Detection of cytomegalovirus in urine samples by an enzyme-linked immunosorbent assay using a monoclonal antibody against the viral 150-kilodalton protein.

McKeating et al. (J.A. McKeating, P.D. Griffiths, and J.E. Grundy, J. Gen. Virol. 68:785-792, 1987; J. A. McKeating, J. E. Grundy, Z. Varghese, and P. D. Griffiths, J. Med. Virol. 18:341-348, 1986; J. A. McKeating, S. Stagno, P. R. Stirk, and P. D. Griffiths, J. Med. Virol. 16:367-373, 1985) reported previously that beta 2 microglobulin inhibits the detection of human cytomegalovirus (CMV) in urine specimens by an enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody against the glycoprotein of CMV. They postulated that beta 2 microglobulin binds to the viral glycoproteins and masks the antigenic determinants. We developed here an ELISA method for the detection of CMV in urine by using a monoclonal antibody against the viral 150-kDa protein to capture the viral antigen. This assay detected CMV both in culture medium and in urine specifically at concentrations higher than 10(3) PFU/ml and quantitatively at concentrations higher than 10(4) PFU/ml. The sensitivity of the ELISA increased about 10-fold when peroxidase-labeled F(ab')2 from goat anti-human immunoglobulin G was used as a secondary detecting antibody in combination with concentration of the virus in urine samples by ultracentrifugation. The inhibition of ELISA by beta 2 microglobulin was not observed in this ELISA system. When 56 urine specimens from renal transplant recipients were examined for CMV antigens, the ELISA system had a sensitivity of 78% and a specificity of 97%. The positive and negative predictive values of the assay were 95 and 86%, respectively. Furthermore, CMV antigens in urine were quantitated by the assay during the course of typical CMV disease of renal transplant recipient. These results suggest strongly that the measurement of CMV antigens in urine by our rapid and quantitative ELISA system provides very useful data for the monitoring of CMV infections in renal transplant recipients and making decisions about therapy.     

Light and electron microscopic analyses of immediate and late tissue damage caused by radiofrequency ablation in porcine liver

Radiofrequency ablation (RFA) is an effective procedure for localized hepatocellular carcinoma. Contrast-enhanced CT depicts the ablated area as a hypoattenuated area without hepatic blood flow; however, light microscopy does not show obvious necrosis in the ablated area. We evaluated liver tissue changes after RFA by light microscopy and electron microscopy. The normal livers of three anesthetized pigs were coagulated using RFA after laparotomy. The liver was examined immediately, and 1 week after operation by light and electron microscopy. After RFA, the liver parenchyma surrounding the needle electrode was brown in color and surrounded by a red marginal zone separate from the normal liver parenchyma. Hematoxylin-eosin staining of the central area did not show cell necrosis, and the structures of liver sinusoids, liver cell cord and the nuclei of hepatocytes were preserved. However, electron microscopic examination of tissue immediately after RFA showed destruction of mitochondria of hepatocytes and fixation of sinusoidal cells. One week later, there was a large quantity of debris in the enlarged sinusoids, in addition to irreversible destruction of hepatocyte organelles. RFA of the porcine liver causes hepatocyte damage. This damage was not evident by light microscopy but clearly identified by electron microscopy.     

Inhibition by K-252a, a new inhibitor of protein kinase, of nerve growth factor-induced neurite outgrowth of chick embryo dorsal root ganglion cells

The effect of K-252a, a new alkaloid-like kinase inhibitor from the culture broth of Nocardiopsis sp., on the action of nerve growth factor on normal nerve cells was examined. Nerve cells were isolated from the dorsal root ganglia of chick embryo by trituration without using digesting enzymes, and were seeded on collagen- or poly-L-lysine-coated plastic dishes containing serum-free medium. K-252a at 50-100 nM reversibly inhibited the formation of neurites by dorsal root ganglion cells elicited by the treatment with nerve growth factor.     

Effects of hypocapnia on respiratory timing and inspiratory activities of the superior laryngeal, hypoglossal, and phrenic nerves in the vagotomized rat

Effects of acute hypocapnia on respiratory timing (inspiratory and expiratory times (TI, TE) ) and on inspiratory activities of the efferent superior laryngeal (Xs1), hypoglossal (XII), and phrenic (Phr) nerves were studied in artificially ventilated vagotomized, and anesthetized rats. Hyperventilation induced a decrease in respiratory frequency exclusively due to prolongation of TE and resulted in expiratory apnea. Inspiratory activities of three nerves decreased with reduction in CO2 concentration of end-tidal gas (FETCO2), and disappeared simultaneously at a threshold FETCO2 for apnea. The decrease in the peak inspiratory activity by hypocapnia was larger in the XII than in the Phr or Xs1 nerve (XII greater than Phr greater than Xs1). The results suggest that the CO2 stimulus (mainly via a central chemosensor) plays an important role in the process of terminating expiration or of expiratory-inspiratory phase switching and that the responses of the XII or Xs1 motoneurons to variation in CO2 stimulus differ from that of the Phr motoneurons (or of the Phr driving medullary neurons). A possible functional significance of these observations is discussed.     

Large-scale screening of nasal swabs for Bacillus anthracis: descriptive summary and discussion of the National Institutes of Health's experience

In October 2001, a letter containing a large number of anthrax spores was sent through the Brentwood post office in Washington, D.C., to a United States Senate office on Capitol Hill, resulting in contamination in both places. Several thousand people who worked at these sites were screened for spore exposure by collecting nasal swab samples. We describe here a screening protocol which we, as a level A laboratory, used on very short notice to process a large number of specimens (3,936 swabs) in order to report preliminary results as quickly as possible. Six isolates from our screening met preliminary criteria for Bacillus anthracis identification and were referred for definitive testing. Although none of the isolates was later confirmed to be B. anthracis, we studied these isolates further to define their biochemical characteristics and 16S rRNA sequences. Four of the six isolates were identified as Bacillus megaterium, one was identified as Bacillus cereus, and one was an unidentifiable Bacillus sp. Our results suggest that large-scale nasal-swab screening for potential exposure to anthrax spores, particularly if not done immediately postexposure, may not be very effective for detecting B. anthracis but may detect a number of Bacillus spp. that are phenotypically very similar to B. anthracis.     

Human arylhydrocarbon receptor repressor (AHRR) gene: genomic structure and analysis of polymorphism in endometriosis

The diversity of biological effects resulting from exposure to dioxin may reflect the ability of this environmental pollutant to alter gene expression by binding to the arylhydrocarbon receptor (AHR) gene and related genes. AHR function may be regulated by structural variations in AHR itself, in the AHR repressor (AHRR), in the AHR nuclear translocator (ARNT), or in AHR target molecules such as cytochrome P-4501A1 (CYP1A1) and glutathione S-transferase. Analysis of the genomic organization of AHRR revealed an open reading frame consisting of a 2094-bp mRNA encoded by ten exons. We found one novel polymorphism, a substitution of Ala by Pro at codon 185 (GCC to CCC), in exon 5 of the AHRR gene; among 108 healthy unrelated Japanese women, genotypes Ala/Ala, Ala/Pro, and Pro/Pro were represented, respectively, by 20 (18.5%), 49 (45.4%), and 39 (36.1%) individuals. We did not detect previously published polymorphisms of ARNT (D511N) or the CYP1A1 promoter (G-469A and C-459T) in our subjects, suggesting that these polymorphisms are rare in the Japanese population. No association was found between uterine endometriosis and any polymorphisms in the AHRR, AHR, ARNT, or CYP1A1 genes analyzed in the present study. Received: January 24, 2001 / Accepted: March 1, 2001     

No allelic association between Parkinson's disease and dopamine D2, D3, and D4 receptor gene polymorphisms

Parkinson's disease is thought to be caused by a combination of unknown environmental, genetic, and degenerative factors. Evidence from necropsy brain samples and pharmacokinetics suggests involvement of dopamine receptors in the pathogenesis or pathophysiology of Parkinson's disease. Genetic association studies between Parkinson's disease and dopamine D2, D3 and D4 receptor gene polymorphisms were conducted. The polymorphism was examined in 71 patients with Parkinson's disease and 90 controls. There were no significant differences between two groups in allele frequencies at the D2, D3, and D4 dopamine receptor loci. Our findings do not support the hypothesis that susceptibility to Parkinson's disease is associated with the dopamine receptor polymorphisms examined. © 1994 Wiley-Liss, Inc.