Genetics of Dilated Cardiomyopathy: Clinical Implications.

PURPOSE OF REVIEW: This review aims to summarize the current knowledge on the genetic background of dilated cardiomyopathy (DCM), with particular attention to the genotype-phenotype correlations and the possible implications for clinical management. RECENT FINDINGS: Next generation sequencing (NGS) has led to the identification of an increasing number of genes and mutations responsible for DCM. This genetic variability is probably related to the extreme heterogeneity of disease manifestation. Important findings have associated mutations of Lamin A/C (LMNA) and Filamin C (FLNC) to poor prognosis and the propensity to cause an arrhythmic phenotype, respectively. However, a deeper understanding of the genotype-phenotype correlation is necessary, because it could have several implications for the clinical management of the patients. Furthermore, the correct interpretation of pathogenicity of mutations and the clinical impact of genetic testing in DCM patients still represent important fields to be implemented. A pathogenic gene mutation can be identified in almost 40% of DCM patients. The recent discoveries and future research in the field of genotype-phenotype correlation may lead to a more personalized management of the mutation carriers towards the application of precision medicine in DCM.

Correlation between growth inhibition and intranuclear doxorubicin and 4'-deoxy-4'-iododoxorubicin quantitated in living K562 cells by microspectrofluorometry.

Intranuclear drug concentration in cells treated with doxorubicin (DXR) or with 4'-deoxy-4'-iododoxorubicin (IDX) was measured by means of a quantitative microspectrofluorometric technique recently developed by us. Resolution of free and bound drug contributions in fluorescence emission spectra, as collected from a microvolume of single living cell nuclei, provided concentration data with about 10% indetermination. Uptake of DXR and IDX into the nucleus of K562 cells and DXR-resistant K562/DXR cells could then be studied with a sensitive, nondestructive technique. Growth inhibitory concentrations of K562 and K562/DXR cells, when measured with respect to drug content in the medium, differed by a factor of 25 in the case of DXR and by a factor of three in the case of IDX. By contrast, intranuclear drug concentrations measured at corresponding growth inhibitory concentrations are found to be nearly constant, i.e., independent of cellular-resistant phenotype and of anthracycline structure. This result supports an identical mechanism of action for the two drugs, most probably targeted to the nucleus, and ascribes to intracellular transport the different potency of the two drugs in the two cell lines.

Quantitative study of doxorubicin in living cell nuclei by microspectrofluorometry.

Doxorubicin-DNA association has been studied by quantitative microspectrofluorometry. Fluorescence emission spectra from a microvolume of single living cell nuclei treated with doxorubicin have been analyzed in terms of difference in spectral shape and fluorescence yield between free and DNA-bound drug. Contribution of each spectral component to the total signal was calculated by least-squares linear regression. With this method of analysis, total drug concentration has been determined with an error of less than 10%. Moreover, the uptake into the nucleus has been studied in a non destructive way, avoiding use of 14C-labelled drug. Kinetic studies of drug accumulation into the nuclei were conducted on sensitive and resistant cells.

A comparative study of low-density lipoprotein interaction with glycosaminoglycans.

The association between low-density lipoprotein (LDL) and a series of well characterized dermatan and chondroitin sulfates has been investigated by means of the fluorescence anisotropy technique with competition experiments using a fluorescein-labeled high LDL-affinity heparin fraction as a reference. Preparations of glycosaminoglycan (GAG) with sulfation degrees varying over a wide range, as obtained by fractionation or by chemical modification, were chosen for this study. The influence of chain length, which had been found sizeable in a former study of heparin affinity for LDL, was taken into account with an empirical correction of dissociation constants. After this correction, a linear relationship was found between the logarithm of dissociation constants and the number of sulfate groups per disaccharide unit, ns, both for dermatan and chondroitin sulfates, and for heparins. At comparable ns values, however, dermatan sulfates and heparins, which contain L-iduronic acid in their backbone, show higher LDL-affinity than chondroitin sulfates, which contain only D-glucuronic acid. Though confirming a non-specific, predominantly electrostatic interaction between GAGs and LDL, these results indicate modulation of LDL affinity by the polysaccharide backbone.

Vascular homografts for vessel substitution in skeletal and soft tissue sarcomas of the limbs.

Large vessel involvement by skeletal and soft tissue sarcomas of the extremities does not change the modern limb sparing surgery for those neoplasms. An arterial and, if the vein is open, a venous bypass should always be offered to any patient young or old, with high or low grade sarcoma, because preserving the limb permits quicker rehabilitation, which is particularly useful in the case of a short life expectancy. In 650 cases of skeletal sarcomas, 10 arterial (1.5%) and four venous bypasses were done, all with autologous veins but one in PTFE; we had no problems except a silent arterial occlusion. Of 1000 patients with soft tissue sarcomas, 32 (3%) had vessel involvement permitting limb sparing surgery. The arterial bypass, which is the limb-saving operation, was performed 16 times with a PTFE with one early occlusion and four cases of prosthesis infection, with two amputations despite redo operation with an autologous vein. The more recent 16 cases were, therefore, always done with biological vessel substitution--autologous vein or tissue bank vessel--with only one infection that healed without operation and one case of homograft rupture followed by amputation. Since 1999 in all 13 resected cases with an open vein, we did the arterial and the venous bypass (twice PTFE, six autologous vein, and five bank vessel) with the aim of avoiding postoperative venous hypertension, but only four of the venous bypasses remained open. Venous bypasses are a harmless, but still experimental, procedure.

Double excitation of surface modes at uniaxial-metal-isotropic films.

We study the double excitation of surface modes at a metallic film that separates a uniaxial medium from an isotropic dielectric. We find that, for certain constitutive parameters of the structure, two normal modes can be associated to the film. It is found that the distance in the complex plane between the propagation constants of these modes can be considerably reduced by tuning conveniently film parameters, although the propagation constants are "reluctant" to coincide. We also show that a plane wave incident on the film from the crystal side can excite both modes simultaneously, without corrugating the surface or adding another layer. We obtain values of the film width for which the resonances appear at similar angles of incidence and show that these excitations are accompanied by an important increase of the power absorbed by the film and an enhancement of the fields at the two interfaces.

Polymer-bound camptothecin: initial biodistribution and antitumour activity studies.

Camptothecin (CPT) is a potent, antitumour drug acting mainly through inhibition of topoisomerase I during the S-phase of the cell cycle. Despite its impressive antitumour activity, clinical development was halted for unpredictable toxic events. Two soluble N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers were synthesised to contain CPT (5 wt.% and 10 wt.%). CPT was covalently linked at its alpha-hydroxyl group to the polymers through a Gly-Phe-Leu-Gly- spacer. In-vitro, CPT-conjugates were fairly resistant to hydrolysis in plasma as in buffer at neutral pH (0.2-0. 4% free CPT/h), while elastase and cysteine-proteases were able to release the active drug. Plasma levels in mice after intravenous administration of CPT-conjugates confirmed the modest hydrolysis in plasma. Plasma levels were approximately 5-fold lower than those observed at the highest tolerated dose of CPT administered in classical vehicles. Biodistribution in HT29 human colon carcinoma bearing mice was carried out after i.v. injection of [3H]CPT-conjugate and free [3H]CPT. Radioactivity uptake in tumour was evident only after [3H]CPT-conjugate treatment. Repeated intravenous administration of CPT-conjugates to HT29-bearing mice gave more than 90% tumour inhibition, some complete tumour regressions and no toxic deaths. The improved pharmacological profile on HT29 human colon carcinoma xenografts of the first poly(HPMA)-CPT conjugates might be ascribed to their prolonged intra-tumour retention and sustained release of the active drug.

Knee resection arthrodesis with allograft: a long-term follow-up study.

A consecutive series of 57 patients treated by knee resection arthrodesis for malignant or aggressive tumor around the knee was reviewed. Infection was present only after repeated surgery for other complications, delayed union or non-union occurred in 50% of the cases that could be evaluated, but were still easy to manage. Fracture incidence was higher than expected (32.6%) even occurring after 10 years; this was difficult to deal with and it often led to failure. The best possible method of fixation is still being debated, but locked nail and allograft cementation is often advised. Several satisfactory functional results were however achieved when surgery was performed in young patients; final results can be less satisfactory when there is leg length discrepancy and poor acceptance on the part of the patient. In recent years this type of surgery has been limited to younger male patients (10 to 14 years of age) in whom extra-articular knee resection was required or when most of the quadriceps muscle must be removed.

Vertebral hemi-resection for bone tumor with wide invasion of the vertebral canal: modified surgical method.

The authors describe a variation in the method of vertebral hemi-resection used for the treatment of neoplasms that present a wide invasion of the vertebral canal. This is followed by a review of the literature on the subject.

[Mammography and prevention of breast carcinoma. Epidemiological considerations concerning female population of a Rome district]. / Mammografia e prevenzione del carcinoma della mammella. Considerazioni epidemiologiche sulla popolazione femminile di un quartiere di Roma.

At the present time breast cancer represents the primary reason of death caused by cancer amongst the female population of the western countries. Since the actuation of primary prevention programmes results impossible, the aim that must be considered primary is to attain a diagnosis of such tumour as precociously as possible. This research proposes to value the inclination of the female population of a District in Rome, of different classes of age, to have a mammography test in a state of spontaneous screening, in view of a next institution of a structured program of secondary prevention in the area of reference. The results have been examined with relation to the age limits considered as optimum for a correct application of this diagnostic methodology, in line with technical and epidemiological considerations.

[Hypotheses for an organizational model for obligatory reporting of infectious disease]. / Ipotesi di modello organizzativo per la denuncia obbligatoria di malattia infettiva.

The authors, in view of the continuously changing contagious diseases outline, deal with the problem of a better qualification and reorganization of the direct interventions in the contagious diseases prophylaxis. In this respect, the authors deem that the reporting of the cases must assume a primary importance and that all the locally operating health and social services, where the general medicine practitioners have an integrating part, ought to be redefined in their tasks and reorganized in view of the new outlines. So, it is necessary to found a more flexible reporting system. A bidirectional information flux model is also proposed between the public health-services and the general medicine practitioners.

[Prevention of accidents caused by construction work]. / Prevenzione degli infortuni sul lavoro in edilizia.

Descriptive data on occupational accidents and diseases in the field of construction and particularly among builders are reported. They derive from publications of the National Insurance Institute for Occupational Accidents (INAIL) and refer to the Italian and Umbrian situation. Data show that the number and the severity of the accidents in this field are of great concern. The characteristics of the building work in our areas are too peculiar as the work is carried out in small building sites and lasts for a short period of time; subcontracting and piecework are widely diffused; health surveillance is nearly absent. One must take into account all of these characteristics when prevention programs are to be planned. Intervention priority must be given to a) information on occupational risks of contractors and workers; b) first level prevention; c) control and inspection activity. In this respect the A.A. report the results of the watch activity in 703 erecting yards by one to health unit's Department for the health security, safety and welfare of persons at work (period May 1985 - May 1988). The A.A. define a type of organization to achieve a continual intervention in the erecting yards.

[Risks from volatile anesthetics in operating rooms of Umbrian hospitals]. / Rischi da anestetici volatili nelle sale operatorie degli ospedali Umbri.

The present report is a research on air samples taken in the operating theatres environment in the hospitals of Umbria to control in order the concentration of anaesthetics in use and to define ambient pollution and to propose changes. The A.A. have divided operating theatres in for groups to analyze the data: 1) operating theatres where there were both systems: air change system and air intake system; 2) operating theatres where there was only the air-change system; 3) operating theatres where there was only the air intake system; 4) operating theatres where there were no systems. These data have been compared with the limit values advised by N.I.O.S.H. The lowest value of pollution have been recorded in those operating theatres with both systems. The A.A. have also compared the ethrane or other alogenated anaesthetics values in the air-change system equipped operating theatres with those (values) found in the intake-air system equipped operating theatres. The lowest values have been recorded in those operating theatres with normal air-change system. Where changes have been made to improve the operating theatres environment, the A.A. have effectuated new controls and found lower values of the anaesthetics levels. The concentration of anaesthetics appeared lower then before.

Rem sleep brady-arrhythmias: an indication to pacemaker implantation?

OBJECTIVES: Important adjustments in the autonomic nervous system occur during sleep. Bradycardia, due to increased vagal tone, and hypotension, caused by reduction of sympathetic activity, may occur during non rapid eye movement (REM) sleep (NREM). Increased sympathetic activity, causing increased heart rate, is conversely a feature of phasic REM sleep. During REM sleep, sinus arrests and atrioventricular (AV) blocks unrelated to apnea or hypopnea have been described. These arrhythmias are very rare and only a few cases have been reported in the literature. PATIENTS/METHODS: Following an ECG performed for other reasons, two patients with no history of sleep complaints nor symptoms of heart failure or heart attack were referred to our center for nocturnal brady-arrhythmias. RESULTS: 24h ECG Holter recorded several episodes of brady-arrhythmia with sinus arrest in the first patients and brady-arrhythmias with complete AV block in the second patient. In both patients, episodes of brady-arrhythmia were prevalent in the second part of the night. Nocturnal polysomnography (PSG) demonstrated that episodes occurred only during REM sleep, particularly during phasic events. Treatment with pacemaker was considered only for the patient with complete AV blocks. CONCLUSIONS: These types of brady-arrhythmias are usually detected accidentally due to their lack of symptoms. It has been suggested that in some patients they may lead to sudden unexpected death. Thus, the identification of predisposing factors is mandatory in order to prevent potentially dangerous arrhythmic events.

Fractionation and characterization of a conjugate between a polymeric drug-carrier and the antitumor drug camptothecin.

A conjugate between the antitumor drug camptothecin and the polymeric drug-carrier poly[N-(2-hydroxypropyl)methacrylamide] was synthesized and fractionated. The conjugate samples, both fractionated and unfractionated, were characterized with a multi-detector SEC system using three on-line detectors: a multi-angle light scattering photometer, a viscometer, and a refractometer. The used mobile phase (DMF + 0.01 M LiBr + 0.05 M CH(3)COOH) derives from previous experience with similar conjugates. Narrow molar mass distribution fractions of the conjugate obtained by means of a semipreparative LC system were used to derive the coefficients of the Mark-Houwink-Sakurada relationship and to check the universal calibration of the SEC system. This study has demonstrated that the conjugate elutes according to the hydrodynamic volume. Thus, a conventional SEC method that uses only an on-line refractometer detector, commercially available narrow standards, and the universal calibration is adequate for the characterization of the molar mass distribution. Also the size and the conformation of the conjugate were studied by means of the gyration radius-molar mass power law.

Mechanism of suramin-induced deoligomerization of tumor necrosis factor alpha.

Deoligomerization of human tumor necrosis factor alpha (TNF), spiked with 125I-labeled form, was studied quantitatively using size-exclusion chromatography and off-line monitoring with a gamma-counter. A detailed investigation of the oligomeric state of TNF was carried out as a function of its own concentration (0.3-7500 nM referred to the subunit, M(r) 17,000) in the absence or in the presence of various amounts (10, 100, 1000 microM) of suramin, an inhibitor of TNF biological activity in vitro, which promotes TNF deoligomerization. The dependence of trimeric form content on total TNF concentration was modeled with a sequential dissociation process (trimer-->dimer-->monomer) assuming an identical dissociation constant for each step, Kd1 = 0.2 nM. This model was used as the simplest for data fitting although, generally, no chromatographic resolution of dimeric species could be obtained. Best fitting of all data could be achieved with a model including a conformational change of TNF trimer into a state more prone to deoligomerization (Kd2 = 400 nM), which was favored by suramin binding. A kinetic study of TNF dissociation by the same method produced values for the deoligomerization rate of trimer: on the average, koff approximately 4 x 10(-5) S-1 (t1/2 approximately 5 h) between 4 and 20 degrees C with little dependence on suramin concentration; at 37 degrees C, a sizable increase is observed in the presence of 1 mM suramin (koff = 2.3 x 10(-4) S-1, t1/2 = 0.8 h). Data of suramin inhibition on TNF receptor binding, as obtained after incubation times much shorter than the above half-life of trimer, indicate that suramin binding to TNF trimer is the early mechanism of receptor binding inhibition.