PubMed Health⌕ Search

Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 19 recordsLinked to original sources

Relativistic calculation of nuclear magnetic shielding tensor including two-electron spin-orbit interactions.

A relativistic calculation of nuclear magnetic shielding tensor including two-electron spin-orbit interactions is performed. In order to reduce the computational load in evaluating the two-electron relativistic integrals, the charge density is approximated by a linear combination of the squares of s-type spatial basis functions. Including the two-electron spin-orbit interaction effect is found to improve the calculation results.

Journal Article↗

Relativistic calculation of nuclear magnetic shielding using normalized elimination of the small component.

The normalized elimination of the small component (NESC) theory, recently proposed by Filatov and Cremer, is extended to include magnetic interactions and applied to the calculation of the nuclear magnetic shielding in HX (X=F, Cl, Br, I) systems. The NESC calculations are performed at the levels of the zeroth-order regular approximation (ZORA) and the second-order regular approximation (SORA). The calculations show that the NESC-ZORA results are very close to the NESC-SORA results, except for the shielding of the I nucleus. Both the NESC-ZORA and NESC-SORA calculations yield very similar results to the previously reported values obtained using the relativistic infinite-order two-component coupled Hartree-Fock method. The difference between NESC-ZORA and NESC-SORA results is significant for the shieldings of iodine.

Journal Article↗

Self-monitoring of home blood pressure with estimation of daily salt intake using a new electrical device.

We investigated a simple device to monitor daily salt intake at home and examined the relationship between salt excretion and morning blood pressure in order to enable patients to better manage daily salt intake and hypertension. The correlation between 24-h urinary salt excretion and measured value with salt monitor from overnight urine was significant (n = 224, r = 0.72, P < 0.001). A total of 46 volunteers participated for more than 3 weeks by measuring daily salt intake and morning blood pressure. The relationship between predicted daily salt excretion and blood pressure was examined with use of 3-day moving average. Mean salt excretion and systolic blood pressure (SBP) significantly decreased by the end of the trial (i.e., salt excretion decreased from 158+/-31 to 149+/-30 mmol/day and SBP from 137+/-17 to 133+/-16 mm Hg). Of 46 participants, 18 (39%) had a significant correlation between predicted daily salt excretion and blood pressure (r > 0.4, P < 0.05, n > 21), indicating sodium sensitivity. An additional 17% had a positive correlation that did not reach statistical significance (0.2 < r < or = 0.4), and the remaining 44% had no correlation (r < or = 0.2). Mean decrease in blood pressure per decrease in salt (g) (17 mmol) intake in the 18 participants with a significant correlation was 3.3 mm Hg (SBP) and 1.5 mm Hg (diastolic blood pressure), which was higher than that reported for other studies. Hypertensive patients not using medication showed the largest decrease. We conclude that daily monitoring of salt intake and morning blood pressure will be useful for management of hypertension.

Blood Pressure Determination↗

Counterion specificity in the phase behavior of tetradecyldimethylamine oxides at different degrees of protonation.

Effects of counterion species on the aggregate structure of tetradecyldimethylamine oxide (C14DMAO) accompanying the protonation were examined by viscoelastic properties and phase behavior observations. Different extents of the synergetic behavior between protonated and non-protonated amine oxides were observed depending on the counterion species, which follow the Hofmeister, or the lyotropic, series. The efficacy of monovalent anions with respect to the increasing the surfactant packing parameter was as follows: salicylate>perchlorate>nitrate>bromide>chloride, formate. Vesicle formation was found in the case of salicylate and perchlorate anions and elongation of rodlike micelles was observed for nitrate, bromide, sulfate, tartronate and tartrate anions but little effects in the case of chloride and formate anions. The observed ionic specificity is well correlated with the free energy of hydration of counterions.

Journal Article↗

Coherent population transfer in an atom by multiphoton adiabatic rapid passage.

Coherent population transfer in an atom using a sequence of adiabatic rapid passages through single-photon resonances is well-known, but it requires that the frequency sweep match the changing frequencies of the atomic transitions. The same population transfer can be effected via a single multiphoton adiabatic rapid passage, which requires only a small frequency sweep, if it is possible to select the desired multiphoton transition from the many possible transitions. Here we report the observation of population transfer between Rydberg states by high order multiphoton adiabatic rapid passage.

Journal Article↗

Hematopoietic stem cell transplantation for 30 patients with primary immunodeficiency diseases: 20 years experience of a single team.

We retrospectively analyzed our results of 30 patients with three distinctive primary immunodeficiency diseases (PIDs)--severe combined immunodeficiency (SCID, n = 11), Wiskott-Aldrich syndrome (WAS, n = 11) and X-linked hyper-immunoglobulin M (IgM) syndrome (XHIM, n = 8)--who underwent hematopoietic SCT (HSCT) during the past 20 years. Until 1995, all donors were HLA-haploidentical relatives with T-cell depletion (TCD) (n = 8). Since 1996, the donors have been HLA-matched related donors (MRD) (n = 8), unrelated BM (UR-BM) (n = 7) and unrelated cord blood (UR-CB) (n = 7). Twenty-seven of 30 patients had various pre-existing infections with or without organ damages before HSCT. Conditioning regimen and GVHD prophylaxis were determined according to disease, donor and pretransplant status. Although one of eight patients transplanted with TCD is alive with full engraftment, the other seven died. On the other hand, 18 of 22 patients transplanted without TCD are alive and well, including six of eight transplanted from MRD, seven of seven from UR-BM and five of seven from UR-CB. All 19 survivors did not require Ig supplementation after HSCT. These results indicate that UR-CBT as well as UR-BMT provides good results for PID comparable to MRD-SCT, and that early diagnosis, HSCT at early stage, careful supportive therapy and monitoring for various pathogens are important for the successful HSCT.

Adolescent↗

Clinical impact of interstitial pneumonia following surgery for lung cancer.

BACKGROUND: Operative morbidity in patients with lung cancer associated with perioperative interstitial pneumonia (IP) has emerged as a serious problem. PATIENTS AND METHODS: We studied the clinical impact of perioperative related IP in 11 patients (IP group: 7 preoperative known, 4 acute onset) of 473 lung cancer patients who received a pulmonary resection. The IP group was compared to the remaining 462 patients (non-IP group). Demographic data, clinical presentation, and serum KL-6 levels were compared. RESULTS: There were no differences in age, gender, type of surgery, and pulmonary function except for % DLco between the non-IP and IP groups. The IP group showed a higher in-hospital mortality (n=2: 18.3%) than that of the non-IP group (n=3: 0.6%) (P<0.005). Seven patients with underlying IP with high KL-6 levels showed an uneventful recovery. Two patients with postoperative onset of acute IP had a fatal course associated with elevation of serum KL-6 levels. CONCLUSIONS: Postoperative development IP is a serious complication with high mortality, and serial measurement of KL-6 levels is useful to assess the activity of IP.

Adolescent↗

Spread of malignant cells in the surgical margin with stapled excision of lung cancer: comparison of aggressive clump and less traumatic jaw closure type staplers.

BACKGROUND: During stapled excision of lung cancer tissue, malignant cells can spread in the surgical margin. Stapling methods can be classified as aggressive clumping (AC) and less traumatic jaw closing (LTJC) types, thus the ratio of malignant margins may differ between stapler types. METHODS: The malignant status of the stapled margin was retrospectively investigated in 112 cases using a cytology technique. Stapler type, maximum tumor diameter, distance from surgical margin, thoracotomy type, and tumor location were used as variables. In addition, clinical results of excision cases were assessed. RESULTS: The ratio of malignant margins was 22/54 (41 %) in the AC group and 11/58 (19 %) in the LTJC group ( P = 0.01). Multivariate analysis revealed that the stapling method and tumor location were an independently significant factor. Surgical margin recurrence occurred only in 4 (57 %) of 7 cases with malignant margin. CONCLUSIONS: The AC type method showed a greater potential to spread malignant cells, thus there seems to be a higher possibility of regional relapse with that technique.

Aged↗

Effects of nifedipine and interleukin-1alpha on the expression of collagen, matrix metalloproteinase-1, and tissue inhibitor of metalloproteinase-1 in human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: Nifedipine-induced gingival overgrowth is known to be characterized by fibrosis and some degree of inflammation. However, the molecular mechanism of the fibrosis is not fully understood. The purpose of this study was to investigate in vitro the effects of nifedipine and interleukin-1alpha on the molecules involved in fibrosis, namely type I collagen, matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1). MATERIAL AND METHODS: Four human gingival fibroblast strains, derived from four healthy volunteers, were cultured in media containing nifedipine (1 microg/ml), with or without interleukin-1alpha (0.05 ng/ml). The mRNAs of type I collagen, MMP-1, and TIMP-1 were measured by reverse transcription-polymerase chain reaction (RT-PCR). The proteins of MMP-1 and TIMP-1 were examined by enzyme-linked immunosorbent assay (ELISA), and the ratios of MMP-1 to TIMP-1 proteins were calculated. RESULTS: The mRNA expression of type I collagen showed no significant change. Both mRNA expression and protein production of MMP-1 were up-regulated by interleukin-1alpha, either alone or in combination with nifedipine, whereas those of TIMP-1 were up-regulated by nifedipine alone or in combination with interleukin-1alpha. The ratio of MMP-1 to TIMP-1 was not changed by nifedipine alone, but it was increased by interleukin-1alpha alone or in combination with nifedipine. However, in two of the four cell strains tested, nifedipine reduced the ratio of MMP-1 to TIMP-1 compared with that for interleukin-1alpha alone. CONCLUSION: These results suggest that nifedipine may predispose to fibrosis in some individuals in situations where interleukin-1 levels are raised.

Adolescent↗

Effects of therapeutic agents on cellular respiration as an indication of metabolic activity.

Animal experiments are indispensable in the investigation of the toxicity of drugs on cells, but may not be preferred for ethical reasons and sensitivity. As an alternative procedure, we investigated the susceptibility of cells to drugs using the effect on cellular respiration as an indicator of cell activity (toxicity). The primary cultures (cell lines) used in this study included human fetal myocardial cells, skeletal muscle cells, nerve cells, hypophyseal cells, epithelial cells of gastric mucosa, lymphocytes, hepatocytes, pancreatic (exocrine) cells, renal tubular epithelial cells and fetal adrenal cortex cells, which were obtained from the American Type Culture Collection (ATCC). The drugs used were diazepam, haloperidol and levomepromazine maleate (psychoactive drugs), cisplatin and doxorubicin hydrochloride (anticancer agents). The cells were used at a density of 2 x 10(6) cells/2 mL of growth medium and, to test the susceptibility, each drug was prepared at a concentration of 10 g/mL. Experiment results indicated that, even with the same drug, sensitivity was markedly different depending on the cell lines. Cardiac muscle cells showed the strongest respiratory inhibition by Serenace and were least inhibited by Hirnamin. The highest sensitivity to Cercine was noted for neurons, while gastric mucosa cells had almost no sensitivity. Sensitivity to Serenace, which was expected to have a strong nerve action, was higher in myocardial cells instead. In the present study, we suggested the possibility of studying individual differences in drug sensitivity through investigation of toxicity in each organ as opposed to toxicity in the individual. In addition, Serenace, which was developed as a neurotopic agent, showed a higher toxicity in cardiac muscle cells than in neurons. This finding appeared noteworthy, not only for forensic toxicology, but also for clinical practice and drug development.

Cell Count↗

Renal adenocarcinoma in a ferret.

A spontaneous case of renal tumor was observed in a 7-year-old ovariectomized female pet ferret (Mustela putorius furo). Clinical signs included exhaustion, emaciation, anorexia, and stooping position. At necropsy, a solid and cystic mass replaced the left kidney and adrenal gland. The tumor was composed of pleomorphic epithelial cells with a large number of giant cells. Metastases were recognized in the lung, liver, greater omentum, right renal pelvis, and systemic lymph nodes. Immunohistochemical stains revealed that the tumor cells were positive for CD10, cytokeratin (CAM 5.2), and Ki-67 (MIB-1). On the basis of morphologic and immunohistochemical features, the tumor was diagnosed as a pleomorphic renal adenocarcinoma. This type of neoplasm is very rare in all species and has never been reported in a ferret.

Adenocarcinoma↗

[Pulmonary embolectomy for acute massive pulmonary thromboembolism after failure of thrombolytic therapy].

Acute massive pulmonary thromboembolism (PTE) is associated with an exceptionally high mortality rate and results in death if not diagnosed early and treated properly. We observed 3 cases of acute massive PTE. One of the patients had undergone a surgery for femoral neck fracture. Ten days postoperatively, she developed severe dyspnea with hypoxia, and computed tomography (CT) pulmonary angiography confirmed the PTE diagnosis. She then had cardiac arrest when catheter examination. Although emergency surgical thrombectomy was successful with good postoperative hemodynamic stability and oxygenation, the patient did not recover from the unconsciousness caused by preoperative ischemic brain damage. Subsequently, she died 6 months after surgery. Of the 3 patients, 2 suffered from right ventricular dysfunction without hemodynamic instability. They underwent open thrombectomy after the failure of conservative treatment with a systemic injection of urokinase. Both patients demonstrated a good clinical course and were discharged from hospital in a good general condition 22 and 28 days postoperatively. Herein, we review the current literature on PTE treatment. We concluded that an aggressive surgical intervention might be preferred to thrombolytic therapy for PTE patients with massive thrombosis and progressive right ventricular dysfunction.

Acute Disease↗

[Thoracoscopic repair of peritoneopleual communication with a giant diaphragmatic bullae in a patient with liver cirrhosis; report of a case].

Hepatic hydrothorax is defined as pleural effusion in patients with a cirrhotic liver. The pleural effusion occurs due to ascites flowing to the pleural cavity through a diaphragmatic communication. Recent literature has described the usefulness of a thoracoscopic repair and has shown that it can control pleural effusion very efficaciously. The patient was a 65-year-old woman who complained of dyspnea and was admitted to our hospital. A chest X-ray revealed marked right pleural effusion. We injected indigo carmine intraperitoneally and observed indigo carmine-colored pleural effusion; thus peritoneopleural communication was validated. After the failure of thoracic drainage and pleurodesis with minocycline hydrochloride, thoracoscopic surgery was performed 5 weeks after hospitalization. Obvious bulla formation was observed on the diaphragm, which was immediately resected with linear staplers. The postoperative course was excellent without any recurrence of pleural effusion.

Aged↗

Enhancement of crude bone morphogenetic protein-induced new bone formation and normalization of endochondral ossification by bisphosphonate treatment in osteoprotegerin-deficient mice.

Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor receptor family which plays a crucial role in negative regulation of osteoclastic bone resorption. We investigated both the quantity and quality of heterotopic new bone induced by crude bone morphogenetic protein (BMP) as a means of examining bone metabolism by bisphosphonate administration in OPG-/- mice. Four weeks after implantation of crude BMP, the volume of heterotopic new bone in OPG-/- mice without alendronate was significantly less than in wild-type (WT) mice. Alendronate treatment of OPG-/- mice resulted in enhancement of the volume of heterotopic new bone. Histological findings revealed that WT mice showed normal bone formation with persistent cartilage that was interspersed with islands of bone. In contrast, the cartilage was replaced by trabecular bone and bone marrow adipocytes in OPG-/- mice without alendronate. However, some cartilage was still present in OPG-/- mice with alendronate compared to those without alendronate. All bone formation-related parameters and bone resorption-related parameters were significantly lower in OPG-/- mice with alendronate than in those without alendronate. These findings suggest that in stimulated osteoclastogenesis without OPG, osteoinductive activity induced by crude BMP is inhibited and endochondral ossification induced by crude BMP is accelerated. On the other hand, alendronate treatment of OPG-/- mice caused osteoinductive activity induced by crude BMP to increase and endochondral ossification induced by crude BMP to be decelerated. In conclusion, inhibition of stimulated osteoclastogenesis results in the enhancement of new bone formation and normalization of endochondral ossification.

Alendronate↗

Microwave manipulation of an atomic electron in a classical orbit.

Although an atom is a manifestly quantum mechanical system, the electron in an atom can be made to move in a classical orbit almost indefinitely if it is exposed to a weak microwave field oscillating at its orbital frequency. The field effectively tethers the electron, phase-locking its motion to the oscillating microwave field. By exploiting this phase-locking, we have sped up or slowed down the orbital motion of the electron in excited lithium atoms by increasing or decreasing the microwave frequency between 13 and 19 gigahertz; the binding energy and orbital size change concurrently.

Journal Article↗

Heparan sulfate levels in mucopolysaccharidoses and mucolipidoses.

Glycosaminoglycans are accumulated in both mucopolysaccharidoses (MPS) and mucolipidoses (ML). MPS I, II, III and VII and ML II and ML III patients cannot properly degrade heparan sulphate (HS). In spite of the importance of HS storage in the metabolic pathway in these diseases, blood and urine HS levels have not been determined systematically using a simple and economical method. Using a new ELISA method using anti-HS antibodies, HS concentrations in blood and urine were determined in MPS and ML II and ML III patients. HS concentrations were determined in 156 plasma samples from MPS I (n = 23), MPS II (n = 26), MPS III (n = 24), MPS IV (n = 62), MPS VI (n = 5), MPS VII (n = 5), ML II (n = 8) and ML III (n = 3), and 205 urine samples from MPS I (n = 33), MPS II (n = 33), MPS III (n = 30), MPS IV (n = 82), MPS VI (n = 7), MPS VII (n = 9), ML II (n = 8) and ML III (n = 3). The ELISA method used monoclonal antibodies against HS. MPS I, II, III and VII and ML II and III patients had significant elevation in plasma HS, compared to the age-matched controls (p < 0.0001). Eighty-three out of 89 (93.3%) of individual values in the above MPS types and ML were above the mean +2SD of the controls. In urine samples, 75% of individual values in patients with those types were above the mean +2SD of the controls. In contrast to the previous understanding of the HS metabolic pathway, plasma HS levels in all five MPS VI and 15% of MPS IV patients were elevated above the mean +2SD of the controls. These findings suggest that HS concentration determined by ELISA, especially in plasma, could be a helpful marker for detection of the most severe MPS I, II, III, VI and VII and ML II, distinguishing them from normal populations.

Adolescent↗

Keratan sulphate levels in mucopolysaccharidoses and mucolipidoses.

The mucopolysaccharidoses (MPS) is characterized by accumulation of glycosaminoglycans (GAGs), and mucolipidosis (ML) by accumulation of GAGs and sphingolipids. Each type of MPS accumulates specific GAGs. The lysosomal enzymes N-acetylgalactosamine-6-sulphate sulphatase and beta-galactosidase involve the stepwise degradation of keratan sulphate (KS). Deficiency of these enzymes results in elevation of KS levels in the body fluids and in tissues, leading to MPS IV disease. In this study, we evaluated blood and urine KS levels in types of MPS and ML other than MPS IV. Eighty-five plasma samples came from MPS I (n = 18), MPS II (n = 28), MPS III (n = 20), MPS VI (n = 3), MPS VII (n = 5) and ML (n = 11) patients while 127 urine samples came from MPS I (n = 34), MPS II (n = 34), MPS III (n = 32), MPS VI (n = 7), MPS VII (n = 9) and ML (n = 11) patients. KS levels were determined using the ELISA method. Plasma KS levels varied with age in both control and patient populations. In all age groups, the mean values of plasma KS in MPS and ML patients were significantly higher than those in the age-matched controls. Plasma KS values in four newborn patients were above the mean + 2SD of the age-matched controls (mean, 41 ng/ml). Overall, 85.9% of individual values in non-type IV MPS and ML patients were above the mean + 2SD of the age-matched controls. For urine KS levels, 24.4% of individual values in patients were above the mean + 2SD of the age-matched controls. In conclusion, KS in blood is elevated in each type of non-type IV MPS examined, in contrast to the conventional understanding. This finding suggests that measurement of KS level provides a new diagnostic biomarker in a wide variety of mucopolysaccharidoses and mucolipidoses in addition to MPS IV.

Adolescent↗

Protective effect of a radical scavenger, MCI-186 on islet cell damages induced by oxidative stress.

Oxidative stress generated during islet isolation and transplantation causes islet cell damage. These oxidative injuries are mediated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). MCI-186 is an antioxidant used for clinical treatment of cerebral infarction in Japan. We examined a possible protective effect of MCI-186 on islet cells against oxidative stress. Islets isolated from Sprague-Dawley rats by collagenase P digestion were purified by density gradient centrifugation with Ficoll. Islets were treated with hydrogen peroxide (H(2)O(2); 5 to 250 micromol) in the presence or absence of MCI-186. Cell death was measured by an LDH release assay. Maximum islet cell death was observed at 250 micromol of H(2)O(2). MCI-186 inhibited islet cell death in a dose-dependent manner with significant reduction above 30 micromol. From the results observed we suggest that the antioxidant effects of MCI-186 may prove beneficial to improve the preservation of islet cells.

Animals↗