Interstitial Environment Research Articles

Gracilideres mawatarii, a new genus and species of Franciscideridae (Allomalorhagida: Kinorhyncha) – A kinorhynch with thin body cuticle, adapted to the interstitial environment

A new genus and species of Kinorhyncha, Gracilideres mawatarii gen. et sp. nov. is described from coarse subtidal sand, west of Tanegashima Island, Japan. The genus and species is characterized by a cylindrical neck with sparsely arranged longitudinal crimps at surface; segments 1–10 each consisting of a single cylindrical cuticular plate; middorsal and ventromedial string-like glandular cells on segments 1–9; primary pectinate fringes with pectinate fringe teeth on segments 1–10; lateral accessory pores on segments 2–10; unpaired dorsal spines on segments 3–11 or 4–11, of which those on segments 3–9 are alternatingly laterally displaced left or right to paradorsal positions, and those on segments 10 and 11 in middorsal position; lateral accessory acicular spines on segment 5; lateroventral acicular spines on segments 4, 6–10; and tubes in lateroventral position on segments 2 and 5 and in ventrolateral position on segment 1. Together with the description of G. mawatarii gen. et sp. nov., emended diagnoses for the family Franciscideridae and the genus Franciscideres are provided. The introvert morphology of G. mawatarii gen. et sp. nov. is unique within Kinorhyncha, but showing some similarities to those of Franciscideres and Cateria, suggesting a close relationship between these three genera. The thin and flexible trunk cuticle in G. mawatarii gen. et sp. nov., Franciscideres, Neocentrophyidae, and some kentrorhagids would be related to the adaptation of interstitial environment. The thickening or thinning of cuticle has evolved independently at least twice in the kinorhynch lineages.

Acidic Environment Facilitates Mitochondrial Fragmentation Induced by APOL1 Renal‐Risk‐Variants in Kidney Cells

African Americans frequently carry G1 and G2 renal‐risk variants of the apolipoprotein L1 (APOL1) gene. Two copies of G1 and/or G2 confer 5–29 fold higher risk of chronic kidney disease (CKD); however, only 20% of those carrying risk‐genotype develop CKD. This indicates that an additional stressor may facilitate development of CKD in those carrying G1/G2 risk variants. Considering that a) G1/G2 variants elicit mitochondrial dysfunction in renal cells, b) APOL1 function is pH sensitive and c) renal interstitial pH is <7, we hypothesized that acidic interstitial environment in the kidney may amplify mitochondrial dysfunction induced by G1/G2 variants. To test the hypothesis, we incubated human embryonic kidney (HEK293) cells expressing APOL1 in pH=6.8 or 7.4; we estimated early mitochondrial dysfunction by measuring mitochondrial network morphology with confocal microscopy (Fig.1). HEK293 cells stably expressing APOL1 G0, G1, G2 or empty vector (EV) under doxycycline (Dox) control were exposed to Dox for 4, 6 or 8hr, while cultured in media pH=6.8 or pH=7.4. Confocal images were acquired at 1000 magnification in live cells kept in an environmentally‐controlled chamber at each time point; FIJI software was used to quantify relative mitochondrial length (ratio of “rods” vs. “network‐branches”). We also ascertained that a) APOL1 expression was comparable regardless of pH or APOL1 genotype for up to 8hr post Dox‐induction using real‐time PCR and b) cell viability was comparable under all conditions using lactate‐dehydrogenase‐based cytotoxicity assay. Without Dox, relative mitochondrial length was similar regardless of APOL1 genotype or pH. However, after 6hr of Dox‐induction in media pH=6.8, G2‐expressing cells had shorter mitochondrial length (6.54±0.40) vs. EV (7.65±0.72, p=0.02) or G0 cells (7.46±0.31, p=0.003), indicating early mitochondrial fragmentation. After 8hr of doxycycline‐induction in media pH=6.8, mitochondrial length in G1 (6.21±0.26) and G2 cells (6.46±0.34) was lower than EV (7.13±0.32, p=0.002 and p=0.008, respectively) and G0 cells (7.22±0.45, p=0.003 and p=0.01, respectively; Fig. 2). At media pH 7.4, mitochondrial length was comparable up to 8hr of Dox‐induction, regardless of APOL1 genotype. We concluded that acidic pH may facilitate early mitochondrial dysfunction induced by G1/G2 APOL1 risk‐variants in renal cells. We propose that an acidic interstitial pH may facilitate adverse effects of APOL1 renal‐risk variants in the kidney, but not other organs expressing APOL1.Support or Funding InformationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Non-hematopoietic Control of Peripheral Tissue T Cell Responses: Implications for Solid Tumors.

In response to pathological challenge, the host generates rapid, protective adaptive immune responses while simultaneously maintaining tolerance to self and limiting immune pathology. Peripheral tissues (e.g., skin, gut, lung) are simultaneously the first site of pathogen-encounter and also the location of effector function, and mounting evidence indicates that tissues act as scaffolds to facilitate initiation, maintenance, and resolution of local responses. Just as both effector and memory T cells must adapt to their new interstitial environment upon infiltration, tissues are also remodeled in the context of acute inflammation and disease. In this review, we present the biochemical and biophysical mechanisms by which non-hematopoietic stromal cells and extracellular matrix molecules collaborate to regulate T cell behavior in peripheral tissue. Finally, we discuss how tissue remodeling in the context of tumor microenvironments impairs T cell accumulation and function contributing to immune escape and tumor progression.

Roles of the TGF-β⁻VEGF-C Pathway in Fibrosis-Related Lymphangiogenesis.

Lymphatic vessels drain excess tissue fluids to maintain the interstitial environment. Lymphatic capillaries develop during the progression of tissue fibrosis in various clinical and pathological situations, such as chronic kidney disease, peritoneal injury during peritoneal dialysis, tissue inflammation, and tumor progression. The role of fibrosis-related lymphangiogenesis appears to vary based on organ specificity and etiology. Signaling via vascular endothelial growth factor (VEGF)-C, VEGF-D, and VEGF receptor (VEGFR)-3 is a central molecular mechanism for lymphangiogenesis. Transforming growth factor-β (TGF-β) is a key player in tissue fibrosis. TGF-β induces peritoneal fibrosis in association with peritoneal dialysis, and also induces peritoneal neoangiogenesis through interaction with VEGF-A. On the other hand, TGF-β has a direct inhibitory effect on lymphatic endothelial cell growth. We proposed a possible mechanism of the TGF-β–VEGF-C pathway in which TGF-β promotes VEGF-C production in tubular epithelial cells, macrophages, and mesothelial cells, leading to lymphangiogenesis in renal and peritoneal fibrosis. Connective tissue growth factor (CTGF) is also involved in fibrosis-associated renal lymphangiogenesis through interaction with VEGF-C, in part by mediating TGF-β signaling. Further clarification of the mechanism might lead to the development of new therapeutic strategies to treat fibrotic diseases.

Warming intensify CO2 flux and nutrient release from algal wrack subsidies on sandy beaches.

Algal wrack subsidies underpin most of the food web structure of exposed sandy beaches and are responsible of important biogeochemical processes that link marine and terrestrial ecosystems. The response in decomposition of algal wrack deposits to global warming has not been studied in ocean-exposed sandy beaches to date. With this aim, passive open top chambers (OTCs) were used to increase soil temperature within the range predicted by the IPCC for western Europe (between 0.5 and 1.5°C), following the hypothesis that the biogeochemical processing of macroalgal wrack subsidies would accelerate in response to temperature increase. The effect of temperature manipulation on three target substrates: fresh and aged macroalgae, and bare sand, was tested. Results indicated that a small warming (<0.5°C) affected the wrack decomposition process through traceable increases in soil respiration through CO2 flux, inorganic nutrients within the interstitial environment (N and P), sediment organic contents measured through the amount of proteins and microbial pool through the total soil DNA. The different responses of soil variables in the studied substrates indicated that the decomposition stage of stranded macroalgae influences the biogeochemical processing of organic matter in sandy beaches. Thus, CO2 fluxes, releases of organic and inorganic nutrients and microbial activity intensify in aged wrack deposits. Our results predict that expected global warming will increase the release of inorganic nutrients to the coastal ocean by 30% for the N (21Gg/year) and 5.9% for P (14 Gg/year); that increase for the flow of C to the atmosphere as CO2 was estimated in 8.2% (523Gg/year). This study confirms the key role of sandy beaches in recycling ocean-derived organic matter, highlighting their sensitivity to a changing scenario of global warming that predicts significant increases in temperature over the next few decades.

Distribution of PEG-coated hollow polyelectrolyte microcapsules after introduction into the circulatory system and muscles of zebrafish.

ABSTRACTThe use of polyelectrolyte multilayer microcapsules as carriers for fluorescent molecular probes is a prospective technique for monitoring the physiological characteristics of animal vasculature and interstitial environment in vivo. Polyelectrolyte microcapsules have many features that favor their use as implantable carriers of optical sensors, but little information is available on their interactions with complex living tissues, distribution or residence time following different routes of administration in the body of vertebrates. Using the common fish model, the zebrafish Danio rerio, we studied in vivo the distribution of non-biodegradable microcapsules covered with polyethylene glycol (PEG) over time in the adults and evaluated potential side effects of their delivery into the fish bloodstream and muscles. Fluorescent microcapsules administered into the bloodstream and interstitially (in concentrations that were sufficient for visualization and spectral signal recording) both showed negligible acute toxicity to the fishes during three weeks of observation. The distribution pattern of microcapsules delivered into the bloodstream was stable for at least one week, with microcapsules prevalent in capillaries-rich organs. However, after intramuscular injection, the phagocytosis of the microcapsules by immune cells was manifested, indicating considerable immunogenicity of the microcapsules despite PEG coverage. The long-term negative effects of chronic inflammation were also investigated in fish muscles by histological analysis.

Development of respirable rifampicin-loaded nano-lipomer composites by microemulsion-spray drying for pulmonary delivery

The purpose of this study was to develop respirable rifampicin (RIF) loaded nano-lipomer (lipid/polymer) composites for pulmonary delivery to increase the availability of drug at local site, and enhance the residence time of drug in the lungs and thereby improving the therapy. Rifampicin-loaded nano-lipid polymer (nano-lipomer) composites were prepared by a microemulsion-spray dry technique and were characterized for particle size, thermal stability, polymorphic transitions and chemical integrity. Furthermore, the lipomer were screened for their surface morphology and in vitro rifampicin release behavior in simulated lung fluid (artificial lysosomal fluid (ALF) at pH 4.5 and Gamble's solution at a pH of 7.4) represent different interstitial environment in the lung. The particle sizes of the lipomer were ranged between 382.5 ± 6.033 to 561.8 ± 4.965 nm with a narrow polydispersity index (0.315 ± 0.023 to 0.424 ± 0.033) and zeta potential (−32.5 ± 1.206 to −26.5 ± 1.211 mV). Rifampicin entrapment efficiency was between 61.25 ± 1.049 to 73.14 ± 1.048% and SEM images revealed well-separated, sphere-shaped and smooth surface lipomer. DSC and XRD analysis of lipomer corroborated that the formulations were in an amorphous state. New nano-lipomer formulated with different ratios of lipid and polymer exhibited a rapid dissolution by an initial burst release of RIF followed by a controlled release profile.

Distribuição e abundância da meiofauna da Reserva Biológica do Atol das Rocas, Atlântico sul, no nordeste brasileiro

A meiofuna caracteriza-se por um grupo de organismos de organizações corporais e complexidades estruturais que permitiram sua integração ao ambiente intersticial. A variabilidade temporal da meiofauna ocorre em pequenas, médias e longas escalas e esse estudo objetivou a descrição da meiofauna do Atol das Rocas, ao longo de um ano de amostragens, correspondendo ao período seco e chuvoso, em quatro piscinas internas do Atol, localizadas a sotavento e a barlavento. Foram realizadas duas expedições ao atol, em dezembro de 2011 (período de estiagem) e em maio de 2012 (período chuvoso), ambas com duração de 30 dias. Em cada piscina foram coletadas, através de mergulho livre, quatro amostras de meiofauna, formando um quadrado imaginário de aproximadamente 1m², e uma amostra de sedimento. As amostras de meiofauna foram coletadas utilizando um testemunho de PVC de 10 cm de comprimento e 2,5 cm de diâmetro e formol salino a 4% como fixador. A meiofauna do Atol das Rocas esteve presente com 13 táxons, que seguindo a ordem evolutiva dos grupos, são eles: Cnidária, Nematoda, Polychaeta, Oligochaeta, Tardigrada, Ostracoda, Náuplios, Copepoda, Tanaidacea, Acari, Aplacophora, Bivalve e Larvas de várias espécies. Os grupos Copepoda e Nematoda, representaram 41,72% e 30,67%, respectivamente, do total de organismos encontrados. No que se refere à frequência de ocorrência, os organismos foram classificados em grupos, com distribuição constante dominante: Copepoda, Nematoda, Oligochaeta, Ostracoda e Polychatea; com distribuição constante abundante: Larvas; com distribuição ocasional comum: Bivalve, Tanaidacea, e Tardigrada; e com distribuição ocasional raro: Aplacophora, Cnidaria e Náuplios. Ao analisar os dados utilizando o teste de média Tukey ao nível de 5% de probabilidade, observou-se que a interação dos fatores época e local de coleta, não foram significativos estatisticamente para a variável analisada densidade de meiofauna coletada. Porém, quando foram analisados os fatores separadamente, observou-se que para o fator local de coleta os dados foram estatisticamente significativos, onde o local Piscina Tartaruga, apresentou a maior densidade.

The Laterosensory Canal System in Epigean and Subterranean Ituglanis (Siluriformes: Trichomycteridae), With Comments About Troglomorphism and the Phylogeny of the Genus.

The laterosensory system is a mechanosensory modality involved in many aspects of fish biology and behavior. Laterosensory perception may be crucial for individual survival, especially in habitats where other sensory modalities are generally useless, such as the permanently aphotic subterranean environment. In the present study, we describe the laterosensory canal system of epigean and subterranean species of the genus Ituglanis (Siluriformes: Trichomycteridae). With seven independent colonizations of the subterranean environment in a limited geographical range coupled with a high diversity of epigean forms, the genus is an excellent model for the study of morphological specialization to hypogean life. The comparison between epigean and subterranean species reveals a trend toward reduction of the laterosensory canal system in the subterranean species, coupled with higher intraspecific variability and asymmetry. This trend is mirrored in other subterranean fishes and in species living in different confined spaces, like the interstitial environment. Therefore, we propose that the reduction of the laterosensory canal system should be regarded as a troglomorphic (= cave-related) character for subterranean fishes. We also comment about the patterns of the laterosensory canal system in trichomycterids and use the diversity of this system among species of Ituglanis to infer phylogenetic relationships within the genus. J. Morphol. 278:4-28, 2017. ©© 2016 Wiley Periodicals,Inc.

A new interstitial ostracod species of the genus Paracobanocythere from Vietnam, with mitochondrial CO1 sequence data of three Asian species.

This study is a first report of an interstitial ostracod from Southeast Asia. The ostracod species, Paracobanocythere vietnamensis sp. n., was found in the marine interstitial environment of Phu Quoc Island, Vietnam. Thus far, three species of this genus have been described. The morphology of the carapace as well as the appendages of this new species are quite similar to Paracobanocythere hawaiiensis and Paracobanocythere watanabei. However, we found that they could be easily distinguished according to the morphology of the male copulatory organ. Additionally, we estimated the evolutionary distances among these three species based on nucleotide and amino acid sequences of the mitochondrial CO1 gene. Similar morphologies of carapaces and appendages, and relatively small evolutionary distances according to CO1 between Paracobanocythere vietnamensis sp. n. and Paracobanocythere watanabei suggest that these two species are very closely related.

Detailed reconstruction of the nervous and muscular system of Lobatocerebridae with an evaluation of its annelid affinity.

BackgroundThe microscopic worm group Lobatocerebridae has been regarded a ‘problematicum’, with the systematic relationship being highly debated until a recent phylogenomic study placed them within annelids (Curr Biol 25: 2000-2006, 2015). To date, a morphological comparison with other spiralian taxa lacks detailed information on the nervous and muscular system, which is here presented for Lobatocerebrum riegeri n. sp. based on immunohistochemistry and confocal laser scanning microscopy, supported by TEM and live observations.ResultsThe musculature is organized as a grid of longitudinal muscles and transverse muscular ring complexes in the trunk. The rostrum is supplied by longitudinal muscles and only a few transverse muscles. The intraepidermal central nervous system consists of a big, multi-lobed brain, nine major nerve bundles extending anteriorly into the rostrum and two lateral and one median cord extending posteriorly to the anus, connected by five commissures. The glandular epidermis has at least three types of mucus secreting glands and one type of adhesive unicellular glands.ConclusionsNo exclusive “annelid characters” could be found in the neuromuscular system of Lobatocerebridae, except for perhaps the mid-ventral nerve. However, none of the observed structures disputes its position within this group. The neuromuscular and glandular system of L. riegeri n. sp. shows similarities to those of meiofaunal annelids such as Dinophilidae and Protodrilidae, yet likewise to Gnathostomulida and catenulid Platyhelminthes, all living in the restrictive interstitial environment among sand grains. It therefore suggests an extreme evolutionary plasticity of annelid nervous and muscular architecture, previously regarded as highly conservative organ systems throughout metazoan evolution.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0531-x) contains supplementary material, which is available to authorized users.

Historical biogeography of the genus Polycopissa (Ostracoda: Myodocopa: Cladocopina), with the description and DNA barcode of the second Indo-Pacific species from the Seto Inland Sea

A new cladocopid ostracod species, Polycopissa okadai n. sp., is described from the marine interstitial environment of the Seto Inland Sea, western Japan. This is the second representative of this genus identified from the Indo-Pacific region. A detailed morphological observation of the carapace and appendage was performed using a scanning electron microscope. In particular, the results showed that the morphology of the pore system on the outer surface of the carapace could be utilised for generic-level identification and for taxonomic classification of fossil species. In addition, the DNA barcode sequence of this new species was also determined, which was the first such determination within the suborder Cladocopina. Species belonging to Polycopissa Chavtur 1981 show a transoceanic distribution and have been reported from cryptic habitats such as interstitial waters or anchialine caves. The historical biogeography of Polycopissa is the subject of this study, based on previously suggested hypotheses. It is highly likely that the species of Polycopissa are a Tethyan relict and must have recently dispersed from an adjacent habitat to the current distribution area.

The hyporheic zone and its functions: revision and research status in Neotropical regions.

The hyporheic zone (HZ), as the connecting ecotone between surface- and groundwater, is functionally part of both fluvial and groundwater ecosystems. Its hydrological, chemical, biological and metabolic features are specific of this zone, not belonging truly neither to surface- nor to groundwater. Exchanges of water, nutrients, and organic matter occur in response to variations in discharge and bed topography and porosity. Dynamic gradients exist at all scales and vary temporally. Across all scales, the functional significance of the HZ relates to its activity and connection with the surface stream. The HZ is a relatively rich environment and almost all invertebrate groups have colonized this habitat. This fauna, so-called hyporheos, is composed of species typical from interstitial environment, and also of benthic epigean and phreatic species. The hyporheic microbiocenose consists in bacteria, archaea, protozoa and fungi. The HZ provides several ecosystem services, playing a pivotal role in mediating exchange processes, including both matter and energy, between surface and subterranean ecosystems, functioning as regulator of water flow, benthic invertebrates refuge and place of storage, source and transformation of organic matter. The hyporheic zone is one of the most threatened aquatic environments, being strongly influenced by human activities, and the least protected by legislation worldwide. Its maintenance and conservation is compelling in order to preserve the ecological interconnectivity among the three spatial dimensions of the aquatic environment. Although several researchers addressed the importance of the hyporheic zone early, and most contemporary stream ecosystem models explicitly include it, very little is known about the HZ of Neotropical regions. From a biological standpoint, hyporheos fauna in Neotropical regions are still largely underestimated. This review focuses on a brief presentation of the hyporheic zone and its functions and significance as an ecotone. We also highlighted the key aspects considering also the current status of research in Neotropical regions.

Atypical Features in Regenerating Tubules Point to a Risk for Implantation of Renal Stem/Progenitor Cells

Stem/progenitor cells are seen as a therapeutic option for repair of diseased renal parenchyma. However, actual data show that survival of implanted stem/progenitor cells is impeded by harmful interstitial environment. To learn about parameters for cell adaptation, renal stem/progenitor cells were mounted in a polyester (POSI-4) interstitium during perfusion culture. Controlled fluid environment was maintained by chemically defined CO 2 - independent culture media for 13 days. Cell biological features were then analyzed by immunohistochemistry, while structural details were investigated by advanced fixation of specimens for microscopy. When stem/progenitor cells are kept in Leibovitz's L-15 Medium or CO 2 Independent Medium, spatial development of numerous tubules is observed. Immunolabel for TROMA- III, cingulin and laminin ɣ1 depicts that a homogenous cell population is contained. Semithin sections of specimens fixed in traditional glutaraldehyde (GA) solution reflect an unobtrusive morphology. In contrast, fixation by GA solution including ruthenium red unveils in tubules a thickened basal lamina. Fixation by GA solution including tannic acid illustrates atypical development of a heterogeneous epithelium consisting of bright and dark cells. Thus, advanced fixation of specimens makes pathological features visible, when regeneration is investigated by renal stem/ progenitor cells. To what extent a comparable risk lurks behind an implantation, has to be elaborated.

Effects of elevated CO2 and temperature on an intertidal meiobenthic community

In the near future, the marine environment is likely to be subjected to simultaneous increases in temperature and decreased pH. The potential effects of these changes on intertidal, meiofaunal assemblages were investigated using a mesocosm experiment. Artificial Substrate Units containing meiofauna from the extreme low intertidal zone were exposed for 60days to eight experimental treatments (four replicates for each treatment) comprising four pH levels: 8.0 (ambient control), 7.7 & 7.3 (predicted changes associated with ocean acidification), and 6.7 (CO2 point-source leakage from geological storage), crossed with two temperatures: 12°C (ambient control) and 16°C (predicted). Community structure, measured using major meiofauna taxa was significantly affected by pH and temperature. Copepods and copepodites showed the greatest decline in abundance in response to low pH and elevated temperature. Nematodes increased in abundance in response to low pH and temperature rise, possibly caused by decreased predation and competition for food owing to the declining macrofauna density. Nematode species composition changed significantly between the different treatments, and was affected by both seawater acidification and warming. Estimated nematode species diversity, species evenness, and the maturity index, were substantially lower at 16°C, whereas trophic diversity was slightly higher at 16°C except at pH6.7. This study has demonstrated that the combination of elevated levels of CO2 and ocean warming may have substantial effects on structural and functional characteristics of meiofaunal and nematode communities, and that single stressor experiments are unlikely to encompass the complexity of abiotic and biotic interactions. At the same time, ecological interactions may lead to complex community responses to pH and temperature changes in the interstitial environment.

Population fluctuation and vertical distribution of meiofauna in the Red Sea interstitial environment

The composition and distribution of the benthic meiofauna assemblages of the Egyptian coasts along the Red Sea are described in relation to abiotic variables. Sediment samples were collected seasonally from three stations chosen along the Red Sea to observe the meiofaunal community structure, its temporal distribution and vertical fluctuation in relation to environmental conditions of the Red Sea marine ecosystem. The temperature, salinity, pH, dissolved oxygen, and redox potential were measured at the time of collection. The water content of the sediments, total organic matters and chlorophyll a values were determined, and sediment samples were subjected to granulometric analysis. A total of 10 meiofauna taxa were identified, with the meiofauna being primarily represented by nematodes (on annual average from 42% to 84%), harpacticoids, polycheates and ostracodes; and the meiofauna abundances ranging from 41 to 167ind./10cm2. The meiofaunal population density fluctuated seasonally with a peak of 192.52ind./10cm2 during summer at station II. The vertical zonation in the distribution of meiofaunal community was significantly correlated with interstitial water, chlorophyll a and total organic matter values. The present study indicates the existence of the well diversified meiofaunal group which can serve as food for higher trophic levels in the Red Sea interstitial environment.

Spermatogenesis, sperm cell morphology and accompanying secretions from two interstitial marine mites

The sperm cell morphology and spermatogenesis of Halacaroides antoniazziae Pepato Tiago and da Rocha 2011 and Acaromantis vespucioi Pepato and Tiago 2004 was investigated. Halacaroides sperm cells have a complete acrosomal complex, dense tubules crossing the cytoplasm and modified mitochondria. Mature sperm cells are surrounded by two kinds of secretions. Inside the ejaculatory duct, they lie upon a centre composed of a secretion structured as heaps of elongated bodies. Acaromantis spermatozoa are spindle shaped and lack an acrosomal complex. The plasmalemma is deeply folded; the cytoplasm is very reduced and devoid of organelles. A single kind of globular secretion was found. The sperm mass is surrounded by two layers of amorphous secretions. These species share a peripheral pattern of nuclear condensation during spermatogenesis, a possible apomorphy for most halacarids, and no special adaptation to the interstitial environment could be related to their sperm cell morphology.

Hybrid metabolite formation in the interstitial environment of a fungal co-culture system

Hybrid metabolite formation in the interstitial environment of a fungal co-culture system

The Effect of Congestive Heart Failure on Sensor Accuracy Among Hospitalized Patients with Type 2 Diabetes

Congestive heart failure (CHF) features disturbances in the interstitial environment that may affect the accuracy of subcutaneous continuous glucose monitoring (CGM). A pooled analysis of two studies of hospitalized patients with type 2 diabetes randomized to intravenous or subcutaneous insulin was conducted. One study enrolled patients with CHF exacerbation, whereas history of CHF was an exclusion criterion in the other. All patients wore a professional CGM device for at least 24 h. Intravenous insulin was administered according to the institution's nursing-run protocol (duration of 12 and 48 h in non-CHF and CHF protocols, respectively). Subcutaneous insulin was delivered similarly in both groups. Subjects with CHF (n=43) had higher admission glucose and hemoglobin A1c compared with non-CHF subjects (n=32), but the sensor glucose values were similar. Overall mean absolute relative difference (MARD) was similar between CHF and non-CHF subjects (0.11 vs. 0.08, respectively; P=0.12). MARD was higher in the 100-149 mg/dL (P=0.003) and >199 mg/dL (P = 0.02) strata among CHF subjects. Static glucose and continuous glucose error grid analyses favored the non-CHF group. In multivariable analyses, only glucose coefficient of variation and log sensor time were independent predictors of elevated overall MARD >0.10. After adjustment for other factors, only increasing log sensor time was a significant predictor of elevated MARD in the 100-149 mg/dL strata. Among hospitalized subjects with type 2 diabetes, CHF exacerbation is not associated with lower sensor accuracy after adjustment for other factors, but this requires confirmation over a wider glucose range.

Feasibility of 39-potassium MR imaging of a human brain at 9.4 Tesla

To demonstrate the feasibility of performing 39-potassium MR imaging of a human brain. 39-Potassium magnetic resonance imaging of a human brain was performed at 9.4 T using a flexible twisted projection imaging acquisition with a nominal isotropic spatial resolution of 10 mm in 40 min using a single-tuned birdcage radiofrequency coil. Co-registered sodium imaging with a nominal isotropic spatial resolution of 3.5 mm was performed on the same subject in 10 min. The 39-potassium flexible twisted projection imaging imaging had a signal-to-noise ratio of 5.2 in brain paranchyma. This qualitative imaging showed the expected features when compared to co-registered high- and low-resolution sodium imaging of the same subject. Potassium MR images may offer complementary information to that of sodium MR images by sampling the intracellular rather that interstitial environment. Quantification will require additional improvement in signal-to-noise ratio to produce clinically useful bioscales as are developing for sodium MR imaging.