Morphologic study of tissue basophils of the skin in rats after acute local irradiation

A comparative morphological study was made of tissue basophils (TB) of rat skin at remote times (40, 70, 140, and 360 days) following single local exposure to soft and hard X-radiation with the doses at the skin surface of 15, 20, and 30 Gy. The TB response was maximum in the subepidermal and supramuscular layers of friable connective tissue. Changes in a median TB diameter were of a phase nature and a function of radiation dose absorbed in the skin layers under study.     

人皮肤成纤维细胞在紫外线B照射后的TGF—β和HSP70表达

目的和方法：采用人体皮肤成纤维细胞,观察了紫外线照射后细胞TGF－β表达与HSP70表达水平的相关性。结果：①经不同剂量的紫外线B照射后,TGF－βmRNA表达与HSP70表达水平呈正相关（r=0.906);②应用抗TGF－βⅡ型受体抗体后,在紫外线B照射后细胞培养上清液中的TGF－β含量与细胞HSP70表达水平呈负相关（r=-0.995)。结论：在紫外线B照射诱导人皮肤成纤维细胞表达HSP70的反应过程另TGF－β参与其信号转导。     

Radioautographic study of a culture of fibroblasts after irradiation by a neodymium laser]

By means of radioautographic method, with 3H-thymidin application there were studied: mitotic activity, the number of DNA-synthesizing cells, growth fraction and population number of fibroblast culture irradiated with a single impulse of neodymium laser at energy density within 1 Dg/cm2--100 Dg/cm2. Under the influence of small doses of laser radiation (1--10 Dg/cm2) the number of dividing DNA-synthesizing cells increased, together with proliferative pool and the number of cells in the field of vision. At energy density of laser radiation equal to 50 Dg/cm2, and especially to 100 Dg/cm2 despite increased mitotic index and labelled cells index, registered during first hours of the effect, proliferative pool decreased and population growth rate lowered. These doses of laser radiation produced destruction of a rather large part of the cells in a monolayer.     

Cytogenetic study of a case of Fanconi's syndrome with a familial pericentric inversion]

The cytogenetic study of a case of Fanconi syndrome in a 16-year-old boy revealed besides chromosomal breakages, quadriradials and dicentric chromosomes, a pericentric inversion of chromosome No. 1. An uncle and an aunt on the paternal side presented likewise this pericentric inversion, however without breakages or clinical signs of Fanconi syndrome. Another paternal aunt showed short thumbs, but without chromosomal anomalies. The authors point to possible genetic repercussions of this familial pericentric inversion.     

Cytogenetic investigations in a new case of Bloom's syndrome

Summary Cytogenetic studies of an 8-year-old caucasian girl with typical but mild manifestation of Bloom's syndrome showed a characteristic increase of homologous chromatid translocations and prematurely condensed chromosomes. The average frequency of sister chromatid exchanges (SCE) in lymphocytes with 133 was much higher than in skin fibroblasts with 49. The inter- and intrachromosomal distributions of SCE in lymphocytes were analyzed.Prof. Dr. H.-R. Wiedemann to his 60th birthday.     

Cultured human skin fibroblasts: a model for the study of androgen action

Human skin may be considered as a target organ for androgens, as are male sex accessory organs, since all events involved in testosterone action have been observed in this tissue. As a corollary, the mechanism of androgen action can be studiedin vitro in cultured skin fibroblasts. The advantages of this system are that studies can be performed with intact human cells under carefully controlled conditions, differentiated genetic and biochemical characteristics of the cells are faithfully preserved and the biological material is renewable from a single biopsy specimen. The metabolism of androgens, in particular the 5α-reduction of testosterone to the active metabolite, dihydrotestosterone, the intracellular binding of androgen to its specific receptor protein and its subsequent translocation to the nucleus have been studied in skin fibroblasts. The intracellular androgen receptor content of genital skin fibroblasts is higher than that from nongenital skin sites. In addition, the androgen receptor has been characterized as a specific macromolecule with properties of high affinity and low capacity similar to that of other steroid hormone receptors. The pathophysiology of three genetic mutations which alter normal male sexual development and differentiation has been identified in the human skin fibroblast system. In 5α-reductase deficiency, an autosomal recessive disorder in which dihydrotestosterone formation is impaired, virilization of the Wolffian ducts is normal but the external genitalia and urogenital sinus derivatives are female in character. At least two types of X-linked disorders of the androgen receptor exist such that the actions of both testosterone and dihydrotestosterone are impaired and developmental abnormalities may involve both Wolffian derivatives and the external genitalia as well. These two forms of androgen insensitivity result from either the absence of androgen receptor binding activity (receptor(−)form) or apparently normal androgen receptor binding with absence of an appropriate biological response (receptor (+) form). In addition, studies with human skin fibroblasts may also be of value in defining the cellular mechanisms underlying the broad spectrum of partial defects in virilization. In summary, we have correlated our studies of the molecular mechanism of androgen action in human genital skin fibroblasts with those of other investigators as these studies contribute to our understanding of male sexual development and differentiation.     

Cytogenetic results of irradiation of Southern Ural residents

The paper summarizes the results of studies of 85 individuals exposed in the Southern Ural region. The spontaneous frequency of the cells with micronuclei (MN) in a population of human blood lymphocytes after PHA stimulation and cytokinetic block with cytochalasin B has been determined. The sensitivity of lymphocytes to the irradiation at the dose of 1.0 Gy and the adaptive response (AR) after the irradiation at the low adaptive dose of 0.05 Gy, and the challenge dose of 1.0 Gy 5 h later have been studied too. It was shown that the peculiarity of the Urals population consists in a higher individual variability of the frequency of cells with MN in all groups have been investigated (spontaneous, after acute irradiation in the dose 1.0 Gy) in comparison with Moscow people. The proportion of persons with a significant AR in the Urals groups was considerably lower than that identified among Moscow residents, and the number of persons with enhanced radiosensitivity increased following low-dose irradiation. We can suppose that prolonged action of low level radiation with another ecological factors, living in the contaminated regions result in the enhancement of the sensitivity to the genotoxic agents in the separate individuals.     

Cytogenetic study of the bone marrow and peripheral blood lymphocytes in monkeys in long-term gamma irradiation

A comparative study of chromosome structures of bone marrow and peripheral blood cells has been carried out in 8 rhesus macaques (2-7 years of age), 4 of which survived after prolonged low-capacity (3.87 microA/kg) gamma irradiation, the total dose being 7.97 Gy (LD50/60). It has been established that prolonged low-capacity gamma irradiation was of a high mutagenic activity. Various tissues of irradiated monkeys showed differences in the frequency (4 months) and types (4-33 months) of aberrations within the period of 4 to 33 months following irradiation. Mutagenic effect characteristic of the early period after the irradiation was retained in the peripheral blood of irradiated monkeys within the period of observation.     

Transformation/neodifferentiation of human skin fibroblasts by acute oncornaviruses and dexamethasone

We demonstrated that the Kirsten murine sarcoma virus (KiMSV) and the Harvey murine sarcoma virus (HaMSV) converted human skin fibroblasts (HSF) into adipocytes. Adipocytic conversion of HSF by KiMSV and HaMSV was dependent on the presence of glucocorticosteroids. The Kirsten murine leukemia virus, the Harvey murine sarcoma [corrected] virus and the amphotropic helper virus (AP292) were ineffective by themselves. Balb murine sarcoma virus and Moloney murine sarcoma virus were, to a lesser degree, able to effect adipocytic conversion of HSF. In contrast, the feline sarcoma virus and the simian sarcoma virus did not cause this conversion. Together, the results suggest a role for certain oncogenes and glucocorticosteroids in the transformation/neodifferentiation of human cells.     

Cytogenetic analysis of a rare case of pediatric myxolipoma

A cytogenetic analysis was performed in a rare case of big toe myxolipoma derived from a 3-year-old girl. We found in all metaphases analyzed a trisomy 19 and a tetrasomy 1q. The breakpoints of chromosomes 1 were localized in the region p12-p13. None of the chromosome abnormalities usually described in lipomas, were observed.     

Cytogenetic patterns in acute nonlymphocytic leukemia.

Analysis of chromosomal banding patterns in acute nonlymphocytic leukemia (ANLL) reveals that approximately 50% of patients have an abnormal karyotype. Although there is substantial variability, certain nonrandom abnormalities occur, e.g., +8, -7, and the 8;21 translocation (often accompanied by loss of an X or Y chromosome). The 15;17 translocation appears to be highly specific for acute promyelocytic leukemia. These abnormalities usually are not seen in remission, but reappear in relapse, sometimes exhibiting further clonal evolution; a +8 is the most frequently observed evolutionary change. Patients with ANLL following treatment of a malignant lymphoma tend to have hypodiploid modal numbers and frequently show loss of a chromosome No. 5 or No. 7.     

Hyaluronidase expression in human skin fibroblasts

Hyaluronidase activity has been detected for the first time in normal human dermal fibroblasts (HS27), as well as in fetal fibroblasts (FF24) and fibrosarcoma cells (HT1080). Enzymatic activity was secreted predominantly into the culture media, with minor amounts of activity associated with the cell layer. In both classes of fibroblasts, hyaluronidase expression was confluence-dependent, with highest levels of activity occurring in quiescent, post-confluent cells. However, in the fibrosarcoma cell cultures, expression was independent of cell density. The enzyme had a pH optimum of 3.7 and on hyaluronan substrate gel zymography, activity occurred as a single band corresponding to an approximate molecular size of 57 kDa. The enzyme could be immunoprecipitated in its entirety using monoclonal antibodies raised against Hyal-1, human plasma hyaluronidase. PCR confirmed that fibroblast hyaluronidase was identical to Hyal-1. The conclusion by previous investigators using earlier technologies that fibroblasts do not contain hyaluronidase activity should be reevaluated.