A methodology was implemented for purifying peptides in one chromatographic run via solid-phase extraction (SPE), reverse phase mode (RP), and gradient elution, obtaining high-purity products with ...good yields. Crude peptides were analyzed by reverse phase high performance liquid chromatography and a new mathematical model based on its retention time was developed in order to predict the percentage of organic modifier in which the peptide will elute in RP-SPE. This information was used for designing the elution program of each molecule. It was possible to purify peptides with different physicochemical properties, showing that this method is versatile and requires low solvent consumption, making it the least polluting one. Reverse phase-SPE can easily be routinely implemented. It is an alternative to enrich and purified synthetic or natural molecules.
Summary Background Many patients with advanced type 2 diabetes do not meet their glycated haemoglobin targets and randomised controlled studies comparing the efficacy of pump treatment and multiple ...daily injections for lowering glucose in insulin-treated patients have yielded inconclusive results. We aimed to resolve this uncertainty with a randomised controlled trial (OpT2mise). Methods We did this multicentre, controlled trial at 36 hospitals, tertiary care centres, and referal centres in Canada, Europe, Israel, South Africa, and the USA. Patients with type 2 diabetes who had poor glycaemic control despite multiple daily injections with insulin analogues were enrolled into a 2-month dose-optimisation run-in period. After the run-in period, patients with glycated haemoglobin of 8·0–12·0% (64–108 mmol/mol) were randomly assigned (1:1) by a computer-generated randomisation sequence (block size 2 with probability 0·75 and size 4 with probability 0·25) to pump treatment or to continue with multiple daily injections. Neither patients nor investigators were masked to treatment allocation. The primary endpoint was change in mean glycated haemoglobin between baseline and end of the randomised phase for the intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT01182493. Findings 495 of 590 screened patients entered the run-in phase and 331 were randomised (168 to pump treatment, 163 to multiple daily injections). Mean glycated haemoglobin at baseline was 9% (75 mmol/mol) in both groups. At 6 months, mean glycated haemoglobin had decreased by 1·1% (SD 1·2; 12 mmol/mol, SD 13) in the pump treatment group and 0·4% (SD 1·1; 4 mmol/mol, SD 12) in the multiple daily injection group, resulting in a between-group treatment difference of −0·7% (95% CI −0·9 to −0·4; −8 mmol/mol, 95% CI −10 to −4, p<0·0001). At the end of the study, the mean total daily insulin dose was 97 units (SD 56) with pump treatment versus 122 units (SD 68) for multiple daily injections (p<0·0001), with no significant difference in bodyweight change between the two groups (1·5 kg SD 3·5 vs 1·1 kg 3·6, p=0·322). Two diabetes-related serious adverse events (hyperglycaemia or ketosis without acidosis) resulting in hospital admission occurred in the pump treatment group compared with one in the multiple daily injection group. No ketoacidosis occurred in either group and one episode of severe hypoglycaemia occurred in the multiple daily injection group. Interpretation In patients with poorly controlled type 2 diabetes despite using multiple daily injections of insulin, pump treatment can be considered as a safe and valuable treatment option. Funding Medtronic.
Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, ...MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against
ATCC 11775,
ATCC 13636, and
ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against
ATCC 11775 and
ATCC 13076. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against
ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by
.
Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and ...MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against
(ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.
IntroductionFor many people with type 1 diabetes who struggle to achieve glycaemic control with multiple daily injections of insulin (MDI) plus self-monitoring of blood glucose, MDI plus ...intermittently scanned continuous glucose monitoring (IS-CGM) or real-time continuous glucose monitoring (RT-CGM), or insulin administration using insulin pump therapy represent optimised care in many regions. Through technological advances an advanced hybrid closed loop (AHCL) system has been developed; studies of incremental effects relative to MDI plus IS-CGM are lacking.Methods and analysisThe Advanced Hybrid Closed Loop study in Adult Population with Type 1 Diabetes (ADAPT) study is a multinational, prospective, open-label, confirmatory and exploratory randomised controlled trial to examine outcomes with the MiniMed 670G version 4.0 AHCL system (with an equivalent algorithm and commercialised as the MiniMed 780G system, referred to as AHCL) relative to MDI plus IS-CGM in adults with baseline HbA1c≥8.0%. An exploratory cohort will compare AHCL with MDI plus RT-CGM. The study will be conducted in approximately 124 adults on MDI plus either IS-CGM or RT-CGM for at least 3 months prior to screening. The primary endpoint will be the difference in mean HbA1c change from baseline to 6 months between the AHCL and the MDI plus IS-CGM arms. Secondary endpoints will include proportion of time spent in hypoglycaemic, euglycaemic and hyperglycaemic ranges.Ethics and disseminationThe ADAPT study will be conducted in accordance with the requirements of the Declaration of Helsinki and local laws and regulations, and has been approved by ethics committees. The trial will provide valuable information on the incremental benefits that may be provided by AHCL for patients failing to achieve glycaemic targets on MDI plus IS-CGM or RT-CGM and form a basis for health economic evaluations to support market access.Trial registration numberNCT04235504; Pre-results.
Peptides derived from LfcinB were designed and synthesized, and their antibacterial activity was tested against
Escherichia coli
ATCC 25922 and
Staphylococcus aureus
ATCC 25923. Specifically, a ...peptide library was constructed by systemically removing the flanking residues (N or C-terminal) of Lfcin 17–31 (
17
FKCRRWQWRMKKLGA
31
), maintaining in all peptides the
20
RRWQWR
25
sequence that corresponds to the minimal antimicrobial motif. For this research, also included were (i) a peptide containing an Ala instead of Cys (Ala
19
-LfcinB 17–31) and (ii) polyvalent peptides containing the RRWQWR sequence and a non-natural amino acid (aminocaproic acid). We established that the lineal peptides LfcinB 17–25 and LfcinB 17–26 exhibited the greatest activity against
E. coli
ATCC 25922 and
S. aureus
ATCC 25923, respectively. On the other hand, polyvalent peptides, a dimer and a tetramer, exhibited the greatest antibacterial activity, indicating that multiple copies of the sequence increase the activity. Our results suggest that the dimeric and tetrameric sequence forms potentiate the antibacterial activity of lineal sequences that have exhibited moderate antibacterial activity.
The MiniMed™ 780G system includes an advanced hybrid closed loop (AHCL) algorithm that provides both automated basal and correction bolus insulin delivery. The preliminary performance of the system ...in real-world settings was evaluated.
Data uploaded from August 2020 to March 2021 by individuals living in Belgium, Finland, Italy, the Netherlands, Qatar, South Africa, Sweden, Switzerland, and the United Kingdom were aggregated and retrospectively analyzed to determine the mean glucose management indicator (GMI), percentage of time spent within (TIR), below (TBR), and above (TAR) glycemic ranges, system use, and insulin consumption in users having ≥10 days of sensor glucose (SG) data after initiating AHCL. The impact of initiating AHCL was evaluated in a subgroup of users also having ≥10 days of SG data, before AHCL initiation.
Users (
= 4120) were observed for a mean of 54 ± 32 days. During this time, they spent a mean of 94.1% ± 11.4% of the time in AHCL and achieved a mean GMI of 6.8% ± 0.3%, TIR of 76.2% ± 9.1%, TBR <70 of 2.5% ± 2.1%, and TAR >180 of 21.3% ± 9.4%, after initiating AHCL. There were 77.3% and 79.0% of users who achieved a TIR >70% and a GMI of <7.0%, respectively. Users for whom comparison with pre-AHCL was possible (
= 812) reduced their GMI by 0.4% ± 0.4% (
= 0.005) and increased their TIR by 12.1% ± 10.5% (
< 0.0001), post-AHCL initiation. More users achieved the glycemic treatment goals of GMI <7.0% (37.6% vs. 75.2%,
< 0.0001) and TIR >70% (34.6% vs. 74.9%,
< 0.0001) when compared with pre-AHCL initiation.
Most MiniMed 780G system users achieved TIR >70% and GMI <7%, while minimizing hypoglycemia, in a real-world condition.
Peptides are very diverse molecules that can participate in a wide variety of biological processes. In this way, peptides are attractive for doping, since these molecules can activate or trigger ...biological processes that can improve the sports performance of athletes. Peptide molecules are found in the official World Anti-Doping Agency lists, mainly in sections S2, S4, and S5. In most cases, these molecules have a very short half-life in the body and/or are identical to natural molecules in the body, making it difficult to analyze them as performance-enhancing drugs. This article reviews the role of peptides in doping, with special emphasis on the peptides used as reference materials, the pretreatment of samples in biological matrices, the instrumentation, and the validation of analytical methodologies for the analysis of peptides used in doping. The growing need to characterize and quantify these molecules, especially in complex biological matrices, has generated the need to search for robust strategies that allow for obtaining sensitive and conclusive results. In this sense, strategies such as solid phase peptide synthesis (SPPS), seeking to obtain specific peptides, metabolites, or isotopically labeled analogs, is a key tool for adequate quantification of different peptide molecules in biological matrices. This, together with the use of optimal methodologies for sample pretreatment (e.g., SPE or protein precipitation), and for subsequent analysis by high-resolution techniques (mainly hyphenated LC-HRMS techniques), have become the preferred instrumentation to meet the analytical challenge involved in the analysis of peptides in complex matrices.
The cytotoxic effect against the breast cancer cell line MDA-MB-468 of the palindromic peptide LfcinB (21-25)
Pal
:
1
RWQWRWQWR
9
and its analogous peptides, obtained
via
alanine scanning, was ...evaluated. The results indicate that the palindromic peptide exhibited a concentration-dependent cytotoxic effect against this cell line. The cytotoxic effect of the palindromic peptide was fast and selective and was sustained for up to 48 h of treatment. MDA-MB-468 cells treated with the palindromic peptide exhibited severe cellular damage, acquiring rounded forms and shrinkage, a behavior typical of apoptotic events. The analogous peptides exhibited fewer cytotoxic effects than the original palindromic peptide, suggesting that the substitution of any amino acid with alanine diminishes the cytotoxic effect. The Arg and Trp residues proved to be the most relevant for the cytotoxic effect; the analogous peptides with substitutions of Trp with Ala did not induce a change in cellular morphology, while analogous peptides with substitutions of Arg or Gln with Ala induced cellular damage. Also, neither the palindromic peptide nor its analogues exerted a significant cytotoxic effect on normal fibroblasts, indicating that the peptides had a selective cytotoxic effect on cancerous cells. The peptide LfcinB (21-25)
Pal
, and its analogues exhibited antibacterial activity against
E. coli
and
S. aureus
strains and a selective cytotoxic effect against the breast cancer cell line MDA-MB-468.
The cytotoxic effect against the breast cancer cell line MDA-MB-468 of the palindromic peptide LfcinB (21-25)
Pal
:
1
RWQWRWQWR
9
and its analogous peptides, obtained
via
alanine scanning, was evaluated.
Periodontitis has been linked to obstructive sleep apnea (OSA). The stage III periodontitis is more prevalent in OSA severe and the oral microbiome changes due to an increase in periodontal ...pathogenic bacteria and C. albicans. Nanofiber drug delivery systems may be used for local antimicrobial therapy against microorganisms related to periodontitis and OSA. The aim of the present study was manufacture PCL/PLGA nanofibers incorporating an antifungal, Amphotericin B (AMB); an antimicrobial peptide, LfcinB (21–25)Pal (P61); and zinc oxide (ZnO), for the inhibition of in vitro polymicrobial biofilms. Nanofibers (Nf) were produced by electrospinning method: PCL/PLGA Nf loaded with: AMB (Nf 1), AMB-ZnO (Nf 2), P61 (Nf 3), P61–ZnO (Nf 4), AMB-P61 (Nf 5), AMB-P61-ZnO (Nf 6) and ZnO (Nf 7). Different methods were used to physically and chemically characterize the nanofibers. The cell viability of human periodontal ligament fibroblasts (HPdLF) treated with the nanofibers was higher than 50%, demonstrating the biocompatibility of the nanofibers obtained. The antimicrobial and anti-biofilm activities of the nanofibers were assessed using qualitative and quantitative analyses. Nine bacteria viability, Candida albicans viability, and biofilm formation were significantly inhibited by the Nf 6, and this effect increased with exposure time (72 h). The AMB-P61-ZnO-loaded PCL/PLGA nanofiber (Nf 6) may offer a promising strategy for treating localized cases of periodontitis in those with obstructive sleep apnea.
Display omitted