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Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 829 records · Page 46Linked to original sources
PubMed1987

Retinal inputs to the geniculate relay cells in the eastern chipmunk (Tamias sibiricus asiaticus): a comparison between color and non-color sensitive cells.

Single unit recordings were made from the relay cells of the lateral geniculate nucleus in the eastern chipmunk. Of 362 relay cells, 47 cells (13%) were classified as color sensitive and the rest as non-color sensitive cells. Non-color sensitive cells were further classified into 5 subclasses: off-phasic, on-phasic, on-off-phasic, on-tonic and uncommon types. Within the color sensitive cells there were 3 subclasses; blue excited and green inhibited (+B-G), blue inhibited and green excited (-B+G), and blue excited (+B) cells. Retinal afferents to color sensitive relay cells had the following characteristics: ganglion cells of their origin were distributed in the central high density areas of the retina and axonal conduction velocities were in the intermediate range, though they were somewhat slow in +B cells.

Animals↗
PubMed1987

Ultrastructural, histochemical, and freeze-fracture evaluation of multilamellated structures in human pulmonary alveolar proteinosis.

Ultrastructural, histochemical, and freeze-fracture studies of material recovered by bronchoalveolar lavage from patients with pulmonary alveolar proteinosis revealed four types (A, B, C, and D) of multilamellated structures (MS). Type A, the major component, consisted of concentric, trilaminar structures which were composed of two electron-dense layers and a central lucent layer (5.7-7.5 nm in overall width) alternating with wider (25-30 nm) electron-lucent intervening layers. Type B MS were formed by concentric lamellae with a 5-5.3-nm periodicity. Type C MS were composed of wavy, electron-dense lamellae with a 4-4.5-nm periodicity. Type D MS were conglomerated masses of intricately arranged double or triple electron-dense layers (7.5-13.5 nm wide) alternating with wider (30-40-nm) electron-lucent layers. The electron-dense lamellae of type A, type C, and type D MS were stained with ruthenium red, the Thiéry method, and concanavalin A, indicating the presence of carbohydrate components. Freeze-fracture studies revealed smooth inner and outer surfaces in type A MS, with the fracture planes passing through the central parts of the trilaminar structures; the intervening layers contained 10-nm particles, which probably are proteins. Type B MS had smooth surfaces, and type C MS had slightly particulate surfaces; while type D MS showed tubular or polygonal structures, 350 nm wide, with rows of particles 7-8 nm in diameter. It is concluded that type A and type D MS contain proteins and carbohydrates, probably in the form of glycoproteins, as well as phospholipids, and are related to tubular myelin. Type B and type C MS are considered to contain mainly phospholipids; type C MS are also considered to contain carbohydrates and to be related to lamellar bodies of type II alveolar epithelial cells.

Adult↗
PubMed1987

Estrogen receptors in hepatocellular carcinoma: is endocrine therapy for hepatocellular carcinoma likely to be effective?

Specimens of human liver obtained at the time of operation were assayed for cytosolic estrogen receptors by the binding assay and enzyme immunoassay (EIA). Mean estrogen receptor contents determined by the binding assay were 17.8 fmol/mg protein in non-cirrhotic liver, 7.1 in cirrhotic liver, and 0.7 in hepatocellular carcinoma, by EIA the contents were 12.1, 5.9, and 0.8 fmol/mg protein, respectively. There were significant differences among the three groups. In particular, hepatocellular carcinoma specimens contained very little or no detectable amounts of estrogen receptors in either assay. The correlation between the estrogen receptor content determined by the binding assay and that determined by EIA was significant (r = 0.822, p less than 0.001). It is suggested that the estrogen receptor content decreases with the development of liver cirrhosis and hepatocellular carcinoma and that antiestrogen endocrine therapy for hepatocellular carcinoma may be ineffective.

Adult↗
PubMed1987

Anomalous optic nerve fiber convergences in the ipsilateral retinocollicular projection: a comparison of congenitally monocular and neonatally one-eye-removed rats.

Single cell responses to electrical stimuli applied to the optic chiasm and to the lateral geniculate nucleus were studied in expanded projection to the ipsilateral superior colliculus of neonatally enucleated and congenitally monocular rats. In both types of rats latencies to the afferent volleys were longer, and the latency correlation between the optic chiasm and the lateral geniculate responses was lower in the ipsilateral than in the contralateral superior colliculus cells. This was interpreted to suggest abnormal convergence of retinal axons with different conduction velocities in the ipsilateral retinocollicular projection. The deviation of ipsilateral superior colliculus cells from the high-latency correlation of the contralateral cells was more marked in congenitally monocular than in neonatally enucleated rats.

Action Potentials↗
PubMed1987

An electron microscopic analysis of the optic nerve of the eastern chipmunk (Tamias sibiricus asiaticus): total fiber count and retinotopic organisation.

On the basis of light and electron microscopic observations of the cross-section, the total count of optic nerve fibers in the eastern chipmunk (Tamias sibiricus asiaticus) was estimated to be 5.65 x 10(5). Almost all the fibers were myelinated and only 0.9% were unmyelinated. Axon diameters of myelinated fibers showed a skewed unimodal distribution ranging from 0.2 to 3.6 microns (mean, 0.83) with the peak at 0.6-0.7 microns. Myelin sheath thickness positively correlated with the axon diameter. In the cross-section fiber density was highest in the naso-dorsal to the central part and lowest in the temporo-ventral part. Large axons are concentrated in the temporo-ventral part of the optic nerve, corresponding to the localisation of large ganglion cells in temporal crescent of the retina. A gross retinotopic organisation was verified among the optic nerve fibers in the cross-section after localised lesions by laser beam in the nasal and temporal periphery. However, when the retinal lesion was made in or around the central high density area, a non-retinotopic arrangement of the optic nerve fibers was suggested.

Animals↗
PubMed1987

Carotid chemoreceptor discharge responses to hypoxia and hypercapnia in normotensive and spontaneously hypertensive rats.

The carotid chemoreceptor discharge responses to hypoxia and hypercapnia were quantitatively compared between normotensive (NTR) and spontaneously hypertensive rats (SHR). For this purpose we recorded afferent mass discharges from the carotid sinus nerve (CSN) at various levels of end-tidal O2 and CO2 concentrations (FetO2, FetCO2 (%)) in the urethane-anesthetized, vagotomized and artificially ventilated rats. The CSN chemoreceptor discharge was evaluated by subtracting the small activity remaining in acute hyperoxia (chemoreceptor inactivation), which was estimated as baroreceptor in origin, from the large total CSN activity. The CSN chemoreceptor discharges at various levels of FetO2 or FetCO2 were expressed as the percent of control activity measured in normoxic and normocapnic conditions (FetO2, 15-16%; FetCO2, 4.5-5.1%). There was an exponential increase in the CSN chemoreceptor discharge as FetO2 was decreased from hyperoxic to various hypoxic levels (maximally 6%) at a maintained FetCO2 (normocapnia). The relationship between the CSN chemoreceptor discharge and the hypoxic stimulus was quantitatively assessed by the regression analysis using an exponential function. Exponential increases in the CSN chemoreceptor discharge by hypoxia and the parameters in the exponential function reflecting the sensitivity to hypoxia were significantly higher in the SHR than in the NTR, which indicated a high carotid chemoreceptor discharge response to hypoxia in the SHR. The CSN chemoreceptor discharge was increased linearly by increasing the FetCO2 from the normocapnic level up to about 10% at a maintained FetO2 (normoxia). Increases in discharge produced by severe hypercapnia were, however, much smaller than that caused by hypoxia. The slope of the CO2 stimulus-CSN chemoreceptor discharge response line was almost the same in NTR and SHR. The results demonstrated that the responsiveness of rat carotid chemoreceptor to hypoxia is augmented in the SHR. The role of carotid chemoreceptor afferents in ventilatory reflex responses to hypoxia and their alterations in the SHR are discussed.

Animals↗
PubMed1987

Histogenesis of unique elastinophilic fibers of elastofibroma: ultrastructural and immunohistochemical studies.

Electron microscopy and both light and electron microscopic immunohistochemical tests for elastin were employed to study the morphogenesis of the unique elastinophilic fibers of an elastofibroma removed from the subscapular region of a 62-year-old woman. Ultrastructurally, as shown by tannic acid stain, elastinophilic fibers of the elastofibroma consisted of central cores and outer zones. The latter were composed of various sizes of vaguely demarcated, irregularly shaped amorphous components and compactly and randomly arranged large amounts of microfibrils. The electron microscopic immunohistochemical results showed that the small-sized amorphous components and microfibrils in the outer zones of the elastinophilic fibers were stained evenly and of granular texture, but the vaguely outlined large amorphous components were not stained. These findings were interpreted as indicating that the amorphous components of the outer zones of elastinophilic fibers were less compact and allowed the penetration of antielastin antibody. The unique elastinophilic fibers of elastofibromas appear not to be formed by the degeneration of the fibers but by abnormal elastogenesis, including an abnormal arrangement of microfibrils.

Bone Neoplasms↗
PubMed1987

Lysozyme activity of cystic mucosal and submucosal glands in the stomal area of the gastric remnant.

In order to study the lysozyme activity in the cystic mucosal and submucosal glands in the stomal area of the gastric remnant, which is one of the components of gastritis cystica polyposa, we carried out a pathological and immunohistochemical examination of 55 patients with gastric remnants, including 19 with stomal carcinoma, after partial gastrectomy for benign gastro-duodenal diseases. These stomach specimens were examined immunohistochemically for lysozyme. The cytoplasm of some epithelial cells of cystic mucosal and submucosal glands, which showed characteristic changes in the gastro-intestinal stoma as well as background changes in the stomal carcinoma, showed a strongly positive reaction for lysozyme. These strongly lysozyme-positive cells in the cystic mucosal glands appeared more frequently in the cases of stomal carcinoma than in the non-cancerous controls.

Aged↗
PubMed1987

Malignant lymphoma of the oral cavity: clinicopathologic analysis of 20 cases.

Twenty cases of malignant lymphomas (ML) of the oral cavity were reviewed in the light of recent histologic classification. They occurred in 12 male and 8 female patients, with the age range of 11-80 years (median 51 years of age). Eighty percent of patients were stages IE and IIE. Histologically, 15 cases (75%) were ordinary non-Hodgkin's lymphoma (NHL) with diffuse large cell type being the most common. The remaining 5 cases, undefinable by classification scheme for ordinary NHL, were designated as malignant histiocytosis of the oral cavity (3 cases) and peripheral T-cell lymphoma (2 cases), respectively. There were no cases of follicular lymphoma. The present cases comprised 45% of high grade, 40% of intermediate grade, and 15% of low grade malignancy. A follow-up study showed that the stage of diseage, histologic classification, and frequency of mitosis correlated well with survival.

Adolescent↗
PubMed1987

Plasma atrial natriuretic peptide and spontaneous diuresis in sick neonates.

Plasma concentrations of immunoreactive human atrial natriuretic peptide (human ANP) were sequentially determined in 12 infants with respiratory distress syndrome (RDS) or meconium aspiration syndrome (MAS) during various phases of diuresis to elucidate the role of human ANP in the occurrence of spontaneous diuresis in the newborn. Plasma immunoreactive ANP concentrations during the diuretic as well as the maximum diuretic phase were significantly (p less than 0.001) higher than during the prediuretic phase. A gradual decrease occurred during the post diuretic phase, returning to prediuretic values after one week of life. Significant natriuresis, increased glomerular filtration rate, mild hyponatremia, and decreased blood pressure were observed in the diuretic phase in all the cases studied. These results suggest that hypersecretion of human ANP may play an important part in initiating spontaneous diuresis in sick neonates.

Atrial Natriuretic Factor↗
PubMed1987

Reliability of urinary N-acetyl-beta-D-glucosaminidase as an indicator of renal tubular damage in neonates.

Urinary N-acetyl-beta-D-glucosaminidase (NAG) was determined in infants during the first year of life to clarify its evolutional change and the reliability of this enzyme as a marker of renal tubular damage in the newborn period. During the first 2 weeks of life, there was no difference in the urinary levels between preterm (gestational age of 33-36 weeks) and full-term infants. The urinary NAG index (NAG is expressed as the ratio of the enzyme activity to milligrams of creatinine) during the first month of life was significantly elevated when compared with that of any other succeeding period and gradually decreased during the first year of life. The index in newborn infants on tobramycin was significantly elevated and maintained a higher value during the 5 days after withdrawal of the medication. Infants with asphyxia had a higher urinary NAG index during the first week of life. These data suggest that the urinary NAG index is a useful indicator of renal tubular damage during the newborn period.

Acetylglucosaminidase↗
PubMed1987

Coronary arteritis in mice after systemic injection of bacterial cell wall peptidoglycan.

We examined cell wall peptidoglycan (PGL) derived from group A streptococcus and other bacteria for possible induction of coronary arteritis in mouse strains. The histological finding of the main trunk of the coronary arteries of BALB/c, DBA/1J, C57BL/6 and DBA/2 mice, which were given an intravenous injection of sonicated PGL fragments of st. pyogenes at 500 micrograms per mouse 4 times at intervals of 1 week, showed diffuse cellular infiltration in the vascular wall as well as perivascular space. Marked hyperplasia of the endothelial cells was noted and necrosis of the medial smooth muscle of the coronary artery also was observed. The elastica stain clearly demonstrated fragmentation and degeneration of the elastic fibers. The histological change of the originating site of the aorta also noted swelling or hyperplasia of the endothelial cells and perivascular cellular infiltration. PGL fragments of st. mutans, st. sanguis and s. aureus did not cause any heart lesions. Coronary arteritis induced by st. pyogenes PGL could be very useful as an experimental animal model of Kawasaki's disease.

Animals↗
PubMed1987

An experimental study of atherosclerosis as a sequela of coronary arteritis.

In order to examine the effect of corticosteroids on coronary atherogenesis in collagen diseases, an experimental study of serum sickness was performed. Forty-two rabbits were divided into four groups (Groups A-D). Group B, C and D rabbits received four intravenous injections of bovine serum albumin (250 mg/Kg) at 16-day intervals. Groups A, C and D rabbits were fed ad libitum cholesterol supplemented diet (1%) 16 days after the last injection. Group D rabbits received subdermal injections of prednisolone (1 mg/Kg) three times per week in the same period. After 124 days, all rabbits were sacrificed. Serum cholesterol and phospholipid increased in Group A, C and D rabbits. Group A rabbits showed intimal foam cell proliferation. Group B rabbits showed slight fibrous intimal thickening. The coronary arteries of Group C rabbits showed fatty-proliferative intimal thickening and an increase in the incidence of vascular lesions (13.9% of the coronary arteries as compared with 11.7% for Group A and 8.4% for Group B). The coronary lesions of Group D showed the same pattern as those of Group C, but the incidence of lesions was 6.0%. It was concluded that prednisolone did not augment immunologically induced atherosclerosis.

Animals↗
PubMed1987

Modulation of vascular dynamics by spontaneous contraction of smooth muscle in the isolated carotid artery of the rat.

Possible roles of smooth muscle contractions in the vascular dynamics were studied in the isolated rat large artery which has previously been shown to generate spontaneous rhythmic contractions depending upon the extracellular Ca2+. A cylindrical segment of the common carotid artery was superfused externally and perfused intraluminally by Tyrode solution, and the steady state intraluminal pressure (P)-volume (V) relationship of the vessel was obtained. The pressure buffering characteristic (Windkessel effect) of the vascular wall was evaluated by measuring the intraluminal pressure swing during application of external alternating pressure (semi-triangular pressure pulse, 0-120 mmHg, 300 cycle/min, "dynamic pressure load") to the intraluminal space. Effects on these vascular dynamics of inhibition of spontaneous smooth muscle contraction during superfusion of the preparation with nominally Ca2+-free Tyrode solution were investigated. Spontaneous rhythmic fluctuations of the intraluminal pressure (0.2-1.0 mmHg, 2-25 cycle/min), presumably due to contractions of vascular smooth muscles, were detected. The Ca2+-free solution abolished these spontaneous changes in the intraluminal pressure and reduced the baseline intraluminal pressure. The volume distensibility (delta V/(V X delta P] of the preparation at higher intraluminal fluid volumes (or pressures, higher wall stretch) was increased by Ca2+-free solution. The magnitude of intraluminal pressure swing and the maximum rate of changes in the pressure during application of "dynamic pressure load" were decreased in Ca2+-free solution. The results suggest that the inhibition of spontaneous contractions of smooth muscle by Ca2+-free solution may increase the volume distensibility and pressure-buffering function of the large elastic artery.

Animals↗
PubMed1987

[A case of B cell malignant lymphoma with in the liver and brain metastasis in Hashimoto's disease].

We have reported a case of malignant lymphoma in associated with Hashimoto's disease arising in the right lobe of thyroid of a 57-year-old woman. The pre-operative aspirated biopsy was valuable for diagnosis Immuno-histochemical observations revealed the localization of anti B cell antibody in the cell surface of lymphoma cells and anti thyroglobulin antibody in intactly follicular epithelium within the lymphoma tissue. This lymphoma was diagnosed as diffuse, medium cell and B cell type. Radiation and chemotherapy were performed for multiple metastasis of liver and brain, but this case had died of DIC and diffuse hyaline membrane disease of lung.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Effect of a histamine H2-receptor antagonist, famotidine, on gastric secretion in healthy subjects.

The effects of 20 mg of famotidine or placebo on secretion of gastric juice and gastric acid were studied in ten healthy subjects in a randomized, crossover study. Gastric juice was aspirated and collected at hourly intervals for 24 hours after oral administration, and acid output was calculated based on gastric juice output and acid concentration. Secretion of gastric juice and acid output were lower after famotidine was administered than after placebo; over the 12-hour post-administration period, the hourly acid concentrations were significantly lower after famotidine than after placebo. During the 12 hours after famotidine or placebo, gastric juice output was 180.7 +/- 32.1 ml (mean +/- SE) in the placebo group and 64.7 +/- 9.1 ml in the famotidine group (P less than 0.01); acid concentrations were 49.3 +/- 3.8 mmol/L in the placebo group and 9.6 +/- 3.1 mmol/L in the famotidine group (P less than 0.01); acid output was 8.89 +/- 1.59 mmol in the placebo group and 0.55 +/- 0.17 mmol in the famotidine group (P less than 0.01). These results support the effectiveness of a 12 hour or possibly a 24-hour dosing interval for famotidine.

Administration, Oral↗