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.

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.

Anesthetic management for resection of a giant emphysematous bulla: a case report.

Anesthetic management for patients with a giant emphysematous bulla (GEB) is challenging. This case report describes a patient who developed 95% pulmonary compression by a GEB. A 14-Ga indwelling catheter was placed in the GEB before surgery to allow for slow re-expansion of the collapsed lung tissue. This prevented rupture of the GEB during anesthesia. Additionally, positive-pressure ventilation was performed to reduce the risk of re-expansion pulmonary edema. This respiratory management strategy may be beneficial for patients with a GEB who develop pulmonary dysfunction during thoracic surgery.

A novel cold-adapted and highly salt-tolerant esterase from Alkalibacterium sp. SL3 from the sediment of a soda lake.

A novel esterase gene (estSL3) was cloned from the Alkalibacterium sp. SL3, which was isolated from the sediment of soda lake Dabusu. The 636-bp full-length gene encodes a polypeptide of 211 amino acid residues that is closely related with putative GDSL family lipases from Alkalibacterium and Enterococcus. The gene was successfully expressed in E. coli, and the recombinant protein (rEstSL3) was purified to electrophoretic homogeneity and characterized. rEstSL3 exhibited the highest activity towards pNP-acetate and had no activity towards pNP-esters with acyl chains longer than C8. The enzyme was highly cold-adapted, showing an apparent temperature optimum of 30 °C and remaining approximately 70% of the activity at 0 °C. It was active and stable over the pH range from 7 to 10, and highly salt-tolerant up to 5 M NaCl. Moreover, rEstSL3 was strongly resistant to most tested metal ions, chemical reagents, detergents and organic solvents. Amino acid composition analysis indicated that EstSL3 had fewer proline residues, hydrogen bonds and salt bridges than mesophilic and thermophilic counterparts, but more acidic amino acids and less hydrophobic amino acids when compared with other salt-tolerant esterases. The cold active, salt-tolerant and chemical-resistant properties make it a promising enzyme for basic research and industrial applications.

Prediction of effect-site concentration of sufentanil by dose-response target controlled infusion of sufentanil and propofol for analgesic and sedation maintenance in burn dressing changes.

This study was to investigate the feasibility and efficiency of by target-controlled infusion (TCI) for analgesia and sedation during burn dressing change, and to predict the effect-site concentration of sufentanil. Eighty burn patients were randomly and evenly divided into four groups according to target sufentanil effect-site concentration (0.2, 0.3, 0.4 and 0.5 ng/ml). The sufentanil-propofol TCI was carried out during dressing changes. The effect-site concentration of propofol was maintained at 1.2 µg/ml. The dose-response relationships of sufentanil for providing adequate analgesia were evaluated by visual analog scales and Ramsay sedation scores. The effect-site concentration of sufentanil was calculated by Probit regression analysis. Incidence of respiratory depression, doctors and patients' satisfaction and adverse events were assessed. The EC50 and EC95 of sufentanil to maintain anesthesia for uncovering the inner layer dressings during TCI were 0.278 ng/ml (95% CI 0.231-0.318 ng/ml) and 0.394 ng/ml (95% CI 0.366-0.530 ng/ml), respectively, while the EC50 and EC95 of sufentanil to maintain anesthesia for wound management were 0.349 ng/ml (95% CI 0.299-0.366 ng/ml) and 0.465 ng/ml (95% CI 0.430-0.563 ng/ml), respectively. Doctors and patients' satisfaction were significantly higher in the 0.4 and 0.5 ng/ml groups than the 0.2 ng/ml group. One and three patients had respiratory depression in the 0.4 and 0.5 ng/ml groups, respectively. No adverse events occurred after operations. In conclusion, low dose sufentanil-propofol TCI for anesthesia and sedation maintenance in burn dressing changes is feasible and effective, and wound management requires higher effect-site concentrations of sufentanil than disclosing inner layer dressings.