Search PubMed⌕ Search

Biomedical subjects

N Ikeda

Publications and source records attributed to N Ikeda.

At least 163 records · Page 9Linked to original sources
PubMed1998

[Relative valve area stenosis after replacement of a Starr-Edwards mitral valve (model 6520) for corrected TGA (S, L, L): report of a case].

The patient was a 38-year-old man who had undergone mitral valve replacement with a Starr-Edwards disc valve (model 6520, 3 M, phi 30 mm, functional valve area: 2.85 cm2) at the age of 15 years for TR combined with corrected TGA. He developed dyspnea on exertion and palpitations at the age of 30 years, and paroxysmal supraventricular tachycardia appeared at the age of 35 years. Cardiac catheterization revealed that the PCWP was 30 mmHg and the TVA was 1.1 cm2, and a diagnosis of stenosis of the prosthetic valve was made. Thus, replacement of the Starr-Edwards disc valve using a BICARBON double leaflet valve (phi 27 mm, functional valve area: 2.85 cm2) was performed. The operative findings of the Starr-Edwards disc valve revealed a normal appearance and no pannus growth. Postoperative echocardiography and cardiac catheterization found that the TVA was 3.7 cm2 and the PCWP was 13 mmHg. The actual valve area of the disc valve sewn on the ventrical, which was anatomically RV construction might have been smaller than the ideal area; however, the double leaflet valve proved efficient in our patient. This case report serves to demonstrate that because of the postoperative difference in measurement between the actual valve area and the prostheticin ball or disc valve, patients undergoing mitral valve replacement must be followed up carefully.

Adult↗
PubMed1997

Distribution of drugs in various tissues in a brain dead man.

We examined the distribution of drugs in a 49-year-old brain-dead man. Our objective was to determine the possibility of diagnosing how and at what point the patient became brain dead. The presence of mepivacaine, pentazocine, lidocaine and thiamylal in various tissues, including seven regions of the brain were confirmed, using gas chromatography/mass spectrometry. Tissue-to-blood concentration ratios of mepivacaine, pentazocine and lidocaine in the brain were higher than these ratios in other tissues, while ratios of thiamylal were lower. Therefore, cerebral blood flow was likely to have ceased between the administration of the former drugs and that of the latter drug, in agreement with clinical records. Among seven regions of the brain, the ratios of the former three drugs were high in occipital and parietal lobes, and were low in the cerebellum and medulla oblongata. On the other hand, the ratios of the latter drug were high in the cerebellum and the medulla oblongata. Therefore, cerebral blood flow presumably ceased first in occipital and parietal lobes, and last in the cerebellum and the medulla oblongata. Based on these results, assessment of concentrations of drugs in human tissues, including various regions of brain is useful to determine the time and progression of brain death.

Analgesics, Opioid↗
PubMed1997

Nonideal Mixing in Adsorbed Film and Micelle of Ionic-Nonionic Surfactant Mixtures

The surface tension of aqueous solutions of dodecylammonium chloride-octyl methyl sulfoxide (OMS) and dodecyltrimethylammonium bromide-OMS mixtures was measured as a function of the total molality of surfactants and the composition of OMS. The results were analyzed according to our thermodynamic procedure; the phase diagrams of adsorption and micelle formation and the diagram illustrating the composition relation between the micelle and the adsorbed film at the critical micelle concentration were drawn. The activity coefficient and excess Gibbs energy in the adsorbed film and the micelle were defined and then evaluated from the phase diagrams. They were found to give useful information on the deviation from ideal mixing and intermolecular interaction in the adsorbed film and micelle. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Simple and rapid determination of enflurane in human tissues using gas chromatography and gas chromatography-mass spectrometry.

A simple, rapid and reliable method was devised to determine the levels of enflurane in human tissues, using gas chromatography and gas chromatography-mass spectrometry. 1,4-Dioxane was used as an internal standard (I.S.). Enflurane and the I.S. were extracted from 0.25 g of body tissues using an automatic headspace sampler and 1 ml of headspace gas was injected into the gas chromatograph. Enflurane was analyzed qualitatively by gas chromatography-mass spectrometry and quantitatively by gas chromatography with a flame-ionization detector. The calibration curves in all tissues examined were linear in the concentration range 1-100 microg/0.25 g. The lower limit of detection was 200-300 ng/0.25 g. The accuracy and precision of this method were evaluated at two different concentrations, 1 and 20 microg/0.25 g. The coefficient of variation ranged from 3.4-13.4%. We used this method to determine the presence of enflurane in tissues from an autopsied individual who died suddenly during extirpation of a malignant tumor.

Anesthetics, Inhalation↗
PubMed1997

Purification, characterization and cloning of a novel variant of the superantigen Yersinia pseudotuberculosis-derived mitogen.

The novel superantigen designated as Yersinia pseudotuberculosis-derived mitogen typeB (YPMb) was purified from the cell lysate of Y. pseudotuberculosis O:6 strain (R-104). Proliferative response of human peripheral blood mononuclear cells to the purified YPMb was detectable at a concentration of as low as 1 pg/ml, that is comparable to the previously documented YPM (YPMa). The Vbeta repertoire specificity (3, 9, 13.1 and 13.2) of YPMb was also the same as that of YPMa. A gene (ypmB) encoding YPMb was cloned and its nucleotide sequence was determined. The open reading frame (ORF 453 bp) of the ypmB encodes a protein with 150 amino acid residues, though the precursor protein of YPMa consists of 151 amino acid residues. There is a nucleotide sequence homology of 88.9% between ypmB and ypmA. The low homology in the downstream of the structural gene between ypmB and ypmA and the difference in the GC content in the ORF of ypmB and ypmA from that of the base usage of Y. pseudotuberculosis suggest that the ypm gene originates from another organism. The alignment of the amino acid sequences of mature proteins of YPMb and YPMa revealed that there is 83% homology (108 amino acid residues are identical). Between YPMa and YPMb, the central region is less homologous than the N- and C-terminal regions. Based on the functional similarity of two superantigen molecules, the less homology suggested that the central region is less important for the function of both YPM molecules.

Amino Acid Sequence↗
PubMed1997

Thermodynamic Study on the Surface Formation of the Mixture of Water and Ethanol

The formation of the water + ethanol mixture/air surface was studied by measuring the surface tension as a function of temperature and the mole fraction of ethanol in the mixture. The surface composition, the entropy Deltas , and energy Deltau of surface formation were evaluated by adopting the thermodynamic equations. It was shown that the surface was enriched in ethanol molecules compared with the bulk solution. The values of Deltas and Deltau were examined closely by estimating the contribution from the nonideal mixing in the bulk solution and that at the surface to Deltas and Deltau . It was concluded that the surface formation is driven by entropy at lower x 2 and by energy at higher x 2 , respectively, and that the surface formation becomes more energetically favorable with rising temperature.

Journal Article↗
PubMed1997

Kinetic evaluation of beta-neoendorphin hydrolysis by the somatic and testicular isozymes of human angiotensin-converting enzyme.

Angiotensin-converting enzyme (ACE) has both somatic and testicular isozymes, the former possessing two catalytically active domains, amino-terminal and carboxyl-terminal, while the latter has only the carboxyl-terminal one. We compared hydrolysis processes of the nonapeptide beta-neoendorphin by the two isozymes of human ACE. Both isozymes hydrolyzed the peptide to Tyr1-Gly2-Gly3 by the sequential removal of carboxyl-terminal dipeptides in three consecutive steps. The rate constant values for the second step, conversion of beta-neoendorphin1-7 to Leu-enkephalin, by the somatic isozyme in the presence of 10 or 200 mM NaCl were 4-fold higher than those for the first step, conversion of beta-neoendorphin1-9 to beta-neoendorphin1-7. The k(cat) values of the somatic isozyme for beta-neoendorphin1-7 were 2-fold higher than those for beta-neoendorphin1-9, indicating that beta-neoendorphin1-7 is more rapidly hydrolyzed than beta-neoendorphin1-9. The rate constant value for the second step at 10 mM NaCl was 5-fold higher than that for the testicular isozyme. Similar extent of difference was also observed in k(cat) values for beta-neoendorphin1-7 between the two isozymes. These results suggest that the amino-terminal domain of the somatic isozyme mainly contributes to the conversion of beta-neoendorphin1-7 to Leu-enkephalin at a low NaCl concentration. Optimal chloride concentrations for the individual steps of beta-neoendorphin1-9 hydrolysis differed between the two isozymes.

Humans↗
PubMed1997

A video-assisted thoracoscopic surgical technique for interruption of patent ductus arteriosus.

We describe herein a technique for patent ductus arteriosus (PDA) closure using a method of video-assisted thoracoscopic surgical (VATS) interruption derived from video-assisted endoscopic surgery. This technique of repair was performed on five patients with a mean age of 3 years and a mean weight of 13.7 kg during 1994 and 1995. Under general anesthesia, two 10-mm trocars and two or three 5-mm trocars were inserted through the left thoracic wall. A video camera and specially designed surgical tools including scissors, dissectors, and a clip applicator were then introduced. The ductus was dissected, and two titanium clips were applied to interrupt the ductus completely. Successful closure of the PDA by this video-assisted technique was achieved in all patients. The only complication which developed in one patient was hoarseness for 2 weeks postoperatively. The hospital stay ranged from 7 to 12 days and there were no serious complications or deaths. There results indicate that video-assisted thoracoscopic surgical interruption is a safe and effective technique for achieving closure of PDA.

Child, Preschool↗
PubMed1997

Detection of triazolam in skeletal remains buried for 4 years.

Analyses of the hypnotic triazolam from the remains of two human skeletons buried underground for 4 years were made for purposes of confirmation. The bone marrow and mummified muscle were digested with 2 M sodium hydroxide, efficiently extracted using a 3-step solvent extraction procedure, and selectively analyzed by gas chromatography/mass spectrometry with the negative ion chemical ionization mode. Estazolam was the internal standard used. Triazolam was detected in all the samples; the concentrations were 0.36 ng/g in the bone marrow of one victim, and 0.37 and 5.5 ng/g in the bone marrow and mummified muscle of the other victim. This method should prove useful for determination of triazolam in extensively decomposed bodies.

Bone Marrow↗
PubMed1997

A national epidemiological survey of oral mucosal lesions in Malaysia.

The prevalence of oral mucosal lesions in Malaysia was determined by examining a representative sample of 11,707 subjects aged 25 years and above throughout the 14 states over a period of 5 months during 1993/1994. A two-stage stratified random sampling was undertaken. A predetermined number of enumeration blocks, the smallest population unit in the census publication, was selected from each state. With the selected enumeration block, a systematic sample of living quarters was chosen with a random start. The survey instrument included a questionnaire on sociodemographic characteristics and a clinical examination. The clinical examination was carried out by 16 specially trained dental public health officers and the diagnosis calibrated with a final concordance rate of 92%. The age in the sample ranged from 25 to 115 years with a mean of 44.5+/-14.0. The sample comprised 40.2% males and 59.8% females; 55.8% were Malays, 29.4% Chinese, 10.0% Indians and 1.2% other ethnic groups. Oral mucosal lesions were detected in 1131 (9.7%) subjects, 5 (0.04%) had oral cancer, 165 (1.4%) had lesions or conditions that may be precancerous (leukoplakia, erythroplakia, submucous fibrosis and lichen planus) and 187 (1.6%) had betel chewer's mucosa. The prevalence of oral precancer was highest amongst Indians (4.0%) and other Bumiputras (the indigenous people of Sabah and Sarawak) (2.5%) while the lowest prevalence was amongst the Chinese (0.5%).

Adult↗
PubMed1997

Vertebral artery dissection not detected by initial angiography--case report.

A 57-year-old male presented with subarachnoid hemorrhage caused by vertebral artery dissection. The first cerebral angiogram on the day of ictus found minimal caliber change with lower contrast density at the V4 segment, but repeat angiography showed typical segmental narrowing of the artery on the 14th day. Repeat angiography with magnetic resonance imaging in the subacute stage would be useful to identify the cause of "angiogram-negative" subarachnoid hemorrhage.

Cerebral Angiography↗
PubMed1997

[Serum levels and in vitro production of IL-5 in children with bronchial asthma].

IL-5 play important roles in inflammatory responses in bronchial asthma, but little is known about serum levels and in vitro production of IL-5 in childhood bronchial asthma. We further examined serum IL-5 levels in children with bronchial asthma and the controls. IL-5 in serum was detected in all of asthmatic and disease-free individuals. Its values during asthma exacerbation were significantly higher than during remission of asthma. Serum IL-5 values did not significantly differ among groups divided by asthma severity. We studied IL-5 production by peripheral blood mononuclear cells cultured with or without Dermatophagoides farinae (Df) in children with mite allergy. IL-5 concentrations in culture supernatant from after stimulation with Df were significantly higher than those from asthmatic patients without stimulation and from the control subjects. In contrast, IL-5 levels in culture media from the controls were not significantly different between with and without stimulation with Df. Our results suggest that IL-5 may play roles in the pathogenesis of bronchial asthma.

Asthma↗
PubMed1997

[Pulmonary infection with Mycobacterium kansasii presenting as solitary nodule shadow in the left anterior basal segment].

A 71-year-old man was admitted to our hospital for evaluation of a solitary pulmonary nodule in the left lower lung field. He had been treated for Parkinson's disease for two years, and had no respiratory symptoms on admission. No abnormal findings were detected in laboratory tests on admission, and Mantoux's skin test was negative. A postero-anterior chest roentgenogram, a conventional tomogram, and a computed tomogram showed that the nodule was located in the left anterior basal segment (S8). The nodule was not calcified, the contour was clear but irregular, and pleural indentation could be seen, so the nodule was strongly suspected to be a primary malignant lung tumor. Because two attempts at transbronchial lung biopsy and bronchial brushing and washing were of no diagnostic value, a thoracotomy was done. The lesion was found in the subpleural region of the left S8 with pleural indentation, and it was partially resected. The nodule was elastic, soft, and filled with suppurative fluid. Histopathologic examination of the nodule revealed epithelioid cell granuloma. A smear test of the fluid was negative but a culture was positive for mycobacteria; which were identified as Mycobacterium kansasii. Rifampicin and isoniazid were administrated to the patient for 1 year. Two years after the operation, the patient was asymptomatic.

Aged↗
PubMed1997

[Clinical manifestation of volatile solvent psychosis].

To identify symptomatological characteristics of solvent psychosis, 9 cases of chronic thinner intoxication with psychitaric evidence during the abstinent period are studied. The results were as follows: 1) During intoxication, 7 cases had visual hallucinations and 3 cases had auditory hallucinations. 2) Eight cases had irritabilities or mood disturbances without thinner intoxication. 3) Four cases had convulsions or delirium which were observed only in the withdrawal period, suggesting that these symptoms might be withdrawal signs of thinner dependence. 4) Six cases had Schneiderian first rank symptoms such as auditory hallucinations (i.e. voices commenting, voices arguing), delusions of control (withdrawal of thought, thought insertion, influence of thought) and delusional perception. Hallucinations that appeared in acute intoxication with thinner in 5 of the 6 cases, were second rank symptoms. Five of the 6 cases did not show negative symptoms (i.e. blunting of thought) and they could maintain good emotional contact with other. Symptoms of these 5 cases were different from those of schizophrenia or the flashback phenomenon of thinner dependence. These cases suggest that Schneiderian first rank symptoms and maintenance of emotional contact are important for diagnosis of volatile solvent psychosis.

Adolescent↗
PubMed1997

Severe metallosis caused by shaving down of the stem neck due to outer cup impingement of a bipolar endoprosthesis. A case report. off.

The authors report on a patient with severe metallosis caused by shaving down of the stem neck due to outer cup impingement. A primary arthroplasty was performed using an Omnifit bipolar endoprosthesis (Stryker) with an acetabular bone graft fixed by ceramic screws. At the time of revision surgery the synovium was stained black. Two ceramic screws were broken, but no scratch was observed on the metal surfaces of the outer cup and the inner head. The ultra-high molecular weight polyethylene (UHMWPE) of the inner-bearing collar was worn and flat. During the operation, a groove was observed at the stem neck where the outer cup impinges. An analysis of the black pseudocapsule by scanning electron microscopy with electron prove microanalysis (SEMEPMA) revealed that the pseudocapsule contained titanium metal particles. To our knowledge, metallosis caused by the same mechanism has only been reported in four joints, which were replaced by a Zimmer BHP bipolar endoprosthesis and Howmedica bicentric cup.

Female↗