Predictors of membrane oxygenator failure in pediatric extracorporeal membrane oxygenation.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is increasingly utilized in pediatric patients. Failure to recognize membrane oxygenator failure can lead to critical complications due to rapid deterioration of membrane oxygenator function. Therefore, identifying the predictors for membrane oxygenator exchange is crucial. However, risk factors for membrane oxygenator exchange in pediatric V-A ECMO remain unclear; therefore, this study aimed to evaluate these risk factors. METHODS: This retrospective cohort study enrolled all pediatric patients aged <18 years who received V-A ECMO between August 2018 and July 2023 at a tertiary-care pediatric hospital in Japan. The Cox proportional hazards model was used to evaluate the predictors of membrane oxygenator failure within 72 h after initiation. RESULTS: During the study period, membrane oxygenator failure occurred in 18/55 (32.7%) children within 72 h; membrane oxygenator failure within 72 h occurred in 4/29 (13.8%) and 14/26 (53.8%) in the groups with ratio of blood flow divided by the blood flow limit of the membrane oxygenator (B/L) of <0.5 and ≥0.5, respectively (adjusted hazards ratio, 4.97 [95% confidence interval, 1.33-18.5]; p = 0.017). After adjusting for delta pressure of the oxygenator, an increase in body weight and aspartate aminotransferase levels were associated with an increase in early membrane oxygenator failure. CONCLUSIONS: This retrospective study demonstrated that a B/L ratio >0.5, an increase in body weight, and elevated aspartate aminotransferase were independent risk factors for early membrane oxygenator failure in pediatric V-A ECMO. However, a prospective multicenter study with an appropriate sample size is warranted to mitigate potential bias, and enhance generalizability for further investigation of the association between a B/L ratio and early membrane oxygenator failure.

Melting temperature mapping method in children: Rapid identification of pathogenic microbes.

INTRODUCTION: The melting temperature (Tm) mapping method (TM) identifies bacterial species by intrinsic patterns of Tm values in the 16S ribosomal RNA gene (16S rDNA) extracted directly from whole blood. We examined potential clinical application of TM in children with bloodstream infection (BSI). METHODS: This was a prospective observational study at a children's hospital in Japan from 2018 to 2021. In patients with diagnosed or suspected BSI, we investigated the match rates of pathogenic bacteria identified by TM and blood culture (BC), the inspection time to identification of TM, and the amount of bacterial DNA in blood samples. RESULTS: The median age of 81 patients (93 samples) was 3.6 years. Of 23 samples identified by TM, 11 samples matched the bacterial species with BC (positive-match rate, 48 %). Of 64 TM-negative samples, 62 samples were negative for BC (negative-match rate, 97 %). Six samples, including one containing two pathogenic bacterial species, were not suitable for TM identification. In total, the matched samples were 73 of 93 samples (match rate, 78 %). There were seven samples identified by TM in BC-negative samples from blood collected after antibiotic therapy. Interestingly, the bacteria were matched with BC before antibiotic administration. These TM samples contained as many 16S rDNA copies as the BC-positive samples. The median inspection time to identification using TM was 4.7 h. CONCLUSIONS: In children with BSI, TM had high negative-match rates with BC, the potential to identify the pathogenic bacteria even in patients on antibiotic therapy, and more rapid identification compared to BC. REGISTERING CLINICAL TRIALS: UMIN000041359https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000047220.

Middle meatus microbiome in patients with eosinophilic chronic rhinosinusitis in a Japanese population.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease and is subdivided into eosinophilic and noneosinophilic forms. There are few reports investigating the nasal microbiome and its pathological functions in patients with CRS. OBJECTIVE: We sought to analyze factors contributing to variations of the nasal microbiome in CRS, and on the basis of these factors, to elucidate whether the bacterial metabolites were related to the pathogenesis. METHODS: Nasal swabs were collected, and the V3 to V4 variable region of the 16S ribosomal RNA gene was amplified and sequenced. Factors contributing to variations of the nasal microbiome in patients with CRS were compared. The most influential factor was whether CRS was eosinophilic, and we compared α- and ß-diversity, bacterial species, and predictive bacterial functions between the 2 patient groups. In addition, the metabolites of the key bacteria were extracted, and we evaluated the predicted bacterial functions in airway epithelial cells. RESULTS: In total, 110 patients with CRS and 33 control subjects were enrolled. On the basis of the factors of variation, it was found that patients with eosinophilic CRS (n = 65) had different microbiomes with weighted UniFrac ß-diversity and lower α-diversity compared with those with noneosinophilic CRS (n = 45). A higher abundance of Fusobacterium nucleatum and an increased LPS pathway were observed in patients with noneosinophilic CRS compared with those with eosinophilic CRS. In airway epithelial cells, LPS derived from F nucleatum suppressed the expression levels of ALOX15 induced by TH2 cytokines. CONCLUSIONS: The differences in the nasal microbiome may play a key role in the pathophysiology of CRS.

Factors associated with viral RNA shedding and evaluation of potential viral infectivity at returning to school in influenza outpatients after treatment with baloxavir marboxil and neuraminidase inhibitors during 2013/2014-2019/2020 seasons in Japan: an observational study.

BACKGROUND: This study assessed the differences in daily virus reduction and the residual infectivity after the recommended home stay period in Japan in patients infected with influenza and treated with baloxavir (BA), laninamivir (LA), oseltamivir (OS), and zanamivir (ZA). METHODS: We conducted an observational study on children and adults at 13 outpatient clinics in 11 prefectures in Japan during seven influenza seasons from 2013/2014 to 2019/2020. Virus samples were collected twice from influenza rapid test-positive patients at the first and second visit 4-5 days after the start of treatment. The viral RNA shedding was quantified using quantitative RT-PCR. Neuraminidase (NA) and polymerase acidic (PA) variant viruses that reduce susceptibility to NA inhibitors and BA, respectively, were screened using RT-PCR and genetic sequencing. Daily estimated viral reduction was evaluated using univariate and multivariate analyses for the factors such as age, treatment, vaccination status, or the emergence of PA or NA variants. The potential infectivity of the viral RNA shedding at the second visit samples was determined using the Receiver Operator Curve based on the positivity of virus isolation. RESULTS: Among 518 patients, 465 (80.0%) and 116 (20.0%) were infected with influenza A (189 with BA, 58 with LA, 181 with OS, 37 with ZA) and influenza B (39 with BA, 10 with LA, 52 with OS, 15 with ZA). The emergence of 21 PA variants in influenza A was detected after BA treatment, but NA variants were not detected after NAIs treatment. Multiple linear regression analysis showed that the daily viral RNA shedding reduction in patients was slower in the two NAIs (OS and LA) than in BA, influenza B infection, aged 0-5 years, or the emergence of PA variants. The residual viral RNA shedding potentially infectious was detected in approximately 10-30% of the patients aged 6-18 years after five days of onset. CONCLUSIONS: Viral clearance differed by age, type of influenza, choice of treatment, and susceptibility to BA. Additionally, the recommended homestay period in Japan seemed insufficient, but reduced viral spread to some extent since most school-age patients became non-infectious after 5 days of onset.

Precordial Doppler to assess vascular access in children: A preliminary report.

BACKGROUND: Delayed identification and dysfunction of peripheral intravenous (PIV) infiltration can lead to serious injury in children. This preliminary study aimed to describe the application of precordial Doppler ultrasound to detect and confirm the correct PIV access in children with congenital heart disease (CHD). METHODS: This study was conducted on children (<18 years) diagnosed with CHD and admitted to the pediatric intensive care unit (PICU) of a single center after cardiac surgery or cardiac catheterization between February 2020 and May 2021. Three raters judged the precordial Doppler sound change (S test) after injection of 0.5 mL/kg of normal saline (NS) through the PIV access. Blood-flow velocities before and after the NS injection were recorded and the accuracy of detecting PIV catheter infiltration and dysfunction was analyzed (V test). RESULTS: The overall incidence of PIV infiltration and dysfunction was in 3 out of 103 patients (2.9%). The sensitivity, specificity, positive and negative likelihood ratios, and area under the receiver operating characteristic curve were 3 out of 3 [100%, 95% confidence interval (CI): 29.2-100], 86 out of 100 (86%, 95% CI: 77.6%-92.1), 7.1, 0.0, and 0.93, respectively, in the S test and they were 2 out of 3 (66.7%, 95% CI: 9.4%-99.2), 94 out of 100 (94.0%, 95% CI: 87.4%-7.8%), 11.1, 0.36, and 0.80, respectively in the V test. CONCLUSIONS: Precordial Doppler ultrasound was a feasible and accurate technique for confirming correct PIV access in children with CHD; however, a larger, prospective investigation is necessary to examine its diagnostic accuracy.

Early introduction of very small amounts of multiple foods to infants: A randomized trial.

BACKGROUND: We investigated whether multiple food allergies could be safely prevented by simultaneously administering very small amounts of multiple foods. METHODS: Infants 3-4 months old with atopic dermatitis from 14 primary care pediatric clinics in Japan were enrolled in this randomized, placebo-controlled trial. The infants were administered either mixed allergenic food powder (MP) containing egg, milk, wheat, soybean, buckwheat, and peanuts, or placebo powder (PP). The amount of powder was increased in a stepwise manner on weeks 2 and 4, and continued until week 12. The occurrence of food allergy episodes after powder intervention was assessed at 18 months old. This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (number UMIN000027837). RESULTS: A total of 163 participants were randomly allocated to either the MP group (n = 83) or the PP group (n = 80). The incidence of food allergy episodes by 18 months was significantly different between the MP and PP groups (7/83 vs. 19/80, respectively; risk ratio 0.301 [95% CI 0.116-0.784]; P = 0.0066). Egg allergies were reduced in the MP group. In addition, food allergy episodes from any of the other five foods were significantly reduced, although the reductions in those due to individual foods were not significant. CONCLUSIONS: Gradually increasing the intake of very small amounts of multiple foods in early infancy can safely reduce the incidence of egg allergies. Other foods may also suppress food allergies, but no definitive conclusions could be reached.

Neutrophils interact with cholangiocytes to cause cholestatic changes in alcoholic hepatitis.

BACKGROUND & OBJECTIVES: Alcoholic hepatitis (AH) is a common but life-threatening disease with limited treatment options. It is thought to result from hepatocellular damage, but the presence of cholestasis worsens prognosis, so we examined whether bile ducts participate in the pathogenesis of this disease. DESIGN: Cholangiocytes derived from human bile ducts were co-cultured with neutrophils from patients with AH or controls. Loss of type 3 inositol 1,4,5-trisphosphate receptor (ITPR3), an apical intracellular calcium channel necessary for cholangiocyte secretion, was used to reflect cholestatic changes. Neutrophils in contact with bile ducts were quantified in liver biopsies from patients with AH and controls and correlated with clinical and pathological findings. RESULTS: Liver biopsies from patients with AH revealed neutrophils in contact with bile ducts, which correlated with biochemical and histological parameters of cholestasis. Cholangiocytes co-cultured with neutrophils lost ITPR3, and neutrophils from patients with AH were more potent than control neutrophils. Biochemical and histological findings were recapitulated in an AH animal model. Loss of ITPR3 was attenuated by neutrophils in which surface membrane proteins were removed. RNA-seq analysis implicated integrin ß1 (ITGB1) in neutrophil-cholangiocyte interactions and interference with ITGB1 on cholangiocytes blocked the ability of neutrophils to reduce cholangiocyte ITPR3 expression. Cell adhesion molecules on neutrophils interacted with ITGB1 to trigger RAC1-induced JNK activation, causing a c-Jun-mediated decrease in ITPR3 in cholangiocytes. CONCLUSIONS: Neutrophils bind to ITGB1 on cholangiocytes to contribute to cholestasis in AH. This previously unrecognised role for cholangiocytes in this disease alters our understanding of its pathogenesis and identifies new therapeutic targets.

Population Pharmacokinetics and Pharmacodynamics of Meropenem in Critically Ill Pediatric Patients.

This study investigates the optimal meropenem (MEM) dosing regimen for critically ill pediatric patients, for which there is a lack of pharmacokinetic (PK) studies. We conducted a retrospective single-center PK and pharmacodynamic (PD) analysis of 34 pediatric intensive care unit patients who received MEM. Individual PK parameters were determined by a two-compartment analysis. The median (range) age and body weight were 1.4 (0.03 to 14.6) years and 8.9 (2.7 to 40.9) kg, respectively, and eight (23.5%) patients received continuous renal replacement therapy (CRRT), three of whom received extracorporeal membrane oxygenation. Renal function, the systemic inflammatory response syndrome (SIRS) score for the clearance (CL), and the use of CRRT for the central volume of distribution (Vc) were identified as significant covariates. The mean CL, Vc, and peripheral volume of distribution (Vp) were 0.45 liters/kg/h, 0.49 liters/kg, and 0.34 liters/kg, respectively. The mean population CL of MEM increased by 35% in patients with SIRS and Vc increased by 66% in patients on CRRT in the final model. Dosing simulations suggested that the standard dosing regimen provided insufficient PD exposures of a 100% free time above the MIC, and higher doses (40 to 80 mg/kg of body weight/dose every 8 h) with a prolonged 3-h infusion were required to ensure the appropriate PD exposures for patients with SIRS. Our PK model indicated that critically ill pediatric patients are at risk of subtherapeutic exposure under the standard dosing regimen of MEM. A larger, prospective investigation confirming the safety and efficacy of higher concentrations and prolonged infusion of MEM is necessary.

Expression and pathophysiological significance of carbohydrate response element binding protein (ChREBP) in the renal tubules of diabetic kidney.

Carbohydrate response element binding protein (ChREBP), a glucose responsive transcription factor, mainly regulates expression of genes involved in glucose metabolism and lipogenesis. Recently, ChREBP is speculated to be involved in the onset and progression of diabetic nephropathy (DN). However, there exists no report regarding the localization and function of ChREBP in the kidney. Therefore, we analyzed the localization of Chrebp mRNA expression in the wild type (WT) mice kidney using laser microdissection method, and observed its dominant expression in the proximal tubules. In diabetic mice, mRNA expression of Chrebp target genes in the proximal tubules, including Chrebpß and thioredoxin-interacting protein (Txnip), significantly increased comparing with that of WT mice. Co-overexpression of ChREBP and its partner Mlx, in the absence of glucose, also increased TXNIP mRNA expression as well as high glucose in human proximal tubular epithelial cell line HK-2. Since TXNIP is well known to be involved in the production of reactive oxygen species (ROS), we next examined the effect of ChREBP/Mlx co-overexpression, in the absence of glucose, on ROS production in HK-2 cells. Interestingly, ChREBP/Mlx co-overexpression also induced ROS production significantly as well as high glucose. Moreover, both high glucose-induced increase of TXNIP mRNA expression and ROS production were abrogated by ChREBP small interfering RNA transfection. Taken together, high glucose-activated ChREBP in the renal proximal tubules induce the expression of TXNIP mRNA, resulting in the production of ROS which may cause renal tubular damage. It is therefore speculated that ChREBP is involved in the onset and progression of DN.

Effect of a Superior Lateral Anterior Pedicle Flap for Draf Procedures.

Several types of flap techniques have been developed to cover exposed bone after Draf procedures to reduce the possibility of re-stenosis. These techniques are relatively new and detailed measurements of the size of neo-Ostia during follow-up have not been reported. The authors aim to assess outcomes precisely by not only using endoscopic evaluation but also by measuring the diameter of the ostium and the thickness of the nasal beaks on pre- and postoperative computed tomography images. The authors reviewed 25 patients with 37 nasal cavities who have undergone a Draf surgery with a previously-reported superior lateral anterior pedicle flap technique. The anteroposterior (AP) distance of the frontal recess and the thickness of the nasal beaks were measured before, immediately after, and more than 6 months after surgery. Measured distances were statistically analyzed. The neo-ostium remained patent in long-term follow-up of all patients. The AP distance of the frontal recess and the thickness of the nasal beak were preserved during follow-up. Neither synechiae nor orbital injuries occurred. In conclusion, Draf type II and III procedures with superior lateral anterior pedicle flaps are safe and effective. Neo-Ostia remained patent throughout the follow-up period.

The reduction of heparan sulphate in the glomerular basement membrane does not augment urinary albumin excretion.

BACKGROUND: Heparan sulphate proteoglycan (HSPG) is present in the glomerular basement membrane (GBM) and is thought to play a major role in the glomerular charge barrier. Reductions and structural alterations of HSPG are observed in different types of kidney diseases accompanied by proteinuria. However, their causal relations remain unknown. METHODS: We generated podocyte-specific exostosin-like 3 gene (Extl3) knockout mice (Extl3KO) using a Cre-loxP recombination approach. A reduction of HSPG was expected in the GBM of these mice, because EXTL3 is involved in its synthesis. Mice were separated into three groups, according to the loads on the glomeruli: a high-protein diet group, a high-protein and high-sodium diet group and a hyperglycaemic group induced by streptozotocin treatment in addition to maintenance on a high-protein and high-sodium diet. The urinary albumin:creatinine ratio was measured at 7, 11, 15 and 19 weeks of age. Renal histology was also investigated. RESULTS: Podocyte-specific expression of Cre recombinase was detected by immunohistochemistry. Moreover, immunofluorescent staining demonstrated a significant reduction of HSPG in the GBM. Electron microscopy showed irregularities in the GBM and effacement of the foot processes in Extl3KO. The values of the urinary albumin:creatinine ratio were within the range of microalbuminuria in all groups and did not significantly differ between the control mice and Extl3KO. CONCLUSIONS: The reduction of HSPG in the GBM did not augment urinary albumin excretion. HSPG's anionic charge appears to contribute little to the glomerular charge barrier.

Manual compression and reflex syncope in native renal biopsy.

BACKGROUND: Complications associated with diagnostic native percutaneous renal biopsy (PRB) must be minimized. While life threatening major complications has been extensively investigated, there is little discussion regarding minor bleeding complications, such as a transient hypotension, which directly affect patients' quality of life. There is also little evidence supporting the need for conventional manual compression following PRB. Therefore, this study evaluated the relationship between minor and major complications incidence in patients following PRB with or without compression. METHODS: This single-center, retrospective study included 456 patients (compression group: n = 71; observation group: n = 385). The compression group completed 15 min of manual compression and 4 h of subsequent strict bed rest with abdominal bandage. The observation group completed 2 h of strict bed rest only. The primary outcome of interest was transient symptomatic hypotension (minor event). RESULTS: Of the 456 patients, 26 patients encountered intraoperative and postoperative transient hypotension, which were considered reflex syncope without tachycardia. Univariate analysis showed that symptomatic transient hypotension was significantly associated with compression. This association remained significant, even after adjustment of covariates using multivariate logistic regression analysis (adjusted odds ratio 3.27; 95% confidential interval 1.36-7.82; P = 0.0078). CONCLUSION: Manual compression and abdominal bandage significantly increased the frequency of reflex syncope during native PRB. It is necessary to consider the potential benefit and risk of compression maneuvers for each patient undergoing this procedure.

The size of the renal artery orifice contributes to laterality of acute renal infarction.

BACKGROUND: Acute renal infarction (ARI) is a rare disease with atrial fibrillation being its main cause. The possible laterality of ARI is controversial. This study aimed to evaluate the association between anatomical features of the renal arteries and ARI. METHODS: This was a single-center cross-sectional study that evaluated the anatomical and clinical features of renal arteries. The anatomical features of the renal arteries were assessed using computed tomography. RESULTS: A total of 46 patients (mean age 71.3 ± 14.0 years; men, 59%) were enrolled. ARI involved the left kidney in 63%, right kidney in 28%, and both kidneys in 9% of patients. The right renal artery orifice was often higher than that of the left renal artery (71%). The angle of divergence from the abdominal aorta was similar on both sides. The left renal artery orifice was larger than that of the right (83 ± 24, 72 ± 24 mm2; p = 0.03, respectively). A larger left orifice was present in 72% of all cases. ARI involved the side with the larger orifice in 64% of patients. CONCLUSION: The size of the renal artery orifice may be a factor that contributes to the laterality of ARI. Assessment of anatomical features is important when considering the laterality of the disease.

Rapidly progressive renal failure due to tubulointerstitial infiltration of peripheral T-cell lymphoma, not otherwise specified accompanied by uveitis: a case report.

BACKGROUND: Rapid decline in renal dysfunction due to primary renal lymphoma, or secondary renal lymphoma by infiltration from a primary origin, is extremely rare. There are notably few reports indicating infiltration of T-cell lymphoma into the kidney. CASE PRESENTATION: A 61-year-old woman with a sudden body rash and liver dysfunction was brought to our hospital presenting with a dull headache and blurred vision. Laboratory tests revealed rapidly progressive renal failure. Histological examination of the kidney and skin indicated infiltration of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). Infiltration of PTCL-NOS to the liver and spleen, and presence of Uveitis masquerade syndrome were suspected. Imaging showed that the lesion was limited to extralymphatic organs. Renal function was improved with administration of steroids, including pulse steroid therapy, before administering cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) therapy. CONCLUSIONS: This is the first reported case of rapidly progressive renal failure caused by perivascular tubulointerstitial nephritis with the direct invasion of PTCL-NOS. In our case, a single steroid dose showed dramatic results with respect to renal symptoms.

Leptospirosis in the Tohoku region: re-emerging infectious disease.

Leptospirosis is a zoonotic and disaster-related infectious disease. It is mainly endemic in subtropical or tropical countries and has not been reported since 2009 in the Tohoku region (northern Japan), including the Yamagata and Miyagi Prefectures. However, we experienced four patients with leptospirosis in the Tohoku region from 2012 to 2014; three patients (#1-3) live in the agricultural areas of the Yamagata Prefecture and one patient (#4) was a visitor to the Miyagi Prefecture. Patient 1 (81-year-old female) is a villager, with a rat bite, while Patient 2 (77-year-old male) and Patient 3 (84-year-old female) are farmers and were infected probably during agriculture work. Patient 4 (40-year-old male US citizen) was infected while traveling in Thailand. They had chief complaint of fever, headache, and myalgia and showed manifestations of hyperbilirubinemia (mean, 4.35 mg/dL), thrombocytopenia and acute kidney injury (AKI). All patients were diagnosed by polymerase chain reaction using blood and/or urine samples and a microscopic agglutination test for the anti-Leptospira antibody. All the patients were treated with infused antibiotics, including minocycline. The patients underwent hemodialysis due to severe AKI (mean serum creatinine, 4.44 mg/dL), except for Patient 2 with the normal serum creatinine level (1.12 mg/dL). All the patients recovered and were discharged. The presence of the three patients in the Yamagata Prefecture implies that leptospirosis does re-emerge in the Tohoku region. Therefore, careful survey of the pathogen is necessary for febrile patients with AKI who engage in agriculture or have a recent history of travelling in subtropical or tropical countries.

Estimation of the success rate of anesthetic management for thymectomy in patients with myasthenia gravis treated without muscle relaxants: a retrospective observational cohort study.

Although maintaining anesthesia for myasthenia gravis (MG) with minimal muscle relaxants (MR) is common, the success rate of anesthetic management for MG without MR is not clear. We therefore retrospectively examined the success rate of anesthetic management for MG without MR among 66 consecutive cases of thymectomy for MG performed at our hospital between January 2004 and April 2010, before approval of using sugammadex. A total of 60 patients (90.9 %) were treated without MR (N group). Among the 60 cases, 17 (28.3 %) patients were not extubated in the operating room due to postoperative respiratory depression or other reasons. Therefore, the success rate of anesthetic management for thymectomy in patients with MG without treating MR was 71.7 % (43/60) [95 % confident interval (CI): 65.9-77.5 %]. The reasons for using MR included coughing at intubation in one case, bucking during surgery in two cases, and MR was considered to be safer by the attending anesthesiologist in three cases. The number of cases of impossible extubation requiring ventilation on that day was three in the N group and none in the R group. Finally, the success rate of anesthetic management for MG without MR was estimated to be 71.1 % (95 % CI: 65.9-77.5 %).

Kernel density estimation of allele frequency including undetected alleles.

Whereas undetected species contribute to estimation of species diversity, undetected alleles have not been used to estimated genetic diversity. Although random sampling guarantees unbiased estimation of allele frequency and genetic diversity measures, using undetected alleles may provide biased but more precise estimators useful for conservation. We newly devised kernel density estimation (KDE) for allele frequency including undetected alleles and tested it in estimation of allele frequency and nucleotide diversity using population generated by coalescent simulation as well as well as real population data. Contrary to expectations, nucleotide diversity estimated by KDE had worse bias and accuracy. Allele frequency estimated by KDE was also worse except when the sample size was small. These might be due to finity of population and/or the curse of dimensionality. In conclusion, KDE of allele frequency does not contribute to genetic diversity estimation.

Nasal Packing Materials and Placement Duration on Wound Healing in Nasal Mucosa: An Animal Study.

OBJECTIVE: The histological findings of wound healing depending on different nasal packing materials and replacement periods were lacking. METHODS: Mucosal defects were created in the nasal septum of rabbits and covered with Spongel®, Algoderm®, or Nasopore®, which were cleaned on Day 14. To investigate the effect of replacement durations, Spongel® was removed on Days 3 and 7. All nasal septal specimens were collected on Day 28. Samples without packing material were prepared as controls. Depending on residual packing materials in the regenerated tissue, specimens were classified into the remnant and non-remnant groups, and morphology was compared using epithelium grade score and subepithelial thickness. RESULTS: The epithelium grade score in the Spongel-14d group was lower than that in the other groups (p < 0.05). Subepithelial thickness was higher in the Algoderm-14d and Spongel-14d groups (p < 0.05). Epithelium grade scores were higher and subepithelial thicknesses were lower in the Spongel-3d and -7d groups than in the Spongel-14d group. Epithelium grade score was lower and subepithelial thickness was higher in the remnant group (n = 10) than in the non-remnant group (n = 15; p < 0.05). CONCLUSIONS: Differences in packing materials and placement durations affected wound healing of nasal mucosa. The selection of appropriate packing materials and replacement duration was considered essential for ideal wound healing. LEVEL OF EVIDENCE: NA Laryngoscope, 134:562-568, 2024.

Simple and safe resection of the crista galli.

A critical procedure in the transcribriform approach is the resection of the crista galli. However, the standard technique for crista galli resection has several disadvantages. We reviewed the cases of patients with olfactory neuroblastomas who underwent an endoscopic endonasal transcribriform approach using a newly developed technique for crista galli resection. We performed a cadaveric study to measure the superior accessibility limits using the proposed method. We included 38 patients with olfactory neuroblastomas in this study. The tumor invaded the posterior crista galli in four patients. The anterior end of the crista galli was not invaded by the tumor. Our cadaveric study showed that the dura was approachable to the point that was 7.4 ± 1.3 mm superior and 23.2 ± 7.2 mm lateral to the foramen cecum following crista galli removal. By resecting the crista galli in advance, manipulation of the superior dura became feasible.