[Endogenous self-repair in immature white matter induced by ischemia in neonatal rats].

OBJECTIVE: To study in vivo the endogenous self-repair mechanism in immature white matter induced by ischemia in neonatal rats with periventricular leukomalacia (PVL). METHODS: Five-day-old neonatal Sprague-Dawley (SD) rats were randomly divided into sham and PVL groups. Rat model of PVL was prepared by ligation of the right common carotid artery following 2 hours of exposure to 8% oxygen. Pathological changes and myelination in the white matter were assessed under light and electron microscopy at 7 and 21 days after PVL. O4-positive OL precursor cells in the white matter were determined with immunofluorescence staining. Activation, proliferation, migration and differentiation of glial progenitor cells in SVZ were observed using immunofluorescent double labeling of either NG2 (marker of progenitor cells) and 5-bromodeoxyuridine (BrdU), or O4 (marker of OL precursor cells) and BrdU. RESULTS: All rats in the PVL group manifested either mild or severe white matter injury under light microscopy, and had higher pathological scores of white matter compared with the sham group at 7 and 21 days after PVL (P<0.05). Electron microscopy showed that the number and thickness of myelin sheath in the PVL group were significantly reduced compared with the sham group (P<0.01). O4-positive OL precursor cells in the white matter observed under fluorescence microscopy were significantly reduced in the PVL group compared with the sham group (P<0.05). BrdU/NG2-positive cells in the SVZ increased significantly in the PVL group 48 hours after PVL and migrated into the periventricular area, reaching a peak on day 7 after PVL. BrdU/O4-positive newborn cells began to appear in the periventricular area 72 hours after PVL, and the number of BrdU/O4-positive cells in the PVL group was statistically more than in the sham group on day 21 after PVL (P<0.05). CONCLUSIONS: Ischemia may induce brain self-repair in neonatal rats, resulting in activation and proliferation of NG2 glial progenitor cells in the SVZ migration and differentiation into OL precursor cells in periventricular white matter.

[Effect of single or combined application of UDP-glucose, GDNF and memantine on improvement of white matter injury in neonatal rats assessed with light and electron microscopy pathologically].

OBJECTIVE: To evaluate pathologically the effect of the single or combined application of UDP-glucose, GDNF and memantine on the improvement of white matter injury in neonatal rats with periventricular leukomalacia (PVL) under light and electron microscopy. METHODS: A five-day-old neonatal rat model for PVL was established by ligation of the lateral common carotid artery following 120-minute hypoxia. Rats were randomly divided into six groups (30 rats in each group): sham-operated, PVL, UDP-glucose (UDP-glucose 2000 mg/kg intraperitoneally after PVL), GDNF (GDNF 100 µg/kg intracerebrally after PVL), tmemantine (memantine 20 mg/kg intraperitoneally after PVL), and a combination administration of three drugs (UDP-glucose, GDNF and memantine). The rats were sacrificed 7 or 21 days after PVL for assessment of pathological changes in the white matter under both light and electron microscopy. The number and thickness of the myelin sheath in the white matter were measured under electron microscopy, and both of pathological grading and scoring were undertaken under light microscopy. RESULTS: There was rare and sparse myelinogenesis with a loose arrangement of nerve fibers in the white matter under electron microscopy in the PVL group at 7 and 21 days after PVL. The number and thickness of the myelin sheath in the PVL group were significantly less than in the sham-operated, UDP-glucose, GDNF, memantine and combination administration groups (P<0.01). The results of pathological grading of white matter under light microscopy showed that all rats in the PVL group manifested either mild injury (38%-50%) or severe injury (50%-62%) at 7 and 21 days after PVL. The majority of rats (50%-88%) in the four drug administration groups had normal white matter at 7 and 21 days after PVL. The pathological scores at 7 and 21 days after PVL in the PVL group were the highest, and they were significantly higher than in the other five groups (P<0.05). CONCLUSIONS: The single or combined application of UDP-glucose, GDNF and memantine may significantly improve pathological changes in the white matter of rats with PVL. The favorable effect is inferred to be closely correlated with the improvement of brain microenvironment and the enhancement of nerve regeneration promoted by the three drugs.

[Effects of glial cell line-derived neurotrophic factor and memantine on long-term prognosis in neonatal rats with periventricular leukomalacia].

OBJECTIVE: To evaluate the effects of glial cell line-derived neurotrophic factor (GDNF) and memantine on the long-term prognosis in neonatal rats with ischemia-induced periventricular leukomalacia (PVL). METHODS: Thirty-two 5-day-old neonatal rats were randomly divided into 4 groups: sham-operated, PVL, GDNF-treated and memantine-treated. PVL was induced by right carotid artery ligation and hypoxia in the PVL, GDNF-treated and memantine-treated groups. GDNF (100 µg/kg) or memantine (20 mg/kg) was injected in the two treatment groups immediately after PVL inducement. The weight of the rats was measured immediately before and after hypoxia ischemia (HI). Both of Morris water maze test and Rivlin inclined plane test were performed at 26 days old (21 days after HI). The values of the escape latency (EL) and swimming distance, and the maximum inclined plane degree which the rats could stand at least 5 seconds were compared among the four groups. RESULTS: The lower weight, the prolonged mean values of EL and swimming distance and the reduced maximum inclined plane degree were observed in the PVL group compared to those in the sham-operated, GDNF-treated and memantine-treated groups. There were no significant differences in the weight, the values of EI and swimming distance and the maximum inclined plane degree between the two treatment groups and the sham-operated group. CONCLUSIONS: The administration of either GDNF or memantine can markedly increase the abilities of spatial discrimination,learning and memory, and motor coordination, promote weight gain, and improve long-term prognosis in rats with PVL.

Successful Outcome of Patellectomy Plus Chemotherapy for Primary Bone Lymphoma of the Patella: A Case Report and Literature Review.

Primary bone lymphoma (PBL) is a rare but distinct clinicopathological disease, usually occurring in the pelvis, spine, and ribs. To date, only a few cases have been reported as beginning in the patella. Due to the lack of clinical evidence, the optimal treatment strategy has not been established. Here, we report a case that presented unexplained right knee pain. The case was diagnosed with the non-germinal center, diffuse large B cell lymphoma in the patella by imaging examinations and bone biopsy. Then, the patient received a patellectomy and eight cycles of R-CHOP chemotherapy. After treatment, the patient achieved a favorable prognosis and satisfactory functional recovery.

Traumatic choroidal injuries - classification, incidence, diagnosis and prognosis twenty-year results of Eye Injury Vitrectomy Study.

PURPOSE: To characterize the classification, incidence, diagnosis and prognosis of traumatic choroidal injuries. METHODS: Subjects were selected from the database of the Eye Injury Vitrectomy Study (EIVS) and were examined for occurrences of different categories of choroidal injuries. Standard photographs were collected. Anatomical and visual outcomes were assessed in patients with greater than 1 year of follow-up. Eyes that had no light perception (NLP) and/or phthisis bulbi were defined as having had unfavourable outcomes. The percentage of eyes with an unfavourable outcome was analysed for different types of choroidal injuries. RESULTS: Nine categories of choroidal injuries with distinctive features were identified in the EIVS database. The incidence and the percentage of eyes with an unfavourable outcome in each injury category were as follows: suprachoroidal effusion, 21.2% (7.2%); suprachoroidal haemorrhage, 12.8% (11.2%); massive suprachoroidal haemorrhage, 4.0% (64.9%); choroidal avulsion, 4.2% (92.2%); traumatic chorioretinal rupture, 1.8% (13.3%); choroidal rupture, 4.8% (6.8%); choroidal loss, 1.6% (79.3%); choroidal hole, 1.1% (5.3%); and choroidal damage at the wound site, 39.2% (17.7%). CONCLUSIONS: Ocular trauma can cause a variety of choroidal injuries that have distinctive features, some of which are associated with a high frequency of unfavourable prognoses.

Prognostic factors and long-term outcomes of eye-globe perforation: Eye injury vitrectomy study.

PURPOSE: To delineate anatomic and visual outcomes of injured eye globes with perforating, and to develop the prognostic indicators for perforating eyes. METHODS: The case series study, from a multicenter prospective cohort database. To the date of December 31st, 2018, of 63 perforating globes were selected. All cases underwent vitreoretinal surgeries or enucleations, and were followed up for at least 6 months. Demographic characteristics, basic examination for traumatized eyes, and intraocular tissue damages were recorded by surgery-in-chief. At the follow-up visit, best corrected VA, intraocular pressure, the intraocular tamponade material, retinal anatomic outcome of eye-globes, and phthisis or enucleation were evaluated. RESULTS: Fifty injured eyes (79%) were caused by sharp objects and 13 eyes (21%) were injured by a missiles. Twenty-two injured eyes can be anatomically restored with final vision of more than 4/200 through vitreoretinal surgery. The PVR-C (OR = 5.67, P = 0.01), area of retinectomy more than 2 times of optic disk (OR = 5.16, P = 0.04), and macular damage (OR = 6.38, P = 0.01) were correlated with unfavorable outcomes. CONCLUSION: The injured eyes with perforation can be saved through vitreoretinal surgery, the PVR-C, retinectomy more than 2 times of optic disk, and macular damage were independent risk factors for poor long-term prognosis.

Mechanism and prognostic indicators for explosion-related eye trauma: eye injury vitrectomy study.

PURPOSE: To explore the clinical features, surgical interventions and prognosis of injured eyes following explosion and to develop the risk factors for poor prognosis. METHODS: A nested case-control study. To the date of 31 December 2018, 99 explosion-related eye globes were selected from the Eye Injury Vitrectomy Study database, which is a multicenter prospective cohort study and began in 1990s. All cases selected underwent vitreoretinal surgery or enucleation and were followed up for at least 6 months. Clinically meaningful preoperative variables and outcomes were used to develop logistic regression models. RESULTS: The unfavourable outcomes were defined as silicone oil-filled eyes, phthisis bulbi, enucleation and anatomically restored eyes whose final BCVA is worse than initial vision after 6 months of follow-up. The proportion of unfavourable outcomes was 92.0%, 60.9% and 66.7% in large festive fireworks, detonator and beer bottle groups respective. The anatomic and visual outcome of injured eyes with combined injury of blast wave and projectile were worse than that of ruptured eyes (Fisher's exact = 0.041). The extrusion of iris/lens (OR = 3.20, p = 0.015), PVR-C (OR = 6.08, p = 0.036) and choroid damage (OR = 5.84, p = 0.025) is independent risk factors of unfavourable prognosis for explosion-related eye trauma. CONCLUSION: The extrusion of iris/lens, PVR-C and choroid damage is the independent risk factors for unfavourable outcomes in explosion-related eye trauma. There is a unique injury mechanism in explosion-related eye trauma. SUMMARY STATEMENT: Through the nested case-control study, the extrusion of iris/lens, PVR-C, and choroid damage are the independent risk factors for unfavorable outcomes in explosion-related eye trauma. The mechanism of open globe mixture and close globe mixture in explosion-related eye trauma need more cases and participating units to explore together in the future.

Anterior segment optical coherence tomography measurement of flap thickness after myopic LASIK using the Moria one use-plus microkeratome.

PURPOSE: To analyze the accuracy and consistency of corneal flap thickness created in myopic LASIK using the Moria One Use-Plus microkeratome compared with the Moria M2 Single Use 90-microm microkeratome. METHODS: Bilateral LASIK was performed in 68 myopic patients. Flaps were created using the One Use-Plus microkeratome in 82 eyes (41 patients) and the M2 90-microm microkeratome in 54 eyes (27 patients). Flap complications and visual outcomes were evaluated. Horizontal "High Res. Corneal" scan pattern of anterior segment optical coherence tomography (AS-OCT) was applied to measure flap thickness at five locations (0, +/-2, and +/-3.5 mm from the corneal vertex) on the first postoperative day. RESULTS: No significant differences were noted in flap complications and visual outcomes between groups. The central flap thickness was dramatically thinner in the One Use-Plus group (114.7+/-10.1 microm and 109.4+/-11.0 microm for right and left eyes, respectively) than in the M2 group (155.6+/-14.8 microm and 151.6+/-12.5 microm for right and left eyes, respectively) (P<.001). The One Use-Plus did not show a markedly better uniformity than the M2; the variation was mainly observed in the periphery. Multiple linear regression showed that for the One Use-Plus, the steeper the preoperative keratometry, the thicker the flap thickness, and for the M2, the thicker the preoperative pachymetry, the thicker the flap (P<.1). CONCLUSIONS: The One Use-Plus and M2 microkeratomes have similar safety and efficacy. The flap created by the One Use-Plus was much thinner than the flap created with the M2; however, the One Use-Plus can not realize a fully planar-shaped flap.

[1400W blocks death pathway of LPS-induced activated-microglia to preOLs].

OBJECTIVE: To explore the efficacy of inductible nitric oxide synthase (iNOS) inhibitor 1400W in vivo in blocking the death pathway of lipopolysaccharide (LPS)-induced activated-microglia to preoligodendrocytes (preOLs) in neonatal rats with infective-type periventricular leukomalacia (PVL) induced by LPS. METHODS: Two-day-old neonatal rats were randomly divided into: a sham-operated group, an untreated PVL group, and four 1400W-treated PVL groups that were subcutaneously administrated with 20 mg/kg of 1400W at 0 h, 8 hrs, 16 hrs, and 24 hrs after LPS induction, respectively. The brain specimens were obtained 5 days after LPS induction. The pathological assessment of cerebral white matter was performed under a light microscope. Concentrations of nitric oxide (NO) were measured by nitric acid-deoxidize colorimetry. Synthesis of iNOS was determined by Western blot analysis. Peroxynitrite (ONOO(-)) level and the amount of preOLs were determined by immunocytochemistry. RETHODS: The obvious injuries of periventricular white matter, massive loss of positive O4-labelled preOLs, and increased levels of NO, ONOO(-) and iNOS were observed in neonatal rats with PVL. Compared to the untreated PVL group, the use of 1400W at 0 h, 8 hrs and 16 hrs after LPS induction significantly improved white matter injuries, reduced the levels of NO, ONOO(-) and iNOS, and increased the amount of O4-labelled preOLs. However, the use of 1400W at 24 hrs after LPS induction did not result in the improvements. CONCLUSIONS: iNOS inhibitor 1400W can effectively block the toxicity of LPS-activated microglia to preOLs and protect cerebral white matter through inhibiting iNOS and reducing the production of NO and ONOO(-). The use of 1400W within 16 hrs after LPS induction may provide cerebral protections in neonatal rats with PVL.

CaSR is required for ischemia-induced proliferation and differentiation of white matter progenitor cells from neonatal rats.

This study was designed to investigate whether calcium-sensing receptor (CaSR) could induce immture white matter progenitor cells proliferation and differentiation into oligodendrocyte(OL) precursor cells after oxygen-glucose deprivation (OGD) in vitro. Progenitor cells of immature white matter originating from five-day-old newborn rats were divided into control, OGD, control + CaSR silencing, OGD + CaSR silencing, control + adenosine triphosphate magnesium chloride (ATP-MgCl2) and OGD + ATP-MgCl2 groups. Immunofluorescence, real-time RT-PCR, gene silencing, Hoechst 33342/propidium iodide (PI) and Flow cytometry tests were used to examine the proliferation, differentiation and survival of the white matter progenitor cells in the different treatment groups. The results showed that normal immature white matter progenitor cells have certain ability of self-proliferation and differentiation in vitro. OGD could further induce progenitor cells proliferation and differentiation into O4 + OL precursor cells by activating CaSR, but OGD also induced more necrosis and apoptosis of newborn cells and less MBP + OL formation. The addition of ATP-MgCl2 as an activating agent of CaSR further promoted cell proliferation and differentiation both under normal and OGD conditions and reduced OGD-induced apoptosis and necrosis, while CaSR silenced resulted in minimal cell proliferation, differentiation and survival. This study suggests that CaSR plays an important role in the induction of immature white matter progenitor cells proliferation and differentiation into OL precursor cells after OGD, which may provide a new angle to further study whether CaSR initiates the intrinsic repair potential of immature white matter after ischemia in vivo.

GPR17 plays a role in ischemia-induced endogenous repair of immature neonatal cerebral White matter.

Whether GPR17 has the same distribution and repair mechanism in immature white matter with periventricular leukomalacia (PVL) as in the adult brain remains to be determined. This study tried to explore the expression phase and site of GPR17, and to investigate the effect of silencing GPR17 on endogenous repair mechanism of immature white matter with PVL. Ischemic PVL in vivo results showed that GPR17 gene and protein expression increased more in the PVL than in the sham group at 12 h-24 h and 72h to 7 days after PVL. NG2+/GPR17+progenitor cells at 48 h-96 h and O4+/GPR17+precursor cells at 72h to 7d were also significantly increased in the PVL compared to the sham groups. Results in vitro showed that oxygen-glucose deprivation (OGD) also induced more GPR17 gene and protein expression than control at 48 h-72 h. There were more NG2+/GPR17+progenitor cells at 24 h-48 h and O4+/GPR17+precursor cells at 48 h-72 h in the OGD groups, as well. The functional role of GPR17 in the intrinsic repair response to ischemia was tested using GPR17 gene silencing. The progenitor cells and OL precursors in the OGD+GPR17 silencing group were both significantly less than those in the control, OGD and OGD+gene silencing control groups. The apoptotic percentage of cells in OGD+GPR17 silencing group was also much higher. In summary, ischemia-induced GPR17 expression was shown to contribute to glial-derived progenitor cell proliferation and differentiation into OL precursors, which may provide a therapeutic target for immature neonatal white matter injury after ischemia.

Evaluation of Lateral-Flow Assay for Rapid Detection of Influenza Virus.

BACKGROUND: Influenza virus mainly causes acute respiratory infections in humans. However, the diagnosis of influenza is not accurate based on clinical evidence, as the symptoms of flu are similar to other respiratory virus. The lateral-flow assay is a rapid method to detect influenza virus. But the effectiveness of the technique in detecting flu viruses is unclear. Hence, a meta-analysis would be performed to evaluate the accuracy of LFA in detecting influenza virus. METHODS: Relevant literature was searched out in PubMed, Embase, Web of Science, and Cochrane Library databases with the keywords "lateral flow assay" and "flu virus". By Meta-DiSc software, pooled sensitivity, pooled specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), summary receiver operating characteristic curve (SROC), and area under the curve (AUC) can be calculated. RESULTS: This meta-analysis contains 13 studies and 24 data. The pooled sensitivity and specificity of the influenza virus detected by LFA were 0.84 (95% CI: 0.82-0.86) and 0.97 (95% CI: 0.97-0.98), respectively. The pooled values of PLR, NLR, DOR, and SROC were 32.68 (17.16-62.24), 0.17 (0.13-0.24), 334.07 (144.27-773.53), and 0.9877. No publication bias was found. CONCLUSIONS: LFA exhibited high sensitivity and specificity in diagnosing influenza virus. It is a valuable alternative method which can diagnose influenza virus quickly. However, more evidence is required to confirm whether LFA is comparable to traditional methods for detecting the virus.

Effect of intravitreal ranibizumab pretreatment on vitrectomy in young patients with proliferative diabetic retinopathy.

BACKGROUND: Younger patients who underwent vitrectomy for proliferative diabetic retinopathy (PDR) display more aggressive nature distinguished from the older patients. Preoperative anti-VEGF therapy has been widely used as an adjunct for PDR surgery. However, the effect of anti-VEGF administration in young diabetics has rarely been evaluated in previous studies. The purpose of this study was to evaluate the effects of ranibizumab pretreatment on vitrectomy surgery in young patients with PDR. METHODS: This was a prospective nonrandomized comparative study. Young patients (<40 years old) undergoing diabetic vitrectomy with or without ranibizumab pretreatment (25 eyes in each group) were analyzed in this study. The use of the drug was determined by the patients' own preference. The two surgical groups were matched according to a complexity score. Intravitreal injection of ranibizumab (IVR) was performed 3-5 days prior to the vitrectomy surgery in the IVR group. Intraoperative records including total surgical time, intraoperative bleeding, the use of endodiathermy, the frequency of relaxing retinotomies, the incidence of iatrogenic retinal breaks, and the use of perfluorocarbon liquid (PFCL) and silicone oil tamponade, and postoperative indices regarding recurrent vitreous hemorrhage (VH), neovascular glaucoma (NVG), recurrent retinal detachment, and visual outcome were evaluated between the two groups. All patients were followed up for one year after surgery. RESULTS: In young PDR patients, the severity of intraoperative bleeding was significantly lower in the IVR group than in the control group (P=0.04). The total surgical time was shorter in the IVR group than in the control group. However, the rate of relaxing retinotomy, the incidence of iatrogenic retinal breaks and the use of PFCL and silicone oil tamponade were not affected by IVR pretreatment but affected by the complexity score of the case. Early postvitrectomy hemorrhage occurred less frequently in the IVR group than in the control group (P<0.001), Early visual recovery was better in the IVR group than in the control group (P=0.03). However, there were no significant differences in the development of late recurrent VH, NVG, recurrent retinal detachment, and final visual outcome. CONCLUSIONS: IVR pretreatment is a safe and effective adjunct to vitrectomy in reducing intraoperative and early postvitrectomy bleeding and should be suggested in young PDR patients. However, IVR does not reduce the incidence of intraoperative and late postoperative complications in these patients. The risk of iatrogenic retinal breaks and silicone oil use are closely correlated with the complexity score of the surgical cases.

Endothelial keratoplasty: the use of viscoelastic as an aid in reattaching the dislocated graft in abnormally structured eyes.

PURPOSE: To explore the feasibility of reattaching the dislocated graft with viscoelastic in abnormally structured eyes after Descemet-stripping automated endothelial keratoplasty (DSAEK). DESIGN: Retrospective case series. PARTICIPANTS: Five pseudophakic bullous keratopathy cases (5 eyes) with a history of vitrectomy and/or iris-lens diaphragm injury. METHODS: After DSAEK, graft dislocation occurred in each of the 5 cases (5 eyes). We attempted to fill the anterior chamber (AC) with an air bubble to push up the dislocated graft, but this was not successful. We then injected balanced salt solution into the vitreous body to obtain normal intraocular pressure (IOP) and injected a small amount of viscoelastic (Healon GV) to support the AC. Next, we injected an air bubble into the AC. MAIN OUTCOME MEASURES: The position of the grafts was checked with a slit lamp and anterior segment optical coherence tomography (AS-OCT). The IOP was observed with Goldmann tonometer. The best visual acuity was checked. RESULTS: As observed through the slit lamp and AS-OCT, the grafts reattached well in all patients. The IOP was normal in all patients except one, who had high IOP 1 month postoperatively. After receiving drug treatment, the patient's IOP returned to normal. The grafts had slight edema on postoperative day 1, but became transparent between days 5 and 8. CONCLUSIONS: Viscoelastic aided in the reattachment of the dislocated graft in eyes with a history of vitrectomy and/or iris-lens diaphragm injury. The presence of viscoelastic in the AC in the early period of post-DSAEK was well tolerated in this small series.

[Multicenter follow-up report of 147 premature infants with brain injuries from 6 hospitals in China].

OBJECTIVE: Sponsored by the Subspecialty Group of Neonatology of Pediatric Society, China Medical Association, more than 10 large-scale hospitals participated in the near two-year multicenter investigation for Brain Injuries in Premature Infants in China. The present study presents the follow-up results of 147 premature infants with brain injuries from 6 Third Class A Level hospitals. METHODS: All premature infants with intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL) diagnosed in the early neonatal period in the 6 hospitals were followed-up between January 2005 and August 2006. Based on the synthetic results of physical development, examination of nervous system, intelligence tests and cranial ultrasound, the premature infants with brain injuries were classified as normal development, marginal development and retarded development. RESULTS: One hundred and forty-seven premature infants with brain injuries from the 6 hospitals consisted of 141 cases of IVH and 36 cases of PVL (30 cases having IVH and PVL). Based on the synthetic follow-up results, 51.4% of premature infants with brain injuries were generally assessed as normal development, 38.4% as marginal development and 10.7% as retarded development. Among them, delayed growth in head circumference, height and weight was 13.4%; the occurrence frequency of cerebral paralysis (CP) was 7.1% in PVL grade I, 28.6% in PVL grade II and 100% in PVL grade III; 12.7% showed retarded development of intelligence; and 30% presented post-injurious changes on cranial sonography. CONCLUSIONS: The data of the multicenter follow-up can basically reflect the short-term prognosis of premature infants with brain injuries in major big cities of China. About 10% of them have retarded physical, motor-and mental developments. The long-term regular follow-up study is expected for more premature infants with brain injuries, and behavioral sequelae of brain injuries which may occur in peri-school age and adolescence should be paid particularly close attention.

Change of Vascular Endothelial Growth Factor Levels following Vitrectomy in Eyes with Proliferative Diabetic Retinopathy.

PURPOSE: To study the change of concentrations of vascular endothelial growth factor (VEGF) in vitreous cavity after vitrectomy in eyes with proliferative diabetic retinopathy (PDR). METHODS: In this retrospective study, intravitreal fluid samples were taken at baseline (beginning of the vitrectomy) and postoperatively (several days later after vitrectomy) at the time of prophylactic injection of bevacizumab in forty-eight eyes of forty-eight patients with PDR. Postvitrectomy fluid samples were divided into four groups according to the time interval between the vitrectomy and the injection (group 1, 3-5 days; group 2, 6-10 days; group 3, 11-15 days; group 4, 16-21 days; twelve eyes in each group). Postvitrectomy fluid sample was paired with baseline sample for each eye. VEGF concentrations in the samples were determined by enzyme-linked immunosorbent assay. Recurrent vitreous hemorrhage and neovascular glaucoma within six months postvitrectomy were also analyzed. RESULTS: Overall, the intravitreal VEGF level after vitrectomy (median, 36.95 pg/ml; range, 3.2-1,299.4 pg/ml) was significantly less than the VEGF level at baseline (median, 704.5 pg/ml; range, 30.6-1,981.1 pg/ml). Postoperative and baseline VEGF levels were significantly correlated (r = 0.499, p < 0.01). Both the absolute value of postoperative VEGF concentrations and the postop/baseline VEGF ratios declined with time and dramatically decreased in groups 3 and 4. In only two eyes, the postoperative VEGF level was even higher than the baseline VEGF level (postop/baseline VEGF ratio >1), and recurrent vitreous hemorrhage developed within six months in these two eyes. CONCLUSIONS: After vitrectomy for PDR, intravitreal VEGF levels decreased substantially in the majority of patients, while persistent high-VEGF level occurred in a few individuals. Postoperative VEGF levels and postop/baseline VEGF ratio declined with time. The postop/preop VEGF ratio may serve as a predictor for late complications.

Traumatic macular hole study: a multicenter comparative study between immediate vitrectomy and six-month observation for spontaneous closure.

BACKGROUND: Closure of traumatic macular hole (TMH) can be achieved spontaneously or by surgical intervention. Thus far, there exist no prospective comparative studies that have analyzed the difference between the two modalities. This study aimed to compare the anatomical and visual recovery of eyes with TMH following either an immediate vitrectomy or six-month observation. METHODS: This was a multicenter prospective comparative study. Eight centers participated in the study. Patient data from 40 eyes with a recent history of blunt ocular trauma and newly formed full-thickness TMH were recruited in this study. The participating patients selected between an early vitrectomy or a six-month observation after a doctor explained the potential benefits and risks of both strategies in an unbiased manner. Twenty-five patients underwent an immediate vitrectomy, and 15 patients received six-month observation. Patients were assessed by spectral-domain optical coherence tomography (SD-OCT) and best-corrected visual acuity (BCVA). RESULTS: Closure rates were 66.7% for the observational group, and 100% for the surgical group (P=0.002). There were no vision-threatening ocular complications in both groups. For the observational group, the mean closure time was 2.5±1.6 months, and 80% of the hole closure occurred within 3 months; cystic edema on the edge of the hole at baseline was significantly more frequent in the non-closed subgroup than in the closed subgroup (P=0.03). There were no significant differences in the foveal microstructure and in the final visual outcome between the spontaneously closed cases and the surgically closed cases. CONCLUSIONS: TMH had a moderately high incidence of spontaneous closure, but an immediate vitrectomy achieved an even higher closure rate. Vitrectomy was effective and safe to treat TMH, while a 3-month observation for spontaneous closure may be an alternative modality for TMH management. Cystic edema on the edge of the hole may be an unfavorable factor for the spontaneous closure of TMH.

[Multicenter investigation for incidence of periventricular leukomalacia in premature infants in China].

OBJECTIVE: Sponsored by the Subspecialty Group of Neonatology of Pediatric Society, China Medical Association, more than 10 large-scale hospitals participated in the near two-year multicenter investigation for brain injuries in premature infants in China. This study presented the investigation result for the incidence of periventricular leukomalacia (PVL) in premature infants from 10 Third Class A Level hospitals. METHODS: The premature infants with a gestation age<37 weeks in the 10 hospitals were given routine cranial ultrasound scanning within seven days after birth, and then repeated every 3-7 days until discharge from January 2005 to August 2006. The severity of PVL was graded based on de Vries classification. RESULTS: A total of 4 933 premature infants were enrolled. The total incidence of PVL and the incidence of cystic PVL were 2.3% (112/4 933) and 0.3% (16/4 933), respectively. Of the 112 PVL cases, 96 (85.7%) were with grade I, 14 (12.5%) with grade II, and 2 (1.8%) with grade III. The incidence of PVL in 4 maternal and child health care hospitals were significantly lower than that in 6 general or children's hospitals (1.4% vs 2.8%) (X2=10.284, P<0.01). Vaginal delivery and mechanical ventilation were possible high-risk factors for the development of cystic PVL. CONCLUSIONS: The data of the multicenter investigation can basically reflect the situation about the occurrence of PVL in premature infants in major big cities of China. It is important to improve the ability to recognize the sonogram of non-cystic periventricular white matter injury.

[Cerebral pathological evaluation following neural stem cells intraventricular transplantation in neonatal rats with periventricular leukomalacia].

OBJECTIVE: To evaluate the brain pathological changes following exdogenous neural stem cells (NSCs) intraventricular transplantation in neonatal rats with periventricular leukomalacia (PVL), and to explore the feasibility of NSCs transplantation for the treatment of PVL in premature infants. METHODS: NSCs were prepared from E14 embryonic rat brain. Two-day-old neonatal rats were randomly divided into six groups: PVL, PVL+culture medium, PVL+NSCs, sham operation, sham operation+culture medium, and sham operation+NSCs (18-21 rats each group). Intraventricular transplantation of exdogenous NSCs was performed 72 hrs after PVL induction or sham operation. The cerebral pathological evaluation was undertaken by light microscopy 7, 14 and 21 days after transplantation. RESULTS: The pathological changes in the cerebral white matter were gradually improved with the prolonged time after transplantation. After 21 days of transplantation, 50% of the cerebral white matter showed mild pathological changes and 50% of that showed severe pathological changes, with neuronal pathological scores of 1.28+/-0.86, in the untreated PVL group. In the PVL+NSCs group, 30% of normal white matter, 40% of mild and 30% of severe pathological changes in the white matter were observed, with neuronal pathological scores of 0.32+/-0.16, 21 days after transplantation. There were very significant differences in both of pathological changes in the cerebral white matter and neuronal pathological scores between the PVL and PVL+NSCs groups (x2=10.7, P<0.01; F=29.664, P<0.01). CONCLUSIONS: Intraventricular transplantation of exdogenous NSCs can apparently improve cerebral white matter damage. It is suggested that intraventricular transplantation of NSCs is of a great potential feasibility for the treatment of PVL in premature infants.

N-cadherin expression in a rat model of retinal detachment and reattachment.

PURPOSE: To observe the changes in N-cadherin expression in the retina after experimental retinal detachment (RD) and reattachment in the rat and to explore the role N-cadherin might play after RD. METHODS: Forty rat retinas were detached by transscleral injection of 1.4% sodium hyaluronate into the subretinal space. The eyes were enucleated at different time intervals (n = 5), followed by fixation, embedding, and sectioning. The differences in N-cadherin expression in the normal retina, detached retina, and spontaneously reattached retina were determined. Furthermore, an N-cadherin antagonist was injected in combination with 1.4% sodium hyaluronate into the subretinal space in another 10 eyes, in an attempt to demonstrate the role N-cadherin plays after RD. RESULTS: N-cadherin was not expressed in the RPE layer of the normal rat retina. After RD, intense immunolabeling of N-cadherin was seen in the RPE cells, the photoreceptors, and the outer limiting membrane (OLM). An increasing number of cytokeratin (CK)-positive cells likely to be RPE cells was found attached to the outer surface of the detached neural retina. Where the retina was reattached, the N-cadherin immunolabeling rapidly decreased. In eyes treated with an N-cadherin antagonist, the retinas appeared thinner than that in eyes without treatment, and the photoreceptor nuclei showed significantly loss. Moreover, CK-positive cells attached to the outer surface of the detached retina were markedly fewer in number. CONCLUSIONS: Increased expression of N-cadherin in the RPE cells, the photoreceptor cells, and the OLM of the retina after RD may contribute to RPE cell migration and photoreceptor survival. These changes could be reversed by retinal reattachment.