Biomedical subjects

T Konno

Publications and source records attributed to T Konno.

At least 73 records · Page 4Linked to original sources

PubMed1998

Neonatal intrahepatic cholestasis with hepatic siderosis and steatosis.

Neonatal intrahepatic cholestasis is a heterogeneous disease of undetermined cause. There is an unreported subset of idiopathic neonatal intrahepatic cholestasis with an unusual histological combination of hepatic siderosis and macrovesicular steatosis. The patients were a 34-day-old female and a 39-day-old male with normal birth weights. Their mothers had received oral iron supplement 4-6 weeks before delivery. The patients had obstructive jaundice noticed at the well-baby clinic at 1 month of life. They had high levels of serum galactose and tyrosine, hyperferritinemia. Urinary organic acid and bile acid analyses were negative, and galactose-1-phosphate uridyltransferase activity in red cells was normal. Liver biopsies showed diffuse iron deposits and macrovesicular fat. By substituting formula milk with lactose-free milk, the patients responded, and had normal biochemical tests within 5 months of life. Follow-up biopsies, at the age of 12 months, showed mild residual fibrosis without iron or fat deposits. They are both well at 3 and 6 years of age, respectively, without biochemical liver dysfunction and neurologic impairment. Prenatal iron-overload might contribute to the pathogenesis of the disease, but further studies are needed to confirm the assumption.

Cholestasis, Intrahepatic↗

PubMed1998

Detection of the PGP9.5 and tyrosine hydroxylase mRNAs for minimal residual neuroblastoma cells in bone marrow and peripheral blood.

The "touchdown" polymerase chain reaction (PCR) technique has been applied to analyze expression of the neuron-specific protein, PGP9.5, and tyrosine hydroxylase (TH) genes for detection of minimal residual neuroblastoma cells in bone marrow and peripheral blood. PGP9.5 and TH gene products were not detected in any normal samples (n = 72) examined. However, in patients more than 1 year of age with stage III and IV neuroblastoma PGP9.5 mRNA was detected in six of seven bone marrow samples and in four of eight peripheral blood samples, and TH mRNA in four of seven and three of eight, respectively. The detection sensitivity was up to 10(-6) to 10(-7) micrograms of total cellular RNA for PGP9.5 and 10(-4) micrograms for TH. Among forty bone marrow specimens from nineteen patients with neuroblastoma both PGP9.5 and TH mRNAs were detected in six, and only PGP9.5 mRNA was detected in ten. Since detection of PGP9.5 and TH gene transcripts by the "touchdown" PCR was highly specific and sensitive, it might be most informative at present to carry out both PGP9.5 and TH mRNA assays for minimal residual neuroblastoma cells in blood and bone marrow.

Bone Marrow↗

PubMed1998

A novel dosage approach for evaluation of SMANCS [poly-(styrene-co-maleyl-half-n-butylate) - neocarzinostatin] in the treatment of primary hepatocellular carcinoma.

We report a Phase I/II clinical trial of poly-(styrene-co-maleyl-half-n-butylate)-neocarzinostatin (SMANCS) for intra-arterial treatment of hepatoma. Early patients received 4 or 8 mg SMANCS dissolved in Lipiodol; later patients were treated according to tumour size and degree of filling achieved. SMANCS/Lipiodol drained rapidly from normal liver but was retained within tumour interstitium. Tumour nodules filled with SMANCS/Lipiodol usually stabilised and often regressed. No UICC criteria-defined responses were achieved, partly due to difficulties of filling several lesions simultaneously. Signs of therapeutic activity suggest a more extensive clinical study is warranted.

Abdominal Pain↗

PubMed1998

[Targeted chemotherapy of hepatocellular carcinoma with SMANCS/Lipiodol--how to use SMANCS/Lipiodol].

The first drug only for arterial injection, SMANCS/Lipiodol, which offers targeted chemotherapy for hepatocellular carcinoma (HCC), now commercially available. Based on our experience using SMANCS/Lipiodol for 424 patients with HCC, the golden standard of how to use SMANCS/Lipiodol for complete necrosis of tumor was described. The initial dose of SMANCS/Lipiodol was varied 2 to 6 mg per body, mainly depending on the size of the tumor. All feeding arteries of HCC have to be verified on angiogram, and the drug must be injected via an adequate artery. Sometimes, a tumor changes its feeding arteries. Additional administrations with an interval of one month were done till the entire tumor was filled with SMANCS/Lipiodol (grade 4). One or two months after achievement of grade 4, we must examine how much drug was removed from tumor on CT. If the entire tumor is not filled with the drug, further injections are recommended to maintain grade 4. Almost all tumors shrank in 3 to 4 months while maintaining grade 4. Frequent administration of low doses (1-3 mg per body) is recommended. Discontinvation of administration was done on the following findings; tumor size reduction of over 90% or complete disappearance of tumor stain. With arterial injection therapy of SMANCS/Lipiodol, survival of patients with unresectable HCC was prolonged, especially in 272 patients who were good candidates for therapy. (Those with Child C liver cirrhosis, with a tumor occupying all four segments of the liver, and/or with extrahepatic spread at initial arterial injection of the drug were excluded.) The 1, 2, 5, and 10 year survival rates were 83%, 58%, 34%, and 25%, respectively.

Antineoplastic Agents↗

PubMed1998

Progression to moderate or severe mitral regurgitation after percutaneous transvenous mitral commissurotomy using stepwise inflation technique.

Progression to moderate or severe mitral regurgitation (MR) was studied after Inoue balloon percutaneous transvenous mitral commissurotomy (PTMC) using the stepwise inflation technique, performed at increments of 1 mm of balloon diameter, in 49 consecutive patients with rheumatic mitral stenosis (aged from 32-73 years; 8 males, 41 females). The patients were classified on the basis of the degree of MR after PTMC, compared with that before PTMC, into either Group A, development of moderate or more severe (> or = grade 2) MR (n = 8) or Group B, no increase in MR or development of mild (grade 1) MR (n = 41). Progression to moderate or severe MR was significantly associated only with advanced age (60 +/- 8 vs 52 +/- 10 years, p < 0.05) and narrower mitral valve area (0.87 +/- 0.35 vs 1.11 +/- 0.29 cm2, p < 0.05), but other characteristics before PTMC were similar in both groups. There was no difference between the two groups in the total number and degree of balloon inflation. Immediately before the final inflation, the left atrial mean pressure and v wave pressure were decreased in smaller degrees in Group A compared with Group B (-2 +/- 2 vs -5 +/- 4 mmHg, p < 0.05; -2 +/- 2 vs -6 +/- 6 mmHg, p < 0.05, respectively). Thus, the stepwise inflations require careful monitoring of changes in the left atrial pressure and waveform to recognize the aggravation of MR, especially in older patients with severe stenosis. Patients who do not have a significant drop in left atrial mean pressure and v wave pressure during stepwise inflations of the balloon might be at risk of development of moderate or severe MR after further dilations.

Adult↗

PubMed1997

Structural and functional roles of modules in hemoglobin. Substitution of module M4 in hemoglobin subunits.

The alpha- and beta-subunits of human hemoglobin consist of the modules M1, M2 + M3, and M4, which correspond to the exons 1, 2, and 3, respectively (Go, M. (1981) Nature 291, 90-92). To gain further insight into functional and structural significance of the modules, we designed two kinds of chimeric hemoglobin subunits (chimeric alphaalphabeta- and betabetaalpha-subunits), in which the module M4 was replaced by the partner subunits. CD spectra in the far-UV region showed that the secondary structure of the chimeric alphaalphabeta-subunit drastically collapsed, while the chimeric betabetaalpha-subunit conserved the native globin structure (Wakasugi, K., Ishimori, K., Imai, K., Wada, Y., and Morishima, I. (1994) J. Biol. Chem. 269, 18750-18756). SAXS data also suggested a partially disordered structure of the chimeric alphaalphabeta-subunit. Based on tryptophan fluorescence spectra and computer modeling from x-ray structures of native globins, steric constraint between Trp14 and Tyr125 would be induced in the chimeric alphaalphabeta-subunit, which would perturb the packing of the A- and H-helices and destabilize the globule structure. On the other hand, such a steric constraint was not found for the counterpart chimeric subunit, the betabetaalpha-subunit. The different stabilities of these module-substituted globins imply that modules would not always be stable "structural" units, and interactions between modules are crucial to construct stable globin subunits.

Circular Dichroism↗

PubMed1997

A circular dichroism study of preferential hydration and alcohol effects on a denatured protein, pig calpastatin domain I.

Pig calpastatin domain I (CSD1), a proteinase inhibitor that specifically blocks activity of calpain I and II, is a good candidate protein for studying conformational variations in the denatured form of protein. An extensive structural characterization of CSD1 reported in the first part of this work has shown that CSD1 at neutral pH is in an expanded and flexible conformation without secondary and tertiary structures. Next, we further studied cosolvent effects of protein-stabilizers, polyols and sulfate salts, as well as protein-destabilizers, alcohols, on the conformation of CSD1 monitored by far- and near-UV CD spectroscopy. We found that both groups of cosolvents at high concentration induce highly helical structures of CSD1, but without specific tertiary interactions. Based on the results on the polyols and the sulfate salts, we have suggested that the preferential hydration is one of the thermodynamic forces to induce secondary structures in the denatured state of protein. Variations in isodichroic points of changes in far-UV CD spectrum as functions of cosolvent species and their concentration have exhibited complexity of the processes. The present study implies that protein stability in the presence of cosolvents is often determined by free energy difference between the folded and the highly structured denatured state, not between the folded and the random state.

Animals↗

PubMed1997

Coronary artery perforation with subepicardial hematoma.

Coronary artery perforation is a relatively rare complication in coronary angioplasty. We report the case of a 71-year-old male, who was salvaged by emergency surgery, for cardiogenic shock due to subepicardial hematoma associated with balloon angioplasty. Such a case has not yet previously been reported.

Aged↗

PubMed1997

Urea-induced conformational changes in cold- and heat-denatured states of a protein, Streptomyces subtilisin inhibitor.

Streptomyces subtilisin inhibitor (SSI) is known to exist in at least two distinct denatured states, cold-denatured (D') and heat-denatured (D) under acidic conditions. In the present work, we investigated the manner how increasing urea concentration from 0 to 8 M changes the polypeptide chain conformation of SSI that exists initially in the D' and D states as well as in the native state (N), in terms of the secondary structure, the tertiary structure, and the chain form, based on the results of the experiments using circular dichroism (CD), small-angle X-ray scattering (SAXS) and 1H-NMR spectroscopy. Our results indicate that the urea-induced conformational transitions of SSI under typical conditions of D' (pH 1.8, 3 degrees C) occur at least in two steps. In the urea concentration range of 0-2 M (step 1), a cooperative destruction of the tertiary structure occurs, resulting in a mildly denatured state (DU), which may still contain a little amount of secondary structures. In the concentration range of 2-4 M urea (step 2), the DU state gradually loses its residual secondary structure, and increases the radius of gyration nearly to a maximum value. At 4 M urea, the polypeptide chain is highly disordered with highly mobile side chains. Increasing the urea concentration up to 8 M probably results in the more highly denatured or alternatively the stiffer chain conformations. The conformational transition starting from the N state proceeds essentially the same way as in the above scheme in which D' is replaced with N. The conformational transition starting from the D state lacks step 1 because the D state contains no tertiary structures and is similar to the DU state. The fact that similar conformations are reached at urea concentrations above 2 M from different conformations of D', D, and N indicates that the effect of urea dominates in determining the polypeptide conformation of SSI in the denatured states rather than the pH and temperature.

Bacterial Proteins↗

PubMed1997

Expression of GATA transcription factors in myelogenous and lymphoblastic leukemia cells.

In the hematopoietic lineage, the transcription factors GATA-1 and GATA-2 show restricted and largely overlapping expression profiles, but GATA-2 is uniquely expressed in early hematopoietic progenitors. GATA-3 is found exclusively in T cells of hematopoietic lineage. To clarify whether these expression profiles are preserved or changed during the development of malignancies, we analyzed the expression of GATA factors in the blasts from leukemic children. A total of 18 myelogenous leukemia and 24 lymphoblastic leukemia (ALL) cases were investigated. In the majority of the former cases, GATA-2 mRNA expression and the expression of CD34 and c-kit antigens on leukemic cells were demonstrated. In contrast, GATA-2 mRNA and c-kit antigen could not be detected in CD34-positive cells from ALL patients. GATA-3 mRNA was expressed in all T-ALL cases, but not in any precursor B-ALL. These findings suggest that down-regulation of GATA-2 and expression of GATA-3 are important events for the commitment of cells to lymphoid and T cell lineage, respectively. The expression profiles of GATA factors in leukemic cells are generally consistent with those in their normal counterparts, and thus provide a useful tool to determine the lineage commitment of unclassified leukemia.

Adult↗

PubMed1997

Successful treatment of steroid-resistant severe acute GVHD with 24-h continuous infusion of FK506.

We report our findings in two cases of steroid-resistant severe acute GVHD after allogeneic BMT successfully treated with FK506 (tacrolimus). An 18-year-old female (patient 1) who underwent BMT from an HLA-identical sibling for ALL in first CR, developed generalized erythema and profuse watery diarrhea, which progressed to acute GVHD of grade III severity, resistant to steroid control. After continuous 24-h administration of FK506, the diarrhea improved within 10 days. Patient 2, a 9-year-old girl with AML who underwent unrelated BMT, had skin, gut and liver lesions of acute GVHD grade IV, which did not respond to high-dose steroid therapy. They were controlled, however, by continuous intravenous infusion of FK506. Both patients are still surviving after more than 1 year without any acute GVHD sequelae or signs of chronic illness. The adverse effects of FK506 were mild and tolerable in both cases. Comparison of our findings with those in the literature suggests that it is important to give FK506 at plasma concentrations as high as 25-35 ng/ml by continuous intravenous infusion for extended periods to control steroid-resistant severe acute GVHD.

Acute Disease↗

PubMed1997

Increasing vasoconstrictor response to ergonovine with oxidative injury in canine coronary artery.

BACKGROUND: The effects of oxygen free radicals on coronary vasoreactivity remain unknown. OBJECTIVE: To examine whether oxygen free radicals increase coronary arterial tone and sensitivity to vasoconstrictor stimulation in closed-chest dogs. METHODS: Oxygen radicals were generated by the reaction of xanthine plus xanthine oxidase (XXO) and effects of these substances on the left coronary artery (the percentage diameter change) and on the constrictor effect of ergonovine were examined in vivo in 19 anesthetized, closed-chest dogs by selective coronary angiography. The effects of XXO solution and ergonovine were assessed in a cumulative fashion using 100, 200, and 300 ml XXO and 50, 100, 150, and 200 micrograms ergonovine, in 5 (group I) and 6 dogs (group II), respectively. The effects of XXO on the constrictor responses elicited by 50 micrograms ergonovine were examined in eight dogs (group III). Changes in the vascular endothelium were examined by postmortem electron microscopic examination. RESULTS: Oxidative injury alone produced slight constriction of the coronary artery, but the change was not significant. However, ergonovine-induced vasoconstriction was enhanced after administration of 100 and 200 ml (cumulative amount) XXO solution (P < 0.05, group II versus group III). The enhancement was no longer observed after administration of 300 ml (cumulative amount) XXO solution. Scanning and transmission electron microscopies revealed the formation of blebs and ulceration in the coronary endothelium after administration of XXO solution. CONCLUSION: These results suggest that oxygen radicals can enhance the ergonovine-induced coronary vasoconstriction in a concentration-dependent manner. There seems to be a critical level of oxygen radicals for the production of the effect.

Animals↗

PubMed1997

Decrease in Thy-1 expression on peripheral CD34 positive cells induced by G-CSF mobilization. The Tohoku Children Leukemia Study Group.

In order to ascertain the cytological features of peripheral hematopoietic progenitor cells (PHPC) mobilized after administration of chemotherapeutic agents and G-CSF, lineage- and progenitor cell-specific surface markers on CD34 positive (+) cells were sequentially examined. Nineteen evaluable samples were obtained from a malignant lymphoma, an acute lymphoblastic leukemia and 5 neuroblastoma patients. CD38 and HLA-DR were respectively expressed on more than 95% and approximately 85% of CD34+ PHPC cells. CD19 was also expressed on the majority and CD117 on 10 to 20% of the CD34+ cells. The most striking finding was that the Thy-1(CDw90)+/CD34+ population was decreased at the peak of mobilization of CD34+ cells as compared to the early phase after G-CSF administration (approximately 20% vs. 60%). These results suggest that decrease in Thy-1 expression on CD34+ cells is related to mechanisms easing CD34+ cell mobilization to the peripheral blood.

Antigens, CD34↗

PubMed1996

The methanol-induced globular and expanded denatured states of cytochrome c: a study by CD fluorescence, NMR and small-angle X-ray scattering.

Methanol-induced conformational transitions of cytochrome c(cyt c) at acidic pH values were investigated with a combined use of far and near-UV CD, fluorescence, NMR spectroscopy and small-angle X-ray scattering. At pH 3.0 and 25 degrees C, two methanol-induced non-native states were characterized. First, addition of methanol up to 25% (v/v) induced a compact denatured conformer (I(M)). Further addition of methanol transformed this I(M) state into the expanded and highly helical denatured state (H). The existence of the I(M) state was shown by the discrepancy in transition curves obtained from the ellipticity at 222 nm, the ellipticity at 282 nm, the tryptophan fluorescence monitored at 350 nm and the native peak intensity of the (1)H NMR spectrum. These CD, fluorescence and NMR results showed that the I(M) state has no specific tertiary structure but has a secondary structural content and tryptophan environment similar to those in the native state. The radius of gyration of the I(M) state, 17.7 angstroms, obtained from the Guinier plot of the small-angle X-ray scattering data was significantly smaller than that of the acid-denatured state (30.1 angstroms) and was closer to that of the native state (14.6 angstroms), showing that the I(M) state is compact. The Kratky plot for the I(M) state exhibited a bell-shaped profile, indicating a globular conformation. These structural features indicate that the structure of the I(M) state is quite similar to that of the anion-induced molten globule state of this protein. Furthermore the alcohol-denatured state (H) of cyt C in 60% (v/v) methanol was structurally characterized. Though the H state had a helical content much higher than the native state monitored by far-UV CD spectroscopy, the radius of gyration, 31.7 angstroms, was similar to that of the acid-denatured state, showing that this H state is an expanded denatured state. The Kratky plot for the H state did not show a clear peak, indicating a chain-like conformation. Thus we conclude that the H state has an expanded and chain-like conformation with a high helical content. Finally, we constructed a phase diagram of cyt c involving the native, I(M), acid-denatured and H states against pH and the methanol concentration. The result indicates that the I(M) state is found in the pH range from 2.5 to at least 4.5 with a pH-dependent optimum methanol concentration of 10 to 40%.

Circular Dichroism↗

PubMed1996

Relationship of feeding modality to clinical features in Japanese infants with idiopathic neonatal hepatitis of the non-familial form.

To clarify the relationship between idiopathic neonatal hepatitis and feeding type, that is, formula-milk feeding and breast-milk feeding, the medical records of 100 patients (68 male and 32 female babies) with idiopathic neonatal hepatitis of non-familial form referred to the medical centers of Akita University and Tohoku University during the past 18 years were reviewed. The patients were divided into two 9 year periods (1975-83 and 1984-92), and their clinical features were analyzed in terms of feeding type and sex. The number of patients enrolled decreased from 69 in the first half to 31 in the second half. The number of male patients dropped from 53 to 15, although the number of female patients (n = 16) remained the same in both 9 year periods. The frequency of formula-milk feeding significantly decreased in the second half (42/69 to 6/31, P < 0.01). Compared with the expected numbers of patients in the second half, calculated on the changes in the live birth population and feeding modality between the two halves, the actually enrolled numbers of patients in the second half were less in both the male and the formula-milk fed groups (x0.35 and x0.22), whereas the numbers of female and breast-milk feeding groups were close to the expected values (x1.26 and x1.08). When sex and feeding modality were combined, the formula-milk fed male group showed the lowest value (x0.10), and the breast-milk fed female group showed the highest value (x2.85). In conclusion, feeding type, especially in combination with gender, might be one causative factor in the occurrence of idiopathic neonatal hepatitis.

Breast Feeding↗

PubMed1996

Mutations of the Epstein-Barr virus LMP-1 oncogene in a 10-year-old Japanese girl with nasopharyngeal carcinoma.

A 10-year-old patient with nasopharyngeal carcinoma (NPC) was studied for mutations within the carboxy-terminal portion of the Epstein-Barr virus (EBV) latent membrane protein (LMP)-1 gene. The EBV genome, defined as type A, was detected in biopsied tumor specimens by Southern hybridization with specific probes. Sequence analysis of the carboxy-terminal part of the LMP-1 gene revealed no deletions but seven single-base substitutions, four of which were found to be identical to those previously detected in codons for amino acids 322 to 366 in the Chinese NPC CAO. Although yet unresolved, the observed mutations may be associated with the pathogenesis of NPC.

Blotting, Southern↗

PubMed1996

Isolation and characterization of two monoclonal antibodies that recognize different epitopes of the human c-kit receptor.

After immunizing mice with a human megakaryoblastic leukemia cell line, M-MOK, we obtained two monoclonal antibodies which recognize the human c-kit receptor. The monoclonal antibodies, designated MTK1 and MTK2, were found to specifically recognize Balb/3T3 cells transfected with human c-kit cDNA and not parent Balb/3T3 cells while showing different immunological, biochemical and biological behaviors. Both allowed visualization of the 140 kDa c-kit protein by Western blot analysis, but MTK1 detected only positive band with non-reducing conditions for sodium dodecyl sulfate-polyacrylamide gel electrophoresis. MTK1 partially inhibited the stem cell factor (SCF) induced proliferation of M-MOK cells, whereas, MTK2 was without effect. MTK1 also inhibited the bone marrow derived colony forming unit granulocyte/macrophage (CFU-GM) formed by granulocyte-macrophage colony stimulating factor (GM-CSF) and SCF. Not only anti-CD34 antibodies (HPCA-1) but also MTK1 could be shown to concentrate bone marrow CFU-GM and burst forming unit erythroid (BFU-E) effectively. The presently described monoclonal antibodies may therefore be useful for functional analysis of the ligand binding domain of the human c-kit receptor, as well as for further classification of hematopoietic stem cells in addition to the CD34 positive cells.

Animals↗

PubMed1996

IL-2 receptor gamma chain expression on CD34 positive hematopoietic progenitor cells from bone marrow and cord blood.

The IL-2 receptor (IL-2R) gamma chain is shared among receptors for IL-4, IL-7, IL-9 and IL-15 as well as IL-2. In order to clarify the functional role of these cytokines interacting with the common gamma chain in human early hematopoiesis, we studied expression of the IL-2R gamma chain on purified CD34 positive cells from bone marrow and cord blood. Broad populations of bone marrow mononuclear cells were all found to express the IL-2R gamma chain. CD34 positive cells were purified by CD34 monoclonal antibodies and immunomagnetic beads as representative hematopoietic progenitor cells. It was established that only 38 +/- 10% of CD34 positive bone marrow cells (n = 5) and 35 +/- 12% of CD34 positive cord blood cells (n = 11) expressed the IL-2R gamma chain. CD34(+) IL-2R gamma chain(+) and CD34(+) IL-2R gamma chain(-) cells fractionated by cell sorting were subjected to clonogenic assays that showed granulocyte-macrophage colony-forming cells (CFU-GM) were present evenly in both fractions, whereas erythroid burst-forming cells (BFU-E) were enriched in the CD34(+) IL-2R gamma chain(-) fraction approximately two- to six-fold as compared with CD34(+) IL-2R gamma chain(+) fraction. Such clonogenic features did not differ between the bone marrow and cord blood cases. These results indicate that CD34(+) IL-2R gamma chain(-) cells contain immature cells already committed to the erythroid lineage.

Adult↗