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Biomedical subjects

C Nardi

Publications and source records attributed to C Nardi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Combined mitral and tricuspid valve repair in acute infective endocarditis.

Combined repair of the mitral and tricuspid valves involved with acute infective endocarditis was carried out in a 38-year-old drug addict. Mitral valve repair included vegetectomy, closure of posterior leaflet perforation, and posterior annuloplasty with a patch and a strip of glutaraldehyde-tanned autologous pericardium, respectively, while the tricuspid valve was reconstructed with the use of artificial chordae and valve bicuspidalization. At five months follow up the patient is asymptomatic, with echocardiographic evidence of only trivial mitral and tricuspid incompetence, and no signs of recurrent infection. This case report supports the use of valve reconstruction as a valuable option in patients in whom there is simultaneous involvement of the mitral and tricuspid valves with infective endocarditis.

Adult↗
PubMed1999

Prospective evaluation of frequency and nature of transcranial high-intensity Doppler signals in prosthetic valve recipients.

BACKGROUND AND AIM OF THE STUDY: In asymptomatic prosthetic valve recipients, high-intensity transient signals (HITS) observed with transcranial Doppler (TCD) are a phenomenon of obscure clinical relevance which nature has not yet been elucidated convincingly. METHODS: Eighty-three patients without carotid disease, history of cerebrovascular accidents, and with negative preoperative TCD undergoing either valve replacement (mitral, n = 11; aortic, n = 56; mitral + aortic, n = 6; 40 mechanical prostheses, 29 biological prostheses, 10 homografts) or mitral repair (n = 10) were evaluated prospectively by means of TCD at discharge, three months and one year after surgery, to analyze the presence, incidence and characteristics of HITS. Furthermore, in 12 patients positive for HITS, TCD was repeated during a 30-min period of 100% O2 inhalation. RESULTS: Twenty-five patients (30%) were positive for HITS at all postoperative controls, although no neurological symptoms were observed. Mechanical prostheses showed a significantly higher incidence of HITS (85%) than biological prostheses (10%, p <0.001), repaired mitral valves (0%, p <0.001) and homografts (0%, p <0.001). At multivariate analysis the presence of a mechanical prosthesis was the only significant predictor of detection of HITS after valve replacement. During O2 inhalation, a significant decrease in the number of HITS per hour (55 +/- 79 versus 22 +/- 31, p = 0.002) occurred, which returned to initial values when room-air breathing was resumed. CONCLUSIONS: Prosthetic valve replacement, particularly when mechanical devices are used, is associated with the generation of HITS which persist throughout the follow up period, but remain clinically silent. The decrease of HITS during O2 inhalation strongly supports the hypothesis of the gaseous nature of such signals and confirms the validity of this method in helping to differentiate gaseous microemboli from solid microemboli in prosthetic valve recipients.

Adult↗
PubMed1998

Quadricuspid aortic valve.

A quadricuspid aortic valve was observed in a patient requiring aortic valve replacement because of severe aortic regurgitation, while in another it was accidentally detected by means of transesophageal echocardiography performed during coronary artery bypass grafting. This report discusses the apparent rarity of this malformation and stresses the need for periodical controls in patients known to have a quadricuspid aortic valve.

Adult↗
PubMed1998

Multiple enzymatic activities associated with recombinant NS3 protein of hepatitis C virus.

The hepatitis C virus (HCV) nonstructural 3 protein (NS3) contains at least two domains associated with multiple enzymatic activities; a serine protease activity resides in the N-terminal one-third of the protein, whereas RNA helicase activity and RNA-stimulated nucleoside triphosphatase activity are associated with the C-terminal portion. To study the possible mutual influence of these enzymatic activities, a full-length NS3 polypeptide of 67 kDa was expressed as a nonfusion protein in Escherichia coli, purified to homogeneity, and shown to retain all three enzymatic activities. The protease activity of the full-length NS3 was strongly dependent on the activation by a synthetic peptide spanning the central hydrophobic core of the NS4A cofactor. Once complexed with the NS4A-derived peptide, the full-length NS3 protein and the isolated N-terminal protease domain cleaved synthetic peptide substrates with comparable efficiency. We show that, as in the case of the isolated protease domain, the protease activity of full-length NS3 undergoes inhibition by the N-terminal cleavage products of substrate peptides corresponding to the NS4A-NS4B and NS5A-NS5B. We have also characterized and quantified the NS3 ATPase, RNA helicase, and RNA-binding activities under optimized reaction conditions. Compared with the isolated N-terminal and C-terminal domains, recombinant full-length NS3 did not show significant differences in the three enzymatic activities analyzed in independent in vitro assays. We have further explored the possible interdependence of the NS3 N-terminal and C-terminal domains by analyzing the effect of polynucleotides on the modulation of all NS3 enzymatic functions. Our results demonstrated that the observed inhibition of the NS3 proteolytic activity by single-stranded RNA is mediated by direct interaction with the protease domain rather than with the helicase RNA-binding domain.

Adenosine Triphosphatases↗
PubMed1998

Enlargement of the aortic annulus with glutaraldehyde-fixed bovine pericardium during aortic valve replacement.

BACKGROUND AND AIMS OF THE STUDY: Aortic valve replacement in patients with a small aortic annulus may represent a surgical challenge. We have evaluated a simplified technique to enlarge the aortic annulus which consists of extending the aortotomy incision to divide the commissure between the left and non-coronary cusps into the interleaflet triangle without opening the left atrium. METHODS: This technique was used in 16 patients (15 women, one man; mean age 66 +/- 9 years) who underwent aortic valve replacement between August 1994 and February 1996. Aortic stenosis was the predominant valvular lesion. A mechanical prosthesis was implanted in 13 patients (81%) (21 mm in six, 23 mm in seven) while three received a bioprosthesis (21 mm in one, 23 mm in two). In all patients it was possible to insert a prosthesis at least one size larger than the original aortic annulus diameter. RESULTS: There were no operative deaths and no late deaths. Mean follow up was 20 +/- 6 months (range: 12 to 30 months). Echocardiographic controls at 12 months postoperatively showed no evidence of periprosthetic leaks or mitral regurgitation. Comparison with preoperative data showed no significant variations of mean aortic diameter at the sinus level (30.7 +/- 2.2 mm versus 31.3 +/- 2.6 mm) or at the sinotubular junction (33.6 +/- 2.7 mm versus 34.3 +/- 2.9 mm) (p = NS). Significant reduction of left ventricular mass was observed (314 +/- 57 g versus 260 +/- 45 g; p < 0.001). CONCLUSIONS: This technique is simple, reproducible and effective in allowing adequate enlargement of the aortic annulus and provides excellent clinical and hemodynamic results. Glutaraldehyde-fixed bovine pericardium used as a patch material showed no tendency to aneurysmal dilatation with progression of time at a maximum follow up of 30 months.

Aged↗
PubMed1998

Aortic valve replacement for quadricuspid aortic valve incompetence.

Quadricuspid aortic valve is an uncommon cause of aortic regurgitation. We report two patients who underwent aortic valve replacement because of severe aortic incompetence; the presence of a quadricuspid aortic valve was an accidental surgical finding. In one patient the aortic valve comprised two equal-sized larger cusps and two equal-sized smaller cusps, while in the other it comprised three cusps of similar size and a small accessory cusp between the right and non-coronary cusps. This report confirms the rarity of the disease and the fact that patients with quadricuspid aortic valves characterized by cusps of different sizes are more prone to develop progressive aortic incompetence because of unequal distribution of stresses on the valve. Therefore, such patients should undergo periodic, life-time echocardiographic assessment once this malformation is detected.

Aged↗
PubMed1997

Hemodynamic performance of the Edwards Prima stentless valve.

BACKGROUND AND AIM OF THE STUDY: Stentless porcine valves are considered to have a superior hemodynamic performance when compared with stented bioprostheses. In the present study we report our initial experience with the Edwards Prima stentless valve (EPSV), focusing on the hemodynamic performance of this device evaluated by means of transthoracic two-dimensional (2D) Doppler echocardiography. METHODS: Between December 1994 and August 1995, 23 patients underwent aortic valve replacement with the EPSV implanted in the subcoronary position. Evaluation of hemodynamic performance of the EPSV was assessed before discharge (one week) and at six months follow up by means of transthoracic 2D echocardiography. RESULTS: There were no operative deaths and no major postoperative complications. Hemodynamic data were available for comparison at one week and six months in 18 patients (23 mm, n = 8; 25 mm, n = 10). For 23 mm EPSV, peak gradient varied from 42.7 +/- 10.2 mmHg at one week to 29.7 +/- 9.8 mmHg at six months (p = 0.01); for 25 mm EPSV, peak gradient varied from 33.6 +/- 10.6 mmHg at one week to 29.5 +/- 6.5 mmHg at six months (p = N.S.). CONCLUSIONS: The EPSV, when used in the subcoronary position, has been associated with high early transprosthetic gradients which only partly regress at six months. Gradients are probably caused by the inward folding of the Dacron cloth beneath the right coronary ostium and were recorded especially in patients with aortic stenosis in whom the right coronary ostium was close to the aortic annulus. In such patients alternative implantation techniques should be considered.

Aged↗
PubMed1997

[Transmyocardial revascularization with a holmium laser: preliminary results].

BACKGROUND: Transmyocardial laser revascularization (TMLR) aims to improve perfusion of the ventricular wall via laser-created transmural channels. We present the results of TMLR with a holmium laser as sole therapy in patients with angina refractory to medical treatment and extensive coronary artery disease unsuitable for angioplasty or coronary artery by-pass grafting. METHODS: From November 1995 to February 1997, twenty-two patients underwent isolated TMLR with a holmium laser. Five patients (23%) were female; the mean age was 67 +/- 7 years (range 53 to 74 years). Previous myocardial revascularization procedures had been performed in 17 patients (77%). Mean preoperative angina class was 3.4 +/- 0.5 and unstable angina was present in 7 patients (32%). RESULTS: There were no hospital deaths. The only postoperative complications were transient supraventricular arrhythmias in 6 patients (27%). Each patient received a mean of 33 +/- 8 channels in 27 +/- 13 minutes. There were two late deaths, 40 days and 4 months after TMLR, due to stroke and myocardial infarction, respectively. Mean follow-up duration was 8 +/- 5 months (range 40 days-15 months). The mean number of hospitalizations due to angina fell from 4.9 +/- 1.5 in the 6 months before TMLR to 1.5 +/- 1.0 in the 6 months following surgery (p < 0.001). At follow-up, mean angina class had significantly improved (1.8 +/- 0.6, p < 0.001), as well as effort tolerance, which increased from a mean of 3.5 +/- 1.4 minutes to 5.1 +/- 1.7 minutes (p = 0.01). 201Tl SPECT at 3 and 6 months did not show any significant changes in the segmental perfusion of the lased and unlased areas. CONCLUSIONS: TMLR with a holmium laser is a simple procedure with low operative mortality and morbidity. Short-term results confirm that clinical improvement is obtained in most patients, although this is not supported by significant changes in myocardial perfusion at short-term follow-up.

Aged↗
PubMed1994

Systemic hyperthermia in the treatment of HIV-related disseminated Kaposi's sarcoma. Long-term follow-up of patients treated with low-flow extracorporeal perfusion hyperthermia.

Treatment of HIV and related malignancies with pharmacologic and biologic agents has not appreciably modified the course of disease. Immunologic impairment remains the critical factor in response. We report the long-term results of a single session of low-flow (0.3 L/min) extracorporeal perfusion hyperthermia on 29 men and 2 women with disseminated Kaposi's sarcoma and profound immunologic impairment. Any antiretroviral drug employed by the patient was stopped 72 hours prior to treatment and withheld during the period of follow-up. Core temperature was raised to 42 degrees C and held for 1 hour with extracorporeal perfusion and ex vivo blood heating to 49 degrees C as the means of temperature control. Of 31 patients, 2 died of complications secondary to treatment (cardiac arrhythmia; CNS bleed). There were two cases of intravascular coagulopathy. Pressure point skin damage may occur despite adequate cushioning. At 30 days posttreatment complete or partial regressions were seen in 20/29 of those treated, with regressions persisting in 14/29 of those treated by 120 days posttreatment. At 360 days, 4/29 maintain tumor regressions with 1 in complete remission (at 26 months). The patient in complete remission remains culture-negative and PCR-negative for HIV. CD4+ counts rose from around 250 to, and remain around, 800 in this man. Selected healed lesions were biopsied to demonstrate tumor absence. Patients were selected for treatment if pretreatment testing of the tumor showed regression in vitro with heat exposure. Analysis of the early and midterm failures showed little sustained rise of the CD4+ cells if presenting total CD4+ counts were below 50 and had been at such low levels for extended periods, although other surrogate markers of HIV activity declined (semiquantitative PCR) during this period and is felt to support the hypothesis of apoptosis proposed in this illness. Analysis of the tumors of the few men not responding demonstrated elevated levels of IL-6 as compared to responders (12 vs < 1 pg/ml). At 120 days 29/31 patients remained alive (expected, 20). At 360 days, 21/31 remained alive (expected, 11). In no patient was HIV activity stimulated with heat exposure. CMV retinitis did clear in some patients treated (both techniques), but treatment alone did not prevent later development of retinopathy. EBV parameters were markedly altered in the short term with heat exposure in some patients. Few patients showed herpes simplex activation. Varicella-zoster virus remitted in some patients. There is utility in the use of systemic hyperthermia to control HIV and related malignancy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

Adjustment disorder of conscripts as a military phobia.

Conscription entails many adjustment difficulties for the young soldier. When anxiety is sufficiently severe to impair performance and make discharge a possibility, a brief course of cognitive-behavioral therapy can rapidly restore the soldier to full functioning. This article explains the theoretical basis for such an approach, and describes three cases.

Adjustment Disorders↗
PubMed1992

Systemic hyperthermia in the treatment of HIV-related Kaposi's sarcoma. A phase I study.

Ten Caucasian males with HIV-related Kaposi's sarcoma, a disseminated disease which is refractory to usual therapies, underwent a single session of systemic hyperthermia with maintenance of core temperatures at 42 degrees C for 1 h. One complete remission and 7 partial remissions were identified when assessed 30 days post-treatment. Two mixed responses were noted in patients whose tumors showed autocrine growth. At 60 days 2 of the 7 partial responders began to show tumor progression. The complete remission persisted at 120 days. Surrogate markers of HIV activity fell in all responding patients. In no patient was there evidence of HIV activation. No adverse effects of heating were noted on CMV retinitis. Hairy leukoplakia resolved with heating in all patients. CD4 counts showed no appreciable change in any of the 8 patients with a presenting CD4 count below 60. In the 2 patients who presented with a CD4 count above 400, CD4 counts rose dramatically following treatment. No deaths were noted in this phase I study. The use of systemic hyperthermia in treatment of HIV-related illness warrants further study.

AIDS-Related Complex↗
PubMed1991

Treating post traumatic stress disorder couples: a psychoeducational program.

The effects of veterans' war-related emotional disorders on wives has received little attention in the literature on families and family therapy. Clinical evidence shows devastating effects of combat-related psychopathology on the marriage relationship. Post-traumatic stress disorder can result in chronic marital distress, in addition to veteran disabilities. It is contended here that a clinical couples' therapy model fails to address the specific needs of this population of couples. A cognitive-behavioral analysis of the effects of post-traumatic stress disorder (PTSD) on couple functioning is presented as well as a rationale for treatment based on psychoeducational, cognitive-behavioral, and self-help principles. This paper reviews an experimental program carried out in Israel designed to reach and treat the PTSD couple.

Adaptation, Psychological↗
PubMed1979

[Post-operative subphrenic abscess. Information supplied by analysis of 62 recent unpublished cases (author's transl)].

We have collected 62 cases of post-operative subphrenic abscess. Two thirds of these patients were sent to us by another unit for post-operative complications. Subphrenic asbcess is still very dangerous as the mortality is still 38%. They occurred after a gastro-duodenal operation (26 times), spleno-pancreatic operation (21 times), intestinal operation (15 times), hepato-bilary operation (11 times) appendicectomy (twice). They were situated usually on the right, but 11 patients had a double subphrenic abscess and 14 an associated submesocolic abscess. Gram negative bacteria were usually the cause. These abscesses often started early. They occurred in 80% of cases in patients operated under the antibiotic cover. Chest X-ray was the best method of detection, but experience is necessary to read them. The abscesses were drained by the abdominal route in order to verify th whole peritoneal cavity. 22 patients died. 11 from septicemia. 21 out of 22 had a digestive fistula. Among the factors in prognosis, the most obvious were age, type of operation, the notion of reoperation, multiple abscess, and finally the delay in starting treatment.

Adult↗