Gel phantom study of a cryosurgical probe with a thermosiphon effect and liquid nitrogen-cooled aluminum thermal storage blocks.

Cryosurgery is a minimally invasive treatment for certain types of cancers. Argon-based cryosurgical devices are available at present, however a large compressed gas cylinder with the pressure of 300 atmospheres is needed. To overcome these drawbacks, we developed a new cryosurgical probe measuring about 50 cm in length with separate lumens inside for liquid and gaseous ethylene to be used as a thermosiphon and liquid nitrogen-cooled aluminum thermal storage blocks. The probe needle was 8 cm in length and 3 mm in outer diameter. To investigate the freezing capabilities of our new cryosurgical system we inserted the needle 5cm into a poly-acrylamide gel phantom warmed to 36.5 ℃. Thermal storage blocks made of aluminum, cooled at -196 ℃ in liquid nitrogen, were attached to the condenser of the probe and replaced with thermal storage blocks every 4 to 5 minutes to compensate for warming. We took digital camera images of the ice ball at the needle and measured the temperature in certain locations of the cryoprobe. Ice ball formation started at one minute after cooling. The sizes (longest diameter × minimum diameter) at 10, 20 and 30 minutes after the start of the procedure were 4.5×2.1, 4.5×3.1 and 4.6×3.7 cm, respectively. During the procedure the minimum temperature of the condenser was -85 ℃ and the needle was -65 ℃. This newly developed compact cryosurgical probe with thermosiphon effect and cooled thermal storage blocks created an ice ball that can be used for cryosurgery within 20 minutes.

Serum indoleamine 2,3-dioxygenase activity predicts prognosis of pulmonary tuberculosis.

Tuberculosis (TB) continues to be a major health problem, and there are few biomarkers for predicting prognosis. Indoleamine 2,3-dioxygenase (IDO), a potent immunoregulatory molecule, catalyzes the rate-limiting step of tryptophan (Trp) degradation in the kynurenine (Kyn) pathway. An increase in IDO activity determined by the serum Trp/Kyn ratio has been shown to be associated with poor prognosis in cancers and bacteremia. In TB, however, there are no studies measuring serum IDO activity to determine its clinical significance. We evaluated serum IDO activity with 174 pulmonary TB (PTB) patients and 85 controls, using liquid chromatography/electrospray ionization tandem mass spectrometry. IDO activity was estimated by calculating the serum Kyn-to-Trp ratio. PTB patients had significantly higher Kyn concentrations and IDO activity and significantly lower Trp concentrations (P < 0.0001, P < 0.0001, and P < 0.0001, respectively) than the controls. Of 174 PTB patients, 39 (22.4%) died. The patients who died had significantly higher concentrations of Kyn and significantly lower Trp concentrations, resulting in significantly higher IDO activity (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). In a receiver operating characteristic (ROC) analysis, serum IDO activity had the highest area under the curve (0.850), and this activity was an independent prognostic factor in multivariate analysis. These results suggest that serum IDO activity can be used as a novel prognostic marker in PTB.

Transcriptional repression of Cdc25B by IER5 inhibits the proliferation of leukemic progenitor cells through NF-YB and p300 in acute myeloid leukemia.

The immediately-early response gene 5 (IER5) has been reported to be induced by γ-ray irradiation and to play a role in the induction of cell death caused by radiation. We previously identified IER5 as one of the 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP)-induced transcriptional responses in AML cells, using microarrays that encompassed the entire human genome. However, the biochemical pathway and mechanisms of IER5 function in regulation of the cell cycle remain unclear. In this study, we investigated the involvement of IER5 in the cell cycle and in cell proliferation of acute myeloid leukemia (AML) cells. We found that the over-expression of IER5 in AML cell lines and in AML-derived ALDH(hi) (High Aldehyde Dehydrogenase activity)/CD34(+) cells inhibited their proliferation compared to control cells, through induction of G2/M cell cycle arrest and a decrease in Cdc25B expression. Moreover, the over-expression of IER5 reduced colony formation of AML-derived ALDH(hi)/CD34(+) cells due to a decrease in Cdc25B expression. In addition, over-expression of Cdc25B restored TMPP inhibitory effects on colony formation in IER5-suppressed AML-derived ALDH(hi)/CD34(+) cells. Furthermore, the IER5 reduced Cdc25B mRNA expression through direct binding to Cdc25B promoter and mediated its transcriptional attenuation through NF-YB and p300 transcriptinal factors. In summary, we found that transcriptional repression mediated by IER5 regulates Cdc25B expression levels via the release of NF-YB and p300 in AML-derived ALDH(hi)/CD34(+) cells, resulting in inhibition of AML progenitor cell proliferation through modulation of cell cycle. Thus, the induction of IER5 expression represents an attractive target for AML therapy.

Small GTPase RAB45-mediated p38 activation in apoptosis of chronic myeloid leukemia progenitor cells.

Chronic myelogenous leukemia (CML) is characterized by a reciprocal chromosomal translocation (9;22) that generates the Bcr-Abl fusion gene. BCR-ABL transforming activity is mediated by critical downstream signaling pathways that are aberrantly activated by tyrosine kinases. However, the mechanisms of BCR-ABL anti-apoptotic effects and the signaling pathways by which BCR-ABL influences apoptosis in BCR-ABL-expressing cells are poorly defined. In this study, we found that treatment with ABL kinase inhibitors or depletion of BCR-ABL induced the expression of RAB45 messenger RNA and protein and induced apoptosis via reduction of mitochondrial membrane potential and p38 activation in CML cell lines and BCR-ABL(+) progenitor cells from CML patients. Overexpressed RAB45 induced the activation of caspases-3 and -9 and reduced the expression of Survivin, XIAP, c-IAP1 and c-IAP2 in CML cells. Moreover, in colony-forming cells derived from CML-aldehyde dehydrogenase(hi)/CD34(+) cells, treatment with ABL kinase inhibitors induced RAB45 expression and reduced mitochondrial membrane potential, resulting in inhibited colony formation of Bcr-Abl(+) progenitor cells. The overexpression of RAB45 significantly decreased colony numbers and induced apoptosis through the activation of caspases-3 and -9. Furthermore, the overexpression of RAB45 increased the phosphorylation levels of p38, resulting in the induction of apoptosis and inhibition of proliferation of CML progenitor cells. Our results identify a new signaling molecule involved in BCR-ABL modulation of apoptosis and suggest that RAB45 induction strategies may have therapeutic utility in patients with CML.

Serum activity of indoleamine 2,3-dioxygenase predicts prognosis of community-acquired pneumonia.

OBJECTIVES: Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step of tryptophan (Trp) degradation in the kynurenine (Kyn) pathway. By depleting Trp, IDO plays a critical role in inducing immune suppression and tolerance. The aim of present study was to investigate serum IDO activity, determined by Kyn-to-Trp ratio (Kyn/Trp ratio), in community-acquired pneumonia (CAP) and to examine its clinical significance. METHODS: This study subjects consisted of 129 consecutive patients with CAP and 64 healthy controls. The concentrations of Kyn and Trp were measured simultaneously by liquid chromatography/electrospray ionization tandem mass spectrometry. RESULTS: The CAP patients had significantly higher Kyn concentrations and significant lower Trp concentrations than the controls (p < 0.0001 and p < 0.0001, respectively). Accordingly, IDO activity was significantly higher (2.4-fold) in the patients than in the controls (p < 0.0001). IDO activity correlated well with PSI (Pneumonia Severity Index) and CURB65 (p = 0.0005 and p < 0.0001, respectively). Moreover, the IDO activity and Kyn concentration were significantly higher in the nonsurvivors and were found to predict mortality in multivariate analysis. CONCLUSIONS: IDO activity was increased in CAP, and this activity was associated with the severity and outcome of this disease. These results suggest that IDO activity can predict prognosis of CAP.

Relationship between an increased serum kynurenine/tryptophan ratio and atherosclerotic parameters in hemodialysis patients.

Essential amino acid tryptophan (Trp) is mainly catabolized by indoleamine 2,3-dioxygenase, which leads to the formation of kynurenine (Kyn). In this study, we reexamined whether an increased indoleamine 2,3-dioxygenase activity, as estimated by the Kyn/Trp ratio (µM/mM), is associated with atherosclerotic parameters in hemodialysis (HD) patients. Serum Trp and Kyn were measured in 243 HD patients by liquid chromatography/electrospray ionization tandem mass spectrometry. We measured carotid artery intima-medial thickness, brachial-ankle pulse wave velocity, ankle-brachial pressure index, and the cardio-ankle vascular index. Log-transformed Kyn/Trp ratio was significantly correlated with log-transformed time on HD (ρ=0.28, P<0.01), log-transformed highly sensitive C-reactive protein (ρ=0.20, P<0.01), and peripheral total lymphocyte count (ρ=-0.13, P<0.05). A significant association was found between log-transformed Kyn/Trp ratio and mean carotid artery intima-medial thickness (ρ=0.18, P<0.01). Mean carotid artery intima-medial thickness was significantly higher in the lowest quartile of Kyn/Trp ratio (<165) (0.62±0.12 mm) when compared with the highest quartile (≥304) (0.68±0.15 mm) (P<0.01). Ankle-brachial pressure index was lower in the second quartile (1.01±0.20), the third quartile (1.01±0.19), and the fourth quartile (1.03±0.15) compared with that in the first quartile (1.09±0.13) (P<0.05). It follows from these findings that the Kyn/Trp ratio increases with time on HD, and is associated with advanced atherosclerotic changes in chronic HD patients.

Preparation and characterization of novel 4-bromo-3,4-dimethyl-1-phenyl-2-phospholene 1-oxide and the analogous phosphorus heterocycles or phospha sugars.

4-Bromo-3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (3c) was first synthesized from 3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (2c) by a bromo-radical substitution reaction occurred at C-4 position by N-bromosuccinimide and 2,2'-azobisisobutyronitrile. The novel phospha sugar analogue 3c exerted high anti-proliferative effect on U937 cells evaluated by MTT in vitro methods and was much more efficient than that of Gleevec, which is known as a molecule targeting chemotherapeutical agent. The substitution of 2-phospholenes at C-3 and C-4 position with methyl groups as well as 4-bromo substituent suggests a good anti-proliferative effect.

Synthesis, in vitro and in vivo studies of Gd-DTPA-XDA-D1-Glc(OH) complex as a new potential MRI contrast agent.

A new type of dendritic molecules Gd-DTPA-XDA-D1-Glc(OH), which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with two glucose moieties on the molecular surfaces, were readily synthesized with high yield. The structures were established by IR, (1)H, (13)C NMR, and mass spectral studies. Its bio-distribution patterns were evaluated on rats.

Increased serum kynurenine/tryptophan ratio correlates with disease progression in lung cancer.

BACKGROUND: Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step of tryptophan (Trp) degradation along the kynurenine (Kyn) pathway. By depleting tryptophan, IDO is considered to be a fundamental immune escape mechanism for tumor cells. However, IDO expression in lung cancer has not been explored thoroughly. Thus, the present study investigated IDO activity determined by serum Trp and Kyn concentrations in lung cancer and the correlation between the IDO activity and clinical parameters. METHOD: The concentrations of Trp and Kyn were measured simultaneously by liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) in the sera of 123 patients with lung cancer and 45 healthy controls. The IDO activity was estimated by calculating the serum Kyn-to-Trp ratio (Kyn/Trp ratio). RESULTS: Trp concentrations were significantly lower in patients with lung cancer than in healthy controls (62.6+/-15.8microM vs. 71.1+/-11.8microM, respectively; p=0.0007), while Kyn concentrations were significantly higher in patients compared with the controls (2.82+/-1.17microM vs. 2.30+/-0.56microM, respectively; p=0.0036). The IDO activity determined by the Kyn/Trp ratio was significantly higher in the patients than in the controls (47.1+/-21.3 vs. 32.9+/-9.10, respectively; p<0.0001). In addition, patients in the advanced stages of lung cancer had significantly lower Trp concentrations and higher IDO activity than those in the early stages (p=0.0058 and p=0.0209, respectively). CONCLUSIONS: IDO activity was increased in lung cancer patients, and higher IDO activity was associated with more advanced stages. These results suggest that increased IDO activity is involved in disease progression of lung cancer, possibly through its immunosuppressive effect.

Development and pharmacologic characterization of deoxybromophospha sugar derivatives with antileukemic activity.

Here, we synthesized two phospha sugar derivatives, 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP) and 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DMPP) by reacting 3-methyl-1-phenyl-2-phospholene 1-oxide with bromine, and investigated their potential as antileukemic agents in cell lines. Both agents showed inhibitory effects on leukemia cell proliferation, with mean IC(50) values of 6.25 micromol/L for TMPP and 23.7 micromol/L for DMPP, indicating that inhibition appeared to be dependent on the number of bromine atoms in the structure. Further, TMPP at 10 micromol/L and DMPP at 20 micromol/L induced G2/M cell cycle block in leukemia cells, and TMPP at 20 micromol/L induced apoptosis in these cells. TMPP treatment effected a reduction in both cell cycle progression signals (FoxM1, KIS, Cdc25B, Cyclin D1, Cyclin A, and Aurora-B) and tumor cell survival (p27(Kip1) and p21(Cip1)), as well as induced the activation of caspase-3 and -9. Further, treatment with TMPP significantly reduced the viability of AML specimens derived from AML patients, but only slightly reduced the viability of normal ALDH(hi) progenitor cells. We also observed that FoxM1 mRNA was overexpressed in AML cells, and treatment with TMPP reduced FoxM1 mRNA expression in AML cells. Here, we report on the synthesis of TMPP and DMPP and demonstrate that these agents hinder proliferation of leukemia cells by FoxM1 suppression, which leads to G2/M cell cycle block and subsequent caspase-3-dependent apoptosis in acute leukemia cells. These agents may facilitate the development of new strategies in targeted antileukemic therapy.

Synthesis and in vitro evaluation of 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide for potential anti-proliferative effects.

A novel phospha sugar analogue, 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DBMPP), was prepared from 1-phenyl-3-methyl-2- phospholene 1-oxide and evaluated by in vitro MTT method forleukemia cells and microscopic observations forsolid tumor cells, e.g., stomach cancer cells. The evaluation revealed clearly that the synthesized phospha sugar analogue DBMPP has competent potentials and excellent anti-cancer activities that killed selectively and specifically the leukemia cells of cell lines of K562 and U937 but did not give any damages on healthy leukocyte. Moreover it was revealed that DBMPP killed solid cancer cells such as stomach cancer cells and melanoma of cell lines of MKN45 and G361. Therefore, DBMPP should exert anti-proliferative effects for different kinds of tumor cells based on the in vitro evaluations. The cell cycle analyses by flow cytometry for K562 and U937 cells clearly demonstrated that the mechanism of the anti-proliferative effect on the human tumor cells is apoptosis induced by DBMPP.

Effect of prophylactically administered edaravone during antegrade cerebral perfusion in a canine model of old cerebral infarction.

OBJECTIVE: Reactive free radical species are thought to be involved in postoperative neurologic dysfunction after antegrade selective cerebral perfusion in brains with old infarction. We assessed the brain protective effect of prophylactically administered edaravone, a free radical scavenger, for antegrade selective cerebral perfusion in brains with or without old infarction in a canine model. METHODS: A canine model of old cerebral infarction was created by injecting cylindric silicone embolus into the middle cerebral artery. Animals showing obvious neurologic deficits and surviving 4 weeks or longer were included in the model. Deep hypothermia with antegrade selective cerebral perfusion was performed in both intact (non-edaravone, group A; edaravone-treated, group B) and infarcted animals (non-edaravone, group C; edaravone-treated, group D). Serum concentrations of malondialdehyde, hexanoyl-lysine, glutamate, and venous-arterial lactate difference were measured, and central conduction time and amplitude of somatosensory evoked potentials were assessed during the operation. RESULTS: Compared with the intact groups, serum concentrations of malondialdehyde and hexanoyl-lysine in group C significantly increased at the end of antegrade selective cerebral perfusion, whereas that of glutamate did so in the rewarming phase. Increases in all these biochemical parameters were suppressed in group D. In group C, the venous-arterial lactate difference was significantly greater in the rewarming phase at 28 degrees C compared with intact groups. A significant prolongation of postoperative central conduction time and decrease in neuronal activity were detected in group C, both of which recovered in group D. CONCLUSION: Prophylactic administration of edaravone exerted a significant protective effect against postoperative neurologic dysfunction after antegrade selective cerebral perfusion in a canine model with old cerebral infarction.

Comparison of pH management during antegrade selective cerebral perfusion in canine models with old cerebral infarction.

OBJECTIVE: We sought to examine the influence on the brain, with or without old infarction, of pH management during antegrade selective cerebral perfusion in a canine model. METHODS: A cerebral infarct canine model was created by injecting a cylindrical silicone embolus. Dogs that had obvious neurologic deficits and had survived for 4 weeks or more were included in the model. Deep hypothermia with antegrade selective cerebral perfusion was performed in intact mongrel dogs (alpha-stat: group A, n = 6; pH-stat: group B, n = 6) and mongrel dogs with infarctions (alpha-stat: group C, n = 6; pH-stat: group D, n = 6). Maxillary vein saturation of oxygen, venous-arterial lactate difference, and serum concentrations of malondialdehyde and glutamate were measured and central conduction times and amplitude in somatosensory evoked potentials were assessed during the operation. RESULTS: During the experimental procedure, the maxillary vein saturation of oxygen was significantly less (P <.05), whereas the venous-arterial lactate difference was significantly greater (P <.05) in the cooling phase to 28 degrees C in group C than in the other groups. The pH-stat group showed significantly greater arterial Paco(2) and lower pH than the alpha-stat group during the period between the cooling to 28 degrees C and the rewarming to 28 degrees C (P <.05). Other intraoperative parameters did not show any difference among the groups. In group C the serum concentrations of malondialdehyde and glutamate significantly increased, as did the central conduction time, whereas in both groups C and D the amplitude ratio decreased significantly. CONCLUSIONS: This experiment suggests that pH-stat management during antegrade selective cerebral perfusion provides more effective protection for a brain with old infarction than alpha-stat management.

Control of oxalate formation from L-hydroxyproline in liver mitochondria.

Serine:pyruvate/alanine:glyoxylate aminotransferase (SPT/AGT) is largely located in mitochondria in carnivores, whereas it is entirely found within peroxisomes in herbivores and humans. In rat liver, SPT/AGT is found in both of these organelles, and only the mitochondrial enzyme is markedly induced by glucagon. Although SPT/AGT is a bifunctional enzyme involved in the metabolism of both L-serine and glyoxylate, its contribution to L-serine metabolism is independent of mitochondrial or peroxisomal localization (Xue HH et al., J Biol Chem 274: 16028-16033, 1999). Therefore, the species-specific and food habit-dependent organelle distribution might be required for proper metabolism of glyoxylate at the subcellular site of its formation. Glyoxylate formation from glycolate and that from L-hydroxyproline have been shown to occur in peroxisomes and mitochondria, respectively. The present study found that urinary excretion of oxalate was markedly increased when a large dose of L-hydroxyproline or glycolate was administered to rats. Oxalate formation from L-hydroxyproline but not that from glycolate was significantly reduced when mitochondrial SPT/AGT had been induced by glucagon. The hydroxyproline content of collagen is 10 to 13%, and collagen accounts for about 30% of total animal protein; therefore, these results suggest that an important role of mitochondrial SPT/AGT in carnivores is to convert L-hydroxyproline-derived glyoxylate into glycine in situ, preventing undesirable overflow into the production of oxalate.

Kunitz-type protease inhibitor bikunin disrupts phorbol ester-induced oligomerization of CD44 variant isoforms containing epitope v9 and subsequently suppresses expression of urokinase-type plasminogen activator in human chondrosarcoma cells.

We previously found that bikunin (bik), a Kunitz-type protease inhibitor, suppresses phorbol ester (PMA)-stimulated expression of urokinase-type plasminogen activator (uPA). In the present study, we tried to answer this mechanism using human chondrosarcoma HCS-2/8 cells. Our results showed the following novel findings: (a) the standard form of CD44 (CD44s; 85 kDa) is expressed in both unstimulated and PMA-stimulated cells, while CD44v isoforms containing epitope v9 (110 kDa) are strongly up-regulated in response to treatment with PMA; (b) CD44v isoforms containing epitope v9 present on the same cell exclusively form aggregates in stimulated cells; (c) induction of uPA mRNA expression could be achieved by using a second cross-linker antibody to cross-link Fab monomers of anti-CD44; (d) co-treatment of stimulated cells with anti-CD44 mAb alone or anti-CD44v9 mAb alone suppresses PMA-induced clustering of CD44, which results in inhibition of uPA overexpression; (e) bikunin efficiently disrupts PMA-induced clustering of CD44, but does not prevent PMA-induced up-regulation of CD44v isoforms containing epitope v9; and (f) after exposure to bik, approximately 150-kDa band is mainly detected with immunoprecipitation and this band is shown to be a heterodimer composed of the 110-kDa v9-containing CD44v isoforms and a 45-kDa bik receptor (bik-R). In conclusion, we provide, for the first time, evidence that the bik-R can physically interact with the CD44v isoforms containing epitope v9 and function as a repressor to down-regulate PMA-stimulated uPA expression, at least in part, by preventing clustering of CD44v isoforms containing epitope v9.