Deep learning-based detection of lumbar spinal canal stenosis using convolutional neural networks.

BACKGROUND CONTEXT: Lumbar spinal canal stenosis (LSCS) is the most common spinal degenerative disorder in elderly people and usually first seen by primary care physicians or orthopedic surgeons who are not spine surgery specialists. Magnetic resonance imaging (MRI) is useful in the diagnosis of LSCS, but the equipment is often not available or difficult to read. LSCS patients with progressive neurologic deficits have difficulty with recovery if surgical treatment is delayed. So, early diagnosis and determination of appropriate surgical indications are crucial in the treatment of LSCS. Convolutional neural networks (CNNs), a type of deep learning, offers significant advantages for image recognition and classification, and work well with radiographs, which can be easily taken at any facility. PURPOSE: Our purpose was to develop an algorithm to diagnose the presence or absence of LSCS requiring surgery from plain radiographs using CNNs. STUDY DESIGN: Retrospective analysis of consecutive, nonrandomized series of patients at a single institution. PATIENT SAMPLE: Data of 150 patients who underwent surgery for LSCS, including degenerative spondylolisthesis, at a single institution from January 2022 to August 2022, were collected. Additionally, 25 patients who underwent surgery at two other hospitals were included for extra external validation. OUTCOME MEASURES: In annotation 1, the area under the curve (AUC) computed from the receiver operating characteristic (ROC) curve, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated. In annotation 2, correlation coefficients were used. METHODS: Four intervertebral levels from L1/2 to L4/5 were extracted as region of interest from lateral plain lumbar spine radiographs totaling 600 images were obtained. Based on the date of surgery, 500 images derived from the first 125 cases were used for internal validation, and 100 images from the subsequent 25 cases used for external validation. Additionally, 100 images from other hospitals were used for extra external validation. In annotation 1, binary classification of operative and nonoperative levels was used, and in annotation 2, the spinal canal area measured on axial MRI was labeled as the output layer. For internal validation, the 500 images were divided into each 5 dataset on per-patient basis and five-fold cross-validation was performed. Five trained models were registered in the external validation prediction performance. Grad-CAM was used to visualize area with the high features extracted by CNNs. RESULTS: In internal validation, the AUC and accuracy for annotation 1 ranged between 0.85-0.89 and 79-83%, respectively, and the correlation coefficients for annotation 2 ranged between 0.53-0.64 (all P < 0.01). In external validation, the AUC and accuracy for annotation 1 were 0.90 and 82%, respectively, and the correlation coefficient for annotation 2 was 0.69, using five trained CNN models. In the extra external validation, the AUC and accuracy for annotation 1 were 0.89 and 84%, respectively, and the correlation coefficient for annotation 2 was 0.56. Grad-CAM showed high feature density in the intervertebral joints and posterior intervertebral discs. CONCLUSIONS: This technology automatically detects LSCS from plain lumbar spine radiographs, making it possible for medical facilities without MRI or non-specialists to diagnose LSCS, suggesting the possibility of eliminating delays in the diagnosis and treatment of LSCS that require early treatment.

Bone Marrow Aspirate Concentrate Combined with Ultra-Purified Alginate Bioresorbable Gel Enhances Intervertebral Disc Repair in a Canine Model: A Preclinical Proof-of-Concept Study.

Although discectomy is commonly performed for lumbar intervertebral disc (IVD) herniation, the capacity for tissue repair after surgery is limited, resulting in residual lower back pain, recurrence of IVD herniation, and progression of IVD degeneration. Cell-based therapies, as one-step procedures, are desirable for enhancing IVD repair. This study aimed to investigate the therapeutic efficacy of a combination of newly developed ultra-purified alginate (UPAL) gel and bone marrow aspirate concentrate (BMAC) implantation for IVD repair after discectomy. Prior to an in vivo study, the cell concentration abilities of three commercially available preparation kits for creating the BMAC were compared by measuring the number of bone marrow mesenchymal stem cells harvested from the bone marrow of rabbits. Subsequently, canine-derived BMAC was tested in a canine model using a kit which had the highest concentration rate. At 24 weeks after implantation, we evaluated the changes in the magnetic resonance imaging (MRI) signals as well as histological degeneration grade and immunohistochemical analysis results for type II and type I collagen-positive cells in the treated IVDs. In all quantitative evaluations, such as MRI and histological and immunohistochemical analyses of IVD degeneration, BMAC-UPAL implantation significantly suppressed the progression of IVD degeneration compared to discectomy and UPAL alone. This preclinical proof-of-concept study demonstrated the potential efficacy of BMAC-UPAL gel as a therapeutic strategy for implementation after discectomy, which was superior to UPAL and discectomy alone in terms of tissue repair and regenerative potential.

The Efficacy of Systemic Transdermal Diclofenac Patch for Postoperative Pain after Lumbar Spinal Surgery.

STUDY DESIGN: A single-center, prospective, comparative study. OBJECTIVE: This study aimed to investigate the efficacy and safety of the systemic transdermal diclofenac patch (DP) for immediate postoperative analgesia after lumbar spinal surgery. SUMMARY OF BACKGROUND DATA: Effective wound pain control after spinal surgery has been shown to lead to favorable outcomes. Using multimodal analgesia may decrease opioid use for postoperative pain. MATERIALS AND METHODS: Patients who underwent posterior lumbar spinal surgery between August 2022 and January 2023 were divided into two groups: patients who underwent surgery on even months and were treated with DP (DP [+] group) and those who underwent surgery on odd months and were not treated with DP (DP [-] group). The demographic data, morphine milligram equivalent (MMEs) within 24 hours, duration of hospitalization, number of rescue analgesics used, visual analog scale (VAS) scores of wound pain, deterioration in renal function, and other complications were compared. Subgroup analysis consisted of subgroups categorized based on surgical procedure (non-fusion or fusion surgery). RESULTS: In total, 111 and 113 patients were enrolled in the DP (+) and DP (-) groups, respectively. There was no significant difference in the deterioration of renal function in the DP (+) group. Overall comparisons demonstrated a significant difference between the DP (+) and DP (-) groups in the number of rescue analgesics used within 1 hour (P=0.046). In the non-fusion surgery subgroups, the MMEs within 24 hours, the number of rescue analgesics used within 1 and 3 hours, as well as the wound pain VAS at 1 and 3 hours postoperatively were significantly lower in the DP (+) group than in the DP (-) group (P=0.010, 0.015, 0.029, 0.005, and 0.048 respectively). CONCLUSION: Systemic transdermal DP may potentially offer safe and effective postoperative analgesia, especially in less invasive procedures such as non-fusion lumbar spinal surgery. LEVEL OF EVIDENCE: Level III.

Development of Notch-Free, Pre-Bent Rod Applicable for Posterior Corrective Surgery of Thoracolumbar/Lumbar Adolescent Idiopathic Scoliosis.

Adolescent idiopathic scoliosis (AIS), the most common pediatric musculoskeletal disorder, causes a three-dimensional spine deformity. Lenke type 5 AIS is defined as a structural thoracolumbar/lumbar curve with nonstructural thoracic curves. Although a rod curvature will affect clinical outcomes, intraoperative contouring of the straight rod depends on the surgeon's knowledge and experience. This study aimed to determine the optimum rod geometries to provide a pre-bent rod system for posterior spinal surgery in patients with Lenke type 5 AIS. These pre-bent rods will be beneficial for achieving proper postoperative outcomes without rod contouring based on surgeon experience. We investigated 20 rod geometries traced in posterior spinal reconstruction in patients with Lenke type 5 AIS. The differences between the center point clouds in each cluster were evaluated using the iterative closest point (ICP) method with modification. Before the evaluation using the ICP method, the point clouds were divided into four clusters based on the rod length using a hierarchical cluster analysis. Because the differences in the values derived from the ICP method were <5 mm for each length-based cluster, four representative rod shapes were generated from the length-based clusters. We identified four optimized rod shapes that will reduce operation time, leading to a decreased patient and surgeon burden.

Prediction of Cobb Angle Using Deep Learning Algorithm with Three-Dimensional Depth Sensor Considering the Influence of Garment in Idiopathic Scoliosis.

Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal deformity. Early detection of deformity and timely intervention, such as brace treatment, can help inhibit progressive changes. A three-dimensional (3D) depth-sensor imaging system with a convolutional neural network was previously developed to predict the Cobb angle. The purpose of the present study was to (1) evaluate the performance of the deep learning algorithm (DLA) in predicting the Cobb angle and (2) assess the predictive ability depending on the presence or absence of clothing in a prospective analysis. We included 100 subjects with suspected AIS. The correlation coefficient between the actual and predicted Cobb angles was 0.87, and the mean absolute error and root mean square error were 4.7° and 6.0°, respectively, for Adam's forward bending without underwear. There were no significant differences in the correlation coefficients between the groups with and without underwear in the forward-bending posture. The performance of the DLA with a 3D depth sensor was validated using an independent external validation dataset. Because the psychological burden of children and adolescents on naked body imaging is an unignorable problem, scoliosis examination with underwear is a valuable alternative in clinics or schools.

The Influence of Aryl Substituents on the Supramolecular Structures and Photoluminescence of Cyclic Trinuclear Pyrazolato Copper(I) Complexes.

Cyclic trinuclear complexes with group 11 metal(I) ions are fascinating and important to coordination chemistry. One of the ligands known to form these cyclic trinuclear complexes is pyrazolate, which is a bridging ligand that coordinates many transition metal ions in a Npz-M-Npz linear mode (Npz = pyrazolyl nitrogen atom). In these group 11 metal(I) ions, copper is the most abundant metal. Therefore, polynuclear copper(I) complexes are very important in this field. The cyclic trinuclear copper(I) complex [Cu(3,5-Ph2pz)]3 (3,5-Ph2pz- = 3,5-diphenyl-1-pyrazolate anion) was reported in 1988 as a landmark complex, but its photoluminescence properties have hitherto not been described. In this study, we report the photoluminescence and two different polymorphs of [Cu(3,5-Ph2pz)]3 and its derivative [Cu(3-Me-5-Phpz)]3 (3-Me-5-Phpz- = 3-metyl-5-phenyl-1-pyrazale anion). The substituents in [Cu(3-Me-5-Phpz)]3 cause smaller distortions in the solid-state structure and a red-shift in photoluminescence due to the presence of intermolecular cuprophilic interactions.

The U-shaped association of serum iron level with disease severity in adult hospitalized patients with COVID-19.

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that leads to severe respiratory failure (RF). It is known that host exposure to viral infection triggers an iron-lowering response to mitigate pathogenic load and tissue damage. However, the association between host iron-lowering response and COVID-19 severity is not clear. This two-center observational study of 136 adult hospitalized COVID-19 patients analyzed the association between disease severity and initial serum iron, total iron-binding capacity (TIBC), and transferrin saturation (TSAT) levels. Serum iron levels were significantly lower in patients with mild RF than in the non-RF group; however, there were no significant differences in iron levels between the non-RF and severe RF groups, depicting a U-shaped association between serum iron levels and disease severity. TIBC levels decreased significantly with increasing severity; consequently, TSAT was significantly higher in patients with severe RF than in other patients. Multivariate analysis including only patients with RF adjusted for age and sex demonstrated that higher serum iron and TSAT levels were independently associated with the development of severe RF, indicating that inadequate response to lower serum iron might be an exacerbating factor for COVID-19.

Diacylglycerol kinase δ functions as a proliferation suppressor in pancreatic ß-cells.

Although an aberrant reduction in pancreatic ß-cell mass contributes to the pathogenesis of diabetes, the mechanism underlying the regulation of ß-cell mass is poorly understood. Here, we show that diacylglycerol kinase δ (DGKδ) is a key enzyme in the regulation of ß-cell mass. DGKδ expression was detected in the nucleus of ß-cells. We developed ß-cell-specific DGKδ knockout (ßDGKδ KO) mice, which showed lower blood glucose, higher plasma insulin levels, and better glucose tolerance compared to control mice. Moreover, an increased number of small islets and Ki-67-positive islet cells, as well as elevated cyclin B1 expression in the islets, were detected in the pancreas of ßDGKδ KO mice. DGKδ knockdown in the ß-cell line MIN6 induced significant increases in bromodeoxyuridine (BrdU) incorporation and cyclin B1 expression. Finally, we confirmed that streptozotocin-induced hyperglycemia and ß-cell loss were alleviated in ßDGKδ KO mice. Thus, suppressing the expression or enzymatic activity of DGKδ that functions as a suppressor of ß-cell proliferation could be a novel therapeutic approach to increase ß-cell mass for the treatment of diabetes.

Incidental induction of secondary bowel disorders in guinea pigs during a batch safety test of veterinary vaccines.

Veterinary vaccines are subjected to a safety testing using laboratory animals via intraperitoneal injection per batch. From April 2010 to March 2011, 7 guinea pigs in 4 batch tests exhibited unrecoverable weight loss and/or were found dead. Six guinea pigs had developed intussusception, whereas another one had developed an intestinal obstruction consequent to adhesion. A histopathology revealed that these lesions were associated with inflammatory foci. Other animals than the 7 guinea pig also developed similar inflammatory foci but did not develop bowel disorders. In the retesting of these batches, animals did not exhibited clinical signs, though inflammatory foci were detected. The clinical signs, detected in the primary test, might be due to bowel disorders secondary to an inflammatory response, rather than toxicity.

Activation of Ralfuranone/Ralstonin Production by Plant Sugars Functions in the Virulence of Ralstonia solanacearum.

Plant pathogenic bacteria possess sophisticated mechanisms to detect the presence of host plants by sensing host-derived compounds. Ralstonia solanacearum, the causative agent of bacterial wilt on solanaceous plants, employs quorum sensing to control the production of the secondary metabolite ralfuranones/ralstonins, which have been suggested to be involved in virulence. Here, we report that d-galactose and d-glucose, plant sugars, activate the production of ralfuranones/ralstonins in R. solanacearum. As a result, two new derivatives, ralfuranone M (1) and ralstonin C (2), were found in the culture extracts, and their structures were elucidated by spectroscopic and chemical methods. Ralstonin C (2) is a cyclic lipopeptide containing a unique fatty acid, (2S,3S,Z)-3-amino-2-hydroxyicos-13-enoic acid, whereas ralfuranone M (1) has a common aryl-furanone structure with other ralfuranones. d-Galactose and d-glucose activated the expression of the biosynthetic ralfuranone/ralstonin genes and in part became the biosynthetic source of ralfuranones/ralstonins. Ralfuranones and ralstonins were detected from the xylem fluid of the infected tomato plants, and their production-deficient mutants exhibited reduced virulence on tomato and tobacco plants. Taken together, these results suggest that activation of ralfuranone/ralstonin production by host sugars functions in R. solanacearum virulence.

Female paraurethral leiomyoma successfully excised through a vaginal approach: A case report.

Paraurethral leiomyomas are extremely rare, and few cases have been reported in the literature. Because of the rarity of the disease and its anatomical complexity, diagnosis and management is challenging for clinicians. Here, we herein report the case of a 50-year-old woman who complained of a protruding mass at the urethral opening. Magnetic resonance imaging revealed a sharply defined tumor measuring 43 × 36 × 26 mm in diameter, located in the anterior vaginal wall, compressing the urethra. Based on the perioperative diagnosis of leiomyoma, the paraurethral tumor was excised via the vaginal approach. The patient was discharged 4 days postoperatively without any complications. Pathological features confirmed the diagnosis of leiomyoma. This case implies that, although there is the possibility of complications due to the surgical procedure, tumor removal is a reasonable choice for management to exclude malignancy and relieve symptoms.

The effects of post and core material combination on the surface strain of the 4-unit zirconia fixed partial denture margins.

The suitability of various post and core materials for the 4-unit zirconia fixed partial denture abutment teeth was investigated to lower stress concentration. Artificial mandibular teeth (44 and 47) were used as the abutment teeth. There were two types of posts and cores: resin composite with glass fiber posts (RC), and cast platinum gold alloy (MC). Two experimental groups were analyzed. For Group RM, the premolars were restored with RC and the molars were restored with MC. For Group MR, the premolars were restored with MC and the molars were restored with RC. Static loading was applied to the occlusal surfaces, and the surface strain of the frameworks and roots was measured with a strain gauge. Group RM had a greater number of statistical differences between premolars and molars compared to Group MR. This result suggests that the Group MR post and core material combination reduces stress concentration.

Immunoreactivity and morphological changes of bursal follicles in chickens infected with vaccine or wild-type strains of the infectious bursal disease virus.

Infectious bursal disease (IBD) is characterized by immunosuppression due to the depletion of lymphocytes in the atrophied bursa of Fabricius (BF). We have sometimes encountered contradictory findings: chickens infected with the vaccine IBD virus (IBDV) strain have sometimes exhibited a highly atrophied BF, but not immunosuppression. In this study, chickens administered vaccine or wild-type strains of IBDV were later vaccinated with the B1 strain of the Newcastle disease virus (NDV). Bursal changes were examined histologically with a focus on the bursal follicle. The immunoreactivity to NDV was also evaluated with the hemagglutination inhibition test. In gross examination, we observed a few chickens with a severely atrophied BF in vaccine strain-administered groups (vaccine groups), and the level of severity was the same as that in the wild-type strain-administered group (wild-type group). However, these chickens retained humoral antibody responses to NDV and were revealed to possess a higher number of bursal follicles than those of the wild-type group. These results indicated that macroscopic evaluation dose not accurately reflect the immunoreactivity and degree of bursal damage in IBDV-administered chickens. We also found non-immunosuppressed chickens in the wild-type group. These non-immunosuppressed chickens retained a significantly higher number of normal follicles and total follicles according to our statistical analysis. Furthermore, a high correlation coefficient between the NDV-HI titer and the number of normal follicles was found in the wild-type group. These results implied that the retained number of normal follicles is important for the immunoreactivity of chickens infected with IBDV.

Olanzapine induces glucose intolerance through the activation of AMPK in the mouse hypothalamus.

Treatment with atypical antipsychotic drugs is known to increase the risk of glucose intolerance and diabetes. However, the mechanism of this effect is unclear. Since central adenosine 5'-monophosphate-activated protein kinase (AMPK) plays an important role in regulating nutrient homeostasis, the present study was performed to examine the involvement of central AMPK in the glucose intolerance induced by olanzapine, an atypical antipsychotic drug, in mice. Acute intraperitoneal treatment with olanzapine dose-dependently increased blood glucose levels in the glucose tolerance test. Intracerebroventricular administration of olanzapine also increased blood glucose levels in the glucose tolerance test. The glucose intolerance induced by both intraperitoneal and intracerebroventricular treatment with olanzapine was significantly attenuated by intracerebroventricular pretreatment with the AMPK inhibitor compound C. Intracerebroventricular treatment with the AMPK activator AICAR increased blood glucose levels in the glucose tolerance test, and this increase was inhibited by compound C. Moreover, the hypothalamic level of phosphorylated AMPK after glucose injection was significantly increased by intracerebroventricular pretreatment with olanzapine. Olanzapine did not affect plasma glucagon and insulin levels. Our results indicate that acute treatment with olanzapine causes glucose intolerance through the activation of hypothalamic AMPK. The present study suggests that the inhibition of central AMPK activity may have a therapeutic effect on the metabolic disturbance induced by atypical antipsychotic drugs.

Total anomalous pulmonary venous connection in a chicken.

This report describes a case of total anomalous pulmonary venous connection (TAPVC) in a 5-wk-old male white leghorn chicken that presented with growth retardation. This chicken was a specific-pathogen-free chicken bred in an isolator. At 5 wk of age, the chicken was euthanatized and autopsied. Macroscopically, the right ventricle and right atrium were significantly enlarged whereas the left atrium was small and blind-ending with no connection to the pulmonary veins. The pulmonary veins were connected directly to the right atrium. The above abnormality was accompanied by an ostium secundum-type atrial septal defect. No other malformations were observed. TAPVC is a very rare congenital cardiac abnormality that has not been reported in avian species to date.

Small heat shock protein AgsA: an effective stabilizer of enzyme activities.

A small heat shock protein, AgsA, possesses chaperone activity that can reduce the amount of heat-aggregated protein in vivo, and suppress the aggregation of chemical- and heat-denatured proteins in vitro. Therefore, we examined the ability of AgsA to stabilize the activity of several enzymes by using this chaperone activity. We observed that AgsA can stabilize the enzymatic activities of Renilla (Renilla reniformis) luciferase, firefly (Photinus pyralis) luciferase, and ß-galactosidase, and showed comparable or greater stabilization of these enzymes than bovine serum albumin (BSA), a well-known stabilizer of enzyme activities. In particular, AgsA revealed better stabilization of Renilla luciferase and ß-galactosidase than BSA under disulfide bond-reducing conditions with dithiothreitol. In addition, AgsA also increased the enzymatic performance of ß-galactosidase and various restriction enzymes to a comparable or greater extent than BSA. These data indicate that AgsA may be useful as a general stabilizer of enzyme activities.

Possible involvement of tetrodotoxin-resistant sodium channels in cough reflex.

We examined the involvement of tetrodotoxin (TTX)-resistant sodium channels in the peripheral mechanisms of the cough reflex in mice. We also examined the possibility of using ambroxol as an effective antitussive agent, and found that it produced antitussive effects through the inhibition of TTX-resistant sodium channels. The inhalation of fenvalerate, at concentrations of 0.3, 1 and 3µg/ml, for 5min produced coughs in a concentration-dependent manner. Pretreatment with tetrodotoxin, at a dose of 1µg/kg, s.c., slightly but significantly reduced the number of fenvalerate (3µg/ml)-induced coughs. However, the number of fenvalerate-induced coughs in tetorodotoxin-treated mice was still significantly greater than those in vehicle (0.4% DMSO) alone inhaled mice. On the other hand, pretreatment with tetrodotoxin, at a dose of 1µg/kg, s.c., almost completely reduced the number of citric acid (0.25M)-induced coughs to the level in vehicle (saline) alone inhaled mice. Pretreatment with ambroxol, at doses of 10, 30, 100 and 300mg/kg, p.o., dose-dependently and significantly reduced the number of fenvalerate (3µg/ml)-induced coughs. The present findings indicate that TTX-resistant sodium channels may play an important role in the enhancement of C-fiber-mediated cough pathways. Furthermore, ambroxol may prove to be a useful cough suppressant.

[Influence on the physical characteristics of medical color liquid crystal displays with increase in aperture ratio].

We measured the physical characteristics of 2-million(2M)and 3-million(3M)color liquid crystal displays(LCD)whose aperture ratio was increased and compared them with conventional models. The results showed the influence of the increased aperture ratio on the physical characteristics of the LCDs. We evaluated resolution by means of modulation transfer function(MTF)and evaluated granularity by means of noise power spectrum(NPS). Each of the measurements was done with a high-resolution single-lens reflex-type digital camera. A decrease of MTF depending on sub-pixel structures was recognized. A decrease in the cross sub-pixel direction was recognized in the 2M model, and a decrease in the sub-pixel direction was recognized in the 3M model. As for NPS, a reduction was recognized in the sub-pixel and the cross sub-pixel direction in both models. As a result, an improvement in granularity was recognized. The improvement in granularity was large with the color LCDs whose aperture ratio was increased. The increase of an aperture ratio influenced both MTF and NPS, and the results depended on the shape and size of the sub-pixel cells.