Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 739 records · Page 41Linked to original sources

PubMed1989

Abnormal elastic fibers in elastosis of breast carcinoma. Ultrastructural and immunohistochemical studies.

Elastosis in benign and malignant breast lesions was studied by light microscopic immunohistochemistry for elastin and by electron microscopy. Upon immunohistochemical examination for elastin, elastosis, particularly in scirrhous-type ductal carcinoma, showed two characteristic staining patterns: fibrously and intensely stained elastic fibers and evenly stained elastic masses. Elastic fibers showing increased fibrous staining occurred mainly in the stromal areas, and were considered to be newly formed because they consisted of tannic acid-positive amorphous components and abundant microfibrils. Evenly stained elastic masses were observed mainly in the periductal areas and showed less intense stainability. These masses consisted of numerous fine amorphous components with plentiful microfibrils. In some regions within these masses, there were condensed accumulations of irregularly arranged small amorphous components associated with only a few microfibrils. These amorphous components had an ill-defined outline and were occasionally associated with spiralling collagen fibrils and cell debris. On the basis of these findings, the periductal evenly stained elastic masses were thought to be formed by excessive production of elastic fibers and degradation of pre-existing and newly formed elastic fibers.

Breast Neoplasms↗

PubMed1989

Multicentric astrocytomas of the optic chiasm, brain stem and spinal cord.

Autopsy was performed on a 52-year-old man with a 20-year history of neurological symptoms. At autopsy, both a brain stem tumor and a spinal cord tumor were found. These showed the features of pilocytic astrocytoma histologically. A pilocytic astrocytoma was also found in the optic chiasm upon microscopical examination. These three tumors were thought to be multicentric astrocytomas, because there was no continuity among them and no evidence of dissemination or metastasis by any pathway. From a review of the literature, the present case is considered to be an exceedingly rare one because of the multicentric sites of occurrence.

Adult↗

PubMed1989

Studies on the relationships of IgA to human liver. IgA deposition in non-alcoholic liver diseases.

An investigation was conducted to clarify the relationships of IgA to the human liver. Immunocytochemical studies were performed on biopsy specimens from patients with cirrhosis and chronic hepatitis without any apparent history of alcohol abuse. The results showed that 1) a large amount of IgA is associated with the sinusoidal surface of hepatocytes, endothelial cells and Kupffer cells, 2) this IgA contains J chain and can form a complex with secretory component, and 3) this mainly belongs to the IgA1 subclass, 4) IgA in vesicles within hepatocytes and Kupffer cells is always associated with acid phosphatase activity, and 5) IgA containing vesicles within ductular epithelial cells always lack such enzyme activity. We conclude that 1) the IgA bound to the surface of hepatocytes, sinus endothelial cells and Kupffer cells is polymeric IgA1 uncomplexed with SC, and 2) this IgA occasionally enters these cells, and may be degraded in the lysosomes. 3) Polymeric IgA combines with SC in the ductular epithelium and may be secreted into bile. These findings suggest that J chain-linked polymeric IgA bound to the surface of hepatocytes and Kupffer cells has a certain pathological significance in liver diseases and might be involved in the clearance of excess IgA from the circulation.

Cell Membrane↗

PubMed1989

Relationship between plasma atrial natriuretic peptide concentrations and cardio-thoracic ratio during the early neonatal period.

Twenty-seven neonates were examined at 2.6 +/- 1.5 hours of age (stage 1) and 21 +/- 4.9 hours of age (stage 2) to clarify the relationship between cardio-thoracic ratio (CTR) on chest roentgenograms and plasma atrial natriuretic peptide (ANP) concentration. Among 22 infants who showed elevated plasma ANP, 14 had gained body weight (group A), while 8 other infants had lost weight (group B) at stage 2. The remaining 5 infants had decreased plasma ANP concentrations combined with weight loss at stage 2 (group C). All infants of group B had a patent ductus arteriosus. The plasma ANP concentration and CTR of groups A and B increased during the study period, while those of group C decreased. A linear relation was found between plasma ANP concentration and CTR in all cases (p less than 0.02). This study indicates that increased plasma levels of ANP are associated with an increased CTR.

Atrial Natriuretic Factor↗

PubMed1989

Role of atrial natriuretic peptide in the diuresis of a newborn infant with the syndrome of inappropriate antidiuretic hormone secretion.

A fullterm infant had fetal distress and stained amnion. He underwent an exchange blood transfusion at 12 hours after birth because of hyperbilirubinemia. He developed oliguria combined with high urine osmolality during the first 27 hours of life despite normal creatinine clearance. The diagnosis of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) was made on the basis of high urine osmolality, low plasma osmolality and elevated plasma arginine vasopressin (AVP) concentration. We determined the plasma atrial natriuretic peptide (ANP) concentration for the first 4 days of life. After 27 hours after birth, urine volume increased while plasma AVP concentration remained high. On the other hand, plasma ANP concentration gradually increased after 27 hours of life. We speculate that ANP may play an important role in producing the spontaneous diuresis in the newborn infant with SIADH.

Atrial Natriuretic Factor↗

PubMed1989

Effect of a synthetic progestin on ventilatory response to hypoxia in anesthetized rats.

Effects on ventilatory responses to progressive isocapnic hypoxia of a synthetic potent progestin, chlormadinone acetate (CMA), were determined in the halothane-anesthetized male rat. Ventilation during the breathing of hyperoxic gas was largely unaffected by treatment with CMA when carotid chemoreceptor afferents were kept intact. The sensitivity to hypoxia evaluated by hyperbolic regression analysis of the response curve did not differ between the control and CMA groups. The reduction of ventilation after bilateral section of the carotid sinus nerve (CSN) in hyperoxia was less severe in CMA-treated than in untreated animals. Furthermore, the CMA-treated rats showed a larger increase in ventilation during the hypoxia test and a lower PO2 break point for ventilatory depression. Inhibition of hypoxic ventilatory depression by CMA persisted even after the denervation of CSN. We conclude that exogenous progestin likely protects regulatory mechanism(s) for respiration against hypoxic depression through a stimulating action independent of carotid chemoreceptor afferents and without a change in the sensitivity of the ventilatory response to hypoxia.

Afferent Pathways↗

PubMed1989

Maturational changes and origin of urinary human epidermal growth factor in the neonatal period.

In order to clarify the characteristics of urinary human epidermal growth factor (hEGF) excretion in the newborn period, we examined hEGF in the 41 newborn infants; 12 healthy preterm infants (group A), 10 healthy full-term infants (group B), 12 full-term infants with neonatal asphyxia (group C), 7 full-term infants treated with tobramycin (group D) during the first week of life. Renal function tests, i.e. creatinine clearance (Ccr), and N-acetyl-beta-D-glucosaminidase (NAG) as a parameter of renal tubular damage, were examined in 29 full-term infants. Urinary hEGF excretion showed a linear increase with gestational age. During the first week of life, urinary hEGF excretion in group B increased with age. However, urinary hEGF excretion in group A remained at the constant level through the study period. Ccr in group C was significantly decreased through the study period when compared with that in group B. NAG indices in group C during the first week of life and those in group D on days 5-7 of life were more elevated than those in group B. Urinary hEGF excretion in group C on days 4-7 of life and that in group D on day 7 of life were significantly decreased when compared with that in group B. These results suggest that urinary hEGF excretion is related to the maturation and that the source of urinary hEGF may be renal tubular cells.

Age Factors↗

PubMed1989

Effects of aldosterone and atrial natriuretic peptide on water and electrolyte homeostasis of sick neonates.

To clarify fluid homeostasis in neonates, 27 sick neonates (6 had respiratory distress syndrome, 12 had hyperbilirubinemia, and nine were low birth wt infants) were studied on 13 to 15 days of age. The infants were stabilized and required neither ventilation nor intravenous fluids at the time of study. All infants were breast fed, and their sodium intake ranged from 1.7 to 2.9 (2.2 +/- 0.3) mEq/kg/d. Gestational age ranged from 30 to 39 (34 +/- 3.4) wk and birth wt ranged from 1080 to 3280 (2,070 +/- 672) g. Creatinine clearance (Ccr), fractional excretion of sodium (FENa), fluid and electrolyte balance, plasma aldosterone and human atrial natriuretic peptide (ANP) concentrations were determined and analyzed according to conceptional age (CA) to clarify their maturational changes. None of the infants had a negative sodium balance or hyponatremia. Ccr remained almost constant until the 36th wk of CA, after which an abrupt increase occurred. FENa and plasma aldosterone level of infants less than the 32nd wk of CA were high (0.75 +/- 0.33%, 2868 +/- 1153 pg/ml, respectively) when compared with those in infants of the 33 to 34th wk of CA (0.47 +/- 0.12%, 1,663 +/- 488 pg/ml, respectively). There was a negative correlation between FENa and plasma aldosterone level in all cases (p less than 0.01). Plasma ANP level of all infants were higher than those of healthy adults (40 +/- 20 pg/ml). A good correlation was observed between Ccr and plasma ANP level in infants less than 36th wk of CA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

PubMed1989

Liver function in congestive heart failure: abnormal elevation of serum hepatic enzyme and hepatic venous flow velocity.

Fifty one patients (pts) with various heart diseases and 6 normal subjects (N) were studied. Four of the 51 pts showed unusually high GOT values (greater than 3000 IU) without preceding evidence of acute heart failure, myocardial infarction, or hepatitis. Of these 4 pts, either ventricular tachyarrhythmias, marked bradycardia, or rapid ventricular response with atrial fibrillation (af) were evident a few days prior to the GOT elevation. GOT values returned to below 100 IU within a few days, but hypotension and frequent arrhythmias were sustained in 3 of the 4 pts and these 3 pts died about one month later. The symptoms of the remaining one improved but he too died 9 months later of ventricular fibrillation. A postmortem histological examination revealed centrilobular necrosis of the liver cells. Thus, abnormal GOT elevation may result from hepatic cell necrosis, which is probably due to tissue hypoperfusion caused by severe arrhythmias. Hepatic venous flow velocity (HFV) was measured in the remaining 47 pts and 6N using a pulsed doppler echocardiogram. The HFV curve was biphasic, with the first curve corresponding to the forward flow velocity during ventricular systole (s-HFV) and the second corresponding to ventricular diastole (d-HFV). The ratio of the area under s-HFV curve to the sum of areas under s-HFV and d-HFV curves was defined as the VI ratio. In N, the VI ratio was 0.7 +/- 0.06 whereas the VI ratio in pts in sinus rhythm tended to be above 0.7. This indicated that s-HFV is greater than d-HFV in N while s-HFV is less than d-HFV in pts in sinus rhythm. There was a good negative correlation (n = 15: r = -0.70) between VI ratio and cardiac index (CI) in these pts, suggesting that the contribution of s-HFV to the venous return becomes greater as the cardiac function becomes more impaired. In pts with af, the VI ratio was below 0.5 and there was a good positive correlation (n = 14: r = 0.82) between the VI ratio and CI. This suggested that the s-HFV may be reduced due to a lack of atrial contribution in af so that contribution of d-HFV to venous return becomes greater as the cardiac function becomes more impaired. Thus, the HFV pattern may reflect the abnormality of the cardiac pump function in human beings.

Adult↗

PubMed1989

Spontaneous tumors in F-344/Jcl rats.

The age-related incidence of spontaneously occurring neoplastic and non-neoplastic lesions in untreated F-344/Jcl rats, used as controls in carcinogenicity testing, were studied from the histological examination of tissues from 469 males and 354 females. The incidence of spontaneous tumors was 83.2% in the males and 71.2% in the females. The most common neoplasms were leukemia (males: 24.3%, females: 24.0%), pituitary adenoma (males: 16.0%, females: 45.2%), pheochromocytoma (males: 14.7%, females: 7.3%), testicular interstitial cell tumor (males: 79.1%), and uterine endometrial stromal polyp(females: 16.4%). The incidence of other tumors of almost all the organs and/or tissues was low. Non-neoplastic lesions generally increased with advancing age of the animals.

Age Factors↗

PubMed1989

Differential sensitivity to hypoxic inhibition of respiratory processes in the anesthetized rat.

To estimate the sensitivity to hypoxic inhibition of various regulatory processes for respiration, changes in breathing pattern during hypoxic ventilatory depression (HVD) were analyzed in the halothane-anesthetized spontaneously breathing rat using a "progressive isocapnic hypoxia test." In the carotid sinus nerve (CSN) intact rats, ventilatory augmentation was followed by depression due to reduction in respiratory frequency (f) at end-tidal PO2 (PETO2) levels below 50-60 mmHg despite increased afferent activities from the carotid chemoreceptors. After CSN section, ventilation was progressively depressed at PETO2 lower than normoxic level with simultaneous decreases of f and tidal volume. An increase in CO2 stimulus or the prevention of arterial hypotension during hypoxia by infusing a vasoconstrictor agent (phenylephrine) inhibited the occurrence of ventilatory depression in both the CSN intact and denervated animals. In all cases studied, the reduction in f resulted mainly from the prolongation of expiratory time (TE). The results suggest that in the anesthetized rat the effect of respiratory stimulation from carotid chemoreceptor afferents becomes inadequate to offset the prolongation of TE due to the central hypoxia at lower PETO2, and that the neural process for regulating TE is the major site of deterioration during central hypoxic inhibition. Roles of CO2 stimulus and systemic circulatory conditions in the generation of HVD were also discussed.

Afferent Pathways↗

PubMed1989