Methylosinus trichosporium OB3b bioaugmentation unleashes polyhydroxybutyrate-accumulating potential in waste-activated sludge.

BACKGROUND: Wastewater treatment plants contribute approximately 6% of anthropogenic methane emissions. Methanotrophs, capable of converting methane into polyhydroxybutyrate (PHB), offer a promising solution for utilizing methane as a carbon source, using activated sludge as a seed culture for PHB production. However, maintaining and enriching PHB-accumulating methanotrophic communities poses challenges. RESULTS: This study investigated the potential of Methylosinus trichosporium OB3b to bioaugment PHB-accumulating methanotrophic consortium within activated sludge to enhance PHB production. Waste-activated sludges with varying ratios of M. trichosporium OB3b (1:0, 1:1, 1:4, and 0:1) were cultivated. The results revealed substantial growth and methane consumption in waste-activated sludge with M. trichosporium OB3b-amended cultures, particularly in a 1:1 ratio. Enhanced PHB accumulation, reaching 37.1% in the same ratio culture, indicates the dominance of Type II methanotrophs. Quantification of methanotrophs by digital polymerase chain reaction showed gradual increases in Type II methanotrophs, correlating with increased PHB production. However, while initial bioaugmentation of M. trichosporium OB3b was observed, its presence decreased in subsequent cycles, indicating the dominance of other Type II methanotrophs. Microbial community analysis highlighted the successful enrichment of Type II methanotrophs-dominated cultures due to the addition of M. trichosporium OB3b, outcompeting Type I methanotrophs. Methylocystis and Methylophilus spp. were the most abundant in M. trichosporium OB3b-amended cultures. CONCLUSIONS: Bioaugmentation strategies, leveraging M. trichosporium OB3b could significantly enhance PHB production and foster the enrichment of PHB-accumulating methanotrophs in activated sludge. These findings contribute to integrating PHB production in wastewater treatment plants, providing a sustainable solution for resource recovery.

Disorders of hyperpigmentation. Part II. Review of management and treatment options for hyperpigmentation.

Key challenges in the management of pigmentary disorders such as melasma and postinflammatory hyperpigmentation are their resistance to treatment, tendency to recur after treatment, and the risk of exacerbating hyperpigmentation with many treatment modalities. The second article in this 2-part continuing medical education series on pigmentary disorders focuses on the evidence behind medical and procedural treatments of dyschromias, including photoprotection, topical lightening agents, oral agents, chemical peels, and laser therapy.

Disorders of hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders.

Disorders of hyperpigmentation are common and, depending on the extent and location of involvement, can affect the quality of life and pose a significant psychologic burden for patients. Given the similarities in presentation of the various causes of hyperpigmentation, it is often difficult to elucidate the etiology of these conditions, which is important to guide management. Furthermore, certain disorders, such as lichen planus pigmentosus and ashy dermatosis, have similar clinical and/or histologic presentations, and their classification as distinct entities has been debated upon, leading to additional confusion. In this review, the authors selected commonly encountered disorders of hyperpigmentation of the skin, subdivided into epidermal, dermal, or mixed epidermal-dermal disorders based on the location of pigment deposition, along with disorders of hyperpigmentation of the mucosa and nails. Melanocytic nevi, genetic disorders, and systemic causes of hyperpigmentation were largely excluded and considered to be outside the scope of this review. We discussed the pathogenesis of hyperpigmentation as well as the clinical and histologic features of these conditions, along with challenges encountered in their diagnosis and classification. The second article in this 2-part continuing medical education series focuses on the medical and procedural treatments of hyperpigmentation.

Augmented Reality-Based Visual Cue for Guiding Central Catheter Insertion in Pediatric Oncologic Patients.

BACKGROUND: Pediatric hemato-oncologic patients require central catheters for chemotherapy, and the junction of the superior vena cava and right atrium is considered the ideal location for catheter tips. Skin landmarks or fluoroscopic supports have been applied to identify the cavoatrial junction; however, none has been recognized as the gold standard. Therefore, we aim to develop a safe and accurate technique using augmented reality technology for the location of the cavoatrial junction in pediatric hemato-oncologic patients. METHODS: Fifteen oncology patients who underwent chest computed tomography were enrolled for Hickman catheter or chemoport insertion. With the aid of augmented reality technology, three-dimensional models of the internal jugular veins, external jugular veins, subclavian veins, superior vena cava, and right atrium were constructed. On inserting the central vein catheters, the cavoatrial junction identified using the three-dimensional models were marked on the body surface, the tip was positioned at the corresponding location, and the actual insertion location was confirmed using a portable x-ray machine. The proposed method was evaluated by comparing the distance from the cavoatrial junction to the augmented reality location with that to the conventional location on x-ray. RESULTS: The mean distance between the cavoatrial junction and augmented reality location on x-ray was 1.2 cm, which was significantly shorter than that between the cavoatrial junction and conventional location (1.9 cm; P = 0.027). CONCLUSIONS: Central catheter insertion using augmented reality technology is more safe and accurate than that using conventional methods and can be performed at no additional cost in oncology patients.

The value of photomedicine in a global health crisis: Utilizing ultraviolet C to decontaminate N95 respirators during the COVID-19 pandemic.

One early problem during the height of the COVID-19 global pandemic, caused by severe acute respiratory syndrome 2 (SARS-CoV-2), was the shortage of personal protective equipment donned by healthcare workers, particularly N95 respirators. Given the known virucidal, bactericidal, and fungicidal properties of ultraviolet irradiation, in particular ultraviolet C (UVC) radiation, our photomedicine and photobiology unit explored the role of ultraviolet germicidal irradiation (UVGI) using UVC in effectively decontaminating N95 respirators. The review highlights the important role of photobiology and photomedicine in this pandemic. Namely, the goals of this review were to highlight: UVGI as a method of respirator disinfection-specifically against SARS-CoV-2, adverse reactions to UVC and precautions to protect against exposure, other methods of decontamination of respirators, and the importance of respirator fit testing.

Impact of hospital size on the outcomes of appendectomy in children: an analysis of a comprehensive nationwide pediatric dataset.

PURPOSES: The purpose of this study was to investigate the outcomes after appendectomy in children according to hospital size. METHODS: The records of 11,565 patients with the diagnosis-related group code for appendectomy were extracted from HIRA-Pediatric Patient Sample from 2012 to 2016. The number of hospital visits and the length of stay in hospital within 30 days after appendectomy were analyzed. RESULTS: Patients who were treated at large-sized hospitals were more likely to be younger, more likely to reside in metropolitan areas, and tended to receive laparoscopic surgery. The number of hospital visits within 30 days in patients managed by medium- and large-sized hospitals decreased in comparison to small-sized hospitals. The length of hospital stay in large-sized hospitals was decreased in comparison to small- and medium-sized hospitals. A subgroup analysis revealed that complicated appendectomy did not have a significant impact on the difference in the length of hospital stay between hospital sizes. CONCLUSION: The number of hospital visits and the length of hospital stay was higher in small-sized hospitals in comparison to large-sized hospitals. Appendectomy performed in the larger hospital showed better outcomes in pediatric patients. We recommend that pediatric surgical procedures be performed in large hospitals, and that proper incentives be given for procedures to be performed by pediatric specialists.

Retrospective single-center study evaluating clinical and dermoscopic features of longitudinal melanonychia, ABCDEF criteria, and risk of malignancy.

BACKGROUND: Longitudinal melanonychia (LM) is a common finding in clinical practice; however, it has a broad differential diagnosis, including subungual melanoma (SUM), which can be difficult to distinguish clinically from benign conditions. OBJECTIVE: To identify clinical and dermoscopic features that distinguish histopathologically diagnosed SUM from benign LM and to evaluate the validity of the ABCDEF criteria among patients on whom a biopsy was performed. METHODS: Retrospective cohort study of consecutive patients who underwent nail matrix biopsy for LM at a single center from January 2011 to November 2017. RESULTS: A total of 84 cases in which biopsy was performed (8 cases of SUM and 76 benign) were included in the analysis. The patients with SUM were younger (P = .011), had their melanonychia longer (P = .017), and presented with a wider band (P = .002) and greater width percentage (P < .001) than patients with benign LM did. The number of ABCDEF criteria met did not differ between the groups. LIMITATIONS: Retrospective single-center study; patients who did not undergo biopsy could not be studied. CONCLUSIONS: In the cases of LM in which biopsy was performed, SUM usually presented with a wider band and greater width percentage than benign LM did. The number of ABCDEF criteria met was not different between the groups. Because many of the clinical and dermoscopic signs were less consistent, biopsy should be performed in cases with any concerning band, especially in those with width percentage higher than 40%.

Subungual Leiyomyoma Presenting as Erythronychia: Case Report and Review of the Literature

We report a rare case of leiomyoma of the fingernail in a 59-year-old woman. She presented with red discoloration, lifting, and distal splitting of her left 2nd fingernail for several months. She reported sensitivity at baseline which became more painful in the cold. Histopathology sections from the nail matrix biopsy specimen showed a dermal proliferation of bland appearing spindle shaped cells with elongated, blunt ended nuclei (SMA and caldesmon positive), arranged in fascicles, which is typical of leiomyomas. Interestingly, our patient had a history of uterine leiomyoma, requiring hysterectomy. To our knowledge, this case is the first report in which a subungual leiomyoma is associated with another leiomyoma in the same patient. J Drugs Dermatol. 2019;18(5):465-467.

A 3D printed esophageal atresia-tracheoesophageal fistula thorascopy simulator for young surgeons.

We developed a 3D-printed thoracoscopic surgery simulator for esophageal atresia with tracheoesophageal fistula (EA-TEF) and assessed its effectiveness in educating young pediatric surgeons. Prototype production and modifications were repeated five times before producing the 3-D printed final product based on a patient's preoperative chest computed tomography. A 24-item survey was used to rate the simulator, adapted from a previous report, with 16 young surgeons with an average of 6.2 years of experience in pediatric surgery for validation. Reusable parts of the thoracic cage were printed to combine with replaceable parts. Each structure was fabricated using diverse printing materials, and subsequently affixed to a frame. In evaluating the simulator, the scores for each factor were 4.33, 4.33, 4.27, 4.31, 4.63, and 4.75 out of 5, respectively, with the highest ratings in value and relevance. The global rating was 3.38 out of 4, with ten stating that it could be used with slight improvements. The most common comment from participants was that the esophageal anastomosis was close to the actual EA-TEF surgery. The 3D-printed thoracoscopic EA-TEF surgery simulator was developed and reflected the actual surgical environment. It could become an effective method of training young pediatric surgeons.

Attenuation of esophageal anastomotic stricture through remote ischemic conditioning in a rat model.

Anastomotic stricture is a typical complication of esophageal atresia surgery. Remote ischemic conditioning (RIC) has demonstrated multiorgan benefits, however, its efficacy in the esophagus remains unclear. This study aimed to investigate whether applying RIC after esophageal resection and anastomosis in rats could attenuate esophageal stricture and improve inflammation. Sixty-five male Sprague-Dawley rats were categorized into the following groups: controls with no surgery, resection and anastomosis only, resection and anastomosis with RIC once, and resection and anastomosis with RIC twice. RIC included three cycles of hind-limb ischemia followed by reperfusion. Inflammatory markers associated with the interleukin 6/Janus kinase/ signal transducer and activator of transcription 3 (IL-6/JAK/STAT3) and tumor necrosis factor-alpha/nuclear factor-κB (TNF-α/NF-kB) signaling pathways were evaluated with RNA and protein works. The RIC groups showed significantly lower stricture rates, lower inflammatory markers levels than the resection and anastomosis-only group. The RIC groups had significantly lower IL-6 and TNFa levels than the resection and anastomosis-only group, confirming the inhibitory role of remote ischemic conditioning in the IL-6/JAK/STAT3 and TNF-α/NF-kB signaling pathways. RIC after esophageal resection and anastomosis can reduce the inflammatory response, improving strictures at the esophageal anastomosis site, to be a novel noninvasive intervention for reducing esophageal anastomotic strictures.

Robotic surgeries in pediatric patients: an early experience in a single center.

Purpose: Robotic surgery (RS) has the advantages of 3-dimensional view, optical magnification, motional scaling, and improved ergonomics and degree of freedom. Although RS has widely been performed on pediatric patients lately, there are still numerous restrictions and ambiguous indications. The purpose of this study was to report our early experience with RS on pediatric patients at a single center. Methods: Electronic medical records of patients who underwent RS with the da Vinci Xi surgical platform (Intuitive Surgical, Inc.) in Seoul National University Children Hospital from November 2019 to August 2021 were reviewed retrospectively. The median follow-up was 21.0 months (range, 12.3-31.8 months). An online survey was conducted to investigate satisfaction with robotic surgical scars. Results: Fifty-four patients underwent robotic surgeries (median age at operation, 11.1 years [range, 0.1-17.8 years]). In our hospital, patients had 20 different kinds of robotic surgeries, including choledochal cyst excision with hepaticojejunostomy, ovarian mass excision, and others. Median operation time and console time were 157.5 minutes (range, 45-505 minutes) and 40 minutes (range, 11-360 minutes), respectively. All cases were done without conversion into open or laparoscopic methods. Postoperative complications were found in 5 patients. According to an online survey, over half of patients (60.9%) answered that they felt satisfied with scars. Conclusion: Our early experience demonstrated the safety and feasibility of RS in children with a range of diagnoses and complicated procedures. With more experience, RS could be an alternative to traditional open or laparoscopic operations in pediatric patients. Further studies are needed to clarify indications of pediatric RS.

Cervical spondylotic myelopathy caused by violent motor tics in a child with Tourette syndrome.

INTRODUCTION: We report a case of a 9-year-old boy with Tourette syndrome (TS) who developed progressive quadriparesis that was more severe in the upper extremities. CASE REPORT: He had experienced frequent and violent motor tics consisting of hyperflexion and hyperextension for years. Magnetic resonance imaging (MRI) revealed a focal high-signal intensity cord lesion and adjacent cervical spondylotic changes. Initially, the patient was observed for several months because of diagnostic uncertainty; his neurological status had improved and later worsened again. Anterior cervical discectomy of C3-4 and fusion immediately followed by posterior fixation were performed. After surgery, the neck collar was applied for 6 months. His neurological signs and symptoms improved dramatically. TS with violent neck motion may cause cervical spondylotic myelopathy at an early age. CONCLUSIONS: The optimal management is still unclear and attempts to control tics should be paramount. Circumferential fusion with neck bracing represents a viable treatment option.

Continuous cultivation of mixed-culture microalgae using anaerobic digestion effluent in photobioreactors with different strategies for adjusting nitrogen loading rate.

This study examined continuous mixed-culture microalgae cultivation for nutrient removal from anaerobic digestion (AD) effluents in photobioreactors, while altering the NH4+-N loading rate (NLR) by adjusting either the hydraulic retention time (HRT) (reactor set RH) or the influent NH4+-N concentration (reactor set RS). Both RH and RS demonstrated efficient nutrient removal and microalgae cultivation at NLRs of 4-10 mg NH4+-N/L∙d, reaching peak performance at 10 mg NH4+-N/L∙d. Within this range, RH obtained greater biomass yield and productivity, while RS maintained higher microalgal concentrations. The cultivated biomasses obtained from RH and RS had good settleability and suitable fatty acid compositions as a biodiesel feedstock, although their organic composition varied considerably with NLR and HRT. Parachlorella overwhelmingly dominated the reactors' microalgal communities throughout the experiment, co-existing with various microalgae-associated bacteria. Changes in NLR significantly influenced the bacterial community structures, underscoring its critical role in determining reactor performance and microalgal-bacterial community behavior.

Application of additional three-dimensional materials for education in pediatric anatomy.

We conducted this study to investigate the effects of additional education using 3D visualization (3DV) and 3D printing (3DP) after applying 2D images for anatomical education in normal pediatric structures and congenital anomalies. For the production of 3DV and 3DP of the anatomical structures, computed tomography (CT) images of the four topics (the normal upper/lower abdomen, choledochal cyst, and imperforate anus) were used. Anatomical self-education and tests were administered to a total of 15 third-year medical students with these modules. Following the tests, surveys were conducted in order to evaluate satisfaction from students. In all four topics, there were significant increases in the test results with additional education with 3DV after initial self-study with CT (P < 0.05). The difference in scores was highest for the imperforate anus when 3DV supplemented the self-education. In the survey on the teaching modules, the overall satisfaction scores for 3DV and 3DP were 4.3 and 4.0 out of 5, respectively. When 3DV was added to pediatric abdominal anatomical education, we found an enhancement in understanding of normal structures and congenital anomalies. We can expect the application of 3D materials to become more widely used in anatomical education in various fields.