A lysosomal enigma CLN5 and its significance in understanding neuronal ceroid lipofuscinosis

Neuronal Ceroid Lipofuscinosis (NCL), also known as Batten disease, is an incurable childhood brain disease. The thirteen forms of NCL are caused by mutations in thirteen CLN genes. Mutations in one CLN gene, CLN5, cause variant late-infantile NCL, with an age of onset between 4 and 7 years. The CLN5 protein is ubiquitously expressed in the majority of tissues studied and in the brain, CLN5 shows both neuronal and glial cell expression. Mutations in CLN5 are associated with the accumulation of autofluorescent storage material in lysosomes, the recycling units of the cell, in the brain and peripheral tissues. CLN5 resides in the lysosome and its function is still elusive. Initial studies suggested CLN5 was a transmembrane protein, which was later revealed to be processed into a soluble form. Multiple glycosylation sites have been reported, which may dictate its localisation and function. CLN5 interacts with several CLN proteins, and other lysosomal proteins, making it an important candidate to understand lysosomal biology. The existing knowledge on CLN5 biology stems from studies using several model organisms, including mice, sheep, cattle, dogs, social amoeba and cell cultures. Each model organism has its advantages and limitations, making it crucial to adopt a combinatorial approach, using both human cells and model organisms, to understand CLN5 pathologies and design drug therapies. In this comprehensive review, we have summarised and critiqued existing literature on CLN5 and have discussed the missing pieces of the puzzle that need to be addressed to develop an efficient therapy for CLN5 Batten disease.

Effects of Organic Light-Emitting Diodes on Circadian Rhythm and Sleep

OBJECTIVE

Organic light-emitting diodes (OLEDs) emit less blue light than traditional light-emitting diodes (LEDs), and we previously found that early-night OLED light exposure (LE) delays the melatonin phase by less than LED at a color temperature of 4,000 K. As a follow-up study, we investigated the effects of OLED and LED at a different color temperature (3,000 K) on melatonin profile, sleep, and vigilance.

METHODS

24 healthy subjects (27.5±5.1 years) were exposed to three light conditions [OLED, LED, and dim light (DL)] from 17:30 to 24:00, in a random order and with a 1-week interval. Saliva samples for melatonin were taken every hour from 18:00 to 24:00. Polysomnography (PSG) and a psychomotor vigilance test (PVT) were performed.

RESULTS

Melatonin onset time was significantly delayed under OLED and LED compared with DL, with no significant difference between OLED and LED. The mean melatonin level at 24:00 under LED was lower than that under DL, but there was no significant difference between OLED LE and DL. The percentage of slow wave sleep (N3) in LED was significantly lower than in OLED.

CONCLUSION

Exposure to light in the evening can suppress melatonin secretion late at night and disturb deep sleep, and those effects are slightly worse under LED than OLED.

Multiple-Cycle Polymeric Extracellular Vesicle Precipitation and Its Evaluation by Targeted Mass Spectrometry

The multiple roles of extracellular vesicles (EVs) in pathogenesis have received much attention, as they are valuable as diagnostic and prognostic biomarkers. We employed polymeric EV precipitation to isolate EVs from clinical specimens to overcome the limitations of ultracentrifugation (UC), such as low protein yields, a large volume of specimens used, and time requirements. Multiple-cycle polymeric EV precipitation was applied to enhance the purity of the EV fractions with a small sample volume. Then, the purity was assessed using a multiple reaction monitoring (MRM) panel consisting of alpha-2-macroglobulin (A2M), thrombospondin 1 (THBS 1), galectin 3 binding protein (LGALS3BP), and serum albumin (ALB). For purity evaluation, the EV fractions isolated from blood specimens were subjected to shotgun proteomics and MRM-based targeted proteomics analyses. We demonstrate that the modified method is an easy and convenient method compared with UC. In the shotgun proteomics analysis, the proteome profile of EV fraction contains 89% EV-related proteins by matching with the EVpedia database. In conclusion, we suggest that multiple-cycle polymeric EV precipitation is not only a more effective method for EV isolation for further proteomics-based experiments, but may also be useful for further clinical applications due to the higher EV yield and low sample requirements.

Measuring fucosylated alpha-fetoprotein in hepatocellular carcinoma: A comparison of μTAS and parallel reaction monitoring

PURPOSE

Fucosylation of alpha-fetoprotein (AFP) is closely correlated with the diagnosis of patients with hepatocellular carcinoma (HCC). In current, a micro-total analysis system (μTAS) using immunoassay has been developed for determining fucosylated AFP EXPERIMENTAL DESIGN: We compared two analytical methods, μTAS and liquid chromatography-parallel reaction monitoring mass spectrometry (LC-PRM MS), for the measurement of fucosylated AFP in serum to evaluate the usefulness of the results. For this purpose, serum samples were used (cirrhosis, n = 105; HCC, n = 105), and we have discussed the analytical performance of these two methods RESULTS: We observed a correlation (R²  = 0.84) between LC-PRM MS and μTAS using samples where fucosylated levels were measured by both methods. The fucosylated level of AFP by LC-PRM MS better differentiated between cirrhosis and HCC patients than those by μTAS (AUC = 0.910 vs. 0.861), particularly in subgroups with a level of total AFP < 20 ng/mL (0.973 vs. 0.874) and in early stage (I and II) patients (0.922 vs. 0.835) CONCLUSIONS AND CLINICAL RELEVANCE: From this comparative study we can suggest that the LC-PRM MS is applicable in the measurement of fucosylated AFP from human serum and is more useful for early diagnosis of HCC.

CLINICAL RELEVANCE

Fucosylation of AFP is used for the detection of HCC. A micro-total analysis system (μTAS) has been only developed for measuring fucosylation of AFP in clinical research. This study reports the fucosylation of AFP in human serum samples from cirrhosis and HCC patients using the μTAS and a LC-PRM MS to evaluate fucosylation of AFP from each method. As a result, LC-PRM MS is complementary to the conventional μTAS method. Furthermore, LC-PRM MS provides a higher diagnostic accuracy than the μTAS in patients with low AFP levels and an early stage.

Individualized Vancomycin Dosing with Therapeutic Drug Monitoring and Pharmacokinetic Consultation Service: A Large-Scale Retrospective Observational Study

Background

To date, outcome data with a large sample size and data regarding the clinical outcomes of pharmacokinetic-guided (PK) dosing of vancomycin are limited.

Aim

We evaluated the pharmacokinetic and clinical outcomes of a PK-guided dosing advisory program, pharmacokinetic consultation service (PKCS), in vancomycin treatment.

Methods

We investigated vancomycin therapeutic drug monitoring (TDM) and PKCS use through a retrospective review of patients who had serum vancomycin trough concentration data from October 2017 to November 2018. Among these patients, we selected non-critically ill adult patients satisfying our selection criteria to evaluate the effect of PKCS. Target trough attainment rate, time to target attainment, vancomycin-induced nephrotoxicity (VIN), vancomycin treatment failure rate, and duration of vancomycin therapy were compared between patients whose dosing was adjusted according to PKCS (PKCS group), and those whose dose was adjusted at the discretion of the attending physician (non-PKCS group).

Results

A total of 280 patients met the selection criteria for the VIN analysis (PKCS, n=134; non-PKCS, n=146). The incidence of VIN was similar between the two groups (PKCS, n=5; non-PKCS, n=5); however, the target attainment rate was higher in the PKCS group (75% vs 60%, P = 0.012). The time to target attainment was similar between the two groups. Further exclusions yielded 112 patients for the clinical outcome evaluation (PKCS, n=51; non-PKCS, n=61). The treatment failure rate was similar, and the duration of vancomycin therapy was longer in the PKCS group (12 vs 8 days, P = 0.008).

Conclusion

In non-critically ill patients, an increase in target trough achieved by PKCS did not lead to decreased vancomycin treatment failures, shorter vancomycin treatment, or decreased nephrotoxicity in vancomycin treatment. Considering the excessive amount of effort currently put into vancomycin dosing and monitoring, more selective criteria for individualized pharmacokinetic-guided dosing needs to be applied.

Seed dormancy and germination of Asarum sieboldii, a disjunct relict species in East Asia

Disjunct species in the same genus are a common feature of the flora in the temperate forests of East Asia and eastern North America. This study aimed to evaluate whether the kind of seed dormancy was maintained after species in the genus Asarum (Aristolochiaceae) were separated from their common ancestor. We classified the seed dormancy of Asarum sieboldii, an East Asian species, based on a phenology study and experiments in controlled temperature conditions, and then compared it to that of the previously studied A. canadense, an eastern North American species. The underdeveloped embryo of A. sieboldii grew and germinated (radicle emergence) in autumn but shoot emergence did not occur until the following spring. The seeds of A. sieboldii had deep simple epicotyl morphophysiological dormancy because the seeds with emerged radicle required a relatively long period of cold stratification to break epicotyl dormancy and produce a shoot. Although the seed of A. sieboldii had weaker radicle dormancy and stronger epicotyl dormancy compared to A. canadense, the kind of seed dormancy was the same for the two species. The trait of seed dormancy was inherited from a shared common ancestor and maintained in populations well after the two species (or their ancestors) separated. However, quantitative differences in temperature requirements for radicle and shoot emergence suggest the possibility of adaptation to the environment.

Alteration of transthyretin and thyroxine-binding globulin in major depressive disorder: multiple reaction monitoring-based proteomic analysis

Background

Major depressive disorder (MDD), common mental disorder, lacks objective diagnostic and prognosis biomarkers. The objective of this study was to perform proteomic analysis to identify proteins with changed expression levels after antidepressant treatment and investigate differences in protein expression between MDD patients and healthy individuals.

Methods

A total of 111 proteins obtained from literature review were subjected to multiple reaction monitoring (MRM)-based protein quantitation. Finally, seven proteins were quantified for plasma specimens of 10 healthy controls and 78 MDD patients (those at baseline and at 6 weeks after antidepressant treatment of either selective serotonin reuptake inhibitors (SSRIs) or mirtazapine).

Results

Among 78 MDD patients, 35 patients were treated with SSRIs and 43 patients were treated with mirtazapine. Nineteen (54.3%) and 16 (37.2%) patients responded to SSRIs and mirtazapine, respectively. Comparing MDD patients with healthy individuals, alteration of transthyretin was observed in MDD (P = 0.026). A few differences were observed in protein levels related to SSRIs treatment, although they were not statistically significant. Plasma thyroxine-binding globulin (TBG) was different between before and after mirtazapine treatment only in responders (P = 0.007).

Conclusions

In proteomic analysis of plasma specimens from MDD patients, transthyretin and TBG levels were altered in MDD and changed after antidepressant treatment.

Associations between Chewing Difficulty, Subjective Cognitive Decline, and Related Functional Difficulties among Older People without Dementia: Focus on Body Mass Index

OBJECTIVE

This study aimed to determine whether chewing difficulty is associated with subjective cognitive decline (SCD) and related functional difficulties by body mass index.

DESIGN

A population-based cross-sectional study.

SETTING AND PARTICIPANTS

A nationwide sample of 54,004 individuals aged ≥65 years from the 2018 Korea Community Health Survey.

MEASUREMENTS

SCD and SCD-related functional difficulties were measured using the cognitive decline module of the Behavioral Risk Factor Surveillance System. Chewing difficulty was assessed based on a self-report questionnaire from an oral health-related behaviors interview survey. BMI was calculated from objective values by measuring height and weight through a physical meter.

RESULTS

Among the 54,004 individuals, the prevalence of SCD in underweight, overweight, and obesity group was 33.6% (n = 806), 30.3% (n = 9,691), and 28.7% (n=5,632) respectively. Chewing difficulty was associated with SCD and SCD-related functional difficulties. This association was more pronounced in underweight (BMI: <18.5 kg/m2) people [underweight: (odds ratio [OR] = 1.68, 95% confidence interval [CI] 1.48-1.92); normal weight: OR = 1.13, 95% CI 1.04-1.22; obese: OR = 1.15, 95% CI 1.05-1.27]. Similar trends were demonstrated for SCD-related functional difficulties (underweight: OR = 1.53, 95% CI 1.17-2.01; normal weight: OR = 1.36, 95% CI 1.15-1.63; obese: OR = 1.50, 95% CI 1.22-1.86).

CONCLUSIONS

Chewing difficulty was associated with SCD and SCD-related functional difficulties in older people. Our results suggest that underweight status may play roles in the associations between chewing difficulty and SCD and SCD-related functional difficulties.

Prevalence of Anemia and Its Association with Frailty, Physical Function and Cognition in Community-Dwelling Older Adults: Findings from the HOPE Study

OBJECTIVES

The prevalence of anemia and its impact on frailty and physical function amongst the multiethnic older populations in the Southeast Asian (SEA) countries are often not well studied. Singapore, a nation comprised of multiethnic communities, is one of the most rapidly aging population globally. We aim to evaluate the prevalence of anemia and its impact on frailty, and physical function in Healthy Older People Everyday (HOPE)- an epidemiologic population-based study on community-dwelling older adults in Singapore.

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

480 adults ≥ 65 years old.

MEASUREMENTS

Data were collected from interviewers-administered questionnaires on socio-demographics, FRAIL scale, Mini-Mental State Examination, EQ-5D, Barthel Index, and Lawton index. Hemoglobin concentration and physical assessments, including anthropometry, grip strength, timed up-and-go (TUG) were measured.

RESULTS

The overall prevalence of anemia was 15.2% (73 out of 480). The Indian ethnic group had the highest prevalence of anemia (32%, OR=3.02; 95%CI= 1.23-7.41) with the lowest hemoglobin concentration compared to the overall population (13.0±1.3g/L and 13.5±1.4g/L, p=0.02). Hemoglobin levels and anemia were significantly associated with frailty (OR=2.28; 95% CI=1.02-5.10), low grip strength (OR=1.79; 95% CI=1.01-3.03), ≥ one IADL impairment (OR=2.35; 95% CI=1.39-3.97). Each 1 g/dL increase in hemoglobin was associated with a 6% decrease in frailty odds after adjusting for potential covariates (OR = 0.94, 95% CI: 0.90-0.99). There was a significant difference in the mean TUG between the non-anemic (11.0±3.4 seconds) and anemic (12.3±6.0 seconds, p=0.01) counterparts, but no difference in the number of falls.

CONCLUSION

In our multiethnic Asian population, anemia was adversely associated with frailty, decreased muscle strength, and IADL impairment. Health policies on anemia screening should be employed to avoid or potentially delay or reverse these adverse outcomes associated with anemia. Recognition, evaluation, and treatment of anemia amongst this vulnerable population is warranted.

The Identification of a Novel Thiopurine S-Methyltransferase Allele, TPMT*45, in Korean Patient with Crohn's Disease

Pediatric Crohn’s disease (CD) carries a higher genetic susceptibility and an increased risk of a more aggressive disease course than adult CD. Treatment of CD is based on immunomodulatory drugs, such as thiopurines. The enzyme mainly involved in drug metabolism is thiopurine S-methyltransferase (TPMT). An increased concentration of drug metabolites can cause adverse drug effects, such as myelosuppression and hepatotoxicity; therefore, assessing the activity of TPMT is essential both before and during treatment. TPMT genotyping result is not affected by previous thiopurine dose and currently is the primary component of TPMT activity and disease monitoring. Until now, more than 40 allelic variants of the TPMT gene have been reported, with most of them having an uncertain or no enzyme function. In this article, we report the first case of a novel TPMT allele, TPMT*45, that was identified in a Korean girl with CD whose findings suggested decreased TPMT activity. This newly observed variant is caused by a single nucleotide polymorphism resulting in nonsense mutation (c.676C>T, p.R226*) and the partial loss of amino acids in the TPMT protein. Initially, the patient began azathioprine at a standard dosage (1.5 mg/kg/day), and her laboratory results, including red blood cell (RBC) TPMT activity (6-methylmercaptopurine 2.68 nmol/mL/h and 6-methylmercaptopurine riboside 4.82 nmol/mL/h) along with thiopurine metabolite levels (6-thioguanine nucleotides 479.3 pmol/8×10⁸ RBC), suggested an enzyme deficiency. The thiopurine dose was reduced to half (0.7 mg/kg/day), and the follow-up metabolite results as well as the associated inflammatory markers were continuously within reference ranges. Along with an improvement in the patient’s subjective reports and clinical symptoms, the patient demonstrated a good treatment response to the adjusted dose. The results of our report illustrate the importance of TPMT genotyping and pharmacogenetic-based thiopurine dose adjustment. Further research should focus on the functional characterization and impact on this novel allele’s treatment effect.

A Simple and High-throughput LC-MS/MS Method for Simultaneous Measurement of Nicotine, Cotinine, 3-OH cotinine, Nornicotine, and Anabasine in Urine and its Application in the General Korean Population

Measuring nicotine metabolites is the most objective method for identifying smoke exposure. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can measure multiple metabolites and is sensitive enough to detect low concentrations of metabolites. Therefore, we developed a simple and high-throughput method for measuring nicotine, cotinine, trans-3'-hydroxycotinine (3-OH cotinine), nornicotine, and anabasine for population-based studies using LC-MS/MS. Each 30 µl of urine sample was diluted with 90 µL of acetonitrile containing five deuterated internal standards. Chromatographic separation used a C18 column and LC-MS/MS analysis was performed with a multiple reaction monitoring mode. The chromatographic run time for each sample was 6.5 min. The method was validated by evaluating selectivity, interference, limit of detection, lower limit of quantification, precision, accuracy, linearity, extraction recovery, matrix effect, and carry-over according to guidelines. Our methods required a short preparation time (about 20 minutes) while simultaneously measuring five markers for smoking status. No endogenous or exogenous interference was found. Our method showed excellent precision and accuracy: within-run CV 2.9-9.4%, between-run CV 4.8-8.7%, and bias -10.1 to 5.3%. Linear dynamic ranges were 1-10,000 ng/mL for nicotine, nornicotine, and anabasine; 2-5,000 ng/mL for cotinine; and 5-15,000 ng/mL for 3-OH cotinine. Extraction recovery was consistent (87-109%) across concentrations. No significant matrix effect or carry-over was observed. The validated method was applied to 849 urine samples. In samples from the 125 current smokers, nicotine, cotinine, 3-OH cotinine, nornicotine, and anabasine were detected in 97.6%, 99.2%, 98.4%, 96.8%, and 87.2%, respectively. No markers were detected in 93.9% of 609 non-smokers. The overlapping detection of multiple markers made it possible to identify smoking status even in current smokers with low concentration of cotinine. Our LC-MS/MS method using a simple sample preparation technique is sensitive and effective for screening of smoking status in the general population.

Serum Vitamin Levels and Their Relationships with Other Biomarkers in Korean Breast Cancer Patients

Numerous studies have shown that vitamins reduce the risk of cancers, but the relationship between serum vitamin levels and breast cancer is still controversial. In this study, we evaluated serum levels of vitamins in Korean patients with benign breast disease or breast cancer and investigated their associations with clinical and laboratory parameters. Concentrations of vitamin A, D, and E, together with homocysteine and methylmalonic acid as biomarkers of vitamin B12 deficiency, were measured by high-performance liquid chromatography (HPLC) or liquid chromatography with tandem mass spectrometry (LC-MS/MS) in the serum of 104 breast cancer patients, 62 benign breast disease patients, and 75 healthy Korean females. We further assessed possible associations between vitamin levels and breast cancer subtypes, the presence of lymph node metastasis, and tumor stages. Serum concentrations of vitamins A and E were significantly lower in breast cancer patients and in benign breast disease patients than in healthy controls. Severe vitamin D deficiency was more prevalent in breast cancer patients than in healthy controls. Vitamin D level was significantly lower in breast cancer patients with estrogen receptor-negative or triple-negative subtypes than in those with other subtypes. Further research with a larger study population is required to elucidate the role of vitamins in breast cancer.

A Sensitive and Specific Liquid Chromatography-Tandem Mass Spectrometry Assay for Simultaneous Quantification of Salivary Melatonin and Cortisol: Development and Comparison With Immunoassays

Melatonin and cortisol are clinically important for diagnosing sleep and mood disorders. We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous measurement of salivary melatonin and cortisol concentrations according to the Clinical and Laboratory Standards Institute guidelines. Additionally, we compared the LC-MS/MS assay with immunoassays, ELISA (Direct Salivary Melatonin Elisa EK-DSM, Bühlmann Laboratories AG, Schönenbuch, Switzerland) and electrochemiluminescence immunoassay (Cortisol II, Roche, Mannheim, Germany), using 121 saliva samples. The LC-MS/MS assay exhibited good performance in terms of linearity, precision, accuracy, limit of detection, lower limit of quantification, extraction recovery, carry-over, and matrix effect. The LC-MS/MS assay and immunoassays showed strong correlation (Pearson’s r=0.910 for melatonin, r=0.955 for cortisol), but demonstrated a significant mean bias of 23.2% (range 54.0–143.7%) for melatonin and 48.9% (range 59.7–184.7%) for cortisol. Our LC-MS/MS assay provided more sensitive and reliable salivary melatonin and cortisol quantification results compared with immunoassays.

Adjustment of azathioprine dose should be based on a lower 6-TGN target level to avoid leucopenia in NUDT15 intermediate metabolisers

BACKGROUND

The association between NUDT15 polymorphisms and thiopurine-induced leucopenia is well known.

AIM

To investigate the association between NUDT15 polymorphisms and time-to-leucopenia in paediatric patients with inflammatory bowel disease (IBD) receiving azathioprine and to determine the relationship between NUDT15 polymorphisms and 6-thioguanine nucleotide (6-TGN) levels.

METHODS

This retrospective observational study included Korean paediatric patients with IBD who were treated with azathioprine and underwent NUDT15 and TPMT genotyping. Azathioprine doses were adjusted by regular thiopurine metabolite monitoring. Factors associated with time-to-leucopenia and the relationship between NUDT15 polymorphisms and 6-TGN levels were analysed.

RESULTS

Among the 167 patients included, leucopenia was observed in 16% (19/119), 44% (20/45) and 100% (3/3) of the NUDT15 normal, intermediate and poor metabolisers respectively (P < 0.001). NUDT15 polymorphism was significantly associated with time-to-leucopenia (HR = 5.26, 95% CI = 2.74-10.09, P < 0.001). There was a positive association between 6-TGN levels and leucopenia among the NUDT15 intermediate/TPMT normal metabolisers (median 361.3 vs 263.8 pmol/8 × 10⁸ RBC, P = 0.013). The most accurate 6-TGN cut-off level associated with leucopenia was 308.2 pmol/8 × 10⁸ RBC (AUC = 0.742, 95% CI = 0.569-0.915, sensitivity 80.0%, specificity 72.7%, P < 0.001) in this subgroup. When the specificity was set to <15%, the 6-TGN cut-off level was 167.1 pmol/8 × 10⁸ RBC (sensitivity 93.3%, specificity 13.6%).

CONCLUSIONS

NUDT15 polymorphisms were associated with time-to-leucopenia during azathioprine treatment in Korean paediatric patients with IBD. In order to reduce the development of thiopurine-induced leucopenia (<15%) in NUDT15 intermediate metabolisers, adjustment of azathioprine doses should be based on a lower 6-TGN target level (<167.1 pmol/8 × 10⁸ RBC).

Effects of various genetic polymorphisms on thiopurine treatment-associated outcomes for Korean patients with Crohn's disease

AIMS

This study explores the effects of various genetic polymorphisms in candidate genes on thiopurine metabolism and toxicity in adult patients with Crohn's disease in Korea.

METHODS

A total of 131 adult patients with Crohn's disease receiving thiopurine treatment were included. The TPMT and NUDT15 genes and an additional 116 genetic polymorphisms (in 40 genes and 3 intergenic locations) were screened for genotyping. Among the polymorphisms screened, 91 genetic polymorphisms (in 34 genes and 3 intergenic locations) in addition to TPMT and NUDT15 genotypes were included for statistical analyses to investigate their effects on thiopurine metabolites and adverse outcomes (leukopenia, hepatotoxicity, gastrointestinal intolerance, skin rash and alopecia).

RESULTS

The median duration of thiopurine treatment was 47.0 months (range 6.0-153.4 months). Patient sex, maintenance dose of thiopurine, and use of anti-tumour necrosis factor agents were associated with thiopurine metabolite concentrations (P < .05). In the univariate analysis, the TPMT genotype was associated with 6-thioguanine level (P < .05), although the significance of this did not remain in multivariate analysis. Genetic polymorphisms in the ATIC (rs3821353 and rs16853834), IMPDH2 (rs11706052) and ITPA (rs6139036) genes were associated with thiopurine metabolism (P < .05). Genetic polymorphisms in the ABCC5 (rs8180093) and NUDT15 genotypes were associated with leukopenia (P < .05).

CONCLUSION

The results of this study may help clinicians to understand the effects of other various polymorphisms in addition to TPMT and NUDP15 in thiopurine metabolism for management of Crohn's disease patients.

Risk of nosocomial transmission of coronavirus disease 2019: an experience in a general ward setting in Hong Kong

BACKGROUND

Coronavirus disease 2019 (COVID-19) was first reported in Wuhan in December 2019 and has rapidly spread across different cities within and outside China. Hong Kong started to prepare for COVID-19 on 31st December 2019 and infection control measures in public hospitals were tightened to limit nosocomial transmission within healthcare facilities. However, the recommendations on the transmission-based precautions required for COVID-19 in hospital settings vary from droplet and contact precautions, to contact and airborne precautions with placement of patients in airborne infection isolation rooms.

AIM

To describe an outbreak investigation of a patient with COVID-19 who was nursed in an open cubicle of a general ward before the diagnosis was made.

METHOD

Contacts were identified and risk categorized as 'close' or 'casual' for decisions on quarantine and/or medical surveillance. Respiratory specimens were collected from contacts who developed fever, and/or respiratory symptoms during the surveillance period and were tested for SARS-CoV-2.

FINDINGS

A total of 71 staff and 49 patients were identified from contact tracing, seven staff and 10 patients fulfilled the criteria of 'close contact'. At the end of 28-day surveillance, 76 tests were performed on 52 contacts and all were negative, including all patient close contacts and six of the seven staff close contacts. The remaining contacts were asymptomatic throughout the surveillance period.

CONCLUSION

Our findings suggest that SARS-CoV-2 is not spread by an airborne route, and nosocomial transmissions can be prevented through vigilant basic infection control measures, including wearing of surgical masks, hand and environmental hygiene.

A new aortoiliac calcification scoring system to predict grade C anastomotic leak following rectal cancer surgery

BACKGROUND

Aortoiliac calcification may be a surrogate marker of decreased visceral perfusion causing anastomotic leak (AL). The aim of this study was to evaluate the predictive role of aortoiliac calcification for AL after rectal cancer surgery.

METHODS

We enrolled patients with primary rectal cancer who had restorative resection at our institution between January 2013 and December 2015. An aortoiliac calcification score was calculated as the sum of calcification scores at the infrarenal aorta (0: no, 1: ≤ 3 cm, 2: > 3 cm) and the common iliac arteries (0: no, 1: unilateral, 2: bilateral). AL was classified into three grades: grade A, requiring no intervention; grade B, requiring therapeutic intervention without re-laparotomy; and grade C, requiring re-laparotomy. Clinicopathological characteristics were analyzed to identify risk factors for AL.

RESULTS

There were 583 patients. Three-hundred forty-five (59.2%) had an aortoiliac calcification score ≥ 3, and 37 (6.3%) patients experienced AL, in 30 cases (5.1%) grade C AL. Patients with an aortoiliac calcification score ≥ 3 had a higher incidence of grade C AL (6.7% vs. 2.9%, p = 0.045). Multivariate logistic regression analysis revealed that an aortoiliac calcification score ≥ 3 was an independent risk factor for grade C AL (odds ratio = 2.669, 95% confidence interval 1.066-6.686, p = 0.036).

CONCLUSIONS

Aortoiliac calcification may be considered a risk factor for grade C AL after rectal cancer surgery.

Intraoperative dexmedetomidine attenuates norepinephrine levels in patients undergoing transsphenoidal surgery: a randomized, placebo-controlled trial

Background

Dexmedetomidine has sympatholytic effects. We investigated whether dexmedetomidine could attenuate stress responses in patients undergoing endoscopic transnasal transseptal transsphenoidal surgery.

Methods

Forty-six patients were randomized to receive a continuous infusion of 0.9% saline (n = 23) or dexmedetomidine (n = 23). Immediately after general anesthesia induction, the dexmedetomidine group received a loading dose of 1 mcg/kg dexmedetomidine over 10 min, followed by a maintenance dose of 0.2–0.7 mcg/kg/h and the control group received 0.9% saline at the same volume until 30 min before the end of surgery. Serum levels of epinephrine, norepinephrine, and glucose were assessed before surgery (T1) and the end of drug infusion (T2). The primary outcome was the change in norepinephrine levels between the two time points.

Results

Changes (T2-T1 values) in perioperative serum norepinephrine levels were significantly greater in the dexmedetomidine group than in the control group (median difference, 56.9 pg/dL; 95% confidence interval, 20.7 to 83.8 pg/dL; P = 0.002). However, epinephrine level changes did not show significant intergroup differences (P = 0.208). Significantly fewer patients in the dexmedetomidine group than in the control group required rescue analgesics at the recovery area (4.3% vs. 30.4%, P = 0.047).

Conclusions

Intraoperative dexmedetomidine administration reduced norepinephrine release and rescue analgesic requirement. Dexmedetomidine might be used as an anesthetic adjuvant in patients undergoing transnasal transseptal transsphenoidal surgery.

Trial registration

Clinical Trial Registry of Korea, identifier: KCT0003366; registration date: 21/11/2018; presenting author: Ji Seon Jeong.

Weight-based vancomycin loading strategy may not improve achievement of optimal vancomycin concentration in patients with preserved renal function

We performed a retrospective study to evaluate clinical effectiveness of vancomycin loading strategy and factors associated with achieving optimal C _min. Patients administered vancomycin for ≥72 h from January to June 2018 were enrolled. Patients were divided into two groups: loading (LD) and non-loading (NLD). LD was defined as initial vancomycin dose ≥20 mg/kg and ≥120% of maintenance dose. During study period, 70 and 71 received initial LD (24.2 ± 2.5 mg/kg) and NLD (17.3 ± 3.3 mg/kg) doses of vancomycin, respectively (p < .001). Achievement of optimal C _min was not different before administration of the third dose (24.4% in LD versus 18.2% in NLD, p = .484) and within 72 h (22.9% versus 28.2%, p = .759). Risk factors for failure to achieve optimal C _min before administration of the third dose were higher creatinine clearance and higher level of serum albumin. Therefore, more sufficient loading or patient-specific dose strategies should be used to achieve optimal serum vancomycin C _min.

Stacking Fault Energy Analyses of Additively Manufactured Stainless Steel 316L and CrCoNi Medium Entropy Alloy Using In Situ Neutron Diffraction

Stacking fault energies (SFE) were determined in additively manufactured (AM) stainless steel (SS 316 L) and equiatomic CrCoNi medium-entropy alloys. AM specimens were fabricated via directed energy deposition and tensile loaded at room temperature. In situ neutron diffraction was performed to obtain a number of faulting-embedded diffraction peaks simultaneously from a set of (hkl) grains during deformation. The peak profiles diffracted from imperfect crystal structures were analyzed to correlate stacking fault probabilities and mean-square lattice strains to the SFE. The result shows that averaged SFEs are 32.8 mJ/m2 for the AM SS 316 L and 15.1 mJ/m2 for the AM CrCoNi alloys. Meanwhile, during deformation, the SFE varies from 46 to 21 mJ/m2 (AM SS 316 L) and 24 to 11 mJ/m2 (AM CrCoNi) from initial to stabilized stages, respectively. The transient SFEs are attributed to the deformation activity changes from dislocation slip to twinning as straining. The twinning deformation substructure and atomic stacking faults were confirmed by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The significant variance of the SFE suggests the critical twinning stress as 830 ± 25 MPa for the AM SS 316 L and 790 ± 40 MPa for AM CrCoNi, respectively.