126 research outputs found

    Carbon-13 Dynamic MRS and MRSI of Normal and Fasted Rat Liver with Hyperpolarized C-Pyruvate

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    BACKGROUND: The use of in vivo (13)C nuclear magnetic resonance spectroscopy in probing metabolic pathways to study normal metabolism and characterize disease physiology has been limited by its low sensitivity. However, recent technological advances have enabled greater than 50,000-fold enhancement of liquid-state polarization of metabolically active (13)C substrates, allowing for rapid assessment of (13)C metabolism in vivo. The present study applied hyperpolarized (13)C magnetic resonance spectroscopy to the investigation of liver metabolism, demonstrating for the first time the feasibility of applying this technology to detect differences in liver metabolic states. PROCEDURES: [1-(13)C]pyruvate was hyperpolarized with a dynamic nuclear polarization instrument and injected into normal and fasted rats. The uptake of pyruvate and its conversion to the metabolic products lactate and alanine were observed with slice-localized dynamic magnetic resonance spectroscopy and 3D magnetic resonance spectroscopic imaging (3D-MRSI). RESULTS: Significant differences in lactate to alanine ratio (P < 0.01) between normal and fasted rat liver slice dynamic spectra were observed. 3D-MRSI localized to the fasted livers demonstrated significantly decreased (13)C-alanine levels (P < 0.01) compared to normal. CONCLUSIONS: This study presents the initial demonstration of characterizing metabolic state differences in the liver with hyperpolarized (13)C spectroscopy and shows the ability to detect physiological perturbations in alanine aminotransferase activity, which is an encouraging result for future liver disease investigations with hyperpolarized magnetic resonance technology

    3D Bioprinted Human Skeletal Muscle Constructs for Muscle Function Restoration

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    A bioengineered skeletal muscle tissue as an alternative for autologous tissue flaps, which mimics the structural and functional characteristics of the native tissue, is needed for reconstructive surgery. Rapid progress in the cell-based tissue engineering principle has enabled in vitro creation of cellularized muscle-like constructs; however, the current fabrication methods are still limited to build a three-dimensional (3D) muscle construct with a highly viable, organized cellular structure with the potential for a future human trial. Here, we applied 3D bioprinting strategy to fabricate an implantable, bioengineered skeletal muscle tissue composed of human primary muscle progenitor cells (hMPCs). The bioprinted skeletal muscle tissue showed a highly organized multi-layered muscle bundle made by viable, densely packed, and aligned myofiber-like structures. Our in vivo study presented that the bioprinted muscle constructs reached 82% of functional recovery in a rodent model of tibialis anterior (TA) muscle defect at 8 weeks of post-implantation. In addition, histological and immunohistological examinations indicated that the bioprinted muscle constructs were well integrated with host vascular and neural networks. We demonstrated the potential of the use of the 3D bioprinted skeletal muscle with a spatially organized structure that can reconstruct the extensive muscle defects

    Thyroid and pituitary gland development from hatching through metamorphosis of a teleost flatfish, the Atlantic halibut

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    Fish larval development, not least the spectacular process of flatfish metamorphosis, appears to be under complex endocrine control, many aspects of which are still not fully elucidated. In order to obtain data on the functional development of two major endocrine glands, the pituitary and the thyroid, during flatfish metamorphosis, histology, immunohistochemistry and in situ hybridization techniques were applied on larvae of the Atlantic halibut (Hippoglossus hippoglossus), a large, marine flatfish species, from hatching through metamorphosis. The material was obtained from a commercial hatchery. Larval age is defined as day-degrees (D =accumulated daily temperature from hatching). Sporadic thyroid follicles are first detected in larvae at 142 D (27 days post-hatch), prior to the completion of yolk sack absorption. Both the number and activity of the follicles increase markedly after yolk sack absorption and continue to do so during subsequent development. The larval triiodothyronine (T3) and thyroxine (T4) content increases, subsequent to yolk absorption, and coincides with the proliferation of thyroid follicles. A second increase of both T3 and T4 occurs around the start of metamorphosis and the T3 content further increases at the metamorphic climax. Overall, the T3 content is lower than T4. The pituitary gland can first be distinguished as a separate organ at the yolk sack stage. During subsequent development, the gland becomes more elongated and differentiates into neurohypophysis (NH), pars distalis (PD) and pars intermedia (PI). The first sporadic endocrine pituitary cells are observed at the yolk sack stage, somatotrophs (growth hormone producing cells) and somatolactotrophs (somatolactin producing cells) are first observed at 121 D (23 days post-hatch), and lactotrophs (prolactin producing cells) at 134 D (25 days post-hatch). Scarce thyrotrophs are evident after detection of the first thyroid follicles (142 D ), but coincident with a phase in which follicle number and activity increase (260 D ). The somatotrophs are clustered in the medium ventral region of the PD, lactotrophs in the anterior part of the PD and somatolactotrophs are scattered in the mid and posterior region of the pituitary. At around 600 D , coinciding with the start of metamorphosis, somatolactotrophs are restricted to the interdigitating tissue of the NH. During larval development, the pituitary endocrine cells become more numerous. The present data on thyroid development support the notion that thyroid hormones may play a significant role in Atlantic halibut metamorphosis. The time of appearance and the subsequent proliferation of pituitary somatotrophs, lactotrophs, somatolactotrophs and thyrotrophs indicate at which stages of larval development and metamorphosis these endocrine cells may start to play active regulatory roles.This work has been carried out within the projects ‘‘Endocrine Control as a Determinant of Larval Quality in Fish Aquaculture’’ (CT-96-1422) and ‘‘Arrested development: The Molecular and Endocrine Basis of Flatfish Metamorphosis’’ (Q5RS-2002-01192), with financial support from the Commission of the European Communities. However, it does not necessarily reflect the Commission’s views and in no way anticipates its future policy in this area. This project was further supported by the Swedish Council for Agricultural and Forestry Research and Pluriannual funding to CCMAR by the Portuguese Science and Technology Council

    On the analysis of the contact angle for impacting droplets using a polynomial fitting approach

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    ractical considerations on the measurement of the dynamic contact angle and the spreading diameter of impacting droplets are discussed in this paper. The contact angle of a liquid is commonly obtained either by a polynomial or a linear fitting to the droplet profile around the triple phase point. Previous works have focused on quasi-static or sessile droplets, or in cases where inertia does not play a major role on the contact angle dynamics. Here, we study the effect of droplet shape, the order of the fitting polynomial, and the fitting domain, on the measurement of the contact angle on various stages following droplet impact where the contact line is moving. Our results, presented in terms of the optical resolution and the droplet size, show that a quadratic fitting provides the most consistent results for a range of various droplet shapes. As expected, our results show that contact angle values are less sensitive to the fitting conditions for the cases where the droplet can be approximated to a spherical cap. Our experimental conditions include impact events with liquid droplets of different sizes and viscosities on various substrates. In addition, validating past works, our results show that the maximum spreading diameter can be parameterised by the Weber number and the rapidly advancing contact angle

    Safety and efficacy assessment of standardized herbal formula PM012

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    <p>Abstract</p> <p>Background</p> <p>This study was conducted to evaluate the efficacy of the herbal formula PM012 on an Alzheimer's disease model, human presenilin 2 mutant transgenic mice (hPS2m), and also to evaluate the toxicity of PM012 in Sprague-Dawely rats after 4 or 26 weeks treatment with repeated oral administration.</p> <p>Methods</p> <p>Spatial learning and memory capacities of hPS2m transgenic mice were evaluated using the Morris Water Maze. Simultaneously, PM012 was repeatedly administered orally to male and female SD rats (15/sex/group) at doses of 0 (vehicle control), 500, 1,000 and 2,000 mg/kg/day for 4 or 26 weeks. To evaluate the recovery potential, 5 animals of each sex were assigned to vehicle control and 2,000 mg/kg/day groups during the 4-week recovery period.</p> <p>Results</p> <p>The results showed that PM012-treated hPS2m transgenic mice showed significantly reduced escape latency when compared with the hPS2m transgenic mice. The repeated oral administration of PM012 over 26 weeks in male and female rats induced an increase and increasing trend in thymus weight in the female treatment groups (main and recovery groups), but the change was judged to be toxicologically insignificant. In addition, the oral administration of the herbal medicine PM012 did not cause adverse effects as assessed by clinical signs, mortality, body weight, food and water consumption, ophthalmology, urinalysis, hematology, serum biochemistry, blood clotting time, organ weights and histopathology. The No Observed Adverse Effects Levels of PM012 was determined to be 2,000 mg/kg/day for both sexes, and the target organ was not identified.</p> <p>Conclusion</p> <p>These results suggest that PM012 has potential for use in the treatment of the Alzheimer's disease without serious adverse effects.</p

    CD8 Cells of Patients with Diffuse Cutaneous Leishmaniasis Display Functional Exhaustion: The Latter Is Reversed, In Vitro, by TLR2 Agonists

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    Leishmania mexicana (Lm) causes localized (LCL) and diffuse (DCL) cutaneous leishmaniasis. DCL patients have a poor cellular immune response leading to chronicity. It has been proposed that CD8 T lymphocytes (CD8) play a crucial role in infection clearance, although the role of CD8 cytotoxicity in disease control has not been elucidated. Lesions of DCL patients have been shown to harbor low numbers of CD8, as compared to patients with LCL, and leishmanicidal treatment restores CD8 numbers. The marked response of CD8 towards Leishmania parasites led us to analyze possible functional differences between CD8 from patients with LCL and DCL. We compared IFNγ production, antigen-specific proliferation, and cytotoxicity of CD8 purified from PBMC against autologous macrophages (MO) infected with Leishmania mexicana (MOi). Additionally, we analyzed tissue biopsies from both groups of patients for evidence of cytotoxicity associated with apoptotic cells in the lesions. We found that CD8 cell of DCL patients exhibited low cytotoxicity, low antigen-specific proliferation and low IFNγ production when stimulated with MOi, as compared to LCL patients. Additionally, DCL patients had significantly less TUNEL+ cells in their lesions. These characteristics are similar to cellular “exhaustion” described in chronic infections. We intended to restore the functional capacity of CD8 cells of DCL patients by preincubating them with TLR2 agonists: Lm lipophosphoglycan (LPG) or Pam3Cys. Cytotoxicity against MOi, antigen-specific proliferation and IFNγ production were restored with both stimuli, whereas PD-1 (a molecule associated with cellular exhaustion) expression, was reduced. Our work suggests that CD8 response is associated with control of Lm infection in LCL patients and that chronic infection in DCL patients leads to a state of CD8 functional exhaustion, which could facilitate disease spread. This is the first report that shows the presence of functionally exhausted CD8 T lymphocytes in DCL patients and, additionally, that pre-stimulation with TLR2 ligands can restore the effector mechanisms of CD8 T lymphocytes from DCL patients against Leishmania mexicana-infected macrophages

    Regular use of analgesics is a risk factor for renal cell carcinoma

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    Phenacetin-based analgesics have been linked to the development of renal pelvis cancer and renal cell carcinoma (RCC). The relationship between non-phenacetin types of analgesics and kidney cancer is less clear, although laboratory evidence suggests that these drugs possess carcinogenic potential. A population-based case–control study involving 1204 non-Asian RCC patients aged 25–74 and an equal number of sex-, age- and race-matched neighbourhood controls was conducted in Los Angeles, California, to investigate the relationship between sustained use of analgesics and risk of RCC according to major formulation categories. Detailed information on medical and medication histories, and other lifestyle factors was collected through in-person interviews. Regular use of analgesics was a significant risk factor for RCC in both men and women (odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.4–1.9 for both sexes combined). Risks were elevated across all four major classes of analgesics (aspirin, non-steroidal anti-inflammatory agents other than aspirin, acetaminophen and phenacetin). Within each class of analgesics, there was statistically significant increasing risk with increasing level of exposure. Although there was some minor variability by major class of formulation, in general individuals in the highest exposure categories exhibited approximately 2.5-fold increase in risk relative to non- or irregular users of analgesics. Subjects who took one regular-strength (i.e. 325 mg) aspirin a day or less for cardiovascular disease prevention were not at an increased risk of RCC (OR = 0.9, 95% CI = 0.6–1.4). © 1999 Cancer Research Campaig

    3D-Printed Stationary Phases with Ordered Morphology: State of the Art and Future Development in Liquid Chromatography Chromatographia

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    Stationary phases with precisely ordered morphology have the potential to drastically 9 improve the performance of chromatographic operations, both in the analytical and in the 10 preparative/industrial fields. The recent wave of additive manufacturing, aka 3D printing, 11 gives the unprecedented ability to fabricate such stationary phases and to experimentally 12 prove theoretical principles of ordered chromatographic beds. The manufacture of highly 13 efficient chromatographic columns is becoming a reality as 3D printers become more 14 affordable and accessible, and their resolution, speed and material flexibility continue to 15 grow. This brings fresh ideas to the design of chromatographic beds, moving away from 16 stereotypical “packed” beds with spherical particles to bespoke monolithic structures to suit 17 a range of specific applications. This review aims to cover the state of the art of ordered 18 beds for liquid chromatography applications, drawing analogies between the well-19 established pillar-array columns in two-dimensions to their three-dimensional counterparts. 20 The potential use of 3D printing to create entirely new column formats and cartridge 21 designs such as microchip columns will also be discussed. Finally, key opportunities and 22 challenges which remain in the field of 3D-printed chromatography are summarised, with 23 the hope that 3D printed chromatographic columns will soon become the standard
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