Biomedical subjects
Publications and source records attributed to Y Nagata.
Sialolithiasis in children is rare. Four cases of sialolithiasis in the submandibular gland occurring in children < or = 10 years old are reported. True and distal oblique occlusal radiographs were found to be useful for detection of the sialolith. A review of the literature on sialolithiasis in children is presented.
Japanese salt intake is calculated through the Food Composition Table in the National Nutrition Survey, whereas English salt intake is through urinary sodium excretion in 24 h. This study is a comparison of salt intake between Japan and England. As different measuring methods were used in both National Nutrition Surveys, we recalculated using the same measuring method. Seven Japanese young women's sodium intakes were calculated through the Food Composition Table, and the amounts of their urinary-excreted sodium were measured. These quantities were compared, and a coefficient (87.7%) was obtained. The Japanese young women's salt intake was 9.74 g/day from the Japanese National Nutrition Survey, and the coefficient was multiplied by 8.51 g/day. While comparing these experimental results with English data in 1992, the English salt intake converted from sodium intake of 3,040 mg/day was 7.72 g, 0.79g/day lower than the Japanese salt intake.
The effects of calcium gluconate on the utilization of magnesium and nephrocalcinosis in male Wistar rats made magnesium-deficient by adding excess dietary phosphorus (1.195 g of phosphorus/100 g of diet) and calcium (1.04 g of calcium/100 g of diet) were compared with the effects of calcium carbonate. The effects of dietary magnesium concentration on the magnesium status and nephrocalcinosis were also examined. Adding excess dietary phosphorus and calcium decreased the apparent magnesium absorption ratios and the concentrations of magnesium in the serum and femur and increased the deposition of calcium in the kidney, and the low magnesium condition (0.024 g of magnesium/100 g of diet) aggravated the deposition of calcium and the low magnesium status. The apparent magnesium absorption ratios and femur magnesium concentration in the rats fed a calcium gluconate diet (an equimolar mixture of calcium gluconate and calcium carbonate was used as a source of calcium) were significantly higher than in the rats fed a calcium carbonate diet (only calcium carbonate was used as a source of calcium), irrespective of dietary magnesium concentration. Dietary calcium gluconate lessened the accumulation of calcium in the kidney and increased the serum magnesium concentration compared with dietary calcium carbonate, when the rats were fed the normal magnesium diet (0.049 g of magnesium/100 g of diet) but not the low magnesium diet. We speculate that the increased utilization of magnesium by feeding the calcium gluconate diet to a limited extent prevented the low magnesium status and the severity of nephrocalcinosis caused by adding excess dietary phosphorus and calcium.
It is widely known that hypomagnesemia is one of the symptoms observed in diabetic patients. This study was performed to assess the effect of chronic magnesium (Mg) deficiency on glucose metabolism in rats. Male Sprague-Dawley rats (at the age of four weeks) were given a Mg-deficient diet or a control diet for two to eight weeks. The rats were orally administered sucrose solution (2 g/kg BW) every two weeks, and blood was drawn from a tail vein before and 15 min after sucrose loading to determine the concentrations of blood glucose and plasma insulin. At the same time, other rats in a non-fasted condition were sacrificed by decapitation (rats sacrificed at eight weeks were rats used for sucrose loading). The epididymal fat pads were immediately removed and adipocytes were isolated. The amount of glucose transporter 4 (GLUT4) in the plasma membranes and low-density microsomal membranes prepared from the adipocytes was measured by immunoblotting to estimate the influence of chronic Mg deficiency on glucose metabolism at the cellular level. In addition, plasma biochemical parameters and muscle mineral contents were also evaluated. The glucose concentration in fasted blood was significantly lower in Mg-deficient rats than in control rats throughout the experiment period. The feeding of a Mg-deficient diet also attenuated the response of blood glucose and plasma insulin: the glucose level in blood tended to be lower in Mg-deficient rats at 15 min after oral sucrose administration, and the difference was significant at two and eight weeks. The plasma insulin level in Mg-deficient rats was also lower, reaching a significant difference at two weeks. When animals were sacrificed in a non-fasted condition at 2-week intervals, the plasma glucose level was also significantly decreased in Mg-deficient rats as compared to control rats throughout the experiment period. The plasma insulin level in non-fasted Mg-deficient rats was also significantly decreased at two and six weeks. The Mg-deficient diet increased plasma triglyceride, but the difference was significant only at four weeks, and plasma cholesterol remained unchanged. The plasma Mg level was markedly lower in Mg-deficient rats throughout the experiment period. In Mg-deficient rats, the Mg content in muscle was significantly reduced at two and eight weeks, whereas the calcium and sodium contents were significantly increased throughout the experiment period. In Mg-deficient rats, the degree of translocation of GLUT4 to plasma membranes in the adipocytes stimulated by insulin was reduced only at eight weeks. In conclusion, since fasted and non-fasted blood glucose levels and the response of blood glucose to sucrose loading were decreased in Mg-deficient rats, it is suggested that Mg deficiency induces changes in the glucose metabolism via impaired glucose absorption in the intestine or an altered glucose uptake in the liver and/or peripheral tissues.
UNLABELLED: Transplanted VX2 liver tumor in the rabbit is an experimental liver tumor model in which 18F-2-fluoro-2-deoxy-D-glucose (FDG) accumulates to a 3.5-fold level that surrounds normal liver tissue. In this study, changes in FDG uptake were assessed in this liver tumor model after transcatheter arterial embolization (TAE) and radiotherapy. METHODS: Fifteen rabbits bearing VX2 liver tumors were treated with TAE with gelatin sponges 1 day before the FDG study, and 18 rabbits received local irradiation with electron beams at a dose of 12-36 Gy 1-10 days before the FDG study. In the FDG study, serial arterial blood sampling was performed to determine arterial input (AI), and 1 hr after tracer injection, normal liver tissue and tumor tissue were excised to measure radioactivity. The tumor FDG level per AI and the tumor-to-normal liver ratio were assessed. Dynamic PET images were obtained in 20 of the 46 rabbits. RESULTS: Tumor FDG uptake was significantly decreased 1 day after TAE (from 3.54 to 0.83 in the tumor-to-normal liver ratio) and 5 days after 30 Gy of irradiation (from 3.54 to 1.28). The decrease in tumor FDG uptake was dose-dependent, especially in the relatively low dose range (12-24 Gy). The untreated tumors could be clearly distinguished from the surrounding normal liver tissue, while the embolized tumors or the irradiated tumors were not clearly delineated. Histological analysis showed that the decrease in tumor FDG after treatment agreed well with the decrease in number of viable tumor cells. CONCLUSION: The VX2 liver tumor is an appropriate experimental tumor model for evaluating the change in FDG uptake in various therapeutic modalities. Moreover, the therapeutic effects can be assessed 1 day after TAE and 5 days after irradiation. Further clinical trials for the early evaluation of therapeutic effects on liver tumors using FDG-PET are warranted.
Gold(III) ions in aqueous solutions of NaAuCl4 were reduced to form gold particles by ultrasonic irradiation. The rate of formation of gold particles was accelerated in the presence of certain organic additives such as surfactants, water-soluble polymers and aliphatic alcohols and ketones. The rates of formation of gold particles from 1 mM Au(III) ions in pure water were 3 microM min-1 under argon atmosphere and approximately zero under air, and in solutions containing additive the rates were 9-133 microM min-1 under argon and 8-40 microM min-1 under air. Surfactants stabilized the particles as colloidal state for more than several months. The rates of formation of both hydrogen atoms and hydroxyl radicals were estimated to be equal to 25 microM min-1 in the sonolysis of pure water under argon. Three reaction pathways leading to the reduction of metal ions were proposed: (1) reduction by hydrogen atoms; (2) reduction by reducing radicals formed via reactions of hydroxyl radicals or hydrogen atoms with the additives; (3) reduction by radicals formed from thermal reaction of the additives at the interfacial region between cavitation bubbles and bulk solution and/or in the cavities. The order of the contribution of these three pathways to the reduction of gold ions was (3) > (2) > (1) in most cases. The number averages of the size of gold particles formed in surfactant solutions under argon atmosphere were about 10 nm with a fairly narrow size distribution.
In this paper, 10 cases of acute spontaneous subdural hematoma (ASSDH) among 149 cases of all acute subdural hematoma (ASDH) were reported with a review of 36 cases in the literature. The age of the patients with ASSDH ranged from 48 to 90 years (mean age of 71.9 years), and the average age of ASDH patients was 52.4 years. The male to female ratio of ASSDH and ASDH was 3:7 and 5:2, respectively. ASSDH patients were older than ASDH patients, and ASSDH patient tended to be female. Four cases of ASSDH patients had the past history of dementia. The outcome of 5 cases of ASSDH with general complications was fatal. During operation in all cases except one, spurting arterial rupture from a branch of the cortical artery adjacent to the Sylvian fissure was observed. It was presumed in the literature that the mechanism of the arterial rupture is gliding movement of the brain, tearing an arterial twig with dural attachment, or the existence of the junction of an arterial twig as an anatomically weak point. Hypertension, alcoholism, dementia, past history of subdural hematoma or subarachnoid hemorrhage may be important influencing factors in this mechanism.
The therapeutic effects and safety of intravitreal ganciclovir injection were evaluated in 16 acquired immunodeficiency syndrome (AIDS) patients with cytomegalovirus (CMV) retinitis. The induction therapy was done in a total of 23 courses, i.e., in 14 eyes of 10 patients. Active lesions of CMV retinitis were suppressed by 3 to 7 injections over 21 to 42 days after the initiation of the induction therapy. Intravitreal injections once a week for maintenance suppressed the reactivation of the lesions for at least 6 weeks in 9 eyes of 7 patients among 10 eyes of 8 patients. As for the safety of intravitreal ganciclovir injections in the 16 AIDS patients with CMV retinitis, a total of 354 injections were given and two serious complications, that is, endophthalmitis and retinal detachment were observed in one eye each. During the course of intravitreal injection, 3 of 7 patients developed CMV retinitis in the contralateral eye and systemic CMV infections were suspected in 3 of 12 patients. Intravitreal injection of ganciclovir is thought to be effective for the treatment of CMV retinitis in AIDS patients, but careful procedure and examinations are needed.
Nonpenetrating blunt trauma causing pulmonary pseudocyst is very rare. A 25-year-old young male suffered from motor vehicle accident. He was transferred to our hospital with severe hemoptysis. Immediately he was intubated and kept under mechanical ventilation. A chest X-ray film and CT-scan revealed a marked cavity lesion surrounded by an extensive infiltrate and alveolar air consolidation. Ordinary, it has benign clinical courses by conservative management. However, he was suffered massive and continuous bleeding from endobronchial tube. Therefore, one lung ventilation using a uni-vent tube blocker was performed. After twelve hours blockade, the cavity lesion was enlarged and trans-bronchial bleeding was continued severely. Emergency right lower lobectomy was carried out successfully.
A 65-year-old male was admitted to our hospital because of bilateral giant bullae and right side pneumothorax. He had had a myocardial infarction and had been receiving medications. Considering his age, ischemic heart disease and hypertension, we excised the bullae in two operations. The first operation was open chest bullectomy of a giant bulla and small bulla on the right side. After this procedure, his clinical course was uneventful. In the second operation, thoracoscopic excision of the left side giant bulla was performed using only one endoscopic stapler by rotating each side of the bulla and making a clear excision line between the bulla and normal lung. His post operative course was excellent and he was discharged from our hospital on the 15th day after the second operation.
PURPOSE: Radiation therapy is a useful palliative modality for refractory lesions of multiple myeloma. It has been reported that total doses of 10 to 20 Gy are usually adequate to obtain some degree of pain relief. However, there are many patients who need additional doses to obtain sufficient pain relief. In this study, we retrospectively analyzed the records of patients with multiple myeloma irradiated at our department, in an attempt to develop an effective treatment policy for this disease. MATERIALS AND METHODS: Twenty-nine patients with 53 lesions were treated between 1968 and 1993. Total irradiation doses were 4 to 60 Gy(median 40 Gy) with daily fractions of 2 Gy or less, and 16 to 51 Gy(median 30 Gy) with daily fractions greater than 2 Gy. Evaluated were 59 symptoms, including pain (68%), neurological abnormalities (15%), and masses (28%). RESULTS: Symptomatic remission was obtained in 33 of 36 (92%) lesions with pain, 6 of 8(75%) with neurological abnormalities, and 13 of 15(87%) mass lesions. Pain was partially relieved at a median TDF of 34, and completely at a median TDF of 66(equivalent to 40-42 Gy with daily fractions of 2 Gy). CONCLUSIONS: Radiation therapy is an effective and palliative treatment method for symptomatic multiple myeloma. However, the treatment seems to require higher radiation doses than those reported to obtain adequate relief of symptoms.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The onset of motion was used to study stimulus-driven visual attention in 14-week-olds. The movement of an object did not capture attention reflexively at 14 weeks of age. The attention-getting properties of a moving stimulus depended significantly on its color in combination with the colors of other objects in the visual field. Specifically, detection of a green moving target was masked in the presence of mixed red and green static objects. No such masking was observed when the moving target was red or when the green target moved in a visual field that was populated only with green objects. The same effect was observed to a lesser extent when the green bars were replaced with gray bars. The number of distractors in the visual field exerted an effect on the accuracy of detection only when their appearance in the visual field was coincident with the onset of target motion. Attention to motion at this age is not independent of the structure of the visual field; chromatic preferences play a role in how readily infants attend to a moving object. These effects may be mediated by a difficulty in disengaging attention (from distractors) or in suppressing attention to competing objects once attention is engaged on a target.
Thrombopoietin (Tpo) is a cytokine regulating megakaryocyte maturation and platelet formation. We studied Tpo-induced signal transduction, and found that Tpo induces phosphorylation of adapter molecules. Shc and Vav, and of serine/threonine kinases Raf-1 and mitogen-activated protein (MAP) kinases. Further, Tpo induced activation of Ras, MAP kinase kinase, MAP kinase and Pim-1. Taken together with other observations, we concluded that Tpo induces the activation of at least two distinct signaling pathways, a specific Tyk2-JAK2/STAT1-STAT3-STAT5 signaling cascade and a common Shc/Vav/Ras/Raf-1/MAP kinase kinase/MAP kinase signaling cascade.
Chitosanase, an enzyme which hydrolyzes chitosan, isolated from Bacillus circulans MH-K1, was crystallized by a vapor-diffusion procedure at 293 K using ammonium sulfate as a precipitant. Rod-shaped colorless crystals, which grew to 0.05 x 0.15 x 1.2 mm within a week, belong to the orthorhombic system and the space group P222(1) or P2(1)2(1)2 with unit-cell dimensions of a = 43.3, b = 57.7, and c = 128.0 A. The asymmetric unit is thought to contain one chitosanase molecule (29 024 Da). The crystals diffract X-rays to at least 2.3 A resolution and are suitable for high-resolution X-ray structure analysis.
Thrombopoietin (Tpo) is a cytokine that specifically regulates megakaryocyte maturation and platelet production. Little is known about the molecular and cellular mechanism of the Tpo-induced megakaryocyte maturation process including polyploidization and platelet release. To study Tpo-induced megakaryocyte differentiation, a mouse cell line FD-TPO, which responds and grows with Tpo, was established from a interleukin-3-dependent hematopoietic progenitor cell line FDC-P2. The FD-TPO cells, expressing endogenous Tpo receptor, grew with Tpo in a dose-dependent manner. Further, Tpo stimulation dramatically induced expression of megakaryocyte/erythroid-specific transcription factors GATA-1 and NF-E2 in FD-TPO cells. Flow cytometry analysis demonstrated that expression of platelet-specific cell surface antigens including CD61 (GPIIIa) dramatically increased in Tpo-stimulated FD-TPO cells and that expression of myeloid-specific antigens, Gr-1 and Mac-1, decreased. Therefore, we concluded that the binding of Tpo to FD-TPO cells induces not only cell growth but also differentiation into mature megakaryocyte-like cells, and thus this cell line was found to be useful for the study of Tpo receptor-mediated growth and differentiation signals.
Thrombopoietin (Tpo) is a specific cytokine which regulates megakaryocyte differentiation and maturation. We isolated a truncated mouse Tpo cDNA, the product of which turned out to function neither as an active Tpo variant nor as an antagonist. To define the functional domains of the Tpo molecule further, various truncated and point-mutated Tpo molecules were prepared and their biological activity was assayed. It was found that deletion of the amino terminal side of a potential proteolytic cleavage site, Arg-Arg motif, caused complete loss of Tpo's activity, and that point-mutants lacking one of four conserved cysteine residues lost Tpo activity. We also noticed that Tpo activity was inhibited by the reducing agent. Thus, it was concluded that the amino terminal half of the Tpo is sufficient for Tpo activity, and that the cysteine residues, especially the last cysteine residue located two amino acids away from the Arg-Arg motif, are critical for this activity.