Evaluation of Pharmacokinetic and Pharmacodynamic (PK/PD) of Novel Fluorenylmethoxycarbonyl- Phenylalanine Antimicrobial Agent.

OBJECTIVE: To assess the pharmacokinetic profile, in-vivo toxicity, and efficacy of 9-Fluorenylmethoxycarbonyl-L-phenylalanine (Fmoc-F) as a potential antibacterial agent, with a focus on its suitability for clinical translation. METHODS: An RP-HPLC-based bio-analytical method was developed and qualified to quantify Fmoc-F levels in mouse plasma for pharmacokinetic analysis. Oral bioavailability was determined, and in-vivo toxicity was evaluated following intra-peritoneal administration. Efficacy was assessed by measuring the reduction in Staphylococcus aureus burden and survival rates in BALB/c mice. RESULTS: The RP-HPLC method is highly sensitive, detecting as low as 0.8 µg mL-1 (~ 2 µM) of Fmoc-F in blood plasma. This study revealed that Fmoc-F has an oral bioavailability of 65 ± 18% and suitable pharmacokinetic profile. Further, we showed that intra-peritoneal administration of Fmoc-F is well tolerated by BALB/c mice and Fmoc-F treatment (100 mg/kg, i.p.) significantly reduces Staphylococcus aureus burden from visceral organs in BALB/c mice but falls short in enhancing survival rates at higher bacterial loads. CONCLUSIONS: The study provides crucial insights into the pharmacokinetic and pharmacodynamic properties of Fmoc-F. The compound displayed favourable oral bioavailability and in-vivo tolerance. Its significant reduction of bacterial burden underscores its potential as a treatment for systemic infections. However, limited effectiveness for severe infections, short half-life, and inflammatory response at higher doses need to be addressed for its clinical application.

A collagen domain-derived short adiponectin peptide activates APPL1 and AMPK signaling pathways and improves glucose and fatty acid metabolisms.

Adiponectin is a fat tissue-derived adipokine with beneficial effects against diabetes, cardiovascular diseases, and cancer. Accordingly, adiponectin-mimetic molecules possess significant pharmacological potential. Oligomeric states of adiponectin appear to determine its biological activity. We identified a highly conserved, 13-residue segment (ADP-1) from adiponectin's collagen domain, which comprises GXXG motifs and has one asparagine and two histidine residues that assist in oligomeric protein assembly. We therefore hypothesized that ADP-1 promotes oligomeric assembly and thereby mediates potential metabolic effects. We observed here that ADP-1 is stable in human serum and oligomerizes in aqueous environments. We also found that ADP-1 activates AMP-activated protein kinase (AMPK) in an adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1)-dependent pathway and stimulates glucose uptake in rat skeletal muscle cells (L6 myotubes). ADP-1-induced glucose transport coincided with ADP-1-induced biosynthesis of glucose transporter 4 and its translocation to the plasma membrane. ADP-1 induced an interaction between APPL1 and the small GTPase Rab5, resulting in AMPK phosphorylation, in turn leading to phosphorylation of p38 mitogen-activated protein kinase (MAPK), acetyl-CoA carboxylase, and peroxisome proliferator-activated receptor α. Similar to adiponectin, ADP-1 increased the expression of the adiponectin receptor 1 (AdipoR1) gene. Of note, ADP-1 decreased blood glucose levels and enhanced insulin production in pancreatic ß cells in db/db mice. Further, ADP-1 beneficially affected lipid metabolism by enhancing lipid globule formation in mouse 3T3-L1 adipocytes. To our knowledge, this is the first report on identification of a short peptide from adiponectin with positive effects on glucose or fatty acid metabolism.

Extraskeletal Myxoid Chondrosarcoma of Floor of Mouth-A Rare Case Report and Review of Literature.

Introduction: Chondrosarcomas are rare malignancies of the cartilage and myxoid chondrosarcoma is its variant which commonly occurs in soft tissue of extremities. Extraskeletal chondrosarcoma is a rare malignant neoplasm of bone or soft tissue origin and is characterized by the presence of spindle cells admixed with well differentiated cartilage or chondroid stroma. They are mostly radioresistant tumours and surgical resections with adequate margins is considered as the ideal treatment modality with adjuvant radiotherapy in high grade tumours and add on chemotherapy, in case of presence of poor prognostic factors. Case Report: A 51-year-old diabetic, hypertensive female patient presented to our outpatient department with difficulty in chewing food for a duration of 6 months. On clinical examination, she had an ulceroproliferative growth involving right lower alveolus and floor of mouth. MRI face and neck with contrast showed a 4.1 × 2.9 × 4.5 cm lesion involving right lower alveolus extending to floor of mouth. Biopsy showed features of extraskeletal myxoid chondrosarcoma. She was planned for upfront surgery (Right composite resection with modified radical neck dissection with free fibula flap). Patient was stable post-surgery and was discharged in stable condition. Final histopathology report was high grade myxoid chondrosarcoma. The case was presented in tumour board and the patient was planned for adjuvant radiotherapy. She has been on regular follow up for the past 2 years and shows no signs of recurrence. Conclusion: Extraskeletal myxoid chondrosarcoma of oral cavity is a rare entity and very few cases are reported. It is a malignant neoplasm which is diagnosed with the help of immunohistochemistry. Surgery is the ideal modality of treatment accompanied by adjuvant radiotherapy in cases of high-grade tumours.

Robotic Neck Dissection in Head and Neck Cancer via Modified BABA Technique.

INTRODUCTION: Neck dissection forms an important component in the surgical management of head and neck cancers. By using the conventional techniques of neck dissection, a conspicuous scar is inevitable for the patients. The development of robotic assisted neck dissection provides for a scar-free neck along with good oncological and functional outcomes. METHODS: A prospective observational study was conducted in our institute from 2020 March to 2022 March, where robotic-assisted neck dissections performed via the modified bilateral axillo-breast insufflation technique. RESULTS: Eighty-two patients underwent robotic neck dissections in our institute. Notably, 79 patients were treatment-naïve. The average docking time was 12 min and console time was 160 ± 15 min. The mean lymph node yield was 28.2. The average post-operative stay was 5.6 days. The average follow-up was noted to be 6.4 months. The mean cosmetic satisfaction score in our patients was 4.45. Only one patient presented with nodal recurrence, who was identified as a defaulter for adjuvant treatment. Robotic neck dissection gives similar functional and oncological outcomes as compared with conventional neck dissection. Patients had excellent cosmetic satisfaction following the procedure. The limitations of these techniques include high cost of procedure and longer operating time. This is a level IV evidence study. CONCLUSION: Although good oncological, functional, and cosmetic outcomes have been attained in robotic assisted neck dissection, further randomized controlled studies need to be conducted to justify the added costs, cosmetic advantage, and the time taken. LEVEL OF EVIDENCE: IV Laryngoscope, 134:4045-4051, 2024.

Myofibrosarcoma of Maxilla - Case Report and Review of Literature.

Myofibrosarcoma is a distinct mesenchymal malignancy which commonly occurs in head and neck region. It has a high tendency for local recurrence and distant metastasis. 39-year-old male presented with epistaxis, nasal obstruction and left sided complete loss of vision. He underwent functional endoscopic sinus surgery and guided biopsy. MRI scan showed a lesion epicentred in the left maxillary sinus, superiorly extending into the orbit. He underwent Class 4b maxillectomy with neck dissection, tracheostomy and free flap reconstruction. Histopathological examination yielded final diagnosis as myofibrosarcoma of maxilla. The patient was planned for adjuvant radiotherapy and has been disease free for 3 years.

Spermine-Conjugated Short Proline-Rich Lipopeptides as Broad-Spectrum Intracellular Targeting Antibacterial Agents.

Toward the design of new proline-rich peptidomimetics, a short peptide segment, present in several proline-rich antimicrobial peptides (AMPs), was selected. Fatty acids of varying lengths and spermine were conjugated at the N- and C-terminals of the peptide, respectively. Spermine-conjugated lipopeptides, C10-PR-Spn and C12-PR-Spn, exhibited minimum inhibitory concentrations within 1.5-6.2 µM against the tested pathogens including resistant bacteria and insignificant hemolytic activity against human red blood cells up to 100 µM concentrations and demonstrated resistance against trypsin digestion. C10-PR-Spn and C12-PR-Spn showed synergistic antimicrobial activity against multidrug-resistant methicillin-resistant Staphylococcus aureus with several tested antibiotics. These lipopeptides did not permeabilize bacterial membrane-mimetic lipid vesicles or damage the Escherichia coli membrane like the nonmembrane-lytic AMP, buforin-II. The results suggested that C10-PR-Spn and C12-PR-Spn could interact with the 70S ribosome of E. coli and inhibit its protein synthesis. C10-PR-Spn and C12-PR-Spn demonstrated superior clearance of bacteria from the spleen, liver, and kidneys of mice, infected with S. aureus ATCC 25923 compared to levofloxacin.

10-Residue MyD88-Peptide Adopts ß-Sheet Structure, Self-Assembles, Binds to Lipopolysaccharides, and Rescues Mice from Endotoxin-Mediated Lung-Infection and Death.

Naturally occurring cationic antimicrobial peptides (AMPs) mostly adopt α-helical structures in bacterial membrane mimetic environments. To explore the design of novel ß-sheet AMPs, we identified two short cationic amphipathic ß-strand segments from the crystal structure of the innate immune protein, MyD88. Interestingly, of these, the 10-residue arginine-valine-rich synthetic MyD88-segment, KRCRRMVVVV (M3), exhibited ß-sheet structure when bound to the outer membrane Gram-negative bacterial component, LPS. Isothermal titration calorimetric data showed that M3 bound to LPS with high affinity, and the interaction was hydrophobic in nature. Supporting these observations, computational studies indicated strong interactions of multiple and consecutive valine residues of M3 with the acyl chain of LPS. Moreover, M3 adopted nanosheet and nanofibrillar structure in 25% acetonitrile/water and isopropanol, respectively. M3 showed substantial antibacterial activities against both Gram-positive and Gram-negative bacteria which it appreciably retained in the presence of human serum and physiological salts. M3 was non-hemolytic against human red blood cells and non-cytotoxic to 3T3 cells up to 200 µM and to mice in vivo at a dose of 40 mg/kg. Furthermore, M3 neutralized LPS-induced pro-inflammatory responses in THP-1 cells and rat bone marrow-derived macrophages. Consequently, M3 attenuated LPS-mediated lung inflammation in mice and rescued them (80% survival at 10 mg/kg dose) against a lethal dose of LPS. The results demonstrate the identification of a 10-mer LPS-interacting, ß-sheet peptide from MyD88 with the ability to form nanostructures and in vivo activity against LPS challenge in mice. The identified M3-template provides scope for designing novel bioactive peptides with ß-sheet structures and self-assembling properties.

Self-Assembling Nano-Globular Peptide from Human Lactoferrin Acts as a Systemic Enhancer of Bone Regeneration: A Novel Peptide for Orthopedic Application.

A technology for systemic and repeated administration of osteogenic factors for orthopedic use is an unmet medical need. Lactoferrin (∼80 kDa), present in milk, is known to support bone growth. We discovered a lactoferrin-mimetic peptide, LP2 (an 18-residue fragment from the N-terminus of the N-lobe of human lactoferrin), which self-assembles into a nano-globular assembly with a ß-sheet structure in an aqueous environment. LP2 is non-hemolytic and non-cytotoxic against human red blood cells and 3T3 fibroblasts, respectively, and appreciably stable in the human serum. LP2 through the bone morphogenetic protein-dependent mechanism stimulates osteoblast differentiation more potently than the full-length protein as well as the osteoblastic production of osteoprotegerin (an anti-osteoclastogenic factor). Consequently, daily subcutaneous administration of LP2 to rats and rabbits with osteotomy resulted in faster bone healing and stimulated bone formation in rats with a low bone mass more potently than that with teriparatide, the standard-of-care osteogenic peptide for osteoporosis. LP2 has skeletal bioavailability and is safe at the 15× osteogenic dose. Thus, LP2 is a novel peptide that can be administered systemically for the medical management of hard-to-heal fractures.

Tandem Repeat of a Short Human Chemerin-Derived Peptide and Its Nontoxic d-Lysine-Containing Enantiomer Display Broad-Spectrum Antimicrobial and Antitubercular Activities.

To design novel antimicrobial peptides by utilizing the sequence of the human host defense protein, chemerin, a seven-residue amphipathic stretch located in the amino acid region, 109-115, was identified, which possesses the highest density of hydrophobic and positively charged residues. Although this 7-mer peptide was inactive toward microorganisms, its 14-mer tandem repeat (Chem-KVL) was highly active against different bacteria including methicillin-resistant Staphylococcus aureus, a multidrug-resistant Staphylococcus aureus strain, and slow- and fast-growing mycobacterial species. The selective enantiomeric substitutions of its two l-lysine residues were attempted to confer cell selectivity and proteolytic stability to Chem-KVL. Chem-8dK with a d-lysine replacement in its middle (eighth position) showed the lowest hemolytic activity against human red blood cells among Chem-KVL analogues and maintained high antimicrobial properties. Chem-8dK showed in vivo efficacy against Pseudomonas aeruginosa infection in BALB/c mice and inhibited the development of resistance in this microorganism up to 30 serial passages and growth of intracellular mycobacteria in THP-1 cells.

A Noncytotoxic Temporin L Analogue with In Vivo Antibacterial and Antiendotoxin Activities and a Nonmembrane-Lytic Mode of Action.

Cytotoxic frog antimicrobial peptide Temporin L (TempL) is an attractive molecule for the design of lead antimicrobial agents due to its short size and versatile biological activities. However, noncytotoxic TempL variants with desirable biological activities have rarely been reported. TempL analogue Q3K,TempL is water-soluble and possesses a significant antiendotoxin property along with comparable cytotoxicity to TempL. A phenylalanine residue, located at the hydrophobic face of Q3K,TempL and the "d" position of its phenylalanine zipper sequence, was replaced with a cationic lysine residue. This analogue, Q3K,F8K,TempL, showed reduced hydrophobic moment and was noncytotoxic with lower antimicrobial activity. Interestingly, swapping between tryptophan at the fourth and serine at the sixth positions turned Q3K,F8K,TempL totally amphipathic as reflected by its helical wheel projection with clusters of hydrophobic and hydrophilic residues and the highest hydrophobic moment among these peptides. Surprisingly, this analogue, SW,Q3K,F8K,TempL, was as noncytotoxic as Q3K,F8K,TempL but showed augmented antimicrobial and antiendotoxin properties, comparable to that of TempL and Q3K,TempL. SW,Q3K,F8K,TempL exhibited appreciable survival of mice against P. aeruginosa infection and a lipopolysaccharide (LPS) challenge. Unlike TempL and Q3K,TempL, SW,Q3K,F8K,TempL adopted an unordered secondary structure in bacterial membrane mimetic lipid vesicles and did not permeabilize them or depolarize the bacterial membrane. Overall, the results demonstrate the design of a nontoxic TempL analogue that possesses clusters of hydrophobic and hydrophilic residues with impaired secondary structure and shows a nonmembrane-lytic mechanism and in vivo antiendotoxin and antimicrobial activities. This paradigm of design of antimicrobial peptide with clusters of hydrophobic and hydrophilic residues and high hydrophobic moment but low secondary structure could be attempted further.

Understanding variation in chronic disease outcomes.

We propose an explanation for variation in disease outcomes based on patient adaptation to the conditions of chronic disease. We develop a model of patient adaptation using the example of Type 2 diabetes mellitus and assumptions about the process entailed in transforming self-care behaviors of compliance with treatment, compliance with glucose monitoring, and patient's knowledge seeking behavior into health outcomes of glycemic control and patient satisfaction. Using data from 609 adults with diagnosed Type 2 diabetes we develop an efficiency (fitness) frontier in order to identify best practice (maximally adapted) patients and forms (archetypes) of patient inefficiency. Outcomes of frontier patients are partitioned by categories of returns to scale. Outcomes for off-frontier patients are associated with disease severity and patient archetype. The model implicates strategies for improved health outcomes based on fitness and self-care behaviors.