Abnormal TREC-Based Newborn Screening Test in a Premature Neonate with Massive Perivillous Fibrin Deposition of the Placenta.

Severe combined immunodeficiency (SCID), a primary immunodeficiency arising from variable defects in lymphocyte development and survival, is characterized by significant deficiency of thymus derived (T-) lymphocytes and variable defects in the B-lymphocyte population. Newborn screening for SCID is based on detection of low numbers of T-cell receptor excision circles (TRECs) by real time quantitative PCR (RT-qPCR). This screening allows for early identification of individuals with SCID and other disorders characterized by T-lymphopenia. Higher rates of abnormal screens are commonly seen in premature and critically ill neonates, often representing false positives. It is possible that many abnormal screens seen in these populations are result of conditions that are characterized by systemic inflammation or stress, possibly in the context of stress-induced thymic involution. We present a case of a male infant delivered at 27 weeks, 6 days of gestation, with severe intrauterine growth restriction who had an abnormal TREC screen and a massive perivillous fibrin deposition (MPFD) of the placenta. This association has not been reported previously. We are raising the awareness to the fact that conditions, such as MPFD, that can create adverse intrauterine environment are capable of causing severe stress-induced thymic involution of the fetus which can present with abnormal TREC results on newborn screening.

Anesthetic management of a patient with 3-methylcrotonyl-CoA carboxylase deficiency.

Patients with inborn errors of metabolism require special considerations in perioperative care. In the following case report, we describe the successful management of a patient with 3-methylcrotonyl-CoA carboxylase deficiency, a deficit that causes a secondary carnitine deficiency and impaired beta oxidation. Patients may have significant underlying cardiomyopathy, and are at risk for metabolic decompensation, acidosis, and hypoglycemia during periods of stress.

Quantitation of cytochrome c release from rat liver mitochondria.

The apoptogenic protein cytochrome c can be quantitated by reverse-phase HPLC, but this method is not utilized by those who investigate mechanisms of cell death. Here, we extend the sensitivity of the method to exceed that available from immunogenic approaches and report specific procedures for applying the method to preparations of intact mitochondria, and to supernatants and pellets that arise from mitochondrial incubations. The detection limit corresponds to 0.6% of total cytochrome c found in 100 microg of rat liver mitochondrial protein, or to all of the cytochrome c that is expected in approximately 6000 hepatocytes. A single determination can be completed in 20 min, compared to a time scale of days for Western blotting methods, or hours for ELISA-based methods. The procedures are illustrated by experiments that determine the amount of cytochrome c released following the mitochondrial permeability transition as a function of medium ionic strength, and by long-term incubations of intact mitochondria in the presence and absence of an exogenous oxidizable substrate. Swelling and the release of adenylate kinase activity have been determined simultaneously to show how the data can be applied to evaluate the role of outer membrane disruption in mechanisms that release cytochrome c.