Biomedical subjects
Publications and source records attributed to M Nakata.
Tracheo-innominate artery fistula is one of the severest complications associated with tracheostomy. Early recognition and prompt aggressive therapy are necessary. An 18-year-old male patient who had this complication was surgically managed with success. The pathogenesis and treatment of tracheo-innominate artery fistula are discussed.
The volume of incisor dentin formation was investigated semilongitudinally using the time-marking method during the reproductive cycle of pregnancy, parturition, lactation, and post-weaning in mice, and was compared with unmated, non-pregnant control mice. DDD/Qdj mice were injected with nitrilo-tri-acetate lead acid solution subcutaneously at 4-day intervals. Serial cross sections of 100 microns thickness were prepared from the edge of the tooth to the apical portion. Each area of dentin, encircled by adjoining lines labeled with the lead that was formed at 4-day intervals, was measured by means of an image scanning system. The total amount of dentin formation per 4-day intervals was quantified as a volume in all animals. In the control animals, there was no significant difference at each period throughout the experiment. However, the volume of dentin formation increased during the reproductive cycle over that of the control. The increase in volume was significant (P < 0.0001). In addition, during pregnancy, the volume increased gradually with the greatest increase seen in the last 4 days of pregnancy, including the day of parturition, as compared with the first half-term of pregnancy (P < 0.05). The volume decreased immediately after parturition as compared with the latter half-term of pregnancy (P < 0.05). The results of the present study suggest that the volume of dentin formation is affected by the change of maternal metabolism during the reproductive cycle in mice.
Human osteocalcins having two (positions 21 and 24) or three (positions 17, 21 and 24) gamma-carboxyglutamic acids (Gla) were synthesized in solution employing both the Boc strategy and the HF procedure for the final deprotection. During synthesis, the gamma,gamma-dicarboxyl functional groups of the Gla residues were protected by the cyclohexyl group. The identity of the synthetic peptides was confirmed by amino acid analysis, mass spectrometric measurement and peptide mapping. Circular dichroism measurement showed that the conformation of osteocalcin containing three Gla residues dramatically changed on addition of calcium ions, whereas the peptide containing glutamic acid at position 17 did not. These findings clearly show that the Gla residue at position 17 is essential for a calcium-dependent conformational transition of osteocalcin.
A DDD/Qdj strain of embryos was transferred to the same strain of recipient females to examine the effect of the embryo transfer procedure on the intrauterine growth of the mandible in mouse fetuses. Just after parturition, the litter size and the gestation period were recorded and the mandibular size of the newborn offspring was measured by use of an image analyzing system. The mandibular size of the newborn offspring developed from the transferred embryos was compared with that of the newborn offspring developed from the nontransferred embryos. The following results were obtained: 1) There was no gender difference in the mandibular size of the newborn offspring from either the transferred or nontransferred embryos. 2) An inverse relation between the litter size and the mandibular size of the newborn offspring was observed, while a direct relation between the gestation period and the mandibular size of the newborn offspring was observed. 3) The litter size in the transferred group was smaller than that of the nontransferred group, while the gestation period in the transferred group was longer than that of the non-transferred group. After adjusting for the effects of the litter size and the gestation period on the mandibular size for both groups, the adjusted mandibular size of the newborn offspring in the transferred group was significantly smaller than that of the nontransferred group. Thus, it is concluded that the embryo transfer procedure retards the intrauterine growth of the mandible in mouse fetuses developed from transferred embryos.
The embryo transfer technique is a very useful tool for determining the intrauterine effect of the dam on the prenatal growth of the embryo. In the present study, a DDD/Qdj strain of embryos was transferred to four strains of recipients (DDD/Qdj, C3H/Qdj, C57BL/Qdj, and DBA/1J Sea). The litter size and the gestation period were recorded and the mandibular size of the newborn offspring was measured by an image analyzing system. A comparison among the four strains of recipients was performed to examine the effect of the strain of the recipient on the intrauterine growth of the mandible in mouse fetuses. The following results were obtained. 1) There were no interstrain differences in the litter size and the gestation period among the four strains of recipients. 2) There was an inverse relation between the litter size and the mandibular size, while there was a direct relation between the gestation period and the mandibular size. 3) There was a strong effect of the strain of the recipient on the mandibular size of the newborn offspring. 4) After eliminating these effects of the litter size and the gestation period on the mandibular size, a significant interstrain difference in the adjusted mandibular size of the newborn offspring developed from the DDD/Qdj strain of embryos transferred to the four strains of recipients was found. It is suggested that the four strains of recipients might unequally affect the intrauterine growth of the mandible in the mouse fetuses, which were derived from the same DDD/Qdj strain of transferred embryos.(ABSTRACT TRUNCATED AT 250 WORDS)
To examine the degree of the relative contribution of genetic and environmental effects to preimplantation development of mouse embryo in vitro, two-cell stage embryos collected from oviducts of five strains of inbred mice (DDD/Qdj, C3H/Qdj, C57BL/6J Sea, DBA/1J Sea, and BALB/C Sea) were cultivated up to the stage of expanded blastocyst for 72 hr. Both fertility and survival rates were calculated in each recipient and also in each strain. A Student-Newman-Keuls test for both rates showed a significant inter-strain difference and an analysis of variance done to estimate the relative importance of genetic and environmental effects on the preimplantation development of embryo showed a low degree of genetic determination for both rates. It was thus possible to conclude that the environmental effect played a more important role on preimplantation development of mouse embryo in vitro.
Embryo transfer effect and intrauterine effect of the dam on prenatal development of the craniofacial complex of mice embryos were investigated with the use of embryo transfer and cephalostat. DDD strain embryos were transferred to the three strains of recipients (DDD, C57BL, and DBA). The cephalometric observation of newborn offspring developed from transferred embryos was performed just after parturition. Dorso-ventral craniofacial size of newborn offspring was calculated using values of X- and Y-coordinates on a dorsoventral cephalogram. Statistical analysis showed that a significant intergroup difference in craniofacial size between transferred and nontransferred groups as well as a significant inter-strain difference among those of the three strains of recipients were observed. Thus, it was disclosed that embryo transfer technique might retard the prenatal development of craniofacial complex of transferred embryo and that the three strains of recipients contributed unequally to the prenatal development of craniofacial complex of transferred embryo through each of their intrauterine environments as a prenatal maternal effect. These results indicated that the intrauterine environment of the recipient played an important role in the prenatal development of the craniofacial complex of the mice embryo.
The embryo transfer technique and cephalometry were used to investigate the effect of dam strain in intrauterine craniofacial growth and the severity of cleft lip and palate (CLP) in a CLP-susceptible CL/Fr strain of embryos. The CL/Fr strain of embryos at early blastocyst stage was transferred to the same dam strain and to the CLP-resistant C57BL dam strain. On the 18th gestational day, each dam was laparotomized to take out the fetuses. The spontaneous incidence of CLP in the fetuses was checked and a cephalometric observation of the craniofacial complex of each fetus was done just after laparotomy. The dorsoventral craniofacial size of the unaffected fetuses and the severity of CLP i the affected ones were compared between both dam strains. The following results were obtained: 1) The overall craniofacial sizes of the unaffected fetuses observed in the CL/Fr dam strain were significantly smaller than those seen in the C57/BL dam strain. Those of the affected fetuses observed in the CL/Fr dam strain were smaller than those seen in the C57BL dam strain although the interstrain difference was not significant. 20 The dam strain had a highly significant effect on the craniofacial size of the unaffected fetuses. 3) The CLP frequency in the CL/Fr dam strain was significantly higher than that in the C57BL dam strain. 4) The severity of CLP in the affected fetuses observed in the CL/Fr dam strain was significantly more serious than that seen in the C57BL dam strain. These results indicated that the CLP-susceptible CL/Fr dam strain retarded the intrauterine craniofacial growth of the fetuses and that the cleft condition in the affected fetuses observed in the CL/Fr dam strain was more seriously affected than that seen in the CLP-resistant C57BL dam strain. Thus, it can be concluded that the effect of the dam strain played an important role in the craniofacial morphogenesis of the CL/Fr strain of mouse fetuses that developed from the embryo transferred to the CL/Fr and C57BL dam strains along with the genotype of embryos.
The embryo transfer technique was carried out to examine the strain effect of dams on the intrauterine incisal growth of mouse fetuses. A mean of nine DDD/Qdj embryos was transferred to each female recipient of the four strains (DDD/Qdj, C3H/Qdjl C57BL/Qdj, and DBA/IJ Sea). The dam's weight, the litter size, the gestation period and the newborn offspring weight were recorded. The mandibular incisal size of the newborn offspring was measured two-dimensionally by means of an image analyzing system. Statistical analyses of the incisal size of the DDD/Qdj newborn offspring delivered from the four strains of recipients showed the following results: 1) There were significant interstrain differences in the dam's weight and the newborn offspring weight, but not in the litter size and the gestation period among the four strains of recipients. 2) There was an inverse relation between the litter size and the mandibular incisal size while there were direct relations between the dam's weight and the mandibular incisal size, and between the newborn offspring weight and the mandibular incisal size. 3) There was a significant strain effect of the dam on the mandibular incisal size of the newborn offspring. 4) After eliminating the effects of the litter size, the gestation period, and the newborn offspring weight on the mandibular incisal size of the DDD/Qdj newborn offspring developed in the four strains of dams, a significant interstrain difference in the adjusted mandibular incisal size was found (C3H/Qdj > DBA/IJ Sea > C57BL/Qdj > DDD/Qdj), suggesting that the uteri of the C3H/Qdj strain of dams provided a more suitable environment for the intrauterine incisal growth than those of the other three strains of dams. Thus, it is concluded that the strain effect of dam played an important role in the intrauterine incisal growth of mouse fetuses.
Although the influence of genetic and environmental factors on the completed crown size of mandibular molars in mice is well known, such influence on the growth process of the mandibular second and third molars of mice has not yet been clarified. The purpose of the present study is to examine the growth pattern of the dentinal formation and evaluate the relative contributions of both genetic and environmental factors to longitudinal dentin formation by the use of the partial diallel cross-genetic approach, the time-marking method and a computerized image measurement system. The following results were obtained: 1) the onset of dentinal formation in the second molar was on the 6-9th day after birth, while that of the third molar was on the 9-12th day after birth; 2) the best fitted growth curve of the dentinal formation for the first molar was the fifth order polynomial equation, while for the second molar the fourth order polynomial equation was best, and for the third molar the third order polynomial equation was best; 3) maternal effect strongly influenced the second and the third molar dentin growth at an early stage of postnatal growth. Thus, it could be concluded that the dentinal formation growth pattern differed among the three kinds of mouse molars while maternal environmental factors, in addition to genetic factors, played an important role in the mouse second and third molar dentin growth during the early stage of postnatal growth.
A cross-nursing experiment was conducted to examine the nursing dam strain effect on the postnatal growth of a newborn mouse offspring by simultaneously using larger DDD strain mice and smaller C57BL strain ones. A periodical cephalometric observation of the postnatal craniofacial growth of the offspring was longitudinally made from birth up to the 100th day of life in addition to measuring the offspring weight. According to multivariate statistical analyses, the following results were obtained: 1) The mean body weight of the DDD offspring cross-nursed by the C57BL dam was significantly lighter than that of the DDD offspring self-nursed by the DDD dam throughout the whole experimental period except at birth and on the 100th day. 2) The mean body weight of the C57BL offspring cross-nursed by the DDD dam was significantly heavier than that of the C57BL offspring self-nursed by the C57BL dam from the 10th day up to the 30th day. 3) There was a significant positive relationship between the offspring weight and the offspring craniofacial size throughout the entire experimental period in the C57BL offspring and from the 10th day up to the 40th day in the DDD offspring. 4) The nursing dam strain effect on the craniofacial size of the DDD offspring was also significant on the 30th, 60th, 80th, and 100th days. The adjusted craniofacial size of the DDD offspring cross-nursed by the C57BL dam was significantly smaller than that of the DDD offspring self-nursed by the DDD dam on the 30th, 60th, 80th, and 100th days. 5) The nursing dam strain effect on the craniofacial size of the C57BL offspring was not significant throughout the whole experimental period. The adjusted craniofacial size of the C57BL offspring cross-nursed by the DDD dam was almost the same as that of the C57BL offspring self-nursed by the C57BL dam throughout the whole experimental period. 6) The fat content of the DDD dam tended to be higher than that of the C57BL dam and the interstrain difference was closed to a significant level (P = 0.06) on the 20th day. The moisture content of the DDD dam tended to be lower than that of the C57BL dam and the interstrain difference was also significant on the 7th day (P < 0.001). Based on these findings, it can thus be concluded that the nursing dam strain effect played an important role in the postnatal somatic growth of the DDD and the C57BL offspring and the craniofacial growth and the DDD offspring.
The authors evaluated the basic performance of an interatrial shunt (IAS) made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in compliance with the amount of bronchial flow and the size of the IAS. The IAS of 4.4 mm diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in this IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5 mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4 +/- 1 mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. The authors conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system.
An artificial monozygotic twin mouse produced by bisecting a 16-cell stage embryo with a fine glass-needle and then transferring a pair of demi-embryos together into the right uterus of a pregnant recipient female mouse after a 24 hr in-vitro cultivation allowed us to examine the postnatal growth changes in monozygotic twin mice. With regard to the preimplantational growth process of the embryo, we investigated the success rate of bisecting an embryo into paired demi-embryos, the developmental ability of the bisected demi-embryo up to the early blastocyst, and the production rate of such monozygotic twin mice. The items examined in the postnatal growth process of the monozygotic twin mouse were the growth curve of the twin weight and the craniofacial size of the monozygotic twin mouse by cephalometric observations at the 3rd, 10th, 21st, 42nd, 70th, and 100th postnatal days, respectively. The following results were thus obtained. 1) The success rate of bisecting the 16-cell stage embryos into a paired demi-embryos was 86.1% (2,528/2,936). As a result, 2,301 of 2,528 paired demi-embryos could develop up to blastocysts after 24 hr of in-vitro cultivation (91.0%). 2) In addition 42 of the 394 (10.7%) recipient female mice, which had been transferred as paired demi-embryos and delivered a litter, resulted in 31 singleton mice (7.9%) or 11 paired monozygotic twin mice (2.8%), respectively. 3) The weight of each twin increased rapidly up to the 42nd day but thereafter only increased gradually up to the 100th day. The within-pair difference among each paired monozygotic twin mouse could be observed from after the 21st day until the 100th day. 4) Both the dorsoventral craniofacial size of each twin mouse and the lateral craniofacial size of each monozygotic twin mouse increased rapidly up to the 42nd day and thereafter gradually reached a plateau by the 100th day. Almost no within-pair difference was observed among each paired monozygotic twin mouse after weaning up to the 100th day. Based on these results, it is thus concluded that the craniofacial growth of each paired monozygotic twin mouse more closely resembled the growth pattern than that of the somatic growth, which thus indicated that the craniofacial growth was more greatly controlled by the genetic effect than the somatic growth. Furthermore, these findings thus suggest that an embryo bisection is an essential for producing artificial monozygotic twin mice from paired demi-embryos. Therefore, artificial monozygotic twin mice are considered to be a useful animal model for examining the effect of genetic-environment interaction on either the prenatal dento-craniofacial morphogenesis or the postnatal craniofacial growth in mice.