POLG DNA testing as an emerging standard of care before instituting valproic acid therapy for pediatric seizure disorders.

PURPOSE: To review our clinical experience and determine if there are appropriate signs and symptoms to consider POLG sequencing prior to valproic acid (VPA) dosing in patients with seizures. METHODS: Four patients who developed VPA-induced hepatotoxicity were examined for POLG sequence variations. A subsequent chart review was used to describe clinical course prior to and after VPA dosing. RESULTS: Four patients of multiple different ethnicities, age 3-18 years, developed VPA-induced hepatotoxicity. All were given VPA due to intractable partial seizures. Three of the patients had developed epilepsia partialis continua. The time from VPA exposure to liver failure was between 2 and 3 months. Liver failure was reversible in one patient. Molecular studies revealed homozygous p.R597W or p.A467T mutations in two patients. The other two patients showed compound heterozygous mutations, p.A467T/p.Q68X and p.L83P/p.G888S. Clinical findings and POLG mutations were diagnostic of Alpers-Huttenlocher syndrome. CONCLUSION: Our cases underscore several important findings: POLG mutations have been observed in every ethnic group studied to date; early predominance of epileptiform discharges over the occipital region is common in POLG-induced epilepsy; the EEG and MRI findings varying between patients and stages of the disease; and VPA dosing at any stage of Alpers-Huttenlocher syndrome can precipitate liver failure. Our data support an emerging proposal that POLG gene testing should be considered in any child or adolescent who presents or develops intractable seizures with or without status epilepticus or epilepsia partialis continua, particularly when there is a history of psychomotor regression.

The functional and structural interactions between v-{\it mos\/} proteins and cell cycle control elements

The v-mos gene of Moloney murine sarcoma virus (Mo-MuSv) encodes a serine/threonine protein kinase capable of inducing cellular transformation. The c-mos protein is an important cell cycle regulator that functions during meiotic cell division cycles in germ cells. The overall function of c-mos in controlling meiosis is becoming better understood but the role of v-mos in malignant transformation of cells is largely unknown.^ In this study, v-mos protein was shown to be phosphorylated by M phase kinase in vitro and in vivo. The kinase activity and neoplastic transforming ability of v-mos is positively regulated by the phosphorylation. Together with the earlier finding of activation of M phase kinase by c-mos, these results raise the possibility of mutual regulation between M phase kinase and mos kinases.^ In addition to its functional interaction with the M phase kinase, the v-mos protein was shown to be present in the same protein complex with a cyclin-dependent kinase (cdk). In addition, an antibody that recognizes the cdk proteins was shown to co-precipitate the v-mos proteins in the interphase and mitotic cells transformed by p85$\sp{\rm gag-mos}$. Cdk proteins have been shown to be associated with nonmitotic cyclins which are potential oncogenes. The perturbation of cdk kinase or the activation of non-mitotic cyclins as oncogenes by v-mos could contribute directly to v-mos induced cellular transformation. v-mos proteins were also shown to interact with tubulin and vimentin, the essential components of microtubules and type IV intermediate filaments, respectively. The organizations of both microtubules and intermediate filaments are cell cycle-regulated. These results suggest that the v-mos kinase could be directly involved in inducing morphological changes typically seen in transformed cells.^ The interactions between the v-mos protein and these cell cycle control elements in regards to v-mos induced neoplastic transformation are discussed in detail in the text. ^

Mechanisms of apoptosis in bleomycin-induced lung injury: Implications for pulmonary fibrosis

Chronic inflammation leading to pulmonary fibrosis develops in response to environmental pollutants, radiotherapy, or certain cancer chemotherapeutic agents. Studies have shown that several cell types accumulate during the inflammatory process, but little information is known about what actually triggers and stimulates persistent inflammation culminating in fibrosis. As a first step in defining the events that precipitate inflammation in the lung, the biological mechanism(s) mediating apoptosis and cellular targets must be identified. The purpose of this study was to determine the molecular mechanism(s) of bleomycin-induced apoptosis in the lung using mice deficient in genes that we hypothesized to play a key role in apoptosis. Intratracheal administration of bleomycin led to caspase-mediated DNA fragmentation characteristic of apoptosis. The effects of bleomycin were associated with translocation of p53 from the cytosol to the nucleus only in alveolar macrophages that had been exposed to the drug in vivo, suggesting that the lung microenvironment regulated p53 activation. Experiments with a thiol antioxidant (N-acetylcysteine) in vivo and nitric oxide donors in vitro confirmed that reactive oxygen species were required for p53 activation. A specific role for NO was demonstrated in experiments with iNOS−/− macrophages, which failed to demonstrate nuclear p53 localization after in vivo bleomycin exposure. Strikingly, rates of bleomycin-induced apoptosis were at least two-fold higher in iNOS−/− and p53−/− C57BL/6 mice compared to wild-type controls. Laser Scanning Cytometry (LSC) analysis revealed that bleomycin exposure resulted in a 2-fold induction in Fas and FasL expression in wild-type mice but not iNOS−/− or p53−/− mice. Experiments using gld mice confirmed that the Fas/FasL pathway was the primary mechanism of bleomycin-induced apoptosis in the lung. LSC-mediated analysis indicated that bleomycin exposure resulted in a 2-fold induction in Bax expression in iNOS−/− and P53−/− mice but not wild-type mice. Furthermore, LSC analysis revealed that bleomycin exposure induced a 3-fold increase in thrombospondin expression in wild-type mice. However, thrombospondin was not expressed in either the iNOS−/− or p53−/− mice, implicating a thrombospondin-mediated apoptotic cell clearance mechanism in the lung. Together, these results demonstrate that iNOS and p53 positively regulate apoptosis via the Fas/FasL pathway and mediate a novel apoptosis-suppressing pathway in the lung. ^

The Colic Clinic---a comprehensive program evaluation

Child abuse correlated with excessive infant crying affects millions of families each year, with consequences of the abuse lasting a lifetime. The University Of Texas School Of Medicine's Colic Clinic is currently in the early stages of testing Dr. Harvey Karp's combinatorial soothing technique for infants called "The Happiest Baby on the Block". In order to gauge the program's potential effectiveness, the Colic Clinic Protocol was examined in order to assess the applicability of the intervention to known causal factors of child abuse associated with excessive infant crying. ^ This evaluation also carried out an anticipated cost-benefit breakout analysis for the implementation of the intervention for 100 children and compared the cost of the program implementation to the cost associated with a single instance of child abuse. The analysis revealed that while accounting for materials, advertising, salaried personnel and other overhead expenses, the cost to implement the intervention was less than half the cost of the medical treatment associated with a single victim of whiplash-shaken infant syndrome. ^ Although the program is still in its early evaluative phase, the future implications of this work are extensive. If this intervention is revealed to be relevant and cost effective, it will precipitate sweeping changes in medical education and training, public health detection and prevention programs, and law enforcement.^

Intensive care unit utilization among patients with cancer at the end of life

Over the last 2 decades, survival rates in critically ill cancer patients have improved. Despite the increase in survival, the intensive care unit (ICU) continues to be a location where end-of-life care takes place. More than 20% of deaths in the United States occur after admission to an ICU, and as baby boomers reach the seventh and eighth decades of their lives, the volume of patients in the ICU is predicted to rise. The aim of this study was to evaluate intensive care unit utilization among patients with cancer who were at the end of life. End of life was defined using decedent and high-risk cohort study designs. The decedent study evaluated characteristics and ICU utilization during the terminal hospital stay among patients who died at The University of Texas MD Anderson Cancer Center during 2003-2007. The high-risk cohort study evaluated characteristics and ICU utilization during the index hospital stay among patients admitted to MD Anderson during 2003-2007 with a high risk of in-hospital mortality. Factors associated with higher ICU utilization in the decedent study included non-local residence, hematologic and non-metastatic solid tumor malignancies, malignancy diagnosed within 2 months, and elective admission to surgical or pediatric services. Having a palliative care consultation on admission was associated with dying in the hospital without ICU services. In the cohort of patients with high risk of in-hospital mortality, patients who went to the ICU were more likely to be younger, male, with newly diagnosed non-metastatic solid tumor or hematologic malignancy, and admitted from the emergency center to one of the surgical services. A palliative care consultation on admission was associated with a decreased likelihood of having an ICU stay. There were no differences in ethnicity, marital status, comorbidities, or insurance status between patients who did and did not utilize ICU services. Inpatient mortality probability models developed for the general population are inadequate in predicting in-hospital mortality for patients with cancer. The following characteristics that differed between the decedent study and high-risk cohort study can be considered in future research to predict risk of in-hospital mortality for patients with cancer: ethnicity, type and stage of malignancy, time since diagnosis, and having advance directives. Identifying those at risk can precipitate discussions in advance to ensure care remains appropriate and in accordance with the wishes of the patient and family.^