Structure and hemolytic activity relationships of triterpenoid saponins and sapogenins

We evaluated the hemolytic activity of 41 commercially available triterpenoid saponins and sapogenins derived from three types of structural skeletons. Structure–activity relationships were established by comparing the structural characteristics of both the aglycone and sugar moieties among the tested compounds. The majority of oleanane-type sapogenins had stronger hemolytic effects than those of the ursane and dammarane types. The presence of polar regions on sapogenins, such as a carboxyl (COOH) at position 28, an α-hydroxyl (α-OH) at position 16, and/or a β-hydroxyl (β-OH) at position 2, significantly enhanced hemolysis. Meanwhile, the introduction of an α-OH at position 2 or a methyl hydroxyl (CH₂OH) at positions 23 or 24 was closely associated with reduced activity. Our findings suggest that not only the complexity of sugar moieties but also the types and stereochemical configurations of functional groups at different positions, as well as the skeleton types, are important structural features affecting hemolytic potential. Our results provide a baseline in terms of the toxicity of saponins and sapogenins to erythrocytes, which holds promise for drug development.     

Blood-based immunoassay of tau proteins for early diagnosis of Alzheimer's disease using surface plasmon resonance fiber sensors

We present the immunoassay of tau proteins (total tau and phosphorylated tau) in human sera using surface plasmon resonance (SPR) fiber sensors. This assay aimed at harvesting the advantages of using both SPR fiber sensors and a blood-based assay to demonstrate label-free point-of-care-testing (POCT) patient-friendly assay in a compact format for the early diagnosis of Alzheimer''s disease (AD). For conducting the assay, we used human sera of 40 subjects divided into halves, which were grouped into AD patients and control groups according to a number of neuropsychological tests. We found that on an average, the concentrations of both total tau and phosphorylated tau proteins (all known to be higher in cerebrospinal fluid (CSF) and the brain) turned out to be higher in human sera of AD patients than in controls. The limits of detection of total tau and phosphorylated tau proteins were 2.4 pg mL⁻¹ and 1.6 pg mL⁻¹, respectively. In particular, it was found that the AD group exhibited average concentration of total tau proteins 6-fold higher than the control group, while concentration of phosphorylated tau proteins was 3-fold higher than that of the control. We can attribute this inhomogeneity between both types of tau proteins (in terms of increase of control-to-AD in average concentration) to un-phosphorylated tau proteins being more likely to be produced in blood than phosphorylated tau proteins, which possibly is one of the potential key elements playing an important role in AD progress.

Blood-based early diagnosis of Alzheimer''s disease using a plasmonic fiber sensor that detects immunoreaction of tau proteins.     

Three new steroidal saponins from Aspidistra letreae plants and their cytotoxic activities

Three new steroidal saponins, aspiletreins A–C (1–3), together with 2H-chromen-2-one (4), and α-tocopherol (5), were isolated from whole Aspidistra letreae plants collected in Vietnam. Their structures were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR, IR, and HRESIMS, and by comparison with the reported data in the literature. Compounds 1–3 exhibited moderate cytotoxicities against the LU-1, HeLa, MDA-MB-231, HepG2, and MKN-7 human cancer cell lines, with IC₅₀ values ranging from 7.69?±?0.40 to 20.46?±?3.11 µM.

     

Single-Port Laparoscopic Repair of Perforated Duodenal Ulcers

Background

Laparoscopic single-port surgery has widely been introduced for the treatment of various abdominal conditions. But controversies still exist regarding its potential advantages and risks, especially for emergency surgery. The aim of this study was to evaluate the results of a single-port laparoscopic repair using straight laparoscopic instruments for the treatment of perforated duodenal ulcers.

Methods

A prospective consecutive case series was conducted including all patients with a perforated duodenal ulcer who underwent a laparoscopic single-port repair at a single institution from January 2012 to June 2018. The operation was performed through a single port using conventional straight laparoscopic instruments and intra-corporeal knot tying techniques.

Results

Out of 75 patients, simple closure of the perforation without omental patch was accomplished in 96% of cases. Conversion to an open operation was required in one patient (1.3%) due to a posterior duodenal perforation, and additional trocar placement was needed in another patient (1.3%). The mean incision length was 2.0 ± 0.2 cm. The mean operation time was 63.0 ± 26.6 min. Meantime a nasogastric tube remained in place was 2.9 ± 0.8 days. Mean duration of analgesic use was 2.8 ± 0.8 days. The rate of postoperative complications was 2.7%, including two patients with wound infections. There were no instances of intestinal leak or abscess. The postoperative hospital stay was 5.7 ± 1.2 days.

Conclusion

Laparoscopic single-port repair using conventional straight laparoscopic instruments with intra-corporeal knot tying technique was safe and feasible for patients with perforated duodenal ulcers with low risk factors. This method offers results comparable to those expected with the standard multiport laparoscopic approach with the addition of improved cosmetic outcomes.

     

Key Points to Consider When Evaluating Andexxa for Formulary Addition

Neurocritical Care -