scholarly journals The Goitrogen 3-Hydroxy-4(1H)-Pyridone, a RuminaI Metabolite From Leucaena Leucocephala: Effects in Mice and Rats

1979 ◽  
Vol 32 (1) ◽  
pp. 27 ◽  
Author(s):  
MP Hegarty ◽  
Chew Phong Lee ◽  
GS Christie ◽  
RD Court ◽  
KP Haydock

Mice fed a diet containing 1 % (w/w) 3-hydroxy-4(IH)-pyridone (DHP) developed goitre even with a diet high in iodine whereas mimosine (0�5% w/w) did not produce goitre even with a low-iodine diet. Thyroid enlargement was apparent (measured morphometrically) by the 7th week and was advanced by the 11 th week. Histologically the goitre was hyperplastic in type. No marked histological changes were found in other organs of mice fed DHP or any organs of mice fed mimosine, except for soine atrophy of hair follicles.

2016 ◽  
Vol 136 (3) ◽  
pp. 584-592 ◽  
Author(s):  
Ji-Seon Yoon ◽  
Mira Choi ◽  
Chang Yup Shin ◽  
Seung Hwan Paik ◽  
Kyu Han Kim ◽  
...  

2020 ◽  
Author(s):  
Marc Fourneau ◽  
Caroline Canon ◽  
Daniel Van Vlaender ◽  
Matthew J. Collins ◽  
Sarah Fiddyment ◽  
...  

Abstract We report a simple histological study on skin biopsies from young domestic sheep following each step in transformation from skin to parchment production. Histological analyses were conducted; before and after lime treatment, hair removal, and stretching. Sections were fixed and stained using a variety of histological stains to identify the presence of different molecular classes and the fibrous proteins, collagen and elastin. The results reveal surprisingly few histological changes in most steps in the production process. However, very visible changes in the supramolecular ordering of skin macromolecules (elastin, collagen) occur during the final stage of parchment production when stretched on the frame. Collagen fibres and hair follicles were all strongly re-oriented in the direction of strain. Surprisingly, despite the thinness of the lambskin and the exhaustive treatment in lime, not all fats were saponified and even in the final product Oil Red O stained fat bodies were detectable on the hair side of the skin.


2018 ◽  
pp. 1706-1711
Author(s):  
Ahmed Khalaf Ali ◽  
Adamu Abdul Abubakar ◽  
Ubedullah Kaka ◽  
Zamri Radzi ◽  
Nurul Hayah Khairuddin ◽  
...  

Aim: Tissue expansion is an applicable technique to reconstruct many surgical defects. The aim of this research was to evaluate the histological changes caused by immediate skin tissue expansion in rats as an animal model. Materials and Methods: Immediate skin tissue expansion in 18 adult female rats was performed using three different sizes (small, medium, and big) of polymethylmethacrylate tissue expanders at the dorsal surface of the metatarsal area of the right limb. The contralateral limb was served as the control. The tissue expanders were surgically implanted and kept for 15 days. Results: The immediate skin expansion resulted in histological changes such as the increased thickness of the epidermal layer, the reduction of the dermal layer, an elevated number of fibroblast as well as increased vascularity. Furthermore, skin adnexal structures such as hair follicles and sebaceous glands were farther apart. Conclusion: The rat skin was able to rapidly adjust and compensate against a specific range of immediate mechanical expansion. The histological changes suggest that the tissues were prepared to withstand the increased external forces, in addition to create possibly additional skin in a relatively short-term period.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wang Wei ◽  
Qi Michu ◽  
Dong Wenjuan ◽  
Wen Jianrong ◽  
Han Zhibing ◽  
...  

Abstract To observe the histological changes in human skin within 32 days after death to explore its potential significance in forensic practice. The intact full-thickness skin and subcutaneous tissue from the sternum of eight corpses were placed in an environment of 4–6 °C for 4 h, 6 h, 12 h, 18 h, 24 h, 36 h, 48 h, 60 h, 72 h, 84 h, 96 h, 6 d, 8 d, 10 d, 12 d, 16 d, 20 d, 24 d, 28 d, and 32 d. Then, the whole layer of the skin was stained with haematoxylin & eosin. The histological morphology of the epidermis, dermis and appendages (sweat glands, hair follicles, and sebaceous glands) was observed under an light microscope. The epithelial nucleus condensed at 24 h after death, and cell lysis was exhausted after 20 days. The post-mortem changes in the dermis occurred later than that of the epidermis (72 h), but after epidermal changes started, the change was more rapid. At 16 d, the layers had become homogenized. The epidermis and dermis had completely separated 24 d after death. The changes in the sweat glands appeared earlier (24 h) and disappeared later (32 days); the sebaceous glands and hair follicles began to undergo degenerative changes at 96 h after death, and at approximately 20 d, only their contour remained. There were individual and structural differences in the post-mortem histological changes in the skin. At 4–6 °C ambient temperature, some structures of the human skin still exist for a long time after death, and these structures can be used to identify the source of the tissue; post-mortem histological changes in the skin occur at specific times, which can be used to help infer the time of death. A comprehensive observation of changes in the skin composition/structure is required to comprehensively analyse possible death times.


1992 ◽  
Vol 4 (2) ◽  
pp. 128
Author(s):  
R. Muraki ◽  
H. Fujisawa ◽  
M. Hoshino ◽  
F. Otsuka ◽  
T. Sata ◽  
...  

2021 ◽  
Vol 12 (2) ◽  
pp. 206-211
Author(s):  
Y. V. Kisera ◽  
Y. V. Martyniv ◽  
B. V. Gutyj

Microsporіа affect different species of animals and humans. The high contagiousness of the pathogen determines the relevance of research into this disease. Microsporum canis is the pathogen that most often causes microsporia. Weakened functions of the immune system and violation of the epithelial barrier of the skin are a favourable factor that causes microspores. The main source of infection is cats, which are involved in the storage and transmission of the pathogen. To clarify the dynamics of morphological, immunological and histological changes in microsporia, blood and skin studies of guinea pigs infected with M. canis were carried out. The animals were divided into two groups of 6 guinea pigs (healthy and sick). Test material (blood and skin) was taken from clinically healthy and sick animals 21 and 42 days after infection. The number of erythrocytes and leukocytes was determined by counting them in the Goryaev chamber, the hemoglobin content – by the method of cyanide hemoglobin. The leukogram was derived based on the counting and differentiation of 200 leukocyte cells in blood smears. Material for histological examination (pieces of skin) was fixed in 10–12% cooled solution of neutral formalin, followed by pouring in paraffin according to the scheme proposed by G. A. Merkulov. The obtained results demonstrated that leukocytosis developed in guinea pigs with microsporia on the 21st and 42nd days; the number of rod-shaped neutrophils increased, that of segmental neutrophils decreased, and that of ESR increased. The immune response to the course of microsporia was manifested in an increase in the percentage of T-lymphocytes, T-suppressors and a decrease in T-helper cells and an increase in T-killers compared with healthy animals. Histological examination showed that on the 21st day after infection, hyphae and spores of the fungus M. canis were localized in the skin. There is swelling of the dermis, stratification of collagen fibers and the accumulation of inflammatory infiltrates around the hair follicles. On the 42nd day, the infiltration spread and dystrophic changes in the skin occurred in the form of desquamation of the epidermis and the formation of acanthosis and hyperkeratosis on the surface of the dermis. The conducted research will allow further assessment of the course of microsporia under the action of various drugs and help establish the most effective method of treatment.


2020 ◽  
Author(s):  
Marc Fourneau ◽  
Caroline Canon ◽  
Daniel Van Vlaender ◽  
Matthew J. Collins ◽  
Sarah Fiddyment ◽  
...  

Abstract We report a simple histological study on skin biopsies from young domestic sheep following each step in transformation from skin to parchment production. During the recreation of historical parchment manufacture, histological analyses were conducted; before and after lime treatment, hair removal, and stretching. Sections were fixed and stained using a variety of histological stains to identify the presence of different molecular classes and the fibrous proteins, collagen and elastin. The results reveal surprisingly few histological changes in most steps in the production process. However, very visible changes in the supramolecular ordering of skin macromolecules (elastin, collagen) occur during the final stage of parchment production when stretched on the frame. Collagen fibres and hair follicles were all strongly re-oriented in the direction of strain. Surprisingly despite the thinness of the lambskin and the exhaustive treatment in lime, not all fats were saponified and even in the final product Oil Red O stained fat bodies were detectable on the hair side of the skin. We believe this study will help compensate for the lack of sources on microscopic changes in parchment during the recreation of its historical manufacture.


Author(s):  
Emil Bernstein

An interesting method for examining structures in g. pig skin has been developed. By modifying an existing technique for splitting skin into its two main components—epidermis and dermis—we can in effect create new surfaces which can be examined with the scanning electron microscope (SEM). Although this method is not offered as a complete substitute for sectioning, it provides the investigator with a means for examining certain structures such as hair follicles and glands intact. The great depth of field of the SEM complements the technique so that a very “realistic” picture of the organ is obtained.


Author(s):  
Burton B. Silver ◽  
Theodore Lawwill

Dutch-belted 1 to 2.5 kg anesthetized rabbits were exposed to either xenon or argon laser light administered in a broad band, designed to cover large areas of the retina. For laser exposure, the pupil was dilated with atropine sulfate 1% and pheny lephrine 10%. All of the laser generated power was within a band centered at 5145.0 Anstroms. Established threshold for 4 hour exposures to laser irradiation are in the order of 25-35 microwatts/cm2. Animals examined for ultrastructural changes received 4 hour threshold doses. These animals exhibited ERG, opthalmascopic, and histological changes consistent with threshold damage.One month following exposure the rabbits were killed with pentobarbitol. The eyes were immediately enucleated and dissected while bathed in 3% phosphate buffered gluteraldehyde.


2012 ◽  
Vol 60 (S 01) ◽  
Author(s):  
J Scheumann ◽  
MS Bischoff ◽  
C Heilmann ◽  
M Siepe ◽  
F Roder ◽  
...  

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