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Biomedical subjects

R Takiguchi

Publications and source records attributed to R Takiguchi.

At least 19 recordsLinked to original sources
PubMed2006

The effect of adding calcium lactate to xylitol chewing gum on remineralization of enamel lesions.

The purpose of the study was to determine whether adding calcium lactate to chewing gum containing xylitol enhances remineralization of enamel surfaces using an early caries lesion model. Enamel slabs were cut from human extracted sound teeth and artificial subsurface lesions created within each. Half the enamel slabs were used as controls and stored in a humidifier while half were mounted into oral appliances worn by 10 volunteers (22-27 years old, 2 males and 8 females) in a three-leg trial, during which they wore the appliance without chewing gum, chewed gum containing xylitol + calcium lactate or chewed gum containing only xylitol 4 times a day for 2 weeks. Calcium concentrations in the enamel surfaces of control and test slabs were measured by X-ray spectrometry and degrees of remineralization were calculated. The mean degree of remineralization was greater after chewing xylitol-Ca gum (0.46 +/- 0.10) than after no gum (0.16 +/- 0.14) or after chewing xylitol gum (0.33 +/- 0.10) (p < 0.01). In conclusion, chewing gum containing xylitol + calcium lactate could enhance remineralization of enamel surface compared to chewing gum containing only xylitol or no gum chewing.

Adult↗
PubMed2001

Three dimensional ultrastructure of transverse (Harris) lines in the long bone.

To investigate the occurrence of transverse lines in long bones of adults, we studied 27 cadavers (14 males and 13 females). After confirming the presence of a transverse line, a cross-sectional sample was examined macroscopically, and by soft X-ray and scanning electron microscopy. The following results were obtained: 1. According to roentgenograms, transverse (Harris') lines were observed in 40.7% of the distal half of the femur and in 29.6% of the proximal half of the tibia. 2. Macroscopic examination of the bone cross-sections at the level of the transverse line showed various membranous structures. 3. In scanning electron micrographs, no marked difference in structure was observed between the transverse line trabeculae and the compact bone.

Aged↗
PubMed1999

Relationship between the lingual-palatal contact duration associated with swallowing and maxillofacial morphology with the use of electropalatography.

To investigate the relationship between movement of the tongue during swallowing and malocclusion, the relationship between the lingual-palatal contact duration associated with swallowing and maxillofacial morphology was examined by electropalatography, cephalometric radiography, and dental casts. Seventy-one subjects (35 men and 36 women, 18 to 38 years of age) with normal occlusion or various types of malocclusion were used. Simple correlation analysis showed correlations between the time required for swallowing and the angles-FH-U1, L6-MP, FH-MP and Go-measured by lateral cephalometric radiography. In multiple regression analysis, five angles-FH-U1, L6-MP, FH-Occ, FH-SGna and NF-MP-measured by lateral cephalometric radiography were chosen as the independent variables, and significant regression equations and multiple correlation coefficient were obtained. It was concluded that the lingual-palatal contact duration associated with swallowing observed by electropalatography differs among persons; this is closely related to the maxillofacial morphology and significantly correlated with the measurement items representing the rotation of the lower jaw and inclination of upper incisors.

Adolescent↗
PubMed1997

Morphometric examination of the free scapular flap.

In this study we investigated the clinicoanatomic basis of the scapular flap by morphometric examinations of 42 cadavers. Our findings were as follows: With common-trunk type scapular vessels, the maximal lengths of arteries and veins that could be used for a flap pedicle were 93 and 91 mm. With direct-type scapular vessels, the maximal lengths were 95 and 71 mm. In common-trunk type vessels, the mean internal diameter 2 mm distal from the confluence of the scapular vessel was 2.8 mm for arteries and 3.3 mm for veins. In the direct-type vessels, the mean internal diameter 2 mm distal from the confluence of the circumflex scapular vessel was 1.8 mm for arteries and 3.3 mm for veins. The maximal superoinferior dimension of the scapular graft was 28 mm. The maximal lateral dimension of the scapular graft was 12 mm.

Adult↗
PubMed1996

An anatomical study on the forearm vascular system.

The purpose of the present study was to establish the clinicoanatomical basis for the radial forearm flap. We conducted a morphometric investigation on 52 Japanese cadavers, of forearm vessels, for use in free forearm flaps. The mean inner diameter of the cephalic and median cubital veins at the interepicondylar line was 1.9 +/- 1.2 mm and 1.8 +/- 1.1 mm, respectively. Mean inner diameter of the radial artery and venae comitantes 1 cm distal to the origins of the radial and ulnar arteries was 2.3 +/- 0.5 mm and 1.6 +/- 0.5 mm, respectively. The longest segment of a superficial vein was 28.7 +/- 4.6 cm, it was measured between the basilic vein 5 cm proximal to the interepicondylar line and the cephalic vein at Lister's tubercle. The length of the radial artery was 18.1 +/- 1.7 cm. There were fewer valves in the basilic vein and cephalic vein proximal to the median cubital vein and in the brachial veins than in the distal antebrachial veins. From these results some of the clinicoanatomical considerations of forearm vessels which will form the clinicoanatomical basis of the free forearm flap should be clarified.

Adult↗
PubMed1995

Backscattered electron imaging and energy-dispersive X-ray microanalysis studies of evidence for calcium salt heterogeneity in fifteen gallstones from an elderly human.

We examined 15 variably-sized gallstones, taken from an elderly male, by backscattered electron imaging and energy-dispersive X-ray microanalysis to learn the structural and distribution patterns of gallstone calcium (Ca-) salts. Of the 13 cholesterol-rich stones, nine stones had peripheral concentric layers of Ca-carbonate, whereas 2 stones had peripheral layers of Ca-phosphate. No Ca-salts were detected from 2 cholesterol-rich stones. The 2 stones containing Ca-phosphate had no Ca-salt cores, whereas the stones containing Ca-carbonate were separated into 3 different types: two stones with a Ca-carbonate core, four stones with several Ca-bilirubinate cores of glass-like structure, and 3 stones lacking Ca-salt cores. A closer view of the Ca-salt layers, which may be occasionally coexistent with Ca-bilirubinate, mainly showed either laminate deposits or numerous globules with a few laminae. Of the 2 cholesterol-poor stones, one had dispersed particles mainly of Ca-phosphate, and the other had loosely dispersed particles with small amounts of Ca-phosphate, bilirubinate, and/or palmitate. Some relationship between the size and Ca-salt species of these gallstones was suggested. Gallstones collected from the same individual showed a considerable heterogeneity of Ca-salts.

Aged↗
PubMed1995

The structural patterns and mineralization values of prismless enamel, a case of mild enamel hypoplasia.

In examining the prismless enamel (PL) distribution from the inner to surface layers of a human incisor with hypoplastic perikymatas with enamel pits, we determined the structural patterns and mineralization values by microradiographic, optical, and scanning electron microscopic observations. The PL containing abnormal prisms ranged from 20 to 250 micrometers in thickness. The alternated layers of the PL and prismatic enamel, in parallel with the Retzius lines, showed a roughly zigzag pattern based on the main orientation of enamel crystals. Such a pattern suggests an alternation of the disappearance and reappearance of Tomes' processes, which may have strong restorative and reactive capacities. In the mineralization values determined by microradiography, the PL was higher in the well-marked lines of Retzius, while the PL under the hypoplastic enamel pit and an area within the thick PL showed hypomineralization. The backscattered electron images indicated that the fine laminate striations and abnormal prismatic rows within the PL were hypomineralized, and the PL in the inner enamel showed a lower mineralization than the adjacent prismatic layer. Thus, the disappearance of Tomes' processes, which form prismless structures, may be unrelated to changing the mineral amount in amelogenesis.

Ameloblasts↗
PubMed1993

Identification of the replication region of Streptococcus thermophilus No. 29 plasmid pST1.

The replication region of the 2.77-kilobases (kb) plasmid pST1 from Streptococcus thermophilus No. 29 was identified. Deletion derivatives of pST1 were introduced into plasmid-free S. thermophilus No. 29 and examined for their ability to replicate autonomously. The nucleotide sequence had one open reading frame encoded for a 315 amino acid protein (Rep). Comparisons with proteins encoded by other Gram-positive bacterial plasmids strongly suggest that the deduced protein (RepS) encoded by pST1 has a replicative role. pST1 also contains a DNA sequence similar to the origin nick sequences of pLP1 or pLAB1000, which initiate plasmid replication at the plus origin. In a maxicell system, E. coli CSR603 carrying pSTUC4 produced a protein that was considered to correspond to the product of the RepS gene. These results strongly suggest that pST1 is replicated following a rolling-circle mechanism via single-stranded DNA intermediates.

Amino Acid Sequence↗
PubMed1992

Ultrastructural alteration of cartilaginous fibril arrangement in the rat mandibular condyle as revealed by high-resolution scanning electron microscopy.

Three-dimensional alteration of fibrillar matrix in the rat mandibular condylar cartilage was investigated with a high-resolution scanning electron microscope (SEM) and it was determined whether alterations correlate with developing occlusion and advancing age. Two important SEM techniques of DMSO freeze-cracking and treatment with trypsin and hyaluronidase were employed to remove interfibrillar proteoglycans and disclose fibril arrangement. Our SEM investigation demonstrated that collagen fibrils in the fibrous zone covering hyaline-cartilaginous area in the condyle are thicker (50 to 80 nm in diameter) than the fibrils (30 to 50 nm in diameter) that predominantly constituted an interterritorial fibrillar matrix (IFM) in the area. While the thick fibrils had a distinct striation of about 55 nm periodicity, the thin fibrils had no distinguishable striation. The thick fibrils having a periodic striation of about 60 nm was found along with the thin fibrils, also in the IFM in the aged rats and in the deep IFM, but were considerably less than the thin fibrils. The fibrils in the fibrous zone and IFM were disorderly arranged at 19-day-insemination age. In 1-week-old rats whose incisors erupted, the fibrils constituting the fibrous zone altered from disordered to ordered arrangement. The IFM in these rats took the form of a network. Incorporation of small fibrillar bundles into the fibrillar network was seen in 2-week-old rats whose upper and lower first molars erupted. In 8-week-old rats whose molars had erupted completely, the IFM completely occupied by regularly oriented fibrils appeared additionally.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Anatomical study of the valves of the superficial veins of the forearm.

The valves of the cephalic, basilic and median cubital veins were investigated in the superficial veins of the left forearm in 9 cadavers, aged 25-95. The radial forearm flaps involving these veins are of special clinicoanatomical importance. The following results were obtained: (1) Valves were most frequently evident at Site G of the cephalic vein. No valves were present in Section A-B, (2) type B valves were located at confluences, junctions and branches and were more frequent (54.7%) than Type A (45.3%) located in the straight trunks of superficial forearm veins, (3) Type 2 valves accounted for most (82.3%), and these were followed by Type 1 and Type 4b (5.9%), Type 4a (4.4%) and Type 3 (1.5%).

Adult↗
PubMed1992

Establishment of a host-vector system in Lactobacillus helveticus with beta-galactosidase activity as a selection marker.

A host-vector system was established in Lactobacillus helveticus with beta-galactosidase activity as a selection marker. Plasmid pBG10 was constructed by joining the beta-galactosidase gene from L. bulgaricus, the promoter region of the erythromycin resistance gene from pAM beta 1, the replication region of pBR329, and the replication region of the L. helveticus cryptic plasmid pLJ1. L. helveticus SBT2195 (Lac- mutant), transformed with pBG10, was selected on skim milk plates. The structural gene of alpha-amylase (1536 bp) from Bacillus licheniformis, inserted downstream of the promoter region of the erythromycin resistance gene of pBG10, was expressed in L. helveticus SBT2195. Plasmid pBG10 is a food-grade and expression vector in L. helveticus.

Base Sequence↗
PubMed1990

Transformation of Lactobacillus helveticus subsp. jugurti with plasmid pLHR by electroporation.

Lactobacillus helveticus subsp. jugurti was transformed with plasmid, pLHR (8.5 kilobases), by electroporation. The plasmid, pLHR, consists of a cryptic plasmid, pLJ1, from L. helveticus subsp. jugurti, the Escherichia coli vector pBR329, and the erythromycin resistance gene of pAM beta 1 from Enterococcus faecalis. Maximum transformation efficiency of 1.3 x 10(4) transformants per microgram of DNA was obtained by exposure to a pulse with an exponential decay waveform at 4 kV/cm with 25 microF capacitance. The presence of glycine in the growth medium was essential for transformation. Plasmid DNA isolated from transformants had not undergone detectable rearrangements or deletions. In addition, it was found that L. helveticus subsp. jugurti has a restriction and modification system.

Culture Media↗
PubMed1989

Complete nucleotide sequence and characterization of a cryptic plasmid from Lactobacillus helveticus subsp. jugurti.

A small cryptic plasmid, pLJ1, was isolated from Lactobacillus helveticus subsp. jugurti and was cloned into Escherichia coli HB101 by using pBR329 as a vector. Plasmid pLJ1 was 3,292 base pairs long and had single restriction endonuclease sites for PvuII, KpnI, AvaII, Acci, HindIII, and EcoRI. In a maxicell system, pLJ1 produced a protein of about 41 kilodaltons.

Amino Acid Sequence↗
PubMed1989

High-resolution scanning electron microscopy of formative osteoblasts, with special emphasis on intracellular membranous organelles.

Formative osteoblasts in immature bone obtained from newborn rats were examined with a high-resolution scanning electron microscope. The three dimensional ultrastructures of intracellular membranous organelles in formative osteoblasts were revealed by the maceration and extraction of cytoplasmic soluble elements with dilute osmium tetroxide after DMSO (dimethyl sulfoxide) freeze-cracking in liquid nitrogen. Typical formative osteocytes covering self-produced unmineralized matrix were plumply ovoid or ellipsoid in shape. Their cytoplasms were filled with intracellular organelles related to matrix-formation such as Golgi apparatus, mitochondria, and well-developed rough endoplasmic reticulum (RER). The Golgi apparatus of formative osteoblast was composed of the three kinds of prominent elements, which were lamellar portions stacked several cisterns with some fenestrations, abundant vesicles, and vacuoles. The Golgi cisterns frequently extended continuing in a circle. A large number of spherical protrusions indicative of arising the vesicles and elongated tubular structures were usually observed in a part of the Golgi cisterns. The tubular structures which mediated between adjoining Golgi cisterns, or between the Golgi cisterns and RER in the Golgi area, presumably play an intercommunication role in secretion products. The RER was highly oriented in almost parallel rows from both the Golgi area and nucleus to the cell margins, while small in the Golgi area. The RER had enlarged fenestrations than that of the Golgi cisterns. Minute ribosomes of about 28 nm were associated closely with the membrane surface of the RER facing the cytoplasmic matrix.

Animals↗