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Biomedical subjects

T Ono

Publications and source records attributed to T Ono.

At least 1,027 records · Page 57Linked to original sources

Functional analysis of a complementary DNA for the 50-kilodalton subunit of calmodulin kinase II.

The calcium-calmodulin-dependent protein kinase II is a major component of brain synaptic junctions and has been proposed to play a variety of important roles in brain function. A complementary DNA representing a portion of the smaller 50-kilodalton subunit of the rat brain enzyme has been cloned and sequenced. The calmodulin-binding region has been identified and a synthetic analog prepared that binds calmodulin with high affinity in the presence of calcium. Like the 50-kilodalton kinase polypeptide, the concentration of the messenger RNA varies both neuroanatomically and during postnatal development of the brain. The broad tissue and species cross-reactivity of the complementary DNA suggests that the 50-kilodalton subunit found in rat brain is evolutionarily conserved and is the product of a single gene.

Age Factors↗

Electrostatic interaction between retinylidene chromophore and opsin in rhodopsin studied by fluorinated rhodopsin analogues.

Photochemical reactions of fluorinated rhodopsin analogues (F-rhodopsins) prepared from 10- or 12-fluorinated retinals (10- or 12-F-retinals) and cattle opsin were investigated by means of low-temperature spectrophotometry. On irradiation with blue light at liquid nitrogen temperature (-191 degrees C), the F-rhodopsins were converted to their respective batho intermediates. On warming, they decomposed to their respective fluororetinals and cattle opsin through lumi and meta intermediates. There was a difference in photochemical behavior between batho-12-F-rhodopsin and batho-10-F-rhodopsin. Upon irradiation with red light at -191 degrees C, batho-12-F-rhodopsin was converted to a mixture of 12-F-rhodopsin and 9-cis-12-F-rhodopsin like that of the natural bathorhodopsin, whereas batho-10-F-rhodopsin was not converted to 9-cis-10-F-rhodopsin but only to 10-F-rhodopsin. This fact suggests that the fluorine substituent at the C10 position (i.e., 10-fluoro) of the retinylidene chromophore may interact with the protein moiety during the process of isomerization of the chromophore or in the state of the batho intermediate. On irradiation with blue light at -191 degrees C, 9-cis-10-F-rhodopsin was converted to another bathochromic intermediate that was different in absorption spectrum from batho-10-F-rhodopsin. 9-cis-10-F-rhodopsin was practically "photoinsensitive" at liquid helium temperature (-265 degrees C), whereas 10-F-rhodopsin was converted to a photo-steady-state mixture of 10-F-rhodopsin and batho-10-F-rhodopsin. The specific interaction between the fluorine atom at the C10 position of the retinylidene chromophore and the opsin was discussed in terms of electrostatic interactions.

Animals↗

Neuronal activity in the ventral tegmental area (VTA) during motivated bar press feeding in the monkey.

Neuronal activity of 58 dopaminergic (DA) and 200 non-dopaminergic (non-DA) neurons in the ventral tegmental area (VTA) of female monkeys was recorded, and correlation to bar press feeding, sensory stimulation and change in motivation was investigated. DA neurons, judged by duration of action potentials (more than 2.5 ms) and responsiveness to apomorphine, had lower firing rates (0-8 impulses/s); non-DA neurons had intermediate firing rates (10-30 impulses/s). Two-thirds of the DA and non-DA neurons responded in bar press feeding; the former with mostly tonic and the latter with phasic responses. Fifteen neurons (5%) responded phasically to arm extension toward the bar, 124 (excitation 88, inhibition 36, 45%) during bar press (BP), and 91 (excitation 32, inhibition 59, 33%) during ingestion reward (RW). Most BP responses (84/124, 68%) continued tonically throughout the BP period with no correlation to each BP movement. In 14 neurons (14/124, 11%), firing showed a specific variation: transient early BP responses shifted to tonic steady ones in palatable food trials, and the shifts correlated well with BP speed. In 20 other neurons, firing increased during BP hip lifting, and at specific vocalization to ask for food; it decreased during food ingestion, drinking and inguino-crural stimulation. Apomorphine administration decreased firing for the first 5-15 min, then increased it with frequent lip smacking, nausea, involuntary movement and vocalization. Thus VTA neurons showed mostly steady tonic responses but some specific phasic responses. They responded not only to motor events but also in close relation to changes of motivational aspects. Neuronal responses were excitation during procurement of reward and inhibition during or after perception of reward. This modulation in firing, might be important in the initiation and execution of movement and/or motivated behavior.

Action Potentials↗

Isolation of a biologically active low-molecular-mass chromium compound from rabbit liver.

A low-molecular-mass chromium-binding substance (LMCr), which is recognized as a detoxification ligand of chromium, was isolated from the livers of rabbits injected intravenously with K2Cr2O7 (200 mumol Cr/kg body wt) as a biologically active form. LMCr appears as an anionic, organic Cr compound with a relative molecular mass of 1500. It is composed of glutamic acid or glutamine, glycine, cysteine and aspartic acid or asparagine with a Cr/amino-terminal residue ratio of 4:1. The purified LMCr (10-300 ng Cr/ml) shows in vitro activities comparable to those of glucose tolerance factor in relation to insulin action. In the presence of insulin it enhances [U-14C]glucose conversion to 14CO (23-30% up) in rat epididymal adipocytes above the value obtained with insulin alone. LMCr also stimulates the rate of [3-3H]glucose incorporation into lipid by 30-40% with insulin or by 15-23% without insulin, as compared with the basic value obtained with insulin alone or without insulin. These findings suggest that LMCr plays essential roles in both glucose metabolism and detoxification of invaded Cr in the body.

Adipose Tissue↗

Tissue specificity of calspermin: a heat-stable Mr 32,000 calmodulin-binding protein.

We previously reported that rat testis and porcine testis contain a physicochemically indistinguishable Mr 32,000 calmodulin-binding protein, which we named "calspermin." In this study, antiserum against calspermin from porcine testis was raised in a rabbit, and a radioimmunoassay was developed. The antiserum reacted with calspermin from porcine testis but possessed little cross-reactivity against calspermin from rat testis. Among various porcine tissues, this protein was found primarily in testis, sperm, and brain. Its concentration in the cytosol was higher than that in the particular fraction in testis, but the reverse was found in brain. In brain, its concentration was highest in gray matter of cortex and in cerebellum, and became lower in tectum, white matter of cortex, hypothalamus, midbrain, and pons, in this order, and was nondetectable in medulla oblongata.

Animals↗

Clinical evaluation of total-body hyperthermia combined with anticancer chemotherapy for far-advanced miscellaneous cancer in Japan.

One hundred sixty-eight patients with miscellaneous far-advanced cancer received a total of 444 extracorporeally induced total-body hyperthermia (TBHT) treatments in seven Japanese hospitals. Overall, a regression of malignancy was observed in 39 of 132 evaluable patients (29.5%) and the most favorable results were obtained for patients with lung cancer. Irrespective of whether the tumors were primary or secondary lesions or recurrences, favorable results were obtained in patients whose tumors were in the lung, liver, lymph nodes, and soft tissue. No relationship was found between an objective response to TBHT and histologic types of the tumors. There was no clear relationship between an objective tumor response and the nature of the simultaneous chemotherapy during hyperthermia. Antitumor effects were not evaluable in 36 patients (21.4%). Of these 36 patients, 33 died before evaluation could be made; 24 died of various complications and 9 died of cachexia without complication. The mortality increased in proportion to the reduction of the performance status of patients before TBHT. These results indicate that TBHT should be used as therapy for patients whose tumors are in the lung, liver, lymph node, and soft tissue and then only on patients in generally good condition.

Adult↗

Soybean hydrophobic protein. Isolation, partial characterization and the complete primary structure.

A 9000-Mr protein isolated from a 60% ethanolic extract of soybean (Glycine max) seeds has been characterized and fully sequenced. The protein consists of 80 amino acid residues with four disulfide bonds. It contains a large number of hydrophobic residues and lacks methionine, phenylalanine, tryptophan, lysine and histidine residues. The protein readily crystallizes from water but is quite soluble in aqueous organic solvents like 95% 1-propanol. It aggregates to form large molecules (above 80 kDa) under ordinary denaturing conditions, such as 6 M guanidine X HCl and 8 M urea. Sequence analysis showed that the amino-terminal four-fifths is extremely hydrophobic and most of the acidic residues exist as their amide forms, and only the carboxyl-terminal short segment is rather hydrophilic. A computer search for homology detected an unexpected similarity of this protein to rat prolactin; however, its significance could not be assessed and this protein appears to represent a hitherto unknown protein family. Although no biochemical activity could be detected, the existence in relatively high abundance (approx. 200 mg from 1 kg seeds) of this novel protein may suggest its physiological significance in the plant.

Amino Acid Sequence↗

Immunohistochemical studies on the distribution and frequency of fatty-acid-binding protein positive cells in human fetal, newborn and adult liver tissues.

Human tissues from adult, newborn/infant, and fetal livers, and gall bladders were immunostained with rabbit antibodies against fatty-acid-binding protein (FABP) isolated from rat liver. These antibodies cross-reacted with FABP from human liver by a double immunodiffusion method. The antigenicity of FABP of human liver is well preserved in various fixatives including 10 per cent formaldehyde, 4 per cent paraformaldehyde, and Zamboni's and Bouin's solution. FABP immunoreactivities, moreover, could be detected similarly in both cryostat and paraffin sections. FABP of hepatic type was found in hepatocytes most frequently in the fetus (as early as the 7th week of gestation), moderately in the newborn/infant, and infrequently in adult liver tissues. The distribution pattern of the positive hepatocytes was uniform throughout the acini in fetuses, but periportal in adults. No immunoreactive cells were found in the gall bladder or in the extra- and intra-hepatic bile ducts. In this study, FABP was found in human hepatocytes in both fetal and postnatal livers. FABP, therefore, might be a useful marker substance in the investigation of the physiology and pathology of the human liver.

Adolescent↗

Effects of ketamine on the cholecystokinin, somatostatin, substance P, and thyrotropin releasing hormone in discrete regions of rat brain.

Intraperitoneal injection of ketamine (100 mg/kg body weight) significantly reduces the levels of cholecystokinin (CCK), somatostatin (SRIF), and substance P (SP)-like immunoreactivity in various regions of rat brain. No significant change in thyrotropin releasing hormone (TRH)-like immunoreactivity was observed. Neuropeptide systems may be involved in the neuropharmacologic effects of ketamine.

Animals↗

The effect of serum fractions on single-cell mouse embryos in vitro.

To examine the effect of various fractions of human fetal cord serum (HCS) on mouse embryos cultured in vitro, heat-inactivated HCS was separated by ultrafiltration into five distinct fractions: Fractions A, MW greater than 30,000; B, MW 30,000-10,000; C, MW 10,000-5,000; D, MW 5,000-1,000; and E, MW less than 1,000. Seven hundred twenty-eight single-cell embryos were cultured in TYH-280 medium supplemented with 8 mg/ml bovine serum albumin (BSA) and a 20% concentration of Fraction A, B, C, D, or E, whole HCS, or BSA alone. Embryos cultured with Fraction A or E or whole HCS demonstrated a significantly reduced growth rate (P less than 0.01), while embryos cultured with Fraction D demonstrated a significantly increased growth rate (P less than 0.01). Additionally, 649 single-cell embryos were cultured in medium which was supplemented with 8 mg BSA/ml and a 0, 1, 2, or 5% concentration of Fraction A or E. Fraction E displayed toxicity even at a 1% concentration (P less than 0.01), while Fraction A demonstrated growth inhibition at a 5% concentration (P less than 0.05) but increased the hatching rate at a 1% concentration (P less than 0.01). Finally, 635 single-cell embryos were cultured with four distinct fractions of HCS obtained from a Sephacryl S-200 column: Fractions I, MW 100,000; II, MW 70,000-100,000; III, MW 30,000-70,000; and IV, low molecular weight (less than 5,000).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

S-adenosyl-L-methionine facilitates recovery from deficits in delayed response and hand movement tasks following brain lesions in monkeys.

Effects of S-adenosyl-L-methionine (SAMe) on deficits in a trained delayed response task or trained hand movement tasks after lesions in bilateral dorsolateral prefrontal cortices or the hand-arm area of the unilateral motor cortex in monkeys were studied. Lesions disturbed the delayed response task or hand movement tasks moderately or severely for 1 week to several months depending on the extent of the lesion and nature of the task. Although treatment with small doses of SAMe (10 mg/kg/day, i.m.) had no effect on these disturbances, treatment with moderate doses of SAMe (20 or 30 mg/kg/day, i.m.) reduced impairments and promoted recovery from both disturbances. Pretreatment with SAMe (30 mg/kg/day, i.m.) facilitated recovery from delayed response task deficits due to administration of reserpine (0.3 mg/kg, i.m.) in monkey with bilateral prefrontal cortical lesions, but not in intact monkey. The data suggest that SAMe improves recovery from behavioral disturbances due to brain damage, and this is partly due to increased monoamine turnover rate.

Animals↗

A microcomputer aided control system for visual tracking task of monkey.

A microcomputer aided control system for visual tracking tasks is described. A video monitor displays positions of target and pointer. In a handle task, the horizontal position of a pointer is coupled to the angular position of a manipulandum. The task involves alignment and maintenance of a pointer on the target. In a bar press task, the pointer moves incrementally after each preset number of bar presses. A microcomputer and video monitor afford system flexibility, while a panel of manual switches permits the setting up of a variety of experimental conditions without extensive keyboard inputs and has the added advantage of constant display of task details. The program is written in assembly language to meet requirements for program control speed and allow timing measurement in msec. This system may be useful in the behavioral study of physiological and neurophysiological functions.

Animals↗

Interaction of polyanion against kanamycin ototoxicity.

We studied whether interference of the electron bindings between kanamycin (KM) and the outer plasma membranes of the hair cells with polyanion such as heparin can reduce ototoxicity. In a short course experiment, KM 200 mg/kg/day was injected intramuscularly 23 times with or without 1 U or 0.5 U of heparin/g/day differently to 22 guinea pigs. The reducing effect of heparin against KM ototoxicity was significant from a comparison of the N1 threshold obtained by the cochleogram. The number of surviving outer hair cells in the heparin groups was significantly greater in the third turn than in the group given KM alone. A long course experiment in which 50 injections of KM with or without 0.5 U of heparin were given intramuscularly to 16 guinea pigs revealed from the pinna reflex, cochlear microphonics and cell counting that heparin could reduce ototoxicity slightly at an early stage or before reaching crucial accumulation.

Animals↗

Osteoma in mandibular condyle.

A case of peripheral osteoma occurring in the mandibular ramus in a 26-year-old man is reported. Radiographic examination revealed a pedunculated, protruding globular, bone-like opaque mass around the notch of the right mandibular ramus. Histopathological examination showed a lamellar bone structure with irregular arrangement. Wide trabeculae, narrow interstitial areas, and many fibrovascular channels were detected by scanning electron microscopy. Thus, characteristic findings of a compact osteoma were obtained clinically and histopathologically.

Adult↗

A new material (single crystal sapphire screw) for internal fixation of the mandibular ramus.

A new single crystal sapphire bone screw which has favourable properties such as chemical stability, mechanical strength and biocompatibility, was applied for rigid internal fixation of the sagittal split osteotomies in 86 cases since 1982. Radiographic findings supported the excellent biocompatibility of the material; there was no noticeable bone loss around the screw and the excellent bone adaptation to the threaded portion was observed. The screws can mechanically support the split mandibular rami until bone union occurs. Complications due to the screw were not encountered in follow-up periods of 0.5-3.5 years.

Aluminum↗