Machine Learning of Histopathological Images Predicts Recurrences of Resected Pancreatic Ductal Adenocarcinoma With Adjuvant Treatment.

OBJECTIVES: Pancreatic ductal adenocarcinoma is an intractable disease with frequent recurrence after resection and adjuvant therapy. The present study aimed to clarify whether artificial intelligence-assisted analysis of histopathological images can predict recurrence in patients with pancreatic ductal adenocarcinoma who underwent resection and adjuvant chemotherapy with tegafur/5-chloro-2,4-dihydroxypyridine/potassium oxonate. MATERIALS AND METHODS: Eighty-nine patients were enrolled in the study. Machine-learning algorithms were applied to 10-billion-scale pixel data of whole-slide histopathological images to generate key features using multiple deep autoencoders. Areas under the curve were calculated from receiver operating characteristic curves using a support vector machine with key features alone and by combining with clinical data (age and carbohydrate antigen 19-9 and carcinoembryonic antigen levels) for predicting recurrence. Supervised learning with pathological annotations was conducted to determine the significant features for predicting recurrence. RESULTS: Areas under the curves obtained were 0.73 (95% confidence interval, 0.59-0.87) by the histopathological data analysis and 0.84 (95% confidence interval, 0.73-0.94) by the combinatorial analysis of histopathological data and clinical data. Supervised learning model demonstrated that poor tumor differentiation was significantly associated with recurrence. CONCLUSIONS: Results indicate that machine learning with the integration of artificial intelligence-driven evaluation of histopathological images and conventional clinical data provides relevant prognostic information for patients with pancreatic ductal adenocarcinoma.

A case of percutaneous transhepatic portal vein stenting without using iodinated contrast media for post pancreatectomy portal vein obstruction.

Postoperative portal vein obstruction could occur as a complication of portal vein reconstruction during hepatic lobectomy or pancreaticoduodenectomy. We report a case of patient with postoperative portal vein obstruction treated with percutaneous transhepatic portal vein stenting without using iodinated contrast media owing to a history of severe allergic reactions. Under ultrasound guidance, carbon dioxide angiography, and appropriate device selection, successful stenting was achieved without serious adverse events. After the operation, portal vein blood flow and clinical symptoms improved, enabling adjuvant chemotherapy. To the best of our knowledge, this is the first case report wherein percutaneous transhepatic portal vein stenting was successfully performed in a patient with an iodine allergy.

Collagen gel droplet-embedded culture drug sensitivity test (CD-DST) predicts the effect of adjuvant chemotherapy on pancreatic cancer.

PURPOSE: We evaluated the clinical effectiveness of collagen gel droplet-embedded culture drug sensitivity tests (CD-DSTs) in predicting the efficacy of adjuvant chemo-therapeutic treatments for pancreatic cancer (PC). METHODS: The clinicopathological characteristics and prognoses of 22 PC patients who underwent CD-DST after pancreatectomy at Tohoku University between 2012 and 2016 were analyzed retrospectively. Eligibility criteria were resectable or borderline resectable PC, successful evaluation for 5-fluorouracil sensitivity by CD-DST, treatment with S-1 adjuvant chemotherapy, and no preoperative chemotherapy. RESULTS: The rate of successful evaluation by CD-DST was 52.3% in PC. The optimal T/C ratio, defined as the ratio of the number of cancer cells in the treatment group (T) to that in the control group (C), for 5-fluorouracil was 85% using receiver operating characteristic curve analysis. The sensitive group (T/C ratio < 85%; n = 11) had a better recurrence-free survival rate than the resistant group (T/C ratio ≥ 85%; n = 11; P = 0.029). A Cox proportional hazards regression model demonstrated that sensitivity to 5-fluorouracil was an independent predictor of recurrence on multivariate analysis (hazard ratio 3.28; 95.0% CI 1.20-9.84; P = 0.020). CONCLUSIONS: CD-DSTs helped to predict PC recurrence after S-1 adjuvant chemotherapy.

Neuromagnetic evaluation of a communication support system for hearing-impaired patients.

Hearing-impaired patients often encounter obstacles in communication. Not all of them wear hearing aids, citing issues with usage difficulty and discomfort in wearing. To overcome these difficulties, a new endeavor was started to improve sound intelligibility from the speaker's side. The present study objectively evaluated an intelligible-hearing (IH) loudspeaker by means of magnetoencephalography. Magnetic counterparts of mismatch negativity (MMNm) to pronunciation ('mi' and 'ni') were recorded and compared when they were transmitted from the IH loudspeaker and from a normal-hearing loudspeaker. On using the IH loudspeaker, the peak latency was found to be significantly shortened. In the case of hearing-impaired participants, marked MMNm responses were observed only when the IH loudspeaker was used. These findings suggest that improving sound intelligibility may be a supportive and rehabilitative approach for hearing-impaired patients.

Inhibition in the Human Auditory Cortex.

Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI) in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observed by inserting a weak (5 dB increase for 1 ms) prepulse. The time course of the inhibition evaluated by prepulses presented at 10-800 ms before the test stimulus showed at least two temporally distinct inhibitions peaking at approximately 20-60 and 600 ms that presumably reflected IPSPs by fast spiking, parvalbumin-positive cells and somatostatin-positive, Martinotti cells, respectively. In another experiment, we confirmed that the degree of the inhibition depended on the strength of the prepulse, but not on the amplitude of the prepulse-evoked cortical response, indicating that the prepulse-evoked excitatory response and prepulse-evoked inhibition reflected activation in two different pathways. Although many diseases such as schizophrenia may involve deficits in the inhibitory system, we do not have appropriate methods to evaluate them; therefore, the easy and non-invasive method described herein may be clinically useful.

Microchannel emulsification using gelatin and surfactant-free coacervate microencapsulation.

In this study, we investigated the use of microchannel (MC) emulsifications in producing monodisperse gelatin/acacia complex coacervate microcapsules of soybean oil. This is considered to be a novel method for preparing monodisperse O/W and W/O emulsions. Generally, surfactants are necessary for MC emulsification, but they can also inhibit the coacervation process. In this study, we investigated a surfactant-free system. First, MC emulsification using gelatin was compared with that using decaglycerol monolaurate. The results demonstrated the potential use of gelatin for MC emulsification. MC emulsification experiments conducted over a range of conditions revealed that the pH of the continuous phase should be maintained above the isoelectric point of the gelatin. A high concentration of gelatin was found to inhibit the production of irregular-sized droplets. Low-bloom gelatin was found to be suitable for obtaining monodisperse emulsions. Finally, surfactant-free monodisperse droplets prepared by MC emulsification were microencapsulated with coacervate. The microcapsules produced by this technique were observed with a confocal laser scanning microscope. Average diameters of the inner cores and outer shells were 37.8 and 51.5 microm; their relative standard deviations were 4.9 and 8.4%.