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Biomedical subjects

H Iguchi

Publications and source records attributed to H Iguchi.

At least 73 records · Page 4Linked to original sources
PubMed1997

Nitric oxide synthase and contractile protein in the rat cochlear lateral wall: possible role of nitric oxide in regulation of strial blood flow.

The present study demonstrated by histochemical and immunohistochemical methods that NADPH diaphorase reactivity, endothelial nitric oxide synthase (eNOS)-like immunoreactivity, and tropomyosin-like immunoreactivity, were located within the rat cochlear lateral wall. Both NADPH diaphorase reactivity and eNOS-like immunoreactivity were found mainly in the endothelium of the strial capillaries (ESC) and that of the vessels of the spiral ligament (ESL). These reaction products appeared to be somewhat more common in the ESC than in the ESL. On the other hand, tropomyosin-like immunoreactivity was localized in tissues outside the endothelium and its intensity was greater in the ESL than in the ESC. These findings suggest that nitric oxide (NO) produced by eNOS may play a role in regulating the blood flow of the cochlear lateral wall. In addition, NADPH diaphorase reactivity, eNOS-like immunoreactivity, and tropomyosin-like immunoreactivity showed different patterns of distribution between ESC and ESL. This suggests that in these two sites blood circulation is controlled by NO through two different mechanisms that are suitable for regulating strial blood flow.

Animals↗
PubMed1997

Triggers of hair cell regeneration in the avian inner ear.

We performed an in vitro study in order to determine possible triggers of hair cell regeneration in the chick basilar papilla following degeneration. We compared the response of sensory epithelium damaged by collagenase treatment with that damaged by acoustic trauma. The former exhibited no proliferative activity, but the latter did. The basilar papillae damaged by acoustic trauma could have proliferating activity in medium containing fetal bovine serum (FBS) or epidermal growth factor (EGF) but not in the medium without FBS or EGF. These findings indicate that regeneration of basilar papillae depends on the manner of cell death and that FBS or EGF is required for regeneration.

Animals↗
PubMed1997

Interactions between vitamin C and vitamin E are observed in tissues of inherently scorbutic rats.

To investigate in vivo interactions between antioxidant vitamins C and E, sparing effects of vitamin C on vitamin E as well as those of vitamin E on vitamin C were evaluated using inherently scorbutic [Osteogenic Disorder Shionogi (ODS)] rats. Rats were divided into four groups (control, vitamin E-deficient, vitamin C-deficient and simultaneously vitamins C and E-deficient). The levels of vitamins C and E in tissues were determined at 0, 14 and 21 d of deficiency. On d 14, the vitamin E concentration in plasma, liver, brain and lung of the vitamin C-deficient group was significantly lower than that of the control, in agreement with the literature concerning the sparing of vitamin E by ascorbate. The vitamin E concentration of the vitamin C-deficient group also was significantly lower in plasma, heart, liver, lung and kidney than that of the control group on d 21. On the basis of two-way ANOVA, significant interactions between vitamins C and E were observed on d 21 for vitamin E concentration in these tissues. The ascorbate level in plasma, heart, liver, muscle and kidney of the vitamin E-deficient group was significantly lower than that of the corresponding control group on d 21. Significant interactions between vitamins C and E were observed on d 21 for vitamin C concentration in these tissues. These results suggest a sparing effect of vitamin E on vitamin C, an effect that was observed for the first time in this study. These results suggest that the interaction between vitamins C and E exists in vivo and that the extent of the interaction depends on the tissue. Thiobarbituric acid reactive substances (TBARS) in plasma and liver of the vitamin C-deficient rats were significantly higher than those of the control and the vitamin E-deficient groups on d 21, suggesting that the deficiency of vitamin C caused a larger increase in oxidative stress than the deficiency of vitamin E. TBARS of the liver in rats deficient in both vitamins C and E were significantly higher than those in all other groups, suggesting an additive effect of the deficiencies of vitamins C and E on hepatic TBARS. These data suggest that in vivo, vitamins E and C interact, and each can exert sparing effects in the absence of the other.

Analysis of Variance↗
PubMed1997

Increase of lipid hydroperoxides in tissues of vitamin E-deficient rats.

The level of lipid hydroperoxides was determined by a newly developed method in rat tissues of vitamin E deficiency, which was a good in vivo model of enhanced radical reactions. In the heart, lung and kidney, the level of lipid hydroperoxides increased significantly as early as 4 weeks after feeding on a tocopherol-deficient diet compared with that of the control group. After 8 weeks of the deficiency, similar results were obtained. These results indicate that the lipid hydroperoxide is available as an extremely sensitive indicator of lipid peroxidation in these organs, because it takes several months to detect manifestations of the vitamin deficiency based on conventional indices.

Animals↗
PubMed1997

Asialo GM1-positive cells in mouse cochlea.

The presence of ganglio-N-tetraosylceramide (asialo GM1)-positive cells in mouse cochlea was tested for using an immunohistochemical method with an anti-asialo GM1 antibody which reacts with natural killer cells and macrophages in mouse. Only a few asialo GM1-positive cells were present on the surface of the scala tympani of the basal turn near the collecting venules. Transmission electron microscopic study showed the internal structure of these cells to be that of macrophages. These findings suggest that asialo GM1-positive cells function as resident type macrophages against invasion by pathogens of the mouse cochlea.

Animals↗
PubMed1997

Induction of free radicals in the cochlea by an aminoglycoside antibiotic.

Free radicals are known to cause damage to biological tissues. We used histochemical methods to examine the emergence of free radicals in kanamycin (KM)-treated guinea pig cochlea. As a preliminary in vitro study, the emergence of free radicals was observed in guinea pig cochlea incubated with KM. In an in vivo study, KM was placed on the guinea pig round window membrane and the emergence of free radicals was observed over time. The emergence of free radicals was observed along the luminal membrane and hair bundles of outer hair cells. The appearance and disappearance of free radicals in the cochlea coincided with the transport of KM into the inner ear. These findings suggest that the emergence of free radicals could be attributed to the administration of KM.

Animals↗
PubMed1996

Tumor-induced hypercalcemia and parathyroid hormone-related protein in lung carcinoma.

BACKGROUND: Although lung carcinoma is the most common cause of tumor-induced hypercalcemia (TIH), the precise incidence of TIH remains obscure. Furthermore, the role of parathyroid hormone-related protein (PTHrP) has not been clearly elucidated. METHODS: This study included 690 consecutive patients who were newly diagnosed as having lung carcinoma between 1989 and 1994 (379 adenocarcinomas, 207 squamous cell carcinomas, 75 small cell carcinomas, and 29 large cell carcinomas). All patients were treated for lung carcinoma and were also periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dL. The serum levels of PTHrP (109-141) were measured by a C-terminal-region-specific radioimmunoassay. RESULTS: TIH was observed in 17 of 690 patients (2.5%). All 17 patients demonstrated an advanced stage of lung carcinoma (Stage III or IV), 10 squamous cell carcinomas, 5 adenocarcinomas, 1 small cell carcinoma, and 1 large cell carcinoma. In 15 patients, the serum level of C-PTHrP (109-141) was substantially high, ranging from 99 pmol/L to 890 pmol/L (normal range, 21-50.7 pmol/L). There was no significant difference in the serum PTHrP level between patients with or without bone metastasis. The reduction of tumor burden decreased both the serum level of PTHrP and that of Ca in parallel. The median survival time after diagnosis of TIH was only 27 days. CONCLUSIONS: TIH in lung carcinoma was most likely attributable to PTHrP, and its occurrence appears to be an ominous prognostic sign.

Adult↗
PubMed1996

An experimental model of bone metastasis by human lung cancer cells: the role of parathyroid hormone-related protein in bone metastasis.

In the formation of bone metastasis, osteoclastic bone resorption is necessary before the expansion of tumor cells from bone marrow to bone, and several cytokines, which possess osteoclast-stimulating activity, could be involved in this step. In this paper, we describe a bone metastasis model in nude mice using human lung squamous cell carcinoma-derived cells (HARA), in which the parathyroid hormone-related protein (PTHrP) gene, one of the most potent osteoclast-activating factors, is strongly expressed. The injection of HARA cells (1 x 10(5)) into the left cardiac ventricle resulted in tumor colonies exclusively in the skeletal system at 4 and/or 8 weeks after inoculation. An anti-PTHrP antibody injected via a tail vein reduced the incidence of bone metastases, number of tumor colonies, and tumor volume after the inoculation of HARA cells. The injection of another line of human lung squamous cell carcinoma-derived cells (QG-56), in which the PTHrP gene is not expressed, resulted in no bone metastasis. These findings suggest that PTHrP plays an important role in the formation of bone metastasis.

Animals↗
PubMed1996

Change of the lipid hydroperoxide level in mouse organs on ageing.

Change in the total level of tissue lipid hydroperoxides during ageing in the mouse was determined by our newly developed specific and sensitive method. The hepatic level of lipid hydroperoxides of 5-week-old mice was 239 +/- 31 pmol/mg protein. Hydroperoxide levels in the liver of 20-, 30-, 40-, 60- and 85-week-old groups were 487 +/- 115, 348 +/- 87, 395 +/- 65, 498 +/- 98 and 431 +/- 81 pmol/mg protein, respectively, and these values were significantly higher than the content of the 5-week-old animals. In the heart and kidney, the level of lipid hydroperoxides increased also significantly at 20 weeks of age compared with that of the 5 week-old mouse. The hydroperoxide level did not increase significantly thereafter until 85 weeks of age. The hydroperoxide level in the brain did not change during 5-85 weeks of age.

Aging↗
PubMed1996

Reduced cadmium and lead burden in Japan in the past 10 years.

OBJECTIVE: To investigate the current levels of exposure of the Japanese population to cadmium and lead, in comparison with the levels in 1980s. DESIGN: A nation wide survey was conducted in 1991-1994 (the 1990 study) in 19 study sites in Japan as a follow-up to a study conducted in 1979-1983 (the 1980 study). Blood samples and 24-h total food duplicates were collected from women who did not smoke or drink habitually. METHODS: Blood and food duplicates (after homogenization) were analysed for cadmium (Cd-B and Cd-F, respectively) and lead (Pb-B and Pb-F) by graphite furnace atomic absorption after wet-ashing. RESULTS: Altogether, 467 women volunteered for blood sampling. Of these women, 375 also gave food duplicates. Geometric mean (GM) Cd-B levels in the 1990 study were lower than the corresponding 1980 values in most study sites so that the 1990 grand GM (1.98 ng/ml) for Cd-B was significantly lower than the 1980 GM (3.58 ng/ml). This reduction in Cd-B was related to the reduction in Cd-F (GM for Cd-F was 38.0 micrograms/day in the 1980 study and 30.0 micrograms/day in the 1990 study). Dietary intake was almost exclusively the route of Cd burden among the populations studied. Both Pb-B and Pb-F also showed a remarkable reduction, i.e. from 33.9 ng/ml (1980 GM) to 23.2 ng/ml (1990 GM) in the case of Pb-B, and from 32.2 micrograms/day (1980 GM) to 7.1 micrograms/day (1990 GM) in the case of Pb-F. Pb-B, however, did not correlate with Pb-F either in the 1980 or the 1990 study, because Pb intake via inhalation of air remained significant when compared with dietary intake. CONCLUSION: The Cd burden in Japan has decreased markedly in the past 10 years, although it is still higher than in other countries. The Pb burden has been quite low.

Adult↗
PubMed1996

Dermoid cyst within an upper thoracic meningocele.

A case of dermoid cyst within an upper thoracic meningocele is reported. The incidental feature of this combination is extremely rare. As upper thoracic meningocele is often associated with other spinal and intracranial abnormalities, close observation and radiologic evaluation of the craniospinal axis are necessary to obtain an exact diagnosis and to achieve an appropriate treatment.

Comorbidity↗
PubMed1996

Accuracy of using radiographs for custom hip stem design.

If the shape of the femoral canal could be predicted with sufficient accuracy for the design of custom femoral stems, this would reduce the cost and provide a simpler design method than using computed tomography scans. Five groups of femurs were used for the study. The first two groups were used to determine an average femur shape, described by 25 transverse sections. In the next group of femurs, the shape was predicted from radiographs by distorting the shape of the average femur to conform to the radiographic outlines. The profiles were accurate to within 1 mm on average, the larger errors being in the trochanteric regions. In the proximomedial region, and in the distal canal, the accuracy was better than 0.3 +/- 0.8 mm. When femoral stems were designed from the actual and predicted canals, there was minimal difference in the sections of the two stems. The stems had a particular geometric form with a straight distal end, and flares at the proximomedial and proximoanterior locations; however, when stems designed by either method were inserted into canals prepared by distal reaming and proximal rasping, there was an error in fit in certain regions of approximately 1 mm. It was concluded that for femurs without serious abnormality of shape, a biplane radiographic method was sufficiently accurate for the prediction of canal shape and for the design of a standard type of custom uncemented stem.

Adult↗
PubMed1996

Analysis of Ki-ras codon 12 mutations in the duodenal juice of patients with pancreatic cancer.

BACKGROUND & AIMS: Point mutations of the Ki-ras gene at codon 12 have been frequently identified in pure pancreatic juice of patients with pancreatic cancer in studies examining pancreatic cancer tissues. The aim of this study was to examine mutations of the Ki-ras codon 12 in the duodenal juice collected from patients with various pancreatic disorders. METHODS: The duodenal juice was collected through a Dreiling tube installed in the duodenum during a secretin test. Analysis of the Ki-ras mutations was performed using the enriched polymerase chain reaction--single-strand conformation polymorphism technique. RESULTS: Point mutations were detected in 12 of 19 patients with pancreatic cancer; of the 12 patients, 10 had ductal tubular adenocarcinoma and 2 intraductal papillary adenocarcinoma. Mutational patterns included GAT (n = 4), GTT (n = 3), CGT (n = 1), and double mutations of GTT and GAT (n = 3) and GAT and CGT (n = 1). In 41 patients with benign pancreatic disorders, a point mutation was detected in only 1 patient with chronic pancreatitis. CONCLUSIONS: Analysis of the Ki-ras codon 12 mutations in the duodenal juice is useful in the diagnosis of pancreatic cancer.

Base Sequence↗
PubMed1996

Use of a food composition database to estimate daily dietary intake of nutrient or trace elements in Japan, with reference to its limitation.

Daily dietary intake of 28 trace elements (Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga, Ge, Li, Mg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Si, Sn, Sr, Ti, Tl, V and Zn) were estimated from the food intake records (collected by the 24-h total food duplicate method), taking advantage of recently published trace element composition tables for foods in Japan. Because the number of food items listed in the tables was not sufficient, the calculation was made with not all foods recorded, and the results should be taken as semi-quantitative. The estimated intake was high (i.e. > 1 mg/day as a median) for Al, Cu, Mg, Mn, Si, Sr and Zn, medium (i.e. 2-985 micrograms/day) for As, B, Ba, Be, Cr, Ge, Mo, Ni, Sb, Sc, Se, Sn and Ti, and low (i.e. < 1 microgram/day) for Cd, Co, Li, Pb and V. Comparison of the present estimates with the reported values in the literature on 15 elements showed that close agreements were observed in the cases of 10 elements (i.e. Al, B, Cr, Cu, Mg, Mn, Mo, Ni, Se and Zn) for which the present estimates are above 1 microgram/day, whereas the discrepancies were significant for four elements (i.e. Cd, Co, Pb and V) with < 1 microgram/day intake. When the expected dietary uptake was compared with that by respiration in the cases of the 16 elements for which the atmospheric concentration data in Japan are available, the uptake was exclusively attributable to the dietary route for all 16 elements with the possible exception of vanadium.

Adult↗
PubMed1996

Increased pancreatic metallothionein and glutathione levels: protecting against cerulein- and taurocholate-induced acute pancreatitis in rats.

Recent findings have suggested that oxygen-derived free radicals play an important role in the development and progression of acute pancreatitis. Therefore, the present study was designed to investigate whether metallothionein, a free radical scavenger, can protect against acute pancreatitis. Rats were injected intraperitoneally with zinc, followed by either an infusion of cerulein at 10 micrograms/kg for 4 h or a retrograde injection with 100 microliters/100 g body weight of 5% sodium taurocholate into the pancreaticobiliary duct, in order to induce acute pancreatitis. Zn administration significantly increased the levels of both metallothionein and reduced glutathione in the pancreas; the metallothionein levels reached a peak of 83-fold of normal levels after 24 h. The indications of acute pancreatitis, as well as the mortality, were improved by Zn treatment before the onset of acute pancreatitis. Immunohistochemical studies showed that metallothionein accumulated in the acini of the pancreas in the Zn-treated groups, and with strong staining around the periphery of the vacuoles in the group treated with both Zn and cerulein. These findings suggested that Zn increased both metallothionein and glutathione levels in the pancreas and exerted a beneficial effect against ceruleinor taurocholate-induced acute pancreatitis in rats.

Acute Disease↗
PubMed1996

[Measurement of serum tissue polypeptide antigen (TPA) in patients with malignant tumor using prolifigen TPA-M "Daiichi" kit].

Serum tissue polypeptide antigen (TPA) was measured using a newly developed Prolifigen TPA-M "Daiichi" kit in 1,236 healthy subjects, 2,867 patients with malignant tumors, and 901 with benign diseases. Because 94.0% of healthy subjects had serum TPA under 70 U/l, the cut-off value was set at 70 U/l. Serum TPA was elevated in more than 50% of patients with head and neck cancer, lung cancer, liver cancer, gallbladder or bile duct cancer, pancreatic cancer, colorectal cancer, ovarian cancer, and prostate cancer. The overall positive rate in malignant tumors was 55.5%. Serum TPA was higher in advanced cancer than in earlier stage cancer, and decreased after the resection of the tumor. The false positive rate in benign diseases was 31.3%. ROC analysis revealed the usefulness of TPA as a tumor marker in many cancers. The correlation coefficient between TPA and CYFRA 21-1, and between TPA and TPSA, was 0.747 and 0.694, respectively. In conclusion, measurement of serum TPA using the new kit is useful in the management of patients with various malignant tumors.

Antigens, Neoplasm↗
PubMed1996

[Polymyositis after interferon beta treatment of chronic hepatitis type C].

We reported a case of polymyositis manifested after beta-interferon therapy for chronic viral hepatitis type C. In November 1992, a 62-year-old female was diagnosed as having chronic viral hepatitis type C. In January 1993, she was treated with beta-interferon(total 2.52 x 10(8)IU). In March 1993, after the treatment, she noticed weakness and atrophy of her lower extremities. Neurological examination revealed proximal dominant muscle weakness and atrophy of the extremities. Increased levels of serum CK and aldolase were disclosed on admission. By needle EMG, a low voltage with short duration interference pattern was noted. February 7, by muscle biopsy of the right quadriceps, necrotic myofibers, marked variation in fiber diameter, stromal mononuclear cell infiltration, and endomysial fibrosis was detected. The immunological stain of infiltrating cells in the muscle fibers revealed CD4:CD8 ratio as 64:55, whereas in conventional polymyositis CD8 cells dominate CD4 cells. Diagnosis of polymyositis was made and oral prednisolone 60 mg a day was started. Her symptoms and signs improved gradually and she was discharged after 2 months. Many adverse effects due to immunological disturbances caused by interferon treatment have been reported, but polymyositis due to interferon has been very rare. When interferon will be prescribed, manifestation of polymyositis should be considered.

Chronic Disease↗