Anus preservation in low rectal adenocarcinoma based on MMR/MSI status (APRAM): a study protocol for a randomised, controlled, open-label, multicentre phase III trial

BACKGROUND

Anus preservation has been a challenge in the treatment of patients with low rectal adenocarcinoma (within 5 cm from the anal verge) because it is difficult to spare the anus with its functioning sphincter complex under the safe margin of tumour resection. Patients with dMMR/MSI-H can achieve a favourable complete response (CR) rate by using a single immune checkpoint inhibitor. For patients with pMMR/MSS/MSI-L, intensified neoadjuvant three-drug chemotherapy may be the preferred option for anal preservation. In addition, the watch and wait (W&W) strategy has been proven safe and feasible for patients with rectal cancer who achieve a clinical complete response (cCR). Therefore, we initiated this clinical trial to explore the optimal neoadjuvant treatment pattern for patients with low locally advanced rectal cancer (LARC) with different MMR/MSI statuses, aiming to achieve a higher cCR rate with the W&W strategy and ultimately provide more patients with a chance of anus preservation.

METHODS

This is a randomised, controlled, open-label, multicentre phase III trial. Patients with clinical stage T2-4 and/or N + tumours located within 5 cm from the anal verge are considered eligible. Based on the results of pathological biopsy, the patients are divided into two groups: dMMR/MSI-H and pMMR/MSS. Patients in the dMMR/MSI-H group will be randomly allocated in a 1:1 ratio to either arm A (monoimmunotherapy) or arm B (short-course radiotherapy followed by monoimmunotherapy). Patients in the pMMR/MSS group will be initially treated with long-term pelvic radiation with concurrent capecitabine combined with irinotecan. Two weeks after the completion of chemoradiotherapy (CRT), the patients will be randomly allocated in a 1:1 ratio to arm C (XELIRI six cycle regime) or arm D (FOLFIRINOX nine cycle regime). The irinotecan dose will be adjusted according to the UGT1A1-genotype. After treatment, a comprehensive assessment will be performed to determine whether a cCR has been achieved. If achieved, the W&W strategy will be adopted; otherwise, total mesorectal excision (TME) will be performed. The primary endpoint is cCR with the maintenance of 12 months at least, determined using digital rectal examination, endoscopy, and rectal MRI or PET/CT as a supplementary method.

DISCUSSION

APRAM will explore the best anus preservation model for low LARC, combining the strategies of consolidation chemotherapy, immunotherapy, and short-course radiotherapy, and aims to preserve the anus of more patients using W&W. Our study provides an accurate individual treatment mode based on the MMR/MSI status for patients with low LARC, and more patients will receive the opportunity for anus preservation under our therapeutic strategy, which would transform into long-term benefits.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05669092 (Registered 28th Nov 2022).

[A dry-reagent assay to rapidly detect Mycobacterium tuberculosis using loop-mediated isothermal amplification]

A molecular diagnostic assay which could be stored at room temperature was developed to rapidly detect Mycobacterium tuberculosis (MTB) based on loop-mediated isothermal amplification (LAMP) technology and dry-reagent process. LAMP uses 4 or 6 primers and Bst DNA polymerase to amplify DNA at a constant temperature. The results showed that the LAMP assay could detect the amplification of IS6110 target gene within 20 min using real-time fluorescence signal detection. The sensitive of LAMP assay was similar to the PCR technology while the precision of PCR was better than LAMP (coefficient of variation, LAMP 18.9%, PCR 3.4%), meaning LAMP was more suitable for qualitative detection. The LAMP assay did not amplify DNA of other 10 types of pathogens, including Neisseria meningitidis, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, Rubivirus, mumps virus, adenovirus (type 3), adenovirus (type 7), respiratory syncytial virus B and parainfluenza virus type 2, indicating a good specificity. Furthermore, a dry-reagent assay was developed using air-drying and freeze-drying process. The performance of dried reagents did not change after 10 days storage at 50 ℃, meaning the dried reagents could be stored at room temperature (25 ℃) for more than six months. The dry-reagent LAMP assay also successfully amplified MTB DNA from several clinical samples within 20 min. In conclusion, the developed LAMP assay together with isothermal amplifier could rapidly detection MTB.

Unraveling Colorectal Cancer and Pan-cancer Immune Heterogeneity and Synthetic Therapy Response Using Cuproptosis and Hypoxia Regulators by Multi-omic Analysis and Experimental Validation

Cuproptosis, a new type of programmed cell death (PCD), is closely related to cellular tricarboxylic acid cycle and cellular respiration, while hypoxia can modulate PCD. However, their combined contribution to tumor subtyping remains unexplored. Here, we applied a multi-omics approach to classify TCGA_COADREAD based on cuproptosis and hypoxia. The classification was validated in three colorectal cancer (CRC) cohorts and extended to a pan-cancer analysis. The results demonstrated that pan-cancers, including CRC, could be divided into three distinct subgroups (cuproptosis-hypoxia subtypes, CHSs): CHS1 had active metabolism and poor immune infiltration but low fibrosis; CHS3 had contrasting characteristics with CHS1; CHS2 was intermediate. CHS1 may respond well to cuproptosis inducers, and CHS3 may benefit from a combination of immunotherapy and anti-fibrosis/anti-hypoxia therapies. In CRC, the CHSs also showed a significant difference in prognosis and sensitivity to classic drugs. Organoid-based drug sensitivity assays validated the results of transcriptomics. Cell-based assays indicated that masitinib and simvastatin had specific effects on CHS1 and CHS3, respectively. A user-friendly website based on the classifier was developed (https://fan-app.shinyapps.io/chs_classifier/) for accessibility. Overall, the classifier based on cuproptosis and hypoxia was applicable to most pan-cancers and could aid in personalized cancer therapy.

Serum lncRNA-UFC1 as a potential biomarker for diagnosis and prognosis of pancreatic cancer

Early diagnosis is important to improve the prognosis of pancreatic cancer (PC). Identifying potential biomarkers is essential for the monitoring and treatment of PC. The long noncoding RNA (lncRNA) UFC1 has been identified as an oncogenic factor in many cancers. However, the expression of UFC1 and its potential role in diagnosis and prognosis of PC remain largely unknown. The present study aimed to investigate the role of serum UFC1 in diagnosis and prognosis. The results indicated that serum UFC1 expression was relatively higher in PC patients than that in healthy volunteers. ROC curve analysis revealed that the serum UFC1 levels could distinguish PC patients from healthy controls, with an AUC value of 0.810. In addition, the serum UFC1 expression level was associated with lymph nodes metastasis, distant metastasis, and clinical stage. Kaplan-Meier analysis indicated that patients with high UFC1 expression exhibited shorter progression-free survival (PFS) and overall survival (OS) than those with low UFC1 expression. Multivariate analysis demonstrated that clinical stage and UFC1 expression level were significant, independent prognostic factors in PC patients. Our data demonstrate that serum UFC1 might serve as a potential biomarker for diagnosis and prognosis of PC.

[Frailty progress and related factors in the elderly living in community: a prospective study]

Objective: To investigate frailty progress status and related factors in the elderly living in communities. Methods: A cohort of elderly people aged 65 and over in Pingyi community of Dujiangyan, Sichuan province, was established. Face-to-face questionnaire survey was conducted by trained interviewers. The frailty status, cognitive function, nutrition status and other functions of the subjects surveyed were evaluated at baseline survey and during follow-up. The socio-demographic and clinical characteristics of the subjects surveyed were assessed at baseline survey. Binary logistic regressions were used to identify factors associated with frailty progress. Results: A total of 653 elderly people were surveyed in January 2014, and 507 elderly people were followed up while 146 elderly people terminated further follow-up in January 2017. The prevalence rates of frailty and pre-frailty at baseline survey were 11.2% (n=57) and 26.2% (n=133), respectively. After 3 years, 205 subjects (40.4%) surveyed experienced frailty progress, 276 (54.5%) remained to be in frailty state at baseline survey, and 26 (5.1%) had improvement. Disability (OR=8.27, 95%CI: 1.62-42.26), visual problem (OR=2.02, 95%CI: 1.27-3.22), cognitive impairment (OR=1.94, 95%CI: 1.08-3.48), poor self-rated health (OR=1.89, 95%CI: 1.07-3.31), chronic pain (OR=1.57, 95%CI: 1.03-2.40) and older age (OR=1.12, 95%CI: 1.08-1.17) were independently associated with the progress of frailty. In contract, overweight was a protective factor (OR=0.54, 95%CI: 0.34-0.85). Conclusions: Frailty is a dynamic syndrome affected by several socio-demographic factors and geriatric factors. The results of the study can be used in the prevention of frailty progress in the elderly in communities.

Antifungal activity of the bioactive substance from Bacillus atrophaeus strain HAB-5 and its toxicity assessment on Danio rerio

The prevalence of pathogen inhibitors bacteria has motivate the study for antimicrobial compounds. Bioactive fungicide have always received considerable attention. A bacterial isolated strain HAB-5 showed antifungal activity against plant fungi. Based on morphological, physiological, biochemical and 16SrDNA sequence analysis, the strain was identified to be a Bacillus atrophaeus. This strain possessed a broad spectrum antifungal activity against various plant pathogenic fungi. Extraction of antifungal substance was performed and the crude extract had potent antifungal ability and showed great potential for swelling and inhibiting spore germination. This antifungal displayed heat stability and active in a wide pH range 5.0-10.0. Moreover no reduction was found in its activity after enzyme treatment. The toxicity test was evaluated in Danio rerio. The acute toxicity test indicated that the 24, 48, 72, 96h LC₅₀ values of UMTLS to the zebrafish were 14.4, 13.8, 13.4, and 12.9%, respectively. Based on the results obtained in this study, antifungal substance was not toxic to zebra. Analyses of disease suppression showed that HAB-5 was effective to reduce the incidence of anthracnose symptoms on mango fruits, also prevent disease infection and protect tobacco seedling from Phytophtora nicotianae. The bioactive substance from Bacillus atrophaeus HAB-5 could be a candidate in the generation of new antifungal agents in crop.

Direct Growth of Al2O3 on Black Phosphorus by Plasma-Enhanced Atomic Layer Deposition

Growing high-quality and uniform dielectric on black phosphorus is challenging since it is easy to react with O₂ or H₂O in ambient. In this work, we have directly grown Al₂O₃ on BP using plasma-enhanced atomic layer deposition (PEALD). The surface roughness of BP with covered Al₂O₃ film can reduce significantly, which is due to the removal of oxidized bubble in BP surface by oxygen plasma. It was also found there is an interfacial layer of PO _x in between amorphous Al₂O₃ film and crystallized BP, which is verified by both X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements. By increasing temperature, the PO _x can be converted into fully oxidized P₂O₅.

[Modified Chevron osteotomy combined distal soft tissue reconstruction to treat high-grade bunionette deformity]

OBJECTIVE

To explore the surgical method of using the modified chevron osteotomy combined distal soft tissue reconstruction to treat high-grade bunionette deformity.

METHODS

From June 2013 to June 2015, the modified chevron osteotomy combined distal soft tissue reconstruction was used for surgical treatment of high-grade bunionette deformity in the Department of Hand and Foot Microsurgery in Xuzhou Central Hospital.Twenty-six patients with 28 feet high-grade bunionette deformity were hospitalized for treatment, with 3 male (3 feet) and 23 female (25 feet) cases, aged 22-73 (mean 47.1) years old.The average fourth-fifth intermetatarsal angle, lateral deviation of the fifth metatarsal angle and metatarsophalangeal-fifth angle were measured on the pre-and post- operative anterior to posterior weight-beating X rays of treated feet.The American Orthopaedic Foot and Ankle Society (AOFAS) Lesser Toe Metatarsophalangeal-Interphalangeal Scale was used to evaluate the post-operative outcomes.

RESULTS

All of 26 patients were followed, with a mean 15.7 months (range 8-25 months). Primarily healing of the wound was achieved in all cases.No postoperative infection and nonunion on the osteotomy site was found during the follow-up time.The fracture healing time was 6-15 (mean 12.2) weeks.All the patients had satisfactory appearance and sensory function without callosum and metastatic metatarsalgia at the final follow-up.The post-operative fourth-fifth intermetatarsal angle, lateral deviation of the fifth metatarsal angle and metatarsophalangeal-fifth angle were significantly lesser than the pre-operative at the 6th week after operation, respectively [(5.5±1.7)°, (2.1±0.8)°, (5.7±2.6)°vs (16.4±4.2)°, (6.0±2.2)°, (10.5±7.4)°; all P<0.01]. The post-operative AOFAS score was significantly greater than the pre-operative [(87.1±6.7) vs (62.3±9.8) points, P<0.001].

CONCLUSION

The modified chevron osteotomy combined distal soft tissue reconstruction is a safe and easy treatment option for the high-grade bunionette deformity and provides patient satisfaction results.

[Massive hemorrhage caused by fungal infections after donation-after-cardiac-death kidney transplantation: clinical features, prevention and treatment experience]

OBJECTIVE

To study the characteristics and prevention and treatment strategies of massive hemorrhage caused by fungal infections after donation-after-cardiac-death (DCD) kidney transplantation.

METHODS

A total of 91 cases of DCD kidney transplantation between August 25, 2013 and June 30, 2015 in Third Affiliated Hospital of Sun Yat-sen Univservity were retrospectively analyzed. The characteristics of and prevention and treatments strategies for postoperative massive hemorrhage caused by fungal infections were summarized.

RESULTS

Ninety-one cases of DCD kidney transplantation were divided into 2 groups based on regimens for preventing postoperative fungal infections: fluconazole prophylaxis group: a total of 26 cases of renal transplant before June 11, 2014 received fluconazole regimen, from postoperative day 0 to 2 weeks; micafungin prophylaxis group: a total of 65 cases of renal transplant after June 11, 2014 received micafungin regimen, also for 2 weeks from postoperative day 0. Two cases in fluconazole group developed postoperative massive hemorrhage. In case 1, the hemorrhage occurred at 2 weeks after transplantation. Graft nephrectomy was performed during surgical exploration for hemostasis, yet the massive hemorrhage relapsed 2 weeks later. Endoluminal exclusion of external iliac artery using endovascular covered stent-graft at the anastomosis site was performed and the massive bleeding was successfully stopped. The patient was restored to hemodialysis and waited for second kidney transplantation. Candia albicans was detected in the culture of blood and drainage liquid from incision. The other case of hemorrhage occurred at 3 weeks after transplantation. Graft nephrectomy plus endovascular exclusion using covered stent-graft were also performed to stop the massive bleeding. Massive fungal hyphae and spores were observed at the stump of renal graft artery under microscope. The patient received second kidney transplantation after 6 months successfully. No massive hemorrhage caused by fungal infections occurred in micafungin prophylaxis group.

CONCLUSIONS

Massive hemorrhage cased by fungal infections after DCD kidney transplantation is usually characterized by delayed and recurrent course, and may result in graft nephrectomy or even death of patients. Endovascular exclusion using covered stent can successfully stop bleeding and rescue life of patients. Two-week preemptive prophylaxis of fungal infections using micafungin can effectively prevent delayed fungal massive hemorrhage in DCD kidney transplantation.

Sirolimus-Based Immunosuppressive Regimens in Renal Transplantation: A Systemic Review

Sirolimus (SRL)-based immunosuppressive regimens have been used for preventing rejection after kidney transplantation. This review analyzes their merits and demerits compared with other conventional regimes from the aspects of acute rejection rate, graft function, as well as patient/graft survival rates. In general, SRL is mostly recommended to be used as conversion therapy from calcineurin inhibitor (CNI) after kidney transplantation in most studies. Minimization or withdrawal of cyclosporine A (CsA) could also be considered when it was combined with SRL. SRL can replace mycophenolate mofetil (MMF), and the CNI dose should be reduced appropriately in this setting. Quadruple maintenance regimens containing SRL need future study to clarify their superiority. De novo use of low-dose CNI combined with SRL has no apparent merits and thus is not recommended. De novo use of standard-dose CNI combined with SRL followed by maintenance, de novo use of CNI-free regimens, as well as SRL use in delayed graft function (DGF) patients who spare antibody induction and postpone CNI administration should also be avoided. SRL supports steroids withdrawal after kidney transplantation, and SRL combined with tacrolimus is recommended in this setting. Loading dose is recommended when initiating SRL treatment and its trough blood level should be routinely monitored.

Electrical level of defects in single-layer two-dimensional TiO2

The remarkable properties of graphene and transition metal dichalcogenides (TMDCs) have attracted increasing attention on two-dimensional materials, but the gate oxide, one of the key components of two-dimensional electronic devices, has rarely reported. We found the single-layer oxide can be used as the two dimensional gate oxide in 2D electronic structure, such as TiO2. However, the electrical performance is seriously influenced by the defects existing in the single-layer oxide. In this paper, a nondestructive and noncontact solution based on spectroscopic ellipsometry has been used to detect the defect states and energy level of single-layer TiO2 films. By fitting the Lorentz oscillator model, the results indicate the exact position of defect energy levels depends on the estimated band gap and the charge state of the point defects of TiO2.

IGF-1 from adipose-derived mesenchymal stem cells promotes radioresistance of breast cancer cells

PURPOSE

The aim of this study was to investigate effects of adipose-derived mesenchymal stem cells (AMSCs) on radioresistance of breast cancer cells.

MATERIALS AND METHODS

MTT assays were used to detect any influence of AMSC supernatants on proliferation of breast cancer cells; cell migration assays were used to determine the effect of breast cancer cells on the recruitment of AMSCs; the cell survival fraction post-irradiation was assessed by clonogenic survival assay; γ-H2AX foci number post-irradiation was determined via fluorescence microscopy; and expression of IGF-1R was detected by Western blotting.

RESULTS

AMSC supernatants promoted proliferation and radioresistance of breast cancer cells. Breast cancer cells could recruit AMSCs, especially after irradiation. IGF-1 derived from AMSCs might be responsible for the radioresistance of breast cancer cells.

CONCLUSIONS

Our results suggest that AMSCs in the tumor microenvironment may affect the outcome of radiotherapy for breast cancer in vitro.

Meta-analysis of outcomes compared between robotic and laparoscopic gastrectomy for gastric cancer

This meta-analysis was performed to evaluate and compare the outcomes of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for treating gastric cancer. A systematic literature search was carried out using the PubMed database, Web of Knowledge, and the Cochrane Library database to obtain comparative studies assessing the safety and efficiency between RG and LG in May, 2013. Data of interest were analyzed by using of Review Manager version 5.2 software (Cochrane Collaboration). A fixed effects model or random effects model was applied according to heterogeneity. Seven papers reporting results that compared robotic gastrectomy with laparoscopic gastrectomy for gastric cancer were selected for this meta-analysis. Our meta- analysis included 2,235 patients with gastric cancer, of which 1,473 had undergone laparoscopic gastrectomy, and 762 had received robotic gastrectomy. Compared with laparoscopic gastrectomy, robotic gastrectomy was associated with longer operative time but less blood loss. There were no significant difference in terms of hospital stay, total postoperative complication rate, proximal margin, distal margin, numbers of harvested lymph nodes and mortality rate between robotic gastrectomy and laparoscopic gastrectomy. Our meta-analysis showed that robotic gastrectomy is a safe technique for treating gastric cancer that compares favorably with laparoscopic gastrectomy in short term outcomes. However, the long term outcomes between the two techniques need to be further examined.

[Effect of shRNAmir lentiviral vector-mediated COX-2 silencing on the radiosensitivity of nasopharyngeal carcinoma cells]

OBJECTIVE

To evaluate the effect of COX-2 silencing on the radiosensitivity of a nasopharyngeal carcinoma (NPC) cell line C666-1.

METHODS

Anti-COX-2 C666-1 cell line with COX-2 gene silencing mediated by shRNAmir lentiviral vector and the control cell line Anti-GL-2 C666-1 were exposed to various radiation doses. The clonogenic survival assay and curve fitting was used to calculate the radiobiological parameters and the sensitization enhancement ratio after the radiation. Cell cycle changes were assessed after the exposure by flow cytometric analysis. In a BALB/c nude mouse model, the growth curve of the xenografts was generated and the tumor growth inhibition rate was calculated.

RESULTS

Compared with the control cells, Anti-COX-2 C666-1 cells showed obviously lowered values of SF2, D0 and Dq but significantly increased α/β with a sensitivity enhancement ratio of 1.4014. COX-2 gene silencing increased the inhibition rate of the tumor xenografts after the radiation, and caused also decreased percentage of G2/M arrest resulting from the exposure.

CONCLUSION

Stable COX-2 silencing in NPC cells can improve the effect of radiotherapy both in vitro and in vivo. By changing the radiobiological parameters, genetically based COX-2 inhibitor may be a potentially promising radiosensitizer of NPC.

Neuropeptide Y receptors differentially modulate G-protein-activated inwardly rectifying K+ channels and high-voltage-activated Ca2+ channels in rat thalamic neurons

1. Using whole-cell patch-clamp recordings, infrared videomicroscopy and fast focal solution exchange methods, the actions of neuropeptide Y (NPY) were examined in thalamic slices of postnatal (10-16 days) rats. 2. NPY activated a K+-selective current in neurons of the thalamic reticular nucleus (RT; 20/29 neurons) and ventral basal complex (VB; 19/25 neurons). The currents in both nuclei had activation and deactivation kinetics that were very similar to those of GABAB receptor-induced currents, were totally blocked by 0.1 mM Ba2+ and showed voltage-dependent relaxation. These properties indicate that the NPY-sensitive K+ current is mediated by G-protein-activated, inwardly rectifying K+ (GIRK) channels. 3. In RT neurons, NPY application reversibly reduced high-voltage-activated (HVA) currents to 33 +/- 5 % (n = 40) of the control level but did not affect the T-type currents. Inhibition of Ca2+ currents was voltage independent and was largely mediated by effects on N- and P/Q-type channels. 4. NPY activation of GIRK channels was mediated via NPY1 receptors, whereas inhibition of N- and P/Q-type Ca2+ channels was mediated by NPY2 receptors. 5. These results show that neuropeptide Y activates K+ channels and simultaneously inhibits HVA Ca2+ channels via different receptor subtypes.

Differential regulation of GABA release and neuronal excitability mediated by neuropeptide Y1 and Y2 receptors in rat thalamic neurons

1. Neuropeptide Y (NPY) produced inhibitory effects on neurons of the thalamic reticular nucleus (RT; n = 18) and adjacent ventral basal complex (VB; n = 22), which included hyperpolarization (approximately 4 mV), a reduction in rebound and regular spikes and an increased membrane conductance. These effects were mediated predominantly via NPY1 receptor activation of G-protein-activated, inwardly rectifying K+ (GIRK) channels. 2. NPY reduced the frequency of spontaneous GABAA receptor-mediated inhibitory postsynaptic currents (sIPSCs) in RT (by 60 +/- 7 %, n = 14) and VB neurons (by 25 +/- 11 %, n = 16), but had no effect on the kinetic properties of sIPSCs. After removal of the RT nucleus, the inhibitory effects of NPY on sIPSCs in VB neurons remained (29 +/- 7 %, n = 5). The synaptic effects were mediated via NPY2 receptors. 3. NPY inhibited the frequency of miniature IPSCs (mIPSCs) in RT and VB neurons (by 63 +/- 7 %, n = 5, and 37 +/- 8 %, n = 10, respectively) in the presence of tetrodotoxin (TTX) (1 microM) but not TTX (1 microM) and Cd2+ (200 microM). 4. NPY inhibited evoked IPSCs in both RT (by 18 +/- 3 %, n = 6) and VB (by 5 +/- 4 %, n = 6) neurons without change in short-term synaptic plasticity. 5. We conclude that NPY1 and NPY2 receptors are functionally segregated in the thalamus: NPY1 receptors are predominantly expressed at the somata and dendrites and directly reduce the excitability of neurons in both the RT and VB nuclei by activating GIRK channels. NPY2 receptors are located at recurrent (RT) and feed-forward GABAergic terminals (VB) and downregulate GABA release via inhibition of Ca2+ influx from voltage-gated Ca2+ channels.

Huperzine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students

AIM

To study the efficacy of huperzine-A capsules (Hup) on memory and learning performance of adolescent students.

METHODS

Using double-blind and matched pair method, 34 pairs of junior middle school students complaining of memory inadequacy were divided into two groups by normal psychological health inventory (PHI), similar memory quotient (MQ), same sex and class. The Hup group was administrated orally 2 capsules of Hup (each contains Hup 50 micrograms) b.i.d., and the placebo group was given 2 capsules of placebo (starch and lactose inside) b.i.d. for 4 wk.

RESULTS

At the end of trial, the Hup group's MQ (115 +/- 6) was more than that of the placebo group (104 +/- 9, P < 0.01), and the scores of Chinese language lesson in the Hup group were elevated markedly too.

CONCLUSION

The Hup capsules enhance the memory and learning performance of adolescent students.

G-proteins are involved in 5-HT receptor-mediated modulation of N- and P/Q- but not T-type Ca2+ channels

5-HT produces voltage-independent inhibition of the N-, P/Q-, and T-type Ca2+ currents in sensory neurons of Xenopus larvae by acting on 5-HT1A and 5-HT1D receptors. We have explored the underlying mechanisms further and found that the inhibition of high voltage-activated (HVA) currents by 5-HT is mediated by a pertussis toxin-sensitive G-protein that activates a diffusible second messenger. Although modulation of T-type currents is membrane-delimited, it was not affected by GDP-beta-S (2 mM), GTP-gamma-S (200 microM), 5'-guanylyl-imidodiphosphate tetralithium (200 microM), aluminum fluoride (AlF4-, 100 microM), or pertussis toxin, suggesting that a GTP-insensitive pathway was involved. To investigate the modulation of the T currents further, we synthesized peptides that were derived from conserved cytoplasmic regions of the rat 5-HT1A and 5-HT1D receptors. Although two peptides derived from the third cytoplasmic loop inhibited the HVA currents by activating G-proteins and occluded the modulation of HVA currents by 5-HT, two peptides from the second cytoplasmic loop and the C tail had no effect. None of the four receptor-derived peptides had any effect on the T-type currents. We conclude that 5-HT modulates T-type channels by a membrane-delimited pathway that does not involve G-proteins and is mediated by a functional domain of the receptor that is distinct from that which couples to G-proteins.

Differential inhibition of N and P/Q Ca2+ currents by 5-HT1A and 5-HT1D receptors in spinal neurons of Xenopus larvae

1. In whole-cell patch clamp recordings made from non-sensory neurons acutely isolated from the spinal cord of Xenopus (stage 40-42) larvae, two forms of inhibition of the high voltage-activated (HVA) Ca2+ currents were produced by 5-HT. One was voltage dependent and associated with both slowing of the activation kinetics and shifting of the voltage dependence of the HVA currents. This inhibition was relieved by strong depolarizing prepulses. A second form of inhibition was neither associated with slowing of the activation kinetics nor relieved by depolarizing prepulses and was thus voltage independent. 2. In all neurons examined, 5-HT (1 microM) reversibly reduced 34 +/- 1.6 % (n = 102) of the HVA Ca2+ currents. In about 40 % of neurons, the inhibition was totally voltage independent. In another 5 %, the inhibition was totally voltage dependent. In the remaining neurons, inhibition was only partially (by around 40 %) relieved by a large depolarizing prepulse, suggesting that in these, the inhibition consisted of both voltage-dependent and -independent components. 3. By using selective channel blockers, we found that 5-HT acted on both N- and P/Q-type channels. However, whereas the inhibition of P/Q-type currents was only voltage independent, the inhibition of N-type currents had both voltage-dependent and -independent components. 4. The effects of 5-HT on HVA Ca2+ currents were mediated by 5-HT1A and 5-HT1D receptors. The 5-HT1A receptors not only preferentially caused voltage-independent inhibition, but did so by acting mainly on the omega-agatoxin-IVA-sensitive Ca2+ channels. In contrast, the 5-HT1D receptor produced both voltage-dependent and -independent inhibition and was preferentially coupled to omega-conotoxin-GVIA sensitive channels. This complexity of modulation may allow fine tuning of transmitter release and calcium signalling in the spinal circuitry of Xenopus larvae.

Serotonergic inhibition of the T-type and high voltage-activated Ca2+ currents in the primary sensory neurons of Xenopus larvae

The primary sensory Rohon-Beard (R-B) neurons of Xenopus larvae are highly analogous to the C fibers of the mammalian pain pathway. We explored the actions of 5-HT by studying the modulation of Ca2+ currents. In approximately 80% of the acutely isolated R-B neurons, 5-HT inhibited the high voltage-activated (HVA) currents by 16% (n = 29) and the T-type currents by 24% (n = 41). The modulation of the T-type and the HVA currents was mimicked by selective 5-HT1A and 5-HT1D agonists: 8-OH-DPAT and L-694,247. The effects of the agonists were blocked by their respective 5-HT1A or 5-HT1D antagonists: p-MPPI and GR127935, suggesting that both 5-HT1A and 5-HT1D receptors were involved. Approximately 70% of the actions of 5-HT on HVA currents was occluded by omega-conotoxin-GVIA (N-type channel blocker), whereas the rest of the modulation ( approximately 30%) was occluded by <100 nM omega-agatoxin-TK (P/Q-type channel blocker). This suggests that 5-HT acts on N- and P/Q-type Ca2+ channels. Neither the modulation of the T-type nor that of the HVA currents was accompanied by changes in their voltage-dependent kinetics. Cell-attached patch-clamp recordings suggest that the modulation of the T-type channel occurs through a membrane-delimited second messenger. We have studied the functional consequences of the modulation of T-type Ca2+ channels and have found that these channels play a role in spike initiation in R-B neurons. Modulation of T-type channels by 5-HT therefore could modulate the sensitivity of this sensory pathway by increasing the thresholds of R-B neurons. This is a new and potentially important locus for modulation of sensory pathways in vertebrates.