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Biomedical subjects

M Rinaldi

Publications and source records attributed to M Rinaldi.

At least 145 records · Page 8Linked to original sources
PubMed1996

[Lung transplantation in Pavia. Clinical experience].

Single and bilateral lung transplantation represents the most recent success in the field of organ replacement. The procedure underwent a very long period of laboratory and clinical experimentation and it is still a high-risk procedure to be performed by a few highly specialized centers. At our Department of Cardiac Surgery, the preliminary experience in lung replacement was obtained by clinically applying heart-lung transplantation in patients with both vascular and parenchymal lung disease during 1991. In the following years, the indications for isolated lung transplantation were enlarged by some centers with good results; this consideration, together with the scarce availability of integral heart-lung blocks, led us to use single and bilateral lung transplantation initially for parenchymal disease and subsequently also for vascular disease. Since February 1992, 12 single lung transplantations and 12 bilateral lung transplantations have been performed at our Center. In this report the selection criteria, the preoperative characteristics and the perioperative variables of donors and recipients are discussed. Particular emphasis is given to immunosuppression treatment, diagnosis of rejection and airways suture complications. The conclusions summarize the present indications for the different types of lung transplantations according to the different preoperative diagnosis.

Adolescent↗
PubMed1996

Activation of cytotoxic and natural killer T-cell system in patients with hepatocellular carcinoma and cirrhosis.

The immune response in liver cirrhosis and hepatocellular carcinoma is receiving renewed attention in consideration of the possible treatment with biological response modifiers. The aim of this study was to evaluate whether cirrhosis and hepatocellular carcinoma induce any modification in peripheral lymphocyte subsets. Lymphocytes were evaluated (number/percentage) in 61 patients with hepatocellular carcinoma, 35 with cirrhosis and 24 healthy controls. Using flow cytometry, 10 lymphocyte subpopulations were assayed, plus the CD4/CD8 ratio. Results demonstrated no change in the number of lymphocytes; cirrhosis and hepatocellular carcinoma patients had significantly more HLA-DR+ (p = 0.001) and CD3+/HLA-DR+ (activated T) (p = 0.002) and fewer CD3+ (mature T) (p = 0.02) cell than controls; hepatocellular carcinoma patients had significantly more CD3+/CD56+/CD16- (cytotoxic non-MHC restricted T cells) and CD25+ (IL-2 receptor positive cells). If the percentages of all cells with cytotoxic-T activity were pooled, a significant increase (p = 0.03) was seen in hepatocellular carcinoma patients. In conclusion, in contrast to previous data, hepatocellular carcinoma patients reveal an increased number of cytotoxic non-MHC restricted T cells.

Antigens, CD↗
PubMed1996

[Cardiomyoplasty. Critical review of experimental and clinical results].

Cardiomyoplasty (CMP) is a surgical therapy for dilated cardiomyopathy. In this procedure the "latissimus dorsi" is wrapped around the heart and chronically paced synchronously with ventricular systole. CMP has been performed in more than 500 cases worldwide, 42 cases in Italy, with variable degrees of success. Despite symptomatic improvement in the majority of patients surviving the procedure, objective hemodynamic effects have not been consistently demonstrated. The hemodynamic effect of CMP has been the subject of a great deal of experimental and clinical research over the past decade. This article discusses in detail the published results of experimental and clinical cardiomyoplasty, with particular emphasis on hemodynamic effects and limitations of the procedure.

Animals↗
PubMed1995

Demonstrable cardiac reinnervation after human heart transplantation by carotid baroreflex modulation of RR interval.

BACKGROUND: After heart transplantation, respiration-synchronous fluctuations (0.18 to 0.35 Hz, high frequency [HF]) in RR interval may result from atrial stretch caused by changes in venous return, but slower fluctuations (0.03 to 0.15 Hz, low frequency [LF]) not due to respiration suggest reinnervation. In normal subjects, sinusoidal neck suction selectively stimulates carotid baroreceptors and causes reflex oscillations of RR interval. METHODS AND RESULTS: To evaluate the presence of reinnervation, we measured the power of RR-LF and RR-HF in 26 heart transplant recipients and 16 control subjects before and during sinusoidal neck suction at 0.1 Hz and 0.20 Hz (similar to but distinct from that of controlled respiration, 0.25 Hz) and before and during administration of atropine or beta-blocker (esmolol hydrochloride) by spectral analysis. All transplant recipients showed small respiratory HF fluctuations. Nonrespiratory LF fluctuations were present in 13 of 26 transplant recipients and increased with months since transplantation (r = .53, P < .01). HF neck suction induced a 0.20-Hz component in all 16 control subjects and none of the 26 transplant subjects. LF neck suction increased RR-LF (from 0.73 +/- 0.20 to 1.30 +/- 0.26 ln ms2, P < .001), similar to but less than in control subjects (from 6.12 +/- 0.21 to 8.27 +/- 0.21 ln ms2, P < .001). Atropine reduced all fluctuations in control subjects and blocked the HF increase caused by 0.20-Hz neck suction but not the LF increase during 0.10-Hz stimulation. Neck suction-induced changes in LF fluctuations persisted after administration of atropine in transplant recipients but were attenuated by esmolol hydrochloride, suggesting sympathetic rather than vagal reinnervation. CONCLUSIONS: The presence of baroreceptor-induced RR oscillations is evidence of functional, although incomplete, autonomic reinnervation.

Adrenergic beta-Antagonists↗
PubMed1995

Stability and functional effectiveness of phosphorothioate modified duplex DNA and synthetic 'mini-genes'.

Several gene transfer techniques that employ 'naked DNA' molecules have recently been developed and numerous gene therapy protocols that make use of 'naked-DNA' have been proposed. We studied the possibility of enhancing the stability of 'naked DNA vectors' and thus also gene transfer and expression efficiencies, by constructing phosphorothioate (PS-) double strand DNA molecules and functional transcription units. We first synthesized short PS-double strand DNA molecules by the annealing of two complementary, 35 nt long, oligonucleotides. The accessibility of DNA modifying enzymes to this molecule was significantly decreased: T4-ligase and kinase activity were respectively reduced up to 1/2 and to 1/6, as compared to the normal phosphodiester molecule. Nucleolytic stability was increased either to purified enzymes (DNase I and Bal31) or to incubations in fresh serum, cell culture medium or in muscle protein extract. Phosphorothioate end-capped complete eukaryotic transcription units (obtained by Taq polymerase amplification with PS-primers) were not significantly protected from nucleolytic attack. On the contrary, synthetic transcription units, 'mini genes', obtained by Taq amplification with 1, 2 or 3 PS-dNTP substitutions, were resistant to DNase I and Bal31 nucleolytic activity. Transcription efficiency, driven by the T7 promoter, was 96.5, 95 and 33.5% (respectively with 1, 2 or 3 substitutions), as compared to the normal phosphodiester molecules.

Base Sequence↗
PubMed1995

Natural history of mitral valve prolapse.

To assess the rate and predictors of complications in patients with mitral valve prolapse (MVP), 316 subjects (mean age 42 +/- 15 years) with echocardiographic MVP were followed prospectively for a mean of 102 months: 220 (70%) were women, 225 (71%) had clinically recognized MVP, and 91 (29%) were detected in family studies. During follow-up, 11 patients (0.4/100 subject-years) required mitral valve surgery, 6 died of cardiac causes (0.2/100 subject-years), 7 developed cerebral ischemia (0.3/100 subject-years), and 2 developed active infective endocarditis (0.1/100 subject-years). The overall rate of fatal and nonfatal complications (1/100 patient-years) was higher in men than in women (odds ratio [OR] 3.2, p < 0.003), in subjects aged > 45 than < or = 45 years (OR 3.4, p = 0.002), in clinically recognized patients than in affected family members (OR 3.8, p < 0.02), and in those with a holosystolic murmur (OR 26.9, p < 0.00005); the overall rate was lower in those with a midsystolic click (OR 0.3, p < 0.002). Echocardiographic left ventricular or atrial diameter > or = 6.0 or > or = 4.0 cm, respectively, was associated with a 16.7- and 15.1-fold higher likelihood, respectively, of subsequent complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Successful treatment of aortic dissection after heterotopic heart transplantation.

Heterotopic heart transplantation is a valid option when there is a large donor-recipient size mismatch. However, the presence of the diseased native heart can jeopardize the medium-term and long-term outcome. The problems stemming from this most commonly described in the literature are thromboembolism, angina, and arrhythmias. In this report, we describe the case of a type A aortic dissection in the native aorta that occurred 30 months after heterotopic heart transplantation and the surgical technique successfully applied for its repair. We also discuss some of the alternative techniques.

Aortic Dissection↗
PubMed1995

Long-term effects of Enterococcus faecium SF68 versus lactulose in the treatment of patients with cirrhosis and grade 1-2 hepatic encephalopathy.

In 40 patients with cirrhosis on a dietary protein regimen of 1 g/kg b.w., we determined the effect on chronic hepatic encephalopathy of long-term administration of Enterococcus faecium (SF68) versus lactulose. The patients received one of the two treatments for three periods of 4 weeks, each separated by drug-free 2-week intervals. The efficacy of treatment was assessed by arterial blood ammonia concentration, mental status, number connection (Reitan's part A) test and flash-evoked visual potentials. At the end of the third period the reduction in both blood ammonia concentrations and Reitan's test times was more enhanced in patients on SF68 than in patients on lactulose. Furthermore, while patients on lactulose tended to return to basal values during drug-free intervals, responders in the SF68 group maintained improvement throughout the study. In conclusion, SF68 is at least as useful as lactulose for the chronic treatment of chronic hepatic encephalopathy; it has no adverse effects, and treatment can be interrupted for 2 weeks without losing the beneficial effects.

Adult↗
PubMed1995

Management of anesthesia during dynamic cardiomyoplasty.

STUDY OBJECTIVE: To review experience with anesthetic management in ten patients undergoing dynamic cardiomyoplasty (CMPL), a new surgical technique that serves as an alternative to heart transplantation. DESIGN: Retrospective clinical study. SETTING: Cardiothoracic operating room at a university hospital. PATIENTS: Ten male functional New York Heart Association (NYHA) class III and IV patients, aged 39 to 60 years, awaiting heart transplantation, 7 of whom were diagnosed with dilated cardiomyopathy, 3 with postischemic cardiomyopathy. INTERVENTIONS: Under general anesthesia, the latissimus dorsi muscle was harvested and rotated into the chest through a window in the second rib. The muscle was then wrapped around the heart. Starting from the second postoperative week, the latissimus dorsi was stimulated to provide assistance to a failing heart. MEASUREMENTS AND MAIN RESULTS: The mean left ventricular ejection fraction (LVEF) of the 10 patients was 24.89% +/- 9.17% (range 10% to 37%). No intraoperative death occurred. Two patients died of multiple organ failure and an apparent arrhythmia on the 15th and 25th postoperative days, respectively. The rest of the patients regained good working capacity postoperatively, as evidenced by improvement in NYHA grade. Nevertheless, the LVEF improved in only one patient. No significant differences were evident between preoperative and postoperative blood values, hemodynamic data, or spirometry. CONCLUSIONS: Dynamic CMPL is a considerable challenge for the anesthesiologist because these patients have poor cardiac reserve preoperatively and do not benefit from the procedure in the first two postoperative weeks. To date, CMPL seems to be an important alternative to heart transplantation because experience has shown an improvement in the quality of life with low intraoperative and postoperative complications.

Adult↗
PubMed1995

Different results of cardiac transplantation in patients with ischemic and dilated cardiomyopathy.

We retrospectively analyzed 275 consecutive transplanted patients, dividing them into group A (128 patients) affected by ischemic cardiomyopathy and group B (147 patients) affected by dilated cardiomyopathy. The difference in demographic, clinical and hemodynamic preoperative and postoperative data between the groups was studied; group A patients presented at transplantation with a less compromised hemodynamic picture, requiring inotrope infusion and mechanical assistance less frequently. The influence of etiology on early postoperative complications was also analyzed: group A patients needed postoperative mechanical assistance, inotrope, infusion and prolonged mechanical ventilation more often, therefore requiring a longer stay in the intensive care unit (ICU). Hospital mortality was twice as high in group A. The older age of group A patients per se did not influence these results significantly. The long-term follow-up was then studied with particular attention to parenchymal functions, hemodynamics, coronary artery disease, metabolic and surgical complications, and survival. The complication rate was higher in group A, with more severe hypertension and higher cholesterol levels at 1 year, a higher prevalence of accelerated coronary artery disease (CAD) and a more frequent onset of insulin-dependent diabetes. Surgical and vascular complications were also more frequent. The final result was a better 5-year actuarial survival rate for group B patients. Donor and recipient ages at the time of transplant did not influence this result. We conclude that ischemic patients, even if they are transplanted in better condition and operated more electively, have a more critical early and long-term postoperative course and a worse survival rate. These findings are not explained by advanced age, but could be due to the impact of atherosclerosis and metabolic impairments associated with ischemic disease.

Actuarial Analysis↗
PubMed1995

Comparative and collaborative evaluation of standardization of antifungal susceptibility testing for filamentous fungi.

The purpose of the study was to evaluate the interlaboratory agreement of broth dilution susceptibility methods for five species of conidium-forming (size range, 2 to 7 microns) filamentous fungi. The methods used included both macro- and microdilution methods that were adaptations of the proposed reference method of the National Committee for Clinical Laboratory Standards for yeasts (m27-P). The MICs of amphotericin B, fluconazole, itraconazole, miconazole, and ketoconazole were determined in six centers by both macro- and microdilution tests for 25 isolates of Aspergillus flavus, Aspergillus fumigatus, Pseudallescheria boydii, Rhizopus arrhizus, and Sporothrix schenckii. All isolates produced clearly detectable growth within 1 to 4 days at 35 degrees C in the RPMI 1640 medium. Colony counts of 0.4 x 10(6) to 3.3 x 10(6) CFU/ml (mean, 1.4 x 10(6) CFU/ml) were demonstrated in 90% of the 148 inoculum preparations. Overall, good intralaboratory agreement was demonstrated with amphotericin B, fluconazole, and ketoconazole MICs (90 to 97%). The agreement was lower with itraconazole MICs (59 to 79% median). Interlaboratory reproducibility demonstrated similar results: 90 to 100% agreement with amphotericin B, fluconazole, miconazole, and ketoconazole MICs and 59 to 91% with itraconazole MICs. Among the species tested, the MICs for S. schenckii showed the highest variability. The results of the study imply that it may be possible to develop a reference method for antifungal susceptibility testing of filamentous fungi.

Aspergillus↗
PubMed1994

Accumulation of human apolipoprotein-E in rat plasma after in vivo intramuscular injection of naked DNA.

Naked DNA was found to be incorporated and consistently expressed after in vivo direct injection into striated muscle. In addition to the local expression of muscle-related or exogenous proteins, intramuscular direct gene transfer may be a useful tool to deliver recombinant proteins into the blood stream. However, no direct demonstration of recombinant protein secretion from muscle to the circulation has been reported thus far. We have injected a naked plasmid DNA containing the human receptor-binding defective apo-E2 cDNA, under the control of CMV promoter, into the quadriceps of Yoshida rats, affected by hereditary hypercholesterolemia and altered LDL-receptor activity. Plasma accumulation of human apo-E2 was demonstrated for at least 45 days after injection. On the contrary, the expression of the normal human apo-E3, injected into the muscle of normal Wistar rats, was demonstrated only in the area of muscular injection and not in the blood plasma. Endogenous rat apo-E expression was not affected by the exogenous human apo-E2 production. Our results demonstrate the availability of intramuscular direct gene transfer as a safe and simple method for the chronic systemic delivery of recombinant proteins to the circulation, although further improvements are needed in order to enhance the efficiency and stability of expression.

Animals↗
PubMed1994

ArF 193 nm excimer laser corneal surgery as a possible risk factor in cataractogenesis.

It was evaluated whether ArF 193 nm excimer laser corneal surgery represents a risk factor in cataractogenesis. For this purpose, 20 male albino rabbits underwent a photorefractive keratectomy and biochemical analyses on aqueous humour (hydrogen peroxide, ascorbic acid, and reduced and oxidized glutathione) and on lens (malondialdehyde, reduced and oxidized glutathione) were performed. In the aqueous humour of all treated animals a significant increase in hydrogen peroxide and in oxidized glutathione and a concomitant decrease in ascorbic acid and reduced glutathione concentration were observed. Moreover, all these variations were significantly correlated with the cumulative UV dose used. In the lens, after excimer laser corneal surgery, there was a dramatic loss of reduced glutathione and a parallel increase in oxidized glutathione levels. Malondialdehyde concentration was also increased, but only at the highest UV exposure. Moreover, all these variations were significantly correlated with the cumulative UV dose used. These findings demonstrate that the exposure of aqueous humour and lens to the secondary radiation generated after ArF 193 nm excimer laser corneal photoablative keratectomy induces biochemical modifications which are known to be markers of cataractogenesis.

Animals↗
PubMed1994

Non-respiratory components of heart rate variability in heart transplant recipients: evidence of autonomic reinnervation?

1. Although the high-frequency fluctuations in R-R interval (respiratory sinus arrhythmia) observed in heart transplant recipients are not a reliable marker of reinnervation because of a previously shown direct mechanical effect of breathing, the presence of a non-respiration-related low-frequency oscillation reflects rhythms generated outside the heart, and thus could be neurally mediated. 2. To evaluate the presence of reinnervation, the spontaneous variability in R-R interval was investigated, supine and after passive tilting, in 23 heart transplant recipients (age 43 years, range 23-64 years) and in 25 normotensive control subjects by autoregressive spectral analysis of low- and high-frequency spontaneous fluctuations in R-R interval and respiration. The response of R-R interval to amyl nitrite inhalation was also evaluated in five heart transplant recipients and eight control subjects. 3. Detectable low-frequency oscillations, unrelated to respiration, were present in 13/23 heart transplant recipients, particularly in those who were transplanted at least 20 months earlier (11/14). The natural logarithm of the power of low-frequency fluctuations was markedly lower than in control subjects (0.75 +/- 0.21 versus 5.62 +/- 0.20 ms2, P < 0.001). The low-frequency but not the high-frequency fluctuations correlated with time since transplantation (r = 0.44, P < 0.05). The subjects with low-frequency fluctuations showed a sudden decrease in R-R interval with amyl nitrite linearly related to the decrease in mean blood pressure (r > or = 0.94). The slopes obtained in these heart transplant recipients were comparable (although of lower values) with those obtained in control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Resistance of Candida albicans to fluconazole during treatment of oropharyngeal candidiasis in a patient with AIDS: documentation by in vitro susceptibility testing and DNA subtype analysis.

We describe a patient with recurrent episodes of oropharyngeal candidiasis who required progressively higher doses of fluconazole to control and infection. The patient was treated for 14 infections over a 2-year period with doses of fluconazole that ranged from 100 to 800 mg per day. Clinical response, two methods of in vitro susceptibility testing, and molecular epidemiologic techniques were evaluated for 12 of the 14 episodes. Ultimately, the patient became unresponsive clinically to a dose of 800 mg of fluconazole per day. In vitro susceptibility testing of isolates obtained during these successive episodes of infection revealed the development of resistance to fluconazole, and molecular epidemiologic techniques confirmed the persistence of the same Candida albicans strain throughout all 12 episodes.

AIDS-Related Opportunistic Infections↗