Regeneration of vascular tissue through redifferentiation of interxylary phloem after complete girdling in Aquilaria sinensis

IAWA Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Bei Luo ◽  
Arata Yoshinaga ◽  
Tatsuya Awano ◽  
Keiji Takabe ◽  
Takao Itoh

Abstract We studied the time-course of stem response for six months following complete girdling in branches of Aquilaria sinensis to determine the potential role of interxylary phloem (IP) in this response. It was found that the vascular cambium, as well as its derivative secondary xylem and phloem, regenerated fully through redifferentiation of IP. We confirmed that vascular cambium regenerated within one month after girdling based on observation of new vessels, IP, and secondary phloem fibers. The time-course study showed that IPs made connections with each other, merged, and became larger through the proliferation of IPs parenchyma cells and the cleaving of secondary xylem in a narrow zone 400 to 1000 μm deep inside the girdled edge. This led to the formation of a complete circular sheath of vascular cambium, followed by the regeneration of vascular tissue. It is worth noting that the secondary xylem is regenerated always following the formation of a thick belt of wound xylem.

Circulation ◽  
2015 ◽  
Vol 131 (suppl_2) ◽  
Author(s):  
Kentaro Ueno

Objective: Circulating platelet-neutrophil aggregates play a crucial role in amplifying acute inflammation and could promote adverse effects involving vascular injury. The aim of this study was to clarify the role of platelet-neutrophil aggregates in patients with Kawasaki disease (KD). Methods: We analyzed 40 patients with KD (30 intravenous immunoglobulin [IVIG] responders and 10 IVIG non-responders), 7 febrile patients with bacterial infections, and 9 normal volunteers. Thirty-three patients with KD were treated with IVIG alone, and remaining seven were treated with IVIG plus prednisolone. We evaluated the rate of platelet-neutrophil aggregates and measured the platelet factor 4 (PF4) and β-thromboglobulin (β-TG) levels in patients with KD. Results: The rate of platelet-neutrophil aggregates was significantly higher in patients with KD than in both patients with bacterial infection and normal volunteers. There was a trend toward increased rate of platelet-neutrophil aggregates within 2 or 3 days after IVIG than before IVIG. The rate of platelet-neutrophil aggregates was significantly higher in patients who showed coronary artery abnormalities (CAA) than in those who showed without CAA and was correlated with PF4 and β-TG levels in patients with KD. Comparing time course analysis, the rate of platelet-neutrophil aggregates was significantly decreased in patients treated with IVIG plus prednisolone than in those treated with IVIG alone. Conclusions: Our findings demonstrate that platelet-neutrophil aggregates play a crucial role in regulating vasculitis, and are involved in the development of CAA. Additional prednisolone treatment in the acute phase of KD might have a potential role in inhibiting amplified reciprocal inflammatory activation by suppressing platelet-neutrophil aggregates.


1993 ◽  
Vol 50 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Daniel J. Conley ◽  
Claire L. Schelske

Amorphous silica, e.g. biogenic silica (BSi), contained in diatoms and in sponge spicules was estimated by time course extraction from surficial sediment samples of 82 Florida lakes. Separation of diatom BSi from sponge BSi was based on the observation that diatoms completely dissolve within 2 h of digestion at 85 °C in 1% Na2CO3 whereas sponge spicules, which are generally larger than diatoms, take longer to dissolve. Sponge samples from four lakes in northern Wisconsin ranged widely in the time required to dissolve completely (1.5–12 h), but no significant differences were observed in the rates of dissolution among the lakes. In Florida lake sediments, diatom BSi averaged 49.2 (± 48.4) mg∙g−1 and sponge BSi averaged 31.5 (± 35.8) mg∙g−1, with sponge BSi comprising on average 40% of the total amorphous silica extracted. The procedure for separating diatom BSi from sponge BSi underestimates sponge BSi because smaller and/or lightly silicified components of sponges are completely dissolved early in the digestion. However, because sponge spicules comprise a significant fraction of total amorphous silica extracted, we hypothesize that sponge spicules, which on average are larger than diatoms and require a longer time for complete dissolution, may constitute an important sink for BSi in Florida lakes.


IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 109-115 ◽  
Author(s):  
C. Kajii ◽  
T. Morita ◽  
K. Kuroda

The distribution and structure of laticifers in Ficus carica L. were investigated in a current-year branch and an 8-year-old trunk, using serial sections stained with safranin-fast green or nile blue. In the 8-year-old trunk, laticifers were found not only in the cortex, secondary phloem, and pith, but also in the secondary xylem. The laticifers in the phloem and xylem were of the branched, non-articulated type. In addition, horizontal laticifers extending from the phloem through the cambium to the xylem were found in some rays. Laticifers penetrating the cambial initial layer elongated in the cambial zone without cell division. Activation of latex production occurred after wounding of cortex and phloem, and the latex exuded from the cut site of laticifers into the surrounding wounded tissue and broken cells. The potential role of laticifers in defense of F. carica against certain pathogens is discussed.


2005 ◽  
Vol 288 (5) ◽  
pp. E965-E972 ◽  
Author(s):  
Elaine A. Hsieh ◽  
Christine M. Chai ◽  
Marc K. Hellerstein

Reduced cell proliferation may mediate anticarcinogenic effects of caloric restriction (CR). Using heavy water (2H2O) labeling, we investigated the cell proliferation response to CR in detail, including time course, effect of refeeding, and role of intermittent feeding with 5% CR. In the time-course study, 8-wk-old female C57BL/6J mice were placed on a 33% CR regimen (fed 3 times/wk) for varying durations. Compared with responses in controls fed ad libitum (AL), proliferation rates of keratinocytes, mammary epithelial cells, and T cells were markedly reduced within 2 wk of CR. In mice fed 95% ad libitum (C95, fed 3 times/wk), cell proliferation was also reduced in all tissues so that differences from 33% CR were only significant at 1 mo. In the refeeding study, mice were refed a C95 diet for varying durations after 1 mo of 33% CR. Cell proliferation rebounded to a suprabasal rate in all tissues after 2 wk of refeeding and then normalized after 2 mo, although the C95 group again exhibited lower cell proliferation than the AL group. The role of intermittent feeding was studied by comparing 33% CR and C95 animals (both fed intermittently) with animals fed isocalorically either daily or continuously by pellet dispenser. Intermittent feeding had no additive effect on 33% CR but reduced cell proliferation in all tissues at the 95% caloric intake level. In summary, the CR effect on cell proliferation is potent, rapid, and reversible in several tissues, and an intermittent feeding pattern reproduces much of the effect in the absence of substantial CR.


2009 ◽  
Vol 23 (S1) ◽  
Author(s):  
Yester Skayian ◽  
Arthur Yu He ◽  
Caroline Ojaimi ◽  
Thomas H Hintze

2001 ◽  
Vol 47 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Beverly A. S. REYES ◽  
Sakiko YAMADA ◽  
Maria Amelita C. ESTACIO ◽  
Kei-Ichiro MAEDA ◽  
Hiroko TSUKAMURA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rituja Saxena ◽  
Parul Mittal ◽  
Cecile Clavaud ◽  
Darshan B. Dhakan ◽  
Nita Roy ◽  
...  

AbstractDandruff is a recurrent chronic scalp disorder, affecting majority of the population worldwide. Recently a metagenomic study of the Indian scalp microbiome described an imperative role of bacterial commensals in providing essential vitamins and amino acids to the scalp. Coconut oil and its formulations are commonly applied on the scalp in several parts of the world to maintain scalp health. Thus, in this study we examined the effect of topical application of coconut oil on the scalp microbiome (bacterial and fungal) at the taxonomic and functional levels and their correlation with scalp physiological parameters. A 16-weeks-long time-course study was performed including 12-weeks of treatment and 4-weeks of relapse phase on a cohort of 140 (70 healthy and 70 dandruff) Indian women, resulting in ~ 900 metagenomic samples. After the treatment phase, an increase in the abundance of Cutibacterium acnes and Malassezia globosa in dandruff scalp was observed, which were negatively correlated to dandruff parameters. At the functional level, an enrichment of healthy scalp-related bacterial pathways, such as biotin metabolism and decrease in the fungal pathogenesis pathways was observed. The study provides novel insights on the effect of coconut oil in maintaining a healthy scalp and in modulating the scalp microbiome.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Anouar Hafiane ◽  
John K Bielicki ◽  
Jan O Johansson ◽  
Jacques Genest

Microparticles (MPS) are lipoprotein-sized structures created by the ABCA1 transporter. Their biological roles in health and in disease remain unknown. Here, we study MPS released from baby hamster kidney (BHK) cells stably expressing ABCA1 and human THP-1 cells also expressing ABCA1. Media cell culture was first collected from BHK-ABCA1 expressing cells after (45min, 2, 4, 8, and 24h) incubation. After centrifugation (4000xg for 15min and 10000xg for 30min) to remove cell debris, the supernatant was passed through a 10kDa cutoff filter and subsequently subjected to analytical FPLC. FPLC analysis shows creation of a single peak in the presence of ABCA1 but not in mock-transfected BHK cells. In a time-course study, the estimated hydrodynamic diameter remained stable (≥20nm). After 8h incubation of BHK cell with apoA-I or an apo-E mimetic peptide, CS-6253 (1μM), ABCA1 mediated formation of MPS of similar size with a significant increase in 3[H]-FC content than those generated by ABCA1 alone, (373±23 % cpm, P<0.05) and (277±60 % cpm, P<0.05) respectively. This was associated with highly lipidated nHDL-CS-6253 compararely to nHDL-apoA-I (4535±72 % cpm, P<0.001 versus 1059±14 % cpm) respectively. This data suggests that MPS formations are an integral component of cellular cholesterol efflux. Also, MPS do not contain CS-6253 when ABCA1 cells were incubated with the peptide as confirmed by western blotting similar to MPS generated from ABCA1 cells generated by apoA-I incubation. Cholesterol is effluxed more to nHDL-CS-6253 (14±7.68, % cpm, P<0.01 than to MPS 1±0.10, % cpm, 24h; P<0.01) similar to apoA-I. Depletion of membrane cholesterol by methyl-β-cyclodextrin treatment impaired HDL genesis and decrease MPS release. Detection of flotellin-2 protein enriched in MPS in total cell lysate indicated that these MPS may be related to exosomes. MPS generation was also characterized in THP-1 cells for further molecular characterization. We conclude that MPS are formed by ABCA1 in diverse cell types and the cholesterol content is dependent on activation by apo A-I or mimetic peptides. The physiological role of MPS remains to be understood. These particles may be transporters of lipids and nucleic acids.


1978 ◽  
Vol 148 (5) ◽  
pp. 1146-1160 ◽  
Author(s):  
A J Husband ◽  
J L Gowans

The aims of this paper were to establish the origin of cells producing IgA antibody to cholera toxoid in the lamina propria of the small intestine and to define the role of antigen in their distribution. The use of Thirty-Vella loops made it possible to restrict antigenic challenge to a defined segment of the intestine in rats which had been primed i.p. with toxoid in Freund's complete adjuvant. The anti-toxin-containing cells (ACC) which appeared in the draining thoracic duct lymph after challenge of a loop were almost all of IgA specificity and their numbers were proportional to the length of intestine exposed to antigen. The abolition of this cellular response which occurred when Peyer's patches (PP) were removed from a loop before challenge and the failure of mesenteric lymphadenectomy significantly to affect the response indicated that ACC originated exclusively from PP. Cell transfer studies showed that although nonrecirculating large lymphocytes gave rise to ACC in the lamina propria, some of the recirculating small lymphocytes also developed subsequently into ACC. Counts of ACC in the lamina propria of challenged loops were consistently greater than in nonchallenged loops although some ACC were always present in the latter. However, a time-course study on the appearance of ACC in the lamina propria of cannulated rats given a single dose of thoracic duct lymphocytes from immunized donors demonstrated that ACC continued to accumulate and persist in challenged loops but only appeared transiently in nonchallenged loops. These transients did not migrate from the lamina propria back into the lymph and they presumably died in situ. The increase in the number of ACC in loops which had been challenged with antigen was probably due both to cell division in the lamina propria and to the development of new ACC from recirculating lymphocytes which had been recruited into the loop. Thus, the cells which give rise to intestinal ACC can migrate into the lamina propria independently of antigen, but antigen has a profound effect on the location, magnitude, and persistence of the response.


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