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Biomedical subjects

K Kamoi

Publications and source records attributed to K Kamoi.

At least 73 records · Page 4Linked to original sources

[Clinical applications of Brånemark system implant in the Nippon Dental University Hospital. A 5-year report].

A clinical review was performed on patients who requested implantation and visited the Nippon Dental University Hospital during the five years from April 1985 to June 1990. This report describes patient characteristics and treatment results. 1. The total number of new patients was 127 (68 males and 59 females). Their ages ranged from 20 to 80 years. 2. The number of patients who were diagnosed with an indication for implantation and completed the 1st stage operation was 39 (30.7%). An additional 23 patients (18.1%) entered preoperative treatment and are waiting for their operation. Overall, implantation was indicated in 48.8% of all new patients. 3. The ages of patients at fixture installation ranged from 20 to 79 years (mean 60.54, S.D. 11.21) among the 39 patients (20 males and 19 females) who completed the 1st stage operation. As for the number of jaws, implantation was indicated in 40 jaws (21 in male patients and 19 in females). Maxillary implants were indicated in 8 jaws and mandibular implants were indicated in 32 jaws (1 male patient had indications in both jaws). 4. The total number of implanted fixtures was 198, of which 39 were installed in the maxilla, and 159 in the mandible (1 female patient was 5 mandibular fixtures installed at the University of British Columbia, Canada). 5. Of the fixtures implanted in 40 jaws, 94.9% of maxillary fixtures and 98.1% of mandibular fixtures remained stable after the 1st stage operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Role of prolactin in age-related change in serum dehydroepiandrosterone sulphate concentrations.

Serum dehydroepiandrosterone sulphate concentrations were measured in 70 patients with prolactinoma and in 54 patients with acromegaly with normal adrenocortical function. Compared with values in normal subjects of corresponding age, serum dehydroepiandrosterone sulphate levels were increased in 22 patients with prolactinoma (31%) and in 5 patients with acromegaly (9%). The four acromegalic patients who had elevated serum dehydroepiandrosterone sulphate levels had hyperprolactinemia. The mean serum dehydroepiandrosterone sulphate concentrations in patients with prolactinoma in each decade decreased with advancing age. There was a significant negative correlation between serum dehydroepiandrosterone sulphate concentrations and ages of the patients with prolactinoma. In all 8 women with prolactinoma as in 6 normal women, serum dehydroepiandrosterone sulphate levels declined definitely during the 9 years of follow-up despite persistent hyperprolactinemia. These results indicate that serum dehydroepiandrosterone sulphate levels are increased in a substantial number of patients with hyperprolactinemia, however, PRL per se may not play a significant role in the age-related change in serum dehydroepiandrosterone sulphate levels.

Acromegaly↗

[Study of regeneration in periodontal tissue after implantation of bone ceramic and collagen gel compound materials. Evaluation of histopathological finding and autoradiography].

The aim of this study is to determine the process of periodontal tissue regeneration and the metabolic activity of osteoblasts after implantation of bone ceramic and collagen gel compound materials (BC). Bone defects were artificially prepared in the alveolar septa of the bilateral upper first and second molars of Wistar rats. Subsequently, BC were implanted into the defective sites on the left side, and the gingival flaps were closed. At the defective sites on the right side, as a control, gingival flaps were closed without implantation. Rats were sacrificed 1, 3, 5, 7 or 14 weeks after implantation, and prepared tissue sections were observed both pathologically and autoradiographically using 3H-Proline. The results obtained were as follows: Pathological Findings One week after BC implantation, inflammatory cellular infiltration of the surrounding gingival connective tissue was relatively mild. Three weeks after implantation, BC were present in fibrous connective tissues, and some directly bound to the marices of regenerated bone. Observation 5 weeks after implantation revealed that BC had become embedded in the regenerated bone matrices and that there was giant cell reaction to foreign bodies at the margin of BC located in connective tissue. BC were directly bound to the regenerated bone matrices without intermediary fibrous tissues 7 and 14 weeks after implantation. Connective tissues showed high grade regeneration of collagen fiber bundles, in an arrangement that tended to be fixed in mesial and distal directions. Autoradiographic Findings There was no uptake of 3H-Proline into the regenerated bone matrices or the gingival connective tissue surrounding BC, while uptake of 3H-Proline into the entire area around the root apex and in the vicinity of the alveolar septum was observed with time (weeks) after BC implantation. These results suggest that BC provide nuclei for bone regeneration through inclusion in newly-generated periodontal bone tissue, although it is difficult to produce definite induction of bone tissue by BC alone. It is also apparent that these are useful bone implantation materials for restoration of the physiological morphology of alveolar bone in periodontal surgical treatment.

Animals↗

[Application of local drug delivery system to periodontal therapy. 4. Comparison of the therapeutic effects of administration of a TC film or root debridement on human periodontal disease].

In 8 patients with periodontal diseases under good supragingival plaque control, 22 test teeth each having a pocket not more than 4 mm deep were treated respectively with 3 consecutive administrations of tetracycline immobilized cross-linked collagen film (TC film) at intervals of 1 week, with onceroot planing and with both of these. The therapeutic effects were compared both clinically and micro biologically. The results revealed improvements in clinical symptoms such as reduction in the depth of the pocket, bleeding on pocket probing and the like for each treatment group in 6-12 weeks. The second and third groups also showed remarked gingival recession. Further more, the density of intrapocket microorganisms showed a remarked decrease up to the 8th week for each treatment group and the population of spirochetes showed a decrease up to the 6th week for the first treatment group and up to the 8th-12th week for the second and third treatment group. The results show that both local application of the TC film and root planing are effective in periodontal treatment, but not the combined treatment.

Collagen↗

[Chemiluminescence and phagocytic reactions of human nuclear leukocytes incubated with Streptococcus sanguis].

This experiment was designed to determine the role of indigenous organisms in gingival inflammation of the oral cavity, The test bacteria consisted of 3 strains of Streptococcus sanguis isolated from plaque at the gingival margin and grown in sure culture. These strains were subsequently designated as A, B and C. Peripheral nuclear leukocytes were isolated from 5 test subjects with clinically healthy gingiva. Luminol-dependent chemiluminescence and phagocytic functions of the 3 strains were measured, with the following results obtained. The mean peak value of luminol-dependent chemiluminescence following stimulation for strain A was 80.8 in the presence of serum, 38.8 in the presence of inactivated serum, and 20.5 in the absence of serum. For strain B it was 82.3 in the presence of serum, 6.4 in the presence of inactivated serum, and 2.5 in the absence of serum. For strain C it was 68.1 in the presence of serum, 65.3 in the presence of inactivated serum, and 8.3 in the absence of serum. In the absence of plasma strains A and B showed slight phagocytosis. In strain C, however, no phagocytosis was noted. In the presence of inactivated serum phagocytosis was increased strains A and B, but no phagocytosis was noted in strain C. In the presence of blood. phagocytosis was increased in strains A and B, but no phagocytosis was noted in strain C.

Dental Plaque↗

[Immunohistological study of wound healing in periodontal tissue of rats. Distribution of fibronectin and laminin after flap operation].

This study describes the distribution of fibronectin and laminin in periodontal tissue of rats after a flap operation. After full thickness flaps were raised, the roots were surgically exposed and planed. Animals were sacrificed at 12 hours, and 1, 3, 5, 7, 14, 28 and 56 days after the wounding. The block specimens were fixed in formalin, decalcified with EDTA, made into serial paraffin sections, and examined after hematoxylin and eosin staining, after Masson-trichrome staining and by indirect immunofluorescence for the presence of fibronectin and laminin. After the wounding, fibronectin was detected in the fibrin clot, and the migratory epithelial cells crossed over this fibrin clot (12 hours-5 days). Fibronectin was deposited heavily in the granulation tissue. When the gingival connective tissue had matured, fibronectin diminished (5-14 days). On the root surface, a layer of fibronectin was present in the region where connective tissue fibers were oriented parallel to the root surface, while no fibronectin was seen at the site of reattachment of the regenerated collagen bundle (14-56 days). Laminin was present in the basement membrane of normal epithelium and blood vessels, but was absent from the internal basal lamina. After the wounding, laminin was absent from the basement membrane zone of the distal site of the migrating epithelium (1-3 days). Upon completion of wound reepithelialization at 5-7 days after wounding, laminin reappeared throughout the basement membrane except the internal basal lamina. These results suggest that fibronectin may be important in the regeneration of epithelium, connective tissue and connective tissue attachment during repair by functioning as an extracellular provisional matrix for migrating cells. On the other hand laminin may be important in maintaining the normal epithelium.

Animals↗

[Histopathological study on qualitative changes in gingival collagen fibers for experimental periodontitis in rats. Remodeling of type I and III collagens detected by the Picrosirius-polarization method].

The objective of this study was to demonstrate the movement of type I and III collagens accompanying gingival inflammatory destruction. Experimental marginal periodontitis was induced by a calculogenic diet and a high-sucrose diet with feces in 3-week-old Wistar rats. We observed the changes in the interdental periodontium histopathologically by using the picrosirius-polarization method and an electron microscope. 1. After 5 weeks of eating the calculogenic diet, mild gingivitis was found. A small number of inflammatory cells consisting of neutrophils were seen. At the 2nd week, a variety of bone resorptions of alveolar crests began to appear. At the 10th week, an epithelial downgrowth was observed. At the 64th week, migration of epithelial attachment to half of the apex and a high degree of inflammatory cell infiltration of plasma cells could be seen. 2. Observations under the polarization microscope showed that interdantal horizontal fibers became coarse and type I collagen decreased but at the middle type III increased. However when the horizontal fasciculus were newly formed, type I was always dominant. Between interdental horizontal fibers and the alveolar crest, type III was increased. 3. Under the electron microscope microfibrils were found around adjacent degraded fibroblasts at the locations where collagen fibrils were destroyed and disappeared. In contrast, at the locations detached from inflammatory cell infiltration small bundles of microfibrils were seen. It is suggested that at the areas of destructive collagen structures the relative increase in type III and the appearance of microfibrils were caused by the reduction of type I. At the same time at the sites of detachment from the lesions, complete growth of type III and the appearance of microfibrils were found and were considered to be newly formed juvenile collagen structures. Moreover it is concluded that a balance proceeds with the qualitative changes in the types of collagen fibers involving breakdown and new formation.

Animals↗

[Examination of periodontal disease with gingival crevicular fluid. Correlation between capacitance and clinical findings].

An intimate relationship between the inflammatory state of the gingiva and the amount of gingival crevicular fluid (GCF) is well known. For the measurement of the volume of GCF, filter paper has been used in the past. In the present study, an electrostatic capacity measuring apparatus with sensor that is insertable into gingival sulcus was fabricated. Capacitance of GCF was measured in patients with periodontitis and the following results were obtained. 1. The measuring apparatus was controlled by a personal computer to obtain the data every 0.1 second. As the GI increased at the site of measurement, higher values were obtained, with longer persistence of the trend of increase in the measured value. 2. In view of the stability of the measured values, the amount of GCF appeared to be best expressed as the value obtained after 10 seconds. 3. The correlation between the capacitance and the clinical findings was evaluated at 500 sites. The correlation was the highest in GI followed by P1I, GBI and PD, suggesting the utility of this method in the detection of initial gingival inflammation.

Electrolytes↗

[Cytotoxicity of povidone-iodine on cultured mammalian cells].

Cytotoxicity of povidone-iodine on cultured mammalian cells was studied using cultured Chinese hamster lung cells (V 79 cells). Treatment of V 79 cells with povidone-iodine at 100-500 micrograms/ml for 24 to 72 hr induced a growth inhibition of the cells in a dose-dependent manner. Although minimum inhibition of survival of V 79 cells was elicited in cultures treated with povidone-iodine at 100-300 micrograms/ml for 2 to 24 hr, treatment at 500 micrograms/ml for 6 to 24 hr resulted in decrease in cell survival in a treatment time-dependent fasion. Exposure of cells to povidone-iodine at 100-500 micrograms/ml for 2 hr caused inhibition of DNA, RNA or protein synthesis of cells up to 13.9% of untreated cells. These results indicate that cytotoxicity of povidone-iodine occurs in dose- and treatment time-dependent manners and that povidone-iodine induces inhibition of DNA, RNA and protein syntheses of cells, even by the treatment which causes no reduction of cell survival.

Animals↗

[Maintenance care for dental implant].

Dental implant has tried at the early stage in 19th century recovering an oral function and esthetics. Technological revolutions in biochemical and new materials have developed on the remarkable change in the dental implants, nowadays we call the three generation therapy for dental implantology. There are many kinds of methods and techniques in dental implants, however a lot of troublesome complication on the process of surgical phase, construction of prothodontics and prognosis of maintenance care. In the proceedings of this symposium, I would like to propose you how to manage the maintenance care for various kind of dental implants through the methodology and case presentations. Tendenay and future for dental implants The current outlook of dental implant has increasing supply and demand not only dentists but also patients. According to Japanese Welfare Ministry's report in 1987, average missing teeth over sixty years old generations are approximately 42% in accordance with NIDR (U.S.A.) research. They are missed on ten over teeth in full 28th teeth dentitions owing to dental caries and periodontal diseases. Generally speaking, latent implant patients are occupied on the same possibility of needs for dental implants both Japan and U.S.A. Management of maintenance care The patients hardly recognized the importance of plaque control for the maintenance care in the intraoral condition after implantation. Dentists and dental staffs must be instruct patients for importance of plaque removal and control, because they already had forgotten the habit of teeth cleaning, especially in the edenturous conditions. 1) Concept of establishment in oral hygiene. Motivation and instruction for patients include very important factors in dental implants as well as in periodontal diseases. Patients who could not achieve on good oral hygiene levels obtained no good results in the long term observations. To establish good oral hygiene are how to control supra plaque surrounding tissues with patient himself. Ultimate concept of implantology have supported common concordance with periodontal therapy. 2) Patients consent and co-operation the right of informed consent, agreement to treatment by the patient has been gaining increased importance to implantology. Even the patient has consent, they must co-operate the process of dental implant with co-therapist (Fig. 2). 3) The clinical examination of clinical parameters in dental implants. (1) Plaque Index (Silness & Loe 1964) and Plaque Control Record (0 Leary 1978) (Table 5). (2) Gingival inflammation (Fig. 3). Ordinarlly, Gingival Bleeding Index (GBI Ainamo & Bay 1975) and Papilla Bleeding Index (Saxer & Jühlemann 1975) are used. (3) The depth of peri-implant sulcus with the plastic probe. (NDU style) (Fig. 4).(ABSTRACT TRUNCATED AT 400 WORDS)

Dental Implants↗

Improvement of immunologic abnormalities associated with hyperthyroidism of Graves' disease during methimazole treatment.

In an attempt to study the effects of methimazole treatment on immunologic abnormality of hyperthyroidism of Graves' disease, TSH receptor antibody (TRab), anti-DNA antibody and HLA-DR were measured in untreated patients with hyperthyroidism of Graves' disease and treated patients with methimazole for 2 years, using peripheral blood. In untreated patients, all 3 parameters elevated above normal. Three parameters decreased 2 years after methimazole treatment, but the magnitude of decrease was more in T3-suppressible patients than in T3-unsuppressible patients. However, both anti-DNA antibody and HLA-DR were significantly more in T3-suppressible patients than in normal subjects. It is suggested that immunologic abnormalities should largely be improved before remission of Graves' disease can be obtained.

Adolescent↗

Cardiac rhabdomyoma. A case report with reference to atrial natriuretic peptide.

An autopsy case of cardiac rhabdomyoma in a male infant is reported. Many nodules of rhabdomyoma were present in all four cardiac chambers and were microscopically composed of ovoid, glycogen-laden cells and typical "spider cells". Atrial natriuretic peptide (ANP) was immunohistochemically demonstrated in both normal myocytes and rhabdomyoma cells of both atria, but not in normal myocytes and rhabdomyoma cells of both ventricles. Ultrastructurally, atrial specific granules were present in atrial rhabdomyoma cells and normal atrial cardiocytes, and these showed ANP immunoreactivity with protein A-gold technique. It could be said that the localization and intracellular distribution of ANP in this cardiac rhabdomyoma were closely similar to those of normal human heart. With regard to the presence of ANP, cardiac rhabdomyoma cells arising in atria seemed to differ from those in ventricles, although many tumor nodules occurred in both atria and ventricles. Furthermore, it seemed that cardiac rhabdomyomas could also be divided into two parts: 1) an atrial part with ANP, and 2) a ventricular part without ANP. Therefore, this study confirms the hypothesis that cardiac rhabdomyoma is a hamartoma rather than a true neoplasm.

Atrial Natriuretic Factor↗

Studies of thyroid function and immune parameters in patients with hyperthyroid Graves' disease in remission.

The natural course of hyperthyroidism due to Graves' disease after discontinuation of antithyroid drug therapy was studied in 184 patients who had been treated with methimazole and whose thyroid function was suppressible with T3 when methimazole was discontinued. The patients were followed after discontinuation of therapy for up to 60 months. Serum T4, free T4 (FT4) and T3 levels, TSH receptor antibody (TRab) and anti-DNA antibody titers, and the percentage of HLA-DR positive lymphocytes in peripheral blood were measured serially. TRab and anti-DNA antibody tests were positive in the majority of patients before treatment and were negative in most at the end of treatment. Twenty-three (12.5%) patients had a recurrence of their hyperthyroidism, which occurred a mean of 20 months after withdrawal of methimazole; they are designated as having overt recurrent hyperthyroidism (group A). In these patients, serum T4, FT4 and T3 concentrations increased rather abruptly to markedly elevated levels in a several-month period and the TRab and anti-DNA antibody titers increased markedly at or shortly after recurrence in the majority. In 9 patients (4.1%), TRH-induced TSH secretion became totally suppressed, indicating the reappearance of thyroidal autonomy; however, the patients did not have any hyperthyroid signs and symptoms (subclinical hyperthyroidism; group B). Their serum T4 and FT4 concentrations fluctuated in the upper normal to slightly supra-normal range, and their serum T3 concentrations remained within the normal range throughout the follow-up period, but their TRab and anti-DNA antibody titers did not appreciably increase. Thus, the time of recurrence could not be precisely determined in group B. In the remainder (152 patients; 83.4%), serum thyroid hormone levels and TRH-induced TSH secretion remained normal, TRab and anti-DNA antibody titers remained negative, and hyperthyroidism did not recur (euthyroid remission; group C). At the time of final examination (in groups B and C) or at the time of recurrence (in group A), the percentage of HLA-DR positive peripheral lymphocytes was 17.9% in group A, 15.9% in group B, and 12.1% in group C. Retrospective analysis of the data indicated that the mean pretreatment TRab titer (percent inhibition of TSH binding) was slightly but not significantly lower in group C (37.8%) compared to those in group A (53.9%) and group B (54.8%). The 3 groups were indistinguishable by all other laboratory data both before treatment and at the time of the T3 suppression test. These data strongly indicate heterogeneity among patients with hyperthyroidism due to Graves' disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Plasma atrial natriuretic peptide in states of altered thyroid function.

To examine a possible role of atrial natriuretic peptide (ANP) in water and electrolyte disturbances associated with thyroid disorders, plasma ANP levels were studied in patients with hyper- and hypothyroidism. In 5 of the 21 hyperthyroid patients, including two patients with atrial fibrillation and two patients with mild cardiomegaly, the plasma ANP concentration was increased when compared to normal subjects. After treatment with methimazole or propylthiouracil, the plasma ANP concentration fell to normal in 4 patients, while it remained high in one patient who had persistent atrial fibrillation. No significant correlation was found between plasma ANP and the heart rate in untreated hyperthyroid patients. Plasma ANP was within the normal range in all 8 patients with hypothyroidism. During treatment with T4, the plasma ANP concentration increased in 6 of the 7 patients. Chest X-ray films and ultrasonic echocardiography demonstrated pericardial effusion in 4 of these patients before therapy. A weak but significant correlation was found between the plasma ANP and T4 concentration, and between plasma ANP and free T4 in hyper- and hypothyroid patients before and after treatment. These results indicate that abnormalities in ANP dynamics in thyroid disorders may probably be caused by hemodynamic changes resulting from a thyroid hormone excess or deficiency.

Adolescent↗

Effects of plasma volume and osmolality on secretion of atrial natriuretic peptide and vasopressin in man.

To clarify the role of blood volume and osmolality in the mediation of the release of atrial natriuretic peptide (ANP) and to examine the relationship between plasma ANP and plasma AVP levels in man, the effects of hypertonic saline and hypertonic mannitol infusion, and of water load on plasma levels of ANP and AVP were studied. Infusion of 5% saline to 7 healthy men at a rate of 0.05 ml.min-1.kg-1 for 2 h resulted in a parallel rise in plasma sodium, osmolality, plasma ANP and plasma AVP, indicating that plasma hyperosmolality stimulates secretion of both ANP and AVP. Infusion of 20% mannitol to 6 healthy men at the same rate resulted in a parallel increase in plasma osmolality, plasma ANP and AVP, whereas plasma sodium decreased, indicating that plasma hyperosmolality stimulates secretion of both ANP and AVP. Water load (20 ml/kg) into 7 healthy men produced a prompt and parallel fall in plasma sodium, plasma osmolality and plasma AVP. In contrast, plasma ANP and plasma volume, calculated from the changes in hematocrit, increased concomitantly, which indicates that expanded plasma volume stimulates secretion of plasma ANP. These results suggest that secretion of ANP in man is regulated principally by plasma volume, which may be modulated by a change in plasma osmolality. AVP secretion, on the other hand, is controlled mainly by osmotic change and secondarily by plasma volume.

Adult↗