[Diagnostic value of rapid exchange test in patients with peritoneal dialysis catheter dysfunction]

A total of 36 patients with suspected peritoneal dialysis (PD) catheter dysfunction in the First Hospital of China Medical University from June 2020 to August 2022 were included, and five patients with normal PD catheter were also included as the control group. There were 22 males and 19 females, and aged (45±21) years. The volume of rapid-phase drainage in the control and dysfunction groups was (2 086±65) and (1 181±637) ml, and the total drainage time was (15.2±1.3) and (38.3±14.9) min, respectively. The volume of rapid-phase drainage in the dysfunction group was reduced and the total drainage time was longer than that in the control group (both P<0.05). Compared with group with PD catheter migration, the duration of new bag instillation was prolonged, the drainage volume in the rapid-phase was reduced, the total drainage duration was prolonged, and the ultrafiltration volume was decreased in the group with PD catheter obstruction (all P<0.05). The rapid exchange test can provide an early preliminary diagnosis of PD catheter dysfunction and identify the type of catheter dysfunction.

Transposable elements and tumor progression

Although the concept that transposable elements (TEs) have the potential to enhance their host genomic evolution is widely accepted, it is still generally assumed that TEs primarily owe their prosperity to replicative advantage because the immediate effects on their hosts are generally harmful. To mitigate deleterious impact, hosts employ a cosuppression strategy to tame these perilous elements. The peculiarity of this strategy, however, is that TEs, as targets of suppression, also serve as primary components of this 'TE immune system'. Based on this view, we propose a possible mechanism whereby TEs are involved in tumor progression.

Different effects of toosendanin on perineurially recorded Ca(2+) currents in mouse and frog motor nerve terminals

By perineurial recording, the effects of toosendanin (TSN), a presynaptic blocker, on nerve terminal calcium currents (I(Ca)) were observed in innervated triangularis sterni of the mouse and cutaneous pectoris of the frog. It was found that TSN blocked the slow component of I(Ca) insensitive to nifedipine and omega-conotoxin-GVIA, and increasing the extracellular Ca(2+) concentration partially antagonized the inhibitory effect in mouse motor nerve terminals. However, in the frog, TSN increased the slow component of I(Ca) and this effect disappeared in the presence of nifedipine in perfusion solution. Based on previous data showing that the slow component of I(Ca) were mediated by different subtypes of calcium channels in mouse and frog motor nerve terminals, we presume that TSN could exercise different effects on various subtypes of calcium channels.

[Studies on the chemical constituents from Tribulus terrestris]

AIM

To investigate the chemical constituents of the fruit of Tribulus terrestris J..

METHODS

Various chromatographic techniques were used to separate the chemical constituents. ESIMS, IR, 1HNMR, 13CNMR and HMBC were used to determine the structures of the isolated constituents.

RESULTS

Two new compounds were isolated from the fruits of Tribulus terrestris J. and were identified as neohecogenin-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (I); neohecogenin-3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (II).

CONCLUSION

Compounds I and II are new steroidal saponins.

Measurement of cylindrical particles with phase Doppler anemometry

Light scattering from cylindrical particles has been described with geometric optics. The feasibility of determining the particle diameter with a planar phase Doppler anemometer has been examined by simulations and experiments. In particular, the influence of particle orientation on measurability and measurement accuracy has been investigated. Some recommendations for realizing a practical-measurement instrument have been presented.