Health-related quality of life of adolescents living with HIV treated at the HIV Clinic at the National Institute of Pediatrics at Mexico City

Introduction

ATR for children has successfully increase survival to adolescence. Health-related quality of life (HRQoL) is relevant to evaluate the impact of the disease on well-being in adolescents living with HIV (ALH). Kidscreen-52 questionnaire is validated in mexican adolescents to measure HRQoL

Objectives

To evaluate health related quality of life in a sample of 22 mexican ALH

Methods

A sample of ALH in treatment at the HIV Clinic during 2021, were evaluated with Kidscreen-52 by a child psychiatrist. Statistics included non parametric tests and Cohen “d” and “r” size effect to compare T means between ALH and Kidscreen-52 standardized scores.

Results

Mean age:14.4+2.5. Gender: 11(50%)boys, 11(50%)girls. ALH showed significantly lower scores in all domains. Girls reported lower scores in physical well-being(p=0.047) and autonomy (p=0.023). Orphan ALH had lower scores in mood and emotions (p=0.021)

KIDSCREEN-52	ALH MEAN/SD	KIDSCREEN-52 MEAN/SD	COHEN’S”d”	“r”
PYSICAL WELL-BEING	18.45+3.9	42.6+6.6	- 4.4	-0. 91
PSYCHOLOGICAL WELL-BEING	23.04+6.03	51.2+8.7	- 3.7	-0. 88
MOOD	25.3+6.13	44.8+7.5	- 2.8	-0. 81
SELF-PERCEPTION	20.27+3.22	47.3+7.6	- 4.6	-0. 91
AUTONOMY	18.09+4.9	46.6+9.4	- 3.8	-0. 88
SOCIAL SUPPORT AND PEERS	24+5.1	51.0+9.4	-3.5	-0. 87
PARENTS AND HOME LIFE	20.95+6.2	48.6+9.4	- 3.4	- 0.86
FINANCIAL RESOURCES	9.04+3.21	44.7+7.3	- 6.3	-0. 95
SCHOOL ENVIROMENT	19.73+7.13	53.3+7.9	- 4.46	-0. 91
SOCIAL ACCEPTANCE	12.91+2.11	46.3+9.6	- 4.8	- 0.92

Conclusions

- HRQoL were significantly lower in ALH. -Girls showed significantly lower scores in physical well-being and autonomy. - ALH orphans showed significantly lower scores in mood and emotions domain

Disclosure

No significant relationships.

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Subphthalocyanine-Diketopyrrolopyrrole Conjugates: 3D Star-Shaped Systems as Non-Fullerene Acceptors in Polymer Solar Cells with High Open-Circuit Voltage

Invited for this month's cover are the collaborating groups of Prof. Ángela Sastre-Santos, Universidad Miguel Hernández, Prof. Lluis F. Marsal, Universitat Rovira i Virgili and Prof. Tomás Torres, Universidad Autónoma de Madrid, Spain. The cover shows a toy doll holding an umbrella which represents a non-planar, highly conjugated subphthalocyanine-diketopyrrolopyrrole hybrid molecule for non-fullerene organic solar cells. When the sun shines on the umbrella, it absorbs the light, and the doll slides down a polymeric flexible solar cell like a slide, where electrons are produced and electricity flows into the magic wand to illuminate the room. More information can be found in the Full Paper by Ángela Sastre-Santos, Lluis F. Marsal, Tomás Torres, and co-workers.

Efficient charge-transfer from diketopyrrolopyrroles to single-walled carbon nanotubes

In this contribution, the excited state charge-transfer interactions between single-walled carbon nanotubes (SWCNTs) and a variety of phenyl, 4-bromophenyl, and thiophene substituted diketopyrrolopyrroles (DPPs), is described. Atomic force microscopy (AFM) and aberration corrected high resolution transmission electron microscopy (AC-HRTEM) corroborated the successful formation of DPP/SWCNTs. Steady-state absorption, fluorescence, and Raman spectroscopies all gave insights into the impact on their ground and excited states as well as on the nature of their electronic communication/interaction. Of great value was time-resolved transient absorption spectroscopy on the femto- and nanosecond time-scales; it assisted in deciphering the charge-transfer mechanism from the DPPs to the SWCNT and in analyzing the dynamics thereof with transfer efficiencies of up to 81%. Important confirmation for the one-electron oxidized DPPs came from pulse radiolysis assays with focus on establishing their spectral fingerprints. Our full-fledged work demonstrates that the successful preparation of stable DPP/SWCNTs represents an important step towards establishing them as a viable alternative to porphyrin-based systems in emerging applications such as solar energy conversion.

Interfacial versus Bulk Properties of Hole-Transporting Materials for Perovskite Solar Cells: Isomeric Triphenylamine-Based Enamines versus Spiro-OMeTAD

Here, we report on three new triphenylamine-based enamines synthesized by condensation of an appropriate primary amine with 2,2-diphenylacetaldehyde and characterized by experimental techniques and density functional theory (DFT) computations. Experimental results allow highlighting attractive properties including solid-state ionization potential in the range of 5.33-5.69 eV in solid-state and hole mobilities exceeding 10^-3 cm²/V·s, which are higher than those in spiro-OMeTAD at the same electric fields. DFT-based analysis points to the presence of several conformers close in energy at room temperature. The newly synthesized hole-transporting materials (HTMs) were used in perovskite solar cells and exhibited performances comparable to that of spiro-OMeTAD. The device containing one newly synthesized hole-transporting enamine was characterized by a power conversion efficiency of 18.4%. Our analysis indicates that the perovskite-HTM interface dominates the properties of perovskite solar cells. PL measurements indicate smaller efficiency for perovskite-to-new HTM hole transfer as compared to spiro-OMeTAD. Nevertheless, the comparable power conversion efficiencies and simple synthesis of the new compounds make them attractive candidates for utilization in perovskite solar cells.

Subphthalocyanine-Diketopyrrolopyrrole Conjugates: 3D Star-Shaped Systems as Non-Fullerene Acceptors in Polymer Solar Cells with High Open-Circuit Voltage

Four star-shaped electron acceptors (C1 -OPh, C3 -OPh, C1 -Cl and C3 -Cl) based on a subphthalocyanine core bearing three diketopyrrolopyrrole wings linked by an acetylene bridge have been synthesized. These derivatives feature two different axial substituents (i. e., 4-tert-butylphenoxy (OPh) or chlorine (Cl)) and for each of them, both the C1 and the C3 regioisomers have been investigated. The four compounds exhibit a broad absorption band in the 450-700 nm region, with bandgap values near to 2 eV. These materials were applied in the active layer of inverted bulk-heterojunction polymer solar cells in combination with the donor polymer PBDB-T. Derivatives bearing the OPh axial group showed the best performances, with C1 -OPh being the most promising with a PCE of 3.27 % and a Voc as high as 1.17 V. Despite presenting the widest absorption range, the photovoltaic results obtained with C1 -Cl turned out to be the lowest (PCE=1.01 %).

Irradiation dose does not affect male reproductive organ size, sperm storage, and female remating propensity in Ceratitis capitata

The Mediterranean fruit fly Ceratitis capitata is a globally invasive pest, often controlled with the sterile insect technique (SIT). For the SIT, mass-rearing of the target insect followed by irradiation are imperatives. Sterile males are often less able to inhibit female remating and transfer less number of sperm, and even irradiation could affect male reproductive organs, with consequences for their ability to inhibit female remating. On the other hand, male age could affect their ability to modulate female response after mating. Here, we evaluated the quality of the genetic sexing strain Vienna-8-tsl mass-reared in Bioplanta San Juan, Argentina, under laboratory conditions, with regard to: (i) the ability of sterile males irradiated at 100 or 140 Gy to inhibit female remating, in the same day and at 24 h of first copulation; (ii) the ability of 3, 4 or 5 day-old sterile males to inhibit female remating at 24 h of first copulation, and (iii) the effect of a reduction in irradiation doses on the number of sperm stored by females and reproductive organ size in virgin males. Sterile males were better able than wild males to inhibit female remating in the same day of first copulation and as able as wild males 1 day after first copulation. Male age did not affect their ability to inhibit female receptivity. Number of sperm stored by females, testes size and ectodermal accessory glands size were not affected by male identity, while sterile 100 Gy males had larger mesodermal accessory glands than control lab males. A reduction in irradiation dose does not impact any variable measured, except for percentage of sperm-depleted females: females mated with sterile 100 Gy males had lower probabilities to store sperm. The results showed here are very encouraging for tsl Vienna 8 strain reared in Argentina and are discussed in comparison with previous studies in C. capitata female remating with dissimilar results.

Dopant-Free Hole-Transport Materials with Germanium Compounds Bearing Pseudohalide and Chalcogenide Moieties for Perovskite Solar Cells

Hole-transport materials (HTMs) are key electronic components for the functioning of perovskite solar cells (PSCs) as they extract the photogenerated holes from the perovskite to be transported subsequently to the back electrode while minimizing the loss from electron recombination. Herein, we report the synthesis and characterization of novel germanium-based compounds with [{HC(CMeNAr)₂}GeNCS] (2), [{HC(CMeNAr)₂}Ge(S)NCS] (3), and [{HC(CMeNAr)₂}Ge(Se)NCS] (4) compositions, with Ar = 2,6-iPr₂C₆H₃ and the photovoltaic performance of 3 and 4 that is the same as for HTM in PSC. All compounds displayed excellent thermal properties and an appropriate alignment of energy levels for the perovskite with maximum optical absorption in the near-UV region. As revealed by space-charge limited-current (SCLC) measurements, compounds 3 and 4 have competing hole mobilities of about 1.37 × 10^-4 and 4.88 × 10^-4 cm² V^-1 s^-1, respectively. Upon assessing PSC devices using 3 and 4 with triple-cation perovskite absorber Cs_0.05(MA_0.17FA_0.83)_0.95Pb(I_0.83Br_0.17)₃, the power conversion efficiencies (PCEs) were about 13.03 and 9.23%, respectively, both without doping and additives, and were compared with benchmark HTM spiro-OMeTAD (2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene). Quantum chemical calculations with DFT showed that the optoelectronic properties are strongly influenced by the combined contributions of the germanium atom, the pseudohalide moiety (NCS^-), and chalcogenides (S^2- or Se^2-). Fine tuning the electronic properties of germanium is thus a good strategy for the targeted synthesis of potential conducting molecules in PSCs.

Remote monitoring of Molten Core-Concrete Interaction experiment with Optical Fibre Sensors & perspectives to improve nuclear safety – DISCOMS project

The DISCOMS project (Distributed Sensing for Corium Monitoring and Safety) aimed at providing innovative solutions not requiring local electrical power supplies, for remote monitoring of a severe nuclear accident. The solutions are based on both long length SPNDs (Self Powered Neutron Detectors) and on distributed OFSs (Optical Fibre Sensors) capable to detect the onset of a severe accident, the corium pouring on the containment building concrete basemat, and its interaction with the concrete floor under the reactor vessel, until it spreads in the core catcher (EPR case). This paper mainly focuses on these last three detection targets achievable with distributed OFSs. It is based on the results of a Molten Core & Concrete Interaction (MCCI) experiment, namely VULCANO, held in June 2018 with a concrete crucible equipped with overall ~ 180 m long optical fibre sensing cables. This small scale experiment (50 kg of prototypical corium) has demonstrated the ability of distributed OFSs to remotely provide useful data during the MCCI run: i) temperature profiles images up to about 580°C (single wavelength Raman DTS reflectometer) until cooling down to room temperature, ii) high spatial-resolution frequency shifts profiles, due to combined (non-selective) strain and temperature influences (Rayleigh OFDR and Brillouin reflectometers), and iii) cables lengths ablated by the corium on sections weakened by the temperature (Raman DTS, Rayleigh OFDR, telecom and photon counting reflectometers).

p-Phenylene-bridged zinc phthalocyanine-dimer as hole-transporting material in perovskite solar cells

The synthesis and characterization of a [Formula: see text]-phenylene-bridged ZnPc dimer along with a preliminary study of this material as hole transporting material (HTM) in perovskite solar cells is described. The maximum efficiencies that obtained are 15.2% for ZnPc-[Formula: see text]-ZnPc 1, thus demonstrating the potential of the Pc dimers that could pave the path to achieve highly efficient PSCs (PCE >20%).

Diphenylphenoxy-Thiophene-PDI Dimers as Acceptors for OPV Applications with Open Circuit Voltage Approaching 1 Volt

Two new perylenediimides (PDIs) have been developed for use as electron acceptors in solution-processed bulk heterojunction solar cells. The compounds were designed to exhibit maximal solubility in organic solvents, and reduced aggregation in the solid state. In order to achieve this, diphenylphenoxy groups were used to functionalize a monomeric PDI core, and two PDI dimers were bridged with either one or two thiophene units. In photovoltaic devices prepared using PDI dimers and a monomer in conjunction with PTB7, it was found that the formation of crystalline domains in either the acceptor or donor was completely suppressed. Atomic force microscopy, X-ray diffraction, charge carrier mobility measurements and recombination kinetics studies all suggest that the lack of crystallinity in the active layer induces a significant drop in electron mobility. Significant surface recombination losses associated with a lack of segregation in the material were also identified as a significant loss mechanism. Finally, the monomeric PDI was found to have sub-optimum LUMO energy matching the cathode contact, thus limiting charge carrier extraction. Despite these setbacks, all PDIs produced high open circuit voltages, reaching almost 1 V in one particular case.

Edge-on and face-on functionalized Pc on enriched semiconducting SWCNT hybrids

Enriched semiconducting single-walled carbon nanotubes (SWCNT (6,5) and SWCNT (7,6)) and HiPco nanotubes were covalently functionalized with either zinc phthalocyanine or silicon phthalocyanine as electron donors. The synthetic strategy resulted in edge-on and face-on geometries with respect to the phthalocyanine geometry, with both phthalocyanines held by an electronically conducting diphenylacetylene linker. The extent of functionalization in the MPc-SWCNT (M = Zn or Si) donor-acceptor nanohybrids was determined by systematic studies involving AFM, TGA, XPS, optical and Raman techniques. Intramolecular interactions in MPc-SWCNT nanohybrids were probed by studies involving optical absorbance, Raman, luminescence and electrochemical studies. Different degrees of interactions were observed depending on the type of MPc and mode of attachment. Substantial quenching of MPc fluorescence in these hybrids was observed from steady-state and three-dimensional fluorescence mapping, which suggests the occurrence of excited state events. Evidence for the occurrence of excited state charge transfer type interactions was subsequently secured from femtosecond transient absorption studies covering both the visible and near-infrared regions. Furthermore, electron-pooling experiments performed in the presence of a sacrificial electron donor and a second electron acceptor revealed accumulation of one-electron reduced product upon continuous irradiation of the nanohybrids. In such experiments, the ZnPc-SWCNT (6,5) nanohybrid outperformed other nanohybrids and this suggests that this is a superior donor-acceptor system for photocatalytic applications.

Predictive and prognostic potential of volume-based metabolic variables obtained by a baseline 18F-FDG PET/CT in breast cancer with neoadjuvant chemotherapy indication

AIM

To investigate the usefulness of metabolic variables using ¹⁸F-FDG PET/CT in the prediction of neoadjuvant chemotherapy (NC) response and the prognosis in locally advanced breast cancer (LABC).

MATERIAL AND METHODS

Prospective study including 67 patients with LABC, NC indication and a baseline ¹⁸F-FDG PET/CT. After breast tumor segmentation, SUV variables (SUVmax, SUVmean and SUVpeak) and volume-based variables, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were obtained. Tumors were grouped into molecular phenotypes, and classified as responders or non-responders after completion of NC. Disease-free status (DFs), disease-free survival (DFS), and overall survival (OS) were assessed. A univariate and multivariate analysis was performed to study the potential of all variables to predict DFs, DFS, and OS.

RESULTS

Fourteen patients were classified as responders. Median±SD of DFS and OS was 43±15 and 46±13 months, respectively. SUV and TLG showed a significant correlation (p<0.005) with the histological response, with higher values in responders compared to non-responders. MTV and TLG showed a significant association with DFs (p=0.015 and p=0.038 respectively). Median, mean and SD of MTV and TLG for patients with DFs were: 8.90, 13.73, 15.10 and 33.78, and 90.54 and 144.64, respectively. Median, mean and SD of MTV and TLG for patients with non-DFs were: 16.72, 29.70 and 31.09 and 90.89, 210.98 and 382.80, respectively. No significant relationships were observed with SUV variables and DFs. Volume-based variables were significantly associated with OS and DFS, although in multivariate analysis only MTV was related to OS. No SUV variables showed an association with the prognosis.

CONCLUSION

Volume-based metabolic variables obtained with ¹⁸F-FDG PET/CT, unlike SUV based variables, were good predictors of both neoadjuvant chemotherapy response and prognosis.

1 μs broadband frequency sweeping reflectometry for plasma density and fluctuation profile measurements

Frequency swept reflectometry has reached the symbolic value of 1 μs sweeping time; this performance has been made possible, thanks to an improved control of the ramp voltage driving the frequency source. In parallel, the memory depth of the acquisition system has been upgraded and can provide up to 200 000 signals during a plasma discharge. Additional improvements regarding the trigger delay determination of the acquisition and the voltage ramp linearity required by this ultra-fast technique have been set. While this diagnostic is traditionally dedicated to the plasma electron density profile measurement, such a fast sweeping rate can provide the study of fast plasma events and turbulence with unprecedented time and radial resolution from the edge to the core. Experimental results obtained on ASDEX Upgrade plasmas are presented to demonstrate the performances of the diagnostic.

Synthesis and photophysical studies of a low-symmetry tribenzoisothiazoloporphyrazine

A new low-symmetry tetraazaporphyrin has been synthesized and characterized by 1H NMR, electronic spectroscopies and high resolution mass spectrometry. The photophysical behavior of the newly synthesized low-symmetry zinc tetraazaporphyrin ZnPz 1 has been examined and compared with that of the symmetrical tert-octylphenoxy zinc phthalocyanine ZnPc 2, by using steady-state absorption and fluorescence, cyclic voltammetry, molecular orbital calculation, and femtosecond transient absorption techniques.

Prevalence of in vitro susceptibility to carbapenems among clinical isolates of the Bacteroides fragilis group from a Colombian tertiary hospital

Clinical isolates of the Bacteroides fragilis group (n=29) were collected from patients attending a tertiary care hospital in Medellin, Colombia, during 2012 and were tested for susceptibility to four carbapenems using the Clinical and Laboratory Standards Institute (CLSI) Etest method. Overall rates of percent susceptibility were as follows: meropenem, 93.1%; imipenem, 100%; ertapenem, 96.6%; and doripenem, 93.1%. This is the first study to show rates of resistance of Bacteroides spp. to carbapenems in Colombia among a species formerly thought to be fully susceptible to this type of antimicrobial.

Urinary neutrophil gelatinase-associated lipocalin after kidney transplantation: is it a good biomarker to assess delayed graft function?

Delayed graft function (DGF) is a common complication after transplantation. Its incidence is increased among patients receiving a graft from an expanded-criteria donor. Urinary neutrophil gelatinase-associated lipocalin (uNGAL), an acute kidney injury marker, could in the first days after transplantation be an early marker of DGF. We collected urine samples from 38 renal transplant recipients on days 1, 3, 6, and 10 post-transplantation, and months 1 and 6 creatinine to determine uNGAL, serum creatinine, Cystatin C, and albumin/creatinine ratio. We divided the patients into 2 groups, based on whether they developed DGF. We observed that mean uNGAL concentrations, Cystatin C, serum creatinine, and albumin/creatinine ratio were significantly lower in the non-DGF cohort on all measured days. uNGAL at day 3 showed a positive correlation with serum creatinine at day 10 (R = 0.58; P < .00) and day 30 (R = 0.57; P = .016) as well as with the length of hospital stay (r = 0.47; P < .00). Receiver operating characteristic analyses performed to assess the potential of uNGAL to predict DGF showed an area under the curve for day 3 of uNGAL of 0.917 (confidence interval [CI], 0.79-1.00; P = .00), with an optimal cutoff level of 124 ng/mL, sensitivity of 80% (CI, 62%-97%), and specificity of 83% (62%-104%; P = .001). In the first days after transplantation, uNGAL could be an early marker of DGF, providing additional information to standard biomarkers and potentially helping clinicians to take early measures to mitigate DGF.

Failure of silicone gel breast implants: is the mechanical weakening due to shell swelling a significant cause of prostheses rupture?

Silicone gel-filled breast implants nowadays are commonly used in breast surgery. Despite the improvements carried out during the years in the device design and manufacturing technologies, the long-term reliability of such prostheses is still doubted and the phenomena involved in the prostheses failure not yet clearly defined. This study investigates rupture causes by analysing the mechanical properties of failed and intact implants in the recent generation of silicon gel breast implants. The main scope is to assess whether mechanical weakness of the shells should be considered as a major cause of breast implant rupture or, on the contrary, the prosthesis shell damage is likely due to other random factors. Some tests were performed on the shells of a wide number of explanted prostheses, to evaluate the mechanical properties as a function of prostheses status at explantation (intact/ruptured) and variable degree of swelling. A weakening of the shell mechanical properties, so as a significant difference in the ultimate strength and stiffness of intact versus ruptured prostheses, was found. This attenuation of the properties may be justified as a consequence of the shell swelling phenomenon during implantation and has to be considered as a significant mechanism for silicone gel breast implant failure.

Fast sweeping reflectometry upgrade on Tore Supra

In order to study the temporal dynamics of turbulence, the sweep time of our reflectometry has been shortened from 20 to 2 μs with 1 μs dead time. Detailed technical aspects of the upgrade are given, namely, about the stability of the ramp generation, the detection setup, and the fast acquisition module. A review of studies (velocity measurement of the turbulence, modifications of the wavenumber spectrum, radial mapping of correlation time, etc.) offered by such improvements is presented.

Redistribution of suprathermal electrons due to fishbone frequency jumps

MHD instabilities driven by fast electrons identified as fishbonelike modes have been detected on Tore Supra during lower hybrid current drive discharges. Direct experimental evidence is reported of a novel feature: the regular redistribution of suprathermal electrons toward external tokamak regions which are correlated to periodic mode frequency jumps. Sharp drops of the electron temperature time trace are factually linked to the cyclical deterioration of the fast electron confinement.

Demonstration of effective control of fast-ion-stabilized sawteeth by electron-cyclotron current drive

In a tokamak plasma, sawtooth oscillations in the central temperature, caused by a magnetohydrodynamic instability, can be partially stabilized by fast ions. The resulting less frequent sawtooth crashes can trigger unwanted magnetohydrodynamic activity. This Letter reports on experiments showing that modest electron-cyclotron current drive power, with the deposition positioned by feedback control of the injection angle, can reliably shorten the sawtooth period in the presence of ions with energies >or=0.5 MeV. Certain surprising elements of the results are evaluated qualitatively in terms of existing theory.

Self-Assembly of Methacrylic Nanostructured Copolymers Containing Polyhedral Oligomeric Silsesquioxanes

Two hybrid copolymer series obtained by free-radical copolymerization of methacrylcyclohexyl Polyhedral oligomeric silsesquioxane (POSS) with butyl methacrylate or 2-ethylhexylmethacrylate were characterized by 1H-NMR spectroscopy, gel permeation chromatography (GPC), X-rays Diffraction (XRD), differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Reactivity ratios were calculated by low yield composition data suggesting the formation of random copolymers with low probability of poly-POSS sequences. XRD studies showed the crystallization behaviour of the inorganic phase independently on the POSS content; however sample processing by solvent casting effectively hindered the copolymer self-assembling ability. DSC suggests the formation of polyphasic structures with Tg increasing with POSS content, and with endothermal peaks occurring at higher temperature. Finally TGA shows an improved thermal stability of hybrid copolymers with char yield correlated to the level of inorganic phase.

Dipyridamole promotes changes in calbindin-D28k and tyrosine hydroxylase expression in neonatal rats

BACKGROUND

Perinatal hypoxia alters the concentration of many neurochemicals in the brain, including adenosine, and promotes central nervous system (CNS) disorders in human infants such as periventricular leukomalacia or encephalopathy.

OBJECTIVE

Using the postnatal rat as a model of perinatal human development, we examined the effects of sustained increases in brain adenosine on CNS regions thought to be involved with both planning and execution of motor activity.

METHODS

To simulate hypoxia-induced changes in adenosine, Sprague-Dawley rats were injected twice daily from postnatal day (P) 3 to P14, with the adenosine uptake inhibitor dipyridamole (DIP) or the A(1) adenosine receptor agonist N(6)-cyclopentyladenosine (CPA). Vehicle-injected animals served as controls. Immunohistochemical and morphological analyses were then performed to examine the expression of calbindin D-28k (CB) and the thickness of the external granule cell layer (eGL) in the cerebellum. Additionally tyrosine hydroxylase (TH) expression in the caudate putamen and ventricular size were also examined.

RESULTS

In the cerebellum, both DIP and CPA reduced the number of CB-positive Purkinje cells as well as decreased the thickness of the eGL compared to vehicle. In the caudate putamen we found that DIP but not CPA decreased TH expression when compared to vehicle. Neither agent significantly altered ventricular size when compared to vehicle.

CONCLUSIONS

These observations suggest that elevations in brain adenosine, which can occur following hypoxia, leads to both neurochemical and cellular changes in regions of the brain which control the planning and execution of motor activity. Thus, therapeutic strategies that target brain regions most sensitive to adenosine may prevent or control at least some of the CNS damage observed following perinatal hypoxia.

Determination of effective pair interactions from the structure factor

In this work we present an efficient procedure to evaluate effective pair potentials, compatible with "experimental" structure factors, using a Monte Carlo simulation scheme. The procedure does not require the use of inverse Fourier transforms and is robust and rapidly convergent. As a test case the structure factor of liquid Selenium obtained from a Tight-Binding Molecular Dynamics simulation is inverted to obtain an effective pair potential and, as a by-product, the pair distribution function. The inversion procedure yields a pair structure in perfect agreement with the original molecular dynamics calculations and the analysis of the triplet structure and the dynamics also illustrates the limitations of the use of pair potentials in the description of liquids with strongly directional bonding, such as the covalent liquid Selenium.

Sister chromatid exchanges produced by imipramine and desipramine in mouse bone marrow cells treated in vivo

Imipramine and desipramine are two widely used tricyclic antidepressants which have shown conflicting results in regard to their in vitro genotoxic evaluation. The aim of this investigation was to determine the capacity of these compounds to induce in vivo sister-chromatid exchanges (SCEs) in mouse bone marrow cells. For each compound, the animals were organized in five groups constituted by five individuals. They were intraperitoneally (ip) administered with the test substances as follows: a negative control group treated with 0.4 ml of distilled water, a positive control group administered with cyclophosphamide (70 mg/kg), three groups treated with imipramine (7, 20 and 60 mg/kg), and three other groups treated with desipramine (2, 20 and 60 mg/kg). The general procedure included the subcutaneous implantation to each mouse of a 5-bromodesoxyuridine tablet (45 mg), and 1 h later, the administration of the chemicals involved. Twenty-one hours after the tablet implantation, the mice received colchicine, and 3 h later their femoral bone marrow was obtained in KCL, fixed, and stained with the Hoechst-Giemsa method. The results showed that both compounds were SCE inducers, starting from the second tested dose. The response of these compounds was dose-dependent, and showed that the highest tested dose increased about four times the SCE control level. The cellular proliferation kinetics was not affected by the chemicals, and the mitotic indexes were slightly diminished with the highest dose. These results indicate an in vivo genotoxic potential for both chemicals, and suggest that it is pertinent to follow their evaluation in other models.

[Adaptation of microtitration plate methods for quantification of the activity of esterases and glutathione-s-transferase in Aedes aegypti]

The detection techniques for the activity of non-specific esterases and glutathione-s-transferase in Culex quinquefasciatus were modified to detect such enzymes in Aedes aegypti(L). The optimal concentration values of substrate (saturating concentration) and the optimum reading time for reaction were determined for each enzyme by using 4 Aedes aegypti strains: one from Cuba 2 from Venezuela and one susceptible reference strain. The frequency of non-specific esterases turned out to be 0.76 in MIRANDA 0.42 in ARAGUA and 1 in SANTIAGO DE CUBA in which the highest frequency value of this mechanisms was reached. The frequency of glutathione-s-transferase mechanism was 0.45 in ARAGUA 0.043 in MIRANDA and 1 in SANTIAGO DE CUBA. For the first time in Cuba a set of biochemical techniques was available for detecting the resistance mechanisms of Aedes aegypti which made it possible to create sound foundations for the easy rapid detection of the resistance of this species the main dengue vector in the Americas.

[High esterases as mechanism of resistance to organophosphate insecticides in Aedes aegypti strains]

Five strains of Aedes aegypti L. one from Cuba and 4 from Venezuela were evaluated to determine their resistance to organophosphate insecticides (temephos, chlorpiriphos and pirimiphos methyl). In the Venezuelan strains only APURE showed resistance to temephos. In TACHIRA and MIRANDA moderate resistance values were noted (FR50 5 to 10x) for chlorpiriphos and high levels of resistance (FR > 10x) to this insecticide were found in ARAGUA. All the Venezuelan strains showed high levels of resistance to pirimiphos methyl. The Cuban strain from Santiago de Cuba revealed moderate resistance to temephos and pirimiphos methyl, but high resistance to chlorpiriphos. The results of the biochemical tests proved the presence of esterase and glutathione-s-transferase at high frequency in almost every strain. By the polyacrilamide gel electrophoresis, a strongly stained band was observed in all the strains with a Rf value of 0.779; it was named esterase A4 and was not seen in the susceptible reference strain. The meaning of this esterase in the resistance to organophosphate insecticides is yet to be determined. Resistance to these insecticides in Aedes aegypti is a serious problem for the control of this species therefore integrated management strategies were proposed to prevent or delay the appearance of this species in Cuba and Venezuela.