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Biomedical subjects

A Shiba

Publications and source records attributed to A Shiba.

At least 19 recordsLinked to original sources
PubMed2000

Endosseous titanium implants as anchors for mesiodistal tooth movement in the beagle dog.

The purpose of this study was to determine the anchorage potential of titanium implants (Branemark; 3.75 x 7 mm) with the use of a sectional arch wire technique for orthodontic mesiodistal tooth movement, as assessed by the osseointegration of implants and tooth movement. Two implants were surgically placed in healed mandibular extraction sites of the second and third premolars on each side in 4 adult male beagle dogs. The implants were surgically uncovered 18 weeks later, and second-stage abutments with soldered edgewise tubes were attached. Segmented edgewise rectangular archwires (0.017 x 0. 025 inch) with a T-loop or an L-loop were placed between the implants and the fourth premolars on both sides as the anchorage unit. One segment in each dog served as a loaded side, and the archwire was calibrated to produce 200 g of lateral force on the fourth premolar. The contralateral segment served as an unloaded side and was not subjected to orthodontic force. Sectional wires were activated biweekly 24, 28, 28, and 32 weeks, respectively, depending on the magnitude and the appearance of mesial tipping movement of the fourth premolar. After mandibular impressions were taken to measure the distance between the first molar and the fourth premolar, the animals were euthanized and dissected mandibles were prepared. The specimens were then embedded in polyester resin and cut to take backscattered electron images. On the basis of these images, the percentage of peri-implant bone volume was calculated and defined as an index of osseointegration. The differences between the initial and final fourth premolar to first molar distances varied (7.40, 8.85, 10.50, and 3.30 mm) on the loaded side, whereas the unloaded side showed no movement. Not only was there no statistical difference in the percent of peri-implant bone volume between the loaded and unloaded sides, but there was also no statistical difference between the compression and tension sides in both loaded and unloaded implants, which suggests that the implants maintained rigid osseointegration. In conclusion, the present study demonstrated that endosseous titanium implants can function as anchors for long-term orthodontic mesiodistal movement.

Alveolar Process↗
PubMed2000

Brief communication: heat-induced accumulation of p53 and hsp72 is suppressed in lung fibroblasts from the SCID mouse.

PURPOSE: To investigate how DNA-dependent protein kinase (DNA-PK) contributes to p53-dependent signal transduction after heat shock, thermosensitivity and accumulation of p53 and hsp72 after heat shock in lung fibroblasts derived from the SCID mouse were analysed. MATERIALS AND METHODS: Thermosensitivity at 44 degrees C in colony-forming units and Western blot analysis of p53 and hsp72 were analysed. RESULTS: The results indicated that (1) the thermosensitivity at 44 degrees C of SCID cells was higher than that of parental cells and (2) heat-induced accumulation of p53 and hsp72 was abolished and suppressed in SCID cells as compared with that in parental cells respectively. CONCLUSIONS: The findings suggest that the catalytic subunit of DNA-PK may play an important role upstream of p53 and hsp72, which are possible determinants of cellular thermosensitivity.

Animals↗
PubMed1999

Reconstruction of full-thickness lower eyelid defects using a blepharoplasty technique with a hard palate mucosal graft.

The authors report a method of reconstruction of a full-thickness lower eyelid defect using a blepharoplasty technique utilizing excess skin of the lower eyelid with a hard palate mucosal graft. In all patients the hard palate mucosa took well, and good functional and aesthetic results were obtained. The most suitable indication of this technique might be for the defect occurring horizontally (for which direct closure is difficult to apply) and located in the lateral side of the lower eyelid (when a large amount of excess skin can be utilized). The authors conclude that although the shape and size of the defect to which this method can be applied is restricted, this is a useful option in the reconstructive methods of a full-thickness lower eyelid defect.

Aged↗
PubMed1999

An experience of pubic hair reconstruction using free temporoparietal fasciocutaneous flap with needle epilation.

Lack of pubic hair may cause suffering for pubescent and adult patients; thus, rapid and precise reconstruction is required for their mental health. We reported pubic hair reconstruction for burn alopecia using a free temporoparietal fasciocutaneous flap transfer with needle epilation. Fourteen months after the reconstruction, an acceptable aesthetic result was obtained, and our patient is satisfied with her reconstructed pubic hair. We conclude that reconstruction using a free temporoparietal fasciocutaneous flap with needle epilation is a useful method for selected patients.

Adult↗
PubMed1998

Earlobe reconstruction using a subcutaneous island pedicle flap after resection of "earlobe keloid".

BACKGROUND: A large keloid of the earlobe is a difficult case in which to obtain a satisfying result by nonsurgical therapies. In this case, surgical resection of keloids should be considered as a first step in therapy. However, it is difficult to reconstruct the earlobe cosmetically after resection of the lesion. OBJECTIVE: To discuss the usefulness of the subcutaneous island pedicle flap in earlobe keloid surgery. METHODS: Five earlobe keloids in five patients (four females and one male) were resected and reconstructed by subcutaneous island pedicle flap. RESULTS: In all patients, there were no keloid recurrences and no adjuvant therapies used during the follow-up periods, which ranged from 10 to 26 months. The reconstructed earlobes were almost symmetrical. CONCLUSION: In the selected cases, use of the subcutaneous island pedicle flap is a viable method to be considered for reconstruction after resection of earlobe keloids.

Adult↗
PubMed1998

Three cases of primary pulmonary amyloidosis.

In three cases of primary pulmonary amyloidosis the chief complaint was hemosputum. The diagnosis of amyloidosis was made using histochemical analysis of bronchial wall biopsy in all cases; multiple nodular lesions were observed in trachea and bronchi on flexible fiberoptic bronchoscopy. The surface of the tracheobronchial mucosa was smooth but bled easily. In one patient, chest X-ray film showed a solitary nodular shadow in the left lower lung field. These three cases were tracheobronchial amyloidosis, and one case was combined with nodular parenchymal type amyloidosis.

Aged↗
PubMed1997

Vulval reconstruction using rectus abdominis musculocutaneous flap transfer with secondary liposuction in extramammary Paget's disease.

Two female patients with vulval skin defects after extramammary Paget's disease were reconstructed using a pedicled, distally based rectus abdominis musculocutaneous flap. After the operation, the bulkiness of the flap, which might be a major problem in the application for a vulval skin defect, was improved successfully by flap volume reduction with secondary liposuction. We conclude that rectus abdominis musculocutaneous flap transfer with secondary liposuction is one of the acceptable methods for reconstructing vulval skin defects.

Biopsy↗
PubMed1996

Performance evaluation of the FACSCount System: a dedicated system for clinical cellular analysis.

Flow cytometers are instruments that can determine multiparameter data simultaneously and have a great potential in providing unique information about cells. The FACSCount System is designed as the first dedicated flow cytometer for the clinical laboratory. Its current configuration provides CD4, CD8, and CD3 absolute counts from 100 microliters of whole blood. Adapting the FACSCount System to the clinical setting are minimal sample handling, lysis free cell preparation, automated fluorescence gating, built-in calibrated reference beads, and appropriate error code reporting. Quality control checks ensure that reported CD4 counts, important for clinical follow-up and patient management, are accurate, precise, and reproducible across instruments over time.

Adolescent↗
PubMed1995

Validation of transthoracic myocardial ultrasonic tissue characterization: comparison of transthoracic and open-chest measurements of integrated backscatter.

To investigate whether myocardial integrated backscatter (IB) can be measured through the chest wall, myocardial IB parameters were measured in five adult mongrel dogs with a newly developed IB imaging system capable of measurements of myocardial IB relative to backscatter from the blood. There was no significant difference in the calibrated myocardial IB between the closed chest and the open chest conditions either in the septum or in the posterior wall if a 2.5- or 3.5-MHz frequency transducer was used. There was no significant difference in the magnitude of cyclic variation in IB between the closed chest and the open chest conditions independent of the frequency of the transducer used. These data suggest that we can accurately measure not only the magnitude of cyclic variation in IB but also the calibrated myocardial IB through the chest wall with a 2.5- or 3.5-MHz frequency transducer. Such data may validate measurements of myocardial IB parameters through the chest wall even in humans.

Algorithms↗
PubMed1991

Identity of hemolysins produced by Bacillus thuringiensis and Bacillus cereus.

A hemolysin (Bt-hemolysin) produced by Bacillus thuringiensis var. kurstaki HD-1 producing crystalline toxin(s) was purified by successive treatments of ammonium sulfate (45-65%) and column chromatography using DEAE-cellulose, Sephadex G-75 and KB-002 (a hydroxyapatite column for fast protein liquid chromatography). A hemolysin (Bc-hemolysin) produced by B. cereus HG-6A was also purified by the same procedure. The purified Bt-hemolysin and Bc-hemolysin, both of which are thiol-activated hemolysins, were biologically, physicochemically and immunologically identical. These findings provide further evidence of the similarity of B. thuringiensis, which is being used as a biological insecticide, to B. cereus, a toxigenic organism of food poisoning.

Bacillus cereus↗
PubMed1990

Adhesive bonding of denture base resins to plastic denture teeth.

The adhesive bonding of denture teeth to denture base resins in dentures with conventional acrylic teeth and crosslinked plastic teeth was investigated. The dentures with highly crosslinked plastic teeth such as SR-Orthosit, Crystal ND, and Mitel-OM showed poor bonding at the tooth/base resin interface using the conventional bonding method. Elimination of the alginate mold lining material in the conventional bonding method effectively improved bonding at the tooth/base resin interface. The application of 4-META adhesive bonding agents to the denture teeth improved the interface bonding of highly crosslinked plastic teeth and the denture base. Dentures with Orthosit and Mitel showed differences in bonding ability when two different adhesives were used.

Acrylic Resins↗
PubMed1990

Impact resistance of highly crosslinked plastic denture teeth.

The impact resistance of highly cross-linked plastic denture teeth materials such as SR-Orthosit (R), Crystal-ND (R), and Mitel-OM (R) was investigated and compared to that of conventional denture teeth materials. Dentures with upper second molars were placed on a metal model. The thicknesses of the denture teeth were 1.4, 1.0, and 0.4 mm. An impact force was repeatedly applied to the central fossae of the denture teeth with an impact test machine. Impact resistance was defined as the number of impacts sustained by the tooth material prior to fracture. The results showed that the impact resistance of highly crosslinked plastic teeth decreased with decreasing thickness, but was comparable to that of conventional plastic teeth when the teeth were 1.4 mm thick and supported by denture base resin. It is hypothesized that the layer of PMMA denture base resin beneath the denture teeth functions as a shock absorber during impact.

Dentures↗
PubMed1990

[Analysis of the denture dynamics in R.P.D.'s. 2. Influence of retainers on the dynamics of free-end-saddle].

The ordinary denture movement during function is defined as the "Denture dynamics" in R.P.D.'s. by K. H. Körber (1975). The Author has already reported the evaluating method of the denture dynamics objectively by two ways: The displacement sensors of magnetoresistors detected the vertical and horizontal movements of denture saddle in free end situation. Tiny accerelometer also detected the accerelation during the movements. In this present study, the correlations among the retainers used, the extent of the denture dynamics in displacement and accerelation, the occluding force and the abutment tooth mobility induced by the denture support were correlatively evaluated in two patients with class I free end R.P.D.'s. with interchangeable retainers by above methods. All the data were collected simultaneously by the electronic measuring and recording apparatus. Following results were obtained: 1. The denture dynamics depended on the selection of retainers examined. The extent of the dynamics reduced from the denture with the wrought wire clasps, the denture with the cast clasps, then to the denture with cone crown telescopes in sequence. 2. The occluding force increased just as the changes in sequence of the denture dynamics. 3. The abutment tooth moved to the distal in each case. The highest value of the mobility was found in the denture with the cast clasps, then in the denture with the wrought wire clasps. The least value of the tooth mobility was found in the denture with the cone crown telescopes. These results will strongly support the concept of the free end saddle R.P.D.'s anchored and supported rigidly by the abutments and the residual ridges in clinics.

Dental Abutments↗
PubMed1990

[The evaluation of wear resistance of hybrid denture teeth].

Wear characteristics of hybrid denture teeth, plastic denture teeth which were partially reinforced with metal, was evaluated. The plane specimens were made up with resin and metal. Light curing veneering resin, new metacolor, heat curing veneering resin, Mitel-OM and PMMA (Poly methyl methacrylate) were used for resin parts, while gallium containing filling alloy, silver alloy, palladium alloy and titanium containing chromium cobalt alloy were used for metal parts. The specimens were abraded by the rod specimens of palladium alloy with abrasion test machine. The wear depth and width were measured at 1, 5, 10 and 20 x 10(4) times of abrasion which stroke was 10 mm each. The specimens of heat cured veneering resin reinforced with chromium cobalt alloy showed the least wear loss while the specimens of PMMA reinforced with silver alloy did the most. The difference of wear ratio between light cured and heat cured veneering resin was not statistically significant.

Dental Alloys↗