Satisfactory Usage of a Lacerated Kidney for Transplantation: A Case Report

BACKGROUND

Organ shortage is the main bottleneck in the wait-list for transplantation; therefore, expanding the donor pool is an effective way to solve the problem. Usage of the traumatized liver for transplantation has been applied, but the use of lacerated kidneys for transplant donor is rarely reported.

METHODS

We reported a successful case of donation after brain death. The donor committed suicide by jumping from a campus dormitory building. One of the donated kidneys was severely injured. Two lacerations measured 4 × 1 × 1 cm in the medial margin of the graft and 1 × 1 × 1.5 cm in the front side of the graft, respectively. After repair with continuous absorbable suture, the lacerated kidney was transplanted to a recipient.

RESULTS

The post-transplantation renal function gradually recovered. Furthermore, serious complications, such as large amounts of hemorrhage, delayed graft function, or urinary fistula did not occur. The serum creatinine dropped from 1232 μmol/L to 120 μmol/L and maintained normal range after surgery. In addition, the daily urine output was normal. At day 12 after operation, the patient was discharged.

CONCLUSIONS

Our case shows that the use of a lacerated donor kidney appears to be feasible, but long-term effects need further observation.

Discovery of a BTK/MNK dual inhibitor for lymphoma and leukemia

Bruton's tyrosine kinase (BTK) kinase is a member of the TEC kinase family and is a key regulator of the B-cell receptor (BCR)-mediated signaling pathway. It is important for B-cell maturation, proliferation, survival and metastasis. Pharmacological inhibition of BTK is clinically effective against a variety of B-cell malignances, such as mantle cell lymphoma, chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML) and activated B-cell-diffuse large B-cell lymphoma. MNK kinase is one of the key downstream regulators in the RAF-MEK-ERK signaling pathway and controls protein synthesis via regulating the activity of eIF4E. Inhibition of MNK activity has been observed to moderately inhibit the proliferation of AML cells. Through a structure-based drug-design approach, we have discovered a selective and potent BTK/MNK dual kinase inhibitor (QL-X-138), which exhibits covalent binding to BTK and noncovalent binding to MNK. Compared with the BTK kinase inhibitor (PCI-32765) and the MNK kinase inhibitor (cercosporamide), QL-X-138 enhanced the antiproliferative efficacies in vitro against a variety of B-cell cancer cell lines, as well as AML and CLL primary patient cells, which respond moderately to BTK inhibitor in vitro. The agent can effectively arrest the growth of lymphoma and leukemia cells at the G0-G1 stage and can induce strong apoptotic cell death. These primary results demonstrate that simultaneous inhibition of BTK and MNK kinase activity might be a new therapeutic strategy for B-cell malignances.

Correlation of genetic polymorphism of vascular endothelial growth factor gene with susceptibility to lung cancer

The aim of the study is to study the correlation of genetic polymorphism of vascular endothelial growth factor (VEGF) gene with susceptibility to primary lung cancer. A total of 414 patients with primary lung cancer and 338 healthy volunteers were enrolled in this case-control study from September 2008 to October 2011. Gene identification with PCR-RFLP (polymerase chain reaction-based restriction fragment length polymorphism) was used to detect in white blood cells from the subjects the single-nucleotide polymorphisms (SNP) of VEGF gene, including +405G/C, -460 T/C, -1154G/A, -2578C/A sites. Association of genotypes or haplotypes with susceptibility of lung cancer was analyzed with unconditional logistic regression adjusted by gender and age. Smoking was significantly associated with increased risk of lung cancer. Gene phenotypic analysis demonstrated that C allele of +405G/C in VEGF gene was significantly associated increased risk of lung cancer in males (P=0.0094, odds ratio=1.634.3), as that with carrying GCTC haplotype (odds ratio=1.349), whereas carrying GACG had decreased risk for lung cancer (odds ratio=0.044). No relationship existed between 460 T/C, -1154G/A, -2578C/A alleles of VEGF gene and risk of lung cancer. VEGF gene polymorphism may have a role in the development of lung cancer.

Combinations of bacterial species associated with symptomatic endodontic infections in a Chinese population

AIM

To use microarrays to detect 11 selected bacteria in infected root canals, revealing bacterial combinations that are associated with clinical symptoms and signs of primary endodontic infections in a Chinese population.

METHODOLOGY

DNA was extracted from 90 samples collected from the root canals of teeth with primary endodontic infections in a Chinese population, and the 16S rRNA gene was amplified by polymerase chain reaction (PCR). The PCR products were hybridized to microarrays containing specific oligonucleotide probes targeting 11 species, and the arrays were screened with a confocal laser scanner. Pearson's chi-squared test and cluster analysis were performed to investigate the associations between the bacterial combinations and clinical symptoms and signs using SAS 8.02.

RESULTS

Seventy-seven samples (86%) yielded at least one of the 11 target species. Parvimonas micra (56%), Porphyromonas endodontalis (51%), Tannerella forsythia (48%), Prevotella intermedia (44%) and Porphyromonas gingivalis (37%) were the most prevalent taxa and were often concomitant. The following positive associations were found between the bacterial combinations and clinical features: P. endodontalis and T. forsythia with abscess; P. gingivalis and P. micra with sinus tract; P. gingivalis and P. endodontalis or P. micra and P. endodontalis with abscess and sinus tract; and the combination of P. endodontalis, P. micra, T. forsythia and P. gingivalis with sinus tract (P < 0.05).

CONCLUSIONS

Various combinations of P. micra, P. endodontalis, T. forsythia and P. gingivalis may contribute to abscesses or sinus tracts of endodontic origin with bacterial synergism in a Chinese population.

Rare case of concurrent severe chylous ascites after radical surgery for cervical cancer

BACKGROUND

Cervical cancer case supervened with chylous ascites after extensive hysterectomy is rarely reported, and is very difficult to deal with.

CASE

A 40-year-old female patient complained of a small amount of vaginal bleeding after intercourse over the past seven years, and then was diagnosed as cervical squamous cell carcinoma IIa, with moderate anemia and leucopenia. The patient underwent radiotherapy and was given leucogen and iron dextran to elevate blood leukocyte at the same time. Considering blood routine examination was normal, the patient underwent extensive hysterectomy, bilateral adenectomy, and pelvic lymphadenectomy. By day 30 postoperatively, chyluria test showed positive which indicated chylous ascites in the patient. Since then, the patient successively had hypoproteinemia, electrolyte imbalance, high fever, fungal infection, etc. Very fortunately, the patient made a remarkable recovery from the serious condition after a series of flexible anti-infection and effective supportive treatments.

CONCLUSION

Chylous ascites leads to the loss of lipid, plasma protein, fat-soluble vitamins, and subsequently malnutrition. Firstly, the primary disease should be dealt with through chemotherapy or radiotherapy for malignant tumors. Anti-infective therapy can prevent intra-abdominal infections and the occurrence of bacteremia. Considering postoperative treatments last longer in this case, the authors changed antibiotics several times to avoid drug resistance. However, the patient unfortunately had complication of fungal septicemia due to the serious condition, which should to be avoided next time. In addition, the balance of water, electrolyte, and acid-base is particularly important in the overall treatment.

The FUS1 gene inhibits EC109 cell growth mediated by a lentivirus vector

The effects of the FUS1 gene on the oesophageal carcinoma cell line EC109 are investigated. The messenger RNA (mRNA) expression level of the FUS1 gene was detected by a reverse transcription polymerase chain reaction (RT-PCR) technique in the cell lines SHEE, SHEEC and EC109. The full length of the FUS1 gene was amplified using a PCR technique from the total RNA of umbilical mesenchymal stem cells. The FUS1 gene was cloned into a pSL6-IRES-EGFP vector and identified by PCR, digestion and sequencing. The recombinant pSL6-FUS1-IRES-EGFP plasmid was transfected into 293FT cells and the resulting lentivirus was collected. The growth of EC109 cells after transfection with lentivirus containing the FUS1 gene was determined by MTT assay and plate colony formation. Expression of the FUS1 gene in EC109 cells was weaker than that in SHEE, SHEEC cells and human umbilical vein endothelial cells (HUVEE; used as a control). Transfection efficiency was more than 80% after 48 h. Cell growth assessed by MTT assay was inhibited by about 40% compared with the control group; a finding that was in accordance with the plate colony formation results. The results suggest that the FUS1 gene might be a candidate tumour suppressor gene for the treatment of oesophageal carcinoma; however, these results require confirmation in in vivo studies.

The neurochemical mobile with non-linear interaction matrix: an exploratory computational model

Several years ago, the "neurochemical mobile" was introduced as a visual tool for explaining the different balances between neurotransmitters in the brain and their role in mental disorders. Here we complement this concept with a non-linear computational systems model representing the direct and indirect interactions between neurotransmitters, as they have been described in the "neurochemical interaction matrix." The model is constructed within the framework of biochemical systems theory, which facilitates the mapping of numerically ill-characterized systems into a mathematical and computational construct that permits a variety of analyses. Simulations show how short- and long-term perturbations in any of the neurotransmitters migrate through the entire system, thereby affecting the balances within the mobile. In cases of short-term alterations, transients are of particular interest, whereas long-term changes shed light on persistently altered, allostatic states, which in mental diseases and sleep disorders could be due to a combination of unfavorable factors, resulting from a specific genetic predisposition, epigenetic effects, disease, or the repeated use of drugs, such as opioids and amphetamines.

Human papillomavirus (HPV) infection and the risk of esophageal squamous cell carcinoma

There is currently no consensus on the relationship between human papillomavirus (HPV) infection and the pathogenic process of esophageal squamous cell carcinoma (ESCC). Therefore, a retrospective study was performed to explore the association between HPV infection and ESCC, where 225 patients with diagnosed ESCC and 224 matched controls were enrolled in the study and stratified according to smoking and alcohol consumption. Enzyme-linked immunosorbent assay was used to determine seropositivity to HPV by the detection of either IgG or IgM anti-HPV antibodies. In the non-smoking and non-alcohol-consuming subgroup, the incidence of ESCC of HPV seropositive subjects was similar with that of HPV seronegative subjects (P= 0.737, odds ratio [OR] 1.14, 95% confidence interval [CI] 0.54-2.40). However, in the smoking subgroup, there was a significant difference in the incidence of ESCC between HPV seropositive subjects and HPV seronegative subjects (P= 0.009, OR 2.22, 95% CI 1.22-4.04). In addition, there was a significantly higher association of the development of ESCC in HPV seropositive patients that smoke and drink than those that do not (P < 0.001, OR 10.31, 95% CI 4.04-26.29). Therefore, HPV infection is not an independent risk factor for developing ESCC in the non-smoking and non-alcohol-consuming group. For smokers, however, HPV infection increases the risk of the incidence of ESCC.

Endometrial cancer metastasize to the skin of lower leg and vagina: case report and literature review

Endometrial cancer is the most frequent malignancy of the female reproductive system, while cutaneous metastasis is extremely rare in endometrial cancer. The authors herein report a case ofendometrial adenocarcinoma (FIGO Stage IIIC2, Grade 2) with metastasis to the skin of right lower leg and vaginal orifice. The patient was treated with local excision and combination chemotherapy, but she did not respond to therapy and died within 11 months. The authors reviewed the clinico-pathologic features, treatment, and prognosis of such case with cutaneous metastasis.

Copy number variation in pediatric multiple sclerosis

BACKGROUND

Pediatric onset multiple sclerosis (MS) accounts for 2-4% of all MS. It is unknown whether the disease shares the same underlying pathophysiology found in adult patients or an extreme early onset phenotype triggered by distinct biological mechanisms. It has been hypothesized that copy number variations (CNVs) may result in extreme early onset diseases because CNVs can have major effects on many genes in large genomic regions.

OBJECTIVES AND METHODS

The objective of the current research was to identify CNVs, with a specific focus on de novo CNVs, potentially causing early onset MS by competitively hybridizing 30 white non-Hispanic pediatric MS patients with each of their parents via comparative genomic hybridization (CGH) analysis on the Agilent 1M CGH array.

RESULTS AND DISCUSSION

We identified 10 CNVs not overlapping with any CNV regions currently reported in the Database of Genomic Variants (DGV). Fifty-five putatively de novo CNVs were also identified: all but one common in the DGV. We found the single rare CNV was a private variation harboring the SACS gene. SACS mutations cause autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) disease. Additional clinical review revealed that the patient with the SACS gene CNV shared some features of both MS and ARSACS.

CONCLUSIONS

This is the first reported study analyzing pediatric MS CNVs. While not yielding causal variation in our initial pediatric dataset, our approach confirmed diagnosis of an ARSACS-like disease in addition to MS in the affected individual, which led to a more complete understanding of the patient's disease course and prognosis.

DJ-1 protects dopaminergic neurons against rotenone-induced apoptosis by enhancing ERK-dependent mitophagy

Loss-of-function mutations in the gene encoding the multifunctional protein, DJ-1, have been implicated in the pathogenesis of early-onset familial Parkinson's disease (PD), suggesting that DJ-1 may act as a neuroprotectant for dopaminergic (DA) neurons. Enhanced autophagy may benefit PD by clearing damaged organelles and protein aggregates; thus, we determined if DJ-1 protects DA neurons against mitochondrial dysfunction and oxidative stress through an autophagic pathway. Cultured DA cells (MN9D) overexpressing DJ-1 were treated with the mitochondrial complex I inhibitor, rotenone. In addition, rotenone was injected into the left substantia nigra of rats 4weeks after injection with a DJ-1 expression vector. Overexpression of DJ-1 protected MN9D cells against apoptosis, significantly enhanced the survival of nigral DA neurons after rotenone treatment in vivo, and rescued rat behavioral abnormalities. Overexpression of DJ-1 enhanced rotenone-evoked expression of the autophagic markers, beclin-1 and LC3II, while transmission electron microscopy and confocal imaging revealed that the ultrastructural signs of autophagy were increased by DJ-1. The neuroprotective effects of DJ-1 were blocked by phosphoinositol 3-kinase and the autophagy inhibitor, 3-methyladenine, and by the ERK pathway inhibitor, U0126. Confocal imaging revealed that the size of p62-positive puncta decreased significantly in DJ-1 overexpression of MN9D cells 12h after rotenone treatment, suggesting that DJ-1 reveals the ability to clear aggregated p62 associated with PD. Factors that control autophagy, including DJ-1, may inhibit rotenone-induced apoptosis and present novel targets for therapeutic intervention in PD.

SU-E-T-188: Evaluation of a 3D Patient Relevant Dose QA Tool: Multiple Institutional Studies

PURPOSE

To evaluate 3DVHTM as a patient dose-verification and analysis tool through multiple institutional studies. Virtual patient doses were measured and compared among different vendors' treatment planning systems (TPS) and delivered by different vendors' LINACS so that we better understand the uncertainty of entire process within a patient undergone radiotherapy.

METHODS

One head-and-neck (H&N) and one lung patient were selected in this study. The DICOM images/RT structures along with clinical protocols including prescription doses (59.4Gy for H&N and 70.2Gy for lung) and normal&hyphen;tissues tolerances were distributed to six institutions. Based on the same criteria, each institution generated their IMRT plans for the patients. Four different TPS and six different LINACS were used. The conventional per&hyphen;beam IMRT QA using MapCHECK was performed by all participants. All the measured and calculated data were sent back to one institution for 3DVH analysis. Through the use of planned-dose-perturbation (PDP)TM algorithm (Sun Nuclear Corp.), the 'actual-DVHs' were generated and then compared to the 'reference-DVHs' from plans. Their differences represented errors induced from the combination of TPS dose-calculation algorithm and beam-delivery systems.

RESULTS

All plans in the study have met the clinical criteria. The 3D matching rates for 3%global/3mm (DD/DTA) ranged from 95.8-99.9% for H&N and 93.5-100% for lung. The dose-difference-histogram for PTV had a mean of 0.67% [0-2%] for H&N cases and 1% [0.6-2.8%] for lung cases. The QA tool was able to spot the doses outside 3%/3mm criteria for critical structures much easier than conventional planar QA methods. In addition, the hot/cold spots at the boundaries of collimators are attributed to the uncertainty of collimator-positioning greater than 1-mm.

CONCLUSIONS

The analysis of IMRT plans in this study has shown that 3DVH is a vital QA tool for assessing clinically relevant doses as well as diagnosing potential systematic errors from both TPS and delivery systems.

Mesoscopic models of neurotransmission as intermediates between disease simulators and tools for discovering design principles

Two grand challenges have been declared as premier goals of computational systems biology. The first is the discovery of network motifs and design principles that help us understand and rationalize why biological systems are organized in the manner we encounter them rather than in a different fashion. The second goal is the development of computational models supporting the investigation of complex systems, in particular, as simulation platforms in personalized medicine and predictive health. Interestingly, most published systems models in biology contain between a handful and a few dozen variables. They are usually too complicated for systemic analyses of organizing principles, but they are at the same time too coarse to allow reliable simulations of diseases. While it may thus appear that the modeling efforts of the past have missed the declared targets of systems biology, we argue in this article that midsized mesoscopic models are excellent starting points for pursuing both goals in computational systems biology.

Baifuzi reduces transient ischemic brain damage through an interaction with the STREX domain of BKCa channels

Stroke is a long-term disability and one of the leading causes of death. However, no successful therapeutic intervention is available for the majority of stroke patients. In this study, we explored a traditional Chinese medicine Baifuzi (Typhonium giganteum Engl.). We show, at first, that the ethanol extract of Baifuzi exerts neuroprotective effects against brain damage induced by transient global or focal cerebral ischemia in rats and mice. Second, the extract activated large-conductance Ca(2+)-activated K(+) channel (BK(Ca)) channels, and BK(Ca) channel blockade suppressed the neuroprotection of the extract, suggesting that the BK(Ca) is the molecular target of Baifuzi. Third, Baifuzi cerebroside (Baifuzi-CB), purified from its ethanol extract, activated BK(Ca) channels in a manner similar to that of the extract. Fourth, the stress axis hormone-regulated exon (STREX) domain of the BK(Ca) channel directly interacted with Baifuzi-CB, and its deletion suppressed channel activation by Baifuzi-CB. These results indicate that Baifuzi-CB activated the BK(Ca) channel through its direct interaction with the STREX domain of the channel and suggests that Baifuzi-CB merits exploration as a potential therapeutic agent for treating brain ischemia.

Effects of dopamine and glutamate on synaptic plasticity: a computational modeling approach for drug abuse as comorbidity in mood disorders

Major depressive disorder (MDD) affects about 16% of the general population and is a leading cause of death in the United States and around the world. Aggravating the situation is the fact that "drug use disorders" are highly comorbid in MDD patients, and VICE VERSA. Drug use and MDD share a common component, the dopamine system, which is critical in many motivation and reward processes, as well as in the regulation of stress responses in MDD. A potentiating mechanism in drug use disorders appears to be synaptic plasticity, which is regulated by dopamine transmission. In this article, we describe a computational model of the synaptic plasticity of GABAergic medium spiny neurons in the nucleus accumbens, which is critical in the reward system. The model accounts for effects of both dopamine and glutamate transmission. Model simulations show that GABAergic medium spiny neurons tend to respond to dopamine stimuli with synaptic potentiation and to glutamate signals with synaptic depression. Concurrent dopamine and glutamate signals cause various types of synaptic plasticity, depending on input scenarios. Interestingly, the model shows that a single 0.5 mg/kg dose of amphetamine can cause synaptic potentiation for over 2 h, a phenomenon that makes synaptic plasticity of medium spiny neurons behave quasi as a bistable system. The model also identifies mechanisms that could potentially be critical to correcting modifications of synaptic plasticity caused by drugs in MDD patients. An example is the feedback loop between protein kinase A, phosphodiesterase, and the second messenger cAMP in the postsynapse. Since reward mechanisms activated by psychostimulants could be crucial in establishing addiction comorbidity in patients with MDD, this model might become an aid for identifying and targeting specific modules within the reward system and lead to a better understanding and potential treatment of comorbid drug use disorders in MDD.

Unacceptable side-effects associated with a hyperosmolar vaginal microbicide in a phase 1 trial

We carried out a phase 1 trial of a candidate vaginal microbicide gel against HIV-1 and other sexually transmitted diseases, which contained cellulose acetate 1,2-benzenedicarboxylate (also known as cellulose acetate phthalate) in a glycerol-based vehicle. We had to terminate the study after five women had completed dosing, due to all women experiencing unacceptable vulvo-vaginal side-effects. Further investigations showed that the gel had a very high osmolality, which we believe led to excessive fluid transudation across the vaginal mucosa and acute mucosal dysfunction. We also showed that the rheology of the gel changed dramatically on fluid dilution. The osmolality and rheology of candidate microbicides and other genital mucosal products should therefore be analysed and considered at an early stage of product development.

Monoclonal antibody treatment to prolong the secondary cardiac allograft survival in alloantigen-primed mice

We have previously shown that costimulation blockade using a combination of monoclonal antibodies (mAbs) - CTLA4Ig, antibodies to CD154, LFA-1, and OX40L - can induce tolerance of cardiac allografts in mice with adoptively transferred CD4(+) memory T cells [1]. However, the effect of costimulatory blockade in secondary allograft rejection has not been studied. B6 mice that rejected BALB/c skin grafts for more than 4 weeks (defined as alloantigen-primed mice) were used as recipients. The recipient mice were treated with the mAbs to CD154, LFA-1, OX40L, and CD122 on days 0, 2, 4, and 6 after the secondary transplantation of BALB/c heart. The mean survival time (MST) of secondary cardiac allografts in rats treated with antibodies to CD154 and LFA-1 (2-antibodies approach) and those treated with antibodies to CD154, LFA-1, OX40L, and CD122 (4-antibodies approach) was greater than that of the controls (MST = 6.7 days, 22.2 days, and 3.2 days, respectively). The 4-antibodies approach prevented lymphocytic infiltration in the grafts, inhibited memory T-cells proliferation in the spleen, increased IL-10 secretion in the serum, and enhanced the expression of CD4(+) Foxp3(+) regulatory T cells (Tregs) in spleen. Expression levels of alloreactive antibodies were high in the recipient mice of experimental and control groups. Inhibiting the memory T cells by costimulation blockade extended allograft survival in secondary transplant models but could not induce tolerance of graft. Alloreactive antibodies may participate in alloresponse and play an important role in secondary cardiac allograft rejection.

Novel sulfated glucomannan-barium-alginate microcapsules in islet transplantation: significantly decreased the secretion of monocyte chemotactic protein 1 and improved the activity of islet in rats

The sulfated glucomannan can be used to filter the heparin-binding properties of cytokines. In this study, novel sulfated glucomannan-barium-alginate (SGA) microcapsules were prepared to encapsulate islets with barium-alginate (ABa) and calcium alginate-poly-l-lysine (APA) microcapsules as controls. SD rat islets were purified as donor cells to Lewis rats that had been treated with streptozotocin. Intraperitoneal transplantation was performed with about 3000 islet equivalent (IEQ) rat. At week three after transplantation, the concentrations of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-1 beta, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha in intraperitoneal fluid were determined using ELISA. At week 8, the islet cell mass in the abdominal microcapsules was excised to test insulin release. The EB-FDA fluorescence staining method was used to observe the functional activity of the islet cells. Compared with ABa and APA microcapsules, SGA microcapsules showed significantly decreased MCP-1 secretion by beta-cells. Also, the concentrations of cytokines IL-1beta, IFN-gamma, and TNF-alpha were decreased significantly. The activity of the transplanted islets was significantly improved in SGA microcapsules, which shielded against cytokines better than ABa or APA microcapsules and may serve as novel method.

Hypericin prolongs action potential duration in hippocampal neurons by acting on K+ channels

BACKGROUND AND PURPOSE

Synaptic deficiency is generally accepted to be involved in major depression, and accordingly classic antidepressants exert their effects through enhancing synaptic efficiency. Hypericin is one of the major active constituents of extracts of St. John's Wort (Hypericum perforatum L.) with antidepressive actions, but little is known about its therapeutic mechanisms. Our aim was to explore whether hypericin has a modulatory effect on neuronal action potential (AP) duration by acting on voltage-gated ion channels.

EXPERIMENTAL APPROACH

We used voltage-clamp and current-clamp techniques in a whole-cell configuration to study primary cultures of neonatal rat hippocampal neurones. We measured the effects of extracellularly applied hypericin on AP duration as well as on voltage-gated Na(+), I(A) and I(K) currents.

KEY RESULTS

Extracellularly applied hypericin dose-dependently increased AP duration but barely affected its amplitude. Further analysis revealed that hypericin inhibited both transient I(A) and delayed rectifier I(K) potassium currents. In contrast, hypericin exerted no significant effect on both Na(+) peak current and its decay kinetics.

CONCLUSIONS AND IMPLICATIONS

Extracellularly applied hypericin increased AP duration, which might be ascribed to its effect on I(A) and I(K) currents. As a small increase in AP duration could lead to a dramatic increase in synaptic efficiency, our results imply that hypericin might exert its antidepressant effects by enhancing presynaptic efficiency.