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Biomedical subjects

A Barbieri

Publications and source records attributed to A Barbieri.

At least 91 records · Page 5Linked to original sources
PubMed1992

Lung and myocardial thallium-201 kinetics in resting patients with congestive heart failure: correlation with pulmonary capillary wedge pressure.

Increased lung thallium-201 activity occurs with exercise in patients with severe coronary artery disease as a result of increased pulmonary capillary wedge pressure. No study has shown resting lung kinetics in chronic congestive heart failure. To better understand the relationship between lung and myocardial thallium uptake and pulmonary capillary wedge pressure, this study was performed. Resting lung and myocardial thallium uptake, expressed as a ratio, were compared with simultaneous pulmonary capillary wedge pressure in 16 patients with congestive heart failure and cardiomyopathy, all New York Heart Association class IV. There were no variations in pulmonary capillary wedge pressure throughout the study protocol. There was a significant reduction in the lung/myocardium thallium ratio from 10 to 60 minutes (0.83 +/- 0.30 to 0.59 +/- 0.17; p less than 0.001). At 60 minutes after thallium injection there was a linear correlation between the lung/myocardium ratio and capillary wedge pressure with an r value of 0.62 (p less than 0.01). Thus thallium-201 washout is rapid despite persistence of pulmonary capillary wedge pressure elevation, indicating that clearance does not imply resolution of congestive heart failure. In addition, a significant but imprecise correlation was found between capillary pressure and the lung/myocardium ratio. Rapid changes in lung activity during the early postinjection period may limit the clinical use of the lung/myocardium ratio.

Catheterization, Swan-Ganz↗
PubMed1992

Effects of cromakalim (BRL 34915) on resting and evoked activity in frog semicircular canals.

The effects of endolymphatic administration of cromakalim and glibenclamide were tested in isolated semicircular canals of the frog. The actions of the drugs were evaluated by recording: (1) the transepithelial potential between the endolymphatic and the perilymphatic sides of the crista ampullaris; (2) the slow nerve potential from the ampullar nerve; (3) the action potential discharge in afferent ampullar nerve fibres; and (4) the perilympathatic potassium concentration in the fluid bathing the outer surface of the crista ampullaris. The above mentioned parameters were recorded both at rest and during mechanical stimulation of the sensory organ. The results demonstrated that the endolymphatic administration of cromakalim (10(-4) M) produced an increase in both ampullar receptor resting activity and in perilymphatic K+ resting levels. By contrast all the parameters related to the mechanically evoked responses were practically unaffected. Glibenclamide (10(-4) M) proved able to cancel or to prevent cromakalim effects. These data suggest that the membrane of the hair cells is endowed with K+ channels regulated by internal ATP whose activation is mainly involved in the processes sustaining ampullar receptors' resting firing rate.

Adenosine Triphosphate↗
PubMed1992

[Death in the context of obstetric nursing: perspectives of care].

The authors intend to unveil facets of the meaning of mother's care who has lost her baby at the end of pregnancy, in the nursery labor view. For that, they used a Qualitative Research Methodology. The phenomenological methodology of inquiry allowed them to reach the subject of the study. The data were collected from obstetric office employees that answered a guiding question. The analysis of these answers reveals important points linked to this mother's care.

Death↗
PubMed1991

Inhibition by glibenclamide of the effects of cromakalim on responses of rat vas deferens to naphazoline.

Cromakalim has been shown to inhibit naphazoline-induced contractions and spontaneous activity induced by exposure to naphazoline in the rat isolated vas deferens. Glibenclamide 10(-6) M blocked both these effects of cromakalim. Our data add to the list of data derived mainly from experiments on vascular smooth muscle; they suggest that the same glibenclamide-sensitive K+ channel is present in vascular and non-vascular smooth muscle and that it may be involved in the relaxant actions of cromakalim.

Animals↗
PubMed1991

Human complement factor H. Tissue specificity in the expression of three different mRNA species.

Using cDNA clones H-19 and H-46, we have shown previously that three different mRNA species (4.3 kb, 1.8 kb and 1.4 kb) for complement factor H are expressed constitutively in human liver. Here we report data suggesting that the expression of these different factor-H mRNA species is regulated by tissue-specific control mechanisms. Total RNA and poly(A)-enriched RNA from various human tissues (heart, lung, temporal cortex, kidney, spleen, bone marrow and muscle) various cell lines (HepG2, HepG3, HepG4, Hep3B, H-4, Jurkat, Molt4, H-9, KHos24Os, A-431, U937, Mono Mac 6 and Raji) and from primary cultures of peripheral blood monocytes, fibroblasts and human umbilical vein endothelial cells (HUVEC) were investigated for the expression of factor-H mRNA. In RNA preparations from extrahepatic tissue, factor-H mRNA was only detected in biopsies from the lung. Using 20 micrograms total RNA isolated from all 13 cell lines it was not possible to detect any factor-H mRNA, while mRNA for factor H was expressed in monocytes, HUVEC and fibroblasts. When expressed in extrahepatic tissues, only the 4.3-kb and the 1.8-kb mRNA species were detected, while the 1.4-kb mRNA is expressed abundantly in liver. Interferon-gamma did not induce the expression of factor-H mRNA in any of the cell lines tested. On the other hand, tumour necrosis factor-alpha induced the expression of the 4.3-kb mRNA species in U937 cells. In HUVEC and fibroblasts the relative quantities of the 4.3-kb and the 1.8-kb mRNA species and the regulatory effects of interferon-gamma, interleukin-1, dexamethasone and retinoic acid on their expression showed significant tissue specificity.

Blotting, Northern↗
PubMed1991

Zinc and copper in breast cancer. A joint study in northern Italy and southern France.

The relationship between breast cancer and two trace elements, zinc (Zn) and copper (Cu), was investigated by means of an hospital based case-control study at Milan (Italy) and Montpellier (France). Variables concerning dietary intake of Zn and Cu (in Milan) and their blood levels (both in Milan and Montpellier) were measured. Dietary intake, evaluated through a questionnaire of the dietary history type, and blood levels of Zn and Cu were measured in 261 cases and 261 controls. Cu blood level showed a contradictory tendency in the two samples (higher in controls in Milan, higher in cases in Montpellier), which tended to lessen after adjustment for related variables. No odds ratios (OR) in the different quantiles, nor X2 for trend reached statistical significance. A sharp difference was evidenced on the opposite with regard to Zn blood values in cases and controls. In both samples Zn mean values are significantly higher in cases than in controls, and the difference remains significant in the two samples even after adjustment for related variables. The pooled OR computed from the two samples, after adjustment for known risk factors and related variables, reaches in the fourth quartile a value of 9.5 (CI: 4.9-18.2). Dietary intake of the two minerals (measured only in Milan sample) showed no difference between cases and controls, but a stronger relationship between dietary and blood Zn was evidenced in cases with respect to controls. The authors suggest that the higher Zn level in cases might be related with an higher incorporation of Zn in cancer cases and that the same mineral might play a possible role in tumor growth promotion.

Adult↗
PubMed1991

Effects of cromakalim (BRL 34915) on mechanical responses of rat vas deferens to noradrenaline and naphazoline.

The contractile responses produced by noradrenaline were compared to those produced by naphazoline in the rat isolated vas deferens, a preparation which is usually quiescent. The responses to noradrenaline were biphasic: prominent spontaneous contractile activity was superimposed on contractions produced by naphazoline. After removal of naphazoline the rat vas deferens displayed periodic spontaneous activity. The effects of cromakalim and verapamil were compared on contractions induced by noradrenaline and naphazoline and on spontaneous activity induced by exposure to naphazoline. Cromakalim (1-10 x 10(-7) M) shifted to the right the cumulative concentration-response curve of naphazoline but not that of noradrenaline; at the same range of concentrations, cromakalim inhibited naphazoline-induced periodic spontaneous activity. Verapamil (3-30 x 10(-8) M) flattened in a dose-dependent manner the concentration-response curves of noradrenaline and naphazoline; higher concentrations of verapamil (3-30 x 10(-6) M) were required to modify periodic spontaneous activity. It was concluded that naphazoline but not noradrenaline can block K+ channel(s) and that this property can represent an important difference between imidazolines and phenethylamines.

Animals↗
PubMed1991

Potentiating actions of tranylcypromine and moclobemide on the sympathomimetic activity of dopamine.

Ex vivo investigations were carried out to study the potentiating actions of the MAOIs moclobemide and tranylcypromine on peripheral alpha- and beta-adrenergic effects of dopamine. Isolated rat vas deferens and atria were used. Preliminary experiments showed that both moclobemide and tranylcypromine did not affect the response to noradrenaline, while they enhanced the response to tyramine. By comparison of the responses to dopamine in control and reserpinized rats, it was shown that dopamine acts in a direct and indirect manner on both the tissues tested. Two concentrations (20, 40 mg/kg, i.p.) of moclobemide were tested and administered at different time periods (2, 5 or 24 h) before the animals were sacrificed. Two concentrations (2, 20 mg/kg, i.p.) of tranylcypromine were tested at different intervals of time (2, 24 h). The results obtained pointed out that: (1) Moclobemide 20 mg/kg potentiated the alpha-adrenergic response to dopamine only 2 h after administration while 40 mg/kg exerted a potentiation which was evident not only 2 but also 5 h after administration. Both doses were ineffective 24 h after administration. (2) Moclobemide 20 and 40 mg/kg potentiated the beta-adrenergic response to dopamine. The effect was present 2 and 5 h after administration but it was absent 24 h after. (3) Tranylcypromine 20 mg/kg potentiated the alpha-adrenergic response to dopamine: this effect was present after 2 h from pretreatment and was still evident after 24 h. The lower concentration of tranylcypromine (2 mg/kg) enhanced the response to dopamine only after 24 h from pretreatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Human complement factor H: molecular cloning and cDNA expression reveals variability in the factor H-related mRNA species of 1.4 kb.

Previously, we have shown that three different mRNA species of 4.3 kb, 1.8 kb and 1.4 kb, related to human complement factor H, are constitutively expressed in the human liver. Probing with our cDNA clone H-46 which represents 920 bp of the 3' end of the 4.3 kb mRNA of factor H on human liver RNA, we always detected the 4.3 kb and the additional, abundantly expressed mRNA species of 1.4 kb in length, indicating that the 1.4 kb transcript is highly homologous to the 3' end of the classical factor H mRNA of 4.3 kb. Using H-46 as a probe, several cDNA clones were isolated from a liver cDNA library and sequenced. The open reading frame of the novel mRNA species encodes a peptide consisting of five internal short consensus repeat motifs (SCR), identifying the translational product to be a member of the SCR family. Sequence comparison with cDNA clones derived from liver RNA of a different donor provided evidence for variability in the factor H related proteins encoded by the 1.4 kb mRNA species. Interestingly, this variability was found to be restricted to the three carboxyterminal SCR domains. Expression data indicate that our variant is not recognized by the monoclonal antibody 3D11.

Amino Acid Sequence↗
PubMed1991

Brain and spinal cord metabolic activity during propofol anaesthesia.

We have investigated the effects of propofol anaesthesia on the metabolic activity pattern of 35 regions of the rat brain and cervical spinal cord using the 14C-2-deoxyglucose technique. Anaesthesia was produced by an i.v. bolus of the commercial preparation of the drug (8 mg kg-1) and maintained with successive bolus administrations of 6 mg kg-1. Functional activity values (expressed as rates of local utilization of glucose) were reduced in 31 grey matter and two white matter structures in a propofol group relative both to saline-injected and vehicle-injected (aqueous emulsion containing 10% soya bean oil, 1.2% egg phosphatide and 2.25% glycerol) controls. Values from the two control groups did not differ significantly. Propofol-induced depression of metabolic activity was present in central nervous system regions belonging to sensory (auditory, visual and somatosensory), motor and limbic systems, including spinal cord grey matter. Mean percentage decreases ranged from 40% (vestibular nuclei) to 76% (cingulate cortex). Although these values may be slightly overestimated because of the modest increase in PaCo2 in the anaesthetized group, propofol appeared to elicit generalized reduction of central nervous system functional activity.

Anesthesia, Intravenous↗
PubMed1991

Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy.

In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, we investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. We observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of our patients with positive DTTs had unimpaired coronary circulations, we conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program.

Adolescent↗
PubMed1991

[Pleural empyema and ruptured subdiaphragmatic abscess].

The authors report a case of a ruptured right subphrenic abscess causing a diffuse peritonitis complicating a chronic empyema. The authors recommend active treatment of purulent pleurisies, particularly when they are associated with a bronchopleural fistula.

Bronchial Fistula↗
PubMed1990

[The meaning of perinatal death--the statements of mothers].

The author's propose is to reveal the meaning of the perinatal death seen by mothers. For that, they used a qualitative methodology which makes possible a comprehensive analysis of mother's statements who are passing by this situation in the hospitals. The convergences of these speeches are analysed and they make possible the identification in some significative units that may establish and aid to guide the assistencial plan for mothers in order to observe their situation.

Adaptation, Psychological↗
PubMed1989

Psychological aspects of testis cancer therapy: a prospective study.

We examined the impact of testis cancer and its curative therapies on the outlook of life, working activity, partner relationship and sexual function in 31 consecutive patients 18 to 51 years old (mean age 29.3 years, median 28 years) who already had undergone orchiectomy. Of the patients 13 subsequently were treated with chemotherapy alone, 6 with retroperitoneal lymph node dissection alone, and 7 with chemotherapy and an operation, while 5 seminoma patients were treated with radiotherapy. The patients were examined 3, 6 and 18 months after orchiectomy. Each patient was required to fill out a questionnaire to gather information relative to their work activities, emotional relationship with the partner and sexual life. The patients also completed an assessment form on the quality of life (Spitzer QL-Index) and a series of horizontal analogues to evaluate anxiety, mood, nausea, weakness and general health status. The statistical analysis of the linear and quadratic components for the variables under study was done with the general linear model for block design. Psychosocial adaptability of these patients, regardless of the treatment they underwent, in time became progressively less problematic and the development of psychosocial problems during the long-term adjustment was low. Only 2 patients reported worsening of the emotional relationship with the partner after treatment: 1 underwent chemotherapy and an operation, and 1 underwent radiotherapy. With regard to sexual life, no serious dysfunction was noted apart from the loss of ejaculation in 11 of 13 patients who underwent retroperitoneal lymph node dissection. Of our sample patients who had lost ejaculation only 2 suffered from a high state of anxiety. The anxiety scores on the last completed linear analogue were 2.6 and 4.1, whereas at the same time the mood scores were 1.9 and 4.4. Therefore, it is important for the clinician to assess the psychogenic aspect of this side effect when this type of operation is proposed.

Adaptation, Psychological↗