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Biomedical subjects

H Katayama

Publications and source records attributed to H Katayama.

At least 163 records · Page 9Linked to original sources
PubMed1996

Anaphylactic IgE and IgG1 production for hapten can be enhanced by contrast media.

Various side effects have been associated with the clinical use of contrast media. Immunological mechanisms have been proposed but there have been very few experimental studies with animal models. We have attempted to develop murine models to determine whether or not anaphylactic antibodies such as IgE and IgG1 against hapten (DNP) were enhanced with contrast medium (iopamidol) as an adjuvant or if the contrast medium itself produced antibodies of the IgE class. The results showed that anti-hapten IgE and IgG1 production was greatly enhanced with immunogen plus contrast medium. Anti-contrast medium antibodies of the IgE class could not be detected by PCA reactions. The enhancement of IgE and IgG1 production for hapten was associated with IL-4 release by the neutralization test used by monoclonal anti-IL-4 antibodies. This is the first observation to show that contrast media may have a strong adjuvant effect for the production of IgE and IgG1. This murine model demonstrates a possible immunological function of contrast media in vivo.

Anaphylaxis↗
PubMed1996

Quantitative comparison between serum components and somatic cells in bovine quarter milk.

Quantitative comparisons between serum components and somatic cells in 202 bovine quarter milks collected at 3 dairy farms were conducted. Detection of serum components was carried out by an immunological technique, and cell counts were calculated by Breed's method. A high correlation (r = 0.77) between cell counts and gamma-globulin contents was demonstrated, while correlation between cell counts and serum albumin was not close (r = 0.45). In a comparison between cell counts and gamma-globulin contents, 19 (65.4%) out of 29 milks containing over 500,000 cells/ml had gamma-globulin less than 1.138 mg/ml, which was also seen in 97% of 172 milks having less than 500,000 cells/ml. From these results, it was suggested that the gamma-globulin content of milk might be of use for differentiating normal milk from abnormal ones.

Animals↗
PubMed1996

Long-term effects of inhaled anticholinergic drug on lung function, dyspnea, and exercise capacity in patients with chronic obstructive pulmonary disease.

To investigate the long-term effects of the inhaled anticholinergic bronchodilator, oxitropium bromide (OTB), on lung function, exercise capacity, and dyspnea in patients with chronic obstructive pulmonary disease (COPD), spirometry and symptom-limited exercise testing before and 1, 6, and 12 months after the regular use of OTB (600 micrograms/day) were performed in 12 patients with the use of OTB (mean age 69.9 +/- 3.1 years; FEV1/FVC 53.3 +/- 1.6%) as well as in 12 control patients who were not treated with OTB (Mean age 68.8 +/- 2.8 years; FEV1/FVC 52.6 +/- 1.9%). The dyspnea was evaluated by the slope of the regression line between Borg scale and oxygen uptake (Vo2) during exercise (Borg scale slope: BSS). At 1, 6, and 12 months after the start of OTB, the forced expiratory volume in one second (FEV1) and the exercise capacity (maximal Vo2) were greater than the pretreatment values and the dyspnea index (BSS) was significantly improved compared with the pretreatment value, while these parameters slightly worsened in the control patients over one year. In conclusion, the chronic use of an inhaled anticholinergic bronchodilator may provide beneficial improvements in expiratory flow rate, exercise performance, and dyspnea in mild to moderate COPD patients over one year.

Administration, Inhalation↗
PubMed1996

Near-death asthmatic reaction induced by disodium cromoglycate.

A near-death asthmatic reaction was induced by disodium cromoglycate (DSCG) as evidenced by positive skin and inhalation provocation tests. The patient's history revealed an episode of exacerbation by inhalation of DSCG. In spite of such an experience, he inhaled DSCG for relief of asthmatic attack, resulting in near-death exacerbation. This patient emphasizes the need to re-recognize that DSCG is not a reliever and the DSCG could cause fatal asthma.

Adult↗
PubMed1996

[Early phase II trial of Gd-BOPTA (E7155) for the MR imaging of liver tumors].

A clinical early phase II trial of Gd-BOPTA (E7155) was performed to assess its safety and usefulness for the detection of the hepatic lesions. Seventy-nine patients were assigned to three groups; a low dose group (0.025 mmol/kg), medium dose group (0.05 mmol/kg) and high dose group (0.1 mmol/kg). In terms of safety, Gd-BOPTA was assessed as "safe" in 76 patients and "somewhat questionable" in three patients including one with nausea and two with obvious changes in laboratory findings. No severe adverse reaction was experienced. In terms of the usefulness of dynamic study, the percentage of more than "useful" in the high dose group, medium dose group and low dose group were 100%, 100% and 76.9%, respectively. The result of "usefulness" of early and delayed post-contrast images showed more than "useful" in over 60% of cases. These results indicated that both dynamic and post-contrast early and delayed images were useful for the evaluation of liver tumors, suggesting that this contrast agent would have characteristics of both extracellular and liver-specific contrast agents.

Adolescent↗
PubMed1996

[Applicability of the dual interval echo train (DIET) method for female pelvic diseases].

Dual interval echo train fast SE (DIET-FSE) is a modified fast SE technique. It attenuates fat signals by applying a time interval between an excitation pulse and the first echo, which is the odd-number of the following echo interval, and by decreasing the number of high frequency refocusing pulses before collecting echoes in the center of the k space, which determines the contrast. Unlike many other fat-suppression methods, this technique is less affected by susceptibility effects. In this study, we compared DIET-FSE with FSE and conventional SE of the female pelvis. The results of DIET-FSE showed a stable, obvious fat suppression effect which resulted in the easy detection of pelvic organs such as the intestines and ovaries, as compared with FSE. The reductions in imaging time and motion artifacts also permitted more precise differentiation between the normal pelvic organs and lesions than conventional T2-weighted SE. These results imply that the DIET-FSE is useful for the diagnosis of female pelvic disorders.

Female↗
PubMed1995

Triggering of calcium signals in antigen-specific B-cells on the supported lipid monolayers.

Using supported lipid monolayers we have studied here calcium signals in antigen-specific B-cells (TNP-specific B-cell hybridomas, TP67.21) triggered by lipid hapten (TNP-Cap-DPPE). Stimulation of the B-cell hybridomas (TP67.21) with a supported DPPC monolayers containing 1% TNP-Cap-DPPE increased the intracellular free calcium ion concentration [Ca2+]i in B-cells. None of B-cells responded to a DPPC monolayers without lipid hapten (TNF-Cap-DPPE). Triggering for calcium signals was clearly dependent on the fluidity of the lipid monolayers. Solid DPPC and DSPC monolayers triggered the calcium signals more efficiently than the fluid DMPC monolayers did. These calcium signals became apparently more efficient in the presence of cholesterol. All of these results suggested that the rigidity of cross-linking for antigen receptors (mIgM) may be a crucial role for triggering calcium signals in B-cells.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1995

Analysis of the p53 gene in human choriocarcinoma cell lines.

In the present study, we analysed human choriocarcinoma cell lines for abnormalities in the tumour-suppressor gene p53 by Southern blotting, Northern blotting, non-radioisotopic single-stranded conformational polymorphism (SSCP) and complementary DNA sequencing. In all cell lines (Bewo, GCH-1, GCH-2, SCH, JAR, JEG-3, NUC-1 and HCCM-5), no p53 gene abnormality was detected by using Southern blotting. p53 mRNA of the expected size was detected in all cell lines tested by Northern blotting. SSCP analysis revealed abnormalities of p53 cDNA in the SCH cell line. Sequencing analysis of the entire coding region of the p53 gene revealed that both alleles were expressed in the JEG-3 cell line, and one of the alleles contained a point mutation (G to T) in codon 167 (Gln to His). In the NUC-1 cell line both alleles were point mutated. One allele had a point mutation (A to T) that resulted in a codon 17 change (Glu to Asp), and another had a point mutation (A to T) that caused a codon 24 change (Lys to Asn). In the SCH cell line, AGG was inserted between codon 249 and 250; this insertion resulted in an abnormal structure of the p53 protein. In three out of eight human choriocarcinoma cell lines, a p53 gene abnormality was detected. Therefore our data demonstrate that p53 gene abnormalities are associated with choriocarcinoma cell lines.

Base Sequence↗
PubMed1995

Blood flow velocity profiles in pulmonary branch arteries in lambs.

We studied the detailed profiles of blood flow in the right and left pulmonary arteries using 20 MHz pulsed Doppler ultrasound equipment in a lamb model. Fourteen lambs aged four to six weeks were selected. In six lambs, monocrotaline pyrrole was injected parenterally to create pulmonary hypertension (PH group). Eight other lambs served as unaltered controls (control group). The blood flow velocities were sampled in 1mm increments along the anterior-posterior axis of the branch arteries. The maximum velocity of the forward flow in the left pulmonary artery was higher than that in the right pulmonary artery in the control group (71.7 +/- 15.9 cm/s vs 60.2 +/- 13.5; p < 0.05). The fastest backward flow was located at the posterior position of the vessel in the right pulmonary artery in the control group (71.7 +/- 15.9 cm/s vs 60.2 +/- 13.5; p < 0.05). The fastest backward flow was located at the posterior position of the vessel in the right pulmonary artery in the control group. No significant bias in location was shown in the left pulmonary artery. Using indices of P90, acceleration time, P90*AcT, the velocity waveforms in the PH group were compared with those in the control group. In the left pulmonary artery, every index in the control group showed a significantly greater value that in the PH group. On the other hand, no significant differences were found between either group in the right pulmonary artery.

Animals↗
PubMed1995

Pruning of rat cortical taste neurons by an artificial neural network model.

1. Taste qualities are believed to be coded in the activity of ensembles of taste neurons. However, it is not clear whether all neurons are equally responsible for coding. To clarify the point, the relative contribution of each taste neuron to coding needs to be assessed. 2. We constructed simple three-layer neural networks with input units representing cortical taste neurons of the rat. The networks were trained by the back-propagation learning algorithm to classify the neural response patterns to the basic taste stimuli (sucrose, HCl, quinine hydrochloride, and NaCl). The networks had four output units representing the basic taste qualities, the values of which provide a measure for similarity of test stimuli (salts, tartaric acid, and umami substances) to the basic taste stimuli. 3. Trained networks discriminated the response patterns to the test stimuli in a plausible manner in light of previous physiological and psychological experiments. Profiles of output values of the networks paralleled those of across-neuron correlations with respect to the highest or second-highest values in the profiles. 4. We evaluated relative contributions of input units to the taste discrimination of the network by examining their significance Sj, which is defined as the sum of the absolute values of the connection weights from the jth input unit to the hidden layer. When the input units with weaker connection weights (e.g., 15 of 39 input units) were "pruned" from the trained network, the ability of the network to discriminate the basic taste qualities as well as other test stimuli was not greatly affected. On the other hand, the taste discrimination of the network progressively deteriorated much more rapidly with pruning of input units with stronger connection weights. 5. These results suggest that cortical taste neurons differentially contribute to the coding of taste qualities. The pruning technique may enable the evaluation of a given taste neuron in terms of its relative contribution to the coding, with Sj providing a quantitative measure for such evaluation.

Animals↗
PubMed1995

Application of curdlan to controlled drug delivery. II. In vitro and in vivo drug release studies of theophylline-containing curdlan tablets.

Tablets (300 mg) having two different surface areas were prepared from spray-dried particles of curdlan (100 mg)/theophylline(200 mg). Drug release from the tablets was studied in vitro and in vivo. The in vitro drug release from a tablet with a larger surface area (Tab L) was faster than that with a smaller one (Tab S). The water uptake of Tab L was larger than that of Tab S, probably due to the difference in the tablets' surface areas. However, the water uptake was not a rate-determining step for the drug release from curdlan tablets containing a large amount of theophylline. A straight line was obtained when release % was plotted vs. time. The slope of each curve was calculated as 0.59 for Tab L and 0.58 for Tab S. This indicates that the release mechanism is non-Fickian diffusion controlled. In addition, the curdlan tablets or theophylline powder were administered orally to 5 healthy volunteers, and saliva concentrations of theophylline were determined. Each saliva concentration was converted to plasma concentration using the saliva to plasma ratio of the drug in each subject. The AUC of Tab L was nearly the same as that of powder, while the AUC of Tab S was smaller than that of powder. The mean residence times (MRTs) of theophylline powder, Tab S and Tab L were 11.1 +/- 1.5, 25.4 +/- 6.3 and 17.1 +/- 1.5 h (N = 4-5, mean +/- S.D.), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Availability↗
PubMed1995

Application of curdlan to controlled drug delivery. III. Drug release from sustained release suppositories in vitro.

The use of curdlan, a natural beta-1,3-glucan, in the preparation of sustained release suppositories was studied in vitro. To prepare the suppositories, indomethacin, prednisolone or salbutamol sulfate was mixed with curdlan gel. Preparation conditions, including heating time and curdlan concentrations of 5 and 10%, had little effect on the drug release. The tonicity (hypotonic or isotonic) of the media for the suppository preparation and for in vitro drug release study also had little effect on drug release. However, the heating temperature during gel preparation, the drug amount in the suppository and the type of release media did affect drug release. It was found that drug release was sustained and diffusion-controlled in the three drugs. And finally, curdlan can be applicable for use in a sustained release suppository.

Albuterol↗
PubMed1995

[A case of pulmonary infiltration with eosinophilia (PIE) syndrome associated with syndrome of inappropriate secretion of ADH (SIADH) in the elderly patient].

A 76-year-old woman was admitted to our hospital because of productive cough, fever and anorexia in January 1995. She had suffered from bronchial asthma for 25 years. From 1983, exacerbation of PIE was recorded three times, on which occasions prednisolone and antibiotics were quite effective. On admission, marked leukocytosis (28,000/microliters) and eosinophilia (18,000/microliters) were found. However, plasma IgE level was normal, and specific antigen for eosinophilia was not detected by RAST or the skin allergic reaction test. Chest X-ray film and CT scan revealed extensive bilateral pulmonary infiltration. Increase in eosinophils (33%) was demonstrated in bronchoalveolar lavage. Furthermore, biopsy specimen of the affected lung revealed diffuse infiltration of eosinophils into alveolar septa. On the basis of these findings, the patient was diagnosed as chronic eosinophilic pneumonia (PIE syndrome). Hyponatremia (117 mEq/l) was persistent after the hydration with normal saline. Plasma ADH was not suppressed (2.29 pg/ml) in spite of hypoosmolality of plasma. Laboratory examination showed that renal, adrenal and thyroid function as well as plasma renin activity were normal. Taking these findings together, she was diagnosed as having SIADH. Treatment with prednisolone improved not only the PIE syndrome but also SIADH.

Aged↗
PubMed1995

[Nocturnal pulmonary hypertension in an elderly patient with sleep apnea syndrome].

We report a case of sleep apnea syndrome (SAS) with nocturnal pulmonary hypertension (NPH) in a 71-year-old man suffering from dyspnea during sleep. Severe snoring at night and daytime sleepiness were noticed before admission by his wife. Nocturnal oxygen desaturation (NOD) was documented with a pulse oximeter and severe sleep apnea syndrome was diagnosed on the basis of results of respiratory inductive plethysmography, an apnea index (AI) > 20, minimum SpO2 56%. NPH was diagnosed by Swan-Ganz catheter. The levels of NPH were severe. Elevation of systolic pulmonary arterial pressure (PAP) above 40 mmHg was observed 137 episodes at night. Both NPH and NOD were improved by 1 L/min of nasal oxygen therapy. A number of episodes of systolic PAP above 40 mmHg with oxygen therapy was 55 episodes. Peak mean PAP was 36 mmHg in room air vs 33 mmHg in oxygen therapy. Minimum SpO2 with oxygen therapy was improved to 69%. Total time of SpO2 < 90% at night was 153 minutes in room air vs 37 minutes in oxygen therapy. In this case, NPH and NOD due to severe SAS were remarkably improved by oxygen therapy.

Aged↗
PubMed1995

The use of zona-free aged unfertilized human oocytes as a predictor for successful subzonal insemination.

OBJECTIVE: To examine the reliability of the zona-free aged (1 day old) human unfertilized oocyte sperm penetration assay for assessing sperm fertilizing ability and to determine the predictive value of this assay for subsequent subzonal insemination (SUZI) outcomes. DESIGN: A total of 253 unfertilized oocytes from total fertilization failure patients and from good fertilization rate (> 70%) patients in standard IVF were inseminated with donors' spermatozoa, and penetration rates were compared in each group. Two hundred seventy-two unfertilized oocytes from total fertilization failure, poor fertilization (< 30%), and normal fertilization (> 30%) were inseminated with husbands' spermatozoa, and penetration rates were compared between the three groups. In 29 patients, the results of the zona-free assay performed in previous IVF were compared with the fertilization rates of subsequent SUZI. RESULTS: In the zona-free assay using donors' spermatozoa, there was no difference in penetration rates between the two groups (109/122, 89.3% versus 114/131, 87.0%). Penetration rates using partners' spermatozoa were positively correlated with fertilization rates in standard IVF (total fertilization failure 34/75, 45.3%; poor fertilization 56/77, 72.7%; normal fertilization 108/120, 90.0%). There was a significant difference in fertilization rates after SUZI between the patients with negative and positive penetration in zona-free assay (4/53, 7.5%, versus 54/174, 31.0%). CONCLUSION: The zona-free human oocyte assay may primarily reflect sperm fertilizing ability. This asssay also could be a reliable predictor for subsequent SUZI outcome.

Cellular Senescence↗
PubMed1995

[Radiology in the past, present and future].

To celebrate the year of centennial of X-ray discovery, we have to consider future development of radiology in 21st century. Since WC Röntgen discovered X-ray in 1895, the radiological science have been continuously expanded. Even reviewing the history of radiology in Japan, there have been several epoch-making masterpieces. We Japanese radiologists should be more proud of Japanese radiology. It is evident that radiology of the 21st century will develop more and more on the basis of computer technology. In clinical radiology, every procedure will become more rapid and non invasive, and imaging diagnoses cover not only morphology but also function of tissue and/or cell components. To foresee the future, it is essential to understand radiology in the past and the present. In this lecture, I have reviewed a history of radiology in Japan, clarified the problems at the present and emphasized the importance of computer skill. I would like to ask all of Japanese radiologists to march forward in the midstream of medical science in cooperation of Japanese society of Radiological Technology and Industries.

Forecasting↗