Search PubMed⌕ Search

Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 631 records · Page 35Linked to original sources
PubMed1993

Clinical characteristics and hearing recovery in perilymphatic fistulas of different etiologies.

Clinical features and hearing recovery were compared between three types of perilymphatic fistula groups; surgically confirmed (PLF-conf, n = 16), suspected (PLF-susp, n = 24) and traumatic (trauma-PLF, n = 11). Initial average hearing level was best in the PLF-susp group (50.9 dBHL), followed by the trauma-PLF (55.7 dBHL) and PLF-conf (59.7 dBHL) groups, though the difference was not significant (ANOVA, p > 0.05). Of 51 patients, 27 cases were operated on and fistula was confirmed in 19 ears (70.4%). Conservative treatment, including bed rest and medication, was given to all patients. After the treatment, meaningful hearing recovery was obtained only at 1 kHz in the PLF-conf group (paired t-test, p < 0.05). However, significant recovery was seen at all frequency ranges (0.125-8 kHz) in the PLF-susp group (average, 16.8 dB; p < 0.01), while hearing improvement was intermediate for the trauma-PLF group. The initial hearing level and the period until the start of treatment strongly correlated with the final hearing level. Although 27 patients (47%) complained of dizziness, the prognosis for vertigo is excellent as noted by other authors. It was concluded that if conservative treatment is started early for PLF patients with mild hearing loss, hearing recovery can be ensured.

Adult↗
PubMed1993

beta-Alanine and taurine microinjected into the rat caudal ventrolateral medulla increase blood pressure.

Unilateral microinjections of GABA, glycine, beta-alanine and taurine into the caudal ventrolateral medulla (CVLM) of the rat, led to an increase in blood pressure and heart rate. The responses to glycine, beta-alanine and taurine but not to GABA could be blocked by strychnine. The responses to taurine and beta-alanine but not to GABA and glycine could be blocked by 6-aminomethyl-3-methyl-4H-1,2,4-benzothiadiazine-1,1-dioxide (TAG), an antagonist of taurine. The taurine antagonist alone injected bilaterally into the CVLM produced a decrease in blood pressure. From CVLM areas microperfused with Krebs solution, spontaneous release of GABA, glycine, beta-alanine and taurine was detected and high K+ stimulation caused a calcium-dependent release of GABA, beta-alanine and taurine. These results suggest that beta-alanine and taurine as well as GABA may be involved in modulation of the cardiovascular control within the CVLM.

Animals↗
PubMed1993

[Renal metastasis from osteogenic sarcoma: report of a case].

Renal metastases of osteogenic sarcoma are unusual clinical occurrence and cases of osteogenic sarcoma treated by nephrectomy for renal metastases have been rarely reported. We report a 19-year-old male who was successfully treated by left nephrectomy for a metastatic tumor of osteogenic sarcoma from the right femur. In 1989 above-knee amputation was performed and the initial relapse with right pulmonary metastasis was treated by right upper lobectomy in 1991. In February 1992 he developed left renal and left pulmonary metastasis, hence left nephrectomy and left upper lobectomy were performed. Metastases of osteogenic sarcoma to the organs other than the lung and bone will increase because of the improvement of diagnostic modalities. Our study suggests that a bone scan is useful for routine follow-up of patients with osteogenic sarcoma and that resection of the metastatic lesion can improve these patients' quality of life.

Adult↗
PubMed1993

Different responses of human marrow and circulating erythroid progenitors to stem cell factor, interleukin-3 and granulocyte/macrophage colony-stimulating factor.

The effects of recombinant human stem cell factor (SCF/c-kit ligand), interleukin-3 (IL-3) and granulocyte/macrophage colony-stimulating factor (GM-CSF) on erythroid colony formation by non-phagocytic mononuclear cells (MNC) and CD34+ cells derived from normal human bone marrow (BM), peripheral blood (PB) and umbilical cord blood (CB) were studied using a methylcellulose culture containing recombinant human erythropoietin (Epo). BM-MNC generated the largest number of total erythroid colonies consisting of erythroid bursts and erythroid mixed colonies (E-Mix) in the presence of SCF, whereas PB-MNC produced the largest number with IL-3. No additive effect between SCF and IL-3 was observed in the erythroid colony formation by BM- or PB-MNC. These observations were reproducible in cultures with several independent samples and purified CD34+ cells, suggesting that in normal human adults the erythroid progenitors supported by SCF alone mainly reside in the BM but those supported by IL-3 alone are mainly circulating. IL-3 was the most potent promoter of the total erythroid colony formation by CB-MNC, but it had no cooperation with SCF. In contrast, SCF supported large numbers of E-Mix and showed significant cooperative activity with IL-3 in E-Mix formation. These findings were also confirmed using independent specimens and CD34+ cells. Outstanding E-Mix formation by the CB cells indicated that newborn infants contain significantly more immature circulating erythroid progenitors than adults. These observations will stimulate interest in the role of the c-kit-SCF system as an adhesion molecule in the ontogenetic development of hemopoiesis.

Adult↗
PubMed1993

[Leukocyte activity and occurrence of tissue injury by G-CSF].

G-CSF (granulocyte-colony stimulating factor) is one of the cytokines which increase and activate neutrophils. These effects have been confirmed by a lot of clinical studies. Although only few side effects have been reported so far, we saw a patient with hypertension, facial edema, and severe headache after G-CSF administration. We have measured the sticking strength of leukocytes to the walls of narrow pores in modified Nuclepore filtration method of Kikuchi, in various clinical situations, and we have denoted the pore filtration time as the rheological activity of leukocytes (RAL). In this study, we tried to measure RALs of patients after G-CSF administration (60-100 micrograms) and to compare them with those of non-treated normal individuals. We also checked serum levels of granulocyte elastase in the patients. In the static state (in which neutrophils were not stimulated), RALs of the patients were 8.0 +/- 1.5sec. [N = 8], and those of the controls were 3.8 +/- 1.6sec. [N = 21] (p < 0.001). In the activated state (in which neutrophils were stimulated by formyl-methionyl-leucyl-phenylalanine), PALs of patients were quite high, i.e. those of the patients and controls were 592 +/- 322sec. and 69 +/- 62sec., respectively (p < 0.001). In all cases given G-CSF, the serum levels of granulocyte elastase were above the normal range. In view of our results, we it is possible that highly activated leukocytes would injure tissue and then induce organ failure and several symptoms, as in this study.

Adult↗
PubMed1993

Possible role of stem cell factor as a serum factor: monoclonal anti-c-kit antibody abrogates interleukin-6-dependent colony growth in serum-containing culture.

The monoclonal rat anti-c-kit antibody (ACK2), which abrogates colony growth supported by stem cell factor (SCF), significantly inhibited the interleukin-6 (IL-6)-dependent growth of hematopoietic progenitors derived from spleen cells of normal and 5-fluorouracil (5-FU)-treated mice and from bone marrow cells of normal mice in serum-containing culture. The numbers and types of colonies supported by IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), however, were not influenced by the addition of ACK2 to the cultures of the bone marrow cells from normal mice. In replating experiments with pooled blast cells, ACK2 caused a partial, but significant, inhibition of GM colony growth supported by a combination of IL-6 and fetal bovine serum (FBS), which suggests that FBS is one source of the SCF activity. Conversely, the addition of SCF or FBS with IL-6 to a serum-free culture had significant synergistic effects on the total number of colonies derived from post-5-FU spleen cells and from pooled blast cells. The dose response study showed that the ability of 30% FBS to interact with IL-6 on the colony growth by post-5-FU spleen cells was equivalent to that of approximately 5 ng/mL SCF. These findings suggest that c-kit plays an important role in the growth of hematopoietic progenitors responding to IL-6, and that SCF in the serum affects the development of hematopoietic progenitors in serum-containing cultures.

Animals↗
PubMed1993

Serological study of Japanese encephalitis in Nepal.

Antibodies against Japanese encephalitis virus (JEV) were examined in 356 serum samples from individuals visiting Tribhuvan University Teaching Hospital using neutralization test. A total of 13.2% (47/356) seropositivity was observed. Antibody positivity against both Nakayama-NIH and Beijing-1 strains was seen in 7.9% subjects. Infection by Nakayama-NIH strain alone was seen to be 4.2% while 1.1% of study populations were found to be infected only by Beijing-1 strain. High antibody titer was observed in the 20-40 years age-group and did not increase with age. Seropositivity was more common in zone-A (Tarai) area compared to zone-B (Hills) and zone-C (Mountains). Spectrum of antigenicity of JEV in zone-A as shown by neutralization test was identical to Indian isolates (strains). Difference in seropositivity was observed against Nakayama-NIH and Beijing-1 strain in zone-B and C indicating recent spread of JEV in these areas.

Adolescent↗
PubMed1993

[An autopsy case of the sinus of Valsalva aneurysm involved with tuberculous inflammation, leading to complete heart block].

A case is presented of unruptured aneurysm of the non coronary sinus of Valsalva, causing involvement of A-V node and right coronary artery compression. The patient was a 68 year-old woman with a complaint of general fatigue. Electrocardiogram showed complete A-V block. Computed tomography showed an aneurysm of the non coronary sinus of Valsalva. A temporary pacemaker was implanted, but the patient developed respiratory failure and heart failure and died. At autopsy, macroscopically disseminated tuberculosis was noted in both lungs and kidneys. Microscopically a tuberculous inflammatory lesion extending into the A-V node was found. We report this rare case with some consideration of the literature.

Aged↗
PubMed1993

Review on the relationship between nicotinic acetylcholine receptors and dopaminergic neurotransmission in the central nervous system--dopa is an endogenous neuroactive substance.

L-3,4-Dihydroxyphenylalanine (DOPA) is believed to be an inert precursor for dopamine (DA). Contrary, transmitter-like endogenous DOPA is released from in vitro and in vivo striata: DOPA is released by neuronal activities under physiological conditions from striata of conscious rats. Furthermore, exogenous nanomolar DOPA itself produces an in vitro presynaptic response to facilitate the catecholamine release. An in vivo postsynaptic depressor response is elicited by DOPA microinjected into the nucleus tractus solitarii. These responses are antagonized by L-DOPA methyl ester, a competitive DOPA antagonist. In striata, DOPA is an endogenous potentiator for presynaptic beta-adrenoceptors to facilitate the DA release and also probably for postsynaptic D2-receptors to increase locomotor activities. Nicotine releases DA and transmitter-like DOPA in vitro and in vivo striata. Nicotine (0.1-1.0 mg/kg, sc) dose-dependently increases locomotor activities. This increase is stereoselective and mecamylamine (1.0 mg/kg, sc)-sensitive but not antagonized by L-DOPA methyl ester (200 micrograms, ivt). Then, a selective low ip dose of alpha-methyl-p-tyrosine (alpha-MPT) to inhibit the basal release of DOPA without decreasing the basal release of DA was explored in vivo striata: it was 3 mg/kg. Pretreatment with this dose did inhibit the nicotine-induced increases in locomotor activities. This result suggests that endogenously released DOPA is in part relevant to nicotine-induced behavior in rats.

Animals↗
PubMed1993

Early cancer of the gastric remnant with special reference to the importance of follow-up of gastrectomized patients.

Seven patients with early cancer of the gastric remnant (group 1) and nine with gastric remnant cancer that developed after surgery for early gastric cancer (group 2) were studied clinicopathologically. In group 1, the great majority of cases were classified as type I by gross type. Most lesions existed in the posterior wall of the remnant stomach. All lesions were differentiated carcinomas. In group 2, six of the nine early gastric tumors resected at the initial surgery were present in site A and three in site M. Gross tumours were of various types. Six patients underwent Billroth II resection and two underwent Billroth I resection. At second surgery (for gastric remnant cancer) four lesions were found to be located in the gastric stump or anastomosed region and five in the posterior wall of the stomach remnant. Histologically, the lesions included four undifferentiated carcinomas and five differentiated carcinomas. Of the nine lesions involving the gastric remnant, only two were early stage: the remaining seven were in an advanced stage. Prognosis was extremely poor in the group, many patients dying of carcinomatous peritonitis. In summary, most group 1 patients had a type I lesion in the remnant stomach. In group 2, more than half of the lesions were present in the gastric stump or anastomosed site and most were in an advanced stage. These observations suggest that it is very important to follow up patients operated on for early gastric cancer in order to detect malignant lesions, if any, in the remnant stomach before disease progresses to a stage at which radical resection is no longer possible. Follow-up will no doubt improve long-term results following surgery for early gastric cancer. We consider endoscopic examination and biopsy, especially of the gastric stump and anastomosed site, of great importance for gastrectomized patients.

Aged↗
PubMed1993

[A case of adrenal myelolipoma incidentally discovered on abdominal ultrasonography].

We report a case of adrenal myelolipoma occurring in a 58-year-old-woman. A tumor was incidentally detected in the right adrenal region by ultrasonography during admission to our hospital due to gastric ulcer. Ultrasonography revealed punctate calcification within the tumor. No endocrinologic abnormalities were demonstrated. CT revealed a nonhomogenous mass 5 cm in diameter that consisted of tissue with a fatty density and areas of calcifications. Retrograde femoral angiography demonstrated that the tumor was relatively hypervascular. Large blood vessels resembled sinusoids that were demonstrated by pooling of the contrast medium. Right adrenalectomy was performed. The histological diagnosis was adrenal myelolipoma.

Abdomen↗
PubMed1993

[Analysis of cell proliferation in endoscopically biopsied specimen of the stomal mucosa of the remnant stomach--with special reference to cell cycle and ODC activity].

An attempt was made to investigate the status of cell proliferation in the remnant stomach, using endoscopically biopsied specimens, with cell cycle analysis by flow cytometry (FCM) and ornithine decarboxylase (ODC) activity determination. Fifty-three partially gastrectomized patients (male 33, female 20) were examined. Their mean age was 60.5, and 22 underwent Billroth I (BI), and 30 Billroth II (B II) operation. The mean time elapsing from the initial operation was 4.0 years. Almost all specimens showed DNA diploidy by FCM. The S phase cell percentage was higher in the stomal area, especially in the B II group. Significantly higher ODC activity was recognized in the stomal mucosa especially in the B II group. A significant positive relationship was noted between postoperative duration and ODC activity in the B II group. These results suggest activated cell proliferation in the stomal area of the remnant stomach. Especially in the B II group, cell proliferation increased with time after initial operation. This activated cell proliferation may play some role in the carcinogenesis of the remnant stomach.

Biopsy↗
PubMed1992

Purification and characterization of a diptericin homologue from Sarcophaga peregrina (flesh fly).

A protein with a molecular mass of 8 kDa was found to be synthesized specifically when the fat-body from injured Sarcophaga peregrina larvae was cultured in vitro. This protein was purified from the haemolymph of the injured larvae to near-homogeneity. Partial amino acid sequencing revealed that this protein is a diptericin homologue. It showed bactericidal activity on growing, but not resting Escherichia coli cells. E. coli cells become elongated on treatment with this protein.

Amino Acid Sequence↗
PubMed1992

Stem cell factor enhances proliferation, but not maturation, of murine megakaryocytic progenitors in serum-free culture.

The effects of recombinant rat stem cell factor (SCF/c-kit ligand) on murine megakaryocytopoiesis were studied using partially purified bone marrow cells derived from normal and 5-fluorouracil (5-FU)-treated mice in a serum-free culture system. SCF alone did not support the formation of megakaryocyte (M) and granulocyte-macrophage-megakaryocyte (GMM) colonies. However, the addition of SCF to cultures containing interleukin-3 (IL-3) resulted in a significant increase in the number of M and GMM colonies formed by bone marrow cells from normal mice, whereas IL-6 augmented only M colony growth. The stimulatory effect of SCF was approximately three to four times as high as that of IL-6 on the primitive progenitors capable of megakaryocytic-lineage expression derived from 5-FU-treated mice. In addition, SCF, but not IL-6, significantly increased the number of constituent cells in the individual M colonies supported by IL-3. On the other hand, SCF did not exert any effect on the size and DNA content of megakaryocytes in IL-3-dependent M and GMM colonies, whereas IL-6 enhanced the maturation of megakaryocytes. These results suggest that SCF stimulates the proliferative process in megakaryocytic progenitors and that the main activity of IL-6 is the promotion of megakaryocyte maturation.

Animals↗
PubMed1992

Evidence for L-dopa systems responsible for cardiovascular control in the nucleus tractus solitarii of the rat.

Microinjections of L-DOPA (10-100 ng) into the medial area of the nucleus tractus solitarii (NTS) led to dose-dependent decreases in arterial blood pressure and heart rate in rats treated with i.p. 3-hydroxybenzylhydrazine, a central inhibitor of DOPA decarboxylase, or similarly with intraventricular 6-hydroxydopamine. D-DOPA, dopamine or noradrenaline (100 ng) produced no effect. L-DOPA methyl ester (1 microgram), a competitive antagonist for L-DOPA, microinjected into NTS, blocked the depressor and bradycardic responses to L-DOPA. High K+ (40 mM) released endogenous DOPA in a Ca(2+)-dependent manner from slices of the rat dorsomedial medulla including NTS. These results support the hypothesis that there exist systems of L-DOPA itself responsible for cardiovascular regulation in NTS of rats. This regulatory action of L-DOPA seems to be postsynaptic in nature.

Animals↗
PubMed1992

Stimulation of mouse connective tissue-type mast cells by hemopoietic stem cell factor, a ligand for the c-kit receptor.

The proliferative capacity of mouse connective tissue-type mast cells (CTMC) was analyzed by using a newly discovered c-kit ligand, termed stem cell factor (SCF). More than 90% of CTMC in the peritoneal cavity responded to recombinant rat SCF (rrSCF) and were able to give rise to pure mast cell colonies in methylcellulose culture. Serial observation (mapping) of growth of individual CTMC in culture containing rrSCF confirmed their striking proliferative ability. No serum but accessory cells (non-CTMC cells) in the peritoneal population were required for the clonal growth of CTMC induced by rrSCF in our methylcellulose culture of whole peritoneal cells. The rrSCF-induced mast cell colony formation from peritoneal CTMC was completely inhibited by the addition of anti-c-kit antibody, which can block the binding of SCF to c-kit, to the culture. When IL-3 was combined with rrSCF, mast cell colonies dramatically increased in size. Mapping studies revealed that the combination of the two factors augmented the proliferative rate of CTMC. Approximately 60% of the constituent cells of the mast cell colonies which were formed from peritoneal CTMC in the culture containing rrSCF alone were stained with berberine sulfate, which is a characteristic of CTMC. However, most mast cells which were induced by rrSCF+IL-3 from peritoneal CTMC contained berberine(-)-safranin(-)-Alcian blue(+) granules. Although IL-4 exhibited little synergism with rrSCF in the induction of CTMC proliferation, the addition of IL-4 to the culture containing rrSCF+IL-3 resulted in an increase in mast cells which retained CTMC characteristics.

Animals↗