Imaging Stewardship: Triage for Neuroradiology MR During Limited-Resource Hours

OBJECTIVES

To decrease call burden on pediatric neuroradiologists, we developed guidelines for appropriate use of MR overnight. These guidelines were implemented using triage by in-house generalist pediatric radiologists. Process measures and balancing measures were assessed during implementation.

METHODS

For this improvement project, interdepartmental consensus guidelines were developed using exploratory mixed-methods design. Implementation of triage used plan-do-study-act cycles. Process measures included reduction in the number of telephone calls, frequency of calls, triage decisions, and number and type of examinations ordered. Balancing measures included burden of time and effort to the generalist radiologists. Differences in examination orders between implementation intervals was assessed using Kruskal-Wallis, with significance at P < .05.

RESULTS

Consensus defined MR requests as "do," "defer," or "divert" (to CT). Guidelines decreased neuroradiologist calls 74% while adding minimal burden to the generalist radiologists. Most nights had zero or one triage request and the most common triage decision was "do," and the most common examination was routine brain MR. Number of MR ordered and completed overnight did not significantly change with triage.

DISCUSSION

Multidisciplinary consensus for use of pediatric neurological MR during limited resource hours overnight is an example of imaging stewardship that decreased the burden of calls and burnout for neuroradiologists while maintaining a comparable level of service to the ordering clinicians.

The role of ultrasound in necrotizing enterocolitis

Ultrasound has proved to be a useful modality for enhancing the diagnostic accuracy of necrotizing enterocolitis and associated complications. The standard imaging algorithm for evaluating necrotizing enterocolitis includes radiographs and clinical symptoms, the combination of which constitutes the Bell criteria. Major limitations of using the Bell criteria for diagnosing and clinically managing necrotizing enterocolitis include low diagnostic accuracy of radiographs and nonspecific symptomatology of preterm infants. In this regard, US can offer additional insights into bowel health by helping to characterize bowel motility, echogenicity, thickness, pneumatosis and perfusion. Extramural findings such as portal venous gas, nature and extent of ascites, and pneumoperitoneum can also be assessed. Recently, contrast-enhanced US was explored in a case series of preterm bowel disease and its diagnostic utility warrants further investigation. This article reviews the US features of necrotizing enterocolitis and highlights the role of US as a complement to radiographs, as well as the emerging use of contrast-enhanced US in necrotizing enterocolitis.

Clinical and radiological characteristics of e-cigarette or vaping product use associated lung injury

PURPOSE

E-cigarette or vaping product use associated lung injury (EVALI) has received national attention as an epidemic resulting in cases of significant morbidity and mortality. We aim to present the clinical and imaging findings in adolescents with pulmonary symptoms from suspected EVALI.

METHODS

Chest radiographs and CTs of adolescents (< 19 years) with acute pulmonary symptoms and history of vaping were reviewed by two radiologists in consensus. Clinical presentation and laboratory data were derived from the electronic medical records including pulmonary function tests (PFTs).

RESULTS

Eleven patients were identified (9 male, mean 16.6 years). The most common presentation was progressive, subacute respiratory distress with abdominal pain. All but one of the patients tested positive for tetrahydrocannabinol. Chest radiograph features were notable for interstitial pattern of opacities (91%) and basilar abnormalities (82%). CT features were notable for ground-glass opacities (89%), interstitial opacities (78%), and subpleural sparing (67%). Eight patients underwent PFTs. Six had diffusing capacity measurement, which demonstrated impaired diffusion in 3 (50%). All patients received supportive treatment with supplemental oxygen and corticosteroids.

CONCLUSION

Adolescents with suspected EVALI commonly present with subacute respiratory distress with abdominal pain. Imaging findings include ground-glass opacities, subpleural sparing, and basilar opacities, most consistent with organizing pneumonia or hypersensitivity pneumonitis. Recognition of the common imaging findings may have significant patient management implications, especially if the diagnosis is not suspected clinically. The lung function effects of vaping are consistent with mildly reduced airflow, which improves on follow-up testing, and reduced diffusion capacity, which, concerningly, does not improve.

Single-Arm Resistance Training Study to Determine the Relationship between Training Outcomes and Muscle Growth Factor mRNAs in Older Adults Consuming Numerous Medications and Supplements

OBJECTIVES

Determine if the muscle mRNA levels of three growth factors (insulin-like growth factor-1 [IGF1], ciliary neurotropic factor [CNTF], and vascular endothelial growth factor-D [VEGFD]) are correlated with muscle size and strength gains from resistance exercise while piloting a training program in older adults taking medications and supplements for age-associated problems.

DESIGN

Single-arm prospective study.

SETTING

US Veterans Affairs hospital.

PARTICIPANTS

Older (70±6 yrs) male Veterans (N=14) of US military service.

INTERVENTION

Thirty-five sessions of high-intensity (80% one-rep max) resistance training including leg press, knee curl, and knee extension to target the thigh muscles.

MEASUREMENTS

Vastus lateralis biopsies were collected and body composition (DEXA) was determined pre- and post-training. Simple Pearson correlations were used to compare training outcomes to growth factor mRNA levels and other independent variables such as medication and supplement use.

RESULTS

Average strength increase for the group was ≥ 25% for each exercise. Subjects averaged taking numerous medications (N=5±3) and supplements (N=2±2). Of the growth factors, a significant correlation (R>0.7, P≤0.003) was only found between pre-training VEGFD and gains in lean thigh mass and extension strength. Mass and strength gains were also correlated with use of α-1 antagonists (R=0.55, P=0.04) and pre-training lean mass (R=0.56, P=0.04), respectively.

CONCLUSIONS

Muscle VEGFD, muscle mass, and use of α-1 antagonists may be predisposing factors that influence the response to training in this population of older adults but additional investigation is required to determine if these relationships are due to muscle angiogenesis and blood supply.

The Interrelationships among albumin, nutrient intake, and inflammation in elderly recuperative care patients

OBJECTIVES

To examine the interrelationships among low serum albumin, nutritional depletion, and ongoing inflammation in older patients recovering from illness.

DESIGN

A prospective cohort study.

SETTING

A transitional care unit (TCU) within a Department of Veterans Affairs hospital nursing home care unit.

PARTICIPANTS

275 older veterans (mean age=78.9 ± 7.5y, 99% male) admitted for recuperative care and rehabilitation.

MEASUREMENTS

At admission and discharge (median LOS 24d, IQR 16 to 44d), each subject completed a comprehensive standardized evaluation including a nutritional assessment and measurement of serum albumin, C-reactive protein (CRP), interleukin-6 (IL-6) and its soluble receptor, and tumor necrosis factor-alpha (TNF-α) and its soluble receptors (sTNF-RI and II). Complete nutrient intake assessments (calorie counts) were performed daily.

RESULTS

Both the discharge albumin and the change in albumin (discharge minus admission) were strongly and inversely correlated with various indicators of inflammation, particularly CRP and IL-6. Change in CRP was the strongest correlate of change in albumin (R2 = 0.21, P<.001) and discharge IL-6 the strongest correlate of discharge albumin (R2 = 0.21, P<.001). Nutrient intake also correlated with albumin and its change, but entered the multivariable models after inflammatory indicators and explained a smaller portion of the variance. Although there were significant interactions between time and both nutrient intake and inflammation, the relative importance of inflammation as a potential determinant of the serum albumin concentration appeared to remain unchanged with longer periods of observation.

CONCLUSIONS

Among elderly patients admitted to a TCU, inflammation appears to be a more powerful determinant of albumin and its change during the hospitalization than is nutrient intake. Further study is needed to prove causality and to determine whether the relative importance of inflammation on the albumin concentration diminishes with more prolonged periods of observation.

The CA 125 gene: an extracellular superstructure dominated by repeat sequences

CA 125 has long presented problems to both clinicians and investigators because there was no definitive information on its structure and function. Here, we describe our work on cloning the CA 125 gene with the anticipation that such information will provide the basis for understanding its structure and its physiologic role in both normal and malignant tissues. The CA 125 protein core is composed of a short cytoplasmic tail, a transmembrane domain and an extraordinarily large glycosylated extracellular structure. This structure is dominated by a repeat domain composed of 156 amino acid repeat units which encompass the epitope binding sites. The molecule also includes an amino terminal domain of serine/threonine-rich sequences which would account for most of the O-glycosylation known to be present in CA 125. CA 125 is an unusually large transmembrane glycoprotein. Its release from the surface of the cell is most probably dependent on cytoplasmic phosphorylation followed by proteolytic cleavage. The extracellular domain is characterized by a large number of repeat units (probably 60+) which encompass an interactive disulfide bridged cysteine-loop and the site of OC125 and M11 binding. Sequencing the gene provides us with the ability to initiate the quest to understand the biological function of CA 125.

InternetQuestion and Answer (iQ&A): a Web-based survey technology

This paper presents InternetQuestion and Answer, a Web-based survey development and implementation technology, which has been designed for constructing on-line surveys for educational, medical, or administrative purposes. The system, called iQ&A, is a three-tiered database-backed Web system that has been developed to support a wide range of applications. Surveys are considered as general data collection instruments and include a wide field of application. iQ&A facilitates rapid survey construction and administration which is ideally suited for biomedical research as well as other research and educational activities. Full report management capabilities provide the survey publisher on-line access to current information on survey responses. Current implementations of this technology in the areas of biomedical applications of clinical trials, longitudinal research, and other research-related systems are presented. Further refinement of the current system should lead to a powerful general survey technology for broad-based applications.

Yeast mutants of glucose metabolism with defects in the coordinate regulation of carbon assimilation

The enzymes of the glyoxylate cycle and gluconeogenesis are tightly regulated by transcriptional, posttranscriptional, and posttranslational mechanisms in Saccharomyces cerevisiae. We have previously identified four genes, ACN8, ACN9, ACN17, and ACN18, whose mutant phenotype includes two- to fourfold elevated levels of enzymes of the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism. The affected enzymes are elevated on nonfermentable carbon sources but are still fully repressed by glucose. Catabolite inactivation of the cytosolic malate dehydrogenase is not affected in the mutants. Instead, the phenotype appeared to be manifested primarily at the level of transcription. The ACN8, ACN17, and ACN18 genes were isolated by functional complementation of the respective mutant's inability to utilize acetate as a carbon and energy source, and these genes were shown to encode subunits of metabolic enzymes. ACN8 was identical to FBP1, which encodes the gluconeogenic enzyme, fructose 1,6-bisphosphatase, while ACN17 and ACN18 were identical to the SDH2 and SDH4 genes, respectively, that encode subunits of the respiratory chain and tricarboxylic acid cycle enzyme, succinate dehydrogenase. Mutants defective in other glyoxylate cycle and gluconeogenic enzymes also display the elevated enzyme phenotype, indicating that the enzyme superinduction is a general property of gluconeogenic dysfunction. Glucose 6-phosphate levels were diminished in the mutants, suggesting that endogenous glucose synthesis can regulate the expression of gluconeogenic enzymes.

Acn9 is a novel protein of gluconeogenesis that is located in the mitochondrial intermembrane space

Previous studies have indicated that the Acn9 protein is involved in gluconeogenesis. Yeast mutants defective in the ACN9 gene display phenotypes identical with mutants defective in metabolic enzymes required for carbon assimilation. These phenotypes include the inability to utilize acetate as a carbon and energy source, elevated levels of enzymes of the glyoxylate cycle, gluconeogenesis and acetyl-CoA mobilization, and a deficiency in de novo synthesis of glucose from ethanol. The ACN9 gene was isolated by functional complementation of the acetate growth defect of an acn9 mutant. The open reading frame corresponds to YDR511w, and encodes a protein of unknown function. Homologs have been identified in human, mouse, and nematode databases. Two mutant alleles were sequenced. The mutations altered amino acid residues that are conserved among members of the new gene family. ACN9 gene expression was slightly repressed by glucose, and the level of the transcript was approximately 100-fold lower than that of glyoxylate or tricarboxylic acid cycle enzymes. A functional epitope-tagged form of Acn9 was expressed to study expression and the subcellular localization of the protein. The tagged protein was localized to the mitochondrial intermembrane space.

Genes of succinyl-CoA ligase from Saccharomyces cerevisiae

Succinyl-CoA ligase (succinyl-CoA synthetase) catalyzes the nucleotide-dependent conversion of succinyl-CoA to succinate. This enzyme functions in the tricarboxylic acid (TCA) cycle and is also involved in ketone-body breakdown in animals. The enzyme is composed of alpha and beta subunits that are required for catalytic activity. Two genes, LSC1 (YOR142W) and LSC2 (YGR244C), with high similarity to succinyl-CoA ligase subunits from other species were isolated from Saccharomyces cerevisiae. The expression of these genes was repressed by growth on glucose and was induced threefold to sixfold during growth on nonfermentable carbon sources. The LSC genes were deleted singly and in combination. Unlike other yeast strains with defects in TCA cycle genes, strains lacking either or both LSC genes were able to grow with acetate as a carbon source. However, growth on glycerol or pyruvate was impaired. An antiserum against both subunits of the Escherichia coli enzyme was capable of recognizing the yeast succinyl-CoA ligase alpha subunit, and this band was absent in delta lsc1 deletion strains. Succinyl-CoA ligase activity was absent in mitochondria isolated from strains deleted for one or both LSC genes, but activity was restored by the presence of the appropriate LSC gene on a plasmid. The yeast succinyl-CoA ligase was shown to utilize ATP but not GTP for succinyl-CoA synthesis.

Evaluation of butorphanol and cyproheptadine for prevention of cisplatin-induced vomiting in dogs

Cisplatin was administered at a dosage of 50 mg/m2 of body surface to 69 dogs with various neoplasms. Dogs were randomly assigned to receive antiemetics according to 1 of the following 5 protocols: group 1, no antiemetic (control, n = 45 treatments); group 2, 0.4 mg of butorphanol/kg of body weight (n = 52 treatments); group 3, 0.2 mg of butorphanol/kg (n = 19 treatments); group 4, 2 mg of cyproheptadine/kg (n = 48 treatments); and group 5, 1 mg of cyproheptadine/kg (n = 10 treatments). Randomization was performed for each dog prior to each treatment. Butorphanol was administered IM immediately after completion of cisplatin infusion. Cyproheptadine was given orally 12 to 14 hours before and again immediately before cisplatin administration. The proportion of dogs that vomited in group 1 was 40 of 45 (89%). Butorphanol at a dosage of 0.4 mg/kg proved highly effective in preventing cisplatin-induced vomiting, reducing the proportion of dogs that vomited (10/52, 19%) compared with the control group.

Evaluation of mitoxantrone for the treatment of lymphoma in dogs

Mitoxantrone was administered to 74 dogs with lymphoma at a dosage of 5.0 mg/m2 of body surface, IV, every 3 weeks. Thirty-four dogs had failed to respond to prior treatment with chemotherapeutic agents, which included doxorubicin (33 dogs). The remaining 40 dogs had not received prior treatment. Complete remission was determined in 19 of 74 dogs (26%), 10 of which had not received prior treatment. The median duration of remission for these 10 dogs was 94 days (range, 49 to 440 days, with 2 dogs still alive at 370 and 440 days, respectively). Nine dogs that had received prior treatment had complete remission that lasted for a median of 126 days (range, 42 to 792 days, with 1 dog still alive at 792 days). The combined remission rate (complete remission plus partial remission) was 41%. Toxicosis was minimal, developing in only 9 dogs and requiring hospitalization of 2 dogs. We concluded that the complete remission rate ascertained when mitoxantrone was the only treatment administered was low, compared with treatments that involved other chemotherapeutic agents; however, the combined remission rate of 41% indicated that mitoxantrone may be beneficial in the treatment of lymphoma in dogs.

Longevity-determining genes in Caenorhabditis elegans: chromosomal mapping of multiple noninteractive loci

We have used chromosome mapping with polymorphic markers to define genetic components governing life span in the nematode Caenorhabditis elegans. A complex recombinant-inbred population was derived from an interstrain cross, yielding > 1000 genotypes, each a composite of homozygous segments from the two parental strains. Genotypes were analyzed for the last-surviving 1-5% of worms in aging cohorts, and for young controls, by multiplex polymerase chain reaction using polymorphic markers to distinguish the parental alleles. We identified five regions of the genome at which one parental allele was significantly enriched in long-lived subpopulations. At four of five loci, the same alleles were selected in aging cohorts maintained under two different conditions, implying that these genes determine life span in differing environments.