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Biomedical subjects

F Furukawa

Publications and source records attributed to F Furukawa.

At least 307 records · Page 17Linked to original sources
PubMed1985

IgA containing circulating immune complexes and IgA anti-single stranded DNA antibodies in patients with obstructive jaundice.

Elevated levels of IgA containing circulating immune complexes (IgA-CIC) and IgG containing (IgG-) CIC were detected in patients with obstructive jaundice due to biliary tract stones and/or tumour of biliary tract or pancreas. Levels of serum IgA were also elevated, and correlated with the levels of IgA-CIC. The levels of IgA and IgG anti-single stranded (ss) DNA were elevated, and there was a significant correlation between the levels of IgA-CIC and IgA anti-ssDNA antibodies. The cause of IgA-CIC increase in patients with obstructive jaundice might be due not only to simple obstruction of biliary tract but also to other factors such as a tissue destruction.

Adult↗
PubMed1985

Abnormal stem cells in autoimmune-prone mice are responsible for premature thymic involution.

Autoimmune-prone mice show premature thymic involution, including morphological and functional abnormalities. To determine why the thymic abnormalities develop in autoimmune-prone mice, transplantation of the thymus and/or bone marrow was performed. When thymuses of newborn MRL/1 (H-2k) mice were grafted into C3H/HeN nu/nu(H-2k) mice, the engrafted thymuses did not show the abnormalities which characterize the thymus in the autoimmune-prone MRL/1 mice. By contrast, when thymuses of newborn C3H/HeN or MRL/n mice were grafted into MRL/1 mice, the engrafted thymuses developed after an interval of 3 months the same morphological abnormalities as were seen in MRL/1 mice. Thus, we can conclude that premature involution of the thymus in autoimmune-prone mice may not be a genetically determined abnormality intrinsic to the thymus, but rather an abnormality secondary to other events occurring in these mice. When bone marrow of young C3H/HeN nu/nu mice was transplanted into irradiated (850 rad) MRL/1 mice, neither thymic abnormalities nor autoimmune diseases developed. Therefore, it seem likely that abnormal stem cells in autoimmune-prone mice induce thymic abnormalities, and these, in turn, are associated with the development of autoimmune diseases.

Animals↗
PubMed1984

NaCl induced ornithine decarboxylase and DNA synthesis in rat stomach mucosa.

Inductions of 200-fold increase in ornithine decarboxylase activity within 6 hours and 9-fold increase in DNA synthesis within 3 hours in rat stomach mucosa were observed after a single oral dose of saturated NaCl solution. NaCl caused dose-dependent induction of ornithine decarboxylase activity at doses of 0.25 to 1. 5g /kg body weight, and of DNA synthesis at doses of 0. 5g to 1. 5g /kg body weight. Administration of 1,3-diaminopropane one hour before NaCl inhibited the induction of ornithine decarboxylase activity in the stomach mucosa 3 and 6 hours after NaCl administration, but a single dose of 1,3-diaminopropane itself induced ornithine decarboxylase after 16 hours.

Animals↗
PubMed1984

Dermatopathological studies on skin lesions of MRL mice.

The MRL-lpr/lpr(MRL/l) mouse is a new animal model for human systemic lupus erythematosus (SLE) and skin lesions with hair loss and scab formation are one of the characteristic manifestations in this mouse. We investigated the histopathology of the skin lesions in MRL/l mice and studied the related autoimmune phenomenon. Light microscopical observations revealed hyperkeratosis, acanthosis, hypergranulosis, liquefaction, vasodilation in the dermis and T-cell infiltration into the dermis at the age of 5 months (mo). Immunohistological studies showed the presence of immunoglobulins and/or complement depositions at the dermal-epidermal junction (DEJ). In some mice there was deposition of immunoglobulin at the DEJ at 2 mo and in 90%-100% of MRL/l mice at over 5 mo. Temporal relationship was present among cutaneous immunoglobulin depositions, the occurrence of anti-DNA antibodies and proteinuria. These findings suggest that MRL/l mice might provide a new aid for studying the biological mechanisms of the development of skin lesions in human SLE.

Age Factors↗
PubMed1984

Anti-hapten antibodies and autoantibodies in Japanese patients with lepromatous leprosy.

In the sera of patients with lepromatous leprosy anti-DNP antibodies were detected in order to determine the mode of polyclonal B-cell activation. Anti-DNP antibodies were found in 30% of the patients with active lepromatous leprosy and in 8% of those with inactive lepromatous leprosy. The level of anti-DNP antibodies in active patients was significantly higher than the level in inactive patients and control. However, the presence of anti-DNP antibodies was unrelated to the production of circulating immune complexes and antinuclear antibodies. These results suggest that polyclonal B-cell activation might occur but that the B-cell clones stimulated by M. leprae are different from patient to patient.

Adult↗
PubMed1984

Ultrastructural observations of skin lesions in MRL mice--dermoepidermal junction.

The MRL-lpr/lpr (MRL/l) mouse, a new animal model for the study of human systemic lupus erythematosus (SLE), shows characteristic skin manifestations in addition to several systemic autoimmune phenomena. The ultrastructural changes observed in the dermoepidermal junction (DEJ) and in the uppermost dermis were: infolding of the DEJ; deformities of the basal lamina--partial disappearance, thickening, hanging down, duplication, and separation from the basal cell membrane; basal laminalike dense material in the uppermost dermis and increased anchoring fibrils; particles composed of circulated half-desmosomes between the basal cells and the basal lamina, and in the uppermost dermis with or without an enclosing basal lamina; cell processes of the basal cells; and invagination of the basal lamina in the basal cells. Most of these findings were similar to the ultrastructural changes observed in the skin lesions of human SLE. The skin eruptions of MRL/l mice might be a new aid in the investigation of the pathogenesis of the skin lesions of human SLE.

Animals↗
PubMed1984

Correlative morphological and biochemical studies on monocrotaline-induced pulmonary alterations in rats.

A single s.c. injection of 60 mg/kg of monocrotaline to rats induced pulmonary alterations characterized by hyaline thrombi of capillaries and arterioles, focal necrosis of alveolar walls, and medial thickening and intimal hyalinosis of arteries. Such pathological alterations became apparent 7 days after injection and thereafter progressively developed with the passage of time. Histometrical examination revealed a reduction of the alveolar surface area in a unit volume of lung tissue in these rats. Biochemically, lung angiotensin-converting enzyme activity was estimated to have reduced in parallel with the development of pulmonary alterations while plasma angiotensin-converting enzyme activity was unchanged throughout the experimental period.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1984

Three-dimensional morphological study of rat gastric lesions induced by N-methyl-N'-nitro-N-nitrosoguanidine. Structural atypia in carcinoma and non-carcinomatous lesions.

Lesions of the rat glandular stomach induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were classified into 4 categories: intramucosal lesions; polypous lesion; downward-growth lesions, and unequivocal adenocarcinomas. Each lesion was examined by three-dimensional reconstruction from serial sections to study the spacial arrangement of the glandular tubules. In the intramucosal lesions, the tubules showed tree-like branchings. In the polypous lesions and downward-growth lesions, the tubules were interconnected to form a three-dimensional network. In unequivocal adenocarcinomas, the tubules appeared separated and were dispersed into nests. These findings indicate that interruption of continuity of the epithelium in proliferated tubules is a possible sign of malignant transformation. Erosions were always observed in the intramucosal, the polypous and the downward-growth lesions. There were locations in the tubular system where the tubules became so attenuated as to resemble cord like structures. Inflammatory reactions were always demonstrable in the intertubular spaces in such lesions. These findings indicate that MNNG-induced anatomical changes may participate in the formation of erosions by causing local obstruction of the ductules.

Adenocarcinoma↗
PubMed1984

Pathogenesis of paraquat-induced pulmonary hemorrhage in hamsters with special reference to arterial constriction.

Three dimensional reconstructions of pulmonary arteries and the bronchial tree were made to evaluate the cause of hemorrhage in the lungs of hamsters treated with a single intraperitoneal injection of paraquat at a dose of 15 mg/kg b.w. The hemorrhage corresponding to the respiratory bronchiolar segment formed the minimum hemorrhagic unit; larger hemorrhages were composed of conglomerations of such units. The respiratory bronchiolar segment was fed by a single respiratory bronchiolar arteriole which had a distinct muscular medial coat. No evidence of breakage of the arterial wall passing through the hemorrhagic lesion could be detected even by careful observation with serial histological sections. Accordingly, the cause of the lung hemorrhage was sought in the combined effects of paraquat toxicity to the capillary endothelium and vasoconstriction of the respiratory bronchiolar arterioles.

Animals↗
PubMed1984

Papuloerythroderma.

The main macroscopic features of 4 cases presented here are erythroderma-like lesions and solid papules. The former covers extensive areas over entire trunk and extremities, especially extensor surfaces. The latter is observed mainly on flexor surfaces of extremities and around the former. The axillae, inguinal regions, cubital and popliteal fossae, and big furrows on abdomen are spared from these lesions. Rashes appear first as papules and form erythroderma-like lesions through their assembly and confluence. Histologically, both show almost the same findings. Patients are older males with no general symptoms except itching. Although the course is chronic, lesions improve slowly and heal only after years.

Administration, Topical↗
PubMed1984

A comparative histometrical analysis of renal inner medulla of man, swine, dog and hamster.

Quantitative estimations of the total circumference (in mm) of Henle's thin segment (TCH) and of the collecting tubules (TCC) in the renal inner medulla of man, swine, dog and hamster were made at different distances (X) from the papillary apex. The results were expressed as exponential functions of X, the distance in mm along the medullary ray from the papillary apex to a certain point of the inner medulla, as L = AeBX. In man and swine, TCH was greater than TCC towards the external border of the inner medulla. However, in dog and hamster TCH was less than TCC along the entire inner medulla. The exponents of TCH showed nearly constant values (hamster: 0.68, dog: 0.75, man: 0.55, swine: 0.56), but those of TCC had values (hamster: 0.92, dog: 0.57, man: 0.28, swine: 0.26) correlated with the ability for concentration of urine. These findings indicate a good correlation between the ability to concentrate urine and the structure of the collecting tubules of the inner medulla, suggesting that the structure of the collecting tubules in the inner medulla affects the mechanism of urinary concentration.

Animals↗
PubMed1984

Effects of sodium chloride, saccharin, phenobarbital and aspirin on gastric carcinogenesis in rats after initiation with N-methyl-N'-nitro-N-nitrosoguanidine.

Sodium chloride, saccharin sodium, phenobarbital sodium and aspirin were tested for tumor-promoting activity in the glandular stomach of rats after initiation with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) coupled with administration of a high salt diet. Male outbred Wistar rats were given MNNG in the drinking water (100 mg/liter) for 8 weeks, and during this period they were fed on diet supplemented with 10% sodium chloride. Thereafter, they were divided into 5 groups and fed on the basal diet or one of various diets supplemented with 10% sodium chloride, 5% saccharin, 0.05% phenobarbital or 1% aspirin until the end of the experiment. All animals were killed at the 40th experimental week for necropsy and histological examination. The incidence of adenocarcinoma was increased in the group given sodium chloride following initiation by MNNG and sodium chloride as compared with the group given MNNG and sodium chloride initiation only, but not significantly. However, the incidence of preneoplastic hyperplasia was significantly increased in this group. Saccharin also enhanced the development of adenocarcinomas of the glandular stomach. The results indicated that dietary administration of sodium chloride or saccharin after MNNG tends to promote tumor development. Phenobarbital or aspirin did not enhance tumor development, aspirin in fact rather showing a tendency to decrease the tumor incidence.

Adenocarcinoma↗