Severe ischemia after radial artery catheterization: A literature review of published cases.

INTRODUCTION: Severe ischemia is a rare complication of radial artery catheterization (RAC). This study aims to summarize risk factors of RAC-elicited severe hand ischemia, preventive, and therapeutic management. METHODS: Literature search was conducted in eight electronic English and Chinese databases to identify relevant published cases. Data of interest was extracted and analyzed. RESULTS: Database search identified 28 articles reporting cases of 57 patients developing hand ischemia following RAC. Patients aged between 1 day and 88 years. The indications for RAC included surgery, shock, cardiac arrest, and Neonatal Intensive Care Unit (NICU) admission. Identified risk factors included pre-existing vascular diseases, hypotension, arterial anatomical abnormality or small diameter, vasoconstrictors, and catheter-related problems. Totally, 18 patients complained pain; 32 developed discoloration; 19 pulselessness; 3 paresthesia; 13 swolleness and 19 coldness. Eventually, 30 patients recovered well, but 20 patients unfortunately underwent digital amputation and three patients deceased due to non-RAC-related causes. CONCLUSION: Severe hand ischemia following RAC is a rare complication, with the reported incidence of approximately 0.09%. There is no definite predictor for RAC-related hand ischemia, but patients with risk factors are prone to the occurrence of hand ischemia. It's vital to initiate early recognition and proactive strategies for a best practice RAC insertion.

Turgor regulation defect 1 proteins play a conserved role in pollen tube reproductive innovation of the angiosperms.

Sexual reproduction in angiosperms is siphonogamous, and the interaction between pollen tube and pistil is critical for successful fertilization. Our previous study demonstrated that mutation of the Arabidopsis turgor regulation defect 1 (TOD1) gene leads to reduced male fertility, a result of retarded pollen tube growth in the pistil. TOD1 encodes a Golgi-localized alkaline ceramidase, a key enzyme for the production of sphingosine-1-phosphate (S1P), which is involved in the regulation of turgor pressure in plant cells. However, whether TOD1s play a conserved role in the innovation of siphonogamy is largely unknown. In this study, we provide evidence that OsTOD1, which is similar to AtTOD1, is also preferentially expressed in rice pollen grains and pollen tubes. OsTOD1 knockout results in reduced pollen tube growth potential in rice pistil. Both the OsTOD1 genomic sequence with its own promoter and the coding sequence under the AtTOD1 promoter can partially rescue the attod1 mutant phenotype. Furthermore, TOD1s from other angiosperm species can partially rescue the attod1 mutant phenotype, while TOD1s from gymnosperm species are not able to complement the attod1 mutant phenotype. Our data suggest that TOD1 acts conservatively in angiosperms, and this opens up an opportunity to dissect the role of sphingolipids in pollen tube growth in angiosperms.

The Long Journey of Pollen Tube in the Pistil.

In non-cleistogamous plants, the male gametophyte, the pollen grain is immotile and exploits various agents, such as pollinators, wind, and even water, to arrive to a receptive stigma. The complex process of pollination involves a tubular structure, i.e., the pollen tube, which delivers the two sperm cells to the female gametophyte to enable double fertilization. The pollen tube has to penetrate the stigma, grow in the style tissues, pass through the septum, grow along the funiculus, and navigate to the micropyle of the ovule. It is a long journey for the pollen tube and its two sperm cells before they meet the female gametophyte, and it requires very accurate regulation to perform successful fertilization. In this review, we update the knowledge of molecular dialogues of pollen-pistil interaction, especially the progress of pollen tube activation and guidance, and give perspectives for future research.