EXPRESS: Phospholipase C gamma mediates endogenous brain-derived neurotrophic factor - regulated calcitonin gene-related peptide expression in colitis - induced visceral pain.

BACKGROUND: Visceral hypersensitivity is a complex pathophysiological paradigm with unclear mechanisms. Primary afferent neuronal plasticity marked by alterations in neuroactive compounds such as calcitonin gene-related peptide is suggested to underlie the heightened sensory responses. Signal transduction that leads to calcitonin gene-related peptide expression thereby sensory neuroplasticity during colitis remains to be elucidated. RESULTS: In a rat model with colitis induced by 2,4,6-trinitrobenzene sulfonic acid, we found that endogenously elevated brain-derived neurotrophic factor elicited an up-regulation of calcitonin gene-related peptide in the lumbar L1 dorsal root ganglia. At seven days of colitis, neutralization of brain-derived neurotrophic factor with a specific brain-derived neurotrophic factor antibody reversed calcitonin gene-related peptide up-regulation in the dorsal root ganglia. Colitis-induced calcitonin gene-related peptide transcription was also inhibited by brain-derived neurotrophic factor antibody treatment. Signal transduction studies with dorsal root ganglia explants showed that brain-derived neurotrophic factor-induced calcitonin generelated peptide expression was mediated by the phospholipase C gamma, but not the phosphatidylinositol 3-kinase/Akt or the mitogen-activated protein kinase/extracellular signal-regulated protein kinase pathway. Application of PLC inhibitor U73122 in vivo confirmed that colitis-induced and brain-derived neurotrophic factor-mediated calcitonin gene-related peptide up-regulation in the dorsal root ganglia was regulated by the phospholipase C gamma pathway. In contrast, suppression of the phosphatidylinositol 3-kinase activity in vivo had no effect on colitis-induced calcitonin gene-related peptide expression. During colitis, calcitonin gene-related peptide also co-expressed with phospholipase C gamma but not with p-Akt. Calcitonin gene-related peptide up-regulation during colitis correlated to the activation of cAMP-responsive element binding protein in the same neurons. Consistently, colitis-induced cAMP-responsive element binding protein activation in the dorsal root ganglia was attenuated by brain-derived neurotrophic factor antibody treatment. CONCLUSION: These results suggest that colitis-induced and brain-derived neurotrophic factor-mediated calcitonin generelated peptide expression in sensory activation is regulated by a unique pathway involving brain-derived neurotrophic factorphospholipase C gamma-cAMP-responsive element binding protein axis.

Endogenous BDNF augments NMDA receptor phosphorylation in the spinal cord via PLCγ, PKC, and PI3K/Akt pathways during colitis.

BACKGROUND: Spinal central sensitization is an important process in the generation and maintenance of visceral hypersensitivity. The release of brain-derived neurotrophic factor (BDNF) from the primary afferent neurons to the spinal cord contributes to spinal neuronal plasticity and increases neuronal activity and synaptic efficacy. The N-Methyl-D-aspartic acid (NMDA) receptor possesses ion channel properties, and its activity is modulated by phosphorylation of its subunits including the NMDA receptor 1 (NR1). METHODS: Colonic inflammation was induced by a single dose of intracolonic instillation of tri-nitrobenzene sulfonic acid (TNBS). NR1 phosphorylation by BDNF in vivo and in culture was examined by western blot and immunohistochemistry. Signal transduction was studied by direct examination and use of specific inhibitors. RESULTS: During colitis, the level of NR1 phospho-Ser(896) was increased in the dorsal horn region of the L1 and S1 spinal cord; this increase was attenuated by injection of BDNF neutralizing antibody to colitic animals (36 µg/kg, intravenous (i.v.)) and was also reduced in BDNF(+/-) rat treated with TNBS. Signal transduction examination showed that the extracellular signal-regulated kinase (ERK) activation was not involved in BDNF-induced NR1 phosphorylation. In contrast, the phosphatidylinositol 3-kinase (PI3K)/Akt pathway mediated BDNF-induced NR1 phosphorylation in vivo and in culture; this is an additional pathway to the phospholipase C-gamma (PLCγ) and the protein kinase C (PKC) that was widely considered to phosphorylate NR1 at Ser(896). In spinal cord culture, the inhibitors to PLC (U73122), PKC (bisindolylmaleimide I), and PI3K (LY294002), but not MEK (PD98059) blocked BDNF-induced NR1 phosphorylation. In animals with colitis, treatment with LY294002 (50 µg/kg, i.v.) blocked the Akt activity as well as NR1 phosphorylation at Ser(896) in the spinal cord. CONCLUSION: BDNF participates in colitis-induced spinal central sensitization by up-regulating NR1 phosphorylation at Ser(896). The PI3K/Akt pathway, in addition to PLCγ and PKC, mediates BDNF action in the spinal cord during colitis.

Inhibition of NMDAR reduces bladder hypertrophy and improves bladder function in cyclophosphamide induced cystitis.

PURPOSE: We examined the role of NMDAR in the regulation of bladder hypertrophy and function in a rat model of cyclophosphamide induced cystitis. MATERIALS AND METHODS: Cystitis was induced by intraperitoneal injection of cyclophosphamide (150 mg/kg body weight). NMDAR phosphorylation (activity) and signal transduction pathways were examined by direct measurement and by specific inhibitors in vivo. Bladder hypertrophy was measured by bladder weight/body weight and type I collagen expression. Bladder function was examined by metabolic recording, conscious cystometry and detrusor muscle strip contractility in response to carbachol. RESULTS: NMDAR activity measured by the phosphorylation level of the NMDAR1 (NR1) subunit was expressed in the spinal cord but not in the bladder at 48 hours of cystitis. NMDAR inhibition with dizocilpine (MK-801) reduced the cystitis induced increment of bladder weight and type I collagen up-regulation in the bladder. NMDAR regulated type I collagen up-regulation was mediated by the PI3K/Akt pathway. NMDAR inhibition also attenuated cystitis induced urinary frequency measured by metabolic cage and cystometry. Cystitis decreased the responsiveness of detrusor muscle strips to carbachol, which was reversed by MK-801 in vivo. Unlike MK-801 the NMDAR antagonist D-AP5, which could not block central NMDAR activity, had no effect on bladder hypertrophy, type I collagen up-regulation or Akt activation caused by cystitis in the bladder. CONCLUSIONS: Findings suggest that NMDAR activity has a role in cystitis induced bladder hypertrophy and overactivity. NMDAR mediated Akt activation may underlie the mechanism of bladder dysfunction.

Posterior scleral reinforcement surgery effectively slows the rate of high myopic progression in children.

PURPOSE: To investigate the rate of axial length elongation and high myopia progression in operated eyes before and after posterior scleral reinforcement (PSR) surgery. METHODS: This was a retrospective study. Children with pathological myopia treated with PSR at Beijing Tongren Hospital between May 2013 and May 2020 were recruited into the PSR surgery group. Children matched for age and myopia were recruited into the control group. All children underwent comprehensive ophthalmologic examinations. The presurgical and postsurgical rates of axial length elongation and myopic (spherical equivalent) progression were calculated. RESULTS: A total of 35 PSR patients were included in the study. The mean age was 6.5±3.0 years (range 2 to 14 years). Mean follow-up was 544 days (range 216 to 1657 days). The rate of axial length elongation was significantly less after posterior scleral reinforcement surgery (0.505±0.048mm per year prior to surgery; 0.382±0.045mm per year after surgery, P<0.001). The rate of myopic progression decreased after posterior scleral reinforcement surgery (1.162±0.118 D per year prior to surgery; 0.153±0.437 D per year after surgery, P=0.0239). There was no statistically significant difference in axial length elongation or myopic progression between pre-inclusion and post-inclusion in the control group. Moreover, the children's best-corrected visual acuity was significantly improved after posterior scleral reinforcement surgery (P<0.001). CONCLUSION: Posterior scleral reinforcement surgery effectively decreased the rate of high myopic progression and axial length elongation in children.

Nearwork-induced transient myopia and parental refractive error.

PURPOSE: To investigate the relationship between parental refractive error and the nearwork-induced transient myopia (NITM) characteristics of their children. METHODS: Three hundred sixty children (173 boys and 187 girls) aged 6 to 17 years were tested. Initial NITM and its decay time (DT) were assessed objectively (WAM-5500, Grand-Seiko) immediately after binocularly viewing and performing a sustained near task (5 diopters [D]) for 5 minutes, incorporating a cognitive demand with full distance refractive correction in place. The NITM was classified into three categories: low (< 0.15 D), moderate (0.15 to 0.30 D), or high (≥0.30 D), whereas its decay was classified into two categories, namely, complete or incomplete. In addition, the children were divided into three groups based on the number of myopic parents (none, one, or two) and into four groups based on the level of parental myopia (no, low, moderate, or high). RESULTS: Neither paternal nor maternal refractive error was associated with either their children's initial NITM magnitude or its DT in the myopic, emmetropic, or hyperopic groups or the combined group. No significant differences (p > 0.05) in the NITM magnitude, DT, or decay time constant were found as related to the number of myopic parents or level of parental myopia. Multiple odds ratio for incomplete decay of NITM did not change significantly (p > 0.05) with either an increase in number of myopic parents or level of parental myopia. CONCLUSIONS: There was no association between parental refractive error and their children's NITM characteristics. This suggests a primary environmental basis for the NITM characteristics in the children.

Activation of extracellular signal-regulated protein kinase 5 is essential for cystitis- and nerve growth factor-induced calcitonin gene-related peptide expression in sensory neurons.

BACKGROUND: Cystitis causes considerable neuronal plasticity in the primary afferent pathways. The molecular mechanism and signal transduction underlying cross talk between the inflamed urinary bladder and sensory sensitization has not been investigated. RESULTS: In a rat cystitis model induced by cyclophosphamide (CYP) for 48 h, the mRNA and protein levels of the excitatory neurotransmitter calcitonin gene-related peptide (CGRP) are increased in the L6 dorsal root ganglia (DRG) in response to bladder inflammation. Cystitis-induced CGRP expression in L6 DRG is triggered by endogenous nerve growth factor (NGF) because neutralization of NGF with a specific NGF antibody reverses CGRP up-regulation during cystitis. CGRP expression in the L6 DRG neurons is also enhanced by retrograde NGF signaling when NGF is applied to the nerve terminals of the ganglion-nerve two-compartmented preparation. Characterization of the signaling pathways in cystitis- or NGF-induced CGRP expression reveals that the activation (phosphorylation) of extracellular signal-regulated protein kinase (ERK)5 but not Akt is involved. In L6 DRG during cystitis, CGRP is co-localized with phospho-ERK5 but not phospho-Akt. NGF-evoked CGRP up-regulation is also blocked by inhibition of the MEK/ERK pathway with specific MEK inhibitors U0126 and PD98059, but not by inhibition of the PI3K/Akt pathway with inhibitor LY294002. Further examination shows that cystitis-induced cAMP-responsive element binding protein (CREB) activity is expressed in CGRP bladder afferent neurons and is co-localized with phospho-ERK5 but not phospho-Akt. Blockade of NGF action in vivo reduces the number of DRG neurons co-expressing CGRP and phospho-CREB, and reverses cystitis-induced increases in micturition frequency. CONCLUSIONS: A specific pathway involving NGF-ERK5-CREB axis plays an essential role in cystitis-induced sensory activation.

Up-regulation of brain-derived neurotrophic factor in primary afferent pathway regulates colon-to-bladder cross-sensitization in rat.

BACKGROUND: In humans, inflammation of either the urinary bladder or the distal colon often results in sensory cross-sensitization between these organs. Limited information is known about the mechanisms underlying this clinical syndrome. Studies with animal models have demonstrated that activation of primary afferent pathways may have a role in mediating viscero-visceral cross-organ sensitization. METHODS: Colonic inflammation was induced by a single dose of tri-nitrobenzene sulfonic acid (TNBS) instilled intracolonically. The histology of the colon and the urinary bladder was examined by hematoxylin and eosin (H&E) stain. The protein expression of transient receptor potential (TRP) ion channel of the vanilloid type 1 (TRPV1) and brain-derived neurotrophic factor (BDNF) were examined by immunohistochemistry and/or western blot. The inter-micturition intervals and the quantity of urine voided were obtained from analysis of cystometrograms. RESULTS: At 3 days post TNBS treatment, the protein level of TRPV1 was increased by 2-fold (p < 0.05) in the inflamed distal colon when examined with western blot. TRPV1 was mainly expressed in the axonal terminals in submucosal area of the distal colon, and was co-localized with the neural marker PGP9.5. In sensory neurons in the dorsal root ganglia (DRG), BDNF expression was augmented by colonic inflammation examined in the L1 DRG, and was expressed in TRPV1 positive neurons. The elevated level of BDNF in L1 DRG by colonic inflammation was blunted by prolonged pre-treatment of the animals with the neurotoxin resiniferatoxin (RTX). Colonic inflammation did not alter either the morphology of the urinary bladder or the expression level of TRPV1 in this viscus. However, colonic inflammation decreased the inter-micturition intervals and decreased the quantities of urine voided. The increased bladder activity by colonic inflammation was attenuated by prolonged intraluminal treatment with RTX or treatment with intrathecal BDNF neutralizing antibody. CONCLUSION: Acute colonic inflammation increases bladder activity without affecting bladder morphology. Primary afferent-mediated BDNF up-regulation in the sensory neurons regulates, at least in part, the bladder activity during colonic inflammation.

Reproducibility of nearwork-induced transient myopia measurements using the WAM-5500 autorefractor in its dynamic mode.

PURPOSE: To evaluate the reproducibility of nearwork-induced transient myopia (NITM) measurements obtained objectively using an open-field autorefractor (WAM-5500) in its dynamic mode. METHODS: NITM was assessed in 22, visually-normal, teen-aged and young-adult subjects using an infrared autorefractor (WAM-5500) in the dynamic mode. Measurements were obtained from the right eye in two test sessions separated by either 30 minutes or 2 days. Initial NITM and its decay were assessed monocularly by the same experimenter immediately after binocularly viewing and performing a detailed near task (5D) for 5 minutes incorporating a cognitive demand, with habitual distance refractive correction in place. Data were averaged over 10-second bins for 3 minutes (180 seconds; 18 bins) for the decay analysis. The NITM post- minus pre-task difference and its limits of agreement (LOA), as well as intraclass correlation coefficient (ICC), were calculated to evaluate reproducibility over the two test sessions for the initial NITM magnitude and its decay. RESULTS: The group mean (±SE) initial NITM and its decay duration were 0.33 ± 0.09 D and 0.28 ± 0.08 D, and 118.6 ± 14.3 seconds and 132.3 ± 12.2 seconds respectively, for each test session, which were not significantly different (p > 0.05). The difference (range), LOA, and ICC (95% confidence interval [CI]) were 0.06D (-0.15, 0.64), -0.29 to 0.40D, and 0.90D (0.77, 0.96) for the initial NITM; they were -13.6 (-150.0, 140.0) seconds, -174.5 to 147.3 seconds, and 0.14 (0.00, 0.52) for decay duration, respectively, for each test session. The ICC range for the first 50 secs of the NITM response/decay was 0.90 to 0.96. CONCLUSIONS: The initial NITM was highly repeatable. The initial decay phase was moderately repeatable, with the later decay phase being more variable, yet still yielding acceptable reproducibility in many cases. Both of these key parameters, namely initial NITM and its early decay, can be assessed reliably and with good reproducibility. This is important in future longitudinal studies of NITM, and its possible relation to refractive development.

Baseline characteristics of nearwork-induced transient myopia.

PURPOSE: The purpose of the present study was to describe the baseline refractive and nearwork-induced transient myopia (NITM) characteristics of the Beijing Myopia Progression Study, a 3-year cohort study, that has three overall specific aims: to investigate the natural history of NITM in schoolchildren living in the inner city of Beijing aged between 7 and 17 years; to investigate the possible relation between NITM and permanent myopia; and to determine the possible associations with NITM (eg, parental history). METHODS: Three hundred eighty-six students (187 males and 199 females) were enrolled. The mean ages were 8.4 ± 1.1 years and 14.2 ± 1.6 years for the primary school and secondary school students, respectively. Baseline refractive aspects were determined clinically. Initial NITM and its decay were assessed objectively immediately after binocularly viewing and performing a sustained near task (5 minutes; 5 diopters [D]), incorporating a cognitive demand with full distance refractive correction in place. RESULTS: Initial NITM (mean ± SD) / decay time (median, first quartile, and third quartile) was 0.18 ± 0.16 D / 50 (20, 90) seconds, 0.09 ± 0.13 D / 30 (10, 40) seconds, and 0.10 ± 0.19 D / 20 (10, 40) seconds among the myopic, emmetropic, and hyperopic students, respectively, for the combined school levels. Initial NITM and decay time were significantly larger/longer in the myopic versus the other two refractive groups. CONCLUSIONS: The present findings demonstrate that in a large sample of school-aged children with myopia, the initial NITM magnitude was significantly larger and the decay duration was significantly longer than that observed in age-matched children with either emmetropia or hyperopia. Follow-up for the next 3 years will provide insight into the possible role of NITM in the development of permanent myopia.

[Comparison between binocular, open-field auto ref/keratometer and conventional autorefractor].

OBJECTIVE: To compare the refractive results between open-field auto ref/keratometer and conventional autorefractor, and to investigate the effect of cycloplegic to this difference. METHODS: Three hundred and four primary and secondary school students were consecutively enrolled in Beijing Tongren Hospital. Non-cycloplegic and cycloplegic objective refractions were performed for each subject by conventional autorefractor (Accuref-K9001, Shin Nippon, Japan) and binocular, open-field auto ref/keratometer (Grand Seiko Co., Ltd., Hiroshima, Japan). The coincidence rate of sphere, spherical equivalent (SE) and axis (defined as difference of diopter ≤ 0.50 D, difference of axis degree ≤ 20°) were calculated; Bland-Altman and distribution analysis were performed according to mean and difference of SE. RESULTS: The coincidence rate of sphere, SE and axis were 77.3%, 78.6% and 66.0% before cycloplegic and increased to 94.4%, 95.1% and 69.5% after cycloplegic, respectively. The difference (95%CI) of SE before cycloplegic between these two refractometers was 0.12 (-1.04 to 1.29) D and was positively correlated with the mean of SE (after cycloplegic) (r(pearson) = 0.21, P < 0.001). The difference (95%CI) of SE after cycloplegic was -0.08 (-0.60 to 0.45) D. The difference (95%CI) of SE of K9001 autorefractor before and after cycloplegic was larger than that of WAM autorefractor [0.51 (-0.83 - 1.84) D and 0.31 (-0.66 to 1.28) D, P < 0.001]. Before cycloplegic, SE measured by WAM autorefractor showed myopic more than 0.25 D than K9001 (group 1) was found in 51 (16.8%) subjects; difference within 0.25 D was found in 160 (52.6%) subjects; hyperopic more than 0.25 D (group 3) was found in 93 (30.6%) subjects. After cycloplegic, 69 (22.7%) subjects were found in group 1, and subjects increased to 213 (70.1%) and decreased to 22 (7.2%) in group 2 and group 3, respectively. CONCLUSION: The binocular, open-field auto ref/keratometer provides more hyperopic readings than conventional autorefractor. It will be useful in both clinical screening and scientific research because it produces less instrument myopia than that of conventional autorefractor.

[Advances in near work-induced transient myopia].

The possible mechanism of myopia remains controversial while gene and environment are two generally acknowledged factors underlie the development of human myopia. Near work which is a primary, environmentally based factor in the development and progression of permanent myopia (PM) may take effect via near work-induced transient myopia (NITM). In this review, the definition, measuring procedure and relative evaluation parameters of NITM as well as its characteristics, methods for reducing NITM and its possible mechanisms reported in the literature will be summarized.

Refractive Lens Exchange Surgery in Early-Onset High Myopia Patients With Partial Cataract.

Purpose: By reporting clinical characteristics and retinal image quality before and after refractive lens replacement surgery in early-onset high myopia (eoHM) patients presenting with partial cataract, we emphasized the need for an objective way to grade the severity of partial cataracts. Methods: This retrospective, consecutive case series included six Chinese patients (nine eyes). Analysis of previous medical records, visual acuity, optometry, retinal image quality, and axial length (AXL) before surgery and after surgery was performed. Results: Five females and one male (nine eyes) with a mean (± SD) age of 11.6 ± 7.9 years (range: 4-25 years) were included in this study. The preoperative spherical power ranged from -7.5 to -42 D. The mean follow-up time was 36 months (range: 24-48 months). Phacoemulsification was followed by in-the-bag implantation of intraocular lens. For patients who were under 6 years old, posterior capsulotomy + anterior vitrectomy were performed simultaneously. All surgeries were uneventful and no postoperative complications occurred during the entire follow-up period. All patients' uncorrected visual acuity improved by ≥2 lines postoperatively(Snellen acuity). LogMAR best-corrected visual acuity was improved at 24-month (P = 0.042) and endpoint (P = 0.046) follow-ups. Modulation transfer function cutoff frequency (MTFcutoff) and objective scatter index (OSI) was significantly improved at 12-month (P = 0.025, P = 0.038), 24-month (P = 0.005, P = 0.007) and endpoint (P = 0.005, P = 0.008) follow-ups. Postoperative AXL remained stable during 2-4 year follow-ups (P > 0.05). Conclusion: Refractive lens replacement surgery is safe and effective for improving functional vision in eoHM patients presenting with partial cataract. Retinal image quality could provide a useful and objective way to facilitate partial cataract severity evaluation and surgery decision making.

Endogenous nerve growth factor regulates collagen expression and bladder hypertrophy through Akt and MAPK pathways during cystitis.

Type I collagen forms the main constituent of the extracellular matrix in visceral organs. We reported here that cyclophosphamide (CYP)-induced cystitis significantly increased the production of type I collagen in the inflamed bladder leading to increases in the bladder weight and the thickness of the bladder wall. The endogenous nerve growth factor (NGF) in the urinary bladder regulated type I collagen expression because the neutralizing NGF antibody attenuated cystitis-induced type I collagen up-regulation in the inflamed bladder. Neutralizing NGF antibody also subsequently reversed cystitis-induced increases in bladder weight. Further studies on the intermediate signaling pathways mediating NGF-induced type I collagen expression in the inflamed bladder during cystitis revealed that Akt, JNK, and ERK1/2 activities were increased in the inflamed bladder, whereas p38 MAPK remained unchanged. Suppression of endogenous NGF level with neutralizing NGF antibody significantly blocked the increased activity of Akt, JNK, and ERK1/2 in the inflamed bladder during cystitis. These results indicate that endogenous NGF plays an important role in the activation of Akt and MAPK in the urinary bladder and in bladder hypertrophy during cystitis.

Analysis of related factors of optical quality in healthy Chinese adults: a community-based population study.

BACKGROUND: In recent years, visual quality has been extensively investigated in various conditions. In this community-based population study, we analyzed the effects of aging, refraction, and Lens Opacification Classification System III (LOCSIII) score on retinal imaging quality in healthy Chinese adults. METHODS: This cross-sectional study was conducted on sub-group subjects from The Handan Eye Study between October 2012 and January 2013. Healthy subjects over 30-years-old with logarithm of the minimal angle of resolution (logMAR) best-corrected visual acuity (BCVA) less than 0 were included. Retinal image quality was measured by optical quality analysis system (OQAS) and recorded as modulation transfer function cutoff frequency (MTFcutoff), OQAS value (OV) 100%, OV20%, OV9%, Strehl ratio (SR), and objective scatter index (OSI). The correlation between age, spherical equivalent refraction (SE), LOCSIII score, and optical quality parameters were investigated by multivariate analysis. RESULTS: Among 1108 verified subjects, 690 subjects (1380 eyes) met the inclusion criteria. Their age ranged from 30 to 76 years, SE ranged from -4.75 to 2.75 D. They were divided into five age groups (30-39, 40-49, 50-59, 60-69, and ≥70 years) for further analysis. After multivariate analysis by mixed-effect linear model, SR (t =  -3.03, P = 0.002), OV20% (t = -2.39, P = 0.017), and OV9% (t = -3.16, P = 0.001) significantly decreased with the increasing age, whereas logMAR BCVA (t = 4.42, P < 0.001) and OSI (t = 4.46, P < 0.001) significantly increased with age. As SE increased, SR (t = 2.74, P = 0.01), OV20% (t = 2.31, P = 0.02), and OV9% (t = 2.79, P = 0.005) significantly elevated, and OSI (t = -3.38, P < 0.001) significantly decreased. With the increase in cortical opacity score, all optical quality parameters except for SR significantly decreased, including MTFcutoff (t = -2.78, P = 0.01), OV100% (t = -2.78, P = 0.005), OV20% (t = -2.60, P = 0.009), and OV9% (t = -2.05, P = 0.040). As posterior sub capsular opacity score increased, MTFcutoff (t = -2.40, P = 0.02) and OV100% (t = -2.40, P = 0.01) significantly decreased, while OSI (t = 7.56, P < 0.001) significantly increased. CONCLUSIONS: In healthy Chinese adult population, optical quality-related parameters significantly decrease with the increasing age, and OSI significantly increases with age. In normal BCVA subjects, optical quality is significantly impacted by cortical and posterior sub capsular opacity rather than by nuclear opacity.

Modulation of motor and sensory pathways of the peristaltic reflex by cannabinoids.

Cannabinoids have long been known to be potent inhibitors of intestinal and colonic propulsion. This effect has generally been attributed to their ability to prejunctionally inhibit release of acetylcholine from excitatory motor neurons that mediate, in part, the ascending contraction phase of the peristaltic reflex. In the present study we examined the effect of cannabinoids on the other transmitters known to participate in the peristaltic reflex using a three-compartment preparation of rat colon that allows separation of ascending contraction, descending relaxation, and the sensory components of the reflex. On addition to the orad motor compartment, anandamide decreased and AM-251, a CB-1 antagonist, increased ascending contraction and the concomitant substance P (SP) release. Similarly, on addition to the caudad motor compartment, anandamide decreased and AM-251 increased descending relaxation and the concomitant vasoactive intestinal peptide (VIP) release. On addition to the central sensory compartment, anandamide decreased and AM-251 increased both ascending contraction and SP release orad, and descending relaxation and VIP release caudad. This suggested a role for CB-1 receptors in modulation of sensory transmission that was confirmed by the demonstration that central addition of anandamide decreased and AM-251 increased release of the sensory transmitter, calcitonin gene-related peptide (CGRP). We conclude that the potent antipropulsive effect of cannabinoids is the result of inhibition of both excitatory cholinergic/tachykininergic and inhibitory VIPergic motor neurons that mediate ascending contraction and descending relaxation, respectively, as well as inhibition of the intrinsic sensory CGRP-containing neurons that initiate the peristaltic reflex underlying propulsive motility.

[Clinical observation on glaucoma filtering blebs in vivo].

Filtering surgery is an effective and a most commonly used technique in managing glaucoma. However, the failure of surgery is often caused by the scar formation of the filtering pathway. It is important for clinicians to evaluate the morphology and the function of the filtering bleb, especially in the early period of post-operation when IOP is normal. The success of surgery relies upon the early intervention whenever the filtering bleb showing the tendency of scarring. This paper reviews recent development in the observation and the treatment of glaucoma filtering blebs.

Urinary bladder organ hypertrophy is partially regulated by Akt1-mediated protein synthesis pathway.

AIMS: The present study aims to investigate the role of Akt in the regulation of urinary bladder organ hypertrophy caused by partial bladder outlet obstruction (pBOO). MAIN METHODS: Male rats were surgically induced for pBOO. Real-time PCR and western blot were used to examine the levels of mRNA and protein. A phosphoinositide 3-kinase (PI3K) inhibitor LY294002 was used to inhibit the activity of endogenous Akt. KEY FINDINGS: The urinary bladder developed hypertrophy at 2 weeks of pBOO. The protein but not mRNA levels of type I collagen and α-smooth muscle actin (αSMA) were increased in pBOO bladder when compared to sham control. The phosphorylation (activation) levels of Akt1 (p-Ser473), mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K), and 4E-BP1 were also increased in pBOO bladder. LY294002 treatment reduced the phosphorylation levels of Akt1 and 4E-BP1, and the protein levels of type I collagen and αSMA in pBOO bladder. The mRNA and protein levels of proliferating cell nuclear antigen (PCNA) were increased in pBOO bladder, and PCNA up-regulation occurred in urothelial not muscular layer. LY294002 treatment had no effect on the mRNA and protein levels of PCNA in pBOO bladder. LY294002 treatment partially reduced the bladder weight caused by pBOO. SIGNIFICANCE: pBOO-induced urinary bladder hypertrophy is attributable to fibrosis, smooth muscle cellular hypertrophy, and urothelium cell hyper-proliferation. Akt1-mediated protein synthesis in pBOO bladder contributes to type I collagen and αSMA but not PCNA up-regulation. Target of Akt1 is necessary but not sufficient in treatment of urinary bladder hypertrophy following pBOO.

N49 phospholipase A2, a unique subgroup of snake venom group II phospholipase A2.

A novel phospholipase A2 (PLA2) with Asn at its site 49 was purified from the snake venom of Protobothrops mucrosquamatus by using SP-Sephadex C25, Superdex 75, Heparin-Sepharose (FF) and HPLC reverse-phage C18 chromatography and designated as TM-N49. It showed a molecular mass of 13.875 kDa on MALDI-TOF. TM-N49 does not possess enzymatic, hemolytic and hemorrhagic activities. It fails to induce platelet aggregation by itself, and does not inhibit the platelet aggregation induced by ADP. However, it exhibits potent myotoxic activity causing inflammatory cell infiltration, severe myoedema, myonecrosis and myolysis in the gastrocnemius muscles of BALB/c mice. Phylogenetic analysis found that that TM-N49 combined with two phospholipase A2s from Trimeresurus stejnegeri, TsR6 and CTs-R6 cluster into one group. Structural and functional analysis indicated that these phospholipase A2s are distinct from the other subgroups (D49 PLA2, S49 PLA2 and K49 PLA2) and represent a unique subgroup of snake venom group II PLA2, named N49 PLA2 subgroup.

Purification, characterization and potent lung lesion activity of an L-amino acid oxidase from Agkistrodon blomhoffii ussurensis snake venom.

L-amino acid oxidases (LAOs) are one of the major components of snake venoms, which possess numerous biological functions. However, little is known of the influence of LAOs on organ lesions. In the present study, a unique LAO from Agkistrodon blomhoffii ussurensis snake venom named ABU-LAO was purified by Heparin-Sepharose FF chromatography followed by an ion-exchange chromatography procedure. The purified ABU-LAO appears a dimer with a molecular mass of approximately 108.8kDa. Kinetics studies showed that ABU-LAO is very active towards its substrates L-Asn, L-Phe, L-Tyr, L-Leu, L-Ile and L-Trp. The most striking observation in the present study is that ABU-LAO causes severe pneumorrhagia, pulmonary interstitial edema, fusion of pulmonary alveoli, cardiac interstitial edema and bleeding when being intravenously injected into BALB/c mice. ABU-LAO also induces liver cell necrosis and release of cytokines including IL-6, IL-12 and IL-2 from highly purified human peripheral blood monocytes and T cells, respectively. In conclusion, ABU-LAO potently induces lesions in lungs and livers. The ability of ABU-LAO will contribute to the understanding of the pathogenesis of snakebite wound.

Regulation of transient receptor potential cation channel subfamily V1 protein synthesis by the phosphoinositide 3-kinase/Akt pathway in colonic hypersensitivity.

The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor or vanilloid receptor 1 (VR1), is expressed in nociceptive neurons in the dorsal root ganglia (DRG) and participates in the transmission of pain. The present study investigated the underlying molecular mechanisms by which TRPV1 was regulated by nerve growth factor (NGF) signaling pathways in colonic hypersensitivity in response to colitis. We found that during colitis TRPV1 protein levels were significantly increased in specifically labeled colonic afferent neurons in both L1 and S1 DRGs. TRPV1 protein up-regulation in DRG was also enhanced by NGF treatment. We then found that TRPV1 protein up-regulation in DRG was regulated by activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway both in vivo and in vitro. Suppression of endogenous PI3K/Akt activity during colitis or NGF treatment with a specific PI3K inhibitor LY294002 reduced TRPV1 protein production in DRG neurons, and also reduced colitis-evoked TRPV1-mediated visceral hypersensitivity tested by hyper-responsiveness to colorectal distention (CRD) and von Frey filament stimulation of abdomen. Further studies showed that TRPV1 mRNA levels in the DRG were not regulated by either colitis or NGF. We then found that an up-regulation of the protein synthesis pathway was involved by which both colitis and NGF caused a PI3K-dependent increase in the phosphorylation level of eukaryotic translation initiation factor 4E-binding protein (4E-BP)1. These results suggest a novel mechanism in colonic hypersensitivity which involves PI3K/Akt-mediated TRPV1 protein, not mRNA, up-regulation in primary afferent neurons, likely through activation of the protein synthesis pathways.