Molecular and serological characterization of species B2 adenovirus strains isolated from children hospitalized with acute respiratory disease in Buenos Aires, Argentina

BACKGROUND

Between September 2000 and November 2005, approximately 10% of the retrospectively examined human adenovirus (HAdV)-positive pediatric cases of acute respiratory disease (ARD) requiring hospitalization at the Hospital Nacional de Pediatria Juan P. Garrahan in Buenos Aires, Argentina, were found to have a HAdV-B2 infection.

OBJECTIVE

To characterize genetically and antigenically the HAdV-B2 virus isolates.

STUDY DESIGN

Restriction enzyme analysis (REA), hexon and fiber gene sequencing and virus neutralization assays (VN) were carried out on 8 HAdV-B2 respiratory virus isolates.

RESULTS

REA showed that the 8 examined HAdV-B2 virus isolates were HAdV11, belonging to two genomic variants: HAdV11a and a BclI variant of HAdV11c which we designated 11c4. Molecular analysis of the hexon genes showed that both REA variants had a HAdV11-like hexon gene. Confirming previous reports, the 7 HAdV11a virus isolates were found to have HAdV14-like fiber genes and therefore are HAdV H11/F14. The fiber gene of the HAdV11c4 virus isolates most closely resembled that of various strains of HAdV7. In VN assays, the 4 tested HAdV11a strains were serotyped as HAdV11-14. The HAdV11c4 strain was serotyped as HAdV11 but also showed a weak but significant reactivity with antiserum to HAdV7. Compared with the other HAdV-positive cases in our study, infection with HAdV11 caused a similarly severe disease.

CONCLUSIONS

Our results provide evidence to the long term world-wide circulation of HAdV H11/F14 as a causative agent of ARD. Combined, our molecular and serology data support the rationale to base the molecular typing and designation of recombinant viruses on the sequences of the hexon and fiber genes.

Molecular epidemiology and clinical presentation of human adenovirus infections in Kansas City children

BACKGROUND

A significant increase in adenovirus detection among patients at the Children's Mercy Hospital, Kansas City was observed between June 2007 and January 2008.

OBJECTIVE

To molecularly characterize the human adenoviruses and describe their association with clinical illness in children.

STUDY DESIGN

One hundred adenovirus-positive specimens from 79 children were typed by hexon gene sequence typing method. Restriction enzyme analysis (REA) was performed on isolates of HAdV-3, -7 and -14 to identify genomic variants. Medical records were reviewed to understand the clinical illnesses associated with adenovirus serotypes and genome types.

RESULTS

The most prevalent HAdV serotypes were HAdV-3 (37%), HAdV-7 (25%), HAdV-1 (16%), HAdV-2 (8%). HAdV infection was common in children ≤3 years of age (71%) versus children >3 years (29%). Majority of the HAdV-infected children were hospitalized (78%); 22/79 (28%) stayed >3 days and 8/79 (10%) required intensive care unit stay. Hospitalization rates for HAdV-3 (36%) and HAdV-7 (25%) were comparable. REA data indicated that HAdV-3a2 was the predominant HAdV-3 genome type. Two novel genomic variants of HAdV-3 exhibiting unique BglII or BstEII profiles were identified in isolates from patients with bronchiolitis. All HAdV-7 and -14 isolates were identified as corresponding to genome types 7d2 and 14p1, respectively.

CONCLUSIONS

In Kansas City, we noticed an increase in the incidence of HAdV-7 (25%; n=24/98) infections compared to the previous two years (6%; n=6/107). Two new genomic variants of HAdV-3 appear to have emerged in our area and seem to be associated with lower respiratory tract infections in children.

Fatal disseminated adenovirus infection in a young adult with systemic lupus erythematosus

BACKGROUND

The use of corticosteroids and other immunosuppressive agents increases the risk of infection in patients with systemic lupus erythematosus (SLE). The role of human adenoviruses (HAdV) in the etiology of acute viral diseases in these patients is not known.

OBJECTIVES

Describe a case of acute fatal disseminated adenovirus infection in an SLE patient receiving immunosuppressive therapy.

STUDY DESIGN

Case report and detailed viral diagnosis by real time PCR and molecular typing of virus isolates by sequencing of hexon and fiber genes and restriction enzyme analysis of viral DNA.

RESULTS

HAdV was detected by real time PCR in multiple clinical specimens including respiratory, urine, plasma, synovial fluid, and cerebrospinal fluid. Amplification and sequence analysis of the hexon and fiber genes identified the virus as HAdV-7-like for both coding regions. Adenoviruses isolated from respiratory and urine specimens were identical and corresponded to genome type 7d2 by restriction enzyme analysis of viral DNA. The isolated strain encodes a unique fiber gene with a 6-nucleotide deletion corresponding to amino acid positions 250 and 251 in the knob region and not previously described for closely related genomic variants of HAdV-7.

CONCLUSIONS

Adenovirus detection should be included in the diagnostic testing to determine the infectious etiology of fever and/or respiratory symptoms in SLE patients.

Fatty acid and phorbol ester-mediated interference of mitogenic signaling via novel protein kinase C isoforms in pancreatic beta-cells (INS-1)

It is possible that activation of protein kinase C (PKC) isoforms by free fatty acids (FFA) plays a role in the failure of pancreatic beta-cell mass expansion to compensate for peripheral insulin resistance in the pathogenesis of type-2 diabetes. The effect of lipid moieties on activation of conventional (PKC-alpha and -beta1), novel (PKC-delta) and atypical (PKC-zeta) PKC isoforms was evaluated in an in vitro assay, using biotinylated neurogranin as a substrate. Oleoyl-Coenzyme A (CoA) and palmitoyl-CoA, but not unesterified FFA, significantly increased the activity of all PKC isoforms (P< or =0.05), particularly that for PKC-delta. It was found that FFA (0.4 mM oleate/complexed to 0.5% bovine serum albumin) inhibited IGF-I-induced activation of protein kinase B (PKB) in the pancreatic beta-cell line (INS-1), but this was alleviated in the presence of the general PKC inhibitor (Gö6850; 1 microM). To further investigate whether conventional or novel PKC isoforms adversely affect beta-cell proliferation, the effect of phorbol ester (phorbol 12-myristate 13-acetate; PMA)-mediated activation of these PKC isoforms on glucose/IGF-I-induced INS-1 cell mitogenesis, and insulin receptor substrate (IRS)-mediated signal transduction was investigated. PMA-mediated activation of PKC (100 nM; 4 h) reduced glucose/IGF-I mediated beta-cell mitogenesis (>50%; P< or =0.05), which was reversible by the general PKC inhibitor Gö6850 (1 microM), indicating an effect of PKC and not due to a non-specific PMA toxicity. PMA inhibited IGF-I-induced activation of PKB, correlating with inhibition of IGF-I-induced association of IRS-2 with the p85 regulatory subunit of phosphatidylinositol-3 kinase. However, in contrast, PMA activated the mitogen-activated protein kinases, Erk1/2. Titration inhibition analysis using PKC isoform inhibitors indicated that these PMA-induced effects were via novel PKC isoforms. Thus, FFA/PMA-induced activation of novel PKC isoforms can inhibit glucose/IGF-I-mediated beta-cell mitogenesis, in part by decreasing PKB activation, despite an upregulation of Erk1/2. Thus, activation of novel PKC isoforms by long-chain acyl-CoA may well contribute to decreasing beta-cell mass in the pathogenesis of type-2 diabetes, similar to their inhibition of insulin signal transduction which causes insulin resistance.

Differential activation of protein kinase B and p70(S6)K by glucose and insulin-like growth factor 1 in pancreatic beta-cells (INS-1)

It has been shown that IGF-1-induced pancreatic beta-cell proliferation is glucose-dependent; however, the mechanisms responsible for this glucose dependence are not known. Adenoviral mediated expression of constitutively active phosphatidylinositol 3-kinase (PI3K) in the pancreatic beta-cells, INS-1, suggested that PI3K was not necessary for glucose-induced beta-cell proliferation but was required for IGF-1-induced mitogenesis. Examination of the signaling components downstream of PI3K, 3-phosphoinositide-dependent kinase 1, protein kinase B (PKB), glycogen synthase kinase-3, and p70-kDa-S6-kinase (p70(S6K)), suggested that a major part of glucose-dependent beta-cell proliferation requires activation of mammalian target of rapamycin/p70(S6K), independent of phosphoinositide-dependent kinase 1/PKB activation. Adenoviral expression of the kinase-dead form of PKB in INS-1 cells decreased IGF-1-induced beta-cell proliferation. However, a surprisingly similar decrease was also observed in adenoviral wild type and constitutively active PKB-infected cells. Upon analysis of extracellular signal-regulated protein kinase 1 and 2 (ERK1/ERK2), an increase in ERK1/ERK2 phosphorylation activation by glucose and IGF-1 was observed in kinase-dead PKB-infected cells, but this phosphorylation activation was inhibited in the constitutively active PKB-infected cells. Hence, there is a requirement for the activation of both ERK1/ERK2 and mammalian target of rapamycin/p70(S6K) signal transduction pathways for a full commitment to glucose-induced pancreatic beta-cell mitogenesis. However, for IGF-1-induced activation, these pathways must be carefully balanced, because chronic activation of one (PI3K/PKB) can lead to dampening of the other (ERK1/2), reducing the mitogenic response.

mRNA translation in yeast during entry into stationary phase

The expression of some Saccharomyces cerevisiae genes is induced as cells enter stationary phase. Their mRNAs are translated during a period in the growth cycle when the translational apparatus is relatively inert, thereby raising the possibility that these mRNAs compete effectively for a limiting pool of translation factors. To test this idea, the translation of mRNAs carrying different 5'-leaders was compared during exponential growth and after entry into stationary phase upon glucose starvation. Closely related sets of lacZ mRNAs, carrying 5'-leaders from the PYK1, PGK1, RpL3, Rp29, HSP12, HSP26 or THI4 mRNAs, were studied. These mRNAs displayed differing translational efficiencies during exponential growth, but their relative translatabilities were not significantly affected by entry into stationary phase, indicating that they compete just as effectively under these conditions. Polysome analysis revealed that the wild-type PYK1, ACT1 and HSP26 mRNAs are all translated efficiently during stationary phase, when the translational apparatus is relatively inert. Also, significant levels of the translation initiation factors eIF-2alpha, eIF-4E and eIF-4A were maintained during the growth cycle. These data are consistent with the idea that, while translational activity decreases dramatically during entry into stationary phase, yeast cells maintain excess translational capacity under these conditions.

Automated entry of hospital infection surveillance data

OBJECTIVE

To assess the accuracy of an automated data entry system employing optical scanning technology and to provide an analysis of its costs as compared to manual data entry.

DESIGN

The accuracy and cost of automated data entry of 100 surgical-wound infection surveillance questionnaires was compared to manual entry.

SETTING

The Surgical Directorate, The Royal Hospitals, Belfast, Northern Ireland.

RESULTS

The use of optical scanning technology greatly improved the speed and accuracy of data entry. The time spent by the keyboard operator on data entry was reduced substantially. For each surgical-wound infection questionnaire automatically processed, there was a saving in clerical time equivalent to $0.63. The automated data entry process resulted in a 22-fold productivity increase compared to manual data entry with validation. After validation, an error rate of < 0.2 errors per 1,000 responses was detected in automatically entered data compared to a rate of 12.4 errors per 1,000 responses for manually entered data. The automated system, including validation, provided a seven-fold productivity increase compared to "quick-and-dirty" manual data entry without validation.

CONCLUSION

Hospital information technology systems may achieve total integration of data management, but realistically this would appear to be very much in the future. Until then, in view of the accuracy and substantial savings in time and money, we recommend the use of automated data entry technology. This system would be especially useful where data are transported from outlying hospitals to a central receiving center for collation and analysis.

The development of nerve-endings in the respiratory muscles of the sheep

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