scholarly journals Effects of Internally Administered N-[5-( 4-Aminophenoxy)Pentyl]Phthalimide on Wool Follicles and Skin of Sheep

1980 ◽  
Vol 33 (2) ◽  
pp. 183 ◽  
Author(s):  
RE Chapman ◽  
RDG Rigby
Keyword(s):  
Body Weight ◽  
Cell Division ◽  
Mitotic Activity ◽  
Sebaceous Gland ◽  
Skin Surface ◽  
Skin Thickness ◽  
Sebaceous Glands ◽  
Wool Follicle ◽  
Dark Staining ◽  
Dermal Papillae

When N-[5-(4-aminophenoxy)pentyl]phthalimide was administered to sheep in sufficient quantities to permit manual removal of the fleece (400 mg/kg body weight orally, or 75 mg/kg body weight intravenously during a period of 48 h), cell division ceased in the wool follicle bulbs within 1 day. Dark-staining bodies (autophagic vacuoles) developed concomitantly in the cytoplasm of the bulb cells. The nuclei of cells in the keratogenous zones of the fibres became pycnotic 2 days after dosing and subsequent keratinization of these portions of the fibres was impaired. All the follicles retrogressed prior to day 7 after dosing, and the root ends which formed on the fibres moved towards the skin surface, reaching the level of the sebaceous glands by day 7. At this time mitotic activity recommenced around the dermal papillae in about 50% of the follicles. A small number of tips of new fibres emerged from the skin surface of some of the depilated sheep by day 14. The root ends on the fibres in the fleeces harvested at days 7-15 were fragmented with various degrees of taper. By 21 days, most follicles were growing emergent fibres. Thickening of the epidermis, increase in sebaceous gland size and decrease in skin thickness occurred in some of the depilated sheep.

New Therapy for Severe Cystic Acne

PEDIATRICS ◽  
1983 ◽  
Vol 72 (2) ◽  
pp. 258-259
Author(s):  
Keyword(s):  
Body Weight ◽  
Retinoic Acid ◽  
Sebaceous Gland ◽  
Skin Surface ◽  
Surface Lipid ◽  
Test Results ◽  
Laboratory Test Results ◽  
Skin Surface Lipid ◽  
Systemic Antibiotics ◽  
Sebum Excretion

Isotretinoin, 13-cis-retinoic acid (Accutane, Hoffmann-LaRoche), is brightening the bleak outlook for adolescents and young adults with nodular, cystic, and conglobate acne—a severe, scarring disease—that has resisted treatment with topical or systemic antibiotics, benzoyl peroxide, retinoic acid, and intralesional corticosteroids. Adolescents with less severe forms of acne who learn about the therapeutic triumphs of isotretinoin in severe recalcitrant nodular and cystic acne may assume that the drug also would be beneficial for them. Pediatricians should inform these adolescents that the drug has not been studied in, found effective for, or labeled for the treatment of typical acne. Patients with multiple, active, deep dermal or subcutaneous cystic and nodular acne lesions are usually given 1 to 2 mg of isotretinoin per kilogram of body weight per day (although dosage as low as 0.05 mg/kg/d has been reported as beneficial), orally, in two divided doses for 15 to 20 weeks or until the cyst count decreases by 70%, if this happens sooner than 15 to 20 weeks. Use of this drug is associated with a reduction in sebaceous gland size and activity (a decrease in sebum excretion by as much as 75% to 90%), with inhibition of sebaceous cell differentiation, and with a reversion to prepubertal skin surface lipid composition. Although isotretinoin is expensive, a course of treatment usually clears the troublesome lesions and a prolonged remission often follows. Side effects and alterations in patients' laboratory test results do occur; these appear to be lessened by reduction in dosage and to be fully reversible when the drug is discontinued.

EFFECT OF OVARIECTOMY AT BIRTH ON THE REGULATION OF SEBACEOUS GLANDS IN RATS

1980 ◽  
Vol 86 (1) ◽  
pp. 179-182 ◽  
Author(s):  
YEE CHU TOH
Keyword(s):  
Body Weight ◽  
Early Stage ◽  
Skin Surface ◽  
The Body ◽  
Female Rats ◽  
Sprague Dawley ◽  
Sebaceous Glands ◽  
Intact Female ◽  
Male And Female Rats ◽  
Endocrine Organs

Inbred Sprague–Dawley rats were ovariectomized within 24 h of birth. Sham-operated and untreated male and female rats were also included for comparison. At the age of 80 days, the secretion rate of sebum was assessed from the amount of skin-surface lipids that could be extracted by acetone and which had been produced during 2 days. There were no differences in sebum secretion, when expressed both in relationship to body weight and to surface area of the body, when rats ovariectomized at birth, sham-operated and intact female rats were compared. The removal of the ovaries within 24 h of birth increased the body weight, however. Although the weights of the pituitary, thyroid and adrenal glands, when corrected for body weight, were significantly smaller in rats ovariectomized at birth than in the sham-operated or intact female rats, there were no statistically significant differences in the absolute weights of these endocrine organs between neonatally spayed rats and sham-operated animals. The uterus became atrophic in the absence of ovaries. It has been concluded that the presence or absence of ovaries in the early stage of life had no effect on the activity of the sebaceous glands.

Mitotic Activity Dynamics in Recalcitrant Seeds Acer sachharinum during Maturation and Germination

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 479c-479
Author(s):  
L. Kozeko ◽  
V. Troyan ◽  
L. Musatenko
Keyword(s):  
Cell Division ◽  
Mitotic Activity ◽  
Quiescent State ◽  
Activity Levels ◽  
Recalcitrant Seeds ◽  
Mature Embryos ◽  
Before And After ◽  
Orthodox Seeds ◽  
Mature Seeds ◽  
Activity Dynamics

In orthodox seeds the cell division within the embryo meristems arrests during maturation at embryo moisture content (MC) 65% to 47%, and the maturation completion and transition of seeds to quiescent state occurs at MC about 10%. The arrest of cycling happens asynchronously in different meristematic tissues during desiccation: first in shoot and then in root. The aim of this work was to define a mitotic activity dynamics in recalcitrant seeds with the high MC at maturation end and the absence of quiescent state characteristic of it. The object was seeds of Acer saccharinum, using widely for planting of greenery in Kiev city. The mitotic activity was determined in 0.5 mm of the embryo root pole (RP) and 0.5 mm of the shoot pole with embryo leaves (SP). The A. sachharinum seeds completed them maturation at MC 53% (FW basis). During maturation the mitotic index (MI) in RP decreased from 3.2% in immature seeds (at embryos MC 80%) to 0 in mature seeds and in SP–from 5.4% to 3.3%, respectively. Cell division in SP arrested by dehydration of mature embryos to MC 46% by PEG 6000 (30%). The seeds lost viability by desiccation to MC 34%. The mature seeds were able to germinate immediately after abscission. During seed germination the cell division reactived in RP and increased in SP already before root protrusion. In plantlets 10–15 mm long the MI increased to 8% in RP and 12% in SP. Thus, the strategy of immediate germination of recalcitrant A. sachharinum seeds includes a preservation of cell division in SP of mature embryos, in contrast with orthodox seeds, and high mitotic activity levels in meristems of germinating embryos before and after root protrusion.

Strain specific response of mice to IMQ-induced psoriasis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Murali Badanthadka ◽  
Lidwin D’Souza ◽  
Fathima Salwa
Keyword(s):  
Body Weight ◽  
Disease Severity ◽  
Histopathological Examination ◽  
Redox System ◽  
Mechanistic Study ◽  
Strain Effect ◽  
Skin Thickness ◽  
Specific Response ◽  
Psoriasis Area Severity Index ◽  
Pasi Score

Abstract Objectives Psoriasis is an autoimmune, inflammatory disease that needs a reliable animal model. Imiquimod (IMQ)-induced psoriasis is a widely used preclinical tool for psoriasis research. However, this model is sensitive to the genetic variation of mice. The present study explores mice’s genetic background on disease stability and severity induced by IMQ. Methods Three distinct strains of mice (Balb/c, C57BL/6, and Swiss albino) were divided into four groups (Vaseline, IMQ, IMQ+Clobetasol, and IMQ+Curcumin). Psoriasis area severity index (PASI) score, ear/back skin thickness, body weight alterations, and histopathological examination were employed to analyze disease severity. The spleen index studied the systemic effect. Strain effect on oxidative stress induced by IMQ was evaluated by estimating antioxidant factors, superoxide dismutase (SOD), catalase, and glutathione (GSH). Results IMQ application resulted in increased PASI score, thickness, and alterations in body weight, confirming disease development in all the mice. However, the disease stability/severity between these strains was not identical. Although IMQ application caused splenomegaly, IMQ+curcumin treated C57BL/6 mice demonstrated a synergistic effect of IMQ and curcumin on the spleen resulting in increased splenomegaly. Decreased cellular enzyme activity in SOD, Catalase, and levels of GSH was observed in IMQ challenged mice, indicating the participation of the redox system in the genesis of the disease that was comparable among the strains. Conclusions These results indicate the existence of strain-dependent development of the disease. The Swiss model was found to be better in terms of disease severity and stability than other models. Further, a detailed mechanistic study might help to explain the pathological difference between these strains.

Postpollination placental development of a diploid Solatium tuberosum

1988 ◽  
Vol 66 (9) ◽  
pp. 1813-1817 ◽  
Author(s):  
A. Randall Olson
Keyword(s):  
Solanum Tuberosum ◽  
Cell Division ◽  
Mitotic Activity ◽  
Solanum Tuberosum L ◽  
Cell Enlargement ◽  
Placental Development ◽  
Developing Seeds ◽  
Solatium Tuberosum

Gynoecial placentation of Solanum tuberosum L. is axile with each parenchymatous placenta covered with numerous ovules. Three days after pollination, mitotic activity in the placental surface and subjacent layers initiates tissue proliferations, which develop between the ovules. Continued cell division and subsequent cell enlargement result in expanded placental projections, which separate the developing seeds from one another and form an interface with the inner pericarp within 10 – 12 days after pollination. Eventually, the placenta fills the remaining ovarian locular space and embeds the seeds.

scholarly journals Isolation of human sebaceous glands and cultivation of sebaceous gland-derived cells as an in vitro model

1989 ◽  
Vol 93 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Longqing Xia ◽  
Christos Zouboulis ◽  
Michael Detmar ◽  
Augusto Mayer-da-Silva ◽  
Rudolf Stadler ◽  
...  
Keyword(s):  
Sebaceous Gland ◽  
In Vitro Model ◽  
Sebaceous Glands ◽  
Vitro Model

Action of nuclear and cytoplasmic fractions of liver homogenate on liver growth in the chick embryo

Development ◽  
1968 ◽  
Vol 20 (1) ◽  
pp. 53-71
Author(s):  
G. D. Tumanishvili ◽  
Naira V. Salamatina
Keyword(s):  
Cell Division ◽  
Chick Embryo ◽  
Mitotic Activity ◽  
Liver Homogenate ◽  
Liver Growth ◽  
Organ Growth ◽  
Tissue Volume ◽  
Number Of Cells

A number of observations have been made during a study of the regulation of organ growth which lead to the conclusion that there is a certain correlation between the density of cell packing and mitotic activity in the tissue (Tumanishvili, 1964, 1965a, b; Tumanishvili & Tabidze, 1962, 1963). The density of cell packing is expressed as the concentration of nuclei (CN), reflecting not only the number of cells in a given tissue volume, but an aspect of interrelation of nuclei and cytoplasm as well. Observations have shown that an increase in mitotic activity always leads to an increase in the concentration of nuclei, and a decrease to a decrease. At the same time an increase in the concentration of nuclei appears to cause suppression of mitotic activity, while a decrease of the nuclear concentration to cause vigorous cell division.

Isolation of Human Sebaceous Glands and Cultivation of Sebaceous Gland-Derived Cells as an In Vitro Model.

1989 ◽  
Vol 93 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Longqing Xia ◽  
Christos Zouboulis ◽  
Michael Detmar ◽  
Augusto Mayer-da-Silva ◽  
Rudolf Stadler ◽  
...  
Keyword(s):  
Sebaceous Gland ◽  
In Vitro Model ◽  
Sebaceous Glands ◽  
Vitro Model

scholarly journals Lipids and the Permeability and Antimicrobial Barriers of the Skin

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Philip W. Wertz
Keyword(s):  
Fatty Acids ◽  
Stratum Corneum ◽  
Free Fatty Acids ◽  
Skin Surface ◽  
Mechanical Trauma ◽  
Permeability Barrier ◽  
Sebaceous Glands ◽  
Lipid Film ◽  
Terrestrial Vertebrates ◽  
Intercellular Lipid

The primary purpose of the epidermis of terrestrial vertebrates is to produce the stratum corneum, which serves as the interface between the organism and the environment. As such, the stratum corneum provides a permeability barrier which both limits water loss through the skin and provides a relatively tough permeability barrier. This provides for a degree of resistance to mechanical trauma and prevents or limits penetration of potentially harmful substances from the environment. The stratum corneum consists of an array of keratinized cells embedded in a lipid matrix. It is this intercellular lipid that determines the permeability of the stratum corneum. The main lipids here are ceramides, cholesterol, and fatty acids. In addition, the skin surface of mammals, including humans, is coated by a lipid film produced by sebaceous glands in the dermis and secreted through the follicles. Human sebum consists mainly of squalene, wax monoesters, and triglycerides with small proportions of cholesterol and cholesterol esters. As sebum passes through the follicles, some of the triglycerides are hydrolyzed by bacteria to liberate free fatty acids. Likewise, near the skin surface, where water becomes available, some of the ceramides are acted upon by an epithelial ceramidase to liberate sphingosine, dihydrosphingosine, and 6-hydroxysphingosine. Some of the free fatty acids, specifically lauric acid and sapienic acid, have been shown to have antibacterial, antifungal, and antiviral activity. Also, the long-chain bases have broad spectrum antibacterial activity.

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