Prevalence of nucleic acid sequences specific for human parvoviruses, hepatitis A and hepatitis E viruses in coagulation factor concentrates.

BACKGROUND AND OBJECTIVES: Due to their high resistance to inactivation procedures, nonenveloped viruses such as parvovirus B19, human bocavirus (HBoV), human parvovirus 4 (PARV4), hepatitis A (HAV) and hepatitis E virus (HEV) pose a particular threat to blood products. Virus transmission to patients treated with blood products presents an additional burden to disease. We determined the frequency and the amount of nucleic acid specific for nonenveloped viruses in recently manufactured preparations of commercial coagulation factor concentrates. MATERIALS AND METHODS: At least three different batches of each of 13 different plasma-derived and recombinant coagulation factor products were tested for the presence and the amount of nucleic acid for parvovirus B19, HBoV, human parvovirus 4, hepatitis A virus and HEV by using quantitative polymerase chain reaction. RESULTS: Whereas none of the recombinant products tested positive for any of these viruses, parvovirus B19 DNA with amounts ranging between 2×10(1) and 1.3×10(3) genome equivalents/ml was detected in five plasma-derived products. In addition to parvovirus B19 genotype 1, genotypes 2 and 3 were observed in two batches of a factor VIII/von-Willebrand factor product. In two products (one factor VIII concentrate and one activated prothrombin complex concentrate), a combination of both genotypes 1 and 2 of parvovirus B19 was detected. CONCLUSION: The data show that nucleic acids from several relevant nonenveloped viruses are not found at detectable levels in coagulation factor concentrates. In some cases, parvovirus B19 DNA was detectable at low levels. Testing of the plasma pools for the full range of parvovirus genotypes is advocated for ensuring product safety.

Expression of the lipid transporters ABCA3 and ABCA1 is diminished in human breast cancer tissue.

ATP-binding cassette transporters ABCA3 and ABCA1 are related to a differentiated, lipid-secreting phenotype of type II pneumocytes. Since mammary gland epithelial cells also show pronounced lipid metabolism and secretion, we investigated the expression of these proteins in normal as well as in neoplastic breast tissue. Normal human breast tissue, breast cancer cell lines, and 162 tumor samples of patients with primary unilateral invasive breast cancer were analyzed for ABCA3 and ABCA1 protein expression by immunohistochemistry using tissue microarrays. Strong ABCA3 and ABCA1 expression was found in the inner layer of normal mammary gland epithelium. Concurrent cytoplasmic ABCA3 and ABCA1 immunoreactivity was found in 9 of 11 breast cancer cell lines. ABCA3 and ABCA1 were shown to be differentially expressed in human breast cancer. Loss of ABCA3 staining was significantly associated with positive nodal status and negative progesterone receptor expression. In multivariate analysis, diminished ABCA3 expression proved to be a significant, independent and adverse risk factor for tumor recurrence. ABCA1 expression was associated with positive lymph nodes, but not significantly associated with tumor recurrence or breast cancer-specific survival. ABCA3 and ABCA1 are strongly expressed in normal mammary gland epithelium. Decreased ABCA3 expression in breast cancer seems to be associated with poor prognosis.

Prevalence and clinical aspects of human bocavirus infection in children.

Human bocavirus (HBoV) was recently described as a new member of the Parvoviridae. In order to investigate the suggested association of HBoV with respiratory and gastric disease in infants and young children, sera of 357 paediatric patients hospitalized with infectious and non-infectious diseases were retrospectively analyzed for the presence of HBoV DNA and virus-specific antibodies using quantitative PCR and ELISA, respectively. HBoV seroprevalence was determined to range from 25% in infants younger than 1 year of age to 93% in children aged more than 3 years. Viral loads between 1 x 10(2) and 1.2 x 10(6) geq/mL were observed in 6.7% (20/297) of sera obtained preferentially from young children suffering from infectious diseases. HBoV genomes were furthermore detected in 5% (3/60) of sera collected from individuals with non-infectious illnesses. HBoV DNA was present most frequently in patients with respiratory disease (9.6%). Whereas only 5.2% of patients with upper respiratory tract disease were viraemic, HBoV DNA was found in 14.6% and 10.0% of patients with lower respiratory tract illness and pneumonia, respectively. Acute HBoV infections were also observed in 7.5% of patients with gastroenteritis and in one child with inflammatory bowel disease. None of 77 patients hospitalized for various other infectious diseases (e.g. rash, urinary tract infection, meningitis) displayed viraemia. In 60.9% and 47.8% of DNA-positive children, HBoV-specific IgM and IgG was observed, respectively. The present prospective study provides comprehensive data on the clinical association of acute HBoV infection with respiratory illness and on the seroprevalence of virus-specific antibodies in children.

Persistent parvovirus B19 infection detected by specific CD4+ T-cell responses in a patient with hepatitis and polyarthritis.

We, here, report the case of a parvovirus B19 infection in an immunocompetent male patient presenting with acute hepatitis and polyarthritis. To follow the course of infection, we used a previously established enzyme-linked immunosorbent spot assay (ELISPOT) technique to detect CD4+ T cells specific for viral proteins. Even though symptoms of arthritis and hepatitis resolved in the immunocompetent individual within a few weeks, viral DNA in serum and CD4+ T cells specific for the viral protein VP1 unique region were still detectable more than 6 month after the onset of symptoms, thus pointing to a persistent state of infection. On the basis of this observation, we hypothesize that the intensity of liver involvement correlates with the likelihood of developing persistent parvovirus B19 infection. The described ELISPOT technique to detect virus-specific CD4+ T cells provides an excellent tool to analyse the state of parvovirus B19 infection for future studies to test this hypothesis.

Localization of beta1-adrenergic receptors in the cochlea and the vestibular labyrinth.

Sympathetic activation in a "fight or flight reaction" may put the sensory systems for hearing and balance into a state of heightened alert via beta1-adrenergic receptors (beta1-AR). The aim of the present study was to localize beta1-AR in the gerbil inner ear by confocal immunocytochemistry, to characterize beta1-AR by Western immunoblots, and to identify beta1-AR pharmacologically by measurements of cAMP production. Staining for beta1-AR was found in strial marginal cells, inner and outer hair cells, outer sulcus, and spiral ganglia cells of the cochlea, as well as in dark, transitional and supporting cells of the vestibular labyrinth. Receptors were characterized in microdissected inner ear tissue fractions as 55 kDa non-glycosylated species and as 160 kDa high-mannose-glycosylated complexes. Pharmacological studies using isoproterenol, ICI-118551 and CGP-20712A demonstrated beta1-AR as the predominant adrenergic receptor in stria vascularis and organ of Corti. In conclusion, beta1-AR are present and functional in inner ear epithelial cells that are involved in K+ cycling and auditory transduction, as well as in neuronal cells that are involved in auditory transmission.

Functional beta2-adrenergic receptors are present in nonstrial tissues of the lateral wall in the gerbil cochlea.

Recently, we have demonstrated that functional beta1-adrenergic receptors are the dominant beta-adrenergic receptor subtype in the stria vascularis and that beta1-adrenergic receptors stimulate K+ secretion in strial marginal cells. The goal of the present study was to determine whether nonstrial tissues in the cochlear lateral wall contain beta-adrenergic receptors and if so which subtype is present. Pharmacological tools were used to identify receptors in functional studies where cAMP production was measured. Further, receptors were identified as transcripts by cloning and sequencing of reverse-transcriptase polymerase chain reaction (RT-PCR) products. Experiments were performed on gerbil nonstrial lateral wall tissues. Tissues stimulated with 10(-5) M isoproterenol produced 0.42 +/- 0.22 pmol cAMP per ear within 12 min (n = 14). The selective beta-adrenergic receptor agonist isoproterenol stimulated cAMP production with an EC50 of (2 +/- 3) x 10(-7) M (n = 7). Isoproterenol-stimulated cAMP production was inhibited by the beta2-adrenergic receptor antagonist ICI 118551 with an IC50 of (7 +/- 7) x 10(-6) M, which corresponds to an affinity constant of 1 x 10(-7) M (pK(DB) = 6.89 +/- 0.23, n = 3). Isoproterenol-stimulated cAMP production was not inhibited by the highly selective beta1-adrenergic receptor antagonist CGP 20712A. The IC50 and the affinity constant for CGP 20712A were estimated to be >3 x 10(-4) and >6 x 10(-6) M, respectively. RT-PCR of total RNA isolated from nonstrial lateral wall tissues using primers specific for beta1-, beta2- and beta3-adrenergic receptors revealed products of the predicted sizes for the beta1- and beta2- but not for the beta3-subtype. Sequence analysis confirmed that amplified cDNA fragments encoded gene-specific nucleotide sequences. These results demonstrate that nonstrial lateral wall tissues contain transcripts for beta1- and beta2- but not for beta3-adrenergic receptors and that the beta2-adrenergic receptor is the dominant functional receptor subtype. The cellular localization and function of the beta2-adrenergic receptors remains to be determined.

K+ secretion in strial marginal cells is stimulated via beta 1-adrenergic receptors but not via beta 2-adrenergic or vasopressin receptors.

Pharmacologic tools were used to identify receptors in functional studies by measuring either transepithelial current (I(sc)) in strial marginal cells (SMC) or cAMP production in stria vascularis (SV). Further, receptors were identified in SV as transcripts by cloning and sequencing of reverse-transcriptase polymerase chain reaction (RT-PCR) products. Experiments were performed using tissues isolated from gerbils unless specified otherwise. I(sc) under control conditions was 1090 +/- 21 microA/cm(2) (n = 213) in gerbil SMC and 2001 +/- 95 microA/cm(2) (n = 6) in murine SMC. Direct stimulation of adenylate cyclase with 10(-5) m forskolin but not with 10(-5) m 1,9-dideoxy-forskolin resulted in an increase in the I(sc) by a factor of 1.14 +/- 0.01 (n = 6). The vasopressin-receptor agonist 10(-8) m Arg(8)-vasopressin had no significant effect on I(sc) in gerbil and murine SMC. The beta-adrenergic agonists isoproterenol, norepinephrine and epinephrine stimulated I(sc) with an EC(50) of (6 +/- 2) x 10(-7) m (n = 28), (3 +/- 1) x 10(-6) m (n = 40) and (7 +/- 2) x 10(-6) m (n = 38), respectively. Isoproterenol stimulated cAMP production in SV with an EC(50) of (5 +/- 2) x 10(-7) m (n = 8). The beta-antagonist 10(-4) m propanolol completely inhibited 2 x 10(-5) m isoproterenol-induced stimulation of I(sc). The beta-antagonists atenolol, ICI118551 and CGP20712A inhibited isoproterenol-induced stimulation of I(sc) with a K(DB) of 1 x 10(-7) m (pK(DB) = 6.96 +/- 0.15, n = 14), 1 x 10(-7) m (pK(DB) = 7. 01 +/- 0.14, n = 15), 2 x 10(-9) m (pK(DB) = 8.73 +/- 0.13, n = 19), respectively. CGP20712A inhibited isoproterenol-induced cAMP production with a K(DB) of 1 x 10(-10) m (pK(DB) = 9.94 +/- 0.55, n = 9). RT-PCR of total RNA isolated from SV using primers specific for the beta(1)-, beta(2)- and beta(3)-adrenergic receptors revealed products of the predicted sizes for the beta(1)- and beta(2)- but not the beta(3)-adrenergic receptor. Sequence analysis confirmed that amplified cDNA fragments encoded gene-specific nucleotide sequences. These results demonstrate that K(+) secretion in SMC is under the control of beta(1)-adrenergic receptors but not beta(2)-adrenergic or vasopressin-receptors and that the beta(1)-subtype is the primary beta-adrenergic receptor in SV although SV contains transcripts for both beta(1)- and beta(2)-adrenergic receptors.