Abnormal Blood Coagulation and Kidney Damage in Aged Hamsters Infected with Severe Acute Respiratory Syndrome Coronavirus 2.

Systemic symptoms have often been observed in patients with coronavirus disease 2019 (COVID-19) in addition to pneumonia, however, the details are still unclear due to the lack of an appropriate animal model. In this study, we investigated and compared blood coagulation abnormalities and tissue damage between male Syrian hamsters of 9 (young) and over 36 (aged) weeks old after intranasal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite similar levels of viral replication and inflammatory responses in the lungs of both age groups, aged but not young hamsters showed significant prolongation of prothrombin time and prominent acute kidney damage. Moreover, aged hamsters demonstrated increased intravascular coagulation time-dependently in the lungs, suggesting that consumption of coagulation factors causes prothrombin time prolongation. Furthermore, proximal urinary tract damage and mesangial matrix expansion were observed in the kidneys of the aged hamsters at early and later disease stages, respectively. Given that the severity and mortality of COVID-19 are higher in elderly human patients, the effect of aging on pathogenesis needs to be understood and should be considered for the selection of animal models. We, thus, propose that the aged hamster is a good small animal model for COVID-19 research.

Discriminating between JCPyV and BKPyV in Urinary Virome Data Sets.

Polyomaviruses are abundant in the human body. The polyomaviruses JC virus (JCPyV) and BK virus (BKPyV) are common viruses in the human urinary tract. Prior studies have estimated that JCPyV infects between 20 and 80% of adults and that BKPyV infects between 65 and 90% of individuals by age 10. However, these two viruses encode for the same six genes and share 75% nucleotide sequence identity across their genomes. While prior urinary virome studies have repeatedly reported the presence of JCPyV, we were interested in seeing how JCPyV prevalence compares to BKPyV. We retrieved all publicly available shotgun metagenomic sequencing reads from urinary microbiome and virome studies (n = 165). While one third of the data sets produced hits to JCPyV, upon further investigation were we able to determine that the majority of these were in fact BKPyV. This distinction was made by specifically mining for JCPyV and BKPyV and considering uniform coverage across the genome. This approach provides confidence in taxon calls, even between closely related viruses with significant sequence similarity.

Factores de riesgo para infección del tracto urinario por microorganismos productores de betalactamasas de espectro extendido en niños en Huancayo, Perú / Risk factors for urinary tract infection by microorganisms producing extended spectrum beta-lactamase in children of Huancayo, Peru

Introducción: La infección del tracto urinario en los niños es una de las infecciones bacterianas más frecuentes con una alta tasa de recurrencia. Objetivo: Determinar los factores de riesgo para infección del tracto urinario adquirida en la comunidad por microorganismos productores de betalactamasas de espectro extendido en niños en Huancayo, Perú. Métodos: Estudio de tipo analítico con diseño de casos y controles. Se estudiaron 220 niños entre el mes de nacido hasta 13 años de edad, ingresados en el hospital nacional Ramiro Priale Priale con el diagnóstico de infección del tracto urinario durante el año 2019. Se distribuyeron en dos grupos (40 casos y 80 controles). Para cada paciente se llenó un cuestionario con las variables de interés y se realizó la comparación entre los grupos. Se realizó el análisis multivariado considerando significativo un valor de p< 0,05. Resultados: La frecuencia de infección del tracto urinario causada por microorganismos productores de betalactamasas de espectro extendido es de 18,18 por ciento. En los casos la edad predominante está entre 1 y 3 años con 42,5 por ciento, sexo femenino con 62,5 por ciento, la bacteria predominante es: Escherichia coli en 85,0 por ciento. Durante el análisis multivariado la presencia de infección del tracto urinario complicada tuvo OR 18,62 y p= 0,000 y la recurrente OR 12,98 y p= 0,004, ambas estadísticamente significativas para el desenlace de esta infección en los niños. Conclusión: Los factores de riesgo para infección del tracto urinario adquirida en la comunidad por microorganismos productores de betalactamasas de espectro extendido en niños son: infección del tracto urinario complicada y la recurrente(AU)

Introduction: Urinary tract infection in children is one of the most frequent bacterial infections with a high rate of recurrence. Objective: Determine the risk factors for community-acquired urinary tract infection by microorganisms producing extended-spectrum beta-lactamases in children of Huancayo, Peru. Methods: Analytical study with case-control design. 220 children from one month to 13 years of age were studied, whom were admitted to Ramiro Priale Priale National Hospital with the diagnosis of urinary tract infection during the year 2019. They were distributed in two groups (40 cases and 80 controls). For each patient, a questionnaire was completed with the variables of interest, and the comparison between the groups was made. The multivariate analysis was performed considering significant a value of p< 0.05. Results: The frequency of urinary tract infection caused by microorganisms producing extended-spectrum beta-lactamases is 18.18 percent. In the cases, the predominant age is between 1 and 3 years with 42.5 percent, female sex with 62.5 percent, the predominant bacterium is: Escherichia coli in 85.0 percent. During the multivariate analysis, the presence of complicated urinary tract infection had OR 18.62 and p= 0.000 and recurrent OR 12.98 and p= 0.004, both statistically significant for the outcome of this infection in children. Conclusion: The risk factors for community-acquired urinary tract infection by microorganisms producing extended-spectrum beta-lactamases in children are complicated and recurrent urinary tract infections(AU)

Parámetros diagnósticos en los lactantes con sospecha de infección del tracto urinario / Diagnostic parameters in infants with suspected urinary tract infection

Introducción: La sintomatología de la infección del tracto urinario es variable en la edad pediátrica, por ende, se presentan cuadros clínicos típicos y atípicos diversos debido a múltiples factores estudiados y definidos, que ofrecen dificultad para la confirmación diagnóstica. Objetivo: Identificar la utilidad de los parámetros diagnósticos de la infección urinaria. Métodos: Estudio observacional, analítico, de caso y controles, en lactantes ingresados con sospecha de infección urinaria en el Hospital Pediátrico Universitario Octavio de la Concepción y de la Pedraja admitidos en el servicio de clínicas pediátricas. El universo fueron los lactantes con sospecha de infección del tracto urinario y la muestra fue de 191 pacientes que cumplieron con los criterios de inclusión. Las variables utilizadas fueron la edad, el sexo, signos y síntomas, factores clínicos, formas clínicas, parámetros microbiológicos, parámetros clínicos según presencia de criterios de Rochester y escalas de evaluación para infección bacteriana y los parámetros de laboratorio. Resultados: Las variables clínicas más importantes asociadas a una infección urinaria fueron la edad menor de tres meses, la fiebre y el no disfrute de la lactancia materna, mientras que las de laboratorio fueron anemia, leucocitosis, neutrofilia y eritrosedimentación elevada. Conclusiones: Se identifica un conjunto de parámetros clínicos y estudios de laboratorio útiles en la atención médica del niño con infección urinaria. La forma de presentación febril es la característica especial de la enfermedad y las investigaciones hematológicas y del sedimento urinario son fuentes de apoyo diagnóstico(AU)

Introduction: The symptomatology of urinary tract infection is variable in pediatric ages, therefore, there are typical and atypical clinical pictures due to multiple factors studied and defined but that offer difficulty for diagnostic confirmation. Objective: Identify the usefulness of the diagnostic parameters of urinary tract infection. Methods: Observational, analytical, case-control study in infants admitted with suspected urinary tract infection at Octavio de la Concepción y de la Pedraja University Pediatric Hospital and admitted to the pediatric clinic service. The total sample were infants with suspected urinary tract infection and the sample was 191 patients who met the inclusion criteria. The variables used were age, sex, signs and symptoms, clinical factors, clinical forms, microbiological parameters, clinical parameters according to the presence of Rochester criteria and evaluation scales for bacterial infection and laboratory parameters. Results: The most important clinical variables associated with a urinary tract infection were: age less than three months, fever and non-enjoyment of breastfeeding; while laboratory variables were: anemia, leukocytosis, neutrophilia and elevated erythrosedimentation. Conclusions: A set of clinical parameters and laboratory studies useful in the medical care of children with urinary tract infection are identified. The form of febrile presentation is the specific characteristic of the disease and hematological and urinary sediment investigations are sources of diagnostic support(AU)

Efectividad del tratamiento quimioprofiláctico sobre las recurrencias en la infección del tracto urinario / Effectiveness of chemoprophylactic treatment in recurrences of urinary tract infection

Introducción: Los síntomas urinarios constituyen el motivo de consulta pediátrica más frecuente en relación con el aparato urinario durante cualquier época del año y a cualquier edad. Los argumentos para el uso o no de la quimioprofilaxis para evitar las recurrencias, son variables. Objetivo: Verificar la efectividad de la quimioprofilaxis para prevenir las recurrencias en la infección del tracto urinario en niños de 1 a 24 meses. Métodos: Se realizó un cuasi-experimento conformado por 58 pacientes que ingresaron en el Hospital Pediátrico de Holguín que cumplieron con los criterios de inclusión. Las variables de estudio fueron: número de recurrencias, momento de aparición durante la observación, presencia de recurrencia, quimioprofilaxis, tipo de quimioprofilaxis, edad, sexo, microorganismo aislado, factor predisponente, clasificación de riesgo. Se trabajó con 95 por ciento de confiabilidad lo que significó que valores de p por debajo de 0,05 fueron considerados como significativos. Se realizó el procesamiento en el programa SPSS versión 22.0. Resultados: De 58 pacientes estudiados solo tuvieron recurrencia 6,9 por ciento; de los que no recibieron quimioprofilaxis ninguno tuvo recurrencia y los que recibieron tratamiento quimioprofiláctico, 4 tuvieron recurrencia, por lo que haber recibido o no quimioprofilaxis no influyó en la aparición de recurrencia y menos después de 18 meses de una primera infección urinaria. Conclusiones: La presencia de recurrencias después de 18 meses de una primera infección urinaria en niños menores de 2 años no es un evento frecuente y parece que la quimioprofilaxis no es efectiva(AU)

Introduction: Urinary symptoms are the most frequent reason for pediatric consultation related to the urinary system during any time of the year and at any age. The arguments for the use or not of chemoprophylaxis to avoid recurrences are variable. Objective: Confirm the effectiveness of chemoprophylaxis to prevent recurrences of urinary tract infections in children aged 1 to 24 months. Methods: A quasi-experiment consisting of 58 patients admitted to the Children's Hospital of Holguín who met the inclusion criteria was conducted. The study variables were: number of recurrences, time of onset during observation, presence of recurrence, chemoprophylaxis, type of chemoprophylaxis, age, sex, isolated microorganism, predisposing factor, risk classification. We worked with 95 percent of reliability which meant that p values below 0.05 were considered significant. Processing was performed in the SPSS version 22.0 program. Results: From the 58 patients studied, only 6.9% had recurrence; of those who did not receive chemoprophylaxis none had recurrence and of those who received chemoprophylactic treatment, 4 had recurrence; so, having received or not chemoprophylaxis did not influence the appearance of recurrence and less after 18 months of a first urinary infection. Conclusions: The presence of recurrences after 18 months of a first urinary tract infection in children under 2 years of age is not a frequent event and it seems that chemoprophylaxis is not effective(AU)

Urinary Viral Shedding of COVID-19 and its Clinical Associations: A Systematic Review and Meta-analysis of Observational Studies.

OBJECTIVES: To review the current literature on the presence of COVID-19 virus in the urine of infected patients and to explore the clinical features that can predict the presence of COVID-19 in urine. MATERIALS AND METHODS: A systematic review of published literature between 30th December 2019 and 21st June 2020 was conducted on Pubmed, Google Scholar, Ovid, Scopus, and ISI web of science. Studies investigating urinary viral shedding of COVID-19 in infected patients were included. Two reviewers selected relative studies and performed quality assessment of individual studies. Meta-analysis was performed on the pooled case reports and cohort with a sample size of ≥ 9. RESULTS: Thirty-nine studies were finally included in the systematic review; 12 case reports, 26 case series, and one cohort study. Urinary samples from 533 patients were investigated. Fourteen studies reported the presence of COVID-19 in the urinary samples from 24 patients. The crude overall rate of COVID-19 detection in urinary samples was 4.5%. Considering case series and cohorts with a sample size of ≥ 9, the estimated viral shedding frequency was 1.18 % (CI 95%: 0.14 - 2.87) in the meta-analysis. Urinary viral load in most reports were lower than rectal or oropharyngeal samples. In adult patients, urinary shedding of COVID-19 was commonly detected in patients with moderate to severe disease (16 adult patients with moderate or severe disease versus two adult patients with mild disease). In children, urinary viral shedding of COVID-19 was reported in 4 children who all suffered from mild disease. Urinary viral shedding of COVID-19 was detected from day 1 to day 52 after disease onset. The pathogenicity of virus isolated from urine has been demonstrated in cell culture media in one study while another study failed to reveal replication of isolated viral RNA in cell cultures. Urinary symptoms were not attributed to urinary viral shedding. CONCLUSION: While COVID-19 is rarely detected in urine of infected individuals, infection transmission through urine still remains possible. In adult patients, infected urine is more likely in the presence of moderate or severe disease. Therefore, caution should be exerted when dealing with COVID-19 infected patients during medical interventions like endoscopy and urethral catheterization especially in symptomatic adult patients while in children caution should be exerted regardless of symptoms.

Characterization and spontaneous induction of urinary tract Streptococcus anginosus prophages.

Streptococcus anginosus is an often overlooked and understudied emerging pathogen inhabiting many areas of the human body. Through our sequencing of S. anginosus strains isolated from the female bladder microbiota, we detected numerous prophage sequences. Bioinformatic analysis of these sequences identified 17 distinct groups of S. anginosus prophages. The majority of these phages exhibit no sequence homology to previously characterized temperate or virulent phage sequences, indicating an unexplored diversity of Streptococcus phages. By culturing these bacterial isolates, we confirmed that the prophages of five of these groups are capable of induction. One of these putative phages was imaged, the first such evidence of an S. anginosus virus-like particle; it exhibits morphological characteristics of siphoviruses.

[The role of viral infection in the development of recurrent lower urinary tract infections].

This review is dedicated to the problems of diagnosing recurrent lower urinary tract infections caused by viruses. The literature search was conducted using the Medline, PubMed, EMBASE, CNKI, and WANG FANG databases. Further study of virobiota and microbiome of urine both in normal and in pathological conditions are warranted.

Detection and molecular characterization of urinary tract HIV-1 populations.

BACKGROUND: Identification of all possible HIV reservoirs is an important aspect in HIV eradication efforts. The urinary tract has however not been well studied as a potential HIV reservoir. In this pilot study we molecularly characterized HIV-1 viruses in urine and plasma samples to investigate HIV-1 replication, compartmentalization and persistence in the urinary tract. METHODS: Prospectively collected urine and blood samples collected over 12-36 months from 20 HIV-1 infected individuals were analysed including sampling points from prior to and after ART initiation. HIV-1 pol gene RNA and DNA from urine supernatant and urine pellets respectively were analysed and compared to plasma RNA viruses from the same individual. RESULTS: HIV-1 nucleic acid was detected in urine samples from at least one time point in 8/20 (40%) treatment-naïve subjects compared to 1/13 (7.7%) individuals on antiretroviral treatment (ART) during periods of plasma viral suppression and 1/7 (14.3%) individuals with virological failure. HIV-1 RNA was undetectable in urine samples after ART initiation but HIV-1 DNA was detectable in one patient more than 6 months after treatment initiation. There was co-clustering of urine-derived pol sequences but some urine-derived sequences were interspersed among the plasma-derived sequences. CONCLUSIONS: Suppressive ART reduces HIV-1 replication in the urinary tract but HIV-1 DNA may persist in these cells despite treatment. A larger number of sequences would be required to confirm HIV compartmentalization in the urinary tract.

Bacteriophages of the Urinary Microbiome.

Bacterial viruses (bacteriophages) play a significant role in microbial community dynamics. Within the human gastrointestinal tract, for instance, associations among bacteriophages (phages), microbiota stability, and human health have been discovered. In contrast to the gastrointestinal tract, the phages associated with the urinary microbiota are largely unknown. Preliminary metagenomic surveys of the urinary virome indicate a rich diversity of novel lytic phage sequences at an abundance far outnumbering that of eukaryotic viruses. These surveys, however, exclude the lysogenic phages residing within the bacteria of the bladder. To characterize this phage population, we examined 181 genomes representative of the phylogenetic diversity of bacterial species within the female urinary microbiota and found 457 phage sequences, 226 of which were predicted with high confidence. Phages were prevalent within the bladder bacteria: 86% of the genomes examined contained at least one phage sequence. Most of these phages are novel, exhibiting no discernible sequence homology to sequences in public data repositories. The presence of phages with substantial sequence similarity within the microbiota of different women supports the existence of a core community of phages within the bladder. Furthermore, the observed variation between the phage populations of women with and without overactive bladder symptoms suggests that phages may contribute to urinary health. To complement our bioinformatic analyses, viable phages were cultivated from the bacterial isolates for characterization; a novel coliphage was isolated, which is obligately lytic in the laboratory strain Escherichia coli C. Sequencing of bacterial genomes facilitates a comprehensive cataloguing of the urinary virome and reveals phage-host interactions.IMPORTANCE Bacteriophages are abundant within the human body. However, while some niches have been well surveyed, the phage population within the urinary microbiome is largely unknown. Our study is the first survey of the lysogenic phage population within the urinary microbiota. Most notably, the abundance of prophage exceeds that of the bacteria. Furthermore, many of the prophage sequences identified exhibited no recognizable sequence homology to sequences in data repositories. This suggests a rich diversity of uncharacterized phage species present in the bladder. Additionally, we observed a variation in the abundances of phages between bacteria isolated from asymptomatic "healthy" individuals and those with urinary symptoms, thus suggesting that, like phages within the gut, phages within the bladder may contribute to urinary health.

Fate of the Urinary Tract Virus BK Human Polyomavirus in Source-Separated Urine.

Human polyomaviruses are emerging pathogens that infect a large percentage of the human population and are excreted in urine. Consequently, urine that is collected for fertilizer production often has high concentrations of polyomavirus genes. We studied the fate of infectious double-stranded DNA (dsDNA) BK human polyomavirus (BKPyV) in hydrolyzed source-separated urine with infectivity assays and quantitative PCR (qPCR). Although BKPyV genomes persisted in the hydrolyzed urine for long periods of time (T90 [time required for 90% reduction in infectivity or gene copies] of >3 weeks), the viruses were rapidly inactivated (T90 of 1.1 to 11 h) in most of the tested urine samples. Interestingly, the infectivity of dsDNA bacteriophage surrogate T3 (T90 of 24 to 46 days) was much more persistent than that of BKPyV, highlighting a major shortcoming of using bacteriophages as human virus surrogates. Pasteurization and filtration experiments suggest that BKPyV virus inactivation was due to microorganism activity in the source-separated urine, and SDS-PAGE Western blots showed that BKPyV protein capsid disassembly is concurrent with inactivation. Our results imply that stored urine does not pose a substantial risk of BKPyV transmission, that qPCR and infectivity of the dsDNA surrogate do not accurately depict BKPyV fate, and that microbial inactivation is driven by structural elements of the BKPyV capsid.IMPORTANCE We demonstrate that a common urinary tract virus has a high susceptibility to the conditions in hydrolyzed urine and consequently would not be a substantial exposure route to humans using urine-derived fertilizers. The results have significant implications for understanding virus fate. First, by demonstrating that the dsDNA (double-stranded DNA) genome of the polyomavirus lasts for weeks despite infectivity lasting for hours to days, our work highlights the shortcomings of using qPCR to estimate risks from unculturable viruses. Second, commonly used dsDNA surrogate viruses survived for weeks under the same conditions that BK polyomavirus survived for only hours, highlighting issues with using virus surrogates to predict how human viruses will behave in the environment. Finally, our mechanistic inactivation analysis provides strong evidence that microbial activity drives rapid virus inactivation, likely through capsid disassembly. Overall, our work underlines how subtle structural differences between viruses can greatly impact their environmental fate.

Human Polyomavirus Is Associated With Earlier Onset of Upper Urinary Tract Urothelial Carcinoma in Patients After Kidney Transplantation.

OBJECTIVES: Polyomavirus has been reported to be oncogenic due to viral integration into the human genome. A relatively high prevalence of upper urinary tract urothelial carcinoma (UTUC) was noted after kidney transplantation (KT) in Taiwan. However, little was known about the impact of polyomavirus on the urothelial cancer behavior. Therefore, the aim of this study is to analyze the characteristics of polyomavirus-related UTUC after KT. METHODS: From 2005 to 2014, 27 patients were found to have UTUCs after KT. All the patients underwent standard nephroureterectomy. Detailed perioperative parameters were obtained from chart records. A qualified pathologist who is blinded to the clinical outcome examined large T antigen expression and pathological features. All the patients were divided into two groups according to positive or negative expression of large T antigen. RESULTS: In the patient demography, a significantly younger median age was found in patients with large T antigen-positive UTUCs compared with the negative control group (48.1 ± 8.3 years versus 54.6 ± 4.1 years, respectively, P = .013). As for the pathological features and oncologic outcome, there were no obvious differences between these two groups. Non-organ-confined status and positive lymphovascular invasion are prognostic factors associated with systemic disease recurrence (P = .017 and .001, respectively). CONCLUSIONS: Although UTUC commonly develops in the elderly, earlier onset of post-KT UTUCs was observed especially in patients with positive large T antigen expression in our cohort. This preliminary result provides valuable experience suggesting more frequent upper urinary tract screening for polyomavirus infected patients after KT in Taiwan.

Polyomavirus infection of the urinary tract presenting as hemorrhagic cystitis in an immunocompetent five-year-old boy.

Human polyomavirus infection, which can be detected morphologically on Pap-stained routine urine cytology specimens, is most commonly encountered in immunocompromised patients and is a well-described complication of renal transplantation. We present a case of an immunocompetent 5-year-old boy with a sudden onset of dysuria and hematuria due to a self-limited polyomavirus urinary tract infection detected on routine urine cytology and confirmed with real-time PCR. Although rare cases of nonhemorrhagic cystitis have been reported, to the best of our knowledge this is the first case of hemorrhagic cystitis occurring in this setting.

Minute excretion of highly pathogenic avian influenza virus A/chicken/Indonesia/2003 (H5N1) from experimentally infected domestic pigeons (Columbia livia) and lack of transmission to sentinel chickens.

Five out of sixteen domestic pigeons, inoculated oculo-nasally with a high dose of highly pathogenic avian influenza virus A/chicken/Indonesia/2003 (H5N1), developed clinical signs and neurological lesions leading to death of three pigeons 5-7 days after inoculation [Klopfleisch, R., Werner, O., Mundt, E., Harder, T. & Teifke, J. P. (2006). Vet Pathol 43, 463-470]. H5N1 virus was recovered from all organs sampled from two apparently healthy pigeons at 3 days post-infection and from the three pigeons which died spontaneously. All surviving birds shed virus via the oropharynx and the cloaca at minimal titres and seroconverted. Sentinel chickens reared in direct contact to the pigeons neither developed clinical signs nor seroconverted to the H5N1 virus.

Polyomavirus reactivation in native kidneys of pancreas alone allograft recipients.

BACKGROUND: Polyomavirus infection is common in childhood, with a seroprevalence of 60% to 100%. These viruses remain latent mostly in the kidney. Impairment in cellular immunity can allow reactivation of the virus. Reactivation can occur in 10% to 45% of renal allografts. A higher intensity of immunosuppression and the allogeneic microenvironment of the graft have been suggested to predispose to reactivation. There are limited data on the status of viral activity in the native kidneys of non-renal solid organ recipients. METHODS: Thirty-eight recipients of pancreas transplant alone were evaluated for evidence of polyomavirus reactivation by urine cytology. All had received induction therapy and were maintained on tacrolimus, mycophenolate mofetil, and prednisone. The renal function and degree of exposure to immunosuppressive agents of patients shedding polyomavirus-infected renal tubular cells were compared with those of patients with negative urine cytology. RESULTS: Screening cytology was performed 16 months (mean) after transplantation. Four subjects (11%) had polyomaviruria. The renal function at baseline and time of screening was comparable between the two groups. The 12-hour trough levels of tacrolimus were significantly higher in patients with positive cytology compared with those without viruria. The doses of mycophenolate mofetil and prednisone were not different between the two groups. CONCLUSION: This study shows that polyomavirus reactivation in native kidneys and urinary tract of pancreas transplant alone patients is not uncommon. In these recipients, viral reactivation was not associated with significant renal functional impairment. The results also suggest that patients who are exposed to higher blood levels of tacrolimus are at higher risk of viral reactivation.

Pathogenesis of experimental Ebola virus infection in guinea pigs.

The subtype Zaire of Ebola (EBO) virus (Mayinga strain) was adapted to produce lethal infections in guinea pigs. In many ways, the disease was similar to EBO infections in nonhuman primates and humans. The guinea pig model was used to investigate the pathologic events in EBO infection that lead to death. Analytical methods included immunohistochemistry, in situ hybridization, and electron microscopy. Cells of the mononuclear phagocyte system, primarily macrophages, were identified as the early and sustained targets of EBO virus. During later stages of infection, interstitial fibroblasts in various tissues were infected, and there was evidence of endothelial cell infection and fibrin deposition. The distribution of lesions, hematologic profiles, and increases in serum biochemical enzymes associated with EBO virus infection in guinea pigs was similar to reported findings in experimentally infected nonhuman primates and naturally infected humans.

Immunohistochemical detection of hog cholera viral glycoprotein 55 in paraffin-embedded tissues.

Formalin-fixed, paraffin embedded tissues obtained from 40 pigs inoculated with a field isolate of hog cholera virus were examined for the presence of Gp55, a major structural protein of the virus envelope, using a monoclonal antibody-based immunohistochemical test with the avidin-biotin-peroxidase complex method. Immunoreactivity was detected in hog cholera virus-infected tissues but not in control pigs tissues, African swine fever virus-infected tissues, or bovine viral diarrhea virus-infected porcine or bovine tissues. The first positive reactions were seen in lymphatic tissues, digestive tract and skin on postinoculation day (pid) 4, respiratory and urinary tissues on pid 5, nervous tissues on pid 6, and endocrine tissues on pid 7. These staining reactions persisted until the last observation on pid 18. Hog cholera virus antigen was not detected in heart tissue at any time. The highest levels of antigen detection were found in tonsils, spleen, and pancreas, although the esophageal mucosa and skin epithelial cells were also intensely and widely stained. The cellular staining pattern of Gp55 had a ubiquitous distribution. It was found in epithelial cells, macrophages and circulating monocytes, endothelial cells, lymphoid cells, and glial cells. The results showed a high specificity and high sensitivity for detecting hog cholera Gp55 in formalin-fixed, paraffin embedded tissue samples. This method allows precise association of Gp55 with specific cells, tissues, and histologic lesions, making the technique suitable for use in routine diagnosis of hog cholera.

Apoptosis in human papillomavirus16 E7-, but not E6-immortalized human uroepithelial cells.

We compared the ability of E6-, versus E7-, immortalized human uroepithelial cells (HUC) to undergo apoptosis in response to gamma radiation. Two independent HPV16 E6-immortalized cell lines, alphaE6#1 and alphaE6#2, that showed low or undetectable p53 levels, failed to undergo apoptosis in response to 18 Gray (Gy) gamma radiation as determined by DNA fragmentation. In contrast, two independent HPV16 E7-immortalized cell lines, alphaE7#1 and alphaE7#2, both of which showed stabilized wildtype p53, underwent apoptosis in the same experiment. Interestingly, both alphaE7#1 and alphaE7#2 showed constitutively elevated BAX and lowered BCL-2 levels, compared to either alphaE6#1 or alphaE6#2. However, elevated BAX and reduced BCL-2 per se were insufficient to trigger apoptosis, as apoptosis occurred only after exposure to gamma radiation. These results support a model in which HPV16 E7-immortalized cells are primed to undergo apoptosis, given an appropriate trigger. This apoptotic response was not observed in alphaE6/E7#1 cells which, like alphaE6-HUCs, showed low p53 levels, nor in late passage alphaE7#1 with spontaneously mutated TP53. These results suggest that E7 immortalization primes HUC for apoptosis in response to gamma radiation, and that this enhanced apoptotic response is p53 dependent.