Different efficacy in vitro of hemoglobin based oxygen carriers and red cells.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
E Bucci
Publications and source records attributed to E Bucci.
Manufacturing process of anti-thrombin III concentrate: viral safety validation studies and effect of column re-use on viral clearance.
A manufacturing process for the production of Anti-thrombin IIII concentrate is described, which is based primarily on Heparin Sepharose affinity chromatography. The process includes two sequential viral inactivation/removal procedures, applied to the fraction eluted from the column, the first by heating in aqueous solution at 60 degrees C for 10 h and the second by nanofiltration. Using viral validation on a scaled-down process both treatments proved to be effective steps; able to inactivate or remove more than 4 logs of virus, and their combined effect (>8 logs) assured the safety of the final product. Viral validation studies of the Heparin Sepharose chromatographic step demonstrated a consistency of the affinity of the resin for viruses over repeated use (16 runs), thus providing evidence of absence of cross-contamination from one batch to the next. It was concluded that the process of ATIII manufacturing provides a high level of confidence that the product will not transmit viruses.
Animals↗
Autoantibodies to glutamic acid decarboxylase in downbeat nystagmus.
The cause of downbeat nystagmus (DBN) remains undiagnosed in about 40% of patients. This paper reports the presence of antiglutamic acid decarboxylase antibodies (GAD-Ab) in a patient with DBN. Antibodies against GABAergic neurons located in the vestibular complex may induce chemical denervation of the floccular neurons, which normally suppress the peripheral imbalance between vertical semicircular canal systems, thereby causing DBN. Testing for GAD-Ab may be indicated in DBN patients without an identifiable anatomical brain lesion.
Aged↗
Analysis of B19 virus contamination in plasma pools for manufacturing, by using a competitive polymerase chain reaction assay.
BACKGROUND AND OBJECTIVES: The presence of B19 virus in blood poses a risk of transmission of the virus via blood or blood products. Screening processes for manufacturing should be aimed at achieving production plasma pools with B19 virus contamination levels below 104 genome equivalents/ml (geq/ml) in order to prevent transmission of infection through plasma derivatives. MATERIALS AND METHODS: The suitability of a competitor plasmid as an internal analytical standard for the detection of B19 virus in plasma pools was assessed by using a competitive polymerase chain reaction (PCR) assay. Seventy-five plasma pools, each consisting of 960 single donations, were analysed for B19 virus contamination following a lysis treatment. RESULTS: The amount of competitor plasmid in the competitive PCR assay established, with good accuracy, a threshold value for discrimination of the viral load in plasma pools. Analysis of samples from plasma pools showed that 12% of pools were contaminated with B19 virus at levels above the set threshold value. CONCLUSIONS: The competitive PCR assay developed proved to be effective for discrimination of the B19 virus contamination level in screening of plasma pools for manufacturing.
Blood Donors↗
Satellite potentials on EMG: neurophysiologic evidence of axonal transection in MS?
To detect signs of axonal damage in MS, the authors investigated the occurrence in EMG of motor unit action potentials with satellite potentials (SP-MUAP) in the upper limb muscles in 10 consecutive patients with MS with cervical spinal cord demyelinating lesions and 10 control subjects. Subjects' SP-MUAP rate was 0 to 2.5% (median 0%) in the control group, and 0 to 17.5% (median 7.5%) in the MS group (p < 0.01). Motor unit remodeling secondary to axonal transection of spinal motor neurons traversing cervical demyelinating lesions may be hypothesized.
Adult↗
Clinical guidelines in early detection of oral squamous cell carcinoma arising in oral lichen planus: a 5-year experience.
In recent years, studies on the malignant potential of oral lichen planus (OLP) provided clinical evidence that patients affected by OLP have an increased risk to develop oral squamous cell carcinoma (OSCC); nevertheless, controversies still exist as to whether OLP has inherent predisposition to become malignant, or not. We believe extremely careful management of OLP patient is mandatory, and the aim of this paper is to illustrate our clinical guidelines in evaluating the possible risk of transformation in OLP lesions. Five-hundred and two patients (311 women and 191 men) affected by OLP regularly undergo follow-up examination in our Department. Patients' ages range from 18 to 83 years, with a mean of 55.4 years (57.5 for women and 53.9 for men); minimal follow-up period is 4 months, with a maximum of 12 years. In our group of OLP patients in the past 5 years we detected 24 carcinomas: excluding three cases in which diagnoses of OLP and OSCC were synchronous and three patients who had a history of tobacco use, thus possible malignant transformation of OLP would appear to be 3.7%. Clinical criteria used in our follow-up allowed us to detect 28.5% of tumours as in situ OSCC, 38% as microinvasive OSCC, 28.5% as stage I OSCC and 4.7% as stage II OSCC, with a remarkable improvement in prognosis compared to our previous study in which we adopted different criteria.
Adult↗
Clinical features of gingival pemphigus vulgaris.
BACKGROUND: Pemphigus vulgaris (PV) is a rare, chronic, intraepithelial bullous disease with a potentially fatal outcome. Oral lesions are a hallmark of PV and occur in almost all cases, and represent the preliminary symptom in more than half of the patients. Gingival lesions are very common and, when solitary, often first recognized by periodontist. METHOD: In the literature, gingival localization of PV are usually described as desquamative gingivitis (DG) and/or as vesiculobullous lesions of the free and attached gingiva; in our experience, early lesions only rarely appears as extensive erythema and erosions. CONCLUSIONS: PV at the onset may frequently appear on gingiva as isolated blisters and/or erosions mainly located to the free gingiva, very little in extension and hardly to recognize as bullous lesions.
Biopsy↗
Catenin dislocation in oral pemphigus vulgaris.
Cell-to-cell adhesion is mediated by cadherins (integral membrane proteins), which form a complex with catenins (cytoplasmatic proteins). While E-cadherin expression has been extensively studied in many human skin diseases, less is known about the expression levels of catenins in oral blistering diseases. The purpose of this study was to evaluate the role of these proteins in the pathogenesis of acantholysis in oral pemphigus vulgaris. We evaluated by immunohistochemistry beta- and gamma-catenin expression in 7 cases of oral pemphigus vulgaris (PV) at various stages of the disease and, as controls, in 18 healthy patients. Healthy cases showed, as reported in the literature, a strong reactivity with both beta- and gamma-catenins, with the intensity of staining progressively decreasing from the spinous to the keratinised layers of epithelium, which had a prevalent cellular membrane expression. In PV patients, we detected a loss of membrane expression of these molecules with a progressive displacement of the signal toward the cytosol and, for gamma-catenin, nuclear dislocation, particularly in areas with intense acantholysis.
Adult↗
The treatment of oral aphthous ulceration or erosive lichen planus with topical clobetasol propionate in three preparations: a clinical and pilot study on 54 patients.
BACKGROUND: This study evaluated the clinical use of a corticosteroid in three preparations (topical clobetasol propionate ointment, clobetasol propionate in an oral analgesic base, and clobetasol propionate in an adhesive denture paste). METHODS: Fifty-four patients (34 males and 20 females) with a history of vesiculo-ulcero-erosive oral lesions were selected: 24 with oral erosive lichen planus and 30 with aphthae. The subjects enrolled were randomly divided into three groups, each of 18 patients (10 with aphthae and 8 with lichen planus): the first was treated with topical clobetasol propionate ointment (0.05%) directly on the lesion(s) three times a day; the second with clobetasol propionate in an adhesive denture paste in equal amounts (1:1) two times a day; the third with clobetasol propionate in an oral analgesic base (Orabase-B) in equal amounts (1:1) two times a day. Each subject scored his or her symptoms daily from most severe (7) to none (0) by verbal assessments using a categorical scale. RESULTS: In all cases, the administration of the corticosteroid was effective in producing remission of symptoms in each group of patients. Significant differences (P<0.05) between groups were determined by the Kruskal-Wallis test. The Dunn test was used in order to detect which group differs from the others; clobetasol and adhesive denture paste correlated with an early remission of pain in lichen and apthous lesions. CONCLUSION: The results suggest that topical application of clobetasol in an adhesive denture paste is an effective drug for symptomatic oral vesiculo-erosive and/or ulcerative lesions.
Adhesives↗
Cell-free hemoglobin, oxygen off-load and vasoconstriction.
Explore the source record for details and available documents.
Erythrocytes↗
Hemoglobin based oxygen carriers at a cross road: the old paradigms must be abandoned and much more basic science investigation is necessary.
Explore the source record for details and available documents.
Animals↗
Lack of hypercapnic increase in cerebral blood flow at high blood viscosity in conscious blood-exchanged rats.
BACKGROUND: The hypothesis of a compensatory dilation of cerebral vessels to maintain cerebral blood flow at a high blood viscosity was tested during hypercapnia in the study after replacement of blood by hemoglobin solutions of defined viscosities. If compensatory vasodilation exists at normocapnia at a high blood viscosity, vasodilatory mechanisms may be exhausted when hypercapnia is added, resulting in a lack of increase in cerebral blood flow at hypercapnia. METHODS: In conscious rats, blood was replaced by ultrapurified cross-linked hemoglobin solutions that had defined and shear rate-independent low or high viscosities (low- and high-viscosity groups). Blood viscosity differed threefold between both groups (1.2 vs. 3.6 mP x s). Thereafter, rats inhaled either a normal or an increased concentration of carbon dioxide in air. Cerebral blood flow was determined by the iodo[14C]antipyrine method. RESULTS: During normocapnia, global and local cerebral blood flows did not differ between both groups. With increasing degrees of hypercapnia, global and local cerebral blood flows were gradually elevated in the low-viscosity group (2.8 ml x mmHg(-1) CO2 x 100 g(-1) x min(-1)), whereas they remained unchanged in the high-viscosity group. CONCLUSIONS: Changes in blood viscosity do not result in changes of cerebral blood flow as long as cerebral vessels can compensate for these changes by vasodilation or vasoconstriction. However, such vascular compensatory adjustments may be exhausted in their response to further pathophysiologic conditions in blood vessels that have already been dilated or constricted as a result of changes in blood viscosity.
Animals↗
Metastases in small thickness oral squamous-cell carcinoma arising in oral lichen planus.
Oral lichen planus (OLP) is classified among precancerous conditions, as it is considered a generalized state associated with a significantly increased risk of cancer. The objective of this study was to discuss ultra-structural aspects of OLP that could play a role in enhancing metastatic potential, thus worsening the prognosis in oral squamous-cell carcinoma (OSCC). We report four cases of microinvasive OSCC which have occurred in OLP patients. All of them were stage I tumors, with a mean thickness of 1.75 mm. Recent studies indicate a tumor thickness over 4 mm as predictive of nodal metastases, but within 6 mo, our four patients with OSCC arising from OLP developed lymphnodal metastases. Our findings suggest that OLP-related OSCC may have a worse prognosis because of increased metastatic potential; obviously, further investigation is required, but this preliminary evidence emphasizes that extremely careful management of OLP patients is mandatory, and in cases of OSCC arising from OLP, a more radical treatment is probably required.
Aged↗
Adipyl crosslinked bovine hemoglobins as new models of allosteric systems.
As indicated by peptide analyses and mass spectrometry estimations, intramolecular crosslink with bis(3,5-dibromosalicyl)adipate of bovine hemoglobin results in the formation of two main components covalently bridged across the beta-cleft. In one component the crosslink joins the beta(1)V1-beta(2)K81 residues (XL-Peak-1), in the other the bridge is between the beta(1)K81-beta(2)K81 residues (XL-Peak-2). Both components are tetrameric with a mass near MW = 67 kDa as estimated by gel filtration, and a hydrodynamic radius near 3. 20 nm, estimated by dynamic light scattering. They have very low oxygen affinity with Pm near 100 mmHg (XL-Peak-1) and near 70 mmHg (XL-Peak-2) respectively at 37 degrees C, at neutral pH. The Bohr effect is almost absent in XL-Peak-1, while in XL-Peak-2 it is very near normal. Both systems show oxygen binding cooperativity with an index near n = 2.0. Flash photolysis kinetics of the recombination with CO could be resolved into a fast and a slow component. The amplitude of the fast rates were not concentration-dependent. The stopped-flow kinetics were autoaccelerating, consistent with their ligand-binding cooperativity. All rates were very similar to those of normal hemoglobin, suggesting that the oxy- rather than the deoxy-forms of the systems were affected by the crosslink. Proteins 2000;39:166-169.
Allosteric Site↗
The two dimeric forms of RNase A.
In 1965 Fruchter and Crestfield (J. Biol. Chem. 240, 2868-3874) observed that dimeric RNase A prepared by lyophilization from acetic acid could be separated into two forms. Surprisingly, no other structural or functional differences could be detected between the two forms. In 1998 a structure for dimeric RNase A was determined by X-ray crystallography by Liu et al. (Proc. Natl. Acad. Sci. USA 95, 3437-3442). We found that the two forms of dimeric RNase A have indeed different structural and functional properties, and suggest that the dimer whose structure was investigated by Liu and coworkers may be identified with the lesser form of dimeric RNase A.
Animals↗
Effect of lengthening of peptide backbone by insertion of chiral beta-homo amino acid residues: conformational behavior of linear peptides containing alternating L-leucine and beta-homo L-leucine residues.
The synthesis and the solution behavior of the linear peptides containing a beta-homo (beta-H) leucine residue-Boc-Leu-beta-HLeu-Leu-OMe, Boc-beta-HLeu-Leu-beta-HLeu-Leu-OMe, and Boc-Leu-beta-HLeu-Leu-beta-HLeu-Leu-OMe-as well as the solid structure of the tripeptide, are reported. The conformational behavior of the peptides was investigated in solution by two-dimensional nmr. Our data support the existence in solution with different families of conformers in rapid interchange. The crystals of the tripeptide are orthorhombic, space group P2(1)2(1)2, with a = 15.829(1) A, b = 29.659(1) A, c = 6.563(1) A, and Z = 4. The structure has been solved by direct methods and refined to final R1 and wR2 indexes of 0.0530 and 0.1436 for 2420 reflections with I > 2sigma(I). In the solid state, the tripeptide does not present intramolecular H bonds, and the peptide backbone of the two leucine residues adopts a quasi-extended conformation. For the beta-HLeu residue, the backbone conformation is specified by the torsion angles straight phi(2) = -120.9(4) degrees, mu(2) = 56.7(4) degrees, psi(3) = -133.2(4) degrees. The side chains of the three residues assume the same conformation (g(-), g(-), trans), and all peptide bonds, except the urethane group at the N-terminus, are in the trans conformation. Preliminary conformational energy calculations carried out on the Ac-NH-beta-HAla-NHMe underline that the conformations with mu angle equal to 180 degrees and 60 degrees assume lower energy with respect to the others. In addition, we found a larger conformational freedom for the psi angle with respect to the straight phi angle.
Crystallography, X-Ray↗
In vivo administration of GM-CSF promotes the clearance of apoptotic cells: effects on monocytes and polymorphonuclear leukocytes.
The clearance of apoptotic cells is crucial to avoid chronic inflammation and autoimmunity. Little is known about the factors that regulate it in vivo. We show that granulocyte-macrophage colony-stimulating factor (GM-CSF) administration to carcinoma patients confers to their leukocytes a significantly higher ability to phagocytose apoptotic cells than before (P < 0.005). GM-CSF increased the concentration of monocytes and polymorphonuclear leukocytes in the peripheral blood and activated circulating polymorphonuclear leukocytes. Both effects abated early after treatment, whereas phagocytosis of apoptotic cells was still significantly higher after 18 days compared with basal values (P < 0.005 and P < 0.025 for monocytes and polymorphonuclear leukocytes, respectively). On in vitro phagocytosis of apoptotic cells monocytes, but not polymorphonuclear leukocytes, up-regulated MHC class II membrane expression. These findings are consistent with the possibility that GM-CSF endows both scavenger and antigen-presenting leukocytes with the ability to internalize apoptotic tumor cells.
Adult↗
Oral pemphigus: long term behaviour and clinical response to treatment with deflazacort in sixteen cases.
Systemic corticosteroids remain the mainstay of therapy for pemphigus. Their use has transformed what was almost invariably a fatal illness into one whose mortality is now below 10%. Unfortunately, the high doses and prolonged administration of corticosteroids that are often needed to control the disease result in numerous side effects, many of which are serious or even life-threatening. Sixteen patients affected by oral pemphigus vulgaris were retrospectively examined to illustrate the natural course of the disease and to describe the efficacy of the treatment we utilised. Deflazacort, used with azathioprine, is the steroid of first choice in our therapeutic protocols, while cyclophosphamide and methylprednisolone "pulse therapy" are reserved for cases unresponsive to high doses of oral corticosteroids. In addition, the literature on oral pemphigus vulgaris was reviewed with respect to clinical history, signs and symptoms, management, and treatment outcome.
Administration, Oral↗