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Biomedical subjects

M Momoi

Publications and source records attributed to M Momoi.

At least 19 recordsLinked to original sources

Comparison of computer-assisted instruction (CAI) versus traditional textbook methods for training in abdominal examination (Japanese experience).

PURPOSE: This study aimed to compare the effects of computer-assisted, text-based and computer-and-text learning conditions on the performances of 3 groups of medical students in the pre-clinical years of their programme, taking into account their academic achievement to date. A fourth group of students served as a control (no-study) group. METHOD: Participants were recruited from the pre-clinical years of the training programmes in 2 medical schools in Japan, Jichi Medical School near Tokyo and Kochi Medical School near Osaka. Participants were randomly assigned to 4 learning conditions and tested before and after the study on their knowledge of and skill in performing an abdominal examination, in a multiple-choice test and an objective structured clinical examination (OSCE), respectively. Information about performance in the programme was collected from school records and students were classified as average, good or excellent. Student and faculty evaluations of their experience in the study were explored by means of a short evaluation survey. RESULTS: Compared to the control group, all 3 study groups exhibited significant gains in performance on knowledge and performance measures. For the knowledge measure, the gains of the computer-assisted and computer-assisted plus text-based learning groups were significantly greater than the gains of the text-based learning group. The performances of the 3 groups did not differ on the OSCE measure. Analyses of gains by performance level revealed that high achieving students' learning was independent of study method. Lower achieving students performed better after using computer-based learning methods. CONCLUSION: The results suggest that computer-assisted learning methods will be of greater help to students who do not find the traditional methods effective. Explorations of the factors behind this are a matter for future research.

Abdomen↗

Simultaneous voiding cystourethrography and voiding urosonography reveals utility of sonographic diagnosis of vesicoureteral reflux in children.

AIM: To evaluate the diagnostic potential of voiding urosonography (VUS) compared with fluoroscopic voiding cystourethrography (VCUG) under identical conditions and to evaluate potential reasons for false-negative VUS results, particularly regarding bladder concentrations of the US contrast agent, Levovist. METHODS: Fifty-six paediatric patients (M/F 34/22, mean age 2.3 y, age range 1 mo-14 y) underwent simultaneous VUS and VCUG under identical conditions. The bladder was filled by simultaneous administration of Levovist and the X-ray contrast medium, DIP Conray. Levovist concentrations in bladders were calculated using amounts of Levovist injected and total DIP Conray infused when reflux was first observed in either procedure. RESULTS: Sensitivities of VUS and VCUG for detection of vesicoureteral reflux (VUR) were both 86%, assuming that VUR detected by either method represented a true-positive, and no reflux by either method represented a true-negative. Patients under 24-mo of age displayed a better VUS sensitivity, of 94%. Levovist concentrations in bladders ranged from 1.8% to 23%, with older children tending to demonstrate increased bladder capacity and lower concentration. All VUS false-negative units displayed Levovist bladder concentrations of less than 5%. CONCLUSION: The present simultaneous study suggests that: 1) the two techniques demonstrate similar sensitivity for detection of reflux; 2) sustained Levovist bladder concentrations of below 5% may not allow detection of reflux on VUS; and 3) VUS represents a suitable technique, particularly for small children whose bladder capacity is not so large.

Adolescent↗

An 8-cM interstitial deletion on 4q21-q22 in DNA from an infant with hepatoblastoma overlaps with a commonly deleted region in adult liver cancers.

We performed molecular analysis of a germline interstitial deletion of chromosome 4 [del(4)(q21.22q23)], which had been observed in a male infant manifesting early-onset hepatoblastoma (HBL). The chromosomal anomaly in this child was associated with a unique congenital syndrome including HBL, atrial septal defect, ventricular septal defect, patent ductus arteriosus, mental retardation, and seizures. However, the patient did not exhibit a megalencephaly typical of 4q21-22 deletions. His HBL was associated with an increasing serum alpha-fetoprotein level and rapid growth. To define the chromosomal deletion at the molecular level in this child, we analyzed his lymphoblasts with fluorescence in situ hybridization, using as probes a panel of BAC/PAC genomic clones containing STS markers covering the 4q12-27 region. The analysis revealed that the affected chromosome had an 8-cM deletion within 4q21-q22, flanked by markers D4S2964 and D4S2966. This microdeletion overlaps with the commonly deleted region at 4q21-q22 that was recently defined in adult hepatocellular carcinomas.

Adult↗

Cholangitis associated with cystic dilatation of the intrahepatic bile ducts after antireflux valve construction in biliary atresia.

An intussusception-type antireflux valve (ARV) has been introduced to prevent postoperative ascending cholangitis in the management of biliary atresia (BA). We investigated the characteristics of cholangitis in the management of BA using the ARV in 38 patients who had undergone an operation at our institution; 29 underwent ARV construction at the same time as portenterostomy (PEO) or hepaticojejunostomy. One patient underwent ARV construction for refractory cholangitis with cystic dilatation of the intrahepatic bile ducts (CDIB) long after the PEO. Five of 29 patients who had ARV construction developed CDIB complicated by severe, refractory cholangitis. One or two episodes of mild cholangitis were observed in 5 (20.8%) of 24 patients who did not show CDIB. An ARV created for postoperative recurrent cholangitis associated with CDIB was ineffective. Preoperative cholangitis associated with a type I choledochal cyst and CDIB was observed in 1 patient. In conclusion, the ARV was effective in preventing refractory cholangitis without CDIB, but ineffective in preventing cholangitis with CDIB. Our findings suggest that CDIB resulting from the ongoing process of BA could be a potential target of bacterial infection through other routes than bilioenteric reflux.

Bile Ducts, Intrahepatic↗

Influence of climatic factors in the incidence of upper gastrointestinal bleeding.

BACKGROUND AND AIM: Previous reports have indicated seasonal fluctuations in the incidence of peptic ulcer activity, but the reasons for the seasonal pattern are not clear. We assessed the seasonal incidence of hematemesis caused by peptic ulcers or gastroesophageal varices, and the correlations between those and climatic factors. METHODS: We examined the number of cases of upper gastrointestinal (GI) bleeding caused by gastric ulcer (GU), duodenal ulcer (DU), or gastroesophageal varices (varix) diagnosed by urgent endoscopies between 1 January 1996 and 31 December 1999 in our hospital (Tokyo Metropolitan Bokutou Hospital). We evaluated the monthly and seasonal incidence of them and investigated correlations among the incidence and climatic factors. RESULTS: Four hundred and forty-one patients participated in this study, including 275 patients with GU (62.4%), 51 (11.6%) with DU, and 115 (26.0%) with varix. The number of cases of hematemesis caused by GU showed significant monthly and seasonal fluctuations (P = 0.0002, P = 0.0018): it decreased in summer and increased in autumn-winter. Moreover, there were inverse relations between the monthly number of cases of hematemesis caused by GU and the mean temperature (P = 0.0016) and vapor pressure (P = 0.0013), and a parallel relation to the mean atmospheric pressure (P = 0.0057). In contrast, the number of cases of hematemesis caused by DU and varices did not show any monthly or seasonal fluctuations. CONCLUSIONS: We found that the incidence of hematemesis because of GU had an inverse relationship to temperature and vapor pressure, and had a parallel relation to atmospheric pressure. Therefore, climatic factors may play an important role in hemorrhage from GU.

Climate↗

A member of Forkhead family transcription factor, FKHRL1, is one of the downstream molecules of phosphatidylinositol 3-kinase-Akt activation pathway in erythropoietin signal transduction.

The phosphatidylinositol 3-kinase (PI3K) signaling pathway is important for the regulation of a number of cellular responses. Serine/threonine kinase Akt (protein kinase B; PKB) is downstream of PI3K and activated by growth factors. This study found that erythropoietin (EPO) induced tyrosine phosphorylation of Akt in a time- and dose-dependent manner in EPO-dependent human leukemia cell line UT-7/EPO. In vitro kinase assay using histone H2B and glucose synthase kinase as substrates demonstrated that Akt was actually activated by EPO. EPO-induced phosphorylation of Akt was completely blocked by a PI3K-specific inhibitor, LY294002, at 10 micromol/L, indicating that activation of Akt by EPO is dependent on PI3K activity. In addition, overexpression of the constitutively active form of Akt on UT-7/EPO cells partially blocked apoptosis induced by withdrawal of EPO from the culture medium. This finding suggested that the PI3K-Akt activation pathway plays some role in the antiapoptotic effect of EPO. EPO induced phosphorylation of a member of the trancription factor Forkhead family, FKHRL1, at threonine 32 and serine 253 in a dose- and time-dependent manner in UT-7/EPO cells. Moreover, results showed that Akt kinase activated by EPO directly phosphorylated FKHRL1 protein and that FKHRL1 phosphorylation was completely dependent on PI3K activity as is the case for Akt. In conjunction with the evidence that FKHRL1 is expressed in normal human erythroid progenitor cells and erythroblasts, the results suggest that FKHRL1 plays an important role in erythropoiesis as one of the downstream target molecules of PI3K-Akt.

DNA-Binding Proteins↗

Inhibition of cytokinesis by a lipid metabolite, psychosine.

Although a number of cellular components of cytokinesis have been identified, little is known about the detailed mechanisms underlying this process. Here, we report that the lipid metabolite psychosine (galactosylsphingosine), derived from galactosylceramide, induced formation of multinuclear cells from a variety of nonadherent and adherent cells due to inhibition of cytokinesis. When psychosine was added to the human myelomonocyte cell line U937, which was the most sensitive among the cell lines tested, cleavage furrow formed either incompletely or almost completely. However, abnormal contractile movement was detected in which the cellular contents of one of the hemispheres of the contracting cell were transferred into its counterpart. Finally, the cleavage furrow disappeared and cytokinesis was reversed. Psychosine treatment also induced giant clots of actin filaments in the cells that probably consisted of small vacuoles with filamentous structures, suggesting that psychosine affected actin reorganization. These observations could account for the formation of multinuclear globoid cells in the brains of patients with globoid cell leukodystrophy, a neurological disorder characterized by the accumulation of psychosine due to galactosylceramidase deficiency.

Actins↗

Abnormal pattern of flow in the superior caval vein in children after open heart surgery.

To investigate the pattern of flow in the superior caval vein in children after open heart surgery, we examined the flow velocity curves in 37 patients who had undergone surgical correction of either ventricular or atrial septal defects. The control group consisted of 64 age-matched children. We used pulsed Doppler examinations to record the velocity curves. We measured the highest and lowest peak flow velocities during systole and diastole, and calculated ratios for the various measurements. We found that the velocity of the wave in systole is lower than that of the wave in diastole in the postoperative patients, which is contrary to the normal pattern. The velocity in systole increases more than that in diastole during inspiration, which is also different from the normal pattern. The change in pattern of flow velocity curve during respiration was smaller in patients after surgery than in normal subjects, which might indicate that there is less reserve ability in the right atrium in postoperative patients.

Adolescent↗

Diffuse angiodysplasia of the upper gastrointestinal tract in a patient with hypertrophic obstructive cardiomyopathy.

A 64-year-old woman with a known history of hypertrophic obstructive cardiomyopathy presented with severe anemia of unknown origin. She had also suffered from repeated episodes of upper gastrointestinal bleeding for the previous 3 years. Despite bone marrow examination and panendoscopic and angiographic studies, the origin of anemia remained undefined until a small bleeding site was found during a duodenoscopic examination. The lesion proved to be angiodysplasia. This case report is interesting in that angiodysplasia elicited gastrointestinal bleeding and was the cause of anemia. In the international literature, there are very few reported cases of bleeding from gastrointestinal angiodysplasia in association with subvalvular aortic obstruction.

Anemia↗

Case report: acute encephalitis immediately prior to acute onset of hepatitis C virus infection.

A 34-year-old male presented with acute viral encephalitis of unknown aetiology with subsequent acute onset of hepatitis C virus (HCV) infection. Although the neurological syndrome improved after administration of acyclovir, jaundice appeared. Neurological complications of HCV infections have rarely been described. In this case report, we discuss the close relationship between neurological syndromes and HCV infection. In the future, we hope that further discussion of clinical cases will determine whether or not the HCV produces neurological manifestations.

Acute Disease↗

Lower risks of adverse outcome in twins conceived by artificial reproductive techniques compared with spontaneously conceived twins.

The outcomes of twins conceived by 136 women after medical assistance (MA) such as ovulation induction with or without assisted reproductive techniques, and twins conceived spontaneously (SP) by 72 women were compared. All 208 women were monitored from < 20 weeks gestation; they all delivered at > or = 24 weeks gestation. The chorionicity of the placenta was diagnosed antenatally and confirmed after delivery. There were 10 perinatal deaths; the physical and neurological status of the remaining 406 infants was assessed at 1 year of corrected age. There were no differences in gestational age at birth, the birth weights of the larger and smaller twins, the birth weight discordance, or the incidence of life-threatening major malformations between groups. Adverse infant outcomes, such as death, cerebral palsy and mental retardation occurred in nine (3.3%) of 272 MA twins compared with 12 (8.3%) of 144 SP twins (P < 0.05). The placenta was monochorionic in only three (2.2%) of 136 MA twin pregnancies compared with 41 (57%) of 72 SP twin pregnancies (P < 0.001). Of the 21 infants with adverse outcomes, nine had monochorionic placentas. Thus, the risk of an adverse outcome was 2.8-fold higher (95% confidence interval (CI) 1.2-6.4) in monochorionic twins than in dichorionic twins (10 versus 3.7%; P < 0.05). There was no difference in the incidence of adverse infant outcomes between SP (4.8%) and MA (3.4%) twins with dichorionic placentas. These findings suggest that ovulation induction in itself was not associated with an adverse outcome of twin pregnancies. The lower frequency of monochorionic placentas in MA twins may have been responsible for the lower risk of an adverse outcome in MA twins.

Birth Weight↗

Drastic genetic instability of tumors and normal tissues in Turcot syndrome.

Turcot syndrome is characterized by an association of malignant brain tumors and colon cancer developing in the patient's teens. Since the mechanism of carcinogenesis in Turcot syndrome is still unclear, we analysed genetic changes in tumors from a Turcot patient with no family history of the condition. All tumors, including one astrocytoma, three colon carcinomas, and two colon adenomas, exhibited severe replication error (RER), and all colon tumors showed somatic mutations at repeated regions of TGFbetaRII, E2F-4, hMSH3, and/or hMSH6 genes. Somatic APC mutations were detected in three of three colon carcinomas, and somatic p53 mutations were detected in the astrocytoma and two of three colon carcinomas, both of which showed two mutations without allele loss. We also found that normal colon mucosa, normal skin fibroblasts and normal brain tissue from this patient showed respective high frequencies of RER, in contrast to usual HNPCC patients in which RER was very rare in normal tissues. These results suggest that extreme DNA instability in normal tissues causes the early development of multiple cancer in Turcot syndrome. A missense mutation (GAG to AAG) at codon 705 of hPMS2 gene was detected in one allele of this patient, which was inherited from his mother without tumors. Additional unknown germline mutation may contribute to the genetic instability in normal tissues.

Adenocarcinoma↗

Loss of circulating hepatitis C virus in children who developed a persistent carrier state after mother-to-baby transmission.

Of the 15 babies born to mothers infected with hepatitis C virus (HCV) and followed since birth, three developed HCV RNA in their serum. HCV RNA disappeared in two infants within 2 mo, but it persisted in the remaining infant. Mother-to-baby transmission was diagnosed retrospectively in an additional eight children aged 0.8-13.6 y. The eight children were followed for 1.4-5.0 y (mean +/- SD: 3.2 +/- 1.3 y) until they were 3.3-16.7 y old (8.5 +/- 4.3 y). Serum HCV RNA disappeared and antibodies to HCV decreased in the titer in two of the children when they were 3 y old. The spontaneous loss of serum HCV RNA was not observed in any of the other 14 children with posttransfusion infection who were followed for 2.6-6.1 y (4.0 +/- 1.1 y), until 3-22 y from the time they received transfusions and when they were 8.4-22.8 y old (15.4 +/- 4.1 y). These results indicate that the vertical transmission of HCV is rare, and some children can resolve the infection after a few years, whereas the infection persists in children who are infected by transfusion.

Adolescent↗

[An experiment in a new method of nursing education--the problem-based learning for prenatal nursing].

At the opening of lectures in 1995 on the Science of maternity Nursing in the Special Subjects of Nursing, a problem-based learning was tried as a new educating method in the unit of "Prenatal Nursing." In the present paper, reviewing the introduction/implementation of the method, subjects in the future are described. This process contained two major flows, one was the training of tutors in problem-based learning, including participating the workshop held at McMaster University, and the other was the preparation for the class at the introduction of the new educational method, such as the overall subject composition and the development of teaching materials of prenatal nursing and resources, etc. according to the procedures of the problem-based learning. As the results of the actual implementation, various different reactions in comparison with the lecture method were observed both in tutors and students. As the subjects hereafter, the following three points have been clearly elucidated, that is, in order to proceed the problem-based learning under the present condition that it is not in the comprehensive curriculum, to prevent the overload and conflict in the student learning, considering and adjusting the relationship with contents and methods of concurrent subjects and units, to establish the system for tutorial assessment and evaluation, and to insure tutors and fulfill their training system.

Curriculum↗