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Biomedical subjects

M Kaneda

Publications and source records attributed to M Kaneda.

At least 127 records · Page 7Linked to original sources

Anatomical features associated with preaxial duplication (pd): a recessive mutation in the rat.

Preaxial polydactyly of the fore- and hindlimbs was found in Wistar-derived rats in 1978. Genetic analysis indicated that the polydactyly was due to the effects of an autosomal recessive gene (gene symbol; pd). Polydactylous homozygous rats had two or three pollices (six or seven digits) in the forelimbs and one to three preaxial extra digits (six to eight digits) in the hindlimbs. Skeletal examination revealed the presence of the extra carpal, metacarpal, and phalangeal bones that seemed to be complete or incomplete duplication of the navicular, greater multangular, first metacarpal, and phalanges of digit I in the forelimbs. In the hindlimbs, extra tarsal, metatarsal, and phalangeal bones were also observed preaxially. These extra elements seemed to be mirror-image duplications of the talus, navicular, second cuneiform, third cuneiform, cuboid, and metatarsals and phalanges of digits II-V with the absence of the first cuneiform, tibiale, first metatarsal, and phalanges of digit I. In addition, morphological changes were observed in the humerus, radius, and ulna in the forelimbs and femur, tibia, and fibula in the hindlimbs. Especially in the radius and tibia, thickening and bifurcation were found, indicating incomplete duplication of these bones. Based on these findings, the limb anomaly was classified as preaxial carpometacarpal/tarsometatarsal-type polydactyly with incomplete duplication of the radius and tibia. The mutant rats had other associated anomalies such as accessory spleens and cryptorchism. The males are sterile, whereas the females breed normally.

Animals↗

Effect of eicosapentaenoic acid ethyl ester on proteinuria of streptozotocin-induced diabetes mellitus in rats.

Streptozotocin (45 mg/kg) was intravenously administered to 7-week-old Wistar rats through their tail veins. After 11 days, the rats were divided into two groups. One group was fed a lipid-free diet (90%, w/w) plus lard (8%) and safflower oil (2%) for four weeks (Diet 1 group, n = 12). The other group was fed in the same way, except that safflower oil was replaced by 90% pure eicosapentaenoic acid (EPA) ethyl ester (Diet 2 group, n = 13). Twenty-four-hour urine was collected just before the diets started and during the experiment at 7-day intervals. In the second and third week, the levels of proteinuria were significantly lower in the Diet 2 group than they were in the Diet 1 group. There was no significant difference in the levels of creatinine, urea nitrogen, or lipids in plasma or in body weights between the two groups after four weeks on the diets. Because Diet 2 reduced proteinuria of diabetic rats compared to Diet 1, an EPA-rich diet may retard the development of diabetic nephropathy.

Animals↗

What confers specificity on glycine for its receptor site?

1. The structural requirements for activation of the glycine receptor were studied in isolated ventromedial hypothalamic neurones of rats by use of a 'concentration-clamp' technique under single-electrode voltage-clamp conditions. 2. alpha-Amino acids (L-alpha-alanine, and D-alpha-alanine, and L-serine), and glycine-methylester, glycine-ethylester and beta-amino acids (beta-alanine and taurine) produced a transient inward Cl- current, which was similar to that induced by glycine. 3. The responses to individual alpha- and beta-amino acids were selectively antagonized by strychnine, but were not affected by bicuculline, picrotoxin or the taurine antagonist, TAG (6-aminomethyl-3-methyl-4H,1,2,4-benzothiadiazine-1,1-dioxide hydrochloride), suggesting that alpha- and beta-amino acids activate the same glycine receptor. 4. beta-Amino acids were slightly more potent than the alpha-amino acids in causing cross-desensitization of the glycine response. 5. From the results of the structure-activity analysis of the optical isomers of alpha-alanine, serine and cysteine, a tentative structure of the glycine receptor is proposed.

Amino Acids↗

GABA-induced chloride current in rat isolated Purkinje cells.

Electrical and pharmacological properties of the gamma-aminobutyric acid (GABA)-induced current in the rat isolated cerebellar Purkinje cell bodies were studied using a concentration-jump method, which is termed as a "concentration-clamp" technique. This technique enables the rapid exchange of external solution around the neurons to be perfused internally under a voltage-clamp condition. The peak amplitude of GABA response increased sigmoidally with the increase of the concentration of GABA. The value of the GABA concentration that evokes a half-maximal response (Ka) was 5 X 10(-5) M, and the Hill coefficient was 1.8. The current-voltage relationship for the GABA response showed nonlinearity at membrane potentials more negative than -40 mV. The reversal potential of GABA-evoked current was close to the equilibrium potential of Cl- (ECl), indicating that the current elicited by GABA is carried by Cl-. Both the activation and inactivation phases of GABA-induced Cl- current (ICl) consisted of fast and slow components. These time constants in both phases decreased as the concentration of GABA increased. Strychnine and bicuculline inhibited the GABA-induced ICl in a dose-dependent manner, and the inhibition of the GABA response by bicuculline was competitive. Pentobarbital sodium augmented the GABA response and modified the inactivation phase. The augmentation of the GABA response by pentobarbital was more profound at lower concentrations of GABA and was accompanied by a change in the Hill coefficient from 2 to 1. The properties of the GABA response in cerebellar Purkinje cells were thought to be basically similar to those previously reported in other preparations.

Animals↗

Glycine-gated chloride current in acutely isolated rat hypothalamic neurons.

1. Electrical and pharmacologic properties of glycine-induced currents were investigated in single hypothalamic neurons acutely isolated from young and adult rats by the use of a "concentration-clamp" technique, which allows both internal perfusion and rapid application of an external solution under single-electrode voltage-clamp. 2. The glycine-induced current reversed at the Cl- equilibrium potential (ECl), and a 10-fold decrease of extracellular Cl- with a large impermeable anion resulted in a 53 mV shift of the glycine reversal potential (EGly). 3. Glycine-induced Cl- currents (ICl) increased sigmoidally in a concentration-dependent manner with a Kd of 9 X 10(-5) M at a Hill coefficient of 1.8. Current inactivation occurred completely at all concentrations within 10 s. EGly remained unchanged during continuous application of glycine, suggesting that the inactivation process is because of desensitization. 4. The glycine-induced conductance exhibited a striking voltage dependency at membrane potentials more negative than -50 mV and reached a steady state value when hyperpolarized beyond -110 mV. 5. Both the activation and inactivation phases of glycine-induced ICl are described by double exponential (fast and slow components) functions with the concentrations used. All four time constants decreased with increasing glycine concentration. 6. The slow time constant of the current decay induced by glycine increased with depolarization and decreased with hyperpolarization, indicating that the rate of desensitization is considerably voltage dependent. The fast decay showed little voltage dependency. 7. Recovery of the glycine response after complete desensitization consisted of two components. 8. The blockade of the glycine response by strychnine and picrotoxin was noncompetitive.

Animals↗

Autoimmune neutropenia in infancy due to anti-NA1 antibody: detection of antibody with immunofluorescence and agglutination test.

The sera from two patients with chronic neutropenia in infancy were examined for the presence of antineutrophil antibodies and their specificity against neutrophil antigen by using granulocyte indirect immunofluorescence test and microleukocyte agglutination test. In the microleukocyte agglutination test, the patients' sera reacted with neutrophils from their parents and normal unrelated donors having the neutrophil antigen NA1, but not with neutrophils from NA1- donors. After the absorption of patients' sera with NA1+ neutrophils, the antibody activity was completely abolished, resulting in the confirmation of the anti-NA1 antibody. In contrast, the granulocyte indirect immunofluorescence test showed positive reactions against both NA1+ and NA1- neutrophils, and the specificity for anti-NA1 was found in the results of the sera absorbed with NA1+ neutrophils. This suggested that the absorption experiment might be necessary to determine the specificity of the antibody for neutrophil antigen. Thus, we confirmed two cases with autoimmune neutropenia caused by anti-NA1 antibody. A combination of agglutination and immunofluorescence techniques would be recommended for investigation of neutrophil antibodies against the neutrophil-specific antigen.

Agglutination Tests↗

Comparison of the increment in plasma eicosapentaenoate concentrations by fish oil intake between young and middle-aged volunteers.

The effect of age on eicosapentaenoic acid (20:5 n-3; EPA) incorporation into plasma lipids was investigated in young volunteers (8 males, 19 +/- 1 yr) and middle-aged volunteers (6 males, 53 +/- 7 yr). They were asked to take 5.4 g fish oil per day for one week. The increment in EPA in the cholesteryl ester fraction after the supplementation was significantly greater in the middle-aged group (delta = 1.69%) than in the young group (delta = 0.44%) (p less than 0.05). The food intake analyzed for 3 consecutive days just before the supplementation revealed that the young group took more linoleate (17 vs. 10 g) than the middle-aged group. There was a significant inverse correlation between the increment in EPA in the cholesteryl ester fraction after the supplementation and daily linoleate intake among all the volunteers combined (r = -0.63, p less than 0.02). The higher increment in EPA in cholesteryl ester in the middle-aged group might be due to less intake of linoleate and not due to the difference in age itself.

Administration, Oral↗

Ectopic pancreas in the stomach presenting as an inflammatory abdominal mass.

A case of 29-yr-old woman with an ectopic pancreas in the stomach, presenting as an inflammatory mass, is presented. Physical examination revealed a tender mass in the upper abdomen. Laboratory data showed leukocytosis and an increase of ESR and CRP. A computed tomographic (CT) scan demonstrated a solid mass adjacent to the gastric antrum. Endoscopy disclosed a submucosal mass at the antrum. With a diagnosis of inflammatory mass lying near the gastric antrum, laparotomy was done. A mass 3 cm in diameter was found at the gastric antrum, and partial gastrectomy was performed. Surgical specimen showed a submucosal mass with a central umbilication. Histological examination revealed an ectopic pancreas with an abscess formation. The white cell count, ESR, and CRP returned to normal within 1 wk after surgery. From a review of the English and Japanese literature, we believe that ours is the first report of an ectopic pancreas, presenting as an inflammatory abdominal mass.

Adult↗

[Surgical treatment of lung cancer with chest wall invasion].

From 1955 through 1987, 64 cases underwent operation at Mie University Hospital for carcinoma of the lung invading the chest wall (p-T3). According to the classification by Mishina et al, the extent of tumor invasion of the chest wall was p3a-b in 63%, p3c in 18%, and p3d in 19%. Histologically, the tumors were epidermoid carcinoma in 565, adenocarcinoma in 31%, large cell carcinoma in 11%, and small cell carcinoma in 2%. The post surgical staging of N factor was N0 in 39%, N1 in 33%, and n2 in 28%. Extrapleural resection was performed in 27 cases and extended resection (en block resection of chest wall and lung) was performed in 30 cases with an operative mortality of 0%. The actuarial three-year survival rate (Kaplan-Meier method) for patients with p3d was 18.2% but three-year survival for patients with p3a-b and p3c was more than 30%. In spite of p3a-b, however, four-year survival for patients without extended resection was decreased to 11.6%. Four-year survival of patients with adenocarcinoma, epidermoid carcinoma, and large cell carcinoma was 5.9%, 28.4% and 75% respectively, lymphatic metastases reduced survival, with a three-year survival rate of 52.8% for patients with N0 disease and 8.35 for those with N2 disease. Among patients with extended resection, four-year survival for patients 60 years of age of less was 50.8%, greater than the 13.3% four-year survival for the patients more than 61 years of age. We conclude that long-term survival can be influenced by the extent of tumor invasion. In factor, histologic type, and the patient's age, and that extended resection and adjuvant therapy should be applied for treatment of lung cancer with chest wall invasion.

Adult↗

[Detection of antineutrophil antibodies in patients with neutropenia in infancy].

Antineutrophil antibodies in the sera against peripheral blood neutrophils were examined in 8 infants (2 to 12 months of age) with neutropenia (absolute neutrophil count 0 to 480/microliter). The antibodies were detected by granulocyte indirect immunofluorescence test (GIIFT) and microleukocyte agglutination test (M-LAT). Three of the 6 serum samples with chronic benign-type neutropenia reacted in both GIIFT and M-LAT. In 2 of these 3 samples, the antibody was proved to be specific to neutrophil antigen NA1 by the absorption experiment. Neither the GIIFT nor the M-LAT showed the antibody in two patients with Kostmann-type neutropenia. These results suggest that the examination of antibodies against neutrophils is essential to the evaluation of the patients with chronic benign-type neutropenia in infancy.

Agranulocytosis↗

Permeability to various cations of the voltage-dependent sodium channel of isolated rat hippocampal pyramidal neurons.

The permeability to various cations of the voltage-dependent sodium channel of isolated rat hippocampal pyramidal neurons was investigated under the voltage-clamp condition. The neurons were dispersed enzymatically and mechanically and perfused internally using a suction pipette technique. The permeability sequence, estimated from the reveral potential of the inward current was Li+ greater than Na+ greater than hydrazine+ greater than formamidine+ greater than guanidine+ greater than methylguanidine+ greater than monomethylamine+. Thus the ionic selectivity of the voltage-dependent sodium channel of rat central nervous system neurons is similar to that in the squid axon, myelinated frog nerve fiber and rat ventricle muscle.

Animals↗

Presence of cytochrome b-558 in guinea-pig alveolar macrophages-subcellular localization and relationship with NADPH oxidase.

The assignment of cytochrome b-558 as a component of the O2- (H2O2) -generating enzyme in guinea-pig alveolar macrophages was investigated. Guinea pig alveolar macrophages contained 76 pmol cytochrome b-558/mg protein, a value very similar to that of neutrophils. The rate of myristic acid-stimulated O2- generation by alveolar macrophages, calculated per cytochrome b-558, was only one-fourth that of neutrophils. An analysis of Percoll density gradient centrifugation profiles showed that the H2O2-generating activity of myristic acid-activated alveolar macrophages was concentrated in a single peak which was consistently associated with 5'-nucleotidase activity, a plasma membrane marker enzyme. A little H2O2-generating activity was seen with unactivated alveolar macrophages. Furthermore, the cytochrome b-558 of both myristic acid-activated and unactivated alveolar macrophages was also predominantly associated with 5'-nucleotidase activity and was found in trace amounts in a peak containing lysozyme activity, a marker of lysosome granules. Only about 6% of the cytochrome b-558 in plasma membranes from myristic acid-activated guinea-pig alveolar macrophages was anaerobically reduced by 0.5 mM NADPH, while under the same conditions about 30% of the heme protein of myristic acid-activated neutrophils was reduced. These results suggest two conclusions: firstly, that in both activated and unactivated alveolar macrophages, cytochrome b-558 is located in the plasma membrane, and the translocation of cytochrome b-558 does not occur during the activation of NADPH oxidase; and secondly, that a smaller part of cytochrome b-558 is associated with the activated NADPH oxidase of guinea pig alveolar macrophages compared with neutrophils.

Animals↗

Blockade of N-methyl-D-aspartate response in enzyme-treated rat hippocampal neurons.

The responses to excitatory and inhibitory amino acids have been investigated in isolated pyramidal cells from young and adult rat hippocampus using internal perfusion and 'concentration-clamp' techniques. The neurons dissociated in a purely mechanical way were sensitive to all excitatory amino acids (glutamate, kainate, quisqualate and N-methyl-D-aspartate (NMDA] and inhibitory amino acids (glycine, taurine and gamma-aminobutyric acid). The NMDA response was dramatically potentiated by adding glycine at threshold concentration (10(-6) M). The enzyme treatment of hippocampal slices selectively removed the NMDA sensitivity but did not alter all other pharmacological properties of voltage- and agonist-gated ion channels.

Animals↗

Pancreatic pseudocyst involving the spleen.

Pancreatic pseudocyst involving the spleen in a 52-year-old man is reported, with review of the literature. Physical examination and laboratory data revealed no specific abnormalities. A CT scan demonstrated multiple calcifications throughout the pancreas, with a cystic mass in the tail of the pancreas involving the spleen. Endoscopic retrograde cholangiopancreatography (ERCP) revealed a dilated main pancreatic duct with a direct communication to the cyst. Distal pancreatectomy with splenectomy was performed on a diagnosis of pancreatic pseudocyst. The 10 x 9.5 x 7 cm in size cyst had no epithelial lining on its wall. The amylase level in the cystic fluid was 23424 IU/l. The literature reveals that hemorrhagic complications are common and often serious. Timely surgical intervention is advocated to reduce mortality and morbidity from complications.

Humans↗

Mechanical and enzymatic isolation of mammalian CNS neurons.

Neurons were isolated from various regions of the central nervous system (CNS), by both enzymatic and mechanical isolation. These neurons were isolated from the brains of 3-21-day-old and adult rats, guinea pigs and kittens. Particular attention was directed to the thickness of the slice, the enzymes used and the treatment time, the ionic composition, pH and buffer of the bathing medium, the pipetting of brain slices after enzyme treatment, and the preservation of the isolated cells. The isolated neurons had long dendrites with numerous branchings and a typical morphological shape: e.g. the pyramidal neurons of the rat hippocampus had apical dendrites over 250 micron long; those of the rat neocortex had apical dendrites longer than 300 micron; the Purkinje cells of the rat and kitten also maintained dendrites with fifth branchings. All isolated neurons had well-preserved electrical and chemical membrane properties of the voltage-dependent channels and the receptor-ionophore complexes respectively, even after the enzyme treatment. Thus, these isolated CNS neurons having a well-preserved morphological state can be used extensively for electrophysiological and pharmacological studies on voltage-dependent and drug-gated ionic channels.

Animals↗

Carbazomycins G and H, novel carbazomycin-congeners containing a quinol moiety.

Carbazomycins G (I) and H (II), new congeners of the carbazomycin complex, have been isolated from the culture broth of Streptoverticillium ehimense. They have proved to contain a unique quinol moiety in the molecule. Their structures have been elucidated by mass and NMR spectrometries and X-ray crystallographic analysis. Carbazomycin G showed moderate antifungal activity against Trichophyton species.

Anti-Bacterial Agents↗