Machine learning approaches are widely used to evaluate ligand activities of chemical compounds toward potential target proteins. Especially, exploration of highly selective ligands is important for the development of new drugs with higher safety. One difficulty in constructing well‐performing model predicting such a ligand activity is the absence of data on true negative ligand‐protein interactions. In other words, in many cases we can access to plenty of information on ligands that bind to specific protein, but less or almost no information showing that compounds don't bind to proteins of interest. In this paper, we suggested an approach to comprehensively explore candidates for ligands specifically targeting toward proteins without using information on the true negative interaction. The approach consists of 4 steps: 1) constructing a model that distinguishes ligands for the target proteins of interest from those targeting proteins that cause off‐target effects, by using graph convolution neural network (GCNN); 2) extracting feature vectors after convolution/pooling processes and mapping their principal components in two dimensions; 3) specifying regions with higher density for two ligand groups through kernel density estimation; and 4) investigating the distribution of compounds for exploration on the density map using the same classifier and decomposer. If compounds for exploration are located in higher‐density regions of ligand compounds, these compounds can be regarded as having relatively high binding affinity to the major target or off‐target proteins compared with other compounds. We applied the approach to the exploration of ligands for β‐site amyloid precursor protein [APP]‐cleaving enzyme 1 (BACE1), a major target for Alzheimer Disease (AD), with less off‐target effect toward cathepsin D. We demonstrated that the density region of BACE1 and cathepsin D ligands are well‐divided, and a group of natural compounds as a target for exploration of new drug candidates also has significantly different distribution on the density map.
Aldo-keto reductase family 1 member C3 (AKR1C3) is an enzyme in the steroidogenesis pathway, especially in formation of testosterone and dihydrotestosterone, and is believed to have a key role in promoting prostate cancer (PCa) progression, particularly in castration-resistant prostate cancer (CRPC). This study aims to compare the expression level of AKR1C3 between benign prostatic epithelium and cancer cells, and among hormone-naïve prostate cancer (HNPC) and CRPC from the same patients, to understand the role of AKR1C3 in PCa progression. Correlation of AKR1C3 immunohistochemical expression between benign and cancerous epithelia in 134 patient specimens was analyzed. Additionally, correlation between AKR1C3 expression and prostate-specific antigen (PSA) progression-free survival (PFS) after radical prostatectomy was analyzed. Furthermore, we evaluated the consecutive prostate samples derived from 11 patients both in the hormone-naïve and castration-resistant states. AKR1C3 immunostaining of cancer epithelium was significantly stronger than that of the benign epithelia in patients with localized HNPC (p < 0.0001). High AKR1C3 expression was an independent factor of poor PSA PFS (p = 0.032). Moreover, AKR1C3 immunostaining was significantly stronger in CRPC tissues than in HNPC tissues in the same patients (p = 0.0234). Our findings demonstrate that AKR1C3 is crucial in PCa progression.
RotaTeq (RV5) is a widely used live attenuated pentavalent rotavirus (RV) vaccine. Although fecal shedding of RV vaccine strains persists for long time periods, it is unclear how each vaccine strain replicates in intestinal tissue and is excreted in stool. To examine this issue, we established RV5 genotype-specific real-time reverse transcription-PCR (RT-PCR) assays. Five real-time RT-PCR assays were designed for the VP7 gene in genotypes G1, G2, G3, G4, and G6. All assays exhibited excellent linearity, and the detection limit was 1 infectious unit (IU)/reaction for G2, G4, and G6 and 10 IUs/reaction for G1 and G3. No cross-reactivity was observed among G genotypes. The inter- and intra-assay coefficients of variation were less than 3%. The assays were used to examine 129 stool samples collected from eight infants who received RV5. In cases 1 and 2, who received three rounds of vaccination, RV shedding decreased gradually with the number of vaccinations. G1 and G6 shedding appeared to be predominant in comparison to shedding of the other genotypes. Patterns of fecal shedding of the five genotypes of vaccine viruses differed between the eight vaccine recipients. RV5 genotype-specific real-time RT-PCR assays will be useful to study the molecular biology of RV5 replication in infants and experimental animals.
Although spinal cord stimulation has been reported to be effective for controlling neuropathic pain in diabetic neuropathy, it has rarely been investigated in other peripheral neuropathies. We describe, for the first time, the efficacy of spinal cord stimulation for refractory neuropathic pain in a patient with transthyretin Val30Met associated familial amyloid polyneuropathy (FAP ATTR Val30Met). A 72-year-old man was diagnosed as having FAP ATTR Val30Met when he was 70 years old. He had been complained of burning pain in the distal portion of his bilateral lower limbs since he was 69 years old. Because conventional symptomatic therapies, including nonsteroidal anti-inflammatory drugs, antiepileptic drugs, and tricyclic antidepressants did not ameliorate pain, he underwent bilateral lumbar spinal cord electrical stimulation at high frequency and low voltage at the level of Th12 vertebral body and this was markedly effective. Our case expands the application of spinal cord stimulation, which should be considered as an alternative therapeutic approach for relief of neuropathic pain, which can be extremely distressful for patients and may lead to an impaired quality of life.
Nobiletin and tangeretin (NoT) are flavonoids derived from the peel of Citrus depressa, and they have been found to modulate circadian rhythms. Because nocturia can be considered a circadian rhythm disorder, we investigated the efficacy of NoT for treating nocturia. A randomized, placebo-controlled, double-blind, crossover study was conducted. The trial was registered with the Japan Registry of Clinical Trials (jRCTs051180071). Nocturia patients aged ≥50 years who presented nocturia more than 2 times on a frequency–volume chart were recruited. Participants received NoT or a placebo (50 mg once daily for 6 weeks), followed by a washout period of ≥2 weeks. The placebo and NoT conditions were then switched. Changes in nocturnal bladder capacity (NBC) were the primary endpoint, and changes in nighttime frequency and nocturnal polyuria index (NPi) were secondary endpoints. Forty patients (13 women) with an average age of 73.5 years were recruited for the study. Thirty-six completed the study, while four withdrew. No adverse events directly related to NoT were observed. NoT had little effect on NBC compared with the placebo. In contrast, NoT significantly changed nighttime frequency by −0.5 voids compared with the placebo (p = 0.040). The change in NPi from baseline to the end of NoT was significant (−2.8%, p = 0.048). In conclusion, NoT showed little change in NBC but resulted in decreased nighttime frequency with a tendency toward reduced NPi.