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Purpose: To build an age prediction model, we measured CD4+ and CD8+ cells, and humoral components in canine peripheral blood. Materials and Methods: Large Belgian Malinois (BGM) and German Shepherd Dog (GSD) breeds (n=27), aged from 1 to 12 years, were used for this study. Peripheral bloods were obtained by venepuncture, then plasma and peripheral blood mononuclear cells (PBMCs) were separated immediately. Six myokines, including interleukin (IL)-6, IL-8, IL-15, leukemia inhibitory factor (LIF), growth differentiation factor 8 (GDF8), and GDF11 were measured from plasma and CD4+/CD8+ T-lymphocytes ratio were measured from PBMC. These parameters were then tested with age prediction models to find the best fit model. Results: we found that the T-lymphocyte ratio (CD4+/CD8+) was significantly correlated with age (r=0.46, p=0.016). Among the six myokines, only GDF8 showed a significant correlation with age (r=0.52, p=0.005). Interestingly, these two markers showed better correlations in male dogs than females, and BGM breed than GSD. Using these two age biomarkers, we could obtain the best fit in a quadratic linear mixed model (r=0.77, p=3×10-6). Conclusions: Age prediction is a challenging task because of complication with biological age. Our quadratic linear mixed model using CD4+/CD8+ ratio and GDF8 level showed a meaningful age prediction.

The catalytic hydrodeoxygenation (HDO) processes for upgrading pyrolysis bio-oils from wood pallet sawdust (WPS) were studied using activated carbon (AC) as a support of mono- (Co/AC and Fe/AC) and bi-metallic (Co-Fe/AC) catalysts. The effects of the reaction temperature and hydrogen pressure on products and high heating value (HHV) were systematically investigated. At 350 °C and 60 bar, 20 wt% Co/AC showed the highest liquid yield (70.46 wt%) along with HHV of 34.22 MJ/Kg. Among the tested bimetallic catalysts, comparable liquid yield (68.85 wt%) and HHV (34.16 MJ/kg) were achieved with 20 wt% 4Co-1Fe/AC catalyst. Methyl phenol derivatives were found to be the main component in upgraded bio-oil. The carbon number of the upgraded bio-oil was mainly distributed in C5–C11 fraction, especially with the C8 component (20.40 wt%). The catalysts were deactivated by the formation of carbonaceous compounds on the external surface, oxidation of metal species, and blocking of active sites on catalysts.

The rich data from the genome-wide association studies (GWAS) and phenome-wide association studies (PheWAS) offer an unprecedented opportunity to identify the biological underpinnings of age-related disease (ARD) risk and multimorbidity. Surprisingly, however, a comprehensive list of ARDs remains unavailable due to the lack of a clear definition and selection criteria. We developed a method to identify ARDs and to provide a compendium of ARDs for genetic association studies. Querying 1,358 electronic medical record-derived traits, we first defined ARDs and age-related traits (ARTs) based on their prevalence profiles, requiring a unimodal distribution that shows an increasing prevalence after the age of 40 years, and which reaches a maximum peak at 60 years of age or later. As a result, we identified a list of 463 ARDs and ARTs in the GWAS and PheWAS catalogs. We next translated the ARDs and ARTs to their respective 276 Medical Subject Headings diseases and 45 anatomy terms. The most abundant disease categories are neoplasms (48 terms), cardiovascular diseases (44 terms), and nervous system diseases (27 terms). Employing data from a human symptoms-disease network, we found 6 symptom-shared disease groups, representing cancers, heart diseases, brain diseases, joint diseases, eye diseases, and mixed diseases. Lastly, by overlaying our ARD and ART list with genetic correlation data from the UK Biobank, we found 54 phenotypes in 2 clusters with high genetic correlations. Our compendium of ARD and ART is a highly useful resource, with broad applicability for studies of the genetics of aging, ARD, and multimorbidity.

Type 1 diabetes (T1D) is an organ-specific autoimmune disease, whereby immune cell-mediated killing leads to loss of the insulin-producing β cells in the pancreas. Genome-wide association studies (GWAS) have identified over 200 genetic variants associated with risk for T1D. The majority of the GWAS risk variants reside in the non-coding regions of the genome, suggesting that gene regulatory changes substantially contribute to T1D. However, identification of causal regulatory variants associated with T1D risk and their affected genes is challenging due to incomplete knowledge of non-coding regulatory elements and the cellular states and processes in which they function. Here, we performed a comprehensive integrated post-GWAS analysis of T1D to identify functional regulatory variants in enhancers and their cognate target genes. Starting with 1,817 candidate T1D SNPs defined from the GWAS catalog and LDlink databases, we conducted functional annotation analysis using genomic data from various public databases. These include 1) Roadmap Epigenomics, ENCODE, and RegulomeDB for epigenome data; 2) GTEx for tissue-specific gene expression and expression quantitative trait loci data; and 3) lncRNASNP2 for long non-coding RNA data. Our results indicated a prevalent enhancer-based immune dysregulation in T1D pathogenesis. We identified 26 high-probability causal enhancer SNPs associated with T1D, and 64 predicted target genes. The majority of the target genes play major roles in antigen presentation and immune response and are regulated through complex transcriptional regulatory circuits, including those in HLA (6p21) and non-HLA (16p11.2) loci. These candidate causal enhancer SNPs are supported by strong evidence and warrant functional follow-up studies.

To perform the permanent disposal of metal hydroxide waste from electro-kinetic decontamination, it is necessary to secure the technology for its solidification. The integrity tests on the fabricated solidification should also meet the criteria of the Korea Radioactive Waste Agency. We carried out the solidification of metal hydroxide waste using cement solidification. The integrity tests such as the compressive strength, immersion, leach, and irradiation tests on the fabricated cement solidifications were performed. It was also confirmed that these requirements of the criteria of Korea Radioactive Waste Agency on these cement solidifications were met. The microstructures of all the cement solidifications were analyzed and discussed.

Great amounts of solid radioactive waste (second waste) and waste solution are generated from the remediation of uranium-contaminated soil. To reduce these, we investigated washing with a less acidic solution and recycling the waste solution after removal of the dominant elements and uranium. Increasing the pH of the washing solution from 0.5 to 1.5 would be beneficial in terms of economics. A high content of calcium in the waste solution was precipitated by adding sulfuric acid. The second waste can be significantly reduced by using sorption and desorption techniques on ampholyte resin S-950 prior to the precipitation of uranium at pH 3.0.

Ulmus davidiana has been used as food or medicine in oriental due to its safety, including its roots, bark, and fruits. The roots and bark of Ulmus were used as a diuretic and for treatment due to their anti-cancer, antioxidant, and anti-inflammatory effects. Ulmus species are known to contain flavan-3-ols as their main component. In previous research the presence of (+)-catechin 5-O-β-D-apiofuranoside was isolated from the roots of Ulmus davidiana, and (+)-catechin 7-O-β-D-xylopyranoside was confirmed in the bark Ulmus Americana, and the presence of catechin 7-O-β-D apiofuranoside in the stems and bark of Ulmus davidiana var. japonica. The catechin-glycosides of flavan-3-ols have various effects, including antiulcer properties, and have also been used as analgesics. Additionally, chemotaxonomy studies of the Ulmus species have been reported. However, the chemotaxonomy of Ulmus species native to Asia has not been reported. In this study, we report the screening of catechin 7-O-beta-D apiofuranoside from various Ulmus species native to Asia. We confirmed the presence of catechin 7-O-β-D-apiofuranoside in a total of 22 Ulmus samples, including 18 Ulmus species native to China, and 1 sample each from Mongolian, Nicaragua, Vietnam, and Korea through HPLC and LC-MS/MS analysis. We also confirmed the content of the indicator materials. Therefore, the potential of using native Ulmus species from Korea as a natural material has been confirmed.

Pyrolysis is an environmental friendly alternative method compared with incineration, and the least time-consuming and smallest infrastructure footprint method compared with bio-chemical and thermo-chemical conversion. Baseline data for the pyrolysis of food waste was obtained in a kinetic study of the thermal decompositions by thermogravimetric analysis. To simulate the difference in the types of food waste, the study was done using model compounds, such as cereals, meat, vegetable, and mixed food waste; the pyrolysis commenced at 150 °C for most food waste and the process terminated at 450 °C to 500 °C. Between one and three peaks were observed on a differential thermogravimetry (DTG) graph, depending on the type of waste being pyrolyzed, reflecting the difference in the time required for pyrolysis of different components of food waste to take place. Depending on the composition of each food, one or four peaks were found, and the pyrolysis patterns of carbohydrate, protein, fat, and cellulose were found. Activation energies and frequency factors were calculated from the rates of conversion, using differential equation analyses. The activation energy increased from 10 kJ/mol to 50 kJ/mol as conversions increased from the 10% to 90%, regardless of the food waste type. The activation energy was measured as 50 kJ/mol, with a slight variation among the type of the food waste. Due to the activation energy being low, food waste consists of carbohydrates and other substances rather than cellulose, hemicellulose, and lignin.

It is allegedly known that the thermal stability of the Mint Lift® (the Mint Lift® 17 and the Mint Lift® Fine; HansBiomed Co., Ltd., Seoul, Korea) over time might be lower as compared with thread-lifts processed through ultrasonic molding technology, such as the MEDI ROPE (WSM 19-03; CNG Co., Ltd., Gyeonggi, Korea), because the Mint Lift® undergoes a thermal treatment during the manufacturing process. We conducted this accelerated aging test to compare the thermal stability over time between the Mint Lift® and the MEDI ROPE. Thus, we measured the degrees of strength of the MEDI ROPE, the Mint Lift® 17, and the Mint Lift® Fine at 0, 2, 3, 4, 5, 7, 8, 9, 10, 11, 14, and 17 weeks. Between 0 and 14 weeks, the Mint Lift® 17 and the Mint Lift® Fine had significantly higher degrees of strength as compared with the MEDI ROPE (p < 0.05). At 0, 5, and 10 weeks, the Mint Lift® 17 and the Mint Lift® Fine showed no notable differences in microscopic findings as compared with the MEDI ROPE. At 20 weeks, however, the integrities of the Mint Lift® 17 and the Mint Lift® Fine were better preserved as compared with the MEDI ROPE. In conclusion, our results indicate that the Mint Lift® 17 and the Mint Lift® Fine might be less vulnerable to degradation over time as compared with the MEDI ROPE under thermal conditions.

Background and objectives: We conducted this preliminary retrospective study to assess the short-term safety of silicone gel-filled breast implants (SGBIs) that are commercially available in Korean women. Materials and methods :The current retrospective, observational study was conducted in a total of 2612 patients (n = 2612) who underwent augmentation mammaplasty using breast implants at our hospitals between 1 January 2017 and 31 August 2021. Results: Overall, there were a total of 248 cases (9.49%) of postoperative complications; these include 112 cases of early seroma, 52 cases of shape deformation, 32 cases of CC, 12 cases of early hematoma, 12 cases of rupture, 12 cases of infection, 12 cases of stretch deformities with skin excess and 4 cases of rippling. Overall complication-free survival of the breast implant was estimated at 1564.32 ± 75.52 days (95% CI 1416.39–1712.32). Then, the Motiva Ergonomix™ SilkSurface showed the longest survival (1528.00 ± 157.92 days [95% CI 1218.48–1837.56]), followed by the BellaGel® SmoothFine (1458.4 ± 65.76 days [95% CI 1329.56–1587.28]), the Sebbin® Sublimity (1322.00 ± 51.20 days [95% CI 1221.64–1422.32]), the BellaGel® Smooth (1138.72 ± 161.28 days [95% CI 822.6–1454.84), the Mentor® MemoryGel™ Xtra (698.4 ± 52.64 days [95% CI 595.28–801.52]) and the Natrelle® INSPIRA™ (380.00 ± 170.88 days [95% CI 45.04–714.96]) in the decreasing order. On subgroup analysis, both the Motiva ErgonomixTM and Mentor® MemoryGel™ Xtra showed no postoperative complications. However, the BellaGel® SmoothFine, Sebbin® Sublimity and BellaGel® Smooth showed incidences of 8.87%, 4.84% and 1.61%, respectively. A subgroup analysis also showed differences in incidences of postoperative complications between microtextured and smooth breast implants (15.18% vs. 16.67%). Conclusions: In conclusion, our results indicate that diverse types of an SGBI are commercially available and their safety profile varies according to the manufacturer. Plastic surgeons should consider the safety profile of each device in selecting the optimal types of the device for Korean women who are in need of an implant-based augmentation mammaplasty. However, this warrants a single-surgeon, single-center study with long periods of follow-up.

Chronic intradiploic organizing hematoma of the skull is a rare lesion that usually presents as a progressively growing mass after head trauma, thus making it difficult to diagnose. To date, only nine cases that have been histopathologically confirmed as organizing hematoma of the skull have been reported in the literature. Herein, we describe a case of a chronic organizing hematoma involving the right parietal bone, presenting as a slowly growing mass in a 54-year-old man. The lesion was also visualized on magnetic resonance imaging (MRI) with a zero echo time sequence. In this case report, we emphasize that chronic intradiploic organizing hematoma should be considered in the differential diagnosis of a palpable scalp mass. We also highlight the importance of meticulous radiological review in the context of appropriate clinical suspicion and the usefulness of the zero TE sequence in evaluating calvarial lesions.

Abstract A hole‐type vertical structure is adopted to fabricate a vertically stacked resistive switching random access memory (ReRAM) array. The vertical configuration is more advantageous in lowering the process cost and increasing integration density than the horizontal configuration. However, the memory cells constituting the hole‐type vertical‐ReRAM (V‐ReRAM) array can be short‐circuited if a middle electrode is introduced to stack a rectifying element onto the memory layer. Thus, a self‐rectifying Pt/Ta2O5/Al‐doped HfO2/TiN ReRAM is adopted in this study to prevent the sneak‐current and short‐circuit issues for efficient operation in vertical crossbar array configuration. A two‐ or three‐layer stacked V‐ReRAM is fabricated, and its electrical characteristics are evaluated. High switching uniformity and sufficiently large memory window and rectification ratio are acquired. The low operation power and high switching uniformity render this V‐ReRAM array suitable for high‐capacity storage devices. However, the on‐state data retention needs improvement. Detailed investigation of the three‐layer stacked device identifies that lateral charge spreading between neighboring cells in the V‐ReRAM causes such a problem, which can be mitigated by increasing the intercell distance.

In infants and young children, bedtime problems and night waking are common and the main presentations of insomnia. Poor sleep may critically impact the daytime functioning and mood of the child and their caregivers. A comprehensive sleep history, a sleep diary/log, and the BEARS (Bedtime problems, Excessive daytime sleepiness, Awakenings during the night, Regularity and duration of sleep, and Sleep-disordered breathing) sleep screen are useful for diagnosing sleep problems in young children. Behavioral therapies for this type of insomnia include extinction, bedtime fading with positive routines, and scheduled awakening. Previous studies of behavioral interventions for young children showed significant improvements in sleep-onset latency, night waking frequency, and night waking duration. Parent education about their child’s sleep, bedtime routines, and sleep hygiene is essential for treatment.

Abstract In South Korea where the tuberculosis (TB) burden is intermediate, the risk of in-hospital transmission of TB remains high. We conducted a retrospective cohort study of 244 inpatients diagnosed with pulmonary TB (2015–2018) to evaluate the impact of the Xpert MTB/RIF assay (Xpert) screening on timely isolation. TB screening was performed with smear microscopy and a polymerase chain reaction test, and the Xpert was additionally used from November 2016. Among all patients with pulmonary TB, the median time-to-isolation was significantly reduced (22.6 vs. 69.7 h; p

Hepatic artery pseudoaneurysm is a rare but potentially life-threatening condition that usually occurs after trauma. Early recognition and prompt management are essential for preventing catastrophic consequences, such as hemoperitoneum. We report a rare case of liver abscess caused by Klebsiella oxytoca resulting in hepatic artery pseudoaneurysm without iatrogenic injury. The unique feature of the present case is that the abscess cavity itself became a pseudoaneurysm as a result of fistula formation with the hepatic artery. Vascular complications should be considered in patients with unfavorable clinical course even in the absence of iatrogenic injury. Endovascular treatment is safe and effective.

Background Intracranial artery dissection (IAD) may be an underdiagnosed cause of large vessel occlusion. The safety and efficacy of intra-arterial therapy (IAT) in patients with IAD are largely unknown. We report the case of a patient with IAD who was successfully treated with IAT. Case Report A 27-year-old man with a sudden-onset sensory dominant aphasia was admitted to our hospital around 16 hours after disease onset. Brain magnetic resonance angiography revealed an occlusion in the left distal middle cerebral artery (MCA). On the susceptibility-weighted imaging, bead-shaped dark signals were observed in the left MCA bifurcation, and intramural hematoma was suspected. We performed thrombectomy and permanent stenting for the dissecting MCA occlusion and achieved complete recanalization. Conclusion The IMH on susceptibility-weighted imaging led us to suspect that the large vessel occlusion was due to the IAD. Further research is needed to address the efficacy and safety of IAT in patients with IAD.

Chest computed tomography demonstrated a suspected primary tumor in the upper sternal body of a 48‐year‐old woman who presented with sternal pain. After being diagnosed with chondrosarcoma, she underwent sternal resection. Subsequent chest wall reconstruction was performed after careful planning using a bone cement block made of polypropylene mesh and polymethylmethacrylate. The block was fixed to the manubrium and ribs using the SternaLock System. She was discharged following an uneventful postoperative recovery, and is currently undergoing follow‐up.

Extramedullary myeloma refers to the presence of myeloma deposits outside the skeletal system and typically indicates a poor prognosis associated with shorter overall survival and progression-free survival. We report a case of extramedullary myeloma with extensive, abdominal multi-organ involvement mimicking lymphoma at initial diagnosis. Bulky retroperitoneal masses with severe diffusion restriction and patency of encased vessels can be MR findings of both myeloma and lymphoma. Radiologic findings such as arterial hyperenhancement, obstructive uropathy, and the lack of associated lymphadenopathy may favor a diagnosis of myeloma over lymphoma.

Teaching point: A fibroepithelial polyp is an intraluminal, long, slender neoplasm that frequently occurs in the ureteropelvic junction and upper ureter.

Teaching Point: The typical imaging features of a retroperitoneal solitary fibrous tumor are relatively large-sized, have a well-defined margin, an avidly heterogeneous enhancement on arterial phase, a prolonged enhancement on delayed phase, and serpentine vessels along the periphery of the tumor.

Recanalization of a completely occluded vertebral artery, which involves ruptured vertebral dissecting aneurysm, to a normal configuration is rare. Here we report the case of a recanalized vertebral artery dissecting aneurysm in a 51-year-old woman that was treated using endovascular trapping and the right vertebral artery was completely occluded. Six months after the procedure, transfemoral cerebral artery angiography showed a normal configuration of the antegrade recanalized vertebral artery. We also suggest three possible mechanisms for the phenomenon of antegrade recanalization, of which we consider the water-hammer effect mechanism to be the most probable. Endovascular trapping, regardless of the presence of a true or false lumen, is capable of providing promising results and good prognosis through antegrade revascularization or complete occlusion. Keywords: Recanalization, Vertebral artery dissecting aneurysm, Endovascular trapping, Aneurysmal Subarachnoid Hemorrhage

Teaching Point: The typical CT finding of internal supravesical hernia is a herniated and dilated bowel loop beneath a compressed urinary bladder.

Herein, a feasible method is provided for circuit implementation of the convolutional neural network (CNN) in neuromorphic hardware using the multiple layers‐stacked resistance switching random access memory (ReRAM). The specific ReRAM is accompanied by self‐rectification functionality. The single‐input multiple‐output (SIMO) scheme is an optimum method in the extraction of the features of a letter with a versatile selection of the intended features, whereas the multiple‐input single‐output (MISO) scheme provides a highly efficient method to extract the features from the color image, which is composed of several component color images. The Pt/HfO2−x/TiN‐based self‐rectification ReRAM that is integrated into the sidewalls of the two‐layer structure provides a sound framework for the circuit implementation of the SIMO and MISO schemes. The appropriate selection of the kernels for image compression and feature extraction greatly facilitates the CNN in neuromorphic hardware.

Peritoneal carcinomatosis (PC) indicates the metastasis of a malignant neoplasm to the peritoneal surface. PC can be incidentally detected before discovery of the primary malignancy during an imaging study. There are other conditions that can mimic PC, such as pseudomyxoma peritonei, peritoneal lymphomatosis, peritoneal malignant mesothelioma, leiomyomatosis peritonealis disseminata, and tuberculous peritonitis. These diseases may appear similar on computed tomography (CT), but there are some clues for the differential diagnosis. This article will describe the CT findings of PC and its mimics for the differential diagnosis.

Main teaching point: The typical imaging feature of intravascular leiomyosarcoma is a heterogeneous enhancing mass within an expanded vessel.

Main teaching point: Mucinous rectal adenocarcinoma typically shows high signal intensity on T2-weighted images, weak enhancement, and internal calcification.

Main teaching point: Right paraduodenal hernia typically occurs in the fossa of Waldeyer, with the herniated bowel sac located posterior to the right colic artery and vein.

Main teaching point: Typical imaging features of pancreatic acinar cell carcinoma are relatively large, with a well-defined margin, exophytic growth, and heterogeneous enhancement

Congenital anomalies and anatomic variants of the pancreas are various and not uncommon. Recent advances in imaging modalities and their increasing accessibility have led increased opportunity to detect anomalies and variants of the pancreas. It is important to recognize pancreatic anomalies because, if they cause symptoms, they can be fixed. In addition, the presence of anatomic variants can affect surgical or interventional planning, and they can also cause unexpected post-operative complications. In this essay, we review the embryogenesis of the pancreas and describe imaging findings of various congenital anomalies and anatomic variants in the pancreas.

Ductal adenocarcinoma is the most common pancreatic neoplasm. A variety of pancreatic lesions mimic pancreas ductal adenocarcinoma (PDAC), such as high-grade neuroendocrine tumors, small solid pseudopapillary tumors, metastases, focal autoimmune pancreatitis, and groove pancreatitis. These occasionally look similar in images, but they have differential diagnosis points. Familiarity with the imaging features of PDAC and its mimics is paramount for correct diagnosis and management of patients. In this essay, we describe imaging findings of PDAC and its mimics for differential diagnosis.

Painful legs and moving toes (PLMT) syndrome is characterized by spontaneous movements of the digits and pain in one or both lower extremities. Of the reported cases, a majority of the patients was female, and the mean age of onset was 58 years. Only one pediatric case has been reported so far. Herein, we report the first adolescent case of PLMT in Korea. A 16-year-old girl complained of tingling pain in the left leg and involuntary movement of the ipsilateral great toe one month after a second untethering surgery. Three years ago, she had undergone untethering surgery to correct lipomeningomyelocele at the S2 level of the conus medullaris. At that time, she was diagnosed with polyradiculopathy at the left L5 level with axonal involvement. We diagnosed her with PLMT syndrome and prescribed gabapentin. Her symptoms diminished within a day. Complete relief from involuntary movement of the toe was achieved within four months. PLMT is a rare syndrome but it should be considered in the differential diagnosis of children and adolescents with limb pain and spontaneous movement in their toes.

An 18-year-old boy was admitted with chest discomfort, nausea, and dyspnea at rest. At the age of 3 years, he underwent muscle biopsy and dystrophin gene analysis owing to an enlarged calf muscle and elevated serum kinase level (6,378 U/L) without overt weakness; based on the results, Becker muscular dystrophy (BMD) was diagnosed. The dystrophin gene showed deletion of exons 45 to 49. He remained ambulant and could step upstairs without significant difficulties. A chest roentgenogram showed cardiomegaly (cardiothoracic ratio, 54%), and his electrocardiogram (ECG) showed abnormal ST-T wave, biatrial enlargement, and left ventricular hypertrophy. The 2-dimensional and M-mode ECGs showed a severely dilated left ventricular cavity with diffuse hypokinesis. The systolic indices were reduced, including fractional shortening (9%) and ejection fraction (19%). Despite receiving intensive medical treatment, he died from congestive heart failure 5 months after the initial cardiac symptoms. We report a case of BMD with early-onset dilated cardiomyopathy associated with deletion of exons 45 to 49. Early cardiomyopathy can occur in BMD patients with certain genotypes; therefore, careful follow-up is required even in patients with mild phenotypes of BMD.

BackgroundNeostigmine augments clindamycin-induced neuromuscular block and antagonizes rocuronium-induced neuromuscular block; however, it remains unclear whether neostigmine enhances the neuromuscular blocking (NMB) that is caused by combinations of rocuronium and clindamycin. The intent of this study was to determine whether neostigmine potentiates the muscle relaxation that is induced by combinations of rocuronium and clindamycin and to estimate whether both clindamycin and rocuronium have synergistic actions on NMB.MethodsForty-one left phrenic nerve-hemidiaphragms (from male Sprague-Dawley rats, 150-250 g) were mounted in Krebs solution. Three consecutive single twitches (ST, 0.1 Hz) and one tetanic tension (50 Hz for 1.9 s) were obtained for each increase in concentration of rocuronium or clindamycin. The concentrations of rocuronium were cumulatively increased until an 80% to 90% reduction in ST was attained in the Krebs solutions pre-treated with 0 (n = 5), 0.1 (n = 1), 0.25 (n = 1), 0.5 (n = 4), or 1.0 (n = 1) mM clindamycin or with 0 (n = 4), 0.1 (n = 1), 0.5 (n = 5), 1.0 (n = 5), or 2.0 (n = 4) mM clindamycin in combination with 250 nM neostigmine, and so were the concentrations of clindamycin in the Krebs solutions pre-treated with 0 (n = 6) or 250 nM (n = 6) neostigmine.ResultsClindamycin increased the potency of rocuronium for ST and tetanic fade, irrespective of the presence of neostigmine. Neostigmine shifted the concentration-response curve of rocuronium to the right in the presence or absence of clindamycin. The interaction between rocuronium and clindamycin was synergistic when clindamycin concentrations were in excess of 0.5 mM, irrespective of the presence of neostigmine.ConclusionsNeostigmine may partially antagonize the neuromuscular block that is induced by a combination of clindamycin and rocuronium. Clinicians are advised to be aware that clindamycin synergistically increases the degree of rocuronium-induced neuromuscular block, even when neostigmine is present.