Restriction fragment analysis of bacteriophage SPP1 in vitro transcription by host RNA polymerase. (33/26780)

In vitro transcription of SPP1 DNA occurred on only one of the two strands, the same which is predominantly transcribed in SPP1-infected cells. Transcripts were distributed in several size classes. Analysis of elongation kinetics and of size distribution, coupled with hybridization to DNA restriction fragments, showed that some regions of the template have more initiation sites than others; some have none. Some regions were transcribed directly, some were transcribed from initiation sites located in other regions, and one was never transcribed. Several transcription initiation sites on SPP1 DNA are located on EcoRI fragment 1; four to five others are distributed among other fragments. Cutting the DNA with EcoRI did not introduce artifactual initiation sites. In vitro transcription units can be localized and oriented with respect to the EcoRI restriction map of SPP1 DNA.  (+info)

Rotavirus G-type restriction, persistence, and herd type specificity in Swedish cattle herds. (34/26780)

G-typing of rotavirus strains enables the study of molecular epidemiology and gathering of information to promote disease prevention and control. Rotavirus strains in fecal specimens from neonatal calves in Swedish cattle herds were therefore characterized by using G1 to -4-, G6-, G8-, and G10-specific primers in reverse transcription (RT)-PCR. Fecal samples were collected from one dairy herd (herd A) for 4 consecutive years and from 41 beef and dairy herds (herd B) experiencing calf diarrhea outbreaks. Altogether, 1, 700 samples were analyzed by group A rotavirus enzyme-linked immunosorbent assay, and 98 rotavirus-positive specimens were selected for G-typing by RT-PCR. The effect of herd type, time, geographic region, and clinical symptoms on the G-type distribution was evaluated. Altogether (herds A and B), G10 was found in 59 (60. 2%) fecal specimens, G6 was found in 30 (30.6%) specimens, G3 was found in 1 (1.0%) specimen, and G8 was found in 1 (1.0%) specimen. Seven (7.1%) fecal specimens were not typeable. Herd type specificity in the G-type distribution was demonstrated in the herds in herd B. In the 6 beef suckler herds, only G6 was detected, while rotavirus strains from the 35 dairy herds were predominantly (54%) G10. The G-type distribution was restricted in herds A and B. Twenty-nine of 30 strains from herd A were characterized as G10. In the vast majority of herds in herd B, a single G-type was identified. The serotype G10 and the electropherotype persisted over time in herd A. No characteristic G-type variation in the geographic distribution of cattle herds in herd B was obvious. There was no difference in the G-type distributions between the strains from clinically and subclinically rotavirus-infected calves in dairy herd A. The results from this study strongly indicate a pronounced stability in the rotavirus G-type distribution in Swedish cattle herds, which emphasizes the importance of continuous preventive measures for control of neonatal calf diarrhea. A future bovine rotavirus vaccine in Sweden should contain G10 and G6 strains.  (+info)

Human herpesviruses in chronic fatigue syndrome. (35/26780)

We have conducted a double-blind study to assess the possible involvement of the human herpesviruses (HHVs) HHV6, HHV7, Epstein-Barr virus (EBV), and cytomegalovirus in chronic fatigue syndrome (CFS) patients compared to age-, race-, and gender-matched controls. The CFS patient population was composed of rigorously screened civilian and Persian Gulf War veterans meeting the Centers for Disease Control and Prevention's CFS case definition criteria. Healthy control civilian and veteran populations had no evidence of CFS or any other exclusionary medical or psychiatric condition. Patient peripheral blood mononuclear cells were analyzed by PCR for the presence of these HHVs. Using two-tailed Fisher's exact test analyses, we were unable to ascertain any statistically significant differences between the CFS patient and control populations in terms of the detection of one or more of these viruses. This observation was upheld when the CFS populations were further stratified with regard to the presence or absence of major axis I psychopathology and patient self-reported gradual versus acute onset of disease. In tandem, we performed serological analyses of serum anti-EBV and anti-HHV6 antibody titers and found no significant differences between the CFS and control patients.  (+info)

Restricted isotypic antibody reactivity to hepatitis C virus synthetic peptides in immunocompromised patients. (36/26780)

An enzyme immunoassay based on three synthetic peptides from the core, NS4, and NS5 regions of hepatitis C virus allowed the detection of antibodies in 100% of immunocompetent infected patients and in 91% of immunocompromised patients (hemodialysis and hemophiliac patients). Immune impairment seemed to restrict the spectrum of antibody isotypes reacting to the core peptide.  (+info)

Effect of tetrahydropyrimidine derivatives on protein-nucleic acids interaction. Type II restriction endonucleases as a model system. (37/26780)

2-Methyl-4-carboxy,5-hydroxy-3,4,5,6-tetrahydropyri- midine (THP(A) or hydroxyectoine) and 2-methyl,4-carboxy-3,4,5, 6-tetrahydropyrimidine (THP(B) or ectoine) are now recognized as ubiquitous bacterial osmoprotectants. To evaluate the impact of tetrahydropyrimidine derivatives (THPs) on protein-DNA interaction and on restriction-modification systems, we have examined their effect on the cleavage of plasmid DNA by 10 type II restriction endonucleases. THP(A) completely arrested the cleavage of plasmid and bacteriophage lambda DNA by EcoRI endonuclease at 0.4 mM and the oligonucleotide (d(CGCGAATTCGCG))2 at about 4.0 mM. THP(B) was 10-fold less effective than THP(A), whereas for betaine and proline, a notable inhibition was observed only at 100 mM. Similar effects of THP(A) were observed for all tested restriction endonucleases, except for SmaI and PvuII, which were inhibited only partially at 50 mM THP(A). No effect of THP(A) on the activity of DNase I, RNase A, and Taq DNA polymerase was noticed. Gel-shift assays showed that THP(A) inhibited the EcoRI-(d(CGCGAATTCGCG))2 complex formation, whereas facilitated diffusion of EcoRI along the DNA was not affected. Methylation of the carboxy group significantly decreased the activity of THPs, suggesting that their zwitterionic character is essential for the inhibition effect. Possible mechanisms of inhibition, the role of THPs in the modulation of the protein-DNA interaction, and the in vivo relevance of the observed phenomena are discussed.  (+info)

Risk factors for abnormal anal cytology in young heterosexual women. (38/26780)

Although anal cancers are up to four times more common in women than men, little is known about the natural history of anal human papillomavirus (HPV) infections and HPV-related anal lesions in women. This study reports on the prevalence of and risks for anal cytological abnormalities over a 1-year period in a cohort of young women participating in a study of the natural history of cervical HPV infection. In addition to their regularly scheduled sexual behavior interviews and cervical testing, consenting women received anal HPV DNA and cytological testing. Anal cytology smears were obtained from 410 women whose mean age was 22.5 +/- 2.5 years at the onset of the study. Sixteen women (3.9%) were found to have abnormal anal cytology: 4 women had low-grade squamous intraepithelial lesions (SILs) or condyloma; and 12 women had atypical cells of undetermined significance. Factors found to be significantly associated with abnormal anal cytology were a history of anal sex [odds ratio (OR), 6.90; 95% confidence interval (CI), 1.7-47.2], a history of cervical SILs (OR, 4.13; 95% CI, 1.3-14.9), and a current anal HPV infection (OR, 12.28; 95% CI, 3.9-43.5). The strong association between anal intercourse and the development of HPV-induced SILs supports the role of sexual transmission of HPV in anal SILs. Young women who had engaged in anal intercourse or had a history of cervical SILs were found to be at highest risk.  (+info)

Persistently high Epstein-Barr virus (EBV) loads in peripheral blood lymphocytes from patients with chronic active EBV infection. (39/26780)

Chronic active Epstein-Barr virus infection (CAEBV) is a severe illness with unusual EBV activation that persists for years, and its pathogenesis is largely unknown. After the creation of an accurate and reproducible polymerase chain reaction system to quantify EBV DNA, virus loads in peripheral blood lymphocytes (PBL) were determined in 54 children: 15 with CAEBV, 16 with infectious mononucleosis (IM), and 23 healthy children. Children with CAEBV and those with IM had high virus loads. Lower loads were detected in 47% of seropositive healthy donors. There were two distinct differences between children with CAEBV and those with IM: The former had greater viral replication (10(3)-10(7) copies/2.5x10(5) PBL) than those with IM, and viral replication declined in children with IM whereas active replication persisted for years in subjects with CAEBV. Persisting high virus loads are a possible diagnostic criterion for CAEBV. EBV loads may enable classification and prognosis of EBV infections.  (+info)

Effective control of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis with immunochemotherapy. Histiocyte Society. (40/26780)

The familial form of hemophagocytic lymphohistiocytosis (HLH) is a lethal disorder. Although the prognosis for Epstein-Barr virus-associated HLH (EBV-HLH) remains uncertain, numerous reports indicate that it can also be fatal in a substantial proportion of cases. We therefore assessed the potential of immunochemotherapy with a core combination of steroids and etoposide to control EBV-HLH in 17 infants and children who met stringent diagnostic criteria for this reactive disorder of the mononuclear phagocyte system. Treatment of life-threatening emergencies was left to the discretion of participating investigators and typically included either intravenous Ig or cyclosporin A (CSA). Five patients (29%) entered complete remission during the induction phase (1 to 2 months), whereas 10 others (57%) required additional treatment to achieve this status. In 2 cases, immunochemotherapy was ineffective, prompting allogeneic bone marrow transplantation. Severe but reversible myelosuppression was a common finding; adverse late sequelae were limited to epileptic activity in one child and chronic EBV infection in 2 others. Fourteen of the 17 patients treated with immunochemotherapy have maintained their complete responses for 4+ to 39+ months (median, 15+ months), suggesting a low probability of disease recurrence. These results provide a new perspective on EBV-HLH, showing effective control (and perhaps cure) of the majority of EBV-HLH cases without bone marrow transplantation, using steroids and etoposide, with or without immunomodulatory agents.  (+info)