Evaluation of myocardial viability using sequential dual-isotope single photon emission tomography imaging with rest TI-201/stress Tc-99m tetrofosmin in the prediction of wall motion recovery after revascularization

In patients with coronary artery disease (CAD), differentiation between severely ischemic but potentially viable myocardium and irreversibly infarcted tissue is clinically important, particularly when revascularization procedures are considered. Although thallium (TI) cardiac imaging has been shown to be a good tool for investigating myocardial viability in CAD, this tracer shows physical limitations, such as a low photon energy and long half-life. We assessed the results of a rest TI-201/stress Tc-99m tetrofosmin protocol in subjects with prior anterior myocardial infarction. All of the patients had an akinetic or dyskinetic area and more than 75% stenosis in the left anterior descending artery. All of the patients underwent revascularization after the examination. We evaluated the improvement in wall motion after revascularization using the centerline method with contrast left ventricular angiography. Fourteen patients showed reversible defects with the rest TI-201/stress Tc-99m tetrofosmin protocol or in additional TI-201 24 h redistribution images. All 14 patients showed a significant improvement in wall motion after revascularization. Dual-isotope rest TI-201/stress Tc-99m tetrofosmin single photon emission tomography data, acquired separately, may give fast and complete information about myocardial perfusion during stress and at rest, and on about myocardial viability.

Domain-specific phosphorylation of vimentin and glial fibrillary acidic protein by PKN

PKN is a serine/threonine protein kinase with a catalytic domain homologous to the protein kinase C family and unique N-terminal leucine zipper-like sequences. Using analyses with the yeast two-hybrid system and in vitro binding assay, we found that the regulatory domain of PKN interacted with vimentin. We then examined whether PKN would phosphorylate vimentin in vitro. Vimentin proved to be an excellent substrate for PKN, and the phosphorylation of vimentin by PKN occurred in the head domain with the result of a nearly complete inhibition of its filament formation in vitro. Similar results were also obtained with another type III intermediate filament protein, glial fibrillary acidic protein (GFAP). These results raise the possibility that PKN may regulate filament structures of vimentin and GFAP by domain-specific phosphorylation.

Hypoxia-induced ABR change and heat shock protein expression in the pontine auditory pathway of young rabbits

The auditory brainstem response (ABR) was compared with the immunohistochemical expression of heat shock protein (HSP-72) and microtubule-associated protein 2 (MAP-2) of the brainstem auditory pathway in young rabbits subjected to hypoxic stress. Severe hypoxia for 2 h produced significant prolongation and decreased amplitude of the later component of ABR. HSP-72 expression was distinctly increased in the cochlear nucleus, but there was less induction in the inferior colliculus under severe hypoxia. MAP-2 immunostaining of neuropiles in the inferior collicular nucleus was decreased slightly after severe-long hypoxia, but cytoplasmic staining did not change. The present ABR change, which was produced by brainstem hypoxia-ischemia and acidosis, may be due to the neural cytoarchitectural derangement and less induction of stress proteins in the upper brainstem.

[Developmental dyslexia and dysgraphia--a case report]

We reported a 7-year-old, right-handed boy whose reading and writing of kana and kanji were impaired. He also showed a severe deficit in visuo-spatial perception skills. Nevertheless, his ability to read and write kana characters was facilitated by means of the Japanese Syllabaries. It is generally considered that the Syllabary involve two kinds of language modalities: auditory-verbal and visuo-verbal language systems. In spite of his intact auditory-verbal language system, his visuo-verbal language skills involved in writing kanji were severely impaired. It was suggested that a severe deficit of visuo-spatial perception skills influenced performance of visuo-verbal language systems. Accordingly, we inferred that the patient recalled a kana character by use of the Japanese Syllabaries based on his good auditory-verbal language system, and supposed that his reading and writing disorders were similar to alexia with agraphia in adult patients with angular lesions.

Biochemical differences between staurosporine-induced apoptosis and premature mitosis

Apoptosis is morphologically related to premature mitosis, an aberrant form of mitosis. Staurosporine, a potent protein kinase inhibitor, induces not only apoptotic cell death in a wide variety of mammalian cells but also premature initiation of mitosis in hamster cells that are arrested in S phase by DNA synthesis inhibitors. Here we report on the biochemical differences between the two phenomena commonly caused by staurosporine. Rat 3Y1 fibroblasts that had been arrested in S phase with hydroxyurea underwent apoptosis by treatment with staurosporine, whereas S-phase-arrested CHO cells initiated mitosis prematurely when similarly treated with a low concentration of staurosporine. Chromosome condensation occurred in both apoptosis (3Y1) and premature mitosis (CHO). However, neither formation of mitotic spindles nor mitosis-specific phosphorylation of MPM-2 antigens was observed in apoptosis of 3Y1 cells, unlike premature mitosis of CHO cells. The p34cdc2 kinase activated in normal and prematurely mitotic cells remained inactive in the apoptotic cells, probably because the active cyclin B/p34cdc2 complex was almost absent in the S-phase-arrested 3Y1 cells. The absence of intracellular activation of p34cdc2 in apoptosis was confirmed by immunohistochemical analyses using a specific antibody raised against Ser55-phosphorylated vimentin which is specifically phosphorylated by p34cdc2 during M phase. Furthermore, phosphorylation of histones H1 and H3, which is associated with mitotic chromosome condensation, did not occur in the apoptotic cells. These results indicate that the two phenomena, staurosporine-induced apoptosis and premature mitosis, are different in their requirement for p34cdc2 kinase activation and histone phosphorylation.

Phosphorylation of glial fibrillary acidic protein at the same sites by cleavage furrow kinase and Rho-associated kinase

Site- and phosphorylation state-specific antibodies are useful to analyze spatiotemporal distribution of site-specific phosphorylation of target proteins in vivo. Using several polyclonal and monoclonal antibodies that can specifically recognize four phosphorylated sites on glial fibrillary acidic protein (GFAP), we have previously reported that Thr-7, Ser-13, and Ser-34 on this intermediate filament protein are phosphorylated at the cleavage furrow during cytokinesis. This observation suggests that there exists a protein kinase named cleavage furrow kinase specifically activated at metaphase-anaphase transition (Matsuoka, Y., Nishizawa, K., Yano, T., Shibata, M., Ando, S., Takahashi, T., and Inagaki, M. (1992) EMBO J. 11, 2895-2902; Sekimata, M., Tsujimura, K., Tanaka, J., Takeuchi, Y., Inagaki, N., and Inagaki, M. (1996) J. Cell Biol. 132, 635-641). Here we report that GFAP is phosphorylated specifically at Thr-7, Ser-13, and Ser-34 by Rho-associated kinase (Rho-kinase), which binds to the small GTPase Rho in its GTP-bound active form. The kinase activity of Rho-kinase toward GFAP is dramatically stimulated by guanosine 5'-(3-O-thio)-triphosphate-bound RhoA. Furthermore, the phosphorylation of GFAP by Rho-kinase results in a nearly complete inhibition of its filament formation in vitro. The possibility that Rho-kinase is a candidate for cleavage furrow kinase is discussed.

Modulation of endothelin-induced intracellular Ca2+ mobilization by interleukin-1 beta and lipopolysaccharide in C6 rat glioma cells

We have investigated the effects of interleukin (IL)-1 beta and lipopolysaccharide (LPS) on endothelin (ET)-induced intracellular Ca2+ rise in C6 rat glioma cells in order to study the mechanisms of their effects on Ca2+ signaling systems. Pretreatment with IL-1 beta (10(3) U/mL) and LPS (1 microgram/mL) for 24 h significantly inhibited 100 nM ET-1-induced increase in intracellular Ca2+ either in the presence or absence of external Ca2+. Their inhibitory effects were in dosedependent (IL-1 beta; 50-1000 U/mL, LPS; 10-1000 ng/mL) and time-dependent (12-24 h) manners. A tyrosine kinase antagonist genistein (50 microM) but not a protein kinase C inhibitor H7 (30 microM) prevented the inhibition of the ET response by IL-1 beta and LPS. These results suggest that activation of tyrosine kinase may be essential for the inhibition of the ET receptor-mediated Ca2+ signaling systems by IL-1 beta and LPS.

The influence of peri-operative blood transfusion during radical hysterectomy on the prognosis of uterine cervical cancer

To evaluate the clinical implications of peri-operative transfusion in the surgical treatment of uterine cervical cancer, a detailed analysis of the cumulative survival rate was performed using clinical data from 145 patients with FIGO stage Ib cervical cancer of the squamous cell type acquired between 1982 and 1989 at the Center for Adult Diseases. The cumulative survival rate was statistically analyzed using the Kaplan Meier method. Of the 145 patients with stage Ib cancer, 103 were considered to have undergone complete excision and received no further treatment post-operatively, and 42 were considered to have undergone incomplete excision because of the involvement of lymph nodes or the lymphovascular space. Of the 79 patients in the former group who received peri-operative transfusion, 69 received less than seven units (1400 mL) and 10 received more than eight units (1600 mL). The cumulative 5-year survival rate was 100% in the 24 patients who received no transfusions, 91.7% in those who received less than 1400 mL, and 90.0% in those who received more than 1600 mL. Similarly, of the 42 patients in the incomplete excision group, nine did not receive any peri-operative transfusion, 27 received less than 1400 mL, and six received more than 1600 mL. The 5-year survival rate in these groups was 88.9, 77.8 and 50.0%, respectively. The survival rate of our patients with stage Ib cervical cancer without peri-operative transfusion was significantly higher than that of those with transfusion, regardless of post-operative irradiation therapy status, indicating that peri-operative transfusion has an adverse influence on the prognosis in cervical cancer.

Phosphorylation-dependent control of structures of intermediate filaments: a novel approach using site- and phosphorylation state-specific antibodies

Site-specific phosphorylation of intermediate filament (IF) proteins on serine and threonine residues leads to dynamic alterations in filament structure. Site- and phosphorylation state-specific antibodies for IF proteins can visualize spatial and temporal distribution of site-specific IF protein phosphorylations in the cell. These antibodies are also useful to identity IF kinases involved in cellular events, including cell signaling and cell cycle.

Myosin binding subunit of smooth muscle myosin phosphatase at the cell-cell adhesion sites in MDCK cells

We examined the intracellular localization of the myosin binding subunit (MBS) of smooth muscle myosin phosphatase. In MDCK cells in a confluent monolayer of polarized epithelial sheet, MBS was concentrated to the cell-cell adhesion sites. Double-immunofluorescence analysis with anti-MBS and anti-beta-catenin antibodies showed that MBS was mainly localized at the adherens junction. Furthermore, MBS was translocated reversibly between the cytosol and the cell-cell adhesion sites during the formation and disappearance of cell-cell contacts. These data suggest that MBS may play an important role in the regulation of the cell-cell adhesion.

Biochemical and cellular effects of roscovitine, a potent and selective inhibitor of the cyclin-dependent kinases cdc2, cdk2 and cdk5

Cyclin-dependent kinases (cdk) play an essential role in the intracellular control of the cell division cycle (cdc). These kinases and their regulators are frequently deregulated in human tumours. Enzymatic screening has recently led to the discovery of specific inhibitors of cyclin-dependent kinases, such as butyrolactone I, flavopiridol and the purine olomoucine. Among a series of C2, N6, N9-substituted adenines tested on purified cdc2/cyclin B, 2-(1-ethyl-2-hydroxyethylamino)-6-benzylamino-9-isopropylpurine (roscovitine) displays high efficiency and high selectivity towards some cyclin-dependent kinases. The kinase specificity of roscovitine was investigated with 25 highly purified kinases (including protein kinase A, G and C isoforms, myosin light-chain kinase, casein kinase 2, insulin receptor tyrosine kinase, c-src, v-abl). Most kinases are not significantly inhibited by roscovitine. cdc2/cyclin B, cdk2/cyclin A, cdk2/cyclin E and cdk5/p35 only are substantially inhibited (IC50 values of 0.65, 0.7, 0.7 and 0.2 microM, respectively). cdk4/cyclin D1 and cdk6/cyclin D2 are very poorly inhibited by roscovitine (IC50 > 100 microM). Extracellular regulated kinases erk1 and erk2 are inhibited with an IC50 of 34 microM and 14 microM, respectively. Roscovitine reversibly arrests starfish oocytes and sea urchin embryos in late prophase. Roscovitine inhibits in vitro M-phase-promoting factor activity and in vitro DNA synthesis in Xenopus egg extracts. It blocks progesterone-induced oocyte maturation of Xenopus oocytes and in vivo phosphorylation of the elongation factor eEF-1. Roscovitine inhibits the proliferation of mammalian cell lines with an average IC50 of 16 microM. In the presence of roscovitine L1210 cells arrest in G1 and accumulate in G2. In vivo phosphorylation of vimentin on Ser55 by cdc2/cyclin B is inhibited by roscovitine. Through its unique selectivity for some cyclin-dependent kinases, roscovitine provides a useful antimitotic reagent for cell cycle studies and may prove interesting to control cells with deregulated cdc2, cdk2 or cdk5 kinase activities.

Safety and effectiveness of exercise training in patients with silent myocardial ischemia

The effectiveness of exercise training in patients with silent myocardial ischemia was examined. Forty patients with coronary heart disease (mean age 55 +/- 8 years) were recruited for a 12-week exercise training program. All patients underwent treadmill exercise stress testing, exercise thallium-201 single photon emission computed tomography and left heart catheterization. They were divided into three groups based on the symptoms and the results of exercise thallium scintigraphy, i.e., painful myocardial ischemia (PMI group), silent myocardial ischemia (SMI group), and non-myocardial ischemia (NMI group). Normalized treadmill time was longer in the SMI group (108 +/- 24%) than in the PMI group (86 +/- 14%, p < 0.05). All 40 patients, 14 from the PMI group, 16 from the SMI group and 10 from the NMI group, completed the whole exercise training program. A significant prolongation of treadmill time was attained in all three groups after exercise training [PMI group: from 494 +/- 105 to 632 +/- 78 sec (p < 0.05), SMI group: from 609 +/- 147 to 746 +/- 137 sec (p < 0.05), NMI group: from 572 +/- 112 to 739 +/- 13 sec (p < 0.05)]. The improvement of myocardial ischemia following exercise training was similar in the SMI and PMI groups. No adverse effects were detected throughout the program. The exercise training program adopted in this study proved safe and effective in patients with silent myocardial ischemia.

Effects of ganglioside GD1a on the fluidity and phase transition of phosphatidylcholine model membrane immobilized on porous cellulose acetate filter

The thermotropic effect of ganglioside GD1a on the phosphatidylcholine membrane immobilized on the porous cellulose acetate filter was investigated by ESR spin-labeling and DSC. The spin-labeled GD1a having 12-DOXYL-stearic acid instead of the long acyl chain of the ceramide portion (GD1a*) was incorporated into the model membrane. An ESR examination of the membrane showed that GD1a* undergoes an anisotropic rotation in the wide range of temperature -30-70 degrees C. By monitoring the overall splitting (2T parallel) of spin-labeled phosphatidylcholine (PC*), the model membranes were found to show decreased fluidity in accordance with the GD1a content. The phase transition temperature (Tm) of distealoylphosphatidylcholine (DSPC) model membranes could be estimated by the measurement of ESR and DSC. The effects of GD1a were found to be more significant in broadening the phase transition rather than in elevating the Tm of DSPC model membranes.

An effective tool to detect lesions causing unstable angina with multivessel disease: iodine-123-betamethyl-p-iodophenyl-pentadecanoic acid single photon emission computed tomography

Radiolabeled fatty acids such as iodine-123-betamethyl-p-iodophenyl-pentadecanoic acid (BMIPP) have unique metabolic properties suggesting potential use as myocardial perfusion tracers. The uptakes of BMIPP and thallium 201 were compared using single photon emission computed tomography (SPECT) in 24 patients displaying unstable angina with multivessel disease at a mean of 3.4 days after admission. Coronary angiography was performed within a week. Uptake was considered normal if the activity was greater than 80% of the normal area, mildly reduced if 50% to 79%, and severely reduced if less than 50%. The regional activities in four quardrants in short-axis slices were measured from basal, mid and apical sets. We attempted to identify the causative lesion on dual SPECT imaging. We planned the following management of each patient based on the results of the dual SPECT study. BMIPP activity imaging found 4 segments (1.4%) with severe decrease, 70 (24.3%) with mild decrease, and 214 (74.3%) with normal uptake. In contrast, T1 activity imaging showed normal uptake in 68 of 74 abnormal BMIPP activity segments. Furthermore, all segments with abnormal BMIPP uptake were matched with locations of coronary artery stenosis by coronary angiography. Accordingly, coronary revascularization (percutaneous transluminal coronary angioplasty, coronary artery bypass grafting) was performed based on BMIPP SPECT. Reductions in BMIPP activity were common in patients with unstable angina with multivessel disease. BMIPP SPECT is an excellent tool for detecting the causative lesion in unstable angina. The subsequent intervention could be performed with less risk based on the strategy of dilating the only causative lesion which was detected by the BMIPP SPECT in patients with multivessel disease displaying unstable angina.

High-power fourth- and fifth-harmonic generation of a Nd:YAG laser by means of a CsLiB(6)O(10)

High pulse energies of nanosecond-level fourth- and fifth-harmonic (4omega and 5omega) generation of a Nd:YAG laser have been obtained with a CsLiB(6)O(10) (CLBO) nonlinear crystal. 500 mJ of 4omega output with a conversion efficiency of 50% from the second-harmonic input was generated. 5omega output at 213 nm of as high as 230 mJ was obtained by sum-frequency generation of the 266- and 1064-nm beams, corresponding to a 10.4% conversion efficiency of the initial fundamental input energy. The characteristics of the CLBO crystal that permit this effective frequency conversion are discussed.

[A specific disorder in Kanji writing in a learning disabled child with a visual cognition disorder--a cognitive-neuropsychological and electrophysiological analysis]

We reported a learning disabled child with a specific disorder involving Kanji writing. The patient was a 13-year-old boy. Although he manifested generally normal intellectual ability and his performance on WISC-R indicated that VIQ was 101 and PIQ 84, he could only write approximately 20% of Kanji, which he learned at age 6 to 7. On cognitive-psychological tests, he showed a visual cognition disorder that was different from that in a previously reported case during information processing. Electrophysiologically, he showed a disorder in visual task-relevant potentials. The mechanism underlying this patient appears to be a retrieval disorder for complex graphic forms in addition to a visual cognition disorder because of two reasons. One is that he could distinguish Kanji from similar graphic forms. The other is that he could read Kanji aloud.

Visualization of protein kinase activities in single cells by antibodies against phosphorylated vimentin and GFAP

Vimentin and glial fibrillary acidic protein (GFAP) are intermediate filament proteins expressed in the cytoplasm of various types of cells. The head domains of these proteins are phosphorylated by various protein kinases. Site- and phosphorylation-specific antibodies which recognize a phosphorylated serine/threonine residue in the head domains and its flanking sequence provide a useful tool to monitor and visualize protein kinase activities in single cells.

Facile reaction of gangliosides with hydroxyl radical

The reactivity of gangliosides with superoxide anion (O2(•-)) and hydroxyl radical (HO(•)) was evaluated by ESR spin-trapping using 5,5-dimethyl-1-pyrroline-N-oxide under physiological conditions (1/15 M phosphate buffer, pH 7.4). Gangliosides proved to react with HO(•) but not with O2(•-). The second order rate constants for various gangliosides with HO(•) ranged from 5 × 10(9) M(-1)s(-1) to 16 × 10(9) M(-1)s(-1). The rate constant for tetrasialoganglioside, GQ1b, was about three times higher than that of monosialoganglioside, GM1. The reactivity of gangliosides and asialo-GM1 with HO(•) was in the order: GQ1b >GT1b >GD1a >GD1b = GM1 ≫ asialo-GM1. The observed high reactivity of gangliosides probably involves the sialyl residues, since sialic acid was shown to be more reactive with HO(•) than d-glucose under the same conditions.

Tc-99m tetrofosmin myocardial perfusion SPECT after dipyridamole combined with low-level exercise in the diagnosis of coronary artery disease

Tc-99m tetrofosmin is a lipophilic, cationic perfusion imaging agent that changes to Tl-201 in detecting coronary artery disease during exercise testing. The purpose of this study is to evaluate the usefulness of Tc-99m tetrofosmin dipyridamole stress imaging combined with low level exercise for the detection of coronary artery disease. We examined 42 patients and 10 normal volunteers who also underwent coronary angiography. A one-day protocol was used: in the stress study, 296 MBq of tetrofosmin was injected and in the rest study 888 MBq was injected. After intravenous administration of dipyridamole (0.142 mg/kg/min for 4 minutes), the patient was exercised on a bicycle ergometer for 3 min (25 Watts). Tetrofosmin was injected 2 minutes after dipyridamole infusion during the exercise. Single photon emission computed tomographic images were obtained 30 minutes after the tracer injection. Images were interpreted as abnormal in 36 of 42 patients with coronary artery disease, and normal in all of 10 normal volunteers. The overall sensitivity of detection of coronary artery disease was 83.3% and the normalcy rate was 100%. The diagnostic values for the detection of significant stenosis in the three major arteries were: LAD sensitivity 83%, specificity 92%; LCX sensitivity 47%, specificity 91%; RCA sensitivity 75%, specificity 83%. Of the 66 arteries with more than 50% stenosis, 48 arteries were correctly identified. Of the 36 with more than 70% stenosis, 31 were identified. Scintigraphic evidence of multivessel disease was found in only 9 patients (50%). A protocol of Tc-99m tetrofosmin SPECT combined with low level exercise after dipyridamole is therefore useful for the detection of the coronary artery disease.