SSRIs in the course of COVID-19 pneumonia: Evidence of effectiveness of antidepressants on acute inflammation. A retrospective study.

INTRODUCTION: Relationships between inflammation and mood have been observed in terms of pro-inflammatory effects induced by depressive conditions and, in parallel, by an antidepressant-induced favorable effect on the recovery of inflammatory states. Selective serotonin reuptake inhibitor (SSRI) drugs were hypothesized to improve the prognosis of COVID-19 pneumonia, a typical acute inflammation, in terms of decreased mortality rate and pro-inflammatory cytokine serum levels. METHODS: The medical records of COVID-19 pneumonia inpatients at Careggi University Hospital (Florence) were analyzed for prognosis and Interleukin 6 (IL-6) after admission for over a period of 22 months. Medical records of patients treated at admission and not discontinued until discharge with an SSRI or with vortioxetine were identified. Two groups, one treated with antidepressants, the other not treated, were evaluated according to the mentioned parameters. Multiple linear regression and logistic regression were performed. RESULTS: The entire sample composed of 1236 records (recovered patients 77.1%, deceased patients 22.9%). The treated group (n = 107) had a better prognosis than the untreated group in spite of age and comorbidity both being greater than in the untreated group. Correspondingly, IL-6 levels in the treated group were significantly lower (p < 0.01) than the levels in the untreated group, in every comparison. CONCLUSIONS: Outcomes of this study support the hypothesis of the favorable influence of some antidepressants on the prognosis of COVID-19, possibly mediated by IL-6 modulation. Reduction in acute inflammation induced by the action of antidepressants was confirmed.

Update on Percutaneous Treatment for HFrEF: A Great Armamentarium for a Poor Ventricular Function.

Pharmacological treatment is the cornerstone therapy of heart failure with reduced ejection fraction (HFrEF). In addition, several percutaneous techniques have been developed to treat symptomatic patients, with specific heart failure (HF) phenotypes (e.g., valvular heart disease) that require non-pharmacological treatment. Given their prognostic relevance, it is imperative to deliver high-level patient care. This review provides a clinical overview on the available data regarding transcatheter devices in the armamentarium of contemporary interventional cardiologists, focusing on the clinical and anatomical selection criteria.

Transcatheter aortic valve implantation with the novel-generation Navitor device: Procedural and early outcomes.

Transcatheter aortic valve implantation (TAVI) has proved beneficial in patients with severe aortic stenosis, especially when second-generation devices are used. We aimed at reporting our experience with Navitor, a third-generation device characterized by intrannular, large cell, and cuffed design, as well as high deliverability and minimization of paravalvular leak. Between June and December 2021, a total of 39 patients underwent TAVI with Navitor, representing 20% of all TAVI cases. Mean age was 80.0 ± 6.7 years, and 14 (36.8%) women were included. Severe aortic stenosis was the most common indication to TAVI (37 [97.4%] cases), whereas 2 (5.3%) individuals were at low surgical risk. Device and procedural success was obtained in all patients, with a total hospital stay of 6.6 ± 4.5 days. One (2.9%) patient required permanent pacemaker implantation, but no other hospital events occurred. At 1-month follow-up, a cardiac death was adjudicated in an 87-year-old man who had been at high surgical risk. Echocardiographic follow-up showed no case of moderate or severe aortic regurgitation, with mild regurgitation in 18 (47%), and none or trace regurgitation in 20 (53%). The Navitor device, thanks to its unique features, is a very promising technology suitable to further expand indications and risk-benefit profile of TAVI.

Glycoprotein IIb/IIIa Inhibitors May Modulate the Clinical Benefit of Radial Access as Compared to Femoral Access in Primary Percutaneous Coronary Intervention: A Meta-Regression and Meta-Analysis of Randomized Trials.

OBJECTIVES: Several randomized controlled trials (RCTs) consistently reported better clinical outcomes with radial as compared to femoral access for primary percutaneous coronary intervention (PCI). Nevertheless, heterogeneous use of potent antiplatelet drugs, such as Gp IIb/IIIa inhibitors (GPI), across different studies could have biased the results in favor of radial access. We performed an updated meta-analysis and meta-regression of RCTs in order to appraise whether the use of GPI had an impact on pooled estimates of clinical outcomes according to vascular access. METHODS: We computed pooled estimates by the random-effects model for the following outcomes: mortality, major adverse cardiovascular events (death, myocardial infarction, stroke, and target vessel revascularization), and major bleedings. Additionally, we performed meta-regression analysis to investigate the impact of GPI use on pooled estimates of clinical outcomes. RESULTS: We analyzed 14 randomized controlled trials and 11090 patients who were treated by radial (5497) and femoral access (5593), respectively. Radial access was associated with better outcomes for mortality (risk difference 0.01 (0.00, 0.01), p=0.03), MACE (risk difference 0.01 (0.00, 0.02), p=0.003), and major bleedings (risk difference 0.01 (0.00, 0.02), p=0.02). At meta-regression, we observed a significant correlation of mortality with both GPI use (p=0.011) and year of publication (p=0.0073), whereas no correlation was observed with major bleedings. CONCLUSIONS: In this meta-analysis, the use of radial access for primary PCI was associated with better clinical outcomes as compared to femoral access. However, the effect size on mortality was modulated by GPI rate, with greater benefit of radial access in studies with larger use of these drugs.

342 Impact of temporary traffic bans on the risk of acute coronary syndromes in a large metropolitan area.

Aims: Strong epidemiologic evidence has highlighted the role of pollution, on top of adverse climate features, as a novel cardiovascular risk factor. However, mechanistic proof that reducing pollution may be beneficial to prevent atherothrombotic events is limited. We aimed at appraising the impact of temporary traffic bans in a large metropolitan area on the risk of acute coronary syndromes. Methods and results: Aggregate and anonymized data from 15 tertiary cardiac care centers were obtained detailing pre-coronarivus disease 2019 (COVID-19) daily cases of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), including those treated with percutaneous coronary intervention (PCI). Data on pollutants and climate were sought for the same days. Mixed level regression was used to compare the week before vs. after the traffic ban (Fortnight analysis), the 3 days before vs. after (Weekly analysis) and the Sunday before vs. after (Sunday analysis). A total of 8 days of temporary traffic bans were included, occurring between 2017 and 2020, totaling 802 STEMI and 1196 NSTEMI in the Fortnight analysis, 382 STEMI and 585 in the Weekly analysis, and 148 STEMI and 210 NSTEMI in the Sunday analysis. Fortnight and Sunday analysis did not disclose a significant impact of traffic ban on STEMI or NSTEMI (all P > 0.05). Conversely, Weekly analysis showed non-significant changes for STEMI but a significant decrease in daily NSTEMI when comparing the 3 days before the traffic ban with the ban day (P = 0.043), as well as the 3 days before vs. the 3 days after the ban (P = 0.025). No statistically significant effect of traffic ban was found at Fortnight, Weekly or Sunday analyses for daily mean concentrations of benzene, carbon monoxide, nitric oxide, nitrogen dioxide, ozone, sulfur dioxide, particulate matter (PM) <2.5 µm or PM < 10 µm (all P > 0.05). However, minimum daily concentrations showed a significant reduction of ozone during the ban in comparison to the week preceding it (P = 0.034), nitric oxide during the ban in comparison to the 3 days preceding it (P = 0.046), and an increase in benzene during the ban in comparison to the Sunday before (P = 0.039). Conclusion: Temporary traffic bans may favorably reduce coronary atherothrombotic events, and in particular NSTEMI, even if not globally and immediately impacting on environmental pollution. Further controlled studies are required to confirm and expand this hypothesis-generating results.

Cryptic severe Plasmodium falciparum malaria in a Moroccan man living in Tuscany, Italy, August 2018.

In August 2018 a Moroccan man living in Tuscany developed Plasmodium falciparum malaria. The patient declared having not recently visited any endemic country, leading to diagnostic delay and severe malaria. As susceptibility to P. falciparum of Anopheles species in Tuscany is very low, and other risk factors for acquiring malaria could not be completely excluded, the case remains cryptic, similar to other P. falciparum malaria cases previously reported in African individuals living in Apulia in 2017.

Transfemoral approach with systematic use of FemoSeal™ closure device compared to transradial approach in primary angioplasty.

OBJECTIVES: To compare the incidence of major adverse cardiac and cerebrovascular events (MACCE) and thrombolysis in myocardial infarction (TIMI) bleedings in primary percutaneous coronary intervention (pPCI) performed through transradial approach (TRA) or transfemoral approach (TFA) with systematic closure by FemoSeal™. BACKGROUND: Although the risk of bleeding can be reduced using vascular closure devices (VCD), there are few data comparing TRA and TFA with VCD, particularly in the setting of pPCI. METHODS: we included in this retrospective registry 777 patients who underwent pPCI at two centers from years 2010 to 2013. Exclusion criteria were implantation of intra-aortic balloon pump and achievement of femoral hemostasis by other means than FemoSeal™. We performed propensity-score matching and multivariate analysis to adjust for clinical and procedural confounders. RESULTS: We enrolled 511 patients in TRA group and 266 in TFA group. Both in the general population and in the propensity-matched population, the incidence of MACCE was comparable in TRA vs. TFA patients (3.5 vs. 3.4% and 4.4 vs. 2.6%, respectively; P = ns). On the contrary, we observed a higher incidence of TIMI bleedings in TFA vs. TRA patients (5.6 vs. 2.2% in the general population and 6.6 vs. 1.3% in the propensity-matched population; P < 0.05); this difference was mainly driven by TIMI major bleedings. TFA was an independent predictor of bleeding at multivariate analysis. CONCLUSIONS: In pPCI the rate of TIMI major bleedings was higher in TFA with closure by FemoSeal™ as compared to TRA, whereas the rates of minor bleedings and of MACCE were similar.

Future of left atrial appendage interventions.

Percutaneous left atrial appendage occlusion (LAAO), currently recognized as a procedure with relatively low risk, is increasingly being adopted in clinical practice. However, due to the preventive nature of the procedure and the necessity to compare it with newer and safer oral anticoagulants, further optimization is required to address remaining challenges. These latter include acquiring comprehensive data on safety and efficacy, establishing standardized pre-procedural planning, and simplifying procedural process. Consequently, we have provided an overview that encompasses future opportunities for enhancing procedural safety and efficacy, thereby establishing LAAO as the mainstream strategy for stroke and systemic embolism prevention in patients with atrial fibrillation and absolute contraindications to anticoagulant drugs.

Acute Kidney Injury in Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention: The Role of Vascular Access Site.

Background: in patients undergoing percutaneous coronary interventions (PCI), radial access should be favoured over femoral access as it reduces the risk of vascular complications and bleeding. Furthermore, a preventive role of radial access in the occurrence of acute kidney injury (AKI), mainly mediated by the reduction of bleeding and cholesterol crystal embolization into renal circulation, has been investigated in several studies, yielding conflicting results. Methods: we designed a retrospective study to appraise the effect of the use of a vascular access site on the occurrence of AKI in a cohort of 633 patients with acute myocardial infarction treated by PCI at our centre from 2018 to 2020. Results: after propensity score adjustment, radial access was associated with a reduced, albeit statistically not significant, incidence of AKI (14.7% vs. 21.0%; p = 0.06) and major bleeding (12.5% vs. 18.7%; p = 0.04) as compared to femoral access. At multivariate analysis, femoral access was an independent predictor of AKI, together with in-hospital occurrence of BARC 3-5 bleeding, Killip class >1 at presentation, female gender, baseline eGFR <60 mL/min, and baseline haemoglobin <12 g/dL. Conclusions: although limited by the observational design, our study supports the hypothesis that radial access may exert a protective role on the occurrence of AKI in patients with acute myocardial infarction undergoing PCI.

Exposure to polycyclic aromatic hydrocarbons in women from Poland, Serbia and Italy--relation between PAH metabolite excretion, DNA damage, diet and genotype (the EU DIEPHY project).

Exposure of the general population to polycyclic aromatic hydrocarbons (PAH) is ubiquitous. The aim of this study was to analyze biomarkers associated with the uptake of PAH in 428 non-smoking women from Lodz (Poland), Viterbo (Italy), Belgrade (Serbia) and from the Pancevo area, where the petrochemical complex was destroyed by the air raids in 1999. Urinary excretion of PAH metabolites was lowest in Italian women, intermediary for Serbian and highest in Polish women, who predominantly excreted hydroxy phenanthrenes as metabolites of phenanthrene. Bulky DNA adduct levels were highest in Italian and Polish women. Genotype or PAH ambient air levels could not explain the dissimilarities between the study groups with respect to biomarker patterns, which probably reflected differences in life style-associated factors.

Effect of blueberries (BB) on micronuclei induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 7,12-dimethylbenz(a)anthracene (DMBA) in mammalian cells, assessed in in vitro and in vivo assays.

The protective effect of blueberry (BB) on the clastogenic effects of MNNG and DMBA was evaluated with the induced micronucleus (MN) frequency as a biomarker, both in vitro and in vivo. Human hepatoma HepG2 cells, which contain most of the metabolic activating enzymes was used for the in vitro test. MN frequencies were determined in binucleated cells generated by blocking cytokinesis by use of cytochalasin-B. The MN frequency in vivo was determined in polychromatic erythrocytes (PCEs) from the bone marrow of treated mice. BB by itself was not toxic both in vivo and in vitro. There was no evidence of a potential physico-chemical interaction between BB and the test carcinogens in vitro. Pre-treatment with BB reduced the MN frequency induced by MNNG. But, simultaneous treatment and post-treatment with BB did not affect the frequency of MNNG-induced MN. BB did not affect the frequency of DMBA-induced MN in vitro under any test condition. Under in vivo conditions, BB reduced the frequencies of MNNG- and DMBA-induced MN in PCEs, but in the case of the protective effect of BB against DMBA a dramatic reduction in the percentage of PCEs was observed, suggesting increased cytotoxicity.

In-hospital outcomes of Portico transcatheter aortic valve replacement with the FlexNav as compared to the first-generation delivery system.

Introduction: Technological advancements in transcatheter heart valve platforms are essential in order to achieve high standards of efficacy and safety in transcatheter aortic valve replacement (TAVR). Aim: To evaluate the performance of the new version of the Portico valve delivery system (FlexNav) as compared to the first-generation device. Material and methods: In this single-center, observational study consecutive patients undergoing Portico valve implantation with the new FlexNav delivery system (DS) were compared with patients treated with the first-generation delivery system (1st gen DS). In-hospital outcomes were self-adjudicated according to the Valve Academic Research Consortium-3 definition. Results: Fifty patients were included in this study; 22 were treated with the FlexNav DS and the remaining patients with the 1st gen DS. Clinical characteristics were similar between groups, except for older age (82.6 ±3.6 vs. 80.7 ±3.8; p = 0.07) and higher prevalence of female gender (68.2% vs. 39.3%; p = 0.04) in the FlexNav DS group as compared to the 1st gen DS group, respectively. We observed similar rates of procedural success but higher rate of moderate-to-severe paravalvular leak in the 1st gen DS as compared to FlexNav DS group (28.6% vs. 4.6%; p = 0.03); major vascular complications were reduced, although not significantly, in the FlexNav DS as compared to the 1st gen DS group (4.5% vs. 10.7%; p = 0.64). Conclusions: Our data suggest that the FlexNav DS, thanks to its lower profile and enhanced stability during valve deployment, might be associated with reduced rates of vascular complications and moderate to severe paravalvular leak, thus improving procedural results.

Lipoprotein(a) and the risk of recurrent events in patients with acute myocardial infarction treated by percutaneous coronary intervention.

BACKGROUND: The role of lipoprotein(a) (Lp[a]) in risk stratification following an acute myocardial infarction (AMI) is still debated. We aimed to investigate whether elevated Lp(a) levels in patients with AMI treated by percutaneous coronary intervention (PCI) are associated with worse outcomes. METHODS: We designed a retrospective registry including patients with AMI undergoing PCI. The occurrence of major adverse cardiac and cerebrovascular events (MACCE), defined as death from cardiovascular causes, recurrent myocardial infarction, unplanned coronary revascularization and stroke, was assessed at follow-up and compared between patients with high (≥30 mg/dL) and low (<30 mg/dL) Lp(a) levels. Cox proportional hazard analysis was performed in order to assess independent predictors of MACCE. RESULTS: During a 3-year period (2018-2020) we identified 634 patients with AMI treated by PCI and known Lp(a) blood levels; follow-up visits were performed in 414 patients (median length 29 months [19-38]). Median Lp(a) level was 18 mg/dL [8-42]. The incidence of MACCE was significantly higher in high as compared to low Lp(a) group (log-rank P=0.018). The following independent predictors were identified at multivariate Cox regression: Lp(a) ≥30 mg/dL (HR 1.82 [95% CI 1.04-3.19], peripheral artery disease (HR 4.62 [95% CI 2.50-8.54]), number of diseased coronary vessels (HR 1.51 [95% 1.03-2.24] and presence of a coronary chronic total occlusion at coronary angiography (HR 3.46 [95% CI 1.77-6.76]). CONCLUSIONS: in this study, Lp(a) values ≥30 mg/dL were associated to worse outcomes in patients with AMI receiving PCI. Lp(a) could represent a useful tool to identify patients at high risk of recurrent events.

Can selective serotonin reuptake inhibitors/serotonin and norepinephrine reuptake inhibitor antidepressants decrease the "cytokine storm" in the course of COVID-19 pneumonia?

BACKGROUND: Lots of research has been conducted to fight COVID-19 since the outbreak of the pandemic in 2020. The role of "cytokine storm" in the pathogenesis of COVID-19 pneumonia is well known. Relationship between interleukins and depression is still subject matter of the research, but a correlation between interleukin-6 and depressive disorders is proven by now. The aim of this study is to verify differences among interleukin-6 blood levels of inpatients treated with selective serotonin reuptake inhibitors and/or serotonin and norepinephrine reuptake inhibitor before and during hospitalization and of inpatients not treated with these drugs. METHODS: This is an observational study performed during the first wave of SARS Cov-2 pandemic in Italy for three months. The hospitalized patients of Internal Medicine wards and Infectious and Tropical Diseases ward of Azienda Ospedaliero-Universitaria Careggi of Florence for COVID-19 pneumonia have been divided into two subgroups (treated / not treated with antidepressants). Patients admitted to Intensive Care Unit previously have been excluded. Each patient has been evaluated concerning demographic, clinical and therapeutic features. The first dosage of interleukin-6 detected during hospitalization has been noticed. RESULTS: The entire sample included 402 patients and 8.5% (N.=34) had been treated with an antidepressant of the two considered categories before admission until discharge from hospital. Significant lower levels of interleukin-6 of recovered patients of the treated subgroup have been highlighted as compared to recovered patients of not-treated subgroup (12.1 vs. 25.4 P<0.001). These results have been pointed out in spite of higher mean age and more serious comorbidities of the treated subgroup. Nevertheless, the incidence of severe acute respiratory distress syndrome is significantly lower in the subgroup of patients with antidepressant treatment (20.6% vs. 43.2% P<0.02) as well as endotracheal intubation employment (0.0% vs. 11.7% P<0.04). The rate of deceased patients of treated-subgroup is not significantly lower than the rate of not-treated subgroup (23.5% vs. 26.4% P=0.13). CONCLUSIONS: During COVID-19 pneumonia, the production of interleukin-6 seems to be modulated in presence of antidepressant therapy. Further proofs and broader surveys are necessary.

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Severely Reduced Left Ventricular Systolic Function in the Low Systolic Function and Transcatheter Aortic Valve Implantation (LOSTAVI) International Registry.

Transcatheter aortic valve replacement (TAVR) is an established therapy for severe, symptomatic aortic valve stenosis even in patients with impaired left ventricular systolic function. However, there is uncertainty on the clinical effectiveness of the currently available TAVR devices in patients with reduced left ventricular ejection fraction (LVEF). The LOSTAVI (Low Systolic function and Transcatheter Aortic Valve Implantation) registry is a retrospective observational study using baseline, procedural, discharge, and long-term follow-up details. A total of 3 groups of interest were distinguished: extremely reduced LVEF (<25%), severely reduced LVEF (25% to 30%), and reduced LVEF (31% to 35%). Unadjusted and adjusted analyses were carried out for in-hospital and follow-up outcomes. A total of 923 patients were included from 12 centers, with 146 patients (16%) with LVEF <25%, 425 (46%) with LVEF 25% to 30%, and 352 (38%) with LVEF 31% to 35%. Several baseline and procedural features were different across groups, including age, risk, functional class, and prevalence of bicuspid disease (all p <0.05). In-hospital mortality was similar in the 3 groups (7 [4.8%], 18 [4.2%], and 7 [2.0%], respectively, p = 0.661), but major adverse events were more common in those with extremely reduced and severely reduced LVEF (19 [13%], 53 [13%], and 25 [7.1%], respectively, p = 0.024). The 12-month follow-up confirmed the significant detrimental impact of reduced LVEF on both death (21 [14%], 49 [12%], and 25 [7.1%], respectively, p = 0.024) and major adverse events (37 [25%], 89 [21%], and 53 [15%], respectively, p = 0.016). The adjusted analysis confirmed the significant prognostic role of LVEF on both outcomes, whereas TAVR device type was not associated with death or major adverse events (all p >0.05). In conclusion, TAVR yields favorable early and 1-year results in patients with reduced LVEF, including those with extremely depressed systolic dysfunction. However, reduced LVEF still represents a major adverse prognostic factor for both short- and mid-term outcomes.

Protective effect of ellagic acid (EA) on micronucleus formation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in mammalian cells, in in vitro assays and in vivo.

The beneficial effects of fruits and vegetables with respect to age-related diseases such as diabetes, atherosclerosis and several types of cancer are widely recognized and confirmed by several epidemiological studies. A possible approach for evaluating the protective potential of promising diet constituents is to evaluate their beneficial effect with respect to a set of biomarkers that are indicative of a potential risk for developing degenerative diseases. Among the numerous biomarkers of the effect of food-related carcinogens and for the assessment of the degree of risk for disease, chromosomal damage detection is very predictive. The aim of this study was to test antigenotoxic effect of ellagic acid (EA) both in in vitro and in vivo studies, in combination with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a methylating agent. EA, a naturally occurring and widely distributed plant phenol, has been intensively studied but with conflicting results, depending on the endpoints considered and the experimental material employed. In vitro and in vivo studies differ in their experimental schedule: in the in vitro study pre- and post-treatments and simultaneous treatments with EA were performed, while in the in vivo study only pre-treatment was carried out. The results of this study clearly demonstrate a protective action of EA with respect to MNNG-induced micronuclei and cell proliferation both in vitro and in vivo. The lack of effect in the post-treatment in in vitro experiments excludes a possible effect of EA on DNA-repair systems. On the other hand, consumption of EA can have a protective action against primary DNA damage induced by oxidative stress.

Transcatheter aortic valve intervention in hospitals without cardiac surgery departments: a future scenario?

Transcatheter Aortic Valve Intervention (TAVI) was introduced in early 2000 to offer treatment to inoperable patients with severe aortic valve stenosis. In a couple of decades, the procedure resulted effective and safe also in patients with intermediate to low risk for surgery; therefore, due to the progressive ageing of the population, the clinical need for TAVI is continuously increasing and is hardly met by the availability of the procedure, the so-called "TAVI capacity". As a result, many patients encounter difficulties in being referred to TAVI centers or face long waiting list times, thus risking severe adverse events (including death) before the procedure is performed. Although contemporary guidelines and consensus documents recommend that TAVI should be only performed in hospitals with active cardiac surgery departments, starting TAVI programs also in interventional cardiac laboratories without on-site cardiac surgery could represent a way to increase TAVI capacity, thus leading to a greater number of patients being treated in less time. On the other side of the coin, such a strategy may jeopardize patient safety in case of periprocedural complications needing bailout surgery and may lead to a suboptimal multidisciplinary Heart Team evaluation. This review aims to assess and discuss available clinical data and implementation of TAVI programs in hospitals without on-site active cardiac surgery departments considering the growing unmet clinical need and technical advancement of TAVI platforms, yet not overlooking the recommendation of international scientific societies.

Study on X-ray-induced apoptosis and chromosomal damage in G2 human lymphocytes in the presence of pifithrin-α, an inhibitor of p53.

The aim of this study is to investigate the role of the cell-cycle phase in cells exposed to radiation and chemicals in relation to the cellular response. The analysis was focused on the G2 cell-cycle phase, exploring the impact of p53 inhibition in human lymphocytes irradiated with X-rays in the presence or absence of pifithrin-α (PFT-α), a p53-specific inhibitor. Lymphocytes, 44h after stimulation to proliferate, were X-irradiated with 0.5Gy both in the presence or the absence of PFT-α and post-treated with a pulse of 5-bromodeoxyuridine (BrdUrd) to distinguish cells in the S- or G2-phase at the moment of irradiation. At early sampling times after X-ray exposure the following parameters were analysed: cellular proliferation, apoptosis, chromosomal aberrations and p53 expression. The results show an enhancement of apoptotic cells in G2 at early sampling times after irradiation and no differences in terms of chromosomal aberration induction both in cells treated with X-rays alone and in cells treated with X-rays plus PFT-α. Expression of p53 was not detectable at all recovery times. The results suggest a p53-independent apoptotic pathway acting at early times after X-ray exposure in G2 lymphocytes. Furthermore, the same yield of X-ray-induced chromatid breaks was observed both in the presence or absence of PFT-α implying that in G2 X-irradiated lymphocytes this inhibitor of the p53 protein does not affect DNA repair.