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Biomedical subjects

A Esposito

Publications and source records attributed to A Esposito.

At least 73 records · Page 4Linked to original sources
PubMed1990

Unchanging cardiac activity while increasing respiratory activity at the start of exercise in man: a beat-by-beat analysis by means of the impedance cardiography method.

Both respiratory and cardiodynamic parameters were analyzed (the latter non invasively by means of a computerized impedance cardiograph) in 6 subjects at the start of voluntary dorsal ankle flexions. Increased mean inspiratory flow with a slow reduction in end tidal PCO2 was shown in the breath following the start of movements, and these findings indicate the nervous origin of this hyperventilation. Within the same breath, left cardiac output, stroke volume and ventricular ejection time remained unchanged, and the same is true of heart rate and ventricular performance indexes depending on both the first derivative of the base thoracic electrical bioimpedance and on the mean left ventricle ejection flow, as well as in the systemic venous return index depending on the basal value of the thoracic impedance. These results, indicating that no cardiodynamic intervention in the neurogenic hyperventilation was seen, show that nervous stimuli elicited at the start of voluntary exercise may exert a direct action on respiratory control structures.

Adult↗
PubMed1990

[Thrombocytopenia with bilateral absence of the radius (TAR syndrome). Reports of 2 clinical cases].

Thrombocytopenia with bilateral absent radii (TAR syndrome) is a hereditary condition with a recessive autosomic character. It is characterised by a series of hematological, skeletal and cardiac alterations, and also by various clinical manifestations. The frequency of this syndrome is very low. During the first months of life, prognosis is related to the severity of hemorrhage, but it improves after two years. Diagnosis is at times complex owing to the similarity between this and other syndromes. Therapy, especially during the first year of life, is based on blood transfusion. The paper describes clinical findings in two subjects admitted to the Istituto di Clinica Pediatrica. The two cases presented diverse degrees of hematological and skeletal involvement and followed different clinical evolutions.

Female↗
PubMed1989

Effectiveness of steroid therapy in different stages of membranous nephropathy.

The published studies on histological staging and response to steroid therapy of membranous glomerulonephritis are not consistent. We analysed data from 25 adult patients with stage I (group 1, n = 7) and stage II (group 2, n = 18) disease. The interval between clinical onset and admission was similar in the two groups. At admission all patients had normal creatinine clearance; proteinuria averaged 5.4 +/- 4.0 in group 1 and 9.0 +/- 4.0 in group 2 (g/day per 100 ml GFR). All patients received 6 months steroid therapy (months 1-2, 1 mg/kg b.w. per day; month 3-5: 0.65 mg/kg b.w. e.o.d.; month 6, tapering). After this cycle of steroid therapy, proteinuria declined by 84% in group 1 (five patients being in partial remission, i.e. 0.4-2 g/day, and two patients in complete remission, i.e. less than or equal to 0.3 g/day) and by 47% in group 2 (two patients being in complete remission and six in partial remission). Only 1 patient in group 1 relapsed with nephrotic proteinuria after 36 months, and renal function was still normal in all patients at the most recent follow-up (59 +/- 32 months). In contrast, 14 patients in group 2 had nephrotic syndrome and seven renal insufficiency at the most recent follow-up. We conclude that short-term steroid therapy is effective only in patients with early membranous changes.

Adolescent↗
PubMed1989

[Software for record reporting and filing with the personal computer].

During the past four years the authors have been gaining experience in reporting radiological examinations by personal computer. Today they describe the project of a new software which allows the reporting and filing of roentgenograms. This program was realized by a radiologist, using a well known data base management system: dBASE III. The program was shaped to fit the radiologist's needs: it helps to report, and allows to file, radiological data, with the diagnostic codes used by the American College of Radiology. In this paper the authors describe the data base structure and indicate the software functions which make its use possible. Thus, this paper is not aimed at advertising a new reporting program, but at demonstrating how the radiologist can himself manage some aspects of his work with the help of a personal computer.

Database Management Systems↗
PubMed1988

Effects of sodium azide on sea urchin embryos and gametes.

Sodium azide (SA) was tested on sea urchin embryos and gametes (Paracentrotus lividus). Developing embryos were exposed to SA (10(-6) to 10(-3) M) up to pluteus larval stage, or for shorter intervals before or after hatching. Developmental defects in SA-exposed embryos consisted mainly of gut abnormalities, without any detectable differences between pre- or post-hatch-exposed embryos. SA-induced damage to gut was exerted during gastrulation, as evident by lectin binding of extracellular matrix. No mitotic damage was observed in SA-exposed embryos, nor could pH-related variations be detected in SA-induced embryotoxicity at pH's ranging from 8 to 6. Concurrently, no effect ensued in the exposure of unfertilized eggs to SA (10(-5) to 10(-2) M) both in terms of fertilization success and of offspring quality. When sperm were suspended in filtered seawater at pH's ranging from 8 to 6, and SA levels ranging from 10(-5) to 10(-2) M, fertilization success of SA-exposed sperm appeared to be modulated by pH, by displaying three distinct dose-response trends at pH 8, 7, or 6. The consequences of sperm pretreatment on offspring quality failed to show any significant SA-induced changes on larval malformations or mortality, while confirming the previously reported pH-induced increase of developmental defects in the offspring of acid-exposed sperm (Pagano et al.: Teratogenesis Carcinogen Mutagen 5:113-121, 1985).

Animals↗
PubMed1988

Echopatterns of the ovarian dermoid tumor.

The authors report the ovarian dermoid echopatterns observed in 189 cases. The ultrasonic key of the diagnosis is a particular "pearly-gray" colour. The early diagnosis by USG gives the Gynecologist some advantages in: a) avoiding the operation in those cases of small mass; b) making a pfammenstiel incision in the surgical operation; c) trying a conservative surgery.

Adolescent↗
PubMed1988

Integrated techniques in the identification of ovarian tumors.

This work is intended to be an effort to standardise the diagnostic iter of ovarian pathology. This protocol is carried out with a clinical examination and later by USG and celioscopy. It tests the management of functional and endometriosic cysts and the other ovarian pathologies.

Clinical Protocols↗
PubMed1986

Sublethal pH decrease may cause genetic damage to eukaryotic cell: a study on sea urchins and Salmonella typhimurium.

Further evidence is reported here of genetic and developmental damage that can be induced by a sublethal pH decrease. The effects of three inorganic acids (HCl, H2SO4, and H3PO4) on embryos and sperm from the sea urchins Sphaerechinus granularis and Paracentrotus lividus were evaluated. In addition, acidification of the medium was tested for spontaneous reversion to His+ prototrophy in Salmonella typhimurium (strains TA97, TA98, TA100, TA102, TA1535) up to toxic levels, by both liquid incubation and agar plate incorporation. The induction of developmental and mitotic abnormalities in S. granularis confirmed our previous observations on P. lividus. Embryotoxicity was exerted in S. granularis more severely by H3PO4 than by HCl or H2SO4 (pH 7 to 6), while the induction of mitotic abnormalities appeared at a pH of less than or equal to 6.5 irrespective of the acids used. By suspending S. granularis or P. lividus sperm in acidified filtered seawater (fsw) and then inseminating the eggs in natural fsw (pH = 8.0), the offspring showed developmental and mitotic abnormalities. Low-pH-induced spermiotoxicity was ruled out in our experiments, since fertilization success of acid-exposed sperm was actually enhanced, as compared to sperm suspended in untreated fsw. The exposure of S. typhimurium to different pH's (ranging from 4 to 9) invariably failed to induce any changes in reversion rates, regardless of the acids (or alkali) being used. These results suggest that extracellular acidification may cause sublethal damage that in turn leads to an impairment of mitotic activity and cell differentiation.

Cells↗
PubMed1985

Nonbactericidal approach to reduce colonization of plaque microflora on teeth in vitro and in vivo.

A non-antibacterial, surface-modifying, perfluorosulfonamidoalkyl ester of phosphorous acid (PSAEP, 1) was adsorbed to saliva-coated hydroxyapatite disks in vitro. Pretreatment of saliva-coated hydroxyapatite beads with different concentrations of 1 markedly reduced the adherence of radiolabeled Streptococcus mutans or Actinomyces viscosus when compared with the buffer-treated controls. Pretreatment of the cells with the compound also significantly impaired their subsequent attachment to saliva-coated hydroxyapatite. In a low surface-to-volume ratio adsorption model, i.e., saliva-coated hydroxapatite disks, pretreatment with 1 for 1 min markedly reduced the adsorption of A. viscosus to the disks. A 1% solution applied topically twice a day significantly (alpha = 0.05) reduced S. mutans-induced smooth and fissure caries in rats. The effect of 0.05% 1 in a rinse was also evaluated on experimental gingivitis in beagle dogs for 6 weeks. A topical application twice a day significantly (alpha = 0.05) reduced plaque-induced gingivitis when compared to that achieved with the placebo. Microbial analyses of the plaque adjacent to gingiva indicated reduction in filamentous medium and large spirochetes as compared with that seen in the pretreatment phase. Collectively, the results show that it is possible to reduce dental caries and gingivitis via an interference with the specific adsorption of organisms to teeth.

Actinomyces↗
PubMed1985

pH-induced changes in mitotic and developmental patterns in sea urchin embryogenesis. I. Exposure of embryos.

The effects of different pH conditions have been investigated on sea urchin larval development following exposure of embryos to controlled, though changing, decreases or increases of seawater pH. The pH of filtered natural seawater was initially adjusted with 1 N HCl of 1 N KOH and then was altered back to its normal values (8.0-8.2) by the exchange with atmospheric CO2 and subsequent carbonic acid equilibrium. During cultures, pH was regularly monitored. When developing embryos were reared in different pH conditions, larval differentiation was sharply affected by an apparently moderate pH decrease, such as 0.5 pH units. However, even pH decreases as small as 0.2 pH units from the normal value showed reproducible damage to embryogenesis. This damage appeared to be early and irreversible, since the exposure of cleaving embryos resulted in more severe developmental defects than exposure of posthatching blastulae. Moreover, mitotic abnormalities were observed following early exposure of embryos to decreased pH. Increased pH, up to 8.6 (approximately 0.5 pH units above normal value), failed to exert any adverse effect on subsequent development. Moreover, an initial pH increase (8.5-8.7) resulted in the final adjustment of culture pH to 8.1-8.2, thus providing optimal conditions for rearing embryos. Two attempts to stabilize culture pH were performed by decreasing gaseous exchanges or by using Tris as a buffering agent. Both approaches appeared to be impractical, thus ruling out any further attempts. The results point out the hazards of acid contamination in restricted bodies of seawater, leading to apparently "moderate" decreases in pH, which can result in severe damage to some marine organisms, both adult and larval forms.

Animals↗
PubMed1985

pH-induced changes in mitotic and developmental patterns in sea urchin embryogenesis. II. Exposure of sperm.

pH decrease and increase were tested for their ability to affect the fertilizing capacity of sea urchin sperm, as well as to induce developmental defects and mitotic abnormalities in the embryos generated by pretreated sperm. Seawater (sw) at different pH values was obtained by mixing acidified (HCl) sw and alkalinized (KOH) sw. Thereafter sperm were exposed to different pHs for a defined time interval, or subjected to inactivation, while suspended in sw at defined pHs, as long as their fertilizing capacity was maintained. The study was carried out over the pH range 5-9; sperm showed optimal fertilizing capacity between pH 6 and 7. Below pH 6 and above pH 8 a drop in the fertilizing capacity was observed, whereas at normal sw pH (8.0-8.2) sperm showed intermediate values. pH decrease in sperm suspension induced a reproducible increase in developmental defects and mitotic abnormalities in the offspring of pretreated sperm. This effect displayed a dose-response relationship, which was most evident for pH ranging from 7 to 8. The effects of decreased pH were detected as well in terms of quantitative changes in mitotic activity, which decreased in embryos generated by sperm exposed to low pH (5-6). The results are consistent with the induction of genetic damage following exposure of sperm to low pHs. This observation suggests a genotoxic action of hydronium ions per se. Another possible explanation for the observed genotoxicity of decreased pH might be based on the pH-dependent activity of several genotoxins present in sw at trace levels.

Animals↗
PubMed1983

Genotoxicity and teratogenicity of diphenyl and diphenyl ether: a study of sea urchins, yeast, and Salmonella typhimurium.

This study was designed to investigate the possible genotoxic and teratogenic actions of diphenyl (DP), diphenyl ether (DPE), and their eutectic mixture, in a comparative approach including different test systems. Two microbial systems and a metazoan model were used: (1) diploid D7 strain of Saccharomyces cerevisiae; (2) Salmonella typhimurium strains TA100, TA98, TA1535, TA1537, TA1538, TA1532, TA2636; and (3) sea urchins (Paracentrotus lividus and Sphearechinus granularis). Both compounds resulted in severe toxicity in all of test organisms at levels greater than or equal to 10(-5) M (approximately 2 ppm). DP caused genetic effects in yeast with and without activating system, while the two chemicals appeared to be ineffective in Salmonella up to toxic levels. The action of DP and DPE on sea urchins resulted in developmental defects and mitotic abnormalities, following exposure of embryos or by pretreatment of sperm or eggs. In this system DPE appeared to be more effective than DP by about one order of magnitude (minimal active concentrations: 10(-5) M vs 10(-4) M). The eutectic mixture, industrially used as a heat transfer medium, was tested in its virgin and used form, for genotoxicity and embryotoxicity. The latter appeared to be more effective than the virgin eutectic. This increase in the embryo- and genotoxicity of the used eutectic may be related to the appearance of newly formed compounds in the heat transfer process. These compounds have been separated by high-pressure liquid chromatography and detected by fluorimetry.

Animals↗