Miracle-dz/UniFAR-FTUs huggingface dataset:
Colonization of the Respiratory Tract by a Virulent Strain of Avian Escherichia coli Requires Carriage of a Conjugative Plasmid

ABSTRACT The E3 strain of E. coli was isolated in an outbreak of respiratory disease in broiler chickens, and experimental aerosol exposure of chickens to this strain induced disease similar to that seen in the field. In order to establish whether the virulent phenotype of this strain was associated with carriage of particular plasmids, four plasmid-cured derivatives, each lacking two or more of the plasmids carried by the wild-type strain, were assessed for virulence. Virulence was found to be associated with one large plasmid, pVM01. Plasmid pVM01 was marked by introduction of the transposon TnphoA, carrying kanamycin resistance, and was then cloned by transformation of E. coli strain DH5α. The cloned plasmid was then reintroduced by conjugation into an avirulent plasmid-cured derivative of strain E3 which lacked pVM01. The conjugant was shown to be as virulent as the wild-type strain E3, establishing that this plasmid is required for virulence following aerosol exposure. This virulence plasmid conferred expression of a hydroxamate siderophore, but not colicins, on both strain E3 and strain DH5α. Carriage of this plasmid was required for strain E3 to colonize the respiratory tracts of chickens but was not necessary for colonization of the gastrointestinal tract. However, the virulence plasmid did not confer virulence, or the capacity to colonize the respiratory tract, on strain DH5α. Thus, these studies have established that infection of chickens with E. coli strain E3 by the respiratory route is dependent on carriage of a conjugative virulence plasmid, which confers the capacity to colonize specifically the respiratory tract and which also carries genes for expression of a hydroxymate siderophore. These findings will facilitate identification of the specific genes required for virulence in these pathogens.
Simulated operation and properties of source-gated thin-film transistors

Recently, Shannon and Gerstner introduced the source-gated thin-film transistor (SGT) with undoped a-Si:H as the active layer, claiming that it overcomes some fundamental limitations of the field-effect transistor. In the common thin-film transistors, the channel is controlled by the gate and the current saturates when the drain end of the channel becomes depleted due to the drain voltage. For this operation, the channel contacts to source and drain must be ohmic. By contrast, in the SGT, source has a depletion (Schottky) contact to the film and it is situated on the film surface opposite to the channel. This device is rather similar to the top-contact (TOC) organic field-effect transistor (OFET) with Schottky-type contacts which has been investigated by us. We simulated the SGT and found that indeed the operation is essentially the same as that one of the Schottky-contact TOC OFET, and it differs from the verbal description given by Shannon and Gerstner. We found that, apart from the unusual voltage dependencies of the current with an abrupt transition into saturation at lower drain voltage, the main feature of the SGT is a strongly reduced current due to the series resistance of the depleted region between source and channel. The SGT enables indeed higher voltage gain at lower voltages. However, a reduced transconductance and large source-gate overlap capacitance lead to a reduced cut-off frequency. Also, a reduction of the on-current may be limited by requirements on the on-off ratio.
Baobab Food Products: A Review on their Composition and Nutritional Value

Several authors have published about baobab food products. Data on macronutrients, micronutrients, amino acids, and fatty acids were collected from literature for pulp, leaves, seeds, and kernels of the baobab tree. The results show that baobab pulp is particularly rich in vitamin C; consumption of 40 g covers 84 to more than 100% of the Recommended Daily Intake (RDI) of pregnant women (19–30 years). The leaves are particularly rich in calcium (307 to 2640 mg/100 g dw), and they are known to contain good quality proteins with a chemical score of 0.81. The whole seeds and the kernels have a relatively high lipid content, 11.6 to 33.3 g/100 g dw and 18.9 to 34.7 g/100 g dw, respectively. The pulp and leaves exhibit antioxidant properties with a higher activity in the pulp than in the leaves. Reported nutrient contents of different baobab parts show a large variation, which may have arisen from various factors. Three recommendations are given for future research: 1. More attention should be given to accuracy and precision of analytical methods, 2. Research about digestibility and bioavailability of baobab products is needed, 3. The effect of storage and processing on the nutritional value of baobab products needs to be assessed.
Increased levels of forkhead box M1B transcription factor in transgenic mouse hepatocytes prevent age-related proliferation defects in regenerating liver

The forkhead box (Fox) family of transcription factors share homology in the winged helix/forkhead DNA-binding domain and play important roles in regulating cellular proliferation, differentiation, longevity, and cellular transformation. Forkhead box M1B (FoxM1B) is a ubiquitously expressed member of the Fox transcription factor family whose expression is restricted to proliferating cells and that mediates hepatocyte entry into DNA synthesis and mitosis during liver regeneration. Recent cDNA microarray studies indicated that age-related defects in cellular proliferation are associated with diminished expression of the FoxM1B transcription factor. Here, we show that increased levels of FoxM1B in regenerating liver of old transgenic mice restore the sharp peaks in hepatocyte DNA replication and mitosis that are the hallmarks of young regenerating mouse liver. Restoration of the young regenerating liver phenotype is associated with increased expression of numerous cell cycle regulatory genes that include cyclin D1, cyclin A2, cyclin F, cyclin B1, cyclin B2, Cdc25B, and p55cdc. Cotransfection assays in the human hepatoma HepG2 cell line demonstrated that FoxM1B protein stimulated expression of both the cyclin B1 and cyclin D1 promoters, suggesting that these cyclin genes are a direct FoxM1B transcriptional target. These results suggest that FoxM1B controls the transcriptional network of genes that are essential for cell division and exit from mitosis. Our results indicate that reduced expression of the FoxM1B transcription factor contributes to the decline in cellular proliferation observed in the aging process.
Pricing of risk and volatility dynamics on an emerging stock market: evidence from both aggregate and disaggregate data

Abstract This study analyses risk-return trade-off and behaviour of various volatility dynamics including: volatility, its persistence, mean reversion and speed of mean reversion along with asymmetry and leverage effect on the Pakistani stock market by employing aggregate (aggregate market level) and disaggregate (sectoral level) monthly data for the period from 1998 to 2012. Three generalised autoregressive conditional heteroscedasticity models were applied: GARCH (1,1) for various volatility dynamics; EGARCH for asymmetric and leverage effect and GARCH-M for pricing of risk. The outcomes of the study are as follows: first, the volatility shocks are quite persistent but with varying degrees across the sectors. Both the ARCH effect (short-term effect) and GARCH effect (long-term effect) play their role in generating conditional future stock returns volatility. Further, overall the volatility process is mean reverting; however, the speed of mean reversion varies across the sectors. Secondly, the current study finds little evidence of asymmetry and leverage effect at both aggregate and disaggregates data. Thirdly, the pricing of risk (positive risk premium) is also evident, particularly at the disaggregate data in the Pakistani stock market. Finally, this research study sets the implications for both the policy makers and investors.
Structurally conserved erythrocyte-binding domain in Plasmodium provides a versatile scaffold for alternate receptor engagement

Significance Plasmodium vivax is responsible for the most widely distributed recurring human malaria infections whereas Plasmodium falciparum inflicts the most mortality and morbidity in human populations. Malaria parasites enter our blood cells by making proteins that recognize and bind to their cognate receptors on the red blood cell surface. Our research describes, to our knowledge, the first crystal structure of PvRBP2a, an erythrocyte-binding protein from P. vivax, which revealed a structural scaffold similar to that of PfRh5, the essential erythrocyte-binding protein in P. falciparum. Structural comparisons between PvRBP2a and PfRh5 provide an important foundation toward understanding how P. vivax and P. falciparum parasites use a homologous erythrocyte-binding protein family to engage alternate erythrocyte receptors and ultimately govern host cell specificity. Understanding how malaria parasites gain entry into human red blood cells is essential for developing strategies to stop blood stage infection. Plasmodium vivax preferentially invades reticulocytes, which are immature red blood cells. The organism has two erythrocyte-binding protein families: namely, the Duffy-binding protein (PvDBP) and the reticulocyte-binding protein (PvRBP) families. Several members of the PvRBP family bind reticulocytes, specifically suggesting a role in mediating host cell selectivity of P. vivax. Here, we present, to our knowledge, the first high-resolution crystal structure of an erythrocyte-binding domain from PvRBP2a, solved at 2.12 Å resolution. The monomeric molecule consists of 10 α-helices and one short β-hairpin, and, although the structural fold is similar to that of PfRh5—the essential invasion ligand in Plasmodium falciparum—its surface properties are distinct and provide a possible mechanism for recognition of alternate receptors. Sequence alignments of the crystallized fragment of PvRBP2a with other PvRBPs highlight the conserved placement of disulfide bonds. PvRBP2a binds mature red blood cells through recognition of an erythrocyte receptor that is neuraminidase- and chymotrypsin-resistant but trypsin-sensitive. By examining the patterns of sequence diversity within field isolates, we have identified and mapped polymorphic residues to the PvRBP2a structure. Using mutagenesis, we have also defined the critical residues required for erythrocyte binding. Characterization of the structural features that govern functional erythrocyte binding for the PvRBP family provides a framework for generating new tools that block P. vivax blood stage infection.
Acute endophthalmitis following intravitreal triamcinolone acetonide injection.

PURPOSE To report the clinical features, causative organisms, management, and visual acuity outcomes of eight eyes of eight patients who developed acute postoperative endophthalmitis following intravitreal injection of triamcinolone acetonide (IVTA). DESIGN Retrospective, multicenter, interventional, case series. METHODS A retrospective, interventional, case series of all patients with acute postoperative endophthalmitis following IVTA at seven academic clinical centers between March 2001 and July 2002. RESULTS A total of 922 IVTAs were performed. Eight eyes of eight patients with acute postoperative endophthalmitis were identified in the 6 weeks following IVTA for an incidence of 0.87% (95% confidence interval of 0.38% to 1.70%). The median time to presentation was 7.5 days (range, 1-15 days) after IVTA. The most common clinical findings were iritis (n = 8), vitritis (n = 8), hypopyon (n = 8), pain (n = 7), red eye (n = 6), and decreased vision (n = 5). The median presenting visual acuity was 20/1127 (range, 20/60 to light perception). Initial treatment consisted of vitreous tap and injection of antibiotics (n = 6) or pars plana vitrectomy and injection of intravitreal antibiotics (n = 2). Intraocular cultures yielded identification in seven patients. One demonstrated intracellular gram-positive cocci in chains with numerous polymorphonuclear cells on gram stain. The median postinfection vision was 20/400 (range, 20/40 to no light perception). Three patients ended up with no light perception visual acuity, including enucleation (n = 1) and phthisis (n = 1). CONCLUSIONS Acute postoperative endophthalmitis following IVTA occurs rapidly and can result in severe loss of vision.
Light interaction with human skin: from believable images to predictable models

Recent research efforts in image synthesis have been directed toward the rendering of believable and predictable images of biological materials. This course addresses an important topic in this area, namely the predictive simulation of skin's appearance. The modeling approaches, algorithms and data examined during this course can be also applied to the rendering of other organic materials such as hair and ocular tissues.
Ultrasonic spectrum analysis for tissue assays and therapy evaluation

Ultrasonic spectrum analysis procedures have been developed to measure tissue morphologic features that are not well depicted with conventional ultrasonography. This article reviews some of the applications of spectral techniques and provides an expanded theoretical framework showing how measured spectral features are related to the spatial autocorrelation function descriptive of tissue microstructure. Explicit relationships are obtained that describe how linear‐regression spectral parameters are related to the effective mean sizes, concentrations, and relative mechanical properties of scattering centers in tissue. In vitro, in vivo, and clinical results are presented illustrating how these techniques can be used to evaluate tissue alterations induced by ultrasonic hyperthermia and ablative treatments of tumors. These results show that ultrasonic spectrum analysis can provide quantitative information regarding changes in microstructure attributes. Spectral parameter images in two and three dimensions demonstrate how such procedures can map the spatial extent and severity of these changes, thereby providing a quantitative basis for assessing the results of tumor therapy. © 1997 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 8: 3–10, 1997
Comparative evaluation of macrodilution and chromogenic agar screening for determining fluconazole susceptibility of Candida albicans

A simple screening method for fluconazole susceptibility using CHROMagar Candida with fluconazole was compared with the National Committee for Clinical Laboratory Standards (NCCLS) macrobroth method. In this agar dilution method, susceptible Candida albicans colonies are smaller on medium with fluconazole than on fluconazole-free medium. Yeasts with decreased susceptibility have normal-sized colonies on medium containing fluconazole. On agar with 16 micrograms of fluconazole per ml, 32 of 34 strains with NCCLS MICs of > or = 16 micrograms/ml were correctly predicted, as were 66 of 68 with MICs of < 16, an agreement of 96%. On agar with 8 micrograms of fluconazole per ml, 38 of 41 isolates with MICs of > or = 8 were correctly predicted, as were 59 of 61 isolates with MICs of < 8, an agreement of 95%. This agar dilution methods appears to highly correlate with NCCLS macrobroth methods for detection of C. albicans and may be an effective screen for fluconazole susceptibility.
Human CD8+ T Cell Memory Generation in Puumala Hantavirus Infection Occurs after the Acute Phase and Is Associated with Boosting of EBV-Specific CD8+ Memory T Cells1

The induction and maintenance of T cell memory is incompletely understood, especially in humans. We have studied the T cell response and the generation of memory during acute infection by the Puumala virus (PUUV), a hantavirus endemic to Europe. It causes a self-limiting infection with no viral persistence, manifesting as hemorrhagic fever with renal syndrome. HLA tetramer staining of PBMC showed that the CD8+ T cell response peaked at the onset of the clinical disease and decreased within the next 3 wk. Expression of activation markers on the tetramer-positive T cells was also highest during the acute phase, suggesting that the peak population consisted largely of effector cells. Despite the presence of tetramer-positive T cells expressing cytoplasmic IFN-γ, PUUV-specific cells producing IFN-γ in vitro were rare during the acute phase. Their frequency, as well as the expression of IL-7Rα mRNA and surface protein, increased during a follow-up period of 6 wk and probably reflected the induction of memory T cells. Simultaneously with the PUUV-specific response, we also noted in seven of nine patients an increase in EBV-specific T cells and the transient presence of EBV DNA in three patients, indicative of viral reactivation. Our results show that in a natural human infection CD8+ memory T cells are rare during the peak response, gradually emerging during the first weeks of convalescence. They also suggest that the boosting of unrelated memory T cells may be a common occurrence in human viral infections, which may have significant implications for the homeostasis of the memory T cell compartment.
Expression of MIS in the Testis Is Downregulated by Tumor Necrosis Factor Alpha through the Negative Regulation of SF-1 Transactivation by NF-κB

ABSTRACT The expression of Mullerian inhibiting substance (MIS), a key molecule in sex differentiation and reproduction, is tightly regulated. It has been suggested that meiotic germ cells repress MIS expression in testicular Sertoli cells, although the substance responsible for this cell-cell communication remains unknown. Here, we present the cytokine tumor necrosis factor alpha (TNF-α) as a strong candidate for such a substance and its downstream molecular events. TNF-α inhibited MIS expression in testis organ cultures, and TNF-α−/− testes showed high and prolonged MIS expression. Furthermore, in transient-transfection assays TNF-α suppressed the MIS promoter that was activated by steroidogenic factor 1 (SF-1), one of the major transcription factors that regulate MIS expression. The modulation of SF-1 transactivation by TNF-α is through the activation of NF-κB, which subsequently interacts with SF-1 and represses its transactivation. The physical association of NF-κB with SF-1 was shown by yeast two-hybrid protein interaction, glutathione S-transferase pull-down, and coimmunoprecipitation (ChIP) analyses. ChIP assays also revealed that endogenous NF-κB, as well as SF-1, is recruited to the MIS promoter upon TNF-α signaling. SF-1-bound NF-κB subsequently recruits histone deacetylases to inhibit the SF-1-activated gene expression. These results may identify, for the first time, the responsible substance and its action mechanism underlying the repression of MIS expression by meiotic germ cells in the testis.
Cumulative antiplatelet effect of low‐dose enteric coated aspirin

Enteric coated aspirin (ECA) at doses of 325–1300 mg is an effective alternative to regular aspirin for inhibition of platelet activity while avoiding gastric irritation. The objectives of this study were to determine: (1) the lowest chronic dose of ECA providing effective inhibition of platelet activities, (2) the time course of the inhibition, and (3) the reappearance of platelet cyclo‐oxygenase activity. Seven subjects were studied before and after seven daily doses of 40–325 mg ECA. Serum thromboxane (TX) B2 levels indicated that the lowest dose of ECA resulting in greater than 90% inhibition of platelet cyclo‐oxygenase was 80 mg/d. Platelet aggregation and ATP release in response to collagen (1 μg/ml) and arachidonic acid (1 mM) were abolished and bleeding times were prolonged from 6.1 ± 1.5 min to 9.7 ± 2.8 min (mean ± SD, P<0.01). Examination of platelet cyclo‐oxygenase activity on a daily basis revealed that 24 h after the first 80 mg dose serum TXB2 had decreased by approximately 60% and was suppressed by more than 90% after four doses. Recovery of platelet cyclo‐oxygenase activity after a single 80 mg dose of ECA was delayed for 48–72 h indicating that aspirin reached the systemic circulation. We conclude that chronic inhibition of platelet activity may be achieved in a cumulative manner with 80 mg ECA/d.
A Multicenter Randomized, Double-Blind, Placebo-Controlled Late-Phase II/III Study of Recombinant Human Interleukin 11 in Acute Myelogenous Leukemia

To investigate the efficacy of using recombinant human interleukin 11 (rhIL-11) to reduce the need for platelet transfusions, we performed a randomized, double-blind phase II/III study with 110 acute myelogenous leukemia (AML) patients in the first complete remission. Following chemotherapy patients were subcutaneously administered either placebo (n = 37) or rhIL-11 at a dose of 25 μg/kg (n = 37) or 50 μg/kg (n = 36). rhIL-11 administration was well tolerated. There was no difference between the rhIL-11 and placebo groups in the frequency and volume of platelet transfusions. In a perprotocol analysis set (101 patients), the platelet transfusion frequency in the 50-μg/kg group (3.0 ± 1.76 times) was significantly lower than in the placebo group (3.9 ±2.35 times; multiplicity-adjusted P = .049). We analyzed infection-related events retrospectively. The frequency of fever was significantly decreased in the 50-μg/kg, 25-μg/kg, and placebo groups (66.7%, 70.3%, and 89.2%, respectively; P = .018, Cochran-Armitage test). Stomatitis was less frequent in the 50-μg/kg and 25-μg/kg groups (2.8% and 0%, respectively) than in the placebo group (21.6%, P = .0012). These results show that rhIL-11 does not reduce the platelet transfusion requirement in AML patients, but the retrospective analysis confirms the previous finding that rhIL-11 reduces infection in patients undergoing chemotherapy.
Effect of antiretroviral drugs on maternal CD4 lymphocyte counts, HIV-1 RNA levels, and anthropometric parameters of their neonates.

PURPOSE To study the effect of antiretroviral drugs administered during pregnancy on CD4 lymphocyte counts and HIV-1 RNA levels of pregnant women and on the anthropometric parameters of their neonates. METHODS A prospective study was conducted on 57 pregnant women and their neonates divided into 3 groups: ZDV Group, HIV-infected mothers taking zidovudine (n=20); triple therapy (TT) Group, mothers taking zidovudine+lamivudine+nelfinavir (n=25), and Control Group, normal women (n=12). CD4 lymphocyte counts and HIV-1 RNA levels of pregnant women were analyzed during two periods of pregnancy. The perinatal prognosis took into account preterm rates, birth weight, intrauterine growth restriction, perinatal death, and vertical transmission of HIV-1. Data were analyzed statistically using the nonparametric chi-square, Mann-Whitney, Friedman, Kruskal-Wallis, and Wilcoxon matched pairs tests, with the level of significance set at P<. 05. RESULTS The major maternal demographic and anthropometric data were homogeneous for the various groups. HIV-1 viral burden, which was initially elevated, median of 14,370 copies/mL, was significantly reduced in the TT group, reaching 40 copies/mL. With respect to T-CD4+ lymphocyte counts, there was a significant recovery in Group TT at the end of pregnancy, this value being significantly different from that for the ZDV group (P=0052). There was no difference between groups regarding gestation length, Apgar scores, or neonatal anthropometric classification. There was no case of vertical HIV-1 transmission. CONCLUSIONS The results obtained for the present series demonstrate the efficiency and suggest safety of the use of antiretroviral drugs during pregnancy as revealed by anthropometric parameters of the neonate.