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Biomedical subjects

T Iida

Publications and source records attributed to T Iida.

At least 235 records · Page 13Linked to original sources

Active leprosy treated effectively with ofloxacin.

The patient is a 25-year-old Filipino who showed polymorphous eruptions over the whole body, right ulnar nerve paresis, polyneuropathy and hypalgesia in the area of eruptions. Because the biopsy specimen showed foam cells, histiocytes, epithelioid cells, many Mycobacterium leprae and no giant cells, the diagnosis of borderline-lepromatous (BL) type was made. The symptoms were improved by the administration of 300 mg/day ofloxacin. Because the monotherapy using ofloxacin has been reported to be effective in all 5 previously reported cases of BL type leprosy, it may be recommended for a larger number of leprosy cases.

Adult↗

Value of three-dimensional spiral CT hepatic angiography.

OBJECTIVE: The aim of this study was to compare with conventional angiography images the diagnostic utility of three-dimensional CT hepatic angiography (CTHA) images reconstructed from spiral CT images obtained during direct injection of contrast material into hepatic arteries. MATERIALS AND METHODS: Three-dimensional CTHA images were reconstructed from spiral CTHA images obtained during direct hepatic arterial contrast material injection in 22 patients. We used maximum-intensity-projection (MIP) and shaded-surface-display (SSD) techniques. We compared matched pairs of MIP CTHA images and SSD CTHA images with conventional angiograms for depiction of peripheral (segmental to subsegmental order branches) and proximal (common to proper) hepatic arteries as well as for conspicuity of the entire hepatic arterial tree in 22 patients and for conspicuity of tumors, recognition of tumor sites, and depiction of tumor-feeding arteries in 21 patients with malignant liver tumors. Our evaluations were performed in a blinded fashion by two experienced radiologists, who reached a consensus. (These radiologists also counted the number of tumors depicted by each method in the 21 patients with malignant liver tumors.) RESULTS: Depiction of peripheral and proximal hepatic arteries and conspicuity of the entire hepatic arterial tree were significantly better on conventional angiograms than on MIP CTHA images and SSD CTHA images. Conspicuity of tumors and recognition of tumor sites were significantly better on MIP CTHA images and SSD CTHA images than on conventional angiograms. Depiction of tumor-feeding arteries was significantly better on MIP CTHA images than on SSD CTHA images and conventional angiograms. For 47 malignant liver tumors, MIP CTHA images showed 40 (85%), SSD CTHA images showed 34 (72%), and conventional angiograms showed 20 (43%). CONCLUSION: MIP CTHA images showed liver tumors, tumor sites, and tumor-feeding arteries better than conventional angiograms. MIP was the preferred method for three-dimensional CTHA analysis.

Aged↗

[Choroidal vascular lesions in serous retinal detachment viewed with indocyanine green angiography].

In serous retinal detachment due to damaged retinal pigment epithelium (RPE), fluorescein angiography shows dye leakage into the subretinal space from the choroid. We performed indocyanine green (ICG) angiography in 110 eyes with serous retinal detachment comprising 71 eyes with central serous chorioretinopathy (CSC), 19 with bullous retinal detachment, 18 with Harada's disease, and 2 with toxemia of pregnancy. Choroidal tissue staining was present around the site of subretinal leakage in late-phase ICG angiograms from 63 eyes with CSC and 18 with bullous retinal detachment. ICG angiography also showed leakage from choroidal vessels in 16 eyes with Harada's disease and 2 with toxemia of pregnancy. As a common feature, ICG angiography showed choroidal vascular hyperpermeability in various types of serous retinal detachment. Choroidal circulation was delayed in Harada's disease and toxemia of pregnancy. Choroidal hypoperfusion and hyperpermeability of choroidal vessels probably contribute to the damage of RPE, and choroidal vascular hyperpermeability probably provides fluid pressure to move fluid into the subretinal space from the choroid.

Adult↗

[Analysis of risk factors for development of bronchopleural fistula after pneumonectomy for lung cancer].

Bronchopleural fistulas (BPF) developed in six (7.9%) of 76 patients who underwent a pneumonectomy for treatment of lung cancer. Five patients (18.2%) underwent a right pneumonectomy and one (3.7%) a left pneumonectomy. All patients were male, had squamous cell carcinoma, and were diagnosed as having BPF within one month after pneumonectomy. Their average age was 60.2 years. Univariate analyses related to development of BPF showed that significant risk factors were preoperative infection (Chi-square test; p < 0.001), right pneumonectomy (Chi-square test; p < 0.05), and metastasis to a subcarinal lymph node (Chi-square test; p < 0.05). However, sex, age, operating time, amount of blood loss during surgery, amount of blood transfused during surgery, history of smoking, degree of lymph node dissection, degree of curability, performance of combined resection, histologic type of tumor, tumor size, presence of residual tumor at the bronchial stump, and suturing method were not significant risk factors for development of BPF. Our stepwise regression analysis related to development of BPF showed that preoperative infection, metastasis to a subcarinal lymph node, right pneumonectomy, and combined resection were significant risk factors. Sometimes it is difficult to preserve the bronchial arteries upon the dissection of metastatic subcarinal lymph nodes which tightly adhere to the bronchial sheath. Moreover, after a conventional right pneumonectomy, the bronchial stump protrudes into the pleural cavity and is not covered by any tissue. Ligation of the bronchial arteries or protrusion of the bronchial stump into the right pleural cavity reduces the blood supply to the bronchial stump to a very low level and causes development of BPF. Therefore, we suggest that control of preoperative infection, wrapping of the bronchial stump, and preservation of the bronchial arteries during mediastinal lymph node dissection are important to prevent development of BPF.

Bronchial Fistula↗

[Total repair of tetoralogy of Fallot in an adult: report of a case without prior treatment at 59 years of age].

We reported successful repair of tetoralogy of Fallot of a male case aged 59 years old. There was no palliative operation prior to this correction. The preoperative clinical features were as follows: dyspnea on effort and at rest, cyanosis and clubbing, multiple cerebral thrombosis without symptoms. Polycytemia was remarkable at Hb 23.3 g/dl and Ht 73.8%. PaO2 was 39.2 mmHg and hypoxemia was recognized. CTR was 59% and pulmonary vascular shadows were decreased but bilateral pulmonary arteries were well developed. Cardiac catheterization showed that high RV systolic pressure equal to that of LV and severe RV outflow obstruction. Pulmonary artery was well developed (the diameter ratio of PA and aorta: 0.84). Collateral arteries to the pulmonary vascular system were not significant by aortography. The surgical procedures were performed under conventional method. Pulmonary valvular stenosis was released by comissurotomy and RV outflow tract obstruction was also released through minimal right ventriculotomy. The conus branch of coronary artery crossed the outflow tract, so that we preserved this artery for preventing right ventricular failure post-operatively. There was no need to use trans-annular patch for reconstruction of the outflow tract. In post operative course, only a low dosage of catecholamin was required but no other special treatment was needed. Ventricular and supraventricular arrhythmia had appeared in short period but after administration of anti arrhythmic drugs, heart rhythm was converted to sinus rhythm easily. Pathological findings of RV muscle which resected at the operation showed marked fibrous degeneration and irregularity of cells, and it suggested that sever hypoxia and high pressure for long time affected the ventricular muscle. We concluded that even older patients of tetralogy of Fallot were corrected safely and were able to get good quality of life after operation.

Age of Onset↗

[Establishment of a new human ovarian serous cystadenocarcinoma cell line (IM), and influence on cell proliferations by cisplatin with or without hyperthermia].

A new cell line, designated IM has been established from operation material derived from a woman with ovarian serous cystadenocarcinoma. The population doubling time of the 35th passage IM cell was 28.8 hours. And it was successively subcultured 165 times in over 7 years, moreover still kept CA125 production. The nuclear DNA and cell surface CA125 antigen were double stained by propidium iodide and anti CA125 monoclonal antibody-FITC. Then the two color cytogram obtained by flow cytometry was drawn up. For the most part of CA125 positive cell retained G0 + G1 of cell cycle, the lesser part was in G2 + M phase. The S phase rate of IM cell incubated with cisplatin at 37 degrees C or 41 degrees C for 1 hour that estimated by BrdU-propidium iodide double stain method of flow cytometry, it was suggested that the inhibition of DNA synthesis by cisplatin was increased with 41 degrees C low hyperthermia.

CA-125 Antigen↗

Ca(2+)-independent cytotoxicity of Vibrio parahaemolyticus thermostable direct hemolysin (TDH) on Intestine 407, a cell line derived from human embryonic intestine.

The effects of Vibrio parahaemolyticus thermostable direct hemolysis on Intestine 407, a cell line derived from the intestine of human embryos, were investigated. The hemolysin was shown to be cytotoxic to Intestine 407. This cytotoxicity is accompanied by the damage of plasma membrane and lysosomes, as well as cellular degeneration in the form of large transparent blebs. Although an increase in cytosolic free Ca2+ due t the influx of extracellular Ca2+ was observed in cells treated with thermostable direct hemolysin, it was found to be irrelevant to any of the above effects. These results suggest that the effects of thermostable direct hemolysin observed in this study on Intestine 407 are not mediated by Ca(2+)-dependent pathways.

Bacterial Toxins↗

NOC, a nitric-oxide-releasing compound, induces dose dependent apoptosis in macrophages.

The ability of exogenous nitric oxide (NO) to induce apoptosis in macrophages was analyzed using NOC, a NO-releasing compound, as a source of NO. Exogenous NO was shown to induce apoptosis in a dose dependent manner. Quantitative analysis revealed that the amount of NO required to induce apoptosis in more than half of macrophages exposed was 100 times larger than that for endogenous NO-induced apoptosis. NOC proved to be a convenient and useful tool for investigation of apoptosis related to NO.

Animals↗

Structural aspects of bile acids involved in the regulation of cholesterol 7 alpha-hydroxylase and sterol 27-hydroxylase.

We have recently reported that coordinate down-regulation of cholesterol 7 alpha-hydroxylase and sterol 27-hydroxylase by bile acids results in suppression of bile acid synthesis in cultured rat hepatocytes [Twisk, J., De Wit, E. & Princen, H. M. G. (1995) Biochem. J. 305, 505-511]. In the current study, we have assessed the effects of a large group of different bile acids, both naturally occurring and synthetic, on these two key enzymes, to elucidate structural features which render bile acids potent as regulators of bile acid synthesis. Addition of 50 microM deoxycholate or cholate, two relatively hydrophobic bile acids, to the culture medium of hepatocytes resulted in strong suppression of cholesterol 7 alpha-hydroxylase (suppression of 75%) and 88%, respectively) and sterol 27-hydroxylase activity (suppression of 76% and 72%, respectively). These effects were also reflected in the mRNA levels and the transcriptional activities of the two enzymes, showing a parallel suppression of both parameters in response to cholate (suppression of 78% and 43% for cholesterol 7 alpha-hydroxylase mRNA and transcription, respectively, and suppression of 76% and 42% for sterol 27-hydroxylase mRNA and transcription, respectively). In contrast, no effects were observed with the two hydrophilic bile acids, beta-muricholate and ursocholate. Transient expression analysis in cultured rat hepatocytes, using a promoter-reporter construct containing the proximal part of the cholesterol 7 alpha-hydroxylase promoter, demonstrated a reduction of transcriptional activity by cholate (reduction of 72%), but not by ursocholate. Assessment of the effects of 27 different bile acids, varying in the number, position and orientation (alpha/beta) of hydroxyl groups on the steroid nucleus of the molecule, on cholesterol 7 alpha-hydroxylase mRNA showed only a moderate correlation with the hydrophobicity index of the bile acid involved (r = 0.61; P < 0.0001). Analysis of the three-dimensional structure of a number of these bile acids suggests that hydroxyl groups situated in close proximity to each other within the molecule, creating a hydrophilic environment, as in the case of cholate, may be a prerequisite for a strong inhibitory potency. Deviation from this situation leads to a markedly lesser effect on suppression of cholesterol 7 alpha-hydroxylase and sterol 27-hydroxylase.

Animals↗

Gas chromatographic separation of bile acid 3-glucosides and 3-glucuronides without prior deconjugation on a stainless-steel capillary column.

A method for the gas chromatographic (GC) separation of the 3-glucoside and 3-glucuronide conjugates of bile acids without the necessity for a hydrolytic step is described. The bile acid glycosides were derivatized to their complete methyl ester trimethylsilyl (Me-TMS) or methyl ester dimethylethylsilyl (Me-DMES) ether derivatives, which in turn were chromatographed on an inert and thermostable stainless-steel capillary column, Ultra ALLOY-1 (HT), coated with a thin film (0.15 micron) of chemically bonded and cross-linked dimethylsiloxane. They exhibited a single peak of the theoretical shape without any accompanying peaks due to thermal decomposition, even at oven temperatures of 320-330 degrees C. Excellent GC separation of isomeric bile acid glycosides was achieved by the combined use of suitable derivatives and column. This method, which does not need the prior deconjugation of the glycosidic moiety, could be usefully applied to biosynthetic and metabolic studies of bile acids in biological materials.

Bile Acids and Salts↗

Effects of endothelin-1 on Ca2+ signaling and secretion in parathyroid cells.

It has been previously reported that parathyroid cells express endothelin (ET) receptors and secrete ET-1 in an extracellular Ca2+ concentration ([Ca2+]e)-dependent manner. Here, we examined the effects of ET-1 on intracellular signaling and parathyroid hormone (PTH) secretion in dispersed bovine parathyroid (bPT) cells, which comprise several cell types including epithelial and endothelial cells, in two cell lines, the rat parathyroid epithelial (PT-r) and the bovine parathyroid endothelial (BPE-1) cells. An RNA-polymerase chain reaction analysis revealed that both ETA and ETB receptors are expressed in bovine parathyroid tissue and BPE-1 cells, and only the ETA receptor is expressed in PT-r cells. PT-r cells also expressed an inositol 1,4,5-trisphosphate (Ins[1,4,5]P3) receptor, and ionomycin induced an increase in the intracellular Ca2+ concentrations ([Ca2+]i) in a Ca(2+)-deficient medium, indicating the presence of an operative intracellular Ca2+ pool in these cells. In cells bathed in 1 mM [Ca2+]e, ET-1 induced a rapid and transient increase in the Ins(1,4,5)P3 production, which was associated with a similar profile of increase in [Ca2+]i and with a peak response of about 800 nM. No changes in the profile of [Ca2+]i responses were observed in ET-1-stimulated cells in the presence of Ca2+ channel blockers, or in Ca(2+)-deficient medium, indicating that Ca2+ mobilization was not associated with Ca2+ entry. Furthermore, a sustained stimulation with ET-1 induced a decrease in [Ca2+]i below the prestimulatory level in a large population of cells, and the percentage of the cell population that shows the sustained decrease of [Ca2+]i increased in higher ET-1 concentrations. [Ca2+]i in PT-r cells was also controlled by a [Ca2+]e-dependent mechanism that changed [Ca2+]i from 28 to 506 nM in a 0.1-3 mM concentration range with an EC50 of 1.2 mM, which is comparable to that reported for bPT cells. In the same range of [Ca2+]e, PTH secretion from bPT cells was inhibited with an IC50 of 1 mM, and ET-1 increased PTH release in a dose-dependent manner but without affecting the IC50 for the [Ca2+]e-dependent inhibition. Thus, the parathyroid epithelial cells appear to respond to ET-1 in a unique way, and the ET autocrine system can be regarded as a possible mechanism to modulate the sensitivity of [Ca2+]e-dependent PTH release.

Animals↗

Isolation of mutant toxins of Vibrio parahaemolyticus hemolysin by in vitro mutagenesis.

Thermostable direct hemolysin produced by Vibrio parahaemolyticus is a major virulence factor of the organism. The hemolysin has a variety of biological activities such as lethality to mice, cytotoxicity to cultured cells, cardiotoxicity, and fluid accumulating activity in rabbit ileal loop test. In this study, we attempted to isolate less hemolytic mutant toxins of the thermostable direct hemolysin to use them for analysis of mode of action of the hemolysin. Six mutant toxins were obtained by in vitro mutagenesis of the cloned gene for the hemolysin. Characterization of the mutant toxins demonstrated that single amino acid substitutions at Gly62, Trp65, Thr67, Gly86, Glu116 and Glu138 resulted in a loss or lowering of the hemolytic activity. Two of the mutant toxins inhibited hemolysis by wild-type toxin on rabbit blood agar plates, while their hemolytic activity was below the detectable level. These mutant toxins would be useful for identifying the as yet unknown receptor for the hemolysin on the target cell membrane.

Bacterial Toxins↗

Urease production correlates with possession of the trh gene in Vibrio parahaemolyticus strains isolated in Thailand.

A total of 489 Vibrio parahaemolyticus isolates from patients in Thailand with diarrhea was examined for the presence of thermostable direct hemolysin (TDH) and TDH-related hemolysin genes (tdh and trh, respectively), their serovars, TDH production, and urease activity. Of the strains, 81% were positive only for the tdh gene, 6% for both trh and tdh genes, and 2% for the trh gene only. Thirty-seven (8%) of the 489 isolates were positive for urease production. Of special interest, all urease-positive strains possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahaemolyticus strains strongly correlates with the possession of the trh gene. Thus, the urease-positive phenotype of V. parahaemolyticus can be considered an indication of virulent (trh-possessing) V. parahaemolyticus strains in clinical diagnosis.

Bacterial Proteins↗

Measurements of thoron progeny concentration using a potential alpha-energy monitor in Japan.

It is reported that thoron concentration in Japanese dwellings may be higher than in other dwellings. Therefore, in order to assess the risk for indoor thoron progeny, the portable potential alpha-energy monitor has been developed. The monitor detects alpha-particles from the 212Po collected on the filter using a piece of cellulose nitrate film. The detection efficiency of the alpha-particles has been estimated by Monte Carlo calculation. From the results of measurements, the mean indoor thoron progeny concentration in the dwellings was 1.5 Bq m-3 (ECTn), and ranged from 0.04 to 8.2 Bq m-3. The effects of three typical interior walls (soil-based plaster, concrete, and modern materials) on the thoron progeny supply were considered. The mean annual effective dose equivalent was 0.45 mSv.

Air Pollutants, Radioactive↗

Some problems on the measurement of 222Rn concentrations by passive cup method.

A passive cup monitor has been constructed by using a 50 mm radius stainless steel hemisphere. The conductive housing has reduced the scatter in track densities. In dwellings with high 220Rn concentrations, it is particularly necessary to measure 222Rn concentration with a monitor having a radon exchange rate less than 0.1 h-1.

Radiation Monitoring↗

Anti-Ro/SSA-associated annular erythema in childhood.

We report four children with anti-Ro/SSA positive who presented with an annular erythema as a manifestation of Sjögren's syndrome. One patient had an aseptic meningoencephalitis as well as cutaneous lesions. Children with annular erythema should be carefully followed for features of Sjögren's syndrome, which is believed to be a rare condition in children.

Adolescent↗