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Biomedical subjects

A Oliva

Publications and source records attributed to A Oliva.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Clinical evaluation of the tolerability of imipenem in the treatment of postoperative infections in oncologic surgery].

Fifteen neoplastic patients were examined in a pilot study to evaluate side effects and efficacy of imipenem (three doses of 500 mg/die, e.v.) as monochemotherapy of post-operative septic complications. These infections included: two wound infections, nine lung infections, one case of mixed infection (spread purulent peritonitis associated with lung infection), one case of urinary tract infection, one chronic suppurative malleolar ulcer in a patient with Kaposi's sarcoma, and one case of mediastinitis due to oesophageal perforation during endoscopic dilatation. Antibiotic treatment was successful in 14 patients, apyrexia being reached within 2nd to 13th day of treatment (median: 4th day) with negative microbiologic and radiologic assessment; only in the patient with chronic suppurative malleolar ulcer, notwithstanding apyrexia, microbiologic culture indicated the persistence of a pre-treatment pathogen (P. mirabilis). Side effects included only a slight and transient increase of serum transaminases in one patient.

Adult↗
PubMed1989

Sonographic appearances of hemangiomas of skeletal muscle.

The sonographic findings observed in seven patients with muscular hemangiomas were reviewed. An intramuscular mass (size range of 1.5 to 10 cm) was seen in all cases. Five lesions had oval shapes and smooth margins; two had irregular shapes and borders that were not clearly defined. Hyperechoic structure was noted in three lesions; two were hypoechoic; two had heterogeneous echo patterns. Three other muscular hemangiomas (two hyperechoic, one heterogeneous) are reported in the sonographic literature. Therefore, from the literature and from our own observations of hemangiomas, a hyperechogenic mass is the most common sonographic presentation of these tumors. However, there is not a specific sonographic appearance to muscular hemangiomas and other diagnostic tests are needed to establish the diagnosis.

Adolescent↗
PubMed1988

Chromatographic and radioimmunological methods for the determination of 5'-deoxy-5'-methylthioadenosine in biological fluids.

Two specific methods for the determination of 5'-deoxy-5'-methylthioadenosine (MTA) in biological samples have been developed. The chromatographic procedure requires a preliminary step on a phenylboronate column to remove non-cis-diol compounds. The sample is then analysed using a high-performance liquid chromatography system equipped with a reversed-phase column. 5'-Deoxy-5'-methyl-thio[2-3H]adenosine with high specific activity was synthesized and employed as an internal standard. An alternative radioimmunoassay (RIA) procedure has also been developed. The RIA method is based on competition between the unlabelled thio-ether and 3H-labelled MTA for the binding to a specific antiserum. Anti-MTA antibodies were obtained from rabbits immunized with the nucleoside covalently linked to carrier proteins. Both the chromatographic and RIA procedures gave identical results when employed to determine MTA in human urine.

Adenosine↗
PubMed1988

High-performance liquid chromatographic determination of a naturally occurring xylosyl thioether, 9-[5'-deoxy-5'(methylthio)-beta-D-xylofuranosyl]adenine.

A high-performance liquid chromatographic (HPLC) method for the separation and purification of 9-[5'-deoxy-5'(methylthio)-beta-D-xylofuranosyl]adenine (xylosyl-MTA), a naturally occurring analogue of 5'-deoxy-5'-methylthioadenosine (MTA), has been developed. The compound was purified from perchloric extracts of biological samples by reversed-phase HPLC on an Ultrasil ODS RP-18 column. Isocratic elution resulted in a complete separation between the xylosyl thioether and MTA. The determination of xylosyl-MTA in the nudibranch mollusc Doris verrucosa was also performed. Its concentration ranged from 330 to 380 nmol/g, considerably exceeding the cellular levels of MTA.

Adenosine Deaminase↗
PubMed1988

An acute light and electron microscopic study of ultraviolet 193-nm excimer laser corneal incisions.

The 193-nm ultraviolet beam from an argon fluoride excimer laser was focused on the corneas of rabbits to produce incisions of the type necessary for radial keratotomy. The energy densities used were in two ranges, 1.0 to 2.1 J/cm2 per pulse and 200 to 700 mJ/cm2 per pulse. The eyes were enucleated and fixed for histologic and electron microscopic examination immediately after exposure. Structural analysis of the higher energy density exposures showed ridging on the surface of the cornea, micro-pitting on the stromal surface inside the cut, and denudation of the endothelium under the ablation zone. The lower energy density incisions did not exhibit significant surface ridging or endothelial cell loss but did exhibit significant stromal swelling during the laser exposure thus making it difficult to produce incisions of a precisely controlled depth. Beam profile measurements and infrared thermal measurements of the cornea surface during laser exposure were made.

Animals↗
PubMed1988

Two cases of occipital infarction following cardiac catheterization.

Transient visual disturbance following cardiac catheterization has been regarded as a benign and transient complication. We describe two cases of computed-tomography-documented occipital infarction after cardiac catheterization that emphasize a complication more serious than previously thought.

Aged↗
PubMed1988

Myelolipoma and endocrine dysfunction.

Myelolipoma is an uncommon benign tumor of which the pathogenesis is unknown. It is rarely associated with endocrine disorders. We present a case of a myelolipoma in conjunction with congenital adrenal hyperplasia secondary to 21-hydroxylase deficiency. Nine previously reported cases of myelolipoma associated with endocrine dysfunction are reviewed with potential correlation of the hormonal imbalance to pathogenesis.

Adrenal Gland Neoplasms↗
PubMed1987

The transcriptional efficiency of clustered tRNA genes is affected by their position within the cluster.

The transcription of a mouse genomic segment containing four tRNA genes, coding for a tRNA(Ala), a tRNA(Ile), a tRNA(Pro) and a tRNA(Lys), has been studied in a HeLa cell extract, demonstrating that differences among their transcriptional efficiencies are evident using as templates either the natural cluster or an equimolecular mixture of the four isolated genes. Nevertheless, the structure of the cluster influences the transcriptional efficiency of the clustered genes. In fact, a cis-acting inhibitory sequence has been located at about 400 bp downstream of the tRNA(Pro) coding sequence. Moreover rearrangements of the reciprocal position of the various tRNA genes within the cluster results in significant changes in the transcriptional rates of the individual transcriptional units.

Animals↗
PubMed1986

Structure and in vitro transcription of tRNA gene clusters containing the primers of MuLV reverse transcriptase.

Three genes coding for mouse tRNAPro have been isolated from a genomic library and characterized both structurally and functionally. Two of these (tPro52 and tPro53) code for the tRNA primer of reverse transcriptase of MuLV. The third one (tPro51) shows several differences (mutations and deletions) that probably prevent the folding of the matured transcript into the cloverleaf structure, and is therefore a pseudogene. This pseudogene gives rise to a RNA transcription product in vitro. tPro52 is clustered with a tRNALys gene and with a tRNAAla gene, which is strongly homologous to the rat identifier repeated sequence. tPro53 is clustered with a tRNAAsp and a tRNAGly gene. Other tRNA-hybridizing sequences are present in the lambda clones that contain tPro51 and tPro53.

Anticodon↗
PubMed1986

Entamoeba histolytica: specific antigen recognized by a monoclonal antibody.

Specific antigenic determinants on the membrane surface of Entamoeba histolytica that distinguish it from other Entamoeba species were demonstrated. Evidence for these antigenic determinants was obtained with a monoclonal antibody to E. histolytica which showed not only specificity but also sensitivity as demonstrated in enzyme linked immunosorbent assay. Immunofluorescence microscopy showed that the monoclonal antibody recognized an epitope present on the membrane surface of E. histolytica trophozoites. The epitope detected by the monoclonal antibody was present in three components of different molecular weight. These components may have a common precursor or may be the result of enzymatic degradation under the conditions tested.

Animals↗
PubMed1982

Enhanced resistance to Nocardia brasiliensis infection in mice depleted of antigen-specific B cells.

This study deals with the roles of T and B cells in Nocardia brasiliensis infection in mice. Nocardia injected into the animals' footpads caused inflammatory responses and mycetomas in situ, resulting in granulomatous lesions of subcutaneous tissues and eventual bone destruction. These clinical features resemble those of humans infected with Nocardia. The effect, if any, of antibody was studied by passively transferring anti-Nocardia serum into either immunologically normal or T-deficient infected mice. Such transfers had no protective function in either group. To the contrary, the antibody seemed to favor infection and worsen bone disease compared to that in mice not given antibody. Furthermore, passive transfer of the antibody along with injection of Nocardia coated with the antibody magnified the severity of subsequent symptoms. Although these experiments ruled out any role for antibody in protection from Nocardia, they did not directly prove T cell participation in such resistance. Therefore, the role of T cells during Nocardia infection was examined further by transferring spleen cells depleted of B lymphocytes bearing receptors for a Nocardia extract (NE). Lethally irradiated mice reconstituted with a population depleted of NE-specific B cells totally lacked the ability to form antibodies to NE; however, they mounted effective delayed-type hypersensitivity reactions and completely controlled their Nocardia infection, establishing the importance of cell-mediated immunity in halting this disease process.

Animals↗