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Biomedical subjects

J Fukushima

Publications and source records attributed to J Fukushima.

123 records · Page 7Linked to original sources
PubMed1988

Trans-activation of class II (I-A alpha) gene by I-A beta gene transfection using bovine papilloma virus as a shuttle vector system.

We have engineered a bovine papilloma virus to carry the class II MHC (A beta d) gene. The recombinant plasmid was introduced into various mouse B cell hybridomas by co-transfecting with the neomycin-resistance gene. Several transfectants which received only the beta-chain gene of I-Ad, expressed I-Ad proteins on the cell surface. Their presence was determined by direct immunofluorescence and by Northern blot hybridization as well as RNA dot blot hybridization. These I-Ad molecules could induce IL-2 production in I-Ad restricted T cell hybridomas. When I-Ad molecules are expressed on the cell surface of the transfectants, they become fully active in inducing the I-Ad restricted T cell response. The original B cell hybridomas used for transfection possessed the alpha and beta chain genes of the I-Ad molecule but there are no transcripts of these genes in the cell. We suppose that many copies of the transfected beta-chain gene or its product may also induce production of cellular alpha-chain gene products and thereby induce expression of the I-Ad molecule on the cell surface.

Animals↗
PubMed1988

Cloning and characterization of elastase structural gene from Pseudomonas aeruginosa IFO 3455.

An 8.3 Kb DNA fragment was cloned from Pseudomonas aeruginosa IFO 3455. This fragment-containing Escherichia clone, pEL2, produced a high level of elastase activity. A smaller EcoRI-KpnI fragment was subcloned into pUC118 and E. coli HB101 was transformed with the plasmid. A deletion mutant clone was also constructed in the same bacteria. These deletion mutants were tested for elastase activity and it became clear that the full length of the elastase gene was 1.0-1.3 Kb. DNA sequencing analysis revealed that this DNA fragment contains the DNA sequence coding N-terminal amino acid sequence of the elastase protein.

Amino Acid Sequence↗
PubMed1988

Disturbances of voluntary control of saccadic eye movements in schizophrenic patients.

To study whether or not schizophrenic patients have disturbances in voluntary control of saccades, we examined visually elicited saccade and antisaccade tasks in 10 normal control subjects and 12 schizophrenic patients. The latencies of saccades in the schizophrenic patients were not significantly different from those of normal controls. However, 6 of the 12 schizophrenics showed significant abnormalities in the antisaccade task; 6 made more errors and 3 of them showed longer latencies than normal controls. Five of these 6 patients revealed an atrophy of the frontal cortex on computed tomography (CT) scans. These results indicate that many schizophrenics show difficulties in voluntary control of saccades, suggesting a dysfunction of the frontal cortex.

Adult↗
PubMed1988

Head tilt produced by hemilabyrinthectomy does not depend on the direct vestibulospinal tracts.

Head tilt is one of the most characteristic and enduring symptoms produced by hemilabyrinthectomy and is compensated by the central nervous system with time. In order to study the central mechanisms of compensation of the head tilt, it is first necessary to understand how it is produced. However, its mechanism remains unknown. Experiments were performed in cats to examine whether the direct vestibulocollic pathways are responsible for the head tilt, as suggested by some authors. Hemilabyrinthectomies produced a characteristic head tilt in cats in which the medial and/or one lateral vestibulospinal tracts (VSTs) had been interrupted. The lesions of the medial VST did not influence the preexisting head tilt produced by hemilabyrinthectomies. These results suggest that the head tilt produced by hemilabyrinthectomies does not depend on the activity of the VSTs.

Animals↗
PubMed1987

The pathways responsible for the characteristic head posture produced by lesions of the interstitial nucleus of Cajal in the cat.

(1) Experiments were performed in cats to examine effects of lesion of the interstitial nucleus of Cajal (INC) on head posture and the responsible pathway. Unilateral INC lesions resulted in lateral tilt of the head to the opposite side, and bilateral INC lesions resulted in dorsiflexion of the head as reported earlier. Such characteristic head posture was produced by successful kainic acid injections as well as by electrolytic lesions, suggesting that it was not due to damage of nerve fibers passing through the INC, but was produced most probably by damage of nerve cells in the INC. Electromyographic (EMG) recordings in unilateral INC-lesioned cats showed that activity was higher in the ipsilateral than in the contralateral major dorsal neck muscles (biventer, splenius, complexus, and rectus), and also higher in the contralateral than in the ipsilateral obliquus capitis caudalis muscle. The pattern of EMG activity was basically similar either when the cats presented typical head tilt or when their head was fixed to the frame at the stereotaxic plane. Characteristic head posture resulting from INC lesions seems consistent with the head posture produced by activation of these muscles. (2) Interruption of the medial and lateral vestibulospinal tracts did not significantly influence head tilt that had been produced by INC lesions. Characteristic head tilt was produced by INC lesions after cats had received bilateral labyrinthectomies, bilateral lesions of most of the vestibular nuclei, and bilateral aspiration of the cerebellar vermis and most of the lateral vestibular nuclei, indicating that typical head tilt can be produced without the vestibular nuclei and cerebellar vermis. (3) The medial longitudinal fasciculus (MLF) was interrupted at different levels to cut the major descending fibers from the INC. MLF interruption at the caudal midbrain produced typical head tilt, although MLF cut at the caudal pons and medulla was ineffective. Bilateral parasagittal cuts lateral to the MLF in the pons produced severe dorsiflexion of the head, and a subsequent unilateral INC lesion produced no further head tilt. These results suggest that fibers originating in the INC, removal of which is responsible for the typical head tilt, run through the MLF in the midbrain, and leave it in the pontine level.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Lack of suppression of the short-latency vestibulocollic reflex during active head movements in cats.

It is a general belief that the vestibulocollic reflex (VCR) is suppressed when subjects make voluntary head movements, although clear evidence is still lacking. Experiments were performed to examine whether the short-latency VCR evoked by electrical stimulation of the labyrinth is suppressed during active head turns in alert cats that were trained to make rapid horizontal head turns between the two milk feeders positioned 30 degrees left and right in front of the cats. They were also trained to hold the head near the midline to wait for milk, and the VCRs recorded from splenius muscles in these behavioral situations were compared. The short-latency VCR remained during active head turns, and its amplitude was not consistently modulated by the direction of head turns, indicating that it was not suppressed by active head turns.

Animals↗
PubMed1986

Effects of lesion of the interstitial nucleus of Cajal on vestibular nuclear neurons activated by vertical vestibular stimulation.

Experiments were performed in cats anesthetized with nitrous oxide to study the effects of INC lesions on responses of vestibular nuclear neurons during sinusoidal rotations of the head in the vertical (pitch) plane. Responses of neurons in the INC region were recorded during pitch rotations at 0.15 Hz. A great majority of these neurons did not respond to static pitch tilts, and they seemed to respond either to anterior or to posterior semicircular canal inputs with a peak phase lag of 140 deg (re head acceleration). Responses of vestibular nuclei neurons in intact cats were recorded during pitch rotations at the same frequency (0.15 Hz). Neurons that seemed to respond to vertical semicircular canal inputs showed peak phase lags of 90 deg relative to head acceleration, whereas neurons that responded to static pitch tilts showed peak phase shifts near 0 deg. These results indicate that responses of neurons in the INC region lag those of vestibular neurons by about 50 deg, suggesting that the former neurons possess a phase-lagging (i.e. integrated) vestibular signal. Responses of vestibular neurons in cats that had received electrolytic lesions of bilateral INCs 1-2 weeks previously were recorded during pitch rotations at the same frequency (0.15 Hz). Neurons that presumably responded to vertical semicircular canal inputs showed a peak phase lag of 60 deg relative to head acceleration, a significant decrease of the phase lag compared to normal, whereas responses near 0 deg were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Basic and acidic hydrophilic residues involved in the interaction between protomers of the bovine growth hormone dimer.

Reactivity of histidine and arginine residues--as well as of carboxyl-groups--in the covalently stabilized dimer of bovine growth hormone, was studied in comparison with their reactivity in the monomeric form. Results obtained by reaction of histidine and arginine residues with ethoxyformic anhydride and cyclohexanedione, respectively, were similar for both proteins. The reactivity of two carboxyl-groups towards a soluble carbodiimide becomes impaired in the dimer, thus suggesting that their location is within the protomer interaction area.

Arginine↗
PubMed1984

[Experience with psychotropic agents Pyrethia and Contomin in the terminal care of lung cancer patients].

Among patients with lung cancer, those having PS 4 ( Performance Status 4) and cancer pain received " Pyrecon ", a psychotropic agent, consisting of promethazine hydrochloride ( Pyrethia ) and chlorpromazine hydrochloride ( Contomin ). A mixture of 125 mg of Pyrethia and 50 mg of Contomin was diluted in 500 ml of regular IV solution and given through the central vein at a rate of 20 ml/hr. Pyrecon was found to be effective in patients with severe cancer pain in whom Brompton cocktail was ineffective. Pyrecon was also effective in patients whose daily life rhythm was unsteady due to insomnia caused by anxiety or unrest. We suggest that Pyrecon is effective in the treatment of cancer pain.

Adult↗
PubMedDate not supplied

Motor cortical kindling in cats: a comparison of adult cats and kittens.

We compared the establishment of motor cortex kindling by daily electrical stimulation in adult cats and in 4-week-old kittens. All the adult cats and kittens examined reached a stable state of kindled seizures. There was no significant difference in afterdischarge (AD) thresholds, the course of clinical seizure development, or the number of stimuli required for the establishment of kindling between adult cats and kittens. During the development of the kindling stage, AD frequency increased in both adult cats and kittens, although AD duration did not show a clear change.

Aging↗
PubMedDate not supplied

Disturbances in the control of saccadic eye movement and eye-head coordination in schizophrenics.

Some schizophrenic patients have been known to have frontal cortical dysfunction. In view of the evidence that voluntary purposive eye movements and rapid head movements involve areas of the frontal cortex, investigations of saccade performance have been carried out on schizophrenics in various laboratories. We have compared performance of schizophrenic patients in tasks involving inhibition of reflexive saccades (no-saccade) and initiation of saccades without target (memory-saccade) with performance in the antisaccade task. These measures were also compared with results of eye-head coordination tasks. Schizophrenics showed more errors and significantly longer latencies, with lower peak velocities at large amplitudes, in both the antisaccade task and the memory-saccade task. Performance with coordinated eye-head movement was basically similar, except for significantly longer latencies of head movement. These results suggest that schizophrenics may have a disturbance in initiating and executing purposive saccades without targets, and that dysfunction of the frontal cortex may contribute to this disturbance.

Adolescent↗
PubMedDate not supplied

The search for a potent DNA vaccine against AIDS: the enhancement of immunogenicity by chemical and genetic adjuvants.

DNA vaccination is a new way to generate antigen specific immune responses by inoculating plasmid DNA encoding microbial genes. We believe that the use of immunologic adjuvants together with DNA vaccines is a promising way to enhance and optimize DNA-derived immunity. Various chemical and genetic adjuvants have been explored in our recent study. Data from these studies suggests that adjuvants exert their immunomodulatory properties through several mechanisms such as lymphoid cells recruitment, cytokine induction, and the facilitation of DNA entry into cells. Furthermore, each adjuvant has unique immunomodulatory effects on cell-mediated and humoral immune responses induced by DNA vaccination to human immunodeficiency virus type 1. To optimize the desirable immune response, the choice of adjuvant and decision of immunization route are important considerations. A similar approach may be useful potentiating anticancer immunotherapy as well.

AIDS Vaccines↗