[Clinical characteristics and surgical outcomes in pediatric progressive restrictive strabismus]

Objective: To investigate the clinical features, imaging manifestations, histopathological characteristics, and surgical outcomes in pediatric progressive restrictive strabismus. Methods: A retrospective case series study was conducted, including data from 9 cases (9 eyes) of pediatric progressive restrictive strabismus treated at Tianjin Eye Hospital from June 2017 to October 2022. The study compared the degree of globe protrusion in both eyes, changes in eyelid fissure height during internal and external rotation in the primary gaze, summarized clinical characteristics, and analyzed intraoperative conditions, surgical outcomes and postoperative histopathological results of strabismus correction surgery. Statistical analysis was performed using Wilcoxon signed-rank test and Friedman two-way analysis of variance. Results: All 9 cases involved unilateral onset, with 4 males and 5 females. Three cases affected the right eye, and six affected the left eye. Onset age ranged from 2 to 40 months. The degree of globe protrusion in the affected eyes was 13.00 (12.00, 13.00) mm for the right eye and 12.00 (12.00, 13.50) mm for the left eye, with no statistically significant difference (Z=-1.00, P=0.317). There were no significant changes in eyelid fissure height during internal rotation [8.00 (7.25, 8.00) mm], primary gaze [7.50 (7.00, 8.00) mm], and external rotation [8.00 (7.75, 8.00) mm] in the affected eyes (χ²=1.00, P=0.607). No apparent abnormalities were observed in head CT or MRI scans, serum, or immunological tests. However, orbital CT or MRI scans indicated thickening of different extraocular muscle bellies. Six out of nine cases underwent strabismus correction surgery, and postoperative examination revealed restriction in eye movement despite achieving orthophoria in the primary gaze. Tissue pathology of three cases showed increased collagen fiber proliferation in one, scattered bundles of smooth muscle fibers amid diffuse collagen fiber proliferation in another, and abnormal proliferation of striated muscle fibers with varying diameters, increased paired box (PAX)7-positive satellite cells expressing slow muscle myosin in the third case. Conclusions: Pediatric progressive restrictive strabismus presents with restrictive changes, without significant alterations in globe protrusion and eyelid fissure height. Imaging examinations reveal thickening of the extraocular muscle bellies in the affected eye. Although strabismus correction surgery improves eye position, postoperative eye movement remains restricted. Histopathological findings in some cases show abnormal proliferation of skeletal muscle fibers or collagen fibers.

[Significance of accurately interpreting the Bielschowsky tilt test in the differential diagnosis of superior oblique muscle paralysis]

Superior oblique muscle paralysis is a common type of vertical rotatory strabismus with various subtypes. Regardless of the subtype, the Bielschowsky tilt test plays a crucial role in the diagnosis of superior oblique muscle paralysis and is often considered a significant criterion for diagnosis and differential diagnosis. However, the sensitivity and specificity of the Bielschowsky tilt test for diagnosing superior oblique muscle paralysis are not 100% due to the mechanism involved. The test is not solely based on extraocular muscle imbalance but also involves reflex pathways of the vestibular system and central nervous system. Consequently, lesions affecting corresponding areas may yield positive results in the Bielschowsky tilt test. Additionally, vestibular and central nervous system lesions can also cause strabismus, leading to a lack of one-to-one correspondence between a positive Bielschowsky tilt test and superior oblique muscle paralysis. Therefore, correctly interpreting the role of the Bielschowsky tilt test in superior oblique muscle paralysis is of paramount importance for the effective clinical management and treatment of associated conditions.

Assessing hydrological connectivity for natural-artificial catchment with a new framework integrating graph theory and network analysis

Anthropogenic activities alter the underlying surface conditions and arrangements of landscape features in a drainage basin, interfering with the pollutant (e.g., dissolved nitrogen, phosphorus) transport network configuration and altering the hydrological response. Assessing the impact of anthropogenic activities on hydrological connectivity for natural-artificial catchment is critical to understand the hydrological-driven ecosystem processes, services and biodiversity. However, quantifying this impact at catchment scale remains challenging. In this study, a new framework was proposed to quantify the impact of anthropogenic activities on hydrological connectivity combined with graph theory and network analysis. This framework was exemplified in a natural-artificial catchment of the Yangtze River basin of China. Based on remote sensing and field-investigated data, three transport networks were constructed, including natural transport network (N1), ditch-road transport network (N2), and terrace-dominated transport network (N3), which reflected the different human intervention. The results showed that human intervention improved the connectivity of the nodes and enhanced the complexity of the catchment transport network structure. Anthropogenic activities significantly decreased the hydrological structural connectivity of the catchment. In particular, compared with the N1 network, the critical nodes for hydrological connectivity which were judged by connectivity indexes were reduced by 92.94% and 95.29% in the N2 and N3 network, respectively. Furthermore, the ditch-road construction had a greater impact than terraces in decreasing hydrological structural connectivity at catchment scale. This framework has proven effective in quantifying the hydrological connectivity analysis under different human intervention at the catchment scale and facilitates the improvement of catchment management strategies.

[Characteristics of visual function in children with autism complicated with mental retardation]

Objective: To explore the characteristics of visual function and eye diseases in children with autism spectrum disorder (ASD) and mental retardation. Methods: It was a cross-sectional study. Two hundred and ninety-two cases (584 eyes) of children with ASD combined with mental retardation from 7 special education schools in Chaoyang District of Beijing, including 235 males (80.48%) and 57 females (19.52%); The age ranged from 2 to 18 years old. Subjective far and near vision, near stereoacuity, objective vision, diopter, anterior segment and fundus were examined. In addition, 300 students with normal intelligence level, aged 2 to 18 years, were included as controls. LogMAR was used to record vision examination. Subjective, objective vision and diopter were examined. Mann Whitney U test or Kruskal Wallis H test was used for the data of children with different genders, different age. Results: Among 584 eyes of children with ASD and mental retardation, 272 eyes (47.22%) were ametropia, 260 eyes (45.14%) were astigmatism, 29 eyes (5.03%) were hyperopia, 10 eyes (1.74%) were myopia, and 47 eyes (8.16%) were amblyopia risk factors. Among 292 children, there were 20 cases of strabismus (6.85%), 3 cases of color weakness (1.03%), and 4 cases of external eye abnormalities (1.37%). Two hundred and eleven children completed near stereopsis examination, of which 54 (25.59%) were within 100″ and 157 (74.41%) were within 200″ to 900″. Two hundred and seventy-two eyes with ametropia, 157 eyes (57.72%) needed correction but did not. The median and quartile of subjective and objective logMAR visual acuity were 0.22(0.10, 0.35), 0.10(0.00, 0.22), respectively; There were no significant differences in far visual acuity, near visual acuity, objective visual acuity, diopter, and near stereoacuity between different genders of ASD children with mild or moderate mental retardation (all P>0.05); There was a statistically significant difference in ASD children with mild mental retardation at different age rangs (H=21.453, P<0.001). There was a statistically significant difference in subjective tests such as far visual acuity and near visual acuity, for children with moderate mental retardation (Z=-3.508, -4.503; P<0.001). There was no statistically significant difference in objective visual acuity, diopter and near stereo acuity(all P>0.05). There are 300 healthy children as the control group, with LogMar's subjective far vision is 0.10(0.00, 0.22), and the objective vision is 0.00(0.00, 0.10), diopter 0.25 (-0.25, 0.50) D. Compared with healthy children, ASD children with mental retardation had a significant difference in subjective far vision and objective vision (Z=-8.527, -10.393; P<0.001). There was no significant difference in diopter (Z=-1.274, P=0.203). Conclusions: The subjective and objective visual acuity of children with ASD combined with mental retardation was lower than that of healthy children. The prevalence and uncorrected rate of refractive errors, strabismus, amblyopia and other eye diseases were significantly higher than those of healthy children. Their refractive errors were mainly astigmatism, and the rates of correction and treatment were low.

[Advances in the development of ocular cardiac reflex in extraocular muscle surgery]

Ocular cardiac reflex (OCR) usually occurs in ophthalmic surgery, especially in extraocular muscle(s) surgery. OCR generally can cause sinus bradycardia, arrhythmia, reduced atrial pressure, ventricular tachycardia, ventricular fibrillation, ventricular doublet, dizziness, nausea and other symptoms. Severe cases will appear cardiac arrest, respiratory arrest, etc. Recent studies on the mechanism of OCR and the relationship between surgical operation and anaesthesia in extraocular muscle surgery and the occurrence of OCR are reviewed in this paper in order to reduce the occurrence of OCR and treatment of OCR in extraocular muscle surgery.

[Graded vertical rectus tenotomy for small angle vertical deviation]

Objective: To observe the effectiveness of the graded vertical rectus tenotomy procedure for small-angle vertical deviation. Methods: Retrospective case series study. Twelve patients, including 8 males and 4 females, with an average age of (48±8) years were treated in Tianjin Eye Hospital from January 2017 to December 2019 for diplopia in primary gaze by strabismus surgery. The disease duration was (15±7) months. MRI/CT scan of the orbits and brain was performed to exclude the orbital and craniocerebral diseases. All patients underwent ocular movement examination, with the prism and alternate cover test to detect the deviation angle in primary gaze and the double Maddox test. Based on the results, the posterior segment of the nasal/temporal superior/inferior rectus muscle was operated. The changes of vertical and cyclotorsion deviation angle and the relationship between the vertical rectus graded tenotomy and corrected vertical deviation angle were observed at 1 day after surgery and the last follow-up. The vertical deviation angle was represented by M (Q₁, Q₃). Friedman test (Bonferroni correction) and linear fitting analysis were used for statistical analysis. Results: The follow-up time of all patients was (7±3) months. The vertical deviation angle in primary gaze before surgery [7.00 (5.25, 7.75) PD] was significantly different from that at 1 day after surgery [1.00 (1.00, 2.00) PD] and the last follow-up [1.50 (1.00, 2.00) PD] (P<0.001, P=0.003). There was no significant difference in postoperative cyclotorsion in all patients. Linear fitting results showed that 50% to 90% vertical rectus tenotomy corrected 5 to 8 PD vertical deviation (R²=0.72; P<0.001). Conclusion: The graded vertical rectus tenotomy procedure can effectively improve the small-angle vertical deviation in primary gaze.

[Clinical observation of anterior tucking of the superior oblique tendon for correction of excyclotropia in adults]

Objective: To investigate the clinical effect of anterior 1/3 superior oblique tendon tucking in acquired symptomatic excyclotropia adults. Methods: Retrospective case series. Seven patients (7 eyes) with acquired symptomatic excyclotropia who underwent an anterior 1/3 superior oblique tendon tuck procedure in Tianjin Eye Hospital from January 2019 to December 2019 were included. There were 5 male patients and 2 female patients, with an average age of (49±12) years old. All the patients had a history of a closed head injury. There was torsional diplopia in primary position, and eye movement examination showed paralysis of the superior oblique muscle in the affected eye, without obvious hyperactivity of the inferior oblique muscle. The anterior 1/3 tendon of the superior oblique muscle was tucked during surgery according to the relaxation of the superior oblique tendon in the forced duction test. The paired-sample nonparametric rank sum test was used to analyze the preoperative and postoperative (at 1 day after surgery and the last follow-up) excyclotropia angle. Results: The mean tuck amount was (7.7±1.8) mm (range, 6.0 to 10.0 mm). During operation, patients complained that excyclotropia improved markedly. The excyclotropia angle with the double Maddox rod test improved significantly from preoperative 10° (8°, 15°) to 2° (0°, 3°) at 1 day (Z=-2.379; P<0.05) and 2° (2°, 5°) at the last follow-up (Z=-2.375; P<0.05). The follow-up period was (112+38) days. All patients had no complaints of excyclotropia at the last follow-up. Conclusions: The anterior 1/3 superior oblique tendon tucking can effectively improve clinical symptoms in the primary position in adults with acquired excyclotropia and diplopia. The short-term postoperative results seem to be stable, without significant regression. (Chin J Ophthalmol, 2021, 57: 685-688).

[Clinical analysis and surgical treatment of atypical acute acquired concomitant esotropia]

Objective: To investigate the clinical characteristics, possible etiology and surgical efficacy of acute acquired concomitant esotropia (AACE) with atypical etiology. Methods: Case-control study. Twelve patients, including 7 males and 5 females, who complained of diplopia and were diagnosed with AACE in Tianjin Eye Hospital from January to December 2019 and underwent surgical treatment were included. The duration of the disease was (8.83±3.71) months. All patients underwent routine ocular examination except amblyopia and ocular organic lesions. MRI examination of the orbits and the brain was performed in all the patients in order to screen orbital and craniocerebral diseases, and patients denied that the existence of common causes of AACE (such as occlusion of one eye, mental or psychological factors, medium to high myopia, etc. during medical examination). The characteristics of the disease, the difference of deviation angle at 33 cm and 5 m, and the changes of deviation angle and stereopsis before and after surgery were analyzed. The forced duction test was performed before operation, and the distance between the sclera margin and the midpoint of the medial rectus muscle attachment was measured and compared with the patients with intermittent exotropia (10 cases) and comitant esotropia (10 cases). Paired sample t-test and one-way analysis of variance were used for statistical analysis. Results: The mean spherical equivalent was (1.70±0.88) D in all AACE patients, and the deviation angle was (22.42±5.82) prism diopter (PD) at 33 cm and (20.00±4.86) PD at 5 m in primary gaze, which were not statistically significant (P=0.371). The force duction test showed no obvious tension or contracture of the medial rectus and no paralysis. In patients with AACE, the horizontal distance from the midpoint of the medial rectus to the limbus was (5.20±0.27) mm, versus (5.30±0.25) mm in intermittent exotropia patients and (5.30±0.31) mm in concomitant esotropia patients. All the differences were not statistically significant (P=0.618). All the patients with AACE had residual esotropia (mean, 3.42 to 6.33 PD) at 6 weeks, 3 months, and 6 months postoperatively, and their stereopsis improved more than before, with no stereopsis in 2 patients before surgery and stereopsis in all 12 patients after surgery. Conclusions: AACE patients with atypical etiology do not have high myopia and hyperopia. There is no significant difference between the distance and near angles. The occurrence of esotropia is related to decompensation of esophoria, which may result in clinical symptoms of diplopia. Conventional surgery can reduce esotropia and restore stereoscopic vision, but there is still a small amount of esophoria after surgery. There is no abnormality in the attachment point of the medial rectus muscle. (Chin J Ophthalmol, 2021, 57: 348-352).

[MRI study of rectus extraocular muscles in concomitant exotropia with small angle vertical deviation]

Objective: To observe the changes of four pulley locations of extraocular rectus muscles and rectus muscle volumes, as well as superior and inferior part ratio of horizontal rectus muscles, in concomitant exotropia with small-angle vertical deviation in primary gaze. Methods: Cross-sectional study. Data was collected from January 2018 to December 2019 in Tianjin Eye Hospital. The pulley position changes and volumes of four extraocular rectus muscles in the coronal position of patients who had concomitant exotropia without vertical deviation (group A) or with small-angle vertical deviation in primary gaze (<5 prism diopter; group B) and normal controls (group C) were observed using MRI, and the changes of the volume ratio of the superior and inferior parts of the horizontal rectus muscle were calculated. One way analysis of variance and Kruskal-Wallis test were used for statistical analysis. Results: There were 19 patients (38 eyes; 10 males, 9 females) aged (30±7) years in group A, ten patients (20 eyes; 4 males, 6 females) aged (27±6) years in group B, and 20 healthy volunteers (40 eyes) in group C. Age and gender distribution were matched among the three groups (all P>0.05). Among the three groups, the pulley locations of the four extraocular rectus muscles were not significantly different (all P>0.05). The medial rectus muscle volume in groups A [(358.6±44.9) mm³; t=6.405, P<0.01] and B [(334.7±35.6) mm³; t=6.025, P<0.01] was significantly smaller than group C [(437.5±49.3) mm³]. There was no statistically significant difference in the superior and inferior muscle volume ratio of the lateral rectus in three groups (all P>0.05), while the ratio in group B was more dispersive. Conclusions: The pulley location changes of four extraocular rectus muscles of patients with concomitant exotropia and small-angle vertical deviation in primary gaze are not significant, but the medial rectus volume in patients who had concomitant exotropia with vertical deviation or not is significantly smaller. The dispersive superior and inferior muscle volume ratio of the horizontal rectus muscles may be related to the small angle of vertical deviation in clinical examinations. (Chin J Ophthalmol, 2021, 57: 223-227).

Circ_0001982 accelerates the progression of colorectal cancer via sponging microRNA-144

OBJECTIVE

The aim of this study was to uncover the expression pattern and biological function of circ_0001982 in the progression of colorectal cancer (CRC).

PATIENTS AND METHODS

Relative expression level of circ_0001982 in 66 paired CRC tissues and adjacent normal tissues was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The association between circ_0001982 level and clinical indexes of CRC patients was assessed. The effect of circ_0001982 on cellular behaviors of HT29 and HCT-116 cells was evaluated in vitro. Dual-Luciferase reporter gene assay was conducted to verify the binding relation between circ_0001982 and microRNA-144. Finally, rescue experiments were performed to assess the role of the circ_0001982/microRNA-144 axis in mediating the progression of CRC.

RESULTS

Circ_0001982 was significantly up-regulated in CRC tissues when compared with adjacent normal ones. CRC patients with a high expression level of circ_0001982 showed a significantly higher rate of distant metastasis and worse survival. Knockdown of circ_0001982 remarkably attenuated the proliferative, migratory, and invasive capacities of HCT-116 cells. However, opposite results were observed after the overexpression of circ_0001982 in HT29 cells. MicroRNA-144 was verified as a target gene of circ_0001982, which could be negatively regulated by circ_0001982. Furthermore, microRNA-144 was capable of reversing the regulatory effect of circ_0001982 on the proliferative, migratory, and invasive capacities of CRC cells.

CONCLUSIONS

Up-regulated circ_0001982 was closely related to distant metastasis and poor prognosis of CRC. In addition, circ_0001982 attenuated the progression of CRC by negatively regulating microRNA-144.

The investigation of hepatitis A virus and hepatitis E virus co-infection in humans and animals in China

The aim of this study was to investigate the prevalence of co-infection of hepatitis A and hepatitis E virus (HAV/HEV) in patients with acute hepatitis as well as in different animal species. A total of 46 serum samples from patients diagnosed as hepatitis A or hepatitis E and 675 fecal samples of 11 animal species were collected. The IgM class antibodies to HEV and HAV, respectively, were detected by enzyme-linked immunosorbent assay. HEV and HAV RNAs were extracted from serum and fecal samples for the nested reverse transcription polymerase chain reaction. At least 10.9% (5/46) of the patients were co-infected with both HAV and HEV. Fifteen percent (18/120) of rabbit fecal samples and 17.5% (7/40) of swine fecal samples were positive for HEV RNA, but only 1% (2/200) of ferret fecal samples were positive for HAV RNA. Our study showed that co-infection with both HAV and HEV in patients and animals is infrequent. At least in our study, we showed that ferrets may represent the potential HAV hosts. Keywords: hepatitis A virus; hepatitis E virus; co-infection; zoonosis; prevalence.

Highly sensitive and specific detection of hepatitis B virus DNA and drug resistance mutations utilizing the PCR-based CRISPR-Cas13a system

OBJECTIVES

Undetectable or low-level hepatitis B virus (HBV) DNA and drug resistance mutations in patients may increase the risk of HBV transmission or cause active viral replication and other clinical problems. Here, we established a highly sensitive and practical method for HBV and drug resistance detection using a polymerase chain reaction (PCR) -based CRISPR-Cas13a detection system (referred to as PCR-CRISPR) and evaluated its detection capability using clinical samples.

METHODS

Specific CRISPR RNAs (crRNAs) are designed for HBV DNA detection and YMDD (tyrosine-methionine-aspartate-aspartate) variant identification. The HBV DNA was detected in 312 serum samples for HBV diagnosis using quantification PCR (qPCR) and PCR-CRISPR. Additionally, 424 serum samples for YMDD testing were detected by qPCR, direct sequencing, and our assay.

RESULTS

Using PCR-CRISPR, one copy per test of HBV DNA was detected with HBV-1 crRNA in 15 min after PCR amplification. Consistent results with qPCR were observed for 302 samples, while the remaining 10 samples with low-level HBV DNA were detectable by PCR-CRISPR and droplet digital PCR but not by qPCR. PCR-CRISPR diagnosed all 412 drug-resistant samples detected by the YMDD detection qPCR kit and direct sequencing, as well as the other 12 drug-resistant samples with low-level HBV DNA undetectable by qPCR and direct sequencing.

CONCLUSIONS

We developed a novel PCR-CRISPR method for highly sensitive and specific detection of HBV DNA and drug resistance mutations. One copy per test for HBV DNA and YMDD drug resistance mutations could be detected. This method has wide application prospects for the early detection of HBV infection, drug resistance monitoring and treatment guidance.

[Paying attention to the application of imaging examination in strabismus]

There are many pathogenic factors of strabismus. In addition to the changes of alignment and ocular movement, there may be abnormal pathways and development of extraocular muscles, abnormalities of orbital and intraorbital connective tissue, paralysis of cranial nerves (oculomotor nerve, trochlear nerve, and abductor nerve), and nuclear and supranuclear lesions, accompanied by other cerebral dysplasia sometimes. In recent years, advances in imaging technology and its application in the professional field of strabismus have made it possible to clearly observe the eye, orbital, intracranial, and innervation changes, which is helpful to clarify the etiology of strabismus and extraocular muscle-related diseases, and to provide a basis for the diagnosis and treatment of strabismus. Strabismus specialists should learn and pay attention to the application of imaging examination, so as to achieve in-depth understanding and accurate treatment. (Chin J Ophthalmol, 2020, 56: 166-170).

Experimental study on penetration characteristic of submerged steam jet in quiescent water

The direct contact condensation is an effective way to rapid depressurization for light water reactor, such as pressure suppression pool, for which the characteristic of steam plume is a key parameter to evaluate the efficiency of depressurization. In this paper, a series of visualization experiments are described which investigate the characteristic of steam plume, the influence of jetting direction, air mass fraction, water temperature, diameter of jet on the steam plume were analyzed. The results show that, the dimensionless steam plume length increased with the increase of inlet pressure and water temperature for pure steam submerged jet, a correlation was set up to predict the dimensionless penetration length and the predicted errors were within the band of ±15%. Furthermore, the penetration length decreased with the rise of air mass fraction due to buoyancy force, the penetration length increased with the increase of inlet pressure, and the jet penetration length for vertical jet is longer than horizontal jet about 25% at the same inlet pressure and air mass fraction.

[Smoking abstinence rate and its associated factors between abrupt and gradual smoking cessation]

Objective: To analyze and compare the abstinence rate of smoking quitting methods and its associated factors between abrupt and gradual smoking cessation in smokers with drug-based therapy. Methods: A prospective clinical study was conducted in patients undergoing quitting smoking intervention in Ruijin Hospital smoking cessation clinic between June 2013 and May 2016. All the subjects were randomized in a 1∶1 ratio into the abrupt smoking cessation group (smoking as usual over 3 weeks before a planned quit day, and then stopping smoking abruptly) and the gradual smoking cessation group (gradually reducing tobacco use over 3 weeks before a planned quit day, and then stopping smoking totally). The primary outcome was the complete abstinence rate, and the secondary outcomes included 1-month, 3-month and 6 month 7-day point prevalence of abstinence rates and 3 month sustained abstinence rates. Changes of body weight and drug adverse events were also compared. Results: A total of 314 moderate to severe nicotine-dependent patients were admitted in the study, including 157 patients in the abrupt smoking cessation and 157 patients in the gradual smoking cessation group. Fourteen patients fell off during the follow-up. For the complete abstinence rate, the gradual smoking cessation group was higher than the abrupt smoking cessation group(55.0% vs. 36.9%, χ(2)=9.841, P=0.002) .For 7-d smoking abstinence rate in the 1st, 3rd, 6th month, there was no significant difference between the 2 groups (all P>0.05). As for the 3-month sustained abstinence rate, a higher smoking quitting rate was seen in the gradual smoking cessation group compared to the abrupt smoking cessation group in the 6-month follow-up (17.9% vs.8.7%, χ(2)=5.441, P=0.020). The adverse drug reaction incidence was higher in the abrupt smoking cessation group than the gradual smoking cessation group (Gastrointestinal discomfort: 39.2% vs. 17.7%, χ(2)=12.336, P=0.000; Dreaminess: 40.2% vs. 13.3%, χ(2)=20.172, P=0.000). Conclusions: For moderate to severe nicotine-dependent patients, the gradual smoking cessation could serve to enhance the abstinence rate and mitigate the withdrawal symptoms.

[A study of superior oblique muscle changes in superior oblique palsy using magnetic resonance imaging]

Objective: To observe the magnetic resonance imaging(MRI) changes of superior oblique muscle and to study the relationship between changes and clinical signs in superior oblique muscle palsy. Methods: Cross-sectional study. Data was collected from January 2014 to January 2016 in Tianjin Eye Hospital. Twenty-three(30 eyes) patients who were diagnosed with superior oblique palsy included 15 patients with congenital superior oblique palsy [9 males and 6 females aged (32±13) years (range, 12-53 years)] and 8 cases with acquired superior oblique palsy [3 males and 5 females aged (36±15) years(range, 17-62 years)]. Twenty normal volunteers [11 males and 9 females aged (35±13) years (range, 15-60 years)] were also observed. Coronal MRI was used to detect superior oblique muscle morphological changes, as well as the maximum cross-sectional area and volume changes. The relationship between the morphological changes and vertical deviation and cyclotorsion in the primary gaze was analyzed. Rank sum test, t-test and Person correlation analysis were used for statistical analysis. Results: Two morphological changes were obtained using MRI in superior oblique muscle palsy, including round (19 eyes) and oval changes (11 eyes). The maximum cross-sectional area in eyes with the palsied superior oblique muscle [round, (10.38±1.76) mm(2); oval, (11.16±2.02) mm(2)] was significantly smaller than fellow eyes [(14.16±1.88) mm(2); Z=6.208, 5.178, both P<0.001] and eyes with normal superior oblique muscle [(15.40±1.71) mm(2); Z=8.215, 6.330, both P<0.001], and the volume changes [round, (104.92±13.36) mm(3); oval, (110.43±16.11) mm(3)] were also significantly different from fellow eyes [(254.57±20.15) mm(3); Z=7.511, 5.396, both P<0.001] and eyes with normal superior oblique muscle [(258.04±16.36) mm(3); Z=10.040, 6.936, both P<0.001]. There was no significant difference in vertical deviation between round and oval superior oblique muscle palsies (P>0.05). The cyclotorsion effect of the round change in superior oblique muscle palsy was significantly less than that of the oval change (5.47°±1.05° vs. 7.36°±0.97°, t=3.083, P=0.005). The correlation of the volume changes with vertical deviation angle in the primary gaze was not significantly different (round and oval, both P<0.05), but there was a correlation between the morphological changes and cyclotorsion strabismus (r=0.631, P=0.004; r=0.801, P=0.003). Conclusions: In the patients with superior oblique palsy, MRI scans shows that the maximum cross-sectional area decreased and the volume was smaller, which indicated superior oblique muscle atrophy. Deformation of superior oblique muscle do not significantly affect the vertical deviation, but is in correlation with cyclodeviation. (Chin J Ophthalmol, 2019, 55:20-24).

[Advances in research of synergistic divergence]

Synergistic divergence is a rare condition characterized by complete absence of adduction that is associated with simultaneous abduction of the affected eye on attempted adduction. This causes the affected eye to move further into abduction on gaze to the normal side and results in extreme divergence of both eyes. It is sometimes referred to as exotropic Duane syndrome with synergistic divergence (type 4 Duane syndrome) or congenital fibrosis syndrome with synergistic divergence. Diseases combined with synergistic divergence fall within the category of congenital cranial dysinnervation disorders (CCDDs). The ocular associations reported with synergistic divergence are uncommon and include Horner syndrome, ocular albinism, foveal hypoplasia, Goldenhar syndrome and pupillary abnormalities. MRI and electro-oculographic study suggested that this is the result of CCDDs. Various surgical techniques have been tried in individual cases including large recession of the lateral rectus muscle, lateral rectus muscle extirpation, large resection of the medial rectus (MR) muscle, weakening procedures of the oblique muscles, combination of lateral rectus orbital wall fixation with MR resection, but further investigations with large-scale samples are needed. Recent research advances in the definition, etiology, and treatment of synergistic divergence are reviewed in this article. (Chin J Ophthalmol, 2019, 55:63-67).

[The preliminary study of stimulus input temporal changes on the visual cortex of rats at different ages]

Objective: To observe the impact of the input temporal changes on visual cortex of rats cells and the change of the synaptic efficacy, for the study of visual developmental plasticity mechanism. Methods: Experimental research. The brain slice of ten 14d healthy Wistar rats and ten 21d healthy Wistar rats were recorded with whole cell recording technique, using single stimulation and combined stimulate model, to observe the visual cortex of rats neurons changes in synaptic activity. Change the stimulus input sequence, and observe the visual cortex of rats changes of synaptic efficacy. Using the paired t test to compare the change of excitatory postsynaptic potential (EPSC) of visual cortex. Result: The difference between single stimulation and combined stimulate about EPSC was statistically significant, which was decreased (14.3±7.4) % (n=15) in single stimulation and (53.4±17.5) % (n=20) in combined stimulation for P14 rats which were long-term depression (t_s2=3.9, t_s1+s2=2.2; P<0.05) , and was increased (27.5±11.4) % (n=16) in single stimulation and (34.6±10.3) % (n=10) in combined stimulation for P20 rats which were long-term potentiation (t_s2=2.3, t_s1+s2=3.5; P<0.05) . Rats in different development period have a specific time window for input temporal changes. Combined stimulation patterns produced by the neuron cell reaction were not just an accumulation of simple response caused by single stimulation. For P14 rats, its time window was of about ±0.5ms. However, for P20 rats, scope of time window reduced to ±0.1ms. Conclusions: Different development period of rats, change the stimulation pattern can cause the change of the visual cortex synapses reaction, and stimulate the temporal change within a specific time window to producenonlinear results. (Chin J Ophthalmol, 2016, 52: 936-940).

PHACTR4 regulates proliferation, migration and invasion of human hepatocellular carcinoma by inhibiting IL-6/Stat3 pathway

OBJECTIVE

Phosphatase and actin regulator 4 (PHACTR4) is one member of the largely uncharacterized PHACTR family of protein phosphatase 1 (PP1)-and actin-binding proteins. PHACTR4 is significantly deleted or mutant in many tumor subtypes, such as breast, colorectal, lung, neural, ovarian, and renal cancers. However, the role of PHACTR4 in human hepatocellular carcinoma (HCC) is completely unknown.

MATERIALS AND METHODS

Ten paired HCC tissues and adjacent non-cancerous tissues were used to detect the expression PHACTR4. Real-time PCR was used to detect the mRNA level of PHACTR4 in clinic samples. The protein level of PHACTR4 was determined by Western blot. Retrovirus-based gene transduction was used to generate Flag-tagged PHACTR4 HepG2 stable cell line. BrdU assay was used to determine the cell growth of HepG2 cells. The cell cycle distribution was detected by flow cytometry assay. In vitro scratch wounding and Matrigel invasion assays were used to test the migration and invasion ability of HepG2 cells.

RESULTS

The expression of PHACTR4 was noticeably decreased in clinical HCC tissues, compared to the non-tumoral tissues. Overexpression of PHACTR4 inhibited HCC cells proliferation, colony formation, migration and invasion, and resulted in significant cycle arrest. PHACTR4 attenuated both constitutive and IL-6-induced phosphorylation of signal transducer and activator of transcription 3 (Stat3), and inhibited Stat3 downstream genes expression.

CONCLUSIONS

Overall, our results suggest that PHACTR4 is a tumor suppressor in HCC by inhibiting IL-6/ Stat3 pathway.

Stabilization of boron carbide via silicon doping

Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in the material, and this raises the possibility of doping the boron carbide to eliminate this polytype. In this work, we have synthesized boron carbide doped with silicon. We have conducted a series of characterizations (transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and x-ray diffraction) on pure and silicon-doped boron carbide following static compression to 50 GPa non-hydrostatic pressure. We find that the level of amorphization under static non-hydrostatic pressure is drastically reduced by the silicon doping.

Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis

AIM

The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty.

METHODS

A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection.

RESULTS

Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis.

CONCLUSION

In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

Hypothyroidism and first-trimester spontaneous miscarriages

OBJECTIVE

To evaluate the association between hypothyroidism and first-trimester spontaneous miscarriages and to explain the mechanism.

MATERIALS AND METHODS

Patients admitted between October and May 2011 with threatened miscarriage in the first trimester were analyzed and levels of progesterone and thyroid hormones as T3, T4, and thyroid-stimulating hormone (TSH) were estimated. Once hypothyroidism was diagnosed, patients were treated with sodium levothyroxine (LT4) as substitution and outcomes were observed.

RESULTS

Measurement of progesterone was useful for predicting the outcome of threatened miscarriage The results showed that progesterone (P) = 14.74 ng/ml is selected as predictive value to judge whether the fetal treatment was successfully or not. When serum P value is above 14.74 ng/ml before treatment, it may favour a miscarriage, if the serum P value is below 14.74 ng/ml, miscarriage is unlikely; its sensitivity and specificity are high. The risk for miscarriage in patients diagnosed with hypothyroidism in which LT4 substitution was similar to the level observed in the controls, and P between the two groups had no distinct difference. The mechanism explaining the risk of miscarriage increased by thyroid disorders remains unclear, which needs advanced research.

CONCLUSION

Screening of thyroid disorders has important clinical significance in early pregnancy, and substitution of LT4 to those who are in the early pregnancy with hypothyroidism could reduce the risk of miscarriage.

P1-02-04: Estrogen Receptor beta Inhibits Breast Cancer EMT by Regulating the Expression of miR-200

Estrogen receptor beta (ERβ) mediates the effects of estrogens in a variety of human tissues and regulates cellular processes involved in initiation and progression of breast cancer such as cell proliferation and migration. Clinical studies produced contradictory data regarding the role for ERβ in prognosis of metastatic breast cancer and the molecular mechanism through which ERβ influences cell migration and invasion has not been fully elucidated. Here we show that induction of ERβ expression inhibits epithelial to mesenchymal transition (EMT) in metastatic breast cancer cells. This correlates with an ERβ-mediated induction in the expression of the epithelial marker E-cadherin and downregulation of its transcriptional repressors ZEB1 and SIP1. ERβ alters the expression of ZEB1 and SIP1 by inducing the expression of the miR-200a, miR200b and miR-429. Downregulation of these miRNAs in ERβ-expressing cells resulted in decreased cell-cell contact and decline of E-cadherin levels. In addition, ERβ was found to inhibit the invasiveness of metastatic breast cancer cells in a zebrafish xenotransplantation model. We are now examining breast cancer specimens derived from ductal carcinomas and metaplastic breast cancers to see whether ERβ levels decline in the mesenchymal regions and ERβ expression is correlated with epithelial markers. These data propose a crucial role for ERβ in the regulation of EMT and in prognosis of invasive and metastatic breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-02-04.

57 NUCLEAR TRANSFER WITH RABBIT EMBRYONIC STEM CELLS: SERUM-STARVATION IMPROVES THE QUALITY OF CLONED EMBRYOS

Rabbit cloning by NT with somatic cells is so far a rather inefficient process. However, this technology is urgently required to generate rabbits with a humanized immune system as a source of human polyclonal antibodies. Embryonic stem cells (ESCs) have a number of advantages over somatic cells as tools for cell-mediated transgenesis including long periods of proliferation in vitro, higher frequency of homologous recombination between exogenous and chromosomal DNA, and less requirements for reprogramming (Rideout et al. 2000 Nat. Genet. 24, 109–110). To improve rabbit cloning we have derived and characterized 19 putative rabbit ESC lines and tested cells from 6 lines as donors for NT. First, we assessed in vitro development of NT embryos. Blastocyst rates varied in the range of 6–68% depending on the particular cell line and passage number, but the quality of the resultant embryos was worse compared to NT embryos derived from adult fibroblasts [hatched blastocysts: 13/214 (6%) v. 36/86 (42%), respectively]. Transfer of NT embryos derived from the ESC line showing the highest development to blastocysts into recipients resulted only in implantations (70%, 7/10) but not in offspring. Assuming that poor quality of NT embryos derived from ESCs could be due to the incompatibility between cell cycles of donor and recipient cells we used serum starvation to make ESCs more suitable for nuclear transfer. Serum starvation of one of the ESC lines (0.5% FCS for 3 days) greatly improved the quality of cloned embryos compared to those derived from non-starved cells of the same ESC line as indicated by the high proportions of hatched [38/151 (25%) v. 4/153 (3%)] and attached [25/151 (17%) v. 0%] to the surface of a culture dish blastocysts. Moreover, some of these blastocysts grew in vitro for 14–25 days. Our study provides evidence that the quality of NT embryos derived from ESCs can be significantly improved using serum starvation of donor cells suggesting possible effect of this treatment on the cell cycle synchronization. We are currently testing whether serum starvation of ESCs would also improve post-implantation development of rabbit NT embryos. This work is supported by Roche Diagnostic GmbH.

Design of annular photonic crystal slabs

We present the design of realistic annular photonic-crystal (APC) structures of finite thickness aiming to obtain a complete photonic bandgap (PBG). The APC is composed of dielectric rods and circular air holes in a triangular lattice such that each rod is centered within each hole. The optical and geometrical values of the structure are studied, and the interplay between various design parameters is highlighted. The coupled role of the inner-dielectric-rod radius, material types, and slab thickness is investigated. It is shown that the slab thickness is vital to obtain a complete photonic bandgap below the light line, and the specific value of the inner-dielectric-rod radius to sustain the maximum PBG if the hole radius is fixed at proper value is found.

102 RABBIT CLONING: HISTONE ACETYLATION STATUS OF DONOR CELLS AND CLONED EMBRYOS

Epigenetic status of the genome of a donor nucleus is likely to be associated with the developmental potential of cloned embryos produced by somatic cell nuclear transfer (SCNT). Prevention of epigenetic errors by manipulation of the epigenetic status of donor cells is expected to result in improvement of cloning efficiency. In this study, we transferred cultured rabbit cumulus cells (RCC) and fetal fibroblasts (RFF) from genetically marked rabbits (Ali/Bas) into metaphase II (MII) oocytes and analyzed the levels of histone H3K9 acetylation in donor cells and cloned embryos. We also assessed the correlation between the histone acetylation status of donor cells and cloned embryos and their developmental potential. To test whether alteration of the histone acetylation status affects development of cloned embryos, we treated donor cells with sodium butyrate (NaBu), a histone deacetylase inhibitor. Further, we tried to improve cloning efficiency by chimeric complementation of cloned embryos with one or two blastomeres from in vitro-fertilized or parthenogenetic embryos. Histone acetylation in donor cells and cloned embryos was detected by anti-acH3K9 antibody using Western immunoblot analysis or immunochemistry, respectively. Data were analyzed by chi-square (developmental rates) or Student-Newman-Keuls (histone acetylation) test. The levels of acetylated histone H3K9 were higher in RCCs than in RFFs (P &lt; 0.05). Although the type of donor cells did not affect development to blastocyst, after transfer into recipients, RCC-cloned embryos induced a higher initial pregnancy rate as compared to RFF-cloned embryos (40% vs. 20%; P &lt; 0.05). However, almost all pregnancies with either type of cloned embryos were lost by the middle of gestation and only one fully developed; a live RCC-derived rabbit was obtained. Treatment of RFFs with NaBu significantly (P &lt; 0.05) increased the level of histone H3K9/14 acetylation and the proportion of nuclear transfer embryos developing to blastocyst (49% vs. 33% with non-treated RFF; P &lt; 0.05). The distribution of signals for acH3K9 in either group of cloned embryos did not resemble that in in vivo-fertilized embryos, suggesting that reprogramming of this epigenetic mark is aberrant in cloned rabbit embryos and cannot be corrected by treatment of donor cells with NaBu. Aggregation of embryos cloned from NaBu-treated RFFs with blastomeres from in vivo-derived embryos improved development to blastocyst, but no cloned offspring were obtained. Two live cloned rabbits were produced from this donor cell type only after aggregation of cloned embryos with a parthenogenetic blastomere. Our study demonstrates that the levels of histone acetylation in donor cells and cloned embryos correlate with their developmental potential and can be a useful epigenetic mark to predict efficiency of SCNT rabbits. This work was supported by the Bayerische Forschungsstiftung and by Therapeutic Human Polyclonals, Inc.

38 RABBIT NUCLEAR TRANSFER AND IN VIVO-FERTILIZED EMBRYOS FAIL TO EXPRESS A MOUSE Oct-4 PROMOTER-DRIVEN EGFP REPORTER GENE

Reprogramming of a donor cell genome during somatic cell nuclear transfer (SCNT) is largely dependent on appropriate expression of 'pluripotency'? genes, such as Oct-4 (POU5F1). Recently, we transfected bovine fetal fibroblasts with GOF18-ΔPE-EGFP, a reporter gene construct for the Oct-4 promoter and assessed the expression of Oct-4 after SCNT (Wuensch et al. 2006 Reprod. Fertil. Dev. 18, 144). Our previous study on DNA methylation reprogramming revealed that rabbit in vivo-fertilized and cloned embryos differ from bovine embryos in respect to this epigenetic modification (Shi et al. 2004 Biol. Reprod. 71, 340–347), suggesting differences in the mechanism of epigenetic reprogramming between these two species. In this study, we tested whether GOF18-ΔPE-EGFP could be used to monitor Oct-4 expression in rabbit cloned embryos. The reporter gene construct included the EGFP gene flanked by a 9-kb fragment of the murine Oct-4 upstream region with a deletion in the proximal enhancer (PE) and a 9-kb fragment containing the nontranscribed murine structural Oct-4 gene. The 21.2-kb fragment GOF18-DPE-EGFP was released from the vector backbone by NotI digestion and purified with QIAquickGel Extraction Kit (Qiagen, Hilden, Germany) after gel electrophoresis. Four stable transfected colonies of rabbit fetal fibroblasts (RFF), none of which exhibited green fluorescence, were used for SCNT. The resulting embryos were examined on Days 2–5 by fluorescence microscopy. To detect endogenous Oct-4 expression, in vivo-fertilized embryos were stained with anti-mouse Oct-3 antibody and then incubated with secondary Alexa 488-conjugated goat anti-mouse antibody. The most prominent endogenous Oct-4 expression was detected in in vivo-fertilized embryos at the morula and blastocyst stages. Depending on the donor cell line used for nuclear transfer, cleavage and blastocyst rates ranged from 56 to 97% and from 33 to 49%, respectively. When a total of 230 cloned embryos at the 2-to 16-cell stages and 93 cloned morulae and blastocycts were examined by fluorescence microscopy, none of the examined embryos exhibited fluorescence signals indicating the lack of Oct-4 promoter activity. Taking into account the fact that both cloned and in vivo-fertilized rabbit embryos have specific patterns of DNA methylation reprogramming, which are different from that of bovine embryos, we injected GOF18-ΔPE-EGFP gene constructs into pronuclei of in vivo-fertilized zygotes. None of the 74 injected embryos, which were examined at the 2-cell to blastocyst stages, showed fluorescence signals. Our results demonstrate that rabbit nuclear transfer and in vivo-fertilized embryos are unable to activate a mouse Oct-4 promoter-reporter construct. Potential reasons include incompatibilities between mouse Oct-4 promoter sequences and rabbit transcription factors as well as specific mechanisms of epigenetic reprogramming in the rabbit. This work was supported by the Bayerische Forschungsstiftung.

[Clinical study on retarding aging effect of tongbu recipe to traditional Chinese medicine]

OBJECTIVE

To study the mechanism of Tongbu No. 1 (TB1, a prescription for reinforcing Kidney and Spleen, clearing up the bowel viscera to send Turbid downward and regulating Qi and blood) in retarding aging.

METHODS

A controlled, multiple indexes study was conducted in 56 old subjects randomized into 3 groups.

RESULTS

TB1 (containing ginseng leaf, cistanche, fleeceflower root, immature bitter orange, rhubarb, etc) could improve various symptoms of aging, and had the effect in regulating immune and endocrinal function, scavenging free radicals and adjusting coli flora. The effects of TB1 and TB2 (containing ginseng leaf, cistanche and fleeceflower root) were different significantly (P < 0.05, P < 0.01).

CONCLUSION

TB1 has a good comprehensive effect in retarding aging.

Metallothionein, neurotrophins and selegiline in providing neuroprotection in Parkinson's disease

The finding that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) elicits parkinsonism in human beings suggests that endogenous or xenobiotic neurotoxic compounds may be involved in the etiology of Parkinson's disease (PD). We have shown that cerebrospinal fluid (CSF) of newly diagnosed and drug untreated patients with PD contains a low molecular weight substance(s) which inhibits the growth and function of dopaminergic neurons in culture. In addition, selegiline in a dosage below the level that inhibits monoamine oxidase B (MAO-B), protects dopaminergic neurons in culture against toxic factor(s) present in the CSF of patients with PD, and the said effect is mediated via elaboration of brain-derived neurotrophic factor (BDNF). In view of the fact that 6-hydroxydopamine (6-OHDA) or MPTP causes parkinsonism by generating free radicals, and inducers of metallothionein (MT) isoforms avert the said neurotoxicity, we intended to learn whether MT isoforms were capable of scavenging free radicals. By employing electron spin resonance spectroscopy (ESR), we examined for the first time the free radical scavenging effects of MT-I and MT-II isoforms on four types of free radicals. Solutions of 0.15 mM of MT-I and 0.3 mM of MT-II scavenged the 1,1-diphenyl-2-picrylhydrazyl radicals completely. Furthermore, they were able to scavenge hydroxyl radicals generated in a Fenton reaction. Moreover, MT-I scavenged almost 90% of the superoxide generated by the hypoxanthine and xanthine oxidase system, while MT-II could only scavenge 40%. By using 2,2,6,6-tetramethyl-4-piperidone as a "spin-trap" for the reactive oxygen species (containing singlet oxygen, superoxide and hydroxyl radicals) generated by photosensitized oxidation of riboflavin, and measuring the relative signal intensities of the resulting stable nitroxide adduct, 2,2,6,6-tetramethyl-4-piperidone-1-oxyl, we observed that MT-II could scavenge 92%, while MT-I could completely scavenge all the reactive species generated. The results of this investigation are interpreted to suggest that selegiline by preventing the generation of free radicals, MT isoforms by scavenging free radicals, and neurotrophins by rescuing dopaminergic neurons are capable of attenuating oxidative stress and of providing neuro-protection in PD.

Modulation of nigrostriatal dopaminergic transmission by antisense oligodeoxynucleotide against brain-derived neurotrophic factor

Brain-derived neurotrophic factor (BDNF) promotes the differentiation and growth of developing dopamine (DA) neurons and supports the survival of mature DA cells in culture. However, the neurotrophic role of endogenous BDNF in the adult DA system in vivo has not been well established. To investigate the hypothesis that blockade of endogenous BDNF expression results in DA dysregulation, we used an 18-mer antisense oligodeoxynucleotide (ODN) targeted to the first ATG codon of the BDNF transcript. The biological activity of the antisense ODN was initially tested in vitro. In cultured dopaminergic MES 23.5 cells, antisense BDNF (20 microM) effectively reduced BDNF protein expression and cell survival. Furthermore, in primary embryonic mesencephalic cultures, antisense BDNF reduced the number of tyrosine hydroxylase positive neurons and inhibited [3H]DA uptake in a time- and dose-dependent manner. The specificity of the antisense molecule was confirmed by comparing its effects with those of a control ODN having the same base composition but in scrambled sequence. In rats, two days following an intranigral or intrastriatal injection of antisense BDNF (0.5 microg), we observed a two-fold and five-fold increase in nigral DA levels, respectively, but no change in striatal DA content. Seven days after an intrastriatal antisense BDNF injection, DA levels were elevated in the striatum apparently due to decreased DA turnover. These observations suggest that inhibition of endogenous BDNF expression tends to augment rather than inhibit nigrostriatal DA transmission. Thus, the biological effects of endogenous BDNF on the nigrostriatal DA system in the adult organism merits further investigation.

Stable interaction between G-actin and neurofilament light subunit in dopaminergic neurons

Excessive accumulation of neurofilaments in the cell bodies and proximal axons of motor neurons is a major pathological hallmark of motor neuron diseases. In this communication we provide evidence that the neurofilament light subunit (68 kDa) and G-actin are capable of forming a stable interaction. Cytochalasin B, a cytoskeleton disrupting agent that interrupts actin-based microfilaments, caused aggregation of neurofilaments in cultured mesencephalic dopaminergic neurons, suggesting a possible interaction between neurofilaments and actin; which was tested further by using crosslinking reaction and affinity chromatography techniques. In the cross-linking experiment, G-actin interacted with individual neurofilament subunits and covalently cross-linked with disuccinimidyl suberate, a homobifunctional cross-linking reagent. Furthermore, G-actin was extensively cross-linked to the light neurofilament subunit with this reagent. The other two neurofilament subunits showed no cross-linking to G-actin. Moreover, neurofilament subunits were retained on a G-actin coupled affinity column and were eluted from this column by increasing salt concentration. All three neurofilament subunits became bound to the G-actin affinity column. However, a portion of the 160 and 200 kDa neurofilament subunits did not bind to the column, and the remainder of these two subunits eluted prior to the 68 kDa subunit, suggesting that the light subunit exhibited the highest affinity for G-actin. Moreover, neurofilaments demonstrated little or no binding to F-actin coupled affinity columns. The phosphorylation of neurofilament proteins with protein kinase C reduced its cross-linking to G-actin. The results of these studies are interpreted to suggest that the interaction between neurofilaments and actin, regulated by neurofilament phosphorylation, may play a role in maintaining the structure and hence the function of dopaminergic neurons in culture.

Selegiline protects dopaminergic neurons in culture from toxic factor(s) present in the cerebrospinal fluid of patients with Parkinson's disease

The cerebrospinal fluid (CSF) of patients with Parkinson's disease (PD) contains substance(s) that inhibit the growth and functions of dopaminergic neurons. Further, selegiline, a monoamine oxidase B (MAO) inhibitor (0.125-0.250 microM) enhanced the number of tyrosine hydroxylase (TH)-positive neurons, augmented the high affinity uptake of dopamine (DA), and averted the neurotoxic effects of CSF of PD patients on rat mesencephalic neurons in culture. The neuroprotective effects of selegiline may be related either to its ability to inhibit MAO B, preventing the generation of free radicals, or to neuronal rescue property due to unknown mechanisms.

Expression and regulation of brain metallothionein

Many, but not all, zinc-containing neurons in the brain are a subclass of the glutamatergic neurons, and they are found predominantly in the telencephalon. These neurons store zinc in their presynaptic terminals and release it by a calcium-dependent mechanism. These "vesicular" pools of zinc are viewed as endogenous modulators of ligand- and voltage-gated ion channels. Metallothioneins (MTs) are low molecular weight zinc-binding proteins consisting of 25-30% cysteine, with no aromatic amino acids or disulfide bonds. The areas of the brain containing high contents of zinc such as the retina, the pineal gland, and the hippocampus synthesize unique isoforms of MT on a continuous basis. The four MT isoforms are thought to provide the neurons and glial elements with mechanisms to distribute, donate, and sequester zinc at presynaptic terminals; or buffer the excess zinc at synaptic junctions. In this cause, glutathione disulfide may participate in releasing zinc from MT. A similar nucleotide and amino acid sequence has made it difficult to obtain cDNA probes and antibodies capable of distinguishing indisputably among MT isoforms. MT-I and MT-II isoforms are found in the brain and in the peripheral tissues; MT-III isoform, possessing an additional seven amino acids, is expressed mostly in the brain and to a very minute extent in the intestine and pancreas; whereas MT-IV isoform is found in tissues containing stratified squamous epithelial cells. Since MTs are expressed in neurons that sequester zinc in their synaptic vesicles, the regulation of the expression of MT isoforms is extremely important in terms of maintaining the steady-state level of zinc and controlling redox potentials. The concentration of zinc has been shown to be altered in an extensive number of disorders of the central nervous system, including alcoholism. Alzheimer-type dementia, amyotrophic lateral sclerosis, Down's syndrome, epilepsy, Friedreich's ataxia, Guillaine-Barré syndrome, hepatic encephalopathy, multiple sclerosis, Parkinson's disease, Pick's disease, retinitis pigmentosa, retinal dystrophy, schizophrenia, and Wernicke-Korsakoff syndrome. The status of MT isoforms and other low molecular weight zinc-binding proteins in these conditions, diseases, disorders, or syndromes is being delineated at this time. Since several of these disorders, such as amyotrophic lateral sclerosis, are associated with oxidative stress, and since MT is able to prevent the formation of free radicals, it is believed that cytokine-induced induction of MT provides a long-lasting protection to avert oxidative damage.

Cerebrospinal fluid of Parkinson's disease patients inhibits the growth and function of dopaminergic neurons in culture

We report the possible existence of an inhibitory factor in the CSF of Parkinson's disease patients that inhibits the function and growth of dopaminergic neurons in rat mesencephalic culture. After 40 hours' exposure to the < 10 kd fraction of CSF from PD patients, the high-affinity dopamine uptake was 66% of that of cultures exposed to CSF from controls. However, the number of dopaminergic neurons remained unchanged at this time. After 90 hours' exposure to the < 10 kd fraction of CSF from PD patients, the number of dopaminergic neurons decreased to 10% of that in cultures exposed to CSF from controls, and the size of the remaining dopaminergic neurons in the culture became smaller. This inhibitory factor did not affect the growth of other types of neurons. The chemical nature of this inhibitory factor is under investigation.

Distribution of zinc metallothionein I mRNA in rat brain using in situ hybridization

Metallothionein (MT) isoforms I and II were first identified and characterized in our laboratories in several regions of brain, in hippocampal neurons in primary culture, and in retinoblastoma and neuroblastoma cell lines. In this study, by having employed the MT-I cDNA as a probe, we sought to gain additional insight about the function of MT by discerning the regional distribution of its mRNA. Northern blot analyses of brain mRNA revealed that the administration of zinc enhanced dramatically MT-I mRNA (570 bp). The in situ hybridization study revealed that MT-I mRNA was located in several areas of brain, with the highest concentrations found in the cerebellum, hippocampus, and ventricles. The results of these studies are interpreted to suggest that zinc enhances the synthesis of MT mRNA and MT in turn may participate in zinc associated functions in neurons.

Cloning of the gene for glutamate decarboxylase and its expression during conidiation in Neurospora crassa

Neurospora crassa glutamate decarboxylase (GAD) is produced during conidiation and stored in dormant conidia. Polyclonal antibody was generated to GAD that had been purified to homogeneity. The anti-GAD antibody was specific for N. crassa GAD and inhibited GAD activity. The level of GAD protein decreased during conidial germination, indicating that GAD was degraded during this phase of development. The anti-GAD antibody was used to isolate a cDNA clone of GAD from a lambda ZAP cDNA expression library. Escherichia coli containing a plasmid with the cDNA insert produced GAD activity. The cDNA clone contained a 2.6 kbp insert and hybridized to a 2.6 kb mRNA species from conidiating cultures of N. crassa. GAD mRNA was not present in vegetative hyphae. In conidiating cultures, GAD mRNA was first detected when conidia began to appear. The level of GAD mRNA increased as conidiation progressed. This is the first example of the cloning of an enzyme that is regulated at the level of mRNA during the asexual developmental cycle of N. crassa.

Purification and characterization of metallothionein and its activation of pyridoxal phosphokinase in trout (Salmo gairdneri) brain

1. Brain metallothionein was isolated and purified for the first time from rainbow trout. 2. Brain metallothionein exhibited an elution volume (Ve/Vo) of 2.0, had a molecular weight of 6762 Daltons, and contained a zinc content of 9 micrograms/mg protein. 3. Brain pyridoxal phosphokinase was isolated and assayed for the first time in rainbow trout. 4. Zinc (0.20 microM) or zinc metallothionein (6-30 microM) stimulated the activity of brain pyridoxal kinase in a linear fashion. 5. The results of these studies are interpreted to suggest that in trout brain zinc metallothionein may participate in metabolism of vitamin B6 and formation of pyridoxal phosphate, the active coenzyme.