Identification of a hypervariable region in the long terminal repeat of equine infectious anemia virus.

An avirulent, field-derived isolate of equine infectious anemia virus (EIAV), designated MA-1, was molecularly cloned, and the complete nucleotide sequence was determined for the 3' half of the viral genome. Comparisons between MA-1 and the prototype Wyoming strain of EIAV identified a 66-nucleotide stretch between CAAT (-91) and TATAA (-25) in the U3 region of the long terminal repeat, where sequence divergence was as high as 39.3%. The polymerase chain reaction was used to amplify and clone long terminal repeat sequences from Th-1, the in vivo parental stock of MA-1. Results indicated that the nucleotide sequences of MA-1 and Th-1 clones were less variable than was observed between MA-1 and Wyoming. However, MA-1 and Th-1 markedly differed in the types of enhancer sequences located in the hypervariable region. These results suggest that variation in lentivirus regulatory sequences may be important in EIAV host cell tropism and pathogenesis.     

10-Year Overview of the Hospital-Based Prevalence and Treatment of Congenital Cataracts: The CCPMOH Experience

A review of 6 years of hospitalization charts from Zhongshan Ophthalmic Center (ZOC) revealed that congenital cataracts (CC) accounted for 2.39% of all cataract in-patient cases and that the age at surgery was decreasing before the establishment of the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH) in December 2010. We aimed to investigate data from the 4 years (January 2011 to December 2014) following the establishment of the CCPMOH, compared, and combined with data from the previous study period (January 2005 to December 2010) to generate a 10-year overview of the hospital-based prevalence and treatment of CC. In the 4-year period after CCPMOH establishment, the prevalence of CC was 2.01% in all hospitalizations, and was 2.78% in all cataract in-patients. Most of the eligible CC in-patients (71%) lived in south China. The ratio of boys to girls was 1.42:1. Nearly 2/3 of the patients underwent cataract extraction with primary intraocular lens (IOL) implantation at a mean age of 78.40±51.45 months, and cataract extraction surgeries without IOL implantation were performed in the remaining 1/3 of patients at a mean age of 10.03±15.92 months. After CCPMOH establishment, an increased incidence of CC was revealed, and the CC in-patients were younger than the patients in the previous period. The 10-year overview (2421 CC in-patients from 206630 hospitalizations) revealed upward trends in both the number and the prevalence of CC and a further reduction in age at surgery. In conclusion, the data from 4-year period after CCPMOH establishment and the 10-year overview showed upward trends in the hospital-based prevalence of CC cases and a further reduction in age at surgery, likely reflecting the effects of the CCPMOH establishment and providing useful information for further CC studies and a valuable foundation for the prevention and treatment of this cause of childhood blindness.     

Depression among Migrant and Left-Behind Children in China in Relation to the Quality of Parent-Child and Teacher-Child Relationships

The objective of this study was to examine rates of depression among migrant children (MC) and left-behind children (LBC) as compared to non-left-behind children (NLBC) and also to examine the relationship between depression among these children and the quality of their parent-child and teacher-child relationships. This study collected data from a large sample of 3,759 children aged from 8 to 17 years, including 824 who had been left behind by one parent (LBCO), 423 who had been left behind by both parents (LBCB), 568 MC and 1944 NLBC. Children’s Depression Inventory–Short Form was used to measure child depression. Parent-Child Relationship Scale (PCRS) and Teacher-Child Relationship Scale (TCRS) were used to measure the quality of parent-child and teacher-child relationships, respectively. The results showed that the prevalence of depression was 10.5% among NLBC, 13.1% among LBCO, 16.1% among LBCB, and 20.1% among MC. Depression was related to parent-child relationship quality and teacher-child relationship quality. Negative parent-child relationship was more relevant to depression than negative teacher-child relationship among LBCB, while negative teacher-child relationship was the most correlated with depression among MC.     

Determination of 8-oxoguanine in human plasma and urine by high-performance liquid chromatography with electrochemical detection

A highly sensitive and selective method for determining 8-oxoguanine in plasma and urine was developed by high-performance liquid chromatography with electrochemical detection. The compound was separated by gradient elution on a C₁₈ reversed-phase column with a mobile phase of acetonitrile and 0.1 M sodium acetate, pH 5.2. 8-Hydroxy-2′-deoxyguanosine was used as internal standard. 8-Oxoguanine was detected electrochemically by setting the potential to +300 mV vs. Pd reference. The sensitivity of the assay was 22 ng/ml with a signal-to-noise ratio of 7:1. The within-day relative standard deviations for 8-oxoguanine quality control samples with concentrations of 3340, 1340 and 84 ng/ml were 3.6, 4.3 and 5.7% for plasma, and 4.1, 4.6 and 6.2% for urine, respectively. The day-to-day relative standard deviations for the same samples were 3.8, 6.8 and 7.1% for plasma, and 3.9, 7.0 and 7.9% for urine, respectively. The method is designed to study the pharmacokinetics and metabolic fate of O⁶-benzylguanine in a phase I clinical trial. Previously, O⁶-benzyl-8-oxoguanine was identified as the primary metabolite of O⁶-benzylguanine in humans. We now demonstrate that 8-oxoguanine is a further metabolite of O⁶-benzylguanine.     

Passive immunization against murine malaria with an IgG3 monoclonal antibody

Spleen cells of BALB/c mice that were immune to the 17X strain of P. yoelii were fused with P3X63Ag8 myeloma cells. Two hundred fifty-three of 1053 hybrid cells produced antibodies reactive with disrupted 17X parasites in a solid phase radioimmunoassay. One of these antibodies, McAb 302, reacted with the merozoites of the 17X (nonlethal) and 17XL (lethal) variants of P. yoelii. Of greater significance, McAb 302 passively protected mice against challenge infection with the lethal variant. Mice treated with this antibody before infection developed low-grade parasitemia (less than 0.3%) of short duration when challenged with P. yoelii 17XL . In contrast, control mice that had been untreated or injected with ascites fluid lacking McAb 302 uniformly died with fulminating malaria upon challenge with the same parasite. In other experiments, McAb 302 was shown capable of controlling blood parasite levels when administered to mice with patent P. yoelii 17XL infections. Although all control mice died, mice protected with a single dose of McAb 302 ultimately cleared their infections. Regardless of how passive immunization was performed, mice given McAb 302 were resistant to subsequent challenge with P. yoelii 17XL , indicating they had developed significant immunity during their initial controlled infections. McAb 302 also showed pronounced passive protective activity against the nonlethal 17X strain of P. yoelii, which is a parasite of reticulocytes. The protection afforded by McAb 302 was specific, because mice passively immunized with this antibody died when challenged with the unrelated P. vinckei. McAb 302 was shown to possess the IgG3 isotype and precipitated a 230-kd protein plus several smaller polypeptides from metabolically labeled parasite antigen preparation derived from both variants of P. yoelii. It did not react with similar preparations of other murine plasmodial species.