Contrasting HCV and HIV seroepidemiology in 11 years of blood donors screening in Brazil.

BACKGROUND: Blood donors are, in principle, healthy individuals who may be revealed as infectious for blood-borne agents by the laboratory screening process, depicting the asymptomatic burden of the disease. Therefore, monitoring hepatitis C virus (HCV)-infected donor and human immunodeficiency virus (HIV)-infected donor and associating to their demographical and behavioural characteristics may shed light on the dynamics and contemporary changes in these viruses' epidemiology. METHODS: Donors presenting repeatedly reactive HCV or HIV serology/nucleic acid testing (NAT) screening results were submitted to confirmatory testing. Confirmed positive donors were invited to return to the blood bank for notification and counselling when a follow-up sample was obtained and an interview performed to eventually disclose potential risks. HCV- or HIV-infected donors identified over 11 years of screening (2004-2015) were evaluated for demographic and behavioural parameters. RESULTS: In the period, 139 160 donations were screened, and 36 (0.025%) were found positive for HIV, stemming from 29 male and 7 female donors. Among those, eight subjects were repeat donors. A total of 95 donations were found repeatedly reactive for HCV (0.068%), obtained from 60 men and 35 women. Noticeably, in despite of a higher HCV prevalence in the donor population, the incidence of HIV among repeat donors was 10 times that of HCV (18 × 1.6/100 000 persons-year, respectively). On average, HIV-seroreactive men were found to be younger (mean = 34 years old) than women (mean = 40 years old). A total of 10 donors acknowledged sexual behaviours not previously informed, including 2 who were aware of their HIV-positive status and another 2 who admitted to be seeking HIV testing. No window period donation was verified. DISCUSSION: The majority of the HIV-infected donors are young males who deny risk factors in the interview and also ignore the confidence self-exclusion opportunity. As they may reiterate this behaviour in serial donations, use of the most sensitive laboratory testing is justified in this setting.

Fc gamma receptor IIIb polymorphism and systemic lupus erythematosus: association with disease susceptibility and identification of a novel FCGR3B*01 variant.

OBJECTIVE: The objective of this study was to evaluate the association between Fc gamma receptor IIIb polymorphism and susceptibility to systemic lupus erythematosus and clinical traits of the disease. METHODS: Genomic DNA was obtained from 303 consecutive systemic lupus erythematosus patients and 300 healthy blood donors from the southeastern region of Brazil. The polymorphic region of the FCGR3B gene was sequenced and the alleles FCGR3B*01, FCGR3B*02 and FCGR3B*03 were analyzed. RESULTS: The FCGR3B*01 allele was more frequent in systemic lupus erythematosus patients (43.1%) while the FCGR3B*02 allele prevailed among controls (63.7%) (P = 0.001). The FCGR3B*03 allele was found equally in both groups. The FCGR3B*01/*01 (20.7%) and FCGR3B*01/*02 (41.1%) genotypes were more frequent among systemic lupus erythematosus patients (P = 0.028 and P = 0.012, respectively) while the FCGR3B*02/*02 genotype was more frequent in controls (45.5%) (P < 0.001). One variant of the FCGR3B*01 allele previously described in Germany was found in only one control. A new variant of the FCGR3B*01 allele with two substitutions (A227G/G277A) was found in one control. Three variants of the FCGR3B*02 allele previously described in African-Americans, Brazilians, Chinese and Japanese were found in ten 10 patients and two controls. In addition, several single nucleotide polymorphisms at non-polymorphic positions were identified in both patients and controls. CONCLUSION: Susceptibility to systemic lupus erythematosus was associated with the FCGR3B*01 allele, as well as with the FCGR3B*01/*01 and FCGR3B*01/*02 genotypes. No association was found between FCGR3B genotypes and clinical manifestations, disease severity or the presence of autoantibodies.

Transfusions of CPDA-1 red blood cells stored for up to 28 days decrease donor exposures in very low-birth-weight premature infants.

The goal of this research was to study the safety and the efficacy of transfusing citrate-phosphate-adenine anticoagulant-preservative (CPDA-1) RBC stored for up to 28 days to reduce donor exposures in premature infants. A prospective randomized two-group study was conducted with very low-birth-weight premature infants that received at least one RBC transfusion during hospital stay. Neonates randomly assigned to Group 1 (26 infants) were transfused with CPDA-1 RBC stored for up to 28 days; those assigned to Group 2 (26 infants) received CPDA-1 RBC stored for up to 3 days. Demographic and transfusion-related data were collected. Neonates from both groups showed similar demographics and clinical characteristics. The number of transfusions per infant transfused was 4.4 +/- 4.0 in Group 1 and 4.2 +/- 3.1 in Group 2, and the number of donors per infant transfused was 1.5 +/- 0.8 (Group 1) and 4.3 +/- 3.4 (Group 2), P < 0.001. RBC transfusions containing 29.7 +/- 18.3 mmol L(-1) of potassium (RBC stored for up to 28 days) did not cause clinical or biochemical changes and reduced donor exposures by 70.2%, compared to transfusions containing 19.8 +/- 12.3 mmol L(-1) of potassium (RBC stored for up to 3 days), P < 0.001. In conclusion, RBC stored for up to 28 days safely reduced donor exposures in premature infants.

Drosophila germline invasion by the endogenous retrovirus gypsy: involvement of the viral env gene.

The endogenous retrovirus gypsy is expressed at high levels in mutant flamenco female flies. Gypsy viral particles extracted from such flies can infect naive flamenco individuals raised in the presence of these extracts mixed into their food. This results in the integration of new proviruses into the germline genome. These proviruses can then increase their copy number by (1) expression in the flamenco female somatic cells, (2) transfer into the oocyte and (3) integration into the genome of the progeny. Surprisingly, unlike the infection observed in the feeding experiments, this strategy of endogenous proviral multiplication does not seem to involve the expression of the viral env gene.

Evolution and phylogeny of insect endogenous retroviruses.

BACKGROUND: The genome of invertebrates is rich in retroelements which are structurally reminiscent of the retroviruses of vertebrates. Those containing three open reading frames (ORFs), including an env-like gene, may well be considered as endogenous retroviruses. Further support to this similarity has been provided by the ability of the env-like gene of DmeGypV (the Gypsy endogenous retrovirus of Drosophila melanogaster) to promote infection of Drosophila cells by a pseudotyped vertebrate retrovirus vector. RESULTS: To gain insights into their evolutionary story, a sample of thirteen insect endogenous retroviruses, which represents the largest sample analysed until now, was studied by computer-assisted comparison of the translated products of their gag, pol and env genes, as well as their LTR structural features. We found that the three phylogenetic trees based respectively on Gag, Pol and Env common motifs are congruent, which suggest a monophyletic origin for these elements. CONCLUSIONS: We showed that most of the insect endogenous retroviruses belong to a major clade group which can be further divided into two main subgroups which also differ by the sequence of their primer binding sites (PBS). We propose to name IERV-K and IERV-S these two major subgroups of Insect Endogenous Retro Viruses (or Insect ERrantiVirus, according to the ICTV nomenclature) which respectively use Lys and Ser tRNAs to prime reverse transcription.

HIV-1 and HIV-2 LTR nucleotide sequences: assessment of the alignment by N-block presentation, "retroviral signatures" of overrepeated oligonucleotides, and a probable important role of scrambled stepwise duplications/deletions in molecular evolution.

Previous analyses of retroviral nucleotide sequences, suggest a so-called "scrambled duplicative stepwise molecular evolution" (many sectors with successive duplications/deletions of short and longer motifs) that could have stemmed from one or several starter tandemly repeated short sequence(s). In the present report, we tested this hypothesis by focusing on the long terminal repeats (LTRs) (and flanking sequences) of 24 human and 3 simian immunodeficiency viruses. By using a calculation strategy applicable to short sequences, we found consensus overrepresented motifs (often containing CTG or CAG) that were congruent with the previously defined "retroviral signature." We also show many local repetition patterns that are significant when compared with simply shuffled sequences. First- and second-order Markov chain analyses demonstrate that a major portion of the overrepresented oligonucleotides can be predicted from the dinucleotide compositions of the sequences, but by no means can biological mechanisms be deduced from these results: some of the listed local repetitions remain significant against dinucleotide-conserving shuffled sequences; together with previous results, this suggests that interspersed and/or local mononucleotide and oligonucleotide repetitions could have biased the dinucleotide compositions of the sequences. We searched for suggestive evolutionary patterns by scrutinizing a reliable multiple alignment of the 27 sequences. A manually constructed alignment based on homology blocks was in good agreement with the polypeptide alignment in the coding sectors and has been exhaustively assessed by using a multiplied alphabet obtained by the promising mathematical strategy called the N-block presentation (taking into account the environment of each nucleotide in a sequence). Sector by sector, we hypothesize many successive duplication/deletion scenarios that fit our previous evolutionary hypotheses. This suggests an important duplication/deletion role for the reverse transcriptase, particularly in inducing stuttering cryptic simplicity patterns.

Evolution of the Gypsy endogenous retrovirus in the Drosophila melanogaster subgroup.

We conducted a phylogenetic survey of the endogenous retrovirus Gypsy in the eight species of the Drosophila melanogaster subgroup. A 362-bp fragment from the integrase gene (int) was amplified, cloned, and sequenced. Phylogenetic relationships of the elements isolated from independent clones were compared with the host phylogeny. Our results indicate that two main lineages of Gypsy exist in the melanogaster subgroup and that vertical and horizontal transmission have played a crucial role in the evolution of this insect endogenous retrovirus.

Proviral amplification of the Gypsy endogenous retrovirus of Drosophila melanogaster involves env-independent invasion of the female germline.

Gypsy is an infectious endogenous retrovirus of Drosophila melanogaster. The gypsy proviruses replicate very efficiently in the genome of the progeny of females homozygous for permissive alleles of the flamenco gene. This replicative transposition is correlated with derepression of gypsy expression, specifically in the somatic cells of the ovaries of the permissive mothers. The determinism of this amplification was studied further by making chimeric mothers containing different permissive/restrictive and somatic/germinal lineages. We show here that the derepression of active proviruses in the permissive soma is necessary and sufficient to induce proviral insertions in the progeny, even if the F1 flies derive from restrictive germ cells devoid of active proviruses. Therefore, gypsy endogenous multiplication results from the transfer of some gypsy-encoded genetic material from the soma towards the germen of the mother and its subsequent insertion into the chromosomes of the progeny. This transfer, however, is not likely to result from retroviral infection of the germline. Indeed, we also show here that the insertion of a tagged gypsy element, mutant for the env gene, occurs at high frequency, independently of the production of gypsy Env proteins by any transcomplementing helper. The possible role of the env gene for horizontal transfer to new hosts is discussed.

A Moloney murine leukemia virus-based retroviral vector pseudotyped by the insect retroviral gypsy envelope can infect Drosophila cells.

The gypsy element of Drosophila melanogaster is the first retrovirus identified so far in invertebrates. Previous data suggest that gypsy ENV-like ORF3 mediates viral infectivity. We have produced in the 293GP/LNhsp701ucL.3 human cell line a Moloney murine leukemia virus-based retroviral vector pseudotyped by the gypsy ENV-like protein. We have shown by immunostaining that the gypsy envelope protein is produced in 293GP/LNhsp701ucL.3 cells and that vector particles collected from these cells can infect Drosophila cells. Our results provide direct evidence that the infectious property of gypsy is due to its ORF3 gene product.

Retroviral oligonucleotide distributions correlate with biased nucleotide compositions of retrovirus sequences, suggesting a duplicative stepwise molecular evolution.

A computer-assisted analysis was made of 24 complete nucleotide sequences selected from the vertebrate retroviruses to represent the ten viral groups. The conclusions of this analysis extend and strengthen the previously made hypothesis on the Moloney murine leukemia virus: The evolution of the nucleotide sequence appears to have occurred mainly through at least three overlapping levels of duplication: (1) The distributions of overrepresented (3-6)-mers are consistent with the universal rule of a trend toward TG/CT excess and with the persistence of a certain degree of symmetry between the two strands of DNA. This suggests one or several original tandemly repeated sequences and some inverted duplications. (2) The existence of two general core consensuses at the level of these (3-6)-mers supports the hypothesis of a common evolutionary origin of vertebrate retroviruses. Consensuses more specific to certain sequences are compatible with phylogenetic trees established independently. The consensuses could correspond to intermediary evolutionary stages. (3) Most of the (3-6)-mers with a significantly higher than average frequency appear to be internally repeated (with monomeric or oligomeric internal iterations) and seem to be at least partly the cause of the bias observed by other researchers at the level of retroviral nucleotide composition. They suggest a third evolutionary stage by slippage-like stepwise local duplications.

About the origin of retroviruses and the co-evolution of the gypsy retrovirus with the Drosophila flamenco host gene.

The gypsy element of Drosophila melanogaster is the first retrovirus identified so far in invertebrates. According to phylogenetic data, gypsy belongs to the same group as the Ty3 class of LTR-retrotransposons, which suggests that retroviruses evolved from this kind of retroelements before the radiation of vertebrates. There are other invertebrate retroelements that are also likely to be endogenous retroviruses because they share with gypsy some structural and functional retroviral-like characteristics. Gypsy is controlled by a Drosophila gene called flamenco, the restrictive alleles of which maintain the retrovirus in a repressed state. In permissive strains, functional gypsy elements transpose at high frequency and produce infective particles. Defective gypsy proviruses located in pericentromeric heterochromatin of all strains seem to be very old components of the genome of Drosophila melanogaster, which indicates that gypsy invaded this species, or an ancestor, a long time ago. At that time, Drosophila melanogaster presumably contained permissive alleles of the flamenco gene. One can imagine that the species survived to the increase of genetic load caused by the retroviral invasion because restrictive alleles of flamenco were selected. The characterization of a retrovirus in Drosophila, one of the most advanced model organisms for molecular genetics, provides us with an exceptional clue to study how a species can resist a retroviral invasion.

Genomic signatures: tracing the origin of retroelements at the nucleotide level.

We investigate the nucleotide sequences of 23 retroelements (4 mammalian retroviruses, 1 human, 3 yeast, 2 plant, and 13 invertebrate retrotransposons) in terms of their oligonucleotide composition in order to address the problem of relationship between retrotransposons and retroviruses, and the coadaptation of these retroelements to their host genomes. We have identified by computer analysis over-represented 3-through 6-mers in each sequence. Our results indicate retrotransposons are heterogeneous in contrast to retroviruses, suggesting different modes of evolution by slippage-like mechanisms. Moreover, we have calculated the Observed/Expected number ratio for each of the 256 tetramers and analysed the data using a multivariate approach. The tetramer composition of retroelement sequences appears to be influenced by host genomic factors like methylase activity.

Flamenco, a gene controlling the gypsy retrovirus of Drosophila melanogaster.

Gypsy is an endogenous retrovirus of Drosophila melanogaster. It is stable and does not transpose with detectable frequencies in most Drosophila strains. However, we have characterized unstable strains, known as MG, in which it transposes at high frequency. These stocks contain more copies of gypsy than usual stocks. Transposition results in mutations in several genes such as ovo and cut. They are stable and are due to gypsy insertions. Integrations into the ovoD1 female sterile-dominant mutation result in a null allele of the gene and occurrence of fertile females. This phenomenon, known as the ovoD1 reversion assay, can be used to quantitate gypsy activity. We have shown that the properties of MG strains result from mutation of a host gene that we called flamenco (flam). It has a strict maternal effect on gypsy mobilization: transposition occurs at high frequency only in the germ line of the progeny of females homozygous for mutations of the gene. It is located at position 65.9 (20A1-3) on the X chromosome. The mutant allele present in MG strains is essentially recessive. Flamenco seems to control the infective properties of gypsy.

Penicillinase-producing gonococcal arthritis in a community hospital.

Disseminated Neisseria gonorrhoeae gonococcal infections are the leading cause of acute arthritis in young adults. Recent published information indicates that a small proportion of gonococcal arthritis is caused by penicillinase-producing Neisseria gonorrhoeae (PPNG). This article reports three cases of PPNG over a 12-month period and recommends that all suspected cases of gonococcal arthritis be treated as if they were PPNG until proven otherwise.

The full-length transcript of the I factor, a LINE element of Drosophila melanogaster, is a potential bicistronic RNA messenger.

The I factor of Drosophila melanogaster is a retrotransposon of the LINE superfamily. The I factor displays two non-overlapping open reading frames (ORFs) that have the potential to encode for a nucleic acid-binding protein (ORF1) and a reverse transcriptase (ORF2). Retrotransposition of the I factor has been demonstrated and a putative full-length RNA intermediate has been identified. No other transcript from functional I factor has ever been described, suggesting that the full-length RNA is also used as a messenger. Here we report that a bicistronic RNA which conserves the ORF1-ORF2 organization of the I factor transcript is a template for ORF2 translation in vivo. We further demonstrate that the first AUG of ORF2 initiates translation, but efficiency of this initiation increases approximately 200 fold when ORF1 is deleted. Our results show that the I factor transcript may be used to translate both ORFs from their own initiation codons at different rates. Various mechanisms of translation are proposed.

Retroviruses in invertebrates: the gypsy retrotransposon is apparently an infectious retrovirus of Drosophila melanogaster.

Retroviruses are commonly considered to be restricted to vertebrates. However, the genome of many eukaryotes contains mobile sequences known as retrotransposons with long terminal repeats (LTR retrotransposons) or viral retrotransposons, showing similarities with integrated proviruses of retroviruses, such as Ty elements in Saccharomyces cerevisiae, copia-like elements in Drosophila, and endogenous proviruses in vertebrates. The gypsy element of Drosophila melanogaster has LTRs and contains three open reading frames, one of which encodes potential products similar to gag-specific protease, reverse transcriptase, and endonuclease. It is more similar to typical retroviruses than to LTR retrotransposons. We report here experiments showing that gypsy can be transmitted by microinjecting egg plasma from embryos of a strain containing actively transposing gypsy elements into embryos of a strain originally devoid of transposing elements. Horizontal transfer is also observed when individuals of the "empty" stock are raised on medium containing ground pupae of the stock possessing transposing elements. These results suggest that gypsy is an infectious retrovirus and provide evidence that retroviruses also occur in invertebrates.

Admission hyponatremia in the elderly: factors influencing prognosis.

The authors studied the occurrence of admission hyponatremia and its association with selected patient and hospitalization characteristics and in-hospital mortality in a geriatric patient cohort (n = 4,123). Prevalence of admission hyponatremia was 3.5% and higher among women (4.6% vs 2.6%). In-hospital mortality was 16% for patients with admission hyponatremia versus 8.0% for patients without admission, hyponatremia. Adjusting for patient and hospitalization characteristics with a logistic regression analysis, admission hyponatremia was a significant independent predictor of mortality (RR = 1.95). Admission hyponatremia is associated with poor prognosis in the elderly hospitalized population.

Aminophylline hypersensitivity apparently due to ethylenediamine.

Asthmatic patients receive multiple drugs as part of their treatment program. When a subsequent allergic reaction occurs, the ethylenediamine component of aminophylline is usually not suspected as the etiologic agent. We present a case of ethylenediamine-induced delayed hypersensitivity reaction in a 46-year-old woman who received parenteral aminophylline for an acute asthma exacerbation. Patch testing for ethylenediamine was positive.

The effect of incomplete knowledge on the diagnoses of a computer consultant system.

The knowledge bases (KBs) of diagnostic decision support systems are often incomplete, and gaps in the KB could potentially lead systems to reach diagnoses that are implausible to physicians. To investigate this possibility we studied Iliad (Version 2.01), a computer consultant system that generates differential diagnosis across the domain of internal medicine. Data from the history, physical examination, and laboratory findings of 50 grand-rounds cases were entered into Iliad by a computer consultant aware of the diagnosis but blinded to its presence or absence in Iliad's KB. Two experienced internists were asked to diagnose these cases before and after seeing the results of the computer consultation, and to assess the plausibility of the computer's diagnoses. Twenty-eight of the 50 cases (56.0%) were diseases contained in Iliad's KB. After seeing Iliad's diagnoses for cases in the KB, physicians assigned to their correct diagnoses a higher mean ranked position (1.5 versus 2.0, p less than 0.008) and a higher mean probability (84.0% versus 77.6%, p less than 0.008) compared with their pre-Iliad values, whereas for cases not in the KB, mean position and probability for correct diagnoses did not change. Physician diagnostic accuracy did not change after consultation on cases included or not included in the KB. After adjusting for case difficulty, mean plausibility of Iliad's diagnoses was judged significantly higher (on a seven-point scale) for cases in the KB than for cases not in the KB (4.2 versus 3.2, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)