In Vitro Biosynthetic Pathway Investigations of Neuroprotectin D1 (NPD1) and Protectin DX (PDX) by Human 12-Lipoxygenase, 15-Lipoxygenase-1, and 15-Lipoxygenase-2.

In this paper, human platelet 12-lipoxygenase [h12-LOX (ALOX12)], human reticulocyte 15-lipoxygenase-1 [h15-LOX-1 (ALOX15)], and human epithelial 15-lipoxygenase-2 [h15-LOX-2 (ALOX15B)] were observed to react with docosahexaenoic acid (DHA) and produce 17S-hydroperoxy-4Z,7Z,10Z,13Z,15E,19Z-docosahexaenoic acid (17S-HpDHA). The kcat/KM values with DHA for h12-LOX, h15-LOX-1, and h15-LOX-2 were 12, 0.35, and 0.43 s-1 µM-1, respectively, which demonstrate h12-LOX as the most efficient of the three. These values are comparable to their counterpart kcat/KM values with arachidonic acid (AA), 14, 0.98, and 0.24 s-1 µM-1, respectively. Comparison of their product profiles with DHA demonstrates that the three LOX isozymes produce 11S-HpDHA, 14S-HpDHA, and 17S-HpDHA, to varying degrees, with 17S-HpDHA being the majority product only for the 15-LOX isozymes. The effective kcat/KM values (kcat/KM × percent product formation) for 17S-HpDHA of the three isozymes indicate that the in vitro value of h12-LOX was 2.8-fold greater than that of h15-LOX-1 and 1.3-fold greater than that of h15-LOX-2. 17S-HpDHA was an effective substrate for h12-LOX and h15-LOX-1, with four products being observed under reducing conditions: protectin DX (PDX), 16S,17S-epoxy-4Z,7Z,10Z,12E,14E,19Z-docosahexaenoic acid (16S,17S-epoxyDHA), the key intermediate in neuroprotection D1 biosynthesis [NPD1, also known as protectin D1 (PD1)], 11,17S-diHDHA, and 16,17S-diHDHA. However, h15-LOX-2 did not react with 17-HpDHA. With respect to their effective kcat/KM values, h12-LOX was markedly less effective than h15-LOX-1 in reacting with 17S-HpDHA, with a 55-fold lower effective kcat/KM in producing 16S,17S-epoxyDHA and a 27-fold lower effective kcat/KM in generating PDX. This is the first direct demonstration of h15-LOX-1 catalyzing this reaction and reveals an in vitro pathway for PDX and NPD1 intermediate biosynthesis. In addition, epoxide formation from 17S-HpDHA and h15-LOX-1 was negatively affected via allosteric regulation by 17S-HpDHA (Kd = 5.9 µM), 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12S-HETE) (Kd = 2.5 µM), and 17S-hydroxy-13Z,15E,19Z-docosatrienoic acid (17S-HDTA) (Kd = 1.4 µM), suggesting a possible regulatory pathway in reducing epoxide formation. Finally, 17S-HpDHA and PDX inhibited platelet aggregation, with EC50 values of approximately 1 and 3 µM, respectively. The in vitro results presented here may help advise in vivo PDX and NPD1 intermediate (i.e., 16S,17S-epoxyDHA) biosynthetic investigations and support the benefits of DHA rich diets.

Mutagenesis, Hydrogen-Deuterium Exchange, and Molecular Docking Investigations Establish the Dimeric Interface of Human Platelet-Type 12-Lipoxygenase.

It was previously shown that human platelet 12S-lipoxygenase (h12-LOX) exists as a dimer; however, the specific structure is unknown. In this study, we create a model of the dimer through a combination of computational methods, experimental mutagenesis, and hydrogen-deuterium exchange (HDX) investigations. Initially, Leu183 and Leu187 were replaced by negatively charged glutamate residues and neighboring aromatic residues were replaced with alanine residues (F174A/W176A/L183E/L187E/Y191A). This quintuple mutant disrupted both the hydrophobic and π-π interactions, generating an h12-LOX monomer. To refine the determinants for dimer formation further, the L183E/L187E mutant was generated and the equilibrium shifted mostly toward the monomer. We then submitted the predicted monomeric structure to protein-protein docking to create a model of the dimeric complex. A total of nine of the top 10 most energetically favorable docking conformations predict a TOP-to-TOP dimeric arrangement of h12-LOX, with the α-helices containing a Leu-rich region (L172, L183, L187, and L194), corroborating our experimental results showing the importance of these hydrophobic interactions for dimerization. This model was supported by HDX investigations that demonstrated the stabilization of four, non-overlapping peptides within helix α2 of the TOP subdomain for wt-h12-LOX, consistent with the dimer interface. Most importantly, our data reveal that the dimer and monomer of h12-LOX have distinct biochemical properties, suggesting that the structural changes due to dimerization have allosteric effects on active site catalysis and inhibitor binding.

Hemogram parameters can predict in-hospital mortality of patients with Myasthenic crisis.

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disease involving the neuromuscular junction. Myasthenic crisis (MC), which is characterized by respiratory failure and the requirement of mechanical ventilation in patients with MG, is still a medical emergency despite the decrease in mortality with the advances in acute management. Hemogram is a cost-effective test for evaluating hematological complications and systemic inflammation, and hemogram data have been used to predict various clinical outcomes of several diseases. The relationship between hemogram and MG has been discussed, but the role of hemogram data in predicting the prognosis of MC patients has not been established. METHODS: To identify whether hemogram data can predict in-hospital mortality in patients with MC, we retrospectively investigated 188 myasthenic crisis events from the Chang Gung Research Database between April 2001 and March 2019. Demographic and clinical characteristics were collected, as well as hemogram data before intubation and extubation. The endpoints were mortality during mechanical ventilation and mortality after extubation. RESULTS: The overall in-hospital mortality rate was 22%. Multivariate logistic regression analysis for predicting mortality during mechanical ventilation showed that old age at MC onset (OR = 1.039, p = 0.022), moderate-to-severe anemia (OR = 5.851, p = 0.001), and extreme leukocytosis (OR = 5.659, p = 0.022) before intubation were strong predictors of mortality, while acute management with plasma exchange or double-filtration plasmapheresis (PE/DFPP) significantly decreased mortality (OR = 0.236, p = 0.012). For predicting mortality after extubation, moderate-to-severe anemia before extubation (OR = 8.452, p = 0.017) and non-treated with disease-modifying therapy before MC (OR = 5.459, p = 0.031) were crucial predictive factors. CONCLUSION: This study demonstrated that both old age at MC onset and moderate-to-severe anemia are important predictors of in-hospital mortality in patients with MC, and extreme leukocytosis is another crucial predictor of mortality during mechanical ventilation. The suggested mechanism is that anemia-induced hypoxia may enhance the release of proinflammatory cytokines, exacerbate systemic inflammation, and lead to multiple organ dysfunction syndrome and, finally, mortality.

Docking and mutagenesis studies lead to improved inhibitor development of ML355 for human platelet 12-lipoxygenase.

Human platelet 12-(S)-Lipoxygenase (12-LOX) is a fatty acid metabolizing oxygenase that plays an important role in platelet activation and cardiometabolic disease. ML355 is a specific 12-LOX inhibitor that has been shown to decrease thrombosis without prolonging hemostasis and protect human pancreatic islets from inflammatory injury. It has an amenable drug-like scaffold with nM potency and encouraging ADME and PK profiles, but its binding mode to the active site of 12-LOX remains unclear. In the current work, we combined computational modeling and experimental mutagenesis to propose a model in which ML355 conforms to the "U" shape of the 12-LOX active site, with the phenyl linker region wrapping around L407. The benzothiazole of ML355 extends into the bottom of the active site cavity, pointing towards residues A417 and V418. However, reducing the active site depth alone did not affect ML355 potency. In order to lower the potency of ML355, the cavity needed to be reduced in both length and width. In addition, H596 appears to position ML355 in the active site through an interaction with the 2-methoxy phenol moiety of ML355. Combined, this binding model suggested that the benzothiazole of ML355 could be enlarged. Therefore, a naphthyl-benzothiazole derivative of ML355, Lox12Slug001, was synthesized and shown to have 7.2-fold greater potency than ML355. This greater potency is proposed to be due to additional van der Waals interactions and pi-pi stacking with F414 and F352. Lox12Slug001 was also shown to be highly selective against 12-LOX relative to the other LOX isozymes and more importantly, it showed activity in rescuing human islets exposed to inflammatory cytokines with comparable potency to ML355. Further studies are currently being pursued to derivatize ML355 in order to optimize the additional space in the active site, while maintaining acceptable drug-like properties.

Kinetic and structural investigations of novel inhibitors of human epithelial 15-lipoxygenase-2.

Human epithelial 15-lipoxygenase-2 (h15-LOX-2, ALOX15B) is expressed in many tissues and has been implicated in atherosclerosis, cystic fibrosis and ferroptosis. However, there are few reported potent/selective inhibitors that are active ex vivo. In the current work, we report newly discovered molecules that are more potent and structurally distinct from our previous inhibitors, MLS000545091 and MLS000536924 (Jameson et al, PLoS One, 2014, 9, e104094), in that they contain a central imidazole ring, which is substituted at the 1-position with a phenyl moiety and with a benzylthio moiety at the 2-position. The initial three molecules were mixed-type, non-reductive inhibitors, with IC50 values of 0.34 ±â€¯0.05 µM for MLS000327069, 0.53 ±â€¯0.04 µM for MLS000327186 and 0.87 ±â€¯0.06 µM for MLS000327206 and greater than 50-fold selectivity versus h5-LOX, h12-LOX, h15-LOX-1, COX-1 and COX-2. A small set of focused analogs was synthesized to demonstrate the validity of the hits. In addition, a binding model was developed for the three imidazole inhibitors based on computational docking and a co-structure of h15-LOX-2 with MLS000536924. Hydrogen/deuterium exchange (HDX) results indicate a similar binding mode between MLS000536924 and MLS000327069, however, the latter restricts protein motion of helix-α2 more, consistent with its greater potency. Given these results, we designed, docked, and synthesized novel inhibitors of the imidazole scaffold and confirmed our binding mode hypothesis. Importantly, four of the five inhibitors mentioned above are active in an h15-LOX-2/HEK293 cell assay and thus they could be important tool compounds in gaining a better understanding of h15-LOX-2's role in human biology. As such, a suite of similar pharmacophores that target h15-LOX-2 both in vitro and ex vivo are presented in the hope of developing them as therapeutic agents.

Mycobacterium gordonae infection in immunocompromised and immunocompetent hosts: A series of seven cases and literature review.

BACKGROUND/PURPOSE: Mycobacterium gordonae is a ubiquitous environmental mycobacteria and has been long considered an opportunistic pathogen, causing infections only in immunocompromised hosts. Cases of M. gordonae related infections in immunocompetent host have rarely been reported, and the pathogenicity of M. gordonae remained uncertain. METHODS: From January 2016 to December 2018, seven cases of M. gordonae infection were diagnosed and treated at National Taiwan University Hospital. RESULTS: Six cases had at least one underlying disease affecting immune status, while one case had no identifiable underlying disease. The sites of infection were lung (n = 3), skin and soft tissue (n = 3), and one had disseminated disease involving the lung and bone marrow. All patients were cured after anti-mycobacterial treatment, except one patient died of refractory leukemia. CONCLUSION: Compatible with the literature reports, we demonstrate that M. gordonae could be pathogenic and causing infection not only in the immunocompromised host, but also in the otherwise healthy population. Multi-antimicrobial combination and adequate source control could have good therapeutic effect for patients with M. gordonae infections.

The Clinical Features and Therapeutic Outcomes of Young Adults with Cryptococcal Meningitis.

OBJECTIVE: No previous study has reported on the clinical characteristics of cryptococcal meningitis (CM) focusing solely on young adults. PATIENTS AND METHODS: Ninety-nine adult patients with CM (64 men and 35 women) were enrolled, of whom 26 were classified into the young adult group (≤ 40 years) and 73 into the non-young adult group (> 40 years). The modified Rankin scale (mRS) was used to evaluate the outcomes of the survivors at the time of discharge and at 1 year of follow-up. The clinical characteristics and laboratory data between 1) the young adult CM patients with and without acquired immunecompromised syndrome and 2) the male and female young adult CM patients were compared. The prognostic factors of the young adult CM patients were also analyzed. RESULTS: The young adult group had a higher incidence of headache as the clinical presentation which may have been due to the higher intracranial pressure in this group. The overall mortality rate of the young adults with CM was high (38.5%, 10/26), but no significant prognostic factors were found. In followup studies of the neurologic deficits, the young adult survivors had better outcomes (mRS scores = 0-2) than the non-young adult group at discharge and 1 year after discharge. CONCLUSION: The young adult CM patients had a higher incidence of headache as the clinical presentation. Although the mortality rate in the young adult CM patients was high, the survivors had better neurologic outcomes.

Neuropsychiatric symptoms in Parkinson's disease: association with caregiver distress and disease severity.

OBJECTIVES: The condition of caregivers is important to the quality of care received by people with Parkinson's disease (PD), especially at the late disease stages. This study addresses the distress placed on caregivers by participants' neuropsychiatric symptoms at different stages of PD in Taiwan. METHODS: This prospective study enrolled 108 people with PD. All participants were examined with the Unified Parkinson's Disease Rating Scale (UPDRS), Neuropsychiatric Inventory (NPI), Mini-Mental State Examination (MMSE), Cognitive Abilities Screening Instrument (CASI), and Clinical Dementia Rating (CDR) scale. Caregiver distress was measured using the Neuropsychiatric Inventory Caregiver Distress Scale (NPI-D). Statistical analysis was used to explore the PD-related factors that contribute to caregiver distress. RESULTS: The mean follow-up interval in the 108 PD participants were 24.0 ± 10.2 months with no participant lost to follow-up due to death. NPI-distress (the sum of NPI caregiver distress scale across the 12 domains of the NPI) was positively correlated with NPI-sum (the total score across the 12 domains of the NPI) (r = 0.787, p < 0.001), CDR (r = 0.403, p < 0.001), UPRDS (r = 0.276, p = 0.004), and disease duration (r = 0.246, p = 0.002), but negatively correlated with CASI (r = -0.237, p = 0.043) and MMSE (r = -0.281, p < 0.001). Multiple linear regression analysis showed that only NPI-sum and disease duration were independently correlated with NPI-distress. CONCLUSION: The disease duration and NPI-sum are independent predictors of caregiver distress in Taiwanese populations with PD. Early detection and reduction of neuropsychiatric symptoms in people with PD can help decrease caregiver distress.

Probing the Electrostatic and Steric Requirements for Substrate Binding in Human Platelet-Type 12-Lipoxygenase.

Human platelet ALOX12 (hALOX12 or h12-LOX) has been implicated in a variety of human diseases. The present study investigates the active site of hALOX12 to more thoroughly understand how it positions the substrate and achieves nearly perfect regio- and stereospecificities (i.e., 100 ± 5% of the 12(S)-hydroperoxide product), utilizing site-directed mutagenesis. Specifically, we have determined that Arg402 is not as important in substrate binding as previously seen for hALOX15 but that His596 may play a role in anchoring the carboxy terminal of the arachidonic acid during catalysis. In addition, Phe414 creates a π-stacking interaction with a double bond of arachidonic acid (Δ11), and Ala417/Val418 define the bottom of the cavity. However, the influence of Ala417/Val418 on the profile is markedly less for hALOX12 than that seen in hALOX15. Mutating these two residues to larger amino acids (Ala417Ile/Val418Met) only increased the generation of 15-HpETE by 24 ± 2%, but conversely, smaller residues at these positions converted hALOX15 to almost 100% hALOX12 reactivity [Gan et al. (1996) J. Biol. Chem. 271, 25412-25418]. However, we were able to increase 15-HpETE to 46 ± 3% by restricting the width of the active site with the Ala417Ile/Val418Met/Ser594Thr mutation, indicating both depth and width of the active site are important. Finally, residue Leu407 is shown to play a critical role in positioning the substrate correctly, as seen by the increase of 15-HpETE to 21 ± 1% for the single Leu407Gly mutant. These results outline critical differences between the active site requirements of hALOX12 relative to hALOX15 and explain both their product specificity and inhibitory differences.

Impact of antiretroviral therapy containing tenofovir disoproxil fumarate on the survival of patients with HBV and HIV coinfection.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) is active against both HBV and HIV. Whether the introduction of TDF-containing combination antiretroviral therapy (cART) has improved the outcome of HIV/HBV-coinfected patients remains unclear in areas of higher HBV endemicity. METHODS: We retrospectively reviewed medical records of newly diagnosed antiretroviral-naïve HIV-infected patients between 2007 and 2015. Four groups of patients were defined, according to the HBV status and availability of TDF for HIV treatment in Taiwan in 2011. The primary outcome was all-cause mortality. RESULTS: During the 9-year study period, 1,723 HIV-infected patients were included, with a median age of 31 years and baseline CD4 count of 273 cells per µL. The HBV seroprevalence had declined from 18.1% (125/692) in the pre-TDF era to 10.1% (104/1031) in the post-TDF era. The respective mortality rate for HIV/HBV-coinfected and HIV-monoinfected patients in the pre-TDF era was 23.2 (95% CI, 12.5-43.1) and 9.6 (95% CI, 6.1-15.0) deaths per 1000 person-years of follow-up [PYFU], and the respective mortality rate in the post-TDF era was 15.7 (95% CI, 7.0-34.8) and 8.0 (95% CI, 5.5-11.6) deaths per 1000 PYFU. The adjusted hazard ratio for mortality in multivariate Cox proportional-hazards regression analysis among HIV/HBV-coinfected patients compared to HIV-monoinfected patients was 2.79 (95% CI, 1.25-6.22) in pre-TDF era and 1.11 (95% CI, 0.45-2.72) in post-TDF era. CONCLUSIONS: In this country of high HBV endemicity, the adverse impact of chronic HBV infection on the survival observed in the pre-TDF era has significantly diminished among HIV/HBV-coinfected patients compared to HIV-monoinfected patients in the era of TDF-containing cART.

The clinical characteristics and therapeutic outcomes of cryptococcal meningitis in elderly patients: a hospital-based study.

BACKGROUND: The elderly, and especially those with an immuno-compromised status, are vulnerable to infectious diseases. The purpose of this study was to examine the clinical characteristics and therapeutic outcomes of cryptococcal meningitis (CM) in elderly patients in Taiwan. METHODS: Ninety-nine adult patients with CM were identified during a 15-year study period (2002-2016), of whom 38 elderly (≥ 65 years) patients (16 men and 22 women, median age 72.9 years; range 65-86 years) were included for analysis. The clinical characteristics and therapeutic outcomes of these patients were analyzed and compared to non-elderly adult patients (< 65 years) with CM. RESULTS: Among the 38 patients, diabetes mellitus was the most common underlying condition (15), followed by adrenal insufficiency (7), malignancy (6), hematologic disorders (5), chronic obstructive pulmonary disease (5), autoimmune diseases (3), liver cirrhosis (3) and acquired immunodeficiency syndrome (1). Altered consciousness (29), fever (21) and headache (17) were the leading clinical manifestations. Positive cerebrospinal fluid and blood cultures for Cryptococcus (C.) neoformans were found in 26 and 9 patients, respectively. There were significant differences in gender, altered consciousness and recent cerebral infarction between the elderly and non-elderly groups. The elderly group had a high mortality rate (36.8%, 14/38), and the presence of cryptococcemia was the most significant prognostic factor. CONCLUSIONS: This study offers a preliminary view of the clinical characteristics of CM in the elderly. The results suggest that elderly patients (≥ 65 years) are more vulnerable to CM than adults aged < 65 years. Compared to the non-elderly group, the elderly group had female predominance, higher rates of altered consciousness and recent cerebral infarction as the clinical presentation. The presence of cryptococcemia was a significant prognostic factor in the elderly group. This study is limited by the small number of patients, and further large-scale studies are needed to better delineate this specific infectious syndrome.

Perampanel Treatment for Refractory Status Epilepticus in a Neurological Intensive Care Unit.

BACKGROUND/OBJECTIVE: Perampanel is a novel anti-epileptic drug (AED) which acts as a non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist to reduce glutamate-mediated postsynaptic excitation. Previous animal studies and a few case reports/series have suggested that it may be effective to treat refractory status epilepticus (RSE). METHODS: We retrospectively reviewed 67 consecutive patients with RSE, of whom 22 received perampanel. The clinical features, epidemiology-based mortality score in status epilepticus, status epilepticus severity score, seizure control, functional outcome, RSE etiology, and electroencephalogram findings were collected. Responder to perampanel was defined as seizure resolution within 4 days of therapy with perampanel being the last AED used plus no recurrence during hospitalization. RESULTS: Eight of the 22 (36.4%) RSE patients fulfilled the definition of responder to perampanel. An additional 1 patient responded to perampanel after 4 days of treatment. In total, perampanel was the last AED in 9 (40.1%) patients. Among the 8 responders to perampanel, 5 had convulsive SE, 1 had non-convulsive SE, and 2 had focal motor SE. The responders accounted for both of the patients with focal motor SE (100%), 5 (33.3%) of the 15 patients with convulsive SE, and 1 (20%) of the 5 patients with non-convulsive SE. The ictal and inter-ictal activities also decreased after perampanel therapy, and three patients (13.6%) had preferable outcomes at last follow-up. CONCLUSIONS: Perampanel may be an effective add-on treatment for RSE even in patients who failed multiple AEDs. Our study suggests that perampanel may be more effective for focal motor SE and convulsive SE than non-convulsive SE. As most previous studies have focused on non-convulsive SE, further studies are warranted to clarify the effectiveness of perampanel for different subtypes of SE.

B1 Field Correction of T1 Estimation Should Be Considered for Breast Dynamic Contrast-enhanced MR Imaging Even at 1.5 T.

Purpose To prospectively quantify the effect of T1 estimation in fat by B1 correction in breast magnetic resonance (MR) imaging at 1.5 T and to examine the subsequent quantitative dynamic contrast material-enhanced parameters in breast cancer with and without B1 correction. Materials and Methods This study had institutional review board approval, and informed consent was obtained from 72 patients with breast cancer before breast MR imaging studies were performed between January and July 2015. B1+ field and variable flip angle (FA) mapping were included in the dynamic contrast-enhanced breast MR imaging protocol with a 1.5-T MR imaging system. Precontrast T1 relaxation in fat and breast tumors was computed with and without B1 correction. The pharmacokinetic parameters of breast cancer were calculated by using the Tofts model with T1 values before and after B1 correction. The Mann-Whitney U test and linear regression model were used for statistical analysis. Results The FA was 19% higher in the left breast and 3% lower in the right breast than the prescribed value. This 22% average FA difference created a 43% T1 estimation bias in fat between the breasts. The T1 variation in fat was reduced to 0.96% after B1 correction. There was a 50% overestimation and a 7% underestimation of tumor T1 in the left breast and the right, respectively, associated with B1 error. Assuming T1 after B1 correction represents the true tumor T1, 41% underestimation in the left breast and 10% overestimation in the right without B1 correction were seen in the dynamic contrast-enhanced parameters (including the volume transfer constant, or Ktrans, fraction of extracellular extravascular space, or ve, and blood normalized initial area under the gadolinium concentration curve to 90 seconds, or IAUGCBN90). Conclusion B1 correction for more accurate T1 values should be considered for quantitative dynamic contrast-enhanced breast MR imaging, even at 1.5 T, to offset significant systemic error. © RSNA, 2016.

Genetic effect of interleukin-1 beta (C-511T) polymorphism on the structural covariance network and white matter integrity in Alzheimer's disease.

BACKGROUND: Inflammatory processes play a pivotal role in the degenerative process of Alzheimer's disease. In humans, a biallelic (C/T) polymorphism in the promoter region (position-511) (rs16944) of the interleukin-1 beta gene has been significantly associated with differences in the secretory capacity of interleukin-1 beta. In this study, we investigated whether this functional polymorphism mediates the brain networks in patients with Alzheimer's disease. METHODS: We enrolled a total of 135 patients with Alzheimer's disease (65 males, 70 females), and investigated their gray matter structural covariance networks using 3D T1 magnetic resonance imaging and their white matter macro-structural integrities using fractional anisotropy. The patients were classified into two genotype groups: C-carriers (n = 108) and TT-carriers (n = 27), and the structural covariance networks were constructed using seed-based analysis focusing on the default mode network medial temporal or dorsal medial subsystem, salience network and executive control network. Neurobehavioral scores were used as the major outcome factors for clinical correlations. RESULTS: There were no differences between the two genotype groups in the cognitive test scores, seed, or peak cluster volumes and white matter fractional anisotropy. The covariance strength showing C-carriers > TT-carriers was the entorhinal-cingulum axis. There were two peak clusters (Brodmann 6 and 10) in the salience network and four peak clusters (superior prefrontal, precentral, fusiform, and temporal) in the executive control network that showed C-carriers < TT-carriers in covariance strength. The salience network and executive control network peak clusters in the TT group and the default mode network peak clusters in the C-carriers strongly predicted the cognitive test scores. CONCLUSIONS: Interleukin-1 beta C-511 T polymorphism modulates the structural covariance strength on the anterior brain network and entorhinal-interconnected network which were independent of the white matter tract integrity. Depending on the specific C-511 T genotype, different network clusters could predict the cognitive tests.

Status epilepticus associated with pregnancy: A cohort study.

BACKGROUND: Status epilepticus (SE) is a neurological emergency associated with a high mortality rate and long-term cognitive sequelae. Status epilepticus in pregnancy poses a tremendous threat to both mother and fetus, making a correct diagnosis and treatment a challenging task for clinicians. The prevalence, underlying etiology, and outcomes of pregnancy-related SE remain largely unknown. METHODS: We retrospectively studied all SE episodes (n=366) in patients admitted to our neurological ICU over a period of 8.5years. The patients who developed SE during pregnancy and within 6months after delivery were considered to have pregnancy-related SE. Patients with eclampsia were not included as they were usually cared for in our obstetric unit. RESULTS: Seven patients with pregnancy-related SE were identified (2.1% of all cases of SE), with the majority (85%) occurring de novo except for one patient who had a previous history of epilepsy-related SE due to withdrawal of antiepileptic medication. In terms of etiology, limbic encephalitis and cerebral venous sinus thrombosis were the two main etiologies of de novo SE associated with pregnancy. The overall mortality rate was 28.5% at discharge, and poor outcomes were especially noted in the patients with limbic encephalitis compared to other etiologies. CONCLUSIONS: Pregnancy-associated SE is rare and predominantly occurs in patients without a history of epilepsy. An autoimmune etiology should be considered in pregnant patients with de novo SE, which was associated with poor outcomes. Thorough investigations and prompt treatment according to the etiology may be required to improve the final outcomes of both mother and fetus.

Predictors and long-term outcome of seizures in human immuno-deficiency virus (HIV)-negative cryptococcal meningitis.

BACKGROUND: Seizures are one of the most important neurologic complications of human immuno-deficiency virus (HIV)-negative cryptococcal meningitis. A better understanding of the risk associated factors can help predict those who will require treatment. METHODS: This 22-year retrospective study enrolled 180 patients. Prognostic variables independently associated with seizures or fatality were analyzed using stepwise logistic regression. RESULTS: Twenty-eight patients with HIV-negative cryptococcal meningitis had seizures, including 13 with early seizures and 15 with late seizures. The mean time interval from HIV-negative cryptococcal meningitis to first seizure in the early and late seizure groups were 1.5 and 51.4 days, respectively. Nine out of the 28 cases (32%) occurred within 24 hours of presentation. The overall mortality rate was 54% (15/28) and two patients progressed to epilepsy. CONCLUSIONS: Patients with seizure have worse outcomes and longer hospitalization. Most first seizures occur within one year after the diagnosis of HIV-negative cryptococcal meningitis.

Churg-Strauss Syndrome Following Vaccination Against 2010 Influenza A (H1N1): A Case Report.

PURPOSE AND BACKGROUND: Churg-Strauss syndrome (CSS) is a systemic inflammatory disorder characterized by asthma, transient pulmonary infiltration, hyper-eosinophilia, and systemic vasculitis. Reported triggering factors include infections, drugs, allergic desensitization, and vaccinations, although cases involving the latter two are extremely rare. Herein, we describe a patient who developed CSS after receiving an H1N1 vaccination. CASE REPORT: A 55-year-old woman presented with fever, skin eruptions, and sensory impairment of her feet within one week after an H1N1 vaccine injection. A chest X-ray showed pulmonary infiltrations in both lower lung fields. Eosinophilia was noted in a hematological test, and an electrophysiological study revealed a pattern of mononeuritis multiplex. A skin biopsy was performed which revealed palisading necrotizing granuloma around a degenerated dermis and eosinophilic infiltration of the blood vessel walls. These findings combined with the hematological and electrophysiological findings met the criteria of CSS according to the American College of Rheumatology. The patient recovered well after steroid treatment. CONCLUSION: This case highlights the possibility that the H1N1 vaccination can trigger CSS. Due to the rarity of reported autoimmune events after vaccine administration and the obscure causal association between autoimmunity and a vaccine, further post-marketing surveillance and research are necessary to clarify the relationship and identify risk factors.

Effect of early dexamethasone on outcomes of COVID-19: A quasi-experimental study using propensity score matching.

BACKGROUND: The RECOVERY trial demonstrated that the use of dexamethasone is associated with a 36% lower 28-day mortality in hospitalized patients with COVID-19 on invasive mechanical ventilation. Nevertheless, the optimal timing to start dexamethasone remains uncertain. METHODS: We conducted a quasi-experimental study at National Taiwan University Hospital (Taipei, Taiwan) using propensity score matching to simulate a randomized controlled trial to receive or not to receive early dexamethasone (6 mg/day) during the first 7 days following the onset of symptoms. Treatment was standard protocol-based, except for the timing to start dexamethasone, which was left to physicians' decision. The primary outcome is 28-day mortality. Secondary outcomes include secondary infection within 60 days and fulfilling the criteria of de-isolation within 20 days. RESULTS: A total of 377 patients with COVID-19 were enrolled. Early dexamethasone did not decrease 28-day mortality in all patients (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.97-1.10) or in patients who required O2 for severe/critical disease at admission (aOR, 1.05; 95%CI, 0.94-1.18); but is associated with a 24% increase in superinfection in all patients (aOR, 1.24; 95% CI, 1.12-1.37) and a 23% increase in superinfection in patients of O2 for several/critical disease at admission (aOR, 1.23; 95% CI, 1.02-1.47). Moreover, early dexamethasone is associated with a 42% increase in likelihood of delayed clearance of SARS-CoV-2 virus (adjusted hazard ratio, 1.42; 95% CI, 1.01-1.98). CONCLUSION: An early start of dexamethasone (within 7 days after the onset of symptoms) could be harmful to hospitalized patients with COVID-19.

Effects of intramolecular hydrogen bonding on the excited state dynamics of phenol chromophores.

The theoretical prediction and experimental confirmation of the 1πσ* excited state of phenol which is repulsive along the O-H bond has a large impact on the interpretation of phenol and tyrosine photochemistry. In this work, we demonstrate that this excited state changes significantly if the OH functional group is involved in the formation of an intramolecular hydrogen bond in the ground state. We investigate the excited state dynamics of 2-, 3-, and 4-hydroxyacetophenone (HAP) separately in a molecular beam at 193 nm using multimass ion imaging techniques. H atom elimination from the repulsive excited state and Norrish type I reactions are the major dissociation channels of 3-HAP and 4-HAP which do not have intramolecular hydrogen bonding. However, the H atom elimination channel is completely quenched for 2-HAP which shows intramolecular hydrogen bonding. In addition, the ground state and the excited state potential energy surfaces (PESs) of HAP, 2-hydroxybenzoyl fluoride, 2-hydroxybenzoyl chloride, and 2-hydroxybenzamide are investigated using ab initio calculations. The results also show that the excited state potential along the O-H bond distance of the hydroxyl group changes significantly for molecules with intramolecular hydrogen bonding. The changes include: (a) the repulsive potential energy surface becomes an attractive potential near the ground state equilibrium geometry, (b) the conical intersection between the first and the second excited states along the O-H bond moves to a much higher energy level, and (c) the conical intersection between the repulsive excited state and the ground state along the O-H bond distance disappears. The results suggest that the interpretation of the photochemistry for molecules with a phenol chromophore must take these effects into consideration.

Theoretical analysis on the kinetic isotope effects of bimolecular nucleophilic substitution (S(N)2) reactions and their temperature dependence.

Factors affecting the kinetic isotope effects (KIEs) of the gas-phase S(N)2 reactions and their temperature dependence have been analyzed using the ion-molecule collision theory and the transition state theory (TST). The quantum-mechanical tunneling effects were also considered using the canonical variational theory with small curvature tunneling (CVT/SCT). We have benchmarked a few ab initio and density functional theory (DFT) methods for their performance in predicting the deuterium KIEs against eleven experimental values. The results showed that the MP2/aug-cc-pVDZ method gave the most accurate prediction overall. The slight inverse deuterium KIEs usually observed for the gas-phase S(N)2 reactions at room temperature were due to the balance of the normal rotational contribution and the significant inverse vibrational contribution. Since the vibrational contribution is a sensitive function of temperature while the rotation contribution is temperature independent, the KIEs are thus also temperature dependent. For S(N)2 reactions with appreciable barrier heights, the tunneling effects were predicted to contribute significantly both to the rate constants and to the carbon-13, and carbon-14 KIEs, which suggested important carbon atom tunneling at and below room temperature.