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Biomedical subjects

T Tomomasa

Publications and source records attributed to T Tomomasa.

At least 73 records · Page 4Linked to original sources
PubMed1990

Antroduodenal manometry in the evaluation of chronic functional gastrointestinal symptoms.

Intraluminal pressure in the gastric antrum and duodenum was studied in 44 children and adolescents referred for evaluation because of functional symptoms, including vomiting, abdominal distension, and abdominal pain. Manometric abnormalities were found in 39 patients (89%). Abnormalities during fasting included absence of the migrating motor complex; retrograde, phase 3-like episodes; increased frequency, decreased duration, and decreased amplitude of phase 3 episodes; tonic duodenal contractions; nonpropagated bursts of duodenal contractions; and consistently low-amplitude or absent contractions. Postprandial abnormalities included a phase 1-like pattern (postprandial hypomotility) and phase 3-like episodes (failure to induce a fed pattern). The presence or absence of the migrating motor complex was a predictor of disability. Parenteral alimentation was needed by only 4 of 28 patients with the migrating motor complex, but by 13 of 16 patients without the migrating motor complex (P less than .001). In 15 of 18 patients studied on consecutive days, oral cisapride was associated with increases in the number and amplitude of duodenal contractions after a complex-liquid meal (P less than .02). It is concluded that antroduodenal manometry is a useful technique that elucidates the underlying gastrointestinal motility disorder present in the majority of children and adolescents with severe functional symptoms.

Adolescent↗
PubMed1989

Development of calcium channels in gastric smooth muscle.

We used [3H]nitrendipine to characterize dihydropyridine sensitive calcium channels on cells isolated from neonatal (1 d) and weanling (11 wk) rabbit gastric fundic and antral smooth muscle. Incubating with and without nifedipine 20 microM, specific binding was 56 +/- 4% of total binding at 0.1 nM [3H]nitrendipine. Specific binding was saturable, reversible, achieved equilibrium by 10 min at 4 degrees C, and was linearly related to cell concentration. The affinity constant for [3H]nitrendipine was higher in weanling fundus (kd = 243 +/- 121 pM) versus antrum (kd = 771 +/- 190 pM), p less than 0.05. There were no age-related changes in affinity. In the antrum, the number of binding sites (Bmax) increased from 6,000 +/- 266/cell in neonates to 27,500 +/- 8,440/cell in weanlings (p less than 0.05). In the fundus Bmax was 7,750 +/- 2,100/cell in neonates, and there was no age-related change. To assess function, we compared isometric stress in full thickness muscle strips oriented to the circular layer. Bethanechol stimulated dose-dependent tonic contractions in the fundus and phasic contractions in the antrum. Maximal stress increased with age from 305 +/- 54 mN/cm2 to 1140 +/- 73 mN/cm2 (p less than 0.05) in the fundus and from 72 +/- 20 mN/cm2 to 154 +/- 30 mN/cm2 (p less than 0.05) in the antrum. Preincubation and incubation without calcium resulted in reversible inhibition of contraction at both ages. Nifedipine 10-microM inhibited 100% of bethanechol-stimulated contraction in the antrum, but only 25% in the fundus at both ages.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Developmental changes in agonist-mediated gastric smooth muscle contraction in the rabbit.

We studied smooth muscle strips from rabbit proximal stomach to explore the age-related changes in agonist-mediated contraction. Strips from neonatal (1 d) and weanling (11 wk) rabbits were oriented to measure isometric tension in circular muscle. Bethanechol stimulated maximal tension in both age groups. Although the potencies for bethanechol were similar (ED50 approximately 5 microM), the maximal response was nearly 4-fold greater in weanling (1140 +/- 73 mN/cm2) versus neonate (305 +/- 54 mN/cm2), p less than 0.001. Maximum stress increased with age for bethanechol, high extracellular K+, and substance P, but not for serotonin, cholecystokinin octapeptide, neurotensin, or bombesin. Only bombesin stimulated larger contraction in neonates (152 +/- 37 mN/cm2) versus weanlings (86 +/- 20 mN/cm2), p less than 0.05. Potencies did not change with age, except for substance P and serotonin. Substance P and serotonin induced early phasic and prolonged tonic contractions, which were unaffected by tetrodotoxin or atropine. ED50 for the phasic and tonic components of substance P-stimulated contraction in neonates were 1.8 and 7.7 nM. Substance P was 60-70 times more potent in neonates versus weanlings (p less than 0.001). ED50 for serotonin-stimulated contraction in neonates (33 and 22 nM, respectively) were 20-30 times more potent than in weanlings (p less than 0.05). Motilin, morphine, epidermal growth factor, and gastrin did not stimulate contraction at either age. We conclude that age-dependent changes in agonist potency and efficacy may be one factor to explain in part the changes that occur in gastric motility during postnatal development.

Animals↗
PubMed1988

Antroduodenal motility in children with chronic intestinal pseudo-obstruction.

Chronic intestinal pseudo-obstruction describes a heterogeneous group of disorders characterized by signs and symptoms of intestinal obstruction in the absence of a mechanical lesion. We studied antroduodenal motility in 13 children with pseudo-obstruction. The diagnosis was based on radiographic evidence in all, surgery in 11, and specific pathologic features in four. Antroduodenal motility was abnormal in all 13. Qualitative abnormalities in the patterns of antroduodenal contractions permitted separation into groups: (1) postprandial hypomotility (n = 3), (2) absent migrating motor complexes, with phase 3-like activity at the start of meals (neuropathic variety) (n = 5) (3) very low amplitude or absent contractions (myopathic variety) (n = 2); the remaining patients (n = 3) had other distinctive abnormalities. Cisapride, a new gastrointestinal prokinetic drug, stimulated proximal duodenal contractions in the 30 minutes after a meal in nine of 10 patients tested. These studies indicate that antroduodenal manometry is useful for characterizing intestinal pseudo-obstruction, and cisapride stimulates postprandial duodenal contractions in patients with pseudo-obstruction.

Child↗
PubMed1988

Development of the muscarinic receptor in rabbit gastric smooth muscle.

We used binding of [N-methyl-3H]scopolamine ( [3H]-NMS) to tissue homogenates and isometric contraction of muscle strips to characterize perinatal changes in the muscarinic receptor on rabbit gastric smooth muscle. In homogenates from fetal (28 days of gestation), 1-, 3-, and 7-day, 4- and 11-wk-old rabbits, specific binding was saturable and temperature dependent, achieved equilibrium by 10 min at 30 degrees C, and was linearly related to tissue concentration. Specific binding was 80 +/- 2% of total binding at 0.2 nM [3H]NMS. The number of binding sites was 120,000 receptors/cell, maximal during the first week of life compared with the fetus or older animals. Affinity of [3H]NMS was highest in the first week of life (Kd = 345 +/- 24 pM, 1 day old). Age did not affect Hill coefficients or Ki values; secoverine and 4-diphenylacetoxy-N-methylpiperidine methiodide were 50-fold more potent than pirenzepine. In muscle strips, bethanechol stimulated dose-dependent atropine-inhibitable isometric contraction. The doses required for half-maximal contraction were similar in both age groups (5-6 microM), but maximal contraction was fivefold greater in weanlings compared with neonates. Increasing extracellular potassium concentration resulted in similar differences, suggesting that the differences were not receptor related. These results suggest that well-differentiated M2-muscarinic receptors are functional on rabbit gastric smooth muscle during the perinatal period.

Animals↗
PubMed1987

[3H]QNB binding and contraction of rabbit colonic smooth muscle cells.

We used radioligand binding and studies of cell contraction to characterize muscarinic receptors on dispersed smooth muscle cells from rabbit proximal and distal colon. Cells obtained after serial incubations in collagenase were used to measure binding of tritiated quinuclidinyl benzilate [( 3H]QNB). AT 37 degrees C, specific [3H]QNB binding was saturable and linearly related to cell number. Nonlinear regression analysis was used to determine the affinity of [3H]QNB for its receptor. In the distal colon the Kd was 60 pM, and the mean number of receptors was 1.2 X 10(6)/cell. Compared with cells from the distal colon, cells from the proximal colon had a lower affinity (Kd = 337 pM) but similar numbers of receptors. The concentrations of the antagonists atropine, secovorine, and pirenzepine, which were required for inhibition of 50% [3H]QNB binding (IC50), were 8, 5, and 870 nM, respectively, suggesting that the receptors are of the M2-muscarinic subclass. Hill coefficients for these agents were 1.1, 0.9, and 1.1, suggesting binding to a single receptor. The IC50 for the muscarinic agonists bethanechol and oxotremorine were 80 and 0.57 microM, respectively. Hill coefficients were 0.67 for both, suggesting more complex interactions involving receptors of different affinities. In studies of cell contraction, bethanechol stimulated a dose-dependent decrease in cell length with half the maximal contraction occurring at 100 pM. These results suggest that 1) contraction is mediated by binding of bethanechol to M2-muscarinic receptors and that 2) there are a large number of spare receptors in colonic smooth muscle.

Animals↗
PubMed1987

Gastroduodenal motility in neonates: response to human milk compared with cow's milk formula.

It is known that breast milk empties more quickly from the stomach than does infant formula. We studied the difference in gastroduodenal motility between neonates fed with human milk and those fed with infant formula. Twenty-four five- to 36-day-old neonates were fed with mother's breast milk or with a cow's milk-based formula. Postprandial gastroduodenal contractions were recorded manometrically for three hours. Repetitive, high-amplitude nonmigrating contractions were the dominant wave form during the postprandial period. The number of episodes, duration, amplitude, and frequency of nonmigrating contractions were not different following the different feedings. The migrating myoelectric complex, which signals a return to the interdigestive (fasting) state, appeared in 75% of breast milk-fed infants but only 17% of formula-fed infants (P less than .05) within the three-hour recording period. Because contractions were similar following the two meals, but a fasting state recurred more rapidly in breast-fed infants, we conclude that factors other than phasic, nonpropagated antroduodenal contractions were responsible for the differences in gastric emptying between breast milk and formula.

Adult↗
PubMed1986

Erythromycin induces migrating motor complex in human gastrointestinal tract.

Fifteen healthy subjects, fasted at least 8 hr, were studied by means of an infused manometric method. Twenty minutes after termination of the natural phase III activity in the duodenum, erythromycin or normal saline was administered intravenously for 15 min. When normal saline (N = 5) was infused, the next migrating motor complex (MMC) was initiated 151.2 +/- 42.1 min after the infusion. On the other hand, when erythromycin was infused at a rate of 1.0 mg/kg/hr (N = 5) or 3.0 mg/kg/hr (N = 5), MMC-like contractions were initiated at shorter intervals, ie, 47.8 +/- 40.9 min (P less than 0.005) or 23.0 +/- 13.0 min (P less than 0.001) respectively. The duration, frequency, amplitude, and migrating velocity of the naturally occurring MMC (N-MMC) were not significantly different from those of the erythromycin-induced contractions except for the duration of the phase III contractions in the stomach; the duration (5.3 +/- 2.2 min) of the erythromycin-induced contractions being significantly (P less than 0.05) longer than that (3.2 +/- 0.9 min) of the naturally occurring MMC. The immunoreactive motilin (IRM) concentration did not increase significantly after the infusion of erythromycin, when compared to that after infusion of normal saline. It is concluded that erythromycin at a dose of 1-3 mg/kg/hr for 15 min during the interdigestive state, similar to motilin, has a significant influence upon the initiation of MMC in the human gastrointestinal tract, but further investigations are required to confirm whether endogenous motilin is involved or not.

Adult↗
PubMed1986

A case of virus-associated haemophagocytic syndrome with hypoplastic anaemia.

A 4-year-old girl with virus-associated haemophagocytic syndrome is described, suffering from fever, jaundice, rectal bleeding and a loss of consciousness. Severe pancytopenia was a prominent finding. The bone marrow biopsy showed hypocellularity, and bone marrow aspiration revealed proliferation of histiocytes containing many erythrocytes and thrombocytes. The patient recovered within several weeks of supportive therapy. Viral studies demonstrated a recent infection with Epstein-Barr virus.

Anemia, Aplastic↗
PubMed1985

Manometric study on the intestinal motility in a case of megacystis-microcolon-intestinal hypoperistalsis syndrome.

We report on the intestinal motility in a case of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) based on a total registered time of 9.5 h by means of a manometric method we recently developed for neonates. The characteristics of this case are as follows: (a) the frequency of the contractions in the stomach and duodenum was significantly lower than that of healthy infants; and (b) bands of rhythmic contractions, resembling phase III activity of the interdigestive migrating contractions in adults, were recorded in the duodenum, but their occurrence was less frequent and the amplitude was significantly lower than that of healthy infants. The present study indicates that "hypoperistalsis" in MMIHS means not only the low frequency, but also the low amplitude, of the contractions in the alimentary tract.

Colon↗
PubMed1985

Nonmigrating rhythmic activity in the stomach and duodenum of neonates.

We studied gastrointestinal motility in 20 infants, using a modified manometric method for neonates, and compared it to that in adults. Changes in the intragastric and intraduodenal pressures were recorded for 3 h after the ingestion of milk. Bands of contractions with the same rhythmicity as phase III activity in adults were frequently recorded. Some of them migrated caudally and were speculated to the equivalent of phase III activity of the interdigestive migrating complex (IMC) in adults. However, others did not migrate and showed some differences from phase III activity of adults and infants in the time of occurrence, duration and amplitude. The characteristic of gastroduodenal motility in infants was the frequent occurrence of these bands of nonmigrating rhythmic concentrations. Our findings indicated the following problems: (1) there are some differences in gastrointestinal motility between infants and adults and further investigations are required for the evaluation of the physiology or pathophysiology of this phenomenon; (2) in infants, many bands of rhythmic contractions of the alimentary tracts can exist without migration. This indicates the possibility that the occurrence of rhythmic contractions and their migration are regulated by different mechanisms.

Adult↗
PubMed1985

The evaluation of gastroesophageal reflux symptoms in patients with bronchial asthma.

Lower esophageal sphincter pressure (LESP) and extended pH monitoring of the distal esophagus were assessed in 15 asthmatic children in order to evaluate the most important symptoms of suspected gastroesophageal reflux (GER)-asthma. As a result, episodes of asthmatic attacks after overeating were closely correlated with GER as determined by decreased LESP and high pH score.

Adolescent↗
PubMedDate not supplied

Measurement of tricuspid annular diastolic velocities by Doppler tissue imaging to assess right ventricular function in patients with congenital heart disease.

We assessed the clinical utility of using diastolic tricuspid annular velocities obtained by Doppler tissue imaging as a noninvasive index of right ventricular function in patients with congenital heart disease. Doppler tissue imaging at the tricuspid annulus and pulsed Doppler echocardiography of the right ventricular inflow were performed in 71 children with congenital heart disease, with and without elevated right ventricular pressure. Cardiac catheterization was performed in all patients with congenital heart disease, and the hemodynamic determinants of the tricuspid annular and inflow velocities were determined. In patients with congenital heart disease, the ratio of the late-to-early diastolic tricuspid annular velocity (Aa/Ea) showed a highly significant correlation with right ventricle pressure/left ventricle pressure (r = 0.79, p < 0.0001), right ventricular end diastolic pressure (r = 0.46, p < 0.0001), and the first derivatives of the change in right ventricle pressure during diastole (r = 0.72, p < 0.0001). However, the late-to-early diastolic tricuspid inflow velocity (A/E) did not correlate with any invasively measured index of right ventricular function. Aa/Ea, derived from tricuspid annular velocities as measured by Doppler tissue imaging, is a valuable, noninvasive tool for detecting an elevated right ventricular pressure in patients with congenital heart disease.

Blood Flow Velocity↗
PubMedDate not supplied

Doppler echocardiographic evaluation of right ventricular diastolic function in children.

Right ventricular diastolic function was evaluated by flow velocity pattern in the right ventricular inflow tract by means of pulsed Doppler echocardiography. Traditionally used to evaluate this function are peak velocities obtained during early diastole (peak E wave) and during atrial contraction (peak A wave), their ratio (peak E/A ratio), and the deceleration half-time. We conducted pulsed Doppler echocardiographic studies of right ventricular inflow and outflow patterns in 171 children (105 normal children and 66 children who were undergoing total surgical repair of congenital heart defects without sequelae). Results showed that summation flow was present in the right ventricular inflow tract in 43 (25%) of the 171 subjects, which made it difficult to separate the peak E wave from the peak A wave. We noted the presence of antegrade late diastolic flow (DW) in the right ventricular outflow tract of all subjects. DW, measured in 121 subjects in whom both E and A waves were detected in the right ventricular inflow tract, showed a highly significant correlation (p < 0.0001) with A waves in the right ventricular inflow tract. The ratio of DW to right ventricular outflow tract velocities during systole (SW) showed a highly significant (p < 0.0001) correlation with E/A ratio. When evaluating right ventricular diastolic function by pulsed Doppler, especially in children, the analysis of right ventricular outflow tract patterns is helpful in addition to that of inflow tract patterns. The DW and DW/SW ratio may present good alternatives to traditional parameters in children.

Blood Flow Velocity↗
PubMedDate not supplied

Macro creatine kinase in Kawasaki disease.

This report describes a case of Kawasaki disease with macro creatine kinase (CK). A 13-month-old boy developed typical symptoms of Kawasaki disease and was treated with flurbiprofen, dipyridamole, and intravenous gamma-globulin. The serum level of CK increased during treatment from 371 U/L, at 4 days after the onset of Kawasaki disease, to 13,222 U/L 3 days later. Immunofixation electrophoresis identified macro CK as containing immunoglobulin A (kappa, lambda). The presence of macro CK may result from muscle tissue involvement in Kawasaki disease.

Biomarkers↗
PubMedDate not supplied

Statistical analysis of symptoms and signs in pediatric patients with peptic ulcer.

It is not well known which symptoms or signs related to peptic ulcer are crucial for its diagnosis in children. In order to clarify this problem, we evaluated the sensitivity, specificity, and positive and negative predictability of 13 ulcer-related symptoms and signs. The data of 160 patients, who were suspected of having peptic ulcer and had undergone endoscopic examinations, were studied. It was significant that five symptoms, i.e., presence of pain in the epigastrium, relationship between the time of pain and that of eating, family history, vomiting, and bleeding, were frequently found in ulcer patients. There was, however, no symptom or sign that predicted by itself precisely the existence of a peptic ulcer. Thus, we computed a discriminant function by combining the data by multivariate analysis. With this score, we could predict the existence of ulcer more precisely. Finally, it was concluded that epigastric pain, food-related pain, vomiting, bleeding, and family history were crucial factors for the diagnosis of peptic ulcer in childhood and that an overall consideration of symptoms and signs was needed for the evaluation of these factors.

Adolescent↗
PubMedDate not supplied

Endoscopic findings in pediatric patients with Henoch-Schonlein purpura and gastrointestinal symptoms.

We report the gastrointestinal endoscopic findings in nine patients with Henoch-Schonlein purpura. Eight patients underwent upper gastrointestinal endoscopy, which revealed erosive gastritis in one patient, hemorrhagic-erosive duodenitis in four, and both findings in one. The rectum and the sigmoid colon were examined in six patients. Aphthoid ulcers were noted in two. In one of these patients, a rectal ulcer was also noted. Severe inflammatory changes and angiitis were found in the biopsy specimens obtained from the duodenum and the colon. The vascular abnormalities in the gastrointestinal mucosa are similar histologically to those found in the skin in Henoch-Schonlein purpura.

Adolescent↗