Identifying factors related to delayed neck metastasis after surgical treatment in patients with oral squamous cell carcinoma.

BACKGROUND: General treatment of oral squamous cell carcinoma (OSCC) is surgical treatment with or without neck dissection. Although the incidence of delayed neck metastasis is rare, it may occur after the surgery and is known to be the most important factor in the prognosis. The purpose of is study is to evaluate the clinical and histopathological factors associated with delayed neck metastasis case among patients. METHODS: A total of 195 patients who underwent surgical treatment for OSCC from 2016 to 2022 were investigated. Among them, delayed neck metastasis (DNM) was analyzed. The criterion for delayed neck metastasis was a newly developed neck lesion after the primary operation without neck dissection in cN0 necks. To identify the correlation between prognostic factors and the incidence of delayed neck metastasis, χ2 analysis with phi correlation and Cramer's V test was performed. Cumulative survival rates (CRS) were compared between the groups with the incidence of DNM and without DNM. Also, the log rank test for CSR and Cox proportional hazard model was analyzed to estimate the significance of the CSR and confirm the correlations between prognostic factors and DNM. RESULT: Among 195 patients, 14 were discovered to have DNM. The primary tumor locations were the tongue (n = 5), floor of the mouth (n = 2), mandibular gingiva (n = 1), maxillary gingiva (n = 4), retromolartrigone (n = 1), and buccal mucosa (n = 2) each. The cases consisted of TNM stage I (n = 1), stage II (n = 3), stage III (n = 3), and stage IV (n = 8), respectively. The result of the χ2 analysis identified a correlation between positive neck (p = 0.01), depth of invasion (p = 0.09), radiation therapy (p = 0.003), and DNM. Groups without DNM showed better prognosis compared to groups with DNM. Regarding positive neck, depth of invasion, and radiation therapy, only depth of invasion showed significance in CSR analysis. CONCLUSION: DNM after surgical treatment of OSCC is a rare event, and few were found in a review of the literature. Also, many prognostic factors have been suggested but controversial. However, in our study, some prognostic factors have been identified to have a significant correlation with the incidence of DNM, and analysis of such factors provides important information predicting neck metastasis and the prognosis.

Prognostic factors of oral squamous cell carcinoma: the importance of recurrence and pTNM stage.

BACKGROUND: Oral squamous cell carcinoma has a poor prognosis. Therefore, prognostic factors are important to increase the survival rate. This study assessed the survival rate and the prognostic factors for survival of patients with oral squamous cell carcinoma. METHOD: This study included 168 patients who underwent surgery for oral squamous cell carcinoma between January 2006 and December 2021. The survival rate was analyzed with overall survival and disease-specific survival. The patient's age, sex, pTNM stage, primary sites (lip, tongue, mouth of floor, mandibular gingiva, maxillary gingiva, mandibular vestibule, maxillary vestibule, retromolar trigone, palate, buccal mucosa, primary intra-osseous site), smoking and alcohol drinking habits, depth of invasion, perineural and lymphovascular invasion, cell differentiation, and postoperative radiotherapy were evaluated to analyze risk factors. Kaplan-Meier methods were used to estimate the survival rates. Cox regression methods were used to investigate the main independent predictors of survival in univariable and multivariable analysis. RESULTS: Sixty-eight patients died of oral squamous cell carcinoma during follow-up periods. Their overall survival for 5 years was 51.2%, and the disease-specific survival was 59.2%. In univariable analysis, seven factors which are neck metastasis, depth of invasion, cell differentiation, lymphovascular invasion, postoperative radiotherapy, pTNM stage, and recurrence were significantly associated with survival. In multivariable analysis, pTNM stage and recurrence were significantly associated with survival. CONCLUSION: In patients with oral squamous cell carcinoma, pTNM stage and recurrence were significant prognostic factors. Neck metastasis, depth of invasion, cell differentiation, lymphovascular invasion, and postoperative radiotherapy were also prognostic factors. These factors serve as markers for obtaining prognosis information in oral squamous cell carcinoma.

Radiological features of Stafne mandibular bone cavity in panoramic image and cone beam computed tomography.

BACKGROUND: Stafne mandibular bone cavity (SMBC) is an asymptomatic radiolucent lesion observed in the mandible on X-ray images, with well-defined borders. This lesion does not require treatment, and size changes are very rare. The purpose of this article is to summarize the radiological and clinical features of SMBC, aiming to prevent misinterpretation of this benign lesion as other pathologies and aid in differential diagnosis within the field of dental practice. METHODS: A total of 32 patients who visited our hospital and were radiologically diagnosed with SMBC based on cone-beam computed tomography (CBCT) and panoramic images between 2005 and 2021 were included in this study. Among them, surgical intervention was performed in one case. Gender and age distribution of the patients, radiographic location and size of the lesion, relationship with the mandibular canal in CBCT, presence of cortical bone erosion in the mandibular lingual area in panoramic images, and the amount of residual cortical bone on the affected side in CBCT were investigated. RESULT: Patients were 26 men (81.3%) and 6 women, with a mean age of 54.3 years. The average horizontal and vertical length was 16.6 mm and 10.6 mm. Out of a total of 32 cases, 29 cases were found in the posterior region of the mandibular body, while 3 cases were in the angle of the mandible. Lesions located below the mandibular canal were observed in 29 cases, while lesions involving the mandibular canal were present in 3 cases. Erosion of the mandibular lingual cortical bone was observed in 11 cases (34.4%), while 21 cases (65.6%) showed no erosion on panoramic images. Among the total of 14 cases (43.8%) where the cortical bone on the affected side was invaded, the average residual cortical bone thickness was 1.1 mm. CONCLUSION: SMBC is a benign lesion primarily found in the mandibular angle and posterior body of the mandible. In most cases, treatment is not necessary, and differentiation from other lesions can be achieved by understanding its clinical characteristics and features on panoramic radiographs and CBCT.

Customized three-dimensional printed ceramic bone grafts for osseous defects: a prospective randomized study.

Ridge resorption can result in insufficient bone volume for implant surgery, necessitating bone substitutes to restore the resorption area. Recent advances in computer-aided design and manufacturing enable the use of alloplastic bone graft materials with customizable compositions or shapes. This randomized study evaluated the clinical effectiveness of a customized three-dimensional (3D) printed alloplastic bone material. Sixty patients requiring guided bone regeneration for implant installation following tooth extraction due to alveolar bone resorption were recruited at two institutions. The participants were randomly allocated to either a group that received 3D-printed patient-customized bone graft material or a group that received conventional block bone graft material. Implant installation with bone harvesting was performed approximately 5 months after bone grafting. Histological and radiological assessments of the harvested bone area were performed. The experimental group had a significantly higher percent bone volume and a smaller tissue surface than the control group. Bone volume, bone surface, bone surface/volume ratio, bone surface density (bone surface/total volume), and bone mineral density did not differ significantly between groups. Patient-customized bone graft materials offer convenience and reduce patient discomfort. The findings suggest 3D-printed patient-customized bone graft materials could be used as an alternative for simpler bone grafting procedures.

Spontaneous intracranial hypotension presenting with bilateral subdural hematoma: Decision-making and treatment strategies.

BACKGROUND: The timing and decision to drain subdural hematoma (SDH) in spontaneous intracranial hypotension (SIH) remains a dilemma. We reviewed our experience of bilateral SDH secondary to SIH, focusing on decision making and treatment strategies. METHODS: We retrospectively reviewed bilateral SDH secondary to SIH between March 2010 and September 2021. Baseline characteristics of patients, diagnosis, radiologic findings, treatments, and clinical outcome were investigated. RESULTS: Fifteen patients (7 men, 8 women) with bilateral SDH secondary to SIH were included in this study. Initially, patients were treated conservatively (4 patients, 26.7 %), with an epidural blood patch (EBP, 3 patients, 20.0 %), and SDH drainage followed by the Trendelenburg position (8 patients, 53.3 %). All 3 patients that were initially treated with EBP required SDH drainage. Of the 8 patients initially treated with SDH drainage via burr hole followed by Trendelenburg position, 7 patients showed sustained improvements without EBP; however, 1 patient needed EBP. Deterioration to coma occurred in 6 out of 15 patients (40.0 %). All 6 deteriorated patients immediately recovered after SDH drainage with Trendelenburg position; 5 achieved sustained improvement without EBP and 1 required EBP. During the follow-up period, 14 out of 15 patients (93.3 %) showed good recovery. CONCLUSIONS: Evacuation of SDH is not always necessary in SIH; however, we did not hesitate to perform hematoma drainage, in deteriorated patients or those with thick hematoma that is associated with significant sagging and cistern effacement. This can prevent irreversible neurologic complications. Moreover, the Trendelenburg position may help to achieve sustained improvement without additional treatment.

Spontaneous Acute Epidural Hematoma Associated With Metastatic Hepatocellular Carcinoma: A Case Report.

Spontaneous acute epidural hematoma (AEDH) co-occurring with metastatic hepatocellular carcinoma (HCC) of the skull is rare, with only 7 documented cases in existing literature. This report describes the case of a 42-year-old man who presented with decreased consciousness following intermittent headaches following minor head trauma. Computed tomography imaging revealed an AEDH, prompting surgical intervention. Despite preliminary assumptions linking the causes of the trauma, surgical exploration revealed no evidence of traumatic injury. Instead, an infiltrative soft-tissue mass within the skull was identified. Histopathological examination confirmed that the mass was a metastatic HCC. Despite the successful hematoma evacuation, the patient's neurological status did not improve. This case underscores the importance of considering metastatic disease in the differential diagnosis of AEDH, particularly in patients with a history of malignant tumors, irrespective of prior indications of bone metastasis. Furthermore, it emphasizes the need to enhance diagnostic and therapeutic strategies for such complex cases.

Considerations for intensity modulated total body or total marrow and lymphoid irradiation.

We compiled a sampling of the treatment techniques of intensity-modulated total body irradiation, total marrow irradiation and total marrow and lymphoid irradiation utilized by several centers across North America and Europe. This manuscript does not serve as a consensus guideline, but rather is meant to serve as a convenient reference for centers that are considering starting an intensity-modulated program.

Lesch-Nyhan syndrome: a case report.

Lesch-Nyhan syndrome (LNS) is a rare X-linked recessive disorder caused by a mutation in the hypoxanthine phosphoribosyltransferase 1 (HPRT1) gene. This syndrome is characterized by excessive production of uric acid, mental retardation, self-mutilation, choreoathetosis, and spasticity. The most distinctive symptom is compulsive self-mutilation. For patients with LNS, different methods have been tried to reduce self-biting behaviors including restraints, behavioral treatment, medications, deep brain stimulation, tooth extraction and botulinum toxin A injection. In this report, we present a case of LNS undergoing cheiloplasty due to self-mutilation and tooth extraction of the left deciduous maxillary canine.

Development of Nano-Sized Copper-Deposited Antimicrobial Air Filters Using a Mixed Melt-Blown Process.

Air purification devices, such as air purifiers, provide fresh air by filtering out airborne pollutants, dust, and other harmful substances using various filter systems. While air filters are generally effective in filtering pollutants such as dust, they encounter a challenge when filtering harmful microorganisms such as mites, bacteria, mold, and viruses. These microorganisms, which are present in public transport and public indoor spaces, tend to proliferate on the surface of the filter media, eventually reintroducing themselves into the air or causing unpleasant odors. To address this issue, herein, copper particles were prepared as one masterbatch and deposited on polypropylene (PP) pellets through plasma vacuum deposition to effectively filter dust and microorganisms and prevent their growth on the surface of the filter media. After adding 3-10 wt.% of the masterbatch to conventional PP pellets to fabricate a filter media, the distribution of copper on the surface of the filter media was observed through a scanning electron microscope. To verify the safety and effectiveness of the antimicrobial material, the filter media containing antimicrobial particles was tested using Escherichia coli (E. coli) and Staphylococcus aureus through a filter emission test.

Clinical Practice Guidelines for Oropharyngeal Dysphagia.

OBJECTIVE: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one's physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. METHODS: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. RESULTS: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. CONCLUSION: This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Accurate measurements of particle emissions from a three-dimensional printer using a chamber test with a mixer-installed sampling system.

Recently, three-dimensional (3D) printing has attracted attention as a new manufacturing technology. However, there is lack of data and regulations regarding the emissions of ultrafine particles from 3D printers. Therefore, we investigated particle emissions from a 3D printer using a chamber system. The test system was improved by installing a developed mixer for accurate measurement. Without a mixer, the particle concentration was unstable depending on the sampling point; however, reliable data with good uniformity were obtained by installing a mixer. Using the test system with a mixer, we investigated particle emissions from a 3D printer during operation. Filaments made each of acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) were used as the printing material. The effects of nozzle temperature and printing time were investigated. Compared to the effect of the printing time, the nozzle temperature had greater impact on the particle emissions. The dominant particle size for the emissions from a 3D printer is less than 10 nm, and the particle concentration decreased with increasing particle size.

Associated systemic diseases and etiologies of medication-related osteonecrosis of the jaw: a retrospective study of 265 surgical cases.

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) is one of the complications caused by various drugs. As there are increasing reports of MRONJ, it is important to diagnose and identify patients who have the potential risk of the disease. The aim of this study was to analyze the systemic diseases, etiology, and treatment results of MRONJ. MATERIAL AND METHODS: A total of 265 MRONJ operations were reviewed retrospectively. This study included patients who were diagnosed as MRONJ and those who also received surgery, ranging from simple extraction to reconstruction with free flaps, from 2009 to 2021. Each patient's systemic disease and eitology and basic demographic information was taken into consideration. RESULTS: The most common diseases related were osteoporosis (n = 127), breast cancer (n = 77), multiple myeloma (n = 27), prostate cancer (n = 26), and etc. (n = 12). The related causes of MRONJ were extraction (n = 138), implants (n = 40), and irritations by prosthesis (n = 29); however, 55 cases were occurred spontaneously. Out of 265 patients, 214 were women while 51 were men. The average age when the surgery took place was 67.7 and 69.8 years for male and female patients, respectively. Saucerization and sequestrectomy (n = 252) was the most common surgical treatment, followed by mandibulectomy (n = 12) and partial maxillectomy (n = 1). While 4 cases occurred in both jaws, 168 cases were in the mandible and 93 cases were in the maxilla. CONCLUSION: Nearly 50 % of the MRONJ patients had osteoporosis and the other patients who received bone targeting agents parentral had bone metastasis of various cancers. Extraction is the most common related event for MRONJ.

Minimal dose of hematopoietic stem cell transplantation without myelosuppressive conditioning for T-B+NK- severe combined immunodeficiency.

We reviewed the medical records of five patients with T-B+NK- severe combined immunodeficiency (SCID) who received minimal dose allogeneic hematopoietic cell transplantation (HCT) (total nucleated cell count (TNC) lower than 1.0 × 108/kg). Patients were administered a median of 5.0 mL of bone marrow or peripheral blood without conditioning (in four) or with anti-thymocyte globulin alone (in one). Three patients received HCT from a matched sibling donor, one from unrelated donor, and one from familial mismatched donor. The median TNC and CD34+ cells were 0.54 (0.29-0.84) × 108/kg and 0.61 (0.35-0.84) × 106/kg, respectively. Engraftment was achieved in all. Total T cell, CD4+ cell, and CD8+ cell recovery was obtained within a year in four, and immunoglobulin replacement was discontinued in all. All patients survived, exhibiting stable donor chimerism. We obtained sufficient therapeutic effects with minimal dose transplantation without intensive conditioning in patients with T-B+NK- SCID.

Features of Odontogenic Sinusitis Associated With Dental Implants.

OBJECTIVES: With the increase in dental implants for tooth loss, odontogenic sinusitis following maxillary dental implants is frequently encountered in otorhinolaryngology practice. The authors aimed to reveal the association between implant extrusion into maxillary sinus, along with implant-related complications in patients diagnosed with implant-related odontogenic sinusitis (IR-ODS). STUDY DESIGN: Case-control study. METHODS: This study enrolled 60 patients who received functional endoscopic sinus surgery due to IR-ODS. The preoperative sinus computed tomography was retrospectively reviewed. Among the 120 maxillary sinuses of the 60 patients, 68 sides were diagnosed with IR-ODS sides, whereas 27 sides showed no clinical or radiological evidence of this condition after the implant insertion and were defined as the control sides. Statistical analysis between these two groups was conducted, in addition to odds ratio (OR) calculations for associations with IR-ODS. RESULTS: The mean age of the IR-ODS subjects was 59.5 ± 19.1, with a male to female ratio of 32/28 (53.3%/46.7%). Implants extruding by more than 4 mm into the maxillary sinus, peri-implantitis, bone graft disruption-extrusion were associated with a significantly higher incidence in the IR-ODS (p = 0.035, p = 0.003, p = 0.011, respectively). The IR-ODS sides showed an adjusted-OR (95% confidence interval) of 27.4 (2.7-276.5) for extrusion length >4 mm, 11.8 (3.0-46.5) for peri-implantitis, and 34.1 (3.3-347.8) for bone graft disruption (p = 0.005, p < 0.001, and p = 0.003, respectively). CONCLUSION: Maxillary dental implants extruding more than 4 mm into the maxillary sinus, peri-implantitis, and disrupted-extruded bone grafts show significant association with IR-ODS. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:237-243, 2023.

Case report: Fulminant extraneural metastasis of glioblastoma through venous sinus.

Background: Extraneural metastasis (ENM) of glioblastoma are rare. However, as patient overall survival improves, the incidence of ENM has gradually increased. Although several risk factors have been proposed, venous sinus invasion was regarded as a very exceptional route for ENM. Case description: We report a 60-year-old man with glioblastoma in the temporal lobe, invading the transverse and sigmoid venous sinus. After gross total tumor resection, the patient received the standard chemoradiation therapy. Systemic evaluation for persistent shoulder and back pain revealed widespread metastasis to lymph nodes and multiple bones 9 months after surgery. Despite spine radiation therapy, the patient became paraplegic and died 1 year after surgery. Conclusions: Venous sinus invasion should be kept in mind by physicians, as a risk factor for glioblastoma ENM. Systemic evaluation of these patients with extracranial symptoms should be performed without hesitation.

Impact of respiratory motion on lung dose during total marrow irradiation.

We evaluated the impact of respiratory motion on the lung dose during linac-based intensity-modulated total marrow irradiation (IMTMI) using two different approaches: (1) measurement of doses within the lungs of an anthropomorphic phantom using thermoluminescent detectors (TLDs) and (2) treatment delivery measurements using ArcCHECK where gamma passing rates (GPRs) and the mean lung doses were calculated and compared with and without motion. In the first approach, respiratory motions were simulated using a programmable motion platform by using typical published peak-to-peak motion amplitudes of 5, 8, and 12 mm in the craniocaudal (CC) direction, denoted here as M1, M2, and M3, respectively, with 2 mm in both anteroposterior (AP) and lateral (LAT) directions. TLDs were placed in five selected locations in the lungs of a RANDO phantom. Average TLD measurements obtained with motion were normalized to those obtained with static phantom delivery. The mean dose ratios were 1.01 (0.98-1.03), 1.04 (1.01-1.09), and 1.08 (1.04-1.12) for respiratory motions M1, M2, and M3, respectively. To determine the impact of directional respiratory motion, we repeated the experiment with 5-, 8-, and 12-mm motion in the CC direction only. The differences in average TLD doses were less than 1% when compared with the M1, M2, and M3 motions indicating a minimal impact from CC motion on lung dose during IMTMI. In the second experimental approach, we evaluated extreme respiratory motion 15 mm excursion in only the CC direction. We placed an ArcCHECK device on a commercial motion platform and delivered the clinical IMTMI plans of five patients. We compared, with and without motion, the dose volume histograms (DVHs) and mean lung dose calculated with the ArcCHECK-3DVH tool as well as GPR with 3%, 5%, and 10% dose agreements and a 3-mm constant distance to agreement (DTA). GPR differed by 11.1 ± 2.1%, 3.8 ± 1.5%, and 0.1 ± 0.2% with dose agreement criteria of 3%, 5%, and 10%, respectively. This indicates that respiratory motion impacts dose distribution in small and isolated parts of the lungs. More importantly, the impact of respiratory motion on the mean lung dose, a critical indicator for toxicity in IMTMI, was not statistically significant (p > 0.05) based on the Student's t-test. We conclude that most patients treated with IMTMI will have negligible dose uncertainty due to respiratory motion. This is particularly reassuring as lung toxicity is the main concern for future IMTMI dose escalation studies.

Knowledge-based planning for multi-isocenter VMAT total marrow irradiation.

Purpose: Total marrow irradiation (TMI) involves optimization of extremely large target volumes and requires extensive clinical experience and time for both treatment planning and delivery. Although volumetric modulated arc therapy (VMAT) achieves substantial reduction in treatment delivery time, planning process still presents a challenge due to use of multiple isocenters and multiple overlapping arcs. We developed and evaluated a knowledge-based planning (KBP) model for VMAT-TMI to address these clinical challenges. Methods: Fifty-one patients previously treated in our clinic were selected for the model training, while 22 patients from another clinic were used as a test set. All plans used a 3-isocenter to cover sub-target volumes of head and neck (HN), chest, and pelvis. Chest plan was performed first and then used as the base dose for both the HN and pelvis plans to reduce hot spots around the field junctions. This resulted in a wide range of dose-volume histograms (DVH). To address this, plans without the base-dose plan were optimized and added to the library to train the model. Results: KBP achieved our clinical goals (95% of PTV receives 100% of Rx) in a single day, which used to take 4-6 days of effort without KBP. Statistically significant reductions with KBP were observed in the mean dose values to brain, lungs, oral cavity and lenses. KBP substantially improved 105% dose spillage (14.1% ± 2.4% vs 31.8% ± 3.8%), conformity index (1.51 ± 0.06 vs 1.81 ± 0.12) and homogeneity index (1.25 ± 0.02 vs 1.33 ± 0.03). Conclusions: KBP improved dosimetric performance with uniform quality. It reduced dependence on planner experience and achieved a factor of 5 reduction in planning time to produce quality plans to allow its wide-spread clinical implementation.

The effect of FK506 (tacrolimus) loaded with collagen membrane and fibrin glue on promotion of nerve regeneration in a rat sciatic nerve traction injury model.

BACKGROUND: Peripheral nerve injury is one of the most common injuries that might occur in oral and maxillofacial surgery. The purpose of this study was to determine the effect of FK506 loaded with collagen membrane and fibrin glue on the promotion of nerve regeneration after traction nerve injury in a rat model. METHODS: Thirty male Sprague-Dawley rats were divided into three groups: group A (n = 10), a sham group whose sciatic nerve was exposed without any injury; and groups B (n = 10) and C (n = 10), which underwent traction nerve injury using 200 g of traction force for 1 min. The injured nerve in group C was covered with a collagen membrane soaked with FK506 (0.5 mg/0.1 mL) and fibrin glue. Functional analysis and microscopic evaluation were performed at 2 and 4 weeks after injury. RESULTS: The sciatic function index was - 5.78 ± 3.07 for group A, - 20.69 ± 5.22 for group B, and - 12.01 ± 4.20 for group C at 2 weeks after injury. However, at 4 weeks, the sciatic function index was - 5.58 ± 2.45 for group A, - 19.69 ± 4.81 for group B, and - 11.95 ± 1.94 for group C. In both periods, statistically significant differences were found among the groups (p<0.017). Histomorphometric evaluation revealed improved nerve regeneration in group C compared to that in group B. However, no statistical differences in axonal density were found among the three groups (p < 0.017). CONCLUSION: Localized FK506 with collagen membrane and fibrin glue could promote axonal regeneration in a rat model of traction nerve injury.

Needs for Increased Awareness of Gastrointestinal Manifestations in Patients With Human Inborn Errors of Immunity.

The gastrointestinal (GI) tract is frequently affected by inborn errors of immunity (IEI), and GI manifestations can be present in IEI patients before a diagnosis is confirmed. We aimed to investigate clinical features, endoscopic and histopathologic findings in IEI patients. This was a retrospective cohort study conducted from 1995 to 2020. Eligible patients were diagnosed with IEI and had GI manifestations that were enough to require endoscopies. IEI was classified according to the International Union of Immunological Societies classification. Of 165 patients with IEI, 55 (33.3%) had GI manifestations, and 19 (11.5%) underwent endoscopy. Among those 19 patients, nine (47.4%) initially presented with GI manifestations. Thirteen patients (68.4%) were male, and the mean age of patients 11.5 ± 7.9 years (range, 0.6 - 26.6) when they were consulted and evaluated with endoscopy. The most common type of IEI with severe GI symptoms was "Disease of immune dysregulation" (31.6%) followed by "Phagocyte defects" (26.3%), according to the International Union of Immunological Societies classification criteria. Patients had variable GI symptoms such as chronic diarrhea (68.4%), hematochezia (36.8%), abdominal pain (31.6%), perianal disease (10.5%), and recurrent oral ulcers (10.5%). During the follow-up period, three patients developed GI tract neoplasms (early gastric carcinoma, mucosa associated lymphoid tissue lymphoma of colon, and colonic tubular adenoma, 15.8%), and 12 patients (63.2%) were diagnosed with inflammatory bowel disease (IBD)-like colitis. Investigating immunodeficiency in patients with atypical GI symptoms can provide an opportunity for correct diagnosis and appropriate disease-specific therapy. Gastroenterologists and immunologists should consider endoscopy when atypical GI manifestations appear in IEI patients to determine if IBD-like colitis or neoplasms including premalignant and malignant lesions have developed. Also, if physicians in various fields are better educated about IEI-specific complications, early diagnosis and disease-specific treatment for IEI will be made possible.

Estimate of the critical exposure time based on 70 confirmed COVID-19 cases.

The transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs via contact with contaminated surfaces and inhalation of large airborne droplets and aerosols. As growing evidence of airborne SARS-CoV-2 transmission has been reported worldwide, ventilation is an effective method of reducing the infection probability of SARS-CoV-2. This leads to such questions as "What is a sufficient ventilation rate for avoiding the risk of COVID-19 infection?" Therefore, this study evaluates the critical ventilation rates according to room size and exposure time when a susceptible person is in the same room as an infector. The analytical results were based on data obtained from 70 confirmed COVID-19 cases transmitted in confined spaces without an operational ventilation system. The results reveal that even with active ventilation (20 h-1 air exchange rate), the critical exposure time for a susceptible person with a COVID-19 infector in a small space of 20 m3 is less than 1 h. For other cases (different space sizes), the estimated air exchange rates for avoiding the risk of infection are generally higher than various requirements for good indoor air quality. The findings of this study will provide guidelines for determining sufficient ventilation rates to protect against the highly contagious COVID-19.