The capability of porcine reproductive and respiratory syndrome virus (PRRSV) to be shed in semen for extended periods of time has been suggested to be a principal factor for viral transmission via insemination. In attempts to gain insights into the mechanism of PRRSV persistence in boars, tissue distribution and sites of viral infection were investigated by in situ hybridization (ISH) using digoxigenin-labeled RNA probe and the ISH results were compared with those of reverse transcription-nested polymerase chain reaction (RT-nested PCR). Animals were intranasally inoculated with 104 median tissue culture infectious dose of PRRSV VR-2332 and tissues collected at different times were examined. At day 7 postinfection, limited number of hybridization positive signals was observed in cells within or between seminiferous tubules in the testis sections while relatively abundant hybridization positive signals were observed in the brain stem and tracheobronchial lymph node. At later days of infection, hybridization positive signals were observed in cells within seminiferous tubules with much reduced frequency. Lack of agreement with the RT-nested PCR assay results in testis tissues obtained at days 14, 28, and 59 postinfection suggested that PRRSV infection in the testis may be extremely restricted, and may not necessarily constitute a major viral source in semen during extended periods of seminal shedding.
Animals ; Brain Stem/virology ; Endopeptidase K/metabolism ; *In Situ Hybridization ; Lymph Nodes/virology ; Male ; Microwaves ; Porcine Reproductive and Respiratory Syndrome/transmission/*virology ; Porcine respiratory and reproductive syndrome virus/*genetics/*isolation & purification ; RNA Probes ; Reverse Transcriptase Polymerase Chain Reaction ; Semen/virology ; Seminiferous Tubules/virology ; Sensitivity and Specificity ; Sexually Transmitted Diseases, Viral/transmission/veterinary/virology ; Swine/*virology ; Testis/virology

OBJECTIVETo understand clinicopathologic characteristics of hand-foot-and-mouth disease.

METHODSThe data of two autopsy cases with brainstem encephalitis caused by enterovirus type 71 infection were analyzed.

RESULTSThe age of the two patients was younger ( < or = 3 age). The clinical course was rapidly progressive, vesicular rashes were found in one case and the other case had no rashes. Both patients had clinical manifestations of central nervous system. Rapid progression to death were preceded by the development of pulmonary edema and hemorrhage. The results of the autopsy showed that the brain and brain stem were most severely involved and there were inflammation and necrosis. There were lung edema and hemorrhage. The myocardium and other organs were not infiltrated by inflammatory cells.

CONCLUSIONHand-foot- and-mouth disease with enterovirus type 71 infection often affected central nervous system, rapid progression to death was preceded by the development of brain stem encephalitis and pulmonary edema.

Brain Stem ; Cause of Death ; Child, Preschool ; Encephalitis, Viral ; pathology ; Enterovirus A, Human ; Female ; Hand, Foot and Mouth Disease ; virology ; Humans ; Infant ; Male ; Myocarditis ; virology

OBJECTIVE: To explore the mechanism that how human enterovirus 71 (EV71) invades the brainstem and how intercellular adhesion molecules-1 (ICAM-1) participates by analyzing the expression and distribution of human EV71, and ICAM-1 in brainstem of infants with brain stem encephalitis. METHODS: Twenty-two brainstem of infants with brain stem encephalitis were collected as the experimental group and 10 brainstems of fatal congenital heart disease were selected as the control group. The sections with perivascular cuffings were selected to observe EV71-VP1 expression by immunohistochemistry method and ICAM-1 expression was detected for the sections with EV71-VP1 positive expression. The staining image analysis and statistics analysis were performed. The experiment and control groups were compared. RESULTS: (1) EV71-VP1 positive cells in the experimental group were mainly astrocytes in brainstem with [dark]-brown particles, and the control group was negative. (2) ICAM-1 positive cells showed [dark]-brown. The expression in inflammatory cells (around blood vessels of brain stem and in glial nodules) and gliocytes increased. The results showed statistical difference comparing with control group (P < 0.05). CONCLUSION The brainstem encephalitis can be used to diagnose fatal EV71 infection in infants. EV71 can invade the brainstem via hematogenous route. ICAM-1 may play an important role in the pathogenic process.
Astrocytes/pathology* ; Brain Stem/virology* ; Case-Control Studies ; Encephalitis, Viral/virology* ; Enterovirus A, Human/metabolism* ; Female ; Hand, Foot and Mouth Disease/virology* ; Humans ; Immunohistochemistry ; Infant ; Intercellular Adhesion Molecule-1/metabolism* ; Male

OBJECTIVE: To understand the correlation of enterovirus 71 (EV71), P-selectin glycoprotein ligand-1 (PSGL-1), and scavenger receptor B2 (SCARB2) and to explore the possible pathway and mechanism of EV71 infection by observing the expression of EV71, PSGL-1 and SCARB2 in tissues of infants with brain stem encephalitis. METHODS: The organs and tissues of infants with EV71-VP1 positivity in their brain stems were chosen. Expression and distribution of EV71-VP1, PSGL-1, and SCARB2 were detected and compared by immunohistochemistry. RESULTS: Strong staining of EV71 -VP1 was observed in the neuron, glial cells, the inflammatory cells of perivascular cuffing, parietal cells of the gastric fundus gland while alveolar macrophages, intestinal gland epithelium cells, mucosa lymphoid nodule and lymphocyte of palatine tonsil showed moderate staining and weak staining were displayed in mesenteric lymph nodes and lymphocyte of spleen. PSGL-1 expression was detected in parietal cells of the gastric fundus gland, tonsillar crypt squamous epithelium, alveolar macrophages and leukocytes in each tissue. SCARB2 expression was observed in all the above tissues except the intestines and spleen. CONCLUSION The distribution of EV71 correlates with SCARB2 expression. SCARB2 plays an important role in virus infection and replication. Stomach may be an important site for EV71 replication.
Brain Stem/virology* ; Encephalitis, Viral/virology* ; Enterovirus A, Human/metabolism* ; Enterovirus Infections/virology* ; Humans ; Immunohistochemistry ; Infant ; Leukocytes ; Lysosome-Associated Membrane Glycoproteins ; Membrane Glycoproteins/metabolism* ; Receptors, Scavenger/metabolism* ; Receptors, Virus/metabolism*

Porcine reproductive and respiratory syndrome virus (PRRSV) RNA load in sera and tissues during acute phase of infection was evaluated using a PCR- based quantitative assay. More than 80% of infected pigs (21/25) showed the peak level of viral RNA concentrations in serum (up to 8.6 x 108 copies/ml) at day 5 postinfection (PI), and started to clear the virus from the systemic circulation thereafter. Regression analysis using the viral RNA concentrations in sera obtained from days 5 to 14 PI showed that the viral RNA was cleared at the rate of 0.37 log reduction in the number of PRRSV RNA copies per day. It was estimated to be day 27 PI when the viral RNA in the serum of infected pigs becomes undetectable. When correlation analysis was performed between the systemic clearance rate and viral RNA concentrations in tissues of 9 infected pigs obtained at day 14 PI, moderately strong negative correlation was observed in the thymus (r = - 0.62) and brain stem (r = - 0.48), suggesting the capability of host animal to clear PRRSV from the systemic circulation appears to be related to the viral activity in the thymus and brain stem.
Animals ; Brain Stem/virology ; Eye/virology ; Female ; Logistic Models ; Lymphoid Tissue/virology ; Male ; Porcine Reproductive and Respiratory Syndrome/blood/*virology ; Porcine respiratory and reproductive syndrome virus/*genetics/*isolation & purification ; RNA, Viral/*analysis ; Reference Standards ; Reverse Transcriptase Polymerase Chain Reaction ; Swine/*virology ; Time Factors ; *Viral Load ; Viremia/veterinary/virology

OBJECTIVEHuman cytomegalovirus (HCMV) is a ubiquitous human-specific DNA virus and is the main cause of congenital virus infection worldwide. Although 90% of the congenitally infected infants are clinically asymptomatic at birth, evidences show that these infants are at risk for audiologic, neurologic, and developmental sequelae. The aim of this study was to evaluate the outcome of children with asymptomatic congenital human cytomegalovirus infection identified from a cohort of newborn infants screened for congenital HCMV infection compared with matched uninfected control subjects.

METHODSBetween July 2003 and July 2005, eligible hospitalized infants were recruited into the cohort. Serum was collected within two weeks of birth and transported to the laboratory within 24 hours, and stored at -20 degrees C. Then Real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) for the presence of HCMV DNA was used as a screening tool for the detection of congenital cytomegalovirus infection. Asymptomatic congenital HCMV infection (ACCMV) was defined as detection of HCMV during the first 2 weeks of life in the absence of any abnormal signs, symptoms, or laboratory findings. The study enrolled 41 siblings with asymptomatic congenital HCMV infection and 21 children whose neonatal screening for congenital HCMV infection showed negative results. Then they were followed up prospectively for the first years of life. A pediatric assessment, including neonatal behavioral neurological assessment (NBNA) was performed at neonatal period by a qualified pediatrician, at which time the CMV status of the infants was not yet known. At one year of age other standardised clinical evaluations were performed by the pediatrician. The Bayley scale of infant development were used to determine the intellectual and neurological development deficits, and the age-adequate neurological examinations based on the criteria by Amiel-Tison to evaluate the general movements for neurological development. Hearing screening were completed for all children to determine their hearing status. Auditory brain-stem response (ABR) and distortion product otoacoustic emission (DPOAE) have been used to accurately diagnose moderate to profound congenital sensorineural hearing loss.

RESULTThere was no significant difference between the mean NBNA score of HCMV group (38.8 +/- 2.75) and the control group (38.5 +/- 2.29) (t = 0.98, P > 0.05). Significant difference was found between the occurrence of hearing loss in infants born with asymptomatic congenital HCMV infection compared with the control group. Audiologic abnormalities (sensorineural hearing loss, SNHL) were present in 5 of 23 congenitally infected children, however, no hearing abnormalities were detected in uninfected children (chi2 = 6.94, P < 0.01). The mean Bayley score of HCMV group (MDI 106.86 +/- 10.24 and PDI 108.45 +/- 18.25) and the control group (MDI 107.49 +/- 19.31 and PDI 107.19 +/- 10.98) did not differ significantly (t = 0.33, P > 0.05, t = 0.35, P > 0.05). Otherwise, there was no significant difference in 52 Amiel-Tison neurological scale between the two groups.

CONCLUSIONThese data suggest that asymptomatic congenital cytomegalovirus infection may be associated with a broad range of audiologic differences in early infancy. Continued monitoring of their hearing status in the first years of life is necessary in these children because further progression of hearing loss is possible. However, asymptomatic congenital HCMV infection is not associated with abnormalities in growth, or neurodevelopmental deficits.

Case-Control Studies ; Child Development ; Cytomegalovirus ; Cytomegalovirus Infections ; congenital ; virology ; Evoked Potentials, Auditory, Brain Stem ; Female ; Humans ; Infant ; Infant, Newborn ; Longitudinal Studies ; Male ; Neonatal Screening

Acyclovir ; therapeutic use ; Anti-Inflammatory Agents ; therapeutic use ; Antiviral Agents ; therapeutic use ; Brain Stem ; pathology ; virology ; Encephalitis ; complications ; diagnosis ; drug therapy ; virology ; Herpes Zoster ; complications ; diagnosis ; drug therapy ; virology ; Herpes Zoster Oticus ; diagnosis ; drug therapy ; etiology ; virology ; Humans ; Male ; Methylprednisolone ; therapeutic use ; Middle Aged

OBJECTIVETo study the clinicopathologic features of fatal enterovirus 71 (EV71) infection.

METHODSAutopsy was performed in 5 neonates died of EV71 infection. Tissue samples from major organs were collected, formalin-fixed and examined under light microscopy. Immunohistochemical study was carried out in selected examples.

RESULTSFour of the 5 cases showed predominant changes in central nervous system, with encephalitis and encephalomyelitis identified mainly in brainstem and upper cervical spinal cord. Histologic findings included neuronal degeneration and necrosis, neuronophagia, perivascular cuffing and diffuse or nodular hyperplasia of macrophages/microglia. Cerebral edema, brain herniation and aseptic meningitis were also noted. The lungs showed mainly pulmonary congestion, neurogenic pulmonary edema and focal hemorrhage. There were minimal changes in the intestinal epithelium. The intestinal lymphoid tissue however was hyperplastic and associated with apoptosis of follicular center cells. The remaining case had cerebral edema and mild meningitis. The lung alveolar septa were thickened with lymphocytic infiltrates. Some alveolar cells were hyperplastic and associated with diffuse hyaline membrane formation. No specific abnormalities were identified in gastrointestinal tract. In all the 5 cases studied, there was enlargement of lung hilar and mesenteric lymph nodes, coupled with apoptosis of follicular center cells. In general, no significant pathologic changes were demonstrated in heart, liver and kidneys.

CONCLUSIONSIn fatal EV71 infection, the major pathologic changes lie in the central nervous system. The pulmonary lesions are mainly secondary in nature. The usual cause of death is cerebral edema complicated by brain herniation and pulmonary edema. It is also noteworthy that some cases show only lung damages, without classic neurologic changes.

Autopsy ; Brain Edema ; etiology ; pathology ; Brain Stem ; pathology ; Child, Preschool ; Encephalitis, Viral ; etiology ; pathology ; Encephalomyelitis ; etiology ; pathology ; Enterovirus A, Human ; isolation & purification ; Enterovirus Infections ; complications ; pathology ; virology ; Female ; Humans ; Infant ; Male ; Pulmonary Edema ; etiology ; pathology ; Spinal Cord ; pathology

OBJECTIVETo determine the relationship between viral burden in urine and hearing loss in neonates with cytomegalovirus (CMV) infection.

METHODSTwenty-two neonates with CMV infection between April 2006 and January 2010 were enrolled. Their viral burden in urine and hearing loss information were studied. The receiver operating characteristic curve (ROC) was constructed and the cutoff was determined based on their medical information. The hearing levels were evaluated by brain stem auditory evoked potential (BAEP) during the age of 3 to 6 months in 20 patients.

RESULTSThe viral burden in urine in neonates with abnormal BAEP was higher than that in neonates with normal BAEP (5.06 ± 1.50 vs 3.73 ± 0.86, P<0.05). Hearing loss was predicted with a sensitivity of 0.545 and a specificity of 1.0 by using ROC at the cutoff point of 5.1 which were defined after logarithmic conversion at 1.27×10(5) copies/mL of CMV burden in urine. The incidence of hearing loss during the age of 3 to 6 months was strikingly higher in high viral burden group than that in low viral load group (P<0.05).

CONCLUSIONSThe viral burden in urine can predict the possibility of hearing loss in neonates with CMV infection. Hearing loss is likely to be developed when viral burden in urine ≥1.27×10(5) copies/mL in neonates with CMV infection.

Cytomegalovirus ; isolation & purification ; Cytomegalovirus Infections ; complications ; DNA, Viral ; urine ; Evoked Potentials, Auditory, Brain Stem ; Female ; Follow-Up Studies ; Hearing Loss ; etiology ; virology ; Humans ; Infant ; Infant, Newborn ; Male ; Viral Load

OBJECTIVECytomegalovirus (CMV) is the leading infectious cause of congenital anomalies of the central nervous system caused by intrauterine infection. However, the exact pathogenesis of these brain abnormalities has not been fully elucidated. It has been reported that periependymitis, periventricular necrosis and calcification are the most frequent findings in the brains of congenital CMV infection. Because a number of multipotential neural stem cells (NSCs) have been identified from ventricular zone, it is possible that NSCs in this area are primary targets for viral infection, which seems to be primarily responsible for the generation of the brain abnormalities. Therefore, the objective of the present study was to investigate the effect and mechanism of murine cytomegalovirus (MCMV) infection on neural stem cells' differentiation in vitro and its role in the mechanisms of brain abnormalities caused by congenital cytomegalovirus infection.

METHODSNSCs were prepared from fetal BALB/c mouse and were infected with recombinant MCMV RM461 inserted with a report gene LacZ at 1 multiplicity of infection (MOI = 1). The effect of MCMV infection on neural stem cells' differentiation was observed by detecting the ratio of nestin, GFAP and NSE positive cells with immunohistochemistry and flow cytometry on day 2 postinfection. The effects of MCMV infection on gene expression of Wnt-1 and neurogenin 1 (Ngn1) related to neural differentiation were detected by RT-PCR.

RESULTSNSCs isolated from embryonic mouse brains strongly expressed nestin, a specific marker of NSCs and had the capacity to differentiate into NF-200 and NSE positive neurons or GFAP positive astrocytes. At MOI = 1, the results of flow cytometry assay showed that nestin positive cells' proportion in the infection group [(62.2 +/- 1.8)%] was higher than that in the normal group [(37.2 +/- 2.4)%] (t = 4.62, P < 0.01). At the same time, the rates of GFAP and NSE positive cells' in the infection group were significantly lower than those in the normal group (P < 0.01). The scanning densities of Wnt-1 was 0.14 +/- 0.03 in the infection group while 0.32 +/- 0.04 in the control group (t = 7.21, P < 0.01). The scanning densities of Ngn1 were 0.09 +/- 0.01 and 0.21 +/- 0.02 in the two groups (t = 10.7, P < 0.01).

CONCLUSIONSThese results suggest that MCMV infection could inhibit neuronal differentiation, which may be primary causes of disorders of brain development in congenital CMV infection. The decreased expression of Wnt-1 and Ngn1 may be involved in the inhibitory effect of murine cytomegalovirus infection on neural stem cells' differentiation, which may lead to a new strategy for preventing and treating brain abnormalities caused by CMV infection through regulating these two signal pathways.

Animals ; Astrocytes ; Basic Helix-Loop-Helix Transcription Factors ; metabolism ; Brain ; cytology ; Carrier Proteins ; metabolism ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Cytomegalovirus Infections ; congenital ; Embryo, Mammalian ; cytology ; Female ; Glial Fibrillary Acidic Protein ; metabolism ; Immunohistochemistry ; Intermediate Filament Proteins ; genetics ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Multipotent Stem Cells ; metabolism ; virology ; Muromegalovirus ; Nerve Tissue Proteins ; genetics ; metabolism ; Nestin ; Neurons ; Pregnancy ; Reverse Transcriptase Polymerase Chain Reaction ; Wnt1 Protein ; genetics ; metabolism