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Biomedical subjects

K Kawakami

Publications and source records attributed to K Kawakami.

At least 181 records · Page 10Linked to original sources
PubMed1998

Modulation of LDL particle size after an oral glucose load is associated with insulin levels.

Individuals with a predominance of small low-density lipoprotein (LDL) particles appear to be at increased risk for coronary artery disease. The purpose of this study was to determine whether the LDL particle size was modulated in response to a 75-g oral glucose load. Overall, there were no significant changes in the LDL particle size after glucose load. However, the difference in LDL particle size (deltaLDL size) between the fasting and 2-h post-load states was inversely correlated with the fasting LDL particle size. Also, deltaLDL size was positively correlated with BMI and the post-load glucose levels. Forward stepwise regression analysis revealed three parameters as independent factors capable of modulating LDL particle size: BMI, fasting insulin, and post-load glucose levels. After adjustment for BMI and glucose levels, the levels of fasting and 2-h post-load insulin remain independent determinants of deltaLDL size. These results suggest that plasma insulin levels during glucose load modulate LDL particle size.

Adult↗
PubMed1998

Comparisons of chemically-induced mutation among four bacterial strains, Salmonella typhimurium TA102 and TA2638, and Escherichia coli WP2/pKM101 and WP2 uvrA/pKM101: collaborative study III and evaluation of the usefulness of these strains.

Over the past 5 years, a large collaborative study of chemically-induced mutation has been performed using the four bacterial strains Salmonella typhimurium TA102 and TA2638 and Escherichia coli WP2/pKM101 and WP2 uvrA/pKM101 in order to compare the specific spectrum of response to chemicals and to evaluate the usefulness (sensitivity) of each strain. Following the two collaborative studies to test the chemicals in category 1, chemicals previously judged as positive only in E. coli WP2 strains and derivatives of these chemicals, and category 2, oxidative agents or crosslinking agents, 22 compounds of category 3 consisting of 10 nonmutagenic carcinogens and another 12 chemicals were selected in this study. Twenty participating laboratories tested each compound in the same method as previous reports. In the group of nonmutagenic carcinogens, no chemical induced revertant colonies of any strain tested. In the group of other chemicals, response to the chemicals was similar in TA102 and WP2 uvrA/pKM101. Overall, in the three collaborative studies, a total of 79 compounds were tested. No difference in qualitative response to the four strains was observed for 71% (56/79) of the test chemicals. The combination of strains providing the greatest number of positive responses was WP2 uvrA/pKM101 with TA102; 84% (66/79) of the test chemicals elicited the same qualitative response in these two strains. Therefore, it is suggested that WP2 uvrA/pKM101 and TA102 can be included as a part of the standard tester strains for detection of mutagenic activity of chemicals.

Escherichia coli↗
PubMed1998

Effects of hyperosmolality on Na, K-ATPase gene expression in vascular smooth muscle cells.

Cultured vascular smooth muscle cells (VSMC) from rat thoracic aortas were exposed to hyperosmotic media to determine the effects on Na, K-ATPase alpha1- and beta1-mRNA expression. Hyperosmotic media (500 mOsm/kgH2O) supplemented with glucose or mannitol increased alpha1-mRNA levels threefold at 24 hr and beta1-mRNA levels sevenfold at 12 hr. In sharp contrast, hyperosmotic urea medium had no effect at any time. Both the protein synthesis inhibitor cycloheximide and the RNA transcription inhibitor actinomycin D reduced alpha1- and beta1-mRNA upregulation induced by hyperosmotic glucose or mannitol media. Protein kinase C (PKC) inhibitors (staurosporine A or calphostin C) or tyrosine kinase (TK) inhibitors (genistein or herbimycin A) had no effect on the alpha1-mRNA upregulation induced by hyperosmotic glucose or mannitol media. Hyperosmotic glucose or mannitol media (500 mOsm/kgH2O) significantly increased alpha1- and beta1-subunit protein levels and Na, K-ATPase activity, whereas hyperosmotic urea medium had no effect. Transfection experiments with the 5'-flanking sequences of the alpha1- or beta1-subunit genes linked to the luciferase reporter gene revealed that hyperosmolar glucose medium increased luciferase activity 2.9- and 3.7-fold, respectively. Similarly, hyperosmotic mannitol medium increased such activity 2.7- and 3.4-fold, respectively. These results demonstrate that: (i) hyperosmolality induced by the poorly permeating solutes (glucose and mannitol) stimulates alpha1- and beta1-mRNA accumulation, alpha1- and beta1-subunit protein accumulation, and Na, K-ATPase activity, whereas the rapidly permeating solute (urea) has no effect; (ii) the upregulation of alpha1- and beta1-mRNA in response to hyperosmotic glucose or mannitol media requires, at least in part, de novo synthesis of intermediate regulatory proteins; (iii) the hyperosmolality-induced alpha1-mRNA upregulation occurs through PKC- and TK-independent mechanisms, whereas the hyperosmolality-induced beta1-mRNA upregulation occurs through activation of PKC and TK; and (iv) hyperosmolality induced by glucose or mannitol increases promoter activities of the alpha1- and beta1-subunit genes.

Animals↗
PubMed1998

Granulocyte colony-stimulating factor and its receptor in acute promyelocytic leukemia.

Expression of granulocyte colony-stimulating factor (G-CSF) receptor (G-CSFR) and in vitro proliferative response to G-CSF were investigated by quantitative immunofluorescence and [3H] thymidine uptake, respectively, in a series of acute myeloid leukemias (AML). The results indicated that G-CSFR was detected at high levels in acute promyelocytic leukemia (APL) cells, in comparison with other types of AML. Moreover, APL cells were also seen to predominantly proliferate in response to G-CSF. Based on these observations, we administered recombinant human G-CSF to a patient with APL in the third relapse that was resistant to both cytotoxic agents and all trans retinoic acid, in an attempt to sensitize the leukemic cells to cell-cycle-dependent agents. Complete remission was achieved. The finding that APL cells are exquisitely responsive to G-CSF supports the view that G-CSF is useful for augmentation of their vulnerability to cell-cycle specific agents.

Adult↗
PubMed1998

Larynx-preserving resection of the cervical esophagus for cervical esophageal carcinoma limited to the submucosal layer.

This report describes the surgical procedure consisting of larynx-preserving resection of the cervical esophagus and satisfactory lymphadenectomy. The sternum was split at the level of the 3rd intercostal space, which allowed an upper-mediastinal lymphadenectomy to be performed easily. The cervical esophagus was reconstructed using a free jejunal autograft. The stump of the thoracic esophagus and the caudad stump of the jejunal graft were anastomosed using a circular stapling instrument. The posterior part of the cephalad esophagojejunostomy was completed in two layers using the Lembert stitch. The wall of the cervical esophagus was opened to determine the oral cut line considering the safety margin from the carcinoma. After cervical esophagectomy was completed, suturing of the anterior wall was performed in one layer. The left cervical transverse artery and the internal jugular vein were employed for recipient vessels. This procedure is acceptable for high cervical esophageal carcinoma limited to the submucosal layer.

Carcinoma, Squamous Cell↗
PubMed1998

Intramembrane structure of the sensory axon terminals in bullfrog muscle spindles.

Much physiologic and morphologic research has been done into the sensory mechanism of the frog muscle spindle. However, no freeze-fracture study has described in detail the shape and intramembrane structure of the nonmyelinated sensory axon terminals of the frog muscle spindle. In this study, muscle spindles were isolated from the red part of bullfrog semitendinous muscles. Chemically fixed spindles were subjected to freeze fracturing. The sensory axon endings were reconstructed, and the size and density of intramembrane particles (IMPs) were measured along the sensory nerve endings. The axon terminals had four distinctive parts: parent trunks (>0.5 microm in diameter), primary branches (0.15-0.5 microm), terminal branches (<0.1 pm), and varicosities (0.02-0.5 microm). IMPs ranged from 5 nm to 21 nm in diameter and were present in the intramembrane space of the plasma membrane all throughout the nonmyelinated sensory nerve endings. Mean IMP sizes in the protoplasmic face (PF) and the external face (EF), respectively, were 8.1 nm and 8.4 nm in the parent trunks, 8.8 nm and 8.8 nm in the primary branches, 9.4 nm and 9.0 nm in the varicosities, and 8.7 nm and 8.7 nm in the terminal branches. Mean IMP size in the PF was smallest in the parent trunk and largest in the varicosity. Mean IMP densities (numbers of IMPs per microm2) in the PF and the EF, respectively, were 2,500 and 700 in the parent trunks, 2,200 and 500 in the primary branches, 1,700 and 400 in the varicosities, and 1,000 and 300 in the terminal branches. Density decreased with the tapering of the axon terminal, with IMPs distributed evenly in the PF and the EF. The characteristic intramembrane structure of sensory nerve endings is discussed.

Animals↗
PubMed1998

Localization of Six4/AREC3 in the developing mouse retina; implications in mammalian retinal development.

The Six4/AREC3 gene was originally isolated as a regulatory factor which bound to the positive regulatory region of the Na, K-ATPase alpha 1 subunit. It is a murine homologue of the Drosophila sine oculis (so) gene, which is essential for the development of the entire insect visual system. In this study, we attempted to determine the localization of the Six4/AREC3 gene product in the developing mouse retina in order to examine its role in retinal cell differentiation. Immunohistochemistry with anti-SIX4/AREC3 and anti-Na, K-ATPase alpha 1 subunit antisera was performed on developing mouse retinas, and immunoblotting analysis with anti-SIX4/AREC3 was also performed. The localization of Six4-like immunoreactivity (Six4-LI) showed a temporally regulated pattern: During embryonic development, Six4-LI was found in the nuclei of cells located at the inner neuroblastic layer of the retina as early as on ED12, nearly corresponding to the onset of retinal cell differentiation. In the PD1 retina, Six4-LI was observed in the nuclei of the ganglion cells, and increased its intensity until PD4, and thereafter kept its intensity until PD7 when Six4-LI was often found in the cytoplasm. On PD4, the presumptive amacrine cells found in the inner portion of the inner nuclear layer appeared to be immunostained in their nuclei. On PD7, the presumptive bipolar cells located in the outer portion were immunostained in the nuclei. After that, Six4-LI gradually decreased, and in the mature retina no detectable Six4-LI was observed in the nuclei. This pattern of Six4-LI localization during retinal development seemed to correlate with retinal cell differentiation, but did not correlate with the distribution pattern of Na, K-ATPase alpha 1 subunit protein-like immunoreactivity. These results suggest that the Six4 gene may play a role in the differentiation of neural retinal cells during mouse retinal development, rather than regulating the expression of the Na, K-ATPase alpha 1 subunit gene.

Animals↗
PubMed1998

[Removal of infected pacemaker lead through sternotomy without cardiopulmonary bypass].

A 66-year-old man, who had undergone DDD pacemaker implantation for complete A-V block two years ago, was admitted because of endocarditis with septicemia and renal failure. His blood culture revealed Staphylococcus aureus. We tried to remove the infected cardiac pacemaker lead. But we failed to remove the atrial lead because it was strongly adhered with the right atrial appendage. Antibiotic therapy was ineffective. In the last resort, we operated through median sternotomy three months after the initial infectious episode. In intraoperative inspection, we found it difficult to remove the lead by traction because of atrial residual lead sticking out of the right atrial appendage. We applied a purse string suture on the right appendage and obtained successful removal of infected lead without the cardiopulmonary bypass. His postoperative course has been uneventful. He is totally asymptomatic and doing well up to now. In case of such local infection, we conclude that all transvenous leads should be removed and recommend a simultaneous implantation of the epicardial pacemaker system.

Aged↗
PubMed1998

[Massive mediastinal bleeding due to spontaneous rupture of the vertebral artery in von Recklinghausen disease].

In Von Recklinghausen disease, patients rarely demonstrate vascular abnormalities, but several reports have noted massive bleeding from vascular rupture. A 28-year-old man with Von Recklinghausen disease was admitted to our hospital because of swelling on the left neck accompanied by dyspnea. Neck and thoracic CT revealed a high density shadow on the mediastinum and left upper thorax which was suspected to indicate hemomediastinum. Under suspicion of bleeding from the intrathoracic artery, the patient underwent on surgery. Massive hematoma disrupted visual recognition of bleeding point, but under anatomical consideration, we concluded that the bleeding was from the ruptured left vertebral artery (VA) which branched independently from the aorta. The left VA was ligated distally and proximally. Left subclavian artery, injured unexpectedly, was not reconstructed but sutured carefully because of its fragility. Thus massive bleeding was controlled. Histology of the neighboring subclavian artery revealed involvement with neurofibrinomatosis. Although the patient's left arm demonstrated a slightly low blood pressure, he was discharged without complaint on the 56th postoperative day.

Adult↗
PubMed1998

Immunological competence and nutritional status in patients with lung cancer.

The rate of infection in patients with malignant disease is significantly higher than in patients with benign disease. To investigate whether immunological competence is impaired in patients with lung cancer, we assessed neutrophil function (chemotaxis, phagocytosis, bacterial killing activity, and superoxide production), monocyte function (phagocytosis and killing activity), lymphocyte subsets using flow cytometry, and proliferation of lymphocytes stimulated by phytohemagglutinin, concanavalin A, and pokeweed mitogen. Studies were performed on 22 untreated patients with lung cancer and 21 age-matched healthy volunteers. Nutritional status was assessed by Niederman's nutritional index. In patients with lung cancer neutrophil chemotaxis, monocyte phagocytosis and killing, proliferation of lymphocytes stimulated by phytohemagglutinin and concanavalin A, but not pokeweed mitogen, and the number of natural killer cells were significantly lower than in healthy volunteers, whereas gammadelta T cells were increased (p < 0.05). The mean score on Niederman's nutritional index was worse in patients than in healthy volunteers (p < 0.001). Our results suggest that the impaired immunological competence and undernutrition may be among the mechanisms causing increased susceptibility to infection in patients with lung cancer.

Adenocarcinoma↗
PubMed1998

Agenesis of the right lobe of the liver: report of a case.

A case of congenital agenesis of the right lobe of the liver detected in a patient with gastric cancer is reported. The diagnosis of this rare anatomical variant was established by a combination of computed tomography, abdominal angiography, and operative findings. The importance of accurately recognizing this condition is stressed, and the clinical presentation, radiographic appearance, and differential diagnosis are also discussed.

Aged↗
PubMed1998

Mass screening for neuroblastoma at 6 months of age: difficult to justify.

BACKGROUND/PURPOSE: A statistical analysis of the mass screening for neuroblastoma in Japan based on a population study rarely has been reported. This study aims to evaluate retrospectively the effectiveness of mass screening at 6 months of age using the available population data. METHODS: The data on the neuroblastoma cases registered by the Committee for Pediatric Solid Malignant Tumors in the Kyushu area were analyzed based on both screened and unscreened populations in the Kyushu area. RESULTS: From 1988 to 1992, the cumulative incidence of neuroblastoma in children less than 5 years of age was 82 in 484,599 for screened children, and 11 in 92,966 for unscreened children, respectively. Fourteen of the 82 screened patients had negative findings at 6 months of age (MS-negative cases). No significant difference was observed in the cumulative mortality rates from neuroblastoma in children younger than 5 years of age between the screened children and the unscreened children. Six of seven patients who died among the screened children were MS-negative cases with stage III or IV disease. In addition, no significant difference was found in the cumulative mortality rates from the neuroblastoma cases in patients less than 5 years of age between the children screened from 1988 to 1992 (7 of 484,599) and all children from 1980 to 1984 (14 of 668,084). CONCLUSIONS: These findings suggests that the majority of the patients detected by mass screening had a favorable prognosis, and, mass screening in Japan for children less than 6 months of age was not observed to reduce the incidence and mortality from neuroblastoma. Therefore, mass screening at 6 months of age was not found to improve substantially the prognosis of patients with unfavorable neuroblastoma identified over 1 year of age, which is the primary purpose of such mass screening for neuroblastoma.

Evaluation Studies as Topic↗
PubMed1998

A case of primary splenic large cell lymphoma with a t(9;14)(p13;q32).

t(9;14)(p13;q32), a subtype of 14q32 translocation, plays an essential role in the development of lymphoplasmacytoid lymphoma. t(9;14)(p13;q32) Causes juxtaposition of the PAX-5 gene on 9p13 and the IgH gene on 14q32, leading to the deregulation of the PAX-5 gene. We report a case of primary splenic lymphoma with a t(9;14). The histological diagnosis was diffuse large B-cell lymphoma without plasmacytoid differentiation. The lymphoma cells showed a complex karyotype including a t(9;14). Southern blot analysis localized the breakpoint of the PAX-5 gene within a couple of kb regions upstream of the exon 1A, although the involvement of the PAX-5 gene with the immunoglobulin heavy chain gene could not be confirmed.

Chromosomes, Human, Pair 14↗
PubMed1998

Medical baseline data collection on bone and muscle change with space flight.

It has been documented that astronauts suffer from a progressive and continuous negative calcium balance in space flight. The National Space Development Agency of Japan (NASDA) discussed the experimental protocols with the National Aeronautics and Space Agency's (NASA's) Johnson Space Center (JSC) and has started a medical baseline collection on bone and calcium metabolism, and muscle changes with space flight. The subjects were two astronauts, a 42-year-old female and a 32-year-old male, who experienced real space flights. Fractional excretion of calcium (FECa) increased in both subjects just after the space flight. There was a negative calcium balance with urinary calcium leak even after a short flight. We also noticed a decrease (-3.0%) of bone mineral density (BMD) of the lumbar spine (L2-4), a weight bearing bone. These bone changes may be due to a negative calcium balance. However, the BMD of the skull, a nonweight bearing bone, increased after the flight. This indicates that the effect of weightlessness on bone is different in respective bones, depending on the weight loading. Our data of the bone metabolic marker clearly indicate that bone resorption is stimulated, shown by an elevation of urinary pyridinolinks and plasma tartrate-resistant acid phosphate (TRACP) activity. Bone specific alkaline phosphatase, a bone formation marker, was elevated in both subjects, but not intact osteocalcin. Whether this pathophysiological phenomenon is due to an accelerated bone resorption or suppressed bone formation is still obscure. In addition, the physiological cross-sectional area (PCSA) of muscle in the legs greatly decreased (from - 10% to -15%) after the flight, and it took over a month to be recovered in both subjects. However, the muscle volume loss in the legs seemed to be reversible. To examine bone and muscle metabolism with space flight, further investigations and international standardization of experimental protocols are necessary.

Adult↗
PubMed1998

Characterization, chromosomal localization, and genetic variation of the alpha subunit of porcine eighth component of complement.

The complete amino acid sequence of the porcine alpha subunit of the eighth component of complement (C8A) was determined by characterizing the full length cDNA clone isolated from a porcine liver cDNA library. Porcine C8A was found to be similar to human and rabbit C8A in length, leader sequence, conserved cysteine residues, cysteine-rich modules, and overall sequence. Differences in the amino acid sequence among the three species were detected in the proposed candidate site for CD59 recognition (amino acids 352-389). The porcine C8A gene was physically mapped to chromosome 6q33-35 by in situ hybridization using the porcine bacterial artificial chromosome (BAC) clone as a hybridization probe. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of C8A was performed using the restriction enzyme Hha I. Distribution of the alleles was determined in pigs (n = 173) of several different breeds. Estimates of allele frequency of the 201 bp fragment were 0.22,.0.43,.0.04,.0.50,.0.58,.0.50,.0.98, and 0.91 in Landrace, Large White, Duroc, Berkshire, Jinhua, Crown Miniature Pig, wild boar, and Meishan, respectively.

Alleles↗
PubMed1998

Expression of the PAX5/BSAP transcription factor in haematological tumour cells and further molecular characterization of the t(9;14)(p13;q32) translocation in B-cell non-Hodgkin's lymphoma.

The PAX5 gene encodes the BSAP (B-cell-specific activator protein) which is a key regulator of B-cell development and differentiation. A recurring translocation t(9;14)(p13;q32) in non-Hodgkin's lymphoma moves the PAX5 on 9p13 within close proximity of the immunoglobulin heavy chain gene (IGH). KIS-1 cell line was established from a patient with diffuse large cell lymphoma of B-cell type carrying t(9;14). We analysed PAX5/BSAP expression by Northern and Western blotting in a panel of haematological tumour cell lines with other chromosome abnormalities in comparison with that of KIS-1. PAX5 mRNA and BSAP expression were detected in all B-cell lines tested, and the high level in KIS-1 was confirmed. However, a diffuse large B-cell lymphoma cell line and an acute B-lymphoid/myeloid leukaemia cell line expressed the PAX5/BSAP at levels comparable with KIS-1. PAX5 transcripts were readily detectable in clinical materials with a wide variety of B-cell neoplasms by reverse transcriptase-mediated polymerase chain reaction (PCR). Thus, PAX5/BSAP activation in haematological tumour cells is not necessarily associated with t(9;14). Although binding sites for BSAP have been identified in the promoters of CD19, this study failed to find clear correlation between the level of PAX5/BSAP expression and that of CD19. In contrast to KIS-1 in which the E mu enhancer of IGH was juxtaposed to PAX5, cloning of t(9; 14) from another case by long-distance PCR revealed that the PAX5 promoter was linked to a Cgamma constant region in divergent orientation, suggesting that the mechanism of PAX5 activation through recombination with IGH varies among individual cases. Breakpoints on 9p13 of the two translocations were clustered upstream of PAX5, leaving the PAX5 coding region intact.

Base Sequence↗
PubMed1998

Different susceptibilities of yeasts and conidia of Penicillium marneffei to nitric oxide (NO)-mediated fungicidal activity of murine macrophages.

Penicillium marneffei is an important opportunistic fungal pathogen. Host defence mechanisms against P. marneffei are not fully understood. We investigated the fungicidal activity of murine peritoneal macrophages against two forms of P. marneffei, conidia and yeast cells, and the involvement of the NO-mediated killing system. Peritoneal macrophages suppressed the intracellular growth of P. marneffei yeast cells and conidia. The number of live yeast cells within macrophages was significantly reduced by activation of macrophages by interferon-gamma (IFN-gamma), while a similar response was not observed with conidia. IFN-gamma-induced macrophage fungicidal activity against yeast cells was mediated by NO and was almost completely inhibited by N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of NO synthesis, while N(G)-monomethyl-D-arginine (D-NMMA), an optical isomer of L-NMMA, did not show any influence. NO production by macrophages stimulated with IFN-gamma was significantly enhanced when these macrophages were cultured with P. marneffei yeast cells, while conidia did not enhance macrophage NO production. Furthermore, yeast cells were more susceptible to the killing effect of chemically generated NO than conidia. Our results indicate that the yeast form of P. marneffei is more sensitive to the fungicidal activity of IFN-gamma-stimulated macrophages than conidia, and suggest that the different effects of two forms of P. marneffei on macrophage NO production and their different susceptibilities to NO may be reasons for the present findings.

Animals↗