Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 289 records · Page 16Linked to original sources

PubMed1999

Laryngeal mask airway insertion using propofol without muscle relaxants: a comparative study of pretreatment with midazolam or fentanyl.

We determined the effects of pretreatment with midazolam or fentanyl on the ease of laryngeal mask airway insertion using propofol without a muscle relaxant. One hundred and eighty ASA class I or II patients were randomly allocated to one of three groups, 60 patients per group, to receive either placebo (Group C), midazolam 0.05 mg kg-1 (Group M) or fentanyl 2 micrograms kg-1 (Group F), respectively. Following intravenous administration of these drugs, Group C received propofol 2.5 (Group C-2.5) or 3.0 mg kg-1 (Group C-3.0). Group M and Group F received propofol 2.0 or 2.5 mg kg-1 (Group M-2.0, M-2.5, F-2.0 and F-2.5, respectively). There was a smaller incidence of severe head and limb movements on LMA insertion in Group M-2.5, Group F-2.0 and Group F-2.5 than in Group C-2.5. Airway obstruction and inadequate jaw relaxation, which were occasionally recognized in Group C and Group F patients, were not observed in Group M-2.5. Overall the ease of LMA insertion was significantly better in Group M-2.0, Group M-2.5 and Group F-2.5 than in Group C-2.5, however, the blood pressure in Group F after LMA insertion was significantly lower than in Group M. We conclude that pretreatment with midazolam 0.05 mg combined with propofol 2.5 mg kg-1 provides safe and satisfactory conditions for LMA insertion.

Adult↗

PubMed1999

Critical role of the membrane-proximal, proline-rich motif of the interleukin-2 receptor gammac chain in the Jak3-independent signal transduction.

BACKGROUND: The interleukin-2 receptor (IL-2R) consists of three subunits, the IL-2Ralpha, IL-2Rbetac, and IL-2Rgammac chains. The essential role of the IL-2Rgammac cytoplasmic domain, consisting of 86 amino acids, in signal transmission has been well documented. Particularly, the carboxyl ter-minal region containing 48 amino acids. is essential for the association with and activation of the Jak3 protein tyrosine kinase. On the other hand, little is known about the role of the rest of the IL-2Rgammac cytoplasmic region consisting of the membrane-proximal 38 amino acids. RESULTS: We show that a truncated mutant form of IL-2Rgammac which lacks the membrane-distal 48 amino acids is still capable of inducing the activation of Jak1 and Stat3/Stat5 in the absence of Jak3 activation. This membrane-proximal region can also mediate the IL-2-induced tyrosine phosphorylation of the p85 subunit of phosphatidylinositol-3-kinase (PI3K). Furthermore, these signalling events are completely abrogated when mutations are introduced into the proline-rich motif in this region. CONCLUSIONS: In this study, we identified a Jak3-independent signalling pathway(s) from the membrane-proximal region of IL-2Rgammac. Our results indicate that the proline-rich motif in this region plays a critical role in this signalling pathway(s). The present study may provide further insight into the mechanism of cellular responses mediated by IL-2 and other cytokines which utilize the IL-2Rgammac for their signal transmission.

Amino Acid Sequence↗

PubMed1999

Multicenter study on the effects of day care therapy on schizophrenia: a comparison of day care patients with outpatients.

The effects of day care therapy for a period of 6 months upon patients with schizophrenia were studied through comparison with schizophrenia outpatients at four facilities in Japan. The clinical features of the 31 day care patients and 30 outpatients were evaluated by the hospital staff using the Positive and Negative Syndrome Scale (PANSS) and Global Assessment Scale (GAS), and by the patients' close relatives using the Katz Adjustment Scale (KAS) before and after 6 months of treatment. Day care patients showed a significant decrease in the general pathological score of PANSS and GAS, but outpatients did not show any comparable improvement. As for KAS scores, similar improvement was observed for both the day care patients and outpatients After 6 months, 43% of the day care patients improved on the post-/pre- PANSS total scores ratio, as against only 13% of the outpatients. In addition, 13% of the outpatients were readmitted due to an exacerbation of their symptoms, whereas all day care patients were able to remain at home for 6 months. This study clearly demonstrated that day care therapy for patients with schizophrenia was more effective than the usual outpatients treatment setting. Further therapeutic efforts (e.g. psycho-education) in day care therapy are needed in order to improve family member's evaluation of the patient.

Adult↗

PubMed1999

Doc2alpha is an activity-dependent modulator of excitatory synaptic transmission.

Doc2alpha is a synaptic vesicle-associated Ca2 + -binding protein. To study the role of Doc2alpha in synaptic transmission and modulation, we generated homozygous null Doc2alpha mutant mice. In the CA1 region of hippocampal slices in the mutant mice, excitatory synaptic responses evoked with prolonged 5 Hz stimulation showed a significantly larger frequency facilitation followed by a steeper depression than those in wild-type mice, whereas there was no difference in synaptic transmission at lower frequencies or in paired-pulse facilitation. These results suggest that Doc2alpha regulates synaptic transmission when high Ca2 + concentrations in the presynaptic terminal are sustained. Furthermore, the mutant mice showed impairment in long-term potentiation and passive avoidance task. Thus, Doc2alpha may regulate transmitter release during repetitive synaptic activation, thereby contributing to memory formation.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1999

Positive association between an estrogen receptor gene polymorphism and Parkinson's disease with dementia.

Parkinson's disease (PD) is a common cause of dementia in the elderly. Dementia in Alzheimer's disease (AD) and PD share common biologic and clinical features. The estrogen receptor (ER) gene is one of the susceptibility genes for AD. In order to test the hypothesis that the overlap between AD and PD may have a genetic basis, we determined ER gene polymorphisms in 13 PD patients with dementia (PDD) (age +/- SD; 71.9 +/- 5.5 years), 71 PD patients without dementia (PDND) (68.4 +/- 7.5 years), 86 AD patients (76.8 +/- 8.0 years) and 51 control subjects (CTL) (74.9 +/- 6.9 years). ER genotypes were classified as a P or p allele on the basis of a Pvu II-RFLP, and X and x on the basis of a Xba I-RFLP. The frequency of the P allele in the PDD group as well as the AD group was higher than that in CTL. There was no significant difference in the distribution of the P allele between CTL and PDND. There were no significant differences in the distribution of the X allele among the PDD, PDND and CTL groups, whereas a higher incidence was found in AD. We conclude that the ER gene may be a common susceptibility gene for dementia in PD as well as AD.

Aged↗

PubMed1999

Antiviral activities against HSV-1, HCMV, and HIV-1 of rhamnan sulfate from Monostroma latissimum.

Rhamnan sulfate (RS), a natural sulfated polysaccharide isolated from Monostroma latissimum, showed potent inhibitory effects on the virus replication of herpes simplex virus type 1 (HSV-1), human cytomegalovirus (HCMV), and human immunodeficiency virus type 1 (HIV-1) in vitro. The antiviral action of RS was not only due to the inhibition of virus adsorption, but also might involve the later steps of viral replication in host cells on the basis of the results of time-of-addition experiments. Furthermore, RS and 3'-azido-3'-deoxythymidine (AZT) were synergistic in their anti-HIV-1 activities. These data indicate that RS is a potent antiviral substance against HSV-1, HCMV, and HIV-1.

Animals↗

PubMed1999

Misery perfusion caused by cerebral hypothermia improved by vasopressor administration.

Therapeutic cerebral hypothermia is widely used for the treatment of severe head injury and cerebral ischemia. The effects of cerebral hypothermia on the cerebral blood flow (CBF) and metabolism, and cerebral vasculature in the normal brain were investigated. Thirty-four adult cats were divided into four groups. CBF was monitored by hydrogen clearance. Arteriovenous oxygen difference (AVDO2) and cerebral venous oxygen saturation (ScvO2) were measured in blood samples from the superior sagittal sinus. The cerebral metabolic rate of oxygen (CMRO2) and cerebral vascular resistance (CVR) were calculated. The cerebral blood volume (CBV) was measured using technetium-99m-labeled human serum albumin in 12 cats. Deep cerebral temperature was cooled from 37 degrees C to 25 degrees C using a water-circulating blanket. In the hypothermia group (Group A: n = 10), CBF (51.2 +/- 8.3 ml 100 g-1 min-1 at 37 degrees C) decreased with lower brain temperature (6.1 +/- 2.7 at 25 degrees C). CMRO2 (2.24 +/- 0.75 ml 100 g-1 min-1 at 37 degrees C) was also decreased (0.52 +/- 0.20 at 25 degrees C). AVDO2 (4.3 +/- 1.0 ml 100 g-1 min-1 at 37 degrees C) increased significantly at 31 degrees C (6.6 +/- 1.8; p < 0.05) and ScvO2 (67.8 +/- 7.9% at 37 degrees C) decreased significantly at 29 degrees C (53.7 +/- 9.7; p < 0.05). CBV (5.3 +/- 1.2% at 37 degrees C) decreased significantly at 29 degrees C (3.7 +/- 1.0; p < 0.05) and CVR (3.2 +/- 0.7 mmHg ml-1 100 g-1 min-1 at 37 degrees C) increased significantly at 29 degrees C (13.8 +/- 5.2; p < 0.01). The combined effect of hypothermia with vasopressor (noradrenalin) (Group B: n = 6) or barbiturate (thiopental) administration (Group C: n = 6) on the cerebral metabolic parameters were also examined. Hypothermia with noradrenalin administration significantly improved the ischemic parameters (AVDO2 was 4.7 +/- 1.4 ml 100 g-1 min-1 at 31 degrees C and ScvO2 was 72.2 +/- 6.4% at 29 degrees C). However, hypothermia with barbiturate administration did not improve these metabolic parameters. These results suggest that hypothermia may cause vasoconstriction and misery perfusion in the brain. This potential risk of relative ischemia can be avoided by combination with vasopressor administration.

Analysis of Variance↗

PubMed1999

Co-expression of integrin-associated protein (IAP/CD47) and its ligand thrombospondin-1 on human granulosa and large luteal cells.

In the present study, we have raised a monoclonal antibody (mAb) designated OG-4 against human granulosa cells (GC). By immunohistochemistry, the expression of OG-4 antigen was observed on human GC and large luteal cells, but not on thecal and small luteal cells. A complementary DNA (cDNA) clone encoding OG-4 antigen was screened and isolated by a panning method using OG-4 mAb from a human corpus luteum (CL) cDNA library that was expressed transiently in COS-7 cells. Nucleotide sequencing revealed that OG-4 antigen was identical to integrin-associated protein (IAP)/CD47 antigen. Subsequent reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the isoform 2 mRNA of IAP is predominantly expressed in human GC and CL. The expression of thrombospondin-1 (TSP-1), which is a ligand for IAP, was also observed in human GC by immunocytochemistry and RT-PCR. Co-expression of IAP and TSP-1 on human GC may suggest that TSP-1 has a physiological role in GC function possibly via IAP in an autocrine fashion.

Adult↗

PubMed1999

CD9 is expressed in extravillous trophoblasts in association with integrin alpha3 and integrin alpha5.

The CD9 molecule is a 24-27 kDa cell surface glycoprotein, which may be related to Schwann cell migration and adhesion. In this study, we examined the expression of CD9 in human extravillous trophoblasts, which invade into the endometrium during implantation and placentation. CD9 was detected immunohistochemically on the extravillous trophoblasts in the cell columns of first trimester placentae, but not on villous trophoblasts. In the second and third trimester, CD9 was highly expressed on the extravillous trophoblasts in the basal plate of placentae, and in the chorion laeve in the fetal membrane of term placentae. The molecular mass of CD9 in the chorion laeve was shown to be 27 kDa by Western blotting. The mRNA of CD9 was also detected in the chorion laeve by reverse transcription-polymerase chain reaction (RT-PCR). Proteins were purified from chorion laeve by affinity chromatography with anti-integrin alpha3 and alpha5 monoclonal antibodies and Western blotting, revealed that CD9 was associated with both integrins. These findings indicate that CD9 is a differentiation-related molecule present in the extravillous trophoblasts. Since it is associated with integrin alpha5 which has been proposed to regulate trophoblast invasion, CD9 may be implicated in trophoblast invasion at the feto-maternal interface.

Antigens, CD↗

PubMed1999

CD9 is involved in invasion of human trophoblast-like choriocarcinoma cell line, BeWo cells.

The CD9 molecule is expressed on human extravillous trophoblasts, which invade the endometrium during implantation and placentation. To elucidate the role of CD9 in trophoblastic function, we investigated the expression of CD9 protein and mRNA in BeWo cells, a human trophoblast-like choriocarcinoma cell line, using immunohistochemistry, Western blotting and reverse transcription-polymerase chain reaction (RT-PCR). When BeWo cells were cultured with anti-CD9 monoclonal antibodies (mAb), their invasion through the extracellular matrices was significantly enhanced in a dose-dependent manner. Cell proliferation and human chorionic gonadotrophin production were unaffected. On the other hand, culture in the presence of mAb against integrins alpha3, alpha5 and beta1, which partially block the interaction with the extracellular matrices, inhibited BeWo cell invasion. Anti-CD9 monoclonal antibody had a stimulatory effect on BeWo cell invasion in the presence of anti-integrin alpha3 antibody. In contrast, it had no effect in the presence of mAb against integrins alpha5 and beta1, which were also highly expressed on BeWo cells. These findings suggest that CD9 has a function connected with the invasive properties of BeWo cells, which is partially mediated by integrin alpha5beta1. This may relate to the involvement of CD9 in trophoblastic invasion.

Antibodies, Monoclonal↗

PubMed1999

CD9 is expressed on the cell surface of human granulosa cells and associated with integrin alpha6beta1.

The CD9 molecule is a 24-27 kDa cell surface glycoprotein which is reported to be involved in cell adhesion and migration. Recently, CD9 was shown to be associated with beta1-related integrins. We have previously found that integrin alpha6beta1 is expressed on human granulosa cells (GC) and regulates luteinization of GC in concert with its ligand laminin. In this study, we examined the expression of CD9 in human ovary and the relationship between CD9 and integrin alpha6beta1 in GC. By immunohistochemistry, CD9 was detected on GC in a small antral follicle of <1 mm in diameter. In growing follicles, CD9 was moderately expressed on both GC and theca interna cells (TI). The expression intensity of CD9 on GC increased in preovulatory follicles. In the early luteal phase, CD9 was expressed in both luteinizing GC and TI. The expression intensity on large luteal cells decreased in the mid-luteal phase. In the corpus luteum (CL) of pregnancy, CD9 continued to be expressed on large luteal cells, but not on small luteal cells. By flow cytometry, CD9 was detected on the cell surface in approximately 90% of the isolated GC from patients undergoing in vitro fertilization. The molecular weight of CD9 in the isolated GC was shown to be 26.5 kDa by Western blotting. CD9 mRNA was also detected in the isolated GC and CL by reverse transcription-polymerase chain reaction (RT-PCR). The proteins purified from GC by immunoaffinity chromatography using anti-integrin alpha6 monoclonal antibodies were shown by Western blotting to include CD9 as well as integrin beta1. These findings suggest that CD9 is a differentiation-related molecule of GC and TI and that it is associated with integrin alpha6beta1 on the cell surface of GC, suggesting that CD9 is implicated in the function of human GC in cooperation with integrin alpha6beta1.

Adult↗

PubMed1999

Human granulosa cells express integrin alpha2 and collagen type IV: possible involvement of collagen type IV in granulosa cell luteinization.

Previously, it has been shown that integrin alpha6beta1 expressed on human granulosa cells regulates luteinization in co-operation with its ligand, laminin. In this study, integrin alpha2 was immunohistochemically demonstrated to be expressed on granulosa and large luteal cells. It was also detected on luteinizing theca interna cells after ovulation. Immunoreactive collagen type IV, which is one of the ligands for integrin alpha2beta1, was detected around granulosa cells in the pre-ovulatory follicles and its expression was rapidly increased during ovulation. By flow cytometry, collagen type IV was detected on the cell surface of luteinizing granulosa cells isolated from pre-ovulatory follicles, confirming the physiological interaction between granulosa cells and collagen type IV. Collagen type IV in follicular fluid was positively related with progesterone concentration. In 4-day cultures of granulosa cells, collagen type IV in the media was significantly increased by human chorionic gonadotrophin (HCG). The progesterone production was significantly attenuated when granulosa cells were cultured on collagen type IV-coated dishes, suggesting that collagen type IV suppresses granulosa cell luteinization. These findings show that collagen type IV, a ligand for integrin alpha2beta1, is rapidly produced around luteinizing granulosa cells during ovulation, probably under the control of luteinizing hormone (LH) and suggest that collagen type IV is a new parameter and/or regulator of granulosa cell luteinization in the periovulatory phases.

Antigens, CD↗

PubMed1999

DNA binding affinity of pentapeptides selected from combinatorial library.

The combinatorial method has been applied to determine peptide ligands to the duplex DNA by using the solid-state pentapeptide library and the target-DNA conjugated magnetic beads. Seventy-one sequences were determined as ligands for AT duplex. Interestingly, hydrophobic amino acids such as Phe, Ile and Gly were most frequently determined. Relative binding affinity of the selected pentapeptides with the various DNA sequences was estimated by ethidium displacement assay in 10 mM SHE buffer. FQGII constituted of amino acids that were most frequently determined in the random screening showed highest binding affinity to the duplex DNA.

Amino Acid Sequence↗

PubMed1999

Novel DNA-binding ligands with sequence selectivity based on hydrophobic structure.

We have developed diamino-bistetrahydrofuran compounds (diamino-bisTHF) as new DNA binding molecules. Diamino-bisTHF (3:RR8) stabilized GC-rich duplex DNA with sequence specificity. DNA binding affinity increased as the alkyl chain was lengthened, indicating that the hydrophobic interaction is essential for DNA binding. It was also found that DNA binding affinity of the ligands depends on the stereochemistry of the amino group. In thermodynamic evaluation, diamino-bisTHF (3:RR8) showed a high affinity to the 12 bp duplex at a molar ratio of 1:1.

Base Sequence↗

PubMed1999

Efficient cross-linking to cytidine by functional nucleobases capable of in situ activation.

We have previously demonstrated that the ODNs with 2-amino-6-(2-phenylsulfoxyethyl)purine nucleoside derivative were capable of efficient interstrand cross-linking with cytidine selectively. In this new strategy, less reactive precursor was auto-activated within a duplex to generate 2-amino-6-vinylpurine derivative. However, it turned out that 2-amino-6-(2-phenylsulfinyl)-ethylpurine nucleoside was not applicable as the precursor for the synthesis of DNA oligomers with G-rich sequences. In this report, 2-amino-6-(2-methylsulfinylethyl)purine nucleoside has been proven to be more suitable as a precursor for DNA synthesis. In addition, the ODNs incorporating either 2-amino-6-(2-phenylsulfoxy ethyl)purine or 2-amino-6-vinylpurine showed high reactivity toward the cytidine at the target site but quite less reactivity was observed for it at non-target site, demonstrating high site-selectivity.

Base Sequence↗

PubMed1999

Affinity separation of messenger RNA by thermo-responsive polymer carrying oligo(dT).

The conjugate between oligo(dT)16 and thermo-responsive polymer, poly(N-isopropylacrylamide), was prepared for isolation of poly(A)+ RNA from total RNA. The hybridization reaction between the conjugate and poly(A) (average length: 320 base) was equilibrated in 10 min, and all the poly(A) (16 nmol base for 24 nmol base of conjugate) was precipitated when raising the solution temperature to 35 degrees C. The precipitate was dissolved in water, and poly(A) was dissociated from the conjugate by heating to 65 degrees C. This separation system was successfully applied to the isolation of poly(A)+ RNA from total RNA.

Acrylic Resins↗

PubMed1999

The role of serum imbibition for skin grafts.

Numerous studies of grafted skin suggest that full-thickness skin grafts are nourished by exudate from the recipient bed called a serum imbibition. However, whether serum imbibition by itself is sufficient for nourishment of skin grafts has not been shown definitely and directly. To clarify the role of serum imbibition, we performed a comparative study between 20 skin grafts and 20 musculocutaneous flaps. The nourishment of the cell in the skin graft is by serum imbibition. That in musculocutaneous flaps is mainly derived from blood supply. We evaluated the nourishment by means of the unique characteristics of the cell cycle. Once cells are put into a synthetic phase, they cannot reverse or stop the progress of the cell cycle. To take advantage of this characteristic of the cell cycle, prewounding methods (40 flaps were lifted once and put back to the original sites prior to the evaluation) were intended for the cells in pre-elevated skin to turn into a proliferating phase. Cells were examined by antibody against proliferating cell nuclear antigen immunohistologically, to determine whether they had turned into the proliferating phase or not. After 3 days, all flaps were reelevated; half (20 flaps) had their muscle layer and the neurovascular bundle removed to make a full-thickness skin graft. The rest (20 flaps) were only lifted. They were sutured back to the original sites. Ten skin grafts and musculocutaneous flaps each were harvested at 3 hours (1st day) and at 11 days (11th day) after the second operation. Bromodeoxyuridine, which is a thymidine analog and is taken into the cells in the synthetic phase, was introduced intraperitoneally 2 hours before the harvest. All flaps and grafts were evaluated histologically and immunohistologically. Proliferating cell nuclear antigen analysis showed that the prewounding method induced the cells of skin grafts and musculocutaneous flaps to proliferate before the implantation. Regarding the bromodeoxyuridine uptake, no significant differences could be seen between skin grafts and musculocutaneous flaps irrespective of their different nourishment. No structural changes, such as degenerative or necrotic, could be seen at the hair follicle and other glands even at the 11th day. Almost all of the layers of skin grafts survived as long as they were checked by light microscopy (hematoxylin and eosin stain). No differences could be seen between musculocutaneous flaps and skin grafts or between the 1st and 11th days in this study. We concluded that serum imbibition is sufficient for nourishment of skin grafts, just as blood supply is sufficient for nourishment of musculocutaneous flaps.

Animals↗

PubMed1999

A case of generalized morphea with a high titer of anti-Borrelia burgdorferi antibodies.

A 69-year-old male had noticed pruritus on the back for the previous 3-4 years and cutaneous sclerosis with swelling of the dorsum of the neck had developed in the last one and a half years. However, he had never complained of Raynaud's phenomenon of the fingers, dry mouth, or dry eyes. At this first visit to our hospital, he complained of erythematous cutaneous sclerosis with swelling of the dorsum of the neck. Histopathological findings biopsied from the neck showed epidermal hyperplasia with elongation of rete ridges and homogeneous and fibromatous changes of the dermis with dense perivascular cell infiltration consisting of mononuclear cells or lymphocytes with several nests of incontinentia pigmenti. However, there were no sclerotic changes in blood vessels in the upper dermis biopsied from the forearm skin, although slightly homogeneous and fibromatous changes of the dermis were seen. In the clinical course, the cutaneous sclerotic change enlarged to extend to the bottom of the cheek, forearm, and lower legs. These clinical features and histopathological findings led to the diagnosis of generalized morphea. Hematologic examination showed positive anti-Borrelia burgdorferi IgM antibodies, although there were no positive anti-Borrelia burgdorferi IgG antibodies. These results revealed that there can be a close association of localized scleroderma with Borrelia burgdorferi and that generalized morphea may also represent a Borrelia infection.

Aged↗