Isolation of Candida in the blood cultures of patients admitted to the Emergency Room in a tertiary care hospital

BackgroundIn Spain, data of candidemia are limited to surveys conducted in specific areas or tertiary care centers. Also, in recent years, attention has shifted toward episodes of candidemia in non-ICU wards.AimsWe reviewed the cases of Candida isolates recovered from the blood of patients admitted to the Emergency Room (ER) in our tertiary care hospital.MethodsThe patients selected for this study had an isolation of Candida in the blood culture. All data were collected retrospectively from the clinical records of a 11-year period.ResultsCandida albicans and other species of the genus were present in 10 and 18 patients, respectively. The patients did not present different clinical features in comparison with other reports of hospitalized patients. All patients had several risk factors for candidemia. Only two patients had received previous antifungal therapy before admission. All the isolates of C. albicans, Candida glabrata and the only isolate of Candida tropicalis were susceptible to all the antifungal agents tested. Only one isolate of Candida parapsilosis was susceptible dose-dependent to fluconazole, and the only isolate of Candida metapsilosis was resistant to fluconazole.ConclusionsIt is essential to evaluate the risk factors, underlying conditions and clinical features in non-hospitalized patients in order to determine whether an empirical treatment for candidemia is appropriate.     

Amplification and Phylogenetic Relationships of a Subfamily of blood, a Retrotransposable Element of Drosophila

To get a better understanding of the effect of interelement selection on the variation of long terminal repeat retrotransposon families, we have investigated the evolutionary history of blood in the Drosophila melanogaster species complex. We carried out a PCR approach to amplify the 5′ untranslated region from blood in the four species of the complex. This procedure revealed two main classes of size variants. Phylogenetic analyses of nucleotide sequences from these variants and blood elements from the Drosophila Genome Projects database show that elements are grouped according to their size, so that they probably correspond to two subfamilies. These two subfamilies arose prior to the split of the complex, and several facts indicate that the expansion of one of them is leading to the competitive exclusion of the other, at least from the euchromatic regions of the genome. Received: 17 August 2000 / Accepted: 20 November 2000     

Free energy surfaces of beta-hairpin and alpha-helical peptides generated by replica exchange molecular dynamics with the AGBNP implicit solvent model

We have studied the potential of mean force of two peptides, one known to adopt a beta-hairpin and the other an alpha-helical conformation in solution. These peptides are, respectively, residues 41-56 of the C-terminus (GEWTYDDATKTFTVTE) of the B1 domain of protein G and the 13 residue C-peptide (KETAAAKFERQHM) of ribonuclease A. Extensive canonical ensemble sampling has been performed using a parallel replica exchange method. The effective potential employed in this work consists of the OPLS all-atom force field (OPLS-AA) and an analytical generalized Born (AGB) implicit solvent model including a novel nonpolar solvation free energy estimator (NP). An additional dielectric screening parameter has been incorporated into the AGBNP model. In the case of the beta-hairpin, the nonpolar solvation free energy estimator provides the necessary effective interactions for the collapse of the hydrophobic core (W43, Y45, F52, and V54), which the more commonly used surface-area-dependent nonpolar model does not provide. For both the beta-hairpin and the alpha-helix, increased dielectric screening reduces the stability of incorrectly formed salt bridges, which tend to disrupt the formation of the hairpin and helix, respectively. The fraction of beta-hairpin and alpha-helix content we obtained using the AGBNP model agrees well with experimental results. The thermodynamic stability of the beta-hairpin from protein G and the alpha-helical C-peptide from ribonuclease A as modeled with the OPLS-AA/AGBNP effective potential reflects the balance between the nonpolar effective potential terms, which drive compaction, and the polar and hydrogen bonding terms, which promote secondary structure formation.     

PTX3 plays a key role in the organization of the cumulus oophorus extracellular matrix and in in vivo fertilization

PTX3 is a prototypic long pentraxin that plays a non-redundant role in innate immunity against selected pathogens and in female fertility. Here, we report that the infertility of Ptx3(-/-) mice is associated with severe abnormalities of the cumulus oophorus and failure of in vivo, but not in vitro, oocyte fertilization. PTX3 is produced by mouse cumulus cells during cumulus expansion and localizes in the matrix. PTX3 is expressed in the human cumulus oophorus as well. Cumuli from Ptx3(-/-) mice synthesize normal amounts of hyaluronan (HA), but are unable to organize it in a stable matrix. Exogenous PTX3 restores a normal cumulus phenotype. Incorporation in the matrix of inter-alpha-trypsin inhibitor is normal in Ptx3(-/-) cumuli. PTX3 does not interact directly with HA, but it binds the cumulus matrix hyaladherin tumor necrosis factor alpha-induced protein 6 (TNFAIP6, also known as TSG6) and thereby may form multimolecular complexes that can cross-link HA chains. Thus, PTX3 is a structural constituent of the cumulus oophorus extracellular matrix essential for female fertility.     

Characterization of the Participation of Sodium Channels on the Rise in Na+ Induced by 4-Aminopyridine (4-AP) in Synaptosomes

The participation of voltage-sensitive Na+ channels (VSSC) on the changes on internal (i) Na+, K+, Ca2+, and on DA, Glu, and GABA release caused by different concentrations of 4-AP was investigated in striatum synaptosomes. TTX, which abolished the increase in Na(i) (as determined with SBFI), induced by 0.1 mM 4-AP only inhibited by 30% the rise in Na(i) induced by 1 mM 4-AP. One millimolar 4-AP markedly decreased the fluorescence of the K+ indicator dye PBFI but 0.1 mM 4-AP did not. Like 1 mM 4-AP, ouabain decreased PBFI fluorescence and increased a considerable fraction of Na(i) in a TTX-insensitive manner. In contrast with the different TTX sensitivity of the rise in Na(i) induced by 0.1 and 1 mM 4-AP, the rise in Ca(i) (as determined with fura-2) induced by the two concentrations of 4-AP was markedly inhibited by TTX, as well as by omega-agatoxin in combination with omega-conotoxin GVIA, indicating that only the TTX-sensitive fraction of the rise in Na(i) induced by 4-AP is linked with the activation of presynaptic Ca2+ channels. It is concluded that the TTX-sensitive fraction of neurotransmitter release evoked by 4-AP is released by exocytosis, and the TTX insensitive fraction involves reversal of the neurotransmitters transporters. This contrasts with the exocytosis evoked by high K+ that is unchanged by TTX and with the neurotransmitter-transporter-mediated release evoked by veratridine, which is highly TTX sensitive and does not require activation of Ca2+ channels.     

Survey of black howler (<Emphasis Type="Italic">Alouatta pigra</Emphasis>) and spider (<Emphasis Type="Italic">Ateles geoffroyi</Emphasis>) monkeys in the Mayan sites of Calakmul and Yaxchilán,Mexico and Tikal,Guatemala

Surveys of populations of spider and howler monkeys were conducted at the Mayan sites of Calakmul and Yaxchilán, Mexico and Tikal, Guatemala. The forests in which these sites are found are part of the largest landmass of tropical rain forests present in Mesoamerica, encompassing about 4 million ha. Triangulation of monkey vocalization combined with ground surveys was used to determine the presence of howler and spider monkey groups. Howler monkey mean troop size at these sites varied from 6.6±2.1 individuals in Yaxchilán to 7.5±1.9 in Calakmul to 8.7±2.2 in Tikal. Density estimates varied from 12.8 individuals/km² in Yaxchilán to 15.2 individuals/km² in Calakmul to 17.8 individuals/km² in Tikal. Mean spider monkey subgroup size varied from 4.7±2.6 individuals in Tikal to 5.6±3.0 individuals in Yaxchilán to 7.7±3.8 individuals in Calakmul. Spider monkey density varied from 17.0 individuals/km² in Yaxchilán to 17.2 individuals/km² in Calakmul to 56.4 individuals/km² in Tikal. All sightings of both howler and spider monkeys at the three sites were in undisturbed rain forest vegetation and spider monkeys in general were more frequently sighted at higher tree heights than howlers. We discuss the value of further acquiring data on howler and spider monkey populations existing in extensive forest tracts and on the conservation value for both primate species of the forests surrounding the Mayan ruins found in this area of Mesoamerica.     

Prey stage preference and functional response of Euseius hibisci to Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae)

The aims of this study were: (a) determine the prey stage preference of female Euseius hibisci (Chant) (Phytoseiidae) at constant densities of different stages of Tetranychus urticae Koch (Tetranychidae), (b) assess the functional response of the predator females to the varying densities of eggs, larvae, or protonymphs of T. urticae, and (c) estimate the functional response of E. hibisci when pollen of Ligustrum ovalifolium was present as well. We conducted experiments on excised pieces of strawberry leaf arenas (Fragaria ananassa) under laboratory conditions of 25 ± 2 °C, 60 ± 5% RH and 12 h photophase. Our results indicated that the predator consumed significantly more prey eggs than other prey stages. Consumption of prey deutonymphs and adults was so low that they were excluded from the non-choice functional response experiments. The functional response on all food items was of type II. The two parameters of the functional response were estimated for each prey type by means of the adjusted non-linear regression model. The highest estimated value a (instantaneous rate of discovery) and the lowest value of T_h (handling time, including digestion) were found for the predator feeding on prey eggs, and a was lowest and T_h highest when fed protonymphs. Using the jack-knife method, the values for the functional response parameters were estimated. The values of a and T_h produced by the model were similar among all prey types except for the eggs, which were different. Using pollen simultaneously with prey larvae decreased the consumption of the latter over the full range of prey densities The suitability of this predator for biological control of T. urticae on strawberry is discussed.     

Defective dendritic cell migration and activation of adaptive immunity in PI3Kgamma-deficient mice

Gene-targeted mice were used to evaluate the role of the gamma isoform of phosphoinositide 3-kinase (PI3Kgamma) in dendritic cell (DC) migration and induction of specific T-cell-mediated immune responses. DC obtained from PI3Kgamma-/- mice showed a reduced ability to respond to chemokines in vitro and ex vivo and to travel to draining lymph nodes under inflammatory conditions. PI3Kgamma-/- mice had a selective defect in the number of skin Langerhans cells and in lymph node CD8alpha- DC. Furthermore, PI3Kgamma-/- mice showed a defective capacity to mount contact hypersensitivity and delayed-type hypersensitivity reactions. This defect was directly related to the reduced ability of antigen-loaded DC to migrate from the periphery to draining lymph nodes. Thus, PI3Kgamma plays a nonredundant role in DC trafficking and in the activation of specific immunity. Therefore, PI3Kgamma may be considered a new target to control exaggerated immune reactions.     

Marked inhibition of retinal neovascularization in rats following soluble-flt-1 gene transfer

BACKGROUND: In mouse models of retinopathy of prematurity (ROP) inhibitors of vascular endothelial growth factor (VEGF) functions administered systemically completely block retinal neovascularization. In contrast, selective ocular VEGF depletion has achieved an approx. 50% inhibition of retinal neovascular growth. It is unclear whether a more complete inhibition of new blood vessel development can be obtained with an anti-VEGF therapy localized to the eye. Therefore, the objective of the present study was to determine the effect of local anti-VEGF therapy in a different animal model which closely mimics human ROP. METHODS: Rats were exposed to alternating cycles of high and low levels of oxygen for 14 days immediately after birth; thereafter, they were intravitreally injected with an adenoviral vector expressing a secreted form of the VEGF receptor flt-1 (Ad.sflt), which acts by sequestering VEGF. Contralateral eyes were injected with the control vector carrying the reporter gene expressing beta-galactosidase (Ad.betaGal). RESULTS: At the peak of retinal neovascular growth, i.e. post-natal day 21 (P21), we observed up to 97.5% decrease in retinal neovascularization in animals injected with Ad.sflt. At the end of observation (P28), no significant difference in retinal vessel number was detected in both oxygen-injured and normoxic Ad.sflt-treated retinas compared with untreated or Ad.betaGal-treated retinas. CONCLUSION: Adenoviral-mediated sflt-1 gene transfer induces a near-complete inhibition of ischemia-induced retinal neovascularization in rats without affecting pre-existing retinal vessels.