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Results for “Human dermal fibroblasts”

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At least 55 records · Page 3Linked to original sources
PubMed1979

[Ultrastructural study in four cases of cutaneous xanthomas in children (author's transl)].

Three cases are associated with a Reclinghausen disease. Histological findings show typical xanthoma. Electron microscopical study indicates: --numerous intracytoplasmic lipid inclusions of various type (droplets, crystals, concentric lamellar bodies, ceroid granules) in dermal cells (histiocytic foam cells, endothelial cells, Schwann cells, fibroblasts and most cells); --large intranuclear inclusions in some histiocytes containing few lipids droplets; these figures could be compared to a slice of "petrified wood"; their significance is as yet unknown (Liesegang rings?).

Cell Nucleus↗
PubMed2026

Generation of a hiPSC from a patient with an ITSN1-associated neurodevelopmental disorder spectrum carrying biallelic c.2893_2894insA (p.Tyr965Ter) genetic variant.

De novo truncating variants in ITSN1 are implicated in neurodevelopment disorders spectrum, however, biallelic variants in ITSN1 have not been previously identified. Here we present a hiPSC line generated from a patient dermal fibroblast carrying biallelic variant, c.2893_2894insA (p.Tyr965Ter). The hiPSC line expresses core stemness markers, mycoplasma free with normal karyotype and demonstrate trilineage differentiation capacity. The hiPSC line provides a valuable in-vitro model system to investigate its role in early brain development and neurodevelopmental disorders.

Humans↗
PubMed1978

A convenient method of establishing permanent lines of xeroderma pigmentosum cells.

Nine lymphoblastoid cell lines were established after transformation by Epstein-Barr virus of peripheral lymphocytes from four xeroderma pigmentosum (XP) patients, the parents of one XP patient, and three normal donors. All these cell lines proliferate as suspension in Roswell Park Memorial Institute Medium 1640 supplemented with 20% fetal bovine serum, without detectable release of infectious Epstein-Barr virus. Some characteristics of these cell lines, such as growth rates, chromosome numbers, UV sensitivities, and activities of unscheduled DNA syntheses induced by UV, 4-nitroquinoline 1-oxide, and N-methyl-N'-nitro-N-nitrosoguanidine, were determined. Results confirm that the properties related to XP are not altered by transformation with Epstein-Barr virus and are the same in degrees of defect as are those of dermal fibroblasts from the respective individuals. These XP and normal lymphoblastoid cell lines should be especially useful for biochemical studies on the mechanism of DNA repair, because they are easy to grow in mass culture.

Autoradiography↗
PubMed1978

Actinic elastosis in black skin. A light- and electronmicroscopic study.

In 9 otherwise dermatologically normal South African Balck volunteers (1--72 years old), sunlight-exposed and non-exposed skin has been examined by light- and electronmicroscopy with special references to age-dependent and actinic alteration of dermal structures. Two 72 year old Blacks exhibited typical dermal elastosis: in 1 case to a marked extent and already detectable by lightmicroscopy, in the other case only to a mild degree. In contrast, only age-related elastic fibers were revealed in the lower dermis of sunlight-exposed skin and in all dermal layers of unexposed skin. These observations are contradictory to the general view that actinic elastosis does not occur in Blacks. The elastotic material is obviously a de-novo synthesized and secreted pathological product of chronically UV-altered fibroblasts.

Adolescent↗
PubMed1976

[Structural and biochemical alterations of human diabetic dermis studied by H-lysine incorporation and microscopy].

The alteration of the structural organization of dermal connective tissue was studied by light and electron microscopy and by biochemical techniques in normal human and in diabetic patients using skin biopsies. Part of the tissue was used for light and electron microscopy, the rest was incubated in the presence of 3H-lysine for four hours. The 3H-lysine labelled biopsies were submitted to a sequential extraction procedure in order to obtain representative macromolecular fractions containing the matrix macromolecules. The extracts were analyzed for their chemical composition and radioactivity. Electron microscopy revealed ultrastructural modifications of the fibroblasts, of the collagen and elastic fibers in the diabetic dermis. Fibroblasts contained an increased amount of electron dense deposits in the cytoplasm and dilated endoplasmic reticulum. The collagen bundles were dissociated. Elastic fibers under the epithelial basal laminae were fragmented or absent. The incorporation pattern of 3H-lysine into these macromolecular fractions was different in the normal and diabetic skin biopsies. The percentage of total radioactivity incorporated increased significantly in the 1M CaCl2 extractable fraction an in the 6M urea extractable fraction and decreased significantly in the collagenase and elastase extracts in diabetic skin biopsy. These results demonstrate the existence of morphological and biochemical alterations in diabetic connective tissue (dermis) reflecting alterations in the relative rates of synthesis and/or degradation of the intercellular matrix macromolecules as well as of their microarchitectural arrangement.

Adolescent↗
PubMed1979

Quantitative assay of types I and III collagen synthesized by keloid biopsyes and fibroblasts.

Molecular sieve column chromatography was used to determine the amount of type I and III collagen synthesized by normal dermis and keloid biopsies and fibroblasts derived from these tissues. After incubation with radioactive proline, the collagen was extracted and separated into types I and III and then quantitated. There was no significant difference in the percent type III collagen synthesized by fresh keloid biopsies compared to normal dermis. Likewise, there was no significant difference in the percent type III collagen synthesized by keloid fibroblasts compared to normal dermal fibroblasts. However, fibroblasts from both keloid and normal dermis synthesized a lower percentage of type III collagen in cell culture compared to the original biopsies. These findings demonstrate that keloid collagen has the same type distribution as normal dermis and suggest that increased collagen synthesis in these lesions is not related to altered collagen types.

Adolescent↗
PubMed1976

The culture of skin. A review of theories and experimental methods.

Two main criticisms can be leveled against the standard methods of skin culture: they are poorly quantifiable and the cultured cell populations are heterogeneous. A new technique based mainly on enzymatic dissociation allows specific cell types to be extracted from the skin before cultivation. In this way, separate cultures of epidermal keratinocytes and dermal fibroblasts can be obtained from the same piece of skin. These purified systems have been used to study the kinetics of epidermal cell growth and to quantify the effect of various chemically defined substances on the growth and differentiation of keratinocytes. With further refinements in technique, purified populations of melanocytes can be extracted. The co-culture of pigmented melanocytes with albino keratinocytes has been proposed as a model to study pigment donation in vitro. The usual organ culture technique, including the use of large explants of skin immersed in the culture fluid, has been modified to show that adult human skin partially regenerates in vitro and that mitotic activity goes on for months in the regenerated epidermis. The use of nucleic acid hybridization techniques, combined with skin cell cultures from human tumors, opens new avenues of research on human cancer.

Amino Acids↗
PubMed1979

[Synthesis of elastoidic fibers in the organ culture of human dermis (author's transl)].

Organ cultures of human dermal excisions placed on the chorioallantoic membrane (CAM) of incubated chick eggs showed that a elastoidic fiber type could be achieved under experimental conditions within 5 h. The stages leading up to fiber formation could very well be produced by fibrocytes as well as by the splitting of collagen fibrils. The microfibrils (lacking a periodicity and with a diameter of 60-100 A) are characterized by a strong capacity to bind carbohydrate-proteinrich complexes (proteoglycans and glycoproteins). These then aggregate to elastoidic fibers. The amorphous fiber center remains strongly attractive for binding cations. This fiber type is then compared to the (elastoidic) fibers present in senile Elastosis and Pseudoxanthoma elasticum. Finally, the possibility of using CAM-cultures as experimental means for simulating such diseases is discussed.

Animals↗
PubMed1975

Induction by alkylating agents of sister chromatid exchanges and chromatid breaks in Fanconi's anemia.

Sister chromatid exchanges, which may reflect chromosome repair in response to certain types of DNA damage, provide a means of investigating the increased chromosome fragility characteristic of Fanconi's anemia. By a recently developed technique using 33258 Hoechst and 5-bromodeoxyuridine, it was observed that the baseline frequency of sister chromatid exchanges in phytohemagglutinin-stimulated lymphocytes from four males with Fanconi's anemia differed little from that of normal lymphocytes. However, addition of the bifunctional alkylating agent mitomycin C (0.01 or 0.03 mug/ml) to the Fanconi's anemia cells during culture induces less than half of the increase in exchanges found in identically treated normal lymphocytes. This reduced increment in exchanges in accompanied by a partial suppression of mitosis and a marked increase in chromatid breaks and rearrangements. Many of these events occur at sites of incomplete chromatid interchange. The increase in sister chromatid exchanges induced in Fanconi's anemia lymphocytes by the monofunctional alkylating agent ethylmethane sulfonate (0.25 mg/ml) was slightly less than that in normal cells. Lymphocytes from two sets of parents of the patients with Fanconi's anemia exhibited a normal response to alkylating agents, while dermal fibroblasts from two different patients with Fanconi's anemia reacted to mitomycin C with an increase in chromatid breaks, but a nearly normal increment of sister chromatid exchanges. The results suggest that chromosomal breaks and rearrangements in Fanconi's anemia lymphocytes may result from a defect in a form of repair of DNA damage.

Alkylating Agents↗
PubMed1977

Porphyria cutanea tarda-like dermatosis by hemodialysis. Ultrastructural study of exposed skin.

The authors studied by electron microscope, the sun-exposed skin of the back of the hand from three heavily hemodialysed patients with a porphyria cutanea tarda-like bullous skin disease. The vascular impairment, like that of PCT, closely resembles that seen during medicamentous phototoxic processes. The connective tissue is infiltrated by large granulo-filamentous masses and the fibroblasts are secretory in appearance. At the dermal-epidermal junction, the abnormalities are important, with a diffuse infiltration of the upper dermis by a hyalin substance, probably resulting in a collagen degeneration and cellular necrosis. The aetiological factors are uncertain, as no common medicamentous factor appeared in our patients, and as the plasticizers used in the hemodialysis tubes probably played no part.

Adult↗
PubMedDate not supplied

[Skin fibrosis in hyperthyroidism treated by sotalol and radioactive iodine (author's transl)].

The authors present detailed data about skin fibrosis appearing in hyperthyroidism treated by Sotalol and radioactive iodine. Cutaneous thickening is discovered quite rapidly when the patient is monitored daily (as in case 4). It is asymptomatic and no other features of scleroderma are found. Regression occurs within 4-10 months. Histologically, fibrosis is located in the entire dermis. Dermal appendages are normal and no inflammatory changes occur. No anomalies of collagen structure and fibroblasts have been observed ultrastructurally. Immunological studies (direct immunofluorescence of the skin, lymphocyte transformation and leucocyte migration tests with Sotalol) were normal. The mechanism is unknown, but an immunological or a toxic one is excluded; however a pharmacological action is possible. The role of other betablockers must be assessed by a randomised study.

Epidermis↗
PubMed1975

Variability of dermal elastin visualized ultrastructurally with iron hematoxylin.

The Verhoeff iron hematoxylin-lead citrate (VIH-LC) method demonstrated vertical elastic fibers that were often composed only of microfibrillar component extending into the epidermal basement membrane in human skin. These fibers connected with a network of trabeculae composed of microfibrils and elastin fibrils in varying proportions. The large elastic fibers in the deep two thirds of the dermis consited mainly of compact bundles of small elstin fibrils in infants and of solid elastin cores with a fimbriated periphery in adults; Dermis of a 6-month-old fetus contained very few small elastic fibrils except around blood vessels. Skin of an elderly subject revealed exteme proliferation of unusual reticulated elastic fibers in various areas and disclosed abnormal nodules of elastin or collagen fibrils in finely particulate matter. Small elastin fibrils, abundant microfibrils, and intermixed individual collagen fibrils comprised an adventitial collar between sweat glands and fibroblasts. Elastin fibrils were absent from this collar in the fetus and increased with the subject's age. A permanganate-high iron diamine sequence appeared to impart density to the microfibrillar component of elastic fibers.

Adolescent↗
PubMed1978

Inherited systemic amyloidosis (Finnish type): ultrastructure of the skin.

Ultrastructural study of skin biopsies from two patients suffering from inherited systemic amyloidosis (Finnish type) showed amyloid deposits between epidermal basal cells and dermal fibroblasts. Amyloid was seen on the epithelial side of the fibroblasts, and material resembling basal laminae was embedded in the aggregates of amyloid. Also amyloid deposits were found adjacent to other cells with a basal lamina such as epithelial cells of the sweat glands or sebaceous glands, Schwann cells, capillary endothelial cells, and even smooth muscle cells in the dermis. Amyloidogenetic interaction of cells with a basal lamina and fibroblasts is suggested and the potential role of structural glycoproteins in the genesis of amyloid is discussed.

Adult↗
PubMedDate not supplied

Connective tissue synthesis by cultured scleroderma fibroblasts. I. In vitro collagen synthesis by normal and scleroderma dermal fibroblasts.

The authors have been unable to demonstrate an increase in collagen synthesis by fibroblasts isolated from sclerodermatous skin. In order to elucidate this problem further, scleroderma fibroblasts were biopsied from upper dermis, from lower (including subcutaneous) dermis, and from adjacent clinically noninvolved skin. All cell lines failed to show a significant increase in collagen synthesis when they were compared to control fibroblast lines. One difference among them was that fibroblasts from involved areas showed a rate of collagen synthesis equal to or less than cells isolated from adjacent clinically noninvolved sites.

Adolescent↗
PubMed1975

A retarded rate of DNA chain growth in Bloom's syndrome.

The cytogenetic observation that homologous chromatid interchange occurs in Bloom's syndrome more often than normal prompted an investigation of DNA replication in that rare genetic disorder. Using DNA fiber autoradiography, an estimation was made of the rate of one component of ongoing DNA replication, DNA chain growth. The rate in Bloom's syndrome dermal fibroblasts in tissue culture was found to be significantly slower than that in normal control cells. (The rate was found to be normal in Fanconi's anemia cells.) The explanation for the retarded chain growth may be either that an enzyme concerned directly with semiconservative DNA replication is defective or that a defective enzyme not itself concerned directly with replication results in disturbed cellular metabolism which in turn affects replication.

Abnormalities, Multiple↗
PubMed1977

Cell proliferation in the Lichen planus infiltrate. Investigations by light- and electron-microscopic autoradiography.

In seven patients suffering from lichen planus (LP) light- and electron-microscopic 3H-thymidine (3HT) labeling studies were performed and the following results were obtained. 1. Using the light-microscope, a large number of 3HT labeled cells can be observed in the dermal infiltrate of LP. Most of the labeled nuclei belong to mononuclear, 'round cells' while isolated endothelial cells, fibroblasts, histiocytes and mast cells could be found labeled. 2. The mean labeling index of 'round cells' in our patients was 4.27 +/- 1.57%. 3. The evaluation of the electron microscopic autoradiographs showed that, as far as 'round' cells were concerned, exclusively nuclei of cells showing the morphological criteria of stimulated lymphocytes were labeled. These findings support the view that in LP, as in allergic contact dermatitis, a high proliferative activity of lymphocytes takes place.

Autoradiography↗
PubMed1975

The Morquio syndrome (mucopolysaccharidosis IV): Morphologic and biochemical studies.

The Morquio syndrome (mucopolysaccharidosis IV) is a lysosomal storage disease characterized clinically by dwarfism, corneal opacities, dental abnormalities, cardiopulmonary complications, normal intelligence, dysostosis multiplex with universal platyspondyly, and excessive urinary excretion of keratosulfate. The purpose of this communication is to report morphologic observations of Morquio skin and cartilage, and biochemical studies of cultured fibroblasts and cartilage-derived cells. Cells of the basal and Malpighian layers of the epidermis contain large single-membrane-bound vacuoles whereas other dermal cells types are normal. Chondrocytes are packed with similar vacuoles. Preliminary studies of mucopolysaccharide (MPS) metabolism of cultured Morquio cartilage-derived cells and fibroblasts reveals excessive intracellular MPS accumulation in cartilage-derived cells but only modest accumulations in fibroblasts. The Morquio syndrome appears to be a cell-type specific MPS storage disorder, and further studies to elucidate the presumed deficiency of lysosomal hydrolase(s) should be directed at tissues displaying both morphologic and metabolic abnormalities.

Adolescent↗
PubMed1976

Clinical and biochemical expression of a unique mucopolysaccharidosis.

A boy who presented with painful joints leading to contractures was found to have a mucopolysaccharidosis not previously described. He had severe dysostosis multiplex of the long bones but nearly normal intellectual development and no involvement of the cornea. Lysosomal storage vacuoles were noted in dermal endothelial cells; these were similar to those seen in the genetic mucopolysaccharidoses. Mucopolysacchariduria was not excessive in amount but it was distinctly abnormal in pattern and his excretion of dermatan sulfate resembled that found in the Hunter and Hurler syndromes. The activities of the lysosomal hydrolases in cultured fibroblasts were normal or increased. The degradation of accumulated 35S-mucopolysaccharide in fibroblasts in culture was typical of a mucopolysaccharidosis. His mother accumulated 35S-mucopolysaccharides in fibroblasts, suggesting an X-linked inheritance of the disorder.

Child↗