Blood pressure at health screening as a predictor of coronary heart disease in Kyoto

AIM

Most epidemiologic studies that have evaluated coronary risk factors have measured either mortality or morbidity of coronary artery disease (CAD) as endpoints. However, earlier detection and elimination of coronary risk factors are crucial. We therefore performed Master's double (i.e. 1.5 min x 2 = 3 min) two-step exercise electrocardiograph (ECG) test in apparently healthy asymptomatic subjects (men, n = 2274; women, n = 959) to elucidate the risk factors for early-stage CAD or silent myocardial ischemia.

METHODS

We examined the possible association of blood pressure at health screening and other suspected risk factors with exercise ECG test performance. The ischemic ECG response was determined by (1) > or = 0.5 mm horizontal or sagging S-T segment depression, (2) > or = 2.0 mm J-shaped S-T segment depression, or (3) T inversion in post-exercise ECG.

RESULTS

We found that 4.7% of men and 10.6% of women exhibited ischemic responses. Among males, the ischemic responders to the exercise ECG test had higher systolic and diastolic blood pressure. In addition, the male ischemic responders were older, had a higher obesity index, higher serum cholesterol, triglyceride, low-density lipoprotein (LDL)-cholesterol, protein, glucose, and uric acid levels, and a lower serum potassium level than normal responders. In contrast, the female ischemic responders to the exercise ECG test had higher systolic pressure, and higher serum cholesterol, LDL-cholesterol, and protein levels than normal responders. Mean blood pressure was correlated positively with most of the other coronary risk factors, and mild hypertensives and hypertensives had abnormal lipid, glucose, and uric acid levels in both sexes. A comparison of risk factors by age group revealed that only younger and middle-aged ischemic responders had higher blood pressure, serum cholesterol, and glucose levels than normal responders of both sexes, and that in older subjects all the differences between normal and ischemic responders became insignificant.

CONCLUSIONS

Elevated blood pressure at health screening, together with abnormal lipid and glucose metabolism, might be risk factors predicting early-stage or silent CAD. The elimination of these risk factors in younger men and women seems to be important.

Prognosis of hypertrophic cardiomyopathy: assessment by 123I-BMIPP (beta-methyl-p-(123I)iodophenyl pentadecanoic acid) myocardial single photon emission computed tomography

123I-BMIPP (beta-methyl-iodophenyl pentadecanoic acid) has shown unique properties for potential use in assessing myocardial metabolism. Previous basic and clinical studies demonstrated that the disturbances of myocardial metabolism precede the occurrence of myocardial perfusion abnormalities by using 201Tl in hypertrophic myocardium. The present study was therefore undertaken to determine whether or not 123I-BMIPP myocardial SPECT is useful in predicting the prognosis of hypertrophic cardiomyopathy (HCM) in 65 patients in 6 facilities. There were 33 patients with non-obstructive HCM, 12 with obstructive HCM, 12 with apical HCM and 8 with dilated-phase HCM. Fasted patients at rest received an intravenous injection of 111 MBq of 123I-BMIPP. Twenty to thirty minutes later, myocardial SPECT was carried out. The BMIPP severity score (BMIPP SS) was evaluated semiquantitatively by using representative short axial SPECT images. We followed up the incidence of cardiac events for a mean period of 3.0 +/- 0.6 years. Cardiac events occurred in 13 patients. Of these, 11 developed heart failure and 6 died (4 from heart failure and 2 from sudden death). The BMIPP SS in the dilated-phase HCM was significantly lower than that for the nonsurvivors. The BMIPP SS was particularly high in patients with fatal heart failure. Furthermore, there was a close negative correlation between the BMIPP SS and percent fractional shortening measured by echocardiography (r = -0.49). Finally, the mortality over the three years increased according to the extent of the BMIPP SS. In conclusion, these results indicate that BMIPP SS is useful in evaluating the severity of HCM. We conclude that 123I-BMIPP is a valuable metabolic tracer in predicting the outcome of HCM.

Postischemic functional recovery and BMIPP uptake after primary percutaneous transluminal coronary angioplasty in acute myocardial infarction

To correlate asynergic wall motion after primary percutaneous transluminal coronary angioplasty with myocardial perfusion and fatty acid metabolism, quantitative tomographies using thallium and radioiodinated 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) were performed during the acute and recovery stages in 56 consecutive patients with acute myocardial infarction, of whom 32 underwent primary percutaneous transluminal coronary angioplasty (group A) and 24 were conservatively treated (group B); 44 patients (79%) had 1-vessel disease. Reduced myocardial uptakes of thallium and BMIPP and regional wall motion were quantified with a bull's eye technique and a centerline method using contrast left ventriculography, respectively. BMIPP activity was significantly lower than that of thallium at an acute stage in both groups. Abnormal BMIPP activities and the difference in thallium and BMIPP abnormalities (perfusion metabolism mismatch) at an acute stage decreased significantly during follow-up in group A (111 +/- 13 to 99 +/- 12 and 30 +/- 10 to 15 +/- 10, respectively), and not in group B (129 +/- 31 vs 118 +/- 29 and 29 +/- 13 vs 30 +/- 10, respectively). Improvement in regional wall motion abnormality correlated closely with the improved uptakes of thallium and BMIPP (y = 0.64x + 26.4, r = 0.56, p < 0.05; y = 1.1x + 11.1, r = 0.81, p < 0.001; respectively). The mismatched uptake of both tracers at an acute stage was significantly related to recovery from asynergic wall motion during follow-up in group A (y = 0.45x + 13.9, r = 0.65, p < 0.005). In conclusion, despite restored myocardial perfusion by primary coronary angioplasty, BMIPP uptake is impaired in salvaged myocardium at an acute stage of infarction. However, the degree and improvement of perfusion metabolism mismatch in acute myocardial infarction may reflect subsequent recovery from postischemic wall motion abnormality in metabolically impaired but viable myocardium after coronary reperfusion.

mRNA expression of KIF1A, KIF1B, KIF2, KIF3A, KIF3B, KIF4, KIF5, and cytoplasmic dynein during axonal regeneration

Mouse brain expresses multiple kinesin superfamily proteins (KIFs), which are involved in vesicle transport. The expression of KIFs is developmentally regulated, and both the mRNA and proteins of KIF2 and KIF4 are expressed abundantly in the juvenile brain. To elucidate the role of individual kinesin superfamily motor proteins during regenerative outgrowth of axons, we examined the mRNA expression of KIF1A, KIF1B, KIF2, KIF3A, KIF3B, KIF4, and KIF5 in adult mouse dorsal root ganglion cells after sciatic nerve crush. Seven to fourteen days after the nerve crush, the mRNA expression pattern of neurofilament and beta-tubulin isotypes suggested that the regenerative outgrowth of axons was active. At these stages, levels of mRNA for KIF1A, KIF1B, KIF2, KIF3A, KIF3B, KIF4, and KIF5 were 50.80% of control. The levels of mRNA for KIF4, which are detected in juvenile brain but not in the adult, were under the detection limit in both control and regenerating dorsal root ganglion cells. Because mRNA of neither KIF2 nor KIF4 increased significantly, the results suggest that the gene expression of KIFs during regeneration does not recapitulate the embryonic development and support the hypothesis that different series of events take place during the regenerative and embryonic outgrowths of axons. In contrast, mRNA for cytoplasmic dynein was slightly increased, up to 140%. This is consistent with the hypothesis that retrograde transport plays critical roles in regeneration such as the transport of neurotrophic factors.

Effects of gamma-linolenic and eicosapentaenoic acids on blood pressure in SHR

1. The present study was performed to determine whether chronic treatments with gamma linolenic acid (n-6, GLA) or eicosapentaenoic acid (n-3, EPA) would alter serum and red blood cell (RBC) unsaturated fatty acid composition, and to determine whether these treatments would affect blood pressure (BP), serum lipid metabolism and the development of atherosclerosis in spontaneously hypertensive rats (SHR). 2. To compare the effects on atherosclerosis, some SHR were denuded of aortic endothelium so that the development of atherosclerosis would be accelerated. Olive oil (control), GLA or EPA (low dose: 5 mg/day per rat, high dose: 50 mg/day per kg, respectively) was administered intraperitoneally for 6 weeks in SHR. 3. GLA treatments increased GLA and its metabolite, dihomo-GLA, levels in serum but not in RBC, while EPA treatments increased EPA level both in serum and in RBC. 4. The BP of control SHR was further elevated. EPA significantly reduced this elevation of systolic, mean and diastolic pressure within the first week and thereafter, whereas GLA did not affect BP elevation. Neither heart rate or bodyweight gain was affected by these treatments. 5. Serum total cholesterol (TC), triglyceride (TG), and glucose (G) levels and the development of atherosclerosis were unaffected by either GLA or EPA treatment. 6. In summary, chronic EPA but not GLA treatment slightly reduced BP elevation in SHR. Although chronic GLA or EPA treatment increased the respective serum level, these treatments unaltered serum TC, TG and G levels, and could not prevent the development of aortic atherosclerosis in SHR.

Differences in the characterization of the Ca2+ current in ventricular myocytes between spontaneously hypertensive rats and normotensive rats

1. The slow inward Ca2+ current elicited at the membrane potential -30 mV in SHR and normotensive Wistar rats (WR) with voltage-clamp recording was examined for this study. 2. The maximal Ca2+ current of WR in the current-voltage relationship showed the unified membrane potential of +10 mV and the amplitude was -1.2 +/- 0.2 pA. In the case of SHR, however, the maximal Ca2+ current showed a lower and variable membrane potential between 0 and -20 mV. The amplitudes were -1.7 +/- 0.9 pA at 0 mV, -2.1 +/- 0.8 pA at -10 mV and -4.4 +/- 0.3 pA at -20 mV. 3. From the cell-attached patch-clamp recording, the conductance of unitary Ca2+ current and the slope value were the same in SHR and in WR. From the open-time histogram of the Ca2+ channel, the open state probability in SHR increased and the time constant from the exponential curve became slightly extended in SHR. 4. L-isoproterenol at 10(-6) mol/L increased the Ca2+ current in SHR and WR. The increased ratio of Ca2+ current by l-isoproterenol was smaller in SHR than that in WR. 5. The aspect of 1-4 suggests that the increase in Ca2+ current in SHR obtained by the voltage-clamp was explained partly by the increase of open-state probability of unitary Ca2+ channel activity, and that a possibility of Ca2+ channel being activated by phosphorylation through cAMP did not eventuate.

Role of nitric oxide in impaired coronary circulation and improvement by angiotensin II receptor antagonist in spontaneously hypertensive rats

1. To determine whether coronary flow regulation by nitric oxide (NO) is impaired in the hypertensive heart (HTH), coronary perfusion was measured in isolated rat hearts using NO synthesis inhibitor L-NG-monomethyl arginine (L-NMMA) in Wistar-Kyoto (WKY) rat and spontaneously hypertensive rat (SHR) with and without chronic Nomega-nitro-L-arginine-methylester (L-NAME) treatment. Moreover, the effect of angiotensin II receptor antagonist (AT1 receptor antagonist) (TCV-116) on the impaired coronary circulation in HTH was examined. 2. Coronary flow (CF) was decreased in HTH accompanied with cardiac hypertrophy. The decreased response of CF to L-NMMA infusion was diminished in HTH. It is suggested that NO production was reduced in coronary vasculature in HTH. 3. In chronic L-NAME treated SHR, blood pressure and cardiac hypertrophy were accelerated. Although coronary flow resistance (CFR) was increased, the increased response of CFR to L-NMMA infusion was not altered. 4. The AT1 antagonist improved total minimal coronary flow resistance (MCFR) restoring CFR response in SHR, although it did not recover CFR response in chronic L-NAME treated SHR. 5. Taken together the findings suggest that NO production was exhausted in the coronary artery even in the developing stage of hypertension and this exhaustion could contribute to the impairment of coronary circulation of HTH.

[Induction and release of manganese superoxide dismutase caused by tumor necrosis factor-alpha from mitochondria in human umbilical vein endothelial cells]

The effects of tumor necrosis factor-alpha (TNF-alpha) on cultured human umbilical vein endothelial cells (EC) and five cancer cell lines, A549, ME180, A2780, KURAMOCHI, and Hela, were compared. While A549, A2780, KURAMOCHI, and Hela cells were fairly resistant to the cytolytic effects of TNF-alpha, ME180 cells were sensitive. EC were also less sensitive to TNF-alpha than ME180 cells as judged by the viability of individual cells and by the release of lactate dehydrogenase (LDH) into the medium. Manganese superoxide dismutase (Mn-SOD) was markedly induced by these cytokines in EC and in A549 cells but not in ME180 cells. The levels of Mn-SOD in the conditioned medium of EC were dramatically increased after stimulation with cytokines, whereas those in ME180 and A549 cells were relatively low. The amount of Mn-SOD released appears to be comparable to that from cells lysed by other means. Immunoblot analysis of Mn-SOD in the medium showed that the molecular mass of the immunoreactive protein was the same as mitochondrial Mn-SOD, indicating that no proteolysis had occurred. These data suggest that in vivo the TNF-alpha produced by cancer cells may induce Mn-SOD in vascular endothelial cells, resulting in release of a relatively large amount of this protein into the serum.

Hypothalamic and medullary GABAA and GABAB-ergic systems differently regulate sympathetic and cardiovascular systems

1. To determine whether hypothalamic and medullary GABA (gamma-aminobutyric acid)B stimulation would affect the sympathetic and cardiovascular activities, and to determine whether these effects would be altered in hypertension, baclofen (a GABAB agonist) was injected into a hypothalamic pressor area (ventromedial hypothalamus, VMH), a depressor area (anterior hypothalamus, AH), or a nucleus tractus solitarius (NTS) in normotensive and spontaneously hypertensive rats (SHR). 2. Intracerebroventricular (ICV) injections of a GABAA agonist (muscimol, 1 mu g) decreased blood pressure (BP) and heart rate (HR). ICV injections of baclofen (2 mu g) elicited biphasic depressor and pressor effects, and these effects were abolished by a pretreatment with saclofen (GABAB antagonist, 100 mu g, icv). 3. Muscimol (400 ng) and baclofen (800 ng) injected into VMH decreased sympathetic nerve activity (SNA), BP and HR to almost similar levels, while saclofen injected into VMH increased HR without affecting BP levels. 4. The same dose of baclofen injected into AH increased BP, but muscimol (AH) did not alter BP. 5. Both muscimol and baclofen injected into NTS increased BP, but its magnitude was larger in baclofen injections. 6. Depressor and sympatho-inhibitory effects of baclofen (VMH) in SHR were larger than those in normotensive Wistar-Kyoto (WKY) rats, while pressor responses elicited by baclofen (AH) did not differ between SHR and WKY. 7. In summary, GABA reduces SNA, BP and HR through both GABAA and GABAB receptors in VMH. In addition, the GABAB system acts on AH and NTS to further regulate the cardiovascular activities. In SHR, GABAB-ergic dysfunction in VMH but not in AH might contribute to the development of hypertension.

Role of baroreflex and central alpha2-adrenergic receptor systems in the diurnal variation of blood pressure and heart rate in normotensive and hypertensive rats

1. To elucidate whether baroreflex could contribute to manifest the diurnal blood pressure variations (DBPV) in normotension and hypertension, DBPV were recorded continuously via a femoral artery in awake normotensive (NT) rats and spontaneously hypertensive rats (SHR) with and without sinoaortic denervation (SAD). To determine the role of central alpha2-adrenergic receptor system in DBPV in hypertension, guanabentz (0.5-1.0 mu g/kg per min) was infused in SHR. 2. There were no differences in mean arterial pressure (MAP) variability (SD) of MAP of 24 h (MAP -- SD/MAP) and SD of 24 h heart rate (HR -- SD/HR) between SHR and NT. SAD did not elevate MAP and HR in both SHR and NT. 3. However, in SAD rats, MAP -- SD/MAP was significantly greater than those in sham-operated rats in both SHR and NT, while MAP -- SD/MAP and HR -- SD/HR did not show any difference between the two groups even after SAD. On the other hand, SAD did not augment HR -- SD/HR in either strain. 4. During guanabentz infusion, MAP was significantly lowered in sham-operated and SAD -- SHR. Moreover, MAP -- SD/MAP was significantly reduced in sham-operated, but it was not in SAD -- SHR. 5. These findings suggest that baroreflex could suppress tonically the diurnal change of blood pressure in NT and SHR. The regulation of diurnal blood pressure by baroreflex via a central alpha-adrenergic receptor system may be altered in SHR.

Point mutation of adenosine triphosphate-binding motif generated rigor kinesin that selectively blocks anterograde lysosome membrane transport

In the study of motor proteins, the molecular mechanism of mechanochemical coupling, as well as the cellular role of these proteins, is an important issue. To assess these questions we introduced cDNA of wild-type and site-directed mutant kinesin heavy chains into fibroblasts, and analyzed the behavior of the recombinant proteins and the mechanisms involved in organelle transports. Overexpression of wild-type kinesin significantly promoted elongation of cellular processes. Wild-type kinesin accumulated at the tips of the long processes, whereas the kinesin mutants, which contained either a T93N- or T93I mutation in the ATP-binding motif, tightly bound to microtubules in the center of the cells. These mutant kinesins could bind to microtubules in vitro, but could not dissociate from them even in the presence of ATP, and did not support microtubule motility in vitro, thereby indicating rigor-type mutations. Retrograde transport from the Golgi apparatus to the endoplasmic reticulum, as well as lysosome dispersion, was shown to be a microtubule-dependent, plus-end-directed movement. The latter was selectively blocked in the rigor-mutant cells, although the microtubule minus-end-directed motion of lysosomes was not affected. We found the point mutations that make kinesin motor in strong binding state with microtubules in vitro and showed that this mutant causes a dominant effect that selectively blocks anterograde lysosome membrane transports in vivo.

Splenic metastasis from lung cancer

Splenic metastasis from lung cancer is a rare clinical event, most often diagnosed at the time of autopsy. We report 2 cases of splenic metastasis with a primary lung cancer. The first case was a 76-year-old man presenting with a recurrent solitary splenic metastasis 14 months after surgical removal of a squamous cell carcinoma of the lung. The second patient was a 72-year-old woman who had a poorly differentiated carcinoma of the lung and multiple abdominal metastasis. We also investigated 267 autopsy cases of lung cancer from 1975 to 1992. Histologically, there were 73 cases of squamous cell carcinoma, 123 adenocarcinoma, 29 large cell carcinoma, 36 small cell carcinoma, and 7 other miscellaneous tumours. The number of splenic metastasis from lung cancer in these cases was 15 (5.6%). Splenic metastasis from a primary cancer of the left lung was more frequent than that from the right lung. Nine of 15 splenic metastases were smaller than 1 cm in size. Splenic metastasis was associated with liver and pancreas metastasis. All 15 autopsy cases with splenic metastasis from lung cancer had other abdominal organ metastasis. Our analysis indicates that a solitary splenic metastasis is rare. Selection of a suitable therapeutic approach is important.

Altered cardiovascular responses to purinergic A2 stimulation in the nucleus tractus solitarius of spontaneously hypertensive rats

OBJECTIVE

To investigate the cardiovascular effects of adenosine A2 receptor stimulation in the nucleus tractus solitarius and whether these effects are altered in hypertension.

DESIGN AND METHODS

Ten- or 11-week-old spontaneously hypertensive rats (SHR) or Wistar-Kyoto (WKY) rats were anaesthetized with urethane. Adenosine (100 ng) or adenosine A2 agonist (2-octynyladenosine, 5 ng) were micro-injected (50 nl) into the nucleus tractus solitarius. Blood pressure and heart rate were measured from a femoral artery. Sympathetic nerve activity was recorded from the abdominal splanchnic nerve.

RESULTS

Blood pressure, heart rate and sympathetic nerve activity were consistently decreased after the micro-injection of adenosine into normotensive rats. Changes from the baseline in blood pressure, heart rate and sympathetic nerve activity were significantly smaller in SHR than in WKY rats (blood pressure: SHR -5.6 +/- 2.1% versus WKY rats -20.0 +/- 2.1%; heart rate: SHR -5.4 +/- 0.88% versus WKY rats -9.2 +/- 2.3%; sympathetic nerve activity: SHR -5.5 +/- 1.1% versus WKY rats -21 +/- 2.8%). Micro-injection of an A2 agonist into the nucleus tractus solitarius also decreased blood pressure and heart rate, and those responses were not inhibited by pretreatment with an adenosine A1-specific antagonist. The response induced by micro-injection of A2 agonist into the nucleus tractus solitarius was significantly smaller in SHR than in WKY rats, whereas the changes in heart rate did not differ statistically (blood pressure: -23.4 +/- 4.7% versus -10.8 +/- 2.1%; heart rate: -12.1 +/- 1.2% versus -13.6 +/- 2.1%).

CONCLUSION

The present results suggest that stimulation of adenosine A2 receptors in the nucleus tractus solitarius decreases both blood pressure and inhibitory sympathetic nerve activity and that those inhibitory responses to adenosine in the nucleus tractus solitarius are deranged in SHR.

[Clinical implications of mismatched uptakes of beta-methyl fatty acid analogue and thallium in infarcted myocardium: correlations with coronary stenosis and regional wall motion abnormality]

Myocardial perfusion and fatty acid metabolism were assessed by using myocardial single-photon emission computed tomography with thallium and beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) during acute and/or late stages of myocardial infarction in 157 infarcted segments of 100 patients. The incidence of reduced thallium perfusion relative to BMIPP uptake ("T-type" mismatch) was significantly (p < 0.05) lower (9%) compared to that of reduced BMIPP uptake relative to thallium perfusion ("B-type" mismatch) (59%) or non-mismatched segment (32%). In an anteroseptal region, B-type dissociation had a significantly higher incidence compared to no or T-type mismatch; 68% vs. 27% vs. 5%, respectively, whereas the incidence of T-type uptake was relatively high in inferior and posterolateral regions; 13%, 11%, respectively. Severe coronary stenosis was observed in 76% of B-type segments and 72% of non-mismatched segments but in only 43% of T-type segments. The incidence of regional wall motion abnormality was significantly lower (46%) in the T-type mismatch segments when compared to the B-type (91%) or non-mismatched segments (96%). In conclusion, myocardial fatty acid metabolism was more markedly impaired compared to an involved coronary perfusion, resulting in the mismatch of perfusion and fatty acid metabolism. Coronary stenosis and regional wall motion abnormality are more closely related to "B-type" mismatch but not necessarily to "T-type" dissociation, probably because of attenuation artifacts in inferior and posterolateral regions in thallium scan.

KIF3A/B: a heterodimeric kinesin superfamily protein that works as a microtubule plus end-directed motor for membrane organelle transport

We cloned a new member of the murine brain kinesin superfamily, KIF3B, and found that its amino acid sequence is highly homologous but not identical to KIF3A, which we previously cloned and named KIF3 (47% identical). KIF3B is localized in various organ tissues and developing neurons of mice and accumulates with anterogradely moving membranous organelles after ligation of nerve axons. Immunoprecipitation assay of the brain revealed that KIF3B forms a complex with KIF3A and three other high molecular weight (approximately 100 kD)-associated polypeptides, called the kinesin superfamily-associated protein 3 (KAP3). In vitro reconstruction using baculovirus expression systems showed that KIF3A and KIF3B directly bind with each other in the absence of KAP3. The recombinant KIF3A/B complex (approximately 50-nm rod with two globular heads and a single globular tail) demonstrated plus end-directed microtubule sliding activity in vitro. In addition, we showed that KIF3B itself has motor activity in vitro, by making a complex of wild-type KIF3B and a chimeric motor protein (KIF3B head and KIF3A rod tail). Subcellular fractionation of mouse brain homogenates showed a considerable amount of the native KIF3 complex to be associated with membrane fractions other than synaptic vesicles. Immunoprecipitation by anti-KIF3B antibody-conjugated beads and its electron microscopic study also revealed that KIF3 is associated with membranous organelles. Moreover, we found that the composition of KAP3 is different in the brain and testis. Our findings suggest that KIF3B forms a heterodimer with KIF3A and functions as a new microtubule-based anterograde translocator for membranous organelles, and that KAP3 may determine functional diversity of the KIF3 complex in various kinds of cells in vivo.

[123I-metaiodobenzylguanidine myocardial scintigraphy in a case of pheochromocytoma before and after resection of it]

A 55-year-old man with pheochromocytoma was examined by 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy before and after resection of the tumor. MIBG images showed decreased uptake in infero-posterior wall before operation. The heart to upper mediastinum uptake ratio was low at the delayed anterior planar image, and mean MIBG clearance from the left ventricle was increased. These abnormal scintigraphic findings improved after resection of the tumor. We thought that these abnormal MIBG findings were not due to abnormal cardiac sympathetic nerve function, because ECG, chest X-ray, UCG and 201Tl myocardial scintigram did not reveal any abnormality. It may be presumed that these abnormal MIBG findings were caused by high plasma catecholamines concentration. The mechanism of abnormal MIBG findings of the heart remains uncertain in various heart diseases. MIBG findings in this case with pheochromocytoma before and after resection may contribute to interpretation of the kinetics of MIBG in heart.

Young borderline hypertensives are hyperreactive to mental arithmetic stress: spectral analysis of R-R intervals

To investigate whether sympathetic tone and its reactivity to stress are increased in borderline hypertension, we compared pressor and autonomic nervous responses to mental arithmetic stress in male borderline hypertensives (BH) and normotensive volunteers (NT). Three age groups, 30, 40 and 50-year-old groups, which included 30 to 39, 40 to 49 and 50 to 59-year-old subjects, were studied. Fractional LF (%LF), fractional HF (%HF) and L/H, obtained from the power spectrum of R-R intervals, were used as indices of autonomic nervous function. Baseline autonomic nervous indices did not differ between NT and BH of any age group. Blood pressure rose higher during mental arithmetic stress in 50 than in 30-year-old NT but not in comparable age groups of BH. Pressor responses were augmented in BH compared to NT only in the 30-year-old group. However, the differences were not significant when pressor responses were expressed as percent increases in blood pressure. Both %L and L/H increased during arithmetic stress. The increase in %L did not differ between NT and BH but that in L/H (% delta L/H) was larger in 50 than in 30-year-old NT. % delta L/H was larger in BH than in NT only in the 30-year-old group. These findings suggest that both pressor and autonomic nervous responses to metal arithmetic stress were altered by aging and augmented in BH compared to NT in the 30-year-old group.

[Prediction of left ventricular functional recovery in patients with acute myocardial infarction using single photon emission computed tomography with thallium-201 and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid]

The relationships between myocardial perfusion, fatty acid metabolism, and cardiac function were investigated using dual single photon emission computed tomography (SPECT) with thallium and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) during the acute (10 +/- 1 days) and recovery (60 +/- 14 days) phases in 29 patients with acute myocardial infarction. There were 18 patients who underwent successful primary coronary angioplasty (PTCA group) and 11 patients who received conservative therapy (non PTCA group). Thallium and BMIPP uptakes were scored visually by a 4-point system and left ventricular ejection fraction (LVEF) was calculated by radionuclide ventriculography. Although significant positive correlations between thallium and 123I-BMIPP scores were observed during both phases, BMIPP scores were significantly lower than thallium scores in both acute and recovery phases in the PTCA group. No significant difference in thallium and 123I-BMIPP scores was observed at the recovery phase in the non PTCA group. LVEF significantly correlated with thallium and 123I-BMIPP scores in both phases in the PTCA group. Furthermore, the difference between thallium and 123I-BMIPP scores during the acute phase significantly correlated with the improvement of LVEF during the follow-up period in the PTCA group (y = 0.92x-0.77, r = 0.65, p < 0.005). These findings suggest that mismatch of perfusion and metabolism in infarcted myocardium assessed by thallium and 123I-BMIPP SPECT is increased by reperfusion therapy and persists at least until the recovery phase of myocardial infarction. The recovery of left ventricular function depends on the extent of the mismatched uptake, indicating a predictor for functional recovery following acute myocardial infarction.

Correlations of antimyosin accumulation and histological manifestation of myocyte necrosis at different stages of idiopathic cardiomyopathy

Although antimyosin uptake has been demonstrated in idiopathic cardiomyopathy, discrepancies between antimyosin positivity and histological examinations using biopsy speciments have been found. In order to investigate the correlations between antimyosin localization and histopathological alterations, the magnitude and distribution of antimyosin uptake were quantitatively assessed in aged-matched control (F1b) and hereditary idiopathic cardiomyopathy (Bio 14.6) hamsters at three different ages. In these studies, gamma counting and macroautoradiography were compared with histological alterations. Myocardial activities and percent areas of antimyosin uptake were significantly (P<0.05) greater in 10-, 20-, and 30-week old Bio groups than in their respective control groups. Autoradiograms showed that antimyosin antibody was relatively localized, massive, and scattered in 10-week-old, 20-week-old and 30-week-old Bio hamsters, respectively. Histopathology demonstrated antimyosin positivity not only in necrotic myocytes and accompanying calcium deposits but also in tissues showing inflammatory reactions but no histologically identifiable myocyte necrosis. In conclusion, antimyosin uptake seen in tissues with age-related disease processes did not necessarily correspond to histologically verified myocyte necrosis in the cardiomyopathy hearts, suggesting that antimyosin positivity reflects myocytes which show impaired sarcolemmal integrity but have not yet undergone myolysis.

Cardiac sympathetic denervation in transthyretin-related familial amyloidotic polyneuropathy: detection with iodine-123-MIBG

In familial amyloidotic polyneuropathy (FAP), the peripheral nervous system is predominantly impaired. Cardiac sympathetic function has not been directly assessed. A 65-yr-old man with severe peripheral neuropathy due to primary systemic amyloidosis was studied. Echocardiograms and scintigraphic examinations with 20Tl and 99mTc-pyrophosphate demonstrated highly thickened but normally perfused left ventricular walls with intense diffuse amyloid deposits. No definite myocardial activity of [123I]metaiodobenzylguanidine (MIBG) was detected in any cardiac region, indicating lack of sympathetic nerve endings. Despite maintained cardiac contractility, left ventricular diastolic performance and heart rate variability assessed by power spectral analysis were markedly depressed. Thus, the myocardial defect of MIBG activity may provide direct evidence of impaired cardiac sympathetic nerve endings due to amyloid deposits in FAP.

Role of basic and acidic fragments in delicious peptides (Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala) and the taste behavior of sodium and potassium salts in acidic oligopeptides

The role of the acidic fragment (Asp-Glu-Glu) in delicious peptides was investigated in detail by using the Na+ or K+ salts of acidic oligopeptides so that amount of Na+ or K+ intake of peptides composed of acidic amino acids could be varied by changing their sequences. The taste of these peptides was confirmed to vary with Na+ or K+ intake. Additionally, in order to study the role of basic (Lys-Gly) and acidic (Asp-Glu-Glu) fragments in delicious peptides for producing the taste, five delicious peptide analogs, Ser-Leu-Ala-Lys-Gly-Asp-Glu-Glu, Ser-Leu-Ala-Asp-Glu-Glu-Lys-Gly, Lys-Gly-Ser-Leu-Ala-Asp-Glu-Glu, Lys-Gly-Asp-Glu-Glu, and Glu-Glu-Asp-Gly-Lys, were synthesized. The intensity of the umami and/or salty taste of these peptides and their Na salts was almost the same, despite their chemical structures being different. These results indicate that the acidic fragment as well as the basic fragment plays an important role in the taste production and intensity of delicious peptides, and that an umami or salty taste can be produced by the localization of the cation of the basic fragment and the anion of the acidic fragment.

The functional role of 55- and 75-kDa tumour necrosis factor receptors in human polymorphonuclear cells in vitro

The expression and biological role of 55- and 75-kDa tumour necrosis factor-receptors (TNF-RI and TNF-RII) in human polymorphonuclear cells (PMN) in vitro were studied using agonistic rabbit polyclonal anti-TNF-R antibodies. PMN express TNF-RII predominantly, and release the superoxide anion on stimulation by human recombinant lymphotoxin (LT) in vitro. Anti-TNF-RI but not anti-TNF-RII antibody stimulated the superoxide release mimicking LT. Release of the elastase from azurophilic granule of PMN was augmented by LT in vitro. Anti-TNF-RI but not anti-TNF-RII antibody augmented the elastase release. Release of the lactoferrin from the specific granules of PMN was enhanced by LT in vitro. Anti-TNF-RI but not anti-TNF-RII antibody augmented the elastase release. Release of the lactoferrin from the specific granules of PMN was enhanced by LT in vitro. Anti-TNF-RI but not anti-TNF-RII antibody enhanced the lactoferrin release. These antibodies failed to co-stimulate these PMN functions. The adhesiveness of PMN to a plastic plate and the expression of Mac-1 on PMN were upregulated by LT in vitro. Anti-TNF-RI but not anti-TNF-RII antibody upregulated the adhesiveness and Mac-1 expression of PMN mimicking LT. Though anti-TNF-RII antibody by itself did not alter the adhesiveness and marginally suppressed Mac-1 expression, it maintained the adhesiveness and adhesion molecule expression in the presence of anti-TNF-RI antibody. In summary, PMN predominantly express TNF-RII, the signalling of LT (and TNF) in PMN is mediated mainly by TNF-RI, and the adhesion function can be modulated also by TNF-RII when TNF-RI is stimulated.