[Surgery for mitral regurgitation in children]

In pediatric patients, mitral valve (MV) repair is preferable than MV replacement because of no need for anticoagulation and its feasibility in small children. However, long-term outcome of MV repair is still unclear. In the present study, fifty-two pediatric patients who underwent MV repair (n = 46) and MV replacement (n = 6) against mitral regurgitation (MR) between January 1970 and December 1996 were evaluated. 46 patients had associated diseases. Mitral annuloplasty was applied in 20 patients (by Kay method (n = 14) and Paneth-Burr method (n = 6) before and after 1991, respectively). Freedom from reoperation rate in patients with partial endocardial cushion defect (ECD) was significantly lower than that in other patients after MV repair, which was significantly higher than that in patients with MV replacement. Diameter of mitral annulus grew within normal range after MV repair. In conclusion, MV repair may provide better outcomes with respect to reoperation and growth of MV in pediatric patients except with partial ECD.

Localization of nitric oxide synthase in human nasal mucosa with nasal allergy

Nitric oxide (NO) plays an important role in the regulation of upper respiratory function. In the nasal cavity, the concentration of NO in the air in patients with untreated allergic rhinitis is higher than that in normal individuals. NO is produced by the action of NO synthase (NOS) using L-arginine as a substrate. To investigate the expression of NOS in human nasal mucosa, histochemical staining for NADPH diaphorase and immunohistochemical staining for NOS isoforms were carried out in nasal inferior turbinate mucosa from patients with nasal allergy. Those without nasal allergy served as controls. NADPH diaphorase histochemical study revealed that NOS was expressed in the nasal epithelium, submucosal glands, nerve fibres and the endothelium in specimens of both allergic and control groups. Immunoreactivity to endothelial NOS (eNOS) was localized to epithelial and endothelial cells in both allergic and control groups. In some specimens in both groups, nerve fibres around submucosal glands stained positively for eNOS. Immunoreactivity to eNOS, however, was slightly stronger in the epithelia of the allergic group than in those of the controls. Immunoreactivity to inducible NOS (iNOS) was localized to epithelial cells, endothelial cells, nasal glands and inflammatory cells. The staining of epithelial cells and inflammatory cells was more marked in the allergic group than the controls. These findings may suggest that the greater amounts of NO in the nasal air of patients with allergic rhinitis are mainly induced by iNOS activity.

Pancreatic neoplasms with abundant mucus production: emphasis on intraductal papillary-mucinous tumors and mucinous cystic tumors

The clinicopathologic features and problems in classification and diagnosis of the pancreatic neoplasms with abundant mucus production are presented. In this article, the various reported concepts and terminology of these mucus-producing pancreatic tumors are summarized, and the differences between intraductal papillary-mucinous tumors and mucinous cystic tumors are specifically discussed. Intraductal papillary-mucinous tumors show diffuse or segmental dilatation of the pancreatic ducts with intraductal papillary growth. Mucinous cystic tumors are mucus-producing tumors showing cyst formation, which is often accompanied by intracystic papillary projections and "ovarian-type" stroma. Intraductal papillary-mucinous tumors occur most often in the pancreatic head of elderly men, whereas mucinous cystic tumors typically occur in the pancreatic tail or body of middle-aged women. Histologically, these tumors show a wide cytologic spectrum from benign to borderline to malignant. These tumors pursue an indolent clinical course compared with conventional ductal carcinoma of the pancreas. Mucinous cystadenocarcinomas have a higher malignant potential than intraductal papillary-mucinous adenocarcinomas, yet these tumors recur infrequently if they are excised completely. Because of the differences in clinicopathologic features, these tumors should be clearly separated from conventional ductal carcinoma of the pancreas.

Lysophosphatidic acid stimulates neurotransmitter-like conductance changes that precede GABA and L-glutamate in early, presumptive cortical neuroblasts

During neurogenesis in the embryonic cerebral cortex, the classical neurotransmitters GABA and L-glutamate stimulate ionic conductance changes in ventricular zone (VZ) neuroblasts. Lysophosphatidic acid (LPA) is a bioactive phospholipid producing myriad effects on cells including alterations in membrane conductances (for review, see Moolenaar et al., 1995). Developmental expression patterns of its first cloned receptor gene, lpA1/vzg-1 (Hecht et al., 1996; Fukushima et al., 1998) in the VZ suggested that functional LPA receptors were synthesized at these early times, and thus, LPA could be an earlier stimulus to VZ cells than the neurotransmitters GABA and L-glutamate. To address this possibility, primary cultures of electrically coupled, presumptive cortical neuroblast clusters were identified by age, morphology, electrophysiological profile, BrdU incorporation, and nestin immunostaining. Single cells from cortical neuroblast cell lines were also examined. Whole-cell variation of the patch-clamp technique was used to record from nestin-immunoreactive cells after stimulation by local administration of ligands. After initial plating at embryonic day 11 (E11), cells responded only to LPA but not to GABA or L-glutamate. Continued growth in culture for up to 12 hr produced more LPA-responsive cells, but also a growing population of GABA- or L-glutamate-responsive cells. Cultures from E12 embryos showed LPA as well as GABA and L-glutamate responses, with LPA-responsive cells still representing a majority. Overall, >50% of cells responded to LPA with depolarization mediated by either chloride or nonselective cation conductances. These data implicate LPA as the earliest reported extracellular stimulus of ionic conductance changes for cortical neuroblasts and provide evidence for LPA as a novel, physiological component in CNS development.

Comparative analysis of three murine G-protein coupled receptors activated by sphingosine-1-phosphate

The cloning and analysis of the first identified lysophosphatidic acid (LPA) receptor gene, lpA1 (also referred to as vzg-1 or edg-2), led us to identify homologous murine genes that might also encode receptors for related lysophospholipid ligands. Three murine genomic clones (designated lpB1, lpB2, and lpB3) were isolated, corresponding to human/rat Edg-1, rat H218/AGR16, and human edg-3, respectively. Based on the amino acid similarities of their predicted proteins (44-52% identical), the three lpB genes could be grouped into a separate G-protein coupled receptor subfamily, distinct from that containing the LPA receptor genes lpA1 and lpA2. Unlike lpA1 and lpA2, which contain multiple coding exons, all lpB members contained a single coding exon. Heterologous expression of individual lpB members in a hepatoma cell line (RH7777), followed by 35S-GTPgammaS incorporation assays demonstrated that each of the three LPB receptors conferred sphingosine-1-phosphate-dependent, but not lysophosphatidic acid-dependent, G-protein activation. Northern blot and in situ hybridization analyses revealed overlapping as well as distinct expression patterns in both embryonic and adult tissues. This comparative characterization of multiple sphingosine-1-phosphate receptor genes and their spatiotemporal expression patterns will aid in understanding the biological roles of this enlarging lysophospholipid receptor family.

The prevalence of mitochondrial gene mutations in childhood diabetes in Japan

To investigate the prevalence of mitochondrial DNA mutations among Japanese children with IDDM as well as in those with NIDDM, a total of 155 patients with IDDM and 30 patients with NIDDM who were younger than 15 years of age at onset were studied for the following mtDNA mutations: 1) the A-->G mutation at position 3243 of mitochondrial leucine transfer RNA (3243 mutation); 2) the G-->A mutation at position 3316 of mitochondrial leucine transfer RNA (3316 mutation), and 3) The T-->C mutation at position 3394 of the mitochondrial NADH dehydrogenase subunit (3394 mutation). None of the 155 IDDM patients had the 3243 mutation. Although two of the 155 IDDM patients had homoplasmy of 3316 and five had 3394 mutations, these frequencies were not significant compared with healthy controls. None of the 30 NIDDM patients had the 3243, 3316 or 3394 mutation. The presence of these mutations even in control subjects suggests that the effect of the 3316 or 3394 mutation on mitochondrial function is relatively mild. It seems that 3316 and 3394 mutations contribute to the manifestation of diabetes together with other genetic and/or environmental factors.

Differential expression of laminin receptors in human hepatocellular carcinoma

BACKGROUND

Laminin receptors are involved in cell-extracellular matrix interactions in malignant cells that show invasion and metastasis. Hepatocellular carcinoma frequently shows early invasion into blood vessels, and intrahepatic and extrahepatic metastases. However, the role of laminin receptors in hepatocellular carcinoma is unknown.

AIMS

To examine the expression of mRNA for laminin receptors and their isoforms in hepatocellular carcinoma.

METHODS

The expression of several laminin receptors, including alpha1 integrin, alpha6 integrin and its isoforms alpha6A and alpha6B, beta1 integrin and its isoforms beta1A and beta1B, and 32kD/67kDa laminin binding protein was examined in human hepatocellular carcinomas and non-cancerous liver tissues using the reverse transcription polymerase chain reaction.

RESULTS

Alpha6 Integrin, beta1 integrin, and laminin binding protein showed notably increased expression in hepatocellular carcinoma, compared with non-cancerous liver tissue, although the alpha1 integrin did not show a significant change. Furthermore, beta1B integrin, a splicing variant of beta1 integrin, was overexpressed in hepatocellular carcinoma while the beta1A integrin isoform did not show significant changes between hepatocellular carcinoma and surrounding non-cancerous liver tissue.

CONCLUSIONS

The differential upregulation of laminin receptors and their splicing isoforms was shown in hepatocellular carcinoma, suggesting that certain laminin receptors and their isoforms may be involved in the development and progression of hepatocellular carcinoma.

Low-density induced apoptosis of cortical neurons is inhibited by serum factors

1. We investigated the survival of neurons under serum-free conditions without any exogenous signal molecules, using primary cultures of rat cerebral cortex. 2. Survival activity, measured with Alamar Blue, showed a cell density dependency under serum-free conditions. 3. The addition of fetal bovine serum suppressed the apoptotic cell death accompanied by DNA-laddering and fragmentation specific in low-density cultures, resulting in the disappearance of the cell density dependency of survival. 4. These findings suggest that serum factors may substitute for endogenous survival factors from cortical neurons in high-density cultures.

Descriptive epidemiology of IDDM in Hokkaido, Japan: the Childhood IDDM Hokkaido Registry

OBJECTIVE

To identify the incidence of IDDM with regard to sex, age, family history of diabetes, season, and 5-year period of childhood IDDM among children ages 0-14 years from a population-based epidemiological study in Hokkaido, Japan, from 1973 to 1992.

RESEARCH DESIGN AND METHODS

Registration of all new IDDM cases in Hokkaido was conducted by the Childhood IDDM Hokkaido Registry Study Group from 1973 to 1992. The cases were selected from among 1) patients who were admitted to the member hospitals of the study group, 2) patients who answered a questionnaire distributed to hospitals and diabetic clinics throughout Hokkaido, and 3) patients whose cases were recorded in free-treatment medical records of urban and rural districts. The case ascertainment rate was estimated to be 100%. Differences in incidence with regard to sex, age, family history of diabetes, season, and year period were analyzed by the Poisson regression analysis by GENMOD.

RESULTS

During the 20-year period studied, 396 cases (181 boys, 215 girls) of abrupt-onset IDDM were registered. Statistically significant differences in annual incidence were found according to sex (female), age (8-14 years), history (having no diabetes in family), season (spring), and 5-year period.

CONCLUSIONS

This is the first population-based, long-term epidemiological study of childhood IDDM from Japan. We observed a significantly higher annual incidence (per 100,000/year) of IDDM in female subjects (1.81), older age-groups (2.25 for 8-14 years), subjects with no family history of diabetes (1.26), diabetes onset in the spring (2.20), and an increased trend over the 20 years. In addition, the heterogeneity of IDDM among Japanese children needs to be elucidated.

Successful experimental multiorgan transplant from non-heart-beating donors using percutaneous cardiopulmonary support

Organ procurement from non-heart-beating donors (NHBDs) may expand donor pools. In this study, the method of reanimation of heart, lung, and kidney in NHBDs by percutaneous cardiopulmonary support (PCPS) was evaluated. Thirteen beagles were asphyxiated after being given prostacyclin analogue, verapamil, propranolol, and nafmostat mesilate intravenously. Thirty minutes after cardiac arrest, the body was reperfused by PCPS for 1 hr. PCPS priming fluid contained the four drugs above and KCl. Eight hearts immersed in University of Wisconsin (Madison, WI) solution for 24 hr were transplanted orthotopically using leukocyte depleted blood cardioplegia, five left lungs immersed in modified Collins solution were transplanted orthotopically, and five kidneys immersed in University of Wisconsin solution were transplanted heterotopically. All donor hearts arrested without ventricular fibrillation. All transplanted hearts beat spontaneously, and all animals were weaned from cardiopulmonary bypass without inotropic support. The oxygen and carbon dioxide pressure of pulmonary vein blood in the donor lung were no different from those in the recipient lung. All transplanted kidneys made urine soon after reperfusion. These data suggested that hearts, lungs, and kidneys from NHBDs pretreated with four drugs and reanimated with PCPS can be transplanted successfully and that this method may expand the donor pool.

[Decongesting effect of tramazoline on nasal airway patency and nasal symptoms as evaluated by acoustic rhinometry: an objective study in 30 allergic and six non-allergic subjects]

In this prospective clinical study, we investigated the effect of the nasal decongestant tramazoline on nasal airway patency in 30 subjects with perennial nasal allergy to housedust mites and in six non-allergic volunteers who served as controls. The allergic subjects were further subdivided into groups, the severe group and the moderate group, according to the level of specific IgE. We used acoustic rhinometry as an objective method, and the nasal cavity volume (NCV) and the minimum cross-sectional area (MCA) were measured before and 10 minutes after nasal spraying. Before mucosal decongestion, the average NCV in the severe group was 5.94 cm3, which was significantly lower than those in the other two groups: 7 cm3 in the control group and 8.13 cm3 in the moderate group, respectively (P = 0.02). A more significant difference was found when the first 3-cm area of the NCV was evaluated (P = 0.009). Pharmacologic decongestion caused an increase in nasal patency by 54% from the baseline NCV values in the control group, 38% in the moderate group and 48% in the severe group. There was no significant difference among the three groups. Changes in nasal symptoms were also determined by questionnaire. The degree of improvement in subjective nasal congestion was more pronounced in the allergic groups than in the control group.

A single receptor encoded by vzg-1/lpA1/edg-2 couples to G proteins and mediates multiple cellular responses to lysophosphatidic acid

Extracellular lysophosphatidic acid (LPA) produces diverse cellular responses in many cell types. Recent reports of several molecularly distinct G protein-coupled receptors have raised the possibility that the responses to LPA stimulation could be mediated by the combination of several uni-functional receptors. To address this issue, we analyzed one receptor encoded by ventricular zone gene-1 (vzg-1) (also referred to as lpA1/edg-2) by using heterologous expression in a neuronal and nonneuronal cell line. VZG-1 expression was necessary and sufficient in mediating multiple effects of LPA: [3H]-LPA binding, G protein activation, stress fiber formation, neurite retraction, serum response element activation, and increased DNA synthesis. These results demonstrate that a single receptor, encoded by vzg-1, can activate multiple LPA-dependent responses in cells from distinct tissue lineages.

Onset age-dependent variations of three islet specific autoantibodies in Japanese IDDM patients

The age related incidence rate of insulin-dependent diabetes mellitus shows a bimodal distribution, not only in Caucasians but also in Japanese. To evaluate the onset age-related autoimmune profile at presentation in insulin-dependent diabetes mellitus (IDDM), glutamic acid decarboxylase (GAD) autoantibody, islet cell antibody (ICA), and insulin autoantibody (IAA) were measured in 137 newly diagnosed Japanese IDDM patients with onset ages between 0-29 years. The prevalence of GAD autoantibody was significantly increased from the lowest (32%) in the 0-5 years onset age group to 75% in the 13-19 years onset age group (P < 0.05), whereas the IAA prevalence significantly decreased from the peak (48%) in the 6-12 years onset age group to 10% in the 20-29 years onset age group (P < 0.05). The ICA prevalence was increased from the lowest (32%) in the 0-5 years onset age group to the highest (53%) in the 20-29 years onset age group similar to that for the GAD autoantibody. Such results demonstrate that there was age-related autoimmune characteristics at presentation of IDDM in Japanese as well as in Caucasians.

[Reoperation after the Fontan operation in single ventricle and tricuspid atresia]

The outcome of the Fontan-type operation for complex heart disease has been significantly improved, and low morbidity and mortality rates are reported. However, some problems still occur in late follow-up, including ventricular failure, hepatic congestion, supraventricular arrhythmia, cerebrovascular events, exercise intolerance, and residual or new cardiac lesions. Reinterventions after the Fontan-type operation for complex cardiac defects in 43 patients are reviewed. In addition to catheter interventions, the main reasons for reoperation were subaortic stenosis, pulmonary artery and vein obstructions, and interatrial shunt. Early intervention, particularly for subaortic obstruction, is recommended, and the Damus-Kay--Stansel anastomosis appears to be the procedure of choice. Reoperation was required in 6 of the 43 patients, with one operative death. The total event-free survival rate after 10 years of follow-up was 53%. The need for reoperation appears to be reduced after performing the total cavopulmonary shunt procedure compared to that after atriopulmonary connection. However, late arrhythmia remains a significant problem in this group of patients, and further assessment of the results of reintervention for arrhythmia is required.