Loss of heterozygosity and microsatellite instability in ductal carcinoma in situ of the breast

To investigate the alterations of genetic instabilities in carcinogenesis of the breast, we analyzed the allelotypic profile of 65 ductal carcinomas in situ (DCIS), compared with that of 207 invasive ductal carcinomas (IDC) of the breast. These studies were performed by means of examining microsatellite-length polymorphisms at seven loci (AluVpa, ESR, D11S988, D13S267, D16S398, D17S1159, and D17S855) from microdissected paraffin sections. Allelic loss or imbalance, considered a loss of heterozygosity (LOH), tended to be more frequently seen in IDC than in DCIS. In particular, the frequency of LOH at the 17p locus was significantly higher in IDC than in DCIS (42 vs. 23%, P=0.022). LOH in DCIS was most frequently seen at D16S398 (26%). LOH frequency at D16S398 in low- and intermediate-grade DCIS was higher than that in high-grade DCIS, while LOH frequencies at D11S988 and D17S1159 in low- and intermediate-grade DCIS was lower than those in high-grade DCIS. LOH frequency at D11S988 in non-comedo type DCIS was lower than that in comedo type DCIS. Furthermore, the frequency of microsatellite instability (MSI) at only one locus in DCIS (28%) was statistically higher than that in IDC (6%) (P<0.001), while there was no difference between the frequency of MSI at multiple loci in DCIS (6%) and that in IDC (3%). Together, these observations indicate that chromosomal losses of 16q may occur in low- and intermediate-grade DCIS and those of 11p and 17p may occur high-grade DCIS, and that MSI occurring at only one locus is not yet clear and MSI at multiple loci is uncommon in not only IDC but also DCIS of the breast.

Effect of sealant viscosity on the penetration of resin into etched human enamel

This study was designed to investigate the relationship between the etched depth, penetration of sealants and marginal seal. Sixty unerupted lower first premolars extracted from patients for orthodontic reasons were thoroughly cleaned and stored in an antiseptic Ringer's solution at 4 degrees C. A "window" on the occlusal of 15 of the premolars, including both mesial and distal pits, was developed by painting nail varnish around the border of the occlusal surfaces. Etching was then done with 35% phosphoric acid for 60 seconds to all 60 premolars. Five of the "window" teeth were evaluated by microradiography to determine the etched depth of the superficial and subsurface enamel. Five were prepared for SEM analysis to observe the change of the superficial etched enamel surface. Another five "window" teeth were embedded in epoxy resin and sectioned parallel to the long axis of the tooth through the fissures in order to observe the subsurface depth of the etch by SEM analysis. The other 45 teeth were divided into three groups of 15 teeth each. Fissures of each group of teeth were sealed using Prisma-Shield (LD Caulk), Concise White Sealant (3M Dental Products) or Teethmate A (Kuraray) sealants and stored in water (37 degrees C) for 24 hours. They were then sectioned and demineralized before being examined by a scanning electron microscope. Photographs of secondary electron image (SEI) were done to gradate the resin-infiltrated enamel and resin tags for these sealants. After SEM observation, the 15 samples of each applied sealant were polished to a high gloss again and placed in a silver nitrate solution for 24 hours before being examined under the SEM equipped with a back-scatter electron detector. Data were then analyzed using the Welch and Student t-tests. Results showed that fissured enamel of unerupted human lower first premolars became porous after etching with 35% phosphoric acid. The low viscosity sealant Teethmate A (approximately 260 mPa.s), penetrated fully and formed a resin-infiltrated layer in enamel beyond the etched depth. However, the high viscosity sealants (Prisma-Shield and Concise White Sealant) did not penetrate enough to ensure that the acid-etched enamel was infiltrated sufficiently by the sealant to insure good marginal seals.

[Prediction of cardiac sympathetic nerve activity and cardiac functional outcome after treatment in patients with dilated cardiomyopathy: examination using dobutamine gated blood pool scintigraphy]

OBJECTIVES

This study evaluated whether dobutamine gated blood pool scintigraphy can predict improvement of cardiac sympathetic nerve activity and cardiac function.

METHODS

Sixteen patients(10 men and 6 women, mean age 59 +/- 13 years) with dilated cardiomyopathy underwent dobutamine gated blood pool scintigraphy to measure left ventricular ejection fraction (LVEF) using tracer at 0, 5, 10 and 15 micrograms/kg/min before treatment. Patients were divided into good responders (LVEF increase > or = 15%) 8 patients(GR Group) and poor responders(LVEF increase < 15%) 8 patients (PR Group) after treatment with beta-blocker or amiodarone with a background treatment of digitalis, diuretics and angiotensin converting enzyme inhibitor. I-123 metaiodobenzylguanidine(MIBG) imaging to evaluate cardiac sympathetic nerve activity and echocardiography were performed before and at one year after treatment. MIBG imaging was obtained 4 hours after tracer injection, and the heart/mediastinum count ratio(H/M ratio) calculated from the anterior planar image and the total defect score(TDS) from the single photon emission computed tomography image. LVEF and left ventricular endo-diastolic dimension (LVDd) were measured by echocardiography and New York Heart Association(NYHA) functional class was evaluated.

RESULTS

The GR Group showed TDS decreased from 28 +/- 6 to 17 +/- 12(p < 0.05), H/M ratio increased from 1.79 +/- 0.26 to 2.07 +/- 0.32(p < 0.05), LVEF increased from 29 +/- 8% to 48 +/- 10%(p < 0.01), and LVDd decreased from 65 +/- 4 mm to 58 +/- 5 mm(p < 0.05). In contrast, the PR Group showed no significant changes in TDS, H/M ratio, LVEF and LVDd. NYHA functional class improved in both groups. The improvement was better in the GR Group than in the PR Group.

CONCLUSIONS

Dobutamine gated blood pool scintigraphy is useful to predict the improvement of the cardiac sympathetic nerve activity and cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy.

Augmented responses of angiotensin I and II in patients with ischemic heart disease: relation to left ventricular function

To evaluate the effects of left ventricular (LV) dysfunction upon the sympathetic nervous and renin-aldosterone-angiotensin systems, neurohormonal factors were measured in patients with ischemic heart disease. Eleven patients were divided into two groups by their LV ejection fraction based on previous catheterization; preserved (EF > or = 60%) and impaired (EF < 60%) LV systolic function groups. They performed supine ergometer exercise and blood samples were drawn at rest and at peak exercise. After dynamic exercise, plasma norepinephrine was significantly (p < 0.05) increased in patients with preserved LV function, whereas it was not altered in patients with impaired LV function (norepinephrine 20.8 +/- 20.5 vs 45.8 +/- 41.9, respectively). We observed no differences in basal or peak levels of neurohormonal factors, including plasma renin activity, aldosterone, and brain natriuretic peptide (BNP), between the groups. Although the plasma levels of angiotensin I and II were not different in the two groups at rest or at peak exercise, their increasing ratios from rest to peak exercise were significantly higher in patients with impaired LV function compared to those with preserved LV function (angiotensin I; -18.6 +/- 31.0% vs 64.8 +/- 66.5%, p < 0.05, angiotensin II; -5.9 +/- 41.2% vs 60.7 +/- 40.4% , p < 0.05). These results suggest that the increasing ratios of angiotensin I and II are superior to BNP as predictors of LV dysfunction, and that the sympathetic nervous system has already been activated even at rest and did not respond to dynamic exercise in patients with LV dysfunction in ischemic heart disease.

[Copper deficiency anemia and neutropenia secondary to total gastrectomy]

We report a case of copper deficiency with anemia and neutropenia due to dumping syndrome after total gastrectomy. Parenteral nutrition containing cupric sulfate promptly improved the dumping syndrome, anemia and neutropenia. This case suggests that total gastrectomy with dumping syndrome can cause copper deficiency, and that copper deficiency should be considered when encountering similar patients with severe anemia and neutropenia.

[Significance of exercise-induced ST segment depression in patients with myocardial infarction involving the left circumflex artery: evaluation by exercise thallium-201 myocardial single photon emission computed tomography]

The significance of exercise-induced ST segment depression in patients with left circumflex artery involvement was investigated by comparing exercise electrocardiography with exercise thallium-201 single photon emission computed tomography(Tl-SPECT) and the wall motion estimated by left ventriculography. Tl-SPECT and exercise electrocardiography were simultaneously performed in 51 patients with left circumflex artery involvement(angina pectoris 30, myocardial infarction 21). In patients with myocardial infarction, exercise-induced ST depression was frequently found in the V2, V3 and V4 leads. In patients with angina pectoris, ST depression was frequently found in the II, III, aVF, V5 and V6 leads. There was no obvious difference in the leads of ST depression in patients with myocardial infarction with ischemia and without ischemia on Tl-SPECT images. In patients with myocardial infarction, the lateral wall motion of the infarcted area evaluated by left ventriculography was more significantly impaired in the patients with ST depression than without ST depression(p < 0.01). Exercise-induced ST depression in the precordial leads possibly reflects wall motion abnormality rather than ischemia in the lateral infarcted myocardium.

Expression of estrogen receptor alpha exon 5 and 7 deletion variant in human breast cancers

BACKGROUND

An exon deletion variant of estrogen receptor (ER) mRNA has been reported, as one of the possible mechanisms of loss of ER function.

METHODS

We examined the expression of exons 3, 5, and 7 in ER alpha mRNA and the frequency of exon deletion variant expression in 64 cases of human breast cancers and in 8 non-cancerous breast tissues using reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Approximately the same amount of wild-type (wt) mRNA was detected in all the non-cancerous breast tissues. In cancers, expression of wild-type exon 3 (w3), exon 5 (w5), and exon 7 (w7) was detected in 93.5%, 93.5%, and 91.3% of ER alpha protein (pER) positive cases, respectively, and 27.8%, 38.9%, and 44.4% in negative cases, respectively (p < 0.0001, p = 0.0035, and p = 0.0002). Although the variants for exon 5 (d5) and 7 (d7) were detected in both non-cancerous and cancerous tissues respectively, the variant for exon 3 was not detected at all. Comparatively, the ratio of d5/w5 was significantly higher in pER positive and progesterone receptor protein (pPgR) negative cases.

CONCLUSIONS

We suspect that the exon 5 deletion does not work as a dominant positive.

Prediction of functional recovery after revascularization in coronary artery disease using (18)F-FDG and (123)I-BMIPP SPECT

STUDY OBJECTIVES

Clinical studies comparing fatty acid and glucose metabolism in relation to functional recovery of ischemic myocardium after coronary revascularization are scarce. This study evaluated the recovery of regional and global left ventricular function after coronary revascularization in relation to uptake patterns of beta-methyl-iodophenyl-pentadecanoic acid (BMIPP) and fluorodeoxyglucose (FDG) in patients with ischemic myocardial dysfunction.

METHODS

Patients with ischemic regional wall motion abnormality underwent baseline viability imaging with (18)F-FDG, (123)I-BMIPP, and (99m)Tc- methoxyisobutylisonitrile, and the regions with evidence for maintained tissue viability were revascularized. Mismatch of uptake score between two different single-photon emission CT (SPECT) images in the same myocardial region was graded as low or high mismatch. Regional and global left ventricular functional changes after revascularization were analyzed in relation to mismatch severity and difference of total uptake score in each SPECT image pair. A total of 33 vessels in 30 patients related to the asynergic regions were revascularized, and a total of 100 myocardial segments perfused by the revascularized vessels were analyzed.

RESULTS

Segments showing high metabolic mismatch (FDG/BMIPP) had lowest regional wall motion score at baseline, representing the most severely impaired ischemic myocardium, and had highest improvement in regional wall motion score after revascularization. Difference of total uptake score between FDG and BMIPP showed a significant positive correlation with difference of ejection fraction between pre- and postrevascularization (r = 0.774, p < 0.0001).

CONCLUSIONS

Combined metabolic SPECT imaging with FDG and BMIPP has the potential to identify severely impaired ischemic myocardium leading to more efficient therapeutic management of patients with coronary artery disease.

Decreased expression of p33ING1 mRNA in lymphoid malignancies

The ING1 is a newly cloned putative tumor-suppressor gene, which is involved in the p53 signaling pathway. We found decreased expression of ING1 mRNA in 4 of 5 T-cell lines and 5 of 11 B-cell lines including two Burkitt lymphomas and two myelomas. These observations suggest that decreased ING1 expression might play an important role in the development or progression of some lymphoid tumors. Polymerase chain reaction-SSCP and sequencing analyses found neither point mutations nor small deletions in the ING1 gene, suggesting that decreased expression is due to transcriptional or post-transcriptional mechanisms.

[Effect of exercise therapy on oxygen consumption in patients with chronic heart failure]

The effect of exercise training on delta Vo2/delta WR was studied in 12 patients(11 men, one woman, mean age 62 +/- 9 yr)with chronic heart failure(old myocardial infarction, dilated cardiomyopathy, patients after coronary arterial bypass graft surgery and patients after aortic valve replacement). Cardiopulmonary exercise testing was performed to decide the exercise tolerance and assess the delta Vo2/delta WR. Patients underwent physical training at the anaerobic threshold for 3 months. Cardiopulmonary exercise testing was performed after the second week and after the third month. The anaerobic threshold increased at the third month compared with before exercise testing and the second week(p < 0.05, respectively) (before exercise testing: 13.6 +/- 2.0 ml/min/kg, the second week: 14.7 +/- 2.5 ml/min/kg, the third month: 16.2 +/- 2.1 ml/min/kg). The delta Vo2/delta WR increased at the second week compared with before exercise testing(before exercise testing: 8.9 +/- 1.9 ml/min/W, the second week: 10.6 +/- 1.9 ml/min/W, p < 0.05), but significantly decreased at the third month compared with the second week(the third month: 9.4 +/- 1.7 ml/min/W, p < 0.05). Serial increase of the anaerobic threshold and the peak Vo2/heart rate suggests that the exercise tolerance and cardiac function of the patients improved significantly. The increase of the delta Vo2/delta WR after the first 2 weeks seemed to depend on the luxury blood supply to both working and non-working muscles. The decrease of delta Vo2/delta WR at the third month may be due to the redistribution of the blood flow to the working muscles.

Decreased expression of p33ING1 mRNA in lymphoid malignancies

The ING1 is a newly cloned putative tumor-suppressor gene, which is involved in the p53 signaling pathway. We found decreased expression of ING1 mRNA in 4 of 5 T-cell lines and 5 of 11 B-cell lines including two Burkitt lymphomas and two myelomas. These observations suggest that decreased ING1 expression might play an important role in the development or progression of some lymphoid tumors. Polymerase chain reaction-SSCP and sequencing analyses found neither point mutations nor small deletions in the ING1 gene, suggesting that decreased expression is due to transcriptional or post-transcriptional mechanisms.

A cytokinin-repressed gene in cucumber for a bHLH protein homologue is regulated by light

CRR12 was identified as a cytokinin-repressed gene encoding a cucumber homologue for a basic region/helix-loop-helix protein. The level of CRR12 mRNA decreased in response to either cytokinins or light in etiolated cotyledons. The level was low in cotyledons and leaves of light-grown plants, but it increased during dark incubation.

Suppression of ING1 expression in sporadic breast cancer

Down regulation of the ING1 candidate tumour suppressor promotes growth in soft agar and focus formation in vitro and tumour formation in vivo. ING1 encodes a nuclear, cell cycle-regulated protein, overexpression of which efficiently blocks cell growth and is capable of inducing apoptosis in different experimental systems. Here we present the first report of ING1 mutation and expression analysis in a total of 452 cancer samples. One germline missense alteration and three germline silent alterations were detected in 377 primary breast cancers while marked (2 - 10-fold) decreases in ING1 mRNA expression were seen in 44% of primary breast cancers and in ten of ten breast cancer cell lines examined. Furthermore, the majority of breast cancers (58%) showing decreased ING1 expression had metastasized to regional lymph nodes whereas only 9% of cancers with elevated ING1 expression, compared to adjacent normal tissues, were metastatic. Thus, ING1 mutation is very rare in breast or ovarian cancers, however, repression of ING1 expression frequently accompanies tumour development of breast cancer.

[The characteristics of myocardial fatty acid metabolism in patients with left ventricular hypertrophy]

We evaluated the characteristics of myocardial fatty acid metabolism in patients with left ventricular hypertrophy (LVH). Myocardial imaging with 123I-beta-methyl iodophenyl pentadecanoic acid (BMIPP) was performed in 28 patients with hypertrophic cardiomyopathy (HCM), 15 patients with hypertensive heart disease (HHD), 13 patients with aortic stenosis (AS) and 8 normal controls (NC). The patients with HCM consisted of 13 patients of asymmetric septal hypertrophy (ASH), 7 patients of diffuse hypertrophy (Diffuse-HCM) and 8 patients of apical hypertrophy (APH). Planar and SPECT images of BMIPP were acquired 15 minutes and 4 hours after tracer injection. Resting 201Tl SPECT images and echocardiography were also performed on other days. We calculated heart/mediastinum count ratio and washout rate of BMIPP by using planar image. In patients with LVH, the incidence of reduced BMIPP uptake was more frequent than that of reduced 201Tl uptake. In delayed images, more than 60% of patients with LVH reduced BMIPP uptake, especially remarkable for patients with ASH and APH. The washout rate of all cardiac hypertrophic disorders was tended to be higher than that of normal subjects. Reduced BMIPP uptake was frequently found in septal portion of anterior and inferior wall in patients with ASH, in inferior wall in patients with Diffuse-HCM and HHD, in apex in patients with APH and AS. These results suggest that BMIPP scintigraphy can differentiate three types of cardiac hypertrophy.

DNA methylation analysis at distal and proximal promoter regions of the oestrogen receptor gene in breast cancers

Oestrogen receptor alpha (ER-alpha) gene has two specific promoters, distal (P0) and proximal (P1), which induce almost identical transcripts in size due to different splicing. We examined the methylation at both promoter regions of the ER-alpha gene using HpaII, a methylation-sensitive restriction enzyme, prior to polymerase chain reaction (PCR) amplification. To confirm the results of PCR-based methylation analysis, Southern hybridization was also performed. Twenty of 29 patients with ER-alpha-positive tumours and five of 27 with ER-alpha-negative tumours were unmethylated at the P1 promoter region of the ER-alpha gene. The incidence of methylation was highly negatively correlated with ER-alpha expression (P = 0.0002). A similarly negative correlation was observed at the P0 promoter region of the ER-alpha gene (P = 0.0154). Additionally, the tumours with the ER-alpha gene hypermethylated at both promoter regions had definitely negative ER-alpha values. It was suggested that this epigenetic change might control ER-alpha expression, and might play an important role in the loss of hormone-dependence in breast cancer.

Sensitive measurement of serum abnormal prothrombin (PIVKA-II) as a marker of hepatocellular carcinoma

BACKGROUND/AIMS

The usefulness of abnormal prothrombin (PIVKA-II) for diagnosis of small HCC has been limited by its low sensitivity, despite a high specificity.

METHODOLOGY

The serum concentration of PIVKA-II was determined by using a new sensitive enzyme immunoassay (EIA) kit in patients with hepatocellular carcinoma (HCC), liver cirrhosis (LC), or chronic hepatitis (CH) and normal controls (NC). alpha-Fetoprotein (AFP) was simultaneously determined in same patients.

RESULTS

This kit has made it possible to detect low concentrations of PIVKA-II in the NC. The serum PIVKA-II concentration (mean +/- SE) was 15.7 +/- 1.1 mAu/ml, 16.1 +/- 2.0 mAu/ml, 26.3 +/- 7.2 mAu/ml and 5420.3 +/- 3960.0 mAu/ml in NC, CH, LC and HCC, respectively. Among 106 patients with HCC, 74 patients (69.8%) were positive for PIVKA-II (> or = 40 mAu/ml), while only 9 patients out of 68 patients with LC were positive (13.2%) and only 2 out of 90 patients with CH were positive (2.2%). No significant correlation was observed between AFP and PIVKA-II levels. With combined assay of AFP and PIVKA-II, the positive rate for HCC was increased to 78.3%. Among 14 patients with HCC < 20 mm in diameter. 7 were positive for PIVKA-II, and 6 out of 10 patients with HCC between 20 and 30 mm in diameter were positive for PIVKA-II. There was a correlation between tumor size and the PIVKA-II level.

CONCLUSIONS

Determination of PIVKA-II by this new EIA kit could be useful for the diagnosis of HCC, especially combined with determination of AFP.

[Usefulness of 18F-FDG PET for diagnosis of cardiac sarcoidosis]

Cardiac sarcoidosis, the main cause of death among patients with sarcoidosis, frequently becomes clinically apparent when the disease is far advanced. To evaluate the usefulness of the 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in detecting cardiac sarcoidosis, 18F-FDG PET was performed in 16 patients with sarcoidosis (13 female, 63 +/- 12 yrs), compared with scintigraphic findings of 99mTc-MIBI and 67Ga. Ten of 16 patients were considered to have cardiac complications on clinical grounds with tissue confirmation such as positive endomyocardial biopsy, severe ventricular arrhythmia, more than second degree atrioventricular block, and echocardiographically proven ventricular dysfunction. Among these patients with cardiac complications, abnormal myocardial uptake of FDG were observed in all (100%), which confirms significantly higher frequency compared to 67Ga scintigraphy (50%) (abnormality of 99mTc-MIBI SPECT were observed in 80%). Although abnormal FDG accumulations were observed in region with decreased uptake of 99mTc-MIBI in many cases, localization of regional abnormality of each tracer was frequently independent. This discrepancy may reflect inflammatory and degenerative process of myocardium in cardiac sarcoidosis. 18F-FDG PET is thought to be a useful noninvasive method in detecting cardiac involvement of sarcoidosis and may provide a useful information on the activity of the disease.

Cardiac sympathetic activity estimated by 123I-MIBG myocardial imaging in patients with dilated cardiomyopathy after beta-blocker or angiotensin-converting enzyme inhibitor therapy

Impaired cardiac sympathetic activity can be evaluated by 123I-metaiodobenzylguanidine (MIBG) imaging.

METHODS

We studied the significance of MIBG imaging for 24 patients (age 58+/-12 y) with dilated cardiomyopathy (DCM). We compared 12 patients (group A) treated with metoprolol (dose from 30-60 mg/d) with 12 patients treated with angiotensin-converting enzyme (ACE) inhibitors. Patients were studied before treatment, after 5 mo of treatment (only in group A) and after 1 y of treatment. Cardiac MIBG uptake was assessed as the heart-to-mediastinum activity ratio (H/M) and total defect score (TDS) from anterior planar and SPECT MIBG images, which were acquired in 4 h after tracer injection. New York Heart Association (NYHA) class and left ventricular ejection fraction (LVEF) calculated by echocardiography were also assessed.

RESULTS

TDS decreased in both groups (in group A, from 30+/-7 through 23+/-9 to 18+/-10; P < 0.01, in group B, from 30+/-6 to 24+/-8; P < 0.01) and H/M was increased in both groups (in group A, from 1.87+/-0.31 through 2.03+/-0.28 to 2.14+/-0.29; P < 0.01, in group B, from 1.82+/-0.28 to 1.94+/-0.26; P < 0.05). But TDS and H/M were more improved in group A than in group B (P < 0.05). LVEF was significantly increased in only group A (from 38+/-6 through 43+/-8 to 49%+/-9%; P < 0.01). NYHA improved in both groups (in group A, from mean 2.5 through 2.1 to 1.8; P < 0.01, in group B, from mean 2.6 to 2.1; P < 0.05) but was more improved in group A than in group B (P < 0.05).

CONCLUSION

Cardiac function, symptom and cardiac sympathetic activity evaluated by MIBG images improved after the beta-blocker therapy more than with the treatment that used ACE inhibitors.

Involvement of growth factor receptor-bound protein-2 in rat hepatocyte growth

Growth factor receptor-bound protein-2 (GRB-2) is a protein linking receptor tyrosine kinase and Sos (Son of Sevenless gene; Ras GDP/GTP exchange protein), leading to activation of the Ras-mitogen-activated protein kinase (MAPK) cascade. So far, it remains unclear how GRB-2 plays a role in signal transduction pathways evoked by hepatotrophic factors. This study was attempted to evaluate the involvement of GRB-2 in signalling in rat hepatocyte growth. Using rat cultured hepatocytes stimulated by hepatotrophic factors and regenerating livers after partial hepatectomy (PH) we examined GRB-2-mediated linkage of hepatotrophic factor receptors to signal transducing molecules such as Sos or dynamin-II by immunoprecipitation and western blot analysis. In primary cultured hepatocytes stimulated with hepatocyte growth factor (HGF) or epidermal growth factor (EGF), GRB-2 linked HGF receptor or EGF receptor, respectively, to Sos which activated the mitogen-activated protein kinase (MAPK) cascade. In contrast, in primary cultured hepatocytes stimulated with insulin, GRB-2 linked insulin receptor substrate-1 (IRS-1) to dynamin-II as well as Sos. In the early phase after PH, GRB-2 activated the Ras-MAPK cascade by linking HGF receptor, IRS-1, or EGF receptor to Sos. In the late phase after PH, a complex of IRS-1-GRB-2 associated with dynamin-II, indicating that GRB-2 may transduce signals from IRS-1 to dynamin-II. We conclude that GRB-2 may play a role in transmitting signals from hepatotrophic factors to not only MAPK but also to other signalling pathways in hepatocyte growth.

[Prognostic significance of loss of heterozygosity in breast cancer]

Loss of heterozygosity (LOH) was analyzed in 113 cases of sporadic breast cancer using 35 microsatellite markers on 20 chromosomes. LOH was frequently seen in 17p (44%), 16q (31%), 17q (29%) and 13q (23%). Individual patients were scored according to the incidence of LOH at the above four chromosomal markers; with no LOH as 1, with one or two LOH as 2, and with three of four LOH as 3. A high LOH score was well associated with high histological grade (p = 0.019) and a significantly poor prognosis (p = 0.0035). These data suggest that accumulation of LOH occurs at a later stage of breast cancer progression, and that the LOH score may be a useful prognostic marker of breast cancer.

The Clinical Value of Microsatellite Instability and a Loss in Heterozygosity in Sporadic Breast Cancers

We analyzed loss of heterozygosity (LOH) and microsatellite instability (MI) in 108 cases of sporadic breast cancers using 22 microsatellite markers on 12 chromosomes. LOH was frequently seen in 1p(13%), 6p(18%), 8p(11%), 11p(18%), 13q(21%),16q(31%), 17p(44%) and 17q(29%). Individual patients were scored according to the degree of LOH at the above eight chromosomal markers. Patients with no LOH were scored as 1, patients with one to three LOH were scored as 2, and patients with four or more LOH were scored as 3. A high LOH score correlated with a high histological grade (p=0.019) and a poor prognosis (p=0.0035). Eleven(10.2%) of 108 patients with breast cancer showed MI, with 6 cases showing MI at a single locus and 5 at multiple loci. Of the 11 MI-positive patients only one had lymph node involvement(p=0.015), none had histological grade 3 disease, and MI-positive patients tended to have a better prognosis than MI-negative ones. These data suggest that MI may be an early event in mammary tumorigenesis, and that LOH occurs at a later stage. The LOH score may be a useful prognostic marker of operable breast cancer.

[Usefulness of 201Tl/123I-BMIPP myocardial SPECT to evaluate myocardial viability and area at risk in acute myocardial infarction--comparison with 201Tl/99mTc-PYP dual SPECT]

To evaluate the area at risk and the myocardial viability of acute myocardial infarction (AMI), we compared rest 123I-beta-methyl iodophenyl pentadecanoic acid (123I-BMIPP) and 201Tl myocardial SPECT with 201Tl/99mTc-PYP dual SPECT (D-SPECT) in 65 patients (mean age 64 +/- 11 years) with AMI. D-SPECT was performed in 3 to 5 days, 123I-BMIPP myocardial SPECT in 5 to 7 days, and left ventriculography on 1 month after onset of AMI. Furthermore, 201Tl/123I-BMIPP myocardial SPECT and left ventriculography were performed on 4 months after onset of AMI. The area which showed the reduced 123I-BMIPP uptake was larger than that showed the accumulation of 99mTc-PYP. The improvement of regional wall motion on 4 months after onset of AMI tended to be more closely correlated with the existence of discrepancy zone between 201Tl and 123I-BMIPP uptake than that of overlap zone between 201Tl and 99mTc-PYP uptake in acute period. We conclude that 201Tl/123I-BMIPP myocardial SPECT is more useful to evaluate the area at risk and myocardial viability of AMI than D-SPECT.