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Biomedical subjects

N Umeda

Publications and source records attributed to N Umeda.

At least 55 records · Page 3Linked to original sources
PubMed1989

Effect of the luminal hydrogen ion on alkali and mucus secretion in the rat stomach.

This study was designed to investigate the effect of luminal H+ on alkali and mucus secretion in the isolated rat stomach. At various luminal pHs, the thickness and the pH gradient of the mucus gel layer were measured. The maximum pH and calculated alkali secretion showed that the latter was stimulated in parallel with an increase in luminal H+ concentration, especially when the luminal pH became less than 3.5. Mucus secretion, however, was not significantly affected by the luminal H+ concentration. These results suggest that alkali and mucus secretion in the stomach are not regulated by the same mechanism, but different ones.

Alkalies↗
PubMed1989

Role of the mucus gel layer in the healing of acetic acid-induced gastric ulcers in rats.

Changes in the pH gradient and thickness of the mucus gel layer in the healing of acetic acid-induced gastric ulcers in rats were investigated. The maximum of the pH gradient and the thickness of mucus gel layer at the edge of ulcers and in the regenerated mucosa were higher, decreased gradually with the healing of the ulcers and finally reached normal values. This indicates that mucus and bicarbonate are secreted actively from the mucosa surrounding an ulcer and that they play an important role in protection of the base of ulcers and in acceleration of the healing of the ulcers.

Acetates↗
PubMed1988

Plasma famotidine concentration versus intragastric pH in patients with upper gastrointestinal bleeding and in healthy subjects.

To study the concentration-response relationship of famotidine, we serially monitored intragastric pH and measured plasma drug concentrations simultaneously after an intravenous injection of this H2-receptor antagonist (0.1 mg/kg) in eight patients with upper gastrointestinal bleeding and in six healthy subjects. By applying the sigmoidal Emax model the mean (+/- SD) plasma famotidine concentrations associated with an intragastric pH of 4.0 in patients and healthy subjects were estimated to be 17.7 +/- 10.7 and 24.8 +/- 10.3 ng/ml, respectively (not significantly different). No significant differences were observed in the mean pharmacokinetic parameters between the two study groups. Multiple regression analysis revealed that not only a pharmacokinetic factor (i.e., elimination t1/2) but also a pharmacodynamic (or sensitivity) factor (i.e., a drug concentration associated with an intragastric pH of 4.0) contributed significantly (p less than 0.01) to the overall variability in the duration of antisecretory effect in our study subjects, with standardized partial regression coefficients of 0.54 and -0.63, respectively. Based on these data, we predict that around-the-clock control of a fasting intragastric pH above 4.0 can be attained by a continuous infusion of famotidine at rates ranging from 6 to 25 mg/day (mean +/- SD, 11 +/- 7 mg/day) in a 70 kg patient whose pharmacokinetic and pharmacodynamic characteristics are similar to those of our patients.

Adult↗
PubMed1988

Scanning electron microscopic study of the capillary loops in the dermal papillae. Skin of the hand of the Japanese monkey (Macaca fuscata).

The microvasculature of the skin of the hand of Japanese monkeys was examined by means of scanning electron microscopy of corrosion casts. The vasculature of all areas of the skin of the hand was examined and divided into three structures excluding the nail bed: (1) In the ball of the finger, the typical structure of the capillary loops was studied. Capillary loops were formed out of not just one capillary vessel, but two or three vessels. Each capillary vessel arose and divided into several branches at the papilla, and they became descending limbs. After the loop passed a hairpin turn, the descending limbs were 1.5 times larger than the ascending limbs in the intrapapillary portion, and they became extrapapillary venules. The descending limbs connected with the postcapillary venules in the postpapillary portion and with the horizontal network. The postcapillary venules fused with each other (1-5 loops) to form the primary and secondary venous arcades. (2) In the thenar eminence, the capillary loops were a little lower, and their grooves were wider than in the ball of the finger. The characteristic structure in this area was the interpapillar capillary network. (3) In the lateral side of the finger, the number of capillary loops formed by the arterial capillary network of the subepidermal layer was smaller. The capillary loops here had the lowest height and a simple structure.

Animals↗
PubMed1987

Altered protein binding of disopyramide in plasma from patients with cancer and with inflammatory disease.

Protein binding of disopyramide (D) was studied in eight patients with cancer, seven with inflammatory diseases, and seven healthy subjects. Plasma samples containing concentrations of 0.2-12.0 micrograms/ml were ultrafiltered, and the free fractions were measured with fluorescence polarization immunoassay. The mean free fractions at D concentrations ranging from 1.0 to 6.0 micrograms/ml were significantly less in patients with cancer (p less than 0.01) and those with inflammatory diseases (p less than 0.05) than in healthy subjects. Patients with cancer had a greater (p less than 0.05) D binding than those with inflammatory diseases. A multiple regression analysis revealed a significant contribution of plasma alpha 1-acid glycoprotein (AAG) (r = -0.79, p less than 0.01), but not of albumin (r = -0.096), to the overall variability in D binding at 3.0 micrograms/ml. The mean capacity constant in the two patient groups was similar, but significantly (p less than 0.01) greater than in the healthy group. Nonspecific D binding was greater in cancer patients (p less than 0.01) compared to the other two groups. Our results suggest that (a) therapeutic range of D measured as total drug concentration in patients with cancer and with inflammatory diseases would be greater than previously thought, and (b) unidentified component(s) (other than AAG and albumin) might contribute to the greater D binding in cancer patients compared to other study groups.

Adult↗
PubMed1986

Protein binding of disopyramide in liver cirrhosis and in nephrotic syndrome.

The plasma protein binding of disopyramide (D) was determined in seven patients with cirrhosis, six with nephrotic syndrome, and seven healthy subjects. Plasma samples containing concentrations of 0.2 to 12.0 micrograms/ml were ultrafiltered and the free fractions were measured with fluorescence polarization immunoassay. The mean free fractions at D concentrations ranging from 1 to 6 micrograms/ml were significantly (P less than 0.01) greater in patients with cirrhosis than in healthy subjects. No difference was observed between patients with nephrotic syndrome and healthy subjects. The free fraction at D 3 micrograms/ml correlated better with alpha 1-acid glycoprotein (r = -0.77) than with albumin (r = -0.46). Patients with cirrhosis had significantly (P less than 0.01) lower capacity constants as compared with the other two study groups. There was a significant (P less than 0.01) correlation between capacity constant and alpha 1-acid glycoprotein (r = 0.71). Our results suggest that the D therapeutic range measured as the total plasma concentration in cirrhosis, but not in nephrosis, should be approximately 50% lower than previously believed.

Adult↗
PubMed1980

Some notes on reading: talkers, material and reading rate.

The paper describes a method of estimating a person's reading rate from a small sample of his speech (in other words, a short sentence). Reading rate was obtained by measuring the speaking portion of a considerable amount of reading, and dividing it by the number of phonemes in the material (this is called the grand mean). Out of 108 sentences read by four talkers, 58 having 15 words or less were selected. The ratio of unstressed to stressed syllables, and the number of syllables per occurrence of terminal lengthening were calculated for each of the 58 sentences. Sentences with both of these values in the middle range were considered to have an average phoneme duration close to the grand mean. The prediction was compared to actual readings by four talkers, with 83 percent agreement. The Summary section contains instructions for applying our method of estimating a person's reading rate. Those who are interested should read the Summary section and the Appendix first.

Female↗
PubMed1979

Endoscopic analysis on the growth of early gastric carcinoma.

Earliest endoscopic appearance and its subsequent changes were studied in 41 cases of early gastric carcinoma where gastrocamera photographs were available for detailed analysis over the period from three months up to 10 years. The earliest appearance of polypoid carcinoma was a small area of nodularity, and that of carcinoma with mucosal depression was patchy reddening. Both types of carcinoma were thought to occur initially as a lesion without mucosal elevation or depression (IIb). In carcinoma with shallow mucosal depression (IIc and IIc-+III), there were cases believed to have remained intramucosal for an extremely long period of several years, whereas, in polypoid carcinoma (IIa and I), the growth seemed to be more rapid. In the cases with ulcer within the carcinomatous lesion, healing of the ulcer was confirmed in 37%, and "malignant cycles" were observed in 21%. Malignant transformation of gastric ulcer was suggested in one case with linear ulcer.

Adult↗
PubMed1978

Occurrence of glottal stops in fluent speech.

The use of glottal stops in continuous speech in American English has not been well studied, in spite of the common belief that they may serve as boundary markers. This paper reports the result from measurements of five speakers' readings of four stories, each arranged in both list and story form. Data were analyzed according to the difference in speakers, materials, versions, phonological situations (phoneme sequence and stress situations), grammatical conditions, and frequency of occurrence of words. Results show that higher-level factors such as speaker's reading style and difficulty of material have a strong influence than phonological and grammatical factors.

Acoustics↗
PubMed1977

Outcome of gastric carcinoma detected by gastric mass survey in Japan.

The outcome was studied of gastric carcinoma found in six selected mass survey groups. One-hundred-and-thirty-seven cases of gastric carcinoma were detected and followed-up postoperatively for 16 years at the longest. They consisted of 55 cases of early and 74 of advanced carcinoma with eight cases of unknown depth of involvement. Early carcinoma amounted to 42-6% of the cases with known depth of involvement. The relative five-year and 10-year survival rates calculated by the method of Ederer et al. (1961) in the 137 cases were 0-628 and 0-642, respectively, and those for early carcinoma were 0-959 and 1-016. These survival rates are remarkably high. The five-year survival rate in those who were followed-up after operation for more than five years (83 cases) was 0-554, which is much higher than that of the outpatient cases, who presented themselves for medical advice with some symptoms. The good prognosis is largely explained by a high incidence of early gastric carcinoma in the cases detected in the mass survey. Where methods of screening were concerned, the use of the gastrocamera markedly improved the detection rate of gastric carcinoma.

Adult↗
PubMed1977

Influence of aspirin on healing of chronic gastric ulcers in dogs.

Gastric ulcers induced in dogs by transserosal injection of 1 ml of 40% acetic acid healed completely by the 7th week after ulceration and never reulcerated during the observation period up to 12 weeks. Acetic acid ulcers in the active (at 1 week), quiescent (3 weeks) or healed (at 7 weeks) stages were not influenced by the daily administration of aspirin 2 g/dog/day for for 5 consecutive weeks. All examinations were done by gastroscopy in addition to macroscopical and histological observations at autopsy.

Acetates↗