Hematology and Clinical Chemistry Reference Ranges for Laboratory-Bred Natal Multimammate Mice (Mastomys natalensis)

Laboratory-controlled physiological data for the multimammate rat (Mastomys natalensis) are scarce, despite this species being a known reservoir and vector for zoonotic viruses, including the highly pathogenic Lassa virus, as well as other arenaviruses and many species of bacteria. For this reason, M. natalensis is an important rodent for the study of host-virus interactions within laboratory settings. Herein, we provide basic blood parameters for age- and sex-distributed animals in regards to blood counts, cell phenotypes and serum chemistry of a specific-pathogen-monitored M. natalensis breeding colony, to facilitate scientific insight into this important and widespread rodent species.     

A recombinant factor VIII A2 domain polypeptide quantitatively neutralizes human inhibitor antibodies that bind to A2

Human antibodies that inactivate coagulation factor VIII (fVIII), known as inhibitors, have been shown by immunoblotting or immunoprecipitation assays to bind predominantly to epitopes within the A2 and/or C2 domains of the fVIII protein. Because these assays simply measure antibody binding, a soluble recombinant polypeptide containing the fVIII A2 domain was used to develop a quantitative inhibitor neutralization assay for antibodies that bound only to A2 by immunoblotting assay. Antibodies from six of eight inhibitor plasmas were fully neutralized by A2 (> or = 90%), whereas two were only partially neutralized. These results established the fVIII inhibitor properties of anti-A2 antibodies. In immunoprecipitation assays, five of the eight inhibitors also had significant levels of anti-light-chain antibody. In one case, this light-chain antibody was shown to have inhibitor activity. Because it did not bind to the C2 domain, this antibody appears to define a new inhibitor epitope within the fVIII light chain. Another inhibitor, which was partially neutralized by A2, was not neutralized by the light chain, even though it contained anti- light-chain antibodies by immunoprecipitation assay. Our results show additional complexities of the immune response to fVIII.     

Weight history from birth through childhood and youth in relation to adult lung function, in Danish juvenile obese and non-obese men

OBJECTIVE: To investigate the associations of birth weight, body mass index (BMI) during childhood and youth, and current BMI with adult lung function. DESIGN: Population-based longitudinal study of juvenile obese and non-obese men, who were identified at draft board examination (age range: 19-27 y) and who participated in a follow-up examination in 1981-1983 (age range: 25-48 y). Birth weight, childhood weight and height measurements from 7 to 13 y of age were obtained from school health records. Current BMI and lung function were assessed at follow-up. SETTING: Copenhagen and adjacent regions, Denmark. SUBJECTS: In total, 193 juvenile obese men at draft board examination and 205 randomly selected nonobese controls from the same population. MAIN OUTCOME MEASURES: Lung function measured by forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC), adjusted for age and height. RESULTS: After adjusting for current BMI, smoking and education, birth weight was positively related to FEV(1), although only with borderline statistical significance. BMI at age 7 y was positively associated with both FEV(1) and FVC, whereas BMI at later ages in childhood and in youth was not associated with these measures. There was a strong negative linear relation between current BMI and lung function among those currently overweight and obese (BMI 25 kg/m(2)), whereas no association was seen in the non-obese (BMI <25 kg/m(2)). CONCLUSION: Our findings confirm the detrimental effect of high current BMI on adult lung function, and further suggest that early childhood growth has a protective influence.     

Improving IQ measurement in intellectual disabilities using true deviation from population norms

Background

Intellectual disability (ID) is characterized by global cognitive deficits, yet the very IQ tests used to assess ID have limited range and precision in this population, especially for more impaired individuals.

Methods

We describe the development and validation of a method of raw z-score transformation (based on general population norms) that ameliorates floor effects and improves the precision of IQ measurement in ID using the Stanford Binet 5 (SB5) in fragile X syndrome (FXS; n = 106), the leading inherited cause of ID, and in individuals with idiopathic autism spectrum disorder (ASD; n = 205). We compared the distributional characteristics and Q-Q plots from the standardized scores with the deviation z-scores. Additionally, we examined the relationship between both scoring methods and multiple criterion measures.

Results

We found evidence that substantial and meaningful variation in cognitive ability on standardized IQ tests among individuals with ID is lost when converting raw scores to standardized scaled, index and IQ scores. Use of the deviation z- score method rectifies this problem, and accounts for significant additional variance in criterion validation measures, above and beyond the usual IQ scores. Additionally, individual and group-level cognitive strengths and weaknesses are recovered using deviation scores.

Conclusion

Traditional methods for generating IQ scores in lower functioning individuals with ID are inaccurate and inadequate, leading to erroneously flat profiles. However assessment of cognitive abilities is substantially improved by measuring true deviation in performance from standardization sample norms. This work has important implications for standardized test development, clinical assessment, and research for which IQ is an important measure of interest in individuals with neurodevelopmental disorders and other forms of cognitive impairment.     

Acceptability and feasibility of CyberSenga: an Internet-based HIV-prevention program for adolescents in Mbarara,Uganda

Capitalizing on emerging data suggesting that HIV-preventive behaviors can be positively affected by Internet-based programs, we developed and tested CyberSenga, an Internet-based, comprehensive sexuality education program for adolescents in Mbarara, Uganda. Three hundred and sixty-six secondary school students were randomly assigned to either the five-lesson program (+ booster) or a treatment-as-usual control. At three-month follow-up, intervention participants provided feedback on the program acceptability. Six focus groups with intervention participants were additionally conducted after the final follow-up at 6 months. Data support a hypothesis of feasibility: despite schedule interruptions, 95% of intervention participants completed all the five modules; only 17% deviated from the once-a-week intended delivery schedule. Internet service was uninterrupted during the field period and, in general, the technology performed to specifications. The intervention also appears to be acceptable: 94% of intervention youth somewhat or strongly agreed that they learned a lot and 93% said they were somewhat or very likely to recommend the program. Although more than two in three youth somewhat or strongly agreed that the program talked too much about sex (70%) and condoms (75%), 89% somewhat or strongly disagreed that “I do not think kids like me should do the CyberSenga program.” Feedback from focus group participants further suggested that the content was generally acceptable and did not contradict local norms in most cases. In fact, despite concerns from some local stakeholders to the contrary, information about condoms did not appear to be confusing or contradictory for youth who were abstinent. Nonetheless, some of the sexual topics seemed to be unfamiliar or uncomfortable for some participants – particularly brief references to oral and anal sex. Together, both qualitative and quantitative data suggest that the program is a feasible and acceptable way of delivering HIV preventive information to both sexually experienced and inexperienced adolescents in Mbarara, Uganda.     

Detection and clinical features of hepatitis C virus type 6 infections in blood donors from Hong Kong

The genotype distribution of hepatitis C virus (HCV) was investigated in 212 viraemic blood donors from Hong Kong. A subset of the samples was investigated using three different genotyping assays to establish the accuracy of each in this population. These assays were restriction fragment length polymorphism (RFLP) of amplified 5′ noncoding region (5′NCR) sequences, RFLP of the core region, and a serotyping assay using peptides from two antigenic regions of NS4. Genotypes detected in Hong Kong blood donors were 1a (6.2%), 1b (58.8%), 2a (1.4%), 2b (1.4%), 3a (1.9%), and 6a (27.0%). All genotyping assays produced concordant results. No evidence was obtained for the presence of type 6 group variants recently identified in Southeast Asia, other than type 6a. A serotyping assay based upon the detection of type-specific antibody to epitopes in NS4 produced similar results to the genotyping assays (98% concordance), but a reduced sensitivity (75%) compared with genotyping methods. Sequence variation in NS4 was not the cause of the reduced rate of detection of type 6 antibody in this population. Eighty-four percent donors infected with type 6a were male, compared to 75% donors infected with type 1b. The median alanine transaminase (ALT) level in type 6 infected donors was lower than in type 1b, (43.8 and 51.1 U/l, respectively) although these values were not statistically significant (P = 0.094). There was no significant difference between the ages of donors infected with types 1b and 6a. Risk factors for HCV infection in the blood donors included blood transfusion, intravenous drug abuse, and tattooing. A significantly greater number of donors infected with HCV-6a reported a history of drug abuse (66%) than donors infected with HCV-1b (7%). © 1996 Wiley-Liss, Inc.     

Initiation and Continuation of DNA Replication Are Not Associated with the Nuclear Envelope in Mammalian Cells

For determination of whether DNA replication is initiated at the nuclear envelope, synchronized Chinese hamster ovary cells labeled with [(3)H]thymidine were examined by electron microscope radioautography. The cells were synchronized initially by mitotic shake-off and held at the G(1)-S border by 5-fluorodeoxyuridine plus amethopterin. Cells were fixed at 1, 5, 10, and 30 min after the inhibitors were counteracted with [(3)H]thymidine. Radioautographic silver grains in each case were present over the more central parts of nuclei and were generally absent from the region of the nuclear envelope. We conclude that neither initiation nor continuation of DNA replication is associated with the nuclear envelope.     

Intracellular unesterified arachidonic acid signals apoptosis

Cyclooxygenase-2 (COX-2) is up-regulated in many cancers and is a rate-limiting step in colon carcinogenesis. Nonsteroidal antiinflammatory drugs, which inhibit COX-2, prevent colon cancer and cause apoptosis. The mechanism for this response is not clear, but it might result from an accumulation of the substrate, arachidonic acid, an absence of a prostaglandin product, or diversion of the substrate into another pathway. We found that colon adenocarcinomas overexpress another arachidonic acid-utilizing enzyme, fatty acid-CoA ligase (FACL) 4, in addition to COX-2. Exogenous arachidonic acid caused apoptosis in colon cancer and other cell lines, as did triacsin C, a FACL inhibitor. In addition, indomethacin and sulindac significantly enhanced the apoptosis-inducing effect of triacsin C. These findings suggested that unesterified arachidonic acid in cells is a signal for induction of apoptosis. To test this hypothesis, we engineered cells with inducible overexpression of COX-2 and FACL4 as "sinks" for unesterified arachidonic acid. Activation of the enzymatic sinks blocked apoptosis, and the reduction of cell death was inversely correlated with the cellular level of arachidonic acid. Inhibition of the COX-2 component by nonsteroidal antiinflammatory drugs restored the apoptotic response. Cell death caused by exposure to tumor necrosis factor alpha or to calcium ionophore also was prevented by removal of unesterified arachidonic acid. We conclude that the cellular level of unesterified arachidonic acid is a general mechanism by which apoptosis is regulated and that COX-2 and FACL4 promote carcinogenesis by lowering this level.