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Biomedical subjects

S Tsutsumi

Publications and source records attributed to S Tsutsumi.

At least 19 recordsLinked to original sources
PubMed1992

Activity of sparfloxacin against Mycobacterium leprae inoculated into footpads of nude mice.

The antileprosy activity of a new quinolone, sparfloxacin, was examined in the nude mouse footpad model. By serial dosing (once a day, 5 or 6 times per week, during the 3rd-5th months postinoculation), 10 mg/kg of sparfloxacin displayed bactericidal-type activity and bacteriostatic activity was present at daily doses of 5 and 2 mg/kg. By intermittent dosing (once a day, twice weekly at daily doses of 10 and 20 mg/kg or once weekly at a daily dose of 30 mg/kg, during the 3rd-5th months postinoculation), sparfloxacin markedly inhibited the growth of leprosy bacilli with slight remultiplication at later stages. Sparfloxacin seems to be worth studying clinically as a novel antileprosy drug.

Animals↗
PubMed1992

Bactericidal action at low doses of a new rifamycin derivative, 3'-hydroxy-5'-(4-isobutyl-1-piperazinyl) benzoxazinorifamycin (KRM-1648) on Mycobacterium leprae inoculated into footpads of nude mice.

Among a series of newly-synthesized benzoxazinorifamycins, 2 of the 3'-hydroxy-5'-(4-alkyl-1-piperazinyl) derivatives, named KRM-1648 and KRM-2312, whose respective alkyl residues are isobutyl and isopropyl, were examined for efficacy against nude mouse-model leprosy. KRM-1648 completely inhibited the growth of leprosy bacilli inoculated into nude mouse footpads, even 6 months after the medication had been stopped, when given orally at a daily dose of 0.6 mg/kg, 5 or 6 times weekly, during 3-5 months postinoculation. In comparison, the growth inhibition by KRM-2312 was incomplete under the same conditions, though it was still stronger than that by rifampicin. Complete growth inhibition by KRM-1648 was also observed when it was given orally at a dose of 1 or 3 mg/kg twice weekly during the same period. In contrast, the growth inhibition by rifampicin was only slight at 1 mg/kg and partial at 3 mg/kg under the same condition.

Animals↗
PubMed1991

Molecular cloning of genes encoding major two subunits of a eubacterial V-type ATPase from Thermus thermophilus.

The atpAB genes which encode the alpha and beta subunits of membrane ATPase from a thermophilic eubacterium, Thermus thermophilus HB8, were cloned. The deduced amino-acid sequences of the alpha subunit (583 amino acids) and the beta subunit (478 amino acids) are only moderately similar to the alpha beta subunits of the F0F1-ATPases, while they are highly similar to the major two subunits of the V-type ATPases, a family of ATPases which have been so far found in eukaryotic endomembrane vacuolar vesicles and archaebacterial plasma membranes. Thus, T. thermophilus ATPase belongs to the V-type ATPase family, even though this bacterium is a eubacterium. The hypothesis that the differentiation of an ancestral ATPase into V-type and F0F1-ATPase occurred after the evolution of a primordial cell into archaebacteria and eubacteria should be modified accordingly.

Adenosine Triphosphatases↗
PubMed1991

[Self-expandable metallic stent for use in arterial occlusive lesions].

Gianturco expandable metallic stents were successfully placed in 4 patients with arterial occlusive disease: aortic obstruction or stenosis due to aortitis (n = 2), dissecting aneurysm (n = 1) and arteriosclerotic obstruction of the iliac artery (n = 1). The length of lesion was from 2 to 15 cm. In one case of aortitis (case 1), eleven stents (5 and 6 stents in tandem connected by wire struts) were inserted through a 12 F Teflon sheath. In another aortitis case (case 2) 4 stents in tandem were inserted through a 10 F sheath. In the two cases the sheaths were introduced by femoral arteriotomy. In case 3 and 4 two or four stents in tandem were placed through a 8 F long sheath which was introduced via the femoral artery by Seldinger method. Symptoms disappeared after placement of stents in all four cases. Our results showed the usefulness of expandable metallic stents in the treatment of arterial occlusive diseases.

Adult↗
PubMed1991

Analysis and prevention of spinal column deformity following cervical laminectomy. I. Pathogenetic analysis of postlaminectomy deformities.

Postlaminectomy deformities were simulated in the cervical or cervicothoracic spine by the use of a displacement incremental method based on finite-element analysis combined with composite material and spanning element theory. The simulation analyses revealed that the primary cause of postlaminectomy deformity was the resection of one or more spinous processes and/or posterior ligaments (ie, ligamenta flava, supraspinous, and interspinous ligaments). After their removal, the tensile stresses that were preoperatively distributed through the posterior ligaments were transferred to the facets. This led to an imbalance of the stresses on the spinal bodies, causing deformity. The gravitational center of the head determined whether the deformity would develop as a kyphosis or increasing lordosis. As the elastic modulus of the soft tissue composites (eg, end plates, ligaments, and facets) increased, a kyphotic deformity changed gradually from swan-neck deformity, to extreme kyphotic deformity with a large curvature, and finally to a straightening deformity. Progressive kyphotic deformity is found only in children.

Adult↗
PubMed1991

The developmental mode of adolescent psychopathology: from the pathogenic viewpoint of the eating disorder.

The developmental mode of eating disorder was studied by investigating 48 cases in detail. After various factors were examined, it appeared certain that the intensification of adolescent turmoil as well as the neurotic level of determinants can become the strong driving force and the cause of eating disorder. Among most cases, the less sprightly life is dominant around preadolescence, which affects the orientation of psychopathology in adolescence. Under the influence of the developmental mode in preadolescence, every case determines how to utilize adolescent mentality (asceticism and indulgence colored by masochism and defiance vs. obedience). With this standpoint, the author illustrates how there may occur branching out of the subtype of eating disorder.

Adaptation, Psychological↗
PubMed1991

Follow-up study of camp marathon group psychotherapy for adolescents with emotional disturbances.

Every summer since 1972, the Department of Psychiatry at Fukuoka University has been holding the Camp Marathon Group Psychotherapy (MGP) for adolescents with emotional disturbances. This time we conducted a follow-up survey on 114 camp attendees from 1978 to 1985. Questionnaires were mailed out and we received 56 replies, that is a response rate of 49.1%. The average observation period of the follow-up was 4 years. The results were as follows: Thirty-six cases or 64.3% were making satisfactory progress at the time of the survey. Eight or 14.3% showed no change or showed worsening conditions. Seven or 12.5% cases developed into schizophrenia. Based on these results, we studied roughly what role MGP plays in the therapy of adolescents with emotional disturbances.

Adolescent↗
PubMed1990

[In vitro study of radiofrequency thermal angioplasty].

We performed some in vitro experiments using a radiofrequency thermal angioplasty instrument. The distribution of heat emitted from the hot tip of the device was evaluated in an agar phantom by thermography and it produced a concentric circular pattern. The temperature of the hot tip was about 290 degrees C when measured by thermocouples in the air. When the RF probe approached perpendicularly to the cadaver arterial wall, a crater with charring and coagulating necrosis was formed. However, when the RF probe traveled parallel to the arterial wall, as in normal practice, it did not seem to perforate the artery. The device could ablate non-calcified atheromatous plaque.

Angioplasty, Balloon↗
PubMed1990

[Self-expandable metallic stent for use in venous occlusions].

Expandable metallic stent was successfully introduced to 5 patients including idiopathic obstruction of the hepatic portion of the inferior vena cava (1 case), superior vena cava obstruction from metastatic lymphnodes swelling (2 cases) and IVC obstructions from liver metastases or lymphnodes metastases (2 cases). The obstructions were 4-14 cm long in the case of venous obstructions due to lymphnodes metastases and 2 cm long in the case of idiopathic hepatic IVC obstruction. In all cases, the stents were introduced by using 12-16 Fr catheter percutaneously without any complications. The stent used was connected up to 7 pieces by using wire struts depending length of the obstructions. However the stents connected more than 5 pieces were difficult to advance through the catheter. The patients who had been treated with stents had been free from hazardous complications such as lower extremity swelling, and pain.

Adult↗
PubMed1990

[Teeth arrangement of anterior artificial teeth. 1. Age and teeth exposure].

In selecting and arranging anterior artificial teeth for edentulous patients, it is necessary to consider their sex, personality, age and other factors. The relation of upper and lower lip lines to incisal edge has been one of the standards for the selection and the arrangement of anterior artificial teeth. The purpose of this report was to establish and to evaluate decision bases for the selection and arrangement. We recorded and measured the exposure rate of anterior natural teeth (48 men, 46 women) during function, such as smile, pronunciation, by means of the image analysis. Following results were obtained. 1. As the age of patients increased, upper anterior teeth appeared less than lower's. 2. Differences in exposure ratio between upper and lower teeth were found more remarkable in smiling rather than in pronunciation.

Adult↗
PubMed1990

Mouth guard and occlusal force distribution.

Mouth guards are effective to prevent traumatic injury in maxillofacial region during sports activities. This study was designed to find out the influence of wearing mouth guards on occlusal force distribution using an occlusal force transducer system (T-Scan system). Occlusal forces were more evenly distributed when mouth guards were in place comparing with natural dentition and with wearing conventional full arch bite planes.

Adult↗
PubMed1990

The influence of materials difference on stress distribution and bone remodeling around alumina and titanium dental implants.

The long-term complications of dental implants are associated with loosening of the implant-bone interface, due to bone resorption and subsequent connective tissue interposing at the implant-bone interface. Mechanical stresses, which are induced in the surrounding bone, play a key role in the interface bone remodeling. In the present study, it is investigated how local stress patterns are associated with local bone structure. For identical geometry alumina, and titanium implants, the stress patterns, determined in the finite element models with boundary conditions, are compared with the local bone structure found in animal experiments. The results indicate that there appears to be relationship between the stress patterns and the bone remodeling at the implant-bone interface independently on the materials properties in alumina and titanium.

Aluminum Oxide↗
PubMed1990

[Clinical application of T-Scan System. 2. Evaluation of soft mouth guards].

Soft mouth guards are effective to prevent traumatic injury in the maxillofacial region. In this study, we tried to find out the effect of soft mouth guards on the distribution and the magnitude of occlusal force using the T-Scan system. Ten adult subjects volunteered to exert maximum biting force wearing three different types of soft mouth guards. With the limitation of the T-scan system reported in our previous article, following results were obtained. 1) Occlusal forces were more evenly distributed with soft mouth guards than without them. 2) Softer mouth guards were more effective for occlusal force distribution. 3) Since occlusal relationship between mouth guards and mandibular arch could alter the distribution pattern a great deal, occlusion of mouth guards should be examined more carefully.

Adult↗
PubMed1990

[Mouth guard and occlusal force distribution].

Mouth guards are effective to prevent traumatic injury in maxillofacial region during sports activities. This study was conducted to investigate the influence of wearing mouth guards on occlusal force distribution with the T-scan system. With comparison to the value of average occlusal force level per occlusal point (OFL) on natural dentition and wearing conventional full arch bite plane, following results were obtained. 1) Difference of OFL within the same dental arch became smaller when mouth guards were on. 2) Statistically significant difference in OFL was not found between two mouth guards with different hardness. 3) During three seconds clenching, OFL in posterior region changed great deal at the initiation but stayed at about the same level after that.

Bite Force↗
PubMed1989

[Simulation of bone resorption in denture patients using finite element analysis. 1. Application of optimization method].

The purpose of this study was to simulate the process of bone resorption under removable denture bases. Two dimensional finite element models were prepared for the frontal section of a maxillary complete denture with its supporting mucosa and bone in the first molar region. Simulations were performed with the optimization program which could proportionally move the nodal points according to the stress level difference between the actual and the reference stress level. By exerting loads on occlusal table of the model, the bone resorption progressed in the similar manner to reported clinical observations. The location and magnitude of the resorption were highly related to the location and direction of the loads.

Alveolar Bone Loss↗
PubMed1989

[Inference engines of expert systems for designing removable partial dentures].

The expert system for designing removable partial dentures has a great potentiality for clinical and educational use. The system sorts out several solutions for clinical problems with the aid of logic and data bases stored in the memory bank. The most important part of this system is the inference engine. Production system and frame system are often used as the inference engine. The purpose of this report was to compare different types of inference engine in practical situations. Following conclusion were obtained. 1) Since each type of inference engine has its own advantages and disadvantages, one has to select most suitable one for the purpose of the system. 2) One must select the inference engine type which will help potential user's understanding.

Denture Design↗
PubMed1988

Three-dimensional model of the human craniofacial skeleton: method and preliminary results using finite element analysis.

The purpose of this study was to develop a three-dimensional finite element model of the craniofacial skeleton using a dry human skull. The model consisted of 2918 nodes and 1776 solid elements, and was used to investigate the biomechanical effect of a distally directed orthopaedic force on the craniofacial complex. The force was applied at the level of the maxillary first molar. The results indicated that in response to the force system applied: the nasomaxillary complex displaces in a backward and downward direction and rotates in clockwise sense; the nasomaxillary complex, including the zygomatic bone, experiences high stress levels in comparison with those at the remaining bones; the stress distribution in the maxillary basal bone area is relatively uniform; and the stress distribution across the opposing surface of the bony margins of the sutures is non-uniform.

Biomechanical Phenomena↗