3-Phenyllactic Acid and Polyphenols Are Substances Enhancing the Antibacterial Effect of Methylglyoxal in Manuka Honey.

Manuka honey is known for its unique antibacterial activity, which is due to methylglyoxal (MGO). After establishing a suitable assay for measuring the bacteriostatic effect in a liquid culture with a time dependent and continuous measurement of the optical density, we were able to show that honey differs in its growth retardingeffect on Bacillus subtilis despite the same content of MGO, indicating the presence of potentially synergistic compounds. In model studies using artificial honey with varying amounts of MGO and 3-phenyllactic acid (3-PLA), it was shown that 3-PLA in concentrations above 500 mg/kg enhances the bacteriostatic effect of the model honeys containing 250 mg/kg MGO or more. It has been shown that the effect correlates with the contents of 3-PLA and polyphenols in commercial manuka honey samples. Additionally, yet unknown substances further enhance the antibacterial effect of MGO in manuka honey. The results contribute to the understanding of the antibacterial effect of MGO in honey.

Pharmacokinetics, efficacy and safety of a novel fibrinogen concentrate in pediatric patients with congenital afibrinogenemia.

INTRODUCTION: Congenital afibrinogenemia treatment with plasma-derived fibrinogen concentrates in pediatric patients is limited. This study investigated the pharmacokinetics, surrogate efficacy, and safety of a plasma-derived fibrinogen concentrate (FIB Grifols) in pediatric patients with congenital afibrinogenemia. METHODS: Patients aged <18 years old diagnosed with congenital afibrinogenemia were included in this prospective, multinational, phase 1-2, single-arm study. After a single dose of a plasma-derived fibrinogen concentrate (70 mg/kg body weight), pharmacokinetic parameters were determined from plasma fibrinogen activity (Clauss method) and antigen method (ELISA), and calculated by noncompartmental and population pharmacokinetic (popPK) models. Patients were followed up over 14 days. Efficacy variables were the mean change on thromboelastographic variables (maximum clot firmness [MCF], alpha angle [ α ]) and coagulation tests (prothrombin time, activated partial thromboplastin time, and thrombin time) 1 h postinfusion. Safety parameters were assessed. RESULTS: Eleven patients with a median (range) age 8.80 (3.7-12.7) years were treated with the plasma-derived fibrinogen concentrate. Using the popPK modeling, fibrinogen activity reached a mean (standard deviation) Cmax of 1.3 (0.225) g/l, half-life ( t1/2 ) of 60.6 (4.48) h and incremental in vivo recovery (IVR) of 1.86 (0.322) (mg/dl)/(mg/kg). Surrogate efficacy was demonstrated by significant increase in MCF (9.23 [3.94] mm; P  < 0.001; 95% confidence interval 6.58, 11.87). All coagulation times were significantly shortened after fibrinogen concentrate infusion. Adverse events were mild or moderate in severity, and unrelated to fibrinogen concentrate. CONCLUSIONS: In pediatric patients with congenital afibrinogenemia, plasma-derived fibrinogen concentrate revealed a favorable and specific pharmacokinetic profile, demonstrated efficacy in coagulation and was safe and well tolerated.

Pharmacokinetics, surrogate efficacy and safety evaluations of a new human plasma-derived fibrinogen concentrate (FIB Grifols) in adult patients with congenital afibrinogenemia.

BACKGROUND AND AIMS: Congenital afibrinogenemia is a rare coagulation disorder resulting from a deficiency in fibrinogen. This study assessed the pharmacokinetics, surrogate efficacy and safety of FIB Grifols, a new human plasma-derived fibrinogen concentrate, to treat congenital afibrinogenemia. METHODS: Eleven adult patients from a multinational, phase 1-2, prospective, open-label, single-arm, uncontrolled clinical study received a single infusion of FIB Grifols, 70 mg/kg bw. Fibrinogen pharmacokinetics (fibrinogen activity: Clauss method; antigen plasma concentrations: ELISA) and efficacy parameters were determined over 14 days after infusion. Efficacy endpoints were the mean change on plasma maximum clot firmness (MCF) on viscoelastic testing and coagulation tests 1-hour post-infusion, and correlation with fibrinogen levels throughout. Safety parameters were also assessed. RESULTS: For the Clauss method, (mean [standard deviation]) baseline adjusted Cmax was 1.99 (0.40) g/L, reached 1.76 (1.00) h after infusion, and half-life was 76.94 (20.21) h. Using ELISA, Cmax after FIB Grifols infusion was 2.88 (0.86) mg/mL, with a tmax of 3.06 (2.24) h. Fibrinogen activity and antigen concentrations showed statistically significant correlation of 0.9120 (P < 0.001). Surrogate efficacy was demonstrated by a significant increase of 12.35 (3.85) mm in MCF. Prothrombin time, activated partial thromboplastin time and thrombin time, returned to normal ranges over time, indicating restoration of functionally active fibrinogen. There were no treatment-related adverse events, allergic reactions, serious adverse events, or discontinuations. CONCLUSIONS: The pharmacokinetic profile of functionally active FIB Grifols was established, hemostasis was restored, and FIB Grifols was safe and well tolerated in fibrinogen-deficient patients.

Serum Methotrexate Level and Side Effects of High Dose Methotrexate Infusion in Pediatric Patients with Acute Lymphoblastic Leukaemia (ALL).

Methotrexate (MTX) is an extensively prescribed antimetabolite especially in the treatment of several pediatric cancers, though managing toxicities associated with methotrexate in high dose continues to be a challenge. A prospective study was carried out from April 2017 to October 2018. Children of either sex below 18 years at the time of enrolment and receiving high dose Methotrexate intravenous infusion over 24 h as a 2 g/m2, 3 g/m2 and 5 g/m2 dose was included in the study. The serum methotrexate level was estimated after the start of 48 h HDMTX infusion by using the ARCHITECT methotrexate assay. Toxicity due to HDMTX was assessed by Common Terminology Criteria for Adverse Events v.5.0. A total of 244 HDMTX infusions were delivered to 62 ALL patients. From the total of 244 cycles, serum methotrexate level in 35 cycles after the start of 48 h HDMTX infusion was found to be ≥ 1.0 µmol/L with reported toxicities among 31 cycles (88.6%). In 209 cycles MTX level was found to be less than 1.0 is statistically significant as compared to other cycles (p < 0.0001). Highest toxicities reported were in cycle I (38.8%). The toxicities such as oral mucositis, neutropenia, the elevation of liver enzymes, dermatological toxicities were found more in cycles whose methotrexate level are greater than 1.0 µmol/L. Dose reduction, increased the length of stay and treatment delay occurred in patients with severe toxicities. Severe toxicities of methotrexate can be interrelated with serum methotrexate levels at 48 h after the start of HDMTX infusion.

Fibrinogen concentrate for treatment of bleeding and surgical prophylaxis in congenital fibrinogen deficiency patients.

BACKGROUND: Congenital fibrinogen deficiency is an ultra-rare disorder in which patients can experience severe and/or frequent bleeding episodes (BEs). Here, we present the largest prospective study to date on the treatment of this disorder. METHODS: Hemostatic efficacy of human fibrinogen concentrate (HFC; FIBRYGA® , Octapharma AG) for treatment of bleeding or surgical prophylaxis was assessed by investigators and adjudicated by an independent data monitoring and endpoint adjudication committee (IDMEAC) according to a four-point scale, using objective criteria. Thromboelastometry maximum clot firmness (MCF) was also determined. RESULTS: Twenty-five afibrinogenemia patients were treated with HFC: 24 for on-demand treatment of 89 BEs, and nine as prophylaxis for 12 surgeries. For BEs, treatment success (rating of excellent or good) evaluated by investigators was 96.6% (90% confidence interval [CI], 0.92-0.99; two missing ratings, classified as failures) and by the IDMEAC was 98.9% (90% CI, 0.95-0.999). Mean ± standard deviation (SD) increase in MCF was 5.8 ± 2.5 mm one hour after the first HFC infusion (mean ± SD dose, 61.88 ± 11.73 mg/kg). For the 12 surgeries (median [range] HFC dose/surgery, 85.80 mg/kg [34.09-225.36]), intraoperative and postoperative treatment success were both rated 100% (90% CI, 0.82-1.00) by investigators and the IDMEAC. Three adverse events were possibly treatment related, including a moderate case of thrombosis. There were no deaths, no severe allergic or hypersensitivity reactions, and no clinical evidence of neutralizing antifibrinogen antibodies. CONCLUSIONS: Human fibrinogen concentrate was efficacious for on-demand treatment of bleeding and as surgical prophylaxis, with a favorable safety profile, in patients with congenital afibrinogenemia.

Correlation of Day 8 Steroid Response with Bone Marrow Status Measured on Days 14 and 35, in Patients with Acute Lymphoblastic Leukemia Being Treated with BFM Protocol.

Berlin-Frankfurt-Munster (BFM) protocol is commonly used in India for treatment of acute lymphoblastic leukemia (ALL). The present study was conducted to correlate day 8 steroid response with bone marrow status (by morphology and flow cytometry) at day 14 and day 35 of treatment. It was a prospective study which included all newly diagnosed ALL patients who visited hospital between March 2013 and February 2015 i.e. 2 years. On 8th day, the number of lymphoblasts was counted in the peripheral blood. Based on the number of blasts patients were classified as good steroid responders and poor steroid responders. Following pre-induction steroids patients were given induction therapy. During this phase on day 14 and day 35 bone marrow (BM) aspiration study was done. Later day 8 steroid response, Day 14 BM status and day 35 BM status were correlated. Results showed that there was a statistically significant correlation between day 8 steroid response and day 14 BM status (both by morphology and flow cytometry). There was no statistically significant correlation between day 8 steroid response and day 35 BM status (both by morphology and flow cytometry). There was no statistically significant correlation between day 14 and day 35 BM status (both by morphology and flow cytometry). Sensitivity and specificity of morphological evaluation of BM was much lower compared to minimal residual disease assessment by flow cytometry. There is a need to incorporate flow cytometry in risk stratification of patients who are being treated with BFM 2002 protocol.

Insulin receptor-insulin interaction kinetics using multiplex surface plasmon resonance.

Type 2 diabetes affects millions of people worldwide, and measuring the kinetics of insulin receptor-insulin interactions is critical to improving our understanding of this disease. In this paper, we describe, for the first time, a rapid, real-time, multiplex surface plasmon resonance (SPR) assay for studying the interaction between insulin and the insulin receptor ectodomain, isoform A (eIR-A). We used a scaffold approach in which anti-insulin receptor monoclonal antibody 83-7 (Abcam, Cambridge, UK) was first immobilized on the SPR sensorchip by amine coupling, followed by eIR-A capture. The multiplex SPR system (ProteOn XPR36™, Bio-Rad Laboratories, Hercules, CA) enabled measurement of replicate interactions with a single, parallel set of analyte injections, whereas repeated regeneration of the scaffold between measurements caused variable loss of antibody activity. Interactions between recombinant human insulin followed a two-site binding pattern, consistent with the literature, with a high-affinity site (dissociation constant K(D1) = 38.1 ± 0.9 nM) and a low-affinity site (K(D2) = 166.3 ± 7.3 nM). The predominantly monomeric insulin analogue Lispro had corresponding dissociation constants K(D1) = 73.2 ± 1.8 nM and K(D2) = 148.9 ± 6.1 nM, but the fit to kinetic data was improved when we included a conformational change factor in which the high-affinity site was converted to the low-affinity site. The new SPR assay enables insulin-eIR-A interactions to be followed in real time and could potentially be extended to study the effects of humoral factors on the interaction, without the need for insulin labeling.

Cloning and expression of S-Adenosyl Methionine Synthetase gene in recombinant E. coli strain for large scale production of SAMe

S-Adenosyl Methionine (SAMe) Synthetase is an enzyme which catalyses the synthesis of S-Adenosyl Methionine using methionine and ATP. It is also known as AdoMet which is well known methyl donor, which modifies DNA, RNA, histones and other proteins, dictating replicational, transcriptional and translational fidelity, mismatch repair, chromatin modeling, epigenetic modifications and imprinting. The objective of the present work is to clone the SAMe Synthetase gene in recombinant E. coli strain in order to express, characterize and purify it for further synthesis of SAMe in a large scale fermentation. Expression was induced by 1 mM IPTG and expressed protein was characterized by SDS-PAGE. The recombinant E. coli cells were used for the production of SAMe through batch and fed batch fermentation operations. The produced SAMe was purified through paper chromatography in order to use it in our future studies.

Development of a less toxic dichloroacetate analogue by docking and descriptor analysis.

Dichloroacetate (DCA) is a synthetic compound that promotes the activity of pyruvate dehydrogenase (PDH) by inhibiting its repressor protein called pyruvate dehydrogenase kinase (PDHK). The activation of PDH leads to a reduction in ambient cellular lactate concentrations both in vitro and in vivo which contributes to the therapeutic use of DCA in the treatment of systemic lactic acidosis in humans. The therapeutic potential of DCA is now being explored in disorders that are accompanied by elevations of lactate concentration such as in hypoxic cancer cells. Yet conflicting evidence regarding its mutagenic potential has been a major setback in its clinical trials. Hence, docking and descriptor analysis of halogen substituted DCA analogues were performed to find out a drug candidate with less toxicity and better binding affinity than DCA. The Docking analysis was carried out using human PDHK isozyme 2, the physiological receptor for DCA. Bromo(iodo)acetate and Diiodoacetate were found out to be the plausible analogues of DCA from this study.