Biomedical subjects

M T Liu

Publications and source records attributed to M T Liu.

At least 37 records · Page 2Linked to original sources

PubMed1999

Differential localization of Ca2+ channel alpha1 subunits in the enteric nervous system: presence of alpha1B channel-like immunoreactivity in intrinsic primary afferent neurons.

Immunocytochemistry was employed to locate calcium (Ca2+) channel proteins in the enteric nervous system (ENS) of the rat and guinea pig. Anti-peptide antibodies that specifically recognize the alpha1 subunits of class A (P/Q-type), B (N-type), C and D (L-type) Ca2+ channels were utilized. Alpha1B channel-like immunoreactivity was abundant in both enteric plexuses, the mucosa, and circular and longitudinal muscle layers. Immunoreactivity was predominantly found in cholinergic varicosities, supporting a role for Ca2+ channels, which contain the alpha1B subunit, in acetylcholine release. Immunoreactivity was also associated with the cell soma of calbindin-immunoreactive submucosal and myenteric neurons, cells that have been proposed to be intrinsic primary afferent neurons. Alpha1C channel-like immunoreactivity was distributed diffusely in the cell membrane of a large subset of neuronal cell bodies and processes, whereas alpha1D was found mainly in the cell soma and proximal dendrites ofvasoactive intestinal polypeptide-immunoreactive neurons in the guinea pig gut. Alpha1A channel-like immunoreactivity was found in a small subset of cell bodies and processes in the rat ENS. The differential localization of the alpha1 subunits of Ca2+ channels in the ENS implies that they serve distinct roles in neuronal excitation and signaling within the bowel. The presence of alpha1B channel-like immunoreactivity in putative intrinsic primary afferent neurons suggested that class B Ca2+ channels play a role in enteric sensory neurotransmission; therefore, we determined the effects of the N-type Ca2+ channel blocker, omega-conotoxin GVIA (omega-CTx GVIA), on the reflex-evoked activity of enteric neurons. Demonstrating the phosphorylation of cyclic AMP (cAMP)-responsive element-binding protein (pCREB) identified neurons that became active in response to distension. Distension elicited hexamethonium-resistant pCREB immunoreactivity in calbindin-immunoreactive neurons in each plexus; however, in preparations stimulated in the presence of omega-CTx GVIA, pCREB immunoreactivity was found only in calbindin-immunoreactive neurons in the submucosal plexus and not in myenteric ganglia. These data confirm that intrinsic primary afferent neurons are located in the submucosal plexus and that N-type Ca2+ channels play a role in sensory neurotransmission.

Animals↗

PubMed1999

Acute febrile neutrophilic dermatosis (Sweet's syndrome) in hairy cell leukemia: a case report.

Sweet's syndrome is a cutaneous reactive process that is usually associated with fever, but rarely occurs in patients with hairy cell leukemia (HCL). We report the case of a patient with HCL who developed typical Sweet's syndrome five months after the diagnosis of HCL. Skin eruptions and constitutional symptoms subsided rapidly after short-term systemic adrenocorticosteroid treatment without recurrence, until the patient died from disease exacerbation and uncontrolled infection. According to his manifestations, chemical allergens, microorganisms or HCL progression were unlikely to have been the precipitating factors for development of Sweet's syndrome. Because immunologic disorders and opportunistic infection are not uncommon in patients with HCL, a skin biopsy should be taken as early as possible when cutaneous lesions and fever develop in order to establish a correct diagnosis. Hence, unnecessary and prolonged use of antibiotics is avoided and prompt relief of the symptoms by appropriate management can be achieved.

Diagnosis, Differential↗

PubMed1998

Epstein-Barr virus DNase contains two nuclear localization signals, which are different in sensitivity to the hydrophobic regions.

The DNase of Epstein-Barr virus (EBV) is a 470-amino-acid protein which possesses both endonuclease and exonuclease activities and accepts both double-stranded DNA and single-stranded DNA as substrates. It has been reported that this protein may be found in the nucleus and/or cytoplasm of infected cells. In this study, using cell fractionation and immunoblotting to determine the distribution of EBV DNase in Akata cells stimulated with anti-human immunoglobulin G antibody (anti-IgG), the DNase was found to be located predominantly in the nucleus. To map the signals in DNase which mediate its nuclear localization, we monitored the nuclear transport of fusion proteins consisting of various fragments of EBV DNase linked to a cytoplasmic protein, beta-galactosidase (beta-Gal). The results demonstrated that two regions of the DNase with nuclear localization signal (NLS) activity, designated NLS-A (amino acids 239-266) and NLS-B (amino acids 291-306), were able independently to localize the beta-Gal to the nuclei of HEp-2 and HeLa cells. Five basic residues (R or K) were found in each NLS and distributed differently in primary structure. The basic domains and flanking residues of NLS-A and NLS-B are 250YKRPCKRSFIRFI262 and 294LKDVRKRKLGPGH306, respectively. Further examination of these sequences revealed that NLS-A contains bulky aromatic amino acids (Y and F) which may diminish its capacity to act as a strong NLS and lacks the typical proline and glycine helix-breakers. However, NLS-B contains typical proline and glycine helix-breakers and the histidine residue at amino acid 306 is required for NLS activity. In addition, two hydrophobic regions within the DNase were found to inhibit the function of NLS-A but not NLS-B, suggesting that these two domains are different types of NLSs and differ in their sensitivity to hydrophobic regions in the context of protein structure.

Base Sequence↗

PubMed1998

Distinct regions of EBV DNase are required for nuclease and DNA binding activities.

Epstein-Barr virus (EBV) DNase possesses both endonuclease and exonuclease activities and accepts both double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) as substrates. To map regions of EBV DNase responsible for nuclease and DNA binding activities, a series of mutant DNase polypeptides was expressed using a bacterial system for the nuclease assay and in an in vitro transcription/translation system to assay binding activity to dsDNA or ssDNA cellulose. The results indicated that the C-terminus of EBV DNase, residues 450-460, is essential for nuclease activity but dispensable for DNA binding. However, deletion of residues 441-470 resulted in the loss of both nuclease and DNA binding activities. Substitution of Phe452 and Val458 led to inactive enzymes. In the N-terminus, deletion of residues 23-28 and residues 7-61 resulted in the loss of nuclease activity but the DNA binding activities of the deleted enzymes were intermediate and low, respectively. Mutation of Leu23 to Gly showed drastically reduced nuclease activity but its DNA binding ability was not affected. Based on the amino acid sequence alignment of various herpesvirus DNases, we chose four highly conserved and two less well conserved regions as controls for mutagenesis studies. These six internal deletion (ID) mutants were prepared using a recombinant PCR method. Each of the polypeptides was expressed in a bacterial system for the nuclease assay and using an in vitro transcription/translation system for the DNA binding assay. DNA binding and nuclease activities of all six internal deletion mutants were abolished, except that mutant ID2, with deletion of residues 138-152, retained an intermediate ability to bind DNA. These data indicate that since mutations at distinct regions within EBV DNase resulted in the loss of nuclease and/or DNA binding activities, it is suggested that these distinct regions are required for maintenance of an intact and highly ordered structure(s) for both activities.

Amino Acid Sequence↗

PubMed1998

Immunohistochemical localization of nicotinic acetylcholine receptors in the guinea pig bowel and pancreas.

Although nicotinic acetylcholine receptors (nAChRs) are known to be present on neural elements in both the bowel and the pancreas, the precise location of these receptors has not previously been determined. Immunocytochemistry, by using a rat monoclonal antibody (mAb35), which recognizes alpha-bungarotoxin (alpha-Bgt)-insensitive nAChRs, and a polyclonal antibody raised against the alpha-Bgt-sensitive receptor subunit, alpha7, was used to locate receptor protein in guinea pig gut and pancreas. mAb35-receptor (mAb35-R) immunoreactivity was abundant in both enteric plexuses, enterochromaffin cells, and pancreatic ganglia. Immunostaining was associated with the cell membrane, and clusters of mAb35-R were observed on cell somas and dendrites. Receptor immunoreactivity was also observed on terminals and axons, suggesting that a subset of nAChRs is presynaptic. Internal sites of mAb35-R were observed in permeabilized ganglia. Cells expressing the receptors were closely associated with ChAT-immunoreactive nerve fibers. In addition, the majority of ChAT-positive neurons expressed both cell surface and internal stores of mAb35-R. In the bowel, clusters of mAb35-R were present on the soma and dendrites of Dogiel type I motorneurons and secretomotor neurons. Receptors were detected at the plasma membrane of calbindin-immunoreactive myenteric neurons. In contrast, calbindin-immunoreactive submucosal neurons did not express cell surface mAb35-R, supporting the idea that they are sensory neurons. A subset of enteric neurons expressed both mAb35-R and glutamate receptor (GluR1) immunoreactivity. In the pancreas, mAb35-R immunoreactivity was only observed in ganglia. Alpha7-immunoreactivity was found on both enteric cell bodies and nerve fibers. Based on these results, it appears that visceral nAChRs are composed of at least four subunits and that both pre- and postsynaptic nAChRs are present in the gut and pancreas.

Animals↗

PubMed1998

Anti-GT1b and anti-GM1 antibodies can increase after stroke but neither is associated with late post-apoplectic epilepsy.

The role of antiganglioside antibodies (AGAs) in late post-apoplectic epilepsy (LPAE) was studied. Serum AGAs from 8 patients with large lobar infarctions were serially checked for 2.5 months. Sera from another 30 patients with fronto-temporoparietal (FTP) or frontal (F) infarction were obtained 3 months to 3 years after a stroke for AGA analysis. These 30 patients were followed up for 3 years following their strokes to determine if LPAE developed. Results showed that 7/8 patients with large lobar infarction showed increase in either anti-GT1b or anti-GM1 (IgM or IgG) within a few weeks, but levels returned to the baseline 2-3 months after stroke. LPAE occurred in 9/21 patients with FTP infarction and 5/9 with F infarction. There was no difference in AGAs among patients with FTP and F infarctions. Pooled data from these 2 groups showed no correlation between AGAs and LPAE. These data document for the first time that anti-GT1b and anti-GM1 antibodies can transiently increase after stroke, but their late titers are not associated with LPAE.

Adult↗

PubMed1997

Excitotoxicity in the enteric nervous system.

Glutamate, the major excitatory neurotransmitter in the CNS, is also an excitatory neurotransmitter in the enteric nervous system (ENS). We tested the hypothesis that excessive exposure to glutamate, or related agonists, produces neurotoxicity in enteric neurons. Prolonged stimulation of enteric ganglia by glutamate caused necrosis and apoptosis in enteric neurons. Acute and delayed cell deaths were observed. Glutamate neurotoxicity was mimicked by NMDA and blocked by the NMDA antagonist D-2-amino-5-phosphonopentanoate. Excitotoxicity was more pronounced in cultured enteric ganglia than in intact preparations of bowel, presumably because of a reduction in glutamate uptake. Glutamate-immunoreactive neurons were found in cultured myenteric ganglia, and a subset of enteric neurons expressed NMDA (NR1, NR2A/B), AMPA (GluR1, GluR2/3), and kainate (GluR5/6/7) receptor subunits. Glutamate receptors were clustered on enteric neurites. Stimulation of cultured enteric neurons by kainic acid led to the swelling of somas and the growth of varicosities ("blebs") on neurites. Blebs formed close to neurite intersections and were enriched in mitochondria, as revealed by rhodamine 123 staining. Kainic acid also produced a loss of mitochondrial membrane potential in cultured enteric neurons at sites where blebs tended to form. These observations demonstrate, for the first time, excitotoxicity in the ENS and suggest that overactivation of enteric glutamate receptors may contribute to the intestinal damage produced by anoxia, ischemia, and excitotoxins present in food.

Animals↗

PubMed1997

Glutamatergic enteric neurons.

We tested the hypothesis that glutamate, the major excitatory neurotransmitter of the CNS, is also an excitatory neurotransmitter in the enteric nervous system (ENS). Glutamate immunoreactivity was found in cholinergic enteric neurons, many of which were identified as sensory by their co-storage of substance P and/or calbindin. Glutamate immunoreactivity was concentrated in terminal varicosities with a majority of small clear synaptic vesicles. The immunoreactivities of both AMPA and NMDA receptor subunits were also detected on neurons in both submucosal and myenteric plexuses. The immunoreactivity of the EAAC1 neuronal glutamate transporter was widespread in both plexuses. Glutamate evoked depolarizing responses in myenteric neurons that had fast and slow components. The fast component was mimicked by AMPA, and the slow component was mimicked by NMDA. The fast component and the response to AMPA mimicked fast EPSPs evoked in 2/AH neurons; moreover, fast EPSPs as well as fast glutamate and AMPA responses were blocked by selective AMPA antagonists and potentiated by the glutamate uptake inhibitor L-(-)-threo-3-hydroxyaspartic acid. These observations demonstrate, for the first time, the presence of glutamatergic neurons and glutamate-mediated neurotransmission in the ENS.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1997

Guinea pig pancreatic neurons: morphology, neurochemistry, electrical properties, and response to 5-HT.

The morphology, neurochemistry, and electrical properties of guinea pig pancreatic neurons were determined. The majority of neurons expressed choline acetyltransferase (ChAT) immunoreactivity; however, ChAT-negative neurons were also found. Both cholinergic and noncholinergic neurons expressed nitric oxide synthase (NOS) immunoreactivity. Three types of pancreatic neurons were distinguished. Phasic neurons fired action potentials (APs) at the onset of depolarizing current pulse, tonic neurons spiked throughout the duration of a suprathreshold depolarizing pulse, and APs could not be generated in nonspiking neurons, even though they did receive synaptic input. APs were tetrodotoxin sensitive, and all types of neurons received fast and slow excitatory postsynaptic potentials (EPSPs). Fast EPSPs had cholinergic and noncholinergic components. The majority of pancreatic neurons appeared to innervate the acini. NOS- and/or neuropeptide Y-immunoreactive phasic and tonic neurons were found. Microejection of 5-hydroxytryptamine (5-HT) caused a slow depolarization that was inhibited by the 5-HT1P antagonist N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide and mimicked by the 5-HT1P agonist 6-hydroxyindalpine. A pancreatic 5-HT transporter was located, and inhibition of 5-HT uptake by fluoxetine blocked slow EPSPs in 5-HT-responsive neurons by receptor desensitization.

Action Potentials↗

PubMed1997

[Detection of poliovirus by digoxigenin-labeled cDNA probe prepared by PCR technique].

A study including reverse transcribed cDNAs of Sabin I, II, III virus used as templates and digoxigenin-labeled dUTP added to the reaction solution was carried out. After amplification, digoxigenin-labeled poliovirus cDNA probe was prepared by this PCR technique. Results showed that the direct preparation of digoxigenin-labeled poliovirus cDNA probe by PCR is a convenient and rapid method with a high labeling rate. Compared with neutralization test, the probe has the advantages of more rapid, more sensitive and more specific for poliovirus typing.

DNA, Complementary↗

PubMed1996

In situ identification and visualization of neurons that mediate enteric and enteropancreatic reflexes.

To identify neurons participating in enteric and enteropancreatic reflexes, we validated the use of the activity-dependent markers FM1-43 and FM2-10 as "on-line" probes for the visualization of activated guinea pig enteric and pancreatic neurons. FM1-43 or FM2-10 labeling of neuronal perikarya and processes was induced by KCl (70 mM), veratridine (1.0 microM), intracellular injection of depolarizing current pulses, stimulation of afferent inputs, evoking reflexes (by inflating an intraluminal balloon, blowing puffs of N2 at, or applying glucose to, the villous surface of the duodenum), or injury; labeling was prevented by tetrodotoxin (0.5 microM). Intracellular recording and injection of Neurobiotin confirmed that FM1-43 labeled neurons that spike, but not those that exhibit only fast excitatory postsynaptic potentials. Perikarya did not label if axonal transport was blocked by colchicine. When pulses of N2 or glucose were directed at duodenal villi in vitro, labeling by FM1-43 or FM2-10 was observed in myenteric and pancreatic neurons, as well as in subsets of cells in pancreatic islets and intestinal crypts. Hexamethonium blocked the spread of label via nicotinic synapses and thus enabled primary afferent neurons to be located. Balloon distension elicited hexamethonium-resistant labeling of epithelial cells, interstitial cells, and Dogiel type II neurons in each plexus; however, in preparations stimulated with pulses of N2 or glucose, hexamethonium-resistant labeling of neurons occurred only in the submucosal plexus and not in myenteric ganglia. These observations suggest that primary afferent neurons responsible for mucosal pressure- or glucose-induced enteric and enteropancreatic reflexes are submucosal, whereas myenteric afferent neurons become activated only when the wall of the bowel is distended. The data are compatible with the possibility that primary afferent neurons are activated by a signaling molecule released from intestinal epithelial cells.

Animals↗

PubMed1996

Identification of cells that express 5-hydroxytryptamine1A receptors in the nervous systems of the bowel and pancreas.

Although serotonin (5-HT)1A receptors are known to be present on neural elements in both the bowel and the pancreas, the precise location of these receptors has not previously been determined. Earlier investigations have suggested that 5-HT1A receptors are synthesized in enteric, but not pancreatic ganglia, and that they mediate pre-and postjunctional inhibition. Wholemount in situ hybridization was used to identify cells that contain mRNA encoding 5-HT1A receptors, and immunocytochemistry was employed to locate receptor protein. mRNA encoding 5-HT1A receptors was found in the majority of neurons in both submucosal and myenteric plexuses. 5-HT1A immunoreactivity, however, was abundant only on the surfaces of a limited subset of nerve cell bodies and processes. 5-HT-immunoreactive axons were found in close proximity to sites of 5-HT1A immunoreactivity. Myenteric, but not submucosal calbindin-immunoreactive neurons (with Dogiel type II morphology) were surrounded by rings of 5-HT1A immunoreactivity. The cytoplasm of the cell bodies and dendrites of a small subset of Dogiel type I neurons was also intensely 5-HT1A immunoreactive. Most of the Dogiel type I 5-HT1A-immunoreactive myenteric neurons, and some of the type II neurons that were ringed by 5-HT1A immunoreactivity became doubly labeled following injections of the retrograde tracer, FluoroGold (FG), into the submucosal plexus. 5-HT1A-immunoreactive neurons in distant submucosal ganglia also became labeled by retrograde transport of FG. None of the 5-HT1A-immunoreactive cells were labeled by the intraluminal administration of the beta-subunit of cholera toxin, a marker for vasoactive intestinal peptide-containing secretomotor neurons. These observations suggest that some of the myenteric 5-HT1A-immunoreactive neurons project to submucosal ganglia and that the submucosal 5-HT1A-immunoreactive cells are interneurons. In addition to neurons, a subset of 5-HT-containing enterochromaffin cells expressed 5-HT1A immunoreactivity, which was co-localized with 5-HT in secretory granules. In the pancreas, 5-HT1A immunoreactivity was observed in ganglia, acinar nerves, and glucagonimmunoreactive islet cells. Serotonergic enteropancreatic axons have been found to terminate in close proximity to each of these structures, which may thus be the targets of this innervation. The abundance of 5-HT1A receptor immunoreactivity on nerves of the gut and pancreas suggests that drugs designed to interact with these receptors may have unanticipated visceral actions.

Animals↗

PubMed1996

American cockroach Cr-PI allergen induces lymphocyte proliferation and cytokine production in atopic patients.

BACKGROUND: Previous studies have shown cockroach-induced antigen-specific IgE-mediated asthma. In cockroach-infested areas, more then 50% of asthmatic subjects may have positive skin reactions to this allergen. Partial purified Cr-PI allergen from American cockroaches contains allergens with molecular weights of 72 and 78 kDa; however, little is known about its effect on the lymphocyte proliferation and cytokine production. OBJECTIVE: IgE synthesis is known to be regulated by interleukin-4 (IL-4) and interferon gamma (IFN gamma). Therefore, we studied Cr-PI allergen-induced cytokine production in atopic patients and healthy normal controls to understand each factors' role in the disease. METHODS: Peripheral blood mononuclear cells (PBMC) from cockroach skin-sensitive patients and controls were stimulated with mitogen and Cr-PI for proliferative response and cytokine production. Cr-PI antigen-specific T-cell cultures of atopic patients and healthy normal controls were used to test Cr-PI-induced proliferation and cytokine mRNA expression. RESULTS: PMBC of atopic subjects showed a significantly (P < 0.01) higher stimulation index for Cr-PI induced proliferation (SI = 11.8 +/- 3.7) when compared with that of non-atopic subjects (SI = 4.1 +/- 0.8) and cord bloods (SI = 2.1 +/- 0.4). Cr-PI-induced IL-4 was observed only in the PBMC of atopic patients, whereas Cr-PI-induced IFN gamma was detected in both atopic patients and normal controls. Likewise, Cr-PI-induced IL-4 mRNA expression in T-cell cultures was detected in all atopics but only one of nine controls. CONCLUSION: IL-4 mRNA expression and IL-4 production in PBMC and T-cell cultures of atopic patients showed good correlation with clinical symptoms, skin-reactivity, specific IgE and proliferative response to Cr-PI. These results suggests that cockroach allergen may be a hidden cause of asthma and other atopic diseases.

Adult↗

PubMed1996

Use of recombinant Epstein-Barr virus early antigen for detection of antibody in patients with nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is one of the most common cancers in southern China and Taiwan. Serological studies revealed the close-relationship between NPC and Epstein-Barr virus (EBV). Elevated serum and saliva levels of anti-EBV antibodies are detected in patients with NPC. Therefore, Development Center for Biotechnology prepared the EBV-early antigen (EA-D) by recombinant DNA technique for screening the serum and throat washing samples from patients with head and neck cancers. METHODS: The BMRF1 gene for EBV early antigen (EA-D) was placed into the plasmid pDB18, then transformed into an Escherichia coli strain containing the lambda cI857 temperature-sensitive repressor. Heat treatment of the transformant, at exponential growth phase, inactivated the cI protein and induced an over-expression of the EA-D protein. Next, the EA-D was purified by chromatography and characterized as a protein of molecular weight 47 kDa, by sodium dodecyl sulfate-polyacry lamide gel electrophoresis (SDS-PAGE) and Western blot analysis using monoclonal anti-EA antibody and sera from patients with nasopharyngeal carcinoma (NPC). Enzyme-linked immunosorbent assay (ELISA) with the purified EA-D antigen was used to screen 129 serum and throat washing (TW) samples from patients with head and neck tumors, 24 from patients with a nonmalignant disease and 44 from normal donors. RESULTS: Experimental results indicated significantly higher positive rates of EA-D IgA (69%) and EA-D IgG (91%) in NPC sera than in the sera of patients with other head and neck tumors and normal controls. TW samples from patients with NPC also showed a higher positive rate (34%) than the other groups (7-20%). CONCLUSIONS: Results in this study demonstrate that the bacterially expressed EA-D antigen could be recognized by sera from patients with NPC and monoclonal anti-EA antibody. Thus, it has potential use in ELISA for screening EBV-related diseases such as NPC.

Antibodies, Viral↗

PubMed1996

[Detection of poliovirus in fecal specimens by polymerase chain reaction].

Poliovirus-RNA was detected in 11 clinical fecal specimens with AFP out of 19 samples. These comparative results between NT and Mcab identifications showed a coincidence rate of 90.90%-100%. Our experiment suggested that PCR a simple, sensitive, identification type and could be used for intratypic-differentiation of poliovirus strains. It can also be applied for the detection of poliovirus contamination in the environment.

Feces↗

PubMed1995

Anatomic site distribution of colon cancer by race and other colon cancer risk factors.

PURPOSE: Black patients with colon cancer are more likely to have poorer survival from colon cancer than are white patients. To determine whether anatomic site differences might contribute to survival differences, we compared anatomic site distributions of black and white patients. METHODS: As part of the Black/White Cancer Survival Study, we collected medical record data for 1,045 patients from Atlanta, New Orleans, and San Francisco/Oakland, newly diagnosed in 1985 or 1986 and interviewed 745 of them. RESULTS: In polychotomous logistic regression analysis, site was related to stage, grade, and histologic type and among women with age, parity, and possibly smoking. However, it was not related to race, except perhaps among men age 65 and older, among whom blacks were somewhat likely to have more transverse and distal, not proximal, cancer. These relations were consistent across subgroups and were independent of other factors examined. CONCLUSION: Results suggest that site differences are unlikely to contribute to poorer survival commonly observed among black colon cancer patients in the United States.

Adult↗

PubMed1995

Collagen induces cytokine production by synovial fluid mononuclear cells in rheumatoid arthritis.

Synovial fluid (SF) mononuclear cells (MNC) from 13 patients with rheumatoid arthritis (RA) and 12 patients with other arthritic diseases (OD) including osteoarthritis (OA), gout and spondyloarthritis (SA) were cultured in the presence of collagen types I and II or lipopolysaccharide (LPS) for 24 h. Interleukin-1 (IL-1), IL-6 and tumor necrosis factor-alpha (TNF-alpha) in the SF and culture supernatants were assayed using ELISA. The results showed that one-half of the RA patients with high SF monocyte count had high SF IL-6 levels that coincided with the high spontaneous release of IL-6 by SF MNC. In the other RA patients with lower SF monocyte count, type II collagen induced significantly higher IL-1 beta than the medium control levels by SF MNC (P < 0.01) or that of the other diseases (P < 0.01). Similarly, type II collagen-induced IL-6 and TNF-alpha production rose significantly (P < 0.01) from SF MNC of RA but less from OD (P < 0.05). In addition, type I collagen could also induce IL-1, IL-6 and TNF-alpha in these samples from RA and OD patients but was less potent than type II collagen. Our results indicate that collagen-induced cytokines may be important in the pathogenesis of the disease.

Arthritis, Rheumatoid↗

PubMed1994

NADPH diaphorase (nitric oxide synthase)-containing nerves in the enteropancreatic innervation: sources, co-stored neuropeptides, and pancreatic function.

Pancreatic ganglia are innervated by neurons in the gut and are formed by precursor cells that migrate into the pancreas from the bowel. The innervation of the pancreas, therefore, may be considered an extension of the enteric nervous system. NADPH-diaphorase is present in a subset of enteric neurons. We investigated the presence of NADPH-diaphorase in the enteropancreatic innervation, the contribution of extrinsic nerves to the NADPH-diaphorase-containing fibers of the gut and pancreas, and the coincident expression of NADPH-diaphorase NADPH-diaphorase in intrinsic neurons of these organs with neuropeptides. The possible role of nitric oxide in the neural regulation of pancreatic secretion was studied in isolated pancreatic lobules. Neuronal perikarya with NADPH-diaphorase activity were found in both Dogiel type I and type II neurons of the myenteric plexus of the stomach and duodenum. All galanin (GAL)-immunoreactive neurons and a small subset of vasoactive intestinal polypeptide (VIP)- and neuropeptide Y (NPY)-immunoreactive neurons contained NADPH-diaphorase activity. NADPH-diaphorase activity was also found in a subset of VIP and NPY-immunoreactive pancreatic neurons. Retrograde tracing with FluoroGold established that NADPH-diaphorase-containing neurons in the bowel project to the pancreas. NADPH-diaphorase-containing fibers were also found to be provided to both organs by neurons in dorsal root ganglia. Secretion of amylase was evoked by L-arginine. This effect was prevented by N(G)-nitro-L-arginine (L-NNA), which also inhibited VIP-stimulated secretion of amylase; however, L-NNA had no effect on amylase secretion stimulated by carbachol. These results provide support for the hypothesis that nitric oxide plays a role in the neural regulation of pancreatic secretion.

Amylases↗