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Biomedical subjects

M Isoda

Publications and source records attributed to M Isoda.

At least 19 recordsLinked to original sources
PubMed2003

Chemical peeling with salicylic acid in polyethylene glycol vehicle suppresses skin tumour development in hairless mice.

BACKGROUND: Chemical peeling with salicylic acid in polyethylene glycol (PEG) vehicle is used clinically to improve the cosmetic appearance of skin that has been damaged by exposure to the sun. It is well known that cancers of the skin such as basal cell carcinoma and squamous cell carcinoma may be induced by the sun. However, the carcinogenic potential of chemical peeling agents has not been studied. OBJECTIVES: To evaluate the effects of chemical peeling with 30% salicylic acid in PEG on skin tumour formation in treated vs. control mice. METHODS: To serve as a model of sun-damaged skin, hairless SKH/hr1 mice were irradiated with ultraviolet (UV) B for 14 weeks, with or without treatment every 2 weeks with 30% salicylic acid in PEG for a total of 18 weeks. RESULTS: Not only was the total number of tumours greatly reduced in the treated vs. the control mice, but skin tumour development was also slower in the treated vs. the control mice. At the final treatment, the fractions of T and B lymphocytes and natural killer cells from spleens of both groups of mice were comparable, and interferon-gamma production did not differ. CONCLUSIONS: Our findings suggest that chemical peeling with salicylic acid in PEG may help to prevent as well as to reduce the number of UVB-induced skin tumours.

Animals↗
PubMed2001

New formulation of chemical peeling agent: histological evaluation in sun-damaged skin model in hairless mice.

BACKGROUND: chemical peelings injure the superficial skin, which is then restored by healing of the wound. OBJECTIVES: to document the acute and chronic histological changes produced by applying chemical peeling agents used clinically to the UVB-irradiated skin of hairless mice, which served as a model of sun-damaged skin. DESIGN: three chemical peeling agents, 30% salicylic acid, dissolved in macrogol (a new formulation), 35% trichloroacetic acid (TCA) dissolved in distilled water and 20% glycolic acid dissolved in glycerin were applied to the backs of UVB-irradiated hairless mice. Untreated, irradiated areas of skin served as controls. Specimens were evaluated histologically at 3, 14, 28, and 70 days. RESULTS: chronic UVB irradiation produced an irregular hypertrophy of the epidermis. The treated areas of irradiated skin recovered by day 70. At 28 days, all skin specimens treated with chemical peeling agents exhibited a unique connective tissue layer composed of fine collagen fibers beneath the epidermis. While 35% TCA produced severe tissue damage marked by inflammation up to day 14, no inflammatory infiltrates were seen with 30% salicylic acid in macrogol at 70 days. CONCLUSIONS: chemical peeling with 30% salicylic acid dissolved in macrogol led to reorganization of the epidermis and a rebuilding of the superficial dermal connective tissue important in reducing wrinkles, and without evidence of inflammatory infiltrates in an animal model of sun-damaged skin. Findings suggest a possible clinical benefit.

Animals↗
PubMed2000

Histologic changes in the skin of hairless mice following peeling with salicylic acid.

OBJECTIVE: To clarify the histologic alterations produced by the application of salicylic acid solution, which has been used effectively in chemical peeling without producing a wound or inflammation. DESIGN: We applied 7.5%, 15.0%, and 30.0% salicylic acid in solutions of ethanol or macrogol to the backs of hairless mice for 20 minutes. The skin was histologically evaluated immediately and at 1, 3, 12, 24, and 48 hours following treatment. SETTING: The Department of Dermatology, Faculty of Medicine, Kyushu University, Fukuoka, Japan. MAIN OUTCOME MEASURES: A loss of cornified cells was the only morphologic alteration associated with the treatment, and was followed by the activation of the epidermal basal cells and the underlying fibroblasts. RESULTS: The 7.5% and 15. 0% salicylic acid solutions produced few histologic changes, whereas the 30.0% salicylic acid in both vehicles macerated and then exfoliated the cornified cells. As the epidermis became thinner, the residual epidermal cells became flattened and were rearranged parallel to the tensile surface load. The cornified material within the hair follicles also became macerated, dilated the follicles, and then dropped off. An apparent increase occurred in the number of cells in the S phase in the epidermal basal cells in 24 hours, leaving the follicular cells unchanged. As the cornified layer thickened in 48 hours, the epidermal cells below it and the underlying fibroblasts resumed their random pretherapy arrangement. Except for the occasional infiltrate of lymphocytes, no degenerative or inflammatory changes occurred. While similar changes occurred with each vehicle, they were relatively faster with the ethanol preparations. CONCLUSION: The present results suggest that the architecture of the epidermis and the papillary dermis can be regenerated by simply injuring the cornified layer by using topical agents such as salicylic acid that do not cause degeneration or inflammation.

Animals↗
PubMed2000

Response of naevus of Ota to Q-switched ruby laser treatment according to lesion colour.

Lesions of naevus of Ota range in colour from light brown to blue, and even greenish-black. To develop guidelines for optimal treatment, we evaluated the number of Q-switched ruby laser treatments required to eliminate the pigmentation of such lesions classified by colour. Over a period of 6 years, we evaluated 151 Japanese patients with naevus of Ota who had been treated with the Q-switched ruby laser at a low energy level (wavelength 694.3 nm; pulse duration 28 x 10-9 s; energy fluence 5 J/cm2; spot size 6.5 mm) every 2 months. Each lesion was classified by colour as brown (n = 22), brown-violet (n = 42), violet-blue (n = 81) and blue-green (n = 6). The 22 predominantly brown lesions attained an excellent (100-95%) or good (95-75%) cosmetic result following three laser treatments in all patients who received this number of treatments. In the 42 brown-violet lesions, 25 of the 29 good or excellent results were achieved after four treatments; the 13 less successful results were in patients who had one to three treatments. In the 81 violet-blue lesions, 54 of the 65 good or excellent results were achieved after four treatments and 64 of 65 after five treatments, whereas all 16 less good results were in patients who had only one to three treatments. However, in the six blue-green lesions, six or more treatments were required to achieve a similarly favourable result. At the end of treatment, the area was virtually free of scarring, and its texture resembled that of the surrounding normal skin. We have confirmed that the use of the Q-switched ruby laser at a low energy level can eliminate the pigmentation of naevus of Ota. While the desired improvement can be obtained within 1 year, the number of treatments appears to depend on the predominant colour of the lesion.

Adolescent↗
PubMed2000

[Monitoring of the cryptococcus count in the cerebrospinal fluid with negative cultures in two cases of serious cryptococcal meningitis].

We monitored the cryptococcus count in the cerebrospinal fluid(CSF) using the filter technique in two cases of serious cryptococcal meningitis during the course of treatment with antifungal agents. Lumbar puncture was performed once a week, and 1 ml of CSF was filtered through a Millipore filter(5.0-micron pore for cells), followed by staining of the filters with Alcian blue. All of the cryptococci on the filter were counted under a light microscope at a magnification of x 100. More than 500/ml and 2,000/ml of cryptococci were still observed in the CFS in Cases 1 and 2, respectively, in whom CFS cultures for Cryptococcus neoformans became negative after 4 weeks of treatment. Even though the treatment with antifungal agents were continued in these cases, cryptococci could still be observed for 5 weeks and 60 weeks on the filter preparations of Cases 1 and 2, respectively, after the CSF cultures became negative. The cryptococcal antigen could also be detected in the CSF during the positive filter preparations in these cases. At autopsy in Case 2, patchy lepromeningeal inflammatory lesions with the characteristic capsules of cryptococci were observed in the subarachnoid space. These observations suggest that cryptococci, which persisted in the CSF despite the negative cultures, were responsible for the lesions in the subarachnoid space and protracted clinical course in the two cases of cryptococcal meningitis.

Aged↗
PubMed1997

Role of bcl-2 in the development of lymphoid cells from the hematopoietic stem cell.

To investigate the role of bcl-2 in lymphohematopoiesis, a long-term bone marrow reconstitution system was established. Transplantation of 1,000 c-Kit+ Sca-1+ and lineage markers negative cells from bcl-2-l-mouse bone marrow resulted in long-term reconstitution of nonlymphoid cells. However, T cells were totally absent and B-lymphocyte development was severely impaired at a very early stage of differentiation in the chimeric mouse. On the other hand, transplantation of day 14 fetal liver cells from bcl-2-l-mice resulted in generation of both T and B cells in the recipient, albeit transiently. These data suggest that bcl-2 plays a critical role in the development of lymphoid progenitor cells from the hematopoietic stem cell (HSC), but is not essential for the development of nonlymphoid cells and the self-renewal of HSC. In addition, lymphopoiesis from fetal liver HSC appears to be less dependent on bcl-2 than adult bone marrow HSC.

Animals↗
PubMed1995

Molecular cloning, sequencing, and expression of the genes encoding adenosylcobalamin-dependent diol dehydrase of Klebsiella oxytoca.

The pdd genes encoding adenosylcobalamin-dependent diol dehydrase of Klebsiella oxytoca were cloned by using a synthetic oligodeoxyribonucleotide as a hybridization probe followed by measuring the enzyme activity of each clone. Five clones of Escherichia coli exhibited diol dehydrase activity. At least one of them was shown to express diol dehydrase genes under control of their own promoter. Sequence analysis of the DNA fragments found in common in the inserts of these five clones and the flanking regions revealed four open reading frames separated by 10-18 base pairs. The sequential three open reading frames from the second to the fourth (pddA, pddB, and pddC genes) encoded polypeptides of 554, 224, and 173 amino acid residues with predicted molecular weights of 60,348 (alpha), 24,113 (beta), and 19,173 (gamma), respectively. Overexpression of these three genes in E. coli produced more than 50-fold higher level of functional apodiol dehydrase than that in K. oxytoca. The recombinant enzyme was indistinguishable from the wild-type one of K. oxytoca by the criteria of polyacrylamide gel electrophoretic and immunochemical properties. It was thus concluded that these three gene products are the subunits of functional diol dehydrase. Comparisons of the deduced amino acid sequences of the three subunits with other proteins failed to reveal any apparent homology.

Amino Acid Sequence↗
PubMed1990

[Effects of heat treated cells of intestinal lactic acid bacteria in rats fed a deoxycholic acid diet].

Effects of the administration of heat treated cells of intestinal lactic acid bacteria were examined in rats fed a deoxycholic acid (DCA) diet. Male Wistar rats were given a 0.25% DCA diet with or without the heat treated cells of Enterococcus faecalis AD 1001 (EFH-1) or Lactobacillus reuteri AD 0002 (LRH-2) for 4 weeks. Abnormal increases in serum GOT, GPT, UN and lipoproteins were observed in the rats fed the DCA diet. Furthermore, severe lesions in the kidney as well as in the liver were found in these rats. On the contrary, the increases in serum GOT, UN, VLDL and LDL were significantly suppressed, and markedly fewer lesions in the liver and the kidney were observed in the rats fed the DCA diet plus EFH-1 or LRH-2.

Animal Feed↗
PubMed1988

Eosinophil chemotactic factor in tumour tissue from a patient with Kimura's disease.

An extract of tumour tissue from a patient with Kimura's disease was tested for eosinophil chemotactic activity using the Boyden chamber method. Eosinophil chemotactic activity was detected in the tissue extract, and after gel filtration maximum activity was found in the fraction with a molecular weight of approximately 1000 daltons. This factor may play a role in the tissue eosinophilia which occurs in Kimura's disease.

Adult↗
PubMed1988

Local antibody production and immune complex formation in rats experimentally infected with Angiostrongylus cantonensis.

The systemic humoral immune responses and tissue localization of worm-antigen, antibodies (IgG), and complement (C3) were examined in rats experimentally infected with Angiostrongylus cantonensis. While the worms remained in the subarachnoid space, it was infiltrated with plasma cells and lymphoid cells containing IgM and IgG. When the infiltration of these cells became more pronounced, the serum antibody titer began to increase. At the same time, deposits of IgM, IgG, and C3 were found in the glomeruli of the kidney. A number of eggs were observed in the lungs, enclosed in granulomatous tissues. Infiltrates of plasma cells including IgM and IgG, and deposits of IgM, IgG, and C3 were detected around the eggs and in the granulomatous tissues. A marked increase in serum antibody was observed. A. cantonensis larvae induce local antibody (IgM and IgG) production in the central nervous system prior to an increase of serum antibody titer. Measurement of cerebrospinal fluid antibody titer at an early stage of infection may confirm infection. The larvae showed no evidence of damage in spite of marked local antibody production in the central nervous system. The eggs in the lungs stimulated both local and systemic antibody production, and immune complexes were formed in the lung and the circulatory system. Immune complexes may participate in the formation of granuloma.

Angiostrongylus↗
PubMed1988

Neurothekeoma.

Neurothekeoma is a rare, benign cutaneous tumor with a fairly distinctive histologic appearance and characteristic clinical features. A second typical case of neurothekeoma in Japan, occurring on the dorsal aspect of the right hand, is presented.

Adult↗
PubMed1988

Metastatic adenocarcinoma. A case report demonstrating bullous pemphigoid antigen in the tumor.

A case of metastatic adenocarcinoma in the skin of the thigh with an unconfirmed origin is described. Bullous pemphigoid antigen, which is present in the normal basement zone of stratified epithelia, was haphazardly present in the basement membrane zone of the aggregated tumor cells and within the cytoplasm of some cells. This finding indicates that metastatic malignant epithelial cells may produce bullous pemphigoid antigen in the alternative environment, especially if situated in the skin.

Adenocarcinoma↗