Biomedical subjects
Publications and source records attributed to A Moroni.
In this report we describe the use of a newly developed immunofluorescence technique performed with living spirochetes to detect serum antibody to B. burgdorferi s.l. in a case of early Lyme borreliosis. The immunofluorescence method used (surface immunofluorescence assay: SIFA) proved useful in the serological evaluation of suspected cases of Lyme disease.
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Between 1981 and 1989 22 bicondylar fractures of the distal humerus were operated on. Fractures were classified according to the AO system. Fixation consisted of medial and lateral plates combined to articular screws in 14 cases, one articular screw associated to one medial screw and a lateral plate in four cases, three lag screws in three cases, and in one case the articular screw was associated to one medial screw and one 'Y' plate. Osteotomy of the olecranon was fixed by one intramedullary screw and one wire in 15 cases, other simpler methods (wire or screw alone) were used in seven cases. A scoring system that included pain, range of motion, radiological results and postoperative activity level, was developed to study the results. Two fractures went to nonunion. Results were quoted as excellent in six cases, good in five cases, fair in eight patients and poor in three cases. Younger patients achieved a better range of motion (P = 0.039) and better functional level (P = 0.015), and differences in radiological score (P = 0.029), activity level score (P = 0.048) and total score (P = 0.0031) were observed depending on the anatomical fracture type.
Two different groups of hydroxyapatite (HA) coated and uncoated porous titanium implants, 250-350 microns and 500-700 microns diameter beads, were press-fitted into femoral canine cancellous bone. After 12 wks, the dogs were killed and histomorphometric backscattered electron microscopy studies were carried out. Comparing HA coated versus uncoated implants in the 250-350 microns bead diameter group, the percentage of bone (P = 0.01) and bone index (P = 0.01) were higher in the HA coated implants. Comparing HA coated versus uncoated implants in the 500-700 microns bead diameter group, bone ingrowth (P = 0.01) and bone depth penetration (P = 0.008) were higher in HA coated samples. It can be concluded that the HA coating was an effective method for improving bone formation and ingrowth in the porous implants.
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Anaphylatoxins generated by complement activation by filter membranes are present in plasma during hemodialysis (HD). In the presence of endotoxins which may contaminate the dialysate, they can trigger monocytes to produce interleukin-1 (IL-1) and tumor necrosis factor (TNF), with detrimental effects for the patients. We have investigated whether or not the use of complement activating (cuprophan) and non- (or less-) activating membranes (polysulfone, polymethylmethacrylate or polyacrylonitrile) per se influences cytokine levels in HD patients. Our results indicate that if a sterile bicarbonate solution is used as dialysate, there are no significant increases in IL-1, TNF, interleukin-2 (IL-2) and soluble IL-2 receptors (sIL-2r) throughout HD, even with cuprophan membranes. Moreover even a prolonged use of this membrane (three months) did not change pre-dialysis levels of cytokines and receptors. Use of complement activating membranes also does not influence beta 2 microglobulin levels.
546 human sera from healthy subjects, subjects with cytomegalovirus or Epstein-Barr virus infection and from cordal blood were tested for the human herpesvirus-6 (HHV-6) IgG content in an enzyme-linked immunosorbent assay (ELISA) to verify results previously obtained with an immunofluorescence assay (IFA). The HHV-6 isolate CV, obtained from a child with exanthem subitum, employed as antigen in both tests, belonged to HHV-6 variant B. The ELISA results were similar to those obtained with IFA. 445/546 (81.5%) sera had the same type of reactivity with the two serological procedures. To establish whether different HHV-6 strains may give different serological results, 117 out of the 546 sera tested with IFA against CV infected cells were also tested against cells infected with the HHV-6 isolate U1102 belonging to variant A. All the sera showed a similar reactivity.
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Virological studies were carried out on 3 to 36-month-old patients admitted to the Children's Hospital of the University of Modena with febrile syndrome from September 1990 to February 1991. Virological tests were carried out for human herpesvirus-6 (HHV-6), Epstein-Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus 1 (HSV-1), adenoviruses, parainfluenza viruses 1, 2 and 3, respiratory syncytial virus (RSV) and influenza viruses A and B. Viral infections were confirmed in 60.7% patients: 39.6% were correlated with HHV-6, 5.4% with EBV, 5.4% with both HHV-6 and EBV, 5.4% with adenoviruses, 1.8% with HSV-1, 1.8% with CMV and 1.8% with an unidentified herpes-like lymphotropic virus. HHV-6 isolates were obtained from either peripheral blood lymphocytes (PBLs) or pharyngeal secretion of the infected children. HHV-6 infections included both primary infections (72%) and reactivations (28%). Among HHV-6 infected children, 40%, with exanthem subitum, had infections presenting serological evidence of primary infection and virus isolation from PBLs. The remaining cases of primary infection and the cases of reactivation were found in patients with febrile syndrome without rash (60%). HHV-6 isolates were obtained either from PBLs or pharyngeal secretions from these patients. Southern blot hybridization of the DNAs of 4 HHV-6 isolates showed that the circulating HHV-6 strains all appeared similar, but differed from the HHV-6 strain U1102 used as a positive control.
The study was focused on the bone tissue response to two types of ceramic coating [alumina and hydroxyapatite (HA)] obtained with a plasma-spray technique. The HA coating was performed on titanium stems, while the alumina coating was on chromium-cobalt-molybdenum stems. The investigation was carried out by means of micro-area X-ray diffractometric analyses and microdiffractometric analyses at the bone-implant interface. Moreover, the coating before and after implantation was analysed by means of the conventional powder X-ray diffractometric technique. This study demonstrated that 1 yr after implantation in animals the newly formed bone adjacent to the HA-coated hip prosthesis stems was mineralized as much as the pre-existing bone, while 24-64 months after surgery in humans the newly formed bone close to the alumina-coated hip prosthesis stems showed a lamellar and Haversian structure strongly demineralized, probably due to the release of aluminum ions from the alumina covering. The authors conclude that the X-ray diffraction allows the evaluation of the structural modifications of the ceramic coating, the bone formation rate close to the coating and the chemical nature of the particles released from the coating.
Plasmid pCT is present in essentially all isolates of Chlamydia trachomatis and may encode factors important for survival in the natural environment. However, no pCT-associated phenotype has been described so far. With the purpose of investigating the possibility of a role of pCT in C. trachomatis pathogenicity we examined the expression of an ORF (ORF3), potentially encoding a 28 kDa polypeptide (pgp3). Analysis of RNA extracted from chlamydia-infected Vero cells detected ORF3-specific transcripts, from 20 h post-infection onwards, mainly as discrete RNA species of 1390 nucleotides comprising the downstream ORF4 sequence. ORF3 DNA was cloned and expressed in Escherichia coli as a 39 kDa fusion protein (MS2/pgp3). Antibodies raised against purified MS2/pgp3, specifically recognized a 28 kDa protein on Western blots of protein from purified chlamydial elementary bodies (EBs). The same antibodies detected chlamydial inclusions in methanol-fixed infected cells by immunofluorescence. Western blot analysis of EBs extracted with 2% Sarkosyl, showed that a large proportion of the 28 kDa antigen is associated with the detergent-insoluble ('membrane') fraction. Antibodies recognizing pgp3 epitopes were detected in sera from patients with chlamydial infections, but not in sero-negative control sera. The finding support the hypothesis that pCT may provide a function related to chlamydial cell physiology.
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In Elodea densa leaves, ethanol up to 0.17 m stimulates H(+) extrusion activity. This effect is strictly dependent on the presence of K(+) in the medium and is suppressed by the presence of the plasmalemma H(+)-ATPase inhibitor vanadate. Stimulation of H(+) extrusion is associated with (a) a decrease in cellular ATP level, (b) a marked hyperpolarization of transmembrane electrical potential, and (c) an increase in net K(+) influx. These results suggest that ethanol-induced H(+) extrusion is mediated by an activation of the plasma membrane ATP-dependent, electrogenic proton pump. This stimulating effect is associated with an increase of cell sap pH and of the capacity to take up the weak acid 5,5-dimethyloxazolidine-2,4-dione, which is interpretable as due to an increase of cytosolic pH. This indicates that the stimulation of H(+) extrusion by ethanol does not depend on a cytosolic acidification by products of ethanol metabolism. The similarity of the effects of ethanol and those of photosynthesis on proton pump activity in E. densa leaves suggests that a common metabolic situation is responsible for the activation of the ATP-dependent H(+)-extruding mechanism.
Sera from a sample of healthy Italian people were tested in an indirect immunofluorescence assay (IFA) for reactivity to a Human Herpesvirus-6 (HHV-6) strain called CV, isolated from a baby with exanthem subitum (Portolani et al., 1990). Seropositivity values of 83.78%, 92.68% and 63.64% were found in subjects aged 3 months-6 years, 6-18 years and over 18 years respectively. Sera from cordal blood, sera from subjects with evidence of active infection by Cytomegalovirus (CMV) or by Epstein-Barr virus (EBV), sera from seropositive adults to Human Immunodeficiency Virus type 1 (HIV) were also investigated for antibodies to the same HHV-6 strain. Values of antibody incidence and antibody content to HHV-6 in these groups of sera were generally higher than in the other groups. HHV-6 reinfections of both endogenous and exogenous origin and antibody cross-reactivity were considered among the reasons of this increase. HHV-6 seropositivity values in healthy Italian people and in people from different countries were also discussed in the light of the antigenic characteristics of the HHV-6 strains used and of the different test conditions.
8 femoral heads removed in 4 patients operated on by bilateral total hip replacement for osteoarthritis were evaluated. 3 patients were treated with Calcitonin between the first and the second operation. X-ray powder diffractometry analysis showed an improvement of bone crystallinity in the Calcitonin treated patients.
Authors performed SEM and EDS analyses in a cemented removed knee prosthesis demonstrating the average values of mineral elements in the bone surrounding the prosthesis. The composition of the metallic prosthesis surface in different microareas was also studied.