Intracranial pressure waveform characteristics in idiopathic normal pressure hydrocephalus and late-onset idiopathic aqueductal stenosis.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) and late-onset idiopathic aqueductal stenosis (LIAS) are two forms of chronic adult hydrocephalus of different aetiology. We analysed overnight intracranial pressure (ICP) monitoring to elucidate ICP waveform changes characteristic for iNPH and LIAS to better understand pathophysiological processes of both diseases. METHODS: 98 patients with iNPH and 14 patients with LIAS from two neurosurgical centres were included. All patients underwent diagnostic overnight computerised ICP monitoring with calculation of mean ICP, ICP heartbeat related pulse wave amplitude calculated in the frequency domain (AMP) and the time domain (MWA), index of cerebrospinal compensatory reserve (RAP) and power of slow vasogenic waves (SLOW). RESULTS: ICP was higher in LIAS than iNPH patients (9.3 ± 3.0 mmHg versus 5.4 ± 4.2 mmHg, p = 0.001). AMP and MWA were higher in iNPH versus LIAS (2.36 ± 0.91 mmHg versus 1.81 ± 0.59 mmHg for AMP, p = 0.012; 6.0 ± 2.0 mmHg versus 4.9 ± 1.2 mmHg for MWA, p = 0.049). RAP and SLOW indicated impaired reserve capacity and compliance in both diseases, but did not differ between groups. INPH patients were older than LIAS patients (77 ± 6 years versus 54 ± 14 years, p < 0.001). CONCLUSIONS: ICP is higher in LIAS than in iNPH patients, likely due to the chronically obstructed CSF flow through the aqueduct, but still in a range considered normal. Interestingly, AMP/MWA was higher in iNPH patients, suggesting a possible role of high ICP pulse pressure amplitudes in iNPH pathophysiology. Cerebrospinal reserve capacity and intracranial compliance is impaired in both groups and the pressure-volume relationship might be shifted towards lower ICP values in iNPH. The physiological influence of age on ICP and AMP/MWA requires further research.

Medical Student Attitudes toward USMLE Step 1 and Health Systems Science - A Multi-Institutional Survey.

Phenomenon: Because of its importance in residency selection, the United States Medical Licensing Examination Step 1 occupies a critical position in medical education, stimulating national debate about appropriate score use, equitable selection criteria, and the goals of undergraduate medical education. Yet, student perspectives on these issues and their implications for engagement with health systems science-related curricular content are relatively underexplored. Approach: We conducted an online survey of medical students at 19 American allopathic medical schools from March-July, 2019. Survey items were designed to elicit student opinions on the Step 1 examination and the impact of the examination on their engagement with new, non-test curricular content related to health systems science. Findings: A total of 2856 students participated in the survey, representing 23.5% of those invited. While 87% of students agreed that doing well on the Step 1 exam was their top priority, 56% disagreed that studying for Step 1 had a positive impact on engagement in the medical school curriculum. Eighty-two percent of students disagreed that Step 1 scores should be the top item residency programs use to offer interviews. When asked whether Step 1 results should be reported pass/fail with no numeric score, 55% of students agreed, while 33% disagreed. The majority of medical students agreed that health systems science topics were important but disagreed that studying for Step 1 helped learn this content. Students reported being more motivated to study a topic if it was on the exam, part of a course grade, prioritized by residency program directors, or if it would make them a better physician in the future. Insights: These results confirm the primacy of the United States Medical Licensing Examination Step 1 exam in preclinical medical education and demonstrate the need to balance the objectives of medical licensure and residency selection with the goals of the broader medical profession. The survey responses suggest several potential solutions to increase student engagement in health systems science curricula which may be especially important after Step 1 examination results are reported as pass/fail.

Real-Time Continuous Glucose Monitoring in Gestational Diabetes: A Randomized Controlled Trial.

OBJECTIVE: To evaluate whether real-time continuous glucose monitoring improves glycemic control over intermittent self-monitoring of blood glucose in gestational diabetes. STUDY DESIGN: We performed a single-institution randomized controlled trial. Patients with gestational diabetes were randomized to use either real-time or blinded continuous glucose monitoring. The primary outcome was mean sensor glucose level during the fourth week of continuous glucose monitoring use. Secondary outcomes included glycemic control and a composite of obstetric and neonatal outcomes. RESULTS: Of the 40 enrolled patients, 12 (60%) patients in the blinded continuous glucose monitoring group and 11 (55%) in the real-time continuous glucose monitoring group completed 4 weeks of monitoring and were included in the final analysis. There was no significant difference in mean sensor glucose level between the blinded continuous glucose monitoring group (98.9 ± 8.9 mg/dL) and the real-time continuous glucose monitoring group (107.5 ± 11.4 mg/dL). There were also no significant differences in the time spent in glycemic target, maternal, or neonatal outcomes. CONCLUSION: Our study shows that the use of continuous glucose monitoring with real-time feedback did not significantly decrease mean glucose values compared with intermittent self-monitoring of blood glucose after 4 weeks of continuous glucose monitoring use.

Genetic characterization of clinical isolates of Clostridium difficile using an optimized RAPD protocol and PCR ribotyping reveals strain diversity between two tertiary referral Trusts in the West Midlands, UK.

Epidemiological investigations of Clostridium difficile often focus on differences between separate geographical areas. In this investigation, two populations of C. difficile recovered from separate tertiary referral Trusts within the West Midlands, UK, were characterized using both PCR ribotyping and an optimized RAPD (random amplification of polymorphic DNA) protocol. The PCR ribotyping and RAPD methodologies identified differences between the two C. difficile populations, in both the prevalence and the diversity of types identified. The use of PCR ribotyping in conjunction with RAPD further categorized different types within defined PCR ribotypes, identifying different types within the same PCR ribotype and therefore providing a greater discriminatory power than either of the methods when used alone. The differences observed in this study between the two Trusts in the distribution of both RAPD 'type' and PCR ribotype demonstrate the diversity that is present amongst isolates of C. difficile within a relatively small geographical area and warrants a need for further investigation into the local epidemiology of C. difficile.

Effect of morphine on the growth rate of Calliphora stygia (Fabricius) (Diptera: Calliphoridae) and possible implications for forensic entomology.

Insect specimens collected from decomposing bodies enable forensic entomologists to estimate the minimum post-mortem interval (PMI). Drugs and toxins within a corpse may affect the development rate of insects that feed on them and it is vital to quantify these effects to accurately calculate minimum PMI. This study investigated the effects of morphine on growth rates of the native Australian blowfly, Calliphora stygia (Fabricius) (Diptera: Calliphoridae). Several morphine concentrations were incorporated into pet mince to simulate post-mortem concentrations in morphine, codeine and/or heroin-dosed corpses. There were four treatments for feeding larvae; T 1: control (no morphine); T 2: 2 microg/g morphine; T 3: 10 microg/g morphine; and T 4: 20 microg/g morphine. Ten replicates of 50 larvae were grown at 22 degrees C for each treatment and their development was compared at four comparison intervals; CI 1: 4-day-old larvae; CI 2: 7-day-old larvae; CI 3: pupae; and CI 4: adults. Length and width were measured for larvae and pupae, and costae and tibiae were measured for adults. Additionally, day of pupariation, day of adult eclosion, and survivorship were calculated for each replicate. The continued presence of morphine in meat was qualitatively verified using high-performance liquid chromatography with acidic potassium permanganate chemiluminescence detection. Growth rates of C. stygia fed on morphine-spiked mince did not differ significantly from those fed on control mince for any comparison interval or parameter measured. This suggests that C. stygia is a reliable model to use to accurately age a corpse containing morphine at any of the concentrations investigated.