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Biomedical subjects

K Kamiyama

Publications and source records attributed to K Kamiyama.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Frequency of the developmental disturbances of tooth structure].

In permanent and deciduous dentitions, the frequency of congenitally missing teeth, supernumerary teeth, conical teeth, fused teeth, germinate teeth, abnormal tubercles (basal ridge of incisor or canine, central cusps of molars, Carabelli's cusp, protostylid, and para-molar tubercles), and enamel hypoplasia (white spots, pigmentation, and enamel defects) were surveyed. Furthermore, mesio-distal and bucco-lingual dimensions of the crowns were measured and the relationship between developmental disturbances of dental hard tissue and tooth size was examined. For the deciduous dentition, the frequency of children with congenitally missing teeth, conical teeth and fused teeth was 7.2%, 1.1% and 5.3%, respectively. Enamel hypoplasia appears with the following frequency; white spots (16.0%), pigmentation (6.4%), and enamel defects (5.2%). Mesio-distal widths of the upper canine and lower lateral incisors of the children with congenitally missing teeth was significantly smaller than the standard values. For the permanent dentition, congenitally missing teeth, conical teeth and fused teeth were detected in 5.7%, 3.0%, and 0.5% of the children, respectively. The frequency of children with basal ridge, central cusps, Carabelli's cusp, protostylid, and para-molar tubercles was respectively, 1.1%, 2.6%, 7.1%, 0.3% and 1.3%. Children with central cusps or Carabelli's cusp tended to have larger crowns, while children with congenitally missing teeth or conical teeth tended to have smaller teeth. As for enamel hypoplasia, white spots were detected in 24.9% of the children, and pigmentation was in 8.1%, and enamel defects were in 9.2%. These results indicate that abnormality of tooth number and tooth morphology correlate with the tooth size and this tendency is more striking in permanent dentition than in deciduous dentition.

Child↗
PubMed1990

[Clinical study of ectopic eruption of the permanent first molars].

The purpose of this study was to investigate the etiology and characteristics of the ectopic eruption of first permanent molars. The subjects were 35 cases (27 maxilla and 8 mandible) with ectopically erupted permanent first molars, which were recognized in 24 out-patients (10 boys and 14 girls) visiting Tohoku University, Dental Hospital. The materials used for the analysis were dental casts, X-ray lateral cephalograms and panoramic radiographs, and both materials of the ectopic and normal groups were compared. The results were as follows: 1) There were no significant differences statistically between the mesio-distal crown diameters of the maxillary permanent first molar, central and lateral incisor, and all deciduous teeth in ectopic group and their mean values in Ono's and Otsubo's studies. 2) There were no significant differences as compared to all parts of the size of the dental arch in ectopic sides with those in the normal sides of same individuals at IIA and IIC of Hellman's developmental stage in dentition. 3) When the sizes of the dental arch in the ectopic group were compared with those of the normal group, the former were smaller at the distance between the mid-point and the canine mesial surface (Fig. 1-4), the ridge of the posterior region of the basal arch and most distal point of the primary second molar (Fig. 1-6) at the Hellman's dental age IIA, while the canine distance to the midline (Fig. 1-1), the dental arch perimeter from mid-point to the distal surface of primary second molar (Fig. 1-4+5), and the distance between the canine and primary second molar, div. X (Fig. 1-7) at Hellman's dental age of IIC were significantly smaller than the latter. 4) Regarding the comparison of the value of the changes in dental arch size between the ectopic group and the normal group from Hellman's dental age of IIA to IIC, the distance between the canine and primary second molar, div. X (Fig. 1-7) decreased markedly and the distance between the ridge of the posterior region of the basal arch and the most distal point of the primary second molar (Fig. 1-6) increased. 5) Results of the analysis of X-ray lateral cephalograms showed that the angle of eruption of first molars in the ectopic group was significantly smaller compared with normal group. 6) According to the cluster analysis on the calcification of tooth germ using panoramic radiographs, similarity among all of the samples was lacking in the ectopic group, especially congenital missing of the second molars and second premolars in the ectopic side and the delayed calcification of the ectopically erupted teeth were found in maxilla.

Child↗
PubMed1990

[Evaluation of preventive dental care for first permanent molars in children].

The prevalence of dental caries in first permanent molars was measured in 220 children who have been under regular dental care at the Pediatric Dental Clinic, Tohoku University School of Dentistry. While the caries prevalence rate of first permanent molars reached approx. 50% five years after the eruption, the number of filled surfaces per restored tooth was less than 2.0. The caries prevalence of the permanent mandibular first molars was significantly higher than the caries prevalence of the permanent maxillary first molars. However, the occlusal surface showed no significant differences between the maxillary and mandibular molars. While comparing the female to male group, the caries prevalence rate was significantly higher and the peak of caries occurrence on every surface was earlier in the females. Pit and fissure sealants were applied to approx. 75% of first permanent molars and the occlusal caries were reduced as a result of sealing. When sealants were applied to the teeth diagnosed as C1, 50% were restored due to development of caries. This was a significantly higher rate than that applied to sound teeth. Our study indicates that most of the occlusal caries occurred in the earlier stage of 1-2 years after the eruption, before sealants were applied. The buccal fissure of the lower molars and the occlusal fissures both showed high caries prevalence. It was suggested that prevention of fissure caries immediately following eruption until the sealant is applied is an important issue in our present dental care system.

Child↗
PubMed1990

[Changes of the arch form and occlusion of the deciduous open bite cases: a longitudinal study].

The purpose of this study was to determine the characteristics and longitudinal changes of the arch morphology and occulusion of the deciduous open bite cases. The materials used in this study were the serial plaster casts of 40 Japanese children with deciduous open bite, and they were measured with the three dimentional system. The following results were obtained: 1. The form of dental arch with open bite in the early primary dentition changed remarkably in the maxilla but little in the mandible. In children with open bite, the maxillary intercanine distance was narrower, the maxillary arch length was longer, the palatal height of the front area was higher, but the back one was lower, and the upper central primary incisors were located more forward and upward higher than in children without open bite. 2. In the late primary dentition, the dental arch shape in the spontaneous closure group showed little difference from the control group. However the deciduous upper central incisors of the spontaneous closure group were very remarkably inclined to the palatal side, and the vertical over-jet was larger than that in the control group. The larger the horizontal over-jets were in the early deciduous dentition, the larger the vertical over-jet changed in the late deciduous dentition. 3. In the spontaneous closure group, the point of the dental arch showed a regular changing aspect, in which place marked variation was recognized in the early deciduous dentition as compared with the control group. Because of spontaneous closure, the dental arch shape approached the one of control group rapidly. 4. The result of multivariate analysis indicate that not only discontinuance of thumb-sucking but also many variables of the dental arch shape and occlusal condition may induce spontaneous closure of the open bite within the deciduous dentition term.

Child↗
PubMed1990

[Bronchopleural fistula after pulmonary resection of lung cancer].

From 1977 to 1988, 390 cases of lung cancer were resected in our hospital. In 12 patients (3.1%) a postoperative bronchopleural fistula developed. This complication occurred more commonly after right pulmonary resection than left and most common after right pneumonectomy. Moreover, that had occurred following right pneumonectomy was most fatal. After right middle and lower lobectomy, this complication occurred at the same rate as after pneumonectomy and also caused a fatal result. On the other hand, after the resection of single lobe, the rate of the occurrence of a bronchopleural fistula was lower. And, even if it had developed, the fistula sometimes could be healed by a conservative treatment only. In one of our cases the fistula was successfully treated by intra-bronchial gluing through a bronchofiberscope.

Aged↗
PubMed1989

Establishment of latent ganglionic infection with herpes simplex virus via maxillary gingiva and viral re-activation in vivo after trauma.

Herpes simplex virus can remain latent for months or years in sensory and automatic ganglia of animals and man, and can be re-activated in vivo by several procedures such as neurectomy, irritation of epithelial surfaces, and administration of immunosuppressive agents. The objective of this study was to determine whether dental stimuli can cause re-activation of the latent herpes simplex virus. Homogenization and explanation of ganglia from mice showed that herpes simplex virus (type 1) traveled from maxillary gingiva to trigeminal ganglia, and remained latent. It was also shown that mice passively immunized with rabbit antibody to herpes simplex virus, following the inoculation of herpes simplex virus by the maxillary gingiva route, developed a latent infection in the trigeminal ganglia. Neutralizing antibody was cleared from the circulation and could not be detected in most of these animals after five weeks. A neutralizing test showed that antibody-negative mice with latent infection were able to produce antibody to re-infection with herpes simplex virus, suggesting that re-activation can be identified by measurement of serum antibody. By use of this mouse model system, it was shown that when maxillary gingiva was traumatized with dry ice, viral re-activation occurred in 58% of these animals, as demonstrated by the appearance of neutralizing antibody. Irradiation by a Stomalaser beam had no effect on the re-activation of latent herpes simplex virus. Our mouse model system may serve as a useful model for obtaining new information on re-activating or inhibitory factors in dentistry.

Animals↗
PubMed1989

[Investigation into the actual condition of outpatients. I. The environmental and oral health status prior to and at the first visit. Comparison of the results between present study and last investigation].

The purpose of this paper was to investigate the actual status of environmental and oral health conditions prior to and at the first visit of the outpatients who visited the pedodontics clinic of Tohoku University Dental Hospital during the period from April 1981 to May 1986, and to compare them with the results of the same kinds of investigation carried out 10 years ago. The subjects were 895 children, with questionnaires being filled out by their mothers. The following results were obtained. 1) As to methods of nursing, breast feedings have increased, while bottle feedings have decreased. The weaning period of almost all of the children was a period between 3 and 6 months of age, as the same as found during the last investigation. 2) The number of children who had eating and drinking habits at bedtime decreased relatively compared with the last investigation. 3) The majority of the children ate between meals twice a day regularly, eating fruits, senbeis (rice crackers), potato chips, and drinking milk frequently. These tendencies in the present study were almost the same as the results of the last investigation. 4) The number of children brushing more than twice a day has been increased compared with the last investigation, and most of them have been brushing their teeth after breakfast and before going to bed. 5) About 87% of the mothers of the patients thought that dental caries are an illness, but 8.9% of them did not. 6) As to caries prevention at home, the majority of the mothers were concerned about tooth-brushing habits and eating habits between meals. In conclusion, this study indicated that concern about oral health of mothers has increased in recent years.

Attitude to Health↗
PubMed1989

[Investigation into the actual condition of outpatients. II. Correlation between the daily habits of eating and toothbrushing and the prevalence of dental caries incidence].

The purpose of this paper was to investigate the correlation between the daily habits of eating and tooth-brushing and the prevalence of dental caries in the outpatients who visited the Pedodontics Clinic of the Tohoku University Dental Hospital during the period from April 1981 to March 1986. The subjects were 877 individuals with questionnaires which the mothers had filled out. The following findings were obtained. 1) The dft index for children aged 1 year to 6 years in the present investigation was lower than that of the same age group investigated 10 years ago. 2) The dft indicies according to each feeding group were 8.86 in the bottle feeding group, 7.51 in the breast feeding group and 6.77 in the mixed feeding group. 3) The group in which the weaning period was late showed a significantly high dft index. 4) The dft index of the group taking beverages containing sugar before going to bed was significantly higher than that of the group without doing this. 5) The group of patients aged 2 years to 5 years who had between-meal snacks more frequently showed a high dft index. 6) The irregularity of the between-meal eating times caused a high tendency toward caries occurrence. 7) The group having between-meal snacks while playing showed a significantly higher dft index than that of the group having it at a table and not playing. 8) No relation was observed between the frequency of tooth brushing and the dft index.

Breast Feeding↗
PubMed1989

[Clinical evaluation of low viscosity composite resin].

This study was to evaluate clinically low viscosity composite resin. The subjects of the present study were 121 children aged 2 to 10 years who visited the Pedodontic clinic of Tohoku University Dental Hospital and 53 children aged 2 to 8 years who visited the clinic of the general practitioners in Sendai. A total of 451 cavities (343 at the clinic of the University Hospital, 108 at the clinic of the general practitioners) were treated with Clearfil SC-II (Kuraray). The observation period varied from 1 month to 33 months after treatment. The restorations were examined with regard to spacing or stepped abrasion in the marginal region of the fillings, fracture, loss, attrition and discoloration of the fillings, and recurrent caries and/or pulpal involvement of the treated teeth. The following findings were obtained. 1) The restoration cases treated at the clinic of the University Hospital were evaluated as clinically acceptable in 254 cases (74.1%), while those treated at the clinic of the general practitioners in 76 cases (70.4%). 2) Of the 343 restorations treated at the clinic of the University Hospital, 73 (21.3%) exhibited poor restorative conditions, while of the 108 restorations treated at the clinic of the general practitioners, 15 (13.9%) showed such conditions. 3) The incidences of poor restorative conditions for anterior restorations were 39.7% and 8.3% respectively at the clinics of the University Hospital and general practitioners. 4) The incidences of poor restorative conditions for posterior restoration were 16.9% and 17.7% respectively at the clinics of the University Hospital and general practitioners. 5) Among the poor restorative conditions, the spacing or stepped abrasion and recurrent caries in the marginal region of the restorations occurred more frequently. 6) The incidences of spacing or stepped abrasion and recurrent caries in the marginal region of the restorations increased in the cases of class II and III cavities.

Child↗
PubMed1989

[Clinical examination of resected cases of lung cancer with pleural dissemination].

Preoperative examination using chest computed tomography (CT) of cases with pleural dissemination and no pleural effusion revealed small disseminated nodules of the visceral pleura. However, chest CT could not exactly diagnose those of the parietal pleura. The indications of operation, especially pan-pleuropneumonectomy, for cases with pleural dissemination should be limited to the following cases; those in which no pleural effusion and no metastasis to the mediastinal lymphnodes has been clinically proved and in which it is not necessary to perform extensive combined resection other than pan-pleurectomy and partial resection of the diaphragm and/or pericardium. Well differentiated histological types of lung cancer are better indications for surgical treatment.

Adenocarcinoma↗
PubMed1988

Relation of supersensitivity to cerebral vasospasm induced by oxyhaemoglobin.

There have been reports that superior cervical ganglionectomy (SCG) is effective as a treatment for cerebral vasospasm following subarachnoid haemorrhage (SAH). On the other hand, denervation supersensitivity is supposed to play an important role in vasospasm. The two accounts contradict each other. To investigate this problem, various examinations were performed using the exposed basilar arteries of cats. We have accepted that oxyhaemoglobin (Oxy-Hb) is an important spasmogenic substance. Therefore, the change in vascular reactivity to Oxy-Hb was investigated after various kinds of denervations. It was confirmed that Oxy-Hb has no adrenergic receptor agonist properties because the Oxy-Hb inducing vasospasm was not suppressed by Prazosin or phenoxybenzamine. As a result of this, it is not likely that augmentation of Oxy-Hb inducing vasospasm is caused by deviation supersensitivity. Thus, the non-deviation supersensitivity became a topic of investigation. The basilar arteries were denervated by chemical treatment (reserpine, 6-hydroxydopamine) or bilateral SCG to examine the change in the reactivity to noradrenaline or Oxy-Hb. An increase in reactivity to noradrenaline was observed with the denervations. In contrast, no change in reactivity to Oxy-Hb was found. In conclusion, it was observed that deviation and non-deviation supersensitivity do not participate in vasospasm, in so far as vasospasm is caused by Oxy-Hb.

Animals↗
PubMed1988

Isolation of cDNA clones for mouse cytoskeletal gamma-actin and differential expression of cytoskeletal actin mRNAs in mouse cells.

We described the structures of mouse cytoskeletal gamma-actin cDNA clones and showed that there is strong conservation of the untranslated regions with human gamma-actin cDNA. In addition, we found that the expression levels of beta- and gamma-actin mRNAs are differentially controlled in various mouse tissues and cell types but are coordinately increased in the cellular growing state. These results suggest that there are multiple regulatory mechanisms of cytoskeletal actin genes and are consistent with the argument that beta- and gamma-actins might have functional diversity in mammalian cells.

Actins↗
PubMed1988

[Experimental cerebral vasospasm induced by oxyhemoglobin and the sympathetic nervous system (Part 1): Effect of alpha-adrenergic receptor blockers].

This study was performed as part of a series of investigations into the relation between cerebral vasospasm following subarachnoid hemorrhage and the sympathetic nervous system. We studied the effect of phenoxybenzamine chloride (POB) and prazosin hydrochloride (Prazosin) on the cerebral vasoconstriction in the basilar arteries of cats induced by application of oxyhemoglobin (Oxy-Hb), noradrenaline (Nor) and prostaglandin F2 alpha (PGF2 alpha). Adult cats were anesthetized with intramuscular pentobarbital and maintained on a respirator through a tracheostomy. By the transclival approach, a bone window was formed in the clivus, and the dura was opened, exposing the basilar artery. A cannule was inserted into the subarachnoid space, and through it, Oxy-Hb, Nor and PGF2 alpha were injected. The sequential changes in caliber of the basilar artery were measured using photography. First, we determined the doses of POB and Prazosin necessary for decreasing the vasoconstriction induced by Nor, and 20 mg/kg of POB and 10 mg/kg of Prazosin were found to decrease the vasoconstriction induced by 10(-3) M Nor, statistically. Second, we investigated the effect of 20 mg/kg of POB and 0.5 mg/kg and 10 mg/kg of Prazosin on the cerebral vasoconstriction induced by Oxy-Hb or PGF2 alpha. POB (20 mg/kg) was infused for 2 hours before the application of Oxy-Hb or PGF2 alpha. Prazosin was given intravenously. In the first group, 0.02% Prazosin (0.5 mg/kg) was administered intravenously for 1.5 hours before the application of Oxy-Hb or PGF2 alpha. In the second group, 1.5 hours elapsed between the beginning of Prazosin (10mg/kg) infusion and the application of Oxy-Hb or PGF2 alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1988

[Experimental cerebral vasospasm induced by oxyhemoglobin and the sympathetic nervous system (Part 2): An investigation into denervation supersensitivity].

UNLABELLED: The pathological mechanism of cerebral vasospasm following subarachnoid hemorrhage has not been well clarified until now. There have been reports that denervation supersensitivity in cerebral vessels occurring after subarachnoid hemorrhage may possible play a role in the appearance of cerebral vasospasm. On the other hand, we have accepted that oxyhemoglobin (Oxy-Hb) is an important spasmogenic substance. In the present study, we investigated the effect of chemical denervation (reserpine or 6-hydroxydopamine: 6-OHDA) and surgical denervation (bilateral superior cervical ganglionectomy: SCG) on the constrictive sensitivity of cat basilar arteries to noradrenaline (Nor) and oxyhemoglobin (Oxy-Hb) in situ. METHOD: Adult cats were anesthetized with intramuscular pentobarbital and maintained on a respirator through a tracheostomy. By the transclival approach, the basilar artery was exposed. A cannula was then inserted into the subarachnoid space, and through it, Oxy-Hb and Nor were injected. The sequential changes in caliber of the basilar artery were measured using photography. SCG was done 7 days before the application of Nor or Oxy-Hb and 14 days before application of Oxy-Hb. Pretreatment with reserpine was done as follows: 1 mg/kg of reserpine was injected subcutaneously once each day for 2 days. On the following day, the sensitivity of the basilar arteries to Nor or Oxy-Hb was assessed. Pretreatment with 6-OHDA was done as follows: 5 mg of 6-OHDA was dissolved in 1.0 ml of artificial CSF, and then injected into the cisterna magna. Seven days later, Nor or Oxy-Hb was applied. RESULTS: Pretreatment with reserpine tended to increase the vasoconstriction induced by 10(-7)-10(-4) M of Nor and the constriction induced by 10(-3) M of Nor was increased statistically (P less than 0.05). Cisterna magna injection of 6-OHDA tended to increase the vasoconstriction induced by Nor. SGG tended to increase the vasoconstriction induced by 10(-7)-10(-4) M of Nor and at a dose of 10(-3) M of Nor, the constriction of the basilar arteries was increased statistically (P less than 0.05). However, pretreatment with reserpine, 6-OHDA and SCG did not increase the vasoconstriction induced by Oxy-Hb. These results lead us to suggest that denervation supersensitivity does not participate in the vasoconstriction induced by Oxy-Hb.

Animals↗