Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameter

Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter CAE) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R2 = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m-3) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter CMAAP). On a yearly time base the CAE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (CMAAP). Considering the seasonal behavior, higher experimental CMAAP and computed CAE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley. Overall, the agreement between the experimental CMAAP and CAE showed a root mean squared error (RMSE) of just 0.038 on the CMAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (-0.002 ± 0.455) and a high degree of correlation (R2 = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of CAE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N.

Variability of ambient air ammonia in urban Europe (Finland, France, Italy, Spain, and the UK)

This study addressed the scarcity of NH3 measurements in urban Europe and the diverse monitoring protocols, hindering direct data comparison. Sixty-nine datasets from Finland, France, Italy, Spain, and the UK across various site types, including industrial (IND, 8), traffic (TR, 12), urban (UB, 22), suburban (SUB, 12), and regional background (RB, 15), are analyzed to this study. Among these, 26 sites provided 5, or more, years of data for time series analysis. Despite varied protocols, necessitating future harmonization, the average NH3 concentration across sites reached 8.0 ± 8.9 μg/m3. Excluding farming/agricultural hotspots (FAHs), IND and TR sites had the highest concentrations (4.7 ± 3.2 and 4.5 ± 1.0 μg/m3), followed by UB, SUB, and RB sites (3.3 ± 1.5, 2.7 ± 1.3, and 1.0 ± 0.3 μg/m3, respectively) indicating that industrial, traffic, and other urban sources were primary contributors to NH3 outside FAH regions. When referring exclusively to the FAHs, concentrations ranged from 10.0 ± 2.3 to 15.6 ± 17.2 μg/m3, with the highest concentrations being reached in RB sites close to the farming and agricultural sources, and that, on average for FAHs there is a decreasing NH3 concentration gradient towards the city. Time trends showed that over half of the sites (18/26) observed statistically significant trends. Approximately 50 % of UB and TR sites showed a decreasing trend, while 30 % an increasing one. Meta-analysis revealed a small insignificant decreasing trend for non-FAH RB sites. In FAHs, there was a significant upward trend at a rate of 3.51[0.45,6.57]%/yr. Seasonal patterns of NH3 concentrations varied, with urban areas experiencing fluctuations influenced by surrounding emissions, particularly in FAHs. Diel variation showed differing patterns at urban monitoring sites, all with higher daytime concentrations, but with variations in peak times depending on major emission sources and meteorological patterns. These results offer valuable insights into the spatio-temporal patterns of gas-phase NH3 concentrations in urban Europe, contributing to future efforts in benchmarking NH3 pollution control in urban areas.

Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations

A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial-temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and babs measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC; Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m2 g-1 from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m2 g-1 from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasize the necessity of incorporating EC observations to constrain the uncertainty associated with eBC.

Aerosol source apportionment uncertainty linked to the choice of input chemical components

For a Positive Matrix Factorization (PMF) aerosol source apportionment (SA) studies there is no standard procedure to select the most appropriate chemical components to be included in the input dataset for a given site typology, nor specific recommendations in this direction. However, these choices are crucial for the final SA outputs not only in terms of number of sources identified but also, and consequently, in the source contributions estimates. In fact, PMF tends to reproduce most of PM mass measured independently and introduced as a total variable in the input data, regardless of the percentage of PM mass which has been chemically characterized, so that the lack of some specific source tracers (e.g. levoglucosan) can potentially affect the results of the whole source apportionment study. The present study elaborates further on the same concept, evaluating quantitatively the impact of lacking specific sources' tracers on the whole source apportionment, both in terms of identified sources and source contributions. This work aims to provide first recommendations on the most suitable and critical components to be included in PMF analyses in order to reduce PMF output uncertainty as much as possible, and better represent the most commons PM sources observed in many sites in Western countries. To this aim, we performed three sensitivity analyses on three different datasets across EU, including extended sets of organic tracers, in order to cover different types of urban conditions (Mediterranean, Continental, and Alpine), source types, and PM fractions. Our findings reveal that the vehicle exhaust source resulted to be less sensitive to the choice of analytes, although source contributions estimates can deviate significantly up to 44 %. On the other hand, for the detection of the non-exhaust one is clearly necessary to analyze specific inorganic elements. The choice of not analysing non-polar organics likely causes the loss of separation of exhaust and non-exhaust factors, thus obtaining a unique road traffic source, which provokes a significant bias of total contribution. Levoglucosan was, in most cases, crucial to identify biomass burning contributions in Milan and in Barcelona, in spite of the presence of PAHs in Barcelona, while for the case of Grenoble, even discarding levoglucosan, the presence of PAHs allowed identifying the BB factor. Modifying the rest of analytes provoke a systematic underestimation of biomass burning source contributions. SIA factors resulted to be generally overestimated with respect to the base case analysis, also in the case that ions were not included in the PMF analysis. Trace elements were crucial to identify shipping emissions (V and Ni) and industrial sources (Pb, Ni, Br, Zn, Mn, Cd and As). When changing the rest of input variables, the uncertainty was narrow for shipping but large for industrial processes. Major and trace elements were also crucial to identify the mineral/soil factor at all cities. Biogenic SOA and Anthropogenic SOA factors were sensitive to the presence of their molecular tracers, since the availability of OC alone is unable to separate a SOA factor. Arabitol and sorbitol were crucial to detecting fungal spores while odd number of higher alkanes (C27 to C31) for plant debris.

A PM10 chemically characterized nation-wide dataset for Italy. Geographical influence on urban air pollution and source apportionment

Urban textures of the Italian cities are peculiarly shaped by the local geography generating similarities among cities placed in different regions but comparable topographical districts. This suggested the following scientific question: can different topographies generate significant differences on the PM10 chemical composition at Italian urban sites that share similar geography despite being in different regions? To investigate whether such communalities can be found and are applicable at Country-scale, we propose here a novel methodological approach. A dataset comprising season-averages of PM10 mass concentration and chemical composition data was built, covering the decade 2005-2016 and referring to urban sites only (21 cities). Statistical analyses, estimation of missing data, identification of latent clusters and source apportionment modeling by Positive Matrix Factorization (PMF) were performed on this unique dataset. The first original result is the demonstration that a dataset with atypical time resolution can be successfully exploited as an input matrix for PMF obtaining Country-scale representative chemical profiles, whose physical consistency has been assessed by different tests of modeling performance. Secondly, this dataset can be considered a reference repository of season averages of chemical species over the Italian territory and the chemical profiles obtained by PMF for urban Italian agglomerations could contribute to emission repositories. These findings indicate that our approach is powerful, and it could be further employed with datasets typically available in the air pollution monitoring networks.

The variability of mass concentrations and source apportionment analysis of equivalent black carbon across urban Europe

This study analyzed the variability of equivalent black carbon (eBC) mass concentrations and their sources in urban Europe to provide insights into the use of eBC as an advanced air quality (AQ) parameter for AQ standards. This study compiled eBC mass concentration datasets covering the period between 2006 and 2022 from 50 measurement stations, including 23 urban background (UB), 18 traffic (TR), 7 suburban (SUB), and 2 regional background (RB) sites. The results highlighted the need for the harmonization of eBC measurements to allow for direct comparisons between eBC mass concentrations measured across urban Europe. The eBC mass concentrations exhibited a decreasing trend as follows: TR > UB > SUB > RB. Furthermore, a clear decreasing trend in eBC concentrations was observed in the UB sites moving from Southern to Northern Europe. The eBC mass concentrations exhibited significant spatiotemporal heterogeneity, including marked differences in eBC mass concentration and variable contributions of pollution sources to bulk eBC between different cities. Seasonal patterns in eBC concentrations were also evident, with higher winter concentrations observed in a large proportion of cities, especially at UB and SUB sites. The contribution of eBC from fossil fuel combustion, mostly traffic (eBCT) was higher than that of residential and commercial sources (eBCRC) in all European sites studied. Nevertheless, eBCRC still had a substantial contribution to total eBC mass concentrations at a majority of the sites. eBC trend analysis revealed decreasing trends for eBCT over the last decade, while eBCRC remained relatively constant or even increased slightly in some cities.

Seasonal and Spatial Variations of the Oxidative Properties of Ambient PM2.5 in the Po Valley, Italy, before and during COVID-19 Lockdown Restrictions

This study describes the chemical and toxicological characteristics of fine particulate matter (PM_2.5) in the Po Valley, one of the largest and most polluted areas in Europe. The investigated samples were collected in the metropolitan area of Milan during the epidemic lockdown and their toxicity was evaluated by the oxidative potential (OP), measured using ascorbic acid (OP^AA) and dithiothreitol (OP^DTT) acellular assays. The study was also extended to PM_2.5 samples collected at different sites in the Po Valley in 2019, to represent the baseline conditions in the area. Univariate correlations were applied to the whole dataset to link the OP responses with the concentrations of the major chemical markers of vehicular and biomass burning emissions. Of the two assays, OP^AA was found mainly sensitive towards transition metals released from vehicular traffic, while OP^DTT towards the PM carbonaceous components. The impact of the controlling lockdown restrictions on PM_2.5 oxidative properties was estimated by comparing the OP values in corresponding time spans in 2020 and 2019. We found that during the full lockdown the OP^AA values decreased to 80-86% with respect to the OP data in other urban sites in the area, while the OP^DTT values remained nearly constant.

Rice diversity panel provides accurate genomic predictions for complex traits in the progenies of biparental crosses involving members of the panel

KEY MESSAGE

Rice breeding programs based on pedigree schemes can use a genomic model trained with data from their working collection to predict performances of progenies produced through rapid generation advancement. So far, most potential applications of genomic prediction in plant improvement have been explored using cross validation approaches. This is the first empirical study to evaluate the accuracy of genomic prediction of the performances of progenies in a typical rice breeding program. Using a cross validation approach, we first analyzed the effects of marker selection and statistical methods on the accuracy of prediction of three different heritability traits in a reference population (RP) of 284 inbred accessions. Next, we investigated the size and the degree of relatedness with the progeny population (PP) of sub-sets of the RP that maximize the accuracy of prediction of phenotype across generations, i.e., for 97 F5-F7 lines derived from biparental crosses between 31 accessions of the RP. The extent of linkage disequilibrium was high (r 2 = 0.2 at 0.80 Mb in RP and at 1.1 Mb in PP). Consequently, average marker density above one per 22 kb did not improve the accuracy of predictions in the RP. The accuracy of progeny prediction varied greatly depending on the composition of the training set, the trait, LD and minor allele frequency. The highest accuracy achieved for each trait exceeded 0.50 and was only slightly below the accuracy achieved by cross validation in the RP. Our results thus show that relatively high accuracy (0.41-0.54) can be achieved using only a rather small share of the RP, most related to the PP, as the training set. The practical implications of these results for rice breeding programs are discussed.

Results of an interlaboratory comparison of analytical methods for quantification of anhydrosugars and biosugars in atmospheric aerosol

An interlaboratory comparison was performed to evaluate the analytical methods for quantification of anhydrosugars - levoglucosan, mannosan, galactosan - and biosugars - arabitol, glucose and mannitol - in atmospheric aerosol. The performance of 10 laboratories in Italy currently involved in such analyses was investigated on twenty-six PM (particulate matter) ambient filters, three synthetic PM filters and three aqueous standard solutions. An acceptable interlaboratory variability was found, determined as the mean relative standard deviation (RSD%) of the results from the participating laboratories, with the mean RSD% values ranging from 25% to 46% and decreasing with increasing sugar concentration. The investigated methods show good accuracy, evaluated as the percentage error (ε%) related to mean values, since method biases ranged within ±20% for most of the analytes measured in the different laboratories. The detailed investigation (ANOVA analysis at p < 0.05) of the contribution of each laboratory to the total variability and the measurement accuracy shows that comparable results are generated by the different methods, despite the great diversity in terms of extraction conditions, chromatographic separation - more recent LC (liquid chromatography) and EC (exchange chromatography) methods compared to more widespread GC (gas chromatography) - and detection systems, namely PAD (pulsed amperometric detection) or mass spectrometry.

Spatial and temporal variability of carbonaceous aerosols: Assessing the impact of biomass burning in the urban environment

Biomass burning (BB) is a significant source of atmospheric particles in many parts of the world. Whereas many studies have demonstrated the importance of BB emissions in central and northern Europe, especially in rural areas, its impact in urban air quality of southern European countries has been sparsely investigated. In this study, highly time resolved multi-wavelength absorption coefficients together with levoglucosan (BB tracer) mass concentrations were combined to apportion carbonaceous aerosol sources. The Aethalometer model takes advantage of the different spectral behavior of BB and fossil fuel (FF) combustion aerosols. The model was found to be more sensitive to the assumed value of the aerosol Ångström exponent (AAE) for FF (AAE_ff) than to the AAE for BB (AAE_bb). As result of various sensitivity tests the model was optimized with AAE_ff=1.1 and AAE_bb=2. The Aethalometer model and levoglucosan tracer estimates were in good agreement. The Aethalometer model was further applied to data from three sites in Granada urban area to evaluate the spatial variation of CM_ff and CM_bb (carbonaceous matter from FF or BB origin, respectively) concentrations within the city. The results showed that CM_bb was lower in the city centre while it has an unexpected profound impact on the CM levels measured in the suburbs (about 40%). Analysis of BB tracers with respect to wind speed suggested that BB was dominated by sources outside the city, to the west in a rural area. Distinguishing whether it corresponds to agricultural waste burning or with biomass burning for domestic heating was not possible. This study also shows that although traffic restrictions measures contribute to reduce carbonaceous concentrations, the extent of the reduction is very local. Other sources such as BB, which can contribute to CM as much as traffic emissions, should be targeted to reduce air pollution.

Spatial and temporal variability of carbonaceous aerosols: Assessing the impact of biomass burning in the urban environment

Biomass burning (BB) is a significant source of atmospheric particles in many parts of the world. Whereas many studies have demonstrated the importance of BB emissions in central and northern Europe, especially in rural areas, its impact in urban air quality of southern European countries has been sparsely investigated. In this study, highly time resolved multi-wavelength absorption coefficients together with levoglucosan (BB tracer) mass concentrations were combined to apportion carbonaceous aerosol sources. The Aethalometer model takes advantage of the different spectral behavior of BB and fossil fuel (FF) combustion aerosols. The model was found to be more sensitive to the assumed value of the aerosol Ångström exponent (AAE) for FF (AAE_ff) than to the AAE for BB (AAE_bb). As result of various sensitivity tests the model was optimized with AAE_ff=1.1 and AAE_bb=2. The Aethalometer model and levoglucosan tracer estimates were in good agreement. The Aethalometer model was further applied to data from three sites in Granada urban area to evaluate the spatial variation of CM_ff and CM_bb (carbonaceous matter from FF or BB origin, respectively) concentrations within the city. The results showed that CM_bb was lower in the city centre while it has an unexpected profound impact on the CM levels measured in the suburbs (about 40%). Analysis of BB tracers with respect to wind speed suggested that BB was dominated by sources outside the city, to the west in a rural area. Distinguishing whether it corresponds to agricultural waste burning or with biomass burning for domestic heating was not possible. This study also shows that although traffic restrictions measures contribute to reduce carbonaceous concentrations, the extent of the reduction is very local. Other sources such as BB, which can contribute to CM as much as traffic emissions, should be targeted to reduce air pollution.

Emissions from the combustion of eucalypt and pine chips in a fluidized bed reactor

Interest in renewable energy sources has increased in recent years due to environmental concerns about global warming and air pollution, reduced costs and improved efficiency of technologies. Under the European Union (EU) energy directive, biomass is a suitable renewable source. The aim of this study was to experimentally quantify and characterize the emission of particulate matter (PM2.5) resulting from the combustion of two biomass fuels (chipped residual biomass from pine and eucalypt), in a pilot-scale bubbling fluidized bed (BFB) combustor under distinct operating conditions. The variables evaluated were the stoichiometry and, in the case of eucalypt, the leaching of the fuel. The CO and PM2.5 emission factors were lower when the stoichiometry used in the experiments was higher (0.33±0.1 g CO/kg and 16.8±1.0 mg PM2.5/kg, dry gases). The treatment of the fuel by leaching before its combustion has shown to promote higher PM2.5 emissions (55.2±2.5 mg/kg, as burned). Organic and elemental carbon represented 3.1 to 30 wt.% of the particle mass, while carbonate (CO3(2-)) accounted for between 2.3 and 8.5 wt.%. The particulate mass was mainly composed of inorganic matter (71% to 86% of the PM2.5 mass). Compared to residential stoves, BFB combustion generated very high mass fractions of inorganic elements. Chloride was the water soluble ion in higher concentration in the PM2.5 emitted by the combustion of eucalypt, while calcium was the dominant water soluble ion in the case of pine.

Lipid and protein oxidation products, antioxidant status and vascular complications in poorly controlled type 2 diabetes

The inter-relationships between glycaemic control, the progression of diabetes-related vascular complications, oxidative/antioxidative status and inflammation, have not been fully understood. We measured malondialdehyde (MDA) and carbonyl residues, C-reactive protein (CRP) and antioxidant systems by means of ferric reducing ability of plasma (FRAP) and superoxide dismutase (SOD) activity, in well controlled and poorly controlled type 2 diabetic patients without complications (NC) and in poorly controlled patients with microvascular (MicroVC) and with both micro- and macrovascular complications (Micro+Macro VC). All poorly controlled diabetic patients showed higher MDA and carbonyl residues compared to well controlled NC, as did those with Micro+Macro VC compared to poorly controlled NC. The higher CRP and SOD activity levels reached significance in Micro VC and Micro+Macro VC groups. FRAP decreased only in poorly controlled NC compared to well controlled NC (p<0.05). Glycated hamemoglobin (HbA1c) levels were positively correlated with MDA (p<0.05) and CRP (p<0.001) and inversely associated with FRAP (p<0.05) and SOD (p=0.06). An increase in MDA or carbonyl residues could be a marker of high risk for complications in patients with poorly controlled diabetes and they should be considered for monitoring the effectiveness of drug treatment.

Adiponectin in outpatients with coronary artery disease: independent predictors and relationship with heart failure

BACKGROUND AND AIMS

Chronic heart failure (HF) is characterised by a neurohormonal dysfunction associated with chronic inflammation. A role of metabolic derangement in the pathophysiology of HF has been recently reported. Adiponectin, an adipose-tissue-derived cytokine, seems to play an important role in cardiac dysfunction. We investigated the variation of circulating adiponectin in patients with coronary artery disease (CAD), with or without HF, in order to identify its independent predictors.

METHODS AND RESULTS

A total of 107 outpatients with CAD were enrolled in the study and divided into three groups: CAD without left ventricular systolic dysfunction (group 1); CAD with left ventricular dysfunction without HF symptoms (group 2) and CAD with overt HF (group 3). Plasma adiponectin was determined by enzyme-linked immunosorbent assay. Adiponectin concentrations increased progressively from group 1 (7.6 ± 3.6 ng ml⁻¹) to group 2 (9.1 ± 6.7 ng ml⁻¹) and group 3 (13.7 ± 7.6 ng ml⁻¹), with the difference reaching statistical significance in group 3 versus 1 and 2 (p < 0.001). A multivariable model of analysis demonstrated that the best predictors of plasma adiponectin were body mass index, N-terminal pro-brain natriuretic peptide and high-density lipoprotein cholesterol. However, even after adjusting for all three independent predictors, the increase of adiponectin in group 3 still remained statistically significant (p = 0.015).

CONCLUSION

Our data confirm the rise of adiponectin in overt HF. The levels of circulating adipokine seem to be mainly predicted by the metabolic profile of patients and by biohumoral indicators, rather than by clinical and echocardiographic indexes of HF severity.

Fricke gel dosimetry in boron neutron capture therapy

Gel dosimetry allows three-dimensional (3D) measurement of absorbed dose in tissue-equivalent dosemeter phantoms. Gel phantoms are imaged using optical techniques. In neutron capture therapy (NCT), properly designed gel dosemeters can give 3D dose distributions, due to the various components of the secondary radiation, in phantoms exposed in the thermal or epithermal column of a nuclear reactor. In addition to the therapeutic dose arising from the reaction 10B(n,alpha)7Li, the other dose components are also obtainable, i.e. the gamma dose (due to reactor background and to the reaction 1H(n,gamma)2H of thermal neutrons with hydrogen, the dose due to protons emitted in the reaction 14N(n,p)14C of thermal neutrons with nitrogen and the dose due to recoil protons resulting from elastic scattering of epithermal neutrons.

Gamete intrafallopian transfer: prospective randomized comparison between hysteroscopic and laparoscopic transfer techniques

OBJECTIVE

To test the efficiency and overall acceptability of hysteroscopic GIFT when compared with laparoscopic GIFT.

DESIGN

We performed a randomized comparison between these techniques as regards pregnancy rate (PR), implantation rate, miscarriage rate, and ectopic pregnancy rate (ectopic PR).

SETTING

All patients were enrolled for GIFT procedures in our Reproductive Medicine Unit.

PATIENTS

We enrolled 133 patients showing documented tubal patency at a previous diagnostic laparoscopy.

INTERVENTIONS

Gonadotropin-releasing hormone analog and FSH were administered to induce superovulation in all patients, who were then randomized for hysteroscopic GIFT or laparoscopic GIFT. Laparoscopic GIFT was performed under general anesthesia while, during hysteroscopic GIFT, oocyte retrievals were transvaginal ultrasound guided and transfers were performed by cannulating tubal ostia after hysteroscopic visualization.

MAIN OUTCOME MEASURE

The efficacy was evaluated comparing PR, implantation rate, miscarriage rate, and ectopic PR.

RESULTS

Pregnancy rate and implantation rate of hysteroscopic GIFT procedures (29.8% and 9%, respectively) are not significantly different from those obtained with laparoscopic GIFT (43.3% and 14%).

CONCLUSIONS

Hysteroscopic GIFT is safe and easy and quick to perform. Moreover, it does not require hospital admission, general anesthesia, or the operating theater, reducing costs and assuring advantages in terms of low psychophysical involvement and repeatability.

Comparison between depot leuprorelin and daily buserelin in IVF

OBJECTIVES

To compare the effects of depot and daily forms of GnRH analogs in IVF programs.

METHODS

One hundred seventeen patients undergoing IVF, with no severe male factor, were randomized between two treatment groups. Pituitary desensitization was obtained in group 1 (60 patients) with a single IM injection of leuprorelin (3.75 mg), and in group 2 (57 patients) with buserelin (0.3 mg SC twice daily). In a subgroup of 10 patients (5 for the depot form and 5 for the daily form) several GnRH tests were performed to investigate pituitary desensitization.

RESULTS

No differences were found in the time to reach desensitization. Resumption of pituitary activity occurred in 7 days with the daily form and in about 2 months with the depot form. No significant differences were found in the stimulation pattern, oocyte quality, percentage of fertilization. The pregnancy rate per transfer was slightly, but not significantly, better in the depot group (29.4% vs 25.9%). Implantation rate (11.9% vs 12.3%) and the percentage of miscarriages (26.6% vs 28.5%) were similar.

CONCLUSION

Depot and daily forms of GnRH analogs are equally effective in superovulation induction for IVF. Considering improved patient compliance and preference, depot forms are advantageous.

Transfusion-dependent homozygous beta-thalassaemia major: successful twin pregnancy following in-vitro fertilization and tubal embryo transfer

Homozygous beta-thalassaemia (thalassaemia major) is a severe, transfusion-dependent anaemia that also causes infertility due to endocrine impairment. Very few pregnancies are reported among such patients and there is only one report in the literature referring to a pregnancy achieved with ovulation induction and intra-uterine insemination. We report here the first successful twin pregnancy following in-vitro fertilization and tubal embryo transfer in a transfusion-dependent homozygous beta-thalassaemic woman with an oligoasthenozoospermic partner. Prior to ovarian stimulation, desferrioxamine was discontinued due to potential fetotoxicity. Pre-gestational transfusional and chelating therapies were resumed after delivery. In such patients, ovulation induction and assisted reproductive techniques appear crucial in achieving pregnancy with concurrent haematological balance without desferrioxamine administration.