Predictive models for fentanyl dose requirement and postoperative pain using clinical and genetic factors in patients undergoing major breast surgery.

ABSTRACT: Fentanyl exhibits interindividual variability in its dose requirement due to various nongenetic and genetic factors such as single nucleotide polymorphisms (SNPs). This study aims to develop and cross-validate robust predictive models for postoperative fentanyl analgesic requirement and other related outcomes in patients undergoing major breast surgery. Data regarding genotypes of 10 candidate SNPs, cold pain test (CPT) scores, pupillary response to fentanyl (PRF), and other common clinical characteristics were recorded from 257 patients undergoing major breast surgery. Predictive models for 24-hour fentanyl requirement, 24-hour pain scores, and time for first analgesic (TFA) in the postoperative period were developed using 4 different algorithms: generalised linear regression model, linear support vector machine learning (SVM-Linear), random forest (RF), and Bayesian regularised neural network. The variant genotype of OPRM1 (rs1799971) and higher CPT scores were associated with higher 24-hour postoperative fentanyl consumption, whereas higher PRF and history of hypertension were associated with lower fentanyl requirement. The variant allele of COMT (rs4680) and higher CPT scores were associated with 24-hour postoperative pain scores. The variant genotype of CTSG (rs2070697), higher intraoperative fentanyl use, and higher CPT scores were associated with significantly lower TFA. The predictive models for 24-hour postoperative fentanyl requirement, pain scores, and TFA had R-squared values of 0.313 (SVM-Linear), 0.434 (SVM-Linear), and 0.532 (RF), respectively. We have developed and cross-validated predictive models for 24-hour postoperative fentanyl requirement, 24-hour postoperative pain scores, and TFA with satisfactory performance characteristics and incorporated them in a novel web application.

Impact of Genetic Variants on Postoperative Pain and Fentanyl Dose Requirement in Patients Undergoing Major Breast Surgery: A Candidate Gene Association Study.

BACKGROUND: Postoperative analgesia is crucial for the early and effective recovery of patients undergoing surgery. Although postoperative multimodal analgesia is widely practiced, opioids such as fentanyl are still one of the best analgesics. The analgesic response of fentanyl varies widely among individuals, probably due to genetic and nongenetic factors. Among genetic factors, single nucleotide polymorphisms (SNPs) may influence its analgesic response by altering the structure or function of genes involved in nociceptive, fentanyl pharmacodynamic, and pharmacokinetic pathways. Thus, it is necessary to comprehensively ascertain if the SNPs present in the aforementioned pathways are associated with interindividual differences in fentanyl requirement. In this study, we evaluated the association between 10 candidate SNPs in 9 genes and 24-hour postoperative fentanyl dose (primary outcome) and also with postoperative pain scores and time for first analgesia (secondary outcomes). METHODS: A total of 257 South Indian women, aged 18-70 years, with American Society of Anesthesiologists (ASA) physical status I-III, undergoing major breast surgery under general anesthesia, were included in the study. Patients were genotyped for candidate SNPs using real-time polymerase chain reaction. All patients received a standardized intravenous fentanyl infusion through a patient-controlled analgesic (PCA) pump, and the 24-hour postoperative fentanyl dose requirement was measured using PCA. RESULTS: The median 24-hour postoperative fentanyl requirement was higher in rs1799971 carriers (G/G versus A/A + A/G-620 µg [500-700] vs 460 µg [400-580]) with a geometric mean (GM) ratio of 1.91 (95% confidence interval [CI], 1.071-1.327). The median 24-hour pain scores were higher in rs4680 carriers (A/G + A/A versus G/G-34 [30-38] vs 31 [30-38]) with a GM ratio of 1.059 (95% CI, 1.018-1.101) and were lower in rs1045642 carriers (A/A + A/G versus G/G-34 [30-38] vs 30 [30-34]) with a GM ratio of 0.936 (95% CI, 0.889-0.987). The median time for first analgesic was lower in rs734784 carriers [C/C versus T/T + C/T-240 minutes (180-270) vs 240 minutes (210-270)] with a GM ratio of 0.902 (95% CI, 0.837-0.972). Five of 9 clinical factors, namely, history of diabetes, hypertension, hypothyroidism, anesthesia duration, and intraoperative fentanyl requirement were associated with different outcomes individually ( P < .05) and were used to adjust the respective associations. CONCLUSIONS: The SNP opioid receptor mu-1 ( OPRM1 ) (rs1799971) was associated with higher postoperative fentanyl requirement in South Indian patients undergoing major breast surgery. Twenty-four hour postoperative pain scores were higher in catechol-O-methyl transferase ( COMT ) (rs4680) carriers and lower in ATP binding cassette subfamily B member 1 ( ABCB1 ) (rs1045642) carriers, whereas time for first analgesic was lower in potassium channel subunit 1 ( KCNS1 ) (rs734784) carriers. However, these exploratory findings must be confirmed in a larger study.

Role of Drug Transporters in Elucidating Inter-Individual Variability in Pediatric Chemotherapy-Related Toxicities and Response.

Pediatric cancer treatment has evolved significantly in recent decades. The implementation of risk stratification strategies and the selection of evidence-based chemotherapy combinations have improved survival outcomes. However, there is large interindividual variability in terms of chemotherapy-related toxicities and, sometimes, the response among this population. This variability is partly attributed to the functional variability of drug-metabolizing enzymes (DME) and drug transporters (DTS) involved in the process of absorption, distribution, metabolism and excretion (ADME). The DTS, being ubiquitous, affects drug disposition across membranes and has relevance in determining chemotherapy response in pediatric cancer patients. Among the factors affecting DTS function, ontogeny or maturation is important in the pediatric population. In this narrative review, we describe the role of drug uptake/efflux transporters in defining pediatric chemotherapy-treatment-related toxicities and responses. Developmental differences in DTS and the consequent implications are also briefly discussed for the most commonly used chemotherapeutic drugs in the pediatric population.

Urologic, lymphedema, pelvic pain and gastrointestinal symptoms increase after radiotherapy in patients with primary uterine tumors: a prospective longitudinal Swedish cohort study

Purpose Radiotherapy (RT) causes an inflammatory reaction of the tissue which leads to fibrosis and reduced functioning of the pelvic organs. Few studies have shown significant relationships between side effects and RT in uterine tumors. Here, the urological, lymphedema, pelvic pain and gastrointestinal (GI) symptoms were studied before and after RT in patients with primary uterine tumors using the EORTC QLQ-EN24, specifically designed for uterine cancer patients. Methods This prospective cohort study comprised patients with primary uterine tumors who received pelvic radiotherapy (RT). A total of 43 patients were included from May 2014 to February 2019. Patients completed the questionnaires for global health status and functioning before the start of RT and at 3 and 12 months after RT. Results We found a significant worsening of the urological symptoms 3 months after RT which persisted up to 12 months after RT compared to baseline values prior to start of RT (p = 0.007). An exacerbation of the urinary symptoms was seen in patients with vaginal brachytherapy/boost compared to patients with pelvic RT at 12 months after RT (p = 0.053). The severity of lymphedema symptoms increased from RT start to 12 months after RT (p = 0.019) and the pelvic pain were higher at 3 months after RT compared to before RT (p = 0.004). Also, the level of GI symptoms was significantly higher 12 months after RT compared to the RT start (p < 0.001). Conclusions The urologic, lymphedema, pelvic pain and GI symptoms all increase after RT (AU)

Urologic, lymphedema, pelvic pain and gastrointestinal symptoms increase after radiotherapy in patients with primary uterine tumors: a prospective longitudinal Swedish cohort study.

PURPOSE: Radiotherapy (RT) causes an inflammatory reaction of the tissue which leads to fibrosis and reduced functioning of the pelvic organs. Few studies have shown significant relationships between side effects and RT in uterine tumors. Here, the urological, lymphedema, pelvic pain and gastrointestinal (GI) symptoms were studied before and after RT in patients with primary uterine tumors using the EORTC QLQ-EN24, specifically designed for uterine cancer patients. METHODS: This prospective cohort study comprised patients with primary uterine tumors who received pelvic radiotherapy (RT). A total of 43 patients were included from May 2014 to February 2019. Patients completed the questionnaires for global health status and functioning before the start of RT and at 3 and 12 months after RT. RESULTS: We found a significant worsening of the urological symptoms 3 months after RT which persisted up to 12 months after RT compared to baseline values prior to start of RT (p = 0.007). An exacerbation of the urinary symptoms was seen in patients with vaginal brachytherapy/boost compared to patients with pelvic RT at 12 months after RT (p = 0.053). The severity of lymphedema symptoms increased from RT start to 12 months after RT (p = 0.019) and the pelvic pain were higher at 3 months after RT compared to before RT (p = 0.004). Also, the level of GI symptoms was significantly higher 12 months after RT compared to the RT start (p < 0.001). CONCLUSIONS: The urologic, lymphedema, pelvic pain and GI symptoms all increase after RT.

Indo-Swiss symposium on advances in pharmacogenomic strategies for implementation of personalized medicine.

The Indo-Swiss symposium on advances in pharmacogenomic strategies for implementation of personalized medicine was conducted as a part of the JIPMER Integrated Pharmacogenomics Program (JIPP), held in Puducherry, India on 23 November 2019. The symposium focused on the growing contribution of pharmacogenomic information in designing treatment strategies and promoting better approaches to personalized medicine. The primary objective of this symposium was to bridge gaps in understanding the basics and recent advances in the field of pharmacogenomics. This symposium sought to promote interaction between the Indian and Swiss researchers to initiate future collaborative research projects. This symposium also served as a platform for young researchers to present their research findings as posters to the audience.

4-thiouridine induces dose-dependent reduction of oedema, leucocyte influx and tumour necrosis factor in lung inflammation.

Recent reports demonstrate a role for nucleotides as inflammatory modulators. Uridine, for example, reduces oedema formation and leucocyte infiltration in a Sephadex-induced lung inflammation model. Tumour necrosis factor (TNF) concentration was also reduced. Previous in vivo observations indicated that 4-thiouridine might have similar effects on leucocyte infiltration and TNF release. The aim of this study was thus to investigate the effects of 4-thiouridine in greater detail. We used a Sephadex-induced acute lung inflammation model in Sprague-Dawley rats. The dextran beads were instilled intratracheally into the lungs, which were excised and examined after 24 h. Sephadex alone led to massive oedema formation and infiltration of macrophages, neutrophils and eosinophils. Microgranulomas with giant cell formations were clearly visible around the partially degraded beads. A significant increase in bronchoalveolar lavage fluid (BALF) content of TNF and leukotrienes was also seen. 4-Thiouridine co-administration affected all variables investigated in this model, i.e. oedema, microscopic and macroscopic appearance of lung tissue, total leucocyte and differential leucocyte counts in BALF, TNF and leukotrienes C(4) (LTC(4)), LTD(4 )and LTE(4) in BALF, indicating a reproducible anti-inflammatory effect. In conclusion, we have demonstrated that 4-thiouridine has anti-inflammatory effects similar to those of uridine. To our knowledge, this is the first demonstration of pharmacological 4-thiouridine effects in vivo. The results suggest nucleoside/nucleotide involvement in inflammatory processes, warranting further studies on nucleoside analogues as attractive new alternatives in the treatment of inflammatory diseases.

Anti-inflammatory effects of exogenous uridine in an animal model of lung inflammation.

Nucleosides like adenosine, uridine and their nucleotide derivatives (e.g. ATP and UTP) play important roles in many cellular functions, sometimes by acting as signalling molecules through binding to specific P2 nucleotide receptors. P2 receptors are subdivided into P2X and P2Y subfamilies, the latter of which are G-protein coupled receptors. P2Y receptors and nucleoside transporters have been detected in human and rat lungs, where they mediate effects of interest in airway diseases. The aim of this study was to investigate whether uridine has any anti-inflammatory properties in an asthma-like animal model of lung inflammation. The Sephadex-induced lung inflammation model in Sprague-Dawley rats was chosen mainly due to its localised inflammatory response and uridine's limited oral bioavailability. The dextran beads, with or without the addition of uridine, were instilled intratracheally into the lungs, which were excised and examined after 24 h. Sephadex alone led to massive oedema and infiltration of macrophages, neutrophils and eosinophils. Microgranulomas with giant cell formations were clearly visible around the partially degraded beads. Uridine reduced both the oedema and the infiltration of leukocytes significantly, measured as lung wet weight and leukocyte counts in bronchoalveolar lavage fluid, respectively. Uridine appeared to affect the tumour necrosis factor (TNF) levels, although this could not be statistically confirmed due to large variations within the Sephadex control group. We conclude that uridine has anti-inflammatory effects, and that the exact mechanism(s) of action requires further study.

Corticosteroids and interferons inhibit cytokine-induced production of IL-8 by human endothelial cells.

IL-8, secreted by endothelial cells at the site of inflammation, participates in recruitment and transmigration of leukocytes. IL-8 may also have pathophysiological consequences in inflammatory and immunological disorders. We have investigated the effect of interferons (IFNs) and glucocorticosteroids (GCs) on cytokine induced secretion and production of IL-8 by human umbilical endothelial cells (HUVEC). There was a low spontaneous secretion of IL-8 by unstimulated HUVEC which increased after 6 or 24 h of stimulation with the pro-inflammatory cytokines TNF-alpha or IL-1beta. IFN-gamma as well as the GCs, Dexamethasone and Budesonide, inhibited TNF-alpha induced IL-8 secretion in a dose-dependent manner. IFNs may have a general modulating effect, since IFN-alpha also inhibited the TNF-alpha-induced IL-8 secretion. There was a slight, but significant, increase in the content of intracellular IL-8 in stimulated HUVEC. However, there was no difference between stimulation with IL-1beta or TNF-alpha alone or in combination with IFNs or GCs, whereas inhibition of IL-8 secretion with monensin increased IL-8 content suggesting that IFNs and GCs inhibit synthesis rather than secretion of IL-8. In conclusion, IFNs or GCs may be useful for inhibiting IL-8 production by endothelial cells and could thus be used for therapeutic modulation of the inflammatory response.

p185 HER2/neu epitope mapping with murine monoclonal antibodies.

In order to obtain further information on the biological role of the HER2/neu oncoprotein, 7 new monoclonal antibodies (MAbs) were produced against the p185HER2 extracellular domain. These MAbs, together with two others previously produced, were used to investigate the p185HER2 expression in breast carcinomas and compare the recognized antigenic determinants. The 7 reagents (MGR4,5,6,7,8,9 and 10), were shown to define five distinct epitopes. Three of these MAbs (MGR5,7,10), as well as one previously produced (MGR2), recognize the same epitope (Epitope-1) which seems, therefore, to be highly immunogenic for the murine immune system. Epitope-2 recognized by the MGR4 MAb, appears to be closely related to epitope-1 due to a cross inhibition between MGR4 and MGR10, but not MGR2. Epitope-2 is the only one of the 5 also present on the product of the neu oncogene, the rat analogue of the human HER2/neu gene. None of the reagents against epitope-1 and epitope-2 were found to mediate receptor internalization, whereas MGR6 as well as a previously produced MAb (MGR3), both of which define epitope-3 and MGR8 which defines epitope-4, were found to do so. Epitope-4 like the neu-specific peptide recognized by the reference c-neu Ab3 MAb, was detectable on all p185HER2 positive breast cancer, independently from the quantitative content of the oncoprotein, at variance with the other 4 epitopes whose availability on p185HER2 for the relevant MAbs varied with the degree of overexpression. Epitope-5, recognized by the MGR9 MAb, on the contrary to the other epitopes, was prevalently localized at the basal membrane level of the tumor nodule.

Affinity purification of monoclonal antibodies, using a bifunctional oligosaccharide hapten.

A bifunctional hapten was synthesized consisting of a blood group A active tetrasaccharide (A-tetra) and a blood group Le(a) active pentasaccharide lacto-N-fucopentaose II (LNF II), linked to each other with a phenylaminothiourea spacer connecting the reducing ends (A-tetra-LNF II). The hapten was demonstrated to retain both blood group A and Le(a) activity and could be easily bound to both monoclonal anti-A and anti-Le(a) affinity columns. Due to the strong temperature dependence of the two antibodies their binding to oligosaccharides, the bifunctional hapten could be utilized to achieve easy desorption in the final step of affinity purification of either monoclonal anti-Le(a) or anti-A. The system is postulated to have general applicability in affinity purification of any ligate that binds with an avidity too high to achieve non-denaturing desorption.