Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon.

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst) eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays.

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kß x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

Pharmacology of grapiprant, a novel EP4 antagonist: receptor binding, efficacy in a rodent postoperative pain model, and a dose estimation for controlling pain in dogs.

Grapiprant is an analgesic and anti-inflammatory drug in the piprant class that was approved in March 2016 by FDA's Center for Veterinary Medicine for the control of pain and inflammation associated with osteoarthritis (OA) in dogs. Grapiprant functions as a selective antagonist of the EP4 receptor, one of the four prostaglandin E2 (PGE2 ) receptor subtypes. The EP4 receptor mediates PGE2 -elicited nociception, and grapiprant has been shown to decrease pain in several rat inflammatory pain models. It was also effective in reducing pain associated with OA in humans, providing evidence for its mechanism of action in these species. The estimated canine efficacy dose of between 1.3 and 1.7 mg/kg, p.o. with a methylcellulose suspension, once a day, was predicted based on calculations from comparative affinity of grapiprant to the dog, rat, and human EP4 receptors, serum protein binding, effective doses defined in rat models of pain and inflammation, and human clinical studies. The results of this study guided the doses to be tested in the pilot study and demonstrated the usefulness of the efficacy dose prediction method. The approved commercial tablet dose of grapiprant is 2 mg/kg once a day for the control of pain and inflammation associated with OA in dogs.

Abnormal cell proliferation in the p75NTR-positive basal cell compartment of the esophageal epithelium during squamous carcinogenesis.

The low affinity neurotrophin receptor p75NTR is known to be expressed in the mitotically quiescent basal layer (BL) of the normal esophageal epithelium. The aim of the present study was to detect oncogenic changes in the p75NTR-positive BL during esophageal squamous carcinogenesis. The normal epithelium (NE), low-grade intraepithelial neoplasia (LGN), high-grade intraepithelial neoplasia (HGN), and esophageal squamous carcinoma (SCC), in which invasion was limited to the muscularis mucosa, were obtained from surgically removed esophagi. The expression of p75NTR, the proliferation marker ki67, hTERT, p53, and p63 was examined immunohistochemically. The expression of p75NTR was detected in these tissues with average staining indexes (number of stained cells/100 nucleated cells; SI) of 1.00, 0.99, 0.81, and 0.73, respectively. The expression of ki67 in the BL significantly increased with the progression from LGN to HGN. The expression of hTERT and p53 significantly increased with the progression from NE to LGN, and then increased in a stepwise manner in HGN and SCC, with SI (hTERT/p53) of 0.10/0.11, 0.32/0.45, 0.50/0.72, and 0.65/0.61, respectively. The expression of p63 showed no significant difference among NE, LGN, HGN, and SCC, with SI of 0.82, 0.77, 0.85, and 0.87, respectively. A correlation was observed between the expression of ki67 and p53 (P = 0.005), while a negative correlation was found between p75NTR and hTERT (P = 0.01). Our results demonstrated that phenotypic changes from quiescent to active proliferation in the p75NTR-positive BL occurred during the progression from LGN to HGN. The altered expression of hTERT and p53 in the BL was detected in LGN, which suggested that additional oncogenic events that disrupt mitotic regulation in the p75NTR-positive quiescent BL may play a crucial role in malignant transformation. Further investigations using the isolation and tracing of p75NTR-positive cells in precancerous epithelia may provide us with a better understanding of squamous carcinogenesis.

Proton beam therapy for malignancy in Bloom syndrome.

BACKGROUND AND PURPOSE: Bloom syndrome is a DNA repair disorder that is hypersensitive to radiotherapy. We describe the first case in which proton beam therapy (PBT) was used in a patient with Bloom syndrome to treat oropharyngeal cancer. PATIENTS AND METHODS: The patient was a 32-year-old woman with Bloom syndrome who was diagnosed with oropharyngeal cancer staged as T2N2bM0 poorly differentiated squamous cell carcinoma. The primary tumor was located on the right tongue base and extended to the right lateral pharyngeal wall. Several right upper region lymph nodes were positive for metastases. RESULTS: We selected PBT in anticipation of dose reduction to normal tissue. The clinical target volume was defined as the area of the primary tumor and lymph node metastases plus an 8-mm margin. After treatment with 36 GyE (Gray equivalent) in 20 fractions (4-5 fractions per week), dietary intake was decreased by mucositis and intravenous hyperalimentation was started. Termination of treatment for 2.5 weeks was required to relieve mucositis. Administration of 59.4 GyE in 33 fractions markedly reduced the size of the primary tumor, but also caused moderate mucositis that required termination of PBT. One month later, lung metastases and breast cancer developed and the patient died 9 months after PBT. At this time the reduction in size of the primary tumor was maintained without severe late toxicity. CONCLUSION: We obtained almost complete response for a radiosensitive patient with a deficiency of DNA repair, indicating the excellent dose concentration of proton beam therapy.

Reirradiation for recurrent malignant brain tumor with radiotherapy or proton beam therapy. Technical considerations based on experience at a single institution.

BACKGROUND AND PURPOSE: Radiotherapy for recurrent malignant brain tumors is usually limited because of the dose tolerance of the normal brain tissue. The goal of the study was to evaluate the efficacy and feasibility of reirradiation for patients with recurrent malignant brain tumors. PATIENTS AND METHODS: The subjects comprised 26 patients with recurrent malignant brain tumors treated with conventional radiotherapy (RT, n = 8), stereotactic radiotherapy (SRT, n = 10), and proton beam therapy (PBT, n = 8) at our institute. Fifteen patients had glioblastoma, 6 had WHO grade 3 glioma, and 5 had other tumors. The dose of initial radiotherapy was 34.5-94.4 Gy. Different radiation schedules were compared using the equivalent dose in 2-Gy fractions. RESULTS: Reirradiation was completed in all patients without a severe acute reaction. The reirradiation doses were 30-60 Gy (median, 42.3 Gy) and the total doses for the initial and second treatments were 64.5-150.4 Gy (median, 100.0 Gy). Currently, 11 patients are alive (median follow-up period, 19.4 months) and 15 are dead. The median survival and local control periods after reirradiation of the 26 patients were 18.3 and 9.3 months, respectively. For the 15 patients with glioblastoma, these periods were 13.1 and 11.0 months, respectively. Two patients showed radiation necrosis that was treated by surgery or conservative therapy. CONCLUSION: Reirradiation for recurrent malignant brain tumor using conventional RT, SRT, or PBT was feasible and effective in selected cases. Further investigation is needed for treatment optimization for a given patient and tumor condition.

Role of aquaporin-5 in gallbladder carcinoma.

BACKGROUND/PURPOSE: Aquaporins (AQPs) are important in controlling bile formation. However, the exact role in human gallbladder carcinogenesis has not yet been defined. METHODS: AQP-5-expressing gallbladder carcinoma (GBC) cell lines (NOZ) were transfected with anti-AQP-5 small interfering RNA (siRNA). Growth, migration, invasion assay, and drug susceptibility tests were performed. Next, microRNA (miRNA) expression was analyzed by miRNA oligo chip (3D-Gene®). AQP-5 and AQP-5-related miRNA target gene expressions were also analyzed using tissue microarray (TMA) in 44 GBC samples. RESULTS: Treatment with AQP-5 siRNA decreased cell proliferation, migration, and invasion. On the other hand, those cells increased IC50 of gemcitabine. By performing miRNA assays, miR-29b, -200a, and -21 were shown to be highly overexpressed in cells treated with AQP-5 siRNA NOZ. When focusing on miR-21, phosphatase and tensin homolog (PTEN) was found to be a target of miR-21. In the TMA, AQP-5/PTEN coexpression was significantly associated with the depth of invasion and MIB-1 index (p = 0.003, 0.010). Survival of patients with a high AQP-5/PTEN coexpression was longer than that of patients with a low coexpression (p = 0.003). CONCLUSIONS: Our result suggested that miR-21 and PTEN may contribute to the role of AQP-5 in GBC. AQP-5 and PTEN cascades are favorable biomarkers of GBC.

Video-assisted thoracoscopic lobectomy for clinical stage I non-small cell lung cancer: experience with 111 consecutive patients demonstrating comorbidity.

AIM: The outcomes of video-assisted thoracoscopic lobectomy for clinical stage I non-small cell lung cancer (NSCLC) patients with comorbidities were examined to determine the technical feasibility and safety of this procedure. METHODS: Between January 2002 and December 2007, 111 consecutive patients with suspected stage I lung cancer, who individually had one or more comorbidities cited in the modified Kaplan-Feinstein Index, were scheduled for a video-assisted thoracoscopic lobectomy. The demographic, perioperative, and outcome variables were assessed. RESULTS: One hundred of 111 patients had non-small cell lung cancer. Ninety-nine patients underwent successful video-assisted thoracoscopic lobectomies, while there was one conversion because of a hemorrhage from the pulmonary artery in the early stage. Including this one conversion, no patients required a blood transfusion during surgery or postoperatively. There were no intraoperative or in-hospital deaths. No complications occurred in 78 (78.8%) of 99 patients. Only one patient (1.0%) with a Kaplan-Feinstein Index Score of severe grade contracted pneumonia indicating grade 3 (severe), whereas the remaining 20 patients had grade 1 (mild) or 2 (moderate) complications. At a median follow-up of 40 months, the overall 3-year survival rates for postoperative stage IA (N.=52); IB (N.=26); and II or more (N.=21) were 100%; 78%; and 71%, respectively. CONCLUSION: A video-assisted thoracoscopic lobectomy is therefore considered to be a feasible and safe procedure for clinical stage I NSCLC even in patients with comorbidities.

Active hexose correlated compound inhibits the expression of proinflammatory biomarker iNOS in hepatocytes.

BACKGROUND/AIMS: Excess production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been implicated as proinflammatory biomarker in liver injury. The application of active hexose correlated compound (AHCC) as a functional food in complementary and alternative medicine has increased. The possibility that AHCC might inhibit iNOS induction was investigated as a potential liver-protective effect. METHODS: Hepatocytes were isolated from rats by collagenase perfusion and cultured. Primary cultured hepatocytes were treated with interleukin-1ß in the presence or absence of AHCC-sugar fraction (AHCC-SF). RESULTS AND CONCLUSION: AHCC-SF inhibited the production of NO and reduced expressions of iNOS mRNA and its protein. AHCC-SF had no effects on either IκB degradation or nuclear factor-κB (NF-κB) activation. In contrast, AHCC-SF inhibited the upregulation of type I interleukin-1 receptor (IL-1RI) through the inhibition of Akt phosphorylation. Transfection experiments with iNOS promoter-luciferase constructs revealed that AHCC-SF reduced the levels of iNOS mRNA at both promoter transactivation and mRNA stabilization steps. AHCC-SF inhibited the expression of iNOS gene antisense transcript, which is involved in iNOS mRNA stabilization. These findings demonstrate that AHCC-SF suppresses iNOS gene expression through a IκB/NF-κB-independent but Akt/IL-1RI-dependent pathway, resulting in the reduction of NO production. AHCC-SF may have therapeutic potential for various liver injuries.

Modulatory effects of the GABAergic basal ganglia neurons on the PPN and the muscle tone inhibitory system in cats.

Pedunculopontine tegmental nucleus (PPN) contributes to the control muscle tone by modulating the activities of pontomedullary reticulospinal systems during wakefulness and rapid eye movement (REM) sleep. The PPN receives GABAergic projection from the substantia nigra pars reticulata (SNr), an output nucleus of the basal ganglia. Here we examined how GABAergic SNr-PPN projection controls the activity of the pontomedullary reticulospinal tract that constitutes muscle tone inhibitory system. Intracellular recording was made from 121 motoneurons in the lumbosacral segments in decerebrate cats (n=14). Short train pulses of stimuli (3 pulses with 5 ms intervals, 10-40 mA) applied to the PPN, where cholinergic neurons were densely distributed, evoked eye movements toward to the contralateral direction and bilaterally suppressed extensor muscle activities. The identical PPN stimulation induced IPSPs, which had a peak latency of 40-50 ms with a duration of 40-50 ms, in extensor and flexor motoneurons. The late-latency IPSPs were mediated by chloride ions. Microinjection of atropine sulfate (20 mM, 0.25 ml) into the pontine reticular formation (PRF) reduced the amplitude of the IPSPs. Although conditioning stimuli applied to the SNr (40-60 mA and 100 Hz) alone did not induce any postsynaptic effects on motoneurons, it reduced the amplitude of the PPN-induced IPSPs. Subsequent injection of bicuculline (5 mM, 0.25 ml) into the PPN blocked the SNr effects. Microinjections of NMDA (5 mM, 0.25 ml) and muscimol (5 mM, 0.25 ml) into the SNr reduced and increased the amplitude of the PPN-induced IPSPs, respectively. These results suggest that GABAergic basal ganglia output controls postural muscle tone by modulating the activity of cholinergic PPN neurons which activate the muscle tone inhibitory system. The SNr-PPN projection may contribute to not only control of muscle tone during movements in wakefulness but also modulation of muscular atonia of REM sleep. Dysfunction of the SNr-PPN projection may therefore be involved in sleep disturbances in basal ganglia disorders.

Does preoperative enhanced CT predict requirement of intestinal resection in the patients with incarcerated myopectineal hernias containing small bowel?

PURPOSE: Bowel wall enhancement on CT imaging is considered one of the useful features for the prediction of the presence of irreversible ischemic change in patients with small bowel obstruction. However, the applicability of CT imaging in patients with incarcerated hernias has not been investigated in detail. The aim of this retrospective study was to evaluate the feasibility of preoperative CT findings for the prediction of the presence of irreversible ischemic change in patients with incarcerated hernias containing small bowel. METHODS: Included in this study were 76 patients who underwent surgery for preoperatively diagnosed incarcerated hernias containing small bowel (27 inguinal hernias, 37 femoral hernias and 12 obturator hernias) at our hospital between January 2011 and June 2020. The preoperative clinicoradiological features were compared between the groups, and predictors for intestinal resection were evaluated. RESULTS: Nineteen patients required intestinal resection (Resection group), and the other 57 patients did not require intestinal resection (Nonresection group). Multivariate analyses revealed that age ≥ 80 years (p = 0.018, odds ratio = 6.604) and the absence of bowel wall enhancement (p = 0.032, odds ratio = 51.200) were independent predictors for intestinal resection. In resected specimens, all patients with an absence of bowel wall enhancement on preoperative enhanced CT had ischemic changes extending beyond the muscularis propria. CONCLUSIONS: Preoperative enhancement CT yields useful information for the prediction of the presence of irreversible ischemic change in patients with incarcerated hernias containing small bowel.

Natural history of branch duct intraductal papillary-mucinous neoplasms of the pancreas without mural nodules: long-term follow-up results.

BACKGROUND AND AIMS: Although branch duct intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas without mural nodules are frequently observed in asymptomatic subjects, the natural history of these lesions has never been studied. The aim of this study was to elucidate the natural history of branch duct IPMNs without mural nodules. METHODS: Eighty-two patients who had no apparent mural nodules on initial examination were selected for follow-up. All subjects underwent examinations by imaging modalities including endoscopic retrograde pancreatography, and were followed-up by regular examinations once or twice a year. Serial changes of the maximum cystic diameter and the appearance of mural nodules were studied during the observation periods ranging from 14 to 148 months (median, 61 months). RESULTS: Nine (11.0%) of 82 patients exhibited obvious progression of cystic dilatation (median, 59 months). Of these nine patients with cystic enlargement, six continued with regular follow-up examinations. Three cases underwent surgical resection, and were pathologically diagnosed as adenoma in two and borderline in one. Four patients (4.9%) showed newly developed mural nodules in dilated branch ducts (median, 105 months). Histological analysis revealed three cases classified as adenoma and one as carcinoma in situ. None of the remaining 69 patients (84.1%) showed any changes in dilated branch ducts (median, 57 months). CONCLUSIONS: Most branch duct IPMNs without mural nodules remained unchanged during long-term follow-up. Although follow-up with careful examination is required to detect newly developed mural nodules in dilated branch ducts, branch duct IPMNs without mural nodules can be followed-up without surgery.

Laparoscopic repair is a treatment of choice for selected patients with incarcerated obturator hernia.

PURPOSE: The feasibility and potential advantages of laparoscopic diagnosis and repair of incarcerated obturator hernia (OH) is debated. The aim of this retrospective study was to compare short-term complications comparing laparoscopic to open repair of OH. METHODS: A total of 29 preoperatively diagnosed patients underwent surgery for a preoperatively diagnosed OH between January 2006 and July 2017. The patients were divided into a laparoscopic group (11 patients underwent laparoscopic repair; 8 without and 3 with intestinal resection) and an open group (18 patients who underwent open repair; 9 without and 9 with intestinal resection).The outcomes were compared between groups. A risk factor analysis for postoperative complications was performed. RESULTS: The incidence of postoperative complications was fewer in the laparoscopic group [9.0% vs. 61.1%; (p < 0.001)]. The bleeding amount [1.2 g vs. 40.4 g; (p = 0.087)] and postoperative length of stay [13.3 days vs. 17.1 days; (p = 0.072)] showed a tendency to be favorable in the laparoscopic group. Occult contralateral OH was detected in three patients (27.7%) in the laparoscopic group and one patient (5.5%) in the open group (p = 0.099). Open surgery and intestinal resection were independent risk factors for a postoperative complication. One patient in the open group developed an incarcerated OH on the contralateral side 1 year after the first surgery. CONCLUSIONS: Laparoscopic repair for incarcerated obturator hernia demonstrated more favorable short-term outcomes compared with open repair in terms of a lower incidence of postoperative complications and it was potentially beneficial for detecting and repairing an occult OH on the contralateral side.

Reduced thrombin binding and aggregation in Bernard-Soulier platelets.

Platelets from two patients with Bernard-Soulier disease showed a reduction in their ability to bind human thrombin. Thrombin binding studies in the high affinity range showed 1,500 sites for the Bernard-Soulier platelets as against 4,000 for normal controls. However, the dissociation constant was the same for both normals and patients (4.4 nM) indicating identical affinity for thrombin at the available sites. In the low affinity range, the Bernard-Soulier platelets showed 8,800 thrombin binding sites as against 24,000 for the controls, but again with identical values of Kd (37 nM). In addition, platelets from these Bernard-Soulier patients showed a decreased rate of aggregation with thrombin at both optimal (300 mU/ml) and suboptimal (60 and 120 mU/ml) thrombin concentrations. The decreased amount of thrombin which can bind to Bernard-Soulier platelets and the decrease in thrombin-induced aggregation may partly explain the hemostatic defect in these patients. In addition, the identical ratios of high affinity and low affinity binding sites in normals and in patients (0.37 and 0.36, and 0.36, respectively) supports the idea of a single class of binding sites for thrombin on the platelet surface.

The contemporary materials cycle for radioactive 137Cs in the United States.

The materials cycle for (137)Cs, a low-level radioactive material of interest from a security perspective (as a possible source for "dirty bombs") as well as for its extensive industrial and medical uses, has been characterized for the United States for the year 2000. The focus is on products utilizing the isotope rather than on isotope production and subsequent disposal as a result of nuclear power generation. The results indicate that, during 2000, of the 1.5 PBq of (137)Cs that entered use, 94% was contained in sources in imported devices; the amounts in domestic source material recycling (4%) or as imported source materials (2%) were trivial by comparison. Losses from use were about 0.5 PBq; of this amount 86% was by radioactive decay, 11% was active source material that was recovered and recycled, and 3% was source material sent to low-level disposal sites. The current stock of (137)Cs in use is about 20 PBq; this stock is currently growing by more than 1 PBq per year (the difference between inputs to and losses from use). As a result, the security challenge related to monitoring stock in use is increasing by around 5% per year.

The suppressive effect of apricot kernel extract on 5alpha-Androst-16-en-3-one generated by microbial metabolism.

Body odours are generated from dead skin cells and secreted materials, such as sweat and sebum, through the metabolism of microorganisms living on the skin. Volatile steroids, key compounds in body odours, are also generated through the metabolism of microorganisms. These volatile steroids strengthen the intensity of the overall body malodour and are sensed differently by males and females. Females are more sensitive than males to volatile steroids, especially 5alpha-androst-16-en-3-one (androstenone). To regulate body odours that are especially unpleasant for women, we devised an androstenone-generation model using the metabolism of Corynebacterium xerosis, which is one of the bacteria living on the axillary skin. Using this model, we studied the suppressive effect of plant extracts on the generation of androstenone. We found that apricot kernel extract (AKE) had the most positive effect among the plant extracts to which we applied the model. However, although AKE did suppress androstenone generation, it did not show any bactericidal effect. Using the cell-free system, AKE also suppressed the generation of androstenone. In conclusion, we found that AKE suppressed the generation of androstenone, which is especially unpleasant for women, and the mechanism was not bactericidal but metabolic inhibition. The results of these studies provide new understanding of the regulation of androstenone, which, in turn, should lead to the development of novel deodorant systems.

Activation of peroxisome proliferator-activated receptor gamma by troglitazone inhibits cell growth through the increase of p27KiP1 in human. Pancreatic carcinoma cells.

In the present study, we examine whether human pancreatic carcinoma cells express peroxisome proliferator-activated receptor gamma (PPARgamma) and the effect of PPARgamma activation by its selective ligand on cellular growth in pancreatic cancer cells. Immunohistochemical study of resected human pancreata using a polyclonal PPARgamma antibody revealed that PPARgamma protein expression in the nuclei of carcinoma cells was observed in 9 of 10 pancreatic adenocarcinomas. In contrast, normal pancreatic duct epithelial cells in the samples expressed no PPARgamma. Reverse transcription-PCR and Northern blot analysis demonstrated that all four tested human pancreatic cancer cell lines, PK-1, PK-8, PK-9, and MIA Paca-2, expressed PPARgamma mRNA. Luciferase assay in PK-1 cells showed that troglitazone, a selective ligand for PPARgamma, transactivated the transcription of a peroxisome proliferator response element-driven promoter in a dose-dependent fashion. Troglitazone inhibited the growth of all four pancreatic carcinoma cell lines in a dose-dependent manner. Cell cycle analysis by flow cytometry demonstrated that troglitazone induced G1 arrest in PK-1 cells. To examine the role of cyclin-dependent kinase inhibitors in the G1 arrest by troglitazone, we determined p27KiP1, p21CiP1/Waf1, or p18Ink4c protein expression by Western blot analysis in troglitazone-treated PK-1 cells. Troglitazone increased p27Kip1 but not p21Cip1/Waf1 or p18Inkc protein levels in time- and dose-dependent manners. To clarify the functional importance of p27Kip1 in the cell growth inhibition by troglitazone. All these results suggest that PPARgamma could be considered as a possible target molecule for treatment in human pancreatic carcinomas.

High density O-glycosylation of the MUC2 tandem repeat unit by N-acetylgalactosaminyltransferase-3 in colonic adenocarcinoma extracts.

A synthetic peptide corresponding to the human MUC2 tandem repeat unit was glycosylated in vitro using UDP-GalNAc and extracts of colonic adenocarcinoma and paired normal mucosa, followed by fractionation of the products by reverse phase high-performance liquid chromatography. Several peaks of glycopeptides with different numbers of GalNAc residues attached were detected. It is notable that the adenocarcinoma extract was capable of glycosylating peptides to a much greater extent than was normal mucosa. The levels of mRNA for N-acetylgalactosaminyltransferases-1, -2, and -3 were determined by reverse transcription-PCR. Only N-acetylgalactosaminyltransferase-3 mRNA was expressed at a higher level in the adenocarcinoma than in the normal tissue. When the MUC2 tandem repeat peptide was glycosylated with a mixture of the normal mucosa extract and recombinant N-acetylgalactosaminyltransferase-3, larger amounts of glycopeptides with higher contents of GalNAc residues were produced. The MUC2 tandem repeat peptides glycosylated extensively by recombinant N-acetylgalactosaminyltransferase-1, -2, or -3 were prepared and characterized. Substitution at each Thr residue, as revealed by Edman degradation sequencing, in conjunction with evidence obtained on mass spectrometry indicated a heterogeneous pattern of site-specific glycosylation within the MUC2 tandem repeat. It was found that maximum numbers of 6, 8, and 11 GalNAc residues were incorporated by N-acetylgalactosaminyltransferases-1, -2, and -3, respectively, and that only N-acetylgalactosaminyltransferase-3 could completely glycosylate both consecutive sequences composed of three and five Thr residues in the MUC2 tandem repeat unit. These results suggest that O-glycosylation of the clustered Thr residues is a selective process controlled by N-acetylgalactosaminyltransferase-3 in the synthesis of clustered carbohydrate antigens.

Water avoidance stress induces visceral hyposensitivity through peripheral corticotropin releasing factor receptor type 2 and central dopamine D2 receptor in rats.

BACKGROUND: Water avoidance stress (WAS) is reported to induce functional changes in visceral sensory function in rodents, but the results which have been demonstrated so far are not consistent, i.e., hypersensitivity or hyposensitivity. We determined the effect of WAS on visceral sensation and evaluated the mechanisms of the action. METHODS: Visceral sensation was assessed by abdominal muscle contractions induced by colonic balloon distention, i.e., visceromotor response (VMR), measured electrophysiologically in conscious rats. The electromyogram electrodes were acutely implanted under anesthesia on the day of the experiment. The threshold of VMR was measured before and after WAS for 1 h. To explore the mechanisms of WAS-induced response, drugs were administered 10 min prior to the initiation of WAS. KEY RESULTS: WAS significantly increased the threshold of VMR, and this effect was no longer detected at 24 h after. Intraperitoneal injection of astressin2 -B (200 µg/kg), a corticotropin releasing factor (CRF) receptor type 2 antagonist abolished the response by WAS. Subcutaneous (sc) injection of sulpiride (200 mg/kg), a dopamine D2 receptor antagonist blocked the response, while sc domperidone (10 mg/kg), a peripheral dopamine D2 receptor antagonist did not alter it. Naloxone (1 mg/kg, sc), an opioid antagonist did not modify it either. CONCLUSIONS & INFERENCES: WAS induced visceral hyposensitivity through peripheral CRF receptor type 2 and central dopamine D2 receptor, but not through opioid pathways. As altered pain inhibitory system was reported to be observed in the patients with irritable bowel syndrome, CRF and dopamine signaling might contribute to the pathophysiology.

A sex difference in the effect of prostaglandins on hormone-stimulated glycogenolysis in primary cultures of rat hepatocytes.

E series prostaglandins and their biologically active analogue, 16,16-dimethylprostaglandin E2 (dimethylprostaglandin E2), have inhibited hormone-stimulated glycogenolysis in hepatocytes cultured from male rats (Okumura, T., Sago, T. and Saito, K. (1988) Biochim. Biophys. Acta 958, 179-187). However, in the case of female rat hepatocytes, it is evident that dimethylprostaglandin E2 did not inhibit the glycogenolysis stimulated by glucagon, isoproterenol (beta-adrenergic response) or epinephrine (with propranolol, alpha 1-adrenergic response) in cultures on day 1. Dimethylprostaglandin E2 inhibited such hormone-stimulated glycogenolysis in cultures on day 2 and 3, but to a lesser extent than in the male-derived cells. The concentration for 50% inhibition was approx. 10(-8) M; inhibition was completely blocked by a pertussis toxin. Prostaglandin E2 had the same effect as dimethylprostaglandin E2; prostaglandins D2 and F2 alpha had no effect. Additions of sex hormones, 17 beta-estradiol and testosterone, and palmitic acid (diminishing the prostaglandin catabolism) to the culture medium did not change the effect of dimethylprostaglandin E2. These data indicate that a sex difference exists in the inhibition of hepatic glycogenolysis by prostaglandin E2 and its analogue in rat cultured hepatocytes, although the factor causing such a difference is a present unknown.