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Biomedical subjects

T Imamura

Publications and source records attributed to T Imamura.

At least 451 records · Page 25Linked to original sources
PubMed1991

Determination of kerosene and light oil components in blood.

A sensitive and rapid method to analyse fuel components in blood from rats exposed to kerosene or light oil vapour was developed by making use of capillary gas chromatography/mass spectrometry. The aliphatic hydrocarbons with carbon numbers 8-10 and aromatics such as toluene, xylene, 3- and 4-ethyltoluene and trimethylbenzenes were clearly detected in blood from rats exposed to kerosene or light oil vapour, using the head-space method combined with the salting-out technique. The concentration ratio of pseudocumene to toluene in blood exposed to light oil was higher than that in the case of exposure to kerosene. The lower limits of detection were 50 pg and 1 ng in toluene and pseudocumene, respectively. Our suggestion is that this method is useful in forensic investigations to detect fuel components in blood and for the purposes of differentiating kerosene and light oil in blood tissues.

Animals↗
PubMed1991

Forensic analysis of triazolam in human tissues using capillary gas chromatography.

A reliable and sensitive method has been developed to assess the concentrations of the hypnotic drug triazolam in human tissues, including putrefied tissues. The method involves a 3-step solvent extraction, clean-up on a silica gel column and gas chromatography using a nitrogen phosphorus detector and a capillary column. Estazolam was used as an internal standard. The calibration curve was linear over the concentration range 1 ng/g-1 microgram/g and the lower limit of detection was 0.5 ng/g. A forensic study was performed on the toxicological effects of triazolam using putrefied tissues.

Adult↗
PubMed1991

Primary venous aneurysm of the forearm in a child.

A 5 year old girl who presented with two bluish, cystic masses in her right forearm was shown on ultrasonography to have two localized saccular dilatations of the right radial vein. This led to the suspicion of venous aneurysms which was later confirmed by venography. They were finally excised because of the gradual increase in size and pain she had experienced over the previous two months.

Aneurysm↗
PubMed1991

Contact with basement membrane heparan sulfate enhances the growth of transformed vascular endothelial cells, but suppresses normal cells.

Modulation of vascular endothelial cell growth by basement membrane heparan sulfate was investigated using four lines of normal and transformed cells. The growth of transformed endothelial cells, but not normal cells, on reconstituted basement membrane was severely suppressed when heparan sulfate, one of the components of the membrane, was specifically degraded by an enzyme, heparitinase. Similarly, when cells were grown on surfaces coated with heparan sulfate, as little as 60 pg/cm2 of heparan sulfate caused growth enhancement of transformed cells, but suppression of normal cells. These results together with our previous observations (IMAMURA, T and MITSUI, Y. (1987) Exp. Cell Res., 172: 92-100) argue that transformed cells have reversed a mechanism by which basement membrane heparan sulfate functions as a physiological suppressor for the growth of normal endothelial cells.

Animals↗
PubMed1991

Purification and some properties of inducible lysine decarboxylase from Vibrio parahaemolyticus.

Inducible lysine decarboxylase from Vibrio parahaemolyticus AQ 3627 was purified to apparent homogeneity and characterized. The enzyme displayed a molecular weight of 531000 by gel filtration and 79000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme required pyridoxal phosphate as a cofactor, and the pH optimum was 5.5. The Km value for L-lysine was 3.2 mM, and the enzyme was inhibited by 6-aminocaproic acid and alpha-fluoromethyl analogs of cadaverine. delta-Hydroxylysine and S-aminoethyl-L-cysteine was active as substrates to a lesser extent than L-lysine. The amino-terminal amino acid sequence was determined to be Met-Asn-Ile-Phe-Ala-Ile-Leu. These properties were compared with those of other bacterial lysine decarboxylases.

Amino Acid Sequence↗
PubMed1991

[Monoamine oxidase inhibitory effects of pentanthrene type heterocyclic compounds].

Pentanthrene type heterocyclic compounds, which contain oxazole, isoxazole, oxadiazole, thiazole, isothiazole, thiadiazole or pyrrole ring as C-ring, and naphthalene, quinoline, isoquinoline or quinoxaline ring as A.B-ring, were prepared, and their monoamine oxidase (MAO) inhibitory activities were examined. As expected from our previous investigation on the structure-activity relationship of this series, most of them showed strong inhibitory potency to both MAO-A and MAO-B. However, a few indicated highly selective inhibition for either of MAO subtypes.

Animals↗
PubMed1991

Establishment of vascular endothelial cell lines in a serum-free culture and the discovery of endothelin and a vasoactive intestinal contractor (VIC).

Immortal vascular endothelial cell lines were established and utilized for the production of an endothelium-derived contraction factor (EDCF) in a serum-free medium. After the discovery of Endothelin (21 amino acid peptide, ET) as an EDCF, a prepro ET cDNA isolated from human tissue was used to examine the expression of ET and its regulation in human endothelial cells. A gene family of ET was shown in mouse by using prepro ET cDNA as a probe. Thus, a novel peptide, Vasoactive Intestinal Contractor (VIC) homologous to ET was deduced from the sequence of one of these genes. VIC was confirmed to induce vasocontraction as well as intestinal contraction. Northern blot analysis indicated that this gene was expressed in the intestine but not in endothelial cells. A cloning and sequencing of prepro VIC cDNA from mouse intestine suggest that a VIC-like peptide, as well as VIC, are co-synthesized by cleavage from prepro VIC with 160 amino acids.

Amino Acid Sequence↗
PubMed1991

Enzymatic investigation for delayed-type hypersensitivity reaction. Assay for thrombin and plasmin activities in tuberculin reaction sites.

Induration is a prominent feature of delayed hypersensitivity reaction (DHR) and is associated with fibrin deposition. To determine whether thrombin and plasmin mediate the development of induration, we examined guinea pig skin extracts of tuberculin reaction sites for the protease activities. To measure their low activities without inactivation by the inhibitors in the extracts, fluorogenic peptide substrates specific to each of the proteases were used. Because thiol proteases in the extracts hydrolyzed the substrates, the two serine protease activities were selected using a serine protease inhibitor. The extracts contained alpha 2-macroglobulin (alpha 2-MG)-trapped thrombin that hydrolyzes the substrate, but no alpha 2-MG-trapped plasmin. To exclude alpha 2-MG-trapped thrombin activity, the extract treated with 0.2 M methylamine was incubated for two hours and the residual activity was excluded from the initial thrombin activity. Thrombin activity paralleled increasing intensity of induration, and plasmin activity was associated with the reduction of induration. Neither induration nor an increase of protease activity was observed at control sites. The results show that thrombin and plasmin mediate the development of induration probably by regulating fibrin deposition in DHR sites and that the present method can measure the protease activities in biological fluids and tissue extracts.

Animals↗
PubMed1991

[Single photon emission CT in diagnosis of herpes simplex encephalitis--fronto-parietal hypo-accumulation associated with temporal hyper-accumulation].

Single photon emission CT (SPECT) using 123I-iodoamphetamine and magnetic resonance imaging (MRI) were performed in acute, subacute and chronic stages of a herpes simplex encephalitis (HSE). On the 5th day after onset, SPECT showed left temporal hyperaccumulation associated with decreased accumulation in ipsilateral posterior frontal and anterior parietal lobes. These altered accumulations were normalized on the 26th day, and a broad hypoaccumulation appeared in left temporal and surrounded area on the 91st day. The lesion in MRI was restricted to left temporal lobe and insula throughout the clinical course. Several authors reported temporal hyperaccumulation of lipophilic tracer in SPECT study of acute HSE, but its mechanism is controversial. Some postulate local hyperperfusion and others infer altered binding site of tracer. The fronto-parietal hypoaccumulation observed in our acute SPECT study suggests steal phenomenon in the territory of ipsilateral internal carotid artery, and supports temporal hyperperfusion as the origin of increased accumulation.

Amphetamines↗
PubMed1991

[A case of adenoma of the nipple with breast cancer].

Adenoma of the nipple is an uncommon lesion which can be mistaken clinically for Paget's disease and pathologically be misinterpreted as an adenocarcinoma. We recently experienced a case of very rare adenoma of the left nipple with left breast cancer. The patient was a 42-year-old, married woman with a firm, partially erosive lump measuring 12 X 12mm in her left nipple and with a left breast lump. Biopsy revealed the breast lump invasive ductal carcinoma and lump of the nipple was adenoma. Modified radical mastectomy was carried out. It is important to bear this rare lesion in mind and perform a thorough examination before making a diagnosis of a lump in the nipple.

Adenoma↗
PubMed1991

[Histopathological examination of a case of Behçet's disease with aortic regurgitation].

Cardiac involvement in Behçet's disease is quite uncommon. We report a case of Behçet's disease with aortic regurgitation of which histology was examined. A 56-year-old male came to our hospital with a complaint of right cervical pain. Diagnosis of aortic regurgitation was made by echocardiography, cardiac catheterization and aortography. As the cardiac lesion worsened, the operation of the aortic valve replacement was performed. On pathological examination, there was marked fibrous thickening on the aortic valve and the rupture of elastic tissue in the media of aortic wall. There was no history of rheumatic fever nor syphilis, and dilation of orifice of the aorta was not observed. Thus these changes were probably due to Behçet's disease itself.

Aortic Valve Insufficiency↗
PubMed1991

[Clofibrate treatment of psoriasis with hypertriglycemia--clinical, histological and laboratory analysis].

Abnormalities of triglyceride (TG) metabolism are considered to play an important role in pathogenesis of psoriasis. Two psoriatic patients with hypertriglycemia were treated with 750 mg of oral Clofibrate daily. While they were treated, both patients showed improvement of psoriasis. Upon cessation of treatment the lesions returned. During the treatment, levels of serum TG, apolipoprotein C-III (apo C-III), and apo E were reduced significantly. The analysis of serum fatty acids revealed a change in the level of linoleic acid. The serum linoleic acid level, which had been low in both cases before the treatment, increased in one case and decreased in other during the treatment. In the biopsy specimen from the post-treatment plaque, both capillary proliferation and endothelial swelling in the dermis were less prominent. There was a moderate reduction in the number of lymphocytic cells, and an increase in that of histiocytic cells. Clofibrate treatment improved TG metabolism and the histological and clinical findings in the psoriatic lesion.

Adult↗
PubMed1991

Postmortem changes of ingested thinner components in tissues.

Postmortem changes of thinner components in body tissues were examined in rats, orally given 1 ml of standard thinner solution, which was prepared by mixing toluene, ethyl acetate and isobutanol in the proportion of 8:1:1. Analysis was made by gas chromatography combined with the head space method. Three thinner components and ethanol, a metabolite of ethyl acetate, were detected in the gastric contents of all rats up until 48 hours after death. An increase in the concentration of toluene was found in the blood, lung, kidney, liver, brain and abdominal muscle with the lapse of time. On the other hand, no changes were observed in the thigh muscle throughout the 48-hour period. Isobutanol showed a similar increasing pattern to toluene, with little or no changes in the brain or in the thigh muscle. Ethyl acetate was not detected in any tissues throughout the study but it was found in the gastric contents. The results indicate that every thinner component ingested, gradually diffuses into the surrounding tissues through the stomach wall after death, and that only muscle tissue remote from the abdominal cavity, together with the gastric contents, should be analyzed for a correct diagnosis of thinner ingestion.

Administration, Oral↗
PubMed1991

[ARDS: circulatory factors and their evaluation].

ARDS occurs in patients with no underlying pulmonary diseases, induced by stresses, such as lung injury, acute pancreatitis or infections. It is an acute respiratory disorder which manifests as acute dyspnea, hypoxemia and lowered pulmonary compliance. Greene et al, used balloon pulmonary angiogram (BOPA) as diagnostic tool to morphologically observe the pulmonary disorder. To study the dynamic pulmonary circulation and morphology of the peripheral pulmonary artery of ARDS, we performed this method for acute cardiac failure and ARDS patients. Pulmonary hemodynamic changes in ARDS revealed mild pulmonary hypertension and increased PVR, while C.I. and PCWP remained within a normal range. The findings of BOPA in ARDS showed that the frequency of PAFD correlated with the the presence of an elevated PVR and DIC, and pulmonary vasoconstriction was detected by measurement of PA diameter (B/A2).

Aged↗
PubMed1991

[Right ventricular function evaluated by thermodilution method in patients with chronic pulmonary diseases].

The right ventricular ejection fraction (RVEF) is an objective evaluation of the right ventricular systolic function. Recently a rapid-response thermister pulmonary artery catheter which measures RVEF and stroke volume (SV) was introduced. With this new method, RVEF and the right ventricular volumes (RVV) were measured in patients with chronic pulmonary diseases (CPD) and normal subjects. In addition, to evaluate the validity of this method, the data was compared with Kr81m perfusion method. The RVEF and the RVV of CPD patients were also compared with pulmonary hemodynamic data. There was a good correlation between the RVEFs obtained by the Kr81m perfusion method and the TD method. (r = 0.71, p less than 0.001). There was a tendency towards a low RVEF in patient with CPD with pulmonary hypertension (PAm greater than 20 mmHg) or high pulmonary vascular resistance (PAR greater than 160 dyne/sec/cm-5) and the RVV increased in the same group. These results suggested that the right ventricle was unable to respond to the increase of afterload in the CPD group and the evaluation of RVEF and RVV in patients with CPD using the new TD method was valuable for assessing the right ventricular function.

Adult↗