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Biomedical subjects

T Iwata

Publications and source records attributed to T Iwata.

At least 253 records · Page 14Linked to original sources
PubMed1991

[Etiological examination of idiopathic interstitial pneumonia and lung cancer in autopsy cases].

In order to investigate the etiology of usual interstitial pneumonia (UIP) and UIP with lung cancer (LC), autopsy findings in 18 cases of UIP with LC and 11 cases of uncomplicated UIP were clinicopathologically compared with the environmental factors of smoking habits and occupation. UIP with LC was highly correlated with smoking, especially heavy smoking and with occupations in which dust is inhaled, such as electrical installation and ceramic production, indicating that these environmental factors are important background factors in the complication of UIP with IC. Pathologic examination of cases of UIP with LC (6 squamous cell carcinomas, 5 small cell carcinomas, 4 adenocarcinomas, and 3 large cell carcinomas, 2 of which showed pulmonary double carcinoma revealing a slight correlation between fibrosis and primary site of LC and a slightly greater correlation of squamous cell carcinoma and small cell carcinoma to smoking habits and inhalation of dust. In terms of the correlation between UIP and LC among autopsy cases, the environmental factors proved to be more significant than the fibrotic findings. These environmental factors are thought to merit consideration as common predisposing factors in the development of LC and its complication with UIP.

Aged↗
PubMed1991

[Clinicopathological features of metastatic pulmonary calcinosis with malignant neoplasm].

Metastatic pulmonary calcinosis is a rare complication seen in malignancies accompanied by hypercalcemia, or chronic renal failure. We reviewed the clinicopathological findings of 8 cases of metastatic pulmonary calcinosis accompanied malignancy revealed at autopsy. The underlying diseases were malignant lymphoma in 3 cases (adult T cell lymphoma in 2 cases), multiple myeloma in 2, lung cancer in 2, and acute myelocytic leukemia in 1, all cases were complicated by hypercalcemia and renal failure. Chest X-ray revealed almost normal findings in 2 cases, bilateral diffuse infiltrates in 4, bilateral infiltrates in the apex in 1, and right atelectasis in 1. Bone scintigraphy was performed in 4 cases, and revealed warm pulmonary uptake in 1 patient with multiple myeloma and 1 with lung cancer, but normal findings in the 2 other cases. Histopathological examination revealed diffuse alveolar septal edema and fibrosis due to calcium deposition, which were considered to be the cause of respiratory failure. Metastatic pulmonary calcinosis is a rare but a serious complication in malignancies accompanied by hypercalcemia and renal failure, and bone scintigraphy seems to be a useful method for its diagnosis.

Adolescent↗
PubMed1991

Treatment of persistent sleep-wake schedule disorders in adolescents with methylcobalamin (vitamin B12).

Two adolescent patients suffering from persistent sleep-wake schedule disorders appear to have responded to treatment with vitamin B12 (methylcobalamin). A 15-year-old girl with delayed sleep phase syndrome (DSPS) and a 17-year-old boy with hypernychthemeral syndrome complained of not being able to attend school despite many trials of medication. The improvement of the sleep-wake rhythm disorders appeared immediately after the administration of high doses (3,000 micrograms/day) of methylcobalamin. Neither patient showed any laboratory or clinical evidence of vitamin B12 deficiency or hypothyroidism (which can cause B12 deficiency). Serum concentrations of vitamin B12 during treatment were in the high range of normal or above normal. The duration of the sleep period of the DSPS patient decreased gradually from 10 hours to 7 hours, and the time of sleep onset advanced from 2 a.m. to midnight. The period of the sleep-wake cycle of the hypernychthemeral patient was 24.6 hours before treatment and 24.0 hours after treatment. The relationship between the circadian basis of these disorders and vitamin B12 and its metabolites is discussed.

Achievement↗
PubMed1991

Blood pressure and heart rate variability in elderly patients with isolated systolic hypertension.

To investigate the circadian profiles of BP and heart rate in elderly patients with isolated systolic hypertension (ISH), the variability of BP and heart rate during day time (daytime) and the amplitudes of nocturnal fall were evaluated in ISH (n = 19) comparing with those of essential hypertensive patients (EHT, n = 18) and normotensive subjects (NT, n = 16) in the same age range. ISH showed a significantly wider BP variability during the day time and a greater amplitude of nocturnal fall compared with EHT and NT. However, the heart rate variability during the daytime and the amplitude of nocturnal fall were similar among the three groups. ISH showed a stronger correlation between BP and heart rate during 24 hours compared with EHT and NT. Approximately 80% of ISH showed a significant positive correlation between BP and heart rate. These results suggest that the BP of ISH patients is susceptible to fluctuations in autonomic nerve activity.

Aged↗
PubMed1991

Effect of renal denervation on the development of hypertension in Dahl-Iwai salt-sensitive rats.

Renal denervation has been shown to delay the onset of hypertension in spontaneously hypertensive rats and DOCA-salt sensitive rats. We investigated the contribution of the renal nerves to the development of hypertension in Dahl-Iwai salt-sensitive (DS) rats. Bilateral renal denervation or sham-operation was carried out in DS rats, and animals were then kept on a high salt diet (study I) or on a normal salt diet (study II). DS rats became severely hypertensive (207 +/- 8 mmHg) after 4 weeks on a high salt diet. They became mildly hypertensive (156 +/- 3 mmHg) after 4 weeks on a normal salt diet. In both studies, renal denervation exerted no effect on the development of hypertension in the DS rats. The urinary sodium excretion, urinary volume, heart rate and body weight were unaltered by renal denervation. These results indicate that the renal nerves do not make a major contribution to the development of hypertension in DS rats.

Animals↗
PubMed1991

Simple and efficient method for clinical isolation of Bordetella pertussis.

Commercially available Amies transport medium with charcoal and three isolation media were tested to assess their efficiency in the clinical isolation of B. pertussis. First, the isolation rates of B. pertussis were compared between direct inoculation of nasopharyngeal specimens and inoculation after being stored in Amies transport medium for eight hours or less. The organism was detected in 43 specimens from 29 patients with at least one of the two inoculation methods. The comparative isolation rates were 81% (35 of 43) for both direct inoculation and transport medium. Second, nasopharyngeal specimens were incubated for five days at 35 degrees C on the three media; Bordet Gengou Medium (BG) with 5 micrograms of CEX per ml, Cyclodextrin Solid Medium (CSM) with 5 micrograms of CEX per ml, and Charcoal Agar with 40 micrograms of CEX per ml. The organism was detected from 44 nasopharyngeal specimens of 20 patients on at least one of the three tested media. The comparative isolation rates were 91% (40 of 44) on BG with 5 micrograms of CEX per ml, 93% (41 of 44) on CSM with 5 micrograms of CEX per ml, and 91% (40 of 44) on CA with 40 micrograms of CEX per ml. Although no differences in the isolation rates were observed among the three media, the appearance of the colonies was earlier by one day on BG than the other two media. The detection of B. pertussis was occasionally easier on CA than on the other two because of its higher suppression of nasopharyngeal flora.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological Techniques↗
PubMed1991

Mixed outbreak of Bordetella pertussis and Bordetella parapertussis in an apartment house.

From September through November of 1985, a mixed outbreak of Bordetella pertussis and Bordetella parapertussis occurred in an apartment house in Ashikaga City, Japan. Bacteriological and serological investigations were conducted on seven families, comprising 13 adults and 19 children, living in the same apartment house and having social contacts. For all the subjects, cultivation of nasopharyngeal mucus and measurement of pertussis agglutinin antibody, anti-PT antibody, and anti-F-HA antibody were performed. On the basis of the clinical, bacteriological or serological findings, seven children of three families (families A, B and C), including the first child patient (index case) of family A, were diagnosed as having infections caused by B. pertussis, or B. parapertussis or both. B. pertussis and/or B. parapertussis were isolated from six of the seven child patients. B. pertussis alone was isolated from three children (one in each family), and two of them had not been vaccinated. B. parapertussis alone was isolated from two children, while both bacteria were isolated from one child. Those three children from whom B. parapertussis was isolated were in family C, which was the last of the three families to develop symptoms of infection. Josamycin had been administered to two of the three children from whom B. parapertussis was isolated before the nasopharyngeal mucus specimen was collected. In one of the two children from whom only B. parapertussis was isolated, the significant elevation of anti-PT antibody titer was observed, which was indicative of a mixed infection with B. pertussis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Clinicopathological study of methicillin-resistant Staphylococcus aureus detected by pulmonary microbial culture in autopsied cases].

Microbial culture of lung specimens from 569 autopsied cases from 1986 to 1989 revealed methicillin-resistant Staphylococcus aureus (MRSA) in 28 cases, which were subsequently analyzed clinicopathologically. The number of MRSA positive cases has markedly increased in recent years (2 cases in 1986, 2 in 1987, 6 in 1988, 18 in 1989). The most frequent underlying disease was neoplasm, which was seen in 17 cases. Of non-neoplastic diseases, liver cirrhosis and diffuse panbronchiolitis were prevalent. Twenty-four cases had received a course of antibiotic therapy. Antibiotics frequently administered were third-generation Cephem and Imipenem/cilastatin sodium (used in 20 cases). Antibiotics o which MRSA was sensitive were administered in only one case (minocycline). Sputum culture was performed in only 10 cases, 5 of which were MRSA positive. MRSA had acquired resistance to fosfomycin and ofloxacin. Histological examination revealed complication by pneumonia in 19 cases. In 7 of these 19 cases, MRSA was the only pathogen detected. Pulmonary MRSA infection detected at autopsy is frequently seen in patients with terminal stage cancer, but it is frequently not diagnosed and is undertreated. This may be a factor responsible for the recent marked increase in the proportion of MRSA in pathogens causing infection within medical institutions.

Cross Infection↗
PubMed1991

Mechanical stress as a stimulant to the production of osteocalcin in osteoblast-like cells.

When mechanical stress is applied, osteoblasts have shown to produce bone turnover stimulating hormones and enzymes like prostaglandin E2 (PGE2), cyclic AMP, alkaline phosphatase, and collagenase. Osteocalcin (bone Gla protein) is also a protein produced by osteoblasts to control bone metabolism. Thus, its production may also be stimulated by mechanical stress. The purpose of this investigation was to test if mechanical stress stimulates osteoblast-like cells to produce osteocalcin in vitro. The results suggest that osteocalcin production is stimulated at the initial stage of the culture by cyclic tension and relaxation force, and secretion may decrease with time.

Animals↗
PubMed1991

The lactic acid and citric acid content in the gingival fluid of orthodontic patients.

Alveolar bone turnover has two phases: bone resorption and formation. Bone resorption entails both mineral removal and collagenolysis. A pH decrease over the local bone surface is required for mineral removal. Both lactic acid and citric acid has been suggested as the acids which remove crystals. During the orthodontic movement of teeth, a process of overall bone resorption occurs during displacement, whereas at the retention stage this process needs to be stopped in order to stabilize the alveolar bone. Thus, lactic acid and citric acid may be valid parameters of bone resorption intensity. The purpose of this investigation is firstly to test if these acids can be detected in gingival fluid around the moving teeth, and secondly to find if any changes occur before, during and after orthodontic tooth movement. The results indicate that these acids can be good parameters which show how favorably tooth movement is proceeding. They also show how stable the teeth are when orthodontic force is stopped to apply.

Adolescent↗
PubMed1991

Outbreak of pertussis in a residential facility for handicapped people.

An outbreak of pertussis was recognized and investigated in a ward for neurologically impaired residents. Of 50 residents ranging in age from 8 to 25 years old, 41 (82%) had serological or bacteriological evidence of pertussis infection and 28 (56%) developed typical symptoms of pertussis. Of the 50 residents, nine were immunized and 41 were unimmunized. There were no significant differences in the rate of infection and rate of developing typical symptoms between the immunized and unimmunized (9/8/4 vs 41/33/24). Of 43 carers, 6 (14%) developed typical symptoms and four of the six showed serological evidence of pertussis infection. Epidemiological survey of this outbreak revealed that pertussis was introduced and spread by the carers. Erythromycin which was administered only to the residents did not prevent the spread of pertussis. We conclude that pertussis immunization including a booster dose should be considered for neurologically impaired people in a closed environment and erythromycin prophylaxis should include adult carers.

Adolescent↗
PubMed1991

[Old pulmonary embolism causing intrabronchial bleeding].

A 51-year-old man was admitted because of hemoptysis. Physical examinations and chest XP revealed no abnormal findings. Fiberoptic bronchoscopy showed pulsatile bleeding at the orifice of right B6. Right bronchial arteriography showed a markedly dilated and tortous bronchial artery and shunting to the pulmonary arterial system in the middle and lower lobes. Pulmonary arteriography showed complete obstruction of the right middle lobar and lower lobe segmental arteries (A6, 9, 10). The hemoptysis was thought to be due to increased blood flow of the right bronchial artery, which compensated for reduced right pulmonary arterial flow. Right middle and lower lobe resection was done to prevent further hemoptysis. The resected specimen revealed old thromboemboli in the right middle and lower lobe pulmonary arteries. In this case old pulmonary embolism should be considered as a cause of intrabronchial bleeding.

Bronchial Arteries↗
PubMed1991

[Cellular interstitial pneumonia and follicular bronchiolitis diagnosed by open lung biopsy in a patient with rheumatoid arthritis].

A 54-year-old woman under treatment for rheumatoid arthritis was admitted because of aggravation of dyspnea on effort and restrictive pulmonary dysfunction. Although chest X-ray revealed no marked change, the symptoms progressively worsened, necessitating open lung biopsy for diagnosis and treatment. Based on the histopathological findings of the biopsied tissue, the patient was diagnosed as having active rheumatoid lung complicated with cellular interstitial pneumonia and follicular bronchiolitis. The patient responded well to adrenocorticosteroid and immunosuppressor therapy, and is now being followed up as an outpatient. Rheumatoid arthritis can be complicated by diverse lung diseases. Among them one important disease is interstitial pneumonia, which serves as a prognostic factor. When cellular interstitial pneumonia is treated with adrenocorticosteroid therapy, it responds well and its prognosis is good. Therefore, its early detection and appropriate adrenocortical therapy are essential. Patients with rheumatoid arthritis presenting with dyspnea on effort and pulmonary dysfunction should be examined for cellular interstitial pneumonia, follicular bronchiolitis and other lung diseases, even when no marked change is visible on chest X-ray films.

Arthritis, Rheumatoid↗
PubMed1990

Correlation between pharmacokinetics and pharmacologic effects of a new imidazole thromboxane synthetase inhibitor.

A new imidazole derivative, sodium 4-[alpha-hydroxy-5-(1-imidazolyl)-2-methylbenzyl]-3,5-dimethylbenzoat e dihydrate (1; Y-20811), is a potent selective inhibitor of thromboxane (TX) synthetase and a candidate drug for preventing ischemic circulatory disorders. After oral dosing in beagle dogs, 1 persistently inhibited TX production, although the elimination of the drug was relatively rapid from plasma. The amount of drug distributed in platelets was small. However, 1 was eliminated from platelets very slowly (t1/2 = 41-130 h), the rate of elimination being comparable to the turnover rate of platelets. From the in vitro experiments, an obvious positive correlation was noted between the amount of the drug bound with TX synthetase in platelets and the inhibition of TX production. This correlation suggested that the small amount of 1 detected in platelets in vivo was large enough to inhibit TX production. From these observations, 1 is thought to dissociate extremely slowly from the active sites of TX synthetase. Consequently, the duration of the effect was dependent on the turnover of platelets.

Animals↗
PubMed1990

Dissecting and fusiform aneurysms of vertebro-basilar systems. MR imaging.

The magnetic resonance (MR) findings of three cases with vertebro-basilar dissecting aneurysms (DA) were compared with those of two cases with vertebro-basilar fusiform aneurysms (FA). No abnormal findings, excepting a dilatation of a signal-void area corresponding to the arterial blood flow, were shown on the MR images in the patients with a FA. In contrast to the FA cases, various abnormalities were detected by the MR studies in all three DA cases. An intimal flap and a double lumen were demonstrated in one case. An intra-mural hematoma was shown in one case. A hematoma neighboring the parent artery was demonstrated in two cases. MR imaging was thought to be useful for detecting intracranial vascular lesions, such as a DA, and for discriminating between a DA and a FA.

Adult↗
PubMed1990

A case of rectal carcinoid with extensive sacral breakage.

A 48 year old woman with a massive retrorectal tumor extensively invading the sacrum is presented herein. A submucosal tumor, apparently of rectal origin, was found on the posterior rectal wall infiltrating posteriorly into the sacrum. Abdominosacral resection of the rectum with partial sacrectomy was thus performed and postoperative examination revealed the tumor to be carcinoid which has hitherto been associated with moderately benign behavior. Although remote metastasis was absent, extensive lymph node metastasis was observed, however, 2 years have passed since the operation without any evidence of recurrence.

Bone Neoplasms↗
PubMed1990

A new experimental trial using repeated heating every 24 hours for local hyperthermic therapy with bleomycin in vivo.

This report presents the effect of repeated heating every 24 hrs using bleomycin (BLM) which, although seemingly contrary to the usual agreement that hyperthermia should be carried out with a long interval due to thermotolerance, holds many possibilities. FM3A cells on the foot pad of C3H mouse were immersed in a heated water bath at 43 and 44 degrees C for 30 min. The effect of repeated heating was appreciated by an improved growth curve and 50 day survival compared to mice which received heating twice with a 96-hr interval. Repeated heating every 24 hrs 5 times with BLM suppressed tumor growth significantly as compared to heating twice with a 96-hr interval without BLM. The longest survival time was obtained by the repeated heating with BLM among all protocols. There is therefore a good possibility that more effective results could be obtained clinically by repeated heating over a short period.

Animals↗