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Biomedical subjects

T Iwata

Publications and source records attributed to T Iwata.

At least 271 records · Page 15Linked to original sources
PubMed1990

[Tetanus antitoxin levels in various Japanese age groups in 1989].

The nationwide DPT vaccine program was started in 1969 for infants under 12 months of age. In order to estimate the tetanus immune status among the general population of various age groups, we measured the serum tetanus antibody level in randomly selected outpatients from Metropolitan Tokyo (n = 211, 6 months-60 years) and Hamamatsu, a city of 510 thousand population (n = 128, 3 years-80 years) between January 1987 and June 1989. Among the 211 subjects from Tokyo, the antibody value exceeding effective level of 0.01 HAU/ml was observed in 102 subjects (48.3%). The antibody positive rate was 90.8% in subjects of 3 to 21 years and was 27.7% in subjects of 22 years or older. The positive rate was significantly higher in subjects of 21 years or younger (p less than 0.005). Among 128 subjects from Hamamatsu, 60 (46.1%) had a positive antibody and the antibody positive rare was 96.9% in subjects of 3 to 21 years and was 29.5% in subjects of 21 years or younger (p less than 0.005). The above findings indicate that our DPT vaccination program has been functioning well for the last 20 years and that the immunized population is adequately protected against tetanus.

Adolescent↗
PubMed1990

[Diphtheria antitoxin levels in Japanese adults (10-20 years after the last vaccination)].

The serum diphtheria antitoxin levels in Japanese adults were investigated and the persistence of diphtheria toxoid effect was evaluated. The subjects consisted of 56 volunteers (20-31 years of age) who had received regular inoculations of diphtheria and pertussis vaccine (I and II or III phases). They had been immunized according to the Vaccination Law (old version) revised in 1958. The length of time after the last inoculation of diphtheria toxoid was speculated to range from 10 to 20 years. Serum diphtheria antitoxin was determined by passive hemagglutination method. Antitoxin level was 0.025 HAU/ml in 1 subject (1.8%), 0.05 in 2 (3.6%), 0.1 in 2 (3.6%), 0.2 in 8 (14.3%), 0.4 in 7 (12.5%), 0.8 in 12 (21.4%), 1.6 in 7 (12.5%) and more than 1.6 in 17 (30.4%). Results indicated that 55 of 56 (98.2%) possessed a higher level than the prophylaxis standard (0.05 HAU/ml). Since the current Vaccination Law prescribes a lower amount and fewer inoculations than the old law, the number of adults possessing prophylactic antitoxin level may decrease in the future. Further investigation of antitoxin level in adults needs to be continued.

Adult↗
PubMed1990

[Efficacy of acellular pertussis vaccine].

An outbreak of pertussis occurred in one room of a residential facility where 19 children aged 5 to 36 months were residing. They were prospectively surveyed to estimate the efficacy of acellular pertussis vaccine. Among the 19 residents, 9 were immunized with acellular pertussis vaccine. Among the 19 residents, 9 were immunized with acellular DTP vaccine and 10 were unimmunized. The spread of pertussis was surveyed bacteriologically and serologically for 2 months. Among the 9 immunized, 7 children acquired the laboratory-confirmed pertussis and 1 of the 7 developed the typical symptoms (whooping or paroxysmal coughing attack lasting for 14 days or more). Among the 10 unimmunized, 7 children acquired the laboratory-confirmed pertussis and 6 of the 7 developed the typical symptoms. There was no difference in the rate of secondary infection (7/9:7/10), but there was a significant difference in the rate of development of the typical symptoms (1/7:6/7 p less than 0.05). The point estimate of protective efficacy of the acellular DTP vaccine against typical pertussis was (6/10 - 1/9)/(6/10) x 100 = 81%. It was concluded from these findings that acellular DTP vaccine could not prevent the infection of Bordetella pertussis, but could prevent the development of the typical symptoms.

Child, Preschool↗
PubMed1990

An electron microscopic study of ectomesenchymal contacts in rat incisors.

In order to clarify connections between epithelium and mesenchymal tissue in the early stage of odontogenesis, the formation of ectomesenchymal contacts and the presence of coarse-textured material at the interface between ameloblasts (AMs) and odontoblasts (ODs) on growing rat incisors were studied by electron microscopy. The presecretory zone was classified into five regions according to the ultrastructure of each preameloblast (PA). The region where collagen fibrils could be observed was designated PZ-2, the region where predentin existed PZ-3, the region where the basal lamina began to disappear PZ-4, and the region where the basal lamina had disappeared PZ-5. In PZ-2, the cytoplasmic processes of PAs penetrated the basal lamina and reached the dental papilla cells. In some locations, ectomesenchymal contacts were also observed, in which the cytoplasmic processes of the PAs were in contact with those of the preodontoblasts (POs). In PZ-3, the distal cytoplasm contained large amounts of type-1 vesicles, and secretory granules. In the distal membrane of the PA, membrane invaginations containing fibrillar structures were visible. Also in some areas, the cytoplasmic processes at the distal ends of the PAs invaded the predentin. In the predentin, a large amount of coarse-textured material, considered to be the precursor of the enamel matrix, was observed. In PZ-3, a large number of cytoplasmic processes extended into the predentin, while in PZ-4, microvillus-like processes extended from the distal ends of the PAs, showing a high frequency of ectomesenchymal contact. It was suggested that secretory activity of the PAs was induced after ectomesenchymal contact had been accomplished, but that the PAs did not undergo morphological change into secretory ameloblasts.

Ameloblasts↗
PubMed1990

[Orthodontic treatment of adults with periodontal disease].

Orthodontic treatment has diversified in recent years along with progress in other dental specialties. Adult orthodontic treatment has become more popular as patients appreciate the need for a higher level of oral health accompanied with progress in orthodontic objectives and treatment methods. At the same time, patients with periodontal disease in number every year. Recently, two adult females with periodontal disease, one with crowding (20 y 1 m at her initial visit) and the other with bimaxillary protrusion (34 y 9 m at her initial visit), obtained good occlusion and periodontal health through orthodontic treatment. As a result of free mandibular movement by applied mild orthodontic forces and balanced occlusion, infrabony defects improved to achieve a higher level of the alveolar crest.

Adult↗
PubMed1990

[Bronchiectasis with normal paranasal sinus roentgenogram].

Bronchiectasis has come to be considered as a type of sinobronchial syndrome in Japan, but there exist some cases without chronic sinusitis. We studied the clinical features of 14 cases of bronchiectasis with definitely normal paranasal sinus roentgenogram, diagnosed during the past ten years. There were eleven middle-aged women and three men. Ten patients (71%) complained of hemoptysis, one (7%) of dry cough, one (7%) of productive cough, and the two (14%) had no complaint. In seven patients (50%) CT and bronchography showed localized cylindrical bronchiectasis in the right middle lobe and/or left upper lobe lingular division. They were considered to be middle lobe lingular syndrome. Three patients (22%) with localized varicose or cystic bronchiectasis had a history of pneumonia or pertussis in their infancy, so their bronchiectasis were considered secondary to infantile bronchopulmonary disease. Two patients (14%) had diffuse cystic bronchiectasis and were almost asymptomatic. They might be cases congenital bronchiectasis or Williams-Campbell syndrome. Pulmonary function tests were normal in most of the cases and sputum culture revealed no cases of persistent bacterial infection. These clinical features are quite different from those of bronchiectasis reported as sinobronchial syndrome, in which chronic productive cough, poor pulmonary function, persistent bacterial infection, etc. are significant. So we conclude that there are two distinct groups in bronchiectasis.

Adult↗
PubMed1990

[A case of desquamative interstitial pneumonia (DIP) suggesting a relationship to chronic eosinophilic pneumonia (CEP)].

A 43-year-old man was admitted to our hospital because of cough and dyspnea. His chest X-ray showed bilateral basal infiltrative shadows. The increased eosinophils in BAL suggested chronic eosinophilic pneumonia (CEP), whereas the TBLB specimens showed findings compatible with desquamative interstitial pneumonia (DIP). The open lung biopsy specimens showed typical findings of DIP with a peripheral zone, suggestive of CEP. These two diseases may be only phasal differences of reaction to the same extrinsic stimulation.

Adult↗
PubMed1990

[A case of acute lupus pneumonitis followed by high-resolution CT].

A 43-year-old woman was admitted to our hospital because of fever and dyspnea. She had facial rash, hair-loss, arthralgia, urinary casts, thrombocytopenia, lymphocytopenia, and deposits of IgG, IgM, C3 in the epidermis. SLE was diagnosed. She also had severe dyspnea, which gradually progressed. In spite of steroid pulse therapy and cyclophosphamide, she eventually died about two months after admission. Chest X-ray film showed bilateral ground-glass shadow and volume-loss. High-resolution CT of the lung showed marked high density area with airbronchogram in the posterior part and a gradually enlarging slight high density area in the anterior area. Pathological findings of the posterior area were atelectasis and dense fibrosis. The findings of the anterior area were collapsed alveoli and dilated alveolar ducts. These findings might suggest that alveolar collapse play a major role in the course of pulmonary fibrosis of this patient.

Adult↗
PubMed1989

Clinical and physiologic significance of local tissue renin-angiotensin systems.

Increasing and compelling evidence continues to amass that favors the existence of local tissue renin-angiotensin systems. All renin-angiotensin system components have been demonstrated in kidney, brain, arteries, adrenals, and other organs. Favoring its clinical importance are direct demonstration of its components in tissues; dissociation between hemodynamic and structural effects of renin-angiotensin system inhibition; evidence for local modulating roles with other humoral, autocrine/paracrine, and growth factors; and the effects of renin-angiotensin system inhibitors in patients who are anephric or have low plasma renin activity. Evidence will be presented demonstrating the hemodynamic/structural dissociation of pharmacologic agents that reduce cardiac mass in spontaneously hypertensive rats with left ventricular hypertrophy. Although centrally active adrenolytic agents, angiotensin-converting enzyme inhibitors, and calcium antagonists all reduce cardiac mass, their structural and cardiac functional effects differ greatly. Even within the angiotensin-converting enzyme inhibitor group their effects vary: improving, impairing, or not changing the Frank-Starling relationships. It is postulated that there is great variability of cardiac intramyocytic penetration of the pharmacologic agents and of their local intracellular effects on mitogenesis. The implications for cardiac function and therapy are vast.

Animals↗
PubMed1989

Effect of brain natriuretic peptide on cyclic GMP accumulation in a kidney epithelial cell line (LLC-PK1).

The effect of porcine brain natriuretic peptide (pBNP) on cyclic GMP accumulation was studied in the kidney epithelial cell line, LLC-PK1. The addition of pBNP to the LLC-PK1 cells produced a time- and concentration-dependent increase in cyclic GMP accumulation and this effect was equipotent to that of alpha-human atrial natriuretic peptide (alpha-hANP). The simultaneous addition of pBNP and alpha-hANP at the maximal effective concentration of 10(-6) M did not have an additive effect on the cyclic GMP contents. The findings suggest that pBNP and alpha-hANP may share the same receptor in the LLC-PK1 cells.

Animals↗
PubMed1989

Efficacy and immunogenicity of acellular pertussis vaccine by manufacturer and patient age.

Acellular pertussis vaccines, which have been used in Japan since 1981, vary in antigenic constituents among manufacturers. First, to assess the immunogenicity by manufacturer and patient age, 161 children aged 3 months to 2 years were immunized by acellular pertussis vaccine from one of three Japanese manufacturers, Biken, Takeda, or Kitasato. Anti-pertussis toxin antibody responses for children immunized with Takeda and Kitasato vaccines were comparable with patients with pertussis in the convalescent stage, and anti-pertussis toxin antibody response for Biken vaccine was far higher than those of convalescing patients. Anti-filamentous hemagglutinin antibody responses for the children given the three vaccines were far higher than those of the patients. Weak serotype 1.3 agglutinin responses were observed only in children administered the Takeda vaccine. Comparing these antibody responses among various age groups, the immunogenicity of acellular vaccines in children aged 3 to 6 months was comparable with children aged 2 years. Second, to assess the manufacturer-specific efficacy, 495 households of patients with pertussis were surveyed from 1981 to 1988. The estimated efficacy of the acellular pertussis vaccines in children aged 2 to 8 years was 82%, and there were no major differences in the secondary attack rates among children immunized with acellular pertussis vaccine from each manufacturer, ie, 12.5% (1/8) for Biken, 11.1% (2/18) for Takeda, and 5.9% (1/17) for Kitasato. We conclude from these two studies that similar efficacy was observed in children aged 2 years or older for acellular pertussis vaccines from the three manufacturers, which produced anti-pertussis toxin antibody responses comparable with patients with pertussis and far higher antifilamentous hemagglutinin antibody responses than in the convalescing patients, and that age did not affect the immunogenicity of acellular vaccines.

Age Factors↗
PubMed1989

Effect of ATP and amiloride on ANF binding and stimulation of cyclic GMP accumulation in rat glomerular membranes.

We investigated ANF binding and stimulation of cGMP accumulation in isolated rat glomerular membranes in the presence and absence of amiloride and ATP. Amiloride enhanced high affinity binding of ANF without affecting its stimulation of cGMP. In contrast ATP decreased binding and decreased basal cGMP accumulation without affecting the ability of ANF to stimulate cGMP. These data indicate that ANF binding and stimulation of cGMP accumulation can be regulated independently supporting further the concept of receptor heterogeneity in renal glomerular membranes.

Adenosine Triphosphate↗
PubMed1989

A treatment trial of delayed sleep phase syndrome with triazolam.

Triazolam causes a phase-shift of the circadian rhythm of locomotor activity in golden hamsters. We attempted to treat two patients with delayed sleep phase syndrome (DSPS) with triazolam. In one male patient we administered triazolam when the sleep phase began to delay after chronotherapy. Triazolam combined with chronotherapy enabled him to normalize and stabilize his sleep-wake cycle. But in the other female patient despite normalization of her sleep-wake cycle, she became depressive and did not continue taking the drug. In some cases triazolam is useful for the treatment of DSPS, but in others, triazolam induces a depressive state.

Adult↗