In the facultative sulphate/nitrate reducer Desulfovibrio desulfuricans ATCC 27774, the nine-haem cytochrome c is part of a membrane-bound redox complex mainly expressed in sulphate-grown cells

The bacterium Desulfovibrio desulfuricans ATCC 27774 belongs to the group of sulphate reducers also capable of utilising nitrate as its terminal electron acceptor for anaerobic growth. One of the complex multihaem proteins found in nitrate- or sulphate-grown cells of Desulfovibrio desulfuricans ATCC 27774 is the nine-haem cytochrome c. The present work shows that the gene encoding for Desulfovibrio desulfuricans ATCC 27774 nine-haem cytochrome c is part of an operon formed by the gene cluster 9hcA-D. Besides 9hcA, the gene encoding for the nine-haem cytochrome c, genes 9hcB to D encode for a protein containing four [4Fe-4S](2+/1+) centres, for a dihaem transmembrane cytochrome b and for an unknown hydrophobic protein, respectively. The four proteins have a predicted topology that is in accordance with the formation of a membrane-bound redox complex. Furthermore, the transcriptional studies show that not only the expression of the 9HcA-D complex is dependent on the growth phase, but also is markedly increased in sulphate-grown cells.

Impact of multiple insertions of two retroelements, ZAM and Idefix at an euchromatic locus

Transposable elements represent a large fraction of eukaryotic genomes and they are thought to play an important role in chromatin structure. ZAM and Idefix are two LTR-retrotransposons from Drosophila melanogaster very similar in structure to vertebrate retroviruses. In all the strains where their distribution has been studied, ZAM appears to be present exclusively in the intercalary heterochromatin while Idefix copies are mainly found in the centromeric heterochromatin with very few copies in euchromatin. Their distribution varies in a specific strain called RevI in which the mobilization of ZAM and Idefix is highly induced. In this strain, 15 copies of ZAM and 30 copies of Idefix are found on the chromosomal arms in addition to their usual distribution. Amongst the loci where new copies are detected, a hotspot for their insertion has been detected at the white locus where up to four elements occurred within a 3-kb fragment at the 5' end of this gene. This property of ZAM and Idefix to accumulate at a defined site provides an interesting paradigm to bring insight into the effect exerted by multiple insertions of transposable elements at an euchromatic locus.

Silica and its antagonistic effects on transforming growth factor-beta in lung fibroblast extracellular matrix production

BACKGROUND

Silicosis, a pneumoconiosis marked by interstitial pulmonary fibrosis, is caused by inhalation of free crystalline silica particles. When silica particles are injected into the lower lung, they are translocated across the epithelium into the interstitial space, where macrophage-derived growth factors affect lung fibroblast proliferation and collagen deposition. We hypothesized that silica may act directly on pulmonary fibroblasts modifying extracellular matrix (ECM) synthesis and that the effects of silica may be mediated by transforming growth factor-beta (TGFbeta) overproduction.

METHODS

To test this hypothesis, we studied a human lung fibroblast cell line (WI-1003) exposed to silica in vitro. We investigated cell morphology by electron microscopic procedure, cell growth, collagen production, and glycosaminoglycans (GAG) composition by radiolabeled precursors. Cytokine and growth factor synthesis were evaluated by specific enzyme-linked immunoadsorbent assay kits and Northern blotting analysis.

RESULTS

Pulmonary fibroblasts internalized silica particles without detectable cell damage. Silica directly stimulated collagen synthesis and decreased the amount of 3H-glucosamine-labeled GAG. Silica-treated fibroblasts secreted less TGFbeta than untreated controls, antagonized the stimulatory effect of TGFbeta on ECM synthesis, and reversed TGFbeta-induced inhibition of cell proliferation. Northern blotting analysis showed increased interleukin-1alpha (IL-1alpha) mRNA after silica treatment. IL-1alpha had no influence on collagen synthesis but increased the number of WI-1003 fibroblasts.

CONCLUSIONS

These results support our hypothesis that lung fibroblasts are direct silica targets. However, contradicting our hypothesis, silica antagonized TGFbeta activities through a TGFbeta downregulation and an IL-1alpha upregulation. The complex pattern of TGFbeta and IL-1alpha regulation in pulmonary fibroblasts is imbalanced by silica exposure and might play a key role in silica-mediated pulmonary fibrosis.

Interleukin secretion, proteoglycan and procollagen alpha(1)(I) gene expression in Crouzon fibroblasts treated with basic fibroblast growth factor

The present study provides the first evidence that fibroblasts obtained from patients affected by Crouzon syndrome, a rare craniosynostosis, despite mutations in the high-affinity bFGF receptor retain their capacity to respond to bFGF. The growth factor reduces IL-1 secretion, downregulates biglycan and procollagen alpha(1)(I), and increases betaglycan expression. Since betaglycan is a co-receptor for bFGF signalling, an alternative signal transduction pathway is suggested in Crouzon fibroblasts, to explain the documented changes in ECM macromolecule production.

Expression of a Desulfovibrio tetraheme cytochrome c in Escherichia coli

A tetraheme cytochrome c was successfully overexpressed for the first time in Escherichia coli. Desulfovibrio desulfuricans ATCC 27774 tetraheme cytochrome c(3) was expressed in aerobically grown Escherichia coli cotransformed with Escherichia coli ccm gene cluster (Arslan et al. (1998) Bioch. Biophys. Res. Commun. 251, 744-747). The analysis of the produced cytochrome showed that the signal peptide was correctly cleaved, the four heme groups were inserted and the electronic structure around the heme irons was conserved, i.e., the recombinant tetraheme cytochrome was identical to that isolated from the native source. Contradicting previous results which indicated that Escherichia coli was only capable of producing apocytochrome c(3) (Pollock et al. (1989) J. Gen. Microbiol. 135, 2319-2328), the present work proves unequivocally that the holoform can also be obtained.

TGFbeta isoforms and decorin gene expression are modified in fibroblasts obtained from non-syndromic cleft lip and palate subjects

Interaction between extracellular matrix (ECM) and cytokines is thought to be crucial for palatal development. The localization of transforming growth factors (TGFalpha and TGFbeta isoforms) in craniofacial tissues suggests that they carry out multiple functions during development. In the present report, we studied TGFalpha, TGFbeta1, and TGFbeta3 expressions and their effects on ECM macromolecule production of normal and cleft palatal fibroblasts in vitro, to investigate the mechanisms by which the phenotypic modulation of fibroblasts occurs during the cleft palate process. The results indicated that, while TGFalpha mRNA was not evidenced in CLP or normal fibroblasts, a reduced TGFbeta1 hybridization signal was detected in CLP fibroblasts. In addition, these secreted more active TGFbeta3 than TGFbeta1, as evaluated in a biological assay. The CLP phenotype, which differed from the normal one because of its higher PG decorin expression and greater production of GAG and collagen, was further modified by the addition of growth factors. In fact, in CLP fibroblasts, TGFalpha and TGFbeta1 down-regulated PG decorin transcript, TGFbeta1 increased collagen and GAG in both cellular and extracellular compartments, and TGFbeta3 promoted secretory processes of cells. In conclusion, the data represent the first report in a human model in vitro that TGFbeta1 and beta3 are differently expressed and are correlated to the CLP phenotype. Thus, strength is given to the hypothesis that TGFbeta isoforms are the potential inducers of phenotypic expression in palatal fibroblasts during development and that an autocrine growth factor production mechanism may be responsible for the phenotypic modifications.

A regulatory role of fibroblast growth factor in the expression of decorin, biglycan, betaglycan and syndecan in osteoblasts from patients with Crouzon's syndrome

Bone development is controlled by the autocrine and/or paracrine effects of regulatory molecules. We previously showed that the phenotype of fibroblasts obtained from patients affected by Crouzon's syndrome, an autosomal dominant disease characterized by pathological skull bone development, differed from that of normal cells and was regulated by interleukin treatments. The changes in the relative concentrations of extracellular macromolecules (glycosaminoglycans-GAG, collagen and fibronectin) were associated with abnormal interleukin secretion that affected the microenvironment where the osteogenic processes take place. Mutations in human fibroblast growth factor receptors are now thought to be involved in Crouzon's syndrome. Since coactivation of interleukins and basic fibroblast growth factor (bFGF) is probably implicated in morphogenetic and osteogenic processes and heparan sulphate proteoglycans have a critical role in regulating bFGF activity, the phenotypes of normal and Crouzon osteoblasts were studied and the effects of bFGF on the expression of bFGF, procollagen alpha1 (I), and proteoglycan (PG) genes for biglycan, decorin, betaglycan and syndecan analyzed. Specific human cDNA probes were used to screen the relative levels of mRNA by Northern analysis. Spontaneous or bFGF-modulated release of interleukins was also assayed. The bFGF gene transcript was detected only in Crouzon osteoblasts. We showed for the first time that Crouzon osteoblasts, despite a mutation in the FGF receptor, still responded to exogenous bFGE In fact, the growth factor induced changes in the GAG profile and in the levels of mRNA coding for PG and procollagen alpha1 (I) and down-regulated heparan sulfate GAG chains. ELISA showed that bFGF-induced interleukin secretion differed in normal and Crouzon osteoblasts. The observed differences in PG core protein, procollagen alpha1 (I) and bFGF could be associated with the Crouzon bone phenotype and also should provide further understanding on the molecular basis of the diseased state of bone.

Mobilization of two retroelements, ZAM and Idefix, in a novel unstable line of Drosophila melanogaster

We describe a novel transposition system in a line of Drosophila melanogaster called RevI in which two retroelements are mobilized. These elements are the retroelement ZAM, recently described in the literature, and a novel element designated Idefix. Like ZAM, Idefix displays the structural features of a vertebrate retrovirus. Its three open reading frames encode predicted products resembling the products of the gag, pol, and env genes of retroviruses. In situ hybridization and Southern analyses performed on the RevI genome revealed the presence of some 20 copies of ZAM and Idefix, whereas ZAM is absent and Idefix is present in only four copies on the chromosomal arms of the original parental line. From RevI, a series of mutations affecting eye coloration has been recovered. The genetic and molecular analyses of these mutations have shown that most of them affected the white locus through three rounds of mutational events. The first mutational event was previously shown to be caused by a ZAM insertion 3 kb upstream of the transcription start site of white. It confers a red-brick phenotype to the orange eye coloration of the parental line. The second event results from the insertion of an Idefix copy 1.7 kb upstream of the transcription start site of the white gene, which modifies the red-brick phenotype to orange. This second mutational event was recovered as a recurrent specific mutation in 11 independent individuals. The third event results from an additional Idefix located 1.7 kb upstream of white that is responsible for the full reversion of the orange phenotype to red-brick. The fact that such mutations due to recurrent appearances of both ZAM and Idefix at the white locus result in such a variety of phenotypes brings to light a new molecular system in which the interference of mobile elements with the correct expression of the host gene can be tested.

DNA fingerprinting analysis by a PCR based method for monitoring the genotoxic effects of heavy metals pollution

Environmental pollutants can have deleterious effects on living organisms. At high concentrations, or at high activities, they can cause acute toxicity damaging cells, tissues and organs. Chronic toxification, on the other hand, can also cause serious damage from bio-accumulation. Plants, as biological indicators, can measure both the actual and the potential effects of pollutants, when they are used to measure effects of heavy metals. We have applied a system of "molecular fingerprinting" based on PCR (RAPD: Random Amplified Polymorphic DNA) to the evaluation of the genotoxic effects of heavy metals in order to estimate the environmental risk connected with their potential mutagenic effects in the model plant Arabidopsis thaliana, ecotype Columbia. Genomic DNA was utilised for RAPD analysis using random primers (10-mers). DNA from plants exposed to heavy metals solution displayed polymorphic bands which were not detectable in DNA of unexposed plants. The enhanced formation of RAPD polymorphisms was also observed in DNA of plant exposed in situ to an industrial pollution source. The comparison between "unexposed" and "exposed" genomes show that RAPD analysis can be used to evaluate how the environmental pollutants modify the structure of DNA in living organisms.

Glycosaminoglycan profile in macrophages exposed to Candida albicans and interleukins

Glycosaminoglycans (GAG), are extracellular matrix macromolecules that affect the phagocytic properties of macrophages. In order to assess whether the interaction between macrophages and Candida albicans (iCa) provokes changes in the phenotype, we analyzed the GAG profiles in two macrophage lines, ANA-1 (from murine bone-marrow) and BV-2 (from murine brain). We also investigated GAG modulation by interleukin-1alpha (IL-1alpha) and interleukin-6 (IL-6). During iCa treatment and even after the addition of ILs, ANA-1 accumulated less total GAG compared to controls. IL-1 treatment, combined with iCa exposure, induced a decrease in heparan sulfate and chondroitin sulfate chains, and an increase in the hyaluronic acid percentage. IL-6 treatment, with or without iCa, decreased the hyaluronic acid/sulfated GAG ratio. The GAG pattern in BV-2 appears to be different to ANA-1 and iCa exposure does not induce any difference in total GAG. The inhibitory effect induced by ILs on GAG synthesis is less than that observed in ANA-1 and the GAG elution profile is modulated to a lesser extent by treatment with ILs and/or iCa compared to the ANA-1. We suggest that the observed changes in the expression of the individual GAG classes may be responsible for the macrophage functional heterogeneity.

Agonist and antagonist actions of antipsychotic agents at 5-HT1A receptors: a [35S]GTPgammaS binding study

Recombinant human (h) 5-HT1A receptor-mediated G-protein activation was characterised in membranes of transfected Chinese hamster ovary (CHO) cells by use of guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]GTPgammaS binding). The potency and efficacy of 21 5-HT receptor agonists and antagonists was determined. The agonists, 5-CT (carboxamidotryptamine) and flesinoxan displayed high affinity (subnanomolar Ki values) and high efficacy (Emax > 90%, relative to 5-HT = 100%). In contrast, ipsapirone, zalospirone and buspirone displayed partial agonist activity. EC50s for agonist stimulation of [35S]GTPgammaS binding correlated well with Ki values from competition binding (r = +0.99). Among the compounds tested for antagonist activity, methiothepin and (+)butaclamol exhibited 'inverse agonist' behaviour, inhibiting basal [35S]GTPgammaS binding. The actions of 17 antipsychotic agents were investigated. Clozapine and several putatively 'atypical' antipsychotic agents, including ziprasidone, quetiapine and tiospirone, exhibited partial agonist activity and marked affinity at h5-HT1A receptors, similar to their affinity at hD2 dopamine receptors. In contrast, risperidone and sertindole displayed low affinity at h5-HT1A receptors and behaved as 'neutral' antagonists, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Likewise the 'typical' neuroleptics, haloperidol, pimozide, raclopride and chlorpromazine exhibited relatively low affinity and 'neutral' antagonist activity at h5-HT1A receptors with Ki values which correlated with their respective Kb values. The present data show that (i) [35S]GTPgammaS binding is an effective method to evaluate the efficacy and potency of agonists and antagonists at recombinant human 5-HT1A receptors. (ii) Like clozapine, several putatively 'atypical' antipsychotic drugs display balanced serotonin h5-HT1A/dopamine hD2 receptor affinity and partial agonist activity at h5-HT1A receptors. (iii) Several 'typical' and some putatively 'atypical' antipsychotic agents displayed antagonist properties at h5-HT1A sites with generally much lower affinity than at hD2 dopamine receptors. It is suggested that agonist activity at 5-HT1A receptors may be of utility for certain antipsychotic agents.

Agonist activity of antimigraine drugs at recombinant human 5-HT1A receptors: potential implications for prophylactic and acute therapy

The actions of several serotonergic ligands in use or under development for the treatment of migraine headaches were examined at recombinant human 5-HT1A receptors stably expressed in Chinese Hamster Ovary cells. Affinities (K(i)s) at this site were determined in competition binding experiments with [3H]-8-OH-DPAT ([3H](+/-)8-hydroxy-N,N-dipropylaminotetralin), whilst agonist efficacy was measured by stimulation of [35S]-GTP gamma S (guanylyl-5'-[gamma[35S]thio]-triphosphate) binding. Of the prophylactic antimigraine drugs tested, methysergide and lisuride behaved as efficacious agonists (Emax > or = 90% relative to 5-HT) whereas pitozifen and (-)propranolol acted as a partial agonist (60%) and an antagonist, respectively. This suggests that there is no correlation between agonism at 5-HT1A receptors and prophylactic antimigraine action. In contrast, serotonin, dihydroergotamine, sumatriptan, naratriptan and alniditan, which are effective in acute interruption of migraine attacks, each displayed high efficacy (Emax = 100, 100, 92.6, 79.3, 79.1% respectively) and marked affinity (Ki = 18.7, 0.6, 127, 26.4 and 3.0 nM respectively) at 5-HT1A receptors. EC50 values for agonist stimulation of [35S]-GTP gamma S binding correlated with respective Ki values at 5-HT1A receptors (r = 0.93) and the stimulation of [35S]-GTP gamma S binding by these compounds was antagonised by the selective 5-HT1A antagonist WAY 100,635 (N-{2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl}-N-(2-pyridinyl) cyclo-hexanecarboxamide; 100 nM). These data suggest that agonism at 5-HT1A receptors may be involved in some actions of drugs used in acute antimigraine therapy. In comparison with the above compounds, novel ligands targeted at 5-HT1B/1D receptors, such as GR125,743 (N-[4-methoxy-3-(4-methyl-piperazin-1-yl)phenyl] -3-methyl-4-(4-pyridyl)benzamide) and GR 127,935 (N-[4-methoxy-3-(4-methylpiperazin-1-yl)-phenyl]-2'-methyl-4'-(5-m ethyl-1, 2,4-oxadiazol-3-yl)-biphenyl-4-carboxamide), only weakly activated [35S]-GTP gamma S binding (32.4 and 32.1% efficacy) and displayed moderate affinity at 5-HT1A receptors (Kis 53.1 and 49.8 nM) suggesting that they constitute useful tools to differentiate 5-HT1A and 5-HT1B/1D receptor-mediated actions. In conclusion, the present data indicates that several antimigraine agents exhibit marked 5-HT1A receptor activity and that although this is unlikely to be important for prophylactic action it may be relevant to the ancilliary properties of drugs used for acute migraine treatment.

Agonist and inverse agonist efficacy at human recombinant serotonin 5-HT1A receptors as a function of receptor:G-protein stoichiometry

Membrane preparations were made from Chinese Hamster Ovary (CHO) cells expressing 1.6 and 4.2 pmol/mg of recombinant human 5-HT1A receptors, as determined by saturation binding with the selective antagonist, [3H]-S 15535 ([3H]-4-(benzodioxan-5-yl)]-(indan-2-yl)piperazine). There was no change in the number of G-proteins activated by the full agonist, serotonin (5-HT; approximately 1.1 pmol/mg in each preparation, measured by [35S]-GTP gamma S saturation binding), therefore increasing the receptor:G-protein ratio from approximately 1.4:1 (RGlow) to approximately 4:1 (RGhigh). Agonist efficacy was measured by stimulation of [35S]-GTP gamma S binding. The serotonergic agonist, eltoprazine, behaved as a partial agonist (Emax = 52.7%) at RGlow membranes but virtually as a full agonist (Emax = 93.2%) at RGhigh membranes, relative to 5-HT (= 100%). The latter exhibited a two-fold shift to the left in its concentration-response curve in RGhigh compared to RGlow membranes (P < 0.01). WAY 100,635 (N-¿2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl¿-N-(2-pyridinyl) -cyclo-hexane-carboxamide), did not alter [35S]-GTP gamma S binding from basal levels in either membrane preparation. In contrast, spiperone displayed inverse agonist activity, decreasing [35S]-GTP gamma S binding from basal levels by 17% in RGlow membranes but by 28% in RGhigh membranes. These data indicate that an increased receptor:G-protein ratio (i) augments the potency of full agonists, (ii) increases the efficacy of partial agonists and (iii) increases the negative efficacy of inverse agonists at recombinant human 5-HT1A receptors. Furthermore, these data suggest that spiperone induces, or stabilises, a G-protein-coupled, but inactive conformation of the receptor.

[Diagnosis and treatment of gastrointestinal carcinoid. Report of a clinical case with duodenal site]

Carcinoid tumors are among the most frequently neuroendocrine neoplasms of the gastrointestinal tract. They occur more commonly as benign diseases but malignant ones can also be found. The peak age incidence varies with the location of the tumor, with appendiceal tumors being diagnosed at an overage of 36 years, whereas non appendiceal tumors are found typically in the fifth sixth decades of life. There is no sex predilection of the tumors. Most carcinoid tumors are found within the appendix (40-50%) or small intestine (25%). Less common sites include the rectum (15%), main bronchus (10%), duodenum (3-8%) and stomach (2%). Most carcinoid tumors are found incidentally at operation and cause no symptoms. If symptoms do occur, they can be either non specific include intermittent crampy abdominal pain, vomiting and distension caused by intestinal obstruction. The prognosis depends on the site of the tumor and its size. Most carcinoid tumors (75%) are less than 1 cm in size and only 5% are greater than 2 cm. The incidence of metastatic disease is related directly to the size of the tumor at all locations. Carcinoid tumor with size less than 1 cm give linfonodal metastasis only in 3-5%; the other with size over 2 cm give metastasis in the 70-75% of the cases. The 5-years survival for all carcinoid tumors are approximately 85%. Five years rate is higher (> 80%) in carcinoid tumors of appendix and rectum than in gastroduodenal, ileal and colonic neoplasm (< 60%). In this paper the authors report a case of malignant carcinoid of the duodenum.

Inhibition of the constitutive activity of human 5-HT1A receptors by the inverse agonist, spiperone but not the neutral antagonist, WAY 100,635

At recombinant human 5-hydroxytryptamine (5-HT)5-HT1A receptors expressed in Chinese hamster ovary cells (CHO-5-HT1A), 5-carboxamidotryptamine (5-CT), acted as a full agonist (relative to 5-HT = 100%) for stimulation of receptor-mediated [35S]-GTP gamma S (guanylyl 5'-[gamma-thio]-tryphosphate) binding. In contrast, spiperone inhibited basal [35S]-GTP gamma S binding by 30.2% (IC50 = 55.5 nM) in CHO-5-HT1A membranes but not in control untransfected membranes. The antagonist, N-[2-[4-(2-methoxyphenyl) -1-piperazinyl]ethyl]-N-(2-pyridinyl)-cyclohexane-carboxamide (WAY 100,635), blocked both 5-CT-induced stimulation and spiperone-induced inhibition of [35S]-GTP gamma S binding without itself modifying [35S]-GTP gamma S binding. It is concluded that, in this heterologous expression system, 5-HT1A receptors display 'constitutive' activation of G-proteins and that spiperone displays inverse agonist activity whereas WAY 100,635 acts as a 'neutral' antagonist at this site.

Prognostic significance of metabolic changes detected by proton magnetic resonance spectroscopy in ischaemic stroke

Proton magnetic resonance spectroscopy has proved to be useful for monitoring a number of metabolites in cerebral infarction. Combined magnetic resonance imaging and spectroscopy investigations were carried out in 14 patients with a recent ischaemic stroke (< 1 week); follow-up examinations were performed from day 28 to day 252 after stroke. The aim of this study was to assess the correlation between the changes of N-acetyl-aspartate, choline, creatine-phosphocreatine, lactate and clinical evolution measured by the Scandinavian Neurological Scale (SNS). Initially the lactate magnetic resonance signal was present in all patients and the other metabolite contents were significantly reduced (P < 0.001; unpaired t-test) as compared with those on the contralateral side. Spearman's rank correlation test showed a positive correlation between the initial reduction of N-acetyl-aspartate content and the SNS (P < 0.05), and between the final N-acetyl-aspartate content and the SNS (P < 0.001). Our results suggest that serial examination in stroke patients may provide further prognostic information and encourage controlled clinical studies.

99Tcm-HMPAO SPET and 1H-MRS (proton magnetic resonance spectroscopy) in patients with ischaemic cerebral infarction

Brain 99Tcm-HMPAO single photon emission tomography (SPET) and 1H-MRS (proton magnetic resonance spectroscopy) were used to determine correlations between alterations in regional cerebral blood flow (rCBF) and changes in neuronal metabolites in 21 patients (28 examinations) with ischaemic cerebral infarction examined in different phases. rCBF was determined semi-quantitatively using Lassen's linearization algorithm. SPET provided evidence of the hypoperfused site of necrosis within a few hours after the acute event and alterations in rCBF were detected in both the infarcted and diaschistic areas at all stages. 1H-MRS was used to monitor the concentration of the following metabolites: N-acetyl-aspartate (NAA), creatine and phosphocreatine (CR + PCr), compounds containing choline (Cho) and lactate (Lac). A significant correlation was found between reduction in rCBF and a fall in NAA and Cr + PCr in both the acute and chronic phases, but not during "luxury perfusion' in the subacute phase. The presence of LAC in the infarcted area up to 9 months post-ictus was totally unexpected. Simultaneous SPET and 1H-MRS thus provides additional information regarding the physiopathogenesis of cerebral ictus by clarifying the relation between alterations in rCBF and biochemical neuronal changes. We believe that NAA and Cr + PCr concentrations are the best expression of agreement between flow and metabolism in infarcted areas, particularly with regard to hypoperfused areas not clearly detectable by magnetic resonance imaging in the early post-ictus stage.

HLA and ethnic associations among systemic sclerosis patients with anticentromere antibodies

SSc with ACAs is characterized by limited cutaneous involvement and, in most patients, a mild protracted course. We have studied 104 SSc patients, 47 with ACAs and 57 who were negative for both ACAs and anti-topo I antibodies, for HLA-DR and -DQ associations using DNA typing techniques. Normal controls consisted of 181 healthy individuals. A significant association was observed in the ACA-positive patients with DQB1-0501 (p = 0.001, RR 2.6). There was also a significant decrease in the frequency of DQB1-0201 (p = 0.01, RR 0.33). In addition, the ACA-positive SSc patients were significantly different ethnically from both the other SSc patients and the normal controls (p = 0.004). When patients were stratified according to their ethnic origin and the analysis of HLA associations was repeated, the HLA associations persisted. These results strongly suggest that the development of SSc with ACAs is associated with particular DQB1 alleles, and also that ethnic origin plays a role in disease susceptibility.

Proton magnetic resonance spectroscopy in patients with ischemic stroke

Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive technique which has proved to be useful for monitoring various brain metabolites (N-acetyl-aspartate, choline, creatine-phosphocreatine, lactate). A total of 18 patients underwent a combined magnetic resonance imaging (MRI)/1H-MRS protocol in order to evaluate the distribution of the metabolites in the various stages of cerebral ischemia. Our results show a marked decrease of N-acetyl-aspartate and a large content of Lactate during the early phases, and a decrease in N-acetyl-aspartate, choline and creatine-phosphocreatine (Cr-PCr) during the chronic phase.

[Retroperitoneal ganglioneuroma. A case report and review of the literature]

Ganglioneuromas are typically of slow growth and benign evolution and may remain clinically silent for a considerable time if favourably situated. Many large examples are discovered incidentally on X-ray examination, routine abdominal palpation or at necropsy. Ganglioneuromas are often encountered in childhood and are found more frequently in the posterior mediastinum than in any other single situation; other sites are the lumbar and pelvic retroperitoneal tissues, the gastrointestinal tract and the mesentery. Diffuse alimentary tract ganglioneuromatosis has been described as port of the multiple endocrine neoplasia syndrome (MEN) type II-B. Sometimes ganglioneuromas are found in the von Recklinghausen Syndrome. The authors report in this paper a rare case of a retropancreatic ganglioneuromas.

Therapy for severe interstitial lung disease in systemic sclerosis. A retrospective study

OBJECTIVE

This retrospective observational study attempted to determine whether any of the therapies used in the management of systemic sclerosis (SSc) patients held potential benefit for patients with interstitial lung disease.

METHODS

All patients with SSc who had a pulmonary function test (PFT) showing a forced vital capacity (FVC) of < 70% predicted and an additional PFT at least 4 months later were grouped according to the treatment they received. Changes in pulmonary function were analyzed by the mean percent predicted FVC from the initial and the final test, and by the rate of percent change in FVC (ml/year) in the first 2 years after therapy. Bronchoalveolar lavage was performed in a subset of these patients.

RESULTS

Of 363 SSc patients who had an FVC < 70% predicted, 122 had a second PFT and fulfilled the criteria for one of the following drug groups: high-dose prednisone (n = 21), immunosuppressive other than cyclophosphamide (CYC) (n = 16), CYC (n = 14), D-penicillamine (n = 37), or no drug (n = 34). In both analyses, the CYC-treated group showed significantly more improvement in FVC than did the other groups. Patients with early disease had the greatest likelihood of responding to any drug.

CONCLUSION

This retrospective study shows that patients treated with CYC had a significant improvement in FVC over time. Prospective controlled studies of CYC treatment in early disease are necessary to determine if it can significantly alter the natural history of interstitial lung disease.

Severe restrictive lung disease in systemic sclerosis

OBJECTIVE

We sought to identify risk factors for developing severe restrictive lung disease and to determine the time of onset and rate of progression in patients with systemic sclerosis (SSc).

METHODS

Using the University of Pittsburgh Scleroderma Databank, we grouped patients according to their lowest forced vital capacity (FVC) value: > 75% predicted, 50-75% predicted, and < 50% predicted. In patients with severe restrictive disease, we examined serial pulmonary function test (PFT) results to determine the rate of loss of lung volume over time.

RESULTS

Of 890 SSc patients, 60% (n = 531) never had an FVC < or = 75% predicted; 27% (n = 243) had moderate restrictive disease, with an FVC value of 50-75% predicted; and only 13% (n = 116) of the patients had severe restrictive disease, with FVC < or = 50% predicted. Black race, male sex, early disease, and primary cardiac involvement due to SSc were the features most frequently associated with severe restrictive lung disease (by multiple logistic regression). Fifty-five patients with severe restrictive lung disease had their first of at least 2 PFTs during the first 5 years after onset of any SSc (not pulmonary) symptoms. In 30 patients, the FVC declined by 32% per year in the first 2 years of illness, in 16 patients the annual loss was 12% in years 2-4 after disease onset, and in 9 patients annual loss was 3% during years 4-6 of disease (P < 0.005 by 1-way analysis of variance).

CONCLUSION

In SSc patients, black men with early disease who have cardiac involvement are the most likely to have factors associated with the development of severe restrictive lung disease (which is increasingly becoming a major cause of death). Disease subtype (diffuse versus limited cutaneous) and serum anti-topoisomerase I antibody do not differentiate between moderate and severe restrictive disease. Careful monitoring of pulmonary function early in the disease, when the greatest loss of lung function occurs, may help identify patients likely to respond to new therapy.

Severe systemic sclerosis with anti-topoisomerase I antibodies is associated with an HLA-DRw11 allele

SSc is an autoimmune connective tissue disease in which strong HLA associations have not been described. Anti-topo I antibodies are recognized, in general, in SSc patients with diffuse cutaneous involvement, whereas anti-ACAs are found in individuals with limited cutaneous involvement. We studied 95 Caucasian SSc patients, 44 with anti-topo I antibodies and 51 with neither anti-topo I nor ACA, for HLA-DR associations by using DNA typing techniques. We analyzed 181 normal Caucasian individuals in the same fashion. A significant association was observed in the anti-topo-I-positive patients with DRw11 (p = 1.7 x 10(-6), RR 4.2). The distribution of DRw11 alleles in these patients was significantly different from that observed in controls and could be accounted for by an increase in the frequency of the DRB1*1104 allele (p = 1.2 x 10(-9), RR 9.5). The DRw11 alleles were also associated with SSc with more tendon friction rubs (p = 0.006), which is a marker of more severe disease. In addition, a strong association was observed with anti-topo I antibodies and a particular sequence (aa 71-77) of the DQB1 chain (p = 0.02, RR 2.2). HLA associations in the case of SSc patients with anti-topo I antibodies are complex and involve at least two genes: HLA-DRw11, which appears to play a major role in determining the severity of the disease, and a DQ sequence, which associates with the development of the anti-topo I antibodies.

Cerebral ischemia: magnetic resonance angiography and transcranial Doppler evaluation

We examined 21 patients with ischemic cerebrovascular disease using magnetic resonance angiography and transcranial Doppler. In 17 patients (81%), the results obtained by the two methods were concordant. In our opinion, the associated use of transcranial Doppler and magnetic resonance angiography provides an accurate diagnostic evaluation of ischemic stroke patients, not only allowing the site of possible steno-occlusive disease of large and medium cerebral vessels to be identified, but also offering the possibility of obtaining dynamic information concerning the direction of blood flow in the presence of compensatory circulations at the level of Willis' circle.