Ultrastructure damage of oviduct telocytes in rat model of acute salpingitis

Acute salpingitis (AS) is an inflammatory disease which causes severe damage to a subset of classically described cells lining in oviduct wall and contributes to interstitial fibrosis and fertility problems. Telocytes (TCs), a newly discovered peculiar type of stromal cells, have been identified in many organs, including oviduct, with proposed multiple potential bio‐functions. However, with recent increasing reports regarding TCs alterations in disease‐affected tissues, there is still lack of evidence about TCs involvement in AS‐affected oviduct tissues and potential pathophysiological roles. We presently identified normal TCs by their characteristic ultrastructural features and immunophenotype. However, in AS‐affected oviduct tissues, TCs displayed multiple ultrastructural damage both in cellular body and prolongations, with obvious loss of TCs and development of tissue fibrosis. Furthermore, TCs lose their interstitial 3‐D network connected by homocellular or heterocellular junctions between TCs and adjacent cells. And especially, TCs connected to the activated immunocytes (mononuclear cells, eosinophils) and affected local immune state (repression or activation). Meanwhile, massive neutrophils infiltration and overproduced Inducible Nitric Oxide Synthase (iNOS), COX‐2, suggested mechanism of inflammatory‐induced TCs damage. Consequently, TCs damage might contribute to AS‐induced structural and reproductive functional abnormalities of oviduct, probably via: (i) substances, energy and functional insufficiency, presumably, e.g. TC‐specific genetic material profiles, ion channels, cytoskeletal elements, Tps dynamics, etc., (ii) impaired TCs‐mediated multicellular signalling, such as homeostasis/angiogenesis, tissue repair/regeneration, neurotransmission, (iii) derangement of 3‐D network and impaired mechanical support for TCs‐mediated multicellular signals within the stromal compartment, consequently induced interstitial fibrosis, (iv) involvement in local inflammatory process/ immunoregulation and possibly immune‐mediated early pregnancy failure.     

Variations of chromosomes 2 and 3 gene expression profiles among pulmonary telocytes,pneumocytes, airway cells,mesenchymal stem cells and lymphocytes

Telocytes (TCs) were identified as a distinct cellular type of the interstitial tissue and defined as cells with extremely long telopodes (Tps). Our previous data demonstrated patterns of mouse TC‐specific gene profiles on chromosome 1. The present study focuses on the identification of characters and patterns of TC‐specific or TC‐dominated gene expression profiles in chromosome 2 and 3, the network of principle genes and potential functional association. We compared gene expression profiles of pulmonary TCs, mesenchymal stem cells, fibroblasts, alveolar type II cells, airway basal cells, proximal airway cells, CD8⁺T cells from bronchial lymph nodes (T‐BL), and CD8⁺ T cells from lungs (T‐LL). We identified that 26 or 80 genes of TCs in chromosome 2 and 13 or 59 genes of TCs up‐ or down‐regulated in chromosome 3, as compared with other cells respectively. Obvious overexpression of Myl9 in chromosome 2 of TCs different from other cells, indicates that biological functions of TCs are mainly associated with tissue/organ injury and ageing, while down‐expression of Pltp implies that TCs may be associated with inhibition or reduction of inflammation in the lung. Dominant overexpression of Sh3glb1, Tm4sf1 or Csf1 in chromosome 3 of TCs is mainly associated with tumour promotion in lung cancer, while most down‐expression of Pde5 may be involved in the development of pulmonary fibrosis and other acute and chronic interstitial lung disease.     

Cardiac telocytes are double positive for CD34/PDGFR‐α

Telocytes (TCs) are a distinct type of interstitial cells, which are featured with a small cellular body and long and thin elongations called telopodes (Tps). TCs have been widely identified in lots of tissues and organs including heart. Double staining for CD34/PDGFR‐β (Platelet‐derived growth factor receptor β) or CD34/Vimentin is considered to be critical for TC phenotyping. It has recently been proposed that CD34/PDGFR‐α (Platelet‐derived growth factor receptor α) is actually a specific marker for TCs including cardiac TCs although the direct evidence is still lacking. Here, we showed that cardiac TCs were double positive for CD34/PDGFR‐α in primary culture. CD34/PDGFR‐α positive cells (putative cardiac TCs) also existed in mice ventricle and human cardiac valves including mitral valve, tricuspid valve and aortic valve. Over 87% of cells in a TC‐enriched culture of rat cardiac interstitial cells were positive for PDGFR‐α, while CD34/PDGFR‐α double positive cells accounted for 30.25% of the whole cell population. We show that cardiac TCs are double positive for CD34/PDGFR‐α. Better understanding of the immunocytochemical phenotypes of cardiac TCs might help using cardiac TCs as a novel source in cardiac repair.     

Differences in the expression of chromosome 1 genes between lung telocytes and other cells: mesenchymal stem cells,fibroblasts, alveolar type II cells,airway epithelial cells and lymphocytes

Telocytes (TCs) are a unique type of interstitial cells with specific, extremely long prolongations named telopodes (Tps). Our previous study showed that TCs are distinct from fibroblasts (Fbs) and mesenchymal stem cells (MSCs) as concerns gene expression and proteomics. The present study explores patterns of mouse TC‐specific gene profiles on chromosome 1. We investigated the network of main genes and the potential functional correlations. We compared gene expression profiles of mouse pulmonary TCs, MSCs, Fbs, alveolar type II cells (ATII), airway basal cells (ABCs), proximal airway cells (PACs), CD8⁺ T cells from bronchial lymph nodes (T‐BL) and CD8⁺ T cells from lungs (T‐LL). The functional and feature networks were identified and compared by bioinformatics tools. Our data showed that on TC chromosome 1, there are about 25% up‐regulated and 70% down‐regulated genes (more than onefold) as compared with the other cells respectively. Capn2, Fhl2 and Qsox1 were over‐expressed in TCs compared to the other cells, indicating that biological functions of TCs are mainly associated with morphogenesis and local tissue homoeostasis. TCs seem to have important roles in the prevention of tissue inflammation and fibrogenesis development in lung inflammatory diseases and as modulators of immune cell response. In conclusion, TCs are distinct from the other cell types.     

The Ultrastructure of Circulating Hemolymph Cells of the Marine Snail Cerithidea californica (Gastropoda: Prosobranchiata)

Two morphologically distinct blood cell-types, the granulocyte and hyalinocyte, are found in the hemolymph circulation of the marine prosobranch Cerithidea californica. Granulocytes, measuring 12.7 µ (9.0–15.0 µ) in diameter, possess well-defined ectoplasmic and endoplasmic regions of the cytoplasm, granules of moderate to heavy electron density, tubular rough endoplasmic reticulum (RER), short vesicles of smooth endoplasmic reticulum (SER), and a large cytoplasm to nucleus ratio. Two morphological variants of this cell-type are distinguished depending upon the presence or absence of dense granules or RER. Hyalinocytes, measuring 5.3 µ (4.0–8.0 µ) in diameter, are distinguished from gran ulocytes by possessing a smaller cytoplasm to nucleus ratio and a general lack of dense cytoplasmic granules and SER.     

Spatial organization of the caudate nucleus in dogs

The dog caudate nucleus was studied by the Nissl, Kluver-Barrera, and Golgi methods in the usual planes of section. A complex spatial organization of the caudate nucleus was established. Radial bundles of fibers form fibrous layers through which run blood vessels and in which large neurons (long-axon reticular and large short-axon smooth-dendritic) and also two types of small cells are located. In the mesh of the fibrous layers barrel-shaped concentrations of small (17.5 µm, about 2–4%, small short-axon smooth-dendritic) and medium-sized (25 µm, about 96–98%, long-axon densely branching spinous) cells can be observed. These concentrations have the appearance of two or three layers of elongated "barrels," their axis perpendicular to the surface of the internal capsule. The stria periventricularis of the caudate nucleus and certain others of its regions are less differentiated.     

Ultrastructure of dimorphic sperm and seminal receptacle in the hermaphrodites Barrimysia siphonosomae and Pseudopythina ochetostomae (Bivalvia, Galeommatoidea)

The intertidal Bivalvia Barrimysia siphonosomae (Montacutidae) and Pseudopythina ochetostomae (Kelliidae) live commensally with Siphonosoma cumanense (Sipuncula) and Ochetostoma erythrogrammon (Echiura), respectively. Both bivalves are hermaphrodites although males and females may occur. Paired, pouch-shaped seminal receptacles are located in the suprabranchial chamber near the genital opening of both species. The interior of the receptacles of sexually mature individuals contains numerous non-epithelial cells separated by narrow spaces that serve as a depot for sperm cells. Specimens of both species produce two sperm morphotypes. Euspermatozoa are oblong with elongate conical acrosomes, and a middlepiece consisting of about eight long mitochondria spirally arranged to form a sheath surrounding the basis of the flagellum. The paraspermatozoa are vermiform, about 4 µm broad and longer (up to 240 µm) in B. siphonosomae than in P. ochetostomae (ca 150 µm). The anterior, bullet-shaped, 4.5- or 3.0-µm-long acrosome is located above an elongate, 4- to 6-µm-long subcylindrical nucleus. Adjacent to the nucleus occurs a bundle of approximately 25 (B. siphonosomae) or ca 10 (P. ochetostomae) flagella. The cytoplasm of the sperm body contains spherical lipid droplets, glycogen deposits and numerous membrane-bound spindle- to rod-shaped electron-dense granules. It is presumed that both sperm types aggregate to form spermatozeugmata. The presence of a combination of almost identical and highly specialised euspermatozoa and paraspermatozoa in species of the two genera qualifies these structures as strong synapomorphies. Pseudopythina, as presently defined, is considered paraphyletic.     

Immunohistochemical characterization and functional identification of mammary gland telocytes in the self‐assembly of reconstituted breast cancer tissue in vitro

Telocyte (TC) as a special stromal cell exists in mammary gland and might play an important role in the balance of epithelium‐stroma of mammary gland. Considering that different types of breast interstitial cells influence the development and progression of breast cancer, TCs may have its distinct role in this process. We here studied the roles of TCs in the self‐assembly of reconstituted breast cancer tissue. We co‐cultured primary isolated TCs and other breast stromal cells with breast cancer EMT‐6 cells in collagen/Matrigel scaffolds to reconstitute breast cancer tissue in vitro. Using histology methods, we investigated the immunohistochemical characteristics and potential functions of TCs in reconstituted breast cancer tissue. TCs in primary mammary gland stromal cells with long and thin overlapping cytoplasmic processes, expressed c‐kit/CD117, CD34 and vimentin in reconstitute breast cancer tissue. The transmission electron microscopy showed that the telocyte‐like cells closely communicated with breast cancer cells as well as other stromal cells, and might serve as a bridge that directly linked the adjacent cells through membrane‐to‐membrane contact. Compared with cancer tissue sheets of EMT‐6 alone, PCNA proliferation index analysis and TUNEL assay showed that TCs and other breast stromal cells facilitated the formation of typical nest structure, promoted the proliferation of breast cancer cells, and inhibited their apoptosis. In conclusion, we successfully reconstituted breast cancer tissue in vitro, and it seems to be attractive that TCs had potential functions in self‐assembly of EMT‐6/stromal cells reconstituted breast cancer tissue.     

Structure of adhesive organ of the mountain-stream catfish, Pseudocheneis sulcatus (Teleostei: Sisoridae)

The structure and ultrastructure of the adhesive organ (AO) in the catfish, Pseudocheneis sulcatus (Sisoridae), an inhabitant of the sub‐Himalayan streams of India, is described. The surface of the AO is thrown into folds, the ridges of which bear curved spines. The AO epidermis consists of 10–12 tiers of filament‐rich cells, of which the outer tier cells project spines lined with a thick plasma membrane and bear bundles of tonofilaments (TF). Their cytoplasm contains TF and large mucus‐like granules, but no obvious organelles. A second tier of living cells with spines is present beneath the outer tier and seems to replace the latter when its spines are damaged or shed. The outer tier cells react positively with antibody to cytokeratin. Actin labelling is clearly absent from the outer tier, indicating that keratinization of the outer tier occurs in the absence of actin filaments. In the cells of the third to fifth tiers, the cytoplasm possesses abundant small mucous granules (0.1–0.3 µm), and fewer TF compared to the cytoplasm in the spines. The cells of the innermost tiers and the basal layer possess few TF bundles, but no mucous granules. The potential of AO filament cells to produce both mucous granules and keratin filaments is noteworthy. The observations provide evidence that specific regions of fish epidermis can actually undergo a true process of keratinization.     

Telocytes: novel interstitial cells present in the testis parenchyma of the Chinese soft‐shelled turtle Pelodiscus sinensis

Telocytes (TCs) are novel interstitial cells that have been found in various organs, but the existence of TCs in the testes has not yet been reported. The present ultrastructural and immunohistochemical study revealed the existence of TCs and differentiate these cells from the peritubular cells (Pc) in contact with the surrounding structures in the testes. Firstly, our results confirmed the existence of two cell types surrounding seminiferous tubules; these were Pc (smooth muscle like characteristics) and TCs (as an outer layer around Pc). Telocytes and their long thin prolongations called telopodes (Tps) were detected as alternations of thin segments (podomers) and thick bead‐like portions (podoms), the latter of which accommodate the mitochondria and vesicles. The spindle and irregularly shaped cell bodies were observed with small amounts of cytoplasm around them. In contrast, the processes of Pc contained abundant actin filaments with focal densities, irregular spine‐like outgrowths and nuclei that exhibited irregularities similar to those of smooth muscle cells. The TCs connected with each other via homocellular and heterocellular junctions with Pc, Leydig cells and blood vessels. The Tps of the vascular TCs had bands and shed more vesicles than the other TCs. Immunohistochemistry (CD34) revealed strong positive expression within the TC cell bodies and Tps. Our data confirmed the existence and the contact of TCs with their surroundings in the testes of the Chinese soft‐shelled turtle Pelodiscus sinensis, which may offer new insights for understanding the function of the testes and preventing and treating testicular disorders.     

TIP CELL GROWTH AND THE FREQUENCY AND DISTRIBUTION OF CELLULOSE MICROFIBRIL-SYNTHESIZING COMPLEXES IN THE PLASMA MEMBRANE OF APICAL SHOOT CELLS OF THE RED ALGA PORPHYRA YEZOENSIS1

The supramolecular organization of the plasma membrane of apical cells in shoot filaments of the marine red alga Porphyra yezoensis Ueda (conchocelis stage) was studied in replicas of rapidly frozen and fractured cells. The protoplasmic fracture (PF) face of the plasma membrane exhibited both randomly distributed single particles (with a mean diameter of 9.2 ± 0.2 nm) and distinct linear cellulose microfibril-synthesizing terminal complexes (TCs) consisting of two or three rows of linearly arranged particles (average diameter of TC particles 9.4 plusmn; 0.3 nm). The density of the single particles of the PF face of the plasma membrane was 3000 μm^?2, whereas that of the exoplasmic fracture face was 325 μm^?2. TCs were observed only on the PF face. The highest density of TCs was at the apex of the cell (mean density 23.0 plusmn; 7.4 TCs μm^?2 within 5 μm from the tip) and decreased rapidly from the apex to the more basal regions of the cell, dropping to near zero at 20 μm. The number of particle subunits of TCs per μm² of the plasma membrane also decreased from the tip to the basal regions following the same gradient as that of the TC density. The length of TCs increased gradually from the tip (mean length 46.0 plusmn; 1.4 nm in the area at 0–5 μm from the tip) to the cell base (mean length 60.0 plusmn; 7.0 μm in the area at 15–20 μm). In the very tip region (0–4 μm from the apex), randomly distributed TCs but no microfibril imprints were observed, while in the region 4–9 μm from the tip microfibril imprints and TCs, both randomly distributed, occurred. Many TCs involved in the synthesis of cellulose microfibrils were associated with the ends of microfibril imprints. Our results indicate that TCs are involved in the biosynthesis, assembly, and orientation of cellulose microfibrils and that the frequency and distribution of TCs reflect tip growth (polar growth) in the apical shoot cell of Porphyra yezoensis. Polar distribution of linear TCs as “cellulose synthase” complexes within the plasma membrane of a tip cell was recorded for the first time in plants.     

Uptake and intracytoplasmic storage of pigmented particles by human CD34+ stromal cells/telocytes: endocytic property of telocytes

We studied the phagocytic‐like capacity of human CD34+ stromal cells/telocytes (TCs). For this, we examined segments of the colon after injection of India ink to help surgeons localize lesions identified at endoscopy. Our results demonstrate that CD34+ TCs have endocytic properties (phagocytic‐like TCs: phTCs), with the capacity to uptake and store India ink particles. phTCs conserve the characteristics of TCs (long, thin, bipolar or multipolar, moniliform cytoplasmic processes/telopodes, with linear distribution of the pigment) and maintain their typical distribution. Likewise, they are easily distinguished from pigment‐loaded macrophages (CD68+ macrophages, with oval morphology and coarse granules of pigment clustered in their cytoplasm). A few c‐kit/CD117+ interstitial cells of Cajal also incorporate pigment and may conserve the phagocytic‐like property of their probable TC precursors. CD34+ stromal cells in other locations (skin and periodontal tissues) also have the phagocytic‐like capacity to uptake and store pigments (hemosiderin, some components of dental amalgam and melanin). This suggests a function of TCs in general, which may be related to the transfer of macromolecules in these cells. Our ultrastructural observation of melanin‐storing stromal cells with characteristics of TCs (telopodes with dichotomous branching pattern) favours this possibility. In conclusion, intestinal TCs have a phagocytic‐like property, a function that may be generalized to TCs in other locations. This function (the ability to internalize small particles), together with the capacity of these cells to release extracellular vesicles with macromolecules, could close the cellular bidirectional cooperative circle of informative exchange and intercellular interactions.     

Five new species of Eimeria Schneider, 1875 from the endangered Tibetan antelope Pantholops hodgsonii (Abel) (Artiodactyla: Bovidae: Caprinae) in the Hoh Xil Nature Reserve Area of Qinghai Province,China

We examined faeces of 76 endangered Tibetan antelopes Pantholops hodgsonii (Abel) in May 2017, from the Hoh Xil Nature Reserve, Qinghai Province, China, and found 62/76 (82%) discharging oöcysts representing five new species of Eimeria Schneider, 1875. Oöcysts of Eimeria pantholopensis n. sp., found in 54/76 (71%) chiru, are subspheroidal/ellipsoidal, 15–22 × 12–19 (18.6 × 16.1) µm, with a length/width (L/W) ratio of 1.0–1.3 (1.2); micropyle cap and 1–3 polar granules are present, but oöcyst residuum is absent. Sporocysts are ovoidal, 7–11 × 4–6 (9.2 × 5.3) µm, with a L/W ratio of 1.6–2.0 (1.7); Stieda body and sporocyst residuum of small, scattered granules are present; each sporozoite contains 2 refractile bodies. Oöcysts of Eimeria wudaoliangensis n. sp. found in 52/76 (68%) chiru, are pyriform, 21–29 × 17–21 (24.9 × 19.0) µm, with a L/W ratio of 1.1–1.5 (1.3); micropyle, micropyle cap and 1–4 polar granules are present, but oöcyst residuum is absent. Sporocysts are ovoidal, 9–13 × 5–8 (11.7 × 6.7) µm, with a L/W ratio of 1.4–2.7 (1.7); Stieda body and sporocyst residuum of disbursed granules are present; sporozoites have a single large refractile body. Oöcysts of Eimeria hodgsonii n. sp. found in 20/76 (26%) chiru, are elongate-ellipsoidal, 25–32 × 18–21 (28.9 × 19.8) µm, with a L/W ratio of 1.2–1.7 (1.5); micropyle, micropyle cap and 1–3 polar granules are present, but oöcyst residuum is absent. Sporocysts are ovoidal, 11–14 × 6–7 (12.3 × 6.8) µm, with a L/W ratio of 1.7–2.1 (1.8); Stieda body and sporocyst residuum as group of large granules lying along the interface between intertwined sporozoites are present; sporozoites have 2 refractile bodies. Oöcysts of Eimeria schalleri n. sp. found in 49/76 (64.5%) chiru, are ellipsoidal, 26–36 × 19–25 (30.4 × 23.2) µm, with a L/W ratio of 1.2–1.5 (1.3); micropyle with micropyle cap and polar granules appearing as many diffuse tiny bodies are present, but oöcyst residuum is absent. Sporocysts are ovoidal, 12–16 × 7–9 (14.2 × 7.8) µm, with a L/W ratio of 1.6–2.1 (1.8); Stieda body and sporocyst residuum are present, the latter as a group of small dispersed granules between intertwined sporozoites; sporozoites with 2 refractile bodies. Oöcysts of Eimeria sui n. sp. found in 4/76 (5%) chiru, are ovoidal, 32–38 × 26–30 (36.6 × 28.6) µm, with a L/W ratio of 1.0–1.4 (1.3); micropyle and micropyle cap and 1–3 polar granules are present, but oöcyst residuum is absent. Sporocysts are ovoidal, 15–18 × 8–10 (16.7 × 8.9) µm, with a L/W ratio of 1.7–2.1 (1.9); Stieda body and sporocyst residuum are present, the latter as a group of dispersed small granules; sporozoites with 2 refractile bodies. Five of 62 faecal samples in which oöcysts were detected (8%) had a single species infection, 13 of 62 (21%) had two species, 28 of 62 (45%) had three species and 16 of 62 (26%) had four species.

     

Cultivation‐independent characterization of ‘Candidatus Magnetobacterium bavaricum’ via ultrastructural,geochemical, ecological and metagenomic methods

‘Candidatus Magnetobacterium bavaricum’ is unusual among magnetotactic bacteria (MTB) in terms of cell size (8–10 µm long, 1.5–2 µm in diameter), cell architecture, magnetotactic behaviour and its distinct phylogenetic position in the deep‐branching Nitrospira phylum. In the present study, improved magnetic enrichment techniques permitted high‐resolution scanning electron microscopy and energy dispersive X‐ray analysis, which revealed the intracellular organization of the magnetosome chains. Sulfur globule accumulation in the cytoplasm point towards a sulfur‐oxidizing metabolism of ‘Candidatus M. bavaricum’. Detailed analysis of ‘Candidatus M. bavaricum’ microhabitats revealed more complex distribution patterns than previously reported, with cells predominantly found in low oxygen concentration. No correlation to other geochemical parameters could be observed. In addition, the analysis of a metagenomic fosmid library revealed a 34 kb genomic fragment, which contains 33 genes, among them the complete rRNA gene operon of ‘Candidatus M. bavaricum’ as well as a gene encoding a putative type IV RubisCO large subunit.     

Telocytes in human skin – are they involved in skin regeneration?

Telocytes (TCs), a particular interstitial cell type, have been recently described in a wide variety of mammalian organs ( www.telocytes.com ). The TCs are identified morphologically by a small cell body and extremely long (tens to hundreds of μm), thin prolongations (less than 100 nm in diameter, below the resolving power of light microscopy) called telopodes. Here, we demonstrated with electron microscopy and immunofluorescence that TCs were present in human dermis. In particular, TCs were found in the reticular dermis, around blood vessels, in the perifollicular sheath, outside the glassy membrane and surrounding sebaceous glands, arrector pili muscles and both the secretory and excretory portions of eccrine sweat glands. Immunofluorescence screening and laser scanning confocal microscopy showed two subpopulations of dermal TCs; one expressed c‐kit/CD117 and the other was positive for CD34. Both subpopulations were also positive for vimentin. The TCs were connected to each other by homocellular junctions, and they formed an interstitial 3D network. We also found TCs adjoined to stem cells in the bulge region of hair follicles. Moreover, TCs established atypical heterocellular junctions with stem cells (clusters of undifferentiated cells). Given the frequency of allergic skin pathologies, we would like to emphasize the finding that close, planar junctions were frequently observed between TCs and mast cells. In conclusion, based on TC distribution and intercellular connections, our results suggested that TCs might be involved in skin homeostasis, skin remodelling, skin regeneration and skin repair.     

Telocytes in mice bone marrow: electron microscope evidence

Telocytes (TCs) are a novel type of interstitial cell of whom presence has been recently documented in many tissues and organs. However, whether TCs exists in bone marrow is still not reported. This study aims to find out TCs in mice bone marrow by using scanning electron microscope (SEM) and transmission electron microscope (TEM). SEM images showed that in mice bone marrow most of TCs have small spherical cell body (usually 4–6 μm diameter) with thin long telopodes (Tps; usually one to three). The longest Tp observed was about 70 μm, with an uneven calibre. Direct intercellular contacts exist between TCs. TEM shows mitochondria within dilations of Tps. Also, by TEM, we show the close spatial relations of Tps with blood vessels. In conclusion, this study provides ultrastructural evidence regarding the existence of TCs in mice bone marrow, in situ.     

Estimation of whole‐body SAR from electromagnetic fields using personal exposure meters

In this article, personal electromagnetic field measurements are converted into whole‐body specific absorption rates for exposure of the general public. Whole‐body SAR values calculated from personal exposure meter data are compared for different human spheroid phantoms: the highest SAR values (at 950 MHz) are obtained for the 1‐year‐old child (99th percentile of 17.9 µW/kg for electric field strength of 0.36 V/m), followed by the 5‐year‐old child, 10‐year‐old child, average woman, and average man. For the 1‐year‐old child, whole‐body SAR values due to 9 different radiofrequency sources (FM, DAB, TETRA, TV, GSM900 DL, GSM1800 DL, DECT, UMTS DL, WiFi) are determined for 15 different scenarios. An SAR matrix for 15 different exposure scenarios and 9 sources is provided with the personal field exposure matrix. Highest 95th percentiles of the whole‐body SAR are equal to 7.9 µW/kg (0.36 V/m, GSM900 DL), 5.8 µW/kg (0.26 V/m, DAB/TV), and 7.1 µW/kg (0.41 V/m, DECT) for the 1‐year‐old child, with a maximal total whole‐body SAR of 11.5 µW/kg (0.48 V/m) due to all 9 sources. All values are below the basic restriction of 0.08 W/kg for the general public. 95th percentiles of whole‐body SAR per V/m are equal to 60.1, 87.9, and 42.7 µW/kg for GSM900, DAB/TV, and DECT sources, respectively. Functions of the SAR versus measured electric fields are provided for the different phantoms and frequencies, enabling epidemiological and dosimetric studies to make an analysis in combination with both electric field and actual whole‐body SAR. Bioelectromagnetics 31:286–295, 2010. © 2009 Wiley‐Liss, Inc.     

Characterization of a gastrointestinal tract microscale cell culture analog used to predict drug toxicity

The lining of the gastrointestinal (GI) tract is the largest surface exposed to the external environment in the human body. One of the main functions of the small intestine is absorption, and intestinal absorption is a route used by essential nutrients, chemicals, and pharmaceuticals to enter the systemic circulation. Understanding the effects of digestion on a drug or chemical, how compounds interact with and are absorbed through the small intestinal epithelium, and how these compounds affect the rest of the body is critical for toxicological evaluation. Our goal is to create physiologically realistic in vitro models of the human GI tract that provide rapid, inexpensive, and accurate predictions of the body's response to orally delivered drugs and chemicals. Our group has developed an in vitro microscale cell culture analog (µCCA) of the GI tract that includes digestion, a mucus layer, and physiologically realistic cell populations. The GI tract µCCA, coupled with a multi‐chamber silicon µCCA representing the systemic circulation, is described and challenged with acetaminophen. Proof of concept experiments showed that acetaminophen passes through and is metabolized by the in vitro intestinal epithelium and is further metabolized by liver cells, resulting in liver cell toxicity in a dose‐dependent manner. The µCCA response is also consistent with in vivo measurements in mice. The system should be broadly useful for studies on orally delivered drugs or ingestion of chemicals with potential toxicity. Biotechnol. Bioeng. 2009; 104: 193–205 © 2009 Wiley Periodicals, Inc.     

Blood platelets of the cheetah (Acinonyx jubatus)

The blood platelet count and platelet morphology of 22 adult cheetahs was investigated. The platelet counts of the animals displayed a normal distribution, with a mean count of 344×10⁹/l and a mean platelet volume of 11 fl. Morphological and ultrastructural features of the cheetah platelets revealed the typical platelet morphology of anuclear cells, with granules scattered throughout the cytoplasm. The characteristic surface canalicular system and microtubules were present. True cross‐sections of the platelets had a mean area of 2.146 µm², circumference of 6.805 µm, and mean minimum and maximum projections of 1.000 µm and 2.933 µm, respectively. Zoo Biol 23:263–271, 2004. © 2004 Wiley‐Liss, Inc.