Hypertonic saline and pentoxifylline enhance survival, reducing apoptosis and oxidative stress in a rat model of strangulated closed loop small bowel obstruction

The effects and molecular mechanism of heat stress on spermatogenesis and the mitigation measures

Under normal conditions, to achieve optimal spermatogenesis, the temperature of the testes should be 2-6 °C lower than body temperature. Cryptorchidism is one of the common pathogenic factors of male infertility. The increase of testicular temperature in male cryptorchidism patients leads to the disorder of body regulation and balance, induces the oxidative stress response of germ cells, destroys the integrity of sperm DNA, yields morphologically abnormal sperm, and leads to excessive apoptosis of germ cells. These physiological changes in the body can reduce sperm fertility and lead to male infertility. This paper describes the factors causing testicular heat stress, including lifestyle and behavioral factors, occupational and environmental factors (external factors), and clinical factors caused by pathological conditions (internal factors). Studies have shown that wearing tight pants or an inappropriate posture when sitting for a long time in daily life, and an increase in ambient temperature caused by different seasons or in different areas, can cause an increase in testicular temperature, induces testicular oxidative stress response, and reduce male fertility. The occurrence of cryptorchidism causes pathological changes within the testis and sperm, such as increased germ cell apoptosis, DNA damage in sperm cells, changes in gene expression, increase in chromosome aneuploidy, and changes in Na⁺/K⁺-ATPase activity, etc. At the end of the article, we list some substances that can relieve oxidative stress in tissues, such as trigonelline, melatonin, R. apetalus, and angelica powder. These substances can protect testicular tissue and relieve the damage caused by excessive oxidative stress.

Structural and quantitative alterations of gut microbiota in experimental small bowel obstruction

OBJECTIVE

To investigate structural and quantitative alterations of gut microbiota in an experimental model of small bowel obstruction.

METHOD

A rat model of small bowel obstruction was established by using a polyvinyl chloride ring surgically placed surrounding the terminal ileum. The alterations of gut microbiota were studied after intestinal obstruction. Intraluminal fecal samples proximal to the obstruction were collected at different time points (24, 48 and 72 hours after obstruction) and analyzed by 16s rDNA high-throughput sequencing technology and quantitative PCR (qPCR) for target bacterial groups. Furthermore, intestinal claudin-1 mRNA expression was examined by real-time polymerase chain reaction analysis, and serum sIgA, IFABP and TFF3 levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Small bowel obstruction led to significant bacterial overgrowth and profound alterations in gut microbiota composition and diversity. At the phylum level, the 16S rDNA sequences showed a marked decrease in the relative abundance of Firmicutes and increased abundance of Proteobacteria, Verrucomicrobia and Bacteroidetes. The qPCR analysis showed the absolute quantity of total bacteria increased significantly within 24 hours but did not change distinctly from 24 to 72 hours. Further indicators of intestinal mucosa damage and were observed as claudin-1 gene expression, sIgA and TFF3 levels decreased and IFABP level increased with prolonged obstruction.

CONCLUSION

Small bowel obstruction can cause significant structural and quantitative alterations of gut microbiota and induce disruption of gut mucosa barrier.

TUNEL Assay: A Powerful Tool for Kidney Injury Evaluation

Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay is a long-established assay used to detect cell death-associated DNA fragmentation (3'-OH DNA termini) by endonucleases. Because these enzymes are particularly active in the kidney, TUNEL is widely used to identify and quantify DNA fragmentation and cell death in cultured kidney cells and animal and human kidneys resulting from toxic or hypoxic injury. The early characterization of TUNEL as an apoptotic assay has led to numerous misinterpretations of the mechanisms of kidney cell injury. Nevertheless, TUNEL is becoming increasingly popular for kidney injury assessment because it can be used universally in cultured and tissue cells and for all mechanisms of cell death. Furthermore, it is sensitive, accurate, quantitative, easily linked to particular cells or tissue compartments, and can be combined with immunohistochemistry to allow reliable identification of cell types or likely mechanisms of cell death. Traditionally, TUNEL analysis has been limited to the presence or absence of a TUNEL signal. However, additional information on the mechanism of cell death can be obtained from the analysis of TUNEL patterns.