Search PubMed⌕ Search

Biomedical subjects

M Rossetti

Publications and source records attributed to M Rossetti.

At least 37 records · Page 2Linked to original sources
PubMed1998

Robotic automation of coagulation analysis.

Laboratory automation systems (LAS) have been installed in over 22 sites across North America providing automation of many preanalytical and analytical tasks in clinical laboratories. Only a few laboratories have automated the analysis of citrated whole blood for the diagnosis of hemostasis disorders. The analysis of coagulation factors in citrated blood requires a large amount of labor in order to provide rapid turnaround; thus automation of this analytical process is attractive. Therefore, we have created an automated coagulation workstation using a systematic approach to automation design and engineering. First, we used discrete event simulation to calculate potential throughput and to identify possible bottlenecks for the proposed coagulation workcell. We then created a three-dimensional animated computer model of the workstation to simplify workstation design. Finally, we constructed a prototype workcell using a mobile robot, an articulated robotic arm, and a coagulation analytical system.

Blood Coagulation Disorders↗
PubMed1998

Role of surgical techniques and operative findings in cranial and cervical nerve injuries during carotid endarterectomy.

OBJECTIVE: To establish the incidence of cranial and cervical nerve injuries during CEA and their relationship to different surgical techniques and operative findings. DESIGN: A prospective study. PATIENTS AND METHODS: From January 1994 to April 1995, 187 consecutive patients undergoing 190 CEAs were evaluated. Pre- and postoperative cranial and cervical nerve assessments were carried out by a single otolaryngologist, blinded to the operative technique and findings. Deficits lasting more than 12 months were defined as permanent. Logistic regression analysis was performed to evaluate the influence of surgical technique, type of anaesthesia, neck haematoma, and plaque extension on the onset of nerve injuries. RESULTS: Postoperatively, nerve lesions were identified in 51 CEAs (27%) and non-neurological injuries (hemilaryngeal ecchymosis or oedema) causing postoperative dysphonia were present in 80 CEAs (42%). All non-neurological injuries were transient and 98% disappeared within 1 month of surgery. Thirteen (7%) nerve lesions were permanent, but none were disabling. Vagus nerve lesions were significantly associated with long (> 2 cm) carotid plaque (OR = 3.5; CI 1.09-12.37; p = 0.03). Cervical branch lesions were associated with the presence of neck haematoma (OR = 1.9; CI 0.7-4.7; p = 0.05). The incidence of single cranial nerve injuries was higher in patch (OR = 2.7) and eversion (OR = 1.9) procedures than in primary closure. Multiple deficits (2 or more) were most frequent in eversion CEAs (OR = 2.8) and in cases complicated by neck haematoma (OR = 3.8). CONCLUSIONS: Cranial and cervical nerve lesions during CEA are common. However, our data showed that the majority of local complications are related to transient hemilaryngeal ecchymosis or oedema and, when permanent, are neither clinically relevant nor disabling at 1 year of follow up. Carotid plaque extension and neck haematoma appear to increase the incidence of cranial and cervical nerve lesions during CEA.

Adult↗
PubMed1998

Effects of intravenous anesthetics on normal and passively sensitized human isolated airway smooth muscle.

BACKGROUND: General anesthetics may modify airway responsiveness. The authors investigated the effect of thiopental, propofol, and etomidate on airway smooth muscle. METHODS: Contraction experiments were done in human airway rings that were either normal or passively sensitized with asthmatic serum. The effect of propofol and etomidate was also studied on both [Ca2+]i increase measured by microspectrofluorimetry in isolated myocytes and isometric contraction in the rat trachea. RESULTS: In human bronchi, thiopental (10[-7] to 10[-4] M) induced a concentration-dependent contraction. Neither propofol nor etomidate altered baseline tone, but both anesthetics reduced histamine-induced contraction. In human immunologically sensitized isolated bronchi, propofol (3 x 10[-4] M) reduced histamine reactivity (deltaFmax in %) to a greater degree than in nonsensitized tissues (64.4 +/- 15.7% and 16.4 +/- 8.5%, respectively; n = 6, P < 0.05), whereas the effect of etomidate (10[-4] M) was similar in both types of tissue (24.1 +/- 6% and 22.3 +/- 15%, respectively, n = 6). In rat isolated tracheal myocytes, propofol (3 x 10[-4] M) and etomidate (10[-4] M) altered the [Ca2+]i signal in response to the depolarizing agent potassium chloride and the muscarinic agonist acetylcholine. Accordingly, the two anesthetics also reduced the mechanical response of rat tracheal rings to these agonists. CONCLUSIONS: Whereas thiopental contracts human isolated bronchi, propofol and etomidate reduce histamine-induced contraction in human isolated airway smooth muscle that were either not sensitized or passively sensitized with asthmatic serum. This effect involves inhibition of both electro- and pharmacomechanical coupling.

Anesthetics, Intravenous↗
PubMed1998

Complete analytical and diagnostic performances of the Abbott Cell Dyn 3500.

METHODS: The study reports the analytical and diagnostic performances of Cell Dyn 3500 (Abbott), an automated haematology analyser that provides the electrical impedance and the optical detection of total leukocyte and a five population leukocyte differential count. The evaluation of complete blood count and differential leukocyte count parameters was performed following the guidelines of the International Council for Standardization in Haematology and those of the National Committee for Clinical Laboratory Standards document H20-A. RESULTS: The CD 3500 demonstrated a good linearity, minimal carry-over, as well as acceptable levels of within and between-batch imprecision and stability. An excellent correlation between CD 3500 and the routine systems used in our laboratory (Technicon H*2 and Coulter STKS) was found for the major haematological indices, though agreement was not as good for MCHC. There was a good correlation between CD 3500 and manual reference differential method for neutrophils, lymphocytes, eosinophils and basophils, with the exception of monocytes. CONCLUSIONS: Regarding clinical sensitivity, the CD 3500 showed a high specificity to detect morphological abnormalities, but low sensitivity especially for the identification of immature granulocytes and nucleated red blood cells; if we overall evaluate any qualitative flags, we found an appreciable increase in sensitivity.

Autoanalysis↗
PubMed1997

Stem cell mobilization in normal donors.

We studied peripheral blood and apheresis samples from 39 consecutive normal donors who were parents or siblings of patients who received matched or mismatched bone marrow transplants using a combination of rhG-CSF-mobilized peripheral blood stem cells (PBSCs) and bone marrow (BM). BM was harvested from donors 1-7 days before starting rhG-CSF treatment: 12 micrograms/kg/day rhG-CSF was administered by continuous s.c. infusion for 4-7 days. Peripheral blood progenitor cells were harvested by leukapheresis using an automated continuous-flow blood cell separator, beginning on day 4 of rhG/CSF, for 1-4 consecutive days. Peak peripheral blood CD34+ cell and CFU-GM levels were reached simultaneously on day 5 or 6 of rhG-CSF administration. Median peak levels were 1.65% for CD34+ cells (range 0.34%-4.7%) and 142 CFU-GM/10(5) plated cells (range 16-700). The greatest numbers of CD34+ cells and CFU-GM, expressed per liter of blood volume processed, were harvested during the second and third leukapheresis: CD34+ cells 37.77 +/- 25.48 x 10(6) and CFU-GM 3.32 +/- 2.51 x 10(6) during the second leukapheresis, and CD34+ cells 37.01 +/- 16.33 x 10(6) and CFU-GM 3.82 +/- 4.36 x 10(6) during the third. The number of CD34+ cells and CFU-GM did not correlate with the sex, age, or body weight of the donors. This study indicates that this protocol for administration of rhG-CSF mobilizes large numbers of hematopoietic progenitor cells into the peripheral blood and that bone marrow harvesting before G-CSF administration does not impair stem cell mobilization.

Adult↗
PubMed1997

[Reactive metabolites of oxygen, lipid peroxidation, total antioxidant capacity and vitamin E in essential arterial hypertension].

Free radical oxidative stress has been implicated in the pathogenesis of a variety of human diseases. The purpose of this study was to explore the degree of oxidative stress in essential arterial hypertension (EAH). The study groups consisted of fifteen untreated EAH patients (WHO stages 1 and 2), aged 40 to 70 years, and fifteen, age and sex matched, normal controls. The levels of typical peroxidation products such as malondialdehyde and 4-hydroxyalkenals (with the LPO-586 test, Bioxytech), free radicals and other reactive oxygen metabolites (ROMs) (with the d-ROMs test, Diacron), vitamin E (with HPLC method) and total antioxidant capacity (with the TAS test, Randox) were determined in the plasma af all subjects. Compared to the control group EAH patients exhibited significantly higher ROMs levels (334.7 +/- 21.6 vs 249.2 +/- 23.3 Units, means values +/- S.E.M.), and of lipid peroxidation products (10.7 +/- 0.7 vs 8.09 +/- 0.9 nmol/ml). It must be noted that such increases were not observed in all EAH patients, but above all in those less young or with more severe hypertension. On the other hand no significant difference was found between EAH patients and normal controls as regards vitamin E concentration and total antioxidant capacity. These results suggest that EAH patients, in spite of their normal antioxidant defences, are more prone than normotensive subjects to oxidative stress because of an increased ROMs production. This could result in an inactivation of prostacyclin and NO, hence an enhancement of peripheral vascular resistance and an increase of hypertension. Another consequence might be an increased lipid peroxidation of low density lipoproteins, a condition which is known to be associated with accelerated atherosclerosis. The study of oxidant and antioxidant factors seems therefore useful in EAH patients in order to evaluate oxidative stress and to correct, if possible, the observed abnormalities with dietetic or pharmacologic therapy.

Adult↗
PubMed1996

[The 100th birthday of Rudolf Nissen].

Rudolf Nissen was born in Neisse, Schlesien, 9 September 1896. From 1921 to 1933 he was the favorite pupil of Ferdinand Sauerbruch in Munich and Berlin. 1930 he became professor of surgery at the Charité. The assumption of power by the Nazi-regime forced Nissen to resign his position and end his career in Germany. He took over the surgical chair in Istanbul, Turkey. Emigrating in 1939 to the USA, he held surgical positions in hospitals at New York and accepted in 1952 the chair of Surgery at the University of Basel, Switzerland. Nissen died in Riehen/ Basel on 22 January 1981. Nissen was a critical observant clinician, an efficient and popular physician, a teacher and a speaker. Of historical significance are pioneering works in thoracic surgery, the first successful pneumectomy in man, the classical works about the treatment of gastro-oesophageal reflux disease and hiatus hernia. The Nissen-Rossetti type of fundoplication has remained the standard procedure in Europe and the USA.

Fundoplication↗
PubMed1996

Effects of nitric oxide inhalation on pulmonary serial vascular resistances in ARDS.

The pulmonary vasculature site of action of nitric oxide (NO) in patients with acute respiratory distress syndrome (ARDS) is still unknown. Seven patients were studied during the early stage of ARDS. The bedside pulmonary artery single-occlusion technique, which allows estimation of the pulmonary capillary pressure (Pcap) and segmental pulmonary vascular resistance, was used without NO or with increasing inhaled NO concentrations (15 and 25 parts per million [ppm]). Systemic circulatory parameters remained unaltered during 15 ppm NO inhalation, whereas 25 ppm NO inhalation slightly decreased mean systemic arterial pressure from 76.7 +/- 5.1 (mean +/- SEM) to 69 +/- 5.2 mm Hg (p < 0.01). Mean pulmonary arterial pressure (Ppam) and mean pulmonary capillary pressure (Pcapm) fell during 25 ppm NO inhalation from 27.4 +/- 3.5 to 21 +/- 2.2 mm Hg (p < 0.001) and from 14.8 +/- 1.5 to 10.7 +/- 1.4 mm Hg (p < 0.001) respectively, the total pulmonary resistance decreased by 28% (p < 0.01). The resistance of the capillary-venous compartment fell during 25 ppm NO inhalation from 100 +/- 16 to 47 +/- 16 dyn x s x m(2) x cm(-5) (p < 0.01), whereas the pulmonary arterial resistance was unchanged. In these patients NO inhalation during the early stage of ARDS reduces selectively Ppam and Pcapm by decreasing the pulmonary capillary-venous resistance. This latter effect may reduce the filtration through the capillary bed and hence alveolar edema during ARDS.

Administration, Inhalation↗
PubMed1996

Diagnosing nasal hyperreactivity with positional rhinomanometry.

Positional rhinomanometry is a physiologic method for estimating nasal resistance, which is variable, difficult to predict, and linked to vasomotor activity of the functional system culminating in the turbinate valves. Thirty subjects suffering from allergic rhinitis, 25 patients affected by aspecific rhinitis, and 40 healthy controls underwent positional rhinomanometry. Test positions included the seated (baseline), supine, and recumbent (homolateral and contralateral to the nasal fossa under examination). In patients with perennial allergic rhinitis and in those with aspecific rhinitis, positional rhinomanometry elicited two pathologic responses: either an average percentage rise of more than 80% in nasal resistance in the supine and homolateral and contralateral recumbent positions compared with basal values, or a paradoxical fall in the supine and homolateral recumbent positions.

Adult↗
PubMed1995

Role of protein kinase C in nonsensitized and passively sensitized human isolated bronchial smooth muscle.

To examine the role of protein kinase C (PKC) activation in the control of the mechanical activity of human isolated bronchial smooth muscle obtained at thoracotomy, the effect of the phorbol ester phorbol 12,13-dibutyrate (PDB) was evaluated. PDB produced slowly developing and sustained contractions that were reduced 1) by the PKC inhibitor staurosporine and 2) after long-term (12 h) exposure to PDB, which downregulates PKC. Moreover, the inactive phorbol ester 4 alpha-phorbol 12,13 didecanoate had no contractile effect. Removal of external Ca2+ or addition of the Ca(2+)-channel antagonist verapamil reduced the PDB-induced contraction. Passive sensitization of human isolated bronchial rings, i.e., incubation overnight of tissues in serum from atopic asthmatic patients, decreased the maximal response to PDB to 28.9 +/- 8% of the maximal response to acetylcholine (ACh) when compared with that of paired nonsensitized rings, i.e., tissues incubated overnight in serum from normal subjects (46.7 +/- 9.4% of the maximal response to ACh, n = 5, P < 0.05). The decrease in the response to PDB induced by either long-term preexposure to PDB or passive sensitization was reversed when both types of tissues were allowed to recover unstimulated for 3 h before PDB application. These results show that 1) PKC activation induces maintained contractions in human isolated airway smooth muscle that are largely dependent on extracellular calcium; 2) passive sensitization alters the PKC-mediated response in a way similar to that induced by prolonged stimulation of PKC.

Alkaloids↗
PubMed1994

A new immunoassay for the measurement of myoglobin in serum.

Because the concentration of serum myoglobin (Mb) increases within 2 to 4 hours after the first sign of acute myocardial infarction, it has been proposed as an early marker of the condition. Our aim was to evaluate a new assay that provides a rapid, quantitative determination of Mb (Baxter Stratus Myoglobin) based on the radial partition technique. We compared the results obtained by this technique with those from nephelometric and radioimmunoassay methods. A significant agreement was observed, the correlation coefficients (r) being 0.999 and 0.996, respectively. The method evaluated provided good reproducibility with CVs between 3.14% and 4.87%, and its linearity and analytical sensitivity were satisfactory. The clinical evaluation of this assay demonstrates that Mb increases in serum of patients with acute myocardial infarction before total creatine kinase and creatine kinase MB isoenzyme. Mb concentration shows an early peak and earlier return to normal values after the necrosis compared to enzymatic activities. Moreover the assay is rapid and fully automated. The method is therefore considered appropriate for contributing to the early diagnosis of AMI in clinical laboratories.

Adolescent↗
PubMed1994

Monosymptomatic presentation of type I Arnold-Chiari malformation: report of two cases.

Two cases of type I ACM are described, one of which presented with dizziness in late childhood (case 1), the other with mild intention tremor in adulthood (case 2). Cerebellar ectopia should be considered in monosymptomatic patients even in the absence of other symptoms and signs of C.N.S. dysfunction. Magnetic resonance imaging of the craniocervical junction should be performed because it may be diagnostic for type I ACM.

Adolescent↗
PubMed1994

Human bronchial smooth muscle responsiveness after in vitro exposure to acrolein.

Human isolated bronchi obtained at thoracotomy from 42 patients were exposed to aqueous solutions of acrolein, and the resulting change in contractile responses was evaluated by measuring agonist cumulative concentration-response curves (CCRC). Contractile responses to carbachol were measured after a variety of exposure concentrations, from 0.01 to 3.0 microM, and at times from 5 to 60 min. The optimal condition to induce airway smooth muscle hyperresponsiveness was an exposure duration of 20 min at a concentration of 0.3 microM. The effect of acrolein exposure on human bronchial smooth muscle was also assessed by examining the contractile responses to potassium chloride (KCl), histamine, and neurokinin A (NKA) in both the absence and the presence of phosphoramidon. Although in vitro exposure of the human bronchus to 0.3 microM acrolein did not alter responses to KCl, it did increase the efficacy of carbachol and NKA without altering their potency. This concentration of acrolein also increased the contractile response to low concentrations of histamine and shifted the CCRC to the left. Pretreatment with phosphoramidon abolished the differential effect of acrolein on airway response to NKA. These results suggest that the mechanism of action of acrolein includes inactivation of airway neutral endopeptidase as well as alterations in the pharmacomechanical, but not the electromechanical, coupling of human bronchial smooth muscle.

Acrolein↗
PubMed1993

Effect of in vitro exposure to acrolein on carbachol responses in rat trachealis muscle.

Isolated tracheal rings obtained from male Wistar rats 10 to 15 weeks old and weighing 300 to 400 g were exposed to aqueous solutions of acrolein, and the resulting change of smooth muscle contractility was evaluated by measuring the cumulative carbachol concentration-response curve. Using the product of acrolein concentration and time as a surrogate for the acrolein dose delivered to the smooth muscle cells, contractility measured after a variety of exposure concentrations from 0.01 to 3.0 microM and times from 5 to 60 min could be correlated in a dose-dependent manner. In the range of doses from 0.1 to 6 microM-min, relative contractility continuously increased from 0 to 50% above unexposed control values. At doses greater than 6 microM-min, the enhancement in contractility declined. This decline may have been due to cell damage or cell death which was so severe at a dose of 60 microM-min that contractility fell below control values. Below a threshold dose of 0.1 microM-min, acrolein had no effect on contractility. The role arachidonic acid metabolism in the enhancement of smooth muscle reactivity to carbachol was studied using indometacin to block the cyclo-oxygenase pathway and NDGA to block the lipoxygenase pathway. At a concentration of 10 microM of either indometacin or NDGA, the acrolein-induced enhancement in airway reactivity was completely inhibited. At lower concentrations, inhibition by these two chemicals was partially additive, suggesting that both the lipoxygenase and cyclo-oxygenase pathways play a role in the hyperreactive response.

Acrolein↗
PubMed1993

Effect of passive sensitization on the mechanical activity of human isolated bronchial smooth muscle induced by substance P, neurokinin A and VIP.

1. The effect of passive sensitization on the mechanical activity of human isolated bronchial smooth muscle induced by the following neuropeptides substance P (SP), neurokinin A (NKA) and vasoactive intestinal peptide (VIP) was studied both in the absence and in the presence of the neutral endopeptidase (NEP) inhibitor, phosphoramidon. 2. Cumulative concentration-response curves (CCRC) to these neuropeptides were constructed in human passively sensitized isolated bronchial rings and compared to those in paired controls. Passively sensitized human isolated bronchial rings were tissues incubated overnight in serum from asthmatic patients atopic to Dermatophagoides pteronyssinus and paired controls were tissues originating from the same lung specimens but incubated overnight in serum from healthy donors. 3. In the absence of phosphoramidon, passive sensitization significantly increased the amplitude of the contractile responses to SP and NKA including that to the maximal concentration given from 50 +/- 5% to 76 +/- 6% (n = 5, P < 0.05) and from 70 +/- 7% to 101 +/- 6% (n = 5, P < 0.05) of the maximal response to acetylcholine, respectively. Passive sensitization significantly shifted to the left the CCRC for both tachykinins as measured by the geometric means dose-ratios which were 8.5 (95% confidence limits (CL): 3.1-13.9) and 7.3 (95% CL: 4.2-10.3) for SP and NKA, respectively. 4. In the presence of phosphoramidon (10 microM), passive sensitization still increased significantly the amplitude of the contractile responses to SP and NKA including that to the maximal concentration given from 74 +/- 4% to 115 +/- 7% (n = 5, P<0.05) and from 104 +/- 9% to 146 +/- 16% (n = 5, P<0.05)of the maximal response to acetylcholine, respectively. Passive sensitization still significantly shifted to the left the CCRC for both tachykinins as measured by the dose-ratios which were 9.0 (95% CL:4.3-13.6) and 5.4 (95% CL: 2.9-7.9) for SP and NKA, respectively.5. The relaxant response to the maximal concentration of VIP given in tissues precontracted with histamine (0.5 mM) was significantly reduced by passive sensitization from 41 +/- 4% to 25 +/- 3% (n = 5,P <0.05) of the amplitude of the precontraction in the absence of phosphoramidon and from 72 +/- 1%to 49 +/- 4% (n = 5, P<0.05) in the presence of phosphoramidon (10 microM). Passive sensitization significantly shifted to the right the CCRC for VIP as measured by the dose-ratios which were 10.4(95% CL: 6.6-14.1) and 6.4 (95% CL: 3.0-9.8) in the absence and in the presence of phosphoramidon,respectively.6. We conclude that passive sensitization enhances the mechanical response to neuropeptides which contract human isolated bronchial smooth muscle and reduces that to a neuropeptide which relaxes it.The mechanism of passive sensitization-induced changes in the mechanical activity appears to be independent of a decrease in NEP activity since these changes persist in the presence of the NEP inhibitor, phosphoramidon.

Acetylcholine↗
PubMed1993

Multicentre evaluation of the Bayer DAX system.

The analytical performance of the DAX, a high-throughput random access analyser, was studied according to ECCLS guidelines (ECCLS Document Vol. 3, No. 2, Beuth Verlag, Berlin, 1986) in a multicentre evaluation involving four laboratories. The trial took about 4 months. Determinations of 12 analytes produced more than 60,000 data. The imprecision study on 3 control sera for all analytes gave a within-run CV (median of 4 laboratories) which never exceeded 3% and was below 2% in 94% of the results. The median between-day CV was less than 3% in 92% of the results, with a highest value of 5.0%. No significant drift was detected during the 5-hour work period. No relevant sample- and cuvette-related carry-over was found. The manufacturer's claims concerning linearity were fulfilled or exceeded. The recovery of the assigned values for the control sera (median of 4 laboratories) ranged from 94 to 106%. In the method comparison on patients' samples, deviations were statistically significant in some cases, due to differences either in the methods used or in the calibration of the systems used for comparison; the regression lines, as inspected visually, and the coefficients of correlation were, however, generally acceptable. Imprecision and inaccuracy were within the acceptability limits as recommended by the Société Française de Biologie Clinique (SFBC) (Biochim. Clin. 12 (1988) 284-327) and the Deutsche Gesellschaft für Klinische Chemie (DGKC) (Dt. Arztebl. 85 (11) (1988) A697-A712). The limits of acceptance, proposed more recently by Fraser et al. (Eur. J. Clin. Chem. Clin. Biochem. 30 (1992) 311-317), were met in thirty-three of thirty-six cases. The alpha-amylase assay was significantly affected by bilirubin and haemolysis; interferences for the remaining analytes were predictable and well-known from the literature. The rate of sample throughput was found to be in agreement with that claimed by the manufacturer. The software did not present problems and was readily accepted by the operators. The practicability of the instrument was rated very good. Since the DAX is the primary chemistry analyzer in all four participating laboratories, the present experiments were necessarily intermixed with a large routine workload. Therefore, the system performance was assessed under definitely "usual" conditions. Because of its high productivity and reliability, the DAX is highly suitable for routine use in medium to large sized hospitals.

Blood Chemical Analysis↗