P291 SUBVALVULAR MITRAL APPARATUS REMODELING DURING HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY SURGERY: A 15–YEARS OF EXPERIENCE

Background and Aims

To assess the role of the mitral valve apparatus (leaflets, chordae and papillary muscles (PM) in left ventricle outflow tract (LVOT) obstruction, and results of the surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM) in a retrospective observational study.

Methods

Seventy consecutive patients (58±12 years, M/F ratio: 41/29) undergoing HOCM surgery from 2007 to 2021 at our institute were reviewed. End points included the involvement of the mitral valve in LVOT obstruction, mortality, and change in clinical and echocardiographic characteristics after HOCM surgery.

Results

Secondary chordae tendineae tractioning the anterior mitral leaflet to the interventricular septum were detected in the majority of the patients. Anomalous, hypertrophied, and fused PM with muscularis trabeculae hypertrophy were a common findings. Four patients had posterior leaflet redundancy. Secondary chordae (90%), PM and muscularis trabeculae resection and PM splitting and elongation (77%) were added variably to septal myectomy (100%). Nine procedures (6%) on mitral valve leaflets were performed, involving 6 posterior and 3 anterior mitral leaflets. Long–term follow up was 4.6±3.7 years. There was no hospital mortality, and NYHA was reduced from 3±0.6 to 1±0.7 (p < 0.0001), the LVOT gradient from 91±35 to 21±17 mmHg (p < 0.0001), mitral valve regurgitation from grade 3±1 to 1±0.6 (p < 0.0001), and septum thickness from 19±3 to 14±2 mm (p < 0.0001).

Conclusions

The mitral valve apparatus with all its components contribute variably to LVOT dynamic obstruction thus, surgical correction in addition to extended myectomy is recommended to achieve the best outcome.

Novel achromatic single reflection quarter-wave retarder: design and measurement

In this work, we present an achromatic quarter-wave retarder whose design is based upon the reflection properties of an isotropic-anisotropic interface. In theory, it is possible to obtain a π/2 phase shift by means of a total internal reflection at an isotropic-isotropic interface. However, in order to achieve such a phase shift, it is necessary to use a medium with a particularly high refractive index. We have previously shown that these phase shifts can be achieved by means of a total internal reflection in an isotropic-uniaxial interface, which allows the use of smaller refractive index media. By means of this property, we designed, built, and characterized a novel quarter-wave retarder that makes it possible to obtain circularly polarized light from a linear polarization state. We developed some guidelines that allowed us to obtain a device of competitive performance, low cost, and manageable manufacture.

Potential clinical role of telomere length in human glioblastoma

Glioblastoma Multiforme (GBM) is the most common and lethal of human primary central nervous system (CNS) tumors. Due to the tumour's intrinsic clinical and molecular heterogeneity, choice of initial treatment, prediction of survival, stratification of patients, prediction and monitoring of response to therapy, represent some of the greatest challenges in the management of GBM patients. Patients, despite optimal surgery, radiation and chemotherapy, still have a median survival of 14-16 months. A reason for this dismal prognosis is because of the relative inaccuracy of current prognostic markers, so far based on clinical or pathological variables. Molecular markers that effectively predict response to therapy and survival outcomes are limited. Consequently, there is a strong need to develop novel and independent markers of prognosis. Ideal biomarkers for solid tumors would serve one or more important functions. Telomeres, guanine-rich tandem DNA repeats of the chromosomal end, provide chromosomal stability, regulates important cellular processes, and seem to be implicated in human carcinogenesis. Recently, telomeres have been shown either to be associated with clinical markers of disease progression or to be independent markers of cancer prognosis in solid tumours, including GBM. Nevertheless, a corresponding comprehensive discussion of these promising developments in brain tumours has not yet been available in the literature. Therefore, here we reviewed studies focused on the assessment of telomeric length in brain tumours with the aim to emphasized those findings indicating a potential clinical role of telomeres in GBM. With the aim to enhance the awareness of the potential clinical role of telomeres' length information in GBM, using a southern blot analysis, telomeric length in excised tumour samples was analyzed. Moreover, an attempt to correlated telomere length with patients' overall survival, was also performed. The findings here reviewed shows some contradictory results, due to different tissues used as controls, but mainly to cellular and molecular heterogeneity in GBMs that drive molecular mechanisms controlling telomere length, included telomerase and Alternative Lengthening of Telomeres (ALT), through multiple mechanisms. However, overall these studies, including our own, are consistent with the hypothesis that GBMs' telomeres were always shorter when compared with Normal Brain Tissue (NBT), and together with higher telomerase activity seem to be associated with malignancy and poor outcome; while tumours with ALT phenotype have longer telomeres, "less malignant" behaviour and better prognosis. We conclude that, although not entirely consistent in the type of telomere alteration, i.e., attrition vs. elongation, and unclear on the underlying mechanisms, multiple studies in brain tumours have shown that telomere dysfunctions are associated with parameters of clinical outcome in patients with GBMs and therefore will be part of novel risk assessment and prognostic modalities for patients with these still dismal disease.

Incidence of neoplastic disease following lung transplantation: a 17-year single-center experience

OBJECTIVE

Chronic immunosuppressive therapy following solid organ transplantation has been correlated with an increased risk of posttransplantation neoplastic disease (PTND). In this study we evaluated PTND incidence and outcome at our institution over a 17-year period among patients receiving lung transplantation.

MATERIALS AND METHODS

Between February 1992 and December 2008, we performed 290 lung transplantations in 280 patients, including 139 single (48% with 5 retransplantations), and 151 double lung transplantations (52% with 5 retransplantations). Among the 280 patients, 2 had undergone previous double lung transplantation in other hospitals. Follow-up of transplant recipients was performed up to December 2009.

RESULTS

Forty-two patients died in the hospital, producing a cumulative early (30-day) mortality rate of 15%. Among the 238 patients discharged from the hospital who entered our follow-up program, 36 (15%) experienced PTND. The mean time between transplantation and diagnosis was 47 ± 42 months, and patients' mean age at time of diagnosis was 55 ± 14 years. Overall freedom from PTND was 97%, 84%, and 73% at 1, 5, and 10 years, respectively. PTND was considered to be the direct cause of death in 11 patients (30%). Overall survival of patients with PTND at five years (45%) did not differ from the remainder of the transplanted population (46%). However, PTND became a relevant cause of death in the long-term (>5 years) follow-up.

CONCLUSION

Our experience confirms that PTND was frequently diagnosed following lung transplantation. Even if PTND did not seem to significantly affect the survival of patients undergoing lung transplantation, it may become a significant cause of death among those surviving beyond 5 years.

TT virus has a ubiquitous diffusion in human body tissues: analyses of paired serum and tissue samples

The tissue tropism and possible correlation with liver disease of the TT virus (TTV) as well as its prevalence and genotype distribution remain undefined. TTV-DNA was investigated in paired sera and tissue samples from 144 patients, and sera and cerebrospinal fluids (CSF) from additional six subjects. Of the 144 tissue samples, 128 were liver biopsy specimens from subjects with hepatic disease while 16 were surgically obtained nonliver specimens from patients with extrahepatic disease. TTV cloning, sequencing and genotype analyses were performed on isolates from sera, tissue specimens and peripheral blood mononuclear cells of two patients with hepatic and four patients with extrahepatic pathologies, as well as from sera and CSFs of two subjects. TTV was found in 100% of the examined tissues and in 60.1 and 50% of sera from patients with hepatic and extrahepatic pathologies, respectively. Moreover, TTV was detected in four of the six CSFs analysed but only in two correspondent sera. Genotyping revealed the coexistence of multiple TTV genotypes and genetic variants in each infected individual, and the analysis of TTV mRNA showed the presence of transcripts in all the six different tissues studied. These results indicate that the entire adult population in our area is more likely infected by TTV, although several subjects are not viraemic and that TTV infects many different human tissues and is able to invade the central nervous system.

Is investigation of hepatitis C virus NS5A gene heterogeneity a tool for predicting long-lasting response to interferon therapy in patients with HCV-1b chronic hepatitis?

Nonstructural protein 5A (NS5A) of the hepatitis C virus (HCV) may repress the interferon (IFN)-induced protein kinase R (PKR). High variability of different regions in the carboxy-terminal half of NS5A implicated in the interaction with PKR (particularly the interferon sensitivity determining region (ISDR)) may be a predictor of response to IFN in patients infected with genotype 1b of HCV. We examined pretreatment serum samples from 17 HCV-1b infected patients included in the same schedule of IFN therapy. Seven patients were a rare series of sustained responders (SR) with a post-treatment follow-up of 5-7 years, while ten were nonresponders (NR). The carboxy-terminal half of the NS5A gene was amplified and directly sequenced in all 17 cases. In addition, the entire NS5A gene and the part of the HCV E2 gene coding for the hypervariable region 1 (HVR1) were amplified, cloned and sequenced in six cases (three NR and three SR). No difference in number and distribution of amino acid mutations was observed between isolates from SR and NR in any portion of the protein, including the ISDR region. Analysis of full length NS5A confirmed no difference between the two groups. The NS5A gene sequence was different among the six cases cloned although it appeared to be conserved in each individual patient independently of the quasispecies complexity evaluated through HVR1 examination. These data indicate that pretreatment analysis of theNS5A genomic variability has no value in predicting long-lasting response to IFN therapy in HCV-1b-infected patients, and that the HCV NS5A gene has high quasispecies homology.

Analysis of haemochromatosis gene mutations in a population from the Mediterranean Basin

BACKGROUND/AIMS

The C282Y mutation in the haemochromatosis gene (HFE) located on chromosome 6 has been identified as the main genetic basis of hereditary haemochromatosis (HH). Two more mutations of that gene, H63D and S65C, appear to be associated with milder forms of HH. A high allele frequency for C282Y and H63D mutations was reported in populations from North Europe, while incomplete information is available for individuals from the Mediterranean Basin where C282Y homozygotes comprise a smaller percentage of HH cases. In this study we investigated the allele frequency of HFE mutations and the association between HFE mutations and cases of HH in a population from the South of Italy (Sicily and Calabria). In addition, we evaluated a possible association between HFE mutations and either chronic liver disease or type II diabetes.

PATIENTS AND METHODS

Three hundred and twenty-seven individuals (654 chromosomes) were tested for C282Y, H63D and S65C mutations of the HFE gene by restriction fragment length polymorphism. Four had HH, 23 had hepatocellular carcinoma, 100 had chronic liver disease, 100 had type II diabetes, and 100 were healthy controls.

RESULTS

Both C282Y and S65C mutations were each detected in one of the 654 chromosomes analysed (allele frequency=0.15%), while H63D change was found in 122 chromosomes (allele frequency=18.6%) and was equally distributed in all the categories examined. One healthy individual had compound heterozygosity for C282Y and H63D mutations. The frequency of C282Y in this Southern Italian sample was the lowest yet reported for a population of European origin. None of the four HH patients was either homozygous or heterozygous for C282Y.

CONCLUSIONS

In Mediterranean populations from Southern Italy the C282Y mutation occurs sporadically and HFE polymorphisms seem to have little diagnostic relevance.