with protein databases led to the identification of a Bos taurus lipocalin (UniProt protein ID: A0A3Q1LGU7_BOVIN). CONCLUSION: CEA should be considered in patients exposed to cattle and as a cause of occupational disease. The IgE immunodetection revealed sensitization to a protein present in cow and bull urine (odorant-binding protein) not previously described.

A novel junctional epithelial cell line, mHAT-JE01, derived from incisor epithelial cells.

OBJECTIVES: Junctional epithelium (JE) connects the tooth surface and gingival epithelium and adheres directly to the tooth enamel. JE plays an important role as a barrier preventing the invasion of exogenous bacteria and substances. However, the cellular characteristics of this epithelium have not been adequately described, because no useful in vitro experimental model exists for JE. METHODS: We generated a novel JE cell line, mHAT-JE01, using naturally immortalized dental epithelium derived from incisor labial cervical cells and by selecting cells that adhered to apatite. mHAT-JE01 was characterized by immunohistochemistry and quantitative reverse transcription-polymerase chain reaction and compared with the gingival epithelial cell line, mOE-PE01. RESULTS: The mHAT-JE01 cells had a higher capacity for producing JE-specific markers than oral mucous epithelial cells. In addition, the presence of lipopolysaccharides from Porphyromonas gingivalis downregulated the expression of JE protein markers in mHAT-JE01 cells. CONCLUSIONS: This cell line is stable and presents the opportunity to characterize JE efficiently, which is essential for the prevention and treatment of periodontal disease.

Innovative graph analysis method to assess gene expression modulation after fine particles exposures of 3D human airway epithelia.

Environmental particles have dramatic consequences for health, especially for the most vulnerable people, such as asthmatics. To better understand the impact on gene expression modulation of fine particles (PM2.5-0.3) from different emission sources, a 3D-airway model, a human bronchial epithelium (MucilAir-HF™) reconstructed from primary cells from healthy (EpiH) or asthmatic (EpiA) donors, was used. Repeated air-liquid exposures were performed, and epithelia were sacrificed to extract RNAs and assess gene expression. Data were analyzed according to the emission sources, physiological status, and exposure doses using a recent model consisting in a graph analysis on pairwise expression ratio. The results were compared with those from the classical ΔΔCt method. The graph analysis method proved to have better statistical properties than the classical ΔΔCt method and demonstrated that repeated PM2.5-0.3 exposures induced a dose-dependent up-regulation of the metabolic gene (CYP1B1) and a down-regulation of the inflammation gene (CXCL10). These modulations were greater for "industrial" than for "urban traffic" fine particles, and the effects were found to be greater after exposure of EpiA than EpiH, thus emphasizing the importance of the epithelium's physiological status in sensitivity to particles. Our study is original in terms of the experimental conditions and the graphical statistical analysis model established. The results highlight the importance of particle chemistry on the modulation of cellular and molecular responses, which may vary according to the individual's vulnerability.

Desmoplastic Adamantinoma-like Thymic Carcinoma: Clinicopathologic, Immunohistochemical, and Molecular Study of 5 Cases.

Five cases of a heretofore unreported rare variant of thymic carcinoma characterized by a striking resemblance to adamantinoma of the mandible are described. The tumors occurred in 4 women and 1 man aged 58 to 76 years (mean: 67.8 y); they arose in the anterior mediastinum and measured from 5.3 to 12.0 cm in greatest diameter (mean: 8.9 cm). Presenting symptoms included chest pain, shortness of breath, and in 2 patients, pleural effusion. One tumor was asymptomatic and discovered incidentally. Histologically, the tumors were extensively desmoplastic, and the cellular proliferation was characterized by multiple islands of squamous epithelium with striking peripheral palisading of nuclei and central areas containing clear cells resembling a stellate reticulum. Areas of preexisting spindle cell thymoma were identified in 2 cases; these areas gradually merged with the higher-grade component of the lesion. Cystic changes were noted in 3 cases. Immunohistochemical studies in 3 cases showed the tumor cells were positive for cytokeratins, p40 and p63, and all showed a high proliferation rate (>50% nuclear positivity) with Ki-67. Next-generation sequencing was performed in 2 cases that showed amplification of the AKT1 gene (copy numbers 6 and 13). Clinical follow-up in 3 patients showed recurrence and metastasis after 1 and 2 years; 1 patient passed away 2 years after diagnosis due to the tumor. Desmoplastic adamantinoma-like thymic carcinoma represents an unusual histologic variant of thymic carcinoma that needs to be distinguished from metastases from similar tumors to the mediastinum.

Quantitative Assessment of Epithelial Proliferation in Rat Mammary Gland Using Artificial Intelligence Independent of Choice of Proliferation Marker.

Epithelial proliferation in the rat mammary gland is recommended in regulatory guidelines as an endpoint for assessment of the in vivo carcinogenic potential of insulin analogues. Epithelial proliferation is traditionally assessed by immunohistochemical staining of a proliferation marker, for example, 5-bromo-2'-deoxyuridine (BrdU) or Ki67, followed by labor-intensive manual counting of positive and negative cells. The aim of this study was to develop and validate an approach for image analysis based on artificial intelligence, which can be used for quantification of proliferation in rat mammary gland, independent of the choice of proliferation marker. Furthermore, the aim was to compare the markers BrdU, Ki67, and phosphorylated histone H3 (PHH3). A sequence of image analysis applications were developed, which allowed for quantification of proliferative activity in the mammary gland epithelium. These endpoints agreed well with manually counted labeling indices, with correlation coefficients in the range ≈0.92-0.93. In addition, all three proliferation markers were significantly correlated and could detect the variation in epithelial proliferation during the estrous cycle. In conclusion, image analysis can be used to quantify epithelial proliferation in the rat mammary gland and thereby replace time-consuming manual counting. Furthermore, BrdU, Ki67, and PHH3 can be used interchangeably to assess proliferation.

Expression of Markers Ki-67, Nestin, VEGF, CD34 and Apoptosis in Relatively Healthy Lung Tissue with Non-Changed and Metaplastic Bronchial Epithelium.

BACKGROUND: Knowledge about the occurrence of processes such as proliferation, apoptosis and angiogenesis in healthy lung tissues with different bronchial epitheliums is limited, and further exploration can contribute to a better understanding of the physiological renewal of lung tissues. The processes mentioned above occur with the help of important tissue factors; therefore, the aim of the study was to determine the expression of markers Ki-67, nestin, CD34 and vascular endothelial growth factor (VEFG) and detect apoptotic cells in relatively healthy lung tissue. METHODS: Samples of relatively healthy lung tissue were obtained from 19 patients and divided into groups of patients with non-changed and patients with metaplastic bronchial epithelium. Tissue samples were examined by hematoxylin and eosin staining. Ki-67, nestin, VEGF and CD34-positive cells were detected by the immunohistochemistry method. Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay was carried out to detect apoptotic cells. The number of positive structures was counted semi-quantitatively by microscopy. RESULTS: Ki-67-positive cells were detected in only one case. An occasional to moderate number of nestin-positive structures was found in various tissues of relatively healthy lungs with different bronchial epitheliums. No apoptotic cells were seen in non-changed bronchial epithelium, compared with few apoptotic cells in metaplastic bronchial epithelium. Metaplastic bronchial epithelium contained more VEGF-positive cells than non-changed bronchial epithelium. Samples with non-changed, and metaplastic bronchial epithelium both contained a similar number of CD34-positive structures. CONCLUSIONS: Proliferative activity and programmed cell death are not prominent events in normal lung tissue. A moderate number of nestin-positive cells in the alveolar epithelium and cartilage of bronchi with pseudostratified ciliated epithelium suggests a significant role of neuronal origin cells in these structures, to be intensified in metaplastic bronchial epithelium. A practically non-changed number of CD34-positive cells excludes any difference in stimulation of endothelial origin cells between lungs with different types of epithelium, while an increase in VEGF in structures with metaplastic epithelium suggests the presence/influence of tissue ischemia impact on possible development/maintenance of metaplasia.

A High-Fructose Diet Formulated with Thermally Oxidized Monounsaturated Fat Aggravates Metabolic Dysregulation in Colon Epithelial Tissues of Rats.

BACKGROUND: Various epidemiological and clinical studies have indicated a positive association of colon cancer with high sugar and thermally oxidized fats consumption. The present study evaluated the effects of fresh and thermally oxidized coconut (CO) and mustard oils (MO) along with a high-sugar diet in the rat colon mucosa. METHODS: The animals were fed with a modified diet containing high-fructose and different edible oils as fatty acids sources over a period of 30 weeks. Further, the development of insulin resistance and hyperglycemia were estimated biochemically. The changes in the redox status were estimated in terms of reduced glutathione (GSH), antioxidant enzymes and thiobarbituric acid reactive substances (TBARS). Changes in the expression of genes associated with inflammation and cell proliferation were evaluated by qPCR. RESULTS: The animals fed with high-fructose developed hyperglycemia and insulin resistance over 30 weeks. These animals had diminished GSH level, SOD activity and a concomitant increase in the TBARS level in the colon epithelial tissues. In addition, the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was elevated while P53 and PPARγ were down-regulated. This heightened body metabolic dysregulation and associated oxidative damage and inflammation in the colon were exacerbated by thermally oxidized edible oils incorporated in the diet, with a more prominent effect was observed with TMO. CONCLUSION: Feeding high-fructose diet with TMO increases the oxidative and inflammatory damages in the colon epithelium of Wistar rats. Therefore, the study cautions the prolonged consumption of thermally oxidized monounsaturated fat-rich edible oils, especially by individuals with type 2 diabetes.

Identification of remodeled collagen fibers in tumor stroma by FTIR Micro-spectroscopy: A new approach to recognize the colon carcinoma.

The tumor stroma plays a pivotal role in colon cancer genesis and progression. It was observed that collagen fibers in the extracellular matrix (ECM) of cancer stroma, undergo a strong remodeling. These fibrous proteins result more aligned and compact than in physiological conditions, creating a microenvironment that favors cancer development. In this work, micro-FTIR spectroscopy was applied to investigate the chemical modifications in the tumor stroma. Using Fuzzy C-means clustering, mean spectra from diseased and normal stroma were compared and collagen was found to be responsible for the main differences between them. Specifically, the modified absorptions at 1203, 1238, 1284 cm-1 and 1338 cm-1 wavenumbers, were related to the amide III band and CH2 bending of side chains. These signals are sensitive to the interactions between the α-chains in the triple helices of collagen structure. This provided robust chemical evidence that in cancer ECM, collagen fibers are more parallelized, stiff and ordered than in normal tissue. Principal Component Analysis (PCA) applied to the spectra from malignant and normal stroma confirmed these findings. Using LDA (Linear Discriminant Analysis) classification, the absorptions 1203, 1238, 1284 and 1338 cm-1 were examined as spectral biomarkers, obtaining quite promising results. The use of a PCA-LDA prediction model on samples with moderate tumor degree further showed that the stroma chemical modifications are more indicative of malignancy compared to the epithelium. These preliminary findings have shown that micro-FTIR spectroscopy, focused on collagen signals, could become a promising tool for colon cancer diagnosis.

Comparison of Isotonic Activation of Cell Volume Regulation in Rat Peritoneal Mesothelial Cells and in Kidney Outer Medullary Collecting Duct Principal Cells.

In disease states, mesothelial cells are exposed to variable osmotic conditions, with high osmotic stress exerted by peritoneal dialysis (PD) fluids. They contain unphysiologically high concentrations of glucose and result in major peritoneal membrane transformation and PD function loss. The effects of isotonic entry of urea and myo-inositol in hypertonic (380 mOsm/kg) medium on the cell volume of primary cultures of rat peritoneal mesothelial cells and rat kidney outer medullary collecting duct (OMCD) principal cells were studied. In hypertonic medium, rat peritoneal mesothelial cells activated a different mechanism of cell volume regulation in the presence of isotonic urea (100 mM) in comparison to rat kidney OMCD principal cells. In kidney OMCD cells inflow of urea into the shrunken cell results in restoration of cell volume. In the shrunken peritoneal mesothelial cells, isotonic urea inflow caused a small volume increase and activated regulatory volume decrease (RVD). Isotonic myo-inositol activated RVD in hypertonic medium in both cell types. Isotonic application of both osmolytes caused a sharp increase of intracellular calcium both in peritoneal mesothelial cells and in kidney OMCD principal cells. In conclusion, peritoneal mesothelial cells exhibit RVD mechanisms when challenged with myo-inositol and urea under hyperosmolar isotonic switch from mannitol through involvement of calcium-dependent control. Myo-inositol effects were identical with the ones in OMCD principal cells whereas urea effects in OMCD principal cells led to no RVD induction.

Tight Junction ZO Proteins Maintain Tissue Fluidity, Ensuring Efficient Collective Cell Migration.

Tight junctions (TJs) are essential components of epithelial tissues connecting neighboring cells to provide protective barriers. While their general function to seal compartments is well understood, their role in collective cell migration is largely unexplored. Here, the importance of the TJ zonula occludens (ZO) proteins ZO1 and ZO2 for epithelial migration is investigated employing video microscopy in conjunction with velocimetry, segmentation, cell tracking, and atomic force microscopy/spectroscopy. The results indicate that ZO proteins are necessary for fast and coherent migration. In particular, ZO1 and 2 loss (dKD) induces actomyosin remodeling away from the central cortex towards the periphery of individual cells, resulting in altered viscoelastic properties. A tug-of-war emerges between two subpopulations of cells with distinct morphological and mechanical properties: 1) smaller and highly contractile cells with an outward bulging apical membrane, and 2) larger, flattened cells, which, due to tensile stress, display a higher proliferation rate. In response, the cell density increases, leading to crowding-induced jamming and more small cells over time. Co-cultures comprising wildtype and dKD cells migrate inefficiently due to phase separation based on differences in contractility rather than differential adhesion. This study shows that ZO proteins are necessary for efficient collective cell migration by maintaining tissue fluidity and controlling proliferation.

Co-culture with peritoneum mesothelial stem cells supports the in vitro growth of mouse ovarian follicles.

The important roles played by the ovarian microenvironment and cell interactions in folliculogenesis suggest promising approaches for in vivo growth of ovarian follicles using appropriate scaffolds containing suitable cell sources. In this study, we have investigated the growth of early preantral follicles in the presence of decellularized mesenteric peritoneal membrane (MPM), peritoneum mesothelial stem cells (PMSCs), and conditioned medium (CM) of PMSCs. MPM of mouse was first decellularized; PMSCs were isolated from MPM and cultured and their conditioned medium (CM) was collected. Mouse follicles were separated into four groups: (1) culture in base medium (control), (2) culture in decellularized MPM (DMPM), (3) co-culture with PMSCs (Co-PMSCs), and (4) culture in CM of PMSCs (CM-PMSCs). Qualitative and quantitative assessments were performed to evaluate intact mesenteric peritoneal membrane (IMPM) as well as decellularized ones. After culturing the ovarian follicles, follicular and oocyte diameter, viability, eccentric oocyte percentage, and estradiol hormone amounts were evaluated. Quantitative and qualitative evaluations confirmed removal of cells and retention of the essential fibers in MPM after the decellularization process. Follicular parameters showed that Co-PMSCs better support in vitro growth and development of ovarian follicles than the other groups. The eccentric rate and estradiol production were statistically higher for the Co-PMSCs group than for the CM-PMSCs and control groups. Although the culture of early preantral follicles on DMPM and CM-PMSCs could improve in vitro follicular growth, co-culture of follicles with PMSCs showed even greater improvements in terms of follicular growth and diameter.

Multi-scaled Monte Carlo calculation for radon-induced cellular damage in the bronchial airway epithelium.

Radon is a leading cause of lung cancer in indoor public and mining workers. Inhaled radon progeny releases alpha particles, which can damage cells in the airway epithelium. The extent and complexity of cellular damage vary depending on the alpha particle's kinetic energy and cell characteristics. We developed a framework to quantitate the cellular damage on the nanometer and micrometer scales at different intensities of exposure to radon progenies Po-218 and Po-214. Energy depositions along the tracks of alpha particles that were slowing down were simulated on a nanometer scale using the Monte Carlo code Geant4-DNA. The nano-scaled track histories in a 5 µm radius and 1 µm-thick cylindrical volume were integrated into the tracking scheme of alpha trajectories in a micron-scale bronchial epithelium segment in the user-written SNU-CDS program. Damage distribution in cellular DNA was estimated for six cell types in the epithelium. Deep-sited cell nuclei in the epithelium would have less chance of being hit, but DNA damage from a single hit would be more serious, because low-energy alpha particles of high LET would hit the nuclei. The greater damage in deep-sited nuclei was due to the 7.69 MeV alpha particles emitted from Po-214. From daily work under 1 WL of radon concentration, basal cells would respond with the highest portion of complex DSBs among the suspected progenitor cells in the most exposed regions of the lung epithelium.

Ber-EP4 staining in effusion cytology: A potential source of false positives.

The distinction between reactive mesothelium and carcinoma in serous effusions can be very difficult. Immunocytochemistry (ICC) is the most widely used tool to improve the diagnostic accuracy of body fluid cytology, with several ICC markers being proposed. Ber-EP4 antibody has shown high sensitivity and specificity rates for diagnosing metastatic carcinoma. In our department, we have detected Ber-EP4 positivity in mesothelium in some cytological specimens. We reviewed all articles on Ber-EP4 staining in effusion cytology, summarized current findings and analyzed the staining pattern of all cases expressing Ber-EP4. Some cases showing Ber-EP4 positivity in mesothelium have been reported, most of which showed only weak Ber-EP4 staining or staining of less than 50% of mesothelial cells. However, some cases may show strong positivity both in cytological and histological specimens. Clinicians and pathologists should be aware of this source of misdiagnosis, and ICC results in mesothelium should be always interpreted cautiously and correlated with clinical tests, other ICC markers and patient's previous history.

Epithelium of the human vocal fold as a vibrating tissue.

OBJECTIVES: The human adult vocal fold mucosa, especially, superficial layer of the lamina propria (Reinke's space) has attracted notice as an important vibrating structure. However, fine structures of the stratified squamous epithelium of the human adult vocal fold, which is another histological component of the mucosa, remain enigmatic. METHODS: Three normal human adult vocal folds and epiglottises and three newborn vocal folds were investigated. Observations using transmission electron microscopy and light microscopy including immunohistochemistry were performed. RESULTS: The most obvious feature of the epithelium of the human adult vocal folds was that the intercellular spaces between adjacent epithelial cells were large (984 ± 186 nm) compared with the stratified squamous epithelium of the human adult epiglottis and the human newborn vocal fold. Even though intercellular spaces between adjacent epithelial cells of the human adult vocal fold were large, desmosomes at the junctions of two adjacent epithelial cells made firm intercellular adhesion. Tonofilaments composed of the bundles of intermediate filaments anchored to the desmosomes. Desmosomes formed a continuous cytoskeletal network throughout the epithelial cells and epithelium of the human adult vocal fold. In addition, a great deal of E-cadherin (adhesive glycoprotein) was present between epithelial cells especially the lower half of the stratified squamous epithelium of the human adult vocal fold. CONCLUSIONS: From the functional morphological point of view, stratified squamous epithelium of the human adult vocal fold seems to form a structural framework of tensile strength with pliability suitable structure for vibration.

Mesopolysaccharides: The extracellular surface layer of visceral organs.

The mesothelium is a dynamic and specialized tissue layer that covers the somatic cavities (pleural, peritoneal, and pericardial) as well as the surface of the visceral organs such as the lung, heart, liver, bowel and tunica vaginalis testis. The potential therapeutic manipulation of visceral organs has been complicated by the carbohydrate surface layer-here, called the mesopolysaccharide (MPS)-that coats the outer layer of the mesothelium. The traditional understanding of MPS structure has relied upon fixation techniques known to degrade carbohydrates. The recent development of carbohydrate-preserving fixation for high resolution imaging techniques has provided an opportunity to re-examine the structure of both the MPS and the visceral mesothelium. In this report, we used high pressure freezing (HPF) as well as serial section transmission electron microscopy to redefine the structure of the MPS expressed on the murine lung, heart and liver surface. Tissue preserved by HPF and examined by transmission electron microscopy demonstrated a pleural MPS layer 13.01±1.1 um deep-a 100-fold increase in depth compared to previously reported data obtained with conventional fixation techniques. At the base of the MPS were microvilli 1.1±0.35 um long and 42±5 nm in diameter. Morphological evidence suggested that the MPS was anchored to the mesothelium by microvilli. In addition, membrane pits 97±17 nm in diameter were observed in the apical mesothelial membrane. The spatial proximity and surface density (29±4.5%) of the pits suggested an active process linked to the structural maintenance of the MPS. The striking magnitude and complex structure of the MPS indicates that it is an important consideration in studies of the visceral mesothelium.

Tumor induction in Drosophila imaginal epithelia triggers modulation of fat body lipid droplets.

Our understanding of cancer-specific metabolic changes is currently unclear. In recent years, the fruit fly Drosophila melanogaster with its powerful genetic tools has become an attractive model for studying both tumor autonomous and the systemic processes resulting from the tumor growth. Here we investigated the effect of tumorigenesis on the modulation of lipid droplets (LDs) in the larval fat bodies (mammalian equivalent of adipose tissue). We have overexpressed Notch signaling alone or in combination with the developmental regulator Myocyte enhancer factor 2 (Mef2) using wing-specific and eye-specific drivers, quantified the size of LDs in the fat body of the different tumor bearing larvae, and estimated the expression of genes associated with lipolysis and lipogenesis. We have found that hyperplastic and neoplastic tumor induced by overexpression of Notch and co-expression of Notch and Mef2 respectively triggers impaired lipid metabolism marked by increased size of fat body LDs. The impaired lipid metabolism in tumor carrying larvae is linked to the altered expression of genes that participate in lipolysis and lipogenesis. These findings reveal modulation of LDs as one of the host's specific response upon tumor initiation. This information could potentially uncover mechanisms for designing innovative approaches to modulate cancer growth.