Biomedical subjects
Publications and source records attributed to R Neri.
A case of reflex sympathetic dystrophy syndrome (RSDS) in a patient with osteogenesis imperfecta (OI) is reported. We discuss the association of OI, manifested by microfractures of the trabecular bone due to marked bone fragility, and the appearance of RSDS. Magnetic resonance imaging (MRI) was helpful in assessing the presence and extent of the trabecular fractures.
To evaluate functional alterations of mesangial cells induced by diabetes (DMC), we observed the changes of cytosolic calcium ([Ca]i) in response to the vasoconstrictor agonists angiotensin II (Ang II) and norepinephrine (NOR). DMC were obtained from rats with streptozotocin-induced diabetes, cultured in normal medium and identified as mesangial cells (MC) in the third subculture. [Ca]i was measured using fura-2 as a fluorophore. Basal calcium levels (60 to 80 nM) in DMC were not different from control mesangial cells (CMC). The high glucose (30 mM) medium concentration reduced the response of CMC and DMC to Ang II and NOR. This was not an osmotic effect since mannitol did not alter these responses. When DMC were stimulated with Ang II, a desensitized response was always observed, with a transient variation of [Ca]i (N = 6, P < 0.05). In contrast, a non-desensitized response with a sustained pattern of [Ca]i increases was obtained in NOR-stimulated DMC. Therefore, the present results suggest that DMC show a modified response to stimulation of the Ang II receptor, which is expressed phenotypically in culture by desensitization. Furthermore, these alterations induced by diabetes environment in MC in vivo were maintained in vitro despite a long period (approximately 5 months) in which the cells were grown in normal culture medium.
Transvenous internal cardioversion of chronic AF using a right atrium (RA) coronary sinus (CS) vector requires more energy than cardioversion of paroxysmal AF. Chronic AF is not terminated in 25% of patients using biphasic shocks up to 10 J. We therefore evaluated efficacy, safety, and tolerability of internal cardioversion using a "unipolar" configuration (RA to skin patch) and biphasic shocks in patients with long-lasting AF and different heart disease. In each patient, biphasic R wave synchronous shocks were delivered between a large defibrillating surface area electrode in the RA and a skin patch in the left prepectoral position. Defibrillation protocol started with a test shock of 0.4 J. Shocks were repeated and increased until termination of AF or a maximum of 34 J. Sedation was used when the patient described the shock as painful. This study included 11 patients with a mean age of 67 +/- 8 years (range 56-83). AF duration was > or = 1 month in all patients with a mean duration of 11 +/- 11 months (range 2-36). Underlying heart disease was present in all patients and the mean left atrial dimension was 43 +/- 9 mm (range 26-57). AF was terminated in 10 of 11 patients (91%) with a mean delivered energy of the successful shocks of 18.7 +/- 8.7 J (median energy 16.9 J; range 7.3-32.5) and a mean leading edge voltage of 564 +/- 129 V. The mean shock impedance at the defibrillation threshold was 71 +/- 13 omega (range 59-103). A total of 131 shocks were delivered without any complication and proarrhythmia episodes. We conclude that low energy "unipolar" internal cardioversion is a simple, safe, and effective technique for termination of chronic AF in patients with heart disease. The procedure is often tolerated under light sedation.
In this study, we review research conducted in the La Spezia district during 1989, 1992, and 1994, using lichens and moss as indicators of air pollution. SO2 pollution was examined by means of an Index of Atmospheric Purity (IAP) based on the frequency of epiphytic lichen within a sampling grid. Metal deposits were estimated using the lichen Parmelia caperata and the moss Hypnum cupressiforme as bioaccumulators. IAP maps show progressive air quality improvement from 1989 to 1994. This trend correlates to a decrease in SO2 emissions during recent years that is attributed to the use of methane for residential heating and the closing of a coal-fired power plant. Metal contamination maps show that the most polluted area is now in the southeastern part of the gulf. The pattern of pollution coincides with the location of the chief pollution sources in the area. From 1989 to 1994, the metal concentrations in lichens decreased, but metal deposits in the southeastern area were cause for concern. High concentrations of lead in the area are related to emissions from a waste incinerator and a plant that produces lead oxide. Epidemiological investigations reveal that the area population has the highest levels of lead in their blood. The use of bioindicators and bioaccumulators permits long-term and large-scale monitoring of environmental pollutant levels in full agreement with traditional methods.
Hemodynamic changes induced by ventriculo-atrial retroconduction has been considered an important factor in pacemaker syndrome. The contraction of atrial muscles, when the mitral valve is closed, induces a reverse systolic flow into the pulmonary veins, because the outlet of the pulmonary vein in the left atrium is not protected by a valve. The profile of the pulmonary vein forward flow of 25 patients was examined using transesophageal echocardiography (TEE) technique. Doppler evaluation of velocity-time integrals of forward flow (fVTI) and reverse flow (rVTI) was measured both during sinus rhythm or fully automatic (DDD) pacing, and ventricular demand pacing (VVI) accompanied by ventriculoatrial (VA) retroconduction or atrioventricular (AV) dissociation. The mean fVTI was reduced from 21.1 cm +/- 6.2 cm in DDD or sinus rhythm (SR) to 16.4 cm +/- 6.6 cm in VVI (p < 0.001). The mean rVTI was increased from 1.4 cm +/- 0.8 cm in DDD or SR to 4.3 cm +/- 1.8 cm in VVI (p < 0.001). The degree of such alterations varied considerably from patient to patient and this may explain the variability of clinical symptoms reported for pacemaker syndrome. It has not been possible to establish a direct correlation between the magnitude of hemodynamic changes and the severity of the symptoms observed because all the patients were in sequential stimulation or in SR and were temporarily submitted to VVI stimulation during the echocardiographic examination.
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BACKGROUND: Platelet-activating factor is a mediator of inflammation involved in the blood-membrane interaction. We report that selective stimulation of complement receptors (CR1 and CR3) triggers PAF synthesis and monocyte adherence to complement-activating membranes. METHODS: The synthesis of PAF was studied after stimulation of normal human adherent monocytes with F(ab)2 and Fab fragments of monoclonal antibodies specific to CR1 and CR3. CD11a, CD11b, CD18, and CD35 was studied by flow cytometry on neutrophils and monocytes. The molecular species of PAF from stimulated monocytes were identified by reverse-phase high-performance liquid chromatography coupled with mass spectrometry. RESULTS: Anti-CR1 and anti-CR3 monoclonal antibodies induced a dose-dependent C-16 but not C-18 PAF production. The latter occurred also with monovalent Fab fragments of both anti-CR1 and anti-CR3 monoclonal antibodies, that were not internalized as seen by immunofluorescence. Adherence of monocytes to Cuprophan membranes was markedly higher (P < 0.01) in membranes pretreated with fresh than with heat-inactivated normal plasma. However, the high adherence to fresh plasma-treated membranes was completely abrogated by coincubating the cells with Web 2170, a specific PAF receptor antagonist. This was not due to downregulation of adhesion molecules expression on leukocytes. CONCLUSIONS: These studies implicate a crucial role of PAF in blood interaction with haemodialysis membranes that fix complement activated products.
The 90-kDa nucleolus organizer region autoantigen (NOR-90) was previously shown to be identical to the human upstream binding factor (hUBF) and composed of two Mr forms. In this study, thirteen human anti-NOR-90/hUBF autoimmune sera were used to further characterize NOR-90/hUBF and its associated autoantigens. Nucleolar and nucleoplasmic staining of interphase cells and NOR staining in mitosis were observed with all sera by immunofluorescence. All sera showed equal reactivity with both high and low Mr forms in Western blotting and immunoprecipitation, suggesting that the cellular content and distribution for both Mr forms were approximately equal. Using extracts of [35S]methionine- and [32P]orthophosphate-labeled cells, phosphorylated and nonphosphorylated NOR-90/hUBF were identified for both Mr forms and these two populations were recognized by human autoantibodies. In immunoprecipitation analyses, the nonphosphorylated population was readily extracted while the phosphorylated population was tightly bound. Clinical data were available for 8 patients in whom anti-NOR-90/hUBF autoantibodies were present. They had diverse diagnoses including SLE, rheumatoid arthritis and malignancies. Although only one patient was diagnosed as scleroderma, Raynaud's phenomenon was observed in 4 of the 8 patients. Interestingly, one NOR-90/hUBF serum was shown to contain additional antibodies to RNA polymerases I and II.
Bicarbonate-based dialysate solutions support the rapid growth of bacteria. The long-term (360-h) efficacy of ultrafiltration by two polysulphone ultrafilters in removing not only endotoxin but also the cytokine(IL-1, TNF)-inducing capacity was evaluated using an experimental circuit contaminated with Pseudomonas aeruginosa filtrates. One of the polysulphone ultrafilters was submitted to a standard sanitization procedure every 12 h (hypochlorite 1.2% solution for 5 min and rinsing for 20 min). Endotoxin was detected by the kinetic quantitative chromogenic limulus amoebocyte lysate (LAL) assay. Immunoreactive IL-1 and TNF were evaluated in the lysates of peripheral blood mononuclear cells containing 5 x 10(5) human monocytes. The results of the present studies show that although LAL-reactive bacterial products were significantly removed in post-ultrafilter samples, they remained detectable, albeit below the upper limit accepted by the present European pharmacopeias (< 0.125 EU/ml). The removal of cytokine-inducing capacity was time-dependent and correlated with time of use in the case of the sanitized ultrafilter. Beyond the time of use, two other factors emerged as possibly capable of reducing the efficacy of the ultrafilter in removing LAL-reactive bacterial components, namely the pressure and the cytokine-inducing activity in pre-ultrafilter samples. Preincubation with polymyxin B, an agent that irreversibly binds lipid A and blocks lipid A-induced biological activities, did not abrogate the cytokine-inducing capacity in all post-ultrafilter samples; this suggests that either low-molecular-weight endotoxin subunits or lipid A-unrelated components may be responsible for the residual biological activity in post-ultrafilter samples.(ABSTRACT TRUNCATED AT 250 WORDS)
In the present work we report data on the specificity of antinuclear antibodies (ANA) in a large series of Italian patients suffering from a broad spectrum of connective tissue diseases (CTD), by using a series of homogeneous and validated techniques. The present study confirms, on the one hand, generally accepted concepts, i.e. that certain autoantibodies are strictly associated to certain disease states (such as anti-PCNA and anti-Sm in systemic lupus erythematosus, Jo 1 in polymyositis, and ACA and Scl-70 in scleroderma); the presence of 'marker' antibodies is, however, restricted to a relative minority of CTD patients. The application of a new methodological approach that considers the entire profile of ANA can greatly augment their diagnostic relevance and may provide useful indications for their interpretation, allowing us to establish for the first time the diagnostic usefulness not only of marker autoantibodies but also of certain associations between non-marker autoantibodies. Finally, the application of a more appropriate and powerful statistical tool (multiple correspondence analysis) has further emphasized the clear relationship existing between antibody specificities and certain disease states.
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The relevance of the extent of skin sclerosis and of other clinicoserological features in diagnosis, severity and prognosis of disease was studied in a large number of unselected patients with systemic sclerosis (SSc). One hundred and fifty-one patients with SSc (126 F and 25 M, mean age 48 +/- 14 SD) followed for 5.3 +/- 3.2 years were included. Patients were divided into 3 cutaneous subsets: limited (68), intermediate (46) and diffuse SSc (37). Serological markers were detected in 288 patients with Raynaud's phenomenon and other connective tissue diseases (CTD). Limited and intermediate SSC prevailed in female patients while the diffuse subset was more frequent in males (p less than 0.0001). Duration of Raynaud's phenomenon before disease onset was shorter in the diffuse variant (p less than 0.0001). A wider cutaneous involvement was associated with more severe forms of SSc. Diffuse subset showed the poorest prognosis at 10 years of followup compared with intermediate (p less than 0.05) and limited variant (p less than 0.001). Intermediate SSc seems a distinct variant of SSc on the basis of clinical manifestations and survival. Among serological markers, anticentromere, anti-Scl-70 and antinucleolar antibodies were found in 21, 40 and 27% of the cases, respectively; these were statistically less frequent (p less than 0.0001) in other CTD. In 83.5% of patients with SSc at least one of these specific markers was recorded. Anticentromere antibodies were correlated to sex (female), limited SSc, calcinosis and telangiectasia. On the contrary anti-Scl-70 was associated with diffuse and intermediate subsets and with more severe SSc manifestations.(ABSTRACT TRUNCATED AT 250 WORDS)
The authors describe the color flow pattern in a patient with right ventricle myxoma and outflow obstruction. A systolic eccentric mosaic color jet, flowing in a thin space between the tumor and the right ventricle outlet wall, was observed. The color Doppler imaging easily detected flow abnormalities, greatly simplified the correct alignment of continuous wave Doppler beam in the estimation of the pressure gradient and allowed a good evaluation of tumor hemodynamic effects.
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The accuracy of a real-time analysis Holter system (Oxford Medilog 4500) in detecting ventricular and supraventricular arrhythmias was evaluated. Hand-counted data from randomly selected hours of 152 ECG monitorings of 152 patients were used as the control standard. Accuracy of the system was evaluated on 606 hours for premature ventricular complexes (PVC), PVC couplets and supraventricular extrasystoles (SVE), and on 1,789 hours for ventricular tachycardia (VT), accelerated idioventricular rhythm (AIVR), and supraventricular tachycardia (SVT). Sensitivity and positive predictive accuracy for the Oxford system were (1) 92.9% and 94.9% for PVC; (2) 90.1% and 87.8% for PVC couplets; (3) 98.1% and 56% for AIVR; (4) 80% and 82.3% for VT; (5) 88.6% and 56.5% for SVE, and (6) 43.7% and 60.2% for SVT. Furthermore, negative predictive accuracy, the ability to predict the total absence of an arrhythmic event in an hour, was determined. It was 91.7% for PVC, 99.5% for PVC couplets, 99.9% for AIVR, 99.7% for VT, 95% for SVE, and 98% for SVT. ventricular arrhythmias, whereas significant inaccuracies appear to exist in the analysis of supraventricular arrhythmias.
Following a broad review of the literature referring to the histopathological clinical, immunological and immunogenetic characteristics of a particular variety of recently identified cutaneous lupus erythematosus, namely subacute lupus erythematous, the results of immunopathological studies in 11 patients (6 of whom presented the ring polycyclic variety and 5 the psoriasiform variety) are reported. Serum and skin samples were compared in both varieties and it was noted that there is: 1) a more marked incidence of hypocomplementemia and the presence of immune circulating complexes in the ring-polycyclic variety; 2) a more frequent demonstration of IgG and C at the dermo-epidermic junction and on the edge of superficial derma vessels in the same variety. These findings are interpreted as being the consequence of a more frequent and severe systemic (and above all renal) impairment in the ring-polycyclic variety.
In the present study, Ro/SS-A antigen has been isolated from human spleen by a two-step procedure. In the first step most of the non-antigenic material was removed by means of ammonium sulphate precipitation and ion exchange chromatography. The final purification was obtained by passing the Ro/SS-A-containing fractions twice through a Mono Q ion exchange fast protein liquid chromatography (FPLC) column. The purified antigen showed identical immunoreactivity with crude material on CIE and was composed of two polypeptides with a molecular weight of approximately 60,000 and 55,000 respectively on SDS-PAGE, both reacting on Western blotting with a panel of anti-Ro/SS-A antisera. This system permits milligrams of highly purified antigen to be obtained from grams of human spleen.
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