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Biomedical subjects

R Cattaneo

Publications and source records attributed to R Cattaneo.

At least 127 records · Page 7Linked to original sources
PubMed1992

The treatment of infected nonunions and segmental defects of the tibia by the methods of Ilizarov.

Circular external fixation using the Ilizarov apparatus combined with internal bone transport or compression-distraction techniques were used to treat 28 patients with infected nonunions or segmental bone loss of the tibia. There were 22 males and six females with an average age of 34 years (range, 17-58 years). Six of 28 patients had infected tibial nonunions associated with hemicircumferential bone loss. These tibiae were treated by anterior hemicircumferential corticotomy and partial bone fragment internal transport. Fifteen of the remaining 22 patients had an average of 4 cm of segmental bone loss (range, 2-7 cm). Seven patients without shortening or defect had infected nonunions associated with extensive diaphyseal sequestrae. These nonunions were treated by en bloc resection of the diaphyseal shaft and internal bone transport. All patients healed their infected extremities without the addition of cancellous bone graft, microvascular fibular, or soft-tissue grafting. Preoperative shortening was present in 13 of 28 patients. Regenerate new bone formation averaged 6 cm (range, 1.5-22 cm). Postoperative antibiotics were not administered in 21 of 28 patients. In seven patients, antibiotics were given for ten days after en bloc resection of the diaphyseal sequestrae. Equal limb length was maintained in 21 extremities, within 1 cm in five tibiae and less than 3 cm in two tibiae. Functional results were good to excellent in 21, fair in six, and poor in one. The application of Ilizarov techniques to diaphyseal infected nonunions and segmental defects is very encouraging. It may prove to be an excellent technique for future management of resistant diaphyseal infections of bone.

Adolescent↗
PubMed1991

Restricted expression of T cell receptor V beta but not V alpha genes in rheumatoid arthritis.

Synovial fluids of patients with rheumatoid arthritis contain activated T lymphocytes that may play an important role in the pathogenesis of the disease. Previous studies have suggested that the T cell receptor (TcR) repertoire of these cells is restricted, reflecting in vivo selection of a limited number of T cell specificities at the site of inflammation. To characterize better these T cell populations we used the polymerase chain reaction technology to estimate the proportion of TcR alpha and beta RNA containing any particular V elements from transcripts directly isolated from the synovial fluid cells and from peripheral blood mononuclear cells of three patients with rheumatoid arthritis. Our data show that, in contrast to peripheral blood mononuclear cells, synovial fluid T cells expressed only few V beta transcripts, one of which was overrepresented in two patients. Peripheral and joint fluid T cells, on the other hand, appeared to express the same set of non-restricted V alpha elements. These results suggest that a major antigen associated with the pathogenesis of rheumatoid arthritis may interact selectively with the V beta component of the TcR.

Arthritis, Rheumatoid↗
PubMed1991

Measles virus phosphoprotein retains the nucleocapsid protein in the cytoplasm.

Measles virus (MV) proteins were efficiently expressed in COS and Vero cells from vectors based on the strong cytomegalovirus enhancer-promoter and the simian virus 40 origin of replication. When expressed alone, nucleocapsid protein (N) migrates predominantly into the nucleus whereas phosphoprotein (P) is located in the cytoplasm. Coexpression of N and P proteins results in retention of the N protein in the cytoplasm, as seen also in infected cells. The retention of N protein is due to specific interactions with the P protein since coexpression of N with either the matrix or the hemagglutinin protein had no effect. Mapping of the regions of N-P interactions on P protein revealed that the carboxy-terminal 40% of P was sufficient for specific binding to N; however, the carboxy-terminal 60% of P was required for retention of N in the cytoplasm. Thus, the V and C proteins encoded within the first half of the P gene are not involved in the cytoplasmic retention of N protein. N protein might be fortuitously targeted to the nucleus as a result of its many basic amino acids, presumably destined to interact with the MV genome. However, this set of experiments has allowed to analyze in vivo the interactions between the N and P proteins.

Animals↗
PubMed1991

Functional and nonfunctional measles virus matrix genes from lethal human brain infections.

Subacute sclerosing panencephalitis (SSPE) is a lethal disease induced by the persistence of measles virus in the human brain. In many SSPE cases, the viral matrix (M) protein cannot be detected; in others, M proteins of the expected size are found and sequence analysis of M cDNAs has confirmed that the reading frames are intact, showing only several missense mutations. To determine whether these alterations result in nonfunctional proteins, we have replaced the M gene of an infectious full-length genomic cDNA (from vaccine strain Edmonston) with different M genes derived from four patients with SSPE. One of the SSPE M genes tested proved to be functionally competent, giving rise to a virus yielding titers similar to those of viruses containing the M gene from control lytic strains. The other three SSPE M genes were not functionally competent in the same test. In all three cases, the inactivating changes resided in the carboxyl-terminal half of the M protein, as shown by the exchange of either of the two genes halves. In summary, mutational M gene alterations, which either prevent synthesis of M protein altogether or only allow synthesis of nonfunctional M protein, have been detected by us and by others in 9 of 10 SSPE cases. The one functional M gene appears to be an exception to the rule, indicating that M gene alteration might not be an absolute requirement for disease development.

Animals↗
PubMed1991

[Prevalence of reactions to drugs in 251 patients with urticaria-angioedema syndrome].

We studied 251 outpatients affected by chronic and acute urticaria-angioedema syndrome, triggered or exacerbated by drugs, to evaluate the prevalence of adverse reactions to each pharmacological group. Among these patients, 134 (53.4%) presented one or more adverse reactions to a single drug: 100 (74.7%) reacted to NSAIDs, 33 (24.7%) to antibiotics and 1 to B vitamin complex. The remaining 117 patients (46.6%) presented adverse reactions to more than one drug. Considering the patients all together, 123 (49%) had adverse reactions to ASA, 116 (46.2%) to pyrazones, 65 (25.9%) to antibiotics, 26 (10.3%) to NSAIDs different from ASA and pyrazones. In our experience, according to other reports, there is a greater frequency of drug reactions to NSAIDs vs other drugs. ASA is the more frequently involved drug.

Angioedema↗
PubMed1991

Management of fibular hemimelia using the Ilizarov method.

A comprehensive program for the correction of fibular hemimelia and associated deformities using the Ilizarov external fixator has been developed at the author's institution. This management involves classification of the deformity (type I, II, or III) and single or staged procedures with the goal to provide a stable plantigrade foot with correction of leg deformity and length discrepancy. The use of the Ilizarov external fixator allows correction of multiple deformities simultaneously. The initial experience with this correction with satisfactory functional and radiographic results in most patients. Final conclusions regarding treatment outcome will not be possible until a significant number of patients reach skeletal maturity.

Adolescent↗
PubMed1990

Messenger RNA editing and the genetic code.

Messenger RNA editing is defined as a process leading to predetermined modifications of the coding region of a primary gene transcript. By this definition, splicing processes are special forms of editing; however, they are not dealt with in this review. Editing processes different from splicing have been defined in mammalian cells, in RNA viruses, and in mitochondria of trypanosomes, higher plants and vertebrates. These post- or co-transcriptional processes involve addition, deletion, or modification-substitution of nucleotides, and represent previously unrecognized mechanisms for altering the coding potential of a gene and for modulating gene expression.

Animals↗
PubMed1990

Infectious measles virus from cloned cDNA.

The study of measles virus (MV) and of negative strand RNA viruses in general has been hampered by the lack of an experimental system for genetic manipulation. Here we describe a procedure for generating infectious MV from cloned MV cDNA. First we assembled a genetically marked DNA copy of the MV genome in plasmids, under the control of phage T3 or T7 promoters, allowing production of transcripts almost identical to the MV genome or antigenome. Incubation of these linearized plasmid DNAs with the appropriate phage polymerase and only two ribonucleoside triphosphates yielded committed transcription complexes. Microinjection of these complexes into the cytoplasm of helper cells which provide the proteins necessary for MV genome encapsidation and transcription/replication, reproducibly give rise to lytic MVs. The transcripts of one of these viruses were analysed by sequencing after reverse transcription followed by DNA amplification, and found to contain the genetic tags. The described procedure permits the analysis of a negative strand RNA virus with the same genetic tools previously applicable only to positive strand RNA viruses and retroviruses.

Base Sequence↗
PubMed1990

Prevalence, clinical, and laboratory features of thrombocytopenia among HIV-infected individuals.

Prevalence and clinical features of human immunodeficiency virus (HIV)-related thrombocytopenia have been investigated among a random population of 657 anti-HIV-positive individuals. A platelet count below 100 X 10(9)/liter was detected in 72 patients (10.9%). Compared with anti-HIV-positive controls with normal platelets, a significantly higher prevalence of males (p less than 0.02) and of intravenous drug abusers (p less than 0.02) as well as a higher frequency of patients with advanced HIV-related disease (p less than 0.001) were detected among thrombocytopenic patients. Those patients whose thrombocytopenia was associated with neutropenia and/or anemia (14 cases, 2.1%) clearly differed from patients with isolated thrombocytopenia (IT) (58 cases, 8.8%) since they belonged to the more advanced groups of the CDC classification of HIV-related disorders, had lower CD4-positive lymphocyte counts, a higher frequency of cutaneous anergy, and less persistent thrombocytopenia. In the cohort of patients with persistent IT (47 cases), no single epidemiological or clinical data proved to correlate with the severity of thrombocytopenia. They did not differ significantly from anti-HIV-positive controls in their distribution among CDC groups, but the total lymphocyte and the CD4-positive lymphocyte counts were significantly lower in IT patients belonging to CDC group II (p less than 0.05 and p less than 0.02, respectively) and III (p less than 0.01 and p less than 0.005, respectively) compared with CDC group-matched controls; after a median followup of one year, the two cohorts showed similar rates of progression to CDC Group IV.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Decreased number of peripheral blood CD4 + CD29+ lymphocytes and increased in vitro spontaneous production of anti-DNA antibodies in patients with active systemic lupus erythematosus.

Flow cytometric 2-color analysis of peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE) showed a reduction of relative and absolute number of CD4+ CD29+ cells compared to matched healthy individuals. This abnormality was more marked in patients with active/very active disease. Absolute number of CD4+ CD29+ cells was negatively correlated with spontaneous anti-DNA Ig production that we demonstrated to be a laboratory index strongly correlated with a clinical disease activity score. A decrease of the percentage of CD8+ CD29+ lymphocytes in patients with active disease was also observed.

Adult↗
PubMed1990

[Sensitization to ethylene oxide: a possible cause of reactions in hemodialysis patients].

147 hemodialyzed patient were studied for the presence of allergic reactions related to the dialytic treatment. Total IgE and specific IgE to common inhalants, ethylene oxide and phthalic anhydride were determined in all patients. The same determinations were also performed in two control groups. Specific IgE to ethylene oxide were detected in 7 sera. Among these 6 had a high total IgE level and 2 had a positive Phadiatop. Only 3 among the 7 positive patients had adverse reactions related to the hemodialysis (one suffered from itching, one from urticaria and the third from angioedema and hypotension). The resolution of the symptoms was obtained utilizing a gamma-rays sterilized filter. Therefore ethylene oxide sensitization may be a cause of some problems during hemodialysis. We couldn't find a relationship between atopic status and sensitization to ethylene oxide in as much in only 2 out of 7 patients sensitized to ethylene oxide, specific IgE to common inhalants were detected.

Aged↗