Uncovering hypercoagulation status using rotational thromboelastometry in patients with sepsis presented with hypocoagulation based on conventional coagulation tests: an observational study.

OBJECTIVE: Conventional coagulation tests (CCTs) cannot identify hypercoagulation, despite being common in patients with sepsis. Moreover, CCTs overdiagnose hypocoagulation, which increases unnecessary blood transfusion. Therefore, we aimed to use rotational thromboelastometry (ROTEM) to classify the coagulation status of patients with sepsis with abnormal CCTs and to identify the main coagulation components that affect coagulation status. PATIENTS AND METHODS: This study was part of an observational study to investigate ROTEM use in 161 patients with sepsis with the Sepsis-3 criteria. They underwent concurrent CCTs and ROTEM assessments within 24 hours of Intensive Care Unit admission at the University Medical Center, Ho Chi Minh City, from June 2020 to December 2021. This study only extracted data from patients with sepsis with abnormal CCTs, including activated partial thromboplastin time ratio, international normalized ratio (INR), platelet count, and fibrinogen concentration. RESULTS: A total of 158 patients with sepsis with abnormal CCTs had a median age of 69, and 48.7% were women. Of 34 patients with INR ≥1.6, ROTEM identified 11.8% with hypercoagulation and 20.6% with normal coagulation. Of 29 patients with platelet counts <100 (103/mm3), ROTEM identified 3.5% with hypercoagulation and 24.1% with normal coagulation. In the ROTEM-based hypercoagulability group, an increase in maximum clot firmness was observed in 95.1% of cases; also, this group had significantly higher plasma fibrinogen concentrations than other groups (p<0.005). CONCLUSIONS: ROTEM can reveal hypercoagulability in patients with sepsis with hypocoagulation based on CCTs. Hyperfibrinogenemia causes hypercoagulation in patients with sepsis.

A new molecular imprinted PEDOT glassy carbon electrode for carbamazepine detection.

An electrochemical sensor for the detection of carbamazepine was fabricated by the electropolymerization of PEDOT on glassy carbon electrodes. Molecular imprinted polymer sites were synthesized by cyclic voltammetry on the electrodes' surfaces providing high selectivity and sensitivity towards carbamazepine molecules. Scanning electron microscopy validated the formation of the polymer. Extraction of carbamazepine from the polymer was performed by immersion in acetonitrile and validated by ultraviolet-visible spectroscopy along with cyclic voltammetry experiments comparing pre- and post-template extraction data. Further cyclic voltammetry and square-wave voltammetry tests aided in characterizing the electrodes' response to carbamazepine concentration in PBS solution with [Fe(CN)6]3-/4- as a redox pair/mediator. The limits of detection and quantification were found to be 0.98 x 10-3 M and 2.97 x 10-3 M respectively. The biosensor was highly sensitive to carbamazepine molecules in comparison to non-imprinted electrodes, simple to construct and easy to operate.

Unsupervised Clustering of HRV Features Reveals Preictal Changes in Human Epilepsy.

Over a third of patients suffering from epilepsy continue to live with recurrent disabling seizures and would greatly benefit from personalized seizure forecasting. While electroencephalography (EEG) remains most popular for studying subject-specific epileptic precursors, dysfunctions of the autonomous nervous system, notably cardiac activity measured in heart rate variability (HRV), have also been associated with epileptic seizures. This work proposes an unsupervised clustering technique which aims to automatically identify preictal HRV changes in 9 patients who underwent simultaneous electrocardiography (ECG) and intracranial EEG presurgical monitoring at the University of Montreal Hospital Center. A 2-class k-means clustering combined with a quantitative preictal HRV change detection technique were adopted in a subject- and seizure-specific manner. Results indicate inter and intra-patient variability in preictal HRV changes (between 3.5 and 6.5 min before seizure onset) and a statistically significant negative correlation between the time of change in HRV state and the duration of seizures (p<0.05). The presented findings show promise for new avenues of research regarding multimodal seizure prediction and unsupervised preictal time assessment.Clinical Relevance- This study proposed an unsupervised technique for quantitatively identifying preictal HRV changes which can be eventually used to implement an ECG-based seizure forecasting algorithm.

Reduced tubular degradation of glomerular filtered plasma albumin is a common feature in acute and chronic kidney disease.

Tubular epithelial cells take up and degrade plasma albumin filtered by the glomerulus. Tubular damage resulting in reduced albumin uptake or degradation has been suggested as one mechanism contributing to albuminuria in kidney disease. This study investigated whether tubular albumin uptake or degradation is altered in acute and chronic glomerular disease. Mouse models of acute glomerular injury (anti-GBM disease and LPS-induced albuminuria) and chronic disease (streptozotocin-induced diabetes and db/db mice) were examined. Mice were injected intravenously with Alexa-albumin plus DQ-albumin and killed 20 minutes later. Tubular uptake of albumin (Alexa-albumin) and albumin degradation (Dye Quenched (DQ)-albumin) was assessed in tissue sections via confocal microscopy. Tubular uptake of Alexa-albumin in the models of diabetic nephropathy was not different to normal mice. However, the fluorescence signal resulting from degradation of DQ-albumin was significantly reduced in db/db mice, and the ratio of degraded to intact albumin was reduced in both models. The ratio of degraded to intact albumin in tubules was also reduced in the anti-GBM model. In the LPS model, both tubular uptake and degradation of albumin were significantly reduced, with a substantial reduction in the ratio of degraded to intact albumin in tubules. LPS stimulation of cultured tubular epithelial cells inhibited albumin uptake, indicating a direct role for LPS in modifying tubular handling of albumin. In conclusion, reduced degradation of filtered albumin in the proximal tubule is a common feature of glomerular diseases. This may be a general mechanism whereby tubular dysfunction contributes to the development of albuminuria.

Multimodal investigation of epileptic networks: The case of insular cortex epilepsy.

The insula is a deep cortical structure sharing extensive synaptic connections with a variety of brain regions, including several frontal, temporal, and parietal structures. The identification of the insular connectivity network is obviously valuable for understanding a number of cognitive processes, but also for understanding epilepsy since insular seizures involve a number of remote brain regions. Ultimately, knowledge of the structure and causal relationships within the epileptic networks associated with insular cortex epilepsy can offer deeper insights into this relatively neglected type of epilepsy enabling the refining of the clinical approach in managing patients affected by it. In the present chapter, we first review the multimodal noninvasive tests performed during the presurgical evaluation of epileptic patients with drug refractory focal epilepsy, with particular emphasis on their value for the detection of insular cortex epilepsy. Second, we review the emerging multimodal investigation techniques in the field of epilepsy, that aim to (1) enhance the detection of insular cortex epilepsy and (2) unveil the architecture and causal relationships within epileptic networks. We summarize the results of these approaches with emphasis on the specific case of insular cortex epilepsy.

Effects of insular stimulation on thermal nociception.

BACKGROUND: Electrical stimulation used for brain mapping in the postero-superior insula can evoke pain. The effects of prolonged high frequency insular stimulation on pain thresholds are unknown. OBJECTIVE/HYPOTHESIS: Prolonged high frequency insular stimulation, by virtue of its inhibitory properties on networks, could decrease thermal nociception. METHODS: Epileptic subjects had electrodes implanted in the insular cortex for the purpose of epileptic focus resection. Thermal and pressure nociceptive thresholds were tested bilaterally on the forearm on two consecutive days. Randomly assigned double-blind high frequency (150 Hz) insular stimulation took place for 10 min before pain testing either on the first day or on the second day. RESULTS: Six subjects (three females; mean age of 35 years) were included. Insular stimulation increased heat pain threshold on the ipsilateral (p = 0.003; n = 6) and contralateral sides (p = 0.047; n = 6). Differences in cold pain threshold did not reach statistical significance (ipsilateral: p = 0.341, contralateral: p = 0.143; n = 6), but one subject had a profound decrease in both heat and cold pain responses. Pressure pain threshold was not modified by insular stimulation (ipsilateral: p = 0.1123; contralateral: p = 0.1192; n = 6). Two of the three subjects who had a postero-superior operculo-insulectomy developed central pain with contralateral thermal nociceptive deficit. CONCLUSIONS: High frequency inhibitory postero-superior insular stimulation may have the potential to decrease thermal nociception. Together with previous studies, our data support the notion that the integrity of this brain region is necessary for thermal but not pressure nociceptive processing.

A recurrent mutation in DEPDC5 predisposes to focal epilepsies in the French-Canadian population.

Familial focal epilepsy with variable foci (FFEVF) is a heterogeneous epilepsy syndrome originally described in the French-Canadian (FC) population. Mutations in DEPDC5 have recently been identified in multiple cases of FFEVF as well as in a wide spectrum of other familial focal epilepsies. In this study, we aimed to determine the frequency of mutation of this gene in our large cohort of FC individuals with FFEVF, as well as familial and sporadic cases with focal epilepsy. We report a recurrent p.R843X protein-truncating mutation segregating in one large FFEVF and two small focal epilepsy FC families. Fine genotyping suggests an ancestral allele. A new p.T864M variant, predicted to be disease-causing, was also identified in a small FC family. Overall, we identified DEPDC5 mutations in 5% of our familial and sporadic focal epilepsy cases (4/79). Our results support the view that mutations in the DEPDC5 gene are an important cause of autosomal dominant focal epilepsies in the FC population, including a founder mutation that is specific to this population. These findings may facilitate molecular diagnosis in clinical practice.

Structural abnormalities in patients with insular/peri-insular epilepsy: spectrum, frequency, and pharmacoresistance.

SUMMARY: Between 2002 and 2010, a total of 48 patients were seen at our epilepsy clinic with insular/peri-insular cortex epilepsy. Review of their MR imaging scans revealed a neoplastic lesion in 27% of patients, a malformation of cortical development in 21%, a vascular malformation in 19%, and atrophy/gliosis from an acquired insult in 17%. MR imaging results were normal in 4 patients. Other miscellaneous findings included a case of Rasmussen encephalitis, a nonspecific insular millimetric T2 signal abnormality, a neuroepithelial cyst, and hippocampal sclerosis without MR imaging evidence of dual insular pathologic features (despite depth electrode-proven insular seizures). Refractoriness to antiepileptic drug treatment was present in 56% of patients: 100% for patients with malformations of cortical development (1.0; 95% CI, 0.72-1.0), 50.0% (0.5; 95% CI, 0.21-0.78) in the presence of atrophy/gliosis from acquired insults, 39% (0.39; 95% CI, 0.14-0.68) for neoplastic lesions, and 22.2% (0.22; 95% CI, 0.06-0.55) for vascular malformations.

Insular ischemic stroke: clinical presentation and outcome.

BACKGROUND: The insula is a small but complex structure located in the depth of the sylvian fissure, covered by the frontal, parietal and temporal operculum. Ischemic strokes limited to the insula are rare and have not been well studied. Our objective is to better define the clinical presentation and outcome of insular ischemic strokes (IIS). METHODS: We reviewed the institutional prospective, consecutive stroke database from two centers to identify patients with IIS seen between 2008 and 2010. We also searched the Medline database using the keywords insula(r), infarction and stroke to identify previously published IIS cases confirmed by MRI. Minimal extension to an adjacent operculum or subinsular area was accepted. Clinicoradiological correlation was performed by distinguishing IIS involving the anterior (AIC) or posterior insular cortex (PIC). We collected clinical, demographic and radiological data. The outcome was determined using the modified Rankin Scale (mRS). RESULTS: We identified 7 patients from our institutions and 16 previously published cases of IIS. Infarcts were limited to the AIC (n = 4) or the PIC (n = 12) or affected both (n = 7). The five most frequent symptoms were somatosensory deficits (n = 10), aphasia (n = 10), dysarthria (n = 10), a vestibular-like syndrome (n = 8) and motor deficits (n = 6). A significant correlation was found between involvement of the PIC and somatosensory manifestations (p = 0.04). No other statistically significant associations were found. IIS presentation resembled a partial anterior circulation infarct (n = 9), a lacunar infarct (n = 2) or a posterior circulation infarct (n = 2). However, most cases presented findings that did not fit with these classical patterns (n = 10). At the 6 month follow up, mRS was 0 in 8/23 (35%) patients, 1-2 in 7/23 (30%) and unknown in 8/23 (35%). CONCLUSIONS: IIS presentation is variable. Due to the confluence of functions in a restricted region, it results in multimodal deficits. It should be suspected when vestibular-like or motor but especially somatosensory, speech or language disturbances are combined in the same patient. The outcome of IIS is often favorable. Larger prospective studies are needed to better define the clinical presentation and outcome of IIS.

Detection of hemodynamic responses to epileptic activity using simultaneous Electro-EncephaloGraphy (EEG)/Near Infra Red Spectroscopy (NIRS) acquisitions.

Simultaneous recordings of Electro-EncephaloGraphy (EEG) with Near InfraRed Spectroscopy (NIRS) allow measuring hemodynamic changes (changes in the concentration of oxy- and deoxyhemoglobin) at the time of epileptic discharges detected on scalp EEG. Two NIRS detection methods based on the General Linear Model (GLM) respectively in the time domain and in the time-frequency domain are investigated in this study using realistic simulations of spontaneous interictal epileptic activity. We evaluated the sensitivity at different Signal to Noise Ratios (SNR), the effect of either a large or a small number of discharges and the impact of model misspecification (e.g. omission or false detection of epileptic discharges). We also explored the effect on the estimation of key parameters, which set the model order. Simulations showed that both methods become inaccurate in lower SNR conditions, leading to many false positive detections. However, the time-frequency estimator showed better performance than the time-domain one. Key parameters for each algorithm were identified and results suggest to model confounds in the GLM differently for oxy- and deoxyhemoglobin. We also demonstrated that an inaccurate marking of epileptic events has a small impact on the detection statistics whereas an inaccurate specification of the hemodynamic response function delay decreases drastically the detection abilities. Finally, we illustrated the two methods on clinical EEG/NIRS data of one patient with focal epilepsy, showing an increase of regional Cerebral Blood Volume (rCBV) spatially concordant with the presumed epileptogenic focus.

A low-power high-sensitivity CMOS mixed-signal seizure-onset detector.

In this paper, we present a new seizure detection algorithm and the associated CMOS circuitry implementation. The proposed low-power seizure detector is a good candidate for an implantable epilepsy prosthesis. The device is designed for patient-specific seizure detection with a one variable parameter. The parameter value is extracted from a single seizure that is subsequently excluded from the validation phase. A two-path system is also proposed to minimize the detection delay. The algorithm is first validated using MATLAB® tools and then implemented and validated using circuits designed in a standard 0.18-µm CMOS process with a total power dissipation of 7.08 µW. A total of 13 seizures from two drug-resistant epileptic patients are assessed using the proposed algorithm and resulted in 100% sensitivity and a mean detection delay of 9.7 s after electrical onset.

EEG-fMRI: adding to standard evaluations of patients with nonlesional frontal lobe epilepsy.

OBJECTIVE: In patients with nonlesional frontal lobe epilepsy (FLE), the delineation of the epileptogenic zone is difficult. Therefore these patients are often not considered for surgery due to an unclear seizure focus. The aim of this study was to investigate whether EEG-fMRI can add useful information in the preoperative evaluation of these patients. METHODS: Nine nonlesional FLE patients were studied with EEG-fMRI using a 3 T scanner. Spike-related blood oxygen level dependent (BOLD) signal changes were compared to the topography of the spikes and to PET and SPECT results if available. The structural MRIs were reviewed for subtle abnormalities in areas that showed BOLD responses. For operated patients, postoperative resection and histology were compared to BOLD responses. RESULTS: Concordance between spike localization and positive BOLD response was found in 8 patients. PET and SPECT investigations corresponded with BOLD signal changes in 6 of 7 investigations. In 2 cases, reviewing the structural MRI guided by EEG-fMRI data resulted in considering a suspicious deep sulcus. Two patients were operated. In 1, the resected cortex corresponded with the suspicious sulcus and fMRI results and histology showed cortical dysplasia. In another, histology revealed an extended microdysgenesis not visible on structural MRI. EEG-fMRI had shown activation just adjacent to the resected pathologic area. CONCLUSIONS: Our study provides different types of support (topography, concordance with PET and SPECT, structural peculiarities, postoperative histology) that EEG-fMRI may help to delineate the epileptic focus in patients with nonlesional frontal lobe epilepsy, a challenging group in the preoperative evaluation.

[Insular epilepsy: The Montreal experience]. / L'épilepsie insulaire : l'expérience montréalaise.

In this article, we review recently published data on the role of the insula in refractory partial epilepsy and summarize our own experience in the investigation and treatment of this entity. Case studies and evoked responses obtained from insular cortical stimulation reveal a wide array of clinical manifestations which may mimic temporal, frontal or parietal lobe seizures. Clinicians should hence lower their threshold to sample the insula with intracerebral electrodes. Lack of recognition of insular seizures may explain part of epilepsy surgery failures. Advances in microneurosurgery open the way to safer insular resection.

Internal/external rotation moment arms of muscles at the knee: moment arms for the normal knee and the ACL-deficient knee.

Knowledge of the three-dimensional balance of loads at the knee joint is required to adequately assess the treatment and rehabilitation of the malfunctioning knee. This report focuses upon the moment arms for the knee in internal/external (IE) rotation motion. It augments prior work that defined flexion/extension moment arms. Muscle excursions and angular motion of the lower leg during IE rotation were measured in 17 fresh-frozen hemi-pelvis specimens. Moment arms were calculated as the derivatives of excursion with respect to the angle. Rotational motion was performed for the normal and anterior cruciate ligament (ACL)-deficient knee. Of the 13 muscles measured at the knee, seven were significant contributors to IE rotation: the biceps femoris long and short head externally rotate opposite the gracilis, sartorious, semimembranosis, semitendonosus and popliteus, functioning as internal rotators. Moment arm magnitudes were greatest with the knee in a flexed position (internal [external] rotators peaked at 70 degrees [90 degrees] flexion). At 30 degrees flexion, the IE rotation moment arm minima and maxima were 10.1-11.6, 6.8-9.0, 6.0-15.7, 8.2-14.1 and 0.0-10.4 mm for the semimembranosis, semitendonosus, gracilis, sartorius and popliteus, and 14.7-27.9 and 18.5-31.5 mm for the biceps femoris short and long, respectively. Moment arms for the ACL-deficient condition were significantly changed only at extremes of flexion-extension.

Differential toxicities of anticancer agents among DNA repair and checkpoint mutants of Saccharomyces cerevisiae.

Most cytotoxic anticancer agents damage DNA directly, interfere with DNA metabolism or chromosome segregation, and are particularly toxic in dividing cells. Although a considerable amount of information on the mechanisms of action of these agents is available, the molecular bases for selective tumor cell killing by chemotherapy are largely unknown. Many genetic alterations found in sporadic and hereditary cancers affect functions in DNA repair and cell cycle control and result in sensitivity to DNA damaging agents. We have therefore set out to determine the effects of these cancer mutations on sensitivity or resistance to various chemotherapeutic agents. Because most of the affected genes are well conserved among eukaryotes, we have carried out a comprehensive analysis of a panel of isogenic yeast strains, each defective in a particular DNA repair or cell cycle checkpoint function, for sensitivity to the Food and Drug Administration-approved cytotoxic anticancer agents. Widely different toxicity profiles were observed for 23 agents and X-rays, indicating that the type of DNA repair and cell cycle checkpoint mutations in individual tumors could strongly influence the outcome of a particular chemotherapeutic regimen.

The sex steroid binding protein (SBP or SHBG) of human plasma: identification of Tyr-57 and Met-107 in the steroid binding site.

Tyrosine-57 (Y57) and methionine-107 (M107) have been identified in the binding site of the sex steroid binding protein (SBP) (or sex hormone binding globulin) of human plasma by replacing the two amino acids with a number of residues of varying structure. Replacement of Y57 with phenylalanine resulted in a fourfold increase in the K(d) of 5 alpha-dihydrotestosterone but left the K(d) of 17 beta-estradiol unchanged. Except in two cases, no further loss in binding took place when replacing Y57 with other residues, suggesting that the phenolic group of Y57 may form a hydrogen bond with the ligand. Replacement of M107 with isoleucine increased the 5 alpha-dihydrotestosterone K(d) fourfold to a value equal to that of rabbit SBP, which contains isoleucine at the corresponding position; however, the K(d) of 17 beta-estradiol remained unchanged. Replacement of M107 with threonine resulted in a tenfold decrease in 5 alpha-dihydrotestosterone binding affinity, whereas replacement with leucine left the K(d) unchanged. These data indicate that substitutions on the beta-carbon of the amino acid side-chain at position 107 causes significant loss of binding affinity but, as in the case of Y57, the activity was not totally eliminated. We conclude that Y57 and M107 form part of a structural motif within the steroid binding site and specifically contribute binding energy to ring A of 5 alpha-dihydrotestosterone but not to ring A of 17 beta-estradiol. We also propose that the integrated contribution of several side chains may be required to optimize the ligand affinity of the steroid binding site. This proposal may fit a 'lock and key' model where little movement of the side chains occurs during binding as might be expected for a rigid structure like the steroid nucleus.

Pain and the Guillain-Barré syndrome in children under 6 years old.

During a 15-year period, 29 children, under the age of 6 years, with acute Guillain-Barré syndrome were seen at our institution. A review of their charts revealed that pain was a symptom in all patients and was present on admission in 79% of cases. Pain was often the most important symptom and led to misdiagnosis in 20 patients (69%). In 11 of these children, symptoms were present for more than a week before the correct diagnosis was made. The most common pain syndrome was back and lower limb pain, present in 83% of patients. Pediatricians should consider Guillain-Barré syndrome in their differential diagnosis when faced with a child who has lower limb pain and areflexia.

Lovastatin biosynthesis in Aspergillus terreus: characterization of blocked mutants, enzyme activities and a multifunctional polyketide synthase gene.

BACKGROUND: Lovastatin, an HMG-CoA reductase inhibitor produced by the fungus Aspergillus terreus, is composed of two polyketide chains. One is a nonaketide that undergoes cyclization to a hexahydronaphthalene ring system and the other is a simple diketide, 2-methylbutyrate. Fungal polyketide synthase (PKS) systems are of great interest and their genetic manipulation should lead to novel compounds. RESULTS: An A. terreus mutant (BX102) was isolated that could not synthesize the nonaketide portion of lovastatin and was missing a approximately 250 kDa polypeptide normally present under conditions of lovastatin production. Other mutants produced lovastatin intermediates without the methylbutyryl sidechain and were missing a polypeptide of approximately 220 kDa. The PKS inhibitor cerulenin reacted covalently with both polypeptides. Antiserum raised against the approximately 250 kDa polypeptide was used to isolate the corresponding gene, which complemented the BX102 mutation. The gene encodes a polypeptide of 269 kDa containing catalytic domains typical of vertebrate fatty acid and fungal PKSs, plus two additional domains not previously seen in PKSs: a centrally located methyltransferase domain and a peptide synthetase elongation domain at the carboxyl terminus. CONCLUSIONS: The results show that the nonaketide and diketide portions of lovastatin are synthesized by separate large multifunctional PKSs. Elucidation of the primary structure of the PKS that forms the lovastatin nonaketide, as well as characterization of blocked mutants, provides new details of lovastatin biosynthesis.