Efficacy and safety of shunt surgery in patients with idiopathic normal-pressure hydrocephalus: can we predict shunt response by preoperative magnetic resonance imaging (MRI)?

AIM

The aim of this study was to identify preoperative magnetic resonance imaging (MRI) findings that can predict the shunt responsiveness in idiopathic normal-pressure hydrocephalus (iNPH) patients and to investigate postoperative outcome and complications.

MATERIALS AND METHODS

A total of 192 patients with iNPH who underwent shunt at our hospital between 2000 and 2021 were included to investigate complications. Of these, after exclusion, 127 (1-month postoperative follow-up) and 77 (1-year postoperative follow-up) patients were evaluated. The preoperative MRI features (the presence of tightness of the high-convexity subarachnoid space, Sylvian fissure enlargement, Evans' index, and callosal angle) of the shunt-response and nonresponse groups were compared, and a systematic review was conducted to evaluate whether preoperative MRI findings could predict shunt response.

RESULTS

Postoperative complications within one month after surgery were observed in 6.8% (13/192), and the most common complication was hemorrhage. Changes in corpus callosum were observed in 4.2% (8/192). The shunt-response rates were 83.5% (106/127) in the 1-month follow-up group and 70.1% (54/77) in 1-year follow-up group. In the logistic regression analysis, only Evans' index measuring >0.4 had a significant negative relationship with shunt response at 1-month follow-up; however, no significant relationship was observed at 1-year follow-up. According to our systematic review, it is still controversial whether preoperative MRI findings could predict shunt response.

CONCLUSION

Evans' index measure of >0.4 had a significant relationship with the shunt response in the 1-month follow-up group. In systematic reviews, there is ongoing debate about whether preoperative MRI findings can accurately predict responses to shunt surgery. Postoperative corpus callosal change was observed in 4.2% of iNPH patients.

Improved diagnostic performance of susceptibility-weighted imaging with compressed sensing-sensitivity encoding and neuromelanin-sensitive MRI for Parkinson's disease and atypical Parkinsonism

AIM

To verify the diagnostic performance of the loss of nigrosome-1 on susceptibility-weighted imaging (SWI) with compressed sensing-sensitivity encoding (CS-SENSE) and neuromelanin on neuromelanin-sensitive (NM) magnetic resonance imaging (MRI) for the diagnosis of Parkinson's disease (PD) and atypical Parkinsonism.

MATERIALS AND METHODS

A total of 195 patients who underwent MRI between October 2019 and February 2020, including SWI, with or without CS-SENSE, and NM-MRI, were reviewed retrospectively. Two neuroradiologists assessed the loss of nigrosome-1 on SWI and neuromelanin on the NM-MRI. The result of N-3-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropane positron-emission tomography (PET) was set as the reference standard.

RESULTS

When CS-SENSE was applied for nigrosome-1 imaging on SWI, the non-diagnostic scan rate was lowered significantly from 19.3% (17/88) to 5.6% (6/107; p=0.004). Diagnosis of PD and atypical Parkinsonism based on the loss of nigrosome-1 on SWI and based on NM-MRI showed good diagnostic value (area under the curve [AUC] 0.821, 95% confidence interval [CI] = 0.755-0.875: AUC 0.832, 95% CI = 0.771-0.882, respectively) with a substantial inter-reader agreement (κ = 0.791 and 0.681, respectively). Combined SWI and neuromelanin had a similar discriminatory ability (AUC 0.830, 95% CI = 0.770-0.880). Similarly, the diagnosis of PD was excellent.

CONCLUSIONS

CS-SENSE may add value to the diagnostic capability of nigrosome-1 on SWI to reduce the nondiagnostic scan rates. Furthermore, loss of nigrosome-1 on SWI or volume loss of neuromelanin on NM-MRI may be helpful for diagnosing PD.

Detection rate of MR myelography without intrathecal gadolinium in patients with newly diagnosed spontaneous intracranial hypotension

AIM

To evaluate the detection rate of magnetic resonance (MR) myelography without intrathecal gadolinium for cerebrospinal fluid (CSF) leakage in patients with newly diagnosed spontaneous intracranial hypotension (SIH) and to validate a published scoring system for predicting CSF leakage.

MATERIALS AND METHODS

This retrospective, observational, single-institution study included patients with newly diagnosed SIH between March 2015 and April 2021. Patients were included if they (a) had newly diagnosed SIH and (b) underwent initial brain MR imaging and preprocedural MR myelography with two- and three-dimensional turbo spin-echo sequences. Patients who underwent spine surgery or procedures including epidural injection and acupuncture were excluded. The detection rate was defined as the proportion of patients with a true-positive MR myelography result among all patients with confirmed CSF leakage. The interobserver agreement for the MR myelography results between two radiologists was analysed using weighted kappa statistics.

RESULTS

A total of 136 patients (mean age, 48 years; 70 women) with suspected SIH were included. Of these patients, 120 (88%, 120/136) were confirmed to have CSF leakage. Of the patients with confirmed CSF leakage, 90 (75%, 90/120) had epidural fluid collection. The detection rate of MR myelography for CSF leakage was 88% (105/120). The interobserver agreement between the two readers for detecting CSF leakage (κ = 0.76) or epidural fluid collection (κ = 0.76) on MR myelography was high. Among 24 patients with normal brain MR imaging results, 16 had CSF leakage (67%, 16/24).

CONCLUSIONS

Non-invasive MR myelography without intrathecal gadolinium should be considered to detect CSF leakage in patients with suspected SIH.

Impact of COVID-19 on TB epidemiology in South Korea

SETTING: Five referral hospitals, South Korea.OBJECTIVE: To assess epidemiological changes in TB before and during the COVID-19 pandemic.DESIGN: This was a multicentre cohort study of 3,969 patients diagnosed with TB.RESULTS: We analysed 3,453 patients diagnosed with TB prior to the COVID-19 pandemic (January 2016-February 2020) and 516 during the pandemic (March-November 2020). During the pandemic, the number of patients visits declined by 15% from the previous 4-year average, and the number of patients diagnosed with TB decreased by 17%. Patients diagnosed during the pandemic were older than those diagnosed before the pandemic (mean age, 60.2 vs. 56.6 years, P < 0.001). The proportion of patients to have primary TB at a younger age (births after 1980) among those diagnosed with TB was significantly lower during the pandemic than before (17.8% in 2020 vs. 23.5% in 2016, 24.0% in 2017, 22.5% in 2018, 23.5% in 2019; P = 0.005).CONCLUSIONS: The COVID-19 pandemic resulted in a reduction in the number of visits to respiratory departments, leading to fewer patients being diagnosed with TB. However, our results suggest that universal personal preventive measures help to suppress TB transmission in regions with intermediate TB burden.

Impact of formulary interventions on the minimum inhibitory concentration of methicillin-resistant Staphylococcus aureus to mupirocin, chlorhexidine, and octenidine in a Singapore tertiary institution

Methicillin-resistant Staphylococcus aureus (MRSA) decolonization is an effective measure to prevent clinical infection but resistance is a concern. We aim to evaluate the impact of mupirocin (MUP) ointment formulary removal, plateauing use of chlorhexidine gluconate (CHG), and hospital-wide introduction of octenidine (OCT)-based products on the minimum inhibitory concentration (MIC) of MRSA to MUP, CHG, and OCT in our hospital. A prevalence study was conducted at three time points (TP) on consecutive MRSA screening isolates to evaluate for their MICs to MUP, CHG, and OCT using broth microdilution sensititre plates and detection of the ileS-2 gene encoding high-level MUP resistance in 2013 (pre-intervention TP1; n = 160), 2016 (early post-intervention TP2; n = 99) and 2017 (late post-intervention TP3; n = 76). Statistical analyses were performed using Chi square test with reference from TP1. There was a significant improvement in MUP susceptibility (MIC < 4 mcg/ml) from 71.9% (TP1) to 86.9% (TP2; p = 0.006) to 88.2% (TP3; p = 0.007). The prevalence of MUP high-level resistance (MIC > 256 mcg/ml) reduced from 25.0% (TP1) to 12.1% (TP2; p = 0.014) to 5.3% (TP3; p = 0.001). Likewise, the prevalence of isolates harboring the ileS-2 gene decreased from 28.1% (TP1) to 18.2% (TP2; p = 0.072) to 9.2% (TP3; p = 0.002). OCT MIC range remains stable at 0.5 to 1 mcg/ml across all three TPs. The proportion of isolates with reduced CHG susceptibility (MIC ≥ 4 mcg/ml) increased over the three TPs from 23.1 to 27.2% (p = 0.45) to 42.1% (p = 0.003). Active formulary regulations have an impact on the resistance profile of MRSA and can be used as a strategy to preserve the MRSA decolonization armamentarium.

Sex-specific association of urate and levodopa-induced dyskinesia in Parkinson's disease

BACKGROUND AND PURPOSE

As a major antioxidant, uric acid (UA) is known to be associated with the clinical progression of Parkinson's disease (PD). This study investigated whether baseline UA levels are associated with the risk for levodopa-induced dyskinesia (LID) in PD in a sex-dependent manner.

METHODS

In all, 152 patients with de novo PD (78 males and 74 females) who were followed up for >2 years were enrolled. The effect of baseline serum UA levels on LID-free survival was assessed by Cox regression, separately for sex, whilst being adjusted for potential confounding factors. The optimal UA level cut-off value to determine the high-risk group for LID was set using Contal and O'Quigley's method.

RESULTS

Levodopa-induced dyskinesia developed in 23 (29.5%) male patients and 30 (40.5%) female patients. Cox regression showed a significant interaction between UA level and sex. Higher UA levels were associated with a higher risk for LID in male PD patients (hazard ratio 1.380; 95% confidence interval 1.038-1.835; P = 0.027), although this relationship was not observed in female PD patients. The optimal UA level cut-off for LID in male PD was 7.2 mg/dl, and the high UA group had a 5.7-fold higher risk of developing LID than the low UA group.

CONCLUSIONS

Contrary to a presumptive beneficial role of UA, the present study demonstrated that higher UA levels are associated with increased risk of LID occurrence in male patients with PD, suggesting a sex-dependent role of UA in LID.

Cognitive anosognosia is associated with frontal dysfunction and lower depression in Parkinson's disease

BACKGROUND AND PURPOSE

Anosognosia refers to a deficit of self-awareness or impaired insight for cognitive and behavioral problems. Cognitive anosognosia was explored in de novo patients with Parkinson's disease (PD) and its relationship to cognitive function and neuropsychiatric symptoms was investigated.

METHODS

The cross-sectional study enrolled 340 drug-naïve patients with PD. According to the presence of mild cognitive impairment (MCI) and subjective cognitive complaint, patients were classified as patients with cognitive anosognosia (PD-CA, n = 74), with normal cognitive recognition (PD-NR, n = 184) or with cognitive underestimation (PD-CU, n = 82). After controlling for covariates, cognitive performance and neuropsychiatric symptoms were compared between the PD groups.

RESULTS

Cognitive anosognosia was found in 21.8% of patients with de novo PD. The PD-CA group showed poorer performance in all cognitive domains except for attention. Amongst PD patients with MCI, those with cognitive anosognosia showed lower composite z-scores in the Stroop color reading test than those without. The Beck Depression Inventory score in the PD-NR group was lower than that in the PD-CU group and higher than that in the PD-CA group. The Cognitive Complaints Interview score mediated the association between cognitive anosognosia and Beck Depression Inventory score.

CONCLUSIONS

Cognitive anosognosia in PD was associated with greater frontal dysfunction and lower depression. Since cognitive anosognosia has a harmful impact on PD patients and their caregivers due to overestimation of their abilities in everyday life, early identification of cognitive anosognosia in PD is important in management and prognosis.

Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy

BACKGROUND AND PURPOSE

Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated.

METHODS

The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group.

RESULTS

Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction.

CONCLUSIONS

The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.

Clinical relevance of amnestic versus non-amnestic mild cognitive impairment subtyping in Parkinson's disease

BACKGROUND AND PURPOSE

To clarify whether subtyping of amnestic and non-amnestic mild cognitive impairment (MCI) is clinically relevant in Parkinson's disease (PD) by analyzing patterns of neuroimaging and longitudinal cognitive changes.

METHODS

We performed comparative analyses of cortical thickness, hippocampal volume, white matter integrity and resting-state functional connectivity between the patients with de-novo PD with amnestic MCI (PD-aMCI) (n = 50) and non-amnestic MCI (PD-naMCI) (n = 50) subtypes. Additionally, we assessed the longitudinal rate of cognitive decline in each cognitive domain over time and the rate of dementia conversion in patients with de-novo PD-aMCI (n = 125) and PD-naMCI (n = 61).

RESULTS

The demographic data showed that scores in memory domains were lower in the PD-aMCI group compared with the PD-naMCI group. There were no significant differences in cortical thickness, hippocampal volume and white matter integrity between the two groups, although the PD-aMCI group exhibited more cortical thinning and hippocampal atrophy relative to the control group. The PD-aMCI group exhibited increased functional connectivity in the left posterior parietal region with the salience network relative to the PD-naMCI group. The longitudinal cognitive assessment demonstrated that patients with PD-aMCI exhibited a more rapid cognitive decline in frontal/executive function than those with PD-naMCI (P = 0.022). In addition, the PD-aMCI group had a higher risk of dementia conversion than the PD-naMCI group.

CONCLUSIONS

This study suggests that the designation of PD-MCI subtypes based on memory function would highlight the heterogeneity of functional correlates as well as the longitudinal cognitive prognosis.

Recurrent trichosporonosis with central nervous system involvement in an allogeneic hematopoietic stem cell transplant recipient

Trichosporon is an ubiquitous yeast that has emerged as an opportunistic pathogen in the immunocompromised host. We describe a case of invasive trichosporonosis in an allogeneic hematopoietic stem cell transplant (allo-HSCT) recipient while on caspofungin antifungal prophylaxis. She developed disseminated trichosporonosis in the pre-engraftment period and was successfully treated with voriconazole. She later developed 2 further episodes of invasive trichosporonosis involving the central nervous system. This case highlights the challenges of managing trichosporonosis in allo-HSCT recipients and suggests the need for lifelong therapy in some patients.

Cerebral Microbleeds in Patients with Dementia with Lewy Bodies and Parkinson Disease Dementia

BACKGROUND AND PURPOSE

The burden of amyloid β is greater in patients with dementia with Lewy bodies than in those with Parkinson disease dementia, and an increased amyloid β load is closely related to a higher incidence of cerebral microbleeds. Here, we investigated the prevalence and topography of cerebral microbleeds in patients with dementia with Lewy bodies and those with Parkinson disease dementia to examine whether cerebral microbleeds are more prevalent in patients with dementia with Lewy bodies than in those with Parkinson disease dementia.

MATERIALS AND METHODS

The study population consisted of 42 patients with dementia with Lewy bodies, 88 patients with Parkinson disease dementia, and 35 controls who underwent brain MR imaging with gradient recalled-echo. Cerebral microbleeds were classified as deep, lobar, or infratentorial.

RESULTS

The frequency of cerebral microbleeds was significantly greater in patients with dementia with Lewy bodies (45.2%) than in those with Parkinson disease dementia (26.1%) or in healthy controls (17.1%; P = .017). Lobar cerebral microbleeds were observed more frequently in the dementia with Lewy bodies group (40.5%) than in the Parkinson disease dementia (17%; P = .004) or healthy control (8.6%; P = .001) group, whereas the frequencies of deep and infratentorial cerebral microbleeds did not differ among the 3 groups. Logistic regression analyses revealed that, compared with the healthy control group, the dementia with Lewy bodies group was significantly associated with the presence of lobar cerebral microbleeds after adjusting for age, sex, nonlobar cerebral microbleeds, white matter hyperintensities, and other vascular risk factors (odds ratio, 4.39 [95% CI, 1.27-15.25]). However, compared with the healthy control group, the Parkinson disease dementia group was not significantly associated with lobar cerebral microbleeds.

CONCLUSIONS

This study showed that patients with dementia with Lewy bodies had a greater burden of cerebral microbleeds and exhibited a lobar predominance of cerebral microbleeds than did patients with Parkinson disease dementia.

Debate on MERS-CoV respiratory precautions: surgical mask or N95 respirators?

Since the emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in mid-2012, there has been controversy over the respiratory precaution recommendations in different guidelines from various international bodies. Our understanding of MERS-CoV is still evolving. Current recommendations on infection control practices are heavily influenced by the lessons learnt from severe acute respiratory syndrome. A debate on respiratory precautions for MERS-CoV was organised by Infection Control Association (Singapore) and the Society of Infectious Disease (Singapore). We herein discuss and present the evidence for surgical masks for the protection of healthcare workers from MERS-CoV.

Waveform analysis of tremor may help to differentiate Parkinson's disease from drug-induced parkinsonism

In this study, we analyzed the waveform characteristics of resting tremor by accelerometer recordings in patients with drug-induced parkinsonism (DIP) and Parkinson's disease (PD). We prospectively recruited 12 patients with tremulous PD and 12 patients with DIP presenting with resting tremor. Tremor was recorded from the more affected side and was recorded twice for a 60 s period in each patient. Peak frequency, amplitude and all harmonic peaks were obtained, and the asymmetry of the decay of the autocorrelation function, third momentum and time-reversal invariance were also computed using a mathematical algorithm. Among the parameters used in the waveform analysis, the harmonic ratio, time-reversal invariance and asymmetric decay of the autocorrelation function were different between PD and DIP at a statistically significant level (all p < 0.01). The total harmonic peak power and third momentum in the time series were not significantly different. The clinical characteristics of DIP patients may be similar to those of PD patients in some cases, which makes the clinical differentiation between DIP and PD challenging. Our study shows that the identification of parameters reflecting waveform asymmetry might be helpful in differentiating between DIP and PD.

Sensory characteristics and cross-cultural consumer acceptability of Bulgogi (Korean traditional barbecued beef)

Bulgogi (Korean traditional barbecued beef) is the most well-known Korean food to foreigners. There are, however, few studies on its sensory characteristics and consumer acceptability. This study was performed to identify the sensory attributes of Bulgogi samples prepared with different formulation and to compare the consumer acceptability in Korea and the United States. Bulgogi samples were prepared with varying levels of sugar and soy sauce with/without garlic or sesame oil. Descriptive analysis was conducted by 8 trained panelists. In consumer tests, 42 consumers in Seoul, Korea, 53 consumers in Davis (Calif., U.S.A.), and 39 consumers in St. Paul (Minn., U.S.A.) participated. Higher levels of sugar and soy sauce (SSS) significantly increased sweetness, saltiness, MSG taste, and soy sauce odor/flavor compared to the control made with the standard formula (CON). Elimination of sesame oil (ESO) significantly decreased sesame oil odor/flavor and oiliness, but increased green onion flavor. Elimination of garlic (EGC) significantly increased grilled beef odor/flavor, sesame oil odor/flavor, and oiliness, but decreased intensities of all the other attributes except bitterness. The consumers in Korea and the United States rated their overall liking for all samples similarly, preferring SSS to CON, EGC, and ESO. However Korean consumers seemed to detect the differences caused by formulation changes better than the U.S. consumers and these perceived differences seemed to impact the hedonic and the just-about-right ratings. Increase in soy sauce and sugar increased both Korean and the U.S. consumers' acceptability of Bulgogi, whereas eliminating garlic did not influence the consumer acceptability despite of its significant impact on sensory attributes.

PRACTICAL APPLICATION

The food industry is increasingly interested in ethnic foods that satisfy sophisticated appetite of today's consumers. Korean cuisine is recently gaining popularity and perceived as "adventurous and spicy," appealing to researchers and marketers in the food industry worldwide. However, it is not easy to develop a new product based on ethnic cuisine because nonsensory factors, such as food neophobia and openness to new culture, can evoke adverse responses from the consumers. A systematic sensory approach can guide the product development by identifying both sensory and nonsensory factors affecting consumer acceptability. This study investigated sensory attributes of Bulgogi (Korean traditional barbecued beef), one of the most famous Korean foods, and compared consumer acceptability between Korea and the United States. The outcomes of this study, such as flavor profiles, consumer responses, evaluation procedure, and approaches taken for cross-cultural comparison, will provide the food industries with valuable information that will help to develop effective strategies for commercializing ethnic foods including recipe development for Bulgogi marinades.

VDUP1 potentiates Ras-mediated angiogenesis via ROS production in endothelial cells

Vitamin D3 up-regulated protein 1 (VDUP1) is a tumor suppressor of which expression is reduced in a variety of cancer cells, and enforced expression inhibits the tumor cell proliferation. It inhibits the activity of thioredoxin, thus contributing cellular ROS generation. Since ROS is a critical factor for angiogenesis, we investigated the role of VDUP1 in angiogenesis and endothelial proliferation. The expression of VDUP1 was upregulated by overexpression of an oncogene, Ras. Enforced expression of VDUP1 increases ROS production and proliferation of Ras-overexpressing endothelial cells. Overexpression of VDUP1 increases the resistance to the anchorage-dependent cell death and tube formation of the Ras-overexpressing endothelial cell. In addition, the removal of ROS by ROS scavenger attenuates the effect of VDUP1 on tube formation. These results suggest that VDUP1 is involved in Ras-mediated angiogenesis via ROS generation in endothelial cells.

Carrier-mediated antiferromagnetic interlayer exchange coupling in diluted magnetic semiconductor multilayers Ga1-xMnxAs/GaAs:Be

We report the antiferromagnetic (AFM) interlayer exchange coupling between Ga0.97Mn0.03As ferromagnetic semiconductor layers separated by Be-doped GaAs spacers. Polarized neutron reflectivity reveals a characteristic splitting at the wave vector corresponding to twice the multilayer period, indicating that the coupling between the ferromagnetic layers is AFM. When the applied field is increased to above the saturation field, this AFM coupling is suppressed. This behavior is not observed when the spacers are undoped, suggesting that the observed AFM coupling is mediated by doped charge carriers.

Stability of zinc oxide nanofluids prepared with aggregated nanocrystalline powders

Aqueous zinc oxide (ZnO) suspensions were prepared using a two-step preparation method in which an aggregated nanocrystalline ZnO powder was dispersed in water using a polyelectrolyte. The fluid showed anomalously high thermal conductivity when compared with the Maxwell and Hamilton-Crosser predictions. However, analysis of the particle size distribution showed that the fluid contained aggregated 20 nm crystallites of ZnO with a high volume fraction of particles larger than 100 nm. Sedimentation experiments revealed that particles settled out of the stationary fluid over times ranging from 0.1 hours to well over 10,000 hours. The size of the particles remaining in suspension agreed well with predictions made using Stoke's law, suggesting flocculation was not occurring in the fluids. Finally, a new concept of nanofluid stability is introduced based on the height of the fluid, sedimentation, Brownian motion and the kinetic energy of the particles.

Metabolic syndrome and visceral obesity as risk factors for reflux oesophagitis: a cross-sectional case-control study of 7078 Koreans undergoing health check-ups

BACKGROUND

Obesity has been associated with reflux oesophagitis. However, the relationship between metabolic syndrome characterised by visceral obesity and reflux oesophagitis is unclear.

AIM

To investigate whether metabolic syndrome or visceral obesity is a risk factor for reflux oesophagitis.

METHODS

A cross-sectional study of 7078 subjects undergoing upper endoscopy during health check-ups was conducted (3539 patients with reflux oesophagitis vs age- and sex-matched controls). We further analysed according to categories of visceral adipose tissue and subcutaneous adipose tissue area with 750 cases and age-, sex- and waist circumference-matched controls who underwent abdominal CT scan.

RESULTS

The prevalence of metabolic syndrome was higher in cases than controls (26.9% vs 18.5%, p<0.001). Multivariate analysis demonstrated that metabolic syndrome is associated with reflux oesophagitis (odds ratio (OR) = 1.42; 95% confidence interval (CI), 1.26 to 1.60). Among the individual components of metabolic syndrome, waist circumference (OR = 1.47; 95% CI, 1.30 to 1.65) and triglyceride (OR = 1.20; 95% CI, 1.05 to 1.36) independently increased the risk for reflux oesophagitis. On sub-analysis, cases showed higher mean visceral adipose tissue area (cm(2)) (136.1 (SD 57.8) vs 124.0 (SD 54.7), p<0.001) and subcutaneous adipose tissue area (cm(2)) (145.9 (SD 56.8) vs 133.5 (SD 50.7), p<0.001). However, only visceral adipose tissue area was an independent risk factor for reflux oesophagitis after adjusting for multiple confounders including smoking, alcohol, body mass index (BMI) and subcutaneous adipose tissue area (OR = 1.60; 95% CI, 1.03 to 2.48, lowest quartile vs highest quartile).

CONCLUSIONS

Metabolic syndrome was associated with reflux oesophagitis. Abdominal obesity, especially visceral obesity, was an important risk factor for reflux oesophagitis.

Pharmacokinetic interaction between DA-8159, a new erectogenic, and metformin in rats: competitive inhibition of metabolism via hepatic CYP3A1/2

BACKGROUND AND PURPOSE

Erectile dysfunction is highly prevalent in diabetic patients and PDE V inhibitors are effective and safe for the treatment of erectile dysfunction in men with diabetes. Therefore, in this study we investigated whether a pharmacokinetic interaction occurs between DA-8159 and metformin, as both drugs are metabolized via hepatic CYP3A1/2 in rats.

EXPERIMENTAL APPROACH

DA-8159 (30 mg kg(-1)) and metformin (100 mg kg(-1)), both separately and together, were administered to rats either intravenously or orally. The V (max), K (m), CL(int), apparent inhibition constants (K (i)), [I]/K (i) and concentrations of each drug in the liver and intestine were then measured.

KEY RESULTS

After i.v. administration of both drugs simultaneously, the AUC of DA-8159 and metformin was significantly greater (21.2 and 33.9% increase for DA-8159 and metformin, respectively) than that of each drug alone. After p.o. administration of the drugs, the AUC of metformin was also significantly greater (20.7% increase) in the presence of DA-8159 than in its absence. However, the AUC of DA-8159 was similar in the absence and presence of metformin.

CONCLUSIONS AND IMPLICATIONS

The significantly greater AUC of metformin and DA-8159 after i.v. administration of both drugs and of metformin after p.o. administration of both drugs is probably due to competitive inhibition for the metabolism of these drugs via hepatic CYP3A1/2. However, the similar AUCs of DA-8159 in the absence and presence of metformin, after p.o. administration, indicates that the dose of metformin used was insufficient to inhibit the hepatic and intestinal metabolism of DA-8159.

Detection of CSF leak in spinal CSF leak syndrome using MR myelography: correlation with radioisotope cisternography

BACKGROUND AND PURPOSE

Spinal CSF leak syndrome is a unique disorder caused by spinal CSF leak. In this study, we attempted to determine whether MR myelography (MRM) can detect the leakage site in the spine.

MATERIALS AND METHODS

We performed both MRM and radioisotope cisternography (RIC) in 15 patients with spinal CSF leak syndrome. Patients were included in this study if they had at least 2 of the following criteria: 1) orthostatic headache, 2) low CSF opening pressure, and 3) diffuse pachymeningeal enhancement on brain MR imaging. For comparison, we performed MRM in 15 subjects without symptoms of spinal CSF leak syndrome. MRM was performed with the 2D turbo spin-echo technique in the entire spine by using a 1.5T scanner. Two blinded radiologists evaluated the MRM findings in a total of 30 cases, composed of patient and control groups, with regard to the presence of leakage and the level of leakage if present. RIC was performed only in the patient group and was assessed by consensus among 3 physicians experienced in nuclear medicine. The diagnostic performance of MRM and RIC was evaluated on the basis of the clinical diagnosis of spinal CSF leak syndrome.

RESULTS

The sensitivity, specificity, and accuracy of MR myelography for detecting CSF leak was 86.7%, 86.7%, and 86.7% for reader 1, respectively, and 80.0%, 93.3%, and 86.7% for reader 2, respectively. The sensitivity of RIC was 93.3%. Agreement between the 2 techniques for the detection of CSF leak was substantial in reader 1 and moderate in reader 2 (kappa = 0.634 and 0.444, respectively).

CONCLUSION

MRM is an effective tool for detecting CSF leak in the spine in patients with spinal CSF leak syndrome.

Effects of steeping conditions of waxy rice on the physical and sensory characteristics of gangjung (a traditional Korean oil-puffed snack)

The objectives of this study were to investigate the effects of steeping period (1, 11, and 21 d) and temperature (15, 25, and 35 degrees C) of waxy rice on the physical and sensory characteristics of Gangjung (a traditional Korean oil-puffed snack). Increasing the steeping period from 1 to 21 d and increasing the temperature from 15 to 35 degrees C markedly increased the oil absorption ratio of Gangjung. Textural analysis indicated that the number of peaks (representing the internal air cell characteristics) for Gangjung decreased in proportion with increasing steeping temperature and period, but that the hardness was affected significantly only by steeping period. Regarding the sensory characteristics of Gangjung, 5 appearance, 7 flavor, and 9 texture attributes were developed and evaluated by trained descriptive panelists. When the steeping temperature and the steeping period were increased, the degree of expansion, size, and degree of external roughness increased, while the strength of external color decreased. Regarding the flavor attributes, the intensity of sweetness and toasted carbohydrate food flavor tended to decrease with increasing steeping temperature and period, while sourness and butyric acid flavor, which are related to the fermentation of waxy rice, increased. Finally, the increased steeping temperature and period decreased the intensity of hardness, crispness, and toughness of Gangjung but increased the degree of fracture, degree of melting, and oiliness.

Helicobacter pylori eradication for low-grade gastric mucosa-associated lymphoid tissue lymphoma is more successful in inducing remission in distal compared to proximal disease

A series of studies has shown that Helicobacter pylori eradication induces remission in most patients with low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, there have been few reports about the effect of bacterial treatment on the gastric MALT lymphoma in Korea, a well-known H. pylori endemic area. A total of 111 H. pylori-infected patients were prospectively enrolled in Seoul National University Hospital and 99 among them were completely followed up according to our protocol. After H. pylori eradication, tumoural response was evaluated by endoscopy and histopathology every 2–3 months till complete remission (CR) and every 6 months after achieving CR. Median follow-up period was 41 months (range, 11–125 months). Helicobacter pylori was successfully eradicated in all 99 patients and CR was obtained in 84 (84.8%) of 99 patients. The median time to reach CR was 3 months and 94% of CR is in continuous complete remission. Five patients with CR relapsed after 10–22 months without the evidence of H. pylori reinfection. Cumulative recurrence rate was 2.3, 7.7 and 9.3% at 1, 2 and 3 years, respectively. Tumours were mainly located in distal stomach (67.7%) and tumours in distal stomach were associated with more favourable response than those in proximal stomach (P=0.001). Majority of patients with low-grade gastric MALT lymphoma treated by exclusive H. pylori eradication have a favourable long-term outcome, offering a real chance of cure. Tumour location could be a predictive factor for remission following H. pylori eradication.

Destruction of EDTA by mediated electrochemical oxidation process: monitoring by continuous CO2 measurements

The mediated electrochemical oxidation (MEO) process with cerium(IV) in nitric acid as the oxidizing medium was employed for the destruction of ethylenediaminetetraacetic acid (EDTA) in batch and continuous feeding modes. A complete mineralization of EDTA to CO(2) and water was achieved. The system parameters studied were the temperature (343, 353 and 368 K), concentration of nitric acid (2, 3 and 4M), Ce(IV) concentration (0.7-0.95 M), aqueous EDTA concentration (67-268 mM) , flow rate of EDTA addition (3.0-7.5 ml/min), and feeding time (30 min and 2h). The batch process CO(2) pattern clearly showed two distinct kinetic regimes. Accordingly the overall CO(2) formation rate constants were evaluated for fast and slow processes using pseudo first-order kinetics. In case of continuous organic feeding, the CO(2) formation rate constant was obtained using a new proposed mathematical procedure based on geometrical progression. The only parameter in the calculations was the first-order rate constant. The theoretical CO(2) evolution pattern was fitted on to the experimental data to obtain the formation rate constants. The activation energy was calculated based on the CO(2) formation constants and presented. The application of mathematical procedure predicted a steady-state attainment of CO(2) evolution for the destruction process during a long-term organic feeding and observed experimentally.

Stable multidomain structures formed in the process of magnetization reversal in GaMnAs ferromagnetic semiconductor thin films

The process of magnetization reversal in ferromagnetic Ga(1-x)Mn(x)As epilayers has been systematically investigated using the planar Hall effect (PHE). Interestingly, we have observed a pronounced asymmetry in the PHE hysteresis when the range of the field scan is restricted to fields below the final magnetization transition. The observed behavior indicates that (a) multidomain structures are formed as M undergoes a reorientation, (b) the domain landscape formed in this way remains stable even after the magnetic field is switched off, and (c) the reorientation of magnetization directions corresponding to the transition points in PHE takes place separately within each domain.

Preliminary studies using hybrid mediated electrochemical oxidation (HMEO) for the removal of persistent organic pollutants (POPs)

This study investigates the hybrid mediated electrochemical oxidation (HMEO) technology, which is a newly developed non thermal electrochemical oxidation process for organic destruction. A combination of ozone and ultrasonication processes to the mediated electrochemical oxidation (MEO) process is termed as hybrid mediated electrochemical oxidation. The electrochemical cell was developed in this laboratory. In the present study, several organic compounds, such as phenol, benzoquinone and ethylenediaminetetraacetic acid (EDTA), were chosen as the model organic pollutants to be destructed by the hybrid process. The organic destruction was monitored based on the CO2 generation and total organic carbon (TOC) reduction. The HMEO process was found to be extremely effective in the destruction of all the target organics chosen in this study. The information obtained from this study will provide an insight in adopting this technique for dealing with more recalcitrant organics (POPs).

Subdural hematoma in spontaneous CSF hypovolemia

Of 67 consecutive patients with spontaneous CSF hypovolemia (SCH), 11 (16.4%) had subdural hematoma (SDH). Patients with SDH were older (p = 0.005), more likely to be male (p = 0.035), and displayed longer time to diagnosis of SCH (p = 0.019) than those without SDH. All patients with SDH showed the findings of pseudo-subarachnoid hemorrhage on CT and responded favorably to epidural blood patches and neurosurgical drainage.

Assessment of converting from intravenous to oral administration of cyclosporin A in pediatric allogeneic hematopoietic stem cell transplant recipients

We studied the administration method during a transition period from continuous intravenous (i.v.) infusion to oral administration of cyclosporin A (CsA). Thirty-two pediatric hematopoietic stem cell transplant (HSCT) recipients, between the ages of 8 months and 15.6 years (median 7.1 years) participated in this study. The pharmacokinetic properties of CsA was evaluated during the transition period from i.v. to oral CsA. The daily oral dose of CsA was three times higher than the i.v. dose. Oral dosing began immediately after the continuous infusion was discontinued. Whole-blood CsA concentrations were measured by a monoclonal fluorescence polarization immunoassay (FPIA). The mean+/-s.d. value of bioavailability (F), maximum concentration (C(max)), half-life (t(1/2)) of CsA were 43.1+/-14.4%, 1135.3+/-340.6 ng/ml and 3.1+/-1.2 h, respectively. Mean clearance (CL)+/-s.d. was 480.9+/-103.7, 414.9+/-137.1 and 320+/-51.8 ml/h/kg in patients <20, 20-40 and >40 kg of body weight, respectively. The CsA CL of younger children was significantly greater than for older children (P=0.044). CsA trough levels were maintained within the therapeutic range throughout the transition period. Therefore, our findings suggest that the immediate administration of an oral formulation, after discontinuation of the continuous infusion, would be practical and effective for routine clinical use.

Stable bioavailability of cyclosporin A, regardless of food intake, from soft gelatin capsules containing a new self-nanoemulsifying formulation

AIM

We recently succeeded in preparing soft gelatin capsules containing a new self-nanoemulsifying formulation consisting of cyclosporin A (CsA), triacetin, polyoxyl 40 hydrogenated castor oil, polysorbate 20, medium chain triglycerides and medium chain mono- and diglycerides. The soft capsules containing the new formulation exhibited a significantly improved physical stability in terms of the appearance of the gelatin capsule shells and the composition of the fill mass during long-term storage, compared to commercially available soft capsules containing CsA, in which ethanol was employed as a cosolvent of CsA. In the present study, the influence of a fat-rich meal on the bioavailability of CsA from the soft capsule containing the new formulation (test drug) was evaluated and the results compared to those obtained with a representative soft capsule of CsA.

VOLUNTEERS AND METHODS

A randomized, open-label, 3-way crossover study was performed in the test capsules and reference soft capsules, in a fasted state or after a fat-rich breakfast. 18 healthy male volunteers received a single dose of the reference formulation (Neoral, Novartis AG, Basel, Switzerland) or test formulation (2 capsules each, 200 mg as CsA) with 240 ml of water with a 1-week washout period between the treatments, after a fat-rich (670 kcal, 45 g fat) breakfast (for the test drug, Treatment A; for the reference drug, Treatment B) or a 12-h fasting (for the test drug, Treatment C). Serial blood samples, collected over a 24-h period after the administration, were assayed for blood CsA concentrations using a specific monoclonal radioimmunoassay.

RESULTS

The differences in bioavailability parameters (i.e., AUC(0-24h), AUC(0-infinity) and C(max)) between the treatments were within the range of 80-125% of the reference treatment. An analysis of variance (ANOVA) revealed no significant differences (p > 0.05) between subjects, formulations or periods. The 90% confidence intervals (CI) indicated that the differences between the treatments (Treatments A and B, Treatments A and C) were also within the criteria.

CONCLUSION

These results indicate that the bioavailability of CsA from the test drug is equivalent to reference in the fed state, and is likely to be less influenced by a fat-rich meal. Therefore, the new formulation of CsA using triacetin appears to have an advantage over the commercial soft capsules of CsA using a volatile cosolvent such as ethanol.

Plasma low-molecular weight fluorescence in type 1 diabetes mellitus

Characteristic tissue fluorescence is associated with advanced glycation end product (AGE) accumulation in experimental diabetes models, but its utility in patients with type 1 diabetes remains to be established. We studied 148 patients with type 1 diabetes and 77 healthy age-matched control subjects. Low-molecular weight (LMW) fluorophore levels were estimated in plasma samples obtained after an overnight fast. Intra- and interassay coefficients of variation were 4.7% and 6.4%, respectively. LMW fluorophore levels were significantly higher in patients with diabetes than in control subjects (6.3 +/- 0.6 AU/mL vs. 4.1 +/- 0.3; P = 0.007). However, all of this difference came from patients with microvascular complications (n = 67, 7.5 +/- 1.3). There was no significant difference in LMW fluorescence between complication-free patients (4.4 +/- 0.2) and control subjects (P > 0.05). On multivariate analysis, LMW fluorophores correlated with measures of renal function (P < 0.05) but not with diabetes per se. In addition, there was no correlation between LMW fluorophores and the markers of oxidative stress or systemic inflammation. Longitudinal and interventional studies are required to determine whether the association between LMW fluorophores and nephropathy is cause or effect.

Polycarboxylic acid nanoparticles for ophthalmic drug delivery: an ex vivo evaluation with human cornea

In ophthalmic drug delivery, a major problem is retaining an adequate concentration of a therapeutic agent in the pre-corneal area. Polycarboxylic acid carriers such as polyacrylic acid and polyitaconic acid in sub-colloidal, nanoparticulate hydrogel form have a strong potential for sustained release of a drug in ocular delivery. Formulations have been prepared of brimonidine loaded in polycarboxylic (polyacrylic and polyitaconic) acid nanoparticles for potential ophthalmic delivery. These particles were prepared by a reverse micro-emulsion polymerization technique with sizes in the range of 50 nm. The loading efficiencies of the drug brimonidine in the particles were shown to be between 80-85% for polyacrylic acid nanoparticles and between 65-70% for polyitaconic nanoparticles. The loading efficiency was also found to be pH dependent. In a preliminary biocompatibility test, human corneal epithelial cells incubated with polyacrylic acid nanoparticles were found to retain their viability, whereas polyitaconic acid nanoparticles were found to be toxic. Two-photon laser scanning microscopic studies of the fluorescently labelled polyacrylic acid nanoparticles and human cornea shows that they are adhesive on the corneal surface. The polyacrylic acid nanoparticles demonstrated a controlled release of the opthalmological drug (Brimonidine) through the human cornea as compared to that of the commercial formulation, Alphagan.