MRI-negative myelitis associated with MOG-IgG antibody: A case report and literature reviews

According to few case reports, myelin oligodendrocyte glycoprotein-associated disease (MOGAD) could present as myelitis subtype with normal spine MRI, though it is rare. Herein, we report a case of clinically myelitis but MRI was normal, with strongly positive anti-MOG-IgG antibody in the sera. The patient showed a rapid improvement following a high dose methylprednisolone treatment.

Factors associated with functional disability in patients with acute stroke excluded from alteplase administration due to minor non-disabling neurological deficits

Background

Although the PRISMS study did not demonstrate the benefit of intravenous alteplase administration in patients with mild stroke within 3 h, about 30% of patients presenting with mild symptoms showed unfavorable functional outcomes. We investigated the factors predictive of functional disability at 90 days in patients who were excluded from alteplase administration due to the National Institutes of Health Stroke Scale (NIHSS) scores of 0-5 and a score between 0 and 2 for each NIHSS score item.

Methods

All patients were diagnosed with acute ischemic stroke or transient ischemic attack within 4.5 h of admission to a tertiary hospital and did not receive alteplase due to a minor stroke between January 2013 and December 2020. Radiological data and clinical information were collected, including baseline and discharge NIHSS scores and modified Rankin Scale (mRS) scores at 90 days. Early neurological deterioration (END) was defined as an increase of two or more NIHSS scores. We defined moderate motor weakness as a NIHSS limb motor score of more than 3 and defined a favorable outcome as a mRS score at 90 days that was 0 or 1.

Results

During the investigation period, 400 patients did not receive alteplase. END occurred significantly more frequently in patients with large artery disease (LAD) than in those with other TOAST classifications. In the multivariate regression analysis, NIHSS per 1-point increase, presenting as moderate motor weakness, and LAD were independent predictors of poor functional outcome (OR, 1.811 NIHSS per 1-point increase; 95% confidence interval [CI], 1.503-2.182; P < 0.0001; OR, 2.173 moderate motor weakness; 95% CI 1.028-4.595; P = 0.042; OR, 2.033 LAD; 95% CI 1.099-3.762; P = 0.024, respectively).

Conclusion

Moderate motor weakness presentation and LAD may be important factors associated with poor functional outcomes in patients with acute stroke excluded from alteplase administration due to mild symptoms.

The Impact of Discrepancy between Measured versus Stated Weight on Hemorrhagic Transformation and Clinical Outcomes after Intravenous Alteplase Thrombolysis

BACKGROUND

An accurate measurement of patient weight is important in determining the dosage for intravenous alteplase thrombolysis. In most emergency rooms, however, weight is not measured. We investigated the difference between stated and measured weight and its effect on hemorrhagic transformation and clinical outcomes.

METHODS

We enrolled 128 consecutive patients who had hyperacute stroke and were treated by alteplase. Alteplase dose was calculated using the weight provided by patient or guardian/caregiver, and the actual weight was measured after administration. Patients were classified into 2 groups: overused group (stated weight >measured weight) and underused group (measured weight ≥stated weight). The prevalence of hemorrhagic transformation on follow-up, determined by gradient-recalled echo MRI or non-enhanced CT, was compared between the 2 groups. The predictors for hemorrhage with progression, defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) by a value of 4 or more accompanied by hemorrhage, were determined using multivariable logistic regression analysis and included the overused or underused alteplase and baseline clinical and laboratory findings.

RESULTS

Sixty-six (51.6%) of 128 patients were in the underused group and 62 patients (48.4%) in the overused group. The median difference between the stated and measured weights was 1.5 (interquartile range 0.56-3.81) kg, with the largest difference being 25.6 kg. Although there were no significant difference in baseline clinical and laboratory findings between the 2 groups, the overused group showed a significantly higher prevalence of hemorrhagic transformation (p = 0.012) and hemorrhage with progression (p = 0.025). The multivariable logistic regression analysis demonstrated that overused alteplase (OR 7.26; 95% CI 1.24-42.45; p = 0.028), baseline glucose (>144 mg/dL; OR 5.03; 95% CI 1.00-25.26; p = 0.050), and initial NIHSS (OR 1.13 per 1-point NIHSS increase; 95% CI 1.00-1.27; p = 0.047) in model 1 that use alteplase overdose as a categorical variable and overused alteplase (OR 1.67 1-mg increase; 95% CI 1.05-2.66; p = 0.027) in model 2 that use an overused alteplase dose as numerical variable were significant predictors for hemorrhage with progression.

CONCLUSION

More alteplase usage than actual weight led to higher hemorrhagic transformation. As one of the predictors for clinical deterioration, it is important to administrate alteplase based on an accurately measured weight.

Cefepime-Induced Non-Convulsive Status Epilepticus in a Patient with Normal Renal Function

Cefepime-induced encephalopathy including nonconvulsive status epilepticus has been known to develop in the patients with renal impairment. However, we report a 74-year-old woman with normal renal function who developed stuporous mental status during cefepime administration. Electroencephalogram (EEG) revealed 2 Hz rhythmic sharp-and-waves continuously, which suggested nonconvulsive status epilepticus (NCSE). After cefepime discontinuation, clinical symptoms recovered gradually and EEG findings showed only background slowing without epileptiform discharges. Cefepime-induced NCSE could be developed even in the patients with normal renal function, when they are elderly. Therefore, clinicians should be aware of the possibility of cefepime-induced NCSE when prescribing cefepime even to the patients with normal renal function.

Randomized clinical trial of preoperative skin antisepsis with chlorhexidine gluconate or povidone–iodine

Background

Skin antiseptic agents are used to prevent surgical-site infection (SSI); few trials have reported the superiority of any specific agent in clean-contaminated abdominal surgery. This RCT was designed to compare the effectiveness of chlorhexidine gluconate and povidone–iodine.

Methods

Consecutive patients who underwent clean-contaminated upper gastrointestinal or hepatobiliary–pancreatic open surgery between 2011 and 2014 were assigned randomly to either chlorhexidine gluconate or povidone–iodine. The primary endpoint was the occurrence of SSI within 30 days of surgery. Secondary endpoints included causative organisms and risk factors for SSI.

Results

A total of 534 patients were randomized; 31 (5·8 per cent) developed an SSI. There was no difference in the overall SSI rate in the chlorhexidine gluconate and povidone–iodine groups: 15 of 267 (5·6 per cent) and 16 of 267 (6·0 per cent) respectively (P = 0·853). The most common causative organism was Enterococcus faecalis. In subgroup analysis, biliary–pancreatic surgery had a higher SSI rate (26 of 127, 20·5 per cent) than upper gastrointestinal (2 of 204, 1·0 per cent) and hepatic (3 of 203, 1·5 per cent) resection. Both age (60 years and over) and type of incision were associated with the risk of SSI.

Conclusion

No difference was detected between chlorhexidine gluconate and povidone–iodine antiseptics for prevention of SSI. Registration number: NCT01495117 (http://www.clinicaltrials.gov).

Vitamin D levels are not predictors of survival in a clinic population of patients with ALS

OBJECTIVE

This study aimed to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations, bone mineral density (BMD), and the parameters of bone metabolism in amyotrophic lateral sclerosis (ALS) patients, and their correlation with survival.

METHODS

We retrospectively analysed data of 100 ALS patients who consecutively visited a single referral ALS clinic between January and December 2011. Sex; age and site of symptom onset; and death were recorded. Serum 25(OH)D concentration was dichotomized as <10ng/ml and ≥10ng/ml.

RESULTS

There was absent relationship between serum 25(OH)D and concentration of bone turnover parameters or between 25(OH)D and BMD. According to the results of the Kaplan-Meier analysis with log-rank test, the survival rates of patients without (≥10ng/ml) and of those with severe vitamin D deficiency (< 10ng/ml) were not significantly different. Cox regression analysis showed that a poor prognosis was most correlated with older age at onset and bulbar onset after adjustment for all the clinical factors.

CONCLUSIONS

In conclusion, vitamin D levels were not correlated to other bone markers and survival in a clinic population of ALS patients.

Note: Near infrared interferometric silicon wafer metrology

In this investigation, two near infrared (NIR) interferometric techniques for silicon wafer metrology are described and verified with experimental results. Based on the transparent characteristic of NIR light to a silicon wafer, the fiber based spectrally resolved interferometry can measure the optical thickness of the wafer and stitching low coherence scanning interferometry can reconstruct entire surfaces of the wafer.

Control of mesenchymal stem cell phenotype and differentiation depending on cell adhesion mechanism

Control of cell-matrix adhesion has become an important issue in the regulation of stem cell function. In this study, a maltose-binding protein (MBP)-linked basic fibroblast growth factor (FGF2)-immobilised polystyrene surface (PS-MBP-FGF2) was applied as an artificial matrix to regulate integrin-mediated signalling. We sought to characterise human mesenchymal-stem cell (hMSC) behaviour in response to two different mechanisms of cell adhesion; (i) FGF2-heparan sulphate proteoglycan (HSPG)-mediated adhesion vs. (ii) fibronectin (FN)-integrin-mediated adhesion. Heparin inhibited hMSC adhesion to PS-MBP-FGF2 but not to FN-coated surface. The phosphorylation of focal adhesion kinase, cytoskeletal re-organisation, and cell proliferation were restricted in hMSCs adhering to PS-MBP-FGF2 compared to FN-coated surface. Expression of MSC markers, such as CD105, CD90 and CD166, decreased in hMSCs expanded on PS-MBP-FGF2 compared to expression in cells expanded on FN-coated surface. hMSCs that were expanded on FN-coated surface differentiated into osteogenic and adipogenic cells more readily than those that were expanded on PS-MBP-FGF2. Furthermore, we characterised the N-linked glycan structures of hMSCs depending on the cell adhesion mechanism using mass spectrometry (MS)-based quantitative techniques. MS analysis revealed that 2,3-sialylated glycans, a potential marker of stem cell function, were more abundant on hMSCs expanded on FN-coated surface than on those expanded on PS-MBP-FGF2. Thus, the differentiation potential of hMSCs is controlled by the type of adhesion substrate that might provide an idea for the design of biomaterials to control stem cell fate. Elucidation of the glycan structure on the cell membrane may help characterise hMSC function.

Sleep problems associated with behavioral and psychological symptoms as well as cognitive functions in Alzheimer's disease

BACKGROUND AND PURPOSE

It has been shown that sleep problems in Alzheimer's disease (AD) are associated with cognitive impairment and behavioral problems. In fact, most of studies have founded that daytime sleepiness is significantly correlated with cognitive decline in AD. However, a few studies have also shown that nighttime sleep problems are associated with cognitive function and behavioral symptoms in AD. Accordingly, the aim of this study was to evaluate the effects of nighttime sleep on cognition and behavioral and psychological symptoms of dementia (BPSD) in AD.

METHODS

The study population comprised 117 subjects: 63 AD patients and 54 age- and sex-matched non-demented elderly subjects. Detailed cognitive functions and behavioral symptoms were measured using the Seoul Neuropsychological Screening Battery (SNSB) and the Korean version of the Neuropsychiatric Inventory (NPI-K). Sleep characteristics were evaluated using the Korean version of the Pittsburgh Sleep Quality Index (PSQI-K). The correlations between PSQI-K and SNSB scores and between PSQI-K and NPI-K scores were analyzed.

RESULTS

In AD patients, sleep latency was found to be negatively correlated with praxis (p=0.041), Rey-Osterrieth Complex Figure Test (RCFT) immediate recall (p=0.041), and RCFT recognition (p=0.008) after controlling for age and education, while sleep duration and sleep efficiency were positively correlated with praxis (p=0.034 and p=0.025, respectively). Although no significant correlation was found between PSQI-K and NPI-K scores, sleep disturbance and total PSQI-K scores were found to be significantly associated with apathy/indifference in AD.

CONCLUSIONS

Sleep problems such as prolonged sleep duration, sleep latency, and poor sleep efficiency in AD patients were correlated with cognitive dysfunction, and especially frontal executive and visuospatial functions, and BPSD. These findings suggest that treatment of nighttime sleep problems might improve cognition and behavioral symptoms in AD patients.

Correlation of sleep disturbance and cognitive impairment in patients with Parkinson's disease

OBJECTIVE

Cognitive impairment is a common nonmotor symptom of Parkinson's disease (PD) and is associated with high mortality, caregiver distress, and nursing home placement. The risk factors for cognitive decline in PD patients include advanced age, longer disease duration, rapid eye movement sleep behavior disorder, hallucinations, excessive daytime sleepiness, and nontremor symptoms including bradykinesia, rigidity, postural instability, and gait disturbance. We conducted a cross-sectional study to determine which types of sleep disturbances are related to cognitive function in PD patients.

METHODS

A total of 71 PD patients (29 males, mean age 66.46 ± 8.87 years) were recruited. All patients underwent the Mini- Mental State Examination (MMSE) and the Korean Version of the Montreal Cognitive Assessments (MoCA-K) to assess global cognitive function. Sleep disorders were evaluated with the Stanford Sleepiness Scale, Epworth Sleepiness Scale, Insomnia Severity Index (ISI), Pittsburg Sleep Quality Index, and Parkinson's Disease Sleep Scale in Korea (PDSS).

RESULTS

The ISI was correlated with the MMSE, and total PDSS scores were correlated with the MMSE and the MoCA-K. In each item of the PDSS, nocturnal restlessness, vivid dreams, hallucinations, and nocturnal motor symptoms were positively correlated with the MMSE, and nocturnal restlessness and vivid dreams were significantly related to the MoCA-K. Vivid dreams and nocturnal restlessness are considered the most powerful correlation factors with global cognitive function, because they commonly had significant correlation to cognition assessed with both the MMSE and the MoCA-K.

CONCLUSIONS

We found a correlation between global cognitive function and sleep disturbances, including vivid dreams and nocturnal restlessness, in PD patients.

Spin-induced band modifications of graphene through intercalation of magnetic iron atoms

Intercalation of magnetic iron atoms through graphene formed on the SiC(0001) surface is found to induce significant changes in the electronic properties of graphene due mainly to the Fe-induced asymmetries in charge as well as spin distribution. From our synchrotron-based photoelectron spectroscopy data together with ab initio calculations, we observe that the Fe-induced charge asymmetry results in the formation of a quasi-free-standing bilayer graphene while the spin asymmetry drives multiple spin-split bands. We find that Fe adatoms are best intercalated upon annealing at 600 °C, exhibiting split linear π-bands, characteristic of a bilayer graphene, but much diffused. Subsequent changes in the C 1s, Si 2p, and Fe 3p core levels are consistently described in terms of Fe-intercalation. Our calculations together with a spin-dependent tight binding model ascribe the diffuse nature of the π-bands to the multiple spin-split bands originated from the spin-injected carbon atoms residing only in the lower graphene layer.

Arterial stiffness and functional outcome in acute ischemic stroke

OBJECTIVE

Arterial stiffness is a common change associated with aging and can be evaluated by measuring pulse wave velocity (PWV) between sites in the arterial tree, with the stiffer artery having the higher PWV. Arterial stiffness is associated with the risk of stroke in the general population and of fatal stroke in hypertensive patients. This study is to clarify whether PWV value predicts functional outcome of acute ischemic stroke.

METHODS

ONE HUNDRED PATIENTS WERE ENROLLED WITH A DIAGNOSIS OF ACUTE ISCHEMIC STROKE AND CATEGORIZED INTO TWO GROUPS: large-artery atherosclerosis (LAAS) or small vessel disease (SVD) subtype of Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Each group was divided into two sub-groups based on the functional outcome of acute ischemic stroke, indicated by modified Rankin Scale (mRS) at discharge. Poor functional outcome group was defined as a mRS ≥ 3 at discharge. Student's t-test or Mann-Whitney U-test were used to compare maximal brachial-ankle PWV (baPWV) values.

RESULTS

Twenty-four patients whose state was inadequate to assess baPWV or mRS were excluded. There were 38 patients with good functional outcome (mRS < 3) and 38 patients with poor functional outcome (mRS ≥ 3). The baPWV values were significantly higher in patients with poor outcome (2,070.05 ± 518.37 cm/s) compared with those with good outcome (1,838.63 ± 436.65) (p = 0.039). In patients with SVD subtype, there was a significant difference of baPWV values between groups (2,163.18 ± 412.71 vs. 1,789.80 ± 421.91, p = 0.022), while there was no significant difference of baPWV among patients with LAAS subtype (2,071.76 ± 618.42 vs. 1,878.00 ± 365.35, p = 0.579).

CONCLUSIONS

Arterial stiffness indicated by baPWV is associated with the functional outcome of acute ischemic stroke. This finding suggests that measurement of baPWV predicts functional outcome in patients with stroke especially those whose TOAST classification was confirmed as SVD subtype.

Unusual congenital pulmonary anomaly with presumed left lung hypoplasia in a young dog

A seven-month-old, entire, male miniature schnauzer dog was referred with acute vomiting, inappetence and depression primarily as a result of a gastric foreign body (pine cones). During investigations, thoracic radiographs revealed increased volume of the right lung lobes, deviated cardiomediastinal structures and elevation of the heart from the sternum. Thoracic computed tomography revealed left cranial lung lobe hypoplasia and extension of the right cranial lung parenchyma across the midline to the left hemithorax. Branches of the right pulmonary vessels and bronchi also crossed the midline and extended to the left caudal lung lobe. These findings suggested that the right and left lungs were fused. In humans this finding is consistent with horseshoe lung, which is an uncommon congenital malformation. To the authors' knowledge, this case represents the first report of such a pulmonary anomaly in a dog.

Relation between left atrial enlargement and stroke subtypes in acute ischemic stroke patients

Objective

Increased atrial size is frequently seen in ischemic stroke patients in clinical practice. There is controversy about whether left atrial enlargement (LAE) should be regarded as a risk factor for cerebral infarction. We investigated the association between indexed left atrial volume (LAVI) and conventional stroke risk factors as well as stroke subtypes in acute ischemic stroke patients.

Methods

One hundred eighty two acute cerebral infarction patients were included in this study. Brain magnetic resonance imaging and transthoracic echocardiography were done for all patients within 30 days of diagnosis of acute cerebral infarction. Echocardiographic LAE was identified when LAVI was more than 27 mL/m². Stroke subtypes were classified by the Trial of Org 10171 in acute stroke treatment classification.

Results

There were significant differences between subjects with normal and increased LAVI in prevalence of stroke risk factors including atrial fibrillation (p = 0.001), hypertension (p = 0.000), valvular heart disease (p = 0.011) and previous stroke (p = 0.031). An increased LAVI was associated with cardioembolic subtype with an adjusted odds ratio was 6.749 (p = 0.002) compared with small vessel disease.

Conclusion

Increased LAVI was more prevalent in those who had cardiovascular risk factors, such as atrial fibrillation, hypertension, valvular heart disease and history of previous stroke. LAE influenced most patients in all subtypes of ischemic stroke but was most prevalent in the cardioembolic stroke subtype. Increased LAVI might be a risk factor of cerebral infarction, especially in patients with cardioembolic stroke subtype.

Association between VEGF and eNOS gene polymorphisms and lumbar disc degeneration in a young Korean population

Disturbances in blood flow to intervertebral discs (IVD) play an important role in IVD degeneration. Vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) are extremely important angiogenic factors for vasodilation and neovascularization. We investigated the relationship between single nucleotide polymorphisms (SNPs) of the VEGF and eNOS genes and genetic susceptibility to lumbar IVD degeneration in a young adult Korean population. Two hundred and forty-one participants (aged 18 to 30 years), with or without low back pain, were selected for the study. Magnetic resonance imaging was made of the lumbar spine in all participants. The patient group (N = 102) had low back pain clinically and lumbar IVD degeneration radiographically. The control group (N = 139) included subjects with and without low back pain; all were negative radiographically for lumbar IVD degeneration. Using PCR-RFLP analysis, we analyzed VEGF (-2578C>A, -1154G>A, -634G>C, and 936C>T) and eNOS (-786T>C, 4a4b and 894G>T) SNPs. We made combined analyses of the genes and performed haplotype analyses. There were no significant differences in the genotype distribution of polymorphisms of VEGF and eNOS genes among patients and controls. However, the frequency of VEGF -2578CA +AA/-634CC combined genotypes was significantly higher in patients when compared with controls [odds ratio (OR) = 21.00; 95% confidence interval (CI) = 2.590- 170.240]. The frequencies of the -2578A/-1154A/-634C/936C (OR = 3.831; 95%CI = 1.068-13.742), -2578A/-1154A/-634C (OR = 3.356; 95%CI = 1.198-9.400), and -2578A/-634C/936C (OR = 10.820; 95%CI = 2.811-41.656) haplotypes were also significantly higher in patients than in controls. We conclude that the combined genotype VEGF -2578CA+AA/-634CC is a possible risk factor for IVD degeneration and the VEGF -2578A/-1154A/-634C/936C haplotype may increase the risk for development of IVD degeneration. Furthermore, the VEGF -634C allele appears to be associated with susceptibility to IVD degeneration.

A Case of Action-Induced Clonus that Mimicked Action Tremors and was Associated with Cervical Schwannoma

Clonus is the rhythmic muscle contraction which usually occurs in patients with lesions involving descending motor pathways. Sometimes, rhythmic oscillation of action induced clonus could be confused to action tremor. We report a case of action induced clonus associated with cervical schwannoma which was misdiagnosed as essential tremor. The patient had spasticity in all limbs with exaggerated tendon reflexes, and passive stretch-induced clonus. Imaging and histological examinations revealed a schwannoma extending from C2 to C7. The lesion was partially removed by surgery. Even though essential tremor is a common disease, clinician have to do sufficient neurologic examination considering differential diagnosis.

Pregnenolone sulfate enhances spontaneous glutamate release by inducing presynaptic Ca2+-induced Ca2+ release

Pregnenolone sulfate (PS) acts as an excitatory neuromodulator and has a variety of neuropharmacological actions, such as memory enhancement and convulsant effects. In the present study, we investigated the effect of PS on glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) in acutely isolated dentate gyrus (DG) hilar neurons by use of a conventional whole-cell patch-clamp technique. PS significantly increased sEPSC frequency in a concentration-dependent manner without affecting the current amplitude, suggesting that PS acts presynaptically to increase the probability of spontaneous glutamate release. However, known molecular targets of PS, such as α7 nicotinic ACh, NMDA, σ1 receptors and voltage-dependent Ca(2+) channels, were not responsible for the PS-induced increase in sEPSC frequency. In contrast, the PS-induced increase in sEPSC frequency was completely occluded in a Ca(2+)-free external solution, and was significantly reduced by either the depletion of presynaptic Ca(2+) stores or the blockade of ryanodine receptors, suggesting that PS elicits Ca(2+)-induced Ca(2+) release (CICR) within glutamatergic nerve terminals. In addition, the PS-induced increase in sEPSC frequency was completely occluded by transient receptor potential (TRP) channel blockers. These data suggest that PS increases spontaneous glutamate release onto acutely isolated hilar neurons via presynaptic CICR, which was triggered by the influx of Ca(2+) through presynaptic TRP channels. The PS-induced modulation of excitatory transmission onto hilar neurons could have a broad impact on the excitability of hilar neurons and affect the pathophysiological functions mediated by the hippocampus.

Chorea in the both lower limbs associated with nonketotic hyperglycemia

Hemichorea-hemiballism (HC-HB) is a complication of non-ketotic hyperglycemia (NKH); in NKH patients, the frequency of occurrence of HC-HB is greater than that of bilateral chorea. We report the case of a hyperglycemic patient who showed chorea in both the lower limbs. Magnetic resonance imaging (MRI) of the brain revealed high signal intensity on T1-weighted images of the bilateral dorsolateral putamen. The abnormal involuntary movements disappeared after oral administration of haloperidol. Our case report that chorea associated with NKH is correlated with the topography of the basal ganglia.

Novel compound heterozygous mutations in the pantothenate kinase 2 gene in a korean patient with atypical pantothenate kinase associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal recessive disorder that is characterized by mutations in the pantothenate kinase 2 gene (PANK2) and typical magnetic resonance imaging findings. We report a case of atypical PKAN presenting with generalized dystonia. Our patient had compound heterozygous mutations in the PANK2 gene, including mutation in exon 3 (p.D268G) and exon 4 (p.R330P). To our knowledge, this patient is the first to have the p.R330P mutation and the second to have the p.D268G mutation.

Extension of the Helmholtz-Smoluchowski velocity to the hydrophobic microchannels with velocity slip

Electrokinetic flows through hydrophobic microchannels experience velocity slip at the microchannel wall, which affects volumetric flow rate and solute retention time. The usual method of predicting the volumetric flow rate and velocity profile for hydrophobic microchannels is to solve the Navier-Stokes equation and the Poisson-Boltzmann equation for the electric potential with the boundary condition of velocity slip expressed by the Navier slip coefficient, which is computationally demanding and defies analytic solutions. In the present investigation, we have devised a simple method of predicting the velocity profiles and volumetric flow rates of electrokinetic flows by extending the concept of the Helmholtz-Smoluchowski velocity to microchannels with Navier slip. The extended Helmholtz-Smoluchowski velocity is simple to use and yields accurate results as compared to the exact solutions. Employing the extended Helmholtz-Smoluchowski velocity, the analytical expressions for volumetric flow rate and velocity profile for electrokinetic flows through rectangular microchannels with Navier slip have been obtained at high values of zeta potential. The range of validity of the extended Helmholtz-Smoluchowski velocity is also investigated.

Recursive estimation of transient inhomogeneous zeta potential in microchannel turns using velocity measurements

In the various biomedical microfluidic devices the target biomolecules are delivered by activating electroosmotic flows. The zeta potential of a microchannel wall, which determines the strength of the electroosmotic flow, is apt to change due to the adhesion of biomolecules such as DNA or protein especially around the microchannel turns. The resulting transient inhomogeneous profile of zeta potential alters flow pattern, volumetric flow rate and the band broading of solutes. In the present work, we have developed a method for the recursive estimation of transient inhomogeneous zeta potential in microchannel turns using velocity measurements. For the real time implementation of the present method, a compact and accurate reduced-order model is derived using the Karhunen-Loève Galerkin method and the Helmholtz-Smoluchowski slip velocity. The present scheme of recursive estimation is an important prerequisite to the real time control of microfluidic devices.

Effect of viscoelasticity on the flow pattern and the volumetric flow rate in electroosmotic flows through a microchannel

Many lab-on-a-chip based microsystems process biofluids such as blood and DNA solutions. These fluids are viscoelastic and show extraordinary flow behaviors, not existing in Newtonian fluids. Adopting appropriate constitutive equations these exotic flow behaviors can be modeled and predicted reasonably using various numerical methods. In the present paper, we investigate viscoelastic electroosmotic flows through a rectangular straight microchannel with and without pressure gradient. It is shown that the volumetric flow rates of viscoelastic fluids are significantly different from those of Newtonian fluids under the same external electric field and pressure gradient. Moreover, when pressure gradient is imposed on the microchannel there appear appreciable secondary flows in the viscoelastic fluids, which is never possible for Newtonian laminar flows through straight microchannels. The retarded or enhanced volumetric flow rates and secondary flows affect dispersion of solutes in the microchannel nontrivially.

ACE I/D polymorphism in Korean patients with ischemic stroke and silent brain infarction

OBJECTIVES

Angiotensin-converting enzyme (ACE) polymorphism may play a role in stroke and silent brain infarction (SBI) susceptibility, but the results among the populations studied to date have not been consistent. Thus, we investigated the association between ACE genotypes and ischemic stroke and SBI in Korean patients.

SUBJECTS AND METHODS

DNA samples from 237 stroke patients, 264 SBI patients and 234 age-matched controls were amplified using polymerase chain reaction to detect the ACE ins/del (I/D) polymorphism. Genotype was determined by the presence of a 490-bp band (I allele) or a 190-bp band (D allele) in agarose gel electrophoresis.

RESULTS

Odds ratios of the I/D and D/D genotypes and the overall (I/D + D/D) for the I/I genotype were significantly different between stroke patients and normal controls. However, there was no significant difference between patients with SBI and controls.

CONCLUSIONS

This study is the first report of a significant association between ACE polymorphism and ischemic stroke in the Asian population. Although no consistent associations have been found between ACE polymorphism and stroke in the populations studied to date, the ACE polymorphism may be a genetic determinant of ischemic stroke, at least in Korean patients.

Comparison of the Nernst–Planck model and the Poisson–Boltzmann model for electroosmotic flows in microchannels

In the analysis of electroosmotic flows, the internal electric potential is usually modeled by the Poisson-Boltzmann equation. The Poisson-Boltzmann equation is derived from the assumption of thermodynamic equilibrium where the ionic distributions are not affected by fluid flows. Although this is a reasonable assumption for steady electroosmotic flows through straight microchannels, there are some important cases where convective transport of ions has nontrivial effects. In these cases, it is necessary to adopt the Nernst-Planck equation instead of the Poisson-Boltzmann equation to model the internal electric field. In the present work, the predictions of the Nernst-Planck equation are compared with those of the Poisson-Boltzmann equation for electroosmotic flows in various microchannels where the convective transport of ions is not negligible.

Helmholtz-Smoluchowski velocity for viscoelastic electroosmotic flows

Many biofluids such as blood and DNA solutions are viscoelastic and exhibit extraordinary flow behaviors, not existing in Newtonian fluids. Adopting appropriate constitutive equations these exotic flow behaviors can be modeled and predicted reasonably using various numerical methods. However, the governing equations for viscoelastic flows are not easily solvable, especially for electroosmotic flows where the streamwise velocity varies rapidly from zero at the wall to a nearly uniform velocity at the outside of the very thin electric double layer. In the present investigation, we have devised a simple method to find the volumetric flow rate of viscoelastic electroosmotic flows through microchannels. It is based on the concept of the Helmholtz-Smoluchowski velocity which is widely adopted in the electroosmotic flows of Newtonian fluids. It is shown that the Helmholtz-Smoluchowski velocity for viscoelastic fluids can be found by solving a simple cubic algebraic equation. The volumetric flow rate obtained using this Helmholtz-Smoluchowski velocity is found to be almost the same as that obtained by solving the governing partial differential equations for various viscoelastic fluids.

Efficacy and tolerability of estradiol 1mg and drospirenone 2mg in postmenopausal korean women: A double-blind, randomized, placebo-controlled, multicenter study

OBJECTIVES

The aim of this study was to demonstrate that the therapeutic efficacy of an estradiol 1mg/drospirenone 2mg (E2/DRSP) preparation is superior to a placebo in postmenopausal Korean women with hot flushes and other climacteric symptoms, and to demonstrate that this treatment is both safe and tolerable.

METHODS

This was a double-blind, randomized, placebo-controlled, multicenter study over four 28-day treatment cycles. A total of 158 subjects were screened and 90 women were randomized into two treatment groups (E2/DRSP group, n=45; placebo group, n=45). The primary efficacy parameter was the individual relative change of hot flushes. The secondary efficacy parameters such as other climacteric, urogenital symptoms and vaginal bleeding patterns were also evaluated, and the occurrence of any adverse events was noted. In addition, physical, gynecological examinations and laboratory analyses were performed at the beginning and end of the study.

RESULTS

The mean number of hot flushes per week during treatment weeks 3-16 decreased by 48.1% during treatment with placebo, and by 84.4% during treatment with E2/DRSP (p<0.001). The E2/DRSP combination also reduced the incidence and intensity of menopausal symptoms in postmenopausal women. Most of adverse events was mild or moderate degree of intensity. None of the parameters measured in the study, including laboratory analyses, physical and gynecological examinations, vital signs, and weight, led to any concerns of safety.

CONCLUSIONS

The E2 1mg/DRSP 2mg combination tested in the study was efficacious and safe in the treatment of hot flushes and other climacteric symptoms in postmenopausal Korean women.

Estimation of zeta potential of electroosmotic flow in a microchannel using a reduced-order model

A reduced-order model is derived for electroosmotic flow in a microchannel of nonuniform cross section using the Karhunen-Loève Galerkin (KLG) procedure. The resulting reduced-order model is shown to predict electroosmotic flows accurately with minimal consumption of computer time for a wide range of zeta potential zeta and dielectric constant epsilon. Using the reduced-order model, a practical method is devised to estimate zeta from the velocity measurements of the electroosmotic flow in the microchannel. The proposed method is found to estimate zeta with reasonable accuracy even with noisy velocity measurements.

Simultaneous estimation of zeta potential and slip coefficient in hydrophobic microchannels

Electroosmotic flows through hydrophobic microchannels experience velocity slip at the channel wall, which increases the volumetric flow rate at a given electric potential gradient. The conventional method of zeta potential estimation using the volumetric flow rate may yield quite inaccurate zeta potential unless the velocity slip is appropriately taken care of. In the present investigation we develop a method for simultaneous estimation of zeta potential and velocity slip coefficient in the electroosmotic flow through a hydrophobic microchannel using velocity measurements. The relevant inverse problem is solved through the minimization of a performance function utilizing a conjugate gradient method. The present method is found to estimate the zeta potential and slip coefficient accurately even with noisy velocity measurements.

Eikenella corrodens cervical spinal epidural abscess induced by a fish bone

Cervical spinal epidural abscess, caused by fish bone injury and a secondary infection by Eikenella corrodens which is part of the normal flora, has not been reported. A 72-yr-old man came to the hospital with pain in his posterior neck and both shoulders for 2 months. He also was experiencing weakness on his right side for 3 days. A fish bone had been stuck in his throat for about 2 months. Neurological examination revealed right hemiparesis, hypesthesia on the left extremities and neck stiffness. Laboratory findings showed an elevated ESR/CRP and leukocytosis, and magnetic resonance imaging revealed a retropharyngeal abscess and cervical myelitis. The patient was treated with emergency surgical decompression and antibiotics. A fish bone was removed from the C3-C4 intervertebral disc space. In the culture of chocolate blood agar and 5% sheep blood agar plate, E. corrodens was detected as a causative organism.

Estimation of the zeta potential and the dielectric constant using velocity measurements in the electroosmotic flows

In this paper we develop a method for the determination of the zeta potential zeta and the dielectric constant epsilon by exploiting velocity measurements of the electroosmotic flow in microchannels. The inverse problem is solved through the minimization of a performance function utilizing the conjugate gradient method. The present method is found to estimate zeta and epsilon with reasonable accuracy even with noisy velocity measurements.

Supplementation of whole persimmon leaf improves lipid profiles and suppresses body weight gain in rats fed high-fat diet

The objective of this study was to investigate the hypolipidemic effects of powdered whole persimmon leaf supplement in rats fed high-fat diet. Three groups of male Sprague-Dawley rats during 6 weeks were fed different diet: normal control (NC), high-fat (HF), and high-fat supplemented with powdered whole persimmon leaf (PL; 5%, wt/wt) groups. Body weight and relative weight of interscapular brown adipose tissue were significantly lower in the PL group than in the HF group, while plasma leptin concentration was higher. The supplementation of persimmon leaf significantly lowered the plasma total cholesterol and triglyceride concentrations, whereas elevated the ratio of HDL-C/total-C and improved the atherogenic index. Persimmon leaf supplementation led the hepatic cholesterol and triglyceride values to similar levels to the NC group. Accumulation of hepatic lipid droplets and the epididymal white adipocyte size of PL group were diminished comparing to the HF group. Hepatic HMG-CoA and ACAT activities were significantly higher in the PL group than in other groups. Contents of fecal triglyceride, cholesterol and acidic sterol were significantly higher in the PL group than in the HF group. Accordingly, we suggest that supplementation of the powdered whole persimmon leaf improves plasma and hepatic lipid levels profile partly via the increased fecal lipids in high-fat fed rats. These beneficial effects may be due to the properties of its phenolic compounds (1.15 g/100g) and high fiber (63.48 g/100g) content in the powdered persimmon leaf.

Mullerian adenosarcoma with sarcomatous overgrowth of the cervix presenting as cervical polyp: a case report and review of the literature

An aggressive variant of adenosarcoma, mullerian adenosarcoma with sarcomatous overgrowth (MASO) in the cervix is extremely rare. This variant contains obvious, high-grade sarcoma in addition to a low-grade form. In this report, we describe a case of MASO of the uterine cervix and review the clinical and pathological features of these tumors. The patient was a 37-year-old woman with a cervical polypoid mass, which was morphologically considered as a benign endocervical polyp. Microscopically, polypoid cervical mass showed diffuse and dense malignant spindle cell proliferation around the benign endocervical glands and also an area of markedly anaplastic and pleomorphic spindle cell proliferation, so called, sarcomatous overgrowth. Total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymph node dissection were performed. The patient has been followed-up and neither chemotherapy nor other adjuvant therapies have been administered. At present, she has been clinically free of disease for 9 months since she received surgery. It is extremely rare that MASO of the uterine cervix is presented in premenopausal woman. Gynecologists and pathologists should be aware of the difficulties associated with a delay in the diagnosis of MASO when the tumor is present as a benign looking cervical polyp.

Comparison of Magnetoencephalographic Spikes with and without Concurrent Electroencephalographic Spikes in Extratemporal Epilepsy

Interictal spikes in patients with epilepsy may be detected by either electroencephalography (EEG) (E-spikes) or magnetoencephalography (MEG) (M-spikes), or both MEG and EEG (E/M-spikes). Localization and amplitude were compared between E/M-spikes and M-spikes in 7 adult patients with extratemporal epilepsy to evaluate the clinical significance of MEG spikes. MEG and EEG were simultaneously measured using a helmet-shaped MEG system with planar-type gradiometers and scalp electrodes of the international 10-20 system. Sources of E/M-spikes and M-spikes were estimated by an equivalent current dipole (ECD) model for MEG at peak latency. Each subject showed 9 to 20 (mean 13.4) E/M-spikes and 9 to 31 (mean 16.3) M-spikes. No subjects showed significant differences in the ECD locations between E/M- and M-spikes. ECD moments of the E/M-spikes were significantly larger in 2 patients and not significantly different in the other 5 patients. The similar localizations of E/M-spikes and M-spikes suggest that combination of MEG and EEG is useful to detect more interictal spikes in patients with extratemporal epilepsy. The smaller tendency of ECD amplitude of the M-spikes than E/M-spikes suggests that scalp EEG may overlook small tangential spikes due to background brain noise. Localization value of M-spikes is clinically equivalent to that of E/M-spikes.

Korean experience with the OSTA risk index for osteoporosis: a validation study

The Osteoporosis Self-assessment Tool for Asians (OSTA) was developed to help physicians focus their efforts on patients at increased risk, and encourage appropriate use of bone mineral density (BMD) measurements. Previously, OSTA performed well in a sample of women from eight countries in Asia, and in a validation group of Japanese women. In this study, we evaluate the performance of OSTA using a sample of 1101 postmenopausal women from a clinic in Korea who had femoral neck BMD measurements by dual-energy X-ray absorptiometry (DXA). The OSTA had a high sensitivity (87%), and good specificity (67%) for identifying osteoporosis (BMD T-scores <or= -2.5); the corresponding values were 80% and 72% for identifying T-scores <or= -2.0. The prevalence of osteoporosis ranged from 2% among women classified as low risk (OSTA > -1) to 64% among those classified as high risk (OSTA < -4); these results were almost identical to those reported earlier for a sample of women from eight Asian countries. We conclude that the OSTA risk tool performed well in this sample of postmenopausal Korean women, similar to previous results in other Asian women. The OSTA tool is free and very easy to use; risk can be tabulated by age and weight, so that calculations are not necessary. Using OSTA could encourage patients and clinicians to actively assess osteoporosis, and measure BMD when appropriate, before fractures occur.

Vestibular diagnosis as prognostic indicator in sudden hearing loss with vertigo

The majority of episodes of sudden hearing loss are caused by inner ear disorders, often accompanied by vertigo. The patterns of hearing loss usually influence the prognosis. The purpose of this study was to analyze vestibular diagnoses in sudden hearing loss with vertigo, and to correlate them with the recovery of hearing loss. The clinical records of 125 patients with sudden hearing loss were reviewed. Various vestibular evaluations were performed in 36 patients with vertigo. The vertigo in these patients was classified as normal, unilateral hypofunction, directional preponderance, benign paroxysmal positional vertigo (BPPV), non-specific or irritative. The initial and final pure-tone audiograms of these patients were compared. The distribution of vestibular diagnoses was unilateral hypofunction in 30.6% of patients, BPPV in 25.7%, normal in 19.4%, non-specific in 11.1%, directional preponderance in 8.3% and irritative in 8.3%. The recovery of hearing in patients with vertigo was significantly worse than in those without vertigo. The recovery of hearing in patients with spinning vertigo did not differ from that of patients with non-spinning vertigo. The recovery of hearing was worst in the BPPV group, especially in the high frequency range, followed by the unilateral hypofunction group, who showed hearing thresholds between those in the BPPV group and those in the normal vestibular function test group. This study suggests that the diagnostic classification of vestibulopathy is a useful prognostic indicator of hearing recovery in sudden hearing loss with vertigo. We conclude that otolithic and semicircular canal involvement may cause poor hearing results, especially in the high frequency range.

Negative regulation of filamentous growth and flocculation by Lkh1, a fission yeast LAMMER kinase homolog

We have isolated a full-length cDNA clone that encodes for a Schizosaccharomyces pombe homolog of the dual-specificity protein kinase of the LAMMER family, lkh1 (lammer kinase homolog). The proposed Lkh1 protein contains 575 amino acids. The lkh1(+) null mutant is viable, but exhibits flocculation upon reaching stationary phase in liquid media and filamentous adhesion growth on solid media. Analysis of the flocculation activity of the lkh1(+) null mutant indicates that asexual aggregation of S. pombe cells into floccules is divalent cation-dependent and galactose-specific. We also demonstrate that the Saccharomyces cerevisiae LAMMER kinase homolog, Kns1, can substitute for the Lkh1 function in S. pombe.

Observation of a (6)(LambdaLambda)He double hypernucleus

A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.

Elevated gastrin secretion by in vivo gene electroporation in skeletal muscle

Whether or not in vivo gene transfer of gastrin gene into skeletal muscle by electroporation could modify gastrin secretion was examined. The expression plasmid vector, either pMEPrGaspA encoding the rat gastrin gene or pEGFP-N1 encoding the GFP reporter gene was injected into M. rectus abdominis of rats or M. biceps formis of mice. Subsequently, square electric pulses of direct current were applied six times at 25 V with a loading period of 100 msec per pulse. Clear foreign gene expression in the skeletal muscle was demonstrated by both GFP fluorescence and immunostaining of rat gastrin. Time course changes in plasma gastrin levels after transfection revealed that in rats, gastrin gene transfer significantly increased the plasma gastrin level for 4 weeks post-transfection (P<0.05), but the difference diminished at the end of the 10-week period. In mice, plasma gastrin level elevated similarly for 3 weeks, and pH of gastric contents decreased in the gastrin gene transfected group compared with the control counterpart (P<0.05). These findings suggest that localized in vivo gene transfer by electroporation allows skeletal muscle to become an artificial endocrine tissue for hormonal manipulation of animals.