A boy with amblyopia and familial exudative vitreoretinopathy harboring a new mutation of LRP5 and OPA1: A case report.

Background: The study aimed to report a boy with familial exudative vitreoretinopathy and amblyopia harboring a new mutation of the LRP5 and OPA1 gene abnormality. Case presentation: A 9-year-old boy presented with a 2-year history of deteriorating visual acuity in the right eye. His best-corrected visual acuity was -7.00/-1.75 × 100 = 0.3 in the right eye and -2.50/-1.50 × 170 = 0.8 in the left eye. Two autosomal dominant gene mutation sites were identified in the patient: LRP5 (c.2551C > T, p.His851Tyr) from his father and OPA1 (c.565G > A, p.Glu189Lys) from his mother. Interestingly, his fraternal twin brother harbored no abnormal gene mutations, and his eye tests were normal. Conclusion: This case expands the spectrum of LRP5 gene mutations among Chinese patients with familial exudative vitreoretinopathy, and it is the first time to report a patient harboring both LRP5 and OPA1 gene mutations having anisometropic amblyopia and strabismus as the primary manifestations. These four family members exhibited individual heterogeneity of phenotypes and genotypes associated with hereditary ophthalmopathy. A comprehensive analysis of clinical phenotypes and genotypes provides clinical clues for improving the level of clinical and genetic diagnoses and a deeper understanding of the disease.

A Semi-active Exoskeleton Based on EMGs Reduces Muscle Fatigue When Squatting.

In dynamic manufacturing and warehousing environments, the work scene made it impossible for workers to sit, so workers suffer from muscle fatigue of the lower limb caused by standing or squatting for a long period of time. In this paper, a semi-active exoskeleton used to reduce the muscle fatigue of the lower limb was designed and evaluated. (i) Background: The advantages and disadvantages of assistive exoskeletons developed for industrial purposes were introduced. (ii) Simulation: The process of squatting was simulated in the AnyBody.7.1 software, the result showed that muscle activity of the gluteus maximus, rectus femoris, vastus medialis, vastus lateralis, vastus intermedius, and erector spinae increased with increasing of knee flexion angle. (iii) Design: The exoskeleton was designed with three working modes: rigid-support mode, elastic-support mode and follow mode. Rigid-support mode was suitable for scenes where the squatting posture is stable, while elastic-support mode was beneficial for working environments where the height of squatting varied frequently.The working environments were identified intelligently based on the EMGs of the gluteus maximus, and quadriceps, and the motor was controlled to switch the working mode between rigid-support mode and elastic-support mode. In follow mode, the exoskeleton moves freely with users without interfering with activities such as walking, ascending and descending stairs. (iv) Experiments: Three sets of experiments were conducted to evaluate the effect of exoskeleton. Experiment one was conducted to measure the surface electromyography signal (EMGs) in both condition of with and without exoskeleton, the root mean square of EMGs amplitude of soleus, vastus lateralis, vastus medialis, gastrocnemius, vastus intermedius, rectus femoris, gluteus maximus, and erector spinae were reduced by 98.5, 97.89, 80.09, 77.27, 96.73, 94.17, 70.71, and 36.32%, respectively, with the assistance of the exoskeleton. The purpose of experiment two was aimed to measure the plantar pressure with and without exoskeleton. With exoskeleton, the percentage of weight through subject's feet was reduced by 63.94, 64.52, and 65.61% respectively at 60°, 90°, and 120° of knee flexion angle, compared to the condition of without exoskeleton. Experiment three was purposed to measure the metabolic cost at a speed of 4 and 5 km/h with and without exoskeleton. Experiment results showed that the average additional metabolic cost introduced by exoskeleton was 2.525 and 2.85%. It indicated that the exoskeleton would not interfere with the movement of the wearer Seriously in follow mode. (v) Conclusion: The exoskeleton not only effectively reduced muscle fatigue, but also avoided interfering with the free movement of the wearer.

MR temperature imaging using PRF phase difference and a geometric model-based fat suppression method.

BACKGROUND: Because protons in fat do not exhibit a temperature-dependent frequency shift, proton resonance frequency shift (PRFS)-based MR thermometry always suffers from disturbances due to the presence of fats or lipids. OBJECTIVE: A new fat suppression method for PRFS-based MR thermometry is proposed to obtain accurate variation of phase angle. METHODS: Similar to the approach of separating fat and water with the two-point Dixon technique, we first scan a complex MR image for reference and then scan another complex image varying with temperature at the same TE point. Based on the conventional PRFS method, we use geometric relationships to remove the effect of fat on the variation of the phase angle. RESULTS: Two phantoms with different water-to-fat ratios are involved in the temperature mapping test. Experimental results show that the temperature images of two phantoms are approximated under the same conditions. CONCLUSIONS: The proposed fat suppression method is simple and effective for PRFS-based MR thermometry.

[Development and application of a genome specific PCR marker for Haynaldia villosa].

Random amplified polymorphic DNA (RAPD) analysis was performed on common wheat Chinese Spring, H. villosa, addition lines of H. villosa chromosome in CS, substitution line 3V of H. villosa chromosome in Triticum aestivum. A genome specific polymorphic DNA segment from H. villosa, OPF02757, was obtained. On the basis of cloning and sequencing of OPF02757, two PCR primers were designed and a genome specific PCR marker for H. villosa was established. The PCR marker including 677 bp was localized on all the seven pairs of H. villosa chromosomes. The result of PCR amplification by the primers indicated that there was a specific band of 677 bp in the materials containing H. villosa Chromosome such as T. aestivum-H. villosa addition, T. aestivum-H. villosa substitution, T. aestivum-H. villosa amphidiploid, T. durum-H. villosa amphidiploid and H. villosum from different accessions, and there was no specific band of 677 bp if the materials did not contain H. villosa chromosome, such as T. aestivum, T. durum, Secale cereale, Hordeum vulgare, Thinopyrum elongatum, Thinopyrum intermedium. Therefore, the PCR maker of 677 bp is specific to H. villosa genome, and could be used as molecular marker for detection of chromosomes of H. villosa in wheat.

[Molecular identification of wheat granule bound starch synthase gene polymorphism].

Fourteen wheat cultivars were identified into six types of Wx proteins combinations using 6% SDS-PAGE. PCR primers were designed according to the three Wx genes sequences and their mutants, respectively. A 327 bp-band was amplified from the Wx-A1 mutant,while the band was absent for the normal alleles at the Wx-A1 locus,as well as the presence or absence of a 187 bp PCR fragment at the Wx-B1 locus and a 700 bp PCR fragment at the Wx-D1 locus, respectively, corresponding to the normal and mutant alleles. Compared with the former studies, shorter and more different PCR products at three loci, amplified by the primers designed for Wx-B1 gene can be separated in 2% agarose gel, which enables screening breeding lines for noodle use faster and effectively.

[Identification, mapping, and application of a chromosome-specific RAPD marker from Haynaldia villosa].

Random amplified polymorphic DNA (RAPD) analysis was performed on common wheat of Chinese Spring, addition lines of H. villosa chromosome in CS and H. villosum from different accessions with 100 random 10-base primers. A chromosome-specific polymorphic DNA segment for H. villosa, OPF02(750), was obtained from all addition lines of H. villosa chromosome in CS and H. villosum which belong to different accessions. The result amplified by primer OPF02 of all addition lines of H. villosa chromosome in CS indicated that all the seven pairs of H. villosa chromosomes contain OPF02(750) segment. There was no OPF02(750) in all Triticum aestivum and T. durum tested. Using OPF02, We confirmed that NAU302, an addition line of H. villosa chromosome 3V, had lost its chromosome 3V of H. villosa. Therefore, OPF02(750) is specific to chromosomes of H. villosa, and could be used as a molecular marker for detection of chromosome of H. villosa in wheat.

Clinical features and linkage analysis for a Chinese family with autosomal dominant central areolar choroidal dystrophy.

BACKGROUND: A Chinese family with autosomal dominant central areolar choroidal dystrophy (CACD) was identified. The purpose of this study was to collect the clinical findings from the family and to identify the genetic entity by linkage analysis. METHODS: Forty-three individuals from 3 generations of the family underwent ophthalmologic examinations, including best-corrected visual acuity, examination of the anterior segments, and inspection of the ocular fundus after pharmacologic mydriasis. Affected family members further underwent color vision test, color fundus photography, fluorescein angiography, automated perimetry, and electroretinography. The family was followed up for 30 months. Peripheral venous blood or buccal swabs were collected from each family member and genomic DNA was extracted. Linkage analysis was performed for candidate genes or loci using microsatellite markers. RESULTS: Seven family members in 3 continuous generations were diagnosed as having autosomal dominant CACD. The family showed progressive development of the disease, affecting both male and female. Age of onset of visual disturbances varied between 11 and 50 years. Phenotypic variability among affected individuals was apparent and ranged from relatively normal-appearing fundus with mild parafoveal pigment mottling to geographic atrophy of the macula. Fluorescein angiography showed hyperfluorescent parafoveal changes in early stage or well-demarcated area of chorioretinal atrophy with enhanced visibility of the residual underlying choroidal vessels in the late stage. Peripheral retina and visual fields were normal in affected individuals. Electroretinogram showed normal or mild reduction in the photopic amplitude. Eight candidate genes (STGD4, RCD1, peripherin/RDS, GUCA1A, RIMS1, UNC119, GUCY2D, and AIPL1) and two genetic loci (4p15.2 - 16.3, and 17p13) were excluded to be responsible for the disease by linkage analysis. CONCLUSIONS: The clinical findings of this Chinese family with CACD shared similarities with previously reported families of other ethnicities. Linkage analysis excluded the known genes and genetic loci, indicating genetic heterogeneity of the disease.