Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 271 records · Page 15Linked to original sources

PubMed1999

Brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) levels in normal pregnancy and preeclampsia.

OBJECTIVE: Our purpose was to evaluate plasma levels of brain natriuretic peptide (pBNP) and cyclic guanosine monophosphate (pcGMP) in preeclamptic patients and controls. STUDY DESIGN: Blood samples were obtained from 35 patients with preeclampsia and from the same women during the subsequent puerperal period. The control group consisted of normotensive pregnant women, matched with the patients for age, gestational age, and parity. The concentrations of pBNP and pcGMP were determined by the RIA method. Statistical analysis was performed using the Mann-Whitney's U test. RESULTS: The pBNP level in the preeclampsia group was significantly increased, to 7-fold that of the control group. The pcGMP level was 50% higher in the preeclampsia group than in the control group, but this was not significant. Both the pBNP level and the pcGMP level in the puerperal period did not significantly differ between the patients and the controls. CONCLUSION: The pBNP concentrations increased in the preeclamptic women, and then these compensations were normalized in the puerperal period.

Adult↗

PubMed1999

Facilitated cement removal technique between splinted crowns.

A technique for facilitating cement removal between splinted crowns is described. The technique involves tying dental floss with the large-diameter yarn portion around the embrasure of the splinted crown before cementing, and pulling it through before the cement has reached a final set. This simple, quick technique achieves removal of cement without damage to the interproximal crown surface.

Cementation↗

PubMed1999

Regulation of the expression of serotonin N-acetyltransferase gene in Japanese quail (Coturnix japonica): I. Rhythmic pattern and effect of light.

Serotonin N-acetyltransferase [arylalkylamine N-acetyltransferase (AANAT); EC2.3.1.87] is the rate-limiting enzyme in melatonin synthesis, and its activity exhibits a diurnal rhythm similar to that of the melatonin content in the pineal gland and retina of Japanese quail. Studies were conducted to characterize the Japanese quail AANAT cDNA, and to evaluate the expression of AANAT mRNA in the pineal gland, the retina, and other peripheral tissues. The nucleic acid sequence of a 400 bp cDNA clone obtained by RT-PCR manifested 78 and 95% homology compared to the rat and chicken AANAT cDNA, respectively, while the deduced amino acid sequence homology was 82 and 99%, respectively. AANAT mRNA content in a single pineal gland or an aliquot of eye lysate was measured by a micro-lysate protection assay. The expression of AANAT mRNA in the pineal gland and the retina exhibited circadian rhythm with peak levels at night. AANAT mRNA was also detected in the testis, but did not display a rhythmic change over a 24 hr period. AANAT mRNA was not detected in other tissues studied. Darkness during the day did not increase the pineal AANAT mRNA levels. However, unexpected light-exposure for 2 hr just after lights-off blocked the increase in AANAT mRNA, and at midnight remarkably decreased AANAT mRNA by 50%.

Amino Acid Sequence↗

PubMed1999

Regulation of the expression of serotonin N-acetyltransferase gene in Japanese quail (Coturnix japonica): II. Effect of vitamin A deficiency.

Levels of serotonin N-acetyltransferase [arylalkylamine N-acetyltransferase (AANAT); EC2.3.1.87] mRNA, AANAT activity, and melatonin display a rhythmic pattern in both the pineal gland and the retina. It has been shown that vitamin A is required to maintain the rhythm of melatonin synthesis in the pineal gland of Japanese quail. To understand the mechanism underlying the direct relationship among these factors, we developed an assay system sensitive enough to determine AANAT mRNA, AANAT activity, and melatonin content from a single pineal gland of Japanese quail. Positive direct relationships were found among these three parameters. We next deprived Japanese quail of vitamin A by feeding them a vitamin A-free diet supplemented with retinoic acid, and examined the effects of vitamin A deficiency on the expression of AANAT mRNA in the pineal gland and the retina. Vitamin A deficiency reduced both the expression of AANAT mRNA and melatonin content in the pineal gland. Retinal AANAT mRNA rhythm disappeared in vitamin A-deficient quails. Moreover, the responsiveness of the pineal gland and the retina to light was reduced by vitamin A deficiency when compared with the control group.

Animals↗

PubMed1999

Identification of human herpesvirus 8-specific cytotoxic T-cell responses.

Human herpesvirus 8 (HHV-8) (or Kaposi's sarcoma-associated herpesvirus) is implicated in the etiopathogenesis of Kaposi's sarcoma (KS) and certain lymphoproliferations. The introduction of more effective therapies to treat human immunodeficiency virus infection has led to a decline in the incidence of KS and also in the resolution of KS in those already affected. This suggests that cellular immune responses including cytotoxic T lymphocytes (CTLs) could play a vital role in the control of HHV-8 infection and in KS pathogenesis. Here we elucidate HLA class I-restricted, HHV-8-specific cellular immune responses that could be important in the control of HHV-8 infection and subsequent tumor development. We show the presence of CTLs against HHV-8 latent (K12), lytic (K8.1), and highly variable (K1) proteins in infected individuals.

AIDS-Related Opportunistic Infections↗

PubMed1999

Thrombin receptor mediated signals induce expressions of interleukin 6 and granulocyte colony stimulating factor via NF-kappa B activation in synovial fibroblasts.

OBJECTIVE: To clarify the mechanism of thrombin receptor mediated signal transduction and the induction of cytokines by thrombin stimulation in rheumatoid synovial fibroblasts. METHODS: Cytokines were measured by enzyme linked immunosorbent assay (ELISA) in the supernatants of cultured rheumatoid synovial fibroblasts stimulated by thrombin. To assess the mechanism of thrombin receptor mediated signal transduction in the rheumatoid synovial fibroblasts, electrophoretic mobility gel shift assay (EMSA), immunoglobulin kappa-chloramphenicol acetyltransferase (CAT) assay, and immunostaining for NF-kappa B subunit molecule was performed. RESULTS: Thrombin stimulation activated the inducible transcription factor NF-kappa B, and then induced subsequent expressions of interleukin 6 (IL6) and granulocyte colony stimulating factor (G-CSF) in the cells. CONCLUSION: Thrombin receptor mediated signal transduction could induce the expressions of IL6 and G-CSF, and increase inflammatory events in the cavum articulare via NF-kappa B activation.

Arthritis, Rheumatoid↗

PubMed1999

Serum samples of patients with rheumatoid arthritis contain a specific autoantibody to "denatured" aldolase A in the osteoblast-like cell line, MG-63.

OBJECTIVE: To identify rheumatoid arthritis (RA) specific autoantibody and its antigen in the human osteoblast-like cell line, MG-63. METHODS: MG-63 cell extract was subjected to western blotting by using RA and normal serum samples as probes. The autoantigen was purified and its N-terminal sequence was determined by automated Edman degradation. The reactivity of denatured aldolase A was evaluated by immunoblotting. Screening by enzyme linked immunosorbent assay (ELISA) using the autoantibody was performed. RESULTS: 40 kDa protein was found only in the RA serum samples and it was identified as aldolase A. A polyclonal antibody for rabbit muscle aldolase A bound to the 40 kDa protein and reacted in preference with the denatured enzyme. Using ELISA for denatured rabbit aldolase A, the autoantibody was found in approximately 10% of RA patients, whereas it was not found in the other arthropathy and healthy adults. CONCLUSION: This 40 kDa anti-aldolase A autoantibody, which was identified only in serum samples of RA patients with severe bone erosion, could be related to a certain event that induces RA specific joint destructions.

Adult↗

PubMed1999

Expression of an inwardly rectifying K(+) channel, Kir4.1, in satellite cells of rat cochlear ganglia.

Satellite cells are glial cells wrapped around somata of sensory and autonomic ganglion neurons. Neither their functional roles nor electrical properties have been fully clarified so far. Using immunohistochemistry, we found that inwardly rectifying K(+) channel subunit Kir4.1 (also called Kir1.2 or K(AB)-2) was expressed prominently in the satellite cells of cochlear ganglia. The Kir4.1 immunoreactivity was localized specifically at the myelin sheaths of satellite cells wrapping the somata of the ganglion neurons. Developmental expression of Kir4.1 in satellite cells paralleled development of the action potential in the auditory nerve. These results suggest that this channel in satellite cells may be responsible for the regulation of K(+) extruded from the ganglion neurons during excitation.

Aging↗

PubMed1999

Biological roles of angiotensin II via its type 2 receptor during rat follicle atresia.

Type 1 angiotensin II (ANG II) receptors play crucial roles in the regulation of blood pressure and fluid osmolarity, whereas the physiological roles of type 2 ANG II receptors (AT2) remain unclear. Because AT2 is expressed in atretic follicles where granulosa cells undergo apoptosis, we examined the space and time relationship between AT2 expression and follicle atresia in vivo and the effect of AT2 on follicle-stimulating hormone (FSH) actions in vitro. Binding studies, autoradiography, and RT-PCR of AT2 revealed that the AT2 content in granulosa cells was time dependently increased at both protein and mRNA levels in equine chorionic gonadotropin-treated immature female rats. This increase paralleled the progression of atresia. ANG II suppressed FSH-caused prevention of DNA fragmentation, increases in luteinizing hormone receptor content, and estrogen production through AT2 in cultured granulosa cells. Moreover, FSH-induced stimulation of extracellular signal-regulated kinase activity, critical for cell survival, was inhibited by AT2 stimulation. These results suggest that AT2 mediates the progression of follicle atresia through granulosa cell apoptosis by inhibiting FSH actions.

Angiotensin II↗

PubMed1999

Chronological changes in incidences of polymorphic reticulosis in Korea and Japan.

Lethal midline granuloma (LMG) is a clinical term, which describes a group of diseases histologically comprising Wegener's granulomatosis, polymorphic reticulosis (PR), and malignant lymphoma of the ordinary type (ML). PR is a variant of ML, and is considered to be a type of NK/T cell lymphoma. Our previous study revealed the clustering of patients with PR in East Asia including China, Korea and Japan. However, the frequency rate of PR varied even among these countries, with that of Korea being approximately 5 times higher than that of Japan. In the present study, we examined the incidences of each type of LMG, especially PR, in Korea (Yonsei University) and Japan (59 university hospitals) over time. A total of 102 cases and 655 cases of LMG admitted to Yonsei University, Korea from 1977 to 1996 and 59 university hospitals in Japan between 1965 and 1996, respectively, were examined. The frequency rate of PR per 100,000 outpatients of ears, nose and throat (ENT) clinics in Korea decreased from 40 to 20 between the periods of 1977-1989 and 1990-1996. However, there were no significant changes in Japan during the period studied.

Adolescent↗

PubMed1999

Evidence for the involvement of platelet-derived growth factor in the angiotensin II-induced growth of rat vascular smooth muscle cells.

This study examines the possible involvement of endogenous platelet-derived growth factor (PDGF) in the angiotensin II-induced growth of rat aortic smooth muscle cells. In quiescent confluent cells, anti-PDGF-AB neutralizing antibody inhibited angiotensin II-induced DNA synthesis and protein synthesis. PDGF-AA, -AB, and -BB produced concentration-dependent increases in DNA synthesis and protein synthesis. Genistein did not inhibit PDGF-AB-induced [3H]thymidine incorporation and [3H]leucine incorporation. PDGF-AB stimulated mitogen-activated protein (MAP) kinases, and PDGF-induced MAP kinase activation was inhibited by genistein. Angiotensin II induced PDGF-A chain messenger RNA expression, and genistein inhibited angiotensin-induced PDGF gene expression. These findings suggest that endogenous PDGF is, at least in part, involved in angiotensin II-induced cell growth in rat vascular smooth muscle cells. It appears that genistein inhibits angiotensin II-induced DNA synthesis partly by inhibiting PDGF-A gene expression.

Angiotensin II↗

PubMed1999

[Development and assessment of the pharmaceutical management and guidance services for inpatients considering clinical value and economy].

We developed pharmaceutical management and guidance services for inpatients in a ward of circulatory medicine, considering clinical and economical standpoints. In these services, pharmacists deliver drugs prescribed for inpatients with individual drug information papers, explain to them about their drugs using information papers and give counsel. Since most of the patients were aged people, developing many kinds of diseases and taking many kinds of drugs, they had many problems such as lack of knowledge of the effects of drugs. First, we surveyed views of patients, physicians and nurses on these services. Consequently, all of them advised us that "pharmacists should explain to patients about the prescribed drugs using information papers." The patients preferred pharmacists as expositors of drugs to physicians or nurses. The physicians considered that "pharmacists have to attach importance to clinical information and package-inserts of drugs and explain to patients about drug information using pamphlet in response to the understanding of patients." The nurses wanted to cooperate with pharmacists in "improving medication compliance." On the basis of these views, we improved our services. Next, we made a survey of patients' knowledge about their drugs. We found that in the patients the level of knowledge concerning "ways," "effects" and "reasons" of taking drugs and that of "compliance" and "satisfaction in taking drugs" were improved through these services. The patients reentered in the hospital kept a high level. The ratio of patients taking drugs by themselves increased. Last, we also applied this method to wards of "blood and collagen diseases" and "pediatrics." The demand for these services increased smoothly. We compared these services based on our method with all other services by hospital pharmacists from the viewpoint of economy. We found that only our service method was beneficial.

Drug Therapy↗

PubMed1999

Differential diagnosis of gynaecological "stained glass" tumours on MRI.

Although multilocular cystic gynaecological masses in which the loculi show variable signal intensity on both T1 and T2 weighted images have been considered to be mucinous cystadenoma or adenocarcinoma, other gynaecological tumours can demonstrate this "stained glass" appearance. These include mature cystic teratoma, fibrothecoma, endometrioma, Brenner's tumour of the ovary and degenerated leiomyoma of the uterus, all of which may mimic mucinous tumours of the ovaries.

Diagnosis, Differential↗

PubMed1999

Diagnostic criteria for non-traumatic osteonecrosis of the femoral head. A multicentre study.

Six major and seven minor diagnostic criteria have been developed by the Japanese Investigation Committee for osteonecrosis of the femoral head (ONFH). We have carried out a multicentre study to clarify these. We studied prospectively 277 hips in 222 patients, from six hospitals, who had ONFH and other hip pathology and from whom histological material was available. We identified five criteria with high specificity: 1) collapse of the femoral head without narrowing of the joint space or acetabular abnormality on radiographs, including the crescent sign; 2) demarcating sclerosis in the femoral head without narrowing or acetabular abnormality; 3) a 'cold-in-hot' appearance on the bone scan; 4) a low-intensity band on T1-weighted images (band pattern); and 5) evidence of trabecular and marrow necrosis on histological examination. With any combination of two of these criteria, the sensitivity and specificity of the diagnosis were 91% and 99%, respectively.

Adolescent↗

PubMed1999

Direct bone induction in the subperiosteal space of rat calvaria with demineralized bone allografts.

In order to clarify the understanding of bone induction with crude bone morphogenetic protein (BMP)-containing allografts in subperiosteal conditions, chondrogenesis and osteogenesis were histologically evaluated following the implantation of the demineralized bone (DB) in the subperiosteal space of calvaria of 30 Wistar rats. On the forehead of the rat, DB particles were placed onto the denuded calvarial bone and covered by the skin-periosteum flap without any perforations of the marrow space of the calvaria. Sintered hydroxylapatite particles (HA) were also placed as a control. In the DB group, new bone formation on the surface of calvaria was achieved between 2 and 8 weeks after the operation. However, no chondrogenesis was seen throughout the experimental period. In the HA implantation group, fibrous tissue encapsulation of HA particles was generally seen. These results suggest that DB containing crude BMP might have the capacity for direct osteoblast induction from undifferentiated mesenchymal progenitor cells in vivo in specific situations, that is, in a subperiosteal space of uninjured rat calvaria.

Animals↗

PubMed1999

Dissociation of vascular tolerance and plasma norepinephrine adjustment during long-term nitrate therapy in human coronary arteries.

OBJECTIVE: We examined whether changes in plasma norepinephrine (NE) concentration contribute to the development of nitrate tolerance in human coronary arteries. METHODS: Patients with stable angina were randomized to receiving nitrate (isosorbide dinitrate: ISDN or nitroglycerin: TNG) infusion for 30 minutes (group A), 48 hours (group B), or 78 hours (group C). Coronary diameters were measured angiographically at baseline (CT), during maximum dilation by ISDN (N1), at the end of nitrate infusion (N2) and after additional ISDN (1 mg) injection (N3). RESULTS: In groups A and B, N1, N2, and N3 were greater than CT, and there was no significant difference between N1, N2, and N3 for each group. In group C, N1 and N3 were greater than CT, but there was no difference between CT and N2, in the development of nitrate tolerance. In group A, NE increased significantly during nitrate infusion (304+/-163 vs. 418+/-273 pg/ml). NE did not change in groups B and C. CONCLUSION: The change in NE concentration is not a primary contribution to the development of nitrate tolerance.

Aged↗

PubMed1999

[Labyrinthine fistulas in cholesteatoma].

The purpose of the present study was to investigate the clinical features of cases of cholesteatoma with labyrinthine fistulas, and in particular the pre and post-operative bone-conduction (BC). Cholestatoma patients with bone erosion or a defect found in the first stage operation were analyzed. The operations were conducted between 1992 and 1996. The patients were classified into four types, I, IIa, IIb, and III, according to Dornhoffer and Milewski's classification, which is based on different stages in the bone defect. A type I fistula is an erosion of the bony labyrinth with an intact endosteum. Type IIa is accompanied by an opened perilymphatic space with undisturbed perilymph while type IIb has a disturbed perilymph. A Type III fistula is an opened perilymphatic space with a disturbance of the underlying membranous labyrinth. Only 24 patients with type II and type III fistulas were included in this study. The location of the fistulas was the semicircular canals (SCCs) or/and the vestibula in 21 patients and in the cochlea in 3 patients. We examined the fistula by high-resolution computed tomography scan (CT scan) with 1 mm slice and 1 mm width axial-sections in 14 patients. A bone defect in the labyrinth was detected in 10 cases (71.5%) pre-operatively. Pre-operative BC was worse in the patients with cochlear fistulas than in those with fistulas located in SCCs or the vestibula. Within this latter group there were 13 type IIa (group IIa), patients and 8 type IIb or III (group IIb or III) patients. However, there was no difference in the pre-operative BC between these two sub-groups Tympanoplasty was conducted in all 24 patients. The postoperative BC of group IIa and group IIb or III were compared. Two of the 13 patients in group II a (15.4%) and 3 of 8 in group IIb or III (37.5%) had a deteriorated postoperative BC. Statistical analysis revealed that the postoperative BC was more inclined to become worse in patients with advanced stage IIb or III fistulas.

Adolescent↗

PubMed1999

[The prognostic value preoperative promontory testing in Japanese cochlear implant patients].

The prognostic value of preoperative promontory testing was evaluated in Japanese cochlear implant patients. Promontory testing consisted of measurement of electrical thresholds (T), uncomfortable level (UCL), dynamic range (DR), gap detection (GAP), and temporal difference limen (TDL). Patients' performances were measured at 3 months (n = 46) and 1 year (n = 20) postoperatively, using a standard Japanese audiologic test battery without lip-reading. This study included only postlingual deaf patients who received the Nucleus multichannel cochlear implant. Wide DRs at low frequencies (50,100,200 Hz) and good GAP detection (< 20 ms) emerged as excellent preoperative predictors of the 3-month postoperative performances (P < 0.05). In contrast, any measurements could not serve as a good predictor of the 1-year performances. These results suggest that the preoperative promontory testing provides useful information only for early postoperative performances but that it could not predict the final language performances.

Adolescent↗