PIK3CA as an oncogene in cervical cancer

Amplification of chromosome arm 3q is the most consistent aberration in cervical cancer, and is implicated in the progression of dysplastic uterine cervical cells into invasive cancer. The present study employed the 'positional candidate gene' strategy to determine the contribution of PIK3CA, which is located in 3q26.3, in cervical tumorigenesis. PIK3CA is known to be involved in the PI 3-kinase/AKT signaling pathway, which plays an important role in regulating cell growth and apoptosis. The results of comparative genomic hybridization show that the 3q26.3 amplification was the most consistent chromosomal aberration in primary tissues of cervical carcinoma, and a positive correlation between an increased copy number of PIK3CA (detected by competitive PCR) and 3q26.3 amplification was found in tumor tissues and in cervical cancer cell lines. In cervical cancer cell lines harboring amplified PIK3CA, the expression of gene product (p110alpha) of PIK3CA was increased, and was subsequently associated with high kinase activity. In addition, transformation phenotypes in these lines, including increased cell growth and decreased apoptosis, were found to be significantly affected by the treatment of specific PI 3-kinase inhibitor, suggesting that increased expression of PIK3CA in cervical cancer may result in promoting cell proliferation and reducing apoptosis. These evidences support that PIK3CA is an oncogene in cervical cancer and PIK3CA amplification may be linked to cervical tumorigenesis. Oncogene (2000).

Reserpine impairs spatial working memory performance in monkeys: reversal by the alpha 2-adrenergic agonist clonidine

Repeated daily treatment with the catecholamine-depleting agent, reserpine, dramatically reduced performance on the delayed response task, a test of spatial working memory that depends upon the integrity of the prefrontal cortex. Delayed response performance fell from an average of 27.2/30 trials correct before reserpine treatment to an average of 20.4/30 trials correct after repeated reserpine administration. Injection of the alpha 2-adrenergic agonist, clonidine (0.0001-0.05 mg/kg), to chronic reserpine-treated monkeys significantly restored performance on the delayed response task; performance after an optimal dose averaged 27.8/30 trials correct. Clonidine's beneficial effects on delayed response performance were longlasting; monkeys remained improved for more than 24 h after a single clonidine injection. The finding that clonidine is efficacious in reserpinized animals supports the hypothesis that alpha 2-adrenergic agonists improve cognitive function through actions at postsynaptic, alpha 2-adrenergic receptors on non-adrenergic cells. In contrast to the delayed response task, reserpine had little effect on performance of a visual discrimination task, a reference memory task which does not depend on the prefrontal cortex. These results emphasize the importance of postsynaptic, alpha 2-adrenergic mechanisms in the regulation of working memory.

Protein composition of microparticles shed from human placenta during placental perfusion: Potential role in angiogenesis and fibrinolysis in preeclampsia

Shedding of syncytiotrophoblast microparticles (MPs) from placenta to maternal blood occurs in normal pregnancy and is enhanced during preeclampsia (PE). The syncytiotrophoblast synthesizes plasminogen activator inhibitors (PAIs) which regulate fibrinolysis, as well as soluble forms of the fms-like tyrosine kinase (sFlt-1) and endoglin, which exert anti-angiogenic actions. An increase in the ratio of PAI-1/PAI-2 and elevated levels of sFlt-1 and sEng in maternal serum are linked to placental damage and maternal endothelial cell dysfunction in PE. The goal of the current study was to determine whether MPs released to maternal perfusate during dual perfusion contain these factors associated with placental pathophysiology in PE. Initially, high levels of alkaline phosphatase activity and Annexin V binding were found in MPs isolated by sequential centrifugation of maternal perfusates at 10,000 and 150,000×g(10 K and 150 K MPs), indicating their plasma membrane origin. ELISA revealed the presence of these factors at the following relative levels: Eng>PAI-2⋙PAI-1>sFlt-1. Based on comparisons of their concentration in perfusates, MPs, and MP-free 150 K supernatants, we determined that MPs constitute a significant portion of Eng released by placenta. Flow cytometric analysis of 10 K MPs supported the levels of expression found by ELISA and indicated that Eng and PAI-2 were almost exclusively localized to the surface of MPs, a site with biological potential. These results indicate that MPs shed from the syncytial surface express factors which may alter the fibrinolytic and angiogenic balance at the maternal-fetal interface and play a role in the pathophysiology of PE.

Proton/peptide cotransporter (PEPT 2) from human kidney: functional characterization and chromosomal localization

We report here on the functional characterization of the H+/peptide cotransporter PEPT 2 cloned from human kidney and on the chromosomal localization of the PEPT 2 gene. PEPT 2, when functionally expressed in HeLa cells, induces the transport of the neutral dipeptide glycylsarcosine. The induced transport activity is markedly influenced by extracellular pH. The optimum pH for the transport process is 6.0-7.0. Kinetic analysis has revealed that PEPT 2 is a high-affinity transporter, the Michaelis-Menten constant for glycylsarcosine being 74 +/- 14 microM. The human intestinal H+/peptide cotransporter PEPT 1 has 4-fold less affinity for the dipeptide under identical experimental conditions. Studies with other chemically diverse dipeptides have established that PEPT 2 possesses higher affinity than PEPT 1 not only for neutral peptides but also for peptides consisting of anionic and/or cationic amino acids. Somatic cell hybrid analysis and in situ hybridization have shown that the gene encoding PEPT 2 maps to human chromosome 3q13.3-q21.

A thyroid hormone receptor coactivator negatively regulated by the retinoblastoma protein

The retinoblastoma protein (Rb) plays a critical role in cell proliferation, differentiation, and development. To decipher the mechanism of Rb function at the molecular level, we have systematically characterized a number of Rb-interacting proteins, among which is the clone C5 described here, which encodes a protein of 1,978 amino acids with an estimated molecular mass of 230 kDa. The corresponding gene was assigned to chromosome 14q31, the same region where genetic alterations have been associated with several abnormalities of thyroid hormone response. The protein uses two distinct regions to bind Rb and thyroid hormone receptor (TR), respectively, and thus was named Trip230. Trip230 binds to Rb independently of thyroid hormone while it forms a complex with TR in a thyroid hormone-dependent manner. Ectopic expression of the protein Trip230 in cells, but not a mutant form that does not bind to TR, enhances specifically TR-dependent transcriptional activity. Coexpression of wild-type Rb, but not mutant Rb that fails to bind to Trip230, inhibits such activity. These results not only identify a coactivator molecule that modulates TR activity, but also uncover a role for Rb in a pathway that responds to thyroid hormone.

Temporo-frontal disconnection impairs visual-visual paired association learning but not configural learning in Macaca monkeys

Cynomolgus monkeys were tested in two computer-controlled visual associative memory tasks. The monkeys chose between visual objects on a screen by touching one. In the configural learning task one correct object and one wrong object were presented in each trial. Each of these two objects was composed of two coloured alphanumeric characters abutted together. The designation of the objects as 'correct' or 'wrong' followed a configural rule: e.g. if AB and CD are correct objects then AD and CB are wrong. In the paired association learning task in each trial three spatially separate objects (single alphanumeric characters) were presented. The central object was an instruction cue and the designation of the side objects as 'correct' or 'wrong' choices followed a paired association rule: e.g. if A, C and B are presented (C in the centre) then A is correct and B is wrong; however, if A, D and C are presented then C is correct and A is wrong. Disrupting the direct cortico-cortical interaction between the inferior temporal cortex and the prefrontal cortex by uncinate fascicle transection led to a learning deficit in the paired association task but not in the configural task. These results suggest that the uncinate fascicle facilitates visual-visual associative learning only in the specific case where a visual object acts as an instruction cue to guide the conditional choice of another, spatially separate object, and they support the evidence for a specific role of the uncinate fascicle in the learning of conditional tasks with visual instruction cues.

Characterization of the human type 2 neuropeptide Y receptor gene (NPY2R) and localization to the chromosome 4q region containing the type 1 neuropeptide Y receptor gene

Neuropeptide Y (NPY) signals through a family of G-protein-coupled receptors present in the brain and sympathetic neurons. To further our understanding of the genetic elements involved in the regulation of NPY receptor expression, we have cloned and characterized the human gene encoding the type 2 NPY receptor (Y2 receptor, HGMW-approved symbol NPY2R).2 The transcript spans 9 kb of genomic sequence and is encoded on two exons. As in the type 1 NPY receptor (Y1 receptor) gene, the 5'-untranslated region of the Y2 receptor is interrupted by an intervening sequence ( approximately 4.5 kb). However, the Y2 receptor gene does not contain an intron analogous to that present in the coding region of the Y1 receptor. The predicted transcript size ( approximately 4.5 kb) is consistent with the size observed by Northern analysis. The 381-amino-acid sequence deduced from the open reading frame is identical to that encoded by the cDNA. The Y2 receptor gene maps to human chromosome 4q31, the same region containing the Y1 receptor locus, suggesting that these subtypes may have arisen by gene duplication despite their structural differences.

Ketamine affects memory consolidation: Differential effects in T-maze and passive avoidance paradigms in mice

The effects of ketamine, an N-methyl-D-aspartate (NMDA) antagonist, on memory in animals have been limited to the sub-anesthetic dose given prior to training in previous studies. We evaluated the effects of post-training anesthetic doses of ketamine to selectively manipulate memory consolidation, and the effect of pre-retention sub-anesthetic doses of ketamine on memory retrieval in passive avoidance and T-maze tasks in mice. Repeated post-training anesthetic doses of ketamine impaired the consolidation of memory in the T-maze but not in passive avoidance paradigms. This impairment was not permanent but diminished 1-2 days after ketamine withdrawal. Sub-anesthetic post-training doses of ketamine (5 mg/kg) had no effect on memory consolidation, and larger doses (10, 20 and 50 mg/kg) did not influence the retrieval of memory in the T-maze. The data suggest that repeated anesthetic doses of ketamine block NMDA receptors and affect memory consolidation. Moreover, NMDA mechanisms antagonized by ketamine appear to be selectively involved in spatial (T-maze) memory mechanisms but may not be necessary for non-spatial (passive avoidance) memory consolidation.

Assignment of the human folate transporter gene to chromosome 21q22.3 by somatic cell hybrid analysis and in situ hybridization

We have used the human folate transporter cDNA and a human genomic clone hybridizing to the cDNA to perform chromosomal mapping of the folate transporter gene. Human-rodent somatic cell hybrid analysis using the cDNA as the probe revealed perfect segregation with human chromosome 21. In situ hybridization of the cDNA probe to human metaphase chromosome spreads mapped the folate transporter gene to the distal long arm of chromosome 21, band q22.3. This chromosomal location was confirmed by fluorescence in situ hybridization using the genomic clone.

β-catenin (CTNNB1) mutations are not associated with prognosis in advanced hepatocellular carcinoma

OBJECTIVES

Mutation of the exon 3 of CTNNB1, the coding gene of β-catenin, is a crucial molecular mechanism leading to aberrant activation of the Wnt/β-catenin pathway, which is highly associated with the carcinogenesis of hepatocellular carcinoma (HCC). The prevalence and clinical significance of CTNNB1 mutations in advanced HCC remain unclear.

METHODS

Patients with advanced HCC and available pathologic tissues (either obtained when diagnosed at advanced or early stages) were enrolled in this study. Direct sequencing of exon 3 of CTNNB1 was performed to detect somatic mutations. The associations between CTNNB1 mutations and clinicopathologic features were analyzed.

RESULTS

A total of 115 patients were enrolled, among whom 78 (67.8%) had chronic hepatitis B virus infection. Twenty-one (18.3%) patients were found to have CTNNB1 mutations, all of which were missense mutations. The CTNNB1 mutation rates were similar among pathologic tissues obtained at advanced and early stages (17.5 and 20.0%, respectively). Patients aged over 60 years were more likely to have CTNNB1 mutations than patients younger than 60 years (32.6 vs. 8.7%, p = 0.001). The mutations were not associated with survival or other clinicopathologic features.

CONCLUSION

In patients with advanced HCC, CTNNB1 mutations were not prognostically significant. No apparent increase of CTNNB1 mutations occurred during the progression of HCC.

AKR1B10, a good prognostic indicator in gastric cancer

BACKGROUND AND OBJECTIVES

The aim of the study was to investigate the correlation between AKR1B10 expression and clinicopathological features of gastric cancer (GC).

METHODS

Real-time polymerase chain reaction (RT-PCR) was performed to determine AKR1B10 mRNA expression. AKR1B10 protein levels were measured by immunohistochemistry.

RESULTS

RT-PCR analysis confirmed that AKR1B10 was significantly down-regulated in gastric cancer compared with paired, normal mucosa. Immunohistochemistry revealed that the percentage of AKR1B10-positive specimens was lower in gastric carcinoma compared with normal specimens. The frequency of AKR1B10-positive GC specimens was higher in patients with tumor size <5 cm, no lymph node metastasis, no distant metastasis and lower tumor stages The mean survival time for patients in the AKR1B10-positive group was significantly higher compared with the AKR1B1-negative group. The 5-year survival rate for the AKR1B10-positive group was also significantly higher than for the AKR1B1-negative group. Cox regression analysis revealed that AKR1B10 expression is an independent prognostic factor of GC.

CONCLUSIONS

Expression of AKR1B10 in gastric cancer was significantly associated with tumor size, lymph node metastasis, distance metastasis and TNM stage, and AKR1B10 may be a good prognostic indicator in gastric cancer.

Retrograde lymphatic spread: a likely route for metastatic ovarian cancers of gastrointestinal origin

In order to outline the pathways of gastrointestinal malignancies metastasizing to the ovaries, we reviewed 103 cases of metastatic ovarian tumors, and also performed para-aortic lymph node sampling on 11 patients at operation for metastatic ovarian tumors. Of the 103 patients, 74% (26/35) with gastric cancer and 67% (45/67) with colorectal cancer had lymph node metastasis at or before the diagnosis of ovarian tumor. Intraperitoneal metastases presented in 49 and 42% of patients with gastric and with colorectal cancers, respectively. Twenty-three percent of gastric cancer patients and 25% of colorectal cancer patients presented with both lymph node and intraperitoneal metastases. The ovary was the first or among the early metastatic organs diagnosed in 51 of the 53 patients with metachronous ovarian metastases. Only 4 patients with colorectal cancer and none with gastric cancer showed parenchymal organ metastases. These 4 patients also showed intraperitoneal lesions, and 3 of these 4 patients had node metastasis. Among the 11 patients who underwent prospective para-aortic lymph node sampling during operation for the ovarian tumors, only 1 had enlarged para-aortic nodes depicted by computed tomography, 2 had grossly enlarged (>/=1.5 cm) para-aortic lymph nodes noted at surgery, and 6 of the 7 patients with gastric cancer and all 3 with colorectal cancer had metastatic nodes histologically. Among the 58 nodes taken from these patients, 67% showed metastatic foci. We concluded that lymph node metastasis is frequently seen in patients with metastatic ovarian tumors of gastrointestinal origin, and hypothesized that retrograde lymphatic spread is a likely route for the metastases.

Role of hypoxia-inducible transcription factors 1alpha and 2alpha in the regulation of plasminogen activator inhibitor-1 expression in a human trophoblast cell line

The plasminogen activator inhibitors (PAIs) play critical roles in regulating hemostatic and invasive functions of trophoblasts through suppression of plasmin-dependent fibrinolysis and extracellular matrix degradation. The expression of PAI-1 is increased under hypoxic conditions, although the mechanism remains incompletely understood. In the current study we used HTR-8/SVneo cells, a first trimester extravillous trophoblast cell line, and siRNA technology to examine the role of hypoxia-inducible transcription factors (HIFs)-1alpha and -2alpha in the regulation of PAI-1 expression. Using serum-containing and serum-free media culture media it was initially noted that levels of PAI-1, but not PAI-2 protein, were markedly induced by hypoxic (2-3% oxygen) treatment. Under hypoxic conditions, Western blotting revealed that the presence of siRNAs to HIF-1alpha and HIF-2alpha suppressed expression of their respective proteins, whereas treatment with non-targeting and cyclophilin B siRNAs did not. Importantly, incubation with siRNA to HIF-1alpha or HIF-2alpha alone reduced PAI-1 protein levels to a similar extent, with the combined treatment inducing a more profound effect. The presence of HIF siRNAs reduced levels of PAI-1 mRNA as measured by quantitative real-time PCR, indicating that HIF-1alpha and HIF-2 alpha regulate PAI-1 expression at a transcriptional level. These results indicate that both HIF-1alpha and HIF-2alpha play important and similar roles in hypoxia-mediated stimulation of PAI-1 expression in HTR-8/SVneo cells. Our findings provide insight into the physiological regulation of trophoblast PAI-1 expression in early pregnancy when placental oxygen levels are low, as well as a mechanism for over-expression of placental PAI-1 noted in pregnancies with preeclampsia.

Genomic deletion and p53 inactivation in cervical carcinoma

The tumor-suppressor gene p53 acts as "the guardian of the genome", sensing DNA damage and initiating protective responses. To examine the hypothesis that p53 abnormality leads to increased genomic alterations in primary tumor cells, our study utilized 51 primary tumors of cervical carcinoma and 10 microsatellite markers. These markers were mapped to the short arms of chromosomes 3 and 5, covering the regions 3p13-25 and 5p15.1-15.3. Genomic deletion on 3p and 5p was correlated with genetic or epigenetic p53 inactivation pathways, including p53 mutation, genetic deletion of p53 and cervical infection with human papillomavirus. The proportion of abnormal p53 was found to be significantly higher in the cases exhibiting loss of heterozygosity (LOH) on 5p (p < 0.001), supporting the hypothesis of the presence of a p53-dependent pathway to cervical tumorigenesis. In contrast, however, LOH on 3p was found to be independent of p53 inactivation. A common deletion region, 3p22-24, was identified in 44% of informative cases, and genomic loss at this specific region was correlated with early tumorigenic onset and poor grade of tumor differentiation. Diversity within the patterns of genomic alteration in the same form of cancer suggests different sets of risk/tumorigenic profiles, molecular pathogenesis, as well as prognosis and outcome.

The effects of aging on the strength of surround suppression of receptive field of V1 cells in monkeys

The surround suppression of the receptive field is important for basic visual information processing, such as orientation specificity. To date, the effects of aging on the strength of surround suppression are not clear. To address this issue, we carried out extracellular single-unit studies of the receptive field properties of cells in the primary visual cortex (area V1) in young and old rhesus (Macaca mulatta) monkeys. When presented with the oriented central stimulus, we found that cells in old animals showed reduced orientation and direction selectivity compared with those in young animals. When presented with the oriented central stimulus together with the optimal surround stimulus, more selective cells {orientation bias (OB) >/=0.1; a bias of 0.1 is significant at the P<0.005 level} in animals of both ages showed reduced orientation selectivity compared with the experiment that presented only the oriented central stimulus. When presented with the optimal central stimulus together with the oriented surround stimulus, cells in old animals showed reduced orientation and direction selectivity compared with young animals. Moreover, broadly tuned cells (OB<0.1) in old animals exhibited significantly reduced suppression indices that quantified the strength of the surround suppression of the receptive field, when compared with those in young animals. These results suggest that aging may seriously affect the surround suppression of the receptive field of V1 cells. Thus, the decreased strength of surround suppression of the receptive field may be one possible reason for the decreased stimulus selectivity of V1 cells previously found in the senescent brain. This work will contribute to an understanding of the physiological mechanisms mediating surround suppression of the receptive field.

Monkeys can associate visual stimuli with reward delayed by 1 s even after perirhinal cortex ablation, uncinate fascicle section or amygdalectomy

In the present experiment monkeys learned concurrent associations of two-dimensional objects (presented on a computer screen) with delayed reward. Hypothetical mechanisms of associative memory, such as long-term potentiation (LTP), required coincidental activation of two population of neurons: one representing the object and the other signalling the reward. In monkeys neurons in area TE of temporal cortex show object-specific activity during object presentation but only fraction of those neurons remain active after stimulus offset. In a delayed reward condition the majority of object-specific neurons in TE cease firing before reward is given and can be detected. In the present study the rate of learning with 1000 ms delay of reward was no slower than learning with immediate reward. This indicates that information about the object is somehow retained across the delay, possibly somewhere outside TE. In the present study we tested that assumption. Area TE projects to the perirhinal cortex and, via uncinate fascicle, to the prefrontal cortex. In our hands, ablations of perirhinal cortex or disconnection of prefrontal cortex from TE (by transection of uncinate fascicle) did not impair learning with delayed reward. Ablation of amygdala, a structure involved in reward-learning, slowed down learning equally with and without delay. We conclude that retaining information about the visually perceived objects across a delay does not exclusively depend upon integrity of perirhinal cortex, or uncinate fascicle, or amygdala. Parallel involvement of those structures remains a possibility and establishment of the role of residual activity of TE neurons requires further neurophysiological investigation.

The characteristics of the pressure waves generated in the soft target by impact and its contribution to indirect bone fractures

When a high-velocity spherical fragment impacts a biological body, it will initiate strong pressure waves spreading throughout the body. A pressure wave, especially a shock wave with a steep front, generated by impact, may cause blood vessel injuries, viscera injuries, and indirect bone fractures. This paper reports research on pressure waves near the wound tracks, generated by spherical fragments, and calculates the zones of indirect bone fractures generated by pressure waves of impact.

Synchronous cancers of the esophagus and the ampulla of Vater after distal gastrectomy: successful removal of the esophagus, gastric remnant, duodenum, and pancreatic head

A case of synchronous squamous cell carcinoma of the esophagus and adenocarcinoma of the ampulla of Vater after previous gastrectomy is presented. The coexistence of these two lesions has never been reported in the English literature. We performed a subtotal esophagectomy, total residual gastrectomy, and pancreaticoduodenectomy with lymph node dissection in a one-stage procedure. An operation of this magnitude could be safely performed with attention to meticulous surgical technique and intensive postoperative care. Histological examination of the ampulla lesion showed adenocarcinoma with Paneth-cell differentiation. This is a rare lesion, and a review of the literature revealed only one other case. Neoplastic Paneth cells were also found in lymph node metastasis that originated from the ampulla tumor. This case confirms that cells with Paneth-cell differentiation can be a significant component in invasive carcinoma.

Observation of a fast electron beam emitted along the surface of a target irradiated by intense femtosecond laser pulses

A novel fast electron beam emitting along the surface of a target irradiated by intense laser pulses is observed. The beam is found to appear only when the plasma density scale length is small. Numerical simulations reveal that the electron beam is formed due to the confinement of the surface quasistatic electromagnetic fields. The results are of interest for potential applications of fast electron beams and deep understanding of the cone-target physics in the fast ignition related experiments.

The luminescence properties of Bi(3+) sensitized Gd2MoO6:RE(3+) (RE=Eu or Sm) phosphors for solar spectral conversion

Gd2MoO6:RE(3+) (RE=Eu or Sm) and Gd2MoO6:Bi(3+), RE(3+) (RE=Eu or Sm) phosphors have been synthesized by combustion method. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), photoluminescence excitation (PLE) and photoluminescence (PL) spectra. By introducing Bi(3+) ions into Gd2MoO6:RE(3+) (RE=Eu or Sm) phosphors, the excitation bands of Eu(3+) and Sm(3+) ions are broadened and shifted to short wavelength, meanwhile, the emission intensity are enhanced obviously. The energy transfer from Bi(3+) to the activators of Eu(3+) or Sm(3+) is observed and discussed. In addition, the process of ultraviolet light (250-400nm) converted into visible light can be achieved by using Gd2MoO6:Bi(3+), RE(3+) (RE=Eu or Sm) phosphor. These phosphors can be a promising ultraviolet-absorbing luminescent converter to enhance the photoelectrical conversion efficiency of dye-sensitized solar cells (DSSCs).

Gut-derived endotoxemia and multiple system organ failure following gunshot wounds combined with hemorrhagic shock: an experimental study in the dog

The purpose of this study was to explore the causative effects of high-velocity bullet injury (5.56 mm, 930 m/sec) combined with hemorrhagic shock on gut-derived endotoxemia and multiple system organ dysfunction or failure. The concentration of endotoxin in both portal and systemic blood was markedly increased after gunshot wounds together with hemorrhagic shock (p < 0.05-0.01). The portal/systemic lipopolysaccharide ratio persistently decreased in the combined wound (CW) group at 24 to 72 hours after injury, and it was much lower in the CW group than that in the single gunshot wound (SW) group. Also, a significant increase of fecal endotoxin content was found in the CW group as compared to the SW group (118.30 +/- 75.36 vs. 8.89 +/- 3.32 micrograms/g, p < 0.01), which was paralleled with the population of gram-negative bacilli in the intestinal tract. The incidence of multiple system organ failure, multiorgan dysfunction (including single organ failure) in the CW group were 30.8% (4 of 13) and 38.5% (5 of 13), respectively. These results suggested that severe trauma could lead to gut origin endotoxemia and bacterial translocation, which might play an important role in the pathogenesis of sepsis and multiple system organ failure following gunshot wounds.

Wounding properties of steel pellets with different velocities and quality on soft tissue of dogs

The characteristics of the soft-tissue wounds of the hind legs of 155 dogs produced by stainless steel spheres with four different masses and at various impact velocities were observed. It was found that when the mass of the spheres was identical, the velocity became the main factor to determine the severity of the damage; when the mass of the spheres was different but their kinetic energy was similar, then a smaller but faster sphere produced more severe damage than a larger but slower one. Shallow but wide and severe wounds usually resulted. The rate of disability of extremities with such wounds was very high. These wounding properties of steel spheres have caused some new problems in the treatment of war injuries.

Technetium-99m-tetrofosmin would be a substrate for multidrug resistance-associated protein (MRP): comparison between a leukemia cell line with high MRP gene expression and its parental cell line

The kinetics of cellular accumulation and retention of technetium-99m-tetrofosmin (99mTc-TF) were investigated in wild type HL60/WT cell line and in its doxorubicin-resistant HL60/DOX cell line with multidrug resistance-associated protein (MRP), but without P-gp overexpression, to determine whether 99mTc-TF is a substrate for MRP.

METHODS

The accumulation and washout of 99mTc-TF were observed in both cell lines at 37 degrees C. The effect of verapamil on the kinetics was also assessed.

RESULTS

99mTc-TF net accumulation was significantly lower in HL60/DOX (1.35 +/- 0.23%) than in HL60/WT (12.79 +/- 0.47%) at 60 min (P < 0.001). Three minutes after exchanging the incubation solution to the tracer-free medium, only 18.20 +/- 0.34% of 99mTc-TF remained in HL60/DOX, whereas 84.74 +/- 0.65% did in HL60/WT (P < 0.001). In the presence of 10 microM verapamil, 99mTc-TF net accumulation in HL60/DOX was 302% of the control and the washout was significantly delayed.

CONCLUSION

99mTc-TF would be a substrate for MRP and 99mTc-TF may be used as a functional imaging agent of MRP in vivo.

Bi3+ sensitized Y2WO6:Ln3+ (Ln=Dy, Eu, and Sm) phosphors for solar spectral conversion

The phosphors of Y2WO6:Bi3+, Ln3+ (Ln=Dy, Eu and Sm) were synthesized by solid-state reaction in this study. The crystal structure, photoluminescence properties and energy transfer mechanism were investigated. By introducing Bi3+ ions, the excitation band of the phosphors was broadened to be 250-380 nm, which could be absorbed by the dye-sensitized solar cells (DSSCs). The overlap between excitation of W-O groups/Bi3+ and the emission of Ln3+ (Dy, Eu, and Sm) indicated that the probability of energy transfer from W-O groups and Bi3+ to Ln3+. The energy transfer efficiency from Bi3+ to Ln3+ (Ln=Dy, Eu and Sm) are calculated to be 16%, 20% and 58%. This work suggested that Y2WO6:Bi3+, Ln3+ (Ln=Dy, Eu and Sm) might be a promising ultraviolet-absorbing luminescent converter to enhance the photoelectrical conversion efficiency of dye-sensitized solar cells (DSSCs).

Simultaneous removal of aqueous Zn2+, Cu2+, Cd2+, and Pb2+ by zeolites synthesized from low-calcium and high-calcium fly ash

In this study, zeolites were synthesized from low-calcium (LCZ) and high-calcium (HCZ) fly ash, respectively. Subsequently, the zeolites were tested for their removal effectiveness for four aqueous cations, namely, Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺, as a function of contact time, pH value, adsorbent dosage, and initial concentration of heavy metals. Both zeolites were characterized by X-ray diffraction, X-ray fluorescence spectrometry, scanning electron microscopy, specific surface area, and cation exchange capacity. The results show that HCZ mainly consists of an unnamed zeolite (Na₆[AlSiO₄]₆·4H₂O), whereas LCZ mainly consists of faujasite-type zeolite. The optimum sorption conditions were pH = 6.0; adsorbent dosage = 1.0 g·L^-1; temperature = 25 °C; contact time = 100 min; and initial heavy metal concentration = 100 mg·L^-1. The sorption kinetics of the four aqueous cations on both LCZ and HCZ followed the pseudo-second-order kinetic model, and the sorption isotherm data fitted well with the Langmuir isotherm model. For LCZ, the maximum adsorption capacities of Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺ were 155.76, 197.86, 123.76, and 186.22 mg·g^-1, respectively. For HCZ, the values were 154.08, 183.15, 118.91, and 191.94 mg·g^-1, respectively. The zeolites were regenerated by NaCl solution (1 mol·L^-1) and showed high removal efficiency. In conclusion, zeolites produced by fly ash are promising materials for removing Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺ from wastewater.