Primary intramedullary melanocytoma presenting with lower limbs, defecation, and erectile dysfunction: A case report and review of the literature.

BACKGROUND: Primary intramedullary melanocytoma is an exceedingly rare type of primary melanocytic tumor in the central nervous system. Unfortunately, primary intramedullary melanocytoma lacks specificity in clinical symptoms and imaging features and there is currently no standard strategy for diagnosis or treatment. CASE SUMMARY: A 52-year-old male patient suffered from weakness and numbness involving the bilateral lower limbs for 18 mo, and defecation and erectile dysfunction for 6 mo. Furthermore, these symptoms started to worsen for the last 3 mo. Preoperative magnetic resonance imaging (MRI) revealed an intramedullary tumor located at the T9-T10 level. In subsequently surgery, the maximal safe resection extent approached to 98%. The lesion was confirmed to be melanocytoma by pathological examination. In addition, the possibility of original melanocytoma outside the spinal cord was excluded after the examination of the whole body. Therefore, a diagnosis of primary intramedullary melanocytoma was established. The patient refused to accept radiotherapy or Gamma Knife, but MRI examination on July 28, 2020 showed no sign of development. In addition, on April 10, 2021, the recent review showed that the disorder of defecation and lower limbs improved further but erectile dysfunction benefited a little from the surgery. CONCLUSION: After diagnosing intramedullary melanocytoma by postoperative pathology, the inspection of the whole body contributed to excluding the possibility of metastasis from other regions and further suggested a diagnosis of primary intramedullary melanocytoma. Complete resection, adjuvant radiation, and regular review are critical. In addition, maximal safe resection also benefits prognosis while the tumor is difficult to be resected totally.

Chemical synthesis, crystal structure, versatile evaluation of their biological activities and molecular simulations of novel pyrithiobac derivatives.

Since pyrithiobac (PTB) is a successful commercial herbicide with very low toxicity against mammals, it is worth exploring its derivatives for an extensive study. Herein, a total of 35 novel compounds were chemically synthesized and single crystal of 6-6 was obtained to confirm the molecular structure of this family of compounds. The novel PTB derivatives were fully evaluated against various biological platforms. From the bioassay results, the best AHAS inhibitor 6-22 displayed weaker herbicidal activity but stronger anti-Candida activity than PTB did. For plant pathogenic fungi, 6-26 showed excellent activity at 50 mg/L dosage. Preliminary insecticidal activity and antiviral activity were also observed for some title compounds. Strikingly, 6-5 exhibited a promising inhibitory activity against SARS-CoV Mpro with IC50 of 4.471 µM and a low cellular cytotoxicity against mammalian 293 T cells. Based on the results of molecular modeling, HOMO-1 was considered to be a factor that affects AHAS inhibition and a possible binding mode of 6-5 with SARS-CoV Mpro was predicted. This is the first time that PTB derivatives have been studied as biological agents other than herbicides. The present research hence has suggested that more attentions should be paid to compounds belonging to this family to develop novel agrochemicals or medicines.

[Study on quantitative mechanism and the interference of the UV spectrum of HABS reduced by ß-Cyclodextrin].

A novel ultraviolet absorption spectrometry method was developed for the quantitative determination of HABS by adding ß-cyclodextrin with the molar ratio of 1:1 in strong interference aqueous solution. The results indicated that the effect of several common interfering flooding agents (SAS, OP-10, HPAM) on the determination of HABS could be greatly reduced in ß- cyclodextrin aqueous solution. Thus, the determination errors of the determined HABS were less than 2.0% under strong inter- ference, and the detection limit (S/N==3) of the method could be also as high was 8.3-9.1 x 10(-4) mg · L(-1). Various characterization results including 1H-NMR, TG-DSC and FTIR showed the interaction between ß-cyclodextrin and HABS. The results of H-NMR analysis showed that HABS molecule could enter into the interior of the cavity of ß-cyclodextrin molecule. TG-DSC analysis exhibited that the stable inclusion of ß-cyclodextrin and HABS could be automatically formed. The interactions between the functional groups of ß-cyclodextrin and HABS were showed by FTIR analysis, which also exhibited that the stable inclusion could be formed by HABS entering from the narrow or the broad mouth of the ß-cyclodextrin. The interference of the UV spectrum of HABS could be reduced by ß-cyclodextrin since the interaction between ß-cyclodextrin due to the interaction between ß-cyclodextrin and HABS in the inclusion complex.

[Study on the enhanced spectrum quantitative analysis of SDBS induced by beta-cyclodextrin].

A novel enhanced ultraviolet absorption spectrometry method was developed for the quantitative analysis of SDBS induced by beta-cyclodextrin(beta-CD) with strong interferences. The ultraviolet absorption spectra of SDBS indicated that the presence of beta-CD could result in the enhancement of absorption intensities of SDBS. A good linearity was obtained between the UV-absorption intensity of the system and the concentration of SDBS. The results indicated that the determination precision and the determination ranges of SDBS could be greatly improved by beta-CD. The effect of several common interfering substances (SDS, OP-10, HPAM) on the determination of SDBS could be significantly reduced in beta-CD aqueous solution. Therefore, the maximum errors of the determined SDBS were less than 2.0% under multifactor interferences, and the precision of the method was also as high as 10(-2) - 10(-3) mg x L(-1). The stable inclusion of beta-CD and SDBS could be automatically formed in water with molar ratio of 1 : 1. The stability constant of the inclusion, K(a), was 87 and the standard Gibbs function of molar reaction, delta(gamma)G(m)(see symbol) (298 K), was -11.064 kJ x mol(-1). FTIR analysis exhibited that SDBS could be induced by beta-CD since the phenyl group in SDBS molecule could exist stably in the cavity of beta-CD and form the inclusion.

Spectroscopic and molecular modeling studies on the interaction between a fluorine-containing triazole derivative and human serum albumin.

The interaction between 4-(4-fluorobenzylideneamino)-5-propyl-4H-1,2,4-triazole-3-thiol (FBTZ) and human serum albumin (HSA) under simulative physiological conditions was investigated by fluorescence, UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular modeling method. Fluorescence spectroscopic data showed that the fluorescence quenching of HSA was a result of the formation of FBTZ-HSA complex. According to the modified Stern-Volmer equation, the effective quenching constants (K (a)) of FBTZ to HSA were obtained at three different temperatures. The enthalpy change (ΔH) and entropy change (ΔS) were calculated on the basis of van't Hoff equation, and the results showed that hydrogen-bonding and van der Waals forces were the dominant intermolecular forces to stabilize the complex. Site marker competitive replacement experiments demonstrated that the binding of FBTZ to HSA primarily took place in sub-domain IIA (Sudlow's site I). The binding distance (r) between FBTZ and the tryptophan residue of HSA was estimated according to the theory of fluorescence resonance energy transfer. The conformational investigation showed that the presence of FBTZ induced some changes of secondary structure of HSA. Molecular modeling study further confirmed the binding mode obtained by experimental study.