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Biomedical subjects

K Nagasawa

Publications and source records attributed to K Nagasawa.

At least 19 recordsLinked to original sources
PubMed2006

Prevention of steroid-induced osteonecrosis of femoral head in systemic lupus erythematosus by anti-coagulant.

Although osteonecrosis of femoral head (ONF) is one of the serious complications in systemic lupus erythematosus (SLE) associated with corticosteroid therapy, there has been few trials of prevention of ONF described. We aimed to prevent ONF in steroid-treated SLE patients using anticoagulant, warfarin, conducting a multicenter prospective study. Sixty newly diagnosed SLE patients requiring 40 mg/day or more prednisolone were alternately assigned to either of two groups; a warfarin group and a control one. Warfarin (1 to approximately 5 mg/day) was started together with the beginning of steroid therapy and continued at least for three months. Patients were observed for the development of silent ONF by magnetic resonance imaging (MRI) and symptomatic ONF by plain radiography for over five years. The warfarin group consisted of 31 patients (62 hips) and the control one 29 patients (58 hips). Silent ONF developed in 13 hips (21%) and 19 hips (33%) in the warfarin group and the control group, respectively (P = 0.13). On the other hand, warfarin tended to prevent symptomatic ONF; only three hips of 62 (4.8 %) in the warfarin group and eight hips of 58 (14%) in the control group (P = 0.08) developed silent ONF. It was also found that silent ONF developed, if it did, very early; within three months in 16 of 18 patients (89%). Among risk factors for silent ONF, steroid pulse therapy was most outstanding and it seemed to overcome the effect of warfarin. Taken together, for the time being, anti-coagulant therapy, if not significantly sufficient, may be of use for the prevention of steroid-induced ONF in SLE. We consider that this study added to important evidence for the pathogenesis and prevention of ONF.

Adolescent↗
PubMed2005

Ex vivo CD(+) T-cell cytokine expression from patients with Sjögren's syndrome following in vitro stimulation to induce proliferation.

OBJECTIVE: To assess ex vivo CD4(+) T-cell cytokine expression from patients with primary Sjögren's syndrome (SS) following in vitro stimulation to induce proliferation, as proliferation is closely related to differentiation of cytokine-producing cells. METHODS: Peripheral blood mononuclear cells (PBMCs) separated from primary SS patients (n = 28) and controls (n = 25) were analysed. PBMCs were stimulated with concanavalin A followed by phorbol 12-myristate 13-acetate and ionomycin. Intracellular interferon-gamma (IFN-gamma) and interleukin-4 (IL)-4 in proliferating CD4(+) T cells were assessed by flow cytometry. The proportion of cytokine-producing cells and proliferating cells in each division cycle was assessed using [5(and 6)-carboxyfluorescein diacetate, succinimidyl ester]-labelled CD4(+/-) T cells. RESULTS: The proportion of IFN-gamma+ proliferating CD4(+) T cells in each cell division cycle from extraglandular SS was increased in glandular SS patients compared glandular SS patients with controls (P<0.05 approximately 0.01). The percentage of IFN-gamma single positive proliferating CD4(+) T cells was greater in extraglandular SS patients (26.7+/-14.1%) compared with glandular SS (9.9 +/- 9.1%) (P<0.01) and controls (9.4 +/- 5.8%) (P<0.001). There was no significant difference in the percentages of IL-4(+) proliferating CD4(+) T cells among the groups. However, the proliferating response of CD4(+) T cells was significantly decreased in extraglandular SS patients (percentage of proliferating cells 38.4 +/- 18.6%) compared with that in glandular SS patients (64.2 +/- 17.2%) (P<0.05) and controls (63.1+/-10.6%) (P<0.01). CONCLUSIONS: CD4(+) T cells from extraglandular SS patients may have a predisposition for entry into the IFN-gamma-producing effector pathway as a result of the stimulations. These results are helpful for understanding the immunological difference between glandular and extraglandular SS and the mechanisms of disease progression.

Adult↗
PubMed2005

A phase I-II trial of autologous peripheral blood stem cell transplantation in the treatment of refractory autoimmune disease.

OBJECTIVES: To carry out a phase I-II trial to elucidate the feasibility and efficacy of high dose cyclophosphamide (CY) supported by autologous peripheral blood stem cell transplantation (PBSCT) in the treatment of severe and refractory autoimmune disease (AD). METHODS: Peripheral blood stem cells (PBSCs) were mobilised during haematological recovery after relatively high dose CY (2 g/m2) for 2 days, followed by administration of granulocyte colony stimulating factor. After collecting PBSCs--more than 2x10(6) CD34+ cells/kg--by apheresis, CD34+ cells were immunologically selected and cryopreserved. Eight patients were enrolled--five had systemic sclerosis (SSc) alone, one had SSc with systemic lupus erythematosus, one amyopathic dermatomyositis (ADM), and one Wegener's granulomatosis (WG). All of the patients were treated with high dose CY (50 mg/kg) for 4 days and autologous PBSCT. RESULTS: Haematopoietic reconstitution was rapid and sustained. Toxicity due to the regimen included various infections such as pneumonia, sepsis, cystitis, herpes zoster, and acute heart failure. However, there was no treatment related mortality. Encouraging results were obtained after autologous PBSCT. Sclerosis of the skin was markedly improved in all of the patients with SSc. Interstitial pneumonia (IP), evaluated by PaO2, serum KL-6 levels, and pulmonary high resolution computed tomography, improved significantly. In a patient with ADM, severe and progressive IP also improved markedly. In a patient with WG, the size of the left orbital granuloma decreased substantially, resulting in reduction of the exophthalmos. CONCLUSIONS: These observations suggest that high dose CY with autologous PBSCT is feasible and may be effective in the treatment of severe and refractory AD.

Adult↗
PubMed2005

Elevation of both cyclooxygenase-2 and prostaglandin E2 receptor EP3 expressions in rat placenta after uterine artery ischemia-reperfusion.

Intrauterine growth restriction (IUGR) has a multifactorial pathogenesis and is an important cause of perinatal mortality. The relationship between fetal weight and placental blood flow in an animal model of IUGR has been investigated, showing that fetal growth is regulated by placental blood flow. The aim of the present study was to determine whether ischemia-reperfusion (I/R) injury stimulates the prostaglandin E2 (PGE2) system or the vascular endothelial growth factor (VEGF) system in the placenta of a rat IUGR model. COX-2 is reported to be involved in ischemic damage in many organs. There are 4 types of PGE2 receptor (EP1, EP2, EP3 and EP4). It is well known that EP1 and EP3 is associated with vasoconstriction. In the present study, vessels were occluded in the right uterine horn on day 17 of pregnancy in rats, and the clamps were removed after 30 min of ischemia. At 24h, 48 h, and 5 days after I/R injury, the live fetuses and placentas were obtained by cesarean section. This study revealed that I/R injury caused IUGR 5 days after the treatment. COX-2 expression and EP3 receptor expression were significantly elevated at 24h after I/R injury, but VEGF mRNA expression was not altered in the placenta from the ischemic horn compared with the non-ischemic horn. These results suggested that induction of the COX-2-EP3 system in the placenta may be one of the causes of IUGR induced by uterine ischemia, because the EP3 receptor and PGE2 are well known to mediate vasoconstriction in many organs.

Animals↗
PubMed2005

Very early development of steroid-associated osteonecrosis of femoral head in systemic lupus erythematosus: prospective study by MRI.

The objective of this study was to define prospectively the early development of corticosteroid-induced osteonecrosis of femoral head (ONF) in patients with systemic lupus erythematosus (SLE) and to identify the association of initial steroid treatment with the development of early (silent) ONE Forty-five patients who were newly diagnosed as having SLE and required 40 mg/day or more prednisolone were enrolled. To detect silent ONF, examinations using magnetic resonance imaging (MRI) were done three months after starting steroid therapy, followed by every year's MRI and plain radiography for over five years. Clinical and laboratory data were compared between silent ONF and non-ONF groups. Of 45 patients, 15 (33%) developed silent ONF and five (11%) symptomatic ONE It was of interest that MRI detected silent ONF very early (by three months) in 14 patients (93%). It should be noted that pulse therapy with 1000 mg/day methylprednisolone was found to be done very frequently (13 of 15, 87%) in the silent ONF group compared to non-ONF group (11 of 30, 37%) (P < 0.01) although other clinical features were not significantly different between both groups. High dose corticosteroids caused elevation of serum levels of total cholesterol, albumin, and leukocyte count in most of patients. The degree of elevation of those parameters at one or three months was more prominent in the silent ONF group. In particular, the change ratio of total cholesterol at one month was outstanding in the silent ONF group compared to non-ONF group (0.551 versus 0.374, P < 0.05). In conclusion, pathological ONF develops very early in one-third of SLE patients who received high dose corticosteroids and steroid pulse therapy could be a significant risk factor. An abrupt elevation of serum total cholesterol and/or sensitivity to steroids seem to be associated with the pathogenesis of ONF.

Adolescent↗
PubMed2004

Increased entry of CD4+ T cells into the Th1 cytokine effector pathway during T-cell division following stimulation in Behcet's disease.

OBJECTIVES: To investigate the relationship between the production of Th1/Th2 cytokines and cell kinetics, cell division and proliferation in patients with Behçet's disease (BD). METHODS: Peripheral venous blood was drawn from patients with BD (n = 24; 10 patients with active and 14 patients with inactive BD) and normal subjects (n = 22). Peripheral blood mononuclear cells were separated immediately and were cultured with concanavalin A (Con A) followed by phorbol 12-myristate 13-acetate and ionomycin (PMA+Ion). Intracellular cytokine production of interferon-gamma (IFN-gamma) (Th1) and IL-4 (Th2) in CD4(+) T cells was determined by flow cytometry. Furthermore, CD4(+) T cells labelled with CFSE [5 (and 6) carboxyfluorescein diacretate, succinimidyl ester] were stimulated and the cells were analysed for entry into the cytokine production effector pathway during cell division in active BD and normal subjects. RESULTS: In active BD, enhanced entry into the Th1 response effector pathway of CD4(+) T cells was observed after stimulation with Con A followed by PMA+Ion. Analysis of CD4(+) T cells at an identical cell division number in response to Con A followed by PMA+Ion revealed that IFN-gamma-producing cells were increased in active BD patients compared with normal subjects. These results suggest that the Th1 response of dividing CD4(+) T cells is predominantly operating in active BD. Dividing CD4(+) T cells stimulated with Con A followed by PMA+Ion showed a phenotype of activated effector memory T cells (CD45RA(low), CD45RO(+), CD69(high)). CONCLUSIONS: Cell kinetics play a crucial role in Th1 cell differentiation and pathophysiology in BD.

Acute Disease↗
PubMed2003

Retinal findings in systemic sclerosis: a comparison with nailfold capillaroscopic patterns.

OBJECTIVE: To determine the prevalence of retinal disease in systemic sclerosis (SSc) and to characterise the findings of retinopathy. Additionally, to analyse the association of retinal disease with other clinical/laboratory findings, particularly the findings of nailfold capillaries in patients with SSc. METHODS: Photographs of the ocular fundi were taken and were evaluated by an ophthalmologist who was unaware of the SSc status of the patients. The nailfold capillaries were analysed with a dermatoscope. Patients were divided into two groups according to the presence (group A) or absence (group B) of retinal disease. RESULTS: Retinal findings of the patients with SSc consisted of hard exudates, vascular tortuosity, microhaemorrhage, and macular degeneration. The prevalence of retinal disease among the patients with SSc was 34% (10/29), compared with 8%(3/38) among the controls (p=0.011). The mean systolic blood pressure and the age of the patients in group A were significantly higher than those in group B. However, there was no significant difference in the nailfold capillary damage between groups A and B. CONCLUSION: Retinal abnormalities are often seen in patients with SSc and they may reflect the vascular changes characteristic of SSc. However, retinal changes may differ in quality from the changes of nailfold capillaries.

Capillaries↗
PubMed2003

Persistence of systolic coronary flow reversal predicts irreversible dysfunction after reperfused anterior myocardial infarction.

OBJECTIVE: To investigate serial assessments of systolic coronary flow reversal in the infarct related artery for predicting poor left ventricular functional recovery after reperfused acute myocardial infarction. SETTING: Regional hospital. PATIENTS AND METHODS: 49 patients with anterior acute myocardial infarction had transthoracic Doppler echocardiography to record coronary flow velocity in the left anterior descending coronary artery immediately after successful primary coronary angioplasty (day 0), and at 48 hours, one week, and three weeks. MAIN OUTCOME MEASURES: Coronary flow velocity at each time point; regional wall motion score index (RWMSI) at day 0 and at three weeks. Irreversible dysfunction was defined as a decrease in RWMSI to < 0.22. RESULTS: Measurements of coronary flow velocity could be made in 45 patients. Patients were divided into three groups: no systolic flow reversal (group 1, n = 27), systolic flow reversal observed only on day 0 (group 2, n = 8), and systolic flow reversal persisting until 48 hours (group 3, n = 10). Although baseline RWMSI was similar among the three groups, the value at three weeks was significantly higher in group 3 than in the other two groups. In predicting irreversible dysfunction, the persistence of systolic flow reversal up to 48 hours had a higher positive predictive value (100%) than the presence of systolic flow reversal on day 0 (67%, p < 0.04). The negative predictive value of systolic flow reversal at 48 hours (83%) was comparable in accuracy to the presence of systolic flow reversal on day 0 (85%, NS). CONCLUSIONS: In reperfused anterior acute myocardial infarction, serial assessment of coronary flow velocity in the left anterior descending coronary artery is feasible using transthoracic Doppler echocardiography, and the persistence of systolic flow reversal at 48 hours is a more specific marker of irreversible dysfunction than peak creatine kinase or diastolic deceleration time.

Adult↗
PubMed2002

Studies on the metabolic fate of M17055, a novel diuretic (6). Assessment for drug-drug interactions of M17055 in metabolism, distribution and excretion.

1. The potential of M17055, a novel diuretic candidate, to affect the activities of human CYP enzymes, alter the plasma unbound fraction and compete with concomitant drugs in renal secretion as part of an assessment for drug-drug interactions in metabolism, distribution and excretion was investigated. 2. The effects of M17055 on the activities of human CYP1A2, CYP2E1, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 were considered negligible at clinically relevant concentrations. 3. The majority of M17055 (99%) was bound to human plasma proteins, but it is unlikely to alter the binding of other clinically relevant drugs. 4. The renal clearance of M17055 (corrected for the plasma unbound fraction in male rats) substantially exceeded the glomerular filtration rate and was markedly reduced by treatment with probenecid, suggesting that the renal excretion of M17055 is controlled predominantly by an active secretion mechanism. 5. The results show that M17055 is unlikely to cause or undergo significant pharmacokinetic interactions with concomitant drugs in metabolism and distribution. However, when it is administered simultaneously with certain organic anions, drug-drug interactions during kidney excretion may be possible.

Animals↗
PubMed2001

Total synthesis and antifungal activity of 9-methoxystrobilurin L as the originally proposed 1,4-benzodioxan structure.

Total synthesis of both enantiomers of 9-methoxystrobilurin L as the originally proposed 1,4-benzodioxan structure was successfully achieved. The 1H and 13C NMR spectra of synthesized 9-methoxystrobilurin L were compared with those of a naturally-occurring sample. It was strongly indicated that naturally-occurring 9-methoxystrobilurin L has not the originally reported 1,4-benzodioxan structure but a 1,5-benzodioxepin structure, the same as previously reported 9-methoxystrobilurin K. Antifungal activities of the synthesized compounds toward several typical fungi were also examined, and they were less active than 9-methoxystrobilurin K.

Acrylates↗
PubMed2001

Association of tumor necrosis factor receptor type II polymorphism 196R with Systemic lupus erythematosus in the Japanese: molecular and functional analysis.

OBJECTIVE: To investigate whether a polymorphism(s) or mutation(s) in the tumor necrosis factor receptor II (TNFRII) gene is involved in the pathogenesis of systemic lupus erythematosus (SLE). METHODS: All 10 exons of the TNFRII gene were analyzed by exon-specific polymerase chain reaction-single-strand conformation polymorphism, followed by nucleotide sequencing of exons that displayed aberrant bands. To analyze the function of the TNFRII polymorphisms, the full-length TNFRII complementary DNA of each allele was transfected in HeLa cells and then studied for specific binding of 125I-TNFalpha, as well as interleukin-6 (IL-6) production and cytotoxic activity after treatment with recombinant human TNFalpha. RESULTS: We identified 4 polymorphisms, at codons 56, 181, 196, and 232. The latter 2 had amino acid substitutions M196R and E232K, respectively. Only the 196R allele was significantly associated with SLE in our 105 Japanese SLE patients, with an allele frequency of 20.5%, compared with 12.6% in 99 healthy controls (P = 0.0335). More importantly, using TNFRII-transfected HeLa cells, we demonstrated significantly increased IL-6 production by 196R TNFRII compared with 196M TNFRII. The cytotoxic activity induced by 196R TNFRII was also increased compared with that of 196M TNFRII. This increase was achieved without affecting the binding affinity of TNFalpha to TNF-RII, as demonstrated by the finding that specific TNFalpha binding to the HeLa transfectants of 196R and 196M TNFRII was similar, with Kd values of 3.12 x 10(-10)M and 4.34 x 10(-10)M, respectively. CONCLUSION: These results suggest that 196R TNFRII, which transduces the signals of TNFalpha more effectively than does 196M TNFRII, is involved in the pathogenesis of SLE.

Adolescent↗
PubMed2001

Pharmacokinetics of dicrofenac after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction.

We investigated the pharmacokinetics of diclofenac, one of the important analgesics in palliative care, after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction. In rectal-resected rabbits, its bioavailability after rectal administration was significantly lower than that in normal rabbits, and furthermore that after intracolostomal administration was significantly lower than that in rectal-resected rabbits. This decreased bioavailability in rabbits with rectal resection and colostoma construction was thought to be due to the increased first-pass effect. With increase in the dose up to 1.5-fold, the plasma concentrations in both rectal-resected and colostoma-constructed rabbits increased to the normal rabbit level. These results indicate that the bioavailability of diclofenac sodium after its rectal and intracolostomal administration decreases, and that an increased dose can restore the decreased plasma concentration. There was no difference in the plasma concentration with diclofenac sodium suppositories between administration into the normal rectum and the remaining rectum following colostoma construction, and the remaining rectum was found to be a useful administration route for suppositories. Therefore, it was indicated that when administering diclofenac sodium suppositories to rectal-resected and colostoma-constructed patients, the dose should be increased, because the pharmacokinetics of diclofenac was similar in rabbits and human.

Administration, Oral↗
PubMed2001

Collagen-induced arthritis in TNF receptor-1-deficient mice: TNF receptor-2 can modulate arthritis in the absence of TNF receptor-1.

TNF is a potent proinflammatory cytokine important for the development of arthritis in human and animals. We have investigated the roles of TNF receptor-1 (TNFR1) and TNF receptor-2 (TNFR2) in collagen-induced arthritis (CIA) by inducing CIA in mice genetically deficient in TNFR1. TNFR1-/- mice developed arthritis with similar incidence and severity as TNFR1+/- littermates, indicating that TNFR1 is redundant for the development of CIA. Anti-type II collagen (CII) antibody levels and T cell responses to CII did not differ between TNFR1-/- mice and controls. Neutralization of TNF with soluble TNF binding protein suppressed the development of arthritis in TNFR1+/- mice but not in TNFR1-/- mice, indicating that TNFR2 cannot substitute for TNFR1 for the proinflammatory function. To further investigate the functions of TNFR2, TNFR1-/- mice were injected with murine TNF-alpha at different stages during the course of CIA. Repeated TNF-alpha injection during the early induction phase enhanced the development of arthritis, but inhibited arthritis when administered during the late progression phase. These results show that the engagement of TNFR2 by TNF is involved in the development of CIA in the absence of TNFR1 and that opposing signals can be transduced by TNFR2.

Animals↗
PubMed2001

Primary pericardial mesothelioma: a case report.

The imaging features of primary pericardial mesothelioma have rarely been described. Herein we present a case report of its diagnostic-pathologic features. Chest computed tomography (CT) revealed an irregularly enhanced mass occupying the entire pericardial space and surrounding the superior vena cava. At autopsy, the tumor was found to fill the pericardial space completely, and to extend to the superior vena cava through the superior pericardial sinus. The CT features of the tumor were correlated well with those revealed at autopsy, and provided satisfactory information regarding the presence and the extension of the tumor.

Aged↗
PubMed2001

Conservative treatment for trigger thumb in children.

Conservative treatment was performed for 60 trigger thumbs (19 right, 17 left, 12 bilateral) in 48 children (19 boys, 29 girls); the age at initial diagnosis ranged from 0 to 48 months old (mean 26 months). In this approach, only passive exercise of the affected thumb was performed by the mother. As a result, two patients (two thumbs) dropped out of treatment. Fifty-six thumbs out of 58 showed a satisfactory result (96%). Sixteen thumbs (in stage 2) and eight thumbs (in stage 3) showed completely recovery. Four thumbs (in stage 3) have not yet improved. In conclusion, we suggest that conservative treatment is effective for trigger thumbs in stage 2, while surgical therapy was thought to be indicated for stage 3 before the age of 3 years to avoid flexion deformity.

Child↗
PubMed2001

Empty sella in children as a key for diagnosis.

We performed magnetic resonance imaging of the pituitary gland in 354 children who were under the care of our pediatric neurological outpatient department. Among them, an empty sella was recognized in 11 children, who all showed normal hormonal results. The frequency of an empty sella was significantly high in idiopathic intracranial hypertension (4/4; P<0.0001) and nevoid basal cell carcinoma syndrome (3/5; P<0.0001). The ratio of an empty sella in children, excluding patients with idiopathic intracranial hypertension and nevoid basal cell carcinoma syndrome, is estimated to be 4/345 (1.2%), which is markedly lower than that in adults. Magnetic resonance imaging of the pituitary gland in children could provide important clues for the diagnosis of idiopathic intracranial hypertension or nevoid basal cell carcinoma syndrome.

Adolescent↗