Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Basic variables of the haemagglutination inhibition (HI) test for porcine parvovirus antibody were investigated. Nonspecific serum inhibitors were satisfactorily removed without loss of specific antibody when undiluted serum was adsorbed with 25 percent kaolin in borate saline at pH 9.0. Natural haemagglutinins in test serums could be completely removed using 0.1 ml of packed erythrocytes to 0.6 ml of kaolin treated serums. Adsorption of prediluted serum resulted in a depression of specific antibody titres. Highest HI titres were obtained using guinea pig erythrocytes, following incubation of virus-serum mixtures for 18 hours at 4 degrees C, 3 hours at 25 degrees C or 2 hours at 37 degrees C. Micro- and macro-tests gave comparable HI titres.
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PMID:A standardised haemagglutination inhibition test for porcine parvovirus antibody. 101 68

DNA sequences between 0 and 98.8 genome map units (m.u.) from canine parvovirus (CPV) and feline panleukopenia virus (FPV) were cloned into plasmid vectors to form infectious molecular clones. Those plasmids were transfected into permissive cells and viruses recovered were shown to contain intact genomes, having regenerated the complete viral 5' ends up to 100 m.u. The viruses derived from the plasmids were compared to the original viruses, and shown to be indistinguishable in antigenic type, hemagglutination (HA) type and host range. The plasmid origin of the viruses was shown by preparing recombinant clones between CPV and FPV, and demonstrating the recombinant nature of the resulting viruses by restriction mapping and by sequencing viral DNA across the recombination sites. The sequences of our wild-type isolates CPV-d and FPV-b were completed, revealing 50 nucleotide sequence differences, of which 16 determined coding changes--5 in NS-1,2 in NS-2, and 9 in VP-2 protein. The sequences of the 5' ends (95.3-100 m.u.) of both viruses were also determined. Analysis of recombinant viruses mapped both CPV- and FPV-specific antigenic epitopes, the pH dependence of HA, and sequences affecting canine host range of the viruses within the VP-1 and VP-2 structural protein genes. Most of the specific changes were shown to be either on, or within one amino acid of, the surface of the virus capsid, indicating that the exposed surface of the parvovirus capsid plays an important role in determining a number of virus functions. The specific epitopes were affected by differences in a raised area on the capsid ("threefold spike"), while the pH dependence of HA difference was adjacent to a depression in the surface of the capsid at the twofold axis of symmetry.
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PMID:Mapping specific functions in the capsid structure of canine parvovirus and feline panleukopenia virus using infectious plasmid clones. 164 68

The three-dimensional atomic structure of a single-stranded DNA virus has been determined. Infectious virions of canine parvovirus contain 60 protein subunits that are predominantly VP-2. The central structural motif of VP-2 has the same topology (an eight-stranded antiparallel beta barrel) as has been found in many other icosahedral viruses but represents only about one-third of the capsid protein. There is a 22 angstrom (A) long protrusion on the threefold axes, a 15 A deep canyon circulating about each of the five cylindrical structures at the fivefold axes, and a 15 A deep depression at the twofold axes. By analogy with rhinoviruses, the canyon may be the site of receptor attachment. Residues related to the antigenic properties of the virus are found on the threefold protrusions. Some of the amino termini of VP-2 run to the exterior in full but not empty virions, which is consistent with the observation that some VP-2 polypeptides in full particles can be cleaved by trypsin. Eleven nucleotides are seen in each of 60 symmetry-related pockets on the interior surface of the capsid and together account for 13 percent of the genome.
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PMID:The three-dimensional structure of canine parvovirus and its functional implications. 200 20

The B19 strain of parvovirus causes several distinct and important clinical diseases in humans. Aplastic crisis in patients with chronic hemolytic anemia, persistent bone marrow depression in immunocompromised individuals, and hydrops fetalis all result from direct infection of hematopoietic cells by the virus. Erythema infectiosum, arthritis, and purpuric vasculitis are postinfectious manifestations of B19 parvovirus infection.
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PMID:Human parvovirus infections. 215 61

Feline parvovirus (FPV) causes leukopenia in naturally infected cats. We investigated the mechanism of hematopoietic depression by this virus in feline bone marrow cultured in vitro. In suspension cultures we demonstrated FPV propagation and replication using DNA molecular hybridization. Viral RNA and DNA were observed by in situ hybridization in about 10% of marrow cells at day 3. Granulocytes and their precursors were virtually absent from infected cultures after six days. Infected cells showed viral capsid protein predominantly in nuclei by immunofluorescence. In clonal assays, FPV most efficiently inhibited hematopoietic colony formation by myeloid progenitor cells (CFU-GM), but erythroid colony formation (BFU-E and CFU-E-derived) was also depressed in the presence of virus. Inhibition of colony formation could be abrogated by physical inactivation of the virus or preincubation with specific neutralizing antibodies. Recombinant human colony stimulating factors GM-CSF and G-CSF supported feline myelopoiesis in progenitor assays, and FPV completely inhibited factor dependent colony formation.
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PMID:Feline parvovirus propagates in cat bone marrow cultures and inhibits hematopoietic colony formation in vitro. 254 25

The clinical signs, hematologic changes, serum and fecal virus titers, specific antibody production and the occurrence of histologic lesions were studied in 22 nine-week-old seronegative beagle dogs inoculated by the oral and intravenous route with canine parvovirus. Approximately 30% of the dogs had clinical signs of pyrexia, depression, vomiting, and diarrhea irrespective of the route of inoculation. Events in the dogs inoculated intravenously preceded those in dogs inoculated orally by approximately two days. Only one dog died. Lymphopenia was the most consistent hematologic change. Viremia always preceded the initiation of fecal virus shedding. Viral titers in the serum and feces were significantly greater in symptomatic dogs compared to asymptomatic dogs. Termination of the plasma viremia coincided with the onset of the humoral immune response, but viremia persisted one day longer in symptomatic dogs. The severity of lymphoid tissue and intestinal infection, assessed by tissue immunofluorescence and histology, was also greater in symptomatic dogs. The severity of intestinal disease was highly correlated with the magnitude and duration of viremia.
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PMID:Pathogenesis of canine parvovirus enteritis: the importance of viremia. 298 78

The capsid protein sequences of 10 representative parvoviruses were aligned against the sequence and three-dimensional structure of canine parvovirus (CPV). The structure of CPV was then analyzed after mapping onto it position-dependent sequence similarity scores and the locations of residues that are phenotypically important in other parvoviruses. Antigenicity is primarily associated with external exposed loops of high sequence variability. Amino acids in the canyon, a surface depression encircling each fivefold axis, are well conserved, but may have a function other than external receptor binding. Residues important to parvoviral cell specificity and erythrocyte binding are scattered near the rim of a less-conserved depression near the twofold axis, and on a shoulder of the threefold spike. The number of residues involved in various interactions and their conservation and properties suggest that uncoating may involve separation of fivefold and twofold related subunits before those related by threefold symmetry. The inner surface residues of the capsid are generally more highly conserved than those on the outer surface, presumably due to interactions with DNA, although the binding site that contains ordered DNA in the structure is not especially conserved.
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PMID:Structure, sequence, and function correlations among parvoviruses. 850 70

An antigen-delivery system based on hybrid virus-like particles (VLPs) formed by the self-assembly of the capsid VP2 protein of canine parvovirus (CPV) and expressing foreign peptides was investigated. In this report, we have studied the effects of inserting the poliovirus C3:B epitope in the four loops and the C terminus of the CPV VP2 on the particle structure and immunogenicity. Epitope insertions in the four loops allowed the recovery of capsids in all of the mutants. However, only insertions of the C3:B epitope in VP2 residue 225 of the loop 2 were able to elicit a significant anti-peptide antibody response, but not poliovirus-neutralizing antibodies, probably because residue 225 is located in an small depression of the surface. To fine modulate the insertion site in loop 2, a cassette-mutagenesis was carried out to insert the epitope in adjacent positions 226, 227, and 228. The epitope C3:B inserted into these positions was well recognized by the specific monoclonal antibody C3 by immunoelectron microscopy. BALB/c mice immunized with these chimeric C3:B CPV:VLPs were able to elicit an strong neutralizing antibody response (>3 log(10) units) against poliovirus type 1 (Mahoney strain). Therefore, minor displacements in the insertion place cause dramatic changes in the accessibility of the epitope and the induction of antibody responses.
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PMID:Minor displacements in the insertion site provoke major differences in the induction of antibody responses by chimeric parvovirus-like particles. 1054 85

One-day-old gnotobiotic piglets were inoculated intranasally with in vitro passaged porcine circovirus 1 (PCV-1), PCV-2, and porcine parvovirus (PPV) alone or in combination (PCV-1/PCV-2, PCV-1/PPV, and PCV-2/PPV). Piglets were evaluated for 1) the development of porcine postweaning multisystemic wasting syndrome (PMWS), 2) distribution of viral antigens by immunochemistry, and 3) viremia and the presence of viral DNA in nasal and ocular secretions and feces. All single agent-infected piglets and piglets infected with PCV-1/PCV-2 or PCV-1/PPV were clinically asymptomatic. They were transiently viremic and seroconverted to homologous virus(es). At termination of the study on postinfection day (PID) 35, microscopic lesions were restricted to focal inflammatory cell infiltrates in livers and myocardia. One piglet given PCV-1/PPV was PPV viremic for 2 weeks after infection and had lymphangiectasia of the spiral and descending colon associated with granulomatous inflammation. All four PCV-2/PPV-inoculated piglets developed PMWS, characterized by sudden onset of depression and anorexia, icterus, and submucosal edema. One piglet became moribund on PID 27, and the remaining three piglets were euthanatized between PID 27 and PID 30 because of severe disease. Lymph nodes were small and the livers were mottled. Disseminated angiocentric granulomatous inflammation was present in all tissues examined except the brain. Multiple lightly basophilic intracytoplasmic inclusion bodies were identified in macrophages and histiocytes. PCV-2 antigen was widely distributed within macrophages; PPV antigen was sparse. Hepatocellular necrosis and bile retention were prominent. PCV-2 DNA was identified in ocular, fecal, and nasal secretions. Terminal sera contained antibodies to PPV (4/4) and PCV-2 (3/ 4). Production of PMWS in gnotobiotic swine appears to require PCV-2 and additional infectious agents such as PPV for full disease expression in gnotobiotic piglets.
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PMID:Viral wasting syndrome of swine: experimental reproduction of postweaning multisystemic wasting syndrome in gnotobiotic swine by coinfection with porcine circovirus 2 and porcine parvovirus. 1081 Sep 90

Appropriate preconception health care improves pregnancy outcomes. When started at least one month before conception, folic acid supplements can prevent neural tube defects. Targeted genetic screening and counseling should be offered on the basis of age, ethnic background, or family history. Before conception, women should be screened for human immunodeficiency virus and syphilis infection and begin treatment to prevent the transmission of disease to the fetus. Immunizations against hepatitis B, rubella, and varicella should be completed, if needed. Women should be counseled on ways to prevent infection with toxoplasmosis, cytomegalovirus, and parvovirus B19. Environmental toxins such as cigarette smoke, alcohol, and street drugs, and chemicals such as solvents and pesticides should be avoided. In women with diabetes, it is important to optimize disease control through intensive management before pregnancy. Medications for hypertension, epilepsy, thromboembolism, depression, and anxiety should be reviewed and changed, if necessary, before the patient becomes pregnant. Counseling about exercise, obesity, nutritional deficiencies, and the overuse of vitamins A and D is beneficial. Physicians may also choose to discuss occupational and financial issues related to pregnancy and to screen patients for domestic violence.
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PMID:Preconception health care. 1261 25


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