The Scheduling Mode of Anesthesia Nurses Affects Postanesthesia Care Unit Efficiency: A Single-Center Retrospective Study From China.

PURPOSE: Anesthesia nurses play an important postsurgical role during the anesthesia recovery period, which is characterized by a high incidence of complications related to anesthesia and surgery. Strengthening staff allocation and skill management in the postanesthesia care unit (PACU) is therefore particularly important in managing length of stay. We aimed to investigate the effect of two schedule modes for anesthesia nurses on PACU efficiency. DESIGN: A retrospective observational cohort study. METHODS: We conducted a retrospective study in a large tertiary academic medical center. In 2018, the PACU operated with traditional scheduling and the nurse-to-patient ratio was 1.2:1. The PACU implemented intensive scheduling and this ratio was adjusted to 1:1 in 2019 by adjusting the anesthesia nurse allocation scheme. We compared the number of admitted patients, length of PACU stay, the incidence of anesthesia-related complications, and nurse satisfaction with the two modes. FINDINGS: The total number of admitted patients was 10,531 in 2018 and 10,914 in 2019. PACU admitted 401 more patients in 2019 than in 2018, even with two fewer nurses per day. Nevertheless, the median length of PACU stay in 2019 was statistically significantly shorter than in 2018 (29 [22-40] vs 28 [21-39], P < .001], while the incidence of anesthesia-related complications including postoperative pain, nausea and vomiting, hypertension, and shivering were comparable in the 2 years (P > .091). The intensive scheduling implemented in 2019 received more satisfaction from nurses than the traditional scheduling applied in 2018 (P < .01). CONCLUSIONS: The scheduling of anesthesia nurses affects PACU efficiency. The intensive scheduling mode implemented in 2019 resulted in a comparable number of admitted patients, a better quality of care, and higher nurse satisfaction than those under the traditional scheduling mode.

Effect of Clostridium butyricum on the formation of primary choledocholithiasis based on intestinal microbiome and metabolome analysis.

AIMS: To investigate the function and probable mechanism of Clostridium butyricum in the development of choledocholithiasis. METHODS AND RESULTS: The lithogenic diet group and the lithogenic diet + C. butyricum group were used to develop the choledocholithiasis model. During the experiment, C. butyricum suspension was administered to the rats in the lithogenic diet + C. butyricum group. The findings demonstrated that the C. butyricum intervention decreased the Firmicutes/Bacteroidetes ratio in the colon of experimental animals given a lithogenic diet. The relative levels of Desulfovibrio (0.93%) and Streptococcus (0.38%) fell, whereas Lactobacillus (22.36%), Prevotella (14.09%), and bacteria that produce short-chain fatty acids increased. Finally, 68 distinct metabolic products were found based on nontargeted metabonomics, and 42 metabolic pathways associated to the various metabolites were enriched. CONCLUSIONS: We found that C. butyricum decreased the development of choledocholithiasis. It keeps the equilibrium of the rat's gut microbiome intact and lowers the danger of bacterial infections of the gastrointestinal and biliary systems. It is hypothesized that by controlling lipid metabolism, it may also have an impact on the development of cholelithiasis.

LncRNA FALEC increases the proliferation, migration and drug resistance of cholangiocarcinoma through competitive regulation of miR-20a-5p/SHOC2 axis.

BACKGROUND: LncRNA is an important regulatory factor in the human genome. We aim to explore the roles of LncFALEC and miR-20a-5p/SHOC2 axis on the proliferation, migration, and Fluorouracil (5-FU) resistance of cholangiocarcinoma (CCA). METHODS: In this study, the expression of FALEC and miR-20a-5p in CCA tissues and cell lines (HuCCT1, QBC939, and Huh-28) was detected by RT-qPCR. The FALEC in 5-FU-resistant CCA cell lines (QBC939-R, Huh-28-R) was knocked down to evaluate its effects on cell proliferation, migration, invasion, and drug resistance. RESULTS: Our analysis showed that compared with the adjacent non-tumor tissues, FALEC was significantly higher in the CCA tissues and even higher in the samples from 5-FU-resistant patients. Knockdown FALEC increased the sensitivity of 5-FU and decreased migration and invasion of CCA cells. Dual luciferase reporter confirmed that FALEC sponges miR-20a-5p and down-regulated its expression. Moreover, SHOC2 leucine-rich repeat scaffold protein (SHOC2) was the target gene of miR-20a-5p. We found overexpression of FALEC (FALEC-OE) increased resistance of CCA cells to 5-FU significantly, which might contribute to increased SHOC2 expression and activation of the ERK1/2 signaling pathway. CONCLUSIONS: In summary, our study revealed that down-regulation of FALEC could inhibit the proliferation, migration, and invasion of CCA cells in vitro by regulating the miR-20a-5p/SHOC2 axis and participating in 5-FU resistance by mediating the ERK1/2 signaling pathway.

Postoperative Delirium in Neurosurgical Patients: Recent Insights into the Pathogenesis.

Postoperative delirium (POD) is a complication characterized by disturbances in attention, awareness, and cognitive function that occur shortly after surgery or emergence from anesthesia. Since it occurs prevalently in neurosurgical patients and poses great threats to the well-being of patients, much emphasis is placed on POD in neurosurgical units. However, there are intricate theories about its pathogenesis and limited pharmacological interventions for POD. In this study, we review the recent insights into its pathogenesis, mainly based on studies within five years, and the five dominant pathological theories that account for the development of POD, with the intention of furthering our understanding and boosting its clinical management.

Use of a specialty endoscopy online platform for continuing medical education for clinical endoscopists during the COVID-19 pandemic.

BACKGROUND: To explore the use of a digestive endoscopy professional online platform by domestic endoscopists and its application effect on endoscopists' continuing medical education, analyse the related problems of continuing medical education using this method, and propose targeted improvement suggestions. METHODS: Based on the "Doctor's Circle" app, a questionnaire was sent to all members who successfully registered on the Hebei Biliary and Pancreatic Endoscopy Diagnosis and Treatment Alliance online platform. The questionnaire was available for 30 days. The questionnaire survey results were collected and counted for a grouping comparison. RESULTS: By the deadline, 703 completed questionnaires had been received. After the registered doctors joined the platform, 469 (66.7%) experienced a significant influence on their own endoscopic operation ability level, and 354 (50.3%) felt a significant improvement in their ability to diagnose biliary- and pancreatic-related diseases. The application effect of the platform on members' continuing medical education was affirmed by the vast majority of registered doctors. The clinical specialty of registered doctors, the length of time they joined the platform, the length of time they participated in the platform activities each time, and whether they played back course videos after the live broadcast of the course on the platform were the main factors affecting the application effect on continuing medical education (P < 0.05). Registered doctors who benefited significantly from the platform used it for 6-12 months, participated in activities for 1-2 hours each time, and often played back course videos. CONCLUSION: The new model of continuing medical education based on an online platform breaks through the constraints of traditional models and meets the individualized needs of every medical worker to improve their comprehension level. At present, the global outbreak of COVID-19 makes this learning mode increasingly popular among medical workers. We should constantly improve the organization of the content and methods of continuing medical education courses, make the online platform better serve the majority of medical workers, and effectively improve the comprehension levels of clinicians.

MiRNA-196-5p Promotes Proliferation and Migration in Cholangiocarcinoma via HAND1/Wnt/ß-Catenin Signaling Pathway.

Accumulating evidence has indicated the crucial role of microRNA-196 in mediating tumor progression, while its significance in cholangiocarcinoma (CCA) remains unclear. In this study, we provided the first evidence that the expression level of miR-196-5p is elevated in both CCA cell lines and clinic specimen. MiR-196-5p inhibition notably suppressed cell proliferation as well as metastasis in CCA cell line HuCCT1. Furthermore, the interaction between miR-196-5p and its downstream molecule HAND1 was verified. Moreover, a series of rescue assay verified that both HAND1 and ß-catenin silencing could reverse the abnormal elevated cell proliferation and migration brought by miR-196-5p elevation, indicating that HAND1/Wnt/ß-catenin signaling pathway activation is essential for miR-196-5p to exert its roles. In summary, we successfully depict the oncogenic role of miR-196-5p in promoting cell proliferation and migration in CCA via HAND1/Wnt/ß-catenin axis.

Dual-Subpopulation as reciprocal optional external archives for differential evolution.

Differential Evolution (DE) is powerful for global optimization problems. Among DE algorithms, JADE and its variants, whose mutation strategy is DE/current-to-pbest/1 with optional archive, have good performance. A significant feature of the above mutation strategy is that one individual for difference operation comes from the union of the optional external archive and the population. In existing DE algorithms based on the mutation strategy-JADE and its variants, individuals eliminated from the population are send to the archive. In this paper, we propose a scheme for managing the optional external archive. According to our scheme, two subpopulations are maintained in the population. Each of them regards the other as the archive. In experiments, our scheme is applied in JADE and two of its variants-SHADE and L-SHADE. Experimental results show that our scheme can enhance JADE and its variants. Moreover, it can be seen that L-SHADE with our scheme performs significantly better than four DE algorithms, CoBiDE, MPEDE, EDEV, and MLCCDE.

Ageing characteristics of bone indicated by transcriptomic and exosomal proteomic analysis of cortical bone cells.

BACKGROUND: Degenerative changes in the skeleton play an important role in ageing. As the foremost sensors and orchestrators of bone remodelling, osteocytes contribute significantly to the health of the skeleton. Embedded in a mineralized bone matrix, the osteocyte network and the surrounding lacunar canaliculae work together as a functional syncytium-the osteocytic lacunar-canalicular system (OLCS). However, changes in the OLCS during ageing and related mechanisms cannot be fully understood by using traditional histological analysis. METHODS: To link the phenotypes of aged osteocytes and their functional changes during ageing, we analysed the changes in the gene expression profiles of bone cells and the proteomic profiles of OLCS exosomes derived from aged and young cortical bone. RESULTS: Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed genes (DEGs) suggested that a decline in cell energy metabolism and an increased level of the proinflammatory state are major characteristics of bone ageing. Moreover, some DEGs were key regulators of bone mechanical sensation and bone remodelling, which are indicative of reduced bone-specific function with age. Further, the identified proteins in OLCS exosomes showed potential changes in the secretory function bone. Compared with young controls, the decreased functional proteins in aged OLCS exosomes were enriched mainly in GO terms that included regulating bone development and remodelling, cell-matrix adhesion, and cell clearance and homeostasis. Notably, several functions of exosomal proteins of the aged group revealed potential new roles, such as regulating innate and adaptive immunity, wound healing, and angiogenesis and eliminating oxidative stress. CONCLUSION: The information obtained from bone cells and OLCS exosomes will help us discover new features of bone ageing.

Osteoprotegerin-Knockout Mice Developed Early Onset Root Resorption.

INTRODUCTION: Recent studies indicate that the osteoprotegerin (OPG)/RANKL/RANK pathway takes part in root resorption. However, the relationship between OPG and root resorption is vague. The purpose of our study was to investigate the role of OPG in root resorption. METHODS: The first molars of the mandibles of osteoprotegerin-knockout (Opg-KO) mice and wild-type (WT) mice were evaluated by micro-computed tomography, histology, and immunohistochemistry at 4, 6, 26, and 52 weeks. To detect the activity of the osteoclasts, we induced bone marrow macrophages into osteoclast-like cells from Opg-KO mice and wild-type mice in vitro and then compared their osteoclast activities. To evaluate the cementum quality, an osteoclast-cementum co-culture model was established in vitro. RESULTS: In Opg-KO mice, root resorption began at the age of 4 weeks. At 6 weeks the cementum damage extended to the coronal and apical regions, and at 52 weeks the damage reached the predentin. At all observed stages, more tartrate-resistant acid phosphatase (TRAP)-positive cells were found on the surface of cementum in Opg-KO mice. In vitro, the mRNA levels of cathepsin K, TRAP, matrix metalloproteinase-9, and matrix metalloproteinase-1, as well as the protein expression of nuclear factor of activated T cell 1 and TRAP, increased significantly in osteoclast-like cells from Opg-KO mice. In addition, the cementum resorption pits of Opg-KO mice were larger when co-cultured with osteoclast-like cells. CONCLUSIONS: Our study demonstrated that loss of OPG led to root resorption via increasing activation of osteoclasts and reducing mineralization of cementum.

Osteoprotegerin deficiency leads to deformation of the articular cartilage in femoral head.

Osteoarthritis (OA) was a degenerative joint disease characterized by articular cartilage degradation and extensive remodeling of the subchondral bone. Multiple lines of evidence indicated that Osteoprotegerin (OPG), a member of TNF receptor superfamily that was expressed in the chondrocytes of articular cartilage and adjacent locations in the physiological setting, was involved in maintaining integrity of articular cartilage. OPG could prevent subchondral bone from resorption, and also protect cartilage from degradation. In this study, we used Osteoprotegerin-knockout mice (Opg-KO mice) to find out the role of OPG in articular cartilage. We examined articular cartilage in the femoral head of Opg-KO mice began in early adulthood using modern molecular and imaging methods. We found cartilage changes starting from adulthood and progressively with age, reminiscent of pathological changes in OA. Deficiency of OPG caused thinned articular cartilage and extensive remodeling of the subchondral bone in femoral head in comparison with wild-type mice (WT mice). Also, the articular cartilage of femoral head expressed significantly less of Aggrecan, Col-II and Col-X, but more Col-I and Matrix Metalloproteinases-13 (Mmp-13) than WT mice both at gene and protein level. Moreover, increased chondrocyte apoptosis and decreased chondrocyte proliferation were observed in femoral head of Opg-KO mice compared to WT mice. These data suggested that OPG played an important role in maintaining the homeostasis of articular cartilage of femoral head.

Comparison of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeters in glaucoma patients.

PURPOSE: The purpose of this study was to compare the accuracy and reproducibility of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeter in glaucoma patients under treatment. METHODS: Prospective study of 65 glaucoma patients. Central corneal thickness was measured by two ultrasound pachymeters: the hand-held, portable PachPen (Accutome, Lynwood, WA), and the desk-mounted PacScan 300 (Sonomed, Lake Success, NY). RESULTS: The mean ± SD central corneal thickness was 526.5 ± 44.8 µm and 530.0 ± 44.7 µm for the hand-held and desk-mounted pachymeters, respectively (p = 0.15). Linear regression analysis revealed a slope of 0.97 with Pearson correlation coefficient of 0.96. Bland-Altman analysis showed a mean difference of measurements by both pachymeters of 3.22 µm with two standard deviations = 9.51. Both instruments showed high intraobserver correlation: 0.972 for the hand-held pachymeter and 0.993 for the desk-mounted pachymeter. CONCLUSION: Central corneal thickness measurements were comparable with the use of hand-held and desk-mounted ultrasound units in glaucoma patients with good intraobserver reproducibility.

Comparison of intraocular pressure measurements and assessment of intraobserver and interobserver reproducibility with the portable ICare rebound tonometer and Goldmann applanation tonometer in glaucoma patients.

PURPOSE: The goals of our study were to analyze the correlation of rebound tonometer (RBT) and Goldmann applanation tonometer (GAT), assess the intraobserver and interobserver reproducibility of these tonometers, and investigate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements recorded with both tonometers in glaucoma patients under treatment. METHODS: In a prospective study of 65 eyes with glaucoma, IOP was measured using RBT and GAT, followed by measurements of CCT. RESULTS: A clear correlation between RBT and GAT was found (r=0.89, P<0.001). Bland-Altman analysis showed a mean difference of measurements by GAT and RBT of 2.45 mm Hg with 2 SD=4.24 mm Hg. Both tonometers were affected by CCT. High intraobserver correlation coefficients were found with both tonometers (0.981 and 0.979 for RBT for examiner 1 and examiner 2, respectively, and 0.989 for GAT for both examiners). Interobserver agreement appeared to be better with GAT when compared with RBT (variation coefficients were 4.6% for GAT and 7.1% for RBT). CONCLUSIONS: RBT may have a potential role and use in routine evaluation and management of glaucoma patients given its high correlation with GAT and high reproducibility in IOP measurements. As with GAT, measurements obtained with RBT are affected by CCT, reinforcing the role of pachymetry in glaucoma management.

Surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients.

PURPOSE: To compare the surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients. DESIGN: Retrospective comparative case series. METHODS: This was a comparative case series of 36 eyes of 36 African Americans and 43 eyes of 43 whites that underwent placement of the Ex-PRESS glaucoma filtration device under a partial-thickness scleral flap for uncontrolled glaucoma. All eyes received intraoperative mitomycin C. The primary outcome measures were intraocular pressure (IOP), number of postoperative glaucoma medications, and surgical success. Surgical success was defined as IOP between 5 and 18 mm Hg, with or without glaucoma medications, without further glaucoma surgery, or loss of light perception vision. RESULTS: Average follow-up was 31.9 ± 9.8 (range, 14.6-47) months for African Americans and 30.7 ± 8.6 (range, 14.3-47) months for whites. At 33 months, surgical success was 80.0% in the African American group and 83.3% in the white group (P = 1.00). Reasons for surgical failure included increased IOP (3 eyes, 3.8%), persistent hypotony with maculopathy (1 eye, 1.3%), and further surgery (4 eyes, 5.06%). Compared with preoperative values, the mean postoperative IOP and number of glaucoma medications were significantly reduced in both groups, and no statistical difference was observed between the two groups at 33 months. Postoperative complications were similar in the two groups. CONCLUSIONS: Similar surgical outcomes were observed in African American and white glaucoma patients after implantation of the Ex-PRESS glaucoma filtration device. This latest modification of glaucoma filtration surgery may be a better surgical option for African Americans given its potential advantages of no tissue removal, predictable outcomes related to consistent lumen size and controlled flow, fewer postoperative complications, and overall reduced inflammation.

Trabeculectomy versus Ahmed Glaucoma Valve implantation in neovascular glaucoma.

PURPOSE: To compare surgical outcomes in neovascular glaucoma patients who underwent trabeculectomy with mitomycin C versus Ahmed Glaucoma Valve implantation. PATIENTS AND METHODS: This was a retrospective comparative case series. We reviewed 40 eyes of 39 patients with underlying diagnosis of neovascular glaucoma, divided into two groups: Ahmed Glaucoma Valve (N = 20) and trabeculectomy with mitomycin C (N = 20). Surgical success was defined as 6 mm Hg ≤ intraocular pressure ≤21 mm Hg, with or without the use of glaucoma medications, with no further glaucoma surgery, and light perception or better vision. Early postoperative hypotony was defined as intraocular pressure <5 mm Hg during the first postoperative week. RESULTS: The average follow-up was 31 months (range 6-87 months) for the Ahmed Glaucoma Valve group and 25 months (6-77 months) for the trabeculectomy group. Although the mean number of postoperative intraocular pressure-lowering medications was significantly higher in the trabeculectomy group compared with the Ahmed Glaucoma Valve group at 3 and 6 month time points, there was no statistically significant difference at any other time point. There was no statistically significant difference between both groups in postoperative visual acuity and intraocular pressure. Success was 70% and 65% at 1 year and 60% and 55% at 2 years after Ahmed Glaucoma Valve and trabeculectomy, respectively. Kaplan-Meier survival curve analysis showed no significant difference in success between the two groups (P = 0.815). Hyphema was the most common complication in both groups. CONCLUSION: We found similar results after trabeculectomy with mitomycin C and Ahmed Glaucoma Valve implantation in eyes with neovascular glaucoma.

Dietary RRR-α-tocopherol succinate attenuates lipopolysaccharide-induced inflammatory cytokines secretion in broiler chicks.

The anti-inflammatory effects of two esters of a-tocopherol (α-TOH), all-rac-α-TOH acetate (DL-α-TOA) and RRR-α-TOH succinate (D-α-TOS), on broilers repeatedly challenged with lipopolysaccharide (LPS) were investigated. Three hundred and twenty 1-d-old broiler chicks were allotted into four treatment groups and fed on a control diet (30 mg/kg DL-α-TOA) or diets containing 10, 30, 50 mg/kg D-α-TOS. Half of the birds from each treatment group were challenged with 0·9% NaCl solution or LPS (250 µg/kg body weight) at 16, 18 and 20 d of age. The results indicated that the pretreatment of birds with 50 mg/kg D-α-TOS markedly reduced serum PGE2 secretion and increased the concentrations of serum or hepatic α-TOH. When LPS-challenged birds were pretreated with 30 or 50 mg/kg D-α-TOS, the increases of plasma and splenic concentrations of interferon-γ, IL-1ß, IL-2, IL-6, IL-4 and IL-10 were dramatically attenuated. Also, a significant decrease of hepatic reactive oxygen species (ROS) and hepatic or splenic phosphokinase C (PKC) activities was found in birds pretreated with 30 or 50 mg/kg D-α-TOS. Furthermore, D-α-TOS inhibited the activation of NF-κB by preventing the degradation of inhibitory-κBα. In conclusion, D-α-TOS is able to prevent LPS-induced inflammation response in vivo. The beneficial effect may depend on suppressing the secretion of various plasma and splenic inflammatory mediators through inhibiting NF-κB activation and by blocking ROS signalling, in which PKC may play an assistant role.

Ex-PRESS miniature glaucoma device implanted under a scleral flap alone or combined with phacoemulsification cataract surgery.

PURPOSE: Our purpose was to evaluate the clinical outcomes of the Ex-PRESS miniature glaucoma device placed under a partial-thickness scleral flap as a single procedure or combined with phacoemulsification cataract surgery. METHODS: This was a comparative consecutive case series of 345 eyes: 231 eyes treated with Ex-PRESS implant under scleral flap alone and 114 eyes treated with Ex-PRESS implant under scleral flap combined with phacoemulsification (both groups were treated intraoperatively with mitomycin C). RESULTS: The patients were followed for 25.7+/-11.1 (range, 1 to 46.2) months (Ex-PRESS alone) and 21.9+/-12.5 (range, 1.9 to 46.2) months (combined cases). At 3 years after surgery, surgical success was 94.8% and 95.6% in the Ex-PRESS and combined groups, respectively (P=0.948). Compared with baseline values, the postoperative intraocular pressure (IOP) and number of glaucoma medications were significantly lowered in both groups. The change from baseline IOP was significantly greater after Ex-PRESS implant alone compared with combined surgery (P<0.001). The most common device-related complication was obstruction of the tube (6 eyes), which was treated successfully with Nd:YAG laser in all 6 eyes. CONCLUSIONS: The use of the Ex-PRESS implant under a scleral flap was effective for lowering IOP both alone and combined with cataract surgery. The most common device-related complication was tube blockage, which was treated with the Nd:YAG laser.

A recombinant protein and a chemically synthesized peptide containing the active peptides of the platelet collagen receptors inhibit ferric chloride-induced thrombosis in a rat model.

We have previously reported that a recombinant protein (M(r) 47 kDa), which contains both active peptide of platelet receptors for types I and III collagen inhibits both types I and III collagen-induced platelet aggregation. In order to eliminate non-reactive portion of the protein, we have constructed a recombinant of rHyB (M r 6 kDa). In addition, we chemically synthesized a hybrid peptide with 30 amino acid residues (cHyB, M r 3 kDa) that contains each of the active peptide derived from platelet receptors for types I and III collagen and a linker of 12 amino acid residues. In the present investigation, we report that both rHyB and cHyB inhibit type I and type III collagen-induced platelet aggregation, and the adhesion of radiolabeled platelets onto rabbit aortic segments in a dose-dependent manner. We have used an animal model, which employs FeCl3 to induce thrombi formation to study the effectiveness of both rHyb and cHyB on preventing thrombi formation. We obtained results that show that both rHyB and cHyB can inhibit thrombi formation in a dose-dependent manner. These results suggest that either rHyB or cHyB may be a possible therapeutic agent in preventing thrombi formation.

Polyamines in cultured rabbit corneal cells.

PURPOSE: To determine whether polyamines are present in corneal cells, whether corneal cell polyamines can be depleted by blocking the first rate-limiting enzyme in the polyamine synthesis pathway, ornithine decarboxylase (ODC), and whether polyamines are required for proliferation in all three corneal cell types. METHODS: Cultured corneal epithelial cells, keratocytes, and endothelial cells were exposed to the specific ODC blocker difluoromethylornithine (DFMO), and ODC activity, intracellular polyamine concentrations, and cell proliferation were measured. RESULTS: DFMO blocked ODC activity in a dose- and time-dependent manner in all three cell types. DFMO treatment completely depleted putrescine and spermidine by 2 days and also significantly depleted spermine. DFMO treatment also inhibited cell growth in all three cell types and this inhibition could be completely reversed by adding exogenous putrescine to the culture medium. CONCLUSIONS: Polyamines are present in all cell types of the cornea, their formation is catalyzed at least in part by ODC, and they are an important component of corneal cell proliferation.

Injury-elicited differential transcriptional regulation of phospholipid growth factor receptors in the cornea.

The phospholipid growth factors (PLGFs), including lysophosphatidic acid (LPA), have been implicated in corneal wound healing. PLGF concentrations and activities are elevated after corneal injury. Using real-time PCR, we quantified receptor mRNA levels in the healing rabbit cornea. In intact corneas, transcripts for S1P(1), LPA(1), and LPA(3) receptor subtypes were detected, as was lipid phosphate phosphatase 1 (LPP1). After wounding, the trend for endothelium and keratocytes was for significant decreases in transcript numbers for the three receptor subtypes, whereas epithelial cells showed increased transcript numbers, except for an S1P(1) decrease in healing cells. LPP1 transcript numbers were decreased in keratocytes and endothelium, although LPP-specific activity was unchanged. LPA-elicited Ca(2+) transients were significantly reduced in the healing endothelium. Consistent with reduced LPA(3) receptor numbers, dioctylglycerol pyrophosphate, a selective antagonist, reduced LPA-induced Ca(2+) transients 2.7-fold in nonwounded epithelium but only 1.5-fold in wound-healing endothelium. These data for the first time establish physiologically relevant differential changes in the expression of PLGF receptor subtypes and provide evidence for the changing role of LPA(3) receptors in endothelial cells.