A covalent fragment-based strategy targeting a novel cysteine to inhibit activity of mutant EGFR kinase

Several generations of ATP-competitive anti-cancer drugs that inhibit the activity of the intracellular kinase domain of the epidermal growth factor receptor (EGFR) have been developed over the past twenty years. The first-generation of drugs such as gefitinib bind reversibly and were followed by a second-generation such as dacomitinib that harbor an acrylamide moiety that forms a covalent bond with C797 in the ATP binding pocket. Resistance emerges through mutation of the T790 gatekeeper residue to methionine, which introduces steric hindrance to drug binding and increases the Km for ATP. A third generation of drugs, such as osimertinib were developed which were effective against T790M EGFR in which an acrylamide moiety forms a covalent bond with C797, although resistance has emerged by mutation to S797. A fragment-based screen to identify new starting points for an EGFR inhibitor serendipitously identified a fragment that reacted with C775, a previously unexploited residue in the ATP binding pocket for a covalent inhibitor to target. A number of acrylamide containing fragments were identified that selectively reacted with C775. One of these acrylamides was optimized to a highly selective inhibitor with sub-1 μM activity, that is active against T790M, C797S mutant EGFR independent of ATP concentration, providing a potential new strategy for pan-EGFR mutant inhibition.

A novel Menin-MLL1 inhibitor, DS-1594a, prevents the progression of acute leukemia with rearranged MLL1 or mutated NPM1

BACKGROUND

Mixed lineage leukemia 1-rearranged (MLL1-r) acute leukemia patients respond poorly to currently available treatments and there is a need to develop more effective therapies directly disrupting the Menin‒MLL1 complex. Small-molecule-mediated inhibition of the protein‒protein interaction between Menin and MLL1 fusion proteins is a potential therapeutic strategy for patients with MLL1-r or mutated-nucleophosmin 1 (NPM1c) acute leukemia. In this study, we preclinically evaluated the new compound DS-1594a and its salts.

METHODS

We evaluated the preclinical efficacy of DS-1594a as well as DS-1594a·HCl (the HCl salt of DS-1594a) and DS-1594a·succinate (the succinic acid salt of DS-1594a, DS-1594b) in vitro and in vivo using acute myeloid leukemia (AML)/acute lymphoblastic leukemia (ALL) models.

RESULTS

Our results showed that MLL1-r or NPM1c human leukemic cell lines were selectively and highly sensitive to DS-1594a·HCl, with 50% growth inhibition values < 30 nM. Compared with cytrabine, the standard chemotherapy drug as AML therapy, both DS-1594a·HCl and DS-1594a·succinate mediated the eradication of potential leukemia-initiating cells by enhancing differentiation and reducing serial colony-forming potential in MLL1-r AML cells in vitro. The results were confirmed by flow cytometry, RNA sequencing, RT‒qPCR and chromatin immunoprecipitation sequencing analyses. DS-1594a·HCl and DS-1594a·succinate exhibited significant antitumor efficacy and survival benefit in MOLM-13 cell and patient-derived xenograft models of MLL1-r or NPM1c acute leukemia in vivo.

CONCLUSION

We have generated a novel, potent, orally available small-molecule inhibitor of the Menin-MLL1 interaction, DS-1594a. Our results suggest that DS-1594a has medicinal properties distinct from those of cytarabine and that DS-1594a has the potential to be a new anticancer therapy and support oral dosing regimen for clinical studies (NCT04752163).

Synthesis of protected precursors of chitin oligosaccharides by electrochemical polyglycosylation of thioglycosides

The synthesis of protected precursors of chitin oligosaccharides by electrochemical polyglycosylation of thioglycosides as monomer is described. Oligosaccharides up to the hexasaccharide were synthesized under optimized reaction conditions. Further, a modified method enabled the synthesis of oligosaccharides up to the octasaccharide by repeating electrolysis with additional monomers. The mechanism of the electrochemical polyglycosylation is also discussed, based on the oxidation potential of the monomer and oligosaccharides.

Synthesis of cyclic α-1,4-oligo-N-acetylglucosamine 'cyclokasaodorin' via a one-pot electrochemical polyglycosylation-isomerization-cyclization process

Electrochemical synthesis of unnatural cyclic oligosaccharides composed of N-acetylglucosamine with α-1,4-glycosidic linkages has been accomplished. A thioglycoside monomer equipped with the 2,3-oxazolidinone protecting group was used to prepare linear oligosaccharides by electrochemical polyglycosylation. In the same pot, isomerization of the linear oligosaccharides and intramolecular electrochemical glycosylation for cyclization were also conducted sequentially to obtain the precursor of the cyclic α-1,4-oligo-N-acetylglucosamine 'cyclokasaodorin'.

Abstract 1132: Development and characterization of a novel orally bioavailable menin-MLL inhibitor for treatment of acute leukemia patients with MLL-rearrangement or NPM1 mutation

DS-M1 is a novel, potent, orally bioavailable small molecule inhibitor of the binding of MLL1 fusion proteins and wild-type MLL1 to Menin in development for the treatment of patients with MLL1-rearranged (MLL1-r) or NPM1-mutated (NPM1-mu) acute leukemia. The interaction of MLL1 fusion proteins with menin plays an important role to enhance the proliferation and block the differentiation of hematopoietic cells, ultimately leading to acute leukemia. Furthermore, patients with MLL1-r acute leukemia respond poorly to currently available treatments, emphasizing the urgent need to develop more effective therapies directly disrupting the menin-MLL1 complex. Here we describe the characterization of DS-M1 and this study demonstrates the mechanism of action of DS-M1 as well as supports the oral dosing regimen planned for the initial clinical studies. DS-M1 selectively inhibited the cellular growth of MLL1-r or NPM1-mu human leukemic cell lines and primary cells from patients with GI50 of less than about 100 nM along with the cellular differentiation in vitro. RNA-seq and ChIP-seq analysis revealed that DS-M1 reduced the expression levels of MEIS1, PBX3 and HOXA9 genes in a concentration-dependent manner and dissociated the menin-MLL1 complex from the MEIS1 gene locus in MV-4-11, MOLM-13, and patient derived AML cells with MLL1-rearrangement. Interestingly, DS-M1 reduced the number of CD34+/CD38- leukemic stem cells (LSCs) in patient derived AML cells and induction of differentiation was also confirmed as measured by increased CD11b or CD14 expression. These results suggest that enhanced differentiation and loss of LSCs via the reduction of MEIS1, HOXA9, and PBX3 gene expression by DS-M1 is one of the main mechanisms of action for the antitumor activity of DS-M1. DS-M1 demonstrates significant survival benefit along with inhibition of MEIS1, HOXA9 and PBX3 expression in aggressive disseminated leukemia models intravenously inoculated with MV-4-11 and MOLM-13 cells as well as in patient-derived xenograft (PDX) models of MLL1-r or NPM1-mu acute leukemia. In disseminated MOLM-13 xenografts, treatment with 100 mg/kg qd of DS-M1 for 19 days produced durable response with event free survival &gt;100 days after last dose (5 out of 6 mice, increase in life span (ILS) &gt;515%). Furthermore, MLL1-r pediatric B-ALL-PDX mice treated with 50 mg/kg bid for 28 days and NPM1-mu AML-PDX mice treated with 100 mg/kg bid for 35 days were all survived (ILS &gt;254% and &gt;300%) without any detectable leukemic blast cells in bone marrow at 120 and 60 days after cessation of therapy, respectively. These data indicate that DS-M1 has a high potency as an antitumor drug with the potential to provide survival advantage in acute leukemia patients with MLL-r and NPM1-mu. Currently, a Phase 1/2 clinical study of DS-M1 is planned in AML and ALL patients with MLL-r or NPM1-mu.

Citation Format: Masashi Numata, Machiko Shiroishi, Kenji Yoshikawa, Noriyasu Haginoya, Tsuyoshi Hirata, Yoshimi Takata, Reina Nagase, Kohei Takashima, Akiko Kurimoto, Fumie Tanzawa, Yumiko Tomoe, Tomoaki Hamada, Ryutaro Kanada, Jun Watanabe, Yoshiko Kagoshima, Eri Tokumaru, Kenji Murata, Takayuki Baba, Taeko Shinozaki, Kazuyuki Hashimoto, Motohiro Kato, Shinji Tsutsumi, Mayumi Kitagawa, Kosaku Fujiwara, Yuki Abe. Development and characterization of a novel orally bioavailable menin-MLL inhibitor for treatment of acute leukemia patients with MLL-rearrangement or NPM1 mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1132.

P3536Prevalence and clinical impact of social frailty in elderly patients hospitalized for acute decompensated heart failure: a multicenter prospective cohort study

Purpose

The aim of this study was to investigate clinical characteristics of socially frail patients and an association with social frailty and short-term rehospitalization for worsening heart failure.

Methods

We analyzed 169 elderly patients (≥65 years old) hospitalized for acute decompensated heart failure (ADHF) between June 2017 and August 2018 in our prospective HF registry in Japan. The patients with activities of daily living dependence and without data of social frailty and outcome were excluded. Social frailty was determined based on their responses to the 5 questions (living alone, eating alone, going out less frequently, rarely visiting friends, not helpful to friends or family). Patients with none of these components were considered social non-frailty; those with one component were considered social prefrailty; those with two or more components were considered social frailty. The outcome was rehospitalization for worsening HF within 6 months after discharge.

Results

The mean age was 79±8 years old. Social frailty in 86 patients (50.8%), social prefrailty in 41 patients (24.3%), and social non-frailty in 42 patients (24.9%) were observed. Age, body mass index, geriatrics nutritional risk index, Hasegawa dementia rating scale-revised score, gait speed, and handgrip strength values were significantly different among the these three groups (all Ps for trend <0.01). Left ventricular ejection fraction, brain natriuretic peptide values, and the proportion of the patients with the symptom of New York Heart Association class III/IV did not vary significantly between the groups. Kaplan-Meier analysis revealed that higher prevalence of rehospitalization for worsening HF within 6 months in the social frailty group compared to that in the social non-frailty group (Log-rank p<0.05). In a Cox proportional hazard model after adjusting covariates, patients with social frailty (hazard ratio 4.77; 95% CI 1.61–14.12, p<0.005) and social prefrailty (hazard ratio 3.73; 95% CI 1.12–12.41, p<0.05) had an increased risk of rehospitalization for worsening HF within 6 months compared with those with social non-frailty.

Conclusion

This study revealed that social frailty was common in elderly patients hospitalized for ADHF, and social frailty was an independent predictor of rehospitalization for worsening HF within 6 months after discharge.

Subjective Evaluation of Denture Adhesives: A Multicenter Randomized Controlled Trial

INTRODUCTION

Many reports show that denture adhesives improve the retention and stability of dentures. However, few randomized controlled trials have examined the effects of denture adhesives.

OBJECTIVE

This 10-center randomized controlled trial with parallel groups involving 200 edentulous patients wearing complete dentures aimed to evaluate the effects of short-term use of cream and powder denture adhesives.

METHODS

Patients were allocated into 2 cream- and powder-type adhesive groups and 1 control group. Intervention groups were treated with the 2 adhesives (1 each), and the control group received saline solution. Adhesive or control was applied to the denture-mucosal surface for 4 d, and data at baseline and after day 4 of intervention (i.e., 8 meals) were obtained. Patient satisfaction was evaluated with a 100-mm visual analog scale. Oral health-related quality of life was measured with the Japanese version of the Oral Health Impact Profile for Edentulous Patients. Perceived chewing ability was evaluated by a questionnaire regarding ease of chewing and swallowing food. Between-group comparisons were performed with Kruskal-Wallis tests with the Mann-Whitney U test adjusted by Bonferroni correction. Within-group comparisons of pre- and postintervention measurements were performed with the Wilcoxon signed-rank test. Intention-to-treat analysis was also performed.

RESULTS

Between-group comparisons showed no significant differences for general satisfaction or Oral Health Impact Profile for Edentulous Patients. However, significant differences in satisfaction with various denture functions with cream- and powder-type adhesives were seen in pre- and postintervention comparisons (P < 0.05). Significant differences were also observed for perceived chewing ability of hard foods (P < 0.05).

CONCLUSION

These results suggest that although denture adhesives do not invariably improve denture function, they do affect subjective evaluations and possibly chewing of hard foods. Therefore, the effects of denture adhesive use are insufficient to resolve any fundamental dissatisfaction with dentures ( ClinicalTrials.gov NCT01712802 ).

KNOWLEDGE TRANSFER STATEMENT

The results of this study suggest that denture adhesives should be applied under certain conditions; however, an appropriate diagnosis is important before application. These practice-based data provide information to establish evidence-based guidelines for applying denture adhesives.

Enhancement of Osteogenesis by Concanavalin a in Human Bone Marrow Mesenchymal Stem Cell Cultures

This study investigates concanavalin A (ConA) as a novel factor that may enhance osteogenesis of mesenchymal stem cells (MSCs) in vitro. Various factors, such as cytokine bone morphogenetic protein-2 (BMP-2), have been studied for their possible promotion of MSC osteogenesis in vivo and in vitro. However, the factor that might be safer, more effective, and less expensive than these has not been determined. We therefore cultured human MSCs in osteogenic medium in the presence or absence of ConA, and used calcium assays to compare the effects of ConA and BMP-2 on MSC calcification. We also used enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (PCR) to evaluate the expression levels of bone-specific markers. ConA and BMP-2 enhanced calcification with comparable effectiveness. The combination of ConA and BMP-2 further enhanced calcification slightly but significantly. ConA also increased osteocalcin and BMP-2 protein levels in MSC culture medium. Furthermore, ConA increased osteocalcin, RUNX2, BMP-2, BMP-4, and BMP-6 mRNA expression levels. However, the gene expression pattern of ConA-stimulated MSCs was different from that of MSCs stimulated by BMP-2. Together, these results suggest that ConA and BMP-2 enhance MSC osteogenesis via different pathways. ConA-induced bone formation in MSC cultures may be useful in regenerative medicine or tissue engineering in clinical studies, as well as in basic research on bone formation.

An unusual clinical presentation of lupus erythematosus tumidus localized on the thigh

A 44-year-old woman with seronegative polyarthritis presented with a 2-year history of a solitary, bluish-red, oedematous, nonscaly, annular and partially reticulated macule on her right thigh. Histopathological findings revealed perivascular and periadnexal lymphocytic infiltrate in the dermis. Alcian blue and colloidal iron stains highlighted mucinous deposit in the upper and mid dermis. Direct immunofluorescence showed a linear deposit of IgG and C3 along the basement membrane zone. Antinuclear antibody was positive at a titre of 1 : 80, with homogenous and speckled patterns. Except for its unusual localization and lack of photosensitivity, our case had the clinical and histopathological features of lupus erythematosus tumidus. These characteristics were also reminiscent of reticular erythematous mucinosis and erythema annulare centrifugum, both of which are considered to be associated with cutaneous lupus erythematosus (CLE). Hydroxychloroquine 200 mg daily led to improvement of the skin lesion. The unusual clinical presentation of our case emphasizes the heterogeneity of clinical manifestations of CLE.

The Biomarker Salivary SP-D May Indicate Small Airway Inflammation and Asthma Exacerbation

BACKGROUND

Noninvasive and child-friendly biomarkers are important tools for understanding the various phenotypes of childhood asthma. Objective: The aim of this study was to examine the usefulness of salivary surfactant protein (SP) D in assessing the pathophysiology of childhood asthma.

METHODS

We measured salivary concentrations of SP-D and forced oscillation technique (FOT) indexes in 19 healthy controls and 21 asthmatic children. Regression equations for the predictive values of FOT indexes were generated from healthy controls. We analyzed the correlations between salivary SP-D concentration and percentages of the predictive values of FOT indexes, as well as the severity of exacerbation.

RESULTS

We found that salivary SP-D levels were higher in asthmatic children than in healthy controls. In the asthmatic children, salivary SP-D levels correlated with the percentages of predicted differences in resistance between 5 Hz and 20 Hz (%R5-R20), which represented the resistance of peripheral airways, and with the severity of asthma exacerbation.

CONCLUSIONS

Salivary SP-D may reflect asthmatic inflammation in peripheral small airways and may be a useful marker for monitoring the degree of exacerbation in childhood asthma.

Dynamic Viscoelasticity of Soft Liners and Masticatory Function

Soft denture liners are used for edentulous patients to cushion functional forces. We hypothesized that the application of soft liners having viscoelastic properties would lead to the most marked improvement in masticatory function. The shear storage modulus ( G′), shear loss modulus ( G′′), and loss tangent (tan δ) were determined for 6 materials by means of a dynamic viscoelastometer. Masticatory function of ten subjects was evaluated by measurements of maximum bite forces and chewing times and frequencies for 2 food samples, and by the use of visual analogue scales. The acrylic materials exhibited viscoelastic behavior, while the silicones exhibited elastic behavior. The improvement in masticatory function compared with hard resin was found to be in the order: acrylic permanent materials > silicone > acrylic temporary materials. The results suggest that the use of materials with higher tan δ and G′ provides the most optimum masticatory function for patients requiring the provision of soft liners on their dentures.

Viscoelasticity of Dental Tissue Conditioners during the Sol-gel Transition

Formation of tissue conditioners is a process of polymer chain entanglements. This study evaluated the influence of composition and structure on dynamic viscoelasticity of concentrated polymer solutions based on poly(ethyl methacrylate) (PEMA) used as tissue conditioners through the sol-gel transition. The hypothesis was that the ethanol content is the most influential factor in determining gelation speed. Rheological parameters were determined with the use of a controlled-stress rheometer. Analysis of variance by orthogonal array L16(45) indicated that the strong polar bonding of ethanol (contribution ratio ρ = 53.8%; confirming the hypothesis) and molecular weight of polymer powders (ρ = 26.7%) had a greater influence on the gelation times of PEMA-based systems than did the molar volume of plasticizers (ρ = 9.0%) and concentration of polymers ( i.e., powder/liquid ratio) (ρ = 4.5%). The results suggest that the gelation of tissue conditioners based on PEMA can be controlled over a wide range by varying the polymer molecular weight, and especially ethanol content.

Effect of Antihypertensive Drugs on Uric Acid Metabolism in Patients with Hypertension: Cross-Sectional Cohort Study

Background: Hypertension is a common complication in patients with gout and/or hyperuricemia. Besides, hyperuricemia is a risk factor of gout as well as ischemic heart disease in hypertensive patients. Moreover, the risk of gout is modified by antihypertensive drugs. However, it remains unclear how antihypertensive agents affect uric acid metabolism. Purpose: In the present study, we investigated the uric acid metabolism in treated hypertensive patients to find out whether any of them would influence serum levels of uric acid. Patients and methods: 751 hypertensive patients (313 men and 438 women) under antihypertensive treatment were selected. Blood pressure (BP), serum uric acid (SUA) and serum creatinine (Scr) were measured and evaluated statistically. Results: In patients treated with diuretics, beta-blockers and/or alpha-1 blockers SUA levels were significantly higher than in patients who were not taking these drugs. Besides, the estimated glomerular filtration rate (eGFR) in patients treated with diuretics, beta-blockers and/or alpha-1 blockers was negatively correlated with SUA level. There were gender differences in the effects of beta-blockers and alpha-1 blockers. Multiple regression analysis indicated that both diuretics and beta-blockers significantly contributed to hyperuricemia in patients with medication for hypertension. Conclusion: Diuretics, beta-blockers and alpha-1 blockers reduced glomerular filtration rate and raised SUA levels. Calcium channel blockers, ACE inhibitors and angiotensin receptor blockers, including losartan, did not increase SUA levels.

MR Imaging of the Liver before and after Transcatheter Hepatic Chemo-Embolization for Hepatocellular Carcinoma

Transcatheter chemo-embolization (TCE) in hepatocellular carcinoma (HCC) was performed in 38 patients. The patients were examined by MR imaging before TCE as well as one week and 4 to 5 weeks after TCE. The tumor signal intensity in T2 weighted images increased in 13 cases and decreased in 19 cases after TCE. Increased intensity seemed to reflect intra-tumoral hemorrhage or liquefaction accompanying tumor necrosis. Decreased intensity seemed to reflect coagulation necrosis. In 9 of 18 cases followed over a 2-month period the signal intensity had decreased in both T1 and T2 weighted images. In these patients the tumor showed no recurrence at angiography and the decreased signal seemed to reflect the completion of coagulation necrosis. A hyper- and/or hypointense rim around the tumor appeared in 22 cases. These changes were thought to be perifocal edema or granulation tissue around the tumor. MR imaging was useful in evaluating the necrotic process of the tumor after TCE.

HLA-DPB1*0501 is not uniquely associated with opticospinal multiple sclerosis in Japanese patients. Important role of DPB1*0301

Apart from its unique lesion distribution pattern, the opticospinal form of multiple sclerosis (OSMS) is distinct among Japanese patients who satisfy the diagnostic criteria of MS. OSMS has been suggested to be strongly associated with HLA-DPB1*0501 in Japanese. However, association of DPB1*0301 with non-OSMS and lack of DPB1*0301 in OSMS were also reported. To verify the role of DPB1*0501 and DPB1*0301 in Japanese MS patients we determined the frequencies of these alleles in 26 patients with OSMS, 167 with non-OSMS and 156 normal subjects, who were all residents of Hokkaido, the northernmost island of Japan. All (100%) OSMS were negative for DPB1*0301 while 32 (19%) of the non-OSMS were positive for the allele. In DPB1*0301-negatives, the frequencies of DPB1*0501 in OSMS (85%) and non-OSMS (82%) were similar, but both were higher than in the controls (66%). In DPB1*0301-positives, the frequency of DPB1*0501 was low but similar in non-OSMS (12/32; 38%) and controls (6/14; 43%). Periventricular white matter lesions (PVL) were noted in 31 of 32 (97%) DPB1*0301-positive non-OSMS patients but in only 22 out of 135 (16%) DPB1*0301-negative non-OSMS patients and two out of 26 (8%) OSMS patients. Our findings indicate that DPB1*0501 plays an important role in the development of MS in general, but not in OSMS. The strong association of DPB1*0501 with OSMS may be due to the over-representation of the DPB1*0301 allele among individuals in the non-OSMS group. In addition, DPB1*0301 might be relevant to the development of periventricular lesions in Japanese patients with MS.

Levobupivacaine-dextran mixture for transversus abdominis plane block and rectus sheath block in patients undergoing laparoscopic colectomy: a randomised controlled trial

We performed a randomised controlled double-blinded study of patients having laparoscopic colectomy with bilateral transversus abdominis plane block plus rectus sheath block, comparing a control group receiving 80 ml levobupivacaine 0.2% in saline with a dextran group receiving 80 ml levobupivacaine 0.2% in 8% low-molecular weight dextran. Twenty-seven patients were studied in each group. The mean (SD) maximum plasma concentration of levobupivacaine in the control group (1410 (322) ng.ml(-1) ) was higher than the dextran group (1141 (287) ng.ml(-1) ; p = 0.004), and was reached more quickly (50.6 (30.2) min vs 73.2 (24.6) min; p = 0.006). The area under the plasma concentration-time curve from 0 min to 240 min in the control group (229,124 (87,254) ng.min.ml(-1) ) was larger than in the dextran group (172,484 (50,502) ng.min.ml(-1) ; p = 0.007). The median (IQR [range]) of the summated numerical pain rating score at rest during the first postoperative 24 h in the control group (16 (9-20 [3-31]) was higher than in the dextran group (8 (2-11 [0-18]); p = 0.0001). In this study, adding dextran to levobupivacaine decreased the risk of levobupivacaine toxicity while providing better analgesia.

Dynamical footprint of falcipain-2 catalytic triad in hemoglobin-β-bound state

Falcipain-2 (FP-2) is a member of papain family of cysteine proteases and the major hemoglobinase of the hemoglobin detoxification and hemozoin polymerization complex localized in the food vacuole of the plasmodium species. FP-2 is currently gaining clinical significance as the drug target of choice in combating malaria epidemic. Here, a theoretical FP-2/hemoglobin complex has been proposed and the dynamical footprint and energetics of binding have been investigated using molecular and quantum mechanics approaches. The mapped interaction interface comprises residues 34-51 of hemoglobin and cysteine-42/histidine-174/glutamine-36/asparagine-173/204 and subsites S1, S1', and S3 of FP-2. In hemoglobin-bound FP-2, asparagine-173 preferentially partners histidine-174, while glutamine-36 is preferred in ligand-free state. Cysteine-42 exhibits dihedral switch from 110° to 30° in free and bound states, respectively, with exclusion of water from the binding core upon hemoglobin binding. Hemoglobin similarly exhibits high occupancy within .2 nm distance with charged amido acid-rich subsites S1 and S3 of FP-2 functioning in tandem to reduce conformational flexibility of hemoglobin and facilitate the formation of a stabilizing anti-parallel β-sheet between Leucine-172-valine-176 of FP-2 and phenylalanine-45-asparate-47 of hemoglobin and to overcome the + 1.13e + 5 eV activation energy required to optimize the FP-2/hemoglobin-β conformation that precedes hydrolysis.

Prognostic nomogram for nonresectable pancreatic cancer treated with gemcitabine-based chemotherapy

Background:

A nomogram is progressively being used as a useful predictive tool for cancer prognosis. A nomogram to predict survival in nonresectable pancreatic cancer treated with chemotherapy has not been reported.

Methods:

Using prospectively collected data on patients with nonresectable pancreatic cancer receiving gemcitabine-based chemotherapy at five Japanese hospitals, we derived a predictive nomogram and internally validated it using a concordance index and calibration plots.

Results:

In total, 531 patients were included between June 2001 and February 2013. The American Joint Committee on Cancer (AJCC) TNM stages were III and IV in 204 and 327 patients, respectively. The median survival time of the total cohort was 11.3 months. A nomogram was generated to predict survival probabilities at 6, 12, and 18 months and median survival time, based on the following six variables: age; sex; performance status; tumour size; regional lymph node metastasis; and distant metastasis. The concordance index of the present nomogram was higher than that of the AJCC TNM staging system at 12 months (0.686 vs 0.612). The calibration plots demonstrated good fitness of the nomogram for survival prediction.

Conclusions:

The present nomogram can provide valuable information for tailored decision-making early after the diagnosis of nonresectable pancreatic cancer.

Ultrasound-guided single shot caudal block anesthesia reduces postoperative urinary catheter-induced discomfort

BACKGROUND

Urinary catheter-induced discomfort during the postoperative period can be distressing, and sometimes results in severe restlessness and agitation, especially in middle-aged and elderly male patients. Recent advances in ultrasound technology have increased the consistency, safety, and ease of a caudal block even in older patients. We speculated that an ultrasound-guided caudal block would be reliable and safe as treatment for such postoperative discomfort.

METHODS

Adult male patients (ASA I-II) undergoing cervical laminoplasty were allocated to either the caudal block (CB, N.=24) or non-block (NB, N.=24) group. Following anesthesia induction, urinary catheterization was performed using a 16 French Foley catheter. Thereafter, an ultrasound-guided caudal block was performed with 8 ml of 0.3% ropivacaine and 100 µg of fentanyl for patients in group CB, while group NB did not receive a caudal block. We assessed urinary catheter-induced discomfort as mild, moderate, or severe at 0, 2, 6, 10, and 18 hours after surgery, and compared the incidence and severity of discomfort between the groups using a randomized double-blind design.

RESULTS

All caudal blocks were successfully performed with 1 or 2 needle insertions. The incidence of urinary catheter-induced discomfort was significantly reduced in group CB as compared to NB at 0, 2, and 6 hours, while severity was also reduced at 0 and 2 hours. No patient required re-catheterization due to urinary retention after catheter removal. There were no other complications related to the caudal block.

CONCLUSION

Preoperative ultrasound-guided single shot caudal block anesthesia safely reduced postoperative urinary catheter-induced discomfort in our male patients.

A vasodilating β1 blocker celiprolol inhibits muscular release of uric acid precursor in patients with essential hypertension

Although nonvasodilating β1 blockers increase the levels of uric acid in serum, it is not known whether vasodilating β1 blockers have a similar effect. In the present study, we evaluated the effect of celiprolol on the release of hypoxanthine, a uric acid precursor, from muscles after an exercise. We used the semi-ischemic forearm test to examine the release of lactate (ΔLAC), ammonia (ΔAmm), and hypoxanthine (ΔHX) before and 4, 10, and 60 min after an exercise in 18 hypertensive patients as well as 4 normotensive subjects. Before celiprolol treatment, all the levels of ΔHX and ΔAmm, and ΔLAC were increased by semi-ischemic exercise in hypertensive patients, and the increases were remarkably larger than those in normotensive subjects. Celiprolol decreased both systolic and diastolic pressure. It also decreased the levels of ΔHX and ΔAmm without changes in ΔLAC after an exercise. These findings also were confirmed by summation of each metabolite (ΣΔMetabolites). Celiprolol caused a marginal decrease of serum uric acid, but the difference was not statistically significant. On the other hand, nonvasodilating β1 blockers did not suppress the levels of ΔHX and ΔAmm, whereas they significantly increased ΔLAC after an exercise. Celiprolol improved energy metabolism in skeletal muscles. It suppressed HX production and consequently did not adversely affect serum uric acid levels.