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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 739 records · Page 41Linked to original sources
PubMed1993

Formation of Charcot-Leyden crystals by human basophils in sputum and peripheral blood.

To confirm the formation of Charcot-Leyden crystals (CLC) in basophils, we observed basophils in sputum and peripheral blood. Sealed slide and suspension culture methods were used to observe the process of CLC formation in peripheral blood basophils and eosinophils under electron microscopy. CLC formation was observed in basophils and eosinophils, and was found to be augmented by sealed slide method. A temperature of 4 degrees C was better than 37 degrees C for promoting the formation of crystals. There was no correlation between the degranulation of these cells and the formation of CLC after stimulation with anti-IgE or anti-IgG antibodies. CLC were initially detected in the cytoplasmic granules of basophils where they continued to enlarge. No CLC were identified in mast cells under any conditions studied. These findings confirm that CLC in sputum are not exclusive to eosinophils and that CLC appear to be present in basophil-rich sites under the cell damage.

Asthma↗
PubMed1993

Toxicity of polyoxyethylene hydrogenated castor oil 60 (HCO-60) in experimental animals.

HCO-60, a polyoxyethylene castor oil derivative, is used as a solubilizer in the injectable formulations of lipophilic agents. This study was performed to examine the toxicity of HCO-60 in various experimental animals including dogs, monkeys, rabbits, guinea pigs and rats. With 1.25 or 2.5 mg/kg of HCO-60 injected i.v. to dogs, blood pressure decreased, flush, swelling and itching appeared after injection, and with 10 mg/kg of HCO-60 there was additionally a decrease of spontaneous motility. In the two higher dose groups, these symptoms paralleled an increase of histamine levels. Since degranulation was observed after injection in the mast cells of the skin, but not in the liver of dogs, the histamine in the plasma was considered to be released from the mast cells of the skin. Pretreatment with diphenhydramine, a H1-receptor antagonist, suppressed the decrease of blood pressure induced by HCO-60. These findings show that the toxicity of HCO-60 is associated with histamine release from the mast cells. No symptoms occurred in monkeys, rabbits, guinea pigs or rats with 50 or 100 mg/kg of i.v. of HCO-60, and there was no change in plasma histamine levels. This study demonstrated that the toxicity of HCO-60 is species specific to dogs among the animals tested.

Animals↗
PubMed1993

Marked increase in fundic mucosal histidine decarboxylase activity in a patient with H+,K(+)-ATPase antibody-positive autoimmune gastritis.

A 63-year-old woman was diagnosed as autoimmune gastritis by the presence of serum antibody against alpha-subunit of gastric H+,K(+)-ATPase. The patient did not have pernicious anemia, but showed achlorhydria, marked hypergastrinemia, enterochromaffin-like cell hyperplasia and an extremely high histidine decarboxylase activity in the gastric fundic mucosa. Intragastric acidification by infusion of hydrochloric acid via a nasogastric tube induced a transient reduction of serum gastrin level and fundic mucosal histidine decarboxylase activity. A marked increase in fundic mucosal histidine decarboxylase activity as well as hypergastrinemia appears to be the pathophysiologic response to achlorhydria caused by autoimmunity against gastric H+,K(+)-ATPase.

Achlorhydria↗
PubMed1993

Theoretical and experimental assessment of the kinetic properties of N-isopropyl-p-[123I]iodoamphetamine in the human brain.

The effect of the loss of radioactivity from the human brain on the measurement of regional cerebral blood flow (rCBF) using N-isopropyl-p-[123I]iodoamphetamine (IMP) was evaluated by measuring rCBF in 10 normal male volunteers from 0.5 to 30 minutes after intravenous administration. rCBF was calculated by the operational equation, which assumes no product loss. Brain tissue and arterial blood concentration data were plotted according to a multiple-time/graphic evaluation technique. Data were fitted to the kinetic three-compartment model to estimate four kinetic rate constants to evaluate activity loss from the brain. These studies showed that loss of activity from the brain is negligible during the first 5 minutes, but after 7.5 minutes the loss becomes significantly higher with time. The present study corroborates the necessity for using single photon emission computed tomographic images measured within 5 minutes of IMP injection to quantify rCBF.

Adolescent↗
PubMed1993

Basic studies on visible light-cured resin as a denture base. Part 17. Transverse and tensile strengths of repaired denture base resin using a trial repair resin.

Trial production of a visible light-cured repair resin (powder/liquid type, TPL) as a denture base resin was carried out using cyclophosphazene monomer, and then the transverse and tensile strengths of the repaired specimens were examined. As a control, Triad Gel (TRI) was used. In the transverse strength test, TPL showed values of 507-470 kgf/cm2, which were about double those of TRI. As for tensile strength, TPL showed values of 329-268 kgf/cm2, and higher values were obtained in comparison with TRI, especially after 30 days of water immersion, when the values were doubled. The durability of TPL was favorable in comparison with TRI.

Composite Resins↗
PubMed1993

[Cutaneous or subcutaneous calcinosis observed in leprosy patients. 1. Clinical observations].

A roentgenographic examination was made for the limbs of leprosy patients with calcinosis in whom atrophic cutaneous sclerosis and subcutaneous induration or infiltration were observed. The observation results are summarized as follows. 1. Atrophic cutaneous sclerosis was one of a sequela in lepromatous lesion, especially in case of ENL, and it was observed to occur frequently at the extended sides of 1/3distal part from the forearm and the crus mainly. The atrophied cutaneous surface was tinged with lustrous red. It was able to observe calcium deposition directly just under the skin and/or in the shallow subcutaneous region from the roentgenogram of the site. The roentgenographic patterns were demonstrated as if many granules were scattered, and also the dendric and reticular platy-expansions were detected in some cases. The enucleated parts seemed to be similar to the cancellous bone. It might be said that dystrophic calcinosis cutis developed by inducing histological disorder is one of the origin of such a calcinosis, because the skin in these regions is deficient in the mobility and tends to provoke the circulatory disorder in case of chronic inflammation as discerned in lepromatous lesion. 2. An induration in subcutaneous tissue is lipid lump being as it was when chaulmoogra oil was injected and not undergo absorption of the oil. The lipid lumps enveloped in the tunic were observed in the site of lateral upperarm and the front of femur. They seemed to be remained almost all as it was. It was observed that the lipid lumps, as such, were adjacent to the outer layer of fascia, but not in the muscle. And there are some cases where the oil flowed from the injection site through the hypodermis and got the lipid lumps formed in the forearm and/or the crus. Roentgenogram of that showed the existence of calcinosis regardless of size which transmissivity of X-ray had an irregular pattern. The enucleated lipid lumps were easily cut to pieces by scalpel. 3. It may be said that the calcinosis observed in atrophic cutaneous sclerosis due to lepromatous lesion or lipid lump of unabsorbed chaulmoogra oil makes it necessary for its healing to be 10-20 years. 4. Roentgenogram at that time revealed no abnormality as to serum calcium, phosphorous and/or alkaline phosphatase values.

Adult↗
PubMed1993

Expression of c-kit mRNA and protein during the differentiation of human hematopoietic progenitor cells.

To investigate how c-kit and c-kit ligand play a role in the function of hematopoietic stem cells, we determined the expression of c-kit in sorted human hematopoietic stem cells, CD34+CD33- cells and CD34+CD33+ cells. CD34+ cells constituted approximately 1% of the population of gated bone marrow cells and contained colony-forming cells. Two-color analysis by a fluorescence-activated cell sorter (FACS) revealed that about one-third to one-half of the total CD34+ cell population were positive for the CD33 antigen. To analyze the relative accumulation of c-kit mRNA in sorted cells, we used the reverse transcription-polymerase chain reaction (RT-PCR) method, followed by Southern blot analysis. There was a linear relationship between the amount of input RNA and products amplified in the range of 10(3) to 10(5) cells. Using this procedure, we carried out an analysis of c-kit mRNA expression in CD34+CD33-, CD34+CD33+, CD34-CD33+, and CD34-CD33- cells. Enhanced expression for c-kit mRNA was observed solely in CD34+CD33- cells. In contrast, flow cytometry shows that c-kit protein was expressed most abundantly in CD34+CD33+ cells. Colony-forming cells were generated on a human stromal cell layer for 5 weeks initiated with CD34+CD33- cells but not with CD34+CD33+ cells. During co-culture with stromal cells, CD34+CD33- cells differentiated into CD34+CD33+ cells. From these findings, it is concluded that CD34+CD33+ cells are direct progenies of CD34+CD33- cells. In this differentiation pathway, the expression of c-kit mRNA decreased and the c-kit protein increased.

Animals↗
PubMed1993

[Projects in surgery for lung transplantation].

Lung transplantation was simulated in 9 essential items in the surgical side. The possibility to utilize cardiac death donor instead of cerebral death donor was discussed. The transplant window was shown in a patient with primary pulmonary hypertension. The informed consent must be authorized at the specific meeting. For the pre- and postoperative care, it is essential for surgeon to treat on the team which is consisted of members from the specific regions. With donation, a method of the standardization for graft preservation was shown by statistical analysis of many factors. The level of surgical techniques in Japan have been evaluated to be on the current level. In postoperative care, reimplantation response, infection, and rejection are important factors which have been clinically overcome in preceding institutions. However, a practical method of established diagnosis for acute rejection remain unresolved. In addition, CMV infection will be an unavoidable problem in Japan. The research of immune tolerance has been successfully underwent in experiments to overcome chronic rejection.

Humans↗
PubMed1993

Cerebral metabolism and function during normothermic retrograde cerebral perfusion.

Retrograde cerebral perfusion through a superior vena cava (SVC) cannula is a new technique used to protect the brain during circulatory arrest. Cerebral blood flow, oxygen consumption, blood sugar consumption and auditory brain stem responses were measured at various rates (100, 200 and 300 ml min-1) of retrograde cerebral perfusion in normothermic mongrel dogs (n = 12, body-weight 13-15 kg). During perfusion about 20% of the perfusate from the SVC was returned via the aorta, while the rest drained into the inferior vena cava. External jugular venous pressure increased as the perfusion rate increased (mean(s.d.) 26.0(6.4) mmHg at a rate of perfusion of 300 ml min-1). Oxygen and blood sugar consumption also increased as the rate of perfusion increased. Retrograde cerebral perfusion at 300 ml min-1 provided half of the cerebral blood flow (mean(s.d.) 14.7(6.4) versus 34.3(7.8)ml min-1) of antegrade cardiopulmonary bypass (CPB). Analysis of the blood returned through the aorta during perfusion at a rate of 300 ml min-1 showed that mean(s.d.) oxygen consumption was about one-third (4.4(2.1) versus 12.3(7.1) ml min-1) and blood sugar consumption about 15% (17(22) versus 114(54)mg min-1) of that seen in blood returned through the SVC during CPB. Auditory brain stem responses disappeared immediately when perfusion was started but recovered completely as soon as CPB was resumed. Although the oxygen provided by perfusion was not sufficient to maintain cerebral function, it should help protect the brain during circulatory arrest.

Animals↗
PubMed1993

Involvement of peanut agglutinin-binding sugar chains in experimental metastasis of B16 melanoma cells.

Involvement of PNA (peanut agglutinin)-binding sugar chains in experimental metastasis of B16M4 cells and their metastatic variants (B16F1, B16F10, and B16BL6) was investigated by using ginsenoside Rh2 (Rh2), which increased PNA binding to the cell surface without increasing concanavalin A or wheat germ agglutinin binding. The PNA binding to cell surface increased in parallel with the experimental metastatic ability in Rh2-treated B16M4 cells, and this increase in metastatic ability was suppressed when the cells were treated with PNA before i.v. injection of cells. Concanavalin A and wheat germ agglutinin did not have such inhibitory effects. Increased PNA binding was observed on glycoproteins of M(r) 75,000-85,000, and was suggested to be due to reduced sialylation of PNA-binding sugar chains on these glycoproteins. In Rh2-treated B16F10 and B16BL6 cells, the increase in experimental metastatic ability was also associated with increased PNA binding to cell surface and M(r) 75,000-85,000 glycoproteins. Although the mechanisms of these effects of Rh2 are unknown, these results suggested that the reduced sialylation of PNA-binding sugar chains on M(r) 75,000-85,000 is related to the increased experimental metastatic ability of Rh2-treated B16 melanoma cells.

Animals↗
PubMed1993

Nafamostat mesilate reduces blood loss during open heart surgery.

BACKGROUND: Nafamostat mesilate (FUT-175) is a protease inhibitor inactivating coagulation, fibrinolysis, and platelet aggregation. A prospective, randomized trial was performed to assess the efficacy of FUT-175 in the reduction of postoperative bleeding tendency. METHODS AND RESULTS: FUT-175 was infused at a rate of 40 mg/h during cardiopulmonary bypass (CPB) along with 300 IU/kg of heparin in 20 patients undergoing aortocoronary bypass surgery (FUT group). This group was compared with another group of 20 patients undergoing aortocoronary bypass surgery, who were given only heparin (control group). Blood concentrations of FUT-175 and activated clotting time increased after cooling, peaking at 2050 +/- 1190 ng/mL and 2136 +/- 983 seconds at the lowest temperature and recovered after rewarming to values of 166 +/- 118 ng/mL and 510 +/- 148 seconds, respectively, at the end of CPB. In the FUT group, platelet counts were significantly higher at the end of CPB than those in the control group (168 +/- 10 versus 136 +/- 9 x 10(3)/mm3, P < .05). In the FUT group, serum concentrations of beta-thromboglobulin (307 +/- 102 versus 537 +/- 391 ng/mL, P < .05), PIC (3.6 +/- 1.7 versus 5.8 +/- 3.8 micrograms/mL, P < .05) and FDP (20.2 +/- 7.0 versus 41.4 +/- 11.9 ng/mL, P < .01) were significantly lower than those in the control group at the end of CPB. However, serum concentrations of TAT, FPA, and FPB beta 15-42 showed no significant differences between groups. FUT-175 significantly reduced heparin dosage and 24-hour postoperative blood loss (19,200 +/- 3200 versus 29,100 +/- 7700 IU, P < .01, and 382 +/- 129 versus 576 +/- 375 mL, P < .05). CONCLUSIONS: FUT-175 inhibits fibrinolysis and preserves platelet counts and function during CPB and reduces blood loss during open heart surgery.

Benzamidines↗
PubMed1993

[Biosensors comprising DNA as receptive component].

Most of biosensors rely on proteins, including enzymes and antibodies. In addition to such proteins, DNA is also an important host molecule in biological recognition. Sensors comprising DNA, single and/or double strands, as a receptive component would be useful in detecting complimentary DNA as well as DNA-binding molecules and ions. In this article, coupling methods for DNA with solid substrates are discussed. New strategies for detecting the interaction of analytes with the immobilized DNA are reviewed. The DNA duplex modified electrode is proposed to have a potential for determining binding constants of a series of DNA-binding drugs.

Animals↗
PubMed1993

[A case of intraventricular cystic meningioma].

We report a case of intraventricular cystic meningioma in the left lateral ventricle. A-44-year-old male patient was admitted with headache on November 25, 1991. Neurological examination revealed acalculia and left homonymous hemianopsia. CT and MRI showed a solid tumor which originated in the body of the left lateral ventricle, and which was associated with a cystic component postero-laterally. Tumor strains fed by the left anterior choroidal artery and the medial and lateral posterior choroidal artery by angiography. The tumor was totally removed via the lateral temporal parietal approach. Histological examination revealed meningotheliomatous meningioma in the solid tumor and only gliosis in the wall of the cyst.

Adult↗
PubMed1993

[Analyses of ventricular arrhythmias in patients with progressive systemic scleroderma (PSS) by ambulatory electrocardiography].

Disorder of cardiac conduction and automaticity have been widely reported in patients with progressive systemic scleroderma (PSS). In the present study, ventricular arrhythmias were monitored by 24-hour ambulatory electrocardiographic recording (Holter monitor) in 30 female patients with PSS and 20 apparently healthy female controls. The following results were obtained: 1) In the waking state, 8 cases of 30 patients showed grade III, IVA or IVB of ventricular arrhythmias, according to Lown's classification. On the other hand, ventricular arrhythmias, such as grade III, IVA or IVB, were not observed in the control group. 2) In the patient group, grade IVA arrhythmias were observed during defecation, driving or light working, and grade IVB were during defecation, urination, light working or sleeping. These results suggest that it is important to examine arrhythmias by Holter monitors in patients with PSS.

Adult↗
PubMed1993

[Comparison of high-pass resolution perimetry and differential light sensitivity perimetry in glaucoma patients].

High-pass resolution perimetry (HRP) enables one to estimate the number of functioning retinal ganglion-cells. We investigated the correlation between HRP and Humphrey Field Analyzer 630 in 35 eyes of 23 primary open-angle glaucoma and 75 eyes of 46 normal-tension glaucoma patients. In a total of 110 eyes, both functional channels and global deviation of HRP were significantly correlated with MD (r = 0.74, p < 0.01: r = -0.71, p < 0.01, respectively). Local deviation of HRP was also significantly correlated with corrected pattern standard deviation (r = 0.77, p < 0.01). These correlations tended to be higher in eyes with more advanced field changes than in those with fewer changes. These results indicate that HRP may be useful for evaluation of glaucomatous visual field abnormalities. The observed discrepancies between the two different methods in early stage glaucoma may be attributable to differences in physiological factors tested in these methods.

Adult↗
PubMed1993

[Treatment of recurrent laryngeal nerve paralysis by several types of nerve suture].

Although simple neurorrhaphy of the injured recurrent laryngeal nerve usually results in impaired movements of the vocal cord because of misdirected regeneration, phonation recovers because the vocal cord maintains tension during phonation. Simple neurorrhaphy is possible in only a few of patients who have had their nerve severed because of thyroid surgery for thyroid cancer. We tried free nerve grafting, vagus nerve-recurrent nerve suture and ansa cervicalis-recurrent nerve suture as well as the simple neurorrhaphy in 3, 1, 1 and 3 patients, respectively. All of the 8 patients who had repair of the recurrent nerve recovered from hoarseness. Maximum phonation times of these patients ranged from 17 to 41 sec with a mean of 26.5 +/- 9.6 sec, which were significantly longer than those of 23 patients without nerve repair. Each modality of the repair obtained similar good results, although the patient who underwent vagus-recurrent suture required a longer period for recovery. These results indicate that not only simple neurorrhaphy of the recurrent nerve but also free nerve grafting, vagus nerve-recurrent nerve suture, or ansa cervicalis-recurrent suture are effective in recovery of the phonation in patients with peripheral and unilateral recurrent nerve paralysis.

Adolescent↗