Skin lesions by Scedosporium apiospermum and Nocardia pulmonary infection in an oncologic patient: a case report

BACKGROUND

Fungal infections, other than candidiasis and aspergillosis, are an uncommon entity. Despite this, emerging pathogens are a growing threat. In the following case report, we present the case of an immunocompromised patient suffering from two serious opportunistic infections in the same episode: the first of these, Nocardia multilobar pneumonia; and the second, skin infection by Scedosporium apiospermum. These required prolonged antibacterial and antifungal treatment.

CASE PRESENTATION

This case is a 71-year-old oncological patient admitted for recurrent pneumonias that was diagnosed for Nocardia pulmonary infection. Nervous system involvement was discarded and cotrimoxazole was started. Haemorrhagic skin ulcers in the lower limbs appeared after two weeks of hospital admission. We collected samples which were positive for Scedosporium apiospermum and we added voriconazole to the treatment. As a local complication, the patient presented a deep bruise that needed debridement. We completed 4 weeks of intravenous treatment with slow improvement and continued with oral treatment until the disappearance of the lesions occurs.

CONCLUSIONS

Opportunistic infections are a rising entity as the number of immunocompromised patients is growing due to more use of immunosuppressive therapies and transplants. Clinicians must have a high suspicion to diagnose and treat them. A fluid collaboration with Microbiology is necessary as antimicrobial resistance is frequent.

TiO2 Nanotubes for Solar Water Splitting: Vacuum Annealing and Zr Doping Enhance Water Oxidation Kinetics

Herein, we report the cooperative effect of Zr doping and vacuum annealing on the carrier dynamics and interfacial kinetics of anodized TiO₂ nanotubes for light-driven water oxidation. After evaluation of different Zr loads and different annealing conditions, it was found that both Zr doping and vacuum annealing lead to a significantly enhanced light harvesting efficiency and photoelectrochemical performance. The substitution of Zr⁴⁺ by Ti⁴⁺ species leads to a higher density of surface defects such as oxygen vacancies, facilitating electron trapping on Zr⁴⁺, which reduced the charge recombination and hence boosted the charge transfer kinetics. More importantly, vacuum annealing promoted the presence of surface defects. Furthermore, the mechanistic study through impedance spectroscopy revealed that both charge transfer and surface conductivity are significantly enhanced due the presence of an oxygen-deficient TiO₂ surface. These results represent an important step forward in the optimization of nanostructured TiO₂-based photoelectrodes, with high potential in photocatalytic applications, including solar fuel production.

Electronic Effects Determine the Selectivity of Planar Au-Cu Bimetallic Thin Films for Electrochemical CO2 Reduction

Au-Cu bimetallic thin films with controlled composition were fabricated by magnetron sputtering co-deposition, and their performance for the electrocatalytic reduction of CO₂ was investigated. The uniform planar morphology served as a platform to evaluate the electronic effect isolated from morphological effects while minimizing geometric contributions. The catalytic selectivity and activity of Au-Cu alloys was found to be correlated with the variation of electronic structure that was varied with tunable composition. Notably, the d-band center gradually shifted away from the Fermi level with increasing Au atomic ratio, leading to a weakened binding energy of *CO, which is consistent with low CO coverage observed in CO stripping experiments. The decrease in the *CO binding strength results in the enhanced catalytic activity for CO formation with the increase in Au content. In addition, it was observed that copper oxide/hydroxide species are less stable on Au-Cu surfaces compared to those on the pure Cu surface, where the surface oxophilicity could be critical to tuning the binding strength of *OCHO. These results imply that the altered electronic structure could explain the decreased formation of HCOO^- on the Au-Cu alloys. In general, the formation of CO and HCOO^- as main CO₂ reduction products on planar Au-Cu alloys followed the shift of the d-band center, which indicates that the electronic effect is the major governing factor for the electrocatalytic activity of CO₂ reduction on Au-Cu bimetallic thin films.

Photocatalytic and Photoelectrochemical Degradation of Organic Compounds with All-Inorganic Metal Halide Perovskite Quantum Dots

Inspired by the outstanding optoelectronic properties reported for all-inorganic halide perovskite quantum dots (QDs), we have evaluated the potential of these materials toward the photocatalytic and photoelectrochemical degradation of organic compounds, taking the oxidation of 2-mercaptobenzothiazole (MBT) as a proof-of-concept. First, we determined electrochemically the energy levels of dispersions of perovskite QDs with different band gaps induced by the different ratios between halides (Br and I) and metallic cations (Pb and Sn). Then, we selected CsPbBr₃ QDs to demonstrate the photocatalytic and photoelectrochemical oxidation of MBT, confirming that hole injection takes place from CsPbBr₃ QDs to MBT, resulting in the total degradation of MBT as evidenced by electrospray mass spectrometry analyses. Although the stability and toxicity of these QDs are major issues to address in the near future, the results obtained in the present study open promising perspectives for the implementation of solar-driven catalytic strategies based on these fascinating materials.

WO3/BiVO4: impact of charge separation at the timescale of water oxidation

Unveiling the role of applied bias on the charge carrier dynamics in the WO₃/BiVO₄ junction during water oxidation.

The four hole oxidation of water has long been considered the kinetic bottleneck for overall solar-driven water splitting, and thus requires the formation of long-lived photogenerated holes to overcome this kinetic barrier. However, photogenerated charges are prone to recombination unless they can be spatially separated. This can be achieved by coupling materials with staggered conduction and valence band positions, providing a thermodynamic driving force for charge separation. This has most aptly been demonstrated in the WO₃/BiVO₄ junction, in which quantum efficiencies for the water oxidation reaction can approach near unity. However, the charge carrier dynamics in this system remain elusive over timescales relevant to water oxidation (μs–s). In this work, the effect of charge separation on carrier lifetime, and the voltage dependence of this process, is probed using transient absorption spectroscopy and transient photocurrent measurements, revealing sub-μs electron transfer from BiVO₄ to WO₃. The interface formed between BiVO₄ and WO₃ is shown to overcome the “dead-layer effect” encountered in BiVO₄ alone. Moreover, our study sheds light on the role of the WO₃/BiVO₄ junction in enhancing the efficiency of the water oxidation reaction, where charge separation across the WO₃/BiVO₄ junction improves both the yield and lifetime of holes present in the BiVO₄ layer over timescales relevant to water oxidation.

Improving the Back Surface Field on an Amorphous Silicon Carbide Thin-Film Photocathode for Solar Water Splitting

Amorphous silicon carbide (a-SiC:H) is a promising material for photoelectrochemical water splitting owing to its relatively small band-gap energy and high chemical and optoelectrical stability. This work studies the interplay between charge-carrier separation and collection, and their injection into the electrolyte, when modifying the semiconductor/electrolyte interface. By introducing an n-doped nanocrystaline silicon oxide layer into a p-doped/intrinsic a-SiC:H photocathode, the photovoltage and photocurrent of the device can be significantly improved, reaching values higher than 0.8 V. This results from enhancing the internal electric field of the photocathode, reducing the Shockley-Read-Hall recombination at the crucial interfaces because of better charge-carrier separation. In addition, the charge-carrier injection into the electrolyte is enhanced by introducing a TiO₂ protective layer owing to better band alignment at the interface. Finally, the photocurrent was further enhanced by tuning the absorber layer thickness, arriving at a thickness of 150 nm, after which the current saturates to 10 mA cm^-2 at 0 V vs. the reversible hydrogen electrode in a 0.2 m aqueous potassium hydrogen phthalate (KPH) electrolyte at pH 4.

Cobalt Hexacyanoferrate on BiVO4 Photoanodes for Robust Water Splitting

The efficient integration of photoactive and catalytic materials is key to promoting photoelectrochemical water splitting as a sustainable energy technology built on solar power. Here, we report highly stable water splitting photoanodes from BiVO₄ photoactive cores decorated with CoFe Prussian blue-type electrocatalysts (CoFe-PB). This combination decreases the onset potential of BiVO₄ by ∼0.8 V (down to 0.3 V vs reversible hydrogen electrode (RHE)) and increases the photovoltage by 0.45 V. The presence of the catalyst also leads to a remarkable 6-fold enhancement of the photocurrent at 1.23 V versus RHE, while keeping the light-harvesting ability of BiVO₄. Structural and mechanistic studies indicate that CoFe-PB effectively acts as a true catalyst on BiVO₄. This mechanism, stemming from the adequate alignment of the energy levels, as showed by density functional theory calculations, allows CoFe-PB to outperform all previous catalyst/BiVO₄ junctions and, in addition, leads to noteworthy long-term stability. A bare 10-15% decrease in photocurrent was observed after more than 50 h of operation under light irradiation.

Direct Hydrogen Evolution from Saline Water Reduction at Neutral pH using Organic Photocathodes

Here, we have developed an organic photocathode for water reduction to H₂ , delivering more than 1 mA cm^-2 at 0 V versus RHE and above 3 mA cm^-2 at -0.5 V versus RHE with moderate stability under neutral pH conditions. The initial competitive reduction of water to H₂ and ZnO to metallic Zn is responsible for the dynamic behaviour of both photocurrent and Faradaic efficiency of the device, which reaches 100 % Faradaic efficiency after 90 min operation. In any case, outstanding stable H₂ flow of approximately 2 μmol h^-1 is measured over 1 h at 0 V versus RHE and at neutral pH, after equilibrium between the Zn²⁺ /Zn⁰ concentration in the AZO film is reached. This achievement opens new avenues for the development of allsolution-processed organic photoelectrochemical cells for the solar generation of H₂ from sea water.

Cooperative Catalytic Effect of ZrO2 and α-Fe2 O3 Nanoparticles on BiVO4 Photoanodes for Enhanced Photoelectrochemical Water Splitting

Photoelectrochemical water splitting with metal oxide semiconductors offers a cost-competitive alternative for the generation of solar fuels. Most of the materials studied so far suffer from poor charge-transfer kinetics at the semiconductor/liquid interface, making compulsory the use of catalytic layers to overcome the large overpotentials required for the water oxidation reaction. Herein, we report a very soft electrolytic synthesis deposition method, which allows remarkably enhanced water oxidation kinetics of BiVO₄ photoanodes by the sequential addition of Zr and Fe precursors. Upon a heat treatment cycle, these precursors are converted into monoclinic ZrO₂ and α-Fe₂ O₃ nanoparticles, which mainly act as catalysts, leading to a five-fold increase of the water oxidation photocurrent of BiVO₄ . This method provides a versatile platform that is easy to apply to different semiconductor materials, fully reproducible, and facile to scale-up on large area conductive substrates with attractive implications for technological deployment.

Understanding the synergistic effect of WO3–BiVO4 heterostructures by impedance spectroscopy

The dc resistance allows assessment of the influence of bulk recombination and charge transfer kinetics on the oxygen evolution performance of heterostructured materials.

Competitive photoelectrochemical methanol and water oxidation with hematite electrodes

Photocatalytic water and methanol oxidation were studied at thin film hematite electrodes synthesized by atomic layer deposition (ALD). Systematic photoelectrochemical characterization along with O2 evolution measurements were carried out in order to better understand the mechanisms of both water and methanol oxidation at hematite electrodes. When both water and methanol are present in the solution, they are oxidized competitively with each other, allowing the detection and assignment of distinct surface states characteristic to each process. The measurement of different surface states for methanol and water oxidation, along with the absence of measurable surface states in an inert acetonitrile electrolyte, clearly shows that the detected surface states are chemically distinct reaction intermediates of water or methanol oxidation.

Analysis of bio-anode performance through electrochemical impedance spectroscopy

In this paper we studied the performance of bioanodes under different experimental conditions using polarization curves and impedance spectroscopy. We have identified that the large capacitances of up to 1 mF·cm(-2) for graphite anodes have their origin in the nature of the carbonaceous electrode, rather than the microbial culture. In some cases, the separate contributions of charge transfer and diffusion resistance were clearly visible, while in other cases their contribution was masked by the high capacitance of 1 mF·cm(-2). The impedance data were analyzed using the basic Randles model to analyze ohmic, charge transfer and diffusion resistances. Increasing buffer concentration from 0 to 50mM and increasing pH from 6 to 8 resulted in decreased charge transfer and diffusion resistances; lowest values being 144 Ω·cm(2) and 34 Ω·cm(2), respectively. At acetate concentrations below 1 mM, current generation was limited by acetate. We show a linear relationship between inverse charge transfer resistance at potentials close to open circuit and saturation (maximum) current, associated to the Butler-Volmer relationship that needs further exploration.

Modulating the interaction between gold and TiO2nanowires for enhanced solar driven photoelectrocatalytic hydrogen generation

The interaction strength of Au nanoparticles with pristine and nitrogen doped TiO₂nanowire surfaces was analysed using density functional theory and their significance in enhancing the solar driven photoelectrocatalytic properties was elucidated.

Interpretation of Cyclic Voltammetry Measurements of Thin Semiconductor Films for Solar Fuel Applications

A simple model is proposed that allows interpretation of the cyclic voltammetry diagrams obtained experimentally for photoactive semiconductors with surface states or catalysts used for fuel production from sunlight. When the system is limited by charge transfer from the traps/catalyst layer and by detrapping, it is shown that only one capacitive peak is observable and is not recoverable in the return voltage scan. If the system is limited only by charge transfer and not by detrapping, two symmetric capacitive peaks can be observed in the cathodic and anodic directions. The model appears as a useful tool for the swift analysis of the electronic processes that limit fuel production.

Harnessing Infrared Photons for Photoelectrochemical Hydrogen Generation. A PbS Quantum Dot Based "Quasi-Artificial Leaf"

Hydrogen generation by using quantum dot (QD) based heterostructures has emerged as a promising strategy to develop artificial photosynthesis devices. In the present study, we sensitize mesoporous TiO2 electrodes with in-situ-deposited PbS/CdS QDs, aiming at harvesting light in both the visible and the near-infrared for hydrogen generation. This heterostructure exhibits a remarkable photocurrent of 6 mA·cm(-2), leading to 60 mL·cm(-2)·day(-1) hydrogen generation. Most importantly, confirmation of the contribution of infrared photons to H2 generation was provided by the incident-photon-to-current-efficiency (IPCE), and the integrated current was in excellent agreement with that obtained through cyclic voltammetry. The main electronic processes (accumulation, transport, and recombination) were identified by impedance spectroscopy, which appears as a simple and reliable methodology to evaluate the limiting factors of these photoelectrodes. On the basis of this TiO2/PbS/CdS heterostructrure, a "quasi-artificial leaf" has been developed, which has proven to produce hydrogen under simulated solar illumination at (4.30 ± 0.25) mL·cm(-2)·day(-1).

Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2011-31 January 2012

This article documents the addition of 473 microsatellite marker loci and 71 pairs of single-nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Barteria fistulosa, Bombus morio, Galaxias platei, Hematodinium perezi, Macrocentrus cingulum Brischke (a.k.a. M. abdominalis Fab., M. grandii Goidanich or M. gifuensis Ashmead), Micropogonias furnieri, Nerita melanotragus, Nilaparvata lugens Stål, Sciaenops ocellatus, Scomber scombrus, Spodoptera frugiperda and Turdus lherminieri. These loci were cross-tested on the following species: Barteria dewevrei, Barteria nigritana, Barteria solida, Cynoscion acoupa, Cynoscion jamaicensis, Cynoscion leiarchus, Cynoscion nebulosus, Cynoscion striatus, Cynoscion virescens, Macrodon ancylodon, Menticirrhus americanus, Nilaparvata muiri and Umbrina canosai. This article also documents the addition of 116 sequencing primer pairs for Dicentrarchus labrax.

Evaluation of an automatic ocular filtering method for awake spontaneous EEG signals based on independent component analysis

Electroencephalographic artifacts associated with eye movements are a potential source of error in the EEG analysis when its interpretation is performed for evaluating the influence of drugs and the diagnosis of neurological disorders. In this study, a new automatic method for artifact filtering based on independent component analysis (ICA) is proposed. Automatic artifact identification is based on frequency domain and scalp topography aspects of the independent components. A comparative study between ICA and the 'gold standard' method based on linear regression analysis is performed. The latter does not take into account the mutual contamination between EEG and electrooculographic activity, reducing not only the ocular movements but also interesting cerebral activity, mainly in anteriorly placed electrodes. This limitation is overcome by ICA and the efficiency of this approach is shown for a double-blind, placebo-controlled crossover drug trial in healthy volunteers.

Characterization of the cDNA encoding the 90 kDa heat-shock protein in the Lepidoptera Bombyx mori and Spodoptera frugiperda

This report presents the first hsp90 complete cDNA sequences from two Lepidoptera. The Bombyx mori full sequence was reconstituted from 15 partial cDNA clones belonging to expressed sequence tag libraries obtained from different tissues or cultured cells, thus showing the ubiquitous expression of the hsp90 gene. The Spodoptera frugiperda cDNA was isolated as a full-length clone from a cDNA library established from the Sf9 cell line. Both cDNAs are highly homologous and display the classical amino acid (aa) stretches representing the HSP90 signature. They potentially encode a 716 aa (B. mori) and a 717 aa (S. frugiperda) protein, with a calculated molecular mass of 83 kDa similar to the Drosophila homologous protein. We show that, unlike the vertebrates, hsp90 is a unique gene in both S. frupiperda and B. mori genomes. Sequencing of the corresponding genomic region shows that, contrary to the dipteran homologous gene, the lepidopteran hsp90 gene does not display any intron. Phylogenetic analysis based on the two lepidopteran and 23 other HSP90 aa sequences displays a high consistency with known phylogeny at both high and low taxonomic levels. Transcriptional analysis performed in S. frugiperda shows that the induction of the hsp90 gene only occurs 14 degrees C above physiological growth conditions (42 degrees C).

Formulations of single or multiple H. pylori antigens with DC Chol adjuvant induce protection by the systemic route in mice. Optimal prophylactic combinations are different from therapeutic ones

The ability to induce a protective response against Helicobacter pylori infection has been investigated by systemic immunization of mice with urease formulated with the cationic lipid DC Chol. This compound acts both as a formulating agent and as an adjuvant and induces a balanced Th1/Th2 response shown to be more effective for protection in our previous studies. Urease-DC Chol induced a significant protection in prophylaxis but not in therapeutic immunization. The protection level was between 1.5 and 2 log reduction of bacterial density measured by quantitative culture compared to unimmunized-infected mice. In parallel, the protective efficacy of other H. pylori antigens formulated in a similar way and administered with DC Chol was tested. These antigens were tested alone or in combination in prophylactic and therapeutic regimens. Some combinations of antigens induced a better prophylactic or therapeutic activity than urease alone (0.5-1.5 log further reduction in prophylaxis and therapy respectively, P<0.05). The combinations that induced the best protection were different in prophylaxis and therapy. In conclusion, DC Chol provides a convenient and efficient method to formulate different antigens even when they are present in non-compatible buffers initially. Moreover, the results obtained in protection against H. pylori with such formulations should lead the way to future clinical trials.

Formulations of single or multiple H. pylori antigens with DC Chol adjuvant induce protection by the systemic route in mice. Optimal prophylactic combinations are different from therapeutic ones

The ability to induce a protective response against Helicobacter pylori infection has been investigated by systemic immunization of mice with urease formulated with the cationic lipid DC Chol. This compound acts both as a formulating agent and as an adjuvant and induces a balanced Th1/Th2 response shown to be more effective for protection in our previous studies. Urease-DC Chol induced a significant protection in prophylaxis but not in therapeutic immunization. The protection level was between 1.5 and 2 log reduction of bacterial density measured by quantitative culture compared to unimmunized-infected mice. In parallel, the protective efficacy of other H. pylori antigens formulated in a similar way and administered with DC Chol was tested. These antigens were tested alone or in combination in prophylactic and therapeutic regimens. Some combinations of antigens induced a better prophylactic or therapeutic activity than urease alone (0.5-1.5 log further reduction in prophylaxis and therapy respectively, P<0.05). The combinations that induced the best protection were different in prophylaxis and therapy. In conclusion, DC Chol provides a convenient and efficient method to formulate different antigens even when they are present in non-compatible buffers initially. Moreover, the results obtained in protection against H. pylori with such formulations should lead the way to future clinical trials.

Design, characterization and preclinical efficacy of a cationic lipid adjuvant for influenza split vaccine

We prepared a series of cationic lipid vesicles comprising a cationic cholesterol derivative, DC-Chol with or without a neutral phospholipid, DOPC or DOPE. The vesicles were tested for their ability to bind and adjuvant split inactivated influenza vaccines. We found that DC-Chol-containing liposomes are capable to strongly bind influenza vaccine antigens upon simple mixing with the vaccine. The resulting formulations induced robust anti-influenza immune responses both after s.c. and i.n. administration in BALB/c mice while neutral Cholesterol/DOPC liposomes displayed virtually no stable antigen binding and no adjuvant effect. The parenteral adjuvant effect of DC-Chol on trivalent split influenza vaccines was then confirmed in outbred mice and monkeys. Among the most potent formulations tested, a simple mixture of the vaccine with a microfluidized dispersion of DC-Chol in an aqueous buffer is being considered for further development to produce an improved influenza vaccine.

Comparison of polymorphonuclear cells from healthy donors and differentiated HL-60 cells as phagocytes in an opsonophagocytic assay using antigen-coated fluorescent beads

Polymorphonuclear cells (PMNs) from healthy donors and differentiated HL-60 cells were compared in an opsonophagocytic assay using fluorescent latex beads coated with Streptococcus pneumoniae polysaccharide conjugates. Serum-specific phagocytosis was efficiently mediated by both sources of cells, as measured by flow cytometry, but the mean number of beads ingested per cell was three- to fivefold higher when PMNs were used than when HL-60 cells were used. Nevertheless, differentiated HL-60 cells could be a convenient and standardized source of cells to evaluate the functionality of specific antibodies to vaccine candidates as a coating on fluorescent beads.

Juxta-centromeric region of human chromosome 21 is enriched for pseudogenes and gene fragments

A physical map including four pseudogenes and 10 gene fragments and spanning 500 kb in the juxta-centromeric region of the long arm of human chromosome 21 is presented. cDNA fragments isolated from a selected cDNA library were characterized and mapped to the 831B6 YAC and to two BAC contigs that cover 250 kb of the region. An 85 kb genomic sequence located in the proximal region of the map was analyzed for putative exons. Four pseudogenes were found, including psiIGSF3, psiEIF3, psiGCT-rel whose functional copies map to chromosome 1p13, chromosome 2 and chromosome 22q11, respectively. The TTLL1 pseudogene corresponds to a new gene whose functional copy maps to chromosome 22q13. Ten gene fragments represent novel sequences that have related sequences on different human chromosomes and show 97-100% nucleotide identity to chromosome 21. These may correspond to pseudogenes on chromosome 21 and to functional genes in other chromosomes. The 85 kb genomic sequence was analyzed also for GC content, CpG islands, and repetitive sequence distribution. A GC-poor L isochore spanning 40 kb from satellite 1 was observed in the most centromeric region, next to a GC-rich H isochore that is a candidate region for the presence of functional genes. The pericentric duplication of a 7.8 kb region that is derived from the 22q13 chromosome band is described. We showed that the juxta-centromeric region of human chromosome 21 is enriched for retrotransposed pseudogenes and gene fragments transferred by interchromosome duplications, but we do not rule out the possibility that the region harbors functional genes also.

Genetic and physical analyses of the centromeric and pericentromeric regions of human chromosome 5: recombination across 5cen

Human centromeres are poorly understood at both the genetic and the physical level. In this paper, we have been able to distinguish the alphoid centromeric sequences of chromosome 5 from those of chromosome 19. This result was obtained by pulsed-field gel electrophoresis after cutting genomic DNA with restriction endonucleases NcoI (chromosome 5) and BamHI (chromosome 19). We could thus define a highly polymorphic marker, representing length variations of the D5Z1 domain located at the q arm boundary of the chromosome 5 centromere. The centromeric region of chromosome 5 was then analyzed in full detail. We established an approximately 4.6-Mb physical map of the whole region with five rare-cutting enzymes by using nonchimeric YACs, two of which were shown to contain the very ends of 5cen on both sides. The p-arm side of 5cen was shown to contain an alphoid subset (D5Z12) different from those described thus far. Two genes and several putative cDNAs could be precisely located close to the centromere. Several L1 elements were shown to be present within alpha satellites at the boundary between alphoid and nonalphoid sequences on both sides of 5cen. They were used to define STSs that could serve as physical anchor points at the junction of 5cen with the p and q arms. Some STSs were placed on a radiation hybrid map. One was polymorphic and could therefore be used as a second centromeric genetic marker at the p arm boundary of 5cen. We could thus estimate recombination rates within and around the centromeric region of chromosome 5. Recombination is highly reduced within 5cen, with zero recombinants in 58 meioses being detected between the two markers located at the two extremities of the centromere. In its immediate vicinity, 5cen indeed exerts a direct negative effect on meiotic recombination within the proximal chromosomal DNA. This effect is, however, less important than expected and is polarized, as different rates are observed on both arms if one compares the 0 cM/Mb of the p proximal first 5.5 Mb and the 0.64 cM/Mb of the q proximal first 5 Mb to the sex-average 1.02 cM/Mb found throughout the entire chromosome 5. Rates then become close to the average when one goes further within the arms. Finally, most recombinants (21/22), irrespective of the arm, are of female origin, thus showing that recombination around 5cen is essentially occurring in the female lineage.

Site-specific retrotransposition of L1 elements within human alphoid satellite sequences

In the course of a search for microsatellites as centromeric polymorphic markers at the 3' ends of Alu or L1 elements, we observed a much higher frequency of L1 than Alu elements embedded within alpha satellite DNA. By sequence analysis of the L1 elements at their alphoid locus of insertion, we found that the insertion site was specific, with the consensus being (Py)2-10/ (Pu)3-7. All potential sites within the consensus alphoid 171-bp repeat are occupied by such elements. This confirms the finding by Feng et al. (1996; Human retrotransposon encodes a conserved endonuclease required for retrotransposition, Cell 87:905-916) that the progenitor L1 elements encode a site-specific endonuclease and that they generate copies that are inserted at these specific sites. The analysis of retrotransposed L1 elements within the alphoid domains of the acrocentric chromosomes showed that a number of loci are shared among all five acrocentrics. This sheds light on the manner in which centromeric regions of these chromosomes are exchanging information during evolution.

[Total anomalous pulmonary venous connection. Experience with 70 cases]

PURPOSE

To evaluate the clinical and surgical experience with consecutive patients with isolated total anomalous pulmonary venous connection admitted to the Heart Institute, São Paulo, Brasil.

METHODS

Hospital records of 70 consecutive patients (January 1985 to December 1993) were retrospectively reviewed. There were 28 girls and 42 boys whose ages ranged from two days to four years (mean 20.4 +/- 29 weeks). The following variables were selected for analysis: anatomic type, age at admission, clinical status, the presence of infection, restrictive atrial septal defect, and the presence of pulmonary venous obstruction. Univariate and multivariate analysis were used to identify possible risk factors for death.

RESULTS

The abnormal anatomical connection was supracardiac in 63%, cardiac in 17%, infracardiac in 8.5% and mixed in 11.5% of the cases. Eighteen (25.7%) patients were admitted in poor clinical condition. Infection, mainly pulmonar, was present in 31 (44%) patients. Pulmonary venous obstruction was present in 21% of the patients. Atrial septostomy was performed in 38 patients, 13 of them admitted in a poor clinical status. The preoperative mortality was 15.7% and the operative, 17%. Statistical analysis demonstrated that infection, poor clinical status and age were risk factors for death.

CONCLUSION

Surgical correction of total anomalous pulmonary venous drainage in infancy can be performed at low risk with good results. However early referral to a cardiac care center, agressive preoperative stabilization and postoperative care are important.

[Evaluation of the pharmacovigilance follow-up of zidovudine]

A therapeutic committee was established in Toulouse Regional University Hospital in order to prescribe zidovudine in patients suffering from AIDS. Using an informatic card, the side effects were evaluated in the 125 patients treated by Zidovudine since the creation of the Committee (from July 1987 to January 1989). Zidovudine was prescribed from May 1987 to June 1988 at the total dose of 1,200 mg daily from June 1988 at 900 mg daily. The most frequent side effects were hematologic: zidovudine used alone (or associated with non hematotoxic drugs) elicited in 21.2% of patients a neutropenia (defined as a number of neutrophils less than 1,000/mm3), in 2.4% anaemia (haemoglobin less than or equal to 9 g/100 ml) and in 4.8% neutropenia associated with anaemia. When zidovudine was administered with hematotoxic drugs, neutropenia, anaemia or the association of both were observed in 12.0%, 3.2% and 2.4% of patients respectively. These hematologic side effects were always regressive after drug cessation. However, it is important to underline the low incidence of hematological side effects on red cells of zidovudine in the present study. This result is unexpected. The other side effects of Zidovudine (used alone) did not led to modification in drug treatment: gastrointestinal disturbances (30.4%), headaches (16.8%), insomnia (13.6%), somnolence (6.4%).... These side effects appeared during the four first months and decreased with the continuation of drug treatment. Their imputation was difficult to define and differentiate to evolution of the disease.