P1478 Evaluation of reversibility of alcoholic cardiomyopathy using doubaimine stress echocardiography

Alcoholic cardiomyopathy (CM) is known as a reversible CM. Appropriate medications with cessation of alcohol may lead to full recovery of chamber size and contractility. But there is not much information about morphologic and hemodynamic changes over the course of treatment, and predictors of reversibility. We experienced the patient with alcoholic CM who was admitted with heart failure and recovered over 1 year and 5 months. He consumed daily 180g alcohol for 6 months before admission. On initial echocardiography, left atrial (LA) dimension, left ventricular (LV) systolic dimension (SD) and diastolic dimension (DD), inferior vena cava (IVC) size, and ejection fraction (EF) were 50 mm, 69 mm, 78 mm, 27 mm and 22%, respectively. Doppler examination revealed a restrictive pattern in tansmitral flow, and a systolic peak velocity/diastolic peak velocity (S/D) ratio of less than 1 in pulmonary vein flow (PVF). Pressure gradient through tricuspid regurgitation was 29 mmHg. Coronary angiogram confirmed no significant stenosis. Within 1 week after medications, LVEF increased mainly by decrease of enlarged LVSD which might be partly caused by volume overload, evidenced by respiratory variation of transmitral flow. On 8th day, we performed dobutamine stress echocardiography (DSE) to evaluate reversibility because LVEF slightly decreased despite decrease of LVDD. During dobutamine infusion, both LVDD and LVSD decreased along with increase of LVEF according to dose escalation. From 1 to 2 months, LVEF slightly increased with decrease of LVDD and LVSD. Afterwards, LVEF was normalized mainly with decrease of LVSD, and LVEF was completely normalized at 1 year and 5 month after initiation of treatment. Initial increase of LVEF might reflect decrease of LVSD by relief of volume overload rather than improving LV contractility. Based on this observation of serial change of chambers and LVEF, we speculate that increased LV wall tension, which is induced by increase of preload as a compensating mechanism for increasing stroke volume, might aggravate LVEF in later stage of heart failure with reduced EF. The sequence of normalization in chamber size was IVC, and then LA, and then LVDD. Transmitral flow as an indicator of diastolic dysfunction changed from restrictive (transiently existed only for 1 week) to abnormal relaxation pattern (no change since that time). PVF pattern showed S/D ratio < 1 until 1 week, and then triphasic pattern at 1 month, finally biphasic pattern at 8 month after initiation of medications. We observed a serial change of echocardiographic findings in patient with alcoholic CM, which might provide an insightful information to understand reverse of LV or LA remodeling associated with hemodynamic parameters, and DSE might be helpful to evaluate reversibility of LV systolic function and convince patients who are reluctant to medications.

Genomic Heterogeneity as a Barrier to Precision Medicine in Gastroesophageal Adenocarcinoma

Gastroesophageal adenocarcinoma (GEA) is a lethal disease where targeted therapies, even when guided by genomic biomarkers, have had limited efficacy. A potential reason for the failure of such therapies is that genomic profiling results could commonly differ between the primary and metastatic tumors. To evaluate genomic heterogeneity, we sequenced paired primary GEA and synchronous metastatic lesions across multiple cohorts, finding extensive differences in genomic alterations, including discrepancies in potentially clinically relevant alterations. Multiregion sequencing showed significant discrepancy within the primary tumor (PT) and between the PT and disseminated disease, with oncogene amplification profiles commonly discordant. In addition, a pilot analysis of cell-free DNA (cfDNA) sequencing demonstrated the feasibility of detecting genomic amplifications not detected in PT sampling. Lastly, we profiled paired primary tumors, metastatic tumors, and cfDNA from patients enrolled in the personalized antibodies for GEA (PANGEA) trial of targeted therapies in GEA and found that genomic biomarkers were recurrently discrepant between the PT and untreated metastases. Divergent primary and metastatic tissue profiling led to treatment reassignment in 32% (9/28) of patients. In discordant primary and metastatic lesions, we found 87.5% concordance for targetable alterations in metastatic tissue and cfDNA, suggesting the potential for cfDNA profiling to enhance selection of therapy.Significance: We demonstrate frequent baseline heterogeneity in targetable genomic alterations in GEA, indicating that current tissue sampling practices for biomarker testing do not effectively guide precision medicine in this disease and that routine profiling of metastatic lesions and/or cfDNA should be systematically evaluated. Cancer Discov; 8(1); 37-48. ©2017 AACR.See related commentary by Sundar and Tan, p. 14See related article by Janjigian et al., p. 49This article is highlighted in the In This Issue feature, p. 1.

Use of supplemental anti-HBc testing of donors showing non-discriminating reactive results in multiplex nucleic acid testing

BACKGROUND AND OBJECTIVES

The Korean Red Cross began nucleic acid amplification testing (NAT) for HIV and HCV in February 2005, and added HBV NAT beginning in June 2012. The current NAT system utilizes a multiplex assay for simultaneous detection of HBV DNA, HCV RNA and HIV-1 RNA. For samples that are reactive in the multiplex assay, we do specific tests for each virus. However, there have been cases of non-discriminated reactive (NDR) results which appear to be the result of non-specific reactions or cross-contamination, although some cases are considered to arise from the presence of low levels of HBV DNA due to occult hepatitis B infection.

MATERIALS AND METHODS

We examined the incidence of NDR results in previous donations of some NAT-reactive donors. Additionally, for those donors with NDR results, we performed an HBV core antibody (anti-HBc) assay.

RESULTS

From November 2015 to March 2016, there were 408 NAT-reactive donors. Of these, nineteen HBV NAT-reactive donors showed a history of NDR results in the past donations. Seven donors showed NDR results more than once. Of 771 NDR donors, 362 (47·0%) were anti-HBc reactive.

CONCLUSION

The NDR donors had a substantially higher rate of anti-HBc reactivity than other blood donors indicating that some with anti-HBc reactivity represent donors with occult HBV. Therefore, the incorporation of an anti-HBc testing for NDR donors could improve blood safety testing for the Korean Red Cross.

Increased expression of bitter taste receptors in human allergic nasal mucosa and their contribution to the shrinkage of human nasal mucosa

OBJECTIVE

Bitter taste receptors (TAS2Rs) are expressed in the extraoral tissues, where they possess various physiological functions. This study is to characterize TAS2Rs expression in normal and allergic nasal mucosa and analyse nasal symptom after challenge with bitter tastes to evaluate their pathophysiological function in normal and allergic nasal mucosa.

METHODS

The expression levels of TAS2Rs (TAS2R4, 5, 7, 10, 14, 39, and 43) in nasal mucosa were investigated by real-time PCR, Western blot, and immunohistochemistry. The expression levels of TAS2Rs and Ca(2+) imaging in cultured epithelial cells were measured after stimulation with type 2 cytokines (IL-4, IL-5, and IL-13) or bitter tastes. Nasal symptoms in control subjects and allergic rhinitis patients using visual analogue score and acoustic rhinometry were evaluated before and after stimulation with bitter tastes. Vascular diameter of rat nasal septum was measured before and after treatment with bitter tastes.

RESULTS

TAS2Rs tested here were expressed in nasal mucosa where they were commonly distributed in superficial epithelium, submucosal glands, and endothelium. Their expression levels are increased in allergic nasal mucosa and up-regulated in cultured epithelial cells simulated with type 2 cytokines. After treatment with bitter tastes, intracellular Ca(2+) signalling was increased in cultured epithelial cells, and vascular constriction was found in rat nasal septum. Increased nasal patency was observed in human nasal mucosa without pain or sneezing.

CONCLUSION AND CLINICAL RELEVANCE

TAS2Rs are constitutively expressed in human nasal mucosa and their expression levels are increased in allergic nasal mucosa, where they could potentially contribute to shrinkage of normal and allergic nasal mucosa.

Gauging NOTCH1 Activation in Cancer Using Immunohistochemistry

Fixed, paraffin-embedded (FPE) tissues are a potentially rich resource for studying the role of NOTCH1 in cancer and other pathologies, but tests that reliably detect activated NOTCH1 (NICD1) in FPE samples have been lacking. Here, we bridge this gap by developing an immunohistochemical (IHC) stain that detects a neoepitope created by the proteolytic cleavage event that activates NOTCH1. Following validation using xenografted cancers and normal tissues with known patterns of NOTCH1 activation, we applied this test to tumors linked to dysregulated Notch signaling by mutational studies. As expected, frequent NICD1 staining was observed in T lymphoblastic leukemia/lymphoma, a tumor in which activating NOTCH1 mutations are common. However, when IHC was used to gauge NOTCH1 activation in other human cancers, several unexpected findings emerged. Among B cell tumors, NICD1 staining was much more frequent in chronic lymphocytic leukemia than would be predicted based on the frequency of NOTCH1 mutations, while mantle cell lymphoma and diffuse large B cell lymphoma showed no evidence of NOTCH1 activation. NICD1 was also detected in 38% of peripheral T cell lymphomas. Of interest, NICD1 staining in chronic lymphocytic leukemia cells and in angioimmunoblastic lymphoma was consistently more pronounced in lymph nodes than in surrounding soft tissues, implicating factors in the nodal microenvironment in NOTCH1 activation in these diseases. Among carcinomas, diffuse strong NICD1 staining was observed in 3.8% of cases of triple negative breast cancer (3 of 78 tumors), but was absent from 151 non-small cell lung carcinomas and 147 ovarian carcinomas. Frequent staining of normal endothelium was also observed; in line with this observation, strong NICD1 staining was also seen in 77% of angiosarcomas. These findings complement insights from genomic sequencing studies and suggest that IHC staining is a valuable experimental tool that may be useful in selection of patients for clinical trials.

Association of hypertension with small, dense low-density lipoprotein in patients without metabolic syndrome

A higher proportion of small, dense low-density lipoprotein (sdLDL) is known to be associated with a high prevalence of cardiovascular disease in association with metabolic syndrome (MS). Hypertension (HTN) is one of the known risk factors for MS. However, whether HTN is associated with sdLDL in patients without MS is not yet clear. The lipid profiles, including low-density-lipoprotein (LDL) subfractions, of 383 consecutive subjects were evaluated. The patients without MS consisted of 198 hypertensive patients (non-MS/HTN group) and 108 normotensive subjects (non-MS/non-HTN group). The peak and mean particle diameter of LDL were measured by gradient gel electrophoresis. Plasma total cholesterol, LDL cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride (TG), HDL cholesterol/Apo A1, LDL-C/ApoB and Apo(A1, B, CII and E) levels did not differ between the non-MS/non-HTN and non-MS/HTN groups. When analyzing LDL subfraction, the absolute amount of patterns A and B was not different between the non-MS/non-HTN and non-MS/HTN groups. Compared with the non-MS/non-HTN groups, the proportion of sdLDL was higher in the non-MS/HTN group (37.7% versus 39.9%, P=0.046), but not significant after adjustment of waist circumference, serum TG, age and statin usage. The proportion of sdLDL to total LDL was higher in hypertensive subjects, even those without MS, than in normotensive subjects. However, this difference of LDL subfraction in hypertensive patients is associated with higher waist circumference, higher serum TG, older age and more statin usage. This result suggests that HTN may contribute to atherosclerosis and endothelial dysfunction with associated risk factors that influence LDL size.

A new HLA-B*5124 variant, B*512402 allele, identified by sequence-based typing

A novel human leukocyte antigen-B allele, officially named B*512402, was identified in a Korean bone marrow donor. The B*512402 allele shows two nucleotide substitutions compared with B*512401 in exon 3 at codons 135 (GCG --> GCC) and 138 (ACC --> ACG) without any amino acid substitution.

Impact of hypertension on coronary artery spasm as assessed with intracoronary acetylcholine provocation test

Both hypertension and coronary artery spasm (CAS) are associated with endothelial dysfunction. Thus, a higher incidence of CAS is expected in hypertensive patients. We evaluated the impact of hypertension on CAS with intracoronary acetylcholine (ACh) provocation test. A total of 986 patients (685 hypertensive patients vs 301 normotensive patients) who underwent coronary angiography with ACh provocation test were enrolled. ACh was injected into the left coronary artery in incremental doses of 20, 50 and 100 microg min(-1). Significant CAS was defined as a transient >70% luminal narrowing with concurrent chest pain and/or ST-segment changes. Although the incidences of significant ACh-induced CAS were similar between hypertensive and normotensive patients (35.8 vs 39.2%, P=0.303), multivariate logistic analysis showed that hypertension was negatively associated with ACh-induced CAS (odds ratio: 0.70, 95% confidence interval: 0.51-0.94, P=0.020). The angiographic characteristics of ACh-induced CAS were similar between these two groups. Subgroup analysis regarding the impact of the status of blood pressure control on CAS showed that hypertensive patients with controlled blood pressure had a significantly higher incidence of CAS than those with uncontrolled blood pressure (45.2 vs 27.9%, P<0.001), and that uncontrolled blood pressure was negatively associated with ACh-induced CAS (odds ratio: 0.56, 95% confidence interval: 0.40-0.79, P=0.001). In conclusion, despite the expected endothelial dysfunction, hypertension and uncontrolled blood pressure are negatively associated with CAS, suggesting that the mechanisms and risk factors of CAS may be significantly different from those of coronary artery disease.

Implication of lipocalin-2 and visfatin levels in patients with coronary heart disease

OBJECTIVES

Visfatin and lipocalin-2 are novel adipokines associated with insulin resistance (IR) and obesity-related metabolic disorders. We compared lipocalin-2 and visfatin concentrations between patients with coronary heart disease (CHD) and control subjects and evaluated their association with cardiovascular risk factors.

METHODS

We examined serum visfatin, lipocalin-2 levels, and cardiovascular risk factors in 91 subjects (49 patients with angiographically confirmed CHD versus 42 age- and gender-matched control participants).

RESULTS

Circulating lipocalin-2 levels were significantly higher in patients with CHD compared with the control subjects (82.6+/-38.7 ng/ml versus 43.8+/-27.8 ng/ml; P<0.001). However, visfatin levels were not significantly different between patients with CHD and control subjects. Serum lipocalin-2 levels were positively associated with weight (r=0.26; P=0.036), fasting insulin (r=0.36; P=0.003), and IR (r=0.33; P=0.007), whereas these levels showed a negative correlation with high-density lipoprotein (HDL) cholesterol (r=-0.30; P=0.016) after adjustment for gender and body mass index. However, visfatin levels were not associated with any variables of the metabolic syndrome. The multiple regression analysis showed that lipocalin-2 levels were independently associated with HDL cholesterol and IR (R2=0.199). Furthermore, the multiple logistic regression analysis showed that systolic blood pressure, IR, and lipocalin-2 levels were independently associated with CHD.

CONCLUSIONS

Serum lipocalin-2 levels were significantly elevated in patients with CHD and were independently associated with CHD. The present findings suggest that the measurement of serum lipocalin-2 levels may be useful for assessing CHD risk.

Myocardial bridging is related to endothelial dysfunction but not to plaque as assessed by intracoronary ultrasound

BACKGROUND

Myocardial bridge (MB) is characterised by focal compression of a coronary artery in systole by an overlying band of myocardium. Chronic compression and relaxation of the MB may produce endothelial dysfunction by direct stress.

OBJECTIVE

To determine whether MB alters endothelial function, thus influencing the plaque formation.

METHODS

128 patients (mean (SD) age 54.7 (10.9) years, 56 men) with typical angiographic systolic milking effects and >30% reduction in diameter of the coronary artery during systole after intracoronary nitrate (glyceryl trinitrate, 200 mug) infusion were studied. 231 control patients (mean (SD) age 52.9 (12.1) years, 111 men) without overt coronary artery disease including MB were also studied. Endothelial function was estimated by incremental acetylcholine (Ach) infusion into the left coronary ostium. Intracoronary ultrasound assessments were obtained in 74/128 patients with MB and 81/231 controls.

RESULTS

The mean (SD) vasoconstrictive response to maximal Ach was more pronounced at the bridging segments than at matched segments in controls (-71.9 (14.9) vs -30.3 (22.6), p = 0.009). Coronary vasoconstriction (>50%) to Ach was seen more often in the MB group than in controls (114/128 (89.1%) vs 81/231 (35.1%), p = 0.007). No significant correlation was found between the severity of MB and vasoconstriction in response to Ach. A typical half-moon phenomenon was seen in 71/74 (95.9%) cases of the MB group, but not in controls (p<0.001). Plaques at the bridging segments were absent in 67/74 (90.5%) and mild in 7/74 (9.5%) cases, as compared with those of matched segments of the left anterior descending coronary artery in controls (plaque burden 5.91 (1.37)% vs 24.71 (24.21)%, p = 0.002).

CONCLUSION

Despite the prominent relationship between MB and endothelial dysfunction, bridging segments are spared from atherosclerotic plaque formation.

Relationship between blood pressure parameters and pulse wave velocity in normotensive and hypertensive subjects: invasive study

Blood pressure (BP) is one of the most important contributing factors to pulse wave velocity (PWV), a classic measure of arterial stiffness. Although there have been many non-invasive studies to show the relation between arterial stiffness and BP, the results are controversial. The aim of this study is to evaluate the role of BP as an influencing factor on PWV using invasive method. We observed 174 normotensive and untreated hypertensive subjects using coronary angiography. Arterial stiffness was assessed through aorto-femoral PWV by foot-to-foot velocity method using fluid-filled system. And BP was measured by pressure wave at the right common femoral artery. From univariate analysis, age, diabetes mellitus (DM), hypertension, waist, waist-to-hip ratio, total cholesterol-to-high-density lipoprotein cholesterol ratio, systolic BP (SBP), pulse pressure (PP) and mean arterial pressure (MAP) showed significant association with PWV. To avoid multiple colinearity among SBP, PP and MAP, we performed multiple regression analysis predicting PWV thrice. Age, DM and each BP were significantly and consistently correlated to PWV. In the first and third modules, compared to age, SBP and MAP were less strong predictors, respectively. However, PP was the stronger predictor than age and DM in the second module. Lastly, we simultaneously forced MAP and PP with other variables in the fourth multivariate analysis. Age, DM and PP remained significantly correlated with PWV, but the significance of MAP was lost. This is the first invasive study to suggest that PP has the strongest correlation with PWV among a variety of BP parameters.

Delayed severe multivessel spasm and aborted sudden death after Taxus stent implantation

Sudden cardiac arrest associated with major spasm of three coronary arteries was observed about 10 hours after Taxus stent insertion in a three vessel lesion and was successfully treated by intracoronary glyceryl trinitrate infusion. This case illustrates a potential risk associated with drug eluting stent and alerts clinicians to the life threatening risk of spasm when stenting multiple vessels with drug eluting stent (especially the Taxus stent).

Inflammation, insulin resistance, and glucose intolerance in acute myocardial infarction patients without a previous diagnosis of diabetes mellitus

We examined the prevalence of impaired glucose metabolism and its association with inflammation and insulin resistance (IR) in acute myocardial infarction (AMI) patients without a previous diagnosis of diabetes. This prospective study enrolled 52 AMI patients, and 75-g oral glucose tolerance testing was performed on 30 patients at discharge and again 3 months later. We also measured serum adiponectin, high sensitive C-reactive protein, and IL-6 on both occasions. Data were compared with those of 30 type 2 diabetic patients without a history of AMI. Forty percent and 36.7% of AMI patients had impaired glucose tolerance (IGT) at discharge and at 3 months, respectively. The corresponding proportions for newly diagnosed diabetes are 33.0% and 30.0%. At discharge, AMI patients with IGT or diabetes showed higher high sensitive C-reactive protein and IL-6 levels compared with AMI patients with normal glucose tolerance or control type 2 diabetic patients. Furthermore, AMI patients with IGT or diabetes exhibited higher IR and lower serum adiponectin levels than AMI patients with normal glucose tolerance at 3 months after discharge. Previously undiagnosed diabetes and IGT are common in Korean patients with AMI. These glycometabolic abnormalities are associated with inflammation, IR, and serum adiponectin levels.

Novel method for cell immobilization and its application for production of oligosaccharides from sucrose

AIMS

The purpose of the present investigation was to develop a novel method for cell immobilization.

METHODS AND RESULTS

Aureobasidium pullulans cells were mixed with an alginate solution, and the mixture was extruded to form small gel beads as hydrated-immobilized cells. The beads were then placed at -15 degrees C for 6-24 h to induce freeze-dehydration. The freeze-dehydration resulted in shrinkage of beads as a result of water removal reducing bead volume by 82% and bead weight by 85%. The dehydrated beads were successfully used for the production of fructo-oligosaccharides in a model reactor system.

CONCLUSIONS

Dehydrated beads may provide some commercial advantages over conventional immobilized cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows that bioreactor performance can be improved up to two times by the use of the dehydrated beads.

An immunohistochemical method for the detection of proteins in the vertebrate lens

Fluorescence immunohistochemistry has traditionally been difficult or impossible to perform on the vertebrate lens because of its extremely high protein content. Described here is a robust and rapid method for preparing and labeling vertebrate eyes for confocal microscopy. This technique has successfully been applied to localize proteins in the lens epithelium and capsule, as well as the primary and secondary fibers. This technique preserves tissue morphology and coupled with double and triple labeling, has allowed localization of proteins bound to plasma membrane, basement membrane, nucleus, endoplasmic reticulum as well as sub-nuclear compartments. In addition, the present technique has proven useful for fluorescent immunohistochemical analysis of diverse tissues including whole embryos, adult muscle, pancreas, and liver. This procedure allowed us to successfully localize a wide variety of antigens on diverse vertebrate tissues including the more challenging vertebrate lens.

The prevalence and awareness of hypertension and the relationship between hypertension and snoring in the Korean population

BACKGROUND

Hypertension is the most important, and yet modifiable, risk factor for cardiovascular diseases. But in many countries, hypertension remains poorly controlled. Moreover, sleep apnea syndrome has shown that it is correlated with hypertension. The purpose of this study was to investigate the prevalence, awareness and control of hypertension among the Korean people and to evaluate the relationship between hypertension and snoring.

METHODS

A total of 640 subjects living in Ansan, a regional city in Korea, were selected randomly, and trained nursing students investigated their age, sex, medical history, blood pressure, body mass index (BMI) and snoring score. Blood pressures were measured three times with a 10-minute interval and then averaged. The degree of snoring was estimated using a questionnaire. We divided the subjects into hypertensive (BP > or = 140/90 mmHg) versus normotensive group and snorer versus non-snorer group, and correlated hypertension with snoring.

RESULTS

Of 640 subjects, 311 were male. The mean age was 39.7 +/- 14.6 years (18-77 years), the mean BMI (body mass index) was 22.4 +/- 3.0 kg/m2. The mean systolic and diastolic blood pressure was 121 +/- 15.7 mmHg and 79.5 +/- 11.6 mmHg. The prevalence and awareness of hypertension were 22.2% and 16.9%, respectively, and the prevalence of snoring was 35.2%. With the increment of age, in the male, the prevalence of hypertension and snoring were higher, and the snorer group showed a higher risk of hypertension than the non-snorer group (Odds ratio 2.32, CI = 1.56-3.39, p = 0.0001).

CONCLUSION

In Korea, the prevalence of hypertension was similar to that in the western countries, but the awareness of hypertension was much lower compared with western countries. The prevalence of hypertension was higher in the snorer group, so more research on the correlation between the two conditions should be advanced in the future.

Sequential recovery of sensitivity to negative and positive contrasts during optic nerve regeneration in goldfish

A psychophysical procedure, classical conditioning of respiration, was used to measure contrast sensitivity to positive- and negative-contrast discs (8-deg diameter) in goldfish after crushing one optic nerve intraorbitally. In five out of six fish, sensitivity recovered to normal. Recovery times for negative contrasts were significantly shorter than for positive contrasts. The average times postcrush of initial responding to negative and positive contrasts were 23.8 and 30.6 days, and for threshold to come within 0.5 log unit of control values was 29.8 and 39.8 days, respectively. Thereafter, recovery to normal sensitivity was significantly faster for positive contrasts. These results parallel prior observations of neural activity in tectum after optic nerve crush: an early phase of OFF responding followed by a more sudden recovery of ON responding.

Coronary flow reserve is reflective of myocardial perfusion status in acute anterior myocardial infarction

Our objective was to determine whether coronary vasodilatory reserve (CVR) correlates with the perfusion state of infarct zone in early recovery phase of acute anterior myocardial infarction (AMI). We studied 14 patients (11 males; mean age, 46 years) who had AMI and 6 control subjects who had chest pain but normal coronary angiograms. All patients underwent successful percutaneous revascularization of left anterior descending (LAD) coronary artery. Coronary flow velocity was measured using intracoronary (IC) Doppler at baseline and following IC injection of 18 microg of adenosine. Myocardial perfusion was evaluated by myocardial contrast echocardiography (MCE). CVR was higher in patients without a perfusion defect on MCE than in those with (2.48 +/- 0.21 vs. 1.66 +/- 0.13, P = 0.001). Subjects with a perfusion defect had a lower CVR than controls (1.66 +/- 0.13 vs.2.40 +/- 0.18, P < 0.05). CVR was > 2.0 in all subjects without a perfusion defect. There was a strong correlation between the magnitude of myocardial opacification in the LAD territory and CVR (r = 0.80, P < 0.01). Increase in peak diastolic flow velocity after adenosine infusion, but not systolic flow velocity, correlated with myocardial opacification index (r = 0.63, P = 0.016). CVR of infarct-related artery correlated closely with the perfusion status of the myocardium in infarct zone and those with a CVR > 2.0 had normal myocardial perfusion. These data suggest that CVR may be used to determine the perfusion state of the myocardium in the infarct zone, which is a known predictor of myocardial viability. Cathet. Cardiovasc. Intervent. 51:281-286, 2000.

Intercellular adhesion can be visualized using fluorescently labeled fibrosarcoma HT1080 cells cocultured with hematopoietic cell lines or CD34(+) enriched human mobilized peripheral blood cells

BACKGROUND

Intercellular contacts between adjacent cells migrating over each other are important in many cellular processes. However, it has been difficult to visualize and identify dynamic intercellular adhesions between migrating cells in situ.

METHODS

Two fluorescent membrane dyes, PKH2 and PKH26 for staining HT1080 and hematopoietic cells and cell lines, and an automated fluorescence microscopy system were used to monitor intercellular adhesion.

RESULTS

Cellular extensions connecting two or more adjacent cells were visualized, showing the intercellular adhesion between migrating cells for minutes and up to hours. After cells adhered to each other, followed by cell migration in different directions, cellular extensions were dragged from the pivotal contact points in different focal planes. CD34(+)-enriched mobilized peripheral blood cells and six hematopoietic cell lines showed intercellular connections in cocultures with HT1080. However, the frequency of intercellular connections was variable in different cocultures. A cell density of about 3.1 x 10(4) cells/cm(2) for both cell lines in cocultures provided an adequate number of cells in each field of view, showing up to four intercellular connections per 100 total cells plated.

DISCUSSION

The tools derived from this study will open new areas of investigation for understanding the mechanism of the intercellular adhesion process.

Extension of osmolality-induced podia is observed from fluorescently labeled hematopoietic cell lines in hyperosmotic medium

BACKGROUND

Since the description of long podia extended by hematopoietic cells and cell lines, the reliable elicitation of podia extensions is needed to study these podia systemically. In this study, hyperosmotic stress was considered as an elicitor.

METHODS

Using two fluorescent membrane dyes PKH2 and PKH26, and an automated fluorescence microscopy system, morphological changes of seven human cell lines (six hematopoietic, one fibrosarcoma) at different osmolalities were monitored. Presence of surface molecules on the hyperosmolality-induced podia (osmopodia) was examined.

RESULTS

In hyperosmotic medium, cells shrank rapidly, followed by osmopodia extension. Cells exhibited variable number (up to five) and length (up to longer than 100 microm) of osmopodia in about 1 h. Dead cells did not extend podia. Frequency, length, and number of podia were variable among cell lines studied. CD44 and CD45 were not present on the osmopodia, although they were present on the cell surface, showing that osmopodia characteristics differ from the podia observed previously in isotonic media. The osmopodia extension process was shown to be reversible upon repeated osmolality changes.

CONCLUSIONS

Osmopodia extended by human hematopoietic cell lines display a newly observed cellular morphology and provide a tool for investigation of dynamic cellular response to environmental changes.

Assessment of coronary flow reserve with transthoracic Doppler echocardiography: comparison among adenosine, standard-dose dipyridamole, and high-dose dipyridamole

Coronary flow reserve (CFR), defined as a ratio of hyperemic-to-basal coronary flow velocity, provides important information about the functional aspect of coronary circulation. However, it usually is determined by invasive methods during catheterization. Recent studies have shown that transthoracic Doppler echocardiography (TTDE) may be useful in the measurement of coronary flow velocity in the distal portion of the left anterior descending coronary artery (LAD). The vasodilators used for hyperemia are adenosine and dipyridamole. However, the coronary vasodilative response and systemic hemodynamic effects of the two agents have not been directly compared with TTDE. We assessed blood flow velocity and vascular resistance in the distal LAD by TTDE during an intravenous 2-minute adenosine infusion (140 microg/kg/min) and low- (0.56 mg/kg) and high-dose dipyridamole (0. 84 mg/kg) infusion in 25 patients with patent LAD. Coronary flow velocity was successfully recorded in 20 patients (80%) during baseline and the consecutive vasodilator-infusion period. Compared with low-dose dipyridamole, adenosine infusion induced a higher CFR (3.7 +/- 0.87 vs 2.73 +/- 0.65; P <.05) and a lower coronary resistance index (0.31 +/- 0.04 vs 0.35 +/- 0.08; P <.05). But by increasing the dipyridamole dose to 0.84 mg/kg, the values of the CFR and coronary resistance index became comparable to those of adenosine infusion (2.85 +/- 0.78 vs 3.03 +/- 0.7, P = not significant [NS]; 0.33 +/- 0.04 vs 0.32 +/- 0.09, P = NS; respectively). We conclude that adenosine seems to be a favorable vasodilator for the measurement of CFR with TTDE.

Assessment of coronary flow reserve with transthoracic Doppler echocardiography: comparison with intracoronary Doppler method

To evaluate the feasibility and usefulness of transthoracic Doppler echocardiography (TTDE) as a non-invasive method in recording distal anterior descending (LAD) coronary flow velocity, we compared coronary flow reserve (CFR) measured by TTDE with measurements by intracoronary Doppler wire (ICDW). Twenty-one patients without LAD stenosis were studied. ICDW performed at baseline and after intracoronary injection of 18 microg adenosine. TTDE was performed at baseline and after intravenous adenosine (140 microg/kgmin for 2 min). Adequate Doppler recordings of coronary flow velocities during systole were obtained in 14 of 21 study patients (67%) and during diastole in 17 (81%) patients. Baseline and hyperemic peak diastolic flow velocities measured by TTDE were significantly smaller than those obtained by ICDW (p<0.05). However, diminishing trends of diastolic and systolic velocity ratio after hyperemia were similarly observed in both methods. CFR obtained by TTDE (3.0+/-0.5), was higher than the value calculated by ICDW (2.5+/-0.4). There were significant correlations between the values obtained by the two methods (r=0.72, p<0.01). It is concluded that TTDE is a feasible method in measuring coronary flow velocity and appears to be a promising non-invasive method in evaluating CFR.

Key adhesion molecules are present on long podia extended by hematopoietic cells

BACKGROUND

We recently reported that CD34(+) hematopoietic cells and the KG1a cell line extend long, thin podia. These podia can dynamically extend and retract, often adhere to the substrate, and appear to connect cells up to 300 microm apart. The surface receptors found on these podia have not been described.

METHODS

By using time-lapse fluorescent microscoscopy and immunostaining techniques, we describe a method for detecting surface receptors on these podia. This includes an in situ antibody staining procedure without fixing cells.

RESULTS

We demonstrate, using CD34 selected mobilized peripheral blood cells and KG1a cells, that adhesion molecules known to play important roles in blood-cell migration and adhesion are present on these podia. These include: CD11a, CD18, CD29, CD34, CD45, CD49d, CD49e, and CD62L. Additionally, CD54 and CD44 were present on the podia extended by KG1a cells, but were not detectable on the primary CD34(+) cells. The integrin CD49d localized at the base of these podia in a time-dependent manner in KG1a cells. The frequency and morphology of these long podia on three myeloid leukemia-cell lines (KG1a, MV4-11, and AML-193) and a CD34-negative T-cell line (CEM) are also compared. KG1a and CEM cell lines extend long, dynamic podia that are similar to the podia on primary CD34(+) cells in morphology and adhesion molecule expression. The AML-193 and MV4-11 cell lines, however, did not extend these long podia.

CONCLUSIONS

We describe a technique that provides a method of detecting surface receptors on thin cell membrane projections. These results support the likely role of these podia in cell migration and cell-cell communication.

Phototoxicity of the fluorescent membrane dyes PKH2 and PKH26 on the human hematopoietic KG1a progenitor cell line

BACKGROUND

The phototoxic effects of the well-known fluorescent membrane dyes PKH2 and PKH26 have been unknown, although their use in cell tracking experiments has increased dramatically. To eliminate the phototoxicity-induced alteration in cell function and morphology, it is essential to examine the suspicious phototoxicity of these dyes.

METHODS

Chemical and phototoxic effects of PKH dyes on the human hematopoietic KG1a cell line were examined. To minimize phototoxicity in long-term cell tracking experiments lasting up to 18 h with a fluorescence microscope system, time-lapse monitoring with different time intervals and exposure times was introduced.

RESULTS

There were no significant effects of the two PKH dyes on cell viability and growth when using dye concentrations up to 5 microM. However, when stained cells were exposed to excitation light, cell viability decreased dramatically, showing the phototoxicity of the PKH dyes. More than 60% of cells stained with 5 microM PKH26 died after 5 min of continuous light exposure. The phototoxic effect was more extensive in cells stained with higher concentrations of the dyes.

CONCLUSIONS

We present guidelines for the optimal use of these dyes by using a defined hardware configuration.

Phototoxicity of the fluorescent membrane dyes PKH2 and PKH26 on the human hematopoietic KG1a progenitor cell line

BACKGROUND

The phototoxic effects of the well-known fluorescent membrane dyes PKH2 and PKH26 have been unknown, although their use in cell tracking experiments has increased dramatically. To eliminate the phototoxicity-induced alteration in cell function and morphology, it is essential to examine the suspicious phototoxicity of these dyes.

METHODS

Chemical and phototoxic effects of PKH dyes on the human hematopoietic KG1a cell line were examined. To minimize phototoxicity in long-term cell tracking experiments lasting up to 18 h with a fluorescence microscope system, time-lapse monitoring with different time intervals and exposure times was introduced.

RESULTS

There were no significant effects of the two PKH dyes on cell viability and growth when using dye concentrations up to 5 microM. However, when stained cells were exposed to excitation light, cell viability decreased dramatically, showing the phototoxicity of the PKH dyes. More than 60% of cells stained with 5 microM PKH26 died after 5 min of continuous light exposure. The phototoxic effect was more extensive in cells stained with higher concentrations of the dyes.

CONCLUSIONS

We present guidelines for the optimal use of these dyes by using a defined hardware configuration.

The effect of continuous ambulatory peritoneal dialysis on change in serum leptin

OBJECTIVE

Elevated serum leptin can contribute to anorexia and poor nutrition in patients with chronic renal failure, because leptin is elevated in chronic renal failure patients with or without dialysis, especially in chronic ambulatory peritoneal dialysis (CAPD) patients. The aim of this study was to find whether leptin can be removed by peritoneal dialysis (PD) and to analyze factors that can affect serum leptin after start of CAPD by observing the change in serum leptin shortly after start of CAPD and its correlation with body mass index (BMI), with serum insulin, and with residual renal function.

DESIGN

Twenty patients who started CAPD during the observation period were studied. Serum leptin was measured by radioimmunoassay before start of CAPD, 3-5 days after start of CAPD, and 1 month and 3 months after start of CAPD. Simultaneously, body weight, serum insulin, and residual renal function were measured. To compensate for the circardian rhythm of leptin, removal of leptin was assessed by measuring dialysate leptin divided by average serum leptin before and after a peritoneal equilibration test (PET).

RESULTS

Leptin was eliminated by PD with a dialysate-to-serum ratio of 0.16+/-0.07, which was comparable to removal of beta2-microglobulin (0.14+/-0.06). The mean serum leptin concentrations did not decrease after 3-5 days of CAPD (8.4+/-13.1 ng/mL-->11.9+/-18.0 ng/mL) despite its removal by PD, and levels increased markedly to 189% of basal serum leptin 1 month after start of PD and to 260% of basal serum leptin 3 months after start of PD. Correlation coefficients (Spearman's rho) between change of serum leptin and change of BMI, of serum insulin, of glomerular filtration rate (average of urine creatinine clearance and urine urea clearance) were 0.267 (p > 0.05, n = 20), 0.441 (p > 0.05, n = 16), 0.706 (p > 0.05, n = 8) respectively.

CONCLUSION

Leptin is removed by peritoneal dialysis. Serum leptin did not decrease in 5 days after the start of PD despite its removal by PD, but increased markedly thereafter, within 3 months after start of PD. We could not find a significant correlation between the change in leptin and the change in BMI. Factors other than fat-mass gain can stimulate leptin increase shortly after start of PD.

The effect of dialysate dwell on gastric emptying time in patients on continuous ambulatory peritoneal dialysis

METHODS AND PATIENTS

We evaluated gastric emptying time (GET) with a technetium (Tc) 99m-sulfur colloid gastric emptying scan in 11 patients on continuous ambulatory peritoneal dialysis (CAPD) (6 males, 5 females) and in 14 controls. We investigated the effect of dialysate dwell on GET by studying the subjects twice: once without dialysate in the abdomen (drained) and once with 2 L of dialysate in the abdomen (full). We also investigated the relationship between body surface area (BSA) and delayed gastric emptying.

RESULTS

(1) The mean gastric emptying rate in 120 minutes in patients on CAPD when drained (67.8%+/-13.4%) was not different from that in controls (65.4%+/-8.6%). (2) The mean gastric emptying rate in 120 minutes in patients on CAPD when full was significantly slower than that when drained (55.6%+/-14.6% versus 67.8%+/-13.4%, p < 0.05). In four of the 11 patients (36.4%), gastric emptying was extremely delayed from normal to abnormal range when full. (3) The BSA of patients who had extremely delayed GET from normal to abnormal range was smaller than that of patients who had minimal delayed or unchanged GET when full (1.5+/-0.11 m2 versus 1.74+/-0.22 m2).

CONCLUSION

This study showed that patients on CAPD had normal gastric emptying when drained, and that gastric emptying was delayed by dialysate dwell, especially in patients who has less than 1.5 m2 of body surface area. Therefore, we suggest that, based on adequacy, intermittent nocturnal peritoneal dialysis or a small volume of dialysate be considered for patients with small body surface area.

Functional properties of retinal ganglion cells during optic nerve regeneration in the goldfish

After being severed, optic axons in goldfish regenerate and eventually restore the retinotectal map; refinement of the map depends upon impulse activity generated by the ganglion cells. Because little is known about the changes in activity and receptive-field properties of ganglion cells during regeneration, we made extracellular recordings from them in the intact eye up to 95 days after sectioning their axons in the optic tract. Their receptive fields were classified as OFF-, ON-OFF-, or ON-centers, and their axonal conduction velocities measured by antidromic activation. The rate of encountering single units dropped drastically at 4-8 days postsection when only a few OFF-center units could be recorded, recovering to normal between 42 and 63 days. Receptive-field centers were normal in size, except for the few OFF-centers at 4-8 days which were abnormally large. Maintained discharge rates of all types were depressed up to 42 days, but ON-OFF-center units were more spontaneously active than normal around 42 days. Light-evoked responses in OFF-center units were subnormal at 4-8 days, becoming supernormal at 16 days and normal thereafter. ON-OFF- and ON-center units started to regain responsiveness at 16 days, and became supernormal at 42 days, before returning to normal. Conduction velocities of all fiber groups dropped to a minimum at 8 days, the fastest being affected most. There was a gradual recovery to normal conduction velocity by 63 days. The conduction latencies of OFF- and ON-OFF-center units recovered to normal by 42 days, and ON-center units by 63 days. Recovery of ganglion cell responsiveness correlates with functional recovery in the retinotectal system: OFF-center units recover light-evoked responses at about the time OFF activity first reappears in the tectum. ON- and ON-OFF-center units recover later, exhibiting supernormal spiking activity around the time that ON responses reappear in the tectum.

Microvascular integrity as a predictor of left ventricular remodeling after acute anterior wall myocardial infarction

The purpose of this study was to investigate the relation of microvascular integrity and ventricular remodeling after acute myocardial infarction. Twenty-six patients with first acute anterior myocardial infarction were studied before discharge with myocardial contrast echocardiography (MCE). Opacification index (OI) and wall motion index were calculated in the left anterior descending artery territory and left ventricular diastolic volume was measured at baseline and during a 9-month follow-up. In total 26 patients, the regional wall motion improved but the left ventricular volume and global function was not changed significantly at follow-up. When the patients were divided into 3 groups according to opacification index (> or = 0.75, 0.5 approximately 0.75, < or = 0.5) at baseline, functional recovery was not observed and significant left ventricular dilatation was developed in patients with < or = 0.5 OI. Among the baseline echo-parameters such as ejection fraction, wall motion score, left ventricular volume and opacification index, the best predictor for long term left ventricular dilatation was the opacification index by multivariate analysis. In patients with acute anterior wall infarction the assessment of microvascular integrity by MCE at acute stage provides useful information regarding recovery of dysfunctional regional wall motion and ventricular remodeling.

Clinical and electrophysiological characteristics in Korean patients with WPW syndrome

This study was designed to investigate the clinical and electrophysiologic characteristics of WPW syndromes in Korea. A total of 400 symptomatic WPW syndrome patients were consecutively recruited. The most common documented symptomatic tachyarrhythmia was orthodromic atrioventricar reentrant tachycardia (75.3%), followed by atrial fibrillation (31.3%), and antidromic atrioventricular reentrant tachycardia (6.2%). There was a higher incidence of multiple bypass tract in patients with antidromic tachycardia than in those with orthodromic tachycardia (30.4 vs 4.3%, P < 0.001). The inducibility of tachyarrhythmia with electrophysiologic study in this study population was 95.8%. The most frequent location of the accessory pathway was the left free wall (48.0%), followed by the right free wall (29.1%), posterior septum (17.5%) and anterior septum (3.5%). These results indicated that 1) clinical and electrophysiological characteristics of Korean patients with WPW syndrome were similar to those of western countries and 2) the electrophysiologic study was important in the evaluation of patients with WPW syndrome.

Axonal conduction velocities of functionally characterized retinal ganglion cells in goldfish

1. Visual response properties and conduction velocities of retinal ganglion cells were studied by extracellular recordings in the intact goldfish eye. Visually responsive single units were confirmed as ganglion cells by collision testing, and their receptive fields were mapped. 2. From compound action potentials, we identified groups I-V in the optic nerve, with overall conduction velocities of 11.5 +/- 1.17, 7.1 +/- 0.79, 4.4 +/- 0.56, 3.1 +/- 0.31 and 2.3 +/- 0.18 m s-1 (mean +/- S.D.) at 23 degrees C. 3. Ganglion cells were classified by their receptive fields as off-, on-off- or on-centre. Nearly all confirmed ganglion cells had axonal conduction velocities in groups II, III and IV; none fell in the fastest group, I. 4. Off-centre ganglion cells had conduction velocities only in the fast group, II. On-off-centre cells fell mainly in group III, with some in group, II. On-centre cells fell in groups II-V, but mainly in groups III and IV. 5. Receptive field centre diameters were 5-30 deg measured with a photopic background. The mean diameters for off-, on-off- and on-centres were 24, 15 and 18 deg, respectively. The relatively larger diameter and higher rate of spontaneous firing of the off-centre cells were maintained under different adaptation conditions. 6. The off-centre cells can be identified with an anatomical class of large, alpha-like ganglion cells in the goldfish retina.

Coronary stenting (Cordis) without anticoagulation

We evaluated the effect of antithrombotic regimens on subacute thrombosis and short-term clinical courses after successful implantation of the Cordis coronary stent, which is a flexible, balloon expandable, radiopaque tantalum stent. Two hundred seventy-five consecutive patients with 290 lesions were treated with 356 Cordis stent implantations. According to poststent antithrombotic regimen, patients were divided into 3 groups; 165 patients with 175 lesions received aspirin 200 mg/day, ticlopidine 500 mg/day, and warfarin for 1 month (group 1), 66 patients with 69 lesions received aspirin and ticlopidine (group 2), and 44 patients with 46 lesions received aspirin alone (group 3) after successful Cordis stenting. The overall procedural success rates were 97.7% in group 1, 98.6% in group 2, and 100% in group 3. More than 65% of the patients were eligible for elective stenting. The overall rate of stent thrombosis was 1.8%: 1.2% in patients assigned to the treatment with aspirin, ticlopidine, and warfarin; 0% in patients with aspirin and ticlopidine; and 6.8% in patients assigned to the treatment with aspirin alone. In conclusion, the Cordis coronary stent is an effective endovascular stent in various clinical indications including unstable angina and acute myocardial infarction. Antiplatelet therapy using aspirin and ticlopidine after successful Cordis coronary stenting is a promising alternative to anticoagulation therapy to overcome the drawbacks of stenting. However, poststent antithrombotic therapy with aspirin alone is associated with a significant rate of stent thrombosis.

Effect of a gamma-aminobutyric acid uptake inhibitor, NNC-711, on spontaneous postsynaptic currents in cultured rat hippocampal neurons: implications for antiepileptic drug development

The effect of a novel gamma-aminobutyric acid (GABA) uptake inhibitor, NNC-711, on spontaneous postsynaptic currents was studied in cultured rat hippocampal neurons by the whole cell patch clamp method. NNC-711 decreased the amplitude of inhibitory postsynaptic currents (IPSCs) and did not prolong the decay. NNC-711 also decreased the amplitude of excitatory PSCs (EPSCs). The GABAB receptor antagonist 2-OH saclofen abolished the effect on both IPSCs and EPSCs. NNC-711 itself induced no current and had no effect on currents induced by exogenously applied GABA. These findings suggest that duration of GABAA-receptor mediated IPSCs is not determined by GABA uptake and that GABA uptake inhibitors may work by allowing GABA to remain in the synaptic area long enough to activate presynaptic GABAB receptors.

Intracoronary papaverine but not adenosine reduces regional ventricular function

OBJECTIVES

Whether intracoronary papaverine or adenosine leads to reductions in regional left ventricular function was tested.

METHODS

Fifteen anaesthetised dogs were prepared to record aortic pressure, left ventricular pressure dP/dt, electrocardiogram, regional ventricular shortening, and phasic and mean left circumflex coronary blood flow, and to give intracoronary boluses of papaverine (2, 4, or 6 mg) or adenosine (0.37 and 1.87 mg).

RESULTS

Injected doses were chosen to mimic those given in the clinical setting. Papaverine (6 mg) reduced aortic pressure (mean 96(SD 17) to 89(18) mm Hg; p < 0.05), segmental shortening of the infused left circumflex zone (12(5) to 7(9)%; p < 0.05), and area of the pressure-length loop of the infused zone (120(71) to 53(47) mm.mm Hg; p < 0.05). Papaverine increased coronary blood flow (48(25) to 259(95) ml.min-1; p < 0.05), coronary vascular conductance (0.40(0.20) to 2.93(0.94) ml.mm Hg-1.min-1; p < 0.05), heart rate (88(27) to 100(28) beats.min-1; p < 0.05), and the segmental shortening (17(6) to 19(3)% p < 0.05) and area of the pressure-length loop (130(32) to 177(33) mm.mm Hg; p < 0.05) of the non-infused left anterior descending region. The hyperaemia elicited by papaverine was greater than that of reactive hyperaemia (p = 0.008). Papaverine also increased the QT interval corrected for heart rate (0.35(0.04) to 0.45(0.05) s; p < 0.05). When adenosine was given, coronary blood flow and coronary vascular conductance were increased to similar degrees as those during reactive hyperaemia (41(12) to 210(75) ml.min-1 and 0.46(0.14) to 2.43(0.83) mm Hg.ml-1.min-1, respectively; NS). No effects on segmental shortening or the area of the pressure-length loop in either zone were found. Also, adenosine had no effect on the QT interval.

CONCLUSIONS

These adverse effects of intracoronary papaverine have important implications in its use in patients, particularly in those in whom abnormal cardiac function already exists. Adenosine, on the other hand, seems to be without deleterious effects.

Production of monoclonal antibodies against human chorionic gonadotropin by hybridoma cultures in calcium alginate capsules

A new method of making microcapsules with calcium alginate gel was developed and the cultivation of the encapsulated hybridoma cells producing monoclonal antibodies against human chorionic gonadotropin was investigated. A high cell density of 2.0 x 10(8) cells/cm3 in the capsules led to a high dilution rate of 0.67 per hour and resulted in the high volumetric monoclonal antibody productivity of 652.8 mg/l/day, which was 20-30 times higher than those of traditional continuous suspension cultures. However, long-term continuous culture was not achieved with this capsule system probably because of the limitation in nutrient supply and the accumulation of waste products. Also the analysis of oxygen transfer in this system showed that oxygen supply was not enough to support such a high cell density.

Comparison of single-photon emission computed tomographic (SPECT) myocardial perfusion imaging with thallium-201 and technetium-99m sestamibi in dogs

OBJECTIVES

The purpose of the present study was to compare single-photon emission computed tomographic (SPECT) myocardial images of technetium-99m (Tc-99m) sestamibi and thallium-201 (Tl-201) isotopes in the same dog undergoing partial coronary occlusion during pharmacologic vasodilation.

BACKGROUND

To date, no controlled study has been reported comparing SPECT Tc-99m sestamibi with SPECT Tl-201 imaging during stress with anatomic and physiologic standards.

METHODS

Mongrel dogs were anesthetized with chloralose and instrumented to record left anterior descending coronary blood flow and aortic pressure. Partial coronary occlusion with a hydraulic cuff reduced coronary vascular conductance, which is equal to the coronary blood flow normalized to aortic pressure during peak vasodilation with intravenous adenosine. Each dog received 5 mCi of Tl-201, then 30 mCi of Tc-99m sestamibi during partial coronary occlusion at peak vasodilation. Tomographic myocardial imaging was performed in a 180 degrees anterior arc scan for 33.5 min, first with Tl-201, and later, without moving the dog, for 33.5 min with Tc-99m sestamibi. Postmortem staining defined the region underperfused because of its dependence on the artery that was partially occluded.

RESULTS

In seven dogs with moderate reduction in coronary blood flow, coronary vascular conductance decreased with partial coronary occlusion (47 +/- 12%) during Tl-201 imaging and (47 +/- 8%, p = NS) during Tc-99m sestamibi imaging. The underperfused region was 23.9 +/- 6.4% of total left ventricular mass. Counts in the defects were 39% higher (0.86 +/- 0.08 of normal counts) for Tc-99m sestamibi than for Tl-201 (0.64 +/- 0.09 of normal counts, p < 0.001), and the defect on SPECT Tc-99m sestamibi images occupied only a fraction (0.37 +/- 0.30) of the area of the defect on the Tl-201 images of the same dog. Bull's-eye displays constructed from the pathologic slices showed that the Tl-201 defect size was closer to the underperfused region of the left ventricular mass determined pathologically than was the Tc-99m sestamibi defect size. In four additional dogs a severe, near total coronary occlusion was created during Tl-201 and Tc-99m sestamibi administration. In these dogs, similar defect contrast (0.55 +/- 0.12 vs. 0.62 +/- 0.09, p = NS) and areas (0.18 +/- 0.07 vs. 0.18 +/- 0.11, p = NS) were observed with Tl-201 and Tc-99m sestamibi, respectively.

CONCLUSIONS

Tomographic myocardial imaging with Tc-99m sestamibi during moderately severe partial coronary occlusion underestimated the area of the defect relative to Tl-201 or to the pathologic reference standard in dogs. Defect contrast was sharper with tomographic myocardial Tl-201 than with tomographic myocardial Tc-99m sestamibi during moderately severe partial coronary occlusion.

Desensitization of GABA-induced currents in cultured rat hippocampal neurons

The basic characteristics of desensitization of the GABAA receptor were investigated in cultured rat hippocampal neurons (three days to four weeks in vitro) using whole cell patch clamp techniques. GABA at 10-500 microM was perfused on to neurons for 30 or 60 s, with 60 s intervals of wash with control bath solution between perfusions. Desensitization, evaluated by peak-to-plateau ratio and time constants of current decay (tau), was dose-dependent and culture age-dependent. Desensitization was observed as early as three days in culture, the earliest time tested. At all ages, higher concentrations of GABA induced both larger and faster desensitization. Desensitization was markedly voltage-dependent and decreased with depolarization; peak-to-plateau ratio went from 6.3 to 1.4 and tau went from 4.6 to 26.8 s when holding potentials were changed from -80 mV to +30 mV. Low concentrations of GABA (1-2 microM) perfused for 2-60 s, which did not induce any current, had no effect on the maximal response nor desensitization produced by a subsequent application of 100 microM GABA. This finding suggests that GABA receptors were not desensitized without first being activated.

Diverticular disease of the colon in Korea

This study is designed to determine the relative prevalence and characteristics of diverticular disease of the colon in Korea. We did a retrospective evaluation of 16,964 consecutive barium enemas performed at Koryo General Hospital between January 1971 and October 1986, and found 100 patients with diverticular disease of the colon. The results are as follows: 1) Colonic diverticula were found in 100 patients, and incidence of 0.59% in 16,964 consecutive barium enemas. The male to female ratio was 2.1:1. 2) Incidence rose with advancing age from 0.45% in the second decade to 2.5% in the seventh decade. 3) Patient age ranged from 19 to 77 years with more than 70% of the patients in the 5th, 6th and 7th decades. 4) The greater majority (81%) of the diverticular disease the right colon. 5) Fifty percent of the cases were classified as multiple diverticula. 6) The mean age of patients with right sided diverticula was 47.5 years and that of patients with left sided diverticula was 57.7 years. The mean age of single diverticular patients was 50.4 years and that of multiple diverticular patients was 48.4 year. 7) Associated diseases were hemorrhoids (18%), gall stones (12%) and previous appendectomy (11%). Among the 29 patients who had hemorrhoids and or a previous appendectomy, 28 of those had right sided diverticula.

Plasma apolipoproteins and lipids in normal persons and patients with hypertension

We measured apolipoprotein A (ApoA), apolipoprotein B (ApoB), and lipid levels in 115 hypertensive patients and 100 normal subjects in order to evaluate the risk of atherosclerotic heart disease in hypertensive patients. The hypertensive patients were divided into the following subgroups: blood pressure controlled (A) and uncontrolled hypertensive subgroup (B), and without complication (C) and with complication (D).

In the hypertensive group, the mean plasma ApoA, ApoB, total cholesterol, triglyceride and beta-lipoprotein (LpB) levels were significantly higher than in the normal control group. The plasma high density lipoprotein cholesterol (HDL-cholesterol) level was not significantly different between the hypertensive group and the normal control group. ApoB/A ratio in the hypertensive group was higher than in the normal control group, but the difference was not significant statistically.

In the hypertensive subgroups, plasma Apo A was higher in all the hypertensive subgroups compared to normal control group, but these differences were not statistically significant. In subgroup B, C and D, the plasma ApoB level increased significantly as compared to the normal control group, but not so in the subgroup A. All of the subgroups had significantly higher levels of triglyceride and LpB level than the normal control group. HLD cholesteol level of all of the subgroups did not show any significant difference as compared to the normal control group. In subgroup B, C and D, the ApoB/A ratio was not significantly different from the normal control group. In the subgroup A, ApoB/A ratio was lower than in the normal control group, this was not significant statistically. Between subgroup A and B, and subgroup C and D, all of the plasma lipids and apolipoproteins did not show significant differences.

Thus our results showed that ApoB, LpB and triglyceride, which are closely related to atherosclerotic heart disease, were significantly increased in any of hypertensive subgroups compared to the normal control group.