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Biomedical subjects

H Iguchi

Publications and source records attributed to H Iguchi.

234 records · Page 13Linked to original sources
PubMed1978

Testosterone-indued focal myocarditis in rats. II. Morphological and biochemical observations of the adrenal in relation to the pathogenetical mechanism of cardiac lesions.

Correlative morphological and biochemical studies were made on the adrenal of rats treated with daily subcutaneous injections of testosterone propionate in a dose of 50 mg/kg for 30 consecutive days. Histologically, there is a thinning of the zona fasciculata with a decrease of cell numbers, swelling of the cell body and the occurrence of large lipid droplets in the cytoplasm. Electron microscopic examination revealed swelling of mitochondria with reduction of cristae and hypertrophy of smooth-surfaced endoplasmic reticulum with cluster formation or whirl-like arrangement. In in vitro biochemical experiments, it was noted that conversion of deoxycorticosterone to corticosterone or 18-hydroxydeoxy-corticosterone was decreased to 45% of the control level in the testosterone-treated group.

Adrenal Cortex↗
PubMedDate not supplied

Nitric oxide (NO) synthase activity in the lung and NO synthesis in alveolar macrophages of rats increased on exposure to asbestos.

We examined whether the lung of rats induced nitric oxide synthase (NOS) on instillation of Union Internationale Contre le Cancer (UICC) asbestos into the trachea, and whether alveolar macrophages (M phi s) of rats increased synthesis of nitric oxide (NO) on exposure to the asbestos. Instillation of chrysotile asbestos (CH) into rat tracheas increased NOS activity in the lung up to fourfold compared with that of normal control rats. On instillation of amosite asbestos (AM), the activity did not significantly increase. In the culture of alveolar M phi s with CH, NO2-, a stable oxidation product of NO, in the conditioned medium markedly increased while in the culture with AM or crocidolite (CR) asbestos it was comparable to that in the control culture without asbestos. Thus, it was assumed that the lung as well as alveolar M phi s induced NOS on exposure to CH. Viability of M phi s was lower in the culture with CH than in the culture with AM or CR. When alveolar M phi s were cultured in the presence of lipopolysaccharide (LPS), a potent inducer of NOS, NO2- in the medium dramatically increased, indicating a possible induction of NOS, while NO2- was decreased significantly in the presence of both LPS and CH, AM or CR. On the other hand, when M phi s which had previously been stimulated with LPS were cultured in LPS-free medium, NO2- synthesis retained a significantly increased level, irrespective of the presence or absence of asbestos. Thus, the three kinds of asbestos used seemed to interfere with LPS in inducing NOS and to decrease subsequently the synthesis of NO2-, but not to affect the synthesis of NO2- by LPS-induced NOS. Taken altogether, lung or alveolar M phi s of rats induced NOS to increase NO synthesis on exposure to CH.

Animals↗
PubMedDate not supplied

Lipid peroxidation and disintegration of the cell membrane structure in cultures of rat lung fibroblasts treated with asbestos.

Rat lung fibroblasts were cultured for 24 and 48 h with UICC standard reference asbestos samples of amosite, crocidolite or Canadian chrysotile at various concentrations, and thiobarbituric acid-reactive substances (TBARS) in the media and the cells were measured. Tests by the trypan blue dye-exclusion method showed that cell viability was 80 +/- 5% (mean +/- SD) and 71 +/- 6% when cultured for 48 h in the presence of 500 micrograms ml-1 of amosite and crocidolite, respectively, but was not affected by chrysotile. In cultures for 24 and 48 h, both chrysotile and crocidolite at > 250 micrograms ml-1 significantly increased TBARS in the medium, whereas amosite did so at > 500 micrograms ml-1. TBARS in the cells was not increased significantly by chrysotile at any concentration in the cultures for 24 and 48 h, but crocidolite at > 250 micrograms ml-1 significantly increased TBARS in the cells when cultured for 24 or 48 h. Although amosite at all concentrations tested did not increase significantly TBARS in the cells of the 24-h culture, it did increase TBARS significantly in the cells when cultured for 48 h at a concentration of 500 micrograms ml-1 amosite. The increases of TBARS in media of the cultures with asbestos were accompanied by increases of lactate dehydrogenase (LDH) activity in the media, indicating the leakage of the enzyme from the cell into the media. The activity of LDH and the amount of TBARS showed a good correlation with each other, with a significant correlation coefficient value of 0.655.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Treatment of a malignant stricture after esophagojejunostomy by a self-expanding metallic stent.

Gianturco self-expanding metallic stents (GSs) were placed across an esophagojejunostomy which had become strictured secondary to recurrent anastomotic gastric cancer. Placement of the GS enabled the patient to take liquid food and swallow saliva, though only for a short period of time. One month after placement, the stented lumen restrictured with a markedly irregular contour. The patient's clinical status deteriorated with eventual occlusion of the stented anastomosis. The patient died of renal insufficiency 80 days after placement of the stent. There are some questions concerning the stability of applying the Gianturco-type bare stent to the digestive tract. In the future, more suitable stents will have to be developed.

Adult↗
PubMedDate not supplied

Evidence for a novel pituitary protein (7B2) in human brain, cerebrospinal fluid and plasma: brain concentrations in controls and patients with Alzheimer's disease.

A novel pituitary protein, designated as 7B2, recently purified in our laboratory was measured using a specific radioimmunoassay in conjunction with immuno-affinity extraction, in cerebrospinal fluid (CSF) and in plasma obtained from normal volunteers. The mean concentrations of immunoreactive (IR)-7B2 were 2154 pg/ml in CSF and 29 pg/ml in plasma. Studies by SDS-poly-acrylamide gel electrophoresis revealed that both CSF IR-7B2 and plasma IR-7B2 have an apparent molecular weight of around 20,000-21,000 as previously observed in various rat tissues. IR-7B2 was also measured in various brain regions obtained from control subjects and patients with Alzheimer's disease. IR-7B2 was widely distributed in the human brain, with the highest concentrations in substantia nigra and caudate. IR-7B2 brain concentrations were found to be similar between control subjects and patients with Alzheimer's disease. Gel permeation chromatography of extracts of various brain regions revealed two major peaks with apparent molecular weights of 45,000-50,000 and 11,000-16,000 in hypothalamus, caudate, frontal cortex, hippocampus, putamen and locus coeruleus, and only one peak with an apparent molecular weight of 14,000-16,000 in substantia nigra and globus pallidus. These data suggest that this novel pituitary protein may play a role of consequence perhaps as a neurotransmitter or as a neuromodulator in the human central nervous system.

Adult↗
PubMedDate not supplied

Renin-producing hepatoblastoma.

Renin-producing tumors of extrarenal origin are rare in children. An 8-year-old boy with hepatoblastoma and hypertension associated with a high plasma renin level is reported. After chemotherapy, the plasma renin level normalized and the hypertension spontaneously resolved. The patient underwent surgery, and a right trisegmentectomy of the liver and a partial resection of the second and third segments were performed. The tumor was as shown the source of renin by immunohistochemical study and reverse transcriptase-polymerase chain reaction.

Child↗
PubMedDate not supplied

Interleukin 8 can affect inner ear function.

The chemokine interleukin 8 (IL-8) was instilled into the round window niche of rats through a small perforation in the tympanic membrane in order to study its effect on inner ear function by electrophysiological and morphological techniques. The frequency-specific auditory brainstem response (ABR) was recorded at the frequencies 4, 8, 10, 12, 16 and 20 kHz just before and 1, 2, 5 and 14 days after instilling IL-8 to ascertain the hearing level during each interval. Morphological examination by light microscopy was performed during the same interval following the instillation of IL-8. On day 1, the rise in ABR threshold was within 5 dB SPL (non-significant elevation). However, a significant threshold elevation (above 5 dB SPL) occurred in high-frequency areas (16 and 20 kHz) on day 2, and in middle frequency areas (10 and 12 kHz) on day 5 with sensorineural hearing loss type intensity-latency curves. By day 14, the elevated thresholds had returned to pre-instillation levels. In the lowest areas (4 and 8 kHz), no significant threshold elevation was detected at any time during the observation period. By light microscopy, on day 1, clusters of inflammatory cells (predominantly neutrophils) were observed just outside the round window membrane (RWM), while only a few neutrophils were detected in the cochlea. These cells were still present outside the RWM on day 2. The neutrophils had disappeared by day 5 and only macrophages were present on the middle ear side of the RWM. However, throughout the observation period, the organ of Corti and stria vascularis appeared to be intact. These results suggest that IL-8 in the middle ear cavity is able to influence inner ear function.

Animals↗
PubMedDate not supplied

Epithelial-myoepithelial carcinoma: An unusual tumor of the paranasal sinus.

A 65-year old woman presented with nasal obstruction and on examination was found to have a huge mass in the maxillary sinus. This was removed, and histological examination revealed a mixture of trabecular structures consisting of inner dark cells, outer clear cells and solid structures consisting of only clear cells. Immunohistochemical examination showed the clear cells to be positive for alpha-smooth muscle actin. Ultrastructural examination confirmed the myoepithelial cell origin. The characteristic morphological, immunohistochemical and ultrastructural features aided in the diagnosis of epithelial-myoepithelial carcinoma.

Aged↗
PubMedDate not supplied

Temporal bone pathology of a patient with cochlear implant.

A 66-year-old man with profound total deafness received a 22-channel cochlear implant. After surgery, his hearing improved and the postoperative course was uneventful except transient vertigo. The patient died of lung cancer after 2.5 years. Twelve hours after death, the temporal bone was harvested for histological and electron microscopic examination. The mastoid air cells were preserved, although a few mucosal folds were present. The Dacron mesh tie had largely been absorbed, but part remained embedded in fibrous tissue. No inflammation was noted in the tympanic cavity or the round window through which the electrodes were inserted. In the cochlea, the scala tympani was filled with fibrous tissue at the site of electrode insertion. The scala media had collapsed, while the organ of Corti and stria vascularis showed degeneration. Osseous spiral bundles and spiral ganglion cells were noted, though reduced in number.

Aged↗
PubMedDate not supplied

Thyrotropin releasing hormone (TRH)-induced release of 7B2 (neuroendocrine polypeptide) in vivo and in vitro using adenoma cells of a patient with acromegaly.

We demonstrated TRH-induced release of 7B2 (a neuroendocrine polypeptide) in vivo and in vitro (somatotroph adenoma cells) in a patient with acromegaly. The mean basal plasma 7B2 and growth hormone (GH) levels before operation were 142.8 +/- 3.2 ng/l and 52.4 +/- 1.6 micrograms/l (mean +/- SEM), respectively and these levels significantly rose after an i.v. administration of 500 micrograms of thyrotropin releasing hormone (TRH). After the transsphenoidal adenomectomy, the basal level of plasma GH was restored to the normal level and that of plasma 7B2 was slightly decreased. In addition, TRH-induced response of plasma 7B2 and GH disappeared post-operatively. In a primary culture of somatotroph adenoma cells obtained at surgery, TRH significantly induced secretions of both 7B2 and GH. Immunohistochemical studies showed the positive 7B2 and GH immunoreactivities in somatotroph adenoma cells. These findings strongly suggest that the somatotroph adenoma cells in this case produced and released 7B2 concomitant with GH.

Acromegaly↗
PubMedDate not supplied

Clinical evaluation of assistant diagnostic system for mammograms using the auto-analyzing method.

Clinical usefulness of a newly developed auto-analyzing system of mammograms to search the abnormal dense areas such as cancer lesions was studied. 345 breasts including 86 cancers, 52 mastopathies, 18 fibroadenomas, 13 cysts, 4 lipomas and 172 normals were analyzed and compared with final diagnosis. 84 of 86 cancer lesions were correctly pointed out (sensitivity: 97.9%). Based on the gradient of the density, the ranking of the cancer or calcified lesions among suspected regions in a mammogram was decided. 55 lesions of them (64.0%) were ordered at the first rank and 83 (96.5%) were in the upper three ranks. 68 of 74 breasts with calcifications were correctly diagnosed and 48 of them were ranked in the upper three ranks. Although further improvement of the system is needed, this system will be a useful assistance for screening the breast cancer in the analyses of mammograms.

Breast Neoplasms↗