New strategy for the antifibrotic therapy with oral administration of FR260330 (a selective inducible nitric oxide synthase inhibitor) in rat experimental liver cirrhosis

Inducible nitric oxide synthase (iNOS) activity is significantly elevated in viral hepatitis, alcoholic cirrhosis, and cholestasis. However, there are few reports on the relationship between iNOS and cirrhosis. Here, we investigated the effects of a new iNOS inhibitor that has been developed for oral administration in an experimental rat liver cirrhosis model. A cirrhotic rat model was developed by long-term administration of thioacetamide injections. FR260330 is a new, rationally designed, selective iNOS inhibitor that can be administered orally. After 12 weeks of treatment with FR260330, the rats showed inhibition of progressions of cirrhosis, ascites, and splenomegaly as well as a significant reduction in the proportions of connective tissue in the liver. The expression of nitrotyrosine, which indicates the existence of peroxynitrite and nuclear factor-kappaB activation, was remarkably decreased in the FR260330 treatment group. In addition, immunohistochemical and Western blot analyses showed that the expression of transforming growth factor-beta1 was remarkably decreased in this group. The present study demonstrates that FR260330 reduces liver fibrosis by the inhibition of transforming growth factor-beta1 and retards the development of cirrhosis. This oral iNOS inhibitor will be a new strategy for the treatment of cirrhosis.

Focal adhesion kinase mediates human leukocyte histocompatibility antigen class II-induced signaling in gingival fibroblasts

BACKGROUND AND OBJECTIVE

The role of human leukocyte antigen class II molecules on nonantigen-presenting cells has been a matter of controversy. We previously reported that human leukocyte antigen class II molecules on human gingival fibroblasts do not present antigens, but transduce signals into the cells by making a complex with antigenic peptide T-cell receptor or by stimulating cell surface human leukocyte antigen-DR molecules with human leukocyte antigen-DR antibody (L243), which mimics the formation of the human leukocyte antigen class II-antigenic peptide T-cell receptor complex, resulting in the expression of several cytokines. The aim of this study was to detect human leukocyte antigen class II-associated molecules mediating human leukocyte antigen class II-induced signals into the cells.

MATERIAL AND METHODS

Antibody-based protein-microarray analysis was performed to detect activated signaling molecules in gingival fibroblasts stimulated via human leukocyte antigen class II molecules. Then, we examined if these molecules structurally associate with human leukocyte antigen class II and actually transduce signals into the cells.

RESULTS

Stimulation of human leukocyte antigen class II on gingival fibroblasts by L243 resulted in enhanced phosphorylation of focal adhesion kinase. Focal adhesion kinase was co-immunoprecipitated with human leukocyte antigen-DR by L243. Stimulation of gingival fibroblasts with L243 induced phosphorylation of focal adhesion kinase. Luteolin, a putative focal adhesion kinase inhibitor, suppressed phosphorylation of focal adhesion kinase and dose dependently inhibited human leukocyte antigen class II-induced cytokine production.

CONCLUSION

Focal adhesion kinase is structurally associated with human leukocyte antigen-DR and mediates human leukocyte antigen class II-induced signals in gingival fibroblasts.

Behavioral and psychological symptoms assessed with the BEHAVE-AD-FW are differentially associated with cognitive dysfunction in Alzheimer’s disease

To assess the possible neurological basis of behavioral and psychological symptoms of dementia (BPSD), the relationships between BPSD and cognitive function were evaluated in 40 patients with Alzheimer's disease (AD). BPSD was assessed using the Behavioral Pathology in Alzheimer's Disease Frequency Weighted Severity Scale (BEHAVE-AD-FW) for behavioral symptoms and psychological symptoms separately, and cognitive function was also assessed using the Cognitive Abilities Screening Instrument (CASI). We found that only behavioral symptoms were associated with cognitive function based on the CASI total score and the score for the CASI attention domain. Administration of risperidone, an atypical anti-psychotic drug, for one month, improved the behavioral symptoms and the scores for the CASI attention and orientation domains. Our data suggest that BPSD in AD may reflect two largely independent pathophysiological processes: one associated with behavioral symptoms partly overlapping with attention, and the other associated with psychological symptoms predominantly unrelated to cognitive function.

Assessment of Nutritional Status and Prediction of Postoperative Liver Function from Serum Apolioprotein A-1 Levels with Hepatectomy

BACKGROUND

We investigated the usefulness of apolipoprotein A-1 (apoA) as an indicator of nutritional status, and the correlation of the preoperative apoA level with changes in postoperative liver function following hepatectomy.

METHODS

One hundred patients underwent hepatectomy. Serum levels of apoA, prealbumin (prealb), retinol-binding protein (RBP), lectin-cholesterol acyltransferase (LCAT), hyarulonate (HA), indocyanine green dye retention at 15 minutes (ICG), and the receptor index of Tc-GSA scintigraphy (LHL15) were measured at preoperation and on postoperative days (POD) 7 and 14. Partial resection was carried out in 62 cases, segmentectomy in nine cases, and bisegmentectomy in 29 cases. Co-existent liver conditions were normal liver (NL) in 43 cases, chronic hepatitis (CH) in 29 cases, and liver cirrhosis (LC) in 28 cases.

RESULTS

In most cases the serum apoA level had decreased on POD 7, and recovered on POD 14. There were no significant differences in the changes of apoA between the individual operative procedures. Although preoperative apoA had almost the same value in the NL, CH, and LC cases, apoA in LC cases on POD 14 was the lowest of all cases. The apoA level showed significant correlations with prealb, LCAT, and HA on POD 14. All cases were divided into two groups (group N: apoA over 91 mg/dl; group L: apoA under 90 mg/dl) based on the preoperative serum apoA level. On POD 14, the ICG, LHL15, and HA of group L were significantly deteriorated compared with those of group L.

CONCLUSION

The serum level of apoA reflects the changes in hepatic protein synthetic ability after hepatectomy; therefore, it may be possible to estimate recovery of nutritional status after hepatectomy from serum apoA. Moreover, we can predict postoperative deterioration of liver function from the preoperative apoA level.

The Functional Integrity of a Normothermic Perfusion System Using Artificial Blood in Pig Liver

BACKGROUND

We have reported already that we succeeded in developing a normothermic liver perfusion system consisting of purely artificial products such as artificial blood. The aim of this study was to ascertain the metabolic functional integrity of the liver perfused in this system.

MATERIALS AND METHODS

A liver graft from a female pig weighing 20 kg was harvested in the usual manner. The perfusion solution consisted of artificial blood, L-15 medium, distilled water, bovine serum albumin, NaHCO3, NaOH, KCl, human regular insulin, 50% glucose solution, and dexamethasone. The isolated liver was perfused with this oxygenated perfusate through the portal vein at a rate of 300 ml/min for 9 h. We analyzed the changes of amino acids, ammonia, and urea concentrations in five livers, which showed high oxygen consumption (over 8 ml-O2/min during perfusion).

RESULTS

Although urea did not exist in the perfusate at first, an extremely high level of the urea concentration appeared during the perfusion. On the other hand, the ammonia concentration was only slightly elevated during the perfusion. Arginine vanished from the perfusate with increases of citrulline and ornithine. Taurine was elevated with the disappearance of methionine. Alanine, glutamine, serine, histidine, and threonine concentrations decreased with an increase of the glucose concentration. Numerous liver cells exhibited PAS-positive cytoplasmic glycogen deposits not exhibited before perfusion. The ratios of branched-chain amino acids/aromatic amino acids were elevated during the perfusion.

CONCLUSION

Normothermic liver perfusion using artificial blood could sufficiently maintain the functional integrity of the liver.

An intestinal volvulus caused by multiple magnet ingestion: an unexpected risk in children

It has been reported that ingested magnets can cause intestinal fistula formation or perforation, leading to intestinal obstruction. However, there are no previous case reports that magnet ingestion additionally caused an intestinal volvulus. We report herein the case of a 1-year-old boy in whom the ingested magnets caused a volvulus of part of the small intestine leading to the resection of the necrotic portion. We think that if more than one magnet is found as a foreign body in the intestine, they should be removed immediately by laparotomy. Clinicians who care for children should be aware of this unexpected risk.

Remnant liver injury after hepatectomy with the pringle maneuver and its inhibition by an iNOS inhibitor (ONO-1714) in a pig model

BACKGROUND

Although hepatectomy is often performed with the Pringle maneuver, the problem of remnant liver injury is not fully solved. We examined the remnant liver injury of hepatectomy under the Pringle maneuver and its relation to inducible nitric oxide synthase (iNOS) in a pig hepatectomy model.

MATERIALS AND METHODS

Pigs were subjected to a total of eight Pringle maneuvers followed by re-perfusion. The pigs were divided into the following three groups: Control group; only Pringle maneuver, liver resection (LR) group; hepatectomy under the Pringle maneuver, and ONO group; and hepatectomy under the Pringle maneuver with an iNOS inhibitor (ONO-1714). We investigated the changes in serum aminotransferase (AST), lactate dehydrogenase (LDH), NO(2)(-)+NO(3)(-) (NOx), the hepatic tissue blood flow (HTBF), the cellular distribution of endothelial and inducible nitric oxide synthase, nitrotyrosine, infiltration of neutrophils, and thrombocyte-thrombi by immunohistochemistry.

RESULTS

The serum AST, LDH, NOx levels in the LR group were significantly higher than those in the Control group. The formation of iNOS, nitrotyrosine, thrombocyte-thrombi, and infiltration of neutrophils were recognized in the LR group. These findings were inhibited in the ONO group.

CONCLUSIONS

These results indicate that remnant liver injury appeared after hepatectomy with the Pringle maneuver. iNOS was involved in these injuries and the iNOS inhibitor attenuated the injury.

Septic thrombophlebitis of the portal and superior mesenteric veins as a complication of appendicitis: report of a case

Pylephlebitis is extremely rare and associated with high mortality, even in this modern era. It usually occurs secondary to infection in the region drained by the portal systems or in the structure contiguous to the portal vein. We report a case of septic thrombophlebitis of the portal and superior mesenteric veins (SMV) with multiple liver abscesses caused by acute appendicitis with an abscess of the mesoappendix. We performed appendectomy and successfully removed the thrombi using a Fogarty catheter. Postoperative histopathological examination confirmed a diagnosis of appendicitis and septic thrombophlebitis of the portal vein and SMV. The patient recovered completely with appropriate medical and surgical treatment.

Role of inducible nitric oxide synthase in pig liver transplantation

BACKGROUND

Previously, we clarified the role of inducible nitric oxide synthase (iNOS) and the protective effect of an iNOS inhibitor in warm ischemia and reperfusion model. In this study, we investigated whether the same effects would be obtained by iNOS inhibitor in liver transplantation model.

MATERIAL AND METHODS

Orthotopic liver transplantation was performed in pigs in the usual manner after about 6 h of cold preservation in University of Wisconsin solution. Aminoguanidine hemisulfate (AG) was used as the iNOS inhibitor and AG was administered intraportally at the dose of 10 mg/kg just after reperfusion. Two experimental groups were subjected, control group (n = 10), and AG group (n = 10). We investigated changes of serum nitrite/nitrate (NOx) and aspartate aminotransferase (AST). Expression of iNOS was examined by immunohistochemistry, including a double immunofluorescnce technique in combination with cofocal laser scanning microscopy.

RESULTS

Serum NOx and AST were significantly lower in the AG group. Histological hepatic damage and thrombocyte thrombi were attenuated in the AG group. Expression of iNOS was recognized strongly at Kupffer cells and neutrophils in the centrilobular region of liver after reperfusion by cofocal laser scanning microscopy. Moreover, iNOS staining was attenuated in AG group compared with control group.

CONCLUSIONS

These results indicate that hepatic ischemia and reperfusion injury in liver transplantation might be triggered by iNOS expression of Kupffer cells and neutrophils, and attenuated by administration of an iNOS inhibitor. Moreover, AG showed down regulation of iNOS expression after reperfusion.

Role of inducible nitric oxide synthase in pig liver transplantation

BACKGROUND

Previously, we clarified the role of inducible nitric oxide synthase (iNOS) and the protective effect of an iNOS inhibitor in warm ischemia and reperfusion model. In this study, we investigated whether the same effects would be obtained by iNOS inhibitor in liver transplantation model.

MATERIAL AND METHODS

Orthotopic liver transplantation was performed in pigs in the usual manner after about 6 h of cold preservation in University of Wisconsin solution. Aminoguanidine hemisulfate (AG) was used as the iNOS inhibitor and AG was administered intraportally at the dose of 10 mg/kg just after reperfusion. Two experimental groups were subjected, control group (n = 10), and AG group (n = 10). We investigated changes of serum nitrite/nitrate (NOx) and aspartate aminotransferase (AST). Expression of iNOS was examined by immunohistochemistry, including a double immunofluorescnce technique in combination with cofocal laser scanning microscopy.

RESULTS

Serum NOx and AST were significantly lower in the AG group. Histological hepatic damage and thrombocyte thrombi were attenuated in the AG group. Expression of iNOS was recognized strongly at Kupffer cells and neutrophils in the centrilobular region of liver after reperfusion by cofocal laser scanning microscopy. Moreover, iNOS staining was attenuated in AG group compared with control group.

CONCLUSIONS

These results indicate that hepatic ischemia and reperfusion injury in liver transplantation might be triggered by iNOS expression of Kupffer cells and neutrophils, and attenuated by administration of an iNOS inhibitor. Moreover, AG showed down regulation of iNOS expression after reperfusion.

Apoptosis and necrosis after warm ischemia-reperfusion injury of the pig liver and their inhibition by ONO-1714

BACKGROUND

It is still controversial whether a major mode of cell death during hepatic ischemia-reperfusion (I/R) injuries is apoptosis or necrosis. Moreover, the correlation between these cell deaths and the effects of a novel inducible nitric oxide synthase inhibitor (ONO-1714) has not been studied before.

METHODS

Pigs were subjected to 180 min of hepatic warm I/R under extracorporeal circulation. The control group was not administered ONO-1714. In the ONO-1714 group, ONO-1714 was administered 5 min before ischemia at a dose of 0.05 mg/kg through a portal vein catheter. The apoptotic and necrotic changes after reperfusion were examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and hematoxylin-eosin staining. Nitrotyrosine, active caspase-3, and cytochrome c were examined by immunohistochemistry. The plasma NO + NO, aspartate aminotransferase, and lactate dehydrogenase levels were also examined.

RESULTS

In the control group, the frequency of apoptotic cells was only 2.6%; nevertheless, that of necrotic cells was 37% at 24 hr after reperfusion. ONO-1714 significantly attenuated apoptosis and necrosis, the expression of nitrotyrosine, and the increases of the plasma aspartate aminotransferase, lactate dehydrogenase, and NO(2)- + NO(3)- levels in the reperfusion phase.

CONCLUSIONS

A major mode of cell death during hepatic warm I/R injury was necrosis, and apoptosis was not dominant. These necrotic changes were caused by the excess production of peroxynitrite, and ONO-1714 greatly attenuated I/R injuries as the result of inhibition of the peroxynitrite production.

Preoperative estimation of risk in hepatectomy using technetium-99m-galactosyl human serum albumin receptor amount by nonlinear 3-compartment model

BACKGROUND/AIMS

Recently, we developed the method for measurement of the technetium-99m-diethylenetriamine-pentaacetic acid-galactosyl human serum albumin (Tc-GSA) receptor amount (R0) using a nonlinear 3-compartment model. We examined the usefulness of R0 for preoperative estimation of risk in hepatectomy.

METHODOLOGY

Sixty-three patients who underwent hepatectomy in our hospital were examined for R0. These patients consisted of 26 cases of normal liver, 16 cases of liver fibrosis, and 21 cases of cirrhosis. R0 was measured by the nonlinear 3-compartment model of ligand-receptor binding without blood sampling in Tc-GSA scintigraphy. The expected remnant liver R0 after hepatectomy was calculated from CT volumetry before hepatectomy.

RESULTS

The preoperative mean R0 of liver was 15.8 +/- 3.8 mg for Z0, 13.8 +/- 3.9 mg for Z1, and 6.9 +/- 2.3 mg for Z2. R0 in Z2 was significantly lower than Z0 and Z1 (p < 0.0001). Every patient whose remnant liver R0 was over 5 mg tolerated hepatectomy without any postoperative complications. Among 63 cases, 5 patients developed postoperative complications (two liver failures, two postoperative jaundice and one hepatic coma), and remnant liver R0 of these patients were under 5 mg.

CONCLUSIONS

From these results, it can be seen that R0 of remnant liver is a useful parameter to decide indication of hepatectomy and predict postoperative complications.

Successful ex vivo normothermic liver perfusion with purely artificial products using artificial blood

We tried to make an ex vivo functioning liver with an artificial perfusate that consisted of artificial blood in the pig liver. A liver graft from a female pig weighing 20 kg was harvested in the usual manner. The perfusion solution consisted of artificial blood, L-15 medium, distilled water, bovine serum albumin, NaHCO3, NaOH, KCl, human regular insulin, 50% glucose solution, and dexamethasone. The isolated liver was perfused with this oxygenated perfusate through the portal vein at a rate of 300 ml/min for 9 hours. Seven livers were perfused for 9 hours in this system. Five of the livers showed mean oxygen consumption of over 8 ml-O2/min during perfusion. Histological findings showed that the hepatic architecture was almost completely preserved and numerous hepatocytes exhibited PAS-positive cytoplasmic glycogen deposits in these livers. These observations indicate that we have succeeded in developing an ex vivo functioning liver with an artificial perfusate employing artificial blood.

Prediction of graft viability from non-heart-beating donor pigs using hepatic microdialysate hypoxanthine levels

BACKGROUND

Non-heart-beating donors (NHBDs) are not yet acceptable in orthotopic liver transplantation (OLTX) because of the high frequency of primary graft nonfunction. In this study, we aimed to develop a new predictive method of graft viability in OLTX from NHBDs.

MATERIALS AND METHODS

(1) Pigs were subjected to 15 min of hepatic ischemia and reperfusion (I/R). (2) Porcine OLTX was performed using grafts obtained from NHBDs subjected to in situ warm ischemia (0, 30, and 60 min). During both operations, hepatic hypoxanthine levels were measured by a microdialysis method.

RESULTS

In the I/R model, hypoxanthine accumulated during ischemia and decreased after reperfusion, whereas marked xanthine and uric acid production were observed after reperfusion. In the NHBDs model, all of the 0-min group, 6 of 13 pigs in the 30-min group, and 1 of 6 pigs in the 60-min group survived more than 7 days. Significant increases of hypoxanthine levels were seen dependent on warm ischemic time. In the 30-min group, hypoxanthine levels were significantly higher in the pigs that died than in those that survived, and correlated with aspartate aminotransferase, lactate dehydrogenase, and adenosine triphosphate levels of recipients. Histological examination revealed that graft injury was severe in the pigs with higher hypoxanthine levels.

CONCLUSIONS

It is suggested that hepatic microdialysate hypoxanthine levels during warm ischemia in NHBDs were correlated with graft viability in the recipient. By using of this technique, prediction of the graft viability may be possible during donor operation.

A novel inhibitor of inducible nitric oxide synthase (ONO-1714) prevents critical warm ischemia-reperfusion injury in the pig liver

BACKGROUND

Recently, a novel inhibitor of inducible nitric oxide synthase, ONO-1714, was developed. We evaluated the effect of ONO-1714 on a critical warm I/R model of the pig liver.

METHODS

Pigs were subjected to 180 min of hepatic warm I/R under the extracorporeal circulation. We investigated the time course of changes in the serum NO2- + NO3- (NOx), the cellular distribution of endothelial and inducible nitric oxide synthase, thrombocyte-thrombi, and nitrotyrosine by immunohistochemistry. The hepatic tissue blood flow (HTBF) was measured continuously using a laser-Doppler blood flowmeter.

RESULTS

ONO-1714 at 0.05 mg/kg improved the survival rate from 54 (control group) to 100%. The serum NOx levels in the ONO-1714 group were significantly lower than those in the control group at 1, 1.5, 2, 3, and 6 hr after reperfusion. The serum aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels of the ONO-1714 group were significantly lower than the control group, and the HTBF of the ONO-1714 group was significantly higher than the control group. The formation of thrombocyte-thrombi and nitrotyrosine after reperfusion was significantly lower in the ONO-1714 group.

CONCLUSIONS

These results indicated that ONO-1714 improved the survival rates and attenuated I/R injury in a critical hepatic warm I/R model of the pig. ONO-1714 will be beneficial for hepatectomy or liver transplantation in the clinical field.

Changes in serum levels of apolipoprotein A-1 as an indicator of protein metabolism after hepatectomy

The clinical significance of serum apolipoprotein A-1 levels as an indicator of hepatic protein synthesis after hepatectomy was investigated. A total of 50 patients who had undergone hepatectomy at our department from 1997 to 1999 were selected for this study. The serum levels of apolipoprotein A-1, indocyanine green dye retention at 15 minutes, lectin-cholesterol acyltransferase, prealbumin, and high-density lipoprotein cholesterol were measured in these patients preoperatively and on postoperative days 7 and 14. The type of hepatic resection conducted was partial resection in 13 cases, subsegmentectomy in 13 cases, segmentectomy in five cases, and bisegmentectomy in 19 cases. All the patients tolerated the operation, and none of the cases had any severe complications, such as liver failure. In most cases, the serum apolipoprotein A-1 levels decreased on postoperative day 7 and recovered by day 14. There were no significant differences in the changes in apolipoprotein A-1 levels between patients with the individual types of operative procedures. The serum apolipoprotein A-1 levels showed significant correlations with the serum high-density lipoprotein cholesterol, lectin-cholesterol acyltransferase and prealbumin levels on postoperative days 7 and 14; however, there was no significant correlation with the indocyanine green retention test. When the cases were divided into three groups according to the serum level of apolipoprotein A-1 on postoperative day 7 (group A: over 81 mg/dl, group B: 61-80 mg/dl, group C: under 60 mg/dl), the serum indocyanine green retention, prealbumin, lectin-cholesterol acyltransferase and high-density lipoprotein cholesterol levels in group C were significantly lower than those in group A on postoperative day 7. On the basis of these results, it is suggested that the pattern of changes in the serum apolipoprotein A-1 levels may be a good indicator of the hepatic protein synthetic ability during the perioperative period after hepatectomy.

Elderly Japanese emigrants to Brazil before World War II: I. Clinical profiles based on specific historical background

OBJECTIVE

To research the demographic and clinical profiles of elderly Japanese emigrants, who arrived in Brazil before World War II, in order to give them appropriate psychogeriatric care.

DESIGN

Elderly Japanese immigrants aged 65 years and over, belonging to the Miyagi Association in the São Paulo Metropolitan Area, were targeted. They emigrated from Miyagi Prefecture to Brazil and are now living in the area. We were able to interview 166 respondents. All data were gathered using standardized interview methods covering (a) free interview about the immigration history, (b) demographics, and (c) physical status.

RESULTS

Through the free interview, we found their immigration histories, which affected their clinical profiles. The mean age and educational level were 77.5 years and 6.3 years, respectively. Sixty per cent of them immigrated when they were younger than 14. Ninety-four per cent of them still keep Japanese nationality. Fifty-seven per cent of them usually use Japanese, while 10% of them use Portuguese. Although their emigration histories were hard, 76% of them perceived their health as being excellent or relatively good. The percentages of subjects with histories of disease were hypertension, 52.5%; cardiac disease, 20.8%; diabetes mellitus, 24.2%; and hyperlipidemia, 25.0%, which were affected by the Brazilian environment.

CONCLUSION

The elderly Japanese who emigrated to Brazil before World War II have a unique historical and demographic background. Their clinical profiles cannot be fully understood without knowing their histories. They definitely need high quality international psychogeriatric care.

Elderly Japanese emigrants to Brazil before World War II: II. Prevalence of senile dementia

BACKGROUND

We previously showed the prevalence of dementia in the town of Tajiri (Miyagi Prefecture, Japan), and found it to be 8.0%. The first population-based study on dementia in Brazil (Catanduva) disclosed the prevalence as being 7.1%. To evaluate the effects of environment on development of dementia, elderly Japanese immigrants living in Brazil were examined. Brazil is the country with the largest number of Japanese immigrants.

METHODS

All immigrants aged 65 years and over from Miyagi Prefecture, living in the four cities of the São Paulo Metropolitan area were targeted (n = 192). We were able to examine 166 subjects (86.5%). The diagnosis of dementia was based on the DSM-IV with the severity assessed by the CDR (clinical dementia rating) scales. The cognitive ability screening instrument (CASI) was used for neuropsychological assessment.

RESULTS

Thirteen subjects were diagnosed with dementia, CDR 1-3, the prevalence being 7.8%. Older subjects suffered more from dementia, and, paradoxically, the more highly educated subjects also suffered more. All the CASI items, except for long-term memory and visual construction, significantly deteriorated in the CDR 0.5 group compared with the CDR 0 group.

COMMENTS

The prevalence of dementia was not thought to be affected by environmental factors. A paradoxically higher rate of dementia in the more educated subjects was probably due to the historical problems of the immigrants. Intact CASI item long-term memory in the CDR 0.5 group indicated that suspected dementia patients could maintain this function. This is the first epidemiological study on dementia in elderly Japanese immigrants in Brazil.

Epigenetic heterogeneity at imprinted loci in normal populations

Genomic imprinting is the phenomenon by which the two alleles of certain genes are differentially expressed according to their parental origin. Extensive analysis of allelic expression at multiple imprinted loci in a normal population has not performed so far. In the present study, we examined the allelic expression pattern of three imprinted genes in a panel of 262 Japanese normal individuals. We observed differences in the extent of maintenance of allele-specific expression of the three genes. The allelic expression of small nuclear ribonucleoprotein N (SNRPN) was stringently regulated while that of multimembrane-spanning polyspecific transporter-like gene 1 (IMPT1) showed a large degree of variation. Significant biallelic expression of insulin-like growth factor II (IGF2) was observed in about 10% of normal individuals. Our findings add to the accumulating evidence for variable allelic expression at multiple loci in a normal human population. This epigenetic heterogeneity can be a stable trait and potentially influence individual phenotypes.

Loss of imprinting of long QT intronic transcript 1 in colorectal cancer

Loss of imprinting (LOI) of the insulin-like growth factor 2 (IGF2) and H19 genes on human chromosome 11 has been found not only in childhood tumors but also in common adult cancers including colorectal cancer. Recently, a transcript called LIT1 (long QT intronic transcript 1) has been identified within the KvLQT1 locus on chromosome 11. LIT1 is expressed preferentially from the paternal allele and is transcribed in most human tissues. LOI of LIT1 was found in a considerable number of Beckwith-Wiedemann syndrome (BWS) patients, suggesting that it is associated with the etiology of BWS. Since LOI of IGF2 was observed in association with overexpression of IGF2 in colorectal cancer in our previous study, we examined the status of genomic imprinting of LIT1 and H19 in comparison with IGF2 in colorectal cancer. We examined 44 surgically dissected colorectal cancer tissues. Ten of them represented informative cases for LIT1. None of these patients exhibited loss of heterozygosity (LOH) of LIT1, and LOI of LIT1 was observed in 4 of the 10 (40%) informative patients, but not in non-cancerous tissues. Neither LOH nor LOI of H19 was observed. LOI of IGF2 was observed in 4 of 18 (22%) informative patients. These results suggest that LOI of LIT1 is frequently observed in colorectal cancer and may be a useful marker for diagnosis of colorectal cancer.

A novel maternally expressed gene, ATP10C, encodes a putative aminophospholipid translocase associated with Angelman syndrome

Lack of a maternal contribution to the genome at the imprinted domain on proximal chromosome 15 causes Angelman syndrome (AS) associated with neurobehavioral anomalies that include severe mental retardation, ataxia and epilepsy. Although AS patients have infrequent mutations in the gene encoding an E6-AP ubiquitin ligase required for long-term synaptic potentiation (LTP), most cases are attributed to de novo maternal deletions of 15q11-q13. We report here that a novel maternally expressed gene, ATP10C, maps within the most common interval of deletion and that ATP10C expression is virtually absent from AS patients with imprinting mutations, as well as from patients with maternal deletions of 15q11-q13.

Large-scale evaluation of imprinting status in the Prader-Willi syndrome region: an imprinted direct repeat cluster resembling small nucleolar RNA genes

Loss of paternal gene expression at the imprinted domain on proximal human chromosome 15 causes Prader-Willi syndrome (PWS), a complex multiple-anomaly disorder involving variable mental retardation, hyperphasia leading to obesity and infantile hypotonia with failure to thrive. Although numerous paternally expressed transcripts have been identified that reside in the candidate region, the individual contributions to the development of PWS have not been firmly established. Recent studies of mouse models carrying a cytogenetic deletion suggest that paternal deficiency of the SNRPN-IPW interval is critical for perinatal lethality of potential relevance to PWS. Here we determined the allelic expression profiles of a total of 118 cDNA clones using monochromosomal hybrids retaining either a paternal or maternal human chromosome 15. Our results demonstrated a preponderance of unusual transcripts lacking protein-coding potential that were expressed exclusively from the paternal copy of the critical interval. This interval was also found to encompass a large direct repeat (DR) cluster displaying a potentially active chromatin conformation of paternal origin, as suggested by enhanced sensitivity to nuclease digestion. Database searches revealed an unexpected organization of tandemly repeated consensus elements, all of which possessed well-defined box C and D sequences characteristic of small nucleolar RNAs (snoRNAs). Southern blot analysis further demonstrated a considerable degree of phylogenetic conservation of the DR locus in the genomes of all mammalian species tested, but not in chicken, Xenopus and Drosophila. These findings imply a potential direct contribution of the DR locus, representing a cluster of multiple snoRNA genes, to certain phenotypic features of PWS.

Targeted disruption of the human LIT1 locus defines a putative imprinting control element playing an essential role in Beckwith-Wiedemann syndrome

Human chromosome 11p15.5 harbors an intriguing imprinted gene cluster of 1 Mb. This imprinted domain is implicated in a wide variety of malignancies and Beckwith-Wiedemann syndrome (BWS). Recently, several lines of evidence have suggested that the BWS-associated imprinting cluster consists of separate chromosomal domains. We have previously identified LIT1, a paternally expressed antisense RNA within the KvLQT1 locus through a positional screening approach using human monochromosomal hybrids. KvLQT1 encompasses the translocation breakpoint cluster in BWS and patients exhibit frequent loss of maternal methylation at the LIT1 CpG island, implying a regulatory role for the LIT1 locus in coordinate control of the imprinting cluster. Here we generated modified human chromosomes carrying a targeted deletion of the LIT1 CpG island using recombination-proficient chicken DT40 cells. Consistent with the prediction, this mutation abolished LIT1 expression on the paternal chromosome, accompanied by activation of the normally silent paternal alleles of multiple imprinted loci at the centromeric domain including KvLQT1 and p57(KIP2). The deletion had no effect on imprinting of H19 located at the telomeric end of the cluster. Our findings demonstrate that the LIT1 CpG island can act as a negative regulator in cis for coordinate imprinting at the centromeric domain, thereby suggesting a role for the LIT1 locus in a BWS pathway leading to functional inactivation of p57(KIP2). Thus, the targeting and precise modification of human chromosomal alleles using the DT40 cell shuttle system can be used to define regulatory elements that confer long-range control of gene activity within chromosomal domains.

Changes in hepatic venous oxygen saturation in hepatic warm ischemia/reperfusion injury in pigs

To clarify the changes that occur in hepatic venous oxygen saturation (ShVO2) during hepatic ischemia/reperfusion (I/R) injury, we examined the relationship between ShVO2, hepatic tissue blood flow (HTBF), and portal vein pressure (PVP) in a warm I/R model using pig livers. Female pigs weighing 18-23 kg were subjected to warm I/R under extracorporeal circulation between the superior mesentric vein and the left jugular vein to avoid portal congestion. The warm ischemic times were 120 min (n = 4), 180 min (n = 14), and 240 min (n = 4). ShVO2, HTBF, and PVP were measured after reperfusion. The survival rates of the pigs 3 days after reperfusion were 100% in the 120-min group, 57% in the 180-min group, and 25% in the 240-min group. In the 180-min group, the ShVO2 was lower in the pigs that died than in those that survived. There was a significant correlation between ShVO2 and both PVP and HTBF after reperfusion. Histological examination revealed findings of severe I/R injury in pigs with a low ShVO2, and mild I/R injury in pigs with a stable ShVO2. These observations suggest that the changes in ShVO2 could reflect the degree of hepatic I/R injury, especially that related to microcirculatory disturbances occurring at the sinusoid levels.

LIT1, an imprinted antisense RNA in the human KvLQT1 locus identified by screening for differentially expressed transcripts using monochromosomal hybrids

Mammalian imprinted genes are frequently arranged in clusters on particular chromosomes. The imprinting cluster on human chromosome 11p15 is associated with Beckwith-Wiedemann syndrome (BWS) and a variety of human cancers. To clarify the genomic organization of the imprinted cluster, an extensive screen for differentially expressed transcripts in the 11p15 region was performed using monochromosomal hybrids with a paternal or maternal human chromosome 11. Here we describe an imprinted antisense transcript identified within the KvLQT1 locus, which is associated with multiple balanced chromosomal rearrangements in BWS and an additional breakpoint in embryonal rhabdoid tumors. The transcript, called LIT1 (long QT intronic transcript 1), was expressed preferentially from the paternal allele and produced in most human tissues. Methylation analysis revealed that an intronic CpG island was specifically methylated on the silent maternal allele and that four of 13 BWS patients showed complete loss of maternal methylation at the CpG island, suggesting that antisense regulation is involved in the development of human disease. In addition, we found that eight of eight Wilms' tumors exhibited normal imprinting of LIT1 and five of five tumors displayed normal differential methylation at the intronic CpG island. This contrasts with five of six tumors showing loss of imprinting of IGF2. We conclude that the imprinted gene domain at the KvLQT1 locus is discordantly regulated in cancer from the imprinted domain at the IGF2 locus. Thus, this positional approach using human monochromosomal hybrids could contribute to the efficient identification of imprinted loci in humans.

Mouse A9 cells containing single human chromosomes for analysis of genomic imprinting

To develop an systematic in vitro approach for the study of genomic imprinting, we generated a new library of human/mouse A9 monochromosomal hybrids. We used whole cell fusion and microcell-mediated chromosome transfer to generate A9 hybrids containing a single, intact, bsr-tagged human chromosome derived from primary fibroblasts. A9 hybrids were identified that contained either human chromosome 1, 2, 4, 5, 7, 8, 10, 11, 15, 18, 20, or X. The parental origin of these chromosomes was determined by polymorphic analysis using microsatellite markers, and matched hybrids containing maternal and paternal chromosomes were identified for chromosomes 5, 10, 11 and 15. The imprinted gene KVLQT1 on human chromosome 11p15.5 was expressed exclusively from the maternal chromosome in A9 hybrids, and the parental-origin-specific expression patterns of several other imprinted genes were also maintained. This library of human monochromosomal hybrids is a valuable resource for the mapping and cloning of human genes and is a novel in vitro system for the screening of imprinted genes and for their functional analysis.

Epigenetic reprogramming of the human H19 gene in mouse embryonic cells does not erase the primary parental imprint

BACKGROUND

Genomic imprinting in mammals is thought to result from epigenetic modifications to chromosomes during gametogenesis, which leads to differential allelic expression during development. There is a requirement for an appropriate experimental system to enable the analysis of the mechanisms of genomic imprinting during embryogenesis.

RESULTS

To develop a novel in vitro system for studying the molecular basis of genomic imprinting, we constructed mouse cell lines containing either a paternal or maternal human chromosome 11, by microcell-mediated chromosome transfer. Allele-specific expression and DNA methylation studies revealed that the imprinting status of the human H19 gene was maintained in mouse A9 mono-chromosomal hybrids. Each parental human chromosome was introduced independently into mouse near-diploid immortal fibroblasts (m5S) and two embryonal carcinoma (EC) cell lines (OTF9-63 and P19). The paternal allele of human H19 remained in a repressed state in m5S cells, but was de-repressed in both EC cells. The paternal H19 allele was demethylated extensively in OTF9-63 cells, whereas the only alteration in P19 hybrids was de novo methylation on both alleles in the 3' region. Following in vitro differentiation, the expressed paternal H19 allele was selectively repressed in differentiated derivatives of EC hybrids.

CONCLUSION

These results indicated that human imprint marks could function effectively in mouse cells, and that the imprinting process was epigenetically reprogrammed in embryonal carcinoma cells, without erasure of the primary imprint that marked the parental origin. Therefore, these mono-chromosomal hybrids could provide a valuable in vitro system to study the mechanisms involved in the regulation of imprinted gene expression.

Paternal expression of WT1 in human fibroblasts and lymphocytes

The Wilms' tumor suppressor gene ( WT1 ) was previously identified as being imprinted, with frequent maternal expression in human placentae and fetal brains. We examined the allele-specific expression of WT1 in cultured human fibroblasts from 15 individuals. Seven of 15 fibroblast lines were heterozygous for polymorphic alleles, and the expression patterns were variable, i.e., equal, unequal or monoallelic paternal expression in three, two and two cases, respectively. Exclusive paternal expression of WT1 was also shown in non-cultured peripheral lymphocytes from the latter two individuals. The allele-specific expression profiles of other imprinted genes, IGF2 and H19, on human chromosome 11 were constant and consistent with those in other tissues. Our unexpected observations of paternal or biallelic expression of WT1 in fibroblasts and lymphocytes, together with the previous findings of maternal or biallelic expression in placentae and brains, suggest that the allele-specific regulatory system of WT1 is unique and may be controlled by a putative tissue- and individual-specific modifier.

Evidence for uniparental, paternal expression of the human GABAA receptor subunit genes, using microcell-mediated chromosome transfer

We have constructed mouse A9 hybrids containing a single normal human chromosome 15, via microcell-mediated chromosome transfer. Cytogenetic and DNA-polymorphic analyses identified mouse A9 hybrids that contained either a paternal or maternal human chromosome 15. Paternal specific expression of the known imprinted genes SNRPN (small nuclear ribonucleoprotein-associated polypeptide N gene) and IPW (imprinted gene in the Prader-Willi syndrome region) was maintained in the A9 hybrids. Using this system, we first demonstrated that human GABAAreceptor subunit genes, GABRB3 , GABRA5 and GABRG3 , were expressed exclusively from the paternal allele and that E6-AP (E6-associated protein or UBE3A ) was biallelically expressed. Moreover, the 5' portion of the GABRB3 gene was found to be hypermethylated on the paternal allele. Our data imply that GABAAreceptor subunit genes are imprinted and are possible candidates for Prader-Willi syndrome, and that this human monochromosomal hybrid system enables the efficient analysis of imprinted loci.

Evidence for 54-kD protein in chicken kidney as a cytochrome P450 with a high molecular activity of 25-hydroxyvitamin D3 1 alpha-hydroxylase

Conversion of 25-hydroxyvitamin D3 (25(OH)D3) to the active vitamin D3, 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3) is catalyzed by 25(OH)D3, 1 alpha-hydroxylase(1 alpha-hydroxylase). It has been suggested that this enzyme is cytochrome P450 (P450). We purified 1 alpha-hydroxylase 430-fold from cholate-solubilized kidney mitochondria of vitamin D-deficient chickens by utilizing hydrophobic and ion-exchange column chromatographies. Enzymatic activity was assessed by measuring on HPLC the formation of 1 alpha,25(OH)2D3 from 25(OH)D3 in the assay mixture containing NADPH, adrenodoxin reductase, adrenodoxin as a reducing system. The purified enzyme showed a CO-difference spectrum characteristic of P450. The molecular activity of this preparation was calculated to be 8.7 pmol/min/pmol P450. This value was higher by more than 87-fold than those reported so far. The present preparation was found to contain several proteins on SDS-PAGE. Among them, only the 54-kD protein became undetectable when kidney mitochondria from normal and vitamin D-replete chickens, where 1 alpha-hydroxylase activities were 15 and 0% of that found in vitamin D-deficient chicken, respectively, were used as the starting enzyme sources. Furthermore, the band intensity of the 54-kD protein accounted for the spectrophotometrically determined amount of P450 in the preparation. These results suggest that the 54-kD protein is 1 alpha-hydroxylase.

[Generalized choreic movement associated with subarachnoid hemorrhage]

A case of generalized choreic movement associated with subarachnoid hemorrhage is reported. A 71 year-old hypertensive woman suddenly developed severe headache 14 days before admission. Consciousness disturbance and involuntary movement involving the face and upper extremities appeared about 8 days after onset. The involuntary motion was diagnosed as generalized choreic movement. CT scans showed subarachnoid hemorrhage with ventricular dilatation and periventricular lucency involving bilateral caudate nuclei. On admission the patient was stuporous with Hunt & Kosnik Grade 4. She showed involuntary choreic movement in both arms, trunk and face; hemiparenis and hyperreflexia were absent. An angiography revealed a right internal carotid-anterior choroidal artery aneurysm with vasospasm. After clipping the aneurysm in the following day, the consciousness disturbance and choreic movement gradually improved. By eight days after operation, the choreic movement completely disappeared. An MRI showed lacunar infarcts in the bilateral basal ganglia, predominantly in the caudate nuclei. In our case, the choreic movement is supposed to have been caused by impaired circulation in the bilateral corpora striata due to vasospasm and hydrocephalus after subarachnoid hemorrhage, in addition to the preexisting lacunar infarcts in the basal ganglia. This is claimed to be the first reported case of generalized choreic movement in associated with subarachnoid hemorrhage, which improved after surgery.

The relationship between chest pain during thallium-201 scintigraphy with dipyridamole and myocardial ischemia

Dipyridamole thallium-201 scintigraphy (DP-Tl) and coronary angiography were studied on 74 patients with suspected coronary artery disease. We compared the clinical features, hemodynamic responses, angiographic results and scintigraphic findings of patients who had chest pain during DP-Tl testing ('chest pain' group) with those of patients who did not have chest pain ('no pain' group). Thirty eight (51%) of the 74 patients developed chest pain. Heart rate and rate pressure product during DP infusion of 'chest pain' group were greater than those of the 'no pain' group (p less than 0.05). Ischemic ST depression was more frequently observed among 'chest pain' patients (p less than 0.01). There were no differences in angiographic severity of coronary artery disease between 'chest pain' and 'no pain' group. Also, we could find no differences in extent and severity scores of perfusion defects and washout abnormalities between the two groups. However, when patients with myocardial infarction were excluded, the 'chest pain' group had significantly greater extent and severity scores of washout abnormalities than the 'no pain' group (extent score: 38 +/- 8 vs 18 +/- 5, p less than 0.05, severity score: 55 +/- 15 vs 18 +/- 7, p less than 0.01). Our study indicated that in patients without myocardial infarction, patients with 'chest pain' had more severe ischemia than 'no pain' patients. But in patients with myocardial infarction, myocardial ischemia not accompanied by chest pain might be as severe as that with chest pain. The presence or absence of myocardial infarction might have great influence on results regarding the relation of chest pain to myocardial ischemia.

[Simultaneous assessment of wall motion and myocardial perfusion by technetium-99m methoxy isobutyl isonitrile]

The aim of this study was to assess whether or not myocardial uptake of Technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) indicated myocardial viability. We performed simultaneous Tc-MIBI angiography and myocardial SPECT at rest on 12 patients with suspected coronary artery disease. Left ventricle was divided into 3 segments, and regional wall motion was graded as normal, hypokinesis and akinesis/dyskinesis. Myocardial uptake of Tc-MIBI was assessed as normal, reduced and absent in each segment. In segments with normal and reduced Tc-MIBI uptake, 7% (2 of 28) and 33% (2 of 6) showed wall motion abnormalities of akinesis/dyskinesis, respectively. However, all segments with absent Tc-MIBI uptake had asynergy of akinesis/dyskinesis (2 of 2, 100%). Myocardial Tc-MIBI uptake at rest indicated wall motion abnormalities and was considered to be useful for the evaluation of myocardial viability. First-pass radionuclide angiography followed by myocardial SPECT with Tc-MIBI demonstrated to be useful for the simultaneous assessment of the left ventricular wall motion and myocardial perfusion.

[Evaluation of silent myocardial ischemia by exercise radionuclide ventriculography: comparison between patients with and without old myocardial infarction]

We evaluated left ventricular systolic function during exercise in patients with silent or symptomatic myocardial ischemia by radionuclide ventriculography (RNV). The subjects consisted of 61 patients who had evidence of myocardial ischemia during exercise RNV defined as positive exercise electrocardiographic changes and angiographically documented coronary artery disease. The patients without angina during exercise (SMI) had less exercise-induced left ventricular systolic dysfunction than patients with angina (CP) (change in ejection fraction during exercise: delta EF; -1 +/- 13 vs -6 +/- 10%, p less than 0.05, systolic blood pressure/end-systolic volume in exercise divided by systolic blood pressure/end-systolic volume in rest: SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.8 +/- 0.3, p less than 0.05). The 61 patients were divided into two groups, that is, those with and without old myocardial infarction (OMI), and we compared the degree of left ventricular systolic dysfunction during exercise between SMI and CP by RNV in each group. In patients without OMI, SMI had less exercise-induced left ventricular dysfunction than CP (delta EF; 1 +/- 12 vs -10 +/- 8%, p less than 0.01, SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.7 +/- 0.2, p less than 0.01). However, there were no differences between SMI and CP with OMI. In conclusion, it was thought that SMI without OMI was less degree of myocardial ischemia, and that SMI with OMI was potentially caused by some factors except for the degree of myocardial ischemia.

In situ hybridisation with digoxigenin-labelled DNA probes for detection of viral genomes

The applicability of a recently developed non-radioactive DNA labelling and detection method, which uses the digoxigenin (DIG) enzyme linked immunosorbent assay (ELISA) system, for the detection of viral infections in pathology specimens by in situ hybridisation, was examined. Its efficacy was compared with that of biotin and radioisotope labelling methods. Three cases of progressive multifocal leucoencephalopathy, two of verruca vulgaris, and seven cases of laryngeal papilloma were studied. The sensitivity of the DIG labelled probe was almost the same as that of a 35S-labelled probe in the dot-blot hybridisation test. Using in situ hybridisation with 35S-labelled and DIG labelled probes, the levels of the hybridised signals detected were similar. The biotin labelled probe was less sensitive, particularly in the cases of laryngeal papilloma. The DIG labelling and detection method was highly sensitive and applicable to the detection of viral infection by ISH, and is preferable to a radiolabelled probe, especially when in situ hybridisation is done in the pathology laboratory.

[Effect of aminophylline on thallium-201 washout rate during myocardial perfusion imaging with dipyridamole]

Thallium-201 myocardial perfusion imaging with dipyridamole was performed on 78 patients (pts) with suspected coronary artery disease (CAD). Twenty eight pts had normal coronary arteries (control group), and 50 pts had 50% or greater stenosis in one or more major coronary arteries (CAD group). In control group, aminophylline (Am) was infused intravenously on 12 pts during dipyridamole testing. Mean washout rate (WR) of these 12 pts was greater than that of 16 pts without Am (42% vs 35%, p less than 0.01). Then normal limit of WR was defined separately from the pts of control group with and without Am. The sensitivity for detecting the pts with CAD by WR analysis which normal limit was calculated separately with and without Am was 92% (46/50). When normal limit of WR was determined from all pts in control group, the sensitivity decreased to 84% (42/50). Am significantly affected thallium-201 washout during dipyridamole testing. WR of CAD pts should be estimated by specific set of normal limit with and without Am.

The role of late potentials in the assessment of myocardial degeneration in idiopathic dilated cardiomyopathy

In order to determine whether or not late potentials indicate either a degree of myocardial fibrosis or necrosis, the relationship between late potentials and thallium-201 myocardial perfusion images was studied in 13 patients with idiopathic dilated cardiomyopathy. Late potentials were defined as low-amplitude waveforms having duration of over 20 msec after the end of the QRS complex using a high-resolution ECG (Marquette electronics, MAC 1). In the T1-201 myocardial perfusion image, the segmental perfusion state was assessed by use of a parameter called the uptake index (= normalized sector counts/maximal normalized sector counts) of each of 6 different segments. Segments which showed an uptake index of -2SD less than the normal value were judged to be abnormal. Late potentials were detected in 8 (61.5%) of the 13 patients. All of the patients showing late potentials also had ventricular tachycardia. Among the patients showing no late potential, ventricular tachycardia was observed in only one patient. Seven of the 8 patients showing late potentials and 3 of 5 patients not showing late potentials, however, had both a higher degree and a greater extent of abnormal perfusion images than the patients not showing late potentials. Therefore, late potentials may reflect a degree of myocardial fibrosis or necrosis in patients with dilated cardiomyopathy, those showing abnormal thallium images are apt to show late potentials, and these patients seem to be also at a high risk of suffering from ventricular tachycardia.

[Detection of coronary artery disease by exercise radionuclide ventriculography: using sector analysis]

Exercise first-pass radionuclide ventriculography was performed on 65 patients with coronary artery disease (CAD) and 18 control subjects with normal coronary artery, Left ventricle (LV) was divided into 5 sectors in radial, and volume curves were generated for whole LV and each sector for estimating LVEF and time to end systole (TES). The differences of TES between whole LV and each sector were calculated and these 5 differences were averaged (Variation of TES). We defined this Variation of TES as an index of LV asynchrony, and used for detection of CAD. The overall sensitivity and specificity for identifying CAD were 63% and 83% (LVEF during exercise), 51% and 83% (delta LVEF). Variation of TES during exercise had a sensitivity and a specificity of 88% and 83%, and was more sensitive than both LVEF during exercise and delta LVEF (p less than 0.01). In conclusion, Variation of TES was a good marker of LV asynchrony and useful for the detection of CAD.

Spatial distribution of exercise-induced ST-segment depression and U-wave inversion in identifying the ischemic site in patients with coronary artery disease

Eighty-seven unipolar electrocardiograms were simultaneously recorded before and after symptom-limited treadmill exercise in 75 patients with coronary artery narrowing (greater than equal to 70%) and without previous myocardial infarction. Body surface distributions of ST segment depression were divided into 3 types; upper, lower, and diffuse types. Body surface distributions of U-wave inversion were divided into 2 types; upper, and lower types. These distribution patterns were compared with the location of ischemia determined by T1-201 exercise myocardial perfusion imaging. For ST-segment depression, a considerable number of patients had diffuse-type ST depression, whether the site of ischemia was anterior (22/32, 69%), inferior (18/27, 67%) or both (5/5, 100%). However, upper-type ST depression was associated with anterior ischemia, and lower-type ST depression, with inferior ischemia. The sensitivity and specificity of the spatial distribution of ST depression in identifying the myocardial ischemic site were 27% and 95% for anterior ischemia. The sensitivity and specificity of the spatial distribution of St depression in identifying the myocardial ischemic site were 27% and 95% for anterior ischemia respectively, and 28% and 88% for inferior ischemia, respectively. The incidence of U-wave inversion was moderate (29/75, 39%), but the distribution pattern was specific for the site of ischemia; upper-type U inversion associated with anterior ischemia, and lower type with inferior ischemia. The sensitivity and specificity were 59% and 100% for anterior ischemia respectively, and 22% and 100% for inferior ischemia respectively. By a combination of ST-depression and U-inversion, the sensitivity and specificity were 78% and 95% for anterior ischemia, and 44% and 88% for inferior ischemia. Body surface electrocardiographic mapping provided important information in the non-invasive diagnosis of the site of myocardial ischemia.

Relationship of thallium-201 defect and left ventricular function after dipyridamole infusion

Tl-201 imaging and first-pass radionuclide ventriculography (RNV) by 4 min infusion of 0.56 mg/kg dipyridamole were performed on 22 patients with coronary artery disease in order to know the relationship of myocardial perfusion and left ventricular function after dipyridamole-infusion, and thereby to define whether Tl-201 defect with dipyridamole could imply myocardial ischemia. Initial and delayed Tl-201 images were divided into anterior, apical, and infero-posterior segments, and segmental perfusion defects were categorized as reversible, fixed and no defect. RNV on the 30-degree right anterior oblique view was also divided into anterior, apical, and infero-posterior wall to be evaluated for regional wall motion by a 5 point score before and after dipyridamole. Changes in left ventricular ejection fraction (LVEF) with dipyridamole were also calculated. Normal responses of regional wall motion and LVEF to dipyridamole were established from the data of 14 normal subjects. Reversible defects were closely associated (69%) with an abnormal response of regional wall motion (score decrease of 1 or more after dipyridamole). Both fixed defects and no defects showed little association with abnormal response of regional wall motion. Moreover, 77% of the patients having reversible-defect segment showed an abnormal response of LVEF (reduction of 3% or more following dipyridamole). However, patients without reversible defect did not show an abnormal response to dipyridamole. These results suggest that dipyridamole-induced Tl-201 defects represent a myocardial ischemia which causes a reduction of ventricular function.