Sequential Changes of Total Adenine Nucleotide and Adenylic-Acid Energy Charge in Muscles of Rats after Death / 法医学杂志

Objective To determine the purine adenylate [adenosine triphosphate （ATP）, adenosine diphosphate （ADP）, adenosine monophosphate （AMP）] content in the muscles of both hind limbs of rats at different postmortem interval （PMI）, calculate the changes in the total adenine nucleotide （TAN） content and the adenylic-acid energy charge （AEC）, and explore their relationship with PMI. Methods Healthy rats were sacrificed by cervical dislocation and kept at 20 ℃. The muscles of their hind limbs were extracted at 0, 24, 48, 72, 96, 120, 144, and 168 h after death. Reversed-phase high performance liquid chromatography was used to determine the content of purine adenylates, the TAN and AEC of the muscles of the both hind limbs were calculated, and the related regression equations of their relationship with PMI were established. Results Within 168 h of death of rats, the trend of ATP change was different from ADP, and the content of AMP continuously increased. The TAN value gradually increased with the extension of PMI, and the AEC showed a downward trend within 168 h after death. Among them, the patterns of AEC changes with PMI were obvious, the correlation coefficient was high （ R2=0.903）, and the curve fitting relationship was good; the fitting relationship between ATP, ADP, AMP, TAN and PMI was poor （ R2=0.198-0.754）. Conclusion The postmortem change patterns of AEC provide new research ideas for PMI estimation in the forensic field.

The role of adenine nucleotide and its metabolites in regulating the homeostasis of glucose and lipid metabolism / 生理学报

Glucose and lipid metabolism is the most fundamental metabolic activity of higher organisms. This process is affected by both genetic polymorphisms and environmental factors. Excessive uptake and accumulation of lipids lead to obesity and disorder of glucose metabolic homeostasis characterized by insulin resistance and hyperglycemia, suggesting that the cross-regulation between lipid and glucose metabolism happens precisely at organ, cellular and molecular levels by known mechanisms. Adenine nucleotides and their metabolites have emerged as mediators in the mutual regulation of glucose and lipid metabolism. This review summarizes the roles of purinergic signaling induced by fatty acids in glucose metabolism and the development of type 2 diabetes.

Adenine attenuates lipopolysaccharide-induced inflammatory reactions

A nucleobase adenine is a fundamental component of nucleic acids and adenine nucleotides. Various biological roles of adenine have been discovered. It is not produced from degradation of adenine nucleotides in mammals but produced mainly during polyamine synthesis by dividing cells. Anti-inflammatory roles of adenine have been supported in IgE-mediated allergic reactions, immunological functions of lymphocytes and dextran sodium sulfate-induced colitis. However adenine effects on Toll-like receptor 4 (TLR4)-mediated inflammation by lipopolysaccharide (LPS), a cell wall component of Gram negative bacteria, is not examined. Here we investigated anti-inflammatory roles of adenine in LPS-stimulated immune cells, including a macrophage cell line RAW264.7 and bone marrow derived mast cells (BMMCs) and peritoneal cells in mice. In RAW264.7 cells stimulated with LPS, adenine inhibited production of pro-inflammatory cytokines TNF-α and IL-6 and inflammatory lipid mediators, prostaglandin E₂ and leukotriene B₄. Adenine impeded signaling pathways eliciting production of these inflammatory mediators. It suppressed IκB phosphorylation, nuclear translocation of nuclear factor κB (NF-κB), phosphorylation of Akt and mitogen activated protein kinases (MAPKs) JNK and ERK. Although adenine raised cellular AMP which could activate AMP-dependent protein kinase (AMPK), the enzyme activity was not enhanced. In BMMCs, adenine inhibited the LPS-induced production of TNF-α, IL-6 and IL-13 and also hindered phosphorylation of NF-κB and Akt. In peritoneal cavity, adenine suppressed the LPS-induced production of TNF-α and IL-6 by peritoneal cells in mice. These results show that adenine attenuates the LPS-induced inflammatory reactions.

Functional characterization of human equilibrative nucleoside transporter 1

Equilibrative nucleoside transporters (ENTs), which facilitate cross-membrane transport of nucleosides and nucleoside-derived drugs, play an important role in the salvage pathways of nucleotide synthesis, cancer chemotherapy, and treatment for virus infections. Functional characterization of ENTs at the molecular level remains technically challenging and hence scant. In this study, we report successful purification and biochemical characterization of human equilibrative nucleoside transporter 1 (hENT1) in vitro. The HEK293F-derived, recombinant hENT1 is homogenous and functionally active in proteoliposome-based counter flow assays. hENT1 transports the substrate adenosine with a K of 215 ± 34 µmol/L and a V of 578 ± 23.4 nmol mg min. Adenosine uptake by hENT1 is competitively inhibited by nitrobenzylmercaptopurine ribonucleoside (NBMPR), nucleosides, deoxynucleosides, and nucleoside-derived anti-cancer and anti-viral drugs. Binding of hENT1 to adenosine, deoxyadenosine, and adenine by isothermal titration calorimetry is in general agreement with results of the competitive inhibition assays. These results validate hENT1 as a bona fide target for potential drug target and serve as a useful basis for future biophysical and structural studies.

Knockdown of Bcl-xL Enhances Growth-Inhibiting and Apoptosis-Inducing Effects of Resveratrol and Clofarabine in Malignant Mesothelioma H-2452 Cells

Mcl-1 and Bcl-xL, key anti-apoptotic proteins of the Bcl-2 family, have attracted attention as important molecules in the cell survival and drug resistance. In this study, we investigated whether inhibition of Bcl-xL influences cell growth and apoptosis against simultaneous treatment of resveratrol and clofarabine in the human malignant mesothelioma H-2452 cells. Resveratrol and clofarabine decreased Mcl-1 protein levels but had little effect on Bcl-xL levels. In the presence of two compounds, any detectable change in the Mcl-1 mRNA levels was not observed in RT-PCR analysis, whereas pretreatment with the proteasome inhibitor MG132 led to its accumulation to levels far above basal levels. The knockdown of Bcl-xL inhibited cell proliferation with cell accumulation at G2/M phase and the appearance of sub-G0/G1 peak in DNA flow cytometric assay. The suppression of cell growth was accompanied by an increase in the caspase-3/7 activity with the resultant cleavages of procaspase-3 and its substrate poly (ADP-ribose) polymerase, and increased percentage of apoptotic propensities in annexin V binding assay. Collectively, our data represent that the efficacy of resveratrol and clofarabine for apoptosis induction was substantially enhanced by Bcl-xL-lowering strategy in which the simultaneous targeting of Mcl-1 and Bcl-xL could be a more effective strategy for treating malignant mesothelioma.

Therapeutic effect of clofarabine in children with relapsed or refractory acute lymphoblastic leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the efficacy and adverse effects of clofarabine for relapsed/refractory acute lymphoblastic leukemia in children.</p><p><b>METHODS</b>Twenty-six pediatric patients with relapsed/refractory acute lymphoblastic leukemia were treated with clofarabine. There were 22 males and 4 females, with a mean age of 9.5 years (ranging from 4 to 17 years). They received clofarabine 52 mg/m2 intravenously over 2 hours daily for 5 days. Thirteen patients received two cycles and one patient received three cycles.</p><p><b>RESULTS</b>In the first cycle of clofarabine, complete remission was obtained in 11 children (42%) and partial remission was obtained in 7 children (27%). Eight children (31%) were considered unresponsive. In the second cycle, 11 (85%) of the 13 children obtained complete remission, 1 (8%) partial remission and 1 (8%) was unresponsive. One child received three cycles and obtained complete remission in each cycle. The common adverse events were myelosuppression, infection, liver dysfunction and gastrointestinal adverse reactions. There were no chemotherapy-related deaths.</p><p><b>CONCLUSIONS</b>Clofarabine is effective in the treatment of children with relapsed/refractory acute lymphoblastic leukemia and its adverse effects can be tolerated. Clofarabine could be a promising new treatment for relapsed/refractory acute lymphoblastic leukemia.</p>

Mechanism for clofarabine inducing autophagic death of acute myelocytic leukemia cell U937 / 中国实验血液学杂志

To explore the mechanism of autophagic death of acute myelocytic leukemia cell U937 induced by clofarabine, the MTT bioassay was used to analyze the growth inhibitory effect and half inhibition concentration on U937 incubated in vitro with different concentrations of clofarabine for 24 and 48 hours, and the flow cytometry was used to detect the autophagy rate of U937. The expression of Beclin 1 in U937 treated by clofarabine for 48h was measured by Western blot. The results indicated that when U937 cells were treated with 0.01 µmol/L and 0.15 µmol/L clofarabine for 48 hours, the proliferation inhibition rate was 46.92% ± 4.24% and 86.10% ± 1.16%, and the half inhibition concentration of clofarabine was 0.022 µmol/L. With 0.01 µmol/L and 0.1 µmol/L clofarabine on U937 for 48 hours, the autophagy rate was 11.0033% ± 1.4387% and 59.4133% ± 3.5409%, and increased in dose-dependent manner (r = 0.99). Meanwhile the Beclin 1 was upregulated along with increase of clofarabine concentration, as compared with control group, the difference was statistically significant (P < 0.05). It is concluded that the different concentrations of clofarabine can significantly inhibit the proliferation of U937 in dose-dependent manner, and the mechanism of autophagic cell death in U937 may be associated with the upregulation of Beclin 1 expression.

Clinical Outcome of IM-Guided Total Knee Arthroplasty with Inappropriate Femoral Resection in Coronal Plane

PURPOSE: The purpose of this study was to evaluate clinical results and accuracy of femoral cutting in the coronal plane in total knee arthroplasty (TKA) using a fixed length intramedullary guide. MATERIALS AND METHODS: From 2005 to 2008, 101 patients (154 knees) underwent TKA (NexGen LPS implant). The minimal follow-up period was 3 years (mean, 4.4 years). The patients were divided into two groups (group 1, 94alpha, 98 or =2degrees MAD was 65 in group 1 and 24 in group 2. The mean PTA, KSKS, and KSFS were 10.17degrees, 96.0, and 96.6, respectively, in group 1 and 11.58degrees, 84.5, and 85.5, respectively, in group 2. CONCLUSIONS: The percentage of coronal alignment outliers was relatively high (34 in 154 cases, 22%) after TKA using a fixed length intramedullary guide. However, there was no statistically significant intergroup difference in clinical results (KSKS, p=0.67; KSFS, p=0.56).

Assessment of Treatment Outcome after Using Temporary Mandibular Advancement Devices in Obstructive Sleep Apnea Patients

50% Apnea-Hypopnea Index (AHI) reduction plus post-MAD AHI <10, and the non-response group was defined as <50% AHI reduction. The lateral cephalogram was analysed including SNA, SNB, UL, MPH, PAS, PASU, and PAST using V-ceph(TM) (Cybermed, USA).RESULTS: The responsers were 23 patients, and non-responsers were 5 patients. The AHI was significantly reduced with temporary MAD (8.08+/-7.93) compared with baseline (28.51+/-20.56) in the response group (n=23). No significant difference was observed between pre MAD and post MAD except SNB on cephalometric analysis. Among 11 patients successfully treated with the temporary device, 9 patients said that using permanent device brings better effect too.CONCLUSION: These results indicate that the Temporary MAD could not be the only effective tools on OSA but also be used to predict patient's reactivity about permanent appliance treatment. Further studies are warranted to evaluate the relations between temporary MAD and permanent MAD.

Effect of clofarabine on proliferation and Bcl-2 expression of NB4 cells / 中国实验血液学杂志

The aim of this study was to observe the effect of clofarabine on proliferation of NB4 cells and its possible mechanism. MTT method was used to detect proliferation of NB4 cells treated with clofarabine 0.01 - 0.1 µmol/L for 48 h. The treated with clofarabine 0.01 - 0.1 µmol/L for 24 h, apoptosis rate and Bcl-2 expression of NB4 cells were measured by flow cytometry and Western blot respectively. The results showed that clofarabine inhibited proliferation of NB4 cells in a concentration-depended manner (r = 0.78). After treated with clofarabine for 24 h, apoptosis rate of NB4 cells increased and Bcl-2 expression in NB4 cells decreased obviously (P < 0.05). It is concluded that clofarabine inhibits proliferation of NB4 cells, which may be related with the down-regulation of Bcl-2 and induction of apoptosis.

The Influence of the Amount of Mandibular Advancement in the Application of Mandibular Advancement Device for Obstructive Sleep Apnea Patients / 수면정신생리

OBJECTIVES: The purposes of this study were to estimate the effect of mandibular advancement device (MAD) and to evaluate the influence of the advancement amount of mandible in the application of MAD for obstructive sleep apnea (OSA) patients. METHODS: From the patients who were diagnosed as OSA by polysomnographic study at Seoul National University Bundang Hospital from January 2007 to February 2009, the patients who chose MAD as treatment option were included in this study. All the patients' data including clinical records and polysomnographic studies (both pre- and post-treatment) were reviewed and analyzed. RESULTS: Successful results were obtained in 65 patients of 86 patients (75.6%). In the follow-up period, mild discomfort of anterior teeth or temporomandibular joint (TMJ) were described in 28 patients, especially in the cases the amount of mandibular advancement were more than 7.0 mm. There was no direct relationship between the amount of mandibular advancement and clinical outcome. CONCLUSION: MAD was effective treatment option for the OSA patients regardless of severity. For the prevention of potential dental complications, the amount of mandibular advancement should be considered at the time of MAD treatment.

Seated Postural Control in Elderly on Unstable Plate

OBJECTIVE: To investigate differences of the postural control in unstable sitting position between elderly and young adults. METHOD: Twenty five healthy elderly and twenty five healthy young adults were included. The evaluation system for postural control consisted of unstable plate, frame, safety harness, monitor and computer. Subjects sat on an unstable plate with arms crossed. Using two tilt sensor and postural control software in unstable platform measured the center of pressure (COP) of subject. COP sway (COP was maintained on the center circle and the distance from the central location for 30 sec) time and mean absolute deviation (MAD), COP maintaining (COP was maintained on the desired target in anterior, posterior, left or right directions during 30 sec) time and MAD, COP moving time (the time required to move the COP to desired target location away from center), COP sine curve maintaining (COP was maintained on the circle on moving sine curve during 30 sec) time and MAD were recorded in both groups. Each subject performed three trials and the mean value of the trials was used for analysis. RESULTS: In static evaluation, there was no significant difference in COP sway between two groups. In dynamic evaluations, elderly showed significantly decreased maintaining time in all four directions, decreased sine curve trace and increased moving time in all eight directions (p<0.001). CONCLUSION: Elderly revealed significantly impaired dynamic sitting postural control, regardless of directions. It might be related to decreased movement and proprioception of trunk.

Comparison of the Limb Alignment and the Component Positioning between Conventional and Navigated Total Knee Arthroplasties for the Osteoarthritic Knees That Have Anatomic Variation

PURPOSE: The authors sought to assess the usefulness of navigation as opposed to the conventional method by analyzing the radiographic results obtained from subjects who underwent total knee arthroplasty for knees that were accompanied with anatomic variations. MATERIALS AND METHODS: The study subjects were selected from 53 patients (a total 72 cases: 43 were treated by the conventional method and 29 were treated by the navigational method) who exhibited radiographic evidence of distal femoral varus (2degrees). The coronal femoral component angle (alpha) and the coronal tibial component angle (beta) were measured, and the femoral component position in relation to the mechanical axis (theta) and the post-operative weight-bearing mechanical axis difference (MAD) were compared and analyzed. RESULTS: The navigation method showed significant better results in terms of the alpha, theta and MAD (p<0.05). Among the outliers greater than 3degrees, a statistically significant difference was shown only for the MAD (p=0.030). CONCLUSION: Navigation surgery is useful in terms of the femoral component's position in the coronal plane and limb alignment in the osteoarthritic knee that is accompanied by distal femoral varus or proximal tibial varus.

Attitudes about Imported U.S. Beef in Relation to Human Mad Cow Disease in Participants of a Candlelight Rally / 신경정신의학

OBJECTIVES: This study was aimed to examine whether participants of a Korean candlelight rally had correct medical information about human mad cow disease and rational attitudes about imported U.S. beef in relation to human mad cow disease. METHODS: A total of 393 face-to-face interviews were conducted, and subjects completed questions about prevalence of senile dementia and human mad cow disease in U.S. and whether they will eat U.S. beef even if no cases of human mad cow disease occurred in the U.S. or if the chance of being affected with human mad cow disease was lower than dying in a plane crash. RESULTS: Correct answer rates to the questions about prevalence of senile dementia and human mad cow disease were 28.2% and 36.1%, respectively. A majority of respondents answered that they would not eat U.S. beef even if there were no reported cases of human mad cow disease in the U.S. or if their chance of being affected with human mad cow disease was lower than dying in a plane crash (75.6% and 86.0%, respectively). CONCLUSION: At least 64.4% of participants had incorrect medical information about human mad cow disease, and their attitudes about imported U.S. beef may be rooted in emotion rather than fact.

The relationship between uncoupling protein 2 expression and myocardial high energy phosphates content in abdominal aorta constriction induced heart failure rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the changes of expression of uncoupling protein 2 (UCP2) in pressure overload induced failure myocardium in rats.</p><p><b>METHODS</b>Male SD rats were randomized into 3 groups (n = 15 each): abdominal aorta constriction (AC) 20 weeks group (H20w group), sham operation group (SH20w group) and normal control group (N group). Twenty weeks later, myocardial function was evaluated by echocardiography and hemodynamic measurements. Mitochondria in ventricular tissue were isolated by centrifugation. Adenine nucleotide pools (ATP, ADP, AMP, PCr) in myocardium were measured by high performance liquid chromatography. The expression of UCP2 in mitochondria was detected by PT-PCR and Western blot analysis.</p><p><b>RESULTS</b>Myocardial function was significantly decreased 20 weeks post-AC compared to SH20w group and N group. Myocardial ATP, ADP, AMP and PCr contents were also significantly decreased in H20w group than the other 2 control groups. The expression of UCP2 in myocardial mitochondria was significantly increased in H20w group and negatively correlated with ATP contents (r = -0.929, P < 0.01).</p><p><b>CONCLUSIONS</b>The expression of UCP2 was upregulated in pressure overload induced failure heart and might be responsible for decreased myocardial adenine nucleotide and energy metabolism disturbance in this model.</p>

Serological Kinetics of Adenylate Kinase 3 in Rat Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: Currently used serological markers for the diagnosis of acute myocardial infarction differ in appearance time and specificity for myocardial infarction, allowing no ideal single serological marker for myocardial infarction. Adenylate kinase (AK) is a ubiquitous enzyme which contributes to the homeostasis of the cellular adenine nucleotides pool. AK is abundant in the myocardium, and we postulated that AK3 could be used as a biochemical marker for the diagnosis of acute myocardial infarction (AMI). MATERALS AND METHODS: We constructed an AMI rat model with ligation of the anterior descending artery. We measured the concentration of serum AK3 in the AMI rat model by enhanced chemiluminescence (ECL) sandwich ELISA using monoclonal antibodies against recombinant AK3. RESULTS: The serum AK3 level started to increase in 3 hours and reached a peak at 6 hours after ligation of the rat coronary artery. The significant elevation of AK3 was retained for 2 days (p<0.05). CONCLUSION: AK3 is a useful serological marker for acute myocardial infarction in the rat.

Ectonucleotidase activities in Sertoli cells from immature rats

Sertoli cells have been shown to be targets for extracellular purines such as ATP and adenosine. These purines evoke responses in Sertoli cells through two subtypes of purinoreceptors, P2Y2 and P A1. The signals to purinoreceptors are usually terminated by the action of ectonucleotidases. To demonstrate these enzymatic activities, we cultured rat Sertoli cells for four days and then used them for different assays. ATP, ADP and AMP hydrolysis was estimated by measuring the Pi released using a colorimetric method. Adenosine deaminase activity (EC 3.5.4.4) was determined by HPLC. The cells were not disrupted after 40 min of incubation and the enzymatic activities were considered to be ectocellularly localized. ATP and ADP hydrolysis was markedly increased by the addition of divalent cations to the reaction medium. A competition plot demonstrated that only one enzymatic site is responsible for the hydrolysis of ATP and ADP. This result indicates that the enzyme that acts on the degradation of tri- and diphosphate nucleosides on the surface of Sertoli cells is a true ATP diphosphohydrolase (EC 3.6.1.5) (specific activities of 113 + or - 6 and 21 + or - 2 nmol Pi mg-1 min-1 for ATP and ADP, respectively). The ecto-5'-nucleotidase (EC 3.1.3.5) and ectoadenosine deaminase activities (specific activities of 32 + or - 2 nmol Pi mg-1 min-1 for AMP and 1.52 + or - 0.13 nmol adenosine mg-1 min-1, respectively) were shown to be able to terminate the effects of purines and may be relevant for the physiological control of extracellular levels of nucleotides and nucleosides inside the seminiferous tubules

Effect of carnosine administration on certain metabolic parameters in Bilharzial infected hamsters

This study was designed to test the ability of carnosine to cure the metabolic disturbances induced by Schistosoma mansoni parasite. Results indicated that, parasitic infection caused elevation of liver weight/body weight of S. mansoni infected hamsters, induced lipid peroxidation and reduced glycogen level. Moreover, the adenylate energy charge [AEC], ATP/ADP and ATP/AMP concentration ratios were markedly lower in infected hamsters. Administration of carnosine [10 mg/day] for 15 days either concurrent with infection, two and four weeks post exposure was effective in reducing worm burden and egg count only when given at the time of infection. It was also effective in renormalizing most of the measured parameters confirming the glycogen repletion, the antioxidant and AEC correcting actions of carnosine

Biochemical alterations of the molluscan hosts tissues infected with schistosoma mansoni

As larval trematodes live within tissues of their molluscan hosts and indulge in asexual reproduction on a phenomenal scale, it is not surprising that snail tissues show biochemical changes. Levels of tissue glycogen, lactate, pyruvate and LDH[1] isoenzyme were measured in extracts of whole soft tissues of Biomphalaria alexandrina snails, specific molluscan hosts of Schistosoma mansoni. Moreover, assay of adenine nucleotides [ATP, ADP and AMP] and inorganic phosphate [Pi] was established to evaluate the adenylate energy charge [AEC] and the phosphate potential in trematode-infected snails. These parameters were measured in infected snails over four weeks, at weekly interval post exposure to S. mansoni miracidia and compared to age-matching non-exposed snails. The highest lactate/pyruvate concentration ratio with the lowest LDH[1], isoenzyme activity and glycogen level were observed two weeks post exposure. In addition, the lowest ATP content, ATP/ADP and ATP/AMP concentration ratios were also recorded at the same duration post exposure. The energy charge does not co-vary with ATP level but was slightly manipulated within the non-stressed range, while phosphate potential as a direct measure of oxygen consumption was significantly altered within 1[st], 2[nd] and 3[rd] weeks post exposure. This study clarify the most characteristic pattern of changes induced by the developing parasite. Moreover it reflects the need for an efficient glycolytic flux in the B.alexandrina snails to ensure survival and further development of S mansoni parasite

Effects of photofrin II and light on cellular adenine nucleotides and their modulation.

Effects of photofrin II (PII) and light on the intra cellular nucleotide levels have been investigated using BHK-21 cell line. Results indicate that lower concentrations of photofrin II in dark increases ATP levels in a non linear manner, however, there has been no change in energy charge and levels of other nucleotides. Photoirradiation of PII-treated cells leads to a significant reduction in ATP levels and energy charge along with an increase in ATP breakdown products like ADP and AMP. The phosphorylation potential [ATP]/[ADP][Pi] also reduces upon photoirradiation of PII treated cells. Incubation conditions like pH of the medium and temperature modulate the cellular responses to a great extent.