Gut microbiota and clinical response to immune checkpoint inhibitor therapy in patients with advanced cancer.

BACKGROUND: There is currently no well-accepted consensus on the association between gut microbiota and the response to treatment of immune checkpoint inhibitors (ICIs) in patients with advanced cancer. METHODS: Fecal samples were collected before ICI treatment. Gut microbiota was analyzed using 16 S ribosomal RNA sequencing. We investigated the relationship between the α-diversity of fecal microbiota and patients' clinical outcomes. Microbiota profiles from patients and healthy controls were determined. Pre-treatment serum was examined by cytokine array. RESULTS: We analyzed 74 patients, including 42 with melanoma, 8 with kidney cancer, 13 with lung cancer, and 11 with other cancers. Combination therapy of anti-PD1 and anti-CTLA-4 was used in 14 patients, and monotherapy in the rest. Clinical benefit was observed in 35 (47.3 %) cases, including 2 complete responses, 16 partial responses, and 17 stable diseases according to RECIST criteria. No significant difference in α-diversity was found between the benefiter and non-benefiter groups. However, patients with α-diversity within the range of our healthy control had a significantly longer median overall survival (18.9 months), compared to the abnormal group (8.2 months) (p = 0.041, hazard ratio = 0.546) for all patients. The microbiota composition of the benefiters was similar to that of healthy individuals. Furthermore, specific bacteria, such as Prevotella copri and Faecalibacterium prausnitzii, were associated with a favorable outcome. We also observed that serum IL-18 before treatment was significantly lower in the benefiters, compared to non-benefiters. CONCLUSIONS: The α-diversity of gut microbiota is positively correlated with more prolonged overall survival in cancer patients following ICI therapy.

Repeated centrifuging and washing concentrates bacterial samples in peritoneal dialysis for optimal culture: an original article.

BACKGROUND: Bacterial cultures allow the identification of infectious disease pathogens. However, obtaining the results of conventional culture methods is time-consuming, taking at least two days. A more efficient alternative is the use of concentrated bacterial samples to accelerate culture growth. Our study focuses on the development of a high-yield sample concentrating technique. RESULTS: A total of 71 paired samples were obtained from patients on peritoneal dialysis (PD). The peritoneal dialysates were repeat-centrifuged and then washed with saline, namely the centrifuging and washing method (C&W method). The concentrated samples were Gram-stained and inoculated into culture plates. The equivalent unprocessed dialysates were cultured as the reference method. The times until culture results for the two methods were compared. The reference method yielded no positive Gram stain results, but the C&W method immediately gave positive Gram stain results for 28 samples (p < 0.001). The culture-negative rate was lower in the C&W method (5/71) than in the reference method (13/71) (p = 0.044). The average time for bacterial identification achieved with the C&W method (22.0 h) was shorter compared to using the reference method (72.5 h) (p < 0.001). CONCLUSIONS: The C&W method successfully concentrated bacterial samples and superseded blood culture bottles for developing adequate bacterial cultures. The C&W method may decrease the culture report time, thus improving the treatment of infectious diseases.

Longer dialysis times are associated with a lower chance of dementia among chronic hemodialysis patients.

Dementia is common in chronic hemodialysis (HD) patients and is associated with a higher mortality. Factors associated with dementia in HD patients are not clear. We investigated factors associated with early dementia in HD patients. Chronic HD patients of 27 hemodialysis centers were enrolled in 2013. Early dementia was identified using the AD8 assessment. Factors associated with early dementia were analyzed using logistic regression. A total of 1617 chronic HD patients including 820 males and 797 females, aged 63.3 ± 13 years, dialyzed for 4 (1.8-8.4) years were analyzed. Early dementia was identified in 414 (25.6%) of the patients. Longer HD times were associated with a lower chance of dementia (P = 0.032), with an adjusted odds ratio (OR) of 0.522 (95% confidence interval [CI]: 0.270-0.969) for every one more hour of HD. Patient's age (OR: 1.587, 95% CI: 1.406-1.791, P < 0.001), body mass index (OR: 0.958, 95% CI: 0.921-0.996, P = 0.031), cerebrovascular accident (OR: 1.480, 95% CI: 1.000-2.188), diabetes (OR: 1.894, 95% CI: 1.390-2.581, P < 0.001), and serum albumin (OR: 0.376, 95 % CI: 0.256-0.553, P < 0.001) were independently linked to early dementia. Short hemodialysis times are associated with early dementia in a chronic hemodialysis population with a quarter of patients having early dementia. Patients' age, nutrition status and comorbidity are independently linked to early dementia.

Nutritional status of vegetarians on maintenance haemodialysis.

AIM: Vegetarian diets have long been thought of as beneficial to health. However, vegetarian diets are often low in protein, which is contradictory to the high protein diet guideline for uraemia patients. The purpose of the study was to investigate the impact of a vegetarian diet on the nutritional status of haemodialysis (HD) patients. METHODS: Patients on chronic HD for over 6 months were included in the study. The normalized protein catabolic rate (nPCR) was used to reflect daily protein intake. Biochemical markers of nutrition, anthropometric parameters, subjective global assessment (SGA) and functional activity of daily living were assessed to evaluate the nutritional status of vegetarians on chronic HD. RESULTS: Nineteen out of 318 HD patients were vegetarians. The nPCR was lower in the vegetarian group (1.20 ± 0.24 vs 1.10 ± 0.29 g/kg per day, non-Veg vs Veg, P < 0.05). The serum albumin and prealbumin were similar in vegetarian and non-vegetarian HD patients. The body mass index (BMI) and mid-arm muscular circumference (MAMC) were lower in vegetarian patients (P < 0.05). The haematocrit of vegetarians can be maintained at a level similar to that of non-vegetarian patients but erythropoietin doses needed were higher in vegetarian patients (P < 0.05). The muscle strength evaluated by the hand-grip test, SGA and activities of daily living were similar in vegetarians and non-vegetarians. CONCLUSION: The present study revealed that HD patients on vegetarian diets might have a smaller BMI, but SGA and function of daily activities were similar to those of the non-vegetarians. The haematocrit of vegetarians can be maintained with a higher erythropoietin dose.

The structure of Dasatinib (BMS-354825) bound to activated ABL kinase domain elucidates its inhibitory activity against imatinib-resistant ABL mutants.

Chronic myeloid leukemia (CML) is caused by the constitutively activated tyrosine kinase breakpoint cluster (BCR)-ABL. Current frontline therapy for CML is imatinib, an inhibitor of BCR-ABL. Although imatinib has a high rate of clinical success in early phase CML, treatment resistance is problematic, particularly in later stages of the disease, and is frequently mediated by mutations in BCR-ABL. Dasatinib (BMS-354825) is a multitargeted tyrosine kinase inhibitor that targets oncogenic pathways and is a more potent inhibitor than imatinib against wild-type BCR-ABL. It has also shown preclinical activity against all but one of the imatinib-resistant BCR-ABL mutants tested to date. Analysis of the crystal structure of dasatinib-bound ABL kinase suggests that the increased binding affinity of dasatinib over imatinib is at least partially due to its ability to recognize multiple states of BCR-ABL. The structure also provides an explanation for the activity of dasatinib against imatinib-resistant BCR-ABL mutants.

Discovery of aminothiazole inhibitors of cyclin-dependent kinase 2: synthesis, X-ray crystallographic analysis, and biological activities.

High throughput screening identified 2-acetamido-thiazolylthio acetic ester 1 as an inhibitor of cyclin-dependent kinase 2 (CDK2). Because this compound is inactive in cells and unstable in plasma, we have stabilized it to metabolic hydrolysis by replacing the ester moiety with a 5-ethyl-substituted oxazole as in compound 14. Combinatorial and parallel synthesis provided a rapid analysis of the structure-activity relationship (SAR) for these inhibitors of CDK2, and over 100 analogues with IC(50) values in the 1-10 nM range were rapidly prepared. The X-ray crystallographic data of the inhibitors bound to the active site of CDK2 protein provided insight into the binding modes of these inhibitors, and the SAR of this series of analogues was rationalized. Many of these analogues displayed potent and broad spectrum antiproliferative activity across a panel of tumor cell lines in vitro. In addition, A2780 ovarian carcinoma cells undergo rapid apoptosis following exposure to CDK2 inhibitors of this class. Mechanism of action studies have confirmed that the phosphorylation of CDK2 substrates such as RB, histone H1, and DNA polymerase alpha (p70 subunit) is reduced in the presence of compound 14. Further optimization led to compounds such as water soluble 45, which possesses a favorable pharmacokinetic profile in mice and demonstrates significant antitumor activity in vivo in several murine and human models, including an engineered murine mammary tumor that overexpresses cyclin E, the coactivator of CDK2.