Search PubMed⌕ Search

Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 991 records · Page 55Linked to original sources
PubMed1983

An autopsied case of a two-month-old infant with granulomatous pancarditis having severe vasculitis and valvulitis.

A 2-month-old female infant with pancarditis was reported. The patient died after a 26-day clinical course. The autopsy showed pancarditis, including inflammation in all 4 valves and chordae, fibrinoid vasculitis, pharyngolaryngitis and atrophy of the lymph nodes. Microscopic examination revealed proliferative inflammation in the endocardium, valve, myocardium, epicardium and coronary vessels. The histological findings suggested the etiology to be a rheumatic-type reaction at an extremely young age.

Arteritis↗
PubMed1983

Effects of hypocapnia on respiratory timing and inspiratory activities of the superior laryngeal, hypoglossal, and phrenic nerves in the vagotomized rat.

Effects of acute hypocapnia on respiratory timing (inspiratory and expiratory times (TI, TE) ) and on inspiratory activities of the efferent superior laryngeal (Xs1), hypoglossal (XII), and phrenic (Phr) nerves were studied in artificially ventilated vagotomized, and anesthetized rats. Hyperventilation induced a decrease in respiratory frequency exclusively due to prolongation of TE and resulted in expiratory apnea. Inspiratory activities of three nerves decreased with reduction in CO2 concentration of end-tidal gas (FETCO2), and disappeared simultaneously at a threshold FETCO2 for apnea. The decrease in the peak inspiratory activity by hypocapnia was larger in the XII than in the Phr or Xs1 nerve (XII greater than Phr greater than Xs1). The results suggest that the CO2 stimulus (mainly via a central chemosensor) plays an important role in the process of terminating expiration or of expiratory-inspiratory phase switching and that the responses of the XII or Xs1 motoneurons to variation in CO2 stimulus differ from that of the Phr motoneurons (or of the Phr driving medullary neurons). A possible functional significance of these observations is discussed.

Afferent Pathways↗
PubMed1983

Light and electron microscopic studies of phrenic nerves after long-term electrical stimulation.

Light and electron microscopic evaluation were carried out on canine phrenic nerves subjected to long-term electrical stimulation. A total of 34 stimulated and 19 control nerves were studied by light microscopy, and 10 stimulated and five control nerves were evaluated by electron microscopy. Except in a few cases in which a higher current was used, the current used for stimulation was between 1 and 2 mA. The pulse width was 150 microseconds. The typical charge per pulse was 0.22 microC and charge density per pulse 1.125 microC/sq cm of real area. The total number of days of electrical stimulation in individual phrenic nerves ranged from 4 to 374. No morphological changes in the phrenic nerve that could be attributed to the electrical stimulation were observed by light or electron microscopic study. There were, however, two phrenic nerves cuffed with bipolar electrodes which showed focal demyelination at the electrode level, but these changes were caused by factors other than the electrical stimulation. The results of the studies have direct clinical implications to long-term stimulation of phrenic nerves.

Animals↗
PubMed1983

Response of the diaphragm muscle to electrical stimulation of the phrenic nerve. A histochemical and ultrastructural study.

The histological, histochemical, and ultrastructural features of canine diaphragms subjected to pacing by high-frequency electrical stimulation (27 to 33 Hz) of the phrenic nerve are compared with unstimulated diaphragms and with diaphragms subjected to pacing by low-frequency stimulation (11 to 13 Hz). The high-frequency group showed a reduced tidal volume (fatigue) after long-term stimulation, and myopathic changes which included enlarged internal and sarcolemmal nuclei, ring fibers, moth-eaten fibers with irregular histochemical staining, core/targetoid fibers, and smearing and aggregation of Z-band material with electron microscopy. The low-frequency group did not develop a significant degree of fatigue or pathological changes, and showed histochemical evidence of transformation to fast-twitch (type II) fibers. Possible pathogenic mechanisms and their similarity to those in certain human neuromuscular diseases are discussed. The application of the findings resulting from high- and low-frequency stimulation to long-term diaphragm pacing in humans with chronic ventilatory insufficiency is also discussed.

Animals↗
PubMed1983

[Anticancer regimen combined with methylprednisolone--its antiemetic effect].

Methylprednisolone was given to 8 patients receiving CDDP-containing chemotherapy. Of 8 patients, 7 patients achieved complete relief of nausea and emesis and 1 patient obtained partial elimination of symptoms. All these patients had consistent history of severe nausea and emesis before the methylpredisolone trial. At present, a potential effect of methylprednisolone on chemotherapy has not been known. In a case of testicular cancer the titer of tumor markers decreased straight on a table of logarithms.

Adult↗
PubMed1982

CO2-ventilatory response of the anesthetized rat by rebreathing technique.

The ventilatory response to CO2 in rats under sodium pentobarbital anesthesia has been measured using the rebreathing technique. The animal rebreathed through a tracheal cannula for a period of 4 min from an apparatus of 200-400 ml capacity, containing 5-6% CO2 in O2. Pco2 in the rebreathing apparatus (PappCO2), instantaneously Vt, f, and Ve were monitored before, during, and after rebreathing. During the rebreathing run, PappCO2 and Paco2 rose linearly from 35-40 to 65-70 mm Hg; there was no significant difference between PappCO2 and Paco2 at any time during rebreathing. Vt and Ve increases almost linearly with the rise of PappCO2, while f increased to a maximum within 2 min of rebreathing. In the rat, Vt regulation seemed to operate exclusively as a proportional control system in response to linearly increasing CO2 stimulus. The slopes of PappCO2, Vt or Ve response curves varied considerably during the time course of the experiment, depending upon the level of anesthesia, even though there was no large change in Ve in the control periods which were under hyperoxic conditions. However, a significant linear relationship was seen between f in the respective control period and the slope of PappCO2-Vt response at various levels of anesthesia. We concluded that the rebreathing technique can be applied in small experimental animals and that changes in the sensitivity of the respiratory control system to a CO2 stimulus by anesthesia can be easily monitored by repeating the rebreathing test.

Anesthesia, General↗
PubMed1982

Effect of halothane anesthesia on end-tidal PCO and pattern of respiration in the rat.

End-tidal Pco2 (petco2) and ventilation of the rat anesthetized with halothane were measured. The Petco2 measured by an infrared analyzer agreed well with the simultaneously measured Paco2 in the range from 20-60mm Hg (2.7-8.0 kPa). When the level of anesthesia was deepened by increasing the halothane concentration from 0.9-3.0%, minute ventilation was decreased progressively accompanied by a rise in Petco2 and the CO2 output was reduced. Halothane induced a progressive decrease in frequency of respiration (f) with almost constant or even slight increase in tidal volume (VT)). Decrease in f was caused largely by the prolongation of expiratory duration (TE). Changes in inspiratory duration (T1) were small and the mean VT/T1 ratio remained unaltered at different levels of anesthesia. These changes in respiratory pattern induced by halothane anesthesia contrasted with the simultaneous decrease in VT, f and VT/T1 ratio and apparent changes of both T1 an TE reported in other species. Species differences in effects of anesthesia on ventilation were discussed. Restraining the rat on a stereotaxic apparatus with head holders, especially with ear bars, elicited an initial transient stimulation of ventilation which was followed by a strong depression.

Anesthesia, General↗
PubMed1982

Immune complex-mediated glomerulonephritis and interstitial pneumonia simulating Goodpasture's syndrome.

An autopsy case of what was clinically considered to be Goodpasture's syndrome was investigated. The lung had hemorrhagic interstitial pneumonia, showing granular patterns of IgG and C3 along the alveoli by the immunofluorescent method and electron-dense subepithelial deposits by electron microscopy. The kidney had crescentic and segmental necrotizing glomerulonephritis associated with membranous nephropathy. Uneven, continuous patterns of immunofluorescent IgG and C3 along the GBM were noted. Electron microscopy showed numerous subepithelial deposits, and immunoelectron microscopy revealed that IgG was not present in the GBM itself but present in the subepithelial deposits. Anti-GBM antibody activity was not detected in the serum or the kidney eluate. It was suggested that renal and pulmonary lesions occurred through the same mechanism and in association with immune deposits. We propose that there is a disease having immune complex-mediated deposits. We propose that there is a disease having immune complex-mediated renal and pulmonary lesions which clinically resembles the conventional Goodpasture's syndrome.

Adult↗
PubMed1982

Renal glomerular changes associated with liver cirrhosis.

Renal glomerular changes associated with 79 liver cirrhosis cases were studied by light and electron microscopy, and immunofluorescent methods. The glomerular changes were classified as follows: 1) Mixed membranous and proliferative glomerulonephritis type having subepithelial, subendothelial, mesangial and paramesangial deposits (37 cases), 2) membranous glomerulonephropathy type (6 cases), 3) IgA nephropathy type (3 cases), and 4) glomerulosclerosis types (5 cases). Clinically, the patients with marked renal glomerular changes and proteinuria, hematuria, and retention by the PSP test. It was suggested that the essential renal glomerular changes in liver cirrhosis was immune-complex mediated glomerulonephritis and that glomerular sclerosis was merely a secondary change to glomerulonephritis.

Fluorescent Antibody Technique↗