Possibility of Differential Diagnosis of Small Polypoid Lesions in the Gallbladder Using FDG-PET

Purpose: We discuss three cases of patients with small polypoid lesions of gallbladder in which we successfully differentiated the malignancy or benignity preoperatively using positron emission tomography (PET) scanning with 18F-labelled deoxyglucose (FDG).Methods and Results: The first case involves a 47-year-old woman who had a 15 x 10 mm polypoid lesion of the gallbladder. FDG-PET was performed and revealed no FDG uptake. The histopathological diagnosis was a cholesterol polyp. The second case is a 56-year-old woman who had a 22 x 8 mm polypoid lesion in the neck of the gallbladder and wall-thickening of the fundus. FDG-PET was performed and no FDG uptake was found. The postoperative diagnosis was pseudo-tumorous sludge in the neck and adenomyomatosis of the fundus. The third case is a 77-year-old man who had a 15 x 15 mm polypoid lesion in the gallbladder. PET revealed a focus of FDG uptake at the site of the gallbladder. The histopathologic diagnosis was adenocarcinoma. Focal FDG uptake was the sole indicator of a malignant tumor of the gallbladder.Conclusions: FDG-PET may become one of the most useful tools for the accurate preoperative diagnosis of gallbladder carcinoma.

An improved rapid procedure for fluorescence in situ hybridization that is applicable to intraoperative cancer cytodiagnosis

Fluorescence in situ hybridization (FISH) is among the most simple and useful methods for detecting numerical and structural aberration of chromosomes but it requires 12-24 h to complete. We devised a rapid FISH method that can be performed within 2 h. Here we describe the technique, which we have found to be extreme simple and as sensitive and specific as standard FISH, making it highly suitable for clinical use.

Outcome of prophylactic radical lymphadenectomy with gastrectomy in patients with early gastric carcinoma without lymph node metastasis

BACKGROUND

Prophylactic extended lymphadenectomy with gastrectomy may prolong survival in patients with early gastric carcinoma without lymph node metastasis. However, the therapeutic value of extensive lymphadenectomy in patients with early gastric carcinoma remains controversial.

METHODS

The authors retrospectively analyzed 423 patients with early gastric carcinoma without lymph node metastasis who underwent gastrectomy and did not die of other diseases to evaluate the effect of prophylactic extended lymphadenectomy on postoperative survival. The postoperative survival rate of patients who underwent prophylactic extended lymphadenectomy was compared with that of patients who underwent prophylactic limited lymphadenectomy.

RESULTS

Although extended lymphadenectomy did not appear to improve the postoperative survival rate of patients with mucosal tumors, it did improve the postoperative survival rate of patients with submucosal tumors. Whether prophylactic extended lymphadenectomy was performed significantly affected outcome in patients with early gastric carcinoma who had submucosal tumors without regional lymph node metastasis.

CONCLUSIONS

Extensive lymphadenectomy with gastrectomy should be performed to prolong the survival of the patients with submucosal tumors.

Correlation between angiographically assessed vascularity and blood flow in hepatic metastases in patients with colorectal carcinoma

BACKGROUND

The correlation between vascularity and blood flow in hepatic metastases in patients with colorectal carcinoma was studied in 22 metastatic liver tumors.

METHODS

Hepatic metastases were categorized into Grades A-C, in order of increasing vascularity, as determined by hepatic angiography. Of the 22 metastatic liver tumors from 15 patients that showed on angiography, 5 tumors had slightly increased tumor vascularization (Grade A), 10 tumors had vascularization similar to normal (Grade B), and 7 tumors showed decreased vascularization relative to liver parenchyma (Grade C). Blood flow in these metastatic liver tumors was calculated quantitatively by positron emission tomography (PET) scanning using the C(15)O(2) steady-state method and the H(2)(15)O dynamic method.

RESULTS

Using the H(2)(15)O method, blood flow value in Grade A tumors was 52.9 +/- 17.0 mL per 100 g per minute (mean +/- standard error), that in Grade B tumors was 35.7 +/- 3.8 mL per 100 g per minute, and that in Grade C tumors was 31.7 +/- 6.6 mL per 100 g per minute.

CONCLUSIONS

A significant difference was found between blood flows in Grade A metastatic liver tumors and Grade B or C tumors (P < 0.002). There was no significant difference between blood flows in Grade B and C tumors. PET scan quantification results were almost parallel with the angiographic results. Even Grade C tumors had sufficient blood flow, about 32 mL per 100 g per minute on dynamic PET scans. These findings suggest that blood flow in hepatic metastases from colorectal carcinoma is greater than generally is believed.

A reverse flow-metabolism mismatch pattern: a new marker of viable myocardium with greater contractility during dobutamine stress than myocardium with a flow-metabolism mismatch pattern

Few studies have investigated the contractility of myocardium with a reverse flow-metabolism pattern; that is, greater uptake of nitrogen- 13-ammonia (NH3) than fluorine- 18-fluorodeoxyglucose (FDG) on positron emission tomography (PET). This study examined the contraction thickening represented by count increase in ECG-gated FDG-PET of myocardium with a reverse flow-metabolism pattern during low-dose dobutamine stress. Fifty-four patients with myocardial infarction were studied. Relative NH3 and FDG uptake (%NH3, %FDG) and %count increase were measured in 216 apical and 216 lateral segments on ECG-gated FDG-PET. The %count increase during low-dose dobutamine stress was greater in myocardium with a reverse flow-metabolism mismatch pattern than in myocardium with a flow-metabolism mismatch pattern (35.9+/-25.7% vs 24.6+/-15.9%, p=0.0221 in apical segments, and 38.4+/-22.6% vs 27.6+/-18.4%, p=0.0040 in lateral segments) despite smaller %FDG. A reverse flow-metabolism mismatch pattern should be noted as a new marker of viable myocardium with greater contractility during dobutamine stress than myocardium with a flow-metabolism mismatch pattern.

Relationships among serum triacylglycerol, fat pad weight, and lipolysis in iron-deficient rats

We studied the relationships among serum triacylglycerol (TG), fat pad weight, and lipolytic response to norepinephrine (NE) in iron-deficient rats. We used male Sprague-Dawley International Golden Standard rats. The rats were randomly divided into four groups: two iron-adequate groups for 1 week (1A) and 5 weeks (5A), and two iron-deficient groups for 1 week (1D) and 5 weeks (5D), based on the AIN-93G diet. Iron-deficient treatment caused a significant decrease in hemoglobin (Hb) and hematocrit (Hct) values and an increase in relative heart weight in 1D and 5D rats. Although serum TG was not affected by the 1-week iron-deficient treatment, it was significantly increased by 5-week iron-deficient treatment. The 1-week iron-deficient treatment significantly decreased the relative weight of the retroperitoneal fat pads, but not that of the epididymal fat pads. On the other hand, the 5-week iron-deficient treatment significantly decreased the relative weight of both fat pads; the degree of decrease was 41% and 32% for retroperitoneal and epididymal fat pads, respectively. Basal lipolysis significantly decreased in the epididymal adipocytes from 1D rats, whereas lipolytic response to NE markedly increased. No effect due to the 5-week treatment on basal lipolysis was observed in either retroperitoneal or epididymal adipocytes. In addition, lipolytic response to NE significantly increased in the retroperitoneal, but not the epididymal adipocytes. These results demonstrate that the effects of an iron-deficient diet on fat pad weight are different, depending on the duration of the treatment and the location of fat pads. In addition, iron deficiency-caused hypertriacylglycerolmia may be predominantly related to the increase in lipolysis in retroperitoneal rather than in epididymal adipocytes. The data further show that the increase in lipolysis of epididymal adipocytes occurs in the earlier stage prior to a severe iron-deficient state.

Efficient induction of peptide-specific cytotoxic T lymphocytes by LPS-activated spleen cells

Lipopolysaccharides of gram-negative bacteria are potent activators of B cells, dendritic cells and monocytes/macrophages. We have investigated the use of LPS-activated spleen cells as antigen-presenting cells to induce CD8+ cytotoxic T lymphocytes in vivo that are reactive to MHC class I binding peptides. Compared with resting spleen cells, CTL induction was more efficient and less variable for different peptides with LPS-activated spleen cells. Cytotoxic responses were specific for the immunized peptides and contained high affinity CD8+ T cells. The removal of dendritic cells and monocytes/macrophages by Sephadex G10 column did not show profound effects on CTL induction, indicating that B-cell blasts were largely responsible. This easily accessible method should facilitate the screening of MHC class I binding peptides to determine whether or not the host's T-cell repertoire contains reactive T cells.

Antitumor effect of alpha-galactosylceramide (KRN7000) on spontaneous hepatic metastases requires endogenous interleukin 12 in the liver

Hepatic metastasis is a major clinical problem in cancer treatment. We examined antitumor activity of alpha-galactosylceramide (KRN7000) on mice with spontaneous liver metastases of reticulum cell sarcoma M5076 tumor cells (spontaneous metastasis model). In this model, all mice that were s.c. challenged with one million tumor cells developed a solid s.c. mass by day 7 and died of hepatic metastases. In the current study, we administered 100 microg/kg of KRN7000 to the model mice on days 7, 11, and 15. This treatment suppressed the growth of established liver metastases and resulted in the prolongation of survival time. Fluorescence-activated cell sorter analysis of phenotypes of spleen cells, hepatic lymphocytes, and regional lymph node cells around the s.c. tumor revealed that CD3+NK1.1+ (NKT) cells increased in hepatic lymphocytes of the KRN7000-treated mice. Cytotoxic activity and IFN-gamma production of hepatic lymphocytes were augmented in comparison with those of spleen cells and regional LN cells. At the same time, interleukin (IL)-12 production of hepatic lymphocytes was markedly enhanced. Neutralization of IL-12 using a blocking monoclonal antibody diminished the prolonged survival time. These results showed that the in vivo antitumor effects of KRN7000 on spontaneous liver metastases were dependent on the endogenous IL-12 production, where NKT cells in the liver are suggested to be involved. Adjuvant immunotherapy using KRN7000 could be a promising modality for the prevention of postoperative liver metastases.

A role for p27/Kip1 in the control of cerebellar granule cell precursor proliferation

During development, control of proliferation of neuronal precursor cells plays a crucial role in determining the number of neurons. Proliferation is driven by mitogens, but how it is terminated remains a mystery. In this study, we examined the role of cyclin-dependent kinase inhibitors in the control of proliferation of cerebellar granule cell precursors (GCPs). Among the inhibitors we examined, only p27/Kip1 (p27) was expressed at significant levels in cells of the granule cell lineage in the developing and adult cerebellum. In developing cerebella, p27 was expressed in the external germinal layer (the deeper regions), the molecular layer, and the granule layer. In adult cerebella, p27 was expressed in the cells of the granule layer. We isolated and purified GCPs from cerebella of developing mice and examined their bromodeoxyuridine (BrdU) uptake and p27 expression at various times. We found that there was an inverse correlation between BrdU uptake and p27 expression. Even in the presence of saturating amounts of Sonic hedgehog, a potent mitogen, the cells eventually stopped dividing and differentiated, expressing p27 strongly. We also examined mice in which one or both copies of the p27 gene have been inactivated by targeted gene disruption and found that their cerebella were larger than those of wild-type mice. In cell cultures, GCPs prepared from p27-deficient mice showed enhanced proliferation compared with GCPs from wild-type mice. Taken together, these results suggest that there is an intracellular mechanism that stops GCP division and causes GCPs to differentiate and that p27 is part of this mechanism.

Effects of metabolically ischemic, but viable, myocardium on QT dispersion in patients with acute myocardial infarction: a study with resting I-123-BMIPP/thallium-201 myocardial single-photon emission computed tomography

In chronic Q-wave myocardial infarction, QT dispersion is closely correlated with infarct size, but this correlation has not been evaluated for acute myocardial infarction (AMI). The effects of abnormal fatty acid metabolism on QT dispersion were examined in 123 patients with AMI who underwent resting iodine-123-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/thallium-201(201Tl) myocardial single photon emission computed tomography (SPECT) and electrocardiographic analysis in the subacute phase. The relationship between BMIPP and 201Tl was defined as match when the total defect score for BMIPP was equal to or smaller than that for 201Tl, and as mismatch when the total defect score for BMIPP was larger than that for 201Tl. Twenty-six patients (21%) demonstrated BMIPP-201Tl match and 97 (79%) demonstrated mismatch. Infarct size was closely correlated with QT dispersion (r=0.67, p<0.001) in patients with BMIPP-201Tl match, but weakly correlated (r=0.30, p<0.005) in patients with BMIPP-201Tl mismatch. For small infarctions, QT dispersion was significantly larger in patients with BMIPP-201Tl mismatch than in those with BMIPP-201Tl match (62+/-24 ms vs 41+/-18 ms, p=0.03), but did not differ between the 2 groups for large infarctions. This study shows that QT dispersion is influenced by infarct size and by the presence of metabolically ischemic but viable myocardium in patients with AMI.

A long-term survival case of multiple hepatocellular carcinoma with metachronous lymph node metastasis

A long-term survival case of multiple hepatocellular carcinoma (HCC) with metachronous metastasis to a lymph node is reported. The patient, a 66-year-old woman, had two primary HCC nodules, one each in the left and right hepatic lobes, which were resected. She developed a lymph node lesion and a secondary HCC 45 and 62 months after the first operation, respectively. She has been well for the 7 years since the first operation despite undergoing hepatic resection for HCC twice as well as lymph node resection. Clonal analysis, based on the methylation pattern of the X chromosome-linked androgen receptor gene, suggested that the two primary tumors were multicentric and that the lymph node lesion had arisen by metastasis from the primary tumor in the right hepatic lobe.

An automated prediction of MHC class I-binding peptides based on positional scanning with peptide libraries

Specificities of three mouse major histocompatibility complex (MHC) class I molecules, Kb, Db, and Ld, were analyzed by positional scanning using combinatorial peptide libraries. The result of the analysis was used to create a scoring program to predict MHC-binding peptides in proteins. The capacity of the scoring was then challenged with a number of peptides by comparing the prediction with the experimental binding. The score and the experimental binding exhibited a linear correlation but with substantial deviations of data points. Statistically, for approximately 80% of randomly chosen peptides, MHC-binding capacity could be predicted within one log concentration of peptides for a half-maximal binding. Known cytotoxic T-lymphocyte epitope peptides could be predicted, with a few exceptions. In addition, frequent findings of MHC-binding peptides with incomplete or no anchor amino acid(s) suggested a substantial bias introduced by natural antigen processing in peptide selection by MHC class I molecules.

Long-term benefit of extended lymphadenectomy with gastrectomy in distally located early gastric carcinoma

BACKGROUND

Extended lymphadenectomy performed with gastrectomy has been reported to prolong survival of patients with early gastric cancer. However, some authors question the value of extensive lymphadenectomy in these patients, especially since much recent discussion of patient quality of life after gastrectomy has favored less invasive operations.

METHODS

We retrospectively analyzed 485 patients who had undergone gastrectomy for early cancer in order to evaluate the effect of extended versus limited lymphadenectomy on postoperative survival. Various prognostic factors were examined for patients whose tumors were located in the distal third of the stomach.

RESULTS

Although extended radical lymphadenectomy did not prolong postoperative survival when early gastric cancer was located in the middle or proximal third of the stomach, it did when the tumor occupied the distal third.

CONCLUSIONS

Performance of extended radical lymphadenectomy was a significant prognostic factor for early gastric cancer patients when tumors were located in the distal third of the stomach.

Amplification and over-expression of the AIB1 nuclear receptor co-activator gene in primary gastric cancers

Our analysis of chromosomal aberrations in primary gastric cancers using comparative genomic hybridization has revealed novel, high and frequent copy number increases in the long arm of chromosome 20, indicating that this region contains novel amplified genes involved in gastric cancer progression. AIB1, a member of the steroid receptor co-activator-1 family, has been cloned on 20q12 as a candidate target gene for this amplification in human breast cancers. In this study, we examined the numbers of AIB1 copies as well as their expression and relation to clinico-pathological features in 72 primary gastric cancers. AIB1 amplification was observed in 7% and over-expression in 40% of the specimens. AIB1 amplification always coincided with its over-expression, but several cases showed AIB1 over-expression without amplification, suggesting that expression of AIB1 is regulated not only by gene amplification but also by other mechanisms, such as transcriptional activation, in human gastric cancer. Gastric cancers with AIB1 amplification showed extensive lymph node metastases, liver metastases and poorer prognosis compared to those without amplification. Our results suggest that amplification and over-expression of AIB1 are likely to increase the number of malignant phenotypes of gastric cancers and that it can be expected to be useful as a marker of poor prognosis.

Class switch recombination of the chicken IgH chain genes: implications for the primordial switch region repeats

In mammals and the amphibian, Xenopus, isotypes of antibodies have been shown to be changed through class switch recombination within the IgH chain gene locus. Here, we identified switch (S) repetitive sequences in the 5' introns of the Ig C(mu) and C(gamma) genes of the chicken. The S(mu) region is composed of two homologous regions, S(mu)1 and S(mu)2. The S(mu)1 region is an upstream 3.7 kb sequence composed of 37 repeats of a consensus sequence containing tandem repeats of the decamer ACCAGTATGG. The S(mu)2 region is a downstream 1.4 kb sequence consisting of simple tandem repeats of a decamer CCCAGTACAG. The S(gamma) region contains repeats of the decamer TATGGGGCAG. Analysis of chicken IgG-producing hybridomas revealed that the C(mu) gene was deleted from the chromosome by the recombination occurring between the S(mu) and S(gamma) regions. Recombination breakpoints at the C(mu) gene of splenocytes from an immunized chicken were scattered around the S(mu) region and two such breakpoints, the precise position of which were determined, were located within possible hairpin loop structures at the palindromic sequence of S(mu)1. A primordial palindromic sequence from which the prevalent switch repeat motifs of mammals, chickens and amphibians may have diverged is presented.

Frequent association of 22q11.2 deletion with tetralogy of Fallot

Chromosome 22q11.2 deletion causes DiGeorge syndrome, velocardiofacial syndrome, conotruncal anomaly face syndrome with tetralogy of Fallot (TOF), and sporadic or familial TOF. To determine the prevalence and clinical importance of the 22q11.2 deletion in TOF, a series of 212 Japanese TOF patients was studied. The type of pulmonary blood supply, which may lead to various clinical outcomes, and other additional anomalies were evaluated clinically. The 22q11.2 deletion was diagnosed by fluorescence in situ hybridization with N25 and TUPLE1 probes. Of the 212 patients examined, 28 (13%) had a 22q11.2 deletion, the frequency being higher than that in TOF patients with trisomy 21. The prevalence of the deletion in TOF patients with pulmonary atresia (PA) plus major aortico-pulmonary collateral arteries (MAPCA) was significantly higher than the value in patients with PA plus patent ductus arteriosus (PDA) (P = 0.04) or with pulmonary stenosis (PS) (P < 0.0001). All 28 patients with 22q11.2 deletion had one or more extracardiac abnormalities. Four of 9 patients with the 22q11.2 deletion and TOF-PA-MAPCA suffered from bronchomalacia, while none of 19 patients with TOF-PA-PDA or TOF-PS manifested bronchomalacia (P = 0.006). These results indicate that 22q11.2 deletion is the most frequent cause of syndromic TOF, especially for TOF-PA-MAPCA, and bronchomalacia is the clinically most important associated anomaly in TOF-PA-MAPCA patients.

Intraperitoneal injection of dextran sulfate as an anti-adherent drug for the prevention of peritoneal metastasis of cancer shows low toxicity in animals

Intraperitoneal dextran sulfate with a mean molecular weight of 5 x 10(5) has been developed for use in an anti-adherent therapy against peritoneal carcinomatosis. The present study examined acute toxicity of i.p. injection of dextran sulfate in mice and rabbits. The 10, 50 and 90% lethal dose values are 0.213 (0.146-0.252), 0.336 (0.291-0.405) and 0.530 mg/g (0.431-0.873 mg/g: 95% confidence interval) in mice, respectively. These are markedly larger than the efficacious dose of 0.005-0.01 mg/g obtained previously. Death or symptoms of intoxication were seen within 3 days after administration of toxic doses. Rabbits received i.p. injection of dextran sulfate at 0.02 mg/g, which was close to the efficacious dose. At 2, 4, 6, 8 and 13 days after administration, blood was taken for biochemical and hematological analyses. Dextran sulfate at 0.02 mg/g induced no remarkable abnormal findings. These results suggest that the i.p. dextran sulfate is safe as an anti-adherent agent against peritoneal metastasis of cancer.

Genomic alterations in primary gastric cancers analyzed by comparative genomic hybridization and clinicopathological factors

BACKGROUND/AIMS

Genetic changes during the oncogenesis and progression of gastric cancer remain unclear. The aim of our study was to analyze chromosomal aberrations in primary gastric cancers.

METHODOLOGY

Using comparative genomic hybridization, we screened 47 primary gastric cancers for changes in the number of copies of DNA sequences.

RESULTS

Gains of chromosome arms 20q (55%), 20p (36%), 17q (32%), 19q (30%) and 16p (30%), and losses of chromosome arms 4q (40%), 17p (40%), 5q (38%), 18q (30%) and 4p (28%) were detected most frequently. In addition, a high level of amplification was observed at 3q21 (2%), 6p21 (4%), 7q31 (6%), 8q23-24 (2%), 19q12-13 (2%), and 20q13 (2%). Among these alterations, the gain of 20q was the most frequent change. We then compared these changes with clinicopathological factors and identified signet ring cell carcinomas in 6 cases. Our study demonstrated no amplification of chromosome 20q in signet ring cell carcinoma in contrast to that in the other histologic types of gastric cancer.

CONCLUSIONS

Our findings may be related to the morphologic and clinical features of signet ring cell carcinoma, and several oncogenes mapped on 20q may play an important role as determinants of the clinical and histologic features of gastric cancer.

Graded neuromuscular transmission in the heart of the isopod crustacean Ligia exotica

We present several lines of evidence for the occurrence of graded synaptic transmission in addition to impulse-mediated transmission at the neuromuscular junction between cardiac ganglion (CG) neurones and the myocardium in the isopod crustacean Ligia exotica. In the heart of adult Ligia exotica, the CG acts as a primary pacemaker for the heartbeat by generating periodic bursts of impulses and entrains the myogenicity of the myocardium via impulse-mediated excitatory junctional potentials. When impulse generation was blocked by tetrodotoxin (TTX; 50 nmol l(−)(1)), the CG neurones and the myocardium periodically exhibited synchronized slow depolarizing potentials. The association between the slow depolarizing potentials in the neurone and the myocardium was eliminated by application of Joro spider toxin (JSTX), a specific glutamate antagonist. When the CG neurone was made quiescent by a higher dose of TTX (1.0 micromol l(−)(1)), sinusoidal current injected into the CG neurone induced similar sinusoidal membrane potential responses in the myocardium. The sinusoidal muscle responses were eliminated by application of either JSTX or low-Ca(2+) saline. Under voltage-clamp conditions, the myocardium exhibited periodic inward current responses to sinusoidal current stimuli applied to the CG neurone. The reversal potential for the current response of the myocardium was similar to that of the impulse-mediated excitatory junctional current (EJC). Extracellular macropatch recordings of EJCs made at the neuromuscular junctional site revealed the spontaneous appearance of miniature EJCs asynchronous with the CG spikes in addition to large spike-evoked EJCs. The miniature EJCs were present in saline containing TTX, and their frequency was strongly affected by the slow membrane potential change in the CG neurone. These results suggest that the CG neurones drive the myocardium by graded neuromuscular transmission in addition to impulse-mediated transmission in the heart of Ligia exotica.

Effects of preinfarction angina on myocardial injury in patients with acute myocardial infarction: a study with resting 123I-BMIPP and 201T1 myocardial SPECT

METHODS

Recent studies have suggested that patients with preinfarction angina have smaller infarcts and a better in-hospital outcome than those without angina. The mechanisms responsible for limitation of infarct size in the presence of preinfarction angina are unclear. We examined the effects of preinfarction angina on myocardial injury in patients with the first acute myocardial infarction with resting 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) 201TI myocardial scanning performed within 1 mo of infarction.

RESULTS

Of 136 patients tested, 48 (35%) had preinfarction angina within 72 h before infarction, whereas 88 (65%) did not. BMIPP and 201TI defects were scored in 9 segments of the left ventricle (0 = normal, 1 = mild defect, 2 = moderate defect, 3 = severe defect, and 4 = no uptake). The total defect score was defined as the sum of the defect scores. There was no significant difference in percentage diameters of stenoses of infarct-related arteries, collateral circulation, total defect scores for BMIPP, or 201TI between the groups with and without preinfarction angina. However, the ratio of total defect score for 201TI to that for BMIPP was significantly smaller for patients with than for those without preinfarction angina (0.64 +/- 0.21 versus 0.74 +/- 0.25, respectively; P = 0.007).

CONCLUSION

Preinfarction angina did not affect the areas at risk in acute myocardial infarction, as shown by BMIPP defect, but decreased necrotic myocardium in the areas at risk, as shown by 201TI defect, and increased metabolically damaged but viable myocardium, as shown by BMIPP and 201TI mismatch through unidentified mechanisms other than collateral circulation (e.g., ischemic preconditioning).

Molecular detection of disseminated cancer cells in the peripheral blood of patients with gastric cancer

This study was designed to determine whether circulating cancer cells in patients with gastric cancer can be identified by a RT-PCR method and to assess the clinical significance of the hematogenic dissemination of cancer cell in gastric cancer patients. A total of 41 patients with gastric cancer were enrolled in this study. Peripheral blood samples from 41 patients with gastric cancer were analyzed for CEA mRNA using RT-PCR. Of the 36 patients undergoing radical gastrectomy, eight had a positive CEA mRNA signal in their peripheral blood before the gastrectomy. In four patients, the CEA mRNA signal was negative, positive and then negative again, before, during and after the surgery, respectively. Of the five inoperable patients with peritoneal metastasis, four had positive CEA mRNA signals despite no metastasis in any other organs. The RT-PCR method is a useful diagnostic modality to determine patient selection for chemotherapy after surgery.

Reverse redistribution of thallium-201 myocardial single photon emission tomography and contractile reserve

The present study investigated the contractile reserve of myocardium exhibiting reverse redistribution (RRD) of thallium-201 (201Tl) after acute myocardial infarction. Forty patients experiencing their first acute myocardial infarction underwent resting 201Tl single-photon emission computed tomography (SPECT) and low-dose (5-10 microgxkg(-1)xmin(-1)) dobutamine stress echocardiography (DSE) within 4 weeks after the onset of infarction. The left ventricle was divided into 13 segments for analysis. The severity of defects in 201Tl SPECT and the extent of wall motion abnormality in DSE were visually assessed and scored. The sum of each defect score and wall motion score of infarct-related segments were defined as total defect score (TDS) and total wall motion score (TWM), respectively. Quantitative analysis of 201Tl uptake was also performed. Resting 201Tl SPECT revealed RRD in 16 patients (group RRD), fixed defect (FIX) in 23 patients (group FIX), and redistribution in one. There was a significant difference in improvement of TWM between rest and stress in TWM in both the RRD and FIX groups (p<0.0001, each case). The improvement of TWM with dobutamine was significantly greater in RRD than in FIX (1.6+/-1.0 vs 0.6+/-0.7, p=0.001). There was a positive correlation between the magnitude of RRD and improvement of TWM with dobutamine (r=0.48, p=0.002). Myocardium exhibiting RRD on 201Tl SPECT in patients with acute myocardial infarction has greater contractile reserve than that exhibiting a fixed defect.