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Biomedical subjects

M Yanai

Publications and source records attributed to M Yanai.

At least 19 recordsLinked to original sources
PubMed1992

Site of airway obstruction in pulmonary disease: direct measurement of intrabronchial pressure.

To partition the central and peripheral airway resistance in awake humans, a catheter-tipped micromanometer sensing lateral pressure of the airway was wedged into the right lower lobe of a 3-mm-ID bronchus in 5 normal subjects, 7 patients with chronic bronchitis, 8 patients with emphysema, and 20 patients with bronchial asthma. We simultaneously measured mouth flow, transpulmonary pressure, and intra-airway lateral pressure during quiet tidal breathing. Total pulmonary resistance (RL) was calculated from transpulmonary pressure and mouth flow and central airway resistance (Rc) from intra-airway lateral pressure and mouth flow. Peripheral airway resistance (Rp) was obtained by the subtraction of Rc from RL. The technique permitted identification of the site of airway resistance changes. In normal subjects, RL was 3.2 +/- 0.2 (SE) cmH2O.l-1.s and the ratio of Rp to RL was 0.24 during inspiration. Patients with bronchial asthma without airflow obstruction showed values of Rc and Rp similar to those of normal subjects. Although Rc showed a tendency to increase, only Rp significantly increased in those patients with bronchial asthma with airflow obstruction and patients with chronic bronchitis and emphysema. The ratio of Rp to RL significantly increased in three groups of patients with airflow obstruction (P less than 0.01). These observations suggest that peripheral airways are the predominant site of airflow obstruction, irrespective of the different pathogenesis of chronic airflow obstruction.

Adult↗
PubMed1992

Effective site of bronchodilation by beta-adrenergic and anticholinergic agents in patients with chronic obstructive pulmonary disease: direct measurement of intrabronchial pressure with a new catheter.

To study the effective site of bronchodilators in patients with chronic obstructive pulmonary disease (COPD), a catheter tip micromanometer sensing lateral pressure of the airway was wedged into the right lower lobe of a bronchus, 3 mm inner diameter, in 14 patients with COPD. We simultaneously measured mouth flow, transpulmonary pressure (PL) and intra-airway lateral pressure during quiet tidal breathing. Total pulmonary resistance (RL) was calculated from PL and mouth flow, and central airway resistance (RC) was calculated from intra-airway lateral pressure and mouth flow. Peripheral airway resistance (RP) was obtained by the subtraction of RC from RL. This technique permitted identification of the site of changes in airway resistance. Atropine sulfate (5 mg/ml) was continuously inhaled during tidal breathing for 1 min by seven patients (Group A), and the other seven patients (Group B) inhaled fenoterol (1 mg/ml) for 1 min. The doses that were actually delivered were 0.75 mg for atropine sulfate and 0.15 mg for fenoterol. The baseline resistances of RC and RP were 3.9 +/- 0.8 and 3.7 +/- 0.6 cm H2O/L/s in Group A, and 4.3 +/- 0.5 and 3.5 +/- 0.4 cm H2O/L/s in Group B, respectively. Both atropine sulfate and fenoterol significantly decreased RL by an average of 2.4 and 2.6 cm H2O/L/s, and there was no significant difference between them (p greater than 0.20). The percentage decrease in resistance from the baseline values by fenoterol did not differ significantly between RC and RP (p greater than 0.20). However, atropine sulfate significantly decreased RC more than RP.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1992

Partitioning of pulmonary responses to inhaled methacholine in subjects with asymptomatic asthma.

To partition the central and peripheral airway resistance, a catheter-tip micromanometer sensing lateral pressure of the airway was wedged into the right lower lobe of a bronchus with a 3 mm inner diameter in 10 patients with asymptomatic asthma. We simultaneously measured mouth flow, transpulmonary pressure (PL) and intra-airway lateral pressure during tidal breathing. Total pulmonary resistance (RL) was calculated from PL and mouth flow, and central airway resistance (RC) was calculated from intra-airway lateral pressure and mouth flow. Peripheral airway resistance (Rp) was obtained by subtraction of RC from RL. Therefore, our measurement of Rp included lung tissue resistance. The technique permitted identification of the site of changes in airway resistance. The baseline values of resistances were 2.3 +/- 0.2 cm H2O/L/s in RL, 1.5 +/- 0.1 cm H2O/L/s in RC, and 0.8 +/- 0.1 cm H2O/L/s in Rp, respectively. To determine the site of airway hyperresponsiveness, dose-response curves of central, peripheral, and total airways to inhaled methacholine were separately constructed. Bronchial responsiveness was evaluated by a log methacholine unit requiring a 35% decrease (PC35) and a 50% decrease (PC50) in pulmonary conductance (a reciprocal of RL). We calculated the increase of resistances in total (delta RL), central (delta RC), and peripheral (delta Rp) airways from the baseline values at either PC35 or PC50.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Methylguanidine kinetics during oral active vitamin D pulse therapy for secondary hyperparathyroidism].

Active vitamin D (VD) metabolite preparations have been used in the management of secondary hyperparathyroidism (2 degrees HPT) due to impaired calcium and phosphorus metabolism and can allegedly be expected to prevent, to some extent, the progression of this pathological condition. Unfortunately, however, it is not uncommon for us in routine clinical practice to find 2 degrees HPT of moderate or greater severity embarrassingly unamenable to treatment with these VD preparations in ordinary oral therapeutic doses. Recent studies have gradually reported that intravenous administration of 1,25-(OH)2D3 and oral active VD pulse therapy has been therapeutic approach to 2 degrees HPT. Methylguanidine (MG) among other GCs, its precursor is already identified as creatinine and activated oxygen as well PTH and VD are known to participate in the process leading to its formation. In the present study, we administered oral 1,25-(OH)2D3 pulse therapy to patients with chronic renal failure for the treatment of 2 degrees HPT in an attempt to assess the effectiveness of this therapeutic regimen and to explore the clinical effect of MG on responsiveness to the therapy. The purpose of this paper is to present the results thus obtained. Oral 1,25-(OH)2D3 pulse therapy (6 micrograms once a week) was administered to 21 hemodialysis patients with for 12 weeks. Of these 21, 10 patients responded to the therapy with a more than 20% reduction in serum (PTH): (responsive group), whereas the remaining 11 did not (resistant group). Pretreatment serum PTH levels were significantly higher in the latter group than the former.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Evaluation of parameters for adequate dialysis therapy: (2). Comparison between parameters according to UKM and other laboratory data.

Urea kinetic modeling (UKM) is often regarded as the best method for assessing the dialysis adequacy and consequently for the prescription of treatment time. However, other parameters are involved in the monitoring of end stage renal disease (ESRD) patients. Kt/V-urea and protein catabolic rate (pcr) were evaluated in 53 ESRD patients (25 males and 28 females; mean age, 60 +/- 2 years old; mean duration, 80 +/- 11 months), twice at an interval of 4 months, and pre-dialysis concentration of (pre-DC) plasma potassium, bicarbonate, calcium and phosphate were measured. The pre-dialysis systolic blood pressure and hematocrit were also recorded. The numbers of patients who were within the optimal range of Kt/V-urea and pcr recommended by Gotch and Sargent were 36 (67.9%) and 39 (73.6%), respectively, at the first control period, and 39 (73.6%) and 44 (83.0%) at the second control period. However, only about 50% of the patients were within the optimal range of pre-DC plasma calcium, phosphate and bicarbonate. Furthermore, very few patients fulfilled the conditions for all the parameters. It is concluded that (1) UKM is required to describe the domain of dialysis prescription, and (2) other parameters which are not dependent so much on dialysis should be taken into account for assessing the adequacy of dialysis.

Blood Chemical Analysis↗
PubMed1991

Nicotine improves cognitive disturbance in rodents fed with a choline-deficient diet.

The effect of nicotine on learning disturbances was tested in rats. Rats were fed either a choline-enriched or a choline-deficient diet. Concentration of acetylcholine in the whole brain was significantly lower in rats fed with choline-deficient diet than rats fed with choline-enriched diet. Passive avoidance learning shows that rats on a choline-deficient diet showed significantly impaired learning compared to rats on a choline-enriched diet. Nicotine (0.04 mg/kg) administered intraperitoneally significantly potentiated learning in rats on a choline-deficient diet, as well as in rats on a choline-enriched diet. We, therefore, suggest that nicotine may potentiate learning in an acetylcholine-deprived brain.

Acetylcholine↗
PubMed1991

Effective site of bronchodilation by antiasthma drugs in subjects with asthma.

We studied the effective sites of airway response to atropine and fenoterol aerosols and to the intravenous injection of aminophylline in patients with stable and spontaneous asthma, by the simultaneous assessment of respiratory resistance (Rrs) and anatomic dead space (VD). Central airway response was determined by VD, and overall response was determined by Rrs. Peripheral airway response was inferred from Rrs when the change in VD was slight. Atropine (4 mg/ml) or fenoterol (0.4 mg/ml) was continuously inhaled during tidal breathing for 5 minutes. Inhalation of both atropine and fenoterol increased Grs (reciprocal of Rrs) (p less than 0.01) with a simultaneous increase in VD (p less than 0.01) in the patients with stable and spontaneous asthma. Fenoterol increased Grs more than did atropine at an equivalent increase in VD in patients with spontaneous asthma (p less than 0.05). Intravenous injection of aminophylline (250 mg) had no effect on either Grs or VD in patients with stable asthma, but it significantly increased Grs (p less than 0.01) without change in VD in patients with spontaneous asthma. These results suggest that the predominant sites of bronchodilation induced by inhaled atropine are the central airways, that those sites induced by intravenous injection of aminophylline are the peripheral airways, and that inhaled fenoterol dilates both the central and peripheral airways in subjects with asthma. Differences among clinically used bronchodilators on the effective sites may be considered in the treatment of bronchial asthma.

Adult↗
PubMed1991

The analysis of the defense mechanism against indigenous bacterial translocation in X-irradiated mice.

The defense mechanism against indigenous bacterial translocation was studied using a model of endogenous infection in X-irradiated mice. All mice irradiated with 9 Gy died from day 8 to day 15 after irradiation. The death of mice was observed in parallel with the appearance of bacteria from day 7 in various organs, and the causative agent was identified to be Escherichia coli, an indigenous bacterium translocating from the intestine. Decrease in the number of blood leukocytes, peritoneal cells and lymphocytes in Peyer's patches or mesenteric lymph nodes was observed as early as 1 day after irradiation with 6 or 9 Gy. The mitogenic response of lymphocytes from various lymphoid tissues was severely affected as well. The impairment of these parameters for host defense reached the peak 3 days after irradiation and there was no recovery. However, in vivo bactericidal activity of Kupffer cells in mice irradiated with 9 Gy was maintained in a normal level for a longer period. It was suggested that Kupffer cells play an important role in the defense against indigenous bacteria translocating from the intestine in mice.

Animals↗
PubMed1991

Evaluation of parameters for adequate dialysis therapy: (1). Monitoring of parameters by urea kinetic modeling.

In an attempt to evaluate the adequacy of regular dialysis therapy, calculations of Kt/V-urea and protein catabolic rate (pcr) from the data of routine laboratory examinations by means of urea kinetic modeling were performed in 59 regular dialysis patients (28 males and 31 females; mean age, 59 +/- 2 years old; mean dialysis duration, 83 +/- 10 months). The mean values of Kt/V-urea and pcr were 1.10 +/- 0.04 and 0.98 +/- 0.03 g/kgBW.day, respectively. The number of patients who were within the optimal range (0.9-1.4 for Kt/V urea and 0.9-1.5 for pcr) was 37 (62.7%) for Kt/V-urea and 38 (64.4%) for pcr. Furthermore, we inferred that, based on an appropriate dietary protein intake, removal of urea by intermittent dialysis should be adjusted to maintain the patient in equilibrium for a defined pre-dialysis plasma urea concentration. From the data obtained, we concluded that: (1) it is possible to apply urea kinetic modeling on the basis of routine laboratory examinations, (2) it is important to maintain the pre-dialysis plasma urea concentration at more than a certain level, and (3) it is also important to control the post-dialysis plasma urea concentration at a low level.

Creatinine↗
PubMed1991

[No rearrangement of the breakpoint cluster region in two juvenile chronic myeloid leukemia].

We performed cytogenetic studies and breakpoint cluster region (bcr) rearrangement analysis in two cases of juvenile chronic myeloid leukemia (JCML) which is special type of chronic myeloid leukemia (CML). Case 1 (8-month-old male) and case 2 (3-month-old female) showed clinical and hematologic manifestations similar to CML. Each of case 1 and 2 had normal karyotype and no bcr rearrangement. These findings suggest that JCML is a different heterogeneous disorder from that of adult CML.

Female↗
PubMed1991

Pharmacokinetics and optimum dose of disopyramide in patients with chronic renal failure.

The pharmacokinetics and optimum dose for maintenance of disopyramide (DP) which is effective against arrhythmia were studied in patients with chronic renal failure (CRF, n = 10), who had a creatinine clearance (Ccr) less than 30 ml/min. The plasma concentrations (PC) of DP and mono-isopropyl-disopyramide (MDP) an active metabolite of DP, were measured by high performance liquid chromatography. Samples from patients and controls were obtained at 0, 1, 2, 3, 4, 6, 8, 12, 24, 33, and 48 hr after oral administration (OA) of 100 mg DP. The pharmacokinetic parameters were calculated using a two-compartment model. In CRF, the plasma half life (T 1/2) of DP was 5.25 to 22.42 hr (average is 12.45 hr) and that of MDP was 5.09 to 131.66 hr (average is 16.9 hr). In normal controls, the T 1/2 of DP was 6.05 hr, but that of MDP could not be determined the available sensitivity of measurement. T max was 3.11 hr at the total PC of DP and MDP, and C max was 2.48 g/ml on average. In conclusion, the present study revealed that: (1) the PC of a mixture of DP and MDP should rise following OA of DP every 8 or 12 hr in CRF; (2) it is necessary therefore to monitor the accumulation of MDP after rolling OA of DP; and (3) OA of DP every 24 hr can maintain an effective PC.

Administration, Oral↗
PubMed1991

A small airway pressure sensor for humans.

We developed a small airway pressure sensor for humans. This sensor catheter was introduced to the right lower lobe bronchus through a fiberoptic bronchoscope until the tip was wedged, at which point the bronchoscope was removed. We measured small airway pressure using this sensor. Simultaneously, we measured mouth flow, mouth pressure and transpulmonary pressure by the esophageal balloon technique during tidal breathing. The present method is called an anterograde method. By this method, we obtained central airway resistance and peripheral airway resistance. A significant increase in peripheral airway resistance, compared to normal subjects, has been confirmed as a symptom of chronic obstructive pulmonary disease.

Airway Resistance↗
PubMed1990

Pernicious anemia in a patient with hypogammaglobulinemia.

A 19-year-old male with pernicious anemia and hypogammaglobulinemia (common variable immunodeficiency: CVID) is reported in comparison with classical pernicious anemia. This case was characterized by an earlier onset of anemia, the absence of autoantibodies to intrinsic factor or gastric parietal cells and involvement of the pyloric antrum as well as the gastric corpus. It is suggested that dysregulation of cellular immunity produces the autoimmune lesion in the gastric mucosa, including the pyloric antrum, in a patient with CVID, and that some of such cases develop pernicious anemia.

Adult↗
PubMed1990

Ozone increases susceptibility to antigen inhalation in allergic dogs.

To determine whether O3 exposure increased airway responsiveness to antigen inhalation, we studied airway responsiveness to acetylcholine (ACh) and Ascaris suum antigen (AA) before and after O3 in dogs both sensitive and insensitive to AA. Airway responsiveness was assessed by determining the provocative concentration of ACh and AA aerosols that increased respiratory resistance (Rrs) to twice the base-line value. O3 (3 parts per million) increased airway responsiveness to ACh in dogs both sensitive and insensitive to AA, and it significantly decreased the ACh provocation concentration from 0.541 +/- 0.095 to 0.102 +/- 0.047 (SE) mg/ml (P less than 0.01; n = 10). AA aerosols, even at the highest concentration in combination with O3, did not increase Rrs in dogs insensitive to AA. However, O3 increased airway responsiveness to AA in AA-sensitive dogs and significantly decreased log AA provocation concentration from 2.34 +/- 0.22 to 0.50 +/- 0.17 (SE) log protein nitrogen units/ml (P less than 0.01; n = 7). O3-induced hyperresponsiveness to ACh returned to the base-line level within 2 wk, but hyperresponsiveness to AA continued for greater than 2 wk. The plasma histamine concentration after AA challenge was significantly higher after than before O3 (P less than 0.01). Intravenous infusion of OKY-046 (100 micrograms.kg-1.min-1), an inhibitor of thromboxane synthesis, inhibited the O3-induced increase in responsiveness to ACh, but it had no effects on the O3-induced increase in responsiveness to AA and the increase in the plasma histamine concentration. These results suggest that O3 increases susceptibility to the antigen in sensitized dogs via a different mechanism from that of O3-induced muscarinic hyperresponsiveness.

Acetylcholine↗
PubMed1990

Allergic sensitization in elderly patients with chronic obstructive pulmonary disease.

To study whether allergic sensitization occurs in elderly patients with chronic pulmonary obstructive disease (COPD), we examined serum IgE and skin test reactivity to allergens in three age-matched groups of normal subjects, and in patients with COPD and bronchial asthma (BA). Serum IgE was significantly higher in patients with COPD and BA than in normal subjects (p less than 0.05), and patients with COPD showed serum IgE levels as high as those of patients with BA. However, the skin test scores were significantly higher in patients with BA than in normal subjects and patients with COPD (p less than 0.05). Neither serum IgE nor skin test score significantly correlated with FEV1%, PaO2, PaCO2 or Brinkman's Index in any group (p greater than 0.20). These results suggest that allergic sensitization occurs in elderly patients with COPD and that symptoms associated with COPD may be partly due to allergic inflammation.

Asthma↗
PubMed1990

Permanent brain damage possibly caused by theophylline in two elderly patients with airway obstruction.

Two aged patients with bronchial asthma and chronic obstructive pulmonary disease who suffered convulsions that resulted in permanent brain damage during treatment with the recommended therapeutic dose of theophylline are presented here. A dose or concentration of theophylline lower than the recommended one should be considered in the treatment of some aged patients with pulmonary obstructive disease.

Aged↗