Do structural changes of T cell receptor complex occur in tumor-bearing state?

T cells in tumor-bearing mice and cancer patients were recently shown to be devoid of CD3-zeta chain, a signal-transducing invariant chain in T cell receptor (TCR) complex, and p56lck tyrosine kinase. In the present study, we investigated the structure and function of TCR complex in T cells from BALB/c mice bearing CSA1M fibrosarcoma. The expressions of TCR chains and p56lck in a T cell-enriched population from spleen were analyzed. Almost complete loss of CD3-zeta and p56lck was observed in the preparation from tumor-bearing mice as assessed by immunoblotting analysis using whole cell lysates, whereas the amounts of other TCR chains were relatively unchanged. However, these changes were due to the increase of contaminating Mac-1+ cells in the spleen of tumor-bearing mice because: 1) the removal of Mac-1+ cells led to the restoration of CD3-zeta and p56lck; and 2) CD3-zeta was clearly present when the preparation was solubilized with ionic detergent. Fc receptor gamma chain detected in the preparation from tumor-bearing mice disappeared along with the removal of Mac-1+ cells. These observations were further supported by the finding that addition of Mac-1+ cells from tumor-bearing mice to normal T cells resulted in loss of CD3-zeta, leaving CD3-epsilon largely intact. When T cells from tumor-bearing mice were highly purified by depletion of Mac-1+ cells, these T cells contained normal amounts of CD3-zeta at mRNA, protein, and surface levels, and expressed the properly assembled TCR complex on their cell surface. Moreover, stimulation of the TCR in these T cells by anti-TCR antibodies resulted in a comparable Ca2+ mobilization to that observed in normal T cells. These results suggest that no structural changes occur in TCR complex in our tumor-bearing mice, and that complete depletion of Mac-1+ cells in important to assess the structure of TCR complex.

[Treatment of aneurysm of aortic arch using selective cerebral perfusion]

The objective of this study is to evaluate safety and efficacy of the selective cerebral perfusion (SCP) for an adjunct to perform operation of aortic arch aneurysms. From November 1982 to June 1993, surgical treatment of aneurysm of aortic arch using SCP was performed in 22 patients. The hospital death was accounted in 5 cases (23%), the intraoperative stroke was observed in 3 cases (14%) and these patients died. The cause of intraoperative stroke was cerebral hypoperfusion due to multiple sclerosis of intracranial arteries or insufficient SCP. Variables of an increased operative risk seemed to be older age (over 70 y.o.) and rupture. SCP time more than 120 minutes did not promote the operative risk. Cerebral hypoperfusion was directly responsible for not only intraoperative stroke, but also operative death. Therefore, SCP seems effective and safe if hypoperfusion is prevented.

Inhaled nitric oxide and extracorporeal membrane oxygenation in persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn (PPHN) may occasionally require an invasive treatment with extracorporeal membrane oxygenation (ECMO). Inhaled nitric oxide (NO) has recently been introduced as a selective pulmonary vasodilator for treatment of PPHN. We describe a case of PPHN in which neither inhaled NO nor ECMO was effective in reversing pulmonary hypertension. The clinical course of the patient suggested a potential role of NO inhalation in predicting the outcome of ECMO treatment for PPHN.

Angiotensin II stimulates production of nitric oxide in guinea pig airways via AT1 receptor activation

Angiotensin II (Ang II) and nitric oxide (NO) regulate a variety of physiological functions. In this study, we suggest that inhaled Ang II produces an initial bronchodilation apparently by stimulating NO production via AT1 receptors. Also, we demonstrate that following the initial bronchodilation, Ang II causes bronchoconstriction in the guinea pig, also via AT1 receptors. Both of the findings are important for our understanding of airway functions induced by Ang II.

Plasma adrenaline modulates alpha 1-adrenoceptor mediated pressor responses and the baroreflex control in patients with borderline hypertension

Plasma level of adrenaline has been reported to be elevated in borderline hypertension. However, its role in developing and maintaining hypertension is still not completely understood. This study aimed to estimate the role of plasma adrenaline in developing hypertension. Ten patients with borderline hypertension (BHT) and 10 age-matched normotensive subjects were included. We infused at least three graded doses of phenylephrine, an alpha-adrenoceptor agonist, into the antecubital vein of subjects lying quietly in a supine position. Mean blood pressure was measured continuously through the right radial artery. Cardiac output was measured by the thermodilution method before and after the administration of each dose of phenylephrine infusion. We obtained dose-response curves for mean blood pressure and total peripheral resistance to phenylephrine. Baroreflex sensitivity was calculated by plotting the longest R-R intervals against the elevated peak mean blood pressure after the infusion of each dose of phenylephrine. Plasma noradrenaline and adrenaline concentrations at rest were measured by high performance liquid chromatography coupled with trihydroxyindole fluorimetric detection. The plasma adrenaline level at rest was higher in patients with BHT than in normotensive subjects. With graded infusion of phenylephrine, both the pressor responses and the changes in total peripheral resistance were greater in patients with BHT than in normotensive subjects. The plasma adrenaline level was positively correlated with the slope of dose response curves for the increments of mean blood pressure to phenylephrine (r = 0.60, p < 0.01). Baroreflex sensitivity was reduced in patients with BHT as compared with normotensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Micelle/water partition properties of phenols determined by liquid chromatographic method. Proposal for versatile measure of hydrophobicity

Partition properties have been determined for 28 monosubstituted phenols in the sodium dodecylsulfate (SDS)/water system by micellar liquid chromatography (MLC), offering a useful and versatile method to estimate the hydrophobicity of compounds. The enthalpy and entropy terms of partition have also been determined from variable temperature experiments on MLC and are interpreted by such factors as molecular size and hydrogen-bond ability of the solute. The pi constants (pi, pi H and pi S) are determined from the experimental partition properties and applied to quantitative structure-activity relationships (QSAR) analysis, and their versatility supported.

Transient adenosine infusion before ischemia and reperfusion protects against metabolic damage in pig hearts

We investigated whether transient adenosine (Ado) infusion before ischemia had the same effect on myocardial metabolism and function as ischemic preconditioning (IP). The control (C) group underwent 15 min of coronary artery occlusion followed by 120 min of reperfusion. The Ado group received a 15-min infusion of Ado (200 micrograms.kg-1.min-1) into the left atrium starting 20 min before ischemia. IP was elicited by two cycles of 5-min ischemia and 5-min reperfusion. In the area at risk, tissue levels of ATP, creatine phosphate (CP), and intracellular pH (pHi) were serially measured by 31P-nuclear magnetic resonance spectroscopy in 10 pigs from each group, and percent segment shortening (%SS) was measured in 7 pigs from each group. ATP and pHi were preserved after 15 min of ischemia in both Ado and IP groups [ATP = 64 +/- 7, 76 +/- 6, and 74 +/- 9% of baseline; pHi = 6.35 +/- 0.19, 6.54 +/- 0.11, and 6.64 +/- 0.11 in C, Ado, and IP groups, respectively (P < 0.05, Ado and IP vs. C)]. During reperfusion, ATP was restored progressively in both groups [71 +/- 7, 90 +/- 8, and 91 +/- 9% of baseline at 120 min of reperfusion in C, Ado, and IP groups, respectively (P < 0.05, Ado and IP vs. C)]. However, in contrast to the IP group, CP was not preserved during 15-min ischemia nor did it show persistent overshoot during reperfusion in the Ado group. There were no significant differences in %SS during ischemia and reperfusion among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Targeted disruption of the NF-IL6 gene discloses its essential role in bacteria killing and tumor cytotoxicity by macrophages

To investigate the role of NF-IL6 in vivo, we have generated NF-IL6 (-/-) mice by gene targeting. NF-IL6 (-/-) mice were highly susceptible to infection by Listeria monocytogenes. Electron microscopic observation revealed the escape of a larger number of pathogens from the phagosome to the cytoplasm in activated macrophages from NF-IL6 (-/-) mice. Furthermore, the tumor cytotoxicity of macrophages from NF-IL6 (-/-) mice was severely impaired. However, cytokines involved in macrophage activation, such as TNF and IFN gamma, were induced normally in NF-IL6 (-/-) mice. Nitric oxide (NO) formation was induced to a similar extent in macrophages from both wild-type and NF-IL6 (-/-) mice. These results demonstrate the crucial role of NF-IL6 in macrophage bactericidal and tumoricidal activities as well as the existence of a NO-independent mechanism of these activities. We also demonstrate that NF-IL6 is essential for the induction of G-CSF in macrophages and fibroblasts.

Human luteal cells express leukocyte functional antigen (LFA)-3

Leukocyte functional antigen-3 (LFA-3)/cluster of differentiation-58 (CD-58) antigen is known as a ligand for CD-2 antigen, which is a specific surface marker of T-lymphocytes. To investigate the involvement of T-lymphocytes on corpus luteum (CL) function, the expression of LFA-3 in human CL was examined by the indirect immunofluorescence method with frozen sections. LFA-3 was not detected on the granulosa cells of primordial, primary, or atretic follicles, but was weakly expressed on the granulosa cells of growing and preovulatory follicles. After ovulation, LFA-3 was clearly expressed on large luteal cells of the CL in any stage of the luteal phase, and the highest expression was observed in the midluteal phase. Antigen expression was also observed in the large luteal cells in CL of pregnancy. Human granulosa cells were isolated from the patients who had undergone in vitro fertilization treatment and were cultured in vitro with or without hCG (1 IU/mL), tumor necrosis factor-alpha (TNF alpha; 10 ng/mL), or interleukin-1 alpha (10 ng/mL). By the indirect immunofluorescence method, LFA-3 was detected on granulosa cells after culture for 1 day, although the fluorescence intensity was very weak. LFA-3 was clearly detected on granulosa cells after 7 days of culture, especially on those with TNF alpha. Flow cytometrical analysis with 7-day cultured cells showed that the percent positivity of LFA-3-positive granulosa cells cultured with TNF alpha was significantly higher than that of the controls (without treatment; 66.5 +/- 3.7% vs. 34.3 +/- 4.9%; P < 0.01; n = 7). The percent positivity of cells cultured with interleukin-1 alpha was slightly higher (51.5 +/- 4.5%; P < 0.1) than that of the controls, whereas treatment with hCG caused no significant difference (46.6 +/- 4.7%) from the controls. These findings indicate that LFA-3 is a differentiation antigen of human granulosa cells. They also suggest that large luteal cells can interact, through LFA-3 molecules, with the CD-2 antigen-positive T-lymphocytes invading the CL after ovulation, and that the expression of LFA-3 is under the control of some cytokines, including TNF alpha.

Antithrombotic effect of ticlopidine on occlusive thrombi of small coronary arteries in (NZWxBXSB)F1 male mice with myocardial infarction and systemic lupus erythematosus

We examined the antithrombotic effect of ticlopidine on occlusive thrombi of small coronary arteries in (NZWxBXSB)F1 [(WxB)F1] male mice with myocardial infarction (MI) and systemic lupus erythematosus (SLE). Ticlopidine (3 and 10 mg/kg) was given to the mice as an additive to a standard laboratory diet from the time the mice were aged 16-24 weeks. The higher dose of ticlopidine significantly increased survival rate of the mice. In mice that received 10 mg/kg ticlopidine, the incidence of MI, the percentage of MI area (%MI), and the incidence and number of small coronary arteries with significant stenosis were significantly lower than in controls. The stenosed lesions were divided into occlusive thrombi related to acute MI and intimal thickening related to old MI. No mice had evidence of significant stenosis or thrombosis in the extramyocardial coronary arteries. Glomerulonephritis, blood urea nitrogen (BUN), and circulating immune complexes were not significantly different among the three groups. A high dose of ticlopidine prevented small coronary artery disease and MI and increased the survival of (WxB)F1 male mice, suggesting that this agent has an antithrombotic effect on occlusive thrombi of the small coronary arteries in such mice.

The macrolide antibacterial roxithromycin reduces bronchial hyperresponsiveness and superoxide anion production by polymorphonuclear leukocytes in patients with asthma

We investigated the effects of a macrolide antibacterial, roxithromycin, on the generation of free radicals by peripheral polymorphonuclear leukocytes (PMNs) and on the severity of bronchial hyperresponsiveness. Ten asthmatic patients were treated for 3 months with roxithromycin, 150 mg orally once daily; such treatment significantly reduced the production of superoxide anion by PMNs (p = 0.0029) and reduced the bronchial hyperreactivity (p = 0.0016), as compared with results in healthy controls. Most of the patients required at least 2 months of treatment with roxithromycin for clinical improvement. We conclude that long-term, low-dose administration of roxithromycin may be useful in treatment of patients with bronchial asthma.

Postoperative flow characteristics of left internal thoracic artery grafts

Twenty patients whose left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery (LAD) underwent postoperative coronary angiography and Doppler ultrasound velocimetry. During angiography, the diameter of the LITA conduit was measured at three points: proximal, mid, and distal. The degree of left anterior descending artery stenosis proximal to the anastomotic site was evaluated by densitometry. The LITA flow velocity pattern was obtained at the three points to calculate the total, systolic, and diastolic flow volume. There were significant differences in the total LITA flow among the three points (proximal, 36.0 +/- 17.2 mL/min; mid, 29.9 +/- 15.2 mL/min; distal, 27.2 +/- 14.0 mL/min; p < 0.001 between the proximal and the mid or distal portions). The degree of left anterior descending artery stenosis affected the distal LITA flow and diameter (r = 0.823 and 0.811, respectively). There were significant differences in the systolic LITA flow among the three points (proximal, 13.2 +/- 6.5 mL/min; mid, 8.1 +/- 4.7 mL/min; distal, 5.6 +/- 3.4 mL/min; p < 0.001 between the proximal and the mid or distal portions). However, there was no statistically significant difference in the diastolic LITA flow among the three points (proximal, 22.9 +/- 11.0 mL/min; mid, 21.7 +/- 10.8 mL/min; distal, 21.6 +/- 10.8 mL/min). We conclude that a lower degree of LAD stenosis significantly reduces the LITA flow, inducing the string phenomenon. Additionally, during the diastolic phase, the LITA graft transports the blood primarily to the coronary artery but not to the side branches. Therefore, the steal phenomenon might not apply in the setting of an LITA graft.

Molecular cloning and characterization of S-adenosyl-L-methionine:scoulerine-9-O-methyltransferase from cultured cells of Coptis japonica

S-Adenosyl-L-methionine:scoulerine-9-O-methyltransferase (SMT) catalyzes the transfer of the S-methyl group of S-adenosyl-L-methionine to the 9-hydroxyl group of scoulerine during the biosynthesis of berberine. We have isolated functionally active cDNA clones (pCJSMTs) from a cDNA library prepared from cultured cells of Coptis japonica. The longest cDNA insert (pCJSMT1) had an open reading frame that encoded 351 amino acids, but the calculated molecular mass (38,364 Da) of the deduced product was slightly lower than the experimentally determined molecular mass of purified SMT. Rapid amplification of the 5' end of the cDNA indicated that the full-length cDNA of SMT consisted of 1,458 nucleotides that encoded 381 amino acids. When the full-length cDNA was expressed in E. coli, the molecular mass of the expressed SMT was greater than that of native SMT in Coptis cells. This result suggests that SMT might be produced in a pre-mature form and processed post-translationally. SMT was also found to exhibit sequence homology to other O-methyltransferases from plants and N-terminal region of the SMT polypeptide appeared to be necessary for enzymatic activity.

Human pulmonary vascular and venous compliances are reduced before and during left-sided heart failure

Human pulmonary vascular and venous compliances were measured in 41 patients with or without left-sided heart failure. Two methods were used. Method 1 was based on analysis of pulmonary capillary wedge (PCW) pressure tracings according to Cv,PCW = (SF/100)(0.075PCW + 0.90)SV/[(v - d)PCW + 1], where Cv,PCW is compliance of pulmonary venous system, SF is systolic fraction of pulmonary venous flow [related to pulmonary capillary wedge pressure (PCW) as SF = 82 - 2.01PCW], (v - d)PCW is pulse pressure in PCW position, and SV is stroke volume. The (0.075PCW + 0.90) term equals k", i.e., systolic run-off ratio. Method 2 was used to measure to pulmonary vascular volume-pressure (V-P) relationship and pulmonary vascular compliance (Cvasc) and is based on measurement of pulmonary blood volume (PBV) and its increase with passive elevation of the legs to calculate Cvasc. Assuming the proportion of blood entering pulmonary venous system (in increase of PBV) during passive leg elevation to be 0.8, pulmonary venous compliance (Cv,PBV) was calculated as Cv,PBV = 0.8Cvasc. Cv,PCW correlated fairly closely with Cv,PBV (r = 0.81, coefficient of variation = 31%). This fair agreement between two independent methods suggests strongly that both methods may be valid, although other interpretations are possible. Cv,PCW, Cvasc, and Cv,PBV decreased going from New York Heart Association class I to classes II and III. When PBV was plotted vs. PCW, average V-P line for class II patients was flatter and shifted downward to the right compared with that for class I. This suggests pulmonary vasoconstriction as well as other factors. Average V-P line for class III patients is flatter but not displaced compared with that for class II. Another previously reported series of 50 patients, most of whom had ischemic heart disease, are included in this study.

A novel and useful descriptor for hydrophobicity, partition coefficient micellar-water, and its application to a QSAR study of antiplatelet agents

Herein we describe the introduction and application of a novel and useful descriptor, logarithm of micelle-water partition coefficients (log Pmw), for hydrophobicity of compounds. A QSAR study using log Pmw on antiplatelet activities ex vivo of 2-substituted phenyl and benzimidazolyl-5-methyl-4-(3-pyridyl)imidazoles showed its usefulness. Antiplatelet activities could be rationalized by means of only log Pmw with an excellent correlation (r = 0.772, s = 0.257, F = 11.07 **, n = 18), while use of other descriptors such as CLOGP values and retention factors (k') failed. Pmw values can easily be obtained using a normal HPLC system using a micelle aqueous solution as the mobile phase. HPLC techniques offer the advantage of tolerating lower sample purity, smaller sample size, and being dynamic range, compared with the flask-shaking method for measurement of logarithm of 1-octanol/water partition coefficients (log P), which is widely used in QSAR study. These indicated that log Pmw could be a useful descriptor for hydrophobicity of compounds.

RFLP analysis of chromosomal fragments in genetic mosaic strains of Bombyx mori

Mottled striped (pSm), a genetic mosaic strain for larval body marking of the silkworm, Bombyx mori, contains a small chromosomal fragment generated by breakage near the end of the 2nd chromosome. This fragment carries the striped marking (pS) gene and part of the chorion gene clusters. To determine the structural features of this fragmented chromosome, we studied the organization of the chorion genes on the fragment using restriction fragment length polymorphism (RFLP) analysis. Two of three classes of chorion gene family probes detected RFLPs in the two phenotypes, pSm (p/p/pS), and p (p/p), which had lost the fragment, segregated among the siblings of a mottled striped strain. Although hybridization patterns were basically identical between them, one or two additional bands were always observed associating with the mosaic phenotype (pSm). This suggests that the additional bands correspond to extra copies of chorion genes on the chromosomal fragment, which have a different structure from ones on the intrinsic 2nd chromosomes. Such heterogeneity of chorion genes may have been maintained since the beginning of mosaic induction, due to the absence of recombinational events between the two chromosomes. We are unable to detect any RFLPs by hybridization with the early class of chorion genes, implying that chromosomal breakage might have occurred between the two chorion clusters, Chl-2 and Ch3, which are located approximately 4 cM apart from each other. Based on RFLP analyses for two independent mosaic strains (788 and 872), we postulate a common chromosomal origin with independent breakpoints and construct structural models for the two kinds of chromosomal fragments.

Transition from compensatory hypertrophy to dilated, failing left ventricles in Dahl salt-sensitive rats

To establish an experimental model for studying a specific transitional stage for compensatory hypertrophy to heart failure, we studied the pathophysiology of the left ventricle (LV) in Dahl salt-sensitive (DS) rats fed a high-salt diet. DS rats fed an 8% NaCl diet after the age of 6 wk developed concentric LV hypertrophy at 11 wk, followed by marked LV dilatation at 15-20 wk. During the latter stage, the DS rats showed labored respiration with LV global hypokinesis. All the DS rats died within 1 wk by massive pulmonary congestion. The dissected left ventricles revealed chamber dilatation and a marked increase in mass without myocardial necrosis. In contrast, corresponding Dahl salt-resistant (DR) rats fed the same diet showed neither mortality nor any of these pathological changes. The in vivo LV end-systolic pressure-volume relationship shifted to the right with a less steep slope in the failing DS rats compared with that in age-matched DR rats. Isometric contractions of LV papillary muscles isolated from these DS rats showed reduced tension development in the failing stage, but normal tension development in the hypertrophied stage. In conclusion, the DS rat fed a high-salt diet is a useful model showing rapidly developing congestive heart failure, in which the transition from compensatory hypertrophy to decompensatory dilatation of LV is easily and consistently manifested.

Solution structure of human insulin-like growth factor II; recognition sites for receptors and binding proteins

The three-dimensional structure of human insulin-like growth factor II was determined at high resolution in aqueous solution by NMR and simulated annealing based calculations. The structure is quite similar to those of insulin and insulin-like growth factor I, which consists of an alpha-helix followed by a turn and a strand in the B-region and two antiparallel alpha-helices in the A-region. However, the regions of Ala1-Glu6, Pro31-Arg40 and Thr62-Glu67 are not well-defined for lack of distance constraints, possibly due to motional flexibility. Based on the resultant structure and the results of structure-activity relationships, we propose the interaction sites of insulin-like growth factor II with the type 2 insulin-like growth factor receptor and the insulin-like growth factor binding proteins. These sites partially overlap with each other at the opposite side of the putative binding surface to the insulin receptor and the type 1 insulin-like growth factor receptor. We also discuss the interaction modes of insulin-like growth factor II with the insulin receptor and the type 1 insulin-like growth factor receptor.

Atrioventricular nodal physiology after slow pathway ablation

The AV nodal physiology before and 1 week after "slow pathway potential" guided catheter ablation was examined in 32 patients with AV nodal reentrant tachycardia. A mean of 4.9 applications of radiofrequency energy eliminated AV nodal reentrant tachycardia in all patients. There were no significant differences in sinus cycle length (815 +/- 159 msec vs 813 +/- 162 msec; P = NS) and fast pathway conduction properties before and 1 week after ablation. Slow pathway conduction was completely eliminated in 10 (31%) (group I) of 32 patients after ablation. In the remaining 22 patients residual slow pathway conduction associated with one AV node echo was observed. In 15 patients (47%) (group II), the effective refractory period of the slow pathway showed a change of < 30 msec (265 +/- 51 vs 266 +/- 51 msec; P = NS), and in 7 patients (22%) (group III), a prolongation of more than 80 msec (247 +/- 56 vs 340 +/- 42 msec; P = 0.0001) before and 1 week after ablation. Minimal and maximal A2-H2 interval over the slow pathway in group II was not significantly changed (Min A2-H2: 241 +/- 37 vs 247 +/- 40 msec; P = NS, Max A2-H2: 346 +/- 79 vs 350 +/- 60 msec; P = NS), while a significant prolongation was measured in group III (Min A2-H2: 261 +/- 53 vs 373 +/- 107 msec; P < 0.01, Max A2-H2: 359 +/- 41 vs 427 +/- 63 msec; P < 0.05) before and after ablation.(ABSTRACT TRUNCATED AT 250 WORDS)