An efficient computational method for predicting drug-target interactions using weighted extreme learning machine and speed up robot features.

BACKGROUND: Prediction of novel Drug-Target interactions (DTIs) plays an important role in discovering new drug candidates and finding new proteins to target. In consideration of the time-consuming and expensive of experimental methods. Therefore, it is a challenging task that how to develop efficient computational approaches for the accurate predicting potential associations between drug and target. RESULTS: In the paper, we proposed a novel computational method called WELM-SURF based on drug fingerprints and protein evolutionary information for identifying DTIs. More specifically, for exploiting protein sequence feature, Position Specific Scoring Matrix (PSSM) is applied to capturing protein evolutionary information and Speed up robot features (SURF) is employed to extract sequence key feature from PSSM. For drug fingerprints, the chemical structure of molecular substructure fingerprints was used to represent drug as feature vector. Take account of the advantage that the Weighted Extreme Learning Machine (WELM) has short training time, good generalization ability, and most importantly ability to efficiently execute classification by optimizing the loss function of weight matrix. Therefore, the WELM classifier is used to carry out classification based on extracted features for predicting DTIs. The performance of the WELM-SURF model was evaluated by experimental validations on enzyme, ion channel, GPCRs and nuclear receptor datasets by using fivefold cross-validation test. The WELM-SURF obtained average accuracies of 93.54, 90.58, 85.43 and 77.45% on enzyme, ion channels, GPCRs and nuclear receptor dataset respectively. We also compared our performance with the Extreme Learning Machine (ELM), the state-of-the-art Support Vector Machine (SVM) on enzyme and ion channels dataset and other exiting methods on four datasets. By comparing with experimental results, the performance of WELM-SURF is significantly better than that of ELM, SVM and other previous methods in the domain. CONCLUSION: The results demonstrated that the proposed WELM-SURF model is competent for predicting DTIs with high accuracy and robustness. It is anticipated that the WELM-SURF method is a useful computational tool to facilitate widely bioinformatics studies related to DTIs prediction.

Minimally invasive maxillary sinus augmentation with simultaneous implantation on an elderly patient: A case report.

BACKGROUND: In this case study, a minimally invasive transalveolar approach using platelet-rich fibrin and bone substitute with simultaneous implantation was carried out in an elderly patient. We analyzed the cone-beam computed tomography (CBCT) findings to evaluate bone regeneration. CASE SUMMARY: A 65-year-old female with no contraindications for dental implants and loss of maxillary bilateral molars is described. Examination by CBCT showed the available vertical bone height in the bilateral posterior maxilla was 0.5-6.8 mm in the left and 2.8-6.5 mm in the right. The patient underwent a transalveolar approach using platelet-rich fibrin and bone substitute with simulataneous placement of an implant 10 mm in length. Six months post-surgery, the implant showed excellent osseointegration with the bone graft. Thereafter, full-ceramic crowns were fitted. Follow-up at 2 years demonstrated satisfactory prognosis. CONCLUSION: Platelet-rich fibrin and bone substitute can be used to augment the maxillary sinus with a vertical bone height less than 4 mm.

Differential expression of microRNA-411 and 376c is associated with hypertension in pregnancy.

Preeclampsia is a major reason of morbidity and mortality in pregnant women and perinatal fetus. Hence, it is of prime importance that diagnostic markers are defined to predict chances of preeclampsia in pregnant women. It has been previously shown that microRNA (miRNA)-376c expression is decreased in the placenta of preeclampsia patients at term. Even though this decrease was not mimicked in the placenta at the pre-term stage, miR-376c expression was decreased in the plasma of these patients as early as the second trimester. Plasma and placenta specimens were obtained from pregnant women having unifetal gestation undergoing perinatal care between January 2014 and December 2016 (n=49). Early trimester placentas were collected from patients undergoing terminated pregnancies through dilation and curettage procedure. Our results showed that in addition to miR-376c, miR-441 levels were decreased in the placenta of preeclampsia patients, and this decrease occurred both at pre-term and at term. This decrease is also mimicked in the plasma levels at both early and late weeks of pregnancy, highlighting that miR-441 levels can serve as a diagnostic marker of risk of preeclampsia in pregnant women. Overexpression of the miR-441, as well as miR-376c, promoted cell viability, migration, and invasion in the human immortalized cytotrophoblast cell line HTR8/SVneo, indicating that their decrease in pregnant women would result in anomalous apoptosis and functional imbalance resulting in premature abortion and other complications. MiR-441 level can thus potentially serve as diagnostic marker of preeclampsia in pregnant women.

Differential expression of microRNA-411 and 376c is associated with hypertension in pregnancy

Preeclampsia is a major reason of morbidity and mortality in pregnant women and perinatal fetus. Hence, it is of prime importance that diagnostic markers are defined to predict chances of preeclampsia in pregnant women. It has been previously shown that microRNA (miRNA)-376c expression is decreased in the placenta of preeclampsia patients at term. Even though this decrease was not mimicked in the placenta at the pre-term stage, miR-376c expression was decreased in the plasma of these patients as early as the second trimester. Plasma and placenta specimens were obtained from pregnant women having unifetal gestation undergoing perinatal care between January 2014 and December 2016 (n=49). Early trimester placentas were collected from patients undergoing terminated pregnancies through dilation and curettage procedure. Our results showed that in addition to miR-376c, miR-441 levels were decreased in the placenta of preeclampsia patients, and this decrease occurred both at pre-term and at term. This decrease is also mimicked in the plasma levels at both early and late weeks of pregnancy, highlighting that miR-441 levels can serve as a diagnostic marker of risk of preeclampsia in pregnant women. Overexpression of the miR-441, as well as miR-376c, promoted cell viability, migration, and invasion in the human immortalized cytotrophoblast cell line HTR8/SVneo, indicating that their decrease in pregnant women would result in anomalous apoptosis and functional imbalance resulting in premature abortion and other complications. MiR-441 level can thus potentially serve as diagnostic marker of preeclampsia in pregnant women.

Prediction of Drug-Target Interaction Networks from the Integration of Protein Sequences and Drug Chemical Structures.

Knowledge of drug-target interaction (DTI) plays an important role in discovering new drug candidates. Unfortunately, there are unavoidable shortcomings; including the time-consuming and expensive nature of the experimental method to predict DTI. Therefore, it motivates us to develop an effective computational method to predict DTI based on protein sequence. In the paper, we proposed a novel computational approach based on protein sequence, namely PDTPS (Predicting Drug Targets with Protein Sequence) to predict DTI. The PDTPS method combines Bi-gram probabilities (BIGP), Position Specific Scoring Matrix (PSSM), and Principal Component Analysis (PCA) with Relevance Vector Machine (RVM). In order to evaluate the prediction capacity of the PDTPS, the experiment was carried out on enzyme, ion channel, GPCR, and nuclear receptor datasets by using five-fold cross-validation tests. The proposed PDTPS method achieved average accuracy of 97.73%, 93.12%, 86.78%, and 87.78% on enzyme, ion channel, GPCR and nuclear receptor datasets, respectively. The experimental results showed that our method has good prediction performance. Furthermore, in order to further evaluate the prediction performance of the proposed PDTPS method, we compared it with the state-of-the-art support vector machine (SVM) classifier on enzyme and ion channel datasets, and other exiting methods on four datasets. The promising comparison results further demonstrate that the efficiency and robust of the proposed PDTPS method. This makes it a useful tool and suitable for predicting DTI, as well as other bioinformatics tasks.

Improving protein-protein interactions prediction accuracy using protein evolutionary information and relevance vector machine model.

Predicting protein-protein interactions (PPIs) is a challenging task and essential to construct the protein interaction networks, which is important for facilitating our understanding of the mechanisms of biological systems. Although a number of high-throughput technologies have been proposed to predict PPIs, there are unavoidable shortcomings, including high cost, time intensity, and inherently high false positive rates. For these reasons, many computational methods have been proposed for predicting PPIs. However, the problem is still far from being solved. In this article, we propose a novel computational method called RVM-BiGP that combines the relevance vector machine (RVM) model and Bi-gram Probabilities (BiGP) for PPIs detection from protein sequences. The major improvement includes (1) Protein sequences are represented using the Bi-gram probabilities (BiGP) feature representation on a Position Specific Scoring Matrix (PSSM), in which the protein evolutionary information is contained; (2) For reducing the influence of noise, the Principal Component Analysis (PCA) method is used to reduce the dimension of BiGP vector; (3) The powerful and robust Relevance Vector Machine (RVM) algorithm is used for classification. Five-fold cross-validation experiments executed on yeast and Helicobacter pylori datasets, which achieved very high accuracies of 94.57 and 90.57%, respectively. Experimental results are significantly better than previous methods. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on the yeast dataset. The experimental results demonstrate that our RVM-BiGP method is significantly better than the SVM-based method. In addition, we achieved 97.15% accuracy on imbalance yeast dataset, which is higher than that of balance yeast dataset. The promising experimental results show the efficiency and robust of the proposed method, which can be an automatic decision support tool for future proteomics research. For facilitating extensive studies for future proteomics research, we developed a freely available web server called RVM-BiGP-PPIs in Hypertext Preprocessor (PHP) for predicting PPIs. The web server including source code and the datasets are available at http://219.219.62.123:8888/BiGP/.

Using the Relevance Vector Machine Model Combined with Local Phase Quantization to Predict Protein-Protein Interactions from Protein Sequences.

We propose a novel computational method known as RVM-LPQ that combines the Relevance Vector Machine (RVM) model and Local Phase Quantization (LPQ) to predict PPIs from protein sequences. The main improvements are the results of representing protein sequences using the LPQ feature representation on a Position Specific Scoring Matrix (PSSM), reducing the influence of noise using a Principal Component Analysis (PCA), and using a Relevance Vector Machine (RVM) based classifier. We perform 5-fold cross-validation experiments on Yeast and Human datasets, and we achieve very high accuracies of 92.65% and 97.62%, respectively, which is significantly better than previous works. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on the Yeast dataset. The experimental results demonstrate that our RVM-LPQ method is obviously better than the SVM-based method. The promising experimental results show the efficiency and simplicity of the proposed method, which can be an automatic decision support tool for future proteomics research.

Diagnosis of pupillary block glaucoma after removal of congenital cataracts with intraoperative ultrasound biomicroscopy: a case report.

BACKGROUND: Aphakic glaucoma is a common complication after congenital cataract extraction, especially in those who have surgery during infancy. This case report describes a case of bilateral pupillary block glaucoma diagnosed with intraoperative ultrasound biomicroscopy (UBM) after removal of congenital cataract. CASE PRESENTATION: We present a case report of a 9-month-old infant with bilateral corneal enlargement and ocular hypertension after uneventful removal of congenital cataracts. Initial and follow-up examination findings were reviewed. The infant was suspected to have developmental glaucoma and schemed to have bilateral trabeculotomy until pupillary obstruction by vitreous herniation and angle closure with iris bombé were detected by intraoperative UBM. Anterior vitrectomy and goniosynechialysis were then performed as treatment. CONCLUSION: Pupillary block glaucoma is a rare type of infantile aphakic glaucoma. Application of intraoperative UBM can assist in the differential diagnosis of aphakic glaucoma in infants.

RVMAB: Using the Relevance Vector Machine Model Combined with Average Blocks to Predict the Interactions of Proteins from Protein Sequences.

Protein-Protein Interactions (PPIs) play essential roles in most cellular processes. Knowledge of PPIs is becoming increasingly more important, which has prompted the development of technologies that are capable of discovering large-scale PPIs. Although many high-throughput biological technologies have been proposed to detect PPIs, there are unavoidable shortcomings, including cost, time intensity, and inherently high false positive and false negative rates. For the sake of these reasons, in silico methods are attracting much attention due to their good performances in predicting PPIs. In this paper, we propose a novel computational method known as RVM-AB that combines the Relevance Vector Machine (RVM) model and Average Blocks (AB) to predict PPIs from protein sequences. The main improvements are the results of representing protein sequences using the AB feature representation on a Position Specific Scoring Matrix (PSSM), reducing the influence of noise using a Principal Component Analysis (PCA), and using a Relevance Vector Machine (RVM) based classifier. We performed five-fold cross-validation experiments on yeast and Helicobacter pylori datasets, and achieved very high accuracies of 92.98% and 95.58% respectively, which is significantly better than previous works. In addition, we also obtained good prediction accuracies of 88.31%, 89.46%, 91.08%, 91.55%, and 94.81% on other five independent datasets C. elegans, M. musculus, H. sapiens, H. pylori, and E. coli for cross-species prediction. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on the yeast dataset. The experimental results demonstrate that our RVM-AB method is obviously better than the SVM-based method. The promising experimental results show the efficiency and simplicity of the proposed method, which can be an automatic decision support tool. To facilitate extensive studies for future proteomics research, we developed a freely available web server called RVMAB-PPI in Hypertext Preprocessor (PHP) for predicting PPIs. The web server including source code and the datasets are available at http://219.219.62.123:8888/ppi_ab/.

[Study on changes of intraocular pressure within 24 hours in primary open angle glaucoma and normal eyes].

OBJECTIVE: To analyze the discipline of intraocular pressure (IOP) variation, through circadian intraocular pressure monitoring in primary open-angle glaucoma (POAG) patients and normal controls, with a view to provide basis for individualized treatment of glaucoma. METHODS: Subjects were enrolled from the outpatients of Shanghai Beizhan Hospital and Eye and ENT Hospital of Fudan University, which were diagnosed as primary open angle glaucoma, from April 2006 to April 2009. Totally there were 102 cases of patients and 83 cases of normal volunteers. All the subjects accepted 24-hour IOP measurements using non-contact tonometer every two hours starting from 8:00 am. And the IOP between 00:00 to 06:00 am was measured in sitting position immediately after wake up. RESULTS: The differences of peak IOP [(16.0 ± 2.7) mm Hg of right eye and (16.2 ± 2.7) mm Hg of left eye in normal group; (25.3 ± 5.6) mm Hg of right eye and (24.8 ± 5.1) mm Hg of left eye in POAG group], valley IOP (11.1 ± 2.5) mm Hg of right eye and (11.0 ± 2.3) mm Hg of left eye in normal group; (16.3 ± 3.7) mm Hg of right eye and (16.2 ± 3.3) mm Hg of left eye in POAG group, average IOP (13.4 ± 2.5) mm Hg of right eye and (13.4 ± 2.5) mm Hg of left eye in normal group; (19.9 ± 4.3) mm Hg of right eye and (19.8 ± 3.8) mm Hg of left eye in POAG group), and IOP fluctuations (5.0 ± 1.6) mm Hg of right eye and (5.2 ± 1.7) mm Hg of left eye in normal group; (9.1 ± 3.6) mm Hg of right eye and (8.6 ± 3.8) mm Hg of left eye in POAG group between two groups were all of statistically significance (P < 0.01). Notably, the peak IOP of 59.6% in normal control group and 73.5% in POAG group were outside working hours, especially in the time period from 00:00 to 06:00 am. The peak value of 50% in normal group and 64.7% in POAG group located between 00:00 to 06:00 in the morning. CONCLUSIONS: By comparison and analysis, 24-hour intraocular pressure measurement could provide us pre-treatment basic state, so as to provide detailed information for individualized treatment. If possible, it is suggested that 24-hour IOP monitoring should be added as a routine examination of primary open angle glaucoma.

[Comparative study of harvesting of radial artery and great saphenous vein in patients aged 65 years and older with coronary heart disease].

OBJECTIVE: To investigate the difference between autologous radial artery (RA) and great saphenous vein (GSV) harvesting in the elderly aged 65 years and older in coronary artery bypass grafting. METHODS: 171 patients aged 65 years and older underwent CABG with left internal mammary artery (LIMA), RA and GSV harvesting between January 2004 and June 2008. The harvesting time, length of conduits, intraoperative graft flow and harvest-site complications between RA and GSV was observed and follow-up was performed. RESULTS: A total of 171 RA and 171 GSV grafts were collected. The mean number of distal anastomoses was 3.20 +/- 0. 35. There was no significant difference in harvesting time, length of conduits and intraoperative graft flow between RA and GSV (29 +/- 10 min vs. 28 +/- 8 min, 18.2 cm +/- 1.5 cm vs. 21.3 cm +/- 5.7 cm and 41 ml/min +/- 19 ml/min vs. 34 ml/min +/- 9 m/min, P > 0.05), however, postoperatively,the length of wound healing and the incidence of infection, hematoma, exudation, paresthesia and tumescence of wound in RA was obviously lower than those in GSV (P < 0.05). CONCLUSIONS: Harvesting of RA in the elderly aged 65 years and older was superior to that of SVG and RA might play an more important role in CABG in the elderly.

[Trabeculotomy on primary congenital glaucoma: a retrospective study of 164 cases (257 eyes)].

OBJECTIVE: To study the relationship of long-term effect of trabeculotomy on primary congenital glaucoma and the related risk factors. METHOD: 164 consecutive patients with primary congenital glaucoma (257 eyes), underwent initial surgery of trabeculotomy between 1996 and 2007. Follow-up was conducted for 30.9 (8.6 - 58.3) months, with a follow-up rate of 89.02%. Multivariate analysis by Logistic regression was conducted to analyze the relation of the factors including age of onset, time between onset and operation, preoperative intraocular pressure, clarity of cornea, and corneal diameter to the failure of surgery. Cox proportional hazards regression modeling was used to analyze the factors related to success of surgery. RESULT: Multivariate logistic regression showed that the preoperative intraocular pressure (IOP) and clarity of cornea were independent risk factors for final outcome (OR(IOP) = 1.408, P = 0.047, and OR(CLA) = 1.691, P = 0.019). Cox regression showed that clarity of cornea was the factor related to the surgery success time (OR(CLA) = 1.632, P = 0.008). CONCLUSION: Clarity of cornea reflexes the condition of primary congenital glaucoma more stably than IOP. It is possible to prognosticate the surgical outcome to combine the clarity of cornea with the IOP value before operation.

[Clinical analysis on sixteen cases of Sturge-Weber syndrome-associated glaucoma].

OBJECTIVE: To investigate the clinical features of Sturge-Weber syndrome-associated glaucoma and its surgical treatment. METHODS: A retrospective case series study. The general clinical data and related ocular manifestations in 16 patients (21 eyes) with Sturge-Weber syndrome-associated glaucoma in our hospital from January 2003 to December 2007 were analyzed retrospectively. RESULTS: Age of the patients ranged between 1 month to 31 years old, and the median age was 11 years. Bilateral facial angiomas were present in 8 patients, and two of them had extensive hemangioma. Eleven cases had unilateral glaucoma and 3 of them had bilateral facial angiomas. Five patients had bilateral glaucoma and all of them had bilateral facial angiomas. Open anterior chamber angle was found in all affected eyes by gonioscopy. B-scan ultrasonography was performed in 21 eyes and diffused occupying lesions in the choroid were found in 8 eyes (38.1%). Posterior bowing of the iris, low echo in ciliary body and shallow ciliary body detachment were found by ultrasound biomicroscopy. Anti-glaucoma surgeries including trabeculotomy, trabeculectomy, non-penetrating deep sclerectomy, valve implantation and cyclocryotherapy were performed in 18 eyes. Eighty percent of the eyes which underwent trabeculectomy developed choroidal detachment after operation. Ten patients (11 eyes) were followed-up for 22 months on average. Intraocular pressure was significantly lower than that before the operation (t = 5.3956, P < 0.01). Intraocular pressure in all followed-up eyes was controlled at < or = 21 mm Hg (1 mm Hg = 0.133 kPa). CONCLUSIONS: The clinical features of Sturge-Weber syndrome-associated glaucoma include facial angiomas, open anterior chamber angle and choroidal hemangioma. Anti-glaucoma surgery can reduce the intraocular pressure effectively.

Increased levels of transforming growth factor-betal and -beta2 in the aqueous humor of patients with neovascular glaucoma.

BACKGROUND AND OBJECTIVE: To measure the concentrations of transforming growth factor-betal and beta2 (TGF-beta1 and TGF-beta2) in the aqueous humor of patients with neovascular glaucoma (NVG). PATIENTS AND METHODS: Patients were divided into four groups: NVG secondary to central retinal vein occlusion (group 1), NVG secondary to proliferative diabetic retinopathy (group 2), central retinal vein occlusion without rubeosis (group 3), and senile cataract (group 4). The total TGF-beta 1 and TGF-beta2 concentrations in the aqueous humor of the four groups were measured by enzyme linked immunosorbent assay. RESULTS: The mean concentrations of total TGF-betal were 600.7 +/-436.7 microg/mL in group 1, 802.0 +/-359.5 pg/mL in group 2, and undetectable in groups 3 and group 4 (P < .05). The mean concentrations of total TGF-beta2 were 6,307.9+/- 2,206.2 microg/mL in group 1, 5,908.0+/-2,033.2 microg/mL in group 2, 899.7+/- 425.6 microg/mL in group 3, and 385.7 +/-89.9 microg/mL in group 4. The total TGF-betal and TGF-beta2 concentrations in groups 1 and 2 were significantly higher than those in groups 3 and 4, whereas the total TGF-beta2 concentration in group 3 was significantly higher than that in group 4 (P < .05). There was no significant difference in the TGF-betal or TGF-beta2 concentrations between groups 1 and 2 (P> .05). CONCLUSIONS: The abnormally high concentrations of TGF-betal and TGF-beta2 in the aqueous humor of patients with NVG may explain some aspects of the pathogenesis of NVG and the high failure rate of filtering operations in NVG.

[Pathological study on the deep scleral flap and external trabecular membrane obtained from non-penetrating trabecular surgery].

OBJECTIVE: To study the anatomic background of non-penetrating trabecular surgery (NPTS) and to explore the resistant site of aqueous outflow in primary open-angle glaucoma. METHODS: NPTS was performed in 18 eyes of 12 cases (10 males, 2 females) with POAG. The age of these patients ranged from 42 to 65 years old. The deep scleral flap and external trabecular membrane were obtained during the surgical procedure and were examined by light microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). RESULTS: The beginning part of the collection canal in the outer wall of the Schlemm's canal were very narrow, and there was electron dense material (so-called plaques) around the outer wall of the Schlemm's canal. The external trabecular membrane consisted of adjacent trabecular meshwork and part of the corneoscleral trabecular meshwork. The number of the trabecular cells was decreased and a large amount of electron dense materials were deposited in the adjacent trabecular meshwork. The holes of the corneoscleral trabecular meshwork was small and irregular. In the corneoscleral trabecular meshwork, the trabecular lamellae was thicken, the amount of elastic-like fibers was increased and the trabecular cells, especially the nucleus, were enlarged. In the advanced stage of POAG, a great amount of electron dense material was deposited in the corneoscleral trabecular meshwork and the inter-trabecular spaces was blocked. CONCLUSIONS: The deep scleral flap of NPTS contains the outer wall of Schlemm's canal and the external trabecular membrane, which consists of the inner wall of the Schlemm's canal, the adjacent trabecular meshwork and part of the corneoscleral trabecular meshwork. The main resistant site of aqueous outflow in POAG lies in the adjacent trabecular meshwork and in part of the corneoscleral trabecular meshwork. The outer wall of the Schlemm's canal is another important resistant site for aqueous outflow.

Relationship between differences of gene expression in early developing seeds of hybrid versus parents and heterosis in wheat.

In order to understand molecular basis of heterosis, mRNA differential display was used to analyze the differences in gene expression between seeds of 18 reciprocal hybrids and their 6 parents at 6th day after pollination. The relationship between gene expression patterns and heterosis was determined. Only bands that can be repeated in duplicate PCR were used for analysis so as to reduce false positive bands. Among the total of 2,025 bands displayed, 1,386 bands (68.43%) were reproducible. Eight patterns (fifteen kinds) of gene expression were observed, which include: (1) bands occurring in only one parent (two kinds); (2) bands observed in both hybrids and one parent (two kinds); (3) bands detected in parents and one hybrid (two kinds); (4) bands displayed in only one hybrid (two kinds); (5) bands revealed in one hybrid and its corresponding female (two kinds) or male (two kinds) parent; (6) bands visualized in only both hybrids (one kind); (7) bands occurring in only parents (one kind); (8) bands observed in parents and both hybrids (one kind). Our results indicate that differences of gene expression between hybrids and their parents are very obvious. The percentages of bands observed in only both hybrids and in only both parents are lower. The analysis shows that bands observed in parents and both hybrids are not correlated with all nine agronomic traits, which indicates differentially expressed genes are mainly responsible for the observed heterosis. At least one pattern of differential gene expression is significantly correlated with nine agronomic traits. Silenced bands in hybrid (which include bands occurring in only one parent, bands detected in both parents and one hybrid and bands in only parents) and bands present in one hybrid and its corresponding female or male parent are likely to play important roles in heterosis. These results suggest that early seed development could be closely related to heterosis.

[The failure causes of non-penetrating trabecular surgery and reoperation].

OBJECTIVE: To study the failure causes of non-penetrating trabecular surgery (NPTS) with SKGeL (a hyaluronic acid biological gel) implant and the surgical method of reoperation. METHODS: Repeated operation with mitomycin (MMC) through the initial surgical site was performed on 13 failure cases (13 eyes) that had undergone NPTS with SKGeL implant. The blockage of filtration tract was removed and the anterior chamber was intact during the surgery. All of these cases were open-angle glaucoma. Before the repeated surgery ultrasound biomicroscopic (UBM) examination was performed on the primary filtering bleb, and the intraocular pressure (IOP) examination was followed after the repeated operation. RESULTS: The mean follow-up period was (14.0 +/- 5.8) months (6 to 24 months). The examination of UBM showed that the filtering bleb disappeared and there was a liquid chamber under the superficial scleral flap in every failure case. The filtration failure due to the scarring at conjunctiva-Tenon's capsule-superficial scleral flap interface in 9 cases, proliferative membrane formation on the trabecular surface in 3 cases, micro-penetration of the trabecula in 1 case. At the end of follow-up, the IOP of 10 cases was lower than 21 mmHg without medication, the mean IOP level was (14.1 +/- 3.7) mm Hg, the IOP of 1 cases was 15 mmHg with Betagen, another 2 cases failed again 6 months after the repeated surgery and underwent the trabeculectomy at last. The complications included hyphema in one case and micro-penetration of the tabecula in one case. CONCLUSIONS: The scarring at conjunctiva-Tenon's capsule-superficial scleral flap interface was the most important cause of NPTS with SKGeL implant failure. A repeated surgery with MMC through the initial surgical site may be a choice for the failure cases.