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Biomedical subjects

R Bruni

Publications and source records attributed to R Bruni.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cascade filtration (CF) with the Haemonetics MCS+: a new technical adaptation.

CF was introduced in clinical medicine in 1980. Up to now, exclusively two-vein procedures have been carried out with some limitations to expansion of this technique. In this report we describe the very first application of single-needle CF carried out with Haemonetics MCS + apparatus. Twenty procedures were completed without any untoward effect in patients suffering from TTP, post-hepatitic cryoblobulinemia, familial hypercholesterolemia and acute Guillan-Barrè Syndrome. From 1 to 4 sessions were carried out per patient with the expected laboratory and clinical results. The only limit is the procedure time that averages 231 +/- 48 min., approximately 40% longer than two needle procedures.

Cryoglobulinemia↗
PubMed2000

High molecular weight polyethylene oxides (PEOs) as an alternative to HPMC in controlled release dosage forms.

High molecular weight polyethylene oxides (PEOs) have recently been proposed as an alternative to hydroxypropylmethylcellulose (HPMC) in controlled release matrix tablets. In this study, we compared the performance of PEO and HPMC polymers when employed in the Geomatrix technology, a versatile, well-known method to achieve extended release of drugs at a constant rate. Four core formulations were prepared, containing a soluble drug (diltiazem) and, alternatively, PEO or HPMC of two different viscosity grades. These formulations have the same composition except for the polymer employed. Similarly, four barrier formulations were also prepared, which only differ in the kind of polymer employed. Three-layer Geomatrix systems were then prepared using these core and barrier formulations. The release profiles of the different three-layer systems obtained were compared, to verify if PEO could efficiently replace HPMC in this type of dosage form. The results show that slower release rates can be obtained from the plain matrices containing HPMC compared to PEO, moreover HPMC, used in the barrier formulations, is generally more efficient in controlling drug release rate in three-layer Geomatrix systems.

Calcium Channel Blockers↗
PubMed2000

Clinical application of therapeutic erythrocytapheresis (TEA).

Therapeutic erythrocytapheresis (TEA) has been used in different diseases such as polycythemia vera (PV), secondary erythrocytosis or hemochromatosis as a process of the less cumbersome but more expensive phlebotomy. TEA is preferred in emergency conditions such as thrombocytosis or in conditions such as porphyria cutanea tarda (PCT) or erythropoietic porphyria when plasma exchange (PEX) is often combined with TEA to reduce extracellular levels of uroporphyrin which contribute to plasma hyperviscosity. TEA is often combined with drug therapy that varies from etoposide in PV to EPO and desferoxamine which are used to mobilize and reduce iron stores in hemochromatosis. Benefits from this combination may be more long lasting than expected. Nonetheless for TEA, there is no standard protocol and, clinical experience with this therapy remains highly anecdotal. Therapeutic red cell-exchange (TREX) has been used with much interest over the years, starting with the management of hemolytic disease of the newborn and later used to correct severe anemia in thalassemia patients thereby preventing iron overload. It has also been used for the management of complications of sickle cell disease such as priapism, chest syndrome, stroke, retinal, bone, splenic and hepatic infarction or in preparation for surgery by reducing HbS to less than 30%. Automated apheresis has also favored the use of TREX in conditions such as paroxysmal nocturnal hemoglobinuria and aniline poisoning, arsenic poisoning, Na chlorate intoxications and CO intoxications, hemoglobinopathies, autoimmune hemolytic anemia, reactions due to ABO incompatibility, in preparation for ABO incompatible bone marrow transplantation or for preventing anti-D immunization after the transfusion of D(+) cells to D(-) recipients. Another field of application has been in the emergency management of intraerythrocytic parasite infections such as malaria and babesiosis. Application of TREX may be wide but its real use remains limited. In our personal experience, in 16 years, only 167 TREX procedures have been carried out in a total of 13,747 therapeutic procedures. This represents only 1.21% of the total.

Anemia, Sickle Cell↗
PubMed2000

PCR testing for HCV in anti-HCV negative blood donors involved in the so called HCV +ve post-transfusion hepatitis.

UNLABELLED: Although it is infrequent, post-transfusion HCV infection may occur if the donors blood is collected in the window period between exposure and anti-HCV detectability by ELISA testing. STUDY DESIGN: In these last years, despite of routine application of anti-HCV testing, our blood transfusion center has been involved in 53 cases of alleged post-transfusion HCV hepatitis and look-back programs were set up with the goal of finding out the donors possibly involved in viral transmission. Most of these patients were hematological cases with multiple transfusions given because of aplastic anemia (3 cases), leukemia with or without bone marrow transplantation (5/4 cases) but necessitating long-term platelet support, leukemia and solid cancer patients undergoing autologous PBSC transplantation (3/4 cases) and TTP (2 cases). Only 32 patients were of the simple medical or surgical type, 9 transfused because of cardiac or vascular surgery, 8 because of spine surgery, 5 for different diseases and 5 for different types of cancer surgery. Donor's infectivity was determined by ELISA anti-HCV testing, by recombinant immunoblotting assay, and by nucleic acid testing. RESULTS AND CONCLUSION: No donors out of 267 traced of a total of 359 involved was found with anti-HCV seroconversion, or positive on PCR testing. This suggests that the responsibility for HCV transmission can only hypothetically be related to blood or blood components and that other transmission routes should be found out.

Blood Donors↗
PubMed2000

Lipid composition of wild ecuadorian Theobroma subincanum Mart. seeds and comparison with two varieties of Theobroma cacao L.

The present work analyzes the lipid fraction from seeds of wild Ecuadorian Theobroma subincanum and selected commercial varieties of Theobroma cacao from Mexico (var. Criollo) and Ecuador (var. Arriba). The lipid fraction was obtained from the seeds through supercritical fluid extraction and analysis performed by preparatory thin-layer chromatography followed by gas chromatography. The results revealed that in T. subincanum the triglycerides contain fatty acids with longer chains. The melting point and peroxide and saponifiable numbers were determined for each Theobroma sample. The results lead to the conclusion that T. subincanum would produce a poorer quality butter than T. cacao. Nevertheless, the results do point toward a significant commercial use of T. subincanum for low-profile products.

Cacao↗
PubMed2000

Comparison of functional efficacy of surfactant protein B analogues in lavaged rats.

Leakage of plasma proteins into the alveoli inhibits pulmonary surfactant function and worsens respiratory failure. Surfactant protein B (SP-B), is essential for surfactant function, but the N-terminal domain of human SP-B (residues 1.25, SP-B1-25) can mimic the biophysical properties of full length SP-B1-78 in vitro. The authors compared the function and inhibition resistance of synthetic surfactant preparations containing SP-B analogues to a natural bovine surfactant preparation "Survanta". Eight groups of eight rats were lavaged to induce surfactant deficiency, fibrinogen was instilled as a surfactant inhibitor, and then they were rescued with exogenous surfactant. Five experimental surfactants were formulated by mixing 3% SP-B1-78, or an equimolar amount of SP-B1-25 and/or 1% palmitoylated surfactant protein C (SP-C)1-35, into a standard phospholipid (PL) mixture: B1-78, B1-25, C1-35, B1-78+C1-35, and B1-25+C1-35 surfactant preparations. Survanta was used as a positive control and PL and no treatment as a negative control. Lung function was assessed during a 2-h period using arterial blood gas and lung compliance measurements. Rats treated with B1-25+C1-35 surfactant and Survanta maintained the highest oxygenation and lung compliance values throughout the experiments. The surfactants could be ranked as B1-25+C1-35 surfactant and Survanta >B1-25 and B1-78+C1-35 surfactants >others. Because the N-terminal domain of surfactant protein B1-25 can improve inhibition resistance, it may be able to substitute for surfactant protein B in exogenous surfactant preparations.

Animals↗
PubMed2000

Paradoxical effects of exogenous proteins on lung function in surfactant-deficient rats.

Leakage of plasma proteins into the alveolar space can inhibit pulmonary surfactant function and worsen respiratory failure in ventilated preterm infants. We tested the effect of intratracheal instillation of fetal calf serum (FCS) and fresh frozen plasma (FFP) on lung function in ventilated rats who were made surfactant-deficient by saline lavage. Post lavage, the rats were treated with air placebo, Survanta, FCS or FFP, air placebo + FCS or FFP 1 hour post lavage, or Survanta + FCS or FFP 1 hour post lavage. After 2 hours of ventilation, pressure volume curves were performed and the lungs relavaged. FCS instillation rapidly improved oxygenation when given immediately post lavage or 1 hour after placebo or Survanta instillation, whereas FFP instillation never improved oxygenation. FCS instillation increased post-treatment lavage phospholipid values, but FFP did not. Both FCS and FFP decreased lung volume, but the negative effect of FFP exceeded that of FCS. Surfactant aggregate sizing of the final lung lavages by dynamic light scattering showed a definite shift towards smaller aggregates after FFP, but not after FCS, instillation. These data suggest that intratracheal instillation of FCS improves oxygenation and preserves the alveolar presence of phospholipids and large surfactant aggregates, whereas FFP decreases oxygenation and surfactant aggregate size in surfactant-deficient lavaged rats.

Animals↗
PubMed2000

Therapeutic hemapheresis as of 2000.

The main task of therapeutic hemapheresis remains doing the right thing and doing the right thing right. If objective results have been slow to take hold it is in large part because several physicians have resisted continuous improvement since therapeutic apheresis was considered so efficient to boomerang preventing elimination of unnecessary procedures and treatments. The right thing to do is treating patients who may respond in a specific phase of their disease, frequently along with the right drugs. Doing right the right thing is to take advantage of the new technologies and, medical culture which have led apheresis to the recent complexity and efficacy. In the following pages we are trying to update the state-of-the-art and new trends which characterize therapeutic apheresis at the beginning of 2000.

Blood Component Removal↗
PubMed2000

Acute intravascular hemolysis in two patients transfused with dry-platelet units obtained from the same ABO incompatible donor.

Since 1989 we have been collecting dry-platelets on a routine basis. Dry-platelets are those collected along with 25-30 ml of contaminating plasma cell with separators such as the Amicus, AS 104 and the Excel Pro. Platelets are resuspended in non plasma media for storage and for at least 60 hours their viability and functionality are not impaired. In this article we report on two hemolytic crises determined by two O Rh D + units of single donor platelets (SPD) taken from the same donor in a double-apheresis session. The two split units were administered to two A Rh D + patients suffering from metastatic breast cancer and severe aplastic anemia (SAA) respectively. In both cases the hemolytic reaction was of the intravascular type, with a drop in hemoglobin (Hgb) level from 8.6 to 5.4 and from 8.8 down to 5.3 g/dl respectively. From the patients' RBC only alpha agglutinins were eluted and donor's indirect antiglobulin test (IAT) was negative with extended panel RBCs. In the first case the clinical course after erythroexchange (Erex) was uneventful whereas in the second one, that suffering from SAA, after Erex, acute renal failure and shock did complicate the clinical course and the patient died seven days after the incriminated platelet transfusion.

ABO Blood-Group System↗
PubMed1999

Activation of the N-myc2 oncogene by woodchuck hepatitis virus integration in the linked downstream b3n locus in woodchuck hepatocellular carcinoma.

In the woodchuck hepatitis virus (WHV)/woodchuck model for hepatitis B virus-induced hepatocellular carcinoma, frequent activation of N-myc oncogenes by WHV integration has been firmly established. N-myc2, the most frequently affected gene, was reported to be activated by WHV insertion either in the proximity of the gene or in a distant uncoding locus, win. We previously reported that a WHV integration cloned from a liver tumor was located in a chromosomal locus already described by others as the site of WHV integration in another hepatocellular carcinoma. On this basis, the locus, named b3n, was defined as a recurrent site of WHV integration. A scaffold or matrix attachment region (S/MAR) element was subsequently shown to be located in this locus approximately 1 kb from the WHV insertion sites. S/MARs are genetic elements involved both in structural and functional organization of chromosomal DNA and in stimulation of gene expression. In the present work, we investigated the possibility that an N-myc gene might be affected by integration in b3n. Analysis of a liver tumor harboring WHV integration in this locus showed N-myc2 overexpression. By restriction analysis, the b3n locus was shown to be located downstream of N-myc2, so the known sites of viral insertion in b3n were approximately 11 kb downstream of the N-myc2 promoter. Although these data support that WHV insertion in b3n activates N-myc2, the mechanisms previously described to be involved in N-myc2 activation do not appear to properly account for activation in this subset of WHV integrations. Available data suggest that activation of N-myc2 by WHV integration in b3n might be mediated by the S/MAR located near the WHV insertion.

Animals↗
PubMed1999

Influence of the moisture on the performance of a new dry powder inhaler.

An accelerated stability test was carried out on two prototypes of a new dry powder inhaler (DPI) to verify the influence of moisture uptake on the performance of the device. The prototypes were stored at 40 degrees C and 75% relative humidity (RH) for different storage times and their performance was assessed in terms of emitted dose and respirable fraction (Twin Impinger). At the same time intervals, the water content of the powder contained in the drug reservoir was evaluated using Karl Fischer's method. The respirable fraction was strongly influenced by the moisture content of the powder, on the contrary, the dosing precision and reproducibility is independent of this variable. The results show that a suitable protection from the external environment is necessary to prevent moisture uptake in the powder and the consequent loss of efficiency of the delivery device.

Drug Delivery Systems↗
PubMed1999

Sensitivity of synthetic surfactants to albumin inhibition in preterm rabbits.

Surfactant can be inhibited in vivo by plasma proteins invading the alveolar space during acute lung injury. The resistance to protein inhibition of surfactant preparations with various synthetic surfactant proteins B and C (B and C) was tested in preterm rabbits. Surfactants consisted of a palmitic acid containing phospholipid mixture (PL) with full-length SP-B peptide (B1-78), one of two SP-B mutants (Bserine and BR236C), the synthetic SP-B mimic KL4 (UCLA-KL4), a natural SP-B (Bbovine), synthetic palmitoylated SP-C peptide (C1-35), a combination of B1-78 + C1-35, a combination of BR236C + C1-35, and the clinical surfactant Survanta. Preterm rabbits born at 28 days of gestation were ventilated and received 100 mg/kg of albumin intratracheally at 30 min and 100 mg/kg of surfactant at 45 min after birth. Dynamic lung compliance (tidal volume/mean airway pressure) decreased from 0.82 to 0.57 mL/kg/cm H2O after albumin instillation and to 0.43 mL/kg/cm H2O over a 60-min period after saline placebo. Treatment with B1-78 + C1-35 and BR236C + C1-35 surfactant and Survanta returned dynamic compliance to prealbumin values, B1-78, BR236C, Bbovine, and C1-35 surfactant stabilized dynamic compliance, but PL, Bserine, and UCLA-KL4 surfactant were unable to prevent a further deterioration in dynamic compliance. These data suggest that a combination of synthetic surfactant peptides B1-78 and C1-35 and the clinical surfactant Survanta confer a high degree of resistance to surfactant inhibition by human albumin in ventilated preterm rabbits.

Animals↗
PubMed1999

Dry platelets with the Dideco Excel apparatus.

Dry platelets are required to prevent hemolytic and nonhemolytic febrile reactions after transfusion to ABO mismatched recipients, to reduce the risk of HLA immunization and to prevent allergic or anaphylactic reactions. Previously we have shown that the collection of single donor platelets almost free of plasma is possible with different cell separators. With the systems we described for the CS 3000+/Amicus and AS 104-204 apparatuses collection of dry platelets implies their resuspension in non plasma solutions after opening the circuit. With the new system developed by Dideco for the Excel apparatus this moreover is no longer required since the platelet bag can be connected to the resuspending medium through a dedicated line with an antibacterial filter. Platelets are collected cyclically and the resuspending solution is added when the procedure is over. In this study 53 collections were evaluated, 21 of which were erythrothrombocytapheresis. In 60-65 min 4.21 of anticoagulated blood (1/12) were processed with platelet collection automatically done after 6-700 ml cycles. The platelet yield averaged 4.67 +/- 0.7 x 10(11), with a platelet efficiency per minute of 7.18 +/- 0.9 x 10(9). The WBC contamination averaged 2.6 +/- 0.7 x 10(5) and contamination did not exceed 0.87 x 10(6). The quality of platelets was satisfactory as measured by aggregation, morphology score, and CD 62 membrane glycoprotein externalization. These results were comparable to those obtained with three other Excel apparatuses used in the conventional way to collect platelets resuspended in plasma or with the Amicus used to collect dry platelets using an open system.

Cell Separation↗
PubMed1999

Automatic volumetric capillary cytometry in the routine of an apheresis unit involved in multicomponent collection.

In apheresis, leukodepletion by secondary filtration of the platelet components or by the primary use of special high efficiency apparatuses is widely used to meet current clinical practice. Leukodepletion of RBC is mandatory for hematooncological patients and new filters for plasma are progressively being introduced in the routine of European blood banks. However, since the monitoring of leukodepletion efficiency continues to be carried out manually using the Nageotte or the microdroplet fluorescence assay (MFA), inaccuracy and labour-intensity of counting will limit the possibility of satisfying the increasing demand for leukodepletion monitoring. Volumetric capillary cytometry (VCC) is a totally automated system that has been shown to correlate well with Nageotte, MFA and flow-cytometric countings of residual leukocytes in platelet and RBC product. In this article we describe the application of VCC in the quality control program of our hemapheresis unit in which all apheresis donations are of the multicomponent collection type.

Automation↗
PubMed1999

Autoapheresis and intraoperative blood salvage in oncologic surgery.

Transfusion of predeposit or salvaged autologous blood has continued to grow since the 1980s. Issues such as the indications for use and cost effectiveness as well as the safety of autologous blood salvaged during cancer surgery have emerged and should be addressed. The concern for possible contamination of autologous RBC with cancer cells responsible for metastasis has limited the use of autologous salvaged blood in cancer patients. Nevertheless, clinical experience has been gained on the use of salvaged blood in patients with colorectal, gastric, renal, hepatic, breast, bladder and lung cancer. No evidence has been reported showing an increase in metastasis or a decrease in patient survival, in spite of the obvious demonstration that salvaged blood is contaminated with viable tumor cells which are not washed out of the RBC layer during intraoperative blood salvage (IOBS). However, a number of limitations have hampered the widespread use of IOBS in these patients and the technique is not well established. Increasing knowledge of the deleterious effects of allogeneic blood transfusion both in terms of the increased number of viral or bacterial infections and the down-regulation of the patient's immune system have recalled attention to IOBS and to the techniques such as filtration, which might reduce the risk of reinfusion of cancer cells, or totally eliminate the risks such as irradiation has been proposed by Hansen's group. This paper reviews the topic with some emphasis on our personal experience with gamma and X-ray irradiation of salvaged blood in a large reference hospital, where IOBS and filtration of salvaged blood were established for use in cancer patients in 1993 and 1996.

Blood↗
PubMed1999

Cascade filtration for TTP: an effective alternative to plasma exchange with cryodepleted plasma.

TTP remains enigmatic both in terms of etiology and management. The most recent approach is aggressive plasma exchange (PE) employing cryopoor plasma for replacement, based on the pathogenetic relevance given to exceedingly large Von Willebrand (VWF) multimers in the determination of the syndrome with normalization during remission. PE with fresh frozen plasma (FFP) is better than FFP infusion as shown by a recent Canadian study, supporting the theory that to treat TTP an offending circulating agent needs to be removed from the patient's plasma in contrast to the hypothesis that a missing factor is to be given along with FFP. A more recent hypothesis is supported by the results of studies published by the end of 1998 [Moake J, Chintagumpala M, Turner N et al. Blood 1994;84:490-97; Moake J, McPherson PD. Am J Med 1989;87: 3-9N] which would show that TTP is mediated by auto-antibodies to VWF-cleaving protease, or is the result of deficiency of the protease ascribed to abnormalities in its production, function or survival. Plasmapheresis without plasma infusion is relatively ineffective perhaps because it does not increase the protease activity. Cascade filtration (CF) is the autologous counterpart of plasmapheresis. It has been used by our group since 1980 to remove from patients plasma macromolecules such as VWF, fibrinogen, LDL and circulatory immune complexes (CIC). After secondary filtration, the autologous plasma has a composition which is very similar to that of allogeneic plasma after cryoprecipitation, a product which used in the management of TTP. Based on this knowledge, in 1994 we began to use CF in the treatment of TTP patients. In the beginning (7 patients) CF was combined with a decreasing number of conventional PEs using allogeneic plasma for substitution. Lately only CF with some plasma supplementation has been used in the last 9 cases. From a clinical point of view our 16 patients achieved remission after a number of treatments (11 +/- 7) that compares sufficiently well with those required by our historical control group of 47 cases (14 +/- 13). Of course the patient's exposure to allogenic plasma was significantly lower for patients in the CF only group (1.4 +/- 1.2 plasma U/session) compared to the PE + CF group (4.4 +/- 2.3 plasma U/session) or for the controls treated by PE only (10.8 +/- 4.6 plasma U/session). There were no deaths in the CF or PE + CF groups and no untoward effect was observed. On the contrary there were 5 deaths (1 on the day of presentation) in the PE group, and 1 HBV and 2 HCV infections as well as 4 severe allergic reactions to plasma proteins (or passive antibody infusion). We conclude that CF is presently the best treatment to offer to patients suffering from sporadic TTP and that CF may contribute to expanding the knowledge of the pathogenetic mechanisms of this uncommon multisystem disorder.

Adult↗