Factor XI deficiency and delayed hemorrhages after resection of choroid plexus papilloma: illustrative case

BACKGROUND Factor XI deficiency, also known as hemophilia C, is a rare inherited bleeding disorder that may leave routine coagulation parameters within normal range. Depending on the mutation subtype, prolonged activated partial thromboplastin time may occasionally be found. The disease has an autosomal transmission, with an estimated prevalence in the general population of approximately 1 in 1 million. Heterozygosis accounts for partial deficits, but the tendency to bleed is unrelated to the measured activity of factor XI. Diagnosis usually follows unexpected hemorrhages occurring spontaneously or after trauma or surgical procedures. OBSERVATIONS Few cases have been reported in the neurosurgical literature, all occurring spontaneously or after head trauma. Owing to its subtle features, the true incidence of the disease is probably underestimated. The authors report a case of a patient with previously undiagnosed factor XI deficiency who underwent uncomplicated resection of a fourth-ventricle papilloma and experienced delayed, severe hemorrhagic complications. LESSONS The known association between choroid plexus tumors and intracranial bleeding raised differential diagnosis issues. This report may serve to help to investigate delayed hemorrhages after cranial surgery.

Proteomics Indicates Lactate Dehydrogenase is Prognostic in Acetaminophen-induced Acute Liver Failure Patients and Reveals a Role for LKB1-AMPK Signaling

ABSTRACTBetter biomarkers to predict death early in acute liver failure (ALF) are needed. To that end, we obtained early (study day 1) and later (day 3) serum samples from transplant-free survivors (n=28) and non-survivors (n=30) of acetaminophen (APAP)-induced ALF from the NIH-sponsored Acute Liver Failure Study Group, and from control volunteers (n=10). To identify proteins that increase early in serum during ALF, we selected individuals from this cohort for whom ALT was lower on day 1 than day 3, indicating a time point before the peak of injury (n=10/group). We then performed untargeted proteomics on their day 1 samples. Out of 1,682 quantifiable proteins, 79 were elevated ≥4-fold in ALF patients vs. controls and 23 of those were further elevated ≥4-fold in non-survivors vs. survivors, indicating potential to predict death. Interestingly, the biomarker with best performance was LDH. To confirm the prognostic potential of LDH, we measured activity in all day 1 and 3 samples from all 58 ALF patients. LDH was elevated in the non-survivors vs. survivors on both days. In addition, receiver operating characteristic (ROC) curve analyses revealed that LDH alone performed similarly to the model for end-stage liver disease (MELD), while a combination of MELD and LDH outperformed either alone. Finally, Upstream Analysis of our proteomics data indicated activation of LKB1-AMPK signaling in liver regeneration after APAP overdose and we confirmed that in mice. Overall, we conclude LDH can predict death in APAP-induced ALF and that LKB1-AMPK signaling may be a promising therapeutic target to improve survival.

Anti-inflammatory effect of Helix aspersa extracts in sephadex-induced model of lung inflammation: possible modulation of neutrophils

The focus of our study is to compare the anti-inflammatory effect of extracts prepared from Algerian mollusk called Helix ,on induced lung inflammation in rats: aqueous AE, HE and organic OE extracts. Animals were classified into six groups: control group T was instilled with NaCl (0.9%) in the trachea, negative control group was instilled with in trachea (5mg//Kg), positive control group was instilled with and treated with an anti-inflammatory drug, groups SAE, SHE and SOE were instilled with and treated with aqueous, and organic extracts respectively (4mg//Kg). 24h after instillation, we sacrificed animals, blood samples and fluid lavage (BALF) were collected. Lungs were for investigation. We measured activity (MPO) in BALF. Results showed induces a massive in lungs. HE and OE decreased leukocyte count in BALF and blood. AE increased leukocyte count in blood and decreased it in BALF. The three extracts decreased MPO activity in BALF, reduced number of inflammatory cells in the and protected lung from beads injuries. Both AE and HE reduced edema in lung. We conclude that treatment with Helix had an anti-inflammatory effect on inflammation.

Contrasting Effects of Environmental Concentrations of Sulfonamides on Microbial Heterotrophic Activities in Freshwater Sediments

The sulfonamide antibiotics sulfamethoxazole (SMX) and sulfamethazine (SMZ) are regularly detected in surface sediments of contaminated hydrosystems, with maximum concentrations that can reach tens of μg kg–1 in stream and river sediments. Little is known about the resulting effects on the exposed benthic organisms. Here we investigated the functional response of stream sediment microbial communities exposed for 4 weeks to two levels of environmentally relevant concentrations of SMX and SMZ, tested individually. To this end, we developed a laboratory channel experiment where natural stream sediments were immersed in water contaminated with nominal environmental concentrations of 500 and 5,000 ng L–1 of SMX or SMZ, causing their accumulation in surface sediments. The mean maximum concentrations measured in the sediment (about 2.1 μg SMX kg–1 dw and 4.5 μg SMZ kg–1 dw) were consistent with those reported in contaminated rivers. The resulting chronic exposure had various effects on the functional potential of the sediment microbial communities, according to the substance (SMX or SMZ), the type of treatment (high or low) and the measured activity, with a strong influence of temporal dynamics. Whereas the SMZ treatments resulted in only transient effects on the five microbial activities investigated, we observed a significant stimulation of the β-glucosidase activity over the 28 days in the communities exposed to the high concentration of SMX. Together with the stimulation of aerobic respiration at low SMX concentrations and the reduced concentration observed in the last days, our results suggest a potential biodegradation of sulfonamides by microbial communities from sediments. Given the key functional role of surface sediment microbial communities in streams and rivers, our findings suggest that the frequently reported contamination of sediments by sulfonamides is likely to affect biogeochemical cycles, with possible impact on ecosystem functioning.

Quantitative Effect of Metal Artefact Reduction on CT-based attenuation correction in FDG PET/CT in patients with hip prosthesis

Background Metal artefact reduction (MAR) techniques still are in limited use in positron emission tomography/computed tomography (PET/CT). This study aimed to investigate the effect of Smart MAR on quantitative PET analysis in the vicinity of hip prostheses. Materials and methods Activities were measured on PET/CT images in 6 sources with tenfold activity concentration contrast to background, attached to the head, neck and the major trochanter of a human cadaveric femur, and in the same sources in similar locations after a hip prosthesis (titanium cup, ceramic head, chrome-cobalt stem) had been inserted into the femur. Measurements were compared between PET attenuation corrected using either conventional or MAR CT. In 38 patients harbouring 49 hip prostheses, standardized uptake values (SUV) in 6 periprosthetic regions and the bladder were compared between PET attenuation corrected with either conventional or MAR CT. Results Using conventional CT, measured activity decreased with 2 to 13% when the prosthesis was inserted. Use of MAR CT increased measured activity by up to 11% compared with conventional CT and reduced the relative difference with the reference values to under 5% in all sources. In all regions, to the exception of the prosthesis shaft, SUVmean increased significantly (p < 0.001) by use of MAR CT. Median (interquartile range) percentual increases of SUVmean were 1.4 (0.0–4.2), 4.0 (1.8–7.8), 7.8 (4.1–12.4), 1.5 (0.0–3.2), 1.4 (0.8–2.8) in acetabulum, lateral neck, medial neck, lateral diaphysis and medial diaphysis, respectively. Except for the shaft, the coefficient of variation did not increase significantly. Except for the erratic changes in the prosthesis shaft, decreases in SUVmean were rare and small. Bladder SUVmean increased by 0.9% in patients with unilateral prosthesis and by 4.1% in patients with bilateral prosthesis. Conclusions In a realistic hip prosthesis phantom, Smart MAR restores quantitative accuracy by recovering counts in underestimated sources. In patient studies, Smart MAR increases SUV in all areas surrounding the prosthesis, most markedly in the femoral neck region. This proves that underestimation of activity in the PET image is the most prevalent effect due to metal artefacts in the CT image in patients with hip prostheses. Smart MAR increases SUV in the urinary bladder, indicating effects at a distance from the prosthesis.

Exposure Stability of Quantitative Fluorine-18 Measurements On The Biograph Vision Quadra PET/CT System

Background: Our aim was to determine sets of reconstruction parameters for the Biograph Vision Quadra (Siemens Healthineers) PET/CT system that result in quantitative images compliant with the European Association of Nuclear Medicine Research Ltd. (EARL) criteria. Using the Biograph Vision 600 (Siemens Healthineers) PET/CT technology but extending the axial field of view to 106 cm, gives the Vision Quadra currently an around fivefold higher sensitivity over the Vision 600 with otherwise comparable spatial resolution. Therefore, we also investigated how the number of incident positron decays - i.e. exposure - affects EARL compliance. This will allow estimating a minimal acquisition time or a minimal applied dose in clinical scans while retaining data comparability. Methods: We measured activity recovery curves on a NEMA IEC body phantom filled with an aqueous 18 F solution and a sphere to background ratio of 10 to 1 according to the latest EARL guidelines. Reconstructing 3570 images with varying OSEM PSF iterations, post-reconstruction Gaussian filter full width at half maximum (FWHM), and varying exposure from 0.2 MDecays/ml (= 10 sec frame duration) to 59.2 MDecays/ml (= 1 h frame duration), allowed us to determine sets of parameters to achieve compliance with the current EARL 1 and EARL 2 standards. Recovery coefficients (RCs) were calculated for the metrics RC max , RC mean , and RC peak , and the respective recovery curves were analysed for monotonicity. Results: Using 6 iterations, 5 subsets and 7.8 mm Gauss filtering resulted in best EARL 1 compliance and recovery curve monotonicity in all analysed frames. Most robust EARL2 compliance and monotonicity was achieved with 4 iterations, 5 subsets, and 4.6 mm Gauss FWHM in frames with durations between 10 min and 30 sec. RC peak only impeded EARL2 compliance in the 10 sec frame. Conclusions: While EARL1 compliance proved to be robust over all exposure ranges, EARL2 compliance required exposures between 0.6 MDecays/ml to 11.5 MDecays/ml. The Biograph Vision Quadra’s high sensitivity makes frames as short as 10 sec feasible for comparable quantitative images. Lowering EARL2 RC max limits closer to unity would possibly even permit 10 sec EARL2 compliant frames.

Bone Scintigraphy of Vertebral Fractures With a Whole-Body CZT Camera in a PET-Like Utilization

Objective: An image display with a standardized uptake value (SUV) scale is recommended for analyzing PET exams, thus requiring the reconstruction of accurate images for both SUV measurement and visual analysis. This study aimed to determine whether such images may also be obtained with a high-speed CZT-SPECT/CT system, with a further application for the longitudinal monitoring of vertebral fractures.Materials and Methods: SPECT image reconstruction was optimized with an IEC phantom according to both image quality parameters and accuracy of measured activity. The optimized reconstruction process was applied to ≤15 min 99mTc-HDP SPECT spine recordings previously acquired from 25 patients (74 ± 12 years old) at both early (1.3 ± 1.1 months) and late (5.2 ± 2.3 months) stages after an acute vertebral fracture.Results: A SPECT reconstruction with 32 equivalent iterations was selected based on the association of high detectability for spheres down to 0.6 ml in volume, with accurate measured activity, although the latter was affected by partial volume effect for spheres ≤5.6 ml. Coherent measurements were obtained on these high-quality SPECT images for the SUVmax from the intact vertebrae of patients, which were stable between basal SPECT/CT and follow-up SPECT/CT (for T1 vertebrae: 5.7 ± 1.1 vs. 5.8 ± 1.1, p = 0.76), and from initially fractured vertebrae, which were dramatically higher on the basal compared with the follow-up SPECT (21.0 ± 8.5 vs. 11.2 ± 4.2, p &lt; 0.001), whereas inverse changes in SUVmax were observed for newly compacted fractures identified on follow-up SPECT (74.4 ± 2.0 vs. 21.8 ± 10.3, p = 0.002). Finally, an image display with an SUV scale was shown to be advantageous for highlighting areas with &gt;7.5 SUV, a level reached by 98% of vertebral fractures of &lt;7 months and 4% of reference intact vertebrae.Conclusion: Bone scintigraphy of vertebral fractures may be obtained with this CZT-SPECT/CT system with fast 3D acquisitions and high-quality images displayed with a reliable SUV scale, approaching what is achieved and recommended for PET imaging.

fNIRS Monitoring of Infant Prefrontal Cortex During Crawling and an Executive Functioning Task

Functional near-infrared spectroscopy (fNIRS)is a brain-imaging technology used to reveal brain activity by measuring blood oxygenation. Using fNIRS we measured activity in the left prefrontal lobe of 8–14 month-old infants as they crawled or were pushed in a stroller and as they were given a passive attention task or an active executive function (EF) task. For each task, we measured peak total hemoglobin concentration and peak Oxy relative to baseline. Results revealed differences in peak Oxy levels for crawling vs. strolling and between the EF and passive cognitive tasks, with total hemoglobin greater for the EF task than the passive attention task. These results support the theoretical view that both active locomotion and EF engage the prefrontal cortex (PFC) during early development.