Structural, molecular and functional characterization of the aorta in HCM

Introduction

Changes in the Extracellular Matrix (ECM) in Hypertrophic Cardiomyopathy (HCM) is thought to involve the myocardium as well as extracardiac tissues. The extent and significance of extra-myocardial changes has not been adequately studied.

Purpose

To describe the structural, molecular, and functional changes in the aorta of HOCM patients.

Methods

The structural and molecular changes in the aortic wall were studied in a cohort of 102 consecutive patients with hypertrophic obstructive cardiomyopathy undergoing myectomy. The biopsies were examined histologically, immunohistochemically and by Electron microscopy. The findings were compared to 10 normal controls obtained from the homograft bank of the Harefield hospital, following IRB guidelines. Changes in expression were quantified using morphometry and western blotting. For aortic stiffness, pulse wave velocity [PWV] was measured using Cardiac Magnetic Resonance (CMR), in the 102 HCM patients as well as age-matched 166 normal controls.

Results

Specimens from HCM aortas showed a misalignment in collagen and elastin fibres. There was a significant reduction in smooth muscle cells [SMCs] markers; integrin beta1 and smooth muscle actin, and an increase in an apoptosis marker, Caspase3. In addition, there was a significant decrease in the number of lamellae and an increase in the interlamellar distance in HCM aortas. FBLNs 1, 2 and 5 showed a reduction in expression in tunica intima and tunica media of HCM biopsies. PWV was significantly higher in HCM patients compared to healthy controls with the highest levels in patients with LV fibrosis.

Conclusion

This study illustrates the link between functional abnormalities in the aorta of HCM patients with structural and molecular changes. These findings can have a potential value in risk stratification and identify new therapeutic targets in HCM.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): STDF-EgyptMagdi Yacoub Foundation

Homozygosity predominantly affects hypertrophic cardiomyopathy minor genes in an Egyptian clinical cohort

Background

Consanguinity is prevalent in Egypt (35%) resulting in a high incidence of homozygosity. The influence of homozygosity on the genetics of Hypertrophic Cardiomyopathy (HCM) has not been adequately studied.

Purpose

The purpose of this study is to define the genetic architecture of HCM in Egypt using ethnically-matched case and control cohorts.

Methods

Prospective Egyptian patients (n=514) and controls (n=400) were recruited to Aswan Heart Centre for clinical phenotyping and genetic testing for 174 genes implicated in inherited cardiac conditions (Illumina). Rare variation (gnomAD filtering allele frequency ≤4x10–5) in 13 validated HCM genes were classified according to the American College of Medical Genetics (ACMG) guidelines and compared with a prospective HCM cohort of predominantly European ancestry (n=684).

Results

Significantly fewer rare variants detected in Egyptian patients could be classified as (likely) pathogenic compared to Europeans (40.8% vs. 61.6%, p-value=1.6x10–5). Incorporating analysis from these Egyptian case-control cohorts into the ACMG guidelines increased this yield to 53.8%. Homozygous variants were more frequently observed in Egyptian patients (4.1% vs 0.1%, p-value=2x10–7), with variants in the minor HCM genes MYL2, MYL3 and CSRP3 more likely to present in homozygosity than the major genes (MYH7, MYBPC3 and troponins), suggesting such variants are less penetrant in the heterozygous state.

Conclusions

The integration of Egyptian-specific genetic and phenotypic data significantly improves variant interpretation in HCM and consequently the precision of genetic testing. The observed prevalence of homozygosity and rare variation in minor HCM genes in Egyptian patients provides important insights into its disease-mechanisms and genetics.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Science and Technology Development FundAl Alfi Foundation

High precision machine learning-enabled ECG algorithm for predicting sites of idiopathic ventricular arrhythmia origin

Introduction

Radiofrequency catheter ablation (CA) is an efficient antiarrhythmic treatment with a class I indication for idiopathic ventricular arrhythmia (IVA). The accurate prediction of the origins of IVA can significantly increase the procedure success rate, reduce operation duration and decrease the risk of complications. The present work proposes an ECG analysis algorithm to estimate 21 possible origins of idiopathic ventricular arrhythmia at a clinical-grade level accuracy, which include left coronary cusp (LCC), right coronary cusp (RCC), aortomitral continuity (AMC), summit, LCC-RCC commissure, left His bundle, mitral valve (MV), left septal including left anterior fascicle (LAF), left posterior fascicle (LPF), left anterior papillary muscle (LAPM), left posterior papillary muscle (LPPM), anterior cusp (AC), left cusp (LC), right cusp (RC), RVOT septal, free wall, right His bundle, tricuspid valve (TV), and right anterior papillary muscle (RAPM).

Method

A total of 18,612 ECG recordings extracted from 545 patients who underwent successful CA to treat IVA were proportionally sampled into training, validation and testing cohorts. We designed four classification schemes responding to different hierarchical levels of the possible IVA origins. The first scheme will help the operators to figure out the origin from epicardium of left ventricular summit, right, and left ventricle. The second one can separate origins from left/right outflow tract and left/right non-out flow tract, respectively. The third one is able to predict 18 anatomical locations, and the fourth scheme can distinguish 21 possible sites. For every classification scheme, we compared 98 distinct machine learning models with optimized hyperparameter values obtained through extensive grid search and reported an optimal algorithm with the highest accuracy scores attained on the validation cohorts.

Results

In the first classification scheme used to predict right ventricular endocardium, left ventricular endocardium, and epicardium of left ventricular summit, the model achieved an accuracy of 99.79 (99.41–99.89) and a F1-score of 99.84 (99.6–99.96). For scheme 2, the proposed method reached an accuracy of 99.62 (99.09–99.78) and a F1-score of 99.42 (98.79–99.75). For scheme 3, the model achieved an accuracy of 97.78 (96.76–98.41), a F1-score of 97.74 (94.15–99.73), and an adjusted accuracy of 98.53 (98.33–99.15). For scheme 4 that can distinguish 21 origin sites, the proposed model attained an accuracy of 98.24 (97.36–98.71), a F1-score of 98.56 (97.88–99.12) and an adjusted accuracy of 98.75 (98.35–99.38).

Conclusion

The proposed machine learning model can be immediately and effortlessly deployed to electrophysiology labs allowing cardiologists to predict the exact origins of arrhythmia and provide an optimum treatment plan both before and during the CA procedure. This approach will significantly reduce the CA procedure duration and the risk of complications.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): 2020 Natural Science Foundation of Zhengjiang Province Confusion matrix for classification schemes

CMR derived ventricular arterial coupling in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Introduction

Ventriculoarterial coupling (VAC) is an important surrogate measurement of global cardiovascular efficiency. However, up till recently, this measurement has been rarely used in clinical practice. This could be due to its invasive nature, and the relatively complex methods required for acquisition and interpretation. We here describe a noninvasive method of measuring VA coupling using cardiac magnetic resonance (CMR) in a cohort of hypertrophic cardiomyopathy (HCM).

Methods

 

Cardiac MRI was performed in 61 patients with hypertrophic obstructive cardiomyopathy (HOCM) before and after undergoing extended surgical myectomy. Cardiac MRIs from 15 patients with non-obstructive HCM were also included for comparison. Hypertensive patients were excluded from this study. Vitals signs were recorded during each MRI study. Arterial end-systolic pressure (AESP) was determined non-invasively as previously described (0.9x brachial blood pressure). Left ventricular end-systolic pressure (LVESP) was calculated by adding the echo-derived peak systolic gradient across the left ventricular outflow tract to the arterial end-systolic pressure. Indexed stroke volume (SVI) in the ascending aorta as well as indexed end systolic volume (ESVI) were calculated from CMR. Indexed arterial (Ea) and ventricular (Ev) elastance were calculated as AESP/SVI and LVESP/ESVI. VA coupling was then calculated as Ea/Ev. 

Results

Compared to the baseline measurements, VAC increased significantly post myectomy (mean VAC pre-myectomy and post-myectomy 0.38 vs. versus 0.62 respectively, p= 0.00001). VAC in non-obstructive HCM patients (mean = 0.64) was statistically similar to that in post-myectomy (p = 0.82) and statistically different from pre-myectomy (p = 0.00016). The mean of LVOTO gradients post- and pre-myectomy were significantly different (p = 0.00001). Significant correlation of the delta-VAC with the delta gradient in the LVOTO was found (r= 0.35, p = 0.005). 

Conclusion

Non-invasive assessment of VA coupling using CMR is feasible and could be a useful tool in the evaluation of patients with various cardiovascular disorders. Further studies with larger numbers of patients are required to establish the utility of this method in clinical practice.

Testotoxicosis without Testicular Mass: Revealed by Peripheral Precocious Puberty and Confirmed by Somatic LHCGR Gene Mutation

Purpose: Testotoxicosis is an autosomal dominant form of limited gonadotropin-independent precocious puberty in boys. It is caused by a heterozygous constitutively activating mutation of the LHCGR gene encoding the luteinizing/hormone receptor (LHR). Some twenty mutations of the LHCGR gene have been reported. Most of them are constitutive mutations isolated from blood leukocyte DNA, although others are somatic, found only in testicular tumoural tissue. In all the previously reported cases of these somatic mutations, the tumour, whether a nodular Leydig cell adenoma or hyperplasia, was easily visible on testicular ultrasonography. The aim of this study was to describe an unusual presentation of a patient with the clinical and hormonal characteristics of testotoxicosis but no well-circumscribed lesion at testicular ultrasonography.Materials and Methods: Molecular analysis of the LHCGR gene was performed by direct sequencing of DNA extracted from peripheral leucocytes and testicular biopsy.Results: Molecular analysis didn't find any LHR mutation in blood, whereas it revealed for the first time a somatic D578H mutation in testicular tissue despite no evidence of a nodular aspect at testis ultrasonography.Conclusions: This observation underlines the need to look for a somatic LHCGR gene mutation from the testicular biopsies of all boys with testotoxicosis with no constitutive LHCGR gene mutation identified from blood DNA, even in the absence of circumscribed testicular lesion at ultrasonography. In addition, based on the known link between LHR mutations and testicular tumourigenesis, yearly ultrasound monitoring of the testes should be considered for these patients.

P2789A new technique to restore shape and pattern of flow in hypoplastic aortic arch

Background

There is no agreement about the best method for correcting hypoplastic aortic arch in infancy. Residual abnormalities in shape can cause late complications.

Patients and methods

We have developed and applied a new method of direct anastomosis of the descending to the ascending aorta to allow for restoration of shape, function and growth. 12 infants undergoing this technique at the age of 61±3months (range 6–28 months) underwent repeat CT 4–15 months after operation.

Pre- and post-operative arch width, height and height to width ratio were recorded for all cases. Computerized shape analysis using an in-house tool (developed in MATLAB) was used for processing the 3D segmented shapes of the aortic arch, and assessing changes in the cross-sectional area at different levels. Computational Fluid Dynamics (CFD) was used to simulate aortic flow propagation and pattern after surgery, using patient specific geometry and flow boundary conditions.

Results

The pre- and post-operative cross-sectional area along the centerline of the aorta and arch was almost normalized, Figure 1.

The pattern of flow during the cardiac cycle with a retrograde helix in the aortic arch, similar to normal, was observed in all cases with peak velocities of 1.1±0.2m/s.

Aortic Shape and flow after surgery

Conclusion

We here describe a new technique, which at least in the short term appears to normalize the size, shape and pattern of flow in the arch. Long term studies are required to establish the value of this technique.

P5272Right versus Left Ventricular Remodelling after Surgical myectomy for HOCM

Background

Surgical myectomy for (HOCM) results in complex structural and functional changes. “Remodelling” in different cardiac chambers. To date, changes in the Right versus the left Ventricle have not been studied.

Methods

Fourty five patients (mean age = 32±16, 68% males) who underwent extended septal myectomy for LVOTO and Fourty “normal” controls (mean age = 32±12 years, 52% males) were studied by cardiac magnetic resonance imaging (CMR). The patients were studied pre-operatively and 6–18 months post-operatively (median = 9 months). The images were analysed by both commercial and in-house software.

Results

After myectomy. Follow up CMR showed changes in RV mass (21±5 to 23±7) g/m2, volume (60±15 to 66±12) ml/m2 and shape using 3 different methods. RV deformation parameters showed significant changes with circumferential strain (−8±2 to −14±4), filling (38±16 to 62±19) ml/s/m2 and ejection rate (−44±17 to −75±22). Changes in RV were substantially higher than those observed in the LV (Figure. 1, Table. 1). All patients reported significant symptomatic improvement with 31 (78%) patients in NYHA class I and 9 (22%) in class II at follow up. Significant reduction in peak gradient across the LVOT by 75%.

Table 1. Summary of reported parameters related to RV Shape for pre and post operation HOCM patients and Normal Healthy Volunteers LV RV Pre Post Normal P-value Pre Post Normal P-value EDV ml/m2 75±18 81±14 73±10 0.005 60±15 66±12 71±12 0.002 ESV ml/m2 20±9 24±8 26±6 0.008 16±7 19±9 26±7 0.02 SV ml/m2 56±13 57±10 51±13 0.38 44±11 48±10 49±14 0.009 EF 74±7 70±7 65±5 0.001 74±8 72±7 64±6 0.228 Mass g/m2 74±33 62±29 27±8 0.0456 21±5 23±7 18±5 0.2100 PFR ml/m2 173±48 141±48 141±40 <0.0001 38±16 62±19 55±24 <0.0001 PER ml/m2 −179±35 −172±42 −144±42 0.29 −44±17 −75±22 −57±22 <0.0001 Peak Strain −20±3 −20±3 −20±3 0.49 −8±2 −14±4 −12±3 <0.0001

Conclusion

LV septal myectomy is followed by structural and functional remodelling which is more extensive in the right than the left ventricle. The clinical significance of these findings needs further study.

In vivo percutaneous microwave ablation in kidneys: Correlation with ex vivo data and ablation work

PURPOSE

To compare diameters of in vivo microwave ablation (MWA) performed in swine kidneys with ex vivo diameters, and to correlate with ablation work (AW), a new metric reflecting total energy delivered.

MATERIAL AND METHODS

Eighteen in vivo MWA were performed in 6 swine kidneys successively using one or two antennas (MicroThermX^®). Ablation consisted in delivering power (45-120W) for 5-15minutes. Ex vivo diameters were provided by the vendors and obtained on bovine liver tissue. AW was defined as the sum of (power)*(time)*(number of antennas) for all phases of an ablation (in kJoules). Kidneys were removed laparoscopically immediately after ablation. After sacrifice, ablations zones were evaluated macroscopically, and maximum diameters of the zones were recorded. Wilcoxon sum rank test and Pearson's correlation were used for comparisons.

RESULTS

For a single antenna (n=12), the in vivo diameters ranged from 12 to 35mm, and 15-49mm for 2 antennas (n=6). The in vivo diameters remained shorter than ex vivo diameters by 8.6%±30.1 on 1 antenna and 11.7%±26.5 on 2 antennas (P=0.31 and 0.44, respectively). AW ranged from 13.5 to 108kJ. Diameters increased linearly with AW both with 1 and 2 antennas, but only moderate correlations were observed (r=0.43 [95% confidence interval: -0.19; 0.81], P=0.16; and 0.57 [-0.44; 0.95], P=0.24, respectively).

CONCLUSION

Although diameters after in vivo renal MWA increased linearly with AW, the moderate correlation and wide standard deviations observed may justify a careful imaging monitoring during treatment delivery and settings adaptation, if needed, for optimal ablation.

Tubulocystic renal cell carcinoma: a new radiological entity

Tubulocystic renal cell carcinoma (TC-RCC) is a recently identified renal malignancy. While approximately 100 cases of TC-RCC have been reported in the pathology literature, imaging features have not yet been clearly described. The purpose of this review is to describe the main radiologic features of this rare sub-type of RCC on ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), based jointly on the literature and findings from a multi-institutional retrospective HIPAA-compliant review of pathology and imaging databases. Using a combination of sonographic and CT/MRI features, diagnosis of TC-RCC appeared to be strongly suggested in many cases.

KEY POINTS

• Tubulocystic renal cell carcinoma is a new entity with typical imaging features • Diagnosis of tubulocystic renal cell carcinoma can be suggested preoperatively by imaging • Cystic renal lesions with high echogenicity may correspond to tubulocystic carcinoma.

Multiparametric magnetic resonance imaging for the differentiation of low and high grade clear cell renal carcinoma

PURPOSE

To retrospectively evaluate the ability of magnetic resonance (MR) imaging to differentiate low from high Fuhrman grade renal cell carcinoma (RCC).

MATERIALS AND METHODS

MR images from 80 consecutive pathologically proven RCC (57 clear cell, 16 papillary and 7 chromophobe) were evaluated. Double-echo chemical shift, dynamic contrast-enhanced T1- and T2-weighted images and apparent diffusion coefficient (ADC) maps were reviewed independently. Signal intensity index (SII), tumour-to-spleen SI ratio (TSR), ADC ratio, wash-in (WiI) and wash-out indices (WoI) between different phases were calculated and compared to pathological grade and size. The Fuhrman scoring system was used. Low grade (score ≤ 2) and high grade (score ≥ 3) tumours were compared using univariate and multivariate analyses.

RESULTS

No associations between grade and imaging factors were found for papillary and chromophobe RCCs. For clear cell RCCs, there was a significant association between the grade and parenchymal WiI (WiI2) (P = 0.02) or ADCr (P = 0.03). A significant association between tumour grade and size (P = 0.01), WiI2 (P = 0.02) and ADCr (P = 0.05) remained in multivariate analysis.

CONCLUSIONS

Multiparametric MRI can be used to accurately differentiate low Fuhrman grade clear cell RCC from high grade. High Fuhrman grade (≥ 3) RCCs were larger, had lower parenchymal wash-in indices and lower ADC ratios than low grade.

KEY POINTS

• Fuhrman grade of clear cell RCC can be differentiated with multiparametric MR imaging. • Fuhrman grade significantly differed for size, parenchymal wash-in index and ADC ratio. • No significant associations were found for papillary and chromophobe renal cell carcinoma.

Routinely performed multiparametric magnetic resonance imaging helps to differentiate common subtypes of renal tumours

OBJECTIVES

To retrospectively evaluate the ability of multiparametric magnetic resonance (MR) imaging to differentiate renal tumours.

METHODS

MR images from 100 consecutive pathologically proven solid renal tumours without macroscopic fat [57 clear cell, 16 papillary and 7 chromophobe renal cell carcinomas (RCCs), 16 oncocytomas and 4 minimal fat angiomyolipomas (AMLs)] between 2009 and 2012 were evaluated. Two radiologists blinded to pathology results independently reviewed double-echo chemical shift, dynamic contrast-enhanced T1- and T2-weighted images and apparent diffusion coefficient (ADC) maps. Signal intensity index (SII), tumour-to-spleen SI ratio (TSR), ADC ratio, wash-in (WiI) and wash-out indices (WoI) between different phases were calculated.

RESULTS

There were significant differences between papillary RCCs and other renal tumours for arterial WiI (P < 0.001), initial WoI (P = 0.006) and ADC ratio (P < 0.001); between chromophobe RCCs and oncocytomas for TSR (P = 0.02), parenchymal WiI (P = 0.03), late WiI (P = 0.02), initial WoI (P = 0.03) and late WoI (P = 0.04); and between clear cell RCCs and oncocytomas for SII (P = 0.01) and parenchymal WiI (P = 0.01). Papillary RCCs were distinguished from other tumours (sensitivity 37.5 %, specificity 100 %) and oncocytomas from chromophobe RCCs (sensitivity 25 %, specificity 100 %) and clear cell RCCs (sensitivity 100 %, specificity 94.2 %).

CONCLUSION

MR imaging provides criteria able to accurately distinguish papillary RCCs from other tumours and oncocytomas from chromophobe and clear cell RCCs.

KEY POINTS

• Multiparametric MR parameters accurately distinguish papillary RCCs with high specificity (100 %). • Oncocytomas can be distinguished from chromophobe RCCs with high specificity (100 %). • Oncocytomas can be distinguished from clear cell RCCs with high specificity (94.2 %). • In oncocytomatosis, imaging follow-up with such parameters analysis could be promoted.

A rare case of mantle cell lymphoma as lymphomatous polyposis with widespread involvement of the digestive tract

Lymphomatous polyposis of the gastrointestinal tract is rare. It refers to a heterogeneous group of small B-cell lymphomas including mantle cell lymphoma, follicular lymphoma and MALT lymphoma. It is characterized by the presence of multiple lymphomatous polyps along one or more segments of the digestive tract. Clinical symptoms are non-specific. We herein report the case of a 74-year old man initially admitted for an upper and lower gastrointestinal endoscopy to explore a positive Hemoccult test. The endoscopy revealed multiple polyps all along the gastrointestinal tract. Histopathological study showed a diffuse lymphomatous proliferation of small B-cells whose immunohistochemical features were compatible with a mantle cell lymphoma. Tumoral B-cells showed a positivity of cyclin D1 markers but negativity for CD5. Immunochemotherapy with R-CHOP (rituximab, cyclophosphamide, adriamycine, vincristine and prednisone) was initiated. Based on this case study, the pitfalls of gastrointestinal tract lymphomatous polyposis diagnosis, prognosis and treatment options are discussed.

Late donor cardiectomy after paediatric heterotopic cardiac transplantation

BACKGROUND

Cardiac transplantation is a life-saving procedure in infants and children with advanced cardiomyopathy. However, it is greatly limited by shortage of paediatric donors and the complications of long-term immunosuppression, including post-transplant lymphoproliferative disorder (PTLD). We report the management of an infant who had heterotopic cardiac transplantation for advanced cardiomyopathy with secondary pulmonary hypertension who developed seemingly incurable PTLD.

METHODS

An 8-month-old girl presented in 1994 with signs of severe heart failure, secondary to dilated cardiomyopathy. At age 11 months, the patient underwent a heterotopic cardiac transplantation.

FINDINGS

The patient developed many episodes of PTLD associated with Epstein-Barr virus infection that were resistant to several therapies, including reduction of immunosuppression. Native heart recovery enabled removal of the donor heart 10.5 years after the original operation to allow complete cessation of immunosuppression. Her postoperative course was uncomplicated and the outcome was excellent. 3.5 years after surgery, the patient remains well, in complete remission from her PTLD, and has normal cardiac function.

INTERPRETATION

This case shows several issues relating to the use of heterotopic cardiac transplantation in infants and the capacity of the heart to recover. It also provides new insights into the interaction between the immune system with several aspects of modern management of post-transplantation PTLD.

FUNDING

None.

[Nasofrontal fistula and epidermoid cyst: a case study]

Nasofrontal fistulas, also called nasofrontal dermal sinuses, are very rare and found for the most part in children. This congenital malformation may be revealed by local infection or neuromeningitis, making this a serious disorder. We report one case of nasofrontal dermal sinus diagnosed in an 11-month-old girl, which was complicated by left fronto-orbital infection. Through this case, the authors stress the role of imaging methods in confirming the diagnosis and looking for associated cysts (dermoid and epidermoid).

p53 status correlates with histopathological response in patients with soft tissue sarcomas treated using isolated limb perfusion with TNF-alpha and melphalan

BACKGROUND

Recombinant tumor necrosis factor-alpha (TNF-alpha) combined to melphalan is clinically administered through isolated limb perfusion (ILP) for regionally advanced soft tissue sarcomas of the limbs. In preclinical studies, wild-type p53 gene is involved in the regulation of cytotoxic action of TNF-alpha and loss of p53 function contributes to the resistance of tumour cells to TNF-alpha. The relationship between p53 status and response to TNF-alpha and melphalan in patients undergoing ILP is unknown.

PATIENTS AND METHODS

We studied 110 cases of unresectable limbs sarcomas treated by ILP. Immunohistochemistry was carried out using DO7mAb, which reacts with an antigenic determinant from the N-terminal region of both the wild-type and mutant forms of the p53 protein, and PAb1620mAb, which reacts with the 1620 epitope characteristic of the wild-type native conformation of the p53 protein. The immunohistochemistry data were then correlated with various clinical parameters.

RESULTS

P53DO7 was found expressed at high levels in 28 patients, whereas PAb1620 was negative in 20. The tumours with poor histological response to ILP with TNF-alpha and melphalan showed significantly higher levels of p53-mutated protein.

CONCLUSIONS

Our results might be a clue to a role of p53 protein status in TNF-alpha and melphalan response in clinical use.

Efficacy of adjuvant chemotherapy according to Prion protein expression in patients with estrogen receptor-negative breast cancer

BACKGROUND

Prion protein (PrPc) has been previously reported to be associated with resistance to proapoptotic stimuli. We evaluated whether the expression of PrPc was associated with the resistance to adjuvant chemotherapy in patients with estrogen receptor (ER) -negative breast cancer.

PATIENTS AND METHODS

The expression of PrPc by primary tumors was assessed by immunohistochemistry in a series of 756 patients included in two randomized trials that compared anthracycline-based chemotherapy to no chemotherapy. The PrPc expression was correlated with ER expression and the benefit of adjuvant chemotherapy was assessed according to PrPc expression in patients with ER-negative tumors.

RESULTS

Immunostaining analysis showed that PrPc was mainly expressed by myoepithelial cells in normal breast tissue. Tissue microarray analysis from 756 breast tumors showed that PrPc was associated with ER-negative breast cancer subsets (P < 0.001). Adjuvant chemotherapy was not associated with a significant risk reduction for death in patients with ER-negative/PrPc-positive disease [adjusted hazard ratio (HR) for death = 0.98, 95% confidence interval (CI) 0.45-2.1, P = 0.95], while it decreased the risk for death (HR = 0.39, 95% CI 0.2-0.74, P = 0.004) in patients with ER-negative/PrPc-negative tumors.

CONCLUSION

These data indicate that ER-negative/PrPc-negative phenotype is associated with a high sensitivity to adjuvant chemotherapy.

Mortalité par méningites à pneumocoque chez l'enfant. Facteurs pronostiques à propos d'une série de 73 observations

OBJECTIVE

Despite advances in antibiotic therapy strategies and pediatric intensive care, prognosis of Streptococcus pneumoniae meningitis remains very poor. To determine the factors associated with hospital mortality of children with pneumococcal meningitis.

METHODS

We conducted a retrospective study of 73 cases of childhood pneumococcal meningitis admitted in 4 teaching hospitals in the center of Tunisia during a 8-year period (1995-2002).

RESULTS

Hospital mortality was 13.7% (10 of 71 patients), and neurologic sequela were observed in 34.5% of survivors. Based on univariable analysis, five variables were associated with the outcome: Pediatric Risk of Mortality score (p < 0.001), coma (p=0.0009), use of mechanical ventilation (p=0.0001), convulsions (p = 0.0449), and shock (p=0.0085). In multivariable analysis, only 2 factors were independently associated with in-hospital mortality: Pediatric Risk of Mortality score and the use of mechanical ventilation. 11.8% of pneumococcal isolates were intermediate and resistant to penicillin. Non-susceptible pneumococcus strains to penicillin and the use of steroids were not associated significantly with the mortality rate.

CONCLUSIONS

Pneumococcal meningitis remains a devastating childhood disease. Two variables were independently associated with the in-hospital death in our series (high Pediatric Risk of Mortality score, and the use of mechanical ventilation). According to these data we may recommend the inclusion of vaccination against streptococcus pneumonia in the children's immunization program in Tunisia.

[Cerebral hydatid disease: imaging features]

Cerebral hytatid cysts (HC) are extremely rare, forming 2% of all intra cranial space occupying lesions even in counties where the disease is endemic. HC diagnosis is usually based on a pathognomonic computed tomography (CT) pattern. In order to assess the value of MR we reviewed the CT (n=25) and magnetic resonance (MR, n=4 including diffusion and proton magnetic resonance spectroscopy in 1) imaging of 25 patients with pathologically confirmed cerebral hydatid disease. 19 HC were seen in children under 16 years. All were supra tentorial with 22 in the middle cerebral artery territory. HC was solitary in 18 cases, unilocular in 23 and multi-vesicular in 2 with heavily calcified pericyst in 1. 2 cysts were intra ventricular and 1 intra aqueducal. The most typical features were well defined, smooth thin walled spherical or oval cystic lesions of CSF density and/or signal with considerable mass effect (20/25). Surrounding oedema with complete or incomplete rim enhancement was seen in 3 cases which were labelled as complicated and/or infected cysts. Although CT is diagnostic of hydatid disease in almost all cases (22/25), MRI including diffusion and spectroscopy precisely demonstrate location, number, cyst capsule, type of signal and enhancement and allows diagnosis of atypical or complicated HC and appears more helpful in surgical planning.