Research on inhibitive behaviors of electrolysis on the growth of Microcystis aeruginosa

Electrochemical method using a novel Ti/RuO2 anode was employed to inhibit a typical cyanobacteria, Microcystis aeruginosa (M. aeruginosa) under different electrolytic conditions. It is demonstrated that Ti/RuO2 anode was more efficient than traditional graphite anode in M. aeruginosa inhibition. The experimental results showed that the higher current density or longer electrolytic time could effectively improve the inhibition of M. aeruginosa. In addition, sodium chloride was a more effective electrolyte than sodium sulfate to enhance inhibition. The maximum inhibiting rate dose to 100% could be obtained at a current density of 12 mA cm(-2) when sodium chloride was used as a supporting electrolyte. Furthermore, UV-Visible spectra demonstrated that the structures of phycocyanins and chlorophyll a (Chl a) in M. aeruginosa could be changed or destroyed during electrolysis. Moreover, EPR spectra showed the generation of the free radicals through electrolysis, which might be one of the reasons responsible for the inhibition of algal growth.

Difference in expression level and localization of DNA polymerase beta among human esophageal cancer focus, adjacent and corresponding normal tissues

The aim of this paper was to study the expression level and localization of DNA polymerase beta (polbeta) and the difference in those among the human esophageal cancer focus, cancer adjacent and corresponding normal esophageal tissues. These three kinds of tissues were collected from surgically resected tissues in 17 patients with esophageal carcinoma in Linzhou, China. Each of a total of 51 tissue pieces was divided into two aliquots: one aliquot for detection of polbeta expression by in situ hybridization and by immunohistochemistry; another for detection of polbeta expression by RNA dot blot and immunoblotting. In the tissue specimens detected by in situ hybridization and immunohistochemistry, the cancer focus tissue had much stronger polbeta expression signals localized in the scattered heteromorphologic cancer cells. The cancer adjacent tissue exhibited slightly stronger polbeta signals mainly localized in the epithelial proliferating cells and the corresponding normal tissue displayed weak polbeta signals basically located in the epithelial basal cells. The difference in expression level of polbeta among the three kinds of tissues detected by RNA dot blot and immunoblotting was similar to the above results. Further, the truncated POLB could be demonstrated in both cancer focus and cancer adjacent tissues, but could not be found in the corresponding normal tissue in immunoblotting. The results suggest that the overexpression of polbeta with truncated form may be a potential biomarker for early diagnosis of human esophageal carcinoma.

Praseodymium Hydroxide and Oxide Nanorods and Au/Pr6O11 Nanorod Catalysts for CO Oxidation

Praseodymium hydroxide nanorods were synthesized by a two-step approach: First, metallic praseodymium was used to form praseodymium chloride, which reacted subsequently with KOH solution to produce praseodymium hydroxide. In the second step the hydroxide was treated with a concentrated alkaline solution at 180 degrees C for 45 h, yielding nanorods as shown by the scanning and transmission electron microscopy images. The results of X-ray diffraction and energy-dispersive X-ray spectroscopy experiments indicate that these nanorods are pure praseodymium hydroxide with a hexagonal structure, which can be converted into praseodymium oxide (Pr6O11) nanorods of a face-centered cubic structure after calcination at 600 degrees C for 2 h in air. Gold was loaded on the praseodymium oxide nanorods using HAuCl4 as the gold source, and NaBH4 was used to reduce the gold species to metallic nanoparticles with sizes of 8-12 nm on the nanorod surface. These Au/Pr6O11 nanorods exhibit superior catalytic activity for CO oxidation.

Multiple intracranial aneurysms as delayed complication of atrial myxoma. Case report and literature review

SUMMARY

We report a case of multiple intracranial aneurysms as delayed complication of atrial myxoma.We reviewed the literature of intracranial myxomal aneurysms, and trying to find reasonable therapy methods, but got the conclusion that neurosurgery and interventional treatment were not helpful, chemotherapy and radiotherapy maybe useful in the treatment of such cases.

A rat model of chronic allograft liver rejection

INTRODUCTION

The aim of this study was to develop a rat model of chronic irreversible rejection, which is a major causes of late graft loss and retransplantation after orthotopic liver allotransplantation.

METHODS

Allogeneic liver transplantation was performed in a rat combination of Dark Agouti (DA) to Brown Norway (BN). Group A was left without treatment, group B received cyclosporine' (CsA; 1 mg/kg/d) and group C, CsA (4 mg/kg/d). Animals were followed for 6 months. Liver tissue was harvested to construct a time course of histological changes after liver transplantation using histopathological and morphometric techniques. We compared the total histological score of rejection activity index and survival rates.

RESULTS

In untreated animals, irreversible acute rejection developed, all animals died within 15 days. In the low-dose CsA group, all animals that survived more than 30 days developed moderate to severe manifestations of chronic liver rejection, with graft infiltration, ductular damage or proliferation, obliterative arteriopathy, and liver fibrosis. No apparent histological alterations were observed in group C. Survival analysis showed significant differences between the three groups.

CONCLUSIONS

In the rat strain combination of DA --> BN with low-dose immunosuppression, early mild inflammation was followed by the development of chronic rejection.

Bonding configurations and collective patterns of Ge atoms adsorbed on Si(111)-(7 x 7)

We report scanning tunneling microscopy observations of Ge deposited on the Si(111)-(7 x 7) surface for a sequence of submonolayer coverages. We demonstrate that Ge atoms replace so-called Si adatoms. Initially, the replacements are random, but distinct patterns emerge and evolve with increasing coverage, until small islands begin to form. Corner adatom sites in the faulted half unit cells are preferred. First-principles density functional calculations find that adatom substitution competes energetically with a high-coordination bridge site, but atoms occupying the latter sites are highly mobile. Thus, the observed structures are indeed more thermodynamically stable.

Detection of BCL2-IGH Using Single-Round PCR Assays

The translocation t(14;18) resulting in fusion of the BCL2 and the immunoglobulin heavy chain genes (BCL2-IGH) is present in 80% to 90% of follicular lymphomas and 20% to 30% of diffuse large B-cell lymphomas. Polymerase chain reaction (PCR) analysis for the translocation products suffers from low analytic specificity. As a result, either nested PCR or probe hybridization is required to aid in the identification of the specific translocation products. These added procedures are undesirable in clinical laboratories because nested procedures increase the possibility of contamination and probe hybridization increases assay turnaround time. To simplify the BCL2-IGH assay procedure, we attempted to eliminate the nonspecific PCR products by optimizing the annealing temperatures of the PCR assays using a gradient thermocycler. We showed that gradually increasing the annealing temperature from 55 degrees C to 67 degrees C significantly enhanced the intensity of the specific PCR products while eliminating the nonspecific ones. We compared the simplified procedure with a PCR-probe hybridization method on 68 patient specimens. The simplified procedure had increased analytic and diagnostic specificities with comparable sensitivities. With significantly improved analytic specificity, one round of PCR is sufficient to detect the BCL2-IGH gene rearrangements without further confirmation.

Dynamic expression of matrix metalloproteinases (MMP-2, -9 and -14) and the tissue inhibitors of MMPs (TIMP-1, -2 and -3) at the implantation site during tubal pregnancy

Matrix metalloproteinases (MMPs) are responsible for extracellular matrix (ECM) degradation, and their functions are regulated by tissue inhibitors of MMPs (TIMPs). The evidence for the roles of MMPs and TIMPs in implantation and placentation has remained insufficient in humans, especially during the early stages. Tubal pregnancy has some similarities to normal intrauterine pregnancy and therefore may provide a unique model for implantation studies. In the present study, the expression of MMP-2, -9 and -14, and TIMP-1, -2 and -3 at the feto–maternal interface during tubal pregnancy was examined by immunohistochemistry andin situhybridization. We found that MMP-9 and TIMP-1, -2 and -3 are produced by all types of extravillous cytotrophoblast (EVCT) cells, while MMP-2 and -14 mainly exist in distal column cytotrophoblast (CCT) cells and invasive EVCT cells. Meanwhile, the intensity of MMP-14 and TIMP-1 and -2 increased along the invasive pathway toward maternal interstitium. In addition, MMP-2, -9 and -14 and TIMP-1, -2 and -3 were all detected in the villous CT (VCT) cells. Furthermore, both the mRNA level and immunoreactivity of MMP-9, TIMP-1 and -3 increased, while those of TIMP-2 decreased concurrent with the progression of pregnancy during weeks 3–9. The unique expression pattern of various MMPs and TIMPs at the feto–maternal interface suggests that they may have roles in regulating the controlled invasion of trophoblasts during implantation and placentation. Meanwhile, the study provides a better understanding of the mechanisms involved in cellular events during human pregnancy, especially at the initiation stage of implantation.

Characteristics of the new THOR epithermal neutron beam for BNCT

A characterization of the new Tsing Hua open-pool reactor (THOR) epithermal neutron beam designed for boron neutron capture therapy (BNCT) has been performed. The facility is currently under construction and expected in completion in March 2004. The designed epithermal neutron flux for 1 MW power is 1.7x10(9)n cm(-2)s(-1) in air at the beam exit, accompanied by photon and fast neutron absorbed dose rates of 0.21 and 0.47 mGys(-1), respectively. With (10)B concentrations in normal tissue and tumor of 11.4 and 40 ppm, the calculated advantage depth dose rate to the modified Snyder head phantom is 0.53RBE-Gymin(-1) at the advantage depth of 85 mm, giving an advantage ratio of 4.8. The dose patterns determined by the NCTPlan treatment planning system using the new THOR beam for a patient treated in the Harvard-MIT clinical trial were compared with results of the MITR-II M67 beam. The present study confirms the suitability of the new THOR beam for possible BNCT clinical trials.

Dose-rate scaling factor estimation of THOR BNCT test beam

In 1998, an epithermal neutron test beam was designed and constructed at the Tsing Hua Open-Pool Reactor (THOR) for the purpose of preliminary dosimetric experiments in boron neutron capture therapy (BNCT). A new epithermal neutron beam was designed at this facility, and is currently under construction, with clinical trials targeted in late 2004. Depth dose-rate distributions for the THOR BNCT test beam have been measured by means of activation foil and dual ion chamber techniques. Neutron and structure-induced gamma spectra measured at the test beam exit were configured into a source function for the Monte Carlo-based treatment planning code NCTPlan. Dose-rate scaling factors (DRSFs) were determined to normalize computationally derived dose-rate distributions with experimental measurements in corresponding mathematical and physical phantoms, and to thus enable accurate treatment planning using the NCTPlan code. A similar approach will be implemented in characterizing the new THOR epithermal beam in preparation for clinical studies. This paper reports the in-phantom calculated and experimental dosimetry comparisons and derived DRSFs obtained with the THOR test beam.

Structure determination of surface magic clusters

The structure of a type of surface magic cluster is determined by a combination of scanning tunneling microscopy, density-functional calculations, and dynamical low energy electron diffraction. The diffraction method is applicable because these clusters created through hierarchical self-organization of Ga deposited onto a Si(111)-7x7 surface have identical size and structure and form an ordered array with exact translational symmetry. The unprecedented detailed structure information provided by the diffraction measurement is consistent with direct microscopic imaging and theoretical calculations.

The effects of weight reduction on the rehabilitation of patients with knee osteoarthritis and obesity

OBJECTIVE

To evaluate the effect of weight reduction on the rehabilitation of patients with knee osteoarthritis and obesity.

METHODS

A total of 126 patients with bilateral knee osteoarthritis and obesity were classified into 3 groups by their stages of osteoarthritis. Each group was divided into subgroups a, b, and c. The subjects in subgroup a received weight reduction treatment, those in subgroup b received weight reduction and electrotherapy modalities, and those in subgroup c received electrotherapy modalities to relieve pain.

RESULTS

Pain reduction, weight reduction, ambulation speed, and changes of Lequesne's index were greater in patients in subgroups a and b than in subgroup c after treatment. Although the last pain scores in subgroup b were less than those in subgroup a, as measured by a visual analog scale (VAS), there was no significant difference between their functional status. Significant pain relief (VAS < 2) and an acceptable functional status (Lequesne's index < 7) were indicated when weight reduction was more than 15% and 12%, respectively, of the initial body weight of the individual.

CONCLUSION

Weight reduction was found to be a practical adjuvant treatment in the rehabilitation of patients with knee osteoarthritis.

Expression of integrins and extracellular matrix proteins at the maternal-fetal interface during tubal implantation

Investigation of the expression pattern of integrins and their extracellular matrix (ECM) ligands in trophoblasts at the maternal-fetal interface during tubal pregnancy may aid better understanding of the adhesion and invasion of acceptable maternal endometrium by trophoblast cells at the very early stage of human gestation. In this study, spatial and temporal alterations of integrins and ECM ligands were examined in specimens of tubal pregnancies during weeks 3-9 of gestation. In situ hybridization and immunohistochemistry revealed that relatively high levels of integrin alpha(1), beta(1), alpha(5) subunits and heterdimer alpha(5)beta(1) as well as ECM ligands, were displayed in trophoblast cells as early as weeks 3-4 of gestation. Expression peaked during weeks 5-7 and then, with the exception of integrin alpha(1), which remained high, declined slightly up to weeks 8-9 of gestation. Immunoreactive fibronectin, laminin and type IV collagen were detected in column cytotrophoblastic cells (CTB) and some invasive extravillous cytotrophoblast (EVCT) cells and the alterations were coincident with those of the corresponding integrin receptors in EVCT cells. Laminin was strongly stained in EVCT cells that had invaded maternal blood vessels and deep into the interstitium. Maternal epithelial, endothelial and stromal cells also expressed these integrins and ECM ligands. The results indicate their involvement in mediating the adhesion of trophoblasts to the epithelium of the maternal Fallopian tube. The upregulated expression of these molecules in column CTB and invasive EVCT cells may also facilitate the invasion of trophoblasts into the maternal interstitium. Moreover, trophoblasts possessed the potential for self-controlled adhesion and invasion and appear to reach peak invasive capability in the second month of tubal implantation.

Global gene profiling analysis of mouse uterus during the oestrous cycle

Many genes related to the cyclic changes of the uterus during the oestrous cycle have been identified using a one-by-one approach. In the present study, cDNA microarray technology was applied to investigate the global profile of gene expression of mouse uterus at the oestrous and dioestrous stages. At a certain stage of the oestrous cycle, the uteri of mature CD-1 mice (n=10) were removed, pooled and snap-frozen in liquid nitrogen. Total RNA was extracted to synthesize cDNA probes for microarray assay. By screening 8192 mouse genes and expressed sequence tags (ESTs), 51 upregulated and 51 downregulated genes were identified in oestrous uterus, of which 62 are well characterized and 40 are ESTs. The known genes were assigned to various gene categories according to their main function. The microarray was performed three times with three independent sets of uterine tissue pools. The results of northern blot analysis for small proline-rich protein 2 (Sprr2), 17beta-hydroxysteroid dehydrogenase type 2 (17betaHSD-2), high mobility group 2 (Hmg2), mitotic checkpoint component 2 (Mad2) and an EST AW555366 mRNA were consistent with that of microarray analysis. In situ hybridization was performed to localize the transcript of the EST AW555366. Most of the upregulated genes encode secreted immune-related proteins, proteinases and their inhibitors, indicating their potential involvement in sperm viability as well as capacitation. The downregulated genes mainly encode cell cycle-related factors, implying the active proliferation of uterus at dioestrus.

Molecular actions of sirolimus: sirolimus and mTor

Recent therapeutic strategies to combat organ allograft rejection have focused on T-cell signaling pathways and the molecules that comprise them. The macrolide antibiotic produced by the bacterium Streptomyces hygroscopicus, known as sirolimus or rapamycin, has shown great therapeutic potential in the transplant setting. Sirolimus alone or in combination with other immunosuppressive agents can block acute rejection, chronic graft destruction, and promote permanent allograft acceptance. Sirolimus targets a unique serine-threonine kinase, mammalian target of rapamycin (mTor), which plays a key role in mitogenic and nutritional cells signals. Within T cells, mTor regulates a number of proteins likely dependent on T cell growth factors such as interleukin 2. This review is focused on the molecular mechanisms by which mTor may regulate T-cell signaling cascades and affect T-cell responsiveness, and how sirolimus likely uncouples this activity.