A deep learning method to identify and localize large-vessel occlusions from cerebral digital subtraction angiography

BACKGROUND AND PURPOSE

An essential step during endovascular thrombectomy is identifying the occluded arterial vessel on a cerebral digital subtraction angiogram (DSA). We developed an algorithm that can detect and localize the position of occlusions in cerebral DSA.

METHODS

We retrospectively collected cerebral DSAs from a single institution between 2018 and 2020 from 188 patients, 86 of whom suffered occlusions of the M1 and proximal M2 segments. We trained an ensemble of deep-learning models on fewer than 60 large-vessel occlusion (LVO)-positive patients. We evaluated the model on an independent test set and evaluated the truth of its predicted localizations using Intersection over Union and expert review.

RESULTS

On an independent test set of 166 cerebral DSA frames with an LVO prevalence of 0.19, the model achieved a specificity of 0.95 (95% confidence interval [CI]: 0.90, 0.99), a precision of 0.7450 (95% CI: 0.64, 0.88), and a sensitivity of 0.76 (95% CI: 0.66, 0.91). The model correctly localized the LVO in at least one frame in 13 of the 14 LVO-positive patients in the test set. The model achieved a precision of 0.67 (95% CI: 0.52, 0.79), recall of 0.69 (95% CI: 0.46, 0.81), and a mean average precision of 0.75 (95% CI: 0.56, 0.91).

CONCLUSION

This work demonstrates that a deep learning strategy using a limited dataset can generate effective representations used to identify LVOs. Generating an expanded and more complete dataset of LVOs with obstructed LVOs is likely the best way to improve the model's ability to localize LVOs.

Effect of baseline urinary glucose levels on the relationship between sodium-glucose cotransporter 2 inhibitors and serum uric acid in Japanese patients with type 2 diabetes mellitus

In patients with type 2 diabetes mellitus (T2DM), controlling serum uric acid (SUA) and blood glucose levels is important. Moreover, sodium-glucose cotransporter 2 (SGLT2) inhibitors decrease SUA levels by accelerating urinary uric acid excretion. We investigated the effect of baseline urinary glucose levels on the relationship between SGLT2 inhibitors and SUA levels. We conducted a retrospective observational study using the electronic medical records of patients with T2DM of Kindai University Nara Hospital (April 2013 to March 2022). We divided the patients into two groups according to their baseline urinary glucose levels: the N-UG group, which included patients with negative urinary glucose strip test results (-), and the P-UG group, which included patients with positive urinary glucose strip test results (± or more). The changes in SUA levels before and after SGLT2 inhibitor administration were investigated. For comparison, the changes in SUA levels before and after the prescription of antidiabetic agents, excluding SGLT2 inhibitors, were also investigated. Our results revealed that SGLT2 inhibitors significantly decreased the SUA levels in patients in the N-UG group but tended to decrease its levels in those in the P-UG group. Regardless of the urinary glucose status at baseline, the administration of SGLT2 inhibitors may be useful for patients with T2DM to prevent the complications of hyperuricemia.

Use of angled-tip aspiration catheters is associated with a lower cost of thrombectomy in patients with acute ischemic stroke secondary to large and medium vessel occlusions

BACKGROUND

Recently, the angled-tip Zoom™ aspiration catheters were introduced. The tip is designed to improve suction force for clot retrieval. We evaluated the possibility of reducing procedure costs when using angled-tip catheters and compared the safety and angiographic effectiveness of angled-tip versus straight-tip catheters.

METHODS

We conducted a retrospective single-center cohort study involving patients with acute ischemic stroke due to large and medium vessel occlusions. The patients were divided into two groups: the post-Zoom group, in which angled-tip aspiration catheters were used and the pre-Zoom group, in which traditional straight-tip catheters were employed.

RESULTS

A total of 163 patients were included; 95 (58.3%) in the pre-Zoom group and 68 (41.7%) in the post-Zoom group. The groups were well-matched at entry. The post-Zoom group demonstrated a significant decrease in mean procedure cost ($9728 vs. $12,127; p = 0.002), shorter time to achieve modified thrombolysis in cerebral infarction ≥2b reperfusion (38.30 min vs. 53.26 min; p = 0.018), and shorter puncture to procedure completion time (46.42 min vs. 62.38 min; p = 0.022). Additionally, the mean procedural cost when using the ADAPT technique supported by the Zoom catheters was significantly lower than the Solumbra technique ($5754 ± $2806 vs. $13,498 ± $3244, p < 0.001). There were no differences in the rate of hemorrhage between the pre-Zoom group (17.9%) and the post-Zoom group (20.6%), p = 0.690.

CONCLUSION

The study demonstrated significant benefits, including cost reduction and shorter time to achieve reperfusion in patients treated with Zoom aspiration catheters. These findings support the use of angled-tip catheters in acute ischemic stroke management.

Abstract TP172: Predicting Poor Response To Anti-coagulation Therapy In Cerebral Venous Thrombosis Using A Simple Clinical-radiological Score

Few studies target to identify predictors of poor response to anticoagulation therapy in Cerebral Venous Thrombosis (CVT). We aimed to determine the predictors of poor clinical response to therapeutic anticoagulation in acute CVT.

Methods: We performed a retrospective analysis of patients therapeutically anticoagulated for acute CVT. We defined poor clinical outcomes as death, need for mechanical thrombectomy during the hospitalization, or a modified Rankin Scale (mRS) >3 at clinical follow-up. Multivariate analyses identified factors associated with poor outcomes in anticoagulated patients for acute CVT, and we used the identified factors to create the PRACT-CVT (Poor Response to Anticoagulation Therapy in CVT) score.

Results: We included 109 patients anticoagulated with acute CVT. Twenty-one (19%) patients had poor clinical outcomes. Age >65 or <10 years (OR: 3.16, 95% CI: 1.06-9.44), a GCS ≤12 upon presentation (OR: 19.2, 95% CI: 4.05-91.4), focal motor deficits at admission (OR: 5.03, 95% CI: 1.64-15.44), clinical deterioration following admission (OR: 28.18, CI: 4.81-164.86), seizures following admission (OR: 5.59, 95% CI: 1.27-24.51), evidence of brain bleeding/ischemia on admission (OR: 4.67, 95% CI: 1.42-15.34), involvement of the superior sagittal sinus (OR: 3.88, CI: 1.33-11.32), or involvement of both transverse sinuses (OR: 3.87, 95% CI: 1.01-14.90) predicted poor clinical outcome despite therapeutic anticoagulation. A PRACT-CVT score (0-22 points) of ≥7 points provided a sensitivity of 71% and a specificity of 95% for predicting poor clinical outcomes with anticoagulation alone.

Conclusion: Patients with acute CVT, presenting with a GCS ≤12, with focal motor deficits, showing clinical deterioration after admission, having seizures during hospitalization, with brain bleeding/ischemia on initial imaging, involvement of the superior sagital sinus, or involvement of both transverse sinuses had poor response to anticoagulation.

Predicting poor response to anti-coagulation therapy in cerebral venous thrombosis using a simple clinical-radiological score

BACKGROUND

Multiple studies have attempted to determine predictors of poor clinical outcomes in cerebral venous thrombosis (CVT). Fewer studies target to identify predictors of poor response to anticoagulation therapy in CVT.

OBJECTIVE

We aimed to determine the predictors of poor clinical response to therapeutic anticoagulation in patients with acute CVT.

METHODS

We performed a retrospective analysis of patients therapeutically anticoagulated for acute CVT. We defined poor clinical outcomes as death, need for mechanical thrombectomy during the hospitalization, or a modified Rankin Scale (mRS) > 3 at clinical follow-up. Bivariate and multivariate analyses identified factors associated with poor outcomes in anticoagulated patients for acute CVT, and we used the identified factors to create the PRACT-CVT (Poor Response to Anticoagulation Therapy in CVT) score.

RESULTS

We included 109 patients anticoagulated with acute CVT. The mean patient age was 37 years old (SD 19); nine patients were > 65 years, ten patients were < 10 years, and 64 (59%) were female. Twenty-one (19%) patients had poor clinical outcomes. Age > 65 or < 10 years (OR: 3.16, 95% CI: 1.06-9.44), a GCS ≤ 12 upon presentation (OR: 19.2, 95% CI: 4.05-91.4), focal motor deficits at admission (OR: 5.03, 95% CI: 1.64-15.44), clinical deterioration following admission (OR: 28.18, CI: 4.81-164.86), seizures following admission (OR: 5.59, 95% CI: 1.27-24.51), evidence of brain bleeding/ischemia on admission (OR: 4.67, 95% CI: 1.42-15.34), involvement of the superior sagittal sinus (OR: 3.88, CI: 1.33-11.32), or involvement of both transverse sinuses (OR: 3.87, 95% CI: 1.01-14.90) predicted poor clinical outcome despite therapeutic anticoagulation. A PRACT-CVT score (0-22 points) of ≥ 7 points provided a sensitivity of 71% and a specificity of 95% for predicting poor clinical outcomes with anticoagulation alone.

CONCLUSION

Patients with acute CVT aged > 65 or < 10 years old, presenting with a GCS ≤ 12, with focal motor deficits, showing clinical deterioration after admission, having clinical seizures during hospitalization, with brain bleeding/ischemia on initial neuroimaging, involvement of the superior sagittal sinus, or involvement of both transverse sinuses had poor response to anticoagulation. Clinicians may employ the PRACT-CVT score to predict poor response to anticoagulation for acute CVT.

Time-dependent changes in serum magnesium levels in patients receiving cetuximab with low baseline serum sodium levels

Cetuximab causes electrolyte abnormalities, such as hypomagnesemia, hypokalemia, and hypocalcemia. However, little is known about the relationships between the onset of hypomagnesemia, patient background before administration, and time-dependent changes in serum magnesium levels. Therefore, we examined the patient backgrounds that influenced the onset of hypomagnesemia and the time-dependent changes in serum magnesium levels in patients receiving cetuximab. A retrospective study was performed to investigate patients with advanced or recurrent colorectal cancer or head and neck cancer, treated with a cetuximab regimen from 2012 to 2020 at Kindai University Nara Hospital. In total, 52 patients who met the inclusion criteria were enrolled in this study. The serum magnesium level was significantly lower in the hyponatremia before the administration group than in the non-hyponatremia group (p < 0.001). Univariate logistic regression analysis revealed that the baseline serum sodium levels (odds ratio [OR]: 0.741, 95% confidence interval [CI]: 0.588-0.934) and the combination of magnesium oxide tablet (OR: 0.997, 95% CI: 0.995-0.999) were one of the independent factors for hypomagnesemia. These results indicated that hyponatremia before administration may be an indicator of serum magnesium levels after administration of cetuximab. Cetuximab-induced hypomagnesemia may be predicted using baseline serum sodium levels, and hypomagnesemia may be prevented by administration of magnesium oxide tablets. Our findings provided new evidence for the management of serum magnesium levels in patients receiving cetuximab.

Lead-free MCP to improve coincidence time resolution and reduce MCP direct interactions

Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.

Useful laboratory markers for the diagnosis of bone marrow involvement by malignant lymphoma

INTRODUCTION

This study aimed to investigate the effect of bone marrow involvement by malignant lymphoma (BMI) on laboratory data and to determine the useful laboratory markers for diagnosing BMI.

METHODS

We compared laboratory data between patients with and without BMI. We performed multivariate logistic regression and receiver operating characteristic (ROC) analyses to evaluate the diagnostic values of independent predictors.

RESULTS

In the BMI group, platelets in peripheral blood (PLT) and megakaryocyte count in bone marrow (MgK) were significantly lower than those in the non-BMI group (PLT, P < .0001; MgK, P = .0384). The rate of peripheral blood involvement by malignant lymphoma (PBI), red blood cell distribution width (RDW), D-dimer (DD), soluble interleukin-2 receptor (sIL2R), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) was significantly higher in the BMI group than in the non-BMI group (PBI, P < .0001; RDW, P = .0190; DD, P = .0006; sIL2R, P < .0001; AST, P = .0256; LDH, P = .0002). In multivariate analysis, PBI, PLT, sIL2R, and MgK levels were independent predictors of BMI.

CONCLUSION

PBI, PLT, sIL2R, and MgK may be the useful laboratory markers for BMI diagnosis.

Wash or wipe? A comparative study of skin physiological changes between water washing and wiping after skin cleaning

BACKGROUND/PURPOSE

Presently, skin-cleaning agents that claim to be removed by water or wiping alone are commercially available and have been used for the purpose of bed baths. However, there is a lack of knowledge on how water washing and wiping differently affect skin physiological functions or ceramide content. The aim of this study was to compare the effects of water washing and wiping on skin physiological functions and ceramide content.

METHODS

Three kinds of the cleaning agents with different removal techniques (ie, water washing and wiping) were used in this study. Skin physiological functions (ie, transepidermal water loss, skin hydration, and skin pH) and skin ceramide content were measured before and after seven consecutive days of the application of each cleaning agent.

RESULTS

No significant differences in skin physiological functions or ceramide content were observed between water washing and wiping.

CONCLUSION

Cleaning agents that claim to be removed by water washing or wiping do not affect skin physiological functions or ceramide content by either removal method.

A phylogenetic foundation for comparative mammalian genomics

A major effort is being undertaken to sequence an array of mammalian genomes. Coincidentally, the evolutionary relationships of the 18 presently recognized orders of placental mammals are only just being resolved. In this work we construct and analyse the largest alignments of amino acid sequence data to date. Our findings allow us to set up a series of superordinal groups (clades) to act as prior hypotheses for further testing. Important findings include strong evidence for a clade of Euarchonta+Glires (=Supraprimates) comprised of primates, flying lemurs, tree shrews, lagomorphs and rodents. In addition, there is good evidence for a clade of all placental mammals except Xenarthra and Afrotheria (=Boreotheria) and for the previously recognised clades Laurasiatheria, Scrotifera, Fereuungulata, Ferae, Afrotheria, Euarchonta, Glires, and Eulipotyphla. Accordingly, a revised classification of the placental mammals is put forward. Using this and molecular divergence-time methods, the ages of the superordinal splits are estimated. While results are strongly consistent with the earliest superordinal divergences all being >65 mybp (Cretaceous period), they suffer from greater uncertainty than presently appreciated. The early primate split of tarsiers from the anthropoid lineage at ~55 mybp is seen to be an especially informative fossil calibration point. A statistical framework for testing clades using SINE data is presented and reveals significant support for the tarsier/anthropoid clade, as well as the clades Cetruminantia and Whippomorpha. Results also underline our thesis that while sequence analysis can help set up hypothesised clades, SINEs obtainable from sequencing 1-2 MB regions of placental genomes are essential to testing them. In contrast, derivations suggest that empirical Bayesian methods for sequence data may not be robust estimators of clades. Our findings, including the study of genes such as TP53, make a good case for the tree shrew as a closer relative of primates than rodents, while also showing a slower rate of evolution in key cell cycle genes. Tree shrews are consequently high value experimental animals and a strong candidate for a genome sequencing initiative.

Appropriate likelihood ratio tests and marginal distributions for evolutionary tree models with constraints on parameters

We show how to make appropriate likelihood ratio tests for evolutionary tree models when parameters such as edge (internodes or branches) lengths have nonnegativity constraints. In such cases, under the null model of an edge length being zero, the marginal distribution of this parameter is proven to be a "half-normal", that is, 50% zero values and 50% the positive half of a normal distribution. Other constrained parameters, such as the proportion of invariant sites, give similar results. To make likelihood ratio tests between nested models, e.g., H(0): homogeneous site rates, and H(1): site rates follow a gamma distribution with variance 1/k, then asymptotically as sequence length increases, the distribution under H(0) becomes a mixture of chi distributions, in this case 50% chi(0), and 50% chi(1) (where the subscript denotes degrees of freedom, i.e. , not the usually assumed 100% chi(1); which leads to a conservative test). Such mixtures are sometimes called distributions. Simulations show that even with sequences as short as 125 sites, some parameters, including the proportion of invariant sites, fit asymptotic distributions closely.

Intra-operative hyaluronic acid clearance predicts postoperative graft function in living related liver transplantation

Although intra-operative hyaluronic acid (HA) clearance has been reported to be a predictive parameter for early graft function after the implantation of a cadaveric hepatic graft, it has yet to be evaluated as a parameter in assessing graft function in living related liver transplantation. The aim of this study was to evaluate whether intra-operative HA clearance can be a predictive parameter of early graft function in living related liver transplant patients. Eight consecutive patients, who underwent a living related liver transplantation, were entered into the study. The HA clearance 180 min after reperfusion of the graft was evaluated. Significantly higher serum HA levels were found in the patients with fulminant hepatitis than in the patients with non-fulminant hepatitis before operation (P < 0.01), just before reperfusion (P < 0.01), and 180 min after reperfusion (P < 0.05). The HA clearance correlated with the peak total bilirubin within 5 postoperative days (P < 0.05) and the lactic acid one day after operation (P < 0.01). The intra-operative HA clearance serves as a sensitive parameter for assessing the postoperative graft function after the implantation of the new liver. Based on our findings, measuring the HA clearance was thus found to be clinically useful in the assessment of graft function in living related liver transplantation.

Kinetics of selenium incorporation into tissues of female mallard ducks

Selenium is essential for both mammalian and avian species, although its metabolism in birds has been less thoroughly studied. Little information has been available on the kinetics of selenium in birds, especially as it relates to the teratogenicity seen in waterfowl consuming excessive amounts. This study describes the pharmacokinetics of small amounts of 75Se as selenious acid injected into female mallard ducks. Labeled selenium was injected into a wing vein of restrained animals and tissues taken at five different time points up to 24 h post-injection. Selenium levels as percent of injected dose were determined in liver, kidney, heart, lung, adrenals, thyroid, spleen, pancreas, ovaries, intestine, muscle and plasma. Estimates of kinetic parameters (uptake and elimination rates, time of maximum concentration and maximum concentration) were obtained with a non-linear kinetics computer program (PCNONLIN, SCI Software, Lexington, KY). Results showed four basic patterns of distribution, uptake and elimination. Visceral tissues exhibited a triphasic pattern with a rapid rise, a decline followed by a distinctive increase in levels between the last two time points. Brain uptake was continuous over the 24 h. Plasma rose rapidly and then declined to a constant level. The ovaries as a tissue of interest relating to the teratogenic effects of selenium showed the greatest relative increase at 24 h, suggesting kinetic mechanisms consistent with a pathway that might lead to accumulation of toxic levels and teratogenic effects during embryo development.

[Effects of anticoagulant therapy on retinal vein occlusion]

The combined effect of prostaglandin E1, stellate ganglion block, warfarin potassium and photocoagulation on 66 cases (eyes) of retinal vein occlusion was investigated immediately after, and 3 months and 6 months after final treatment. The time between onset and treatment was 2 months or less. Macular hemorrhage and edema were observed in all cases. The effectiveness rate 6 months after treatment was 35% in hemorrhagic central retinal vein occlusion and 63% in branch retinal vein occlusion. Visual acuity increased gradually with time from immediately after to 6 months after treatment. The effectiveness of treatment including warfarin potassium was lower than that of treatment without warfarin potassium in branch retinal vein occlusion, and many cases showed a marked decrease of visual acuity which might be related to the prolonged hemorrhage. These results suggest that combining prostaglandin E1, stellate ganglion block and photocoagulation in retinal vein occlusion produces better effects on visual acuity than ordinary treatment or spontaneous regression.

MRI changes and deficits of higher brain functions in preterm diplegia

Forty-one preterm children (29 with spastic diplegia and 12 without motor deficits) who had a normal verbal IQ were studied to clarify the clinical significance of neuroanatomical abnormalities disclosed by T1-weighted and T2-weighted magnetic resonance imaging (MRI). Both types of images clearly showed abnormalities in the frontal corona radiata of the children with spastic diplegia, while there were no abnormalities in the children without motor deficits. We compared the T1-weighted imaging findings with deficits of higher brain functions, evaluated by the performance subtests of the Wechsler Intelligence Scale. Thinning of the parietal and/or occipital white matter was noted in children with visuospatial cognitive deficits. Thus, MRI may be helpful in confirming early clinical suspicions of visuospatial cognitive deficits as well as motor deficits in preterm children, especially those with spastic diplegia.

Characterization of Tritrichomonas foetus antigens, using bovine antiserum

Tritrichomonas foetus antigens were identified, using the serum of an Angus heifer that had been repeatedly immunized with suspensions of 1 X 10(8) organisms in Freund's complete adjuvant. Antibody activity against T foetus was determined by dot-blot analysis, using horse-radish peroxidase-conjugated anti-bovine immunoglobulin to detect bound antibody. The antiserum contained antibodies against surface and flagellar components of live or fixed T foetus, as determined by use of immunofluorescence. The antiserum reacted with approximately 38 proteins in a pool of 55 to 60 components resolvable by polyacrylamide-gel electrophoresis of T foetus extracts.

Genetic relatedness of disease-associated field isolates of bovid herpesvirus type 4

Eight field isolates of bovid herpesvirus type 4 (BHV-4) were examined by restriction analysis and Southern blot hybridization with respect to their relatedness to one another and to the BHV-4 prototype strain DN-599. Isolates were obtained from cattle exhibiting a range of disease states including abortion, pneumonia, enteritis, metritis, and vaginal blisters. Initial growth studies of all 9 viruses were performed and revealed that the overall rate of virus growth was slow when compared with that of other herpesviruses. Infection with each virus also resulted in the formation of large fused cells, which in addition to the slow growth rate, indicated that the isolates were of the cytomegalovirus type. Further studies to characterize and compare the various BHV-4 isolates were undertaken by obtaining cell-free virus from infected cell populations. Viral isolates were purified and used as a source of BHV-4 DNA. Purified DNA, representing each of the 8 field isolates and the prototype strain DN-599, were each cleaved with 3 restriction enzymes and were separated by agarose-gel electrophoresis, and the resultant fragment patterns were compared. In general, genomic fragments of the field isolates corresponded to those generated by cleavage of DN-599 DNA, with the exception of the abortion-associated isolate 83-3572. Additional minor differences were also seen between DN-599 DNA and DNA from the other field isolates, but the overall restriction patterns were similar. To confirm that all isolates were members of the BHV-4 type, hybridization studies were performed using DN-599.(ABSTRACT TRUNCATED AT 250 WORDS)