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Biomedical subjects

H Kida

Publications and source records attributed to H Kida.

At least 91 records · Page 5Linked to original sources
PubMed1998

Ipsilateral dominance of human olfactory activated centers estimated from event-related magnetic fields measured by 122-channel whole-head neuromagnetometer using odorant stimuli synchronized with respirations.

The aim of this study was to measure and analyze olfactory event-related magnetic fields using a whole-cortex biomagnetometer (122-channel SQUID gradiometer). Amyl-acetate gas (approx. 1%) was administered for 300 msec into either the right or left nostril in synchronization with respiration using a mask and an optical fiber sensor. Clear olfactory event-related magnetic fields were asymmetrically obtained on both sides of the forehead in all six subjects. The generators of olfactory magnetic fields were estimated at two regions located fairly asymmetrivally near the bilateral frontal deep areas. The goodness-of-fit was better for the two-dipole model than the one-dipole model in all experiments. In almost all subjects the latency and intensity of ipsilateral olfactory magnetoencephalography (MEG) responses were shorter and larger than those of the contralateral responses, respectively. These results suggest that the olfactory MEG responses on the ipsilateral side are generally larger and more dominant than those on the contralateral side in the human olfactory system.

Brain Mapping↗
PubMed1998

Promoter activity of sequence located upstream of the pseudorabies virus early protein 0 gene.

Promoter activity of the 5'-flanking region of the pseudorabies virus (PRV) early protein 0 (EP0) gene was analysed by transient transfection assays employing chloramphenicol acetyl transferase (CAT) reporter constructs. We identified a 213 bp segment of the viral genome that was capable of efficiently driving expression of the EPO gene and a linked reporter gene upon transient transfection into Vero cells. This segment lacked the typical TATA element, and possessed an initiator element and the putative binding sites for the transcription factor Sp1 and immediate-early protein IE180, a strong transactivator of PRV. By analysing 5'-deletion mutants of the segment, a 48 bp segment (from nucleotide positions -65 to -17), which possessed three Sp1 binding sites, was identified to be critical for the promoter activity. Cotransfection of Vero cells with the mutant constructs and an IE180 expression plasmid resulted in transactivation of only those constructs in which the Sp1 sites were present. These results indicate that the EP0 gene may be transcribed from the TATA-less promoter that responds to Sp1.

Animals↗
PubMed1998

Suppression of pseudorabies virus replication by a mutant form of immediate-early protein IE180 repressing the viral gene transcription.

A mutant form of the immediate-early (IE) protein IE180 of pseudorabies virus (PRV), dIN454-C1081 is a strong repressor of the PRV IE gene promoter. In order to assess the antiviral potential of the IE180 mutant, HeLa cells were transformed with the mutant gene and then infected with PRV and herpes simplex virus type 1 (HSV-1). The transformed cell lines showed marked resistance to PRV infection, but were susceptible to infection with HSV-1, indicating that the IE180 mutant expressed in the stable cell line specifically inhibited PRV growth. In those cells infected with PRV, transcription of the PRV IE gene was repressed. In addition, the IE180 mutant exhibited a dominant-negative property in transient expression assay. The present results indicate that the resistance of the cells to PRV infection was due to repression of the IE gene transcription by the IE 180 mutant.

Animals↗
PubMed1998

Spread of colorectal cancer micrometastases in regional lymph nodes by reverse transcriptase-polymerase chain reactions for carcinoembryonic antigen and cytokeratin 20.

BACKGROUND AND OBJECTIVES: Lymph node metastasis is known as a significant predictor of prognosis in colorectal cancer patients. Recently, reverse transcriptase polymerase chain reaction (RT-PCR) has been applied to detecting micrometastasis. To assess the risk of recurrence and accurately determine the spread of tumor cells, we examined lymph node micrometastases in a series of colorectal cancer patients. METHODS: We examined 202 lymph nodes obtained from 13 colorectal cancer patients who underwent curative operation and were histologically diagnosed to be node-negative, using RT-PCR to amplify mRNAs for two epithelial markers, carcinoembryonic antigen (CEA) and cytokeratin 20 (CK-20). RESULTS: All the cases, including early stage patients, had micrometastases. A total of 102 among 202 lymph nodes (50.5%) were positive for either CEA or CK-20, or both (47.0, 40.1, and 36.6% respectively). Positive lymph nodes were spread along the courses of vascular trunks as well as being located in more distant regions. CONCLUSIONS: Even in histologically negative lymph nodes, there is a considerable possibility that micrometastases may exist. Their detection by RT-PCR may improve clinical staging and indications for cancer therapy. We should also take care in the choice of surgical approach.

Adult↗
PubMed1998

An attenuation mechanism of Newcastle disease vaccine strain TCND.

To provide information on the mechanism of attenuation of a Newcastle disease vaccine strain, TCND, we compared it with the parental virulent strain California 11,914 (CAL) biologically and genetically. It was found that TCND bore the fusion protein of virulent type, consisting of a pair of dibasic amino acid residues at the cleavage site and was a temperature sensitive (ts) mutant restricted to grow at 41.5 degrees C. Revertants were obtained by prolonged incubation of chicken embryos inoculated with TCND at the nonpermissive temperature. In cultured cells, viral gene transcription and protein synthesis of TCND occurred similarly to those of CAL and the revertants at 41.5 degrees C. Hemadsorption and immunofluorescence assays revealed that cell surface expression of functional hemagglutinin-neuraminidase (HN) of TCND at 41.5 degrees C was lower than that at 35 degrees C. The revertants exhibited lower activity in fusion assay than CAL and recovered virulence to chicken only in part. The results indicate that the ts mutation of TCND in association with the defect of HN glycoprotein transport is a mechanism of the attenuation, and in addition, some other factors such as fusion activity should be involved in the loss of virulence of CAL to chickens.

Amino Acid Sequence↗
PubMed1998

Continued circulation of reassortant H1N2 influenza viruses in pigs in Japan.

In 1991 and 1992, H1N2 influenza A viruses were isolated from the lungs of pigs with overt signs of respiratory disease at farms in the Chiba and Kanagawa prefectures of Japan. To determine the genetic origin of these isolates, we phylogenetically analyzed partial nucleotide sequences of their genes. The results indicate that influenza viruses possessing the N2 of human influenza virus and seven other gene segments of classical H1N1 swine influenza virus, which were first isolated in 1980, have become established in Japanese pigs.

Animals↗
PubMed1998

Fusion of influenza virus with the endosomal membrane is inhibited by monoclonal antibodies to defined epitopes on the hemagglutinin.

Epitopes on the hemagglutinin (HA) of A/seal/Massachusetts/1/80 (H7N7) influenza virus were mapped by genetic analysis of variants selected with monoclonal antibodies (MAbs). Electron microscopic studies demonstrated that the sites and the directions to which hemagglutination-inhibiting (HI) MAbs and non-HI MAbs bound were different on the HA molecule. Morphological analysis revealed that HI MAbs blocked attachment of the virus to the cells, while non-HI MAbs did not. Virus particles bound with non-HI MAbs were then found in the intracellular vacuoles. Together with the electron microscopic findings, a fluorescence dequenching assay indicated that non-HI MAbs inhibited the fusion of virus with the intracellular vacuolar membrane. It was thus shown that non-HI neutralizing MAbs did not inhibit attachment of the virus to the host cell receptor, but inhibited the fusion step in intracellular vacuoles. The results support the hypothesis that anti-HA MAbs which lack HI activity neutralize viral infectivity by interfering with the low pH-induced conformational change in the HA molecule, resulting in inhibition of the fusion step in the viral replication process (Kida, H., Yoden, S., Kuwabara, M., Yanagawa, R., 1985. Interference with a conformational change in the HA molecule of influenza virus by antibodies as a possible neutralization mechanism. Vaccine 3, 219-222).

Animals↗
PubMed1998

Pseudorabies virus (PRV) early protein 0 activates PRV gene transcription in combination with the immediate-early protein IE180 and enhances the infectivity of PRV genomic DNA.

Pseudorabies virus (PRV) early protein 0 (EP0) functions as a transactivator of the viral gene promoters. In transient expression assays employing chloramphenicol acetyl transferase (CAT) reporter constructs, EP0 and the immediate-early protein IE180 act in an additive manner to activate transcription from the thymidine kinase (TK) and glycoprotein G (gG) gene promoters. EP0 enhanced the synthesis of infectious virus in cotransfection experiments with the EP0-expression plasmid and PRV genomic DNA. EP0 was detected by Western blot analysis in the purified virions. These results may indicate that EP0 in the virions acts as an important transactivator to express the immediate-early gene efficiently in the first stage of infection, and IE180 and EP0 expressed after the infection cooperatively activate the early and late gene expression in the later stage of infection.

Animals↗
PubMed1998

Somatic alterations of the SMAD-2 gene in human colorectal cancers.

The SMAD-2 gene, which is located at 18q21, has been identified as a candidate tumour-suppressor gene from work on colorectal cancers. The aim of the present study was to determine the clinical alterations and the significance of its mutations in a series of colorectal cancers previously examined for SMAD-4/DPC-4 gene. Mutation analyses of the SMAD-2 gene were carried out on cDNA samples from 36 primary colorectal cancer specimens using a combination of the polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP) and DNA sequencing. Only one missense mutation (2.8%), producing an amino acid substitution in the highly conserved region, and two homozygous deletions (5.5%) of the total coding region of the SMAD-2 gene were detected in the 36 cancers. The SMAD-2 gene may play a role as a candidate tumour-suppressor gene in a small fraction of colorectal cancers. However, allelic loss at 18q21 is very often seen in this type of tumour. Even in combination with changes in SMAD-4, the observed frequency was not sufficient to account for all 18q21 deletions in colorectal cancers. Thus, another tumour-suppressor gene, such as DCC, discovered as the first tumour-suppressor candidate in the region may also exist in this chromosome region.

Aged↗
PubMed1998

Intestinal bacterial hydrolysis is required for the appearance of compound K in rat plasma after oral administration of ginsenoside Rb1 from Panax ginseng.

Ginsenoside Rb1 from Panax ginseng root is transformed into compound K via ginsenosides Rd and F2 by intestinal bacterial flora. Among 31 defined intestinal strains from man, only Eubacterium sp. A-44 transformed ginsenoside Rb1 into compound K via ginsenoside Rd. The ginsenoside Rb1-hydrolysing enzyme isolated from Eubacterium sp. A-44 was identical to a previously purified geniposide-hydrolysing beta-D-glucosidase. When ginsenoside Rb1 (200 mg kg-1) was administered orally to germ-free rats, neither compound K nor any other metabolite was detected in the plasma, intestinal tract or cumulative faeces 7 or 15 h after administration. Most of the ginsenoside Rb1 administered was recovered from the intestinal tract, especially the caeca, and cumulative faeces indicating poor absorption of ginsenoside Rb1. When ginsenoside Rb1 was administered orally to gnotobiote rats mono-associated with Eubacterium sp. A-44, a significant amount of compound K was detected in the plasma and considerable amounts were found in the caecal contents and cumulative faeces 7 and 15 h after administration. A small amount of ginsenoside Rb1 was detected in the caecal contents only 7 h after administration. These results indicate that orally administered ginsenoside Rb1 is poorly absorbed from the gut but that its metabolite compound K, produced by ginsenoside Rb1-hydrolysing bacteria such as Eubacterium sp. A-44 in the lower part of intestine, is absorbed.

Administration, Oral↗
PubMed1998

Molecular basis for the generation in pigs of influenza A viruses with pandemic potential.

Genetic and biologic observations suggest that pigs may serve as "mixing vessels" for the generation of human-avian influenza A virus reassortants, similar to those responsible for the 1957 and 1968 pandemics. Here we demonstrate a structural basis for this hypothesis. Cell surface receptors for both human and avian influenza viruses were identified in the pig trachea, providing a milieu conducive to viral replication and genetic reassortment. Surprisingly, with continued replication, some avian-like swine viruses acquired the ability to recognize human virus receptors, raising the possibility of their direct transmission to human populations. These findings help to explain the emergence of pandemic influenza viruses and support the need for continued surveillance of swine for viruses carrying avian virus genes.

Adaptation, Biological↗
PubMed1998

Metabolism and pharmacokinetics of orally administered saikosaponin b1 in conventional, germ-free and Eubacterium sp. A-44-infected gnotobiote rats.

The metabolic fate of saikosaponin b1 (1) was investigated using conventional, germ-free and Eubacterium sp. A-44-infected gnotobiote rats. After the oral administration of 1 to germ-free rats at a dose of 50 mg/kg, no metabolite was detected in the plasma, the cecal contents or the cumulative feces through the experiment. On the other hand, when 1 was orally given to the Eubacterium sp. A-44-infected gnotobiote rats, considerable amounts of its metabolites, prosaikogenin A (2) and saikogenin A (3), were detected in the rat plasma with the respective AUC0-10 h values of 17,424 and 22,260 pmol.min/ml, similar to the case of its oral administration to conventional rats (AUC0-10 h values of 9,936 and 12,414 pmol.min/ml for 2 and 3, respectively). Furthermore, significant amounts of both metabolites were detected in the cecal contents and the cumulative feces of the gnotobiote and conventional rats, but not in those of the germ-free rats, within 10 h after the administration. Fecal and cecal activities of hydrolyzing 1 and 2 were found in the gnotobiote and conventional rats, though there were no detectable activities in the germ-free rats. Accordingly, both hydrolyzing activities in the intestinal bacteria, such as Eubacterium sp. A-44, are essential for the appearance of 2 and 3 in the rat plasma and cumulative feces, since orally administered 1 was poorly absorbed from the gastrointestinal tract.

Animals↗
PubMed1998

Methylprednisolone pulse therapy in two clinical types of crescentic glomerulonephritis.

To clarify the effectiveness of methylprednisolone pulse therapy on crescentic glomerulonephritis (CresGN), data of 46 patients was retrospectively studied. According to the slope of reciprocals of serum creatinine (s-Cr) the patients were divided into acute and insidious types, and each type was further divided into pulse (P) and conventional (C) therapy groups. In group C, s-Cr improved more frequently in the acute type (8/10) than in the insidious type (1/9, p<0.05), and the renal survival rate was somewhat higher in the former (p=0.09). In the acute type there was no difference in the improvement rate of s-Cr between the two therapy groups, whereas in the insidious type, the improvement rate was higher in group P (9/15) than in group C (1/9, p<0.05) and the renal survival rate was higher in the former (p<0.01). These results suggest that methylprednisolone pulse therapy may be highly effective for the insidious type of CresGN.

Acute Disease↗
PubMed1998

Potentially virulent Newcastle disease viruses are maintained in migratory waterfowl populations.

Forty-seven Newcastle disease virus (NDV) strains isolated from fecal samples of waterfowls in Alaska and Siberia from 1991 to 1996 were analyzed for their virulence. None of the viruses formed plaques on MDBK cells in the absence of trypsin. Of these, 29 strains showed virulent character by the mean death time with the minimum lethal dose in chicken embryos comparable to velogenic NDV strains. Of the 29 strains, 11 were sequenced for their fusion protein (F) gene. The results showed that 5 of them contained a pair of dibasic amino acids at the cleavage site of the F, which is of a virulent type. The present results suggest that potentially virulent strains of NDV are maintained in migratory waterfowl populations in nature, and that some of those may be transmitted to domestic poultry and acquire pathogenicity during passages in chicken population.

Alaska↗
PubMed1998

[Effect of the continuous epidural buprenorphine injection in patients after lower extremity arthroplasty].

We studied the analgesic effects of continuous epidural injection of buprenorphine in patients after lower extremity arthroplasty. In these patients anesthesia was maintained only with lumbar epidural anesthesia with 2% mepivacaine. We employed a balloon type continuous infuser (DIB Catheter, 40 ml.day-1) for postoperative analgesia for twenty-four hours. The patients were classified into three groups according to the method of buprenorphine injection and the content of DIB Catheter. First group (group A ; N = 37) received buprenorphine (0.2 mg) with 0.25% bupivacaine (40 ml) for twenty-four hours. Next group (group B ; N = 27) received bolus injection of buprenorphine (0.2 mg) for the first additional epidural injection of local anesthetic and received continuous injection of buprenorphine (0.2 mg) with 0.25% bupivacaine (40 ml) for twenty-four hours. The last group (Group C ; N = 40) also received bolus injection of buprenorphine as in group B, but received continuous buprenorphine infusion with normal saline instead of local anesthetics. The analgesic effect was determined by the postoperative usage of other analgesics (NSAID or pentazocine) by request of patients. In twenty-four hours, the numbers of patients who did not request other analgesics were 6 (Group A. 16%), 9 (Group B. 33%) and 19 (Group C. 48%), respectively. In Group A, 18 patients requested analgesics, but only 8 patients requested in Group C. It was effective for the postoperative analgesia to use the continuous epidural injection with DIB Catheter for patients after lower extremity arthroplasty. It was necessary to give a bolus injection of buprenorphine before the end of surgery for sufficient analgesia, but it was not necessary to add local anesthetics in the content of DIB Catheter.

Adult↗
PubMed1998

[Polymyositis-induced respiratory failure in the presence of antecedent pleural effusion].

Pulmonary involvement is generally recognized to be an important determinant of the clinical course in cases of polymyositis. A patient with bilateral pleural effusion as an initial symptom developed respiratory failure due to muscle weakness. Polymyositis was diagnosed on the basis of a muscle biopsy. A chemotherapy regimen consisting of methyl prednisolone (1 g/day for 3 days) followed by prednisolone (60 mg/day) alleviated, the pleural effusion and respiratory failure. Though pleural complications in polymyositis have been described mostly in association with concomitant interstitial lung disease, our patient exhibited only bilateral pleural effusion. Given that pleural effusion can be an initial symptom of polymyositis, it seems necessary that polymyositis be taken into consideration by differential diagnoses of pleural effusion of unknown etiology.

Aged↗
PubMed1998

[Severe pneumococcal pneumonia with acute respiratory failure and neutropenia].

Severe pneumococcal pneumonia may precipitate both respiratory failure and neutropenia. The prognoses are considered to be very poor in such cases. We encountered three patients with pneumococcal pneumonia presenting respiratory failure and neutropenia, and successfully treated two. All three patients showed disseminated intravascular coagulation, and respiratory failure requiring mechanical ventilation. Neutropenia was treated with granulyte-colony stimulating factor (G-CSF), with methylpredonisolone administered by pulse therapy for 3 days to treat severe respiratory failure during the clinical course. All 3 patients were relieved of their respiratory failure at least for a few days following treatment. As a result of treatment with antibiotics and G-CSF, pneumococci disappeared from the patients' sputum. However, it has been reported that disintegration of the bacterial cell walls can release inflammatory components capable of causing secondary inflammatory reactions in the lung tissue. This suggested that the worsening respiratory failure experienced by our patients during their clinical course was a result of such reactions, and that methylpredonisolone was effective as the treatment of inflammation.

Aged↗