Biomedical subjects
Publications and source records attributed to A Pierangeli.
Graft right ventricular failure after heart transplantation, secondary to preoperative functional pulmonary hypertension, was successfully managed in a 49-year-old patient using an extracorporeal right to left atrial bypass. We comment on the case and discuss the type of mechanical assistance used.
The problems related to the pediatric pulmonary homograft availability and the possible transmission of viral infection led us to design a new patch for aortic enlargement in the Norwood procedure for hypoplastic left heart syndrome. This sterile bovine pericardial patch is not expensive and can be tailor-made.
PURPOSE: To assess the value of magnetic resonance (MR) imaging in the detection of postoperative complications after composite valve graft replacement. MATERIALS AND METHODS: Spin-echo and gradient-echo MR imaging was performed in 52 patients 1/2 to 200 months after composite graft replacement of the ascending aorta (22 for dissection, 30 for aneurysm). The prosthetic aortic segment, distal and proximal anastomoses, general morphologic characteristics, and diameter of the reimplanted coronary arteries were evaluated. In patients with abnormal perigraft thickening, additional spin-echo imaging was performed after injection of gadopentetate dimeglumine. RESULTS: Normal postoperative perigraft thickening (< or = 10 mm) was observed in 42 patients. Ten patients had abnormal periprosthetic thickening of 15-52 mm. Gadolinium-enhanced MR imaging demonstrated leakage in five of those 10 patients. The lack of enhancement excluded the presence of bleeding in the remaining five patients (three with chronic hematomas, one with infection, and one with granulation tissue). These findings were confirmed at surgery or with subsequent follow-up MR examinations. CONCLUSION: MR imaging was an optimal imaging modality for evaluating the morphologic characteristics of composite grafts and reimplanted coronary arteries. Gadolinium-enhanced MR imaging is a simple, accurate, and noninvasive method for detecting a leak, which necessitates urgent repeat surgery.
Spontaneous coronary artery dissection is a rare cause of myocardial infarction associated with a significant high morbidity and mortality. It usually occurs in relatively young patients and it is frequently found at autopsy. We report a case of a 42-year-old woman, who underwent resection of subaortic diaphragm ten years earlier presenting with postero-lateral myocardial infarction. Coronary arteriography revealed a dissection of the left main stem extending distally to the left anterior descending artery (LAD) and circumflex artery (Cx); occlusion of the postero-lateral branch of the Cx; severe aortic valve regurgitation and ascending aortic aneurysm. She was successfully operated on in emergency and underwent myocardial revascularization and separate replacement of the aortic valve and the ascending aorta. In this specific case of coronary dissection and severe aortic regurgitation it is mandatory to perform surgery in emergency to limit infarction evolution and avert loss of life.
METHODS: 169 selected patients with previous AMI and inducible sustained ventricular tachycardia (sVT) at electrophysiological study (EPS) were followed-up prospectively for recurrent sVT during a five year period. At EPS, ventricular effective refractory period (VERP)/action potential duration (APd) ratio, ventricular conduction velocity, excitable gap, cycle length and QRS duration were measured. The patients with inducible sVT at basic programmed stimulation or after isoproterenol infusion (200 micrograms i.v.) underwent drug suppression tests (amiodarone, procamide, propanolol + procamide, amiodarone + propaphenone). On this basis, they were later assigned to 3 different groups: the amiodarone-treated group (n = 112), the procamide-treated group (n = 22) and the nonresponder group (control group, n = 35). RESULTS: After procamide infusion (100 mg/min for 10 min), at fast pacing drive the VERP/APd ratio was significantly increased from baseline levels (p < 0.001), the conduction velocity (Vmax) was significantly depressed (by 25%, p < 0.005), the excitable gap was significantly reduced (p < 0.005, 23% of cycle length) and 71 patients were no longer inducible; during sinus rhythm, Vmax was significantly reduced from baseline values (by 14%, p < 0.05), VERP was only moderately increased and the excitable gap was slightly but significantly prolonged (p < 0.01, 53% of cycle length): 147 patients were still inducible, without significant difference from baseline values. After amiodarone infusion (300 mg/100 ml i.v. over 10 min), Vmax was significantly reduced from baseline levels at fast pacing drive (by 21%, p < 0.001), while the excitable gap did not reduce significantly (34%) from baseline levels and 91 patients were still inducible; during sinus rhythm, conduction velocity was moderately depressed (by 7%, p < 0.05), while VERP was significantly increased from baseline levels (p < 0.002) and the excitable gap was significantly reduced (p < 0.001, 29% of cycle length); only 35 patients were still inducible. In the remaining 134 patients the reset curve showed excitable gaps = 24 +/- 3% of the cycle length. The absolute and relative values of the excitable gap measured in the 35 patients who were still inducible were significantly higher than those measured in patients no longer inducible (p < 0.05). At follow-up, the sVT recurrence rate was: 28% in the amiodarone-treated group, 43% in the procamide-treated group and 36% in the control group: control data were significantly different from the former (p < 0.05) but not from the latter group. Significant correlation was reported between the plasmatic concentration of procamide and amiodarone and the percentage of reduction of Vmax at fast pacing drive (r = 0.79, p < 0.05; r = 0.83, p < 0.01). Resulting variability checked by the analysis of variance showed no significant difference between the two series (p < 0.12638). The development of conduction velocity depression was clearly dose-dependent. Drug suppression test with procamide + propanolol resulted in noninducibility of sVT in 115 patients, with strong significant difference from when the drug was used alone (p < 0.0015). Better results at EPS were obtained by the combination amiodarone + propaphenone, although no additional benefit was reported when compared with amiodarone alone. CONCLUSIONS: In conclusion, antiarrhythmic drugs with class I action may be highly effective in terminating sVI (lidocaine, procamide) but may be ineffective in preventing it or even arrhythmogenic. According to our data, drugs with class III antiarrhythmic action showed significantly different behavior: they were more effective in prolonging refractoriness and reducing the excitable gap at longer cycle lengths and, thus, capable of preventing, rather than terminating. Although statistical difference was reported between the amiodarone-treated group and the control group, the incidence of recurrent sVT remained too high to consider drug therapy as
PURPOSE: To determine whether endovascular treatment of thoracic aorta conditions can be an effective alternative approach to surgical repair. MATERIAL AND METHODS: July 1997 to February 1999, eighteen patients (16 men and 2 women; 58.6 +/- 14.8 years) presenting with different kinds of descending aorta conditions were selected for the endovascular treatment. All patients exhibited severe comorbid pulmonary and/or cardiovascular medical conditions which increased surgical risk. All implants were performed in the operating room under fluoroscopic and TEE guidance. Clinical and imaging follow-up was performed 1, 3, 6 and 12 months later. RESULTS: The endovascular treatment was successful in 17 cases. No deaths or major complications occurred. No leakage was evident at post-procedure angiography. The patients were discharged after 6 +/- 4 days. MRI or CT study performed before hospital discharge showed aneurysms exclusion in 16 patients. In the four cases of dissection, thrombosis of the false lumen was evident since the first follow-up study. In the group of patients (11 cases) with 6 months follow-up, the diameters of stented aortic segments decreased. No late leakage was observed and thrombosis was complete in all cases. DISCUSSION: The natural history of aortic aneurysms and dissection is progressive toward dilation and aortic rupture. Surgery of descending thoracic aorta is burdened with a mortality of 8-12% in elective cases and over 50% in emergency cases or aortic dissection. The endovascular treatment of aortic conditions was introduced in clinical practice in 1991 and literature data show that it is effective, with lower mortality and morbidity rates than surgical treatment. CONCLUSION: Our results stress the feasibility and effectiveness of endovascular procedure in the treatment of complex thoracic aorta conditions even in high risk patients. Thus, endovascular treatment of thoracic aorta can be considered an effective alternative approach to conventional surgery.
Protein synthesis directed by hepatitis A virus (HAV) RNA is mediated by a mechanism involving the recognition of internal sequences. Two in-frame AUG codons initiate the long open reading frame (positions 734-736 and 740-742). The extra-cistronic region extending between the uncapped 5'-end and the ORF contains two pyrimidine-rich tracts (PRTs): one 12 nucleotides in length in the close vicinity of the initiator AUG, and a longer one between bases 94 and 140. In order to study the relative contribution of these elements to the process of internal initiation of translation, cDNA representations of the 5'-terminal extra-cistronic region of HAV RNA were inserted in the intergenic region of the bi-cistronic plasmid pSV-GH/CAT, between the genes encoding the human growth hormone (GH) and the bacterial enzyme chloramphenicol acetyltransferase (CAT), and following transfection of COS-1 cells, the transient expression of both genes was quantified. The importance of the 3'-PRT appeared to be strongly influenced by the length of the 'spacer' sequence extending between this structure and the translation initiation site: placed 45 nucleotides upstream from the initiator codon of a reporter gene, its integrity was stringently required for initiation to occur. Bringing the length of the 'spacer' back to its actual size in HAV RNA (i.e. 11 or 17 nt) reduced considerably the overall rate of internal initiation of translation, and the relative contribution to this process of the 3'-PRT became marginal. Concomitantly, the importance of the functional domains previously identified in the 5'-PRT fluctuated: while integrity of domain 100-106 was always stringently required for initiation to occur, the activity of domain 113-118 paralleled that of the 3'-PRT, and the opposite applied to domain 121-126, whose contribution became relevant only after switching off the 3'-PRT. Systematic mutations introduced in the 'spacer' sequences suggest that the length of this region may be responsible for the down regulation of translation of HAV RNA and, possibly, for its lengthy replication cycle.
BACKGROUND: The outcome of patients with acute traumatic rupture of the thoracic aorta after motor vehicle accidents is strongly conditioned by injuries to other districts. The timing of repair is controversial when the patients arrive alive to the hospital. METHODS: A series of 42 patients with acute traumatic rupture of the thoracic aorta observed between January 1980 and June 1996 was divided into two groups: group I underwent immediate repair (21 patients) and in group II operation was performed after intensive medical treatment and management of the associated lesions and monitoring of the aortic tear. RESULTS: The mortality in group I patients was 19% and the morbidity was more significant than in group II where no deaths were reported and complications were minor. CONCLUSIONS: Patients with acute traumatic rupture of the thoracic aorta may have a better fighting chance if aortic operation is postponed to the most favorable moment after undergoing life-sustaining measures and management of the major associated lesions. Needless to say, evolution should be closely monitored by computed tomographic scans and magnetic resonance imaging.
BACKGROUND: In dynamic cardiomyoplasty electro-stimulation achieves full transformation of the latissimus dorsi (LD); therefore, its slowness limits the systolic support. Daily activity-rest could maintain partial transformation of the LD. METHODS: Sheep LD were burst-stimulated either 10 or 24 hours/day. Before and 2, 4, 6, and 12 months after stimulation, LD power output, fatigue resistance, and tetanic fusion frequency were assessed. Latissimus dorsi were biopsied at 6 months, and sheep sacrificed at 12 months. RESULTS: After 1 year of 10 hours/day stimulation LD was substantially conserved and contained large amounts of fast type myosin. From 2 months to 1 year of stimulation the power per muscle of the daily rested LD was greater than that of the left ventricle, being three to four times higher than in the 24-hour/day stimulation. CONCLUSIONS: If extended to humans, these results could be the rationale for the need of a cardiomyostimulator, whose discontinuous activity could offer to patients the long-standing advantage of a faster and powerful muscle contraction.
Human papillomaviruses (HPVs) are epithelium-tropic viruses associated with several cutaneous, epithelial, and mucosal lesions. The oncogenic potential varies considerably among the more than 70 different genotypes so far identified. HPV 6 and 11 are generally found in benign genital condilomata or laryngeal papillomas, but they have been sporadically associated with genital malignancies. Polymerase chain reaction (PCR) primed by degenerated consensus oligonucleotides (from a late region of the HPV genome) allows one to amplify a broad spectrum of HPV, whereas the amplification with specific primers is restricted to a limited number of HPVs. Therefore, the restriction fragment length polymorphism assay permits one to identify the HPV type present in the PCR product. We report a case of an invasive verrucous carcinoma of the penis associated with HPV 11, a type previously considered noncarcinogenic.
OBJECTIVES: A recent surgical series documented that in traumatic aortic rupture (TAR) a surgical repair postponed to the treatment of associated lesions reduced operative and overall mortality. Nevertheless some isolated cases may develop to free rupture. Until now, no imaging follow-up studies of post-traumatic aortic lesions have been reported in the early stage. The aim of this study is to analyze the behaviour of traumatic aortic ruptures in the subacute phase, in order to detect the morphological characteristics of unstable post-traumatic aneurysms. METHODS: Twenty-five consecutive patients affected by traumatic aortic rupture (one intimal hemorrhage, 19 partial lesions and five circumferential lesions) were admitted to the department of cardiac surgery. Magnetic resonance imaging (MRI) was the imaging method used to confirm the diagnosis. No one was operated on during the acute phase. All patients were treated with beta-blockers and vasodilators as well as limited fluid administration. Delayed surgery was carried out in 18 patients at 243 days (+/-127), after the resolution of associated lesions. A scheduled MRI follow-up was performed at 7, 15 and 30 days and immediately before the operation. The parameters examined were increase of post-traumatic aneurysm, increase of periaortic hematoma and modification of the thoracic associated lesions. RESULTS: At 30 days a 3.0 +/- 3.7 mm median increase of the aneurysm was observed, while in the subsequent period the lesions became substantially stable, resulting in a 4.4 +/- 3.6 mm increment at the end of the follow-up. The circumferential lesions presented a higher increment with respect to the partial lesions. In three cases an augmentation of 6, 7 and 12 mm was detected and surgical repair was anticipated. In 13 cases a periadventitial hematoma surrounding the aortic aneurysm decreased through the time. One case of intimal hemorrhage healed spontaneously, with no aneurysm formation. Thoracic associated lesions (pleural and pericardial effusions, rib fractures, lung focal contusions and two cases of ARDS) resolved at 30-60 days. CONCLUSIONS: Despite common knowledge, considering TAR highly evolutive in the acute and subacute phase, this study demonstrated that this pathological entity is relatively stable if a proper pharmacological treatment is administrated. MRI follow-up is recommended in order to detect isolated cases of unstable aneurysm.
Human papillomavirus (HPV) is associated with benign cutaneous or mucosal lesions and with malignant tumours, but none of the HPV types has so far been related to skin tags. Skin biopsy specimens from 49 Caucasian patients suffering from the presence of multiple soft fibromas were analysed by means of dot blot hybridization and by polymerase chain reaction assays aimed at detecting all known HPV types. The results revealed the presence of HPV DNA type 6/11 in 88% of the skin tags examined. This result supports the hypothesis that HPV plays a part in the progression of cutaneous soft fibromas, as previously reported for laryngeal papillomas.
Translation of the uncapped poliovirus RNA starts at the AUG triplet spanning positions 741-743, and proceeds uninterrupted for almost the entire length of the genome. Such a cap-independent mechanism of internal initiation of translation determines that a long, extra-cistronic region extends between the 5'-end and the main open reading frame (ORF). We have identified 10 short ORFs initiated by the alternative translation initiation codons ACG, AUA, and GUG in the 5'-terminal extra-cistronic region (5'-ECR) of poliovirus RNA. Mutations introduced in all but one of these mini-cistrons had no effect on the infectivity of full-length cDNA clones, except when they modified a "hidden frame" spanning between nucleotides 157-192 (starting triplet: ACG). The mini cistron 157-192 is conserved in position, length and sequence in the genome of all types and strains of poliovirus. Adaptation to rat (Lansing) or mouse (variant of Sabin 2) is accompanied by a consistent pattern of changes in the primary sequence of this "hidden frame". The substitutions that abrogated the infectivity of cDNA clones were not expected to modify the predicted secondary structure of the 5'-ECR, and they did not alter the ability of the IRES to direct internal initiation of translation in bi-cistronic mRNAs. The infectivity of the mutated poliovirus cDNAs could be complemented in trans by co-transfecting the target COS-1 cells with an expression vector containing just the 5'-ECR of poliovirus type 2 (Lansing strain). The infectivity of poliovirus cDNA could be restored by co-transfecting short RNA transcripts of the wt 5'-ECR (Lansing), suggesting that the complementation in trans indeed requires the expression of the helper cDNA clone.
The genomic RNA of Hepatitis A virus (HAV), a picornavirus of the hepatovirus group, is a single-stranded molecule, ca. 7.5 kb in length of positive polarity. Translation of this uncapped RNA starts at the 10th (or 11th) AUG triplet (position 734-36), by a mechanism of internal initiation of translation. The long sequences extending between the uncapped 5'-end and the translation initiation site contain two (instead of just one) pyrimidine-rich tracts (PRTs) spanning nucleotides 94-140 and 711-724, respectively. The latter lies only 11 nucleotides upstream from the initiation site of translation, and the question arose as to whether the notoriously poor replication ability of HAV was a consequence of a down regulation of translation due to the too short "spacer" sequence intervening between the 3'-PRT and the initiation of the main open reading frame. To address this issue, a series of full-length HAV cDNA clones were constructed in which the "spacer" sequence (normally 11 nts) was brought to 45 nts. Following transfection of COS-1 cells with these constructs, the amount of HAV (+)-strand RNA was determined by dot hybridization using a strand-specific RNA probe. HAV cDNA clones carrying a 45-nt "spacer" increased two-fold the rate of (+)-strand viral RNA synthesis, suggesting that the poor translation ability of HAV RNA may be one of the mechanisms responsible for the lengthy replication cycle of HAV.
BACKGROUND: Many pathogens may be responsible of Non Gonococcal Urethritis (NGU) with the possible occurrence of symptomatic and asymptomatic mixed viral and bacterial infections. In particular, genital papillomaviruses (HPVs) have been searched since they are linked to both benign and malignant lesions of the penis and urethra and the presence of a potential male carried state has received limited scrutiny while the screening of sexually active females has received substantial attention. METHODS: In male patients affected by chronic NGU, the presence of DNA of Chlamydia trachomatis, herpes simplex virus (HSV) type 1 and 2 and human papillomaviruses by PCR and the occurrence of Gram positive and Gram negative micro-organisms, of Mycoplasma hominis and Ureaplasma urealyticum, by conventional cultural methods have been investigated. RESULTS: Results obtained indicated a high percentage of mixed infections, up to 36%. Genital HPV DNA was detected in 31% of specimens positive for two or more agents, and HSV DNA was detected in 10% of studied population. CONCLUSIONS: The concomitant presence of different infectious agents could determine latent, sub-clinical or chronic infections with periodic reactivation. In particular results suggest that HPV and HSV may stimulate cytokine production which can up regulate the expression of other infectious agents and may be responsible for latent chlamydial infections characterised by the persistence of this micro-organism in an altered form, viable but in a culture negative state. Therefore an increased awareness of mixed infections is relevant to define the management and treatment of chronic urethritis.
Primary benign tumors of the heart are particularly rare; cardiac hemangioma is one of the most rare primary benign cardiac tumors. Natural history, symptoms and prognosis of the disease depend on the potential complications due to the location and diffusion of the mass. We report on 2 cases of cardiac hemangioma, diagnosed occasionally in the first patient or due to gastroenteric symptoms in the second patient. The diagnosis was obtained by 2-D-echo and magnetic resonance imaging. In both cases the hemangioma was located on the right ventricle. Both patients underwent tumor resection in hypothermic cardiopulmonary bypass. In one case, a graft to the right coronary artery was associated; in the other case, the right ventricular outflow tract was reconstructed with an infundibular patch. Histology showed mixed hemangioma in one case and cavernous hemangioma in the other. The postoperative course was uneventful. At a follow-up of 8 years and 1 year, respectively, both patients are classified as NYHA 1 and both 2-D-echo and magnetic resonance imaging did not show any residual tumoral mass. This experience demonstrates that, depending on their location, benign neoplastic masses may be radically resected with acceptable operatory risks and excellent long-term results.
BACKGROUND: Traumatic aortic rupture (TAR) is a pathological entity with a high mortality, both spontaneous and perioperative. Delayed surgical repair has been proposed when associated lesions are stabilized. The aim of this study was to validate MRI for detecting both the presence and type of TAR and to monitor posttraumatic aneurysm and associated lesions. METHODS AND RESULTS: Twenty-four consecutive patients with acute chest trauma and suspected aortic rupture, as suggested by emergency CT or chest radiographs, were subjected to MRI and/or angiography in random order. Such parameters as the presence and type of lesion; presence of periaortic, pericardial, mediastinal, or pleural effusion; and presence of associated lesions were considered in every patient. Follow-up imaging was performed exclusively by MRI every 1 to 2 months. TAR was present in 20 patients. No patient underwent surgery in the acute phase; 14 patients underwent surgery at 6.8 +/- 2.7 months; 5 are waiting for surgery; and 1 healed spontaneously. There was no overall mortality. For detection of TAR, the accuracy of MRI was 100%; angiography, 84%; and CT, 69%. In detecting the type of lesion, the diagnostic accuracy of MRI was 92%. During follow-up, a significant increase in the posttraumatic aneurysm was observed in 2 patients, and surgical repair was initiated. CONCLUSIONS: In chest trauma patients, MRI provides complete anatomic data to assess the severity of aortic and thoracic lesions. Moreover, along with the concept of delayed surgical repair of TAR, MRI is the ideal modality to monitor and follow TAR before surgical repair.
The aims of this study were: (1) to assess whether variations in cyclic echo amplitude might be detected across the human myocardium by videodensitometric analysis of images obtained with epicardial echocardiography; and (2) to explore the possible relation between cyclic gray level variation and left ventricular (LV) hypertrophy and function. Experimental studies show that transmural differences in contractile performance across the normal myocardium are paralleled by differences in the cyclic (diastolic-to-systolic) variation of myocardial echo amplitude. Thirty-three patients (aged 60 +/- 11 years) undergoing cardiac surgery were studied by intraoperative epicardial echocardiography. LV mass index as normal (<110 g/m2 in women, <131 g/m2 in men) in 10 patients and increased in 22. Two-dimensional echocardiographic images were obtained with a 5 MHz transducer and digitized off-line. Videodensitometric analysis was performed at end-diastole and end-systole with regions of interest across the septal and posterior wall. The cyclic variation was more pronounced in the left than in the right septal subendocardium (31% +/- 14% vs 16% +/- 14% <0.01) and higher in the subendocardial than in the subepicardial layer of the posterior wall (30% +/- 21% vs 23 +/- 18%, p <0.01). Cyclic variation of the left septal subendocardium was higher in 11 patients with nonhypertrophic ventricles than in 22 with hypertrophic left ventricles (42% +/- 15% vs 27% +/- 12%; p <0.01). The percent cyclic variation of the left septal subendocardium appeared to be much more tightly related to percent systolic thickening in patients with eccentric LV hypertrophy (r=0.80 p <0.01) than in patients with concentric LV hypertrophy (r=0.27, p=0.9) or normal LV mass (r=0.43, p=0.2). A cyclic gray level variation can be consistently detected in different human myocardial regions and layers. It is more obvious in the subendocardial than in the subepicardial layer, and in nonhypertrophic than hypertrophic ventricles. The cyclic subendocardial variation is tightly related to regional systolic thickening in patients with eccentric LV hypertrophy.