PTCH1 mutation as a potential predictive biomarker for immune checkpoint inhibitors in gastrointestinal cancer.

Immune checkpoint inhibitors (ICIs) have become prominent therapies for gastrointestinal cancer (GC). However, it is urgent to screen patients who can benefit from ICIs. Protein patched homolog 1 (PTCH1) is a frequently altered gene in GC. We attempt to explore the association between PTCH1 mutation and immunotherapy efficacy. The Memorial Sloan Kettering Cancer Center (MSKCC) cohort (n = 236) with GC (esophageal, gastric and colorectal cancers) patients receiving ICIs was used for discovery and the Peking University Cancer Hospital (PUCH) GC cohort (n = 92) was used for validation. Overall survival (OS) and tumor mutational burden (TMB) of the PTCH1 mutant-type (PTCH1-MUT) and PTCH1 wild-type (PTCH1-WT) groups were compared. Furthermore, GC data were collected from The Cancer Genome Atlas to assess the potential mechanisms. In the MSKCC cohort, PTCH1-MUT group showed significantly better OS (P = 0.017) and higher TMB. Multivariate analysis showed that PTCH1 mutation was associated with better OS. In the PUCH cohort, PTCH1-MUT group showed significantly longer OS (P = 0.036) and progression-free survival, and higher durable clinical benefit and TMB. Immune cell infiltration analysis revealed that PTCH1-MUT group had significantly higher distributions of CD8 T cells, CD4 T cells, NK cells, mast cells and M1 cells. The PTCH1-MUT group showed significantly higher expression of most immune-related genes. Gene set enrichment analysis showed that the PTCH1-MUT group had enriched INF-γ response, INF-α response, glycolysis and reactive oxygen species pathway gene sets. PTCH1 mutation may represent a potential biomarker for predicting ICIs response in GC. Nevertheless, prospective cohort studies should be performed to further validate our results.

The first case of Odoribacter splanchnicus bacteremia isolated from a patient in China.

Background: Odoribacter splanchnicus is an extremely rare pathogen of human infection. This case reports bacteremia infection of O. splanchnicus, which is highly likely to result in misdiagnosis if inappropriate diagnostic method are used. Case presentation: A 29-year-old Chinese male patient with no underlying disease was hospitalized twice for injuries caused by a car accident. During the second hospitalization, abdominal surgery was performed and high fever developed after the surgery. A strain of O. splanchnicus was isolated from the blood and confirmed by MALDI-TOF-MS and 16S rRNA gene analysis. Finally, the patient recovered successfully by using antibiotics, fluid replacement and albumin input. Conclusions: This is the first case of O. splanchnicus bacteremia in China. We present a brief review of the cases concerning O. splanchnicus infection in humans. O. splanchnicus, as part of the normal intestinal flora, is well known for its anti-tumor and immune regulating properties, it is rarely isolated from clinical samples. This case illustrates the potential of O. splanchnicus as a pathogen and suggests attention to the use of new and advanced methods like MALDI-TOF MS and 16S rRNA gene sequencing to identify rarely isolated species from clinical samples.

Kosakonia radicincitans with hypervirulent lON genes causes human bloodstream infections.

Kosakonia radicincitans is a species within the new genus Kosakonia, which is typically a plant pathogen, with rare reports of human infection. The number of human infections may be underestimated because this new genus is under-represented among diagnostic tools. This report describes a case of bloodstream infection caused by K. radicincitans. The pathogen was identified by matrix-assisted laser desorption/ionization-TOF mass spectrometry and 16S rRNA gene sequencing. The hypervirulent human pathogenicity gene LON, which has not been described before, was detected in the bacterial genome by gene annotation. Thus, this discovery provides a new reference for studying the pathogenic mechanism of this rare pathogen.

Identification of the molecular characteristics associated with microsatellite status of colorectal cancer patients for the clinical application of immunotherapy.

Background: Mismatch repair-proficient (pMMR) microsatellite stability (MSS) in colorectal cancer (CRC) indicates an unfavorable therapeutic response to immunotherapy with immune checkpoint inhibitors (ICIs). However, the molecular characteristics of CRC patients with pMMR MSS remain largely unknown. Methods: Heterogeneities between mismatch repair-deficient (dMMR) microsatellite instability (MSI) and pMMR MSS CRC patients were investigated at the single-cell level. Next, an MSS-related risk score was constructed by single-sample gene set enrichment analysis (ssGSEA). The differences in immune and functional characteristics between the high- and low-score groups were systematically analyzed. Results: Based on the single-cell RNA (scRNA) atlas, an MSS-specific cancer cell subpopulation was identified. By taking the intersection of the significant differentially expressed genes (DEGs) between different cancer cell subtypes of the single-cell training and validation cohorts, 29 MSS-specific cancer cell marker genes were screened out for the construction of the MSS-related risk score. This risk score signature could efficiently separate pMMR MSS CRC patients into two subtypes with significantly different immune characteristics. The interactions among the different cell types were stronger in the MSS group than in the MSI group, especially for the outgoing signals of the cancer cells. In addition, functional differences between the high- and low-score groups were preliminarily investigated. Conclusion: In this study, we constructed an effective risk model to classify pMMR MSS CRC patients into two completely different groups based on the specific genes identified by single-cell analysis to identify potential CRC patients sensitive to immunotherapy and screen effective synergistic targets.

Fate of PAHs in treated wastewater reused as irrigation water: Environmental risks in water-soil-ryegrass multimedia system.

The main aim of this study was to determine the fate, bio-metabolism and environmental risk of low-ring and high-ring polycyclic aromatic hydrocarbons (PAHs) in a water-soil-ryegrass multi-media system, under long-term irrigation condition with micro-polluted treated wastewater. Field experiments were carried out to simulate garden irrigation using treated wastewater containing typical representative low-ring naphthalene (Nap) and high-ring benzo[a]pyrene (BaP). The results showed that BaP's vertical attenuation rate and adsorption accumulation rate were 1.7 and 1.2 times higher than Nap's, respectively. The adsorption, biodegradation, and the rhizosphere effect were responsible for 40.7%, 28.4%, 21.6%, and 30.5%, 36.6%, 17.7%, respectively, of the attenuation of BaP and Nap. The major metabolic pathways of Nap and BaP are hydroxylation, ring opening cleavage, and decarboxylation, with the metabolic chain of BaP being longer than that of Nap due to more ring cleaving reactions. Pseudomonas, Mycobacterium, and Sphingomonas were the functional microorganisms with PAHs degradation capacity that were positively correlated with PAHs degradation, particularly in the rhizosphere. After ten years of irrigation with treated wastewater, the prediction of environmental risk revealed that there were few potential risks. Thus, the results of this feasibility study demonstrated that using treated wastewater for garden irrigation was a relatively safe and effective strategy.

Eggerthella lenta bacteremia successfully treated with ceftizoxime: case report and review of the literature.

Eggerthella lenta is a normal human microflora that is anaerobic, non-sporulating, and Gram positive. However, an increasing number of studies have shown that it could also be an important pathogen for humans, even causing life-threatening infection under certain conditions. However, understanding its pathogenic mechanism and treatment options still need to be improved; more clinical data are needed to explore it further. In this article, we report a case of ceftizoxime-cured E. lenta bacteremia and review the recent literature to provide more clinical data for the diagnosis of E. lenta bacteremia. Our report suggests that the frequency of E. lenta bacteremia is increased in patients with hematologic or solid organ cancer, diabetes mellitus and also in those with appendicitis.

Enhancement in serum (1-3)-ß-D-glucan level by cutaneous alternariosis: A case report and literature review.

Contamination with the fungus Alternaria spp. is often considered to have originated from laboratory sources, which occasionally causes infection in immunocompromised patients, termed as phaeohyphomycosis. Here, we have reported a case of cutaneous alternariosis caused by Alternaria alternata. This diagnosis was based on microscopic examination and mycological culturing of patient's vesicular lesions, with the use of 5 molecular markers (namely, ITS, ATPase, Actin, rpb2, and tef1) for strain identification. We noted that Alternaria infection caused an increase in the serum level of (1-3)-ß-D-glucan (BG) in the patients. To the best of our knowledge, no such finding has been reported in previously in the literature.

A new class of highly potent and selective endomorphin-1 analogues containing α-methylene-ß-aminopropanoic acids (map).

A new class of endomorphin-1 (EM-1) analogues were synthesized by introduction of novel unnatural α-methylene-ß-amino acids (Map) at position 3 or/and position 4. Their binding and functional activity, metabolic stability, and antinociceptive activity were determined and compared. Most of these analogues showed high affinities for the µ-opioid receptor and an increased stability in mouse brain homogenates compared with EM-1. Examination of cAMP accumulation and ERK1/2 phosphorylation in HEK293 cells confirmed the agonist properties of these analogues. Among these new analogues, H-Tyr-Pro-Trp-(2-furyl)Map-NH(2) (analogue 12) exhibited the highest binding potency (K(i)(µ) = 0.221 nM) and efficacy (EC(50) = 0.0334 nM, E(max) = 97.14%). This analogue also displayed enhanced antinociceptive activity in vivo in comparison to EM-1. Molecular modeling approaches were then carried out to demonstrate the interaction pattern of these analogues with the opioid receptors. We found that, compared to EM-1, the incorporation of our synthesized Map at position 4 would bring the analogue to a closer binding mode with the µ-opioid receptor.

Highly enantioselective Friedel-Crafts alkylation reaction catalyzed by rosin-derived tertiary amine-thiourea: synthesis of modified chromanes with anticancer potency.

We present herein for the first time the synthesis and preliminary biological evaluation of various modified chromanes via a rosin-derived tertiary amine-thiourea-catalyzed highly enantioselective Friedel-Crafts alkylation reaction.

The N-terminal domain of human hemokinin-1 influences functional selectivity property for tachykinin receptor neurokinin-1.

Human hemokinin-1 (hHK-1) is a substance P-like tachykinin peptide preferentially expressed in non-neuronal tissues. It is involved in multiple physiological functions such as inflammation, hematopoietic cells development and vasodilatation via the interaction with tachykinin receptor neurokinin-1 (NK1). To further understand the intracellular signal transduction mechanism under such functional multiplicity, current study was focused on the differential activation of Gs and Gq pathways by hHK-1 and its C-terminal fragments, which is termed as functional selectivity. We demonstrated these hHK-1 and related peptide fragments can independently activate Gs and Gq pathways, showing a relative bias toward Gq over Gs pathway. The T1, K3 and Q6 of hHK-1 might play roles in the activation of adenylate cyclase mediated by Gs, while having negligible effect on Gq mediated intracellular calcium release. The stepwise truncation of N-terminal amino acid of hHK-1 caused gradual decrease in ERK1/2 phosphorylation level and NF-κB activity. However, it had little influence on the induction of NK1 receptor desensitization and internalization. Taken together these data support that hHK-1 and its C-terminal fragments are human NK1 receptor agonists with different functional selectivity properties and that such functional selectivity leads to differential activation of downstream signaling and receptor trafficking.