Pteridine reductase (PTR1): initial structure-activity relationships studies of potential leishmanicidal arylindole derivatives compounds

Leishmaniasis is a public health concern, especially in Brazil and India. The drugs available for therapy are old, cause toxicity and have reports of resistance. Therefore, this paper aimed to carry out initial structure-activity relationships (applying molecular docking and dynamic simulations) of arylindole scaffolds against the pteridine reductase (PTR1), which is essential target for the survival of the parasite. Thus, we used a series of 43 arylindole derivatives as a privileged skeleton, which have been evaluated previously for different biological actions. Compound 7 stood out among its analogues presenting the best results of average number of interactions with binding site (2.00) and catalytic triad (1.00). Additionally, the same compound presented the best binding free energy (-32.33 kcal/mol) in dynamic simulations. Furthermore, with computational studies, it was possible to comprehend and discuss the influences of the substituent sizes, positions of substitutions in the aromatic ring and electronic influences. Therefore, this study can be a starting point for the structural improvements needed to obtain a good leishmanicidal drug.

Identifications of good and bad structural fragments of hydrazone/2,5-disubstituted-1,3,4-oxadiazole hybrids with correlation intensity index and consensus modelling using Monte Carlo based QSAR studies, their molecular docking and ADME analysis

The application of QSAR along with other in silico tools like molecular docking, and molecular dynamics provide a lot of promise for finding new treatments for life-threatening diseases like Type 2 diabetes mellitus (T2DM). The present study is an attempt to develop Monte Carlo algorithm-based QSAR models using freely available CORAL software. The experimental data on the α-amylase inhibition by a series of benzothiazole-linked hydrazone/2,5-disubstituted-1,3,4-oxadiazole hybrids were selected as endpoint for the model generation. Initially, a total of eight QSAR models were built using correlation intensity index (CII) as a criterion of predictive potential. The model developed from split 6 using CII was the most reliable because of the highest numerical value of the determination coefficient of the validation set (r²_VAL = 0.8739). The important structural fragments responsible for altering the endpoint were also extracted from the best-built model. With the goal of improved prediction quality and lower prediction errors, the validated models were used to build consensus models. Molecular docking was used to know the binding mode and pose of the selected derivatives. Further, to get insight into their metabolism by living beings, ADME studies were investigated using internet freeware, SwissADME.

COVID-19 infection in patients with intestinal failure: UK experience

BACKGROUND

The direct effect of the coronavirus disease 2019 (COVID-19) pandemic on patients with intestinal failure (IF) has not been described.

METHODS

We conducted a nationwide study of UK IF centers to evaluate the infection rates, presentations, and outcomes in patients with types 2 and 3 IF.

RESULTS

A total of 45 patients with IF contracted COVID-19 between March and August 2020; this included 26 of 2191 (1.2%) home parenteral nutrition (HPN)-dependent adults and 19 of 298 (6.4%) adults hospitalized with type 2 IF. The proportion of patients receiving nursing care for HPN administration was higher in those with community-acquired COVID-19 (66.7%) than the proportion in the entire HPN cohort (26.1%; P < .01). Two HPN-dependent and 1 hospitalized patient with type 2 IF died as a direct consequence of the virus (6.7% of 45 patients with types 2 or 3 infected).

CONCLUSION

This is the first study to describe the outcomes of COVID-19 in a large cohort of patients requiring long-term PN. Methods to reduce hospital and community nosocomial spread would likely be beneficial.

Dealing with loss: food and eating in women with ovarian cancer on parenteral nutrition

BACKGROUND

Malignant bowel obstruction is a common complication of ovarian cancer, resulting in limited oral intake. Home parenteral nutrition (HPN) may be offered to patients in this condition to meet nutritional requirements. However, it is not known how they experience being unable to eat. The present study reports how patients related to food when receiving HPN.

METHODS

The investigation was a qualitative study underpinned by phenomenology with women with advanced ovarian cancer in bowel obstruction receiving parenteral nutrition. Interview transcripts were analysed thematically guided by the techniques of Van Manen.

RESULTS

We recruited 20 women to the study. Participants were interviewed a maximum of four times and a total of 39 in-depth longitudinal interviews were conducted. Participants could tolerate minimal amounts of food, if they had a venting gastrostomy. Not being able to eat engendered a sense of sadness and loss, and most women found it challenging to be in the presence of others eating. They adopted strategies to cope, which included fantasising about food and watching cookery programmes. These approaches were not a long-term solution; either participants came to terms with their loss or the strategies became less effective in providing relief.

CONCLUSIONS

Home parenteral nutrition meets the nutritional requirements of patients with malignant bowel obstruction but cannot replace the non-nutritive functions of food. Healthcare professionals can offer a patient-centred approach by acknowledging the difficulties that patients may face and, wherever possible, encourage them to focus on the positive benefits of interacting with people rather than the loss of eating on social occasions.

Metabolic bone diseases in intestinal failure

Metabolic bone diseases are a group of conditions that are common complications in patients with intestinal failure. These may occur as a result of the underlying condition, leading to intestinal failure, particularly inflammatory conditions such as Crohn's disease and their associated treatments including corticosteroids. Malabsorption, as a result of a loss of enterocyte mass or gut function, of many nutrients, including vitamin D, may further compound metabolic bone problems, and there has been historical contamination of parenteral nutrition with aluminium that has prevented normal bone metabolism contributing to osteoporosis. This review looks at the diagnosis and current management of bone health in patients with intestinal failure.

A novel discharge pathway for patients with advanced cancer requiring home parenteral nutrition

BACKGROUND

The use of home parenteral nutrition (HPN) for palliative indications is increasing internationally and is the leading indication in some countries. Discharge on HPN can be complex in metabolically unstable patients and requires intestinal failure expertise.

METHODS

Between 2012 and 2018, we performed a retrospective analysis aiming to assess the impact of a novel remote discharge pathway for palliative HPN patients. This was evaluated using a quality improvement approach.

RESULTS

One hundred and twenty-five patients with active malignancy [mean (range) age 58 (25-80) years] were referred to the intestinal failure unit (IFU) for remote discharge. Of 82 patients were discharged from the oncology Centre on HPN using the pathway. The remaining 43 patients either declined HPN or the Oncology team felt that the patient became too unwell for HPN or died prior to discharge. There was an increase in patients referred for remote discharge from 13 in 2012 to 43 in 2017. The mean number of days between receipt of referral by the IFU to discharge on HPN from the oncology centre reduced from 29.4 days to 10.1 days. Following remote discharge, the mean number of days on HPN was 215.9 days. Catheter-related blood stream infection rates in this cohort were very low at 0.169 per 1000 catheter days.

CONCLUSIONS

This is the first study to demonstrate the remote safe, effective and rapid discharge of patients requiring palliative HPN between two hospital sites. This allows patients with a short prognosis more time in their desired location.

Abstract PD5-08: Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers

Understanding how standard-of-care drug treatments affect tumor intrinsic biology and microenvironment is critical for elucidating drug resistance mechanisms and developing better combination therapies as well as new therapies. To characterize the effects of neoadjuvant chemotherapy (NAC) on the genome, transcriptome and tumor infiltrating leukocytes (TILs), we have conducted whole exome and whole transcriptome sequencing of a large longitudinal breast cancer cohort consisting of 146 cases and 281 paired tumor samples. In total, 52 (38%) patients achieved pathologic complete response (pCR) while 85 patients (62%) had residual disease with standard chemotherapy regimen. Tumor biopsies were collected for each patient at three time points – pre-treatment, three weeks after the first cycle of anthracycline and cyclophosphamide (AC) and at the time of surgery after 3 more cycles of AC followed by 4 cycles of taxane or taxane plus Herceptin in case of HER2+ subtype. We detected 5,955 protein-altering somatic mutations affecting 4,414 genes in pretreatment samples and 502 acquired mutations in surgery samples affecting 477 genes including 19recurrently mutated genes such as TP53 and NOTCH1. Across all subtypes, 4,346 genes were differentially expressed (DE) following NAC treatment and significantly enriched in pathways such as cell cycle, ER signaling, PI3K/mTOR, immune and metabolism. Expression-based virtual microdissection analysis indicated that NAC treatment induced an increase in the fractions of stromal and adjacent normal tissue compartment, consistent with observed reduction in tumor cellularity. To assess the NAC induced changes in the molecular landscape of these tumors, we compared molecular features including gene expression signatures, mutation prevalence and copy number alteration between three time points while adjusting for confounding effects of molecular subtype and tumor cellularity. We found that NAC induced dynamic changes in gene expression signatures associated with proliferation and immunomodulatory treatment response. We further validated the observed pattern of change in TILs through histopathology and digital imaging analyses. In pretreatment tumors, 116 genes were DE between patients with pCR vs. those with residual disease with significant enrichment in immune/inflammatory pathways. Further, pre-treatment TIL levels were found to be significantly associated with pCR, echoing previous reports in breast cancers that implicated anti-tumor immunity in mediating the efficacy of chemotherapies. Our analyses also revealed associations between NAC response and baseline genomic attributes such as genomic alterations that affect DNA damage repair pathways. Taken together, these results suggest that NAC induced a multitude of changes on the genomic landscape and immune microenvironment of breast cancers, some of which point to combination strategies with immunomodulatory therapies and therapies that target DNA damage repair.

Citation Format: Kan Z, Lal S, Ding Y, Lee JE, Lee S-H, Lee SK, Yu JH, Choi Y-l, Kim SW, Nam SJ, Kim J-Y, Ram S, Powell E, Ching K, Cho SY, Bonato V, Deng S, Park W-Y, Rejto P, Bienkowska J, Park Y-H. Neoadjuvant chemotherapy alters the genomic landscape and immune microenvironment of breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD5-08.