Intra- and Extra-Hospitalization Monitoring of Vital Signs-Two Sides of the Same Coin: Perspectives from LIMS and Greenline-HT Study Operators

BACKGROUND

In recent years, due to the epidemiological transition, the burden of very complex patients in hospital wards has increased. Telemedicine usage appears to be a potential high-impact factor in helping with patient management, allowing hospital personnel to assess conditions in out-of-hospital scenarios.

METHODS

To investigate the management of chronic patients during both hospitalization for disease and discharge, randomized studies (LIMS and Greenline-HT) are ongoing in the Internal Medicine Unit at ASL Roma 6 Castelli Hospital. The study endpoints are clinical outcomes (from a patient's perspective). In this perspective paper, the main findings of these studies, from the operators' point of view, are reported. Operator opinions were collected from structured and unstructured surveys conducted among the staff involved, and their main themes are reported in a narrative manner.

RESULTS

Telemonitoring appears to be linked to a reduction in side-events and side-effects, which represent some of most commons risk factors for re-hospitalization and for delayed discharge during hospitalization. The main perceived advantages are increased patient safety and the quick response in case of emergency. The main disadvantages are believed to be related to low patient compliance and an infrastructural lack of optimization.

CONCLUSIONS

The evidence of wireless monitoring studies, combined with the analysis of activity data, suggests the need for a model of patient management that envisages an increase in the territory of structures capable of offering patients subacute care (the possibility of antibiotic treatments, blood transfusions, infusion support, and pain therapy) for the timely management of chronic patients in the terminal phase, for which treatment in acute wards must be guaranteed only for a limited time for the management of the acute phase of their diseases.

P119 PERI– MYOCARDITIS A RARE CASE OF ESCHERICHIA COLI INFECTION, A BACTERIUM THAT SHOULD NOT BE UNDERESTIMATED

 

Myopericarditis is defined as inflammation of the heart muscle and pericardium, which can be caused by infectious agents, toxins, or immunological reactions. The most recognized cases are secondary to cardiotropic viral infections. Escherichia coli rarely causes myopericarditis and is secondary to the septic dissemination of bacteria or myocardial toxicity of endotoxins. We describe a case of bacterial sepsis due to Escherichia coli which caused myocardial damage with pericardial effusion. 32 year old woman without cardiovascular risk factors, suffering from congenital immunodeficiency for IG type A, B–cell NH lymphoma undergoing chemotherapy treatment, Hashimoto‘s thyroiditis. The patient arrives for dyspnoea and fever. The ECG showed mild PR depression and an over diffuse ST in all leads with low voltage QRS and increased TNI. PA 120/70 mmHg, HR 74 b / m, FR of 15 acts / m. ETT showed diffuse hypokinesia with FE40% and moderate, circumferential, corpuscular and hyperechoic pericardial effusion without signs of cardiac tamponade. CRP, ESR, Procalcitonin, Leukocytes were elevated, hypothyroidism and low gamma globulin values. The serology of pericardiotropic viruses is negative. Chest x–ray of mild bilateral pleural effusion. Urine culture was performed for pollakiuria, dysuria, fever: positive for Escherichiacoli. After gamma globulin replacement therapy, levothyroxine and targeted antibiotic therapy, the patient presents clinical and laboratory improvement and improvement in FE with persistence of pericardial effusion. Pericardiocentesis is performed with drainage of 800 ml of serous–looking liquid with coarse fibrin shoots. Cytological examination of the liquid shows a blood serum aspect with a carpet of granulocytic inflammatory elements. The patient was discharged after therapy with colchicine, prednisone, levothyroxine sodium, indomethacin, ramipril, omeprazole. The ECG showed an evolved ischemic type pattern.

Conclusion

Very rare cases of Escherichia coli cystitis complicated by myo–pericarditis have been described in the literature. Presumably hypothyroidism and congenital IgA immunodeficiency contributed to favoring and worsening the formation of the effusion. However, further studies are still needed to clarify the mechanisms of myocardial damage, although reversible during this type of bacterial infection.

773 Correlation between high troponin levels and left atrial strain as biomarker of incremented atrial fibrillation rate in patients with acute myocardial infarction

Aims

Heart rhythm disorders, both bradyarrhythmias and tachyarrhythmias, are the most frequently observed complication in the acute phase and after primary angioplasty in patients with acute myocardial infarction (AMI). New onset atrial fibrillation (Afib) represents the most frequent arrhythmia found between 6% and 21% in patients with AMI and its onset increases the thromboembolic and mortality risk of all causes of those patients. Troponin levels measured with modern assays represent today the most specific cardiac biomarker of myocardial injury and its measurement represents the cornerstone for the diagnosis of AMI in accordance with the ESC Guidelines 2018; however, also Afib itself causes an increase in troponin values (troponinopathy). Therefore, the single biohumoral value cannot assume prognostic value in helping the clinician to recognize patients with AMI who are more predisposed to encounter Afib. So, the object of our evaluation was to support the elevated troponin values with echocardiographic biomarkers, such as the evaluation of the left atrial strain (LAS), to perform a more accurate stratification of the arrhythmic risk in patients with AMI.

Methods and results

A prospective multiparametric study was carried out at our Interventional Cardiology Hub Center. 240 patients with ACS-STEMI diagnosed were recruited over one year from March 2020 to March 2021. Patients included were all ≥18 (55 ± 23 y), predominantly male (88% male, 12% female). Exclusion criteria were: permanent atrial fibrillation; valvular heart disease (moderate or severe heart valve stenosis or valve replacement); implantation of a pacemaker or defibrillator; (4) poor image quality. Emergency coronary angiography (CAG) was carried out to execute primary percutaneous intervention (primary PCI with DES) on the culprit vessel. All patients underwent echocardiography by GE Vivid 80 (GE Ultrasound, Horten, Norway) in order to evaluate changes in segmental kinetics, left ventricular ejection fraction (LVEF). The ratio of peak early filling velocity of mitral inflow to early diastolic annulus velocity (E′) of the medial annulus (E/E′) was calculated. Left atrial volumes (LAVi, ml/m2) and diameter were obtained through standard apical 4 and 2 chamber views with a frame-rate range of 40–71 frames/s; then, offline analysis of images was performed using EchoPAC version 201 (GE Vingmed Ultrasound) (VSSLV) software in order to calculate LAS for each one. Patients were subjected to serial sampling to evaluate temporally troponin values and the possible Afib appearance was recognized by telemetry monitoring. Statistical analysis was performed using SPSS version 20 (IBM, Armonk, New York), continuous variables were expressed as mean ± standard deviation (SD). Pearson’s correlation coefficient was used to assess the correlation between strain value, baseline characteristics and troponin levels. All statistical tests are two-sided, and a P-value < 0.05 is considered statistically significant. Two groups were recognized: high troponin levels with pathological LAS and new Afib (N = 47); medium-high troponin levels with normal LAS and no Afib (N = 143). Respectively, LAS were 8.4 ± 4.0% vs. 16 ± 4.5%, P < 0.001, LAVi 44 ± 5 ml/m2 vs. 30 ± 3.2, P = 0.001, and peak of troponin levels (3.45 ± 0.46 ng/ml vs. 2.34 ± 0.22 ng/ml, P = 0.002). Multivariate analysis identified that peak troponin levels alone wasn’t a prognostic index of increased arrhythmic burden, while the correlation between high peak levels and altered LAS were independent predictors of new AFib in AMI.

Conclusions

The evaluation of atrial dysfunction by new echo-derived parameters and its correlation with troponin values allows a more accurate stratification of arrhythmic risk in patients with ACS. The applicability of the obtained data would allow a more careful evaluation of the clinical trend and the prognostic outcome in the subcategory analysed. Therefore, the association between biohumoral and instrumental parameters could become new biomarkers capable of predicting an increase in thromboembolic risk in AMI patients. The creation of an app that takes into account the parameters listed could be a possible future support that can help the clinician calculate the increased risk rate of new Afib in patients with ACS.

ATM-dependent expression of IEX-1 controls nuclear accumulation of Mcl-1 and the DNA damage response

The early-response gene product IEX-1 (also known as IER3) was recently found to interact with the anti-apoptotic Bcl-2 family member, myeloid cell leukemia-1 (Mcl-1). In this study we show that this interaction specifically and timely controls the accumulation of Mcl-1 in the nucleus in response to DNA damage. The IEX-1 protein is rapidly induced by γ-irradiation, genotoxic agents or replication inhibitors, in a way dependent on ataxia telangiectasia mutated (ATM) activity and is necessary for Mcl-1 nuclear translocation. Conversely, IEX-1 protein proteasomal degradation triggers the return of Mcl-1 to the cytosol. IEX-1 and Mcl-1 are integral components of the DNA damage response. Loss of IEX-1 or Mcl-1 leads to genomic instability and increased sensitivity to genotoxic and replicative stresses. The two proteins cooperate to maintain Chk1 activation and G2 checkpoint arrest. Mcl-1 nuclear translocation may foster checkpoint and improve the tumor resistance to DNA damage-based cancer therapies. Deciphering the pathways involved in IEX-1 degradation should lead to the discovery of new therapeutic targets to increase sensitivity of tumor cells to chemotherapy.

Health services use in eating disorders

BACKGROUND

This study examined healthcare services used by adults diagnosed with an eating disorder (ED) in a large health maintenance organization in the Pacific Northwest.

METHOD

Electronic medical records were used to collect information on all out-patient and in-patient visits and medication dispenses, from 2002 to 2004, for adults aged 18-55 years who received an ED diagnosis during 2003. Healthcare services received the year prior to, and following, the receipt of an ED diagnosis were examined. Cases were matched to five comparison health plan members who had a health plan visit close to the date of the matched case's ED diagnosis.

RESULTS

Incidence of EDs (0.32% of the 104,130 females, and 0.02% of the 93,628 males) was consistent with prior research employing treatment-based databases, though less than community-based samples. Most cases (50%) were first identified during a primary-care visit and psychiatric co-morbidity was high. Health services use was significantly elevated in all service sectors among those with an ED when compared with matched controls both in the year preceding and that following the receipt of the incident ED diagnosis. Contrary to expectations, healthcare utilization was found to be similarly high across the spectrum of EDs (anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified).

CONCLUSIONS

The elevation in health service use among women both before and after diagnosis suggests that EDs merit identification and treatment efforts commensurate with other mental health disorders (e.g. depression) which have similar healthcare impact.

High expression of DNA repair pathways is associated with metastasis in melanoma patients

We have identified a gene-profile signature for human primary malignant melanoma associated with metastasis to distant sites and poor prognosis. We analyse the differential gene expression by looking at whole biological pathways rather than individual genes. Among the most significant pathways associated with progression to metastasis, we found the DNA replication (P=10(-14)) and the DNA repair pathways (P=10(-16)). We concentrated our analysis on DNA repair and found that 48 genes of this category, among a list of 234 genes, are associated with metastatic progression. These genes belong essentially to the pathways allowing recovery of stalled replication forks due to spontaneous blockage or induced DNA lesions. Because almost all these differentially expressed repair genes were overexpressed in primary tumors with bad prognosis, we speculate that primary melanoma cells that will metastasize try to replicate in a fast and error-free mode. In contrast to the progression from melanocytes to primary melanoma, genetic stability appears to be necessary for a melanoma cell to give rise to distant metastasis. This overexpression of repair genes explains nicely the extraordinary resistance of metastatic melanoma to chemo- and radio-therapy. Our results may open a new avenue for the discovery of drugs active on human metastatic melanoma.

L'anémie de Fanconi : aspects cellulaires et moléculaires

Fanconi anemia (FA) is a recessive human cancer prone syndrome featuring bone marrow failure, developmental abnormalities and hypersensitivity to DNA crosslinking agents exposure. 11 among 12 FA gene have been isolated. The biochemical functions of the FANC proteins remain poorly understood. Anyhow, to cope with DNA crosslinks a cell needs a functional FANC pathway. Moreover, the FANC proteins appear to be involved in cell protection against oxidative damage and in the control of TNF-alpha activity. In this review, we describe the current understanding of the FANC pathway and we present how it may be integrated in the complex networks of proteins involved in maintaining the cellular homeostasis.

Fanconi anaemia syndrome and apoptosis: state of the art

Fanconi anemia (FA) is a rare recessive, human genetic syndrome characterized by progressive bone marrow failure, developmental abnormalities, predisposition to malignancy, chromosomal instability and DNA damage hypersensitivity. Two (FAA and FAC) of the five genes involved were cloned but their functions remain unknown. At present, the involvement of FA proteins in DNA repair, redox status of the cell and apoptosis are areas of intensive investigation. The aim of this review is to synthesize current results and ideas concerning the involvement of apoptosis in the FA phenotype and conversely, the role of FA proteins in the control of apoptosis.

Futile caspase-8 activation during the apoptotic cell death induced by DNA damaging agents in human B-lymphoblasts

Caspase-8 plays an essential role in apoptosis induced by Fas activation. Moreover, caspase-8 can be processed also in response to exposure to genotoxic agents. To decipher the role of caspase-8 in DNA damaging agent (DDA)-induced apoptosis as well as the pathway(s) leading to its activation in response to genotoxic stress, we investigated caspase-8 processing induced by ionizing radiation (IR) or mitomycin C (MMC) treatment in human B-lymphoblasts. Altogether, our observations establish that caspase-8 is actively processed in both receptor-mediated and DDA-induced cell death. However, while Fas-dependent apoptosis absolutely required caspase-8 activity, it is not necessary for completion of the apoptotic program induced by IR and MMC. Experiments performed to understand the molecular pathway(s) of the caspase-8 activation after DDA demonstrated that for both IR and MMC, the Fas/Fas-L interaction is dispensable. Data obtained from caspase inhibitors and from lymphoblasts carrying mutations in ATM and FANCC proteins, involved in DDA response, clearly showed that distinct mechanisms are responsible for caspase-8 activation by IR and MMC in B-lymphoblasts. IR-dependent processing of caspase-8 involves ATM, mitochondrial collapse, FANCC, and caspase-3 activation. Caspase-8 activation by MMC evokes the mitochondrial pathways involving FANCC but not ATM. Collectively, our data indicate that caspase-8 activation is essentially a bystander effect and not a major determinant of the behavior of DDA-exposed cells.

ATM protein is required for radiation-induced apoptosis and acts before mitochondrial collapse

PURPOSE

To define the role of the ataxia telangiectasia (A-T) mutated gene (ATM) in activation and progress of apoptosis.

MATERIAL AND METHODS

Three normal and three A-T EBV-transformed cell lines were studied. Following irradiation (IR), Fas activation or ceramide exposure, viability and apoptosis were measured by trypan blue dye exclusion assay and as sub-G1 cell fraction by flow cytometric analysis of propidium iodide stained cultures, respectively. Activation of caspase-3 was evaluated by immunoblot and by an in vitro activity assay on cytosolic cell extracts. To assess changes in mitochondrial potential and reactive oxygen species, cells were stained by 3,3'-dihexyloxacarbocynine iodide or hydroethidine, respectively, and scored by flow cytometry.

RESULTS

The observations establish that A-T cells are equipped with a proficient apoptotic machinery, as demonstrated by their ability to undergo mitochondrial collapse and caspase-3 activation after Fas activation or ceramide treatment. Both treatments have a similar cytotoxic effect on normal and A-T cells. In contrast, in spite of the stronger cytotoxicity induced by IR exposure, irradiated A-T cells are unable to undergo mitochondrial collapse and caspase-3 activation.

CONCLUSIONS

The data indicate that ATM is necessary in the initiation of molecular pathway(s) leading to IR-induced apoptosis, and suggest that increased radiosensitivity of A-T cells is more likely a direct consequence of necrotic cell death.

Loss of the Fanconi anemia group C protein activity results in an inability to activate caspase-3 after ionizing radiation

Fanconi anemia (FA) is a human genetic disease featuring cancer predisposition, genetic instability and DNA damage hypersensitivity. Although abnormalities in DNA repair and cell cycle checkpoint have been proposed as the underlying defect in this syndrome, these hypotheses did not provide full explanations of the complex phenotype. Although not exclusive of such possibilities, alterations in the control of apoptosis might account for the pleiotropic phenotype of this syndrome. We and others have previously reported a deregulation of the apoptotic response to mitomycin C, suggesting that the products of the Fanconi anemia group C protein (FANCC) contribute to the regulation of apoptosis. To explore the functional importance of the apoptotic alterations in FA we analyzed biochemical steps of the execution phase of apoptosis stimulated by another DNA damaging agent, the gamma-ray using FA cell lines derived from complementation group C (FA-C) independent patients. It is shown that the poly(ADP-ribose) polymerase, a target of caspase-3, is not cleaved in FA-C after ionizing radiation (IR). Moreover, caspase-3 is not processed in its active form and, its activity is not increased by IR in FA-C cells compared to normal cells. Altogether, these results demonstrate that loss of the FANCC activity results in a deficiency of the IR-induced apoptosis which is due to an inability to activate caspase-3. Our work suggests that apoptosis signaling induced by mitomycin C and IR is subject to common regulation involving the FANCC protein.

Fanconi anemia C protein acts at a switch between apoptosis and necrosis in mitomycin C-induced cell death

Deregulation of apoptosis seems to be a hallmark of the Fanconi anemia (FA) syndrome. In order to further define the role of the FA protein from complementation group C (FAC) in apoptosis, we characterized parameters modified during the mitomycin-C (MMC)-induced apoptotic program. It is shown that despite a higher level of cell death for FA compared to normal lymphoblasts after MMC treatment, FA cells do not display a marked DNA fragmentation. Furthermore, while playing a central role in MMC apoptosis of normal lymphoblasts, the activity of caspase-3-like proteases is altered in FA cells. Interestingly, the disruption of the mitochondrial transmembrane potential (Deltapsi), an early event that can lead to apoptotic or to necrotic death, is accomplished similarly in FA and in normal cells. Finally, it is shown that the overexpressed FAC protein inhibited the apoptotic steps, with the exception of the decrease of the Deltapsi. Altogether, our results indicate that the FAC protein acts at a step preceding the activation of the caspases and after the modification of the Deltapsi, a decision point at which cells can be pushed toward either apoptosis or necrosis and which, consequently, regulates the balance between the two modes of cell death.

Role of a mutant p53 protein in apoptosis: characterization of a function independent of transcriptional trans-activation

Wild-type (wt) tumor suppressor p53 has been implicated in cellular radiosensitivity, mediated by its role in apoptosis and growth arrest. Intriguingly, it was observed that the temperature sensitive (ts) mutant p53val135 protein functions as a positive modulator of cellular radiosensitivity, as evident from acceleration of irradiation-induced apoptosis of M1p53ts (p53val135) cells at the non-permissive temperature; this effect was correlated with acceleration of exit from the G2 checkpoint of the cell cycle. In this work it is shown that the ability of mutant p53val135 to accelerate irradiation-induced apoptosis, at the non-permissive temperature, was devoid of transcriptional trans-activation of p53 target genes. In contrast, the apoptotic function of wt p53val135 was observed to include components which are both dependent and independent of transcriptional trans-activation. Taken together, these observations suggest that mutant p53val135 protein retains the apoptotic component of wt p53 that is devoid of transcriptional trans-activation, and that, although this activity is insufficient to induce apoptosis on its own, it can cooperate to accelerate DNA damage-induced cell death. The results of this work contribute to a better understanding of the complexity of the apoptotic response elicited by wt p53, and highlight the potential role of mutant p53 proteins, as well as trans-activation independent apoptosis, in tumor suppression by irradiation therapy.

Impaired DNA repair as assessed by the "comet" assay in patients with thyroid tumors after a history of radiation therapy: a preliminary study

PURPOSE

Patients with a history of head and neck irradiation in childhood are at risk to develop thyroid tumors. The aim of this study was to determine if an impairement of DNA strand breaks repair could account for this observation.

METHODS AND MATERIALS

Circulating unstimulated lymphocytes of a group of 13 patients who developed thyroid tumors after radiotherapy were submitted to the alkaline single-cell gel electrophoresis assay (SCGE or "comet" assay) after in vitro exposure to 2 and 5 Gy of gamma-rays. A control group of 8 healthy donors and 2 cases with a history of neck irradiation who did not develop a thyroid tumor were also analysed. The immediate response was compared to that observed after 15, 30, and 60 min of postexposure incubation periods.

RESULTS

Induction of DNA strand breaks is a dose-dependent process. The SCGE assay parameters did not differ significantly between patients and controls immediately (t=0) after irradiation at the two doses used. As compared to healthy donors, a slower kinetics of repair was found in the patients. The proportion of residual damage at 60 min postirradiation was significantly (p < 0.01) higher in patients than in controls, at both doses analysed. Flow cytometric analysis of apoptosis and p53 protein status studied before and after irradiation showed no apparent relationship with the repair capacity.

CONCLUSION

This preliminary study suggests that a subgroup of patients who develop thyroid tumors after a history of irradiation are partially defective in the late restitution of in vitro radiation-induced DNA strand breaks. This deficiency could be a predisposing factor to radiation-associated thyroid tumorigenesis. Detection of susceptible individuals using the simple and rapid comet assay, especially children receiving radiotherapeutic treatment, may allow a preventive surveillance for radiation-associated epithelial thyroid tumor development.

Effects of neurohormonal antagonism on symptoms and quality-of-life in heart failure

Increased mortality and reduced functional capacity are the two main characteristics of chronic heart failure. Activation of the renin-angiotensin and sympathetic systems has a primary role in the progressive worsening of heart failure and increased mortality of patients. In addition, both systems may be important in the pathogenesis of exercise intolerance, although there is only a weak relationship between neurohormonal activation and exercise capacity. While neurohormonal antagonists, such as angiotensin-converting enzyme (ACE) inhibitors and beta-blockers, consistently improve the prognosis of patients with heart failure, their effects on exercise tolerance have often been less significant. This problem has been emphasized by the introduction of beta-blockers for the therapy of heart failure. Beta blockade results in a significant improvement in left ventricular function during rest and exercise. However, the reduction in chronotropic response to exercise as well as the metabolic changes caused by these agents in skeletal muscle may result in an apparent lack of change in maximal functional capacity. This effect is particularly important with the new third generation non-selective beta-blockers. The pronounced anti-adrenergic activity of these compounds accounts for their greater negative chronotropic effect and relates to the lack of improvement in peak oxygen consumption (VO2). Submaximal exercise testing can be used to assess changes induced by these agents. However, even the six-minute walk test may act as an almost maximal test in patients with advanced heart failure: moreover, the measurement of submaximal exercise duration may be sensitive enough to detect changes in single-centre trials, but not in multicentre trials. To date, direct assessment of symptoms by both patient and physician is still the most sensitive tool to monitor changes in functional status with non-selective beta-blockers. Thus, an accurate method of measuring patients' symptoms, in addition to the clinical examination, is still necessary when neurohormonal antagonists are used in patients with chronic heart failure.

[The effects of mid- and long-term administration (3-4 years) of carvedilol in patients with idiopathic dilated cardiomyopathy]

Carvedilol has been shown to determine a significant improvement in left ventricular function, symptoms, clinical course and prognosis of patients with chronic heart failure. However, these results were obtained in medium-term studies of < 1 year duration. We report the results obtained with long-term (3-4 years) carvedilol administration to 40 patients with idiopathic dilated cardiomyopathy who were initially recruited in a 4-month double-blind placebo-controlled trial. In the initial 4-month double-blind trial, 20 patients were randomized to placebo and 20 to carvedilol treatment. All patients, except one who was not on ACE-inhibitors, were on digoxin, furosemide and ACE-inhibitors. Carvedilol or placebo doses were progressively titrated, at weekly intervals, up to the maximal doses of 25 mg bid. After the initial 4-month double-blind phase, all patients were followed long term. Mean follow-up duration was 52 +/- 12 months (range 48-61). Among the 20 patients initially randomized to carvedilol administration, 4 died (3 for cardiac and 1 for extracardiac causes) and 2 underwent heart transplant. Among the 20 patients initially randomized to placebo, 5 died for cardiac causes, 3 underwent heart transplant and 4 were started on carvedilol because of progressive heart failure during the initial 4 months of the study. The remaining 8 patients, who were kept on digoxin, furosemide and ACE-inhibitors, were used as control group. Each patient underwent an assessment of clinical conditions (NYHA functional classification and Minnesota Living with Heart Failure questionnaire), equilibrium radionuclide ventriculography, and maximal cardiopulmonary bicycle exercise testing. Exams were performed before treatment, after 4 and 12 months, and at the end of the follow-up period. No significant difference between the carvedilol and control group was present at baseline. Compared with baseline, patients in the control group presented a significant increase in left ventricular end-diastolic volume after long-term follow-up (from 126 +/- 62 to 138 +/- 43 and 158 +/- 52 ml/m2 after 12 and 48 months, respectively). No significant difference, compared to baseline values, was noted. Patients on carvedilol presented a persistent improvement in left ventricular function. This was shown by the progressive increment in left ventricular ejection fraction from 22 +/- 6 to 34 +/- 11, 37 +/- 11 and 37 +/- 13%, after 4, 12 and 48 months, respectively (p < 0.001) with a concomitant reduction in left ventricular end-diastolic volume from 147 +/- 54 to 101 +/- 44 ml/m2 at the end of the follow-up (p < 0.05). NYHA functional class remained significantly improved, in comparison with baseline (2.6 +/- 0.5 to 1.9 +/- 0.3, 1.9 +/- 0.8 and 2.0 +/- 1.0 after 4, 12 and 48 months, respectively; p < 0.01). Maximal functional capacity, assessed as peak VO2 was not significantly changed after 4 months (from 15.2 +/- 3.6 to 16.4 +/- 4.0 ml/kg/min) and showed a tendency towards a further improvement after 12 months and at the end of the follow-up (17.3 +/- 5.6 and 17.2 +/- 5.3 ml/kg/min, respectively). These results show that the favorable effects of carvedilol administration on left ventricular function and clinical symptoms are maintained also after long-term treatment.

Deregulated apoptosis is a hallmark of the Fanconi anemia syndrome

Fanconi anemia (FA) is a genetic human disorder associated with bone marrow failure and predisposition to cancer. FA cells show poor growth capacity and spontaneous chromosomal anomalies as well as cellular and chromosomal hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC). Because it is likely that disruption of the apoptotic control would lead to such a phenotype, we investigated the implication of apoptosis in the FA syndrome. It is shown that, although demonstrating a high frequency of spontaneous apoptosis, FA cells from four genetic complementation groups are deficient in gamma-ray-induced apoptosis and their MMC hypersensitivity is not due to apoptosis. Fas is a cell surface receptor belonging to the tumor necrosis factor receptor family and is involved in apoptosis. We show that, independently of DNA damage, the alteration in the control of apoptosis in FA concerns also the pathway initiated by Fas activation. Finally, ectopic expression of the wild-type FAC gene corrects the MMC hypersensitivity and anomalies in apoptosis and cell cycle response in FA cells. Altogether, these findings strongly implicate the FA genes as playing a major role in the control of apoptosis. Thus, further studies with FA syndrome will be instrumental toward molecularly dissecting the apoptotic pathways.

Deregulated apoptosis in ataxia telangiectasia: association with clinical stigmata and radiosensitivity

Ataxia telangiectasia (AT) is a recessive genetic disease featuring neurodegeneration, immunodeficiency, chromosomal instability, radiation hypersensitivity, and increased predisposition to cancer. Reduced or delayed induction of the tumor suppressor protein p53 after gamma -irradiation was reported. These characteristics may be compatible with an inability to correctly regulate apoptosis. We show here that AT lymphocytes and EBV-transformed lymphoblasts demonstrate a significantly higher level of spontaneous apoptosis, whereas ionizing radiation-induced apoptosis is reduced compared to normal cells. However, neither AT nor normal primary fibroblasts undergo apoptosis after irradiation. Consequently, we conclude that the radiosensitivity of the AT cells is not related to an increased apoptotic response. Finally, we show that SV40-transformed AT fibroblasts undergo gamma- ray-induced apoptosis, while SV40-transformed normal cells do not. This result raises the question of the physiological relevance of the latter cellular model with respect to the AT phenotype.

p53 involvement in control of G2 exit of the cell cycle: role in DNA damage-induced apoptosis

DNA damage in proliferating mammalian cells induces a complex cellular response comprising perturbation of the cell cycle and programmed cell death. The relationship between p53-dependent and p53-independent apoptotic cell death, as well as the cell cycle checkpoints induced by DNA damaging agents were explored in hematopoietic cells, using M1 myeloblastic leukemia cells, which are null for p53 expression, genetically engineered M1 variants, expressing p53ts and bcl-2 transgenes, as well as myeloblast enriched bone-marrow cells obtained from wild type p53 (wt p53) and p53-deficient mice. It is shown that gamma-irradiation of M1p53ts cells activated a function of the temperature sensitive mutant transgene p53 (p53ts), promoting increased apoptosis relative to parental, null p53 M1 cells. It is also shown that the kinetics of apoptotic cell death induced by gamma-irradiation correlated with the rapidity of exit from gamma-ray-induced G2 arrest for all the different hematopoietic cell types indicated above. Finally, data has been obtained to demonstrate that, in addition to a role in apoptosis and G1 arrest, wild-type p53 positively modulated the exit from the gamma-ray-induced G2 checkpoint. Taken together, these findings indicate that this new function for p53 is a component of the physiological pathway by which p53 exerts its role in apoptosis.

p53-dependent pathway of radio-induced apoptosis is altered in Fanconi anemia

Fanconi anemia belongs to a group of human genetic diseases characterized by chromosomal instability, sensitivity to genotoxic agents associated to impaired processing of DNA lesions, cell cycle anomalies and cancer predisposition. We recently added to this list of distinctive features reduced production of interleukin 6 and overproduction of tumor necrosis factor alpha. Since growth factor deprivation, TNF alpha treatment or DNA damage can trigger apoptosis, we monitored the apoptotic response of FA cell lines. We show here that, although the spontaneous rate of apoptosis is slightly more elevated in FA than in normal cell cultures, the apoptosis induced by gamma-irradiation is drastically reduced in FA. Since the induction of apoptosis by radiation is a p53-dependent mechanism, the induction of this protein in FA cells was also examined. We found that the p53 protein is not radio-induced in FA cells belonging to the two genetic complementation groups examined (C and D), in contrast to normal cells. Moreover, the same impairment in p53 induction is observed after exposure to mitomycin C, a chemical agent for which FA cells demonstrate a specific cellular and chromosomal hypersensitivity, as well as after u.v.-B irradiation, an agent known to cause oxidative stress. These observations are in line with recent reports showing that at least certain cell lines from other chromosome breakage syndromes, such as ataxia telangiectasia and Bloom syndrome, may be also defective for radiation-induced increase of p53 protein. As the p53 tumor suppressor gene encodes a transcriptional activator whose targets include genes that regulate genomic stability, cellular response to DNA damage and cell cycle progression, we suggest that altered expression of p53 may be relevant to the FA phenotype.

Comparison of the effects of DNA topoisomerase inhibitors on lymphoblasts from normal and Fanconi anemia donors

DNA topoisomerases modify supercoiled DNA through concerted breaking and rejoining of the DNA strands and consequently play a key role in DNA biosynthesis and processing. It has been suggested that topoisomerases may facilitate access to damaged sites of excision repair enzymes due to their property to relax supercoiled DNA. We show here that treatment with nalidixic acid and novobiocin, which affects topoisomerase II activity among other targets, impairs the incision of 8-methoxypsoralen photoinduced DNA interstrand cross-links in normal human fibroblasts. Since cells derived from Fanconi anemia (FA) demonstrate hypersensitivity to DNA cross-linking agents associated with a reduced repair efficiency of cross-links, we compared the effects of different topoisomerase I and II inhibitors on FA and normal lymphoblasts. No differences were found in growth inhibition or induction of chromosome aberrations between FA and normal cells. The specificity of inhibitors is questionable and even if topoisomerases are indeed inhibited alternative pathways may be involved. However, our observations provisionally suggested that topoisomerases activities are normal in FA cells.

[Changes in the radiation-induced apoptotic response in homozygotes and heterozygotes for the ataxia-telangiectasia gene]

Ataxia-telangiectasia is a progressive recessive disease featuring neurodegeneration, immunodeficiency, chromosomal instability, radiation hypersensitivity and increased predisposition to cancer. Impaired induction of the tumor suppressor protein p53 after gamma-irradiation was recently reported. All together these characteristics may be compatible with an inability to correctly regulate the apoptotic pathway of cell death in this syndrome. We show here that lymphocyte cultures from AT patients are characterized by a 3 times more elevated spontaneous level of apoptotic cells compared to normal ones. In spite of this, 24 h after exposure to gamma-irradiation (5 to 10 Gy), AT lymphocytes show a dramatically reduced capacity to undergo apoptosis compared to normal cells. We obtained similar results on EBV-transformed lymphoblasts. Interestingly, lymphoblasts from obligate heterozygous for the AT mutation(s) show the same features as AT lymphoblasts, i.e. an elevated frequency of spontaneous and a reduced level of radio-induced apoptotic figures in comparison to normal cultured cells. In conclusion, we show here, for the first time, that mutation(s) in AT gene(s) results in an impaired ability to correctly regulate the apoptotic pathway of cell death.

Abnormal lymphokine production: a novel feature of the genetic disease Fanconi anemia. II. In vitro and in vivo spontaneous overproduction of tumor necrosis factor alpha

We have previously shown an unbalanced cytokine production in Fanconi anemia (FA) cells, ie, an underproduction of interleukin 6 (IL-6) during growth. Among a number of cytokines analyzed, the only other anomalies detected concern tumor necrosis factor alpha (TNF alpha). In comparison to normal cells, this cytokine is overproduced by FA lymphoblasts from the four genetic complementation groups. Indeed, up to an eight-fold increase in TNF alpha is observed in the growth medium of FA cells. Moreover, addition of anti-TNF alpha antibodies partially corrects the FA hypersensitivity to treatment by mitomycin C (MMC). Treatment of FA cells with IL-6, which partially restored an almost normal sensitivity to MMC of FA cells also reduces the TNF alpha overproduction in FA lymphoblasts. No anomalies at the molecular level (Southern and Northern blot analyses) are detected for the TNF alpha gene and its mRNA. We have investigated the in vivo situation by assaying TNF alpha levels in the serum from FA homozygotes and obligate heterozygotes. In contrast to normal healthy donors or to aplastic anemia patients in whom serum TNF alpha is present only in trace amounts, all 36 FA patients and 21 FA parents monitored show a significantly (P < .001) higher level of serum TNF alpha activity. Consequently, abnormal TNF alpha production seems to be associated with the FA genetic background.

Abnormal lymphokine production: a novel feature of the genetic disease Fanconi anemia. I. Involvement of interleukin-6

The correction of chromosomal hypersensitivity to mitomycin C (MMC) in Fanconi anemia (FA) human lymphoblasts is observed by growth in a medium conditioned by normal human cells. Under the same conditions, the cytotoxic effect of MMC on FA cells is restored to an almost normal level. The addition of interleukin-6 (IL-6) to an unconditioned culture medium increased the resistance of FA cells to MMC cytotoxicity. This correcting effect is partially abolished by addition of an anti-IL-6 antibody to the conditioned medium. Both lymphoblasts and fibroblasts derived from FA patients demonstrate a reduction in IL-6 production. Moreover, this lymphokine is not induced by tumor necrosis factors alpha and beta (TNF alpha and TNF beta) in FA cells, as is the case in normal cells. It is suggested that the observed deficiency in IL-6 production may account for one of the major characteristics of FA disease, i.e., the defect in differentiation of the hematopoietic system.

Partial complementation of the Fanconi anemia defect upon transfection by heterologous DNA. Phenotypic dissociation of chromosomal and cellular hypersensitivity to DNA cross-linking agents

Transfectants obtained by mouse DNA-mediated gene transfer in Fanconi anemia (FA) primary fibroblasts from the genetic complementation groups A and B were examined for the frequencies of chromosomal aberrations and cytotoxicity following treatments by cross-linking agents. Cells from group A (FA 150), which is the most sensitive to such agents, are partially corrected for both the chromosomal and cellular hypersensitivity to 8-methoxypsoralen photoaddition. In contrast, after treatment with mitomycin C (MMC), only the chromosomal sensitivity is re-established to a near normal level. The opposite is true for FA group B cells (FA 145), i.e. cell survival to MMC is partially corrected, whereas the frequency of MMC-induced chromosomal aberration remains close to that of the untransfected cells. The partial phenotypic correction of the two end points examined is interpreted as indicating either a gene dosage effect or the necessity of introducing more than one gene type in order to achieve complete recovery of a normal phenotype. The phenotypic dissociation between the clastogenic and cellular hypersensitivity to cross-linking agents may offer the opportunity of isolating separately the responsible gene(s) by conventional rescue techniques.

Persistence of drug-induced chromosome aberrations in peripheral blood lymphocytes of the rat

We have studied the persistence of pre-clastogenic lesions, detected as induced chromosomal aberrations, in rat peripheral lymphocytes at various time intervals after acute treatment with 3 different antineoplastic drugs: cyclophosphamide (CPA), 5-fluorouracil (5-FU) and adriamycin (AM). Single i.p. doses were administered to groups of rats and heart blood samples from each group were taken after 3, 12, 24 or 48 h or weekly up to 20 weeks later. The cytogenetic analysis was performed on lymphocytes cultured for 33 h after sampling. The results for CPA exposure (10 mg/kg) show that the yield of chromosome aberrations is maximal 3 h after the treatment (20 times the control level). For up to 8 weeks the values remain about 6 times the baseline; afterwards a decrease is observed and the control level is reached after 20 weeks. For 5-FU (50 mg/kg) a remarkable increase (13-fold) in chromosomal damage is observed at the first sampling time. Within 48 h the effect is drastically reduced but persistent (3 times the control level), and the level returns to spontaneous values 1 week later. AM treatment (2 mg/kg) induced an increase of about 8 times the control level at 3 h post exposure. The clastogenic effects remained at a detectable level for 1 week (about 6 times the control level at all sampling times); 2 weeks after the treatment the control level was found. A parallel analysis was performed on bone marrow cells. In this tissue the clastogenic effects of the treatments were maximal, as in lymphocytes, at the first sampling time (20-25 times the control level) and were no longer detectable within 72 h after exposure, irrespective of the administered drug.

Cocultivation of Fanconi anemia cells and of mouse lymphoma mutants leads to interspecies complementation of chromosomal hypersensitivity to DNA cross-linking agents

We have studied the effects of cocultivation on the frequency of mitomycin C (MMC)-induced chromosomal aberrations. This was carried out by cocultivating Fanconi anemia (FA) cells from the genetic complementation groups A and B with both normal mouse lymphoma L5178Y cells and the derived "FA-like" mutant cells, MCN-151 and MCE-50, assigned to complementation groups I and II, respectively. The results show a partial complementation of the defect (i.e. a reduction in the frequency of chromosomal aberration) in FA group A cells cocultured with normal or group II mouse cells, and a partial correction of mouse group I cells cocultived with normal or FA group B human cells. No reciprocal effects were observed between FA group A cells and mouse group I mutant cells; the frequencies of MMC-induced chromosomal aberrations in these cells remained unchanged by cocultivation. Moreover, no complementation was observed for both FA group B cells and mouse group II cells, after cocultivation with normal cells of either mouse or human origin. This implies that a diffusible factor released by normal human and mouse cells, and by FA group B and mouse group II mutant cells, can correct at least in part the chromosomal defect of FA group A and mouse group I mutant cells. With normal human or mouse cells, the frequency of chromosomal breakage after cocultivation remains the same as that observed in non-cocultived cells. This suggests that no detectable clastogenic factor is released by human FA or "FA-like" mouse cells.

Chromosomal hypersensitivity in mutant MCN-151 mouse cells exposed to mitomycin C

After exposure to mitomycin C, the mouse lymphoma cell mutant MCN-151, previously shown to be sensitive to the toxic effect of the drug, demonstrates higher frequencies of chromatid-type aberrations and of aberrant cells in comparison to L5178Y cells. At any given dose of mitomycin C, the frequencies of chromosomal aberrations increased with time reaching a plateau in both cell strains, with the mutant in all cases being more sensitive than normal cells.

Clastogenic effects induced in mice and rats by 1,4-bis[2-(3,5-dichloropyridyloxy)]-benzene, a phenobarbital-like enzyme inducer and liver tumour promoter

The clastogenic activity of 1,4-bis[2-(3,5-dichloropyridyloxy)]-benzene (TCPOBOP), a phenobarbital-like enzyme inducer and liver tumour promoter, was studied in mammalian cells exposed in vivo and in vitro. The effects of an oral treatment with 3 mg/kg body weight of TCPOBOP were scored in the bone marrow cells and in the liver cells of B6C3F1 hybrid mice. A relevant increase in the frequency of chromosomal aberrations was observed in both cell types. A co-administration of TCPOBOP and carbon tetrachloride (the latter given to stimulate liver cell divisions) produced similar effects to those induced by TCPOBOP alone. Several i.p. doses (1, 3, 10, 30 or 100 mg/kg body weight) were administered to Swiss-albino mice and to Sprague-Dawley rats. In bone marrow cells, a remarkable concordance between the two species was observed: at any dose higher than 3 mg/kg body weight the increase in frequency of chromosomal aberrations was more than three times the control level, with a slight decrease at the highest dose. A dose of 300 mg/kg body weight was lethal. Doses of 3 or 30 mg/kg body weight were also administered i.p. to partially hepatectomized rats and the effects on metaphase chromosomes were detected in the liver cells. Besides an increase in structural chromosomal aberration frequency, TCPOBOP induced high percentages of hypodiploid and hyperdiploid-hypotetraploid liver cells. Since no changes in euploidy were observed in the bone marrow cells, this effect seems to be tissue specific. The clastogenic activity of TCPOBOP was also confirmed in vitro by a rat lymphocyte assay without addition of any exogenous metabolic activation.

Chromosome aberrations in rat liver cells and bone marrow cells following treatment in vivo with mitomycin C

The clastogenic potential of mitomycin C (MMC) was studied in rat liver cells and bone marrow cells. Male Sprague-Dawley rats were partially hepatectomized and treated with a single i.p. dose of MMC (3.5 mg/kg body weight) 7 or 24 h after the operation. Non-hepatectomized rats were also treated with the same dose of MMC 7 or 24 h after the mutagenic treatment; liver and bone marrow cells were isolated from hepatectomized rats (31 h after the operation) and bone marrow cells only from non-hepatectomized animals. The results show that, if MMC was administered 7 h before the isolation of cells, the induction was more efficient in liver cells than in bone marrow cells. At this sampling time, there was no consistent difference between the frequencies observed in bone marrow cells from hepatectomized and non-hepatectomized rats. An increase was observed in both tissues 24 h after the mutagenic treatment. At this sampling time, the effect was significantly higher in the bone marrow cells from non-hepatectomized animals than in the liver cells and bone marrow cells from hepatectomized animals. No significant difference between the two cell types from hepatectomized rats was observed. Different factors related to the cytostatic properties of MMC and/or to cell kinetics in the two cell types, probably affected by the surgical operation, may account for the differences in the yield of chromosomal damage.