Thalidomide-induced sinus bradycardia in Crohn's disease: case report and literature review

Severe postural hypotension and sinus bradycardia with thalidomide in patients with erythema nodosum leprosum

Two men in their 60s and 40s were diagnosed with erythema nodosum leprosum based on the development of recurrent painful ulcers and nodules, respectively, for the previous 6 months. Thalidomide 100 mg four times a day, along with MB-MDT, was started in both patients. Both patients experienced severe dizziness on rising from a seated posture soon after initiation of thalidomide and a decrease in blood pressure and heart rate. Cardiovascular/neurology examination and routine blood investigations were normal. An autonomic nervous system assessment indicated bradycardia, postural hypotension and decreased cardiac autonomic function. The dosage of thalidomide was then gradually reduced over 4-5 days to 100 mg/day following a suspicion that thalidomide was the cause of postural hypotension. The dizziness subsided, and blood pressure and heart rate returned to normal.We concluded that thalidomide was the culprit behind bradycardia and dose- dependent postural hypotension.

In silico study of HASDI (high-affinity selective DNA intercalator) as a new agent capable of highly selective recognition of the DNA sequence

Cancer as an acquired genetic disease is based on changes both in the genome itself and in transcription processes. Accordingly, it is at the DNA level that it makes sense to search for and design agents capable of effective and selective anticancer action. In this study, we used an iterative approach based on a molecular dynamics simulation to design a highly selective DNA-intercalating agent called HASDI. To confirm its selective affinity to DNA, we conducted two simulation experiments: HASDI in a complex with a DNA fragment of the EBNA1 gene (it targets 16 nucleotide pairs of this gene) and HASDI in a complex with a random DNA fragment of the KCNH2 gene. The molecular dynamics simulation was carried out in the GROMACS 2019 package. The binding energy was calculated by gmx_MMPBSA 1.5.2. The further analysis was performed using the built-in utilities of GROMACS, gmx_MMPBSA and also XMGRACE and Pymol 1.8. As a result, we determined that the EBNA1-50nt/HASDI complex was stable throughout the whole simulation trajectory. HASDI, due to the presence of a linker modified depending on a specific pair of nitrogenous bases, formed an average of 32 hydrogen bonds with a sequence of 16 nucleotide pairs. Phenazine rings were stably intercalated every 2 base pairs. The root-mean-square deviation of HASDI in such a complex fluctuated around the value of 6.5 Å and had no tendency to increase. The calculated value of the binding free energy was - 235.3 ± 7.77 kcal/mol. The KCNH2-50nt/HASDI complex, as an example of the intercalation of the designed structure into a random part of the human genome, maintained the stability of its position at a level comparable to the EBNA1-50nt/HASDI complex. The phenazine rings were constantly intercalated in their original positions, and the root-mean-square deviation fluctuated around one value, although it had a tendency to chaotic changes. At the same time, this complex was characterized by 17-19 hydrogen bonds, on average, and the binding free energy was - 193.47 ± 14.09 kcal/mol. Moreover, the DNA duplex had local single-nucleotide melting in the region of the 4th linker. According to a significant decrease in the number of hydrogen bonds, a decrease in energy gain, as well as a decrease in the stability of the DNA duplex characteristic of the KCNH2-50nt/HASDI complex compared to the target EBNA1-50nt/HASDI complex, the molecule we designed can be considered a potentially selective DNA polyintercalating agent capable of relatively accurate recognition of 16 base pairs.

Thalidomide-induced serious RR interval prolongation (longest interval >5.0 s) in multiple myeloma patient with rectal cancer: A case report

Primary secondary tumor increased recently with the use of immunomodulatory drugs in patients with multiple myeloma (MM). However, MM with prior diagnosis of primary secondary tumor is relatively rare. In this study, we reported an MM patient with prior diagnosis of rectal cancer. In brief, an 85-year-old man was first diagnosed with rectal cancer. Given the age, heart failure and small-cell hypochromic anemia (hemoglobin level: 54 g/L), rectal cancer resection was not advised and symptomatic treatments were performed (including sufficient iron supplementation). Eight months later, the patient was diagnosed with MM due to worsening anemia. Anemia and heart failure were corrected after three cycles of treatment with thalidomide, dexamethasone and capecitabine. Radical resection of rectal carcinoma (Hartmann) was finally performed due to acute abdominal distension. Meanwhile, RR interval prolongation (longest interval >5.0 s) and atrial fibrillation occurred in the fifth cycle treatment. One month after discontinuation of thalidomide, RR interval returned to normal range, while atrial fibrillation developed into persistent atrial fibrillation.