Hadrontherapy for intra- or para-cardiac tumors: evaluation of cardiac radiation dose distribution and acute cardiac effects

Background

There is growing interest in the possibility of using X-rays and hadrons (protons and carbon ions) for antiarrhythmic purposes both at the ventricular and the atrial level, but knowledge about the effects on cardiac tissue outside the target is still limited. Hadron therapy has the dosimetric advantage over photons of a greater ability to concentrate high doses on the target while minimizing the off-target dose. Oncological studies have shown a linear relationship between the mean total heart dose (Dm-heart) of X-rays and the long-term risk of heart damage, particularly when the Dm-heart is>5 Gray (Gy).

Objectives

We designed a prospective study aimed at investigating the effect of heavy particles on cardiac structure and function and on cardiac rhythm in patients undergoing hadrontherapy for intra or para-cardiac tumors.

Methods

Patients candidates to hadrontherapy with a mean predicted cardiac dose grather than zero underwent close cardiological monitoring including blood pressure detection, 12-lead ECG, 12-lead Holter ECG (including time-domain indices of heart rate variability in all cases and Brugada leads in selected cases), cardiac US and cardiac (troponin and natriuretic peptides) and inflammatory biomarkers. These assessments were obtained at baseline, during (ECG and biomarkers only) and at the end of the hadrontherapy cycle, and then every 3–6 months as appropriate. Physicists and radiotherapists collaborated to implement a robust optimization of the treatment plan aimed at minimizing cardiac dose. We present the results of the monitoring up to the end of the hadrontherapy.

Results

17 consecutive patients (56±18 years, range 20–77 years, 59% male) have been enrolled to date, including 3 cases (18%) of intra-cardiac tumors (2 primary and 1 metastatic), who have undergone to 16±6 sessions of radiotherapy each, in 71% of cases with respiratory gating during delivery. Most patients (76%) were treated with carbon ions, the remaining with protons (mean total dose on the neoplastic target 51.8±10.7 Gy, from 2 to 4.2 Gy per fraction). Sixty-one percent of patients had ≥1 cardiovascular risk factor, 6% had a known heart disease (valvular cardiomyopathy despite aortic valve replacement with biological prosthesis and post-surgical pericarditis). The mean dose on the whole heart was 3.58±2.05 Gy, the maximum dose was 33.78±23.99 Gy, with a very variable dose distribution on cardiac substructures depending on the tumor site (table). At the end of the scheduled radiotherapy sessions (24±9 days), no significant changes were observed in cardiac function, cardiac rhythm, ventricular repolarization, biomarkers and autonomic indices.

Conclusions

Hadrontherapy with protons and carbon ions aimed at the treatment of para-cardiac or intra-cardiac tumors allowed to maintain a low heart Dm and showed no signs of acute cardiac toxicity. The collection of potential cardiac effects in the medium and long term is ongoing.

Funding Acknowledgement

Type of funding sources: None.

Long-term outcome of patients with cardiolaminopathy undergoing defibrillator implantation: single-center experience

Background

Mutations in the LMNA gene are associated with a high arrhythmic risk. The history of the disease in patients undergoing ICD implantation is poorly characterized.

Purpose

To evaluate the phenotype of patients with cardiolaminopathy at the time of first ICD implantation, the incidence, characteristics and timing of ventricular arrhythmias (VAs) during follow up and the predictive value of the European score (that assigns a point each to non-sustained VT (NSVT), left ventricular ejection fraction (LVEF)<45% at first contact, male sex and non-missense mutations) and of the Wahbi score (that also includes conduction disturbances) for both VAs and heart failure (HF) related outcomes.

Methods

Patients were identified retrospectively. Clinical and device data were collected at baseline and during follow-up.

Results

We identified 26 patients (54% male, 42±8 years, 31% with familial history of sudden cardiac death, 31% with non-missense mutation) undergoing ICD implantation, 96% in primary prevention, 47% with single chamber ICD, 38% with dual chamber ICD. At the time of implantation, 30% had skeletal muscle involvement, 15% history of syncope, 4% of cardiac arrest, 62% previous NSVT. Also, 38% had a history of supraventricular arrhythmias and 61% had AV conduction disturbances. LVEF was 41±11%, 35% were in NYHA class ≥2, the mean European and Wahbi scores were 2.1±0.8 and 18.2±8.9, respectively. During 8.3±5 years, 15% were transplanted, 8% died due to HF, 4% underwent LVAD implantation, despite 31% having received an upgrade to CRT-D. Appropriate device interventions occurred in 46% of patients with a median time to first event of 29 months (IQR 13–93), for a total of 137 ATP, 51% of which effective (median 3ATP/patient, IQR 1–8) and of 26 shocks, 96% of which effective (median 2 shocks/patient, IQR 1–3); 12% had an arrhythmic storm. The first treated arrhythmia was a polymorphic VT/VF in 17%, a monomorphic VT in the others (medium cycle length 293±37 msec). Survival free from appropriate ICD interventions at 1 and at 5 years was 75% and 19% respectively in case of a European score ≥3 vs 94% and 82% in case of a score <3 (Logrank test p<0.01), 72% and 46% in case of Wahbi score ≥30 vs 100% and 86% with score <30 (p<0.01), with no differences in terms of death/transplant (figure). At last follow-up, 92% of patients a were taking beta-blocker, 42% amiodarone, 8% sotalol, 4% flecainide, 8% mexiletine. Also, 4% had undergone invasive VT ablation, 8% bilateral cardiac sympathetic denervation.

Conclusions

Patients with cardiolaminopathy are at a high risk of both arrhythmic and heart failure progression over the first decade after implantation of the first ICD. A European score ≥3 identifies patients with 5-year shock/ATP free survival of less than 20% but does not predict death/transplantation. The first arrhythmic event in these patients is more frequently a rapid monomorphic VT with modest ATP efficacy.

Funding Acknowledgement

Type of funding sources: None.

Long-term follow-up of heart transplant patients treated with permanent pacemaker: a monocentric study

Funding Acknowledgements

Type of funding sources: None.

Background and purpose

Permanent pacemaker implantation (PPMi) is needed in about 5% of patients following heart transplant (HTx) primarily due to sinus node dysfunction (SND), which commonly occurs in an early phase, or to atrio-ventricular block (ABV), which is common later on. Currently, data on rate of ventricular pacing (VP) is lacking and little is known on long-term outcomes after PPMi.

Methods

This was a retrospective, monocentric study. Among 1123 patients treated with HTx, all with biatrial technique, from november 1985 to march 2019 at our institution, 61 (5.4%) patients needed PPMi. PM parameters, clinical and echocardiographic data were collected at 1 month and at 1-3-5-10 years follow-up. The primary aim was to analyse the percentage of right ventricular pacing in the overall population and in subgroups stratified by the timing of PPMi and by pacing indication. Secondary endpoints were to analyze long-term outcomes according to the percentage of ventricular pacing and to the type of implanted PM (single vs. dual chamber). 

Results

Among patients treated with PPMi (68.9% single-chamber), 62.2% were implanted for SND and 36% for AVB. Early PPMi (< 3 months after HTx), occurred in 34.4% of patients, mainly due to SND, while late PPMi (> 3 months after HTx) occurred in 65,6% with an equal distribution between SND and AVB. Median follow-up time from HTx was 140 months and 82 months from PPMi. Overall mean rate of VP was 21%. Rate of VP was higher in patients implanted early rather than late after HTx, both at 1 month (91% vs 2%, P = 0,002) and at 1 year after the procedure (43 vs 1, P = 0,037). Patients with AVB had a greater rate of VP compared to those implanted for SND, irrespective of timing of implantation and these findings were still present at 3 and 5 years follow-up (62 vs 1%, P = 0,011 at 3 years and 80 vs 6%, P = 0,002 at 5 years). VP declined progressively after PPM implantation. No differences were observed in terms of 10-years mortality between early vs late PPMi, dual vs single-chamber and mean VP > 21% vs ≤ 21%.

Conclusions

Patients treated with PPMi after HTx show on average low percentage of VP over long-term follow-up. AV block indication and early implantation are associated with a higher percentage of VP. The rate of VP, the timing of PPMi and the use of single vs dual chamber PM do not affect overall prognosis or left ventricular systolic function. Our data may justify implantation of a single-chamber PPM, which bears less complications and procedural time, in the majority of HTx patients needing PPMi.

Identification of suitable mRNAs and microRNAs as reference genes for expression analyses in skin cells under sex hormone exposure

Quantitative RT-PCR is the most accurate technique for the study of gene expression profiles, however, to ensure the accuracy of qPCR results, suitable reference genes are necessary for data normalization. Hormones influence the development and function of skin cells, regulating the expression of genes and miRNAs. Nevertheless, the stability of reference genes after sex hormone treatment has not been thoroughly investigated. In this study, we evaluated the expression of a set of candidate mRNAs and microRNsA (miRNA) as reference genes in keratinocytes (HaCaT cells), primary human fibroblasts and a melanoma cell line (LM-36 cells) under testosterone or 17β-estradiol treatment. Two algorithms, namely geNorm, Best-Keeper, and the comparative ΔCt method were used to evaluate the expression stability of the candidate reference genes. The comprehensive ranking showed that TBP and miR-191-5p are the most stable expressed genes across all cultured cells under hormone treatment. Furthermore, we observed that GAPDH, HPRT1 and U6 snRNA expression may be altered by hormone exposure, thus, these genes are not recommended as reference genes. In conclusion, the present study provides, to the best of our knowledge, the first evaluation of expressed mRNA(s) and miRNA(s) as reference genes in three different types of skin cells under the stimulation of sex hormones.

Advances in pharmacotherapy for cardiac amyloidosis

INTRODUCTION

Amyloidosis is a group of progressive and devastating disorders resulting from extracellular deposition of misfolded proteins into tissues. When deposition of fibrils occurs in cardiac tissues, this systemic disease can lead to a very poor prognosis. Systemic amyloidosis can be acquired [light chain (AL) amyloidosis; AA amyloidosis], or hereditary [transthyretin (ATTR) amyloidosis]. Cardiac disease in amyloidosis is usually secondary to a systemic disease. The diagnosis of cardiac involvement is often delayed and yields an adverse prognosis.

AREAS COVERED

in this review, the authors report current literature on advances in pharmacotherapy for cardiac amyloidosis, mainly focused on AL and ATTR amyloidosis treatment.

EXPERT OPINION

Most pharmacological trials in amyloidosis patients, both AL and TTR, are directed to study the effects of drugs on polyneuropathy. However, since cardiac involvement carries a prominent negative survival impact in amyloidosis patients, future research should be more focused on amyloidosis cardiomyopathy as primary endpoint. Additionally, in AL amyloidosis therapies are mainly derived from experience on multiple myeloma treatment. In this specific setting, possible future research could particularly focus on immunotherapeutic agents able to optimize the standard chemotherapy results and, thus, allowing a larger population of patients to be treated by bone marrow stem cell transplantation.

Analysis of partial volume correction on quantification and regional heterogeneity in cardiac PET

BACKGROUND

The partial volume correction (PVC) of cardiac PET datasets using anatomical side information during reconstruction is appealing but not straightforward. Other techniques, which do not make use of additional anatomical information, could be equally effective in improving the reconstructed myocardial activity.

METHODS

Resolution modeling in combination with different noise suppressing priors was evaluated as a means to perform PVC. Anatomical priors based on a high-resolution CT are compared to non-anatomical, edge-preserving priors (relative difference and total variation prior). The study is conducted on ex vivo datasets from ovine hearts. A simulation study additionally clarifies the relationship between prior effectiveness and myocardial wall thickness.

RESULTS

Simple resolution modeling during data reconstruction resulted in over- and underestimation of activity, which hampers the absolute left ventricular quantification when compared to the ground truth. Both the edge-preserving and the anatomy-based PVC techniques improve the absolute quantification, with comparable results (Student t-test, P = .17). The relative tracer distribution was preserved with any reconstruction technique (repeated ANOVA, P = .98).

CONCLUSIONS

The use of edge-preserving priors emerged as optimal choice for quantification of tracer uptake in the left ventricular wall of the available datasets. Anatomical priors visually outperformed edge-preserving priors when the thinnest structures were of interest.

Partial volume and motion correction in cardiac PET: First results from an in vs ex vivo comparison using animal datasets

BACKGROUND

In a previous study on ex vivo, static cardiac datasets, we investigated the benefits of performing partial volume correction (PVC) in cardiac 18F-Fluorodeoxyglucose(FDG) PET datasets. In the present study, we extend the analysis to in vivo cardiac datasets, with the aim of defining which reconstruction technique maximizes quantitative accuracy and, ultimately, makes PET a better diagnostic tool for cardiac pathologies.

METHODS

In vivo sheep datasets were acquired and reconstructed with/without motion correction and using several reconstruction algorithms (with/without resolution modeling, with/without non-anatomical priors). Corresponding ex vivo scans of the excised sheep hearts were performed on a small-animal PET scanner (Siemens Focus 220, microPET) to provide high-resolution reference data unaffected by respiratory and cardiac motion. A comparison between the in vivo cardiac reconstructions and the corresponding ex vivo ground truth was performed.

RESULTS

The use of an edge-preserving prior (Total Variation (TV) prior in this work) in combination with motion correction reduces the bias in absolute quantification when compared to the standard clinical reconstructions (- 0.83 vs - 3.74 SUV units), when the end-systolic gate is considered. At end-diastole, motion correction improves absolute quantification but the PVC with priors does not improve the similarity to the ground truth more than a regular iterative reconstruction with motion correction and without priors. Relative quantification was not influenced much by the chosen reconstruction algorithm.

CONCLUSIONS

The relative ranking of the algorithms suggests superiority of the PVC reconstructions with dual gating in terms of overall absolute quantification and noise properties. A well-tuned edge-preserving prior, such as TV, enhances the noise properties of the resulting images of the heart. The end-systolic gate yields the most accurate quantification of cardiac datasets.

P5554Follow the light - The prognostic value of late gadolinium enhancement in hypertrophic cardiomyopathy

Background and aim

Hypertrophic cardiomyopathy (HCM) is a genetic based cardiomyopathy with heterogeneous phenotypic expression. Since it is one of the most common cause of sudden cardiac death (SCD) in the young different risk score have been proposed to properly identify the patients that would benefit from a primary prevention with an implantable cardioverter-defibrillator (ICD). ESC guidelines on HCM suggest to estimate the risk of SCD considering clinical and echocardiographic parameters and mention the use of cardiac magnetic resonance (CMR) only in the case of poor echo windows. The aim of the present study-level meta-analysis was to explore the prognostic value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for adverse fatal events.

Methods

We searched PubMed and EMBASE for studies that investigated the prognostic value of LGE in patients with HCM. The outcomes of interest were SCD or aborted SCD, all-cause mortality and cardiovascular (CV) mortality. Random-effects Odds Ratios (ORs) were estimated using a DerSimonian-Laird method with a person-year approach. Moreover, an univariate meta-regression was performed to assess the moderator effect of mean age, LGE % of left ventricle (LV) and gender (expressed as male percentage).

Results

A total of 7 studies (n=3351) were included in the analysis. Mean follow-up was 3±0.63 years. Mean age was 47.7±14.6 years and 56.9% were male. LGE was detected in 1845 (55%) patients with a mean LGE percentage of LV of 7%. The presence of LGE was associated with an increased incidence of SCD or aborted SCD (OR 3.44; 95% CI 2.02–5.86; p<0.001- Figure), all-cause mortality (OR 1.92; 95% CI 1.31–2.81; p<0.001) and CV mortality (OR 3.16; 95% CI 1.77–5.64; p<0.001) compared with the absence of LGE at CMR. The LGE percentage of LV, mean age and gender did not have any moderator effect on the outcomes of interest. However, LGE % of LV was reported only in 4 studies and the absence of any moderator effect of this parameter could be due to a type II error.

Prognostic value of LGE for SCD

Conclusions

The presence of LGE at CMR in patients with HCM exhibited a substantial prognostic value in fatal events and, in particular, in the prediction of SCD. LGE assessment is an effective tool to stratify the arrhythmic risk in HCM. Therefore, it should be considered, especially in borderline cases, to improve the identification of HCM patients who could benefit from ICD implantation.

P5416A single-center, thirty-year experience of heart transplantation: analysis of the evolution of patients profile and long term outcomes

Background

Heart Transplantation is still the gold standard therapy for patients suffering from end-stage cardiomyopathy and has been successfully performed in our center since 1985. Over this 30 years period there has been a significant evolution in patients characteristics and in candidate selection (either as a donor and as recipient) as shown by the recent benchmark from International Society of Heart and Lung Transplantation (ISHLT). Here we analyze the evolution of patients profile in our population and we correlated such evolution to the clinical outcomes and to the overall data from ISHLT.

Materials and methods

Overall 1122 patients underwent heart transplantation at our center from November 19th1985 to date. To analyze the evolution patients profile and donor criteria, patient population was divided in 4 groups according era of transplantation following ISHLT model (Group A from 1985 to 1991; Group B from 1992 to 2003; Group C from 2004 to 2008 and Group D from 2009 to date). Patients characteristics at time of transplantation, donor criteria ad clinical outcomes were analyzed and compared within 4 groups. An overall comparison of our results to the data from ISHLT was also performed.

Results

Overall Kaplan-Meier survival curve correlates favourably with ISHLT data showing a 20 years survival approaching 40%. Patients age at transplantation changed significantly among 4 groups from a median of 49 years (95% CI 47 to 51) in Group A to 54 years (95% CI 50 to 57) in Group D (p<0.001). Likewise donor age also changed significantly from a median of 24 years (95% CI 22 to 28) in Group A to 43 years (95% CI 39 to 47) in group D (p<0.001). Time on waiting list also changed significantly from a median of 115 days (95% CI 94 to 137) in Group A to 293 (95% CI 200 to 401) in Group D (p<0.001). As a marker of evolution of accepted donor criteria also ischemic time changed from 125±52 minutes of Group A to 153±61 minutes of Group D (p<0.001). As showed in Fig 1, Kaplan-Meier survival curves demonstrated a worse 1-year survival in Group D compared to others 3 Group.

Figure 1

Conclusions

The significant changing characteristics of both recipients and donors, over 30 years of activity, had a significant impact in early (1 year) postoperative survival following heart transplantation. Although medium/long term outcomes are still satisfactory in patients surviving at least 1 year, these data clearly suggest a more accurate patients selection and the need of alternative treatment before patients conditions deteriorate while on waiting list for heart transplantation

P619Stress-strain loop area better represents regional myocardial work than pressure-strain loop area in the dyssynchronous and remodelled left ventricle

Background

Pressure-strain-loops (PSL) have been suggested as surrogate parameter of regional myocardial work. However, in left ventricles (LV) with inhomogeneous remodelling, e.g. due to left bundle branch block (LBBB), wall stress may be unevenly distributed. Stress-strain loops (SSL) include information on both regional wall thickness and curvature, and may therefore provide a better surrogate.

Study plan

We therefore compared the correlation of segmental myocardial work estimated through both PSL and SSL to segmental myocardial glucose metabolism as a gold standard, in an animal model of pacing-induced LV remodelling.

Methods

Twelve sheep developed LV dilatation, thinned septum and thickened lateral wall, due to eight weeks of rapid right-atrial and right-ventricular free wall (DDD) pacing (at 180 bpm), causing a LBBB-like dyssynchrony. Invasive LV pressure and echocardiographic speckle tracking based circumferential strain were used to construct PSL. SSL were calculated by considering in addition dynamic changes in segmental myocardial wall thickness and curvature using the formula of Laplace. 18F-fluorodeoxyglucose (FDG)-uptake was measured by positron emission tomography (PET) in absolute values as standardised uptake ratio (SUR). Spatial resolution of PET was improved by ECG- and breathing-gating and using anatomical priors. All imaging was performed during dyssynchronous DDD-pacing and synchronous AAI-pacing (right-atrial pacing only), at baseline (n=3 animals), and after eight weeks of pacing induced remodelling (n=12 animals).

Results

Both at baseline (Fig. A+B) and after 8 weeks (Fig. D+E), switching between AAI and DDD-pacing caused an acute re-distribution of regional myocardial work as measured by both PSL and SSL. In contrast to PSL, however, SSL identified more regional differences among walls in remodelled hearts and showed clearer regional changes when switching between AAI and DDD-pacing. The correlation between regional work, assessed by PSL and SSL, and metabolism by PET, was comparable at baseline (r=0.65 and r=0.64, respectively) (Fig. C). In remodelled hearts after 8 weeks, however, the correlation of regional work assessed by SSL and glucose uptake by PET was significantly higher compared to PSL (r=0.73 vs. r=0.59, respectively; p<0.05) (Fig. F).

Conclusions

Regional myocardial work assessed by stress-strain loops correlates significantly better to regional metabolism as measured by PET glucose uptake, particularly after remodelling. Our findings therefore suggest that integrating information on wall thickness and curvature is essential for the reliable assessment of regional myocardial work, especially in dyssynchronous and remodelled left ventricles.

Expression of TLR4-PTGE2 signaling genes in atherosclerotic carotid plaques and peripheral blood

Toll-like receptor 4 (TLR4)/prostaglandine synthetase 2 (PTGS2) signaling plays a relevant role in atherosclerotic plaque vulnerability. The purpose of this study was to check the gene expression of 6 genes participating to TLR4/PTGS2 signaling (TLR4, PTGS2, ACSL4, PTGER3, PTGER4, and EPRAP) in carotid plaques and blood samples from the same individual and to evaluate these genes as biomarker of plaque progression. We investigated differential gene expression by qRT-PCR in 62 atherosclerotic patients' carotid plaques and corresponding blood sample. A very weak or no correlation was observed in the overall population or analyzing asymptomatic patients. These analyzed genes are most likely not suitable for inclusion in the clinical routine as biomarkers of plaque instability.

Lesion quantification and detection in myocardial (18)F-FDG PET using edge-preserving priors and anatomical information from CT and MRI: a simulation study

Background

The limited spatial resolution of the clinical PET scanners results in image blurring and does not allow for accurate quantification of very thin or small structures (known as partial volume effect). In cardiac imaging, clinically relevant questions, e.g. to accurately define the extent or the residual metabolic activity of scarred myocardial tissue, could benefit from partial volume correction (PVC) techniques.

The use of high-resolution anatomical information for improved reconstruction of the PET datasets has been successfully applied in other anatomical regions. However, several concerns linked to the use of any kind of anatomical information for PVC on cardiac datasets arise. The moving nature of the heart, coupled with the possibly non-simultaneous acquisition of the anatomical and the activity datasets, is likely to introduce discrepancies between the PET and the anatomical image, that in turn might mislead lesion quantification and detection. Non-anatomical (edge-preserving) priors could represent a viable alternative for PVC in this case.

In this work, we investigate and compare the regularizing effect of different anatomical and non-anatomical priors applied during maximum-a-posteriori (MAP) reconstruction of cardiac PET datasets. The focus of this paper is on accurate quantification and lesion detection in myocardial ¹⁸F-FDG PET.

Methods

Simulated datasets, obtained with the XCAT software, are reconstructed with different algorithms and are quantitatively analysed.

Results

The results of this simulation study show a superiority of the anatomical prior when an ideal, perfectly matching anatomy is used. The anatomical information must clearly differentiate between normal and scarred myocardial tissue for the PVC to be successful. In case of mismatched or missing anatomical information, the quality of the anatomy-based MAP reconstructions decreases, affecting both overall image quality and lesion quantification. The edge-preserving priors produce reconstructions with good noise properties and recovery of activity, with the advantage of not relying on an external, additional scan for anatomy.

Conclusions

The performance of edge-preserving priors is acceptable but inferior to those of a well-applied anatomical prior that differentiates between lesion and normal tissue, in the detection and quantification of a lesion in the reconstructed images. When considering bull’s eye plots, all of the tested MAP algorithms produced comparable results.

Thyroid disease prevalence in carabineers deployed in a war theater

The problem of morbidity in deployed military personnel represents a much-debated topic. Because there have been two cases of thyroid cancer in the Tuscania regiment, the aim of the present study was to investigate the prevalence of all types of thyroid disease in a cohort of carabineers. A total of 673 carabineers, including 501 deployed carbineers (DCs) (29-48 years of age) and 172 nondeployed carabineers (NDCs) (29-51 years of age), of the Tuscania regiment were involved in the study. Thyroid volume, percentages of single nodules and multinodular goiter, percentage of autoimmune thyroid disease, and percentages and histological types of thyroid cancer were all measured. No statistical difference between DCs and NDCs was found for any of the data. Furthermore, when we divided DCs into subgroups according to time spent on deployment and time elapsed since the first deployment, we found no differences. However, a high prevalence of thyroid cancer was found in our cohort (2.0% in DCs and 2.5% in NDCs; not significant), and the prevalence of thyroid cancer in nodules in the cohort of carabineers was higher (10.0%) than the prevalence of thyroid cancer in nodules in the civilian population (5.6%, p < 0.001). No differences regarding the prevalence of thyroid diseases were observed when we compared DCs and NDCs, which suggests that no significant difference in exposure to toxic or carcinogenic substances that could have affected the thyroid occurred during deployments. The high prevalence of thyroid cancer in carabineers may merely reflect an increase of this cancer in the general population, or it may suggest the presence of some carcinogenic event in this specific cohort.

Foot bone mass and analysis of calcium metabolism in diabetic patients affected by severe neuropathy

AIM

Charcot neuro osteoarthropathy (NAC) is a devastating foot complication which is associated to peripheral neuropathy. The aim of this study was to investigate the changes in foot bone mass in patients with peripheral neuropathy and to correlate this with calcium metabolism in diabetes.

METHODS

The study included three groups of patients enrolled consecutively: group 1 consisted of 28 diabetic patients, affected by both peripheral neuropathy and autonomic neuropathy as well as monolateral foot ulcer; group 2 consisted of 10 diabetic patients without neuropathy and without foot ulcerations; group 3 consisted of 10 healthy people. In all patients we studied calcium and bone metabolism and quantitative ultrasonography (QUS) of calcaneal bone was performed in both feet in each subject. Calcium and bone metabolism were assessed by the assay of serum parathyroid hormone (PTH), serum calcium, serum phosphorus, serum magnesium, serum bone alkaline phosphatase isoenzyme and urinary excretion of deoxypyridinoline DPD.

RESULTS

In patients with neuropathic ulceration, QUS showed a decrease in bone density in the affected foot: mean T score in the normal foot was -0.54+/-0,26 (mean+/-ESM) while mean T score in the foot with the ulcer was -1.23+/-0.31 (mean+/-ESM) (P=0.004). In diabetic patients without neuropathy the authors did not find any difference in T score between the two feet. Moreover, the T score in the feet in these patients didn't show any differences in comparison to the T score of the healthy foot in neuropathic patients. The T-score in the feet of normal subjects didn't show any difference in respect to the healthy feet in diabetic patients. No difference of serum parameters of calcium metabolism was seen among the groups, while, among the parameters of bone metabolism, B-ALP was elevated in patients with foot ulcer.

CONCLUSION

These data suggest that bone demineralization is associated to peripheral neuropathy with foot ulceration. MOC can represent a way to personalized therapy of patients who are prone to fractures and to the development of NAC.

Association of functional gene variants in the regulatory regions of COX-2 gene (PTGS2) with nonmelanoma skin cancer after organ transplantation

BACKGROUND

Overexpression of cyclooxygenase-2 (COX-2), resulting in excessive prostaglandin production, has been observed in human epidermal keratinocytes after ultraviolet B injury, in squamous cell skin carcinoma (SCC), in actinic keratoses, and in the early stages of carcinogenesis in a wide variety of tissues. The dysregulation of COX-2 expression can in part be due to functional changes affecting regulatory elements in the promoter or 3' untranslated region (UTR) of the gene. Two common polymorphisms (-765G-->C, and -1195A-->G) in the promoter region of the COX-2 gene (now PTGS2), and one common polymorphism in the 3' UTR (8473T-->C) have been described, and reported as associated with various malignancies.

OBJECTIVES

To determine if common known polymorphisms in the regulatory region of the COX-2 gene (PTGS2) can be associated with nonmelanoma skin cancer (NMSC) predisposition after organ transplantation, to evaluate if cancer risks are associated with specific COX-2 gene (PTGS2) haplotypes containing these polymorphisms, and to identify possible new genetic polymorphisms in the proximal 5' or 3' regulatory regions of the gene associated with disease.

METHODS

The frequency of the three polymorphisms was determined in 240 Northern Italian transplant recipient patients (107 cases and 133 controls) with polymerase chain reaction-restriction fragment length polymorphism analysis. The proximal 5' and 3' regulatory regions of the gene were screened by heteroduplex analysis.

RESULTS

Stratification by age at transplant and type of tumours [SCC or basal cell carcinoma (BCC)] demonstrated that allele -765C represented a protective factor in BCC cases undergoing transplantation before 50 years of age (CC + CG vs. GG, Fisher exact test P = 0.003). One rare polymorphism, -62C-->G, was detected in the 5' flanking region. The allele frequency of -62G was 0.019, and no difference in genotype between cases and controls was observed. No other variants were found, suggesting that sequence variations in these regions are not likely to contribute to NMSC risk in this population. Haplotype analysis showed that the haplotype containing all major alleles represents a protective factor in patients with SCC undergoing transplantation after 50 years of age [P = 0.009; OR = 0.37 (0.18-0.79)] and that variant -1195A-->G may represent a risk factor in this subgroup of patients [P = 0.01; OR = 4.77 (1.47-16.41)]. Haplotype analysis in patients with BCC revealed that variant -765C might be a protective factor in patients undergoing transplantation before 50 years of age. Variant 8473T-->C, located in the 3' UTR region of the gene, showed no association with NMSC risk after transplantation.

CONCLUSIONS

COX-2 common variants -765G-->C and -1195A-->G appear to be associated with risk of NMSC, although in different ways in the SCC and BCC subgroups, indicating that environmental and genetic risk factors may play different roles in the outcome leading to these two phenotypes.

Recombinant human thyroid-stimulating hormone is effective for radioiodine ablation of post-surgical thyroid remnants

OBJECTIVE

To investigate whether recombinant human thyroid-stimulating factor (rhTSH) is effective for the radiometabolic ablation of post-surgery thyroid remnants, using low doses of (131)I.

PATIENTS AND METHODS

The study included two groups of patients enrolled consecutively: group 1 consisted of 52 patients with papillary cancer or minimally invasive follicular cancer (stage I and II), and group 2 consisted of 41 patients with the same stage of disease. All patients underwent a total thyroidectomy. Group 1 received 1.11 GBq (30 mCi) (131)I for post-surgical remnants ablation with the aid of rhTSH, while group 2, in the hypothyroid state, received the same amount of radioiodine. To minimize iodine interference, all patients remained on a low iodine diet for 2 weeks and L-thyroxine (L-T4) was stopped for 4 days in the group of patients treated with the aid of rhTSH. To investigate (131)I uptake in this group, a tracer dose was administered 3 h after the second injection of rhTSH and the uptake was evaluated at 24 h just before administration of the therapeutic dose. I was also measured in the patients treated in the hypothyroid state just before the therapeutic dose was given.

RESULTS

After 1 year both groups were studied by using whole-body scintigraphy (WBS) and measuring thyroglobulin after rhTSH. In group 1, WBS was negative in 76.9% (40 patients), while thyroglobulin-stimulated levels were <1.0 ng . ml(-1) in 86.5% (45 patients). In Group 2, WBS was negative in 75.6% (31 patients), while thyroglobulin-stimulated levels were <1 ng . ml(-1) in 78.0% (32 patients). (131)I uptake was 2.29+/-0.45 in the group treated with the aid of rhTSH, and 3.30+/-0.7 in the group treated in the hypothyroid state (P=0.2). No patients treated with the aid of rhTSH and with the short stoppage of L-T4 experienced symptoms of hypothyroidism, and free thyroxine (FT4) and thyroid-stimulating hormone levels remained normal.

CONCLUSIONS

Our data confirm that, when the interference of iodine is minimized, rhTSH is highly effective for the treatment of post-surgical thyroid remnants using a low dose of (131)I.

Survival of male patients with incontinentia pigmenti carrying a lethal mutation can be explained by somatic mosaicism or Klinefelter syndrome

Incontinentia pigmenti (IP), or "Bloch-Sulzberger syndrome," is an X-linked dominant disorder characterized by abnormalities of skin, teeth, hair, and eyes; skewed X-inactivation; and recurrent miscarriages of male fetuses. IP results from mutations in the gene for NF-kappaB essential modulator (NEMO), with deletion of exons 4-10 of NEMO accounting for >80% of new mutations. Male fetuses inheriting this mutation and other "null" mutations of NEMO usually die in utero. Less deleterious mutations can result in survival of males subjects, but with ectodermal dysplasia and immunodeficiency. Male patients with skin, dental, and ocular abnormalities typical of those seen in female patients with IP (without immunodeficiency) are rare. We investigated four male patients with clinical hallmarks of IP. All four were found to carry the deletion normally associated with male lethality in utero. Survival in one patient is explained by a 47,XXY karyotype and skewed X inactivation. Three other patients possess a normal 46,XY karyotype. We demonstrate that these patients have both wild-type and deleted copies of the NEMO gene and are therefore mosaic for the common mutation. Therefore, the repeat-mediated rearrangement leading to the common deletion does not require meiotic division. Hypomorphic alleles, a 47,XXY karyotype, and somatic mosaicism therefore represent three mechanisms for survival of males carrying a NEMO mutation.

Effect of treatment with acarbose and insulin in patients with non-insulin-dependent diabetes mellitus associated with non-alcoholic liver cirrhosis

AIM

Non-insulin-dependent diabetes mellitus (type 2 diabetes) not responding to dietary treatment alone in patients with non-alcoholic liver cirrhosis is characterized by high postprandial hyperglycaemia. The control of postprandial hyperglycaemia in such patients, is generally achieved by the means of progressively higher doses of insulin, with an increasing risk of hypoglycaemia in the late postprandial period. The aim of this study was to evaluate the use of acarbose for the control of postprandial hyperglycaemia in 100 patients with well-compensated liver cirrhosis and type 2 diabetes treated with insulin.

METHODS

The study was double blind with randomization of treatments into acarbose (52 patients) vs. placebo (48 patients) with parallel branches over a period of 28 weeks.

RESULTS

All patients tolerated the treatments well and no significant variations in liver function tests were observed (< 5% vs. pretreatment). A significant reduction of several parameters was observed only after acarbose treatment: fasting glycaemia (173 +/- 28 vs. 146 +/- 19 mg/dl; p < 0.01), postprandial glycaemia (230 +/- 24 vs. 148 +/- 20 mg/dl; p < 0.01), mean glycaemia (206 +/- 20 vs. 136 +/- 13 mg/dl; p < 0.01), mean variation (180 +/- 14 vs. 51 +/- 10 mg/dl; p < 0.01), HbA1c (8.9 +/- 0.8 vs. 7.2 +/- 0.5; p < 0.05), C-peptide 2 h after a standard meal (4.5 +/- 1.9 vs. 2.8 +/- 1.7 ng/ml; p < 0.05), whereas the parameters did not change significantly after the placebo. After acarbose treatment a significant increase of intestinal voiding/week (+116% vs. +10%; p < 0.01) and a parallel reduction of blood ammonia levels (-52 +/- 9% vs. -9 +/- 5%; P < 0.01) were observed.

CONCLUSIONS

The results clearly document the good tolerability and the absence of toxic effects of acarbose on liver, due to the lack of both intestinal absorption and hepatic metabolism of the drug at doses in the therapeutic range. In fact, acarbose increases the peristalsis movements of the gut, stimulates the proliferation of the saccarolytic bacteria and simultaneously reduces the proliferation of proteolytic bacteria, thus resulting active in the reduction of blood ammonia levels. These effects of acarbose may be advantageously exploited in the treatment of type 2 diabetic patients with well-compensated non-alcholic liver cirrhosis.

Increased TGFbeta type II receptor expression suppresses the malignant phenotype and induces differentiation of human neuroblastoma cells

TGFbeta can modulate neuroblastoma (NB) cell proliferation and differentiation in vitro. In this study we used a NB cell line (LAN-5) which has been shown to partially respond to TGFbeta and to present high levels of TGFbeta receptor type I and low levels of receptor type II (TbetaRII) on the cell surface. To evaluate the role of TbetaRII in mediating TGFbeta effects, LAN-5 cells were transfected with an expression vector containing the human full-length TbetaRII cDNA or with the empty vector pcDNA3. Compared to control CLV3 cells (transfected with empty plasmid) and parental LAN-5 cells, isolated neomycin-resistant clones (CL1 and CL3) expressed higher levels of TbetaRII, had reduced cell growth rate in vitro, and were unable to form tumors in vivo. Furthermore, isolated clones modified their morphology, assuming a terminally differentiated neuronal phenotype. Immunocytochemical staining demonstrated a basal increased expression of neural-specific markers, such as axonal growth-associated protein (GAP43) and neurofilaments (NF200). TGFbeta treatment further increased the synthesis of NF200 and GAP43 in the transfected clones as revealed by Western blot analysis. These data indicate that TbetaRII overexpression potentiates the TGFbeta signal transduction pathway, reverting NB cell neoplastic phenotype with the reduction of proliferation rate and the induction of terminal maturation.

Overexpression of transforming growth factor beta-type II receptor reduces tumorigenicity and metastastic potential of K-ras-transformed thyroid cells

Expression of type II receptor of transforming growth factor beta (TbetaRII) is necessary for this factor to inhibit the growth of thyroid epithelial cells. In rat thyroid transformed cells, the resistance to transforming growth factor beta (TGFbeta) is associated with a decreased expression of TbetaRII mRNA and protein. Reduced TbetaRII expression has also been found in human thyroid differentiated and undifferentiated carcinomas. To investigate the role of TbetaRII in modulating the tumorigenic potential of k-ras-transformed thyroid cells, we transfected these cells with an expression vector carrying the human TbetaRII gene, regulated by an inducible promoter. Isolated clones, overexpressing TbetaRII, showed a reduction in the anchorage-dependent and -independent cell growth, compared with control k-ras-transformed cells. When transplanted in athymic nude mice, the transfected clones presented a decrease in tumorigenicity with respect to the highly malignant parental cells. Moreover, the diminished tumorigenic ability of the clones studied was accompanied by a statistically significant reduction in spontaneous and lung artificial metastases. Taken together, our data demonstrate that TbetaRII acts as a potent tumor suppressor gene when overexpressed in malignant thyroid cells.

Transforming growth factor-beta1 enhances the invasiveness of human MDA-MB-231 breast cancer cells by up-regulating urokinase activity

Transforming growth factor-beta (TGFbeta1) enhances human MDA-MB-231 breast tumour cell invasion of reconstituted basement membrane in vitro but does not inhibit proliferation of this cell line. In contrast to basal invasion, which is plasmin-, urokinase (uPA)-, tissue-type plasminogen activator (t-PA)-, matrix metalloproteinase (MMP)-9- and TIMP-1-inhibitable MMP-dependent, TGFbeta1 enhanced-invasion is dependent upon plasmin and uPA activity but does not appear to involve t-PA-, MMP9- or TIMP-1-inhibitable MMPs, as judged by inhibitor studies. Enhanced invasion is associated with increased u-PA, UPAR, PAI-1, MT-MMP-1, MMP-9 and TIMP-1 expression; with reduced t-PA, MMP-1 and MMP-3 expression; and with the induction of membrane MMP-9 association. The net result of these changes includes increased secreted, but not membrane-associated, uPA levels and activity and reduced secreted levels of plasmin and APMA-activatable gelatinolytic, collagenolytic and caseinolytic MMP activity but no change in membrane-associated gelatinolytic activity, despite increased MT-MMP-1 expression and MMP-9 membrane association. TGFbeta1 does not induce MMP-2 expression. Our data indicate that TGFbeta1 can promote the malignant behaviour of MDA-MB-231 cells refractory to TGFbeta1-mediated proliferation control by enhancing their invasive capacity. We suggest that this results from the action of a uPA/plasmin-dependent mechanism resulting from stimulation of uPA expression, secretion and subsequent activity, despite elevated PAI-1 inhibitor levels.

Transforming growth factor-beta1 enhances the invasiveness of human MDA-MB-231 breast cancer cells by up-regulating urokinase activity

Transforming growth factor-beta (TGFbeta1) enhances human MDA-MB-231 breast tumour cell invasion of reconstituted basement membrane in vitro but does not inhibit proliferation of this cell line. In contrast to basal invasion, which is plasmin-, urokinase (uPA)-, tissue-type plasminogen activator (t-PA)-, matrix metalloproteinase (MMP)-9- and TIMP-1-inhibitable MMP-dependent, TGFbeta1 enhanced-invasion is dependent upon plasmin and uPA activity but does not appear to involve t-PA-, MMP9- or TIMP-1-inhibitable MMPs, as judged by inhibitor studies. Enhanced invasion is associated with increased u-PA, UPAR, PAI-1, MT-MMP-1, MMP-9 and TIMP-1 expression; with reduced t-PA, MMP-1 and MMP-3 expression; and with the induction of membrane MMP-9 association. The net result of these changes includes increased secreted, but not membrane-associated, uPA levels and activity and reduced secreted levels of plasmin and APMA-activatable gelatinolytic, collagenolytic and caseinolytic MMP activity but no change in membrane-associated gelatinolytic activity, despite increased MT-MMP-1 expression and MMP-9 membrane association. TGFbeta1 does not induce MMP-2 expression. Our data indicate that TGFbeta1 can promote the malignant behaviour of MDA-MB-231 cells refractory to TGFbeta1-mediated proliferation control by enhancing their invasive capacity. We suggest that this results from the action of a uPA/plasmin-dependent mechanism resulting from stimulation of uPA expression, secretion and subsequent activity, despite elevated PAI-1 inhibitor levels.

Oncogenes and antioncogenes involved in human thyroid carcinogenesis

The development of cancer is due to the accumulation of multiple somatic mutations, in some cases following germline mutations, which occur in hereditary malignancies such as retinoblastomas or multiple endocrine neoplasia (MEN 2A and B). Genetic alterations or changes in the expression of growth regulatory genes can lead to the initiation of malignant transformation and to eventual tumor progression. Cells that have undergone these cumulative alterations in either the structure or expression of these regulatory genes generally possess a selective growth and/or metastatic advantage over other normal non-transformed cells. Thus, activation of dominantly transforming oncogenes by point mutations, gene amplification, chromosomal translocation or insertional mutagenesis can lead to uncontrolled cellular growth or to a disruption in normal differentiation or apoptosis. Equally contributory to the process of malignant progression is the inactivation of recessive tumor suppressor genes due to point mutations and/or loss of heterozygosity in one allele, which can ultimately lead to a reduction of homozygosity in both alleles. Thyroid tumors in humans represent a particularly suitable multistage model of epithelial tumorigenesis. In fact, even though most thyroid neoplasms originate from a single cell type, i.e. the thyroid follicular cell, they include a broad spectrum of tumors with different phenotypic characteristics and variable biological and clinical behaviour. Multiple degrees of malignancies have been defined: from the benign colloid adenomas through the slowly progressive differentiated papillary and follicular carcinomas to the invariably fatal anaplastic carcinomas, although these histological changes are not necessarily sequential. In this review an effort has been made to summarize and integrate new data published on genetic lesions and altered expression of genes involved in the tumorigenesis of the follicular type of thyroid cancer. We have focused our interest only on gene alterations inducing gain or loss of function, that have been studied in vivo in human thyroid tumor specimens by the use of different techniques, such as PCR mediated DNA analyses, sequencing, mRNA level evaluation and protein expression by immunohistochemical staining.

Restored expression of transforming growth factor beta type II receptor in k-ras-transformed thyroid cells, TGF beta-resistant, reverts their malignant phenotype

Transforming growth factor beta 1 (TGF beta 1) inhibits the growth of normal rat epithelial thyroid cells (FRTL-5 strain) by counteracting thyrotropin (TSH)-stimulated DNA synthesis and by slowing the cells in the G1 phase of the cell cycle. Here, we have studied two clones of FRTL-5 thyroid cell line transformed by the wild type (wt) v-k-ras oncogene (K.M.A1, K.M.A2) and one clone (A6) transformed by a temperature-sensitive (ts) v-k-ras mutant. Anchorage-dependent as well as anchorage-independent growth of these k-ras-transformed cells was not inhibited by TGF beta 1. TGF beta 1 resistance appeared to be dependent by a functional p21 k-ras, because A6 cell growth was partially inhibited at the nonpermissive temperature (39 degrees C). To determine the basis for TGF beta 1 resistance in k-ras-transformed thyroid cells, we looked for possible defects in the expression of type I (T beta R-I/ALK5) and type II TGF beta receptors (T beta R-II). Lower levels of type II receptors were present in all of the k-ras-transformed clones, as revealed by both Northern blot and cross-linking experiments. A partial reversion of the malignant phenotype of the wt k-ras-transformed clone was obtained in two clones isolated after transfection of the malignant thyroid cells (K.M.A1) with a T beta R-II expression vector. These two clones also showed restored levels of exogenous T beta R-II mRNA and protein, and both clones showed a partially reacquired sensitivity to TGF beta 1. Similarly, the reversion of the malignant phenotype of the A6 clone grown at the nonpermissive temperature was accompanied by a restored expression of the T beta R-II receptors. These data indicate that active k-ras oncogene can induce TGF beta 1 resistance in rat thyroid cells and suggest that one of the possible mechanisms of escape from TGF beta 1 growth control in k-ras-induced thyroid carcinogenesis involves a reduced expression of T beta R-II receptors.

X-linked Alport syndrome: an SSCP-based mutation survey over all 51 exons of the COL4A5 gene

The COL4A5 gene encodes the alpha5 (type IV) collagen chain and is defective in X-linked Alport syndrome (AS). Here, we report the first systematic analysis of all 51 exons of COL4A5 gene in a series of 201 Italian AS patients. We have previously reported nine major rearrangements, as well as 18 small mutations identified in the same patient series by SSCP analysis of several exons. After systematic analysis of all 51 exons of COL4A5, we have now identified 30 different mutations: 10 glycine substitutions in the triple helical domain of the protein, 9 frameshift mutations, 4 in-frame deletions, 1 start codon, 1 nonsense, and 5 splice-site mutations. These mutations were either unique or found in two unrelated families, thus excluding the presence of a common mutation in the coding part of the gene. Overall, mutations were detected in only 45% of individuals with a certain or likely diagnosis of X-linked AS. This finding suggests that mutations in noncoding segments of COL4A5 account for a high number of X-linked AS cases. An alternative hypothesis is the presence of locus heterogeneity, even within the X-linked form of the disease. A genotype/phenotype comparison enabled us to better substantiate a significant correlation between the degree of predicted disruption of the alpha5 chain and the severity of phenotype in affected male individuals. Our study has significant implications in the diagnosis and follow-up of AS patients.

Prenatal diagnosis of autosomal dominant polycystic kidney disease using flanking DNA markers and the polymerase chain reaction

A prenatal diagnosis was carried out on a 9-week-old fetus at risk for autosomal dominant polycystic kidney disease (ADPKD). Ten members of the family were previously typed using five DNA markers linked to the PKD1 locus on chromosome 16, and one marker linked to the putative PKD2 locus on chromosome 2. The polymerase chain reaction (PCR) was used to amplify the D16S125 locus. Pairwise and multipoint lod scores indicated that the family was most likely segregating a PKD1 mutation. The fetus inherited the disease haplotype from the affected parent. Diagnostic accuracy was greater than 99 per cent, taking into account the possibility of genetic heterogeneity.

Linkage analysis for the diagnosis of autosomal dominant polycystic kidney disease, and for the determination of genetic heterogeneity in Italian families

Sixty-eight individuals from six Italian families in which autosomal dominant polycystic kidney disease (ADPKD) is segregating, were typed in DNA polymorphisms linked to the PKD1 locus on chromosome 16. A total of ten probes were used: 3' HVR, HMJ1, EKMDA, GGG1, 26-6, VK5B, 218EP6, 24.1, CRI090, and 41.1. Zmax was 4.502 at theta = 0.082 between ADPKD and 3'HVR, and 4.382, 1.947, and 1.576 between ADPKD and GGG1, 26.6, and 218EP6, respectively, at theta = 0.0. No clear evidence of genetic heterogeneity was found. Multipoint analyses were consistent with linkage to PKD1. Twenty-nine diagnoses and 16 exclusions made by ultrasonography were confirmed by genotype determinations; in two clinically uncertain cases, DNA analysis predicted one individual as being affected and the other unaffected.

Evidence against the reported linkage of the cutaneous melanoma-dysplastic nevus syndrome locus to chromosome Ip36

The reported linkage between cutaneous melanoma and the dysplastic nevus syndrome (CM/DNS) to markers located on the distal portion of the short arm of chromosome 1 was examined in three Utah kindreds ascertained for multiple cases of melanoma. Family members in these kindreds were genotyped for the two markers reported to be most closely linked in the Bale study, PND and D1S47. Both melanoma alone and a combined melanoma/DNS phenotype were analyzed; no evidence for linkage was found. By multipoint linkage analysis the CM/DNS locus was excluded from an area of 55 cM containing the PND-D1S47 region. Diagnostic or genetic heterogeneity are alternate explanations for the discrepancy between our observations and those of Bale et al.