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Biomedical subjects

K Kikuchi

Publications and source records attributed to K Kikuchi.

At least 235 records · Page 13Linked to original sources
PubMed2000

[Exhaled nitric oxide].

We introduce the standard method of measurement of nitric oxide recommended by American thoracic society in 1999 and report the results of exhaled NO and nasal NO in patients with obstructive sleep apnea syndrome(OSAS). Our data showed lower exhaled NO output in the patients with OSAS than that of normal volunteers(NV) and that of patients with simple obesity(SO). On the other hand, nasal NO in the OSAS patients is higher than that of NV and that of SO patients. Also, there were significant relationships between apnea index and exhaled NO and between desaturation during sleep and nasal NO. These findings suggested that NO from lower and upper airway will be a non-invasive maker of sleep disordered breathing in future.

Breath Tests↗
PubMed2000

[Effect of radiofrequency catheter ablation on autonomic tone in patients with common atrial flutter: difference depending on the site of ablation].

OBJECTIVES: Radiofrequency catheter ablation (RFCA) of the inferior vena cava-tricuspid annulus isthmus has become an effective procedure for radical treatment of common atrial flutter. This site is close to the right atrial posteroseptal region, so vagal denervation after slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia can also occur after the procedure. To confirm this hypothesis, we tested whether autonomic disturbance can occur after RFCA in 16 patients with common atrial flutter. METHODS: Parameters of the autonomic function were measured using several components of the time domain analyses and power spectra of heart rate variability calculated from Holter recordings and the baroreflex sensitivity. Patients were divided into 2 groups based on the location of the ablated area: the isthmus group (9 patients) with the ablated area of the exact isthmus, and the posteroseptal group (7 patients) with the ablated area slightly shifted toward the right atrial posteroseptal position. All values after RFCA were compared with those before RFCA, and the ratio (after/before) was compared between the groups. The correlation between the ratio and cumulative delivered energy was also studied for each parameter. RESULTS: After RFCA, the heart rate increased, and the SD, rMSSD and pNN50 decreased significantly in the posteroseptal group, whereas no significant changes occurred in the isthmus group. The high frequency of the power spectra decreased after RFCA only in the posteroseptal group, and the ratio was significantly smaller in the posteroseptal group compared to the isthmus group. A significant reverse correlation between the ratio of the high frequency and cumulative energy was observed only in the posteroseptal group. The baroreflex sensitivity tended to be diminished after RFCA only in the posteroseptal group. CONCLUSIONS: Vagal denervation can occur after RFCA of common atrial flutter when the ablation site is shifted toward the right atrial posteroseptal region.

Atrial Flutter↗
PubMed2000

[Acute respiratory failure due to inhalation of aerosol water proof agent].

A 65-year-old laundryman who suffered from cough, fever, and dyspnea was admitted to our hospital. Laboratory finding disclosed leukocytosis of peripheral blood, elevated CRP, and hypoxemia. Chest X-ray films showed diffuse interstitial nodular shadows in both lungs. The patient was given a diagnosis of pneumonia and treated with oxygen inhalation, antibiotics, and steroids. The abnormal findings disappeared rapidly, and the patient was discharged after 11 days. However, he was readmitted 3 days later with the same chest X-ray film findings as observed before. Examination of bronchoalveolar lavage fluid disclosed an increased neutrophil count. Transbronchial lung biopsy specimens revealed alveolar collapse, which was considered to have contributed to hypoxemia and ventilation perfusion mismatch. However, no signs of infiltration of inflammatory cells into alveolar walls, or of acute-phase interstitial edema, were observed. Environmental studies supported a strong relationship between the patient's symptoms and clothes waterproofing agent. From these findings, we reasoned that the inhalation of aerosol waterproofing agent containing fluoroplastics can induce respiratory failure.

Acute Disease↗
PubMed2000

Protamine dissociation before decondensation of sperm nuclei during in vitro fertilization of pig oocytes.

The correlation between morphological changes and the dynamics of protamine in boar sperm chromatin during in vitro fertilization of pig oocytes matured in vitro was assessed. For this purpose, protamine was purified from boar sperm nuclei and an antiserum against protamine was developed. After affinity purification, the antiserum reacted exclusively with boar protamine during western blotting, showing no crossreactivity with core histones. Immunohistochemical evaluation revealed that only fully developed spermatid nuclei in boar testes stained strongly with the antiserum. When pig oocytes matured in vitro were fertilized in vitro, sperm penetration was observed in 37% of oocytes at 2 h after insemination and the penetration rate increased to 99% by 5 h after insemination, accompanied by an increase in polyspermic penetration. Paraffin wax sections of the inseminated oocytes were examined by immunohistochemical analysis with the antiserum. The proportion of condensed sperm nuclei that reacted with the antiserum was 87% of the sperm nuclei that penetrated by 2 h after insemination, and this decreased to 20 and 13% at 3 and 5 h after insemination, respectively. However, none of the decondensing sperm nuclei or male pronuclei reacted with the antiserum during the entire insemination period. These results indicate that a specific antiserum against boar protamine can be raised and, using this serum, it has been demonstrated that protamine is dissociated from boar sperm nuclei before decondensation during in vitro fertilization.

Analysis of Variance↗
PubMed2000

[A randomized long-term comparative study of clinical efficacy of alpha 1-blocker with or without antiandrogen therapy for benign prostatic hyperplasia: focusing on improvement of I-PSS].

This study was conducted to examine the efficacy of administration of tamsulosin hydrochloride alone or in combination with chlormadinone acetate (CMA) against lower urinary tract symptoms for a period of 52 weeks in 33 patients with benign prostatic hyperplasia. The patients were randomly allocated into a group administered tamsulosin alone and a group administered tamsulosin in combination with CMA. Based on the assessment of the total I-PSS (International Prostate Symptom Score), significant symptomatic improvement was noted 4 weeks after the commencement of drug administration in the tamsulosin + CMA group, whereas no significant improvement was observed in the tamsulosin group. Both irritative and obstructive bladder symptoms improved significantly at any time of assessment after 4 weeks of drug administration in the tamsulosin + CMA group; however, significant improvement was noted only at week 16 and week 52 for irritative symptoms and at week 16 for obstructive symptoms in the tamsulosin group. In particular, obstructive symptoms showed significant improvement at week 4 in the tamsulosin + CMA group, as compared with that in the tamsulosin group. The average value of peak urinary flow rate was significantly increased in the tamsulosin + CMA group (10.4 ml/s to 15.6 ml/s) as compared with that in the tamsulosin group (8.5 ml/s to 10.5 ml/s). These findings indicate that combined administration of tamsulosin and CMA resulted in early improvement of lower urinary tract symptoms in these patients. Long-term combined administration of tamsulosin and CMA thus appears to be a promising treatment strategy for the improvement of obstructive symptoms and peak urinary flow rate, particularly, 16 weeks onward after administration in patients with benign prostatic hyperplasia.

Adrenergic alpha-Antagonists↗
PubMed2000

[A case of pulmonary tuberculosis diagnosed by DNA amplification methods from transbronchial lung biopsy materials].

The hybridization assay using polymerase chain reaction (PCR) is useful for rapid detection of Mycobacterium tuberculosis (M. tuberculosis). A 77-year-old female was admitted to our hospital complaining of cough, and examination of the sputum culture showed M. tuberculosis. Her chest X-ray showed a variety of abnormal shadows, such as a cavity lesion, multiple coin lesions, and infiltrates. Malignant disease was also suspected to be involved, with the complication of pulmonary tuberculosis. Specimens were obtained by transbronchial lung biopsy (TBLB) from coin lesions. The hybridization assay using PCR on the TBLB specimens showed M. tuberculosis gene expression. She was treated with anti-tuberculous drugs. All shadows in her chest X-ray were improved six months after admission. She was remained well without recurrence for more than two years after admission. The hybridization assay using PCR with TBLB specimens is useful for the detection of M. tuberculosis.

Aged↗
PubMed1999

Quantitative determination of a potent lipopolysaccharide antagonist, E5564, in rat and dog plasma by high-performance liquid chromatography with fluorescence detection.

The assay method was established for the quantification of a potent lipopolysaccharide (LPS) antagonist, E5564, in rat and dog plasma using HPLC. E5564 and the I.S. (an analogue of E5564) were extracted and derivatized with 9-Anthryldiazomethane (ADAM reagent) to be given fluorescence. LC-MS analysis indicated that single molecule of E5564 was coupled with two molecules of ADAM reagent at one on each of the phosphorus groups. After solid-phase extraction, ADAM derivatives of E5564 and the I.S. were separated on an ODS column using methanol/ethanol containing sodium acetate as a mobile phase at 1.2 ml/min (gradient elution), and detected by a fluorescence detector (excitation: 254 nm, emission: 415 nm). The intra-day and inter-day precision were less than 14.4%, and accuracy were within +/-13.0% in the concentration range of 30 to 20,000 ng/ml plasma in both species. E5564 was stable for at least 13 days in rat and dog plasma at -20 degrees C, and the processed sample was stable for up to 14 days at 4 degrees C. This validated method was successfully applied to the evaluation of the pharmacokinetics of E5564 in rats and dogs after single bolus intravenous doses.

Animals↗
PubMed1999

Molecular cloning and characterization of a novel dual-specificity protein phosphatase possibly involved in spermatogenesis.

Dual-specificity protein phosphatases (DSPs) play roles in the regulation of mitogenic signal transduction for extracellular stimulation and the cell cycle. In the present study, we identified a novel DSP, termed TMDP (testis- and skeletal-muscle-specific DSP). Nucleotide sequence analysis of TMDP cDNA indicated that the open reading frame of 597 bp encodes a protein of 198 amino acid residues with a predicted molecular mass of 22.5 kDa. The deduced amino acid sequence contains a motif for a conserved catalytic domain of DSPs and shows highest similarity to human Vaccinia HI-related phosphatase (45.5% identity) but low homology to the mitogen-activated protein kinase phosphatase and CDC25 subfamilies of DSPs. Recombinant TMDP protein exhibited intrinsic phosphatase activity towards both phospho-seryl/threonyl and -tyrosyl residues of myelin basic protein, with similar specific activities in vitro. Northern-blot analysis revealed that TMDP is most abundantly expressed in the testis. The expression in the testis is characterized as follows: (i) TMDP mRNA first appeared 3 weeks after birth, corresponding to the time that meiosis begins; (ii) TMDP mRNA was abundant in fractionated spermatocytes and round spermatids; and (iii) hybridization in situ showed that the TMDP mRNA is localized in spermatocytes and/or spermatids in seminiferous tubules. These data demonstrate that TMDP is a novel DSP abundantly expressed in the testis and suggest that TMDP may be involved in the regulation of meiosis and/or differentiation of testicular germ cells during spermatogenesis.

Amino Acid Sequence↗
PubMed1999

Fluorescent Indicators for Imaging Nitric Oxide Production.

The membrane-permeating indicator DAF-FM DA is transformed by intracellular esterases into the highly water-soluble dye DAF-FM, which traps NO produced by NO synthase (NOS) to yield a highly fluorescent triazole compound in cells (see schematic diagram). Monitoring with a fluorescence microscope should allow direct identification of intracellular production and location of NO.

Journal Article↗
PubMed1999

Identification of soluble interleukin-4 receptor in rat glomerular epithelial cells(1).

Interleukin (IL)-4, a pleiotropic cytokine involved in many glomerular diseases, is regulated positively by membrane-bound IL-4R (mIL-4R) and negatively by soluble IL-4R (sIL-4R). Because natural sIL-4R has been documented only in mice, we undertook this study in rats to determine whether they, too, express sIL-4R, particularly in kidney cells. A pair of IL-4R primers was designed for this purpose and used in the polymerase chain reaction. As a result, sIL-4R was found not only in rats spleen cells but also in their glomerular epithelial cells (GEC). Sequence analysis revealed that the mRNA of rat sIL-4R has a 75-bp insert sequence. This insert generated a termination TGA codon upstream from the transmembrane region, resulting in formation of the sIL-4R. Subsequent screening of the kidney cDNA library enabled us to obtain the whole 3605-bp cDNA of sIL-4R; the full-length 3530-bp mIL-4R cDNA was also identified as a much longer sequence than previously published. Among the total 39 clones positive for IL-4R, two were confirmed as sIL-4R, and 37 clones were positive for mIL-4R. Next, the translated portion of sIL-4R cDNA was constructed into an expression vector, enabling us to obtain a recombinant sIL4R-myc fusion protein. By using this recombinant sIL-4R, we proved that sIL-4R can antagonize the IL-4-induced proliferation of spleen cells. Present study demonstrated that sIL-4R is expressed in kidney cells and antagonistically functional.

Animals↗
PubMed1999

Novel Fluorescent Probes for Singlet Oxygen.

The first fluorescent chemical traps for (1)O(2) have been developed. DPAXs react specifically with (1)O(2) to yield the corresponding endoperoxides, DPAX-EPs (see scheme; X = H, Cl, F). DPAXs scarcely fluoresce, while DPAX-EPs are strongly fluorescent. Since the fluorescence of these probes is unaffected by H(2)O(2), superoxide, and nitric oxide, they are useful for the selective detection of (1)O(2) in biological systems.

Journal Article↗
PubMed1999

Identification of natural antigenic peptides of a human gastric signet ring cell carcinoma recognized by HLA-A31-restricted cytotoxic T lymphocytes.

Peptides of human melanomas recognized by CD8+ CTLs have been identified, but the nature of those of nonmelanoma tumors remains to be elucidated. Previously, we established a gastric signet ring cell carcinoma HST-2 and HLA-A31 (A*31012)-restricted autologous CTL clone, TcHST-2. In the present study, we determined the natural antigenic peptides of HST-2 cells. The purified preparation of acid-extracted Ags was submitted to the peptide sequencer, and one peptide, designated F4.2 (Tyr-Ser-Trp-Met-Asp-Ile-Ser-Cys-Trp-Ile), appeared to be immunogenic. To confirm the antigenicity of F4.2 further, we constructed an expression minigene vector (pF4.2ss) coding adenovirus E3, a 19-kDa protein signal sequence plus F4.2. An introduction of pF4.2ss minigene to HST-2 and HLA-A31(+) allogeneic tumor cells clearly enhanced and induced the TcHST-2 reactivity, respectively. Furthermore, when synthetic peptides of F4.2 C-terminal-deleted peptides were pulsed to HST-2 cells, F4.2-9 (nonamers), but not F4.2-8 or F4.2-7 (octamer or heptamer, respectively), enhanced the reactivity of TcHST-2, suggesting that the N-terminal ninth Trp might be a T cell epitope. This was confirmed by lack of antigenicity when using synthetic substituted peptides as well as minigenes coding F4.2 variant peptides with Ala or Arg at the ninth position of F4.2. Meanwhile, it was indicated that the sixth position Ile was critically important for the binding to HLA-A31 molecules. Thus, our data indicate that F4.2 may work as an HLA-A31-restricted natural antigenic peptide recognized by CTLs.

Amino Acid Sequence↗
PubMed1999

Cultured murine parenchymal liver cells induce differentiation of bone marrow cells to macrophage-like cells which present antigen to Th1 clones but inhibit their proliferation by nitric oxide and prostaglandins.

Suppressor cells were developed from nylon wool nonadherent CD4(-)8(-)TCRbeta(-) bone marrow cells cocultured with parenchymal liver cells for 2.5 days. The major suppressor cell population consisted of nylon wool/plastic dish-adherent, phagocytic Mac-1(+) CD3(-)4(-)8(-) cells (Ad cells), with 34% of the Ad cells being F4/80(+). These Ad cells suppressed the antigen-specific proliferation of Th1 clones in an MHC-nonrestricted manner. They showed a dose-dependent increase in suppressive activity, with both NO and PGE(2) levels in the culture supernatant rising with Ad cell concentration. OVA-pulsed Ad cells (OVA-Ad cells) were found to stimulate IFN-gamma production, resulting in an elevation of the NO and PGE(2) levels in wells containing OVA-specific Th1 clones. No DNA synthesis by these clones was detected in the absence of N(G)-monomethyl-l-arginine and indomethacin, yet the proliferation of the clone was induced in the presence of these chemicals. As proliferation is inhibited by NO and PGE(2) the Ad cells give the impression that they have no antigen-presenting function. This function is MHC-class-II-restricted. If cells such as Ad cells did actually exist in the hepatic sinusoid, they could by their nature play a major role in inducing the early emerging unresponsiveness of T cells in the liver which we reported in a previous paper.

Animals↗
PubMed1999

T1 Breast Cancer Associated with Von Recklinghausen's Neurofibromatosis.

A rare case of breast cancer associated with von Recklinghausen s neurofibromatosis is reported. This case and review of the literature illustrate the problems of clinical diagnosis. A 66-year-old woman who had undergone sigmoidectomy for sigmoid colon cancer two years previously, was admitted to the hospital because of a left breast skinretraction in October, 1998. The patient had von Recklinghausen fs disease (neurofibromatosis type 1). The TNM clinical staging was T1cN0M0. Modified radical mastectomy was performed. The histopathological diagnosis of the breast tumor was invasive ductal carcinoma and the skin tumor was neurofibroma. The pTNM pathological staging was pT1cN1aM0. Among patients similar to our case, almost all were staged higher than T2. This may be because multiple neurofibromas obscure breast mass at palpation, leading to delayed detection of the cancer. Systemic and careful exploration is essential for patients with von Recklinghausen's neurofibromatosis to detect breast cancer at an early stage.

Journal Article↗
PubMed1999

The spiroketals containing a benzyloxymethyl moiety at C8 position showed the most potent apoptosis-inducing activity.

The spiroketals containing a benzyloxymethyl moiety at the C8 position showed the most potent apoptosis-inducing activity, whereas its analogous compounds lacking any substituent at C8 or possessing ones other than the benzyloxymethyl moiety at C8 were all much less active. These results strongly suggest an important role of the benzyloxymethyl moiety linked to the C8 oxygen atom.

Apoptosis↗