High Density Of Type Research Articles

Agaricus blazei Murill extract-loaded alginate/poly (vinyl alcohol)-based microgels as potential wound dressings

The development of new biomaterials based on natural products for wound treatment is a frequent research topic in recent years. In this study, the hydroalcoholic extract from Agaricus blazei Murill (EAb) was incorporated in microgels based on poly (vinyl alcohol) (PVA) and sodium alginate (SA). Microgels were characterized according to their physicochemical and morphological properties. An in vivo wound healing assay was performed and histomorphometric parameters and oxidative stress were studied. The physicochemical characterizations showed the occurrence of intermolecular interactions between both polymers and this natural product, suggesting a potential physical cross-linking. The microgels presented sol-gel transition (G’ > G’’) at low frequencies, porosity degree around 40 % and significant ability to scavenge the DPPH radical. Morphological characterization evidenced pores on the micrometric scale, where EAb granules (0.3–0.6 µm) are trapped. On the 14th day, mice treated with EAb-loaded microgels presented wound contraction > 99 %, as well as greater epidermis and dermis thickness, higher density of type I collagen and significant reduction in oxidative stress. Our results showed that EAb-loaded microgels, especially the M0.5 formulation, are a promising multifunctional biomaterial for wound dressing applications.

Cannabinoid Receptor Type 1 in Parkinson's Disease: A Positron Emission Tomography Study with [18 F]FMPEP-d2.

ABSTRACTBackgroundThe endocannabinoid system is a widespread neuromodulatory system affecting several biological functions and processes. High densities of type 1 cannabinoid (CB1) receptors and endocannabinoids are found in basal ganglia, which makes them an interesting target group for drug development in basal ganglia disorders such as Parkinson's disease (PD).ObjectiveThe aim of this study was to investigate CB1 receptors in PD with [18F]FMPEP‐d 2 positron emission tomography (PET) and the effect of dopaminergic medication on the [18F]FMPEP‐d 2 binding.MethodsThe data consisted of 16 subjects with PD and 10 healthy control subjects (HCs). All participants underwent a [18F]FMPEP‐d 2 high‐resolution research tomograph PET examination for the quantitative assessment of cerebral binding to CB1 receptors. To investigate the effect of dopaminergic medication on the [18F]FMPEP‐d 2 binding, 15 subjects with PD underwent [18F]FMPEP‐d 2 PET twice, both on and off antiparkinsonian medication.Results[18F]FMPEP‐d 2 distribution volume was significantly lower in the off scan compared with the on scan in basal ganglia, thalamus, hippocampus, and amygdala (P < 0.05). Distribution volume was lower in subjects with PD off than in HCs globally (P < 0.05), but not higher than in HCs in any brain region.ConclusionsSubjects with PD have lower CB1 receptor availability compared with HCs. PD medication increases CB1 receptor toward normal levels. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Two types of somatic spines provide sites for intercellular signaling during calyx of Held growth and maturation.

Dendritic spines have been described in developing and mature systems, but similar extensions from cell bodies are less studied. We utilized electron microscopy image volumes, uniquely collected across a range of early postnatal and month-old mice, to characterize and describe two types of somatic processes that extended into and under the developing calyx of Held (CH), which we named type 1 and type 2 spines. Type 1 spines occurred singly, were mostly vermiform in shape, and formed regularly spaced indentations into the CH. Type 1 spines appeared in concert with the earliest expansion of the CH by P3, peaked at P6 and returned to low density at P30. Type 2 spines were intertwined into a secondary structure called a spine mat, which has not previously been described in the CNS, and were more complex geometrically. Type 2 spines formed after the CH crossed a size threshold, reached maximum density at P9, and were absent from most CHs at P30. Both spine types, but a higher density of type 1 spines, were sites for synapse formation. Spine mats brought pre- and postsynaptic neurons and glial cells into contact, and were captured in stages of partial detachment and engulfment by the presynaptic terminal, suggesting trans-endocytosis as a mode of removal ahead of maturity. In conglomerate, these observations reveal somatic spines to be sites for chemical neurotransmission and chemical sampling among synaptic partners and glia as tissue structure transforms into mature neural circuits.

Acute Muscle Fatigue In Men And Women Following Upper-limb Low-intensity Blood-flow Restricted Exercise

Low intensity blood flow restricted exercise (LIBFRE) elicits acute changes in torque output and muscle activation. The magnitude of these changes affect the chronic adaptions to this type of training. Despite its widespread use by men and women, it is not known whether the acute impact of LIBFRE follows a sexually dimorphic pattern. This is important because, when compared to men, women have muscle fibers of smaller diameter, higher density of type I muscle fibers, higher muscle capillarization and heightened muscle perfusion. All these factors likely influence blood flow, as well as acute muscle fatigue, during LIBFRE. PURPOSE: To explore whether muscle fatigue post-acute LIBFRE and high intensity resistance (HI) training follows a sexually dimorphic pattern. METHODS 62 healthy young persons (31 men: 21.7 ± 2.3; 31 women: 22.0 ± 2.0 yrs) were included in this study. One-repetition maximum (1RM) was determined in each participant before training. Participants completed 4 sets of unilateral biceps curl with (30+15+15+15 reps) and without BFR (10+10+10+10 reps). HI was performed at 75% 1RM and LIBFR at 20% 1RM with BFR (60% of arterial occlusion pressure). Maximum voluntary contraction (MVC) was measured at pre- and post-training time points. Muscle fatigue was quantified as the percent difference between pre- and post- training MVC. RESULTS: Both HI and LIBFR training protocols induced significant muscle fatigue in men and women from pre- to post-training (p<0.05). HI was more fatiguing than LIBFRE in both sexes (HI: ~ 35 vs. LIBFRE: ~ 25%, p<0.05). These results were sustained even after controlling for the differences in volume load between protocols. As importantly, the magnitude of torque decrement was similar between men and women after HI and LIBFR training (p>0.05). CONCLUSIONS: Performing upper-limb LIBFRE, using a multiple-set training protocol, is less fatiguing than HI resistance exercise in both men and women. Additionally, this effect is independent of differences in volume load between exercise protocols. Torque decrements in response to LIBFR and HI do not follow a sexually dimorphic pattern, providing evidence that there is no need to establish different guidelines for men and women when prescribing upper-limb LIBFR exercise. Supported by the Portuguese Science Foundation PTDC/ DTP-DES/5714/2014.

Label-free photoacoustic microscopy for in-vivo tendon imaging using a fiber-based pulse laser

Tendons are tough, flexible, and ubiquitous tissues that connect muscle to bone. Tendon injuries are a common musculoskeletal injury, which affect 7% of all patients and are involved in up to 50% of sports-related injuries in the United States. Various imaging modalities are used to evaluate tendons, and both magnetic resonance imaging and sonography are used clinically to evaluate tendons with non-invasive and non-ionizing radiation. However, these modalities cannot provide 3-dimensional (3D) structural images and are limited by angle dependency. In addition, anisotropy is an artifact that is unique to the musculoskeletal system. Thus, great care should be taken during tendon imaging. The present study evaluated a functional photoacoustic microscopy system for in-vivo tendon imaging without labeling. Tendons have a higher density of type 1 collagen in a cross-linked triple-helical formation (65–80% dry-weight collagen and 1–2% elastin in a proteoglycan-water matrix) than other tissues, which provides clear endogenous absorption contrast in the near-infrared spectrum. Therefore, photoacoustic imaging with a high sensitivity to absorption contrast is a powerful tool for label-free imaging of tendons. A pulsed near-infrared fiber-based laser with a centered wavelength of 780 nm was used for the imaging, and this system successfully provided a 3D image of mouse tendons with a wide field of view (5 × 5 mm2).

Synapsid Burrows and Associated Trace Fossils in the Lower Jurassic Navajo Sandstone, Southeastern Utah, U.S.A., Indicates a Diverse Community Living in a Wet Desert Ecosystem

Abstract Enigmatic structures in the Lower Jurassic Navajo Sandstone near Moab, Utah, occur at three localities below carbonate beds that record interdune lake deposits. These structures are interpreted as mammal and therapsid burrows based on their architectural and surficial burrow morphologies: Type I (large diameter) and Type II (mega diameter) burrows. Type I burrows include sinuous tunnels, Y- and T-branched tunnels, sinuous ramps, and chambers, and weather into mounds averaging 33 m × 22 m and extend ~ 1m above the surface. Type I burrows are dorsoventrally flattened, in cross section averaging 9.3 cm wide and 4.2 cm high, and are sand filled and structureless. Type I burrows mostly have smooth walls, though some have scalloped walls. Type II burrows are simple, inclined tunnels ~ 35 cm wide and ~ 20 cm high, and exhibit well-preserved bilobate morphology along the underside of the tunnel. The walls preserve a series of 3 or 4 thin (~ 4–8 mm), inclined scratch marks from the upper part of the wall and along the floor. The great complexity and high density of Type I burrow systems is best explained by multiple individuals living together in social groups. These burrows are more complex than Early Triassic therapsid burrows from South Africa and are most similar to burrows of extant social (e.g., voles) and eusocial mammals (e.g., naked mole rats). Type II burrows were likely constructed by therapsids, based on burrow size and comparison to Permian and Triassic therapsid burrows from South Africa and Antarctica.

Role of leaf glandular trichomes of melon plants in deterrence of Aphis gossypii Glover

External characteristics of the leaf epidermis and their effects on behaviour of Aphis gossypii Glover were evaluated in two Cucumis melo L. genotypes, 'Bola de Oro' (aphid susceptible) and TGR-1551 (aphid resistant) in order to explore their role in the early rejection of TGR-1551 by this aphid. No differential effects of epicuticular waxes on aphid behaviour were observed. The type, distribution and number of trichomes on melon leaves were also studied. Pubescence in melon, measured as the number of non-glandular trichomes per cm(2), was not sufficient to prevent aphid settling. However, there was a high density of type I glandular trichomes on leaves of the aphid-resistant genotype. According to microscopic observations and stain testing, these trichomes store and secrete phenols and flavonoids. Free-choice tests were conducted to determine the effect of these glandular trichomes on A. gossypii preference, revealing that aphids reject leaf disks of TGR-1551 from the onset of the experiment. Additional experiments after removal of leaf type I glandular trichome exudates showed that A. gossypii preferred washed TGR-1551 leaf disks over unwashed disks, while this effect was not observed in experiments using washed and unwashed 'Bola de Oro' leaf disks. These results suggest that a high density of glandular trichomes and chemicals secreted by them deter A. gossypii and disturb aphid settling on TGR-1551.

Inheritance of trichomes and resistance to pod borer (Helicoverpa armigera) and their association in interspecific crosses between cultivated pigeonpea (Cajanus cajan) and its wild relative C. scarabaeoides

The legume pod borer, Helicoverpa armigera, is one of the most devastating pests of pigeonpea. High levels of resistance to pod borer have been reported in the wild relative of pigeonpea, Cajanus scarabaeoides. Trichomes (their type, orientation, density and length) and their exudates on pod wall surface play an important role in the ovipositional behavior and host selection process of insect herbivores. They have been widely exploited as an insect defense mechanism in number of crops. In the present investigation, inheritance of resistance to pod borer and different types of trichomes (A, B, C and D) on the pod wall surface in the parents (C. cajan and C. scarabaeoides) and their F1, F2, BC1 (C. cajan × F1), and F3 generations has been studied. Trichomes of the wild parents (high density of the non-glandular trichomes C and D, and glandular trichome B and low density of glandular trichome A) were dominant over the trichome features of C. cajan. A single dominant gene as indicated by the segregation patterns individually will govern each trait in the F2 and backcross generation. Segregation ratio of 3 (resistant): 1 (susceptible) for resistance to pod borer in the F2 generation under field conditions was corroborated with a ratio of 1:1 in the backcross generation, and the ratio of 1 non-segregating (resistant): 2 segregating (3 resistant: 1 susceptible): 1 non-segregating (susceptible) in F3 generation. Similar results were obtained for pod borer resistance under no-choice conditions. Resistance to pod borer and trichomes associated with it (low density of type A trichome and high density of type C) are governed individually by a dominant allele of a single gene in C. scarabaeoides. Following backcrossing, these traits can be transferred from C. scarabaeoides into the cultivated background.

Influence of Canopy Height and Fertilization Levels on the Resistance of Lycopersicon Hirsutum to Aculops Lycopersici (Acari: Eriophyidae)

The objective of this work was to study the effect of NK fertilization levels and canopy height on the resistance of Lycopersicon hirsutum and Lycopersicon esculentum to Aculops lycopersici (Acari: Eriophydae). The effects of NK fertilization levels and canopy height in the leaf size and density of trichomes and their effects on tridecan-2-one (2-TD) and undecan-2-one (2-UD) limiting the attack of A. lycopersici on tomato plants were assessed. Different NK fertilization levels had no effect on the resistance of L. hirsutum to A. lycopersici. No significant differences were found in attack rates of this mite on leaves of the top and median parts of L. hirsutum canopy. The type and density of trichomes were the main determining factor of A. lycopersici attack on tomato plants. High trichome densities and type VI glandular trichomes which produce tridecan-2-one are important resistance factors on tomato plants. L. hirsutum showed a high resistance level to A. lycopersici due to high densities of type VI glandular trichomes and consequently higher levels of tridecan-2-one in its leaves.