scholarly journals Histochemical examination on principal collagen fibers in periodontal ligaments of ascorbic acid-deficient ODS-od/od rats

Microscopy ◽  
2019 ◽  
Vol 68 (5) ◽  
pp. 349-358 ◽  
Author(s):  
Tomoka Hasegawa ◽  
Yukina Miyamoto-Takasaki ◽  
Miki Abe ◽  
Zixuan Qiu ◽  
Tomomaya Yamamoto ◽  
...  

Abstract In this study, we aimed to clarify the role of ascorbic acid in collagen synthesis in periodontal ligaments using osteogenic disorder Shionogi (ODS)/ShiJcl-od/od rats lacking L-gulonolactone oxidase. These rats cannot synthesize ascorbic acid in vivo. Eight-week-old ODS/ShiJcl-od/od male rats were administered ascorbic acid solution at a concentration of 200 mg/dL (control group, n = 6) or ascorbic acid solution at concentration of 0.3 mg/dL (insufficient group, n = 12). Six rats of the insufficient group were then given with ascorbic acid solution at concentration of 200 mg/dL for additional 3 weeks (rescued group, n = 6), and then, their mandibles were histochemically examined. Consequently, the insufficient group specimens were seen to possess fewer collagen fibers, and silver impregnation revealed numerous fine, reticular fiber-like fibrils branching off from collagen in the periodontal ligaments. In control group, faint immunoreactivities for matrix metalloproteinase (MMP)2 and cathepsin H were seen in the periphery of blood vessels and throughout the ligament, respectively. In contrast, in the insufficient group, intense MMP2-immunoreactivity was observed to be associated with collagen fibrils in the periodontal ligaments, and cathepsin H-immunopositivity was seen in ligamentous cells. The rescued group showed abundant collagen fibers filling the periodontal ligament space. Under transmission electron microscopy, ligamentous fibroblasts incorporated collagen fibrils into tubular endosomes/lysosomes while simultaneously synthesizing collagen fibril bundles. Thus, ascorbic acid insufficiency affected the immunolocalization of cathepsin H and MMP2; however, ligamentous fibroblasts appear to possess the potential to synthesize collagen fibers when supplied with ascorbic acid.

Author(s):  
Saidul Islam Khan ◽  
Mahmuda Begum ◽  
Rama Chowdhury ◽  
Md. Mizanur Rahman ◽  
Muhammad Asaduzzaman

Background and objectives: The hepatoprotective activity of vitamin E and C is evident due to their ability of modulating the antioxidant pathway. In this study, we have evaluated the effects of α-tocopherol and ascorbic acid on paracetamol induced liver damage with offsetting various levels of drug treatment following an in vivo experimental protocol on Wistar albino male rats. Materials and Methods: The level of lipid peroxidation as well as histological examination of liver tissues were observed among 50 Wistar albino male rats to evaluate hepatoprotective effect of α-tocopherol and ascorbic acid on hepatocytes. The experiment was divided into 5 groups (10 rats in each group)- Basal control group (Group-I, with propylene glycol), Paracetamol treated control group (Group –II), α-tocopherol pretreated & paracetamol treated group (Group –III), Ascorbic acid pretreated & paracetamol treated group (Group –IV) and Ascorbic acid pretreated & paracetamol treated group (Group –IV). Results: The mean (± SD) Malondialdehyde (MDA) concentration were significantly reduced in α-tocopherol pretreated and paracetamol treated group (P<0.001), Ascorbic acid pretreated and paracetamol treated group (P≤0.05) and combined α-tocopherol with ascorbic acid pretreated & paracetamol treated group (P<0.001). Statistically significant differences in histological findings of rat liver were observed in paracetamol treated control group (P<0.001), ascorbic acid pretreated and paracetamol treated group (P<0.001). The serum alanine aminotransferase (ALT) level was also significantly higher in paracetamol treated group (P<0.001), α-tocopherol pretreated plus paracetamol treated group (P≤0.05) and in ascorbic acid pretreated plus paracetamol treated group (P<0.001). Conclusion: The combined pretreatment of α-tocopherol & ascorbic acid have better hepatoprotective effects than α-tocopherol or ascorbic acid alone against paracetamol induced liver damage. The decrement of free radicals produced by vitamin E could be a better hepatoprotective antioxidant than vitamin C in paracetamol induced toxicity.


Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.


Author(s):  
Hanagasaki Takashi ◽  

Luffa (Luffa cylindrica Roem.) is a popular vegetable in Okinawa, and it has abundant nutrients, including γ-aminobutyric acid (GABA). We focused on GABA content in luffa, taking into consideration registering it as foods with functional claims in Japan. Besides, when selling cut luffa and frozen cut luffa at supermarkets, they are supposed to get browned due to air exposure and other causes. In the present study, we developed the prevention method of browning cut luffa and frozen cut luffa using 0.5 %, 1.0 %, 2.0 %, and 4.0 % ascorbic acid solution. It was found that 55 L of 4.0 % ascorbic acid solution could be used for soaking of 70 kg cut luffa to prevent browning, but GABA content decreased in food processing of luffa in the factory. Besides, GABA content in luffa fruits was found not to change during storage for 07 days at room temperature after harvest.


1999 ◽  
Vol 47 (1) ◽  
pp. 69 ◽  
Author(s):  
Yohannes M. S. Samosir ◽  
Ian D. Godwin ◽  
Stephen W. Adkins

A new technique for coconut (Cocos nucifera L.) germplasm collection was evaluated in the laboratory and tested in the field in Indonesia. The technique involved the non-sterile isolation of embryos, and incubation in sterile ascorbic acid solution (1 mg L –1 ) at 5 1˚C in the dark. During this incubation period the embryos could be transported and/or stored for a period of up to 4 days without embryo viability loss. Following this period the embryos were surface sterilised with sodium hypochlorite (1.5% w/v) for 20 min, washed with sterile water and cultured in a liquid Y3 basal nutrient medium supplemented with Morel and Wetmore vitamins, sucrose (175 mM) and activated charcoal (2.5 g L –1 ). After two weeks the embryos were subcultured onto a solid medium of similar constitution to encourage germination. Germinated embryos grew and produced healthy plants with normal morphology. Despite mild chilling injury as indicated by elevated ethylene production and solute leakage, the transported embryos retained viability with normal morphology. Using the low-temperature incubation treatment, the microorganism density in the ascorbic acid solution was kept low while that around other embryos kept at higher temperatures (25˚C) increased. Even though embryos were exposed to a low-temperature treatment for up to 4 days they were able to germinate (95% viable) and grow in an identical fashion to freshly cultured embryos.


2001 ◽  
Vol 64 (8) ◽  
pp. 1244-1248 ◽  
Author(s):  
JENNIFER A. BURNHAM ◽  
PATRICIA A. KENDALL ◽  
JOHN N. SOFOS

Destruction of Escherichia coli O157:H7 was evaluated on inoculated apple slices dehydrated at two temperatures with and without application of predrying treatments. Half-ring slices (0.6 cm thick) of peeled and cored Gala apples were inoculated by immersion for 30 min in a four-strain composite inoculum of E. coli O157:H7. The inoculated slices (8.7 to 9.4 log CFU/g) either received no predrying treatment (control), were soaked for 15 min in a 3.4% ascorbic acid solution, or were steam blanched for 3 min at 88°C immediately prior to drying at 57.2 or 62.8°C for up to 6 h. Samples were plated on tryptic soy (TSA) and sorbitol MacConkey (SMAC) agar media for direct enumeration of surviving bacterial populations. Steam blanching changed initial inoculation levels by +0.3 to −0.7 log CFU/g, while immersion in the ascorbic acid solution reduced the inoculation levels by 1.4 to 1.6 log CFU/g. Dehydration of control samples for 6 h reduced mean bacterial populations by 2.9 log CFU/g (TSA or SMAC) at 57.2°C and by 3.3 (SMAC) and 3.5 (TSA) log CFU/g at 62.8°C. Mean decreases from initial inoculum levels for steam-blanched slices after 6 h of drying were 2.1 (SMAC) and 2.0 (TSA) log CFU/g at 57.2°C, and 3.6 (TSA or SMAC) log CFU/g at 62.8°C. In contrast, initial bacterial populations on ascorbic acid–pretreated apple slices declined by 5.0 (SMAC) and 5.1 (TSA) log CFU/g after 3 h of dehydration at 57.2°C, and by 7.3 (SMAC) and 6.9 (TSA) log CFU/g after 3 h at 62.8°C. Reductions on slices treated with ascorbic acid were in the range of 8.0 to 8.3 log CFU/g after 6 h of drying, irrespective of drying temperature or agar medium used. The results of immersing apple slices in a 3.4% ascorbic acid solution for 15 min prior to drying indicate that a predrying treatment enhances the destruction of E. coli O157:H7 on home-dried apple products.


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