[Progress in treatment of primary mediastinal large B-cell lymphoma].

Primary mediastinal large B-cell lymphoma (PMBCL) is an aggressive B-cell lymphoma originating from the thymus, which has different clinical and biological characteristics from diffuse large B-cell lymphoma, NOS. PMBCL tends to occur in young women, usually presenting as a large anterior mediastinal mass. Most patients are in stage Ⅰ-Ⅱ at the time of presentation. There is no standard prognostic scoring system for PMBCL. Immunochemotherapy is commonly used in the treatment of PMBCL, but the optimal first-line treatment has not been determined, and the status of radiotherapy is controversial. The value of PET-CT guided therapy needs to be further verified. Relapsed/refractory PMBCL has a poor prognosis, while novel therapies such as PD-1 inhibitors, brentuximab vedotin, and CAR-T can help improve survival in these patients.

Borderline epithelial ovarian tumors: what the radiologist should know.

Ovarian borderline tumors are neoplasms of epithelial origin that are typically present in young patients and tend to have a less aggressive clinical course than malignant tumors. Accurate diagnosis and staging of borderline tumors has important prognostic and management implications (like fertility-sparing procedures) for women of child-bearing age. This article will review the sonographic, CT, and MRI features of borderline epithelial ovarian tumors with histopathologic correlation. Borderline tumors have less soft tissue and thinner walls/septations than malignant tumors. Serous borderline tumors more commonly have papillary projections, which can simulate the appearance of a sea anemone. Mucinous borderline tumors often are larger, multi-cystic, and more commonly unilateral. The borderline mucinous tumors may also present with pseudomyxoma peritonei, which can make it difficult to distinguish from malignant mucinous carcinoma. Ultrasound is usually the first-line modality for imaging these tumors with MRI reserved for further characterizing indeterminate cases. CT is best used to stage tumors for both locoregional and distant metastatic disease. Overall, however, the imaging features overlap with both benign and malignant ovarian tumors. Despite this, it is important for the radiologist to be familiar with the imaging appearances of borderline tumors because they can present in younger patients and may benefit from different clinical/surgical management.

MiR-587 acts as an oncogene in non-small-cell lung carcinoma via reducing CYLD expression.

OBJECTIVE: This study aims to explore the cancer-associated functions of microRNA-587 (miR-587) in the development of non-small-cell lung carcinoma (NSCLC) and the molecular mechanism. PATIENTS AND METHODS: Relative expression levels of miR-587 and CYLD in NSCLC samples were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Proliferative and migratory abilities in A549 and H1299 cells with overexpressed miR-587 were examined by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. The regulatory interaction between miR-587 and CYLD was determined by Dual-Luciferase reporter assay and Pearson correlation test. At last, the co-regulation of miR-587 and CYLD on NSCLC cell functions was assessed by rescue experiments. RESULTS: MiR-587 was upregulated in NSCLC samples and closely linked to tumor staging, whereas CYLD was downregulated and negatively correlated to that of miR-587. Survival analysis suggested that miR-587 was an unfavorable factor to the prognosis of NSCLC. Overexpression of miR-587 stimulated proliferative and migratory abilities in A549 and H1299 cells. CYLD was the downstream gene binding miR-587. Overexpression of CYLD could partially abolish the regulatory effects of overexpressed miR-587 on promoting proliferative and migratory abilities in NSCLC cells. CONCLUSIONS: MiR-587 stimulates proliferative and migratory abilities in NSCLC by downregulating CYLD, thus aggravating the progression of NSCLC.

[A retrospective study on combined modality therapy with or without surgery for advanced hypopharyngeal squamous cell carcinoma: an analysis of 119 cases].

Objective: To compare the treatment outcomes for locally advanced hypopharyngeal carcinoma between surgery plus radio(chemo) therapy(SRT) and non-surgery chemoradiotherapy(CRT). Methods: A total of 119 patients diagnosed with advanced hypopharyngeal carcinoma without distant metastases between 2010 and 2014 were identified in the Chinese People's Liberation Army General Hospital, and they were divided into 2 groups: 42 cases in SRT group and 77 cases in CRT group. Patients' clinical information was collected. Survival rates and prognostic factors were analyzed by the Kaplan-Meier method with SPSS 23.0 software. The survival rates, laryngeal preservation rates and complication rates were compared between the two groups using the chi-square test.Among the 119 patients, 112 were males and 7 were females. Age ranged from 27 to 78 years, with an average age of 57 years. Results: There were no significant difference between the SRT and CRT group for five-year disease-free survival (DFS, 53.9% vs. 45.1%, χ(2)=1.251, P=0.263) and overall survival (OS, 54.9% vs. 45.6%, χ(2)=1.749, P=0.186). Compared to SRT group, CRT group did not showed the significant increase of treatment complications (χ(2)=0.858, P=0.354), with a higher laryngeal preservation rate (50.0% vs. 71.4%, χ(2)=6.493, P=0.011). Conclusions: Advanced hypopharyngeal carcinoma is of high malignancy and poor prognosis. Combined modality treatment is a main approach for advanced hypopharyngeal cancer. SRT offers disease-free survival and overall survival rates equivalent to CRT, but with a higher laryngeal preservation rate.

Separation of brown carbon from black carbon for IMPROVE and Chemical Speciation Network PM2.5 samples.

The replacement of the Desert Research Institute (DRI) model 2001 with model 2015 thermal/optical analyzers (TOAs) results in continuity of the long-term organic carbon (OC) and elemental carbon (EC) database, and it adds optical information with no additional carbon analysis effort. The value of multiwavelength light attenuation is that light absorption due to black carbon (BC) can be separated from that of brown carbon (BrC), with subsequent attribution to known sources such as biomass burning and secondary organic aerosols. There is evidence of filter loading effects for the 25% of all samples with the highest EC concentrations based on the ratio of light attenuation to EC. Loading corrections similar to those used for the seven-wavelength aethalometer need to be investigated. On average, nonurban Interagency Monitoring of PROtected Visual Environments (IMPROVE) samples show higher BrC fractions of short-wavelength absorption than urban Chemical Speciation Network (CSN) samples, owing to greater influence from biomass burning and aged aerosols, as well as to higher primary BC contributions from engine exhaust at urban sites. Sequential samples taken during an Everglades National Park wildfire demonstrate the evolution from flaming to smoldering combustion, with the BrC fraction increasing as smoldering begins to dominate the fire event. IMPLICATIONS: The inclusion of seven wavelengths in thermal/optical carbon analysis of speciated PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 µm) samples allows contributions from biomass burning and secondary organic aerosols to be estimated. This separation is useful for evaluating control strategy effectiveness, identifying exceptional events, and determining natural visibility conditions.

[Clinical value of classified detection of circulating tumor cells in peripheral blood of NSCLC patients].

OBJECTIVE: To investigate the clinical value of detection of circulating tumor cells (CTCs) classified by epithelial cell adhesion molecule (EpCAM) in peripheral blood of patients with non-small cell lung cancer (NSCLC). METHODS: Peripheral blood samples (7.5 ml each time) were collected from 47 NSCLC patients. Among them, blood samples were collected at the end of each therapy-cycle in three patients for longitudinal monitoring of CTCs. CTCs were enriched by the depletion of leucocytes using a magnetic bead separation technique, stained with EpCAM, cytokeratin 7/8 and their isotypic control antibodies, respectively, and then identified and counted by multi-parameter flow cytometry. RESULTS: In the blood samples from 47 patients, EpCAM-positive CTCs were detected in 64.3%(9/14), 40.0%(4/10) and 43.5%(10/23) of patients in stages Ⅰ-Ⅱ, Ⅲ and Ⅳ, respectively. EpCAM-negative CTCs were detected in 78.6%(11/14), 90.0%(9/10) and 91.3%(21/23) of patients in stage Ⅰ-Ⅱ, Ⅲ, and Ⅳ, respectively. The total detection rates of EpCAM-positive and EpCAM-negative CTCs were 48.9%(23/47) and 87.2%(41/47), respectively, showing a statistically significant difference between them (P<0.001). According to the stage of the cancer, there was a significant difference between the detection rates of the two types of CTCs in patients of stage Ⅳ(P=0.001), but not in stage Ⅰ-Ⅱ and Ⅲ (P>0.05). The number of EpCAM-negative CTCs was significantly higher than that of EpCAM-positive CTCs in all stages (P<0.05). The frequency of patients with the percentage of EpCAM-negative CTCs >90% was significantly higher in stage Ⅳ patients than that in stage Ⅰ-Ⅱ cases (P=0.030), while the frequency of patients with the percentage of EpCAM-negative CTCs between 50%~90% was significantly lower in the stage Ⅳ than that in the stage Ⅰ-Ⅱ patients (P=0.001). The treatment of most patients with EpCAM-negative CTCs >50% showed to be ineffective (P=0.033). CONCLUSION: Detection of CTCs classified by EpCAM in peripheral blood is helpful in evaluating the distant metastasis and treatment effectiveness of NSCLC patients.

Establishment of an animal model of spontaneous cervical lymph node metastasis of laryngeal squamous cell carcinoma and obtaining laryngocarcinoma cells with high metastatic potential.

To establish an animal model of spontaneous cervical lymph node metastasis of laryngeal squamous cell carcinoma and obtain laryngocarcinoma cells with high metastatic potential, laryngeal squamous cell carcinoma cell line HEP-2 in logarithmic phase were inoculated under the lingual margin mucosa of nude mice. HEP-2 cells metastasized to the cervical lymph nodes were isolated, cultured, and re-inoculated under the lingual margin mucosa of nude mice twice. The tumor formation in the tongue and in the cervical lymph nodes was confirmed by pathological examination. Carcinoma cells' ability of invasion and migration was detected by transwell assay. Human specific Alu sequences were detected by PCR, which indicated that the tumor cells originated from human laryngeal squamous cell carcinoma cell line HEP-2. Finally, an animal model of spontaneous lymph node metastasis of laryngeal squamous cell carcinoma was successfully established. Laryngeal squamous cell carcinoma cells with high metastatic potential to lymph nodes were obtained through repeated inoculations. .

Neuroprotective effects of neurokinin receptor one in dopaminergic neurons are mediated through Akt/PKB cell signaling pathway.

Neurokinin one (NK1) receptor is Substance P (SP) receptor and it is abundantly distributed in the basal ganglia. Growing evidences were shown on their possible roles in the pathogenesis and treatment of Parkinson's disease (PD). NK1 receptor is a kind of G-protein-coupled-receptor (GPCR) and it links to various downstream survival signaling pathways. In the present study, treatment of NK1 receptor agonist septide [(Pyr6, Pro9)-SP (6-11)] was found to ameliorate the motor deficit in 6-hydroxydopamine (6-OHDA) lesioned rats in apomorphine rotation test. Septide treatments were also demonstrated to provide neuroprotection. In 6-OHDA lesioned rats, protection of TH immunoreactive neurons and terminals in substantia nigra (SN) and striatum was found after septide treatment. In SH-SY5Y cultures, cytotoxicity of 6-OHDA was reduced by septide pretreatment. In addition, up-regulations of phosphorylated serine-threonine kinase Akt and phosphorylated mitochondrial apoptotic protein BAD were observed in both in vivo and in vitro models, indicating the inhibition of apoptotic pathway by septide. In conclusion, septide could trigger the pro-survival Akt/PKB signaling pathway and protect dopaminergic neurons in in vivo and in vitro models against 6-OHDA toxicity. Therefore septide treatment may have therapeutic implications in treatment of PD.

The effect of microwave and bipolar radio-frequency ablation in the surgical treatment of permanent atrial fibrillation during valve surgery.

BACKGROUND: Atrial fibrillation (AF) is a frequent problem in patients undergoing valve surgery. This study compared microwave and bipolar radio-frequency ablation of the left atrium in AF patients undergoing valve surgery. METHODS: Patients who required left atrial ablation for permanent AF (duration > 6 months) during valve surgery were randomized to a microwave group (n = 94) or a radio-frequency group (n = 93). Regular follow-up was carried out at 3, 6, 9 and 12 months post-procedure and annually thereafter. RESULTS: There were 4 postoperative deaths in the microwave group and 2 in the radio-frequency group. The median follow-up for all patients was 24.0 months (range: 12-36.0 months). Freedom from AF recurrence was significantly higher in the radio-frequency group than in the microwave group at 3 months (85.7 vs. 72.2 %, P = 0.026), 6 months (87.9 vs. 73.3 %%, P = 0.013), 9 months (84.6 vs. 68.9 %, P = 0.012), 12 months (84.6 vs. 67.8 %%, P = 0.008), and 24 months (88.7 vs. 71.2 %, P = 0.022) and at the latest follow-up (81.3 vs. 65.6 %, P = 0.016). CONCLUSION: Bipolar radio-frequency ablation is superior to microwave ablation for the treatment of permanent AF in patients undergoing valve surgery.

Potential application of induced pluripotent stem cells in cell replacement therapy for Parkinson's disease.

Parkinson's disease (PD), a common degenerative disease in humans, is known to result from loss of dopamine neurons in the substantia nigra and is characterized by severe motor symptoms of tremor, rigidity, bradykinsia and postural instability. Although levodopa administration, surgical neural lesion, and deep brain stimulation have been shown to be effective in improving parkinsonian symptoms, cell replacement therapy such as transplantation of dopamine neurons or neural stem cells has shed new light on an alternative treatment strategy for PD. While the difficulty in securing donor dopamine neurons and the immuno-rejection of neural transplants largely hinder application of neural transplants in clinical treatment, induced pluripotent stem cells (iPS cells) derived from somatic cells may represent a powerful tool for studying the pathogenesis of PD and provide a source for replacement therapies in this neurodegenerative disease. Yamanaka et al. [2006, 2007] first succeeded in generating iPS cells by reprogramming fibroblasts with four transcription factors, Oct4, Sox2, Klf4, and c-Myc in both mouse and human. Animal studies have further shown that iPS cells from fibroblasts could be induced into dopamine neurons and transplantation of these cells within the central nervous system improved motor symptoms in the 6-OHDA model of PD. More interestingly, neural stem cells or fibroblasts from patients can be efficiently reprogrammed and subsequently differentiated into dopamine neurons. Derivation of patient-specific iPS cells and subsequent differentiation into dopamine neurons would provide a disease-specific in vitro model for disease pathology, drug screening and personalized stem cell therapy for PD. This review summarizes current methods and modifications in producing iPS cells from somatic cells as well as safety concerns of reprogramming procedures. Novel reprogramming strategies that deter abnormal permanent genetic and epigenetic alterations are essential for propagating clinically-qualified iPS cells. Future investigations into cell transforming and reprogramming processes are needed to generate the disease-specific iPS cells for personalized regeneration medicine of PD patients by disclosing detailed reprogramming mechanisms.

Psychosexual adjustment and age factors in 130 men undergone hypospadias surgery in a Chinese hospital.

The study investigated the psychosexual status and sexual function in adults who had hypospadias surgery at different ages. A detailed questionnaire was mailed to 130 patients who underwent hypospadias surgery between January 1988 and December 2007, and 50 healthy males who served as the control group. The patients were divided into three groups based on their age at which surgery was completed: group A (n=32; <10 years); group B (n=45; 10-18 years); and group C (n=53; >18 years). The Zung Self-Rating Anxiety Scale and The Zung Self-Rating Depression Scale were used to assess psychosexual status; a designed questionnaire and the International Index of Erectile Function-5 were used to assess sexual function. The incidence of anxiety and depression was significantly higher in patients than that in controls (P < 0.001), and was correlated with the age at which surgery was completed. The length and circumference of penises in patients were shorter than those of control groups with statistically significant differences (P < 0.01). There were no significant differences between patients and controls regarding libido strength, overall sexual satisfaction and erectile function (P > 0.05). In conclusion, difference existed in certain aspects of psychosexual and penile development between patients and controls. Hypospadias surgery should be performed early.

Elucidating therapeutic effects on patients with hepatocellular carcinoma and main portal vein thrombosis.

BACKGROUND/AIMS: The survival duration for patients diagnosed with hepatocellular carcinoma (HCC) with main portal vein thrombosis (MPVT) was usually less than 3 months. The aim of this study is to elucidate whether treatment can prolong the survival for such patients. METHODOLOGY: Retrospectively we analyzed the clinical features and outcomes of 63 patients with HCC and MPVT over a 7-year period. Three therapeutic modalities--transcatheter arterial chemotherapy (TAC) with or without radiotherapy (RT), and systemic chemotherapy--were applied. RESULTS: The patients were divided into two groups: 34 (54%) patients were treated, while the remaining 29 (46%) were not. Multivariate analysis revealed that Child-Pugh class, Okuda stage for HCC and the presence of treatment were the principal factors to predict survival. The survival was significantly longer in treated patients than those untreated both in the Child-Pugh class A or B patients. Significantly longer survival is evident in patients treated by TAC combing RT compared to those underwent TAC alone, systemic chemotherapy or no treatment. CONCLUSIONS: The survival of Child-Pugh class A or B patients can be extended by the use of an appropriate therapeutic modality. TAC combined with RT did the best benefit to prolong survival in such patients.

Laser assisted ultrasound guided aspiration improves procedure time and reduces number of withdrawals.

This study evaluated the performance of in-vitro freehand aspiration of a simulated cyst with ultrasound aspiration guided by a newly designed laser assisted (LA) device. The LA device was equipped with an adjustable light source generating a sector light plane. This laser light plane was parallel to and overlapped the ultrasound acoustical plane, to help with needle positioning. Five operators randomly performed 30 freehand or LA ultrasound guided aspirations of a simulated cyst. The frequency was set at 8 MHz and depth at 4 cm. Procedure time and number of syringe withdrawals were statistically compared before and after using the LA device. Both experienced and inexperienced operators required significantly less time to perform the aspiration and had fewer syringe withdrawals when using the LA device. The LA device provides a reference plane in space, allowing the operator to more accurately position and adjust needle direction. Additional in-vivo testing is required to test the clinical practicability.

Detection of human parvovirus B19 in papillary thyroid carcinoma.

To evaluate whether parvovirus B19, a common human pathogen, was also involved in papillary thyroid carcinoma (PTC), 112 paraffin-embedded thyroid specimens of benign nodules, papillary, medullary and follicular carcinomas, and normal controls were examined for B19 DNA and capsid protein by nested PCR, in situ hybridisation (ISH) and immunohistochemistry (IHC). The expression of the nuclear factor-kappaB (NF-kappaB) was investigated by IHC. The results showed B19 DNA commonly exists in human thyroid tissues; however, there were significant differences between PTC group and normal controls, and between PTC and nonneoplastic adjacent tissues (P<0.001). The presence of viral DNA in PTC neoplastic epithelium was confirmed by laser-capture microdissection and sequencing of nested PCR products. B19 capsid protein in PTC group was significantly higher than that of all the control groups and nonneoplastic adjacent tissues (P

Solitary actinomycotic abscesses of liver: report of two cases.

Hepatic actinomycotic abscesses are rare and secondary to other intra-abdominal infections. History of intra-abdominal surgery is a principal contributing factor for the abscess formation. Patients with hepatic actinomycotic abscess may suffer from fever, malaise, abdominal pain and bodyweight loss. The clinical progress of actinomycotic abscess is more indolent than the usual course of other pyogenic abscess. It is sometimes diagnosed as malignancy. This report consists of two cases of hepatic actinomycotic abscess mimicking tumours. Laboratory data revealed elevated alkaline phosphatase and leucocytosis. The abdominal computed tomography scan showed multiloculated lesions with peripheral contrast enhancement appearance. Diagnosis confirmation was based on the typical histologic feature of sulfur granules with inflammatory process by echo-guided fine needle biopsy or surgical specimen. These two cases were resolved with extended courses of intravenous and oral penicillin treatment.

Splenic tumour: a clinicopathological study.

Splenic tumours are occasionally found during routine physical check-ups or elective abdominal image studies. Histologically, most splenic tumours are of benign vascular origin. To avoid unnecessary surgery for asymptomatic patients with benign splenic tumours and clarify the clinicopathological features of spleen tumours, this study gathered 44 cases of primary or isolated metastatic spleen tumours confirmed by pathology from surgery specimens or biopsies. The differences in clinicopathological features and image presentations between benign and malignant spleen tumour were investigated. Thirty-two cases involved benign tumours while 12 cases were malignant. Among the benign tumours, vascular originating tumours were most common (with 14 cases of cavernous haemangiomas, 13 cases of lymphangioma, three cases of lymphangiohaemangioma and one case of Littoral cell angioma). Notably, one, case of inflammatory pseudotumour because of Schistosoma parasite infection was also noted. Among the malignant tumours, there were four cases of angiosarcomas with vascular endothelium origins, as well as lymphomas and six metastatic tumours. Image studies were non-specific. Image study alone is an inadequate basis for making differential diagnoses between benign and malignant tumours. Instead, pathological studies are required for a final diagnosis. Using previous studies and this investigation, fine needle aspiration biopsy of spleen tumours with the help of ultrasonic or computed tomography appears a safe and effective method for obtaining biopsy specimens. Splenectomy is recommended only for patients with malignancies or complications such as intractable abdominal pain, coagulopathy or tumour rupture with an unstable haemodynamic state.

Neurokinin peptides and neurokinin receptors as potential therapeutic intervention targets of basal ganglia in the prevention and treatment of Parkinson's disease.

Parkinson's disease (PD) is a serious motor disorder and it is the second most common brain degenerative disease in human. PD is known to be caused by degeneration of dopamine neurons in the substantia nigra but the cause of cell death is largely unknown. Mammalian neurokinins [NKs] are a group of neuropeptides that include substance P (SP; neurokinin-1, NK-1), substance K (SK; NK-2; neurokinin A), and neuromedin K (NK; NK-3; neurokinin B). Their biological effects as neurotransmitters, neuromodulators, or neurotrophic-like factors are mediated by three distinct neurokinin receptors, namely SP receptor (SPR: NK-1 receptor, NK-1R), SKR (NK-2R), and NKR (NK-3R). Several lines of evidence have indicated that neurokinins are implicated in the pathogenesis of PD. First, decreases of SP level and SP-immunoreactivity have been found in nigral and striatal tissues of animals with PD and postmortem PD patients. Second, NKs exert neuroprotective effects on neurons. In addition, NK receptors, namely NK-1 and NK-3 receptors, are abundantly localized in dopaminergic and cholinergic neurons of the basal ganglia, indicating that these neurons are under the physiological regulation of NKs. Moreover, modulation in motor activity occurred in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, PD animal model, after systemic administration of NK receptor agonists. NKs and NK receptors, therefore, might be important molecules that are associated with functions and survival of neurons in the basal ganglia, in particular the dopamine neurons. Further studies should be devoted to elucidate the functional roles of NK systems in (a) the neuropathogenesis and neuroprotection during the course of PD, (b) the efficacy of NK receptor drugs towards PD, and (c) potential therapeutic intervention that targets at the prevention or treatment of PD.

Differential expression of NMDA and AMPA receptor subunits in DARPP-32-containing neurons of the cerebral cortex, hippocampus and neostriatum of rats.

Dopamine and cyclic adenosine 3',5'-monophosphate-regulated phosphoprotein, 32 kDa (DARPP-32) is a key element of dopamine/D1/DARPP-32/protein phosphatase-1 (PP-1) signaling cascades of mammalian brain. We are interested in the expression patterns of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors in DARPP-32-containing neurons, which may constitute morphological basis for interaction between dopamine and ionotropic glutamate receptors in dopaminoceptive cells. Double immunofluorescence was performed to visualize neurons showing coexpression of DARPP-32 with NMDA or AMPA receptor subunits (i.e., NR1, NR2a/b, glutamate receptor subunit 1 [GluR1], GluR2/3, and GluR4) in the forebrains of rats. Distribution of DARPP-32-positive neurons completely or partially overlapped with that of NMDA receptor- or AMPA receptor-immunoreactive ones in the frontal and parietal cortex, hippocampus and neostriatum, and neurons double-labeled with DARPP-32/NR1, DARPP-32/NR2a/b, DARPP-32/GluR1, DARPP-32/GluR2/3, or DARPP-32/GluR4 immunoreactivity were numerously observed. Semiquantification analysis indicated that most of DARPP-32-containing neurons (86-98%) expressed NR1, NR2a/b and GluR2/3, while less of them (14-90%) expressed GluR1 and GluR4. Although high rates (90-98%) of DARPP-32-positive cells expressed NMDA receptors in all regions above, variant percentages of them expressing AMPA receptor subunits were observed among the cortex (54-90%), hippocampus (59-97%) and neostriatum (14-97%). The study presents differential expression patterns of NMDA and AMPA receptors in DARPP-32-postive neurons in these forebrain regions. Taken together with previous reports, the present data suggest that interaction between dopamine and glutamate receptors may occur in the dopaminoceptive neurons with distinct receptor compositions and may be involved in modulating neuronal properties and excitotoxicity in mammalian forebrain.

Analysis of binding domain and function of chimeric mu/kappa opioid receptors to ohmefentanyl stereoisomers.

AIM: To investigate specific domains in mu opioid receptors that accounted for selective binding of three stereoisomers of ohmefentanyl (Ohm9204, Ohm9202, and Ohm9203) and study the function of chimera II. METHODS: Rat mu and kappa opioid receptors (RMOR, RKOR) and four mu/kappa chimeric receptors (chimeras) I, II, III, and IV were transiently expressed in COS-1 cells. The binding ability and binding domain of receptor to ligands were determined by radioactive ligand and receptor binding experiments. Through measuring cellular cAMP levels, we studied the function of chimera II in mediating signal transduction. RESULTS: Binding affinities of four chimeric receptors were similar to wild type opioid receptors (RMOR and RKOR). The binding affinities of Ohm9204 and Ohm9202 to chimera II were similar to that of RMOR. The binding affinities of Ohm9203 to all six receptors were low. U50488 possessed high binding affinity to chimera I, however dynorphie A(1-9) had some binding affinity to chimera II that was similar to RKOR, which indicated the domains of RKOR accounting for selectively binding to peptide ligand dynorphie A(1-9) and nonpeptide ligand U50488 were different. The efficacy of Ohm9204 and Ohm9203 on inhibiting forskolin-stimulated cAMP accumulation in cells transfected with chimera II was similar to that in cells transfected with RMOR. CONCLUSION: Replacing 194-268 residues of RMOR with 185-262 residues of RKOR does not influence the ability of mu opioid receptor to bind Ohm9204 and Ohm9202 and the receptor mediated inhibition of cellular cAMP level.