Loss of programmed cell death 4 induces apoptosis by promoting the translation of procaspase-3 mRNA.

The programmed cell death 4 (Pdcd4), a translation inhibitor, plays an essential role in tumor suppression, but its role in apoptosis remains unclear. Here we show that Pdcd4 is a critical suppressor of apoptosis by inhibiting the translation of procaspase-3 mRNA. Pdcd4 protein decreased more rapidly through microRNA-mediated translational repression following apoptotic stimuli than did the activation of procaspase-3, cleavage of poly(ADP)ribose polymerase (PARP) by active caspase-3, and nuclear fragmentation. Strikingly, the loss of Pdcd4 by the specific RNA interference increased procaspase-3 expression, leading to its activation and PARP cleavage even without apoptotic stimuli, and sensitized the cells to apoptosis. Thus, our findings provide insight into a novel mechanism for Pdcd4 as a regulator of apoptosis.

Variation during the week in the incidence of acute myocardial infarction: increased risk for Japanese women on Saturdays.

BACKGROUND: Variations in the incidence of acute myocardial infarction during the week may differ between and within communities, according to lifestyle. OBJECTIVE: To identify potential triggering factors for acute myocardial infarction by examining variations in incidence in the days of the week within the Osaka area of Japan. PATIENTS: Of 2511 consecutive patients in this region who were admitted to hospital for acute myocardial infarction between April 1998 and March 2001 and consented to take part, 2400 who had a definitely identified time of onset were enrolled. RESULTS: For this group as a whole, no significant difference in incidence was noted between days of the week. However, in subgroup analyses women were shown to have significant variation through the week, peaking on Saturday with a 39% increase in relative risk (p = 0.037); working subjects showed a peak on Monday, with a 26% increase in relative risk (p = 0.038). Stratified analyses showed that in working men there was a prominent Monday peak in the onset of infarction, with a 30% increase in relative risk (p = 0.022), while in working women, there was no significant variation through the week. CONCLUSIONS: Earlier findings of a Monday peak linked to increased physical and mental occupational stress are confirmed. There is also an increase in uncertain risk factors on Saturdays for Japanese women, possibly involving a stressful weekend burden for women. Confirmation of this finding in other communities may help identify triggers of acute myocardial infarction and be useful in prevention.

Directed evolution of biphenyl dioxygenase: emergence of enhanced degradation capacity for benzene, toluene, and alkylbenzenes.

Biphenyl dioxygenase (Bph Dox) catalyzes the initial oxygenation of biphenyl and related compounds. Bph Dox is a multicomponent enzyme in which a large subunit (encoded by the bphA1 gene) is significantly responsible for substrate specificity. By using the process of DNA shuffling of bphA1 of Pseudomonas pseudoalcaligenes KF707 and Burkholderia cepacia LB400, a number of evolved Bph Dox enzymes were created. Among them, an Escherichia coli clone expressing chimeric Bph Dox exhibited extremely enhanced benzene-, toluene-, and alkylbenzene-degrading abilities. In this evolved BphA1, four amino acids (H255Q, V258I, G268A, and F277Y) were changed from the KF707 enzyme to those of the LB400 enzyme. Subsequent site-directed mutagenesis allowed us to determine the amino acids responsible for the degradation of monocyclic aromatic hydrocarbons.

Nicorandil, a hybrid between nitrate and ATP-sensitive potassium channel opener, preconditions human heart to ischemia during percutaneous transluminal coronary angioplasty.

The human heart progressively becomes more tolerant to ischemia after repeated balloon inflations during percutaneous transluminal coronary angioplasty (PTCA). The present study investigated whether nicorandil, a hybrid between nitrate and an ATP-sensitive potassium channel opener, affects this ischemic preconditioning. Sixteen patients with stable angina pectoris caused by left anterior descending artery lesions were subjected to 2 balloon inflations of 2-min duration with a 3-min reperfusion period. Seven of these patients served as the control group and in the remaining 9 patients, nicorandil was administered intravenously (6 mg/h) throughout the PTCA procedure (nicorandil group). The lactate extraction ratio (LER) was obtained at 30 s after each ischemic event (LERpost-1 and LERpost-2) in both groups. In the control group, LERpost-1 was more negative than LERpost-2 (-185.7+/-74.2 vs -98.0+/-37.3%, p<0.01). The ratio of the sum of the ST elevation in the precordial leads during the second inflation (sumST-2, 0.94+/-0.66 mV) to that during the first inflation (sumST-1, 1.43+/-1.17 mV) was 0.72+/-0.16 in the control group, which was less than the ratio in the nicorandil group (1.06+/-0.13, p<0.01). Nicorandil abolished the difference between the 2 ischemic events (LERpost-1, -45.1+/-41.6 vs LERpost-2, -43.5+/-51.1%; sumST-1, 1.38+/-0.80 vs sumST-2, 1.46+/-0.90 mV). LER was less negative in the nicorandil group than that in the control group (LERpost-1, -45.1+/-41.6 vs -185.7+/-74.2%, p<0.01; LERpost-2, -43.5+/-51.1 vs -98.0+/-37.3%, p<0.05). Thus, nicorandil improved lactate metabolism during PTCA without significantly influencing ST-elevation. In conclusion, intravenous pre-administration of nicorandil appears to precondition the human heart during PTCA.

Transcardiac 8-iso-prostaglandin F(2 alpha)generation from acute myocardial infarction heart: insight into abrupt reperfusion and oxidant stress.

8-iso-prostaglandin F(2 alpha)(8-iso-PGF(2 alpha)), a representative isoprostane, has been reported to be a reliable marker for oxidant stress in vivo. To examine if 8-iso-PGF(2 alpha)is generated in patients with acute myocardial infarction (AMI), we measured the level of immunoreactive 8-iso PGF(2 alpha)in the great cardiac vein as well as classical eicosanoids, 6-keto-prostaglandin F(1 alpha)(6-keto-PGF(1 alpha)) and thromboxane B(2)(TXB(2)) in the process of urgent coronary balloon angioplasty. Fourteen patients with anterior AMI were divided into two groups: the totally occluded (n=7) and the already perfused groups (n=7). In the former, transient elevation of 8-iso-PGF(2 alpha)was observed immediately after the angioplasty, i.e. the ratio of post-angioplasty level to pre-level was approximately 2.4 for 8-iso-PGF(2 alpha), 14 for 6-keto-PGF(1 alpha), and 5 for TXB(2). In the already perfused group, the levels of these eicosanoids were unchanged. In the totally occluded group, peak creatine phosphokinase in a peripheral vein was correlated with the level of 8-iso-PGF(2 alpha)(r(2)=0.841, P<0.01), but not with those of the other two eicosanoids. In conclusion, transcardiac 8-iso-PGF(2 alpha)generation is a reliable marker for the size of myocardium exposed to oxidant stress.

Impact of coronary risk factors on contribution of nitric oxide and adenosine to metabolic coronary vasodilation in humans.

OBJECTIVES: The contribution of nitric oxide (NO) and adenosine to the increase in coronary blood flow (CBF) induced by cardiac pacing was investigated in 28 subjects with angiographically normal coronary arteries with and without one or more risk factors for atherosclerosis. BACKGROUND: NO and adenosine are important in the regulation of coronary circulation, and the inhibition of NO synthesis increases adenosine production during cardiac pacing in experimental models. METHODS: Coronary artery diameters and CBF were assessed by quantitative coronary arteriography and Doppler flow velocity measurement. Plasma levels of nitrites and nitrates (NOx) (stable end products of NO), adenosine and lactate were measured, and blood gas analysis was performed. RESULTS: The extent of CBF response to cardiac pacing did not differ between the 14 subjects with and the 8 subjects without risk factors for atherosclerosis. NOx (12.0+/-0.9 vs. 14.9+/-1.1 ,amol/liter [mean+/-SD], p < 0.05), but not adenosine (50.8+/-7.2 vs. 50.8+/-6.5 nmol/liter), levels in coronary sinus blood increased in the subjects without risk factors. In contrast, adenosine (58.9+/-7.5 vs. 77.4+/-9.8 nmol/liter, p < 0.05), but not NOx (11.1+/-1.1 vs. 12.2+/-1.1 micromol/liter), levels increased in subjects with risk factors. Aminophylline, an antagonist of adenosine receptors, blunted CBF response to cardiac pacing in six subjects with risk factors. The number of risk factors showed a negative correlation (p < 0.05) with NOx production and a positive correlation (p < 0.05) with adenosine production during cardiac pacing, respectively. CONCLUSIONS: NO and adenosine are increased during metabolic coronary vasodilation induced by cardiac pacing. Adenosine production may be a compensatory mechanism when NO production is reduced.

Intravascular ultrasonic evidence by constant cross-sectional area of atherosclerotic plaques during coronary vasomotion in humans.

AIMS: This study aims to visualize ultrasonically deformation of atherosclerotic plaques in human coronary arteries during vasoconstriction and vasodilatation. METHODS AND RESULTS: Intravascular ultrasound detected occult atherosclerosis in angiographically normal coronary arteries of eight patients with chest pain at rest. During the acetylcholine provocative test, intravascular ultrasound monitored deformation of the atherosclerotic plaques. At the last step of the test, intracoronary injection of isosorbide dinitrate caused vasodilation. Under control, acetylcholine-treated, and isosorbide dinitrate-treated conditions, cross-sectional areas of sonolucent circle and vessel lumen were measured. Subtraction of the latter from the former gave the area of atherosclerotic plaque. In the process of vasoconstriction and vasodilation, the plaque area did not change significantly. CONCLUSION: The cross-sectional area of the atherosclerotic plaque appeared to be constant during vasomotion of human coronary arteries.

Effect of theophylline on adaptation of the heart to myocardial ischemia during percutaneous transluminal coronary angioplasty in patients with stable angina pectoris.

This study was designed to examine whether theophylline, an adenosine receptor antagonist, affects cardiac adaptation to ischemia during progression of repetitive balloon inflations of percutaneous transluminal coronary angioplasty (PTCA). Theophylline abolished this cardiac adaptation, suggesting that endogenous adenosine is a key mediator for cardiac adaptation during PTCA.

Acute and reversible fatty metamorphosis of cultured rat hepatocytes.

Rat hepatocyte cell line M6, B347 and J525, among which only M6 is slightly deviated from diploidy, showed marked microvesicular fatty metamorphosis in response to treatment with Tweens at concentrations of 0.05-0.025% in Eagle's minimum essential medium (MEM). Within 24 h treated cells became fatty at 100% in frequency and filled with small lipid droplets, as revealed by fat staining or at the ultrastructural level. Fatty hepatocytes, however, took again non-fatty morphology 72 h after withdrawal of Tweens from the culture medium. Growth of the cell exhibited mild retardation at the early phase of the treatment but almost similar cell density to that of control cells was achieved 24 h after the treatment. Other detergents without fatty-acid moiety, including NP-40, triton X-100, sodium deoxycholic acid and sodium cholic acid, were ineffective to induce fatty change. Oleate, a fatty-acid moiety of Tween 80 or 85, and linolate caused reversible fatty metamorphosis of the cell lines at concentrations of 1.9 x 10(4) mol/L or more and 3.8 x 10(4) mol/L or more, respectively. Ethanol induced mild steatosis of the cell lines and enhanced fatty change by linolate. Hepatic fatty acid-binding protein was not detected in the cell lines before or after the induction of fatty change. These results indicate that fatty acid itself is directly incorporated in cultured rat hepatocytes and expelled 3 days later without apparent cell degeneration.

Expression of lipocalin-type prostaglandin D synthase (beta-trace) in human heart and its accumulation in the coronary circulation of angina patients.

Lipocalin-type prostaglandin D synthase (L-PGDS) is localized in the central nervous system and male genital organs of various mammals and is secreted as beta-trace into the closed compartment of these tissues separated from the systemic circulation. In this study, we found that the mRNA for the human enzyme was expressed most intensely in the heart among various tissues examined. In human autopsy specimens, the enzyme was localized immunocytochemically in myocardial cells, atrial endocardial cells, and a synthetic phenotype of smooth muscle cells in the arteriosclerotic intima, and accumulated in the atherosclerotic plaque of coronary arteries with severe stenosis. In patients with stable angina (75-99% stenosis), the plasma level of L-PGDS was significantly (P < 0.05) higher in the great cardiac vein (0.694 +/- 0.054 microg/ml, n = 7) than in the coronary artery (0.545 +/- 0.034 microg/ml), as determined by a sandwich enzyme immunoassay. However, the veno-arterial difference in the plasma L-PGDS concentration was not observed in normal subjects without stenosis. After a percutaneous transluminal coronary angioplasty was performed to compress the stenotic atherosclerotic plaques, the L-PGDS concentration in the cardiac vein decreased significantly (P < 0.05) to 0.610 +/- 0.051 microg/ml at 20 min and reached the arterial level within 1 h. These findings suggest that L-PGDS is present in both endocardium and myocardium of normal subjects and the stenotic site of patients with stable angina and is secreted into the coronary circulation.

Expression of immunoreactivities to 75 kDa nerve growth factor receptor, trk gene product and phosphotyrosine in granular cell tumors.

Nineteen granular cell tumors (GCT) of adults, two congenital granular cell epulides and five epulides fibrosae were immunohistochemically examined to detect the expression of 75 kDa nerve growth factor receptor (NGFR), trk gene product, phosphotyrosine (PT), protein gene product 9.5 (PGP9.5) and S-100 protein. The NGFR-immunoreactivity (IR) and trk gene product-IR were expressed on almost all granular cells of GCT. PT-IR was also demonstrated on granular cells of all GCT examined, although the frequency of positive cells was low. Congenital granular cell epulides and epulides fibrosae were negative for NGFR-IR, trk gene product-IR and PT-IR. S-100 protein was localized in granular cells of adult GCT but not in the granular cells of congenital epulis. On the other hand, PGP9.5 was detected in granular cells of both conditions and in fibroblastic cells of epulis fibrosa. The present results further indicate that GCT is of peripheral nerve Schwann cell origin, while the congenital granular cell epulides are not of neural origin. NGFR and trk gene product expressed on GCT seems to be functional in terms of phosphorylation of the tyrosine residue in the receptor or downstream protein in signal transduction.

Neoplastic endocrine cells in prostatic carcinoma: a case report with immunocytochemical and electron microscopic findings.

A case of a 68-year-old male with prostatic carcinoma which was partially well differentiated but largely poorly differentiated is presented in this report. The poorly differentiated area of the adenocarcinoma seemed to arise from the well-differentiated portion. The former was populated with Grimelius argyrophilic cells, and occasionally contained round, eosinophilic intracytoplasmic inclusions which appeared to be composed of a secretory substance. Immunocytochemistry revealed that endocrine cells were present in the normal portion of the gland as well as in the well-differentiated adenocarcinoma, but were more numerous in the poorly differentiated portion. The latter portion was positive for chromogranin A, endocrine granule constituents, neuroendocrine markers, serotonin, Leu 7, ACTH and neuron specific enolase. In addition, cells of poorly differentiated portion were reactive with CEA, prostatic acid phosphatase and human prostate specific antigen. Ultrastructural features observed in the poorly differentiated adenocarcinoma included five kinds of round neurosecretory granules. This was a rare case of prostatic adenocarcinoma in which the evolution from well differentiated to poorly differentiated tissue containing neuroendocrine constituents could be clearly observed.

A case of glomangiosarcoma.

A case of glomangiosarcoma (GS) arising on the lateral side of the left upper arm is reported here. GS is very rare compared with benign glomus tumor (GT) and there has been some controversy regarding whether it is a true malignant tumor. Histologically, the tumor consisted of two different components. In the periphery of the tumor, a solid sheet-like growth of small cuboidal cells identical to benign GT was seen. However, in the central portion, the tumor was composed of short spindle cells with hyperchromatic atypical nuclei arranged in weak fascicles, mimicking leiomyosarcoma. Mitotic figures were not uncommon in the latter area. Immunohistochemistry revealed that both cuboidal and spindle-shaped tumor cells were positive for vimentin and muscle actin as were cells of other benign GTs used for controls. In addition, only spindle-shaped cells expressed protein produced by the suppressive oncogene p53 in the nuclei, a phenomenon not seen in the five benign GTs or in cuboidal cells of GS. These results suggest that GS may exhibit more aggressive behavior than benign GT.

[Multiple myeloma with massive ascites fluid--immunophenotypic analysis of myeloma cell and its IL-6-dependent growth].

A 75-year-old female was diagnosed as having multiple myeloma (IgG.lambda type. Stage IIA) with plasmacytoma of the head and back in October, 1989. She obtained partial remission by MCNU and MP therapy, but relapsed with massive ascites in January, 1991. VAD therapy was not effective and she died of multiple organ failure on February 23. Her ascites contained a large number of myeloma cells, and the phenotypic analysis and the response to interleukin-6 (IL-6) of these myeloma cells were examined. The myeloma cells were positive for CD33, CD45, CD45RA, CD63, CD71, plasma cell associated antigens such as CD38, PCA-1, BL3, and various kinds of adhesion molecules: CD11a/CD18 (LFA-1), CD29 (VLA-beta 1), CD44 (H-CAM), CD49d (VLA-4), CD54 (ICAM-1), CD56 (N-CAM), CD58 (LFA-3). IL-6 level in the ascites was increased at 91.0pg/ml. The myeloma cells showed an IL-6 dependent growth, which was inhibited by anti-IL-6 antibody (Ab) and anti-IL-6 receptor Ab in vitro. Myeloma cells appearing in ascites have rarely been reported. Our case suggested that IL-6 was a potent growth factor of myeloma cells through an autocrine mechanism in the ascites, and resulted in an aggressive myeloma.

Tissue characterization of pneumonia and irradiated rat lungs with magnetic resonance relaxation times.

To interpret the MRI signal intensities, the T1 and T2 values were determined in vitro for rat lungs with radiation pneumonitis, fibrosis or pneumonia, and also for muscle and fat tissues. The transverse magnetization decays mentioned above exhibited two components, a T2 fast (T2f) and a T2 slow (T2s) component. Lungs from rats with pneumonia had significantly longer T2f and T2s values than lungs from rats with radiation pneumonitis and fibrosis. The T2f and T2s values for a "pneumonia lung" were not significantly different from those of muscle. The measured values of T2f and T2s suggested that radiation pneumonitis and fibrosis likely exhibit lower signal intensities than do muscle and that a "pneumonia lung" likely exhibits a similar signal intensity to that of muscle on T2-weighted MR images.

Elevated neutrophil function in chronic neutrophilic leukemia.

A 65-year-old man with marked leukocytosis was admitted for diagnosis and treatment. His peripheral blood leukocyte count was 37,500/microliters and the leukocytes consisted of mature neutrophil-like cells. A high neutrophil alkaline phosphatase score and a normal bone marrow cell karyotype suggested that the patient had chronic neutrophilic leukemia rather than chronic myeloid leukemia. Several neutrophil functions, such as superoxide production, nitroblue tetrazolium reduction activity, and phagocytosis, were elevated. These data and the morphological features (toxic granules and Döhle bodies) indicated that the patient's neutrophils were in an activated stage.

T cell activation and T cell receptor variable region gene usage in measles.

T cell activation and T cell receptor variable (V) regions were studied with monoclonal antibodies in peripheral blood lymphocytes from 22 patients with measles. Increased (greater than 5%) activated T cells (HLA-DR+ CD3+ cells) were noted in 14 of the 22 patients. Elevations of V beta 5+ and V beta 8+ T cells were observed in two and four patients, respectively, and appeared to be associated with T cell activation. The duration of fever was significantly prolonged in those with increased (greater than 10%) activated T cells (p less than 0.01). These results suggest that T cell activation and the preferential expansion of V beta 8+ and V beta 5+ T cells are associated with the pathogenic process of measles.

Recurrent parotid swelling in children: clinical features useful for differential diagnosis of Sjögren's syndrome.

Immunological evaluations were performed in 59 children with at least five episodes of parotid swelling. Autoantibody(ies) was transiently or persistently detected in 12 (20%) of 59 patients with recurrent parotitis. Three of the 12 children with autoantibodies were diagnosed as having Sjögren's syndrome. The mean age at onset of parotid swelling in Sjögren's syndrome was significantly higher than that of recurrent parotitis of unknown etiology. The present study and the review of the literature suggest that patients with the onset of parotid swelling at age five years or over deserve screening for underlying systemic immune disorders.