Pica: The Mysterious Eating Disorder

Background. ‘Pica’ is the Latin word for magpie, a bird that ingests inedible substances. The DSM-V defines pica as a disorder of persistent eating of nonnutritive, nonfood substances over a period of at least one month. Although pica is a disorder that affects a widespread population, it is seen as a social anomaly which prevents patients from admitting their behavior. As the behavior continues unnoticed and untreated, patients will experience the adverse effects of ingesting foreign materials. Thus, healthcare providers and family members should educate themselves on pica’s etiologies and manifestations to prevent complications and avoid unnecessary hospitalizations. Methods. The data was obtained using the Google search engine. Search terms used were: (a) history of pica, (b) diagnosing pica, and (c) treating pica for the years 1990-2018. The DSM-V was referenced for the medical definition of pica. Results. The few studies done on pica have drawn inconclusive data. While the percentage of the population that suffers from pica is unknown, common risk factors are: (a) nutritional deficiencies such as iron-deficiency anemia, (b) low socioeconomic status due to the inaccessibility of nutritious foods, (c) nondiscriminating oral behaviors in those with intellectual disabilities, and (d) an underlying biochemical behavior. No specific laboratory tests are indicated to evaluate pica. Providers have found success in diagnosing pica through: (a) dietary history, (b) interviewing family members, and (c) a high index of suspicion. Without verbal admittance, the only way to evaluate pica is to test for nutrient deficiencies and identify ingested materials using: (a) abdominal radiography, (b) barium enema, and (c) upper GI endoscopy. Although this disorder is seen most frequently in children and the developmentally disabled, it is also observed in pregnant women who ingest starch to quell morning sickness. Pica patients have been reported to ingest a variety of substances including, but not limited to: (a) clay, (b) dirt, (c) stones, (d) cigarette butts, and, (e) lead paint and soil. Lead poisoning affects the central nervous system and leads to irreversible neurological damage; it is also associated with decreased renal function and hypertension. Conclusions and Recommendations. Serious complications of pica include obstruction or perforation of the gastrointestinal tract, and lead poisoning. Early detection of lead toxicity is vital to prevent systemic complications. There is no definitive management for pica but current therapies include (a) nutrient replacement, (b) behavioral therapy, and (c) dopaminergic function enhancing medications such as olanzapine. Since very little is known about pica, it would be beneficial to perform longitudinal studies to observe and educate the general public on the long-term effects of pica so they understand that this behavior is more than a habit but one with serious consequences. Pica is a condition that requires a multidisciplinary approach utilizing physicians, psychologists, and social workers and it is recommended that healthcare providers treating high-risk patients ask appropriate primary and exploratory questions during physical exams. While many may be discouraged at the lack of data on pica, it should be seen as an opportunity to promote its clinical importance through awareness and education

Ribosomal proteins produced in excess are degraded by the ubiquitin-proteasome system

Ribosome assembly is an essential process that consumes prodigious quantities of cellular resources. Ribosomal proteins cannot be overproduced in Saccharomyces cerevisiae because the excess proteins are rapidly degraded. However, the responsible quality-control (QC) mechanisms remain poorly characterized. Here, we demonstrate that overexpression of multiple proteins of the small and large yeast ribosomal subunits is suppressed. Rpl26 overexpressed from a plasmid can be detected in the nucleolus and nucleoplasm, but it largely fails to assemble into ribosomes and is rapidly degraded. However, if the endogenous RPL26 loci are deleted, plasmid-encoded Rpl26 assembles into ribosomes and localizes to the cytosol. Chemical and genetic perturbation studies indicate that overexpressed ribosomal proteins are degraded by the ubiquitin-proteasome system, and not by autophagy. Inhibition of the proteasome led to accumulation of multiple endogenous ribosomal proteins in insoluble aggregates, consistent with the operation of this QC mechanism in the absence of ribosomal protein overexpression. Our studies reveal that ribosomal proteins that fail to assemble into ribosomes are rapidly distinguished from their assembled counterparts and are ubiquitinated and degraded within the nuclear compartment

Using whole-genome sequences of the LG/J and SM/J inbred mouse strains to prioritize quantitative trait genes and nucleotides

Background The laboratory mouse is the most commonly used model for studying variation in complex traits relevant to human disease. Here we present the whole-genome sequences of two inbred strains, LG/J and SM/J, which are frequently used to study variation in complex traits as diverse as aging, bone-growth, adiposity, maternal behavior, and methamphetamine sensitivity. Results We identified small nucleotide variants (SNVs) and structural variants (SVs) in the LG/J and SM/J strains relative to the reference genome and discovered novel variants in these two strains by comparing their sequences to other mouse genomes. We find that 39% of the LG/J and SM/J genomes are identical-by-descent (IBD). We characterized amino-acid changing mutations using three algorithms: LRT, PolyPhen-2 and SIFT. We also identified polymorphisms between LG/J and SM/J that fall in regulatory regions and highly informative transcription factor binding sites (TFBS). We intersected these functional predictions with quantitative trait loci (QTL) mapped in advanced intercrosses of these two strains. We find that QTL are both over-represented in non-IBD regions and highly enriched for variants predicted to have a functional impact. Variants in QTL associated with metabolic (231 QTL identified in an F16 generation) and developmental (41 QTL identified in an F34generation) traits were interrogated and we highlight candidate quantitative trait genes (QTG) and nucleotides (QTN) in a QTL on chr13 associated with variation in basal glucose levels and in a QTL on chr6 associated with variation in tibia length. Conclusions We show how integrating genomic sequence with QTL reduces the QTL search space and helps researchers prioritize candidate genes and nucleotides for experimental follow-up. Additionally, given the LG/J and SM/J phylogenetic context among inbred strains, these data contribute important information to the genomic landscape of the laboratory mouse

Alleviating Polarity-Conflict at the Heterointerfaces of KTaO\u3csub\u3e3\u3c/sub\u3e/GdScO\u3csub\u3e3\u3c/sub\u3e Polar Complex-Oxides

We have synthesized and investigated the heterointerfaces of KTaO3 (KTO) and GdScO3 (GSO), which are both polar complex-oxides along the pseudo-cubic [001] direction. Since their layers have the same, conflicting net charges at interfaces, i.e., KO(−1)/ScO2(−1) or TaO2(+1)/GdO(+1), forming the heterointerface of KTO/GSO should be forbidden due to strong Coulomb repulsion, the so-called polarity conflict. However, we have discovered that atomic reconstruction occurs at the heterointerfaces between KTO thin-films and GSO substrates, which effectively alleviates the polarity conflict without destroying the hetero-epitaxy. Our result demonstrates one of the important ways to create artificial heterostructures from polar complex-oxides