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Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 541 records · Page 30Linked to original sources
PubMed1992

[Dyspnea sensation during resistive loading].

To examine the relationship among the sensation of dyspnea, the respiratory muscle oxygen consumption (VO2 resp), minute ventilation and occlusion pressure, seven normal volunteers were studied during incremental dead space loading induced hyperventilation with and without inspiratory resistive load. Although the sensation of dyspnea and VO2 resp at the same level of minute ventilation increased with an increase in resistance, there appeared to be a unique relationship among the sensation of dyspnea, VO2 resp and occlusion pressure, which was not affected by inspiratory resistive loading from 0 to 20 cmH2O/l/sec. These results show that the ventilatory command signal is closely related to the dyspnea sensation. We also found that during incremental dead space loading the quality of the sensation changed relatively quickly at some point, where tidal volume was maximum with each resistive loading and the breathing pattern changed. In the other experiment, the functional residual capacity (FRC) decreased during inspiratory resistive and elastic loading. Because the decreased FRC was associated with the decrease in the dyspnea sensation, it was speculated that the subject decreased his FRC through a cortical response so that the sensation of dyspnea during loading decreased.

Airway Resistance↗
PubMed1992

Estimation of the following cardiac output using sympathetic tone and hemodynamics for the control of a total artificial heart.

A sympathetic neurogram is potentially useful for the development of a real time total artificial heart (TAH) control system. We used sympathetic tone and hemodynamic derivatives to estimate the following cardiac output in acute animal experiments using adult mongrel dogs. Moving averages of the mean left atrial pressure and mean aortic pressure were used as parameters of the preload and afterload, respectively. Renal sympathetic nerve activity (RSNA) was employed as a parameter of sympathetic tone. Equations for the following cardiac output were calculated using multiple linear regression analysis of the time series data. A significant correlation was observed between the estimated and following measured cardiac output. These results suggest the potential usefulness of the sympathetic neurogram for the real time TAH automatic control system.

Animals↗
PubMed1992

[Myocardial infarct size and left ventricular function in diabetic patients].

We determined the relationship between myocardial infarct size (MIS) estimated by electrocardiographic measurements of infarct size (QRS score) and left ventricular function estimated by angiographically left ventricular ejection fraction (EF). MIS estimated by QRS score were the same in both DM and NDM (5.2 +/- 0.5 vs 4.3 +/- 0.4: p greater than 0.05), but EF in DM was significantly lower than in NDM (43.1 +/- 1.4 vs 51. +/- 1.1%: p less than 0.05). There was clear linear correlation between MIS and EF in NDM (r = -0.71) but not in DM. EF was much lower in DM than in NDM even at the same QRS score level. There were no differences in blood pressure, serum lipid levels, age, and the site of the myocardial infarction. The most likely explanation for this appears to be due to a previous left ventricular disease in DM.

Aged↗
PubMed1992

Mass screening of neuroblastoma in Sapporo City, Japan.

In Sapporo City a mass screening program for neuroblastoma aiming at 6-month-old infants has been performed since April 1981. By March 1990, 136,001 infants were screened; 26 true-positive cases of neuroblastoma and six false-negative cases were detected. The sensitivity of the mass screening method was about 80% throughout the 9 years. During the 9-year period, a total of nine children with neuroblastoma who were not screened were also identified. Clinical stage, age at diagnosis, and survival rate for the 32 patients who were screened (26 true positives and six false negatives) were much more favorable than those for the nine patients who were not screened. A remarkable decrease in the incidence of cases of neuroblastoma with advanced clinical stages over 1 year of age, especially among children 1-4 years of age, was noted after the start of the mass screening. The mortality from this tumor in children up to 4 years of age significantly decreased after the start of the urinary screening program. Rescreening at 14 months of age was begun in April, 1991 in Sapporo City. Performing two screening examinations decreases the probability of overlooking a patient. Thus, it is expected that tumors missed on the first screening would be detected by the second screening.

Biomarkers, Tumor↗
PubMed1992

Effects of opioid peptides on the tumoricidal activity of spleen cells from nude mice with or without tumors.

The present study was designed to explore the effects of opioid peptides on the immune systems of intact nude mice and nude mice bearing human ovarian cancer cells (KF). When spleen cells from intact nude mice were incubated with medium alone, a significant ability of spleen cells to lyse the KF cells was not observed. However, incubation of the spleen cells with 1 microM beta-endorphin or 1 microM alpha-endorphin induced a significant lytic activity on the KF cells. The control-level lytic activity was increased significantly to about 4.5-fold by 1 microM beta-endorphin and about 3.7-fold by 10 microM met-enkephalin. These results suggest that opioid peptides play a crucial role in cellular immunity. Thus, we examined plasma levels of beta-endorphin in patients with ovarian or uterine carcinoma. The plasma beta-endorphin levels in patients with ovarian or uterine carcinoma were significantly higher (more than twofold) than those of age-matched healthy women.

Adult↗
PubMed1992

Studies on blood coagulation-fibrinolysis system regarding kallikrein-kinin system in the utero-placental circulation during normal pregnancy, labor and puerperium.

In our previous study (Adv. Exp. Med & Biol., 247B. 569. 1989, 198B. 41. 1986, blood & vessel, 17: 51. 1986), we reported on the mechanism of coagulation-fibrinolysis system and kallikrein-kinin system in the utero-placental circulation during normal pregnancy, labor and puerperium. The samples were collected from the uterine artery (UA), uterine vein (UV) and peripheral vein (PV). In this study, we tried to elucidate the mechanism of coagulation-fibrinolysis with relation to kks by measuring of Thrombin/Antithrombin III complex (TAT), tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI) complex (tPA.PAI.C), active plasminogen activator inhibitor 1 (active PAI), alpha 2-plasmin inhibitor/plasmin complex (PIC). In 20 normal pregnant women, the levels of TAT, tPA.PAI.C and active PAI significantly increased the first trimester (TAT 4.31 +/- 2.05 ng/ml, tPA.PAI.C 39.52 +/- 17.34 ng/ml, active PAI 39.58 +/- 15.29 ng/ml, n = 20 M +/- SD P < 0.001) to the third trimester (TAT 6.39 +/- 1.93 ng/ml, tPA.PAI.C 57.94 +/- 30.80 ng/ml, active PAI 304.24 +/- 148.64 ng/ml, n = 20 M +/- SD P < 0.001) as compared with those of non-pregnant women (TAT 1.60 +/- 0.89 ng/mg, tPA.PAI.C 11.72 +/- 4.59 ng/ml, active PAI 11.53 +/- 7.48 ng/ml, n = 16 M +/- SD). In utero-placental circulation, the levels of TAT significantly increased (TAT 22.12 +/- 20.03 ng/ml n = 20 M +/- SD P < 0.001) in UV, and tPA.PAI.C and PIC. markedly increased (tPA.PAI.C 93.38 +/- 56.05 ng/ml, PIC 1.03 +/- 0.94 micrograms/ml n = 20 M +/- SD P < 0.02) in UV, but active PAI markedly decreased (active PAI 244.18 +/- 87.55 ng/ml n = 20 M +/- SD P < 0.02) as compared with those in PV (TAT 6.1 +/- 2.09 ng/ml, tPA.PAI.C 59.34 +/- 18.99 ng/ml, PIC 0.49 +/- 0.24 micrograms/ml, active PAI 349.14 +/- 157.34 ng/ml, n = 20 M +/- SD). These findings suggest that the significant increase in those complexes in UA has produced a deposition of fibrin clots in the area in contact with utero-placental blood vessel, although the marked increase in tPA.PAI.C and PIC incompletely inhibited the fibrinolytic activity of tPA by the active PAI. The kks shows a consumption of prekallikrein, LMW-kininogen and HMW-kininogen, and an overproduction of kinin in UV.

Antithrombin III↗
PubMed1992

Studies of blood coagulation-fibrinolysis regarding kallikrein-kinin system in severe preeclampsia.

UNLABELLED: In our previous study 1), 2), 3) we reported the changes of coagulation-fibrinolysis, kallikrein-kinin system and kininase in preclampsis. In this study, we tried to obtain systemic information of chronic DIC status with regard to kallikrein-kinin system in severe preeclampsia. This systemic information was evaluated in 20 cases of normal gravidas from 28 to 42 weeks of gestation as a control by measuring plasma Thrombin/Antithrombin III complex (TAT), tissue plasminogen activator (tPA) plasminogen activator inhibitor (PAI) complex, active plasminogen inhibitor-1 (active PAI), 2PI plasmin complex (PIC). RESULTS: The levels of plasma TAT and tPA significantly increased (TAT = 10.9 +/- 8.3 ng/ml n = 24 M +/- SD P < 0.02, tPA = 6.1 +/- 3.2 ng/ml n = 10 M +/- SD P < 0.01), tPA PAI C and active PAI markedly increased (tPA PAI C = 85.07 +/- 50.01 ng/ml n = 24 P < 0.05, active PAI = 407.4 +/- 166.0 ng/ml n = 24 P < 0.205), and PIC and D-dimer = 435.1 +/- 145.2 ng/ml n = 8 M +/- SD P < 0.001) in severe preeclampsia as compared with those of normal values (TAT = 6.1 2.0 ng/ml, tPA = 3.6 +/- 1.5 ng/ml, tPA PAI C = 57.9 +/- 30.8 ng/ml, active PAI = 304.2 +/- 148.6 ng/ml, PIC = 0.49 +/- 0.24 mg/ml, D-dimer = 282.9 +/- 75.3 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗
PubMed1992

[67Ga scintigraphic study of a case of recurrent extra-abdominal desmoid tumor].

A case of extra-abdominal desmoid tumor was studied with 67Ga scintigraphy. Extra-abdominal desmoid tumors show an aggressive clinical course with tendency of recurrence in high percentage. On 67Ga scintigraphy, our case revealed a hot spot which is useful of recurrence. 67Ga scintigraphic study was useful in searching for local and recurrence after surgery.

Adolescent↗
PubMed1992

[In vitro and in vivo effects of ginsenoside Rh2 on the proliferation of serous cystadenocarcinoma of the human ovary].

Inhibition of human ovarian cancer cell proliferation in vitro and in vivo by Ginsenoside Rh2(Rh2) isolated from Red Ginseng was examined by using a cell line (HRA) derived from ascites of a patient with serous cystadenocarcinoma of the ovary. The HRA cell proliferation in vitro was inhibited in a dose-dependent manner with between 10 and 100 microM of Rh2. The uptake of radiolabeled precursors (3H-thymidine, 3H-uridine, and 3H-varine) by HRA cells was also inhibited in a dose-dependent manner with between 30 and 100 microM of Rh2. The growth of HRA cells transplanted into nude mice was not significantly inhibited by Rh2 alone. On the other hand, when cisplatin was administered together with 10 microM, 30 microM, or 50 microM Rh2, the growth of HRA cells was inhibited 31 and 35 days after tumor inoculation. Survival was also prolonged when cisplatin was administered with 10 microM and 30 microM Rh2. These results suggest that there is a synergistic effect between cisplatin and Rh2.

Animals↗
PubMed1992

[Closure of median sternotomy incision with EPTFE sutures].

EPTFE (CV-0) suture was utilized for closure of median sternotomy incision in 100 patients under 6 years of age who underwent open heart surgery. During 3 years follow up, except for one dislocation of sternum, all patients have healed without complication. EPTFE suture is swanged to a needle that has the same diameter as the thread, which reduces bleeding from the needle hole. It is radiologically lucent, and therefore does not disrupt chest X-ray, angiography or MRI investigations, in contrast to sternal wires. In addition, in the case of life threatening postoperative complication, EPTFE suture allows rapid and simple access to the heart, without the need to cut wires. We concluded that EPTFE suture can be utilized for closure of median sternotomy in patients under the age of six, without an increased risk of postoperative or long-term complications.

Child, Preschool↗
PubMed1991

Site-specific cleavage of natural mRNA sequences by newly designed hairpin catalytic RNAs.

The negative strand of tobacco ringspot virus satellite RNA is a self-cleaving RNA. Its catalytic domain and substrate domain have been identified, and the catalytic domain has been named hairpin catalytic RNA. Here we report the construction of a plasmid containing a modified hairpin catalytic RNA sequence that can be transcribed in vitro. Because this plasmid has two specific restriction enzyme recognition sites at both ends of the substrate binding site in the catalytic RNA sequence, it is possible to construct new plasmids by substituting different sequences in the substrate binding site. Using this plasmid, synthetic DNA, and in vitro transcription, we obtained three ribozymes designed to cleave Escherichia coli prolipoprotein signal peptidase (lsp) mRNA at specific sites. All three ribozymes cleaved the lsp mRNA sequence in vitro at the specific sites, and two of them cleaved it efficiently. Kinetic analyses showed that one had a higher kcat/Km value than that of the well-known hammerhead ribozyme. Problems associated with attaining the goal of expressing these ribozymes in vivo also are discussed.

Bacterial Outer Membrane Proteins↗
PubMed1991

Role of bone marrow cells in autoantibody production and lymphoproliferation in the novel mutant strain of mice, CBA/KlJms-lprcg/lprcg.

The novel mutant gene, lprcg, is allelic with lpr, but complements the gld gene in induction of lymphoproliferation. Mice with this autosomal recessive mutation, CBA/KlJms-lprcg/lprcg (CBA-lprcg), served in this study to analyze the abnormalities of bone marrow (BM) stem cells responsible for autoantibody production and lymphoproliferation by BM transfer experiments. Transferred CBA-lprcg BM cells might have differentiated into so-called double-negative, anomalous lymphoid cells and caused production of autoantibodies such as anti-DNA antibodies in the environment of normal CBA/KlJms-(+)/+ (CBA-(+)) mice. Macroscopic graft-vs.-host-like disease as reported in lpr----non-lpr BM transfer was not observed in these recipients. In this BM chimera, however, lymphoproliferation did not ensue and the host's lymph nodes became atrophic. The lymphoproliferation required the coexistence of lprcg BM cells and lprcg lymph nodes in CBA-(+) mice. The results indicate that the functions of the lprcg gene are expressed at both BM and lymph node levels. Thus, this mutant strain of mice should provide an excellent model for analyzing aberrant lymphocyte differentiation from the BM cells leading to autoimmunity and lymphoproliferative disorder.

Animals↗
PubMed1991

Long-term proliferating early pre B cell lines and clones with the potential to develop to surface Ig-positive, mitogen reactive B cells in vitro and in vivo.

Cell lines and clones were established from PB76-positive mouse fetal liver at day 13 and 14 of gestation, which proliferated with division times of a day in serum-substituted cultures under the stimulatory influence of adherent stromal cells and the cytokine IL-7 for periods longer than half a year. These lines expressed varying levels of the B lymphocyte lineage related markers PB76, B220, BP-1, VpreB and lambda 5, but no surface Ig or MHC class II molecules. All clones expressed PB76, VpreB and lambda 5 in a high percentage of cells, while B220 and/or BP-1 expression was low or undetectable in some. A cell line, and several clones established from it, all had kappa and lambda light chain genes in germ-line configuration. Either one or both of their H-chain-gene containing chromosomes carried a DH to JH. These pre B cell lines and clones could be induced to VH to DH and VL to JL rearrangements. This resulted in the development of varying percentages of sIg-positive surface, MHC class II negative, LPS-reactive B cells within 2-3 days, in the absence of contacts with stromal cells and/or IL-7. When injected into SCID mice, the cultured pre B cells populated the spleen of these mice to 5% with surface Ig-, MHC class II-positive LPS-reactive cells for greater than 25 weeks. The long-term in vitro proliferative capacity of these DH-JH rearranged pre B cell clones makes them major candidates for committed stem cells of the B lineage.

Animals↗
PubMed1991

In-vivo processing of the initiator methionine from recombinant methionyl human interleukin-6 synthesized in Escherichia coli overproducing aminopeptidase-P.

Human interleukin 6 (hIL-6) overproduced in Escherichia coli HB101 was found to partially retain the initiator methionine (Met) residue (Met-hIL-6). In order to remove the residual N-terminal Met in vivo, an attempt was made to express hIL-6 in aminopeptidase-P (Ap-P)-hyperproducing strains, since the N-terminus Met-Pro- structure of nascent recombinant hIL-6 has been shown to be a favoured substrate of the enzyme in vitro. Using a mutant with duplicated Ap-P genes (pepP) on a chromosome or some recombinant strains overproducing Ap-P, we have succeeded in removing the initiator Met from Met-hIL-6 in vivo. The content of the mature product without the initiator Met in the pepP recombinant strains could be increased to approximately 99% from 85%.

Amino Acid Sequence↗
PubMed1991

A case of prominent hepatic cholestasis developing to hepatic failure in lambda-AL amyloidosis.

We report a case of lambda-AL amyloidosis which manifested prominent hepatic cholestasis. The patient was a 71-year-old Japanese male who was admitted to our hospital because of abdominal distension and jaundice. Laboratory examination revealed a marked deterioration of liver function with cholestasis. Gastric biopsy revealed amyloid deposition. Under a diagnosis of primary amyloidosis he was treated with corticosteroid and dimethylsulfoxide. However, jaundice progressed, renal function deteriorated rapidly, and he died two weeks after admission. Autopsy revealed a profound deposition of lambda-AL amyloid not only in the liver but also in the kidneys, spleen, lungs, heart and intestine.

Aged↗
PubMed1991

A monoclonal antibody to scopolamine and its use for competitive enzyme-linked immunosorbent assay.

A hybridoma clone producing a monoclonal antibody (SC78.H81) against scopolamine was established. The monoclonal antibody was an IgG1 (k) antibody with high affinity (1.6 x 10(9) M-1 for methylscopolamine). The monoclonal antibody was cross-reactive with methylscopolamine and butylscopolamine, and showed weak cross-reactivity with 6 beta- and 7 beta-hydroxyhyoscyamine. The cross-reaction with L-hyoscyamine, atropine, scopine and DL-tropic acid was very weak. A competitive enzyme-linked immunosorbent assay using SC78.H81 was established to quantify scopolamine. The sensitivity of the assay allowed detection of 20 pg assay-1 (0.2 ng ml-1) of scopolamine. The assay was applied to the estimation of scopolamine content in hairy root cultures of a Duboisia hybrid.

Antibodies, Monoclonal↗
PubMed1991

Responses of upper airway muscles to gastrocnemius muscle contraction in dogs.

We studied electromyographic (EMG) responses of the alae nasi (AN) and the posterior cricoarytenoid (PCA) muscles, which act as upper airway dilators, during contraction of gastrocnemius muscle in six chest-intact anesthetized dogs with spontaneous breathing and in four thoracotomized, phrenicotomized and mechanically ventilated dogs with right thoracic and left cervical vagotomy. Muscle contraction was phasically induced by electrical stimulation of the intact gastrocnemius nerve or the distal cut end of this nerve for 20-30 sec. Stimulation intensity was determined as twice the motor threshold in each dog. In chest-intact animals, phasic contraction induced by intact nerve stimulation produced initial rapid increases in upper airway muscle activity, but stimulation of the distal cut end of the nerve did not show the rapid increase in upper airway muscle activity. Furthermore, stimulation of the proximal cut end did not produce any transient response with the stimulation intensity used in this study. In chest-open and vagotomized animals with artificial ventilation, responses of the upper airway muscles to contraction during the intact nerve stimulation were observed. These results suggest that the contraction of the gastrocnemius muscle activates upper airway dilating muscles via reflex mechanisms.

Afferent Pathways↗