Natural hematite as low-cost auxiliary material for improving soil remediation by in-situ microbial community

Microbial-mineral interaction has a broad application prospect in the field of environmental remediation of organic pollutants. However, the disadvantages of long repair cycle and low repair rate limit its industrial application. In this study, natural hematite was used as an auxiliary material for soil remediation in a bio-electrochemical system. It was found that the power density of soil microbial fuel cell (SMFC) system composed of 2.0 mm hematite was 2.889 mW/m2, which is 2.7 times compared with the blank group (1.068 mW/m2) in the particle size optimization experiment. A similarly increased power density (1.068 to 2.467 mW/m2) was observed when the hematite content changed from 0 to 20% in the concentration optimization experiment. Under 20% and 2.0-mm hematite condition, the phenol removal rate was closed to 99% after 7 days, which is 1.9-folds compared with blank control (53%). These results suggest that addition of hematite enhances soil porosity and conductivity, and increases the number of electron acceptors in soil. These findings inspire that this economic and abundant natural mineral is expected to be a potential auxiliary material in the field of soil organic pollutant purification, and expand the understanding of interactions between hematite and microorganisms in nature.

In situ degradation of organic pollutants by novel solar cell equipped soil microbial fuel cell

The soil microbial fuel cell (SMFC) has been widely used for soil remediation for its low cost and being eco-friendly. But low degradation efficiency and high mass transfer resistance limit its performance. This study constructed a solar cell-soil microbial fuel cell (SC-SMFC) with different voltages, which use clean energy to improve system performance. At different voltages, 2.0-V system showed the best performance and the maximum output power increased by 330% compared with SMFC. Moreover, 2.0-V SC-SMFC showed the fastest phenol degradation rate of 14 μg·mL^-1·d^-1 at the concentration of 80 μg/mL, which was twice of SMFC. Further increasing the concentration to 320 μg/mL, the system showed extremely high concentration limit and degraded 90% within 19 days. Under this condition, SC-SMFC still showed excellent cycle stability, with the third-round degrading 90% phenol in 13 days. Finally, electrochemical impedance spectroscopy (EIS) mechanism study showed that solar cells can accelerate microbial metabolic process and reduce the internal resistance, in which the 2.0-V system was only 87% of SMFC. In conclusion, SC-SMFC provides a green, low-cost, and convenient method for in situ soil remediation in the future.

Efficient organic contaminant and Cr (VI) synchronous removing by one-step modified molybdenite cathode microbial fuel cells

As a novel technique with a wide range of applications, microbial fuel cell (MFC) could simultaneously remove organic contaminants and heavy metals in complex wastewater, despite striking differences in physicochemical properties of these contaminant. But its wastewater treatment efficiency is restricted by its lower generation performance. However, approaches for the modification of MFCs' cathode with appropriate catalyst could effectively overcome this limitation. Herein, a new-type efficient cathode catalyst was invented through modifying natural molybdenite via one-step oxidation method. In this case, molybdenite had many changes in morphology (wave-shaped bending, fragmentation and decrescent diameter) during oxidation modification process, and oxidation-modified molybdenite could provide much more active sites for the cathode. After applying this novel cathode catalyst, the electric generation capacity of MFC system increased by 5.08 times, and its simultaneous degradation efficiency of methyl blue (MB) and Cr (VI) increased by 3.35 times (compared with graphite cathode MFC). This study provides a novel low-carbon and environmentally friendly way to prepare high efficiency cathode catalyst materials and provides a new idea of simultaneous purification for organic and metallic pollutants from complex wastewater.

Molecular modelling on small molecular CDK2 inhibitors: an integrated approach using a combination of molecular docking, 3D-QSAR and pharmacophore modelling

Cyclin-dependent kinase 2 (CDK2) has been identified as an important target for developing novel anticancer agents. Molecular docking, three-dimensional quantitative structure-activity relationship (3D-QSAR) and pharmacophore modelling were combined with the ultimate goal of studying the structure-activity relationship of CDK2 inhibitors. The comparative molecular similarity indices analysis (CoMSIA) model constructed based on a set of 3-aminopyrazole derivatives as CDK2 inhibitors gave statistically significant results (q (2) = 0.700; r (2) = 0.982). A HypoGen pharmacophore model, constructed using diverse CDK2 inhibitors, also showed significant statistics ([Formula: see text]Cost = 61.483; RMSD = 0.53; Correlation coefficient = 0.98). The small residues and error values between the estimated and experimental activities of the training and test set compounds proved their strong capability of activity prediction. The structural insights obtained from these two models were consistent with each other. The pharmacophore model summarized the important pharmacophoric features required for protein-ligand binding. The 3D contour maps in combination with the comprehensive pharmacophoric features helped to better interpret the structure-activity relationship. The results will be beneficial for the discovery and design of novel CDK2 inhibitors. The simplicity of this approach provides expansion to its applicability in optimizing other classes of small molecular CDK2 inhibitors.

Scaphoid nonunion reconstructed with vascularized bone-grafting pedicled on 1,2 intercompartmental supraretinacular artery and external fixation

BACKGROUND

Vascularized bone-grafting pedicled on 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) has been recommended as a treatment alternative for established scaphoid nonunion complicated with proximal pole avascular necrosis (AVN). Previous reports focused the studies on the union rate and the revascularization of the transferred graft. However, the postoperative wrist stiffness still a challenging problem and remaining to be solved. The purpose of our study was to determine whether the combination of vascularized bone-grafting pedicled on 1,2 ICSRA and wrist external fixator immobilization provides a more effective strategy for treating established scaphoid nonunion complicated with AVN and improving postoperative range of motion (ROM) of the injured wrist.

PATIENTS AND METHODS

We retrospectively reviewed a consecutive series of 11 patients who had cases of established scaphoid nonunion involving AVN of the proximal pole were treated with vascularized bone-grafting pedicled on 1,2 1,2 ICSRA, internal fixation, and wrist external fixator immobilization. Procedure of wrist arthrolysis was performed before vascularized bone graft transferring. Preoperative and postoperative evaluation included measurement of clinical (wrist ROM and grip strength), radiographic (intrascaphoid angle, scapholunate angle) and functional (Mayo wrist score) parameters.

RESULTS

Osseous union was achieved in all of the 11 cases within an average period of 11.4 weeks. On an average 6.1 years follow-up, there were three excellent, six good and two fair results. Significant improvements were found for Mayo wrist score, wrist ROM, and grip strength (p < 0.01). Intrascaphoid angle and scapholunate angle were significantly improved postoperatively, and there was no significant difference between the postoperative values and the values at the last follow-up. Early functional rehabilitation of the injured wrist under the protection of the fixator did not result in displacement of the transferred graft.

CONCLUSIONS

The results of the present investigation support the use of the vascularized bone graft pedicled on 1,2 ICSRA in the treatment of scaphoid nonunion complicated with proximal pole AVN. Procedures of wrist arthrolysis and early institution of wrist functional rehabilitation under the protection of the external fixator play important role in the restoration of range of motion of the injured wrist.  

Overexpression of AEG-1 in renal cell carcinoma and its correlation with tumor nuclear grade and progression

The study was aimed at detecting the expression of a newly found oncogene, astrocyte elevated gene-1 (AEG-1), in renal cell carcinoma (RCC) and its correlation with histopathologic features and the survival of patients. Real-time reverse transcription-PCR and Western blot showed markedly higher expression of AEG-1 in 8 cases of RCC tissue compared with the paired normal tissue from the same patient. The expression level of AEG-1 was also increased in four RCC cell lines in contrast with normal tubular epithelial human kidney cells 2 (HK-2) at both mRNA and protein levels. Furthermore, immunohistochemistry analysis showed highly expressed AEG-1 in 96 of 102 (94.1%) cases of paraffin-embedded archival RCC tissue. Statistical analysis showed a significant correlation of AEG-1 expression with tumor grade (P <0.001), clinical staging (P = 0.003), T classification (P = 0.003) as well as metastasis classification (P=0.032). The means for survival time of low AEG-1 expression group was 76.98m<br />while high AEG-1expression group was 60.94m. Our results suggest that AEG-1 protein is overexpressed in RCC and plays an important role in tumor differentiation and progression. <br />High AEG-1 expression is closely associated with poor prognosis.

KEYWORDS

Astrocyte elevated gene-1, AEG-1, renal cell carcinoma, prognosis.

Catalpol attenuates MPTP induced neuronal degeneration of nigral-striatal dopaminergic pathway in mice through elevating glial cell derived neurotrophic factor in striatum

The protective effect of an iridoid catalpol extracted and purified from the traditional Chinese medicinal herb Rehmannia glutinosa on the neuronal degeneration of nigral-striatal dopaminergic pathway was studied in a chronic 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)/probenecid C57BL/6 mouse model and in 1-methyl-4-phenylpyridimium (MPP(+)) intoxicated cultured mesencephalic neurons. Rotarod performance revealed that the locomotor ability of mice was significantly impaired after completion of model production and maintained thereafter for at least 4 weeks. Catalpol orally administered for 8 weeks (starting from the second week of model production) dose dependently improved the locomotor ability. HPLC revealed that catalpol significantly elevated striatal dopamine levels without changing the metabolite/dopamine ratios. Nor did it bind to dopamine receptors. Therefore it is unlikely that catalpol resembles any of the known compounds for treating Parkinsonism. Instead, catalpol dose dependently raised the tyrosine hydroxylase (TH) neuron number in substantia nigra pars compacta (SNpc), the striatal dopamine transporter (DAT) density and the striatal glial cell derived neurotrophic factor (GDNF) protein level. Linear regression revealed that both the TH neuron number and DAT density were positively correlated to the GDNF level. In the cultured mesencephalic neurons, MPP(+) decreased the dopaminergic neuron number and shortened the neurite length, whereas catalpol showed protective effect dose dependently. Furthermore, the expression of GDNF mRNA was up-regulated by catalpol to a peak nearly double of normal control in neurons intoxicated with MPP(+) for 24 h but not in normal neurons. The GDNF receptor tyrosine kinase RET inhibitor 4-amino-5-(4-methyphenyl)-7-(t-butyl)-pyrazolo-[3,4-d]pyrimidine (PP1) abolished the protective effect of catalpol either partially (TH positive neuron number) or completely (neurite length). Taken together, catalpol improves locomotor ability by attenuating the neuronal degeneration of nigral-striatal dopaminergic pathway, and this attenuation is at least partially through elevating the striatal GDNF expression.

Expression of DPC4/Smad4 in non-small-cell lung carcinoma and its relationship with angiogenesis

The DPC4 influences tumourigenesis and tumor progression by various mechanisms, including angiogenesis. The aim of this study was to determine whether the expression of DPC4 is related to the angiogenesis in lung cancer and whether it could be involved in its clinical behaviour. Immunohistochemistry revealed that DPC4 was expressed at high level in normal broncho-tracheal epithelium, but at low level in tumor tissues, and closely correlated with tumor lymph node metastasis. This result was further confirmed by Western blot analysis. Furthermore, carcinomas with high DPC4 expression demonstrated low VEGF expression and low MVD (microvessel density) labelled with CD34. In addition, DPC4 siRNA in A549 cells also showed that DPC4 could decrease VEGF protein and mRNA expression, and increase TSP1 protein and mRNA expression. Our findings indicated that DPC4 might be an important biomarker for malignant transformation and be involved in preventing the tumor metastasis by inhibiting tumor angiogenesis.

Measurement of dijet azimuthal decorrelations at central rapidities in pp collisions at sqrt s =1.96 TeV

Correlations in the azimuthal angle between the two largest transverse momentum jets have been measured using the D0 detector in p (-)p collisions at a center-of-mass energy sqrt[s]=1.96 TeV. The analysis is based on an inclusive dijet event sample in the central rapidity region corresponding to an integrated luminosity of 150 pb(-1). Azimuthal correlations are stronger at larger transverse momenta. These are well described in perturbative QCD at next-to-leading order in the strong coupling constant, except at large azimuthal differences where contributions with low transverse momentum are significant.

Search for supersymmetry with gauge-mediated breaking in diphoton events at D0

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

Measurement of the B0s lifetime in the exclusive decay channel B0s-->J/psiphi

Using the exclusive decay B0s-->J/psi(mu+mu-)phi(K+K-), we report the most precise single measurement of the B0s lifetime. The data sample corresponds to an integrated luminosity of approximately 220 pb(-1) collected with the D0 detector at the Fermilab Tevatron Collider in 2002-2004. We reconstruct 337 signal candidates, from which we extract the B0s lifetime, tau(B0s)=1.444(+0.098)(-0.090)(stat)+/-0.020(sys) ps. We also report a measurement for the lifetime of the B0 meson using the exclusive decay B0-->J/psi(mu+mu-)K*0(892)(K+pi-). We reconstruct 1370 signal candidates, obtaining tau(B0)=1.473(+0.052)(-0.050)(stat)+/-0.023(sys) ps, and the ratio of lifetimes, tau(B0s)/tau(B0)=0.980(+0.076)(-0.071)(stat)+/-0.003(sys).

Observation and properties of the X(3872) decaying to J/psipi(+)pi(-) in pp collisions at sqrt[s]=1.96 TeV

We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

Search for doubly charged higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in pp collisions at sqrt[s]=1.96 TeV

A search for pair production of doubly charged Higgs bosons in the process pp -->H(++)H(--) -->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of sqrt[s]=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H(+/-+/-)(L))>118.4 GeV/c(2) and M(H(+/-+/-)(R))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs.

Water for preventing urinary calculi

BACKGROUND

Urinary calculi is a common condition characterized of high incidence and high recurrence rate. For a long time, increased water intake has been the main preventive measure for the disease and its recurrence.

OBJECTIVES

To access the effectiveness of increased water intake for the primary and secondary prevention of urinary calculi.

SEARCH STRATEGY

Relevant RCTs were identified by electronic and documental searches of MEDLINE, EMBASE, the Chinese Biomedical Disk and the Cochrane Central Register of Controlled Trials. No language restriction was applied. Date of last search: May 2004.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of increased water intake for the prevention of urinary calculi and its recurrence.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or weight mean difference (WMD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

No trials of increased water intake for the primary prevention of urinary calculi met the inclusion criteria. One trial with 199 patients provided results of increased water intake for the recurrence of urinary calculi. The recurrence rate was lower in the increased water intake group than that of the no intervention group (12% versus 27%, P = 0.008, RR = 0.45, 95% CI 0.24 to 0.84). The average interval for recurrences was 3.23 +/-1.1 years in increased water intake group and 2.09 +/- 1.37 years in the no intervention group (P = 0.016, WMD = 1.14, 95% CI 0.33 to 1.95).

REVIEWERS' CONCLUSIONS

The evidence from only one trial indicates that increased water intake reduces the risk of recurrence of urinary calculi and prolongs the average interval for recurrences. However further research is required. Due to the lack of appropriate RCTs, no conclusions can be drawn on increased water intake for the primary and secondary prevention of urinary calculi.

Search for the scalar top quark in pp collisions at square root[s] = 1.8 TeV

We have performed a search for scalar top quark (stop) pair production in the inclusive electron-muon-missing transverse energy final state, using a sample of pp events corresponding to 108.3 pb(-1) of data collected with the D0 detector at Fermilab. The search is done in the framework of the minimal supersymmetric standard model assuming that the sneutrino is the lightest supersymmetric particle. For the dominant decays of the lightest stop, t-->b chi+1 and t-->blnu, no evidence for signal is found. We derive cross-section limits as a function of stop ( t ), chargino ( chi+1), and sneutrino ( nu) masses.

Search for new physics using QUAERO: a general interface to D0 event data

We describe QUAERO, a method that (i) enables the automatic optimization of searches for physics beyond the standard model, and (ii) provides a mechanism for making high energy collider data generally available. We apply QUAERO to searches for standard model WW, ZZ, and t t macro production, to searches for these objects produced through a new heavy resonance, and to the first direct search for W'-->WZ. Through this interface, we make three data sets collected by the D0 experiment at square root of [s] = 1.8 TeV publicly available.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Is Chlamydia pneumoniae present in brain lesions of patients with multiple sclerosis?

We investigated the presence of Chlamydia pneumoniae in 81 normal and pathological specimens obtained from postmortem brain tissues of patients with multiple sclerosis and with other neurological or nonneurological diseases. The assays used included PCR amplification of all DNA samples in the initial study. Culture and a second PCR amplification of the organism in a subset of 19 brain specimens were also performed in two separate laboratories. All results were negative. Thus, this study on a large number of brain tissues suggests that C. pneumoniae is not involved in inflammatory demyelination.

Characterization of the Hox cluster from the mosquito Anopheles gambiae (Diptera: Culicidae)

The Hox genes have been found to encode transcription factors, which specify the morphological identity of structures along the anteroposterior axis of animals ranging from worms to mice. The canonical set of nine genes is organized in a cluster in the genome of several protostomes and deuterostomes. However, within insects, whereas the Hox genes are organized in a single cluster in the beetle Tribolium castaneum, they are split into two separate groups in the flies Drosophila melanogaster and Drosophila virilis. The significance of a split Hox cluster is unknown and has been observed in only one organism outside the Drosophila lineage: the nematode Caenorhabditis elegans. We have cloned a majority of the Hox genes from the mosquito Anopheles gambiae (Diptera: Culicidae) and compared their genomic organization with that of Tribolium and Drosophila to determine if a split Hox cluster is found in dipterans aside from the Drosophilidae. We find that the Hox genes in Anopheles, as in Tribolium, are organized in a single cluster that spans a genomic region of at least 700 kb. This finding suggests that, within the insect genome, the partition of the Hox cluster may have evolved exclusively within the Drosophila lineage. The genomic structures of the resident genes, however, appear to be largely conserved between A. gambiae and D. melanogaster.

[Laparoscopic gastric resection]

OBJECTIVE

To modify laparoscopic surgery for gastric diseases.

METHODS

From December 1992 to January 1999, 61 gastric laparoscopic operations were performed in our hospital. The age of the patients ranged from 29 to 78 years (mean 57.4). 17 patients had Billroth II gastrectomy, 1 Billroth I gastrectomy, 2 proximal subtotal gastrectomy, 5 highly selective vagotomy, 3 gastrostomy, and 33 resection of gastric submucosal benign tumor. 54 patients (88.5%) underwent complete laparoscopy, and 7 (11.5%) an assisted one

RESULTS

The mean operative time was (164.2 +/- 93.5) min, the mean estimated blood loss was (218.3 +/- 166.6) ml, and the mean hospital stay was (6.8 +/- 2.1) days. Flatus was present within 48 hours in 86% of the patients. Two patients had laparoscopic surgery for early gastric cancer, and were followed up for more than 55 months. Postoperative complication were noted in 2 patients, who were cured by reoperation and endoscopy therapy respectively. Only 4 patients required postoperative analgesics.

CONCLUSION

Although specific indications need to be defined, laparoscopic surgery is feasible. But long-term follow-up should be made to evaluate its efficacy in treatment of gastric cancer.

The genome sequence of Drosophila melanogaster

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

Genetics in the study of mosquito susceptibility to Plasmodium

Within the past several years, a number of powerful genetic and genomic tools have been developed for use in research on the African malaria vector Anopheles gambiae. While these tools have been developed with a broad range of potential applications in mind, they have been particularly useful in advancing the effort to clone a set of An. gambiae genes that enable a refractory strain of this mosquito to encapsulate and kill a wide variety of different malaria parasites to which this mosquito is normally fully susceptible. This paper describes the latest progress in this map-based cloning research, which involves the collaborative contributions of a number of different laboratories in Europe and the United States.

Use of short tandem repeats for the analysis of genetic variability in sympatric populations of Anopheles gambiae and Anopheles arabiensis

Anopheles gambiae and An. arabiensis were analysed at 30 short tandem repeat (STR) loci originally developed for use in An. gambiae. All specimens were collected from the same village in Kilifi district, coastal Kenya. All 30 loci were amplified in the An. gambiae specimens, whereas 25 out of 30 loci (83.3%) were successfully amplified in the An. arabiensis specimens. Both species had similar levels of polymorphism for the loci that were amplified (93.3% for An. gambiae and 92% for An. arabiensis). Median FST and RST values between the two species were 0.249 and 0.197, respectively, corresponding to Nm values of 0.75 and 0.51, respectively, and suggesting limited interchange of genes between these species. These, together with the relatively high Nei unbiased genetic distance (0.202) between the two sibling species, are consistent with the occurrence of sympatric species with limited gene flow. FST/RST values for individual loci varied greatly (FST range 0.00-0.87; RST range 0.00-0.73), indicating that the loci differ in their ability to measure levels of differentiation between these two species. Location of loci within paracentric inversions seems to be an important factor affecting levels of differentiation measured by the different loci.

Antigenic characterization of HIV-1 gp41 binding proteins

The envelope protein HIV-1 gp41 has been shown to exert various effects on human T-cells, B-cells and monocytes like inhibition of cell proliferation, modulation of MHC expression and cytokine production. In contrast to gpl20, where several receptor molecules have been identified, the receptor for gp41 is still unknown. Using a sepharose column, coupled with recombinant soluble gp41, (rsgp41; Env amino acids 539-684), five gp41-binding proteins of 37, 45, 50, 62 and 100 kDa had been isolated from lysates of the B-cell line Raji. Two mouse antiserums were generated against the proteins P45 and P62 and were tested against the binding specificity of both antiserums. In Western blot analysis the antiserums recognized two protein bands of 45 and 62 kDa in complete Raji cell lysates, as well as the purified proteins P45 and P62, respectively, but did not show any cross-reaction, indicating that the two proteins do not share any immunological epitopes. Besides, the polyclonal antiserums did not recognize the other gp41-binding proteins P37, P50 and P100. Using the P62 antiserum proteins of the same size as in Raji cell lysates were stained in the lysates of the monocytic cell line U937 and the T-cell line H9, demonstrating distribution of P62 in different blood cells. P45 seems not to be identical to HLA-C which had been shown to bind to gp41. These results indicate, that P45 and P62 are two separate gp41-binding proteins without homology to each other or to the other gp41-binding proteins.

The Anopheles albimanus white gene: molecular characterization of the gene and a spontaneous white gene mutation

We have cloned and characterized the white gene of Anopheles albimanus. Comparison of the deduced amino acid sequence of this white gene with its homologs from six species of Diptera show that the An. albimanus gene is most similar to the white gene of An. gambiae (92% identity). A spontaneous white-eyed mutant An. albimanus was caused by an approximately 10 kb insertion into a CT dinucleotide repeat region of intron 2 of the white locus. The flanks of this insertion are long (at least 400 bp), nearly perfect inverted terminal repeat sequences. This cloned white gene should be useful as a marker for germ line transformation of An. albimanus.

Quetzal: a transposon of the Tc1 family in the mosquito Anopheles albimanus

A member of the Tc1 family of transposable elements has been identified in the Central and South American mosquito Anopheles albimanus. The full-length Quetzal element is 1680 base pairs (bp) in length, possesses 236 bp inverted terminal repeats (ITRs), and has a single open reading frame (ORF) with the potential of encoding a 341-amino-acid (aa) protein that is similar to the transposases of other members of the Tc1 family, particularly elements described from three different Drosophila species. The approximately 10-12 copies per genome of Quetzal are found in the euchromatin of all three chromosomes of A. albimanus. One full-length clone, Que27, appears capable of encoding a complete transposase and may represent a functional copy of this element.

Analysis of a vitellogenin gene of the mosquito, Aedes aegypti and comparisons to vitellogenins from other organisms

A genomic clone of the Aedes aegypti vitellogenin A1 gene was sequenced including 2015 bp of 5' untranscribed sequence, 6369 bp of open reading frame interrupted by two introns, and a short 3' untranslated region. Primer extension was used to identify the transcription initiation site. The amino termini of the large and small subunits were located by N-terminal sequencing of vitellin purified from eggs. The length of the signal sequence and the position of the cleavage site between the two subunits were also determined. Three sequential imperfect repeats were found near the beginning of the small subunit. The sequence of the coding region appears to be polymorphic. Comparison of the signal sequences of seven insect vitellogenin genes revealed several conserved leucines, and a conserved position of an intron. However, the signal sequences are not conserved between these genes and the yolk protein genes of Cyclorraphid Dipteran insects. The cleavage sites between the small and large subunits in the vitellogenins of the mosquito, A. aegypti, sawfly, Athalia rosae, boll weevil, Anthonomus grandis, and silkworm, Bombyx mori are flanked by sequences rich in serine. Pairwise dot matrix analysis at the protein level showed that the mosquito, boll weevil and silkworm vitellogenins are significantly related with approx. 50% similarity. One region of the three insect vitellogenin genes, near the N-terminal of the large subunit, showed the highest levels of similarity, from 57.5 to 64.4%. The position of cysteines in insect vitellogenins is conserved, particularly in the C-terminus of the large subunit. Dot matrix comparison of the mosquito vitellogenin with that of Xenopus laevis and Caenorhabditis elegans showed much lower, but still significant degrees of relationship. Pairwise comparisons of the mosquito vitellogenin and the Drosophila melanogaster yolk proteins did not show significant similarities. Potential regulatory regions in the mosquito VgA1 gene were identified by comparison to regulatory elements known from other organisms, especially D. melanogaster, which could provide useful information for further functional analysis.

Interleukin 4 activates a signal transducer and activator of transcription (Stat) protein which interacts with an interferon-gamma activation site-like sequence upstream of the I epsilon exon in a human B cell line. Evidence for the involvement of Janus kinase 3 and interleukin-4 Stat

Germ line C transcripts can be induced by IL-4 in the human B cell line, BL-2. Utilizing a IFN-gamma activation site-like DNA sequence element located upstream of the I epsilon exon, we demonstrated by gel mobility shift assays that IL-4 induced a binding activity in the cytosol and nucleus of BL-2 cells. This factor was designated IL-4 NAF (IL-4-induced nuclear-activating factors) and was identified as a tyrosine phosphoprotein, which translocates from the cytosol to the nucleus upon IL-4 treatment. Because these are the characteristics of a signal transducer and activator of transcription (Stat) protein, we determined whether antibodies to Stat proteins will interfere with gel mobility shift and found that antibodies to IL-4 Stat, also known as Stat6, but not antibodies to other Stat proteins, interfere with the formation of the IL-4 NAF complex. Congruous with the involvement of a Stat protein, IL-4 induced robust Janus kinase 3 (JAK3) activity in BL-2 cells. Cotransfection of JAK3 with IL-4 Stat into COS-7 cells produced an intracellular activity which bound the same IFN-gamma activation site-like sequence and comigrated with IL-4 NAF in electrophoretic mobility shift assay. These results show that IL-4 NAF is IL-4 Stat, which is activated by JAK3 in response to IL-4 receptor engagement.

[Study on dissolution rate and bioavailability of norfloxacin capsule by UV-spectrophotometry]

The dissolution rates and bioavailability of norfloxacin in seven batches of norfloxacin capsules produced by five pharmaceutical factories were studied with rotating basket and UV-spectrophotometry. The results showed that the T50, Td and m of the samples had obvious differences, and the correlation between the dissolution rate and bioavailability differed very obviously. The method used is simple and convenient. So UV-spectrophotometry is one of the methods for the assay of norfloxacin preparations in vitro and in vivo.

Soluble CD23 containing B cell supernatants induce IgE from peripheral blood B-lymphocytes and costimulate with interleukin-4 in induction of IgE

The role of soluble fragments of CD23 and their relationship to interleukin-4 (IL-4) in the in vitro production of IgE by normal human peripheral blood mononuclear cells was examined. Most donors' cells were induced to produce IgE in vitro by IL-4 during a 9- to 21-day culture. This stimulation was not observed in the absence of T cells. Inability of IL-4 to induce IgE in nonresponding cultures was associated with a failure to express CD23 on Lev-19+ natural killer cells; CD23 expression on B cells and monocytes was equivalent in responding and nonresponding subjects. Concentrated supernatants from Epstein-Barr virus-transformed B cell lines containing soluble fragments (sCD23) of the low-affinity Fc epsilon R (Fc epsilon R-II, CD23) induced IgE from all donors' cells in the absence of T cells. The sCD23 containing supernatants were demonstrated to be devoid of IL-4, and their effect could not be abrogated by anti-IL-4. IgE induction by both IL-4 and sCD23-containing supernatant were blocked by anti-CD23 monoclonal antibody. Affinity absorption of sCD23 removed the IgE-inducing activity. The cells most responsive to the sCD23 material were small, resting B cells rather than large in vivo activated cells. IL-4 synergized with sCD23-containing supernatant in the T cell-depleted cultures, and limiting dilution analyses demonstrated that IL-4 caused a more than tenfold increase in the precursor frequency of cells capable of responding to sCD23-containing supernatant with IgE production. These data are consistent with the hypothesis that IL-4 has multiple effects in the ultimate induction of human IgE including (1) commitment of B cells to IgE and (2) the generation of natural killer cell sCD23 fragments that subsequently drive IgE-committed cells to IgE synthesis.