Magnetic resonance imaging reveals specific anatomical changes in the brain of Agat- and Gamt-mice attributed to creatine depletion and guanidinoacetate alteration.

Arginine:glycine amidinotransferase- and guanidinoacetate methyltransferase deficiency are severe neurodevelopmental disorders. It is not known whether mouse models of disease express a neuroanatomical phenotype. High-resolution magnetic resonance imaging (MRI) with advanced image analysis was performed in perfused, fixed mouse brains encapsulated with the skull from male, 10-12 week old Agat -exc and B6J.Cg-Gamt tm1Isb mice (n = 48; n = 8 per genotype, strain). T2-weighted MRI scans were nonlinearly aligned to a 3D atlas of the mouse brain with 62 structures identified. Local differences in brain shape related to genotype were assessed by analysis of deformation fields. Creatine (Cr) and guanidinoacetate (GAA) were measured with high-performance liquid chromatography (HPLC) in brain homogenates (n = 24; n = 4 per genotype, strain) after whole-body perfusion. Cr was decreased in the brain of Agat- and Gamt mutant mice. GAA was decreased in Agat-/- and increased in Gamt-/- . Body weight and brain volume were lower in Agat-/- than in Gamt-/- . The analysis of entire brain structures revealed corpus callosum, internal capsule, fimbria and hypothalamus being different between the genotypes in both strains. Eighteen and fourteen significant peaks (local areas of difference in relative size) were found in Agat- and Gamt mutants, respectively. Comparing Agat-/- with Gamt-/- , we found changes in three brain regions, lateral septum, amygdala, and medulla. Intra-strain differences in four brain structures can be associated with Cr deficiency, while the inter-strain differences in three brain structures of the mutant mice may relate to GAA. Correlating these neuroanatomical findings with gene expression data implies the role of Cr metabolism in the developing brain and the importance of early intervention in patients with Cr deficiency syndromes.

Storage and handling of human faecal samples affect the gut microbiome composition: A feasibility study.

Human gut microbiome analysis through faecal sampling typically involves five stages: sample collection, storage, DNA extraction, next generation sequencing and bioinformatics analysis. Of these, the first three are considered irreversible. This feasibility study describes an assessment of methodologies used for faecal DNA extraction and sample handling, using the parameters DNA yield, purity and resultant microbial profile. Six DNA extraction techniques, including commercially available kits and manual protocols were compared on human faecal samples (n = 3). Different extraction techniques produced significant variance in DNA yield (range 2.7-164 ng/mg faeces) and microbial diversity profiles, with considerable variation in phyla dominance (Firmicutes (P < 0.001), Bacteroidetes (P = 0.003), Actinobacteria (P = 0.003), One-way ANOVA). The most effective method, with the highest DNA yield, was a simple and inexpensive extraction technique named MetaHIT. Using this method, DNA was extracted from separate faecal samples (n = 3) and had been aliquoted to seven storage conditions including three stabilizing buffers and three temperature conditions, for a period of 120-h, with storage at -80 °C as a control treatment. DNA yield and purity was not statistically different between the control and remaining treatments. 16S rDNA-based diversity profile was largely comparable across the treatments with only minor differences in genera between samples stored at room temperature in air and - 80 °C control. Overall these results suggest that the choice of DNA extraction method has a greater influence on the resultant microbial diversity profile than the short-term storage method.

Design of experiments to optimize an in vitro cast to predict human nasal drug deposition.

BACKGROUND: Previous studies showed nasal spray in vitro tests cannot predict in vivo deposition, pharmacokinetics, or pharmacodynamics. This challenge makes it difficult to assess deposition achieved with new technologies delivering to the therapeutically beneficial posterior nasal cavity. In this study, we determined best parameters for using a regionally divided nasal cast to predict deposition. Our study used a model suspension and a design of experiments to produce repeatable deposition results that mimic nasal deposition patterns of nasal suspensions from the literature. METHODS: The seven-section (the nozzle locator, nasal vestibule, front turbinate, rear turbinate, olfactory region, nasopharynx, and throat filter) nylon nasal cast was based on computed tomography images of healthy humans. It was coated with a glycerol/Brij-35 solution to mimic mucus. After assembling and orienting, airflow was applied and nasal spray containing a model suspension was sprayed. After disassembling the cast, drug depositing in each section was assayed by HPLC. The success criteria for optimal settings were based on nine in vivo studies in the literature. The design of experiments included exploratory and half factorial screening experiments to identify variables affecting deposition (angles, airflow, and airflow time), optimization experiments, and then repeatability and reproducibility experiments. RESULTS: We found tilt angle and airflow time after actuation affected deposition the most. The optimized settings were flow rate of 16 L/min, postactuation flow time of 12 sec, a tilt angle of 23°, nozzle angles of 0°, and actuation speed of 5 cm/sec. Neither cast nor operator caused significant variation of results. CONCLUSION: We determined cast parameters to produce results resembling suspension nasal sprays in the literature. The results were repeatable and unaffected by operator or cast. These nasal spray parameters could be used to assess deposition from new devices or formulations. For human deposition studies using radiolabeled formulations, this cast could show that radiolabel deposition represents drug deposition. Our methods could also be used to optimize settings for other casts.

Developing and pilot testing practical measures of preanalytic surgical specimen identification defects.

Accurate patient identification is a National Patient Safety Goal. Misidentification of surgical specimens is associated with increased morbidity, mortality, and costs of care. The authors developed 12 practical, process-based, standardized measures of surgical specimen identification defects during the preanalytic phase of pathology testing (from the operating room to the surgical pathology laboratory) that could be used to quantify the occurrence of these defects. The measures (6 container and 6 requisition identification defects) were developed by a panel of physicians, pathologists, nurses, and quality experts. A total of 69 hospitals prospectively collected data over 3 months. Overall, there were identification defects in 2.9% of cases (1780/60 501; 95% confidence interval [CI] = 2.0%-4.4%), 1.2% of containers (1018/81 656; 95% CI = 0.8%-2.0%), and 2.3% of requisitions (1417/61 245; 95% CI = 1.2%-4.6%). Future research is needed to evaluate if hospitals are able to use these measures to assess interventions meant to reduce the frequency of specimen identification defects and improve patient safety.

Can a novel MRI staging system for low rectal cancer aid surgical planning?

BACKGROUND: Low rectal cancers are associated with worse outcomes in comparison with mid and upper rectal tumors. OBJECTIVE: This study aimed to assess the predictive accuracy of MRI in identifying the correct surgical approach based on the mesorectal and extralevator planes. DESIGN: This study involved the retrospective analysis of MRI and histopathology data of 33 patients with low rectal cancer, with the use of an anatomically based staging system. Three radiologists reported on the available surgical planes of excision based on the predicted relationship of tumor to key anatomical features. MRI-predicted planes of excision were then compared with the histopathological planes actually required, with the use of the same staging criteria. SETTINGS: The study was conducted at 4 English district general hospitals. PATIENTS: Unselected patients with low rectal cancer, all of whom were participants in a multicenter study, were eligible for this study. MAIN OUTCOME MEASURES: : The main outcome measured was the accuracy of operative plane prediction on MRI. RESULTS: : On pathological analysis, the mesorectal plane would have been sufficient to achieve a clear margin in 28 of 33 (84.9%) of cases. The extralevator plane was required in 5 of 33 (15.1%). Planes were correctly predicted by MRI in 29 of 33 cases by radiologist 1 and 24 of 33 cases by radiologists 2 and 3 with an accuracy of 87.9% and 72.7%. Overstaging (extralevator plane predicted when a mesorectal plane would have sufficed) occurred in 3 of 33 and 7 of 33 cases. Understaging (mesorectal plane predicted when an extralevator plane was required) occurred in 1 of 33 and 2 of 33 cases. The positive and negative predictive values of MRI in determining the histopathological plane of excision required were 57% and 96% for radiologist 1 and 30% and 91% for radiologists 2 and 3. LIMITATIONS: This study was limited by its retrospective nature and its relatively small patient numbers. No account was taken of postoperative function when recommending the surgical plane. CONCLUSIONS: This supports an anatomically based MRI staging system for low rectal cancer to predict the planes of surgical excision. This may help to reduce margin positivity and to improve outcome in patients with low rectal cancer.

Michigan Health & Hospital Association Keystone Obstetrics: a statewide collaborative for perinatal patient safety in Michigan.

BACKGROUND: Preventable harm to mothers and infants during labor and birth is a significant patient safety and professional liability issue. A Michigan Health & Hospital Association Keystone Center for Patient Safety & Quality Obstetric Collaborative Project involved perinatal teams from 15 Michigan hospitals during an 11-month period in 2009. The purpose of the project was to promote safe care practices during labor and birth using the Comprehensive Unit-based Safety Program (CUSP). Consistent with the CUSP model, this project's components included assessing and promoting a culture of safety; interdisciplinary team building; case review; learning from defects through multiple methods of education; team and individual coaching and peer encouragement; administrative support for the establishment of a fundamental safety infrastructure; and ongoing evaluation of care processes and outcomes. METHODS: Study measures included 32 components of a perinatal patient infrastructure, 6 care processes during labor and birth, and 4 neonatal outcomes. RESULTS: Significant improvements were found in the safety culture (Safety Attitudes Questionnaire), the perinatal patient safety infrastructure components, and all care processes. CONCLUSIONS: Although the project was successful, getting buy-in from all members of the clinical team in each hospital for all of the measures was challenging at times. There was initial resistance to some of the measures and their various expected aspects of care. For example, some of the clinicians were initially reluctant to adopt the recommended standardized oxytocin protocol. Peer encouragement and unit-based feedback on progress in minimizing early elective births proved useful in many hospitals. A CUSP in obstetrics can be beneficial in improving the care of mothers and infants during labor and birth.

Characteristics of intensive care units in Michigan: not an open and closed case.

OBJECTIVE: Delivery of critical care by intensivists has been recommended by several groups. Our objective was to understand the delivery of critical care physician services in Michigan and the role of intensivists and nonintensivist providers in providing care. DESIGN: Descriptive questionnaire. PARTICIPANTS AND SETTING: Intensive care unit (ICU) directors and nurse managers at 96 sites, representing 115 ICUs from 72 hospitals in Michigan. MEASUREMENTS AND RESULTS: The primary outcome measure was the percentage of sites utilizing a closed vs. an open model of ICU care. Secondary outcome measures included the percentage of ICUs utilizing a high-intensity service model, hospital size, ICU size, type of clinician providing care, and clinical activities performed. Twenty-four (25%) sites used a closed model of intensive care, while 72 (75%) had an open model of care. Hospitals with closed ICUs were larger and had larger ICUs than sites with open ICUs (P < 0.05). Hospitalists serving as attending physicians were strongly associated with an open ICU (odds ratio [OR] = 12.2; 95% confidence interval [CI] = 2.5-60.2), as was the absence of intensivists in the group (OR = 12.2; 95%CI = 1.4-105.8), while ICU and hospital size were not associated. At 18 sites (20%) all attendings were board certified in Critical Care. Sixty sites had less than 50% board-certified attending physicians. CONCLUSIONS: The closed intensivist-led model of intensive care delivery is not in widespread use in Michigan. In the absence of intensivists, alternate models of care, including the hospitalist model, are frequently used.