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Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 469 records · Page 26Linked to original sources
PubMed1995

Electrophysiological properties of phrenic motoneurons in adult rats.

Electrophysiological properties of phrenic motoneurons (PMs) were studied by intracellular recordings in anesthetized, paralyzed, and artificially ventilated adult rats. Our results revealed that rat PMs, as compared to cat PMs, had a shorter afterhyperpolarization duration (55 +/- 13 ms; mean +/- SD), a narrower half-width of action potential, a larger membrane input resistance (Rm; 2.0 +/- 0.6 M omega), a smaller rheobase (Irh) and a shorter minimum paired pulse interval to provoke the second spike (1.9 +/- 0.6 ms). These features indicate that the rat PMs possess higher frequency responsiveness than cat PMs. Based on the time of firing onset relative to the onset of whole phrenic nerve activity (relative onset time; ROT) or on the absence of discharge during inspiration, the PMs could be classified into four types: early recruited with ROT < 10.0%; late recruited with 12.5% < ROT < 37.5%; very late recruited with ROT > 45%, and quiescent which was not recruited during normal experimental conditions. A number of differences in the membrane properties such as end-expiratory membrane potential, Rm, and Irh among the four cell types are discussed in relation to the recruitment order. Inhibitory postsynaptic potentials (IPSPs) were present during the late expiratory phase (stage II expiration) in all PMs tested.

Animals↗
PubMed1995

[Giant cell interstitial pneumonia in a metal grinder with an abnormally high level of serum CA19-9].

Interstitial pneumonia and recurrent pneumothorax developed in a 48-year-old man who had worked as a metal grinder. He died of respiratory failure despite having received antibiotics and steroids, and despite having undergone pleural sclerosis therapy. Giant cell interstitial pneumonia was diagnosed; innumerable bizarre giant cells engulfing black granules were found within the alveoli. The results of high-energy dispersion X-ray microanalysis indicated that the patient had hard metal pneumoconiosis associated with tungsten in the black granules. When he was admitted to the hospital, his serum CA19-9 and SLEX concentrations were abnormally high (2600 and 200 ng/ml, respectively). Immunohistochemical analysis of lung tissue was done with anti-CA19-9 and SLEX antibodies. CA19-9 staining revealed strong bronchialization and squamous metaplasia in contrast to type II hyperplasia. SLEX staining showed strong type II hyperplasia. Further investigations will be needed to determine the mechanism of elevated tumor-associated carbohydrate antigens in serum.

Biomarkers, Tumor↗
PubMed1995

Inspiratory activity responses to lung inflation and ventral medullary surface cooling of glossopharyngeal nerve (stylopharyngeal muscle branch) and its motoneuron distribution in the rat.

Inspiratory (I) discharges of the phrenic (Phr) and glossopharyngeal (stylopharyngeal muscle branch, IX) nerves were compared in the urethane anesthetized, vagi-intact and artificially ventilated rat in which respiratory rhythm was generated in synchrony with cyclic changes in airway pressure (P(aw)) produced by a ventilator. Observations were made during respiratory suppression due to excess lung inflation and bilateral cooling of the ventral medullary surface (VMS). In the control condition, regular rhythmic I bursts appeared at low baseline P(aw) phase (lung deflation) and ceased when P(aw) increased (lung inflation) in each ventilator cycle. Increase in baseline P(aw) (P(aw) > 8 cmH2O, excess lung inflation) suppressed the initiation of rhythmic I discharge. However, threshold baseline P(aw) for suppressing I bursts was higher in the IX than in the Phr nerve, and regular rhythmic I activity remained in the IX even after cessation of Phr bursts. During VMS cooling, I bursts disappeared first in the Phr and subsequently in the IX nerve and emerged always first in the IX during recovery. The results suggest that I activity of the IX (stylopharyngeal) motoneurons, which are located in the rostral part of the nucleus ambiguus, are less suppressed than that of Phr motoneurons by vagal afferents arising probably from slowly adapting pulmonary stretch receptors or by a reduction in respiratory drive from VMS. These differential responses of Phr and IX motoneurons may be ascribed to differences in activation or inhibition processes between two motoneuron groups despite both being driven by a common rhythm generator.

Action Potentials↗
PubMed1995

[Mechanism of renal excretion of T-3761, a novel fluoroquinolone agent, in rabbits].

The mechanism of the renal excretion of T-3761, a novel oral fluoroquinolone agent, was studied by renal clearance, stop-flow techniques and analyzing the pharmacokinetics with and without probenecid in rabbits, and which were compared with those of ofloxacin (OFLX). In rabbits probenecid treatment induced increases in the elimination half-life (2.1 times higher) and area under the serum concentration-time curve (3.1 times), and decreases in elimination rate constant (0.44 times) and total body clearance (0.35 times), while volume of distribution showed no significant change. In the stop-flow pattern, a specific peak of T-3761 was observed. On the other hand, a peak of OFLX was observed at the peak of PAH and a small trough at the trough of sodium. And the renal clearance of T-3761 and OFLX were about 4.9 and 3.3 times higher than the corresponding Clcr, respectively. These results suggested that T-3761 was excreted into urine by both glomerular filtration and renal tubular secretion, and was scarcely reabsorbed at distal tubule. The short elimination half-life of T-3761 might be explained by its great ratio of tubular excretion.

Animals↗
PubMed1995

[MR imaging of infected spondylodiskitis: interval signal change in vertebral body (including enhanced image of vertebral body)].

A retrospective evaluation of MRI was carried out in 22 patients with spondylodiskitis. Low signal intensity on T1-weighted images and high or low signal intensity on T2-weighted images were observed. Sixteen patients underwent follow-up examinations after the initial examination. Various signal changes in the vertebral body were recognized. The longer the period of follow-up, the less abnormal the signal intensity became on both T1- and T2-weighted images. Several cases showed no change in signal intensity. In all of 17 patients re-examined after injection of Gd-DTPA, infected vertebral bodies were enhanced. We classified the enhancing patterns of infected vertebral bodies in three types: A) homogeneous, B) homogeneous with strong enhancement adjacent to the end plate, C) inhomogeneous. Pyogenic spondylodiskitis tended to show patterns A or B, and tuberculous spondylodiskitis pattern C. The enhancement effect disappeared after normalization or remission of laboratory findings. In two cases, the enhancement effect remained even after laboratory findings became normal. Contrast MRI was useful for understanding infectious state.

Adolescent↗
PubMed1995

Efficacy of nutritional therapy for active Crohn's disease.

We investigated the effect of nutritional therapy with an elemental diet (ED) for active Crohn's disease. One hundred and thirty-nine patients with Crohn's disease were enrolled in this study. Remission was judged to be present when the International Organization of Inflammatory Bowel Disease score was < or = 1 and the CRP and ESR values were within the respective normal ranges. An amount of 30kcal per 1kg of ideal body weight (IBW) per day was administered enterally, and the effect on the induction of remission in relation to various patient background factors, such as disease type, history of bowel resection, and the presence/absence of complications, was determined. An excellent remission rate was achieved in those patients to whom an adequate amount of ED could be administered. Remission rates were lower in the patient groups with any of the following complications: stenotic bowel lesions, abdominal masses, fistulas, and anal lesions. Even in those groups in which stenotic lesions or abdominal masses were present, when adequate amounts of ED could be administered, the remission rate did not differ from that in the groups without these complications. The remission rates in the groups with and without fistulas at any site, including fistulas in the anal region, were 40.0% and 82.5%, respectively, with remission being considerably easier to achieve in the patients without fistulas. Similarly, remission was difficult to achieve when anal lesions were present. These results suggest that, for active Crohn's disease, nutritional therapy with ED ( > or = 35kcal/kg IBW) should be enthusiastically administered, and in patients in whom the presence of complications necessitates therapy for 3 months or more, this point be considered to indicate a possible surgical approach.

Adult↗
PubMed1995

Combination therapy with mucosal protective agent for the eradication of Helicobacter pylori.

OBJECTIVE: To investigate the effect of plaunotol in combination with proton-pump inhibitors on Helicobacter pylori eradication in patients with gastric ulcer. PATIENTS AND METHODS: We studied 65 H. pylori-positive gastric ulcer patients. They were randomly assigned to five treatment groups: omeprazole (group I, n = 8), lansoprazole (group II, n = 13), lansoprazole+plaunotol (group III, n = 12), lansoprazole+clarithromycin (group IV, n = 16) and lansoprazole+plaunotol+clarithromycin (group V, n = 16). Ulcer status was diagnosed by endoscopy and H. pylori status by culture, histology, a urease test and a urea breath test at baseline, and after 8 and 12 weeks. The clearance and eradication rates were compared in each group. RESULTS: The healing rates in groups I-V were 100, 92, 100, 100 and 100%, respectively; clearance rates were 0, 23, 42, 50 and 75%, respectively; and eradication rates were 0, 0, 8, 38 and 69%, respectively. CONCLUSION: Combination therapy with plaunotol is efficacious for the eradication of H. pylori in gastric ulcer patients.

Anti-Bacterial Agents↗