PubMed Health⌕ Search

Biomedical subjects

K Furusawa

Publications and source records attributed to K Furusawa.

At least 19 recordsLinked to original sources
PubMed2006

Tissue reaction to poly (lactic-co-glycolic acid) copolymer membrane in rhBMP used rabbit experimental mandibular reconstruction.

A rabbit experimental mandibular defect was reconstructed with 1% atelocollagen gel including rhBMP-2 10microg and a covering a poly (lactic-co-glycolic acid) copolymer (PLGA) membrane. For this experiment, eight male rabbits were used and a histological study was conducted. Our study purpose was to examine the effects and fate of PLGA membrane during bone reconstruction. PLGA membrane was phagocytized by foreign body giant cells and macrophages in the healing course of reconstruction osteogenesis. These histological data suggest that the PLGA membrane was gradually absorbed and replaced by fibrous connective tissue or bone tissue. In the osteogenesis course, the outer periphery of the new bone was maintained by PLGA membrane without expansion.

Animals↗
PubMed2006

Brillouin characterization of holey optical fibers.

We report the results of detailed measurements on the Brillouin frequency shift (BFS), gain bandwidth, and gain coefficients of several small-core holey optical fibers (HFs) of both uniform and axially varying structural characteristics and compare these with measurements on more conventional fibers. Our measurements show that the BFS of HFs is first-order proportional to the modal index for light propagating along the fiber and is thus extremely sensitive to its precise structural parameters. Our results highlight the possibility of using distributed Brillouin scattering measurements to perform nondestructive structural characterization of HFs, and the possibility of producing Brillouin-suppressed HFs using controlled structural variation along the fiber length.

Journal Article↗
PubMed2006

Three-dimensional observation of reconstruction course of rabbit experimental mandibular defect with rhBMP-2 and atelocollagen gel.

For the experimental animals, eight rabbits were chosen. A bone defect was made and was filled with 1% atelocollagen gel including rhBMP-2 10 microg. The reconstruction course was observed using micro-computed tomography (muCT) in vivo. In muCT observation, the density was slightly elevated at the bone marrow side at day 7, and the phenomenon gradually expanded during the course of this experiment which lasted for 28 days. By utilized muCT, we could construct 3D images, and that process enabled us to visualize bone formation more closely. These data suggest that the experimental animal model muCT and 3D image are extremely useful for follow-up of reconstruction of animal bone defects and that the atelocollagen gel is effective as a carrier of rhBMP-2.

Animals↗
PubMed2006

Bone repair of rabbit mandibular transsection using rhBMP-2 and atelocollagen gel.

This experimental was carried out using 12 rabbits. A rabbit experimental mandibular transsection was reconstructed with 10mug of rhBMP-2 and 1% atelocollagen gel. The transsection gap was fixed with a titanium plate and screws, and covered with poly (lactic-co-glycolic acid) co-polymer (PLGA) membrane. Histopathological examination of 1-week specimens revealed that many spindle cells had proliferated and invaded blood clots, and a small amount of immature trabecular bone was formed in the transsection gap. In 2 and 3-week specimens, bone formation was gradually increased in the fibro-vascular tissues of the site. These histological findings were also observed in the control group specimens, but the bone formation was slightly less than in the experimental group. The results suggest the effectiveness of atelocollagen gel as a carrier of rhBMP-2 and PLGA as a covering membrane in this rabbit mandibular transsection reconstruction model.

Animals↗
PubMed2005

Overeruption without root exposure of third molars and periodontal health in the mandible.

Bone formation is seen around the third molar even when the tooth is exposed to the oral environment due to overeruption. To determine if overeruption of the third molar with or without root exposure is related to the status of the exposure of other teeth in the mandible, using orthopantomographs, 424 third molars were studied in 371 patients who were over 41 years of age. The rate of overeruption and root exposure in third molars was measured, and its relationship to the number of teeth lost and the rate of root exposure in other teeth in the mandible was analyzed. Tooth loss in the group of third molars with overeruption without root exposure was greater than in that without overeruption or root exposure in men, whereas the relationship was not seen in women. We found that root exposures of other teeth in the group of third molars with overeruption without root exposure were significantly smaller than in those with root exposure in both genders. Third molars with overeruption without root exposure, in which bone formation was easy to observe for radiographic diagnosis, were correlated with periodontal health in the mandible, suggesting a component of precision determination for predicting resistance to periodontitis.

Adult↗
PubMed2003

Nonlinear femtosecond pulse compression at high average power levels by use of a large-mode-area holey fiber.

We demonstrate that nonlinear fiber compression is possible at unprecedented average power levels by use of a large-mode-area holey (microstructured) fiber and a passively mode-locked thin disk Yb:YAG laser operating at 1030 nm. We broaden the optical spectrum of the 810-fs pump pulses by nonlinear propagation in the fiber and remove the resultant chirp with a dispersive prism pair to achieve 18 W of average power in 33-fs pulses with a peak power of 12 MW and a repetition rate of 34 MHz. The output beam is nearly diffraction limited and is linearly polarized.

Journal Article↗
PubMed2003

Relationship of the hyoid bone and posterior surface of the tongue in prognathism and micrognathia.

In order to study relationship of the hyoid bone and posterior surface of the tongue in prognathism and micrognathia, we focused on the effect of the tongue on the upper airway lumen in 16 patients with Angle's Class II and 51 patients with Angle's Class III, and assessed the position of the hyoid, the depth from the posterior surface of the tongue, from the bottom of the vallecula and from hyoid bone to the posterior pharyngeal wall using lateral cephalograms. We were able to assess significant correlations between the posterior surface of the tongue and hyoid position in Angle's Class III. However, we found no association between them in Angle's Class II. This could be an adaptive feature of the genioglossus in response to hyoid localization to serve a compensatory role to prevent respiratory impairment in micrognathia at risk of apnoea.

Adolescent↗
PubMed2001

Expression of metabotropic glutamate receptor mRNAs in the human spinal cord: implications for selective vulnerability of spinal motor neurons in amyotrophic lateral sclerosis.

To elucidate the relevance of metabotropic glutamate receptors (mGluRs) to the selective vulnerability of motor neurons in the spinal cord in patients with amyotrophic lateral sclerosis (ALS), we investigated the distribution of mRNAs coding mGluR1-5 in the normal human spinal cord. The mRNAs for mGluR1, 4 and 5 were observed in the spinal gray matter, whereas mGluR2 mRNA was absent in the spinal cord and mGluR3 mRNA was displayed only on glial cells in the white matter. Signals for mGluR1 and mGluR5 were enriched in the dorsal horn, while mGluR4 mRNA was abundant in the ventral horn. Since agonists to group I mGluRs (mGluR 1 and 5) have been demonstrated to have neuroprotective effects on spinal motor neurons, less expression of mRNAs coding mGluR1 and mGluR5 in the ventral horn than in the dorsal horn may be implicated in the selective susceptibility of spinal motor neurons in ALS.

Aged↗
PubMed2001

Relationship of third molar development and root angulation.

Angled roots are seen in mandibular third molars, which have a high frequency of incomplete impaction. We examined the relationship between incomplete impaction and angled roots. We enrolled orthopantomographs to determine the prevalence of angled roots in 239 men and 222 women aged 21--35 years with bilateral mandibular third molars. Angled roots were more frequent in subjects in whom the third molars had a different status on each side than in those with the same status on both sides (men: P<0.05; women: P<0.01). The incidence of women with angled roots in those with bilateral incomplete impactions was higher than that in those with bilateral eruption (P<0.01). Angled roots among mandibular third molars are related to environmental factors. Angled roots occur more frequently in women with incomplete impaction than in those with full eruption.

Adult↗
PubMed2001

Alteration of the angle of the coronoid process in prognathism.

Muscles and bones may dynamically affect the functions of each other, resulting in changes in the activity of the muscle and/or morphological change in the bones. However, alterations of the morphology of the coronoid process have not been documented in relation to the temporal muscle between the mandible and the cranium. Angles of the coronoid process to the line through the right and the left frontotemporale were measured on posteroanterior (PA) cephalograms in patients with normal occlusions and Class II, division 1 malocclusions, and those with true skeletal Class III malocclusions. Standard deviation of the angle of the coronoid process in patients with Class III malocclusions was greater than those subjects with normal occlusion or Class II, division 1 malocclusions. Differences of angles between the right and the left coronoid process in each patient of either sex were significantly large in true skeletal Class III malocclusions (both P < 0.001). Large variation of angle of the coronoid process was related to prognathism, and this effect may represent adaptation of temporal muscle function to a variety of alterations in mandibular morphology.

Adaptation, Physiological↗
PubMed2000

Synthesis and Physical Properties of Sterically Congested Cycloalkenes, 1,2-Di-tert-butyl-3,3,5,5-tetramethylcyclopentene and 1,2-Di-tert-butyl-3,3,6,6-tetramethylcyclohexene.

Two sterically congested cycloalkenes (9 and 10), congeners of tetra-tert-butylethylene, were synthesized and characterized. Oxidation of the bicyclic 1,3-dithietane 8 with dimethyldioxirane (DMD) gave the endo,endo-disulfoxide 13, thermal isomerization of which to the endo,exo-disulfoxide 15 followed by oxidation with DMD gave the trioxide 18. Heating 18 in refluxing 1,3-dimethyl-2-imidazolidinone furnished 1,2-di-tert-butyl-3,3,5,5-tetramethylcyclopentene (9) in 69% yield by a 2-fold extrusion process. The reaction of the 1,6-diketone dihydrazone 23 with Se(2)Cl(2) gave the selenadiazoline 34 and the 1,3-diselenetane 35. Heating 34 at 115-130 degrees C gave 1,2-di-tert-butyl-3,3,6,6-tetramethylcyclohexene (10), a "didehydro" derivative of tetra-tert-butylethylene, in 43% yield. The C=C bond in 10 is strained in degree comparable to those of most strained alkenes reported so far.

Journal Article↗
PubMed1999

Wheelchair marathon racing causes striated muscle distress in individuals with spinal cord injury.

OBJECTIVE: To assess the effects of wheelchair marathon racing in individuals with spinal cord injury (SCI) on circulating muscle enzymes and myoglobin. SUBJECTS: Thirty-one men with SCI, including 25 wheelchair marathon athletes and 6 sedentary men. DESIGN: Serum myoglobin (Mb), creatine kinase (CK) activity, and lactate dehydrogenase (LDH) were measured in participants of the 1995 Oita International Wheelchair Marathon Race (42.195 km). Blood samples were obtained 24 hours before, immediately after, 24 hours after, and 7 days after the race. RESULTS: Marathon racing resulted in significant increases in serum Mb, total CK activity, and LDH (p<.01) after the race. The peak Mb and LDH levels occurred immediately after the race; total CK activity peaked 24 hours after the race. Evaluation of cardiac muscle enzymes showed no significant changes in two CK isoenzymes (CK-MM and CK-MB). CONCLUSIONS: Propulsion of the wheelchair in a marathon race induced muscle stress in athletes with SCI. Completion of the marathon race did not cause cardiac muscle damage, however. Elevated muscle enzyme levels likely resulted from muscle distress rather than from dehydration.

Adult↗
PubMed1999

Root resorption of mandibular second molar teeth associated with the presence of the third molars.

Although pressure resorption of second molars is associated with impacted and/or erupting third molars, the relationship between pressure resorption and age is unclear. In order to investigate this relationship, 3883 dental radiographs were studied in 3174 individuals of various ages. The incidence of superimposition of the second molar on the third molar was not elevated in any subgroup except that of women of 16-40 years of age. There were no age or sex differences for the incidence of second molar root resorption. In older individuals, root resorption associated with a completely impacted third molar was more frequent than with a partially impacted third molar, and root resorption at the apex was mainly seen in individuals over 50 years of age. There was a higher incidence of superimposition and root resorption in men than women. Apical root resorption may be seen long after the formation of completely impacted third molars in both genders.

Adolescent↗
PubMed1999

Synthesis and muscarinic activity of novel aniline derivatives with a 1-azabicyclo[3.3.0]octane moiety.

In order to develop drugs effective against Alzheimer's disease, we synthesized a series of aniline derivatives having a characteristic cyclic amine, 1-azabicyclo[3.3.0]octane ring, and evaluated their binding affinity for the central muscarinic cholinergic receptor. Among these compounds which showed high affinity to the M1 receptor, N-[2-(1-Azabicyclo[3.3.0]octan-5-yl)ethyl]-2-nitroaniline (9f fumarate, SK-946) showed the highest affinity. The ability of this compound to improve cognitive function was assessed using the passive avoidance test in scopolamine-induced dementia mice. Some anilines with a 1-azabicyclo[3.3.1]nonane ring were also synthesized by the ring expansion of the 1-azabicyclo[3.3.0]octane ring, and showed a high affinity for the central muscarinic cholinergic receptor.

Aniline Compounds↗
PubMed1998

Differences in Thinning Processes of Some Vesicular Foam Films with Different Compositions.

Thinning processes of foam films are observed for various phospholipid vesicle suspensions by the horizontal suspending method using an interferometric microscopy system. It is found that the phospholipid components that construct the bilayer of unilamellar vesicles or micelles affect the thinning process behavior of the plane-parallel liquid film. In the case of vesicle from egg phosphatidylcholine (PC), the plane-parallel foam film made of its suspension shows a gradual but inhomogeneous slow thinning process, which differs from the stepwise thinning process of thin liquid films with silica or micelle suspensions reported in previous investigations. However, when lysophosphatidylcholine was mixed with egg PC, channel formation and coexistence of black thin films and thicker regions were observed. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Gender differences in disability and lifestyle among community-dwelling elderly stroke patients in Kitakyushu, Japan.

OBJECTIVE: To examine whether there were differences in lifestyle and performance of activities of daily living (ADL) between men and women in a population of elderly stroke patients. DESIGN: Case-comparison study. MATERIAL AND METHODS: Sixty-eight men and 34 women who were elderly stroke patients living in the community with a spouse or family members were evaluated with the self-rating Barthel Index (SRBI), Frenchay Activities Index (FAI), Stroke Impairment Assessment Set (SIAS), Functional Independence Measure (FIM), and a pedometer for physical activity. Control subjects, 30 men and 30 women, were assessed with the FAI. RESULTS: Among the stroke subjects, there were no significant differences in age, SRBI, motor score of the SIAS, or physical activity between men and women; however, men had significantly lower values than did women for three FIM items and the total FIM score and for 6 FAI items and the total FAI score. Among control subjects, men had significantly lower values than did women for 7 FAI items and the total FAI score (Tukey's test, p < .05). CONCLUSION: Among elderly stroke patients, men received more support from family members in ADL performance and had less active lifestyles than did women, possibly because of cultural gender roles.

Activities of Daily Living↗
PubMed1998

Short-term attenuation of natural killer cell cytotoxic activity in wheelchair marathoners with paraplegia.

OBJECTIVE: To investigate homeostasis of the immune system in athletes with spinal cord injuries during and after racing a wheelchair marathon. DESIGN: The study examined changes in the number and function of natural killer (NK) cells in nine male wheelchair marathon athletes (spinal cord injuries between T5 and T12) who completed the 15th Oita International Wheelchair Marathon Race. Blood samples were obtained the day before, immediately after, and 1 day after the race. Blood samples were also obtained from seven age-matched control subjects with spinal cord injuries but who did not exercise regularly. RESULTS: The number of peripheral leukocytes increased (p < .01) immediately after the race. In contrast, the number of peripheral NK cells and NK cell cytotoxic activity significantly decreased from 310+/-130/microL to 133 +/-61/microL and from 42.6%+/-3.0% to 38.2%+/-3.2%, respectively (mean+/-SD), immediately after the race. Plasma cortisol levels were increased after the race. However, all parameters returned to control levels within 24 hours. Measurements in control subjects did not change throughout the experiment. CONCLUSION: These findings suggest that racing a marathon suppressed peripheral NK cell number as well as NK cell cytotoxic activity in wheelchair athletes and that this was probably mediated by increased postrace cortisol levels. Wheelchair marathon athletes are advised to take extra precaution to avoid infection within 24 hours after racing because of the transient suppression of NK cell cytotoxic activity during this period.

Adult↗