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Biomedical subjects

G Bertoni

Publications and source records attributed to G Bertoni.

At least 109 records · Page 6Linked to original sources
PubMed1985

A chemiluminescent assay for mycoplasmas in cell cultures.

A chemiluminescent assay for the detection of mycoplasma contamination of cell cultures is described. Cells (and supernatant) derived from mycoplasma-contaminated cultures stimulate a burst of luminol-dependent chemiluminescence in cell suspensions containing phagocytic effector cell types. The assay conditions for spleen cells, human and bovine polymorphonuclear leucocytes as the responder or indicator cells have been optimized. The chemiluminescent assay can be utilized for both monolayer and suspension cell cultures and is more sensitive than colony formation on agar plates and electron microscopy. Results are obtained within 3-5 h including the time required for the preparation of the indicator cells. CL can be measured in the tritium window of standard liquid scintillation spectrometers after switching off the coincidence circuit.

Cells, Cultured↗
PubMed1985

Impaired contrast sensitivity in diabetic patients with and without retinopathy: a new technique for rapid assessment.

A simple technique is described for assessing the sensitivity of the human visual system to gratings at threshold contrast. The technique has advantages for clinical use in that it is (1) inexpensive, (2) quick to administer, (3) portable, and (4) relatively free from bias. Forty-two diabetic patients and 84 normal controls have been tested. Fifteen diabetic patients (6/20 with retinopathy and 9/22 without) had test scores more than two standard deviations below the norm for age-matched controls.

Adolescent↗
PubMed1984

Antibody-free target cells stimulate chemiluminescence in polymorphonuclear leukocytes: an artifact due to mycoplasma contamination.

The generation of toxic oxygen species represents a significant mechanism in the killing of microorganisms and antibody-coated cells by phagocytic cells. We have investigated the possibility that antibody-free target cells stimulate reactive oxygen generation in polymorphonuclear leukocytes (PMNL) using the measurement of luminol-dependent chemiluminescence (CL). It was found that the induction of CL consistently correlated with a mycoplasma contamination of the target cells. Free mycoplasma organisms of two species found frequently as contaminants in cell culture also stimulated CL. Upon artificial infection with mycoplasma, cultured cells acquired the capacity to evoke CL generation in PMNL. Our experiments strongly suggest that the induction of reactive oxygen generation by antibody-free target cells is an artifact due to mycoplasma contamination of the target cell cultures.

Animals↗
PubMed1984

Induction of chemiluminescence during interaction of tumoricidal effector cell populations and tumor cells is dependent on the presence of mycoplasma.

A variety of host cells, such as activated macrophages, natural killer (NK) cells, and polymorphonuclear leukocytes (PMNL), are cytotoxic for an array of non-antibody-coated tumor cells. Because such effector cells appear to use oxygen-dependent mechanisms to effect tumor cell destruction in certain systems, the possibility of an involvement of toxic oxygen species has been considered. To investigate whether interaction of effector cells with neoplastic cells induces the generation of reactive oxygen species, resting and activated rat macrophages and rat spleen cells (as a source of NK activity) were exposed to viable tumor cells of varied origin, and chemiluminescence was monitored. This sensitive indicator of reactive oxygen generation was stimulated only when tumor cells or culture supernatants were contaminated with mycoplasma. Mycoplasma-free tumor cells and culture supernatants were in no case able to trigger chemiluminescence in any of these effector cell populations. On the other hand, tumor targets were equally susceptible to killing by effector cells irrespective of whether mycoplasma were present. The data suggest that generation of chemiluminescence during interaction of natural cytotoxic cells and neoplastic cells is an artifact and that reactive oxygen species do not function as an effector mechanism in antibody-independent natural killing effected by activated macrophages and NK cells.

Animals↗
PubMed1983

Vaginal molds for intracavitary curietherapy: a new method of preparation.

A new method of preparing vaginal molds for afterloading intracavitary brachytherapy is described. Our technique makes it possible to obtain the most accurate individualization of therapy as far as dose distribution is concerned by taking into account the patient's anatomy and target volume.

Brachytherapy↗
PubMed1982

Coagulation and platelet activation after retinal vein occlusions.

The role played by coagulation and platelet activation in the pathogenesis of retinal vein occlusions (RVO) has been evaluated by measuring beta-thromboglobulin (B-TG), circulating platelet aggregates (CPA), thromboxane B2 (TxB2) and fibrinopeptide A (FPA) in 25 patients less than 40 years old, investigated after the acute phase of RVO. FPA nd B-TG were significantly higher than in healthy subjects; CPA and TxB2 were not different. These abnormalities, found in patients free from apparent generalized vascular disease, suggest that a thrombophilic state characterized by coagulation and platelet activation is present in a high proportion of young patients with RVO.

Adolescent↗
PubMed1981

[Retinal vascular changes and haemostatic function in young patients (author's transl)].

Haemostatic function was studied in 40 patients between one and 12 months from the occurrence of retinal vein occlusion (RVO); 25 patients aged 40 years, or less and 15 were more than 45 years old. The following tests were performed : plasma beta-thromboglobuline (beta-TG) fibrinopeptide A (FpA), PTT, spontaneous in vitro platelet aggregation (SpA), circulating platelet aggregates (CPA), platelet retention (PR) to glass beads, serum thromboxane B2 (TxB2). In the group of older patients, there was a significant increase of beta-TG, FpA, PR, SPA, TxB2, and a reduction in the PTT. CPA was not significantly changed. In the group of younger patients (less than 40 yrs) only FpA and beta TG levels showed significant differences from the control group of age-matched healthy subjects. These findings suggest that the alterations present in older patients are likely to be secondary to generalized vascular damage, whereas a state of activation of the coagulation system appears to be present in younger patients with RVO.

Adult↗
PubMed1980

[Ocular complications in patients undergoing long-term hemodialysis and renal transplants from cadavers].

In 36 subjects in chronic hemodialysis treatment and in 36 patients with a renal transplant, well functioning for more than one year, the ocular complications related to the specific form of treatment were evaluated and compared. In the group of the dialyzed subjects ocular pathology was composed by: lens opacities in 9 cases, corneal calcifications in 7 cases, hypertensive fundus in 8 cases. In no patient these lesions produced measurable visus reductions. In the transplant group ocular pathology was composed by: lens opacities in 28 patients, hypertensive fundus in 7 and intraocular hypertension in one. One case of herpes cheratytis and one case of endophtalmytis have also been observed. In 9 patients these lesions produced a remarkable visus reduction. In conclusion renal transplantation shows a greater incidence of ocular complications if compared to hemodialysis. This situation has not important consequences on the rehabilitation of the transplanted subject for the possibility of surgical correction of the cataract.

Adolescent↗
PubMed1979

Erythrocyte unsaturated fatty acid test (E-UFA test): a biological test to detect optic neuritis as initial feature of multiple sclerosis.

Retrobulbar optic neuritis, though suspicious is not always considered as a possible onset of MS. For this reason we submitted to the E-UFA (erythrocyte unsaturated fatty acid) test, 41 subjects who suffered from one or several episodes of retrobulbar optic neuritis with no other neurological signs. The test was positive in 14 subjects (34, 1%).

Adolescent↗
PubMed1979

Unexpected giant "V" waves during pulmonary artery catheterization.

Two cases of catheterization of the pulmonary artery, in which the hemodynamic findings were very different from the initial clinical diagnosis, are presented. The importance of verifying the adequate position and motion of the pulomonary artery catheters with two consecutive chest x-rays is discussed. In particular, attention is brought to the possible misinterpretation that occurs in patients with very elevated pulmonary artery mean pressure.

Blood Pressure↗
PubMed1978

Critical evaluation of sampling and gas chromatographic analysis of halocarbons and other organic air pollutants.

Problems connected with the analysis of ultra-trace amounts of halocarbons in air are discussed in terms of trapping procedures, interferences and chromatographic columns. A suitable column for the qualitative and quantitative analysis of C1-C2 halocarbons is described, and examples of applications are given. High-efficiency micropacked columns have been used for the analysis of hydrocarbons in the open atmosphere.

Air Pollutants↗
PubMed1978

Adverse effects of calcium administration. Report of two cases.

Calcium chloride, 7 mg/kg, and calcium gluconate, 20 mg/kg, were administered to patients with low or low-normal levels of serum ionized calcium. Both patients had low blood pressure and cardiac index, and did not respond to digitalis, volume expansion, and beta-adrenergic stimulation with dopamine. Administration of calcium rapid increase of serum ionized calcium levels, decrease of serum potassium levels, and development of severe cardiac arrhythmias. Atrioventricular dissociation and further fall of cardiac index and blood pressure were common features of both cases. Administration of exogenous calcium can cause severe complications, even when theoretically indicated.

Adult↗