Near-ground effect of height on pollen exposure.

The effect of height on pollen concentration is not well documented and little is known about the near-ground vertical profile of airborne pollen. This is important as most measuring stations are on roofs, but patient exposure is at ground level. Our study used a big data approach to estimate the near-ground vertical profile of pollen concentrations based on a global study of paired stations located at different heights. We analyzed paired sampling stations located at different heights between 1.5 and 50 m above ground level (AGL). This provided pollen data from 59 Hirst-type volumetric traps from 25 different areas, mainly in Europe, but also covering North America and Australia, resulting in about 2,000,000 daily pollen concentrations analyzed. The daily ratio of the amounts of pollen from different heights per location was used, and the values of the lower station were divided by the higher station. The lower station of paired traps recorded more pollen than the higher trap. However, while the effect of height on pollen concentration was clear, it was also limited (average ratio 1.3, range 0.7-2.2). The standard deviation of the pollen ratio was highly variable when the lower station was located close to the ground level (below 10 m AGL). We show that pollen concentrations measured at >10 m are representative for background near-ground levels.

Modelling the introduction and spread of non-native species: international trade and climate change drive ragweed invasion.

Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management. However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread. We used the model to simulate the invasion of Europe by common ragweed (Ambrosia artemisiifolia), a globally invasive plant that causes serious harm as an aeroallergen and crop weed. Simulations starting in 1950 accurately reproduced ragweed's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction. Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data. The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways. We conclude that invasion models would benefit from integrating introduction processes (transport and release) with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion risk and provide useful guidance for management strategies to reduce the impacts of invasion.

Serological and molecular identification of Legionella spp. isolated from water and surrounding air samples in Italian healthcare facilities.

BACKGROUND: Legionella is an intracellular microorganism living in natural and artificial aquatic environments. Although its transmission to humans is linked to the inhalation of contaminated aerosols, there is no validated air sampling method for the control and prevention of the disease. The aim of the present study was to provide more information on the distribution of Legionella spp. in indoor environments and to determine whether the same Legionella strains are isolated from air and water samples. METHODS: Ten healthcare facilities located in seven regions of Italy were enrolled. The serological typing of Legionella spp. from water samples and the surrounding air by active and passive sampling was assessed using polyvalent and monovalent antisera. Subsequently, the strains identified as Legionella pneumophila (Lpn) underwent molecular typing by sequence-based typing (SBT) using seven genes (flaA, pilE, asd, mip, mompS, proA, and neuA). The allelic profile number was assigned using the European Working Group for Legionella Infections-SBT database. RESULTS: Lpn serogroup 6 was the most prevalent serogroup; it was found simultaneously in the air and water samples of three different healthcare facilities. In the remaining seven hospitals, Lpn serogroups 1, 6, 7, 9, and 12 were isolated exclusively from water samples. The molecular investigation showed that Lpn strains in the water and air samples of each positive healthcare facility had the same allelic profile. Strains, identified as sequence types (STs) 728 and ST 1638+ST 1324, were isolated in two respective healthcare facilities, and a new strain, identified as ST 1989, was obtained in one healthcare facility. CONCLUSION: The application of the SBT method allowed to verify the homology among Legionella strains from water samples and the surrounding air. The results showed that the same Lpn strains were present in the air and water samples, and a new Legionella strain was identified.

Variation of the group 5 grass pollen allergen content of airborne pollen in relation to geographic location and time in season.

BACKGROUND: Allergies to grass pollen are the number one cause of outdoor hay fever. The human immune system reacts with symptoms to allergen from pollen. OBJECTIVE: We investigated the natural variability in release of the major group 5 allergen from grass pollen across Europe. METHODS: Airborne pollen and allergens were simultaneously collected daily with a volumetric spore trap and a high-volume cascade impactor at 10 sites across Europe for 3 consecutive years. Group 5 allergen levels were determined with a Phl p 5-specific ELISA in 2 fractions of ambient air: particulate matter of greater than 10 µm in diameter and particulate matter greater than 2.5 µm and less than 10 µm in diameter. Mediator release by ambient air was determined in FcεRI-humanized basophils. The origin of pollen was modeled and condensed to pollen potency maps. RESULTS: On average, grass pollen released 2.3 pg of Phl p 5 per pollen. Allergen release per pollen (potency) varied substantially, ranging from less than 1 to 9 pg of Phl p 5 per pollen (5% to 95% percentile). The main variation was locally day to day. Average potency maps across Europe varied between years. Mediator release from basophilic granulocytes correlated better with allergen levels per cubic meter (r(2) = 0.80, P < .001) than with pollen grains per cubic meter (r(2) = 0.61, P < .001). In addition, pollen released different amounts of allergen in the non-pollen-bearing fraction of ambient air, depending on humidity. CONCLUSION: Across Europe, the same amount of pollen released substantially different amounts of group 5 grass pollen allergen. This variation in allergen release is in addition to variations in pollen counts. Molecular aerobiology (ie, determining allergen in ambient air) might be a valuable addition to pollen counting.

[Legionella spp. contamination in indoor air: preliminary results of an Italian multicenter study]. / La contaminazione indoor da Legionella spp: risultati preliminari di una indagine multicentrica italiana.

OBJECTIVE: To propose a standardized protocol for the evaluation of Legionella contamination in air. DESIGN: A bathroom having a Legionella contamination in water >1,000 cfu/l was selected in 10 different healthcare facilities. Air contamination was assessed by active (Surface Air System, SAS) and passive (Index of Microbial Air, IMA) sampling for 8 hours, about 1 m away from the floor and 50 cm from the tap water. Two hundred liters of air were sampled by SAS every 12 min, after flushing water for 2 min. The IMA value was calculated as the mean value of colony forming units/16 plates exposed during sampling (2 plates/hour). Water contamination was evaluated at T0, after 4 and 8 hours, according to the standard methods. RESULTS: Air contamination by Legionella was found in three healthcare facilities (one with active and two with passive sampling), showing a concomitant tap water contamination (median=40,000; range 1,100-43,000 cfu/l). The remaining seven hospitals isolated Legionella spp. exclusively from water samples (median=8,000; range 1,200-70,000 cfu/l). CONCLUSIONS: Our data suggest that environmental Legionella contamination cannot be assessed only through the air sampling, even in the presence of an important water contamination.

An overview of the studies on microbial air contamination in operating theatres and related issues over time: a useful tool for a multidisciplinary approach.

Background and aim Surgical site infection (SSI) is a major complication following surgery associated with increased morbidity and mortality, as well as increased health and not health costs. A variety of factors affect airborne contamination in operating theatres (OT). Following the Medical Research Council study showing a correlation between microbial air contamination and SSI incidence in prosthetic joint surgery ultraclean OTs have been recommended for this type of surgery, while OTs supplied by turbulent airflow plants are recommended for other types of surgery. The aim of this study was to illustrate the studies on this topic. Methods Scopus was considered for articles published until January 2023 on OTs and air contamination in article title or abstract or keywords. Many issues were deepened: "microbial", "bacterial", "fungi", "viruses", "surgical site/wound infection", "monitoring/sampling", "air changes", "behaviour", "door openings", "particles", turbulent flow", "unidirectional flow". Results Total papers published were 907 and 249 papers faced monitoring/sampling. A total of 313 papers investigated airborne bacterial contamination and 63 papers investigated fungal air contamination. There were 218 papers that have evaluated particle contamination in OTs. Many other issues were deepened. Conclusions This study shows a picture of the studies on biological air contamination in OTs and related issues over time. We think that the results of our study will provide a useful tool to increase awareness towards a better sharing of aims, approaches, and results, above all in the interest of the patients, but also of the health services of the different countries. (www.actabiomedica.it).

Air microbial sampling in operating theatres by active and passive methods: equation correlation from the GISIO-ISChIA study results and comparison with the EU GGMP recommendation, towards the definition of threshold values.

The aim of this study was to calculate the equation of correlation between the microbial air contamination values obtained by active sampling (colony-forming units per cubic metre, CFU/m3) and by passive sampling (Index of microbial air contamination, IMA), by using the data from the ISChIA study, and to compare the values obtained with the recommended limits defined by the EU Guidelines to Good Manufacturing Practice (EU GGMP), 2008, for clean areas used to manufacture sterile medicinal products. Air sampling was performed during 335 elective prosthesis procedures. Correlation between CFU/m3 and IMA values was evaluated using the Spearman test; p<0.05 was considered to indicate significance. This equation was used to calculate the IMA values corresponding to the CFU/m3 recommended threshold values by EU GGMP for the different Grades of microbial contamination. The following correlation equation was obtained: y = 1.86 + 0.12x, where "x" = cfu/m3 value and "y" = IMA value. The relationships between CFU/m3 and IMA values obtained from active and passive sampling during the ISChIA study showed to be in line to those suggested by the EU GGMP for pharmaceutical manufacturing for Grade C and D. This study shows that the EU GGMP relationship could be considered valid also for operating theatres. Both methods, active and passive samplings, can be used to evaluate microbial air quality and highlight critical situations; however, in particular during the activity, passive sampling estimating the risk posed by airborne microorganisms to the surgical wound, can be considered more relevant, and for its simplicity, economy and standardization, can be suggested for routine microbial monitoring.

An overview on the use of ultraviolet radiation to disinfect air and surfaces.

Background and aim Ultraviolet radiation (UV) is the portion of the electromagnetic spectrum of wavelengths between 200 and 400 nm divided into three bands called UVA, UVB and UVC. Due its well-described antimicrobial activity, UVC can represent a useful tool for disinfect surfaces, water, and air. The aim of this study was to illustrate the studies over time ultraviolet germicidal irradiation (UVGI) to disinfect air and surfaces. Methods Articles on Scopus published until April 14, 2023, were considered. Many issues involving UV were deepened crosschecking with e.g., "air", "surfaces", "disinfection", "bacteria", "fungi", "operating theatres". According to the case, the following variables were considered: years and related number of articles, sources of publications, subject areas, type of document published, type of journal, nationalities of the authors. Results Since 30's, 287 448 articles on UV have been published. Among UVGI, 22 159 articles covered bacteria issue, followed by fungi and viruses with about 12000 both. UVGI was addressed by 1941 and 931 articles for surfaces and air respectively. Of these, 122 were performed in operating theatres. Since 1987 works have been published on spacecraft and since 2000, on the use of UVGI robots for disinfect air and surfaces. Conclusions Our study shows the studies on UVGI and related issues. It also shows most recently perspectives about the applications e.g. during prolonged human-crewed missions on spacecrafts, to inactivate microorganisms in environments where the exchange of air is impossible.

Solar ultraviolet light collector for germicidal irradiation on the moon.

Prolonged human-crewed missions on the Moon are foreseen as a gateway for Mars and asteroid colonisation in the next decades. Health risks related to long-time permanence in space have been partially investigated. Hazards due to airborne biological contaminants represent a relevant problem in space missions. A possible way to perform pathogens' inactivation is by employing the shortest wavelength range of Solar ultraviolet radiation, the so-called germicidal range. On Earth, it is totally absorbed by the atmosphere and does not reach the surface. In space, such Ultraviolet solar component is present and effective germicidal irradiation for airborne pathogens' inactivation can be achieved inside habitable outposts through a combination of highly reflective internal coating and optimised geometry of the air ducts. The Solar Ultraviolet Light Collector for Germicidal Irradiation on the Moon is a project whose aim is to collect Ultraviolet solar radiation and use it as a source to disinfect the re-circulating air of the human outposts. The most favourable positions where to place these collectors are over the peaks at the Moon's poles, which have the peculiarity of being exposed to solar radiation most of the time. On August 2022, NASA communicated to have identified 13 candidate landing regions near the lunar South Pole for Artemis missions. Another advantage of the Moon is its low inclination to the ecliptic, which maintains the Sun's apparent altitude inside a reduced angular range. For this reason, Ultraviolet solar radiation can be collected through a simplified Sun's tracking collector or even a static collector and used to disinfect the recycled air. Fluid-dynamic and optical simulations have been performed to support the proposed idea. The expected inactivation rates for some airborne pathogens, either common or found on the International Space Station, are reported and compared with the proposed device efficiency. The results show that it is possible to use Ultraviolet solar radiation directly for air disinfection inside the lunar outposts and deliver a healthy living environment to the astronauts.

A temporally and spatially explicit, data-driven estimation of airborne ragweed pollen concentrations across Europe.

Ongoing and future climate change driven expansion of aeroallergen-producing plant species comprise a major human health problem across Europe and elsewhere. There is an urgent need to produce accurate, temporally dynamic maps at the continental level, especially in the context of climate uncertainty. This study aimed to restore missing daily ragweed pollen data sets for Europe, to produce phenological maps of ragweed pollen, resulting in the most complete and detailed high-resolution ragweed pollen concentration maps to date. To achieve this, we have developed two statistical procedures, a Gaussian method (GM) and deep learning (DL) for restoring missing daily ragweed pollen data sets, based on the plant's reproductive and growth (phenological, pollen production and frost-related) characteristics. DL model performances were consistently better for estimating seasonal pollen integrals than those of the GM approach. These are the first published modelled maps using altitude correction and flowering phenology to recover missing pollen information. We created a web page (http://euragweedpollen.gmf.u-szeged.hu/), including daily ragweed pollen concentration data sets of the stations examined and their restored daily data, allowing one to upload newly measured or recovered daily data. Generation of these maps provides a means to track pollen impacts in the context of climatic shifts, identify geographical regions with high pollen exposure, determine areas of future vulnerability, apply spatially-explicit mitigation measures and prioritize management interventions.

The scenario of the studies on ragweed (Ambrosia Sp.) and related issues from its beginning to today: a useful tool for future goals in a one health approach.

BACKGROUND AND AIM: Airborne ragweed pollen is one of the agents of respiratory allergies in our changing environment. The monitoring of pollen is essential to manage pollen allergy and to improve its forecasting methods. Moreover, the control and fight against ragweed plants is important. Aim of this study is to understand the scenario of the studies on ragweed over time. METHODS: We searched PubMed and Scopus for articles published until July 2022 reporting the words "ragweed". Articles written in all languages were included. RESULTS: Scopus was the database with the highest number of published papers. Among the papers on ragweed, the papers citing the word "allergy" were 59.4% in PubMed and 37,6% in Scopus. The subject areas more addressed were medicine, immunology, genetics/molecular biology, but agricultural/biological sciences too and, interestingly, other subjects like social sciences, art, humanistic, etc.). Among the top 40 institutions supporting research, 8 were European, 4 Asian, 1 Russian and 21 were American, the other 6 were pharmaceutical companies. CONCLUSIONS: This study shows a picture of the ragweed studies and some related subjects over time. A gap between the number of biomedical and not biomedical issues was evident. There is a need for greater involvement of institutions into support of knowledge and fight ragweed. The results will provide a useful tool to identify future goals in a global approach of ragweed related issues.

Detection of SARS-CoV-2 on hospital surfaces.

The COVID-19 pandemic, affecting 213 countries, with more than 10 million cases and over 500,000 deaths is still causing serious health, social and economic emergency worldwide. Italian Northern regions are among the most badly affected areas. Surfaces represent matrices to which particular attention should be paid for prevention and control of SARS-CoV-2 transmission. A few studies have highlighted virus presence on surfaces. We report the evidence of its presence on hospital surfaces, in a single room hosting a patient whose nose-pharyngeal swab resulted positive for SARS-CoV-2 RNA at the admission. The surfaces sampling was carried out using pre-wetted swabs followed by extraction and amplification of viral RNA by reverse Real-Time Polymerase Chain Reaction (rRT-PCR). A total of 4/15 (26.66%) surfaces were positive for SARS-CoV-2 RNA: the right bed rail, the call button, the bed trapeze bar, the stethoscope; moreover, the patient's inner surgical mask was positive, showing the emission of the virus from the patient. This study is a further confirmation that the surfaces represent a potential vehicle of transmission. This supports the need for strict adherence to hand and environmental hygiene.

The Influence of Surgical Staff Behavior on Air Quality in a Conventionally Ventilated Operating Theatre during a Simulated Arthroplasty: A Case Study at the University Hospital of Parma.

Surgical staff behavior in operating theatres is one of the factors associated with indoor air quality and surgical site infection risk. The aim of this study was to apply an approach including microbiological, particle, and microclimate parameters during two simulated surgical hip arthroplasties to evaluate the influence of staff behavior on indoor air quality. During the first hip arthroplasty, the surgical team behaved correctly, but in the second operation, behavioral recommendations were not respected. Microbiological contamination was evaluated by active and passive methods. The air velocity, humidity, temperature, and CO2 concentration were also monitored. The highest levels of microbial and particle contamination, as well as the highest variation in the microclimate parameter, were recorded during the surgical operation where the surgical team behaved "incorrectly". Turbulent air flow ventilation systems appeared more efficient than in the past and very low air microbial contamination was reached when behavior was correct. Therefore, adherence to behavioral recommendations in operating theatres is essential to not undermine the effectiveness of the heating, ventilation, and air conditioning systems and employed resources.

Passive air sampling: the use of the index of microbial air contamination.

BACKGROUND: Bioaerosol plays an important role in human life with potentially infectious, allergic and toxic effects. Active and passive methods can be used to assess microbial air contamination, but so far there is not a unanimous consensus regarding the indications about methods to be used and how to interpret the results. The passive method has been standardized by the Index of Microbial Air contamination (IMA). Classes of contamination and maximum acceptable levels of IMA have been proposed, related to different infection or contamination risks. The aim of this study was to provide information about the use of the passive sampling method, with reference to the IMA standard. METHODS: We searched PubMed and Scopus for articles published until January 2020 reporting the citation of the article by Pasquarella et al. "The index of microbial air contamination. J Hosp Infect 2000". Only studies in English language where the IMA standard was applied were considered. Studies regarding healthcare settings were excluded. RESULTS: 27 studies were analyzed; 12 were performed in Europe, 8 in Asia, 5 in Africa, 2 in America. Cultural heritage sites, educational buildings and food industries were the most common indoor monitored environments; in 8 studies outdoor air was monitored. CONCLUSIONS: This review has provided a picture of the application of standard IMA in different geographic areas and different environments at risk of airborne infection/contamination. The analysis of the results obtained, together with a wider collection of data, will provide a useful contribution towards the definition of reference limits for the various types of environments to implement targeted preventive measures.

[Fungal contamination in a University building].

BACKGROUND: It is recognized that airborne fungi can cause illnesses in humans but data on environmental exposure are still poor. The aim of this study was to evaluate the fungal airborne contamination in a university building. METHODS: The study was performed in February and May 2018; air samples were collected, before activity (on Monday) and during activity, (on Friday), both through active (CFU/m3) and passive (Index of microbial air contamination, IMA) method. Fungi were identified by using the scotch test. RESULTS: In February the median fungal contamination value decreased from 14 CFU/m3 before activity to 7 CFU/m3 during activity, while IMA median remains 0. Instead in May both increased during activity (from 87 to 140 CFU/m3; from 5.5 to 7.5 IMA). Overall values increased in May compared to February. Aspergillus spp., Penicillium spp.,  Cladosporium spp. Absidia spp. were the genera most frequently isolated in both months, while in May Chaetomium spp. e Ulocladium spp. were recovered too. CONCLUSIONS: Seasonal trend in the levels of fungal contamination of the air was observed, with a statistically significant increase in May. This study represents the first step of a wider study aimed at enhancing knowledge about air fungal contamination.

The "Patient's Empowerment rights-duty Charter": new communication tools targeted at patient and professionals in a Hematology and Bone marrow transplant center.

BACKGROUND AND AIM OF THE WORK: Empowerment is very important to keep high staff motivation and attention on patient safety. The aim of this study was to produce a "Charter of Rights-Duties for Patients' Empowerment", by developing empowerment both of patients and professionals of the Hematology and Bone marrow transplant center Unit of Parma University Hospital. METHODS: The professionals were actively involved in meetings to complete the Italian version of the SESM Empowerment Questionnaire, draft the Charter and produce some communication tools to be implemented in the Unit. RESULTS: All professionals had participated to the research. The level of empowerment in the unit, both for doctors and non-medical staff, is very high. This result, the Charter and the others communication tools are now known and shared by all. CONCLUSIONS: Stimulating empowerment seems to be a winning choice. It is important to involve professionals right away in the process because a high level of staff empowerment can generate a good field for high degree of patients' empowerment, that can increase patient safety and reduce the risk of dangerous health choices. This approach aims to increase patient safety through the collaboration of patients, volunteer associations and professionals. Communication programs must include the development of empowerment: it motivates citizens to engage and the literacy enables them to make informed and reasoned choices. General Management is now evaluating how to realize the program in each ward, discussing the importance of carefully conceptualizing this approach for the design of health interventions.

Evaluation of Air Contamination in Orthopaedic Operating Theatres in Hospitals in Southern Italy: The IMPACT Project.

Postoperative infections are a concern, especially in total knee and total hip arthroplasty. We evaluated the air quality in orthopaedic operating theatres in southeastern Italy to determine the level of bacterial contamination as a risk factor for postoperative infection. Thirty-five hospitals with operating theatres focused on total knee and total hip arthroplasty participated. We sampled the air passively and actively before surgeries began for the day (at rest) and 15 min after the surgical incision (in operation). We evaluated bacterial counts, particle size, mixed vs turbulent airflow systems, the number of doors, number of door openings during procedures and number of people in the operating theatre. We found no bacterial contamination at rest for all sampling methods, and significantly different contamination levels at rest vs in operation. We found no association between the number of people in the surgical team and bacteria counts for both mixed and turbulent airflow systems, and low bacterial loads, even when doors were always open. Overall, the air quality sampling method and type of ventilation system did not affect air quality.

[Air microbial sampling: the state of the art]. / Il campionamento microbiologico dell'aria: lo stato dell'arte.

Air microbial sampling is a subject of great interest in different fields of human activity; however, generally accepted indications, concerning both the sampling methods to be used and the interpretation of the results, are still lacking. The whole theme is greatly debated and several problems remains to be solved. The aim of this article is to provide knowledge relating to the problems associated with air microbial sampling, underlining the aspects to be considered in order to choice the sampling method on the basis of the objective of the sampling itself and on the knowledge of the characteristics and limits of the different methods.

Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study.

Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis®µ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis®µ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis®µ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis®µ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations.

Synthesis, characterization and biological activity of two new polymeric copper(II) complexes with alpha-ketoglutaric acid thiosemicarbazone.

In this paper we describe the synthesis of new copper complexes with alpha-ketoglutaric acid thiosemicarbazone. The crystal structures of the two compounds: [Cu(H(2)ct)Cl](n) [(Cu(H(2)ct)Cl)(2)] (1) and [Cu(Hct)](n).3nH(2)O (2) (H(3)ct=alpha-ketoglutaric acid thiosemicarbazone) have been determined by X-ray and spectroscopic methods. In 1 two independent copper atoms are present. Cu(1), in a nitrogen- and oxygen-bridged polymer, is a six-coordinated (4+2), Cu(2), five coordinated (4+1), is a chlorine-bridged dimer. In 2 the copper atom presents a penta-coordination, polymeric chains form layers and the -CH(2)CH(2)COO(-) groups bridge copper atoms. In 1 a monodentate and in 2 a syn-anti bidentate bridging carboxylate are present. The biological properties of 1 and 2 and also of the free ligand (H(3)ct) were tested in vitro and compared on Friend erythroleukemia cells (FLC) and on human leukemia cell lines K562 and U937. On the FLC cells the free ligand does not inhibit cell growth, but increases the DNA synthesis; complex 1 inhibits cell proliferation and increases the DNA synthesis; complex 2 inhibits cell growth, but induces a decrement of DNA synthesis and increases the reverse transcriptase activity. Regarding the human cell lines, both complexes show proliferation inhibition through an apoptosis mechanism on cell line U937, while they have no effects on the K562 line.