Inactivation of cell-free HIV-1 by designing potent peptides based on mutations in the CD4 binding site

Human immunodeficiency virus type 1 (HIV-1) is a major global health problem, with over 38 million people infected worldwide. Current anti-HIV-1 drugs are limited in their ability to prevent the virus from replicating inside host cells, making them less effective as preventive measures. In contrast, viral inhibitors that inactivate the virus before it can bind to a host cell have great potential as drugs. In this study, we aimed to design mutant peptides that could block the interaction between gp120 and the CD4 receptor on host cells, thus preventing HIV-1 infection. We designed a 20-amino-acid peptide that mimicked the amino acids of the CD4 binding site and docked it to gp120. Molecular dynamics simulations were performed to calculate the energy of MMPBSA (Poisson-Boltzmann Surface Area) for each residue of the peptide, and unfavorable energy residues were identified as potential mutation points. Using MAESTRO (Multi AgEnt STability pRedictiOn), we measured ΔΔG (change in the change in Gibbs free energy) for mutations and generated a library of 240 mutated peptides using OSPREY software. The peptides were then screened for allergenicity and binding affinity. Finally, molecular dynamics simulations (via GROMACS 2020.2) and control docking (via HADDOCK 2.4) were used to evaluate the ability of four selected peptides to inhibit HIV-1 infection. Three peptides, P3 (AHRQIRQWFLTRGPNRSLWQ), P4 (VHRQIRQWFLTRGPNRSLWQ), and P9 (AHRQIRQMFLTRGPNRSLWQ), showed practical and potential as HIV inhibitors, based on their binding affinity and ability to inhibit infection. These peptides have the ability to inactivate the virus before it can bind to a host cell, thus representing a promising approach to HIV-1 prevention. Our findings suggest that mutant peptides designed to block the interaction between gp120 and the CD4 receptor have potential as HIV-1 inhibitors. These peptides could be used as preventive measures against HIV-1 transmission, and further research is needed to evaluate their safety and efficacy in clinical settings.

The functional impact of home-based self-rehabilitation following arthroscopic meniscus root repair

BACKGROUND

Corona virus infectious pandemic makes outdoors rehabilitation a potential hazard. Patient education to perform simple home-based exercises seems to be an interesting and sometimes a mandatory option. This study provides a comparison between the conventional and home-based virtual rehabilitation after surgical repair of medial meniscus root tears.

METHODS

In this prospective study, all patients who underwent medial meniscus posterior root repair with a modified trans-tibial pull-out technique from March 2019 to March 2021 were evaluated. Those who underwent surgery after December 2019 were trained to perform self-rehabilitation. The rest had undergone outdoors specialized rehabilitation according to a unified protocol and these were used as a historical control group. All patients were followed up for a minimum of 2 year after surgery. Final Lysholm scores were utilized to compare functional outcomes after considering the effect of age, body mass index and time from surgery by multivariate linear regression analysis.

RESULTS

Forty-three consecutive patients with medial meniscal root tears were studied. Thirty-nine (90.7%) were women and 4 (9.3%) were men. The mean age of participants was 53.2 ± 8.1 years. The total Lysholm knee score, and all its items were significantly improved in both groups at a two-year follow-up (p < 0.05), except the "Using cane or crutches" item (p = 0.065). Nevertheless, the final Lysholm knee score improvement was higher in patients who performed outdoors specialized rehabilitation and in patients with shorter time-to-surgery.

CONCLUSION

Regardless of age and gender, home-based rehabilitation after meniscal root repair with the modified trans-tibial pull-out technique improved the patients' function at a two-year follow-up. Nonetheless, this effect was still significantly lower than that of the outdoors specialized rehabilitation. Future work is required to clarify basic protocols for home-based tele-rehabilitation programs and determine clinical, radiological and functional results.

LEVEL OF EVIDENCE

Level IV, therapeutic, historically controlled study.

Acute effect of intermittent and continuous aerobic exercise on release of cardiac troponin T in sedentary men

BACKGROUND

Studies have shown that acute exercise can increase serum concentrations of cardiac biomarkers, including cardiac troponin T (cTnT). We investigated the acute effects of intermittent (IE) and continuous (CE) exercise at the same cardiac workload on myocardial necrosis biomarkers in sedentary men.

METHODS

Eleven sedentary healthy men aged 22.3±1.9years completed the study. The subjects were divided into two groups and performed, in random order, IE (intensity alternating between 50% (2min) and 80% (1min) HRreserve) or CE (60% HRreserve). The study was designed as a single-blinded randomised crossover trial performed on two distinct experimental days separated by a 1-week washout period. Each session consisted of 40min of aerobic exercise, either IE or CE, on a treadmill. Blood samples were taken before (PRE), immediately after (POST) and 1h after (POST-1) each exercise session.

RESULTS

hs-cTnT significantly increased immediately after exercise in both protocols and remained elevated at POST-1 (P<0.05). There was no significant difference between POST and POST-1 values(P>0.05). Neither CE nor IE caused any significant change in CK-MB (P>0.05). The results also showed that HR and RPP increased significantly following both exercise protocols (P=0.001).

CONCLUSIONS

In summary, both CE and IE results in increased serum concentrations of hs-cTnT in sedentary men. However, this increase does not seem to be caused by the irreversible death of cardiomyocytes. CE resulted in a greater hs-cTnT concentration than IE.

Imerslund-Grasbeck syndrome in a 5-year-old Iranian boy

Imerslund-Grasbeck syndrome (IGS) is a rare syndrome characterized by clinical symptoms and signs of Vitamin B₁₂ deficiency and proteinuria. Our patient was a 5-year-old boy with pallor, lack of appetite, and low weight gain. Laboratory studies showed severe macrocytic anemia, normal reticulocyte count, negative direct coombs test, normal osmotic fragility, and autohemolysis test. He has had intermittent proteinuria since 3 years ago despite normal creatinine level and absence of hematuria or hypertension. Finally, based on low level of serum B₁₂ vitamin and normal folate level accompanied by asymptomatic proteinuria, the diagnosis of IGS was made. Furthermore, his sister has had laboratory abnormalities without any symptoms. IGS responded to B₁₂ replacement therapy dramatically but intermittent proteinuria persisted even after appropriate therapy.

Canalicular stenosis secondary to weekly docetaxel: a potentially preventable side effect

BACKGROUND

The purpose of this study was to describe canalicular stenosis as a mechanism for epiphora (excessive tearing) secondary to weekly docetaxel.

PATIENTS AND METHODS

Fourteen patients with metastatic breast cancer who developed epiphora during weekly docetaxel therapy underwent an ophthalmologic examination, and probing and irrigation of the nasolacrimal ducts. The total duration of docetaxel therapy, the duration of treatment at the time of onset of epiphora, the number of infusions, the cumulative dose of docetaxel and the severity of canalicular stenosis were recorded.

RESULTS

All 14 patients had anatomic narrowing of the canaliculi as the underlying mechanism for epiphora. Bicanalicular silicone intubation or dacryocystorhinostomy (DCR) was recommended for all 14 patients. Eleven patients underwent surgery and experienced resolution of their symptoms. The three patients who declined surgery continue to have epiphora at the time of this report.

CONCLUSIONS

Canalicular stenosis is an underlying mechanism for epiphora in patients receiving weekly docetaxel. Bicanalicular silicone intubation should be considered early in the course of weekly docetaxel therapy to prevent complete closure of the canaliculi. Once complete or near complete stenosis of the canaliculi occurs, DCR with a permanent pyrex glass tube placement may become necessary to overcome the blockage of tear outflow.

Surgical treatment of canalicular stenosis in patients receiving docetaxel weekly

OBJECTIVE

To describe the surgical treatment and outcomes in patients with metastatic breast cancer and canalicular stenosis caused by weekly treatment with docetaxel.

METHODS

This case series included 10 patients with persistent epiphora due to weekly docetaxel treatment, who were evaluated by probing and irrigation of the tear drainage apparatus and were found to have significant canalicular stenosis. The severity of canalicular stenosis was graded clinically. Each patient underwent bicanalicular silicone intubation or dacryocystorhinostomy (DCR) with placement of either a silicone tube (canaliculo DCR) or a pyrex glass tube (conjunctivo DCR).

RESULTS

Seven patients (12 eyes) underwent bicanalicular silicone intubation. Three patients (5 eyes) required canaliculo DCR with the placement of a silicone tube. In 2 patients (3 eyes), the degree of canalicular stenosis was severe enough to require conjunctivo DCR with the placement of a pyrex glass tube. All 10 patients had complete resolution of epiphora immediately after surgery. Four patients continued to receive docetaxel after surgery. In patients who underwent bicanalicular silicone intubation, the silicone stent was kept in place for the duration of docetaxel therapy. There were no surgical or anesthesia-related complications. At a mean follow-up time of 9 months after surgery, all but 1 patient (1 eye) remained asymptomatic. The interval between initiation of docetaxel therapy and surgery was significantly higher in patients who required DCR compared with those who had silicone intubation. The mean cumulative dose of docetaxel at the time of surgery was higher in patients who required DCR than in patients who had silicone intubation, but this difference was not statistically significant.

CONCLUSIONS

Canalicular stenosis secondary to weekly treatment with docetaxel should be treated with bicanalicular silicone intubation early in the course of docetaxel therapy. Failure to treat this adverse effect early may likely lead to severe and irreversible canalicular stenosis, which may necessitate conjunctivo DCR with the placement of a permanent pyrex glass tube.

Late choroidal metastasis secondary to papillary thyroid carcinoma

PURPOSE

To report a case of late choroidal metastasis from papillary thyroid carcinoma.

METHODS

Interventional case report. A 43-year-old woman who had been treated for papillary thyroid carcinoma 30 years earlier presented for evaluation of vision loss in the left eye. Eight weeks before this presentation, an ophthalmologist had diagnosed a metastatic uveal mass in the left eye of the patient. The clinical record was retrospectively reviewed. Ocular sonography was performed to confirm the diagnosis of choroidal metastasis.

RESULTS

The choroidal mass had the typical characteristics of a metastatic lesion. The patient was treated with a combination of brachytherapy and chemotherapy.

CONCLUSION

Papillary thyroid carcinoma can metastasize to the choroid many years after the initial diagnosis.

Canalicular stenosis secondary to docetaxel (taxotere): a newly recognized side effect

OBJECTIVE

To report a newly recognized side effect of a commonly used antineoplastic agent, docetaxel, in three patients with metastatic breast cancer.

DESIGN

Observational case reports.

PARTICIPANTS

Three patients with metastatic breast cancer who received weekly docetaxel chemotherapy.

MAIN OUTCOME MEASURES

Occurrence of epiphora and severity of punctal and canalicular fibrosis secondary to docetaxel.

RESULTS

In three patients receiving weekly docetaxel, canalicular stenosis and resultant epiphora developed shortly after start of their treatment. Discontinuation of drug several months after initiation of therapy did not lead to resolution of symptoms in two of the three patients.

CONCLUSIONS

Epiphora is a newly recognized side effect of docetaxel and may occur more frequently with weekly cycles of this drug. The mechanism for epiphora seems to be punctal and canalicular stenosis. This side effect, in advanced cases, is not reversible with discontinuation of the drug. Patients being administered weekly cycles of docetaxel should be screened for epiphora and canalicular stenosis, and treatment in the form of silicone intubation or punctoplasty should be considered in early stages to prevent the need for conjunctivodacryocystorhinostomy.