Effects of metal ions on physicochemical properties and redox reactivity of phenolates and phenoxyl radicals: mechanistic insight into hydrogen atom abstraction by phenoxyl radical-metal complexes

Phenolate and phenoxyl radical complexes of a series of alkaline earth metal ions as well as monovalent cations such as Na+ and K+ have been prepared by using 2,4-di-tert-butyl-6-(1,4,7,10-tetraoxa-13-aza-cyclopentadec-13-ylmethyl)phenol (L1H) and 2,4-di-tert-butyl-6-(1,4,7,10,13-pentaoxa-16-aza-cyclooctadec-16-ylmethyl)phenol (L2H) to examine the effects of the cations on the structure, physicochemical properties and redox reactivity of the phenolate and phenoxyl radical complexes. Crystal structures of the Mg2+- and Ca2+-complexes of L1- as well as the Ca2+- and Sr2+-complexes of L2- were determined by X-ray crystallographic analysis, showing that the crown ether rings in the Ca2+-complexes are significantly distorted from planarity, whereas those in the Mg2+- and Sr2+-complexes are fairly flat. The spectral features (UV-vis) as well as the redox potentials of the phenolate complexes are also influenced by the metal ions, depending on the Lewis acidity of the metal ions. The phenoxyl radical complexes are successfully generated in situ by the oxidation of the phenolate complexes with (NH4)(2)[Ce4+(NO3)6] (CAN). They exhibited strong absorption bands around 400 nm together with a broad one around 600-900 nm, the latter of which is also affected by the metal ions. The phenoxyl radical-metal complexes are characterized by resonance Raman, ESI-MS, and ESR spectra, and the metal ion effects on those spectroscopic features are also discussed. Stability and reactivity of the phenoxyl radical-metal complexes are significantly different, depending on the type of metal ions. The disproportionation of the phenoxyl radicals is significantly retarded by the electronic repulsion between the metal cation and a generated organic cation (Ln+), leading to stabilization of the radicals. On the other hand, divalent cations decelerate the rate of hydrogen atom abstraction from 10-methyl-9,10-dihydroacridine (AcrH2) and its 9-substituted derivatives (AcrHR) by the phenoxyl radicals. On the basis of primary kinetic deuterium isotope effects and energetic consideration of the electron-transfer step from AcrH2 to the phenoxyl radical-metal complexes, we propose that the hydrogen atom abstraction by the phenoxyl radical-alkaline earth metal complexes proceeds via electron transfer followed by proton transfer.

The biocompatibility and osteoconductive activity of a novel hydroxyapatite/collagen composite biomaterial, and its function as a carrier of rhBMP-2

A hydroxyapatite/type I collagen (HAp/Col) composite, in which the hydroxyapatite nanocrystals align along the collagen molecules, has been prepared. The biocompatibility, osteoconductive activity, and efficacy as a carrier of recombinant human bone morphogenetic proteins (rhBMPs) of this novel biomaterial were examined. The composite material was implanted in the backs of Wistar rats, and specimens were collected for histological observations until week 24. In a second experiment, other samples of the composite material (5 x 5 x 10 mm3) were drilled and immersed in a solution of rhBMP-2 (0, 200, 400 microg/mL), and subsequently grafted in radii and ulnae in beagle dogs. As a control, three unfilled holes were left in one radius and ulna. X-ray images were prepared, and specimens collected for histological observation at weeks 8 and 12. Histological findings of the composites grafted in rats showed that the surface of the material was eroded as a result of macrophage infiltration. X-ray images and histological findings for the composites implanted in dogs support the idea that HAp/ Col has a high osteoconductive activity and is able to induce bone-remodeling units. In cases where the implants are grafted at weight bearing sites, treatment with rhBMP-2 at a dose of 400 microg/mL may be useful to shorten the time needed until bone union has occurred.

Evaluation of hepatocellular carcinoma after treatment with transcatheter arterial chemoembolization: comparison of Lipiodol-CT, power Doppler sonography, and dynamic MRI

BACKGROUND

The purpose of this study was to compare the ability of Lipiodol-computed tomography (CT), power Doppler (PD) sonography, and dynamic magnetic resonance imaging (MRI) in evaluating the therapeutic effect of transcatheter arterial chemoembolization (TACE) on hepatocellular carcinoma (HCC).

METHODS

TACE was performed by injecting an emulsion consisting of Lipiodol and a chemotherapeutic drug, followed by gelatin sponge particles, into 54 patients with 84 HCC lesions. Five to 7 days later, Lipiodol-CT, PD sonography, and dynamic MRI were performed. Findings from the three modalities were correlated with relapse within 1 year after TACE.

RESULTS

All lesions with blood flow on PD sonography or intratumoral enhancement on dynamic MRI relapsed regardless of the findings with Lipiodol-CT. None of the negatively enhanced lesions on dynamic MRI relapsed regardless of the Lipiodol-CT findings. However, the readers could not evaluate the contrast uptake in 14 lesions that were already hyperintense on the precontrast images. These cases were considered unsuitable for qualitative assessment and reduced the applicability of MRI to 83% of the examined lesions (70 of 84). Although PD sonography perfectly predicted relapse in superficial (0-5 cm from abdominal surface) lesions of the right hepatic lobe, blood flow in deep (>5 cm) or left lobe lesions was undetectable regardless of the occurrence of relapse. As a result, Lipiodol-CT displayed 76.0% sensitivity, 67.6% specificity, and 72.6% accuracy. The sensitivity, specificity, and accuracy of PD sonography were 34.0%, 100%, and 60.7%, respectively. In the 70 lesions in which evaluation was possible, dynamic MRI achieved 100% sensitivity, 100% specificity, and 100% accuracy.

CONCLUSION

Of the three modalities, dynamic MRI was the best for evaluating the efficacy of TACE in the treatment of HCC. We also found that superficial lesions of the right lobe are good candidates for PD sonography. However, high signals on precontrast MR images, motion artifacts, and ultrasonic attenuation remain key limitations.

Functional imaging of the brain in sedated newborn infants using near infrared topography during passive knee movement

Near infrared topography was used for functional imaging of the sensorimotor cortex of newborn infants during passive knee movement under sedated sleep. Contralateral knee movement caused a marked increase in oxyhemoglobin and total hemoglobin from the baseline values at almost all locations in the primary sensorimotor area of all neonates and a decrease in local deoxyhemoglobin in six of seven neonates. During ipsilateral knee movement, oxyhemoglobin and total hemoglobin showed slighter changes at a few locations, equal to 30% (mean) and 29% (mean) of the changes that occurred with contralateral stimulation, respectively. The mean times corresponding to maximal changes were 11.9 s for oxyhemoglobin and 19.1 s for deoxyhemoglobin, demonstrating that oxyhemoglobin has a much faster response than does deoxyhemoglobin.

Differences in transcutaneous bilirubin readings in Japanese term infants according to feeding method

BACKGROUND

Controversy has existed for many years over whether infant feeding methods are related to serum bilirubin concentrations during the first few days of life. Differences in initial jaundice patterns according to the feeding method until 72 h after birth have not been elucidated hitherto. The difference may become clear in Japanese neonates because jaundice shows a much higher peak bilirubin concentration and a later peak in Japanese neonates than in Caucasian neonates.

METHODS

In the present study, we investigated variations in the transcutaneous bilirubin reading (TcB) obtained within 72 h after birth among 177 breast-fed and 494 formula-fed healthy Japanese term neonates.

RESULTS

There was no difference between TcB in formula-fed and breast-fed infants until the first 30 h, after which time the rate of increase in TcB was lower in formula-fed infants. Among breast-fed neonates, a good linear regression between time after birth and TcB was maintained. Similarly, weight losses in breast-fed infants at 24-48 h and 48-72 h after birth were greater than those in formula-fed infants.

CONCLUSIONS

The jaundice pattern in Japanese neonates from 30 to 72 h after birth according to the feeding method was different from that in Caucasian neonates.

Concentration of progenitor cells collected from bone marrow fluid using a continuous flow cell separator

In ABO major incompatibility on bone marrow transplantation (BMT), red cells must be removed from collected marrow fluid to prevent hemolysis. We report the concentration of progenitor cells collected using a continuous flow cell separator (Cobe Spectra). The average volume of concentrated bone marrow was 132 +/- 47 ml and that of red cells included was 5.1 +/- 2.4 ml. The red cell removal rate was 97.6%. The recovery rate was 40.6% for total nuclear cells, 77.9% for mononuclear cells, 100% for CD34+ cells, and 93.9% for colony forming unit granulocyte-macrophage. Eighteen patients undergoing allogeneic BMT showed no signs of fever or hemolysis during concentrated marrow fluid transfusion. The recovery rate of progenitor cells was high, indicating sufficient recovery of hemopoiesis. This technique is applicable in ABO-incompatible BMT and in frozen-storage stem cells.

A study of induction of nerve regeneration using bioabsorbable tubes

A silicone tube (S-tube) was packed with CPLA (copolymer of poly-L-lactide) fibers (S-tube+CPLA) or collagen fibers (S-tube+fiber). Two types of tube were prepared from a collagen sheet (Col-tube) and a bioabsorbable atelocollagen membrane for guided tissue regeneration (GTR-tube). They were packed with collagen fibers or films (Col-tube+fiber, GTR-tube+fiber and GTR-tube+film). Bridge grafting (15 mm in length) was performed with these tubes in a rat sciatic nerve model. Specimens were harvested after 8 weeks. Minifascicles were formed in the open space between the CPLA fibers in the S-tube+CPLA group. Regenerated axons were also formed in the degenerated collagen fibers in the S-tube+Col group. Immunocytochemistry evaluation revealed that Schwann cells invaded the space in the absorbing collagen fibers. Histologic analysis of the regenerated axons in the groups with Col-tubes or GTR-tubes revealed that both the Col-tube and the GTR-tube packed with collagen fibers were effective in providing a scaffold for regenerating nerve tissue.

Aquaporin subtypes in rat cerebral microvessels

We investigated the expression of aquaporin (AQP) subtypes in the rat cerebral microvessels by reverse transcription-polymerase chain reaction, immunoblotting and immunohistochemistry. mRNA for AQP4, but not for AQP1, 2, 3 or 5, was detected in the microvessels. Immunoblot analysis showed that AQP4 protein was detected as a 30 kDa band with higher molecular weight bands. Immunohistochemical staining showed that AQP4 was located on cell surface of the cerebral microvessels. These results suggest that AQP4 in the cerebral microvessels is involved in the regulation of water transport between blood and brain.

Usefulness of redox tolerance test in evaluating fatty liver

BACKGROUND/AIMS

In living-related liver transplantation, fatty liver should be exactly detected in the healthy donor with noninvasive measurement before the surgery. The study aimed to investigate the usefulness of redox tolerance test in diagnosing fatty liver.

METHODOLOGY

The subjects were 32 patients who underwent an abdominal surgery. They did not show any abnormal values in biochemical evaluations, nor had they diabetes. Under informed consent, liver specimens were obtained intraoperatively, and the subjects were divided into three groups according to the degree of hepatic fatty deposit: group A has fatty deposits at less than 10% of hepatocytes (n = 12), group B showed the deposits at 10-30% (n = 10), group C has the deposits of more than 30% (n = 10). Before the surgery, redox tolerance test was performed as follows; arterial blood samples were obtained successively at 75 g oral glucose load over a 120-min period, and the arterial ketone body ratio and blood glucose level were determined. The ratio of increased arterial ketone body ratio (AKBR) to increased blood glucose (BG) level (100 x delta AKBR/delta BG) was calculated as redox tolerance index.

RESULTS

After fasting state, arterial ketone body ratio and blood glucose level did not differ among the three groups. However, the values of redox tolerance index in groups B (0.73 +/- 0.08) and C (0.46 +/- 0.04) were significantly lower than those in group A (1.85 +/- 0.31).

CONCLUSIONS

The redox tolerance test was exceedingly sensitive indicator for objectively diagnosing the fatty liver.

Nitric oxide regulates smooth-muscle-specific myosin heavy chain gene expression at the transcriptional level-possible role of SRF and YY1 through CArG element

Nitric oxide (NO) plays an important role in vascular regulation through its vasodilatory, antiatherogenic, and antithrombotic properties. NO inhibits platelet adhesion and aggregation and modulates smooth muscle cell (SMC) proliferation and migration. In animals with experimentally induced vascular injury, ec-NOS gene transfection not only restored NO production to normal levels but also increased vascular reactivity of the injured vessels. However, it is unclear whether NO regulates smooth-muscle-specific gene expression. We report here that addition of PDGF-BB to vascular smooth muscle cells suppressed SM-MHC expression but treatment with the NO donors FK409 and SNAP restored SM-MHC mRNA/protein expression. In vitro transfection and subsequent CAT assays demonstrated that exogenous NO can restore PDGF-BB-induced suppression of SM-MHC promoter activity. Promoter deletion analysis revealed that a CArG-3 box located at -1276 bp in the SM-MHC promoter was important for NO-dependent promoter regulation and as well as high level promoter activity. Gel mobility shift assays showed that CArG-3 contained the SRF binding site and a binding site for YY1, a nuclear factor which acts as a negative regulator on muscle-specific promoters. Interestingly, NO donor FK409 reduced YY1 binding to the CArG-3 element but increased SRF binding, suggesting that these two factors bind competitively to the overlapping sites. We also found that mutation to the YY1 binding site in the CArG-3 element resulted in a loss of PDGF-BB-induced suppression of the SM-MHC promoter activity. These findings indicate that NO regulates SM-MHC gene expression at the transcriptional level at least partially through the regulation of transcription factor binding activities on the CArG element. Thus we propose that NO plays a positive role in maintaining the differentiated state of VSMCs.

Genetic background in patients with acute myocardial infarction

The renin-angiotensin system is believed to play important roles in the development of acute myocardial infarction, and gene polymorphisms may also be involved. To investigate the genetic background in patients with acute myocardial infarction, we performed a case control study in a Japanese population. The study included 150 patients with acute myocardial infarction and 150 healthy, age- and sex-matched controls. We examined polymorphisms of angiotensin II type 1 receptor (1 166 A / C), type 2 receptor (3123 C / A), and bradykinin B2 receptor (-58 T / C) in these subjects. The allelic frequencies of angiotensin II type I receptor C and angiotensin II type 2 receptor A were significantly higher in the acute myocardial infarction subjects than in the control subjects, and this tendency was more significant in the younger patients. The combined ratios of angiotensin II type 1 receptor C and type 2 receptor A alleles in patients under 64 years old were significantly higher than in their older counterparts. However the total numbers of conventional coronary risk factors (hypertension, hypercholesterolemia, diabetes mellitus, and smoking) in individual subjects were not significantly different between younger and older patients. These polymorphisms were found to be involved in the development of acute myocardial infarction, particularly in the younger patients, and it was concluded that the incidence of acute myocardial infarction might be reduced by management from the genotypes.

A method for detecting myocardial abnormality by using a current-ratio map calculated from an exercise-induced magnetocardiogram

A method for making a current-ratio map to determine the ischaemic area of angina pectoris (AP) patients has been developed. This method uses a current-arrow map calculated using a ORS wave from 64-channel magnetocardiogram (MCG) signals. The current-ratio map can be calculated from the ratio of an exercise-induced current vector to an at-rest current vector. The MCG signals of eight patients with angina pectoris (AP) (six patients with effort AP and two patients with variant AP) and four healthy volunteers were measured before and after a two-step exercise test. The current-ratio maps of the six patients with effort AP showed three distinct patterns: a left-circumflex-artery (LCX) pattern; a right-coronary-artery (RCA) pattern; and a left-anterior-descending (LAD) pattern. The maximum current ratios of these three patterns differed from those of normal patterns. The patterns of two patients with variant AP were similar to normal patterns. Furthermore, a comparison of the current-ratio map before and after percutaneous-transluminal-coronary-angioplasty (PTCA) treatment indicated that the cardiac ischaemia was reduced in all patients. An appropriate criterion to diagnose abnormality in a patient with an ischaemic myocardial area seems to be a maximum current ratio exceeding 0.4 to 0.5. Based on these preliminary results, it is believed that the location of an ischaemic area (the coronary artery part) can be estimated by using the ischaemic current-ratio map pattern.

A method for detecting myocardial abnormality by using a total current-vector calculated from ST-segment deviation of a magnetocardiogram signal

A simple method to determine the state of ischaemia or fibrosis of myocardial cells has been developed. This method uses the ST wave of 64-channel magnetocardiogram (MCG) signals to calculate three parameters from the current-arrow map of the normal component signal of the MCG. One parameter is a total current vector that is obtained through summation of all current arrows. Another is a variance current vector calculated from the differential vector of two total current vectors at different times. The third is a flatness factor between the magnitude of the total current vector and the variance current vector. The three parameters are independent of the distance between the heart and the gradiometers. We measured the MCG signals of 29 healthy subjects, twenty patients with coronary artery disease (ten with previous myocardial infarction (MI) and ten with angina pectoris (AP)), and eight patients with cardiomyopathy (four with hypertrophic cardiomyopathy (HCM), three with dilated cardiomyopathy (DCM), and one with restrictive cardiomyopathy (RCM)). With our method, none of the healthy subjects tested positive for myocardial abnormalities, while 80% of the MI patients, 50% of the AP patients, and 100% of the cardiomyopathy patients tested positive. Although further testing is needed, we feel this simple technique enables easy diagnosis of myocardial damage.

Successful treatment of disseminated Fusarium infection in an infant with leukemia

Disseminated Fusarium infection in an immunocompromised host is intractable and results in high mortality. We provide the first full case report on successful treatment of a disseminated Fusarium infection in an infant. The 6-month-old infant, whose family raised livestock, had infantile leukemia. During the neutropenic period after intensive chemotherapy, vomiting, diarrhea, fever, subcutaneous nodes, and coughing appeared. Pneumonia was diagnosed, and Fusarium moniliforme was isolated from blood culture. A central venous catheter was removed. Granulocyte colony-stimulating factor (G-CSF) and amphotericin B (AMPH-B) (total dose, 65 mg/kg) were administered continuously for 8 weeks. The infection was resolved according to improvement of clinical and laboratory findings, and intensive chemotherapy was restarted for the leukemia. Cord blood stem cell transplantation from an unrelated donor was performed. The Fusarium infection did not recur, but after transplantation, leukemia relapsed. Treatment of neutrophils using G-CSF, AMPH-B, and local treatment induced resolution of the disseminated Fusarium infection in this immunocompromised host with malignancy. We suggest caution for patients living in an environment conducive to the development of Fusarium infection because of the particular risk of infection.

Signaling of transforming growth factor-beta family members through Smad proteins

Smads are pivotal intracellular nuclear effectors of transforming growth factor-beta (TGF-beta) family members. Ligand-induced activation of TGF-beta family receptors with intrinsic serine/threonine kinase activity trigger phosphorylation of receptor-regulated Smads (R-Smads), whereas Smad2 and Smad3 are phosphorylated by TGF-beta, and activin type I receptors, Smad1, Smad5 and Smad8, act downstream of BMP type I receptors. Activated R-Smads form heteromeric complexes with common-partner Smads (Co-Smads), e.g. Smad4, which translocate efficiently to the nucleus, where they regulate, in co-operation with other transcription factors, coactivators and corepressors, the transcription of target genes. Inhibitory Smads act in most cases in an opposite manner from R- and Co-Smads. Like other components in the TGF-beta family signaling cascade, Smad activity is intricately regulated. The multifunctional and context dependency of TGF-beta family responses are reflected in the function of Smads as signal integrators. Certain Smads are somatically mutated at high frequency in particular types of human cancers. Gene ablation of Smads in the mouse has revealed their critical roles during embryonic development. Here we review the latest advances in our understanding of the Smad mechanism of action and their in vivo functions.

Synthetic modification of prostaglandin f(2alpha) indicates different structural determinants for binding to the prostaglandin F receptor versus the prostaglandin transporter

Several principles governing the binding of E series prostaglandins to EP receptors have emerged in recent years. The C-1 carboxyl group binds electrostatically to a conserved arginine residue in the seventh transmembrane segment of the receptor. Prostaglandin E analogs involving bioisosteric replacements of the carboxyl group, such as acylsulfonamide, are also active. In addition, structurally similar esters may also exhibit similar affinity, presumably by virtue of hydrogen bonding. Other regions of the substrate molecule appear to bind to other domains of EP receptors, either via hydrophobic interactions or by hydrogen bonding. Less information is available about the structural requirements for substrate binding to FP receptors. Prostanoids also bind to the prostaglandin transporter PGT. In this case, a conserved C-1 carboxyl group is critically important, since C-1 esters exhibit little affinity. Here we examined the binding of chemically diverse PGF(2alpha) structural analogs to the FP receptor and compared these with binding by the PG transporter. PGT recognized a wide range of anionic substituents. In contrast, the carboxylic acid group was essential for optimal binding to the FP receptor, since replacement by larger moieties with a similar pK(a), such as acylsulfonamide and tetrazole, substantially decreased binding affinity. Interestingly, insertion of cyclic substituents in the omega chain increased binding to the FP receptor but reduced affinity for PGT, and substitution for the 15-hydroxyl group produced only a modest reduction in FP receptor binding, but eliminated binding by PGT. Because extracellular PGF(2alpha) may compete for binding between FP receptors and PGT, these findings have implications for designing PGF(2alpha) analogs for treating disease states.

Endovascular Treatment with GDC for Severe Acute SAH: Comparison with Early Direct Surgery

SUMMARY

The purpose of this study was to evaluate the effect of endovascular treatment with Guglielmi detachable coils (GDC) on the outcome of severe subarachnoid hemorrhage (SAH) caused by acute rupture of a cerebral aneurysm and on the incidence of symptomatic vasospasm. Thirty- five patients with aneurysmal SAH were treated in the acute stage using GDC. Fifteen out of 17 patients in Hunt & Kosnik grades I, II, and III showed good recovery (GR) at discharge, while one was moderately disabled (MD) and one was severely disabled (SD). Among 16 patients in poor neurological condition (GCS was </= 9 on admission), the outcome was GR in 5 cases (31%), MD in 2 (13%), and SD in 9 (56%). These results were better than those for surgically treated patients with the same neurological status. The difference in outcome between endovascular treatment and surgery may have been related to the difference in the insult to the brain caused by each modality. The incidence of symptomatic vasospasm was lower in the GDC group (5.7%) than in the surgical group (12%). In the patients treated with GDC and intrathecal administration of urokinase, subarachnoid clots were cleared more rapidly than in those treated surgically with continuous cisternal irrigation. The accelerated clearance of subarachnoid clots in the GDC group might have helped to prevent delayed vasospasm. The long-term efficacy of GDC embolization in preventing subsequent bleeding has not yet been determined. However, this method seems to be less traumatic for the brain and may be suitable for treatment of patients with severe SAH.

Studies on the interactions between drugs and estrogen: analytical method for prediction system of gynecomastia induced by drugs on the inhibitory metabolism of estradiol using Escherichia coli coexpressing human CYP3A4 with human NADPH-cytochrome P450 reductase

To establish a prediction system for drug-induced gynecomastia in clinical fields, a model reaction system was developed to explain numerically this side effect. The principle is based on the assumption that 50% inhibition concentration (IC(50)) of drugs on the in vitro metabolism of estradiol (E2) to its major product 2-hydroxyestradiol (2-OH-E2) can be regarded as the index for achieving this purpose. By using human cytochrome P450s coexpressed with human NADPH-cytochrome P450 reductase in Escherichia coli as the enzyme, the reaction was examined. Among the nine enzymes (CYP1A1, 1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4) tested, CYP3A4 having a V(max)/K(m) (ml/min/nmol P450) value of 0.32 for production of 2-OH-E2 was shown to be the most suitable enzyme as the reagent. The inhibitory effects of ketoconazole, cyclosporin A, and cimetidine toward the 2-hydroxylation of E2 catalyzed by CYP3A4 were obtained, and their IC(50) values were 7 nM, 64 nM, and 290 microM, respectively. The present results suggest that IC(50) values thus obtained can be substituted as the prediction index for gynecomastia induced by drugs, considering the patients' individual information.

Thrombospondin-1 expression in oral squamous cell carcinomas: correlations with tumor vascularity, clinicopathological features and survival

Thrombospondin-1 (TSP-1) is a 450 kd glycoprotein synthesized and incorporated into the extracellular matrix by numerous cell types and reported to suppress tumor growth and progression by its inhibition of angiogenesis. In order to clarify the biological role of TSP-1 and determine its clinicopathological significance in oral squamous cell carcinomas (SCCs), we identified TSP-1 protein expression in 54 oral SCCs by immunohistochemistry and correlated it with microvessel density (MVD), clinicopathological features and patient's survival. Thirty-two out of 54 carcinomas (59%) were identified as having a low level of TSP-1 expression (TSP-1-L), and 22/54 (41%) carcinomas identified as having a high level of TSP-1 expression (TSP-1-H). The MVD counts (mean+/-S.D.=9.0+/-4.9) in TSP-1-H tumors was significantly lower than that (mean+/-S.D.=12.7+/-4.4) in TSP-1-H tumors (P=0.0065). The level of TSP-1 expression was not correlated with T category and histologic grade, but inversely correlated with the pattern of tumor invasion (P=0.0136) and with lymph nodal status (P=0.0119). Furthermore, Kaplan-Meier analysis showed that the 5-year survival rate of TSP-1-H group was significantly higher than that of TSP-l-L group. Our results suggested that TSP-1 expression exerts an inhibitory effect on tumor vascularity, and that it has value in assessment of aggressiveness and prognosis of oral SCCs.

The transcriptional co-activator P/CAF potentiates TGF-beta/Smad signaling

Smads perform pivotal functions in the intracellular signaling of transforming growth factor-beta (TGF-beta). TGF-beta-mediated activation of TGF-beta type I receptor stimulates the phosphorylation of Smad2 and Smad3 and subsequent heteromeric complex formation with Smad4. The heteromeric Smad complexes translocate into the nucleus where they, in co-operation with co-activators and co-repressors, regulate transcriptional responses. Here we investigated the possible co-activator function of P/CAF in TGF-beta/Smad signaling. P/CAF was found to interact directly with Smad3 in vitro. Moreover, Smad2 and Smad3 interacted with P/CAF upon TGF-beta type I receptor activation in cultured mammalian cells. The interaction involves the MH2 domain of Smad3 and the N-terminal region of P/CAF. P/CAF potentiated the transcriptional activity of heterologous Gal4-Smad2 and Gal4-Smad3 fusion proteins. In addition, P/CAF potentiated the TGF-beta/Smad3-induced transcriptional responses, which could be further enhanced by co-activators p300 and Smad4. P/CAF may, therefore, activate Smad-mediated transcriptional responses independently or in co-operation with p300/CBP. Our results indicate a direct physical and functional interplay between two negative regulators of cell proliferation, Smad3 and P/CAF.

Global spectral-kinetic analysis of room temperature chlorophyll a fluorescence from light-harvesting antenna mutants of barley

This study presents a novel measurement, and simulation, of the time-resolved room temperature chlorophyll a fluorescence emission spectra from leaves of the barley wild-type and chlorophyll-b-deficient chlorina (clo) f2 and f104 mutants. The primary data were collected with a streak-camera-based picosecond-pulsed fluorometer that simultaneously records the spectral distribution and time dependence of the fluorescence decay. A new global spectral-kinetic analysis programme method, termed the double convolution integral (DCI) method, was developed to convolve the exciting laser pulse shape with a multimodal-distributed decay profile function that is again convolved with the spectral emission band amplitude functions. We report several key results obtained by the simultaneous spectral-kinetic acquisition and DCI methods. First, under conditions of dark-level fluorescence, when photosystem II (PS II) photochemistry is at a maximum at room temperature, both the clo f2 and clo f104 mutants exhibit very similar PS II spectral-decay contours as the wild-type (wt), with the main band centred around 685 nm. Second, dark-level fluorescence is strongly influenced beyond 700 nm by broad emission bands from PS I, and its associated antennae proteins, which exhibit much more rapid decay kinetics and strong integrated amplitudes. In particular a 705-720 nm band is present in all three samples, with a 710 nm band predominating in the clo f2 leaves. When the PS II photochemistry becomes inhibited, maximizing the fluorescence yield, both the clo f104 mutant and the wt exhibit lifetime increases for their major distribution modes from the minimal 205-500 ps range to the maximal 1500-2500 ps range for both the 685 nm and 740 nm bands. The clo f2 mutant, however, exhibits several unique spectral-kinetic properties, attributed to its unique PS I antennae and thylakoid structure, indicating changes in both PS II fluorescence reabsorption and PS II to PS I energy transfer pathways compared to the wt and clo f104. Photoprotective energy dissipation mediated by the xanthophyll cycle pigments and the PsbS protein was uninhibited in the clo f104 mutant but, as commonly reported in the literature, significantly inhibited in the clo f2; the inhibited energy dissipation is partly attributed to its thylakoid structure and PS II to PS I energy transfer properties. It is concluded that it is imperative with steady-state fluorometers, especially for in vivo studies of PS II efficiency or photoprotective energy dissipation, to quantify the influence of the PS I spectral emission.

Selective extraction of antenna chlorophylls, carotenoids and quinones from photosystem I reaction center

By the ether treatment of lyophilized PSI pigment-protein complexes, all the carotenoids and the secondary acceptor phylloquinone (A1), and more than 90% of the Chl were removed to yield the PSI complex with 9-11 molecules of Chl per reaction-center unit. The complexes retained the primary electron donor and acceptor (P700 and A0), in addition to three FeS clusters (F(X), F(A) and F(B)), and showed an activity of highly efficient electron transfer when phylloquinone was reconstituted. The methods for the preparation and the characterization of the ether-extracted PSI complexes are reviewed in this article. We also review the studies done with this PSI preparation on (1) the identification of the absorption and fluorescence spectra of P700, (2) the nano- and picosecond reaction of A0 and A1, (3) the energy-gap dependency of the reaction rate between A0 and the artificial quinones reconstituted at the A1 site, (4) the direct excitation of P700 followed by the ultra-fast electron transfer from P700 to A0, and (5) the de- and re-stabilization of the PSI structure by the removal and reconstitution, respectively, of antenna Chl in the presence of certain lipids.

Functional consequences of tumorigenic missense mutations in the amino-terminal domain of Smad4

Smads, the intracellular effectors of transforming growth factor-beta (TGF-beta) family members, are somatically mutated at high frequency in particular types of human cancers. Certain of these mutations affect the Smad amino-terminal domain, which, in the case of Smad3 and Smad4, binds DNA. We investigated the functional consequences of four missense mutations in the Smad4 amino-terminal domain found in human tumors. The mutant proteins were found to have impaired abilities to bind DNA although they were fully capable of forming complexes with Smad3. All four Smad4 mutants showed decreased protein stability compared to wild-type Smad4. Two of the Smad4 mutants (G65V and P130S) were translocated to the nucleus and were capable of transactivating a Smad-dependent promoter in a ligand-dependent manner. In contrast, the L43S and R100T mutants were not translocated efficiently to the nucleus and consequently resulted in severely defective transcriptional responses to TGF-beta. Moreover, we demonstrate here the critical importance of two basic residues in the beta-hairpin loop of Smad3 or Smad4 for DNA binding, consistent with predictions from the Smad3 crystal structure. In addition, our results reveal that in the TGF-beta-induced heteromeric signaling complex, loss of DNA binding of Smad4 can be compensated by Smad3, however, both Smad3 and Smad4 are needed for efficient DNA binding and signaling. In conclusion, mutations in the amino-terminal domain of Smad4, that are found in cancer, show loss of multiple functional properties which may contribute to tumorigenesis.

Anodic oxidation and hydrothermal treatment of titanium results in a surface that causes increased attachment and altered cytoskeletal morphology of rat bone marrow stromal cells in vitro

Previous studies have suggested the usefulness of a new coating method-namely, the forming of a thin hydroxyapatite (HA) layer on commercially pure titanium (cpTi) by anodization and hydrothermal treatment-for use as a dental root implant material. In vivo and in vitro studies confirmed that an HA layer on cpTi (HA/cpTi) implants showed good compatibility with bone tissue, rat bone marrow stromal (RBM) cells, and immune cells. The aim of the present investigation was to further characterize the in vitro early cellular behavior of RBM cells on HA/cpTi implants. Therefore, in this study we performed surface analysis, analysis of cell initial attachment, and analysis of cell morphology and the cytoskeleton. Drops of distilled water or cell culture medium showed smaller contact angles with HA/cpTi than with cpTi. RBM cells were cultured for 30, 60, and 120 min on HA/cpTi and cpTi, and the level of cell adhesion was shown to increase with time on both substrates. However, cell adhesion on HA/cpTi was significantly higher than on cpTi at 60 and 120 min. Especially at 120 min, when compared with cpTi, the cell morphology on the surface of HA/cpTi not only adopted a flattened and spreading form, but also extended filopodium-like processes with irregular edges that were intimately adapted to the surface of the HA microcrystals. The cytoskeleton on HA/cpTi showed well-formed actin filaments that were parallel to each other and the long axis of RBM cells. The actin filaments of RBM cells on the HA/cpTi surface were localized to the periphery (corresponding to the edge of the filopodium-like processes) well after 120 min. This suggests that actin filaments of RBM cells need to be anchored at the HA/cpTi surface and the numerous HA microcrystals precipitated on the HA/cpTi surface. These findings were similar to the scanning electron microscopic morphology. The peripheral anchorage provide sufficient strength of attachment to allow recognization of actin filaments upon HA/cpTi. The surface of HA/cpTi was more hydrophilic and exhibited markedly improved wettability compared to untreated cpTi, and higher levels of early cell attachment were observed on surfaces after anodization and hydrothermal treatment than on surfaces with untreated cpTi. The results of in vitro experiments suggest that this new method for forming a thin HA layer on the surface of cpTi could be useful to ensure excellent cellular behavior on implant surfaces. The characterization of cell morphology on the thin HA layer formed by anodization and hydrothermal treatment on cpTi implant material suggests that physicochemical or biological conditioning of the implant surface involves implant surface topography.

Perinatal and infant outcome of pregnant patients undergoing chronic hemodialysis

Recently, perinatal outcome in patients undergoing chronic hemodialysis has been improved. But the conditions that will most likely result in successful pregnancy are still obscure. We retrospectively analyzed 15 pregnant patients who were undergoing chronic hemodialysis before pregnancy treated in our perinatal center. We divided these 15 cases into 2 groups: one group of 11 patients whose infants survived and the other group of 4 patients whose infants died 6 h to 8 months after birth due to prematurity. The rate of successful pregnancies having a surviving infant was 73.3% (11/15). We compared the maternal conditions and the progress of pregnancy in the 2 groups. Significant differences (p<0.01) were seen as follows. The patients in the group whose infants survived underwent hemodialysis for a shorter term before pregnancy (1-6 years), most of them (9/11) could produce urine (> or =50 ml/day), and the period of gestation was extended (33.3+/-4.7 weeks), so the infants were heavier (1,782.9+/-678.3 g). All the patients who underwent more than 9 years of hemodialysis could not have a surviving infant. From this we can assume that the shorter the period of dialysis before pregnancy, the better the condition is that is likely to result in women giving birth and the better is their infant's chance of survival.

Formation of propentdyopents and biliverdin, oxidized metabolites of bilirubin, in infants receiving oxygen therapy

BACKGROUND

Bilirubin has antioxidative effects. When bilirubin reacts with reactive oxygen species, oxidized metabolites of bilirubin are formed, such as biliverdin and propentdyopents. A decrease in serum bilirubin concentration and an increase in serum and urinary oxidized metabolites of bilirubin may indicate the protective action of bilirubin against reactive oxygen species.

METHODS

In the in vitro study, we measured the oxidative products of bilirubin formed through the action of O2- by the xanthine-xanthine oxidase system, either as free bilirubin or bilirubin-human serum albumin complex. In the clinical investigation, serum concentrations of (ZZ)-bilirubin (4Z, 15Z-bilirubin), the subfraction and biliverdin, and urinary propentdyopent absorption, were measured in blood and urine samples, respectively, collected from 30 5-day-old neonates with birth weights of 1500-3624 g who had been hospitalized at the Ehime Prefectural Hospital and who had not undergone phototherapy.

RESULTS

In the in vitro study, a significant formation of propentdyopents was observed in aqueous solution. A statistically significant correlation was found between serum (ZZ)-bilirubin concentration and serum biliverdin concentration (r = 0.82, P < 0.0001), but not between serum (ZZ)-bilirubin concentration and urinary propentdyopent absorption. Serum (ZZ)- and serum (ZE)-bilirubin and biliverdin concentrations, and urinary propentdyopent absorption were compared between the groups with and without oxygen therapy. No significant differences were found in serum (ZZ)-bilirubin, serum (ZE)-bilirubin and biliverdin concentration, urinary propentdyopent absorption, serum biliverdin/serum (ZZ)-bilirubin, or urinary propentdyopent absorption/serum (ZZ)-bilirubin. Neither a decrease in serum bilirubin concentration nor an increase in serum biliverdin concentration and urinary propentdyopent absorption after oxygen therapy were demonstrated in the present study.

CONCLUSIONS

In the in vitro study, we demonstrated for the first time that propentdyopents were produced from (ZZ)-bilirubin by the xanthine-xanthine oxidase system but biliverdin was not. In the in vivo study, serum biliverdin concentration and urinary propentdyopent absorption seem to have a different relationship to serum (ZZ)-bilirubin concentration in sick and early neonates.

Enhancement of the systemic and CNS specific delivery of L-dopa by the nasal administration of its water soluble prodrugs

PURPOSE

To study the utility of the nasal route for the systemic delivery of L-dopa using water soluble prodrugs of L-dopa and to examine if this delivery method will result in preferential delivery to the CNS.

METHODS

Several alkyl ester prodrugs of L-dopa were prepared and their physicochemical properties were determined. In vitro hydrolysis rate constants in buffer, rat plasma, rat brain homogenate, rat CSF, and rat nasal berfusate were determined by HPLC. In vivo nasal experiments were carried out in rats. Levels of L-dopa and dopamine in plasma, CSF, and olfactory bulb were determined using HPLC method with electrochemical detection.

RESULTS

All the prodrugs showed improved solubility and lipophilicity with relatively fast in vitro conversion in rat plasma. Absorption was fast following nasal delivery of the prodrugs with bioavailability around 90%. Dopamine plasma levels did not change significantly following nasal administration of the butyl ester prodrug. Olfactory bulb and CSF L-dopa concentration were higher following nasal delivery of the butyl ester prodrug compared to an equivalent intravenous dose.

CONCLUSIONS

Utilization of water soluble prodrugs of L-dopa via the nasal route in the treatment of Parkinson's disease may have therapeutic advantages such as improved bioavailability, decreased side effects, and potentially enhanced CNS delivery.

Dilation and reduced distensibility of carotid artery in patients with abdominal aortic aneurysms

BACKGROUND

Although patients with abdominal aortic aneurysms (AAA) frequently have coexisting systemic atherosclerosis, the dilatative manifestation of AAA is the opposite of the occlusion characteristic of atherosclerotic disease. It has been suggested that this dilatative disease is caused by an alteration in connective tissue metabolism in systemic arterial wall. Such a condition might alter systemic arterial diameter and wall behavior. We investigated arterial characteristics in AAA patients, including morphologic changes and wall mechanics in the carotid artery.

METHODS AND RESULTS

Atherosclerotic intimal changes such as intima-media thickness (IMT), plaque formation, diameter, and wall elasticity of the carotid artery were determined ultrasonographically in patients with AAA (n = 102) and compared with age-matched patients with the atherosclerotic diseases arteriosclerosis obliterans (ASO, n = 115) and coronary artery disease (CAD, n = 123) and with age-matched healthy control patients (CTL, n = 45). Intimal disease in AAA was significantly milder than in ASO, at the same level as CAD, and more severe than in CTL. Although end-diastolic luminal diameters (mm) in AAA (7.05 +/- 1.08), ASO (6.74 +/- 0.18), and CAD (6.66 +/- 0.83) were significantly higher than in CTL (5.97 +/- 0.93), they were also excessively increased compared with the equivalent diameters seen in ASO (P <.01) and CAD (P <.01). Luminal distensibility (x 10(-6) cm(2). dyne(-1)) in AAA (0.83 +/- 0.48) was excessively decreased compared not only with CTL (1.70 +/- 1.11, P <.01) but also with ASO (1.12 +/- 0.47, P <.01) and CAD (1.18 +/- 0.59, P <. 01). These relations remained true when adjusted for blood pressure and luminal diameter. Intra-AAA group analysis showed that distensibility in ruptured cases (n = 14) was significantly lower than in nonruptured cases (n = 88) (0.58 +/- 0.24 vs 0.88 +/- 0.50, P <.05).

CONCLUSIONS

Excessive arterial dilation and reduced distensibility without severe intimal disease were found in the carotid arteries of patients with AAA. This suggests that these patients may be subject to systemic arterial alterations, including structural and functional abnormalities.

Changes in cerebral hemoglobin concentration and oxygen saturation immediately after birth in the human neonate using full-spectrum near infrared spectroscopy

Using full-spectrum near infrared spectroscopy (fsNIRS), we measured changes in oxy- and deoxyhemoglobin (HbO2 and Hb), total hemoglobin (T-Hb) concentration, and hemoglobin oxygen saturation (SbO2) in the brain tissue of seven neonates immediately following birth. It was found that HbO2 rose rapidly within 2-3 min after birth. During the same time, there was a transient increase in T-Hb concentration, after which it decreased together with Hb. SbO2 increased rapidly after birth, from 18% at 1.5 min to about 55% at 5-6 min, followed by a gradual increase of about 10%. Oxygenation in the brain occurred much sooner in three subjects given oxygen for a short time immediately after birth than in those who did not receive oxygen. This preliminary study indicated that dynamic changes occur in cerebral circulation and oxygenation as part of the physiological changes taking place soon after birth.

Energy correction for isolated impurities under periodic boundary conditions

The Coulomb energy of aperiodic systems was investigated. To treat completely isolated disorder in infinite systems, energy correction for a supercell method is presented. We discuss a definition of the correction term, and then consider a direct approach taking into account interactions between charge distribution and an indirect approach based on a multipole expansion. In test calculations for isotropic-charged, anisotropic-charged, and neutral impurities, impurity energies independent of supercell sizes were obtained. The present energy correction can be applied to arbitrary systems and is expected to realize more practical simulations for aperiodic systems.

Specific preinduction of 60-kDa heat shock protein (chaperonin homolog) by TRH does not protect colonic mucosa against acetic acid-induced lesion in rats

In order to study the cytoprotective function of colonic heat shock proteins (HSPs) in vivo, the effect of specific preinduction of HSP60 by thyrotropin-releasing hormone (TRH) administration on the development of acetic acid-induced colonic mucosal lesion was investigated. Expression of 60-kDa, 72-kDa, and 90-kDa heat shock proteins (HSP60, HSP72, and HSP90, respectively) in rat colonic mucosa was investigated by western blot and immunohistochemical analyses before and after TRH administration. Following pretreatment with or without TRH administration, the rats received intrarectal infusion of 5% acetic acid. The colonic mucosal damage was macroscopically evaluated 24 hr after the intrarectal infusion of acetic acid. Expression of HSP60 was significantly increased by TRH administration in the colonic mucosa, whereas HSP72 and HSP90 did not increase. Immunohistochemical study also showed a significant increase in HSP60 in colonic mucosal cells, especially at the surface of the colonic mucosa after TRH administration. No histopathologic alteration was observed in the colonic mucosa after TRH administration. The colonic mucosal damage caused by intrarectal infusion of 5% acetic acid was not prevented by preinduction of HSP60. We demonstrated that specific preinduction of HSP60 by TRH administration did not show cytoprotective function in the colonic mucosa, although this protein plays a crucial role for cytoprotection in the pancreatic acinar cells. Our results indicate that the role of HSP60 may be different in each organ with respect to cytoprotection.

Effects of bilirubin and its photoisomers on direct bilirubin measurement using bilirubin oxidase

We examined the reactivity of human serum albumin-bound bilirubin and its photoisomers as substrates for a direct bilirubin assay using bilirubin oxidase. The reduction of (EZ)-cyclobilirubin reached 100% 5 min after addition of the enzyme at any pH tested (3.5-7.4) in 0.1 mol/L phosphate buffer, whereas the reduction of (ZE)-bilirubin or (ZZ)-bilirubin reached 100% only below pH 4.5 or 5.5, respectively. (ZZ)-Bilirubin and its photoisomers did not react in citrate-lactate buffer at pH 3.7. The circular dichroism spectrum of (ZZ)-bilirubin in this buffer did not show a positive Cotton effect. These results indicate that a three-dimensional structure surrounding the reaction site of bilirubin is important for the reactivity with bilirubin oxidase.

Bradykinin B(2) receptor gene polymorphism is associated with angiotensin-converting enzyme inhibitor-related cough

The appearance of cough in association with angiotensin-converting enzyme (ACE) inhibitors is thought to be related to bradykinin, and it has been speculated that the elicitation of adverse effects is genetically predetermined. Several polymorphisms of the human bradykinin B(2) receptor gene may be involved in ACE inhibitor-related cough. To investigate this possibility, we identified the -58 thymine (T)/cytosine (C) polymorphism in subjects with ACE inhibitor-related cough. We classified the study population into 4 groups: subjects with and without cough that were treated with ACE inhibitors (n=30/30), nontreated essential hypertensive subjects (n=100), and normotensive subjects (n=100). The -58T/C was genotyped by the polymerase chain reaction single-strand conformation polymorphism method. The frequencies of the CC genotype and C allele of -58T/C were significantly higher in the nontreated hypertensive subjects than in the normotensive subjects. Conversely, the frequencies of the TT genotype and T allele were significantly higher in the subjects with cough than in the subjects without cough. These tendencies were more pronounced in females. Among the promoter assays of the human bradykinin B(2) receptor, -58T was found to have a higher transcription rate than that of -58C. This finding seems to suggest that the transcriptional activity of promoter might be involved in the appearance of ACE inhibitor-related cough. A genetic variant of the bradykinin receptor is involved in the elicitation of ACE inhibitor-related cough. It may be possible to predict the side effects of ACE inhibitors in advance.

Experimental study on nerve regeneration through the basement membrane tubes of the nerve, muscle, and artery

We evaluated neurotization after transplantation with lyophilized nerves, muscles, and arteries, and examined the possibility of practical application of long bridging grafts. Grafts of 10 mm and 25 mm of lyophilized nerves, muscles, and arteries harvested from Fisher rats were transplanted to the sciatic nerves of recipient Lewis rats. The histological changes undergone by short grafts were observed at weekly intervals. The sham-operated and isograft groups were used to compare the results of long grafts. In both the nerve and muscle-graft group, regenerated axons grew out through the residual basement membrane tube. But in the muscle graft group, phagocytosis of myofibril debris took longer than that of degenerated axons. No statistical differences were found between results of TSI, induced EMG, and quantitative analysis of myelinated axons in the nerve and muscle graft groups. No neurotization was noted in the long artery graft. In long grafts, laminin found on the basement membrane may not be sufficient to accelerate neurotization, and arteries should not be used for tubulization.

Nasal absorption of ondansetron in rats: an alternative route of drug delivery

PURPOSE

Ondansetron (OND) is a 5-HT3 receptor antagonist that is used therapeutically for the prevention of nausea and vomiting associated with emetogenic cancer therapy. There is a need for nasal drug delivery in specific patient populations where the use of commercially available intravenous and oral dosage forms may be inconvenient and/or unfeasible.

METHODS

OND (Zofran Injection, 2 mg/ml) was administered at a dose of 1 mg/kg to male Sprague-Dawley rats intravenously or intranasally (n = 3 in each group). A special surgical procedure was performed to ensure that the drug solution was held in the nasal cavity. OND was injected into the femoral vein for the intravenous group. Blood samples were collected at appropriate times for 60 min. An HPLC method was employed to determine OND in the plasma.

RESULTS

The results clearly showed that OND was readily and rapidly absorbed through the nasal mucosa of the rat. The peak plasma level was attained within 10 min. OND was also completely absorbed as the plasma concentration-time profiles for the two routes were comparable. The terminal elimination half-lives were also similar.

CONCLUSIONS

The nasal administration route for OND is apparently as effective as the intravenous route. If one considers the limitations of delivering OND orally or intravenously to patients undergoing emetogenic cancer therapy, it becomes obvious that the intranasal route is a potential alternative modality to prevent nausea and vomiting associated with such therapy.

Three patients with adrenal tumors having been treated simply for diabetes mellitus

Three patients with functional adrenal tumors, Cushing's syndrome, primary aldosteronism and pheochromocytoma, who underwent adrenalectomy and were subsequently cured, were studied. All these patients had been treated for diabetes for several years before the diagnosis of adrenal tumors. In each case the state of diabetes before and after surgery, including parameters of insulin secretion and insulin resistance, was compared to demonstrate how the adrenal disorder influenced the nature of diabetes. In the case of Cushing's syndrome the hypercortisolemia caused insulin resistance in the peripheral tissues. In the case of primary aldosteronism, excessive production of aldosterone diminished insulin secretion possibly through hypokalemia. Pheochromocytoma affected both insulin secretion and insulin sensitivity through hypersecretion of catecholamines. In all these patients the adrenal tumors were found in clinical contexts other than management of diabetes itself. By careful retrospective review of these three patients' history, several important points that might have drawn the physician's attention to the underlying adrenal disorders were pointed out. These included past history of acute myocardial infarction with onset at unexpectedly young age in the case of Cushing's syndrome and unexpectedly high insulin resistance for the patient's body mass index in the case of pheochromocytoma.

Effects of A1 and A2 adenosine receptor antagonists on the induction and reversal of long-term potentiation in guinea pig hippocampal slices of CA1 neurons

1. Using simultaneous recordings of the field EPSP and the population spike in the CA1 neurons of guinea pig hippocampal slices, we confirmed that delivery of a high-frequency stimulation (tetanus: 100 pulses at 100 Hz) produced robust long-term potentiation of synaptic efficacy (LTP) in two independent components, a synaptic component that increases field excitatory postsynaptic potentials (EPSPs) and a component that results in a larger population spike amplitude for a given EPSP size (E-S potentiation). 2. In the same cells, reversal of LTP (depotentiation; DP) in the field EPSP and in the E-S component is achieved by delivering low-frequency afferent stimulation (LFS: 1 Hz, 1000 pulses) 20 min after the tetanus. 3. When the tetanus or LFS was applied to CA1 inputs in the presence of an adenosine A1 receptor antagonist, 8-cyclopentyltheophylline (1 microM), the field EPSP was enhances in LTP and attenuated in DP, while the E-S relationship was not significantly affected in either LTP or DP. 4. When similar experiments were performed using an A2 receptor antagonist, CP-66713 (10 microM), the field EPSP was blocked in LTP but facilitated in DP, while E-S potentiation was enhanced during both LTP and DP. 5. The results show that endogenous adenosine, acting via A1 or A2 receptors, modulates both the synaptic and the E-S components of the induction and reversal of LTP. Based on the results, we discuss the key issue of the contribution of these receptors to the dynamics of neuronal plasticity modification in hippocampal CA1 neurons.

Smad7 mediates apoptosis induced by transforming growth factor beta in prostatic carcinoma cells

Transforming growth factor beta (TGF-beta) is an important regulator of apoptosis in some cell types, but the underlying molecular mechanisms are largely unknown. TGF-beta signals through type I and type II receptors and downstream effector proteins, termed Smads. TGF-beta induces the phosphorylation of Smad2 and Smad3 (receptor-activated Smads) which associate with Smad4 and translocate to the nucleus, where they regulate gene transcription [1]. Smad7 protein is induced by TGF-beta1 and has been classified as an inhibitory Smad. Smad7 prevents phosphorylation of receptor-activated Smads, thereby inhibiting TGF-beta-induced signaling responses [1]. Smad7 expression is increased in rat prostatic epithelial cells undergoing apoptosis as a result of castration [2]. Here we have shown that TGF-beta1 treatment or ectopic expression of Smad7 in human prostatic carcinoma cells (PC-3U) induces apoptosis. Furthermore, TGF-beta1-induced apoptosis was prevented by inhibition of Smad7 expression, by antisense mRNA in stably transfected cell lines or upon transient transfection with antisense oligonucleotides in several investigated cell lines. These findings provide evidence for a new effector function for Smad7 in TGF-beta1 signaling.

Colonic varices ruptured via drainage catheter after extended right hepatectomy

Extended right hepatectomy was performed on a 69-year-old woman with bile duct carcinoma of the hepatic hilum. Three weeks after the operation, an abscess was detected at the resected surface and a drainage catheter was inserted. The patient was discharged with the drainage catheter in place and followed-up at a local hospital. Three months later, the drainage catheter was removed. Bleeding immediately occurred through the fistula, and fistulography revealed varices. Angiography demonstrated right colonic varices, and the fistula was embolized with coils. There was no further bleeding. In conclusion, colonic varices that ruptured via a fistula of a drainage catheter were embolized through the fistula. Embolization of the fistula was useful in stopping the bleeding.

Stent-graft placement for pseudoaneurysm of the aorta

PURPOSE

To evaluate the use of endovascular stent-graft placement to repair pseudoaneurysm of the aorta.

METHODS

Six patients were treated with stent-grafts for pseudoaneurysms located in the thoracic aorta (n=2), thoracoabdominal aorta (n=3), and abdominal aorta (n=1). Etiologies of the pseudoaneurysms included leakage from surgical graft, penetrating atherosclerotic ulcer, pneumonia, perforated esophageal ulcer, and mycotic aneurysm. All patients were clinically considered to be at high surgical risk.

RESULTS

Stent-grafts were successfully placed in all patients. There was one death in the perioperative period due to massive hemoptysis before stent-grafting. Two patients died of persistent infection. One patient with persistent perigraft leak died of rupture. Two other patients needed no further therapy for pseudoaneurysm.

CONCLUSION

Stent-graft placement for pseudoaneurysm of the aorta can play the role of a temporizing method prior to surgical repair in high-risk cases and be a therapeutic alternative in cases without infection or perigraft leakage.

The effects of the ALDH2*1/2, CYP2E1 C1/C2 and C/D genotypes on blood ethanol elimination

The effects of CYP2E1 genotypes on the blood ethanol and acetaldehyde levels were investigated in a pair of Japanese volunteers whose ADH2, ADH3 and ALDH2 genotypes were identical but whose CYP2E1 genotypes were different. In the same way, the effects of ALDH2 and ADH2 on the ethanol elimination kinetics were also studied. The predicting 95% confidence bounds determined on regression analysis of the data suggested that after venous injection of ethanol, the blood ethanol and acetaldehyde concentrations in a volunteer normal homozygous for ALDH2 (ALDH2*1/1) were lower than in a heterozygous one (ALDH2*1/2). Also, the blood ethanol and acetaldehyde concentrations in a volunteer with the c2 and C alleles of CYP2E1 (c1/c2 and C/D) were lower than in one without the c2 and C alleles (c1/c1 and D/D). However, there were no significant differences in the blood ethanol and acetaldehyde concentrations between volunteers with ADH2*1 (ADH2*1/1) and without ADH2*1 (ADH2*1/2).

Chemiluminescence because of the production of reactive oxygen species in the lungs of newborn piglets during resuscitation periods after asphyxiation load

Reactive oxygen species are regarded as a possible cause of many diseases. However, there are few reports offering in vivo and in situ proof of the direct involvement of reactive oxygen species in the pathogenesis of disease. In the present study, the luciferin derivative 2-methyl-6-[4-methoxyphenyl]-3,7-dihydroimidazo [1,2-alpha] pyrazin-3-one (MCLA) was used to investigate the amount of reactive oxygen species produced during resuscitation after asphyxiation load in newborn piglets. The animals were first asphyxiated by stopping respiration for 4 min, and then resuscitated using 100% oxygen. When physiologic saline solution was administered, lung surface chemiluminescence had a mean value of 2, whereas with MCLA, a maximum luminescence of 580 was seen, demonstrating the possibility of measuring reactive oxygen species in vivo and in situ using MCLA. In a group in which resuscitation after acute asphyxiation was performed with 21% oxygen, the relative maximum lung surface chemiluminescence was 59.5+/-39, whereas that for a group in which resuscitation was performed using 100% oxygen had a significantly higher value of 186.1+/-72.5. Consequently, ventilation and especially resuscitation by 100% oxygen may represent a potential danger.

Characterization of a novel nonpeptide vasopressin V(2)-agonist, OPC-51803, in cells transfected human vasopressin receptor subtypes

We discovered the first nonpeptide arginine-vasopressin (AVP) V(2)-receptor agonist, OPC-51803. Pharmacological properties of OPC-51803 were elucidated using HeLa cells expressing human AVP receptor subtypes (V(2), V(1a) and V(1b)) and compared with those of 1-desamino-8-D-arginine vasopressin (dDAVP), a peptide V(2)-receptor agonist. OPC-51803 and dDAVP displaced [(3)H]-AVP binding to human V(2)- and V(1a)-receptors with K(i) values of 91.9+/-10.8 nM (n = 6) and 3.12+/-0.38 nM (n = 6) for V(2)-receptors, and 819+/-39 nM (n = 6) and 41.5+/-9.9 nM (n = 6) for V(1a)-receptors, indicating that OPC-51803 was about nine times more selective for V(2)-receptors, similar to the selectivity of dDAVP. OPC-51803 scarcely displaced [(3)H]-AVP binding to human V(1b)-receptors even at 10(-4) M, while dDAVP showed potent affinity to human V(1b)-receptors with the K(i) value of 13.7+/-3.2 nM (n = 4). OPC-51803 concentration-dependently increased cyclic adenosine 3', 5'-monophosphate (cyclic AMP) production in HeLa cells expressing human V(2)-receptors with an EC(50) value of 189+/-14 nM (n = 6). The concentration-response curve for cyclic AMP production induced by OPC-51803 was shifted to the right in the presence of a V(2)-antagonist, OPC-31260. At 10(-5) M, OPC-51803 did not increase the intracellular Ca(2+) concentration ([Ca(2+)](i)) in HeLa cells expressing human V(1a)-receptors. On the other hand, dDAVP increased [Ca(2+)](i) in HeLa cells expressing human V(1a)- and V(1b)-receptors in a concentration-dependent fashion. From these results, OPC-51803 has been confirmed to be the first nonpeptide agonist for human AVP V(2)-receptors without agonistic activities for V(1a)- and V(1b)-receptors. OPC-51803 may be useful for the treatment of AVP-deficient pathophysiological states and as a tool for AVP researches.