Ectopic Bone in the Kidneys and Visceral Fat of Male Fischer-344 Rats

Ossified particles (OSP) are microscopic, bone-like fragments found in the circulatory system of rodents and humans. Although theorized to develop in the bone marrow, their origin and impact on physiological processes are unknown. Further, the fate of OSP has not been determined and may exit the circulatory system and enter organs and tissues. PURPOSE: We sought to detect the presence of ectopic bone in the kidneys and visceral fat of rodents. METHODS: Young (6-mon; n=10) and old (24-mon; n=10) male Fischer-344 rats were anesthetized with isoflurane (3% to oxygen balance) and euthanized by excising the heart. The right and left kidneys and a segment of visceral fat were dissected, weighed (g), fixed in 10% formalin for 3 days at 4°C, and stored in 70% EtOH at -20°C. Tissues were subsequently analyzed via micro-computed tomography (μCT 45; Scanco Medical, Inc. Switzerland) and scanned at 15 µm. The following data were analyzed using One-Way ANOVAs (SPSS v29) and reported as follows: body mass (g), right kidney mass (g), left kidney mass (g), visceral fat mass (g), bone volume in the right kidney (μm3), bone volume in the left kidney (μm3), bone volume in the visceral fat (μm3), bone volume relative to right kidney mass (μm3/g), bone volume relative to left kidney mass (μm3/g), and bone volume relative to visceral fat mass (μm3/g). A p value of 0.05 was set a priori. Data are presented as Mean ± Standard deviation. RESULTS: Body mass was higher (p\u3c0.05) in the old vs. young rats (400 ± 31g vs. 352 ± 27g, respectively). Right kidney mass (1.35 ± 0.20g vs. 1.09 ± 0.13g, respectively), left kidney mass (1.37 ± 0.20g vs. 1.11 ± 0.12g, respectively) and visceral fat mass (3.25 ± 0.26g vs. 1.89 ± 0.42g, respectively) were higher (p\u3c0.05) in old vs. young rats. Bone volume in the right kidney (0.65 ± 0.56 μm3 vs. 0.62 ± 0.43 μm3, respectively), left kidney (0.51 ± 0.59 μm3 vs. 0.96 ± 0.86μm3, respectively) and visceral fat (0.98 ± 0.59 μm3 vs. 2.43 ± 04.35 μm3, respectively) did not differ between young and old rats. Further, there were still no differences when bone volume was normalized to right kidney mass (young, 0.47 ± 0.36 μm3/g vs. old, 0.49 ± 0.27 μm3/g), left kidney mass (young, 0.41 ± 0.53 μm3/g vs. old, 0.79 ± 0.70 μm3/g) and visceral fat mass (young, 0.58 ± 0.48 μm3/g vs. old, 0.79. ± 1.48 μm3/g). CONCLUSION: Advancing age did not augment the volume of bone in the kidneys and visceral fat. Despite this, the presence of bone in organs and tissues may affect physiological processes and should be explored. Further, we suggest a potential link between circulating OSP and ectopic bone observed in the organs and tissue of these rodents

Valve disease in chronic venous disorders: a quantitative ultrastructural analysis by transmission electron microscopy and stereology

INTRODUCTION: The ultrastructure of venous valves and walls in chronic venous disease was investigated. METHODS: Consecutive patients were categorised into one of three groups (group A: patients with C1 venous disease in accordance with CEAP (Clinical severity, Etiology, Anatomy, Pathophysiology); group B: C2 and C3; group C: C4, C5 and C6). The terminal or preterminal valve and adjacent vessel wall was harvested from the great saphenous vein. Sections were examined with a transmission electron microscope. The volumes of elastin and of collagen per unit surface area of valve were assessed, as well as the surface endothelium of valve and vessel wall. RESULTS: The study population consisted of 17 patients. The elastin ratio was analysed by means of stereology. Mean values were: in group A, 0.45 μm3/m2; in group B, 0.67 μm3/m2; in group C, 0.97 μm3/m2. The ratio was similar for collagen (A, 15.7 μm3/m2; B, 26.8 μm3/m2; C, 30.1 μm3/m2). Surface analysis of the valve endothelium and the adjacent vessel wall endothelium showed a trend towards increasing damage with more severe disease. CONCLUSIONS: With progression of venous disease, the valve elastin content, assessed morphologically, seems to increase, and the endothelium of the venous valve and the vein wall tend to show more damage

Ectopic Bone in the Lungs and Spleen of Male Fisher-344 Rats

Previous experimental data demonstrated ossified particles (OSP, i.e., bone-like particles) in the circulation of rodents as well as human subjects. Their ability to circulate could ultimately permit access to vital tissues, potentially leading to ectopic bone formation. Although the fate of OSP is yet unclear, their entry into soft tissues and organs may initiate pathological processes. PURPOSE: We sought to determine the presence of bone in the soft organs. METHODS: Young (6-mon; n=10) and old (24-mon; n=10) male Fisher-344 rats were anesthetized (3% isoflurane to oxygen balance) and euthanized by removal of the heart. Body mass (g) was determined prior to dissecting the right and left lungs and spleen. The tissues were stored in 10% formalin for 3 days at 4°C and then in 70% EtOH at -20°C until analysis. They were subsequently scanned (55 kVp and 145 µA) at 15µm via micro-computed tomography (µCT 45; Scanco Medical, Inc. Switzerland). To determine bone volume within the tissues, the entire lungs and spleen were analyzed. One-Way ANOVAs were used to determine significant differences in body mass (g), right lung mass (g), left lung mass (g), spleen mass (g), bone volume in the right lung (µm3), bone volume in the left lung (µm3), bone volume in the spleen (µm3), bone volume relative to right lung mass (µm3/g), bone volume relative to left lung mass (µm3/g), and bone volume relative to spleen mass (µm3/g). A p value of 0.05 was set a priori. Data are presented as Means ± Standard Deviation. RESULTS: Body mass was higher (pp3 vs. 34.8± 21.6 μm3, respectively) and left (71.2 ± 54.7 μm3 vs. 21.0 ± 7.4 μm3, respectively) lungs were higher (p3 vs. 2.6 ± 4.2 μm3, respectively) did not differ between young and old rats. When normalized to right lung mass (young, 49.2 ± 32.5 μm3/g vs. old, 186.6 ± 117.8 μm3 /g) and left lung mass (young, 42.2 ± 17.5 μm3/g vs. old, 127.0 ± 92.2 μm3/g), bone volumes were higher (p3/g vs. old, 2.3. ± 5.5 μm3/g), no differences were observed. CONCLUSION: We speculate that the presence of bone in the soft organs (i.e., ectopic bone formation) is associated with OSP in the circulation. Ectopic bone formation was exacerbated in the right and left lungs with advancing age. The presence of bone in the soft organs may contribute to a diverse number of pathologies

Ultra-Sensitive Hot-Electron Nanobolometers for Terahertz Astrophysics

The background-limited spectral imaging of the early Universe requires spaceborne terahertz (THz) detectors with the sensitivity 2-3 orders of magnitude better than that of the state-of-the-art bolometers. To realize this sensitivity without sacrificing operating speed, novel detector designs should combine an ultrasmall heat capacity of a sensor with its unique thermal isolation. Quantum effects in thermal transport at nanoscale put strong limitations on the further improvement of traditional membrane-supported bolometers. Here we demonstrate an innovative approach by developing superconducting hot-electron nanobolometers in which the electrons are cooled only due to a weak electron-phonon interaction. At T<0.1K, the electron-phonon thermal conductance in these nanodevices becomes less than one percent of the quantum of thermal conductance. The hot-electron nanobolometers, sufficiently sensitive for registering single THz photons, are very promising for submillimeter astronomy and other applications based on quantum calorimetry and photon counting.Comment: 19 pages, 3 color figure

Variation in the trophic morphology of astigmatid mites common in UK beehives

The chelal moveable digit in Carpoglyphus lactis (Linnaeus), Glycyphagus domesticus (DeGeer), and Tyrophagus putrescentiae (Schrank) from UK beehives is described using quantitative measures within a 2D mechanical model. The location of maximum jerk on the profile of the chelal moveable digit indicates the end of the mastication surface, which in these mites is confirmed to be just before the theoretical cut-off point for a functioning chewing `machine`. All three species should be able to grasp yeasts, spores and mycelial hyphae in the hive. The moveable digit of C. lactis may be designed to enable pollenophagy. The mastication surface is 21.3 μm in C. lactis, 18.8 μm in G. domesticus, and 17.2 μm in T. putrescentiae. The wild-collected C. lactis shows the smallest chelal moveable digit tip velocity ratios (i.e., the lowest relative length of input to output moment arms). Glycyphagus domesticus has the most primitive geometry of its chela. The depth of the moveable digit matches the inferred resistive forces applied by the mite to food at that point. Condylar and moveable digit strengthening by sclerotisation is associated with eating tougher food. Effective chelal gape is 28.7 μm in C. lactis, 25.9 μm in G. domesticus and 24.8 μm in T. putrescentiae. Maximum food fragment size grabbed by the chela is estimated as 7786 μm3 in C. lactis, 5348 μm3 in G. domesticus and 4703 μm3 in T. putrescentiae. Morsel size pre-ingestion is estimated as 4031 μm3 in C. lactis, 5228 μm3 in G. domesticus and 4246 μm3 in T. putrescentiae. Under reasonable assumptions one of these mites might be able to excavate its own body volume equivalent in about one hour

Reversible Nuclear-Lipid-Droplet Morphology Induced by Oleic Acid: A Link to Cellular-Lipid Metabolism

Neutral lipidsÐinvolved in many cellular processesÐare stored as lipid droplets (LD), thosemainly cytosolic (cLD) along with a small nuclear population (nLD). nLD could be involved innuclear-lipid homeostasis serving as an endonuclear buffering system that would provide orincorporate lipids and proteins involved in signalling pathways as transcription factors andas enzymes of lipid metabolism and nuclear processes. Our aim was to determine if nLDconstituted a dynamic domain. Oleic-acid (OA) added to rat hepatocytes or HepG2 cells inculture produced cellular-phenotypic LD modifications: increases in TAG, CE, C, and PLcontent and in cLD and nLD numbers and sizes. LD increments were reversed on exclusionof OA and were prevented by inhibition of acyl-CoA synthetase (with Triacsin C) and thuslipid biosynthesis. Under all conditions, nLD corresponded to a small population (2±10%) oftotal cellular LD. The anabolism triggered by OA, involving morphologic and size changeswithin the cLD and nLD populations, was reversed by a net balance of catabolism, uponeliminating OA. These catabolic processes included lipolysis and the mobilization of hydrolyzedFA from the LD to cytosolic-oxidation sites. These results would imply that nLD areactively involved in nuclear processes that include lipids. In conclusion, nLD are a dynamicnuclear domain since they are modified by OA through a reversible mechanism in combinationwith cLD; this process involves acyl-CoA-synthetase activity; ongoing TAG, CE, and PLbiosynthesis. Thus, liver nLD and cLD are both dynamic cellular organelles.Fil: Lagrutta, Lucía Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Montero Villegas, Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Layerenza, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Sisti, Martin Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Garcia, Margarita Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Ves Losada, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin

Antagonistic and synergistic responses to solar ultraviolet radiation and increased temperature of phytoplankton from cenotes (sink holes) of the Yucatán Peninsula, México

Cenotes (sink holes) are karstic formations characteristic of the Yucatán Peninsula and are the main source of fresh water in the region. Because of their tropical location, they receive high levels of solar radiation and are exposed to high temperatures. However, the effect of these global-change-related variables on phytoplankton in cenotes is unknown. We carried out experiments with phytoplankton communities collected from 2 cenotes differing in their penetration of solar radiation (Leona Vicario [LV]: turbid, Las Mojarras [LM]: clear) to assess the combined effect of solar ultraviolet radiation (UVR; 280–400 nm) and increased temperature on their photosystem (PS) II photochemistry. We exposed samples in microcosms to solar radiation (with and without UVR) and 2 temperatures (ambient = 25°C and increased by 3°C) and analyzed photochemical performance over daily cycles. A significant antagonistic interaction between UVR and temperature in LV caused a combined inhibition of the effective photochemical quantum yield (ΦPSII) that was smaller (63%) than the sum of the 2 individual effects of UVR and temperature (116%). In contrast, a significant synergistic interaction between UVR and temperature in LM caused the combined inhibition of ΦPSII (172%) to be higher than the sum of the individual effects of the 2 variables (134%). Differences in the size distribution and taxonomic composition of the phytoplankton communities, with smaller cells in LV than in LM, seem to account for much of the variability in responses to UVR and increased temperature between the 2 communities. Our results suggest that phytoplankton communities from clear cenotes will be more affected by the combined effects of solar UVR and increased temperature that those from turbid cenotes.Fil: Villafañe, Virginia Estela. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guendulain García, Sergio D.. Universidad Nacional Autónoma de México; MéxicoFil: Valadez, Francisco. Universidad Juárez Autónoma de Tabasco; México. Centro de Investigación Científica de Yucatán; MéxicoFil: Rosiles González, Gabriela. Centro de Investigación Científica de Yucatán; MéxicoFil: Helbling, Eduardo Walter. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Banaszak, Anastazia T.. Universidad Nacional Autónoma de México; Méxic