Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytomegalovirus (CMV) disease is a common and serious complication of allogeneic stem cell transplantation (SCT). Its two most frequent manifestations are interstitial pneumonitis and gastroenteritis. We describe here the first reported case of CMV ovarian infection in an allo-SCT recipient. This patient was included in a clinical trial of high-dose chemotherapy (HDCT) with HLA-matched peripheral SCT for metastatic breast cancer. She expired 53 days after transplantation from organ failure unrelated to her CMV oophoritis.
 ...
PMID:Post-mortem incidental finding of cytomegalovirus oophoritis after an allogeneic stem cell transplant. 1041 24

Historically, protection against virus infections has relied on the use of vaccines, but the induction of an immune response requires several days and in certain situations, like in newborn animals that may be infected at birth and die in a few days, there is not sufficient time to elicit a protective immune response. Immediate protection in new born could be provided either by vectors that express virus-interfering molecules in a tissue specific form, or by the production of animals expressing resistance to virus replication. The mucosal surface is the largest body surface susceptible to virus infection that can serve for virus entry. Then, it is of high interest to develop strategies to prevent infections of these areas. Virus growth can be interfered intracellularly, extracellularly or both. The antibodies neutralize virus intra- and extracellularly and their molecular biology is well known. In addition, antibodies efficiently neutralize viruses in the mucosal areas. The autonomy of antibody molecules in virus neutralization makes them functional in cells different from those that produce the antibodies and in the extracellular medium. These properties have identified antibodies as very useful molecules to be expressed by vectors or in transgenic animals to provide resistance to virus infection. A similar role could be played by antimicrobial peptides in the case of bacteria. Intracellular interference with virus growth (intracellular immunity) can be mediated by molecules of very different nature: (i) full length or single chain antibodies; (ii) mutant viral proteins that strongly interfere with the replication of the wild type virus (dominant-negative mutants); (iii) antisense RNA and ribozyme sequences; and (iv) the product of antiviral genes such as the Mx proteins. All these molecules inhibiting virus replication may be used to obtain transgenic animals with resistance to viral infection built in their genomes. We have developed two strategies to target into mucosal areas either antibodies to provide immediate protection, or antigens to elicit immune responses in the enteric or respiratory surfaces in order to prevent virus infection. One strategy is based on the development of expression vectors using coronavirus derived defective RNA minigenomes, and the other relies on the development of transgenic animals providing virus neutralizing antibodies in the milk during lactation. Two types of expression vectors are being engineered based on transmissible gastroenteritis coronavirus (TGEV) defective minigenomes. The first one is a helper virus dependent expression system and the second is based on self-replicating RNAs including the information required to encode the TGEV replicase. The minigenomes expressing the heterologous gene have been improved by using a two-step amplification system based on cytomegalovirus (CMV) and viral promoters. Expression levels around 5 micrograms per 10(6) cells were obtained. The engineered minigenomes will be useful to understand the mechanism of coronavirus replication and for the tissue specific expression of antigen, antibody or virus interfering molecules. To protect from viral infections of the enteric tract, transgenic animals secreting virus neutralizing recombinant antibodies in the milk during lactation have been developed. Neutralizing antibodies with isotypes IgG1 or IgA were produced in the milk with titers of 10(6) in RIA that reduced virus infectivity by one million-fold. The recombinant antibodies recognized a conserved epitope apparently essential for virus replication. Antibody expression levels were transgene transgene copy number independent and were related to the transgene integration site. This strategy may be of general use since it could be applied to protect newborn animals against infections of the enteric tract by viruses or bacteria for which a protective MAb has been identified. Alternatively, the same strategy could be used to target the expression of antibio
 ...
PMID:Interference with virus and bacteria replication by the tissue specific expression of antibodies and interfering molecules. 1065 42

Adenovirus infections have been reported in as many as one-fifth of bone marrow transplant (BMT) recipients and patients with acquired immunodeficiency syndrome (AIDS), and in a lesser, though still prominent, proportion of organ transplant recipients. The relative contributions of primary infections versus reactivations from latency in immunocompromised patients remain unclear. Compared with adult BMT recipients, pediatric BMT recipients appear to be infected by adenovirus more frequently and earlier in the post-transplant period. The diagnosis of adenovirus infection is complicated by the existence of > 40 viral serotypes, although certain subgroups are more likely to be involved in certain patient populations. Adenoviruses are responsible for a broad range of clinical diseases that may be associated with high mortality, including pneumonia, hepatitis, encephalitis, hemorrhagic cystitis, and gastroenteritis. The clinical and histopathologic features of adenovirus disease may resemble those of cytomegalovirus disease, potentially complicating the diagnosis. Risk factors for clinical adenovirus disease include the number of sites from which the virus is cultured and, in BMT recipients, the presence of moderate to severe acute graft-versus-host disease.
 ...
PMID:Adenovirus infections in immunocompromised patients. 1086 46

Down-modulation of CD3zeta expression on CD8 T lymphocytes occurs, independently of other T-cell receptor (TCR)-CD3 components, in tumor-infiltrating lymphocytes, human immunodeficiency virus infection, and autoimmune disease. These associations suggest that it might be related to chronic antigenic stimulation. CD3zeta down-modulation was found, however, in CD8 T cells that proliferate in response to acute viral infections. In 3 otherwise healthy donors with acute gastroenteritis, infectious mononucleosis, and Epstein-Barr virus/cytomegalovirus/mononucleosis, 30% to 60% of circulating CD8 T cells had down-modulated CD3zeta to below the level of detection. The CD3zeta-T cells were also CD28- but expressed the activation markers HLA-DR and CD57. CD3zeta-CD28- T cells are effector CTL because they express perforin and produce IFN-gamma, but not IL-2, on activation and contain the viral-specific cytotoxic T lymphocyte (CTL). However, CD3zeta-CD28-T cells generally do not express CD25 after anti-CD3 and anti-CD28 stimulation and are not cytotoxic until they are cultured with IL-2 overnight. Cytotoxicity coincides with the re-expression of CD3zeta but not CD28. Down-modulation of CD3zeta and CD28 on effector CTL may control CTL triggering and proliferation to prevent immunopathogenesis.
 ...
PMID:CD3zeta and CD28 down-modulation on CD8 T cells during viral infection. 1091 Sep 18

Cytomegalovirus (CMV) can be an important opportunistic infection in HIV-1-infected patients, particularly when the CD4+ T-cell count drops below 50 lymphocytes/mm3. CMV-associated disease, including retinitis, pneumonitis, gastroenteritis, and encephalitis, is estimated to affect up to 40% of AIDS patients. We have studied the cellular immune response to CMV in gut-associated lymphoid tissue (GALT) of HIV-1-infected patients. Two patients with chronic diarrhea of unknown etiology were examined by flexible sigmoidoscopy and upper endoscopy. Biopsy specimens were obtained from lymphoid-associated tissue sites in rectum and duodenum. Both patients were seropositive for CMV IgG, but had not been treated with ganciclovir, and neither had clinical signs of CMV disease. Mononuclear cell cultures were established from GALT and blood and assayed for the presence of CMV-specific CD8+ T cells. CD8+ T-cell phenotype and function were assessed by MHC Class I tetramer staining, using an HLA-A*0201 tetramer complex specific for peptide 495-503 (NLVPMVATV) of CMV lower matrix protein pp65, and by a standard 51Cr release assay. CMV pp65-specific cytotoxic lymphocytes (CTL) were detected in GALT and blood MNC from both patients. These results demonstrate that HIV-1-infected subjects seropositive for CMV, but without active CMV gastrointestinal disease, harbor CMV-specific CTL in intestinal lymphoid tissue. This is the first report of isolation of CMV-specific CTL in GALT and will lead to greater understanding of the pathogenesis of CMV disease in human mucosal tissue.
 ...
PMID:Isolation of cytomegalovirus-specific cytotoxic T-lymphocytes from gut-associated lymphoid tissue (GALT) of HIV type 1-infected subjects. 1095 91

Acute gastroenteritis is common in adults. It can occur in institutional epidemics or epidemics of food-borne illness; in these cases, caliciviruses are the major cause of the condition. When acute gastroenteritis occurs in nonepidemic form, its causes are less clear. It may be due to caliciviruses or to the less common serotypes of childhood gastroenteritis viruses, such as rotavirus, astrovirus, and adenovirus. The pathogenesis of acute viral gastroenteritis is not completely understood. Old evidence suggests that mild villus damage is responsible, but new evidence indicates that active secretion and motility disturbance may be involved in the production of symptoms. Five common viruses can remain latent in gastrointestinal tissues and produce disease many years after initial infection. Two major herpesviruses, cytomegalovirus and herpes simplex virus, cause ulcerative disease of the gastrointestinal tract. This disease occurs in healthy persons but is more common and more severe in immunocompromised patients. Three other viruses--Epstein-Barr virus, human papilloma virus, and human herpesvirus-8--are implicated in benign and malignant proliferative diseases of the gastrointestinal tract. Epstein-Barr virus has been associated with immunoproliferative disease after transplantation and may also cause small-bowel and colonic lymphoma in healthy adults. It causes most AIDS-related lymphomas. Human papillomaviruses cause anorectal condyloma and anal cancer. Human herpesvirus-8 causes gastrointestinal Kaposi sarcoma.
 ...
PMID:Viral infections of the gastrointestinal tract. 1098 Sep 63

Rhodococcus equi is a common cause of pneumonia in animals. Human infection is rare. Increasing number of cases are being reported in immunosuppressed individuals mostly associated with HIV infection, but also in solid organ transplant recipients and leukemia/lymphoma patients. We report on an adult male who developed pneumonia and gastroenteritis 4 mo after receiving a renal transplant. CT scan of the lungs showed a dominant 2.5-cm upper lobe lung mass and smaller bilateral nodules. He underwent a diagnostic bronchoscopy with fine-needle aspiration biopsy of the largest lung nodule. Smears showed histiocytic granulomatous inflammation, foamy macrophages, and acute inflammatory exudate. Scattered foamy macrophages displayed intracellular coccobacilli identifiable on Diff-Quik stain. A few cells with changes suggestive of viral inclusions were identified. Cytomegalovirus (CMV) immunostain was positive in the cell block sections. Lung cultures grew R. equi. To the best of our knowledge, this is the first report of coinfection with R. equi and CMV.
 ...
PMID:Rhodococcus equi and cytomegalovirus pneumonia in a renal transplant patient: diagnosis by fine-needle aspiration biopsy. 1116 94

The stable propagation of a full-length transmissible gastroenteritis coronavirus (TGEV) cDNA in Escherichia coli cells as a bacterial artificial chromosome has been considerably improved by the insertion of an intron to disrupt a toxic region identified in the viral genome. The viral RNA was expressed in the cell nucleus under the control of the cytomegalovirus promoter and the intron was efficiently removed during translocation of this RNA to the cytoplasm. The insertion in two different positions allowed stable plasmid amplification for at least 200 generations. Infectious TGEV was efficiently recovered from cells transfected with the modified cDNAs.
 ...
PMID:Stabilization of a full-length infectious cDNA clone of transmissible gastroenteritis coronavirus by insertion of an intron. 1193 33

A prospective study of 62 chemotherapy-induced neutropenic episodes in patients with acute leukaemia was conducted to determine the incidence and causes of abdominal infections, and to assess the diagnostic value of the combined use of ultrasonography (US) and microbiology. Each patient underwent US of liver, gallbladder and complete bowel before chemotherapy, on days 2-4 after the end of chemotherapy and in cases of fever, diarrhoea or abdominal pain. US was combined with a standardized clinical examination and a broad spectrum of microbiological investigations. From January to August 2001, 243 US examinations were performed. The overall incidence of abdominal infectious diseases was 17.7% (11 out of 62, 95% confidence interval (CI): 9-29%). Four patients (6.5%) developed neutropenic enterocolitis; two of them died, two survived. Bowel wall thickening (BWT) > 4 mm in these four patients ranged from 5.8 to 23.6 mm and was detected only in one patient with mucositis. In three other patients (4.8%) Clostridium difficile, and in one patient (1.6%) Campylobacter jejuni, caused enterocolitis without BWT. Cholecystitis was diagnosed in three patients (4.8%) and hepatic candidiasis was strongly suspected in one patient. Abdominal infections caused by gastroenteritis viruses, cytomegalovirus (CMV) or Cryptosporidium were not observed. We conclude that in neutropenic patients with acute leukaemia receiving chemotherapy: (i) BWT is not a feature of chemotherapy-induced mucositis and should therefore be considered as sign of infectious enterocolitis; (ii) viruses, classic bacterial enteric pathogens (Salmonella, Shigella, Yersinia, Campylobacter, Aeromonas, Vibrio subsp., enterohaemorrhagic Escherichia coli) and Cryptosporidium have a very low incidence; and (iii) abdominal infections may be underestimated when US is not used in every patient with abdominal pain.
 ...
PMID:Abdominal infections in patients with acute leukaemia: a prospective study applying ultrasonography and microbiology. 1197 17

To locate the transmissible gastroenteritis coronavirus (TGEV) packaging signal, the incorporation of TGEV subgenomic mRNAs (sgmRNAs) into virions was first addressed. TGEV virions were purified by three different techniques, including an immunopurification using an M protein-specific monoclonal antibody. Detection of sgmRNAs in virions by specific reverse transcription-PCRs (RT-PCRs) was related to the purity of virus preparations. Interestingly, virus mRNAs were detected in partially purified virus but not in virus immunopurified using stringent conditions. Analyses by quantitative RT-PCR confirmed that virus mRNAs were not present in highly purified preparations. Lack of sgmRNA encapsidation was probably due to the absence of a packaging signal (Psi) within these mRNAs. This information plus that from the encapsidation of a collection of TGEV-derived minigenomes suggested that Psi is located at the 5' end of the genome. To confirm that this was the case, a set of minigenomes was expressed that included an expression cassette for an mRNA including the beta-glucuronidase gene (GUS) plus variable sequence fragments from the 5' end of the virus genome potentially including Psi. Insertion of the first 649 nucleotides (nt) of the TGEV genome led to the specific encapsidation of the mRNA, indicating that a Psi was located within this region which was absent from all of the other virus mRNAs. The presence of this packaging signal was further confirmed by showing the expression and rescue of the mRNA including the first 649 nt of the TGEV genome under control of the cytomegalovirus promoter in TGEV-infected cells. This mRNA was successfully amplified and encapsidated, indicating that the first 649 nt of TGEV genome also contained the 5' cis-acting replication signals. The encapsidation efficiency of this mRNA was about 30-fold higher than the genome encapsidation efficiency, as estimated by quantitative RT-PCR. In contrast, viral mRNAs presented significantly lower encapsidation efficiencies (about 100-fold) than those of the virus genome, strongly suggesting that TGEV mRNAs in fact lacked an alternative TGEV Psi.
 ...
PMID:Transmissible gastroenteritis coronavirus packaging signal is located at the 5' end of the virus genome. 1282 29


<< Previous 1 2 3 4 5 Next >>