Erratum: Measurement of the 2νββ Decay Half-Life of ^{130}Te with CUORE [Phys. Rev. Lett. 126, 171801 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.126.171801.

Early Enteral Nutrition and Sepsis-Associated Acute Kidney Injury: A Propensity Score Matched Cohort Study Based on the MIMIC-III Database

PURPOSE

We aimed to analyze the optimal timing of enteral nutrition (EN) in the treatment of sepsis and its effect on sepsis-associated acute kidney injury (SA-AKI.).

MATERIALS AND METHODS

The MIMIC-III database was employed to identify patients with sepsis who had received EN. With AKI as the primary outcome variable, receiver operating characteristic (ROC) curves were utilized to calculate the optimal cut-off time of early EN (EEN). Propensity score matching (PSM) was employed to control confounding effects. Logistic regressions and propensity score-based inverse probability of treatment weighting were utilized to assess the robustness of our findings. Comparisons within the EEN group were performed.

RESULTS

2364 patients were included in our study. With 53 hours after intensive care units (ICU) admission as the cut-off time of EEN according to the ROC curve, 1212 patients were assigned to the EEN group and the other 1152 to the delayed EN group. The risk of SA-AKI was reduced in the EEN group (odds ratio 0.319, 95% confidence interval 0.245-0.413, p<0.001). The EEN patients received fewer volumes (mL) of intravenous fluid (IVF) during their ICU stay (3750 mL vs. 5513.23 mL, p<0.001). The mediating effect of IVF was significant (p<0.001 for the average causal mediation effect). No significant differences were found within the EEN group (0-48 hours vs. 48-53 hours), except that patients initiating EN within 48 hours spent fewer days in ICU and hospital.

CONCLUSION

EEN is associated with decreased risk of SA-AKI, and this beneficial effect may be proportionally mediated by IVF volume.

[Bibliometric and bioinformatics analysis of genetic literature on susceptibility to noise induced hearing loss]

Objective: To summarize and analyse of literature on the susceptibility genes of noise induced hearing loss (NIHL) , and the key genes were screened and obtained by bioinformatics method, so as to provide reference for the prevention research of NIHL. Methods: In September 2021, Based on CNKI, NCBI Pubmed database and Web of Science database, this paper conducted bibliometric analysis and bioinformatics analysis on the genetic literature related to the susceptibility to noise-induced hearing loss from 1999 to 2020. Endnote X9 software and the WPS office software were used for bibliometric analysis, and online software STRING and Cytoscape software were used for bioinformatics analysis. Results: A total of 131 literatures were included in the study, involving 40 genes in total. Bibliometric analysis shows that 131 papers which included 36 Chinese articles and 95 English articles were published in 63 biomedical journals; the highest number of published articles was 19 in 2020. Bioinformatics analysis suggests that GAPDH、SOD2、SOD1、CAT、CASP3、IL6 and other genes play a key role in the interaction network. The involved pathways mainly include MAP2K and MAPK activations, PTEN regulation, P53-depardent G1 DNA damage response, signaoling by BRAF and RAF fusions and soon. Conclusion: The study of noise induced hearing loss involves multi gene biological information, and bioinformatics analysis is helpful to predict the occurrence and development of noise induced hearing loss.

New Direct Limit on Neutrinoless Double Beta Decay Half-Life of ^{128}Te with CUORE

The Cryogenic Underground Observatory for Rare Events (CUORE) at Laboratori Nazionali del Gran Sasso of INFN in Italy is an experiment searching for neutrinoless double beta (0νββ) decay. Its main goal is to investigate this decay in ^{130}Te, but its ton-scale mass and low background make CUORE sensitive to other rare processes as well. In this Letter, we present our first results on the search for 0νββ decay of ^{128}Te, the Te isotope with the second highest natural isotopic abundance. We find no evidence for this decay, and using a Bayesian analysis we set a lower limit on the ^{128}Te 0νββ decay half-life of T_{1/2}>3.6×10^{24}  yr (90% CI). This represents the most stringent limit on the half-life of this isotope, improving by over a factor of 30 the previous direct search results, and exceeding those from geochemical experiments for the first time.

Improved Limit on Tensor Currents in the Weak Interaction from ^{8}Li β Decay

The electroweak interaction in the standard model is described by a pure vector-axial-vector structure, though any Lorentz-invariant component could contribute. In this Letter, we present the most precise measurement of tensor currents in the low-energy regime by examining the β-ν[over ¯] correlation of trapped ^{8}Li ions with the Beta-decay Paul Trap. We find a_{βν}=-0.3325±0.0013_{stat}±0.0019_{syst} at 1σ for the case of coupling to right-handed neutrinos (C_{T}=-C_{T}^{'}), which is consistent with the standard model prediction.

Pressure-Induced Superconductivity up to 9 K in the Quasi-One-Dimensional KMn_{6}Bi_{5}

The Mn-based superconductor is rare owing to the strong magnetic pair-breaking effect. Here we report on the discovery of pressure-induced superconductivity in KMn_{6}Bi_{5}, which becomes the first ternary Mn-based superconductor. At ambient pressure, the quasi-one-dimensional KMn_{6}Bi_{5} is an antiferromagnetic metal with T_{N}≈75  K. By measuring resistance and ac magnetic susceptibility under hydrostatic pressures up to 14.2 GPa in a cubic anvil cell apparatus, we find that its antiferromagnetic transition can be suppressed completely at a critical pressure of P_{c}≈13  GPa, around which bulk superconductivity emerges and displays a superconducting dome with the maximal T_{c}^{onset}=9.3  K achieved at about 14 GPa. The close proximity of superconductivity to a magnetic instability in the temperature-pressure phase diagram of KMn_{6}Bi_{5} and an unusually large μ_{0}H_{c2}(0) exceeding the Pauli paramagnetic limit suggests an unconventional magnetism-mediated paring mechanism. In contrast to the binary MnP, the flexibility of the crystal structure and chemical compositions in the ternary AMn_{6}Bi_{5} (A=alkali metal) can open a new avenue for finding more Mn-based superconductors.

Measurement of the 2νββ Decay Half-Life of ^{130}Te with CUORE

We measured two-neutrino double beta decay of ^{130}Te using an exposure of 300.7 kg yr accumulated with the CUORE detector. Using a Bayesian analysis to fit simulated spectra to experimental data, it was possible to disentangle all the major background sources and precisely measure the two-neutrino contribution. The half-life is in agreement with past measurements with a strongly reduced uncertainty: T_{1/2}^{2ν}=7.71_{-0.06}^{+0.08}(stat)_{-0.15}^{+0.12}(syst)×10^{20}  yr. This measurement is the most precise determination of the ^{130}Te 2νββ decay half-life to date.

[Targeted therapy of pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA): a case report and literature review]

Objective: To analyze the clinical course and targeted therapy of pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. Methods: The clinical history of a 6-year-old boy with PAPA syndrome, who was admitted to Hong Kong University Shenzhen Hospital in September 2017, was reviewed. His genetic diagnosis was confirmed by whole exome sequencing. The response to targeted therapy was evaluated by comparing the inflammatory markers (erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) and serum cytokines (interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α)) before and after biological agents treatment. For literature review, "PAPA syndrome" and"PSTPIP1 gene"were used as keywords to retrieve papers published from January 1997 to December 2019 from Pubmed, Wanfang and CNKI database. Results: The patient was a 6-year-old boy, admitted to the hospital due to recurrent joint swelling and pain for more than 4 years. Before treatment, the CRP (256 mg/L), ESR (105 mm/1 h) and cytokines including serum TNF-α (7.43 ng/L), IL-1 (<5 ng/L), IL-6 (301 ng/L) were significantly elevated. Culture of the joint effusion was negative, but the IL-6 level was above 1 000 ng/L. MRI showed osteomyelitis at the lower end of the right femur. Gene detection found a heterozygous variation of PSTPIP1 gene (c.748G>A, p.E250K). Arthralgia once alleviated after the initiation of tocilizumab and infliximab, but recurred after 1 year of treatment. Thereafter, the anti-IL-1 receptor antagonist (Anakinra) was commenced, followed by a significant improvement of the arthralgia, and a complete remission during the follow-up. Besides, the level of CRP, ESR, serum TNF-α, IL-1 and IL-6 were all decreased to normal on the last followed up in December 2019. Literature review found 29 articles and 87 patients in total. The initial symptoms included those of arthritis (n=58), pyoderma gangrenosum (n=33), and acne (n=24). Among all the cases, 13 genotypes were confirmed, and 47 variations involved amino acid p.E250. Steroid and/or biological agents were used in most patients. Conclusions: PAPA syndrome should be suspected in children with recurrent pyogenic sterile arthritis, and an early diagnosis could be achieved by genetic test. Targeted treatment with biological agent may control the symptoms effectively. Biological agents can control symptoms of this disorder effectively.

[Effect of silencing hepatocyte growth factor receptor c-Met expression on biological characteristics of colon cancer cells]

Objective: To investigate the effect of silencing hepatocyte growth factor receptor (c-Met) expression on the biological characteristics of HCT116 colon cancer cells. Methods: Cellular model of c-Met transient transfection was established by using small interfering RNA (siRNA), the expression of c-Met in colon cancer cells was detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and western blot. The apoptosis assay, cell invasion assay, cell migration and other experiments were conducted to observe the effects of silencing c-Met on the biological characteristics of colon cancer cells. Results: RT-qPCR results showed that the relative expression levels of c-Met mRNA in siRNA-Met group, blank control group and siRNA negative control (siRNA-NC) group were 0.32±0.26, 1.01±0.03 and 1.05±0.23, respectively, and the difference was statistically significant (P<0.05). Western blot analysis showed that the expression level of c-Met protein in the siRNA-Met group was 0.24±0.03, significantly lower than 1.23±0.06 in the blank control group and 1.18±0.11 in the siRNA-NC group (P<0.05). The cell counting kit-8 (CCK8) results showed that the 72-hour absorbance (A) values of the siRNA-Met group, blank control group and the siRNA-NC group were 1.13±0.05, 1.48±0.08 and 1.53±0.07, respectively, and the difference was statistically significant (P<0.01). Cell cycle results showed that the proportion of cells in G(2)/M phase was (14.65±1.41)% in siRNA-Met group , (5.07±0.70)% in blank control group and (5.63±0.71)% in siRNA-NC group, and the difference was statistically significant (P<0.05). The expression levels of cell cycle regulatory proteins Cdc25c and cyclin B1 in siRNA-Met group were significantly decreased. The apoptotic rate in siRNA-Met group was (5.85±0.35)%, significantly higher than (1.00±0.17)% in blank control group and (0.91±1.14)% in siRNA-NC group (P<0.05). The expression level of apoptosis-related protein Bcl-2 in the siRNA-Met group was significantly decreased while Bcl-2 associated X protein (BAX) expression level was significantly increased. The cell scratching result showed that the cell migration abilities of the siRNA-Met group, blank control group and the siRNA-NC group were (51.33±8.62)%, (100.00±3.72)% and (102.33±6.43)%, respectively, and the difference was statistically significant (P<0.05). The number of cell penetrating into the basement membrane of the siRNA-Met group, blank control group and the siRNA-NC group were 47.50±10.60, 100.00±5.33 and 102.50±10.61, respectively, and the difference was statistically significant (P<0.05). The expressions of invasion related proteins including MMP-2 and MMP-9 in siRNA-Met group were decreased significantly. Conclusions: c-Met plays an important role in maintaining the biological characteristics of colon cancer cells. Inhibition of c-Met may have important values in the treatment of colon cancer.

Improved Limit on Neutrinoless Double-Beta Decay in ^{130} Te with CUORE

We report new results from the search for neutrinoless double-beta decay in ^{130} Te with the CUORE detector. This search benefits from a fourfold increase in exposure, lower trigger thresholds, and analysis improvements relative to our previous results. We observe a background of (1.38±0.07)×10^{-2}  counts/(keV kg yr)) in the 0νββ decay region of interest and, with a total exposure of 372.5 kg yr, we attain a median exclusion sensitivity of 1.7×10^{25}  yr. We find no evidence for 0νββ decay and set a 90% credibility interval Bayesian lower limit of 3.2×10^{25}  yr on the ^{130} Te half-life for this process. In the hypothesis that 0νββ decay is mediated by light Majorana neutrinos, this results in an upper limit on the effective Majorana mass of 75-350 meV, depending on the nuclear matrix elements used.

[Expression of long-chain non-coding RNA LINC00152 in laryngeal squamous cell carcinoma and its clinical significance]

Objective:The aim of this study is to explore the relative expression level of LINC00152 in laryngeal squamous cell carcinoma（LSCC） and its clinical significance. Method:The relative expression levels of LINC00152 in LSCC cell lines and 36 paired LSCC specimens were measured by qRT-PCR method. And the correlations between the expression level of LINC00152 and the clinical features derived from LSCC patients were analyzed and compared through the independent sample t-test. Result:The relative expression level of LINC00152 was over-expressed in LSCC cell lines and cancerous tissues than that in paired adjacent normal tissues, and the difference was statistically significant（P=0.006）. Even the associations between LINC00152 expression level and clinicopathological features（P=0.044 for clinical stage, P=0.032 for pathological differentiation degree） were significantly. Conclusion:LINC00152 is highly expressed in LSCC and it may become a new tumor marker for the diagnosis and prognosis of LSCC.

Global transcriptome analysis provides new insights in Thellungiella salsuginea stress response

Thellungiella salsuginea is highly tolerant to abiotic stress, while its a close relative Arabidopsis thaliana is sensitive to stress. This characteristic makes T. salsuginea an excellent model for uncovering the mechanisms of abiotic stress tolerance. Abscisic acid (ABA) plays essential roles in plant abiotic and biotic stress tolerance. To test the changes in gene expression of T. salsuginea under ABA treatment, in this study, the transcriptomes of T. salsuginea roots and leaves were compared in response to exogenously application of ABA. The results showed that ABA treatment caused different expression of 2,200 and 3,305 genes in leaves and roots, respectively, compared with the untreated control. In particular, genes encoding transcription factors such as WRKY, MYB, NAC, GATA, ethylene-responsive factors (ERFs), heat stress transcription factors, basic helix-loop-helix, PLATZ and B3 domain-containing family members were enriched. In addition, 49 and 114 differentially expressed genes were identified as ABA-regulated genes, separately in leaves and roots, respectively, which were related to biotic and abiotic stresses. The expression levels of some genes were validated by qRT-PCR. Different responses of genes to ABA treatment were discovered in T. salsuginea and A. thaliana. This transcriptome analysis expands our understanding of the role of ABA in stress tolerance in T. salsuginea. Our study provides a wealth of information for improving stress tolerance in crop plants.

[Epidemiological characteristics of pesticide poisoning in Xuzhou city from 2005 to 2017]

Objective: To understand the characteristics and causes of pesticide poisoning in Xuzhou city, and provide basis for formulating prevention and control measures. Methods: The cases of pesticide poisoning in Xuzhou City from 2005 to 2017 were collected from "Pesticide Poisoning Report Card" . The data were analyzed and assessed by EpiData. The SPSS 22.0 software was used for statistical analysis. Results: During the thirteen years, there were a total of 8092 cases of pesticide poisoning, among which, the number of occupational pesticide poisoning was 1 408, accounting for 17.4% of the total number of cases, 14 patients died, the case fatality rate was 0.1%. There were 2, 992 cases of male poisoning, accounting for 36.97% of the total number of cases, and 5, 100 cases of female poisoning, accounting for 63.03%. There were 6684 non-productive pesticide poisonings, accounting for 82.6% of the total number of cases; 387 deaths occurred, and the mortality rate was 5.8%. Among non-productive poisonings, the incidence of oral pesticide poisoning was 84.3%, and the incidence of accidental poisoning by pesticides was 15.7%. Organophosphorus pesticides poisoning cases accounted for the majority of oral pesticide poisoning cases. The overall incidence of pesticide poisoning showed a downward trend. The age of non-productive pesticide poisoning cases was mainly 15-44 years old, and the number of cases of poisoning were 4 029 cases (60.28%) . With the increase of age, the mortality rate of poisoning cases was higher, especially for those over 60 years old who died of oral pesticide poisoning (40.1%) . The peak of pesticide poisoning began to increase in the second quarter and reached its peak in the third quarter. Conclusion: Although the cases of pesticide poisoning reported in Xuzhou City have been declining in recent years, the situation is still severe. The proportion of oral pesticide suicide accounts for a large proportion, and the mortality rate of elderly and female is relatively high, and the government should pay more attention. Workers should conduct safety education and psychological counseling to improve the knowledge and consciousness of safe use of pesticides.

Effect of pressure on the self-hole-doped superconductor RbGd2Fe4As4O2

RbGd₂Fe₄As₄O₂ is a newly discovered self-hole-doped stoichiometric superconductor, which has a hybrid structure with separated double FeAs layers and exhibits a high superconducting transition temperature T _c  =  35 K. Here, we report the effect of pressure (P) on its T _c and normal-state transport properties by measuring the temperature dependence of resistivity ρ(T) under various pressures up to 14 GPa with a cubic anvil cell apparatus. We found that the T _c is suppressed monotonically to ca. 12.5 K upon increasing pressure to 14 GPa with a slope change of T _c(P) at around 4 GPa. In addition, the low-temperature normal-state ρ(T), which is proportional to T ⁿ , also evolves gradually from a non-Fermi-liquid with n  =  1 at ambient pressure to a Fermi liquid with n  =  2 at P  ⩾  4 GPa. Accompanying with the non-Fermi-liquid to Fermi-liquid crossover, the quadratic temperature coefficient of resistivity, which reflects the effective mass of charge carriers, also experiences a significant reduction as commonly observed in the vicinity of a magnetic quantum critical point (QCP). Our results indicate that the stoichiometric RbGd₂Fe₄As₄O₂ at ambient pressure might be located near a QCP such that the enhanced critical spin fluctuations lead to high-T _c superconductivity. The application of pressure should broaden the electronic bandwidth and weaken the spin fluctuations, and then restore a Fermi-liquid ground state with lower T _c.

First Results from CUORE: A Search for Lepton Number Violation via 0νββ Decay of ^{130}Te

The CUORE experiment, a ton-scale cryogenic bolometer array, recently began operation at the Laboratori Nazionali del Gran Sasso in Italy. The array represents a significant advancement in this technology, and in this work we apply it for the first time to a high-sensitivity search for a lepton-number-violating process: ^{130}Te neutrinoless double-beta decay. Examining a total TeO_{2} exposure of 86.3 kg yr, characterized by an effective energy resolution of (7.7±0.5)  keV FWHM and a background in the region of interest of (0.014±0.002)  counts/(keV kg yr), we find no evidence for neutrinoless double-beta decay. Including systematic uncertainties, we place a lower limit on the decay half-life of T_{1/2}^{0ν}(^{130}Te)>1.3×10^{25}  yr (90% C.L.); the median statistical sensitivity of this search is 7.0×10^{24}  yr. Combining this result with those of two earlier experiments, Cuoricino and CUORE-0, we find T_{1/2}^{0ν}(^{130}Te)>1.5×10^{25}  yr (90% C.L.), which is the most stringent limit to date on this decay. Interpreting this result as a limit on the effective Majorana neutrino mass, we find m_{ββ}<(110-520)  meV, where the range reflects the nuclear matrix element estimates employed.

Effect of hydrostatic pressure on the superconducting properties of quasi-1D superconductor K2Cr3As3

K₂Cr₃As₃ is a newly discovered quasi-1D superconductor with a T _c  =  6.1 K and an upper critical field µ ₀ H _c2(0)  ≈  40 T three times larger than the Pauli paramagnetic limit µ ₀ H _p that is suggestive of a spin-triplet Cooper pairing. In this paper, we have investigated the effects of hydrostatic pressure on its T _c and µ ₀ H _c2 by measuring the ac magnetic susceptibility χ'(T) under magnetic fields at various hydrostatic pressures up to 7.5 GPa. The major findings include: (1) T _c is suppressed gradually to below 2 K at 7.5 GPa; (2) the estimated µ ₀ H _c2(0) decreases dramatically to below µ ₀ H _p above ~2 GPa and becomes slight lower than the orbital limiting field [Formula: see text] estimated from the initial slope of upper critical field via [Formula: see text]  =  -0.73T _cdH _c2/[Formula: see text] in the clean limit; (3) the estimated Maki parameter α  =  √2[Formula: see text]/H _p drops from 4 at ambient pressure to well below 1 at P  >  2 GPa, suggesting the crossover from Pauli paramagnetic limiting to orbital limiting in the pair breaking process upon increasing pressure. These observations suggested that the application of hydrostatic pressure could drive K₂Cr₃As₃ away from the ferromagnetic instability and lead to a breakdown of the spin-triplet pairing channel. We have also made a side-by-side comparison and discussed the distinct effects of chemical and physical pressures on the superconducting properties of K₂Cr₃As₃.

Critical behavior in tetragonal antiperovskite GeNFe3 with a frustrated ferromagnetic state

Tetragonal GeNFe₃ has a second-order ferromagnetic (FM) to paramagnetic transition at 76 K. Our integrated investigations indicate that the ground FM state is frustrated and the tetragonal symmetry is retained below 550 K based on the results of variable temperature X-ray diffraction. Critical behavior was analyzed by a systematic bulk magnetization study. The estimated critical exponents by three different methods (modified Arrott plot, the Kouvel-Fisher method, and critical isotherm analysis) conformably suggest that long-range magnetic coupling described by mean-field (MF) theoretical model is dominant in GeNFe₃. The experimental M-T-H data collapse into two independent branches according to the scaling equations m = f_±(h) with the renormalized magnetization m = ε^-βM(H, ε) and the magnetic field h = Hε^-(β+γ). The exchange distance is estimated as J(r) ∼ r^-4.8 on the basis of the β and γ values, which lies between the long-range MF model (r^-4.5) and the short-range 3D Heisenberg (3DH) model (r^-5). Our results indicate that the competition between local magnetic moments of iron 3d electronic state and itinerant covalent interactions of N-Fe bonds should be responsible for critical behavior in this system.

[Effect of Δ40p53 isoform on enhancing the pro-apoptotic function of p53 in tumor cells]

Objective: To investigate the effect of Δ40p53, an alternative spliced isoform of p53 lacking the N-ter minus, on the pro-apoptotic function of p53. Methods: The wild-type p53 was ectopically expressed in HCT116-p53(-/-) (endogenous Δ40p53 expression), HCT116-p53(+ /+) (wild-type p53) and H1299 (p53-null) cells by adenoviral delivery, while Δ40p53 plasmid were transfected into these cells to overexpress Δ40p53. The levels of Δ40p53 and p53 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR) and quantitative PCR. The expression of related proteins was deter mined by Western blotting. The interaction of p53 and Δ40p53 was observed by co-immunoprecipitation assay. Calcein-AM/propidium iodide (PI) staining and flow cytometry were used to detect the apoptotic rate of tested cells in each group. Results: HCT116-p53(-/-) cells expressed endogenous Δ40p53 isoform. Neither transcription nor protein expression of wild-type p53 was interfered by the increased expression of Δ40p53. Full length p53 and Δ40p53 could bind to each other. Calcein-AM/PI staining showed that the apoptotic rates of H1299-Control, HCT116-p53(-/-) -Control, H1299+ p53, HCT116-p53(-/-)+ p53, H1299+ oxaliplatin (Oxa), HCT116-p53(-/-)+ Oxa, H1299+ p53+ Oxa and HCT116-p53(-/-)+ p53+ Oxa groups were (2.50±0.47)%, (2.40±0.32)%, (5.20±0.58)%, (4.10±0.18)%, (22.40±1.73)%, (19.30±1.11)%, (29.90±1.15)% and (39.30±2.26)%, respectively. It was statistically significant between H1299+ p53+ Oxa and HCT116-p53(-/-)+ p53+ Oxa groups (t=3.721, P=0.0205). Moreover, the apoptotic rates of H1299-Control, H1299+ Δ40p53, H1299+ p53, H1299+ p53+ Δ40p53, H1299+ Oxa, H1299+ Δ40p53+ Oxa, H1299+ p53+ Oxa and H1299+ p53+ Δ40p53+ Oxa groups were (2.60±0.35)%, (2.20±0.17)%, (4.80±0.49)%, (4.90±1.10)%, (20.30±1.10)%, (19.60±1.45)%, (27.90±1.39)%, (35.20±1.43)%, respectively. Furthermore, flow cytometry assay showed that the apoptotic rates of above cells were (2.70±0.32)%, (2.20±0.24)%, (4.60±0.48)%, (3.90±0.67)%, (19.30±1.11)%, (17.70±0.66)%, (28.30±2.76)% and (37.50±1.51)%, respectively. H1299+ p53+ Δ40p53+ Oxa cells showed higher cell apoptosis than H1299+ p53+ Oxa cells (t=2.930, P=0.042). Conclusion: Δ40p53 isoform can bind to full-length p53, and enhance its pro-apoptotic function in tumor cells.

[Study on the survival rate of random flap using pre-injection of ADSCs]

Objective: To determine the effects of adipose-derived stem cells (ADSCs) on the survival rate of flaps by transplanting ADSCs into the experimental flaps pre-operatively. Methods: ADSCs were isolated from fresh human fat and cultured in vitro. Their morphological characters were observed, and flowcytometry and differentiation test and evaluation were conducted. A total of 40 BALB/c mice were divided into 5 groups randomly with each of 8 mice. 1 cm×4 cm random skin flap was designed on the mice back, ADSCs were injected in advance into subcutaneous tissues of 3 groups, the operation was performed on the 2^nd, 5^th and 7^th day after the ADSCs injection, meanwhile skin flap operation was conducted in the immediate injection group and control group. Survival condition of the skin flaps was observed and von willebrand factor (vWF) staining was used to detect the number of micro-vessels in the skin flap. The enzyme-linked immuno sorbent assay (ELISA) method was used to detect the concentration of vascular endothelial growth factor (VEGF) in the skin flap. Results: The immediate injection group had a significantly higher survival rate of skin flap than the pre-injection groups and the control group [(51.5±6.3)% vs (38.3±6.7)%, (21.0±2.9)%, (30.0±3.9)% and (34.5±4.2)%, all P<0.01]. The immediate injection group had a significantly higher number of micro-vessels in the skin flap than the pre-injection groups and the control group [(21.0±4.3) vs (17.5±3.9), (9.9±2.6), (13.9±2.6) and (16.1±3.3)/LPF, all P<0.01]. The laboratory results of the concentration of VEGF in skin flap kept a consistent tendency with the flap survival rate. Conclusion: Pre-injection with the ADSCs into the skin flap prevents the survival of the flap to a certain extend and does not show the function of promoting tissue angiogenesis.

Search for Neutrinoless Double-Beta Decay of (130)Te with CUORE-0

We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of (130)Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1±0.3  keV FWHM and 0.058±0.004(stat)±0.002(syst)counts/(keV kg yr), respectively. The median 90% C.L. lower-limit half-life sensitivity of the experiment is 2.9×10(24)  yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of (130)Te and place a Bayesian lower bound on the decay half-life, T(1/2)(0ν)>2.7×10(24)  yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of (130)Te from the Cuoricino experiment we obtain T(1/2)(0ν)>4.0×10(24)  yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, m(ββ)<270-760  meV.

Observation of the large magnetocaloric effect in an orbital-spin-coupled system MnV(2)O(4)

The magnetocaloric effect (MCE) in an orbital-spin-coupled spinel vanadate MnV(2)O(4) is investigated by magnetization measurement. MnV(2)O(4) has ferrimagnetic ordering occurring at T(C) = 57 K. The maximum magnetic entropy change reaches 14.8 and 24.0 J kg(-1) K(-1) for field changes of 0-2 and 0-4 T, respectively. The maximum adiabatic temperature is about 2.9 K for a magnetic field change of 2 T. Except for the spin entropy change, the observed giant MCE is suggested to be related to the orbital entropy change due to the change of the orbital state of V(3+) induced by an applied magnetic field around T(C).

Dichlorido(2,9-dimethyl-1,10-phenanthroline-κN,N')copper(II)

In the title compound, [CuCl₂(C₁₄H₁₂N₂)], the complex molecule has m symmetry, with the mirror plane oriented parallel to the planar molecule and the ligated Cu^II atom. The metal centre has a distorted tetra­hedral coordination formed by two N atoms from one 2,9-dimethyl-1,10-phenanthroline ligand and two Cl atoms. There is inter­molecular π–π stacking between adjacent 2,9-dimethyl-1,10-phenanthroline ligands, with a centroid–centroid distance of 3.733 (2)Å.

Body size and the risk of biliary tract cancer: a population-based study in China

Though obesity is an established risk factor for gall bladder cancer, its role in cancers of the extrahepatic bile ducts and ampulla of Vater is less clear, as also is the role of abdominal obesity. In a population-based case–control study of biliary tract cancer in Shanghai, China, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for biliary tract cancer in relation to anthropometric measures, including body mass index (BMI) at various ages and waist-to-hip ratio (WHR), adjusting for age, sex, and education. The study included 627 patients with biliary tract cancer (368 gall bladder, 191 bile duct, 68 ampulla of Vater) and 959 healthy subjects randomly selected from the population. A higher BMI at all ages, including early adulthood (ages 20–29 years), and a greater WHR were associated with an increased risk of gall bladder cancer. A high usual adult BMI (⩾25) was associated with a 1.6-fold risk of gall bladder cancer (95% CI 1.2–2.1, P for trend <0.001). Among subjects without gallstones, BMI was also positively associated with gall bladder cancer risk. Regardless of BMI levels, increasing WHR was associated with an excess risk of gall bladder cancer risk, with those having a high BMI (⩾25) and a high WHR (>0.90) having the highest risk of gall bladder cancer (OR=12.6, 95% CI 4.8–33.2), relative to those with a low BMI and WHR. We found no clear risk patterns for cancers of the bile duct and ampulla of Vater. These results suggest that both overall and abdominal obesity, including obesity in early adulthood, are associated with an increased risk of gall bladder cancer. The increasing prevalence of obesity and cholesterol stones in Shanghai seems at least partly responsible for the rising incidence of gall bladder cancer in Shanghai.

Intraductal papillary neoplasms of bile duct. A distinct entity like its counterpart in pancreas

To recognize the new entity-intraductal papillary neoplasia of bile duct in liver, the authors reviewed the clinical records of sixteen patients, analyzed the microscopic features, and selected immunohistochemical reactivity (cytokeratins and mucins) that might correlate with classification. Ten patients were male and six were female, with a mean age of 58 years (range, 21-73 years). According to their cell phenotypes, these papillary tumors were classified as intestinal type (6 cases), pancratobiliary type (4 cases), gastric type (5 cases) and oncocytic type (1 case). Most were located in the left hepatic duct and accompanied with bile duct dilatation (10 cases). Eight showed minimal expansile invasion into the ductal wall and eight were noninvasive. Five patients were treated with a hepatectomy, three underwent segmental resections, and one underwent a left hepatic lobectomy. One patient died of unrelated causes 6 years after operation, and another died of postoperative complications. The remaining 7 patients are alive and disease free 1-5 years after surgery. Because of its distinct clinical, pathological features and a favorable prognosis can be expected after complete surgical resection, we suggested that intraductal papillary neoplasia should be distinguished from other types of peripheral cholangiocarcinoma, as a distinct entity, like its counterparts in the pancreas. Neoexpressed and overexpressed mucins are of clinical value as a marker for supportive diagnosis, prognosis or monitoring therapy.

Establishment of a subcutaneous model of the human extrahepatic bile duct carcinoma in nude mice via transplantation of histologically intact tumor tissue

The purpose of the study was to establish the subcutaneous model of human extrahepatic bile duct carcinoma in nude mice so as to provide a suitable model for the study of extrahepatic bile duct carcinoma. Surgical specimens of the patient with extrahepatic bile duct carcinoma were transplanted into the subcutaneous layer of nude mice. Growth curve of transplanted tumors was drawn and its morphological and biological characteristics, as well as choromosome were observed. A well differentiated mucinous adenocarcinoma model of human bile duct carcinoma in nude mice, designated as HBDCM1-ZSH (Human Bile Duct Carcinoma Model No. 1 established by Zhong Shan Hospital in April, 2001), was established via subcutaneous transplantation of the surgically resected tumor from a 56-year-old Chinese man. HBDCM1-ZSH has been maintained for 13 passages and exhibited 98.1% transplantability. Mean latent periods were 26 days. Transplanted tumors exhibited the characteristics of the original tumor in morphology and biology. Chromosomal analysis revealed numerical abnormalities ranging from 67 to 84. HBDCM1-ZSH expressed carcinoembryonic antigen (CEA), carbohydrate antigen (CA)19-9, cytokeratin (CK7, CK19, CK20), PCNA, AB and PAS. In conclusion, HBDCM1-ZSH is similar to human extrahepatic bile duct carcinoma and provides an applicable animal model for research on extrahepatic bile duct carcinoma.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Selected peptide extension contacts hydrophobic patch on neighboring zinc finger and mediates dimerization on DNA

Protein-protein interactions often play a crucial role in stabilizing protein-DNA complexes and thus facilitate site-specific DNA recognition. We have worked to incorporate such protein-protein contacts into our design and selection strategies for short peptide extensions that promote cooperative binding of zinc finger proteins to DNA. We have determined the crystal structure of one of these fusion protein-DNA complexes. The selected peptide extension was found to mediate dimerization by reaching across the dyad axis and contacting a hydrophobic patch on the surface of the zinc finger bound to the adjacent DNA site. The peptide-zinc finger protein interactions observed in this structure are similar to those of some homeodomain heterodimers. We also find that the region of the zinc finger surface contacted by the selected peptide extension corresponds to surfaces that also make key interactions in the zinc finger proteins GLI and SWI5.

Beta-catenin mutations in biliary tract cancers: a population-based study in China

beta-Catenin is an ubiquitously expressed cytoplasmic protein that has a crucial role in both cadherin-mediated cell-cell adhesion and as a downstream signaling molecule in the wingless/Wnt pathway. Activating mutations in exon 3 of the beta-catenin gene, at the phosphorylation sites for ubiquitination and degradation of beta-catenin, are present in a variety of cancers. Because alterations of the adenomatous polyposis coli (APC) gene are present in biliary tract cancers and the APC protein modulates levels of beta-catenin, we evaluated the role of beta-catenin in biliary tract cancer by sequencing the third exon of the beta-catenin gene among 107 biliary tract cancers and 7 gallbladder adenomas from a population-based study in CHINA: Point mutations of serine or threonine phosphorylation sites in exon 3 of beta-catenin were present in 8 of 107 (7.5%) biliary tract cancers and 4 of 7 (57.1%) gallbladder adenomas. Mutations of beta-catenin were more frequent in ampullary and gallbladder carcinomas than in bile duct carcinomas (P = 0.04) and in papillary adenocarcinomas than other histological types of carcinomas (P = 0.02). These results suggest that the molecular pathways of biliary tract neoplasms vary by anatomical subsite and histological subtype.

An increase in free radical production by means of an anion channel blocker DIDS in mouse peritoneal neutrophils

DIDS (4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid) has been recognized as an anion channel blocker. In this study, we demonstrated that DIDS significantly enhanced the production of free radicals in mouse peritoneal neutrophils. By means of a luminol-chemiluminescence (LCL) monitoring system, DIDS markedly increased LCL which could be suppressed by SOD, sodium azide (NaN3), EGTA and BAPTA-AM and only slightly inhibited by staurosporine (STP). Depletion of the endoplasmic reticulum (ER)-Ca2+ store by means of thapsigargin (TG) had no effects on DIDS-enhanced LCL, but DIDS significantly increased the amount of intracellular free calcium as monitored by means of fura-2 staining. These results indicate that DIDS may enhance free radical production mediated by Ca2+ release from the mitochondria. Both phorbol-12-myristate-13-acetate (PMA) and DIDS can induce increased translocation of p47-phox of the neutrophil to the membrane fraction, which is inhibited by STP pretreatment. Since free radical generation could reduce the cytoplasmic pH (pHi), we further examined whether DIDS was capable of inducing intracellular acidification. The result indicated that DIDS certainly lowered the pHi which was also suppressed by pretreatment with either NaN3 or NaCN, but not by diphenyleneiodonium (DPI). These findings lead us to propose a working hypothesis that DIDS mainly induces superoxide production accompanied by decreasing pHi mediated through a Ca2+ -dependent effect on the mitochondria rather than on NADPH oxidase. Using the lipophilic fluorescent dye DiOC6(3), we showed that DIDS decreased the transitional mitochondrial membrane potential. NaN3, but not STP or pyrrolidine dithiocarbamate (PDTC), antagonized DIDS in the course of decreasing the mitochondrial membrane potential. Taken together, all of these findings imply a possible role of anion channels of the mitochondria in modulating free radical production and intracellular acidification of neutrophils through alteration of the mitochondrial transition membrane potential and Ca2+ -release.

Dimerization of zinc fingers mediated by peptides evolved in vitro from random sequences

Peptides that mediate dimerization of attached zinc finger DNA-binding domains have been evolved in vitro starting from random sequences. We first used phage display to select dimerization elements from libraries of random 15-residue polypeptides that were fused to the N terminus of the zinc finger domains. We then reoptimized these peptides by sequentially randomizing five-residue blocks (proceeding across the peptide in three steps) and selecting variant peptides that further stabilized the protein-DNA complex. Biochemical experiments confirmed that the selected peptides promote dimerization of the zinc fingers on an appropriate DNA target site. These results demonstrate that dimerization units can be obtained readily from random polypeptide libraries of moderate complexity. Our success reemphasizes the utility of searching random peptide libraries in protein design projects, and the sequences presented here may be useful when designing novel transcription factors.

Role of tyrosine kinase activity in 2,2',2''-tripyridine-induced nitricoxide generation in macrophages

In this paper, we demonstrated that 2,2',2"-tripyridine (TP, 1-20 microM) is a potent inducer of nitric oxide (NO) synthase in the cultured murine macrophage RAW 264.7 cell line. TP increased not only nitrite but also inducible NO synthase (iNOS) protein and mRNA production. Co-treatment with either NOS inhibitors (N(G)-monomethyl-L-arginine and aminoguanidine) or cycloheximide and actinomycin D all inhibited TP-induced nitrite production, indicating the requirement of protein and mRNA synthesis. The signaling pathway of TP-induced iNOS expression was explored, and the results obtained suggested that increased tyrosine kinase activity followed by inhibitor of nuclear factor for immunoglobulin kappa chain in B cells (IkappaB) degradation and then nuclear factor kappaB (NFkappaB) activation was involved in TP-induced iNOS expression. Tyrosine kinase inhibitors (e.g. genistein and tyrphostin AG126) inhibited both TP-induced nitrite and iNOS protein production. Whether the metalochelating property of TP was involved in these effects was explored by saturating TP with FeCl3. Although the ferrated TP became inactive, the specific iron chelator desferrioxamine, at a very high concentration of 400 microM, induced only a weak enhancement of nitrite production in this RAW cell line. It was thereby concluded that TP induces NO production through an increase in iNOS expression, which is initiated by a signaling pathway via tyrosine kinases leading to an activation of NFkappaB. Since TP is much more potent than desferrioxamine in increasing nitrite production, it is suspected that the primary event induced by TP was possibly mediated by TP's interacting with certain macromolecules in addition to its metal-chelating property.

Effects of dexamethasone, cyproheptadine, anisodamine, and dinoprostone on TNF alpha production in endotoxic shock

AIM

To study the effects of dexamethasone (Dex), cyproheptadine (Cyp), anisodamine (Ani), and dinoprostone (Din) on lipopolysaccharides (LPS)-induced tumor necrosis factor alpha (TNF alpha) gene expression and antishock effects of inhibiting TNF alpha production.

METHODS

Endotoxic shock in rats was produced by i.v. injection of LPS (E coli O111B4, 5 mg.kg-1). TNF alpha mRNA accumulation was assessed by Northern blot. Plasma TNF alpha contents were determined by radioimmunoassay.

RESULTS

The TNF alpha mRNA levels in rat liver at 2 h after LPS challenge was increased obviously (autoradiograms analyzed by scanning were 38 +/- 10 vs saline control 11 +/- 8, P < 0.01). The plasma TNF alpha contents were markedly increased [(22 +/- 3) micrograms.L-1 vs saline control (2.2 +/- 1.0) micrograms.L-1, P < 0.01]. Dex 5, Cyp 5, Ani 10, or Din 2 mg.kg-1 immediately injected after i.v. LPS markedly decreased the TNF alpha mRNA levels in rat liver and plasma TNF alpha contents. The Dex, Cyp, Ani, and Din improved the mouse survival rate 24 h after LPS 20 mg.kg-1 challenge.

CONCLUSION

Dex, Cyp, Ani, and Din strongly inhibit LPS-induced TNF alpha gene expression, and have a beneficial antishock effects.

Aetiologies and prognosis of Chinese patients with deep vein thrombosis of the lower extremities

Deep vein thrombosis (DVT) of the lower extremities is not frequently encountered in Oriental patients. We investigated its aetiology and prognosis in 143 patients (65 males, 78 females), presenting to the National Taiwan University Hospital over 4.3 years, diagnosed by colour Doppler ultrasonography. Swelling and pain of the lower extremities were the most frequent presenting symptoms. The left femoropopliteal veins were more frequently involved than other parts of the lower extremities. In these patients, malignancy with or without intravenous catheterization was the most frequent cause (39 patients, 27%). Other common aetiologies included coagulopathy (29 patients, 20%), immobilization (24 patients, 17%) and catheter-related (13 patients, 9%). No definite aetiology could be determined in 37 patients (26%). During follow-up, 27 patients (19%) died, mostly with malignancy. Pulmonary embolism was noted in 16 patients and was not significantly directly related to death. Compared to similar studies in Caucasian patients, there were significant differences in the aetiology of DVT, with malignancy and coagulopathy more common in these Chinese patients.

Augmentation of hormonal activities with antibodies from cattle immunized with a combination of synthetic and recombinant growth hormone peptide

Antibodies generated against a synthetic growth hormone (GH) peptide in a number of animal species were shown to enhance the efficacy of GH. However, the ability to produce the effective antibodies diminished over time and repeated boosters failed to overcome the hurdle. Therefore, this study was designed to address the issue on the failed antibody responses by employing different GH peptide antigen preparations in cattle. Holstein steers were repeatedly immunized with a synthetic peptide corresponding to an amino acid sequence 54-95 of porcine GH (pGH). The peptide was conjugated to ovalbumin (OVA) as a carrier. Animals initially responded to the antigen well and elicited antibodies specific to the peptide. However, the 4th challenge with the same OVA-peptide antigen rendered animals unresponsive, resulting in a decline in antibody production. This unresponsiveness was overcome by switching the antigen at the 5th immunization from OVA-peptide to a recombinant peptide preparation which was composed of maltose binding protein (MBP) as a carrier. Antibodies generated in cattle after the 5th immunization recognized not only the pGH(54-95) peptide, but also bovine GH (bGH) and pGH. These antibodies were not immunoreactive with an unrelated control peptide. Hypophysectomized (hypox) rats were used for functional analysis and bGH was active in promoting the growth of these GH-deficient rats. The growth-promoting effect of bGH was significantly enhanced by mixing it with bovine anti-peptide antibodies prior to administration. Therefore, the present findings suggest that peptide 54-95 induces cattle to elicit antibodies capable of not only recognizing bGH but also augmenting the somatogenic effectiveness of bGH in hypox rats.

Augmentation of hormonal activities with antibodies from cattle immunized with a combination of synthetic and recombinant growth hormone peptide

Antibodies generated against a synthetic growth hormone (GH) peptide in a number of animal species were shown to enhance the efficacy of GH. However, the ability to produce the effective antibodies diminished over the time and repeated boosters failed to overcome the hurdle. Therefore, this study was designed to address the issue on the fallen antibody responses by employing different GH peptide antigen preparations in cattle. Holstein steers were repeatedly immunized with a synthetic peptide corresponding to an amino acid sequence 54-95 of porcine GH (pGH). The peptide was conjugated to ovalbumin (OVA) as a carrier. Animals initially responded to the antigen well and elicited antibodies specific to the peptide. However, the 4th challenge with the same OVA-peptide antigen rendered animals unresponsive, resulting in a decline in antibody production. This unresponsiveness was overcome by switching the antigen at the 5th immunization from OVA-peptide to a recombinant peptide preparation which was composed of maltose binding protein (MBP) as a carrier. Antibodies generated in cattle after the 5th immunization recognized not only the pGH(54-95) peptide, but also bovine GH (bGH) and pGH. These antibodies were not immunoreactive with an unrelated control peptide. Hypophysectomized (hypox) rats were used for functional analysis and bGH was active in promoting the growth of these GH-deficient rats. The growth-promoting effect of bGH was significantly enhanced by mixing with bovine anti-peptide antibodies prior to administration. Therefore, the present findings suggest that peptide 54-95 induces cattle to elicit antibodies capable of not only recognizing bGH but also augmenting the somatogenic effectiveness of bGH in hypox rats.

Capacitative Ca2+ influx in glial cells is inhibited by glycolytic inhibitors

In non-excitable cells, stimulation of phosphoinositide (PI) turnover and inhibition of the endoplasmic reticulum (ER) Ca2+-ATPase are methods commonly used to deplete calcium stores, resulting in a capacitative Ca2+ influx (i.e., Ca2+ release-activated Ca2+ influx). Since this Ca2+ influx in glial cells has not been thoroughly investigated, we have used C6 glioma cells as a glial cell model to study this phenomenon. On adding cyclopiazonic acid (CPA) or thapsigargin (TG) (two ER Ca2+-ATPase inhibitors) in Ca2+-free medium, only a small transient increase in intracellular Ca2+ was seen. After depletion of the stored Ca2+, a marked Ca2+ influx, followed by a prolonged plateau, was seen on re-addition of extracellular Ca2+ ions (2 mM), i.e., capacitative Ca2+ influx. A similar effect was seen on adding ATP, known to deplete the inositol triphosphate (IP3)-sensitive Ca2+ store in C6 cells. After various degrees of store depletion, the amplitude of the capacitative Ca2+ influx was found to be highly dependent on the amount of Ca2+ remaining in the store. This Ca2+ influx was markedly inhibited by (1) La3+ and Ni2+, (2) SK&F 96365, econazole, and miconazole, and (3) membrane depolarization, clearly showing that this Ca2+ influx after store depletion in C6 cells is a capacitative mechanism. Interestingly, the capacitative Ca2+ influx can be inhibited by a reduction in intracellular ATP (ATPi) levels in glial cells. The role of ATPi in the capacitative Ca2+ influx is discussed.

Reduction of myocardial ischemia-reperfusion injury by isovolumic hemodilution

In order to study the effects of isovolumic hemodilution and its combination with Danshen solution on acute ischemic reperfused canine myocardium, 24 adult hybrid dogs were used and divided into four groups. Group I was the control group, groups II-IV were treated with Dextron 40, Danshen solution and a combination of the two, respectively. The results showed that either Dextron 40 or Danshen solution alone had a significant increase of +/- dp/dt-max when compared with group I (p < 0.05). Although no significant difference existed between group II and III, the former showed more rapid action. The combination of the two therapies improved +/- dp/dt-max and LVSP, and significantly reduced the necrotic sizes and the MDA contents in the ischemic myocardia compared with not only group I, but also group II or group III (all p < 0.05). The results suggest that isovolumic hemodilution or Danshen may protect the ischemic reperfused myocardium and the former may come into action more rapidly, and that the combination of the two may show a better synergism than each one of the two by itself.

Molecular interaction of growth hormone with two monoclonal antibodies recognizing distinct epitopes

Two monoclonal antibodies (mAb), designated PS-7.6 and PS-11.2, were generated against recombinant porcine growth hormone (pGH) and shown to enhance the hormonal activity in promoting the growth of animals. The mAb were compared and their functional relationship investigated. It was demonstrated by radioimmunoassay that PS-11.2 did not compete, but rather enhanced binding of 125I-pGH tracer to PS-7.6, suggesting that both mAb recognized distinct epitopes and also were additive in their antigen bindings. Surface plasmon resonance analysis using optical BIAcore technology (Pharmacia Biosensor, Piscataway NJ, USA) provided additional data to support this idea because pGH, after being captured by PS-11.2, remained capable of interacting with PS-7.6. An anti-idiotypic mAb was employed and shown to interact with PS-7.6 but not PS-11.2, implying that the differences in the Fab variable regions of these two mAb might contribute to their epitope specificity. Binding kinetics were determined by the BIAcore and the individual affinities of PS-7.6 and PS-11.2 to pGH were 6.8 x 10(-8) and 1.2 x 10(-9) mol/L, respectively. When these mAb were sequentially subjected to the BIAcore, however, their affinities decreased by approximately 100-fold. Therefore, binding of pGH with one mAb significantly impaired a subsequent interaction with another mAb despite the fact that both mAb targeted different epitopes. Hypophysectomized rats were used for functional analysis and pGH was active in promoting growth of these GH-deficient animals. The hormonal effect was further improved by incubating pGH with either PS-7.6 or PS-11.2 prior to administration. However, enhancement by individual mAb was completely abolished when pGH was treated with both mAb together, indicating their unpredictable biological interference with each other. Therefore, the present findings clearly demonstrate that although PS-7.6 and PS-11.2 recognize separate epitopes, their individual interactions with pGH are closely interrelated both immunologically and biologically.

Enhancement of the insulin antagonistic effect of porcine somatotropin in swine using a monoclonal antibody

A monoclonal antibody (mAb), PS-7.6, to porcine somatotropin (pST) significantly enhanced the growth responses to pST injections in hypophysectomized (hypox) rats but could not be tested in pigs because of the large quantity of antibody required for a growth trial. Because pST inhibits the hypoglycemic effects of insulin, an insulin tolerance test procedure was established to measure pST activity in jugular-catheterized pigs. Doses of 0, 30, 100, and 300 micrograms/kg per day of pST were split and administered subcutaneously (sc) in equal portions twice daily for 2 d. After a 17-hr fast, plasma samples were obtained at 10-min intervals for 30 min before an intravenous injection of insulin (0.08 IU/kg) and then for an additional 50 min. Because pST increased fasting plasma glucose concentrations, preinsulin glucose values were used as a covariate to adjust the postinsulin concentrations. pST caused a dose-dependent increase in resistance to the insulin injection in these pigs. The areas under the curves (AUC), for plasma glucose were 22.1, 29.0, 39.0, and 47.2 mg/dl per min for the 0, 30, 100, and 300 micrograms/kg pST doses, respectively. Because different doses of pST could be detected, the PS-7.6 enhancement of pST treatment was evaluated. In the first experiment, five pigs/group each received sc injections of either vehicle, pST (75 micrograms/kg; approximately 3.0 mg/d), pST (75 micrograms/kg) + PS-7.6 at 3.75 mg/kg, or pST (75 micrograms/kg) + PS-7.6 at 15 mg/kg for 2 d before the insulin test. The pST and PS-7.6 were combined and incubated for at least 1 hr at room temperature before being injected. The injection of pST alone did not significantly change insulin tolerance activity (23.1 vs. 21.1, AUC), but insulin resistance was enhanced when this dose of pST also included PS-7.6 (27.4 and 29.5, AUC, respectively; P < 0.05). In a second experiment, the effects of PS-7.6 and PS-4.2, a mAb that did not potentiate the pST-stimulated growth of hypox rats, were compared. The five pigs/treatment received either vehicle, pST (75 micrograms/kg), pST (75 micrograms/kg) + PS-7.6 (3.75 mg/kg), or pST (75 micrograms/kg) + PS-4.2 (3.75 mg/kg) for 2 d. The administration of pST increased the resistance to insulin (26.7 vs. 18.8, AUC; P < 0.01), which was markedly potentiated by PS-7.6 (54.3, AUC, P < 0.001) but not affected by PS-4.2 (27.6 AUC). The injection of PS-7.6 at 7.5 mg/kg without exogenous pST did not alter the sensitivity to insulin. These results indicate that PS-7.6, but not PS-4.2, enhanced the insulin antagonistic activity of pST in swine, suggesting that an enhancement of pST-stimulated growth would also occur in PS-7.6-treated pigs.

Functional characterization of monoclonal antibodies specific to growth hormone receptor

Upon engagement with appropriate ligands, receptors can be activated to initiate various metabolic and morphological changes in living cells. An attempt was made in this study to generate monoclonal antibodies (mAb) specific to recombinant rat growth hormone receptor (GHR) and subsequently to investigate their ability to act as biologically active ligands. Three mAbs, designated 1A9, 1H2 and 2C3, were produced and all were highly reactive with GHR in an enzyme-linked immunosorbent assay. In contrast to 1H2, 1A9 and 2C3 competed with radioactive growth hormone (GH) tracer for the binding to GHR in a radioreceptor assay, suggesting that the GH-binding sites of GHR were identical, or very close to its epitopes recognized by 1A9 and 2C3. The molecular interaction evaluated by the BIAcore technology further demonstrated the separate GHR epitopes for 1A9 and 2C3. 2C3 apparently targeted the precise GH-binding sites of GHR, while the antigenic determinants for 1A9 were not at the site, but adjacent to it. Functional analysis showed that 2C3 promoted the growth of hypophysectomized rats, whereas others failed to do so. Therefore, findings from the present study suggest that these mAbs recognize distinct GHR epitopes and are useful for investigating the structure-function relationship of GHR. Furthermore, 2C3 may prove important as a biologically active agonist for better understanding of the process of GHR activation relevant to growth.

Immunological effect of a synthetic growth hormone peptide on the growth performance in swine

A mouse monoclonal antibody (mAb), designated PS-7.6, was previously shown to enhance the activity of porcine growth hormone (pGH) in promoting the growth of hypophysectomized (hypox) rats. Epitope mapping studies indicated that the region recognized by PS-7.6 resided within an amino acid sequence 54-95 of pGH. A peptide corresponding to this sequence was synthesized and found to induce swine antibodies capable of augmenting pGH activity in hypox rats. On the basis of these previous observations, an attempt was made in this study to determine whether or not the peptide pGH(54-95) could be used as a vaccine to elicit antibodies functionally similar to PS-7.6 mAb, thus potentiating the efficacy of endogenous GH in swine. Young pigs (15-20 kg) were immunized with pGH(54-95) that had been conjugated with ovalbumin (OVA) and boosted twice at 4-week intervals. Control animals were similarly immunized with OVA. The weight gains and feed consumption of these animals were closely monitored throughout the trials. A number of carcass parameters were also examined when these animals reached 110-120 kg, at which time they were killed. Results indicated that immunization with peptide significantly accelerated the daily weight gain during the growing phase of growth. However, this effect disappeared during the finishing phase of growth. The failure to prolong the initial growth effect by the peptide immunization apparently correlated with the kinetics of antibody production, because antibodies immunoreactive to the peptide and pGH were detected in these animals after immunization but gradually diminished. This idea was supported by the fact that antibodies obtained from pigs 5 and 9 weeks after the initial immunization potentiated the activity of pGH in hypox rats, whereas antibodies harvested at week 16 did not. Furthermore, carcass evaluation was performed at time of killing and showed that the leaf fat and loin eye muscle were also significantly improved by peptide immunization. Taken together, the present findings suggest that pGH(54-95) peptide can be employed as a potential growth-promoting vaccine to improve the performance of swine.

Mechanism of hydrogen peroxide and hydroxyl free radical-induced intracellular acidification in cultured rat cardiac myoblasts

After a transient ischemic attack of the cardiac vascular system, reactive oxygen-derived free radicals, including the superoxide (O2-.) and hydroxyl (.OH) radicals can be easily produced during reperfusion. These free radicals have been suggested to be responsible for reperfusion-induced cardiac stunning and reperfusion-induced arrhythmia. Hydrogen peroxide (H2O2) is often used as an experimental source of oxygen-derived free radicals. Using freshly dissociated single rat cardiac myocytes and the rat cardiac myoblast cell line, H9c2, we have shown, for the first time, that an intriguing pHiota acidification (approximately 0.24 pH unit) is induced by the addition of 100 micromol/L H2O2 and that this dose is without effect on the intracellular free Ca2+ levels or viability of the cells. Using H9c2 as a model cardiac cell, we have shown that it is the intracellular production of .OH, and not O2-. or H2O2, that results in this acidification. We have excluded any involvement of (1) the three known cardiac pHi regulators (the Na+-H+ exchanger, the Cl--HCO3 exchanger, and the Na+-HCO3 co-transporter), (2) a rise in intracellular Ca2+ levels, and (3) inhibition of oxidative phosphorylation. However, we have found that H2O2-induced acidosis is due to inhibition of the glycolytic pathway, with hydrolysis of intracellular ATP and the resultant intracellular acidification. In cardiac muscle and in skinned cardiac muscle fiber, it has been shown that a small intracellular acidification may severely inhibit contractility. Therefore, the sustained pHi decrease caused by hydroxyl radicals may contribute, in some part, to the well-documented impairment of cardiac mechanical function (ie, reperfusion cardiac stunning) seen during reperfusion ischemia.

Promotion of animal growth with a monoclonal antibody specific to growth hormone receptor

A monoclonal antibody (mAb), designated 2C3, was raised against the growth hormone receptor (GHR) of rats. In a radioimmunoassay, 2C3 was found to compete with iodinated porcine GH (pGH) tracer for the binding to GHR, suggesting that GHR binding sites for pGH and 2C3 were identical or closely adjacent. The competition curve generated by 2C3 was identical to that generated by cold pGH, suggesting that the binding affinities of 2C3 and pGH to GHR were very similar. Administration of hypophysectomized rats with 2C3 resulted in the growth of these GH-deficient animals for a long period of time, mimicking the somatogenic effect of GH. However, this effect was abolished when 2C3 was injected into animals in the presence of exogenous GHR. A control mAb recognizing a GHR epitope distal from its binding site for GH failed to produce the growth in rats. Taken together, findings from the present study indicate that 2C3 is fully capable of engaging with GHR and subsequently triggering the growth response in rats. This mAb may also prove useful as a biologically active agonist for better understanding the initiation of the physiological process of GHR.

Epitope mapping and analysis of a growth-enhancing monoclonal antibody by limited tryptic digestion of porcine GH

In this study, the epitope of a murine PS-7.6 monoclonal antibody (mAb) which was raised against the recombinant porcine GH (pGH) and subsequently shown to enhance the growth-promoting activity of pGH in a hypophysectomized rat model, was mapped by the limited tryptic digestion of pGH. A pGH fragment corresponding to amino acid residues 70-95 was separated by reverse-phase HPLC and also immunoprecipitated by PS-7.6 mAb. This fragment was found in an RIA to compete with radiolabelled pGH for the binding of PS-7.6 mAb in a dose-dependent fashion. Several peptides covering this potential epitope region of pGH(70-95) were synthesized and assayed by competitive RIA. The results suggested that pGH(75-90) was the optimal sequence recognized by PS-7.6 mAb. Sequential alanine substitution of each residue of pGH(75-90) revealed that the side chains of Leu76, Ile83 and Leu87 were critical for binding to PS-7.6 mAb. Other residues could be replaced by alanine without substantially altering the binding affinity. The region of amino acids 75-95 comprises the C-terminal end of the second helix of pGH and the repeating pattern of i and i + 3 (i + 7) of the critical amino acids appears consistent with PS-7.6 mAb binding to the hydrophobic side of the helix. The sequence and the helical structure of the epitope of PS-7.6 mAb provide the basis for designing the effective peptide vaccines to enhance the growth performance of animals.

Augmentation of the effectiveness of porcine GH with swine antibodies induced by a synthetic GH peptide

An effort was made to evaluate the potential usefulness of a peptide vaccine in improving the growth performance of farm animals. It was previously reported that a murine PS-7.6 monoclonal antibody (mAb) which was specific to porcine GH (pGH) enhanced the growth-promoting activity of pGH in an experimental hypophysectomized rat model. Additional data from a epitope mapping study suggested that PS-7.6 mAb recognized a pGH fragment corresponding to an amino acid sequence 54-95. In this report, therefore, a peptide pGH(54-95) was synthesized in an attempt to induce PS-7.6-like antibodies in swine. It was demonstrated that the peptide pGH(54-95) competed with PS-7.6 mAb for the binding to radioactive pGH in a competition radioimmunoassay and also caused pigs to elicit polyclonal antibodies immunoreactive to pGH protein. The association and dissociation rate constants of the swine antibody to pGH were 1.9 x 10(2) M-1 s-1 and 3.2 x 10(-4)s-1 respectively, thus producing an overall binding affinity of Kd = 1.6 x 10(-6) M. The swine antibody partially competed with murine PS-7.6 mAb for the binding to pGH, suggesting that the pGH-recognizing sites for both antibodies might be closely related. The biological effect of the swine antibody was examined in hypophysectomized rats and shown to significantly augment pGH activity in promoting the growth of these GH-deficient animals. The present findings suggest that a synthetic peptide may be developed as a potential growth vaccine for swine to generate antibodies capable of enhancing the effectiveness of endogenous pGH.