I searched Pubmed using these search terms (stem cell transplantion OR mesenchymal stem cell transplantation)  AND (diabetes mellitus type 1)  with emphasis on children.    See additional Pubmed references

Chhabra, Preeti, and Kenneth LBrayman. “Stem cell therapy to cure type 1 diabetes: from hype to hope.” Stem Cells Translational Medicine 2.5 (2013):328-36.

Hu, Jianxia, et al. “Long term effects of the implantation of Wharton’s jelly-derived mesenchymal stem cells from the umbilical cord for newly-onset type 1 diabetes mellitus.” endocrine journal 60.3 (2013):347-57.

Stanekzai, Jamil, Esma RIsenovic, and Shaker AMousa. “Treatment options for diabetes: potential role of stem cells.” Diabetes research and clinical practice 98.3 (2012):361-8.

D’Addio, Francesca, et al. “Autologous nonmyeloablative hematopoietic stem cell transplantation in new-onset type 1 diabetes: a multicenter analysis.” Diabetes 63.9 (2014):3041-6.

Zhao, Yong, et al. “New type of human blood stem cell: a double-edged sword for the treatment of type 1 diabetes.” Translational Research 155.5 (2010):211-6.

Domínguez Bendala, Juan, et al. “Concise review: mesenchymal stem cells for diabetes.” Stem Cells Translational Medicine 1.1 (2012):59-63.