[Appropriate selection of multimodal fundus imaging approaches]

With the advancement of science and technology, fundus imaging modalities are rapidly changing and constantly being introduced, playing an important role in the diagnosis and treatment of fundus diseases, as well as in follow-up and prognostic assessment. Clinicians need to update their knowledge and concepts, rationally select a variety of imaging tests for diagnostic and therapeutic purposes, and consider the use of different test protocols in different clinical scenarios. This article summarizes the advantages and limitations of commonly used fundus imaging techniques based on the international research findings and personal clinical experience, with the aim of providing guidance and reference for the rational selection of multimodal fundus imaging approaches in clinical practice.

[Toxic retinopathy caused by veterinary antiparasitic closantel: a case report]

A 32-year-old female patient presented with bilateral vision loss for 2 months following her intake of various antiparasitic drugs, including closantel, a veterinary drug, for a self-perceived intraocular parasitic infection. Swept-source optical coherence tomography revealed diffuse hyperreflectivity between the outer nuclear layer and the retinal pigment epithelium, as well as the largely indistinguishable outer retinal layers. This case was clinically diagnosed with veterinary closantel-induced toxic retinopathy and had a poor visual prognosis after nerve nutrition and circulation improvement therapy due to the long duration of the disease.

Automated Classification of Inherited Retinal Diseases in Optical Coherence Tomography Images Using Few-shot Learning

Objective

To develop a few-shot learning (FSL) approach for classifying optical coherence tomography (OCT) images in patients with inherited retinal disorders (IRDs).

Methods

In this study, an FSL model based on a student-teacher learning framework was designed to classify images. 2,317 images from 189 participants were included. Of these, 1,126 images revealed IRDs, 533 were normal samples, and 658 were control samples.

Results

The FSL model achieved a total accuracy of 0.974-0.983, total sensitivity of 0.934-0.957, total specificity of 0.984-0.990, and total F1 score of 0.935-0.957, which were superior to the total accuracy of the baseline model of 0.943-0.954, total sensitivity of 0.866-0.886, total specificity of 0.962-0.971, and total F1 score of 0.859-0.885. The performance of most subclassifications also exhibited advantages. Moreover, the FSL model had a higher area under curves (AUC) of the receiver operating characteristic (ROC) curves in most subclassifications.

Conclusion

This study demonstrates the effective use of the FSL model for the classification of OCT images from patients with IRDs, normal, and control participants with a smaller volume of data. The general principle and similar network architectures can also be applied to other retinal diseases with a low prevalence.

Analysis of Radial Peripapillary Capillary Density in Patients with Bietti Crystalline Dystrophy by Optical Coherence Tomography Angiography

OBJECTIVE

We wanted to investigate the radial peripapillary capillary (RPC) network in patients with Bietti crystalline dystrophy (BCD).

METHODS

We compared RPC densities in the disk and different peripapillary regions, obtained using optical coherence tomography angiography in 22 patients with BCD (37 eyes) and 22 healthy subjects (37 eyes). The BCD group was then divided into Stage 2 and Stage 3 subgroups based on Yuzawa staging, comparing the RPC densities of the two.

RESULTS

The disk area RPC density was 38.8% ± 6.3% in the BCD group and 49.2% ± 6.1% in the control group ( P < 0.001), and peripapillary region RPC density was significantly lower in the BCD group than in the control group (49.1% ± 4.7% and 54.1% ± 3.0%, respectively, P < 0.001). There were no significant RPC density differences between the tempo quadrant and inside disk of Stages 2 and 3 subgroups; the other areas showed a significantly lower RPC density in Stage 3 than in Stage 2 BCD.

CONCLUSION

The BCD group RPC density was significantly lower than the control group. The reduction of RPC density in the tempo quadrant occurred mainly in the Stage 1 BCD. In contrast, the reduction of RPC density in superior, inferior, and nasal quadrants occurred mainly in Stage 2.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

[Fundus imaging features of purified protein derivative and T-spot positive tubercular serpiginous-like choroiditis]

Objective: To summarize the clinical and fundus imaging features of purified protein derivative and T-spot positive tubercular serpiginous-like choroiditis (PTP-SLC) patients. Methods: This retrospective study consecutively enrolled 13 PTP-SLC patients (21 eyes) in Beijing Tongren Hospital from November 2015 to November 2017. There were 8 males and 5 females with an average age of (45.2±12.1) years. Medical history and results of systemic and ophthalmological examinations, such us fundus autofluorescence photography, optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and indocyanine green angiography, were evaluated. Results: Eight patients had binocular disease with an average interval time of (8.4±7.9) years. The average visual acuity of all patients was 0.3, and 4 patients had a clear history of exposure to tuberculosis. The active lesions in the PTP-SLC patients were homogeneous and creamish-yellow with unclear boundaries. Fundus autofluorescence showed an ill-defined, diffuse hyperautofluorescent zone. OCT showed punctate hyperreflexes between the choroidal stroma, destruction of the outer retinal structure with intraretinal edema and discrete vitreal hyper-reflective spots. FFA showed hypofluorescence in the active lesion at early stage and diffuse hyperfluorescence with leakage. Indocyanine green angiography showed persistent hypofluorescence. Conclusions: PTP-SLC fundus lesions are mainly manifested as homogeneous creamish-yellow lesions with unclear boundaries and high in autofluorescence. The involvement of the choroid and the outer layer of the retina can be observed on OCT. FFA can find more retinal vascular inflammatory changes. It is difficult to distinguish PTP-SLC from serpiginous choroiditis simply based on clinical and epidemiological characteristics. The pathogenic examination of tuberculosis is still the key to differential diagnosis (Chin J Ophthalmol, 2020, 56: 914-919).

[Clinical analysis and laboratory diagnosis of three cases with infantile botulism caused by Clostridium botulinum type B]

Objective: To summarize the clinical characteristics and laboratory diagnostic methods of infant botulism caused by Clostridium botulinum type B. Methods: Clinical data of 3 infants with type B botulism who were admitted to Children's Hospital Affiliated to Capital Institute of Pediatrics from May to November 2018 were retrospectively analyzed. Botulinum toxin was detected in fecal samples or fecal enrichment solution of the patients, and Clostridium botulinum was cultured and isolated from fecal samples. Results: The age of onset of the patients (two boys and one girl) was 3, 3 and 8 months old, respectively. Two cases had the onset in May and one case had the onset in November. There were two cases with mixed feeding and one case with breast feeding. One case's family members engaged in meat processing. All of them were previously healthy. All the children presented with acute flaccid paralysis, cranial nerve involvement and difficult defecation. Two cases had secondary urinary tract infection. Electromyograms of two cases showed that action potential amplitude of the motor nerve were lower than those of their peers. After treatments including intravenous human immunoglobulin, respiratory tract management, urethral catheterization, nasal feeding, etc., three cases recovered completely 2 to 4 months later. Type B botulinum toxin was detected in the fecal diluent of one patient, and the TPGYT enrichment solution and cooked meet medium of the feces of 3 patients, respectively. Clostridium botulinum B was identified from the feces of 3 infants after culture, isolation and purification. Conclusions: Combined with typical clinical manifestations including acute flaccid paralysis, cranial nerve involvement symptoms and difficult defecation examination, infant botulism can be clinically diagnosed. The detection of fecal botulinum toxin and the culture and isolation of Clostridium botulinum are helpful for the diagnosis.

[Clinical characteristics of patients with biopsy-proven sarcoid uveitis]

Objective: To investigate the clinical features of patients with biopsy-proven sarcoid uveitis. Methods: The clinical data of the patients with biopsy-proven sarcoid uveitis who consulted the Ophthalmic Clinic of Beijing Tongren Hospital from February 2012 to February 2020 was retrospectively reviewed and analyzed. All the patients underwent visual acuity test, slit lamp microscopy, indirect ophthalmoscopy, fundus fluorescein angiography (FFA), chest computed tomography (CT) and other auxiliary examinations. Results: A total of 9 patients (18 eyes) (6 females, 3 males) with biopsy-proven sarcoid uveitis were included in the study, with a mean age of (52.6±9.0) years. Based on the modified Scadding classification, there were 2 and 7 cases of Stage Ⅰ and Ⅱ sarcoidosis, respectively. The ocular symptoms were the initial presenting complaints in 6 patients, who had a time from onset to diagnosis of 9.0 (2.6, 20.3) months. Three patients had a history of sarcoidosis. Fever was reported in 2 patients, fatigue in 3 patients, body weight loss in 3 patients, respiratory problems in 5 patients, with bilateral ocular involvement in all the patients. Among the 18 eyes, panuveitis occurred in 10 eyes, posterior uveitis in 4 eyes, anterior uveitis in 4 eyes, mutton fat keratic precipitates (KP) in 10 eyes, granular KP or no obvious KP in 8 eyes, posterior synechia of the iris in 9 eyes, cataract in 8 eyes, inflammatory vitreous opacity in 8 eyes, macular edema in 7 eyes, epiretinal membrane in 6 eyes, retinal vasculitis in 2 eyes, glaucoma in 2 eyes, and optic disc granuloma in 2 eye. Among the 13 eyes whose peripheral ocular fundus was visible, multiple chorioretinal peripheral lesions were found in 5 eyes. Conclusions: Chest CT should be performed in the uveitis patients with older age, female gender, bilateral ocular involvement, the symptom of fever, body weight loss and respiratory problems in time to exclude the sarcoid uveitis. Sarcoid uveitis may presents with granular KP or no obvious KP, and the posterior segment of the eye ball was the most commonly involved area.

Multifactorial effects of hyperglycaemia, hyperinsulinemia and inflammation on bone remodelling in type 2 diabetes mellitus

Bones undergo continuous cycles of bone remodelling that rely on the balance between bone formation and resorption. This balance allows the bone to adapt to changes in mechanical loads and repair microdamages. However, this balance is susceptible to upset in various conditions, leading to impaired bone remodelling and abnormal bones. This is usually indicated by abnormal bone mineral density (BMD), an indicator of bone strength. Despite this, patients with type 2 diabetes mellitus (T2DM) exhibit normal to high BMD, yet still suffer from an increased risk of fractures. The activity of the bone cells is also altered as indicated by the reduced levels of bone turnover markers in T2DM observed in the circulation. The underlying mechanisms behind these skeletal outcomes in patients with T2DM remain unclear. This review summarises recent findings regarding inflammatory cytokine factors associated with T2DM to understand the mechanisms involved and considers potential therapeutic interventions.

Macular Perfusion Changes and Ganglion Cell Complex Loss in Patients with Silicone Oil-related Visual Loss

OBJECTIVE

The aim of this study was to investigate macular perfusion changes and ganglion cell complex (GCC) loss in patients with unexplained visual loss following vitrectomy and silicone oil (SO) tamponade, and to evaluate the correlation between retinal blood flow and GCC loss using optical coherence tomography angiography (OCTA) and optical coherence tomography (OCT).

METHODS

This retrospective study included seven eyes (seven patients) with unexpected visual loss after vitrectomy and SO tamponade. OCTA was used to evaluate the alterations in retinal vessel density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and radial peripapillary capillary plexus (RPCP). OCT was used to measure the thickness of GCC and retinal nerve fiber layer (RNFL). Medical records of patients were reviewed.

RESULTS

Quantitative analysis of OCTA images revealed a significant reduction in SCP VD in the affected eyes compared with the controls (all sections P < 0.05). No difference was found in GCC thickness, but FLV (focal loss volume) and GLV (global loss volume) were significantly higher in the affected eyes (both P < 0.001). SCP VD was inversely correlated with FLV and GLV.

CONCLUSIONS

Silicone oil-related severe visual loss was associated with superficial retinal microvasculature damage and ganglion cell apoptosis.

[Interventional effect of bicyclol on isoniazid-induced liver injury in rats and the expression of glucose-regulated protein 78, and growth arrest and DNA-damage-inducible gene 153]

Objective: To investigate the interventional effect of bicyclol on isoniazid-induced liver injury in rats and the expression of endoplasmic reticulum stress (ERS) protein, glucose regulatory protein 78 (GRP78), and growth arrest and DNA-damage-inducible gene 153(CHOP). Methods: Eighty Wistar rats were randomly divided into control group (8 rats) and model group (72 rats). After 10 days of intragastric administration of isoniazid, the model group rats were randomly divided into treatment group (A), natural recovery group (B), etiological persistence group (C) and etiological persistence plus treatment group (D). Sixteen rats from each group were sacrificed after 1 and 2 weeks of intervention with different methods. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected. Liver pathological morphology was observed. Apoptotic cells were detected by TUNEL assay. ERS protein expression was detected by Western blot. A t-test or randomized block analysis of variance, K-S test and Levene's test were used to analyze the normality and homogeneity of variance. Kruskal-Wallis rank sum test was used for data that did not suit the conditions of t-test and variance analysis. Results: ALT and AST were elevated in the model group, and liver pathological examination showed liver tissue damage. Apoptotic index was higher than control group (7.13% ± 1.55% vs. 0.75% ± 0.71%, Z = -3.411, P < 0.01), and the expression value of ERS protein in model group was significantly higher than control group (GRP78: 1.16 ± 0.30 vs. 0.23 ± 0.05, t = -6.008, P < 0.01; CHOP: 0.98±0.23 vs. 0.20 ± 0.10, t = -6.378, P < 0.01). Serum enzymes, apoptotic index and ERS protein expressions of rats were decreased after treatment with bicyclol, and the pathological damage was eased. Rats in natural recovery group recovered less than the treatment group. Conclusion: Isoniazid-induced liver injury is associated to ERS-related excessive apoptosis and the therapeutic effect of bicyclol on drug-induced liver injury may minimize ERS-induced apoptosis.

[Clinical manifestations and genetics analysis of collagen type Ⅵ-related myopathy caused by variants in COL6A3 gene]

Objective: To summarize the clinical manifestations and determine the molecular etiology for two collagen type Ⅵ-related myopathy pedigrees. Methods: Two spontaneous collagen type Ⅵ-related myopathy patients were admitted to Department of Neurology, Children's Hospital, Capital Institute of Pediatrics in October 2017. Clinical data of probands and their family members were collected and their genomic DNA was obtained for genetic testing. Next generation sequencing was performed and the variants were verified by the Sanger sequencing in the family members. Results: Target region sequencing indicated that the proband of family 1 has carried a heterozygous variant of COL6A3 gene, c.6229G>C(p.Gly2077Arg), and it was de novo variant confirmed by Sanger-sequencing in the family.The patient 1, a 2-year-three-month old boy, was admitted due to motor retardation at birth. He was defined as early severe Ullrich congenital muscular dystrophy. He never achieved independent ambulation, he had onset of symptoms was found at birth, including diffuse muscle weakness, striking distal joint hyperlaxity, proximal contractures, calcaneal protrusion, kyphosis, and hip dislocation. Serum CK level was elevated slightly and EMG showed neurogenic changes. The patient 2, a 7-year-old girl with a limp for 4 years, carried one de novo variant of COL6A3 gene,c.5169_5177del (p.Glu1724_Leu1726del). This variant results in the deletion of amino acids (1724 to 1726) in α3 chain of collagen Ⅵ, which may disturb the function of this protein.She was diagnosed as Bethlem myopathy with a mild phenotype. She had delayed motor milestones and presented with walking on tiptoe, hypotonia, and ithylordosis. The contracture of proximal joints was not very obvious. Serum CK level was normal and EMG showed myogenic changes.Muscle biopsy revealed muscular dystrophy and muscle magnetic resonance imaging of patient 2 showed vastus lateral is a "sandwich" sign. Immunofluorescence staining for COL6A3 chain in the cultured skin fibroblasts from patients 2 showed decreased deposition compared with control. Conclusions: These two patients were diagnosed as spontaneous collagen type Ⅵ-related myopathy and carried different variants of COL6A3 gene. Different in pathogenetic variants could cause different genetic features and different phenotypes. Collagen type Ⅵ- related myopathy patients have various clinical manifestations. Typical phenotypes include muscular dystrophies, proximal contractures, and distal hyperlaxity. Muscle MRI shows diffuse fatty infiltration of gluteus maximus and thigh muscle. The histological staining showed the low level expression of COL6A3 chain. The seventy of phenotype was related to the genotype.

Velocity-space sensitivity of time-of-flight neutron spectrometer at EAST in deuterium plasma

The Time-Of-Flight Enhanced Diagnostics (TOFED) neutron spectrometer with a double-ring structure has been installed at the Experimental Advanced Superconducting Tokamak (EAST) to perform advanced neutron emission spectroscopy diagnosis for deuterium plasma. In order to reduce the random coincidence from the background neutrons and gamma-rays, TOFED was moved outside the experimental hall and placed in the newly-built nuclear diagnostics laboratory in 2017. In this paper, the instrument-specific weight functions of TOFED are derived by taking the instrument response matrix and the radial line of sight in this new layout into consideration. The results show that the instrument is predominantly sensitive to counter-passing particles in the region where time-of-flights < 69.4 ns, while events at higher time-of-flights (corresponding lower neutron energies) are mostly representative of co-passing ions. The instrument-specific weight functions express the relationship between data in a given channel of the spectrum and the velocity space region that contributes to that. The results can be applied for energetic particle physics studies at EAST, in particular to compare data from different diagnostic techniques.

[Senile eye disease screening program in downtown Wenzhou: intraocular pressure]

Objective: To investigate the distribution and related factors of intraocular pressure (IOP) in the screened population aged over 50 years in Wenzhou. Methods: This study included 31 170 community residents aged 50 years or older in Wenzhou undergoing screening from March 2014 to January 2016. Participants underwent a complete ocular examination, including visual acuity, eye-ground photography, slit lamp and standardized measurement of IOP by non-contact tonometry. Subjects who had undergone ocular operation or laser peripheral iridectomy, had glaucoma, corneal or other ocular diseases that could possibly affect the IOP, had an IOP lower than 6 mmHg(1 mmHg=0.133 kPa) and visual acuity less than 0.3, or had monocular IOP values were excluded. The relationship between IOP and various parameters were analyzed. Results: A total of 20 875 subjects (6 902 males and 13 973 females) were enrolled in the current analysis, including 18 677 healthy persons and 2 125 glaucoma suspects, with an average age of (67.3±8.7) years old. The mean IOP (mean±standard deviation) of the healthy population was (13.5±3.0) mmHg (13.4±3.2) mmHg in right eyes and (13.6±3.3) mmHg in left eyes; 2.04% of the left eyes, 1.51% of the right eyes and 2.92% of either eyes of healthy population had an IOP >21 mmHg. The mean IOP in glaucoma suspects was significantly higher than that in the healthy population (P<0.001); 6.78% of the left eyes, 6.16% of the right eyes and 9.65% of either eyes of glaucoma suspects had an IOP >21 mmHg. Men had lower IOPs than women [healthy population: (12.9±3.2) mmHg versus (13.7±3.2) mmHg; P<0.05]. The linear function of IOP (Y) with age (X(1)) and the vertical cup disc ratio (X(2)) was ^Y=15.962-0.043X(1)+0.837X(2)(P<0.05) in the healthy population. Conclusion: The IOP among healthy persons aged over 50 years living in downtown Wenzhou was decreased with age but increased with the vertical cup disc ratio. The IOP in females was higher than that in males. About 3% of the healthy population had an IOP greater than 21 mmHg. (Chin J Ophthalmol, 2018, 54: 586-592).

Optical Coherence Tomography Features of Tuberculous Serpiginous-like Choroiditis and Serpiginous Choroiditis

OBJECTIVE

To investigate optical coherence tomography (OCT) characteristics of tuberculous serpiginous-like choroiditis (Tb-SLC) and serpiginous choroiditis (SC) and to perform OCT to differentiate between these conditions.

METHODS

This retrospective, case-control study examined consecutively enrolled patients with active Tb-SLC or SC. Patients underwent comprehensive ocular examinations and imaging (OCT, color fundus photography, autofluorescence imaging, fluorescein angiography, and indocyanine green angiography). Findings were examined and compared between eyes with SC and Tb-SLC.

RESULTS

Nine patients with active Tb-SLC (14 eyes) and 8 with active SC (12 eyes) were included. The following OCT findings were observed significantly more often in the Tb-SLC group than in the SC group: vitreal hyper-reflective spots [5 Tb-SLC eyes (36%), no SC eyes; P = 0.02], intraretinal edema [11 Tb-SLC eyes (79%), 3 SC eyes (25%); P = 0.01], sub-retinal pigment epithelium (RPE) drusenoid deposits [11 Tb-SLC eyes (79%), 2 SC eyes (17%); P < 0.01], and choroidal granulomas [8 Tb-SLC eyes (57%), 2 SC eyes (17%); P = 0.03]. A hyporeflective, wedge-shaped band was observed more often in the SC group [5 Tb-SLC eyes (36%), 9 SC eyes (75%); P = 0.045] than in the Tb-SLC group. The incidence of other OCT signs did not differ between the groups and included outer nuclear layer hyper-reflection, outer retinal tabulation, and choriocapillaris point-like hyper-reflection.

CONCLUSION

Vitreal hyper-reflective spots, intraretinal fluid, sub-RPE drusenoid deposits, and choroidal granulomas on OCT images may indicate Tb-SLC. Additionally, a hyporeflective, wedge-shaped band may indicate SC. Therefore, OCT is likely helpful in differentiating between Tb-SLC and SC.

Findings of Optical Coherence Tomography Angiography in Best Vitelliform Macular Dystrophy

PURPOSE

To evaluate the vascular anatomy of eyes with Best vitelliform macular dystrophy (BVMD) using optical coherence tomography angiography (OCTA).

METHODS

This retrospective case-control study enrolled 11 consecutive BVMD patients and 13 age-matched healthy participants. Both eyes of each participant were imaged using a macular OCTA scan (3 × 3 mm) by 70-kHz 840-nm spectral-domain OCT. The flow signal was calculated using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm.

RESULTS

Qualitative analysis showed uneven hypo- and hyperintense signal changes at the choriocapillary level in OCTA images of BVMD patients. Quantitative analysis showed significant reductions in the flow density of the superficial vascular layer (whole: 49.2% vs. 53.9%, p < 0.001) and the choriocapillary flow area (5.1 vs. 5.5 mm2, p = 0.02) in BVMD patients compared to controls. The choriocapillary flow area in the postvitelliform group was reduced compared to that of the vitelliform group. There was a statistically significant association between choriocapillary flow area and superficial vascular flow density (p = 0.045), choriocapillary flow area and foveal avascular zone area (p = 0.03).

CONCLUSIONS

Vascular changes in BVMD were apparent in the choriocapillary layer. The changes became more striking in late stages of the disease. OCTA provides useful quantitative measurements for staging and monitoring the progression of BVMD.

[Analysis on the clinical and retinal imaging characteristics of autosomal recessive bestrophinopathy]

Objective: To study the clinical and imaging features of autosomal recessive bestrophinopathy (ARB). Methods: Retrospective study. The clinical and imaging data of 14 participants were analyzed in using autofluorescence (AF), fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT). Ten patients were screened for mutations in BEST1 gene. Results: Retinopathy of ARB were shown as bilaterally and circularly distributed yellow subretinal deposits in the mid-peripheral and posterior retina, which was observed more clearly by AF and FA. The abnormalities were observed as hyperreflection between the sub-retinal pigment epithelium space as well as the subretinal space by SD-OCT imaging. All of the patients showed serous retinal detachment, and 4 of them were found to have intraretinal schisis. Other ocular complications include choroidal neovascularization (CNV) and angle closure glaucoma (ACG) were also found in the patients. Genetic examinations showed that the mutations are compound heterozygous in five patients, homozygous in one patient and heterozygous in only one of the rest 4 patients. Conclusions: The combination of clinical and retinal imaging data may facilitate the diagnosis of ARB. Physicians should be cautious of the vision-threatening complications of the disease. (Chin J Ophthalmol, 2018, 54: 263-269).

Injectable silicone rubber for ocular implantation after evisceration

OBJECTIVE

To investigate the usefulness of addition type liquid silicone rubber (ATLSR) as injectable implant after evisceration to maintain the eyeball volume in an animal experiment.

METHODS

Twelve adult New Zealand white rabbits were included. One eye of each rabbit was randomly selected for evisceration with the fellow eye as control. ATLSR was injected to fill the eyeball socket after evisceration. In vivo observation and photographs were performed up to 24 weeks post-op. Two rabbits were sacrificed respectively at post-operative week 1, 2, 4, 8, 12 and 24. After enucleation, the vertical, horizontal and sagittal diameters of the experimental eyeballs were measured and compared with the control eyes. Histopathological studies were performed to evaluate signs of inflammation.

RESULTS

Cornea remained clear throughout the observation period despite mild epithelial edema and neovascularization. Compared to the control eyes, the experimental eyes were significantly smaller in vertical diameter (17.00±1.17 vs. 17.54±1.11 mm, P<0.001), but larger in sagittal diameter (16.85±1.48 vs. 16.40±1.38 mm, P = 0.008), and had no significant difference in horizontal diameter (17.49±1.53 vs. 17.64±1.21 mm, P = 0.34). Postoperative inflammation was observed at one week after surgery, which peaked at 2-3 weeks, then regressed gradually. At week 12 and week 24, most of the inflammatory cells disappeared with some residual plasma cells and eosinophils.

CONCLUSION

Injectable addition type silicon rubber may be a good choice for ocular implantation after evisceration, maintaining eyeball volume and cosmetically satisfactory when compared to the fellow eye. Spontaneous regression of inflammation implied good biocompatibility for at least 24 weeks.

CONGENITAL CONTRACTILE PERIPAPILLARY STAPHYLOMA WITH RHEGMATOGENOUS RETINAL DETACHMENT

PURPOSE

To describe the occurrence of a congenital contractile peripapillary staphyloma in association with a rhegmatogenous retinal detachment.

METHODS

The clinical course of a 17-year-old patient with a contractile peripapillary staphyloma and undergoing pars plana vitrectomy for repair of an associated retinal detachment was studied.

RESULTS

The left eye showed a peripapillary staphyloma which during the ophthalmoscopical examination revealed contractile movements after the presentation of a light stimulus to either eye. The contraction of the peripapillary staphyloma was not correlated with a Valsalva maneuver, neck venous compression, forced lid closure, or respiratory movements. Because of a retinal detachment involving the inferior, nasal, and temporal retina, best-corrected visual acuity was 20/100. During pars plana vitrectomy under systemic anesthesia, the contractions of the peripapillary staphyloma subsided in the early phase of surgery, and reoccurred at approximately 80 minutes after the start of general anesthesia, when the posterior pole was touched with an aspiration syringe.

CONCLUSION

The etiology of the movements of the congenital peripapillary staphyloma in our patient may include a misbalance between intraocular pressure and orbital cerebrospinal fluid pressure or contractions of extraocular muscles. The observations may give information about the physiology and pathophysiology of the optic nerve head.

Measurement and simulation of the response function of time of flight enhanced diagnostics neutron spectrometer for beam ion studies at EAST tokamak

The 2.5 MeV TOFED (Time-Of-Flight Enhanced Diagnostics) neutron spectrometer with a double-ring structure has been installed at Experimental Advanced Superconducting Tokamak (EAST) to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas. This work describes the response function of the TOFED spectrometer, which is evaluated for the fully assembled instrument in its final layout. Results from Monte Carlo simulations and dedicated experiments with pulsed light sources are presented and used to determine properties of light transport from the scintillator. A GEANT4 model of the TOFED spectrometer was developed to calculate the instrument response matrix. The simulated TOFED response function was successfully benchmarked against measurements of the time-of-flight spectra for quasi-monoenergetic neutrons in the energy range of 1-4 MeV. The results are discussed in relation to the capability of TOFED to perform beam ion studies on EAST.

Neutron emission spectroscopy of DT plasmas at enhanced energy resolution with diamond detectors

This work presents measurements done at the Peking University Van de Graaff neutron source of the response of single crystal synthetic diamond (SD) detectors to quasi-monoenergetic neutrons of 14-20 MeV. The results show an energy resolution of 1% for incoming 20 MeV neutrons, which, together with 1% detection efficiency, opens up to new prospects for fast ion physics studies in high performance nuclear fusion devices such as SD neutron spectrometry of deuterium-tritium plasmas heated by neutral beam injection.

Status of neutron diagnostics on the experimental advanced superconducting tokamak

Neutron diagnostics have become a significant means to study energetic particles in high power auxiliary heating plasmas on the Experimental Advanced Superconducting Tokamak (EAST). Several kinds of neutron diagnostic systems have been implemented for time-resolved measurements of D-D neutron flux, fluctuation, emission profile, and spectrum. All detectors have been calibrated in laboratory, and in situ calibration using ²⁵²Cf neutron source in EAST is in preparation. A new technology of digitized pulse signal processing is adopted in a wide dynamic range neutron flux monitor, compact recoil proton spectrometer, and time of flight spectrometer. Improvements will be made continuously to the system to achieve better adaptation to the EAST's harsh γ-ray and electro-magnetic radiation environment.

Response function of single crystal synthetic diamond detectors to 1-4 MeV neutrons for spectroscopy of D plasmas

A Single-crystal Diamond (SD) detector prototype was installed at Joint European Torus (JET) in 2013 and the achieved results have shown its spectroscopic capability of measuring 2.5 MeV neutrons from deuterium plasmas. This paper presents measurements of the SD response function to monoenergetic neutrons, which is a key point for the development of a neutron spectrometer based on SDs and compares them with Monte Carlo simulations. The analysis procedure allows for a good reconstruction of the experimental results. The good pulse height energy resolution (equivalent FWHM of 80 keV at 2.5 MeV), gain stability, insensitivity to magnetic field, and compact size make SDs attractive as compact neutron spectrometers of high flux deuterium plasmas, such as for instance those needed for the ITER neutron camera.

Strain study of gold nanomaterials as HR-TEM calibration standard

This work presents the use of high resolution electron microscopy (HREM) and geometric phase analysis (GPA) to measure the interplanar spacing and strain distribution of three gold nanomaterials, respectively. The results showed that the {111} strain was smaller than the {002} strain for any kind of gold materials at the condition of same measuring method. The 0.65% of {111} strain in gold film measured by HREM (0.26% measured by GPA) was smaller than the {111} strains in two gold particles. The presence of lattice strain was interpreted according to the growth mechanism of metallic thin film. It is deduced that the {111} interplanar spacing of the gold thin film is suitable for high magnification calibration of transmission electron microscopy (TEM) and the gold film is potential to be a new calibration standard of TEM.

A new phase of phosphorus: the missed tricycle type red phosphorene

We predict a new two-dimensional allotrope of phosphorus, which we call red phosphorene, by restructuring the segments of the previously proposed blue and black phosphorenes. Its atomic and electronic structures as well as the thermodynamic and dynamic stabilities are systematically studied by first-principles calculations. The results indicate that the red phosphorene is dynamically stable and possesses remarkably thermodynamical stability comparable to that of the black one. Because of the sp(3)-hybridization and the formation of a localized lone pair, red phosphorene is a semiconductor with an indirect band gap of about 1.96 eV, which can be effectively modulated by in-plane strains due to its wave-like configuration. We find that the red, black and blue phosphorenes show evident distinction in their layer thicknesses, surface work functions, and possible colors, based on which one can distinguish them in future experiments.

Fibronectin chorused cohesion between endothelial progenitor cells and mesenchymal stem cells of mouse bone marrow

Endothelial progenitor cells (EPCs) could function as niche cells to promote self&mdash;renewal of mesenchymal stem cells (MSCs) in the mouse bone marrow. Cohesion was the basis of the two cells to display their biological functions to each other. In this study, we investigated the mechanism of cohesion between MSCs and EPCs. And demonstrated that fibronectin (FN) in EPCs activated the integrin &#945;5&#946;1 of MSCs and further mediated cell-cell cohesion. Integrin &#945;5&#946;1 and its FN ligand played critical roles not only in single&mdash;cell line adhesion, but also in adhesion between stem and niche cells. This novel finding is important to understand the cross&mdash;talk between MSCs and their niche cells.

Design of the radiation shielding for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

A radiation shielding has been designed to reduce scattered neutrons and background gamma-rays for the new double-ring Time Of Flight Enhanced Diagnostics (TOFED). The shielding was designed based on simulation with the Monte Carlo code MCNP5. Dedicated model of the EAST tokamak has been developed together with the emission neutron source profile and spectrum; the latter were simulated with the Nubeam and GENESIS codes. Significant reduction of background radiation at the detector can be achieved and this satisfies the requirement of TOFED. The intensities of the scattered and direct neutrons in the line of sight of the TOFED neutron spectrometer at EAST are studied for future data interpretation.

Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST

The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/Ep) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed.

Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

Data acquisition system with pulse height capability for the TOFED time-of-flight neutron spectrometer

A new time-of-flight neutron spectrometer TOFED has been constructed for installation at Experimental Advanced Superconducting Tokamak. A data acquisition system combining measurements of flight time and energy from the interaction of neutrons with the TOFED scintillators has been developed. The data acquisition system can provide a digitizing resolution better than 1.5% (to be compared with the >10% resolution of the recoil particle energy in the plastic scintillators) and a time resolution <1 ns. At the same time, it is compatible with high count rate event recording, which is an essential feature to investigate phenomena occurring on time scales faster than the slowing down time (≈100 ms) of the beam ions in the plasma. Implications of these results on the TOFED capability to resolve fast ion signatures in the neutron spectrum from EAST plasmas are discussed.

Monte Carlo simulation of a Bonner sphere spectrometer for application to the determination of neutron field in the Experimental Advanced Superconducting Tokamak experimental hall

To assess the neutron energy spectra and the neutron dose for different positions around the Experimental Advanced Superconducting Tokamak (EAST) device, a Bonner Sphere Spectrometer (BSS) was developed at Peking University, with totally nine polyethylene spheres and a SP9 (3)He counter. The response functions of the BSS were calculated by the Monte Carlo codes MCNP and GEANT4 with dedicated models, and good agreement was found between these two codes. A feasibility study was carried out with a simulated neutron energy spectrum around EAST, and the simulated "experimental" result of each sphere was obtained by calculating the response with MCNP, which used the simulated neutron energy spectrum as the input spectrum. With the deconvolution of the "experimental" measurement, the neutron energy spectrum was retrieved and compared with the preset one. Good consistence was found which offers confidence for the application of the BSS system for dose and spectrum measurements around a fusion device.

Tuberculous uveitis in China

PURPOSE

To assess tuberculous uveitis in Chinese patients.

METHODS

The hospital-based observational case series study included patients who attended a third-referral hospital and presented with chronic and recurrent uveitis without primarily detected aetiology. The patients underwent the tuberculin skin test (TST) and/or interferon gamma release test (IGRA). Patients with positive test results received standard antituberculous therapy. Patients who responded to the therapy and did not show recurrence of uveitis in the follow-up period were diagnosed as tuberculous uveitis and formed the study group. The remaining patients were diagnosed as non-tuberculous uveitis and formed the control group. The clinical characteristics were compared between both groups.

RESULTS

The study group with tuberculous uveitis included 46 patients and the non-tuberculous group 38 patients. Multifocal choroiditis [n = 9 (20%) versus n = 1(3%); p = 0.04] and retinal vasculitis [n = 25(54%) versus 8 = (21.1%); p = 0.002] were significantly more common in the study group. Of 25 patients with retinal vasculitis in the study group, 11 patients (44%) additionally showed choroiditis lesions, compared with only one (13%) of eight patients in the control group (p = 0.01). In multivariate regression analysis, multifocal choroiditis [odds ratio (OR): 32.1], choroidal granuloma (OR: 21.4) and retinal vasculitis (OR: 11.2) were independent predictors of tubercular uveitis.

CONCLUSIONS

About 50% of a group of 84 patients with primarily unexplained chronic posterior uveitis had tuberculosis and showed multifocal choroiditis, choroidal granuloma and retinal vasculitis. These features had a high predictive value for the diagnosis of tuberculous uveitis. Tuberculosis is an important part in the differential diagnosis of unexplained uveitis.

Peripapillary intrachoroidal cavitations. The Beijing eye study

Purpose

To assess prevalence, size and location of peripapillary intrachoroidal cavitations (PICCs) and their associations in a population-based sample. .

Methods

The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6±9.8 years (range:50-93 years). A detailed ophthalmic examination included enhanced depth imaging of the choroid by spectral-domain optical coherence tomography and fundus photography. PICCs were defined as triangular thickening of the choroid with the base at the optic disc border and a distance between Bruch´s membrane and sclera of ≥200μm. Parapapillary large choroidal vessels were excluded.

Results

Out of 94 subjects with high myopia (refractive error <-6.0 diopters or axial length >26.5mm in right eyes), OCT images were available for 89 (94.7%) participants. A PICC was detected in 15 out of these 89 highly myopic subjects (prevalence:16.9±4.0%) and in none of hyperopic, emmetropic or medium myopic subgroups each consisting of 100 randomly selected subjects. Mean PICC width was 4.2±2.3 hours (30°) of disc circumference and mean length was 1363±384μm. PICCs were located most frequently (40%) at the inferior disc border. On fundus photos, a typical yellow-orange lesion was found in 8 (53%) eyes with PICCs. In binary regression analysis, presence of PICCs was significantly associated with optic disc tilting (P=0.04) and presence of posterior staphylomata (P=0.046).

Conclusions

Prevalence of PICCs in the adult Chinese population was 16.9±4.0% in the highly myopic group, with no PICCs detected in non-highly myopic eyes. PICCs were located most frequently at the inferior optic disc border. Only half of the PICCs detected on OCT images showed a yellow-orange lesion on fundus photos. Presence of PICC was significantly associated only with an increased optic disc tilting and presence of posterior staphylomata, while it was not associated with axial length, refractive error or other ocular or systemic parameters.

Vogt-Koyanagi-Harada disease and fungal meningitis

PURPOSE

To describe a patient who initially presented with features of Vogt-Koyanagi-Harada disease and who eventually demonstrated symptoms of mycotic meningitis.

METHODS

An 18-year-old immunocompetent boy showed a disseminated uveitis with patchy thickening of the posterior choroid. A clinical neurologic examination and a microbiological assessment revealed neck stiffness as well as pleocytosis, increased protein content, a decreased concentration of glucose and chloride, and cryptococcal fungi in the cerebrospinal fluid. It led to the diagnosis of cryptococcal meningitis.

RESULTS

Antifungal therapy was initiated and given for 2 months. After bilateral retrobulbar injections of 2.5 mg of dexamethasone and 20 mg of triamcinolone acetonide, choroidal edema regressed and visual acuity increased from 0.4 to 1.0 at 3 weeks after start of therapy. Microbiological examination of cerebrospinal fluid samples taken 30 days later was unremarkable. Ophthalmoscopy showed some fine pigment clumping and depigmentation in the macula.

CONCLUSION

According to the International Nomenclature Committee for Vogt-Koyanagi-Harada diagnosis, the patient was diagnosed with incomplete Vogt-Koyanagi-Harada because he had not suffered any ocular trauma, had not undergone ocular surgery, and presented with bilateral multifocal choroiditis accompanied by signs of meningitis without skin abnormalities. Because skin changes can occur months to years after the initial symptoms, the patient may eventually fulfill the criteria for complete Vogt-Koyanagi-Harada disease.

Hyperglycemic effects of a periocular dexamethasone injection in diabetic patients after vitreoretinal surgery

OBJECTIVE

To examine the hyperglycemic effects of periocular dexamethasone injection in type 2 diabetic patients after vitreoretinal surgery (VRS).

METHODS

This was a retrospective non-randomized controlled trial. Twenty consecutive hospitalized patients with type 2 diabetes and ocular inflammatory reaction after VRS were enrolled in this study. Ten patients received 2.5 mg dexamethasone and 10 patients received 5 mg dexamethasone. Fourteen consecutive type 2 diabetic patients without ocular inflammatory reaction after VRS were used as control group. We measured fasting blood glucose (FBG) and at 2 h after each meal (post prandial glucose, PBG; 09:00, 13:00, and 19:00 h) after periocular dexamethasone injection. Differences among three groups were determined by q tests.

RESULTS

The PBG levels in both dexamethasone-treated groups started to increase within 5 h after injection (i.e., PBG at 13:00 h), and were significantly increased at 19:00 h after injection (P<0.05). BG levels were almost 2-fold higher than at baseline and compared with the control group. The BG values declined gradually by 24 h to 48 h after injection. There were no differences in BG levels between the two dexamethasone-treated groups (P>0.05), except for PBG at 19:00 h on day 2 after injection (P<0.05).

CONCLUSION

Periocular dexamethasone injection can cause transient hyperglycemia in diabetic patients after VRS. BG monitoring should be performed following such injection.

Risk factors for diabetic retinopathy in a rural Chinese population with type 2 diabetes: the Handan Eye Study

PURPOSE

To describe risk factors associated with diabetic retinopathy (DR) in a population-based sample of rural Chinese with type 2 diabetes.

METHODS

The Handan Eye Study is a population-based cross-sectional study surveyed 6830 Chinese people aged 30+ years from 13 randomly selected villages in 2006-2007. All participants underwent a standardized interview and extensive examinations including ophthalmologic and systemic conditions. Diabetic retinopathy was graded from fundus photographs according to the modified Early Treatment Diabetic Retinopathy Study classification system. Logistic regression models were used to assess risk factors associated with DR.

RESULTS

Of 7577 eligible persons, 6830 (90.4%) participated, of which 5597 (81.9%) had fasting plasma glucose (FPG) data. There were 387 (6.9%) participants with diabetes, and 368 (95.1%) had gradable fundus photographs. The age-standardized prevalence of DR was 43.1%. In multivariable-adjusted logistic regression models for all diabetic participants, independent risk factors for DR were longer duration of diabetes (odds ratio [OR] 3.07, 95% confidence interval [CI] 1.94, 4.85, per 5 years of duration), higher FPG levels (OR 1.17; 95% CI: 1.08, 1.27, per mmol/l increase) and higher systolic blood pressure (OR 1.22; 95% CI: 1.08, 1.37, per 10 mmHg increase). For newly diagnosed diabetes, the only significant factor of DR was higher FPG levels (OR 1.17; 95% CI: 1.05, 1.29, per mmol/l increase).

CONCLUSIONS

In rural Chinese persons with diabetes, longer diabetes duration, hyperglycaemia and elevated blood pressure are risk factors for DR. These findings underscore the importance of controlling classic risk factors for DR in developing countries, where diabetes prevalence is increasing.

A novel compact design of calibration equipment for gas and thermal sensors

A novel design of calibration equipment has been developed for static and dynamic calibrations of gas and thermal sensors. This system is cheap, compact, and easily adjustable, which is also combined with a plasma surface modification source for tailoring the surface of sensors to ensure the sensitivity and selectivity. The main advantage of this equipment is that the operating temperature, bias voltage, types of plasma source (for surface modification), types of feeding gases, and gas flow rate (for calibrations), etc., can be independently controlled. This novel system provides a highly reliable, reproducible, and economical method of calibrations for various gas and thermal sensors.

Suppression of nuclear factor-kappaB activity in Kupffer cells protects rat liver graft from ischemia-reperfusion injury

OBJECTIVE

The objective of this study was to investigate the protective effect and mechanisms of nuclear factor (NF)-kappaB decoy oligodeoxynucleotides (ODN) on rat liver grafts following ischemia-reperfusion injury (IRI).

METHODS

Animals were randomly divided into 3 groups (n = 8): control ischemia-reperfusion (IR) and decoy ODN groups; in the last cohort donor grafts were transfected with 120 microg NF-kappaB decoy ODN before procurement. Following 2 hours of reperfusion, NF-kappaB binding activity was detected in isolated Kupffer cells (KCs) using electrophoretic mobility shift assays (EMSA). Tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 messenger RNA (mRNA) expressions were analyzed using reverse transcriptase polymerase chain reaction (RT-PCR) methods. Liver tissue and blood serum were collected for histopathologic examination and liver function test, respectively.

RESULTS

The NF-kappaB binding activity, TNF-alpha and IL-6 mRNA expression as well as serum ALT and total bilirubin levels were significantly increased compared with the control group following reperfusion (P < .01). A large number of hepatocytes showed degeneration and necrosis. However, these indices were significantly ameliorated among the decoy ODN group (P < .01) with preserved hepatic lobule architecture.

CONCLUSION

KCs NF-kappaB activation following reperfusion plays an important role in IRI after liver transplantation. The decoy strategy showed an apparent effect to suppress NF-kappaB activation and inhibit production of downstream cytokines, thereby protecting liver grafts from IRI.

Retinopathy in persons without diabetes: the Handan Eye Study

PURPOSE

To describe the prevalence and associations of retinopathy in a population-based nondiabetic sample of rural Chinese.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

We included 6830 Han Chinese aged > or =30 years from 13 villages of Yongnian County, Handan City, Hebei Province, China.

METHODS

All participants underwent a standardized interview and extensive examinations including retinal photography, measurement of blood pressure (BP) and fasting plasma glucose (FPG). Diabetes mellitus was defined as either FPG > or = 7.0 mmol/l, use of diabetic medication or a physician diagnosis of diabetes. Photographic grading of retinopathy followed the modified Early Treatment Diabetic Retinopathy Study classification system. Logistic regression models were used to assess associations of retinopathy.

MAIN OUTCOME MEASURES

Any retinopathy.

RESULTS

The prevalence of retinopathy among participants without diabetes was 13.6% (95% confidence interval [CI], 12.6-14.6%). The age and gender standardized prevalence of retinopathy in the Chinese adult population (aged 30+ years) without diabetes was estimated to be 12.1% (95% CI 11.1-12.9%). Independent risk factors associated with retinopathy were age (odds ratio [OR], 1.02 ; 95% CI 1.01-1.03 per year increase), male gender (male vs. female, OR 1.27; 95% CI 1.08-1.49), higher FPG (OR 1.30; 95% CI 1.11-1.53 per mmol/l increase), higher systolic BP (OR 1.15; 95% CI 1.05-1.27 per 10 mmHg increase) and higher diastolic BP (OR 1.16; 95% CI 1.09-1.22 per 10 mmHg increase).

CONCLUSIONS

Retinopathy was common among rural Chinese adults without diabetes. Its association with FPG and BP suggests that early microvascular damage is occurring at "high normal" levels of blood glucose and BP.

Oval-like hollow intensity distribution of tightly focused femtosecond laser pulses in air

The propagation of a tightly focused femtosecond laser pulse in air has been investigated. Unlike long-distance self-guided propagation of short laser pulses, a novel oval-like hollow distribution of the laser intensity is observed in the experiments and reproduced by the numerical simulations. The formation of the hollow structures can be explained by the interplay between ionization-induced refraction and Kerr self-focusing.

Laser-induced chorioretinal venous anastomosis using combined lasers with different wavelengths

AIM

To evaluate the effectiveness of combined lasers with different wavelengths in creating chorioretinal venous anastomosis (CRVA) in nonischaemic central retinal vein occlusion (CRVO).

METHODS

In this retrospective, noncomparative, consecutive case series, records of all patients with a diagnosis of nonischaemic CRVO who underwent combined laser treatment to induce CRVA and who were followed-up for 6 months or longer were reviewed.

RESULTS

Records of 85 patients (85 eyes) were analysed. These patients were divided into two groups. In group 1 (24 cases, 24 eyes), combined lasers with two different wavelengths (argon blue-green laser combined with Nd-YAG laser were used. In group 2 (61 cases, 61 eyes), combined lasers with three different wavelengths (argon blue-green laser combined with krypton red laser and Nd-YAG laser) were used. Functional anastomosis formed in 13 out of 24 eyes (54%) in group 1 and 47 out of 61 eyes (77%) in group 2. In patients with successful anastomosis, visual acuity improved for two or more lines in 49 out of 60 eyes (82%), with the remaining eyes undergoing no change. There were no serious complications.

CONCLUSION

The use of three laser wavelengths results in the creation of laser anastomosis and the success rate may be higher than when using two wavelengths alone.

Energetic electrons emitted from ethanol droplets irradiated by femtosecond laser pulses

We investigate the angular distribution and the energy spectrum of hot electrons emitted from ethanol droplets irradiated by linearly polarized 150-fs laser pulses at an intensity of 10(16) W/cm(2). Two hot electron jets symmetrically with respect to the laser propagation direction are observed within the polarization plane. This is due to the spherical geometry of droplets in the intense laser field. The maximum energy of the hot electrons is found to be more than 600 keV. Particle-in-cell simulations suggest that the resonance absorption is the main mechanism for hot electron generation.

Blast waves produced by interactions of femtosecond laser pulses with water

The behaviors of the blast waves produced by femtosecond laser-water interactions, and the blast waves induced by laser self-focusing in air, have been investigated using optical shadowgraphy at a maximum intensity of 1 x 10(16) W/cm(2). The temporal evolution of the blast wave launched by the water plasma can be described by a planar blast wave model including source mass. An aneurismlike structure, due to the quick propagation inside a hollow channel formed by laser self-focusing, is observed. The expansion of the channel in air is found to agree with a cylindrical self-similar blast wave solution.

Spatial distribution of high-energy electron emission from water plasmas produced by femtosecond laser pulses

High energy electrons emitted by water plasmas produced by a single or a multiple laser pulse are investigated. The multipulse mode greatly enhances the generation and the temperature of hot electrons. Directional emission of high energy electrons over 25 keV is observed in two symmetric directions with respect to the laser axis and at 46 degrees from the directions of the laser electric field. Two-dimensional particle-in-cell simulations reproduce well the experimental results and indicate that the acceleration mechanism of the high energy electrons is due mainly to the resonance absorption at the edge of the spherical droplets formed by the leading pulse.

Propagation of hot electrons through high-density plasmas

Propagation of hot electrons through high-density plasmas generated by femtosecond laser pulses is investigated using three types of target configurations: Al-coated glass, Al and glass separated by a vacuum gap, and Al foil alone. Collimated ionization tracks lasting for 60 ps and extending 150-300 microm in length and 8 microm in cross section are observed via optical probing. For the Al-foil-alone target, a narrow plasma jet is formed at the rear surface in line with the laser. The collimation of the hot electrons may be attributed to a strong self-generated magnetic field in the target.

The use of the L-plastin promoter for adenoviral-mediated, tumor-specific gene expression in ovarian and bladder cancer cell lines

A 2.4-kb truncated L-plastin promoter was inserted either 5' to the LacZ gene (Ad-Lp-LacZ) or 5' to the cytosine deaminase (CD) gene (Ad-Lp-CD) in a replication-incompetent adenoviral vector backbone. Infectivity and cytotoxicity experiments with the LacZ and CD vectors suggested that the L-plastin promoter-driven transcriptional units were expressed at much higher levels in explants of ovarian cancer cells from patients and in established ovarian or bladder cancer cell lines than they were in normal peritoneal mesothelial cells from surgical specimens, in organ cultures of normal ovarian cells, or in the established CCD minimal deviation fibroblast cell line. Control experiments showed that this difference was not attributable to the lack of infectivity of the normal peritoneal cells, the normal ovarian cells, or the minimal deviation CCD fibroblast cell line, because these cells showed expression of the LacZ reporter gene when exposed to the replication-incompetent adenoviral vector carrying the cytomegalovirus (CMV)-driven LacZ gene (Ad-CMV-LacZ). The Ovcar-5 and Skov-3 ovarian cancer cell lines exposed to the Ad-Lp-CD adenoviral vector were much more sensitive to the prodrug 5-fluorocytosine (5FC), which is converted from the 5FC prodrug into the toxic chemical 5-fluorouracil, than was the CCD minimal deviation fibroblast cell line after exposure to the same vector. A mouse xenograft model was used to show that the Ad-Lp-CD vector/5FC system could prevent engraftment of ovarian cancer cells in nude mice. Finally, injection of the Ad-Lp-CD vector into s.c. tumor nodules generated a greater reduction of the size of the tumor nodules than did injection of the Ad-CMV-LacZ vectors into tumor nodules. The Ad-Lp-CD vectors were as suppressive to tumor growth as the Ad-CMV-CD vectors. These results suggest that an adenoviral vector carrying the CD gene controlled by the L-plastin promoter (Ad-Lp-CD) may be of potential value for the i.p. therapy of ovarian cancer.

[Study on the differentiation and apoptosis of HL-60 cell line induced by Puerarin]

OBJECTIVE

To investigate the differentiation of HL-60 cells induced by different doses of Purerarin(PR) comparing with all-trans retinoic acid(ATRA) and to see if PR can induce apoptosis of HL-60 cells.

METHODS

Cell differentiation was analyzed by NBT reduction, the ratio of NBT/MTT and CD11b, apoptosis by morphology, DNA electrophoresis, and flow cytometry(FCM).

RESULTS

80 micrograms.ml-1, 160 micrograms.ml-1, 320 micrograms.ml-1 PR could induce differentiation of HL-60 cells, no significant difference was observed between the cells treated with 1 mumol.L-1 ATRA and 320 micrograms.ml-1 PR. Treated with 320 micrograms.ml-1, 640 micrograms.ml-1 PR, HL-60 cells exhibited a morphological characteristic of apoptosis and typical DNA ladder on gel electrophoresis. FCM analysis showed that PR could interfere with cell cycle in HL-60 cells, with a increased ratio of sub-G1 in HL-60 cells.

CONCLUSION

PR exerts effect on differentiation and induces apoptosis in HL-60 cells.