Liver development is restored by blastocyst complementation of HHEX knockout in mice and pigs.

BACKGROUND: There are over 17,000 patients in the US waiting to receive liver transplants, and these numbers are increasing dramatically. Significant effort is being made to obtain functional hepatocytes and liver tissue that can for therapeutic use in patients. Blastocyst complementation is a challenging, innovative technology that could fundamentally change the future of organ transplantation. It requires the knockout (KO) of genes essential for cell or organ development in early stage host embryos followed by injection of donor pluripotent stem cells (PSCs) into host blastocysts to generate chimeric offspring in which progeny of the donor cells populate the open niche to develop functional tissues and organs. METHODS: The HHEX gene is necessary for proper liver development. We engineered loss of HHEX gene expression in early mouse and pig embryos and performed intraspecies blastocyst complementation of HHEX KO embryos with eGFP-labeled PSCs in order to rescue the loss of liver development. RESULTS: Loss of HHEX gene expression resulted in embryonic lethality at day 10.5 in mice and produced characteristics of lethality at day 18 in pigs, with absence of liver tissue in both species. Analyses of mouse and pig HHEX KO fetuses confirmed significant loss of liver-specific gene and protein expression. Intraspecies blastocyst complementation restored liver formation and liver-specific proteins in both mouse and pig. Livers in complemented chimeric fetuses in both species were comprised of eGFP-labeled donor-derived cells and survived beyond the previously observed time of HHEX KO embryonic lethality. CONCLUSIONS: This work demonstrates that loss of liver development in the HHEX KO can be rescued via blastocyst complementation in both mice and pigs. This complementation strategy is the first step towards generating interspecies chimeras for the goal of producing human liver cells, tissues, and potentially complete organs for clinical transplantation.

Using disease progression models as a tool to detect drug effect.

Generally, information required for approval of new drugs is dichotomous in that the drug is either efficacious and safe or not. Consequently, the purpose of most confirmatory clinical trials is to test the null hypothesis. The primary reasons for designing hypothesis testing trials are to provide the information required for approval using analyses techniques that are relatively straightforward and free of apparent assumptions. However, the information required for approval is very different from that used by prescribers for decision making. In the clinic, decisions must be made about dose adjustment for individual patients in the presence of additional therapies and co-morbidities. Choice of drug and dosing regimen is therefore a classical risk to benefit decision that is often poorly informed from the results of confirmatory trials. Therefore, providing answers to the more difficult question of how to use the drug in a clinical setting is essential.

Measuring the mood of seventh-grade students with the MAACL-R6.

Recently, the Multiple Affect Adjective Check List-Revised was modified to include only those items designated as at or below the sixth-grade reading level (MAACL-R6). The present study investigated the reliability and validity of the state and trait forms of the MAACL-R6 in a sample of seventh-grade public school students. High internal consistency and adequate validity were found for both forms. Test-retest reliability was higher for trait than for state. It was concluded that the MAACL-R6 is appropriate for use in research with seventh-grade students.

Adolescent norms for the MAACL-R6.

The reliability and validity of the trait form of the sixth-grade version of the Multiple Affect Adjective Check List-Revised (MAACL-R6) have been demonstrated for sixth- and seventh-grade public school students and patients at a mental health clinic. In this study, norms for the MAACL-R6 with middle and high school students (grades 6-12) were investigated.

Measuring the short-term mood of adolescents: reliability and validity of the state form of the Depression Adjective Check Lists.

Adequate reliability (internal consistency, and alternate form), and validity (concurrent, convergent, and discriminant) of the state version of Set 1 (lists A, B, C, D) and Set 2 (lists E, F, G) of the Depression Adjective Check Lists with two adolescent samples: F = 35, M = 29; F = 294, M = 244) were demonstrated. The lists also were shown to be sufficiently sensitive for use in measuring short-term mood. Significant grade effect was found on two of the lists of Set 1 and a significant sex effect was found on each of the lists of Set 2.