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Scientific Reports Jul 2019Imaging apoptosis could provide an early and specific means to monitor tumor responses to treatment. To date, despite numerous attempts to develop molecular imaging...
Imaging apoptosis could provide an early and specific means to monitor tumor responses to treatment. To date, despite numerous attempts to develop molecular imaging approaches, there is still no widely-accepted and reliable method for in vivo imaging of apoptosis. We hypothesized that the distinct cellular morphologic changes associated with treatment-induced apoptosis, such as cell shrinkage, cytoplasm condensation, and DNA fragmentation, can be detected by temporal diffusion spectroscopy imaging (TDSI). Cetuximab-induced apoptosis was assessed in vitro and in vivo with cetuximab-sensitive (DiFi) and insensitive (HCT-116) human colorectal cancer cell lines by TDSI. TDSI findings were complemented by flow cytometry and immunohistochemistry. Cell cycle analysis and flow cytometry detected apoptotic cell shrinkage in cetuximab-treated DiFi cells, and significant apoptosis was confirmed by histology. TDSI-derived parameters quantified key morphological changes including cell size decreases during apoptosis in responsive tumors that occurred earlier than gross tumor volume regression. TDSI provides a unique measurement of apoptosis by identifying cellular characteristics, particularly cell shrinkage. The method will assist in understanding the underlying biology of solid tumors and predict tumor response to therapies. TDSI is free of any exogenous agent or radiation, and hence is very suitable to be incorporated into clinical applications.
Topics: Algorithms; Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Disease Models, Animal; Female; Humans; Image Processing, Computer-Assisted; Immunohistochemistry; Magnetic Resonance Imaging; Mice; Models, Theoretical; Xenograft Model Antitumor Assays
PubMed: 31266982
DOI: 10.1038/s41598-019-45864-y -
Memorias Do Instituto Oswaldo Cruz Oct 2017Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important...
BACKGROUND
Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract.
OBJECTIVES
In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts.
METHODS
We performed structural and ultrastructural analyses using light microscopy, scanning electron microscopy and transmission electron microscopy.
FINDINGS
It was observed that iron depletion (i) interrupts the proliferation of T. vaginalis, (ii) induces morphological changes in typical multiplicative trophozoites to spherical non-proliferative, non-motile pseudocysts, and (iii) induces the arrest of cell division at different stages of the cell cycle; (iv) iron is the fundamental element for the maintenance of typical trophozoite morphology; (v) pseudocysts induced by iron depletion are viable and reversible forms; and, finally, (vi) we demonstrated that pseudocysts induced by iron depletion are able to interact with human epithelial cells maintaining their spherical forms.
MAIN CONCLUSIONS
Together, these data suggest that pseudocysts could be induced as a response to iron nutritional stress and could have a potential role in the transmission and infection of T. vaginalis.
Topics: Epithelial Cells; HeLa Cells; Humans; Iron Chelating Agents; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Time Factors; Trichomonas vaginalis
PubMed: 28953994
DOI: 10.1590/0074-02760170032 -
Stem Cell Reports May 2023Adult-born cells, arriving daily into the rodent olfactory bulb, either integrate into the neural circuitry or get eliminated. However, whether these two populations...
Adult-born cells, arriving daily into the rodent olfactory bulb, either integrate into the neural circuitry or get eliminated. However, whether these two populations differ in their morphological or functional properties remains unclear. Using longitudinal in vivo two-photon imaging, we monitored dendritic morphogenesis, odor-evoked responsiveness, ongoing Ca signaling, and survival/death of adult-born juxtaglomerular neurons (abJGNs). We found that the maturation of abJGNs is accompanied by a significant reduction in dendritic complexity, with surviving and subsequently eliminated cells showing similar degrees of dendritic remodeling. Surprisingly, ∼63% of eliminated abJGNs acquired odor responsiveness before death, with amplitudes and time courses of odor-evoked responses similar to those recorded in surviving cells. However, the subsequently eliminated cell population exhibited significantly higher ongoing Ca signals, with a difference visible even 10 days before death. Quantitative supervised machine learning analysis revealed a relationship between the abJGNs' activity and survival probability, with low neuronal activity being supportive for survival.
Topics: Olfactory Bulb; Neurons; Interneurons; Odorants; Signal Transduction
PubMed: 37116486
DOI: 10.1016/j.stemcr.2023.03.018 -
Proceedings of the National Academy of... Jan 2022Inspired by the intriguing adaptivity of natural life, such as squids and flowers, we propose a series of dynamic and responsive multifunctional devices based on...
Inspired by the intriguing adaptivity of natural life, such as squids and flowers, we propose a series of dynamic and responsive multifunctional devices based on multiscale structural design, which contain metal nanocoating layers overlaid with other micro-/nanoscale soft or rigid layers. Since the optical/photothermal properties of a metal nanocoating are thickness dependent, metal nanocoatings with different thicknesses were chosen to integrate with other structural design elements to achieve dynamic multistimuli responses. The resultant devices demonstrate 1) strain-regulated cracked and/or wrinkled topography with tunable light-scattering properties, 2) moisture/photothermal-responsive structural color coupled with wrinkled surface, and 3) mechanically controllable light-shielding properties attributed to the strain-dependent crack width of the nanocoating. These devices can adapt external stimuli, such as mechanical strain, moisture, light, and/or heat, into corresponding changes of optical signals, such as transparency, reflectance, and/or coloration. Therefore, these devices can be applied as multistimuli-responsive encryption devices, smart windows, moisture/photothermal-responsive dynamic optics, and smartphone app-assisted pressure-mapping sensors. All the devices exhibit high reversibility and rapid responsiveness. Thus, this hybrid system containing ultrathin metal nanocoatings holds a unique design flexibility and adaptivity and is promising for developing next-generation multifunctional devices with widespread application.
PubMed: 35042819
DOI: 10.1073/pnas.2118991119 -
Alcoholism, Clinical and Experimental... Jan 2021In a previous study using Jacobian mapping to evaluate the morphological effects on the brain of binge (4-day) intragastric ethanol (EtOH) on wild-type Wistar rats, we...
BACKGROUND
In a previous study using Jacobian mapping to evaluate the morphological effects on the brain of binge (4-day) intragastric ethanol (EtOH) on wild-type Wistar rats, we reported reversible thalamic shrinkage and lateral ventricular enlargement, but persistent superior and inferior colliculi shrinkage in response to binge EtOH treatment.
METHODS
Herein, we used similar voxel-based comparisons of Magnetic Resonance Images collected in EtOH-exposed relative to control animals to test the hypothesis that regardless of the intoxication protocol or the rat strain, the hippocampi, thalami, and colliculi would be affected.
RESULTS
Two experiments [binge (4-day) intragastric EtOH in Fisher 344 rats and chronic (1-month) vaporized EtOH in Wistar rats] showed similarly affected brain regions including retrosplenial and cingulate cortices, dorsal hippocampi, central and ventroposterior thalami, superior and inferior colliculi, periaqueductal gray, and corpus callosum. While most of these regions showed significant recovery, volumes of the colliculi and periaqueductal gray continued to show response to each proximal EtOH exposure but at diminished levels with repeated cycles.
CONCLUSIONS
Given the high metabolic rate of these enduringly affected regions, the current findings suggest that EtOH per se may affect cellular respiration leading to brain volume deficits. Further, responsivity greatly diminished likely reflecting neuroadaptation to repeated alcohol exposure. In summary, this unbiased, in vivo-based approach demonstrating convergent brain systems responsive to 2 EtOH exposure protocols in 2 rat strains highlights regions that warrant further investigation in both animal models of alcoholism and in humans with alcohol use disorder.
Topics: Animals; Binge Drinking; Brain; Central Nervous System Depressants; Ethanol; Female; Magnetic Resonance Imaging; Male; Rats, Inbred F344; Rats, Wistar; Recovery of Function; Rats
PubMed: 33119896
DOI: 10.1111/acer.14496 -
Journal of Colloid and Interface Science Sep 2023The soft interfacial template-assisted confined self-assembly of block copolymers (BCPs) guiding colloidal aggregates has been extensively investigated by interfacial...
The soft interfacial template-assisted confined self-assembly of block copolymers (BCPs) guiding colloidal aggregates has been extensively investigated by interfacial instability. Whether the macromolecular polymer architectonics possessed stimulus-responsive self-regulated structural controllability more readily implement the morphological diversity of colloidal aggregates. Herein, we in-situ constructed the alginate-modified β-cyclodextrin/azobenzene-functionalized alkyl chains (Alg-β-CD/AzoC12) system by supramolecular host-guest interfacial recognition-engineered strategy, in which possessed photo-stimulated responsive structural reconfigurability by modulating assembly/disassembly behaviors between CD and Azo at oil/water interface. The host-guest droplet interfaces acted as soft templates managing interfacial instability by synergistically integrating supra-amphiphilic host-guest polymers with cosurfactants, further constructing various soft supracolloidal aggregates, including soft nanoaggregates, microspheres with tunable degrees of surface roughness. Additionally, the stimuli-altering structural reconfigurability of supramolecular host-guest polymers was regulated by ultraviolet/visible irradiation, endowing soft aggregates with structural diversity. It's highly anticipated that the supramolecular host-guest interfacial recognition self-assembly establishes great bridge between supramolecular host-guest chemistry and colloid interface science.
PubMed: 37167908
DOI: 10.1016/j.jcis.2023.04.165 -
The Journal of Clinical Investigation Dec 1973Renal micropuncture observations in the rat suggest that the entire "distal tubule" (defined by the micropuncturist as that portion of the renal tubule extending between...
Renal micropuncture observations in the rat suggest that the entire "distal tubule" (defined by the micropuncturist as that portion of the renal tubule extending between the macula densa and its first junction with another (renal tubule) may be responsive to vasopressin. However, this portion of the renal tubule contains two segments that are morphologically dissimilar. The "early" distal tubule is lined by epithelium characteristic of the distal convoluted tubule, while the "late" distal tubule is lined by epithelium characteristic of the cortical collecting duct. Thus, the present study was initiated to identify the most proximal site of action of vasopressin in the distal renal tubule. A water diuresis was established in rats with hereditary hypothalamic diabetes insipidus. In one-half of the animals the diuresis was interupted by an i.v. infusion of exogenous vasopressin. Morphological preservation of the kidneys was initiated after induction of vasopressin-induced antidiuresis or during maximum water diuresis. Cell swelling and dilatation of intercellular spaces, morphological findings indicative of vasopressin responsiveness, were observed in the cortical collecting duct including the late segment of the distal tubule, a segment that has also been described by morphologists as the initial collecting tubule. Morphological evidence of vasopressin-responsiveness was not observed in the early distal tubule (distal convoluted tubule). Additional morphological studies in Wistar, Long-Evans, and Sprague-Dawley rats demonstrated a marked difference in the random availability of distal convoluted tubules versus initial collecting tubules potentially available for micropuncture just beneath the renal capsule. The results suggest that hypotonic tubular fluid entering the early distal tubule (distal convoluted tubule) remains hypotonic to plasma until it enters the late distal tubule (initial collecting tubule) and that vasopressin-induced osmotic equilibration is a function of the latter segment alone. The findings emphasize the importance of morphological characterization of those segments of the renal tubule that are subjected to physiological investigation.
Topics: Animals; Diuresis; Kidney Tubules; Kidney Tubules, Distal; Microscopy, Electron; Natriuresis; Osmolar Concentration; Rats; Vasopressins
PubMed: 4750443
DOI: 10.1172/JCI107509 -
Frontiers in Plant Science 2019Seeds have greatly contributed to the successful colonization of land by plants. Compared to spores, seeds carry nutrients, rely less on water for germination, provide a...
Seeds have greatly contributed to the successful colonization of land by plants. Compared to spores, seeds carry nutrients, rely less on water for germination, provide a higher degree of protection against biotic and abiotic stresses, and can disperse in different ways. Such advantages are, to a great extent, provided by the seed coat. The evolution of a multi-function seed-coat is inheritably linked to the evolution of tissue polarity, which allows the development of morphologically and functionally distinct domains. Here, we show that the endothelium, the innermost cell layer of the seed coat, displays distinct morphological features along the proximal-distal axis. Furthermore, we identified a TRANSPARENT TESTA transcriptional module that contributes to establishing endothelium polarity and responsiveness to fertilization. Finally, we characterized its downstream gene pathway by whole-genome transcriptional analyses. We speculate that such a regulatory module might have been responsible for the evolution of morphological diversity in seed shape, micropylar pore formation, and cuticle deposition.
PubMed: 32117351
DOI: 10.3389/fpls.2019.01801 -
Chemical & Pharmaceutical Bulletin 2019Bilayer membranes formed by phospholipids vary in their membrane states by undergoing phase transitions in response to various external environmental factors. Pressure... (Review)
Review
Bilayer membranes formed by phospholipids vary in their membrane states by undergoing phase transitions in response to various external environmental factors. Pressure is one of these important environmental factors, but there are very few studies on the effects of pressure on phospholipid bilayer membranes. It is possible to deepen our understanding of the membrane states of phospholipid bilayer membranes by combining information regarding temperature- and/or ligand-responsivity with that regarding pressure-responsivity. In this review, we thermodynamically characterize the bilayer phase transitions of three kinds of saturated glycerophospholipids, each with a different polar head group (phosphatidyl-ethanolamine (PE), -choline (PC) or -glycerol (PG)), and explain their various membrane states depending on temperature and pressure. Both temperature- and pressure-responsivity reveal inherent features of these bilayer membranes: the metastability of the gel phase for PE bilayer membranes, the polymorphism of the gel phases for PC bilayer membranes and morphological changes in bilayer aggregates for PG bilayer membranes.
Topics: Glycerophospholipids; Lipid Bilayers; Phase Transition; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylglycerols; Pressure; Temperature; Thermodynamics
PubMed: 30930432
DOI: 10.1248/cpb.c18-00954 -
Journal of Nuclear Medicine : Official... Mar 2002Morphologic and functional imaging studies have not always given concordant results about brain areas showing atrophic changes and reduced flow or metabolism in...
UNLABELLED
Morphologic and functional imaging studies have not always given concordant results about brain areas showing atrophic changes and reduced flow or metabolism in Alzheimer's disease (AD). The aim of this study was to determine the initial abnormality and the longitudinal changes in both morphologic and functional measurements for the same individuals with AD.
METHODS
We investigated 15 patients with mild AD and 25 age-matched healthy volunteers. The AD patients underwent both MRI and SPECT 3 times at intervals of approximately 1 y. The gray matter volume, as segmented from MRI, and the regional cerebral blood flow (rCBF), as measured by SPECT, of AD patients were compared with those of healthy volunteers using statistical parametric mapping, which is a voxel-based analysis in stereotactic space.
RESULTS
Considerable discordance between areas of regional atrophy and areas of decreased rCBF was observed. The medial temporal areas showed a faster and more extensive reduction of gray matter volume than of rCBF. In comparison with the value at the baseline study, rCBF in the posterior cingulate gyrus and precuneus and the associative parietal cortex was extensively decreased. In contrast, the extent of significant decrease in this area continued to be much narrower for gray matter volume than for rCBF, even in the follow-up studies. Frontal areas, including the anterior cingulate gyrus and the orbitofrontal areas, showed a progressive reduction in both rCBF and gray matter volume. The reduction in rCBF was in a more posterior part of the associative temporal cortex than was the reduction in gray matter volume.
CONCLUSION
These results indicate a distinct discordance between morphologic and functional changes in a longitudinal study of AD. Functional changes may be caused partly by remote effects from the morphologically involved areas with decreased connectivity and partly by a compensatory response by neuronal plasticity.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Brain; Cerebrovascular Circulation; Female; Humans; Longitudinal Studies; Magnetic Resonance Imaging; Male; Middle Aged; Tomography, Emission-Computed, Single-Photon
PubMed: 11884488
DOI: No ID Found