Targeting DNA2 overcomes metabolic reprogramming in multiple myeloma

DNA damage resistance is a major barrier to effective DNA-damaging therapy in multiple myeloma (MM). To discover mechanisms through which MM cells overcome DNA damage, we investigate how MM cells become resistant to antisense oligonucleotide (ASO) therapy targeting Interleukin enhancer binding factor 2 (ILF2), a DNA damage regulator that is overexpressed in 70% of MM patients whose disease has progressed after standard therapies have failed. Here, we show that MM cells undergo adaptive metabolic rewiring to restore energy balance and promote survival in response to DNA damage activation. Using a CRISPR/Cas9 screening strategy, we identify the mitochondrial DNA repair protein DNA2, whose loss of function suppresses MM cells' ability to overcome ILF2 ASO-induced DNA damage, as being essential to counteracting oxidative DNA damage. Our study reveals a mechanism of vulnerability of MM cells that have an increased demand for mitochondrial metabolism upon DNA damage activation.

Targeting DNA2 Overcomes Metabolic Reprogramming in Multiple Myeloma

DNA damage resistance is a major barrier to effective DNA-damaging therapy in multiple myeloma (MM). To discover novel mechanisms through which MM cells overcome DNA damage, we investigated how MM cells become resistant to antisense oligonucleotide (ASO) therapy targeting ILF2, a DNA damage regulator that is overexpressed in 70% of MM patients whose disease has progressed after standard therapies have failed. Here, we show that MM cells undergo an adaptive metabolic rewiring and rely on oxidative phosphorylation to restore energy balance and promote survival in response to DNA damage activation. Using a CRISPR/Cas9 screening strategy, we identified the mitochondrial DNA repair protein DNA2, whose loss of function suppresses MM cells' ability to overcome ILF2 ASO-induced DNA damage, as being essential to counteracting oxidative DNA damage and maintaining mitochondrial respiration. Our study revealed a novel vulnerability of MM cells that have an increased demand for mitochondrial metabolism upon DNA damage activation.

STATEMENT OF SIGNIFICANCE

Metabolic reprogramming is a mechanism through which cancer cells maintain survival and become resistant to DNA-damaging therapy. Here, we show that targeting DNA2 is synthetically lethal in myeloma cells that undergo metabolic adaptation and rely on oxidative phosphorylation to maintain survival after DNA damage activation.

Identification of an Epi-metabolic dependency on EHMT2/G9a in T-cell acute lymphoblastic leukemia

Genomic studies have identified recurrent somatic alterations in genes involved in DNA methylation and post-translational histone modifications in acute lymphoblastic leukemia (ALL), suggesting new opportunities for therapeutic interventions. In this study, we identified G9a/EHMT2 as a potential target in T-ALL through the intersection of epigenome-centered shRNA and chemical screens. We subsequently validated G9a with low-throughput CRISPR-Cas9-based studies targeting the catalytic G9a SET-domain and the testing of G9a chemical inhibitors in vitro, 3D, and in vivo T-ALL models. Mechanistically we determined that G9a repression promotes lysosomal biogenesis and autophagic degradation associated with the suppression of sestrin2 (SESN2) and inhibition of glycogen synthase kinase-3 (GSK-3), suggesting that in T-ALL glycolytic dependent pathways are at least in part under epigenetic control. Thus, targeting G9a represents a strategy to exhaust the metabolic requirement of T-ALL cells.

Hematopoiesis under telomere attrition at the single-cell resolution

The molecular mechanisms that drive hematopoietic stem cell functional decline under conditions of telomere shortening are not completely understood. In light of recent advances in single-cell technologies, we sought to redefine the transcriptional and epigenetic landscape of mouse and human hematopoietic stem cells under telomere attrition, as induced by pathogenic germline variants in telomerase complex genes. Here, we show that telomere attrition maintains hematopoietic stem cells under persistent metabolic activation and differentiation towards the megakaryocytic lineage through the cell-intrinsic upregulation of the innate immune signaling response, which directly compromises hematopoietic stem cells' self-renewal capabilities and eventually leads to their exhaustion. Mechanistically, we demonstrate that targeting members of the Ifi20x/IFI16 family of cytosolic DNA sensors using the oligodeoxynucleotide A151, which comprises four repeats of the TTAGGG motif of the telomeric DNA, overcomes interferon signaling activation in telomere-dysfunctional hematopoietic stem cells and these cells' skewed differentiation towards the megakaryocytic lineage. This study challenges the historical hypothesis that telomere attrition limits the proliferative potential of hematopoietic stem cells by inducing apoptosis, autophagy, or senescence, and suggests that targeting IFI16 signaling axis might prevent hematopoietic stem cell functional decline in conditions affecting telomere maintenance.

Retrogasserian radiofrequency thermocoagulation: A repeatable treatment in trigeminal neuralgia unresponsive to drug therapy

Background:

Trigeminal neuralgia present an incidence rates ranging between 5.9 and 12.6 per 100.000 persons; although not frequent, it is a pathology often characterized by intense pain, an extremely significant reduction in quality of life and medical therapy is not always effective or tolerated. In these cases, the patient can undergo interventional treatments including radiofrequency thermocoagulation. There are still doubts regarding the effectiveness over time, the injury parameters and the repeatability of the procedure.

Materials and Methods:

We analyze patients with trigeminal pain undergo retrogasserian radiofrequency in a single center over a period of 8 years. The procedure was performed with the following parameters: Lesion time 60 sec, lesion temperature 70°C for first thermolesion 72°C for subsequent thermolesions. Duration of benefit, number of repetitions of the maneuver, and incidence of adverse events were assessed.

Results:

Totally, 122 patients with essential trigeminal neuralgia and 20 patients with trigeminal neuralgia secondary to multiple sclerosis were analyzed; almost all patients (96.5%) showed a significant reduction in pain after one or more procedures over time; 96.5 of the patients showed excellent pain relief after 1 (40%) or more procedures (60%). The average time between one procedure and the next was 26 months.

Conclusion:

The use of time and temperature parameters chosen shows excellent efficacy, in line with the literature, with very low incidence of adverse events. The pain-free time between one procedure and the next does not seem to be a significant prognostic criterion which may or may not indicate the repetition of the procedure.

Targeting oncogenic Notch signaling with SERCA inhibitors

P-type ATPase inhibitors are among the most successful and widely prescribed therapeutics in modern pharmacology. Clinical transition has been safely achieved for H+/K+ ATPase inhibitors such as omeprazole and Na+/K+-ATPase inhibitors like digoxin. However, this is more challenging for Ca2+-ATPase modulators due to the physiological role of Ca2+ in cardiac dynamics. Over the past two decades, sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) modulators have been studied as potential chemotherapy agents because of their Ca2+-mediated pan-cancer lethal effects. Instead, recent evidence suggests that SERCA inhibition suppresses oncogenic Notch1 signaling emerging as an alternative to γ-secretase modulators that showed limited clinical activity due to severe side effects. In this review, we focus on how SERCA inhibitors alter Notch1 signaling and show that Notch on-target-mediated antileukemia properties of these molecules can be achieved without causing overt Ca2+ cellular overload.

Blockade of Oncogenic NOTCH1 with the SERCA Inhibitor CAD204520 in T Cell Acute Lymphoblastic Leukemia

The identification of SERCA (sarco/endoplasmic reticulum calcium ATPase) as a target for modulating gain-of-function NOTCH1 mutations in Notch-dependent cancers has spurred the development of this compound class for cancer therapeutics. Despite the innate toxicity challenge associated with SERCA inhibition, we identified CAD204520, a small molecule with better drug-like properties and reduced off-target Ca2+ toxicity compared with the SERCA inhibitor thapsigargin. In this work, we describe the properties and complex structure of CAD204520 and show that CAD204520 preferentially targets mutated over wild-type NOTCH1 proteins in T cell acute lymphoblastic leukemia (T-ALL) and mantle cell lymphoma (MCL). Uniquely among SERCA inhibitors, CAD204520 suppresses NOTCH1-mutated leukemic cells in a T-ALL xenografted model without causing cardiac toxicity. This study supports the development of SERCA inhibitors for Notch-dependent cancers and extends their application to cases with isolated mutations in the PEST degradation domain of NOTCH1, such as MCL or chronic lymphocytic leukemia (CLL).

Chronobiology of acute pancreatitis in a single Italian centre

OBJECTIVE

Seasonal variation may occur in many different diseases hence influencing awareness in clinical practice. This study aimed to establish seasonal variations of acute pancreatitis by using a validated chronobiological analysis.

PATIENTS AND METHODS

All cases of acute pancreatitis consecutively observed in fifteen years, i.e., from January 2003 to December 2017, at St. Anna University Hospital of Ferrara, Italy, were included in this study. Accurate statistical and logistic regression analyses were applied to our database.

RESULTS

A total number of 1883 consecutive cases of acute pancreatitis were observed. A significant peak was identified in the summer period (p=0.014). Patient stratification, according to age, showed that elderly people had an increased incidence of acute pancreatitis in autumn and summer (being the biliary stone disease the main cause, p=0.011) vs. other seasons (p=0.003). Mortality occurred more prominently in males vs. females, although the latter gender was more prone to acute pancreatitis (p=0.017).

CONCLUSIONS

In a single centre of Northern East of Italy, we demonstrated that acute pancreatitis had a clear seasonal variation with a prominent incidence during summer. Various associated factors could contribute to this chronobiological pattern, including gender, age, and biliary stone disease.

ILF2 Is a Regulator of RNA Splicing and DNA Damage Response in 1q21-Amplified Multiple Myeloma

Amplification of 1q21 occurs in approximately 30% of de novo and 70% of relapsed multiple myeloma (MM) and is correlated with disease progression and drug resistance. Here, we provide evidence that the 1q21 amplification-driven overexpression of ILF2 in MM promotes tolerance of genomic instability and drives resistance to DNA-damaging agents. Mechanistically, elevated ILF2 expression exerts resistance to genotoxic agents by modulating YB-1 nuclear localization and interaction with the splicing factor U2AF65, which promotes mRNA processing and the stabilization of transcripts involved in homologous recombination in response to DNA damage. The intimate link between 1q21-amplified ILF2 and the regulation of RNA splicing of DNA repair genes may be exploited to optimize the use of DNA-damaging agents in patients with high-risk MM.

Omics as a potential tool to identify biomarkers and to clarify the mechanism of chronic pain development

Aims

The present study aims to identify the underlying mechanisms in the acute to chronic pain transition. Acute pain is a physiological response to an experience of noxious stimuli that can progress to chronic, becoming a disease. The negative consequences as personal suffering, reduction in physical function, maladaptive behaviours, reduction of productivity, make this condition a central and common problem affecting individuals and the society. After an acute damage, pain in some cases persists, being the process attributed to different causes, in particular persistent tissue and neuronal damages, central neuroplastic changes, psychosocial factors.

Methods

The techniques actually used to investigate acute and chronic pain offer only a partial explanation of the process and in addition, the obtained results are often far away from the possibility to lead some benefits in the clinical practice. Omics technologies could be the right way to detect biomarkers explaining these mechanisms. Our previous study examined epigenetic and pharmacogenetic aspects of acute and chronic pain in a large group of patients. Other omic approaches, such as metabolomics and glycomics, could help to (1) better identify metabolites that can serve as chronic pain development or side effects therapy biomarkers and to (2) better understand new insights involved into the pathophysiological mechanism that drives from acute to chronic pain. SNPs, DNA methylation, miRNA analyses, expression and protein assays on the identified pathway would than clarify the causative molecular mechanisms. In addition, linking these results to clinical evaluation of the central sensitization processes through algometry in nociceptive and neuropathic pain patients may reveal crucial clinical and pharmacological implications.

Conclusions

Our project will be implemented by omic technologies in different chronic pain patient cohorts (acute low back pain vs chronic low back pain patients and chronic postsurgical pain patients) in order to evaluate new possible pathophysiological mechanism with special focus in central sensitization.

Down-regulation of EZH2 expression in myelodysplastic syndromes

EZH2 genetic mutations are common in myelodysplastic syndrome (MDS), which implies that this gene has a pathophysiological role in the disease. To further characterize molecular alterations of EZH2, and their potential prognostic impact in MDS, we assessed EZH2 RNA expression in primary bone marrow CD34+ cells from 78 patients. We found that 47% of patients have reduced EZH2 expression compared to normal controls. Further analyses revealed that EZH2 is significantly underexpressed in patients bearing chromosome 7 or 7q deletions (7-alt) when compared to controls, diploid patients, and patients with other cytogenetic alterations (p<0.05). In survival analysis, we found a non-significant trend toward overall survival (OS) being better among patients with EZH2 underexpression (median OS 55 vs. 36 months; p=0.71). Importantly, this trend became significant when the analysis was restricted to the subset of cases without alterations in chromosome 7 (62 vs. 36 months; p=0.033). Furthermore, our previous work has identified a spectrum of innate immune genes in MDS CD34+ cells that are deregulated via abnormal promoter histone methylation. Because EZH2 is a key regulator of histone methylation, we assessed the relationship between deregulation of these genes and EZH2 underexpression. We observed that the mRNA levels of 11 immune genes were higher in the EZH2 underexpression group and that immune gene expression was significantly higher in patients with concomitant EZH2 underexpression and KDM6B (also known as JMJD3, an H3K27 demethylase) overexpression. Taken together, these data indicate that EZH2 underexpression may have unique impact on the molecular pathogenesis and prognosis in MDS and be an important marker for patients without chromosome 7 alteration.

Abstract 976: Metabolic eradication of treatment resistant cancer stem cells in pancreatic tumors: A clonal tracking-based platform for identifying the best personalized treatment

Pancreatic ductal adenocarcinoma (PDAC) continues to have a poor prognosis despite new drugs advancing to the clinic.

We recently characterized a population of cells able to survive the genetic and pharmacologic extinction of oncogenic pathways and demonstrated that the surviving cells (SC) are tumor stem cells (CSC) able to remain in a quiescent state for months before relapsing. In-depth transcriptomics and metabolomics analyses revealed SCs to exhibit different metabolic features compared to the bulk of tumor cells. Specifically, SC relied on mitochondrial respiration (OXPHOS) and displayed impaired glycolytic capacity. In accord with their decreased dependence on glycolysis these SC were highly sensitive to OXPHOS inhibitors, which prevented tumor recurrence.

Notably, preliminary results in patients suggest that SC resistant to conventional chemoradiation also have similar features. We analyzed specimens after neoadjuvant treatment and observed dormant cells positive for CSC markers and characterized by an increased mitochondrial mass. Evaluation of TMA of hundreds of treated tumors revealed that high mitochondrial content is a common feature of SC. Furthermore, functional metabolic characterization of human cells resistant to gemcitabine revealed that SC have a severely impaired glycolytic reserve, closely resembling mouse SC. Based on these findings, we posit that OXPHOS inhibitors may be an effective adjuvant therapy to eradicate resistant cells in patients.

To validate the efficacy of OXPHOS inhibition, we developed a new platform to study tumor evolution in response to treatments based on clonal tracking. Lentivirus-based systems have been extensively used as a tool to investigate the clonal dynamics, but they have been limited by lack of sensitivity and the impossibility of tracking identical clones in different animals. Here, using a new version of the barcoded technology coupled with deep-sequencing, we track hundreds of thousands of clones at the single-cell level. We generated patient-derived xenograft animal cohorts in which tumors were clonal replicas of each other (each tumor is maintained by the same clones of all other tumors), representing a unique tool to evaluate responses to treatments. More importantly, resistant tumor clones generated in vivo can be isolated and fully characterized and compared to pre-treatment clones to identify new mechanisms of resistance.

Our integrated analysis paves the way for new therapeutic strategies for patients to eradicate treatment-resistant CSC by specifically targeting their unique metabolism. In addition, our clonal tracking-based platform monitoring the efficacy of different treatments in eradicating resistant clones represents an unprecedented tool for exploring treatment responses at the single-cell level, which will help guide the development of personalized treatments.

Citation Format: Denise Corti, Alessandro Carugo, Seth Sahil, Matteo Marchesini, Piergiorgio Pettazzoni, Luigi Nezi, Tessa Green, Joseph R Marszalek, Maria Emilia Di Francesco, Timothy P Heffernan, Giulio F Draetta, Andrea Viale. Metabolic eradication of treatment resistant cancer stem cells in pancreatic tumors: A clonal tracking-based platform for identifying the best personalized treatment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 976. doi:10.1158/1538-7445.AM2015-976

Abstract PR13: Pancreatic tumor stem cells resistant to inhibition of oncogenic signaling are dependent on mitochondrial function

Pancreatic ductal adenocarcinoma (PDAC) continues to have a poor prognosis despite extensive characterization of underlying genetic lesions. Although KRAS mutation is a signature driver event required for tumor development and maintenance, all the attempts made to target oncogene-driven signaling pathways have been met with minimal impact on survival and tumors eventually relapse, suggesting that ablation of oncogenic pathways fails to eradicate tumor cells. We used a genetically engineered mouse model of PDAC in which we could control the expression of mutant KRAS in a time- and tissue-specific manner to study the effects of ablating oncogenic signaling on PDAC cells. As previously described (Ying et al. 2012), this model showed rapid tumor growth when KRAS was expressed, followed by robust tumor regression upon oncogene ablation. However a small population of tumor cells survive genetic and pharmacological inactivation of KRAS. These surviving cells are tumor stem cells able to remain in a quiescent state for months before repopulating the original tumor upon reactivation of KRAS signaling. In depth transcriptomic and metabolomic analyses revealed surviving cells have different metabolic features with respect to the bulk of tumor cells, showing a prominent expression of genes governing mitochondrial function, β-oxidation and autophagy, as well as strong reliance on mitochondrial respiration, yet these cells also displayed impaired glycolytic capacity. In accord with their decreased dependence on glycolysis for cellular energetics and their complete absence of glycolytic reserve, these PDAC surviving tumor stem cells show high sensitivity to oxidative phosphorylation inhibitors, which prevented tumor recurrence. Our integrated analysis paves the way for new therapeutic strategies combining KRAS signaling and oxidative phosphorylation inhibition to completely eradicate pancreatic ductal adenocarcinoma.

This abstract is also presented as Poster A87.

Citation Format: Andrea Viale, Piergiorgio Pettazzoni, Costas Lyssiotis, Haoqiang Ying, Nora Sánchez, Matteo Marchesini, Alessandro Carugo, Tessa Green, Sahil Seth, Virginia Giuliani, Timothy Heffernan, Alec Kimmelman, Huamin Wang, Jason Fleming, Lewis Cantley, Ronald DePinho, Giulio Draetta. Pancreatic tumor stem cells resistant to inhibition of oncogenic signaling are dependent on mitochondrial function. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr PR13.

Abstract A87: Pancreatic tumor stem cells resistant to inhibition of oncogenic signaling are dependent on mitochondrial function

This abstract is also being presented as a short talk in Session 7: New Therapies. A full abstract is printed in the Proffered Abstracts section (PR13) of the Conference Proceedings.

Citation Format: Andrea Viale, Piergiorgio Pettazzoni, Costas Lyssiotis, Haoqiang Ying, Nora Sánchez, Matteo Marchesini, Alessandro Carugo, Tessa Green, Sahil Seth, Virginia Giuliani, Timothy Heffernan, Alec Kimmelman, Huamin Wang, Jason Fleming, Lewis Cantley, Ronald DePinho, Giulio Draetta. Pancreatic tumor stem cells resistant to inhibition of oncogenic signaling are dependent on mitochondrial function. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A87.

Telomere dysfunction drives aberrant hematopoietic differentiation and myelodysplastic syndrome

Myelodysplastic syndrome (MDS) risk correlates with advancing age, therapy-induced DNA damage, and/or shorter telomeres, but whether telomere erosion directly induces MDS is unknown. Here, we provide the genetic evidence that telomere dysfunction-induced DNA damage drives classical MDS phenotypes and alters common myeloid progenitor (CMP) differentiation by repressing the expression of mRNA splicing/processing genes, including SRSF2. RNA-seq analyses of telomere dysfunctional CMP identified aberrantly spliced transcripts linked to pathways relevant to MDS pathogenesis such as genome stability, DNA repair, chromatin remodeling, and histone modification, which are also enriched in mouse CMP haploinsufficient for SRSF2 and in CD34(+) CMML patient cells harboring SRSF2 mutation. Together, our studies establish an intimate link across telomere biology, aberrant RNA splicing, and myeloid progenitor differentiation.

Genetic events that limit the efficacy of MEK and RTK inhibitor therapies in a mouse model of KRAS-driven pancreatic cancer

Mutated KRAS (KRAS*) is a fundamental driver in the majority of pancreatic ductal adenocarcinomas (PDAC). Using an inducible mouse model of KRAS*-driven PDAC, we compared KRAS* genetic extinction with pharmacologic inhibition of MEK1 in tumor spheres and in vivo. KRAS* ablation blocked proliferation and induced apoptosis, whereas MEK1 inhibition exerted cytostatic effects. Proteomic analysis evidenced that MEK1 inhibition was accompanied by a sustained activation of the PI3K-AKT-MTOR pathway and by the activation of AXL, PDGFRa, and HER1-2 receptor tyrosine kinases (RTK) expressed in a large proportion of human PDAC samples analyzed. Although single inhibition of each RTK alone or plus MEK1 inhibitors was ineffective, a combination of inhibitors targeting all three coactivated RTKs and MEK1 was needed to inhibit proliferation and induce apoptosis in both mouse and human low-passage PDAC cultures. Importantly, constitutive AKT activation, which may mimic the fraction of AKT2-amplified PDAC, was able to bypass the induction of apoptosis caused by KRAS* ablation, highlighting a potential inherent resistance mechanism that may inform the clinical application of MEK inhibitor therapy. This study suggests that combinatorial-targeted therapies for pancreatic cancer must be informed by the activation state of each putative driver in a given treatment context. In addition, our work may offer explanative and predictive power in understanding why inhibitors of EGFR signaling fail in PDAC treatment and how drug resistance mechanisms may arise in strategies to directly target KRAS.

Oncogene ablation-resistant pancreatic cancer cells depend on mitochondrial function

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in western countries, with a median survival of 6 months and an extremely low percentage of long-term surviving patients. KRAS mutations are known to be a driver event of PDAC, but targeting mutant KRAS has proved challenging. Targeting oncogene-driven signalling pathways is a clinically validated approach for several devastating diseases. Still, despite marked tumour shrinkage, the frequency of relapse indicates that a fraction of tumour cells survives shut down of oncogenic signalling. Here we explore the role of mutant KRAS in PDAC maintenance using a recently developed inducible mouse model of mutated Kras (Kras(G12D), herein KRas) in a p53(LoxP/WT) background. We demonstrate that a subpopulation of dormant tumour cells surviving oncogene ablation (surviving cells) and responsible for tumour relapse has features of cancer stem cells and relies on oxidative phosphorylation for survival. Transcriptomic and metabolic analyses of surviving cells reveal prominent expression of genes governing mitochondrial function, autophagy and lysosome activity, as well as a strong reliance on mitochondrial respiration and a decreased dependence on glycolysis for cellular energetics. Accordingly, surviving cells show high sensitivity to oxidative phosphorylation inhibitors, which can inhibit tumour recurrence. Our integrated analyses illuminate a therapeutic strategy of combined targeting of the KRAS pathway and mitochondrial respiration to manage pancreatic cancer.

Mortality and causes of death in Italian persons with haemophilia, 1990-2007

Although a number of studies have analysed so far the causes of death and the life expectancy in haemophilic populations, no investigations have been conducted among Italian haemophilia centres. Thus, the aim of this study was to investigate mortality, causes of deaths, life expectancy and co-morbidities in Italian persons with haemophilia (PWH). Data pertaining to a total of 443 PWH who died between 1980 and 2007 were retrospectively collected in the 30 centres who are members of the Italian Association of Haemophilia Centres that chose to participate. The mortality rate ratio standardized to the male Italian population (SMR) was reduced during the periods 1990-1999 and 2000-2007 such that during the latter, death rate overlapped that of the general population (SMR 1990-1999: 1.98 95% CI 1.54-2.51; SMR 2000-2007: 1.08 95% CI 0.83-1.40). Similarly, life expectancy in the whole haemophilic population increased in the same period (71.2 years in 2000-2007 vs. 64.0 in 1990-1999), approaching that of the general male population. While human immunodeficiency virus infection was the main cause of death (45%), 13% of deaths were caused by hepatitis C-associated complications. The results of this retrospective study show that in Italian PWH improvements in the quality of treatment and global medical care provided by specialized haemophilia centres resulted in a significantly increased life expectancy.

Effect of tidal volume and respiratory rate on the power of breathing calculation

BACKGROUND

The power of breathing (PoB) is used to estimate the mechanical workload of the respiratory system. Aim of this study was to investigate the effect of different tidal volume-respiratory rate combinations on the PoB when the elastic load is constant. In order to assure strict control of the experimental conditions, the PoB was calculated on an airway pressure-volume curve in mechanically ventilated patients.

METHODS

Ten patients received three different tidal volume-respiratory rate combinations while minute ventilation was constant. Respiratory mechanics, PoB and its elastic and resistive components were calculated. Alternative methods to estimate the elastic workload were assessed: elastic work of breathing per litre per minute, elastic workload index (the square root of elastic work of breathing multiplied by respiratory rate) and elastic double product of the respiratory system (the elastic pressure multiplied by respiratory rate).

RESULTS

Despite constant elastance and minute ventilation, the elastic PoB showed an increment greater than 200% from the lower to the greater tidal volume, accounting for approximately 80% of the whole PoB increment. On the contrary, elastic work of breathing per litre per minute, elastic workload index and elastic double product did not change.

CONCLUSION

Changes in breathing pattern markedly affect the PoB despite constant mechanical load. Other indexes could assess the elastic workload without tidal volume dependence. Power of breathing use should be avoided to compare different mechanical loads or efficiencies of the respiratory muscles when tidal volume is variable.

Effect of breathing pattern on the pressure-time product calculation

BACKGROUND

The pressure-time product (PTP) is often used to compare conditions with different breathing patterns. Being the pressure-time product calculated with pressures changes over a minute, mechanical load and inspiration time per minute should be its main determinants. The aim of this study was to investigate if the method of PTP computation is affected by the breathing pattern when mechanical load and inspiratory time per minute are constant.

METHODS

Respiratory mechanics and the PTP developed by the ventilator were calculated in 10 mechanically ventilated patients at three different respiratory rate/tidal volume combinations, provided that minute ventilation and inspiratory time per minute were constant.

RESULTS

The static elastance did not change at different tidal volumes. Despite the constant elastic load over a minute, the elastic PTP showed an increment greater than 200% from the higher to the lower respiratory rate, responsible for approximately 80% of the whole PTP increment. On the contrary a 'corrected' elastic PTP (calculated using the square root of the elastic pressure-time area), the elastic double product of the respiratory system and the mean elastic pressure per minute, did not significantly change.

CONCLUSIONS

Changes in breathing pattern markedly affected the PTP independently by the mechanical load and the inspiratory time per minute. In these conditions it could not correctly estimate the metabolic cost of breathing. The use of a 'corrected' PTP, the mean inspiratory pressure per minute or the double product of the respiratory system, could overcome this limitation.

Oligofructose does not affect the development of type 1 diabetes mellitus induced by dietary proteins in the diabetes-prone BB rat model

BACKGROUND

Prevention of Type 1 diabetes mellitus (T1DM), a major childhood chronic disease with rapidly increasing incidence, is an urgent topic of research. We investigated whether 5% oligofructose (OF) as compared to 5% cellulose had a protective effect against diet-induced T1DM in the diabetes-prone BioBreeding (BB) rat model.

METHODS

Groups of BB rats were fed the experimental diets from weaning. The diets were a cereal-based rodent diet (diabetogenic, positive control) and semi-synthetic rodent diets containing hydrolysed casein (non-diabetogenic, negative control), soy or whey as the sole protein source and 5% cellulose as fibre source. In additional groups fed soy and whey protein, the fibre source was 5% OF. T1DM incidence up to the age of 160 days was recorded applying biochemical and morphological criteria. Physiological effects of fibre were assessed through the analysis of biochemical parameters in plasma and of the protein/DNA ratio in intestinal mucosa.

RESULTS

T1DM incidence was diet-dependent. Cereal-, soy- and whey-based diets were significantly more diabetogenic than the hydrolysed casein-based diet. Five per cent OF did not affect the incidence of T1DM induced by either soy or whey proteins as compared to cellulose, nor induce any of the biological effects attributed to a fermentable fibre.

CONCLUSIONS

In the BB rat model, 5% OF in the diet did not have any protective effects against diet-induced T1DM. The present data do not suggest dietary OF as a promising approach for the dietary prevention of T1DM.

Relationships between age, mammographic features and pathological tumour characteristics in non-palpable breast cancer

Non-palpable breast cancers are often in situ or smaller and have less nodal and distant metastases than palpable lesions. They represent a heterogeneous group of tumours, which may have different prognostic behaviour. We analysed a retrospective series of 982 non-palpable breast cancers assessed histologically at the National Cancer Institute of Milan from 1985 to 1995, following pre-operative mammography-guided localization. The association between mammographic data (parenchymal pattern and findings), patient age and tumour histology was investigated by review of clinical records and statistical modelling. We also investigated the association between the presence or absence of microcalcification as a mammographic finding and pathological tumour characteristics (tumour size, axillary nodes status and grading) or receptor status for oestrogen (ER) and progesterone (PgR). In situ disease or invasive tumour with an intraductal component, whether extensive or not, were commoner in young women and mammography more frequently showed a dense parenchymal pattern and microcalcifications in these cases. In older women (55 years or more), a fatty breast pattern, nodular opacities with or without microcalcifications, and invasive tumours of the ductal, lobular, mixed or other types were closely related. When the relationships between mammographic findings, pathological tumour characteristics and receptor status were investigated for invasive cancers, there was an association between the presence of microcalcifications and less favourable tumour characteristics.

CD4(+) T cell clones producing both interferon-gamma and interleukin-10 predominate in bronchoalveolar lavages of active pulmonary tuberculosis patients

The pattern of cytokine production in T cell clones derived from bronchoalveolar lavages (BAL) of active pulmonary tuberculosis (TB) patients was analyzed in clones obtained by limiting dilution procedures which expand with high efficiency either total T lymphocytes, independently of their antigen-recognition specificity, or Mycobacterium tuberculosis-specific T cells. BAL-derived clones, representative of CD4(+) cells from five patients with active TB, produced significantly higher amounts of IFN-gamma than BAL-derived CD4(+) clones from three inactive TB donors or four controls (with unrelated, noninfectious pathology). Average IL-4 and IL-10 production did not differ significantly in the three groups. Although these data suggest a predominant Th1 response to M. tuberculosis infection in the lungs, the majority of BAL-derived CD4(+) clones produced both IFN-gamma and IL-10 and the percentage of clones with this pattern of cytokine production was significantly higher in clones derived from BAL of active TB patients than from controls. Only rare clones derived from peripheral blood (PB)-derived CD45RO(+) CD4(+) T cells of both patients (nine cases) and controls (four cases) produced both IFN-gamma and IL-10; instead, the IL-10-producing clones derived from PB T cells most often also produced IL-4, displaying a typical Th2 phenotype. Higher average amounts of IFN-gamma and IL-10 were produced by BAL-derived CD8(+) clones of four active TB patients than of four controls, although the frequency of CD8(+) clones producing both IFN-gamma and IL-10 was lower than that of CD4(+) clones. The M. tuberculosis-specific BAL-derived T cell clones from three active TB patients were almost exclusively CD4(+) and produced consistently high levels of IFN-gamma often in association with IL-10, but very rarely with IL-4. Unlike the BAL-derived clones, the M. tuberculosis-specific clones derived from PB CD45RO(+) CD4(+) T cells of three different active TB patients and two healthy donors showed large individual variability in cytokine production as well as in the proportion of CD4(+), CD8(+), or TCR gamma/delta(+) clones. These results indicate the predominance of CD4(+) T cells producing both the proinflammatory cytokine IFN-gamma and the anti-inflammatory cytokine IL-10 in BAL of patients with active TB.

[Non-invasive lymphatic staging of lung neoplasms: comparative study with computerized tomography and endoscopic ultrasonography]

INTRODUCTION

A prospective comparative study with pathology was performed at the National Cancer Institute, Milan, to assess the clinical value of Computed Tomography (CT) and endoscopic ultrasound (EUS) for nodal staging in lung cancer.

MATERIAL AND METHODS

In three years, 71 patients with histological diagnosis of non-small-cell lung cancer were operated on. They underwent CT and EUS examinations to identify mediastinal lymphadenopathies after major nodal involvement had been excluded by chest X-ray. Diagnostic staging was completed in two weeks prior to treatment. Patients received complete tumor removal and radical lymphadenectomy (55 patients), invasive staging with node resection and sampling (11 patients), or mediastinoscopy (5 patients). Blinded interpretation of CT alone, EUS alone, and CT and EUS together were performed, with systematic correlation of imaging findings and pathological results.

RESULTS

The frequency of mediastinal involvement was 42.2%. A total of 329 nodal stations were dissected or sampled and 755 lymph nodes were examined at histology. On a per-station basis, CT had greater sensitivity (74%) than EUS (56%), but EUS was more specific (83.4% vs 92.7%). The accuracy rates of the two techniques were similar (CT 81%, EUS 83%). A site by site analysis showed highest sensitivity (100%) in the lower right paratracheal nodes for CT, and in the superior left paratracheal and subcarinal nodes for EUS. When the EUS and CT images were studied together by specialists on a per-station basis, sensitivity, specificity, and accuracy increased to 85%.

CONCLUSIONS

Endoscopic ultrasound should be part of the routine preoperative diagnostic approach to non-small-cell lung cancer, because of its high specificity. Results can be improved when EUS and CT are combined, which suggests that these imaging modalities should be used together in selected patients for the noninvasive staging of non-small-cell lung cancer to identify local lymphatic spread.

Superoxide anion in human semen related to seminal parameters and clinical aspects

OBJECTIVE

To study the possible presence of extracellular superoxide anion (O2-) in untreated semen of normal and pathological subjects and to determine the possible relationship between superoxide anion levels, number of seminal leukocytes (WBCs) and seminal parameters.

PATIENTS

Semen samples were analyzed from fertile normospermic subjects (n = 20) and patients (n = 132) attending the Outpatient Department of the 5th Medical Clinic.

MAIN OUTCOME MEASURE

We evaluated superoxide anion levels by monitoring the reduction of cytochrome c.

RESULTS

O2- was detected in 55.0% of fertile normospermic subjects. Both the percentage of subjects in whom O2- was detected and the mean values +/- SD of O2- were significantly higher in the male partners of infertile couples, in subjects with varicocele, and in subjects with positive sperm culture than normospermic subjects. No variations were seen in vasectomized subjects or in patients with past cryptorchidism. A high correlation was observed between O2- levels and WBCs (rs = 0.58), nonrapid, immotile sperm (rs = 0.64), percentage decrease of motility within a specified time frame (2 to 6 hours) (rs = 0.73), and sperm abnormalities (rs = 0.49).

CONCLUSIONS

Superoxide anion in untreated semen is produced by WBCs and atypical and nonrapid, immotile sperm. A significant increase of superoxide anion was detected in the male partners of infertile couples and in some selected andrological conditions. The toxic effect of superoxide anion on sperm cells is dependent on the time of exposure and superoxide anion concentration.