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Biomedical subjects

N Shimozato

Publications and source records attributed to N Shimozato.

9 recordsLinked to original sources
PubMed1992

Vascularization after pulpotomy.

The vascular changes of the pulpal vessels in experimentally induced pulpotomy in dog tooth were investigated using microcorrosive resin casts technique and scanning electron microscopic examination. The pulpal tissues of the permanent mandibular molars were amputated and then dressed with calcium hydrate. At one to eight weeks after pulpotomy, the experimental teeth were prepared for resin casts of pulpal vessels with hard tissues. One week after pulpotomy, a concave region, which was supposed to be due to the compression by the calcium hydrate, was found in the newly formed pulpal vascular network. Around the concave region was a flat, dense capillary network. In eight weeks, the thick dentin bridge was formed in close proximity to the amputated pulpal surface. The vascular network just beneath the dentin bridge changed into similar features in the three layers of the normal pulpal vascular architecture, which are (i) terminal capillary network (TCN), (ii) capillary network (CN), and (iii) venular network (VN) and which distributed in the superficial layer of the pulpal vessels.

Animals↗
PubMed1989

Vascular architecture of cat pulp using corrosive resin cast under scanning electron, microscopy.

Vascular casts of cat premolar pulps in various stages of growth were made by injection of low-viscosity resin into the pulpal blood vessels. Examination under a scanning electron microscope revealed that, in the young pulp, the main arterioles ascend in the center of the pulp and venules run along the side of the root canal space. The subodontoblastic vascular plexus of the pulp could be distinguished by its characteristic three layers: 1. the terminal capillary network located in the odontoblastic layer; 2. a second layer of the capillary network which is composed of pre- and postcapillaries running parallel to each other; and, finally, 3. the venular network which has a lattice type appearance. The pulp cavity is reduced in size with age (maturation stage), in which the characteristic three vascular layers are changed into a one-layer coarse terminal capillary network which converges directly with the main venules. At this stage the blood vessels, especially the main venules, are also fewer in number.

Animals↗
PubMed1989

[Three dimensional study of the pulpal vascular changes during inflammation].

In this study, the changes of canine pulpal vascular architecture, at various stage of growth when subjected so acute and chronic inflammation were examined through a scanning electron microscope using vascular corrosive resin casts. The following results were obtained. 1. The sites of leakage of MMA resin out of the blood vessels coincided with the site where microleakage occurred, thus suggesting that resin cast method is a useful technique to study the area where vascular permeability was increased. 2. In an acute inflammation, leakage of resin out of blood vessels was mainly observed at the sites of venular network (VN) and venous capillaries, and these could be discriminated by use of the casts method. This is in accordance with the result by Tsuchiya, Magino and Palade, where they showed that vascular permeability was preferentially observed in venule and venous capillaries. 3. In pulp with a lesser number of venules during the stage of late maturation, leakage of resin was observed from those surviving venules to the bundle of main blood vessels. 4. Leakage of resin was not observed in the terminal capillary network (TCN), but in the capillary network (CN) and VN, especially just beneath the dentin, where cavity preparation with a water spray was performed. Accordingly, the generation of heat during cavity preparation was thought to be the main reason for disturbance of the pulp. 5. Severe case of suppurative and chronic ulcerative pulpitis were generated within one week after cavity preparation. The vascular architecture was characterized by a dense granular capillary network facing the ulcerative surface. 6. One week after pulpal exposure, at the stage of early maturation of pulp, the granulated blood vessels located within the exposed pulp had a tendency to shift to a pulp polyp. And the granulated blood vessels after two months showed a pulp polyp. 7. At the late maturation stage of pulp, development the pulp chamber and dentin tubules were saturated by resin cast method, suggesting the possibility of leakage out of blood vessels and the death of some odontoblasts. The pulp at this stage shifted to a gangrous pulp. 8. In conclusion, the pulpal vascularity constantly undergoes morphologic changes incidential to various condition such as growth, maturation and inflammation. Basically, vascularity of dental pulp consists of three major layers, that is TCN, CN and VN. When it comes to the maturation stage, owing to the apposition of secondary dentin, the pulp cavity will become narrow and the vasculation within it will undergo a histologic change. As a result, most of the VN disappears.(ABSTRACT TRUNCATED AT 400 WORDS)

Dental Pulp↗
PubMed1979

Use of curves for prediction of maternal blood levels of placenta-specific substances for diagnosis of placental function.

Maternal blood levels of cystine aminopeptidase (CAP), human placental lactogen (HPL) and beta 1 glycoprotein (SP-1) were predicted and evaluated using the expressions and their charts developed by us to help diagnosis of placental function in women of the third trimester of pregnancy. This study was conducted on the assumption that these placenta-originating substances as markers would behave similarly to the previously reported heat-stable alkaline phosphatase (HSAP). The results realized the following features: (1) CAP, HPL and SP-1, like HSAP, had their normal ranges of values too wide to be based on for diagnosing placental function in general, but it was confirmed that on the individual basis these marker substances could develop adequate "prediction curves" for their values to come well answering to the test in the same way as with HSAP. (2) The expressions for predicted values revealed that these marker substances in their shift in the maternal blood had different critical points start of deviation from exponential rising. Particularly in abnormal pregnancy, their shifting patterns were often dissimilar to one another, with implications that impaired placental function could possibly be confirmed qualitatively by reference to the predicted curve for the values of either of the marker substances.

Aminopeptidases↗
PubMed1978

Diagnosis of placental function by prediction curves for heat-stable alkaline phosphatase (HSAP).

In order to establish an effective diagnostic method for placental function using HSAP, the authors formulated two expressions to predict HSAP values for their rise before 38.7 weeks of gestation and declining after that; loge y = 1.03a-3.37 + 0.123x (i), and y = Y (1 + d/100( (ii), respectively. Further they prepared a chart of curves for these predicting expressions. The results obtained are as follows: (1) In normal pregnancies the deviation of prediction from measured values of HSAP was +/- 15% in 94% of the cases examined. (2) Many of cases of abnormal pregnancy showed a low level of HSAP, -15% or lower, and abnormal signs in HSAP pattern were found several days or weeks prior to the onset of fetal troubles. (3) Prolonged pregnancy with fetal troubles was able to be distinguished from "false" prolonged pregnancy. (4) In two consecutive pregnancies in the same woman, the courses of HSAP were strikingly consistent as far as both pregnancies were normal. The last fact suggests that the placental production of HSAP and its release into the maternal blood may be influenced by the individual constant a in expression (i). (5) It is recommended that the HSAP prediction curve is worthy to use as an easy screening method for placental function in the third trimester of pregnancy.

Alkaline Phosphatase↗