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Biomedical subjects

Y Hirose

Publications and source records attributed to Y Hirose.

At least 73 records · Page 4Linked to original sources
PubMed2000

[Anesthetic management for placement of tracheobronchial stents in patients with airway stenosis].

We report the anesthetic management for stents placement in patients with tracheobronchial stenosis. The subjects were 6 patients with lung cancer and one patient with tracheal invasion of esophageal cancer. Anesthesia was induced with propofol, fentanyl and vecuronium, and maintained with propofol and vecuronium. After intubation, tracheostomy was performed. The patients were kept apnic during insertion of stents. Three patients had dynamic stents inserted from tracheostomy site and one orally. Three patients had Dumon stents inserted orally, but the procedure in one patient was cancelled because her stent could not be placed at appropriate position. We recommend the anesthetic management through the tracheostomy site for the placement of Dumon tubes or dynamic stents.

Adult↗
PubMed2000

Frequency of a 30-base pair deletion in the latent membrane protein-1 gene in Epstein-Barr virus-associated lymphomas in Japan.

The association of Epstein-Barr virus (EBV) with various lymphoid malignancies has been reported. The precise pathogenesis of EBV in malignancies has not yet been elucidated. Latent membrane protein-1 (LMP-1) and Epstein-Barr nuclear antigen-2 (EBNA-2) genes are suspected to be tumorigenic genes. Previous studies suggest that a deletion within the LMP-1 gene may increase the oncogenic potential of EBV. In this study, we analyzed the sequence within the carboxy terminal end of the LMP-1 gene in paraffin-embedded specimens from T-cell lymphomas, Hodgkin's disease (HD), and the buffy coat of peripheral blood from healthy individuals in Japan. Polymerase chain reaction (PCR) was performed using primers spanning the carboxy terminal region of the LMP-1 gene, and sequence analysis was performed to show the exact location of the deletion. The PCR product of the Raji cell line was 161 base pairs (bp), and the LMP-1 gene with deletion was 30 bp shorter in a direct sequence of PCR products. The 30-bp deletion was located in position 168285-168256 of the Raji cell. A deletion within the LMP-1 gene was found in 4 of 25 cases (16%) of EBV-positive T-cell lymphomas, 4 of 10 cases (40%) of EBV-positive HD cases, and 2 of 13 specimens (15%) with amplified PCR products from 49 healthy individuals. The incidence of the 30-bp deletion within the LMP-1 gene in HD was comparable to that of subjects in the United States and Brazil, but the deletion was not found in a high proportion of EBV-positive T-cell lymphoid malignancies. No statistical significance was found regarding the clinical outcome between patients with a deletion within the LMP-1 gene and patients with wild-type LMP. This deletion cannot be considered as simply causing the pathogenesis of EBV-associated lymphoid malignancies in Japan.

Adult↗
PubMed2000

[Problems in clinical use of intraarterial blood gas monitoring system, Paratrend 7].

We evaluated the intraarterial blood gas monitoring system Paratrend 7 in clinical use. One hundred and sixty six sensors used for patients receiving thoracic, open heart or great vessel surgery were tested for one year, prospectively. Sensors were inserted through a 20 G intraarterial cannula into the radial artery before operation and removed when they malfunctioned or seemed to be not necessary for patient management in critical care unit. We encountered several problems such as, initial calibration failure (5/166), impossible sensor insertion (2/166), arterial pressure wave change (5/166), parameter display failure (21/166), and thrombus in the circuit (9/166). Parameter display failure after insertion tended to occur on patient's arm movement imparing the sensor. No serious accident, such as arterial thrombosis was experienced. Some troubles were due to staff's incorrect handling of the apparatus. Training of staffs is indispensable for safe and sufficient utilization of Paratrend 7.

Aged↗
PubMed1999

Phosphorylated RNA polymerase II stimulates pre-mRNA splicing.

RNA polymerase II (RNAP II) is responsible for transcription of mRNA precursors in eukaryotic cells. Recent studies, however, have suggested that RNAP II also participates in subsequent RNA processing reactions through interactions between the carboxy-terminal domain (CTD) of the RNAP II largest subunit and processing factors. Using reconstituted in vitro splicing assays, we show that RNAP II functions directly in pre-mRNA splicing by influencing very early steps in assembly of the spliceosome. We demonstrate that the phosphorylation status of the CTD dramatically affects activity: Hyperphosphorylated RNAP IIO strongly activates splicing, whereas hypophosphorylated RNAP IIA can inhibit the reaction.

Cell Nucleus↗
PubMed1999

Physiologic and morphologic properties of motoneurons and spindle afferents innervating the temporal muscle in the cat.

Little is known about physiology and morphology of motoneurons and spindle afferents innervating the temporalis and on synaptic connections made between the two. The present study was aimed at investigating the above issues at the light microscopic level by using the intracellular recording and horseradish peroxidase or biotinamide labeling techniques and by the use of succinylcholine (SCh) for the classification of spindle afferents in the cat. Temporalis motoneurons had dendritic trees that ranged from a spherical form to an egg-shaped form. The shape deformation was more prominent for the dendritic trees made by motoneurons located closer to the nuclear border. No axon collaterals of the motoneurons were detected. On the basis of the values for the dynamic index after SCh infusion, temporalis spindle afferents were classified into two populations: presumptive groups Ia and II. The spindle afferents terminated mainly in the supratrigeminal nucleus (Vsup), region h, and the dorsolateral subdivision (Vmo.dl) of the trigeminal motor nucleus (Vmo). The proportion of group Ia afferent terminals was lower in the Vsup than that of group II afferents. In the Vmo.dl, the proportion of group Ia afferent terminals was nearly even throughout the nucleus, but that of group II afferent terminals increased in the more outlying regions. The proportion of terminal distribution in the central region of Vmo.dl was higher for group Ia than group II. The frequency of contacts (presumptive synapses) made by a single spindle afferent on a motoneuron was higher for group Ia than group II. The present study provided evidence that the central organization of spindle afferent neurons is different between groups Ia and II.

Animals↗
PubMed1999

Quantitative analysis of the dendritic architectures of cat hypoglossal motoneurons stained intracellularly with horseradish peroxidase.

Little is known about the dendritic architecture of cat hypoglossal motoneurons. Thus, the present study was done to provide quantitative descriptions of hypoglossal motoneurons and to determine correlations between dendritic size parameters by using the intracellular horseradish peroxidase (HRP) injection technique in the cat. Twelve hypoglossal motoneurons stained with HRP were antidromically activated by stimulation applied to the medial branch of hypoglossal nerve. Eight (type I) and four (type II) of the 12 motoneurons were located in the ventral and dorsal parts of the ventromedial subnucleus of hypoglossal nucleus, respectively. The somatodendritic morphology of the two types of neurons was remarkably different, especially in the dendritic arborization pattern. The type I neurons established an egg-shaped dendritic tree that was distributed through the nucleus to the reticular formation; the type II dendritic tree was confined within the nucleus and presented a rostrocaudally oriented, mirror-image, fan-shape appearance. The total dendritic area and length and the number of terminations and branch points were significantly larger for type I than for type II neurons. For the two types of neuron, there was a positive correlation between stem dendritic diameter and several dendritic size parameters. Although the slopes of the regression lines were slightly different between the two, these were not statistically significant. The present study provides evidence that hypoglossal motoneurons located in the ventromedial subnucleus could be divided into two types according to the dendritic arborization pattern and quantitative analysis of the dendritic tree and according to neuronal location and suggests that the two types of hypoglossal motoneurons can be viewed as intrinsically distinct cell types: type I and type II, which innervate extrinsic and intrinsic muscles, respectively. In addition, the morphometric analysis made it possible to estimate the size of the dendritic tree by measuring the stem dendritic diameter.

Animals↗
PubMed1999

Late hemorrhage from persistent pseudoaneurysm in vertebral artery dissection presenting with ischemia: case report.

BACKGROUND: Vertebral artery dissection lesions tend to resolve spontaneously, but abnormal findings such as aneurysmal-dilatation occasionally persist. However, the clinical features and pathological findings in such cases have never been verified. CASE DESCRIPTION: A 62-year-old man presented with left cerebellar infarction. Angiography showed the "pearl and string sign" in the left vertebral artery, and he was diagnosed as having left vertebral artery dissection. Repeated angiography showed persistent aneurysmal dilatation with irregular stenosis. Eleven years after the cerebellar infarction, the patient presented with a subarachnoid hemorrhage from an aneurysm of the left vertebral artery, and the lesion was explored via the left suboccipital approach. The vertebral artery was firm, making the placement of a clip impossible, so the lesion was treated by coating of the bleeding point. The patient died of pneumonia and hyperglycemia on postoperative day 15. Postmortem examination revealed an organized intramural hematoma, thickening of the intima, and fibrous degeneration of the media of the vertebral artery, a fusiform, distended thin arterial wall with intimal disruption at the aneurysmal dilatation, and arteriosclerosis of all cerebral arteries. CONCLUSION: This case indicates that persistent aneurysmal dilatation of a dissection is a pseudoaneurysm prone to rupture, and that healing of the affected vessels might be severely compromised in the presence of pathological conditions such as arteriosclerosis and disturbed intraluminal blood flow in the dissected lesions.

Aortic Dissection↗
PubMed1999

Microdetermination of the 6,15-diketo-13,14-dihydroprostaglandin F1alpha in human plasma using gas chromatography/selected ion monitoring with [18O]6,15-diketo-13,14-dihydro-prostaglandin F1alpha as an internal standard.

We devised a simple and effective purification method for the microdetermination of 6,15-diketo-13,14-dihydro-prostaglandin F1alpha (DK), a metabolite of prostacyclin (PGI2). [18O]DK was synthesized from the repeated base-catalyzed hydrolysis of methyl ester derivatives in [18O] water to obtain an internal standard for the gas chromatography/selected ion monitoring (GC/SIM) of DK. The methyl ester-methoxime-tert-butyldimethylsilyl ether derivative was prepared, then gas chromatography/selected ion monitoring was carried out by monitoring the ion at m/z 613.4 for DK and at m/z 617.4 for an internal standard. A good linear response over the range of 10 pg to 10 ng was demonstrated. We detected DK to a level of about 297.8 pg/ml in human plasma. This method can be used to determine DK in biological samples.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

Intraparenchymal and intrasylvian haematomas secondary to ruptured middle cerebral artery aneurysms: prognostic factors and therapeutic considerations.

The aim of this study was to investigate prognostic factors and the most appropriate treatment for patients with ruptured middle cerebral artery (MCA) aneurysms in relation to haematoma distribution. Ninety-two patients with ruptured MCA aneurysms, who underwent surgery during the last 11 years from 1986 to 1996, were assigned to one of the three groups according to the haematoma distribution. Group A comprised 17 patients who had an intraparenchymal haematoma (IPH) larger than 30 mm (maximum diameter) with or without subarachnoid haemorrhage (SAH), group B comprised 24 patients having a dense intra-Sylvian fissure haematoma (ISH) larger than 30 mm (maximum diameter) and group C consisted of 52 patients having only diffuse SAH without a localized dense haematoma. The clinical course and factors affecting the outcome of the patients in each group were investigated. Patients in groups A and B had a more severe clinical grade on admission than those in group C. As a result, patients in these two groups had a poorer outcome. In group C, independent life was achieved for 98% of the patients. In group A, the clinical grade on admission and the diameter of the haematoma were significantly correlated with outcome. Initial brain damage due to IPHs seemed to be the main cause of disability, while only 7% developed delayed ischaemic neurological deficits (DIND). In group B, 54% of patients suffered from subsequent brain oedema and DIND occurred in 50%. These factors were related to a poor outcome. The MCA aneurysms tend to have localized dense haematomas, as well as diffuse SAH; the former seems to affect more on the course and outcome of the patients. Accurate assessment of the bleeding patterns in patients with ruptured MCA aneurysms will be useful in helping us predict the clinical course and the most appropriate treatment for these individuals.

Adolescent↗
PubMed1999

A toxicokinetic analysis in a patient with acute glufosinate poisoning.

Incidents of poisoning in humans caused by the ingestion of the glufosinate ammonium containing herbicides are gradually increasing in Japan. This poisoning is characterized by various neurological symptoms such as disturbances of consciousness, convulsions and apnea which appear after an asymptomatic interval of several hours. We studied the toxicokinetics of glufosinate in a patient with this poisoning successfully treated without extracorporeal hemopurification. A 65-year-old male ingested BASTA, which contains 20% w/v of glufosinate ammonium, about 300 ml, more than the estimated human toxic dose. Four and a half hours after ingestion, he showed speech ataxia and systemic tremor. He was prophylactically intubated before the occurrence of serious respiratory failure. After 5 days of artificial ventilation he was extubated and discharged without any sequelae. We studied the serial change of serum glufosinate concentration every 3-6 h and assessed the urinary excretion of glufosinate every 24 h. The absorbed amount of glufosinate was estimated from the cumulative excreted in urine. Toxicokinetic analysis was performed using the two-compartment model. The changes in serum glufosinate concentration exhibited T1/2alpha of 1.84 and T1/2beta of 9.59 h. The apparent distribution volume at beta-phase and the total body clearance were 1.44 l/kg and 86.6 ml/min, respectively. Renal clearance was estimated to be 77.9 ml/min. The indication for extracorporeal hemopurification for this poisoning has been discussed.

Aged↗
PubMed1999

Probable lymphocytic hypophysitis diagnosed by short-term serial computed tomography and gallium-67 scintigraphy--case report.

A 61-year-old female presented with headache, malaise, and left oculomotor nerve paralysis. Computed tomography (CT) demonstrated a diffuse pituitary mass and enlarged pituitary stalk with homogeneous contrast enhancement. Her symptoms gradually resolved without treatment. Gallium-67 scintigraphy showed abnormal uptake in the pituitary lesion. Serial CT every 2 weeks after admission showed homogeneous contrast enhancement and shrinking of the pituitary mass to a normal size 12 weeks after the onset. The final diagnosis was lymphocytic adenohypophysitis without biopsy. Recurrence has not been observed for 8 years after discharge. The patient did not need hormone replacement therapy. Histological examination is not always necessary to diagnose probable lymphocytic adenohypophysitis with the characteristic feature of rapid onset, abnormal gallium-67 uptake in the lesion, and resolution of symptoms in the acute stage with shrinking of the lesion on neuroimaging.

Female↗
PubMed1999

[The efficiency of intermittent antegrade warm blood cardioplegia].

We studied the effects of modified Calafiore technique that is intermittent antegrade warm blood cardioplegia including potassium solution and oxygenated with normothermic cardiopulmonary bypass. From January 1996 to March 1997, 45 patients who had undergone elective coronary artery bypass grafting were assigned retrospectively to two groups. Warm group: 25 patients received intermittent antegrade warm blood cardioplegia with normothermic cardiopulmonary bypass. Cold group: 20 patients received intermittent antegrade cold blood cardioplegia with slight hypothermic cardiopulmonary bypass. Preoperative variables were similar in both groups. The rate of sinus rebeating after aorta declamping with DC was lower in warm group than in cold group [warm group 2/25 (8%) versus cold group 8/20 (40%); P < 0.05]. The levels of CK and CK-MB were significantly lower in warm group than in cold group on postoperative day 0. On postoperative day 0 and day 1, the dosage of cathecholamines were significantly less for the warm group than in the cold group. Perioperative events of IABP, PMI and neurological dysfunction were not statistically different. These results show that intermittent antegrade warm blood cardioplegia is a safe and effective method for myocardial protection. But it requires further assessment.

Aged↗
PubMed1999

[Application of continuous intra-arterial blood gas monitoring system "Paratrend 7" for pulmonary lavage of a patient with alveolar proteinosis].

We applied a continuous intra-arterial blood gas monitoring system (Paratrend 7) to a patient with pulmonary alveolar proteinosis during pulmonary lavage. Lavage was performed under general anesthesia with one lung ventilation. We inserted the sensor of Patatrend 7 through a 20 G catheter into the radial artery, and monitored pH, PaCO2 and PaO2 continuously throughout the procedure. SpO2 and EtCO2 were also monitored. Saline 1000-1500 ml was instilled and drained repeatedly by volume limited methods. PaO2 values by Paratrend 7 increased during instillation and decreased during drainage of the irrigating fluid. In contrast, PaCO2 value by Paratrend 7 decreased slightly during instillation and increased during drainage. The change of SpO2 was almost the same as that by Paratrend 7, but the response time of pulse oxymetry was a little quicker than Paratrend 7. During the lavage procedure, respiratory and circulatory condition changed very rapidly, and it is necessary to monitor blood gas change intensively. Paratrend 7 is useful as a perioperative monitoring system, but pulse oxymetry might be sufficient during pulmonary lavage considering its cost.

Adult↗
PubMed1999

Epstein-Barr virus study in malignant lymphoma in Sjögren's syndrome.

The association of Epstein-Barr virus (EBV) with Sjögren's syndrome (SS) is controversial. Reports suggest there is an increased risk of developing lymphoid malignancy in SS. Among our 425 cases of SS, 17 cases of malignant lymphoma (4%), 16 cases of non-Hodgkin's lymphoma (NHL), and 1 case of Hodgkin's disease were found. We looked for an association between EBV and 14 cases of NHL, 13 cases of B-cell lymphoma, and 1 case of T-cell lymphoma in which tissue specimens were available. Epstein-Barr virus-encoded RNA in situ hybridization study and polymerase chain reaction (PCR) study using primers to detect the Bam HI W fragment of EBV with DNA extracts were positive in 2 NHLs: 1 diffuse, large B-cell-type lymphoma, 1 out of 13 cases (8%) of B-cell lymphoma, and 1 angioimmunoblastic T-cell lymphoma with dysproteinemia. In the Bam HI W PCR study of DNA obtained from the labial small salivary glands of 55 cases with SS, 3 cases (5%) were positive. These 3 cases were not associated with malignant lymphoma. Our study revealed that EBV association in SS did not lead to an increased occurrence.

Aged↗
PubMed1999

[Metabolism of 3,3',4,4',5-penta- and 2,2',3,3',4,4'-hexachlorobiphenyls in rats].

Following the i.p. administration of 3,3',4,4',5-pentachlorobiphenyl (CB126) and 2,2',3,3',4,4'-hexachlorobiphenyl (CB128) to rats, blood, liver, lung, kidney, adipose tissue and feces were analyzed for the metabolites. CB126 was biotransformed to three hydroxylated metabolites identified as 4-OH-3,3',4',5'-tetraCB, 4-OH-3,3',4',5,5'-pentaCB and 5-OH-3,3',4,4',5'-pentaCB at about 1:7:2 ratio, whereas to two methylthio metabolites as 5-MeS- and 6-MeS-3,3',4,4',5'-pentaCBs at 1:2 ratio. Among the metabolites, only 4-OH-3,3',4',5,5'-pentaCB was detected in all tissues and blood. The ratio of metabolite/unchanged CB126 was 1:1.3 in blood and 1:162 in liver, indicating the high blood affinity of this metabolite. Trace amounts of 5-methylsulfonyl-3,3',4,4',5'-pentaCB was also detected in the liver. CB128 was biotransformed to 5-OH-, 5-MeS- and 6-MeS-2,2',3,3',4,4' hexaCBs which were excreted to feces in about 5:5:1 ratio. No metabolites were detected in blood and any tissues except for liver where trace amounts of 5-hydroxylated metabolite was present, indicating the low tissue affinity of hydroxylated metabolites from CB128.

Animals↗