The effects of using a leukocyte removal filter during cold blood cardioplegia

During myocardial ischemia, neutrophils and platelets exert negative effects on the myocardium. In this study, we used a leukocyte removal filter during cardioplegia, and investigated its effect on myocardial damage during reperfusion by measuring the plasma levels of granulocyte components, platelet components, and cardiac enzymes [creatinine phosphokinase (CK) and creatinine phosphokinase myocardial band (CK-MB)] in 24 patients who underwent cardiopulmonary bypass. The patients were divided into two groups of 12 according to whether or not a filter was placed in the cardioplegic route. Blood samples were drawn directly from the coronary sinus before aortic cross clamping, and at 1, 5, and 15 min after declamping. Group F, which had the filter, showed better cardiac enzyme and lipid peroxidation results than group N, which did not. The results of this study suggest that the application of a filter during cold blood cardioplegia may reduce myocardial damage.

Expression of p53 protein in gastric carcinomas is not independently prognostic

BACKGROUND

Biologic significance of p53 protein expression in gastric carcinomas is unclear. The relationship between p53 expression and survival after curative operations for gastric carcinoma was evaluated.

METHODS

Paraffin-embedded specimens from 135 patients who underwent curative resection of gastric carcinoma were analyzed immunohistochemically for p53 expression.

RESULTS

Immunoreactivity of p53 was found in 37 of 135 gastric tumors. Six of 48 early gastric carcinomas expressed focally scattered p53. Pattern of p53 expression in the majority of advanced carcinomas was diffuse. In univariate analyses a significant relationship with survival was found for tumor size (p < 0.01), depth of invasion (p < 0.01), nodal involvement (p < 0.01), and p53 expression (p < 0.01). Significant relationships were found between p53 expression and nodal involvement (p < 0.01) and depth of invasion (p < 0.01). A multivariate analysis revealed that the independent predictors of recurrence were nodal involvement (p = 0.009) and depth of invasion (p = 0.009). In a logistic multiple regression analysis p53 expression was not independently related to the parameters, which suggests an aggressive tumor.

CONCLUSIONS

Our results suggest that p53 expression did not correlate with the aggressiveness of gastric carcinomas and failed to be an independent predictor of outcome.

Interleukin-3 and bryostatin-1 mediate hyperphosphorylation of BCL2 alpha in association with suppression of apoptosis

Using murine myeloid factor-dependent FDC-P1/ER cells, we demonstrate that the hematopoietic growth factors interleukin-3 and erythropoietin and bryostatin-1, a macrocyclic lactone natural product and potent activator of protein kinase C (PKC), suppress apoptosis and induce the rapid serine phosphorylation of Bc12 alpha. Expression of recombinant wild type Bc12 alpha in NFS/N1.H-7 cells confirms that murine Bc12 alpha is phosphorylated following PKC activation. The PKC inhibitors H-7 and staurosporine, but not the protein kinase A inhibitor HA1004, block not only interleukin-3- and bryostatin-1-induced hyperphosphorylation of Bc12 alpha but also their anti-apoptotic effect on growth factor-dependent cells, suggesting a role for activated PKC in both processes. A potential direct role for a classic isoform of PKC is indicated by the Ca(2+)-dependent nature of phosphorylation of Bc12 alpha mediated by purified PKC in vitro. Comparative phosphopeptide maps confirm that Bc12 alpha phosphorylation occurs on identical serine site(s) whether phosphorylation occurs in cells following agonist treatment or directly by PKC in vitro. These findings strongly support a role for activated PKC in growth factor-induced Bc12 alpha phosphorylation as well as suppression of apoptosis.

Selectivity of isoprenoid-containing imidazole antifungal compounds for sterol 14-demethylase P450 (P450(14)DM) and 7-ethoxycoumarin O-deethylase P450 of rat liver microsomes

The imidazole antifungal compound AFK-108 (1-[2-(2,4-dichlorophenyl)-2-((2E)-3,7-dimethylocta-2,6- dienyloxy)ethyl]-1H-imidazole) has been shown to be a potent inhibitor for yeast lanosterol 14 alpha-demethylase (P450(14)DM), interacting specifically with the sterol side-chain recognition part of the substrate site through its geranyl moiety. AFK-108 acted as a potent inhibitor for rat liver P450(14)DM, while its farnesyl (AFK-110) and prenyl (AFK-122) homologues were weak inhibitors. This indicates that AFK-108 interacts with rat liver P450(14(DM in the same manner as with the yeast enzyme. However, the difference between the potency of AFK-108 and the homologues was greater in rat P450(14)DM than in the yeast enzyme. AFK-108 and its homologues partially inhibited 7-ethoxycoumarin O-deethylase activity of rat liver microsomes. The order of potency was AFK-122 > AFK-108 > AFK-110, indicating that some steric hindrance of the isoprenoid moiety might affect their potency. The inhibitory effect of AFK-108 for P450(14)DM was considerably higher than for 7-ethoxycoumarin O-deethylase P450, while the inhibition of AFK-110 and AFK-122 on these enzymes was of the same order of magnitude. These results suggest that azole compounds interacting with the side-chain recognition site of P450(14)DM may be good candidates as antifungal agents selective for fungal P450(14)DM.

[Preliminary clinical results of surgery for type A acute aortic dissections using gelatin-resorcin-formaldehyde glue]

We used gelatin-resorcin-form-aldehyde (GRF) glue to fuse the false lumen of type A acute aortic dissection in four patients. All were operated on within 3-24 hours after onset, and gluing of the two cylinders of the dissecting aorta could be done safely in a short time. Initial intimal tears were located in the transverse aorta in three patients and in the proximal descending aorta in one. Simple transection and end-to-end anastomosis of the ascending aorta was done for the first two cases. But in the last two patients, we resected the intimal tear in the transverse aorta and applied GRF glue to the stump of the aortic arch and to that of the aortic root, followed by graft replacement of the ascending aorta. There were no hospital deaths. But we had to reoperate on one patient five months after the first operation due to potentially residual dissection in the aortic root. GRF glue is a very useful adhesive for acute aortic dissection operations, but further refinement of the operative technique using it is necessary.

Elevated plasma soluble interleukin 2 receptor level correlates with defective natural killer and CD8+ T-cells in myelodysplastic syndromes

The plasma soluble interleukin 2 receptor (sIL-2R) level and its relationships with haematologic and immunologic data were examined in 40 patients with myelodysplastic syndromes (MDS). The plasma sIL-2R level was significantly higher in the high-risk MDS group (refractory anaemia with excess blasts (RAEB), RAEB in transformation and chronic myelomonocytic leukaemia) than in the low-risk MDS group (refractory anaemia (RA) and RA with ringed sideroblasts) or in normal subjects, although there was considerable variation in the plasma sIL-2R level within each MDS group. The plasma sIL-2R level correlated positively with the bone marrow cellularity and bone marrow blast mass, but not with the absolute number of CD25+ lymphocytes. This may support the idea that plasma sIL-2R is derived from malignant MDS cells in the bone marrow. The plasma sIL-2R level correlated negatively with the absolute numbers of the CD8+, CD3-CD16+, and CD3-CD56+ cell populations in freshly isolated lymphocytes, the percentage of CD3-CD56+ cells in lymphokine (interleukin 2)-activated killer (LAK) cells, and the cytotoxicity of LAK cells. We conclude that MDS patients having a high plasma sIL-2R level often have a defect in natural killer and CD8+ T-cells.

Two amidophosphoribosyltransferase genes of Arabidopsis thaliana expressed in different organs

Amidophosphoribosyltransferase (ATase: EC 2.4.2.14) is a key enzyme in the pathway of purine nucleotide biosynthesis. We have identified several cDNA clones whose amino acid sequences exhibit similarity with the known ATases in a cDNA library of young floral buds of Arabidopsis thaliana. The cDNA clones are derived from two genes homologous with each other. These cDNAs represent the first plant representatives of ATase gene. Structural comparison with ATases of other organisms has revealed that the two genes encode [4Fe-4S] cluster-dependent ATases. Northern blot analysis showed that expression level of the genes is different in three organs; one gene is expressed in flowers and roots, while the other gene is mainly expressed in leaves.

Effect of fluvastatin sodium on secretion of very low density lipoprotein and serum cholesterol levels. In vivo study using low density lipoprotein receptor deficient watanabe heritable hyperlipidemic rabbits

The hypolipidemic effects of fluvastatin sodium (XU 62-320, CAS 93957-55-2), a new 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, were examined. Fluvastatin sodium was administered to Watanabe heritable hyperlipidemic (WHHL) rabbits, a low density lipoprotein (LDL) receptor deficient animal model, for 6 weeks at doses of 12.5 mg/kg, 25 mg/kg, and 50 mg/kg. Total cholesterol levels in serum, in very low density lipoproteins (VLDL), in intermediate density lipoprotein, and in LDL decreased dose-dependently. In the 50 mg/kg group, cholesterol reduction in each of the aforementioned segments was 50%, 91%, 94% and 33%, respectively. The secretion rate of VLDL-cholesterol, as determined by intravenous injection of Triton WR-1339, also decreased in a dose-dependent manner, showing a reduction of 16% (p < 0.05) in the 50 mg/kg group. In addition, the cholesterol content of newly-secreted VLDL also decreased dose-dependently. These results indicate that fluvastatin sodium has a potent hypolipidemic effect, and suggest that one of the mechanisms responsible for the reduction of serum cholesterol may be the suppression of VLDL-cholesterol secretion.

Molecular diversity of three S-allele cDNAs associated with gametophytic self-incompatibility in Lycopersicon peruvianum

We isolated S allele-associated cDNA clones from each of the stylar cDNA libraries of Lycopersicon peruvianum of two different S genotypes (S12Sb and S13Sc) with S11Sa allele-associated cDNA (LPS11) as a probe. The longest cDNA clones, designated LPS12 and LPS13, which were 779 bp and 853 bp in length, contained open reading frames of 189 and 210 amino acids, respectively. The three S allele-associated cDNAs (LPS11, LPS12, and LPS13) did not cross-hybridize to each other under highly stringent condition by northern blot analysis. Their average identity to Nicotiana alata S-proteins so far was 49%. The fragments corresponding to LPS11 or LPS12 cosegregated with their respective S alleles in genetic crosses. From these results, we conclude that the three cloned cDNAs were derived from the three different S alleles of L. peruvianum.

A special-purpose computer for molecular dynamics: GRAPE-2A

Molecular dynamics simulations have been extensively used in research of proteins. Since these simulations are quite computer intensive, their acceleration is of main interest of the research. In molecular dynamics simulations, almost all computing time is consumed in calculating the forces between particles, e.g., Coulomb and van der Waals forces. We have designed and built GRAPE-2A (GRAvity PipE 2A), a special-purpose computer for use in simulations of classical many-body systems. GRAPE-2A calculates forces exerted on a particle from the other particles. GRAPE-2A can calculate force of an arbitrary functional form of a central force. The host computer, which is connected to GRAPE-2A through the VME bus, performs other calculations such as time integration. The peak speed of GRAPE-2A is 180 Mflops. We can also stimulate systems with periodic boundary conditions by the Ewald method, using GRAPE-2A and another special-purpose computer, WINE (Wave space INtegrator for the Ewald method).

Characterization of signaling pathways to Na+/H+ exchanger activation with epidermal growth factor in hepatocytes

To investigate the signaling pathways to Na+/H+ exchanger activation with epidermal growth factor in hepatocytes, we measured changes in cytosolic free calcium and intracellular pH levels at the single-cell level using digital imaging fluorescence microscopy of fura-2- or BCECF-loaded hepatocytes in primary culture. Epidermal growth factor induced cytosolic free calcium oscillations consisting of periodic trains of spikes with a latency period of up to several minutes. These calcium responses were inhibited by tyrosine kinase inhibitor genistein (100 mumol/L) and abolished by emptying of intracellular Ca2+ pools with 3 mumol/L thapsigargin, an inhibitor of Ca(2+)-ATPase on the endoplasmic reticulum. Epidermal growth factor (1 nmol/L) induced an intracellular pH increase of 0.12 +/- 0.07 units from the basal level of 7.25 +/- 0.09 units after several minutes of latency. This effect was completely abolished by 1 mmol/L amiloride, an inhibitor of the Na+/H+ exchanger. The epidermal growth factor-induced intracellular pH increase was inhibited by pretreatment of hepatocytes with genistein (100 mumol/L), thapsigargin (3 mumol/L) or calmodulin inhibitor W-7 (25 mumol/L), but not with protein kinase C inhibitor H-7 (50 mumol/L) or with cyclic AMP-dependent kinase inhibitor H-8 (60 mumol/L). Phorbol ester PMA (phorbol 12-myristate 13-acetate), a potent activator of protein kinase C, induced a slight intracellular pH increase significantly smaller than that with epidermal growth factor, whereas this effect was completely blocked by pretreatment with H-7, indicating that PMA-induced intracellular pH increase is mediated by protein kinase C pathways, unlike epidermal growth factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluorescent differential display: arbitrarily primed RT-PCR fingerprinting on an automated DNA sequencer

We established robust, reliable protocols for 'Differential Display (DD),' an RNA fingerprinting method originally developed by Liang and Pardee [(1992) Science 257, 967-971] using RT-PCR with arbitrary primers. Our protocols are optimized so that reliable DD analysis can be performed on a fluorescent DNA sequencer to ensure high throughput as well as improved operational safety, compared with the original one using radioactive compounds. Such 'Fluorescent Differential Display (FDD)' techniques will accelerate the identification of differentially expressed as well as polymorphic transcripts to address various biological questions.

[Relative accuracy of Thermoscan PRO-1 in patients under general anesthesia]

The relative accuracy of Thermoscan PRO-1 (Thermoscan, USA), an infrared ear thermometer, in an unadjusted mode was examined in 21 patients under general anesthesia, using the esophageal and tympanic membrane temperatures as the reference values. The correlation coefficient between the temperature measured by Thermoscan PRO-1 and the esophageal temperature, and that between the temperature measured by Thermoscan PRO-1 and the tympanic membrane temperature, were 0.953 and 0.942, respectively (P < 0.01). The "limits of agreement" between the temperature measured by Thermoscan PRO-1 and esophageal temperature, and between the temperature measured by Thermoscan PRO-1 and tympanic membrane temperature, were -0.5-0.4 degrees C and -0.5-0.5 degrees C, respectively. We conclude that Thermoscan PRO-1 is sufficiently reliable for monitoring body temperature during surgery.

Potential for transmission of avian influenza viruses to pigs

Pandemic strains of influenza A virus arise by genetic reassortment between avian and human viruses. Pigs have been suggested to generate such reassortants as intermediate hosts. In order for pigs to serve as 'mixing vessels' in genetic reassortment events, they must be susceptible to both human and avian influenza viruses. The ability of avian influenza viruses to replicate in pigs, however, has not been examined comprehensively. In this study, we assessed the growth potential of 42 strains of influenza virus in pigs. Of these, 38 were avian strains, including 27 with non-human-type haemagglutinins (HA; H4 to H13). At least one strain of each HA subtype replicated in the respiratory tract of pigs for 5 to 7 days to a level equivalent to that of swine and human viruses. These results indicate that avian influenza viruses with or without non-human-type HAs can be transmitted to pigs, thus raising the possibility of introduction of their genes into humans. Sera from pigs infected with avian viruses showed high titres of antibodies in ELISA and neutralization tests, but did not inhibit haemagglutination of homologous viruses, cautioning against the use of haemagglutination-inhibition tests to identify pigs infected with avian influenza viruses. Co-infection of pigs with a swine virus and with an avian virus unable to replicate in this animal generated reassortant viruses, whose polymerase and HA genes were entirely of avian origin, that could be passaged in pigs. This finding indicates that even avian viruses that do not replicate in pigs can contribute genes in the generation of reassortants.

[A diagnosis of venous anomaly with dextrocardia by magnetic resonance imaging and transesophageal echocardiography]

A 56-year-old woman was admitted with the chief complaint of dyspnea. Chest radiograph and echocardiography disclosed mirror image dextrocardia with massive pleural effusion. Magnetic resonance imaging (MRI) and transesophageal echocardiography (TEE) revealed dilated coronary sinus and persistent right-sided superior vena cava which entered the coronary sinus. These findings were compatible with those of digital subtraction angiography. Anomalies of the venous system must be recognized before surgery because adequate venous drainage is essential for extra-corporeal circulation. MRI and TEE are noninvasive and useful methods and should be performed first to detect anomalies of the venous system associated with dextrocardia.

[Insertion of prosthetic tricuspid valve two years after the tricuspid valvulectomy]

A case of a 14-year-old boy who underwent a prosthetic tricuspid valve insertion two years after the tricuspid valvulectomy due to intractable right-sided active endocarditis is presented. At the initial operation, the tricuspid valve was thoroughly resected because of marked destruction and attachment of vegetations, and a concomitant ventricular septal defect was directly closed. When a prosthetic valve was placed in the tricuspid portion, a semicircular Dacron patch was attached to the right side of the interventricular septum in a fashion of up-chord and down-arc to cover the bundle of His. The straight edge of the patch was located near the AV node and was not sutured to the tricuspid valve annulus. A 31 mm of CarboMedics prosthetic valve was sutured to the tricuspid valve annulus and to the free edge of the patch at the position near the AV node to prevent AV block. Postoperative course was uneventful and ECG showed regular sinus rhythm.

Ca2+/calmodulin-dependent protein kinase kinase cascade

Recently we obtained evidence for the existence of Ca2+/calmodulin-dependent protein kinase kinase (CaMKK), which was partially purified in the process of the purification step of Ca2+/calmodulin-dependent protein kinase V (CaM kinase V). This enzyme promoted phosphorylation of the autophosphorylation site on CaM kinase V and activated the activity (Mochizuki, H. et al. (1993) Biochem. Biophys. Res. Commun. 197, 1595-1600). Present study revealed that CaMKK also phosphorylated CaM kinase IV associated with the activation of its activity. Phosphorylation of CaM kinase IV by CaMKK occurred on multiple sites. Furthermore, CaM kinase IV and CaM kinase V phosphorylated each other which resulted in their activation. The phosphorylation site of CaM kinase V by CaM kinase IV was the same as the autophosphorylation site. Our study suggests the existence of a heretofore CaM kinases cascade consisting of a sequential activation of each CaM kinase.

Interleukin 3 stimulates protein synthesis by regulating double-stranded RNA-dependent protein kinase

In a murine interleukin 3 (IL-3)-dependent cell line, IL-3 deprivation resulted in increased autophosphorylation of double-stranded RNA-dependent protein kinase (PKR) that has been reported to inhibit protein synthesis by phosphorylating the alpha subunit of eukaryotic initiation factor 2 (eIF-2 alpha). Autophosphorylation was characterized by a shift up in mobility of PKR on SDS/PAGE gels from a 60- to a 64-kDa form. In vitro kinase studies comparing the autophosphorylated 64-kDa PKR with the nonphosphorylated 60-kDa PKR confirmed that only the 64-kDa form was active for eIF-2 alpha phosphorylation. PKR activation in vivo was associated with phosphorylation of eIF-2 alpha and inhibition of protein synthesis. Addition of IL-3 to deprived cells elicited a reciprocal response characterized by the rapid dephosphorylation of PKR and eIF-2 alpha, indicating inactivation of PKR. This was rapidly followed by the full recovery of protein synthesis. Furthermore, upon IL-3 addition, a 97-kDa phosphotyrosine-containing protein becomes rapidly and transiently associated with PKR prior to dephosphorylation of PKR and eIF-2 alpha. Genistein, a tyrosine kinase inhibitor, blocks both phosphorylation of the 97-kDa phosphoprotein and protein synthesis after IL-3 addition, suggesting a role for the 97-kDa phosphoprotein in the mechanism of inactivation of PKR and stimulation of protein synthesis. Thus, IL-3 appears to positively regulate protein synthesis by inducing the inactivation of PKR in a growth factor signaling pathway.

Characterization of murine CD34, a marker for hematopoietic progenitor and stem cells

CD34 is expressed on human hematopoietic stem and progenitor cells, and its clinical usefulness for the purification of stem cells has been well established. However, a similar pattern of expression for murine CD34 (mCD34) has not yet been determined. Two polyclonal anti-mCD34 antibodies that specifically recognize both endogenous and recombinant murine CD34 were developed to characterize the mCD34 protein and to determine its pattern of expression on murine cell lines and hematopoietic progenitor cells. Fluorescence-activated cell sorter analysis showed that mCD34 is expressed on NIH/3T3 embryonic fibroblasts, PA6 stromal cells, embryonic stem cells, M1 leukemia cells, and a subpopulation of normal bone marrow cells. Murine CD34 was found to be a glycoprotein expressed on the cell surface as either a full-length (approximately 100 kD) or truncated (approximately 90 kD) protein in NIH/3T3 and PA6 cells. Recombinant full-length CD34, when expressed in the CHO-K1 cell line, had a molecular weight of approximately 105 kD. Full-length CD34 expressed on M1 leukemia cells, had a higher apparent molecular weight (110 kD). These results suggest that there are glycosylation differences between CD34 expressed by different cell types. The full-length form, but not the truncated form, is a phosphoprotein that is hyperphosphorylated in response to 12-0-Tetradecanoyl phorbol 13-acetate treatment, suggesting potential functional differences between the two forms. Selection of the 3% highest-expressing CD34+ bone marrow cells enriched for the hematopoietic precursors that form colony-forming unit-spleen (CFU-S), CFU-granulocyte-macrophage, and burst-forming unit-erythroid. Transplantation of lethally irradiated mice with these cells demonstrated both short- and long-term repopulating ability, indicating that this population contains both functional hematopoietic progenitors and the putative stem cell. These antibodies should be useful to select for murine hematopoietic stem cells.