Biomedical subjects

T Uchino

Publications and source records attributed to T Uchino.

At least 19 recordsLinked to original sources

PubMed2006

Effects of high peak airway pressure on the expression of heat shock protein 70 in rat lungs: a preliminary study.

BACKGROUND: Heat shock protein 70 (HSP70) is induced by a wide variety of stresses in addition to hyperthermia. Recent studies have clarified that mechanical stretching and pressure overload can induce HSP70 in some tissues and cells. However, it remains unclear whether HSP70 is induced in stretch-subjected lungs, such as those under mechanical ventilation. This study was designed to investigate the effects of high peak airway pressure (PAP) ventilation on HSP70 expression in intact rat lungs. METHODS: Male Sprague-Dawley rats were randomly allocated to one of three groups: non-ventilated (anesthesia alone) control group; PAP 15 cm H(2)O group (P15); and PAP 30 cm H(2)O group (P30). The rats in the PAP groups were subjected to pressure-controlled assisted ventilation at the appropriate PAP for 30 min. Rats were killed at 12, 24 and 48 h after ventilation or anesthesia alone, and the lungs were removed. The lung tissues were processed for immunohistochemical and Western blotting analyses of HSP70. RESULTS: Following 30 min of pressure-controlled assisted ventilation, HSP70 expression in the P30 group was significantly up-regulated in bronchiolar cells and subepithelial tissues at 12 h, and this up-regulation continued throughout the observation period. In contrast, there were no significant differences between the control and P15 groups, although the expression of HSP70 was higher in the P15 group than in the control group at all time points. CONCLUSIONS: HSP70 was induced by high PAP ventilation, but its specific role and induction mechanism remain unclear. Therefore, further investigations should be encouraged.

Airway Resistance↗

PubMed2005

Intake of arsenic from water, food composites and excretion through urine, hair from a studied population in West Bengal, India.

To evaluate the main intake source of arsenic by the villagers from arsenic-affected families in Jalangi and Domkol blocks in Mushidabad district, West Bengal-India, we determined the concentrations of arsenic in tube-well water and in food composites, mainly including vegetables and cereals collected from the surveyed families which were cultivated in that region. The daily dietary intakes of arsenic by the villagers were estimated and the excretions of arsenic through urine and hair were determined. The arsenic concentrations in hair and urine of the studied population living in mild (2.78 microg/L), moderate (30.7 microg/L) and high (118 microg/L) arsenic-affected families were 133, 1,391 and 4,713 microg/kg and 43.1, 244 and 336 microg/L, respectively. The linear regressions show good correlations between arsenic concentrations in water vs hair (r(2)=0.928, p<0.001) and water vs urine (r(2)=0.464, p<0.01). Approximately 29.4%, 58.1% and 62.1% of adult population from mild, moderate and high arsenic-affected families were suffering from arsenical skin manifestations. The mean arsenic concentrations of food composites (vegetables and cereals) in high arsenic-affected families are not significantly different from mild arsenic-affected families. The daily dietary intakes of arsenic from water and food composites of the studied population, living in high, moderate and mild arsenic-affected families were 568, 228 and 137 microg, respectively. The linear regressions show good correlations between arsenic concentrations in hair vs daily dietary intake (r(2)=0.452, p<0.001) and urine vs daily dietary intake (r(2)=0.134, p<0.001). The water for drinking contributed 6.07%, 26.7% and 58.1% of total arsenic in our study from mild, moderate and high arsenic-affected families. The result suggested that the contaminated water from high arsenic-affected families should be the main source for intake of arsenic. On contrary, the contribution of arsenic-contaminated food composites from mild and moderate arsenic-affected families might be the main source for intake of arsenic. The Food and Agriculture Organization/World Health Organization (FAO/WHO) provisional tolerable weekly intake (PTWI) values of arsenic in our study were 3.32, 5.75 and 12.9 microg/kg body weight/day from mild, moderate and high arsenic-affected families, respectively, which is higher than the recommended PTWI value of arsenic (2.1 microg/kg body weight/day).

Adult↗

PubMed2004

Potent protecting effects of Catuaba (Anemopaegma mirandum) extracts against hydroperoxide-induced cytotoxicity.

Ishigami et al. (Ishigami et al., 1998) reported that squalene monohydroperoxide (SQOOH) induced skin damage in hairless mice. Kohno and Takahashi (Kohno and Takahashi, 1993) reported that SQOOH induced cytotoxicity against Chinese hamster lung fibroblasts. We have already evaluated the efficacy of extracts obtained from Brazilian herbal medicines in protecting the normal human epidermis keratinocytes [NHEK(B)] against the cytotoxicity caused by SQOOH. The EtOAc extract was separated by silica-gel column chromatography into eight fractions. Fractions (Fr) 1,3 and 5 significantly protected rat basophilic leukemia (RBL-2H3) cells from the release of beta-hexosaminidase due to SQOOH. Additionally, Fr5-1 was most effective in a Gunze three-dimensional cultured human skin model (Vitrolife-skin) against the cytotoxicity due to SQOOH and the release of interleukin (IL)-2 and IL-4. The mixture of cinchonains Ia and Ib and the mixture of cinchonains IIa and IIb were isolated from Fr3 and Fr5-1, respectively. The results suggest that the addition of SQOOH caused the reduction in cell viability and the release of beta-hexosaminidase and cytokines as chemical mediators. The extract of Catuaba (Anemopaegma mirandum) prevented these toxic effects with the main active agents suggested to be cinchonains IIa and IIb.

Animals↗

PubMed2002

Survey of arsenic in food composites from an arsenic-affected area of West Bengal, India.

An investigation of total arsenic in food composites, collected from the villagers, was carried out in arsenic-affected areas of the Murshidabad district, West Bengal where the agricultural system is mostly groundwater dependent. The shallow, large-diameter tubewells installed for agricultural irrigation contain an appreciable amount of arsenic (mean 0.085 mg/l, n=6). Even the soil is arsenic-contaminated (mean 11.35 mg/kg, n=36), so some arsenic can be expected in the food chain from crops cultivated in this area. The results revealed that the individual food composite and food groups containing the highest mean arsenic concentrations (microg/kg) are potato skin (292.62 and 104), leaf of vegetables (212.34 and 294.67), arum leaf (331 and 341), papaya (196.50 and 373), rice (226.18 and 245.39), wheat (7 and 362), cumin (47.86 and 209.75), turmeric powder (297.33 and 280.9), cereals and bakery goods (156.37 and 294.47), vegetables (91.73 and 123.22), spices (92.22 and 207.60) and miscellaneous items (138.37 and 137.80) for the Jalangi and Domkal blocks, respectively. Arsenic is absorbed by the skin of most of the vegetables. The arsenic concentration in fleshy vegetable material is low (mean 2.72 microg/kg, n=45). Higher levels of arsenic were observed in cooked items compared with raw. Daily dietary intakes of arsenic (microg) from the foodstuffs for adults are 171.20 and 189.13 and for children are 91.89 and 101.63 in the Jalangi and Domkal blocks, respectively.

Adult↗

PubMed2002

Quantitative determination of OH radical generation and its cytotoxicity induced by TiO(2)-UVA treatment.

Titanium dioxide (TiO(2)) has been reported to produce OH radical under ultraviolet-A (UVA) irradiation and to induce cytotoxicity. Various crystal forms and sizes of TiO(2) with UVA irradiation from OH radical generation was analysed spin trapping-X band (electron-spin resonance (ESR) spectroscopy. The amount of OH radical was determined with ESR signal intensity of the adducts in which OH radical was trapped with the spin-trapping reagent dimethyl pyrroline-N-oxide (DMPO). The formation of OH radicals varied in both crystal size and form of TiO(2). Irradiation of the anatase form of TiO(2) produced large numbers of OH radical in TiO(2) and UVA in a dose-dependent manner, but rutil form (90 nm in size) showed less OH radical generation. The crystal size had large influence on OH radical generation, but the optimum size for the OH radical generation was different between both forms. The UVA absorption spectrum of TiO(2) differed in regard to crystal size and form of TiO(2), but no relation was observed between UVA absorbency and OH radical formation. The cytotoxicity of TiO(2)-UVA irradiation was determined against Chinese hamster ovary (CHO) cells and a significant relationship was obtained between the cytotoxicity and the OH generation. Measurement of the amount of OH radical production by UVA irradiation with ESR is needed to clarify the effect of crystal form or sizes of TiO(2) on OH radical production and cytotoxicity.

Animals↗

PubMed2001

E' centers in amorphous SiO(2) revisited: a new look at an old problem.

We present theoretical evidence that the paramagnetic E' defect centers in amorphous silicon dioxide (a-SiO(2)) do not have the same microscopic structures as those well-defined in the corresponding crystalline counterparts such as alpha-quartz. We then present alternative models of some paramagnetic defects that account for the underlying experimental features of the E'-center variants in a-SiO(2). We suggest that our new model should take the place of the conventional defect model of a-SiO(2).

Journal Article↗

PubMed2001

Structure and generation mechanism of the peroxy-radical defect in amorphous silica.

We provide a new model of the peroxy-radical defect in amorphous silica on the basis of quantum-chemical calculations applied to clusters of atoms to model the defect. In this model, the 29Si hyperfine splittings of the peroxy radical arise from a single silicon, in agreement with the previous experimental findings. Furthermore, we show that the present model of the peroxy radical is consistent with the diffusion-limited anneal mechanism of the E'gamma center, although our model of the E'gamma center is different from the conventional charged oxygen vacancy model.

Journal Article↗

PubMed2001

Mechanism of interconversion among radiation-induced defects in amorphous silicon dioxide.

We here present a series of ab initio quantum-chemical calculations on clusters of atoms modeling several oxygen-deficiency-related defects in amorphous silica and illustrate how these defect centers will change their atomic configurations upon photoionization. We first give theoretical evidence that structural conversion from a neutral oxygen monovacancy to a divalent Si defect is possible, explaining the observed photoluminescence properties associated with these defects.

Journal Article↗

PubMed2000

Mechanism of photoinduced changes in the structure and optical properties of amorphous As2S3.

We propose a mechanism of photostructural changes in amorphous As2S3 ( a-As2S3) on the basis of ab initio molecular orbital calculations on clusters of atoms modeling the local structure of the amorphous system. We have found that trigonal AsS3 pyramidal units can be transformed into a fivefold coordinated As site having four As-S bonds and one As-As bond via a photoionization process. This photoinduced coordination defect center exhibits a lower photoabsorption energy as compared with the usual pyramidal structure, explaining the observed photodarkening effect of a-As2S3.

Journal Article↗

PubMed2000

Structure and formation mechanism of Ge E (') center from divalent defects in Ge-doped SiO2 glass

We have performed ab initio quantum-chemical calculations on clusters of atoms modeling a divalent Ge defect in Ge-doped SiO (2) glasses. It has been found that the divalent Ge defect interacts with a nearby GeO (4) tetrahedron, forming complex structural units that are responsible for the observed photoabsorption band at approximately 5 eV. We have shown that these structural units can be transformed into two equivalent Ge E' centers by way of the positively charged defect center.

Journal Article↗

PubMed2000

Evaluation of persistence of ductus venosus with tc-99m DTPA galactosyl human serum albumin liver scintigraphy and I-123 iodoamphetamine per-rectal portal scintigraphy.

Tc-99m DTPA galactosyl human serum albumin (Tc-99m GSA) hepatic scintigraphy was performed in two patients with patent ductus venosus before and after operation. To evaluate the portosystemic shunt flow, per-rectal portal scintigraphy with I-123 N-isopropyl-p-iodoamphetamine (IMP) was undergone in the same period. The portosystemic shunt indices (PSS index) were decreased from 67.9% to 7.3% in the patient 1, and from 77.3% to 22.7% in the patient 2, respectively. Quantitative indices of Tc-99m GSA hepatic scintigraphy improved dramatically in both patients. Under microscopic examination, nearly all the hepatic cells showed signs of severe fatty degeneration. After the operation, the severe fatty degeneration was alleviated and all the hepatic cells appeared normal. I-123 IMP per-rectal portal scintigraphy and Tc-99m GSA hepatic scintigraphy were useful in evaluating the quantitative shunt flow of the persistent ductus venosus and its hepatic functional reserve.

Amphetamines↗

PubMed2000

An occipital encephalocystocele involving both sides of the lateral ventricles.

We reported a rare case of an occipital encephalocystocele linked by bilateral posterior horns of the lateral ventricles. The subject was a newborn girl with a large occipital cephalocele (6 x 9 cm in diameter) covered with alopetic skin. Cerebrospinal fluid leakage was not observed. The fontanel was soft, but a characteristic flat forehead was noted. Neither neurological deficits nor cardiopulmonary dysfunctions were evident at birth. Magnetic resonance images revealed that the sac contained the occipital lobes and that the cavity was linked by bilateral posterior horns. Agenesis of the corpus callosum and dysgenesis of the falx cerebri were associated. Fifteen days after birth, the cephalocele was removed surgically. Cutting sections revealed that the cephalocele contained enlarged bilateral posterior horns and cerebral hemispheres. The postoperative course was uncomplicated by hydrocephalus or infection, and the patient was discharged without any neurological deficit 22 days after surgery. Her milestone was survival; and at present 12 months after surgery, she is alive with moderate developmental retardation.

Abnormalities, Multiple↗

PubMed2000

[Validation of simple analytical equipment for arsenic].

In order to improve the arsenic test method, we investigated the effect of temperature, solar light and masking ions on that test method. As the results, we found that the solar light gave the big damage to the colored reaction on the method. In addition, on comparing the improved method with the arsenic test method of Merckoquant kit by using the water containing 0.01 ppm arsenic as the Japanese guideline for the drinking water, the improved method gave the better analytical value than Merckoquant kit that was not sufficiently determined.

Arsenic↗

PubMed1999

A molecular phylogeny of Lilium in the internal transcribed spacer region of nuclear ribosomal DNA.

Phylogenetic relationships among 55 species of Lilium, Cardiocrinum giganteum, and Nomocharis saluenensis were inferred from nucleotide sequence variations in the internal transcribed spacer (ITS) regions of 18S-25S nuclear ribosomal DNA. The phylogeny derived from ITS sequences estimated using maximum-likelihood methods indicated that (1) most of the species construct their own clade according to the classification based on morphological features at the section level; (2) section Daurolirion is not independent of Sinomartagon, and it is appropriate to integrate two sections as Sinomartagon; (3) it is appropriate that L. henryi and L. bulbiferum are classified into subsection 6a and Sinomartagon-Daurolirion, respectively; (4) subsection 6b is much closer to Sinomartagon than subsection 6a and Archelirion, and it arose directly from Sinomartagon; and (5) Lilium is much closer to Nomocharis than Cardiocrinum. Phylogenetic estimation using sequences of the ITS region is suitable at the levels of genus, section, and most of subsection.

Base Sequence↗

PubMed1999

Surgical indications for patients with hyperammonemia.

BACKGROUND/PURPOSE: The authors surgically treated seven of eight patients with congenital portosystemic shunt and hyperammonemia. This entity is uncommon in children. METHODS: The patients included five boys and three girls with a mean age of 8 years (range, 7 months to 24 years). Preoperative symptoms included hyperammonemia. Hepatic encephalopathy was evident in five patients. Diagnosis and assessment were made by ultrasound scan, magnetic resonance imaging (MRI), angiography, and 123 I-iodoamphetamine per-rectal portal scintigraphy. Surgical banding was done for five patients and transvenous coil embolization for two. One patient was not a surgical candidate because there were no intrahepatic portal veins. RESULTS: In four of the five patients treated using surgical banding, and in both patients who underwent coil embolizations, hyperammonemia and clinical symptoms improved soon after surgery. However, in the remaining patient, hyperammonemia worsened after surgery, and reoperation was needed because of a severe portal hypertension, possibly caused by malconformation of hepatic veins. CONCLUSIONS: For patients with congenital portosystemic shunt, early diagnosis and surgery are needed to prevent damage to central nerves caused by persistent hyperammonemia. Maldevelopment of the intrahepatic portal veins is a surgical option, if the patient has a normal liver architecture, but malconformation of hepatic veins or severe anomalies such as cardiac defects would rule out surgical intervention.

Adolescent↗

PubMed1999

The long-term prognosis of congenital portosystemic venous shunt.

Congenital portosystemic venous shunt (PSVS), considered to be a rare disease, can lead to hepatic encephalopathy (HE). With improvements in diagnostic imaging techniques, the number of infants and children with documented PSVS has increased. The natural course of the disease and indications for surgical closure of the shunt vessel have not been well defined. We reviewed 51 cases of congenital PSVS in Japan; 34 patients had an intrahepatic PSVS, and 17 had an extrahepatic PSVS. There were 12 patients with HE at the time of diagnosis. The frequency of HE increased in subjects over 60 years of age. Children with HE had a shunt ratio exceeding 60%. When the shunt ratio was less than 30%, HE did not occur. Twenty of 28 patients under the age of 15 years had hypergalactosemia at the time of neonatal screening. Part of the congenital intrahepatic PSVS spontaneously closed. Surgical closure of a PSVS may be an approach expected to prevent HE when the shunt ratio exceeds 60%.

Adolescent↗

PubMed1999

Effect of FK 506 and lipo prostaglandin E1 on heart allograft survival in rats.

FK 506 (FK) has a strong immunosuppressive effect, but a low-grade, dose-dependent nephrotoxicity and diabetogenicity, which means that reducing the dose of FK is of considerable interest. Lipo-prostaglandin E1 (LPGE1) is a preparation of PGE1 that has potent immunosuppressive properties, and its duration of action is longer than that of ordinary PGE1. The purpose of this study was to investigate whether LPGE1 can enhance the immunosuppressive effect of FK. Heterotopic cardiac transplantations to the neck vessels were performed, and recipient rats were treated with intramuscular injections of FK and LPGE1 once daily for 10 days. All grafts without any treatment were rejected within 14 days. In comparison, the FK doses of 0.07, 0.2 and 1.0 mg/kg/day for 10 days significantly increased the long-term graft survival (>100 days) to 8%, 44% and 100%, respectively. The addition of LPGE1 to the first two dosages caused a further significant increase in the graft survival, to 18% and 80%, respectively, when compared with the control. LPGE1 appears to enhance the immunosuppressive effect of FK.

Alprostadil↗

PubMed1999

[Current appraisal of endoscopic thoracic sympathectomy: results of the national questionnaire surgery].

A questionnaire survey was performed in order to investigate the current status of endoscopic thoracic sympathectomy in Japan. Four hundred and twenty-nine (429) university, national or public hospitals with a minimum of 400 beds were included. A total of 248 of these hospitals responded. Among them 63 (25%) performed this procedure. The total of the cases was 1116. The number of access port and the technique for defunctioning the sympathetic chain were broadly divided into three methods. These methods were equally carried out among the departments. The clinical results were judged as satisfactory in the great majority of patients and the frequency of complications was low. On the other hand, the overall incidence of compensatory sweating remained relatively high and accumulated as the number of cases increased. But the reported frequency differed strikingly from hospital probably for lack of an objective way of quantifying following sympathectomy. Although overall complications were infrequent, the need for conventional thoracotomy to stop bleeding occurred in some cases. Therefore even this simple endoscopic operation demands the utmost surgical care, skill and experience. A few recurrences of preoperative symptoms were seen in the follow-up suggesting that all patients must be continually monitored after the operation.

Endoscopy↗