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Biomedical subjects

K Momma

Publications and source records attributed to K Momma.

At least 91 records · Page 5Linked to original sources
PubMed1996

Inhibition of outflow cushion mesenchyme formation in retinoic acid-induced complete transposition of the great arteries.

OBJECTIVE: Endocardial cushion tissue formation, the primordia of valves and septa, is a critical event in cardiac morphogenesis. Maternally administrated all-trans retinoic acid is known to induce complete transposition of the great arteries (TGA) in the mouse embryo. To address the mechanisms of TGA, the effect of retinoic acid on cushion tissue formation was examined. METHODS: Using a three-dimensional collagen gel culture model, we performed various types of endothelial-mesenchymal transformation assays of co-cultured endocardium with myocardium obtained from 9.5-day mouse embryonic hearts. In vivo immunohistochemical detections of extracellular matrices, fibronectin and type I collagen, were also performed. RESULTS: Endothelial-to-mesenchymal transformation at the onset of cushion tissue formation was suppressed in the outflow tract of embryos exposed to retinoic acid in culture. This inhibitory effect of retinoic acid was spatially restricted to the outflow tract and reversed by treatment with embryonic myocardial conditioned medium enriched in extracellular inductive molecules. Mesenchyme formation in the outflow tract was inhibited at a lower concentration of retinoic acid (10(-10) mol/l) than that which inhibited the atrio-ventricular canal (10(-7) mol/l) in culture. The fibronectin and type I collagen depositions in pre-migratory outflow tract cardiac jelly in retinoic acid-treated embryonic heart were reduced compared to those in the control. CONCLUSIONS: Exogenously applied retinoic acid inhibits outflow tract cushion mesenchyme formation in the embryonic heart with TGA. It is suggested that retinoic acid inhibits the expression of extracellular matrices and inductive molecules synthesized by myocardium in the outflow tract.

Animals↗
PubMed1996

Expression of four myosin heavy chain genes in developing blood vessels and other smooth muscle organs in rabbits.

At least two smooth muscle myosin heavy chain (MHC) isoforms (SM1, SM2) and two non-muscle MHC isoforms (NMA, NMB) have been detected in smooth muscles. We used the S-1 nuclease mapping procedure to study the expression of these four types of MHC mRNAs in various rabbit blood vessels, such as the aorta (Ao), pulmonary artery (PA), inferior vena cava (IVC) and ductus arteriosus (DA), and in various rabbit tissues and organs. The results demonstrated that in the blood vessels, the four types of MHC mRNA were expressed during all developmental stages in Ao and PA and that SM2 expression appeared to increase dramatically after birth. Compared to the other fetal vessels, the fetal DA contained considerably higher amounts of the four types of MHC mRNAs. SM2 was more prevalent than SM1 in the esophagus, stomach, small intestine and urinary bladder, which are often stretched and show vigorous contractile activity. SM2 expression in a smooth muscle cell appears to correlate well with the contractile ability and/or activity of the cell. Our data show that among the four types of MHC mRNAs, the expression of SM2 MHC mRNA shows great variation among different organs, blood vessel types and stages of development of Ao and PA.

Amino Acid Sequence↗
PubMed1996

[Early esophageal cancer--concept, diagnosis and treatment].

In spite of the conventional definition of early esophageal cancer which includes mucosal and submucosal cancers without lymph node metastasis, esophageal mucosal cancers are now considered as the early cancer in clinical field. The esophageal mucosal cancers are subclassified into m1 (intraepithelial cancer), m2(lamina propria mucosae) and m3(muscularis mucosae) in clinical view points. M1 and m2 esophageal cancers which had no lymph node metastasis could be treated completely by endoscopic mucosal resection. On the other hand, the patients with m3 cancer which showed lymph node metastasis in 10% of the cases should be treated by esophagectomy with lymph node dissection. For the diagnosis of the depth of carcinoma invasion, now, endoscopy with dye iodine stain and toluisine blue stain were most useful. Fundamentally, macroscopic appearance of lesions classified by Japanese Society for Esophageal Diseases are well related to the depth of invasion. Almost all mucosal cancers showed the superficial and flat type (0-IIc type). Subclassification of m1, m2 and m3 were easily differentiated by endoscopic observation of their characteristic appearances. In the evaluation of the methods of treatment for mucosal cancer, endoscopic mucosal resection and esopagostomy showed a complete resectability. While, the former was superior in the quality of life after treatment.

Esophageal Neoplasms↗
PubMed1996

[Common atrium].

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed1995

Left ventricular dysfunction on exercise long-term after total repair of tetralogy of Fallot.

BACKGROUND: Excellent results regarding mortality are well recognized in the long-term period after intracardiac repair of tetralogy of Fallot. However, it is still unclear how postoperative sequelae affect cardiac performance during exercise. METHODS AND RESULTS: Twenty-nine patients with tetralogy of Fallot were studied 16 +/- 2 years after intracardiac repair by use of radionuclide first-pass ventriculography with an ultra-high-sensitive gamma camera at rest and at peak exercise on a semi-upright bicycle ergometer. The results were compared with those from 10 age- and sex-matched control subjects. Left and right ventricular ejection fraction and absolute ventricular volume were measured at rest and peak exercise. Regional right ventricular wall motion and diastolic function of the left ventricle were also assessed. Cardiac output of tetralogy was normally preserved both at rest and during exercise. Nevertheless, the incremental response of left ventricular ejection fraction during exercise was depressed in the patients. Left ventricular ejection fraction during exercise was inversely correlated with the right ventricular end-diastolic volume and the severity of pulmonary regurgitation. Regional wall motion at the right ventricular outflow tract was not decreased in the patients. Left ventricular diastolic function was not impaired in the patients compared with control subjects. CONCLUSIONS: Latent left ventricular dysfunction during exercise is related to an enlarged right ventricle due to pulmonary regurgitation after intracardiac repair of tetralogy. Careful follow-up is required in patients having significant pulmonary regurgitation.

Adult↗
PubMed1995

Morphological observations on the pathogenetic process of transposition of the great arteries induced by retinoic acid in mice.

BACKGROUND: The pathogenesis of complete transposition of the great arteries (TGA) is still controversial because useful animal models have not been established. We previously reported that all-trans retinoic acid induced complete TGA at a high proportion in mice. The aim of the present study was to clarify the morphogenesis of the cardiac outflow tract in the retinoic acid-treated embryos destined to develop TGA. METHODS AND RESULTS: We first examined the morphology of TGA in mouse fetuses treated with retinoic acid to establish an animal model of TGA (experiment 1) and then examined the retinoic acid-treated embryonic hearts by means of ink injection and histology (experiment 2). All mouse fetuses and embryos showed visceroatrial situs solitus and d-ventricular loop. In experiment 1, among 45 embryos treated with retinoic acid 70 mg/kg at day 8.5 of gestation, 35 (78%) had TGA and 3 (6.7%) had a double-outlet right ventricle with a subpulmonary ventricular septal defect. In experiment 2, all hearts already exhibited d-loop at gestation day 8.5. At gestation day 9.5, conus swellings, composed of acellular cardiac jelly, where hypoplastic, and the conotruncal cavity was nonspiral or tubular. At gestation day 11.0, aberrant conus swellings located anteroposteriorly to give a straight orientation to the conotruncal cavity. At gestation day 12.0, side-by-side great arteries were transposed in that the aorta arose from the right ventricle and the pulmonary artery arose above the interventricular foramen. CONCLUSIONS: These results suggest that a reproducible animal model of TGA can be produced in mice by treatment with retinoic acid; that there was no loop anomaly, such as an A-loop or L-loop, in our model; and that hypoplasia of the conus swellings appears to be the primary event leading to TGA.

Animals↗
PubMed1995

Coronary artery-pulmonary artery fistula in pulmonary atresia with ventricular septal defect.

This paper reports two patients presenting a combination of coronary artery-pulmonary artery fistula and pulmonary atresia with ventricular septal defect. A confluent central pulmonary artery arose from the proximal portion of the left coronary artery in both patients. The fistulous segment between the coronary artery and the central pulmonary artery was large, and no coronary arterial stenosis was found in either patient. Besides this fistulous origin of the pulmonary blood supply, large collateral vessels originated from the descending aorta in both patients. Neither patient has shown findings of myocardial ischemia, at least in consecutive rest and exercise electrocardiograms. Both patients were successfully operated, at the ages of 3 and 8 years, respectively. The clinical and embryological implications of this rare malformation are briefly reviewed.

Arteriovenous Fistula↗
PubMed1995

An endoscopic study on relationship between Helicobacter pylori infection and endoscopic gastric ulcer scars.

A two-year endoscopic follow-up study of 45 gastric ulcer patients was conducted in order to ascertain the relationship between Helicobacter pylori infection, the transformation of ulcer scar patterns, and ulcer relapse during maintenance therapy. Endoscopic findings of gastric ulcer scar patterns, which established the quality of ulcer scars, were classified as follows: Sa, with a central depression, Sb, with a coarse regenerating mucosal pattern up to the center, and Sc, with a fine pattern. The proportion of ulcer relapses was 62% among 29 H. pylori-positive patients and 0% among 16 H. pylori-negative patients. In regard to the relationship between H. pylori infection and scar patterns, 94% of the H. pylori-negative patients displayed Sc scar patterns, while all the H. pylori-positive patients showed various scar patterns, ie, Sa in 38%, Sb in 28%, and Sc in 10%. Ulcer relapses in the H. pylori-positive cases were limited to the Sa and Sb groups (100% and 88%, respectively). In conclusion, our results indicate that H. pylori infection plays an important role in the transformation of the ulcer scar patterns which relate to ulcer relapse.

Cicatrix↗
PubMed1995

Long-term results after surgical repair of total anomalous pulmonary venous connection--hemodynamic evaluation of pulmonary venous obstruction with isoproterenol infusion.

To evaluate late pulmonary venous obstruction following surgical repair in patients with total anomalous pulmonary venous connection, which may be disclosed at high cardiac output but not at rest, a hemodynamic study was performed using isoproterenol infusion. The study included 7 patients in NYHA class I, aged from 5 to 12 years (mean 6 years), who had undergone surgical correction in their early infancy (mean 79 days). After a routine catheterization protocol, isoproterenol was infused at a rate of 0.01 microgram/kg per min. On average, cardiac index increased from 4.8 to 8.1 L/min per m2. The pulmonary arterial and wedge pressures following isoproterenol infusion remained normal in all patients, including 1 case with mild pulmonary hypertension. These results suggest that most, if not all, patients with total anomalous pulmonary venous connection repaired in early infancy do not have any hemodynamic impairment if they show no pulmonary venous obstruction within the first 12 months following surgical correction.

Child↗
PubMed1995

Molecular characterization of a novel atrial-specific myosin heavy-chain gene expressed in the chick embryo.

A 1.2 kb fragment of a myosin heavy-chain (MHC) gene was isolated from the complementary DNA (cDNA) library derived from embryonic day 15 (E15), Hamburger and Hamilton (H.H) stage 41 chick embryonic ventricle, using a fragment of human beta-cardiac MHC cDNA as a probe. DNA sequence analysis determined that the gene (CCSV2) encoded the amino acid sequence of the rod portion (part of S2 and light meromyosin) of the chick atrial-specific MHC gene. The nucleotide sequence of CCSV2 was slightly different (90% homologous) from a previously reported atrial-specific MHC (AMHC1) expressed in chick embryo. Northern blot analysis, with the CCSV2 fragment (1.2 kb) used as a probe, showed that the gene is expressed intensively in the developing chick atrial muscle, but weakly in the ventricle and pectoralis muscle. S1-nuclease mapping analysis, with CCSV2 used as a probe, demonstrated a fully protected fragment in the atrium and ventricle. In this study, no intensive signal of a partially protected fragment was detected in the atrium. On the other hand, not only a fully protected fragment, but also four partially protected fragments were observed in the pectoralis muscle. Whole-mount in situ hybridization was performed in developing chick heart at H.H. stages 19, 21 and 30. The hybridization signal was intensive in the primitive atrium (H.H. stages 19 and 21) and in the atrial appendages derived from the primitive atrium (H.H. stage 30). Weak signals were detected in the primitive ventricle (H.H. stages 19 and 21), the ventricle (H.H. stage 30) and in the somites (H.H. stages 19 and 21).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

[Endoscopic mucosal resection for radical treatment of esophageal cancer].

Clinico-pathological results of patients with superficial esophageal cancer was reviewed to determine the indications of endoscopic mucosal resection (EMR) for esophageal cancer as a radical treatment and to evaluate clinical results of EMR. The analysis on eighty-seven cases with superficial esophageal cancer who underwent esophagectomy revealed no lymph node metastasis in any 0% of case with cancer confined to the lamina propria mucosae, 10% of cancer reaching the muscularis mucosae and 43% of cancer infiltrating the submucosa. These results suggested that the endoscopic mucosal resection should be indicated for patients with esophageal cancer confined to the lamina propria mucosae. The accuracy rate for estimating depth of invasion of mucosal cancer of the esophagus was 96%. We early established "the double channel technique" for resection of mucosal lesion of the esophagus with a major part of the submucosa, we used it for sixty-nine cases, and all were eventually discharged. Immediate complications of EMR were noted in 12.9% of all cases (mediastinal emphysema: 2.9%, ulcer bleeding: 10%) and the late complication in 7.2% (esophageal stricture due to scar formation: 5.8% and ulcer bleeding 5 days after EMR: 1.4%). All cases who developed stricture had mucosal defect over 3/4 the circumference. The cumulative 5-year survival rate of patients with esophageal mucosal cancer treated by EMR (86%) showed no significant difference from those treated by esophagectomy (83.2%). We to conclude that endoscopic mucosal resection is indicated for the patient with mucosal cancer confined to the lamina propria mucosae. One can expect an excellent prognosis by less invasive treatment than esophagectomy.

Esophageal Neoplasms↗
PubMed1995

The influence of Helicobacter pylori infection on the progression of gastric mucosal atrophy and occurrence of gastric cancer.

AIM: To study the effects of Helicobacter pylori infection on the progression of gastric mucosal atrophy and the development of gastric cancer. PATIENTS AND METHODS: We investigated the extension of the atrophic area as assessed on the basis of the Kimura-Takemoto atrophic patterns and the development of gastric cancer in a selected sample of 64 patients who were endoscopically followed up for more than 3 years, and who showed H. pylori infection by culture at the start of the investigation and at some stages during the follow-up. RESULTS: No progression of atrophy was observed in 14 patients who were H. pylori-negative at the beginning of the follow-up, whereas various degrees of expansion of the atrophic area were found in 22% of 50 positive cases. Well differentiated mucosal cancer was diagnosed in four patients during the follow-up. These patients displayed moderate to severe atrophy. At the beginning of the follow-up, 50% of patients were H. pylori culture-positive, but all patients had H. pylori antibodies in their blood. CONCLUSIONS: The results support the view that H. pylori infection influences the development of atrophic gastritis and is related to the pathogenesis of gastric cancer.

Adult↗
PubMed1994

Confirmation that the conotruncal anomaly face syndrome is associated with a deletion within 22q11.2.

The so-called "conotruncal anomaly face syndrome" (CTAFS) is characterized by a peculiar facial appearance associated with congenital heart disease (CHD), especially cardiac outflow tract defects such as tetralogy of Fallot (TOF), double outlet right ventricle (DORV), and truncus arteriosus (TAC). CTAFS and the DiGeorge anomaly (DGA) have many similar phenotypic characteristics, suggesting that they share a common cause. In many cases DGA is known to be associated with monosomy for a region of chromosome 22q11.2. Fifty CTAFS patients and 10 DGA patients, 11 parents couples and 10 mothers of CTAFS patients, and 3 parents couples and 2 mothers of DGA patients were examined by fluorescent in situ hybridization (FISH) using the N25 (D22S75) DGCR probe (Oncor). Monosomy for a region of 22q11.2 was found in 42 CTAFS, 9 DGA, 4 mothers, and 1 father who had CTAF without CHD. The remaining 8 CTAFS patients 1 DGA patient and 1 mother who had questionable CTAF without CHD, showed no such chromosome abnormality. For the control, 60 patients who had CHD without CTAF or other known malformation syndromes were examined and had no deletion of 22q11.2. Therefore, we conclude that CTAFS is a part of the CATCH 22 syndrome; cardiac defects, abnormal faces, thymic hypoplasia, cleft palate, and hypocalcemia (CATCH) resulting from 22q11.2 deletions.

Abnormalities, Multiple↗