[Therapeutic efficacy of transoral robotic surgery with the da Vinci robot system for the treatment of oropharyngeal squamous cell carcinoma]

Objective: To evaluate the clinical efficacy of transoral robotic surgery (TORS) with the da Vinci robot system in the treatment of oropharyngeal squamous cell carcinoma (OPSCC). Methods: A mixed cohort study was conducted to collect and analyze the clinical data of OPSCC patients who underwent TORS at the Eye & ENT Hospital, Fudan University between July 2020 and February 2023 (TORS group). OPSCC patients who underwent conventional surgery between January 2016 and September 2020 were included as the control group. The baseline information, incidence of complications and follow-up data were compared between the two groups. Results: A total of 166 patients were included, with 102 cases (81 males and 21 females) in the TORS group [mean age: (59.1±9.8) years] and 64 cases (54 males and 10 females) in the control group [ mean age: (57.6±9.7) years]. Compared with the control group, the TORS group had lower postoperative bleeding rate [2.9% (3/102) vs 10.9% (7/64), P=0.035] and infection rate [1.0% (1/102) vs 18.8% (12/64), P<0.001]. No statistically significant differences were observed in tracheotomy rate [46.1% (47/102) vs 59.4% (38/64), P=0.070] and median length of hospital stay [8 (7, 10) d vs 10 (4, 12) d, P=0.088]. After propensity score matching, compared with the control group, the TORS group had lower postoperative infection rate [0 (0/31) vs 19.4% (6/31), P=0.032] and median length of hospital stay [7 (7, 10) d vs 10 (8, 12) d, P=0.031]. No statistically significant differences were found in postoperative bleeding rate [3.2% (1/31) vs 6.5% (2/31), P=1.000] and tracheotomy rate [22.6% (7/31) vs 45.2% (14/31), P=0.060] between the two groups. Moreover, 1-and 2-year disease-free survival rates were 96.3% and 94.6% in the TORS group, and 90.6% and 84.3% in the control group, respectively (P=0.233). The 1-and 2-year cancer-specific survival rates were both 100% in the TORS group, and 96.9% and 93.8% in the control group, respectively (P=0.539). Conclusion: TORS for OPSCC is associated with high clinical safety and favorable oncological outcomes.

[Comparison of the efficacy of carelizumab combined with chemotherapy and chemotherapy alone in the induction therapy of locally advanced hypopharyngeal carcinoma]

Objective: To compare the efficacy and safety of carrelizumab combined with the modified TPF regimen (docetaxel, cisplatinand capecitabine) and TPF regimen alone in larynx preservation strategy for locally advanced resectable hypopharyngeal squamous cell carcinoma. Methods: A cohort study was conducted. Patients with locally advanced resectable hypopharyngeal carcinoma (cT3-4aN0-3bM0) who were treated at the Eye & ENT Hospital of Fudan University from January 2017 to April 2023 were enrolled in the study. One group was treated with a modified TPF regimen (TPF group) for 2-3 cycles (retrospective data), and the other group was a prospective phase Ⅱ trial with a modified TPF regimen combined with carrelizumab (TPFC group) for three cycles. The patients with complete or partial remission of the primary focus were treated with sequential radical radiotherapy and/or drug therapy. The patients in the TPFC group were treated with carrelizumab at the end of radiotherapy with a maximum of up to 18 doses. The patients with stable or progressive disease were given radical surgery, and those who refused the surgery were given radical chemoradiotherapy. Objective response rate (ORR), overall survival rate, progression-free survival (PFS) rate, larynx preservation rate (LPR), and adverse reactions were compared between the two groups. Results: There were 51 male patients in the TPFC group, with an median age of 57 (35, 69) years. Meanwhile, 44 patients were in the TPF group, among which 43 were male and one was female, with an median age of 62 (46, 70) years. The ORR of the TPFC group was higher than that of the TPF group [82.4% (42/51) vs 63.6% (28/44), P=0.039]. During a median follow-up of 24.4 (18.5, 31.4) months, the TPFC group showed a higher 2-year survival rate (84.8% vs 64.6%, P=0.013) and 2-year LPR (66.6% vs 48.6%, P=0.045) than those in the TPF group. In patients with poor effect of induction therapy for hypopharyngeal carcinoma, surgical combination therapy significantly prolonged the 2-year PFS rate (77.9% vs 18.2%, P<0.001) and 2-year survival rate (76.9% vs 45.5%, P=0.005)than those of non-surgical combination therapy. The incidences of nausea and/or vomiting, reactive cutaneous capillary endothelial proliferation, thyroid dysfunction, and rash were increased in the TPFC group (all P<0.05). There was no treatment-related death. Conclusion: Carrelizumab combined with a modified TPF regimen has good efficacy and safety and can improve the LPR of locally advanced hypopharyngeal carcinoma.

[Clinical efficacy of induction chemoimmunotherapy for locally advanced hypopharyngeal carcinoma: a prospective phase Ⅱ study]

Objective: To evaluate the objective response rate (ORR) of induction chemoimmunotherapy with camrelizumab plus TPF (docetaxel, cisplatin, and capecitabine) for locally advanced hypopharyngeal squamous cell carcinoma (LA HSCC) and potential predictive factors for ORR. Methods: A single-center, prospective, phase 2 and single-arm trial was conducted for evaluating antitumor activity of camrelizumab+TPF(docetaxel+cisplatin+capecitabine) for LA HSCC between May 21, 2021 and April 15, 2023, patients admitted to the Eye & ENT Hospital affiliated with Fudan University. The primary endpoint was ORR, and enrolled patients with LA HSCC at T3-4N0-3M0 received induction chemoimmunotherapy for three cycles: camrelizumab 200 mg day 1, docetaxel 75 mg/m2 day 1, cisplatin 25 mg/m2 days 1-3, and capecitabine 800 mg/m2 days 1-14. Patients were assigned to radioimmunotherapy when they had complete response or partial response (PR)>70% (Group A), or assigned to surgery plus adjuvant radiotherapy/chemoradiotherapy when they had PR≤70% (Group B), and the responses were defined by using tumor volume evaluation system. Tumor diameter was also used to assess the treatment responses by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Use SPSS 23.0 software was used to analyze the data. Results: A total of 51 patients were enrolled who underwent the induced chemoimmunotherapy for three cycles, and all were males, aged 35-69 years old. After three cycles of induction immunochemotherapy, 42 (82.4%) patients existed in Group A (complete response or PR>70%) and 9 patients (17.6%) in Group B (PR≤70%), the ORR was 82.4%. The primary endpoint achieved expected main research objectives. Compared to the patients of Group A, the patients of Group B showed the higher T stage and the larger volume of primary tumor before induced immunochemotherapy, and also had the less regression of tumor volume after induced immunochemotherapy (all P<0.05). The optimal cutoff value of pre-treatment tumor volume for predicting ORR was 39 cm3. The T stage (OR=12.71, 95%CI: 1.4-112.5, P=0.022) and the volume (OR=7.1, 95%CI: 1.4-36.8, P=0.018) of primary tumor were the two main factors affecting ORR rate of induction chemoimmunotherapy. Conclusion: The induction chemoimmunotherapy with camrelizumab plus TPF shows an encouraging antitumor efficacy in LA HSCC.

[Indications and complications prevention and management of phaseⅡ implantation of Provox Vega voice prosthesis after total laryngectomy]

Objective: To explore the indications and management of common postoperative complications of phase II tracheoesophageal puncture (TEP) for Provox Vega voice prosthesis after total laryngectomy. Methods: The clinical data of 20 patients undergoing phase II TEP for Provox Vega voice prosthesis in our hospital between May 2021 and January 2022 were analyzed. Among them, there were 19 males and 1 female, aged from 37 to 76 years, with an average age of (60.0±8.4)years. The surgical indications and the prevention and treatment of common postoperative complications were summarized. Descriptive analysis was used in this research. Results: The basic surgical indications were as following: after total laryngectomy, there was no stenosis of the stoma and esophagus entrance, no scar constitution, no mouth opening restriction, no stiffness and backward restraint of the neck after radiotherapy, and more than half a year apart surgery or radiotherapy. Among the 20 patients, 18 underwent implantation successfuly, 1 failed in the operation, and for 1 patient, the prosthesis was removed due to bleeding 1 week after implantation. The common postoperative complications included TEP fistula infection (2 cases), the TEP fistula bleeding(1 case), deep neck (prevertebral) abscess (1 case), granulation at the inner side of the TEP fistula (1 case), invagination of the prosthesis (2 cases) and leakage around the prosthesis (2 cases). All patients were cured with different interventions. Conclusions: The Provox Vega voice prosthesis is generally safe for phase Ⅱ implantatione, but implantation indications need to be established. Common postoperative complications can be solved through preventive and remedial interventions.

[Feasibility and perioperative safety of transoral robotic surgery with da Vinci Xi platform]

Objective: To explore the feasibility and perioperative safety of transoral robotic surgery with da Vinci Xi platform for pharyngolaryngeal tumors. Methods: A retrospective analysis was performed on 55 consecutive cases with resection of pharyngolaryngeal tumors by transoral robotic surgery with da Vinci Xi platform from July 27, 2020 to October 31, 2021 in the Department of Head and Neck Surgery, Fudan University Eye, Ear, Nose and Throat Hospital, including 44 males and 11 females, aged 25-79 years. There were 41 cases of oropharyngeal tumors, 9 cases of parapharyngeal space tumors, 2 cases of laryngeal tumors, 2 cases of hypopharyngeal tumors and 1 case of retropharyngeal space tumor. Operative time, intraoperative blood loss, postoperative hospital stay, perioperative tracheotomy, nasal feeding, hemorrhage and other complications were analyzed. Results: Of the 55 patients, 54 received resection of pharyngolaryngeal tumors by da Vinci robot through oral approach, and only 1 case of pyriform sinus carcinoma underwent a conversion to open surgery due to poor exposure of lower margin. The average surgical time for the patients with transoral robotic surgeries was 64.4 min, the average blood loss was 24.8 ml, the average postoperative hospital stay was 6.9 d, and the average oral feeding time was 11.1 d. Seventeen patients (30.9%) underwent preventive tracheotomy during surgery. Among 38 cases of laryngeal cancer, 28 underwent simultaneously neck dissection. No serious complications occurred in all patients during and after operation. The follow-up time was 1-15 months. Aside from 1 patient had a relapse 10 months after surgery, other patients had no recurrence or metastasis. Conclusion: Transoral robotic surgery with da Vinci Xi is safe, effective and minimally invasive for resection of pharyngolaryngeal tumors under reasonable indications.

SPHK2 protein expression, Ki-67 index and infiltration of tumor-associated macrophages (TAMs) in human glioma

INTRODUCTION

Sphingosine kinases (SPHKs), the Ki-67 index and tumor-associated macrophages (TAMs) are associated with diverse human malignancies, including glioma. SPHK2, a subtype of SPHKs, has not been assessed in glioma or correlated with the Ki-67 index or TAM infiltration. We tested the hypothesis that expression of SPHK2 correlates with the Ki-67 index and TAM infiltration in patients with glioma.

MATERIALS AND METHOD

Western blot analysis was performed on protein lysates prepared from human astrocyte (HA) and glioma cell lines. Immunofluorescence was used to determine the subcellular location of SPHK2 protein in glioma cells. Next, immunohistochemistry was employed to analyze the correlations among SPHK2, Ki-67, CD68, and CD206 in 11 non-neoplastic brain tissues and 60 glioma tissues. All slides were evaluated under ×400 magnification, and the ratio of positively stained cells to the total number of cells was calculated for analysis.

RESULTS

SPHK2, CD68 and CD206 were all increased in glioma tissues compared to non-neoplastic brain tissues, but there were no differences between WHO grades of glioma. Ki-67 was highest in WHO grade IV tumors and lowest in non-neoplastic brain tissues, and all between-group differences were statistically significant. Moreover, SPHK2 expression was positively correlated with the Ki-67, CD68 and CD206 indexes. Finally, the CD68 and CD206 indexes were both associated with the Ki-67 index.

CONCLUSION

SPHK2 protein expression, the Ki-67 index and TAM infiltration in human glioma tissue were reported in this study for the first time. SPHK2 was positively associated with TAM infiltration and glioma proliferation. Mechanistically, SPHK2 may promote glioma growth by stimulating TAMs to polarize M2-type macrophages.

[Effect of preoperative monocyte-lymphocyte ratio on prognosis of patients with resectable esophagogastric junction cancer]

Objective: To investigate the associations between various blood test parameters including MLR (monocyte-lymphocyte ratio) and prognosis in post-operative esophagogastric junction cancer patients. Methods: We retrospectively studied the preoperative and postoperative data of 309 patients who underwent radical surgery for esophagogastric junction cancer. The relationship between MLR, neutrophil lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and overall survival (OS) was analyzed. Results: The cutoff values of MLR、NLR and PLR were 0.201, 1.697 and 96.960, respectively. The median OS was 51.4 months for all the patients in the study group (n=309). MLR in patients with esophagogastric junction carcinoma was associated with gender, depth of invasion, histological grade, TNM stage, NLR and PLR (P<0.05). PLR was associated with tumor size, TNM stage, NLR and MLR (P<0.05). NLR was associated with gender, tumor size, TNM stage, PLR and MLR (both P<0.05). Univariate analysis showed that tumor size, depth of tumor invasion, metastasis of lymph nodes, pathological grading, nerve infiltration, lymphovascular invasion, TNM staging, PLR and MLR were associated with the median overall survival time (P<0.05). Multivariate analysis showed that TNM stage, nerve infiltration and MLR were independent prognostic predictors for patients with esophagogastric junction cancer (P<0.05), but not PLR or NLR. Setting the optimal cut-off value of the MLR in 0.201, the area under the curve was 0.603, significantly larger than that of PLR and NLR (P<0.05). Conclusions: Preoperative MLR is a very useful predictor of patients with esophagogastric junction cancer who underwent radical rescetion. Preoperative MLR> 0.201 is an independent risk factor for postoperative survival in patients with esophagogastric cancer, and PLR> 96.960 may predict a poor prognosis risk.

[Changes of the expression for genes related with senescence and the telomerase activity during cellular replicative and premature senescence in human embryonic lung fibroblasts]

Objective: To detect the alterations of telomerase activity and the expression for oxidative stress responsive genes related with senescence during cellular replicative senescence and hydrogen peroxide-induced premature senescence in human embryonic lung fibroblasts (HELFs) in vitro. Methods: The HELFs were divided into young cells (22 population doubling levels, 22PDL) , mid-aged cells (35PDL) and replicative senes-cent cells (49PDL) and premature senescent cells induced by H(2)O(2)(premature senescence, PS). The telomerase activity was detected by ELISA assay during cellular replicative and premature senescence. The mRNA level of oxidative stress responsive genes related with senescence for Foxo1, Foxo3, Pdx1, apoA-I and MMP1 was per-formed by RT-Q-PCR separately. Results: The mRNA level for Foxo1, Foxo3, apoA-I and Pdx1 was decreased separately during cellular replicative senescence compared to that in the young-stage cells with statistical signifi-cance (P<0.05). The expression of MMP1 was up-regulated 5.1-fold obviously (P<0.05). In premature senes-cence, the mRNA level was only decreased for Foxo1, Foxo3 and apoA-I, but up-regulated 2.3-fold and 6.2-fold for Pdx1 and MMP1 respcetively vs 22PDL significantly (P<0.05). The telomerase activity in young cells was not detected, and it increased in mid-aged cells and replicative senescence stages during cellular replicative se-nescence as compared to 22PDL with statistical significance (P<0.05). The telomerase activity in premature se-nescence was highly active. Conclusion: The expression for genes related with senescence has differences be-tween replicative and premature senescence and hydrogen peroxide modifies their expression levels. The telomer-ase activity has been going up with increased PDLs.

Secondhand smoke exposure of children at home and prevalence of parental smoking following implementation of the new tobacco control law in Macao

OBJECTIVE

To investigate secondhand smoke exposure (SHS) of children at home and the prevalence of parental smoking after implementation of the new tobacco control law in Macao. This study explored whether the smoking ban in public places in Macao has decreased the prevalence of smoking or led to increased SHS exposure of children at home. As smokers cannot smoke in public places any more, they may smoke at home more frequently; a displacement effect of smoke-free legislation.

STUDY DESIGN

Cross-sectional survey.

METHODS

This study surveyed 337 fathers and 538 mothers. Questions from a subset of key questions from the Global Adult Tobacco Survey (2nd edition) were applied to assess the SHS exposure of children and the prevalence of parental smoking since the smoking ban. A classification tree analysis was used to analyse the factors increasing SHS exposure of children.

RESULTS

The prevalence of SHS exposure in children at home was 41.3%. The prevalence rates of paternal and maternal smoking were 43.7% and 3.8%, respectively. Compared with data reported by the Health Bureau of Macao SAR in 2011, the prevalence of parental smoking and the prevalence of SHS exposure of children at home have not decreased since the smoking ban. Analysis of the factors increasing the prevalence of SHS exposure of children indicated that fathers with an education level below high school were more likely to contribute to this increase, compared with fathers with a high school education or more (48.2% vs 32.4%, respectively). In addition, fathers represented the majority of smokers at home, accounting for 92.0% of 415 smoking parents. The prevalence of paternal smoking (82.0%) in the group of children with SHS exposure was much higher than that in the unexposed group (16.7%, Chi-squared test = 367.199, P = 0.000). The SHS exposure of children increased consistently with the decrease in paternal education level. This was consistent with the increasing prevalence of paternal smoking as paternal education level decreased. SHS exposure was most common among children whose fathers had an education level below high school and whose mothers were aged ≤29 years (75.0%).

CONCLUSIONS

This study did not find any decline in the prevalence of parental smoking after the smoking ban. These parents were more likely to smoke at home after the ban, leading to more frequent SHS exposure for their children.

Preparation and characterization of an ordered 1-dodecanethiol monolayer on bare Si(111) surface

We have grown 1-dodecandthiol (DDT) monolayer on a bare Si(111) surface through ultraviolet-assisted photochemical reaction. The resulting monolayer was investigated by means of water contact angle measurement, synchrotron radiation-based high-resolution X-ray photoelectron spectroscopy, and polarization-dependent near-edge X-ray absorption fine structure spectroscopy. These combined probes for characterization reveal a hydrophobic ambient surface; the DDT was directly attached to Si through a Si-S bond, and the molecules formed an ordered monolayer with an average tilt angle of 57° of the alkyl chains relative to the substrate surface.

Effects of supplemental copper and chromium on the serum and egg traits of laying hens

1. This study investigated the effects of supplemental copper and chromium on the serum and egg traits of laying hens using 144 forty-five-week-old White Leghorn layers. The hens were randomly assigned into 9 groups to conduct this 3 copper (0, 125 and 250 mg/kg as copper sulphate) x 3 chromium (0, 800 and 1600 microg/kg as chromium picolinate) factorial trial. 2. Egg yolk cholesterol was significantly reduced by supplementary copper (Cu) and chromium (Cr) and there was an interaction between Cu and Cr supplementation. Egg production, egg weight, eggshell strength and eggshell thickness were not influenced by Cu or Cr supplementation. 3. Serum cholesterol concentration was decreased by Cu supplementation and very low-density lipoprotein (VLDL) was reduced markedly by both Cu and Cr. On the other hand, high-density lipoprotein (HDL) was significantly increased by Cu and Cr. Interaction occurred between Cu and Cr in the VLDL and HDL parameters. Supplmentary Cu also reduced VLDL-cholesterol (VLDL-C) and enhanced HDL-cholesterol (HDL-C), while supplemental Cr had a contrary effect on these two parameters. 4. If minimum egg cholesterol content is the criterion, this study suggests that 125 mg/kg of Cu together with 800 to 1600 microg/kg of Cr provide adequate supplementary concentrations for laying hens.

Expressed transcripts associated with high rates of egg production in chicken ovarian follicles

The purpose of this study was to characterize differentially expressed transcripts associated with varying rates of egg production in Taiwan country chickens. Ovarian follicles were isolated from two strains of chicken which showed low (B) or high (L2) rates of egg production, then processed for RNA extraction and cDNA library construction. Three thousand and eight forty clones were randomly selected from the cDNA library and amplified by PCR, then used in microarray analysis. Differentially expressed transcripts (P<0.05, log(2)> or = 1.75) were sequenced, and aligned using GenBank. This analysis revealed 20 non-redundant sequences which corresponded to known transcripts. Eight transcripts were expressed at a higher level in ovarian tissue prepared from chicken strain B, and 12 transcripts were expressed at a higher level in L2 birds. These differential patterns of expression were confirmed by semi-quantitative RT-PCR. We show that transcripts of cyclin B2 (cycB2), ferritin heavy polypeptide 1 (FTH1), Gag-Pol polyprotein, thymosin beta4 (TB4) and elongation factor 1 alpha1 (EEF1A1) were enriched in B strain ovarian follicles. In contrast, thioredoxin (TXN), acetyl-CoA dehydrogenase long chain (ACADL), inhibitor of growth family member 4 (ING4) and annexin II (ANXA2) were expressed in at higher levels in the L2 strain. We suggest that our approach may lead to the isolation of effective molecular markers that can be used in selection programs in Taiwan country chickens.

Spontaneous rhythmic field potentials of isolated mouse hippocampal-subicular-entorhinal cortices in vitro

The rodent hippocampal circuit is capable of exhibiting in vitro spontaneous rhythmic field potentials (SRFPs) of 1-4 Hz that originate from the CA3 area and spread to the CA1 area. These SRFPs are largely correlated with GABA-A IPSPs in pyramidal neurons and repetitive discharges in inhibitory interneurons. As such, their generation is thought to result from cooperative network activities involving both pyramidal neurons and GABAergic interneurons. Considering that the hippocampus, subiculum and entorhinal cortex function as an integrated system crucial for memory and cognition, it is of interest to know whether similar SRFPs occur in hippocampal output structures (that is, the subiculum and entorhinal cortex), and if so, to understand the cellular basis of these subicular and entorhinal SRFPs as well as their temporal relation to hippocampal SRFPs. We explored these issues in the present study using thick hippocampal-subicular-entorhinal cortical slices prepared from adult mice. SRFPs were found to spread from the CA1 area to the subicular and entorhinal cortical areas. Subicular and entorhinal cortical SRFPs were correlated with mixed IPSPs/EPSPs in local pyramidal neurons, and their generation was dependent upon the activities of GABA-A and AMPA glutamate receptors. In addition, the isolated subicular circuit could elicit SRFPs independent of CA3 inputs. We hypothesize that the SRFPs represent a basal oscillatory activity of the hippocampal-subicular-entorhinal cortices and that the subiculum functions as both a relay and an amplifier, spreading the SRFPs from the hippocampus to the entorhinal cortex.

Synthesis and characterization of aspartic acid complexes of antimony and bismuth triiodide

New bioinorganic complexes of the aspartic acid with the antimony or bismuth triiodide were synthesized by a direct solid-solid reaction at room temperature. The formula of the complex is MI(3)[OOCCH(2)CH(NH(2))CO](2.5) x 2.5H(2)O (M = Sb, Bi). The complex may be a dimer with bridge structure. The crystal structure of the complexes belongs to a triclinic system. The lattice parameters are a = 0.9883 nm, b = 1.4284 nm, c = 2.0114 nm, alpha = 94.46 degrees , beta = 99.76 degrees and gamma = 100.1 degrees for the complex of antimony and a = 0.9756 nm, b = 1.4560 nm, c = 1.9875 nm, alpha = 94.18 degrees , beta = 97.25 degrees and gamma = 101.16 degrees for the complex of bismuth. The infrared spectra and thermal analyses can demonstrate the complex formation between the aspartic acid and the antimony or bismuth ion.

Postnatal development of intrinsic GABAergic rhythms in mouse hippocampus

The local circuitry of the mammalian limbic cortices, including the hippocampus, is capable of generating spontaneous rhythmic activities of 0.5-4 Hz when isolated in vitro. These rhythmic activities are mediated by synchronous inhibitory postsynaptic potentials in pyramidal neurons as the result of repeated discharges of inhibitory interneurons. As such, they are thought to represent an intrinsic inhibitory rhythm. It is unknown at present whether such a rhythm occurs in the immature rodent hippocampus and, if so, the postnatal time window in which it develops. We explored these issues using our recently developed whole mouse hippocampal isolate preparation in vitro. We found that spontaneous rhythmic field potentials started to emerge in mouse hippocampal isolates around postnatal day 10, stabilized after postnatal day 15 and persisted into adulthood. In postnatal days 11-14 mouse hippocampi, the properties of these rhythmic potentials were in keeping with a CA3-driven, IPSP-based intrinsic network activity. The lack of spontaneous field rhythm in neonatal (postnatal days 2-7) hippocampi cannot be attributed to the excitatory activities mediated by gamma-aminobutyric acid type A (GABA-A) receptors, as chloride-dependent hyperpolarizing inhibitory postsynaptic potentials were detectable in neonatal pyramidal neurons at voltages near resting potentials and pharmacological antagonisms of GABA-A receptors produced robust epileptiform discharges in neonatal hippocampi. High frequency afferent stimulation or applications of 4-aminopyridine at low micromolar concentrations failed to induce persistent field rhythm in neonatal hippocampi, suggesting that an overall weak glutamatergic drive is not the sole causing factor. We suggest that the inhibitory postsynaptic potential-based spontaneous rhythmic field potentials develop in a discrete time window during the second postnatal week in the mouse hippocampus due to a fine-tuning in the structure and function of CA3 recurrent circuitry and associated GABAergic inhibitory interneurons.

Ca3 neuronal activities of dorsal and ventral hippocampus are differentially altered in rats after prolonged post-ischemic survival

The aim of the present study is to explore the potential hyper-excitability of hippocampal CA3 neurons in rats after prolonged post-ischemic survival. We conducted 15-min four-vessel-occlusion ischemic episodes in rats, allowed these animals to survive for approximately 8 months and then examined the basic morphological features and population synaptic activities of CA3 neurons. In fixed tissue sections obtained from dorsal hippocampi of post-ischemic rats, we observed a complete loss of the CA1 neurons together with a shrunken CA1 sector. Extracellular recordings in slices revealed that the overall synaptic activities of dorsal hippocampal CA3 neurons were decreased in post-ischemic rats compared with sham-operated controls. Both sham control and post-ischemic ventral hippocampal neurons were capable of exhibiting intermittent spontaneous field potentials in slices. These spontaneous field potentials spread from the CA3 to the CA1 area and their generation relied on the activity of glutamate alpha-amino-3-hydroxy-5-methyl-4 isoxazole proprionic acid (AMPA) receptors. The propensity for displaying these spontaneous field potentials appeared to be greater in post-ischemic slices than sham control slices. Our data suggest that the hyper-excitability of the post-ischemic hippocampus, if it occurs, may preferentially take place in the ventral CA3 circuitry.

Preparation of new amino acid complex nanoparticles of bismuth and leucine

The new amino acid complex nanoparticles of bismuth and leucine can be prepared very easily by a room temperature solid-solid reaction. The various characterizations indicate that the formula of the complex is BiCl[(CH(3))(2)CHCH(2)CHNH(2)COO](2)1.5H(2)O. The crystal structure of the solid complex belongs to monoclinic system with the lattice parameters: a = 1.6036 nm, b = 1.9903 nm, c = 2.1979 nm and beta=108.06 degrees . The new solid complex is nanoparticles with average size about 80 nm.

Active dendrites and spike propagation in multi-compartment models of oriens-lacunosum/moleculare hippocampal interneurons

It is well known that interneurons are heterogeneous in their morphologies, biophysical properties, pharmacological sensitivities and electrophysiological responses, but it is unknown how best to understand this diversity. Given their critical roles in shaping brain output, it is important to try to understand the functionality of their computational characteristics. To do this, we focus on specific interneuron subtypes. In particular, it has recently been shown that long-term potentiation is induced specifically on oriens-lacunosum/moleculare (O-LM) interneurons in hippocampus CA1 and that the same cells contain the highest density of dendritic sodium and potassium conductances measured to date. We have created multi-compartment models of an O-LM hippocampal interneuron using passive properties, channel kinetics, densities and distributions specific to this cell type, and explored its signalling characteristics. We found that spike initiation depends on both location and amount of input, as well as the intrinsic properties of the interneuron. Distal synaptic input always produces strong back-propagating spikes whereas proximal input could produce both forward- and back-propagating spikes depending on the input strength. We speculate that the highly active dendrites of these interneurons endow them with a specialized function within the hippocampal circuitry by allowing them to regulate direct and indirect signalling pathways within the hippocampus.

GDNF acutely modulates excitability and A-type K(+) channels in midbrain dopaminergic neurons

Glial cell line-derived neurotrophic factor (GDNF) prevents lesion-induced death of midbrain dopaminergic neurons, but its function in normal brain remains uncertain. Here we show that GDNF acutely and reversibly potentiated the excitability of cultured midbrain neurons by inhibiting transient A-type K(+) channels. The effects of GDNF were limited to large, tyrosine hydroxylase (TH)-positive dopaminergic neurons, and were mediated by mitogen associated protein (MAP) kinase. Application of GDNF also elicited a MAP kinase-dependent enhancement of the excitability in dopaminergic neurons in midbrain slice. These results demonstrate an acute regulation of GDNF on ion channels and its underlying signaling mechanism, and reveal an unexpected role of GDNF in normal midbrain dopaminergic neurons.

Cytokine up-regulation in ischaemic/reperfused lungs perfused with University of Wisconsin solution and normal saline

Ischaemia/reperfusion (I/R) lung injury using University of Wisconsin solution (UW) as perfusate has not been well studied. Isolated rat lungs were challenged with various periods of ischaemia and/or reperfusion. Haemodynamics, lung weight gain (LWG), capillary filtration coefficient (K(fc)), tissue pathology, the concentrations of cytokines in the perfusate, and mRNAs for the various cytokines in the lung tissues were measured. I/R induced a permeability type of pulmonary oedema, as reflected by increases in LWG and K(fc). LWG and K(fc) in the I(45)R(60)(UW) group (45 min of ischaemia followed by 60 min of reperfusion with UW) were only 2% and 5% respectively of those in the I(45)R(60)(NS) group (where NS is normal saline). LWG and K(fc) in the UW group had both increased by 180 min, to values similar to those in the I(45)R(60)(NS) group. However, these findings show that UW was remarkably effective at preventing LWG after 60 min of reperfusion, and was more than 3-fold more effective than NS in delaying LWG. For longer ischaemic times only, or the same period of ischaemia followed by longer reperfusion periods, greater lung injury occurred. I/R lung injury also induced increased concentrations of tumour necrosis factor-alpha (TNF-alpha), interleukin 1 and interleukin 6 in the perfusate, and increased the mRNAs for these cytokines in lung tissue. A significant correlation was obtained between TNF-alpha concentration and LWG. TNF-alpha production in the I(45)R(60)(UW) group was only 7% of that in the I(45)R(60)(NS) group. However, TNF-alpha mRNA expression in the I(45)R(60)(UW) group was 80% of that in the I(45)R(60)(NS) group. This indicates that transcription/translation do not correlate well with cytokine production, and also suggests that one reason for the effectiveness of UW in delaying LWG may be because it delays TNF-alpha production. In summary, ischaemia or I/R caused a permeability-type pulmonary oedema that was associated with leucocyte infiltration and the up-regulation of various cytokines, regardless of the perfusion fluid. Except for pulmonary hypertension, less severe I/R lung injury and delayed cytokine production in lungs perfused with UW, the pattern of injury associated with I/R challenge was similar to that in lungs perfused with NS. We propose that more or long-acting protective agents are required as additives in order to modify UW to produce an optimal preservation solution.

Dexamethasone and pentastarch produce additive attenuation of ischaemia/reperfusion lung injury

The choice of an intravenous solution for the attenuation of ischaemia/reperfusion (I/R) lung injury is still a difficult one. Although 10% (w/v) pentastarch has been used in ICU settings, its use in I/R lung injury has not been well explored. We hypothesized that this synthetic colloid substance, which maintains colloid osmotic pressure and potentially 'seals' capillary leaks, in combination with an anti-inflammatory agent (i.e. dexamethasone), would ameliorate I/R lung injury. After 60 min of lung ischaemia in an isolated rat lung model, lungs were reperfused for 60 min in a closed circulating system with one of the following solutions: (1) NS (0.9% normal saline), (2) NS+Dex (dexamethasone), (3) NS+Penta (pentastarch), or (4) NS+Penta+Dex. Haemodynamic changes, lung weight gain (LWG), capillary filtration coefficient (K(fc)) and lung pathology were analysed. Results showed significantly lower values of K(fc) and LWG in pentastarch- or dexamethasone-perfused groups as compared with those in the NS group. Dexamethasone as an additive to NS+Penta further decreased K(fc) and LWG. Histopathological studies showed similar decreases in injury profiles. We conclude that reperfusion with dexamethasone and pentastarch can attenuate I/R lung injury, and that dexamethasone and pentastarch have additive effects. Our data thus suggest that the combination of a colloid substance with 'sealing effects' and an anti-inflammatory agent may provide a better reperfusion solution for patients with I/R lung injury or for lungs stored for transplant.

Use of anti-(tumour necrosis factor-alpha) antibody or 3-deaza-adenosine as additives to promote protection by University of Wisconsin solution in ischaemia/reperfusion injury

Experimental interventions that reduce ischaemia/reperfusion (I/R) lung injury can be used to improve the properties of preservation solutions. We attempted to increase the attenuation of I/R injury by University of Wisconsin solution (UW) by adding an antibody against tumour necrosis factor-alpha (TNF-alpha), to neutralize TNF-alpha, and/or by adding 3-deaza-adenosine (c3-Ado), to inhibit leucocyte adhesion and the biosynthesis of ICAM-1 (intercellular cell-adhesion molecule 1). We examined I/R injury using an isolated rat lung model. Six different solutions were perfused individually, followed by evaluation of I/R injury: (1) 0.9% NaCl (normal saline; NS), (2) NS+anti-TNF-alpha antibody, (3) UW alone, (4) UW+anti-TNF-alpha, (5) UW+c3-Ado and (6) UW+anti-TNF-alpha+c3-Ado. Haemodynamic changes, lung weight gain, capillary filtration coefficient, TNF-alpha levels and lung pathology were analysed in order to evaluate I/R injury. Compared with lungs perfused with NS, lungs treated with NS+anti-TNF-alpha showed less I/R injury. The addition of anti-TNF-alpha and/or c3-Ado to UW reduced I/R injury compared with unmodified UW. Among the six solutions tested, UW containing anti-TNF-alpha antibody reduced I/R injury to the greatest extent. We conclude that addition of anti-TNF-alpha antibody or c3-Ado protects against I/R lung injury when using UW. Further investigation of the improved properties of modified UWs would be beneficial with regard to lung transplantation research.

Effect of roxarsone inclusion in the diet on the performance and hepatic lipid metabolism of laying Tsaiya duck

1. The aim of this study was to examine the effects of roxarsone (3-nitro-4-hydroxyphenylarsonic acid) inclusion in the diet on the performance, liver function and lipid metabolism in the liver of laying Brown Tsaiya ducks. 2. Sixty 36-week-old laying ducks were selected and allocated at random into 4 dietary treatments with 3 replications for each treatment. Feeding was for 7 weeks with 3 weeks of experimental diets followed by a 4 week withdrawal period. The experimental diets were supplemented with 0, 50, 100 and 300 mg/kg roxarsone, respectively 3. Dietary inclusion of 50 or 100 mg/kg roxarsone did not significantly promote performance. Inclusion of 300 mg/kg significantly depressed (P<0.05) performance, liver weight and content, serum triacylglycerol (TG), serum nonesterified fatty acid (NEFA) and increased (P<0.05) cholesterol, creatine kinase (CK) and aspartate aminotransferase (AST) in the serum at the end of 3 weeks on the experimental diet. 4. Laying characteristics returned to normal 4 weeks after withdrawal of roxarsone. The liver weight, fat and TG in the liver and serum concentrations of TG, NEFA, high density lipoprotein (HDL) and AST increased significantly (P<0.05), while the level of very low density lipoprotein (VLDL) decreased (P<0.05) at the end of the withdrawal period. More prominent vacuolised hepatic fatty cells were observed in laying ducks treated with 300 mg/kg of roxarsone.