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Biomedical subjects

G Russo

Publications and source records attributed to G Russo.

At least 217 records · Page 12Linked to original sources
PubMed1991

Evaluation of the fine needle aspiration biopsy in the preoperative selection of cold thyroid nodules.

From 1980 to 1988 the authors examined by fine needle aspiration biopsy (FNAB) 4609 patients with solitary thyroid nodules or multinodular goiters. A total of 5605 "cold" thyroid nodules were evaluated and classified, on the basis of the cytologic findings, as malignant, follicular lesions (probably malignant and probably benign) and benign. Then the authors compared the preoperative cytologic findings with the postoperative histologic results in 827 nodules from patients who underwent surgery. In the 805 thyroid nodules in which an adequate cytologic specimen was obtained, false-negative results were 2.3% and false-positive findings were 1.1% By comparing cytologic and histologic diagnoses, preoperative FNAB resulted in the ability to accurately assess the risk of cancer in a thyroid nodule; since 250 nodules were identified as malignant, the risk of a "cold" thyroid nodule being cancer was 4.46% in this series.

Adenoma↗
PubMed1991

Pulmonary edema during cardiac catheterization successfully treated with bolus administration of nicardipine.

This report describes a 62-year-old patient with ischemic dilated cardiomyopathy who presented pulmonary edema during cardiac catheterization. Bolus administration of nicardipine (5 mg in 5 min) into the pulmonary artery determined prompt recovery from the crisis and optimal hemodynamic conditions for completion of the catheterization. The action of the drug was mediated by the rapid reduction of the left ventricular preload and afterload. We believe that bolus administration of nicardipine is useful in treating episodes of acute left ventricular insufficiency.

Cardiac Catheterization↗
PubMed1991

Isolated, anomalous origin of the left anterior descending coronary artery from the right coronary artery with angina pectoris.

The case of a 51-year-old woman with exertional angina pectoris and isolated anomalous origin of the left anterior descending coronary artery from the right coronary artery is reported. This anomalous artery was not narrowed, coursed in front of the pulmonary artery and did not present either anatomical derangement at the take off or intramyocardial course. The mechanism of ischaemia could not be identified.

Angina Pectoris↗
PubMed1991

Direct and indirect pathogenicity of beta-lactamase-producing bacteria in respiratory tract infection in children. Role of cephalosporins resistant to enzymatic hydrolysis.

A recent increase in the incidence of beta-lactamase-producing aerobic and anaerobic bacteria in upper respiratory tract infection has been associated with an increase in the failure rate of penicillin treatment of these infections. Experimental evidence for this correlation has been reported by many investigators, who have described the sheltering of susceptible pathogens by beta-lactamase-producing organisms as 'indirect pathogenicity'. The organisms implicated in mixed infections that cooperate are Staphylococcus aureus, Haemophilus influenzae, Branhamella (Moraxella) catarrhalis and Bacteroides spp., which are pathogenic and also normal oropharyngeal inhabitants. Since these bacteria exhibit both direct and indirect pathogenicity, effective treatment requires administration of antimicrobial therapy active against all microorganisms present in mixed infection. Oral third generation cephalosporins, which are resistant to enzymatic hydrolysis, seem to be suitable initial therapy.

Bacteria↗
PubMed1991

Significance of Haemophilus spp. and Branhamella catarrhalis in upper respiratory tract infections.

Haemophilus influenzae and Branhamella catarrhalis can be considered inhabitants of the upper respiratory tract in humans. Although the pathogenetic role of H. influenzae cannot be discussed, the Authors report the mechanisms of pathogenicity of this microorganism; furthermore, they discuss the direct or indirect pathogenicity of B. catarrhalis in respiratory tract diseases and the ability of both microorganisms to produce beta-lactamases. H. influenzae and B. catarrhalis, together with S. pneumoniae, are the most common bacteria responsible for upper respiratory tract infections, namely otitis and sinusitis. The activity of these bacteria in the onset of otitis and sinusitis is reported.

Haemophilus Infections↗
PubMed1991

Biologically active recombinant prothrombin and antithrombin III expressed in a human hepatoma/vaccinia virus system.

Several systems have been devised that are based on viral promoters suitable for gene expression in eukaryotic cells. One such system, vaccinia virus, has been successfully used to express a variety of heterologous proteins following the construction of a recombinant virus. Indeed, because of the ability of vaccinia virus to infect a wide range of host cells, the expression system can be custom-designed so that a cell line can be instrumental in ensuring the correct processing of the recombinant polypeptide. We show that recombinant vaccinia virus and human hepatoma cells in culture are an efficient expression system with which to produce correctly modified and biologically active human prothrombin (15 micrograms/10(7) cells) and antithrombin III (40 micrograms/10(7) cells).

Animals↗
PubMed1991

[K+ and Ca++ currents in hair cells isolated from the semicircular canals of the frog].

Hair cells of the inner ear are endowed with different types of ionic channels. To characterize voltage- and ion-dependent channels in vestibular hair cells, experiments were performed in enzymatically isolated hair cells of frog semicircular canals by using the whole-cell configuration of the patch-clamp technique. A large outward current, identified as a K+ current, was recorded when 132 mM KCl were present in the pipette filling solution. It could be dissected pharmacologically into three different components. The first component, which was transient and selectively blocked by 10 mM external 4AP, is most likely an IA-type current. The second one, sensitive to 20 mM external TEA, might be a delayed rectifier K+ current, while the third component insensitive to TEA and showing faster activation time course has been interpreted as a K+ current of IKCa-type. After blocking the outward current by substituting Cs+ for K+ and adding 20 mM TEA to the internal solution, a sustained inward current, identified as a Ca++ current, could be recorded. This current did not inactivate, and was blocked by Cd++ more effectively than Ni++, thus suggesting the presence of Ca++ channels similar to the neuronal "L" channels. Since both K+ and Ca++ channels were recruited at potentials near the resting level, it is suggested that they are involved in the modulation of the resting as well as the evoked transmitter release from the basal pole of the hair cells.

4-Aminopyridine↗
PubMed1991

[Bolus nicardipine in the hemodynamic assessment for heart transplantation of patients with severe failure of ischemic origin and high pulmonary resistance].

Nicardipine i.v. bolus (5 mg/5 min) was administered in the pulmonary artery trunk in 13 patients (2 f, 11 m), mean age 48 +/- 8 yrs, affected by ischemia congestive heart failure, with pulmonary hypertension (pulmonary vascular resistances greater than 6 U.W. and/or systolic pulmonary artery blood pressure greater than or equal to 60 mmHg). The vasodilatation induced by nicardipine caused a rapid improvement of all hemodynamic parameters, with a significant reduction of systemic and pulmonary pressures and resistances; in addition, cardiac output increased significantly. Even if heart rate decreased and mean right atrial pressure fell, their variation did not reach statistical significance. These beneficial effects are attributable to the vasodilator action of nicardipine on the systemic and pulmonary vascular districts. Therefore, in the hemodynamic evaluation of patients with ischemic cardiomyopathy proposed for heart transplantation, we propose the employment of nicardipine in testing the vascular reactivity in cases with secondary pulmonary hypertension.

Adult↗
PubMed1991

[Early myocardial involvement in collagen diseases. An endomyocardial biopsy study].

Endomyocardial biopsy was performed in three patients affected by systemic connectivitis (one case of systemic lupus erythematosus--SLE--, one of scleroderma and one of dermatomyositis). The analysis of the specimens revealed the presence of fibrosis and microvascular lesions (these latter only in SLE). Immunofluorescence showed in SLE and scleroderma perivascular IgG or perisarcolemmal IgM deposits respectively. Despite the scarcity of cardiac signs and symptoms, cardiac involvement can be early and frequent in connectivitis. The immune pathogenesis of the cardiac lesions seems to be possible because of the presence of immunocomplexes in the myocardium.

Adolescent↗
PubMed1990

Rearrangements in the human T-cell-receptor alpha-chain locus in patients with adult T-cell leukemia carrying translocations involving chromosome 14q11.

We describe 5 cases of adult T-cell leukemia (ATL) carrying translocations at chromosome 14q11, where the genes for alpha- and delta-chains of the T-cell receptor (TCR alpha/delta) reside (Croce et al., 1985; Isobe et al., 1988). Since the TCR alpha/delta locus is the region where several types of chromosome translocations occur in T-cell tumors, rearrangements of the TCR alpha/delta locus in those ATL cases were studied as a first step to characterize these translocations at the molecular level. For this purpose we have generated an extensive series of probes to define the specificity and the diversity of rearrangement occurring at the widely spanned J alpha-C alpha locus and the complex D delta-J delta-C delta-V delta 2 locus. Using a set of probes, we have found the deletion of the TCR delta locus in all ATL cases, and at least 2 rearrangements in the J delta locus in each case of ATL. It is possible that translocations in the TCR alpha locus may be involved in ATL.

Chromosome Mapping↗
PubMed1990

Blood coagulation factors in human embryonic-fetal development: preferential expression of the FVII/tissue factor pathway.

The expression of a number of blood coagulation factors (F) (FX, FIX, FVIII, FVII, alpha-, beta-, gamma-fibrinogen chains, protein C, and antithrombin III [AT III]) was analyzed at RNA and protein level in 5- to 10-week-old human embryos and fetuses. FX, FIX, and FVII were also analyzed at protein level. Total and poly(A)+ RNA, extracted from embryonic-fetal (FL) and adult liver (AL), were analyzed by dot and Northern blot hybridization with specific cDNA probes. The results indicate that: (1) the size of the messenger RNAs of these factors is equivalent in FL and AL; (2) in the 5- to 10-week period, their abundance in FL increases from 30% to 50% of the adult level except for FIX (from 2% to 10%) and FX (always 100% of the adult value). Western blot analysis of FIX, FX, and FVII in 5- to 10-week soluble liver proteins and 6- to 8-week plasma showed a low level of FIX versus a higher concentration of both FVII and FX, when compared with corresponding adult values, ie, a liver protein level of 10% versus 100% and a plasma concentration level of 10% versus 40%. Although little is known so far on the activity and the functional role of the clotting factors in early human ontogenic development, these studies suggest an activation of FX via the FVII/tissue factor activity rather than the FIXa/FVIIIa phospholipid complex in human embryonic and early fetal life.

Blood Coagulation Factors↗
PubMed1990

Molecular mechanisms underlying the expression of the human HOX-5.1 gene.

The complex mechanisms underlying homeobox genes expression involve regulation at transcriptional, post-transcriptional and translational levels. The multiple transcripts of the human HOX-5.1 gene are expressed differentially in tissue- and stage-specific patterns during embryogenesis, and differentially induced by retinoic acid (RA) in human embryonal carcinoma (EC) NT2/D1 cells. We have sequenced 6.3 Kb of the genomic region containing the HOX-5.1 gene and analyzed its mechanisms of expression. Two alternative promoters underlie the transcription of two classes of HOX-5.1-specific mRNAs. These classes differ in tissue and subcellular distribution, induction by RA, structure of the 5'-UT region and mRNA stability: these features are compatible with a differential function of the two classes of transcripts in embryogenesis.

Amino Acid Sequence↗
PubMed1990

HLA expression in hemopoietic development. Class I and II antigens are induced in the definitive erythroid lineage and differentially modulated by fetal liver cytokines.

We investigated the expression of HLA Ag on hemopoietic progenitors (burst-forming unit E, CFU-E, and CFU-granulocyte-macrophage) and precursors from human embryonic fetal liver (FL) and peripheral blood at 5 to 9 wk postconception. The expression on progenitors was evaluated by complement-mediated cytotoxicity followed by assay of residual progenitors in clonogenic culture; immunofluorescence and RIA were used for differentiated precursors. HLA Class I and II Ag are not expressed on the primitive erythroid lineage, i.e., on yolk sac-derived megaloblasts circulating in 5- to 6-wk peripheral blood. However, they are gradually induced on the definitive erythroid lineage in FL. Their expression on progenitors is first detected at 6 wk and shows a progressive increase through 9 wk, up to greater than or equal to 50% of adult values. A similar expression pattern is observed for FL erythroblasts. Incubation of 6-wk FL erythroid cells with IFN-alpha, -beta, or -gamma, or TNF-alpha induces a sharp rise of the expression of HLA class I, but not HLA class II Ag on both progenitors and precursors. In contrast, incubation with PHA-stimulated adult leukocyte-conditioned medium causes a marked increase of both HLA-ABC and HLA class II Ag expression. We hence investigated the effect of cytokines present in leukocyte-conditioned medium on the expression of HLA class II Ag: although IL-1 alpha, IL-2, and granulocyte-macrophage-CSF do not exert a significant action, IL-1 beta and IL-4 induce a marked increase of HLA class II, but not class I, Ag expression on 6-wk FL progenitors and precursors. Low amounts of IFN-gamma, TNF-alpha, and IL-1 beta were detected in the supernatants and extracts of 6-wk FL cells. The concentrations of these cytokines in both supernatants and extracts sharply increase in the 7- to 8-wk period, particularly for TNF-alpha and IL-1 beta, thus indicating a direct correlation with the rise of HLA Ag expression on FL erythroid cells in the same period. In conclusion, the expression of HLA class I and II Ag is not detected on primitive megaloblasts, but is gradually induced on definitive FL progenitors and precursors, possibly via production of specific cytokines in the FL microenvironment, i.e., IFN-gamma and TNF-alpha for class I Ag and IL-1 beta for class II Ag.

Biological Factors↗