[Analysis of disease composition and primary surgical procedures in pediatric secondary glaucoma inpatients: a single-center study].

Objective: To analyze the disease composition and primary surgical procedures in pediatric inpatients with secondary glaucoma. Methods: A retrospective case series study was conducted. Clinical data of children aged≤16 years with secondary glaucoma who were admitted to the Zhongshan Ophthalmic Center, Sun Yat-sen University, between January 1, 2017, and December 31, 2021, were included. The patients were classified according to the Childhood Glaucoma Research Network (CGRN) classification system, and their diagnoses, underlying factors, gender, age of onset, affected eye(s), age and type of initial surgery, and ophthalmic examination data were analyzed. Statistical analysis was performed using Kruskal-Wallis rank sum test and χ2 test. Results: A total of 540 patients (744 eyes) were included in this study, comprising 319 males (59.1%) and 221 females (40.9%). Unilateral disease was observed in 336 cases (62.2%), while bilateral involvement was present in 204 cases (37.8%). The age of onset was 4.0 (0.0, 9.0) years, and the median age of the first anti-glaucoma surgery was 5.0 (0.7, 10.0) years. Among them, there were 195 cases (36.1%) of secondary glaucoma associated with non-acquired ocular anomalies (SCG-O), with a median age of onset of 0.0 (0.0, 4.0) years, and 97 of these cases (49.7%) were male. secondary glaucoma associated with non-acquired systemic disease or syndrome (SCG-S) were observed in 68 cases (12.6%), with a median age of glaucoma onset of 0.1 (0.0, 4.0) years, and 47 of these cases (69.1%) were male. Secondary glaucoma associated with acquired conditions (SCG-A) accounted for 192 cases (35.6%), with a median age of onset of 9.0 (5.0, 13.0) years, and 125 of these cases (65.1%) were male. There were 85 cases (15.7%) of secondary glaucoma following cataract surgery (SCG-C), with a median age of onset of 3.0 (0.8, 7.0) years, and 50 of these cases (58.8%) were male. Male patients were predominant in SCG-S and SCG-A, with 47 cases (69.1%) and 125 cases (65.1%), respectively (χ2=9.94, 17.52; P=0.002,<0.001). Except for SCG-O, all other types of pediatric secondary glaucoma predominantly affected only one eye: SCG-S in 52 cases (76.5%), SCG-A in 128 cases (66.7%), and SCG-C in 54 cases (63.5%) (χ2=19.06, 21.33, 6.22; all P<0.05). The highest proportion of SCG-O was attributed to congenital ectropion uveae (46 cases, 23.6%). Sturge-Weber syndrome was the most common SCG-S (45 cases, 66.3%), while SCG-A mostly resulted from trauma (59 cases, 30.8%) and corticosteroid use (56 cases, 29.2%). Trabeculectomy (211 eyes, 30.8%) and glaucoma drainage device implantation (197 eyes, 28.7%) were the most frequently performed primary surgical procedures. Conclusions: SCG-O and SCG-A were found to be common types of pediatric secondary glaucoma. The age of onset and the choice of primary anti-glaucoma surgical procedures varied among different types of pediatric secondary glaucoma. However, overall, trabeculectomy and glaucoma drainage device implantation were the primary surgical procedures predominantly employed.

[The experiment study of endovascular denervation in treatment of cancer pain].

Objective: To assess the feasibility and safety of endovascular denervation (EDN) with a multi-electrode radiofrequency ablation catheter on beagles. Methods: A total of 18 beagles, (10.2±1.1) kg,of either gender,were provided by the Animal Center of Southeast University (SYXK (Su) 2016-0013). They were divided equally into three groups:the instant euthanizing group, the long-term follow-up group and the sham operation group. Beagles in the instant euthanizing group were euthanized immediately after EDN. Beagles in the long-term follow-up group were euthanized three months after EDN. Beagles in the sham operation group underwent sham operation and were euthanized three months later. Blood biochemistry was measured at baseline, and immediately, 15 days, 30 days and 90 days after the surgery. Computerized tomographic (CT) angiography was determined before the surgery and 60 days after the surgery. Digital subtraction angiography (DSA) was determined 90 days after the surgery. Histopathologic analyses were used to identify the changes of arterial wall and neuron cells. Results: Beagles in the long-term follow-up group and the sham operation group all underwent EDN successfully without accidental death. No abdominal aortic perforation and peripheral tissue necrosis were found at Necropsy. No vascular injuries were found by CTA and DSA in each group. There was no statistical difference in hematological analyses, 90 days after the surgery:white blood cell:(12.5±1.5)×10(9)/L vs (13.2±0.7)×10(9)/L, P=0.275; red blood cell:(7.0±0.6)×10(9)/L vs (6.3±0.4)×10(9)/L, P=0.089; total bilirubin:(2.9±0.4) µmol/L vs (3.0±0.6) µmol/L, P=0.681; glutamic-pyruvic transaminase:(40±11) U/L vs (37±6) U/L, P=0.168; glutamic oxalocetie transaminase:(51±11) U/L vs (48±9) U/L, P=0.221; urea nitrogen:(7.2±1.2) mmol/L vs (6.9±0.8) mmol/L, P=0.505; creatinine:(60±9) µmol/L vs (59±9) µmol/L, P=0.81; prothrombin time:(7.2±0.7) s vs (7.0±0.7) s, P=0.719. Histopathological analyses showed that there were hypercellular appearance of nerve bundle and thickened perineurium in EDN groups, while normal perineurium around nerve bundle in the sham operation group. Conclusion: EDN could be applied in beagles safely and feasibly.

[Study on correlation between serum 25-hydroxyvitamin D3 level and esophageal variceal bleeding in cirrhotic patients].

Objective: To explore the correlation between serum 25-hydroxyvitamin D3 (25[OH]D(3)) levels and esophageal variceal bleeding (EVB) in cirrhotic patients. Methods: Eighty-three cases with liver cirrhosis hospitalized from November 2016 to January 2017 were collected. The patients were divided into bleeding group (51 cases) and non-bleeding group (32 cases) depending on the presence or absence of bleeding under gastroscopy. Serological tests were performed on both groups, including hemoglobin (Hb), albumin (ALB), alkaline phosphatase (ALP),γ-glutamyltransferase (GGT), interleukin-6 (IL-6), and 25-hydroxyvitamin D3 (25[OH]D(3)). Both groups were analyzed by univariate analysis. The differences between both groups were compared by t-test, after normality test. The other variables were compared by Mann-Whitney U test. The correlation between the relevant variables and EVB were analyzed by Spearman's rank correlation and a multivariate analysis. Cases with primary biliary cirrhosis were relatively low in number (four cases in bleeding group, accounting for 8%, 10 cases in non-bleeding group, accounting for 31%). The effects of ALP and GGT on serum 25(OH)D(3) level were analyzed by stratified analysis. Moreover, ALP and GGT levels were divided into two and three groups: < 140 U/L and >140 U/L and < 30 U/L, > 30 U/L, and ~≤60 U/L. Results: Bleeding group had low levels of hemoglobin (t= -2.827,P= 0.005), alkaline phosphatase (t= -3.097,P= 0.002), gamma-glutamyltransferase (t= -2.292,P= 0.022), and 25(OH)D(3) (t= -3.134,P= 0.002) than non-bleeding group. Both groups (P> 0.05) had similar levels of albumin, interleukin-6, AAR, and FIB-4. Logistic regression analysis showed that 25(OH)D(3), alkaline phosphatase and hemoglobin were independent risk factors for EVB. Spearman's correlation coefficient analysis showed that 25(OH)D(3)was significantly positively and negatively correlated with interleukin-6 (r= 0.306,P= 0.005) and albumin (r= -0.327,P= 0.003). Stratified analysis showed that serum 25(OH)D(3) level was lower in ALP≤140U/L group and the bleeding group, and the difference was statistically significant than non-bleeding group (P= 0.007), while the serum level of 25(OH)D(3)was decreased in both groups for alkaline phosphatase > 140 U/L group, and the difference was not statistically significant (P= 0.051). Furthermore, in the GGT > 60 U/L group, the serum level of 25(OH)D(3)was significantly lower in the bleeding group, and the difference was statistically significant in non-bleeding group (P= 0.003), while the difference between the two groups was not statistically significant (P> 0.05) in GGT≤30 U/ L, > 30 U/L, and ~≤60 U/L group. Conclusion: Serum 25(OH)D(3)level was significantly lower in EVB cirrhotic patients, and it was an independent risk factor for EVB. Serum 25(OH)D(3) low levels was more apparent with ALP normalization or GGT level > 60 U/L.

Prospective ECG-triggering cardiac CT for infants with complex congenital heart disease using low-dose contrast medium, low tube voltage, and adaptive statistical iterative reconstruction.

AIM: To demonstrate the clinical value of prospective electrocardiography (ECG)-triggered cardiac computed tomography (CT) with low concentration contrast medium, low tube voltage, and adaptive statistic iterative reconstruction (ASIR) to reduce both radiation and contrast dose in examining infants with complex congenital heart disease (CHD). MATERIALS AND METHODS: Forty-four consecutive infants (19 male, 25 female, age: 8.06±4.33 months, weight: 7.31±1.36 kg) with complex CHD underwent prospective ECG-triggered low-dose cardiac CT using 80 kVp and 120 mA. The contrast agent was iodixanol (270 mg iodine/ml, Visipaque, GE Healthcare, Co. Cork, Ireland). Cardiac CT images were reconstructed with 70% ASIR. The quantitative CT image quality was assessed by image noise in adipose tissue and contrast-to-noise ratio (CNR) in the aorta. The qualitative image analysis was performed on a five-point grading scale by two independent reviewers and interobserver variability was calculated. The results of 32 CT examinations were also compared with the available surgical results for diagnostic accuracy evaluation. RESULTS: The effective dose was 0.55±0.10 mSv for the patient population. The iodine load was 3.95±0.73 g iodine. Image noise in adipose tissue was 16.24±1.42 HU and CNR in aorta was 21.90±7.10. All images were acceptable for diagnosis with an average score of 4.52±0.38 and good agreement between reviewers (kappa=0.75). Compared to the surgery results in 32 cases, CT was 97% and 88% accurate diagnosing extracardiac and intracardiac defects, respectively. CONCLUSION: Prospective ECG-triggered cardiac CT using 80 kVp, low-concentration iodinated contrast agent (270 mg iodine/ml) and 70% ASIR reconstruction provides excellent image quality and accurate diagnosis for complex congenital heart disease in infants with reduced contrast medium dose and low radiation dose.

[Changes in peripheral blood 25 - hydroxyvitamin D3, Th17 cells, and CD4+ regulatory T cells and their clinical significance in patients with primary biliary cirrhosis].

Objective: To investigate the changes in peripheral blood 25-hydroxyvitamin D3[25-(OH)D3], CD4+regulatory T (Treg) cells, and Th17 cells in patients with primary biliary cirrhosis (PBC) and their mechanism of action in PBC. Methods: A total of 22 patients with PBC were enrolled and the male/female ratio was 1:21, with a mean age of 61±12 years. There were 7 healthy volunteers matched for age in the normal control group. Electrochemiluminescence immunoassay was used to measure the peripheral blood 25-(OH)D3level in the PBC group and normal control group, and flow cytometry was used to analyze the changes in Th17 cells and CD4+Treg cells. The t-test, rank sum test, Pearson correlation analysis, or Spearman's rank correlation analysis was used for statistical analysis according to the type of the data. Results: The PBC group had a significantly lower serum 25-(OH)D3level than the normal control group (9.49±3.65 vs 27.35±2.35 ng/ml,P< 0.01). Compared with the normal control group, the PBC group had a significantly higher percentage of Th17 cells (2.05%±1.17% vs 0.99%±0.12%,P< 0.01) and a significantly lower percentage of CD4+Treg cells (2.54%±1.14% vs 3.78%±0.51%,P< 0.05); there was a significant difference in Th17/Treg ratio between the PBC group and the normal control group (1.00±0.63 vs 0.26±0.02,P< 0.01). In the PBC group, peripheral blood 25-(OH)D3 was not correlated with Th17 cells or Th17/Treg ratio (r= -0.062 and -0.328,P> 0.05), while it was positively correlated with the percentage of CD4+Treg cells (r= 0.468,P< 0.05). Conclusion: Patients with PBC have significant reductions in peripheral blood 25-(OH)D3and percentage of CD4+Treg cells, a significant increase in the percentage of Th17 cells, and immune unbalance of Th17 cells and CD4+Treg cells. 25-(OH)D3can upregulate the percentage of CD4+Treg cells and thus affect the development and progression of PBC, and exogenous vitamin D may improve immune function in PBC patients.

Retrospective Analysis of Childhood Hepatoblastoma in a Single Centre in China.

AIMS: To investigate the protocol efficacy and prognostic factors for paediatric hepatoblastoma in a multidisciplinary model in our centre. MATERIALS AND METHODS: Consecutive hepatoblastoma patients (<18 years old) treated at Shanghai Children's Medical Center in China from August 2011 to October 2017 were analysed retrospectively for clinical features, chemotherapy courses, surgical treatment and outcomes. RESULTS: One hundred and four cases of paediatric hepatoblastoma (64 males, 40 females; median age at diagnosis 1.64 years) had a median follow-up of 30.68 months (range 8.3-73.3 months). First complete remission was achieved in 95 cases, 85 of which achieved continuous complete remission. Another three cases were lost to follow-up after a median of 24.73 months in complete remission. Seven cases relapsed later, with two achieving a second complete remission and four deaths. Nine cases did not achieve complete remission and five of them died. In general, the 5-year overall survival rate and 5-year event-free survival (EFS) rate were 86.3 ± 5.0% and 81.8 ± 4.3%, respectively. Thirty-two cases were classified as standard risk and 72 as high risk with 5-year EFS of 96.8 ± 3.2% and 75.7 ± 5.7% (P = 0.029) and 5-year overall survival of 100% and 80.5 ± 7.0%, respectively. The mean platelet count (P = 0.0036), lactate dehydrogenase (P = 0.0443) and ferritin level (P = 0.0006) at diagnosis were much higher in the high-risk group than in the standard-risk group. Univariate analysis showed that patients <5 years of age (P = 0.018), with higher α-fetoprotein (AFP) level (>100 ng/ml, P = 0.008), without metastases at diagnosis (P = 0.001) and postoperative AFP recovery after no more than three chemocycles (P = 0.014) had better overall survival. In addition, the above factors, except metastases at diagnosis and risk group, were associated with prognosis in the multivariate analysis. CONCLUSIONS: The result of this protocol had similar overall survival and EFS rates compared with those in developed countries. Normal postoperative AFP levels after three chemocycles has prognostic value.

Expression of somatostatin receptor subtype 5 in rat retinal amacrine cells.

Somatostatin (SRIF), as a neuroactive peptide in the CNS, exerts its actions via five subtypes of specific receptors (ssts). In this work, the localization of sst(5) was studied immunocytochemically in rat retinal amacrine cells (ACs). Labeling for sst(5) was diffusely distributed throughout the full thickness of the inner plexiform layer (IPL) and formed two distinct fluorescence bands in the distal part of the IPL. Double labeling experiments showed that sst(5) was expressed in GABAergic ACs. It was further shown that labeling for sst(5) was observed in both dopaminergic and cholinergic ACs, stained by tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT), respectively. The immunostaining appeared mainly on the cell membranes and somatodendritic compartments of these ACs. For the cholinergic ACs, weak sst(5)-immunoreactivity was also observed in the processes terminating in the IPL. In contrast, no sst(5)-immunoreactivity was found in glycinergic AII ACs, stained by parvalbumin (PV). Furthermore, labeling for SRIF was co-localized with sst(5) in both dopaminergic and cholinergic ACs. These results suggest that sst(5) may serve as an autoreceptor or conventional receptor in retinal ACs.

CDH17 is a downstream effector of HOXA13 in modulating the Wnt/ß-catenin signaling pathway in gastric cancer.

OBJECTIVE: In this study, we investigated the mechanism underlying co-upregulation of HOXA13 and CDH17 in gastric cancer, the signaling pathway in which HOXA13 and CDH17 involve in and their functional role in gastric cancer cells. MATERIALS AND METHODS: Relevant microarrays investigated the dysregulated genes in gastric cancer tissues were searched in ArrayExpress. The co-expression of HOXA13 and CDH17 was analyzed in the gastric cancer patient cohort in TCGA database using cBioportal and UCSC Xena. The regulative effect of HOXA13 on CDH17 expression was examined by dual luciferase assay. The involvement of HOXA13 and CDH17 in the Wnt/beta-catenin signaling pathway was assessed by Western blotting. The functional role of HOXA13 and CDH17 in gastric cancer cells were studied by CCK-8 assay of cell growth, Transwell assay of cell invasion and flow cytometry of active caspase-3. RESULTS: HOXA13 and CDH17 expression are upregulated and are highly correlated in gastric cancer tissues. HOXA13 overexpression significantly increased CDH17 mRNA and protein expression and also significantly increased the transcription activity of the luciferase reporter with integrate HOXA13 binding sites. HOXA13 shRNA and CDH17 shRNA had similar effect on reducing the expression of beta-catenin, while shCDH17 abrogated HOXA13 induced upregulation of beta-catenin. HOXA13 shRNA and CDH17 shRNA decreased cell proliferation and invasion and increased cell apoptosis in SGC-7901 cells. CONCLUSIONS: HOXA13 can elevate CDH17 transcription via binding to its promoter. CDH17 is a downstream effector of HOXA13 in modulating the Wnt/beta-catenin signaling pathway in gastric cancer cells. Both HOXA13 shRNA and CDH17 shRNA can decrease gastric cancer cell proliferation and invasion and increase their apoptosis.

Orexin-A potentiates L-type calcium/barium currents in rat retinal ganglion cells.

Two neuropeptides, orexin-A and orexin-B (also called hypocretin-1 and -2), have been implicated in sleep/wake regulation, feeding behaviors via the activation of two subtypes of G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). While the expression of orexins and orexin receptors is immunohistochemically revealed in retinal neurons, the function of these peptides in the retina is largely unknown. Using whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that orexin-A increased L-type-like barium currents (IBa,L) in ganglion cells (GCs), and the effect was blocked by the selective OX1R antagonist SB334867, but not by the OX2R antagonist TCS OX2 29. The orexin-A effect was abolished by intracellular dialysis of GDP-ß-S/GPAnt-2A, a Gq protein inhibitor, suggesting the mediation of Gq. Additionally, during internal dialysis of the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor U73122, orexin-A did not change the IBa,L of GCs, whereas the orexin-A effect persisted in the presence of the phosphatidylcholine (PC)-PLC inhibitor D609. The orexin-A-induced potentiation was not seen with internal infusion of Ca(2+)-free solution or when inositol 1,4,5-trisphosphate (IP3)-sensitive Ca(2+) release from intracellular stores was blocked by heparin/xestospongins-C. Moreover, the orexin-A effect was mimicked by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, but was eliminated when PKC was inhibited by bisindolylmaleimide IV (Bis-IV)/Gö6976. Neither adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) nor guanosine 3',5'-cyclic monophosphate (cGMP)-protein kinase G (PKG) signaling pathway was likely involved, as orexin-A persisted to potentiate the IBa,L of GCs no matter these two pathways were activated or inhibited. These results suggest that, by activating OX1R, orexin-A potentiates the IBa,L of rat GCs through a distinct Gq/PI-PLC/IP3/Ca(2+)/PKC signaling pathway.

Red ginseng ameliorated place navigation deficits in young rats with hippocampal lesions and aged rats.

Effects of hippocampal lesions and aging on spatial learning and memory and ameliorating effects of red ginseng on learning deficits were investigated in the following two experiments: performance of young rats with selective hippocampal lesions with red ginseng by mouth (p.o.; Experiment 1) and aged rats with red ginseng (p.o.; Experiment 2) in the spatial tasks was compared with that of sham-operated or intact young rats. Each rat in these two behavioral experiments was tested with the three types of spatial-learning tasks (distance movement task, DMT; random-reward place search task, RRPST; and place-learning task, PLT) in a circular open field using intracranial self-stimulation as reward. The results in the DMT and RRPST tasks indicated that motivational and motor activity of young rats with hippocampal lesions with and without ginseng were not significantly different from that of sham-operated young rats in Experiment 1. However, young rats with hippocampal lesions displayed significant deficits in the PLT task. Treatment with red ginseng significantly ameliorated place-navigation deficits in young rats with hippocampal lesions on the PLT task. Similarly, red ginseng improved performance of aged rats on the PLT task in Experiment 2. The results, along with previous studies showing significant effects of red ginseng on the central nervous system, suggest that red ginseng ameliorates learning and memory deficits through effects on the central nervous system, partly through effects on the hippocampal formation.

Cellular localization of P2Y6 receptor in rat retina.

Extracellular nucleotides exert their actions via two subfamilies of purinoceptors: P2X and P2Y. Eight mammalian P2Y receptor subtypes (P2Y(1,2,4,6,11,12,13,14)) have been identified. In this work, the localization of P2Y(6) was studied in rat retina using double immunofluorescence labeling and confocal scanning microscopy. Immunostaining for P2Y(6) was strong in the outer plexiform layer and was diffusely distributed throughout the full thickness of the inner plexiform layer. In addition, P2Y(6) immunoreactivity was clearly observed in many cells in the inner nuclear layer and the ganglion cell layer. In the outer retina photoreceptor terminals, labeled by VGluT1, and horizontal cells, labeled by calbindin, were P2Y(6)-positive. However, no P2Y(6) immunostaining was detected in bipolar cells, labeled by homeobox protein Chx10. In the inner retina P2Y(6) was localized to most of GABAergic amacrine cells, including dopaminergic and cholinergic ones, stained by tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) respectively. Some of glycinergic amacrine cells, but not glycinergic AII amacrine cells, were also labeled by P2Y(6). Moreover, P2Y(6) immunoreactivity was seen in almost all ganglion cells, labeled by Brn3a. In Müller glial cells, stained by cellular retinaldehyde binding protein (CRALBP), however, no P2Y(6) expression was found in both somata and processes. We speculate that P2Y(6) may be involved in retinal information processing in different ways, probably by regulating the release of transmitters and/or modulating the radial flow of visual signals and lateral interaction mediated by horizontal and amacrine cells.

Gene expression and protein distribution of orexins and orexin receptors in rat retina.

Orexins, composed of orexin A and orexin B, are identified as endogenous ligands of two orphan G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). Orexins are implicated in regulating wake/sleep states, feeding behaviors, etc. Using reverse transcription-polymerase chain reactive (RT-PCR) analysis and immunofluorescence double labeling, we investigated the distributions of orexin A, orexin B, OX1R and OX2R in rat retina. RT-PCR analysis revealed the presence of mRNAs of prepro-orexin, OX1R and OX2R in rat retina. Immunostaining for orexin A and orexin B was observed in many cells in the inner nuclear layer and the ganglion cell layer. In the outer retina, horizontal cells, labeled by calbindin, and bipolar cells, labeled by homeobox protein Chx10, were orexin A- and orexin B-positive. In the inner retina, two orexins were both found in GABAergic amacrine cells (ACs), including dopaminergic and cholinergic ones, stained by tyrosine hydroxylase and choline acetyltransferase respectively. Glycinergic ACs, including AII ACs, also expressed orexins. Weak to moderate labeling for orexin A and orexin B was diffusely distributed in the inner plexiform layer. Additionally, orexins were expressed in almost all ganglion cells (GCs) retrogradely labeled by cholera toxin B subunit. Specifically, double-labeling experiments demonstrated that melanopsin-positive GCs (intrinsically photosensitive retinal GCs, ipRGCs) were labeled by two orexins. Morever, OX1R immunoreactivity was observed in most of GCs and all dopaminergic ACs, as well as in both outer and inner plexiform layers. In contrast, no obvious OX2R immunostaining was detectable in the rat retina. These results suggest that orexins may modulate the function of neurons, especially in the inner retina. We further hypothesize that the orexin signaling via ipRGCs may be involved in setting the suprachiasmatic nucleus (SCN) circadian clock.

Activation of the ζ receptor 1 suppresses NMDA responses in rat retinal ganglion cells.

The sigma receptor 1 (σR1) has been shown to modulate the activity of several voltage- and ligand-gated channels. Using patch-clamp techniques in rat retinal slice preparations, we demonstrated that activation of σR1 by SKF10047 (SKF) or PRE-084 suppressed N-methyl-D-aspartate (NMDA) receptor-mediated current responses from both ON and OFF type ganglion cells (GCs), dose-dependently, and the effect could be blocked by the σR1 antagonist BD1047 or the σR antagonist haloperidol. The suppression by SKF of NMDA currents was abolished with pre-incubation of the G protein inhibitor GDP-ß-S or the Gi/o activator mastoparan. We further explored the intracellular signaling pathway responsible for the SKF-induced suppression of NMDA responses. Application of either cAMP/the PKA inhibitor Rp-cAMP or cGMP/the PKG inhibitor KT5823 did not change the SKF-induced effect, suggesting the involvement of neither cAMP/PKA nor cGMP/PKG pathway. In contrast, suppression of NMDA responses by SKF was abolished by internal infusion of the phosphatidylinostiol-specific phospholipase C (PLC) inhibitor U73122, but not by the phosphatidylcholine-PLC inhibitor D609. SKF-induced suppression of NMDA responses was dependent on intracellular Ca2+ concentration ([Ca2+]i), as evidenced by the fact that the effect was abolished when [Ca2+]i was buffered with 10 mM BAPTA. The SKF effect was blocked by xestospongin-C/heparin, IP3 receptor antagonists, but unchanged by ryanodine/caffeine, ryanodine receptor modulators. Furthermore, application of protein kinase C inhibitors Bis IV and Gö6976 eliminated the SKF effect. These results suggest that the suppression of NMDA responses of rat retinal GCs caused by the activation of σR1 may be mediated by a distinct [Ca2+]i-dependent PLC-PKC pathway. This effect of SKF could help ameliorate malfunction of GCs caused by excessive stimulation of NMDA receptors under pathological conditions.

Expression of sigma receptor 1 mRNA and protein in rat retina.

Sigma receptor (sigmaR), known as a unique nonopiate, nonphencyclidine brain receptor, can bind diverse classes of psychotropic drugs, neurosteroids and other synthetic compounds, such as (+)pentazocine, etc. Two types of sigmaRs have been identified: sigmaR1 and sigmaR2. In this work, we examined the expression of sigmaR1 in rat retina by reverse transcription-polymerase chain reactive (RT-PCR) analysis and immunofluorescence double labeling. RT-PCR analysis showed that sigmaR1 mRNA was present in rat retina. Furthermore, labeling for sigmaR1 was diffusely distributed in the outer and inner plexiform layers. The sigmaR1-immunoreactivity (IR) was also observed in many cells in the inner nuclear layer and the ganglion cell layer. In the outer retina sigmaR1 was expressed in all horizontal cells labeled by calbindin. In contrast, no sigmaR1-IR was detected in several subtypes of bipolar cells, including rod-dominant ON-type bipolar cells, types 2, 3, 5 and 8 bipolar cells, labeled by protein kinase C (PKC), recoverin and hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4) respectively. In the inner retina, most of GABAergic amacrine cells, including dopaminergic and cholinergic ones, stained by tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) respectively, expressed sigmaR1. Some glycinergic amacrine cells were also labeled by sigmaR1, but glycinergic AII amacrine cells were not labeled. In addition, sigmaR1-IR was seen in almost all somata of the ganglion cells retrogradely labeled by fluorogold. These results suggest that sigmaR1 may have neuromodulatory and neuroprotective roles in the retina.

Expression of connexin 35/36 in retinal horizontal and bipolar cells of carp.

Connexin 35/36 (Cx35/36) gap junction protein is expressed in various regions of the brain, including the retina. In this work, the expression of Cx35/36 in the outer retina of carp was studied by immunocytochemistry. By light microscopy, strong punctate Cx35/36-immunoreactivity was observed in the outer plexiform layer. Double labeling experiments on vertical retinal sections showed that Cx35/36 puncta were localized beneath cone pedicles, stained by recoverin, but not on them. In addition, few of the dendrites of rod-dominant ON type bipolar cells (rod-ON-BCs), stained by PKCalpha, were labelled with Cx35/36 in the retinal sections. In isolated cell preparations, Cx35/36 was clearly expressed on the dendrites of cone-dominant ON type bipolar cells (cone-ON-BCs), but the expression was much less on rod-ON-BCs. Moreover, Cx35/36 puncta were found in the dendrites of isolated horizontal cells (labelled by GAD 65/67) driven by cones, including H1 and H2 cells, but not in those of cells driven by rods (H4 cells). At the ultrastructural level, reaction product was found in H1 and H2 cell dendrites invaginating cone terminals, but not in H4 cell dendrites invaginating rod terminals. Moreover, dendrites of cone-ON-BCs, were also labebed. These results suggest that Cx35/36 could be specifically involved in modulation of the cone signal pathway in the outer retina of carp.

A modified electrocardiographic algorithm for differentiating typical atrioventricular node re-entrant tachycardia from atrioventricular reciprocating tachycardia mediated by concealed accessory pathway.

Non-invasive prediction of tachycardia mechanism is becoming clinically important in the era of catheter ablation for curing supraventricular tachycardia. Twelve-lead electrocardiograms (ECGs) during sinus rhythm and atrioventricular node re-entrant tachycardia (AVNRT) or atrioventricular reciprocating tachycardia (AVRT) with a narrow QRS complex were obtained from 154 consecutive adult patients who had received successful radiofrequency catheter ablation. The ECGs of initial 104 patients were analysed by three observers without knowledge of the electrophysiological diagnosis. The two arrhythmias were accurately diagnosed in 68% of cases. Three criteria were found to be discriminators of tachycardia mechanism by univariable analysis. Pseudo r/Q/S waves predicated AVNRT in 92% of cases (sensitivity 71%; specificity 95%). Retrograde P wave predicated AVRT in 86% of cases (sensitivity 75%; specificity 85%), RP interval > or =100 ms in 93% (sensitivity 71%; specificity 94%) and ST-segment elevation in lead aVR in 83% (sensitivity 71%; specficity 83%). According to the initial results, we proposed a modified stepwise ECG algorithm which used pseudo r/S/Q waves, RP interval and ST-segment elevation in lead aVR during tachycardia. Two observers assessed the modified algorithm in the remaining 50 patients. The algorithm was able to correctly diagnose the tachycardia mechanism in 84% and 87%, respectively. Using the modified algorithm can improve the accuracy and simplify the differential diagnosis between typical AVNRT and AVRT via concealed accessory pathway in adult patients.