Peripheral Blood Leukocytes And Serum Nested Polymerase Chain Reaction Are Complementary Methods For Monitoring Active Cytomegalovirus Infection In Transplant Patients.

Human cytomegalovirus is an important cause of morbidity and mortality in immunocompromised patients. Qualitative polymerase chain reaction (PCR) has proven to be a sensitive and effective technique in defining active cytomegalovirus infection, in addition to having low cost and being a useful test for situations in which there is no need for quantification. Real-time PCR has the advantage of quantification; however, the high cost of this methodology makes it impractical for routine use. To apply a nested PCR assay to serum (sPCR) and to evaluate its efficiency to diagnose active cytomegalovirus infection compared with PCR of peripheral blood leukocytes (L-PCR). Samples of 37 patients were prospectively evaluated. An internal control was created and applied to sPCR to exclude false-negative results. In total, 21 patients (57%) developed active cytomegalovirus infection. After analyzing the two methods for the diagnosis of active infection, higher sensitivity and negative predictive value of the L-PCR versus sPCR (100% versus 62%), and higher specificity and positive predictive value of sPCR versus L-PCR (81% versus 50% and 72%, respectively) were observed. Discordant results were observed in 11 patients who were L-PCR-positive but sPCR-negative for active cytomegalovirus infection, five of whom developed clinical symptoms of cytomegalovirus. Clinical symptoms were observed in 14 patients, 12 of whom were diagnosed with active infection by nested L-PCR (P=0.007) and seven by nested sPCR (P=0.02). Higher specificity and a positive predictive value for sPCR were observed. Nested L-PCR and sPCR were considered to be complementary methods for the diagnosis and management of symptomatic cytomegalovirus infection.24e69-7

Lutzomyia umbratilis, the Main Vector of Leishmania guyanensis, Represents a Novel Species Complex?

BACKGROUND: Lutzomyia umbratilis is an important Leishmania guyanensis vector in South America. Previous studies have suggested differences in the vector competence between L. umbratilis populations situated on opposite banks of the Amazonas and Negro Rivers in the central Amazonian Brazil region, likely indicating a species complex. However, few studies have been performed on these populations and the taxonomic status of L. umbratilis remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Phylogeographic structure was estimated for six L. umbratilis samples from the central Amazonian region in Brazil by analyzing mtDNA using 1181 bp of the COI gene to assess whether the populations on opposite banks of these rivers consist of incipient or distinct species. The genetic diversity was fairly high and the results revealed two distinct clades ( = lineages) with 1% sequence divergence. Clade I consisted of four samples from the left bank of the Amazonas and Negro Rivers, whereas clade II comprised two samples from the right bank of Negro River. No haplotypes were shared between samples of two clades. Samples within clades exhibited low to moderate genetic differentiation (F(ST) = -0.0390-0.1841), whereas samples between clades exhibited very high differentiation (F(ST) = 0.7100-0.8497) and fixed differences. These lineages have diverged approximately 0.22 Mya in the middle Pleistocene. Demographic expansion was detected for the lineages I and II approximately 30,448 and 15,859 years ago, respectively, in the late Pleistocene. CONCLUSIONS/SIGNIFICANCE: The two genetic lineages may represent an advanced speciation stage suggestive of incipient or distinct species within L. umbratilis. These findings suggest that the Amazonas and Negro Rivers may be acting as effective barriers, thus preventing gene flow between populations on opposite sides. Such findings have important implications for epidemiological studies, especially those related to vector competence and anthropophily, and for vector control strategies. In addition, L. umbratilis represents an interesting example in speciation studies

The expansion field: The value of H_0

Any calibration of the present value of the Hubble constant requires recession velocities and distances of galaxies. While the conversion of observed velocities into true recession velocities has only a small effect on the result, the derivation of unbiased distances which rest on a solid zero point and cover a useful range of about 4-30 Mpc is crucial. A list of 279 such galaxy distances within v<2000 km/s is given which are derived from the tip of the red-giant branch (TRGB), from Cepheids, and from supernovae of type Ia (SNe Ia). Their random errors are not more than 0.15 mag as shown by intercomparison. They trace a linear expansion field within narrow margins from v=250 to at least 2000 km/s. Additional 62 distant SNe Ia confirm the linearity to at least 20,000 km/s. The dispersion about the Hubble line is dominated by random peculiar velocities, amounting locally to <100 km/s but increasing outwards. Due to the linearity of the expansion field the Hubble constant H_0 can be found at any distance >4.5 Mpc. RR Lyr star-calibrated TRGB distances of 78 galaxies above this limit give H_0=63.0+/-1.6 at an effective distance of 6 Mpc. They compensate the effect of peculiar motions by their large number. Support for this result comes from 28 independently calibrated Cepheids that give H_0=63.4+/-1.7 at 15 Mpc. This agrees also with the large-scale value of H_0=61.2+/-0.5 from the distant, Cepheid-calibrated SNe Ia. A mean value of H_0=62.3+/-1.3 is adopted. Because the value depends on two independent zero points of the distance scale its systematic error is estimated to be 6%. Typical errors of H_0 come from the use of a universal, yet unjustified P-L relation of Cepheids, the neglect of selection bias in magnitude-limited samples, or they are inherent to the adopted models.Comment: 44 pages, 4 figures, 6 tables, accepted for publication in the Astronony and Astrophysics Review 15

Genotyping of human cytomegalovirus using non-radioactive single-strand conformation polymorphism (SSCP) analysis

Genetic variation in the glycoprotein B (gB) gene may play a role in human cytomegaloviruses (HCMVs) pathogenesis. Using restriction analysis of the gB gene product (PCR-RFLP), amplified by the nested polymerase chain reaction, the HCMV strains can be compared and classified into at least four HCMV groups. PCR single-strand conformation polymorphism (PCR-SSCP) is one of the techniques used to identify a mutant sequence or a polymorphism in a known gene. SSCP analysis has the advantage over RFLP analysis on detection of DNA polymorphisms and point mutations at a variety of positions in DNA fragments. However, the original SSCP protocols using the incorporation of radioactive label and polyacrylamide gel electrophoresis for detection are labour intensive and time-consuming. A simplified SSCP protocol is described to identify HCMV strains and the gB genotype, allowing the detection of sequence variations not residing in the endonuclease recognition sites. (C) 2003 Elsevier Science B.V. All rights reserved.1101252

Correlation of cytomegalovirus and human herpesvirus 7 with CD3+ and CD3+CD4+ cells in chronic periodontitis patients

Thomasini RL, Bonon SH, Durante P, Costa SCB. Correlation of cytomegalovirus and human herpesvirus 7 with CD3 + and CD3 + CD4 + cells in chronic periodontitis patients. J Periodont Res 2012; 47: 114120. (C) 2011 John Wiley & Sons A/S47111412

Cytomegalovirus infection as cause of severe thrombocytopenia in a nonimmunosuppressed patient

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