Clinical Translational Research Center Core

Consultations are provided by the Core Directors and staff to help investigators choose the most appropriate metabolic studies to address innovative research questions in human subjects. Core personnel assist investigators in selecting appropriate metabolic variables, biomarkers, recruitment strategies, and outcome measures, and offer guidance for methodology adaptation to human studies.

The CTRC provides consultations on data management and advice on database construction, quality checks, and maintenance, as well as on statistical analyses and interpretation of findings. The CTRC can also provide an independent clinical safety monitoring committee, external to the requesting clinical study, as part of a data and safety monitoring plan.

CTRC staff are available to perform blood draws, sample processing, coordination services, and medical monitoring for studies.

Measures of insulin action and systemic glucose homeostasis: Oral glucose tolerance test (OGTT), Mixed meal tolerance test (MMTT), stepped euglycemic hyperinsulinemic clamp studies including use of tracer techniques, hyperglycemic clamp, frequently sampled intravenous glucose tolerance test, and stepped hyperinsulinemic hypoglycemic clamp for the study of hypoglycemia and counter-regulation.

Measures of body composition: Anthropometrics, Dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance analysis.

Measures of energy balance and expenditure, exercise capacity, and brown fat: Indirect calorimetry, muscle strength and endurance testing, VO2-peak during graded exercise capacity, training, and cooling vests.

Biopsies: Standardized operating procedures and training for muscle, fat, and skin biopsies.

Measures of renal function: Iohexol plasma disappearance for glomerular filtration rate (iGFR) and upcoming measurement of para-aminohippurate (PAH) clearance for renal plasma flow.

Neuropathy testing: Specialty equipment available for neuropathy testing.

Measures of eye health and complications: refraction and visual acuity, dilated fundus examinations, color fundus photography, fluorescein angiography, optical coherence tomography (OCT), OCT angiography, adaptive optics scanning laser ophthalmoscopy, and electroretinography.

Browsable catalog of existing biospecimens and associated clinical data. The CTRC created a browsable catalog of 37 completed or ongoing biospecimen collections at Joslin with associated clinical data, through which DRC investigators can search for existing bio-specimens and/or linked clinical and molecular data that can be used through collaborations with the investigators who established the collections.

Curated DNA collection. DNA samples from different groups of well-characterized individuals are available for studies involving human genetics. The Core repository houses the collection of ~7,100 DNA samples developed through the Molecular Phenotyping and Genotyping Core. Samples, some of which are linked to plasma and serum samples, are organized in several panels and sub-panels (Table 1).

Induced pluripotent cells. Protocols are available for skin-punch biopsy or phlebotomy to procure cells for induced pluripotent stem cell (iPSC) generation with consultation on experimental design and preparation of appropriate IRB documents along with assistance in patient accrual and consent, and help obtaining detailed medical records that are de-identified or coded prior to release to scientific collaborators who use the derived cell lines. The Core’s browsable catalog can be used to locate >130 iPSC lines from individuals with diabetes (including T1D, T2D, and MODY), insulin resistance, related syndromes, and from control subjects, with accompanying phenotypic data.

Table 1. DNA panels available from the CTRC