[Attach importance to the orderly development of different corneal transplant procedures]

There are various surgical methods for corneal transplantation, each requiring precise treatment tailored to the characteristics and different layers of corneal opacity or lesions. These layers include the corneal epithelium, stroma (lamellar), and corneal endothelium, with options for full-thickness (penetrating) corneal transplantation or artificial corneal transplantation. However, a current issue in clinical practice is that, regardless of the degree of corneal disease, the availability of corresponding eye bank support, or surgical conditions, classic penetrating (full-thickness) corneal transplantation is universally performed. Alternatively, there is a trend toward adopting technically demanding procedures such as endothelial transplantation and artificial corneal transplantation. This trend has led to increased postoperative complications and the wastage of corneal donor materials. Choosing the appropriate corneal transplant procedure can offer advantages such as preserving more healthy corneal tissue, conserving corneal donors, facilitating rapid vision recovery, and minimizing the risk of immune rejection. Corneologists need to master the indications for various corneal transplant surgeries and systematically perform different corneal transplant procedures based on the surgeon's skills, hospital conditions, and eye bank conditions. This approach aims to enhance the success rate of the surgery.

[Intraoperative optical coherence tomography guided precise corneal suture in the treatment of acute keratoconus]

Objective: This study aimed to observe the clinical efficacy of precise suturing of posterior elastic layer fissures guided by intraoperative optical coherence tomography (OCT) in conjunction with anterior chamber puncture and drainage, and corneal thermokeratoplasty for the treatment of severe acute edematous keratoconus. Methods: Non-randomized controlled trial. Data were collected for a study involving 31 cases of acute edematous keratoconus patients who underwent surgical treatment at the Shandong Eye Hospital between June 2017 and July 2021. Among them, there were 30 male and 1 female patients, with an age range of 11 to 32 years and a mean age of (19.80±5.80) years. Eighteen patients in the study group underwent precise suturing of posterior elastic layer fissures guided by intraoperative OCT, in combination with anterior chamber puncture and drainage, and corneal thermokeratoplasty. Thirteen patients in the control group did not undergo suturing. Preoperative visual acuity, corneal edema diameter, corneal thickness, and posterior elastic layer fissure length were collected. Evaluation was performed using slit lamp microscopy, anterior segment OCT, and other methods to assess the time of initial postoperative corneal edema resolution and closure of the posterior elastic layer fissure. Deep lamellar keratoplasty was performed 2 to 4 weeks after edema resolution, and the corneal bed scar repair and visual acuity of the two groups were compared. Results: In the suturing group, the corneas of all 18 patients were accurately sutured to the deep stromal layer near the posterior elastic layer. The time for corneal edema resolution was 2.50 (1.00, 6.25) days in the suturing group and 7.00 (6.00, 10.50) days in the control group. The fissure healing time was 7.50 (7.00, 12.00) days in the suturing group and 14.00 (9.00, 14.00) days in the control group. The differences were statistically significant (all P<0.05). After 2 weeks, the central corneal thickness decreased to (529.80±174.50) μm in the suturing group and (612.00±205.12) μm in the control group. The suturing group showed accurate corneal suturing to the deep stromal layer near the posterior elastic layer, resulting in central corneal flattening, closure of voids in the stroma, and a significant decrease in corneal thickness. All 18 patients in the suturing group successfully completed deep lamellar keratoplasty, with 6 cases (6/18) experiencing mild graft bed leakage during surgery but without affecting the deep lamellar keratoplasty. One year postoperatively, the visual acuity (logarithm of the minimum resolution angle) was 0.23±0.12 in the suturing group and 0.33±0.11 in the control group, with a statistically significant difference (P<0.05). Conclusions: In the treatment of severe acute edematous keratoconus, precise suturing of posterior elastic layer fissures guided by intraoperative OCT, in conjunction with anterior chamber puncture and drainage, and corneal thermokeratoplasty, can rapidly alleviate corneal edema and promote the healing of posterior elastic layer fissures. This approach achieves better visual outcomes for subsequent lamellar keratoplasty surgeries. The use of intraoperative OCT guidance allows accurate positioning of the posterior elastic layer fissure in terms of location, direction, and depth of corneal stromal voids, thereby assisting surgeons in precise suturing.

[Analysis of factors affecting the quality of donor corneal endothelial cells]

Objective: To explore the factors influencing the quality of donor corneal endothelium. Methods: A retrospective case series study was conducted. Data from 568 donor corneas obtained from the Shandong Eye Bank between July 1, 2020, and June 30, 2021, were collected for analysis. The corneal endothelium of the donor corneas was observed using corneal endothelial microscopy to assess corneal endothelial cell density (ECD), coefficient of variation, and hexagonal cell ratio (HEX). Relevant factors of corneal donors were collected, including gender, age, cause of death, season of death, time from death to corneal retrieval, and methods of corpse preservation, to investigate their impact on the quality of donor corneal endothelium. The age factor was divided into five age groups: 0-20 years, 21-40 years, 41-60 years, 61-80 years, and >80 years. The time of corneal retrieval was divided into three periods based on the time elapsed since the donor's death: <6 hours, 6-12 hours, and >12 hours. The relationship between these factors and corneal endothelial conditions was analyzed. Results: The 568 donor corneas were obtained from 288 donors, including 225 males (78.13%) and 63 females (21.87%). The mean age was 51.77±18.48 years. The causes of death among donors were as follows: cardiovascular diseases 54.58% (275 individuals), cancer 17.96% (74 individuals), organ failure 14.26% (49 individuals), and accidents 13.20% (64 individuals). The mean time of corneal retrieval after donor death was 140 (76, 400) minutes (ranging from 30 minutes to 45 hours). Among the 145 corneas (25.53%) that had their initial corneal endothelial microscopy examination, the images were not clear, and after thorough rewarming, 106 corneas (18.7%) still had unclear images and could not be analyzed. Among the 462 corneas (81.3%) with clear images, the ECD was (2 602.23±318.40) cells/mm², the coefficient of variation was 36.61%±4.81%, and the HEX was 52.73%±7.15%. The ECD of corneas from older donors was lower compared to younger donors, and the differences between age groups were statistically significant (P<0.001). Corneas from donors who died due to accidents had a higher ECD [(2 829.88±313.90) cells/mm²] compared to those who died from cancer, cardiovascular diseases, and organ failure, and the differences were statistically significant (P<0.001). The ECD was highest when corneas were retrieved within 6 hours after death, and the difference was statistically significant (P<0.001). Older donors had higher coefficients of variation but lower HEX values (both P<0.05). Corneas retrieved after a longer time from death had higher coefficients of variation, and the difference was statistically significant (P<0.05), but there was no statistically significant difference in HEX (P>0.05). Organ failure, cryopreservation, and corneal retrieval time >12 hours were risk factors for unclear corneal endothelial imaging (all P<0.001). Among the 136 corneal endothelial images (23.94%), circular, oval, or band-shaped dark areas were observed, and corneas with dark areas had lower ECD (P<0.05). The longer the time elapsed from death to corneal retrieval, the more dark areas were observed (P<0.001). The presence of dark areas did not affect the coefficient of variation and HEX (P>0.05). Conclusion: Advanced donor age, death due to chronic diseases, longer time elapsed from death to corneal retrieval, and cryopreservation of the body lead to a decrease in the quality of donor corneal endothelium.

[Application of intraoperative optical coherence tomography in deep lamellar keratoplasty]

Objective: To evaluate the clinical application value of intraoperative optical coherence tomography (iOCT) in deep anterior lamellar keratoplasty (DALK) using the big-bubble technique to bare Descemet's membrane. Methods: Retrospective case series. Clinical data of 92 patients (92 eyes) with monocular stromal corneal diseases who underwent big-bubble DALK in the Eye Hospital of Shandong First Medical University from January 2020 to August 2021 were collected. There were 53 males and 39 females. The average age was (53.2±16.0) years old. All patients underwent iOCT scanning to determine the location and depth of the injection needle after initial removal of the corneal lesion, to observe the integrity of the recipient bed, Descemet's membrane, after complete lesion removal, and to observe the adhesion between the corneal graft and the recipient bed and check folds on the recipient bed after suturing of the corneal graft. The intraoperative perforation of Descemet's membrane, postoperative thickness of the cornea and the recipient bed, visual acuity, and corneal astigmatism were recorded. Results: By iOCT, the thickness of the recipient bed was found to be about 1/2 of the corneal thickness and relatively uniform in all directions in 62 eyes (67.4%), so the sterile air was injected from the center of the recipient bed to separate it from the stromal layer. In 30 eyes (32.6%) with an uneven thickness of the recipient bed, the sterile air was injected from the paracentral area of the recipient bed. Under the guidance of iOCT scanning, 89 eyes (96.7%) did not experience any perforation of Descemet's membrane during surgery. The Descemet's membrane folds in the central 5-mm area of the recipient bed was observed and flattened in 20 eyes with the assistance of iOCT scanning. The postoperative corneal thickness was (578.95±108.26) μm, and the recipient bed thickness was (36.06±23.11) μm. The best corrected visual acuity of all patients at 6 months after surgery was 0.57±0.25 logMAR, which was significantly better than that before surgery (1.61±1.27 logMAR; P<0.001). The average corneal astigmatism at 6 months after surgery was (2.72±2.44) diopters. Conclusions: The application of iOCT scanning in DALK surgery assisted by the big-bubble method can provide safe guidance for surgeons to adopt correct surgical procedures, decrease the risk of Descemet's membrane perforation, reduce the recipient bed folds, and facilitate corneal interlayer adhesion, thereby improving the visual prognosis.

Novel insights from spatial transcriptome analysis in solid tumors

Since its first application in 2016, spatial transcriptomics has become a rapidly evolving technology in recent years. Spatial transcriptomics enables transcriptomic data to be acquired from intact tissue sections and provides spatial distribution information and remedies the disadvantage of single-cell RNA sequencing (scRNA-seq), whose data lack spatially resolved information. Presently, spatial transcriptomics has been widely applied to various tissue types, especially for the study of tumor heterogeneity. In this review, we provide a summary of the research progress in utilizing spatial transcriptomics to investigate tumor heterogeneity and the microenvironment with a focus on solid tumors. We summarize the research breakthroughs in various fields and perspectives due to the application of spatial transcriptomics, including cell clustering and interaction, cellular metabolism, gene expression, immune cell programs and combination with other techniques. As a combination of multiple transcriptomics, single-cell multiomics shows its superiority and validity in single-cell analysis. We also discuss the application prospect of single-cell multiomics, and we believe that with the progress of data integration from various transcriptomics, a multilayered subcellular landscape will be revealed.

[A multicenter clinical trial of collar-button type keratoprosthesis implantation for the treatment of corneal blindness in high-risk transplantation]

Objective: To evaluate the efficiency and safety of collar-button type keratoprosthesis (c-bKPro) implantation for corneal blindness in high-risk transplantation in China. Methods: It was a case series study. High-risk corneal blind patients who planned to undergo c-bKPro implantation were prospectively and continuously enrolled in the Eye Hospital of Shandong First Medical University, Ophthalmology Division of Chinese PLA General Hospital, Zhongshan Ophthalmic Center, Department of Ophthalmology in Eye & ENT Hospital of Fudan University, and Eye Hospital of Wenzhou Medical University from July 2019 to January 2020. The cure for blindness and surgical success were assessed based on visual acuity (VA)≥0.05. The complications and keratoprosthesis retention rate were recorded to determine the safety of the surgery. Results: Thirty-seven subjects (eyes) were included, of which 32 were male and 5 were female, aged 27 to 72 years old. The indications of c-bKPro implantation were corneal graft failure (21 eyes, 56.8%), chemical injury (8 eyes, 21.6%), thermal burn (5 eyes, 13.5%), unexplained corneal opacity (2 eyes, 5.4%), and corneal perforation (1 eye, 2.7%). Two patients withdrew from the clinical trial at 3 months postoperatively. Thirty-five patients were followed up for 6 months, and 31 were followed up for 12 months. The VA was ≥0.05 in 83.8% of eyes at 6 months and in 81.8% of eyes at 12 months. Among the 11 eyes diagnosed with concurrent glaucoma, 6 eyes achieved a VA of ≥0.05. At 12 months, the c-bKPro retention rate was 100%. The surgical complications included retroprosthetic membrane formation (5 eyes, 16.1%), persistent corneal epithelial defects (5 eyes, 16.1%), macular edema (4 eyes, 12.9%), new-onset glaucoma (4 eyes, 12.5%; including one eye withdrawn from the study at 3 months), sterile corneal melting (2 eyes, 6.5%), sterile vitritis (1 eye, 3.2%), and infectious keratitis (1 eye, 3.2%). Conclusions: C-bKPro implantation is an effective and safe option for treating corneal blindness in high-risk transplantation in China. Improved visual outcomes could be achieved in most cases, with a relatively low incidence of postoperative complications.

[Femtosecond laser-assisted minimally invasive lamellar keratoplasty for advanced keratoconus]

Objective: To evaluate the initial safety and efficacy of femtosecond laser-assisted minimally invasive lamellar keratoplasty (FL-MILK) for advanced keratoconus. Methods: It was a case series study. Patients with advanced keratoconus who underwent FL-MILK between August 2017 and April 2020 at Shandong Eye Hospital were prospectively included. The femtosecond laser was used to create an intrastromal pocket in the recipient cornea and a lamellar cornea in the donor. The lamellar cornea was then gently inserted into the intrastromal pocket through the incision and flattened. Clinical measurements included best-corrected visual acuity, 3-mm anterior corneal mean keratometry, anterior and posterior central corneal elevation, central corneal thickness, corneal biomechanics, and endothelial cell density. The follow-up was conducted at 1 month, 12 months, and 24 months after the operation. Results: There were 33 patients (35 eyes) in the study. Twenty-six patients were male and 7 patients were female. The mean age was (20.34±5.24) years old. All patients completed 12 months of follow-up, and 25 patients (27 eyes) completed 24 months of follow-up. No epithelial ingrowth, infection, or allogeneic rejection was observed. Compared with the preoperative data, the anterior central corneal elevation significantly decreased (P<0.001), the mean keratometry significantly decreased (P<0.05), and the central corneal thickness significantly increased (P<0.001). The corneal biomechanical strength was significantly improved, with the deformation amplitude ratio at 2.0 mm decreasing from 1.39±0.14 preoperatively to 1.21±0.10 at 24 months postoperatively (P<0.001) and the stiffness parameter at the first applanation increasing from 41.49±11.47 preoperatively to 88.41±18.17 at 24 months postoperatively (P<0.001). There were no significant changes in the mean best-corrected visual acuity, posterior corneal elevation, mean spherical equivalent, and endothelial cell density (all P>0.05). Conclusions: FL-MILK may be a feasible option for advanced keratoconus. This procedure may provide a new resolution for keratoconus.

[Comparative analysis of metagenomic and 16S rDNA sequencing in gut microbiota of healthy elderly]

Objective: To explore the differences in subsequent analysis between metagenomic and 16Sr DNA sequencing in compositionally characterizing gut microbiota of healthy elderly. Methods: By using a panel study design, five monthly repeated measurements were performed among 76 healthy older people in Jinan City, Shandong Province. Their fecal samples were collected, and genomic DNA was extracted and analyzed through metagenomic and 16Sr DNA sequencing to compare the composition and diversity of gut microbiota. The correlation between species abundance and α diversity was analyzed by Pearson correlation analysis, and the correlation between species abundance and β diversity was determined by Procrustes analysis. Results: The age of 76 participants was (65.07±2.75), and the body mass index was (25.03±2.40) kg/m². There were 38 males and 38 females. A total of 345 fecal samples were obtained from five monthly repeated measurements. Compared with 16S rDNA sequencing, metagenomic sequencing showed more annotated species at each level. The difference in the number of two sequencing species increased with the decrease of the level. Although there were significant differences in species richness between the two sequencing methods. Their species richness was highly correlated at both phylum (r=0.88, P<0.001) and genus (r=0.77, P<0.001) levels. Bacteroidetes and Firmicutes were the common dominant species. Gut microbiota diversity analysis further showed that there was a significantly positive correlation between α diversity (r=0.70, P<0.001) and β diversities (M²=0.84, P<0.05) in the two groups. Conclusion: The annotation efficiency of metagenomic sequencing is much higher than that of 16S rDNA sequencing. The two sequencing methods are consistent in phylum abundance as well as α diversity.

[Associations between personal fine particulate matter and blood lipid profiles: A panel study in Chinese people aged 60-69 years]

Objective: To explore the association between short-term exposures to fine particulate matter (PM_2.5) on blood lipids in the elderly. Methods: In this panel study, five repeated measurements were performed on 76 people aged 60-69 in Jinan city. Each participant had a PM_2.5 monitor for 72 hours before each health examination, including a questionnaire survey, physical examination, and biological sample collection. Serum triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were examined, and non-HDL-C concentrations were calculated by subtracting HDL-C from TC. The generalized linear mixed-effects model was used to quantify the association of personal PM_2.5 exposure at different lag with blood lipids and dyslipidemia. Results: The age of 70 participants was (65.0±2.8) years, of which 48.6% (34/70) were males. The BMI of participants was (25.0±2.5) kg/m². Their TC, TG, LDL-C, HDL-C, and non-HDL-C concentrations were (5.75±1.32), (1.55±0.53), (3.27±0.94), (1.78±0.52), and (3.97±1.06) mmol/L, respectively. Generalized linear mixed-effects model showed that after adjusting for confounding factors, at lag 72 hours, each 10 μg/m³ increase in PM_2.5 was associated with the percentage change in TC, LDL-C, HDL-C and non-HDL-C about 1.77% (95%CI: 1.22%-2.32%), 1.90% (95%CI: 1.18%-2.63%), 1.99% (95%CI: 1.37%-2.60%) and 1.74% (95%CI: 1.11%-2.37%), and the OR values (95%CI) of hypercholesterolemia, hypertriglyceridemia and hyperbetalipoproteinemia were 1.11 (1.01-1.22), 1.33 (1.03-1.71) and 1.15 (1.01-1.31), respectively. Conclusion: There is a significant association of short-term PM_2.5 exposure with the concentration of blood lipids and the risk of dyslipidemia in the elderly.

[Strengthening basic and clinical research on ocular infection caused by coronavirus]

This article was published ahead of print on the official website of Chinese Jounal of Ophthalmology on February 19, 2020. The prevention and treatment of coronavirus disease 2019 (COVID-2019) has reached the critical stage in China. Ocular surface represents a possible route for infection. Based on the previous studies and our own research, we summarize the potential transmission route and clinical symptoms of COVID-2019 in the eye, as well as the further prevention and research, with the expectation of contributing to the development in the field of infectious eye disease in China. (Chin J Ophthalmol, 2020, 56:250-252).

[Association of sleep with anxiety in the elderly aged 60 years and older in China]

Objective: To investigate the relationship of sleep duration and sleep quality with anxiety in the elderly aged 60 years and older in China. Methods: The elderly aged 60 years and older were selected from the China Short-term Health Effects of Air Pollution Study conducted between July 18, 2017 and February 7, 2018. Multivariate logistic regression models were used to analyze the association of sleep duration and sleep quality with anxiety. Results: A total of 3 897 elderly aged 60 years and older were included in the study. The age of the elderly was (73.4±8.0) years old. Among the elderly surveyed, 6.5% were defined with anxiety, and 18.7% reported poor sleep quality. Multivariate logistic regression models showed shorter sleep duration was the risk factor for anxiety in the elderly that after adjusting for factors such as general demographics, socioeconomic factors, lifestyle, health status, social support and ambient fine particulates exposure. Compared with the elderly with 7 hours of sleep duration daily, the OR (95%CI) of anxiety for those with sleep duration ≤ 6 hours was 2.09 (1.49-2.93). Compared with those with good sleep quality, the OR (95%CI) of anxiety for those with poor sleep quality was 5.12 (3.88-6.77). We also found statistically significant correlations of the scores of subscales of Pittsburgh sleep quality index with anxiety, in which the effects of sleep disturbance, subjective sleep quality and daytime dysfunction scores were most obvious, the ORs (95%CI) were 4.63 (3.55-6.04), 2.75 (2.33-3.23) and 2.50 (2.19-2.86), respectively. Subgroup analysis showed that the association of sleep duration and sleep quality with anxiety was more obvious in males and in those aged <80 years. Conclusion: Shorter sleep duration and poor sleep quality are associated with anxiety in the elderly in China.

[Prediction of 6-year incidence risk of chronic kidney disease in the elderly aged 65 years and older in 8 longevity areas in China]

Objective: To establish a prediction model for 6-year incidence risk of chronic kidney disease (CKD) in the elderly aged 65 years and older in China. Methods: In this prospective cohort study, we used the data of 3 742 participants collected during 2008/2009-2014 and during 2012-2017/2018 from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey. Two follow up surveys for renal function were successfully conducted for 1 055 participants without CKD in baseline survey. Lasso method was used for the selection of risk factors. The risk prediction model of CKD was established by using Cox proportional hazards regression models and visualized through nomogram tool. Bootstrap method (1 000 resample) was used for internal validation, and the performance of the model was assessed by C-index and calibration curve. Results: The mean age of participants was (80.8±11.4) years. In 4 797 person years of follow up, CKD was found in 262 participants (24.8%). Age, BMI, sex, education level, marital status, having retirement pension or insurance, hypertension prevalence, blood uric acid, blood urea nitrogen and total cholesterol levels and estimated glomerular filtration rate in baseline survey were used in the model to predict the 6-year incidence risk of CKD in the elderly. The corrected C-index was 0.766, the calibration curve showed good consistence between predicted probability and observed probability in high risk group, but relatively poor consistence in low risk group. Conclusion: The incidence risk prediction model of CKD established in this study has a good performance, and the nomogram can be used as visualization tool to predict the 6-year risk of CKD in the elderly aged 65 years and older in China.

[Efficacy of double-incision extracapsular cataract extraction in the treatment of hard-nucleus cataract with low corneal endothelial cell density]

Objective: To discuss the efficacy and security of double-incision extracapsular cataract extraction (ECCE) in the treatment of hard-nucleus cataract with low corneal endothelial cell density. Methods: This was a retrospective case series study. Forty-six patients (47 eyes) with hard-nucleus cataract and low corneal endothelial cell density were enrolled at Shandong Eye Hospital from June 2009 to December 2018, including 22 males and 24 females, aged 50 to 74 (63.8±6.3) years. Preoperative corneal endothelial cell density was less than 1 000 cells/mm(2), and the cataract nuclear hardness was equal to or greater than grade IV. According to the surgical methods, the patients were divided into the single-incision ECCE group (24 eyes) and the double-incision ECCE group (23 eyes). The surgical procedures for the double-incision group were as follows. First, a superior scleral pre-incision was made. Then the conventional capsulorhexis was conducted through a 2.6 mm transparent corneal tunnel incision at the temporal or the nasal side, after which the hydro-dissection was performed. Next, the surgeon cut the pre-incision at the sclera, delivered the lens nucleus, sutured the scleral incision and removed the residual cortical materials from the corneal incision. Finally, a foldable intraocular lens was implanted, and the viscoelastic substance was removed. The intraoperative anterior chamber condition and the postoperative corneal edema condition were monitored. During the 6 month follow-up after surgeries, the endothelium cell density, visual acuity and astigmatism in the two groups were compared. The χ(2) test was used to compare the counting data, and the t test was used to compare the measurement data. Results: There was no statistically significant difference (t=1.12, P=0.28) in the preoperative corneal endothelial cell density between the double-incision and single-incision ECCE groups, which was (827±164) cells/mm(2) and (802±121) cells/mm(2), respectively. At 6 months after operation, in the double-incision and single-incision groups, the endothelial cell density was (793±147) cells/mm(2) and (706±101) cells/mm(2), respectively, and the difference was statistically significant (t=4.37, P<0.01). The percentage of corneal endothelial cell loss was 4.16%±3.12% and 11.69%±2.96%, respectively, and the difference was also statistically significant (t=9.52, P<0.01). The hexagon loss rate of corneal endothelial cells was 9.67%±6.11% and 28.33%±8.39%, respectively, and the difference was statistically significant (t=5.52, P<0.05). In the follow-up of 6 months, none of the eyes in the double-incision ECCE group suffered corneal endothelial decompensation compared with 3 eyes in the single-incision ECCE group. There were no statistically significant differences in postoperative astigmatism and surgically induced astigmatism between the two groups (t=-0.71, 0.15; P>0.05). Conclusions: The double-incision ECCE, in which the lens nucleus is delivered through a scleral incision and other procedures are conducted through a corneal tunnel incision, is safe and effective for cataract patients with hard nucleus and low corneal endothelial cell density. (Chin J Ophthalmol, 2020, 56: 126-130).

[The rapid development and changes of corneal refractive surgery in China]

Corneal refractive surgery in China, represented by laser corneal surgery, has undergone great changes in recent 30 years. Almost one million corneal refractive surgeries are performed each year. With the rapid technological innovation, the corrective effect is constantly higher, and complications are continuously controlled and reduced. The team of practitioners keeps expanding, and the academic strength is approaching the international level. With the application and promotion of various new technologies, the formulation of relevant norms and the increase of academic researches, corneal refractive surgery in China has stepped into the stage of diversification, intelligence and standardization. However, we should recognize the shortcomings while facing the great achievements. More efforts are still needed to provide the best visual quality and natural vision correction effect for patients. We would like to send congratulations on the 70th anniversary of Chinese Journal of Ophthalmology with this article. (Chin J Ophthalmol, 2020, 56: 81-85).

[Influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China]

Objective: To analyze influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China. Methods: We recruited 2 180 participants aged 65 years and older in 8 longevity areas from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey in 2017. Multivariate logistic regression analysis was performed to evaluate the relationships of socio-demographic characteristics, behavioral lifestyle, chronic disease prevalence, functional status, family and social support with depressive symptoms in the elderly. Results: The detection rate of depression symptoms was 15.0% in the elderly aged 65 years and older in 8 longevity areas of China, and the detection rate of depression symptoms was 11.5% in men and 18.5% in women. Multivariate logistic regression analysis results showed that the detection rate of depressive symptoms was lower in the elderly who had regular physical exercises (OR=0.44, 95%CI: 0.26-0.74), frequent fish intakes (OR=0.57, 95%CI: 0.39-0.83), recreational activities (OR=0.65, 95%CI: 0.44-0.96), social activities (OR=0.28, 95%CI: 0.11-0.73) and community services (OR=0.68, 95%CI: 0.50-0.93). The elderly who were lack of sleep (OR=2.04, 95%CI: 1.49-2.80), had visual impairment (OR=1.54, 95%CI: 1.08-2.18), had gastrointestinal ulcer (OR=2.97, 95%CI: 1.53-5.77), had arthritis (OR=2.63, 95%CI: 1.61-4.32), had higher family expenditure than income (OR=1.80, 95%CI: 1.17-2.78) and were in poor economic condition (OR=4.58, 95%CI: 2.48-8.47) had higher detection rate of depressive symptoms. Conclusion: The status of doing physical exercise, fish intake in diet, social activity participation, sleep quality or vision, and the prevalence of gastrointestinal ulcers and arthritis were associated with the detection rate of depressive symptoms in the elderly.

[Analysis of the prevalence of blindness and major blinding diseases in China]

With the growth of the global population and the acceleration of the aging process, the situation of blindness all over the world is increasingly severe. According to the latest data published by the Vision Loss Expert Group in 2017, there were an estimated 36 million blind people worldwide in 2015. The 66(th) World Health Assembly has endorsed the "Universal eye health: a global action plan 2014-2019" , which aims to reduce the prevalence of avoidable visual impairment by 25% by 2019 from the baseline of 2010. As a country with the largest number of blind people in the world, China has an arduous task of preventing and treating eye diseases.This review article summarizes and analyzes the relevant literature on the prevalence of blindness, the main blinding diseases and prevention measures in China, so as to provide reference materials for ophthalmologists to better carry out eye health work and reduce the number of blind people in China. (Chin J Ophthalmol, 2019, 55:625-628).

[Therapeutic effect of rigid permeable contact lenses on irregular astigmatism after keratoplasty]

Objective: To evaluate the clinical effect of rigid permeable contact lenses (RGPCL) in the correction of irregular astigmatism after keratoplasty. Methods: Retrospective case study. From June 2012 to December 2016, 31 patients (37 eyes) who underwent corneal transplantation were tested and fitted with RGPCL. The patients' data of primary disease, interval from keratoplasty to contact lens fitting, uncorrected visual acuity, best spectacle-corrected visual acuity, best RGPCL-corrected visual acuity, contrast visual acuity before and after RGPCL wear, corneal topography and corneal endothelium parameters before and after RGPCL wear were collected, including ocular complications and comfort of contact lenses. Results: Among the 31 patients, 24 were male and 7 were female, with age of (31.3±5.8) years. The mean interval between grafting and initial contact lens fitting was (4.6±2.3) years. Uncorrected visual acuity, best spectacle-corrected visual acuity, and best RGPCL-corrected visual acuity were 0.81±0.21, 0.54±0.13, and 0.10±0.07, respectively (t=7.170, 16.617, 17.866; all P<0.05). The average astigmatism was -5.76±2.23 D and -0.83±0.47 D before and after wearing RGPCL (t=8.531, P<0.05). After wearing RGPCL, the contrast visual acuity of 100%, 25%, 10%, and 5% was increased from 0.95±0.33, 1.18±0.21, 1.40±0.00, and 1.40±0.00 to 0.12±0.15, 0.37±0.17, 0.65±0.25, and 0.96±0.29, respectively (t=5.972, 8.473, 9.243, 5.104; all P<0. 05). There were no obvious changes of corneal endothelium parameters during the observation period. No obvious corneal allograft rejection or other complications occurred, and 94.6% (35/37) of the patients felt comfortable with wearing RGPCL. Conclusions: RGPCL wear is safe and effective in correcting irregular astigmatism after corneal transplantation. We can obtain good corrected vision and improve contrast visual acuity, especially for patients who can not wear spectacles. (Chin J Ophthalmol, 2019, 55: 413-418).

[Association of plasma albumin and hypersensitive C-reactive protein with 5-year all-cause mortality among Chinese older adults aged 65 and older from 8 longevity areas in China]

Objective: To investigate the relationship of plasma albumin and hypersensitive C-reactive protein (Hs-CRP) with 5-year all-cause mortality among Chinese older adults aged 65 and older. Method: Data was collected in 8 longevity areas of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) study conducted by Chinese Center for Disease Control and Prevention and Peking University at baseline survey in 2012 and 2014, the participants enrolled in 2012 was followed-up in 2014 and 2017, the participants enrolled in 2014 was followed-up in 2017 only. Finally, 3 118 older adults aged 65 and older with complete information on albumin, Hs-CRP and body mass index (BMI) were included in this study. Plasma samples of older adults were collected for the detection of albumin and Hs-CRP at baseline survey. Survival status and follow-up time was recorded for all participants. All older adults were divided into 4 groups according to the levels of plasma albumin and Hs-CRP, and Cox proportional hazard models were constructed to assess their influence on the risk of all-cause mortality. Results: Among 3 118 older adults included, the prevalence of hypoalbuminemia was 10.1% (316/3 118), and was 22.8% (711/3 118) for elevated Hs-CRP. During 10 132 person-years of follow-up, 1 212 participants died. Participants with hypoalbuminemia had increased risk of all-cause mortality, with an hazard ratio (HR) and 95% confidential interval (CI) of 1.18 (1.01-1.38), compared to participants with normal plasma albuminemia; participants with elevated Hs-CRP had increased risk of all-cause mortality, with an HR (95%CI) of 1.18 (1.04-1.35), compared to participants with normal plasma Hs-CRP. Participants with normal plasma albumin and elevated Hs-CRP, with hypoalbuminemia and normal Hs-CRP, with hypoalbuminemia and elevated Hs-CRP also had increased risk of all-cause mortality when compared to those with normal plasma albumin and normal Hs-CRP, the HR (95%CI) were 1.16 (1.01-1.34), 1.11 (0.91-1.37) and 1.43 (1.11-1.83), respectively. Conclusion: Hypoalbuminemia and elevated Hs-CRP were responsible for increased risk of 5-year all-cause mortality among Chinese older adults from 8 longevity areas.

[Analysis of risk factors for recurrent sudden sensorineural hearing loss]

Objective:To analyze the factors that may affect the recurrence of sudden sensorineural hearing loss (SSNHL).Method:We retrospectively analyzed the data of 665 SSNHL patients admitted to our hospital from January 2006 to December 2016, among which 12 patients were recurrent. The possible factors that may affect the recurrence of SSNHL were analyzed by Logistic regression analysis.Result: Hyperlipidemia might be one of the factors that caused the recurrence of SSNHL (Odds ratio 54.943,P=0.000). History of radiotherapy might be another factor that caused the recurrence of SSNHL (Odds ratio 64.100,P=0.000).Conclusion:Hyperlipidemia and the history of radiotherapy of head and neck might be risk factors for the recurrence of SSNHL.

[Effect of a self-createdquestionnaire to the history collection of patients with vertigo or dizziness]

Objective: To develop a self-designed questionnaire for history collection of patients with vertigo or dizziness, and to analyze its effect to clinical work.Method: An observational study was conducted to collect 69 patients who had undergone vestibular function tests in our department with main complaints of " dizziness and dizziness".Information was extracted from the questionnaires filled by patients themselves and the inpatient medical records wrote by doctors.The differences in ability to reflect clinically important information was investigated between the questionnaire and medical record.Result:Questionnaire is more comprehensive and meticulous for history collection. It is better than inpatient medical documents. It contains character of vertigo, duration, frequency of attack, time of onset, inducing and aggravating factors, relation with position and posture, concomitant symptoms, ear condition, vision, headache, conditions of other systems, consciousness, medication, VAS score of instability, previous history, personal history, family history, and positive results of examinations.It has a better detection rate in terms of vertigo frequency, duration, suspicious otolith or not, and vestibular compensation than that of inpatient medical record (P<0.05).Conclusion: This self-designed questionnaire can help doctors to collect medical history of patients with vertigo or dizziness.It is worthy of clinical promotion as an important supplement for inpatient and outpatient medical records.

[A review on the research progress related to ambient air pollution and depression]

It is reported that depression has caused heavy disease burden across the world, with an possible association between ambient air pollution and depressive symptoms. In this paper, we reviewed relative literature in this field and summarized the research events on association between ambient air pollution and depression, both in China and abroad and found that the results of the existed studies were inconsistent, with most studies showing that there existed a positive correlation between the exposure of air pollution and depression, but few studies showing the negative correlation or no correlation between the two.

[Effects of exogenous brain-derived neurotrophic factor on the morphology and function of cochlea in the animal model of hereditary hearing loss]

Objective:To study the effect of early administration exogenous BDNF on the morphology and function of conditional knockout Cx26 mice cochlea.Method:Conditional knockout Cx26 mice was chosen as animal model, early after birth (P0-P2) exogenous BDNF (rAAV mediated BDNF plasmid, AAV-BDNF) was injected through scala media. Expression of BDNF in the cochlea was observed by western-blot, the growth promoting effect of nerve fibers was detected by IHC; 2 m after injection, the protective effect of BDNF on corti and spiral ganglion cells were detected by resin section; animal hearing were tested by ABR.Result:①Exogenous BDNF could be well expressed in the inner ear; ②Exogenous BDNF has a good effect on the growth of cochlea nerve fiber; ③Exogenous BDNF could protect the morphology of organ of corti; to count the number of spiral ganglion cells, using the density value of top-turn in non-injected ear as the standard unit, the values of middle and basal turn in injected ear were 0.81±0.02, 0.65±0.02, compared with non-injected ears, both statistically significant difference could be found, indicates that exogenous BDNF can effectively improve the number of spiral ganglion cells. ④By calculating the ABR threshold of different frequencies of the injected and non-injected ear, there was no statistical difference between them. Indicates that exogenous BDNF has no effect on improving the function of cochlea.Conclusion:The protective effect of early administration exogenous BDNF was effective in the cochlea and spiral ganglion cells of conditional knockout Cx26 mice, but no protective effect for auditory function.

[The observation of tacrolimus eye drops preventing the early immunological rejection after penetrating keratoplasty for fungal keratitis]

Objective: To observe the early immunological rejection prevention effect of tacrolimus eye drops combined with glucocorticoids on fungal keratitis patients who received penetrating keratoplasty (PKP). Methods: In a retrospective case series study, medical records of fungal keratitis patients who received PKP in Shandong Eye Institute from March 2013 to December 2015 were reviewed. Twenty-six patients (26 eyes) were given tacrolimus eye drops, and 24 patients (24 eyes) were given 1% cyclosporine A eye drops immediately after PKP. Two weeks after PKP, these patients were given low concentration of glucocorticoids if no fungal recurrence was found. Immune rejection, fungal recurrence, intraocular pressure, and drug irritation symptoms were monitored. Data were analyzed by chi-square test and independent t-test. Results: The average follow-up was 7 months (range, 3 to 12 months) postoperatively. The rejection rate was 15.3% in the tacrolimus group and 47.8% in the cyclosporine A group (χ(2)=5.510, P<0.05). One patient in the tacrolimus group and two patients in the cyclosporine A group suffered fungal recurrence. Two patients in the tacrolimus group and four patients in the cyclosporine A group had secondary glaucoma. The intraocular pressure was controlled. Three patients receiving tacrolimus eye drops and 13 patients receiving cyclosporine A eye drops had mild irritation symptoms. Conclusions: Tacrolimus eye drops combined with low concentration of glucocorticoids can prevent the early immunological rejection after PKP for fungalkeratitis effectively and safely. (Chin J Ophthalmol, 2017, 53:305-310).

[Application of percutaneous AngioJet thrombectomy in patients with acute symptomatic portal and superior mesenteric venous thrombosis]

Objective: To evaluate the clinical value of percutaneous AngioJet thrombectomy in treatment of acute symptomatic portal and superior mesenteric venous thrombosis venous thrombosis (PVMVT) . Method: From January 2014 to January 2016, a total of 8 patients in Nanjing First Hospital with PVMVT verified by color Doppler ultrasound and computed tomographic angiography (CTA) were analyzed retrospectively. Under ultrasound guidance , the branch of the right portal vein(PV) was punctured with a micropuncture set and a 4-F infusion catheter was advanced to the superior mesenteric vein(SMV). The venogram demonstrated the thrombosis in the PV/SMV and a 6-F AngioJet Xpeeedior catheter was advanced over the guidewire and positioned in the distal SMV. Percutaneous thrombectomy was performed after a mixture of 250 000 U of urokinase in 100 ml of normal saline for mechanical pulse spray of thrombus in all patients for approximately 15 minutes. 2 patients underwent PTA and stent implantation after the thrombectomy procedure, 1 of them and the others 6 patients received continuous transcatheter infusion of urokinase (500 000 U/d) for 24 or 48 hours until the thrombosis was completely dissolved confirmed by angiography at 24 and 48 hours.After procedure and the thrombolytic therapy was discontinued, removal of the infusion catheter and the sheath from the liver, the transhepatic tract was embolized with coils or gelfoam to reduce the risk of bleeding. The patency rate of PV /SMV was assessed by CTA at 1 and 6 months after the procedure. Patients were discharged with oral anticoagulation regimen for at least 6 months.The following criteria were used in evaluation of thrombolysis: grade Ⅰ<50% thrombus removal; grade Ⅱ 50%~90% thrombus removal, and grade Ⅲ>90% thrombus removal. Results: All 8 patients with PVMVT were treated by AngioJet thrombectomy. Angiography after the thrombectomy procedure showed complete thrombus removal (>90%) was in 3 cases, substantial thrombus removal (50%~90%) in 5 cases. Grade Ⅲ (complete) thrombolysis was achieved in 7 cases and grade Ⅱ (50%~90%) lysis in 1 case post thrombolytic therapy for 24 or 48 hours. 2 patients had underwent PTA and stent implantation. Large volume intraperitoneal hemorrhage was discovered in 1 patient after removal of the catheter and sheath from the liver. The patient restored stability after a blood transfusion.Venous patency was comfirmed in all 8 patients at 1 or 6 months after the treatment. There was no patient with major complications death related to the procedure. Conclusion: Percutaneous AngioJet thrombectomy with adjunctive thrombolytic therapy is an effective and safe treatment modality in patients with acute symptomatic PVMVT.

[Concerns on the diagnosis and treatment of corneal epitheliopathy]

Corneal epitheliopathy is a commonly seen disease in the clinical work. However, due to its complicated causes, there remain misdiagnosis and mistreatment, which would aggravate epithelial keratopathy and induce corneal scars, eventually leading to irreversible visual impairment. In this article, the primary and secondary causes of corneal epithelial lesions are described in detail. The classification, diagnosis and treatment principles of the disease are also presented to arouse more concern about corneal epitheliopathy. (Chin J Ophthalmol, 2017, 53: 161-163).

[Efficacy comparison of interventional treatment by anterograde or retrograde catheterization for acute lower extremity deep venous thrombosis]

Objective: To compare the clinical efficacy differences between anterograde and retrograde catheterization interventional treatment for acute low extremity deep venous thrombosis(DVT). Methods: The clinical data of 217 patients with acute low extremity DVT between January 2009 and December 2014 were analyzed retrospectively. Group A: 67 patients underwent treated with anterograde catheterization interventional treatment. Group B: 150 patients underwent treated with retrograde catheterization interventional treatment. The degree of thrombolysis in different anatomical sites, clinical effective rate, femoral-popliteal vein valve reflux and the incidence of post-thrombotic syndrome(PTS) were all analyzed. Results: There were no statistical differences in the degree of thrombolysis (≥50%) of common iliac vein, external iliac vein and common femoral vein between group A (83.6%, 88.1%, 91.0%)and B (80.7%, 82.0%, 88.0%)(all P>0.05). The degree of thrombolysis (≥50%) of superficial femoral vein in group A(94.0%) was significantly higher than that of group B (75.3%)(P=0.001). There was no significantly difference in the clinical effective rate at discharged between group A (80.6%) and B(76.7%)( P=0.519). During follow-up of 44±15 months, There was no statistical difference in the patency rate of the iliofemoral vein, the valvular regurgitation of patent femoropopliteal vein and the incidence of PTS between group A(70.2%, 25.4%, 35.8%) and B (60.0%, 31.5%, 40.0%)(all P>0.05). The incidence of PTS in patients with iliofemoral vein patency(13.1%) was significantly lower than that in patients with iliofemoral vein occlusion (82.5%)(P<0.01). Conclusions: The anterograde or retrograde catheterization interventional treatment can be used for treating acute low extremity DVT and get comparable clinical effect.The retrograde catheterization does not increase venous valve damage. The recovery of iliofemoral vein lumen patency is the main task in the treatment of DVT and can significantly reduce the incidence of PTS.

[Clinical application and prognostic analysis of interventional treatment for cesarean scar pregnancy]

OBJECTIVE

To analyze the clinical value and prognosis of cesarean scar pregnancy (CSP) treated by uterine artery embolization (UAE).

METHODS

In the study, 492 cases of patients in Nanjing Maternal and Child Health Care Hospital Affiliated to Nanjing Medical University diagnosed as CSP between January 2011 and December 2014 were chosen, of which 283 were of high-risk group and 209 of low-risk group. According to whether to take UAE, the high-risk group was subdivided into high-risk UAE group(UAE+laparoscopic group), 167 cases, and high-risk non UAE group (chemotherapy+laparoscopic group), 116 cases, while the low-risk group was subdivided into low-risk UAE group (UAE+curettage group), 113 cases, and low-risk non UAE group(chemotherapy+curettage group), 96 cases. The differences of the intraoperative bleeding, length of stay, blood beta human chorionic gonadotropin (β-HCG) dropped to normal time, menstruation recovery time and the hospitalization expenses were compared. And multivariate regression analysis was used to predict the recurrence risk of CSP.

RESULTS

The high-risk UAE group was better than the high-risk non UAE group in comparison of intraoperative bleeding [(36.5±14.8) mL vs.(76.5±39.7) mL], length of stay [(5.9±0.9) d vs.(9.6±1.3) d], blood β-HCG dropped to normal time [(17.9±8.7) d vs.(28.7±10.1) d] and menstruation recovery time [(18.1±1.6) d vs.(24.3±1.8) d],while the low-risk UAE group was better than the low-risk non UAE group in comparison of intraoperative bleeding [(93.2±43.3) mL vs.(284.8±110.5) mL], length of stay [(10.2±1.4) d vs. (30.7±9.6) d], blood β-HCG dropped to normal time [(50.1±17.6)d vs.(67.5±22.9)d] and menstruation recovery time[(56.3±6.7)d vs.(65.9±9.3) d], all P<0.05. The high-risk UAE group was higher than the high-risk non UAE group in comparison of hospitalization expenses [(20 140±1 520 )Yuan vs.(13 510±1 013) Yuan], and the low-risk group UAE was also higher than the low-risk non UAE group in comparison of hospitalization expenses [(10 095±962 )Yuan vs.(3 890±457) Yuan], all P<0.01. Multivariate Logistic regression analysis showed that the treatment method was independent predictor of CSP recurrence risk (OR 2.407, 95%CI 1.176-5.092, P<0.05), and using the comprehensive treatment including UAE could reduce the risk of recurrent CSP.

CONCLUSION

As the efficacy of interventional therapy for CSP was rapid and reliable, fewer complications, faster recovery and lower recurrence, hospitalization with good conditions, and particularly for those patients with CSP who want to fertility again, the comprehensive treatment including UAE treatment should be the first choice.

[Study of ultrasonographic features in predicting reginal lymph node metastasis in patients with papillary thyroid carcinoma]

OBJECTIVE

To demonstrate the ultrasonographic features of papillary thyroid carcinoma (PTC) in predicting associated cervical lymph nodes metastasis (LNM).

METHODS

A total of 136 patients diagnosed with PTC in Beijing Tongren Hospital between January 2014 and September 2014 were enrolled.Of 136 cases, forty patients were confirmed with cervical lymph node metastasis.Seven were males, 33 were females, aged from 18 to 65 years old, mean age was (39.6±10.3) years .The remaining 96 were reported without lymph node metastasis.Twenty-one were males, 75 were females, aged from 23 to 86 years old, mean age was (47.7±12.8) years.Medical record was reviewed for demographic characteristics and pathological findings.The ultrasonographic features of each case were evaluated retrospectively.The difference of ultrasonographic features between the patients with and without LNM was examined.

RESULTS

There were 178 PTCs confirmed with pathology, 159 lesions (89.3%) were detected by ultrasonography, the remaining 19 lesions (10.7%) were under-detected.Of 136 patients with PTC, 40 cases (40/136, 29.4%) were confirmed with cervical LNM, while the remaining 96 cases (96/136, 70.6%) were determined without cervical LNM.PTC with cervical LNM was more frequently seen in the patients who were younger (P=0.000 5) and presenting with multifocal tumors (P=0.014 6). Ultrasonographic features of PTC which significantly associated with LNM were ill-defined margins (P=0.018), solid appearance (P=0.003), and presence of calcification (P=0.000). Of 40 cases with LNM, central cervical LNM was seen in 32 cases (80%), 72.5% of whom appeared as unilateral distribution.

CONCLUSIONS

Patients diagnosed with PTC with younger age and identified with multiple foci of tumors at the time of diagnosis are in an increased risk of associated cervical LNM.Ultrasonographic features of ill-defined margins, solid appearance and calcification in PTC are significant predictors of LNM.

[Focus on the clinical application of the first artificial bioengineered cornea in China]

Corneal disease ranks second among blinding diseases in China, with the corneal blindness taking up one fourth of the blind population. It has a high incidence and a low rate of sight rehabilitation. The lack of cornea donors and the shortage of corneal specialists have become the bottleneck that hampers the development in curing corneal disease. It is of primal importance to find sufficient donor sources in order to alleviate the current situation. In 2015, the world's first artificial bioengineered cornea was approved by CFDA to be applied clinically as a substitute for human cornea in lamellar keratoplasty. It will not only relieve the cornea donor shortage, but will also spur the training and practices of corneal specialists. The application and clinical trials of such an innovative product will significantly boost fundamental and clinical researches in corneal disease in our country, helping more patients with corneal blindness to recover their sights.

The Drosophila RCC1 homolog, Bj1, regulates nucleocytoplasmic transport and neural differentiation during Drosophila development

The Bj1 gene encodes the Drosophila homolog of RCC1, the guanine-nucleotide exchange factor for RanGTPase. Here, we provide the first phenotypic characterization of a RCC1 homolog in a developmental model system. We identified Bj1 (dRCC1) in a genetic screen to identify mutations that alter central nervous system development. We find that zygotic dRCC1 mutant embryos exhibit specific defects in the development and differentiation of lateral CNS neurons although cell division and the cell cycle appear grossly normal. dRCC1 mutant nerve cords contain abnormally large cells with compartmentalized nuclei and exhibit increased transcription in the lateral CNS. As RCC1 is an important component of the nucleocytoplasmic transport machinery, we find that dRCC1 function is required for nuclear import of nuclear localization signal sequence (NLS)-carrying cargo molecules. Finally, we show that dRCC1 is required for cell proliferation and/or survival during germline, eye and wing development and that dRCC1 appears to facilitate apoptosis.

Programmed stimulation for simulation of atrial tachyarrythmias

Swine have become the preeminent non-human animal model for testing of cardiac assistance devices. Such devices must be robust to perturbations in the EKG; therefore it is expeditious, as part of cardiac assistance device testing, to simulate arrhythmias such as atrial flutter and fibrillation in swine. Methods for producing atrial tachyarrythmias include surgical ablation or crushing of atrial tissue and the administration of drugs. These are dangerous, unreliable and usually irreversible; in varying combinations and degrees. When we applied rapid evenly spaced electrical atrial pacing in swine, the variability of ventricular response was less than expected from the corresponding arrhythmia in man. We will describe efforts to produce reversible atrial tachyarrythmias in swine, using programmed stimulation, with the desired degree of ventricular response variability.

Accumulation of glycosphingolipids in human atherosclerotic plaque and unaffected aorta tissues

We have measured the levels of glycosphingolipids and the activity of glycosphingolipid glycosyltransferases in human aortic intima and media from patients who died of atherosclerosis. The effects of lactosylceramide (LacCer) and glucosylceramide (GlcCer) from plaque intima on smooth muscle cell proliferation were assessed. When the GlcCer data was expressed as (micrograms GlcCer/mg cholesterol and/mg total phospholipid, a 28-fold and 7-fold increase in plaque intima compared to normal intima was observed. Similarly, the level of LacCer was elevated 5-fold and 4-fold, respectively, compared to unaffected intima. The activity of UDP-GlcCer: ceramide beta 1-->4 glucosyltransferase (GlcT-1) was similar in unaffected tissue, fatty streaks, and plaques. However, the activity of UDP-galactose: GlcCer, beta 1-->4 galactosyltransferase (GalT-2) activity was moderately higher in plaque than in unaffected tissue. LacCer, but not GlcCer derived from plaque intima exerted a approximately 2.8-fold increase in the proliferation of human aortic smooth muscle cells grown in tissue culture compared to control presumably due to a marked increase in LacCer molecular species containing C16:0, C22:1, and C24:0 fatty acids in plaque intima compared to control. In sum, our findings provide an interesting and novel pathogenic mechanism of lactosylceramide mediated plaque formation via stimulation of aortic smooth muscle cell proliferation.

Role of lactosylceramide and MAP kinase in the proliferation of proximal tubular cells in human polycystic kidney disease

Polycystic kidney disease (PKD) is a common genetic disease characterized by the proliferation of epithelial cells, formation of cysts, and the progression of renal deficiency. We have investigated a possible role of glycosphingolipids in the proliferation of human kidney cells in this disease. The levels of glucosylceramide and lactosylceramide and the activity of glucosylceramide synthase (GlcT-1) and lactosylceramide synthase (GalT-2) were elevated 2-fold and 3-fold, respectively, in the PKD tissue compared to control. Lactosylceramide, but not glucosylceramide (10 microM) derived from PKD exerted a 4-fold stimulation in the proliferation of these cells. However, at a concentration of 40 microM, lactosylceramide and glucosylceramide both stimulated cell proliferation on the order of 10-fold and 2.5-fold, respectively, as compared to control. This phenomenon may be due to the enrichment of lactosylceramide containing shorter chain fatty acids (C16:0-C18:0). Lactosylceramide, but not glucosylceramide exerted a time-dependent stimulation in the phosphorylation of mitogen-activated protein kinase (p44 MAPK) in normal human kidney proximal tubular cells. Moreover, the kidneys and cultured cells from the PKD patients contained higher levels of the p44 MAPK as compared to normal human kidneys. In sum, our studies indicate that lactosylceramide present in the PKD kidney may stimulate cell proliferation via activation of the p44 MAPK, and contribute to the pathophysiology in this disease.

Studies of the action of ceramide-like substances (D- and L-PDMP) on sphingolipid glycosyltransferases and purified lactosylceramide synthase

We have studied the effects of D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP) and its L-enantiomer on glycosphingolipids in cultured normal human kidney proximal tubular cells. We found that D-PDMP exerted a concentration-dependent reduction in the metabolic labelling and cellular levels of glucosylceramide (GlcCer), lactosylceramide (LacCer), and the globo-series glycosphingolipids, GbOSe3Cer and GbOse4Cer. It also directly inhibited the activity of UDP-glucose:ceramide beta 1--> 4-glucosyltransferase (GlcT-1) and UDP-galactose: GlcCer beta 1-->4 galactosyltransferase (GalT-2). In contrast, L-PDMP had opposite effects on the metabolic labelling of GlcCer, LacCer, and GbOse3Cer. The levels of GlcCer and LacCer were increased, while the labelling and level of GbOse4Cer were strongly reduced. Purified GalT-2 from human kidney was inhibited by D-PDMP and stimulated by L-PDMP. It appears likely that the different glycosphingolipid glycosyltransferases possess similar binding sites for the ceramide moiety, which are blocked by binding to D-PDMP and, in the case of GbOse4Cer synthase, by L-PDMP as well. The stimulatory effects of L-PDMP on GlcCer and LacCer synthases may be the result of binding to a modulatory site on the glycosyltransferases; in intact cells, the enzyme-analog complex may afford protection against the normal catabolic inactivation of the enzymes.

Digalactosylceramide is the receptor for staphylococcal enterotoxin-B in human kidney proximal tubular cells

We have characterized a glycosphingolipid (GSL) receptor for Staphylococcus enterotoxin-B (SEB) in cultured human kidney proximal tubular (PT) cells. Solid-phase binding of [125I]SEB to the GSL receptor was concentration dependent and was not displaceable by two structurally related toxins, such as staphylococcal enterotoxin-A and toxic shock syndrome toxin-1. Rat kidney cells did not bind [125I]SEB. However, when the rat kidney cells were pre-incubated with digalactosylceramide, there was a concentration-dependent binding of [125I]SEB. Trimethylsilyl derivatization of methyl glycosides, followed by gas-liquid chromatography-mass spectrometry (GC-MS), revealed that galactose was the major sugar component of this putative receptor GSL. The sphingosines present in this GSL were d18:2, d22:2 and d23:0; the fatty acids present were palmitate, oleate and stearate. Permethylation of alditol acetates and GC-MS revealed two predominant sugars, namely 2, 3, 4 and 6 tetramethylgalactital and 2, 3 and 6 trimethylgalactital. The GSL receptor for SEB was sensitive to alpha-galactosidase, and resistant to beta-galactosidase and beta-glucosidase. Taken together, our studies reveal that the tentative structure of the receptor for SEB in human kidney PT cells is CerGal alpha 1-->4Gal. In summary, we have identified a GSL as one of the binding sites of SEB, a food-borne toxin. We believe that our finding may open up rational approaches for the therapy of SEB-induced glycopathology in man.

[Reactivation of latent virus in corneas of quiescent recurrent herpes simplex keratitis (HSK)]

By immunohistochemical staining, all 20 corneal half-buttons of HSK quiescent for 4-60 months obtained from 20 cases undergoing penetrating keratoplasties were found negative of HSV-1 antigen. The other 20 corneal half-buttons were cultured for 3-4 weeks and 18 of them (90%) were found HSV-1 antigen positive. The 20 reactivated corneal half-buttons were co-cultured for 1 week with primary rabbit kidney (RK) cells and cellular pathological lesions appeared in the RK cells in 3 cultures which were also HSV-1 antigen positive. These results demonstrated that the latent virus might have been harbored in the corneal cells to escape immunohistochemical detection. In the view point of immunopathology and virology, penetrating keratoplasy can be performed on patients with HSK quiescent over 3 months.