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Biomedical subjects

K Deguchi

Publications and source records attributed to K Deguchi.

At least 55 records · Page 3Linked to original sources

Periventricular leukomalacia: relation to gestational age and axonal injury.

Eighty-five infants ranging from 22 to 41 weeks gestation were diagnosed as having periventricular leukomalacia (PVL) using traditional neuropathologic methods. The lesions were also studied by immunocytochemistry for beta-amyloid precursor protein (beta-APP), a glycoprotein that has been observed in PVL. Using this technique, the distribution of white matter tissue necrosis was defined as focal, widespread, and diffuse. The type of PVL correlated with the gestational age at birth. The youngest infants tended to demonstrate widespread necrosis, and the oldest infants exhibited more focal necrosis. beta-APP immunopositivity was present in the axons around the foci of white matter necrosis in 76% of the patients and in the neurons of the adjacent cortex in 66% of the patients. In age-matched control patients, there was no beta-APP reactivity in the cerebral white matter or the cortex. In most patients the distribution of beta-APP-positive axons proved to be a useful marker for demonstrating the type of PVL; however, the relationship of beta-APP to the pathogenesis of PVL requires further study.

Amyloid beta-Protein Precursor↗

Intra-operative optical method using intrinsic signals for localization of sensorimotor area in patients with brain tumor.

The purpose of this study is intra-operatively to localize the sensorimotor area by intrinsic optical method detecting the changes in regional cerebral blood flow (rCBF) and cortical temperature following neuronal activity during median nerve stimulation. In 18 patients with brain tumors located around the sensorimotor cortex, cortical recording of somatosensory evoked potentials (SEPs) was performed and localized changes in rCBF during median nerve stimulation were measured by a laser-Doppler flowmeter on the locations of SEPs and around the activation area obtained by functional magnetic resonance imaging (fMRI). In two patients, cortical thermomapping was also performed during median nerve stimulation. In fMRI study, the significant activation area of sensorimotor could be obtained in 17 of 18 patients. In cortical recording of SEPs, the polarity reversal of N20 and P20 was observed in 14 of the 18 patients. In 9 of the 14 patients in whom SEPs could be recorded, the localized changes in rCBF, corresponding to the stimulation, were detected in the N20 area. In 2 of the 4 patients in whom N20 could not be recorded successfully, the localized changes in rCBF could be detected. The increase in rCBF during the stimulation was 18.3% +/- 5.3% (mean +/- SD, n = 11). Thermomapping could demonstrate the localized area, where the increase in rCBF was also detected, by observation of the changes in cortical temperature during the stimulation. The intra-operative intrinsic optical method detecting rCBF and cortical temperature in combination with recording of SEPs may be considered useful for brain functional localization related to neurosurgical disorders.

Aged↗

Continuous haemodynamic monitoring in an unusual case of swallow induced syncope.

A 69 year old man is described with a 12 year history of intermittent syncope associated with ingesting solid food, mainly after having fasted. He was taking enalapril, propranolol, bendrofluazide (bendroflumethiazide), omeprazole, finasteride, and aspirin. Detailed investigations, including gastrointestinal evaluation, measurement of various gut hormones, and autonomic testing, indicated no abnormality. A liquid meal, performed before fasting, failed to elicit an episode. However, a solid meal after an overnight fast provoked near-syncope. Continuous non-invasive haemodynamic monitoring (with a Portapres II) indicated a short lived rise in blood pressure and heart rate, followed by severe hypotension, a fall in stroke volume and cardiac output, and then bradycardia. This favoured an initial increase in sympathetic activity, followed by vasodepression due to sympathetic withdrawal or activation of humoral vasodilatatory mechanisms, with bradycardia secondary to impaired cardiac filling. Withdrawal of enalapril abolished the episodes. The unusual nature of this case, in which haemodynamic recordings continuously were made during and after swallow syncope, induced soon after food ingestion, is discussed.

Aged↗

Recombinant human bone morphogenetic protein-2 stimulates osteoblastic differentiation in cells isolated from human periodontal ligament.

Periodontal ligament cells may play an important role in the successful regeneration of the periodontium. We investigated the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2), one of the most potent growth factors that stimulates osteoblast differentiation and bone formation, on cell growth and osteoblastic differentiation in human periodontal ligament cells (HPLC) isolated from four adult patients. rhBMP-2 induced no significant changes in cell growth in any of the HPLCs. rhBMP-2 at concentrations over 50 ng/mL significantly stimulated alkaline phosphatase (ALPase) activity and parathyroid hormone (PTH)-dependent 3', 5'-cyclic adenosine monophosphate accumulation, which are early markers of osteoblast differentiation, in the HPLCs. rhBMP-2 (500 ng/mL) also slightly enhanced the level of PTH/PTH-related peptide receptor mRNA expression in these cells. While interleukin-1 beta enhanced ALPase activity stimulated with rhBMP-2, tumor necrosis factor-alpha inhibited the rhBMP-2-stimulated activity. Interleukin-6 induced no significant changes in ALPase activity stimulated with rhBMP-2. Although HPLCs, whether treated with rhBMP-2 or not, could not produce measurable amounts of osteocalcin, which is a marker of more mature osteoblasts, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced osteocalcin mRNA expression and protein synthesis in these cells. rhBMP-2 inhibited 1,25(OH)2D3-induced osteocalcin synthesis in HPLCs at both the mRNA and protein levels. These results suggest that rhBMP-2 provides an anabolic effect on periodontal regeneration by stimulation of osteoblastic differentiation in human periodontal ligament cells, and that this stimulatory effect is differentially modulated by inflammatory cytokines during the course of periodontal regeneration.

Adolescent↗

Aberrations of the tissue factor pathway in patients positive for lupus anticoagulant.

To evaluate the relationship between the tissue factor (TF) pathway and lupus anticoagulant (LA), in the present study, we measured the plasma levels of TF antigen and TF pathway inhibitor (TFPI) antigen in patients positive for LA. Plasma TF and TFPI levels in LA-positive patients were significantly higher than levels in healthy volunteers (p < 0.01). In LA-positive patients, there were no significant differences in plasma TF and TFPI levels between patients with and without thrombosis. In patients with thrombosis, there was no significant difference in the plasma TF level between LA-positive and LA-negative patients; however, the plasma TFPI level in LA-positive patients was significantly lower than that in LA-negative patients (p < 0.01). We also examined the TF pathway in human umbilical venous endothelial cells (HUVEC) incubated with plasma of LA-positive patients, LA-negative patients, and healthy volunteers. TF activity was significantly higher (p < .05) in HUVECs incubated with the plasma of LA-positive patients than in cells incubated with the plasma of the other two groups (p < .01). However, there was no significant difference in TFPI antigen levels among the media of HUVECs incubated with the plasma of all groups. The viability of HUVEC incubated with the plasma of LA-positive patients with thromboses, LA-positive patients without thromboses, and LA-negative patients with thromboses were significantly lower than that of HUVECs incubated with the plasma of healthy volunteers (p < .01). These findings suggest that abnormalities of the TF pathway plays an important role in the mechanism of hypercoagulability in LA-positive patients. LA may affect vascular endothelial cells causing thrombogenesis.

Adult↗

Increased activated protein C: protein C inhibitor complex and decreased protein C inhibitor levels in patients with chronic renal failure on maintenance hemodialysis.

Hemostatic abnormalities were examined in 55 patients during maintenance hemodialysis (HD). Before HD, plasma protein C and protein S antigens were almost within the normal range, while plasma thrombin-antithrombin III complex (TAT III) and plasmin-plasmin inhibitor complex (PPIC) levels in HD patients were increased slightly, and plasminogen activator inhibitor 1 level was significantly increased, compared to that in normal volunteers. Plasma activated protein C (APC) and protein C inhibitor (PCI) complex and APC alpha 1 antitrypsin (alpha 1AT) complex were not detected in normal volunteers; however, plasma APC-PCI complex was increased in 36 of the patients and plasma APC-alpha 1AT complex was increased in 25 patients. Plasma PCI levels in these patients before HD were significantly decreased. Plasma TAT, PPIC, and tissue type plasminogen activator levels were significantly higher before HD than after 1 hour HD and at the end of HD, while the changes in plasma protein C antigen, protein S antigen, PCI antigen, APC-PCI complex, and APC-alpha 1AT complex were not significant after 1 hour of HD or at the end of HD compared to levels before HD. Plasma PCI levels were correlated with APC-PCI complex, suggesting that decreased PCI levels might be caused by the activation of protein C.

Adult↗

[A clinicobacteriologic study on clavulanic acid/amoxicillin in pediatric acute otitis media].

We carried out clinical and bacteriological studies on clavulanic acid/amoxicillin and amoxicillin in pediatric acute otitis media at 14 general practice settings. The results are summarized as follows. 1. The major isolated organisms from content of middle ear effusion were Streptococcus pneumoniae 31.8%, Haemophilus influenzae 35.8% and Moraxella subgenus Branhamella catarrhalis 1.5%. Similar results were observed for the major isolates organisms from content of nasopharynx Streptococcus pneumoniae 31.1%, Haemophilus influenzae 33.9% and Moraxella subgenus Branhamella catarrhalis 19.2%. 2. 42.2% of S. pneumoniae isolated from middle ear effusion were drug resistant S. pneumoniae (PISP, PRSP) and they were increasing year by year. 3. 46.7% of S. pneumoniae isolated from nasopharyngeal swab were drug resistant S. pneumoniae (PISP, PRSP) and they were increasing year by year. The incidence of drug resistant S. pneumoniae isolated from all cases and organisms were 26.3% and 14.5%, respectively. 4. On MIC90, antimicrobial activity of CVA/AMPC against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella subgenus Branhamella catarrhalis was superior to SBTPC. 5. In the evaluation of clinical efficacy, bacteriological efficacy and utility, CVA/AMPC-treated group was significantly superior to AMPC-treated group. 6. Adverse reactions were observed in 22% of CVA/AMPC-treated group, involving diarrhea and loose stool.

Acute Disease↗

[A clinicobacteriologic study on clavulanic acid/amoxicillin in pediatric sinusitis].

We carried out clinical and bacteriological studies on clavulanic acid/amoxicillin and amoxicillin in pediatric sinusitis at 11 general practice settings. The results are summarized as follows. 1. The major isolated organisms from content of middle meatus were Streptococcus pneumoniae 32.2%, Haemophilus influenzae 32.0% and Moraxella subgenus Branhamella catarrhalis 25.1%. Similar results were observed for the major isolates from nasopharynx. 2. 62.1% of S. pneumoniae isolated were drug resistant S. pneumoniae (PISP, PRSP) and they were increasing year by year. 3. Drug resistant S. pneumoniae was isolated from 38.6% of all cases. 4. Regarding MIC90, CVA/AMPC showed superior antimicrobial activity against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella subgenus Branhamella catarrhalis. 5. The clinical efficacy, bacteriological efficacy and utility of CVA/AMPC-treated group were 78%, 58% and 72.8%, respectively, and they were significantly superior to AMPC-treated group. 6. Adverse reactions were observed in 11.2% of CVA/AMPC group, involving diarrhea and stool loose and there was no statistical deference from those of AMPC group.

Amoxicillin↗

[Antimicrobial activities of meropenem against clinically isolated strains in 1997].

In order to evaluate antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates in 1997. The results were as follows; 1. Antimicrobial activities of MEPM against Gram-positive bacteria were stronger than those of cephems (CEPs) and were approximately equal to those of imipenem (IPM) and panipenem (PAPM). 2. Carbapenems showed strong antimicrobial activities against Enterobacteriaceae, Glucose non-fermentative Gram-negative rods and Bacteroides fragilis group that were multiple drug resistant including the third generation CEPs. Antimicrobial activities of MEPM against these organisms were stronger than those of IPM and PAPM. By comparing antimicrobial activities of MEPM against Gram-negative bacteria in 1997 with those obtained in 1993, increase of resistance was not observed. 3. MIC-ranges of MEPM were low against the resistant strains of Pseudomonas aeruginosa to IPM and PAPM. It was considered that these resistant strains were not expressing oprD products (D2 porin protein), forming main outer membrane porin channels of carbapenems and basic amino acids.

Bacteria↗

Growth disturbance in fetal liver hematopoiesis of Mll-mutant mice.

The MLL (ALL-1, HRX) gene is frequently involved in chromosomal translocations in acute leukemia and has homology with Drosophila trithorax, which controls homeobox gene expression and embryogenesis. To elucidate the function of Mll, we generated mice with a mutated Mll locus. Mice with a homozygous mutation were embryonic lethal and died at embryonic day 11.5 to 14.5, showing edematous bodies and petechiae. Histological examination revealed that hematopoietic cells were decreased in the liver of homozygous embryos, although they were composed of erythroid, myeloid, monocytic, and megakaryocytic cells with normal differentiation. Colony-forming assays using cells from fetal livers and yolk sacs showed that the number of colonies was markedly reduced and many of the colonies delayed to be recognized in Mllmu/mu embryos, although some of the colonies from Mllmu/mu embryos developed similarly with that from Mll+/+ and Mll+/mu embryos, suggesting the delayed onset of the proliferation of hematopoitic precursors. These data show that the hematopoietic precursors were greatly reduced in mutant mice, and suggest that Mll functions as a regulator of the growth of hematopoietic precursors.

Animals↗

Choroid plexus carcinoma in infants: report of two cases and review of the literature.

Choroid plexus carcinoma (CPC) is a rare malignant brain tumour which occurs predominantly in childhood. We present the cases of two infants with CPC. One, a 6-month-old boy with the tumour in the right lateral ventricle, who died of a postoperative intracranial haemorrhage and severe gastrointestinal bleeding, and the other, a 9-month-old boy with the tumour in the fourth ventricle, who has been well without recurrence for 12 months after total removal in combination with chemotherapy using cisplatin and VP-16 and local radiotherapy. In the 54 CPC cases in children under 2 years of age including our 2 cases in which the clinical results were described in the literature since 1983, tumour location (lateral ventricle, p = 0.0225), surgery (gross total resection, p = 0.0447), and chemotherapy (yes, p = 0.0010) were revealed to be significant positive prognostic factors by the univariate analysis using the log rank test, and surgery (gross total removal, p = 0.0259) and chemotherapy (yes, p = 0.0016) were independent, significant positive prognostic factors in the multivariate analysis using the Cox proportional hazard regression model. Although there is a risk in doing a statistical analysis of other people's reports, these results suggest that, at present, the gross total removal of the tumour with intensive chemotherapy is the best choice of initial treatment for young children with CPC, and that radiotherapy should be considered for patients after 24 months of age and/or should be performed locally.

Carcinoma↗

Vascular endothelial growth factor in brains with periventricular leukomalacia.

Vascular development was studied by means of immunohistochemistry, using a vascular endothelial growth factor (VEGF) antibody in human normal and periventricular leukomalacia brains. In the cerebral cortex, VEGF was expressed transiently in the endothelial cells of vessels in the leptomeninges, cortex, deep white matter, subependymal germinal layer, ependymal cells facing the lateral ventricles, and choroid plexus epithelia. In the leptomeninges, VEGF was expressed from 20 to 40 weeks gestation. In the cerebral cortex and deep white matter, VEGF was expressed from 17 weeks gestation, increased with maturation, was highest between 24 and 28 weeks gestation, and decreased gradually thereafter. In the subependymal germinal layer, VEGF was expressed the earliest at 9 weeks gestation, increased with maturation, was highest between 20 and 24 weeks gestation, and then decreased. In the ependymal cells and choroid plexus epithelia, VEGF was expressed between 22 and 40 weeks gestation and between 9 and 37 weeks gestation, respectively. VEGF may be transiently expressed in the vessels in the fetal and neonate periods in connection with vascular maturation and proliferation. In periventricular leukomalacia brains, VEGF was expressed in both astrocytes and endothelial cells in vessels that comprised neovascularization around foci of necrosis. VEGF plays important roles in embryonic angiogenesis and neovascularization around foci of necrosis.

Astrocytes↗

Increased thrombopoietin levels in idiopathic thrombocytopenic purpura patients with a poor response to steroid therapy.

The serum thrombopoietin (TPO) levels in 61 idiopathic thrombocytopenic purpura (ITP) patients were found to be slightly increased compared with those of 29 normal subjects. The TPO levels of the 15 ITP patients who had a poor response to steroid therapy (i.e. an unchanged platelet count) were higher than those of the 22 ITP patients who had a good response to steroid therapy (i.e. an increased platelet count) and the normal subjects. The TPO levels in the 15 ITP patients whose platelet count was higher than 10 x 10(4)/microl after the discontinuation of steroid therapy significantly higher than those of the normal subjects. The platelet-associated immunoglobulin G (PAIgG) levels in the ITP patients who had a poor response to steroid therapy were slightly increased compared with the normal subjects and the ITP patients who had a good response to the steroid therapy and the nine ITP patients who did not undergo the steroid therapy. The serum TPO level was negatively correlated only with the megakaryocyte count in the ITP patients, and the megakaryocyte count in the ITP patients who had good responses to the steroid therapy was higher than that in those who had poor responses. These data suggest that serum TPO levels might be important for the prediction of the outcome of ITP patients who receive steroid therapy.

Adolescent↗

Changes in plasma tissue factor pathway inhibitor levels during the clinical course of disseminated intravascular coagulation.

In healthy volunteers, the plasma total tissue factor pathway inhibitor (TFPI) level was 68.7+/-14.1 ng/ml; the plasma free TFPI level, 17.7+/-5.4 ng/ml; the lipoprotein-associated TFPI (LP-TFPI), 51.1+/-12.0 ng/ml; the free TFPI/total TFPI ratio 0.26+/-0.07; and the plasma tissue factor levels were 149+/-46 pg/ml. Plasma tissue factor levels in patients with disseminated intravascular coagulation (DIC) were significantly higher than those in pre-DIC patients or in non-DIC patients. Plasma total-TFPI, free-TFPI and LP-TFPI levels were significantly higher in DIC patients than those in pre-DIC patients or in non-DIC patients. Before the onset of DIC, the plasma levels of tissue factor gradually increased, and 3 days before the onset of DIC they were significantly higher than those in non-DIC patients. The plasma levels of tissue factor reached their highest level 1 day before the onset of DIC and gradually decreased after the onset of DIC. Plasma levels of total-TFPI, free-TFPI, and LP-TFPI gradually increased before the onset of DIC, and the total-TFPI and LP-TFPI reached their highest levels at the onset of DIC. Plasma free-TFPI reached highest level one day after the onset of DIC. During the clinical course of DIC, the plasma level of tissue factor was the first to increase, then that of LP-TFPI and finally the free-TFPI plasma levels. These differences in the peak plasma levels of tissue factor, free-TFPI, and LP-TFPI might be related to the clinical course of DIC.

Disseminated Intravascular Coagulation↗

Influence of inoculation site of combined oil-adjuvanted vaccine on the antibody response in chickens.

Inactivated oil-adjuvanted vaccines for ND, IB, and IC serotypes A and C (OILVAX NB2AC) have been marketed from 1993. In the outdoors, various inoculation sites have been used in chickens because to make the inoculation procedure easier. We examined whether differences would be obtained in the antibody response according to the inoculation sites; the subcutaneous inoculation into the back of the neck for OILVAX use, and the thigh, lower thigh, breast and shoulder muscle for the possible application of the inoculation outdoors. The clear order was not found in the NDV-HI titer, IBV-SN titer against Nerima or TM-86 among the inoculation sites used during the examination period. The IC serotypes A and C HI titers did vary among the inoculation sites; the subcutaneous inoculation produced the highest antibody titer, and high antibody titers were observed in the order of lower thigh muscle > or = thigh muscle > breast muscle > or = shoulder muscle inoculation.

Adjuvants, Immunologic↗

[Antimicrobial activities of cefcapene against clinical isolates from respiratory tract infections of outpatients].

In order to evaluate antimicrobial activity of cefcapene (CFPN), minimum inhibitory concentrations (MICs) of CFPN and reference drugs were determined against clinical isolates from respiratory tract infection of out patients that were obtained in our laboratory from January to June of 1997. The results are summarized as follows; 1. The MIC90 of CFPN against penicillin (PC)-susceptible Streptococcus pneumoniae (PSSP) was equal to those of benzylpenicillin (PCG), ampicillin (ABPC) and cefditoren (CDTR), and was lower than those of cefaclor (CCL), cefdinir (CFDN) and erythromycin (EM). 2. The MIC90 of CFPN against PC-intermediate S. pneumoniae (PISP)/PC-resistant S. pneumoniae (PRSP) was equal to that of CDTR, and was lower than those of PCG, ABPC, CCL, CFDN and EM. CFPN showing strong antimicrobial activities against PISP. 3. CFPN showed strong antimicrobial activities against beta-lactamase producing and non-producing Haemophilus influenzae. The MIC90 of CFPN was stronger than those of ABPC, CCL, CFDN and EM, and was approximately equal to that of CDTR. CFPN also showed strong antimicrobial activities against strains which did not produce any beta-lactamase and were resistant to CCL with MIC of > or = 25 micrograms/ml. 4. Antimicrobial activities of CFPN against Moraxella subgenus Branhamella catarrhalis was stronger than that of ABPC and CCL, though the MIC90 of CFPN was rather high, 3.13 micrograms/ml. 5. CFPN showed strong antimicrobial activities against PISP and beta-lactamase producing H. influenzae, and also against the CCL-resistant H. influenzae indicative mutations of penicillin-binding proteins (PBPs). From those results, cefcapen-pivoxil was found to be clinically effective against community acquired respiratory tract infection.

Cephalosporins↗