[Blood-brain barrier evaluation in bone marrow transplantation]

The blood-brain barrier (BBB) contributes to the central nervous system (CNS) immunological isolation. BBB has never been studied in patients who developed chronic graft-versus-host disease (GVHD) after allogeneic bone marrow transplants (BMT), from HLA identical related donors. BBB disruption was investigated through the cerebrospinal fluid (CSF) proteins, quantitative and graphically, in order to detect the incidence and possible pathophysiology of the CNS involvement in chronic GVHD. Thirty three CSF and matched serum samples from chronic myeloid leukemia patients were collected pre BMT pos BMT and during chronic GVHD. There was no evidence of BBB disruption in any patient studied.

Is oral sotalol effective in converting atrial fibrillation to sinus rhythm?

d,l-Sotalol is a noncardioselective beta-blocker that has class III antiarrhythmic activity. It is often used to convert atrial fibrillation (AF) to normal sinus rhythm. Since class III agents increase action potential duration and refractoriness in atrial tissue without affecting conduction, they are theoretically considered ideal agents for the treatment of reentrant arrhythmias such as AF. We reviewed the literature evaluating the efficacy of sotalol for restoring sinus rhythm in patients with acute or chronic AF. Articles indexed on MEDLINE (1966-1996) and referenced articles not identified by MEDLINE that compared sotalol with placebo or another antiarrhythmic agent were included. Sotalol was significantly inferior to quinidine in converting AF of recent onset (< 48 hrs) to sinus rhythm. In patients with duration of AF of more than 48 hours, sotalol was significantly less effective than quinidine and comparable with placebo. Conversion rates for sotalol in all studies combined ranged from 8-49%. Published studies do not support the drug for conversion of AF to sinus rhythm. Larger well-designed studies are required to evaluate its efficacy and optimum dosage for this indication. Until further data are available, pharmacologic cardioversion with traditional class I antiarrhythmic agents may be preferable as they are effective particularly for recent-onset AF.

The Ets transcription factors interact with each other and with the c-Fos/c-Jun complex via distinct protein domains in a DNA-dependent and -independent manner

The transcription factors Fos, Jun, and Ets regulate the expression of human stromelysin-1 and collagenase-1 genes. Recently, we found that ERG, an Ets family member, activates collagenase-1 gene but not stromelysin-1 by physically interacting with c-Fos/c-Jun. Interestingly, ERG binds to stromelysin-1 promoter and represses its activation by ETS2. Here, to investigate the molecular mechanism of this regulation, we have used an in vitro protein-protein interaction assay and studied the transcription factor interactions of ETS2. We found that ETS2 could weakly associate with in vitro synthesized ETS1, c-Fos, and c-Jun and strongly with c-Fos/c-Jun complex and ERG via several distinct ETS2 domains including the C-terminal region that contains the DNA-binding domain. Strikingly, these interactions were stabilized in vitro by DNA as they were inhibited by ethidium bromide. Both the N-terminal region, comprising the transactivation domain, and the C-terminal region of ETS2 associated with ERG and, interestingly, the interaction of ERG through the transactivation domain of ETS2 was DNA-independent. The DNA-dependent interaction of ETS2 with c-Fos/c-Jun was enhanced by specific DNA fragments requiring two Ets-binding sites of the stromelysin-1 promoter. Using the two hybrid system, we also demonstrated that ETS2 interacts with c-Jun or ERG in vivo.

Outcome of cord-blood transplantation from related and unrelated donors. Eurocord Transplant Group and the European Blood and Marrow Transplantation Group

BACKGROUND

Cord-blood banks have increased the use of cord-blood transplantation in patients with hematologic disorders. We have established a registry containing information on the outcome of cord-blood transplantation.

METHODS

We sent questionnaires to 45 transplantation centers for information on patients receiving cord-blood transplants from 1988 to 1996. Reports on 143 transplantations, performed at 45 centers, were studied, and the responses were analyzed separately according to whether the donor was related or unrelated to the recipient.

RESULTS

Among 78 recipients of cord blood from related donors, the Kaplan-Meier estimate of survival at one year was 63 percent. Younger age, lower weight, transplants from HLA-identical donors, and cytomegalovirus-negative serologic results in the recipient were favorable prognostic factors. Graft-versus-host-disease of at least grade II occurred at estimated rates of 9 percent in 60 recipients of HLA-matched cord blood and 50 percent in 18 recipients of HLA-mismatched cord blood. Neutrophil engraftment was associated with an age of less than six years (P = 0.02) and a weight of less than 20 kg (P = 0.02), and it occurred in 85 percent of patients receiving 37 million or more nucleated cells per kilogram of body weight. Among 65 patients who received cord blood from unrelated donors, the Kaplan-Meier estimate of survival at one year was 29 percent. Cytomegalovirus-negative serologic status in these recipients was associated with improved survival (P = 0.03) and was the most important predictor of graft-versus-host disease (P = 0.04). Neutrophil recovery occurred in 94 percent of the patients who received 37 million or more nucleated cells per kilogram from unrelated donors.

CONCLUSIONS

Cord blood is a feasible alternative source of hematopoietic stem cells for pediatric and some adult patients with major hematologic disorders, particularly if the donor and the recipient are related.

Physical mapping 220 kb centromeric of the human MHC and DNA sequence analysis of the 43-kb segment including the RING1, HKE6, and HKE4 genes

A cosmid contig was constructed from a YAC clone with a 220-kb insert that spans the centromeric side of the human MHC class II region, corresponding to the mouse t complex. The gene order was identified to be HSET-HKE1.5-HKE2-HKE3-RING1-HKE6- HKE4 (RING5). The genomic sequence of a 42,801-bp long region encoded by one cosmid clone in the RING1, HKE6, and HKE4 subregions was determined by the shotgun method. The exon-intron organization of these three genes, RING1 (Ring finger protein), HKE6 (steroid dehydrogenase-like protein), and HKE4 (transmembrane protein with histidine-rich charge clusters), was determined. The previously reported RING2 gene was revealed to be identical to HKE6. Transcripts from HKE4 were detected in the placenta, lung, kidney, and pancreas. Those of HKE6 were found in the liver and pancreas. The 25-kb region proximal to the RING1 gene includes an extensive dense cluster of Alu repeats (about 1.2 Alu per kb), and no gene has been identified in this so far. The region is equivalent to part of the mouse t complex and could be of relevance to human development.

High-level tetracycline resistant Neisseria gonorrhoeae isolated in Portugal

The first high-level tetracycline resistance (MIC > or = 16 mg/l) isolates of Neisseria gonorrhoeae (TRNG) were reported in 1990 from patients attending a Sexual Transmitted Disease (STD) Center in Lisbon. The TRNG prevalence was 4% in 1991, 5.3% in 1992 and 10,8% in 1994, exploding to 52.2% in 1995. The tet M determinant was evaluated by PCR. The digests of PCRP using HpaII produced the restriction pattern 2 for all the strains, except one (pattern 3). 78.3% of the TRNG strains were beta-lactamase producers and the 4.5 MDa penicillinase plasmid was the dominant (83%), 90% and 93.3% of the TRNG strains belonged to the auxotype NR and to the serogroup IA, respectively. The IA-8/NR class represented 58.3% of the TRNG isolates, suggesting a clonal spreading.

Suicide attempted by burning in Brazil

From 1984 through 1995, a total of 82 patients were admitted to the Burn Center of the University Hospital of Ribeirão Preto, University of São Paulo with a history of attempted suicide. Fifty-eight patients were female and 24 were male. The mean burned surface area (BSA) was 52.4 per cent and the mortality rate was 44 per cent. Methyl alcohol was used by 87.5 per cent of the patients to ignite the fire.

Characteristic generated alterations of autoantibody patterns in idiopathic thrombocytopenic purpura

Using a Western blot technique that allows quantitative detection of antibody reactivities to a large number of antigens, serum IgG and IgM antibody repertoires were compared in a group of 19 patients with a diagnosis of idiopathic thrombocytopenic purpura (ITP) and respective healthy controls. The results show that, irrespective of the duration of thrombocytopenia, age of the patients, and type of therapy, all ITP donors share characteristic alterations of serum antibody reactivity patterns on homologous erythrocyte and liver antigens. Multiparametric analyses of the immunoreactivity data readily segregated the groups of ITP and healthy donors. Similar analyses also distinguished ITP sera from those of a group of patients with systemic lupus erythematosus (SLE). We conclude that ITP is an autoimmune disease associated with generalized alterations of antibody repertoires, that may be characteristic enough to allow for diagnosis.

Instability of natural antibody repertoires in systemic lupus erythematosus patients, revealed by multiparametric analysis of serum antibody reactivities

Recent views on autoimmune diseases invoke generalized but specific perturbations in antibody repertoires, rather than the clonally restricted or non-specific polyclonal alterations proposed thus far. The present experiments analyse serum antibody reactivities in 24 systemic lupus erythematosus (SLE) patients and 17 healthy controls, using a method that quantitatively scores a large number of antibody reactivities and allows for multiparametric statistical analyses. The results show global but relatively specific perturbations in SLE antibody repertoires, and identify novel disease-associated reactivity patterns. Furthermore, a time series analysis of serum antibodies over 3 months demonstrates instability of natural antibody repertoires in individual SLE patients, contrasting with their remarkable conservation in healthy donors. Moreover, the method used clusters controls and patients independently, and might prove of diagnostic value, once large data bases are established.

Function of ets genes is conserved between vertebrates and Drosophila

The Drosophila pointed gene encodes two ETS transcriptional activators, pointedP1 and pointedP2, sharing a common C-terminal ETS domain. In the embryonic central nervous system pointedP2 is required for midline glial cell differentiation, whereas, in the eye, pointedP2 is essential for photoreceptor cell differentiation. Both vertebrate c-ets-1 and c-ets-2 gene ETS domains are highly homologous to the one of pointed. In addition, the N-terminal region of pointedP2 and vertebrate ets products share another homologous domain, the so-called RII/pointed box which appears to mediate the ras-dependent phosphorylation/stimulation. Here, we show that the vertebrate ets genes are functionally homologous to the Drosophila pointed gene. pointedP2 efficiently binds to an optimized c-Ets-1/c-Ets-2 probe in vitro, and stimulates two distinct c-Ets-1/c-Ets-2-responsive sequences when transiently expressed in vertebrate cells. Conversely, when vertebrate ets transgenes are expressed during fly development, they are capable of rescuing the pointed mutant phenotype in both midline glia and photoreceptor development. As ectopically expressed pointedP1 can also rescue pointedP2 deficiency in photoreceptor development, it appears that the ability of ets products to phenocopy each other in vivo does not require the conserved RII/pointed box, but rather, primarily relies on the presence of the highly conserved ETS domain.

Antimalarial activity of oxidized starch and cellulose imine derivatives

With the purpose of screening potential antimalarial agents, oxidized starch imine derivatives of sulfonamides or pyrimidine - derivatives of sulfisoxazole (ML8), sulfameter (ML11) and trimethoprim (ML13) - and oxidized cellulose imine derivatives of dapsone (ML14), sulfadiazine (ML17), sulfamethoxazole (ML18), sulfisoxazole (ML19), sulfamethoxypyridazine (ML20) and sulfameter (ML22) were submitted to in vivo biological assays with mice infected with Plasmodium berghei. Only ML11 was 100% curative in test conditions; ML 17 showed the same effect as its prototype. The drug content in both prodrugs is lower in the applied dose than that used in the original drugs. It can be suggested that the latentiation enhanced the effectiveness of the prototypes.

[Primary lymphomas of the brain not related to immunodeficiency]

Primary brain lymphoma (PBL) is a rare disease, the study of which is based on small series and case reports. The AA review new cases of PBL not associated to immunodeficiency at the Portuguese Institute of Oncology of Porto since 1978. Five male patients were found with lymphoma primarily located in the brain, with aggressive histology, IE staging, detected by CAT, NMR or brain scintigraphy and with histologic material collected by stereotaxic biopsy (3 cases) or by craniotomy (2 cases). Three patients were in complete remission (25,5 and 1 year) and 2 were dead with a survival of 12 and 17 months. The cases and literature are discussed.

Cerebral toxoplasmosis after renal transplantation. Case report and review

Infection caused by Toxoplasma gondii is a frequent event in Portugal. When this occurs in immunocompetent individuals, it is rarely a matter of concern; the contrary occurs with immunosuppressed patients or in pregnancy. Transplant patients are treated with immunosuppressive drugs which mainly disturb their mechanisms of cellular immunity, and that opens the way to infections by opportunistic intracellular microorganisms. We recently treated a renal transplant patient who suffered from cerebral toxoplasmosis, and this provided an opportunity for a review of the other 20 patients reported in medical literature to date.

A model for gene evolution of the ets-1/ets-2 transcription factors based on structural and functional homologies

The chicken c-ets-1 locus encodes two transcription factors, p54c-ets-1 and p68c-ets-1 that differ in their N-termini, encoded respectively by the I54 and alpha beta exons. p68c-ets-1 equivalents are only found in birds and reptiles while p54c-ets-1 is widely conserved in vertebrates, from amphibians to mammals. Thus, the classical view concerning the evolution of the c-ets-1 gene has been to consider that I54 is of ancient origin whereas alpha and beta, which provide an additional activating domain in p68c-ets-1, would have been acquired much more recently. Sequencing the alpha and beta exons in various species pinpointed a highly conserved region of 13 amino acids which is rich in acidic and hydrophobic residues, a feature of some other transactivating domains. Strikingly, this subdomain is also present in the otherwise unrelated N-terminal activating region of p58c-ets-2 and was thus named BEC for Ets-1-beta/Ets-2-Conserved sequence. Moreover, the two N-termini share the BEC sequence at a homologous position in their highly similar genomic organization indicating a common origin. This structural homology underlies a functional similarity since fusion of the heterologous GAL4 DNA-binding domain with either of the two isolated domains demonstrates that BEC is essential in both cases for the transactivating activity. The function of the alpha beta domain in the context of p68c-ets-1 also strictly depends on the presence of the BEC sequence. Finally, the whole N-terminus of p58c-ets-2 can functionally substitute for its counterpart in p68c-ets-1 further demonstrating that p68c-ets-1 and p58c-ets-2 are structurally and functionally more closely related than previously thought. Besides, we also found BEC in the N-terminus of the Drosophila pointed gene which may be considered as closely related to the uncommitted 'ets1/2' common ancestor. These data demonstrate that the alpha and beta exons are not a recent and specific acquisition but stem, like the p58c-ets-2 N-terminus, from the invertebrate unduplicated 'ets 1/2' gene. This work unravels a new model for the ets-1/ets-2 gene's evolution, based for the first time on both structural and functional evidences. Accordingly, p68c-ets-1 and p58c-ets-2 are the direct descendants of the ancestral 'ets1/2' gene whereas I54 may have been acquired as a second promoter in the c-ets-1 gene after the duplication. Indeed, I54 is not found in the Drosophila pointed gene. The high degree of similarity, and hence of functional redundancy, between p68c-ets-1 and p58c-ets-2 may have led to the rapid divergence (and even loss in mammals) of alpha and beta during evolution whereas I54, which provided a novel function unique to c-ets-1, was maintained within the presently widespread p54c-ets-1 version.

Identification and analysis of the chicken c-mil promoter: possible involvement of Sp1- and Ets-related proteins

We have determined the exon organization in the 5' region of the chicken c-mil gene and identified its promoter. A 0.44-kb fragment containing the 5' terminus of the c-mil gene showed strong promoter activity when placed upstream of the bacterial chloramphenicol acetyltransferase gene and transfected into chicken embryo fibroblasts (CEF). By primer extension analysis, multiple transcriptional start sites were detected within the promoter region. Nucleotide sequence analysis revealed that the c-mil promoter had a high G + C content (71.8%) and contained multiple GC box-like sequences, but no TATA or CAAT boxes. Deletion analysis of 5' upstream sequences showed that the minimal region required for maximal promoter activity in CEF resides in the 99 bp located immediately upstream of the major initiation site. This region contains two putative Sp1 binding sites and one PU box/PEA3 motif, defined as a recognition element for members of the Ets gene family. These sequences bound proteins present in nuclear extracts of CEF as well as in vitro synthesized Ets-related proteins, suggesting that the binding of Sp1 or related proteins and of Ets-related proteins within the promoter is important for modulation of the mil gene.

[Cerebral toxoplasmosis in a kidney transplant patient. A clinical case and review of the literature]

Infection caused by Toxoplasma gondii is a frequent event in Portugal. When this occurs in immunocompetent individuals it is rarely a matter of concern; the contrary occurs with immunosuppressed patients or in pregnancy. Transplant patients are treated with immunosuppressive drugs which mainly disturb their mechanisms of cellular immunity, and that opens the way to infections by opportunistic intracellular microorganisms. We recently treated a renal transplant patient who suffered from cerebral toxoplasmosis, and this provided an opportunity for a review of the other 20 patients reported in medical literature to date.

[Resistance to antibiotics of vibrio cholerae strains isolated in Angola]

Among 87 strains of Vibrio choleare (78 Ogawa serotype and 9 Inaba serotype strains) isolated in Angola in 1987-1990, 86% exhibited multiple resistance to antimicrobials. Eighty-four to 86% of strains were resistant to ampicillin with beta-lactamase production (MIC greater than or equal to 512 mg/l), streptomycin (MIC greater than or equal to 64 mg/l), spectinomycin (MIC greater than or equal to 1,024 mg/l), and trimethoprime-sulfisoxazole (MIC greater than 1,024 mg/l). Seventy-four per cent of strains were resistant to kanamycin (MIC = 512 mg/l), 26% to chloramphenicol (MIC = 32 mg/l), 10% to tetracycline (MIC = 16 mg/l), and 10% to gentamycin (MIC greater than or equal to 32 mg/l). Transfer to E. coli K12 was associated with a substantial increase in expression of resistance to tetracycline and chloramphenicol (CAT type I), with MICs in the 128-512 mg/l range. Transfer rates to E. coli K12 of plasmids for the various resistance phenotypes were 10(-6)/10(-8). The size of the isolated plasmids was 100 Md in diameter and belonged to the incompatibility group inc 6-C.

[The pathogen spectrum and its resistance behavior in children with urinary tract infections in Angola]

In 225 children (135 boys, 90 girls) suffering from clinical relevant urinary tract infection the bacterial spectrum and resistance behaviour to routinely used antibiotics were evaluated. In 65.4% of the patients a significant bacteriuria was found: E. coli (34.6%), proteus (22.3%), klebsiella (14.6%), citrobacter (9.2%), enterobacter (5.4%) and pseudomonas (5.4%). In testing a high resistance of bacterias to trimethoprim/sulfamethoxazol, ampicillin, and gentamycin was found, whereas good susceptibility was found to nitrofurantoin and nalidixin acid.