Genome wide selection in Citrus breeding.

Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seqTM (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

A human IFNGR1 small deletion hotspot associated with dominant susceptibility to mycobacterial infection.

The immunogenetic basis of severe infections caused by bacille Calmette-Guérin vaccine and environmental mycobacteria in humans remains largely unknown. We describe 18 patients from several generations of 12 unrelated families who were heterozygous for 1 to 5 overlapping IFNGR1 frameshift small deletions and a wild-type IFNGR1 allele. There were 12 independent mutation events at a single mutation site, defining a small deletion hotspot. Neighbouring sequence analysis favours a small deletion model of slipped mispairing events during replication. The mutant alleles encode cell-surface IFNgamma receptors that lack the intra-cytoplasmic domain, which, through a combination of impaired recycling, abrogated signalling and normal binding to IFNgamma exert a dominant-negative effect. We thus report a hotspot for human IFNGR1 small deletions that confer dominant susceptibility to infections caused by poorly virulent mycobacteria.

Citrus leprosis virus C Naturally Infecting Commelina benghalensis, a Prevalent Monocot Weed of Citrus Orchards in Brazil.

There are two bacilliform, rhabdo-like viruses that cause citrus leprosis: Citrus leprosis virus C (CiLV-C), which accumulates in the cytoplasm of infected cells, and Citrus leprosis virus nuclear type (CiLV-N), which accumulates in their nucleus. The first one, the prototype of the new genus Cilevirus, is prevalent and occurs in several countries of the American continent, from Argentina to Mexico (1). The second type, still a tentative member of the Rhabdoviridae family, is of rare occurrence, with a few reports in Brazil and one in Panama (1). Leprosis is particularly important to the Brazilian citrus industry because of the 60 to 80 million dollars spent yearly for the control of Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae), the vector of the virus (1). For decades, the disease was considered unique to citrus plants; however, greenhouse experiments conducted in the 1990s demonstrated the mechanical transmission of CiLV-C to noncitrus plants (1). Years later, researchers were able to transmit the virus to nonrutaceous hosts using viruliferous mites (1,4). Recently, León et al. (2) reported the occurrence of the first noncitrus plant naturally infected by CiLV-C, the rutaceous Swinglea glutinosa Blanco (Merr.). Tropical spiderworts (Commelina benghalensis L.; Commelinaceae) are monocot weeds commonly found in citrus orchards in Brazil. In a survey conducted in orchards with high incidences of leprosis in the municipalities of Borborema and São José do Rio Preto, State of Sao Paulo, Brazil, tropical spiderworts were found exhibiting necrotic spots with a yellow halo in green leaves and green spots with necrotic center in senescent leaves. Since these symptoms are similar to those caused by CiLV-C in citrus, symptomatic plants were collected and subjected to transmission electron microscopy analyses and reverse transcription-PCR using primers that specifically amplify a region within the putative movement protein gene of the virus (3). Bacilliform virus particles and typical inclusions were seen in the lesions. Bands of the expected 344 bp size were seen in agarose gels of symptomatic samples only. The analysis of the consensus sequence showed 100% identity with CiLV-C sequence available in the GenBank (Accession No. YP_654542.1). Experimental transmission of CiLV-C by B. phoenicis reproduced the lesions in inoculated tropical spiderwort. Also, the virus could be easily transmitted back from C. benghalensis to sweet orange plants. Our data show that this widespread weed is the first monocot as a natural host for CiLV-C. Since tropical spiderwort is a host for B. phoenicis and symptomatic plants were found in two municipalities 130 km apart from each other, it is possible that this weed may serve as reservoir for the virus and play a relevant role in the spread of the disease in the field, but this issue still needs to be addressed in further experiments. References: (1) M. A. Bastianel et al. Plant Dis. 94:284, 2010. (2) M. G. A. Leon et al. Plant Dis. 90:682, 2008. (3) E. C. Locali-Fabris et al. Plant Dis. 87:1317. (4) M. A. Nunes et al. Plant Dis. Online publication. doi:10.1094/PDIS-06-11-0538, 2011.

HIV evolution: CTL escape mutation and reversion after transmission.

Within-patient HIV evolution reflects the strong selection pressure driving viral escape from cytotoxic T-lymphocyte (CTL) recognition. Whether this intrapatient accumulation of escape mutations translates into HIV evolution at the population level has not been evaluated. We studied over 300 patients drawn from the B- and C-clade epidemics, focusing on human leukocyte antigen (HLA) alleles HLA-B57 and HLA-B5801, which are associated with long-term HIV control and are therefore likely to exert strong selection pressure on the virus. The CTL response dominating acute infection in HLA-B57/5801-positive subjects drove positive selection of an escape mutation that reverted to wild-type after transmission to HLA-B57/5801-negative individuals. A second escape mutation within the epitope, by contrast, was maintained after transmission. These data show that the process of accumulation of escape mutations within HIV is not inevitable. Complex epitope- and residue-specific selection forces, including CTL-mediated positive selection pressure and virus-mediated purifying selection, operate in tandem to shape HIV evolution at the population level.

Detection of Brevipalpus-transmitted viruses in their mite vectors by RT-PCR.

The diagnosis of plant diseases caused by Brevipalpus-transmitted viruses (BrTVs) has been done through the analyses of symptoms, transmission electron microscopy, and RT-PCR of infected plant tissues. Here, we report the detection of Citrus leprosis virus C, Orchid fleck virus, Clerodendrum chlorotic spot virus and Solanum violaefolium ringspot virus in their viruliferous vectors Brevipalpus spp. using specific primer pairs for each of the viruses. The efficiency of virus transmission by Brevipalpus mites is low, so the detection of these pathogens in their vectors could constitute an important tool for studies involving virus-vector relationships, transmission, and monitoring the pathogen prior to the appearance of symptoms in the field.

Prevention of nosocomial legionellosis by best water management: comparison of three decontamination methods.

BACKGROUND: Since 2000, the National Health System has adopted international guidelines for assessing Legionella spp. in hospital water systems. The control of water contamination by Legionella spp. is still a matter of research concerning the most effective method in preventing nosocomial infections. AIM: To compare three different decontamination methods by monitoring colony-forming unit count and number of hospital-acquired legionellosis cases. A secondary objective was to evaluate the long-term effects of the preventive measures on the water pipes. METHODS: A protocol was developed for the selection of high-risk sampling sites and for the testing of three disinfection methods over the course of 19 years: hyperchlorination and thermal shock (period A, 2000-2005); copper-silver ionization (period B, 2006-2010); and integration of pre-filtering, filtering, pipe-protecting products, and remote control with chlorine dioxide (ClO2) (period C, 2011-2018). FINDINGS: The use of shock disinfection and hyperchlorination led to a decrease in contamination level immediately after the procedure, but then it rose again to the previous level in two months. Both copper-silver ionization and ClO2 disinfection showed a stable and durable decrease in contamination level. Throughout these three phases, six cases of Legionella spp. occurred during period A, six cases during period B, and three cases during period C. With regard to the damage of water pipes, effective copper-silver levels caused corrosion and calcification in water pipes. CONCLUSION: Both copper-silver ionization and ClO2 properly controlled Legionella spp. contamination. ClO2 significantly reduced the number of positive sites (P < 0.001) without damaging the pipelines.

An evaluation of the completeness of reporting of childhood tuberculosis.

The sensitivity of the Enhanced Tuberculosis Surveillance (ETS) scheme for monitoring tuberculosis in children is unknown. We used the British Paediatric Surveillance Unit (BPSU) reporting scheme to conduct a prospective observational study of tuberculosis in children aged <16 yrs in the UK. Reported cases were then matched with records from the ETS database. A total of 320 cases were reported to the BPSU between January and December 2004. We estimated that there were 557 paediatric cases in England, Wales and Northern Ireland in 2004: 222 (40%) cases reported to both BPSU and ETS, 98 (18%) reported to BPSU but not ETS and 237 (42%) reported to ETS but not BPSU. Children aged <5 yrs were significantly less likely to be reported to ETS compared with older children (p<0.01). There is substantial under-reporting of childhood tuberculosis, especially of children aged <5 yrs. ETS provides a representative picture of the demographics but may miss approximately 20% of cases. This should be taken into account when planning training and resource requirements for tuberculosis. Increased efforts are needed to ensure that all paediatric cases are reported to ETS.

Diversity and Genetic Variation among Brevipalpus Populations from Brazil and Mexico.

Brevipalpus phoenicis s.l. is an economically important vector of the Citrus leprosis virus-C (CiLV-C), one of the most severe diseases attacking citrus orchards worldwide. Effective control strategies for this mite should be designed based on basic information including its population structure, and particularly the factors that influence its dynamics. We sampled sweet orange orchards extensively in eight locations in Brazil and 12 in Mexico. Population genetic structure and genetic variation between both countries, among locations and among sampling sites within locations were evaluated by analysing nucleotide sequence data from fragments of the mitochondrial cytochrome oxidase subunit I (COI). In both countries, B. yothersi was the most common species and was found in almost all locations. Individuals from B. papayensis were found in two locations in Brazil. Brevipalpus yothersi populations collected in Brazil were more genetically diverse (14 haplotypes) than Mexican populations (four haplotypes). Although geographical origin had a low but significant effect (ca. 25%) on the population structure, the greatest effect was from the within location comparison (37.02 %). Potential factors driving our results were discussed.

Combined vaccine against measles, mumps, rubella, and varicella.

A combined measles, mumps, rubella, and varicella vaccine produced seroconversions for all four components similar to that found if measles, mumps, and rubella vaccine or live varicella vaccine were given separately. In addition, those exposed to varicella were completely protected or had only a mild rash. Moreover, the reaction rates were not increased if the vaccines were combined. The somewhat lower and delayed serologic response to live varicella vaccine as compared with the combined measles, mumps, rubella, and varicella may have been due to the small amount of varicella vaccine virus used or to its degree of attenuation. Persistence of antibody was observed 1 year postimmunization.

Varicella-like illness caused by live varicella vaccine in children with acute lymphocytic leukemia.

A varicella-like illness occurred in five of 52 children with acute lymphocytic leukemia following the administration of live varicella vaccine. Only one of the children required treatment with acyclovir. Virus isolated from two of the children was "vaccine-like" but differed slightly from the original vaccine strain when tested by restriction enzyme analysis. There did not appear to be a reversion to virulence because two of the household contacts who seroconverted had mild or subclinical infections. Vaccinees in whom this reaction developed tended to have a poor cellular immune response to varicella-zoster virus.

High prevalence of human immunodeficiency virus infection in children with thalassemia exposed to blood imported from the United States.

PIP: 38.5% or 10 of 26 children with thalassemia who had received blood transfusion have tested positive for HIV at the Hamad General Hospital, Doha, Qatar. Blood for transfusion was obtained from commercial suppliers in Miami, Florida, since late 1970. Since December 1985 all blood for transfusion has been tested for HIV for ELISA kits from Abbott Laboratories, Chicago, Ill, and confirmed by Western Blot. These children ranged from 3-13 years old, mean 7.7, and had received an average of 63.5 transfusions. All had been given at least 30 transfusions. Children testing negative for HIV averaged 35.0 lifetime transfusions. 4 of the affected children had persistent generalized lymphadenopathy, but no other symptoms were recorded.^ieng

Tuberculosis of the central nervous system in children: a 20-year survey.

OBJECTIVE: To review our experience of central nervous system (CNS) tuberculosis at a major British paediatric tertiary referral centre, following the introduction of CT Scan facilities. METHODS: This was a retrospective case survey (prospective in nine patients) of patients admitted to Great Ormond Street over a 20-year period (1977-1997), who fulfilled criteria for a diagnosis of CNS tuberculosis. Data were collected with regard to the clinical, laboratory and demographic characteristics of patients, as well as results of radiological investigations and data on clinical outcome. RESULTS: We identified 38 children with CNS tuberculosis: 23 with tuberculous meningitis (TBM), 10 with tuberculous meningitis and associated tuberculomas and five with tuberculomas alone. The mean age of this group was 3.7 years, ranging from 8 months to 16 years. Only 14 (37%) were of Caucasian origin. A contact source was identified in 18 patients (47%). Previous BCG had only been given to six (16%). The main clinical symptoms and signs present on admission were alteration in consciousness in 30 patients (79%), focal neurological signs in 25 (66%) and fever in 25 (66%). Seizures were observed in 20 patients (53%) and meningism in 18 (47%). Mycobacterium tuberculosis was either cultured or identified by acid-fast stain from CSF or brain tissue from 24 patients (63%). The Mantoux reaction was positive in 17/33 (51%); abnormalities of the chest X-ray were found in 15 (40%). Cranial CT scans of the patients presenting with TBM showed hydrocephalus in 31 patients (94%), and basilar enhancement in 27 (93%) out of the 29 patients who received intravenous contrast. Anti-tuberculous therapy administered varied according to current recommendations of the period; concurrent steroids were given to 31 patients (82%). Neurosurgical procedures were required in the majority of patients with TBM, 25 (76%). In five patients with TBM, new tuberculoma developed during treatment. The overall mortality for our group of patients was 13%, whilst permanent neurological sequelae were seen in 47% of the patients. None of the patients who received BCG either died or had severe sequelae. Mortality and morbidity rates were higher in the first 10 years of the study and amongst those patients admitted in Stage III disease. CONCLUSIONS: CNS tuberculosis continues to be a condition which carries significant morbidity and mortality. Early diagnosis and prompt initiation of treatment are essential to improve the poor outcome.

Salmonella osteomyelitis in sickle cell disease children in the east end of London.

Five cases of Salmonella osteomyelitis are presented in children with sickle cell disease living in the East End of London. Four of these had involvement of the long bones and one (an infant) presented with hand-foot syndrome. Four required surgical drainage of pus and all required lengthy therapy with antibiotics. Factors contributing to the increased susceptibility of these patients to invasive disease with Salmonella sp. are discussed as are the clinical features, surgical and antibiotic management and possible preventative measures.

Discitis in young children.

Discitis is uncommon in children and presents in different ways at different ages. It is most difficult to diagnose in the uncommunicative toddler of one to three years of age. We present 11 consecutive cases. The non-specific clinical features included refusal to walk (63%), back pain (27%), inability to flex the lower back (50%) and a loss of lumbar lordosis (40%). Laboratory tests were unhelpful and cultures of blood and disc tissue were negative. MRI reduces the diagnostic delay and may help to avoid the requirement for a biopsy. In 75% of cases it demonstrated a paravertebral inflammatory mass, which helped to determine the duration of the oral therapy given after initial intravenous antibiotics. At a mean follow-up of 21 months (10 to 40), all the spines were mobile and the patients free from pain. Radiological fusion occurred in 20% and was predictable after two years. At follow-up, MRI showed variable appearances: changes in the vertebral body usually resolved at 24 months and recovery of the disc was seen after 34 months.

Otitis media in children with vertically-acquired HIV infection: the Great Ormond Street Hospital experience.

Human immunodeficiency virus (HIV) infection continues to be a vexing problem in the pediatric population. Otitis media, a common entity in immunocompetent as well as immunocompromised children, is prevalent in pediatric patients with HIV infection. Recurrent infections and complications secondary to otitis media are also common in this population. The purpose of this review was to evaluate the records of a large group of children with HIV infection undergoing treatment for otitis media at a tertiary care center. Incidence of infections, severity of infections, and pathogens responsible were the key points of data collection in relation to each patient's HIV clinical and immunologic classification. We reviewed 72 patients with vertically-acquired HIV infection undergoing treatment at the Hospital for Sick Children, Great Ormond Street, London. All patients were born to HIV infected mothers of sub-Saharan African origin. A total of 32 (44.4%) of these children presented to our institution with one or more episodes of otitis media, six of whom suffered systemic complications secondary to middle ear pathology. Middle ear culture data, when available from actively draining ears, was similar to those of immunocompetent children in the general population. The most common complications were systemic bacteremia and recalcitrant infections requiring intravenous antibiotic therapy. Severity of immunosuppression was associated with higher incidence and severity of otitis media. Otitis media in an HIV infected child must be treated aggressively at its outset in an attempt to minimize possible complications. Administration of prophylactic antibiotics to these children may reduce the frequency of acute and chronic infections. Improvement in immunologic status using antiretrovirals or protease inhibitors is a primary goal in diminishing the severity of otitis media as well as other infections in these children.

Eczema herpeticum. Clinical and laboratory features.

Eczema herpeticum (EH) is a potentially life-threatening complication that may occur in children with atopic dermatitis. The clinical and laboratory features of EH as seen in 14 children are reported. The mean age of affected children was 34 months. A rapid viral diagnosis was made in 72 percent of patients. In one-third of patients there was a history of herpes labialis in one or other parent in the previous week. In 28 percent of the children, EH was initially thought to be an exacerbation or impetiginization of the underlying dermatitis. Eleven of 14 children were treated with acyclovir (intravenously in eight, orally in three). All patients recovered without sequelae.

High-performance liquid chromatographic determination of 2-furaldehyde and 5-hydroxymethyl-2-furaldehyde in fruit juices.

A method for the determination of 2-furaldehyde (F) and 5-hydroxymethyl-2-furaldehyde (HMF) in fruit juices by high-performance liquid chromatography (HPLC) is described. The method is based on the formation of the 2,4-dinitrophenylhydrazones of carbonyl compounds and subsequent separation of these derivatives. Derivatization is carried out by utilizing an acidic solution of 2,4-dinitrophenylhydrazine in acetonitrile. Precipitation of the derivatives of carbonyl compounds is thus avoided, and direct injection of the sample into the HPLC system is allowed. The procedure offers a high specificity and a detection limit of the order of 10(-8) mol/L. Recoveries of 95-98% are obtained from apple juice spiked at different levels with both analytes. The reproducibility (mean of six determinations) is +/- 2% for F and +/- 3% for HMF.

[Effects of therapy with bis-hemisuccinate of ursodeoxycholic acid bisodium salt in patients with chronic hepatitis]. / Effetto della terapia con bis-emisuccinato dell'acido ursodesossicolico sale bisodico in pazienti con epatiti croniche.

It has recently been shown that ursodeoxycholic acid administration improves liver function tests in patients with chronic liver diseases. Aim of the present study was to evaluate an ursodeoxycholic acid derivative (bis-hemisuccinate bisodic salt Ursodamor, Farmaceutici Damor, Napoli) in patients with chronic hepatitis. Forty patients (15 M, 25 F) with biopsy proven chronic liver disease participated to the study. Patients were randomly allocated to two treatment groups. Twenty patients (4 PBC, 11 CAH/CPH, 5 cirrhosis) received the ursodeoxycholic acid derivate at the dose of 600 mg/day, while 20 patients (1 PBC, 11 CAH/CPH, 8 cirrhosis) received a placebo. For both groups the treatment period was six months. ALT serum levels were significantly reduced in the treated group (from 84 +/- 14 to 62 +/- 14 p less than 0.0005) while no significant change was observed in the placebo group. In the treated group but not in the placebo group alkaline phosphatases and gamma-GT were also significantly reduced (from 268 +/- 56 to 160 +/- 23 p less than 0.0005 and from 79 +/- 21 to 45 +/- 10 p less than 0.0005). In conclusion, our results suggest that the administration of the ursodeoxycholic acid derivate, bis-hemisuccinate, bisodic salt, improves liver function tests in patients with chronic liver hepatitis. Similarly to ursodeoxycholic acid this new derivate probably interferes with bile acid pool composition by replacing the more detergent and probably more toxic endogenous bile acid.

Dual infection with atypical mycobacteria and Mycobacterium tuberculosis causing cervical lymphadenopathy in a child.

The most common presentation of mycobacterial infection encountered in otolaryngological practice is cervical lymphadenitis. We report a child with an unusual cause of cervical lymphadenopathy, i.e. dual tuberculous infections. This had clinical ramifications as, initially Mycobacterium avium-intracellulare was grown in culture and was resistant to standard anti-tuberculous agents, and hence treated with excision of the lymph node. However, the cultures from the excised lymph node grew out Mycobacterium tuberculosis that was sensitive to standard anti-tuberculous drugs. To our knowledge, no such presentation has been reported previously. We also review the literature on cervical lymphadenitis due to atypical mycobacteria and Mycobacterium tuberculosis, with particular emphasis on clinical presentation, diagnosis and management.