We report the determination of the DNA sequence of the long repeat (RL) region and adjacent parts of the long unique (UL) region in the genome of herpes simplex virus type 2 (HSV-2) strain HG52. The DNA sequences and genetic content of the extremities of HSV-2 UL were found to be closely similar to those determined previously for HSV-1. The 5658 bp sequenced at the left end of HSV-2 UL contained coding regions for genes UL1 to UL4 plus part of UL5. The 4355 bp sequenced at the right end Of UL contained coding regions for part of gene UL53, and the whole of genes UL54 to UL56. Comparison of the HSV-1 and HSV-2 UL56 sequences led to a correction in the published HSV-1 UL56 reading frame. The HSV-2 R L region, including one copy of the a sequence, was determined to be 9263 bp, with a base composition of 75-4% G+C and with many repetitive sequence elements. In HSV-2 RL, sequences were identified corresponding to HSV-1 genes encoding the immediate early IE110 (ICP0) transcriptional regulator and the ICP34.5 neurovirulence factor; the former HSV-2 gene was proposed to contain two introns, and the latter one intron. Downstream of the HSV-2 immediate early gene, the RE sequence encoding the latency-associated transcripts (LATs) was found to be dissimilar to that in HSV-1; the probable LAT promoter regions, however, showed similarities to HSV-1. Properties of the LAT sequences in both HSV-1 and HSV-2 were consistent with LATs being generated as an intron excised from a longer transcript.
cleoside analogues, [8][9][10] the only established treatment option Hepatitis B virus (HBV) replicates via an intermediate to prevent reinfection is the administration of polyclonal hep-RNA step. High frequency of polymerase errors with adatitis B surface antigen antibody (anti-HBs) (hepatitis B imditional selection pressure leads to mutations in the mune globulin [HBIG]). HBIG reduces the rate of reinfection HBV genome. We investigated the number, type, and anfrom about 90% to less than 30% and improves the long-term tigenic effects of mutations in the coding region of the outcome of patients who underwent OLT for HBV-related HBV surface antigen in eight patients who underwent disease. 2-4orthotopic liver transplantation (OLT) for HBV-related A number of explanations for graft infection have been end-stage liver disease and were experiencing infection proposed. First, virions from the explanted liver are circulatof the graft and who received hepatitis B surface antigen ing in the blood during or soon after transplantation. Second, antibody (anti-HBs) prophylaxis (hepatitis B immune virions are replicating at extrahepatic sites. HBIG interferes globulin [HBIG]) after OLT. Controls were chronic HBV with this process and probably prevents virions from entering patients who underwent kidney transplantation and rehepatocytes. 11 The mechanisms that lead to reinfection in ceived the same immunosuppressive regime but no 30% of patients receiving HBIG after OLT are not under-HBIG. The S-gene was amplified from serum before and stood. after transplantation, sequenced, and changes in the ge-HBV employs reverse transcriptase for its replication; this nome were analyzed. In the five patients who experilacks proofreading capability, and thus leads to a higher enced reinfection while receiving anti-HBs, clear mutanumber of mutations in the HBV genome. 12 Some of these tions occurred in the S-gene. In the patient who did not variants may have a replication advantage and become domireceive HBIG and those who experienced reinfection nant. From the pool of variants with similar replication poonly after termination of HBIG, no mutations were tential, some will be positively selected by forces such as found in the S-gene. In the kidney recipients, mutations the humoral or cellular immune response 13; these are termed in the S-gene occurred in only one of eight patients. Beescape mutants. Evolution of viruses under antibody prescause the a determinant contains neutralizing epitopes, sure, either monoclonal or polyclonal, has been well studied this region was chosen for antibody binding to quantify both in vitro and in vivo. The addition of neutralizing antibodantigenic effects of the mutations. The two patients who ies to virus cultures regularly results in isolates that are not selected mutations in the a determinant and became reneutralized by the added antibodies. This is particularly true infected while receiving HBIG had reduced antibody with monoclonal reagents, because the change in viral antibinding after OLT. Our results...
Delayed post-operative endophthalmitis is a complication of modern cataract extraction and posterior chamber lens implantation. Propionibacterium acnes has been isolated in a few such cases but the majority are culture-negative, compounding surgical and medical management decisions. A method of detecting bacterial, and specifically P. acnes, DNA by the polymerase chain reaction (PCR) directed at 16S rDNA is reported. Nested PCR with universal eubacterial primers complimentary to regions of 16S rDNA conserved sequences detected 50 fg of bacterial DNA spike in normal vitreous. Nested PCR with P. acnes primers detected 10 fg of DNA. Vitreous samples from 29 patients undergoing vitrectomy for reasons unrelated to infection and 23 samples from 19 patients with delayed post-operative endophthalmitis were analysed. Four (14%) of 29 normal individuals and 17 (74%) of 23 delayed cases gave positive results with universal eubacterial primers. None of 29 and eight of 23 samples gave positive results with P. acnes primers. The 14% positive rate with universal primers in non-infected cases may limit their use in delayed post-operative endophthalmitis. PCR detection of bacterial DNA with specific primers from vitreous samples may prove a useful means of diagnosing delayed post-operative endophthalmitis and facilitating management decisions when conventional bacterial culture is negative.
Precore/core genes from hepatitis B e antigen (HBeAg)-positive and antibody to HBeAg (anti-HBe) positive individuals with active hepatitis have been analyzed to search for correlations with response to interferon before and after treatment. Pretreatment, no precore stop codon mutants were detected, even at the 3% level, in HBeAg-positive responders or nonresponders. In anti-HBe-positive patients, precore mutants did not influence response. No significant core amino acid variability was observed in HBeAg-positive patients, irrespective of interferon response. However, anti-HBe-positive cases had multiple core protein substitutions, mostly in B- ant T-helper cell epitopes, but responders had fewer (P = .02 for responders versus nonresponders and reactivators). None of four responders, three of seven reactivators, and three of three nonresponders had mutations within the major T-helper epitope from aa50 to aa69 (P = .03). Precore mutants appeared in eight of nine natural seroconverters compared with 3 of 10 interferon-induced anti-HBe seroconverters (P = .01). Those in whom precore wild-type remained after treatment often tested negative in the last available sample using polymerase chain reaction (PCR), whereas emergence of mutants led to ongoing viremia in all cases. In anti-HBe-positive cases, precore sequences remained stable during therapy, except for 2 cases in whom a precore mutant appeared accompanied by reactivation. In the core protein, anti-HBe-positive cases selected a mean of 3.5, 1.6, and 1.7 amino acid substitutions in responders, nonresponders, and reactivators respectively (P = NS). In conclusion, core but not precore sequence before therapy may predict response. Appearance of precore mutants during therapy usually predicts failure to clear virus but substitution in core does not influence outcome.
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