Current status of artificial intelligence technologies in pituitary adenoma surgery: a scoping review.

PURPOSE: Pituitary adenoma surgery is a complex procedure due to critical adjacent neurovascular structures, variations in size and extensions of the lesions, and potential hormonal imbalances. The integration of artificial intelligence (AI) and machine learning (ML) has demonstrated considerable potential in assisting neurosurgeons in decision-making, optimizing surgical outcomes, and providing real-time feedback. This scoping review comprehensively summarizes the current status of AI/ML technologies in pituitary adenoma surgery, highlighting their strengths and limitations. METHODS: PubMed, Embase, Web of Science, and Scopus were searched following the PRISMA-ScR guidelines. Studies discussing the use of AI/ML in pituitary adenoma surgery were included. Eligible studies were grouped to analyze the different outcomes of interest of current AI/ML technologies. RESULTS: Among the 2438 identified articles, 44 studies met the inclusion criteria, with a total of seventeen different algorithms utilized across all studies. Studies were divided into two groups based on their input type: clinicopathological and imaging input. The four main outcome variables evaluated in the studies included: outcome (remission, recurrence or progression, gross-total resection, vision improvement, and hormonal recovery), complications (CSF leak, readmission, hyponatremia, and hypopituitarism), cost, and adenoma-related factors (aggressiveness, consistency, and Ki-67 labeling) prediction. Three studies focusing on workflow analysis and real-time navigation were discussed separately. CONCLUSION: AI/ML modeling holds promise for improving pituitary adenoma surgery by enhancing preoperative planning and optimizing surgical strategies. However, addressing challenges such as algorithm selection, performance evaluation, data heterogeneity, and ethics is essential to establish robust and reliable ML models that can revolutionize neurosurgical practice and benefit patients.

Development of Catalytic Site-Selective C-H Oxidation.

Direct C-H bond oxygenation is a strong and useful tool for the construction of oxygen functional groups. After Chen and White's pioneering works, various non-heme-type iron and manganese complexes were introduced, leading to strong development in this area. However, for this method to become a truly useful tool for synthetic organic chemistry, it is necessary to make further efforts to improve site-selectivity, and catalyst durability. Recently, we found that non-heme-type ruthenium complex cis-1 presents efficient catalysis in C(sp3 )-H oxygenation under acidic conditions. cis-1-catalysed C-H oxygenation can oxidize various substrates including highly complex natural compounds using hypervalent iodine reagents as a terminal oxidant. Moreover, the catalyst system can use almost stoichiometric water molecules as the oxygen source through reversible hydrolysis of PhI(OCOR)2 . It is a strong tool for producing isotopic-oxygen-labelled compounds. Moreover, the environmentally friendly hydrogen peroxide can be used as a terminal oxidant under acidic conditions.

Iridium(III)-Catalyzed Asymmetric Site-Selective Carbene C-H Insertion during Late-Stage Transformation.

C-H functionalization has recently received considerable attention because C-H functionalization during the late-stage transformation is a strong and useful tool for the modification of the bioactive compounds and the creation of new active molecules. Although a carbene transfer reaction can directly convert a C-H bond to the desired C-C bond in a stereoselective manner, its application in late-stage material transformation is limited. Here, we observed that the iridium-salen complex 6 exhibited efficient catalysis in asymmetric carbene C-H insertion reactions. Under optimized conditions, benzylic, allylic, and propargylic C-H bonds were converted to desired C-C bonds in an excellent stereoselective manner. Excellent regioselectivity was demonstrated in the reaction using not only simple substrate but also natural products, bearing multiple reaction sites. Moreover, based on the mechanistic studies, the iridium-catalyzed unique C-H insertion reaction involved rate-determining asynchronous concerted processes.

Infrafloccular approach effectively prevents hearing complication in microvascular decompression surgery for hemifacial spasm.

OBJECTIVE: The infrafloccular approach in microvascular decompression (MVD) surgery for hemifacial spasm (HFS) was investigated for the prevention of hearing complications. METHODS: Retrospective analysis of 136 patients who underwent MVD for HFS in 2019. The infrafloccular approach for MVD was adopted to resolve the symptom and protect hearing function. Postoperative hearing function was evaluated subjectively and objectively within 30 postoperative days, and later mainly subjectively. Postoperative condition of mastoid air cells based on the CT scan of the following day was also recorded. RESULTS: No final postoperative subjective hearing impairment was found in all patients. Mastoid air cells were opened in 105 patients, and subjective hearing impairment was recorded in 57 patients within 30 postoperative days, but all improved later. Increases in thresholds of greater than 10 dB in air conduction were observed in 28 patients, including 26 of transient conductive hearing loss (increases in the threshold of less than or equal to 10 dB). The other 2 patients with increases in the threshold of greater than 10 dB in both air and bone conduction had improvement confirmed by later audiometry. CONCLUSIONS: Infrafloccular approach in MVD for HFS provides a good hearing outcome. Inclusion of postoperative hearing conditions in the later period is ideal for a precise hearing evaluation.

Preparation of Oxysterols by C-H Oxidation of Dibromocholestane with Ru(Bpga) Catalyst.

Seven mono- and dihydroxycholesterols were prepared by direct C-H oxidation of the cholestane skeleton with a recently developed Ru(Bpga) catalyst (Ru(Bpga) = [RuCl (bpga) (PPh3)] Cl; bpga = 2-(bis(pyridin-2-ylmethyl)amino)-N-(2,6-dimethylphenyl)acetamide)). Due to the high selectivity of the Ru(Bpga) complex for tertiary C-H, the reaction afforded a mixture of 25-, 20-, 17-, and 14-oxygenated cholesterols that could be easily separated by high-performance liquid chromatography. These results suggest that late-stage C-H oxidation could be a viable strategy for preparing candidate metabolites of biologically important molecules.

Ruthenium-Catalyzed Chemo- and Enantioselective Hydrogenation of Isoquinoline Carbocycles.

A chemoselective hydrogenation of isoquinoline carbocycles was achieved by using the catalyst prepared from Ru(methallyl)2(cod) and trans-chelate chiral ligand PhTRAP. The unique chemoselectivity achieved in this hydrogenation could be ascribed to the trans-chelation of the chiral ligand. The procedure for preparing the catalyst strongly affects the reproducibility of the carbocycle hydrogenation. Various 5-, 6-, 7-, and 8-substituted isoquinolines were selectively hydrogenated at their carbocycles to afford 5,6,7,8-tetrahydroisoquinolines as major products in high yields with moderate or good enantioselectivities. Some mechanistic studies suggested that the stereogenic center was created during the initial addition of H2 to the aromatic ring in the hydrogenation of 5-substituted isoquinolines. In other words, the stereochemical control was accompanied by the dearomatization.

De novo design of protein-protein interactions through modification of inter-molecular helix-helix interface residues.

For de novo design of protein-protein interactions (PPIs), information on the shape and chemical complementarity of their interfaces is generally required. Recent advances in computational PPI design have allowed for de novo design of protein complexes, and several successful examples have been reported. In addition, a simple and easy-to-use approach has also been reported that arranges leucines on a solvent-accessible region of an α-helix and places charged residues around the leucine patch to induce interactions between the two helical peptides. For this study, we adopted this approach to de novo design a new PPI between the helical bundle proteins sulerythrin and LARFH. A non-polar patch was created on an α-helix of LARFH around which arginine residues were introduced to retain its solubility. The strongest interaction found was for the LARFH variant cysLARFH-IV-3L3R and the sulerythrin mutant 6L6D (KD=0.16 µM). This artificial protein complex is maintained by hydrophobic and ionic interactions formed by the inter-molecular helical bundle structure. Therefore, by the simple and easy-to-use approach to create de novo interfaces on the α-helices, we successfully generated an artificial PPI. We also created a second LARFH variant with the non-polar patch surrounded by positively charged residues at each end. Upon mixing this LARFH variant with 6L6D, mesh-like fibrous nanostructures were observed by atomic force microscopy. Our method may, therefore, also be applicable to the de novo design of protein nanostructures.

Expression of Glucocorticoid Receptors GRα and GRß in Bullous Pemphigoid.

First-line treatments of bullous pemphigoid (BP) are topical and systemic glucocorticoids (GC). The actions of GC are mediated by glucocorticoid receptors (GR), which exist in several isoforms, of which GRα and GRß are the most important. In many inflammatory diseases, up-regulation of GRß is associated with GC insensitivity. The aims of this study were to determine the expression of GRα and GRß in patients with BP and to investigate the effect of prednisolone treatment on the expression of GR isoforms in BP. Quantitative real-time PCR (qPCR) analysis demonstrated that GR isoform mRNAs are expressed in peripheral blood mononuclear cells (PBMC) from patients with BP. Expression of GRα and GRß protein was confirmed by immunohistochemical staining of BP skin biopsies and by Western blot analysis and flow cytometric analysis of PBMCs. During prednisolone treatment, GRα and GRß expression varied markedly, but changes were not suitable as a clinical marker of GC sensitivity in patients with BP.

Bypass Surgeries in the Treatment of Cerebral Aneurysms.

BACKGROUND: During surgery for cerebral aneurysm, revascularization techniques are occasionally needed to (1) treat an aneurysm (trapping or flow alteration); (2) preserve blood flow during temporary parent artery occlusion (insurance); and (3) repair accidentally injured vessels (troubleshooting). Herein we present our surgical case experiences. METHODS: Revascularization modalities were employed in 33 (7.6 %) of 452 cases of surgically treated aneurysms. The aneurysm locations and associated required bypass procedures were: (1) 7 middle cerebral artery (MCA) aneurysms with 7 superficial temporal artery (STA)-MCA bypass procedures; (2) 10 internal carotid artery (ICA) aneurysms with 9 high-flow and 1 STA-MCA procedures; (3) 10 vertebro-basilar artery aneurysms with 2 high-flow, 6 occipital artery (OA)-posterior ICA, and 1 STA-superior cerebellar artery (SCA) procedures; (4) 1 posterior cerebral artery (PCA) aneurysm with OA-PCA bypass; and (5) 5 anterior cerebral artery aneurysms with 4 A3-A3 and 1 A3-STA-A3 procedure. Curative bypasses for aneurysmal treatment, temporary bypasses, and troubleshooting procedures were performed in 25, 3, and 5 cases, respectively. RESULTS: Among the 26 aneurysms treated via curative bypass, 16 aneurysms that were trapped or clipped using revascularization techniques had better outcomes (no aneurysmal rupture and 1 perforator infarction), whereas among the 10 aneurysms that could not be trapped or clipped and were thereby treated via flow alteration (e.g., bypass plus proximal artery clipping), 2 developed symptomatic infarction and 2 exhibited aneurysmal rupture after partial thrombosis. Patients whose bypass procedures were used for temporary parent artery occlusion (insurance) or troubleshooting had no complications. CONCLUSION: Complex aneurysm clipping or trapping using bypass techniques yielded good results. In particular, perforator vessel ischemia still requires resolution. Flow alteration techniques leading to aneurismal thrombosis carried the risks of ischemic and hemorrhagic complications when applied to intracranial aneurysms. Bypasses for temporary use or troubleshooting were quite effective.

Asymmetric nitrene transfer reactions: sulfimidation, aziridination and C-H amination using azide compounds as nitrene precursors.

Nitrogen functional groups are found in many biologically active compounds and their stereochemistry has a profound effect on biological activity. Nitrene transfer reactions such as aziridination, C-H bond amination, and sulfimidation are useful methods for introducing nitrogen functional groups, and the enantiocontrol of the reactions has been extensively investigated. Although high enantioselectivity has been achieved, most of the reactions use (N-arylsulfonylimino)phenyliodinane, which co-produces iodobenzene, as a nitrene precursor and have a low atom economy. Azide compounds, which give nitrene species by releasing nitrogen, are ideal precursors but rather stable. Their decomposition needs UV irradiation, heating in the presence of a metal complex, or Lewis acid treatment. The examples of previous azide decomposition prompted us to examine Lewis acid and low-valent transition-metal complexes as catalysts for azide decomposition. Thus, we designed new ruthenium complexes that are composed of a low-valent Ru(II) ion, apical CO ligand, and an asymmetry-inducing salen ligand. With these ruthenium complexes and azides, we have achieved highly enantioselective nitrene transfer reactions under mild conditions. Recently, iridium-salen complexes were added to our toolbox.

Ruthenium-catalyzed oxidative kinetic resolution of unactivated and activated secondary alcohols with air as the hydrogen acceptor at room temperature.

Enantiopure alcohols are versatile building blocks for asymmetric synthesis and the kinetic resolution (KR) of racemic alcohols is a reliable method for preparing them. Although many KR methods have been developed, oxidative kinetic resolution (OKR), in which dioxygen is used as the hydrogen acceptor, is the most atom-efficient. Dioxygen is ubiquitous in air, which is abundant and safe to handle. Therefore, OKR with air has been intensively investigated and the OKR of benzylic alcohols was recently achieved by using an Ir catalyst without any adjuvant. However, the OKR of unactivated alcohols remains a challenge. An [(aqua)Ru(salen)] catalyzed OKR with air as the hydrogen acceptor was developed, in which the aqua ligand is exchanged with alcohol and the Ru complex undergoes single electron transfer to dioxygen and subsequent alcohol oxidation. This OKR can be applied without any adjuvant to activated and unactivated alcohols with good to high enantioselectivity. The unique influence of substrate inhibition on the enantioselectivity of the OKR is also described.

Tandem Kumada-Tamao catalyst-transfer condensation polymerization and Suzuki-Miyaura coupling for the synthesis of end-functionalized poly(3-hexylthiophene).

Successive Kumada-Tamao catalyst-transfer condensation polymerization of 2-bromo-5-chloromagnesio-3-hexylthiophene and Suzuki-Miyaura end-functionalization with pinacol arylboronate in one pot afforded poly(3-hexylthiophene) (P3HT) with a base-sensitive functional group at both ends. The use of poly(methyl methacrylate) (PMMA) bearing a boronic acid ester moiety at one end enabled one-pot synthesis of PMMA-b-P3HT-b-PMMA triblock copolymer.

Aneurysmal Inflow Rate Coefficient Predicts Ultra-early Rebleeding in Ruptured Intracranial Aneurysms: Preliminary Report of a Computational Fluid Dynamics Study.

Rebleeding from a ruptured intracranial aneurysm has poor outcomes. Although numerous factors are associated with rebleeding, studies on computational fluid dynamics (CFD) on hemodynamic parameters associated with early rebleeding are scarce. In particular, no report of rebleeding in ultra-early phase exists. We aimed to elucidate the specific hemodynamic parameters associated with ultra-early rebleeding using CFD. In this study, the rebleeding group included patients with aneurysmal subarachnoid hemorrhage (aSAH) that rebled within 6 h from the onset. The control group included patients without rebleeding, observed for >10 h following the initial rupture. Clinical images after initial rupture and before rebleeding were used to build 3D vessel models for hemodynamic analysis focusing on the following parameters: time-averaged wall shear stress (WSS), normalized WSS, low shear area, oscillatory shear index, relative residence time, pressure loss coefficient, and aneurysmal inflow rate coefficient (AIRC). Five and 15 patients in the rebleeding and control groups, respectively, met the inclusion criteria. The World Federation of Neurosurgical Surgeons grade was significantly higher in the rebleeding group (p = 0.0088). Hemodynamic analysis showed significantly higher AIRC in the rebleeding group (p = 0.042). The other parameters were not significantly different between groups. There were no significant differences or correlations between SAH severity and AIRC. AIRC was identified as a hemodynamic parameter associated with ultra-early rebleeding of ruptured intracranial aneurysms. Thus, AIRC calculation may enable the prediction of ultra-early rebleeding.

Invention of an Online Interactive Virtual Neurosurgery Simulator With Audiovisual Capture for Tactile Feedback.

BACKGROUND: Present neurosurgical simulators are not portable. OBJECTIVE: To maximize portability of a virtual surgical simulator by providing online learning and to validate a unique psychometric method ("audiovisual capture") to provide tactile information without force feedback probes. METHODS: An online interactive neurosurgical simulator of a posterior petrosectomy was developed. The difference in the hardness of compact vs cancellous bone was presented with audiovisual effects as inclinations of the drilling speed and sound based on engineering perspectives. Three training methods (the developed simulator, lectures and review of slides, and dissection of a 3-dimensional printed temporal bone model [D3DPM]) were evaluated by 10 neurosurgical residents. They all first attended a lecture and were randomly allocated to 2 groups by the training D3DPM (A: simulator; B: review of slides, no simulator). In D3DPM, objective measures (required time, quality of completion, injury scores of important structures, and the number of instructions provided) were compared between groups. Finally, the residents answered questionnaires. RESULTS: The objective measures were not significantly different between groups despite a younger tendency in group A (graduate year -2.4 years, 95% confidence interval -5.3 to 0.5, P = .081). The mean perceived hardness of cancellous bone on the simulator was 70% of that of compact bone, matching the intended profile. The simulator was superior to lectures and review of slides in feedback and repeated practices and to D3DPM in adaptability to multiple learning environments. CONCLUSION: A novel online interactive neurosurgical simulator was developed, and satisfactory validity was shown. Audiovisual capture successfully transmitted the tactile information.

De-Identification Technique with Facial Deformation in Head CT Images.

Head CT, which includes the facial region, can visualize faces using 3D reconstruction, raising concern that individuals may be identified. We developed a new de-identification technique that distorts the faces of head CT images. Head CT images that were distorted were labeled as "original images" and the others as "reference images." Reconstructed face models of both were created, with 400 control points on the facial surfaces. All voxel positions in the original image were moved and deformed according to the deformation vectors required to move to corresponding control points on the reference image. Three face detection and identification programs were used to determine face detection rates and match confidence scores. Intracranial volume equivalence tests were performed before and after deformation, and correlation coefficients between intracranial pixel value histograms were calculated. Output accuracy of the deep learning model for intracranial segmentation was determined using Dice Similarity Coefficient before and after deformation. The face detection rate was 100%, and match confidence scores were < 90. Equivalence testing of the intracranial volume revealed statistical equivalence before and after deformation. The median correlation coefficient between intracranial pixel value histograms before and after deformation was 0.9965, indicating high similarity. Dice Similarity Coefficient values of original and deformed images were statistically equivalent. We developed a technique to de-identify head CT images while maintaining the accuracy of deep-learning models. The technique involves deforming images to prevent face identification, with minimal changes to the original information.

Reproducibility of Facial Information in Three-Dimensional Reconstructed Head Images: An Exploratory Study.

BACKGROUND: Facial information acquired via three-dimensional reconstruction of head computed tomography (CT) data may be considered personal information, which can be problematic for neuroimaging studies. However, no study has verified the relationship between slice thickness and face reproducibility. This study determined the relationship and match rate between image slice thickness and face detection accuracy of face-recognition software in facial reconstructed models. METHODS: Head CT data of 60 cases comprising entire faces obtained under conditions of non-contrast and 1-mm slice thickness were resampled to obtain 2-10-mm slice-thickness data. Facial models, reconstructed by image thresholding, were acquired from the data. We performed face detection tests per slice thickness on the models and calculated the face detection rate. The reconstructed facial models created from 1-mm slice-thickness data and other slice thicknesses were used as training and test data, respectively. Match confidence scores were obtained via three programs, match rates were calculated per slice thickness, and generalized estimating equations were used to evaluate the match rate trend. RESULTS: In general, the face detection rates for the 1-10-mm slice thicknesses were 100, 100, 98.3, 98.3, 95.0, 91.7, 86.7, 78.3, 68.3, and 61.7 %, respectively. The match rates for the 2-10-mm slice thicknesses were 100, 98.3, 98.3, 95.0, 85.0, 71.7, 53.3, 28.3, and 16.7 %, respectively. CONCLUSION: The reconstructed models tended to have higher match rates as the slice thickness decreased. Thus, thin-slice head CT imaging data may increase the possibility of the information becoming personally identifiable health information.

Matrix metalloproteinase levels in peritoneal effluents were increased in a patient with appendicitis undergoing continuous ambulatory peritoneal dialysis.

A differential diagnosis of common bacterial peritonitis and appendicitis is difficult in continuous ambulatory peritoneal dialysis (CAPD) patients, and thus the definite diagnosis of appendicitis is often delayed. In this case, a 60-year-old man undergoing CAPD was at first diagnosed with bacterial peritonitis but not appendicitis, and antibiotics were administered. The number of leukocytes in the peritoneal effluent decreased mildly, but the level of C-reactive protein continued to be high and the pain aggravated. When the catheter was removed, suppurative appendicitis was confirmed for the first time. Levels of matrix metalloproteinase (MMP)-2 and -9 in peritoneal effluents were markedly high. Appendicitis should be diagnosed as early as possible because MMPs directly injure the peritoneum via degradation of extracellular matrix proteins. Future studies in a greater numbers of cases of appendicitis are required.

Synthesis of natural product hybrids by the Ugi reaction in complex media containing plant extracts.

Plant extracts are rich in a wide variety of molecules with diverse biological activities. Chemical engineering of plant extracts has provided a straightforward and simultaneous synthetic route for artificial molecules derived from plant products. This study achieved the synthesis of 13 natural product-like molecules by the Ugi multicomponent reaction using plant extracts as substrates. In particular, the engineering of a mixture of plant extracts demonstrated a unique synthetic route to a series of natural product hybrids, whereby otherwise unencountered naturally occurring molecules of different origins were chemically hybridized in complex media. Even though these reactions took place in complex media containing plant extracts, the well-designed process achieved a good conversion efficiency (~ 60%), chemoselectivity, and reproducibility. Additionally, some of the Ugi adducts exhibited promising inhibitory activity toward protease.

Endoscopic Transnasal Resection of Trigeminal Schwannoma.

Trigeminal schwannoma is a rare skull base tumor that can be managed in a variety of treatments including image observation, surgery, stereotactic radiosurgery, such as gamma knife radiosurgery (GKS), and combination of these. Endoscopic transnasal resection is very effective when the tumor is not invading far laterally, or the risk of cerebrospinal fluid (CSF) leak is estimated to be low. A 74-year-old man with a history of prostate cancer and diabetes presented with left oculomotor nerve palsy over a month. Magnetic resonance images (MRI) demonstrated a 25-mm mass in the left cavernous sinus protruding to the left orbit via the superior orbital fissure ( Fig. 1 ). The patient underwent endoscopic transnasal surgery to decompress the mass. The surgery was uneventful, and postoperative MRI demonstrated satisfactory subtotal resection of the mass ( Fig. 2 ). The final pathology returned as schwannoma. At 1-year follow-up, the tumor slowly enlarged, and the patient underwent GKS with a marginal dose of 14 Gy. At the last follow-up, 4 months after GKS, the tumor was stable. Unfortunately the patient deceased from the known prostate cancer. Endoscopic transnasal surgery was especially useful in this case, considering the preoperative known cancer state that management of this benign tumor did not ruin the quality of life of this patient while minimizing hospitalization, as achieving satisfactory tumor control with aid from postoperative GKS, minimizing complications. The link to the video can be found at: https://youtu.be/Q0Ugc2VFV4w .

Accurate Preoperative Identification of Motor Speech Area as Termination of Arcuate Fasciculus Depicted by Q-Ball Imaging Tractography.

BACKGROUND: Tractography is one way to predict the distribution of cortical functional domains preoperatively. Diffusion tensor tractography (DTT) is commonly used in clinical practice, but is known to have limitations in delineating crossed fibers, which can be overcome by Q-ball imaging tractography (QBT). We aimed to compare the reliability of these 2 methods based on the spatial correlation between the arcuate fasciculus depicted by tractography and direct cortical stimulation during awake surgery. METHODS: In this study, 15 patients with glioma underwent awake surgery with direct cortical stimulation. Tractography was depicted in a three-dimensional computer graphic model preoperatively, which was integrated with a photograph of the actual brain cortex using our novel mixed-reality technology. The termination of the arcuate fasciculus depicted by either DTT or QBT and the results of direct cortical stimulation were compared, and sensitivity and specificity were calculated in speech-associated brain gyri: pars triangularis, pars opercularis, ventral precentral gyrus, and middle frontal gyrus. RESULTS: QBT had significantly better sensitivity and lower false-positive rate than DTT in the pars opercularis. The same trend was noted for the other gyri. CONCLUSIONS: QBT is more reliable than DTT in identification of the motor speech area and may be clinically useful in brain tumor surgery.