Oxygen fluxes were mapped at the growing apices and along mycelial hyphal segments of the ascomycete Neurospora crassa. High spatial resolution was obtained using micro-oxygen probes (2-3 microm tip diameters) and the self-referencing technique to maximize the sensitivity of oxygen flux measurements. As expected, oxygen influx was inhibited by cyanide, although oxygen influx (and hyphal growth) resumed with the induction of an alternate oxidase activity. Along hyphal segments, variations in oxygen influx were not correlated with location, near or far from septa, and varied over time along the same hyphal segment. Growing hyphae had a region of maximal oxygen influx greater than 10 microm behind the hyphal tip, the oxygen influx was correlated with hyphal growth rate. The region of maximal oxygen influx did not correspond with mitochondrial density, which is maximal (about 30% of hyphal volume) 5-10 microm behind the tip. Therefore, tip-localized mitochondria do not contribute to the respiratory requirements of the growing hypha. The tip-localized mitochondria may function in clearing calcium from the cytoplasm, although a decline in chlortetracycline fluorescence after cyanide inhibition could also be due to ATP-depletion due to inhibition of actively respiring mitochondria. Alternatively, the growing tip may be the site of mitochondrial biogenesis.
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http://dx.doi.org/10.1016/j.femsle.2004.01.050 | DOI Listing |
Chin J Integr Med
January 2025
Department of Ultrasound in Medicine, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
Objective: To evaluate the therapeutic effects of Kuanxiong Aerosol (KXA) on ischemic stroke with reperfusion and elucidate the underlying pharmacological mechanisms.
Methods: In vivo pharmacological effects on ischemic stroke with reperfusion was evaluated using the transient middle cerebral artery occlusion (t-MCAO) mice model. To evaluate short-term outcome, 30 mice were randomly divided into vehicle group (n=15) and KXA group (n=15).
Mar Drugs
November 2024
Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
Peritoneal dialysis (PD) serves as a home-based kidney replacement therapy with increasing utilization across the globe. However, long-term use of high-glucose-based PD solution incites repeated peritoneal injury and inevitable peritoneal fibrosis, thus compromising treatment efficacy and resulting in ultrafiltration failure eventually. In the present study, we utilized human mesothelial MeT-5A cells for the in vitro experiments and a PD mouse model for in vivo validation to study the pathophysiological mechanisms underneath PD-associated peritoneal fibrosis.
View Article and Find Full Text PDFACS Nano
December 2024
Department of Pharmacy, Nanjing Medical Center for Clinical Pharmacy, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China.
Neural stem cell (NSCs) transplantation is a promising therapeutic strategy for spinal cord injury (SCI), but its efficacy is greatly limited by the local inhibitory microenvironment. In this study, based on l-arginine (l-Arg)-loaded mesoporous hollow cerium oxide (AhCeO) nanospheres, we constructed an injectable composite hydrogel (AhCeO-Gel) with microenvironment modulation capability. AhCeO-Gel protected NSCs from oxidative damage by eliminating excess reactive oxygen species while continuously delivering Nitric Oxide to the lesion of SCI in a pathological microenvironment, the latter of which effectively promoted the neural differentiation of NSCs.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Faculty of Archaeology, Leiden University, Leiden 2300RA, The Netherlands.
The early populations that inhabited the Antilles were traditionally understood as highly mobile groups of hunters/fishers and gatherers. Although more recent data have demonstrated that some populations engaged in the production of domestic plants and cultivars, questions remain about other aspects of their lifeways, including whether the adoption of domesticates was accompanied by a decrease in residential mobility. The level of sedentism in a population is an instrumental variable to understand community social relations and complexity, adaptations, and lifeways.
View Article and Find Full Text PDFACS Omega
December 2024
Hunan Provincial Key Laboratory of Geochemical Processes and Resource Environmental Effects, Changsha, Hunan 410014, China.
The largest negative carbon-isotope excursion in geological history has been reported by several studies of the upper Doushantuo Formation of South China, which has been correlated to the middle Ediacaran-Shuram excursion (SE). Due to a scarcity of radiometric age constraints on the excursion in South China, however, global correlations and comparisons of this event remain a debate. Here, we present Re-Os and carbon isotope data on organic-rich sediments obtained from a drill-core sample in the Chengkou area, the northeastern margin of the Yangtze Platform, and South China.
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