Biomedical subjects

H Doi

Publications and source records attributed to H Doi.

At least 163 records · Page 9Linked to original sources

PubMed1995

Prediction of pulmonary function after resection of primary lung cancer. Utility of inhalation-perfusion SPECT imaging.

To help determine whether preoperative perfusion and inhalation SPECT imagings are useful in predicting postoperative lung function, Tc-99m MAA perfusion SPECT imaging, CT scans, and pulmonary function tests were prospectively performed in 33 patients with primary lung cancer before and after lobectomy or pneumonectomy. Tc-99m Technegas inhalation SPECT imaging was performed in 6 of 33 patients as well. The authors also studied changes in radioactivity on the operated and nonoperated sides before and after surgery, examined the lowest limit value for adaptability to the operation, and made a comparison of both perfusion and inhalation SPECT imaging. The predicted postoperative values obtained from the preoperative Tc-99m MAA SPECT images correlated more closely with the measured 6-month postoperative values than with the measured 3-month postoperative values. The highest correlation coefficient (r = 0.86) was observed between the predicted forced vital capacity (FVC) value and the measured 6-month postoperative FVC value. In many cases, there was not a great difference between the 6-month and 3-month radioactivity on the operated side obtained from Tc-99m MAA SPECT images. This appears to indicate that pulmonary blood flow on the operated side has completely recovered by 3 months after surgery. However, radioactivity in both the upper and lower lobes of the nonoperated side increased soon after surgery compared with that before the operation, and had not returned to preoperative levels 6 months after surgery. The radioactivity in the right middle lobe did not change before and after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

PubMed1995

Frequent detection of hepatitis C virus subtype 3a (HCV-3a) isolates in Thailand by PCR using subtype-specific primers.

By means of a polymerase chain reaction (PCR) method using subtype-specific primers for hepatitis C virus (HCV) subtypes 1a, 1b, 2a, 2b and 3a, the prevalence of each subtype among HCV isolates in Chiang Mai, Thailand, was determined. HCV-3a appeared to be the most common subtype in blood donors, and was also frequently found in patients with liver disease. HCV-1b, but not HCV-2a or -2b, was also commonly found in this area, while a considerable percentage of the total HCV isolates still remained unclassifiable by the above methods. Serotype analysis of the HCV isolates using C14-1 and C14-2 recombinant peptides revealed that HCV-3a was likely to carry an antigenic determinant(s) different from those of the major types 1 (HCV-1a and -1b) and 2 (HCV-2a and -2b).

Adult↗

PubMed1995

The hyperthermophilic archaeon Pyrodictium occultum has two alpha-like DNA polymerases.

We cloned two genes encoding DNA polymerases from the hyperthermophilic archaeon Pyrodictium occultum. The deduced primary structures of the two gene products have several amino acid sequences which are conserved in the alpha-like (family B) DNA polymerases. Both genes were expressed in Escherichia coli, and highly purified gene products, DNA polymerases I and II (pol I and pol II), were biochemically characterized. Both DNA polymerase activities were heat stable, but only pol II was sensitive to aphidicolin. Both pol I and pol II have associated 5'-->3' and 3'-->5' exonuclease activities. In addition, these DNA polymerases have higher affinity to single-primed single-stranded DNA than to activated DNA; even their primer extension abilities by themselves were very weak. A comparison of the complete amino acid sequences of pol I and pol II with two alpha-like DNA polymerases from yeast cells showed that both pol I and pol II were more similar to yeast DNA polymerase III (ypol III) than to yeast DNA polymerase II (ypol II), in particular in the regions from exo II to exo III and from motif A to motif C. However, comparisons region by region of each polymerase showed that pol I was similar to ypol II and pol II was similar to ypol III from motif C to the C terminus. In contrast, pol I and pol II were similar to ypol III and ypol II, respectively, in the region from exo III to motif A. These findings suggest that both enzymes from P. occultum play a role in the replication of the genomic DNA of this organism and, furthermore, that the study of DNA replication in this thermophilic archaeon may lead to an understanding of the prototypical mechanism of eukaryotic DNA replication.

Amino Acid Sequence↗

PubMed1995

Association between maternal antibodies to the external envelope glycoprotein and vertical transmission of human T-lymphotropic virus type I. Maternal anti-env antibodies correlate with protection in non-breast-fed children.

Vertical transmission of human T-lymphotropic virus type I (HTLV-I) depends primarily on breast-feeding; substitution of bottle-feeding has reduced the transmission rate from 20% in breast-fed children to 3% among bottle-fed. To determine the correlates of transmission for long breast-feeding (> or = 6 mo), short breast-feeding (< 6 mo), and bottle-feeding mothers, the antibody titers of transmitter (T) mothers and non-transmitter (nT) mothers were analyzed by using synthetic and recombinant epitopes representing the immunodominant epitopes of gag (Gag1a, r24), env (Env1/5, MTA1, RE3), and tax (Tax8/22-24) proteins. Seroreactivity to gag and tax epitopes was not significantly different except for anti-r24 antibody titer, which was significantly higher among T-mothers (geometric mean 134) when compared with nT-mothers (62) in the long-feeding group (P < 0.001). Profiles of antibody titers against env epitopes were different. Within the long-feeding group, Env1/5, MTA1, and RE3 titers were significantly higher among T-mothers (258, 1,476, and 738, respectively) when compared with nT-mothers (106, 279, and 320, respectively) (P < 0.01 for all three epitopes). In contrast, within the bottle-feeding group, antibody titers to Env1/5 (269) and RE3 (418) among nT-mothers were significantly higher than those among T-mothers (80 and 113, respectively) (P < 0.01). These data confirm that high-titered anti-HTLV-I antibodies in the long-feeding group correlate with milk-borne transmission of HTLV-I and, more importantly, imply that maternal anti-env antibodies may reduce the risk of non-milkborne infection.

Amino Acid Sequence↗

PubMed1995

Antithrombotic effect of TA-993, a novel 1,5-benzothiazepine derivative, in conscious rats.

Since reported experimental models of thrombosis are not suitable for comparison of several drugs by oral administration, we developed a convenient model for this purpose by applying direct current through an intravascular electrode. In conscious rats, which were implanted with anodal electrodes in the abdominal aorta on the day before the experiment, application of 200 microA of direct current induced the formation of a platelet-rich thrombus around the intravascular electrode. Using this model, we studied the antithrombotic effect of the novel antiplatelet agent TA-993, (-)-cis-3-acetoxy-5-(2-(dimethylamino)ethyl)-2,3-dihydro-8-methyl-2-(4- methylphenyl)-1,5-benzothiazepin-4(5H)-one maleate, and compared its effect with other antiplatelet agents. TA-993 at doses of 30 mg/kg, p.o. or more by single administration or at doses of 10 mg/kg or more by repeated administration dose-dependently suppressed the thrombus formation. Aspirin (10 mg/kg, p.o. or more), cilostazol (100 mg/kg, p.o.) and ticlopidine (30 mg/kg, p.o. or more) also suppressed the thrombus formation by single administration. These results suggest that TA-993 has a comparable antithrombotic effect with other antiplatelet agents, and thus it is a possible remedy for thrombotic and embolic diseases.

Administration, Oral↗

PubMed1995

Occult intrasacral meningocele with tethered cord--case report.

A 32-year-old female presented with a history of intermittent, severe lower back pain, exacerbated by pregnancy and persisting for several years. Magnetic resonance (MR) imaging showed a sacral mass as a low signal intensity area on the T1-weighted image and a high signal intensity area on the T2-weighted image, consistent with a cystic structure containing cerebrospinal fluid. A tethered cord attached to the thecal sac was also confirmed. Sacral laminectomy revealed thinned sacral vertebral laminae, but no neuronal elements existed within the cyst. The cyst was attached to the distal thecal sac by a small fistula. The thecal sac was explored, revealing a thick filum terminale, which was transected. The severe pain resolved postoperatively. This type of meningeal cyst, often called "occult intrasacral meningocele," is best diagnosed by MR imaging. Surgery to obliterate the fistulous tract is the optimum treatment. Total removal of the cyst is unnecessary, but evaluation of other associated congenial abnormalities is important.

Adult↗

PubMed1995

[The graft replacement of the patient with aortic arch aneurysm and thrombosed aortic dissection].

The patient was male and aged 68 years and complained of dyspnea and chest pain. He was pointed out aortic arch dilatation on chest X-ray and CT demonstrated aortic arch aneurysm accompanied with acute type IIIb aortic dissection. One month later after anti-hypertensive therapy, the false lumen of aortic dissection was closed with thrombus. While we performed the graft replacement to the aortic arch aneurysm, the thrombosed false lumen was recanalized, so it needed the closure of the false lumen reinforced with teflon felt. Postoperative angiography showed no abnormality of anastomosis and complete occlusion of the false lumen.

Aged↗

PubMed1995

[Posterolateral extradural approach for total excision of spinal meningeal cyst (type Ia): case report].

Lateral thoracic meningocele is an uncommon disorder known to occur with high frequency in patients with neurofibromatosis. We report a case not accompanied by neurofibromatosis and describe the operative technique utilizing a posterolateral extradural approach. A 41-year-old man was referred to our cardiologic clinic for severe anterior chest pain. Plain chest X-ray demonstrated an oval mass lesion in the right 9th to 10th thoracic paravertebral region. Magnetic resonance imaging revealed a cystic mass at the 10th thoracic intervetebral foramen without distortion of the spinal cord. Signal intensity of the cystic mass was the same as the cerebrospinal fluid around the spinal cord. In the prone position, laminotomy of the 10th vertebral only was carried out. A pulsatile round mass in continuity with the dura mater was exposed. The wall of the sac, which was thickened with CSF, was identified. The neck of the menigocele was ligated with the help of an aneurysm needle. The patient's severe chest pain disappeared postoperatively.

Adult↗

PubMed1995

[Aortic root replacement in twin Marfan patients].

We have performed aortic root replacement in twin Marfan patients. They were male and aged 33 years at the times of the operations. One had pneumonia but the other had no complaints. Echocardiography showed geometries typical of annuloaortic ectasia (aortic diameters of 6.4 and 6.8 cm) and a moderate degree of aortic insufficiency. Aortic roots were replaced utilizing composite valve graft and the coronary orifices were reimplanted with Carrel's patch technique. The operations were carried out at almost the same time. The patients had a satisfactory postoperative course. Because of the potential for late dissection or aneurysm in other areas of the aorta, they should have regular follow-up examinations by MRI and CT indefinitely.

Adult↗

PubMed1995

[Surgical treatment of mycotic coronary artery aneurysm associated with infective endocarditis: a case report].

53-year-old male was introduced our hospital for treatment of his infective endocarditis and congestive heart failure. Further evaluation revealed massive destruction of the mitral valve and aneurysm of the right coronary artery. We carried out an operation of aneurysmectomy and CABG with RGEA for coronary artery, and MVR using 29 mm SJM valve. Postoperative course was excellent. Graftgram showed good patency and perfusion of RGEA. Pathological findings were 1) macrophage infiltration into thrombi, 2) disappearance of elastic fibers of the media. 3) least atherosclerosis of the intima. We concluded that it was a mycotic coronary artery aneurysm. There have been no report of surgical treatment of such a mycotic coronary artery aneurysm upon our investigation.

Aneurysm, Infected↗

PubMed1994

Establishment and characterization of nurse cell-like clones from human skin. Nurse cell-like clones can stimulate autologous mixed lymphocyte reaction.

We have established nurse cell-like clones from long-term cultures of the human skin. These human skin nurse cell (HSNC)-like clones were type I collagen+, type IV collagen-, vimentin+, cytokeratin-, CD44+, CD54+, and weakly positive for VCAM-1, and easily identified by the pseudoemperipolesis that allowed T lymphocytes to migrate beneath the HSNCs. HSNCs and various T cell lines formed a typical complex in the hanging drop culture system. The majority of human and murine T cells, and some of the tumor cell lines other than T cells, including B lymphoma and myeloblastoma cells, migrated beneath the HSNC clones. HSNC clones produced various cytokines, including IL-6, IL-7, IL-8, IL-9, granulocyte CSF (G-CSF), granulocyte-macrophage CSF (GM-CSF), macrophage CSF (CSF-1), TGF-beta 1, and c-kit ligand, but could not produce IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, TNF-alpha, or TNF-beta. These characteristics were similar to those of nurse cells established from the murine thymus. Furthermore, IFN-gamma-pretreated HSNC clones that expressed MHC class II Ags induced autologous mixed lymphocyte reaction (AMLR) in autologous PBMCs to proliferate and exhibit the cytotoxicity against altered autologous cells and various tumor cells. These results suggest that HSNCs play an important role in the immunoregulation at skin tissues.

Animals↗

PubMed1994

Nucleotide sequence of the flgD gene of Salmonella typhimurium which is essential for flagellar hook formation.

We determined the complete nucleotide sequence of the flgD gene of Salmonella typhimurium which is essential for flagellar hook formation. The sequence predicts a protein of 232 amino acids and a calculated molecular mass of 23,987 Da. However, the N-terminal 86 amino acids of FlgD were found sufficient to complement all the flgD mutations examined. The predicted secondary structure suggested that FlgD has a high content of beta structure.

Amino Acid Sequence↗

PubMed1994

[Analysis of three-dimensional imaging of the right hepatic vein and right portal vein branch using 2D-TOF MR angiography: evaluation of utility of MR angiography in determining puncture course on TIPS].

2D-TOF MR angiographies were performed in seven patients of liver cirrhosis with hepatocellular carcinoma to investigate three-dimensional anatomical relationships of the right hepatic vein and first order of right portal vein branch. The puncture course was set up in three-dimensional rectangular coordinates, and the bend angle and turning angle of the modified Ross needle, and puncture distance were calculated of the data measured on the A-P and L-R projection images of MR angiograms. The utility and limitation of 2 D-TOF MR angiography to determine the puncture course on TIPS were discussed in this study.

Adult↗

PubMed1994

Stimulation of in vitro hematopoiesis by a murine fetal hepatocyte clone through cell-cell contact.

We have previously shown that a fetal liver-derived epithelial cell clone, FHC-4D2, could support hematopoiesis in vitro through its colony-stimulating factor (CSF) activities in a short-term culture. In this study, since FHC-4D2 cells were found capable of maintaining hematopoietic progenitors in the coculture for a long time, we examined how FHC-4D2 could exert hematopoietic supporting activity in a long-term culture by coculturing adult bone marrow (BM) cells or fetal liver (FL) cells on a monolayer of FHC-4D2 cells. This clone could maintain the colony-forming unit of granulocytes and macrophages (CFU-GM) of BM for > or = 12 weeks under the coculture condition, but the fibroblastic cell clone from the fetal liver, FHC-4A3, could not support the survival of CFU-GM, even for 1 week. In addition to BM CFU-GM, the FHC-4D2 clone also supported the survival of FL CFU-GM, burst-forming unit of erythroid cells (BFUe), and colony-forming unit of mixed progenitors (CFU-Mix) for longer than 4 weeks. When BM cells were separated by a membrane filter from the FHC-4D2 cells in the coculture, the comparable number of CFU-GM was maintained at day 3, but virtually no hematopoietic progenitors were detected at the end of the first week. CFU-GM were present in both nonadherent and adherent cells to the FHC-4D2 cells at day 3 of the coculture, but at day 7, the adherent population contained greater number of CFU-GM. CFU-GM derived from the adherent cells formed larger colonies and contained more bipotential CFU-GM than the nonadherent population. When BM cells from mice given 5-fluorouracil were cocultured with FHC-4D2 cells under the limiting dilution condition, interleukin-3 (IL-3)-responsive CFU-GM were induced from immature hematopoietic progenitor cells that were otherwise unresponsive to IL-3. From these data we conclude that the FHC-4D2 clone could generate and maintain IL-3-responsive hematopoietic progenitors via close contact and that, in the fetal liver, the contact between hepatocytes and hematopoietic cells may be critically important in inducing the differentiation of resting, IL-3-unresponsive immature hematopoietic cells into CFU-GM (progenitors responsive to IL-3) and in triggering the self-renewal of CFU-GM.

Animals↗

PubMed1994

The contribution of both forebrain and midbrain crest cells to the mesenchyme in the frontonasal mass of mouse embryos.

Migration of cranial neural crest cells is a crucial event in the formation of facial organs such as the frontonasal mass and branchial arches. However, the source of the populating crest cells that occupy the frontonasal mass remains unclear in mammalian embryos. To elucidate this, we performed focal DiI injections at various sites in the prosencephalon (forebrain, including the future telencephalon and diencephalon), mesencephalon (midbrain), and the anterior part of the rhombencephalon (hindbrain) separated posteriorly by the preotic sulus (i.e., rhombomere A; future rhombomere 1 and 2) of cultured mouse embryos from the 3- to 10-somite stage. Results directly revealed that during these stages the lateral edge of the prosencephalon produced crest cells which migrated to the frontonasal mass. On the other hand, labeled cells at the anterior neural ridge in the prosencephalon contributed mainly to the head epithelium, including the nasal placode, Rathke's pouch, and oral epithelium. As for the crest cells of the mesencephalon and rhombomere A, their destinations were significantly dependent on the injection site and somite stage. At the 3- to 4-somite stage, the crest cells emigrating from both the mesencephalon and rhombomere A migrated to the first branchial arch. Moreover, the mesencephalic region, but never rhombomere A, produced another group of crest cells that migrated to the frontonasal mass. In the 5- to 10-somite stage, the destinations of late-emigrating crest cells were restricted depending on their premigratory positions, i.e., the region producing crest cells migrating toward the frontonasal mass was restricted to the anterior portion of the mesencephalon, and the crest cells from the posterior portion of the mesencephalon primarily migrated to the first branchial arch, while those from the rhombomere A predominantly migrated to the trigeminal ganglion. Migration toward the frontonasal mass from the mesencephalon ceased at the earliest in the 7-somite stage, followed by termination of mesencephalic and rhombencephalic crest cell migration toward the first branchial arch at the 8-somite stage, whereas the contribution from rhombomere A to the trigeminal ganglion continued even at the 10-somite stage. This behavior suggests that both the prosencephalic and mesencephalic crest contribute to the mesenchymal cells in the frontonasal mass and also that the migration patterns of crest cells released from the prosencephalon, mesencephalon, and rhombencephalon depend on their axial level and developmental stage at initial emigration.

Animals↗

PubMed1994

Analysis of the core and E1 envelope region sequences of a novel variant of hepatitis C virus obtained in Indonesia.

Hepatitis C virus (HCV) is currently classified into 6 major types, HCV-1 through -6, each of which can be further divided into a few subtypes, e.g., HCV-1a, -1b, -1c, etc., on the basis of sequence variation of the viral genome. The core and E1 envelope regions of HCV genome were amplified from sera of Indonesian patients using reverse transcription-polymerase chain reaction. Sequence analysis of both core and E1 regions followed by molecular evolutionary phylogenetic analysis identified a novel sequence variant of HCV-1 (Td-6). Antibodies in the serum from which Td-6 was isolated reacted only marginally to the core protein of HCV-J, a representative strain of HCV-1b, despite strong antibody response against a mixture of the core, NS3 and NS4 proteins of HCV-1a. The possible mechanism for the diminished reactivity of the antibodies in the serum to the core protein of HCV-J is discussed.

Amino Acid Sequence↗

PubMed1994

Basic properties of super-elastic Ni-Ti alloy ligature wires for a new intermaxillary fixation method.

A new continuous wiring method of intermaxillary fixation with super-elastic Ni-Ti alloy ligature wires was developed to avoid the risk in postoperative emergency. Differential scanning calorimetry, three-point bending tests and fastening tests were carried out to investigate basic properties of the wires. Transformation temperatures of the Ni-Ti alloy wires were in the range suitable for exhibiting super-elasticity at body temperature. The Ni-Ti alloy wires possessed enough bending flexibility to be used in the continuous wiring method and showed great recoverable displacement in the fastening test. With use of these properties, easy removal in an emergency and uniform fixation can be attained.

Alloys↗

PubMed1994

Identification of hepatitis C virus subtype 3b (HCV-3b) among Japanese patients with liver diseases using highly efficient primers for reverse transcription-polymerase chain reaction.

With a reverse transcription-polymerase chain reaction method that utilized highly efficient primers, the NS5 region of hepatitis C virus (HCV) genome could be amplified from all of the 24 serum samples randomly obtained from Japanese patients with liver diseases. Subtype analysis on the basis of nucleotide sequence similarities of the amplified fragments revealed that 2 out of 24 Japanese patients (8.3%) were infected with the recently identified subtype HCV-3b, which had been thought to be rare in Japan.

Base Sequence↗