Expression of wild-type and V210I mutant prion protein in human neuroblastoma cells

The conversion of the host-encoded prion protein (PrPc) into the insoluble, protease-resistant isoform (PrPsc) is the main pathogenic mechanism of transmissible spongiform encephalopathies. They are fatal neurodegenerative disorders, which in human occur as sporadic, inherited or familial forms. These last forms are linked to insert or point mutations of PrPc which may facilitate the spontaneous conversion into PrPsc. We have established stably transfected human neuroblastoma cells (SH-SY5Y) expressing mutant V210I, or wild-type PrPc. Both proteins were expressed and attached to the cell surface. The mutation in position 210 did not alter the biochemical properties of the protein in comparison with the wild-type protein nor induced any conformational changes similar to those observed in PrPsc.

STAT1 activation during monocyte to macrophage maturation: role of adhesion molecules

Human monocytes isolated from peripheral blood of healthy donors show a time-dependent differentiation into macrophages upon in vitro cultivation, closely mimicking their in vivo migration and maturation into extravascular tissues. The mediator(s) of this maturation process has not been yet defined. We investigated the involvement of signal transducers and activators of transcription (STAT) factors in this phenomenon and reported the specific, time-dependent, activation of STAT1 protein starting at day 0/1 of cultivation and maximally expressed at day 5. STAT1 activity was evident on the STAT binding sequences (SBE) present in the promoters of genes which are up-regulated during monocyte to macrophage maturation such as FcgammaRI and ICAM-1, and in the promoter of the transcription factor IFN regulatory factor-1. Moreover, the effect of cell adhesion to fibronectin or laminin was studied to investigate mechanisms involved in STAT1 activation. Compared with monocytes adherent on plastic surfaces, freshly isolated cells allowed to adhere either to fibronectin- or laminin-coated flasks exhibited an increased STAT1 binding activity both in control and in IFN-gamma-treated cells. The molecular events leading to enhanced STAT1 activation and cytokine responsiveness concerned both Y701 and S727 STAT1 phosphorylation. Exogenous addition of transforming growth factor-beta, which exerts an inhibitory effect on some monocytic differentiation markers, inhibited macrophage maturation, integrin expression and STAT1 binding activity. Taken together these results indicate that STAT1 plays a pivotal role in the differentiation/maturation process of monocytes as an early transcription factor initially activated by adherence and then able to modulate the expression of functional genes, such as ICAM-1 and FcgammaRI.

Activation and repression of the 2-5A synthetase and p21 gene promoters by IRF-1 and IRF-2

The Interferon Regulatory Factors-1 and -2 (IRF-1 and IRF-2) were originally identified as transcriptional regulators of the interferon (IFN) and IFN-stimulated genes. These factors also modulate immune response and play a role in cell growth regulation. In this study we analysed the effect of the ectopic expression of IRF-1 and IRF-2 on the regulation of two potential IRF target genes involved in cell growth regulation, 2-5A synthetase and p21 (WAF/CP1), both of which contain consensus binding sites for IRF family members within their promoters. Following ectopic expression, IRF-1 transactivated 2-5A synthetase and p21 genes, an effect that was counterbalanced by concomitant ectopic expression of IRF-2. These effects were mediated by direct binding of IRF to the gene promoters. A construct expressing an IRF-2 antisense (FRI-2) was able to revert the inhibitory effect of IRF-2 on the IRF-1 transactivation. IRF-1 also induced expression of its homologous repressor IRF-2 as indicated by EMSA analysis using an IRF-E probe from the IRF-2 promoter; and by cotransfection of IRF-1 together with an IRF-2 promoter CAT construct. Therefore, the induction of IRF-1 by IFNs or other stimuli acts as a transactivator of genes involved in cell growth regulation, as well as of its own repressor IRF-2, thus providing autoinhibitory regulation of IRF-1 activated genes.

Interleukin-12 induces expression of interferon regulatory factor-1 via signal transducer and activator of transcription-4 in human T helper type 1 cells

IRF-1-deficient mice show a striking defect in the development of T helper 1 (Th1) cells. In the present report, we investigate the expression of IRF-1 during differentiation of human T helper cells. No significant differences of IRF-1 mRNA expression were found in established Th1 and Th2 cells; however, interleukin 12 (IL-12) induced a strong up-regulation of IRF-1 transcripts in Th1 but not in Th2 cells. We demonstrate that IL-12-induced up-regulation of IRF-1 is mediated by signal transducer and activator of transcription-4, which binds to the interferon (IFN)-gamma-activated sequence present in the promoter of the IRF-1 gene. Strong IL-12-dependent activation of a reporter gene construct containing the IRF-1 IFN-gamma-activated sequence element provides further evidence for the key role of signal transducer and activator of transcription-4 in the IL-12-induced up-regulation of IRF-1 transcripts in T cells. IRF-1 expression was strongly induced after stimulation of naive CD4(+) T cells via the T cell receptor, irrespective of the cytokines present at priming, indicating that this transcription factor does not play a major role in initiating a Th1-specific transcriptional cascade in differentiating helper T cells. However, our finding that IRF-1 is a target gene of IL-12 suggests that some of the IL-12-induced effector functions of Th1 cells may be mediated by IRF-1.

The activity of the CCAAT-box binding factor NF-Y is modulated through the regulated expression of its A subunit during monocyte to macrophage differentiation: regulation of tissue-specific genes through a ubiquitous transcription factor

In this study, we analyzed the regulation of NF-Y expression during human monocyte to macrophage maturation. NF-Y is a ubiquitous and evolutionarily conserved transcription factor that binds specifically to the CCAAT motif present in the 5' promoter region of a wide variety of genes. We show here that in circulating monocytes, NF-Y binding activity is not detected on the CCAAT motif present in the promoters of genes such as major histocompatibility complex (MHC) class II, gp91-phox, mig, and fibronectin, whereas during macrophage differentiation, a progressive increase in NF-Y binding activity is observed on these promoters. Analysis of NF-Y subunit expression indicates that the absence of NF-Y activity in circulating monocytes is caused by a lack of the A subunit. Furthermore, addition of the recombinant NF-YA subunit restores NF-Y binding. We show that the lack of NF-YA protein is due to posttranscriptional regulation and not to a specific proteolytic activity. In fact, NF-YA mRNA is present at the same level at all days of monocyte cultivation, whereas the protein is absent in freshly isolated monocytes but is progressively synthesized during the maturation process. We thus conclude that the NF-YA subunit plays a relevant role in activating transcription of genes highly expressed in mature monocytes. In line with this conclusion, we show that the cut/CDP protein, a transcriptional repressor that inhibits gpc91-phox gene expression by preventing NF-Y binding to the CAAT box, is absent in monocytes.

Synergistic stimulation of MHC class I and IRF-1 gene expression by IFN-gamma and TNF-alpha in oligodendrocytes

In order to understand the molecular basis of the synergistic action of interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) on rat oligodendrocyte development, we studied some aspects of the signalling pathways involved in the regulation of the major histocompatibility complex (MHC) class I and the interferon regulatory factor 1 (IRF-1) gene expression. Two well-defined inducible enhancers of the MHC class I gene promoter, the MHC class I regulatory element (MHC-CRE) and the interferon consensus sequence (ICS), were analysed. Neither IFN-gamma nor TNF-alpha was capable of inducing MHC-CRE binding activity when administrated alone. Following the exposure of oligodendrocytes to IFN-gamma, TNF-R1 expression was transcriptionally induced by the binding of signal transducer and activator of transcription (STAT-1) homodimers to the IFN-gamma activated site (GAS) present in the gene promoter. The upregulation of TNF-R1 allowed TNF-alpha to induce the binding of nuclear factor-kappaB (NF-kappaB) to the MHC-CRE site. With respect to ICS element, IFN-gamma induced IRF-1 binding, that was further enhanced upon co-treatment with TNF-alpha. The existence of a synergism between IFN-gamma and TNF-alpha in stimulating IRF-1 expression at the transcriptional level was supported by IRF-1 promoter analysis: IFN-gamma directly induced the binding of STAT-1 homodimers to the GAS element, while NF-kappaB binding to the kappaB sequence was activated by TNF-alpha only after IFN-gamma treatment. This transcriptional regulation of IRF-1 gene by IFN-gamma and TNF-alpha was confirmed at the mRNA level. The synergism demonstrated in the present study highlights the importance of cytokine interactions in magnifying their biological effects during brain injury and inflammation.

[The tonsils and adenoids as a site of infection and the cause of obstruction]

The failure to eradicate group A beta-hemolytic streptococci from the pharynx is partly due to a low compliance, but above all, an alteration of the oropharyngeal microbiological flora: reduction of alpha-haemolytic streptococci which inhibit group A beta-hemolytic streptococci and increase of microorganisms such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis. These latter act indirectly destroying the beta-lactamic ring of penicillins. However, this obstacle is overcome by the use of antibiotics which do not contain beta-lactamic rings such as macrolides or associating amoxicillin with clavulanic acid or with new cephalosporins which are more resistant to beta lactamases. To restrict the diffusion of resistance to antibiotics, it is essential to limit their use diagnosing streptococcal tonsillopharyngitis more precisely, thanks to an improved use of micro-biological diagnostic tests and by a more extended use of tonsillectomy in recurrent tonsillitis (more than 6-7 in 1-2 years). Adenoiditis is closely related to the post nasal drip syndrome, to recurrent otitis media and to otitis media with effusion. All these situations could, therefore, represent an indication, although not well defined, for adenoidectomy. Nasopharyngeal obstruction due to adeno-tonsillar hypertrophy becomes critical during sleep when the hypotony of the upper airway muscles becomes additional to the anatomical obstruction. At this point the inspiratory effort required and the consequent decrease of intra airway pressure increase the pharyngeal obstruction suctioning the pharyngeal walls toward the median line. The resulting clinical picture is defined as sleep-disordered breathing (SDB) due to adenotonsillar hypertrophy (idiopathic), to be distinguished from SDB due to cranio-facial abnormalities or neuromuscular diseases. SDB includes both the more serious sleep apnea syndrome and the less severe upper airway respiratory resistance syndrome. A combination of symptoms and clinical data detectable both while awake or asleep, make the diagnosis simple. During sleep, both apnea and paradoxical inspiratory movements are highly specific while snoring is highly sensitive. To evaluate nasopharyngeal obstruction radiography and optic fibre endoscopy are both equally reliable. The gold standard test for non idiopathic SDB is the polysomnography, whereas for SDB, due to adenotonsillar hypertrophy, one is limited today to the recording during sleep of O2 saturation or of end tidal CO2. These investigations are, however, generally used up to 2 years of age, when the decision to carry out an adenoidectomy and especially a tonsillectomy is more difficult because of the greater risks which surgery involves at this age. The pharmacological therapy has a purely palliative function and is based on antibiotics, local vasoconstrictors, steroids and theophylline which acts more as an antiflogistic than as a breath stimulant. O2 therapy and nasal continuous positive airway pressure (CPAP) give better results, but are more difficult to carry out, in particular on a long term basis. Adenoidectomy especially if associated with tonsillectomy, leads to the resolution of the symptoms, but not always to a normalization of functional alterations (hypoxia and hypercapnia). For this reason, it is necessary to act on other factors which cause oedema of the nasopharyngeal mucosa contributing to the obstruction. In this area, the prevention of viral infections can be achieved by vaccination against influenza and by preventing the child from attending crowded day care centers. With regard to allergic inflammation, skin prick tests could be a first step in view of allergens avoidance measures. With regard to indoor air pollution, passive smoke must be stopped and the child kept out of the kitchen.

The influence of clinical and biomechanical factors on the results of valgus high tibial osteotomy

The results of the surgical treatment of valgus high tibial osteotomy were studied based on clinical and radiographic assessment and gait-analysis in 21 patients affected with arthrotic varus knee. Although tibial osteotomy has been in use for some time now, the reasons for its frequent failure are still not fully understood. A statistical analysis of the clinical and biomechanical parameters taken into account in this study have shown that hypercorrection in valgus is required to unload the medial compartment and to prevent the recurrence of deformity in varus and pain. Walking with the limb extrarotated may also be a compensatory mechanism, in order to reduce the adductor moment in the knee and overloading of the medial compartment.

Regulation of expression of ferritin H-chain and transferrin receptor by protoporphyrin IX

The effect of protoporphyrin IX (hemin without iron) on the expression of transferrin receptor and ferritin was investigated in Friend leukemia cells. Cells treated with protoporphyrin IX exhibit enhanced transferrin-receptor expression and markedly reduced ferritin synthesis. Stimulation of transferrin-receptor expression is observed at both the mRNA and protein level. The effect on ferritin synthesis is mediated by translational inhibition of the mRNA, which, in contrast, is transcriptionally stimulated by protoporphyrin IX treatment. The regulation of transferrin receptor and ferritin in response to iron perturbations has been studied extensively and is mediated by the binding of iron-regulatory proteins (IRP) to the iron-responsive elements (IRE) present in the 3' and 5' untranslated regions of the transferrin-receptor and ferritin mRNA, respectively. To elucidate the molecular mechanisms underlying the effects of protoporphyrin IX on ferritin and transferrin-receptor expression, the role of the IRE sequence was investigated both in vivo by transfection experiments, with a construct containing the coding region for the chloramphenicol acetyltransferase (CAT) reporter gene under the translational control of the ferritin IRE, and in vitro by RNA band-shift assays. Whereas, examination of IRP binding to the IRE by in vitro assays suggests an apparent inactivation of IRP by protoporphyrin IX treatment, CAT assays indicate that protoporphyrin IX is able to induce in vivo a translational inhibition similar to that obtained by treatment with the iron chelator Desferal. This observation raises the possibility of different effects on the IRP activity exerted by porphyrin treatment in intact tissue-culture cells and in vitro. We conclude that translation of ferritin mRNA and degradation of transferrin-receptor mRNA are inhibited in intact tissue-culture cells by protoporphyrin IX through a mechanism similar to that exerted by iron chelation, thus involving depletion of the intracellular iron pool. These results can improve the understanding of the regulation of ferritin gene expression in some pathological conditions associated with disturbed heme synthesis.

Faecal elastase 1 in children with cystic fibrosis

Recently, a new ELISA kit for determination of elastase 1 in faeces has become commercially available. Studies in patients with chronic pancreatitis have indicated that it is a simple and sensitive test of exocrine pancreatic function. The aim of this study was to assess the clinical value of this new test in cystic fibrosis. A total of 72 children were studied: 27 who were healthy, 22 with cystic fibrosis and 23 with non-pancreatic disorders. Oral pancreatic extracts were not discontinued in the children with cystic fibrosis. A small sample of faeces was collected from each subject for elastase 1 concentration and chymotrypsin activity determination. In all of the healthy children and most of those with non-pancreatic disorders (20/23), elastase 1 concentrations were greater than 500 microg/g; in contrast, the vast majority (20/22) of children with cystic fibrosis had very low values (less than 20 microg/g). The differences between children with cystic fibrosis and the other two groups were highly significant (P < 0.001). With a cut-off level of 132 microg/g, the sensitivity and specificity of faecal elastase 1 for the determination of exocrine pancreatic insufficiency were 96% and 100%, respectively. The specificity of faecal chymotrypsin was 96%, but its sensitivity was not calculated since the children with cystic fibrosis continued to take pancreatic extracts during the study.

CONCLUSION

The determination of faecal elastase 1 concentration is a simple and reliable means of assessing exocrine pancreatic function in children with cystic fibrosis. Results are not influenced by non-pancreatic disorders or by enzyme supplementation.

Genetic history of cystic fibrosis mutations in Italy. I. Regional distribution

Earlier analysis of the Italian population showed patterns of genetic differentiation that were interpreted as being the result of population settlements going back to pre-Roman times. DNA disease mutations may be a powerful tool in further testing this hypothesis since the analysis of diseased individuals can detect variants too rare to be resolved in normal individuals. We present data on the relative frequencies of 60 cystic fibrosis (CF) mutations in Italy and the geographical distribution of the 12 most frequent CF mutations screened in 3492 CF chromosomes originating in 13 Italian regions. The 12 most frequent mutations characterize about 73% of the Italian CF chromosomes. The most common mutation, delta F508, has an average frequency of 51%, followed by N1303K and G542X, both with average frequencies around 5%. Multivariate analyses show that the relative frequencies of CF mutations are heterogeneous among Italian regions, and that this heterogeneity is weakly correlated with the geographical pattern of non-DNA 'classical' genetic markers. The northern regions are well differentiated from the central-southern regions and within the former group the western and eastern regions are remarkably distinct. Moreover, Sardinia shows the presence of mutation T338I, which seems absent in any other European CF chromosome. The north-western regions of Italy, characterized by the mutation 1717-1G-->A, were under Celtic influence, while the north-east regions, characterized by the mutations R1162X, 2183AA-->G and 711 + 5G-->A, were under the influence of the Venetic culture.

[Response to bronchodilator administered directly with spray or with spacer]

If we assume that the only function of a spacer is that to facilitate the esecution of a spray, its use is limited to small children who do not collaborate (below age 6-7 years). However, spacers seem to improve the effectiveness of drugs and reduce both directly and indirectly the side effects. The assess if these characteristics have a role in clinical practice, the response to 100 micrograms of salbutamol administered directly by Autohaler was compared to that obtained with the same dose administered with three different spacers, Aerochamber, Babyhaler, Volumatic. A series of 88 asthmatic subjects with a FEF 25-75 less than 70% of the predicted value was considered. Overall patients provided 118 responses to the bronchodilator: 17 using the Aerotec (Autohaler), 38 the Aerochamber, 33 the Babyhaler, 30 the Volumatic. The response was evaluated considering the parameters obtained by spirometry just before, 5 and 20 minutes after the inhalation of salbutamol. Heart rate was also measured at the same time points. Heart rate, but not spirometric parameter were increased by the use of the Autohaler, proving that the drug had been inhaled. All the spacers determined a significant increase in the parameters considered. No significant difference was detected among spacers, although the smallest (Aerochamber, Babyhaler) showed a trend to a better response, in particular before age 7 years. The complete ineffectiveness of direct inhalation and the excellent response to inhalation with spacers show the indispensability of the latter, independent of age. Although no substantial difference among spacers was detected, the trend to obtain a better response with smaller spacers inclines us to use them in particular between 4 and 7 years of age. The negative correlation between the increase in spirometric parameters and the age of the patient would allow to have doses aimed to age or to body weight.

Transcriptional regulation of the ferritin heavy-chain gene: the activity of the CCAAT binding factor NF-Y is modulated in heme-treated Friend leukemia cells and during monocyte-to-macrophage differentiation

The ferritin H-chain gene promoter regulation was analyzed in heme-treated Friend leukemia cells (FLCs) and during monocyte-to-macrophage differentiation. In the majority of cell lines studied, the regulation of ferritin expression was exerted mostly at the translational level. However, in differentiating erythroid cells, which must incorporate high levels of iron to sustain hemoglobin synthesis, and in macrophages, which are involved in iron storage, transcriptional regulation seemed to be a relevant mechanism. We show here that the minimum region of the ferritin H-gene promoter that is able to confer transcriptional regulation by heme in FLCs to a reporter gene is 77 nucleotides upstream of the TATA box. This cis element binds a protein complex referred to as HRF (heme-responsive factor), which is greatly enhanced both in heme-treated FLCs and during monocyte-to-macrophage differentiation. The CCAAT element present in reverse orientation in this promoter region of the ferritin H-chain gene is necessary for binding and for gene activity, since a single point mutation is able to abolish the binding of HRF and the transcriptional activity in transfected cells. By competition experiments and supershift assays, we identified the induced HRF as containing at least the ubiquitous transcription factor NF-Y. NF-Y is formed by three subunits, A, B, and C, all of which are necessary for DNA binding. Cotransfection with a transdominant negative mutant of the NF-YA subunit abolishes the transcriptional activation by heme, indicating that NF-Y plays an essential role in this activation. We have also observed a differential expression of the NF-YA subunit in heme-treated and control FLCs and during monocyte-to-macrophage differentiation.

[Update on treatment of asthma]

Treatment of asthma, in particular long-term therapy, has continued to evolve both for the perfectioning of single classes of drugs and for a better addressed long-term treatment, although physicians have not disposed of new drugs for over 30 years. Only with regard to chromones expectations have been disappointing, as the new nedocromil showed substantially the same efficacy as the old chromoglycate. The recent availability, in paediatrics, of long-acting beta 2 agonists, especially salmeterol, represents a big advantage with regard to compliance in therapies which last months, while the most recent corticosteroid, available in Italy as a spray, fluticasone, would have very few side effects. Principally this is due to the scarce intestinal absorption which is nearly non-existent. An old drug, such as theophylline, has been rediscovered because of the recent evidence of an antiinflammatory action. This is confirmed by the good results obtained when it is used for very long periods instead of inhaled corticosteroids. The therapeutical schemes of asthma have been modified since asthma has been demonstrated to be characterized more by phlogosis of the bronchial mucosa which persists after an acute episode rather than by broncho-constriction. This necessarily requires long-term therapies with antiinflammatory drugs which must be stepwise. In fact, the absence of an ideal drug determines the use of the drug with the fewest side effects in the less severe forms, i.e. chromones although less active, and of inhaled corticosteroids at increasing doses up to steroids per os in the more severe forms. Classical protocols suggest the combination with a beta 2-agonist (when necessary up to 3-4 times per day) to use corticosteroids as little as possible. However, recently short beta 2 agonists are being substituted by long-acting preparation which must be regularly administrated in the morning and evening.

Cystic fibrosis: MR assessment of pancreatic damage

PURPOSE

To evaluate magnetic resonance (MR) imaging for assessment of pancreatic damage in cystic fibrosis.

MATERIALS AND METHODS

Twenty-seven patients with cystic fibrosis and 12 control subjects underwent T1-weighted imaging for visual assessment for pancreatic hyperintensity and mixed spin-echo-inversion-recovery imaging for quantitative measurement of T1. Pancreatic insufficiency, pulmonary status, and genotype were recorded. Statistical correlation was conducted.

RESULTS

Four patterns of pancreatic involvement were noted: diffuse hyperintensity with a lobular pattern, diffuse homogeneous hyperintensity without residual lobular pattern, hyperintensity with focal areas of sparing, and no structural or signal intensity changes. Statistically significant reduction of the T1 was noted in 21 patients compared with that of controls. Statistically significant correlation between T1 shortening and pulmonary clinical-radiologic compromise and pancreatic insufficiency was found.

CONCLUSION

MR imaging may offer further indication of pancreatic and, indirectly, pulmonary damage during the clinical course of cystic fibrosis. A pattern of fibrofatty infiltration of the pancreas, of undetermined clinical significance, is reported.

Regulation of ferritin H-chain expression in differentiating Friend leukemia cells

The mechanisms that regulate the expression of ferritin, the iron storage protein, have been investigated in Friend erythroleukemia cells (FLCs) induced to differentiate by several chemical compounds. In differentiating FLCs, administration of hemin increases the steady-state level of ferritin mRNA about 15-fold and the ferritin content about 20- to 25-fold. Conversely, iron salts have only mild stimulatory effects on these parameters and iron chelators only slightly inhibited the stimulatory effect of hemin. Transient transfection experiments with a construct in which the human ferritin H-chain promoter drives the expression of the indicator chloramphenicol acetyltransferase (CAT) gene show that the increase in mRNA content is mainly due to enhanced transcription. In addition to transcriptional effects, translational regulation resulting in the further increase in ferritin synthesis is shown by CAT assays from cells transiently transfected with a construct containing the coding region for the indicator CAT mRNA under the translational control of the mRNA ferritin iron-responsive element. We conclude that, in FLCs induced to differentiate, hemin acts synergistically with the differentiation inducers, increasing ferritin expression. Both transcriptional and translational mechanisms are responsible for this synergistic effect, which appears to be characteristic of differentiated erythroid cells because it is not observed in other cell types (ie, fibroblastic cell lines).

Cells resistant to interferon-beta respond to interferon-gamma via the Stat1-IRF-1 pathway

The mechanism responsible for the induction of the 2-5A synthetase gene by Interferon-gamma (IFN-gamma) (type II) was studied in Friend leukemia cells. It was previously shown that activation of 2-5A synthetase gene expression by IFN-gamma in the 3Cl8 cell, a clone resistant to IFN-alpha,beta (type I), correlates with the formation of two major complexes, designated Fg and Fc, that bind to the interferon-stimulated responsive element of the gene. Conversely, in a clone resistant to both types of IFNs (3 gamma R8), no induction of DNA-protein complexes or of 2-5A synthetase gene expression was detected. In the present report the Fg complex has been characterized as including the interferon regulatory factor 1 (IRF-1), whereas the Fc factor, present also in control cells, has been characterized as composed of IRF-2. Incubation of cell extracts with antibodies to IRF-1 abolishes the formation of the Fg complex, and antibodies to IRF-2 abolish the formation of the Fc complex. Moreover, in the 3Cl8 cell, IFN-gamma is able to induce in few minutes the formation of a complex between a DNA element identified as the IFN-gamma activation site (GAS), present on the IRF-1 gene promoter, and the STAT1 protein. These findings suggest that in cells resistant to type I IFN, IFN-gamma is able, through the activation of the STAT1 protein, to induce the expression of the IRF-1 factor which in turn seems to be sufficient to transactivate the 2-5A synthetase gene.

[Prevalence of group B beta-hemolytic Streptococcus colonization in a sample of 23,312 pregnant women and newborn infants]

We report the prevalence of colonization of Group B Streptococci in a given population referred to a limited area in the north-west of Italy. 23.312 pregnant women were tested. Group B Streptococci have been isolated from genital cultures in 0.18-13.2% (mean 8.18). The prevalence of Group B streptococcal colonization from ear, throat and ocular cultures of newborn infants from colonized mothers was 11.55%. Incidence of infection in neonates has varied from 0 to 2.33% (1.5 per 1000 live births).

[How best to perform aerosol therapy. 2. Drugs]

The individuation of a 5:1 ratio for the posology of beta 2-agonist drugs administered respectively by nebulizer or as a spray plus a spacer, allows the use of these drugs by the latter way also during an acute attack of bronchospasm. Other qualifying aspects of beta 2-agonist are the possibility of increasing the dose up to a continuous administration in case of a severe attack of bronchoconstriction and the demonstrated clinical efficacy of these drugs during the first year of life. The question of the correct dose to administer according to the age of the patient appears to be rather complex: in fact if on the one hand during the first months of life the low tidal volume (VT) can reduce the quantity of drug inhaled, on the other the low pulmonary volumes (FRC) of the first years of life determine a lesser dilution of the inhaled drug and therefore a greater pulmonary concentrations. Among corticosteroids for inhalation, the ones with the fewer side effects should be chosen: these may appear although in a subclinical fashion at relatively low doses of about 400 micrograms/day of beclomethasone. The most frequent indication for an antibiotic treatment by inhalation is represented by chronic pulmonary infection caused by bacteria sensible only to parenteral antibiotics (for ex. Pseudomonas infection in cystic fibrosis). The extremely high cost of these treatments requires the use of devices with a very high efficiency, in other words capable of nebulizing very large percentages of drug into small particles (< 6 microns).(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet markers in suicide attempters

1. The authors measured 3H-imipramine (3H-IMI) binding and serotonin (5HT) uptake parameters as well as sulphotransferase activity in platelets of suicide attempters. 2. Platelet 3H-IMI binding sites and 5HT uptake are related to similar sites and processes present in the brain, and sulphotransferase (ST) is an enzyme involved in the catabolism of cathecholamines. 3. The results showed the presence of a decreased density of both 3H-IMI binding and of 5HT uptake sites, with no change in ST activity in suicide attempters, as compared with healthy controls. 4. The reduced 3H-IMI binding and 5HT uptake may be related to a hypofunction of presynaptic serotonergic mechanisms which might be altered in suicidal behavior.

Hemin inhibits the interferon-beta-induced antiviral state in established cell lines

Hemin and other metalloporphyrins are known as very versatile compounds in nature, because they are able to carry out numerous functions in a free state or in association with specific proteins. When Friend murine erythroleukemia cells are treated with IFN-beta plus 100 microM hemin, the antiviral state is not observed, whereas the antiviral effect of IFN-gamma is unaffected by hemin treatment. This inhibitory effect of hemin is not restricted to erythroid cells. In fact, it is also observed in murine L929 and in human cell lines treated with IFN-beta. Neither trivalent iron in other forms nor hemin analogs (such as protoporphyrin IX or Sn(2+)-protoporphyrine IX) mimic this effect. Conversely, Co(3+)-protoporphyrin IX was as effective as hemin. At the transcriptional level, results obtained by run-on assays on nuclei from IFN-treated cells indicate that hemin does not completely inhibit IFN-beta induction of 2-5A synthetase gene(s) at 6 h of treatment but abolishes it at 24 h. In addition, hemin is able to inhibit the accumulation of IFN-induced 2-5A synthetase mRNAs. Experiments carried out to investigate the hemin effect on the early steps of the IFN signaling pathway indicate that hemin interferes with the ability of type I IFN to bind to its receptor, probably by a direct action on the IFN molecule.

[The best way to apply aerosol therapy. I--Methods]

The dimension of the particles delivered by a compressor-nebulizer system and therefore the ability to penetrate in the distal lung, varies according to different nebulizers. Moreover the aerosol is better in quality higher the flow furnished by the compressors is. The quantity of drug inhaled is greater as lower the residual amount of liquid left in the nebulizer is: the latter is less in glass nebulizers than in plastic nebulizers. The ultrasonic inhaler does not present any qualitative or quantitative advantages respect to the pneumatic inhaler. A very important point in the execution of an aerosol is oral respiration. The administration of the drug through a mouthpiece does not present substantial differences respect to the use of a face mask kept in a vertical position and adherent to the face. Metered-dose inhalers shorten the time of performance, but an active cooperation is needed; moreover the quantity of drug that resides in the oropharynx increases and consequently adverse effects, too. These two obstacles are overcome by the use of spacers which are chosen on the basis of the child's age. Aerosolic treatment has been simplified by the use of powders for inhalation, but we do not always obtain correct inhaling flows in children, especially when they are bronchoobstructed. Therefore compressor or ultrasonic aerosol is more useful in bronchoobstruction, while metered-dose inhalers with spacers are more useful in long-term treatment. Powder is usually used in children over 6-7 years of age and excludes the use of important drugs, such as cortisone, which may present relevant adverse effects.

Differential regulation of ferritin expression in Friend leukemia cells by iron compounds

Ferritin is an ubiquitous iron storage protein that plays a key role in determining the intracellular fate of iron. Therefore, ferritin synthesis is highly regulated by the iron status of the cell through post-transcriptional mechanisms that involve a specific high-affinity interaction between an iron-responsive element (IRE) in the 5' untranslated region of ferritin mRNA and a 98 kDa cytoplasmic protein, the iron-regulatory factor (IRF). The mechanisms that regulate the expression of the iron storage protein ferritin were investigated in erythroid (Friend erythroleukemia cell, FLC) and fibroblastic (L929 and B6) cell lines after exposure to various iron compounds. Both hemin (ferric protoporphyrin IX) and iron (as ferric ammonium citrate, FAC) were used as inducers of ferritin synthesis. Administration of hemin increases ferritin synthesis 8-12 fold both in erythroid and in non-erythroid cell lines, whereas FAC is a weak inducer of ferritin in FLC (only 5-fold). These results correlate with ferritin mRNA expression in FLC observed after hemin treatment compared to the effect exerted by FAC administration. This differential effect suggests that heme is the physiological compound able to stimulate ferritin synthesis in erythroid cell lines and that it plays an important physiological role in regulating gene expression in developing erythroid cells.

Prognostic significance of serum lactate dehydrogenase in patients with osteosarcoma of the extremities

Six hundred and fifty-six patients with osteosarcoma of the extremities (107 metastatic and 549 with localized disease) were followed from 2.5 to 20 years (average: 10 years) to evaluate whether their pretreatment serum lactate dehydrogenase (LDH) enzyme levels had a clinical value in predicting the course of the disease. The percentage of patients who had an elevated serum LDH at the time of diagnosis was significantly higher in those patients with metastatic disease than those who had localized disease (64% versus 33%, p < 0.0001). For those who presented with localized disease and had an increased serum LDH level, far more ultimately developed a relapse of disease (60% versus 38%, p < 0.0001) than those patients with a normal pre-treatment value. The prognostic significance of the serum LDH was more pronounced for the 247 patients treated with adjuvant chemotherapy (relapse rate of 72% versus 48%; p < 0.0002) than the 271 patients treated with neoadjuvant chemotherapy (relapse rate: 46% versus 28%, p < 0.005). Following treatment, serum LDH levels almost uniformly returned to normal and no correlation between postoperative levels and relapse of disease could be identified. We have demonstrated that in patients with osteosarcoma of the extremities, pretreatment serum LDH levels have a definite prognostic value which should be considered when comparing the results achieved with different therapeutic protocols and in planning new randomized clinical trials.

Gait analysis in patients after Van Nes rotationplasty

Gait was analyzed through kinetic, kinematic, and temporal-distance parameters assessment to evaluate the functional performance of ten children treated by the classical Van Nes rotationplasty (VNR). Van Nes rotationplasty is a surgical procedure, which permits the conversion of the ankle joint into a "pseudo-knee" joint. The data were compared with measurements of a normal population of ten healthy subjects. Significant differences with respect to the normal were found in stride duration, stride length, cadence, velocity, and stance-swing ratio, and in ground-reaction forces parameters, which define the propulsive phase in the prosthetic side and the acceptance phase in the sound side. There were differences in some kinematic parameters as well. Van Nes rotationplasty is acceptable from a biomechanical-functional point of view, particularly with respect to the active control of the pseudo-knee, which allows a smooth and coordinate gait pattern.

Serum methotrexate (MTX) concentrations and prognosis in patients with osteosarcoma of the extremities treated with a multidrug neoadjuvant regimen

The relationship between the serum concentration of methotrexate and the prognosis has been studied in 108 patients with osteosarcoma of the extremities treated from September 1986 to December 1989 at the Chemotherapy Department of Rizzoli Hospital. The protocol of neoadjuvant chemotherapy included high doses of methotrexate (HDMTX) adriamycin, cisplatinum, ifosfamide and VP-16. After a median follow-up of 40.4 months (range 24-62), 84 (77.7%) of the patients studied remained continuously disease-free (CDF) and 24 relapsed. Significantly higher mean serum MTX concentrations were observed in the patients who remained CDF (669.5 mumol/l) than in the patients who relapsed (571.9 mumol/l) (p < .004). The breaking point of prognostic significance for the serum MTX levels seems to be 700 mumol/l. In fact, according to the mean MTX concentrations, the patients with less than 700 mumol/l showed a significantly lower disease-free survival than the patients with higher mean MTX concentrations (68.12% vs 94.87% p < .0013). The distribution of prognostic variables between the two groups was the same in terms of site and histological type of tumor and alkaline phosphatase serum levels at diagnosis. In the group which had more than 700 mumol/l MTX, a higher percentage of good histological response after primary chemotherapy was observed. This is probably independent from the MTX because no significant preoperative MTX serum levels between good and partially responding patients were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic significance of serum alkaline phosphatase measurements in patients with osteosarcoma treated with adjuvant or neoadjuvant chemotherapy

BACKGROUND

It is known that many patients with osteosarcoma have high serum alkaline phosphatase (SAP) levels. The prognostic significance of this finding, however, is still controversial.

METHODS

The pretreatment SAP levels of 656 patients with osteosarcoma of the extremities (107 metastatic and 549 localized at presentation) were examined to evaluate whether the enzyme levels had a clinical value in predicting the course of the disease.

RESULTS

The percentage of patients with increased SAP levels was significantly higher in the metastatic group than in the group of patients with localized disease (91.5% versus 61.3%; P < 0.001). In the latter group, treated with adjuvant and neoadjuvant chemotherapy, the relapse rate was significantly higher in patients with elevated pretreatment SAP levels than in those with normal levels (55.1% versus 26.4%; P < 0.001). Among patients with elevated SAP levels, the percentage of relapses was higher in patients with high levels of the enzyme in comparison with patients with moderately elevated values (66.4% versus 47%; P < 0.05). After treatment, SAP levels almost always return to normal values, and a correlation between postoperative levels of the enzyme and prognosis could not be made.

CONCLUSIONS

These data demonstrate that in osteosarcoma of the extremities, pretreatment SAP levels have a prognostic value and they should be considered when comparing the results achieved with different therapeutic protocols and in planning new randomized clinical trials.

[Osteosarcoma of the extremities metastatic at presentation. Results obtained with primary chemotherapy followed by simultaneous resection of the primary and metastatic lesion]

From September 1986 to September 1990 35 patients affected by osteosarcoma of the extremities with synchronous metastasis were treated with two cycles of high-dose methotrexate IV, cisplatin IA and adriamycin IV followed, in 22, by simultaneous resection of the primary and metastatic tumor. Six patients progressed and were not operated on, 7 patients with complete response of pulmonary nodules underwent surgical resection of the primary lesion. A complete histological examination of the resected specimens was always performed to evaluate the percentage of necrosis produced by chemotherapy on both the primary and metastatic tumor. After surgery the patients received 3 more cycles of the same drugs as used preoperatively plus ifosfamide. The histological response of the primary tumour was "good" (90% or more tumour necrosis) in 8 patients (27%) and "poor" (less than 90% of tumour necrosis) in 21 (73%) while in the 75 metastatic nodules the resulting necrosis was good in 18 (24%) and poor in 57 (74%). A good correlation between the histological response in the primary and metastatic tumour was observed. At an average follow-up of 30 months (R 12-60), 13 patients are alive, 10 disease-free, and 3 with uncontrolled disease. This data suggest that prognosis of osteosarcoma of the extremities with synchronous metastases remains poor even with a very aggressive treatment. Our results also seem to confirm the validity of the present strategy in the treatment of non metastatic osteosarcoma: to introduce new drugs postoperatively in patients poor responder can allows a better treatment of microscopic disease and can improve the prognosis for these patients.

Modulation of ferritin H-chain expression in Friend erythroleukemia cells: transcriptional and translational regulation by hemin

The mechanisms that regulate the expression of the H chain of the iron storage protein ferritin in Friend erythroleukemia cells (FLCs) after exposure to hemin (ferric protoporphyrin IX), protoporphyrin IX, and ferric ammonium citrate (FAC) have been investigated. Administration of hemin increases the steady-state level of ferritin mRNA about 10-fold and that of ferritin protein expression 20-fold. Experiments with the transcriptional inhibitor actinomycin D and transfection studies demonstrate that the increment in cytoplasmic mRNA content results from enhanced transcription of the ferritin H-chain gene and cannot be attributed to stabilization of preexisting mRNAs. In addition to transcriptional effects, translational regulation induces the recruitment of stored mRNAs into functional polyribosomes after hemin and FAC administration, resulting in a further increase in ferritin synthesis. Administration of protoporphyrin IX to FLCs produces divergent transcriptional and translational effects. It increases transcription but appears to suppress ferritin mRNA translation. FAC treatment increases the mRNA content slightly (about twofold), and the ferritin levels rise about fivefold over the control values. We conclude that in FLCs, hemin induces ferritin H-chain biosynthesis by multiple mechanisms: a transcriptional mechanism exerted also by protoporphyrin IX and a translational one, not displayed by protoporphyrin IX but shared with FAC.

[Ewing's sarcoma of the bone. Anatomoclinical study of 424 cases]

The clinic-epidemiologic and prognostic features of 424 cases of Ewing sarcoma observed at "Rizzoli" Institute between 1972-1990 are reported. The incidence of the tumor was higher in the second decade of life with slight predominance in the male sex. The primary lesion was especially localized in the extremity and the ratio lower/upper extremity was 5/1. We did not find, in contrast with other Authors, differences in height or in incidence of congenital malformations when compared to controls. The pain was the first common symptom at debut (90%) followed by swelling (50%) and fever (40%). Diagnosis was made 5.5 months after the first symptom and the delay was due to wrong diagnosis at debut in 3/4 of the patients. Laboratory tests showed anemia in about half of the patients and increased value of ESR (60%) and LDH (40%). Seventy-one of the patients were metastatic at presentation, none of these patients were still living after three years. At a median follow-up of 9 years 43% of the patients with localized disease, treated with adjuvant and neo-adjuvant chemotherapy remained continuously disease free, 53% developed metastatic disease and/or local recurrences and 2% had a second malignancy. In 24% of the patients metastases and/or local recurrences appeared three years after the beginning of treatment. Better prognosis was observed in female patients, without fever at diagnosis, with tumor localized at extremities and with normal value of hemoglobin, ERS and LDH. Regarding the type of treatment, better results were obtained by surgery of the primary tumor and by chemotherapy with four drugs (vincristine, cyclophosphamide, adriamycin dactinomycin) in comparison to radiotherapy of the primary tumor and chemotherapy with three drugs (vincristine, cyclophosphamide, adriamycin).

Effect of intra-arterial versus intravenous cisplatin in addition to systemic adriamycin and high-dose methotrexate on histologic tumor response of osteosarcoma of the extremities

In neoadjuvant treatment of osteosarcoma of the extremities intra-arterial (IA) instead of intravenous (IV) administration of cisplatinum (CDDP) has been advocated to improve local response and consequently increase the percentage of limb salvages and the cure rate. Since the major local advantages from the IA use of CDDP have been recently questioned, a comparative prospective study was performed at the Rizzoli Institute between July 1990 and September 1991. Preoperative chemotherapy consisted of two cycles of high-dose methotrexate (HDMTX), followed 6 days later by CDDP and adriamycin (ADM), HDMTX and ADM were delivered intravenously while CDDP was delivered according to previous randomization, either intra-arterially or intravenously. Of the 79 patients who entered the study 40 received CDDP IA and 39 CDDP IV. The percentage of clinical and radiological response of the tumor as well as the percentage of limb salvage procedures performed was the same in the two groups. However the rate of good histological response (tumor necrosis greater than 90%) was significantly higher in the group of patients who received IA CDDP than in the patients who received the drug intravenously (77.5% vs 46%: p less than 0.01). No differences in terms of local or systemic side effects were found in the two groups. A longer follow-up is necessary to establish if this improved good response rate achieved with IA CDDP will lead to an improved cure rate.(ABSTRACT TRUNCATED AT 250 WORDS)

The prognostic value of serum alkaline phosphatase in osteosarcoma of the limbs

The values for serum alkaline phosphatase were evaluated in 340 patients affected with osteosarcoma of the limbs. The percentage of patients with high values for the enzyme at the onset of disease was significantly higher in the 69 cases who presented with metastases at the time of diagnosis, as compared to the 271 cases in which the neoplasm still appeared to be localized (81% vs 62%: p less than 0.001). In this last group of patients, treated with neoadjuvant chemotherapy, an evident relationship between values for alkaline phosphatase and prognosis was demonstrated. The percentage of patients who developed metastases was in fact 22% in the group with normal serum values for the enzyme at the onset of the disease and 40% for the patients with high values of the same (P less than 0.001). These data confirm the prognostic value for serum alkaline phosphatase in osteosarcoma, which should be taken into consideration when planning chemotherapy and in classifying patients for randomized therapeutic studies.

Transcriptional induction of H2 (class I) antigens and beta 2 microglobulin by interferon-gamma in interferon-sensitive and interferon-resistant Friend leukemia cells

The effect of interferons (IFNs) type I (alpha/beta) and type II (gamma) on the stimulation of H2-Dd (class I) and beta 2 microglobulin genes transcription was analysed in IFN-sensitive (w.t.) and IFN-resistant Friend erythroleukemia cells (FLC). Type I IFN enhances the expression of H2-Dd and beta 2 microglobulin genes in w.t. FLC but does not modulate the expression of these genes in clones resistant to IFN-alpha/beta. IFN type II treatment of w.t. and IFN-alpha/beta resistant cell lines results in an increased expression of H2-Dd and beta 2 microglobulin genes, while being ineffective in the cell clone resistant to both types of IFNs. In this cell system the effect(s) of IFN type II is in part mediated by the induction of IFN-beta. The results reported in the present paper suggest that the IFN-gamma is able per se to increase the expression of H2-Dd and beta 2 microglobulin genes; since a reduced but clearly evident stimulation of the expression of these genes was observed in the FLC clone totally resistant to type I IFN.

Non-metastatic Ewing's sarcoma: results in 98 patients treated with neoadjuvant chemotherapy

From June 1983 to December 1987, 98 patients with non-metastatic Ewing's sarcoma of bone were treated by a protocol of neoadjuvant chemotherapy consisting of two months of preoperative chemotherapy with vincristine, adriamycin, and cyclophosphamide followed by local treatment and one year of chemotherapy aimed at preventing recurrence using the same drugs plus dactinomycin. Local treatment consisted of surgery in 39 cases (40%), radiation in 34 (34%), and both surgery and radiation in 25 (26%). After an average follow-up of five years, 51 patients (52%) had remained continuously disease-free (CDF), 46 had developed metastasis, of which 20 with local recurrence, and one had developed a radioinduced sarcoma. The site of the tumor (61% of patients with Ewing's sarcoma of the extremities were CDF vs. 35% with tumor of the pelvis) and the kind of local treatment (61% of patients who underwent surgery with or without radiation therapy were CDF vs. 35% of patients treated with radiation therapy alone) were important prognostic factors. These results are similar to those obtained in 59 patients treated from 1979 to 1982 (average follow-up, 10 years) using the same drugs administered according to adjuvant chemotherapy procedure as well as those reported in the only other large study on this subject in the literature (the multi-institution German study CESS-81). The authors conclude that even though neoadjuvant chemotherapy makes surgery possible and easier in Ewing's sarcoma, it does not significantly increase survival when compared to traditional adjuvant treatment.

Intracellular heme coordinately modulates globin chain synthesis, transferrin receptor number, and ferritin content in differentiating Friend erythroleukemia cells

The effect of succinylacetone (SA), a highly specific inhibitor of ALA-dehydratase and heme synthesis, on hemoglobin (Hb) production, transferrin receptor (TfR), and ferritin expression was analyzed in differentiating Friend leukemia cells (FLC). This compound exerted a pronounced inhibitory effect not only on heme and Hb synthesis, but also on all the remaining above-mentioned parameters. In particular, SA induced: (1) a reduction of the level of alpha-globin mRNA; (2) a decreased number of exposed TfR molecules, without modification of their affinity for the ligand; (3) a reduced level of TfR RNA, without significant change of TfR gene transcription rate; and (4) a lower ferritin content. The addition of exogenous hemin to differentiating FLC exerted opposite effects, and particularly induced an increase of both the number of TfRs and ferritin content. These findings suggest that in erythroid cells optimal heme synthesis is required to coordinately sustain globin chains synthesis and TfR/ferritin production; thus, the intracellular heme level may represent a key regulatory factor in the Hb synthesis pathway.

Posttranscriptional regulation of beta interferon expression in erythroid Friend cells treated with gamma interferon

Treatment of Friend erythroleukemia cells (FLC) with gamma interferon (IFN-gamma) in the presence of anti-IFN-beta antibodies reduces the effectiveness of the antiviral state and the induction of 2'-5'-oligoadenylate synthetase activity, indicating that the antiviral activity of IFN-gamma in FLC is in part mediated by the production of IFN-beta. Accordingly, IFN-gamma induces a less pronounced antiviral state in FLC resistant to IFN-alpha/beta than in wild-type cells. Moreover, while results of run-on assays indicate that both IFN-alpha and -beta genes are constitutively transcribed in these cells, FLC treatment with IFN-gamma induces only IFN-beta mRNA accumulation. These results indicate that posttranscriptional mechanisms are involved in the regulation of IFN-beta and -alpha expression by IFN-gamma. The low amounts of the induced IFN-beta synergize with IFN-gamma in mounting the potent antiviral effect.

Positive modulation of hemoglobin, heme, and transferrin receptor synthesis by murine interferon-alpha and -beta in differentiating Friend cells. Pivotal role of heme synthesis

Administration of highly purified preparations of murine interferon (IFN)-alpha 1, -alpha 4, -alpha 6, or -beta to Friend leukemia cells induced to differentiate by dimethyl sulfoxide leads to a 100% increase of benzidine-positive (B+) cells. Different efficiencies for the two IFN species have been observed; a 10-fold higher dose of IFN-alpha is needed for stimulation of hemoglobin production and inhibition of cell growth as compared with IFN-beta. Both species of IFN induce a substantial increase in heme, hemoglobin, and transferrin receptor levels. In vitro run-on transcription assays indicate that IFN-beta moderately stimulates transcription of the alpha-globin gene but not the transferrin receptor gene. It is postulated that IFN induces the enhancing effect on differentiation via a marked increase of heme synthesis and number of transferrin receptors, which in turn leads to an enhancement of globin chain synthesis. In this regard, the negative feedback reported in a variety of other cell types for the regulation of transferrin receptor expression by heme does not seem to be operative in maturing Friend erythroleukemia cells, which present evidence for a positive mechanism.

A full-length murine 2-5A synthetase cDNA transfected in NIH-3T3 cells impairs EMCV but not VSV replication

Treatment of cells with interferons (IFNs) induces resistance to virus infection. The 2'-5'oligo A (2-5A) synthetase/RNase L is one of the pathways leading to translation inhibition induced by IFN treatment. A murine cDNA encoding the 43-kDa 2-5A synthetase was cloned and sequenced. NIH-3T3 cell clones transfected with this cDNA expressed the enzymatic activity to various extents and exhibited resistance to encephalomyocarditis virus (EMCV) but not to vesicular stomatitis virus replication. The specific resistance to EMCV can be attributed to 2-5A synthetase.

[New clinico-therapeutic directions in upper airway pathology]

The main issues regarding the pathology of the primary airways in children, such as persistent rhinitis, recurrent disease of the pharynx and laryngitis, have been re-examined and updated on the basis of the latest findings regarding immunology and respiratory physiopathology as well as recent technological progress in the field of diagnosis. As far as rhinitis is concerned, recently demonstrations that nasal mucosa, like bronchial mucosa, responds to different kinds of stimuli with the same type of inflammation, have led to a new nosographic viewpoint: apart from classic allergic rhinitis, multifactorial forms are now recognised. They have been defined as nonallergic persistent rhinitis having a particular subgroup: nonallergic rhinitis with eosinophils. The fact that different factors contribute to bringing about the same inflammatory process is also confirmed by a personal study carried out on 132 asthmatic children with rhinitis: the results showed, in fact, that there are no differences regarding the nasal mucosa of allergic children (positive prick) and nonallergic children (negative prick). This observation therefore diminishes the importance of rhinoscopy in the etiologic diagnosis of rhinitis. As far as the obstructive syndrome caused by adenotonsillar hypertrophy is concerned, extremely polymorphic clinical pictures can be identified: from the slightest nocturnal hypoventilation to the apnea syndrome during sleep, even to the most severe forms with cardiocirculatory insufficiency. Personal data on 42 children helped to define both the anamnestic and objective findings necessary for making the diagnosis. It was therefore found that the most indicative and specific observations were those made either by the mothers (heavy breathing noises) or by the physician (inspiratory retractions) while the children were sleeping. Clinical data are therefore usually sufficient for making the diagnosis; however, in the first two years of life, a period in which surgical operations are usually delayed if possible, it is necessary to make an instrumental evaluation of the degree of hypoventilation. By means of radiological examination, pharyngoscopy and capnography, it is possible to record the degree of obstruction and therefore decide whether or not to delay surgery. Apart from the obstructive respiratory syndrome with hypoventilation, that requires surgery at all costs, other conditions were examined that can profit by adenoidectomy, such as affections of the middle ear, chronic sinusitis and craniofacial dysmorphisms. As far as laryngitis is concerned, the importance of radiology and endoscopy in rapidly diagnosing epiglottic laryngitis is reported. This in turn sometimes facilitates quick pharmacological treatment so as to avoid more invasive interventions, such as tracheostomy.

[Tuberculosis in children in the early 90's]

The natural history of tuberculosis was re-examined, and especially the relation between contagion and first infection on one side and, on the other, primary tuberculosis (in children) and secondary tuberculosis in adult. With regard to the primary tuberculosis, the different clinical pictures were taken into consideration and it was reported how symptoms change as years go by (see miliary tuberculosis). As for the diagnostic aspect the importance of a quantitative interpretation of Mantoux reaction, was emphasized. In the final judgement, all factors that may change the results can therefore by considered: from the intercurrent viral infection to the patient's age, to the spreading of atypical mycobacteria in that area. The screening performed with the multi-injections technique is necessary to control the diffusion of the infection in the general population. In Italy, 1-2% of children aged 6 to 14 years old, are skin positive but the percentage varies widely in the different areas. However, it was higher than that observed in other European countries and far from the 1% incidence for 14 year olds, as hoped by the World Health Organization. After re-examining the characteristics of the four most important anti-tubercular drugs with particular attention to possible hepatotoxic effects of the isoniazid-rifampicin association, the authors analyses new therapeutic strategies, especially the one that tends to shorten treatment periods. This approach is effective in adults but has not yet been definitively confirmed in children. The surgical approach is more standardized in superficial adenitis where extirpation is indicated in atypical mycobacteria infections rather than in those due to Koch's bacillus. As far as indications of chemoprophylaxis are concerned it would seem that an international arrangement has now been reached that on the whole extends the indications to this type of treatment. The only uncertainty is whether adults, with intradermal reactions to tuberculin should undergo chemoprophylaxis if the time of contagion is unknown and the subject does not show any particular risk factors. On the grounds of data from literature, the results of vaccination are contrasting. Many factors could be responsible for this, especially the use, till a few years ago, of a non-standardized vaccine. However, vaccination remains an efficient method in populations at risk, listed in Italian law too. Nevertheless, according to the law, the subjects who would most benefit by vaccination are excluded (children under the age of 5 years and over the age of 15 years). However vaccination is getting less important in the general population.(ABSTRACT TRUNCATED AT 400 WORDS)

Variation in the relative synthesis of some proteins in mammalian cells exposed to hypertonic medium

Exposure of a number of quiescent murine and human cell lines to low-graded doses of cycloheximide (CXM) results in a pattern of protein synthesis consisting of enhanced and induced species. This pattern is reminiscent of but not identical to that observed after several stress treatments [V. Sorrentino et al. (1985) J. Cell. Physiol. 125, 313]. A pattern identical to that seen after exposure to CXM is synthesized when cells are exposed to an hypertonic growth medium resulting in a full and reversible block of the initiation of polypeptide chain. This suggests that this kind of response is triggered by a reduction of overall protein synthesis rather than by a slow-down of the elongation step. Analysis of the synthesis of histones and ribosomal proteins during these two nonphysiological treatments (CXM or high salt) shows that these classes of proteins are neither stimulated nor preferentially retained. In contrast, greatly enhanced levels of steady-state histone mRNAs have been observed which have been translated in a reticulocyte lysate system, but are not apparently translated in vivo.

Inhibition of protein synthesis by diphtheria toxin induces a peculiar pattern of synthesized protein species

The irreversible inhibition of overall protein synthesis induced by diphtheria toxin in mammalian cells is accompanied by a peculiar pattern of synthesized protein species during the early stages of cell intoxication. This pattern closely resembles patterns of synthesized protein species observed in cells treated with reversible inhibitors of protein synthesis acting at different levels. Synthesized proteins are in the Mr range of 70-100 and 20-40 kDa. A 50-kDa protein, the most represented species, exhibits a peptide map identical to that of the 50-kDa species observed in cells treated with cycloheximide and hypertonic medium. The synthesis of these proteins is apparently regulated at both transcriptional and translational levels.

[Circadian variations of bronchoconstriction in asthmatic children]

In order to determine the magnitude of circadian variations in bronchoconstriction, we examined modifications of the spirometry observed during the 24-hr in a group of asthmatic (31 males, mean age = 8 years, 6 months). Particular attention was paid to the forced expiratory volume in 1 sec. (FEV1) and the forced vital capacity (FVC). We were thus able to compare in single patients 43 spirometry pairs between morning (between 8 and 10 am) and early afternoon (between 1 and 4 pm), 46 pairs between morning and evening (between 6 and 10 pm) and 54 between 2 consecutive mornings. The results of this study, substantially similar for the FEV1 and the FVC, show that the mean values obtained at different hours during the day and in two consecutive mornings were almost superimposable. On the other hand, the mean values and the standard deviations of the differences between two determinations in single patients are high. The percentage of patients who present significant modifications (greater than 10%) of FEV1 or of FVC at different hours of the day is also quite high. Moreover these variations seem directly related to the baseline spirometric value. Although the literature frequently outlines the existence of a circadian rhythm in the modifications or airways patency (maximum bronchoconstriction in the morning and minimum in the evening), in the asthmatic, however, the fast variations in the bronchial tone can be such as to mask this cyclic rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)