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Biomedical subjects

M Bianchi

Publications and source records attributed to M Bianchi.

At least 19 recordsLinked to original sources

Central effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity.

To extend the knowledge on the central effects of cytokines, we studied the effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity in rats. After central administration, both tumor necrosis factor alpha and interleukin-1 alpha significantly (P < 0.001) increase the nociceptive thresholds as measured by the hot-plate test. Tumor necrosis factor alpha, but not interleukin-1 alpha decreases spontaneous locomotor activity evaluated by the Animex test. The increase in nociceptive thresholds induced by tumor necrosis factor alpha or interleukin-1 alpha is not affected by the opiate receptor antagonist naloxone, or antisera against the endogenous opioids beta-endorphin, met-enkephalin or dynorphin. The analgesic effect of tumor necrosis factor alpha is completely antagonized by anti-IL-1 antibodies. Moreover, the cyclooxygenase inhibitor indomethacin does not antagonize the increase of nociceptive thresholds induced by either cytokine.

Analgesia

Structure and expression of a gene from Arabidopsis thaliana encoding a protein related to SNF1 protein kinase.

The AKin10 gene from Arabidopsis thaliana encoding a putative Ser/Thr protein kinase (PK) has been isolated and characterized. The AKin10-encoding gene is located on a genomic 5.4-kb BamHI fragment and contains ten introns, one being located in the 5' untranslated region. The deduced amino acid sequence of AKin10 is 65% identical over the catalytic domain to the yeast PK (SNF1). SNF1 is essential for the derepression of many glucose-repressible genes, including Suc2 which encodes invertase. Southern blot hybridization experiments suggested the presence of one copy of the gene per haploid genome of A. thaliana. Northern hybridization experiments indicated that this gene is expressed in roots, shoots and leaves. AKin10 may play an important role in a signal transduction cascade regulating gene expression and carbohydrate metabolism in higher plants.

Amino Acid Sequence

Effects of two different reversible monoamine oxidase-A inhibitors on nociceptive thresholds in the rat.

The acute effect of two different reversible inhibitors of monoamine oxidase-A on nociceptive thresholds was evaluated in the rat by the tail-flick and hot-plate tests. CGP 11305-A, a monoamine oxidase-A inhibitor that also blocks serotonin reuptake, elicited an increase of latency in the tail-flick and the hot-plate test. Ineffective doses of CGP 11305-A increased nociceptive thresholds when administered in combination with other serotoninergic agents, i.e. chlorimipramine or 5-hydroxytryptophan, at doses that were ineffective alone. CGP 22364-A, a pure inhibitor of monoamine oxidase-A, increased latency only in the hot-plate test. Both compounds decreased spontaneous locomotor activity at the doses effective in the hot-plate test, suggesting that the responses observed in this test are not related to a pure effect on nociceptive thresholds. The data suggest that the increase in serotonin availability induced by monoamine oxidase-A inhibition alone is not sufficient to affect nociceptive thresholds.

Animals

A recombinant human 'mini'-hexokinase is catalytically active and regulated by hexose 6-phosphates.

Mammalian hexokinase type I is a 100 kDa enzyme that has been considered to be evolved from an ancestral 50 kDa yeast-type hexokinase, insensitive to product inhibition, by gene duplication and fusion. According to this model, and based on many experimental data, the catalytic site is associated with the C-terminal half of the enzyme, although an allosteric site for the binding of glucose 6-phosphate could be present on the N-terminal half of the molecule. We have isolated a cDNA clone of hexokinase from a lambda gt11 human placenta library comprising 2658 bp, containing a single open reading frame of 1893 nucleotides, which encodes a truncate form of hexokinase starting from asparagine-287 to the terminal serine-917. This clone was further digested with restriction enzyme NcoI to obtain almost only the C-terminal half of human hexokinase starting from methionine-455 to the terminal amino acid and was overexpressed in active form in Escherichia coli and purified by ion-exchange h.p.l.c. The overexpressed 'mini'-hexokinase was found not only to catalyse glucose phosphorylation, but also to be inhibited by glucose 6-phosphate and other mono- and bis-phosphate sugars exactly like the complete mammalian enzyme. These results suggest that the C-terminal half of human hexokinase, in addition to the catalytic site, also contains the regulatory site and that the evolutionary relationship between the hexokinases should be reconsidered by including the appearance of a regulatory site before the gene duplication.

Amino Acid Sequence

Molecular cloning of a cDNA coding for mouse liver xanthine dehydrogenase. Regulation of its transcript by interferons in vivo.

The cDNA coding for xanthine dehydrogenase (XD) is isolated from mouse liver mRNA by cross-hybridization with a DNA fragment of the Drosophila melanogaster homologue. Two lambda bacteriophage overlapping clones represent the copy of a 4538-nucleotide-residue-long transcript with an open reading frame of 4005 nucleotide residues, coding for a putative polypeptide of 1335 amino acid residues. Comparison of the deduced amino acid sequence of the mouse XD with those of the Drosophila and the rat homologues shows a high conservation of this protein (55% identity between mouse and Drosophila, and 94% identity between mouse and rat). RNA blotting analysis demonstrates that interferon-alpha (IFN-alpha) and its inducers, i.e. poly(I).poly(C), bacterial lipopolysaccharide (LPS) and tilorone (2,7-bis-[2-(diethylamino)ethoxy]fluoren-9-one), increase the expression of XD mRNA in liver. Poly(I).poly(C) also induces XD mRNA in several other tissues in vivo. Protein synthesis de novo is not required for the elevation of XD mRNA after IFN-alpha treatment, since cycloheximide does not block the induction. The elevation of XD mRNA concentration is relatively fast and precedes the induction of both XD and xanthine oxidase (XO) enzymic activities.

Amino Acid Sequence

ATP-stimulated glutamate-dependent calcium uptake by rat synaptosomes.

The entry of Ca2+ in rat synaptosomes was followed with a Ca(2+)-selective electrode. Extracellular ATP is necessary for the entry which is a function of synaptosomal protein, free Ca2+ and glutamate concentrations. Ketamine, glycine and kainate have negligible effect while quisqualate slightly inhibits the uptake of Ca2+ in the presence of glutamate. The added ATP is hydrolyzed by the synaptosomes through an ouabain-insensitive ecto-ATPase affected by the presence of Ca2+, glutamate and, to a slight extent, NMDA.

Adenosine Triphosphate

Added ATP influences some responses of rat synaptosomes to glutamate.

ATP added externally to rat synaptosomes activated uptake of both Ca2+ and glutamate which was partially accounted for by the uptake phenomena of synaptic vesicles and mitochondria, as shown by using specific inhibitors of the latter. Increasing concentrations of glutamate stimulated Ca2+ entry linearly, as shown by using 45Ca or a Ca-specific electrode. The processes of glutamate and Ca2+ uptake shared some common features and their ATP-dependence may be correlated with an ouabain-insensitive synaptosomal ectonucleotidase activity measured by a 31P-NMR or a luminometric technique. The ATP hydrolysis catalysed by the synaptosomes was activated by both Ca2+ and glutamate. The present synaptosomal activities may represent a model for studying the modulatory effects of ATP on the glutamatergic neurotransmission.

Adenosine Triphosphate

The pneumotoxicant paraquat potentiates IL-1 and TNF production by human mononuclear cells.

Interleukin 1 (IL-1) and tumor necrosis factor (TNF) have been implicated in the pathogenesis of bleomycin- and silica-induced lung damage. We have studied the effect of paraquat (PQ), a well-known pneumotoxicant, on IL-1 and TNF production by human peripheral blood mononuclear cells from different healthy donors stimulated with endotoxin. PQ (100 microM) potentiated IL-1 production (2-40 fold) and TNF production (2-18 fold). It is, therefore, possible that IL-1 and TNF are also involved in the pneumotoxic action of PQ.

Antibody Specificity

[Hodgkin's disease in childhood].

Only in these latest years has been possible to consider Hodgkin disease (HD) as a neoplastic syndrome, thank of immunohistochemistry and cytogenetic techniques which have confirmed the monoclonal origin of typical cellular marker of disease: the Reed-Sternberg cell (R-S cell). Interesting associations have been observed between children suffering from HD and the positivity of EBV antigen above all in the socio-economically developed countries. The histopathologic classification of HD is divided in four sub-types, with different incidence in the pediatric age: the nodular sclerosis and the mixed cellularity are more rap-presented than the lymphocyte predominance and mostly the lymphocyte depletion. Histopathologic classification is essential for the prognosis and a correct therapeutic approach to disease. The management of HD is based on chemotherapy and radiotherapy associated; the results of treatment are more and more encouraging with a global survival over 95%. Sequelae of treatment are reduced in modern therapeutic trials: in particularly injury to somatic growth, cardiopulmonary system, gonadal and thyroid functionality is reduced by using low dose and involved fields for the early stage patients. The most important sequela in children treated for HD is the risk to developed a second malignant neoplasm; in particularly acute nonlymphocytic leukemia and non Hodgkin's lymphoma. In patients treated with radiotherapy alone increase the risk to develop solid tumors like sarcomas and carcinomas, which can appears several years after diagnosis.

Child

The Elmslie-Trillat procedure for recurrent subluxation of the patella. One to five year follow-up.

Thirty-four patients who had undergone the Elmslie-Trillat procedure from 1985 to 1989 were examined in order to evaluate the effectiveness of this operation in the treatment of recurrent subluxation of the patella. The result of an increased Q angle accompanied by patella alta, femoral sulcus dysplasia, or vastus medialus obliquus dysplasia was also studied. Only those patients with recurrent subluxation of the patella took part in this study; cases of habitual or permanent dislocation, potential instability, traumatic dislocation, and degenerative arthritis were excluded. The patients were reviewed both clinically and radiographically, and the A.R.P.E.G.E. scoring system was used to evaluate the results. The follow-up period ranged from 1 year to 5 years and 4 months, with an average of 3 years. The overall results were excellent or good in 77% of the cases, as was the subjective knee stability rating in 87% of the cases and the pain rating in 82% of the cases. Recurrence of the subluxation was observed in only one instance. The results were not significantly different when the groups of patients with patella alta and type 1 femoral sulcus dysplasia were considered separately. The results were also excellent in the patients who underwent the Elmslie-Trillat procedure with reconstruction of the vastus medialis obliquus. In conclusion, surgical realignment of the anterior tibial tubercle confirmed its reliability in the treatment of recurrent subluxation of the patella. In cases of patella alta, the authors recommend lowering the anterior tibial tubercle only when the Insall-Burstein index is greater than 1.3. Femoral sulcus-plasty should be performed in cases of type 3 sulcus dysplasia.

Adolescent

[A laparoscopic approach to a paratyphoid ovarian abscess].

A case report of a 29-year-old nulligravid patient with a ovarian typhoid abscess managed endoscopically is presented. Puncture and drainage of the pelvic mass was performed laparoscopically. The infrequency of Salmonella paratyphi as an etiologic agent of pelvic inflammatory disease is discussed and a review of the literature regarding endoscopic management of purulent pelvic collections is presented.

Abscess

[Symptomatic effect of epomediol in patients with cholestasis of pregnancy].

Epomediol is a terpenoid that prevents and reverses cholestasis induced by ethinylestradiol in the rat, apparently by improving liver cell membrane fluidity. Assuming that the pathogenesis of intrahepatic cholestasis of pregnancy (ICP) is related with increased estrogen levels, we studied the effects of epomediol in this disease. Patients hospitalized due to ICP received epomediol 900 mg/day (n = 7), or 1,200 mg/day (n = 4) orally, during 15 days. Biochemical parameters of liver dysfunction (serum bilirubin, bile salts, aminotransferase, alkaline phosphatases) were not modified during nor after epomediol administration. The severity of pruritus was significantly reduced in comparison to pretreatment status, with both doses of epomediol. A greater amelioration of pruritus was observed in patients treated with epomediol 1,200 mg/day than in patients who received 900 mg/day (to 20.7 +/- 6.2, as percent of pre-treatment severity score, versus 48.8 +/- 7.5 respectively; p < 0.05). After epomediol administration was stopped, pruritus relapsed in 6 patients; 3 of them had received the higher drug dose. After delivery, pruritus vanished and liver function tests returned to normal, in all patients. No adverse effects attributable to the drug were observed in the mothers or in their babies. The beneficial effect of epomediol on pruritus in patients with ICP appeared greater in this study than that observed recently in similar patients who received a placebo.

Bile Acids and Salts

Genu recurvatum following distal epiphysiodesis of the femur: X-ray evaluation and therapeutical approach.

UNLABELLED: Acquired genu recurvatum may have bone, capsulo-ligamentous or combined origins. It may affect the tibia or femur and various etiologies are possible. However, its pathogenesis is often linked to partial anterior epiphysiodesis following traumatic damage to the femoral or tibial growth plate. In this study we examine femoral recurvatum, a form which occurs only rarely. The clinical and radiographic characteristics are described in depth and the surgical indications for correction of this deformity are defined. Radiographic examination was used to complete the goniometry of the recurvatum deformity by calculating the dia-intercondylar angle, measureable on lateral radiographs of the knee. The normal value is 33 degrees (+/- 3 degrees) while in the patients with femoral recurvatum it was noticeably higher. In cases of isolated femoral recurvatum we carried out a supra-condylar osteotomy with removal of a bone wedge aimed at normalizing the dia-intercondylar angle. In the cases treated at our Centre, the objective, subjective, functional and radiographic results were good, with a mean follow-up of 6 years. CLINICAL IMPORTANCE: as well as completing the goniometry of the recurvatum, the dia-intercondylar angle makes it possible to draw up a correct pre-operative plan, enabling precise surgical correction to be carried out.

Activities of Daily Living

Increased glucose metabolism by enzyme-loaded erythrocytes in vitro and in vivo normalization of hyperglycemia in diabetic mice.

The main metabolic properties of human red blood cells (RBC) overloaded with glucose catabolizing enzymes such as hexokinase and glucose oxidase were evaluated. Human erythrocytes loaded with human hexokinase metabolized 3.1 +/- 0.2 mumol/h/ml RBC of glucose, an amount double that consumed by normal and unloaded cells (1.46 +/- 0.16 mumol/h/ml RBC), while glucose oxidase-loaded erythrocytes consumed up to 5.5 +/- 0.5 mumol/h/ml RBC of glucose but with a time-dependent increase in methemoglobin formation due to the H2O2 produced in the glucose oxidase reaction. This methemoglobin production was greatly reduced while glucose consumption was increased (8.1 +/- 0.4 mumol/h/ml RBC) by coentrapment of hexokinase and glucose oxidase. Similar results were obtained in mouse red blood cells, although the role of hexokinase was less pronounced due to a higher basal level of this enzyme. When administered to diabetic mice the hexokinase/glucose oxidase-overloaded erythrocytes had a circulating half-life of 5 days and were able to regulate blood glucose at near physiological levels. A single intraperitoneal administration of 500 microliters of enzyme-loaded cells maintained a near-normal blood glucose concentration for 7 +/- 1 days, while repeated administrations at 10-day intervals were effective in the regulation of blood glucose levels for several weeks. These results suggest that enzyme-loaded erythrocytes can behave as circulating bioreactors and can provide a new way to reduce abnormally elevated blood glucose.

Animals