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Biomedical subjects

G Russo

Publications and source records attributed to G Russo.

At least 253 records · Page 14Linked to original sources
PubMed1989

Evidence for a further stimulation of atrial natriuretic factor release by atrial pacing in patients with mitral stenosis.

To investigate the release of atrial natriuretic factor (ANF) in mitral stenosis and the effect of an increased atrial contraction frequency on atrial distension and ANF secretion, we studied 14 patients [New York Heart Association (NYHA) grades II-III] in sinus rhythm, undergoing cardiac catheterization for mitral stenosis. Echocardiographic tracings, repeat determinations of mean pulmonary artery wedge pressure and blood samples from the pulmonary artery for ANF measurements were taken at baseline, during atrial pacing (125 beats/min for 5 min) and 5 min after pacing. After pacing, ANF levels rose markedly with a parallel increase in mean pulmonary artery wedge pressure and left atrial size. These data indicate that atrial pacing is capable of further stimulating ANF release, even in patients with elevated baseline ANF and left atrial pressure and an increased left atrial dimension.

Adult↗
PubMed1989

Differential expression of human HOX-2 genes along the anterior-posterior axis in embryonic central nervous system.

We have investigated the structure of the human HOX-2 locus, which encompasses a 90-kb region on chromosome 17q21. Five new human HOX-2 homeoboxes, termed HOX-2.5, 2.4, 2.6, 2.7 and 2.8, have been identified, and their nucleotide sequences are reported. They have the same 5'-3' transcriptional orientation and are clustered with three previously described HOX-2 homeoboxes (5'-2.5-2.4-2.3-2.2-2.1-2.6-2.7-2.8-3'). We have also investigated the region-specific expression of HOX-2 genes in human embryonic-fetal life by Northern-blot analysis. All genes are expressed in whole embryos and fetuses at 5-9 weeks from conception. Their major site of expression lies within the central nervous system (CNS), although they are transcribed at a lower level in body structures other than the CNS. Their relatively abundant expression in CNS has been analyzed along the anterior-posterior axis by dissecting the brain, the medulla oblongata and the spinal cord proper. HOX-2.5, 2.4 and 2.3 transcripts are markedly more abundant in spinal cord than in medulla, whereas 2.2, 2.1, 2.6 and 2.7 mRNAs are progressively more abundant in the medulla. Additionally, expression in brain was detected, although at lower level, for HOX-2.1, 2.6, 2.7, 2.8. Thus, the relative position of HOX-2 homeobox genes along the chromosome in the 5'-3' direction appears to correlate with the relative position of their expression domains along the CNS longitudinal axis in the caudal-cephalic direction.

Amino Acid Sequence↗
PubMed1989

Expression of protein kinase C genes during ontogenic development of the central nervous system.

We have analyzed the RNA expression of three protein kinase C (PKC) genes (alpha, beta, and gamma) in human and murine central nervous systems during embryonic-fetal, perinatal, and adult life. Analysis of human brain poly(A)+ RNA indicates that expression of PKC alpha and beta genes can be detected as early as 6 weeks postconception, undergoes a gradual increase until 9 weeks postconception, and reaches its highest level in the adult stage, and that the PKC gamma gene, although not expressed during embryonic and early fetal development, is abundantly expressed in the adult period. Similar developmental patterns were observed in human spinal cord and medulla oblongata. A detailed analysis of PKC gene expression during mammalian ontogeny was performed on poly(A)+ RNA from the brain cells of murine embryos at different stages of development and the brain cells of neonatal and adult mice. The ontogenetic patterns were similar to those observed for human brain. Furthermore, we observed that the expression of PKC gamma is induced in the peri- and postnatal phases. These results suggest that expression of PKC alpha, beta, and gamma genes possibly mediates the development of central neuronal functions, and expression of PKC gamma in particular may be involved in the development of peri- and postnatal functions.

Animals↗
PubMed1989

High frequency of cancer in cold thyroid nodules occurring at young age.

In order to evaluate the risk of malignancy of cold thyroid nodules occurring in young as compared with adult patients, we studied a consecutive series of 2327 patients with a solitary cold thyroid nodule over a 6-year period. None of these patients had been previously irradiated in the neck or head. Fine needle aspiration of the nodule and cytologic examination were carried out in all patients and, on the basis of this evaluation and clinical examination 391 patients were selected for surgery; 109 patients were 4-20 years old and 2218 patients were older than 20 years. Malignancy was found in 11 (10.1%) and in 112 (5.0%) of cold thyroid nodules occurring in young and adult patients, respectively. The annual incidence of cold thyroid nodules in the population of the area studied was 5.2 vs 55.9 (per 10(5) inhabitants) in the young and in the adult group, respectively, and the annual incidence of thyroid cancer was 0.53 vs 2.82 (per 10(5) inhabitants) in the young and in the adult patients, respectively. The present study indicates, therefore, that in the absence of head or neck irradiation, cold thyroid nodules are much less frequent in young age, but that the malignancy rate of cold nodules occurring in young patients is 2-fold higher than in adults patients.

Adolescent↗
PubMed1989

Influence of phenomenal time on perceived space.

It is known from work by Helson and King that the apparent spatial distance between stimuli presented in succession depends on the time interval between those stimuli ("tau effect"). It is also known that the apparent time (i.e., the interval of time perceived between stimuli presented in succession) depends on the spatial distance between the stimuli defining the time interval (called "kappa effect" by Cohen, Hansel, and Sylvester). For the "kappa effect," apparent time between lights and stimuli on the skin of the forearm undergoes modification depending on the apparent spatial distance, as presented in Suto's work beginning in the early 1940s. The present work is complementary to Suto's. Its purpose is to test whether apparent spatial distance depends on the objective or subjective (apparent, phenomenal) time interval. To achieve this, our crucial (third) experiment was preceded by two exploratory experiments: the first to verify the illusion in which a subdivided interval appears longer than an empty interval of the same length (Oppel-Kundt temporal illusion); the second to verify the presence of the "tau effect" with simultaneous tactual and auditory stimuli for time intervals between 1500 and 2500 msec. In the third experiment subjects received successive tactual stimuli defining two spatial distance and two time intervals. They also received auditory stimuli that produced the Oppel-Kundt illusion by making the time intervals phenomenally different. The results fill a small experimental gap by showing it is subjective (phenomenal) and not objective (physical) time that influences perceived spatial distances.

Adolescent↗
PubMed1989

[Usefulness and limitations of hormonal monitoring of pregnancy with HPL and estriol in improving fetal prognosis and preventing neonatal neurologic deficiency].

This multidisciplinary research has been subdivided into two parts. The first examines prognosis of the foetus and its weight development in relation to changes in the hormonal curves of HPL and E3 carried out in a batch of 339 3rd term pregnancies. A very high incidence of small-for-date newborns (30-64%) was noted in mothers with low hormonal values and generally a more frequent onset of hypoxia in pregnancy and in labour. The second part assesses the neurological profile of children born to the same mothers examined in the first part up to the 4th year of life. A neurological deficiency of a different extent was evidenced in 33.3% of the children born to mothers with low hormonal values in pregnancy, especially among those born underweight. The neurological deficiency in the control sample was 7.84%.

Adolescent↗
PubMed1989

[Properties of the postsynaptic depolarization produced by glutamate on the vestibular receptors in frogs].

In order to investigate the possible role of glutamate (Glu) as afferent transmitter in the vestibular system, this agent was tested on sensory organs of frog semicircular canals. Intracellular recordings from single afferent axons in isolated labyrinths showed that, after blocking chemical transmission with high Mg++ (12 mM), micro-injections of Glu (5 mM-15 ul) elicited a long lasting postsynaptic depolarization. The amplitude of this depolarization was reduced dose dependently after addition of the amino acid antagonists Kynurenic acid or gamma-D-glutamylglycine to the bath. When the Na+ concentration in the bath was progressively reduced, the depolarization decreased gradually and disappeared almost completely in Na(+)-free Ringer. The removal of K+ affected the depolarization to a lesser extent: in K(+)-free Ringer depolarization decreased only by 30-40%. On the contrary, the complete substitution of Ca++ ions in the bath was without effect. Our results suggest that in the frog semicircular canals the postsynaptic depolarization induced by Glu involves the activation of non NMDA type of amino acid receptors, probably coupled to channels selective for Na+ and K+ ions. The present findings are consistent with the hypothesis that Glu or a related substance may be the transmitter released at the afferent synapses of the vestibular receptors.

Animals↗
PubMed1989

[Acute latent myocarditis appearing with ventricular fibrillation after intranasal administration of adrenaline. Description of a case].

We report a case of a 17 year old sports woman, who had a ventricular fibrillation episode with cardiogenic shock during endonasal anaesthesia containing epinephrine. She was so transferred to our department (in shock): the 2-D echo showed biventricular hypokinesia without dilatation (LVEF less than 25%). Endomyocardial biopsy performed 5 days later showed active lymphocyte myocarditis with interstitial fibrosis. There were serum antibodies anti-Echo 9 and Coxsackie B 1, 2, 3. Immunoassay, urinary catecholamines and glucagon test were normal. The clinical picture was resolved within 15 days using intravenous isoprenaline and/or dopamine initially followed by oral diuretics and digoxin; the therapy was broke off at the time of discharge. We believe that the vasoconstriction and/or the oxygen wasting effect caused by epinephrine revealed latent myocarditis which had not been shown up even by intensive physical training.

Adolescent↗
PubMed1989

Erythropoietin alone induces erythroid burst formation by human embryonic but not adult BFU-E in unicellular serum-free culture.

Erythroid progenitors (BFU-E) from adult human peripheral blood generate erythroid bursts in semisolid culture supplemented with at least two growth factors, ie, erythropoietin (Ep) and interleukin-3 (IL-3) or granulocyte-macrophage colony-stimulating factor (GM-CSF). We have analyzed the hematopoietin(s) requirement of human embryonic BFU-E, as compared to that of adult peripheral blood progenitors: This was basically evaluated in fetal calf serum-free (FCS-) methylcellulose culture of partially or highly purified progenitors treated with human recombinant hemopoietins. At a low seeding concentration (2 x 10(3) cells/dish) purified embryonic BFU-E generated erythroid bursts when treated only with Ep: Further addition of IL-3 or GM-CSF had no effect on BFU-E cloning efficiency, although the size of bursts was increased in a dose-dependent manner, particularly with IL-3. At a similar seeding concentration (ie, 10(3) cells/dish), purified adult BFU-E efficiently generated erythroid bursts in the presence of Ep and GM-CSF or IL-3, while only few small erythroid colonies were observed in the presence of Ep alone. In a final series of experiments, unicellular FCS-cultures of purified embryonic BFU-E gave rise to erythroid bursts in the presence of Ep alone. Furthermore, the cloning efficiency induced by Ep was unmodified by further addition of GM-CSF or IL-3. Unicellular FCS- cultures of highly purified adult peripheral blood progenitors generated no erythroid bursts in the presence of Ep alone. The addition of GM-CSF or IL-3 was required to generate BFU-E colonies. These studies indicate that in human embryonic life, BFU-E require only Ep for efficient erythroid burst formation, while IL-3 and GM-CSF essentially enhance the proliferation of early erythropoietic precursors.

Cells, Cultured↗
PubMed1989

[Tumor markers in the early diagnosis of thyroid neoplasms].

Radioimmunological techniques were used to assay tumour markers in order to identify neoplasms in patients with thyroid nodules at the earliest possible stage. In the 7 patients with differentiated thyroid tumours, the marker findings were within normal limits. On the basis of these results it is concluded that at the present time these markers are of no value for the early diagnosis of thyroid tumours.

Adolescent↗
PubMed1989

Microbiological characterization of dactimicin: antibacterial activity towards gram-positive and gram-negative bacteria.

Dactimicin is the first aminoglycoside antibiotic of Dactylosporangium origin, consisting of a pseudo-disaccharide and an amino acid. It has also a formimidoyl moiety instead of the deoxystreptamine found in other aminoglycosides. The authors considered the antibacterial activity of dactimicin compared with amikacin, gentamicin and the fortimicins against Gram-positive and Gram-negative bacteria. Dactimicin showed remarkable antibacterial activity against all strains tested: in particular the MIC90 values ranged from 2 mg/l for Citrobacter sp. to 32 mg/l for Proteus sp. Methicillin-resistant staphylococci were poorly susceptible to all aminoglycosides tested, while dactimicin showed good activity against the methicillin-susceptible strains. MBCs and killing curves indicated that this drug is rapidly bactericidal against all strains tested.

Aminoglycosides↗
PubMed1989

Failure to correlate ampicillin and amoxicillin resistance by standard disk susceptibility tests and minimal inhibitory concentration in Haemophilus species.

22 Haemophilus strains, isolated from lower respiratory tract infections, were tested for their susceptibility to ampicillin and amoxicillin using both MIC and Kirby Bauer methods. Ampicillin and amoxicillin resistance tested with MIC method was not exactly correlated with Kirby Bauer standard (10 mcg ampicillin and 25 mcg amoxicillin disks) inhibition zones method (error rate: 52.6%). Yet using a 2 mcg ampicillin and 5 mcg amoxicillin handmade disk, error range decreased to 14.8%. Beta-lactamase production on whole cells were for 6 strains of the 22 tested. After breaking the cell wall, 19 on the 22 strains were beta-lactamase producers, confirming the results obtained with the MIC method.

Amoxicillin↗