Preliminary study of retinal pathological features in preterm birth pups exposed to an animal model of oxygen-induced retinopathy in mice.

BACKGROUND: The main risk factors of retinopathy of prematurity (ROP) are low gestational age and low birth weight, which are mainly caused by preterm birth. Currently, the animal model of oxygen-induced retinopathy (OIR) in mice is the most widely used model in ROP-associated studies. However, the experimental mice are normal-term pups, and may not mimic the pathogenic status of human ROP patients. In this study, we investigated the retinal pathological features in preterm birth pups exposed to an animal model of oxygen-induced retinopathy in mice. METHODS: Preterm-birth mice were obtained from pregnant C57BL/6J mice that were induced by an intraperitoneal injection of lipopolysaccharide (LPS). The preterm and control mice were treated with high oxygen (75%) from postnatal day 7 (P7) to P12. The mice were perfused with high-molecular-weight FITC-dextran on P12, P15 and P17, and the retinas were whole-mounted and imaged. Vascular endothelial growth factor (VEGF) mRNA was also detected. Cross-sections of the retina were stained with hematoxylin and eosin (H&E) to identify preretinal neovascular tufts. For general observation, whole retinal images were also obtained using a microscope. RESULTS: Leakage of the retinal blood vessels was aggravated in the preterm mice, particularly on P12 and P15. The non-perfused areas of the retina (pixel value, 183,673 ± 28,148 vs 132,110 ± 23,732, P = 0.009) and the number of preretinal endothelial cell nuclei were smaller (30.17 ± 8.33 vs 22.17 ± 6.74, P < 0.0001) on P17. The VEGF mRNA levels in the retinas were higher on P12 and P15 but lower on P17, compared with the control mice. Retinal hemorrhage was observed in the preterm mouse group (five out of six examined eyes). CONCLUSIONS: Preterm-birth mice that were subject to OIR exhibited several pathological features, such as retinal hemorrhage, severe retinal leakage and moderate retinal neovascularization, which were similar to the clinical manifestations in ROP patients.

[Effect of premature birth on retinal vascular development in the neonatal rat].

OBJECTIVE: To study the effects of premature birth on the development of rat retinal vasculature. METHODS: Experimental study. Sixty pregnant Sprague-Dawley rats were divided into four groups: bacterial lipopolysaccharide-induced preterm group (LPS group), RU-486 induced preterm group (RP group), cesarean section induced preterm group (CP group), and the normal delivery rats as the control group. The weight of rats from each group was recorded until postnatal day 21. On postnatal day 4, 7, 10 and 14 (P4, P7, P10 and P14), the retina of right eye was dissected and whole-mounted. Each premature group was divided into two subgroups based on the number of rats in each litter, the small subgroup (6-8 rats per litter, group 1) and the large subgroup (14-18 rats per litter, group 2). The development of retinal vascularization process was observed on P4, P7 and P10 (n = 6).Independent t test, one-way ANOVA and LSD-t test were used to analyzed the results. RESULTS: The weight of premature rats in LPS, CP and RP groups was significantly lower than that in the normal group within postnatal 21 days (LSD-t test: all P < 0.05). On the P4 and P7 in LPS group, the proportions of retinal superficial vascularized area of newborn rats [(0.47 ± 0.02) % ,(0.63 ± 0.04)%] were less than that in the normal group [(0.57 ± 0.04) % , (0.74 ± 0.05)%] (t4 d = 6.427, P 4 d = 0.000;t7 d = 5.111, P 7 d = 0.000). On the P4 and P7 in RP group, this proportions [(0.49 ± 0.04) %,(0.65 ± 0.04)%] were less than that in the normal group [(0.57 ± 0.04) %, (0.74 ± 0.05)%] (t4 d = 4.469, P 4 d = 0.000;t7 d = 2.491, P 7 d = 0.022). On P4, P7 and P10 in CP group, this proportions [(0.49 ± 0.05) %, (0.61 ± 0.05) %, (0.94 ± 0.03)%] were also less than that in the normal group[ (0.57 ± 0.04) %, (0.74 ± 0.05) %, (0.97 ± 0.02)%] (t4 d = 4.044, P 4 d = 0.001;t7 d = 6.011, P 7 d = 0.000; t 10 d = 2.331, P 10 d = 0.030). Retinal superficial vascularization completed on P14 in all groups. On the P4 and P7 in LPS group, the proportion of retinal vascularized area of group 2 [(0.44 ± 0.02)%, (0.60 ± 0.03)%] were less than that of group 1 [(0.53 ± 0.04)%, (0.74 ± 0.03)%] (t4 d = 3.852, P 4 d = 0.008; t7 d = 5.630, P 7 d = 0.001). On the P4 and P7 in CP group, this proportion in group 2 [(0.43 ± 0.02)%, (0.64 ± 0.03)%] were less than that of group 1 [ (0.54 ± 0.03)%, (0.76 ± 0.02)%] (t4 d = 4.695, P 4 d = 0.003; t7 d = 6.025, P 7 d = 0.001). On P4 in RP group, the proportions of group 2 [ (0.44 ± 0.01)%] was less than that of group 1 [ (0.54 ± 0.04)%] (t4 d = 5.000, P 4 d = 0.002). CONCLUSIONS: The premature rats have lower weight and much slower rate of early retinal vascularization, as compared with the normal rats. Furthermore, in the premature rats, the proportion of retinal vascularization in larger litters is less than that in smaller litters. These results indicate that premature birth and larger litter size have effects on the development of rat retinal vasculature.

Detection of amylase activity and moisture content in rice by reflectance spectroscopy combined with spectral data transformation.

In this study, reflectance spectroscopy was used to achieve rapid and non-destructive detection of amylase activity and moisture content in rice. Since rice husk can interfere with spectral measurements, spectral data transformation was used to remove the husk interference. Reflectance spectra of rice were transformed by direct standardization, convolutional autoencoder network, and kernel regression (KR). Then, random frog and elliptical envelope were adopted to select effective wavelengths, and partial least squares regression (PLSR) and support vector regression were used to establish analysis models. The optimal transformation was from KR, and PLSR and effective wavelengths of the transformed spectra obtained excellent performance with coefficient of determination of test of 0.6987 and 0.8317 and root-mean-square error of test of 0.3359 and 2.2239, respectively. The result was better than that of the rice spectra and was close to that of the husked rice spectra. When the moisture content was integrated into the regression model of amylase activity, a better result was obtained. Thus, the proposed method can detect amylase activity and moisture content in rice accurately.

[Incidence of retinopathy of prematurity in mainland of China over the last 20 years].

Retinopathy of prematurity (ROP) is one of the important causes of childhood blindness in China with an increasing trend of affected infants. It gives great burden on both the individuals and the society. With the publishing of guidelines on oxygenation policies by Ministry of Health, the screening of ROP has been gradually performed nation-wide. But the prevalence data of ROP is still confusing. We reviewed literature over the last 20 years about causes of childhood blindness in blind school students and ROP screening. This study could provide preliminary evidence about prevalence of ROP in mainland of China and could be benefit for further prevention and the control of ROP.

Reflectance spectroscopy with operator difference for determination of behenic acid in edible vegetable oils by using convolutional neural network and polynomial correction.

A novel polynomial correction method, order-adaptive polynomial correction (OAPC), was proposed to correct reflectance spectra with operator differences, and convolutional neural network (CNN) was used to develop analysis model to predict behenic acid in edible oils. With application of OAPC, CNN performed well with coefficient of determination of correction (R2cor) of 0.8843 and root mean square error of correction (RMSEcor) of 0.1182, outperforming partial least squares regression, support vector regression and random forest with OAPC, as well as the cases without OAPC. Based on 16 effective wavelengths selected by combination of bootstrapping soft shrinkage, random frog and Pearson's correlation, CNN and OAPC exhibited excellent performance with R2cor of 0.9560 and RMSEcor of 0.0730. Meanwhile, only 5% correction samples were selected by Kennard-Stone for OAPC. Overall, the proposed method could alleviate the impact of operator differences on spectral analysis, thereby providing potential to correct differences from measurement instruments or environments.

The Significance of the Ocular Adverse Effect Induced by Systemic Taxane Application.

In recent years, in-depth research on anti-tumor therapy has brought the emergence of new active chemotherapeutic agents and combination regimens. However, as one of them, taxane drugs are widely used in clinical practice, but it should be noted that many side reactions caused by their application bring some difficulties to routine management. Among the side reactions related to taxane anti-tumor therapy, ocular adverse reactions are occasionally reported and are not life-threatening but may seriously affect patients' life quality. Thus, the continuation, reduction and cessation of taxane chemotherapy still need to be further evaluated by ophthalmologists and oncologists once the side effects show up. To prevent ocular side reactions, close attention should be paid to complications during medication. To facilitate the oncology department and ophthalmologists to comprehensively understand the ophthalmic adverse reactions of taxane drugs and their possible mechanisms and improve drug use efficiency, we collected relevant literature and reviewed and provided some suggestions for the monitoring and managing of ophthalmic toxicity.

Fusion of electronic nose and hyperspectral imaging for mutton freshness detection using input-modified convolution neural network.

Electronic nose (E-nose) and hyperspectral image (HSI) were combined to evaluate mutton total volatile basic nitrogen (TVB-N), which is a comprehensive index of freshness. The response values of 10 E-nose sensors were collected, and seven responsive sensors were screened via histogram statistics. Reflectance spectra and image features were extracted from HSI images, and the effective variables were selected through random frog and Pearson correlation analyses. With multi-source features, an input-modified convolution neural network (IMCNN) was constructed to predict TVB-N. The seven E-nose sensors, spectra of effective wavelengths (EWs), and five important image features were combined with IMCNN to achieve the best result, with the root mean square error, correlation coefficient, and ratio of performance deviation of the prediction set of 3.039 mg/100 g, 0.920, and 3.59, respectively. Hence, the proposed method furnishes an approach to accurately analyze mutton freshness and provide a technical basis for investigation of other meat qualities.

[Recent advances in tuberculous uveitis].

With an increasing number of new cases of tuberculosis every year, the incidence of tuberculous uveitis presents a rising trend. The disease is associated with a wide spectrum of clinical manifestations. The common clinical presentations appear to be anterior uveitis, choroidal tubercles, multifocal choroiditis, rarely serpiginous-like choroiditis, subretinal abscesses or suspected ocular tumors. Macular edema can be the only ocular manifestation of tuberculosis. With absence of proper diagnostic standard, it usually leads to missed diagnosis, misdiagnosis, and delayed diagnosis of tuberculous uveitis which can result in severe consequences such as vision loss, blind, and even eye enucleation. New technology such as PCR and Interferon-Gamma release assays can be helpful for the diagnosis of tuberculous uveitis. The early diagnosis and standard treatment of tuberculous uveitis are in urgent need.

Effect(s) of preterm birth on normal retinal vascular development and oxygen-induced retinopathy in the neonatal rat.

PURPOSE: Maturity is a critical factor in the pathogenesis of retinopathy of prematurity (ROP). One widely used method for studying this condition is that of oxygen-induced retinopathy (OIR). The general conditions of an OIR term animal, both at the time of birth and following birth, differ from those of the preterm infant. This, to simulate preterm conditions and to provide a basis for further studies on ROP, we investigated the effect(s) of preterm birth on retinal vascularization using the neonatal rat. MATERIALS AND METHODS: Sprague-Dawley (SD) rats were delivered preterm by caesarean section on the day 19 of gestation. Term pups were used as controls. On the day of birth, preterm and term pups were housed under conditions of room air or cyclic oxygen. Retinas of pups housed in room air on days 4, 7, 10, 14, 18 and 22, as well as pups housed in oxygen on days 14, 18, and 22 were whole-mounted and stained with isolectin-B4. On day 18, cross-sections of the retina were cut and stained with hematoxylin and eosin for the identification of preretinal neovascular tufts. Images of avascular and neovascular areas were compared using light and fluorescence microscopy. RESULTS: Preterm pups had significantly larger avascular retinal areas than term rats on the various postnatal days. After exposure to cyclic oxygen, preterm pups demonstrated significantly larger avascular (days 14 and 18) and neovascular areas (day 18) compared with term rats. On day 22, residual retinopathy of preterm pups was greater than that of term pups. CONCLUSIONS: Preterm birth of rats, which are comparable in their physiology to humans, had negative effects on retinal vascularization. The impaired retinal vascular development and subsequent vasoproliferation resulting from hyperoxia in preterm pups is more severe and enduring.