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Biomedical subjects

K Iida

Publications and source records attributed to K Iida.

At least 163 records · Page 9Linked to original sources
PubMed1996

Inhibitory effect of erythromycin on interleukin 8 production by 1 alpha,25-dihydroxyvitamin D3-stimulated THP-1 cells.

We have recently reported that long-term administration of erythromycin at a low dose reduced the number of neutrophils and concentrations of interleukin 8 (IL-8) in bronchoalveolar lavage fluid in patients with chronic lower respiratory tract disease. To investigate the mechanism of action of erythromycin, we evaluated its effect on IL-8 production in the 1 alpha,25-dihydroxyvitamin D3-stimulated human monocytic cell line THP-1. Erythromycin at a concentration of 10 micrograms/ml significantly reduced IL-8 production by THP-1 cells stimulated with lipopolysaccharide (10 ng/ml) and 1% normal human serum compared with the amount produced by untreated cells (untreated cells, 2,448 pg/ml; erythromycin-treated cells, 872 pg/ml). Our results suggest that erythromycin may impair IL-8 production by alveolar macrophages, ultimately reducing neutrophil accumulation in the airspace.

Anti-Bacterial Agents↗
PubMed1996

A role of cofilin/destrin in reorganization of actin cytoskeleton in response to stresses and cell stimuli.

1. Cofilin is an essential actin-regulating protein widely distributed in all eucaryotes. The structure and function of cofilin are conserved during evolution. 2. Cofilin depolymerizes F-actin in vitro at alkaline pH and severs F-actin in vitro at pH lower than 7.3. Overexpression of cofilin in viable cells induced bundles of actin filaments suggesting that the severing activity rather than the actin-depolymerizing or monomeric actin-sequestering activity is physiologically significant in vivo. 3. The actin bundle formation induced by overexpression of cofilin is accompanied with an increase in cell motility of Dictyostelium cells. 4. In higher vertebrates, the actin-binding activity of cofilin is negatively regulated by phosphorylation on its Ser-3 residue. The actin-binding activity is essential for yeast cells to grow. 5. Stresses and various cell stimuli activate cofilin by inducing dephosphorylation of cofilin in resting vertebrate cells. 6. Cofilin has an nuclear localization signal sequence and translocates into the nucleus together with actin in response to various stresses. Functional roles of cofilin/actin in the nucleus remain to be elucidated. 7. Tertiary structure of destrin (cofilin) resembles that of gelsolin segment 1 and well explains its functions such as Ca(2+)-independent actin binding activity.

Actin Depolymerizing Factors↗
PubMed1996

Increase of cytochrome b mRNA by bis(2-hydroxyethyl) trisulfide in J774A.1 cells.

The effect of a cytotoxic substance (bis(2-hydroxyethyl) trisulfide; BS-1), isolated from Bacillus stearothermophilus UK563, on messenger ribonucleic acid (mRNA) level in mouse macrophage-like J774A.1 cells was investigated by the method of differential display. The treatment of J774A.1 cells with BS-1 led us to detect the inducible gene. The sequence analysis revealed that the gene was identical to mouse mitochondrial cytochrome b. In fact, Northern blot analysis showed that cytochrome b mRNA in J774A.1 cells was increased by BS-1.

Animals↗
PubMed1996

Studies on 13C-phenacetin metabolism. II. A combination of breath test and urine test of in vivo metabolites in the diagnosis of liver disease.

We determined the optimum 13C-labeling position in phenacetin for use in a breath test to diagnose liver disease based on infrared spectroscopy detection of 13CO2 in exhaled air. ([1-13C]Ethoxy)phenacetin gave the best result. This compound was also employed in a urine test using 13C-NMR spectroscopy. In the urine test, healthy subjects gave a higher signal of phenacetin than of its metabolite, phenetidine, whereas in patients with liver disease the situation was the reverse. The combination of the breath and urine tests may be a valuable new tool for the diagnosis of liver disease.

Acute Disease↗
PubMed1996

Preparation and evaluation of a compressed tablet rapidly disintegrating in the oral cavity.

In order to make a compressed tablet which can rapidly disintegrate in the oral cavity, microcrystalline cellulose and low-substituted hydroxypropylcellulose were used as disintegrants, and ethenzamide and ascorbic acid were chosen as poorly and easily water soluble model drugs, respectively. The mixture of microcrystalline cellulose and low-substituted hydroxypropylcellulose was compressed at 100--500 kgf in the absence of an active ingredient. The properties of these tablets, such as hardness, porosity, the time required for complete wetting of a tested tablet (wetting time), water uptake and disintegration time determined by a new disintegration apparatus, were investigated to elucidate the wetting and disintegration characteristics of these tablets, When the MCC/L-HPC ratio was in the range of 8:2 to 9:1, the shortest disintegration time was observed. The disintegration of tablets containing ethenzamide or ascorbic acid was examined next. Tablet disintegration time in the oral cavity was also tested, and good correlation between the disintegration behaviors in vitro and in the oral cavity was recognized.

Ascorbic Acid↗
PubMed1996

[Pharmacognostical studies on adiantum plants. V. Classification based on spore morphology and distributional patterns of silicon and calcium in the ultimate pinnules].

Crude drugs derived from Adiantum species are used as febrifuge, antidote, diuretic, tonic, etc. Some commercial samples of these drugs are composed of finely cut ultimate pinnules only, which have false indusia and spores. In this paper, in order to establish a classification method based on the characteristics of the ultimate pinnules and their attachments, the morphological study using stereoscope and scanning electron microscope, and X-ray microanalysis using an electron probe microanalyzer were carried out on the false indusia and spores, and the ultimate pinnules, respectively, of 19 Adiantum species. The results showed that examined all species could be distinguished from each other by the following characteristics: in the false indusium, the shape and the presence or absence of hairs; in the spore, the shape, the ornamentation, the ratio of the laesura, and the equatorial diameter; in the X-ray images of the ultimate pinnule, the distributional patterns of silicon and calcium. The distributional patterns of silicon were due to the presence of spicular cells, hairs and papillae, and calcium was present as crystals of calcium oxalate. The average content of silicon in the ultimate pinnules of Adiantum species was 1.99%.

Calcium↗
PubMed1996

Electrophoretic study of lactate dehydrogenase and alkaline phosphatase isoenzymes of the Mongolian gerbil (Meriones unguiculatus).

Lactate dehydrogenase and alkaline phosphatase isoenzymes of the Mongolian gerbil were examined using electrophoretic techniques and were compared with those of the mouse, rat, and guinea pig. Five isoenzymes of lactate dehydrogenase (LDH) were detected in the gerbil with LDH2 and LDH5 being equally dominant. Two bands of alkaline phosphatase (ALP) were distinguished in sera treated with neuraminidase in the gerbil and the relative activity of the cathodic fraction was greater than those of the mouse and rat. Genetic polymorphism was not found among the coat color variants of the Mongolian gerbil. A comparative study on LDH and ALP revealed distinct interspecific differences in the rate of the electrophoretic migration of the respective isoenzymes among the mouse, rat, guinea pig, and the Mongolian gerbil.

Alkaline Phosphatase↗
PubMed1996

Effect of surgery on gonadal function of premenopausal women with pituitary adenomas other than prolactinomas.

The effects of surgery on pituitary-gonadal function were investigated in women with pituitary adenomas other than prolactinomas. The subjects were 46 women of premenopausal age with a pituitary adenoma. Twenty tumors were GH producing, 19 were nonfunctioning, and 7 were adrenocorticotropin producing adenomas. The surgery was performed mainly via the transsphenoidal route, with the aim of eradicating the tumor and preserving pituitary function. The menstrual cycle was preserved postoperatively in 9 out of 10 (90%) patients with regular preoperative menstruation. Menstrual disturbance was seen in 36 (78.3%) cases preoperatively. The causative factors for menstrual disturbance were gonadotropin impairment and hyperprolactinemia in GH producing and nonfunctioning adenoma. Excessive hormonal secretion itself is a major causative factor for menstrual disturbance in GH and ACTH producing adenoma. Regular menstruation was restored following surgery in 20 out of 36 (55.6%) patients with menstrual problems. The predicting factors for postoperative recovery of menstruation are: size of adenoma less than 40 mm, period of amenorrhea less than 5 years, and preoperatively preserved gonadotropin secretion. In addition, preoperative hyperprolactinemia was also a predicting factor in women with nonfunctioning adenoma. Thus, even in patients with pituitary adenomas other than prolactinoma, the restoration of menstruation is highly achievable when surgery is performed with attention to preserving pituitary function.

Adenoma↗
PubMed1996

Effects of surgery on testosterone secretion in male patients with pituitary adenomas.

The purpose of this study was to assess the effect of surgery on gonadal function in 42 male patients with pituitary adenomas Gonadal functions were evaluated by measuring total serum testosterone concentrations pre- and postoperatively. The subjects of the study were 20 patients with GH secreting adenoma, 7 patients with prolactinoma and 15 patients with nonfunctioning (NF) adenoma. Their ages ranged from 18 to 60 years (mean +/- SEM, 41 +/- 1.9). The serum testosterone concentration was low at less than 300 ng/dl preoperatively in 14 of 20 patients (70%) with GH producing adenoma, 6 of 7 patients (86%) with prolactinoma, and 7 of 15 patients (47%) with NF adenoma. Postoperatively, the total serum testosterone concentration was normalized in 9 of 14 patients (64%) with GH producing adenoma, one of 6 patients (17%) with prolactinoma, and 5 of 7 patients (71%) with NF adenoma. The normalization of serum GH and prolactin concentrations is indispensable for the restoration of gonadal function. It is very important to preserve the normal preoperative gonadotropin secretion by means of gentle surgery.

Adenoma↗
PubMed1996

Langerhans cells in mice with severe combined immunodeficiency (SCID).

The existence of Langerhans cells in the stratified squamous epithelium of severely combined immunodeficient (SCID) mice was studied by enzyme histochemistry, immunohistochemistry and electron microscopy. Considerable numbers of ATPase-positive Langerhans cell were observed in the epidermis (ear and hind limb) as well as in the stratified squamous mucosal epithelium (forestomach and tongue) of SCID mice. The cells also expressed Ia antigen. This indicates that, in spite of the lack of functional T and B lymphocytes, the antigen-presenting function of Langerhans cell was retained in SCID mice. In the epidermis, frequency of Ia expressing Langerhans cells was low, but in the forestomach epithelium, 90% of Langerhans cells had strong Ia positivity. In the forestomach epithelium of SCID mice, the regulation of Langerhans cell maturation was affected differently from the epidermis. As with normal mice, the occurrence of Langerhans cell in female SCID mice was higher than in males; hormonal immuno-regulations may be normal in SCID mice. Under electron microscopy, many Birbeck granules were observed in epidermal Langerhans cells but few in those of the mucosal epithelium. In SCID mice, Langerhans cell exists constitutively in the epidermis and mucosal epithelium, where the cell may function in a defense system independent from T and B lymphocytes.

Adenosine Triphosphatases↗
PubMed1996

Protective effect of teprenone on blood flow and incidence of histologic lesions in rat gastric mucosa after hemorrhage and retransfusion.

BACKGROUND: The effects of teprenone (6,10,14,18-tetramethyl-5,9,13, 17-nonadecatetraen-2-one) on changes in gastric mucosal blood flow, adenosine triphosphate (ATP) content, and incidence of histologic lesions were evaluated in rat gastric mucosa after hemorrhage and retransfusion. METHODS: Teprenone (100 mg/kg) was administered orally once a day for 3 consecutive days. On the 3rd day hemorrhage was induced, withdrawn blood (retransfusion) was returned, and the above variables were determined. RESULTS: Teprenone significantly inhibited the decreases in blood flow and index of mucosal oxygen saturation (ISO2) during hemorrhage in the corpus and antral mucosa. However, no effect of teprenone was observed on systemic blood pressure and ATP levels after hemorrhage and retransfusion. Teprenone significantly (p < 0.05) decreased both the incidence of ischemic lesions and the increase in the severity of lesions after retransfusion in both mucosal regions. CONCLUSION: From these results, it is concluded that the protective effect of teprenone on blood flow was partly responsible for its inhibitory effect on the incidence of lesions in the rat stomach in this hypovolemic shock model, although the former effect might be not a direct effect on systemic vascular tone.

Adenosine Triphosphate↗
PubMed1996

[A case of Paget's disease with progressive sensorineural hearing loss involved in the bilateral bony labyrinths].

Paget's disease of the bone is a chronic, progressive disease of unknown etiology characterized by abnormal bony resorption and deposition. It is a common skeletal disease in Europe and North America, while in Japan it is very rare. Paget's disease of the temporal bone has been reported to cause hearing loss frequently. We report a 50-year-old woman with Paget's disease who had progressive bilateral sensorineural hearing loss and right vestibular dysfunction. CT and 3 Dimensional CT (3D-CT) images demonstrated resorption of the entire bony labyrinth and its surroundings on both sides and that the temporal bone elsewhere remained intact. Bone scans revealed disease symmetrically in the bilateral otic capsules. Previous studies indicated that the bone changes in Paget's disease in the petrous pyramid begin in areas best supplied with marrow tissue and that the otic capsule is relatively spared until advanced changes are present in the remainder of the petrous pyramid. But, this patient mainly had foci in the bilateral otic capsules and the pattern was similar to cochlear otosclerosis. 3D-CT was useful for differentiation of Paget's disease and cochlear otosclerosis. The pattern of the affected areas indicated that this is a very rare situation even in the reports of Europe and North America, where the disease is rather common.

Diagnosis, Differential↗
PubMed1996

Simple 13C-urea breath test with infra-red spectrophotometer.

When mass spectrophotometric analysis is used for the 13C-urea breath test to assess H. pylori infection, it is costly, complicated, and time-consuming. To overcome these disadvantages, we utilized an infra-red spectrophotometer as a substitute for the mass spectrophotometer. A total of 153 patients (181 tests) analyzed with peptic ulcers or non-ulcer dyspepsia were investigated. Breath samples were collected 15 min after ingestion of 13C-urea (100 mg in 30 ml water). An infra-red spectrophotometer was used to determine the concentration of 13CO2 in the expirate. The 13CO2/12CO2 ratio was also measured by mass spectrophotometry to compare results with those of infra-red spectrophotometric analysis. Direct detection of H. pylori was qualified in biopsy specimens. Of the 181 biopsies, 138 were positive for H. pylori infection and 43 were negative. With the urea breath test, the mean value in the positive group was significantly higher than that in the negative group (0.062 +/- 0.044 vs 0.011 +/- 0.014, respectively). The cut-off level, 0.01, was determined as delta 13C atom %. The sensitivity of infra-red spectrophotometry was 97.8% (135/138) and specificity was 74.4% (32/43). There was an extremely high coefficient of correlation (r = 0.996) between mass and infra-red photometric analysis. Infra-red spectrometry appears to have great potential not only for diagnosing H. pylori infection but also for assessing treatment results. Its advantages include technical simplicity, cost-effectiveness, and high accuracy.

Breath Tests↗
PubMed1996

[Histopathological study of valvular deposits of amyloid protein in cardiac amyloidosis].

Cardiac amyloidosis is associated with amyloid deposits in cardiac valves which also show the thickening of leaflets and cusps. This study examined amyloid deposits on cardiac valves to investigate the possible involvement in echocardiographic valvular abnormalities in 17 patients with systemic amyloidosis (12 males and 5 females aged 44 to 82, mean 66.4 years) in the autopsy files of the National Cardiovascular Center between 1980 and 1993. All four cardiac valves were examined histologically using hematoxylin-eosin and Congo red stains with polarization. All cusps and leaflets were divided into six segments and all segments of each cusp and leaflet were scored for the proportional area of amyloid deposit (from 0 to 3). The immunohistochemical types of amyloid proteins were immunoglobulin light chain-related (AL) amyloidosis in 16 cases, and amyloid A-related (AA) amyloidosis in one case. Twelve of 16 cases with AL amyloidosis were subclassified as AL lambda type and 4 were subclassified as AL kappa type. In the atrioventricular valve leaflets, the atrial side of basal portion showed the most remarkable amyloid deposits among the six segments. In the semilunar valves, amyloid deposits were mild in the tip and middle portions. Among the patients with AL amyloidosis, those with AL lambda type amyloid appeared to have greater deposits than those with AL kappa type amyloid. Mitral valves appearing abnormal by echocardiography had greater amyloid deposits. However, considering other factors affecting valvular function, the relationship between the localization or the degree of amyloid deposition and endocardiographic valvular abnormalities was unclear.

Adult↗
PubMed1995

Periventricular leukomalacia, glial development and myelination.

In perinatal leukomalacia, the brain pathology exhibits several different distribution patterns, according to cerebrovascular and glial maturity or various causal factors. Periventricular leukomalacia occurs in the prenatal as well as the postnatal period, and is caused by, in addition to predisposing factors, cerebral hypoperfusion which is in turn caused by systemic hypotension or intracranial vascular constriction and circulatory disturbance. Oligodendroglial damage or diffuse astrogliosis associated with leukomalacia may lead to delayed or reduced myelination in the cerebral white matter.

Brain↗
PubMed1995

A possible role of vitamin D receptors in regulating vitamin D activation in the kidney.

The vitamin D endocrine system is regulated reciprocally by renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylases. Previously, we reported that renal proximal convoluted tubules, the major site of 1 alpha, 25-dihydroxyvitamin D3 production, have vitamin D receptors. In the presence of vitamin D receptors, renal proximal convoluted tubules cannot maintain the state of enhanced production of 1 alpha, 25-dihydroxyvitamin D3. To clarify this discrepancy, we proposed a working hypothesis for the reciprocal control of renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylase activities. In rat models of enhanced renal production of 1 alpha, 25-dihydroxyvitamin D3, expression of vitamin D receptors and 25-hydroxyvitamin D3 24-hydroxylase mRNAs was strikingly suppressed in renal proximal convoluted tubules but not in the cortical collecting ducts. In vitamin D-deficient rats with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity, expression of vitamin D receptor mRNA in renal proximal convoluted tubules was also down-regulated, indicating that the down-regulation of vitamin D receptor mRNA is not the result of the enhanced production of 1 alpha, 25-dihydroxyvitamin D3. In Japanese quail models with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity by sex steroids, expression of vitamin D receptor mRNA was also down-regulated in the kidney but not in the duodenum. These results suggest that the down-regulation of vitamin D receptors plays a critical role in production of 1 alpha, 25-dihydroxyvitamin D3 in renal proximal convoluted tubules.

Animals↗
PubMed1995

Response to isoproterenol as a prognostic indicator of evolution from hypertrophic cardiomyopathy to a phase resembling dilated cardiomyopathy.

OBJECTIVES: We sought to assess whether isoproterenol stress echocardiography could detect in advance in which patients hypertrophic cardiomyopathy would progress to a phase resembling dilated cardiomyopathy. BACKGROUND: In a few patients, hypertrophic cardiomyopathy has been reported to progress to a phase characterized by systolic dysfunction and left ventricular dilation, resembling dilated cardiomyopathy. METHODS: Echocardiograms were recorded before and immediately after intravenous infusion of isoproterenol (0.02 microgram/kg body weight per min) for 5 min in 18 patients with typical hypertrophic cardiomyopathy (i.e., hypertrophied, hyperdynamic and nondilated) to determine the difference in fractional shortening. The patients were categorized into those with a good response (difference in fractional shortening > 7%, 14 patients) and those with a poor response (difference < or = 7%, 4 patients). Changes in left ventricular end-diastolic diameter and fractional shortening were evaluated by using serial echocardiography over an average follow-up period of 5.4 years. RESULTS: In the good response group, neither end-diastolic diameter nor fractional shortening changed significantly during the follow-up period. In the poor response group, end-diastolic diameter significantly increased from a mean +/- SD of 41 +/- 5 to 53 +/- 5 mm (p < 0.05), and fractional shortening significantly decreased from 40 +/- 12% to 29 +/- 10% (p < 0.05). All patients in the poor response group showed a substantial decrease (> or = 5%) in fractional shortening and an increase (> or = 5 mm) in end-diastolic diameter. One patient developed congestive heart failure due to systolic dysfunction during the observation period. CONCLUSIONS: The present study confirmed that impaired responses to isoproterenol infusion are related to future deterioration of left ventricular performance in patients with typical hypertrophic cardiomyopathy.

Cardiomyopathy, Dilated↗