Proteomic profile of nuclei containing p62-positive inclusions in a patient with neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in the neurons, glial cells, and other somatic cells. Although CGG repeat expansions in NOTCH2NLC have been identified in most East Asian patients with NIID, the pathophysiology of NIID remains unclear. Ubiquitin- and p62-positive intranuclear inclusions are the pathological hallmark of NIID. Targeted immunostaining studies have identified several other proteins present in these inclusions. However, the global molecular changes within nuclei with these inclusions remained unclear. Herein, we analyzed the proteomic profile of nuclei with p62-positive inclusions in a NIID patient with CGG repeat expansion in NOTCH2NLC to discover candidate proteins involved in the NIID pathophysiology. We used fluorescence-activated cell sorting and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify each protein identified in the nuclei with p62-positive inclusions. The distribution of increased proteins was confirmed via immunofluorescence in autopsy brain samples from three patients with genetically confirmed NIID. Overall, 526 proteins were identified, of which 243 were consistently quantified using MS. A 1.4-fold increase was consistently observed for 20 proteins in nuclei with p62-positive inclusions compared to those without. Fifteen proteins identified with medium or high confidence in the LC-MS/MS analysis were further evaluated. Gene ontology enrichment analysis showed enrichment of several terms, including poly(A) RNA binding, nucleosomal DNA binding, and protein binding. Immunofluorescence studies confirmed that the fluorescent intensities of increased RNA-binding proteins identified by proteomic analysis, namely hnRNP A2/B1, hnRNP A3, and hnRNP C1/C2, were higher in the nuclei with p62-positive inclusions than in those without, which were not confined to the intranuclear inclusions. We identified several increased proteins in nuclei with p62-positive inclusions. Although larger studies are needed to validate our results, these proteomic data may form the basis for understanding the pathophysiology of NIID.

ELISA Evaluation of Tau Accumulation in the Brains of Patients with Alzheimer Disease

Despite the routine use of sandwich enzyme-linked immunosorbent assays (ELISAs) for quantifying tau levels in CSF and plasma, tau accumulations in the brains of patients with Alzheimer disease (AD) have rarely been evaluated by this method. Thus, by introducing several tau ELISAs that target different epitopes, we evaluated accumulated tau levels in postmortem brains depending on disease stage, brain areas, and other AD-related changes. Notably, tau levels in insoluble fraction determined by each ELISAs differ depending on the epitopes of antibodies: non-AD control samples yield relatively high signals when an antibody against the N-terminal region of tau is used. On the other hand, ELISAs combining antibodies against the later-middle to C-terminal regions of tau produced substantially increased signals from AD samples, compared to those from non-AD controls. Such ELISAs better distinguish AD and non-AD controls, and the results are more closely associated with Braak neurofibrillary tangles stage, Aβ accumulation, and glial markers. Moreover, these ELISAs can reflect the pattern of tau spread across brain regions. In conclusion, Tau ELISAs that combine antibodies against the later-middle to C-terminal regions of tau can better reflect neuropathological tau accumulation, which would enable to evaluate tau accumulation in the brain at a biochemical level.

Neuron-specific analysis of histone modifications with post-mortem brains

Histone modifications govern chromatin structures and regulate gene expression to orchestrate cellular functions in the central nervous system, where neuronal cells are postmitotic and developmentally inactive, the functional and age-dependent changes also accumulate in the epigenetic states. Because the brain is composed of several types of cells, such as the neurons, glial cells, and vascular cells, the analysis of histone modifications using bulk brain tissue might obscure alterations specific to neuronal cells. Furthermore, among the various epigenetic traits, analysis of the genome-wide distribution of DNA methylation in the bulk brain is predominantly a reflection of DNA methylation of the non-neuronal cells, which may be a potential caveat of previous studies on neurodegenerative diseases using bulk brains. In this study, we established a method of neuron-specific ChIP-seq assay, which allows for the analysis of genome-wide distribution of histone modifications specifically in the neuronal cells derived from post-mortem brains. We successfully enriched neuronal information with high reproducibility and high signal-to-noise ratio. Our method will further facilitate the understanding of neurodegeneration.

Development of PCR Primers to Identify Fusarium oxysporum f. sp. fragariae

Fusarium oxysporum f. sp. fragariae is a fungal pathogen causing Fusarium wilt on strawberry. Polymerase chain reaction (PCR) primers that can discriminate F. oxysporum f. sp. fragariae from nonpathogenic F. oxysporum would greatly assist pathogen identification. In order to develop a molecular diagnostic tool for this pathogen, transposable elements in the pathogen were characterized and used for designing a specific set of PCR primers. Portions of the transposable elements Fot3, Han, Hop, Hornet1, and Skippy were detected in all 33 strains of F. oxysporum f. sp. fragariae tested by PCR, whereas Foxy was detected in 32 strains and Impala sequences were detected in 30 strains. Two types of sequences were detected for Hop, two types for Impala, and three types for Skippy. The genomic region between Han and Skippy was amplified by an inter-retrotransposon amplified polymorphism technique, and PCR primers (FofraF and FofraR) to specifically identify F. oxysporum f. sp. fragariae were designed from this region. The developed PCR primers discriminated F. oxysporum f. sp. fragariae strains from nonpathogenic F. oxysporum strains and five other formae speciales. Conidia of F. oxysporum f. sp. fragariae could be detected in brown lowland-type soil by PCR using the primers. After preculturing the soil sample on FoG2 medium, 1 × 10² conidia/g of soil could be detected; without preculturing, 1 × 10³ conidia/g of soil were detected.

Bepridil up-regulates cardiac Na+ channels as a long-term effect by blunting proteasome signals through inhibition of calmodulin activity

BACKGROUND AND PURPOSE

Bepridil is an anti-arrhythmic agent with anti-electrical remodelling effects that target many cardiac ion channels, including the voltage-gated Na+ channel. However, long-term effects of bepridil on the Na+ channel remain unclear. We explored the long-term effect of bepridil on the Na+ channel in isolated neonatal rat cardiomyocytes and in a heterologous expression system of human Na(v)1.5 channel.

EXPERIMENTAL APPROACH

Na+ currents were recorded by whole-cell voltage-clamp technique. Na+ channel message and protein were evaluated by real-time RT-PCR and Western blot analysis.

KEY RESULTS

Treatment of cardiomyocytes with 10 micromol.L(-1) bepridil for 24 h augmented Na+ channel current (I(Na)) in a dose- and time-dependent manner. This long-term effect of bepridil was mimicked or masked by application of W-7, a calmodulin inhibitor, but not KN93 [2-[N-(2-hydroxyethyl)-N-(4-methoxy benzenesulphonyl)]-amino-N-(4-chlorocinnamyl)-N-methylbenzylamine], a Ca2+/calmodulin-dependent kinase inhibitor. During inhibition of protein synthesis by cycloheximide, the I(Na) increase due to bepridil was larger than the increase without cycloheximide. Bepridil and W-7 significantly slowed the time course of Na(v)1.5 protein degradation in neonatal cardiomyocytes, although the mRNA levels of Na(v)1.5 were not modified. Bepridil and W-7 did not increase I(Na) any further in the presence of the proteasome inhibitor MG132 [N-[(phenylmethoxy)carbonyl]-L-leucyl-N-[(1S)-1-formyl-3-methylbutyl]-L-leucinamide]. Bepridil, W-7 and MG132 but not KN93 significantly decreased 20S proteasome activity in a concentration-dependent manner.

CONCLUSIONS AND IMPLICATIONS

We conclude that long-term exposure of cardiomyocytes to bepridil at therapeutic concentrations inhibits calmodulin action, which decreased degradation of the Na(v)1.5 alpha-subunit, which in turn increased Na+ current.

[Aortic regurgitation caused by prolapsed noncoronary cusp associated with dissecting aortic aneurysm treated by placing a prosthetic graft onto the anulus: report of a case]

A 70-year-old man with severe aortic regurgitation (AR) associated with dissecting aortic aneurysm underwent a radical operation. AR was thought to be due to dilated sinotubular junction and prolapsed noncoronary cusp caused by dissecting flap extended into the sinus of Valsalva. At operation, the noncoronary cusp was slightly prolapsed into the left ventricle, but all cusps were seemed to be thin and pliable. An isolated "tongue shaped" graft was placed onto the anulus of the noncoronary cusp, and a 26 mm Woven Dacron graft was used to replace the ascending aorta. Postoperative angiogram showed mild AR and improved left ventricular (LV) function. This procedure was effective to repair AR caused by prolapsed noncoronary cusp without elongation or thickening of the valve.

[Assessment of blood flow of the internal thoracic artery in patients with aortic stenosis]

The number of patients undergoing combined aortic valve replacement (AVR) for aortic stenosis (AS) and coronary artery bypass grafting (CABG) has been increasing. In CABG, the internal thoracic artery (ITA) is the preferred conduit for its long-term patency. Although Doppler studies on ITA have been widely used, flow characteristics of the vessel in patients with AS have not been reported. To evaluate blood flow pattern of the ITA in AS, duplex scanning was performed in 10 patients before and after AVR. Peak systolic velocity was measured, and blood flow was calculated from mean velocity and cross-sectional area. The mean diameters of the vessels were approximately 1.8 mm on both sides. AVR caused an increase in systolic velocities from 61.2 cm/sec to 85.5 cm/sec in right ITA and from 58.4 cm/sec to 84.7 cm/sec in left ITA. The flow volumes increased from 32.2 ml/min to 46.7 ml/min in right and increased from 31.6 ml/min to 46.3 ml/min in left after AVR. In simultaneous AVR for AS and CABG, suitability of the ITA should be assessed before its use, and concomitant AVR may be quite important to provide adequate flow of the ITA as a conduit.

[Surgical treatment of Budd-Chiari syndrome associated with superior vena cava obstruction; report of a case]

We report a case of a 37-year-old woman with Budd-Chiari syndrome who underwent a radical treatment. She had had ascites, general edema, and liver dysfunction for 5 years. Preoperative cineangiogram showed a membranous stenosis at the retrohepatic inferior vena cava and the catheter could not be advanced into superior vena cava. In the operation, obstructed superior vena cava was identified. Membranous tissue at retrohepatic inferior vena cava was removed, and patch cavoplasty was performed under circulatory arrest through Senning procedure. Postoperative cavogram revealed good patency of inferior vena cava and her symptoms were disappeared.

[Assessment of left internal thoracic artery grafts by atrial pacing]

The flow reactivity of a left internal thoracic artery graft (LITAG) in response to atrial pacing was evaluated in 14 patients who underwent coronary artery bypass grafting (CABG) with LITAG to left anterior descending artery (LAD). Systolic peak velocity and diastolic peak velocity were recorded using a duplex scanner of 7.5 MHz, and flow volumes in each phase and flow ratio were calculated. The external temporary atrial pacing was used to increase heart rates 25 and 50%. Diastolic peak velocity and flow volume increased predominantly on both pacing rates. In contrast, systolic peak velocity decreased when heart rate was raised 50%, and there was no significant difference between the pacing modes in systolic flow volumes. As a result, flow ratio increased predominantly on both pacing rates. Based on the present studies, there may be some advantages with atrial pacing to increase the LITAG flow in response to the myocardial oxygen demand.

[Assessment of saphenous vein grafts flow by Doppler echocardiography]

In an effort to evaluate flow characteristics of the saphenous vein grafts (SVG) after coronary artery bypass grafting, we performed duplex scanning of SVG which were anastomosed to the left anterior descending artery in 12 patients, and compared those indexes with 34 internal thoracic artery grafts (ITAG). The SVG were observed with a 7.5 MHz duplex scanner through the anterior intercostal space. The diameter of the vessel, systolic peak velocity, and diastolic peak velocity were recorded in both groups, and systolic flow volume, diastolic flow volume, and velocity ratio were calculated. The systolic and diastolic peak velocity of SVG were predominantly lower than ITAG. No difference in the diameter and flow ratio could not be demonstrated between 2 groups. The flow volume of SVG were also predominantly lower than that of ITAG throughout cardiac cycle. This study reveals that advanced stenotic change were caused in the SVG group and suggest the occurrence of vein grafts disease long after coronary artery bypass grafting.

Genetic factors are major determinants of phenotypic variability in a mouse model of the DiGeorge/del22q11 syndromes

The del22q11 syndrome is associated with a highly variable phenotype despite the uniformity of the chromosomal deletion that causes the disease in most patients. Df1/+ mice, which model del22q11, present with reduced penetrance of cardiovascular defects similar to those seen in deleted patients but not with other del22q11-like findings. The reduced penetrance of cardiovascular defects is caused by the ability of mutant embryos to recover from a fourth pharyngeal arch artery growth abnormality that is fully penetrant in early embryos. Here we show that genetic background has a major effect on penetrance of cardiovascular defects by affecting this embryonic recovery process. This effect could not be explained by allelic variation at the haploid locus, and it is likely to be caused by genetic modifiers elsewhere in the genome. We also show that genetic factors control extension of the Df1/+ phenotype to include thymic and parathyroid anomalies, establishing the Df1 mouse as a model for the genetic analysis of three major features of human del22q11 syndrome. We found that in Df1/+ mice, as in human patients, expression of the heart and thymic phenotypes are essentially independent from each other, suggesting that they may be controlled by different genetic modifiers. These data provide a framework for our understanding of phenotypic variability in patients with del22q11 syndrome and the tools for its genetic dissection.

[Assessment of left internal thoracic artery graft by exercise Doppler echocardiography]

Doppler echocardiography has several advantages such as frequent use, noninvasive approach, and physiological evaluation. Supine bicycle exercise testing was conducted for 30 patients undergoing CABG with LITA to LAD. Doppler echocardiography studies were performed before and after exercise to observe the change. On the basis of the angiographic data, patients were divided into two groups: 27 patients with a patent LITA graft, 3 patients with mildly stenosed LITA graft. In the patients who had patent grafts, diastolic flow velocity were increased higher than systolic after exercise. In the stenotic group, the flow pattern was changed to further systolic one. Doppler echocardiography during exercise is thought to be a reliable method to assess the LITA flow.

Activity-dependent transfer of brain-derived neurotrophic factor to postsynaptic neurons

Neurotrophins such as brain-derived neurotrophic factor (BDNF) are thought to be transferred from post- to presynaptic neurons and to be involved in the formation and plasticity of neural circuits. However, direct evidence for a transneuronal transfer of BDNF and its relation to neuronal activity remains elusive. We simultaneously injected complementary DNAs of green fluorescent protein (GFP)-tagged BDNF and red fluorescence protein into the nucleus of single neurons and visualized expression, localization, and transport of BDNF in living neurons. Fluorescent puncta representing BDNF moved in axons in the anterograde direction, though some moved retrogradely, and transferred to postsynaptic neurons in an activity-dependent manner.

Tbx1 haploinsufficieny in the DiGeorge syndrome region causes aortic arch defects in mice

DiGeorge syndrome is characterized by cardiovascular, thymus and parathyroid defects and craniofacial anomalies, and is usually caused by a heterozygous deletion of chromosomal region 22q11.2 (del22q11) (ref. 1). A targeted, heterozygous deletion, named Df(16)1, encompassing around 1 megabase of the homologous region in mouse causes cardiovascular abnormalities characteristic of the human disease. Here we have used a combination of chromosome engineering and P1 artificial chromosome transgenesis to localize the haploinsufficient gene in the region, Tbx1. We show that Tbx1, a member of the T-box transcription factor family, is required for normal development of the pharyngeal arch arteries in a gene dosage-dependent manner. Deletion of one copy of Tbx1 affects the development of the fourth pharyngeal arch arteries, whereas homozygous mutation severely disrupts the pharyngeal arch artery system. Our data show that haploinsufficiency of Tbx1 is sufficient to generate at least one important component of the DiGeorge syndrome phenotype in mice, and demonstrate the suitability of the mouse for the genetic dissection of microdeletion syndromes.

Establishment of variant PC12 subclones deficient in stimulation-secretion coupling

Clonal rat pheochromocytoma (PC12) cells have been widely used to study the molecular mechanism of exocytosis. We have isolated variant PC12 subclones with deficiencies in stimulation-secretion coupling, by a single cell recloning, and investigated the defects. PC12-1G2 hardly released dopamine following high-K(+)-induced depolarization, but normal release was evoked by the Ca(2+)-ionophore, ionomycin. Fura-2 fluorometry indicated that a nicardipine-sensitive component of Ca(2+) influx was missing, suggesting that PC12-1G2 has defects in L-type Ca(2+) channel function. PC12-2B3 was not responsive to high-K(+)-induced depolarization and ionomycin, and voltage-dependent Ca(2+) entry was identical to that of the normal clone. Electron microscopy revealed that the number of vesicles adjacent or directly attached to the plasma membrane was decreased in PC12-2B3. The expression of presynaptic proteins was analyzed by immunoblotting using a panel of antibodies. Syntaxin 1, VAMP-2, SNAP-25, Munc18, Rab3C and Sec-6 were decreased compared to the control clone and that of synaptophysin was extremely low. PC12-D60 synthesized and released dopamine normally, but had almost lost its catecholamine-uptake activity. These results show that multiple PC12 cells variants are spontaneously generated, and that recloning can select PC12 subclones useful for the study of the molecular mechanisms of neurotransmitter release.

[A case of lateral origin of the left internal mammary artery]

A 66 years old men, with left anterior descending coronary artery (LAD) stenosis and aortic valve stenosis, underwent coronary artery bypass grafting (CABG) to LAD with left internal mammary artery (LIMA) and aortic valve replacement. His postoperative course was uneventful. But, postoperative angiogram showed that his patent LIMA graft was originated from much lateral side of the left subclavian artery. Internal mammary artery is considered the most ideal graft for CABG, but its' anomality is not well known. We present this rare case with the anomalous origin of LIMA.

CROP/Luc7A, a novel serine/arginine-rich nuclear protein, isolated from cisplatin-resistant cell line

A novel putative SR protein, designated cisplatin resistance-associated overexpressed protein (CROP), has been cloned from cisplatin-resistant cell lines by differential display. The N-half of the deduced amino acid sequence of 432 amino acids of CROP contains cysteine/histidine motifs and leucine zipper-like repeats. The C-half consists mostly of charged and polar amino acids: arginine (58 residues or 25%), glutamate (36 residues or 16%), serine (35 residues or 15%), lysine (30 residues, 13%), and aspartate (20 residues or 9%). The C-half is extremely hydrophilic and comprises domains rich in lysine and glutamate residues, rich in alternating arginine and glutamate residues, and rich in arginine and serine residues. The arginine/serine-rich domain is dominated by a series of 8 amino acid imperfect repetitive motif (consensus sequence, Ser-Arg-Ser-Arg-Asp/Glu-Arg-Arg-Arg), which has been found in RNA splicing factors. The RNase protection assay and Western blotting analysis indicate that the expression of CROP is about 2-3-fold higher in mRNA and protein levels in cisplatin-resistant ACHN/CDDP cells than in host ACHN cells. CROP is the human homologue of yeast Luc7p, which is supposed to be involved in 5'-splice site recognition and is essential for vegetative growth.

The basic diagnostic approaches used in robotic still-image telepathology

We investigated the basic diagnostic processes used in telepathology with our robotic still-image system, OLMICOS, by analysing the steps and patterns used in 20 consecutive tissue section diagnoses. Three basic approaches were recognized. One was magnifying a suspect finding in a low-powered microscopic image. This approach was used mostly for confirming or characterizing a tumour. The second approach was scanning over a low-powered image by magnifying square images to form a mesh. This was found to be useful to confirm the presence or absence of signs and was mostly used as the initial step in judging the surgical margin of malignant cases or diagnosing lesions. The third approach was a combination of these two and was used for delineating the surgical margin, confirming the absence of metastases or diagnosing difficult lesions. Recognition of these three basic diagnostic approaches is important in making a rapid and correct remote diagnosis.

Elevated body fat in rats by the dietary nitric oxide synthase inhibitor, L-N omega nitroarginine

The influence of the dietary nitric oxide (NO) synthase inhibitor, L-N omega nitroarginine (L-NNA) on body fat was examined in rats. In experiment 1, all rats were fed with the same amount of diet with or without 0.02% L-NNA for 8 wk. L-NNA intake caused elevations in serum triglyceride and body fat, and reduction in serum nitrate (a metabolite of nitric oxide). The activity of hepatic carnitine palmitoyltransferase was reduced by L-NNA. In experiment 2, rats were fed for 8 wk with the same amount of diets with or without 0.02% L-NNA supplemented or not with 4% L-arginine. The elevation in body fat, and the reductions in serum nitrate and in the activity of hepatic carnitine palmitoyltransferase by L-NNA were all suppressed by supplemental L-arginine. The results suggest that lower NO generation elevated not only serum triglyceride, but also body fat by reduced fatty acid oxidation.

Developmental spectrum of cardiac outflow tract anomalies encompassing transposition of the great arteries and dextroposition of the aorta: pathogenic effect of extrinsic retinoic acid in the mouse embryo

We previously reported that retinoic acid shows a dose-dependent differential induction of various cardiac outflow anomalies: transposition of the great arteries is induced mainly by a high dose (70 mg/kg) and dextroposition of the aorta by a low dose (40-60 mg/kg; Yasui et al., 1995). We subsequently delineated the aberrant outflow tract septation process leading to the transposition (Yasui et al., 1997). The aim of the present study was to illustrate a spectrum of developmental abnormalities by examining mouse embryos treated with a low dose of retinoic acid and comparing them with embryos administered a high dose. We employed in situ observation on live embryos to discern the blood flow streams and scanning electron microscopy to clarify the internal structure. The embryos treated with a low dose of retinoic acid showed several basic phenotypes common to the high dose retinoic acid group, although variable and relatively mild, such as hypoplasia and dysplasia in the proximal outflow cushions, decreased counter-clockwise rotation in the distal outflow tract, and deviation of the edges of the developing outflow septum. In typical cases, the right-sided edge of the developing outflow septum shifted ventrally by various degrees, allowing for the right ventricle-to-aorta pathway, whereas the left-sided edge preserved the continuity with the interventricular septum, as in the normal embryo. These findings indicate that morphogenesis of dextroposition of the aorta and transposition of the great arteries are not only distinct but also show some basic pathways in common.

Situs variation and cardiovascular anomalies in the transgenic mouse insertional mutation, inv

The inv mouse was reported as a novel strain with situs inversus Yokoyama et al., '93), and a few cases with heterotaxy were found in homozygotes. The original report by Yokoyama et al. described the location of the heart and the stomach using the index of arrangement of body structure. We newly examined 40 homozygous offspring for phenotypes of visceroatrial situs and the incidence of cardiovascular anomalies making use of morphological details defined in each organ structure. According to the arrangement of each organ, which ranged from the almost complete form of situs inversus to left isomerism, visceroatrial situs was classified into four categories: Situs inversus (4 cases), "variation type" of situs (17 cases), "abdominal heterotaxy" (15 cases), and visceroatrial heterotaxy (4 cases). In offspring with situs inversus, only one had aortic stenosis (25%). Seven with the "variation type" of situs had cardiovascular anomalies, such as aortic stenosis, endocardial cushion defect, and posterior vena cava interruption (41%). All 15 offspring with "abdominal heterotaxy" had anomalies of the posterior vena cava, and three of them also had tetralogy of Fallot. The remaining four with visceroatrial heterotaxy had endocardial cushion defect, which was associated with outflow tract anomaly in two cases (i.e. tetralogy of Fallot in one case and transportation of the great arteries in the other). These results revealed that visceroatrial heterotaxy frequently occurred in the inv homozygotes, especially in the abdomen, and often showed a propensity to left isomerism with posterior vena cava interruption.

Dominant lethality of the mouse skeletal mutation tail-short (Ts) is determined by the Ts allele from mating partners

Mice with the Tail-short (Ts) mutation have a short, kinky tail and numerous skeletal abnormalities, including a homeotic anteroposterior patterning problem involving the axial skeleton. The viability of Ts heterozygotes varies dramatically, depending on the mouse strain crossed with the mutant strain. At the extremes, the heterozygotes are viable or lethal prenatally. In this study, we found that laboratory mouse strains could be divided into two groups. A cross with strains from the first group yielded viable Ts heterozygotes, whereas a cross with the second group resulted in dominant lethality in utero. We planned to map the gene(s) that controls strain differences in the viability of the Ts heterozygotes. The result clearly indicated that a single chromosomal region, genetically inseparable from the Ts locus, is responsible for these differences. This suggests that allelism at the Ts locus generates variable manifestation of the mutant phenotype. Morphological and histological analyses indicated that embryos from the lethal cross exhibit severe developmental defects from the gastrulation stage through the early fetal stage. In particular, the umbilical vein does not develop properly. All of these results suggest that the phenotype of the Ts mutant is modified by the Ts alleles of the mating partners.

Anomalous looping, atrioventricular cushion dysplasia, and unilateral ventricular hypoplasia in the mouse embryos with right isomerism induced by retinoic acid

BACKGROUND

Visceroatrial heterotaxy syndrome is characterized by abnormality of visceral laterality and complex cardiovascular anomalies usually involving both the outflow and inflow tract. Morishima et al. (1995) showed that mouse embryos treated with all-trans retinoic acid at embryonic day 6.5 (primitive streak stage) induces this syndrome.

METHODS

To investigate the morphogenetic process of visceroatrial heterotaxy syndrome, we examined retinoic acid-treated mouse embryos at embryonic days 9-15 using scanning electron microscopy.

RESULTS

The sinoatrial connection was first distinguished for the determination of situs as early as at embryonic day 10.5. Normal visceroatrial situs was found in 57% of all treated embryos, and the rest had abnormal situs, in which right isomerism was found in 81%. In the right-isomeric mouse, the cardiac morphology was characterized by abnormal looping together with dysplasia of the inflow and outflow tract cushion; that is, the primitive right ventricle was usually deviated cranially to various degrees, the atrioventricular cushion appeared trilobed in a half of them, and unilateral ventricular hypoplasia was noted in about one-third of them after embryonic day 14.5.

CONCLUSIONS

An anomalous relation between the atrioventricular cushions and the interventricular septum appeared to have caused a restrictive inflow to the unilateral ventricle, leading to ventricular chamber hypoplasia on the ipsilateral side. Thus, we clarified that retinoic-acid treatment at the primitive streak stage disturbed cardiac looping and formation of atrioventricular cushion development, which secondarily influenced ventricular chamber development.

Distribution of fibronectin, type I collagen, type IV collagen, and laminin in the cardiac jelly of the mouse embryonic heart with retinoic acid-induced complete transposition of the great arteries

BACKGROUND

In the mouse model of complete transposition of the great arteries (TGA) produced by all-trans retinoic acid (RA), parietal and septal ridges in the outflow tract (OT) are hypoplastic. At first, these ridges are generated by an expanded cardiac jelly (mainly myocardial basement membrane). Thereafter, endothelial cells delaminate and invade into the adjacent cardiac jelly to form endocardial cushion tissue (formation of cushion ridge). During cushion tissue formation, basement membrane antigens play an important role in the regulation of this endothelial-mesenchymal transformation.

METHODS

To examine whether the myocardial basement membrane components are altered in the RA-treated heart OT, immunohistochemistry for fibronectin, type I collagen, type IV collagen, and laminin was carried out in mouse embryonic hearts at 9.5 and 10.5 ED (embryonic day; vaginal plug = day 0) with or without prior exposure to RA.

RESULTS

Particulate/fibrillar fibronectin and fibrillar type I collagen were observed in the thick cardiac jelly of the control heart at the onset of mesenchymal formation. In the RA-treated heart, an intermittent patchy staining for fibronectin and a sparse distribution of type I collagen were observed in the thin cardiac jelly. Laminin and type IV collagen were distributed continuously on the basal surface (layer adjacent to the basal plasma membrane) of endocardium and myocardium in both control and RA-treated hearts.

CONCLUSIONS

The alterations in the antigens of the myocardial basement membrane (cardiac jelly) may be responsible for the hypoplasticity of parietal and septal ridges that characterizes RA-induced TGA morphology. This may be one of the reasons why mesenchymal cell formation is inhibited in the RA-induced TGA.

Amino acid substitutions in the first transmembrane domain (TM1) of P-glycoprotein that alter substrate specificity

Recently, we showed that the amino acid at position 61 in TM1 of human P-glycoprotein is important in deciding the substrate specificity of this protein. In this work, we investigated whether the amino acids other than His61 in TM1 of P-glycoprotein are also essential in the function of this protein. Nine amino acids residues, from Ala57 to Leu65 in TM1, were independently substituted to Arg, and analyzed the drug resistance of cells stably expressing each of these mutant P-glycoproteins. The mutant P-glycoproteins Ile60 --> Arg, His61 --> Arg, Ala63 --> Arg, Gly64 --> Arg, and Leu65 --> Arg were normally processed and expressed in the plasma membrane. Substrate specificities of mutant P-glycoproteins Gly64 --> Arg and Leu65 --> Arg were quite different from that of the wild type, and similar to that of the His61 --> Arg mutant, while the Ile60 --> Arg and Ala63 --> Arg mutant P-glycoproteins showed similar substrate specificities to that of the wild-type P-glycoprotein, suggesting that not only the amino acid residue at position 61 but also those at position 64 and 65 are also important in deciding the substrate specificity of P-glycoprotein. These three amino acids His61, Gly64, and Leu65 would form a compact region on an alpha-helix arrangement of TM1. These results suggest that a region consisting of His61, Gly64, and Leu65 in TM1 would participate in the formation of the recognition site for substrates of P-glycoprotein.

Alteration of substrate specificity by mutations at the His61 position in predicted transmembrane domain 1 of human MDR1/P-glycoprotein

In CFTR, a member of the ABC superfamily and a chloride channel, amino acid substitutions in its transmembrane domains 1 and 6 (TM1, TM6) have been reported to modulate the anion selectivity or ion conductance of the ion channel. In P-glycoprotein, no amino acid substitution in TM1, but some in TM6, have been reported to modify the substrate specificity of this protein. In this work, we demonstrated the involvement of His61, which is in the middle of the predicted TM1, in the function of P-glycoprotein. His61 was replaced by all other amino acid residues, and each of the mutant cDNAs was introduced into drug-sensitive human carcinoma cells, KB3-1. The drug-resistance profile of cells stably expressing each mutated P-glycoprotein was investigated by comparing their relative resistance to vinblastine, colchicine, VP16, and adriamycin. The resistance to vinblastine was increased by replacing His61 by amino acids with smaller side chains, while it was lowered by replacing by amino acids with bulkier side chains. The reverse effect was observed for resistance to colchicine and VP16. The resistance to adriamycin was increased by replacing by amino acids with bulkier side chains except Lys or Arg, which have a basic side chain. We also showed that the replacement of His61 by Phe and Lys greatly impaired the efflux of calcein AM, while the replacement had no effect on the efflux of rhodamine 123. These results suggest that an amino acid residue at position 61 in TM1 is important in deciding the substrate specificity of P-glycoprotein.

Cardiac outflow tract septation process in the mouse model of transposition of the great arteries

It has been reported that all-trans retinoic acid induces transposition of the great arteries (TGA) at 80-90% in ICR mice. The authors revealed that retinoic acid affects the initial formation of the conus cushions leading to a loss of spirality in the cardiac outflow tract. However, the aberrant process of septation has not been precisely defined. In this study, we observed the hearts of live embryos using a video system followed by scanning electron microscopic examination. First, we found that, in the retinoic acid-treated embryos, the proximal outflow tract cushions, in addition to hypoplasia and dysplasia, did not establish the continuity with the distal outflow tract cushions and could not contribute to the outflow septation. Second, the distal outflow tract did not rotate counter-clockwise, retaining the outflow septum anlage in the superoinferior position. Third, a tongue-like mesenchymal tissue had developed on the right anterior rim of the muscular interventricular septum and was incorporated into the interventricular septum. Altogether, these processes contributed to establishing a reversed relationship between the outflow septum anlage and the ventricular septum anlage. On the other hand, right-ward deviation of one or both of the distal outflow tract cushions, relative to the mesenchymal tissue, gave rise to variable degrees of overriding of the pulmonary artery orifice. We conclude that, due to hypoplasia and dysplasia of the proximal outflow tract cushions and lack of distal outflow tract rotation, the outflow septum anlage took an inverted relationship with the ventricular septum anlage. Various types of rightward shift of the outflow tract cushions produced a morphological spectrum of TGA-type cono-truncal anomalies.

How does P-glycoprotein recognize its substrates?

We review how P-glycoprotein recognizes a wide variety of compounds and how it carries its substrates across membranes. Amino acid substitutions that affect the substrate specificity of P-glycoprotein have been found scattered throughout the molecule. In particular, some amino acid residues in the putative transmembrane domain (TM) 1 together with TM5-6 and TM11-12 may help to govern substrate specificity. The features that substrates for P-glycoprotein share are also discussed. The amphipathy of a substrate may decide whether the substrate can be intercalated into the lipid bilayer of the membrane. In addition, only certain molecular volumes and tertiary structures may make it possible for the substrate to fit into the substrate-binding site(s) of P-glycoprotein.

Altered distribution of collagen type I and hyaluronic acid in the cardiac outflow tract of mouse embryos destined to develop transposition of the great arteries

Complete transposition of the great arteries (TGA) is inducible by treatment with all-trans retinoic acid in the ICR mouse. In this model, hypoplasia and dysplasia of the proximal outflow tract cushion tissue lead to non-spiral septation. In order to evaluate the effect of retinoic acid on the extracellular matrix of the cardiac outflow tract, we examined the distribution of collagen type I and hyaluronic acid, immunohistochemically, on days 8-9 of gestation. In controls, collagen type I fibrils ran mainly in a radial direction, extending towards the endocardium in the cardiac jelly of the proximal outflow tract. Also, a pair of longitudinal fiber bundles were formed stretching to the distal outflow tract. As for hyaluronic acid, intense staining was observed in the submyocardial and intermyocardial space of the outer curvature of the heart. On the other hand, in retinoic acid-treated embryos, the submyocardial radial fibrils or longitudinal fiber bundles of collagen type I were diminished, and irregular and dense deposits of collagen type I were observed along the endocardium. Furthermore, hyaluronic acid showed a loss of differential localization between the outer and inner curvature. Instead, irregular and intense staining was observed uniformly along the outflow myocardium. Thus, retinoic acid appeared to have perturbed the differentiation in the proximal outflow tract causing an altered organization of multiple extracellular matrix molecules, including collagen type I and hyaluronic acid, which led to an abnormal molecular network of the cardiac jelly in the cardiac outflow tract, abnormal septation and, further, to TGA or TGA-type anomalies.

Influence of genetic and maternal diabetes in the pathogenesis of visceroatrial heterotaxy in mice

The NOD mouse is known as a spontaneous model of insulin-dependent diabetes mellitus. Fetuses in this strain present anomalies of the viscera, and the incidence increases in fetuses from dams with clinically manifested diabetes. To examine the role of maternal diabetes and the genetical influence in inducing heterotaxy, NOD dams were mated with males of the ICR strain (the original strain of the NOD) and with C57BL/6J sires (not genetically related to the NOD). The frequency of visceroatrial heterotaxy in fetuses from diabetic dams varied with the fetal genotype, being 65% (33/51) in NODxNOD (dam X sire, respectively), 24% (12/50) in NODxICR, and 7% (4/57) in NODxC57BL/6J. The cases with heterotaxy showed a tendency toward right isomerism of the viscera and had severe cardiac defects, such as endocardial cushion defect and double-outlet right ventricle or transposition of the great arteries. The fetal body weight from diabetic dams in each mating was lower than that from non-diabetic dams (P < 0.05), suggesting that maternal diabetes, rather than abnormal situs, is the main determinant for decreased fetal growth. These findings demonstrate that the liability to heterotaxy induced by maternal diabetes is influenced by the fetal genotype.

Pathological study of Japanese quail embryo with acid alpha-glucosidase deficiency during early development

A pathological study was performed on the tissues of 11 Japanese quail embryos with type II glycogen storage disease (GSD II) between incubation day (ID) 3 and ID 15. Accumulation of glycogen in vacuoles derived from lysosomes was first seen in cardiac muscle at ID 3, in liver at ID 5, in wing muscle at ID 7, and in pectoral muscle at ID 10. The number and size of the glycogen vacuoles gradually increased during development, especially in cardiac muscle. Cytoplasmic glycogen particles, showing the same density as membrane-enclosed glycogen particles, were first seen as masses in cardiac muscle at ID 3, in liver at ID 5, in pectoral muscle at ID 10, and in wing muscle at ID 15. The area of cytoplasm occupied by the glycogen particles increased during development. Myofibrillar degeneration was not seen, although myofibrils appeared in disarray in the early stages, as in normal embryos. This is the first study of the development of embryonic tissues of Japanese quails with GSD II. GSD II in the Japanese quail appears to be clinically analogous to the human late (juvenile)-onset disease, although the disorder starts at very early stages in quail embryos. Therefore, Japanese quails with GSD II can provide a model for elucidating the pathogenetic process of human GSD II.

Hypoplasia of cushion ridges in the proximal outflow tract elicits formation of a right ventricle-to-aortic route in retinoic acid-induced complete transposition of the great arteries in the mouse: scanning electron microscopic observations of corrosion cast models

BACKGROUND

The major morphologic change associated with retinoic acid (RA)-induced complete transposition of the great arteries (TGA), a congenital malformation of the heart, was investigated in a mouse model in which TGA was found in 80% of surviving fetuses.

METHODS

Corrosion casts of embryonic hearts with or without prior exposure to retinoic acid were observed under a scanning electron microscope.

RESULTS

In control hearts, indentations caused by expanded parietal and septal ridges in the outflow tract established right ventricle-to-left ventral pulmonic and left ventricle-to-right dorsal aortic routes before the aorticopulmonary septum completion. In RA-treated hearts, indentations of proximal regions of the parietal and septal ridges were small in the proximal outflow tract, whereas those in the distal regions developed well. These morphological features in the RA-treated hearts elicited right ventricle-to-right ventral aortic and left ventricle-to-left dorsal pulmonic routes in the TGA morphology.

CONCLUSIONS

Hypoplasticity of the proximal regions of parietal and septal ridges in the outflow tract is one of the primary morphological abnormalities of the RA-induced TGA.

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.

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.

Hemodynamics and ventricular function in the day-12 rat embryo: basic characteristics and the responses to cardiovascular drugs

We investigated the basic characteristics of the rat embryonic circulation and also looked at the hemodynamic effects of alpha- and beta-agonists, digitalis, and atrial natriuretic peptide, using a modified organ culture system in which the embryo was placed in oxygenated Hanks' balanced salt solution, blood pressure was measured by a servo-null micropressure system, and blood flow pattern was obtained by a 20-MHz pulsed Doppler velocity meter. The peak pressure was 0.5 +/- 0.04 (SEM) mm Hg at the atrium (n = 6), 2.3 +/- 0.10 mm Hg at the ventricle (n = 15), 1.6 +/- 0.03 mm Hg at the truncus (n = 7), and 1.0 +/- 0.05 mm Hg at the umbilical artery (n = 21). There was a pressure drop from the ventricle to the truncus and then a smaller pressure decrease to the umbilical artery. The atrial a-wave was 20% of ventricular pressure and ventricular inflow blood flow pattern showed very low early-to-late filling ratio, indicating that the ventricle was stiff. These findings were essentially the same as in the chick embryo. We recorded the ventricular image by using a high-speed video system with a frame rate of 200/s, and the ventricular pressure-area loop showed a triangular shape with short isovolumetric phases, which was different from that of the chick embryo at a similar stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Posttranslational modifications of tau in paired helical filaments

Paired helical filaments (PHF) are fibrillar structures that accumulate in degenerating neurons of AD brain. We have purified their components, PHF-tau and PHF-smear, and analyzed them protein chemically. PHF-tau is abnormally phosphorylated. Although the characteristic of this phosphorylation is similar to that of fetal tau, its extent is higher in PHF-tau. The additional phosphorylation in PHF-tau may cause its loss of microtubule assembly capacity. Our results on the phosphorylation sites suggested that fetal tau and presumably PHF-tau are in vivo substrates of proline-directed protein kinases. PHF-smear consisted largely of the carboxyl-terminal portion of tau and ubiquitin. The ubiquitin-targeted protein was identified as tau in PHF and the conjugation sites were localized to the microtubule-binding region. It is most likely that abnormally phosphorylated full-length tau (PHF-tau) accumulates as PHF, which is then gradually processed from its amino-terminus and followed by ubiquitination.

Effects of environmental hyperthermia on cardiovascular function in the rat embryo

Effects of hyperthermia on the cardiovascular function of the mammalian embryo have not been well defined. The effect of hyperthermia on the blood flow and umbilical artery blood pressure was studied in rat embryos at gestational d 12 by using a method developed in our laboratory. When the temperature was changed from 37 to 42 degrees C, the heart rate increased by 15% (n = 33). Mean umbilical artery blood pressure, measured by a servo-null micropressure system, decreased from 0.64 +/- 0.05 to 0.53 +/- 0.04 mm Hg (n = 11), whereas blood flow velocity at the conotruncus, a measure of cardiac output, obtained by a 20-MHz pulsed Doppler ultrasound flowmeter, increased by 36 +/- 11% (n = 11). Mean umbilical artery blood flow increased by 66 +/- 13% (n = 11) and its vascular resistance, calculated by ratio analysis, decreased from 3.7 (median) to 1.8 units. These changes returned to baseline values when the temperature was returned to 37 degrees C. The change in blood pressure was different from that seen in the chick embryo, indicating that there is species difference in the hemodynamic effect.

Visceroatrial heterotaxy syndrome in the NOD mouse with special reference to atrial situs

Following the onset of diabetes mellitus (DM) in the NOD mouse, diabetic dams have many offspring with severe anomalies, especially with visceroatrial heterotaxy syndrome. The purpose of the present study is to analyze this syndrome with special reference to atrial situs. The fetuses from a colony of NOD mice in our laboratory were divided into two study groups: Group A included fetuses from dams before the onset of DM and group B included fetuses from dams with overt DM before day 8 of pregnancy. The fetuses which had cardiac anomalies with viscero-atrial heterotaxy were classified into four subtypes according to the atrial morphology, i.e., "incomplete situs solitus" (or solitus-like), "incomplete situs inversus" (inversus-like), right isomerism, and left isomerism. Group A (671 fetuses) included only one case with right isomerism (0.15%) and four cases with left isomerism (0.6%). Group B (158 fetuses) had 57 fetuses with heterotaxy syndrome (36.1%), including 20 cases with solitus-like, 6 with inversus-like, 30 with right isomerism, and one with left isomerism. A tendency for right isomerism to occur was found in fetuses with solitus-like and inversus-like anomalies. These results show that the maternal DM in this mouse had an influence upon the morphological mechanism determining right isomerism of visceroatrial heterotaxy syndrome. Thus this syndrome in the NOD mouse is equivalent to asplenia in humans, and it may be useful in elucidating the mechanism of the human syndrome.

Neointima formation on an antithrombogenic cardiac wall substitute that can be reconstructed by host cells

The authors previously reported on a new cardiac wall substitute (collagen-coated ultrafine polyester mesh, CUFP), which in an animal study showed satisfactory antithrombogenicity due to its hydrophilicity and excellent neointimal formation because it induced cell migration and proliferation. Both the ultrafine polyester mesh, and the collagen cross-linked with a hydrophilic reagent, have a special affinity for host cells. In the current study, the focus was on neointima formation on the CUFP, compared with that on glutaraldehyde-treated equine pericardium (GA graft), over longer time periods. Twenty-one CUFPs, and 19 GA grafts as controls, were implanted as patches in the right ventricular outflow tract in 40 dogs. In the CUFP at 28 days, a thin neointima, which was almost endothelialized, had been formed. Fibroblasts and vasa vasorum were seen inside both the neointima and the graft wall. The CUFP showed a white, shiny, smooth, thin, and uniform neointima with endothilialization at 486 days, and the neointima was firmly anchored by day 699. In the GA graft at 484 days, however, the neointima was partly detached from the GA graft and almost no fibroblasts had infiltrated the graft wall. Therefore, neointimal formation on the CUFP is almost completed within 1 month and maintained over the long term.

A new bioprosthetic cardiac valve with reduced calcification

A bioprosthetic cardiac valve cross-linked with a glycerol polyglycidyl ether polyepoxy compound (PC) was developed in order to reduce calcification and degeneration, which often occurs in bioprosthetic cardiac valves. Aortic valves harvested from dogs were treated with PC (PC valve). Right ventricle (RV)-pulmonary artery (PA) bypasses were placed in 12 dogs with PC-valved conduits, and the main PA was ligated. X-ray right ventriculography at 36 days (1 dog) and 37 days (1 dog) revealed an excellent open/close performance of the PC valve, and there was no visible thrombus in the valve. In our basic study, PC treated collagen gel disks implanted in the subcutaneous layer of growing rats showed remarkably less calcium deposition than did those treated with glutaraldehyde (GA). Biologic materials cross-linked with PC maintain their pliability, and become more hydrophilic and more hydrated than those cross-linked with GA. The hydrophilicity and hydration provide sufficient antithrombogenicity and a suitable environment for metabolism in the tissue fluid which contains oxygen, nutritive substances, and electrolytes, leading to inhibition of material degeneration. Therefore, PC valves are expected to show good valve function, sufficient antithrombogenicity, and excellent durability with less calcification, when compared to GA treated valves.

Long-term results of a new antithrombogenic cardiac wall substitute

We evaluated the long-term results of a new antithrombogenic cardiac wall substitute which is composed of collagen-coated ultrafine polyester mesh cross-linked by a hydrophilic polyepoxy compound (CUFP), and compared it with glutaraldehyde-treated equine pericardium (GA graft). In an animal study, 20 CUFPs and 18 GA control grafts were implanted as patches in the right ventricular outflow tract in 38 dogs. In the CUFP at 28 days after implantation, a thin neointima, which was almost endothelialized, had been formed. Fibroblasts and vasa vasorum were seen inside both the neointima and the graft wall. At 168 days, transmission electron microscopy revealed smooth muscle-like cells in the neointima, with endothelialization. The CUFP at 486 days had maintained a white, shiny, smooth, thin, and uniform neointima with endothelialization. Neither ulcer nor thrombus formation was seen on the surface, while in the GA graft at 353 days, no endothelialization was noticed in the center and almost no fibroblasts had infiltrated into the graft wall. From these results, the CUFP should be an ideal candidate for cardiac wall substitution.

Development of an antithrombogenic cardiac wall substitute which can be reconstructed by infiltration of host cells

Various kinds of materials, such as glutaraldehyde-treated pericardial heterografts, have been used as a cardiac wall substitute. Some problems were encountered with their use. We clarified these problems in animal experiments and developed a new cardiac wall substitute to overcome them. As one of the best cardiac wall substitutes obtainable at present, glutaraldehyde-treated equine pericardium (Xenomedica, GA-graft), was sutured as a patch in the right ventricular outflow tract (Group 1: 16 dogs). A new cardiac wall substitute, which is composed of collagen-coated polyester mesh (CUFP), was sutured in the same fashion (Group 2: 19 dogs). The problems clarified in the GA graft were insufficient antithrombogenicity and poor healing of the neointima and the graft wall. The CUFP had sufficient antithrombogenicity and good healing quality as a cardiac wall substitute. CUFP should be rapidly infiltrated by host cells, to become a kind of host organ and therefore not degenerate with long-term use.

[Correlation of LH and prolactin pulses in normoprolactinemic women with ovulatory disturbances and variation of LH and FSH pulses and secreting capacity by administration of bromocriptine in the same cases]

The difference between prolactin (PRL) basal levels on separate days in the 6 normoprolactinemic women--one case with an anovular cycle and 5 cases with 1 degree amenorrhea--among 14 normoprolactinemic women with ovulatory disturbances, showed significantly variation over 13 ng/ml within the normal range of the PRL basal level. PRL pulse frequencies of the same cases from 0900 h. to 1400 h. increased slightly compared with follicular phase. At the same time, the PRL pulse amplitudes were significantly higher than in the follicular phase but significantly lower than the PRL pulse amplitudes in hyperprolactinemic women. The net increase in PRL to TRH in the 6 cases was over 100 ng/ml. When the PRL net increase to TRH was over 100 ng/ml in normoprolactinemic women with ovulatory disturbances, the case is regarded as latent hyperprolactinemia. And 1 or 2 may be latent hyperprolactinemic syndrome. The LH/FSH basal level and delta LH/delta FSH to LH-RH before administration of bromocriptine increased in these cases compared with the follicular phase. During the administration of bromocriptine, the ratios decreased and approached the ratio in the follicular phase. The effect of clomid was improved by increased E2 in these cases.